TWI840642B - Two-component curing urethane adhesive, cured product of two-component curing urethane adhesive, and urethane adhesive sheet - Google Patents

Abstract

The object of the present invention is to provide a two-component curable urethane adhesive which can obtain an adhesive sheet showing excellent cured film properties, which can be peeled off with very small force, and which has little change in adhesive force before and after a heat resistance test. The present invention is a two-component curable urethane adhesive, comprising a main agent and a curing agent, wherein the main agent comprises an urethane resin (P) having a hydroxyl group formed by reacting a polyol component (a) with an urethane prepolymer (b) having an isocyanate group, wherein the polyol component (a) contains a polyfunctional polyoxyalkylene polyol (a1) having a hydroxyl value of 10 to 350 mgKOH/g as an essential component, wherein the polyfunctional polyoxyalkylene polyol (a1) is a polyoxyalkylene polyol (a11) having a hydroxypropyl group at a molecular terminal and/or an ethylene oxide adduct (a12) thereof represented by the general formula (1), and wherein the curing agent comprises a crosslinking agent (D) having an isocyanate group. [In the general formula (1), X is an m-valent residue obtained by removing all active hydrogen atoms from a compound having m active hydrogen atoms; A is an alkylene group having 2 to 12 carbon atoms which may be substituted by a phenyl group, a halogenphenyl group or a halogen atom; Z is a propylene group; m is an integer of 4 to 10; p is an integer of 0 to 199; q is an integer of 1 to 200, and 1≦p+q≦200 is satisfied.]

Description

Two-component curing urethane adhesive, cured product of two-component curing urethane adhesive, and urethane adhesive sheet

The present invention relates to a two-component curable urethane adhesive, a cured product of the two-component curable urethane adhesive, and an urethane adhesive sheet.

Optical component sheets can be made of substrates (polyester, polyethylene, polypropylene, glass, etc.) with adhesives laminated on them. Optical component sheets are used by manufacturers of optical components such as polarizing plates to protect the surface of optical components when they are shipped. In addition, manufacturers of image display devices such as liquid crystal displays use them to protect optical components during the manufacturing process of display devices (liquid crystal modules) or to attach optical components to each other.

Although acrylic adhesives have been mainly used for these optical component sheets, urethane adhesives have also been studied for reasons such as good tracking properties to the adherend and excellent adhesive properties (for example, Patent Document 1). However, the urethane adhesive disclosed in Patent Document 1 must use a large amount of hardener, increase crosslinking points, or increase urethane base concentration in order to show the strength of the adhesive sheet, and has problems such as poor flexibility, brittle cured film of the obtained adhesive, and large changes in adhesive force before and after heat resistance tests. In addition, because the adhesive force of the adhesive sheet is not low enough, a large force is required to peel the sheet from the optical component, resulting in poor workability. [Prior Technical Document] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2006-182795

[The problem the invention is trying to solve]

The subject of the present invention is to provide a two-component curing urethane adhesive, which can obtain an adhesive sheet showing excellent curing film properties, can be peeled off with very small force, and has little change in adhesive force before and after the heat resistance test. [Technical means to solve the problem]

The inventors of the present invention have completed the present invention after intensive research to solve the above problems. That is, the present invention is a two-component curable urethane adhesive, a cured product of the two-component curable urethane adhesive, and an urethane adhesive sheet formed by using the two-component curable urethane adhesive. The two-component curable urethane adhesive contains a main agent and a curing agent. The main agent contains an urethane resin (P) having a hydroxyl group formed by reacting a polyol component (a) with an urethane prepolymer (b) having an isocyanate group. The polyol component (a) is a polyfunctional polyoxyalkylene polyol (polyoxyalkylene) having a hydroxyl value of 10 to 350 mgKOH/g. The present invention relates to a novel polyoxyalkylene polyol (a1) as an essential component, wherein the multifunctional polyoxyalkylene polyol (a1) is a polyoxyalkylene polyol (a11) having a hydroxypropyl group at the molecular terminal represented by the general formula (1) and/or an ethylene oxide adduct (a12) thereof, and the curing agent contains a crosslinking agent (D) having an isocyanate group.

[In the general formula (1), X is an m-valent residue obtained by removing all active hydrogen atoms from a compound having m active hydrogen atoms; A is an alkylene group having 2 to 12 carbon atoms which may be substituted by a phenyl group, a halogen phenyl group or a halogen atom; Z is a propyl group; m is an integer of 4 to 10; p is an integer of 0 to 199; q is an integer of 1 to 200, and satisfies 1≦p+q≦200. ] [Comparison with the efficacy of the prior art]

The two-component curable urethane adhesive of the present invention can obtain an adhesive sheet showing excellent curing film properties, which can be peeled off with very small force and has a small change in adhesive force before and after a heat resistance test.

