JP2000202938A - Gas barrier laminate film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain excellent transparency, gas barrier properties, adhesive properties or the like by forming a layer containing a polyester graft polymer grafted with one or more types of polymerizable unsaturated monomers with a hydrophobic polyester and a metal oxide thin film layer on at least one surface of a polyamide film. SOLUTION: A layer containing a polyester graft polymer grafted with one or more types of polymerizable unsaturated monomers with a hydrophobic polyester and a metal oxide thin film layer are sequentially formed on at least one surface of a polyamide film. As the polyamide film, an aromatic polyamide containing a terephthalic acid or isophthalic acid and an amide unit having an aliphatic diamine of 10 mol% or above is preferably used. A weight ratio of the polyester and the monomer is desirably 40/60 to 95/5. As the thin film layer, silicon oxide, aluminum oxide, magnesium oxide, their mixtures or the like are used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gas barrier property and a moisture-proof property which are important properties in packaging films for fresh foods, processed foods, pharmaceuticals, medical equipment, electronic parts, etc., and also to transparency and handleability. The present invention relates to a laminated film or sheet excellent in the above.

[0002]

2. Description of the Related Art In recent years, food packaging forms have changed drastically due to changes in food distribution and dietary habits, and the required characteristics of packaging films and sheets (hereinafter represented by films) have become increasingly severe. Is coming. Deterioration of product quality due to the effects of temperature, moisture, oxygen, ultraviolet rays, and microorganisms such as bacteria and mold in the distribution and sales process 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 directly added to foods in the past.
In recent years, regulations on food additives have become stricter from the standpoint of consumer protection, and it has been required to reduce the amount of food additives or to eliminate them. There is an increasing demand for a packaging film that does not cause deterioration in the quality of food as a result of processing, boiling treatment, retort treatment, and the like.

[0003] That is, in the packaging of fish meat, animal meat, shellfish and the like, it is important to suppress the oxidation and deterioration 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.

[0004] For these reasons, kamaboko paste products, butter, dairy products such as 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 food packaging films, but are also extremely important as medical products that need to be handled under aseptic conditions or packaging films for electronic components that require rust prevention.

[0005] Films having excellent gas barrier properties include:
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 an inorganic thin film, a device in which a deposited film of silicon oxide, aluminum oxide, or the like is laminated is also known.

In actual use, a polyamide layer 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, a bag is created using the laminate, the contents are filled, and the opening is heat-sealed.For example, a seasoning such as miso or soy sauce, a water-containing food such as a soup or a retort food, or a medicine is packaged. To the general consumer.

The following problems have been pointed out in the conventional gas barrier films as described above. 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 .

On the other hand, those coated with vinylidene chloride or ethylene vinyl alcohol copolymer do not have sufficient gas barrier properties against water vapor, oxygen and the like, and the performance is remarkably deteriorated due to high temperature treatment. In addition, there is a concern that vinylidene chloride may cause air pollution due to generation of chlorine gas at the time of incineration.

Therefore, a resin film having an inorganic vapor-deposited layer such as silicon oxide or aluminum oxide formed as a gas barrier layer has been proposed. As a substrate film on which silicon oxide, aluminum oxide, and the like are deposited, a polyester film (PET) having good dimensional stability has been used conventionally.

The composition is PET / deposited layer / adhesive layer / P
Usually, a laminated structure such as ET / adhesive layer / unstretched polypropylene (CPP) is used. However, a film having such a laminated structure has a problem of insufficient strength against drop impact.

On the other hand, PET / evaporated layer / adhesive layer / stretched nylon (ONY) / adhesive layer / unstretched polypropylene (CP
In the case of the laminated structure as in P), there arises a problem that the gas barrier property after boil treatment or retort treatment is deteriorated due to shrinkage of nylon.

Therefore, a film laminated with nylon having a reduced shrinkage during high-temperature hot water treatment (Japanese Patent Laid-Open No. 7-2765).
No. 71) 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.

[0013] A gas barrier film using a nylon film as a vapor deposition substrate has been studied, but the nylon film has a large dimensional change due to moisture absorption or heating, so that the barrier property is unstable. In particular, the gas barrier film after boil treatment or retort treatment is used. The problem that the performance deteriorates arises.

Therefore, as a measure for improving the gas barrier properties, a laminated film (JP-B-7-1264) using stretched nylon having a reduced shrinkage rate in advance by a heat treatment as a deposition base material.
No. 9) has been proposed. However, the manufacturing process and the transportation and storage processes become complicated, which is not practical. In addition, nylon with a small shrinkage rate during high-temperature treatment (Japanese
In No. 12649, the sum of the absolute values of the dimensional change rates in the vertical and horizontal directions when heated at 120 ° C. for 5 minutes is 2% or less.
However, excellent gas barrier properties cannot be maintained by boiling treatment, which is a high-temperature hot water treatment.

Further, when a nylon film is used as a vapor deposition base material, if water infiltrates between the nylon film and the vapor deposition layer, the adhesive strength between the layers is significantly reduced, and when it is used as a packaging bag, it only causes breakage. It is thought that it 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 an inorganic vapor-deposited layer such as silicon oxide or aluminum oxide does not always have sufficient strength, and that gas barrier properties are deteriorated due to boiling treatment or retort treatment.

[0017] In addition, Japanese Patent Publication No. 51-48511 discloses a gas barrier film which is transparent, allows the contents to be seen through, and which can be applied to a microwave oven. ₂ ) A gas barrier film on which is deposited is proposed. However, an SiOx-based (x = 1.3 to 1.8) vapor-deposited film having a good gas barrier property has a slightly brown color, and cannot be said to have a sufficient quality as a transparent gas barrier film.

Japanese Patent Application Laid-Open No. 62-101428 describes a device provided with an inorganic vapor-deposited layer mainly composed of aluminum oxide, which not only has an insufficient gas barrier property but also has a bending resistance. There are also problems.

Further, resistance to boiling resistance and, also, but what is proposed in JP-A-2-194944 as an example of Al ₂ O ₃ · SiO ₂ system as a gas barrier layer having a retort resistance, and Al ₂ O ₃ The gas barrier layer is formed by stacking SiO ₂ , and requires a large-scale apparatus in which the formation of the gas barrier layer is complicated. In addition, films using these inorganic 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 boil resistance and retort resistance, a film thickness of a certain degree or more (for example, about 2000 mm or more) is required. A gas barrier film that has sufficient gas barrier properties and moisture resistance, has good boil resistance and retort resistance, and has excellent bending resistance and can withstand drop impacts. Currently not proposed.

