JPH0939181A - Laminated polyamide film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the adhesion between a base material layer and a sealant layer and thereby, secure their improved adhesion even in a wet condition by providing a modified adhesive layer consisting of a polymer composition containing a polymer with a specific oxazoline group at least, on one of the surfaces a base material. SOLUTION: An adhesive modified layer consisting of a polymer composition containing a polymer with an oxazoline group formed of a monomer containing polyester and an oxazolire compound expressed by formula, is laminated, at least, on one of the surfaces of a polyamide film base material to obtain this laminated polyamide film. In the formula, R1 , R2 , R3 and R4 are independent respectively to be hydrogen, halogen, alkyl, phenyl or substituted phenyl; R5 is an acyolic organic group having a polymeripble unsaturated bond. Consequently, this laminated polyamide film has excellent water-proof adhesion, and superior hot water-proof adhesive force with a sealant material, so that the percentage of bag breakage by retort treatment or boiling water treatment can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide film with improved adhesion, and more particularly to a dry laminate,
The present invention relates to a laminated polyamide film having excellent adhesiveness with a sealant material for heat sealing formed on the film by using extrusion lamination or the like.

[0002]

2. Description of the Related Art Biaxially stretched polyamide films are tough,
Since it has excellent pinhole resistance, bending resistance, and heat resistance, it is widely used in various applications. For example, it is used as a packaging film having a heat sealing function. In this case, generally, a heat-sealable polyamide film obtained by forming an adhesive layer on the surface of a biaxially stretched polyamide film, and providing a sealant layer on the adhesive layer by a dry laminating method or an extrusion laminating method. A laminate is used. After printing the film laminate as required, it is formed into a bag, for example, and the contents, such as seasonings such as miso and soy sauce, water-containing foods or chemicals such as soups and retort foods, etc. After filling with, the open part is heat-sealed to form a packaged product provided to general consumers.

[0003]

Generally, when water penetrates between the layers forming the polyamide film laminate having the sealant layer as described above, there is a problem that the adhesive force between the layers is significantly reduced. This causes damage when used as a packaging bag. For example, when a retort food bag using a polyamide film laminate having a sealant layer is subjected to boiling water treatment or retort treatment, this problem becomes prominent and the bag is more easily damaged.

Further, as the packaging products become more sophisticated, full-color multicolor printing becomes widespread, and there arises a problem that the adhesive strength between layers is lowered due to the presence of the printing ink layer.

Further, when an adhesive layer is interposed between the biaxially stretched polyamide film layer and the sealant layer, the adhesive force is easily affected by humidity depending on the kind of the adhesive, and particularly the humidity-curable adhesive. When using, the effect is remarkable, and there is a problem that the adhesive strength changes greatly depending on the season.

[0006]

Means for Solving the Problems The present inventors have found that the polyamide film laminate having a sealant layer has good adhesion between the polyamide film base material layer and the sealant layer, and also maintains high adhesion even when wet. An intensive study was conducted for the purpose of obtaining a polyamide film laminate that sags. As a result, when a polyamide film having a specific adhesion modifying layer is used for a polyamide film laminate having a printing ink layer, an adhesive layer and a sealant layer, a packaging bag formed from this polyamide film laminate has a retort. The inventors have found that damage due to treatment or boiling water treatment can be significantly reduced, leading to the present invention.

The present invention relates to a polymer composition containing a polymer having an oxazoline group formed from a monomer containing a polyester and an oxazoline compound represented by the formula (I) on at least one surface of a polyamide film substrate. A laminated polyamide film having the following adhesiveness-modifying layer, and thereby the above-mentioned object is achieved.

[0008]

Embedded image

Here, R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen, halogen, alkyl, phenyl,
Alternatively, it is a substituted phenyl, and R ⁵ is an acyclic organic group having a polymerizable unsaturated bond.

