TW202118847A - Pressure-sensitive adhesive composition and surface protective film - Google Patents

Abstract

An object of the present invention is to provide a pressure-sensitive adhesive composition which is capable of maintaining the transparency of a surface protective film even under high temperature and high humidity. The present invention uses a pressure-sensitive adhesive composition which comprises a urethane resin (A) and a curing agent (B), wherein the urethane resin (A) is a reaction product of a polyol (a1) and a polyisocyanate (a2), and the polyol (a1) contains a polymer polyol (a1-1) and a polyol having a carboxyl group (a1-2); and the curing agent (B) contains a curing agent having a functional group capable of reacting with a carboxyl group.

Description

Adhesive composition and surface protective film

The present invention relates to a pressure-sensitive adhesive composition and surface protective film.

The surface protection film is used for the purpose of preventing contamination and damage on the surface of various substrates. The aforementioned surface protection film is attached to an optical member or the like in the manufacturing process of a display device, for example, and is peeled from the optical member or the like at a stage where surface protection is not required.

As an adhesive used for such a surface protective film, an adhesive containing a urethane polymer having an ester bond, a fatty acid ester, and a curing agent is known (for example, refer to Patent Document 1). Furthermore, an adhesive containing a urethane resin having a hydroxyl group, a curing agent, and a diester or triester of an organic acid is known (for example, refer to Patent Documents 2 and 3). Furthermore, an adhesive containing a polyurethane having two or more hydroxyl groups, a crosslinking agent, a carbodiimide compound, and an organic solvent is known (for example, refer to Patent Document 4). Furthermore, it is known that an adhesive containing a polyurethane obtained by reacting a polyisocyanate, a polyol, a dioxycarboxylic acid, etc., and a polyisocyanate curing agent (for example, refer to Patent Document 5).

[Prior Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent No. 5861794

[Patent Document 2] Japanese Patent No. 5974311

[Patent Document 3] Japanese Patent No. 5974313

[Patent Document 4] Japanese Patent No. 6032388

[Patent Document 5] JP 2010-180290 A

However, when the adhesive described in Patent Documents 1 to 5 is used for the surface protection film, the surface protection film may become cloudy (white fog) when it is left under high temperature and high humidity. The present invention was made in view of the foregoing circumstances, and its object is to provide an adhesive composition capable of maintaining the transparency of a surface protective film even under high temperature and high humidity.

The adhesive composition of the present invention contains a urethane resin (A) and a hardener (B). The urethane resin (A) is a reaction product of a polyol (a1) and a polyisocyanate (a2). The polyol (a1) contains a polymer polyol (a1-1) and a polyol (a1-2) having a carboxyl group, and the curing agent (B) contains a curing agent having a functional group capable of reacting with the carboxyl group.

The adhesive composition of the present invention is based on the obtained surface protective film, and can maintain transparency even after being placed under high temperature and high humidity.

The adhesive composition of the present invention contains a urethane resin (A) and a curing agent (B).

The aforementioned urethane resin (A) is a reaction product of a polyol (a1) and a polyisocyanate (a2).

The aforementioned polyol (a1) is a compound having two hydroxyl groups in one molecule, and contains a polymer polyol (a1-1) and a polyol (a1-2) having a carboxyl group.

The number average molecular weight of the aforementioned polymer polyol (a1-1) is preferably 500 or more, preferably 700 or more, more preferably 900 or more, preferably 10,000 or less, preferably 5,000 or less, more preferably 3,000 or less, particularly Preferably, it is 1,200 or less.

In the present invention, the number average molecular weight and the weight average molecular weight indicate values obtained by using gel permeation chromatography in terms of polystyrene.

The aforementioned polymer polyol (a1-1) can be used singly or in two or more types, and examples thereof include polyether polyols, polyester polyols, and polycarbonate polyols.

Examples of the aforementioned polyether polyols include: using one or more compounds having two or more active hydrogen atoms (for example, a molecular weight of 50 or more and less than 500) as an initiator, and an alkylene oxide (Alkylene oxide) It is formed by addition polymerization, or, as required, one or two or more of the aforementioned compounds with two or more active hydrogen atoms (for example, a molecular weight of 50 or more and less than 500) are used as the initiator and the cyclic ether is processed Those formed by ring-opening polymerization.

The aforementioned compounds having two or more active hydrogen atoms can be used in one or two or more types, for example: ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanedi Alcohol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, bisphenol A, glycerin, trimethylolethane, trimethylolpropane, etc. .

The said alkylene oxide can use 1 type, or 2 or more types, for example, ethylene oxide, propylene oxide, butylene oxide, epichlorohydrin etc. are mentioned. Examples of the aforementioned cyclic ether include tetrahydrofuran, alkyl-substituted tetrahydrofuran, and the like.

The aforementioned polyether polyols can particularly use polytetramethylene glycol derivatives obtained by reacting polyethylene glycol, polypropylene glycol, polytetramethylene glycol, tetrahydrofuran and alkyl-substituted tetrahydrofuran; neopentyl glycol and tetrahydrofuran Polytetramethylene glycol derivatives formed by copolymerization, etc. Among them, the aforementioned polyether polyol is preferably polypropylene glycol, polytetramethylene glycol (PTMG), and polytetramethylene glycol derivatives (PTXG).

