JPH10329272A - Multilayer film of allyl alcohol polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a laminated film having excellent effects in gas barrier properties, bag making machinability, drop strength, external appearance and melting moldability in the conditons of low and high humidity. SOLUTION: This film is prepared by a method wherein a film of at least one kind of thermoplastic resin (B) selected from the group of polyolefin, polyamide, polyester, polycarbonate, polystyrene, polyvinyl chloride and polyurethane is laminated on one or both surfaces of a film of a thickness 0.05-50 μm constituted of allyl alcohol polymer resin (A) containing a repeated structural unit shown by the formula by 30 mol.% or more, and the amount of oxygen permeation at the relative humidity 65% is 30 ml/m<2> .day.atm or less. In the formula, R<1> denote a 1-2C alkyl group and R<2> a hydrogen atom or a 1-3C alkyl group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer film excellent in gas barrier properties, melt moldability, bag making properties, drop strength and appearance.

[0002]

2. Description of the Related Art At present, a gas barrier material made of a resin having particularly excellent performance of blocking gas such as oxygen (gas barrier property) is provided by:
It is widely used mainly in the field of packaging materials containing foods and pharmaceuticals. Such resin materials having particularly excellent gas barrier properties include a vinyl alcohol polymer represented by an ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as EVOH) and a vinylidene chloride polymer (hereinafter abbreviated as PVDC). Acrylonitrile-based polymer (hereinafter sometimes abbreviated as PAN) and the like.

[0003] EVOH has high gas barrier properties under low humidity, and can be melt-molded, especially co-extruded with polyolefin or the like. However, there is a drawback that the gas barrier property is deteriorated under high humidity, so that there is a limitation in use and use form. For example, EVOH is often used as the innermost layer in fields where fragrance retention is important, such as juice containers.
Since the barrier property under high humidity is insufficient, it is necessary to use the EVOH layer also for the intermediate layer, which increases the cost. In addition, it has a disadvantage of lacking water vapor barrier properties, and therefore, in many applications, it has to be used as a multilayer body with a material having relatively good water vapor barrier properties, such as polyolefin such as polypropylene and polyethylene. When higher water vapor barrier properties are required, it may be difficult to use.

[0004] Unlike EVOH, PVDC has a small humidity dependence of gas barrier properties, so that it exhibits high gas barrier properties even under high humidity and has good water vapor barrier properties. But,
Since the thermal stability is very poor, it is necessary to copolymerize with vinyl chloride or the like or to add a plasticizer in order to perform melt molding. However, such a melt-moldable PVDC copolymer is generally inferior to EVOH in gas barrier properties. Therefore, in fields where high gas barrier properties are required, PVDC in which the copolymerization or addition of a plasticizer is refrained may be carried out by an emulsion coating method or the like. It is used after being coated on a film or the like by a solution coating method. However, since the thickness of the barrier layer is limited by these methods, it is difficult to adapt to a field where high gas barrier properties are required.

[0005] Although PAN homopolymer has excellent gas barrier properties, it has a very high melting point, and is difficult to melt-mold. Melt-moldable copolymers are generally EVOH
Inferior to gas barrier properties.

Also, EVOH, PVDC and PAN
All have a problem that when the thickness is increased, the transparency is deteriorated and the film becomes cloudy. In addition, PVDC and PAN have a problem that they are colored yellow by light or heat during melt molding. It is known that these problems can be alleviated by copolymerization.However, since gas barrier properties are also deteriorated, the gas barrier properties are excellent even under high humidity, and the transparency and melt moldability are also excellent. The development of a gas barrier material has long been desired and has continued to this day.

On the other hand, polymers comprising allyl alcohols represented by polyallyl alcohol, polymethallyl alcohol and the like as recurring structural units are known, and are disclosed in US Pat. Nos. 2,455,722, 2,467,105 and 3,673.
Nos. 285897 and 3666740 (Japanese Patent Publication No. 47-4)
0308), No. 4,125,694, British Patent No. 8542
No. 07 has been filed for a polymerization method.

Some of the applications relating to these polymerization methods include:
Although the use of the allyl alcohol-based polymer is also described, there is no description that such a polymer has an extremely good gas barrier property. For example, U.S. Pat. No. 4,125,694 describes "coating agents, adhesives, anti-smearing agents, molding powders, paints, lacquers, laminates, fillers, dispersants, resin product intermediates (coatin).
g agents, adhesives, impregnants, molding powders,
paints, varnishes, laminates, fillers, in dispers
ions, and as intermediate in resin production) "
However, there is no description of use for applications requiring high gas barrier properties. Further, among the allyl alcohol-based polymers, polyallyl alcohol, which is the most typical polymer, does not achieve the object of the present invention, and R ¹ in the formula (1) in the claims of the present application is not a hydrogen atom but a specific alkyl group. There is no description or suggestion that the object of the present invention is achieved only when.

Also, Japanese Patent Application Laid-Open No. Hei 8-5080065 (W)
O95 / 12624) describes the use of a polymer having a vinyl alcohol-based or allyl alcohol-based monomer as a structural unit as a packaging material having an oxygen permeability at a high humidity of a specific value or less. However, as the allyl alcohol-based polymer, it is an essential requirement that R ¹ in the formula (1) in the present application be a hydrogen atom, and R ¹ is not a hydrogen atom but a specific alkyl group. Is not described at all. Further, it is said that it is more preferable to use a vinyl alcohol unit in place of the allyl alcohol unit. In Examples, a part of the hydroxyl group of EVOH is acylated with an aromatic carboxylic acid, so that it can be used under high humidity. Only the example of improving the oxygen barrier property of the present invention is described, and the means for solving the problem is completely different from the present invention.

[0010] Further, Polymer Bulletin, 3 (10), pp 5
In literatures such as 21-528 and 1980, there is a description of polymethallyl alcohol whose steric structure is regulated to isotactic or syndiotactic, but there is no description or suggestion of gas barrier properties.

[0011]

The inventors of the present invention have examined the applicability of the allyl alcohol-based polymer resin to applications such as packaging materials requiring a high gas barrier property. It has excellent gas barrier properties compared to resins, and is particularly excellent in gas barrier properties under high humidity, and has good transparency, low moisture permeability, and is useful as a material for packaging films and the like. It was found to have properties.