In a preferred embodiment of the present invention, the polyester has a group capable of reacting with an oxazoline group. In a preferred embodiment of the present invention, the adhesion-modified layer is formed by applying a coating solution containing the polymer composition onto an unstretched or uniaxially stretched polyamide film and then biaxially stretching or uniaxially stretching the film. Is formed by

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the present specification, the term "alkyl" means a linear or branched alkyl group having a substituent such as halogen, aryl, cyano, alkyloxy or alkyloxycarbonylmethyl. Or, it means an alkyl group which does not have.

In the present specification, "substituted phenyl" means
A phenyl group having a substituent such as halogen, alkyl, cyano, alkyloxy, alkyloxycarbonyl, and alkyloxycarbonylmethyl.

(Oxazoline Compound) The oxazoline compound which can be used in the present invention is represented by the formula (I).

[0014]

Embedded image

Here, R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen, halogen, alkyl, phenyl,
Or a substituted phenyl. R ⁵ is an acyclic organic group having a polymerizable unsaturated bond such as vinyl and allyl.

Examples of alkyl include methyl, ethyl, propyl, isopropyl, isobutyl, hexyl, 2-ethylhexyl, benzyl, 2-phenylethyl, 2-cyanoethyl, trifluoromethyl, pentafluoroethyl, 2-methoxyethyl and 2-methoxy. Carbonyl ethyl etc. can be mentioned.

The substituted phenyl includes o-, m- or p-chlorophenyl, dichlorophenyl, tolyl, xylyl,
Mention may be made of o-, m- or p-cyanophenyl, o-, m- or p-methoxyphenyl, o-, m- or p- (methoxycarbonylmethyl) phenyl and the like.

Examples of the oxazoline compound include 2-vinyl-2-oxazoline; 2-vinyl-4-halo-2-
Oxazoline and 2-vinyl-5-halo-2-oxazoline; 2-vinyl-4-alkyl-2-oxazoline and 2-vinyl-5-alkyl-2-oxazoline,
For example, 2-vinyl-4-methyl-2-oxazoline and 2-vinyl-5-methyl-2-oxazoline; 2-
Vinyl-4-alkyl-5-halo-2-oxazoline and 2-vinyl-4-halo-5-alkyl-2-oxazoline; 2-vinyl-4-alkyl-5-alkyl-2
-Oxazoline (alkyls at 4- and 5-positions are different or the same); 2-vinyl-4-phenyl-
2-oxazoline and 2-vinyl-5-phenyl-2
-Oxazoline; 2-vinyl-4-phenyl-5-halo-2-oxazoline and 2-vinyl-4-halo-5.
Phenyl-2-oxazoline; 2-vinyl-4-phenyl-5-alkyl-2-oxazoline and 2-vinyl-4-alkyl-5-phenyl-2-oxazoline; 2
-Vinyl-4-phenyl-5-phenyl-2-oxazoline; 2-vinyl-4-substituted phenyl-2-oxazoline and 2-vinyl-5-substituted phenyl-2-oxazoline; 2-vinyl-4-substituted phenyl- 5-halo-2-
Oxazoline and 2-vinyl-4-halo-5-substituted phenyl-2-oxazoline; 2-vinyl-4-substituted phenyl-5-alkyl-2-oxazoline and 2-vinyl-4-alkyl-5-substituted phenyl-2 -Oxazoline; 2-vinyl-4-substituted phenyl-5-phenyl-2
-Oxazoline and 2-vinyl-4-phenyl-5-
Substituted phenyl-2-oxazoline; 2-vinyl-4-substituted phenyl-5-substituted phenyl-2-oxazoline (4
And the substituted phenyls at positions 5 and 5 are each different or the same); and these vinyls are replaced by isopropenyl. These may be used alone or in combination of two or more. Of these, 2-isopropenyl-2-oxazoline is preferable because it is industrially easily available.