The aforementioned polyether polyol contains at least a polyether polyol having an oxyalkylene unit having 4 or more carbon atoms at a ratio of 10% by mass or more. By containing an oxyalkylene unit having 4 or more carbon atoms, it becomes easy to suppress changes in surface characteristics.

In the aforementioned polymer polyol (a1-1), the content of the polyether polyol is preferably 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and preferably 100% by mass or less.

As the polyester polyol, for example, an esterification reaction product of a low-molecular polyol and a polycarboxylic acid, a ring-opening polymer of a cyclic ester compound such as ε-caprolactone, and a combination of the aforementioned esterification reaction product and a ring-opening polymer can be used. Copolymerization of polyester, etc.

Examples of the aforementioned polycarboxylic acids include: aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dodecane dicarboxylic acid; terephthalic acid, isophthalic acid, phthalic acid, and naphthalene dicarboxylic acid Aromatic dicarboxylic acids such as acids; and such anhydrides or esters.

Examples of the aforementioned polycarbonate polyol include the reaction of carbonate and/or phosgene, and low-molecular-weight polyols. The aforementioned carbonates can be used singly or in two or more types, for example, alkyl carbonates (for example, methyl carbonate, ethyl carbonate, etc.), dialkyl carbonates (for example, dimethyl carbonate, diethyl carbonate, etc.) Aliphatic carbonates such as cyclic carbonates; carbonates containing alicyclic structures such as cyclic carbonates (hereinafter, "alicyclic structures containing" may be referred to as "alicyclic" for short); aromatics such as diphenyl carbonate Carbonate. Among them, aliphatic carbonate and alicyclic carbonate are preferred, aliphatic carbonate is more preferred, and dialkyl carbonate is still more preferred.

Examples of low-molecular polyols capable of reacting with the aforementioned carbonates and phosgene include: ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, and dipropylene glycol , Tripropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanedi Alcohol, 1,6-hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-butyl-2-ethyl-1,3- Aliphatic polyols such as propylene glycol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol; 1,4- Alicyclic polyols such as cyclohexanedimethanol; hydroquinone, resorcinol; aromatic polyols such as bisphenol A, bisphenol F, 4,4'-biphenol, etc.

The aforementioned low-molecular polyols are preferably aliphatic polyols, alicyclic polyols, more preferably aliphatic polyols, and still more preferably 1,2-propanediol, 1,4-butanediol, 1,5-pentane Glycol, 3-methyl-1,5-pentanediol, 1,6-hexanediol.

The aforementioned polycarbonate polyol is preferably an aliphatic polycarbonate polyol which is a reactant of aliphatic carbonate and aliphatic polyol; belongs to aliphatic carbonate and/or alicyclic carbonate and aliphatic polyol and / Or alicyclic polycarbonate as a reactant of alicyclic polyol Alcohol etc.

In the aforementioned polyol (a1), the content of the polymer polyol (a1-1) is preferably 50% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, and preferably 100% by mass or less.

The aforementioned polyol (a1-2) having a carboxyl group can be used in one or two or more types, and examples include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, and 2,2- Hydroxy acids such as dimethylolbutyric acid and 2,2-dimethylvaleric acid; and reactants of the aforementioned polyhydric alcohol with a carboxyl group and the aforementioned polycarboxylic acid, etc. The aforementioned polyol (a1-2) having a carboxyl group is preferably a hydroxy acid, more preferably 2,2-dimethylolpropionic acid.

The content of the aforementioned carboxyl group-containing polyol (a1-2) is preferably 1 part by mass or more, preferably 2 parts by mass or more, and more preferably 3 parts by mass relative to 100 parts by mass of the aforementioned polymer polyol (a1-1) Above, it is preferably 50 parts by mass or less, preferably 30 parts by mass or less, and more preferably 20 parts by mass or less.

In the aforementioned polyol (a1), the total content of the aforementioned polymer polyol (a1-1) and the aforementioned carboxyl group-containing polyol (a1-2) is preferably 50% by mass or more, preferably 80% by mass or more, and more Preferably it is 90 mass% or more, and it is 100 mass% or less favorable.

The said polyol (a1) may contain other polyols (a1-3) other than the said polymer polyol (a1-1) and the said carboxyl group-containing polyol (a1-2).

The aforementioned polyisocyanate (a2) can be used in one type or two or more types, and examples include diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and carbodiimide-modified diphenylmethane diisocyanate. , Crude diphenylmethane diisocyanate, phenylene diisocyanate, toluene diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate Aromatic polyisocyanates such as isocyanates; aliphatic polyisocyanates such as hexamethylene diisocyanate and lysine diisocyanate; isophorone diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, 4, 4'-Dicyclohexylmethane diisocyanate, 2,4- and/or 2,6-methylcyclohexane diisocyanate, cyclohexyl diisocyanate, methylcyclohexyl diisocyanate, bis(2-isocyanate Ethyl)-4-cyclohexylene-1,2-dicarboxylate and 2,5-and/or 2,6-norbornane diisocyanate, dimer acid diisocyanate, bicycloheptane triisocyanate, hydrogenated Alicyclic polyisocyanates such as xylylene diisocyanate and the like. Among them, aliphatic polyisocyanate and alicyclic polyisocyanate are preferred.

The molar ratio (isocyanate group/hydroxyl group) of the isocyanate group contained in the polyisocyanate (a2) to the hydroxyl group contained in the polyol (a1) is 0.5 or more, preferably 0.7 or more, preferably 0.8 or more, more It is preferably 0.85 or more, the molar ratio is less than 1, and it is preferably 1 or less, and more preferably 0.95 or less.

