JPH08217942A - Raw material composition for oxygen-gas barrier laminate and laminate produced therefrom - Google Patents

Abstract

PURPOSE: To obtain a raw material compsn. for an oxygen-gas barrier laminate improved in tensile modulus and low-temp. impact resistance by compounding a specific saponified ethylene-vinyl acetate copolymer with a specific styrene copolymer elastomer. CONSTITUTION: This compsn. comprises 68-50vol.% saponified ethylene-vinyl acetate copolymer having an ethylene content of 30-50mol% and a degree of saponification of 90% or higher and 32-50vol.% acid-modified styrene copolymer elastomer having an acid value of 1-20mgCH3 ONa/g). An oxygen-gas barrier laminate having a tensile modulus recovery of 50-99% and a tensile modulus of 100-400MPa is produced by using the compsn. for forming at least one layer of the laminate.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a raw material composition for a laminate and its use. More specifically, it is mainly composed of a saponified ethylene-vinyl acetate copolymer (hereinafter may be simply referred to as EVOH resin), and has tensile elasticity while maintaining the oxygen gas barrier property and transparency which are the characteristics of the EVOH resin. Rate, low-temperature impact resistance improved oxygen gas barrier laminate material composition, and chlorine-free when incinerated environment-friendly adhesion (hereinafter sometimes referred to as skin pack) suitable for packaging The present invention relates to an oxygen gas barrier laminate (hereinafter, may be simply referred to as a laminate).

[0002]

2. Description of the Related Art Conventionally, as a packaging material having an oxygen gas barrier property, a film made of polyvinylidene chloride, EVOH resin or the like, or a nylon film made of polyamide, coated with polyvinylidene chloride latex to form a thin film,
A film obtained by laminating a film of another resin on an EVOH resin film using chlorinated polyethylene as an adhesive has been widely used. However, polyvinylidene chloride, chlorinated polyethylene, and other substances that contain chlorine generate chlorine gas when used after incineration, dioxin is found in the incinerator, and chlorine gas diffused into the atmosphere is acidic. It is said that it is said to be one of the causes of rain, so its use may be restricted.

The EVOH resin does not have the above-mentioned problems, but has a drawback in that it has a too high tensile elastic modulus and is not suitable for use in contact packaging. Further, the EVOH resin has a low temperature impact resistance and has a drawback that it becomes brittle when the temperature is lowered. Conventionally, when the EVOH resin is used for close-pack packaging, a technique of adding another resin that imparts softness to the EVOH resin has been adopted. Further, in order to improve low temperature impact resistance, a method of laminating a film having excellent low temperature characteristics such as a nylon film which is a polyamide on an EVOH resin film has been adopted.

Conventionally, resins used as a mixture for imparting flexibility to EVOH resins are mainly styrene copolymer elastomers such as styrene / butadiene block copolymers (hereinafter simply referred to as styrene elastomers). There is). Styrene-based elastomer has the excellent oxygen gas barrier property of EVOH resin in terms of oxygen permeability of the laminate of 200 (cm ³ / m ² / 24h / at).
Beyond m), flexibility can be imparted without deteriorating the oxygen gas barrier property. For this reason, a film composed of a resin composition containing both resins is arranged as a gas barrier layer and laminated with a layer composed of other resins to form a multilayer (laminated) film or sheet, which is a packaging for contents such as foods to be stored for a long period of time. It is used for The film thickness is about 1 to 400 μm, and the sheet thickness is 400 to
It is about 2000 μm. Hereinafter, unless otherwise specified, a film is a film or a sheet. When the object to be packaged is large, the amount of distortion of the film or sheet during the packaging process is large, so a thicker sheet is suitable. As described above, the packaging film or sheet is required to have various physical properties depending on the use form. For example, for meat packaging applications that use the close-packing method, (1) it should be transparent enough to observe the color and luster of the contents, (2)
In order to carry out the close packing work smoothly, it is required to have both properties of low tensile elastic modulus.

In a combination of resins that are incompatible with each other,
If the difference in the refractive index between the two is large, the product obtained from the mixed composition diffuses light at the interface between the two resins, so that the transparency of the product obtained from the mixed composition deteriorates. Therefore, when different kinds of resins are combined, it is necessary to minimize the difference in refractive index between the combined resins. Various resins currently on the market have a specific refractive index for each resin as shown in Table 1. If the difference in refractive index between the two resins is 0.02 or more, the haze value (= Haze) of the mixed composition becomes large, and the haze value becomes 20% or more, resulting in poor transparency.

[0006]

[Table 1]

The above-mentioned styrene elastomer and EVOH
For the purpose of utilizing the excellent physical properties of different resins themselves, such as a combination of resins, a method of mixing different resins with a compatibilizer (resin indirect resin) is used. It In the case of a combination of a styrene elastomer and an EVOH resin, for example, JP-A-4-1821
Japanese Patent No. 26 discloses an example in which three kinds of resins, EVOH resin, styrene elastomer and polyolefin resin, are mixed by using a special acid-modified ethylene copolymer as a compatibilizer. In this example, the difference between the refractive index of the EVOH resin of 1.51 and the refractive index of the acid-modified ethylene-based copolymer of 1.49 is 0.02, and the transparency is not good. Further, in JP-A-4-185334, an example in which three kinds of resins, EVOH resin, styrene elastomer and polyolefin resin, are mixed by using a special ethylene copolymer having an epoxy group as a compatibilizer Is listed. In this example, the refractive index of EVOH resin is 1.51.
And the difference in the refractive index of 1.44 of the ethylene copolymer having an epoxy group is 0.07, and the transparency is also not good.

In the food packaging work, it is necessary that the tensile elastic modulus of the packaging film is low in order to smoothly perform the close packaging work. EVOH resin itself has a high tensile elastic modulus and is not suitable for close-packing.

Japanese Patent Publication No. 2-15569 describes a resin composition obtained by mixing a styrene elastomer and a vinyl ester polymer. In this example, the styrene elastomer is a modified block copolymer of a block copolymer having a vinyl aromatic compound polymer block and an olefin compound polymer block with an unsaturated dicarboxylic acid or a derivative thereof. On the other hand, as the vinyl ester-based polymer, a saponified ethylene-vinyl acetate copolymer is exemplified. In Examples 10 and 11, SEBS (synonymous with styrene-ethylene-butadiene block copolymer), which is a styrene-based elastomer, and ethylene-vinyl alcohol copolymer manufactured by Kuraray Co., Ltd. under trade names EVAL, EP-
E (corresponding to EVOH resin) in a weight ratio of 25:75
(Corresponding to volume ratio 29.5: 70.5), weight ratio 10: 9
In the example of mixing and kneading at a ratio of 0 (corresponding to a volume ratio of 12.2: 87.8), SEBS is uniformly dispersed as particles of about 0.5 to 2 μm in the matrix of EVAL and EP-E. It is described that the above-mentioned form is obtained. In addition,
The product names EVAL and EP-E manufactured by Kuraray Co., Ltd. have an ethylene content of 44 mol% and thus a density of 1.14 (g / cm ³ ). Moreover, in Examples 13 and 14, SEBS and EV were used.
A composition mainly composed of AL and EP-E was prepared at 20:25.
(Parts by weight) and 20:10 (parts by weight) are mixed and kneaded.

However, according to the experiments conducted by the present inventors, in the mixed composition described in this publication, when too much EVOH resin occupies the mixed composition, the tensile modulus of the film obtained from the mixed composition is large. Was found to be too high to be suitable for tight packaging. On the other hand, it was also found that when the EVOH resin contained in the mixed composition was too small, the oxygen gas barrier property was lowered.