However, when such an allyl alcohol-based polymer resin is used as a single layer in a packaging film,
It was found that bag formability and drop strength were poor. Thus, the present invention provides a gas barrier property of the conventionally known gas barrier thermoplastic resin, particularly a gas barrier property under high humidity,
Improves melt moldability and transparency, and solves the technical problems related to bag making processability and drop strength of the allyl alcohol-based polymer resin itself, and is used for applications such as packaging materials that require advanced gas barrier properties. It is intended to obtain a suitable and excellent multilayer film.

[0013]

The object of the present invention is to provide an allyl alcohol-based polymer resin (A) containing at least 30 mol% of a repeating structural unit represented by the following formula (1) and having a thickness of 0.5 to 50 μm. At least one thermoplastic resin (B) selected from the group consisting of polyolefin, polyamide, polyester, polycarbonate, polystyrene, polyvinyl chloride and polyurethane on one or both sides of the film
This is achieved by providing a multilayer film having a film thickness of not more than 30 ml / m ² · day · atm at 20 ° C. and a relative humidity of 65%.

Embedded image (In the formula, R ¹ represents an alkyl group having 1 to ² carbon atoms, and R ² represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.)

At this time, the glass transition point of the resin (A) at the time of absolute drying is 45 to 95 ° C .;
A glass transition point of not less than 20 ° C. when the condition is adjusted at 85% RH, or 20 ° C. of the resin (A);
Preferably, the saturated moisture absorption at 65% RH is 0.5 to 15% by weight. The resin (A) has a water vapor permeability at 30 ° C. and 90% relative humidity of 30 g · 30 μm / m ² ···
day or less, and the oxygen permeability of the resin (A) at 20 ° C. and a relative humidity of 100% is 30 ml · 20 μm / m
It is also preferable that it be ² * day * atm or less. Further, it is preferable that R ¹ in the formula (1) is CH ₃ and R ² is H. Further, a packaging container comprising these multilayer films is a preferred embodiment of the present invention.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The allyl alcohol copolymer resin (A) used in the multilayer film of the present invention comprises a resin containing at least 30 mol% of a repeating structural unit represented by the following formula (1). is there.

[0016]

Embedded image

(In the formula, R ¹ represents an alkyl group having 1 to ² carbon atoms, and R ² represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.)

R ¹ represents a substituent selected from a methyl group and an ethyl group. Of these, a methyl group is most preferable from the viewpoint of gas barrier properties. R ² represents a hydrogen atom, a substituent selected from a methyl group, an ethyl group, a propyl group, and an isopropyl group, and among these, a hydrogen atom is optimal from the viewpoint of gas barrier properties. When the carbon number of these substituents exceeds the above-mentioned value, the glass transition point is lowered, the gas barrier property is reduced, and the stiffness is reduced, so that the bag-making processability is deteriorated.

The content of the above structural unit in the resin (A) is 3
It is necessary to be 0 mol% or more, and the range of 45 to 100 mol% is more preferable. More preferably, it is 70 to 100 mol%, and the range of 80 to 100 mol% is optimal. When the content of the structural unit is below the above range, the gas barrier properties, bag-making processability and appearance are inferior. Also, R ¹ and / or
Alternatively, two or more types of the above structural units having different R ² may be contained. In this case, the content of the structural unit in the resin is the total thereof.

The copolymer components other than the above structural units include:
There is no particular limitation as long as the performance is not adversely affected.
Specific examples of the copolymer component include ethylene, propylene,
Olefins such as 1-butene, isobutene, 1-pentene, 1-hexene, 1-octene, diene monomers such as butadiene and isoprene, and aromatic-substituted vinyl monomers such as styrene and α-methylstyrene. Monomers, methyl acrylate, ethyl acrylate, butyl acrylate, acrylic monomers such as methyl methacrylate, methyl vinyl ether, ethyl vinyl ether, vinyl ether monomers such as butyl vinyl ether, vinyl chloride,
Vinyl halide monomers such as vinyl fluoride, vinylidene chloride, vinylidene halide monomers such as vinylidene fluoride, acrylonitrile, acrylonitrile monomers such as methacrylonitrile, maleimide, N-methylmaleimide, And maleic acid derivative monomers such as dimethyl maleate.

When a copolymer component is contained, the copolymerization method may be either random copolymerization or alternating copolymerization. However, when the copolymer component is large (the copolymer component is about 30%).
(Mole% or more) preferably has high alternating copolymerizability from the viewpoint of gas barrier properties and bag making processability. When the alternating copolymerizability is high, the content of the structural unit represented by the formula (1) is 45.
It is preferably in the range of ~ 60 mol%.

The stereoregularity of the resin (A) is not particularly limited, but is preferably regulated by syndiotactic or isotactic because gas barrier properties are further improved. In this case, it is preferable that the content be controlled to be syndiotactic or isotactic in a triad display of 60 mol% or more. More preferably, it is preferably regulated to 80 mol% or more. However, in general, it is not easy to manufacture a resin with restricted stereoregularity or the cost is increased. Therefore, it is preferable to use a resin different from an atactic resin depending on the application.

The intrinsic viscosity of the resin (A) used in the present invention is preferably in the range of 0.1 to 3 dl / g as measured in metacresol at 30 ° C., and is preferably in the range of 0.2 to 2 dl / g.
dl / g is more preferable, and 0.3 dl / g to 1. dl / g.
The range of 5 dl / g is most preferred. If the intrinsic viscosity is too low, sufficient drop strength cannot be obtained. On the other hand, if the intrinsic viscosity is too high, gel and fish eyes are generated during the film formation of the film, and the appearance of the film deteriorates.

As a method of adjusting the intrinsic viscosity of the resin (A) to the above range, in addition to the method of adjusting the degree of polymerization of the resin,
A method of copolymerizing a silicon-containing olefinic unsaturated monomer such as vinylmethoxysilane described in JP-A-60-144304 or the like, if necessary, can be exemplified.

The resin (A) used in the present invention has a glass transition point of 45 to 95 ° C., preferably 50 to 90 ° C., at the time of absolute drying.
C., more preferably 55-85 ° C., from the viewpoint of improving bag making workability and drop strength. If the glass transition point is lower than the above range, the bag-making processability is poor, and if the glass transition point is higher than the above range, the drop strength is poor.

The glass transition point of the resin (A) at a temperature controlled at 20 ° C. and 85% RH is set at 20 ° C. or higher, preferably 25 ° C. or higher, more preferably 30 ° C. or higher. It is preferable for improving the gas barrier property under the above.

