EP0854894B1

Vinylidene chloride composition and film with high thermal stability

Abstract

This record has no abstract on file.

Term

Term ended

Expired 1 October 2016, 10 years ago.

17 claims: 17 independent, 0 dependent

1
A thermoplastic film comprising a barrier layer derived from a composition comprising:a) an extrudable vinylidene chloride polymer or copolymer;b) per 100 parts by weight of (a), at least 0.1 parts by weight of an acid acceptor selected from the group consisting of a soap of a fatty acid and a salt of weak inorganic acid;c) per 100 parts by weight of (a), between 1 and 10 parts by weight of a dienophile copolymer comprising an anhydride moiety;andd) optionally, per 100 parts by weight of (a), between 1 and 5 parts by weight of a polymeric lubricating agent. Film thermoplastique comprenant une couche barrière dérivée d'une composition comprenant : a) un polymère ou copolymère de chlorure de vinylidène extrudable ;b) pour 100 parties en poids de (a), au moins 0,1 partie en poids d'un accepteur d'acide choisi dans le groupe constitué par un savon d'un acide gras et un sel d'un acide inorganique faible ;c) pour 100 parties en poids de (a), entre 1 et 10 parties en poids d'un copolymère de diénophile comprenant un fragment anhydride ;etd) facultativement, pour 100 parties en poids de (a), entre 1 et 5 parties en poids d'un agent lubrifiant polymère. Thermoplastische Folie, die eine Sperrschicht umfasst, die sich von einer Zusammensetzung ableitet, die a) extrudierbares Vinylidenchloridpolymer oder -copolymer,b) pro 100 Gewichtsteile von (a) mindestens 0,1 Gewichtsteile Säureakzeptor ausgewählt aus der Gruppe bestehend aus Seife einer Fettsäure und Salz einer schwachen organischen Säure,c) pro 100 Gewichtsteile von (a) 1 bis 10 Gewichtsteile Dienophilcopolymer mit einem Anhydridanteil, undd) gegebenenfalls pro 100 Gewichtsteile von (a) 1 bis 5 Gewichtsteile polymeres Schmiermittel umfasst.
2
Film selon la revendication 1, dans lequel ladite composition comprend entre 1 et 10 parties en poids dudit accepteur d'acide. Folie nach Anspruch 1, bei der die Zusammensetzung 1 bis 10 Gewichtsteile des Säureakzeptors umfasst. The film of claim 1 wherein said composition comprises between 1 and 10 parts by weight of said acid acceptor.
3
Film selon la revendication 1, dans lequel ladite composition comprend entre 1 et 5 parties en poids dudit accepteur d'acide. Folie nach Anspruch 1, bei der die Zusammensetzung 1 bis 5 Gewichtsteile des Säureakzeptors umfasst. The film of claim 1 wherein said composition comprises between 1 and 5 parts by weight of said acid acceptor.
4
Film selon l'une quelconque des revendications 1 à 3, dans lequel ledit agent lubrifiant polymère comprend un terpolymère ayant un comonomère d'acrylate. Folie nach einem der Ansprüche 1 bis 3, bei der das polymere Schmiermittel ein Terpolymer mit einem Acrylatcomonomer umfasst. The film of any of claims 1 to 3 wherein said polymeric lubricating agent comprises a terpolymer having an acrylate comonomer.
5
Film selon l'une quelconque des revendications 1 à 4, dans lequel ledit savon d'un acide gras comprend le ricinoléate de calcium. Folie nach einem der Ansprüche 1 bis 4, bei der die Seife einer Fettsäure Calciumricinoleat umfasst. The film of any of claims 1 to 4 wherein said soap of a fatty acid comprises calcium ricinoleate.
6
Film selon l'une quelconque des revendications 1 à 5, dans lequel ledit sel d'un acide inorganique faible comprend le pyrophosphate tétrasodique. Folie nach einem der Ansprüche 1 bis 5, bei der das Salz einer schwachen anorganischen Säure Tetranatriumpyrophosphat umfasst. The film of any of claims 1 to 5 wherein said salt of a weak inorganic acid comprises tetrasodium pyrophosphate.
7
Film selon l'une quelconque des revendications 1 à 6, dans lequel ledit copolymère ayant un fragment anhydride comprend un terpolymère ayant des comonomères oléfiniques, acryliques et anhydrides ou un copolymère greffé d'anhydride maléique. Folie nach einem der Ansprüche 1 bis 6, bei der das Copolymer mit einem Anhydridanteil ein Terpolymer mit olefinischen, acrylischen und Anhydrid-Comonomeren oder ein gepfropftes Copolymer von Maleinsäureanhydrid umfasst. The film of any of claims 1 to 6 wherein said copolymer having an anhydride moiety comprises a terpolymer having olefinic, acrylic, and anhydride comonomers or a grafted copolymer of maleic anhydride.
8
