JPS6330582A - Adhesive solution - Google Patents

Abstract

PURPOSE:To improve the adhesive force of an adhesive solution in laminating a metallic foil and a synthetic resin film, by incorporating a specified amount of a chelating agent for metal into an adhesive solution containing an adhesive component. CONSTITUTION:An adhesive component (e.g., polyvinyl acetate or polymethyl methacrylate) is dissolved or dispersed in a solvent (e.g., water or acetone), to which 0.001-5wt%, based on the adhesive component, chelating agent for metal is added. Examples of the chelating agents include ehtylenediamine- tetraacetic acid, pyridine-2-carboxylic acid, and succinic acid. The adhesive solution thus obtained will enable bonding with good strength between a metallic foil and a synthetic resin film, thereby producing a packaging material which comprises a laminate made of a metallic foil and a synthetic resin film and is free from, e.g., delamination.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to an adhesive solution in which adhesive components are dissolved or dispersed, and particularly contributes to improving the adhesive strength between metal foil and synthetic resin film. It concerns adhesive solutions.

(B) Problems to be Solved by the Prior Art and the Invention Conventionally, packaging materials made by laminating metal foil and synthetic resin film have been used. For this bonding, various adhesive solutions are appropriately employed. Adhesive solutions are suitable for bonding metal foils and synthetic resin films because they allow the application thickness to be extremely thin, but there is a problem in that the adhesive strength is weak. If the adhesive strength is insufficient, the bond between the metal foil and the synthetic resin film will peel off when the packaging material is molded or processed into a packaging container, which may reduce the commercial value of the packaging container. There was a possibility that it would be lowered. In order to improve adhesive strength, it is possible to use an adhesive component with high adhesive strength, but it has drawbacks such as insufficient flexibility or poor formability, and it is easy to use adhesive components with high adhesive strength. It was not possible to change the adhesive component.

Therefore, the present invention was made with the aim of improving adhesive strength without changing the adhesive components.

(c) Means and effects for solving the problems, that is, the present invention provides an adhesive solution characterized by containing a chelating agent that chelates metal in an amount of 0.01 to 5% by weight based on the adhesive component. This is related to.

Adhesive components used in the present invention include polyethylene, polypropylene, and polyethyl methacrylate.

Polybutyl methacrylate, polyethyl acrylate.

Polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, vinylidene chloride copolymer, polyvinyl acetal, polyvinyl butyral, polyamide, nitrocellulose, coumaron/indene+11m, 7-rank, etc. are used.

The concentration of the adhesive component in the adhesive solution is preferably about 10 to 80% by weight. Examples of solvents for melting or dispersing adhesive components include methanol, ethanol, carbon tetrachloride, benzene, toluene, xylene, acetone, ethyl acetate, and ethyl ether.

Water etc. are used.

As the chelating agent for chelating the metal used in the present invention, those listed below can be used.

(i) Polycarboxylic acids and their analogs.

Oxalic acid, succinic acid, maleic acid, phthalic acid.

Tricarballylic acid, butane-1,2,3,4-tetracarboxylic acid, diglycolic acid, mercaptosuccinic acid.

2-carboxyanisic acid, etc.

(ii) Oxycarboxylic acids and their analogs.

Glycolic acid, β-hydroxypropionic acid.

Tartaric acid, isocitric acid, pyruvic acid, mandelic acid.

salicylic acid etc.

(iii) Polyamines and the like (eg, multi-nitrogen-containing heterocyclic compounds).

Ethylenediamine, propylenediamine, N-isopropylethylenediamine, N,N'-dimethylethylenediamine, N,N'-dimethylethylenediamine.

N,N'-dipropylethylenediamine, trimethylenediamine, 1,3-diamino-2-aminomethylpropane, diethylenetriamine, 2.212-thylpyridyl.

L2,3-) riaminopropane, β, β', β''-triaminotriethylamine, imidazole, purine.

2-amino-6-mercaptopurine, 5-methyl-〇-
Phenanthroline, 5-bromo-O-phenanthroline, etc.

(iv) Aminocarboxylic acids and analogs thereof (eg, carboxylated heterocyclic nitrogen-containing compounds).

Pyridine-2-carboxylic acid, pyridine-2,6-dicarboxylic acid, iminodiacetic acid, N-(3,3-dimethylbutyl)iminodiacetic acid, mercaptoethyliminodiacetic acid, 2
-Hydroxycyclohexyliminodiacetic acid.

2-Hydroxybenzyliminodiacetic acid, N-(m-carboxyphenyl)iminodiacetic acid, aminoethyliminodiacetic acid, phosphonomethyliminodiacetic acid, 0-sulfophenyliminodiacetic acid, N,N-ethylenediamine di[t,
N,N'-di(hydroxyethyl)ethylenediaminediacetic acid, N-(o-hydroxycyclohexyl)ethylenediaminetriacetic acid, ethylenediaminetetraacetic acid, propylenediaminetetraacetic acid.

Pentamethylenediaminetetraacetic acid, cyclobencune-
1,2-diaminetetraacetic acid, cyclohexane-1,4
-Diaminetetraacetic acid, 2-hydroxytrimethylenediaminetetraacetic acid, aspartic acid, glycylglycine, dipicolinic acid, bis(iminodiacetate)methylamine, quinoline-2-carboxylic acid, dimethyldithiocarbamic acid, etc.

(v) Hydroxylamine and its analogues (eg, hydroxylated multi-S ring nitrogen-containing compounds).