[0011]

DISCLOSURE OF THE INVENTION The object of the present invention is to provide an EV
Oxygen gas barrier material having excellent oxygen gas barrier property and transparency, which are improved by the OH resin itself, and improved tensile elastic modulus and low temperature impact resistance, and the oxygen gas barrier property A laminate including a layer from the raw material composition for a laminate, which is capable of smoothly performing a close-packing operation, and which is suitable for environment-friendly skin pack packaging that does not generate chlorine gas when incinerated after use. To provide.

[0012]

In order to solve the above problems, in the first aspect of the present invention, a saponified ethylene-vinyl acetate copolymer {(E) component} and an acid-modified styrene copolymer elastomer {(S Component), the component (E) has an ethylene content of 30 to 50 mol% and a saponification degree of 90% or more, (S) The component has an acid value of 1 to 20 (mgC
H ₃ ONa / g) and the ratio of the (E) component to the (S) component is 68/32 (volume%) to 50.
The raw material composition for an oxygen gas barrier laminate is provided in the range of / 50 (volume%).

In the present invention, a raw material composition for an oxygen gas barrier laminate containing a saponified ethylene-vinyl acetate copolymer {(E) component} and an acid-modified styrene copolymer elastomer {(S) component}. In the melt extruder, the ethylene content is 30 to 50 mol% and the saponification degree is 90% or more of the component (E), and the acid value is 1 to 20 (m.
gCH ₃ ONa / g) in the range of (S) component, (E)
The ratio of the component to the (S) component is 68/32 (volume%) to 50
In the range of 50/50 (volume%), and the component (E) and the component (S) are mixed with each other from the extruder to the lip portion of the die in the process of pelletizing or forming a film or sheet using a circular die or the like. Until the melt viscosity ratio of these two components satisfies 0.2 to 10, the die flow path shape, die lip clearance and extrusion amount are set to determine the shear rate, and the melting temperature at that time is set to 19
It is preferably set to ⁰ to 240 ° C. and a shear rate of 10 to 200 sec ⁻¹ . Thereby, the melt viscosity is uniquely determined, and the melt viscosity ratio [= {(E) component} / {(S) component}] is set to 0.
The raw material composition for the oxygen gas barrier laminate can be produced by melt extrusion under the condition of 2 to 10.

A second aspect of the present invention is an oxygen gas barrier laminate having at least one layer composed of the raw material composition for oxygen gas barrier laminate, wherein the tensile elastic recovery rate of the laminate is 50 to 99. %, And the tensile elastic modulus is in the range of 100 to 400 MPa, thereby providing an oxygen gas barrier laminate.

[Description of Configuration of the Invention] The present invention will be described in detail below. I. Raw Material Resin The raw material composition for an oxygen gas barrier laminate according to the present invention contains the above-mentioned component (E) and component (S) as raw materials. Hereinafter, each raw material resin component will be described.

Component (E): The component (E) is a saponified ethylene-vinyl acetate copolymer (EVOH resin), which is a resin component exhibiting an oxygen gas barrier property. The EVOH resin is usually an ethylene-vinyl acetate copolymer, or a copolymer containing a small amount of other copolymer components therein, dispersed in alcohol or a mixed solution containing alcohol as a main component,
It is obtained by adding a caustic alkali or the like to this dispersion solution and saponifying it.

According to the experiments conducted by the present inventors, in order to effectively achieve the object of the present invention, the EVOH resin has an ethylene content of 30 to 50 mol% and a saponification degree of 90%. It turned out that it was necessary to be above. When the ethylene content is less than 30 mol%, the melting point and the thermal decomposition temperature are close to each other, and melt molding becomes difficult. On the other hand, when the ethylene content exceeds 50 mol%, not only the oxygen gas barrier property is deteriorated, but also the crystal melting point is lowered, and heating during sterilization by boiling may cause uneven film adhesion, which is not preferable. When the degree of saponification is less than 90%, the oxygen gas barrier property is deteriorated, and there is no practical use.

Component (S): The component (S) is an acid-modified styrene copolymer elastomer, which is flexible to EVOH resin,
Performs the function of imparting low temperature impact resistance. The acid-modified styrene copolymer elastomer is a linear chain of a vinyl aromatic compound polymer block and an olefin compound polymer block,
A block copolymer elastomer having a branched or radial molecular structure modified with an unsaturated dicarboxylic acid or a derivative thereof.

According to the experiments of the present inventors, in order to effectively achieve the object of the present invention, the acid value by the test method (10) sodium methylate titration method described later is 1 to 20 (mgCH.
It has been found that it is necessary to set the range to ₃ ONa / g). When the acid value is less than 1 (mgCH ₃ ONa / g), the melt viscosity ratio is 0.2 to 10 and the component (E) and the component (S) are
Even if the components are melt-mixed with each other, the specific dispersion form described below peculiar to the composition of the present invention cannot be obtained, which is not preferable. Also,
If the acid value exceeds 20 (mgCH ₃ ONa / g),
When a styrene copolymer elastomer and an unsaturated dicarboxylic acid are used to perform a melt graft reaction in an extruder to produce an acid-modified styrene copolymer elastomer, the residence time in the extruder must be lengthened, and the production The cost is high, which is not preferable.

The olefin compound polymer block constituting the component (S) is a polymer block mainly containing an ethylene block and / or a conjugated diene. Specific examples of the styrene copolymer elastomer include a styrene-ethylene-butadiene block copolymer (hereinafter, "SEBS").
Is abbreviated. Synonymous with hydrogenated product of styrene-butadiene block copolymer or hydrogenated product of styrene-butadiene block copolymer), styrene-butadiene block copolymer, styrene-ethylene-glycidyl methacrylate block copolymer, styrene- Examples thereof include a butadiene-glycidyl methacrylate block copolymer and a styrene-ethylene-butyl methacrylate block copolymer. Of these, SEBS is particularly preferable. SEBS is chemical industry (May issue), p13 (199
It can be manufactured according to the method described in 4).

To carry out the acid modification of the styrene copolymer elastomer, the styrene copolymer elastomer may be graft-reacted with the unsaturated dicarboxylic acid or its derivative.
Examples of the unsaturated dicarboxylic acid include maleic acid, maleic anhydride, fumaric acid, itaconic acid, cis-1,4-cyclohexene-1,2-dicarboxylic acid and its anhydride, endo-cis-bicyclo (2,2,1). ) -5-heptene-2,
3-dicarboxylic acid and its anhydride, maleimide, etc. are mentioned. Of these, maleic anhydride is preferred.

II. Resin composition containing two components The composition containing the above-mentioned component (E) and component (S) do not compatibilize with each other in molecular size. Therefore, depending on the composition ratio of each resin component, 50% by volume or more of the composition ratio A resin (hereinafter, abbreviated as “continuous phase or matrix”) that is a base material of
It is divided into the added resin (hereinafter abbreviated as “discontinuous phase or domain”) having a composition ratio of less than 50% by volume. When the composition containing two components is magnified and observed with an electron microscope, the components occupying 50% by volume or more in the composition ratio form a matrix, and the components less than 50% by volume in the composition ratio form domains. The matrix / domain dispersed form is a standard boundary where the continuous phase and the discontinuous phase are exchanged when the composition ratio of the resin component is 50/50 (volume%). However, in reality, due to fluctuations in the dispersion, the matrix and domain are swapped when the composition ratio of the resin components is 50.
There is a variation of about ± 2% by volume with the volume% as the boundary. Table 3 shows the relationship between the ethylene content and the density of 5 kinds of EVOH having different ethylene contents for reference when preparing the raw material composition for oxygen gas barrier laminates of the present invention. It was The typical density of SEBS is also shown for reference.