[0020]

DISCLOSURE OF THE INVENTION The present invention has been made in view of such circumstances, and has an object to provide excellent transparency, gas barrier properties and adhesiveness, even after a boil treatment or a printing process. Economically provides a gas barrier laminated film or sheet that does not impair its excellent barrier properties, has good bending resistance, has sufficient strength to withstand drop impact, and also has excellent heat sealing properties. Is to do.

[0021]

That is, the present invention is as follows. (1) A layer containing a polyester-based graft polymer in which one or more polymerizable unsaturated monomers are grafted on a hydrophobic polyester and a metal oxide thin film layer are sequentially formed on at least one surface of a polyamide film. A gas-barrier laminated film characterized by the following. (2) The polyamide film contains 50 or more aromatic polyamides containing amide units composed of terephthalic acid or isophthalic acid and an aliphatic diamine as constituents in an amount of 50 mol% or more.
The gas-barrier laminated film according to (1), which has at least one layer containing at least one weight%. (3) The adhesive strength between the base polyamide film and the metal oxide thin film layer after boiled in hot water at 95 ° C. for 30 minutes is 100 g / 15 mm or more (1).
The gas barrier laminate film according to the above. (4) The polymerizable unsaturated monomer contains at least one acid anhydride having a double bond (1), (2).
Or the gas barrier laminate film according to (3). (5) The gas barrier laminate film according to (4), wherein the polymerizable unsaturated monomer contains at least an anhydride of maleic acid and styrene. (6) A layer containing a polyester-based graft polymer is coated with a coating solution containing the graft polymer on an unstretched or uniaxially stretched film, dried, and then further stretched uniaxially or more, and then heat-fixed. The gas barrier laminate film according to (1), which is formed by the above method. (7) The gas barrier laminate film according to (1) or (2), wherein the metal oxide thin film layer is a thin film layer made of a mixture of silicon oxide and aluminum oxide. (8) In the metal oxide thin film layer, the content of aluminum oxide in the mixture of silicon oxide and aluminum oxide is 5
The gas barrier laminate film according to (1) or (2), which is not less than 45% by weight and not more than 45% by weight.

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

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION In the following, each layer constituting material specified in the present invention will be described in detail, and the reason for defining the above characteristics will be described in detail.

Polyamide Film In the polyamide film of the present invention, an aromatic polyamide containing an amide unit composed of terephthalic acid or isophthalic acid and an aliphatic diamine as a constituent component can be preferably used.

It is necessary that the amide unit is contained in an amount of 10 mol% or more, but it may be a copolymer with another polyamide unit. It may be mixed in an amount of not more than% by weight.

In the present invention, a film in which an aliphatic polyamide film is laminated on one surface of the above-mentioned film containing aromatic polyamide, or a film in which the above-mentioned film containing aromatic polyamide is laminated on both surfaces of the aliphatic polyamide film Preferably, a film is used. In this case, the layer containing the polyester-based graft polymer and the metal oxide thin film layer are formed on the aromatic polyamide film side.

Examples of the aliphatic diamine include tetramethylene diamine and hexamethylene diamine, and hexamethylene diamine is preferred.

The aliphatic polyamide used in the present invention includes nylon 4, nylon 6, nylon 7, nylon 11, nylon 12, nylon 66, nylon 612,
Nylon 46 and their copolymers, blends and the like can be mentioned, but nylon 6 and nylon 66 are preferred.

In the aromatic polyamide film of the present invention, a bending fatigue resistance improving agent such as block polyesteramide can be added and used.

When a laminated polyamide film is used in the present invention, the laminated polyamide film can be produced by a known production method. That is, the polymer constituting each layer is melted using a separate extruder, and a method of manufacturing by co-extrusion, a method of laminating the polymer constituting each layer by lamination, a method of combining these, and the like can be used. it can. Further, the laminated polyamide film can be used as either an unstretched film or a stretched film, but the gas barrier laminate film obtained according to the present invention is stretched uniaxially or biaxially to improve the processability of the film. Is desirable. 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. Further, the purpose of the gas barrier laminate film of 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.

Although the thickness of the polyamide film is not particularly limited, it is 0 to 30 μm, preferably 10 to 30 μm, and more preferably 15 to 25 μm. If the thickness is out of this range, problems arise in film strength and cost.

Layer Containing Polyester Graft Polymer The polyester graft polymer layer coated on the polyamide film is used for the purpose of improving the adhesion of the polyamide film. The graft polymer is generally obtained by reacting a polymerization initiator and a mixture of a polymerizable unsaturated monomer in a state where a hydrophobic polyester is dissolved in an organic solvent. The reaction product after the completion of the grafting reaction is usually converted into a non-grafted hydrophobic polyester and a hydrophobic polyester, in addition to the desired hydrophobic polyester-graft polymer between the polymerizable unsaturated monomer mixture. It also contains non-grafted polymer unsaturated monomers. In the present invention, the term "graft polymer" is generically referred to including these mixtures.

In the present invention, the acid value of the reaction product obtained by graft-polymerizing a polymerizable unsaturated monomer onto a hydrophobic polyester is preferably at least 600 eq / 10 ⁶ g. More preferably, the acid value of the reactants is 1200 eq / 10 ⁶ g or more. If the acid value of the reaction product is less than 600 eq / 10 ⁶ g, the adhesiveness with the polyamide film layer, which is the object of the present invention, cannot be said to be sufficient.

Also, the weight ratio of the desired hydrophobic polyester and the polymerizable unsaturated monomer which is suitable for the purpose of the present invention is as follows:
Polyester / polymerizable unsaturated monomer = 40 / 60-95
/ 5 is desirable, more preferably 55 / 45-9.
3/7, most preferably in the range of 60/40 to 90/10. When the weight ratio of the hydrophobic polyester is less than 40% by weight, excellent adhesiveness of the polyester cannot be exhibited. On the other hand, when the weight ratio of the hydrophobic polyester is more than 95% by weight, blocking which is a drawback of the polyester tends to occur.

The graft polymer of the present invention can be used in the form of a solution or dispersion of an organic solvent or a solution or dispersion of an aqueous solvent. However, it is preferable in terms of working environment and applicability. In order to obtain such a water-dispersed resin, usually, in an organic solvent, the hydrophobic polyester is graft-polymerized with a polymerizable unsaturated monomer containing a hydrophilic monomer, and then water is added. This is achieved by dispersing the graft polymer and distilling off the organic solvent.

The water-dispersed resin of the present invention has an average particle size of 500 nm or less as measured by a laser light scattering method and has a translucent or milky white appearance. By adjusting the polymerization method, 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 3 nm or less.
00 nm or less. If it exceeds 500 nm, the gloss of the coating film surface is reduced, and the transparency of the coating material is reduced.
If it is less than nm, the water resistance, which is the object of the present invention, is reduced, so that it is not preferable.

