JP2000198173A - Gas barrier laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier laminated film not damaging excellent barrier properties, good in bending resistance, having strength characteristics capable of sufficiently withstanding a falling impact and also excellent in heat sealability. SOLUTION: An adhesion modified layer 2 containing a self-crosslinkable polyester graft copolymer obtained by the graft copolymerization of a polymerizable unsaturated monomer containing a polymerizable unsaturated monomer having hydrophilicity with a hydrophobic polyester resin as a constitutional component, a gas barrier layer 3 comprising a metal oxide membrane layer, a thermosetting resin layer 4 and a heat-sealing layer are successively laminated on one A-layer or both A-layers of a laminated polyamide film 1 having layered constitution of A/B or A/B/A. Herein, the A-layer comprises a compsn. composed of a mixed polymer and/or a copolymer of 10 mol% or more of an aromatic polyamide resin component consisting of terephthalic acid and/or isophthalic acid and aliphatic diamine and 90 mol% or less of an aliphatic polyamide resin component and the B-layer comprises a compsn. composed of an aliphatic polyamide resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas-barrier laminated film, particularly excellent in gas-barrier properties and moisture-proof properties, which are important properties in packaging films for fresh foods, processed foods, pharmaceuticals, medical equipment, electronic parts and the like. And a laminated film or sheet excellent in transparency and handleability (hereinafter represented by a film).

[0002]

2. Description of the Related Art In recent years, food packaging forms have changed drastically due to changes in food distribution forms and dietary habits, and the required characteristics of packaging films have become increasingly severe.

[0003] Temperature, moisture, oxygen,
Deterioration of the quality of products due to ultraviolet rays and the influence of microorganisms such as bacteria and mold is a serious problem not only in terms of sales but also in terms of food hygiene. As a method of preventing such quality deterioration, antioxidants and preservatives have been added directly to foods in the past, but recently, from the viewpoint of hygiene, reduction or no addition of food additives has been required. Is required,
Under such circumstances, there has been an increasing demand for packaging films that have low gas and moisture permeability and do not cause deterioration in quality as food even by freezing, boiling, retorting, and the like.

[0004] That is, in the packaging of fish meat, animal meat, shellfish and the like, it is important to suppress the oxidation and alteration of proteins and oils and fats, and to maintain the taste and freshness. It is desirable to use it to block air permeation. Moreover, when wrapped in a gas barrier film, the fragrance of the contents is retained and the permeation of moisture is prevented, so that the moisture absorption of dried products is suppressed, and the deterioration and solidification due to evaporation of moisture is suppressed in the case of hydrated products. In addition, it is possible to maintain a fresh flavor during packaging for a long time.

For these reasons, kneaded products such as kamaboko, dairy products such as butter and cheese, miso, tea, coffee,
In a packaging film for confectionery such as ham / sausage, instant food, castella, biscuit, etc., the gas barrier properties and moisture resistance are extremely important properties.
These properties are not limited to a film for food packaging, but are extremely important as a packaging film for pharmaceuticals that need to be handled under aseptic conditions or electronic components that require rust prevention.

As a film having excellent gas barrier properties,
Known are those in which a metal foil such as aluminum is laminated on a plastic film, and those in which vinylidene chloride or an ethylene vinyl alcohol copolymer is coated. Further, as a device using a metal oxide thin film, a device in which a deposited film of silicon oxide, aluminum oxide, or the like is laminated on a plastic film is also known.

[0007] In practice, a polyamide film is laminated by providing a print layer and an adhesive layer and then providing a sealant layer by a dry lamination method or a sealant layer by an extrusion lamination method. Body, make a bag using the laminate, fill the contents and heat seal the opening, for example, seasonings such as miso and soy sauce, packaging containing water-containing foods such as soups and retort foods or chemicals Offering to the general consumer.

The following problems have been pointed out in the above-mentioned conventional gas barrier films. Aluminum foil laminated as a gas barrier layer is excellent in economics and gas barrier properties, but is opaque, so the contents cannot be seen when packaged, and it does not transmit microwaves, so it can not be processed with a microwave oven .

Further, a film coated with vinylidene chloride or an ethylene vinyl alcohol copolymer does not have sufficient gas barrier properties against water vapor, oxygen, etc., and its performance is significantly deteriorated particularly by high-temperature treatment. In addition, a film coated with a vinylidene chloride resin may cause air pollution due to generation of chlorine gas during incineration.

Therefore, a plastic film having a thin film layer of a metal oxide such as silicon oxide or aluminum oxide formed as a gas barrier layer has been proposed. As a base film for depositing silicon oxide, aluminum oxide, or the like, a biaxially stretched polyethylene terephthalate film (PET) having good dimensional stability has conventionally been used.

The laminated structure is usually a laminated structure such as PET / metal oxide thin film layer / adhesive layer / PET / adhesive layer / unstretched polypropylene (CPP). In the case of the film described above, insufficient strength against a drop impact becomes a problem.

On the other hand, in the case of a laminated structure such as PET / metal oxide thin film layer / adhesive layer / stretched nylon (ONY) / adhesive layer / unstretched polypropylene (CPP), the shrinkage of nylon causes a boiling or retorting treatment. There is a problem that the gas barrier property is deteriorated.

[0013] Therefore, a film laminated with nylon having a reduced shrinkage during high-temperature hot water treatment (Japanese Patent Laid-Open No. 7-27657).
No. 1) has been proposed. However, since the number of films to be laminated increases, the manufacturing process and the process of transport and storage become complicated, resulting in poor economic efficiency, and the thicker film makes handling difficult, which is not practical.

A gas barrier film using a nylon film as an inorganic vapor-deposited substrate has been studied. However, the nylon film has a large dimensional change due to moisture absorption and heating, so that the barrier property is unstable, and especially after a boiling treatment or a retort treatment. However, there arises a problem that the gas barrier property is deteriorated.

As a measure for improving the gas barrier property, a laminated film (JP-B-7-12649) using a stretched nylon film whose shrinkage has been reduced in advance by heat treatment as a base material for forming a metal oxide thin film layer has been proposed. Proposed. However, the manufacturing process and the transportation and storage processes become complicated, which is not practical. In addition, nylon having a small shrinkage ratio at the time of high-temperature treatment (in Japanese Patent Publication No. Hei 7-12649, the sum of absolute values of dimensional changes in the vertical and horizontal directions when heated at 120 ° C. for 5 minutes is 2% or less). Even so, excellent gas barrier properties cannot be maintained by boiling treatment, which is high-temperature hot water treatment.

When a nylon film is used as a base film for forming a metal oxide thin film, if water enters between the nylon film and the metal oxide thin film layer, the adhesive strength between the layers is significantly reduced, and It is thought that when used as a material, it not only causes rupture but also leads to a decrease in gas barrier properties.

As described above, it is pointed out that a gas barrier film having a laminated structure provided with a metal oxide thin film layer of silicon oxide, aluminum oxide, or the like does not always have sufficient strength, and that the gas barrier property deteriorates due to boiling treatment or retort treatment. ing.

In addition, Japanese Patent Publication No. 51-48511 discloses a gas barrier film that is transparent, allows the contents to be seen through, and is applicable to a microwave oven. Si
O ₂ ) has been proposed. However, a SiOx-based gas (x =
1.3-1.8) The deposited film has a slightly brown color, and cannot be said to be sufficient in quality as a transparent gas barrier film.

Japanese Patent Application Laid-Open No. 62-101428 describes a gas barrier film provided with a metal oxide thin film layer mainly composed of aluminum oxide. However, this film has insufficient gas barrier properties. In addition, there is a problem of bending resistance.

[0020] Although some are proposed in JP-A 2-194944 discloses as Al ₂ O ₃ · SiO ₂ vapor-deposited layer as a gas barrier layer having boiling resistance and retort resistance, Al ₂ O ₃ and SiO _In this case, the formation of the scum barrier layer is complicated and requires a large-scale apparatus. In addition, films using these metal oxide thin films as gas barrier layers are still inadequate from the viewpoint of achieving both gas barrier properties and flex resistance. That is, in order to provide excellent boiling resistance and retort resistance,
Although a film thickness of a certain level or more (for example, about 2,000 mm or more) is required, if the film thickness is large, there is a problem that the bending resistance is deteriorated and it cannot withstand a drop impact. A gas barrier film which is excellent in boiling resistance and retort resistance, has excellent bending resistance, and can sufficiently withstand a drop impact has not yet been proposed. Further, when printing with ink, there is a concern that the metal oxide thin film layer may be damaged and the gas barrier property may be reduced.