In the raw material composition for an oxygen gas barrier laminate according to the present invention, since the component (S) is acid-modified, the resin adhesive force between the two component resins is increased. If it is not acid-modified, the continuous phase and the discontinuous phase are not stably formed, and since the resin adhesive strength at the interface between the continuous phase and the discontinuous phase is weak, interfacial peeling occurs in the stretching operation, Brittle fracture occurs when the laminate becomes cloudy or when the falling cone fracture of the laminate is measured. In both resin composition ratios, (E) component / (S) component = 5
When it is 0/50 to 68/32 (volume%), the component (E) is generated in the resin composition serving as a matrix, and it is not a dispersion form in which it is clearly separated into a matrix / domain or a simple dispersion fluctuation. . More specifically, in the above resin composition ratio range, a form in which the domain (S) component is dispersed in the matrix (E) component and the matrix (S) component in the matrix (S) component This is a unique dispersion form in which both the domain (E) component is dispersed and the domain is dispersed, and is shown in FIG. 1 (drawing substitute photograph) in which the cross section of the molded article of Example 1 described later is enlarged.

In FIG. 1, the white portion is the (E) component, and the black portion is the (S) component. Small black (S) component particles are dispersed in the white (E) continuous phase, and small white (E) component particles are dispersed in the black (S) continuous phase. It is clear that the two are in a unique dispersion form in which both are mixed.

According to the experiments conducted by the present inventors, the oxygen gas barrier property and the tensile elastic modulus of the film obtained from this composition are shown in FIGS. 2 and 3 in the range exhibiting the above-mentioned unique dispersion form (specific range). As shown, it was found to change greatly. FIG. 2 is a diagram showing the relationship between the mixing ratio of the (E) component and the (S) component (horizontal axis), the oxygen permeability, and the tensile elastic modulus (vertical axis). FIG. 3 is a diagram showing the relationship between tensile elastic modulus (horizontal axis) and oxygen permeability (vertical axis).

III. Production of Resin Composition Containing Two Components An extruder is used for producing the raw material composition for oxygen gas barrier laminates according to the present invention using the components (E) and (S) as raw materials. However, according to the experiments by the present inventors, the components (E) and (S) were blended in the above-mentioned specific range,
In order to obtain a peculiar dispersion form, the melt viscosity ratio [= {(E) component} / {(S) component} of the E component and the (S) component in the die lip portion is 0. 2-1
It has been found that it is particularly preferable to control the melt extrusion so as to satisfy 0. By controlling the melt viscosity ratio of both components within the above range, it becomes easy to obtain a specific matrix / domain separation dispersion form, and as a result, the occurrence of fish eyes in the film due to uneven melting can be suppressed. Do you get it. The fish eye is a dissolved resin, an undissolved resin, or a thermal decomposition product of the resin, which is insufficiently melt-dispersed.

The melt viscosity ratio is obtained by controlling the temperature and shear rate of both resin components, and the preferable melt viscosity ratio is as described above. When the melt viscosity ratio is less than 0.2, it is not only difficult to stably obtain a peculiar dispersion form, but also the component (E) becomes fish eyes, which may lower the commercial value, which is preferable. Absent. When the melt viscosity ratio exceeds 10, a clear deviation occurs in the melt flow of both resins at the time when the molten resin comes out of the die lip portion, and thus amorphous stripes or streaks occur in the film or sheet,
This is not desirable because it reduces the commercial value. The range of 1 to 3.5 is particularly preferable in the above range of the melt viscosity ratio. When the melt viscosity ratio is in the range of 0.2 to less than 1,
Depending on the resin composition ratio of the component (E) and the component (S) and the degree of acid modification, the matrix / domain separation form of the extruded resin may change over time, and the quality may not be maintained constant. When the melt viscosity ratio is in the range of more than 3.5 and 10 or less, amorphous stripes or stripes may be formed on the film or sheet depending on the resin composition ratio of the component (E) and the component (S) and the degree of acid modification. It may occur.

A single-screw extruder, a twin-screw extruder, a Banbury mixer, or the like can be used as an extruder for melt-extruding the raw material composition for an oxygen gas barrier laminate, and a full-flight type screw is attached to the extruder. A screw, a kneading type such as a Maddock type screw, a dullage type screw, or a cavity transfer type screw is used. As the die, a T die, a circular die, a die having a single-hole or porous nozzle for pellet production, or the like is used. In the melt extrusion of the raw material composition for an oxygen gas barrier laminate, the melting temperature is 190 to 2
A range of 40 ° C is preferred. A screw type, a cylinder-screw assembly specification, and a screw rotation speed (hereinafter sometimes simply referred to as rpm or rotations / minute) are determined, and the (E) component and the (S) component are mixed with each other in the die lip portion. Melt viscosity ratio [= {(E) component} /
Melt extrusion is performed under the condition that {(S) component}] is 0.2 to 10.

The unique dispersion form formed by melt extruding both components at the above melt viscosity ratio, once formed,
For external factors such as resin temperature and shear rate,
It becomes a metastable dispersed form. That is, when the above-mentioned peculiar dispersion form is formed in the cylinder of the extruder, the peculiar dispersion form is maintained metastable in the route up to the die lip.

IV. Use of Raw Material Composition for Oxygen Gas Barrier Laminate The raw material composition for oxygen gas barrier laminate according to the first aspect of the present invention is used by itself as a molding material to obtain a molded article excellent in oxygen gas barrier property. It can be manufactured. In addition, the raw material composition for an oxygen gas barrier laminate is melt-extruded by an extruder to be used as a film or sheet, and used as a packaging material. The packaging material used for close-packing is
Sealability is important. The film or sheet comprising the raw material composition for an oxygen gas barrier laminate of the present invention can be used as a single layer, but since it has poor sealing property by itself,
In order to impart the sealing property, these resins imparting the sealing property may be laminated as a film or a sheet. As the sealing method, known methods such as heat sealing, impulse sealing, high frequency induction heating sealing, and ultrasonic sealing are adopted. Among these, heat sealing, high frequency induction heating sealing and the like are widely adopted. In these known methods, the sealing surface is melted and sealed, so that the resin that gives the film sealing property has a crystalline melting point or 20% or less.
Those having a Vicat softening point of 0 ° C. or lower are preferable.

Specific examples of resins having a crystalline melting point or a Vicat softening point of 200 ° C. or lower and having excellent sealing properties include low density polyethylene, ethylene-vinyl acetate copolymer, ethylene- ( (Meth) acrylic acid copolymer and an ionomer resin which is a metal neutralized product thereof,
Ethylene- (meth) acrylic acid ester copolymer, propylene-ethylene copolymer (ethylene content 5 to 40% by weight), ethylene-α-olefin (carbon number 6 to 8) copolymer (α-olefin content 10 to 40 wt%) and the like. To produce the laminate according to the second aspect of the present invention, propylene-
Ethylene copolymers and ethylene-α-olefin copolymers are preferred.

To improve the elastic recovery rate of the laminate,
A film or sheet made of a resin having an excellent elastic recovery rate may be laminated on the film or sheet containing the component (E) and the component (S). A thermoplastic elastomer is preferable as the resin having an excellent elastic recovery rate, and specific examples thereof include a styrene elastomer, an olefin elastomer, a urethane elastomer, a polyester elastomer, a polyamide elastomer, polybutadiene, and polyisoprene.

