JP6844928B2 - Adhesive for film-laminated metal cans - Google Patents

Description

The present invention relates to an adhesive for a film-laminated metal can having excellent printability and processability.

Multicolor printing is generally applied to the outer surface of the can, and from the viewpoint of the appearance of printing, there is a colored layer under the printing ink layer, and usually, as the colored layer, a colored paint for the outer surface of the can (hereinafter referred to as a colored paint) containing a white pigment. , The colored paint for the outer surface of the can is referred to as "white coat") is coated on the metal material, and the polyester film is laminated on the printing ink layer.

Therefore, if an adhesive containing a white pigment, especially titanium white, is used as the white coat, the adhesive layer formed by the adhesive can also serve as the colored layer formed by the white coat. The manufacturing process can be omitted, which is very convenient in terms of process saving (see FIG. 1 for the film structure).

For example, Patent Document 1 describes a number in a specific range as an adhesive for a film-laminated metal can having a low solvent content (high solid), which is excellent in whiteness (whiteness) and adhesion without color unevenness, darkening, etc. For film-laminated metal cans containing a hydroxyl group-containing polyester resin having an average molecular weight and a hydroxyl value, crosslinked resin particles having a specific monomer composition and an average particle size in a specific range, a polyisocyanate compound, and rutile-type titanium dioxide. Adhesives are disclosed.

Further, Patent Document 2 describes a specific hydroxyl group-containing polyester resin and polyisocyanate as an adhesive for a film-laminated metal can, which has good storage stability, whiteness of a film, heat-resistant yellowing, and adhesiveness. Adhesives for film-laminated metal cans containing compounds, fluorescent compounds, and rutile titanium dioxide are disclosed.

However, the adhesives described in Patent Document 1 and Patent Document 2 are specifically peeled off at the processed portion due to, for example, retort treatment, so that the type and amount of printing ink that can be used and the amount of printing ink that can be used can be used. The shape and processing width are narrow, and there are problems in terms of print design and degree of freedom in processability.

Japanese Unexamined Patent Publication No. 2013-199539

Japanese Unexamined Patent Publication No. 2013-237735

The adhesive of the present invention can provide an adhesive for a film-laminated metal can, which is excellent in printability and adhesiveness of a processed portion, and is also excellent in blocking resistance and storage stability.

As a result of diligent research to solve the above problems, the present inventors have conducted a hydroxyl group-containing polyester resin (A) containing a hydroxyl group-containing polyester resin (A1) in a specific number average molecular weight range, and a triazine ring contained in an amino resin. Alternatively, an adhesive containing an alkyl etherified amino resin (B) having one or more butyl ether groups and a polyisocyanate compound (C) containing a blocked polyisocyanate compound (C1) in a specific composition ratio per urea skeleton. According to this, it was found that the above problems could be solved, and the present invention was completed.

That is, the present invention relates to the following contents.

1. 1. A hydroxyl group-containing polyester resin (A) containing a hydroxyl group-containing polyester resin (A1) having a number average molecular weight of 1500 to 35,000, an alkyl having one or more butyl ether groups per triazine ring or urea skeleton contained in the amino resin. It contains a polyisocyanate compound (C) containing an etherified amino resin (B) and a blocked polyisocyanate compound (C1), and has a component (A1) and a component (B) with respect to the total solid content of the hydroxyl group-containing polyester resin (A). ) And the solid content of the component (C) are 50% by mass or more of the hydroxyl group-containing polyester resin (A1), 1 to 20% by mass of the amino resin (B), and 2 to 30% by mass of the polyisocyanate compound (C). A film-laminated adhesive for metal cans that features.

2. Item 2. The adhesive for a film-laminated metal can according to Item 1, wherein the solid content of the blocked polyisocyanate compound (C1) is 5 to 95% by mass with respect to the total solid content of the polyisocyanate compound (C).

3. 3. The adhesive for a film-laminated metal can according to Item 1 or 2 above, wherein the polyisocyanate compound is an isocyanurate form of hexamethylene diisocyanate.

4. The adhesive for a film-laminated metal can according to any one of Items 1 to 3 above, wherein the blocking agent for the blocked polyisocyanate compound (C1) is a pyrazole compound.

5. Further, an adhesive for a film-laminated metal can containing an acrylic resin (D) having a glass transition temperature of 50 ° C. or higher, wherein the acrylic resin (D) is an isobornyl acrylate as a constituent monomer of the resin. The film according to any one of the above items 1 to 4, wherein at least one of isobornyl methacrylate (d1) is contained in an amount of 20% by mass or more based on the total amount of the constituent monomers of the resin. Adhesive for laminated metal cans.

6. A method for producing a film-laminated metal can, which forms an adhesive layer with an adhesive for the film-laminated metal can according to any one of the above items 1 to 5 on the outer surface side of the metal can.

A hydroxyl group-containing polyester resin (A) containing a hydroxyl group-containing polyester resin (A1) having a specific number average molecular weight, a triazine ring contained in the amino resin, or an alkyl etherification having one or more butyl ether groups per urea skeleton. According to the adhesive for film-laminated metal cans of the present invention, which contains a polyisocyanate compound (C) containing an amino resin (B) and a blocked polyisocyanate compound (C1) in a specific composition ratio, printability and processability. It is possible to provide a film-laminated metal can which is excellent in blocking resistance and laminating suitability.

A model diagram of a film structure using an adhesive for a film-laminated metal can of the present invention is shown.

The adhesive for a film-laminated metal can of the present invention contains a hydroxyl group-containing polyester resin (A1) having a number average molecular weight of 1500 to 35,000, a hydroxyl group-containing polyester resin (A), and a triazine ring or urea skeleton contained in the amino resin. Each contains an alkyl etherified amino resin (B) having one or more butyl ether groups and a polyisocyanate compound (C) containing a blocked polyisocyanate compound (C1).

The adhesive for a film-laminated metal can of the present invention (hereinafter, may be simply referred to as "adhesive") will be described in detail below.

[Adhesive for film-laminated metal cans]
Hydroxy group-containing polyester resin (A)
The hydroxyl group-containing polyester resin (A) can be produced by a known method by an esterification reaction or a transesterification reaction of an acid component (a1) and an alcohol component (a2).

Acid component (a1)
As the acid component (a1), a compound usually used as an acid component in the production of a polyester resin can be used, for example, aromatic polybasic acid, aromatic monocarboxylic acid, alicyclic polybasic acid, fat. Monobasic acids such as group polybasic acids and aliphatic monocarboxylic acids; and lower alkyl esterified products of these acids can be used.

The aromatic polybasic acid is generally an aromatic compound having two or more carboxyl groups in one molecule, an acid anhydride of the aromatic compound, and an esterified product of the aromatic compound, for example, phthalic acid. , Isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, trimellitic acid, pyromellitic acid and other aromatic polyvalent carboxylic acids; be able to. Aromatic polybasic acids can be used alone or in combination of two or more.