Hydrophobic Polyester In the present invention, the hydrophobic polyester is required to be essentially water-insoluble without originally dispersing or dissolving in water by itself. When a polyester that disperses or dissolves in water is used for graft polymerization, the adhesiveness and water resistance, which are the objects of the present invention, deteriorate.

In the present invention, the hydrophobic polyester preferably has an aromatic dicarboxylic acid residue, and more preferably has a small amount of double bonds for efficient grafting.

Composition of 60 to 99.5 mol% of aromatic dicarboxylic acid, 0 to 40 mol% of aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid, and 0.5 to 10 mol% of dicarboxylic acid containing a double bond. It is preferable to use the dicarboxylic acid component of If the amount of the aromatic dicarboxylic acid is less than 60 mol% or if the amount of the aliphatic dicarboxylic acid and / or the alicyclic dicarboxylic acid exceeds 40 mol%, the adhesive strength decreases.

When the amount of the dicarboxylic acid having a double bond is less than 0.5 mol%, it is difficult to efficiently graft the polymerizable unsaturated monomer to the polyester. If it exceeds, the viscosity increases too much in the latter stage of the grafting reaction, which hinders the uniform progress of the reaction, which is not preferred. More preferably, the aromatic dicarboxylic acid is 70 to 98 mol%, the aliphatic dicarboxylic acid and / or the alicyclic dicarboxylic acid is 0 to 30 mol%, and the dicarboxylic acid containing a double bond is 2 to 7 mol%.

Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid and the like. It is preferable not to use a hydrophilic group-containing dicarboxylic acid such as 5-sodium sulfoisophthalic acid from the viewpoint of reducing the water resistance, which is the object of the present invention.

As the aliphatic dicarboxylic acid, succinic acid,
Adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, dimer acid and the like can be mentioned. Examples of the alicyclic dicarboxylic acid include 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,2-cyclohexanedicarboxylic acid.
Examples thereof include cyclohexanedicarboxylic acid and acid anhydrides thereof.

Examples of the dicarboxylic acid containing a double bond include fumaric acid and α, β-unsaturated dicarboxylic acid.
Maleic acid, maleic anhydride, itaconic acid, citraconic acid, as an alicyclic dicarboxylic acid containing a double bond,
2,5-norbornene dicarboxylic anhydride, tetrahydrophthalic anhydride and the like can be mentioned. Of these, fumaric acid, maleic acid,
2,5-norbornene dicarboxylic acid.

On the other hand, as the glycol component of the hydrophobic polyester, an aliphatic glycol having 2 to 10 carbon atoms and / or an alicyclic glycol having 6 to 12 carbon atoms and / or a glycol containing an ether bond can be used. Carbon number 2
Examples of the aliphatic glycols having a molecular weight of 10 to 10 include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, and 1,6-hexanediol. , 3-methyl-1,5-pentanediol,
Examples of 1,9-nonanediol, 2-ethyl-2-butylpropanediol, and the like, and examples of the alicyclic glycol having 6 to 12 carbon atoms 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, such as 2,2-glycol. Bis (4-hydroxyethoxyphenyl) propane and the like can be mentioned. Polyethylene glycol, polypropylene glycol and polytetramethylene glycol can also be used if necessary.

In the hydrophobic polyester used in the present invention, up to 5 mol% of a polycarboxylic acid and / or polyol having three or more functional groups can be copolymerized. Examples of the trifunctional or higher polycarboxylic acid include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, benzophenonetetracarboxylic acid, benzophenonetetracarboxylic anhydride, trimesic acid, ethylene glycol bis (anhydrotrimellitic acid). Tetrate), glycerol tris (anhydrotrimellitate) and the like are used. on the other hand,
Glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like are used as the trifunctional or more functional polyol. The amount of the trifunctional or higher polycarboxylic acid and / or polyol is up to 5 mol%, preferably up to 3 mol%, based on the total acid component or total glycol component. If it exceeds 5 mol%, gelation during polymerization may occur. It is easy to happen and is not preferred.

The molecular weight of the hydrophobic polyester is preferably in the range of 5,000 to 50,000 on a 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.

Polymerizable unsaturated monomer The following are examples of the polymerizable unsaturated monomer of the present invention. Fumaric acid, monoethyl fumarate, diethyl fumarate, monoesters and diesters of fumaric acid such as dibutyl fumarate, maleic acid and its anhydrides, monoethyl maleate, diethyl maleate, monoesters of maleic acid such as dibutyl maleate and Diester,
Itaconic acid and its anhydrides, monoesters and diesters of itaconic acid, maleimides such as phenylmaleimide,
Styrene, α-methylstyrene, t-butylstyrene,
Styrene derivatives such as chloromethylstyrene; vinyltoluene; divinylbenzene; As the acrylic polymerizable monomer, for example, alkyl acrylate,
Alkyl methacrylate (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-
Butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group, phenyl group, benzyl group, phenylethyl group, etc.); hydroxy-containing acrylic monomers such as 2-hydroxyethyl acrylate,
-Hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate; amide group-containing acrylic monomers such as acrylamide, methacrylamide, N-methylmethacrylamide, N-methylacrylamide, N-methylolacrylamide, N- Methylol methacrylamide, N, N
-Dimethylolacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide,
N-phenylacrylamide; an amino group-containing acrylic monomer such as N, N-dimethylaminoethyl acrylate, N, N-diethylaminoethyl methacrylate;
Epoxy group-containing acrylic monomers, for example, glycidyl acrylate, glycidyl methacrylate; acrylic monomers containing a carboxyl group or a salt thereof, for example, acrylic acid, methacrylic acid and salts thereof (sodium salt, potassium salt, ammonium salt) And the like. Preferred are maleic anhydride and its esters. One or more of the above monomers are graft-polymerized to the hydrophobic polyester by using one or more of them. For the purpose of the present invention, it is preferable that the monomer contains at least one acid anhydride having a double bond. In particular, it is desirable to use maleic anhydride and styrene in combination as a polymerizable unsaturated monomer.

The polyester-based graft polymer of the present invention is preferably in the form of a water-dispersed resin. For this purpose, a polymerizable unsaturated monomer containing a hydrophilic monomer is used.

The hydrophilic monomer used for preparing the water-dispersed resin refers to a monomer having a hydrophilic group or a group which can be converted into a hydrophilic group later. Examples of the monomer having a hydrophilic group include monomers having 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. On the other hand, examples of the monomer having a group that can be converted into a hydrophilic group include monomers having an acid anhydride group, a glycidyl group, a chloro group, and the like. Among these, a carboxyl group is preferable from the viewpoint of water dispersibility, and a monomer having a carboxyl group or a group having a group generating a carboxyl group is preferable. From the viewpoint of achieving a desired acid value, it is more preferable that the compound contains a carboxyl group or contains a monomer that generates a carboxyl group.

