Blends of ethylenic polymers with improved modulus and melt strength and articles fabricated from these blends
Abstract
A foam made of a mixture comprising: A) a heterogeneous or homogeneous linear ethylene homopolymer or interpolymer, wherein the homopolymer or interpolymer has a density greater than, or equal to, 0.944 g / cm 3, and a melt index , I2, less than 10 g / 10 min, and B) a branched ethylene homopolymer or interpolymer selected from the group consisting of LDPE, EVA and EAA, and wherein the homopolymer or interpolymer has a melt index, I2, of 0 , 05 to 10 g / 10 min; and wherein said mixture has: 1) a melt index, I2, from 0.05 to 20 g / 10 min; 2) a flexural modulus of = 700 MPa (100,000 psi); 3) a melt strength of> = 10 cN at 190 ° C; 4) a melt extensibility of> = 25 mm / s; 5) a higher service temperature (TSS) greater than 115 ° C; and 6) wherein said melt strength of said mixture meets the following inequality; Melt strength> FMS * [(f * A) + ((1-f) * B)] where A = 3, 3814 * (1 / I2) 0, 6476 and B = 10 (1, 2896-0, 4278 * log10 (I2)); I2 is the measured melt index of the mixture; and FMS is> = 1, 1, and where the foam is substantially uncrosslinked.

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6 claims: 6 independent, 0 dependent
- 1ES 2 295 337 T3 ES 2 295 337 T3 CLAIMS REIVINDICACIONES 1. A foam made from a mixture comprising:1. Una espuma hecha de una mezcla que comprende: A) a heterogeneous or homogeneous linear ethylene homopolymer or interpolymer, wherein the homopolymer or interpolymer has a density greater than or equal to 0.944 g / cm3, and a melt index, I2, less than 10 g / 10 min, and A) un homopolímero o interpolímero de etileno lineal heterogéneo u homogéneo, en donde el homopolímero o interpolímero tiene una densidad mayor que, o igual a, 0,944 g/cm3, y un índice de fusión, I2, menor que 10 g/10 min, y B) a branched ethylene homopolymer or interpolymer selected from the group consisting of LDPE, EVA, and eAa, and wherein the homopolymer or interpolymer has a melt index, I2, of 0.05 to 10 g / 10 min;and where said mixture has: B) un homopolímero o interpolímero de etileno ramificado seleccionado del grupo que consiste en LDPE, EVA y eAa, y en donde el homopolímero o interpolímero tiene un índice de fusión, I2, de 0,05 a 10 g/10 min;y en donde dicha mezcla tiene: 1) a melt index, I2, of 0.05 to 20 g / 10 min;1) un índice de fusión, I2, de 0,05 a 20 g/10 min;
- 22) a flexural modulus of> 700 MPa (100,000 psi);2) un módulo a la flexión de > 700 MPa (100.000 psi);
- 33) a melt strength of> 10 cN at 190 ° C;3) una resistencia del fundido de > 10 cN a 190°C;
- 44) a melt extensibility of> 25 mm / s;4) una extensibilidad del fundido de > 25 mm/s;
- 55) an upper service temperature (TSS) greater than 115 ° C;Y 5) una temperatura superior de servicio (TSS) mayor que 115°C;y
- 66) en donde dicha resistencia del fundido de dicha mezcla cumple la siguiente desigualdad; 6) wherein said melt strength of said mixture meets the following inequality; Melt strength> FMS* [(f * A) + ((1-f) * B)] where A = 3.3814 * (1 / I2)0·6476 and B = 10 (1·2896-°·4278*1°81°(12»; I2 is the measured melt index of the mixture; and FMS is> 1.1, and wherein the foam is substantially uncrosslinked. Resistencia del fundido > FMS* [(f*A) + ((1-f)*B)] donde A = 3,3814*(1/I2)0·6476 y B = 10(1·2896-°·4278*1°81°(12»; I2 es el índice de fusión medido de la mezcla; y FMS es > 1,1, y en donde la espuma es sustancialmente no reticulada. 2. The foam of claim 1, wherein 2. La espuma de la reivindicación 1, en la que A) Component A is a heterogeneous or homogeneous linear ethylene homopolymer, or an interpolymer of ethylene with at least one α-olefin C3-C20; and where said mixture has:A) el componente A es un homopolímero de etileno lineal heterogéneo u homogéneo, o un interpolímero de etileno con al menos una α-olefina C3-C20;y en donde dicha mezcla tiene: 1) a melt index, I2, of 0.1 to 10 g / 10 min;1) un índice de fusión, I2, de 0,1 a 10 g/10 min;2) a flexural modulus of> 840 MPa (120,000 psi);2) un módulo a la flexión de > 840 MPa (120.000 psi);3) a melt extensibility of> 50 mm / s;3) una extensibilidad del fundido de > 50 mm/s;4) an upper service temperature (TSS) greater than 118 ° C;Y 4) una temperatura superior de servicio (TSS) mayor que 118°C;y 5) Fms es > 1,25. 5) Fms is> 1.25. 3. The foam of claim 1, wherein 3. La espuma de la reivindicación 1, en la que A) Component A is a linear or substantially linear ethylene homopolymer, or an ethylene / α-olefin interpolymer C3-C8 linear or substantially linear, and A) el Componente A es un homopolímero de etileno lineal o sustancialmente lineal, o un interpolímero de etileno/ α-olefina C3-C8 lineal o sustancialmente lineal, y B) Component B is LDPE;and wherein said mixture has;B) el Componente B es LDPE;y en donde dicha mezcla tiene;1) a melt index, I2, of 0.2 to 7 g / 10 min;1) un índice de fusión, I2, de 0,2 a 7 g/10 min;2) a flexural modulus of> 910 MPa (130,000 psi);2) un módulo a la flexión de > 910 MPa (130.000 psi);3) a melt extensibility of> 75 mm / s;3) una extensibilidad del fundido de > 75 mm/s;4) an upper service temperature (TSS) greater than 121 ° C;Y 4) una temperatura superior de servicio (TSS) mayor que 121°C;y 5) FMS es > 1,5. 5) FMS is> 1.5. ES 2 295 337 T3 ES 2 295 337 T3 4. La espuma de la reivindicación 3, en la que dicha mezcla tiene: Four. The foam of claim 3, wherein said blend has: 1) a melt index, I2, less than 15 g / 10 min, 1) un índice de fusión, I2, menor que 15 g/10 min, 2) an upper service temperature (TSS) greater than 125 ° C;Y 2) una temperatura superior de servicio (TSS) mayor que 125°C;y 3) FMS es > 2,5. 3) FMS is> 2.5. 5. A mixture comprising: 5. Una mezcla que comprende: A) a heterogeneous or homogeneous linear ethylene homopolymer or interpolymer, and wherein the homopolymer or interpolymer has a flexural modulus of less than 196 MPa (28,000 psi);A) un homopolímero o interpolímero de etileno lineal heterogéneo u homogéneo, y en donde el homopolímero o interpolímero tiene un módulo a la flexión menor que 196 MPa (28.000 psi);B) a branched ethylene homopolymer or interpolymer, selected from the group consisting of LDPE, EVA and EAA, and wherein the homopolymer or interpolymer has a melt index, I2, of 0.05 to 10 g / 10 min;B) un homopolímero o interpolímero de etileno ramificado, seleccionado del grupo que consiste en LDPE, EVA y EAA, y en donde el homopolímero o interpolímero tiene un índice de fusión, I2, de 0,05 a 10 g/10 min;en donde dicha mezcla tiene;wherein said mixture has;1) a melt index, I2, of 0.05 to 20 g / 10 min;1) un índice de fusión, I2, de 0,05 a 20 g/10 min;2) a flexural modulus of <210 MPa (30,000 psi);2) un módulo a la flexión de < 210 MPa (30.000 psi);3) a melt strength of> 2 cN at 190 ° C;3) una resistencia del fundido de > 2 cN a 190°C;4) a melt extensibility of> 25 mm / s;Y 4) una extensibilidad del fundido de > 25 mm/s;y 5) en donde dicha resistencia del fundido de dicha mezcla cumple la siguiente desigualdad;5) wherein said melt strength of said mixture meets the following inequality;Melt strength> FMS* [(f * A) + ((1-f) * B)] where: Resistencia del fundido > FMS* [(f*A) + ((1-f)*B)] donde: A = 3,3814*(1/I2)0·6476 y B = 10(1,2896-0,4278*log10(I2»;donde A = 3.3814 * (1 / I2)0·6476 and B = 10(1,2896-0,4278*log10(I2»;where I2 es el índice de fusión medido de la mezcla;f es la fracción en peso del polietileno lineal en la mezcla y FMS es > 1,1. I2 is the measured melt index of the mixture;f is the weight fraction of linear polyethylene in the mixture and FMS is> 1.1. 6. The mixture of claim 5, wherein;6. La mezcla de la reivindicación 5, en la que;A) Component A is a heterogeneous or homogeneous linear ethylene homopolymer or an interpolymer of ethylene with at least one α-olefin C3-C20, and has a melting index, I2, less than 60 g / 10 min, and where said mixture has: A) el Componente A es un homopolímero de etileno lineal heterogéneo u homogéneo o un interpolímero de etileno con al menos una α-olefina C3-C20, y tiene un índice de fusión, I2, menor que 60 g/10 min, y en donde dicha mezcla tiene: 1) a melt index, I2, of 0.1 to 10 g / 10 min;1) un índice de fusión, I2, de 0,1 a 10 g/10 min;2) a flexural modulus of <175 MPa (25,000 psi);2) un módulo a la flexión de < 175 MPa (25.000 psi);3) a melt strength of> 7 cN at 190 ° C;3) una resistencia del fundido de > 7 cN a 190°C;4) a melt extensibility of> 50 mm / s;Y 4) una extensibilidad del fundido de > 50 mm/s;y 5) FMS es > 1,25. 5) FMS is> 1.25. 7. The mixture of claim 5, wherein;7. La mezcla de la reivindicación 5, en la que;A) Component A is a linear ethylene homopolymer or an ethylene / α-olefin interpolymer C3-C8 linear or substantially linear, and wherein said component has a melt index, I2, less than 30 g / 10 min, and A) el Componente A es un homopolímero de etileno lineal o un interpolímero de etileno/ α-olefina C3-C8 lineal o sustancialmente lineal, y en donde dicho componente tiene un índice de fusión, I2, menor que 30 g/10 min, y B) component B is LDPE;wherein said mixture has;B) el componente B es LDPE;en donde dicha mezcla tiene;1) a melt index, I2, of 0.2 to 7 g / 10 min;1) un índice de fusión, I2, de 0,2 a 7 g/10 min;2) a flexural modulus of <140 MPa (20,000 psi);2) un módulo a la flexión de < 140 MPa (20.000 psi);ES 2 295 337 T3 ES 2 295 337 T3 3) 3) 4) a melt strength of> 10 cN at 190 ° C;4) una resistencia del fundido de > 10 cN a 190°C;a melt extensibility of> 75 mm / s;Y una extensibilidad del fundido de > 75 mm/s;y 5) 5) FMS es > 1,5. FMS is> 1.5. 8. The blend of claim 7, wherein Component A has a melt index, I2, less than 15 g / 10 min, and wherein said blend has;8. La mezcla de la reivindicación 7, en la que el Componente A tiene un índice de fusión, I2, menor que 15 g/10 min, y en donde dicha mezcla tiene;1) a melt index, I2, of 0.5 to 5 g / 10 min;Y 1) un índice de fusión, I2, de 0,5 a 5 g/10 min;y 2) FMS es > 2,5. 2) FMS is> 2.5. 9. The blend of claim 8, optionally comprising one or more additional polymers selected from the group consisting of low-density polyethylene (LDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), ethylene interpolymers, and styrene (ESI), polypropylene (PP), polystyrene (PS), ethylene-propylene rubber and styrene-butadiene rubber. 9. La mezcla de la reivindicación 8, que comprende opcionalmente uno o más polímeros adicionales seleccionados del grupo que consiste en polietileno de baja densidad (LDPE), polietileno de alta densidad (HDPE), polietileno lineal de baja densidad (LLDPE), interpolímeros de etileno y estireno (ESI), polipropileno (PP), poliestireno (PS), caucho de etileno-propileno y caucho de estireno-butadieno. 10. A foam formed from the mixture of any one of claims 5 to 9. 10. Una espuma formada a partir de la mezcla de una cualquiera de las reivindicaciones 5 a 9. 11. Una espuma que comprende la mezcla de la reivindicación 9, siendo dicha espuma o bien: eleven. A foam comprising the mixture of claim 9, said foam being either: 1) substantially uncrosslinked, having a gel content of 50 percent by weight or less gel, based on the total weight of the foam, measured according to ASTM D-2765-84, Method A;O well 1) sustancialmente no reticulada, teniendo un contenido en gel de 50 por ciento en peso o menos de gel, basado en el peso total de la espuma, medido según la norma ASTM D-2765-84, Método A;o bien 2) substantially cross-linked, having a gel content greater than 50 percent by weight of gel based on the total weight of the foam, measured according to ASTM D-2765-84 Method A. 2) sustancialmente reticulada, teniendo un contenido en gel mayor que 50 por ciento en peso de gel basado en el peso total de la espuma, medido según la norma ASTM D-2765-84 Método A. 12. An article formed from the foam of any one of claims 1 to 4, 10 or 11, wherein the article is selected from a shock absorbing packaging, a finished electronic good, an automotive article, a flotation device, thermal insulation , sound insulation, pipe insulation, insulation for refrigeration, insulation blankets for greenhouses, a component for footwear, a gasket or a medical device. 12. Un artículo formado a partir de la espuma de una cualquiera de las reivindicaciones 1 a 4, 10 ó 11, en donde el artículo se selecciona entre un embalaje amortiguador, un bien electrónico acabado, un artículo de automoción, un dispositivo de flotación, aislamiento térmico, aislamiento acústico, aislamiento de tuberías, aislamiento para refrigeración, mantas de aislamiento para invernaderos, un componente para calzado, una junta o un dispositivo médico. 13. A film, fiber, blow molded article or extrusion coating prepared from the blend of claim 5, or the foam of claim 1. 13. Una película, fibra, artículo moldeado por soplado o revestimiento por extrusión preparado a partir de la mezcla de la reivindicación 5, o la espuma de la reivindicación 1.