Examples of the aromatic monocarboxylic acid include benzoic acid, methyl benzoic acid, ethyl benzoic acid, butyl benzoic acid and the like.

The alicyclic polybasic acid is generally a compound having one or more alicyclic structures (mainly 4- to 6-membered rings) and two or more carboxyl groups in one molecule, an acid anhydride of the compound, and the said compound. It is an esterified compound. Examples of the alicyclic polybasic acid include 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, and 3-methyl. An alicyclic polyvalent carboxylic acid such as -1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,3,5-cyclohexanetricarboxylic acid; Anhydrous of these alicyclic polyvalent carboxylic acids; lower alkyl esterified products of these alicyclic polyvalent carboxylic acids and the like can be mentioned. The alicyclic polybasic acid can be used alone or in combination of two or more.

Examples of the alicyclic polybasic acid include 1,2-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid anhydride, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and 4-cyclohexene-. 1,2-Dicarboxylic acid and 4-cyclohexane-1,2-dicarboxylic acid anhydride can be preferably used. Of the above, 1,2-cyclohexanedicarboxylic acid and 1,2-cyclohexanedicarboxylic acid anhydride can be particularly preferably used from the viewpoint of hydrolysis resistance.

The aliphatic polybasic acid is generally an aliphatic compound having two or more carboxyl groups in one molecule, an acid anhydride of the aliphatic compound, and is, for example, succinic acid, glutaric acid, adipic acid, and pimerin. Aliphatic polyvalent carboxylic acids such as acids, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassic acid, octadecanedioic acid, citric acid; anhydrides of these aliphatic polyvalent carboxylic acids; etc. Can be mentioned. The aliphatic polybasic acid can be used alone or in combination of two or more.

As the aliphatic polybasic acid, it is preferable to use a dicarboxylic acid having an alkyl chain having 4 to 18 carbon atoms. Examples of the dicarboxylic acid having an alkyl chain having 4 to 18 carbon atoms include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassic acid, octadecanedioic acid and the like. Among them, dodecanedioic acid and octadecanedioic acid can be preferably used.

Examples of the aliphatic monocarboxylic acid include caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, elaidic acid, brassic acid, linoleic acid, linolenic acid, and logonic acid. be able to.

Alcohol component (a2)
As the alcohol component (a2), a polyhydric alcohol having two or more hydroxyl groups in one molecule, which is usually used as an alcohol component in the production of a polyester resin, can be preferably used. Examples of the polyhydric alcohol include aromatic diols, alicyclic diols, and aliphatic diols.

The aromatic diol is generally an aromatic compound having two hydroxyl groups in one molecule. Examples of the aromatic diol include ester diols such as bis (hydroxyethyl) terephthalate; and alkylene oxide adducts of bisphenol A, which can be used alone or in combination of two or more. it can.

The alicyclic diol is generally a compound having one or more alicyclic structures (mainly 4- to 6-membered rings) and two hydroxyl groups in one molecule. Examples of the alicyclic diol include dihydric alcohols such as 1,4-cyclohexanedimethanol, tricyclodecanedimethanol, hydrogenated bisphenol A, and hydrogenated bisphenol F; these dihydric alcohols include ε-caprolactone and the like. Examples thereof include polylactone diols to which lactones are added, and these can be used alone or in combination of two or more.

The aliphatic diol is generally an aliphatic compound having two hydroxyl groups in one molecule. Examples of the aliphatic diol include ethylene glycol, propylene glycol, diethylene glycol, trimethylene glycol, tetraethylene glycol, triethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, and 2,3. -Butanediol, 1,2-butanediol, 3-methyl-1,2-butanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-pentanediol, 1,5-pentanediol , 1,4-Pentanediol, 2,4-Pentanediol, 2,3-Dimethyltrimethylene glycol, Tetramethylene glycol, 3-Methyl-1,5-Pentanediol, 2,2,4-trimethyl-1,3 -Pentandiol, 1,6-hexanediol, 1,5-hexanediol, 1,4-hexanediol, 2,5-hexanediol, 1,9-nonanediol, 1,10-decanediol, 1,12- Examples of polyether diols such as dodecanediol, neopentyl glycol, polyethylene glycol, polypropylene glycol, and polybutylene glycol can be mentioned, and these can be used alone or in combination of two or more.

Examples of the polyhydric alcohol other than the aromatic diol, the alicyclic diol and the aliphatic diol include glycerin, trimethylolethane, trimethylolpropane, diglycerin, triglycerin, 1,2,6-hexanetriol and penta. Trihydric or higher alcohols such as erythritol, dipentaerythritol, tris (2-hydroxyethyl) isocyanurate, sorbitol, and mannit; polylactone polyols obtained by adding lactones such as ε-caprolactone to these trihydric or higher alcohols. The kind etc. can be mentioned. Of these, trimethylolpropane, triglycerin, and pentaerythritol are particularly preferable.

If necessary, monoalcohols such as methanol, ethanol, propyl alcohol, butyl alcohol, stearyl alcohol, and 2-phenoxyethanol; glycidyl esters of propylene oxide, butylene oxide, and synthetic highly branched saturated fatty acids (trade name "Cadura E10" HEXION). An alcohol compound obtained by reacting an acid with a monoepoxy compound such as (manufactured by Specialty Chemicals) can also be used.

The production of the hydroxyl group-containing polyester resin (A) used for the adhesive of the present invention is not particularly limited, and can be carried out according to a usual method. For example, it can be produced by reacting the acid component (a1) and the alcohol component (a2) in a nitrogen stream at 150 to 250 ° C. for 5 to 10 hours to carry out an esterification reaction or a transesterification reaction. In the above esterification reaction or transesterification reaction, the acid component (a1) and the alcohol component (a2) may be added at once or may be added in several batches.

Further, after first synthesizing the carboxyl group-containing polyester resin, a part of the carboxyl groups in the carboxyl group-containing polyester resin may be esterified using the alcohol component (a2). Further, the hydroxyl group-containing polyester resin may be first synthesized and then reacted with an acid anhydride to half-esterify the hydroxyl group-containing polyester resin.
During the esterification or transesterification reaction, a catalyst can be used to accelerate the reaction. As the catalyst, known catalysts such as dibutyltin oxide, antimony trioxide, zinc acetate, manganese acetate, cobalt acetate, calcium acetate, lead acetate, tetrabutyl titanate, and tetraisopropyl titanate can be used.

Further, the hydroxyl group-containing polyester resin (A) can be modified with fatty acids, fats and oils, polyisocyanate compounds, monoepoxy compounds and the like during the preparation of the resin (A), after the esterification reaction or the transesterification reaction. ..