Film selon la revendication 7, dans lequel ledit terpolymère comprend un terpolymère éthylène/acrylate d'alkyle/anhydride maléique. Folie nach Anspruch 7, bei der das Terpolymer ein Ethylen/Alkylacrylat/Maleinsäureanhydrid-Terpolymer umfasst. The film of claim 7 wherein said terpolymer comprises an ethylene/alkyl acrylate/maleic anhydride terpolymer.
9
Film selon l'une quelconque des revendications 1 à 7, comprenant en outre une couche d'étanchéité, une couche centrale et une couche d'inviolabilité. Folie nach einem der Ansprüche 1 bis 7, die ferner eine Siegelschicht, eine Kernschicht und eine Schutzschicht umfasst. The film of any of claims 1 to 7 further comprising a sealant layer, a core layer, and an abuse layer.
10
Film selon l'une quelconque des revendications 1 à 9, dans lequel ladite composition comprend entre 1 et 5 parties dudit diénophile. Folie nach einem der Ansprüche 1 bis 9, bei der die Zusammensetzung 1 bis 5 Teile des Dienophils umfasst. The film of any of claims 1 to 9 wherein said composition comprises between 1 and 5 parts of said dienophile.
11
A film comprising:a) a sealant layer;b) a first intermediate layer comprising a material selected from the group consisting of polyamide, polyester, and ethylene vinyl alcohol copolymer;c) optionally, a polymeric adhesive layer disposed between said first intermediate layer and said sealant layer;d) a barrier layer comprising vinylidene chloride copolymer, said barrier layer being derived from a composition comprising: i) an extrudable vinylidene chloride polymer or copolymer,ii) per 100 parts by weight of (i), at least 0.1 parts by weight of an acid acceptor selected from the group consisting of a soap of a fatty acid and a salt of weak inorganic acid,iii) per 100 parts by weight of (i), between 1 and 10 parts by weight of a dienophile copolymer comprising an anhydride moiety, andiv) optionally, per 100 parts by weight of (i), between 1 and 5 parts by weight of a polymeric lubricating agent;e) a second intermediate layer comprising a material selected from the group consisting of polyamide, polyester, and ethylene vinyl alcohol copolymer;andf) an abuse layer. Film comprenant : a) une couche d'étanchéité ;b) une première couche intermédiaire comprenant un matériau choisi dans le groupe constitué par le polyamide, le polyester, et un copolymère éthylène-alcool vinylique ;c) facultativement, une couche adhésive polymère placée entre ladite première couche intermédiaire et ladite couche d'étanchéité ;d) une couche barrière comprenant un copolymère de chlorure de vinylidène, ladite couche barrière étant dérivée d'une composition comprenant : i) un polymère ou copolymère de chlorure de vinylidène extrudable,ii) pour 100 parties en poids de (i), au moins 0,1 partie en poids d'un accepteur d'acide choisi dans le groupe constitué par un savon d'un acide gras et un sel d'un acide inorganique faible,iii) pour 100 parties en poids de (i), entre 1 et 10 parties en poids d'un copolymère de diénophile comprenant un fragment anhydride, etiv) facultativement, pour 100 parties en poids de (i), entre 1 et 5 parties en poids d'un agent lubrifiant polymère ;e) une seconde couche intermédiaire comprenant un matériau choisi dans le groupe constitué par le polyamide, le polyester, et un copolymère éthylène-alcool vinylique ;etf) une couche d'inviolabilité. Folie, die a) eine Siegelschicht,b) eine erste Zwischenschicht, die ein Material ausgewählt aus der Gruppe bestehend aus Polyamid, Polyester und Ethylen/Vinylalkohol-Copolymer umfasst,c) gegebenenfalls eine polymere Klebeschicht, die zwischen der ersten Zwischenschicht und der Siegelschicht angeordnet ist,d) eine Sperrschicht, die Vinylidenchlorid-Copolymer umfasst, wobei die Sperrschicht sich von einer Zusammensetzung ableitet, die i) extrudierbares Vinylidenchloridpolymer oder - copolymer,ii) pro 100 Gewichtsteile von (i) mindestens 0,1 Gewichtsteile Säureakzeptor ausgewählt aus der Gruppe bestehend aus Seife einer Fettsäure und Salz einer schwachen anorganischen Säure,iii) pro 100 Gewichtsteile von (i) 1 bis 10 Gewichtsteile eines Dienophilcopolymers mit einem Anhydridanteil, undiv) gegebenenfalls pro 100 Gewichtsteile von (i) 1 bis 5 Gewichtsteile eines polymeren Schmiermittels umfasst,e) eine zweite Zwischenschicht, die ein Material ausgewählt aus der Gruppe bestehend aus Polyamid, Polyester und Ethylen/Vinylalkohol-Copolymer umfasst, undf) eine Schutzschicht umfasst.
12