Independent claims6
333 paragraphs in 18 sections, as filed
ES 2 295 337 T3
DESCRIPTION
Ethylene polymer blends with improved modulus and melt strength and articles made from these blends.
This invention describes resin formulations having a flexural modulus greater than or equal to 700 MPa (100,000 psi) or less than 210 MPa (30,000 psi), which also give high previously inaccessible melt strengths at a melt index. given. This invention also provides articles of manufacture that include foams prepared from these resin formulations.
Blends of low density polyethylene (LDPE) and linear low density polyethylene (LLDPE) are known in the prior art. For example, Ghijsels et al., In "Melt Strength Behavior of Polyethylene Blends," Intern. Polymer Processing VII (1992), p. 44-50, provides examples of blends of LDPE and LlDPE, where LLDPE has a melt index (I2) of 0.1 g / 10 min and the densities of the final blends are approximately 0.92 g / cm<sup>3</sup>, and showing a synergistic improvement in melt strength. A polyethylene resin density of 0.92 g / cm<sup>3</sup> corresponds approximately to a flexural modulus of 280 MPa (40,000 psi). However, Ghijsels neither provides examples nor does it give any indication of the range of ethylenic components of blends in which synergy would be observed for blends having a flexural modulus greater than or equal to 700 MPa (100,000 psi) nor less than 210 MPa (30,000 psi).
US Patent No. 5,863,665 discloses an ethylene polymer composition for extrusion comprising 75 to 95 percent by weight of the total composition of at least one homogeneously branched linear ethylene / α-olefin interpolymer composition, wherein the homogeneously branched linear ethylene / α-olefin polymer is characterized as having a density in the range of 0.85 g / cm<sup>3</sup> at 0.940 g / cm<sup>3</sup> and from 5 to 25 percent by weight of the total composition of at least one high pressure ethylene polymer characterized by having a melt index, I2, less than 6.0 g / 10 minutes, a density of at least 0.916 g / cm<sup>3</sup>, a melt strength of at least 9 cN, determined using a Gottfert Rheotens unit at 190 ° C, a Mw / Mn ratio of at least 7.0, and a bimodal molecular weight distribution determined by gel permeation chromatography, and wherein the polymeric ethylene extrusion composition has a melt index, I2, of at least 1.0 g / 10 minutes. Blends of this composition would have a flexural modulus of less than 805 MPa (115,000 psi). Furthermore, this patent does not teach, exemplify, or claim foams.
International patent application WO 01/40374 is directed to compositions of grafted blends and, in particular, to foams formed from such grafted blends. Example 38 describes a blend having a flexural modulus of 1198 MPa (171,186 psi). However, the mixture includes a crosslinking agent as an essential component. There is no description of non-crosslinked foams that meet the requirements of the present invention.
US Patent No. 4,649,001 describes a process for producing an extruded polyethylene foam, which comprises melting and kneading a polyethylene-based resin composition containing a foaming agent, followed by extrusion-foaming. A linear low-density polyethylene having a broad molecular weight distribution is used as the polyethylene-based resin. The linear low-density polyethylene used has a density of 0.920 to 0.940 g / cm<sup>3</sup>, a melt flow rate of 0.3 to 10 g / 10 min and a ratio between a weight average molecular weight and a number average molecular weight (Mw / Mn) greater than or equal to 4. A polyethylene can also be mixed low density 0.918 to 0.923 g / cm<sup>3</sup> to prepare foams. All foams were extruded. Crosslinked foams were not claimed. The highest flexural modulus of the resins used to prepare the extruded foams would correspond to approximately 840 MPa (120,000 psi) (at a resin density of 0.940 g / cm<sup>3</sup>), but this would not be a mix. Furthermore, the density of linear low-density polyethylene was 0.940 g / cm<sup>3</sup> or less.
US Pat. No. 5,582,923 discloses an ethylene polymer composition for extrusion comprising 75 to 95 percent of at least one ethylene / α-olefin interpolymer composition selected from the group consisting of a substantially linear ethylene polymer composition, a polymer composition of homogeneously branched linear ethylene and a polymeric composition of heterogeneously branched linear ethylene, (wherein the ethylene / α-olefin polymer is characterized as having a density in the range of 0.85 g / cm<sup>3</sup> at 0.940 g / cm<sup>3</sup>) and 5 to 25 percent of at least one high pressure ethylene polymer characterized by having a melt index, I2, less than 6.0 g / 10 minutes, a density of at least 0.916 g / cm<sup>3</sup>, a melt strength of at least 9 cN determined using a Gottfert Rheotens unit at 190 ° C, a Mw / Mn ratio of at least 7.0 and a bimodal molecular weight distribution determined by gel permeation chromatography, where the polymeric ethylene extrusion composition has a melt index, I2, of at least 1.0 g / 10 minutes. Blends of this composition would have a flexural modulus of less than about 805 MPa (115,000 psi). Furthermore, this patent does not teach, exemplify, or claim foams.
US Patent No. 4,226,946 describes polyethylene blend foams having a density of 48.1 to 240.3 kg / m<sup>3</sup> (3.0 to 15.0 pounds per cubic foot), a substantially closed cell structure and a mean compressive strength at 10 percent strain of 0.049 to 1.19 MPa (7 to 170 psi), preferably 0.049 to 0, 42 MPa (7 to 60 psi), and a means to prepare the same from mixtures of polyethylene and at least one blowing agent using gel extrusion technology. The polyethylene blend comprises 35 to 60 percent
ES 2 295 337 T3 weight percent of a low density branched polyethylene (a density of 0.910 to 0.930 g / cm<sup>3</sup>) mixed with 40 to 65 percent by weight of a linear polyethylene of intermediate density (a density of 0.931 to 0.940 g / cm<sup>3</sup>). The densities of the resulting mixtures would be less than 0.9365 g / cm<sup>3</sup> (corresponding to a flexural modulus less than 700 MPa (100,000 psi)) and greater than 0.9180 g / cm<sup>3</sup> (corresponding to a flexural modulus greater than 280 MPa (40,000 psi)).
However, there is still a need for resin compositions which, while achieving a required flexural modulus, can also exhibit high melt strength and / or melt extensibility, at a given melt index. The inventors have surprisingly found that certain compositions exhibit synergistic improvements in melt strength and, in some cases, even more surprisingly, melt extensibility at this melt strength. Branched resins cannot achieve the modulus possible with linear polyethylene resins, and linear resins would have to have a much lower melt index than branched resins of comparable melt strength. Furthermore, the melt strength achieved with the blends used in the present invention may exceed, at a given melt index, the melt strength achievable with any branched resin or linear resin at the same melt index and / or density. Accordingly, the blends used in the present invention exhibit greatly improved melt strength compared to a linear polyethylene resin of the same density.
The extrusion foaming process requires a sufficiently high melt strength resin to allow the bubble structure to maintain its integrity during the expansion process immediately after extrusion from the die. Before this invention, the only resins capable of meeting this requirement at the appropriate melt index for processing (I2> 0.5, preferably> 1 g / 10 min) were branched resins such as LDPE, or EVA. Therefore, the flexural modulus was limited to that obtainable with these branched resins (i.e., 560 MPa (80,000 psi) or less, equivalent to an LDPE of density less than or equal to about 0.930 g / cm<sup>3</sup>). It would be highly desirable to produce a foam using a higher modulus resin (> 700 MPa (100,000 psi)), as this allows the overall density of the foam to be reduced, while maintaining the compressive strength of the prepared higher density foam. from a branched resin (although this resin has the limitation of a lower modulus).
The present invention describes blends comprising branched resins (eg LDPE) and linear resins (eg LLDPE prepared, for example, by Ziegler and / or metallocene catalysts). These blends provide a unique combination of increased melt strength and modulus at a given melt index, I2. Optionally, specific blend formulations can also be selected to provide both a higher and a lower modulus than achievable with LDPE alone. Thus, this invention can provide flexural modulus blends greater than or equal to 700 MPa (100,000 psi) or less than 210 MPa (30,000 psi), at melt strengths similar to or greater than those associated with a linear LDPE or polyethylene that have a similar melt index I2.
The blends of the present invention are useful for making high modulus foams, the preparation of which requires high melt strength. The resulting high modulus compositions (ie greater than 700 MPa (100,000 psi) flexural modulus) are particularly suitable for the manufacture of crosslinked and non-crosslinked foams. Thus, the foams of the present invention have a compressive strength and load bearing capacity similar to that of foams prepared from branched polyethylenes, but the inventive foams have a significantly lower foam density (allowing up to a reduction of approximately four times the amount of resin, by weight, necessary to produce such foams). Furthermore, the upper service temperature of the foams of this invention can also be improved, resulting in a subsequent improvement in the dimensional stability of the foam. There are currently no resins available with this combination of properties.
The high modulus foams of the present invention comprise blends of a branched resin of high melt strength, of relatively low modulus, with a linear resin of higher density and therefore higher modulus, to give a final mixed resin of higher modulus. than 700 MPa (100,000 psi). Commercially available branched ethylenic resins cannot achieve this modulus.
Also included in the present invention are so-called "soft" foams. These foams comprise blends of a relatively low modulus, high melt strength branched resin with a linear resin of lower density and therefore lower modulus, to give a final mixed resin of flexural modulus less than 210 MPa ( 30,000 psi). Commercially available linear low-density polyethylene cannot achieve this modulus either. Ethylene copolymers such as ethylene-vinyl acetate (EVA) and ethylene-acrylic acid (EAA) may have a flexural modulus of less than 210 MPa (30,000 psi), but these resins are not thermally stable at high temperatures (that is, they degrade easily) and often result in significant discoloration and / or odor. Thus, these resins have only limited utility for non-crosslinked extruded foams.
According to one aspect of the present invention, there is provided a foam comprising a mixture of;
A) a heterogeneous or homogeneous linear ethylene homopolymer or interpolymer wherein the homopolymer or interpolymer has a density greater than or equal to 0.944 g / cm<sup>3</sup> and a melt index, I<sub>2</sub>, less than 10 g / 10 min
ES 2 295 337 T3
B) a branched ethylene homopolymer or interpolymer selected from the group consisting of LDPE, EVA and EAA, and wherein the homopolymer or interpolymer has a melt index, I2, of 0.05 to 10 g / 10 min; and wherein said mixture has;
1) a melt index, I2, of 0.05 to 20 g / 10 min;
2) a flexural modulus of> 700 MPa (100,000 psi);
3) a melt strength of> 10 cN;
4) a melt extensibility of> 25 mm / s;
5) an upper service temperature (TSS) greater than 115 ° C; Y
6) wherein said melt strength of said mixture meets the following inequality;
Melt strength> F<sub>MS</sub>* [(f * A) + ((1-f) * B)] where A = 3.3814 * (1 / I2)<sup>0</sup>·<sup>6476</sup> and B = 10 <sup>7</sup>'·<sup>9 4</sup>'* ··'; I2 is the measured melt index of the mixture; f is the weight fraction of the linear component in the mixture and F<sub>MS</sub> is> 1.1, and wherein the mixture is substantially uncrosslinked.