Examples of the fatty acids include coconut oil fatty acid, cotton seed oil fatty acid, hemp seed oil fatty acid, rice bran oil fatty acid, fish oil fatty acid, tall oil fatty acid, soybean oil fatty acid, flaxseed oil fatty acid, tung oil fatty acid, rapeseed oil fatty acid, castor oil fatty acid, and dehydration. Fatty acids such as castor oil fatty acid and safflower oil fatty acid; and the like can be mentioned.

Examples of fats and oils include palm oil, cottonseed oil, hemp seed oil, rice bran oil, fish oil, tall oil, soybean oil, flaxseed oil, tung oil, rapeseed oil, castor oil, dehydrated castor oil, safflower oil and the like. it can.

Examples of the polyisocyanate compound include aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexane diisocyanate; hydrogenated xylylene diisocyanate, isophorone diisocyanate, methylcyclohexane-2,4-diisocyanate, and methylcyclohexane-2,6-diisocyanate. , 4,4'-Methylenebis (cyclohexylisocyanate), 1,3- (isocyanatomethyl) cyclohexane and other alicyclic diisocyanates; aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate; lysine triisocyanate Organic polyisocyanates such as trivalent or higher valent polyisocyanates themselves, or additions of each of these organic polyisocyanates to polyhydric alcohols, low molecular weight polyester resins, water, etc., or cyclization of each of the above organic diisocyanates. Polymers (eg, isocyanates), billet-type adducts and the like can be mentioned. These can be used alone or in combination of two or more.

The hydroxyl group-containing polyester resin (A) has a number average molecular weight of 5,000 to 35,000, preferably 8,000 to 32,000, and more preferably 1,000 to 30,000 from the viewpoint of curability, processability, and the like.

The hydroxyl group-containing polyester resin (A) has a glass transition temperature (Tg) of preferably 20 to 100 ° C, more preferably 25 to 60 ° C, from the viewpoint of processability and the like.

In the present specification, the "average molecular weight" of the resin is a value calculated from a chromatogram measured by a gel permeation chromatograph (manufactured by Tosoh Corporation, "HLC8120GPC") based on the molecular weight of standard polystyrene. Four columns, "TSKgel G-4000HXL", "TSKgel G-3000HXL", "TSKgel G-2500HXL", and "TSKgel G-2000HXL" (all manufactured by Tosoh Corporation, trade name) are used and moved. Phase: tetrahydrofuran, measurement temperature: 40 ° C., flow velocity: 1 cc / min, detector; RI conditions (* 1).

Further, in the present specification, the glass transition temperature (Tg) of the resin is based on differential thermal analysis (DSC) (* 2).

The hydroxyl group-containing polyester resin (A) has a hydroxyl value of 1 to 40 mgKOH / g, preferably 3 to 30 mgKOH / g, and more preferably 5 to 20 mgKOH / g from the viewpoint of curability and processability.

The acid value of the hydroxyl group-containing polyester resin (A) is preferably in the range of 20 mgKOH / g or less, preferably 1 to 15 mgKOH / g, and more preferably 3 to 10 mgKOH / g from the viewpoint of processability and water resistance. Is preferable.

From the viewpoint of water resistance, the hydroxyl group-containing polyester resin (A) contains 50% by mass or more, preferably 60% by mass or more of the hydroxyl group-containing polyester resin (A1) having a number average molecular weight of 1500 to 35000, preferably 18000 to 32000. It contains.

The glass transition temperature (Tg) of the hydroxyl group-containing polyester resin (A1) is preferably 30 ° C. or higher, more preferably 35 ° C. or higher, from the viewpoint of blocking resistance.

Amino resin (B)
The amino resin (B) is mainly used as a curing agent for the hydroxyl group-containing polyester resin (A).

By further containing the amino resin (B) as a curing agent in the conventional polyisocyanate compound, the curability of both the adhesive layer and the printing ink layer and the curability of both the adhesive layer and the printing ink layer, which vary depending on the composition of the adhesive layer and the printing ink layer, and It is possible to improve the interphase adhesion between the adhesive layer and the printing ink layer.

The amino resin (B) of the adhesive of the present invention is an alkyl etherified amino resin having one or more butyl ether groups per triazine ring or urea skeleton contained in the amino resin. Each triazine ring or urea skeleton contained in the amino resin contains an average of one or more butyl ether groups.

The amino resin (B) preferably has a weight average molecular weight of 400 to 6,000, more preferably 500 to 4,000, and even more preferably 600 to 3,000.

The amino resin (B) can be synthesized by reacting an amino compound, an aldehyde compound and an alcohol by a conventional method.

A partially methylolated amino resin or a fully methylolated amino resin obtained by reacting an amino compound with an aldehyde compound can also be synthesized by partially or completely alkyl etherifying with an alcohol.

Examples of the amino compound include melamine, urea, benzoguanamine, acetoguanamine, steroguanamine, spiroguanamine, dicyandiamide and the like.
Examples of the aldehyde compound include formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde and the like.

Examples of alcohols include methyl alcohol, ethyl alcohol, n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, i-butyl alcohol, t-butyl alcohol, 2-ethyl-1-butanol, and 2-ethyl-1. -Hexanol and the like can be mentioned.

The amino resin (B) can be produced by adjusting and synthesizing one triazine ring or urea skeleton contained in the amino resin so as to have one or more butyl ether groups. Examples of the alcohol used to have a butyl ether group include n-butyl alcohol, i-butyl alcohol, and t-butyl alcohol.

As the amino resin (B), a melamine resin can be preferably used. A butyl etherified melamine resin and a methyl-butyl mixed etherified melamine resin can be preferably used.

Examples of commercially available melamine resins include butyl etherified melamine resins (Uban 20SE-60 and Uban 225 manufactured by Mitsui Chemicals, Super Beccamin G840 and Super Beccamin G821 manufactured by Dainippon Ink and Chemicals), and methyl-butyl mixture. Examples thereof include etherified melamine resins (Simel 235, Cymel 202, Cymel 238, Cymel 254, Cymel 272, etc. manufactured by Ornex) and the like.

As a curing catalyst for the amino resin (B), if necessary, a sulfonic acid such as paratoluene sulfonic acid, dodecylbenzene sulfonic acid, dinonylnaphthalene sulfonic acid; a neutralized salt of the sulfonic acid and an amine; a phosphoric acid ester compound. A neutralized salt of amine and amine can be used.

