Nanocomposite blend composition having super barrier property

ES 2 276 971 T5

DESCRIPTION

Nanocomposite material mixture composition that has superior barrier properties.

Background of the Invention (a) Field of the Invention

The present invention relates to a nanocomposite material mixture composition that has superior barrier properties, and more particularly to a nanocomposite material mixture composition that has superior mechanical strength and superior barrier properties for oxygen, organic solvents and moisture, and which can be applied to single or multilayer blow molding, and film processing.

(b) Description of related art

Generalist resins, such as polyethylene and polypropylene, are used in many fields due to their superior moldability, mechanical properties, and moisture barrier properties. Although these resins also have good gas barrier properties, they have limited use in packaging or as containers for agrochemicals and food, requiring superior oxygen barrier properties. Therefore, the containers or containers (bottles) for this type of materials are manufactured in multilayers by coextrusion, lamination, coating, etc.

Multilayer plastic products made of ethylene-vinyl alcohol copolymer (EVOH) and polyamide are transparent and have good gas barrier properties. However, since ethylene vinyl alcohol and polyamide are more expensive than generalist resins, their contents in the products are restricted, and it is required to make the ethylene vinyl alcohol and polyamide as thin as possible.

To reduce the production costs of plastic containers, a process has been proposed for composing ethylene-vinyl alcohol and polyamide with cheap polyolefin. However, since ethylene vinyl alcohol and polyamide are not very compatible with polyolefin, mixing is not easy. If ethylene vinyl alcohol and polyamide are insufficiently mixed, the mechanical properties of the produced films or sheets are poor.

In this regard, the process of using a compatibility agent has been proposed to increase the compatibility of ethylene-vinyl alcohol and polyamide with respect to polyolefin. Since the compatibility agent increases the compatibility of ethylene-vinyl alcohol and polyamide with respect to polyolefin, the selection of a good compatibility agent is an important technical matter to improve the mechanical strength and chemical barrier properties of the products.

USP No. 4,971,864, USP No. 5,356,990, EP No. 15,556 and EP No. 210,725 disclose a method of using a compatibility agent prepared by grafting polyethylene and maleic anhydride. Although this compatibility agent increases oxygen barrier properties and mechanical strength, moisture barrier properties are poor due to the hydrophilic properties of ethylene vinyl alcohol and polyamide and ionomers. Therefore, the processing of the hydrophobic resin in the outermost layer is difficult, and there is no suitable processing condition to obtain an effective morphology of barrier properties.

As disclosed in USP Nos. 4,739,007, 4,618,528, 4,874,728, 4,889,885, 4,810,734, and 5,385,776, a nanocomposite material is an exfoliated or interleaved plate, with a tactid structure, or a mixture by dispersion of the above of nanometric dimensions, which comprises sandwiched clay dispersed in a polymer matrix, such as an oligomer, a polymer, or a mixture thereof.

In general, the technology of manufacturing nanocomposite materials is divided into two procedures.

The first process is the process of manufacturing said polyamide nanocomposite material. In this procedure, the monomers are inserted with organic clay sandwiched, and the clay plates are dispersed in the interlayer polymerization. This procedure is restrictive in that it can be applied only when cationic polymerization is possible.

The other process is the melt compounding process, which inserts molten polymer chains into the intercalated clay, and the former is exfoliated by mechanical compounding. Examples of such procedures are disclosed in Preparation of polystyrene nanocomposite (RA Vaia, et al., Chem. Mater., 5, 1694 (1993)), Preparation of polypropylene nanocomposite (M. Kawasumi, et al., Macromolecules, 30, 333 (1997)), and in Preparation of nylon 6 nanocomposite (USP No. 5,385,776), etc.

Therefore, research is needed on nanocomposite material blend compositions which have superior mechanical strength and chemical barrier properties, and which are capable of achieving effective morphology of barrier properties.

ES 2 276 971 T5

Summary of the invention

The present invention was made in consideration of the problems of the prior art, and it is an object of the present invention to provide a nanocomposite material mixture composition that has superior mechanical strength and superior barrier properties with respect to oxygen, organic solvents and moisture, and which can be applied to single or multi-layer blow molding, and film processing.