According to a further aspect of the present invention, there is provided a mixture comprising;
A) a heterogeneous or homogeneous linear ethylene homopolymer or interpolymer wherein the homopolymer or interpolymer has a flexural modulus of less than 196 MPa (28,000 psi);
B) a branched ethylene homopolymer or interpolymer selected from the group consisting of LDPE, EVA and EAA, and wherein the homopolymer or interpolymer has a melt index, I2, of 0.05 to 10 g / 10 min; wherein said mixture has;
1) a melt index, I2, of 0.05 to 20 g / 10 min;
2) a flexural modulus of> 210 MPa (30,000 psi);
3) a melt strength of> 2 cN;
4) a melt extensibility of> 25 mm / s;
5) wherein said melt strength of said mixture meets the following inequality;
Melt strength> F<sub>MS</sub>* [(f * A) + ((1-f) * B)] where: A = 3.3814 * (1 / I2)<sup>0</sup>·<sup>6476</sup> and B = 10 <<sup>1</sup>·<sup>2896</sup>-<sup>Ο</sup>·<sup>4278</sup>*<sup>1</sup>°8<sup>1Ο</sup>(<sup>12</sup>));
where: I2 is the measured melt index of the mixture; f is the weight fraction of the linear component in the mixture and FMs is> 1.1.
Definitions
All references cited herein with respect to elements or metals belonging to a given Group refer to the Periodic Table of Elements published and registered by CRC Press, Inc., 1989. In addition, any reference to the Group or Groups will be to Group or Groups as reflected in this Periodic Table of the Elements, using the IUPAC system to number the groups.
Any numerical value mentioned herein includes all values from the lowest value to the highest value in increments of one unit, provided there is a separation of at least 2 units between any lower value and any higher value. For example, if the amount of a component or the value of a process variable, such as temperature, pressure and time, is indicated as, for example, 1 to 90, preferably 20 to 80, more preferably 30 to 70, it is understood that values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 etc. they are expressly listed in this specification. For values that are less than one, one unit will be considered 0.0001, 0.001, 0.01 or 0.1 as appropriate. These are only examples of what is specifically intended, and all possible combinations of numerical values between the lowest value and the highest value listed will be considered expressly set forth in this application in a similar manner.
ES 2 295 337 T3
The term "hydrocarbyl" as used herein means any aliphatic, cycloaliphatic, aromatic, aryl substituted aliphatic, aryl substituted cycloaliphatic, aliphatic substituted aromatic, or aliphatic group substituted cycloaliphatic.
The term "hydrocarbyloxy" means a hydrocarbyl group that has an oxygen bond between it and the carbon atom to which it is attached.
The term "interpolymer" is used herein to denote a polymer in which at least two different monomers are polymerized to obtain the interpolymer. This includes copolymers, terpolymers, etc.
The term "soft foam" is used herein to indicate a foam having an Asker C hardness of less than 30, preferably less than 25, and most preferably less than 20. The hardness of the present foams was measured using an Asker durometer. C for cellular rubber and thread according to ASTM D224097 (but with a 5 mm diameter spherical indenter).
The Melt Index (I2, g / 10 min) was determined by the ASTM D-1238 standard (190 ° C / 2.16 kg).
Density (g / cm<sup>3</sup>) was determined by ASTM D-792.
Flexural Modulus was measured by ASTM D-790-91, Method 1, Procedure B. A rectangular cross-section bar was tested using a three-point loading system and a 4.54 kg load cell ( 10 pounds).
Melt Tension - The melt tension (in grams) was measured at 190 ° C using a 2.16 kg load and drawing strands of molten polymers at 50 rpm around a pulley system for a drag speed along a period of thirty seconds. The melt stress was the mean force throughout this period.
Melt Strength (RF, measured in cN) and Melt Extensibility (EF, measured in mm / s) - Measurements were made by stretching strands of melted polymers or blends at constant acceleration until breakage occurred. The experimental equipment consisted of a capillary rheometer and a Rheotens apparatus as a tensioning device. The force required to uniaxially extend the strands was recorded as a function of tensioning speed. The maximum force achieved before the elongation resonance or break occurred was defined as the melt strength. The rate at which the stretch resonance or break occurred was defined as the melt extensibility. The stretch resonance, which ended in breakage, was indicated by the beginning of a periodic oscillation of increasing amplitude in the measured force profile. In the absence of any observable stretch resonance, the melt strength was defined as the force at break. These tests were carried out under the following conditions:
<td>• Mass flow:</td><td>1.35 grams / min</td>
<td>• Temperature:</td><td>190 ° C</td>
<td>• Capillary length:</td><td>41.9 mm</td>
<td>• Capillary diameter:</td><td>2.1 mm</td>
<td>• Piston diameter:</td><td>9.54 mm</td>
<td>• Piston speed:</td><td>0.423 mm / s</td>
<td>• Shear rate:</td><td>33.0 s<sup>-1</sup></td>
<td>• Stretch reduction distance (from nozzle outlet to tensioning wheels):</td><td>100 mm</td>
<td>• Cooling conditions:</td><td>ambient air</td>
<td>• Acceleration:</td><td>2.4 mm / s<sup>2</sup></td>
Upper Service Temperature (TSS) - A thermomechanical analyzer (ATM) commercially available from Perkin Elmer Corporation under the trade designation TMA 7 was used to measure the upper service temperature (TSS) of the polymers and blends. A probe force of 102 g was used and a heating rate of 5 ° C / min. Each test sample was a 3.3mm thick 7.8mm diameter disc, prepared by compression molding at 205 ° C and cooling in air to room temperature. The temperature at the penetration of the 1 mm probe was taken as the upper service temperature (TSS).
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Mixing compositions
The blend compositions of the present invention comprise one or more linear homopolymers or interpolymers (Component A) and one or more branched homopolymers or interpolymers (Component B).
Component A
Linear homopolymers or interpolymers that comprise Component A are those prepared using so-called coordination catalysis, which includes Ziegler and metallocene-type catalytic systems. Linear interpolymers can be further divided into homogeneous or heterogeneous polymers, depending on how the comonomer is distributed within the interpolymer molecules.
Linear homogeneous polymers and interpolymers used as Component A in blends of the present invention are defined herein as defined in US Patent 3,645,992 (Elston). Accordingly, homogeneous polymers and interpolymers are those in which the comonomer is randomly distributed within a given interpolymer molecule, and where substantially all of the interpolymer molecules have the same ethylene / comonomer ratio within that interpolymer. Homogeneous polymers have a narrow composition distribution.
The term "narrow composition distribution" used herein describes the comonomer distribution for homogeneous interpolymers, and means that homogeneous interpolymers have only a single melting peak and are essentially devoid of a measurable linear polymer fraction. Homogeneous narrow composition distribution interpolymers can also be characterized by their SCBDI (short chain branch distribution index) or CDBI (composition distribution width index). SCBDI or CBDI is defined as the percentage by weight of polymer molecules that have a comonomer content within 50 percent of the mean total molar comonomer content.
The CDBI of a polymer is easily calculated from data obtained from techniques known in the art, such as, for example, fractionation by increasing elution temperature (abbreviated herein as "TREF"), as described , for example, in Wild et al., Journal of Polymer Science, Poly. Phys. Ed., Vol. 20, p. 441 (1982), or in US Patent 4,798,081, and US Patent No. 5,008,204 and International Patent Application WO 93/04486. The SCBDI or CDBI for the narrow composition distribution homogeneous interpolymers and copolymers of the present invention is preferably greater than 30 percent, especially greater than 50 percent. The narrow composition distribution homogeneous interpolymers and copolymers used in this invention essentially lack a "measurable high density fraction" (ie, homopolymer) as measured by the TREF technique. Linear homogeneous polymers and interpolymers also have a degree of branching less than or equal to 2 methyls / 1000 carbons by 15 percent (by weight) or less, preferably less than 10 percent (by weight), and especially less than 5 percent. percent (by weight).
Useful linear homogeneous homopolymers or interpolymers also include so-called substantially linear polymers defined as in US Patent No. 5,272,236 (Lai et al.), And in US Patent No. 5,278,272. .
Linear heterogeneous homopolymers and interpolymers can also be used as Component A in the blends of the present invention. Heterogeneous interpolymers are those in which substantially all of the interpolymer molecules do not have the same ethylene / comonomer ratio and have a broad compositional distribution.
The term "broad composition distribution" used herein describes the comonomer distribution for heterogeneous interpolymers, and means that heterogeneous interpolymers have a "linear" fraction and that heterogeneous interpolymers have multiple melting peaks (ie, they exhibit at least two different melting peaks). Linear heterogeneous polymers and interpolymers also have a degree of branching less than or equal to 2 methyls / 1000 carbons by 10 percent (by weight) or more, preferably more than 15 percent (by weight), and especially more than 20 percent. percent (by weight). Heterogeneous interpolymers also have a degree of branching equal to or greater than 25 methyls / 1000 carbons by 25 percent or less (by weight), preferably less than 15 percent (by weight) and especially less than 10 percent (by weight). of the total polymer.
The linear homogeneous and heterogeneous polymers and interpolymers used to prepare the new polymer compositions used in the present invention can be ethylene homopolymers or ethylene interpolymers with at least one α-olefin C<sub>3</sub>-C<sub>20</sub>. Preferred monomers include ethylene, 1-propene, 1-butene, 1-hexene, 4-methyl-l-pentene, and 1-octene. Other preferred monomers include styrene, halo- or alkyl-substituted styrenes, vinylbenzocyclobutane, 1,4-hexadiene, cyclopentene, cyclohexene, and cyclooctene.
Component B
The branched polymers and interpolymers used as Component B in the blends of the present invention are defined herein as those that are partially or fully homopolymerized or interpolymerized in autoclave or tubular reactors at pressures above 101.5 MPa (14,500 psi ) with the use of free radical initiators.
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Such branched polymers and interpolymers include, but are not limited to, low density ethylene polymers such as high pressure low density ethylene homopolymer (LPDE), ethylene vinyl acetate copolymer (EVA), ethylene acid copolymer acrylic (EAA), ethylene-carboxylic acid copolymers and ethylene-acrylate copolymers, as well as olefinic polymers produced at low to medium pressures such as polybutylene (PB).
Suitable high pressure ethylene interpolymers include ethylene interpolymerized with at least one jd-ethylenically unsaturated comonomer (eg, acrylic acid, methacrylic acid, and vinyl acetate) as described by McKinney et al. in US Patent No. 4,599,392. Preferred high pressure ethylene interpolymers comprise 0.1 to 55 percent by weight of total comonomer, and more preferably 1 to 35 percent by weight of total comonomer, and most preferably 2 to 28 percent. by weight of the total comonomer, and can be chemically and / or physically modified by any known technique such as, for example, by ionomerization and extrusion grafting.
Suitable branched ethylenic polymers, Component B, include EVA, LDPE and EAA of melt index 0.05-10 g / 10 min. LDPE is most preferable.
Properties of the Mixing Compositions of the Present Invention
The blends of the present invention may be prepared by any suitable means known in the art such as, for example, dry blending in a pellet form in the desired proportions followed by melt blending in apparatus such as a screw extruder or Banbury mixer. Dry mixed pellets can be melt processed directly to a final solid state article by, for example, extrusion or injection molding. Mixtures can also be obtained by direct polymerization without isolation of the components of the mixture. Direct polymerization can use, for example, one or more catalysts in a single reactor or in two or more reactors in series or parallel, and vary at least one of the operating conditions, such as the choice of monomer mixtures and the catalyst. Mixing branched and linear resins at melt temperatures greater than 230 ° C can lead to a further increase in melt strength.
The inventors have unexpectedly found that by mixing certain branched polyethylene resins with linear polyethylene resins of higher density, they obtain a mixture of resins of a certain range of melt indexes with the necessary melt strength to allow production of foams.
This melt strength is synergistically much higher than expected from a linear combination of the two components.
The melt strength of the mixture meets the following inequality;
Melt strength> F<sub>MS</sub>* [(f * A) + ((1-f) * B)] where:
A = 3.3814 * (1 / I2)<sup>0</sup>·<sup>6476</sup> Y
B = 10 (1.2896-0.4278 * log10 (I2))
Where I2 is the measured melt index of the mixture; f is the weight fraction of linear polyethylene (Component A) in the mixture.
F<sub>ms</sub> it is a measure of the synergy in melt strength in a mix. When F<sub>MS</sub> = 1.0, the blend exhibits no synergistic improvement in melt strength. When F<sub>MS</sub> > 1, the blend is synergistic in that it exhibits greater melt strength than expected (or predicted) from a blend of linear and branched ethylenic polymers at the blend's melt index.