Further, at a temperature of 20 ° C. and 65% RH of the resin (A),
Is 0.5 to 15% by weight, preferably 1.0 to 10% by weight, and more preferably 1.5 to 6% by weight.
Setting to is good for improving the drop strength. If the saturated moisture absorption is below the above range, the drop strength is poor, and if the saturated moisture absorption is above the range, the bag-making processability and the gas barrier properties are poor.

As a method for adjusting the glass transition point and / or the saturated moisture absorption of the resin (A) to the above-mentioned range, a method of appropriately selecting R ¹ and R ² of the resin, a method of adjusting the stereoregularity of the resin, Examples thereof include a method by copolymerization with a copolymerizable comonomer and a method of adjusting random copolymerizability / alternate copolymerizability in the case of copolymerization. By appropriately combining these, the glass transition point can be easily adjusted.

The resin (A) of the present invention has a relative humidity of 1 ° C. at 20 ° C.
The oxygen permeability at 00% is 30 ml · 20 μm / m
It is preferably not more than ² · day · atm, more preferably not more than 20 ml · 20 μm / m ² · day · atm, and still more preferably 10 ml · 20 μm / m ^2.
・ Day ・ atm or less, optimally 5ml ・ 20μ
m / m ² · day · atm or less. 30ml ・ 20
When it is larger than μm / m ² · day · atm, it may not be used in applications used under high humidity.

The resin (A) has a relative humidity of 20 ° C. and a relative humidity of 65 ° C.
% Oxygen permeability is 10 ml · 20 μm / m ² · d
ay · atm or less, more preferably 5 ml · 20 μm / m ² · day · atm or less, and even more preferably 2 ml · 20 μm / m ² · day.
・ Atm or less, optimally 1 ml ・ 20 μm / m ²
· Day · atm or less.

Further, the resin (A) has a relative humidity of 40 ° C. and a temperature of 9 ° C.
The moisture permeability at 0% is 30 g · 30 μm / m ² · day
Or less, more preferably 20 g · 3
0 μm / m ² · day or less, and more preferably 1 μm / m ² · day.
0 g · 30 μm / m ² · day or less. 30g ・ 3
When it is larger than 0 μm / m ² · day, depending on the use, it is often necessary to use a layer composed of a resin made of a resin having a low moisture permeability such as polyolefin.

As a method for adjusting the oxygen permeability or the moisture permeability as described above, the resin (A) in the above formula (1)
Examples thereof include a method of appropriately selecting ¹ and R ² , a method of adjusting stereoregularity, a method of performing copolymerization, and a method of stretching and orienting the resin (A).

The resin (A) of the present invention shows good transparency. Specifically, the haze value (JIS K710) of a single-layer film having an arbitrary thickness composed of the resin (A) of the present invention is used.
5) is preferably 2% or less, more preferably 1.5% or less, and most preferably 1% or less. By having such a haze value, a multilayer film having excellent transparency can be obtained, and is suitably used as a container having good internal visibility.

The method for producing the resin (A) of the present invention includes:
There is no particular limitation, and various methods can be adopted, including the methods described in the related art. The main methods include the following production methods. First production method: produced by polymerizing a monomer represented by the following formula (2) and then reducing it.

[0035]

Embedded image

(Wherein R ¹ is a methyl group or an ethyl group,
X represents an alkoxyl group, a hydroxyl group, a halogen atom, a hydrogen atom, a methyl group, an ethyl group, a propyl group or an isopropyl group, respectively. )

Specific examples of the above monomers include acrylic acid derivatives such as methacrylic acid and 2-ethylacrylic acid; acrylic acid ester derivatives such as methyl methacrylate and methyl 2-ethylacrylate; methacrolein; Acrolein derivatives such as ethyl acrolein; vinyl ketone derivatives such as isopropenyl methyl ketone, isopropenyl ethyl ketone, isopropenyl propyl ketone, and isopropenyl isopropyl ketone.

The above monomers can be polymerized by known polymerization methods such as radical polymerization and anion polymerization. Examples of the radical polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4′-dimethylvaleronitrile), and 2,2′-azobis (4-methoxy-
Azo-based initiators such as 2,4'-dimethylvaleronitrile); and peroxide-based initiators such as isobutyl peroxide, di-n-propylperoxydicarbonate, and t-butylperoxypivalate. The polymerization temperature at this time is not particularly limited, and the polymerization is usually performed in a temperature range from room temperature to about 100 ° C. As the conditions for the anionic polymerization,
As an initiator, a basic alkali metal or alkaline earth metal derivative such as butyllithium, lithium aluminum hydride, methylmagnesium bromide, ethylmagnesium chloride, and triphenylmethylcalcium chloride is used as an initiator, and usually tetrahydrofuran, dimethoxyethane The polymerization is carried out at a low temperature of about -100 ° C. to room temperature using an aprotic solvent such as diethyl ether or the like as a solvent. Further, by appropriately selecting the above polymerization conditions, a polymer whose steric structure is restricted to isotactic or syndiotactic can be obtained. For example, when polymerization of methyl methacrylate is performed using triphenylmethyl calcium chloride, bis (pentamethylcyclopentadienyl) samarium methyl, or the like as an initiator, syndiotactically regulated polymethyl methacrylate is obtained, and hydrogen When methyl methacrylate is polymerized by using lithium aluminum chloride as an initiator, polymethyl methacrylate regulated in an isotactic manner is obtained.

As a method for reducing the obtained polymer, a method using a metal hydride such as lithium aluminum hydride, sodium borohydride, lithium borohydride, diborane or the like as a reducing agent, ruthenium-based, rhodium-based, nickel-based , Palladium-based and platinum-based transition metal catalysts. The reduction reaction solvent is appropriately selected in consideration of the solubility of the polymer and the reactivity with the reducing agent. Examples include tetrahydrofuran,
N-methylmorpholine, dimethylacetamide, dimethylformamide, dimethylsulfoxide, dimethoxyethane, methanol, ethanol, propanol and the like. The reduction reaction temperature is usually selected from the range of room temperature to 200 ° C, and the range of 50 ° C to 150 ° C is preferable.
In the case where a polymer whose steric structure is controlled to be isotactic or syndiotactic is reduced, a reduced polymer having a controlled steric structure is obtained.