[0021]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the conventional gas barrier laminated film, has excellent transparency, gas barrier properties and adhesiveness, and can be used even after a boiling process or an ink printing process. It economically provides a gas barrier laminated film that does not impair its excellent barrier properties, has good bending resistance, has sufficient strength characteristics to withstand drop impacts, and also has excellent heat sealing properties. The purpose is to:

[0022]

Means for Solving the Problems In order to achieve the above object, a gas barrier laminated film of the present invention comprises one of the following compositions, and is one of laminated polyamide films having an A / B or A / B / A layer constitution. Or a self-crosslinkable polyester graft obtained by graft copolymerizing a polymerizable unsaturated monomer containing a polymerizable unsaturated monomer having hydrophilicity onto a hydrophobic polyester resin on both A layers. It is characterized in that an adhesion reforming layer comprising a copolymer as a component, a gas barrier layer comprising a metal oxide thin film layer, a thermosetting resin layer and a heat sealing layer are sequentially laminated. -Polyamide resin composition forming A layer (X) component: 10 mol% or more of aromatic polyamide resin component (a) composed of terephthalic acid and / or isophthalic acid and aliphatic diamine and aliphatic polyamide resin component ( b) Composition comprising a mixed polymer and / or copolymer with 90 mol% or less-Polyamide-based resin composition forming B layer Composition composed of aliphatic polyamide-based resin

The gas-barrier laminated film of the present invention having the above-mentioned structure has excellent gas-barrier properties and adhesion even at the initial stage and after the boil treatment, and has excellent transparency and pinhole resistance. Film.

In this case, the polyamide resin composition forming the layer A comprises the component (X): terephthalic acid and / or
Alternatively, 100% by weight of a mixed polymer and / or copolymer of an aromatic polyamide-based resin component (a) composed of isophthalic acid and an aliphatic diamine of 10 mol% or more and an aliphatic polyamide-based resin component (b) of 90 mol% or less. (Y) component:
It can be a composition containing 100 parts by weight or less of the aliphatic polyamide-based resin.

In this case, the polyamide-based resin composition forming the layer A is composed of 10 moles of the component (X): an aromatic polyamide-based resin component (a) composed of terephthalic acid and / or isophthalic acid and an aliphatic diamine. % Or less and 20 parts by weight or less of an aliphatic polyamide-based resin component (b), and 100 parts by weight of a copolymer of the mixed polymer and / or copolymer of the aliphatic polyamide-based resin component (b). Composition.

In this case, the adhesion modifying layer is
A coating solution containing a self-crosslinkable polyester-based graft copolymer is applied to an unstretched or uniaxially stretched film, and after drying, the film is further stretched uniaxially or more, and formed by heat fixing. There can be.

In this case, the polymerizable unsaturated monomer having hydrophilicity can be an acid anhydride having a double bond.

In this case, the acid anhydride having a double bond may contain maleic anhydride.

In this case, the polymerizable unsaturated monomer may contain styrene.

In this case, the gas barrier layer composed of the metal oxide thin film layer can be a thin film composed of a mixture of silicon oxide and aluminum oxide.

In this case, the gas barrier layer composed of a metal oxide thin film layer can contain 95 to 55% by weight of silicon oxide and 5 to 45% by weight of aluminum oxide.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the gas barrier laminate film of the present invention will be described.

In the present invention, the film constituting the base layer of the gas-barrier laminated film is a laminated polyamide film having the following composition and having an A / B or A / B / A layer constitution.

Here, as the polyamide resin composition for forming the layer A of the laminated polyamide film constituting the base layer, the following compositions can be shown. i) Component (X): a mixture of an aromatic polyamide resin component (a) composed of terephthalic acid and / or isophthalic acid and an aliphatic diamine of 10 mol% or more and an aliphatic polyamide resin component (b) of 90 mol% or less. Ii) Component (Y) based on 100 parts by weight of component (X), wherein the composition comprises a polymer and / or a copolymer.
A composition containing 100 parts by weight or less of an aliphatic polyamide-based resin component iii) Component (Z) with respect to 100 parts by weight of component (X):
Composition containing 20 parts by weight or less of flex fatigue resistance improving agent iv) Composition containing 100 parts by weight or less of component (Y) and 20 parts by weight or less of component (Z) per 100 parts by weight of component (X) object

The component (X) of the present invention comprises at least 10% by mole of an aromatic polyamide resin component (a) comprising terephthalic acid and / or isophthalic acid and an aliphatic diamine having 6 to 12 carbon atoms. A composition comprising a mixed polymer and / or copolymer with an aliphatic polyamide resin component (b) of 90 mol% or less, comprising terephthalic acid and / or isophthalic acid and an aliphatic diamine having 6 to 12 carbon atoms. Of aromatic polyamide-based resin and aliphatic polyamide-based resin comprising: aromatic polyamide-based resin unit comprising terephthalic acid and / or isophthalic acid and aliphatic diamine having 6 to 12 carbon atoms; and aliphatic polyamide-based resin Block copolymer or random copolymer comprising resin units, or terephthalic acid and / or isophthalic acid and carbon number 6
And a mixed polymer of an aliphatic polyamide-based resin and a block copolymer or random copolymer composed of an aromatic polyamide-based resin unit and an aliphatic polyamide-based resin unit composed of an aliphatic diamine of 1 to 12 and an aliphatic polyamide-based resin unit.

The aromatic polyamide resin component (a) used in the present invention is a polymer comprising terephthalic acid and / or isophthalic acid and an aliphatic diamine having 6 to 12 carbon atoms.

Further, (X) used in the present invention
Aliphatic polyamide resin component (b) constituting the component,
Examples of the aliphatic polyamide resin used to constitute the component (Y) and the layer B include nylon 4, nylon 6, nylon 7, nylon 11, nylon 12, and nylon 6.
6, nylon 612, nylon 46, and their copolymers and mixed polymers. Nylon 6 and nylon 66 are preferred.

The flex fatigue resistance improving agent (Z) used in the present invention comprises a block polyesteramide elastomer, a block polyetheramide elastomer,
Block polyetheresteramide elastomer,
It can be composed of one or more selected from elastomers such as block polyetherester elastomers, block polyester elastomers, modified ethylene propylene rubbers, modified acrylics, and ethylene acrylate copolymers.

Further, in the present invention, the polyamide resin composition constituting the laminated polyamide film of the base layer is mainly composed of an aliphatic polyamide resin. Examples of the aliphatic polyamide-based resin are as described above.

The laminated polyamide film having the A / B or A / B / A layer constitution used for forming the gas barrier laminated film of the present invention can be produced by a known production method. That is, the polymer constituting each layer is melted using a separate extruder, a method of manufacturing by co-extrusion, a method of laminating a film made of the polymer constituting each layer by lamination, a method of combining these, and the like. Can be taken. Further, the above-mentioned laminated polyamide film can be used as either an unstretched film or a stretched film, but it is preferable to stretch and use it in a uniaxial or biaxial direction in order to improve the processability of the film. As the stretching method, a known method such as a tenter-type sequential biaxial stretching method, a tenter-type simultaneous biaxial stretching method, and a tubular method can be used. The purpose of the laminated polyamide film used in the present invention, various additives as long as the performance is not impaired, for example, a lubricant, an antioxidant,
A weathering agent, an anti-gelling agent, an anti-blocking agent, a pigment, an antistatic agent and the like may be appropriately blended.

The gas-barrier laminated film of the present invention is provided on at least one surface of the laminated polyamide film.
A self-crosslinkable polyester-based graft copolymer obtained by graft-polymerizing a polymerizable unsaturated monomer containing a polymerizable unsaturated monomer having a hydrophilic property onto a hydrophobic polyester-based resin is used as a component. In addition to the formation of the adhesion reforming layer, a gas barrier layer made of a metal oxide thin film, a thermosetting resin layer, and a heat sealing layer are sequentially formed on at least one of the adhesion reforming layers.

In order to form the adhesion modified layer, an organic solvent solution or dispersion or an aqueous solvent solution or dispersion of the self-crosslinkable polyester-based graft copolymer constituting the adhesion modified layer is applied to the laminated polyamide film. It is preferably used as a liquid.