A film or sheet (gas barrier layer) made of the raw material composition for oxygen gas barrier laminate according to the first aspect of the present invention is laminated with a layer having another function to form a gas barrier laminate. The laminate is preferably arranged so as to have at least one gas barrier layer. As a combination for forming a gas barrier laminate, a resin layer (inner layer) that provides sealing properties, a layer that improves the elastic recovery rate (sometimes referred to simply as an elastic recovery auxiliary layer or an outer layer), and a laminate An adhesive layer, which is much thinner than these functional layers, can be disposed between the layers that exert the function of. When the adjacent interface between layers is represented by the symbol “/”, it includes gas barrier layer / adhesive layer / inner layer, outer layer / adhesive layer / gas barrier layer / adhesive layer / inner layer, and the like. In addition, one or more intermediate layers can be arranged between the functional layers. For the intermediate layer, the recovered resin produced during the production of the laminate can be reused.

When the mechanical properties of the laminate according to the second aspect of the present invention are evaluated by (13) the appearance of the skin pack packaging form, the following parameter values corresponding to the mechanical properties correspond to the appearance of the packaging form. , It is easy to understand the practical meaning of the parameter value. Parameter value [tensile elastic modulus of laminated body (MPa) / elastic recovery rate of laminated body (%)] (simply [M
od / R%] is in the range of 1.5 to 5.5, which is useful for practically knowing the good or bad of the laminate of the present invention, particularly the close-packed packaging by the film for skin pack packaging. . When [Mod / R%] is less than 1.5, wrinkles are generated in the appearance of the test method (13) skin pack packaging form described later, the film is too soft and mechanical suitability is poor in automation, and it is difficult to handle manually. [Mo
d / R%] exceeds 5.5, (13) in the appearance of the skin pack packaging form, a bridge is formed between the end of the packing such as bacon and the surface without the packing. The ridge-like form of the film causes the appearance of the film to deteriorate, which lowers the commercial value.

The tensile elastic modulus of the test method (2) described later for the laminate of the present invention is preferably 100 to 400 MPa. (2) When the tensile elastic modulus is less than 100 MPa,
(13) In the appearance of the skin pack packaging form, the film is too soft and mechanically unsuitable for automation, and it is difficult to handle even manually. (2) Tensile elastic modulus is 400M
If it exceeds Pa, not only the rigidity of the film is too large, but also the heat stretching in the skin pack packaging process is small,
(13) In the appearance of the skin pack packaging form, for example, the end portion of the filling material such as bacon is crushed and the appearance is deteriorated, so that the commercial value is reduced.

V. Use of Laminate The above-mentioned laminate according to the second aspect of the present invention is suitable as a film for skin pack packaging in the field of food packaging. In skin pack packaging, a transparent packaging film is closely packaged along the shape of the article to be packaged, and the film after packaging has no wrinkles and an excellent appearance can be obtained. Therefore, for example, it is widely used for packaging sausage, bacon, ham, meat, cheese and the like.

The basic technique of skin pack packaging is to put an article to be packaged on the bottom material, cover with a film or sheet for skin pack packaging that has been softened by heating from above, degas, and then remove this film. Alternatively, it is a method of bringing the sheet into close contact along the shape of the article to be packaged. Various techniques have been proposed for the specific method of packaging the above-mentioned skin pack. Among them, Japanese Patent Publication No. 56-49206 and Japanese Patent Publication No. 57-
In the method described in Japanese Patent No. 23607, a bottom material is drawn by a vacuum die equipped with a heater, and then a packaged object is covered with a recess of the film or sheet, and then a covered film or This is a method of applying a reduced pressure to the inside of the sheet to bring the film or sheet into close contact with the object to be packaged, and has the advantage that automation is also possible.

In skin pack packaging, at the molding temperature (generally 110 to 160 ° C.), the skin pack film or sheet is placed in a mold and preformed by applying a load such as a pressure difference to cover the object to be packaged. After that, the film or sheet is brought into close contact with the object to be packaged by removing the load. Therefore, the film or sheet needs to exhibit rubber-like properties in a heated state. That is, in the molding temperature range, a large amount of rubber elastic molding return with respect to the molding elongation due to the draw molding, that is, a large elastic recovery rate is required.

According to the experiments conducted by the present inventors, the relationship between the molding temperature range and the elastic recovery rate in skin pack packaging was examined, and the tensile elastic recovery rate measured at a temperature of 120 ° C. was 50 to 99%. It has been found that skin pack films or sheets are suitable as skin pack packaging materials. Of skin pack film or sheet,
When the tensile elastic recovery rate at a temperature of 120 ° C. is less than 50%, the curved portion of the corner, which is the stretched portion of the packaged product, becomes excessive and wrinkles, resulting in an excellent appearance. I won't. Tensile elastic recovery rate is 100
% Is ideal, but in reality, when stretch-molded and a certain strain is maintained, stress relaxation occurs over time, and the elastic recovery rate gradually decreases. It is 99%.

[0040]

EXAMPLES The present invention will now be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In the following examples, various physical properties of the film and the laminate are measured by the methods (test methods) described below.

(1) Oxygen permeability (measurement of oxygen gas barrier property) Modern, which is a measuring device based on JIS: K-7126
It was measured using # OX-TRAN2 / 20 manufactured by Controls. Measurement conditions are temperature 30 ℃ and relative humidity 80%
And The unit of the measured value is (cm ³ / m ² / 24h / at
m) or (cm ³ / m ² · 24h · atm), and both have the same meaning. Units of oxygen permeability when the thickness of the gas barrier layer is 15 [mu] m is ^{(cm 3 · 15μm / m 2} / 24h
/ Atm) or (cm ³ · 15 μm / m ² · 24 h · a
tm), and both have the same meaning. (2) Tensile modulus (sometimes referred to as Mod) According to JIS: K-7127, 2.5% strain Seca
nt Modulus was calculated. Using a universal tensile tester, # RTM-100 manufactured by Orientec, the measurement atmosphere was set to a temperature of 23 ° C. and a relative humidity of 50%, and was set to 10 mm / min corresponding to a tensile speed D. The unit of measurement is M
Pa.

(3) Haze Value (= Haze) (Measurement of Transparency) A haze value measuring device conforming to JIS: K-7105.
The measurement was performed using # DH-Σ80 manufactured by Nippon Denshoku Industries Co., Ltd.
The unit of measurement value is%. (4) Tensile elastic recovery rate (sometimes simply referred to as R%) Test length of 50 mm (test piece length of 90 m, provided with a total of 40 mm on both ends of the gripper of the tester, made from a laminate
m), a test piece having a width of 10 mm was tested by pulling in the length direction of the test piece. Using a # 1122 testing machine manufactured by Instron, which is a universal tensile testing machine, a measurement atmosphere temperature is set to 120 ° C., a tensile rate of 500 mm / min is applied, and a strain of 40% of the test length is applied, followed by 2 seconds. The strain recovery rate when the stress was relaxed and then returned until the stress disappeared was defined as the tensile elastic recovery rate. The unit is%.