For the mixtures of the present invention, F<sub>MS</sub> it is> 1.1, preferably> 1.25, more preferably> 1.5, even more preferably> 2.0, most preferably> 2.5.
The final melt index, I2, of the blend composition is 0.05 to 20, preferably 0.1 to 10, more preferably 0.2 to 7, even more preferably 0.5 to 5 g / 10 min .
The final melt strength of the blend composition is greater than or equal to 10 cN.
The final melt extensibility of the blend composition is greater than or equal to 25, preferably greater than or equal to 50, most preferably greater than or equal to 75 mm / s.
The final flexural modulus of the blend composition is greater than or equal to 700 MPa (100,000 psi), more preferably greater than or equal to 840 MPa (120,000 psi), and most preferably greater than or equal to 910 MPa (130,000 psi). psi).
In another embodiment, the final flexural modulus of the blend composition is less than or equal to 210 MPa (30,000 psi), preferably less than or equal to 175 MPa (25,000 psi), and most preferably less than or equal to 140 MPa (20,000 psi).
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For mixtures with flexural modulus greater than or equal to 700 MPa (100,000 psi), the upper service temperature (TSS) of the mixtures will be greater than 115 ° C, preferably greater than 118 ° C, more preferably greater than 121 ° C and even more preferably greater than 125 ° C.
The melt index, I2, of Component A is less than 10 g / 10 min.
For mixtures with flexural modulus greater than or equal to 700 MPa (100,000 psi), the linear resin, Component A, should have a modulus greater than 966 MPa (138,000 psi) (equivalent to a density of ~ 0.944 g / cm<sup>3</sup>), preferably greater than 1148 MPa (164,000 psi) (equivalent to a density of ~ 0.9500 g / cm<sup>3</sup>), more preferably greater than 1470 MPa (210,000 psi) (equivalent to a density of ~ 0.9600 g / cm<sup>3</sup>). Most preferred, Component A is an ethylene homopolymer.
For mixtures with flexural modulus less than or equal to 210 MPa (30,000 psi), Component A should have a modulus less than 196 MPa (28,000 psi), preferably less than 175 MPa (25,000 psi), more preferably less than 154 MPa (22,000 psi). Again, for these blends it is preferred that Component A is an ethylene homopolymer.
The blends of the present invention may optionally comprise additional polymers, including one or more other thermoplastics to provide additional improvements in properties, including, but not limited to, processability, upper service temperature, modulus, compressive strength, toughness. , toughness, increased cell size of the foam, and aesthetics of the final foams or articles made from them. Examples of additional polymers include, but are not limited to, Low Density Polyethylene (LDPE), High Density Polyethylene (HDPE), Linear Low Density Polyethylene (LLDPE), Ethylene Styrene Interpolymers (ESI), Polypropylene ( PP), polystyrene (PS), ethylene-propylene rubber and styrene-butadiene rubber. In one embodiment, the blends of the present invention may be further blended with alkenyl aromatic polymers (such as polystyrene) to prepare, for example, alkenyl aromatic polymer foams with increased cell size.
Applications of these blends include those where melt strength, modulus, and / or higher service temperature are key performance requirements, for example non-crosslinked foams for shock-absorbing packaging, sports and leisure, building and construction, etc. .; blow molded non-crosslinked articles; cross-linked foams for applications such as the automotive industry; non-cross-linked foam labels for bottles; films; fibers; and extrusion coatings.
The foams of the present invention
The present invention provides blends with a flexural modulus above about 700 MPa (100,000 psi) simultaneously with high melt strength and high melt extensibility at comparatively higher melt indices, thereby broadening the applicability of resin resins. high density in foam structures and in procedures not previously achievable or feasible with traditional linear or substantially linear polyethylene. It is not possible to achieve these combinations of RF, EF and IF using linear polymers with flexural modulus of 700 MPa (100,000 psi) or more. With a branched ethylenic polymer, it is possible to achieve RF and EF but the flexural modulus will be 560 MPa (80,000 psi) or less.
The present invention also provides blends with a flexural modulus of less than 210 MPa (30,000 psi) simultaneously with high melt strength and high melt extensibility at comparatively higher melt indices, thereby broadening the applicability of low-grade resins. density in foam structures and in procedures not previously achievable or feasible with traditional linear polyethylene. These combinations of melt strength, high melt extensibility, and melt index cannot be achieved using linear polymers with flexural modulus of 210 MPa (30,000 psi) or less. With a branched ethylenic polymer other than EVA, RF and EF cannot be achieved and the flexural modulus will be greater than 210 MPa (30,000 psi). In the case of EVA such benefits only come with unacceptable additional properties such as thermal instability and odor.
The flexural modulus of these mixtures is higher than previously described in the prior art, giving greater stiffness and therefore greater compressive strength than existing compositions, but nevertheless with the melt strength and elongation viscosity required to allow satisfactory manufacture in foams. The reduced amount of resin required in these foams results in economic and environmental advantages over current technology. At any given melt index, no previously described polyethylene provides the combination of melt strength, extensibility, and modulus above about 700 MPa (100,000 psi) described in this invention.
To prepare commercially acceptable foams of any modulus, it is necessary to have a minimum melt strength of about 2 cN, preferably greater than 7 cN and most preferably greater than 10 cN, and a minimum extensibility of 25 mm / s, preferably greater than 50 mm / s and most preferably greater than 75 mm / s. LDPE resins exhibit these properties but cannot give the required modulus (greater than 700 (100,000 psi) or alternatively less than 210 MPa (30,000 psi)) or stiffness. HDPE or LLDPE resins can only achieve the required melt strength at a melt index (I2) <3 g / 10 min, often <1 g / 10 min.
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This causes difficulties in the processability of the foam, for example due to excessive shear heating.
This very high melt strength is a necessary requirement for successful foam production, and is greater than that required for branched resins such as LDPE, and is not achievable at the same melt index and density with previously known branched polyethylenes. This is particularly true for the high modulus foams of the present invention, a result of the higher foaming temperature required due to the increased melting point of the higher density resin, and the increased amount of blowing agent required to create the lower density foam product, both of which tend to reduce the viscosity of the extrudate. Without the high strength of the melt, the foam would collapse due to the collapse of the cellular structure of the foam before solidification, for example, a foam, prepared with a high pressure LDPE, of density 32.04 kg / m<sup>3</sup> (2.0 lbs / p cub) can be replaced by a foam, prepared with a resin of this new composition, of density 8.01 kg / m<sup>3</sup> (0.5 lb / ft cub) but with similar compressive strength.
The foams will comprise 0.05 to 100, preferably 0.1 to 100 and most preferably 0.2 to 100 percent by weight of the mixture of Components A and B (based on the total amount of polymers present in the foam) .
The polymer compositions described above can be made into foam products using physical and / or chemical blowing agents and any conventional procedures. Foam products include, for example, extruded thermoplastic polymer foam, extruded strand polymer foam, expandable thermoplastic foam beads, expanded thermoplastic foam beads, and molten thermoplastic foam beads, and various types of crosslinked foams. Foam products can have any known physical configuration, such as sheet, round, strand, bar, solid sheet, laminate sheet, stranded sheet, profiled, and box-shaped geometry. Foam products can be made into articles made using any of the conventional methods or procedures. For example, any one or more of expansion, bonding and welding may be used in the manufacture of such articles, especially from expandable foam beads. Expandable beads can also be molded into any known configuration employing foam products, including but not limited to the above configurations.
The foaming process steps are well known in the art. For example, as exemplified by the teachings of ethylenic polymer foam structure preparation and processing procedures described in CP Park, "Polyolefin Foam," Chapter 9, Handbook of Polymer Foams and Technology, ed. D. Klempner and KC Frisch, Hanser Publishers, Munich, Vienna, New York, Barcelona (1991).
The foams of the present invention can be substantially uncrosslinked. That is, the foam structure contains 50 or less, preferably 40 or less, more preferably 30 or less, even more preferably 20 or less, most preferably 10 percent by weight or less of gel based on the total weight of the foam or polymer, measured by Method A of ASTM D2765-84.
Alternatively, the polymeric compositions can be used to make foams that are substantially cross-linked (that is, containing more than 50 percent by weight of gel based on the total weight of the polymer, as measured by ASTM Method A D2765-84) by the subsequent addition of any known crosslinking agent. The various crosslinking agents and their technologies are described in the art. Crosslinking can be induced by the addition of a crosslinking agent. The induction of crosslinking and exposure to elevated temperatures to effect foaming or expansion may take place simultaneously or sequentially. If a chemical crosslinking agent is used, it is incorporated into the polymeric material in the same way as the chemical blowing agent. Furthermore, if a chemical crosslinking agent is used, the foamable molten polymeric material is heated or exposed to a temperature preferably less than 150 ° C to avoid decomposition of the crosslinking agent or the blowing agent and to prevent premature crosslinking. If radiation crosslinking is used, the foamable molten polymeric material is heated or exposed to a temperature preferably less than 160 ° C to prevent decomposition of the blowing agent. The foamable melt polymeric material is extruded or passed through a die in the desired shape to form a foamable structure. The foamable structure is then crosslinked and expanded at an elevated or high temperature (typically 150 ° C to 250 ° C) such as in an oven to form a foam structure. If radiation crosslinking is used, the foamable structure is irradiated to crosslink the polymeric material, which is then expanded at the elevated temperature as described above. The present structure can advantageously be prepared in sheets or thin plates according to the above procedure using either crosslinking agents or radiation.
The foam structures of the present invention are optionally prepared by a conventional extrusion foaming process. The structure is advantageously prepared by heating the polymer or mixture to form a molten polymeric material, incorporating therein a blowing agent to form a foamable gel, and extruding the gel through a die to form the foam product. Depending on the nozzle (with an appropriate number of openings) and the operating conditions, the product can vary from an extracted sheet or foam stick, through a bonded foam strand product, to foam beads and eventually to chopped strands. of foamable pearls. Before mixing with the blowing agent, the polymeric material is heated to a temperature at or above its glass transition temperature or melting point. The blowing agent is optionally incorporated or mixed with the polymeric material in the molten state
ES 2 295 337 T3 by any of the means known in the art such as with an extruder, mixer, kneader, or the like. The blowing agent is mixed with the molten polymeric material at a high pressure sufficient to prevent substantial expansion of the molten polymeric material and advantageously to disperse the blowing agent homogeneously therein. Optionally, a nucleating agent is mixed into the polymer melt or dry mixed with the polymeric material prior to melting or plasticizing. Before extruding the foamable gel through the die, the gel is typically cooled to an optimum temperature. The foamable gel is typically cooled to a lower temperature to optimize the physical characteristics of the foam structure. This temperature, often referred to as the foaming temperature, is typically above the glass transition temperature (T<sub>g</sub>) of each of the polymer components or for those with sufficient crystallinity, close to the maximum crystalline melting temperature (T<sub>m</sub>). "Next" means to, above or below and depends largely on where the stable foam exists. The temperature desirably falls within 30 degrees centigrade (° C) above or below the Tm. For the foams of the present invention, an optimal foaming temperature is in the range in which the foam does not collapse. The gel can be cooled in the extruder or other mixing device or in separate coolers. The gel is then extruded or conveyed through a die in the desired shape to a zone of reduced or lower pressure to form the foam structure. The lower pressure zone is at a lower pressure than that in which the foamable gel is held prior to extrusion through the die. The lower pressure can optionally be superatmospheric or subatmospheric (vacuum), but is preferably at an atmospheric level.
In another embodiment, the resulting foam structure is optionally formed into strands joined by extruding the polymer material through a multi-hole die. The holes are arranged such that contact occurs between adjacent streams of the molten extrudate during the foaming process and the surfaces in contact adhere to each other with sufficient adhesion to result in a unitary foam structure. The molten extrudate streams exiting the die take the form of strands or profiles, which desirably foam, bond and adhere to one another to form a unitary structure. Desirably, the individual fused strands or profiles should remain adhered in a unitary structure to avoid delamination of the strands under the stresses that occur in preparing, shaping and using the foam. Apparatus and methods for the production of the foam structures in the form of bonded strands are shown in US Patent Nos. 3,573,152 and 4,824,720.
