KR-102961724-B1 - SOLVENT-FREE TYPE ADHESIVE COMPOSITION AND LAMINATE

Abstract

The present invention provides a solvent-free adhesive composition in which the increase in viscosity after mixing is suppressed, workability is excellent, acid resistance is suitable, and deterioration over time is difficult, and a laminate using the composition. The solvent-free adhesive composition of the present invention comprises a resin (A) formed by copolymerizing a (meth)acrylic acid ester and maleic anhydride, a polyol (B) having a secondary hydroxyl group at a terminal, and an aromatic polyisocyanate (C). Preferably, the content of the resin (A) is 0.1 to 10 mass% with respect to the polyol (B).

Inventors

• 나츠우미 쥬메이
• 우치야마 유세이
• 마에다 사토시
• 카네코 치사토

Assignees

• 아티엔스 가부시키가이샤
• 도요 모톤 리미티드

Dates

Publication Date

20260508

Application Date

20200701

Priority Date

20191016

Claims (7)

1. A resin (A) formed by copolymerizing a (meth)acrylic acid ester and maleic anhydride, a polyol (B) having a secondary hydroxyl group at a terminal, and an aromatic polyisocyanate (C) are included, A polyol (B) having a secondary hydroxyl group at the terminal includes a polyester polyol obtained by reacting a dibasic acid, its dialkyl ester, or a mixture thereof with a polyhydric alcohol having a primary terminal hydroxyl group and a secondary terminal hydroxyl group. The content of the polyol (B) having a secondary hydroxyl group at the terminal is 50 to 100 mass% of the total polyol component 100 mass%, and The aromatic polyisocyanate compound (C) comprises a reaction product of the aromatic polyisocyanate compound and polypropylene glycol, and A solvent-free adhesive composition having a number average molecular weight of 200 to 3,000 of the above polypropylene glycol.
2. In paragraph 1, A solvent-free adhesive composition having a content of the resin (A) of 0.1 to 10 mass% relative to the polyol (B).
3. In paragraph 1 or 2, A solvent-free adhesive composition comprising a polyol (B) having a secondary hydroxyl group at the terminal end, which is a polyester polyol obtained by reacting propylene glycol with a dibasic acid or its dialkyl ester or a mixture thereof.
4. delete
5. In paragraph 1 or 2, A solvent-free adhesive composition having an acid value of 250 mgKOH/g or higher of the above resin (A).
6. In paragraph 1 or 2, In addition, a solvent-free adhesive composition containing 0.1 to 10 mass% of a silane coupling agent with respect to the polyol (B).
7. A laminate comprising an adhesive layer made of the solvent-free adhesive composition described in claim 1 or 2, laminated between at least two sheet-like substrates.

Description

Solvent-free type adhesive composition and laminate The present invention relates to a solvent-free adhesive composition having excellent adhesive properties, suitable for use when manufacturing a laminate for packaging food, medical products, cosmetics, etc., by laminating various plastic films and a metal-deposited film or metal foil. Furthermore, the present invention relates to a laminate suitable for use in packaging food, medical products, cosmetics, etc. Recently, composite films formed by multilayer lamination of metal foils, such as aluminum foil or metal-deposited films, and plastic films, such as polyethylene, polypropylene, vinyl chloride, polyester, and nylon, are being used as packaging materials for food, medical products, and cosmetics. It is known that adhesives used to bond plastic films with metal foils or metal-deposited films include polymer polyols obtained by reacting aromatic polycarboxylic acid anhydrides and organic isocyanate compounds. Conventionally, as a solvent-type laminate adhesive used for a laminate composite film containing a metal foil as described above, a two-component adhesive containing a polyol compound as a main component and a polyisocyanate compound as a curing agent is preferably used. In addition, for the purpose of imparting resistance to contents (e.g., acid resistance) to the metal foil, methods of introducing acid groups to the molecular ends of a polyol compound (e.g., Patent Document 1) and adding phosphoric acid, or phosphoric acid and a silane coupling agent, are known (e.g., Patent Documents 1 and 2). In addition, Patent Document 3 discloses a solvent-type adhesive composition that has excellent heat and water resistance and acid resistance, and suppresses the deterioration of adhesive properties over time by using a resin formed by copolymerizing (meth)acrylic acid ester and maleic anhydride. <Solvent-free adhesive composition> The solvent-free adhesive composition of the present invention comprises a resin (A) formed by copolymerizing a (meth)acrylic acid ester and maleic anhydride, a polyol (B) having a secondary hydroxyl group at the terminal end, and an aromatic polyisocyanate (C). Even when a solvent-free formulation is formed by combining a resin (A) formed by copolymerizing a (meth)acrylic acid ester and maleic anhydride, a polyol (B) having a secondary hydroxyl group at the terminal end, and an aromatic polyisocyanate (C), the increase in viscosity after compounding is suppressed, thereby extending the pot life and improving workability. The present invention is described in detail below. <Resin (A) formed by copolymerizing (meth)acrylic acid ester and maleic anhydride> The resin (A) formed by copolymerizing a (meth)acrylic acid ester and malein anhydride used in the present invention is not particularly limited and can be selected from conventionally known resins. One or more types of resin (A) may be used. Examples of (meth)acrylic acid ester monomers include methyl methacrylate, ethyl methacrylate, propyl methacrylate, propyl methacrylate, butyl methacrylate, propyl methacrylate, t-butyl methacrylate, pentyl methacrylate, decyl methacrylate, heptyl methacrylate, cyclohexyl octyl methacrylate, and phenyl methacrylate. Among these, methyl methacrylate is preferred from the perspective of copolymerization with maleic anhydride. As a method for synthesizing resin (A), radical copolymerization methods such as solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization can be used. The amounts of (meth)acrylic acid ester and maleic anhydride when copolymerizing resin (A) can be appropriately designed. With respect to the total amount of (meth)acrylic acid ester and maleic anhydride, the amount of (meth)acrylic acid ester is preferably 50 to 95 mass%, more preferably 50 to 70 mass%, and the amount of maleic anhydride is preferably 5 to 50 mass%, more preferably 30 to 50 mass%. If the amount of maleic anhydride is 5 mass% or more, it is desirable because the adhesive strength does not deteriorate during long-term storage, and if it is 50 mass% or less, it is desirable because the synthesis of the copolymer of (meth)acrylic acid ester and maleic anhydride is easy. The acid value of the resin (A) is preferably 250 mgKOH/g or higher, more preferably 300 mgKOH/g or higher, and particularly preferably 350 mgKOH/g or higher. An acid value of 250 mgKOH/g is desirable because the decrease in adhesive strength during long-term storage is small. The number average molecular weight (Mn) of the resin (A) is preferably 1,000 to 50,000, more preferably 10,000 to 12,000. It is preferable that Mn be 1,000 or higher so that the deterioration of adhesive strength during long-term storage is minimal, and that Mn be 50,000 or lower so that the compatibility of the adhesive composition is good and the coating appearance of the adhesive composition is excellent. The content of the resin (A) is preferably 0.1 to 10 mass%, more pre