JP3159397B2 - Resin composition, method for producing the same, and laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a high gas barrier property for use in packaging films and containers for foods and the like, and has a processability free from pinholes, cracks, local thickness deviation, uneven drawing, etc. during a heat drawing operation. The present invention relates to a resin composition having excellent heat resistance, a method for producing the same, and a laminate including at least one layer of the composition.

[0002]

2. Description of the Related Art Conventionally, in the case of packages for foods and medicines, metal cans, glass bottles, various plastic containers, and the like have been used as packaging containers.
2. Description of the Related Art Plastic containers are used as various types of packaging containers in terms of flexibility in form, impact resistance, and cost. Among them, ethylene-vinyl alcohol (hereinafter referred to as EV)
OH) is a melt-moldable thermoplastic resin having excellent gas barrier properties, oil resistance, and fragrance retention properties as compared with other resins, and is used for packaging films in various packaging fields, particularly food packaging. It has been suitably used for molded articles such as films, sheets, containers and the like. By the way, in such EVOH, the physical properties such as the Young's modulus and impact resistance of the molded article greatly change due to environmental changes such as external humidity and temperature. However, the gas barrier property is reduced.

[0003] Remedying these drawbacks is extremely important in practice. In order to compensate for the drawback, a low water-absorbing resin such as polyethylene or polypropylene is used for EVOH.
A method of laminating on a film or sheet to reduce the hygroscopicity (JP-A-60-173038, JP-A-60-2866)
1, 62-207338) or a method of acetalizing the surface of an EVOH film or sheet to improve the moisture absorption resistance (JP-A-55-2191, 53-65378).
Alternatively, a method of improving the gas barrier property under high humidity by blending a platelet type mica with EVOH (JP-A-64-43)
554) have been proposed.

Further, a desiccant (bentonite) is melt-kneaded in EVOH to prevent deterioration of gas barrier properties after retort sterilization (US Pat. No. 4,425,410).
No.) has been proposed. Furthermore, blending an inorganic filler (such as water-non-swellable talc) with EVOH to improve the flexural modulus and thermal deformation temperature (Japanese Patent Laid-Open No. 61-2428)
41) has been proposed. See also U.S. Pat.
9229 (Japanese Patent Application Laid-Open No. 1-253442) discloses that in a multilayer structure comprising a blend layer of EVOH and polyamide and a hydrophobic thermoplastic resin layer, a filler such as calcium silicate is blended in the blend layer. However, there is no description about blending them in the presence of water.

Further, US Pat. No. 4,960,639 (JP-A-1-308627) discloses a multilayer structure comprising a blend layer of EVOH and mica and a blend layer of another thermoplastic resin and mica and the like. Although it is described that a filler is blended in the blend layer, it is not described that they are blended in the presence of water.

On the other hand, when a multilayer structure (film, sheet, parison, etc.) manufactured by various methods is subjected to secondary processing,
In particular, when heating and stretching at a temperature lower than the melting point of EVOH,
Small voids, cracks, local uneven thickness, uneven stretching, etc. occur frequently in the H layer, and as a result, the gas barrier property of the molded container is greatly reduced. In addition, the appearance was poor, and it was in a situation where it could not be used as a container for food and the like.

[0007] It is extremely important in practical use to improve the above drawbacks. In order to compensate for the drawback, a method for increasing flexibility by blending EVOH with a polyamide system to increase flexibility has been known, and a number of patents have been filed (JP-B-44-24277, JP-B-59). -38897, Tokiko 6
0-24813, JP-A-58-129,035) does not disclose the use of EVOH in which the gas barrier properties are insufficient and the water-swellable phyllosilicate is uniformly dispersed.