Film selon la revendication 11, dans lequel ladite composition comprend entre 1 et 10 parties en poids dudit accepteur d'acide. Folie nach Anspruch 11, bei der die Zusammensetzung 1 bis 10 Gewichtsteile des Säureakzeptors umfasst. The film of claim 11 wherein said composition comprises between 1 and 10 parts by weight of said acid acceptor.
13
Film selon la revendication 11, dans lequel ledit copolymère comprenant un fragment anhydride comprend un terpolymère ayant des comonomères oléfiniques, acryliques et anhydrides ou un copolymère greffé d'anhydride maléique. Folie nach Anspruch 11, bei der das Copolymer mit einem Anhydridanteil ein Terpolymer mit olefinischen, acrylischen und Anhydrid-Comonomeren oder ein gepfropftes Copolymer von Maleinsäureanhydrid umfasst. The film of claim 11 wherein said copolymer comprising an anhydride moiety comprises a terpolymer having olefinic, acrylic, and anhydride comonomers or a grafted copolymer of maleic anhydride.
14
Film selon la revendication 13, dans lequel ledit terpolymère comprend un terpolymère éthylène/acrylate d'alkyle/anhydride maléique. Folie nach Anspruch 13, bei der das Terpolymer ein Ethylen/Alkylacrylat/Maleinsäureanhydrid-Terpolymer umfasst. The film of claim 13 wherein said terpolymer comprises an ethylene/alkyl acrylate/maleic anhydride terpolymer.
15
A package comprising:a) a food article, andb) a bag containing said food article, said bag being made from a thermoplastic film comprising a barrier layer derived from a composition comprising: i) an extrudable vinylidene chloride polymer or copolymer;ii) per 100 parts by weight of (i), at least 0.1 parts by weight of an acid acceptor selected from the group consisting of a soap of a fatty acid and a salt of weak inorganic acid;iii) per 100 parts by weight of (i), between 1 and 10 parts by weight of a dienophile copolymer comprising an anhydride moiety;andiv) optionally, per 100 parts by weight of (i), between 1 and 5 parts by weight of a polymeric lubricating agent. Emballage comprenant : a) un article alimentaire, etb) un sac contenant ledit article alimentaire, ledit sac étant fabriqué à partir d'un film thermoplastique comprenant une couche barrière dérivée d'une composition comprenant : i) un polymère ou copolymère de chlorure de vinylidène extrudable ;ii) pour 100 parties en poids de (i), au moins 0,1 partie en poids d'un accepteur d'acide choisi dans le groupe constitué par un savon d'un acide gras et un sel d'un acide inorganique faible ;iii) pour 100 parties en poids de (i), entre 1 et 10 parties en poids d'un copolymère de diénophile comprenant un fragment anhydride ;etiv) facultativement, pour 100 parties en poids de (i), entre 1 et 5 parties en poids d'un agent lubrifiant polymère. Verpackung, die a) einen Lebensmittelgegenstand undb) einen Beutel umfasst, der den Lebensmittelgegenstand enthält, wobei der Beutel aus einer thermoplastischen Folie hergestellt ist, der eine Sperrschicht umfasst, die sich von einer Zusammensetzung ableitet, die i) extrudierbares Vinylidenchloridpolymer oder - copolymer,ii) pro 100 Gewichtsteile von (i) mindestens 0,1 Gewichtsteile Säureakzeptor ausgewählt aus der Gruppe bestehend aus Seife einer Fettsäure und Salz einer schwachen anorganischer Säure,iii) pro 100 Gewichtsteile von (i) 1 bis 10 Gewichtsteile eines Dienophilcopolymers mit einem Anhydridanteil, undiv) gegebenenfalls pro 100 Gewichtsteile von (i) 1 bis 5 Gewichtsteile polymeres Schmiermittel umfasst.
16
Emballage selon la revendication 15, dans lequel l'article alimentaire est un élément choisi dans le groupe constitué par la viande rouge fraîche, le porc frais, la viande transformée, et la viande fumée. The package of claim 15 wherein the food article is a member selected from the group consisting of fresh red meat, fresh pork, processed meat, and smoked meat. Verpackung nach Anspruch 15, bei der der Lebensmittelgegenstand ein Mitglied ausgewählt aus der Gruppe bestehend aus frischem rotem Fleisch, frischem Schwein, verarbeitetem Fleisch und geräuchertem Fleisch ist.
17
Emballage selon la revendication 15, dans lequel ledit copolymère comprenant un fragment anhydride comprend un terpolymère ayant des comonomères oléfiniques, acryliques et anhydrides ou un copolymère greffé d'anhydride maléique. The package of claim 15 wherein said copolymer comprising an anhydride moiety comprises a terpolymer having olefinic, acrylic, and anhydride comonomers or a grafted copolymer of maleic anhydride. Verpackung nach Anspruch 15, bei der das Copolymer mit einem Anhydridanteil ein Terpolymer mit olefinischen, acrylischen und Anhydrid-Comonomeren oder ein gepfropftes Copolymer von Maleinsäureanhydrid umfasst.