(5) Melt Viscosity and Melt Viscosity Ratio A resin of a sample, which was dried at a temperature of 60 ° C. for one day to remove water, was used as a dynamic viscoelasticity measuring instrument manufactured by Rheometrics Co.
Using a dynamic threometer, a sample was melted sufficiently uniformly in a measuring machine, and then the melt viscosity was measured. The measurement conditions are a temperature of 210 ° C., a distance between the rotating parallel plates of 2.5 mm
By setting the pressure to 200 Pa and gradually increasing the rotation speed of the rotating parallel plate, the shear rate range is 0.1 to 1,000.
The melt viscosity corresponding to each shear rate was measured up to sec ^-1 . The melt viscosity ratio was calculated based on the formula {(melt viscosity of EVOH resin) / (melt viscosity of acid-modified styrene copolymer elastomer)} at a shear rate of 60 sec ⁻¹ .

(6) Refractive index A refractive index measuring device conforming to JIS: K-0062,
The measurement was performed using #Abbe type T1 manufactured by ATAGO. The measurement temperature was 20 ° C., and the contact liquid was 1-bromonaphthalene. (7) Presence / absence of falling weight and brittle fractures Drop weight measuring instrument #Drop manufactured by Rheometrics
The sample film is 3.8 cm in diameter using Weight Tester.
The film was attached to a ring, and a weight was dropped on the center of the ring to visually observe the fracture mode of whether the film was brittle or not. The conditions of the drop weight test are as follows: atmosphere temperature −10 ° C., weight weight of 4 kg, and weight passing speed at the ring portion of 200.
m / sec. As for the observation result, when the sample film was brittlely broken into a glass, it was indicated as “present”, and otherwise indicated as “absent”.

(8) Density The density was measured by the density gradient tube method according to ASTM: D-1505. The measurement conditions were a liquid temperature of 23 ° C. using a mixed liquid of methyl alcohol and benzyl alcohol. The unit is g / cm ³ . (9) Melt flow rate (MFR) It was measured according to ASTM: D-1238. The unit is (g / 10 minutes).

(10) Acid value by sodium methylate method The acid value was measured by partially changing the test method of JIS: K-0070. The acid is an acid mainly composed of an unsaturated dicarboxylic acid, but in the melt extrusion process, a part of the unsaturated dicarboxylic acid is thermally modified to become an organic or inorganic acid, and therefore an organic or inorganic acid is appropriately added. It may contain an acid. The higher the acid concentration, the higher the acid value. That is, in this test method, a mixed solution in which diethyl ether and ethyl alcohol were mixed at a volume ratio of 2: 1 was used.
A potassium hydroxide ethanol solution is used as a neutralization titration reagent. In the method of the present invention, the mixed solution was not changed, and sodium methylate (= sodium methoxide, CH ₃ ONa) was dissolved in the mixed solution as a neutralization titration reagent to give a 0.1.
It was changed to 1 (mol / liter). The unit of the measured value is (mgCH ₃ ONa / g).

(11) Ethylene content of EVOH resin In a flask with a 100-ml capacity stoppered stopper, EVOH resin 2 was added.
g, 6 ml of acetic anhydride and 12 ml of pyridine, and put 10
The mixture was shaken in an oil bath at 0 ° C., and re-acetylated while being dissolved. The reaction was precipitated with copious amounts of cold water. 0.5N sodium hydroxide solution was added to 0.25 g of this precipitate, and further 25 ml of n-propyl alcohol,
After adding 35 ml of methanol, a reflux condenser was attached to the flask and reacted at 60 ° C. for 3 hours. Next, the inside of the reflux condenser was washed with 10 ml of methanol, and neutralized and titrated with a 0.1N sulfuric acid solution using phenolphthalein as an indicator. When the red color of phenolphthalein disappears,
Let the amount of sulfuric acid solution be Aml, and let Bml be the amount of sulfuric acid solution required for titration in the blank experiment under the same conditions. The ethylene content of the EVOH resin was calculated according to the following formula.

[0048]

[Formula 1] -Acetic acid group C (% by weight) = 0.6 x (BA) x
f / (precipitate weight 0.25 (g)) where f is the titer of 0.1 N sulfuric acid solution. Ethylene content E (mol%) = 100- {28 C /
(60-0.56)}

(12) Degree of saponification of EVOH resin 1 g of EVOH resin was placed in a flask having a capacity of 100 ml, 10 ml of 0.5N sodium hydroxide solution was added, 25 ml of n-propyl alcohol and 3 ml of methanol were added.
After adding 5 ml, attach a reflux condenser to the flask,
The reaction was carried out at 75 ° C for 3 hours. Next, the inside of the reflux condenser was washed with 10 ml of methanol, and neutralized and titrated with a 0.1N sulfuric acid solution using phenolphthalein as an indicator. When the red color of phenolphthalein disappears, the amount of sulfuric acid solution is set to Aml, and the amount of sulfuric acid solution required for titration in a blank experiment under the same conditions is set to Bml. The saponification degree of the EVOH resin was calculated according to the following formula.

[0050]

[Formula 2] -Residual acetic acid group C (% by weight) = 0.6 x (B-
A) × f / {EVOH resin weight (g)} where f is 0.1N
Titrate of sulfuric acid solution-Residual acetic acid group D (mol%) = {C x (44-0.16
E)} / (60-0.42C) -Saponification degree = 100-100D / (100-E)

(13) Appearance of skin pack packaging form Using an #OKKP test chamber packaging machine manufactured by Omori Machinery Co., Ltd., a polystyrene type multilayer bottom material having a thickness of 500 μm,
150 g of bacon was placed, and the film of the present invention was packaged in a skin pack so as to adhere to the bacon. When there are no wrinkles on the film from the end of the bacon to the polystyrene-based multilayer bottom material, or on the flat surface of the polystyrene-based bottom material, whether there are wrinkles and there is no cloudiness in the laminated film. Was displayed as “good”, and wrinkles or cloudiness was displayed as “bad”.

(14) separating the gas barrier layer from the laminate,
Method for determining the resin composition ratio Fold the laminate into a glass container with a large glass stopper, put it together with a small amount of xylene solution, and leave it at room temperature for half a day. The laminate is composed of outer layer / adhesive layer / gas barrier layer. / Adhesive layer /
When it was an inner layer, it was separated into three layers: an outer layer with an adhesive layer, a gas barrier layer composed of the raw material composition for oxygen gas barrier laminate, and an inner layer with an adhesive layer. The gas barrier layer was taken out of this, and dried using a forced air gear oven at a temperature of 60 ° C. for 1 day to evaporate xylene. A certain amount of the obtained gas barrier layer (raw material composition for oxygen gas barrier laminate) was put in trichlorobenzene at 135 ° C. to dissolve the acid-modified styrene copolymer elastomer, and then precisely weighed 100 mesh stainless steel. It was filtered through a wire net to obtain an insoluble EVOH resin which remained on the wire net. The insoluble EVOH resin was dried using a forced air gear oven at a temperature of 60 ° C. for 1 day to evaporate trichlorobenzene, and then the weight of the EVOH resin was precisely weighed. The density of the EVOH resin thus obtained was calculated based on the method described in (8) above, and the density of the EVOH resin was converted into a volume. Remaining EVO
The H resin was used as a sample for measuring (11) ethylene content and (12) saponification degree.

A solution of trichlorobenzene in which the acid-modified styrene copolymer elastomer is dissolved is poured into a large amount of methyl alcohol, which is a poor solvent for the elastomer, to precipitate the elastomer, and the precipitate is collected and redissolved in trichlorobenzene. Pour into alcohol, re-precipitate, collect this re-precipitation, and use a forced air gear oven to
It was dried at ℃ for 1 day, methyl alcohol was evaporated, and the weight of the acid-modified styrene copolymer elastomer was precisely weighed. The precision-measured value of the thus obtained acid-modified styrene copolymer elastomer was used to calculate the density of the elastomer based on the method described in (8) above, and this density was converted to volume.
The remaining acid-modified styrene copolymer elastomer was used as a sample for measuring (10) acid value.