It is another object of the present invention to provide a container and a film comprising said nanocomposite material mixture composition.

To achieve these objectives, the present invention provides a nanocomposite material mixture composition having barrier properties comprising:

a) between 1 and 97% by weight of a polyolefin resin;

b) between 1 and 95% by weight of one or more nanocomposite materials that have barrier properties, selected from

i. an ethylene vinyl alcohol (EVOH) / sandwiched clay nanocomposite;

ii. a polyamide / clay sandwiched nanocomposite;

iii. a nanocomposite material of an ionomer / intercalated clay;

iv. a polyvinyl alcohol (PVA) / sandwiched clay nanocomposite; Y

c) between 1 and 95% by weight of a compatibility agent, wherein the compatibility agent is as defined in a later paragraph or the compatibility agent comprises between 1 and 80% by weight of a copolymer comprising a chain styrene and epoxy compounds and acrylic monomer branches for 100% by weight of the nanocomposite mix.

The present invention also provides a container and a film comprising such a nanocomposite blend composition.

Brief description of the drawings

Fig. 1 is a schematic diagram of the morphology of a nanocomposite material that has barrier properties in the presence of a discontinuous resin.

Fig. 2a is an electron microscope photograph (X200) of a cross section of a blow molded container comprising the nanocomposite blend composition prepared by a preferred embodiment of the present invention.

Fig. 2b is an electron microscope photograph (X 5000) of a cross section of a blow molded container comprising the nanocomposite blend composition prepared by a preferred embodiment of the present invention.

Fig. 3a is an electron microscope photograph (X 2000) of a cross section of a blow molded container comprising a blend composition that does not comprise the nanocomposite material with barrier properties of the present invention.

Fig. 3b is an electron microscope photograph (X 5000) of a cross section of a blow molded container comprising a blend composition that does not comprise the nanocomposite material with barrier properties of the present invention.

* symbols in the drawings *

10: polyolefin continuous phase

11: discontinuous phase of nanocomposite material.

Detailed description of the preferred embodiments

The present invention will be explained in more detail below.

The present inventors have worked to develop a process for improving the mechanical strength and chemical barrier properties of a mixture of nanocomposite materials. By doing this, they found that a

ES 2 276 971 T5 nanocomposite material prepared by exfoliating clay sandwiched into a resin that had barrier properties, such as ethylene-vinyl alcohol (EVOH), a polyamide, an ionomer, and poly (vinyl alcohol) (PVA), increases barrier properties against moisture and liquids by increasing the passage of gas and liquid into the resin, and suppresses parison sag during blow molding by increasing melt strength in the continuous polyolefin phase. Likewise, they found that a mixture of nanocomposite materials that comprises the nanocomposite material that has barrier properties, the polyolefin resin and the compatibility agent has superior mechanical resistance and superior barrier properties against oxygen, organic solvents, and humidity.

The nanocomposite material mixture composition of the present invention is characterized in that it comprises a polyolefin resin (a); a nanocomposite (b) having barrier properties selected from one or more of (i) an ethylene vinyl alcohol (EVOH) nanocomposite material and sandwiched clay, (ii) a polyamide / clay sandwiched nanocomposite, (iii) a nanocomposite material of an ionomer / intercalated clay; and (iv) a polyvinyl alcohol (PVA) / sandwiched clay nanocomposite; and a compatibility agent (c) wherein the compatibility agent is as defined in a later paragraph or the compatibility agent comprises between 1 and 80% by weight of a copolymer comprising a styrene backbone and epoxy compounds and branches of acrylic monomers for 100% by weight of the mixture of nanocomposite materials.

For the polyolefin resin (a), a high-density polyethylene (HDPE), a low-density polyethylene (LDPE), a linear low-density polyethylene (LLDPE), an ethylene-propylene polymer or a copolymer of ethylene-propylene.