The self-crosslinkable polyester-based graft copolymer used in the present invention is obtained by graft-copolymerizing a polymerizable unsaturated monomer containing a polymerizable unsaturated monomer having hydrophilicity to a hydrophobic polyester-based resin. It was obtained.

In order to carry out graft copolymerization to obtain the self-crosslinkable polyester-based graft copolymer used in the present invention, generally, a radical initiator is dissolved in a state where a hydrophobic polyester-based resin is dissolved in an organic solvent. And a mixture of a polymerizable unsaturated monomer and a polymerizable unsaturated monomer. The reaction product after the completion of the grafting reaction is, in addition to the graft polymer between the desired hydrophobic polyester-based resin-polymerizable unsaturated monomer mixture, the hydrophobic polyester-based resin that has not been grafted and the hydrophobic polymer. Although it contains a radical polymer that has not been grafted to the polyester resin, the self-crosslinkable polyester graft copolymer in the present invention includes all of them. Here, the term "grafting" refers to introducing a branch polymer made of a polymer different from the main chain into the main chain of the main polymer.

In the present invention, the acid value of the self-crosslinkable polyester graft copolymer obtained by graft copolymerizing a polymerizable unsaturated monomer with a hydrophobic polyester resin is 60.
It is preferably 0 eq / 10 ⁶ g or more. More preferably, the acid value is 1200 eq / 10 ⁶ g or more. When the acid value of the reactant is less than 600 eq / 10 ⁶ g,
The object of the present invention is that the adhesion to the gas barrier layer composed of an inorganic thin film is not sufficient.

The weight ratio between the hydrophobic polyester resin and the polymerizable unsaturated monomer, which is suitable for the purpose of obtaining the gas barrier laminate film of the present invention, is determined as follows: hydrophobic polyester resin / polymerizable unsaturated monomer. Monomer = 40 / 60-9
The range of 5/5 is desirable, and more preferably 55 / 45-55.
93/7, most preferably in the range of 60/40 to 90/10.

When the above-mentioned weight ratio of the hydrophobic polyester resin is less than 40% by weight, the adhesion-modified layer containing the self-crosslinkable polyester-based graft copolymer as a component may exhibit excellent adhesion. Can not. On the other hand, when the weight ratio of the hydrophobic polyester-based resin is more than 95% by weight, the adhesion-modified layer containing the self-crosslinkable polyester-based graft copolymer as a component tends to cause blocking.

The self-crosslinkable polyester-based graft copolymer used in the present invention is in the form of a solution or dispersion with an organic solvent or a solution or dispersion with an aqueous solvent. In particular, a dispersion of the self-crosslinkable polyester-based graft copolymer in an aqueous solvent, that is, a form of a water-dispersed resin (hereinafter, may be simply referred to as “water-dispersed resin”) is preferable in terms of working environment and applicability. In order to obtain such a water-dispersed resin, usually, in an organic solvent, the polymerizable unsaturated monomer having a polymerizable unsaturated monomer having hydrophilicity is graft-polymerized to the hydrophobic polyester-based resin. And then adding water and further distilling off the organic solvent.

The water-dispersed resin for producing the gas barrier laminate film of the present invention has an average particle diameter of usually 500 nm or less as measured by a laser light scattering method, and has a translucent or milky white appearance. By adjusting the polymerization reaction, water-dispersed resins having various particle diameters can be obtained. The particle diameter is suitably from 10 to 500 nm, and from the viewpoint of dispersion stability, is preferably 400 nm or less, more preferably 300 nm or less.
nm or less. If the particle size of the water-dispersed resin exceeds 500 nm, the gloss of the coating film surface tends to decrease, and the transparency of the coating tends to decrease. On the other hand, if the particle size of the water-dispersed resin is less than 10 nm, the water resistance, which is the object of the present invention, tends to decrease, which is not preferable.

The hydrophobic polyester resin used in the present invention must be essentially water-insoluble, which does not disperse or dissolve in water by itself. When a polyester resin dispersed or dissolved in water is used for graft polymerization, the adhesiveness and water resistance of the object of the present invention are deteriorated,
Not practical.

The composition of the dicarboxylic acid component of the hydrophobic polyester resin is usually from 60 to 9 aromatic dicarboxylic acids.
9.5 mol%, aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid 0 to 40 mol%, dicarboxylic acid containing a polymerizable unsaturated double bond as a polymerizable unsaturated monomer 0.5
It is preferably from 10 to 10 mol%.

When the content of the aromatic dicarboxylic acid is less than 60 mol% or when the content of the aliphatic dicarboxylic acid and / or the alicyclic dicarboxylic acid exceeds 40 mol%, the adhesive strength tends to decrease. Further, when the amount of the dicarboxylic acid containing a polymerizable unsaturated double bond is less than 0.5 mol%, efficient grafting of the polymerizable unsaturated monomer to the hydrophobic polyester resin becomes difficult, and On the other hand, if it exceeds 10 mol%, the viscosity is unduly increased too late in the latter stage of the grafting reaction, which hinders the uniform progress of the reaction. More preferably, the aromatic dicarboxylic acid is 70-98 mol%,
Aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid 0
It is a polyester of 30 mol% and 2 to 7 mol% of dicarboxylic acid containing a polymerizable unsaturated double bond.

Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid and the like. It is preferable to use a dicarboxylic acid having a hydrophilic group such as 5-sodium sulfoisophthalic acid in terms of reducing the water resistance, which is the object of the present invention. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecandionic acid, and dimer acid.Examples of the alicyclic dicarboxylic acid include 1,4-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid. Examples thereof include 3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, and acid anhydrides thereof.

Examples of dicarboxylic acids containing a polymerizable unsaturated double bond include, as α, β-unsaturated dicarboxylic acids, fumaric acid, maleic acid, maleic anhydride, itaconic acid, citraconic acid, unsaturated double acids. Examples of the alicyclic dicarboxylic acid having a bond include 2,5-norbornene dicarboxylic anhydride, tetrahydrophthalic anhydride and the like. Of these, fumaric acid, maleic acid, and 2,5-norbornene dicarboxylic acid are preferred from the viewpoint of polymerizability.

On the other hand, the glycol component of the hydrophobic polyester resin is usually preferably composed of an aliphatic glycol having 2 to 10 carbon atoms, an alicyclic glycol having 6 to 12 carbon atoms and / or an ether bond-containing glycol. Examples of the aliphatic glycol having 2 to 10 carbon atoms include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, Examples thereof include 6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, and 2-ethyl-2-butylpropanediol, and have 6 to 1 carbon atoms.
Examples of the alicyclic glycol 2 include 1,4-cyclohexanedimethanol.

Examples of the glycol containing an ether bond include diethylene glycol, triethylene glycol, dipropylene glycol, and glycols obtained by adding ethylene oxide or propylene oxide to two phenolic hydroxyl groups of bisphenols, for example, 2,2. -Bis (4-hydroxyethoxyphenyl) propane and the like. Polyether glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol can also be used if necessary.

In the hydrophobic polyester resin used in the present invention, 0 to 5 mol% of a trifunctional or higher polycarboxylic acid and / or polyol can be copolymerized. Examples of the trifunctional or higher polycarboxylic acid include trimellitic acid (anhydride), pyromellitic acid (anhydride), benzophenonetetracarboxylic acid (anhydride), trimesic acid, ethylene glycol bis (anhydrotrimellitate), and glycerol tris. (Anhydrotrimellitate) or the like is used. On the other hand, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like are used as the trifunctional or higher polyol. The tri- or higher functional polycarboxylic acid and / or polyol is copolymerized in an amount of 0.01 to 5 mol%, preferably 0.01 to 3 mol%, based on the total acid content or all glycol components. %, Gelation during polymerization tends to occur, which is not preferable.

The molecular weight of the hydrophobic polyester resin is preferably in the range of 5,000 to 50,000 on the weight average. When the molecular weight is less than 5,000, the adhesive strength is reduced, while when it exceeds 50,000, problems such as gelation during polymerization occur.