Second production method: produced by polymerization of an allyl alcohol having a structure represented by the following formula (3).

[0041]

Embedded image

(In the formula, R ¹ represents an alkyl group having 1 to ² carbon atoms, and R ² represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.)

The method for polymerizing the above allyl alcohols is not particularly limited. For example, US Pat.
7, 3666740 (JP-B-47-40308) and British Patent 854207.

Third production method: It is obtained by chemically converting a halogen atom into a hydroxyl group after polymerization of an allyl halide derivative having a structure represented by the following formula (4).

[0045]

Embedded image

(Wherein, R ¹ is an alkyl group having 1 to 2 carbon atoms, R ² is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms,
X represents a halogen atom. )

The third production method is described, for example, in US Pat. No. 4,125,694.

The resin (A) of the present invention may be blended with another thermoplastic resin as long as its effect is not impaired. Examples of such a thermoplastic resin, polyethylene, polypropylene, polybutene, polyolefins such as polymethylpentene, polyethylene terephthalate, polyesters such as polybutylene terephthalate,
Polyamides such as polycaprolactam (6-nylon), polylauryl lactam (12-nylon), polyhexamethylene adipamide (6,6-nylon), polystyrene, polyvinyl chloride, polycarbonate, polymethyl methacrylate, polyurethane, etc. Is mentioned. The amount of the resin to be blended is usually in the range of 50% by weight or less.

The resin (A) of the present invention may contain various additives as necessary. Examples of such additives include antioxidants, plasticizers, heat stabilizers,
UV absorbers, antistatic agents, lubricants, coloring agents, fillers,
Alternatively, other polymer compounds can be mentioned, and these can be blended as long as the effects of the present invention are not inhibited. Specific examples of the additives include the following.

Antioxidants: 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-p-cresol, 4,4'-thiobis- (6-t-butylphenol), 2,2 '-Methylene-bis- (4-methyl-6-
t-butylphenol), octadecyl-3- (3 ′,
5'-di-t-butyl-4'-hydroxyphenyl) propionate, 4,4'-thiobis- (6-t-butylphenol) and the like.

UV absorber: ethylene-2-cyano-
3,3′-diphenyl acrylate, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole,
2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t-butyl-5 '-Methylphenyl) 5-
Chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone and the like.

Plasticizers: dimethyl phthalate, diethyl phthalate, dioctyl phthalate, wax, liquid paraffin, phosphate ester and the like. Antistatic agents: pentaerythritol monostearate, sorbitan monopalmitate, sulfated polyolefins,
Polyethylene oxide, carbowax, etc. Lubricants: ethylene bis stearoylamide, butyl stearate, metal salts of higher fatty acids, and the like. Colorants: carbon black, phthalocyanine, quinacridone, indoline, azo pigments, red iron, etc. Filler: glass fiber, asbestos, ballastonite, calcium silicate, mica, titanium oxide, calcium carbonate, silicon oxide, etc.

The thickness of the allyl alcohol polymer resin (A) used in the present invention must be set in the range of 0.5 to 50 μm. It is preferably set to 1 to 40 μm, more preferably 5 to 30 μm, and 7 to 25 μm.
It is optimal to set it to μm. If it falls below the range,
If sufficient bag-making processability and gas barrier properties cannot be obtained, and if the above range is exceeded, the bag-making processability is poor and the drop strength is also poor.

In the present invention, a film of at least one thermoplastic resin (B) selected from the group consisting of polyolefin, polyamide, polyester, polycarbonate, polystyrene, polyvinyl chloride and polyurethane is provided on one or both surfaces of the resin (A). Need to be laminated.

The thermoplastic resin (B) used in the multilayer film of the present invention includes polyolefins such as polyethylene, polypropylene, polybutene, polymethylpentene and ethylene-propylene copolymer, and polycaprolactam (6-
Nylon), polyamide such as polylauryl lactam (12-nylon), polyhexamethylene adipamide (6,6-nylon), polyester such as polyethylene terephthalate and polybutylene terephthalate, polystyrene (GPPS), high impact polystyrene (HIP)
S), styrene-butadiene copolymer (SB), styrene-butadiene-acrylonitrile copolymer (SBA)
And polystyrene, polyvinyl chloride, polycarbonate and polyurethane.

By laminating the resin (B) on the resin (A) according to the present invention, the bag-making workability and the drop strength are particularly improved. If the resin other than the resin (B) is laminated, the effects of the present invention cannot be sufficiently exhibited. Among the resins (B), polyolefins, polyamides, polyesters and polystyrenes are preferable in that the effects of the present invention are sufficiently exhibited, and among them, polyolefins, polyamides and polyesters are most preferable.

In the first embodiment of the present invention, the resin (A)
And a film of at least one thermoplastic resin (B) selected from the group consisting of polyolefin, polyamide, polyester, polycarbonate, polystyrene, polyvinyl chloride, and polyurethane.
When adopting such an embodiment, when a container made of the film of the present invention is used, a layer made of the resin (A) can be arranged inside or outside the container.

In a second embodiment of the present invention, the resin (A)
Polyolefin, polyamide, polyester,
In this embodiment, at least one type of thermoplastic resin (B) selected from the group consisting of polycarbonate, polystyrene, polyvinyl chloride and polyurethane is laminated. In this case, there is a mode in which the same type of thermoplastic resin (B) is laminated on both surfaces of the resin (A) and a mode in which a different type of thermoplastic resin (B) is laminated.

In a preferred embodiment of the present invention, the second
Of the resin (A), the glass transition point of the resin (A) at the time of absolute drying is 50 ° C. or more, preferably 60 ° C.
Above, more preferably, resin (B) having a melting point higher than 70 ° C. is laminated, and the other surface of resin (A) has a density of 0.98.
g / cm ³ or less, preferably 0.95 g / cm ³ or less, and more preferably 0.93 g / cm ³ or less.

The most preferred embodiment in the present invention is the resin (A)
5% from the glass transition point of the resin (A) when absolutely dry.
0 ° C. or higher, preferably 60 ° C. or higher, more preferably 70 ° C.
Biaxially stretched resin (B) having a melting point higher than ℃
Are laminated, and the other surface of the resin (A) has a density of 0.
In this embodiment, a polyethylene resin (B) of 98 g / cm ³ or less, preferably 0.95 g / cm ³ or less, more preferably 0.93 g / cm ³ or less is laminated. Thereby, the function and effect of the present invention can be sufficiently exhibited.