[0008]

However, in the above-mentioned laminating method, it is necessary to perform a laminating operation, and the obtained laminated molded body also gradually absorbs moisture, and as a result, the gas barrier property of EVOH is reduced. Decline and not an essential solution. Further, in the case of retort applications, which have been increasing in recent years, there is a problem that the gas barrier properties of EVOH are reduced due to the absorption of EVOH even in the case of laminated molded articles. Also,
As a means for acetalization, a process for acetalization is necessary after molding EVOH into a film or sheet, which is economically disadvantageous and has not been put to practical use. In addition, EVOH containing mica results in a composition having an opaque appearance, which is not preferable. Further, in any of the multilayer structures, the secondary workability is insufficient.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a resin composition comprising EVOH which does not have the above-mentioned problems and has excellent gas barrier properties even when subjected to a high humidity environment or retort sterilization. is there. Another object of the present invention is that the resin composition layer can be easily laminated with another thermoplastic resin layer and prevents pinholes, cracks, local thickness deviation, stretching unevenness, and the like. It is an object of the present invention to provide a laminate and a multilayer container which are extremely useful as materials for food packaging and the like, since they have excellent processability.

[0010]

Means for Solving the Problems The object of the present invention is to
Ethylene-vinyl alcohol copolymer (A ₁ ) having an ethylene content of 20 to 60 mol% , 0.05 to EVOH
30% by weight of a water-swellable phyllosilicate (A ₂ ) and a polyamide resin (B), and (A ₁ ) and (A ₂ )
Is 40 to 95% by weight and (B) is 60% by weight.
-5% by weight, especially for EVOH
An ethylene-vinyl alcohol copolymer (EVOH) resin composition (A) 40 containing 0.05 to 30% by weight of a water-swellable phyllosilicate and having an ethylene content of 20 to 60% by mole.
To 95% by weight and 60 to 5% by weight of polyamide resin (B)
Made, and is achieved by providing a resin composition basal spacing of a water-swellable phyllosilicate containing the EVOH resin composition satisfies the following equation (I). (X−y) ≧ 2 (I) where x is the distance between bases (angstrom) of the water-swellable phyllosilicate uniformly dispersed in EVOH in the resin composition, and y is the drying of the water-swellable phyllosilicate. It is the distance between the bottoms of the powder (angstrom).

Hereinafter, the present invention will be described specifically. EVOH used in the present invention (A ₁₎ is typically ethylene - those obtained by saponification of vinyl acetate copolymer, it is important that the ethylene content is 20 to 60 mol% And preferably 25 to 55 mol%. If the ethylene content is less than 20 mol%, water resistance,
As the moisture resistance decreases, the gas barrier property under high humidity is impaired, the stress cracking resistance decreases, and it becomes difficult to maintain good melt processing characteristics. On the other hand, if it is more than 60 mol%, the water resistance and the moisture resistance are improved, but the originally excellent gas barrier properties are deteriorated. In any case, it becomes unsuitable as a material for packaging or the like. The saponification degree of the vinyl acetate component needs to be 95 mol% or more, and preferably 98 mol%. When the saponification degree is less than 95 mol%, the thermal stability is deteriorated, a disadvantage that a gel is easily generated at the time of melt processing occurs, the gas barrier property and the oil resistance are reduced, and the original properties of EVOH cannot be maintained. It becomes difficult to enjoy the effect of.

In the present invention, as the EVOH, an ethylene content of 20 to 60 mol% and a saponification degree of a vinyl acetate component of 9 are used.
5 mol% or more and vinyl silane content of 0.0001 to
0.5 mol% silicon-containing EVOH can also be used for the purposes of the present invention. Vinyl silane is introduced by using a silicon-containing olefinically unsaturated monomer, and as the monomer, a conventionally known monomer such as that disclosed in JP-A-61-290046 can be used. For example, vinyl trimethoxy silane, vinyl methyl dimethoxy silane, vinyl triacetoxy silane, vinyl tripropionyloxy silane and the like can be mentioned. The silicon content is selected according to each purpose, but is 0.0001 to 0.5 mol%, particularly 0.001 to 0.5 mol%.
A range of 0.1 mol% is preferred.

The melt index of EVOH (value measured at a temperature of 190 ° C. under a load of 2160 g; hereinafter referred to as MI) is not particularly limited, but is 0.1 to 50 g / 1.
0 minutes. Furthermore, the EVOH referred to in the present invention may be modified with a small amount of a copolymer monomer as long as the object of the present invention is not impaired. Examples of the modifying monomer include propylene, 1-butene, 1-hexene, and 4-methyl -1-pentene, acrylate, methacrylate,
Maleic acid, phthalic acid, itaconic acid, higher fatty acid vinyl ester, alkyl vinyl ether, N-vinylpyrrolidone, N-normal butoxymethyl acrylamide, N
-(2-Dimethylaminoethyl) methacrylamides or quaternary compounds thereof, N-vinylimidazole or quaternary compounds thereof can be exemplified.