Independent claims17

40 paragraphs in 4 sections, as filed

The present invention relates to a film made from vinylidene chloride polymers or copolymers; more particularly to a film with enhanced thermal stability and oxygen barrier properties for monolayer and multilayer packaging films having a formulated layer of vinylidene chloride copolymer.

Thermoplastic packaging films made of vinylidene chloride copolymer, typically with methyl acrylate or vinyl chloride comonomers, and here referred to as "saran", have long been used to package food such as cheese, fresh meat, etc. Saran is a good barrier to the transmission of oxygen.

Methods of producing a multilayer film having a layer of saran are disclosed in USP 4,112,181 (Baird) and USP 3,741,253 (Brax et al), both incorporated herein by reference.

Saran degrades during conventional extrusion operations, producing to some extent hydrogen chloride and conjugated polyenes.

The sequence includes a first reaction in which vinylidene chloride polymer, (CH2CCl2)n, under heat and shear conditions (typical in extrusion operations) reacts to form (CH=CCl)n + nHCl. This is of course undesirable, since HCl is corrosive, and accelerates the same reaction resulting in even more HCl generation.

A second reaction involves the reaction of (CH=CCl)n under continued heat and shear conditions, to produce conjugated polyene networks and additional HCl. This is also undesirable, because networks form gels, and gels lead to product defects in the form of pinholes.

Still further reaction results in the undesirable production of carbon.

It would be beneficial to provide film derived from a composition which prevents or retards the production of hydrogen chloride in the first reaction, and to retard the further degradation of the second reaction.

The present invention provides good thermal stability for saran formulations, and reduced degradation during extrusion.

The inventor has found that an acid acceptor such as tetrasodium pyrophosphate reacts with or accepts hydrogen chloride in the system, thereby slowing down further degradation of the vinylidene chloride polymer or copolymer. However, it has also been found that acid acceptors such as tetrasodium pyrophosphate do not disperse well in the vinylidene chloride matrix, and if used alone results in a nonuniform mixture. By also including a dienophile such as ethylene/butyl acrylate/maleic anhydride terpolymer, which acts both as a dienophile and a wetting agent, the acid acceptor is more uniformly dispersed in the vinylidene chloride matrix.

Methods for determining stability are well known, e.g. as described in USP 5,202,188 incorporated herein by reference.

SUMMARY OF THE INVENTION

In the invention, a thermoplastic film comprises a barrier layer comprising 100 parts by weight of an extrudable vinylidene chloride polymer or copolymer; at least 0.1 parts by weight of an acid acceptor selected from the group consisting of a soap of a fatty acid and a salt of a weak organic acid; and between 1 and 10 parts by weight of a dienophile.

In a third aspect, a package comprises a food article; and a bag containing the food article, the bag made from a thermoplastic film comprising a barrier layer comprising 100 parts by weight of an extrudable vinylidene chloride copolymer; at least 0.1 parts by weight of an acid acceptor; and between 1 and 10 parts by weight of a dienophile, according to claims 15-17.

DEFINITIONS

"Acid acceptor" herein means a compound that reacts with an acid such as hydrogen chloride and renders it non-reactive for further dehydrochlorination.

"Dienophile" herein means a compound that is capable of reacting with conjugated double bonds and making them nonparticipative in degradation color development associated with the degradation of vinylidene chloride polymer and copolymer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present inventive film is derived from a composition preferably comprising 100 parts by weight of an extrudable vinylidene chloride copolymer; between 1 and 10 parts by weight of the acid acceptor; and between 1 and 10 parts by weight of the dienophile. The composition can thus comprise 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 parts by weight of each of the acid acceptor and dienophile.

Optionally, the present film is derived from a composition further comprising between 1 and 5 parts by weight of a polymeric lubricating agent. The composition can thus comprise 1, 2, 3, 4, or 5 parts by weight of polymeric lubricating agent.

The acid acceptor is a soap of fatty acid, such as calcium ricinoleate, or a salt of weak inorganic acid, such as tetrasodium pyrophosphate.