(15) Dispersed State in Molded Article The raw material resin is melt-kneaded with an extruder to remove the oxygen gas barrier layer peeled from the pellet or laminate produced by the above method (14) in an epoxy resin in a gelatin capsule. The specimen embedded in was sliced with a microtome, appropriately stained if necessary, and observed with a transmission electron microscope. The dispersion form that appears as shown in FIG. 1 is displayed as “with unique dispersion form”, and the dispersion form that does not appear as in FIG. 1 is displayed as “without unique dispersion form”.

[Example 1] <Raw material resin, mixture> (E) component is ^TM EV manufactured by Kuraray Co., Ltd.
AL # EP-G156 (ethylene content 47 mol%, saponification degree 98%, density 1.13 g / cm ³ , refractive index 1.51)
25) and the (S) component is ^TM TU manufactured by Asahi Kasei
FTEC # MX-007 {styrene content 30% by weight,
Acid value 10 (mgCH ₃ ONa / g), density 0.92g
/ Cm ³ , a refractive index of 1.5102} is prepared,
Density conversion of these resins is carried out, and resin composition ratio {(E) component} / {(S) component} = 65/35 (volume%)
Weighed. Both weighed components were dry blended with a drum tumbler, charged into a hopper of an extruder, and pelletized. The extruder used at this time had a diameter of 40 mm and L / D =
It is a Maddock type single screw type used for kneading No. 24. The melt viscosity ratio of both resins during kneading corresponds to 2.0,
The conditions of kneading temperature of 210 ° C. and screw rotation speed of 50 rpm were adopted. With respect to this pellet, the dispersed state in the pellet was observed by the method described in (15) above, and it was confirmed that the pellet had a unique dispersed form.

<Production of laminated body>
It is melted by an extruder equipped with a 0 mm full flight type screw, and a co-extrusion circular die is used to prepare a laminate of 5 layers, including 1 layer of a gas barrier layer made of the above resin composition, by the following method. Manufactured. At this time, the melting temperature of the raw material composition for oxygen gas barrier laminate in the extruder is 230 ° C. and the screw rotation speed is 36 rpm, so that the melt viscosity ratio in the die lip portion [= {(E) component} / {(S)) Ingredient}] was 2.0. The composition of the laminate is outer layer / adhesive / gas barrier layer / adhesive / inner layer. The outer layer acts as an elastic recovery assisting layer, and the material is M
It is a polypropylene elastomer with FR = 3 g / 10 min (230 ° C.) and is a trade name “soft polymer SPX” manufactured by Mitsubishi Chemical Corporation. The inner layer acts as a sealing layer,
The material is ethylene-methacrylic acid copolymer resin ^TM Nucrel {MFR = 3.3g /
10 minutes (190 ° C)}. For the adhesive, ^TM MODIC # P-330M manufactured by Mitsubishi Chemical Co., Ltd. {MFR = 12 g / 1
0 minutes (230 ° C)}.

The above resin was melt-laminated in a circular die and rapidly cooled to obtain a parison. From this parison, the gas barrier layer was peeled off, and the dispersion state was observed by the method described in (15) above, and it was confirmed that the dispersion state was unique. FIG. 1 is a photograph of a cross section of the gas barrier layer taken in the direction orthogonal to the molding direction at this time.
It is a transmission electron microscope photograph of a double magnification. This parison was formed into a film with a blow-up ratio = 3 and a draft ratio = 3 by a direct inflation method, folded with a pinch roll and wound into a roll. The thickness of each layer of the film of the obtained laminate was as follows: outer layer (40 μm) / adhesive (5 μm) / gas barrier layer (30 μm) / adhesive (5
μm) / inner layer (40 μm) (total 120 μm).

<Physical Properties of Laminated Product> Table 2 shows the measurement results of various physical properties of the obtained laminated product. Regarding the obtained laminate, (1) oxygen permeability was 39 (cm ³ / m ² /
24h / atm), low (3) Haze value of 16%, (E)
It has the same transparency as the component itself (Comparative Example 1, 15%),
(7) Since it has no brittle fracture, it has excellent low-temperature impact resistance, and (4) it has a tensile elastic modulus of 342 (MPa) and is soft, thus achieving the object of the present invention. Furthermore, (13) When packaged in a skin pack, the elastic recovery rate of the laminate film brought close contact with the object to be packaged, and a package excellent in wrinkle-free appearance was obtained. Further, the resin composition ratio is calculated based on the method described in (14) above, and the acid value of the component (S), (E) is calculated according to the method described in (10), (11) and (12) above. ) The ethylene content in the component and the degree of saponification were measured. All of these values are within the range specified in the raw material composition for an oxygen gas barrier laminate according to the first aspect of the present invention, the composition ratio of the dry-blended resin composition melt-kneaded by an extruder, and the raw material. It was confirmed that the error was within 3% with respect to the physical properties of the resin.

Example 2 <Raw material resin, mixing> In the example described in Example 1,
The (E) component is ^TM EVAL # EP-E15 manufactured by Kuraray Co., Ltd.
3 (ethylene content 44 mol%, saponification degree 98%, density 1.14 g / cm ³ , refractive index 1.5220),
(S) component was not changed, the resin composition ratio was changed to 67/33 (volume%), and the above pellets were melted by an extruder equipped with a kneading type Maddock type screw having a diameter of 50 mm. Same as in the example. <Manufacture of Laminated Body> The same procedure as in the example described in Example 1 was followed. However, the thickness of the gas barrier layer was 24 μm, the thickness of the laminate was 114 μm, the screw rotation speed of the extruder for extruding the raw material composition for oxygen gas barrier laminate was 22 rpm, and the melt viscosity ratio in the die lip portion was [= {(E) component} / {(S) component}] is 3.5
Met.

<Physical Properties of Laminate> Table 2 shows the results of measuring various physical properties of the obtained laminate. (1) Oxygen permeability of the resulting laminate ^{16 (cm 3 / m 2 /} 24h /
Atm), (3) Haze value is 16%, excellent transparency, (7) Low temperature impact resistance due to no brittle fracture, and (4) Tensile modulus = 330. (MPa), the object of the present invention has been achieved. In addition, (1
3) When packaged in a skin pack, due to the elastic recovery rate of the laminate film, a package that adheres closely to the product to be packaged and has an excellent appearance without wrinkles was obtained. In the methods described in (10), (11), and (12) above, the acid value of the component (S), the ethylene content of the component (E), and the measured saponification value are all the values of the first aspect of the present invention. Within the range specified by the raw material composition for an oxygen gas barrier laminate according to, the composition ratio of the dry-blended resin composition melt-kneaded by an extruder and the physical property value of the raw material resin are within 3% Was confirmed.

Example 3 <Raw Material Resin, Mixing> In the example described in Example 1,
Component (E) is ^TM EVAL # ES-G11 manufactured by Kuraray Co., Ltd.
0A (ethylene content 47 mol%, saponification degree 98%, density 1.12 g / cm ³ , refractive index 1.5083),
The same procedure was performed as in the example except that the resin composition ratio was changed to 50/50 (volume%) without changing the component (S). <Manufacture of Laminated Body> The same procedure as in the example described in Example 1 was followed. However, the thickness of the gas barrier layer was 44 μm, the thickness of the laminate was 134 μm, the screw rotation speed of the extruder for extruding the raw material composition for oxygen gas barrier laminate was 22 rpm, and the melt viscosity ratio in the die lip portion was [= {(E) component} / {(S) component}] is 1.0
Met.