Next, the water-swellable phyllosilicate (A ₂ ) contained in the EVOH used in the present invention will be described. A typical structure of a water-swellable phyllosilicate is [S
i-O tetrahedral sheet-like structure] and [A1-O or Mg
-O octahedral sheet-like structure] as one unit (hereinafter, referred to as flakes). The size of the flake, which is one unit of the water-swellable phlosilicate, is approximately 1 μm in average particle size.
m or less, the distance between flakes (bottom distance y) is about 20
Angstroms or less. The swelling property of the water-swellable phyllosilicate referred to in the present invention refers to the property of coordinating water between flakes, absorbing and swelling, and in some cases, the flakes or a part thereof are dispersed to form colloids. As the water-swellable phyllosilicate contained in EVOH, at least the flakes of the phyllosilicate are at least partially separated and dispersed at least by utilizing this swelling property in the form of fine particles obtained. Optimally, it is present in EVOH.

That is, in the present invention, the EVOH resin composition (A) 40 containing a water-swellable phyllosilicate is used.
To 95% by weight and 60 to 5% by weight of polyamide resin (B)
In the resin composition comprising, it is most preferable that the spacing between the bottom surfaces of the water-swellable phyllosilicate contained in EVOH satisfies the following formula (I). (X−y) ≧ 2 (I) where x is the distance between the bottom surfaces (angstrom) of the water-swellable phyllosilicate dispersed in EVOH in the resin composition,
y is the bottom distance (angstrom) of the dry powder of the water-swellable phyllosilicate. Note that x and y are values obtained by measuring the bottom interval by X-ray diffraction.

Further, in the resin composition of the present invention, it is more effective that the water-swellable phyllosilicate is uniformly dispersed in EVOH. Here, the uniformly dispersed phyllosilicate refers to EVO containing phyllosilicate.
It refers to a state in which there are almost no aggregates or local aggregates of phyllosilicate in optical microscope observation (magnification: 10 times) of the surface and cross section of the film obtained from the melt casting of the H composition. The raw materials of the water-swellable phyllosilicate are clay minerals such as smectite and vermiculite, and also synthetic mica.
An example is a steven site. These may be natural or synthetic. Among these, smectite, especially montmorillonite is preferred. In order to uniformly disperse and contain the phyllosilicate in EVOH, it is preferable that the phyllosilicate is in a colloidal state of an aqueous sol. These phyllosilicates may be used alone or in combination of two or more.

The content of the phyllosilicate is 0.05 to 30% by weight with respect to the EVOH, preferably 0.1 to 15% by weight.
%, More preferably 1 to 10% by weight. If the content of the phyllosilicate is less than 0.05% by weight, the effect of improving gas barrier properties is low, which is not preferable. Meanwhile, 3
If it exceeds 0% by weight, the melt viscosity will increase significantly, which is not preferable.

Next, the polyamide resin (B) which is one of the resins forming the resin composition of the present invention is a lactam having three or more membered rings, a polymerizable ω-amino acid, or a dibasic acid and a diamine. Is a polyamide obtained by the polycondensation of Specifically, polycapramide (nylon-6), poly-ω-aminoheptanoic acid (nylon-7), poly-ω-
Aminononanoic acid (nylon-9), polyundecaneamide (nylon-11), polylauryl lactam (nylon-12), polyethylenediamine adipamide (nylon-2,6), polytetramethylene adipamide (nylon-4, 6), polyhexamethylene adipamide (nylon-6, 6), polyhexamethylene sebacamide (nylon-6, 10), polyhexamethylene dodecamide (nylon-6, 12), polyoctamethylene adipamide (Nylon-8, 6), polydecamethylene adipamide (nylon-10, 8), or caprolactam / lauryl lactam copolymer (nylon-6 / 12), caprolactam / ω-aminononanoic acid copolymer (nylon- 6 /
9), caprolactam / hexamethylene diammonium adipate copolymer (nylon-6 / 6, 6), lauryl lactam / hexamethylenediammonium adipate copolymer (nylon-12 / 6, 6), hexamethylene diammonium adipate / Hexamethylenediammonium sebacate copolymer (nylon-6, 6/6, 1
0), ethylene diammonium adipate / hexamethylene diammonium adipate copolymer (nylon-
2,6 / 6,6), caprolactam / hexamethylenediammonium adipate / hexamethylenediammonium sebacate copolymer (nylon-6 / 6,6 / 6,1)
0), polyhexamethylene isophthalamide (nylon-6, I), polyhexamethyleneterephthalamide (nylon-6, T), hexamethyleneisophthalamide /
Terephthalamide copolymer (nylon-6, I / 6,
T) and the like.