The film in the present invention includes a so-called sheet-like material in addition to a film-like material. The total thickness of the laminated film according to the present invention is 10 μm.
m or more, preferably 30 μm or more, more preferably 50 μm or more.
μm or more and 300 μm or less, preferably 250 μm
m or less, more preferably 200 μm or less. If the thickness is less than this, the bag-making processability and the drop strength are inferior, and if the thickness is more than this, the bag-making processability is inferior and the economy is also inferior.

The oxygen permeability of the laminated film according to the present invention at 20 ° C. and a relative humidity of 65% is 30 ml / m ² · d
ay.atm or less. Oxygen permeability is preferably not more than ^{20ml / m 2 · day · atm} , more preferably 10ml / m ² · day · atm or less, more preferably is better to less ^{5ml / m 2 · day · atm} . When the oxygen permeability at 20 ° C. and a relative humidity of 65% is larger than the above values, it cannot be used for applications requiring high gas barrier properties.

The oxygen permeability of the laminated film of the present invention at 20 ° C. and 100% RH was 50 ml / m ² ···
It is preferably at most day.atm, more preferably at most 30 ml / m ² .day.atm, even more preferably at most 20 ml / m ² .day.atm, and most preferably at most 10 ml / m ² .day.atm. atm or less. When the oxygen permeability at 20 ° C. and a relative humidity of 85% RH is larger than the above values, it becomes difficult to use the composition in applications requiring high gas barrier properties under high humidity.

The oxygen permeability can be adjusted by appropriately selecting R ¹ and R ² of the resin (A), adjusting the thickness of the resin (A), stretching the resin (A), and stretching the resin (A). A method using the polymerized resin (A) can be exemplified.

The method of laminating the resin (A) and the resin (B) of the present invention is not particularly limited, but typical methods include dry lamination, single-layer extrusion lamination, and multilayer extrusion lamination. Method, coextrusion method, solution coating method and the like. Among these methods, the biaxially stretched film can be used as the layer made of the resin (B), and the dry lamination method, the single-layer extrusion lamination method, and the multilayer extrusion method can be used in that the effects of the present invention can be sufficiently exhibited. Lamination is recommended.

In the present invention, it is preferable to introduce an adhesive layer between the resin (A) film and the resin (B) film in order to obtain a sufficient drop strength. When laminating by dry lamination or extrusion lamination, for example,
Adhesives and the like described in "Lamination Processing Handbook" (September 15, 1978, Processing Technology Research Group) are preferably used.
In the case of forming a multilayer by coextrusion molding, when forming a multilayer with a resin having poor compatibility with the resin (A) of the present invention, such as polyolefin, among the resin (B), maleic anhydride or acrylic acid is used. It is preferable to use a polyolefin modified with an unsaturated carboxylic acid such as the above as an adhesive. In addition, when a resin having relatively good compatibility with the resin (A) such as polyester and polyamide is selected as the resin (B), and the resin (A) is laminated in a molten state as in the co-extrusion method, etc. If an adhesive strength that can be used practically can be obtained without using an adhesive, it is not always necessary to provide an adhesive layer.

The multilayer film according to the present invention may be provided with a collecting layer (regrind layer) for collecting burrs, ears or defective moldings during molding from the viewpoint of economy. Materials other than the resin (B) used in the above, such as paper or aluminum foil, can be laminated as necessary.

The multilayer film according to the present invention comprises edible oils, edible oils and fats products, processed meat and meat products, processed marine products, miso, pickles, seasonings, ketchup, mayonnaise, sauces, dressings, cheeses and butters which require gas barrier properties. ,jelly,
It is processed into containers for packaging foods such as curry roux, jam, soups, delicacies, confectionery, tea, coffee, drinking water, spices, alcoholic beverages, etc. and is most preferably used, but other toiletries such as fragrances, toothpastes, detergents It is also processed into containers for packaging of products, cosmetics, pharmaceuticals, agricultural chemicals, industrial fats and oils, industrial chemicals and the like, and is suitably used. Here, the container is
It refers to a material that can be filled and sealed, and includes, in addition to a pouch, a bag, and the like, a thermoformed container such as a vacuum-formed container and a pressure-formed container, a cup, and a tray.

[0069]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the invention thereto. In the following synthesis examples and comparative examples, unless otherwise specified, the ratio means the weight ratio, and “%” means “% by weight”. The measuring method and the evaluation method are as follows.

(1) Intrinsic viscosity The m-cresol solution was measured at 30 ° C. using an Ostwald viscometer.

(2) Glass Transition Point and Melting Point The glass transition point and melting point are measured by a differential scanning calorimeter (DSC) RDC220 / SSC5200 manufactured by Seiko Instruments Inc.
The measurement was performed based on JIS K7121 using the H type.
However, indium and lead were used for temperature calibration. In addition, the glass transition point at the time of absolute drying referred to in the present invention is determined by measuring the sample according to the JIS.
After the temperature was once raised to 200 ° C. by the method described, the temperature was lowered at a cooling rate of 30 ° C./min to a temperature about 50 ° C. lower than the glass transition point, and the temperature was raised again at a rate of 10 ° C./min. The measured value (2nd. Run) refers to the glass transition point at the time of conditioning at 20 ° C. and 85% RH. The sample was sealed in a sealing pan immediately after sufficient conditioning, and the temperature was raised at a rate of 10 ° C. / Min (1st. Ru)
n). Further, the glass transition point referred to in the present invention is the above-mentioned J
The midpoint glass transition temperature (Tmg) referred to in IS, and the melting point referred to in the present invention refers to the melting peak temperature (Tpm) referred to in JIS.

(3) Saturated Moisture Absorption Rate The weight (X) when the film made of the resin (A) is sufficiently dried in a dryer at 80 ° C. until a constant weight is reached, and 20
Weight when fully conditioned at 65 ° C and 65% RH (Y)
From the formula {(YX) / Y} × 100 (%).
In the case of a multilayer film including a layer made of the resin (A), the saturation moisture absorption of the resin (A) can be similarly obtained. However, when the thermoplastic resin constituting the multilayer film is hygroscopic, the saturated moisture absorption of the thermoplastic resin alone can be obtained by separately calculating the saturated moisture absorption of the thermoplastic resin.