(Polymer Having Oxazoline Group) The polymer having an oxazoline group which can be used in the present invention is a homopolymer of the above oxazoline compound or an acyclic organic group having a polymerizable unsaturated bond of the above oxazoline compound and the oxazoline compound. Copolymer with a monomer having a polymerizable unsaturated bond copolymerizable with and not reacting with an oxazoline ring, or a homopolymer of the above oxazoline compound and a polymer of a monomer not reacting with an oxazoline ring Can be a mixture with.

Examples of such a monomer include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate,
Acrylic acid esters such as 2-hydroxyethyl acrylate and hydroxypropyl acrylate; methyl methacrylate, ethyl methacrylate, isopropyl methacrylate,
Methacrylic acid esters such as n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate and hydroxylpropyl methacrylate; nitriles such as acrylonitrile and methacrylonitrile; acrylamide, N -Acid amides such as methylol acrylamide and diacetone acrylamide; vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl methyl ketone, vinyl Vinyl ketones such as hexyl ketone and methyl isopropenyl ketone; N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylpyrroli N-vinyl compounds such as vinyl chloride; vinyl halides such as vinyl chloride, vinylden chloride, vinyl bromide, vinyl fluoride; aromatics such as styrene, α-methylstyrene, t-butylstyrene, vinyltoluene, vinylnaphthalene Vinyl compounds; α-olefins such as ethylene and propylene; These monomers may be used alone or in combination of two or more.

The amount of the oxazoline compound used is 1% by weight to 80% by weight, preferably 2% by weight to 7% by weight based on the total amount of the monomers.
It is 0% by weight, more preferably 5% by weight to 60% by weight. If it is less than 5% by weight, sufficient durability and water resistance of the adhesion-modified layer cannot be obtained. The polymer having an oxazoline group that can be used in the present invention can be prepared by a known polymerization method such as a bulk polymerization method, a solution polymerization method, a suspension polymerization method or an emulsion polymerization method.

In the case of forming the adhesion modifying layer on the polyamide film substrate, the polymer composition containing a polymer formed from a monomer containing an oxazoline compound and a polyester is dissolved or dispersed in an organic solvent, or It is preferable to dissolve or disperse in an aqueous solvent to prepare a coating solution.
In particular, when used by being dissolved or dispersed in an aqueous solvent,
It is preferable in that an organic solvent that poses a problem to the environment is not used. By using an aqueous solution or dispersion of the above-mentioned polymer composition, the adhesion-modified layer can be easily formed on the polyamide film substrate by a known method without environmental pollution.

Therefore, it is preferable to use an emulsion polymerization method for preparing the polymer having an oxazoline group.

(Polyester) The polyester which can be used in the present invention is preferably a saturated or unsaturated polyester synthesized from at least a dicarboxylic acid component and a diol component, and the obtained polyester is one kind of polymer or two kinds. It may be a mixture of the above polymers.

The polyester in the present invention contains a functional group which reacts with an oxazoline group. By the reaction of such a functional group and the oxazoline group, the polymer having the oxazoline group and the polyester are crosslinked to form a strong three-dimensional structure of the polymer. This improves the durability and water resistance of the adhesiveness-modified layer.

The weight average molecular weight of the polyester usable in the present invention is 1,000 to 500,000, preferably 5,000 to 2
It is 0,000.

Examples of the functional group which reacts with an oxazoline group include a carboxyl group and a salt thereof, a carboxylic acid anhydride, a sulfonic acid group and a salt thereof, a mercapto group and an amino group. Polyesters having groups can be used. From the viewpoint of reactivity with oxazoline groups, carboxyl groups, carboxylic acid anhydrides,
Sulfonic acid groups are preferred.

As the above-mentioned dicarboxylic acid component, aromatic dicarboxylic acid, aliphatic dicarboxylic acid, alicyclic dicarboxylic acid and the like can be used.

As the aromatic dicarboxylic acid, terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid and the like can be used.
Furthermore, sodium 5-sulfoisophthalate can also be used if necessary.