The polyolefin resin content is preferably between 1 and 97% by weight, and more preferably between 20 and 97% of 100% by weight of the mixture of nanocomposite materials.

The sandwiched clay used in the nanocomposite (b) preferably comprises an organic sandwiched clay. The organic content of the sandwiched clay is preferably between 1 and 45% by weight.

The intercalated clay is one or more materials selected from montmorillonite, bentonite, kaolinite, mica, hectorite, fluorohectorite, saponite, beidelite, nontronite, stevensite, vermiculite, halosite, volkonskoite, suconite, magadite, and kenialite; and the organic material preferably has a functional group selected from quaternary ammonium, phosphonium, maleate, succinate, acrylate, benzyl hydrogen, and oxazoline.

The ethylene content in the ethylene vinyl alcohol (EVOH) / sandwiched clay nanocomposite (b, i) is preferably between 10 and 50% by mole. If the ethylene content is less than 10% by mole, melt molding becomes difficult due to poor processability. On the other hand, if it exceeds 50% by mole, the barrier properties against oxygen and liquids will be insufficient.

For the polyamide of the interleaved polyamide / clay nanocomposite (b, ii), nylon 4.6, nylon 6, nylon 6.6, nylon 6.10, nylon 6.12, nylon 11, nylon 12, or amorphous nylon can be used.

The ionomer of the intercalated ionomer / clay nanocomposite (b, iii) is preferably a copolymer of acrylic acid and ethylene, with a melt index between 1 and 10 10 g / 10 min (190 ° C, 2,160 g).

The content of nanocomposite material having barrier properties (b) is preferably between 1 and 95% by weight, and more preferably between 1 and 30% by weight, of 100% by weight of the mixture of nanocomposite materials. .

The nanocomposite material that has barrier properties offers favorable conditions for the discontinuous resin to reach the morphology of Fig. 1, according to the content of the intercalated clay. The more finely the intercalated clay exfoliates in the discontinuous resin (ethylene-vinyl alcohol, polyamide, ionomer, or poly (vinyl alcohol)), the better barrier properties can be obtained. This is because the exfoliated sandwiched clay forms a barrier film, and therefore improves the barrier properties and mechanical properties of the resin itself, and finally improves the barrier properties and mechanical properties of the mixture.

Accordingly, the present invention maximizes the gas and liquid barrier properties by composing the resin having barrier properties and sandwiched clay, dispersing the nano-sized sandwiched clay in the resin, and thereby maximizing the contact area. between the polymer chain and the sandwiched clay.

The compatibility agent (c) reduces the brittleness of the polyolefin resin and improves its compatibility within the nanocomposite material to form a composition with a stable structure.

For the compatibility agent, one or more compounds selected from modified epoxypolystyrene copolymer, an ethylene-ethylene anhydride-acrylic acid copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-alkyl acrylate copolymer- acrylic acid, a modified high-density polyethylene

ES 2 276 971 T5 with maleic anhydride (graft), a low-density polyethylene modified with maleic anhydride (graft), an ethylene-alkyl methacrylate-methacrylic acid copolymer, an ethylene-butyl acrylate copolymer, an ethylene copolymer -vinyl acetate, an ethylene-vinyl acetate copolymer modified with maleic anhydride (graft), and modifications thereof.

The content of the compatibility agent is preferably between 1 and 95% by weight, and more preferably between 1 and 30% by weight, of 100% by weight of the mixture of nanocomposite materials.

When using a modified epoxy-polystyrene copolymer as a compatibility agent, a copolymer comprising a backbone comprising between 70 and 99% by weight of styrene and between 1 and 30% by weight of an epoxy compound represented by the Chemical Formula 1, and branches that comprise between 1 and 80% by weight of acrylic monomers. Its content is between 1 and 80% by weight of 100% by weight of the mixture of nanocomposite materials.

[Chemical Formula 1]

-R-CH-CH-R '\ / o

In Chemical Formula 1, RyR 'are aliphatic residues C_1-20, or aromatic residues C_5-20 that have double bonds at the end.