Alternatively, the resulting foam structure is conveniently formed by a build-up extrusion method and apparatus, as can be seen in US Patent Nos. 4,323,528 and 5,817,705. This apparatus, commonly known as an "extruder-accumulator system" allows a process to operate on an intermittent rather than continuous basis. The apparatus includes a maintenance zone or accumulator in which the foamable gel remains in conditions that prevent foaming. The maintenance area is equipped with an outlet nozzle that opens to a lower pressure area, such as the atmosphere. The nozzle has an orifice that can be open or closed, preferably by means of a hatch, which is external to the maintenance area. The operation of the hatch does not affect the foamable composition, other than that it allows it to flow through the nozzle. The opening of the hatch and the substantially simultaneous application of mechanical pressure to the gel by a mechanism (eg, a mechanical piston) forces the gel through the nozzle to a zone of lower pressure. The mechanical pressure is sufficient to force the foamable gel through the nozzle at a speed fast enough to prevent significant foaming within the nozzle, yet slow enough to minimize and preferably eliminate the generation of irregularities in the cross-sectional area. or in the form of foam. As such, apart from operating intermittently, the process and its resulting products closely resemble those manufactured in a continuous extrusion process.
In the build-up extrusion process, low-density foam structures having large lateral cross-sectional areas are prepared by: 1) forming a gel of the polymeric material or mixture and a blowing agent under pressure at a temperature at which the viscosity of the gel is sufficient to retain the blowing agent when the gel is allowed to expand; 2) Extrude the gel in a maintenance zone maintained at a temperature and pressure that does not allow the gel to foam, the maintenance zone having an outlet nozzle that defines an orifice that opens towards a zone of lower pressure to which the gel it is foamed, and a hatch capable of being opened that closes the orifice of the nozzle; 3) periodically open the hatch; 4) substantially simultaneously applying mechanical pressure by means of a movable piston on the gel to expel it from the heating zone through the nozzle orifice towards the zone of lower pressure, at a speed greater than that at which foaming occurs substantial in the nozzle orifice and less than that at which substantial irregularities in cross-sectional area or shape occur; and 5) allowing the expelled gel to expand without restriction in at least one dimension to produce the foam structure.
The present foam structures can also be formed into foam beads suitable for molding into articles by expanding pre-expanded beads containing a blowing agent. The beads can be molded at the time of expansion to form articles of various shapes. Procedures for preparing expanded beads and molded expanded bead foam articles are described in Plastic Foams, Part II, Frisch and Saunders, pp. 544-585, Marcel Dekker, Inc. (1973) and Plastic Materials, Brydson, 5<sup>to</sup> ed., pp. 426-429, Butterworths (1989). The expanded and expandable beads can be obtained by a batch or extrusion process, and can be substantially cross-linked or non-cross-linked.
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The batch process for making expandable beads is similar to the manufacture of expandable polystyrene (EPS). The resulting foam structure is formed into non-crosslinked foam beads suitable for molding into articles. Discrete resin particles, such as granules made from the mixtures of the present invention, prepared either by melt mixing or by reactor mixing, are impregnated with a blowing agent (and optionally a crosslinking agent) in an aqueous suspension or in an anhydrous state in a pressure vessel, at an elevated pressure and temperature. In the case of the aqueous suspension, the blowing agent (and optionally the crosslinking agent) is (are) introduced into the liquid medium in which the granules are substantially insoluble (such as water) at elevated pressure and temperature. , in an autoclave or other pressure vessel. The granules are either rapidly discharged to the atmosphere or a region of reduced pressure to expand the granules into foam beads, or they are cooled and discharged as unexpanded beads. In a separate step, the unexpanded beads are heated to expand them, for example, with steam or hot air. This procedure for making pearl foams is well taught in US Patent Nos. 4,379,859 and 4,464,484.
In a modification of the bead process, a styrene monomer is optionally impregnated into the suspended pellets of the blend compositions of the present invention prior to their impregnation with blowing agent to form a graft interpolymer with the polymeric material. The resulting interpolymer beads are cooled and discharged from the container substantially unexpanded. The beads are then expanded and molded by an expanded polystyrene bead molding process within the skill of the art. Such a process for preparing such polyethylene / polystyrene interpolymer beads is described, for example, in US Patent No. 4,168,353.
A variation of the foregoing extrusion process readily provides expandable thermoplastic polymeric beads. The method follows the conventional foam extrusion procedure described above to the nozzle hole, which now contains one or multiple holes. The variation requires (a) cooling the foamable gel to a temperature below that at which foaming occurs, (b) extruding the cooled gel through a die containing one or more holes to form a corresponding number of essentially continuous expandable thermoplastic strands, (c) optionally cooling the strands exiting the nozzle orifice in a cold water bath; and (d) and pelletizing the expandable thermoplastic strands to form expandable thermoplastic beads. Alternatively, the strands are made into foam beads by cutting the strands into pellets or granules on the face of the die and allowing the granules to expand.
Foam beads can also be prepared by preparing a mixture of the polymeric blend compositions of the present invention, crosslinking agent and chemical blowing agent in a suitable mixer or extruder device and pelletizing the mixture, and heating the pellets to expand them. and cross-link them.
In another process for preparing crosslinked foam beads suitable for casting into articles, the blends of this invention are melted and mixed with a physical blowing agent in conventional foam extrusion apparatus to form an essentially continuous foam strand. The foam strand is granulated or pelletized to form foam beads. The foam beads are then crosslinked by radiation. The crosslinked foam beads can then be melted and molded into various articles, as described above for the other foam bead processes. Additional teachings of this procedure can be found in US Patent No. 3,616,365 and in the earlier CP Park publication, pp. 224-228.
The foam beads can then be molded by any means known in the art, such as loading the foam beads into a mold, compressing the mold to compress the beads, and heating the beads, such as with steam, to effect coalescence. and melting the beads to form the article. Optionally, the beads can be impregnated with air or other blowing agent at elevated temperature and pressure prior to loading into the mold.
Additionally, the beads can optionally be heated prior to loading. The foam beads are then conveniently molded into blocks or shaped articles by a suitable molding method known in the art. Some of the methods are described in US Patent Nos. 3,504,066 and 3,953,558. Excellent teachings of the above molding procedures and methods can be seen in CP Park, supra, p. 191, pp. 197198, and pp. 227-233, in US Pat. No. 3,886,100, US Patent No. 3,959,189, US Patent No. 4,168,353, and US Patent No. 4,429,059.
The present cross-linked foam structure can also be prepared into a continuous slab structure by an extrusion process using a long fillet die as described in British patent application GB 2,145,961 A. In that process, the polymer, a chemical blowing agent and a crosslinking agent are mixed in an extruder, heating the mixture to allow the polymer to crosslink and decompose the chemical agent in a long fillet die; and shaping and removing the foam structure from the nozzle, the foam structure and the contact area of the nozzle being lubricated by a suitable lubricating material.
The present cross-linked foam structure can be prepared in a box shape by two different procedures. One procedure involves the use of a cross-linking agent and the other uses radiation.
The present crosslinked foam structure can be prepared in a box shape by mixing the mixtures of this invention, a crosslinking agent and a chemical blowing agent to form a sheet, heating the mixture in
ES 2 295 337 T3 a mold so that the crosslinking agent can crosslink the polymeric material and the blowing agent can be decomposed, and expanding the foam by releasing the pressure in the mold. Optionally, the box-shaped structure formed after pressure relief can be reheated to expand further.
Foam can be made from a crosslinked polymer sheet by irradiating the polymer sheet with a high energy beam or by heating a polymer sheet containing a chemical crosslinking agent. The crosslinked polymer sheet is cut into desired shapes and impregnated with nitrogen at a higher pressure at a temperature above the softening point of the polymer; When the pressure is released, bubble nucleation and some expansion occurs in the sheet. The sheet is reheated to a lower pressure above the softening point, and then the pressure is released to allow expansion of the foam.
Useful blowing agents for preparing the foam structures of the present invention include inorganic blowing agents, organic blowing agents, and chemical blowing agents. Suitable inorganic blowing agents include carbon dioxide, nitrogen, argon, water, air, oxygen, sulfur hexafluoride (SF6), and helium. Organic blowing agents include aliphatic hydrocarbons having 1-9 carbon atoms, aliphatic alcohols having 1-3 carbon atoms, and fully or partially halogenated aliphatic hydrocarbons having 1-4 carbon atoms. Aliphatic hydrocarbons include methane, ethane, propane, n-butane, isobutane, npentane, isopentane, and neopentane. Aliphatic alcohols include methanol, ethanol, n-propanol, and isopropanol. Fully or partially halogenated aliphatic hydrocarbons include chlorocarbons, fluorocarbons, and chlorofluorocarbons. Examples of fluorocarbons include methyl fluoride, perfluoromethane, ethyl fluoride, 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), 1,1,1-trifluoroethane (HFC-143a), 1,1, 1,2-tetrafluoroethane (HFC-134a), 1,1,2,2tetrafluoroethane (HFC-134), 1,1,1,3,3-pentafluoropropane, pentafluoroethane (HFC-125), difluoromethane (HFC-32), perfluoroethane, 2,2-difluoropropane, 1,1,1-trifluoropropane, perfluoropropane, dichloropropane, difluoropropane, perfluorobutane, perfluorocyclobutane. Chlorocarbons and partially halogenated chlorofluorocarbons for use in this invention include methyl chloride, methylene chloride, ethyl chloride, 1,1,1-trichloroethane, 1,1-dichloro-1-fluoroethane (HCFC-141b), 1-chloro-1-difluoroethane. (HCFC-142b), chlorodifluoromethane (CFC-22), 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123) and 1-chloro-1,2,2,2-tetrafluoroethane (HCFC-124). Fully halogenated chlorofluorocarbons include trichloromonofluoromethane (CFC-11), dichlorodifluoromethane (CFC-12), trichlorotrifluoroethane (CFC113), dichlorotetrafluoroethane (CFC-114), chloroheptafluoropropane, and dichlorohexafluoropropane. Chemical blowing agents include azodicarbonamide, azodiisobutyronitrile, barium azodicarboxylate, N, N'-dimethyl-N, N'-dinitrosoterephthalamide, and benzenesulfonylhydrazide, 4,4-oxybenzenesulfonylsemicarbazide, and tri-toluenesulfonylsemicarbazide, and p-toluenesulfonylsemic mixtures, and p-toluenesulfonylsemic hydrogen carbonate mixtures, sodium and citric acid, such as the various products marketed under the name Hydrocerol ™ (a Boehringer Ingelheim product). Any of the above blowing agents can be used individually or in association with one or more other blowing agents. Preferred blowing agents include isobutane, carbon dioxide, HFC-152a, and mixtures of the foregoing. The amount of blowing agent incorporated into the molten polymeric material to prepare a foaming polymeric gel is 0.05 to 5.0, preferably 0.2 to 3.0, and most preferably 0.5 to 2. .5 gram-mole per kilogram of polymer.
The foams are optionally perforated to enhance or accelerate the gas permeation exchange in which the blowing agent exits the foam and air enters the foam. The resulting perforated foams have a multiplicity of channels defined therein which are preferably free-running with respect to the longitudinal extent of the foam. The channels extend from one surface of the foam at least partially through the foam, and sometimes completely through the foam from an external surface to another external surface. The channels are advantageously present on substantially an entire outer surface of the foam, preferably with a uniform or substantially uniform spacing. Suitable spacing ranges can be up to and including 2.5 centimeters (cm), preferably up to and including 1.3 cm. The foams optionally employ a stability control agent of the type described above in association with perforation to allow permeation or accelerated release of the blowing agent while maintaining a dimensionally stable foam. US Patent No. 5,424,016, US Patent No. 5,424,016. No. 5,585,058, International Patent Application WO 92/19439 and International Patent Application WO 97/22455 provide excellent information regarding perforation. If desired, the foams of this invention may be post-treated by any known means to increase the content of open cells in the foam. Such post-treatment methods include, but are not limited to, mechanical compression of the foam and expansion of the foam by exposure to steam and / or hot air.
The foams of the present invention generally have a density less than 900, preferably less than 850, more preferably less than 800 kg / m<sup>3</sup>, even more preferably 5 to 700 kilograms per cubic meter, and most preferably 5 to 200 kilograms per cubic meter (according to ASTM D357593, Suffix W, Method B). The foams can be microcellular (that is, with a cell size of less than 0.05mm, preferably 0.001mm, to 0.05mm) or macrocellular (that is, a cell size of 0.05mm or more. ). The macrocellular foam has an average cell size of 0.05 to 15, preferably 0.1 to 10.0, and more preferably 0.1 to 5 millimeters, preferably 0.2 to 3 millimeters, and more preferably 0 , 2 to 2 millimeters measured according to ASTM D3576-77 procedures. The preferred ranges of cell size and density should not be construed as limiting the scope of this invention.