Polyisocyanate compound (C)
The polyisocyanate compound (C) is mainly used as a curing agent for the above-mentioned hydroxyl group-containing polyester resin (A). Examples of the polyisocyanate compound include aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; cyclic aliphatic diisocyanates such as hydrogenated xylylene diisocyanate and isophorone diisocyanate; tolylene diisocyanate and 4,4'-diphenylmethane diisocyanate. Aromatic diisocyanate; triphenylmethane-4,4', 4 "-triisocyanate, 1,3,5-triisocyanatobenzene, 2,4,6-triisocyanatotoluene, 4,4'-dimethyldiphenylmethane-2 , 2', 5,5'-Tetraisocyanate and other organic polyisocyanates such as polyisocyanate compounds having three or more isocyanate groups, or each of these organic polyisocyanates and polyhydric alcohols, low molecular weight polyester resins Alternatively, an adduct with water or the like, a cyclized polymer of each of the above organic polyisocyanates, an isocyanate / biuret, or the like can be mentioned. Among these, isocyanurate, which is a cyclized polymer of hexamethylene diisocyanate. The body can be suitably used from the viewpoint of reactivity and reaction rate.

The polyisocyanate compound of the adhesive of the present invention contains a block polyisocyanate compound (C1) as an essential component from the viewpoint of making it a one-component type for economy and ease of handling.

The blocked polyisocyanate compound is obtained by blocking the free isocyanate group of the polyisocyanate compound with a blocking agent. Examples of the blocking agent include phenol-based agents such as phenol, cresol and xylenol; lactam-based agents such as ε-caprolactam, δ-valerolactam and γ-butyrolactam; methanol, ethanol, n-, i- or t-butyl alcohol and ethylene. Alcohols such as glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, and benzyl alcohol; Oxime-based; active methylene-based such as dimethyl malonate, diethyl malonate, ethyl acetoacetate, acetylacetone; pyrazole-based such as 3,5-dimethylpyrazole; and other blocking agents can be used. The free isocyanate group of the polyisocyanate compound can be easily blocked by mixing the polyisocyanate compound with the blocking agent.

As the blocked polyisocyanate compound (C1), a blocked polyisocyanate compound in which the blocking agent is a pyrazole compound can be preferably used from the viewpoint of the reaction rate.

In the adhesive of the present invention, particularly from the viewpoint of reactivity, a polyisocyanate compound (C2) other than the blocked polyisocyanate compound (C1) and the blocked polyisocyanate compound (C1) (that is, the isocyanate group is not usually blocked). Polyisocyanate compound) is preferably used in combination. In this case, from the viewpoint of pot life, it may be a two-component type instead of a one-component type.

When a polyisocyanate compound (C2) other than the blocked polyisocyanate compound (C1) and the blocked polyisocyanate compound (C1) is used in combination, the solid content of the blocked polyisocyanate compound (C1) is relative to the total solid content of the polyisocyanate compound (C). The content is 5 to 95% by mass, particularly 25 to 90% by mass, and more particularly 45 to 85% by mass, and the solid content of the polyisocyanate compound (C2) other than the blocked polyisocyanate compound (C1) is It is preferably 5 to 95% by mass, particularly preferably 10 to 75% by mass, and more preferably 15 to 55% by mass.

A curing catalyst can also be used to improve the curability of the polyisocyanate compound (C). Examples of the curing catalyst include tin octylate, dibutyltin di (2-ethylhexanoate), dioctyltin di (2-ethylhexanoate), dibutyltin dilaurate, dibutyltin oxide, dioctyltin oxide, and 2-ethyl. An organic metal catalyst such as lead hexanoate can be used.

In the adhesive of the present invention, the amino resin (B) is 1 to 20% by mass, particularly 3 to 15% by mass, and more particularly 5 to 10% by mass, based on the total solid content of the hydroxyl group-containing polyester resin (A). It is preferable that the content is within the range of 1 from the viewpoint of curability.

Further, the polyisocyanate compound (C) is 2 to 30% by mass, particularly 4 to 22% by mass, and more particularly 7 to 15% by mass with respect to the total solid content of the hydroxyl group-containing polyester resin (A). It is preferable from the viewpoint of curability and processing adhesion.

In the adhesive of the present invention, the amino resin (B) is 1 to 99% by mass, more particularly 5 to 95% by mass, based on the total solid content of the amino resin (B) and the polyisocyanate compound (C). The isocyanate compound (C) is preferably 1 to 99% by mass, more preferably 5 to 95% by mass.

Acrylic resin (D)
In particular, from the viewpoint of improving blocking resistance and the like, the adhesive of the present invention has a total amount of at least one of isobornyl acrylate and isobornyl methacrylate (d1) of 20 mass by mass with respect to the total amount of the constituent monomers. % Or more, and the acrylic resin (D) having a glass transition temperature of 50 ° C. or more can be further preferably contained.

The acrylic resin (D) is derived from, for example, at least one of isobornyl acrylate and isobornyl methacrylate (d1), a hydroxyl group-containing polymerizable unsaturated monomer (d2) and another polymerizable unsaturated monomer (d3). Can be synthesized by using the above-mentioned monomer component as a constituent component.

Examples of the hydroxyl group-containing polymerizable unsaturated monomer (d2) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 2,3-dihydroxybutyl ( Monoesteride of polyhydric alcohol such as meta) acrylate, 4-hydroxybutyl (meth) acrylate and polyethylene glycol mono (meth) acrylate and acrylic acid or methacrylic acid; monoester of the above polyhydric alcohol and acrylic acid or methacrylic acid. Compounds obtained by ring-opening polymerization of ε-caprolactone on the esterified product, for example, “Placel FA-1”, “Pluxel FA-2”, “Pluxel FA-3”, “Pluxel FA-4”, “Pluxel FA-5”, "Plaxel FM-1", "Plaxel FM-2", "Plaxel FM-3", "Plaxel FM-4", "Plaxel FM-5" (all of which are manufactured by Daicel Chemical Co., Ltd., trade names), etc. Can be mentioned. These can be used alone or in combination of two or more.

Other polymerizable unsaturated monomers (hereinafter, may be abbreviated as "other monomers (d3)") can be copolymerized with the above-mentioned components (d1) and (d2), and isobornyl acrylate and iso. It is a polymerizable unsaturated monomer other than at least one of the Bornyl methacrylates (d1) and the hydroxyl group-containing polymerizable unsaturated monomer (d2).

Examples of the other monomer (d3) include styrene, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) acrylate. , Tert-butyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, etc. Alkyl (meth) acrylate; carboxyl group-containing polymerizable unsaturated monomer such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride; glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate and the like. Epoxy group-containing polymerizable unsaturated monomer; aminoalkyl (meth) such as N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate. Acrylate; acrylamide, metaacrylamide, N, N-dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N-methylolacrylamide, N-methylol (Meta) acrylamide such as acrylamide methyl ether and N-methylol acrylamide butyl ether or derivatives thereof; examples thereof include acrylonitrile, methacrylonitrile, vinyl acetate, beovamonomer (manufactured by Shell Chemical Co., Ltd.), vinyl toluene, α-methylstyrene and the like. These compounds can be used alone or in combination of two or more. In addition, "(meth) acrylate" means acrylate or methacrylate, and "(meth) acrylamide" means acrylamide or metaacrylamide.