[Chemical Formula 2]

<img file="ES2276971T5_D0001.tif" />

C = O ch₃

Maleic anhydride modified (graft) high density polyethylene, maleic anhydride modified linear low density polyethylene (graft), or maleic anhydride modified (graft) ethylene copolymer vinyl acetate preferably comprise branches having between 0 , 1 and 10% by weight of maleic anhydride per 100% by weight of the main chain.

The nanocomposite material blend composition of the present invention can be applied to the manufacture of blow molded products, monolayer products, and multilayer products. Likewise, they can be manufactured in the form of containers (bottles) and films by blow molding, extrusion molding, injection molding, or thermoforming.

The manufacturing procedures are as follows.

Manufacturing by unique procedure

In blow molding and injection molding to produce finished products, the nanocomposite material having barrier properties (b) is dispersed in the matrix resin (a: polyolefin resin) at the same time using a single screw extruder, a parallel rotating twin screw extruder, a counter rotating twin screw extruder, a continuous compounding machine, an orbital type extruder, etc.

Manufacturing by multiple process

The nanocomposite material having barrier properties (b) is prepared using a polymer compounding machine such as a single screw extruder, a parallel rotating twin screw extruder, a counter rotating twin screw extruder, a continuous compounding machine, an extruder orbital type, a batch composer, etc. Next, the nanocomposite is mixed with the matrix resin (a: polyolefin resin) to obtain the finished products.

For the manufacturing process, blow molding, extrusion molding, injection molding, and thermoforming can be used. However, the present invention is not limited to such processes, and includes all processing processes for the manufacture of containers having barrier properties.

ES 2 276 971 T5

Hereinafter, the present invention is disclosed in more detail by way of examples. However, the following examples are solely for the understanding of the present invention, and the present invention is not limited to the following examples.

Examples

Example 1

Preparation of nanocomposite material that has barrier properties

15% by weight of an ethylene-vinyl alcohol copolymer (EVOH; E-105B (ethylene content: 44% by mole); Kuraray, Japan; melt index: 5.5 g / 10 min; density: 1.14 g / cm³) and 13.3% by weight of high density polyethylene modified with maleic anhydride (graft) (HDPE-g-MAH; Uniroyal Chemical, USA; PB3009 (MAH content: 1%); melt index: 5 g / 10 min; density: 0.95 g / cm³), as a compatibility agent, were placed in the main hopper of a twin screw extruder (ZSK 25; W&amp;P, USA). Next, 3.3% by weight of montmorillonite (Southern intercalated clay Products, USA; C2OA) that was made organic with intercalated clay was separately placed in the side feeder to prepare an ethylene-vinyl alcohol / intercalated clay nanocomposite. The extrusion temperature condition was 180-190-200-200-200-200-200 ° C, the screw speed was 300 rpm, and the discharge condition was 10 kg / h.

Preparation of the mixture of nanocomposite materials

The ethylene-vinyl alcohol / clay sandwiched nanocomposite material was dry-mixed with 68.4% by weight high-density polyethylene (BD0390; LG Chem; melt index: 0.3 g / 10 min; density: 0.949 g / cm³) and placed in a twin screw extruder. The mixture was extruded to obtain a mixture of nanocomposite materials. The extrusion temperature condition was 180-190-190-190-190-190-190-190 ° C, the screw speed was 300 rpm, and the discharge condition was 10 kg / h.

Container manufacturing

The prepared nanocomposite mixture was blow molded to make a 1,000 ml container. The processing temperature condition was 160-190-190-190-185 ° C, and the screw speed was 33 rpm.

Example 2

Preparation of the nanocomposite material that has barrier properties

15% by weight of an ethylene-vinyl alcohol copolymer and 13.3% by weight of high density polyethylene modified with maleic anhydride (graft) were placed in the main hopper of a twin screw extruder. Next, 3.3% by weight of montmorillonite that was made organic with sandwiched clay was separately placed in the side feeder to prepare an ethylene-vinyl alcohol / sandwiched clay nanocomposite. The extrusion temperature condition was 180-190-200-200-200-200-200 ° C, the screw speed was 300 rpm, and the discharge condition was 10 kg / h.

