JPH0664116A - Multilayer laminated body - Google Patents

Abstract

PURPOSE: To inexpensively provide a multilayered laminate excellent in gas barrier properties and mechanical strength, not lowered in gas barrier properties even by retort treatment or boiling treatment and excellent in the pressrbability of content. CONSTITUTION: In a multilayered laminate containing a humidity absorbable gas barrier resin layer, as a resin forming a surface layer, a resin compsn. consisting of 2-60 wt.% of (A) an ethylenic copolymer containing an ethylene unit and an acrylamide deriv. and/or a methacrylamide deriv. unit and 98-40 wt.% of (B) other thermoplastic resin is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel multilayer laminate, and more specifically, it has excellent gas barrier properties and does not deteriorate in gas barrier properties even when subjected to retort treatment or boil treatment. The present invention relates to a multilayer laminate suitably used for a packaging film for articles and containers.

[0002]

2. Description of the Related Art Conventional multilayer laminates having gas barrier properties used for packaging films and containers for foods, medical products, etc. include, for example, saponified ethylene-vinyl acetate copolymer resin (hereinafter referred to as EVOH). Abbreviated), acrylonitrile copolymer resin, polyvinyl alcohol resin, polyamide resin (hereinafter abbreviated as PA), vinylidene chloride copolymer or other resin having a high oxygen barrier property, or metal foil such as aluminum foil is used as a gas barrier layer, Further, a layer obtained by laminating a hydrophobic polyolefin resin such as polyethylene, polypropylene or ethylene / α-olefin copolymer on this layer is used.

Among these, a multilayer laminate using a hygroscopic gas barrier resin such as EVOH, PA or polyvinyl alcohol resin has a gas barrier layer sufficiently suppressing the permeation of gas such as oxygen under a low humidity, so that the contents of Although it has the feature that the quality of the contents is stable over a long period of time by preventing oxidation, when this multilayer laminate is used by boiling in high temperature water of 90 to 135 ° C, such as a retort food packaging material. Water penetrates through the outer layer and is adsorbed by the gas barrier layer, and the gas barrier layer is made of a resin having a high water absorbing property such as an olefin-vinyl acetate copolymer saponified resin, a polyvinyl alcohol resin, or a polyamide resin. In this case, this moisture causes a rapid decrease in the gas permeation resistance of the gas barrier layer, and the function of the gas barrier layer is lost. There are, for applications such as retort food there is a problem that can not be used.

For example, when a multi-layer laminate having a thickness of about 100 μm and made of polypropylene, an adhesive resin layer and EVOH is retort-treated, EV is obtained under retort conditions of 120 ° C. or higher.
The water content adsorbed on OH may be 7% by weight or more, and the oxygen permeability before retort treatment may increase 1000 times or more. Therefore, as a method to improve such inconvenience,
For example, a method has been proposed in which a desiccant composed of an inorganic metal salt is added to the adhesive layer for adhering the gas barrier layer and the outer layer, and the invading water is captured by this layer to prevent the deterioration of the gas barrier performance. (European Patent No. 59274,
U.S. Pat. Nos. 4,407,897, 4,464,443 and JP-A-57-170748). However, in this method, there is a problem in that the interlayer adhesion strength between the adhesive layer and the gas barrier layer is reduced, and the inorganic metal salt is present as a foreign substance, so that the application is inevitably limited.

Further, a method for improving water resistance by adding a phenol compound (US Pat. No. 4,347,337,
No. 4,289,830), a method of laminating a polyamide resin or a mixture thereof as an outermost layer adjacent to a polycarbonate resin having good water vapor permeability or an EVOH layer (JP-A-1-253442, JP-A-1-308626). Publication, European Patent No. 322891) is disclosed. However, although these methods may be effective for thin products such as films, they are not effective for thick products such as sheets and bottles, and cost is high, and multilayer extrusion of polycarbonate resins is not possible. It is difficult and requires special extrusion equipment.

On the other hand, in a multilayer laminate including an EVOH layer, a method has been attempted in which the EVOH layer is arranged at an outer position to accelerate the recovery of the gas barrier property after the retort treatment ["Paper, Film and Foil].・ Converter (Paper, Film & Foil Converter) "October issue, No. 5
Page 4 (1985), "Food Package" November issue, page 82 (1985), December issue, 67
Page (1985), "COEX'89", Page 267 (1989) (Schotland Business Research, I)
sponsored by nc. (USA))]. However, in this method, since the multilayer thickness is a non-symmetrical multilayer structure, the target shape has the same outer layer thickness in coextrusion molding and the like.
Where only one extruder for the resin for the outer layer is required, another extruder is required, which is disadvantageous in terms of cost and the gas barrier property is not sufficiently restored. There is.