<Physical Properties of Laminated Product> Table 2 shows the results of measuring various physical properties of the obtained laminated product. The oxygen permeability of the obtained laminate (1) was 150 (cm ³ / m ² / 24h).
/ Atm), (3) haze value of 15%, excellent transparency, (7) excellent low-temperature impact resistance due to no brittle fracture, and (4) tensile modulus = 250 (MPa), the object of the present invention has been achieved. Furthermore, (13)
When packaged in a skin pack, due to the elastic recovery rate of the laminate film, a package that adheres closely to the object to be packaged and has an excellent appearance without wrinkles was obtained. By the method described in (10), (11) and (12) above, the acid value of the component (S), the ethylene content of the component (E),
And the measured values of the saponification degree are both within the range specified in the raw material composition for an oxygen gas barrier laminate according to the first aspect of the present invention, and the composition ratio of the dry-blended resin composition melt-kneaded by an extruder is used. It was confirmed that the error was within 3% with respect to the physical properties of the raw material resin.

[Example 4] <Raw material resin, mixing> In the example described in Example 3,
The (E) component and the (S) component are not changed, and only the resin composition ratio is
The same as in the same example except that the ratio was changed to 60/40 (volume%). <Manufacture of Laminated Body> The same procedure as in the example described in Example 3 was followed. However, the thickness of the gas barrier layer was 30 μm, and the thickness of the laminate was 120 μm.

<Physical Properties of Laminated Product> Table 2 shows the results of measuring various physical properties of the obtained laminated product. (1) Oxygen permeability of the resulting laminate ^{49 (cm 3 / m 2 /} 24h /
Atm), (3) Haze value is 16%, it has excellent transparency, (7) It has excellent low-temperature impact resistance because it has no brittle fracture,
And (4) Tensile elastic modulus = 322 (MPa), which is soft,
The objects of the invention have been achieved. Furthermore, (13) When packaged in a skin pack, the elastic recovery rate of the laminate film brought close contact with the object to be packaged, and a package excellent in wrinkle-free appearance was obtained. By the method described in (10), (11) and (12) above,
The acid value of the component (S), the ethylene content of the component (E), and the measured value of the degree of saponification are all within the ranges specified in the raw material composition for an oxygen gas barrier laminate according to the first aspect of the present invention. It was confirmed that the error was within 3% with respect to the composition ratio of the dry-blended resin composition melt-kneaded by the extruder and the physical property value of the raw material resin.

[Example 5] <Raw material resin, mixing> In the example described in Example 3,
The (E) component and the (S) component are not changed, and only the resin composition ratio is
The procedure was the same as in the example except that the ratio was changed to 52/48 (volume%). <Manufacture of Laminated Body> The same procedure as in the example described in Example 1 was followed. However, the thickness of the gas barrier layer was 30 μm, and the thickness of the laminate was 120 μm.

<Physical Properties of Laminated Product> Table 2 shows the results of measuring various physical properties of the obtained laminated product. The resulting (1) oxygen permeability of the laminate ^{50 (cm 3 / m 2 /} 24h /
Atm), (3) Haze value is 16%, it has excellent transparency, (7) It has excellent low-temperature impact resistance because it has no brittle fracture,
And, (4) Tensile modulus = 233 (MPa), which is soft,
The objects of the invention have been achieved. Furthermore, when skin pack packaging was carried out by a conventional method, due to the elastic recovery rate of the laminate film, a package which was in close contact with the article to be packaged and had an excellent appearance without wrinkles was obtained. By the method described in (10), (11) and (12) above,
The acid value of the component (S), the ethylene content of the component (E), and the measured value of the degree of saponification were all within the ranges specified in the first aspect of the present invention, and were dry-blended by melt-kneading with an extruder. It was confirmed that the error was within 3% with respect to the composition ratio of the resin composition and the physical property value of the raw material resin.

[Example 6] <Raw material resin, mixing> The same as the example described in Example 1. <Manufacture of Laminated Body> In the example described in Example 1, the inner layer having a sealing property is ethylene-α-olefin (α-) which is linear low-density polyethylene (also called linear low-density polyethylene or VLDPE). The olefin was octene-1, and the content thereof was 18% by weight. A laminate was produced by the same procedure as in the same example except that the copolymer was used. <Physical Properties of Laminated Body> (13) When packaged in a skin pack, the elastic recovery rate of the laminated body film provides a packaged product that is in close contact with the product to be packaged and has an excellent appearance without wrinkles. This example shows that the skin pack wrapping property is excellent even if the resin of the inner layer is changed.

[Example 7] <Raw material resin, mixing> The same procedure as in Example 1 was carried out. <Manufacture of Laminated Body> In the example described in Example 1, the die was changed to co-extrusion to a T-die, melt-laminated in the T-die, quenched and drawn, and composed of 5 layers without stretching operation. A sheet of a laminate was obtained, and the thickness of each layer of the sheet was as follows: outer layer (190 μm) / adhesive layer (20 μm) / gas barrier layer (60 μm) / adhesive (20 μm) / inner layer (190 μm)
m) (total 480 μm), but the same as in the same example. <Physical Properties of Laminated Body> Table 2 shows the measurement results of various physical properties of the obtained laminated body. Obtained the laminate (1) Oxygen permeability is ^{32 (cm 3 / m 2 /} 24h / at
m), lower (3) haze value of 18%, transparency that can be used, (7) excellent low-temperature impact resistance due to no brittle fracture, and (4) tensile modulus = 240. (MPa)
And the object of the present invention is achieved.

Comparative Example 1 <Raw material resin> In the example described in Example 3, only the component (E) was used and the component (S) was not used. <Manufacture of Laminated Body> The same procedure as in the example described in Example 1 was followed. However, the thickness of the component (E) layer was 28 μm, and the thickness of the laminate was 118 μm. <Physical Properties of Laminated Body> Table 2 shows the measurement results of various physical properties of the obtained laminated body. (1) of the obtained laminate
The oxygen permeability is 8 (cm ³ / m ² / 24h / atm), and the laminate including the layer of the component (E) itself has an excellent oxygen gas barrier property. (3) The haze value is 15% and the transparency is excellent. Have sex. However, (7) brittle fracture causes inferior low-temperature impact resistance, and (4) tensile modulus = 540 (MPa), which is too hard to achieve the object of the present invention. Furthermore, (13) when packaged in a skin pack, the surface of the article to be packaged has wrinkles,
A package having an excellent appearance could not be obtained. Also, as described above, the low temperature impact resistance is poor.

[Comparative Example 2] <Raw material resin, mixture> (E) component is ^TM EV manufactured by Kuraray Co., Ltd.
AL # ES-G110A (ethylene content rate 47 mol%,
Saponification degree 98%, density 1.12 g / cm ³ , refractive index 1.5
083), and, (S) component, Asahi Chemical Industry Co. ^TM T
UFTEC # M-1943 {styrene content of 20 wt%, acid number _{10 (mgCH 3 ONa / g)} , density 0.9
A raw material having 0 g / cm ³ and a refractive index of 1.5001} was prepared, and the density of these resins was converted into a resin composition ratio = 88 /
It was weighed as 21 (volume%). Melt kneading and pelletization by the extruder were performed in the same manner as in Example 1. With respect to this pellet, the dispersed state in the pellet was observed by the method described in (15) above, but no specific dispersed form was observed.