The aforementioned urethane resin may be obtained by further reacting the polyol (a1) and the polyisocyanate (a2) with the chain extender at the same time. Furthermore, the molar ratio (isocyanate group/hydroxyl group) of the isocyanate group contained in the polyisocyanate (a2) and the hydroxyl group contained in the polyol (a1) may be reacted at a ratio of 1.0 or more isocyanate groups in excess After obtaining the isocyanate-terminated prepolymer, it is formed by reacting a chain extender. When producing the isocyanate-terminated prepolymer, the molar ratio (isocyanate group/hydroxyl group) of the isocyanate group contained in the polyisocyanate (a2) to the hydroxyl group contained in the polyol (a1) is 1.0 or more, preferably 1.05 or more, It is preferably 1.1 or more, and the molar ratio is well below 3.0, preferably 2.5 or less, and more preferably 2.0 or less.

The aforementioned chain extender can be used singly or in two or more types, and examples thereof include compounds having two or more active hydrogen atoms, polyamines, and the like. The aforementioned compounds having two or more active hydrogen atoms include, for example, ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3- Methyl-1,5-pentanediol, 1,6-hexanediol, 3,3'-dimethylolheptane, neopentyl glycol, 3,3-bis(hydroxymethyl)heptane, two Aliphatic chain extenders such as ethylene glycol, dipropylene glycol, polyoxypropylene glycol, polyoxybutylene glycol, glycerin, trimethylolpropane, etc.; 1,2-cyclobutanediol, 1,3-cyclopentanediol, 1 ,4-cyclohexanediol, cycloheptanediol, cyclooctanediol, 1,4-cyclohexanedimethanol, hydroxypropylcyclohexanol, tricyclo[5.2.1.0 ^2,6 ]decane-dimethanol , Bicyclo[4.3.0]-nonanediol, dicyclohexanediol, bicyclo[4.3.0]nonanediol, spiro[3.4]octanediol, butylcyclohexanediol, 1,1'-bicyclohexane Hexyldiol, cyclohexanetriol, hydrogenated bisphenol A, 1,3-adamantanediol and other alicyclic chain extenders, etc.; preferably ethylene glycol, propylene glycol, 1,4-butanediol, 1 , 6-hexanediol, diethylene glycol, neopentyl glycol, 1,3-butanediol and other aliphatic alkanediols; cyclohexanedimethanol and other alicyclic glycols. Furthermore, the aforementioned polyamines may include ethylene diamine, 1,2-propane diamine, 1,6-hexamethylene diamine, piperazine, 2,5-dimethyl piperidine, isophorone diamine, 4, 4'-Dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, 1,4-cyclohexanediamine, N-hydroxymethylaminoethylamine , N-ethylaminoethylamine, N-methylaminopropylamine, diethylenetriamine, dipropylenetriamine, diethylenetetraamine, hydrazine, N,N'-dimethylhydrazine, 1,6-hexa Methylene dihydrazine, dihydrazine succinate, dihydrazine adipate, dihydrazine glutarate, dihydrazine sebacate, dihydrazine isophthalate, β-aminourea propionate , 3-aminourea-propyl-carbazide, aminourea-3-aminoureamethyl-3,5,5-trimethylcyclohexane and other polyamine extension agents.

When the aforementioned chain extender is contained, relative to the aforementioned polyol (a1), the content of the chain extender is preferably 0.01% by mass or more, preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and preferably 5% by mass or less , Preferably 3% by mass or less, more preferably 1% by mass or less.

The urethane resin (A) may be obtained by further reacting the reactant of the polyol (a1), the polyisocyanate (a2), and a chain extender used as needed, and a terminal stopper. The isocyanate group can be inactivated by using a terminal stopper.

The aforementioned terminal stopper is preferably an alcohol, and examples thereof include monofunctional alcohols such as methanol, ethanol, propanol, and butanol; difunctional alcohols such as 1,2-propanediol and 1,3-butanediol; and multifunctional polyols; Alkanolamine compounds such as alkanolamine (for example, ethanolamine, etc.) and alkanoldiamine (for example, diethanolamine, etc.).

When using the aforementioned terminator, the molar ratio of the active hydrogen atom-containing group contained in the terminator to the cyanate ester group contained in the polyisocyanate (a2) is preferably 1.0 or more, preferably 1.2 or more, more preferably It is 1.5 or more, preferably 10.0 or less, preferably 5.0 or less, more preferably 3.0 or less.

The acid value of the urethane resin (A) is preferably 5 mgKOH/g or more, preferably 7 mgKOH/g or more, preferably 50 mgKOH/g or less, preferably 45 mgKOH/g or less, and more preferably 35 mgKOH/g or less.

The number average molecular weight of the aforementioned urethane resin (A) is preferably 7,000 or more, preferably 9,000 or more, more preferably 10,000 or more, preferably 80,000 or less, preferably 60,000 or less, more preferably 40,000 or less.

The weight average molecular weight of the aforementioned urethane resin (A) is preferably 10,000 or more, preferably 20,000 or more, more preferably 30,000 or more, preferably 100,000 or less, preferably 70,000 or less, and more preferably 50,000 or less.

The molecular weight dispersion of the aforementioned urethane resin (A) is preferably 1.8 or higher, preferably 2 or higher, more preferably 2.3 or higher, preferably 7 or lower, and preferably 5 or lower.