Examples of polymerizable unsaturated monomers suitable for graft copolymerization with a hydrophobic polyester resin used in the present invention include fumaric acid, monoethyl fumarate, diethyl fumarate, dibutyl fumarate and the like. Monoester or diester of fumaric acid, maleic acid and its anhydride, monoethyl maleate, diethyl maleate,
Monoester or diester of maleic acid such as dibutyl maleate, itaconic acid and its anhydride, monoester or diester of itaconic acid, maleimide such as phenylmaleimide, styrene, α-methylstyrene, t-butylstyrene, chloro Styrene derivatives such as methylstyrene, vinyltoluene, divinylbenzene and the like. In addition, acrylic polymerizable monomers include, for example, alkyl acrylate, alkyl methacrylate (the alkyl group is a methyl group, an ethyl group, an n-propyl group,
so-propyl group, n-butyl group, iso-butyl group,
t-butyl group, 2-ethylhexyl group, cyclohexyl group, phenyl group, benzyl group, phenylethyl group, etc.);
2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, hydroxy-containing acrylic monomer of 2-hydroxypropyl methacrylate; acrylamide, methacrylamide, N-methylmethacrylamide, N-methylacrylamide, N-methylo -Acrylic monomers containing an amide group of -acrylamide, N-methylolmethacrylamide, N, N-dimethylolacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N-phenylacrylamide; An amino group-containing acrylic monomer of -diethylaminoethyl acrylate or N, N-diethylaminoethyl methacrylate;
Glycidyl acrylate, epoxy group-containing acrylic monomer of glycidyl methacrylate; acrylic monomers containing a carboxyl group or a salt thereof such as acrylic acid, methacrylic acid and / or their salts (sodium salt, potassium salt, ammonium salt); Can be Preferred are maleic anhydride and its esters. One or more of the above monomers can be copolymerized.

Among the above polymerizable unsaturated monomers, the “polymerizable unsaturated monomer having hydrophilicity” is a polymer having a hydrophilic group or a group having a group which can be converted into a hydrophilic group later. Refers to the unsaturated monomer. Examples of the polymerizable unsaturated monomer having a hydrophilic group include a polymerizable unsaturated monomer containing a carboxyl group, a hydroxyl group, a phosphoric acid group, a phosphorous acid group, a sulfonic acid group, an amide group, a quaternary ammonium base, and the like. Can be mentioned. On the other hand, examples of the polymerizable unsaturated monomer that can be converted into a hydrophilic group include an acid anhydride group, a glycidyl group, and a chloro group. Among these, a carboxyl group is preferable from the viewpoint of imparting water dispersibility, and a polymerizable unsaturated monomer having a carboxyl group or a group capable of changing to a carboxyl group is preferable.
Particularly preferred is a polymerizable unsaturated monomer comprising an acid anhydride having a double bond.

The graft polymerization performed in the present invention is generally carried out by reacting a radical initiator and a polymerizable unsaturated monomer mixture in a state where a hydrophobic polyester resin is dissolved in an organic solvent. . As the graft polymerization initiator used in the present invention, organic peroxides and organic azo compounds known to those skilled in the art can be used.

Benzoyl peroxide, t-butyl peroxybivalate as an organic peroxide, 2,2′-azobisisobutyronitrile as an organic azo compound,
2,2-azobis (2,4-dimethylvaleronitrile)
And the like. The amount of the polymerization initiator used for performing the graft polymerization is at least 0.2% by weight, preferably 0.5% by weight or more, based on the polymerizable monomer.

In addition to the polymerization initiator, a chain transfer agent for adjusting the chain length of the branched polymer, for example, octyl mercaptan, mercaptoethanol, 3-t-butyl-4-hydroxyanisole, etc. can be used as required. In this case, it is preferable to add in the range of 0 to 5% by weight based on the polymerizable monomer.

The grafting reaction solvent for obtaining the self-crosslinkable polyester-based graft copolymer used for producing the film of the present invention is preferably composed of an aqueous organic solvent having a boiling point of 50 to 250 ° C. Here, the aqueous organic solvent has a solubility in water at 20 ° C. of at least 1
0 g / liter or more, preferably 20 g / liter or more. Those having a boiling point exceeding 250 ° C. are unsuitable because the evaporation rate is too slow and cannot be sufficiently removed even by baking the coating film at a high temperature. When the boiling point is lower than 50 ° C., when a grafting reaction is carried out using the solvent as a solvent, an initiator that cleaves into radicals at a temperature lower than 50 ° C. must be used, so that the danger in handling increases, which is not preferable. . Comparing polymerizable unsaturated monomers that dissolve hydrophobic polyester resin well and contain hydrophilic polymerizable unsaturated monomers, especially acid anhydrides with double bonds, and their polymers Examples of the first group of aqueous organic solvents that dissolve well include esters, for example, ethyl acetate, ketones, for example, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclic ethers, for example, tetrahydrofuran, dioxane,
1,3-dioxolane, glycol ethers such as ethylene glycol dimethyl ether, propylene glycol methyl ether, propylene glycol propyl ether, ethylene glycol ethyl ether, ethylene glycol butyl ether, carbitols such as methyl carbitol, ethyl carbitol, butyl carbitol, glycol Or lower esters of glycol ethers such as ethylene glycol diacetate, ethylene glycol ethyl ether acetate, ketone alcohols such as diacetone alcohol, and N-
Substituted amides such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like can be exemplified.

On the other hand, water and lower alcohols are a second group of aqueous organic solvents which hardly dissolve the hydrophobic polyester resin but relatively well dissolve the hydrophilic polymerizable monomer mixture and its polymer. , Lower carboxylic acids,
Although lower amines and the like can be mentioned, alcohols and glycols having 1 to 4 carbon atoms are particularly preferable for the practice of the present invention.

When the grafting reaction is performed in a single solvent,
One kind of solvent can be selected from the first group of aqueous organic solvents. When using a mixed solvent, there are a case where a plurality of types are selected from the first group of aqueous organic solvents, and a case where at least one type is selected from the first group of aqueous organic solvents and at least one type is added from the second group of aqueous organic solvents.

In both cases where the graft polymerization reaction solvent is a single solvent from the first group of aqueous organic solvents, and when it is a mixed solvent composed of one kind of each of the first and second groups of aqueous organic solvents. A graft polymerization reaction can be performed. However, the progress of the grafting reaction, the appearance of the grafting reaction product and the aqueous dispersion derived therefrom,
Differences are observed in properties and the like, and it is preferable to use a mixed solvent composed of one kind of each of the first group and the second group of aqueous organic solvents.

In the solvent of the first group, the molecular chain of the hydrophobic polyester resin is in a state of a widened chain.
On the other hand, in the mixed solvent of the first group / second group, it was confirmed by the viscosity measurement of the copolymerized polyester in these solutions that the co-polyester was in a state of being entangled in a small spread thread. It is effective to prevent gelation by adjusting the dissolution state of the hydrophobic polyester-based resin so as to prevent intermolecular crosslinking. Both high efficiency of grafting and suppression of gelation are achieved in the latter mixed solvent system. The weight ratio of the mixed solvent of the first group / second group is more preferably 95/5 to 10/90, further preferably 90/10 to 20/80, and most preferably 85 /.
It is in the range of 15 to 30/70. The optimum mixing ratio is determined according to the solubility of the polyester used.

The product of the grafting reaction according to the present invention is preferably neutralized with a basic compound, and can be easily dispersed in water by neutralization. As the basic compound, a compound which volatilizes at the time of forming a coating film or at the time of baking and curing with a curing agent is desirable, and ammonia, organic amines and the like are preferable. Examples of desirable compounds include triethylamine, N, N-diethylethanolamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminopispropylamine,
Ethylamine, diethylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-
Examples thereof include butylamine, propylamine, methylaminopropylamine, dimethylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine, and triethanolamine. The basic compound has a pH value of the aqueous dispersion in the range of 5.0 to 9.0 by at least partial neutralization or complete neutralization depending on the carboxyl group content contained in the grafting reaction product. It is desirable to use it as it is. If a basic compound having a boiling point of 100 ° C. or lower is used, the residual basic compound in the coating film after drying is small, and the adhesion to a metal or an inorganic vapor-deposited film, or the water resistance or hot water resistance of the laminate. Excellent adhesion.

In the water-dispersible resin produced according to the present invention, the polymer of the polymerizable unsaturated monomer has a weight average molecular weight of 5
It is preferably from 00 to 50,000. It is generally difficult to control the weight average molecular weight of the polymer of the polymerizable unsaturated monomer to less than 500, the graft efficiency is reduced, and the hydrophilic group is sufficiently imparted to the hydrophobic polyester resin. There is no tendency. In addition, the self-crosslinkable polyester-based graft copolymer obtained by graft polymerization of the polymerizable unsaturated monomer forms a hydrated layer of dispersed particles, but has a hydrated layer of a sufficient thickness, and is stable. In order to obtain a dispersion, the weight average molecular weight of the graft polymer of the polymerizable unsaturated monomer is desirably 500 or more. Further, the upper limit of the weight average molecular weight of the graft polymer of the polymerizable unsaturated monomer is preferably 50,000 from the viewpoint of solution polymerization. The control of the molecular weight within this range can be carried out by appropriately combining the amount of the polymerization initiator, the monomer dropping time, the polymerization time, the reaction solvent, the monomer composition or, if necessary, a chain transfer agent and a polymerization inhibitor.