Graft Polymerization The graft polymerization of the present invention is generally carried out by reacting a polymerization initiator and a polymerizable unsaturated monomer mixture in a state where a hydrophobic polyester is dissolved in an organic solvent. The reaction product at the end of the grafting reaction is, in addition to the desired hydrophobic polyester-graft polymer between the polymerizable unsaturated monomer mixture, as well as the non-grafted hydrophobic polyester and hydrophobic polyester. It also contains polymerizable unsaturated monomers that have not been grafted. In the present invention, the term "graft polymer" is generically referred to including these mixtures.

Polymerization Initiator and Other Additives As the graft polymerization initiator that can be used in the present invention, organic peroxides and organic azo compounds known to those skilled in the art can be used. Benzoyl peroxide, as an organic peroxide,
t-butyl peroxypivalate, as an organic azo compound, 2,2′-azobisisobutyronitrile, 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 or more, preferably 0.5% by weight or more based on the polymerizable unsaturated monomer, and the upper limit is not particularly limited, but is not particularly limited. , 6% by weight.

In addition to the graft polymerization initiator, a chain transfer agent for controlling the chain length of the branch polymer, for example, octyl mercaptan, mercaptoethanol, 3-t-butyl-4
-Hydroxyanisole and the like can be used as needed.
In this case, it is desirable to add up to 5% by weight based on the polymerizable unsaturated monomer.

Reaction Solvent The grafting reaction solvent for carrying out the present invention has a boiling point of 50.
It is preferred to be composed of an aqueous organic solvent at ~ 250 ° C. Here, the aqueous organic solvent has a solubility in water at 20 ° C. of at least 10 g / L, preferably 20 g / L.
/ L or more. Those having a boiling point exceeding 250 ° C. are unsuitable because the evaporation rate is too slow to remove sufficiently even by baking the coating film at a high temperature.
If the boiling point is lower than 50 ° C., when a grafting reaction is carried out using the solvent as a solvent, a polymerization initiator that cleaves into radicals at a temperature lower than 50 ° C. must be used, which increases the danger in handling.

The first group of aqueous organic solvents in which the hydrophobic polyester is well dissolved and the polymerizable unsaturated monomer mixture and its polymer are relatively well dissolved include esters such as ethyl acetate, ketones such as methyl ethyl ketone, methyl Isobutyl ketone, cyclohexanone, cyclic ethers such as 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, glycols or lower esters of glycol ethers such as ethylene glycol Diacetate, ethylene glycol ethyl ether acetate, ketones alcohols e.g. diacetone alcohol, more N- substituted amides such as dimethylformamide, dimethylacetamide,
N-methylpyrrolidone and the like can be exemplified.

On the other hand, as a second group of aqueous organic solvents which hardly dissolve the hydrophobic polyester but relatively well dissolve the polymerizable unsaturated monomer mixture and its polymer, water, lower alcohols (for example, , Methanol, ethanol, n-propyl alcohol, isopropyl alcohol, etc.), lower glycols (eg, ethylene glycol, triethylene glycol, dipropylene glycol, etc.), lower carboxylic acids (eg, formic acid, acetic acid, propanoic acid, butanoic acid, etc.) ), Lower amines, etc., and particularly preferred for the practice of the present invention are alcohols and glycols having 1 to 4 carbon atoms.

When the grafting reaction is performed in a single solvent,
It can be carried out by selecting just one kind from the first group of aqueous organic solvents. When using a mixed solvent, there are a case where a plurality of types are selected only 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 grafting reaction solvent is a single solvent from the first group of aqueous organic solvents, and when it is a mixed solvent comprising one kind of each of the first and second groups of aqueous organic solvents. A graft polymerization reaction can be performed. However, there are differences in the progression behavior of the grafting reaction, the appearance and properties of the grafting reaction product and the water-dispersed resin derived therefrom, and a mixed solvent composed of one of the first and second groups of aqueous organic solvents, respectively. It is preferable to use

In the solvent of the first group, the molecular chain of the hydrophobic polyester is in a state of extending the chain having a large spread, while in the mixed solvent of the first and second groups, the molecular chain of the hydrophobic polyester is entangled in a small spread. Was confirmed by measuring the viscosity of the hydrophobic polyester in these solutions. It is effective to prevent gelation by adjusting the dissolution state of the polyester so that intermolecular crosslinking is less likely to occur. Both high efficiency of grafting and suppression of gelation are achieved in the latter mixed solvent system. The weight ratio of the first group / second group of the mixed solvent is preferably 95/5 to 10/90, more preferably 90/10 to 2
0/80, more preferably in the range of 85/15 to 30/70. The optimum mixing ratio is determined according to the solubility of the polyester used.

Aqueous Dispersion The graft polymer obtained by copolymerizing a hydrophilic monomer having an acidic group 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 hardening by blending a crosslinking 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, iminobispropylamine, ethylamine, diethylamine , 3-ethoxypropylamine, 3-diethylaminopropylamine, se
Examples thereof include c-butylamine, propylamine, methylaminopropylamine, dimethylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine, and triethanolamine. The basic compound has a pH value of the water-dispersed resin 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. Boiling point is 100
When a basic compound having a temperature of not more than 0 ° C. is used, the residual basic compound in the coating film after drying is small, and the adhesion to a metal or metal oxide thin film layer or the water resistance or hot water adhesion of the laminate. Excellent in properties.

In the water-dispersed resin produced according to the present invention,
The weight average molecular weight of the polymer of the polymerizable unsaturated monomer is 500
It is preferably ~ 50,000. It is generally difficult to control the weight average molecular weight of the polymer of the polymerizable unsaturated monomer to 500 or less, and the grafting efficiency is reduced,
There is a tendency that the hydrophilic group is not sufficiently imparted to the polyester. Further, the graft polymer of the polymerizable unsaturated monomer forms a hydrated layer of the dispersed particles, but in order to provide a hydrated layer having a sufficient thickness and obtain a stable dispersion, a polymerizable unsaturated monomer is used. The weight average molecular weight of the graft polymer is preferably 500 or more. 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. Control of the molecular weight within this range can be performed by appropriately combining a polymerization initiator amount, a monomer dropping time, a polymerization time, a reaction solvent, a monomer composition or a chain transfer agent or a polymerization inhibitor as needed. I can do it.