Furthermore, recently, it has been attempted to use EVOH having a high ethylene unit content and to preliminarily set the thickness of the EVOH layer to a large value in anticipation of a decrease in gas barrier property due to the retort treatment [[Future- PAK'90 "1st
25 pages (1990), Ryder Associates, Inc.
(USA)]. However, this method has the disadvantage that it is unavoidably expensive. Further, a method of blending a polymer network structure such as a vinyl alcohol-acrylate copolymer network structure with either the oxygen barrier layer or the outer layer or the adhesive layer (JP-A-62-182030).
JP-A-62-208344) and a method of blending an inorganic powder such as mica and sericite with the outer layer and the EVOH layer (JP-A-2-47139). However, in the former method, the polymer network structure is inferior in melt moldability and thermal stability, so that there is a problem in molding, and in the latter method, since the inorganic powder is blended, it becomes hard and brittle. There was a problem.

[0008]

Under these circumstances, the present invention does not require a special extrusion device, has an excellent gas barrier property, and has a reduced gas barrier property even by a retort process or a boil process. The purpose of the invention is to provide a multi-layer laminate that does not do so at low cost.

[0009]

Means for Solving the Problems As a result of intensive research to develop a multilayer laminate having the above-mentioned preferable properties, the present inventors have found that the surface of a multilayer laminate containing a hygroscopic gas barrier resin layer is It has been found that the purpose can be achieved by using a specific resin composition as the resin forming the layer. The present invention has been made based on such findings. That is, the present invention relates to a multi-layer laminate including a hygroscopic gas barrier resin layer, wherein an ethylene-based copolymer containing (A) an ethylene unit and an acrylamide derivative and / or a methacrylamide derivative unit is used as a resin forming a surface layer. The present invention provides a multilayer laminate characterized by using a resin composition comprising 2 to 60% by weight and (B) another thermoplastic resin 98 to 40% by weight.

In the multi-layer laminate of the present invention, a hygroscopic gas barrier layer is provided, and the hygroscopic gas barrier layer comprises a saponified olefin vinyl acetate copolymer and / or
Alternatively, a polyamide resin is preferably used. Examples of the olefin-vinyl acetate copolymer saponified resin include EVOH and propylene-vinyl acetate copolymer saponified resin, but EV is particularly preferable because of easy polymerization.
OH is preferably used. It is preferable that the EVOH contains ethylene units in an amount of 15 mol% or more, preferably 15 to 60 mol% and the vinyl acetate component has a saponification degree of 90 mol% or more. Content of ethylene unit is 1
If it is less than 5 mol%, the melt moldability will be insufficient, and if it exceeds 60 mol%, the gas barrier property will deteriorate. Further, if the saponification degree is less than 90 mol%, the gas barrier property is deteriorated.
Particularly, EVOH having an ethylene unit content of 25 to 50 mol% and a saponification degree of 96 mol% or more is preferable.

In addition to ethylene units, vinyl acetate units, and vinyl alcohol units formed by saponifying them, unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, and maleic acid, alkyl esters thereof, or propylene and butene. , Α-decene, α-octadecene and other α-olefins may be included. On the other hand, examples of polyamide resins include lactams, ε-amino acids, and polycondensates of dibasic acids and diamines. Specifically, polymers such as ε-caprolactam, aminolactam, enanthlactam, 11-aminoundecanoic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, α-pyrrolidone and α-piperidone, and hexamethylenediamine and nonamethylene. Diamines such as diamine, undecamethylenediamine, dodecamethylenediamine, metaxylylenediamine and terephthalic acid,
Examples thereof include polycondensates with dicarboxylic acids such as isophthalic acid, adibic acid, sebacic acid, dodecane dibasic acid and glutaric acid, or copolymers thereof. Furthermore, specifically, nylon 4, nylon 6, nylon 7, nylon 8, nylon 11, nylon 12, nylon 6.6, nylon 6.9, nylon 6/10, nylon 6/11,
Examples include nylon 6/12 and nylon MXD.