Pyridoxamine, hyboxanthin, xanthosine, β,
β′, β″-trihydroxytriethylamine, β-amino-β′-hydroxydiethyl sulfide, cytidine-sulfuric acid, uridine-oral phosphoric acid.

Adenosine-5'-phosphate, flavin mononucleotide, 4-methyloxine, 7-methyloxine, 4-hydroxy-1,5-naphthyridine, 5-hydroxyquinoxaline, 4,7-diphenyl-〇-phenanthroline.

1-nitroso-β-naphthol etc.

(vi) Other chelating agents such as polyketones and polyoxy.

Tripolin, 4-methyltropolin, chromotropic acid 1-acetylacetone, benzoylacetone.

Furoylacetone, 2-(α-thenyl)pyridine.

5-hydroxyflavone, etc.

Among the above chelating agents, aminocarboxylic acids (1v) are preferred, and ethylenediaminetetraacetic acid is particularly preferred. This is because it has an excellent chelating effect, is inexpensive, and is easily available.

The amount of chelating agent blended into the adhesive solution ranges from 0.01 to 5% by weight based on the adhesive components.

If the amount of the chelating agent is less than 0.01, no improvement in adhesion is observed, which is undesirable.Also, even if the amount of the chelating agent exceeds 5% by weight, the improvement in adhesion reaches a saturated state. This is not preferable because it is not economical and may actually reduce the adhesive strength.

(d) Examples Example 1 An adhesive solution (emulsion solution) having the following formulation was prepared.

Polyvinyl acetate 100 parts by weight Ethylenediaminetetraacetic acid 0.5 parts by weight Water
250 parts by weight Sodium alkylbenzenesulfonate 51 parts This adhesive solution was applied to a 150μ aluminum foil using a #6 bar coater, and then the applied adhesive solution was dried. Thereafter, a polyethylene film having a thickness of 100 μm was layered and bonded by heating and pressing at 80° C. to obtain a bonded product of aluminum foil and film.

In order to evaluate the adhesive strength of this laminate, the 180° peel strength was measured and found to be 870 g/15 m width at a peel rate of 200 tm/min.

Comparative Example 1a Aluminum foil and polyethylene film were laminated using the same formulation as the adhesive solution of Example 1 except that ethylenediaminetetraacetic acid was not used, and the peel strength was measured under the same conditions. It was 15m wide.

Comparative Example 1b An adhesive solution (emulsion solution) having the following formulation was prepared.

Polyvinyl acetate 100 parts by weight Ethylenediaminetetraacetic acid 0.007 parts by weight Water
250 parts by weight Sodium alkylbenzene sulfonate 5 parts by weight Using this adhesive solution, an aluminum foil and a polyethylene film were combined in the same manner as in Example 1, and the peel strength was measured under the same conditions. Met.

Comparative Example 1c An adhesive solution (emulsion solution) having the following formulation was prepared.

Polyvinyl acetate 100 parts by weight Ethylenediaminetetra vinegar w1 7 parts by weight Water
250 parts by weight Sodium alkylbenzenesulfonate 5 parts by weight Using this adhesive solution, aluminum foil and polyethylene film were laminated in the same manner as in Example 1, and the peel strength was measured under the same conditions. Met.

Example 2 An adhesive solution having the following formulation was prepared.

Polymethyl methacrylate 100 parts by weight Succinic acid 7 parts by weight Acetone
300 parts by weight of this adhesive solution
The adhesive solution was applied to 0μ aluminum foil using a #6 bar coater and then dried. After that, a polyester film with a thickness of 100 μm was layered and
Heat at °C.

Pressure was applied to adhere the aluminum foil and the film to obtain a bonded product.

Peel strength was measured under the same conditions as Example 1, and it was found to be 3
It was 60 g/15 Tsuruhiba.

Comparative Example 2 An aluminum foil and a polyester film were laminated using an adhesive solution with the same formulation as in Example 2, except that succinic acid was not used, and the peel strength was measured under the same conditions. It was 150 g/15 m It was wide.

Example 3 An adhesive solution having the following formulation was prepared.

Polyvinyl butyral 100 parts by weight Ethylenediaminetetraacetic acid 0.3 ffii 1 part Ethanol 300 parts by weight This adhesive solution was applied to a 150μ aluminum foil using a #6 bar coater, and then the applied adhesive solution was dried. Thereafter, polyethylene films having a thickness of 100 μm were stacked and bonded together by heating and pressing at 90° C. to obtain a bonded product of aluminum foil and film.

Peel strength was measured under the same conditions as Example 1 and found to be 9.
It was 40g/15m width.

Comparative Example 3 An aluminum foil and a polyethylene film were laminated using the same formulation as the adhesive f64L of Example 3, except that ethylenediaminetetraacetic acid was not used, and the peel strength was measured under the same conditions. It was 151m wide.

(e) As described in detail of the invention, if the adhesive solution according to the present invention to which a chelating agent for chelating metal is added is used, the conventional adhesive solution to which no chelating agent is added is used. The adhesive force between the metal foil and the synthetic resin film is improved compared to the case where the metal foil and the synthetic resin film are bonded to each other. Therefore, by using a laminate of metal foil and synthetic resin film as a packaging material, the metal foil and synthetic resin film are unlikely to peel off even after various molding or processing, and packaging containers with high commercial value can be used. can be obtained.

Claims (1)

[Claims] An adhesive solution containing a chelating agent that chelates a metal in an amount of 0.01 to 5% by weight based on the adhesive component.