The dienophile is a copolymer having an anhydride moiety. More preferred is a terpolymer having olefinic, acrylic, and anhydride comonomers, or a grafted copolymer of maleic anhydride. Most preferred is ethylene/alkyl acrylate/maleic anhydride terpolymer, such as ethylene/butyl acrylate/maleic anhydride terpolymer.

The polymeric lubricating agent can be any polymeric material which reduces the tendency of the composition to stick to metal parts during extrusion and processing, and is preferably a terpolymer having an acrylate comonomer, or calcium ricinoleate. The terpolymer preferably comprises methyl methacrylate/butyl acrylate/styrene terpolymer; methyl methacrylate/butyl acrylate/butyl methacrylate terpolymer; or blends thereof.

The composition is made into monolayer or multilayer film, oriented or unoriented, cross-linked or not cross-linked, shrinkable or not shrinkable, by means well known in the art.

In a preferred embodiment, a film comprises a four layer film structure: sealant layer/core layer/barrier layer/abuse layer where: <ul id="ul0001" list-style="none" compact="compact"><li>sealant layer = 90% ethylene vinyl acetate copolymer (EVA) (6% vinyl acetate) + 10% linear low density polyethylene (LLDPE) which is an ethylene/octene copolymer (6.5% octene);</li><li>core layer = ethylene vinyl acetate copolymer (EVA) (15% vinyl acetate);</li><li>barrier layer = (as defined in the Tables); and</li><li>abuse layer = 92.5% ethylene vinyl acetate copolymer (EVA) (9% vinyl acetate) and 7.5% linear low density polyethylene (LLDPE) which is an ethylene/octene copolymer (6.5% octene).</li></ul>

The sealant and abuse layers can comprise any suitable polymeric material, but preferably comprise an ethylene alpha olefin copolymer, an ethylene unsaturated ester copolymer, an ethylene acid copolymer, other polyolefins, or any combination or blend thereof. The core layer, which is optional, can also comprise any of these materials. Ethylene alpha olefin copolymers are preferably copolymers of ethylene with one or more comonomers selected from C3 to C10 alpha olefins. Both heterogeneous and homogeneous materials can be used. Examples of heterogeneous materials include LLDPE (linear low density polyethylene), VLDPE (very low density polyethylene), ULDPE (ultra low density polyethylene), and the like. Homogeneous materials can include metallocene catalyzed polymers (MCP) such as those available from Exxon under the EXACT trademark, and available from Dow under the AFFINITY trademark.

Ethylene unsaturated ester copolymer refers to materials such as ethylene vinyl acetate copolymer (EVA), ethylene alkyl acrylate copolymers such as ethylene ethyl acrylate copolymer (EEA), ethylene methyl acrylate copolymer (EMA), and ethylene n-butyl acrylate copolymer (EnBA). It also refers to ethylene methyl methacrylate copolymer (EMMA).

Ethylene acid copolymer refers to materials such as ethylene acrylic acid copolymer (EAA), and ethylene methacrylic acid copolymer (EMAA). Metal salt neutralized or partially neutralized versions of these materials, such as ionomer, are also included herein.

In an alternative embodiment, a film comprises a six layer film structure: <ul id="ul0002" list-style="none" compact="compact"><li>sealant layer/tie/intermediate layer/barrier layer/ intermediate layer/abuse layer where the sealant, barrier, and abuse layers are as described above for the four layer film, and: <ul id="ul0003" list-style="none" compact="compact"><li>tie layer = polymeric adhesive such as acid or acid anhydride-grafted polyolefinic adhesives, such as those sold under the trademarks Bynel, Plexar, Admer, and the like; and</li><li>intermediate layer = polyamide or copolyamide, polyester or copolyester, or ethylene vinyl alcohol copolymer, or blends of any of these materials.</li></ul></li></ul>

In another alternative embodiment, a film comprises a five layer film structure: <ul id="ul0004" list-style="none" compact="compact"><li>sealant layer/intermediate layer/barrier layer/ intermediate layer/abuse layer, where the sealant, intermediate, barrier, and abuse layers are as described above for the six layer film.</li></ul>

In the five and six layer embodiments, and for similar films with additional layers, the barrier layer can optionally comprise a vinylidene chloride copolymer without the acid acceptor and/or dienophile described above.

EXAMPLES

Table 1 identifies the compositions used in the examples.

Four films of the present invention, as well as five comparative films, were tested for O2 transmission rates. The results are shown in Table 2. Oxygen transmission were measured by ASTM 3985 using Mocon equipment.

Table 3 shows the thermal stability (shown as cross-linking time in minutes) of two additional examples, compared with two additional comparative examples.