As the aliphatic dicarboxylic acid, succinic acid,
Adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid, acid anhydrides thereof and the like can be used.

As the alicyclic dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, acid anhydrides thereof, and the like can be used.

The diol component is an aliphatic glycol having 2 to 10 carbon atoms, an alicyclic glycol having 6 to 12 carbon atoms,
And at least one of ether bond-containing glycols.

As the aliphatic glycol having 2 to 10 carbon atoms, ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-
Pentanediol, 1,9-nonanediol, 2-ethyl-2-butylpropanediol and the like can be used.

As the alicyclic glycol having 6 to 12 carbon atoms, 1,4-cyclohexanedimethanol or the like can be used.

Examples of the ether bond-containing glycol include diethylene glycol, triethylene glycol, dipropylene glycol, and glycols obtained by adding one to several moles of ethylene oxide or propylene oxide to two phenolic hydroxyl groups of bisphenols, for example. 2,2-bis (4-hydroxyethoxyphenyl) propane or the like can be used. Polyethylene glycol, polypropylene glycol, and polytetramethylene glycol can also be used as needed.

In addition to the above dicarboxylic acid component and diol component, a trifunctional or higher functional polycarboxylic acid and / or polyol may be copolymerized.

Examples of the trifunctional or higher polycarboxylic acid include (anhydrous) trimellitic acid, (anhydrous) pyromellitic acid, (anhydrous) benzophenonetetracarboxylic acid, trimesic acid,
Ethylene glycol bis (anhydro trimellitate), glycerol tris (anhydro trimellitate) and the like can be used.

As the trifunctional or higher-functional polyol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, etc. may be used.

The polyester that can be used in the present invention has a functional group that reacts with the oxazoline group, and may be soluble in an organic solvent or water-soluble or water-dispersible. As described above, it is preferably water-dispersible from the viewpoint of easy formation of the adhesion-modified layer and environmental pollution.

(Polyamide film base material) As the polyamide which can be used for the polyamide film base material in the present invention, for example, nylon 6, whose main raw material is ε-caprolactam, is a lactam having 3 or more membered rings, ω-amino acid, dibase. Polyamide obtained by polycondensation of acid and diamine may be used.

As the lactams, in addition to ε-caprolactam, enanthlactam, capryllactam, lauryllactam and the like can be used.

The ω-amino acids include 6-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 1
1-aminoundecanoic acid or the like can be used.

Examples of the dibasic acid include adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecadioic acid, hexadecadioic acid, eicosandioic acid, eicosadiendioic acid, 2 2,2,4-trimethyladipic acid, terephthalic acid isophthalic acid, 2,6-naphthalenedicarboxylic acid, xylylenedicarboxylic acid and the like can be used.

As diamines, ethylenediamine,
Trimethylenediamine, tetramethylenediamine, hexamethylenediamine, pentamethylenediamine, undecamethylenediamine, 2,2,4 (or 2,4,4)
-Trimethylhexamethylenediamine, cyclohexanediamine, bis- (4,4'-aminocyclohexyl)
Methane, metaxylylenediamine and the like can be used.

Examples of the polymer or copolymer obtained by polycondensation of dibasic acid and diamine include nylon 6, 7, 11, 12, 6.6, 6.9, 6.11, 6.
12, 6T, 6I, MXD6, 6 / 6.6, 6/12,
6 / 6T, 6 / 6I, 6 / MXD6 and the like can be mentioned.

The polyamide film substrate which can be used in the present invention may contain various additives as long as the intended performance is not impaired. As the additive, for example, an antioxidant,
Light stabilizers, antigelling agents, lubricants, antiblocking agents, pigments, antistatic agents, surfactants and the like.

The polyamide film substrate that can be used in the present invention can be formed by a known film forming method. As a film forming method, a T-die method, an inflation method or the like can be used.

The polyamide film substrate usable in the present invention may be a single layer or a multi-layer film formed by coextrusion or the like.