In the present invention, a reaction product obtained by graft-polymerizing a polymerizable unsaturated monomer onto a hydrophobic polyester resin has a self-crosslinking property. Although it does not crosslink at room temperature, it undergoes an intermolecular reaction such as 1) a dehydration reaction of silanol groups present in the reaction product and 2) a hydrogen abstraction reaction by a thermal radical by heat during drying, and crosslinks without a crosslinking agent. Thereby, the adhesiveness and water resistance, which are the objects of the present invention, can be expressed for the first time.
The crosslinkability of the coating film can be evaluated by various methods,
It can be determined by the insoluble fraction in a chloroform solvent that dissolves both the hydrophobic polyester-based resin and the self-crosslinkable polyester-based graft copolymer obtained by graft polymerization of the polymerizable unsaturated monomer. The insoluble content of the coating film obtained by drying the coating layer at 80 ° C. or less and heat-treating at 120 ° C. for 5 minutes is preferably 50% or more, more preferably 70% or more.
% Or more. If the insoluble content of the coating is less than 50%,
Not only is the adhesive property and water resistance of the adhesion modified layer insufficient, but also blocking may occur.

The above-mentioned self-crosslinkable polyester-based graft copolymer can form the adhesion-modified layer constituting the present invention as it is, but it is necessary to further cure by adding a crosslinking agent (curing resin). Thereby, a high degree of water resistance can be imparted to the adhesion modified layer.

Examples of the cross-linking agent include phenol-formaldehyde resins which are condensates of alkylated phenols and cresols with formaldehyde; adducts of urea, melamine, benzoguanamine and the like with formaldehyde, and adducts having 1 to 1 carbon atoms. An amino resin such as an alkyl ether compound comprising alcohol 6; a polyfunctional epoxy compound; a polyfunctional isocyanate compound; a blocked isocyanate compound; a polyfunctional aziridine compound;
Any material such as an oxazoline compound can be used.

As the phenol formaldehyde resin, for example, alkylated (methyl, ethyl, propyl,
Isopropyl or butyl) phenol, p-tert-
Amylphenol, 4,4'-sec-butylidenephenol, p-tert-butylphenol, o-, m-
Or p-cresol, p-cyclohexylphenol,
4,4′-isopropylidenephenol, p-nonylphenol, p-octylphenol, 3-pentadecylphenol, phenol, phenyl o-cresol, p
-Condensates of phenols such as phenylphenol and xylenol with formaldehyde.

Examples of the amino resin include methoxylated methylol urea, methoxylated methylol N, N-ethylene urea, methoxylated methylol dicyandiamide, methoxylated methylol melamine, methoxylated methylol benzoguanamine, butoxylated methylol melamine, butoxylated methylol benzoguanamine. And methoxylated methylolmelamine, butoxylated methylolmelamine, and methylolated benzoguanamine.

Examples of the polyfunctional epoxy compound include diglycidyl ether of bisphenol A and its oligomer, diglycidyl ether of hydrogenated bisphenol A and its oligomer, diglycidyl orthophthalate, and diglycidyl isophthalate.
Diglycidyl terephthalate, diglycidyl p-oxybenzoate, diglycidyl tetrahydrophthalate, diglycidyl hexahydrophthalate, diglycidyl succinate, diglycidyl adipate, diglycidyl sebacate, ethylene Glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether and polyalkylene glycol diglycidyl ethers, trimellitic acid triglycidyl ester, triglycidyl isocyanurate ,
1,4-diglycidyloxybenzene, diglycidylpropylene urea, glycerol triglycidyl ether,
Examples thereof include trimethylolpropane triglycidyl ether, pentaerythritol triglycidyl ether, and triglycidyl ether of a glycerol alkylene oxide adduct.

Examples of the polyfunctional isocyanate compound include:
Low molecular or high molecular aromatic or aliphatic diisocyanates and trivalent or higher polyisocyanates can be used. Examples of the polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and trimers of these isocyanate compounds. Further, excess amounts of these isocyanate compounds, ethylene glycol, propylene glycol, trimethylolpropane,
Terminals obtained by reacting with low-molecular-weight active hydrogen compounds such as glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, and triethanolamine, or high-molecular-weight active hydrogen compounds such as polyester polyols, polyether polyols, and polyamides. An isocyanate group-containing compound can be mentioned.

The blocked isocyanate can be prepared by subjecting the above isocyanate compound and a blocking agent to an addition reaction by a conventionally known appropriate method. Examples of the isocyanate blocking agent include phenols such as phenol, cresol, xylenol, resorcinol, nitrophenol, and chlorophenol; thiophenols such as thiophenol and methylthiophenol; oximes such as acetoxime, methyl etiketoxime, and cyclohexanone oxime. Alcohols such as methanol, ethanol, propanol and butanol; ethylene chlorohydrin, 1,3-dichloro-2-
Halogen-substituted alcohols such as propanol; tertiary alcohols such as t-butanol and t-pentanol; lactams such as ε-caprolactam, δ-palerolactam, ν-butyrolactam, β-propyl lactam; aromatic amines; Imides; active methylene compounds such as acetylacetone, acetoacetic ester, and malonic acid ethyl ester; mercaptans; imines; ureas;
Diaryl compounds; sodium bisulfite and the like.

These crosslinking agents can be used alone or in combination.
A mixture of more than one species can be used. The amount of the crosslinking agent to be used is as follows: self-crosslinkable polyester-based graft copolymer 1
5 to 40 parts by weight to 00 parts by weight is preferred. As a method of compounding the crosslinking agent, (1) when the crosslinking agent is water-soluble, a method of directly dissolving or dispersing it in an aqueous solvent solution or dispersion of the graft copolymer, or (2) an oil-soluble crosslinking agent. In some cases, after the completion of the grafting reaction, there is a method of adding to the reaction solution. These methods can be appropriately selected depending on the type and properties of the crosslinking agent. Further, a curing agent or an accelerator can be used in combination with the crosslinking agent.

The coating solution containing the self-crosslinkable polyester-based graft copolymer can be used as it is to form the adhesion-modified layer of the gas barrier laminate film of the present invention. Resins, urethane resins, acrylic resins, their copolymers, various water-soluble resins and various functional resins, such as conductive resins such as polyaniline and polypyrrole, antibacterial resins, ultraviolet absorbing resins, and gas barrier resins Can be used to form an adhesion-modified layer. In the present invention, a coating solution for forming an adhesion-modified layer, various surfactants, an antistatic agent, as long as the effects of the present invention are not impaired.
Additives such as an inorganic lubricant, an organic lubricant, and an ultraviolet absorber can be contained.

In the present invention, the adhesion-modified layer is formed by coating at least one surface of the laminated polyamide film with an organic solvent solution or dispersion of the self-crosslinkable polyester-based graft copolymer or an aqueous solvent solution or dispersion. It is usually formed by using. In particular, it is preferable to use an aqueous solution or an aqueous dispersion in that an organic solvent which poses a problem to the environment is not used. The solid content of the self-crosslinkable polyester-based graft copolymer in the coating solution is usually
It is 1 to 50% by weight, preferably 3 to 30% by weight.

As a method for applying a coating solution containing a self-crosslinkable polyester-based graft copolymer to a laminated polyamide film to form an adhesion modified layer, a gravure method, a reverse method, a die method, a bar method, a dip method, A known coating method such as a method can be used.

The coating amount of the coating solution is usually expressed as a solid content.
0.005 to 10 g / m ² , preferably 0.02 to
0.5 g / m ² . If the coating amount is less than 0.005 g / m ² , the adhesive strength between the adhesion modifying layer and the laminated polyamide film tends to decrease. In addition, when the coating amount is 10
If it exceeds g / m ² , blocking occurs and there is a practical problem.