All examples and comparative examples had the overall film structure EVA + LLDPE/EVA/Barrier/EVA+LLDPE as identified above. <tables id="tabl0001" num="0001"><table frame="all"><title>TABLE 1</title><tgroup cols="3" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="52.50mm" /><colspec colnum="2" colname="col2" colwidth="52.50mm" /><colspec colnum="3" colname="col3" colwidth="52.50mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" align="center">MATERIAL</entry><entry namest="col2" nameend="col2" align="center">TRADENAME</entry><entry namest="col3" nameend="col3" align="center">SOURCE</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="center">VDC1</entry><entry namest="col2" nameend="col2" align="center">MA134</entry><entry namest="col3" nameend="col3" align="center">DOW</entry></row><row><entry namest="col1" nameend="col1" align="center">VDC2</entry><entry namest="col2" nameend="col2" align="center">XU 32024.10</entry><entry namest="col3" nameend="col3" align="center">DOW</entry></row><row><entry namest="col1" nameend="col1" align="center">AA1</entry><entry namest="col2" nameend="col2" align="center">tetrasodium pyrophosphate</entry><entry namest="col3" nameend="col3" align="center">Monsanto</entry></row><row><entry namest="col1" nameend="col1" align="center">DP1</entry><entry namest="col2" nameend="col2" align="center">Lotader P3-3200</entry><entry namest="col3" nameend="col3" align="center">Elf Atochem</entry></row><row><entry namest="col1" nameend="col1" align="center">PLA1</entry><entry namest="col2" nameend="col2" align="center">Metablen L1000</entry><entry namest="col3" nameend="col3" align="center">ATOCHEM</entry></row><row><entry namest="col1" nameend="col1" align="center">P1</entry><entry namest="col2" nameend="col2" align="center">Plas-Chek 775</entry><entry namest="col3" nameend="col3" align="center">FERRO</entry></row><row><entry namest="col1" nameend="col1" align="center">P2</entry><entry namest="col2" nameend="col2" align="center">EPON 828</entry><entry namest="col3" nameend="col3" align="center">SHELL</entry></row><row rowsep="1"><entry namest="col1" nameend="col3" align="justify">where: VDC1 = vinylidene chloride/ methyl acrylate copolymer (8.5 mole % methyl acrylate); VDC2 = vinylidene chloride/ methyl acrylate copolymer (6.0 mole % methyl acrylate); AA1 = acid acceptor = tetrasodium pyrophosphate; DP1 = dienophile = ethylene/butyl acrylate/maleic anhydride terpolymer; PLA1 = polymeric lubricating agent = methyl methacrylate/butyl acrylate/butyl methacrylate terpolymer; P1 = epoxidized soybean oil; and P2 = diglycidyl ether of bisphenol-A.</entry></row></tbody></tgroup></table></tables>

In the tables, "phr" means 0.454 kg (pounds) per hundred (weight units) of material. For example, in comparative example 1, the equivalent of 45.4 kg (100 pounds) of saran was blended with 0.908 kg (2 pounds) of P1 and 0.908 kg (2 pounds) of PLA1. An equivalent to phr is "parts by weight". <tables id="tabl0002" num="0002"><table frame="all"><title>TABLE 2</title><tgroup cols="3" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="52.50mm" /><colspec colnum="2" colname="col2" colwidth="52.50mm" /><colspec colnum="3" colname="col3" colwidth="52.50mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" align="center">EXAMPLE</entry><entry namest="col2" nameend="col2" align="center">COMPOSITION(phr)</entry><entry namest="col3" nameend="col3" align="center">OTR(cc/0.0254 mm (mil) / day.m2.atm.)</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="center">Comparative 1</entry><entry namest="col2" nameend="col2" align="right">100 VDC1 + 2 P1 + 2 PLA1</entry><entry namest="col3" nameend="col3" align="char" char=".">3.2</entry></row><row><entry namest="col1" nameend="col1" align="center">Comparative 2</entry><entry namest="col2" nameend="col2" align="right">100 VDC1 + 4 P1 + 2 PLA1</entry><entry namest="col3" nameend="col3" align="char" char=".">6.0</entry></row><row><entry namest="col1" nameend="col1" align="center">Comparative 3</entry><entry namest="col2" nameend="col2" align="right">100 VDC1+ 2 P2 + 2 PLA1</entry><entry namest="col3" nameend="col3" align="char" char=".">2.8</entry></row><row><entry namest="col1" nameend="col1" align="center">Comparative 4</entry><entry namest="col2" nameend="col2" align="right">100 VDC1 + 4 P2+ 2 PLA1</entry><entry namest="col3" nameend="col3" align="char" char=".">2.8</entry></row><row><entry namest="col1" nameend="col1" align="center">Comparative 5</entry><entry namest="col2" nameend="col2" align="right">100 VDC1 + 2 P1 + 2 PLA1</entry><entry namest="col3" nameend="col3" align="char" char=".">3.2</entry></row><row><entry namest="col1" nameend="col1" align="center">1</entry><entry namest="col2" nameend="col2" align="right">100 VDC1 + 1 AA1 + 4 DP1 + 2 PLA1</entry><entry namest="col3" nameend="col3" align="char" char=".">2.2</entry></row><row><entry namest="col1" nameend="col1" align="center">2</entry><entry namest="col2" nameend="col2" align="right">100 VDC1 + 1 AA1 + 2 DP1 + 2 PLA1</entry><entry namest="col3" nameend="col3" align="char" char=".">2.0</entry></row><row><entry namest="col1" nameend="col1" align="center">3</entry><entry namest="col2" nameend="col2" align="right">100 VDC1 + 1 AA1 + 2 DP1</entry><entry namest="col3" nameend="col3" align="char" char=".">1.4</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="center">4</entry><entry namest="col2" nameend="col2" align="right">100 VDC2 + 1 AA1 + 2 DP1</entry><entry namest="col3" nameend="col3" align="char" char=".">1.0</entry></row></tbody></tgroup></table></tables>