In these polyamide resins, a diamine such as an aliphatic diamine introduced with a substituent such as 2,2,4- and 2,4,4-trimethylhexamethylenediamine, methylbenzylamine or meta-xylylenediamine is used. Such an aromatic amine may be used or the polyamide resin may be modified. Further, a substituted aliphatic carboxylic acid such as 2,2,4- and 2,4,4-trimethyladipic acid as a dicarboxylic acid,
Use of alicyclic dicarboxylic acid such as 1,4-cyclohexanedicarboxylic acid, phthalic acid, xylylenedicarboxylic acid, alkyl-substituted tere and isophthalic acid, aromatic dicarboxylic acid such as naphthalenedicarboxylic acid, or modification to polyamide resin You can do it.

These polyamide resins may be used alone or in combination of two or more. Among these polyamide-based resins, a hexamethylene isophthalamide / terephthalamide copolymer (nylon-6, I / 6, T) is preferable for the present invention. Above all, the molar ratio of I (isophthalic acid) / T (terephthalic acid) is 60/40 to 100/0, and more preferably 65/35 to 90.
A hexamethylisophthalamide / terephthalamide copolymer in the range of / 10 is preferred. Another polyamide resin suitable for the present invention is caprolactam / lauryl lactam copolymer, that is, nylon-6 / 12.
And the main component is. The composition of the 6 components and the 12 components is not particularly limited, but the 12 components are 5 to 60% by weight,
More preferably, the content is 5 to 50% by weight.
The relative viscosity of these polyamide resins is not particularly limited as long as there is no problem in a heat-stretched multilayer container obtained from a composition with the EVOH resin composition (A) in which the water-swellable phyllosilicate is uniformly dispersed. But 1.0-
It is often 4.0.

Next, a method for dispersing the phyllosilicate in EVOH so as to satisfy the above formula (I) and a method for uniformly dispersing the phyllosilicate in EVOH will be described. As described above, it is important that the phyllosilicate flakes are present in the EVOH substantially in the form of fine particles obtained by separating and dispersing at least partially at least partially. EVO) with almost no phyllosilicate aggregates or local agglomerates
Preferably, it is dispersed in H.

As a method for obtaining the dispersion state, EVO
A typical method is to mix H and the water-swellable phyllosilicate in the presence of water and then dry. More specifically, an alcohol such as methyl alcohol, n-propyl alcohol, or isopropyl alcohol, and optionally water, and EVOH are added to a colloidal phyllosilicate dispersion having water as a dispersion medium, followed by heating and stirring,
After dissolving the EVOH, the resulting solution is cooled and solidified, then pulverized,
Drying and pelletizing may be used. Also, E
A method of heating and dissolving EVOH in the above-mentioned alcohol-water mixed solvent which is a solvent of VOH, adding and stirring a phyllosilicate to the EVOH solution, solidifying by cooling, pulverizing, drying and pelletizing may be employed. . Alternatively, the EVOH solution and water or the above-mentioned alcohol-water mixed solvent or the like are mixed and stirred with a colloidal phyllosilicate dispersion forming a sol as a dispersion medium, followed by cooling and solidification, followed by pulverization. A method of drying and pelletizing may be employed. Furthermore, an aqueous composition such as an EVOH solution containing a high concentration of phyllosilicate is prepared in advance by the method described above,
A method of melt-kneading this and EVOH may be used.
In addition, a method may be used in which a phyllosilicate is dropped into an aqueous sol and kneaded while melting at a temperature equal to or higher than the melting point of EVOH by using a melt kneader (such as a vent-type melt kneader). The drying conditions after mixing the EVOH and the phyllosilicate may be either forced drying or natural drying, but it is preferable to set conditions such that the remaining amount of the solvent (water or water-alcohol) is as small as possible. .