In the multilayer laminate of the present invention, as the resin forming the surface layer, (A) an ethylene-based copolymer containing an ethylene unit and an acrylamide derivative and / or a methacrylamide derivative unit, and (B) another thermoplastic resin. A resin composition containing a resin is used. Regarding the ethylene-based copolymer containing the ethylene unit and the acrylamide derivative and / or the methacrylamide derivative unit, "Polymer Thesis Collection", Vol. 35, No. 12, p. 795 (1978).
), U.S. Pat. No. 3,829,209, JP-B-43-2
1655, JP-B-44-19537, JP-B-43-23766, JP-B-43-9063, JP-A-63-304010, and the like. . Examples of the acrylamide derivative or methacrylamide derivative constituting the ethylene-based copolymer include N-alkylacrylamide; N, N-dialkylacrylamide; N-alkylmethacrylamide; and N, N-dialkylmethacrylamide. Specifically, N-methyl acrylamide; N
-Ethyl acrylamide; Nn-propyl acrylamide; N-isopropyl acrylamide; Nn-butyl acrylamide; N-isobutyl acrylamide; N
-T-butylacrylamide; N, N-dimethylacrylamide; N, N-diethylacrylamide; N-ethylmethacrylamide; Nn-propylmethacrylamide; Nt-butylmethacrylamide; N, N-dimethylmethacrylamide; N, N-diethylmethacrylamide and the like can be mentioned, and these can be used alone or as a mixture. Of these, N-ethyl acrylamide; N-isopropyl acrylamide; Nt-
Butyl acrylamide; N, N-dimethyl acrylamide; N, N-diethyl acrylamide; Nn-propyl methacrylamide; Nt-butyl methacrylamide and the like are preferable.

The content of the acrylamide derivative and / or methacrylamide derivative unit in the ethylene copolymer is usually 0.1 to 50% by weight, preferably 1 to 45% by weight. When this content is less than 0.1% by weight, when mixed with other thermoplastic resins, the compatibility is poor, and the effect of preventing gas barrier property deterioration due to retort treatment is not sufficiently exerted, and the recovery speed is low. Not preferable. On the other hand, if it exceeds 50% by weight, problems such as a decrease in rigidity of the multilayer laminate may occur, which is not preferable. In addition,
The ethylene-based copolymer resin may contain a unit derived from other polymerizable monomer, in addition to the ethylene unit and the acrylamide derivative and / or methacrylamide derivative unit. Here, examples of the other polymerizable monomer include an ester compound, an acid compound, an ether compound, and a hydrocarbon compound each having an unsaturated bond.

Examples of the ester compound having an unsaturated bond include vinyl acetate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate,
Hexyl acrylate, octyl acrylate, lauryl acrylate, benzyl acrylate, N, N-dimethylaminoethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, octyl methacrylate, Lauryl methacrylate, N, N-dimethylaminoethyl methacrylate, methyl fumarate, ethyl fumarate, propyl fumarate, butyl fumarate, dimethyl fumarate, diethyl fumarate, dipropyl fumarate, dibutyl fumarate, methyl maleate, Examples thereof include ethyl maleate, propyl maleate, butyl maleate, dimethyl maleate, diethyl maleate, dipropyl maleate and dibutyl maleate.

Examples of the acid compound having an unsaturated bond include acrylic acid, methacrylic acid, maleic acid and fumaric acid. Examples of the ether compound having an unsaturated bond include methyl vinyl ether,
Examples include ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octadecyl vinyl ether, and phenyl vinyl ether. Furthermore, examples of the hydrocarbon compound having an unsaturated bond include styrene, norbornene, butadiene, acrylonitrile, methacrylonitrile, acrolein, crotonaldehyde, trimethoxyvinylsilane, vinyl chloride, and the like.
Examples thereof include vinylidene chloride. These monomers of the third component may be used alone or in combination of two or more depending on the intended use. The content of the units derived from the monomer of the third component in the copolymer is preferably 40% by weight at most. The content is 4
If it exceeds 0% by weight, the inherent properties of the ethylene copolymer may be impaired.

Basically, the above-mentioned third component monomer is preferably one that does not react with an acrylamide derivative or a methacrylamide derivative, but if the usage amount is selected in consideration of stoichiometry, it is possible to obtain these derivatives. Reactive monomers can be used. In particular, for applications requiring transparency, it is preferable to contain at least 3% by weight of the monomer of the third component in order to reduce the crystallinity of the ethylene copolymer. More preferably at least 5% by weight, particularly preferably at least 10% by weight is used. Further, when used in a field requiring oil resistance in industrial material applications, it is preferable to select and copolymerize a monomer having a high polarity as the third component. In particular, acrylonitrile, acrylic acid, acrylic acid ester and the like can be given as specific preferred monomers.