As for the blending ratio of the monomers constituting the acrylic resin (D), at least one of isobornyl acrylate and isobornyl methacrylate (d1) is 20% by mass or more, particularly 20 to 20 to the total amount of the constituent monomers. It is preferably in the range of 60% by mass, more particularly 30 to 50% by mass, from the viewpoint of blocking resistance, and the total amount of the hydroxyl group-containing polymerizable unsaturated monomer (d2) and other monomers (d3) is 80% by mass. % Or less, preferably in the range of 40 to 80% by mass, more preferably in the range of 50 to 70% by mass.

The polymerization method for polymerizing the above-mentioned monomer components to obtain the acrylic resin (D) is not particularly limited, and a polymerization method known per se, for example, a bulk polymerization method, a solution polymerization method, in the presence of a radical polymerization initiator. It can be synthesized by a bulk-suspension two-stage polymerization method or the like in which suspension polymerization is carried out after bulk polymerization, and among them, the solution polymerization method can be preferably used.

Examples of the radical polymerization initiator include ketone peroxides such as cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, and methylcyclohexanone peroxide; 1,1-bis (tert-butylperoxy) -3. , 3,5-trimethylcyclohexane, 1,1-bis (tert-butylperoxy) cyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, 2,2-bis (4,54-) Ditert-butylperoxycyclohexyl) propane, 2,2-bis (4,5-ditert-amylperoxycyclohexyl) propane, 2,2-bis (4,5-ditert-hexylperoxycyclohexyl) propane, Peroxyketals such as 2,2-bis (4,5-ditert-octylperoxycyclohexyl) propane, 2,2-bis (4,5-dicumylperoxycyclohexyl) propane; cumenehydroperoxide, 2 , 5-Dimethylhexane-2,5-Dihydroperoxide and other hydroperoxides; 1,3-bis (tert-butylperoxy-m-isopropyl) benzene, 2,5-dimethyl-2,5-di Dialkyl peroxides such as (tert-butylperoxy) hexane, diisopropylbenzene peroxide, tert-butylcumyl peroxide; decanoyyl peroxide, lauroyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, etc. Diacyl peroxides; peroxycarbonates such as bis (tert-butylcyclohexyl) peroxydicarbonate; pers such as tert-butylperoxybenzoate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane. Examples include organic peroxide-based polymerization initiators such as oxyesters and azo-based polymerization initiators such as 2,2'-azobis isobutylonitrile and 1,1-azobis (cyclohexane-1-carbonitrile). it can.

As a polymerization method by the solution polymerization method, specifically, for example, a mixture of the monomers is dissolved or dispersed in an organic solvent, and in the presence of the radical polymerization initiator, the temperature is usually about 80 ° C. to 200 ° C. A method of heating while stirring can be mentioned. The reaction time is usually about 1 to 24 hours.

Examples of the organic solvent include hydrocarbon solvents such as heptane, toluene, xylene, octane, and mineral spirit; ester solvents such as ethyl acetate, n-butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether acetate, and diethylene glycol monobutyl ether acetate; Ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone; alcohol solvents such as methanol, ethanol, isopropanol, n-butanol, sec-butanol, isobutanol; n-butyl ether, dioxane, ethylene glycol monomethyl ether, ethylene Ether-based solvents such as glycol monoethyl ether; aromatic petroleum-based solvents such as Swazole 310, Swazole 1000, Swazole 1500 (all manufactured by Cosmo Petroleum Co., Ltd.), SHELLSOL A (Shellzol A, manufactured by Shell Chemical Co., Ltd.) and the like. be able to. These organic solvents can be used alone or in combination of two or more.

The glass transition temperature of the acrylic resin (D) (see Note 2 above) should be in the range of 30 ° C. or higher, particularly 30 to 80 ° C., and particularly 35 to 70 ° C. from the viewpoint of blocking resistance and appearance of the film surface. Is suitable.

The acrylic resin (D) preferably has a weight average molecular weight (see Note 1 above) in the range of 2000 to 20000, particularly 5000 to 15000, from the viewpoint of the appearance of the film surface.
The hydroxyl value of the acrylic resin (D) is preferably in the range of 40 to 140 mgKOH / g, particularly 60 to 130 mgKOH / g, and more preferably 80 to 120 mgKOH / g from the viewpoint of lamination strength.

When the adhesive of the present invention contains the acrylic resin (D), the amount of the acrylic resin (D) is 0.1 to 10% by mass, particularly 0.5, based on the total solid content of the hydroxyl group-containing polyester resin (A). It is preferably in the range of about 7% by mass, more particularly 0.7 to 5% by mass, from the viewpoint of blocking resistance.

In addition, the adhesive of the present invention may contain a coloring pigment, an additive (blocking inhibitor, lubricity imparting agent, defoaming agent, etc.), an organic solvent, etc., if necessary.
Examples of the coloring pigment include titanium dioxide, carbon black, iron oxide, quinacridone, perylene, phthalocyanine and the like.

Examples of the blocking inhibitor include extender pigments (for example, silica fine powder, barium sulfate, calcium carbonate, talc, mica, clay, etc.), organic fine particles (nylon fine particles, polyolefin fine particles, acrylic resin fine particles, silicone rubber fine particles, urethane resin fine particles, etc.). , Phenolic resin fine particles, polytetrafluorinated ethylene fine particles, etc.) and the like.

The lubricity-imparting agent imparts lubricity to the surface of the adhesive, in order to smoothly wind the laminated film coated with the adhesive into a coil shape, and on the surface of the adhesive layer when the coil is unwound. It can be contained for the purpose of preventing scratches and the like. Examples of the lubricity imparting agent include fatty acid ester wax; polyolefin wax such as polyethylene wax; animal wax such as lanolin and beeswax; plant wax such as carnauba wax and water wax; microcrystallin wax, silicon wax and fluorine. Waxes such as waxes can be mentioned.

Further, the adhesive of the present invention can be imparted with active energy ray curability by adding an oligomer having a polymerizable unsaturated double bond, if necessary. Examples of commercially available oligomers having a polymerizable unsaturated double bond include Aronix M-305 (manufactured by Toagosei Co., Ltd.), EICA (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), and Light Acrylate TMP-6EO-3A (manufactured by Kyoei Co., Ltd.). ) Etc. can be mentioned.

When the adhesive of the present invention is a one-component type, a hydroxyl group-containing polyester resin (A), an amino resin (B), and a polyisocyanate compound (C), and if necessary, an acrylic resin (D), It can be produced by adding a coloring pigment, an additive, an organic solvent and the like and mixing them sufficiently.

When the adhesive of the present invention is a two-component type, a hydroxyl group-containing polyester resin (A), an amino resin (B), a blocked polyisocyanate compound (C1), and, if necessary, an acrylic resin (D). ), Color pigments, additives, organic solvents, etc. are added and mixed sufficiently to use this as the main agent, and immediately before use, a polyisocyanate compound (C2) other than the blocked polyisocyanate compound (C1) is added to the main agent as a curing agent. It can be produced by adding and mixing as.