(Laminated Polyamide Film) The laminated polyamide film of the present invention has an adhesion modifying layer made of a polymer composition containing a polyester and a polymer having an oxazoline group on at least one surface of the polyamide film substrate.

The blending ratio of the above polyester and the above oxazoline group-containing polymer in the adhesion modifying layer is
1:99 to 90:10, preferably 2:98 to 70: 3
0. If the amount is out of the above range, sufficient water resistant adhesiveness cannot be obtained.

The adhesive property modifying layer is formed by applying a coating solution containing an organic solvent solution, an aqueous solution or an aqueous dispersion of a polymer composition containing the above polyester and the above-mentioned polymer having an oxazoline group to a gravure system, a reverse system or a die system. It can be formed by coating on a polyamide film substrate by a known coating method such as a bar method or a dip method. In this case, it is preferable to use the aqueous dispersion from the viewpoint of environmental pollution as described above. An aqueous dispersion of the polymer composition can be prepared by mixing an emulsion of a polymer having an oxazoline group obtained by an emulsion polymerization method and an aqueous dispersion of polyester.

The coating amount of the coating liquid is 0.01 as the solid content.
~ 1 g / m ^2, preferably from 0.05 to 0.5 g / m ^2. If the coating amount is 0.01 g / m ² or less, sufficient adhesive strength between the adhesion-modifying layer and other layers cannot be obtained. 1 g /
If it is more than m ² , blocking occurs, which is a practical problem.

Additives such as an antistatic agent, an inorganic lubricant and an organic lubricant can be added to the adhesive property-improving layer within a range that does not impair the effects of the present invention. It is applied to the substrate surface.

The laminated polyamide film of the present invention is obtained by applying the above coating solution to a biaxially stretched polyamide film base material, or by applying the above coating solution to an unstretched or uniaxially stretched polyamide film base material, and then drying. If necessary,
Furthermore, it can be prepared by uniaxially stretching or biaxially stretching and then heat setting. The adhesion-modified layer used in the present invention is a step of preparing a polyamide film substrate, that is, after applying a coating solution to a polyamide film substrate that has not been stretched or after uniaxial stretching, it is dried and, if necessary, further It is preferably formed by uniaxial stretching or biaxial stretching and then heat setting.

When a biaxially stretched polyamide film base material is used, the drying temperature after coating is 150 ° C. or higher, preferably 200 ° C. or higher. Adhesion between the modified layer and the polyamide film substrate is improved.

When the film is stretched after coating, it is necessary to control the water content of the coated film within the range of 0.1 to 2% in order to prevent the stretchability of the coated film from being impaired. After stretching, by drying at 200 ° C. or higher and heat-setting, the coating film becomes strong and the adhesiveness between the adhesion-modified layer and the polyamide film substrate is dramatically improved.

The polymer composition contained in the adhesion modifying layer used in the laminated polyamide film of the present invention contains a polyester having a functional group which reacts with an oxazoline group in a polymer having an oxazoline group. Due to the reaction between the functional group of the polyester and the oxazoline group, the polymer having the oxazoline group and the polyester are cross-linked to form a strong three-dimensional structure of the polymer. Is improved.

[0058]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. In the examples, “parts” means “parts by weight”, and “%” means “% by weight”. Each measurement item followed the following method.

(1) Peel strength The peel strength of the polyamide film laminate during normal storage (dry and wet) was measured with a tensile tester at a pulling speed of 1
It was measured by a 90 ° peel test at 00 mm / min.

(2) Measurement of Peel Strength in Hot Water The peel strength of the polyamide film laminate in hot water at 90 ° C. was 90 at a tensile speed of 100 mm / min using a tensile tester.
Measured in a peel test.

(3) Measurement of resistance to air-containing boil puncture The polyamide film laminate was made into a three-sided bag having an internal size of 10 cm × 10 cm, and 100 ml of water and 40 m of air were placed inside.
After filling with 1 liter, it was sealed. The sealed bag was boiled for 10 minutes, and the bag breakage rate was calculated by the following formula.