Furthermore, in the field of food packaging, where the application is hygienic, low odor and low taste are strongly required. The odor of the monomer of the third component usually depends on the amount remaining in the copolymer and cannot be unconditionally limited, but is preferably at most 10% by weight. Particularly, it is desirable that the amount of the monomer is at most 3% by weight. Strictly odorless
It is preferred that no or very little third component comonomer having a strong odor is used in the laminate for applications where tastelessness is required, and the amount of the comonomer is at most 1% by weight. Melt index of the layer containing the above ethylene copolymer (MFR, load of 2.16 k according to JIS K-6758)
g, measured at a temperature of 230 ° C.) is not particularly limited and may be appropriately selected depending on the molding method, but in the extrusion molding, the range of 0.1 to 100 g / 10 minutes is suitable.

On the other hand, other thermoplastic resins used as the component (B) in the resin composition include, for example, polyolefin resins represented by polypropylene and polyethylene, polyamide resins, polystyrene resins, polyester resins, etc. Is mentioned. The polyolefin resin refers to medium / high density polyethylene, pomopolypropylene, ethylene-propylene random copolymer, ethylene-propylene block copolymer, ethylene and α-olefin copolymer having 3 to 12 carbon atoms. Examples of ethylene and an α-olefin copolymer having 3 to 12 carbon atoms include ethylene-butene-1 copolymer, ethylene-4 methylpentene-1 copolymer, ethylene-hexene-1 copolymer and ethylene-butene. -1 Modified polypropylene blended with ethylene-propylene rubber, etc.,
Modified polybutene, modified ethylene-4-methylpentene, etc. are available. Further, as the polyolefin resin, an unsaturated carboxylic acid or its acid anhydride is grafted onto the above polyolefin polymer under an organic peroxide or is copolymerized with another monomer (for example, methyl methacrylate, ethyl acrylate, etc.). You can list things such as things.

Of these, polypropylene-based resins such as homopolypropylene, ethylene-propylene random copolymers, ethylene-propylene block copolymers, etc. are especially preferable considering the sterilization means commonly used for packaging foods and pharmaceuticals, so-called retort treatment. preferable. Also, E
When VOH is used as the gas barrier layer, a polyamide resin may be used as a blend partner of the ethylene copolymer. Regarding the mixing location in the multilayer laminate of the ethylene copolymer, it is effective to mix it in any layer such as the adhesive layer, the intermediate layer and the surface layer except the hygroscopic gas barrier resin layer, but at least the surface As the resin forming the layer, it is necessary to use a resin composition composed of the ethylene copolymer and another thermoplastic resin. In the resin composition forming the surface layer, it is necessary to blend the ethylene-based copolymer in an amount of 2 to 60% by weight and the other thermoplastic resin in an amount of 98 to 40% by weight.

The content of the ethylene copolymer is 2% by weight.
If it is less than 60% by weight, the effect of preventing the deterioration of the gas barrier property due to the retort treatment is not exhibited, and if it exceeds 60% by weight, the shrinkage due to the retort treatment or the boil treatment becomes large, which is not preferable. The preferable blending amount of the ethylene copolymer is 5
Is in the range of 50% by weight. This resin composition layer is EV
It may be provided adjacent to the hygroscopic gas barrier layer such as OH or may be provided separately. When stacking adjacently,
When the hygroscopic gas barrier layer has excellent adhesiveness to the resin layer containing the ethylene copolymer, such as EVOH or PA, they may be directly adjacent to each other. When it is provided separately from the hygroscopic gas barrier layer, it may be laminated adjacent to a normally used adhesive layer. In this case, the adhesive peel strength with EVOH or PA is improved, which is particularly preferable. In this case, in order to bring out the effect of the laminate of the present invention, it is preferable to laminate the adhesive layer as thinly as possible as usual (the thickness of the adhesive layer usually accounts for 30% of the whole laminate). % Or less.).

The method for processing the multilayer laminate of the present invention includes:
A coextrusion method is used. Using a known adhesive resin, the number of extruders corresponding to the type of resin is used, and the coextrusion molding (feed) is performed in which the flows of the resin melted in the extruder are co-extruded in a multilayered state. Block, multi-manifold). As a known adhesive resin used in such a co-extrusion molding method, there is a resin obtained by grafting or copolymerizing an unsaturated carboxylic acid, an acid anhydride or an ester monomer with a polyolefin resin. The grafting method at this time is a method in which the polyolefin resin is an organic peroxide and the above components are melt-graft modified by using an extruder or the like, or the polyolefin resin is dissolved in hot xylene and the above components are added with an organic peroxide. There is a method of grafting. Unsaturated carboxylic acid, acid anhydride, and ester monomer include methacrylic acid, acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate,
2-hydroxyethyl methacrylate, diethyl maleate, monoethyl maleate, -n-butyl maleate,
Maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, 5-norbornene-2,3-anhydride, citraconic acid, citraconic anhydride, crotonic acid, crotonic anhydride, acrylonitrile, methacrylonitrile, acrylic Examples thereof include sodium acrylate, calcium acrylate, magnesium acrylate, and the like.