In this specification, the number average molecular weight and the weight average molecular weight can be measured using gel permeation chromatography, and polystyrene is used as a standard sample.

The aforementioned urethane resin (A) can be made of polyol (a1) and polyisocyanate The acid ester (a2) is produced by reacting with a chain extender and/or terminal stopper as required. The aforementioned reaction may be carried out in the presence of an organic solvent, or a urethane catalyst may coexist during the aforementioned reaction.

The aforementioned organic solvents can be used in one or two or more types, for example: aromatic hydrocarbon solvents such as toluene; ester solvents such as ethyl acetate and butyl acetate; acetone, methyl ethyl ketone, cyclohexanone, 3-pentanone Ketone solvents such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, ethyl carbitol and other ether solvents; acetonitrile, propionitrile, isobutyronitrile, valeronitrile and other nitrile solvents; dimethyl Sulfide solvents such as sulfide; sulfide solvents such as methylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, etc.

The aforementioned ethyl urethane catalyst can use, for example, nitrogen-containing compounds such as triethylamine, triethylenediamine, and N-methylmorpholine; metal salts such as potassium acetate, zinc stearate, and tin octoate; dibutyltin laurate, two Organometallic compounds such as dioctyltin neodecanoate and zirconium tetraacetate.

唑基等。前述具有能夠與羧基反應的官能基之硬化劑(b1)可舉出具有2個以上能夠與羧基反應的官能基之化合物等。前述具有能夠與羧基反應的官能基之硬化劑(b1)，可列舉例如：環氧硬化劑、碳二亞胺硬化劑、氮丙啶硬化劑、

唑啉硬化劑等，亦可將該等組合而使用。其中，較佳為含有環氧硬化劑及碳二亞胺硬化劑中的至少1種。 The aforementioned curing agent (B) contains a curing agent (b1) having a functional group capable of reacting with a carboxyl group. The aforementioned functional groups capable of reacting with carboxyl groups include epoxy groups, carbodiimide bonding groups (-N=C=N-), aziridinyl groups,

Azole and so on. Examples of the aforementioned curing agent (b1) having a functional group capable of reacting with a carboxyl group include a compound having two or more functional groups capable of reacting with a carboxyl group. The aforementioned curing agent (b1) having a functional group capable of reacting with a carboxyl group includes, for example, epoxy curing agent, carbodiimide curing agent, aziridine curing agent,

An oxazoline hardener etc. can also be used in combination with these. Among them, it is preferable to contain at least one of an epoxy curing agent and a carbodiimide curing agent.

One or more of the aforementioned epoxy hardeners that can be used include, for example, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6- Hexanediol Diglycidyl Ether, Diethylene Glycol Diglycidyl Ether, Polyethylene Glycol Diglycidyl Ether, Polypropylene Glycol Diglycidyl Ether, Glycerin Diglycidyl Ether, Cyclohexane Dimethanol Diglycidyl Ether, Resorcinol Diglycidyl Ether, Phenol (EO) 5 Glycidyl Ether , Bis-(p-hydroxyphenyl) methane diglycidyl ether, 2,2-bis-(p-hydroxyphenyl) propane diglycidyl ether, ginseng-(p-hydroxyphenyl) methane polypropylene oxide Base ether, 1,1,2,2-tetra-(p-hydroxyphenyl) ethane polyglycidyl ether, lauryl alcohol (EO) 15 glycidyl ether and other aliphatic; alicyclic or aromatic polyol Diglycidyl ether of compounds; glycerol triglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, trimethylolpropane triglycidyl ether, sorbitol Polyglycidyl ether of aliphatic, alicyclic or aromatic polyol compounds such as polyglycidyl ether, neopentyl erythritol, polyglycidyl erythritol, etc.; N,N-diglycidyl Aniline, N,N-diglycidyltoluidine 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetracyclic Polyglycidyl ether of amine compounds such as oxypropyl-m-xylene diamine, N,N,N',N'-tetraepoxypropyl-bis-(p-aminophenyl)methane; terephthalic acid Diglycidyl ester, diglycidyl isophthalate, diglycidyl naphthalate, polyglycidyl trimellitate, diglycidyl adipate, Diglycidyl ester or polyglycidyl ester of fatty acid or aromatic acid such as diglycidyl sebacate; triglycidyl aminophenol; triglycidyl ginseng (2-hydroxyethyl) Base) isocyanurate, triglycidyl isocyanurate; o-cresol type epoxy resin, phenol novolac type epoxy resin, etc.

、磺醯苯并

等苯并

化合物；磺醯化合物等。 When the aforementioned epoxy curing agent is used, an epoxy curing catalyst may coexist. Examples of the epoxy curing catalyst include tertiary amine compounds such as imidazole and dimethylaminopyridine; phosphorus compounds such as triphenylphosphine; trifluoride such as boron trifluoride and boron trifluoride monoethylamine complexes. Boronated amine complexes; organic oxygen compounds such as thiodipropionic acid; thiodiphenol benzo

Sulfonated benzo

Benzo

Compounds; sulfonate compounds and so on.