In the present invention, a reaction product obtained by graft-polymerizing a polymerizable unsaturated monomer onto a hydrophobic polyester is as follows:
It has self-crosslinking properties. Although it does not crosslink at room temperature, it crosslinks without a crosslinking agent by performing 1) a dehydration reaction of a carboxyl group present in the graft polymer and 2) a hydrogen abstraction reaction due to a heat radical by the heat of drying. Thereby, the adhesiveness and water resistance, which are the objects of the present invention, can be expressed for the first time.

Although the self-crosslinking property of the coating film can be evaluated by various methods, it can be examined by the insoluble content in a chloroform solvent which dissolves both the hydrophobic polyester and the polymerizable unsaturated monomer.

The coating film obtained by drying at 80 ° C. or lower and heat-treating at 120 ° C. for 5 minutes preferably has an insoluble content of 50%
It is more preferably 70% or more. When the insoluble content of the coating film is less than 50%, not only the adhesion and water resistance are not sufficient, but also blocking occurs.

The above graft polymer can be used as it is in the present invention. However, by adding a cross-linking agent (curing resin) and curing it, a high degree of water resistance is imparted to the polyester-based graft polymer layer. obtain.

Examples of the crosslinking agent include a phenol formaldehyde resin of a condensate of alkylated phenols, cresols, etc. with formaldehyde; an adduct of urea, melamine, benzoguanamine, etc. with formaldehyde; Amino resins such as alkyl ether compounds comprising alcohols of No. 6, polyfunctional epoxy compounds, polyfunctional isocyanate compounds, blocked isocyanate compounds, polyfunctional aziridine compounds;
Oxazoline compounds and the like 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-cresol, m-cresol, p-cresol, p-cyclohexylphenol, 4,4'-isopropylidenediphenol (hereinafter, referred to as Bisphenol A), p-nonylphenol, p-octylphenol, 3-pentadecylphenol, phenol, α-phenyl-o-cresol, p-phenylphenol, xylenol and other phenols, and condensates of cresols and formaldehyde. Can be mentioned.

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 the like. But
Preferably, methoxylated methylol melamine, butoxylated methylol melamine, methylolated benzoguanamine and the like can be mentioned.

Examples of the polyfunctional epoxy compound include diglycidyl ethers of bisphenol A and oligomers thereof, diglycidyl ethers of hydrogenated bisphenol A and oligomers thereof, diglycidyl orthophthalate, diglycidyl isophthalate, and diglycidyl terephthalate. Glycidyl ester, p-oxybenzoic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, succinic acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, ethylene glycol di Glycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol glycidyl ether And polyalkylene glycol diglycidyl ethers, trimellitic acid triglycidyl ester, triglycidyl isocyanurate, 1,4
-Diglycidyloxybenzene, diglycidyl propylene urea, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol triglycidyl ether, triglycidyl ether of glycerol alkylene oxide adduct and the like.

As the polyfunctional isocyanate compound,
Low-molecular or high-molecular aromatic or aliphatic diisocyanates and trivalent or higher polyisocyanates can be used. As low molecular or high molecular aromatic diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, low molecular or high molecular aliphatic diisocyanate, hexamethylene diisocyanate,
Isophorone diisocyanate. As the polyisocyanate, tetramethylene diisocyanate,
Hexamethylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylidene diisocyanate, isophorone diisocyanate, 3 of this isocyanate compound
Is a monomer. Further, an excess amount of these isocyanate compounds and a low-molecular active hydrogen compound such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, or polyester polyols, Examples thereof include a terminal isocyanate group-containing compound obtained by reacting a polymer active hydrogen compound such as ether polyols and polyamides.

The blocked isocyanate compound can be prepared by subjecting the 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 ethyl ketoxime and cyclohexanone oxime; alcohols such as methanol, ethanol, propanol and butanol;
Halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol; tertiary alcohols such as t-butanol and 3-pentanol;
Lactams such as caprolactam, δ-valerolactam, γ-butyrolactam, β-propyl lactam; aromatic amines; imides; active methylene compounds such as acetylacetone, acetoacetate, and malonic acid ethyl ester; mercaptans; Ureas; diaryl compounds; sodium bisulfite and the like.

Examples of the oxazoline compound include 2-methyl-2-oxazoline.

These crosslinking agents may be used alone or in combination.
A mixture of more than one species can be used. The compounding amount of the crosslinking agent is preferably 5 parts by weight to 40 parts by weight based on 100 parts by weight of the graft polymer. 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 polymer, or (2) an oil-soluble crosslinking agent. In such a case, there is a method of adding to the reaction solution after the completion of the grafting reaction. These methods can be appropriately selected depending on the type and properties of the crosslinking agent. Further, a conventionally known curing agent or accelerator can be used in combination with the crosslinking agent.

The above graft polymer can be used as it is in the present invention. However, for other purposes, general-purpose polyester resins, urethane resins, acrylic resins, copolymers thereof, various water-soluble resins, various functional resins, etc. A polyester-based graft polymer layer may be formed by mixing a resin, for example, a conductive resin such as polyaniline or polypyrrole, an antibacterial resin, an ultraviolet absorbing resin, or a gas barrier resin.

Gas Barrier Laminate Film The gas barrier laminate film of the present invention is preferably prepared by providing a layer containing the above graft polymer and a metal oxide thin film layer in this order on the above polyamide film as the base material. Can be formed. When the polyamide film is a laminated film in which an aromatic polyamide film containing an amide unit composed of terephthalic acid or isophthalic acid and an aliphatic diamine as a constituent component is laminated, these layers are formed on the aromatic polyamide film. .

As the coating liquid, a solution or dispersion of an organic solvent of the graft polymer or a solution or dispersion of an aqueous solvent can be used. In particular, aqueous solutions or aqueous dispersions
This is preferable in that an organic solvent that is problematic for the environment is not used. The solid content of the graft polymer in the organic solvent or the aqueous solvent is usually 1% by weight to 50% by weight, preferably 3% by weight to 30% by weight.

There are no particular restrictions on the drying conditions for the graft polymer after application. However, in order to exhibit the self-crosslinking property of the graft polymer, the polyamide film used as the base material and the graft polymer are not thermally degraded. As long as it does not occur, a condition for increasing the amount of heat is preferable. Specifically, 80 ° C. to 250
° C, more preferably 150 ° C to 220 ° C. However, by extending the drying time, sufficient self-crosslinking property is exhibited even at a relatively low temperature, so that the conditions are not limited to the above.

Various surfactants, antistatic agents, and the like may be added to the graft polymer layer 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, and these are contained in the coating solution and applied to the substrate surface.