On the other hand, in a method in which EVOH (powder or pellet) and a dry clay mineral as a raw material of phyllosilicate are melt-kneaded at a temperature not lower than the melting point of EVOH and in the absence of water, the clay is mixed in EVOH. Mineral aggregates are observed and the composition of the present invention cannot be obtained. The composition of the present invention is a mixture of the above-described EVOH resin composition (A) in which the water-swellable phyllosilicate is uniformly dispersed and the polyamide resin (B). / B =
95/5 to 40/60, preferably 90/10
60/40. If the amount of the polyamide resin (B) is less than 5%, the effect of improving the moldability is not sufficient, and cracks and unevenness tend to occur. On the other hand, if it exceeds 60%, the original gas barrier function becomes insufficient.

The mixing is not particularly limited, but the EVOH resin composition (A) and the polyamide resin (B) are dry-blended and used as they are, or more preferably, a conventionally known Banbury mixer, There is a method of pelletizing and drying with a single screw or twin screw extruder or the like. If the blend is non-uniform or there is gel or lumps during the blend pelletizing operation, the secondary workability will decrease.Use an extruder with a high degree of kneading during the blend pelletizing operation, and seal the hopper port with nitrogen. It is preferable to extrude at the lowest possible temperature.

The resin composition of the present invention contains other thermoplastic resins, fillers, and the like as long as the object of the present invention is not impaired.
It is free to add a plasticizer, a lubricant, a desiccant, an antioxidant, a heat stabilizer, an ultraviolet absorber, a colorant, and the like. In particular, it is preferable to add one or two of a hydrotalcite-based compound, a metal salt of a higher fatty acid such as potassium stearate, magnesium acetate, a hindered phenol-based heat stabilizer, and a hinderamine-based heat stabilizer as a measure for preventing gelation. It is. It may also be preferable to incorporate a desiccant, wherein the desiccant is a hydrate-forming salt, that is, a salt that absorbs water as water of crystallization, especially monosodium phosphate, disodium phosphate, Phosphates such as trisodium phosphate, trilithium phosphate and sodium pyrophosphate, their anhydrides and other hydrate-forming salts (eg, sodium borate, sodium nitrate, sugar, silica gel), superabsorbent resins And so on.

The resin composition of the present invention comprises a single-layer film,
It is used as at least one layer of the laminate, especially as an intermediate layer, for solution coating and the like. In the film forming, the film is formed into an unstretched film or a stretched film by a usual method, and the production conditions are not particularly limited.
Further, at least one layered product, especially when used for the intermediate layer, the resin used for the layer to be laminated with the resin composition of the present invention is not particularly limited, for example, polyethylene, polypropylene, polyolefin such as polybutene,
Examples thereof include copolymers mainly composed of olefins, polystyrene, polyethylene terephthalate, polycarbonate, polyamides such as nylon-6 and nylon 6,6, polyvinylidene chloride and the like, and mixtures thereof.
Of these, polyethylene, polypropylene alone or a mixture thereof is particularly preferably used. When used as a part of the laminate, a recovery layer may be provided as necessary to effectively use an unused portion generated when the container is formed from the laminate (sheet).

The resin composition of the present invention can be easily laminated with these thermoplastic resins. Further, by laminating these thermoplastic resins, the resin composition of the present invention is protected and reinforced, and can be used under high humidity. Prevents deterioration of the gas barrier properties and imparts excellent mechanical strength.