<Manufacture of Laminated Body> A procedure similar to the example described in Example 1 was followed. However, the thickness of the (E) component layer is 30
μm, and the thickness of the laminated body was 120 μm. <Physical Properties of Laminated Body> Table 2 shows the measurement results of various physical properties of the obtained laminated body. (1) of the obtained laminate
Oxygen permeability ^{39 (cm 3 / m 2 /} 24h / atm) in the oxygen gas barrier property is superior, and inferior in low-temperature impact resistance because there is (7) brittle fracture. Furthermore, (3) haze value is 30% and transparency is poor, and (4) tensile modulus = 49
The hardness is 0 (MPa) and the object of the present invention is not achieved. Furthermore, (13) When the product was packaged in a skin pack, the surface of the article to be packaged was wrinkled, and a package having an excellent appearance could not be obtained.

[Comparative Example 3] <Raw material resin, mixing> In the example described in Comparative Example 2,
(E) component is unchanged, and (S) component is ^TM manufactured by Asahi Kasei Kogyo Co., Ltd.
TUFTEC # H-1031 {styrene content 30% by weight, unmodified, acid value not measured, density 0.91 g /
cm ³ and refractive index of 1.5131}, except that Comparative Example 2
Same as in. <Manufacture of Laminated Body> The same procedure as in the example described in Example 1 was followed. However, the thickness of the component (E) layer was 30 μm, and the thickness of the laminate was 120 μm.

<Physical Properties of Laminated Product> Table 2 shows the results of measuring various physical properties of the obtained laminated product. The resulting (1) oxygen permeability of the laminate ^{17880 (cm 3 / m 2/} 2
4h / atm), the oxygen gas barrier property is extremely poor. It should be noted that since (7) there is no brittle fracture, it has excellent low temperature impact resistance. However, (3) the haze value is 20%, the transparency is poor, and (4) the tensile modulus = 72 (MPa) is too soft, and the object of the present invention cannot be achieved. Further, (13) when packaged in a skin pack, the laminate was opaque due to heat stretching of the laminate during the skin pack process, and a package having an excellent appearance could not be obtained.

[Comparative Example 4] <Raw material resin, mixing> In the example described in Example 3,
The (E) component and the (S) component are not changed, and only the resin composition ratio is
The same as in the same example except that it was changed to 45/55 (volume%). <Manufacture of Laminated Body> The same procedure as in the example described in Example 1 was followed. However, the thickness of the gas barrier layer was 15 μm, and the thickness of the laminate was 105 μm. <Physical Properties of Laminated Body> Table 2 shows the measurement results of various physical properties of the obtained laminated body. (1) of the obtained laminate
Oxygen permeability is 22000 (cm ³ / m ² / 24h / at
m), the oxygen gas barrier property is extremely poor. (7) It has excellent low-temperature impact resistance because it has no brittle fracture. But,
(3) The haze value is 18% and the transparency is poor, and (4) the tensile elastic modulus is 64 (MPa), which is too soft and the object of the present invention cannot be achieved.

[0075]

[Table 2]

[0076]

[Table 3]

From the results of Examples and Comparative Examples and the results of Experimental Examples, FIG. 1, FIG. 2 and FIG. 1. From FIG. 1, in the raw material composition for an oxygen gas barrier laminate according to the present invention, the component (E) and the component (S) are dispersed in a unique dispersion form, and this dispersion form is formed into a molded article. It has excellent physical properties. 2. From FIG. 2, the raw material composition for an oxygen gas barrier laminate containing the component (E) and the component (S) used for the laminate was
When the content of the (S) component exceeds 50% by volume, the oxygen gas barrier property of the molded article deteriorates, and when the (S) component is less than 32% by volume, it is not sufficiently soft enough to be skin-packed (sealed). 3. From FIG. 3, it can be said that the laminated film obtained from the raw material composition for an oxygen gas barrier laminate according to the present invention is excellent in both tensile elastic modulus and oxygen permeability, and that these physical properties are well balanced. 4. The laminated film obtained from the raw material composition for an oxygen gas barrier laminate according to the present invention has (1) an oxygen permeability of 15
As low as ~ 150 (cm ³ / m ² / 24h / atm),
(3) Haze value is 16%, it has excellent transparency, (7) It is excellent in low-temperature impact resistance because it has no brittle fracture, and (4) Tensile modulus = 233 to 342 (MPa). It is soft and the object of the invention is achieved. 5. Furthermore, (13) When packaged in a skin pack, the elastic recovery rate of the laminate film makes it possible to obtain a package which is in close contact with the article to be packaged and has an excellent appearance without wrinkles.

[0078]

INDUSTRIAL APPLICABILITY The present invention has the following special advantageous effects and its industrial utility value is extremely large. 1. The raw material composition for an oxygen gas barrier laminate according to the first aspect of the present invention has an ethylene content of the component (E), an acid value of the component (S), and a volume ratio of the component (E) and the component (S). Since the specific range is used, the tensile elasticity can be appropriately reduced while maintaining the oxygen gas barrier property and the transparency. 2. The oxygen gas barrier laminate according to the second aspect of the present invention is
When packaged in a skin pack, due to the elastic recovery rate of the laminate film, a package that adheres closely to the object to be packaged and has an excellent appearance without wrinkles can be obtained. 3. The oxygen gas barrier laminate according to the second aspect of the present invention is
Since the elastic recovery rate is within the appropriate range, a skin pack package having a good appearance as a product can be obtained. 4. Since the raw material composition for an oxygen gas barrier laminate according to the first aspect of the present invention and the oxygen gas barrier laminate according to the second aspect of the present invention do not contain a halide, there is no problem of polluting the environment. . 5. According to the method for producing a raw material composition for an oxygen gas barrier laminate according to the third aspect of the present invention, the component (E) and the component (S) can be dispersed in a specific dispersion form.

[Brief description of drawings]

1 is a micrograph (drawing substitute photograph) of a cross section of a molded product of the resin composition obtained in Example 1. FIG.

[Fig. 2] Mixing ratio of component (E) and component (S) (horizontal axis)
And the oxygen permeability and the tensile elastic modulus (vertical axis) are represented by a diagram.

[Fig. 3] Tensile elastic modulus (horizontal axis) and oxygen permeability (vertical axis)
It is a diagram showing the relationship with.

Claims (3)

[Claims] 1. A raw material composition for an oxygen gas barrier laminate, comprising a saponified ethylene-vinyl acetate copolymer {(E) component} and an acid-modified styrene copolymer elastomer {(S) component}, Component (E) has an ethylene content of 3
0 to 50 mol% and a saponification degree of 90% or more, and the component (S) has an acid value of 1 to 20 (mgCH ₃ O
Na / g) and the ratio of the (E) component to the (S) component is 68/32 (volume%) to 50/5.
A raw material composition for an oxygen gas barrier laminate, which is in the range of 0 (volume%). 2. An oxygen gas barrier laminate having at least one layer comprising the raw material composition according to claim 1, wherein the laminate has a tensile elastic recovery rate in the range of 50 to 99% and a tensile elasticity. An oxygen gas barrier laminate having a rate of 100 to 400 MPa. 3. The laminated body according to claim 2, wherein the parameter value [tensile elastic modulus (MPa) of laminated body / elastic recovery rate (%) of laminated body] is in the range of 1.5 to 5.5. An oxygen gas barrier laminate, which is a film or a sheet.