When applied on a biaxially stretched laminated polyamide film, the polyamide film is subjected to a surface treatment such as a corona discharge treatment, a flame treatment, or an electron beam irradiation in order to further improve the adhesiveness between the laminated polyamide film and the adhesion modifying layer. You may do. Even when the coating solution is stretched after coating, the same effect can be obtained by performing the same treatment on the film surface in advance.

The drying conditions for the self-crosslinkable polyester-based graft copolymer after coating are not particularly limited. However, in order to discover the self-crosslinking property of the graft copolymer, a laminated polyamide film and the graft copolymer must be used. It is preferable that the amount of heat be increased within a range in which thermal deterioration does not occur in the coalescence. Specifically, 80-250 ° C, more preferably 150-2.
20 ° C. However, by increasing the drying time,
Even at a relatively low temperature, sufficient self-crosslinking properties are exhibited, and thus the conditions are not limited to the above.

When the above-mentioned coating solution is applied to the unstretched or uniaxially stretched laminated polyamide film and then dried and stretched, it is necessary to dry under a condition that the drying temperature after the application does not affect the subsequent stretching. In the case of a laminated polyamide film, the film is stretched with the moisture content in the film at 2% or less, and then heat-fixed at 200 ° C. or more, whereby the adhesion with the coating film is strengthened. Adhesiveness is dramatically improved. When the water content is 2% or more, depending on the drying temperature, crystallization is likely to occur, and the flatness may be deteriorated and the stretchability may be impaired.

In order to further improve the adhesiveness and printability of the surface of the adhesion modified layer of the gas barrier laminate film, the surface of the adhesion modified layer is further subjected to surface treatment such as corona discharge treatment, flame treatment and electron beam irradiation. You may.

In the present invention, the adhesion modifying layer is formed on one surface or both surfaces of the laminated polyamide film. When the adhesion modifying layer is formed on one surface of the laminated polyamide film, a gas barrier layer composed of a metal oxide thin film is formed on the surface of the adhesion modified layer, and the adhesion modified layer is formed on the laminated polyamide film. When formed on both surfaces, a gas barrier layer composed of a metal oxide thin film can be formed on one or both surfaces.

As the metal oxide thin film layer constituting the gas barrier layer, a thin film such as silicon oxide, alnium oxide, magnesium oxide or a mixture thereof is a typical thin film. Here, silicon oxide refers to SiO or SiO ₂
Aluminum oxide is composed of a mixture of various aluminum oxides such as AlO and Al ₂ O _3, and the amount of oxygen bonded in each oxide varies depending on the production conditions. .

Particularly, a mixture of aluminum oxide and silicon oxide is preferable as the gas barrier layer in the gas barrier laminate film of the present invention because of its excellent transparency and bending resistance. Further, the gas barrier layer is preferably a thin film made of a mixture of silicon oxide and aluminum oxide in which silicon oxide is 95 to 55% by weight and aluminum oxide is 5 to 45% by weight.

When the metal oxide thin film as the gas barrier layer is a silicon oxide / aluminum oxide-based evaporated film, and when the amount of aluminum oxide is less than 5% by weight, lattice defects occur in the evaporated film to obtain a sufficient gas barrier property. When the amount of aluminum oxide in the silicon oxide / aluminum oxide based deposited film exceeds 45% by weight, the flexibility of the film is reduced, and the film is destroyed due to a dimensional change during hot water treatment. A problem such as cracking or peeling is likely to occur and the gas barrier property is reduced, which is not suitable for the purpose of the present invention.

The more preferable ratio of the amount of aluminum oxide in the gas barrier layer is 10 to 35% by weight, and the more preferable ratio is 15 to 25% by weight. The gas barrier layer may further contain a small amount of other oxides and the like (generally, 3% by weight or less in all layers) as long as the characteristics are not impaired.

The thickness of the gas barrier layer formed of a metal oxide thin film in the present invention is usually from 10 to 5,000 °, preferably from 50 to 2,000 °. If the film thickness is less than 10 °, it is difficult to obtain a satisfactory gas barrier property.
If the thickness exceeds Å, the effect of improving the gas barrier property corresponding thereto cannot be obtained, which is disadvantageous in terms of bending resistance and manufacturing cost.

For the formation of the gas barrier layer composed of a metal oxide thin film, a physical vapor deposition method such as a vacuum vapor deposition method, a sputtering method, an ion plating method, or a chemical vapor deposition method such as a CVD method is appropriately used. For example, when a vacuum deposition method is adopted, a mixture of SiO ₂ and Al ₂ O ₃ or a mixture of SiO ₂ and Al is used as a deposition material.
Heating can be performed by resistance heating, induction heating, electron beam heating, etc. In addition, oxygen, nitrogen, hydrogen, argon, carbon dioxide, water vapor, etc. are introduced as a reaction gas, ozone addition, ion assist, etc. It is also possible to employ reactive vapor deposition using the above means. Further, the film forming conditions such as applying a bias to the substrate, heating and cooling the substrate, and the like can be arbitrarily changed. The above-mentioned thin film forming material, reaction gas, substrate bias, heating / cooling, and the like can be similarly changed when a sputtering method or a CVD method is adopted.

Before or during the metal oxide thin film forming operation, the surface of the laminated polyamide film as a base layer is subjected to corona discharge treatment, flame treatment, low temperature plasma treatment, glow discharge treatment, reverse sputtering treatment, surface roughening treatment. Etc.,
It is also effective to improve the adhesion strength of the metal oxide thin film. Further, there is a method of forming an anchor coat layer on the laminated polyamide film for improving adhesion, but of course, the method is not limited to these methods.

In particular, when the metal oxide thin film is a silicon oxide / aluminum oxide based thin film, the obtained evaporated film is subjected to a boiling treatment or a gelling test (bending resistance test).
Thus, it is possible to obtain a gas barrier film having excellent performance that can withstand the application of a large load.

The gas barrier property of the gas barrier laminate film of the present invention is greatly related to the adhesion strength between the laminated polyamide film serving as the base layer and the gas barrier layer, and the gas adhesion property increases as the adhesion strength increases. According to the study results of the present inventors, in order to have an excellent gas barrier property and maintain the excellent gas barrier property even after the boiling treatment, the adhesion strength of the gas barrier layer after the boiling treatment is 100 g / 15 mm. It has been confirmed that the above is preferable. More preferred adhesion strength is 150 g /
It is at least 15 mm, more preferably at least 200 g / 15 mm, even more preferably at least 250 g / 15 mm. When the adhesion strength is less than 100 g / 15 mm, the gas barrier property tends to be deteriorated by the boiling treatment.

The reason is that if the adhesion strength of the gas barrier layer is large, even if the laminated polyamide film on which the metal oxide thin film is formed by boiling treatment or retort treatment slightly shrinks, It is considered that peeling is unlikely to occur.

A thermosetting resin layer is formed as a coating layer on the metal oxide thin film layer. In this case, a two-component thermosetting resin can be used, but adhesion, heat resistance, and chemical resistance to the metal oxide thin film layer are required from the function of protecting the metal oxide thin film layer. Therefore, a thermosetting resin composed of a polyester resin and an isocyanate compound is particularly preferable as the resin used for forming the thermosetting resin layer. Such a polyester resin is a polyester resin produced by polycondensing an acid component such as dicarboxylic acid or tricarboxylic acid and a glycol component using a known method. Examples of such acid components include, but are not limited to, terephthalic acid, isophthalic acid, adipic acid, sebacic acid, trimellitic acid, and the like. Examples of the glycol include, but are not particularly limited to, ethylene glycol, neopentyl glycol, butanediol, cyclohexanediol, and ethylene glycol-modified bisphenol A. Examples of the isocyanate-based compound include compounds having a bifunctional or trifunctional aliphatic or aromatic skeleton in the skeleton. For the coating, a known coating method, for example, a roll coating method, a reverse kiss coating method, a roll flash method, a spray coating method, an air knife coating method, a gravure coating, an impregnation method, a curtain coating method, or the like can be arbitrarily adopted.

On the surface of the metal oxide thin film layer, a thermosetting resin layer and a heat sealing layer are sequentially formed. On the outermost surface of the film, a heat seal layer made of a polyolefin resin is formed mainly for the purpose of providing thermal adhesiveness. This heat seal layer also has a function as a protective layer of the metal oxide thin film layer.