The adhesive of the present invention is described in Zahn Cup No. In 3, it can be applied in usually 14 to 24 seconds, preferably 15 to 20 seconds. The solid content concentration at the time of application of the adhesive was determined by Zahn Cup No. The viscosity of 3 for 10 to 22 seconds (measurement temperature 20 ° C.) is preferably 10% by mass or more.

Method for Producing Film Laminated Metal Can The production of a film-laminated metal can using the adhesive of the present invention can be carried out, for example, by the following steps 1 to 3.
Process 1. Apply adhesive to the polyester film.
Process 2. The polyester film is laminated on a metal plate.
Process 3. A metal plate on which a polyester film is laminated is molded into a film-laminated metal can.

Hereinafter, the process will be described in detail.

Process 1. Apply adhesive to the polyester film. :
The adhesive can be applied onto the polyester film by a known coating means such as a roll coater method, a die coater method, a gravure method, a gravure offset method, and a spray coating method. Further, the drying is usually carried out only by volatilizing the solvent in the coating liquid, and is usually carried out at a temperature of about 50 to 180 ° C. so as not to cause blocking even if the polyester film is wound into a coil. The coating amount of the adhesive, as a dry coating weight, preventing color unevenness, from the viewpoint of hiding, etc., 0.2 to 20 g / ^{m 2,} preferably be in the range of 0.5~16g / ^{m 2} .. As the polyester film, one in which 75 to 100% of the ester repeating units are composed of ethylene terephthalate units can be preferably used from the viewpoint of processability and adhesiveness.

Examples of the ester repeating unit other than the ethylene terephthalate unit include ethylene phthalate, ethylene isophthalate, and ethylene adipate. As the polyester film, in order to improve the adhesiveness with ink or an adhesive, a polyester film having a surface treatment such as a corona discharge treatment can be preferably used. The film thickness of the polyester film is not particularly limited, but is usually preferably about 5 to 30 μm.

The polyester film may have an ink layer. The ink layer can be formed by printing ink on a film by, for example, a gravure printing method, and if necessary, removing or curing the solvent by heating, irradiation with active energy rays, or the like.

The laminating film is produced by applying an adhesive on the above film (usually on the ink layer surface when the film has an ink layer) and drying to form an adhesive layer having no surface adhesiveness. Can be done. The film having the dried adhesive layer is usually wound into a coil and used for production in the next step.

Further, the adhesive of the present invention specifically applies, for example, to a polyester film (transparent, thickness 10.5 μm) ^{so as to be 9 g / 1 m 2,} and the light transmittance of the adhesive layer obtained is obtained. By adjusting the ratio to 29% or less, preferably 5 to 28%, and more preferably 10 to 28%, an adhesive layer having a good whiteness can be obtained. In the above, the light transmittance was measured according to JIS K7361-1 using a haze meter HM-150 (manufactured by Murakami Color Research Institute Co., Ltd., trade name).

Process 2. The polyester film is laminated on a metal plate. :
Next, the polyester film laminated metal plate can be obtained by uncoiling the polyester film obtained in step 1 and laminating it on the metal plate. Examples of the metal plate used for the above lamination include hot-rolled steel sheet, cold-rolled steel sheet, hot-dip galvanized steel sheet, electrogalvanized steel sheet, iron-zinc alloy-plated steel sheet, zinc-aluminum alloy-plated steel sheet, and nickel-zinc compound. Metal plate materials such as gold-plated steel plate, nickel-tin alloy-plated steel plate, tin, chrome-plated steel plate, aluminum-plated steel plate, turn-plated steel plate, nickel-plated steel plate, stainless steel, tin-free steel, aluminum plate, copper plate, titanium plate; Examples thereof include a chemical-treated metal plate obtained by subjecting a metal plate material to a chemical conversion treatment, for example, a phosphate treatment, a chromate treatment, a composite oxide film treatment, or the like. Further, the metal plate may be a processed metal plate obtained by molding a flat metal plate such as the metal plate material, a chemical conversion-treated metal plate or a primer-coated metal plate into, for example, a can body.

The condition for laminating the laminating film having the adhesive layer on the surface of the metal plate is that the laminating film does not deteriorate, the film and the metal plate are sufficiently adhered, and the film-laminated metal plate having a good appearance is obtained. As long as it can be obtained, it is not particularly limited.

As an example of laminating conditions, for example, the temperature of the metal plate at the time of thermocompression bonding is set to about 120 to 200 ° C. by a method using a heating roll or a method of preheating the metal plate, and the metal plate is formed in a short time (usually 2 seconds or less). Examples thereof include a method of thermocompression bonding with a laminating film for laminating. When a flat metal plate is used, a laminating film can be heat-laminated on one side or both sides of the flat metal plate.

Further, after the heat laminating, the adhesive layer can be further thermoset by heating at the time of baking the paint on the inner surface of the can, for example. The thermosetting is preferably performed under conditions that the thermosetting film does not deteriorate, for example, the maximum temperature of the metal plate is 180 to 230 ° C. and the baking time is 30 to 120 seconds.

Process 3. A metal plate on which a polyester film is laminated is molded into a film-laminated metal can. :
The film-laminated metal can can be manufactured by cutting the film-laminated metal plate and molding it. A film-laminated metal can can also be obtained by directly laminating the laminating film on a molded can. The film-laminated metal can can be used as, for example, a beverage can, a food can, a miscellaneous can, a 5-gallon can, or the like.

Hereinafter, the present invention will be described in more detail with reference to Production Examples, Examples and Comparative Examples. However, the present invention is not limited thereto. In each example, "part" and "%" are based on mass unless otherwise specified. The film thickness of the coating film is based on the cured coating film.

Production Example of Hydroxide-Containing Polyester Resin (A) Solution Production Example 1 Production of Polyester Resin A-1 Solution In a four-necked flask equipped with a heating device, agitator, thermometer, reflux condenser, and water separator, the following ""Monomer1" was charged. Next, according to a conventional method, the produced condensed water was distilled off using an aqueous separator to carry out an esterification reaction, and 0.12 parts of trimellitic anhydride was added to the product, and then toluene and methyl ethyl ketone were added. An appropriate amount was blended to obtain a polyester resin A-1 solution having a solid content of 40% by mass. The resin solid content of the obtained polyester resin A-1 solution had a hydroxyl value of 6 mgKOH / g, an acid value of 6 mgKOH / g, a glass transition temperature of 42 ° C., and a number average molecular weight of 18,000.