[0062]

[Equation 1]

Example 1 An aqueous dispersion containing 40% by weight of a polymer having an oxazoline group obtained by copolymerizing 40 parts of butyl acrylate, 40 parts of styrene and 20 parts of 2-isopropenyl-2-oxazoline. 3.8 parts by weight, an aqueous dispersion of a water-dispersible polyester resin (Vylonal MD-1930 manufactured by Toyobo Co., Ltd., solid content concentration 30% by weight) 1
A coating solution consisting of 1.7 parts by weight, 10.0 parts by weight of isopropanol and 74.5 parts by weight of water is applied to a biaxially stretched polyamide film having a thickness of 15 μm by a gravure method to give a weight of 0.2 g / m ² after drying Thus coated on the film and dried at 150 ° C. to obtain a laminated polyamide film.

(Preparation of Laminate) A gravure ink (Lamiace 6) was applied to the surface of the laminated polyamide film coated with the coating liquid.
Gravure printing of 1-white 2-liquid type, manufactured by Toyo Ink Co., Ltd. to form a printing ink layer, and then a 1-liquid moisture-curing AC agent (T-104, manufactured by Nippon Soda Co., Ltd.) is applied to form an AC.
The agent layer was formed. Then, LDPE extrusion lamination is performed on the AC agent layer according to a conventional method to provide a sealant layer,
A polyamide film laminate was obtained. Table 1 shows the evaluation results of the above evaluation items of this laminate.

Example 2 An aqueous dispersion containing 40% by weight of a polymer having an oxazoline group obtained by copolymerizing 40 parts of butyl acrylate, 40 parts of styrene and 20 parts of 2-isopropenyl-2-oxazoline. 2.5 parts by weight of water-dispersible polyester resin aqueous dispersion (Vylonal MD-1930 manufactured by Toyobo Co., Ltd., solid content concentration 30% by weight) 3
A coating solution consisting of 0.0 parts by weight, 5.0 parts by weight of isopropanol and 62.5 parts by weight of water was prepared.

The polyamide was mixed with a screw type extruder 26
It was melted by heating at 0 ° C and extruded from a T-die. Next, this unstretched sheet was longitudinally stretched 3.2 times at 50 ° C. with a cooling drum. The coating solution was applied to the obtained polyamide film substrate by the gravure method so that the coating amount was 4 g / m ² , and then dried so that the water content of the coated polyamide film was 1%. 4 times horizontal stretching to 2
Heat fixing was performed at 20 ° C., and then the coated surface was subjected to corona treatment to obtain a laminated polyamide film having a thickness of 15 μm. The coating amount after drying was 0.1 g / m ² . Then, a polyamide film laminate was prepared and evaluated in the same manner as in Example 1. Table 1 shows the evaluation results.

Example 3 An aqueous dispersion containing 40% by weight of a polymer having an oxazoline group obtained by copolymerizing 45 parts of butyl acrylate, 45 parts of styrene and 10 parts of 2-isopropenyl-2-oxazoline. 7.5 parts by weight, an aqueous dispersion of a water-dispersible polyester resin (Vylonal MD-1330 manufactured by Toyobo Co., Ltd., solid content concentration 30% by weight) 2
A laminated polyamide film was obtained in the same manner as in Example 2 except that a coating liquid consisting of 3.3 parts by weight, 5.0 parts by weight of isopropanol and 64.2 parts by weight of water was used, and then a laminate was prepared. And evaluated. Table 1 shows the evaluation results.

Example 4 In the method of Example 2, the compounding ratio of the polymer having an oxazoline group and the water-dispersible polyester resin was changed so that the solid content ratio was 4: 6, and The coating amount after drying the coating liquid is 0.07 g / m ²
A laminated polyamide film was obtained in the same manner as in Example 2 except that the above was adopted, and then a laminated body was prepared and evaluated. Table 1 shows the evaluation results.