The aforementioned carbodiimide hardener can be used in one kind or two or more kinds, examples can be given Such as: N,N'-di-o-tolylcarbodiimide, N,N'-diphenylcarbodiimide, N,N'-di-2,6-dimethylphenylcarbodiimide Imine, N,N'-bis(2,6-diisopropylphenyl)carbodiimide, N,N'-dioctyldecylcarbodiimide, N-triyl-N'-ring Hexylcarbodiimide, N,N'-di-2,2-di-tert-butylphenylcarbodiimide, N-triyl-N'-phenylcarbodiimide, N,N'- Di-p-nitrophenylcarbodiimide, N,N'-di-p-aminophenylcarbodiimide, N,N'-bis-p-hydroxyphenylcarbodiimide, N,N'-di -Cyclohexylcarbodiimide, and N,N'-di-p-tolylcarbodiimide, etc.

The above-mentioned aziridine curing agent can be used in one kind or two or more kinds, for example, 2,2'-bishydroxymethylbutanol ginseng [3-(1-aziridinyl) propionate], 4,4 '-Bis(ethyleneiminocarbonylamino)diphenylmethane and the like.

唑啉硬化劑能夠使用1種或2種以上，可列舉例如：2’-亞甲基雙(2-

唑啉)、2,2’-伸乙基雙(2-

唑啉)、2,2’-伸乙基雙(4-甲基-2-

唑啉)、2,2’-丙烯雙(2-

唑啉)、2,2’-四亞甲基雙(2-

唑啉)、2,2’-六亞甲基雙(2-

唑啉)、2,2’-八亞甲基雙(2-

唑啉)、2,2’-對伸苯基雙(2-

唑啉)、2,2’-對伸苯基雙(4,4’-二甲基-2-

唑啉)、2,2’-對伸苯基雙(4-甲基-2-

唑啉)、2,2’-對伸苯基雙(4-苯基-2-

唑啉)、2,2’-間伸苯基雙(2-

唑啉)、2,2’-間伸苯基雙(4-甲基-2-

唑啉)、2,2’-間伸苯基雙(4,4’-二甲基-2-

唑啉)、2,2’-間伸苯基雙(4-伸苯基雙-2-

唑啉)、2,2’-鄰伸苯基雙(2-

唑啉)、2,2’-鄰伸苯基雙(4-甲基-2-

唑啉)、2,2’-雙(2-

唑啉)、2,2’-雙(4-甲基-2-

唑啉)、2,2’-雙(4-乙基-2-

唑啉)、2,2’-雙(4-苯基-2-

唑啉)等的

唑啉化合物；2-異丙烯基-2-

唑啉、2-異丙烯基-4,4-二甲基-2-

唑啉等使乙烯系單體共聚合而成之具有

唑啉基之共聚物等。 Aforementioned

The oxazoline curing agent can be used in one kind or two or more kinds, for example:

Oxazoline), 2,2'-ethylenebis(2-

Oxazoline), 2,2'-ethylenebis(4-methyl-2-

Oxazoline), 2,2'-propylene bis(2-

Oxazoline), 2,2'-tetramethylene bis(2-

Oxazoline), 2,2'-hexamethylene bis(2-

Oxazoline), 2,2'-octamethylene bis(2-

Oxazoline), 2,2'-p-phenylene bis(2-

Oxazoline), 2,2'-p-phenylene bis(4,4'-dimethyl-2-

Oxazoline), 2,2'-p-phenylene bis(4-methyl-2-

Oxazoline), 2,2'-p-phenylene bis(4-phenyl-2-

Oxazoline), 2,2'-m-phenylene bis(2-

Oxazoline), 2,2'-methylene bis(4-methyl-2-

Oxazoline), 2,2'-methylene bis(4,4'-dimethyl-2-

Oxazoline), 2,2'-m-phenylene bis (4-phenylene bis-2-

Oxazoline), 2,2'-o-phenylene bis(2-

Oxazoline), 2,2'-o-phenylene bis(4-methyl-2-

Oxazoline), 2,2'-bis(2-

Oxazoline), 2,2'-bis(4-methyl-2-

Oxazoline), 2,2'-bis(4-ethyl-2-

Oxazoline), 2,2'-bis(4-phenyl-2-

Oxazoline) etc.

Oxazoline compound; 2-isopropenyl-2-

Oxazoline, 2-isopropenyl-4,4-dimethyl-2-

Oxazoline, etc., made by copolymerization of vinyl monomers.

Oxazoline-based copolymers, etc.

The carboxyl group in the aforementioned urethane resin (A) and the energy contained in the hardener (B) The molar ratio of the group capable of reacting with the carboxyl group (carboxyl group/functional group capable of reacting with the carboxyl group) is preferably 1 or more, preferably 1.2 or more, more preferably 1.5 or more, and the molar ratio is preferably 5 or less, preferably 4 Below, it is more preferably 3 or less.

In the curing agent (B), the content of the curing agent (b1) having a functional group capable of reacting with a carboxyl group is preferably 10% by mass or more, preferably 30% by mass or more, more preferably 40% by mass or more, which is good It is 100% by mass or less.

The aforementioned curing agent (B) may further contain another curing agent (b2) in addition to the aforementioned curing agent (b1) having a functional group capable of reacting with a carboxyl group. Examples of the aforementioned other curing agent (b2) include isocyanate curing agents and the like.

The aforementioned isocyanate curing agent can be used singly or two or more, for example: toluene diisocyanate, chlorobenzene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, xylylene diisocyanate, isophor Polyisocyanates such as ketone diisocyanate, diphenylmethane diisocyanate, and hydrogenated diphenylmethane diisocyanate; trimethylolpropane adducts of these polyisocyanates; isocyanurate bodies of these polyisocyanates; Biuret bodies of these polyisocyanates, etc. Among these, it is preferable to use a trimethylolpropane adduct of polyisocyanate and an isocyanurate body of polyisocyanate.