(4) Oxygen permeation amount MODERN CONTROLS INC. It measured according to the method of JIS K7126 (isobaric method) under the conditions of 20 ° C., 65% RH and 20 ° C., 100% RH using an oxygen transmission amount measuring apparatus MOCONOX-TRAN 2/20. The oxygen permeability referred to in the present invention is the oxygen permeability measured at an arbitrary film thickness (unit: ml / m ² · day · atm) of a film composed of a single layer, and the oxygen permeability at a film thickness of 20 μm. Value converted to amount (ml · 2
0 μm / m ² · day · atm). When a multilayer film was measured, a value without such conversion, that is, an oxygen permeation amount (ml / m ² · day · at
m) is shown as it is. (5) Moisture permeability Measured according to the description of JIS Z0208 under the conditions of 40 ° C. and 90% RH, and the film thickness is converted to 30 μm (g · g).
30 μm / m ² · day) was calculated. (6) Haze value A part of the sample film was cut out, silicone oil was applied, and HR-100 manufactured by Murakami Color Research Laboratories was used.
The haze value was measured according to K7105.

(7) Formability of bag making A three-sided sealed bag (pouch, 150 × 230 mm, seal width 15 mm) is used at 180 ° C. seal bar using a high-speed automatic bag making machine HSE-500A manufactured by Saibu Kikai Co., Ltd. The bag was manufactured at a bag making speed of 85 bags / min. Seal surface appearance (dart,
The presence or absence of appearance defects such as pinholes, undulations, whitening, and slippage of seals) and the strength of the seals were evaluated in four stages of ◎ to × based on the following criteria. ◎… extremely good appearance and sealing strength of sealing surface ○… good appearance and sealing strength of sealing surface △… slightly poor appearance and sealing strength of sealing surface ×… poor appearance and sealing strength of sealing surface

(8) Drop strength A three-sided sealed bag (pouch) is filled with 300 g of miso, and after degassing, sealed at a seal width of 15 mm and a seal bar temperature of 170 ° C., for 2 days in an environment of 20 ° C. and 65% RH. After leaving the bag, the bag was dropped from a height of 2.0 m onto the concrete surface so as to be parallel to the concrete surface, and the bag was broken. ◎… No damage and extremely good ○… Very slight damage good △… Not pulverized, but considerable damage was observed in the pouch × Slightly poor ×… Broken and defective

(9) Appearance The appearance of the three-sided sealed bag (pouch) is visually observed, from the viewpoint of the presence of defective appearance such as gel, fish eye, streak, grain pattern, coloring, and transparency (opacity). ◎ ~
The evaluation was made in four stages of ×. ◎ 極 め て Extremely good appearance 良好 Good appearance △… Somewhat poor appearance × Bad appearance

Synthesis Example 1 Atactic polymethallyl alcohol (a-PMA)
Synthesis of AL) Lithium aluminum hydride 25 in a reaction vessel with a cooler
After charging 0 parts by weight, replacing with nitrogen and adding 3000 parts of N-methylmorpholine, the mixture was heated to 130 ° C. and refluxed. Atactic polymethyl methacrylate 6
A solution consisting of 00 parts by weight and 6000 parts of N-methylmorpholine was added, and the mixture was refluxed for 4 hours after completion of the dropwise addition. Thereafter, 1000 parts by weight of ethyl acetate are added dropwise to inactivate unreacted hydrides, and a 50% aqueous solution of phosphoric acid 5000
Parts by weight were added dropwise. After cooling, the mixture was separated into a supernatant and a solid by centrifugation. The obtained supernatant was added to distilled water to precipitate a polymer (No. 1). In addition, 10000 parts of ethanol was added to the obtained solid content, and the mixture was heated and dissolved at 60 ° C. for 1 hour, filtered through a glass filter, and the obtained filtrate was concentrated by an evaporator. 2) was precipitated. The polymer obtained by precipitation (No. 1 and No. 2) was put together at 100 ° C.
After sufficiently washing by boiling with distilled water, vacuum drying was performed to obtain 380 parts by weight of a-PMAAL.

The intrinsic viscosity of the obtained a-PMAAL in m-cresol at 30 ° C. was 0.77 dl / g.
The vacuum-dried polymethallyl alcohol was measured by a scanning differential thermal analyzer (DSC) at a heating rate of 10 ° C./min after being melted and quenched in a nitrogen stream, and the glass transition temperature was 75 ° C. And no crystal melting peak was present. In addition, the glass transition temperature when conditioning at 20 ° C. and 85% RH was 49 ° C. a-PMAAL
Are shown in Table 1.

The thus-obtained a-PMAAL was melt-extruded at 220 ° C. into pellets by a Labo Plastomill manufactured by Toyo Seiki equipped with a twin screw extruder having a screw diameter of 20 mm. Using the obtained pellet, the screw diameter is 20
a-PMAAL having a thickness of 20 μm by forming a single-layer film at a die temperature of 220 ° C. by using a laboratory plastomill manufactured by Toyo Seiki equipped with a uniaxial extruder having a width of 300 mm and a coat hanger die having a width of 300 mm and a lip gap of 0.3 mm. A film was obtained. The resulting film was colorless and transparent, and had a good appearance. Moisture absorption rate, oxygen permeability of the film obtained in Table 1,
The measurement results of the moisture permeability and the haze value are shown.

Synthesis Example 2 Syndiotactic polymethallyl alcohol (s-
Synthesis of PMDAAL) Syndiotactic compound obtained by polymerizing at 0 ° C. in toluene using bis (pentamethylcyclopentadienyl) samarium methyl as an initiator instead of the atactic polymethyl methacrylate used in Synthesis Example 1. An s-PMAAL was obtained and a film was prepared in the same manner as in Synthesis Example 1 except that tick polymethyl methacrylate (having a taxiity of 80% in triad display) was used. The tacticity of the obtained s-PMAAL was analyzed by ¹³ C-NMR measurement in heavy DMSO, and the syndiotacticity was 80% in a triad. Table 1 shows the physical property values of s-PMAAL and the evaluation results of the film.