The polyolefin resin constituting the heat seal layer is a polyethylene resin, a polypropylene resin,
Examples thereof include a polybutene resin, a poly-4-methylpentene-1 resin, and a random or block copolymer thereof. The polyolefin resin may contain various additives as necessary, such as a plasticizer, a heat stabilizer, an ultraviolet absorber, an antioxidant, a colorant, a filler,
It is also possible to blend antistatic agents, antibacterial agents, lubricants, antiblocking agents, other resins, and the like.

The polyolefin resin constituting the heat seal layer does not necessarily have to be a single layer, but may be a multilayer. The resin constituting each layer in the case of a multilayer structure is also the same type of resin. Not only the combination, but also a laminate of a copolymer, a modified product, a blend, or the like of different polymers may be used. For example, in order to enhance the laminating property and the heat sealing property, a polymer having a glass transition temperature (Tg) or a melting point (Tm) lower than that of the thermoplastic polyolefin-based resin as a main component is compounded, or conversely, in order to impart heat resistance. T
It is also possible to composite a polymer having a high g or Tm.

The polyolefin resin constituting the heat seal layer is laminated by a dry lamination method or a wet lamination method using an adhesive, and further by a melt extrusion lamination method or a co-extrusion lamination method. Formed as a heat seal layer on the substrate.

In order to effectively perform the function of the present invention,
It is effective to increase the adhesive force between the metal oxide thin film layer and the heat seal layer, and as a means for that, it is extremely effective to provide an adhesive layer between the metal oxide thin film layer and the heat seal layer. It is.

Particularly preferred as the resin constituting the adhesive layer is a resin having a glass transition temperature in the range of -10 to 40 ° C., such as a polyurethane resin, a polyester resin, an epoxy resin, a vinyl chloride resin, and acetic acid. Vinyl resin, polyethylene resin, polypropylene resin, melamine resin, acrylic resin, etc., these can be used alone, but if necessary, two or more kinds may be used in combination or melt-mixed, Alternatively, for example, a compound having a carboxylic acid group, an acid anhydride, a (meth) acrylic acid or a (meth) acrylate ester skeleton as a functional group: an epoxy compound containing a glycidyl group or a glycidyl ether group; an oxazoline group, an isocyanate group, or an amino group , An adhesive containing a curing agent or a curing accelerator having a reactive functional group such as a hydroxyl group It is also effective to use the Narubutsu.

A printing ink layer can be appropriately formed between the thermosetting resin layer and the heat seal layer with an arbitrary printing ink.

The thus obtained gas-barrier laminated film of the present invention makes use of its excellent gas-barrier properties, gas-barrier durability by boiling treatment and retort treatment and secondary processing characteristics, and is used as a packaging material for miso, pickles, prepared dishes, baby foods. , Tsukudani, Konjac, Chikuwa, Kamaboko, Fishery products, Meatball, Hamburger, Genghis Khan, Ham,
Sausages, other processed meat products, tea, coffee, tea, bonito, kelp, potato chips, butter peanuts and other oil confections, rice crackers, biscuits, cookies, cakes, buns, castella, cheese, butter, cut rice cake, soups, sauces , Ramen, wasabi, etc., and toothpaste, etc., as well as medical, electronic, chemical, such as pet food, pesticide, fertilizer, infusion pack, or semiconductor and precision material packaging. It can also be used effectively for packaging of industrial materials such as machines.

The form of the packaging material is not particularly limited.
It can be widely applied to bags, lid materials, cups, tubes, standing packs and the like.

[0109]

Next, the present invention will be described in detail with reference to examples. The present invention is naturally not limited by the following examples, and it is of course possible to implement the present invention with appropriate modifications within a range that can be adapted to the gist of the present invention. Included. The performance test for each characteristic value described in this specification was performed by the following method.

1) Oxygen permeability: Oxygen permeability measuring apparatus (“OX-TRAN 10 / 50A” Modern Controls)
Was measured at a humidity of 0% and a temperature of 25 ° C.

2) Water Vapor Permeability: Measured at a humidity of 0% and a temperature of 25 ° C. using a water vapor permeability measuring device (“PERMATRAN” manufactured by Modern Controls).

3) Adhesion strength: The laminated product was peeled 180 ° using “Tensilon UTM2” manufactured by Toyo Sokki Co., Ltd. while adhering water to the interface, and the SS between the gas barrier layer and the laminated polyamide film was removed. The curve was measured and determined.

4) Flex fatigue test: The flex fatigue test (hereinafter, referred to as a gelbo test) was evaluated using a gelbo flex tester manufactured by Rigaku Corporation. The condition is (M
IL-B131H) DE 112 inch × 8 inch test piece was made into a cylindrical shape having a diameter of 3 (１ ／) inch, both ends were held, the initial grasping interval was 7 inches, and 3 (1/1) of the stroke
2) With an inch, a 400 degree twist was applied. The reciprocating reciprocation of this operation is performed at a rate of 40 times / min at 1000
Performed times. Measurement atmosphere: 20 ° C, relative humidity: 65%
It is. The number of pinholes in the film after the test was counted.

(Preparation of copolymerized polyester) Dimethyl terephthalate 345 was placed in a stainless steel autoclave equipped with a stirrer, a thermometer and a partial reflux condenser.
Parts, 1,4-butanediol 211 parts, ethylene glycol 270 parts and tetra-n-butyl titanate 0.5
Then, a transesterification reaction was performed over 4 hours from 160 to 220 ° C. Next, 14 parts of fumaric acid and 160 parts of sebacic acid were added, and the temperature was raised to 200 to 220 ° C. over 1 hour to carry out an esterification reaction. Then 255
° C, and the pressure of the reaction system was gradually reduced.
The reaction was carried out for 1 hour and 30 minutes under a reduced pressure of mHg to obtain a polyester. The obtained polyester was pale yellow and transparent.

The composition and the weight average molecular weight measured by NMR were as follows. Terephthalic acid: 70 (mol%) Sebacic acid: 26 (mol%) Fumaric acid: 4 (mol%) Ethylene glycol: 50 (mol%) 1.4-butanediol: 50 (mol%) Weight average molecular weight: 20,000

(Preparation of Self-Crosslinkable Polyester Graft Copolymer) In a reactor equipped with a stirrer, a thermometer, a reflux device, and a metered dropping device, 75 parts of the copolymerized polyester resin, 56 parts of methyl ethyl ketone and 19 parts of isopropyl alcohol were added. The mixture was heated and stirred at 65 ° C. to dissolve the resin. After the resin was completely dissolved, 15 parts of maleic anhydride was added to the polyester solution. Next, a solution prepared by dissolving 10 parts of styrene and 1.5 parts of azobisdimethylvaleronitrile in 12 parts of methyl ethyl ketone was dropped into the polyester solution at 0.1 cc / min, and stirring was continued for another 2 hours. After sampling for analysis from the reaction solution, 5 parts by weight of methanol was added. Next, 300 parts by weight of water and 15 parts by weight of triethylamine were added to the reaction solution.
Stirred for hours. Thereafter, the temperature in the reactor was raised to 100 ° C., and methyl ethyl ketone, isopropyl alcohol and excess ammonia were distilled off to obtain a self-crosslinkable polyester-based graft copolymer. This self-crosslinkable polyester-based graft copolymer was pale yellow and transparent. This self-crosslinkable polyester-based graft copolymer was diluted with water: isopropyl alcohol = 9: 1 (weight ratio) to a solid content concentration of 10% by weight to prepare a coating solution.

Example 1 A layer was a mixture of 40 parts by weight of nylon 6 and 60 parts by weight of a nylon 6T / nylon 6 copolymer (copolymerization ratio of 50/50).
0 parts by weight of nylon 6 was melt-extruded while being laminated from a T-die, and cooled on a rotating drum adjusted to 20 ° C. to obtain an unstretched polyamide film having a thickness of 150 μm. This unstretched polyamide film was longitudinally stretched 3.1 times at 50 ° C. Then, it is stretched 3.3 times in the transverse direction at 125 ° C.
The film was heat-set at ℃ to obtain a biaxially stretched film having a thickness of 15 μm. At the same time, the above-mentioned water-dispersed graft polyester resin was coated to a thickness of about 0.1 μm.