When the other curing agent (b2) is contained, the content of the other curing agent (b2) is preferably 5 parts by mass or more relative to 100 parts by mass of the curing agent (b1) having a functional group capable of reacting with the carboxyl group, preferably 20 parts by mass or more, more preferably 30 parts by mass or more, preferably 200 parts by mass or less, preferably 150 parts by mass or less, more preferably 130 parts by mass or less.

With respect to 100 parts by mass of the urethane resin (A), the content of the curing agent (B) is preferably 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and preferably 10 parts by mass Hereinafter, it is preferably 7 parts by mass or less.

The total content of the urethane resin (A) and the curing agent (B) is based on the solid content of the adhesive composition, preferably 80% by mass or more, preferably 90% by mass or more, more preferably 95 Mass% or more, and good is 100 mass% or less.

In addition, in this specification, the solid content of the adhesive composition refers to the part after the solvent contained in the adhesive composition is removed.

The aforementioned adhesive composition may further contain a hardening catalyst. Examples of the curing catalyst include the same compounds as those exemplified as the urethane catalyst and epoxy curing catalyst. When the curing catalyst is contained, relative to 100 parts by mass of the urethane resin (A), the content of the curing catalyst is preferably 0.001 parts by mass or more, preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, which is good It is 1 part by mass or less, preferably 0.1 part by mass or less, and more preferably 0.05 part by mass or less.

The aforementioned adhesive composition may further contain a plasticizer. The aforementioned plasticizers include: aliphatic polycarboxylic acid esters such as adipate, citrate, sebacate, azelate, and maleate; terephthalate, isobenzene Diformate, phthalate, trimellitate, benzoate and other aromatic polycarboxylic acid esters; ether modified polyester; epoxy modified polyester; composed of polycarboxylic acid and polyol The formed polyester and so on.

When the plasticizer is contained, relative to 100 parts by mass of the urethane resin (A), the content of the plasticizer is preferably 0.1 parts by mass or more, preferably 1 part by mass or more, and preferably 50 parts by mass or less, It is preferably 40 parts by mass or less, and more preferably 30 parts by mass or less.

The aforementioned adhesive composition may further contain a solvent. Examples of the aforementioned solvent include the same compounds as those exemplified as the aforementioned organic solvent. When containing the aforementioned organic solvents, In the aforementioned adhesive composition, the organic solvent content is preferably 20% by mass or more, more preferably 30% by mass or more, more preferably 80% by mass or less, and more preferably 70% by mass or less. In the adhesive composition of the present invention, in the aforementioned solvent, the water content is preferably 10% by mass or less, preferably 5% by mass or less, more preferably 1% by mass or less, and the lower limit is 0% by mass.

The aforementioned adhesive composition may further contain a silane coupling agent, an antioxidant, a light stabilizer, a rust inhibitor, a thixotropy imparting agent, a sensitizer, a polymerization inhibitor, a leveling agent, an adhesion imparting agent, an antistatic agent, and an antistatic agent. Burning agent, etc. as other additives. In the adhesive composition, the content of the other additives is preferably 10% by mass or less, preferably 5% by mass or less, more preferably 1% by mass or less, and the lower limit is 0% by mass.

By coating the adhesive composition on the substrate, removing the solvent as required, and further curing as required, the adhesive layer of the hardened substance of the adhesive composition can be formed. The thickness of the aforementioned adhesive layer is preferably 10 μm or more, preferably 20 μm or more, more preferably 30 μm or more, preferably 200 μm or less, preferably 100 μm or less, and more preferably 80 μm or less.

The method of forming a sheet from the aforementioned adhesive composition includes, for example, a method of coating the aforementioned adhesive composition on a plastic substrate and drying/curing.

For the aforementioned plastic substrate, for example, polyester resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate can be used; polyolefin resins such as polyethylene and polypropylene; Polyacrylic resin; Polyvinyl chloride resin; Polypropylene vinyl vinyl alcohol; Polyvinyl alcohol resin; Polyurethane resin; Polyamide resin; Polyimide resin and the like to obtain a sheet or film. It is also possible to perform release treatment, antistatic treatment, corona treatment, etc. on the surface of these plastic substrates. Furthermore, the thickness of the aforementioned plastic substrates is, for example, in the range of 10 to 200 μm.

The method of coating the aforementioned adhesive composition on the aforementioned plastic substrate can include using Use roll coater, gravure coater, reverse roll coater, spray coater, air knife coater, die coater and other coating methods.

The adhesive layer of the hardened product of the aforementioned adhesive composition is capable of suppressing changes in the surface characteristics of the substrate before and after it is peeled off, and can be used as a surface protective film, especially as an information display for protecting electronic devices such as display devices. The surface protective film of the part is useful.

[Example]

Hereinafter, the present invention will be explained more specifically by giving examples.

(Production Example 1: Production of Urethane Resin (I))

In a four-necked flask equipped with a stirrer, reflux cooling tube, thermometer, and nitrogen blowing tube, add polytetramethylene ether glycol (number average molecular weight: 1,010.9, hydroxyl value: 111.0) 477.62 parts by mass, neopentyl glycol under nitrogen flow After 0.28 parts by mass and uniformly mixed, 133.04 parts by mass of isophorone diisocyanate was added, and then 0.1 part by mass of tin octoate was added and reacted at 90°C for about 3 hours, thereby obtaining an isocyanate group at the end of the molecule. Urethane prepolymer (a).