Synthesis Example 3 Isotactic polymethallyl alcohol (IP
Synthesis of MAAL) Isotactic polymethyl methacrylate obtained by polymerizing in diethyl ether at −78 ° C. using lithium aluminum hydride as an initiator in place of the atactic polymethyl methacrylate used in Synthesis Example 1 ( Taxi tea 93 in triad display
%) Except that i-PMA was used in the same manner as in Synthesis Example 1.
AL was obtained and a film was made. I-PMAA obtained
The tacticity of L was analyzed by ¹³ C-NMR measurement in heavy DMSO, and the syndiotacticity was 90% in triad. Table 1 shows each physical property value of i-PMAAL and the evaluation result of the film.

Synthesis Example 4 Atactic polyallyl alcohol (a-PAAL)
Synthesis of Azobisisobutyronitrile as a catalyst instead of the atactic polymethyl methacrylate used in Synthesis Example 1, except for using atactic polyethyl acrylate obtained by polymerizing in toluene at 80 ° C. In the same manner as in Synthesis Example 1, a-PAAL was obtained, and a film was prepared. Table 1 shows each physical property value of the obtained a-PAAL and evaluation results of the film.

Synthesis Example 5 Styrene-methallyl alcohol random copolymer (S
Synthesis of T-MAAL) The styrene-methyl methacrylate random copolymer obtained by polymerizing at 80 ° C. in toluene using azobisisobutyronitrile as a catalyst instead of the atactic polymethyl methacrylate used in Synthesis Example 1 was used. ST-MAAL (styrene content 75 mol%, methallyl alcohol content 25 mol) in the same manner as in Synthesis Example 1 except that a polymer (styrene content 75 mol%, methyl methacrylate content 25 mol%) was used. %) To produce a film. ST-MAA obtained
Table 1 shows the physical property values of L and the evaluation results of the film.

Reference Example 1 An ethylene-vinyl alcohol copolymer (ethylene content 32 mol%, saponification degree 99.5%) was formed into a single layer under the same conditions as in Synthesis Example 1 to obtain a film, which was evaluated. Was. The evaluation results are summarized in Table 1.

Reference Example 2 A commercially available biaxially stretched polypropylene film (OPP, “Tocello OP U-1” manufactured by Tosero Corporation, melting point: 155 ° C.)
The same evaluation as in Synthesis Example 1 was performed for a thickness of 20 μm). The evaluation results are summarized in Table 1.

[0086]

[Table 1]

Example 1 The a-PMAAL obtained in Synthesis Example 1 was melt-extruded at 210 ° C. into pellets by a Labo Plastomill manufactured by Toyo Seiki Co., Ltd. equipped with a twin screw extruder having a screw diameter of 20 mm. Using the obtained pellet, screw diameter 2
A 15 μm thick a was formed by forming a single layer film at a die temperature of 210 ° C. using a Lab Plast Mill manufactured by Toyo Seiki Co., Ltd. equipped with a 0 mm uniaxial extruder and a coat hanger die having a width of 300 mm and a lip gap of 0.3 mm -A film of PMAAL was obtained. The melt film-forming property was extremely good, and the obtained film was colorless and transparent with no gel, fish eye, streak or grain pattern, and had a good appearance.

Next, a biaxially stretched polypropylene film (OPP, “Tocello OP U-1” manufactured by Tosello Co., Ltd.)
A urethane-isocyanate-based adhesive ("Takelac A-385" / "Takenate A-10" manufactured by Takeda Pharmaceutical Co., Ltd.) with a solid content of 2.5 g / m ² is applied to one surface having a melting point of 155 ° C. and a thickness of 20 μm. After the application, the a-PM
AAL film is laminated by dry lamination
Laminated film of PP / a-PMAAL configuration (total thickness 35μ)
m). A-PMAAL of the obtained laminated film
The surface was sealed as a sealing surface, and a pouch was made and evaluated.
Table 2 shows the evaluation results.

Example 2 a- of the OPP / a-PMAAL configuration obtained in Example 1
Linear low density polyethylene (LLDPE,
Tocelo TUX-TC, manufactured by East Cerro, density 0.9
2 g / cm ³ and a thickness of 65 μm) were laminated by a dry lamination method in the same manner as in Example 1 to obtain an OPP / a−
PMAAL / LLDPE laminated film (total thickness 10
0 μm). Next, sealing was performed using the LLDPE surface as a sealing surface, and a pouch was formed and evaluated. Table 2 shows the evaluation results.
Shown in

Example 3 OPP in Example 2 was replaced with a biaxially stretched polyamide-6 film (ON, “Emblem ON # 15” manufactured by Unitika Ltd.).
00 ”, melting point 220 ° C., thickness 15 μm) in the same manner as in Example 2 except that ON / a-PMAAL /
A laminated film (total thickness: 95 μm) having an LLDPE configuration was prepared and sealed using the LLDPE surface as a sealing surface, and a pouch was formed and evaluated. Table 2 shows the evaluation results.

Example 4 The OPP in the case of Example 1 was obtained by converting a linear low-density polyethylene film (LLDPE, “Tocelo TUX-
TC ”, density 0.92 g / cm ³ , thickness 65 μm) and a-PMAAL / LLDPE in the same manner as in Example 1.
Make a laminated film (total thickness 80μm)
The surface E was sealed as a sealing surface, and a pouch was prepared and evaluated. Table 2 shows the evaluation results.

Example 5 OPP was performed in the same manner as in Example 2 except that s-PMAAL obtained in Synthesis Example 2 was replaced with a-PMAAL in Example 2.
A laminated film (total thickness 100 μm) having a / s-PMAAL / LLDPE configuration was prepared, and the LLDPE surface was sealed as a sealing surface, and a pouch was formed and evaluated. Table 2 shows the evaluation results.

Example 6 OPP was carried out in the same manner as in Example 2 except that a-PMAAL in Example 2 was replaced with i-PMAAL obtained in Synthesis Example 3.
A laminated film (total thickness: 100 μm) having a configuration of / i-PMAAL / LLDPE was prepared, the LLDPE surface was sealed as a sealing surface, and a pouch was formed and evaluated. Table 2 shows the evaluation results.

Example 7 a- of the OPP / a-PMAAL configuration obtained in Example 1
Adhesive for urethane-isocyanate anchor coat (Takelac A- manufactured by Takeda Pharmaceutical Co., Ltd.)
503 "/" Takenate CAT-10 ").
After application at a basis weight of 3 g / m ² , low-density polyethylene (LDPE, polyethylene-LD LC manufactured by Mitsubishi Chemical Corporation) was applied to the application surface.
500, density 0.92 g / cm ³ , thickness 65 μm)
Laminated by extrusion lamination, OPP / a-PMAA
A laminated film (100 μm in total thickness) having an L / LDPE configuration was prepared. Next, sealing was performed using the LDPE surface as a sealing surface, and a pouch was formed and evaluated. Table 2 shows the evaluation results.