"Monomer 1"
Isophthalic acid 30.0 parts 1,3-cyclohexanedicarboxylic acid 60.0 parts Adipic acid 10.0 parts 1,4-Cyclohexanedimethanol 50.0 parts Ethylene glycol 10.0 parts 1,6-hexanediol 20.0 parts 2-Butyl-2-ethyl-1,3-propanediol 10.0 parts Trimethylol propane 10.0 parts Production Example 2-8 Production of polyester resin A-2 to A-8 solutions In Production Example 1, Table 1 shows. Except for the formulations shown, the same operation was carried out to obtain solutions A-2 to A-8 of each polyester resin having a solid content of 40% by mass.

The polyester resins corresponding to the hydroxyl group-containing polyester resin (A1) are the four polyester resins A-1, A-2, A-4, and A-6 in Table 1 above.

Production example of amino resin (B) solution Production example 9
Add 196 parts of paraformaldehyde (containing 92% formaldehyde), 126 parts of melamine, 224 parts of methanol, and 370 parts of n-butanol to a reactor equipped with a thermometer, a stirrer, a reflux condenser, and a solvent by-product recovery device, and stir. While doing so, a 10% aqueous solution of phosphoric acid was added to adjust the pH of the reaction solution to 5.0. It was melted by heating to the reflux temperature. Then, the reaction solution was heated to keep the temperature of the reaction solution at 70 ° C. and the reaction was continued for 4 hours, and then triethylamine was added to adjust the pH in the system to 7.0. A solution of amino resin (X) is obtained by removing excess methanol and n-butanol to the outside of the system so that the non-volatile content of the resin becomes 70% while keeping the temperature inside the system at 70 ° C. or lower under reduced pressure. It was. The content of n-butoxy groups in the obtained amino resin (X) determined by C13 NMR was about 1.3 per triazine ring. The amino resin (X) is an amino resin corresponding to the amino resin (B).

Production Example 10
Add 196 parts of paraformaldehyde (containing 92% formaldehyde), 126 parts of melamine, 224 parts of methanol, and 222 parts of n-butanol to a reactor equipped with a thermometer, a stirrer, a reflux condenser, and a solvent by-product recovery device, and stir. While doing so, a 10% aqueous solution of phosphoric acid was added to adjust the pH of the reaction solution to 5.0. It was melted by heating to the reflux temperature. Then, the reaction solution was heated to keep the temperature of the reaction solution at 70 ° C. and the reaction was continued for 4 hours, and then triethylamine was added to adjust the pH in the system to 7.0. A solution of amino resin (Y) is obtained by removing excess methanol and n-butanol to the outside of the system so that the non-volatile content of the resin becomes 70% while keeping the temperature inside the system at 70 ° C. or lower under reduced pressure. It was. The content of n-butoxy groups of the obtained amino resin (Y) determined by C13 NMR was about 0.8 per triazine ring. The amino resin (Y) is an amino resin that does not correspond to the amino resin (B).

Production example of acrylic resin (D) solution Production example 11
60 parts of xylene was placed in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a thermostat, and a dropping pump, and the temperature was raised to 125 ° C. with stirring. The dropping was carried out at a constant speed over 3 hours using a dropping pump. After completion of the dropping, the reaction was completed by aging at the same temperature for 2 hours to obtain an acrylic resin D solution having a resin solid content of 60% by mass. The resin solid content of the obtained acrylic resin D solution had a weight average molecular weight of about 9,000, a hydroxyl value of 78 mgKOH / g, and a glass transition temperature of 70 ° C.

"Monomer and Polymerization Initiator"
Isobornyl acrylate 35 parts 2-ethylhexyl methacrylate 15 parts 2-hydroxyethyl methacrylate 18 parts styrene 20 parts t-butyl methacrylate 12 parts t-butylperoxy 2-ethylhexanoate 6.5 parts
Production Example 1 Adhesive for Film Laminated Metal Cans Adhesive No. Production Example 1 100 parts (solid content) of the polyester resin A-1 solution having a solid content of 40% by mass and 140 parts of Typake CR-95 (Note 1) obtained in Production Example 1 were stirred and mixed. Next, 10 parts (solid content) of Cymel 235 (Note 5), 6 parts (solid content) of TRIXENE BI 7951 (Note 9), and 4 parts (solid content) of Sumijour N3300 (Note 12) were added and mixed by stirring. , Toluene and methyl ethyl ketone are blended in appropriate amounts to form an adhesive No. with a solid content of 45% by mass. I got 1.

Examples 2-27 Adhesive No. 2-No. 27 Production Example In the same manner as in Example 1 except that the composition is shown in Table 2 in Example 1, each adhesive No. 2-No. 27 was manufactured.

(Note 1) Typake CR-95: Product name, manufactured by Ishihara Sangyo Co., Ltd., rutile type titanium dioxide (Note 2) GX-40A: Product name, manufactured by Asahi Kasei Metals Co., Ltd., non-leafing aluminum (Note 3) Uban 20SE-60: Product Name, Mitsui Chemicals, butyl etherified melamine resin (Note 4) Cymel 202: Product name, Ornex, methylbutyl mixed etherified melamine resin (Note 5) Cymel 235: Product name, Ornex, methylbutyl mixed etherified melamine Resin (Note 6) Cymel VX805: Trade name, manufactured by Ornex, methyl isobutyl mixed etherified melamine resin (Note 7) Uban 10R: manufactured by Mitsui Chemicals, butyl etherified urea resin (Note 8) BX-4000: Sanwa Chemical Co., Ltd. Methylbutyl mixed etherified benzoguanamine resin (Note 3) to (Note 8) all amino resins contain one or more butyl ether groups per triazine ring or urea skeleton contained in the amino resin, and are amino. It is an amino resin corresponding to the resin (B).

(Note 9) TRIXENE BI 7951: Trade name, Hexamethylene diisocyanate dimethylpyrazole block (Note 10) TRIXENE BI 7960: Trade name, Baxenden, Isophorone diisocyanate dimethylpyrazole block (Note 11) K6000 : Product name: Active methylene compound block of hexamethylene diisocyanate manufactured by Asahi Kasei Co., Ltd. (Note 12) Sumijuru N3300: Product name, manufactured by Sumika Bayer Urethane Co., Ltd., Nurate-modified hexamethylene diisocyanate (Note 13) Takenate D-165N: Product name, Mitsui Chemicals, Bullet-modified hexamethylene diisocyanate (Note 14) Sumijour HT: Product name, Sumika Cobestrourethane, Adduct-modified hexamethylene diisocyanate (Note 15) Takenate D-140N: Product name, Mitsui Adduct-modified isophorone diisocyanate manufactured by Kagaku Co., Ltd. Comparative Examples 1 to 13
In Example 1, each adhesive No. was obtained in the same manner as in Example 1 except that the composition was shown in Table 3. 28-No. 40 was manufactured.