When the interlayer adhesion between these resins and the resin composition of the present invention is not sufficient, it is preferable to provide an adhesive resin layer. The adhesive resin is not particularly limited as long as it does not cause delamination in a practical stage. Unsaturated carboxylic acids or anhydrides thereof are converted to olefin-based polymers (for example, polyolefins such as polyethylene, polypropylene and polybutene, and olefins). Modified olefin polymers containing a carboxyl group, which are obtained by chemically (eg, addition reaction, graft reaction) bonding to a main copolymer). Specifically, one selected from maleic anhydride graft-modified polyethylene, maleic anhydride graft-modified polypropylene, maleic anhydride graft-modified ethylene-ethyl acrylate copolymer, maleic anhydride graft-modified ethylene-vinyl acetate copolymer or Preferred are mixtures of the two. In addition, EVOH can be mixed with these adhesive resins within a range that does not impair the effects of the present invention.

The method for obtaining a laminate having at least one layer of the resin composition of the present invention is not particularly limited, and examples thereof include a coextrusion method, a solution coating method, an extrusion lamination method, and a dry lamination method. The resin composition of the present invention can be subjected to secondary processing by heat stretching by a usual method as a single layer or a laminate, and a heat-stretched multilayer structure can be obtained. Here, the heat-stretched multilayer structure in the present invention is a container or a sheet such as a cup or a bottle obtained by heat-stretching, a film-like material, and the heating is required to heat-stretch the multilayer structure. This is a method in which the multilayer structure is left at a predetermined temperature for a predetermined time, and is operated by heating with a heater or the like so that the multilayer structure is substantially thermally uniform. The stretching operation is performed by chucking a multilayer structure that is thermally uniformly heated by a chuck, plug,
It refers to the operation of uniformly forming into containers, cups, bottles, and films by vacuum force, pneumatic force, or the like. In the present invention, the moisture content of the resin composition is not particularly limited. Ordinary molding methods such as injection molding, blow molding and stretch blow molding can also be used. The molded article thus obtained is suitable for general food packaging, retort food packaging, and pharmaceutical packaging containers.

[0030]

The present invention will be described in more detail with reference to the following examples, which should not be construed as limiting the present invention.

The measurement items in the examples were performed by the following methods. (1) Melt index According to MI ASTM D1238 65T, at 190 ° C, 2
It was measured under the condition of a 160 g load. (2) Oxygen permeation amount OX-TRAN manufactured by OTR Modern Control
The OTR was measured at 20 ° C. and 100% RH using 10 / 50A. (3) Dispersibility Presence or absence of aggregates or local aggregates of phyllosilicate in optical microscopic observation (magnification: 10 times) of the surface and cross section of the film obtained from melt-forming the EVOH composition containing phyllosilicate. Was observed. (4) Montmorillonite content The montmorillonite content was determined by firing residue of the montmorillonite-containing pellets. The other inorganic-containing pellets were similarly determined.

(5) Bottom distance Measured with an X-ray diffractometer manufactured by Rigaku Corporation. Use of a film obtained by melt-forming a resin composition comprising an EVOH composition containing a phyllosilicate and a polyamide resin and a phyllosilicate powder (a dry film or a dry powder treated at 50 ° C. for 48 hours in air). did. The distance between the bottom surfaces was measured, and the difference (xy) between them was determined.
Here, x is the bottom spacing (angstrom) of the water-swellable phyllosilicate uniformly dispersed in EVOH in the resin composition, and y is the bottom spacing (angstrom) of the dry powder of the water-swellable phyllosilicate. (6) Thermoforming The sheet was thermoformed using a vacuum press forming machine manufactured by Asano Research Institute Co., Ltd., and the appearance (thermoformability) of the molded container was observed. The shape of the molded container has a bottom surface with a radius of 33 mm,
The upper opening is a circular cup having a radius of 37 mm and a height of 37 mm. (7) Melting point The melting point was measured at a heating rate of 10 ° C./min in a nitrogen atmosphere using a DSC 30 manufactured by Mettler.