In order to form a polyester-based graft polymer layer, a coating solution containing a graft polymer is applied to a polyamide film as a substrate by a gravure method, a reverse method, a die method, a bar method, a dip method. A known coating method such as, for example, may be used.

The coating amount of the coating solution is 0.00
5 to 10 g / m ² , preferably 0.02 to 0.5 g / m ²
m ² . If the coating amount is less than 0.005 g / m ² , sufficient adhesive strength with the polyamide film cannot be obtained. If it is larger than 10 g / m ² , blocking occurs and there is a practical problem.

When applied on a biaxially stretched laminated polyamide film, the laminated polyamide film is subjected to corona treatment, flame treatment, electron beam irradiation, etc., in order to further improve the adhesion between the laminated polyamide film and the polyester-based graft polymer layer. Surface treatment may be performed. Even when the film is stretched after the following coating, the same effect can be obtained.

In the case where the above-mentioned coating solution is applied to an unstretched or uniaxially stretched film, and then dried and stretched, the drying temperature after the application must be dried under conditions that do not affect the subsequent stretching. In the case of a polyamide film, the film is stretched to a moisture content of 2% or less, and then heat-set at 200 ° C. or more to strengthen the coating film, and the adhesiveness between the polyester-based graft polymer layer and the base polyamide film is reduced. Improve dramatically. If the water content is more than 2%, depending on the drying temperature, crystallization is likely to occur, and the flatness may be deteriorated and the stretchability may be impaired.

The film coated with the layer containing the polyester-based graft polymer of the present invention has good adhesiveness to various materials, but in order to further improve the adhesiveness and printability, the film is added to the graft polymer layer. Further, surface treatment such as corona treatment, flame treatment, and electron beam irradiation may be performed.

Metal Oxide Thin Film Layer Next, examples of the metal oxide thin film layer include inorganic thin film layers such as silicon oxide, aluminum oxide, magnesium oxide and mixtures thereof. The silicon oxide herein, consist of a mixture of various silicon oxides such as SiO and SiO _2, and aluminum oxide, it consists of a mixture of various aluminum oxides such as AlO and Al ₂ O _3, in each oxide The amount of oxygen bonded differs depending on the production conditions.

Particularly, a mixture of aluminum oxide and silicon oxide is preferable as the metal oxide thin film layer in the present invention because of its excellent transparency and bending resistance. Further, a mixture of silicon oxide and aluminum oxide in which the content of aluminum oxide in the thin film layer is 5% by weight or more and 45% by weight or less is preferable.

When the amount of aluminum oxide in the silicon oxide / aluminum oxide based thin film layer is less than 5% by weight, there arises a problem that lattice defects occur in the thin film and a sufficient gas barrier property cannot be obtained. When the amount of aluminum oxide in the aluminum-based thin film layer exceeds 45% by weight, the flexibility of the film is reduced, and the film is easily broken (cracked or peeled) due to dimensional change during hot water treatment, and the barrier property is reduced. This causes the problem of the present invention to be lost.

The content of aluminum oxide is more preferably from 10% by weight to 35% by weight, more preferably from 15% by weight to 25% by weight. The metal oxide thin film layer may further contain a small amount (up to 3% by weight) of other oxides and the like as long as the characteristics are not impaired.

The thickness of the metal oxide thin film layer composed of silicon oxide and aluminum oxide is usually from 10 to 5,000.
{, Preferably 50 to 2000}. The film thickness is 10mm
If it is less than 5, it is difficult to obtain a satisfactory gas barrier property.
If the thickness is more than 000 °, the effect of improving the gas barrier property cannot be obtained, which is disadvantageous in terms of bending resistance and manufacturing cost.

For the production of the silicon oxide / aluminum oxide thin film layer, a physical vapor deposition method such as a vacuum vapor deposition method, a sputtering method or 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, a mixture of SiO ₂ and Al ₂ O ₃ , or the like 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 deposition material, reaction gas,
Substrate bias, heating / cooling, etc.
The same applies to the case where the VD method is adopted.

Before or during the vapor deposition, the surface of the substrate is subjected to corona treatment, flame treatment, low-temperature plasma treatment, glow discharge treatment, reverse sputtering treatment, surface roughening treatment, etc.
It is also effective to improve the density strength of the metal oxide thin film layer.

By forming a silicon oxide / aluminum oxide-based thin film layer having such a component composition, a gas barrier laminated film which is transparent and has excellent performance that can withstand a boil treatment and a gelbo test (bending resistance test) can be obtained. It becomes possible.

The gas barrier property of the laminated film according to the present invention is greatly related to the adhesion strength between the base polyamide film and the metal oxide thin film layer, and the gas adhesion property increases as the adhesion strength increases. According to the examination results of the present inventors, in order to have an excellent gas barrier property and maintain the excellent gas barrier property even after the boil treatment, the boil treatment after the boil treatment for 30 minutes in hot water of 95 ° C. It has been confirmed that the adhesion strength of P. should be 100 g / 15 mm or more. 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. If the adhesion strength is less than 100 g / 15 mm, the gas barrier property tends to deteriorate due to the boil treatment.

This is considered to be because if the adhesion strength is high, the metal oxide thin film layer hardly peels off even when the base material slightly shrinks due to the boil treatment or the retort treatment.

Means for obtaining such excellent adhesion strength include corona treatment, plasma treatment, glow discharge treatment, reverse sputtering treatment, and the like, on the surface of the base material of the metal oxide thin film layer.
There are methods such as a roughening treatment and the like and formation of an anchor coat layer for improving adhesion, but of course, the method is not limited to these methods.

Polyolefin film On the surface of the metal oxide thin film layer, the main purpose is as follows.
A polyolefin film for imparting thermal adhesion is laminated, and the polyolefin film also has a function as a protective layer for the metal oxide thin film layer. It is extremely effective to increase the adhesive strength to the film, and as a means for that, it is extremely effective to provide an adhesive layer between the metal oxide thin film layer and the polyolefin film layer.

The polyolefin film does not necessarily have to be a single layer and may be a multilayer. When forming a multilayer structure, the resin constituting each layer may be not only a combination of the same resin but also a copolymer of a different polymer. Products, denatured products, blends, etc. may be laminated. For example, in order to enhance laminating property and heat sealing property, a polymer having a glass transition temperature (Tg) or melting point lower than that of the base thermoplastic polyolefin resin is compounded. It is also possible to composite a polymer having a high molecular weight.

Various additives may be added to the polyolefin film as required, for example, a plasticizer, a heat stabilizer, an ultraviolet absorber, an antioxidant, a coloring agent, a filler, an antistatic agent,
It is also possible to blend antibacterial agents, lubricants, antiblocking agents, other resins, and the like.