Preparation of the mixture of nanocomposite materials and the container

The ethylene vinyl alcohol / clay sandwiched nanocomposite was dry mixed with 68.4% by weight high density polyethylene and blow molded to make a 1,000 ml container. The processing temperature condition was 160-190-190-190-185 ° C, and the screw speed was 33 rpm.

Example 3

Preparation of the nanocomposite material that has barrier properties

97% by weight of polyamide (nylon 6) was placed in the main hopper of a twin screw extruder. Next, 3% by weight of montmorillonite that was made organic with sandwiched clay was separately placed on the side feeder to prepare a polyamide / clay sandwiched nanocomposite. The extrusion temperature condition was 220-230-245-245-245-245-245 ° C, the screw speed was 300 rpm, and the discharge condition was 10 kg / h.

Preparation of the mixture of nanocomposite materials and the container

15% by weight of the prepared polyamide / clay sandwiched nanocomposite was dry mixed with 7% by weight of maleic anhydride modified high density polyethylene (graft), a compatibility agent, and 68% by weight of polyethylene high density, and blow molded into a 1,000 ml container.

ES 2 276 971 T5

The processing temperature condition was 160-190-190-190-185 ° C, and the screw speed was 33 rpm. A disc-shaped structure was identified when the cross section of the blow molded container was viewed with an electron microscope (x 200; 5 x 5,000). The results are shown in Fig. 2a and Fig. 2b.

Example 4

Preparation of the nanocomposite material that has barrier properties

97% by weight of polyamide (nylon 6) was placed in the main hopper of a twin screw extruder. Next, 3% by weight of montmorillonite that was made organic with sandwiched clay was separately placed on the side feeder to prepare a polyamide / clay sandwiched nanocomposite. The extrusion temperature condition was 220-230-245-245-245-245-245 ° C, the screw speed was 300 rpm, and the discharge condition was 10 kg / h.

Preparation of the mixture of nanocomposite materials and the container

The prepared polyamide / clay sandwiched nanocomposite was dry mixed with 7% by weight of a modified epoxy-polystyrene copolymer (311x121x41; Johnson Polymer, USA), a compatibility agent, and 68% by weight of polyethylene high density, and was blow molded into a 1,000 ml container. The processing temperature condition was 160-190-190-190-185 ° C, and the screw speed was 33 rpm.

Comparative Example 1

100% by weight high density polyethylene was blow molded to make a 1000 ml container.

Comparative Example 2

The same procedure was carried out as organic with sandwiched clay.

in Example 1, except that montmorillonite made

Comparative example 3

The same procedure was carried out as organic with sandwiched clay.

in Example 2, except that montmorillonite made

Comparative Example 4

The same procedure was carried out as organic with sandwiched clay.

in Example 3, except that montmorillonite made

Comparative Example 5 in Example 3, except that montmorillonite made

The same procedure was carried out as organic with sandwiched clay. The cross section of the blow molded container was observed with an electron microscope (x 2000; 5 x 5000). The results are shown in Fig. 3a and Fig. 3b.

Comparative Example 6

Preparation of the nanocomposite material that has barrier properties

97% by weight of high density polyethylene was placed in the main hopper of a twin screw extruder. Next, 3% by weight of montmorillonite which was made organic with sandwiched clay was separately placed in the side feeder to prepare a high density polyethylene / clay sandwiched nanocomposite. The extrusion temperature condition was 175-190-190-190-190-190-190 ° C, the screw speed was 300 rpm, and the discharge condition was 10 kg / h.

Preparation of the mixture of nanocomposite materials and the container

The nanocomposite material prepared from high density polyethylene / sandwiched clay was blow molded to make a 1,000 ml container. The processing temperature condition was 160-190-190-190-185 ° C, and the screw speed was 33 rpm.