The foams of the present invention preferably exhibit excellent dimensional stability. Preferred foams recover 80 percent or more of the initial volume when measured one month after a measurement of
ES 2 295 337 T3 initial volume within 30 seconds after foam expansion. Volume is measured by a suitable method such as cubic water displacement.
The foams of the present invention have an open cell content ranging from 0 to 100 percent by volume based on the total volume of the foam, as measured by ASTM D2856-94, depending on component selection and variations in procedural conditions. Foams with an open cell content of 30 volume percent or less generally fall into a type known as closed cell foams. So-called open cell foams typically have an open cell content of greater than 30, preferably greater than 40, and more preferably greater than 50 percent by volume. The open cell content is desirably 100 volume percent or less, preferably 95 volume percent or less, and more preferably 90 volume percent or less.
Foams of density less than 100 kg / m<sup>3</sup> generally have an Asker-C hardness of <90, desirably <80, and preferably <70. Foam hardness measurements use an Asker C durometer for cellular rubber and yarn in accordance with ASTM D2240-97. , using a 5mm diameter spherical indenter.
If the foam is in the form of a sheet or board, it has a thickness that is generally> 0.5mm, preferably> 1mm and a width that is generally> 5mm, preferably> 10mm. As used herein, the "thickness" of a foam board or sheet refers to its smallest cross-sectional dimension (eg, measured from a flat surface to an opposite flat surface). When the foam is present as a circle or bar, it has a diameter that is generally> 5mm, preferably> 10mm.
The foam has an optimal drop test C factor (ASTM-D1596) of <6, desirably <5, and preferably <4.
Various additives can be incorporated into the compositions or foams of the present invention. Additives include, without limitation, stability control agents, nucleating agents, inorganic fillers, conductive fillers, pigments, colorants, antioxidants, acid scavengers, ultraviolet absorbers or stabilizers, flame retardants, treatment aids. , extrusion aids, antistatic agents, adhesion additives (eg, polyisobutylene), anti-block additives, other thermoplastic polymers. Some of the additives, such as inorganic and conductive fillers, can also function as nucleating agents and / or open cell promoters for foams. Examples of antioxidants are hindered phenols (such as, for example, Irganox ™ 1010) and phosphites (for example, Irgafos ™ 168) both trademarks of, and commercially available from, Ciba Geigy Corporation.
The additives are advantageously employed in functionally equivalent amounts known to those skilled in the art. For example, the amount of antioxidant used is that amount that prevents the polymer or polymer blend from undergoing oxidation at the temperatures and environment used during storage and end use of the polymers. Such an amount of antioxidant is usually in the range of 0.01 to 10, preferably 0.02 to 5, more preferably 0.03 to 2 percent by weight based on the weight of the polymer or polymer blend. Similarly, the amounts of any of the other listed additives are functionally equivalent amounts.
A nucleating agent is optionally added in order to control the cell size of the foam. Preferred nucleating agents include inorganic substances such as calcium carbonate, talc, clay, titanium dioxide, silica, barium stearate, calcium stearate, diatomaceous earth, and mixtures of citric acid and sodium bicarbonate. When used, the amount of nucleating agent employed advantageously ranges from 0.01 to 5 parts by weight per hundred parts by weight of a polymeric resin.
In making foams, a stability control agent (also known as a permeability modifier) is optionally added to the present foam to enhance dimensional stability. Preferred agents include C10-24 fatty acid esters and amides. Such agents are shown in US Patent Nos. 3,644,230 and 4,214,054. Esters can also reduce static capacity during and after foam making. Most preferred agents include stearyl stearamide, glycerol monostearate, glycerol monobehenate, and sorbitol monostearate. When used, such stability control agents are typically employed in an amount ranging from> 0 to 10 parts per hundred parts of the polymer.
The foams of the present invention can be used in any application where foams of comparable open or closed cell density and content are used today. Such applications include, but are not limited to, shock-absorbing packaging (eg, corner blocks, clamps, zip ties, flexible bags, bags, wrappers, covers, interlinking, encapsulation) of finished electronic products such as computers, televisions, and kitchen utensils; packaging or protection of explosive materials or devices; handling (trays, handling boxes, box supplements, handling box inserts, and dividers, conduits, fillers, plates, and part dividers); workstation accessories (aprons, table and bench covers, rugs, cushions); automotive (headliner, shock absorption on bumpers or doors, carpet underlays, sound insulation); flotation (for example, life jackets, vests and belts); sports and leisure or athletic and recreational products (eg gym mats and surfboards); egg cartons, meat trays, fruit trays, thermal insulation (such as used in building and construction for wall coverings, roofing,
ES 2 295 337 T3 insulation of foundations and insulation material under floors); sound insulation (eg for building and construction applications); pipe insulation, insulation for refrigeration, buoyancy applications (e.g. floating docks and rafts), floral and craft products, pallets, luggage liners, desk pads, footwear (including shoe soles), insulation blankets for greenhouses , case inserts, visor foams, gaskets, grommets, seals; sound attenuation for printers and typewriters; monitor housings padding; missile container filling; holds military sheaths; blocking and reinforcement of various items in transport; conservation and packaging; anti-vibration pads for the automotive industry; seals; medical devices, skin contact pads; padded pallets; and vibration isolation pads. The above list only illustrates a number of suitable applications. Those skilled in the art can easily imagine additional applications.
In another aspect, the polymeric compositions of this invention can be used to make foamed films. The film of the present invention can be a monolayer or a multilayer film. One or more layers of the film can be oriented or foamed. A multilayer film of the present invention may contain one, two, or more layers comprising a blend as defined herein. In one embodiment, the film according to the invention has a thickness of 12.7 to 2540 µm (0.5 to 100 mils). Preferably, the present invention relates to a hard and rigid film, comprising the blends of this invention. The film of the invention can be printed. The film of the invention can be obtained according to methods known in the art. The film can be prepared using a blown or cast film extrusion process, including co-extrusion and extrusion coating. One or more layers of the film can be expanded, for example with a conventional blowing agent, to prepare a foamed film. One or more films can be laminated to form a multilayer structure. Two-layer or three-layer films are preferred with one or two surface layers and the foamed layer being the <center layer. The surface layers may or may not comprise the blends of this invention. In a three-layer structure, preferably, the foamed layer is the middle or middle layer. The films can be (additionally) oriented after formation by a clothesline frame, double bubble or other blown film techniques.
Foamed film is especially suitable for use as a label or in thermoformable articles of manufacture. To obtain foamed film structures, physical or chemical blowing agents can be used. A multilayer film of the invention comprising one or more foamed layers comprising the polymeric compositions as defined herein, can be obtained according to methods known in the art, for example, using a co-extrusion process.
The label film can be constructed from rolls of printed film, slotted in width, with the labels glued to a container, for example a bottle, using conventional adhesives or glues known in the industry.In addition, the sheets of this invention can be printed, coated with pressure sensitive adhesives, laminated to peel off papers or films and apply them to bottles, containers or other surfaces by conventional pressure sensitive techniques. The bottle can be a glass bottle or a PET bottle. By covering or affixing a glass bottle, the label can also serve a protective purpose. If the bottle is a PET bottle, the preferred label is a wrap-around label.
The above list only illustrates a number of suitable applications.
The following examples are illustrative of the invention, but should not be construed as limiting its scope in any way.
Examples
Mix components used in these studies
HDPE 05862N is a high density polyethylene (a product of The Dow Chemical Company) that has a nominal melt index (I2) of 5 g / 10 min and a nominal density of 0.9625 g / cm<sup>3</sup>.
HDPE 10462N is a high density polyethylene (a product of The Dow Chemical Company) that has a nominal melt index (I2) of 10 g / 10 min and a nominal density of 0.9625 g / cm<sup>3</sup>.
AFFINITY ™ SM1300 (a product and trademark of The Dow Chemical Company) has a nominal melt index (I2) of 30 g / 10 min and a nominal density of 0.9020 g / cm<sup>3</sup>.
AFFINITY ™ PL1280 (a product and trademark of The Dow Chemical Company) has a nominal melt index (I2) of 6 g / 10 min and a nominal density of 0.9000 g / cm<sup>3</sup>.
DSV 10305.00 is a high density polyethylene (a product of The Dow Chemical Company) that has a nominal melt index (I2) of 1.1 g / 10 min and a nominal density of 0.9570 g / cm<sup>3</sup>.
LDPE 662i is a low density polyethylene (a product of The Dow Chemical Company) that has a nominal melt index (I2) of 0.5 g / 10 min and a nominal density of 0.9190 g / cm<sup>3</sup>.
ES 2 295 337 T3
LDPE 620i is a low density polyethylene (a product of The Dow Chemical Company) that has a nominal melt index (I2) of 1.8 g / 10 min and a nominal density of 0.9239 g / cm<sup>3</sup>.
LDPE 722 (a product of The Dow Chemical Company) has a nominal melt index (I2) of 8 g / 10 min and a nominal density of 0.9180 g / cm<sup>3</sup>.
LDPE 4012 (a product of The Dow Chemical Company) has a nominal melt index (I2) of 12 g / 10 min and a nominal density of 0.9180 g / cm<sup>3</sup>.
Examples 1-10 and Comparative Examples 1-6
Blends of high density polyethylene (HDPE) and low density polyethylene (LDPE) were dry blended and subsequently compounded in a Leistreitz 18mm twin screw extruder with L / D = 30 at 200 rpm. The polymers used were HDPE 05862N, HDPE 10462N and DSV 10305.00 and LDPE 662i. Example 1 also contained 0.4 weight percent mineral oil. The other examples and comparative examples did not contain mineral oil. The temperature settings were: Zone 1 -130 ° C; zone 2 -170 ° C; zone 3 -190 ° C; zone 4 -190 ° C; zone 5 -190 ° C; nozzle -190 ° C. Melt temperatures ranged from 205 ° C to 211 ° C. The data is presented in Table 1. The Comparative Examples were the individual polymers, or mixtures thereof, that were extruded at the same process settings, but did not meet the criteria of the inventive examples.
The measured melt strength of the blends of the present invention was considerably higher than predicted from a linear relationship. Melt strength ranged from 3.2 cN to 33.0 cN over a wide range of melt indices (0.46 dg / min to 4.92 dg / min). These ranges of melt strength and melt index are suitable for preparing various foams (different densities, different shapes and geometries, cross-linked, non-cross-linked, etc.). The melt strength of the inventive blends was higher than that of HDPE of similar melt index (Comparative Example 1 vs. Example 1; Comparative Example 3 vs. Examples 6-8). The inventive blend of Example 10 exhibited similar melt strength to LDPE 662i (Comparative Example 4), but the blend's melt index was higher and its flexural modulus was significantly higher. The flexural modulus of the inventive blends was greater than 700 MPa (100,000 psi), and even as high as that of HDPE (Comparative Examples 1-3 vs. Examples 1-3). The upper service temperature of the inventive blends was greater than 120 ° C.
Examples 11-14 and Comparative Examples 7-8
Mixtures of HDPE 05862N and LDPE 620i were dry blended and subsequently compounded in a Leistreitz 18mm twin screw extruder with L / D = 30 at 200 rpm. The temperature settings were: Zone 1 -130 ° C; zone 2 -170 ° C; zone 3 -190 ° C; zone 4 -190 ° C; zone 5 -190 ° C; nozzle -190 ° C. Melt temperatures ranged from 204 ° C to 211 ° C. The data are presented in Table 2. The Comparative Examples were the blends that did not meet the flexural modulus criteria of the inventive examples.
Examples 15-18 and Comparative Examples 9-18
Blends of AFFINITY ™ SM1300 and various grades of LDPE were dry blended and subsequently compounded in a Leistreitz 18mm twin screw extruder with L / D = 30 at 100 rpm. The temperature settings were: Zone 1 -185 ° C; zone 2 -185 ° C; zone 3 -185 ° C; zone 4 -185 ° C; zone 5 -185 ° C; nozzle -185 ° C. The data is presented in Table 3. Comparative Examples were the blends that did not meet one or more of the criteria of the inventive examples.
Examples 19-33
AFFINITY ™ PL 1280 and various LDPE grades were dry mixed and subsequently compounded in a Leistreitz 18mm twin screw extruder with L / D = 30 at 100 rpm. The temperature settings were: Zone 1 -185 ° C; zone 2 -185 ° C; zone 3 -185 ° C; zone 4 -185 ° C; zone 5 -185 ° C; nozzle -185 ° C. The data are presented in Table 4.