This film was excellent in both bending fatigue resistance and adhesiveness. This film is sent to a vacuum deposition apparatus, the inside of the chamber is maintained at a pressure of 1 × 10 ⁵ Torr, and a mixed oxide of 70% by weight of SiO ₂ and 30% by weight of Al ₂ O _{3 is} heated by electron beam heating at 15 Kw. After evaporation, a colorless and transparent metal oxide thin film layer having a thickness of 200 ° was deposited on the coating surface to form a gas barrier layer.
On this metal oxide thin film, a two-pack type polyester / isocyanate primer (PD-4 manufactured by Dainichi Seika Kogyo Co., Ltd.
After mixing, drying and hardening, red-white overlapping printing was performed by a gravure printing method.

Then, unstretched polyethylene (thickness: 55 μm) was used as a sealant layer on the printing ink layer with an adhesive (A310 / A10 manufactured by Takeda Pharmaceutical Co., Ltd.), and a coating amount of 2 g / m2.
⁽²⁾ Dry lamination and aging at 45 ° C. for 4 days to obtain a gas barrier laminated film. (1) Oxygen permeability (cc / m ² · at) of untreated film
(2) After immersion in hot water of 95 ° C. for 30 minutes, it was left for 1 hour in air at a humidity of 0% and a temperature of 25 ° C., and the oxygen permeability measured in the atmosphere (cc / m ^2. atm.day) (3) After immersion in hot water of 95 ° C. for 30 minutes, it was left in the air of 0% humidity and 25 ° C. for 1 hour, and the water vapor permeability (g / m ^2. (4) Adhesion force (g / 15 mm) when water is dropped on the peeling interface of the film after being immersed in hot water of 95 ° C. for 30 minutes and left in air at a temperature of 25 ° C. for 1 hour. The number of pinholes (pieces) after the bending fatigue test was measured. Table 1 shows the evaluation results of the obtained gas barrier laminate films.

(Example 2) In the method of Example 1, A
The procedure was exactly the same as in Example 1, except that the layer was a mixture of 25 parts by weight of nylon 6 and 75 parts by weight of a nylon 6T / nylon 6 copolymer (copolymerization ratio 50/50).
Table 1 shows the evaluation results of the obtained gas barrier laminate films.

(Embodiment 3) In the method of Embodiment 1, A
Except that the layer was 100 parts by weight of nylon 6T / nylon 6 copolymer (copolymerization ratio 50/50), the same procedure as in Example 1 was carried out. Table 1 shows the evaluation results of the obtained gas barrier laminate films.

(Comparative Example 1) In the method of Example 1, A
The layer was 100 parts by weight of nylon 6, the thermosetting resin coating layer was not provided, and a polyester coating agent (AGN1 manufactured by Toyobo Co., Ltd.) was used as a coating agent.
Except that 31) was used, the procedure was exactly the same as in Example 1.
Table 1 shows the evaluation results of the obtained gas barrier laminate films.

(Hiki Example 2) In the method of Example 1, A
The procedure was exactly the same as in Comparative Example 1, except that 75 parts by weight of nylon 6 and 25 parts by weight of a nylon 6T / nylon 6 copolymer (copolymerization ratio 50/50) were used as a layer. Table 1 shows the evaluation results of the obtained gas barrier laminate films.

[0124]

[Table 1]

[0125]

According to the gas barrier laminate film of the present invention, water does not enter at the interface between the metal oxide thin film layer and the laminated polyamide film layer even after the food or the like is boiled as a package. Therefore, it is considered that peeling and floating of the metal oxide thin film layer from the surface of the laminated polyamide film or deterioration due to chemical change of the metal oxide thin film layer are suppressed.

This is considered to be because the hardness of the surface of the polyamide film of the layer A is large and the metal oxide thin film layer is dense and has few defects. However, it is considered that good gas barrier properties are maintained.

Further, by providing the thermosetting resin layer, it is possible to prevent chlorine or the like volatilized from entering the metal oxide thin film layer from deteriorating, and to prevent inorganic particles in the printing ink from being printed when printing. Can prevent the metal oxide thin film layer from being damaged, thereby preventing the gas barrier laminate film from deteriorating the scab barrier property.

[Brief description of the drawings]

FIG. 1A is a diagram showing an example of a cross section of the gas barrier laminate film of the present invention. (B) is a figure which shows the other example of the cross section of the gas-barrier laminated film of this invention.
(C) is a figure which shows the other example of the cross section of the gas-barrier laminated film of this invention. (D) is a figure which shows another example of the cross section of the gas-barrier laminated polyamide film of this invention.

[Explanation of symbols]

 Reference Signs List 1 laminated polyamide film 2 adhesion modified layer 3 gas barrier layer 4 thermosetting resin layer 5 printing ink layer 6 polyolefin layer

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Shinji Fujita 2-1-1 Katata, Otsu City, Shiga Prefecture Inside Toyobo Co., Ltd. (72) Inventor Chikao Morishige 2-1-1 Katata, Otsu City, Shiga Prefecture No. 1 Toyobo Co., Ltd. Research Institute (72) Inventor Seiichiro Yokoyama 2-1-1 Katata, Otsu-shi, Shiga Prefecture Toyobo Co., Ltd. Research Center (72) Inventor Kiyoji Iseki 2-1-1 Katata, Otsu-shi, Shiga Prefecture No. 1 Toyobo Co., Ltd. Research Laboratory F-term (reference) 4F100 AA17D AA19D AA20D AK01E AK02C AK04 AK12C AK24C AK41C AK47A AK48A AK48B AK51 AL01A AL04C BA05 BA07 BA10B BA10E BA13 CA30C EB00 EB36 GBC EB00 JB06C JB13E JD02 JD02D JD04 JK06 JL05 JL11C JL12E JM02D JN01 YY00A YY00D

Claims (9)

[Claims] 1. A / B or A / B comprising the following composition:
A polymerizable unsaturated monomer containing a polymerizable unsaturated monomer having hydrophilicity is grafted onto a hydrophobic polyester resin on one or both A layers of a laminated polyamide film having a B / A layer structure. An adhesive reforming layer comprising a self-crosslinkable polyester-based graft copolymer obtained by polymerization as a component, a gas barrier layer comprising a metal oxide thin film layer, a thermosetting resin layer and a heat sealing layer are sequentially laminated. A gas barrier laminated film characterized by the above-mentioned. -Polyamide resin composition forming A layer (X) component: 10 mol% or more of aromatic polyamide resin component (a) composed of terephthalic acid and / or isophthalic acid and aliphatic diamine and aliphatic polyamide resin component ( b) Composition comprising a mixed polymer and / or copolymer with 90 mol% or less-Polyamide-based resin composition forming B layer Composition composed of aliphatic polyamide-based resin 2. The polyamide resin composition forming the layer A is composed of a component (X): an aromatic polyamide resin component (a) composed of terephthalic acid and / or isophthalic acid and an aliphatic diamine (a) at least 10 mol% and a fat. It is a composition containing the component (Y): 100 parts by weight or less of the aliphatic polyamide-based resin with respect to 100 parts by weight of the mixed polymer and / or copolymer with the aliphatic polyamide-based resin component (b) of 90 mol% or less. The gas barrier laminate film according to claim 1, wherein: 3. The polyamide-based resin composition forming the layer A comprises (X) an aromatic polyamide-based resin component (a) comprising at least 10 mol% of terephthalic acid and / or isophthalic acid and an aliphatic diamine. Composition containing (Z) component: 20 parts by weight or less of flex fatigue resistance improving agent per 100 parts by weight of a mixed polymer and / or copolymer with 90 mol% or less of aliphatic polyamide resin component (b) The gas barrier laminate film according to claim 1, wherein: 4. An adhesion-modified layer, in which a coating solution containing a self-crosslinkable polyester-based graft copolymer is applied to an unstretched or uniaxially stretched film and dried, and the film is further stretched uniaxially or more. 4. The gas barrier laminate film according to claim 1, wherein the film is formed by heat setting. 5. The polymerizable unsaturated monomer having a hydrophilic property,
5. The gas barrier laminate film according to claim 1, which is an acid anhydride having a double bond. 6. The gas barrier laminate film according to claim 5, wherein the acid anhydride having a double bond contains maleic anhydride. 7. The gas barrier laminate film according to claim 1, wherein the polymerizable unsaturated monomer contains styrene. 8. The gas barrier layer comprising a metal oxide thin film layer is a thin film comprising a mixture of silicon oxide and aluminum oxide.
8. The gas barrier laminate film according to 6 or 7. 9. The gas barrier laminate film according to claim 8, wherein the gas barrier layer comprising the metal oxide thin film layer contains 95 to 55% by weight of silicon oxide and 5 to 45% by weight of aluminum oxide.