Particularly preferred as the resin constituting the adhesive layer is a resin having a glass transition temperature in the range of -10 ° C. to 40 ° C., for example, a polyurethane resin, a polyester resin,
Epoxy resins, vinyl chloride resins, vinyl acetate resins, polyethylene resins, polypropylene resins, melamine resins, acrylic resins, etc., which can be used alone or in combination of two or more if necessary. Or a compound having a carboxylic acid group, an acid anhydride, acrylic acid, methacrylic acid, an acrylate ester skeleton or a methacrylate ester skeleton as a functional group; a glycidyl group or a glycidyl ether group. It is also effective to use an epoxy compound containing a curing agent or a curing accelerator having a reactive functional group such as an oxazoline group, an isocyanate group, an amino group, or a hydroxyl group.

The lamination of the polyolefin film is as follows:
It is laminated on the metal oxide thin film layer by a dry lamination method or a wet lamination method using an adhesive, a melt extrusion lamination method, a co-extrusion lamination method, or the like.

The thus obtained gas-barrier laminated film and sheet of the present invention make use of the excellent gas-barrier properties, the gas-barrier durability by boil treatment and retort treatment, and the secondary processing characteristics, and are used as packaging materials for miso, pickles,
Side dishes, baby food, tsukudani, konjac, chikuwa, kamaboko, processed fishery products, meatballs, hamburgers, genghis khan, ham, sausage, other processed meat products, tea, coffee, tea, bonito, kelp, potato chips, butter peanuts, etc. Oil confections, rice crackers, biscuits, cookies,
It can be effectively used for packaging of cakes, buns, castella, cheese, butter, rice cakes, soups, sauces, ramen, wasabi, toothpaste, etc., and furthermore, pet food, pesticides, fertilizers, infusion packs, or semiconductors It can also be used effectively for packaging of industrial materials such as medical, electronic, chemical, mechanical, etc. The form of the packaging material is not particularly limited, and can be widely applied to bags, lid materials, cups, tubes, standing packs, and the like.

[0101]

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 carry out the present invention with appropriate modifications within a range that can be adapted to the gist of the preceding and following descriptions. Included in the scope. Various performance tests adopted in the following examples were performed by the following methods.

Oxygen permeability: Oxygen permeability measuring device (“OX
-TRAN 10 / 50A "ModernContro
ls), humidity 0%, temperature 25 ° C, pressure 1a
It was measured at tm. Water vapor transmission rate: Water vapor transmission rate measurement device (“PERMAT”
RAN "(manufactured by Modern Controls) at a humidity of 0%, a temperature of 25 ° C., and a pressure of 1 atm. Adhesion strength: Laminate the product using Toyo Sokki Co., Ltd. “Tensilon UTM2” while adhering water to the interface.
The film was peeled off at 80 degrees, and the S-S curve between the metal oxide thin film layer and the base material layer was measured and determined. Flex fatigue resistance test: Flex fatigue resistance test (hereinafter referred to as gelbo test)
Was evaluated using a gelbo flex tester manufactured by Rigaku Corporation. The condition is (MIL-B131H) DE
A test specimen of 112 inches × 8 inches was formed into a cylindrical shape having a diameter of 3 (１ ／) inch, and both ends were held at an initial grasping interval of 7 inches. A stroke of 3 (１ ／) inches and a 400 ° twist was used. Add. The reciprocating motion of this operation is repeated 40 times.
This is performed 1000 times at a speed of times / min. The measurement atmosphere is
20 ° C., relative humidity 65%. The number of pinholes at this time was counted.

Preparation of copolymerized polyester In a stainless steel autoclave equipped with a stirrer, a thermometer, and a partial reflux condenser, 345 parts of dimethyl terephthalate, 211 parts of 1,4-butanediol, 270 parts of ethylene glycol, and 0.5 part of n-butyl titanate was charged and transesterification was carried out from 160 ° C. to 220 ° C. for 4 hours. Then
Add 14 parts of fumaric acid and 160 parts of sebacic acid, add 200 parts
The temperature was raised from 0 ° C to 220 ° C over 1 hour to carry out an esterification reaction. Then, the temperature was raised to 255 ° C., and the pressure of the reaction system was gradually reduced.
The reaction was carried out for one minute to obtain a copolymerized polyester. The obtained polyester was pale yellow and transparent.

The composition (unit mol%) and the weight average molecular weight measured by NMR were as follows. Terephthalic acid: 70, sebacic acid: 26, fumaric acid: 4 ethylene glycol: 50, 1,4-butanediol:
50 weight average molecular weight: 20,000

In a reactor equipped with a stirrer, thermometer, reflux device and quantitative titrator, 75 parts of copolymerized polyester resin, 56 parts of methyl ethyl ketone and 19 parts of isopropyl alcohol
Then, 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 ml / min, and stirring was further continued for 2 hours.
After sampling for analysis from the reaction solution, 5 parts of methanol was added. Next, 300 parts of water and 15 parts of triethylamine were added to the reaction solution, followed by stirring for 1 hour. Thereafter, the reactor internal temperature was raised to 100 ° C., and methyl ethyl ketone, isopropyl alcohol, and excess ammonia were distilled off to obtain a water-dispersed resin of a graft polymer. The water-dispersed resin was pale yellow and transparent. The water-dispersed resin was diluted with water: isopropyl alcohol = 9: 1 (weight ratio) to a solid content concentration of 10% to prepare a coating solution.

Example 1 40 parts by weight of nylon 6 and a mixture of 60 parts by weight of a nylon 6T / nylon 6 copolymer (copolymerization ratio 50/50) were used for the A layer, and 100 parts by weight of nylon 6 were used for the B layer as a T-die. Then, the mixture was melt-extruded while being laminated, and cooled on a rotating drum at 20 ° C. to obtain an unstretched polyamide film having a thickness of 150 μm. This unstretched film was longitudinally stretched 3.1 times at 50 ° C. Then, the film was stretched 3.3 times in the transverse direction at 125 ° C.
Heat fixing was performed at 15 ° C. to obtain a biaxially stretched film having a thickness of 15 μm. At the same time, the aqueous dispersion resin of the above graft polymer was coated on the layer containing the nylon 6T / nylon 6 copolymer by about 0.1 μm.