ES 2 295 337 T3
TABLE 1 - HDPE, LDPE AND MIXTURES INCLUDING LDPE 6621
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ES 2 295 337 T3
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<td>W</td><td> 3</td><td>Ό</td><td>Q.</td><td>OR</td>
<td>'iñ</td><td> *“</td><td> 2</td><td> (0</td><td>AND</td>
<td>s.</td><td></td><td>α</td><td></td><td></td>
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Table 2 - Mixtures of HDPE 05862N / LDPE 6201
ES 2 295 337 T3
<img file="ES2295337T3_D0003.tif" />
Table 3 - AFFINITY Mixes<sup>11</sup> SM1300 with LDPE
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<td>E θ</td><td>CO</td><td rowspan="2"> 3,6</td><td>IT</td><td></td><td> 0</td><td> 0_</td><td></td><td> -</td><td>CO</td><td>CO</td><td>N</td><td>CN</td><td> 0</td><td> 03</td>
<td></td><td rowspan="2">or CM</td><td>CN</td><td>CM</td><td>b- 'CM</td><td>0 CM</td><td> 0</td><td>CM</td><td></td><td> 0</td><td> 0</td><td> ®</td><td></td><td> 0</td>
<td>or</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td>S</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td>Φ</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td>• D</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td rowspan="2">Or yes? gm</td><td> 0</td><td>IT</td><td>OR</td><td>OR</td><td>OR</td><td>OR</td><td>or</td><td>OR</td><td> 10</td><td> 0</td><td>OR</td><td>OR</td><td>OR</td><td>OR</td>
<td></td><td>b-</td><td>a></td><td></td><td></td><td>CM</td><td>IT</td><td>CD</td><td>b-</td><td>co</td><td> «·</td><td> 0</td><td>CN</td><td> 0</td>
<td>α</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td>c</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td>φ</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td>φ</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td rowspan="2">δ</td><td rowspan="2">δ</td><td></td><td></td>
<td></td><td>or</td><td>or</td><td>δ</td><td>CÑ</td><td>CN</td><td>CM</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td>
<td></td><td>CM</td><td>CM</td><td>CN</td><td> 0</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td> 0</td><td> 0</td>
<td>ε</td><td> 0</td><td>CO</td><td> <0</td><td> 0</td><td>b-</td><td>b-</td><td>b-</td><td>b *</td><td>b-</td><td>b-</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td>
<td> 2 <sup>m</sup></td><td>UJ</td><td>UJ</td><td>LU</td><td>UJ</td><td>LU</td><td>UJ</td><td>UJ</td><td>UJ</td><td>UJ</td><td>UJ</td><td>LU</td><td>UJ</td><td>UJ</td><td>LU</td>
<td>CL</td><td>CL</td><td>CL</td><td>Q.</td><td>or.</td><td>CL</td><td> 0.</td><td>CL</td><td>Ql</td><td>OR.</td><td>Q.</td><td> 0.</td><td>£ L</td><td> □_</td><td>CL</td>
<td>AND</td><td>OR</td><td>Q</td><td> 0</td><td>or</td><td> 0</td><td> 0</td><td>or</td><td> 0</td><td> 0</td><td> 0</td><td>or</td><td> 0</td><td> 0</td><td> 0</td>
<td>OR</td><td>-J</td><td>_J</td><td>—J</td><td>-J</td><td> -1</td><td> —1</td><td> —1</td><td>_J</td><td> —1</td><td>—J</td><td> —1</td><td> _1</td><td>—J</td><td>_J</td>
<td>or</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td>Φ</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td>or</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td>or</td><td> 0</td><td> 40</td><td>OR</td><td>or</td><td>or</td><td>or</td><td>or</td><td>OR</td><td> 10</td><td> 0</td><td>or</td><td>or</td><td>or</td><td>or</td>
<td>Φ</td><td>CO</td><td>b-</td><td></td><td>CD</td><td>OR)</td><td>co</td><td>IT</td><td>Ν '</td><td>CN</td><td></td><td>b-</td><td> 0</td><td> 0</td><td> 0</td>
<td>£ X</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td>C</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td>Φ</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td> <</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td>
<td>Φ</td><td>CO</td><td>CO</td><td>co</td><td>co</td><td>ω</td><td>ω</td><td>ω</td><td>ω</td><td>ω</td><td>to</td><td>to</td><td>CO</td><td>CO</td><td>ω</td>
<td>c Φ</td><td>zto</td><td>2 ζ or</td><td>? or</td><td>2 Ñ. or</td><td>to</td><td>2 C or</td><td>2 ζ, P</td><td>2 or</td><td>2 C or</td><td>to</td><td>5th</td><td>to</td><td>t °</td><td>2 V. °</td>
<td>c</td><td>c</td><td></td><td>rc</td><td>rc</td><td>rc</td><td>rc</td><td>rc</td><td>rc</td><td>rc</td><td>rc</td><td>Γ C</td><td>rc</td><td>cP</td><td>l9</td>
<td>or</td><td>h- cr</td><td>I- co</td><td>r- ce</td><td>r- co</td><td>r- co</td><td>t <*></td><td>H in</td><td>* - m</td><td>1— in</td><td>r in</td><td>t— in</td><td>i— CO</td><td>r- <n</td><td>lZ 0</td>
<td>Q.</td><td>Z</td><td>z</td><td>z</td><td>Z</td><td>Z</td><td>Z "</td><td>Z</td><td>Z</td><td>Z</td><td>Z '</td><td>Z * "</td><td>z</td><td>Z</td><td>z</td>
<td>AND</td><td>or_</td><td>or.</td><td>LU</td><td>or.</td><td>OR_</td><td>LL</td><td>LL</td><td>or_</td><td>LL</td><td>or_</td><td>or.</td><td>or_</td><td>LL</td><td>LL</td>
<td>or</td><td>LU</td><td>LU</td><td>OR_</td><td>LU</td><td>LL</td><td>LL</td><td>LL</td><td>or_</td><td>OR_</td><td>or.</td><td>or_</td><td>LL</td><td>LL</td><td>OR.</td>
<td>or</td><td> <</td><td> <</td><td> <</td><td> <</td><td> <</td><td> <</td><td> <</td><td> <</td><td> <</td><td> <</td><td> <</td><td> <</td><td> <.</td><td> <</td>
<td></td><td rowspan="2">CD</td><td>or</td><td></td><td>CN</td><td>co</td><td>Ν '</td><td>IT</td><td>CD</td><td>b-</td><td>co</td><td></td><td></td><td></td><td></td>
<td></td><td>V-</td><td></td><td></td><td></td><td>T-</td><td>•and-</td><td></td><td>V—</td><td></td><td></td><td></td><td></td><td></td>
<td></td><td>CL</td><td>CL</td><td>CL</td><td>CL</td><td>CL</td><td>CL</td><td>CL</td><td>CL</td><td>CL</td><td>CL</td><td> 0</td><td> 0</td><td>b-</td><td> 0</td>
<td></td><td>AND</td><td>F</td><td>F</td><td>AND</td><td>F</td><td>F</td><td>F</td><td>F</td><td>F</td><td>F</td><td></td><td>τ-</td><td></td><td></td>
<td></td><td></td><td>or</td><td>or</td><td>OR</td><td>or</td><td>or</td><td>OR</td><td>OR</td><td>OR</td><td>OR</td><td rowspan="2">ixT</td><td></td><td></td><td rowspan="2">uT</td>
<td></td><td>OR</td><td>or</td><td>OR</td><td>or</td><td>OR</td><td>OR</td><td>Q</td><td>or</td><td>or</td><td>ω</td><td>UJ</td><td>UJ</td>
<td></td><td>llT</td><td>llT</td><td>L ± T</td><td>LU</td><td>iu</td><td>iu</td><td>iu</td><td>iu</td><td>iu</td><td>LU</td><td></td><td></td><td></td><td></td>
ES 2 295 337 T3
<img file="ES2295337T3_D0004.tif" />
Table 4 - AFFINITY Mixes<sup>tm</sup> PL1280 with LDPE
<td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td>(D</td><td>b-</td><td>CO</td><td>CN</td><td>CD</td><td>co</td><td>CD</td><td>b-</td><td>OR</td><td>CD</td><td>(D</td><td>b-</td><td>co</td><td>CN</td><td> 00</td>
<td>OR</td><td>CO</td><td>CD</td><td>CN</td><td>CN</td><td>CN</td><td>OR</td><td>CO</td><td>b-</td><td>CO</td><td>OR</td><td>CD</td><td>CD</td><td>CN</td><td>CN</td>
<td>CO</td><td>Ν '</td><td>CN</td><td>b-</td><td>(OR</td><td>r-</td><td>CO</td><td rowspan="2"> 3</td><td>CO</td><td></td><td>CD</td><td>Ν '</td><td>CN</td><td>b-</td><td>b-</td>
<td></td><td>OR)</td><td>CD</td><td>CN</td><td>ID</td><td>CD</td><td>xf</td><td>CD</td><td>CO</td><td></td><td>ID</td><td>(OR</td><td>CN</td><td>σ></td>
<td></td><td></td><td></td><td>CN</td><td>CN</td><td>CN</td><td></td><td></td><td></td><td>CN</td><td></td><td></td><td></td><td>CN</td><td>CN</td>
<td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td>co</td><td>co</td><td>CD</td><td>T—</td><td>CO</td><td>v—</td><td>CO</td><td>co</td><td>co</td><td>OR</td><td>CO</td><td>CO</td><td>CD</td><td></td><td></td>
<td>CN</td><td>co</td><td>co</td><td>σ></td><td>b- '</td><td>co</td><td>CN</td><td>CO</td><td>x /</td><td>CN</td><td>CN</td><td>co</td><td>CO</td><td>σ></td><td>co'</td>
<td>OR</td><td>or</td><td></td><td>ID</td><td>b-</td><td>OR</td><td>OR</td><td>OR</td><td></td><td>CO</td><td>OR</td><td>OR</td><td></td><td>ID</td><td>or</td>
<td></td><td></td><td></td><td></td><td></td><td>CN</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>CN</td>
<td>go</td><td>ID</td><td>OR</td><td>LD</td><td>or</td><td>ID</td><td><D</td><td>r></td><td>OR</td><td>OR</td><td>ID</td><td>r></td><td>OR</td><td>co</td><td>OR</td>
<td>xT</td><td></td><td></td><td>σ></td><td>ID</td><td>(OR</td><td>(OR</td><td>co</td><td>OR</td><td>CO</td><td>r></td><td>or</td><td>CO</td><td>or</td><td> 00</td>
<td>CO</td><td>co</td><td>CO</td><td>co</td><td>CO</td><td>CO</td><td>CN</td><td>co</td><td>co</td><td></td><td>co</td><td>co</td><td>CN</td><td>CN</td><td>co</td>
<td>or</td><td></td><td rowspan="2">s</td><td>CN</td><td>CN</td><td>CO</td><td>xt</td><td>xt</td><td>xj</td><td>CN</td><td>CN</td><td>b-</td><td>CO</td><td>CO</td><td>b-</td>
<td>or</td><td>CO</td><td>CO</td><td>ID</td><td>xf</td><td>x "</td><td>CN</td><td>r-</td><td> ·»—</td><td>CD</td><td>co</td><td>ID</td><td>xr</td><td>co</td>
<td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
<td>CN</td><td>co</td><td>Ν '</td><td>CN</td><td>CD</td><td>CO</td><td>b-</td><td>OR</td><td>χτ</td><td>b-</td><td>co</td><td>ID</td><td>b-</td><td>co</td><td>CO</td>
<td></td><td></td><td></td><td>CN</td><td>CN</td><td>CN</td><td>co'</td><td>LD</td><td>co</td><td>x?<sup>7</sup></td><td></td><td></td><td></td><td>CN</td><td>co</td>
<td>xf</td><td>or</td><td>b-</td><td>CN</td><td>CO</td><td> 00</td><td>CN</td><td>CN</td><td>co</td><td>Xf</td><td></td><td>ID</td><td>CO</td><td>or</td><td>CN</td>
<td>CN</td><td>co</td><td>CO</td><td>co</td><td>CO</td><td>CD</td><td>x?<sup>7</sup></td><td>co</td><td>b-</td><td>co'</td><td>CN</td><td>CN</td><td>CN</td><td>Xj<sup>7</sup></td><td>go</td>
<td>CO</td><td>xf</td><td>b-</td><td>CO</td><td></td><td>ID</td><td>CN</td><td>OR</td><td>CD</td><td>xf</td><td>xt</td><td>OR</td><td>OO</td><td>xt</td><td>co</td>
<td>m</td><td>CN</td><td>x<sup>-</sup></td><td>(OR</td><td>CO</td><td>CO</td><td>OR</td><td>iD</td><td>CN</td><td>xT</td><td>CD</td><td> 00</td><td>0O</td><td>co</td><td>CN</td>