Next, the urethane prepolymer (a) obtained by the aforementioned method was cooled to 60°C, and 14.96 parts by mass of 2,2-bis(hydroxymethyl)propionic acid and 268.24 parts by mass of methyl ethyl ketone were added. Next, 0.3 parts by mass of tin octoate was added and reacted at 75° C. for about 5 hours to obtain a methyl ethyl ketone solution of urethane prepolymer (b) having an isocyanate group at the molecular end (solid content 70 mass %).

Next, the methyl ethyl ketone solution of the urethane prepolymer (b) obtained by the aforementioned method was cooled to 50°C, 2.39 parts by mass of diethanolamine, which is a terminal stopper, was added, and after confirming that the isocyanate disappeared, it was added 359.99 parts by mass of methyl ethyl ketone was cooled to room temperature to obtain a methyl ethyl ketone solution (solid content 50% by mass) of urethane resin (I). The amine The acid value of the ethyl formate resin (I) is 10mgKOH/g, and the molecular weight distribution coefficient by GPC means the average molecular weight (Mn) is 10,389, the weight average molecular weight (Mw) is 56,341, and the molecular weight dispersion (Mw/Mn) is 5.43 .

(Production Example 2: Production of Urethane Resin (II))

In a four-necked flask equipped with a stirrer, a reflux cooling tube, a thermometer and a nitrogen blowing tube, polytetramethylene ether glycol (number average molecular weight: 1,010.9, hydroxyl value: 111.0) 405.26 parts by mass, neopentyl glycol was added under nitrogen flow After 2.02 parts by mass and uniformly mixed, 170.79 parts by mass of isophorone diisocyanate was added, and then 0.2 parts by mass of tin octoate was added, and the reaction was carried out at 90°C for about 3 hours, thereby obtaining an isocyanate group at the molecular end. Urethane prepolymer (c).

Next, the urethane prepolymer (c) obtained by the aforementioned method was cooled to 60°C, and 44.65 parts by mass of 2,2-bis(hydroxymethyl)propionic acid and 266.88 parts by mass of methyl ethyl ketone were added. Next, 0.3 parts by mass of tin octoate was added and reacted at 75°C for about 5 hours to obtain a methyl ethyl ketone solution of urethane prepolymer (d) having an isocyanate group at the molecular end (solid content 70% by mass) ).

Next, the methyl ethyl ketone solution of the urethane prepolymer (d) obtained by the aforementioned method was cooled to 50° C., 3.07 parts by mass of diethanolamine, which is a terminal stopper, was added, and after confirming that the isocyanate disappeared, the methyl ethyl ketone was added. 352.47 parts by mass of methyl ethyl ketone was cooled to room temperature to obtain a methyl ethyl ketone solution (solid content 50% by mass) of urethane resin (II). The acid value of the urethane resin (II) is 30mgKOH/g, the molecular weight distribution coefficient by GPC, the weight average molecular weight (Mn) is 10,063, the weight average molecular weight (Mw) is 56,728, and the molecular weight dispersion (Mw/Mn) Is 5.64.

(Production Example 3: Production of Urethane Resin (III))

In a four-necked flask equipped with a stirrer, a reflux cooling tube, a thermometer, and a nitrogen blowing tube, add a polyester diol composed of 3-methyl-1,5-pentanediol and adipic acid (number average molecular weight) under a nitrogen stream. 977.44, hydroxyl value: 114.8) 322.83 parts by mass, 422.76 parts by mass of ethyl acetate and uniformly mixed, add 100.00 parts by mass of hexamethylene diisocyanate, and then add 0.01 parts by mass of dioctyltin dineodecanoate, It was allowed to react at 75°C for about 3 hours, thereby obtaining an ethyl acetate solution (solid content 50% by mass) of the urethane prepolymer (e) having an isocyanate group at the molecular terminal.

Next, the ethyl acetate solution of the urethane prepolymer (e) obtained by the aforementioned method was cooled to 40°C, and polyoxyethylene polyoxypropylene triol (manufactured by Sanyo Kasei Co., Ltd.) was added. "Sannix GL-3000", molar ratio [EO/PO]=25/75, number average molecular weight; 3,077.1, hydroxyl value: 54.7) 948.55 parts by mass, 315.25 parts by mass of ethyl acetate, and after uniformly mixing, make it in After reacting at 65°C for about 6 hours and cooling to 60°C when the NCO% becomes 0.01% or less, adding 3.43 parts by mass of methanol as a terminal stopper and confirming that NCO disappears, adding 231.66 parts by mass of ethyl acetate and cooling to the room The temperature was warmed to obtain an ethyl acetate solution (solid content 50% by mass) of the urethane resin (III). The acid value of the urethane resin (III) is 0mgKOH/g, the molecular weight distribution coefficient by GPC is 23,434, the weight average molecular weight (Mw) is 129,370, and the molecular weight dispersion (Mw/Mn) Is 5.52.