(Note 16) Cymel 303: Product name, manufactured by Ornex, methyl etherified melamine resin (Note 17) Cymel 325: Product name, manufactured by Ornex, methyl etherified melamine resin (Note 18) Cymel 327: Product name, manufactured by Ornex , Methyl etherified melamine resin All of the amino resins (Note 16) to (Note 18) do not contain a butyl ether group and do not correspond to the amino resin (B).

Each adhesive No. The viscosities of 1 to 40 were tested and evaluated by the following methods.

(Note 19) Viscosity:
The viscosity of each adhesive was determined by Zahn Cup No. Evaluation was performed at 3 (measurement temperature 20 ° C.).
⊚: Solid content 48% is 16 seconds or less ○: Solid content 45% is 16 seconds or less Δ: Solid content 40% is less than 16 seconds ×: Solid content 40% is 16 seconds or more Each adhesion Agent No. For 1 to 40, each test plate was prepared by the following method and subjected to each performance test.

Preparation of PET Laminated Metal Plate (Single Film) For each of the adhesives obtained in the above Examples and Comparative Examples, a "PET laminated metal plate (single film)" was prepared by the following procedure.

One side of a PET film (thickness 10.5 μm, width 200 mm) is coated with an adhesive for each film-laminated metal can so that the dry coating weight is 9 g / m ^2, and the organic solvent is evaporated and dried for lamination. I got a film for. After curing each of the obtained laminated films at 25 ° C. for 72 hours or more, the coating film layer surface was superposed on a tin-free steel plate preheated to 160 ° C., and a heat roll at 160 ° C. was used to increase the pressure at 30 kg / cm ² and the speed at 50 m /. Each "PET laminated metal plate (single film)" was obtained by heating and laminating in minutes.

PET laminated metal plate except that the creation PET film (ink film stack) and a PET film having an ink layer, PET laminated metal sheet (single layer) creation and in the same manner as the "PET laminated metal sheet (ink laminated film) I got.

Further, a mixture of the hydroxyl group-containing polyester resin (A), the amino resin (B), and the polyisocyanate compound (C1) is stored at 40 ° C. for 1 month, and the polyisocyanate compound (C2) is added and mixed immediately before use. Each of the obtained adhesives (after storage) was also prepared in the same procedure as above to obtain each "PET laminated metal plate (ink laminated film / after storage)".

Test method (Note 20) Adhesiveness (single film):
A test piece that had been hat-processed from the back side of the "PET laminated metal plate (single film)" using an Eriksen testing machine was retort-treated at 125 ° C. for 30 minutes, and the adhesive state of the PET film was evaluated according to the following criteria. ..
◎ indicates that the PET film does not peel off at a height of 12 mm ○ indicates that the PET film does not peel off at a height of 9 mm △ indicates that the PET film does not peel off at a height of 6 mm × indicates that the PET film does not peel off at a height of 6 mm (Note) 21) Adhesiveness (ink laminate film):
A test piece that has been hated from the back side of the "PET laminated metal plate (ink laminated film)" using an Eriksen testing machine is retorted at 125 ° C for 30 minutes, and the adhesive state of the PET film is evaluated according to the following criteria. did.
◎ indicates that the PET film does not peel off at a height of 12 mm ○ indicates that the PET film does not peel off at a height of 9 mm △ indicates that the PET film does not peel off at a height of 6 mm × indicates that the PET film does not peel off at a height of 6 mm (Note) 22) Blocking resistance:
The surface of the adhesive layer of the "PET laminated metal plate (single film)" is covered with another PET film, and ^{a pressure of 10 kg / cm 2} is applied to store the adhesive layer in a room at a temperature of 25 ° C. and a humidity of 60% RH for 3 days. did. This storage laminate film is cut into a width of 30 mm, and the peel strength (g / 30 mm) when the other PET film is peeled from the dry coating film surface at a tensile speed of 500 mm / min by 180 degrees is measured and evaluated according to the following criteria. did.
⊚: Peeling strength is less than 10 g / 30 mm
〇: Peeling strength is 10 g / 30 mm or more and less than 20 g / 30 mm Δ: Peeling strength is 20 g / 30 mm or more and less than 50 g / 30 mm ×: Peeling strength is 50 g / 30 mm or more (Note 23) Adhesiveness after storage (ink laminated film) ):
The test piece that was hat-processed from the back side of the "PET laminated metal plate (ink laminated film, after storage)" using an Eriksen testing machine was retorted at 125 ° C for 30 minutes, and the adhesion state of the PET film was as follows. Evaluated by criteria.
◎ indicates that the PET film does not peel off at a height of 12 mm ○ indicates that the PET film does not peel off at a height of 9 mm △ indicates that the PET film does not peel off at a height of 6 mm × indicates that the PET film does not peel off at a height of 6 mm

The adhesive of the present invention can provide an adhesive for a film-laminated metal can, which is excellent in printability and adhesiveness of a processed portion, and is also excellent in blocking resistance and storage stability.

1. 1. Object to be coated (metal can)
2. Adhesive layer with adhesive 3. Printing ink layer 4. the film

Claims (6)

A hydroxyl group-containing polyester resin (A) containing a hydroxyl group-containing polyester resin (A1) having a number average molecular weight of 1500 to 35,000, an alkyl having one or more butyl ether groups per triazine ring or urea skeleton contained in the amino resin. Containing a polyisocyanate compound (C) containing an etherified amino resin (B) and a blocked polyisocyanate compound (C1),
The solid content of the component (A1), the component (B) and the component (C) is 50% by mass or more of the hydroxyl group-containing polyester resin (A1) with respect to the total solid content of the hydroxyl group-containing polyester resin (A). B) An adhesive for a film-laminated metal can, characterized in that it is 1 to 20% by mass and the polyisocyanate compound (C) is 2 to 30% by mass. The adhesive for a film-laminated metal can according to claim 1, wherein the solid content of the blocked polyisocyanate compound (C1) is 5 to 95% by mass with respect to the total solid content of the polyisocyanate compound (C). The adhesive for a film-laminated metal can according to claim 1 or 2, wherein the polyisocyanate compound is an isocyanurate form of hexamethylene diisocyanate. The adhesive for a film-laminated metal can according to any one of claims 1 to 3, wherein the blocking agent of the blocked polyisocyanate compound (C1) is a pyrazole compound. Further, an adhesive for a film-laminated metal can containing an acrylic resin (D) having a glass transition temperature of 50 ° C. or higher, wherein the acrylic resin (D) is an isobornyl acrylate as a constituent monomer of the resin. The film according to any one of claims 1 to 4, wherein at least one of isobornyl methacrylate (d1) is contained in an amount of 20% by mass or more based on the total amount of the constituent monomers of the resin. Adhesive for laminated metal cans. The method for producing a film-laminated metal can, which forms an adhesive layer with an adhesive for the film-laminated metal can according to any one of claims 1 to 5 on the outer surface side of the metal can.

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