Comparative Example 1 A laminated polyamide film was obtained in the same manner as in Example 1 except that the polymer having an oxazoline group was not used. Then, a laminated body was prepared and evaluated. did. Table 1 shows the evaluation results.

(Comparative Example 2) A laminated polyamide film was obtained in the same manner as in Example 1 except that an aqueous dispersion of a water-dispersible polyester resin was not used in the method of Example 1, and then a laminate was prepared. And evaluated. Table 1 shows the evaluation results.

Comparative Example 3 In the method of Example 2, no polymer having an oxazoline group was used, and
A laminated polyamide film was prepared in the same manner as in Example 2 except that the blending amount of the water-dispersible polyester resin was changed so that the coating amount after drying of the coating liquid was 0.1 g / m ^2. Obtained, and then a laminate was prepared and evaluated. Table 1 shows the evaluation results.

(Comparative Example 4) In the method of Example 2, no aqueous dispersion of water-dispersible polyester resin is used,
A laminated polyamide was prepared in the same manner as in Example 2, except that the amount of the aqueous dispersion of the polymer having an oxazoline group was changed so that the coating amount of the coating liquid after drying was 0.1 g / m ^2. Films were obtained and then laminates were prepared and evaluated. Table 1 shows the evaluation results.

(Comparative Example 5) A surface tension of 53 was obtained by corona treatment.
Gravure ink (Lamiace 61 white two-liquid type, manufactured by Toyo Ink Co., Ltd.) is gravure-printed on the corona-treated surface of a biaxially stretched polyamide film with a thickness of 15 μm, which is dyne / cm, and then a printing ink layer is formed on it. A one-pack moisture-curable AC agent (T-104, manufactured by Nippon Soda Co., Ltd.) was applied to form an AC agent layer. Then, LDPE extrusion lamination was performed on the AC agent layer by a conventional method to form a sealant layer, and a polyamide film laminate was prepared and evaluated.
Table 1 shows the evaluation results.

[0074]

[Table 1]

[0075]

EFFECT OF THE INVENTION The laminated polyamide film of the present invention has good water-resistant adhesiveness, and particularly has excellent heat-resistant water-resistant adhesiveness with a sealant material laminated by dry lamination or extrusion lamination. Since the bag-formed product formed from the laminated polyamide film of the present invention has excellent resistance to hot water, the bag breakage due to retort treatment or boiling water treatment is extremely small, and thus it can be widely used as a packaging bag for moisture-containing foods and chemicals.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08L 67/02 LPK C08L 67/02 LPK 77/00 77/00 // C08G 81/00 NUS C08G 81/00 NUS (72) Inventor Mitsuru Kuwahara 1-1-1 Katata, Otsu City, Shiga Toyobo Co., Ltd. Research Institute (72) Inventor Tsutomu Isaka 2-8 Dojimahama, Kita-ku, Osaka-shi, Osaka Toyobo Co., Ltd. In-house

Claims (3)

[Claims] 1. An adhesive comprising a polymer composition containing a polymer having an oxazoline group formed from a monomer containing a polyester and an oxazoline compound represented by the formula (I) on at least one surface of a polyamide film substrate. Laminated Polyamide Film Having Property Modification Layer: Here, R ¹ , R ² , R ³ , and R ⁴ are each independently hydrogen, halogen, alkyl, phenyl, or substituted phenyl, and R ⁵ is an acyclic organic group having a polymerizable unsaturated bond. is there. 2. The laminated polyamide film according to claim 1, wherein the polyester has a group capable of reacting with an oxazoline group. 3. The adhesion modifying layer is obtained by applying a coating solution containing the polymer composition onto an unstretched or uniaxially stretched polyamide film and then biaxially stretching or uniaxially stretching the film. The laminated polyamide film according to claim 1, which is formed.