<td>to</td><td>ID</td><td>ID</td><td>go</td><td>ID</td><td>CO</td><td>xj<sup>7</sup></td><td>co</td><td>co</td><td></td><td>ID</td><td>ID</td><td>go</td><td>CD</td><td>CD</td>
<td>or</td><td>ID</td><td>OR</td><td>or</td><td>OR</td><td>CD</td><td>OR</td><td>ID</td><td>OR</td><td>OR</td><td>OR</td><td>iD</td><td>OR</td><td>or</td><td>ID</td>
<td></td><td></td><td>CN</td><td>ID</td><td>CL></td><td>b-</td><td></td><td></td><td>CN</td><td>ID</td><td></td><td></td><td>CN</td><td>ID</td><td>b-</td>
<td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>(N</td><td>CN</td><td>CN</td><td></td><td></td><td></td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td>
<td>CN b ·.</td><td>CN b-</td><td>CN b-</td><td>CN b-</td><td>CN b-</td><td>CN b ~</td><td>CO CO</td><td>CO CO</td><td>CD CO</td><td>CO co</td><td> 401</td><td> 401</td><td> 401</td><td> 401</td><td>Or xf</td>
<td>LDPE</td><td>LDPE</td><td>LDPE</td><td>1 LDPE</td><td>LU CL Q —1</td><td>LDPE</td><td>LDPE</td><td>LDPE</td><td>LDPE</td><td>LDPE</td><td>LDPE</td><td>LDPE</td><td>LDPE</td><td>LU CL Q</td><td>LU CL Q _ |</td>
<td>OR</td><td>ID</td><td>OR</td><td>OR</td><td>or</td><td>ID</td><td>OR</td><td>ID</td><td>OR</td><td>r></td><td>r></td><td>ID</td><td>or</td><td>or</td><td>ID</td>
<td>CD</td><td>CO</td><td>CO</td><td>ID</td><td>xf</td><td>CN</td><td>or</td><td> 00</td><td>co</td><td>ID</td><td>CD</td><td> 00</td><td> 00</td><td>ID</td><td>CN</td>
<td>OR</td><td>OR</td><td>or</td><td>OR</td><td>OR</td><td>OR</td><td>or</td><td>r></td><td>or</td><td>r></td><td>or</td><td>OR</td><td>or</td><td>OR</td><td>or</td>
<td>CO</td><td>CO</td><td>CO</td><td>co</td><td>CO</td><td> 00</td><td> 00</td><td>co</td><td> 00</td><td>or></td><td>oo</td><td>CO</td><td>oo</td><td>CO</td><td>CO</td>
<td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td>
<td>x<sup>-</sup></td><td></td><td> *”</td><td></td><td></td><td></td><td>x ~</td><td></td><td></td><td>T—</td><td><r *</td><td></td><td></td><td></td><td></td>
<td>_J</td><td></td><td>_J</td><td>-J</td><td>_l</td><td>_l</td><td>_J</td><td></td><td>.. J</td><td> _|</td><td> _|</td><td>_J</td><td>_l</td><td> _|</td><td>_J</td>
<td>CL</td><td>Q_</td><td>Q_</td><td>CL</td><td> 0.</td><td>Q_</td><td>D_</td><td>CL</td><td>D_</td><td>Q_</td><td>Q_</td><td>D_</td><td> 0.</td><td>CL</td><td>Q_</td>
<td>z</td><td>s</td><td>z</td><td> 5</td><td>z</td><td>ΐ</td><td>z</td><td></td><td>z</td><td>or</td><td>z</td><td>z</td><td> 5</td><td></td><td>z</td>
<td> >-</td><td> >·</td><td> >-</td><td> >-</td><td> >-</td><td> >-</td><td> >-</td><td></td><td> >-</td><td> >-</td><td> >-</td><td> ></td><td> ></td><td> ></td><td> >·</td>
<td> 1—</td><td>k</td><td>k</td><td>k</td><td>k</td><td>k</td><td>k</td><td>k</td><td> 1-</td><td>k</td><td>k</td><td>k</td><td></td><td>I-</td><td>i-</td>
<td>z</td><td>Z</td><td>Z</td><td>Z</td><td>Z</td><td>Z</td><td>z</td><td>z</td><td>Z</td><td>z</td><td>Z</td><td>Z</td><td>z</td><td>z</td><td>z</td>
<td>LL</td><td>LL</td><td>LL</td><td>LL</td><td>LL</td><td>LL</td><td>LL</td><td>LL</td><td>LL</td><td>LL</td><td>LL</td><td>LL</td><td>LL</td><td>LL</td><td>LL</td>
<td>LL</td><td>LL</td><td>X</td><td>LL</td><td>LL</td><td>LL</td><td>OR</td><td> 11</td><td>Go,</td><td> 11</td><td> 11</td><td>LL</td><td>LL</td><td>LL</td><td>LL</td>
<td></td><td> <.</td><td> <</td><td> <</td><td> <.</td><td> <</td><td> <</td><td> <</td><td> <</td><td> <</td><td> <</td><td> <</td><td> <</td><td> <</td><td> <</td>
<td>σ></td><td>or</td><td></td><td>CN</td><td>CO</td><td>xT</td><td>ID</td><td>(OR</td><td>b.</td><td> 00</td><td>CD</td><td>or</td><td></td><td>CN</td><td>co</td>
<td></td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CN</td><td>CO</td><td>co</td><td>CO</td><td>co</td>
<td>iZT</td><td>llT</td><td>LU</td><td>LU</td><td>llT</td><td>LlT</td><td>LU</td><td>LU</td><td>iu</td><td>LU</td><td>iZT</td><td>ÜT</td><td>llT</td><td>LU</td><td>iu</td>
<td rowspan="2">V)</td><td>co</td>
<td>Ό</td>
<td>c</td><td>ω</td>
<td><D</td><td>c</td>
<td>Q</td><td> 0)</td>
<td></td><td>Q</td>
<td>II</td><td> >»</td>
<td>X</td><td>b-</td>
<td>to LU</td><td>co 'bCO</td>
<td>LU</td><td>II</td>
ES 2 295 337 T3
Examples 34-36 and Comparative Example 19
A blend of high density polyethylene (HDPE) and LDPE was melt blended in a 40mm twin screw extruder at 252 rpm and 79.4 kg / hr (175 lb / hr). The temperature profile in the extruder was: zone 2 -171 ° C; zone 3 -190 ° C; zone 4 -208 ° C; zone 5 -218 ° C; zone 6 -229 ° C; zone 7 -241 ° C; zone 8 -214 ° C; zone 9 -224 ° C; nozzle -221 ° C. The final melt temperature was 285 ° C. The final properties of the mixture are presented in Table 5. This blend composition is intermediate between the compositions of Examples 9 and 10 (Table 5).
TABLE 5
Blend of LDPE and HDPE
<td></td><td>Mix composition</td><td>12 (g / 10 min)</td><td>Density (g / cm ')</td><td>Melt tension</td><td>Fade strength</td><td>Melt extensibility (mm / s)</td><td>Flexural Modulus (MPa) ((psi))</td>
<td>Ex. 34</td><td>35 weight percent LDPE 662i 65 percent by weight HDPE DSV 10305.00</td><td> 0,51</td><td> 0,9423</td><td> 10,5</td><td> 25,4</td><td> 130</td><td> 860,9(122987)</td>
The mixture of Example 34 was subsequently foamed using an extrusion foaming process with isobutane as the blowing agent. Comparative Example 19 was a conventional foam prepared from LDPE 662i. Glycerol monostearate (GMS) was used as the permeability modifier and talc as the nucleator. The properties of the resulting foams are summarized in Table 6. NOTE: "phr" corresponds to part-percent of the resin.
TABLE 6
Foam from a mixture of LDPE and HDPE
<td></td><td>Polymer composition</td><td>Talc (phr)</td><td>GMS (phr)</td><td>Isobutane (phr)</td><td>Foam density (kg / m<sup>1</sup>) ASTM D357593 Suffix W</td><td>Open cells (percent by volume) ASTM D2856-87</td><td>3DAv Cell size (mm) (foam age 7 days)</td><td>Normalized compressive strength (psi / pcf) at 5/10/25/50/75 percent deflection ASTM D3575-93 Suffix D (foam age 28 days)</td>
<td>Ex Comp. 19</td><td>LDPE 662i</td><td> 0,5</td><td> 0,3</td><td> 12</td><td> 30,0</td><td> 71</td><td> 1,93</td><td> 0,8/2,5/3,4/4,2/10,0</td>
<td>Ex. 35</td><td>Mixture of Ex. 3. 4</td><td> 0,13</td><td> 0,3</td><td> 10</td><td> 34,0</td><td> 89</td><td> 1.12</td><td> 1,9/6,6/8,7/11,0/28,6</td>
<td>Ex. 36</td><td>Mixture of Ex. 3. 4</td><td> 0,13</td><td> 0,3</td><td> 15</td><td> 26,8</td><td> 55</td><td> 0,82</td><td> 1,7/6,0/10,8/20,0/49,5</td>
Foams of density ranging from 27 kg / m were successfully prepared<sup>3</sup> at 34 kg / m<sup>3</sup> from the mixture of Example 34. The open cells could be varied from 55 to 89 percent by volume. The cell sizes of the foams ranged from 0.8 to 1.1 mm. The Normalized Compressive Strengths (Total Compressive Strength / Density) of the foams of Example 35 and 36 were significantly higher than that of the reference foam (Comparative Example 19), even at lower foam density. These data indicate that foams prepared from the blends of this invention (Examples 34-36) exhibit significantly higher load bearing capacity relative to foams prepared from LDPE alone, at similar open cell densities and contents. . Or, the foams prepared from the blends of this invention (Examples 34-36) will have a load bearing capacity equivalent to LDPE foams, but at comparatively lower foam density.
Contents18
4 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4
22 members in 9 offices
Priority claims15
| Document | Office | Kind | Date |
|---|---|---|---|
| 20010274789P | United States of America | – | |
| 27478901 | United States of America | P | |
| 27478901 | United States of America | P | |
| 20010927908 | United States of America | – | |
| 92790801 | United States of America | A | |
| 92790801 | United States of America | A | |
| 20010332658P | United States of America | – | |
| 33265801 | United States of America | P | |
| 33265801 | United States of America | P | |
| 274789P02724959 | – | – | – |
| 332658P | – | – | – |
| 927908 | – | – | – |
| US20010274789P | – | – | – |
| US20010332658P | – | – | – |
| US20010927908 | – | – | – |
Members22
| Document | Office | Kind | |
|---|---|---|---|
| WO02072691A1 | World Intellectual Property Organization (WIPO) | A1 | |
| US2003032731A1 | United States of America | A1 | |
| US6545094B2 | United States of America | B2 | |
| US2003166782A1 | United States of America | A1 | |
| EP1373401A1 | European Patent Office (EPO) | A1 | |
| US6723793B2 | United States of America | B2 | |
| JP2004529231A | Japan | A | |
| EP1870434A2 | European Patent Office (EPO) | A2 | |
| EP1373401B1 | European Patent Office (EPO) | B1 | |
| AT382660T | Austria | T | |
| DE60224372D1 | Germany | D1 | |
| EP1870434A3 | European Patent Office (EPO) | A3 | |
| PT1373401E | Portugal | E | |
| ES2295337T3This record | Spain | T3 | |
| EP1373401B8 | European Patent Office (EPO) | B8 | |
| HK1112013A1 | Hong Kong, China | A1 | |
| DE60224372T2 | Germany | T2 | |
| JP4238032B2 | Japan | B2 | |
| EP1870434B1 | European Patent Office (EPO) | B1 | |
| AT452936T | Austria | T | |
| DE60234880D1 | Germany | D1 | |
| ES2337613T3 | Spain | T3 |
Numbers
- Publication
- 2295337
- Publication, DOCDB
- 2295337
- Publication, EPODOC
- ES2295337T
- Application
- 2724959
- Application, DOCDB
- 02724959
- Application, EPODOC
- ES20020724959T
Titles2
- Spanish
- MEZCLAS DE POLIMEROS ETILENICOS CON MODULO Y RESISTENCIA DEL FUNDIDO MEJORADOS Y ARTICULOS FABRICADOS A PARTIR DE ESTAS MEZCLAS.
- English
- MIXTURES OF ETHYLENE POLYMERS WITH IMPROVED MODULE AND RESISTANCE OF THE CAST AND ARTICLES MANUFACTURED FROM THESE MIXTURES.
Classification
- CPC, 4
- C08L23/0815
- C08L23/02
- C08L2205/02
- C08L2207/07
- IPC, 5
- C08L23 04
- C08L23 06
- C08L23 02
- C08L23 08
- C08L23 16