US Patents for these graft polymers
4,026,967, U.S. Pat. No. 3,953,655, JP-A-51-98784, and JP-B-44-15.
No. 423, Japanese Patent Publication No. 49-4822, and the like. In addition, the multilayer laminate of the present invention can be dried by using a co-injection molding method, a co-extrusion pipe molding method, or a so-called dry laminating adhesive such as polyethyleneimine or a titanate coupling agent, an isocyanate acrylic type, a polyurethane type or a polyester type. It may be produced by a laminate molding method or a sandwich lamination molding method, or may be obtained by various molding methods such as a coextrusion lamination molding method. The multilayer laminate thus obtained can be reheated by using a vacuum forming machine, a compressed air forming machine, a stretch blow molding machine, or the like, or subjected to a stretching operation, or the above-mentioned multilayer laminate can be uniaxially or biaxially stretched. A heat stretching operation can be performed using an axial stretching machine.

[0023]

Although the reason for the multilayer laminate of the present invention is not clear,
Moisture that enters during the retort treatment is adsorbed by the layer containing the ethylene-based copolymer that is also a hygroscopic material before being adsorbed by the hygroscopic gas barrier layer of the intermediate layer, or the moisture absorbed after the retort treatment. It is considered that the gas can be evaporated at an early stage, and the gas barrier performance originally possessed by the gas barrier layer can be maintained without being impaired.

[0024]

EXAMPLES Next, the present invention will be described in more detail by way of Examples Production Example 1 (Production of ethylene-N, N-dimethylacrylamide copolymer) Autoclave type reaction divided into 2 zones with an internal volume of 4 liters In a vessel, polymerization is performed at a temperature of 190 to 210.
It was carried out using t-butyl peroxide as an initiator under the conditions of a temperature of 110 ° C. and a pressure of 1100-1300 atm. N, N-dimethyl acrylamide and acrylamide are used as the acrylamide component, these and other monomers and / or
Alternatively, the solvent was injected upstream of the second stage compressor and fed with ethylene into the first zone of the reactor. The produced copolymer is separated into unreacted monomers by a high-pressure separator and a low-pressure separator, pelletized by using an extruder, and the following (a)-
The copolymer shown in (e) was produced. The N, N-dimethylacrylamide and acrylamide contents were determined using an infrared spectrometer and ¹³ C-NMR. (A) Ethylene-N, N-dimethylacrylamide copolymer (MFR 3.5 g / 10 minutes, N, N-dimethylacrylamide content = 19.2% by weight) (b) Ethylene-N, N-dimethylacrylamide copolymer Combined (MFR 3.7 g / 10 min, N, N-dimethylacrylamide content = 37% by weight) (c) Ethylene-acrylamide copolymer (MFR 4.6
g / 10 minutes, acrylamide content = 11.4% by weight) (d) Ethylene-methylmetallate-N, N-dimethylacrylamide copolymer (MFR 5.1 g / 10 minutes, methylmethacrylate content = 6.2 weight) %, N, N-dimethylacrylamide content = 9.1% by weight) (e) Ethylene-vinyl acetate-N, N-dimethylacrylamide copolymer (MFR 5.1 g / 10 min, vinyl acetate content = 3.4) %, N, N-dimethylacrylamide content = 24.1% by weight)

Production Example 2 (Production of Resin Composition for Forming Surface Layer) Using a 40 mmφ single screw extruder, JIS K-7210 (temperature 230 ° C.,
PP-I, which is a homopolypropylene resin having a melt flow rate (MFR) of 0.52 g / 10 minutes measured according to a load of 2.16 kg) and PP-II which is a block polypropylene resin having an MFR of 0.74 g / 10 minutes. Specific gravity 1.1
1022B manufactured by Ube Industries, Ltd. which is Nylon 6 of No. 4 and the copolymer obtained in Production Example 1 were mixed in a tumbler at various compounding ratios and then pelletized to obtain a resin composition shown in Table 1.