Example 1 To a vessel equipped with a stirrer, 1.5 parts of montmorillonite (Kunimine Kogyo Co., Ltd., Kunipia-F) was added to form a water dispersion having a concentration of 5% by weight, and the mixture was stirred. The colloid was adjusted. The ethylene content was 32 mol%, the saponification degree of the vinyl acetate component was 99.5 mol%,
EVOH with a melting point of 182 ° C.
Methyl alcohol and water were added so that 5 parts, the EVOH concentration was 10% by weight, and the methyl alcohol concentration was 65% by weight, and the mixture was heated and stirred to dissolve the EVOH, thereby preparing a mixed solution of montmorillonite and EVOH. Subsequently, the container containing the mixed solution was cooled with ice water to solidify the solution, and the solid was pulverized with a mixer.
For 12 hours to obtain an EVOH resin composition (A).
80 parts by weight of the EVOH resin composition (A) and the polyamide resin (B) (hexamethylene isophthalamide / terephthalamide copolymer); the diamine component is hexamethylene diamine, and the acid components are isophthalic acid (I) and terephthalic acid (T ), The ratio of which is I / T = 70 /
30 parts) was placed in a twin-screw, vented 40φ extruder and extruded at 220 ° C. in the presence of nitrogen to form an extrusion blend pellet.

Subsequently, the pellets were used and the die temperature was 22
At 0 ° C. and a cylinder temperature of 220 ° C., a single-layer film (P) (25 μ) was obtained with an extruder connected to a T-die. A single-layer film (Q) (25 μ) was obtained in the same manner for the EVOH resin composition (A).

On the other hand, a laminated sheet of three types and five layers having the pellets as an intermediate layer is formed by using an extruder for an inner / outer layer, an extruder for an intermediate layer, and an extruder for an adhesive layer having branched melt channels. A combination of extruders having
Obtained using a T-die. The resin used for molding is the above-mentioned blend pellets for the intermediate layer, polypropylene (Mitsubishi Yuka, Noblen PY220) for the inner and outer layers, and polypropylene (Mitsui Petrochemical, Admer QF500) modified with maleic anhydride for the adhesive layer. The molding temperature is set to the extruder 220 for the intermediate layer.
° C, extruder 230 for inner and outer layers, extruder 230 for adhesive layer
℃, T die 230 ℃. The thickness of the laminated sheet is 50/1 as outer layer / adhesive layer / intermediate layer / adhesive layer / inner layer.
0/50/10/50 (μ) (R) and 425/50
/ 50/50/425 (μ) (S).

The bottom spacing of montmorillonite was measured using a single-layer film (P), the dispersibility was measured using a single-layer film (Q), and the OTR was measured using a laminated sheet (R). Thermoforming was performed on the laminated sheet (S). Table 1 shows the results.

Example 2 The amounts of montmorillonite and EVOH used in Example 1 were 3 parts for montmorillonite and 97 parts for EVOH.
A single-layer film and a laminated sheet were prepared in the same manner as in Example 1 except that the parts were used, and the same measurement was performed. Table 1 shows the results.

Example 3 The amounts of montmorillonite and EVOH used in Example 1 were 5 parts of montmorillonite and 95 parts of EVOH.
A single-layer film and a laminated sheet were prepared in the same manner as in Example 1 except that the parts were used, and the same measurement was performed. Table 1 shows the results.

Example 4 A single-layer film and a laminated sheet were prepared in the same manner as in Example 2 except that the mixing ratio was changed to A / B = 90/10 (weight ratio). A measurement was made. Table 1 shows the results.

Comparative Example 1 The procedure of Example 1 was repeated except that only EVOH of Example 1 was used.
A single-layer film and a laminated sheet were prepared in the same manner as described above, and the same measurement was performed. Table 1 shows the results.

Comparative Example 2 In Example 2, instead of the EVOH resin composition (A), 97 parts by weight of EVOH and 3 parts by weight of montmorillonite as in Example 2 were mixed well with a Hensyl mixer. A single-layer film and a laminated sheet were prepared in the same manner as in Example 2 except that pellets formed by an extruder were used at a temperature of 200 ° C. and a cylinder temperature of 220 ° C., and the same measurement was performed. Table 1 shows the results.

Comparative Example 3 A single layer film and a laminated sheet were prepared in the same manner as in Comparative Example 2 except that talc was used instead of montmorillonite in Comparative Example 2, and the same measurement was performed. Table 1 shows the results.

Comparative Example 4 Comparative Example 2 was repeated except that mica (water-non-swellable natural mica) was used in place of montmorillonite.
A single-layer film and a laminated sheet were prepared in the same manner as described above, and the same measurement was performed. Table 1 shows the results.