(Example 1)

100 parts by mass of the methyl ethyl ketone solution (solid content 50% by mass) of the urethane resin (I) obtained in Production Example 1 was mixed with hexamethylene as an isocyanate curing agent just before the sheet was produced Diisocyanate nurate body ("DURANATE TKA-100" manufactured by Asahi Kasei Co., Ltd., hereinafter referred to as "TKA-100") 1.72 parts by mass, as The isocyanate hardening catalyst is 2.00 parts by mass of a 1% by mass methyl ethyl ketone solution of dioctyltin dineodecanoate, 0.50 parts by mass of acetone, and aliphatic polyglycidyl ether as an epoxy hardener (DIC shares Co., Ltd. "CR-5L", hereinafter referred to as "CR-5L") 1.52 parts by mass, 0.05 parts by mass of triphenylphosphine as an epoxy curing catalyst, and 29.82 parts by mass of methyl ethyl ketone to obtain an adhesive composition物 (1) (solid content 40% by mass).

(Example 2)

100 parts by mass of the methyl ethyl ketone solution (solid content 50% by mass) of the urethane resin (II) obtained in Production Example 2 was formulated as an isocyanate curing agent "DURANATE TKA- 100" 1.72 parts by mass, 2.00 parts by mass of 1% by mass methyl ethyl ketone solution of dioctyltin dineodecanoate as an isocyanate hardening catalyst, 0.50 parts by mass of acetone, "CR-5L as an epoxy hardener '' 4.57 parts by mass, 0.14 parts by mass of triphenylphosphine as an epoxy curing catalyst, 2.87 parts by mass of N-methyldiethanolamine, and 34.51 parts by mass of methyl ethyl ketone to obtain adhesive composition (2) (solid content 40 quality%).

(Example 3)

100 parts by mass of the methyl ethyl ketone solution (solid content 50% by mass) of the urethane resin (II) obtained in Production Example 2 was mixed with carbon as a carbodiimide hardener immediately before the sheet was produced Diimine methyl ethyl ketone solution ("CARBODILITE V-09B" manufactured by Nisshinbo Chemical Co., Ltd., solid content 70.26 mass%, hereinafter referred to as "V-09B") 15.91 parts by mass, and methyl ethyl ketone 37.03 Parts by mass to obtain an adhesive composition (3) (solid content 40% by mass).

(Comparative example 1)

The ethyl acetate solution (solid content 50%) of the urethane resin (III) obtained in Production Example 3 Mass %) 100 parts by mass. Just before the sheet is manufactured, 5.00 parts by mass of "DURANATE TKA-100" as an isocyanate curing agent and 1% by mass ethyl acetate of dioctyltin dineodecanoate as an isocyanate curing catalyst are prepared The solution was 2.00 parts by mass, 0.50 parts by mass of acetone, and 32.50 parts by mass of ethyl acetate to obtain an adhesive composition (X1) (solid content 40% by mass).

[Processing method of adhesive sheet]

The resulting adhesive composition was coated on the surface of a polyethylene terephthalate film with a thickness of 50μm so that the film thickness after drying became 65μm and dried at 60°C for 3 minutes, and then heated at 120°C. Dry for 3 minutes at °C. A 38 μm-thick polyethylene terephthalate film with a release treatment on the surface was attached here, and an adhesive sheet was obtained by aging at 40°C for 3 days.

[Evaluation method of white mist]

The surface protection films obtained in the examples and comparative examples were cut into pieces of 50 mm×70 mm and used as test pieces. A single-sided tape with a thickness of 150 μm was cut into a size of 40 mm×60 mm, and the inner side was further cut out by 20 mm×40 mm to produce a frame with a thickness of 150 μm and a width of 10 mm. Attach the manufactured frame to the glass plate, and attach the test piece to it. At this time, since the thickness of the frame is thicker than the film thickness of the adhesive, bubbles of the frame enter both sides. After attaching, let it stand for 3 days in an environment with a temperature of 85°C and a humidity of 85%, then take it out to a 23°C environment and leave it for 1 hour. Peel off the surface protection film from the glass plate, and evaluate the white fog in the air bubbles.

The white mist system is evaluated as follows.

○; no white fog

△; there is a lighter white fog

×; white fog

[Table 1]

Examples 1 to 3 are examples of the present invention, and the transparency can be maintained even after being placed under high temperature and high humidity. Comparative Example 1 does not contain a hardener having a functional group capable of reacting with a carboxyl group. After being placed under high temperature and high humidity, the transparency is reduced (white haze is generated).

Claims (6)

An adhesive composition containing urethane resin (A) and hardener (B), in which, The aforementioned urethane resin (A) is a reaction product of polyol (a1) and polyisocyanate (a2), The aforementioned polyol (a1) contains a polymer polyol (a1-1) and a polyol (a1-2) having a carboxyl group, The aforementioned curing agent (B) contains a curing agent having a functional group capable of reacting with a carboxyl group. The adhesive composition according to the first item of the scope of patent application, wherein the acid value of the urethane resin (A) is 5 mgKOH/g or more and 50 mgKOH/g or less. The adhesive composition according to item 1 or 2 of the scope of patent application, wherein the curing agent (B) further contains an isocyanate curing agent. The adhesive composition according to any one of items 1 to 3 in the scope of the patent application, wherein the content of the hardener (B) is 1 part by mass relative to 100 parts by mass of the urethane resin (A) Above and 50 parts by mass or less. An adhesive sheet is formed by the adhesive composition described in any one of items 1 to 4 in the scope of the patent application. A surface protective film containing the adhesive sheet described in item 5 of the scope of patent application.