Table 3 contains thermal stability data. Thermal stability was measured by taking the blend components of each example, and blending them in a torque rheometer at a mixing temperature of 179.44°C 335°F and a rotational speed of 63 rpm (for comparative example 6, and example 5) and at a mixing temperature of 185°C (365°F) and a rotational speed of 63 rpm (for comparative example 7, and example 6). Thermal stability is monitored as a function of mixing time. Changes in stability are indicated by changes in mixing torque. The crosslinking time corresponds to the maximum torque reached during the test. Crosslinking is related to molecular weight, which increases as a result of the formation of polymeric networks (an undesirable degradation effect).

Thus, the time in minutes until crosslinking occurred is censidered a measure of the thermal stability of the blended composition. Those compositions which included both an acid acceptor (tetrasodium pyrophosphate) and a dienophile (ethylene/butyl acrylate/ maleic anhydride terpolymer) showed significant improvements in thermal stability as measured by time to crosslink. <tables id="tabl0003" num="0003"><table frame="all"><title>TABLE 3</title><tgroup cols="3" colsep="1" rowsep="1"><colspec colnum="1" colname="col1" colwidth="52.50mm" /><colspec colnum="2" colname="col2" colwidth="52.50mm" /><colspec colnum="3" colname="col3" colwidth="52.50mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" align="center">EXAMPLE</entry><entry namest="col2" nameend="col2" align="center">COMPOSITION (phr)</entry><entry namest="col3" nameend="col3" align="center">CROSSLINKING TIME (minutes)</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" /></row><row><entry namest="col1" nameend="col1" align="center">Comparative 6 @ (335° F) 179.44°C</entry><entry namest="col2" nameend="col2" align="right">100 VDC1 + 1 AA1</entry><entry namest="col3" nameend="col3" align="center">17</entry></row><row><entry namest="col1" nameend="col1" /></row><row><entry namest="col1" nameend="col1" align="center">5 @ (335°F) 179.44°C</entry><entry namest="col2" nameend="col2" align="right">100 VDC1 + 1 AA1 + 2 DP1</entry><entry namest="col3" nameend="col3" align="center">31</entry></row><row><entry namest="col1" nameend="col1" /></row><row><entry namest="col1" nameend="col1" align="center">Comparative 7 @ (365°F) 185°C</entry><entry namest="col2" nameend="col2" align="right">100 VDC1 + 1 AA1</entry><entry namest="col3" nameend="col3" align="center">9</entry></row><row><entry namest="col1" nameend="col1" /></row><row rowsep="1"><entry namest="col1" nameend="col1" align="center">6 @ (365°F) 185°C</entry><entry namest="col2" nameend="col2" align="right">100 VDC1 + 1 AA1 - 2 DP1</entry><entry namest="col3" nameend="col3" align="center">24</entry></row></tbody></tgroup></table></tables>

The examples were made by a tubular extrusion coating process, well known in the art. However, other processes, such as blown film extrusion, flat cast extrusion or coextrusion, lamination, extrusion coating or extrusion lamination can be employed. These alternative processes are well known in the art.

The examples were made by irradiating a substrate (sealant and core layer) prior to extrusion coating of the barrier and abuse layers, and prior to orientation. Alternatively, films of the invention can be crosslinked by conventional means such as electronic or chemical crosslinking; post-irradiated, i.e. irradiated after orientation; or made without crosslinking, or without orientation.

Orientation is accomplished by conventional means such as blown bubble or tenterframe. Orientation ratios can be at any suitable range or ratio, including 1:1 to 6:1 in either or both of the machine and transverse direction.