Comparative Example 5 A single-layer film and a laminated sheet were prepared in the same manner as in Comparative Example 2 except that bentonite was used instead of montmorillonite in Comparative Example 2, and the same measurement was performed.
Table 1 shows the results.

Comparative Example 6 EVOH having an ethylene content of 64 mol%, a saponification degree of a vinyl acetate component of 99.3 mol%, and a MI of 25.0 g / 10 min
And the n-propylene alcohol concentration is 80% by weight.
A single-layer film and a laminated sheet were prepared in the same manner as in Example 2 except that the adjustment was performed so that the same measurement was performed. Table 1 shows the results.

Comparative Example 7 EVOH having an ethylene content of 18 mol%, a degree of saponification of a vinyl acetate component of 99.4 mol%, and an MI of 7.5 g / 10 min (measured at 210 ° C.) was used.
A single-layer film and a laminated sheet were prepared in the same manner as in Example 2 except that the adjustment was made to be 5% by weight, and the same measurement was performed. Table 1 shows the results.

Comparative Example 8 A single-layered film was prepared in the same manner as in Example 2 except that the EVOH resin composition (A) / polyamide resin (B) was changed to 30/70 (parts by weight). A laminated sheet was prepared and the same measurement was performed. As a result, a large number of lumps were found at the time of producing the film and sheet, and the film and sheet were unusable.

Comparative Example 9 A single-layer film and a single-layer film were prepared in the same manner as in Example 2 except that the EVOH resin composition (A) / polyamide resin (B) was changed to 97/3 (parts by weight). A laminated sheet was prepared and the same measurement was performed. Table 1 shows the results.

Comparative Example 10 Instead of the EVOH resin composition (A) in Example 2, only the EVOH of Example 2 and the polyamide resin (B) were used.
A single-layer film and a laminated sheet were prepared in the same manner as in Example 2 except for using, and the same measurement was performed. Table 1 shows the results.

[0050]

According to the present invention, a resin composition having high gas barrier properties and excellent workability without pinholes, cracks, local unevenness in thickness during a heat stretching operation, and at least one layer of this composition A laminate and a heat-stretched multilayer container can be obtained.

[Table 1]

──────────────────────────────────────────────────の Continuation of front page (51) Int.Cl. ⁷ identification symbol FI C08L 29/04 C08L 29/04 S 77/00 77/00 (58) Field surveyed (Int.Cl. ⁷ , DB name) C08L 23/08 C08L 29/04 C08L 77/00 C08K 3/34 C08K 7/26 B32B 27/28

Claims (4)

(57) [Claims] 1. An ethylene-vinyl alcohol copolymer (A ₁ ) having an ethylene content of 20 to 60 mol% with respect to EVOH.
Was made 0.05 to 30 wt% of the water-swellable phyllosilicate (A ₂₎ and polyamide resin (B) and, and the total amount of (A ₁₎ and (A ₂₎ (A) 40 to 95 % By weight and (B) 60 to 5% by weight. 2. 0.05 to 30% by weight based on EVOH
Content of water-swellable phyllosilicate containing 20
An ethylene-vinyl alcohol copolymer (EVOH) resin composition (A) of 40 to 95% by weight and a polyamide resin (B) of 60 to 5% by weight,
A resin composition in which the distance between the bottom surfaces of the water-swellable phyllosilicate contained in the OH resin composition satisfies the following formula (I). (X−y) ≧ 2 (I) where x is the distance between bases (angstrom) of the water-swellable phyllosilicate uniformly dispersed in EVOH in the resin composition, and y is the drying of the water-swellable phyllosilicate. It is the distance between the bottoms of the powder (angstrom). 3. An EVO having an ethylene content of 20 to 60 mol%.
A water-swellable phyllosilicate of 0.05 to 30% by weight based on H and EVOH is mixed in the presence of water to form an EVOH tree.
After the fat composition (A) was dried, the polyamide resin (B) was mixed with (A) and (B) in a weight ratio of 9
A method for producing a resin composition, wherein the resin composition is melt-mixed so as to be 5/5 to 40/60 . 4. A laminate having at least one layer comprising the resin composition according to claim 1 or 2.