This film was excellent in both bending fatigue resistance and adhesiveness. This film is sent to a vacuum deposition apparatus, and the inside of the chamber is maintained at a pressure of 1 × 10 ⁻⁵ Torr, and a mixed oxide composed of 70% by weight of SiO ₂ and 30% by weight of Al ₂ O ₃ is heated with an electron beam of 15 kW. A 200 mm thick colorless and transparent metal oxide thin film layer was deposited on the coating surface to form a silicon oxide / aluminum oxide based thin film layer. Next, unstretched polyethylene (thickness: 55 μm) as a polyolefin film was dry-laminated on the metal oxide thin film layer with an adhesive (“A310 / A10” manufactured by Takeda Pharmaceutical Co., Ltd., application amount 2 g / m ² ), and 45 ° C. For 4 days to obtain a gas barrier laminate film. (1) Oxygen permeability (cc / m ² · at) of untreated film
(2) immersion in hot water of 95 ° C. for 30 minutes, and oxygen permeability of the film after standing for 1 hour (cc / m ² · atm · day) (3) 30 days in hot water of 95 ° C. Water permeability (g / m ² · day) of the film after immersion for 1 minute and then left for 1 hour (4) After immersion in hot water of 95 ° C. for 30 minutes, water is dropped on the peeling interface of the film after standing for 1 hour Adhesion force (g / 1
(5 mm) (5) The number of pinholes (pieces) after the bending fatigue test was measured.

Example 2 The procedure of Example 1 was repeated except that the layer A was 25 parts by weight of nylon 6 and a mixture of 75 parts by weight of a nylon 6T / nylon 6 copolymer (copolymerization ratio 50/50). Performed exactly as in Example 1.

Example 3 The procedure of Example 1 was repeated, except that the layer A was changed to 100 parts by weight of nylon 6T / nylon 6 copolymer (copolymerization ratio 50/50).

Comparative Example 1 In the method of Example 1, 100 parts by weight of nylon 6 were used as the A layer, and a polyester coating agent (Toyobo Co., Ltd.
GN131)), except that GN131)) was used.

Comparative Example 2 The procedure of Example 1 was repeated except that the A layer was a mixture of 75 parts by weight of nylon 6 and 25 parts by weight of a nylon 6T / nylon 6 copolymer (copolymerization ratio 50/50). Exactly the same as in Example 1.

Table 1 shows the results.

[0113]

[Table 1]

Example 4 Nylon 6T / nylon 6 copolymer (copolymerization ratio 50/5)
0) was melt-extruded from a T-die to produce a single-layer polyamide film, except that it was carried out in the same manner as in Example 1.

Example 5 The procedure of Example 1 was repeated except that nylon 6 was melt-extruded from a T-die to form a single-layer polyamide film.
(In this case, the graft polymer layer is provided on one side of the nylon 6 film.)

Table 2 shows the results of Examples 4 and 5.

[0117]

[Table 2]

In Tables 1 and 2, (1) to (5) show the following. (1) Oxygen permeability of untreated film (cc / m ² · at
(2) immersion in hot water of 95 ° C. for 30 minutes, and oxygen permeability of the film after standing for 1 hour (cc / m ² · atm · day) (3) 30 days in hot water of 95 ° C. Water permeability (g / m ² · day) of the film after immersion for 1 minute and then left for 1 hour (4) After immersion in hot water of 95 ° C. for 30 minutes, water is dropped on the peeling interface of the film after standing for 1 hour Adhesion force (g / 1
(5mm) (5) Number of pinholes after bending fatigue test (pieces)

[0119]

The packaging material of the present invention using the gas barrier laminate film of the present invention as described above has a small amount of water entering at the interface between the metal oxide thin film layer and the polyamide film surface even in the boil treatment. Therefore, it is considered that peeling and floating of the metal oxide thin film layer from the surface of the polyamide film or deterioration due to chemical change of the metal oxide thin film layer is suppressed. Further, when the polyamide is an aromatic polyamide, the metal oxide thin film layer is considered to be dense and have few defects due to the high hardness of the polyamide film. Therefore, it is considered that good barrier properties are maintained despite the dimensional change of the polyamide film during boiling.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Shinji Fujita 2-1-1 Katata, Otsu-shi, Shiga Prefecture Inside Toyobo Co., Ltd. (72) Inventor Chikao Morishige 2-1-1 Katata, Otsu-shi, Shiga Prefecture No. 1 Toyobo Co., Ltd. Research Laboratory (72) Inventor Kiyoshi Iseki 2-1-1 Katata, Otsu City, Shiga Prefecture Toyobo Co., Ltd. Research Laboratory (72) Inventor Seiichiro Yokoyama 2-1-1 Katata, Otsu City, Shiga Prefecture No. 1 Toyobo Co., Ltd. Research Laboratory (72) Inventor Yozo Yamada 2-1-1 Katada, Otsu-shi, Shiga Prefecture Toyobo Co., Ltd. Research Laboratory F-term (reference) 4F100 AA17C AA17E AA19C AA19E AA20C AA20E AH01B AH01D AH01J AH02B AH02D AH02J AK41B AK41D AK41J AK46A AK46K AK48 AL04B AL04D AL05B AL05D BA03 BA05 BA07 BA10A BA10C BA10E EH66C EH66E EJ37 EJ 42 GB15 GB23 JB06B JB06D JB07 JD02 JK07 JK14 YY00 YY00C YY00E

Claims (8)

[Claims] 1. A layer containing a polyester-based graft polymer in which one or more polymerizable unsaturated monomers are grafted on a hydrophobic polyester, and a metal oxide thin film layer are sequentially formed on at least one surface of a polyamide film. A gas-barrier laminated film characterized by being made. 2. A polyamide film having at least one layer containing at least 50% by weight of an aromatic polyamide containing 10% by mole or more of an amide unit composed of terephthalic acid or isophthalic acid and an aliphatic diamine as a constituent component. The laminated film having gas barrier properties according to claim 1. 3. The adhesive strength between the base polyamide film and the metal oxide thin film layer after boiled in hot water at 95 ° C. for 30 minutes is 100 g / 15 mm or more. Gas barrier laminated film. 4. The gas barrier laminate film according to claim 1, wherein the polymerizable unsaturated monomer contains at least one acid anhydride having a double bond. 5. The gas barrier laminate film according to claim 4, wherein the polymerizable unsaturated monomer contains at least maleic anhydride and styrene. 6. A layer containing a polyester-based graft polymer, a coating solution containing the graft polymer is applied to an unstretched or uniaxially stretched film, dried, and the film is further stretched uniaxially or more. The gas barrier laminate film according to claim 1, which is formed by fixing. 7. The gas barrier laminate film according to claim 1, wherein the metal oxide thin film layer is a thin film layer made of a mixture of silicon oxide and aluminum oxide. 8. The gas barrier laminate film according to claim 1, wherein the content of aluminum oxide in the mixture of silicon oxide and aluminum oxide in the metal oxide thin film layer is 5% by weight or more and 45% by weight or less.