Although four, five, and six layer embodiments are specifically disclosed, those in the art will readily understand that one or more layers can be made into a film having the benefits described.

"Copolymer" as used herein includes polymers with at least two dissimilar comonomers, so that terpolymers are also included.

Contents4

Every citation, both ways

Citations
Document	Relation	Office
EP0281634A	Cites	European Patent Office (EPO)
EP0402173A	Cites	European Patent Office (EPO)
EP0604137A	Cites	European Patent Office (EPO)
WO9103518A	Cites	World Intellectual Property Organization (WIPO)
US3607612A	Cites	United States of America

14 members in 9 offices

This recordMember, by publication datePriority claim

Priority claims9

Priority claims
Document	Office	Kind	Date
538755	United States of America	–	1995-10-03
53875595	United States of America	A	1995-10-03
53875595	United States of America	A	1995-10-03
9616808	United States of America	W	1996-10-01
9616808	United States of America	W	1996-10-01
538755	–	–	–
US19950538755	–	–	–
US1996016808	–	–	–
WO1996US16808	–	–	–

Members14

Family members, oldest first
Document	Office	Kind
CA2232944A1	Canada	A1	1997-04-24
WO9714554A2	World Intellectual Property Organization (WIPO)	A2	1997-04-24
AU7459796A	Australia	A	1997-05-07
WO9714554A3	World Intellectual Property Organization (WIPO)	A3	1997-09-12
US5679465A	United States of America	A	1997-10-21
EP0854894A2	European Patent Office (EPO)	A2	1998-07-29
AR003780A1	Argentina	A1	1998-09-09
AU706535B2	Australia	B2	1999-06-17
BR9611022A	Brazil	A	1999-10-05
EP0854894B1This record	European Patent Office (EPO)	B1	2005-12-21
AT313594T	Austria	T	2006-01-15
ATE313594T1	Austria	T1	2006-01-15
DE69635617D1	Germany	D1	2006-01-26
DE69635617T2	Germany	T2	2006-09-21

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2016-10-31	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2016-10-26	Patent expired after termination of 20 yearsExpiredPE20	PE20	GB
2016-02-29	Annual fee paid to national office [announced via postgrant information from national office to epo]GrantedPGFP	PGFP	EP
2016-02-29	Annual fee paid to national office [announced via postgrant information from national office to epo]GrantedPGFP	PGFP	EP
2016-01-29	Annual fee paid to national office [announced via postgrant information from national office to epo]GrantedPGFP	PGFP	EP
2015-10-19	Fee paymentPLFP	PLFP	FR
2015-07-31	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2015-05-01	Application deemed withdrawn, or ip right lapsed, due to non-payment of renewal feeWithdrawnR119	R119	DE
2014-01-31	Annual fee paid to national office [announced via postgrant information from national office to epo]GrantedPGFP	PGFP	EP
2012-10-31	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2012-08-01	Patent lapsedLapsedMM4A	MM4A	IE
2011-01-31	Annual fee paid to national office [announced via postgrant information from national office to epo]GrantedPGFP	PGFP	EP
2006-12-06	No opposition filedOpposition26N	26N	EP
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2006-06-30	Patent ceasedCeasedPL	PL	CH
2006-06-23	Fr: translation filedET	ET	EP
2006-06-01	Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents actLapsedNLV1	NLV1	EP
2006-05-22	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2006-04-01	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2006-03-21	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2006-03-21	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
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2006-01-26	Corresponds to:REF	REF	EP
2006-01-25	European patents granted designating irelandGrantedFG4D	FG4D	IE
2005-12-30	European patent takes effect as a national patent in ch/liEP	EP	CH
2005-12-21	Designated contracting statesAK	AK	EP
2005-12-21	European patent grantedGrantedFG4D	FG4D	GB
2005-12-21	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2005-12-21	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2005-12-21	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2005-12-21	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2005-12-21	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
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2005-11-04	(expected) grantORIGINAL CODE: 0009210GRAA	GRAA	EP
2005-09-03	Grant fee paidORIGINAL CODE: EPIDOSNIGR3GRAS	GRAS	EP
2005-04-23	Despatch of communication of intention to grant a patentORIGINAL CODE: EPIDOSNIGR1GRAP	GRAP	EP
1999-01-13	Party data changed (applicant data changed or rights of an application transferred)RAP1	RAP1	EP
1998-07-29	Request for examination filed17P	17P	EP
1998-07-29	Designated contracting statesAK	AK	EP
1998-06-12	Public reference made under article 153(3) epc to a published international application that has entered the european phaseORIGINAL CODE: 0009012PUAI	PUAI	EP