Example 8 In the case of Example 2, the OPP was treated with a biaxially stretched polyethylene terephthalate film (OPET, “Emblet PET-12” manufactured by Unitika Ltd., melting point 260 ° C., thickness 12 μm).
m), and OPET / a-
PMAAL / LLDPE laminated film (total thickness 92
μm) was prepared and sealed using the LLDPE surface as a sealing surface, and a pouch was prepared and evaluated. Table 2 shows the evaluation results.

Example 9 Copolyamide-6, 66 (COPA, “Amilan CM6041” manufactured by Toray Industries, Ltd., melting point: 200 ° C., thickness: 20 μm)
m), adhesive polymer (AD, Mitsui Petrochemical Industry Co., Ltd.)
"Admer NF550", density 0.91g / c
m ³ ), ionomer (IO, “Himilan 1652” manufactured by DuPont-Mitsui Polychemicals Co., Ltd.), density 0.94 g
/ Cm ³ ) and a-PMAA obtained by Synthesis Example 1
COA (thickness: 20 μm) / a-PMAAL4
(Thickness 15 μm) / AD (thickness 10 μm) / IO (thickness 95 μm) coextruded film (total thickness 140 μm)
Was formed. Extrusion temperature is a-PMAAL extruder 210
° C, COPA extruder 235 ° C, IO extruder 210 ° C, feed block 235 ° C, and die 230 ° C. The melt film-forming property was extremely good, and the obtained film was colorless and transparent without gel, fish eye, streak and grain pattern, and had a good appearance. The obtained laminated film was sealed using the IO surface as a sealing surface, and a pouch was formed and evaluated. Table 2 shows the evaluation results.

Comparative Example 1 A pouch was formed from the a-PMAAL single-layer film (15 μm thick) obtained in Example 1 and evaluated. Table 2 shows the evaluation results.

Comparative Example 2 A pouch was prepared and evaluated in the same manner as in Example 2 except that the thickness of the a-PMAAL in Example 2 was changed to 55 μm. Table 2 shows the evaluation results.

Comparative Example 3 In the same manner as in Example 2 except that a-PMAAL in Example 2 was replaced with a-PAAL obtained in Synthesis Example 4, OPP /
a-PAAL / LLDPE laminated film (total thickness 1
00 μm), and sealing was performed using the LLDPE surface as a sealing surface, and a pouch was formed and evaluated. Table 2 shows the evaluation results.

Comparative Example 4 The procedure of Example 2 was repeated, except that a-PMAAL in Example 2 was replaced with ST-MAAL obtained in Synthesis Example 5 to obtain an OP.
A laminated film (total thickness: 100 μm) having a P / ST-MAAL / LLDPE configuration was prepared and sealed using the LLDPE surface as a sealing surface, and a pouch was prepared and evaluated. Table 2 shows the evaluation results.

Comparative Example 5 In the case of Example 2, a-PMAAL was treated with an ethylene-vinyl alcohol copolymer (EVOH, ethylene content 30 mol%, saponification degree 99.6%, melting point 185 ° C., thickness 15 μm).
m) in the same manner as in Example 2 except that OP
P / EVOH / LLDPE laminated film (total thickness 1
00 μm), and sealing was performed using the LLDPE surface as a sealing surface, and a pouch was formed and evaluated. Table 2 shows the evaluation results.

[0102]

[Table 2]

Example 10 A low-density polyethylene (LDPE) film having a thickness of 50 μm and having a corona-treated surface bonded to both surfaces of the a-PMAAL single-layer film obtained in Synthesis Example 1 was coated with a urethane-based adhesive. By laminating, LDPE / a-
PMAAL / LDPE = 50 μm / 20 μm / 50 μm
Was obtained. 20 g of ketchup was heat-sealed and sealed in a nitrogen box on each of two 10 cm square films, and a storage test was conducted at 40 ° C. and 50% relative humidity for 180 days. As a result, no discoloration was observed in the ketchup.

Comparative Example 6 Two 100 μm thick films were obtained by laminating two 50 μm corona-treated low density polyethylene films via a urethane-based adhesive. Using this film, ketchup was sealed in the same manner as in Example 4. As a result of a storage test performed in the same manner as in Example 4, the ketchup turned black.

[0105]

According to the present invention, gas barrier properties under low and high humidity, bag-making properties, drop strength, appearance,
A laminated film having an excellent effect on melt moldability can be obtained.

Claims (8)

[Claims] 1. A film having a thickness of 0.5 to 50 μm comprising an allyl alcohol-based polymer resin (A) containing at least 30 mol% of a repeating structural unit represented by the following formula (1): A laminate of at least one thermoplastic resin (B) film selected from the group consisting of polyamide, polyester, polycarbonate, polystyrene, polyvinyl chloride and polyurethane;
Oxygen permeation rate at 30 ° C and 65% relative humidity is 30ml / m
^A multilayer film having a size of ² * day * atm or less. Embedded image (In the formula, R ¹ represents an alkyl group having 1 to ² carbon atoms, and R ² represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.) 2. The resin (A) has a glass transition point of 4 at the time of absolute drying.
The multilayer film according to claim 1, wherein the temperature is 5 to 95C. 3. The multilayer film according to claim 1, wherein the resin (A) has a glass transition point of not less than 20 ° C. when conditioned at 20 ° C. and 85% RH. 4. The multilayer film according to claim 1, wherein the saturated moisture absorption of the resin (A) at 20 ° C. and 65% RH is 0.5 to 15% by weight. 5. The multilayer film according to claim 1, wherein the resin (A) has a moisture permeability at 30 ° C. and 90% relative humidity of 30 g · 30 μm / m ² · day or less. 6. A resin (A) at 20 ° C. and a relative humidity of 100%
Oxygen permeability at 30 ml / 20 μm / m ² · da
The multilayer film according to any one of claims 1 to 5, which has a value of y · atm or less. 7. The multilayer film according to claim ¹ , wherein R ¹ in the formula (1) is CH ₃ and R ² is H. 8. A packaging container comprising the multilayer film according to claim 1.