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Experimental example

For the blow molded containers made in Examples 1 and 2 and Comparative Examples 1 and 3, the gas and liquid barrier properties were determined by the following procedure. The results are shown in Table 1.

a) Liquid barrier properties: Toluene, Desys herbicide (1% deltamethrin + emulsifier, stabilizer, and solvent; Kyung Nong), were placed in the containers manufactured in Examples 1 and 2 and in Comparative Examples 1 and 3, Batsa insecticide (50% BPMC + 50% emulsifier and solvent), and water. Next, the weight variation was determined under a forced exit condition at 50 ° C.

b) Barrier properties against gases: (cm³/ m² · Day · atm). The blow molded containers in Examples 1 and 2 and Comparative Examples 1 and 3 were left alone under the condition of a temperature of 23 ° C and a relative humidity of 50% for 1 day. The gas penetration rate was then determined (Mocon OX-TRAN 2/20, USA).

TABLE 1

<td rowspan="3">Classification</td><td colspan="5">Barrier properties against liquids (%)</td><td colspan="2">Gas barrier properties: cm³/ m² day atm.</td>

<td>Weight variation a25^QC</td><td colspan="4">Weight change to 50^Q C</td><td rowspan="2">Oxygen penetration</td><td rowspan="2">CO penetration₂</td>

<td>Toluene</td><td>Toluene</td><td>Desys</td><td>Batsa</td><td>Water</td>

<td>Example 1</td><td> 1,29</td><td> 14,70</td><td> 15,24</td><td> 2,40</td><td> 0,000014</td><td> 4.105</td><td> 10.020</td>

<td>Example 2</td><td> 0,03</td><td> 0,97</td><td> 0,50</td><td> 0,03</td><td> 0,000002</td><td> 82</td><td> 167</td>

<td>Example 3</td><td> 0,02</td><td> 0,85</td><td> 0,43</td><td> 0,03</td><td> 0,000010</td><td> 454</td><td> 426</td>

<td>Example 4</td><td> 0,02</td><td> 0,88</td><td> 0,52</td><td> 0,04</td><td> 0,000014</td><td> 522</td><td> 504</td>

<td>Comparative Example 1</td><td> 3,45</td><td> 32,52</td><td> 26,61</td><td> 5,60</td><td> 0,000039</td><td> 12.312</td><td> 23.097</td>

<td>Comparative Example 2</td><td> 1,14</td><td> 12,88</td><td> 13,92</td><td> 1,64</td><td> 0,000466</td><td> 1.320</td><td> 1.824</td>

<td>Comparative Example 3</td><td> 1,70</td><td> 15,52</td><td> 16,91</td><td> 2,49</td><td> 0,000614</td><td> 1.892</td><td> 2.772</td>

<td>Example Comparative4</td><td> 1,37</td><td> 13,25</td><td> 9,36</td><td> 2,11</td><td> 0,000062</td><td> 2.929</td><td> 4.116</td>

<td>Comparative Example 5</td><td> 1,44</td><td> 15,17</td><td> 10,03</td><td> 2,43</td><td> 0,000089</td><td> 3.323</td><td> 5.287</td>

<td>Comparative Example 6</td><td> 2,96</td><td> 27,45</td><td> 21,66</td><td> 1,43</td><td> 0,000031</td><td> 11.204</td><td> 20.194</td>

As shown in Table 1, the nanocomposite material mixture compositions of Examples 1 to 4 according to the present invention, comprising a polyolefin resin; one or more nanocomposite materials having barrier properties, selected from an ethylene vinyl alcohol (EVOH) / sandwiched nanocomposite, a polyamide / sandwiched nanocomposite, an ionomer / sandwiched nanocomposite, and a nanocomposite polyvinyl alcohol (PVA) / interleaved clay; and a compatibility agent, have better barrier properties against liquids and gases than Comparative Examples 1 to 6.

ES 2 276 971 T5

As disclosed above, the nanocomposite material blend composition of the present invention has superior mechanical strength and superior barrier properties against oxygen, organic solvents, and moisture. Also, it has good chemical barrier properties, and can be applied to single or multi-layer blow molding processing and film processing.