[0026]

[Table 1]

Example 1 "Soarnol DT" manufactured by Nippon Synthetic Chemical Industry Co., Ltd. having an ethylene unit content of 29 mol% was used as EVOH, and the adhesive resin layer was MFR (according to JIS K-7210,
The value measured under the conditions of temperature 230 ° C and load 2.16 kg)
A modified polypropylene resin [ADTEX ER321P (trade name) manufactured by Showa Denko KK] was used for 5.5 g / 10 minutes. Further, as a resin composition for forming the surface layer, the first
The resin composition (f) shown in the table was used. Die temperature 220
Using a feed block multi-layer sheet molding machine at
A multilayer sheet was created. The multi-layered sheet thus obtained was then subjected to a vacuum forming machine to obtain a drawing ratio of 0.5 and an internal volume of 100.
I made a cc container. This container is subjected to retort treatment at 125 ° C. for 30 minutes, and OXTRAN-made by Modern Control
Before and after retort using 10 / 50A, 23 ℃,
The oxygen gas barrier properties of three containers were measured under the condition of 65% RH, and the average value was obtained. The layer structure and thickness of this container were as follows. In addition, a normal homopolypropylene resin containing no ethylene-based copolymer is used
P, the resin composition is represented by CON, the adhesive resin is represented by AD, and EVOH is represented by EV. PP / AD / EV / AD / CON = 425/10/30
/ 10/425 μm

The oxygen permeation amount of this container is 0.0 before retort.
1 (cc / container / day / atm), 1.28 after retort
(Cc / container / day / atm). After that, it was stored for 1 month at a temperature of 23 ° C. and a relative humidity of 50 RH%, and the amount of oxygen permeation was measured to be 0.03 (cc / container · day ·
was atm).

Comparative Example 1 The procedure of Example 1 was repeated, except that the resin for the surface layer was changed to PP-I. As a result, the oxygen transmission rate was 0.01 (cc / container / day) before retort treatment.
・ Atm), after retort treatment 3.32 (cc / container ・ da
y • atm), and the oxygen permeation amount after one month is 0.79.
(Cc / container / day / atm).

Examples 2 to 15 and Comparative Examples 2 and 3 The resin compositions shown in Table 1 were selected and carried out in the same manner as in Example 1. The results are shown in Table 2.

[0031]

[Table 2]

[0032]

[Table 3]

[0033]

EFFECTS OF THE INVENTION According to the present invention, a multi-layered laminate having excellent gas barrier properties and mechanical strength, which does not deteriorate in gas barrier properties even by retort treatment or boil treatment, and which is excellent in storage stability of contents can be obtained. No need for extrusion equipment,
It can be obtained at low cost. The multilayer laminate of the present invention,
For example, it is suitable for use in packaging films and containers for food and medical products.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazuyuki Watanabe 2 Ooita City, Oita City Nakanosu, Showa Denko Co., Ltd. (72) Inventor Toshiyuki Iwashita 2 Oita, Oita City Nakanosu Oita Research Showa Denko Co., Ltd. In-house

Claims (7)

[Claims] 1. A multi-layer laminate comprising a hygroscopic gas barrier resin layer, wherein the resin forming the surface layer is (A)
Ethylene copolymers 2 to 6 containing ethylene units and acrylamide derivative and / or methacrylamide derivative units
A multi-layer laminate comprising a resin composition comprising 0% by weight and (B) another thermoplastic resin of 98 to 40% by weight. 2. An ethylene-based copolymer containing an ethylene unit and an acrylamide derivative and / or a methacrylamide derivative unit contains the acrylamide derivative and / or a methacrylamide derivative unit in a proportion of 0.1 to 50% by weight. The multilayer laminate according to claim 1. 3. The acrylamide derivative unit is an N-alkyl-substituted acrylamide derivative unit.
The multilayer laminate described. 4. The multilayer laminate according to claim 1, wherein the acrylamide derivative unit is an N, N-dimethylacrylamide unit. 5. The multilayer laminate according to claim 1, wherein the hygroscopic gas barrier layer (A) is a saponified olefin-vinyl acetate copolymer resin and / or a polyamide resin. 6. The multilayer laminate according to claim 5, wherein the olefin-vinyl acetate copolymer saponified resin is an ethylene-vinyl acetate copolymer saponified resin. 7. The multilayer laminate according to claim 6, wherein the saponified ethylene-vinyl acetate copolymer resin contains 15 mol% or more of ethylene units and has a saponification degree of 90 mol% or more.