In the two-component curable urethane adhesive of the present invention, the main agent contains an urethane resin (P) having a hydroxyl group obtained by reacting a polyol component (a) with an urethane prepolymer (b) having an isocyanate group.

The polyol component (a) in the present invention has as an essential component a polyfunctional polyoxyalkylene polyol (a1) having a hydroxyl value of 10 to 350 mgKOH/g. The above-mentioned polyfunctional polyoxyalkylene polyol (a1) has as an essential component a polyoxyalkylene polyol (a11) having a hydroxypropyl group at the molecular end represented by the general formula (1) and/or its ethylene oxide adduct (a12).

[In the general formula (1), X is an m-valent residue obtained by removing all active hydrogen atoms from a compound having m active hydrogen atoms; A is an alkylene group having 2 to 12 carbon atoms which may be substituted by a phenyl group, a halogen phenyl group or a halogen atom; Z is a propylene group; m is an integer from 4 to 10; p is an integer from 0 to 199; q is an integer from 1 to 200, and 1≦p+q≦200 is satisfied.]

X in the general formula (1) is an m-valent residue obtained by removing all active hydrogen atoms from a compound having m active hydrogen atoms, and m is an integer of 4 to 10. If m is less than 4, the peeling force of the obtained adhesive increases, the cured film becomes brittle, or the adhesive force is not low enough. If m exceeds 10, the viscosity of the multifunctional polyoxyalkylene polyol (a1) increases, the viscosity of the mixed solution of the main agent and the curing agent increases when applied, and the cutting property of the cured product also decreases. In addition, the cutting property of the cured product refers to the property of suppressing the generation of chips when the cured product of the two-component curing urethane adhesive is cut with a cutter blade or the like. Furthermore, it is preferred that the cut surface is smooth. Generally speaking, the cutting property of the cured product is a property opposite to the reduction of the peeling force. From the viewpoint of adhesion to the substrate, reduction of peeling force and improvement of cutting property of the cured product, m is preferably 5 to 8, and more preferably 6. As the compound having m active hydrogen atoms constituting the residual group X, there can be mentioned: compounds containing hydroxyl groups, compounds containing amino groups, compounds containing carboxyl groups, and thiols, etc., compounds having a group selected from hydroxyl groups, primary or secondary amino groups, carboxyl groups and hydroxyl groups.

Examples of the above-mentioned hydroxyl-containing compounds include: 4- to 10-valent polyols (neopentaerythritol, sorbitol, xylitol, and mannitol); their intermolecular or intramolecular dehydrates (e.g., dipentaerythritol and sorbitan); polyglycerols (polymerization degree 2 to 8); sugars and their derivatives (e.g., glucose, sucrose, fructose, α-methyl glucoside and glycoside); polymers or oligomers having m hydroxyl groups and a number average molecular weight of 2,000 or less {polydiene (carbon number 4 to 10) polyols (e.g., polybutadiene polyols and hydrogenates thereof); (co)polymers of hydroxyalkyl (carbon number 2 to 4) (meth)acrylates; polyvinyl alcohol (saponification degree 60% or more); and mixtures of two or more of these.

In addition, the number average molecular weight in the present invention can be measured by gel permeation chromatography, for example, under the following conditions. Apparatus: "Waters Alliance 2695" [manufactured by Waters] Column: "Guardcolumn Super H-L" (1 piece), "one piece each of TSKgel SuperH2000, TSKgel SuperH3000, and TSKgel SuperH4000 (all manufactured by Tosoh Co., Ltd.) connected" Sample solution: 0.25 wt% tetrahydrofuran solution Solution injection volume: 10μl Flow rate: 0.6ml/min Measurement temperature: 40°C Detection device: Refractive index detector Reference material: Standard polyethylene glycol

As the amine group-containing compound, there can be mentioned: polyamines having 4 to 10 active hydrogen atoms [aliphatic diamines having 2 to 12 carbon atoms or more {alkylene diamines having 2 to 12 carbon atoms (e.g., ethylenediamine, propylenediamine, hexamethylenediamine, etc.), alicyclic diamines having 6 to 15 carbon atoms (1,4-diaminocyclohexane, isophoronediamine, and 4,4'-diaminocyclohexylmethane, etc.)}, aromatic diamines having 6 to 15 carbon atoms {m-phenylenediamine or p-phenylenediamine, toluenediamine, diethyltoluenediamine, 4,4'-diaminophenylmethane, and 2,2-bis(4,4'-diaminophenyl)propane, etc.}, aromatic aliphatic diamines having 8 to 15 carbon atoms (m-xylylenediamine or p-xylylenediamine e), heterocyclic polyamines with 4 to 10 carbon atoms {piperidinium, amine alkyl (2 to 4 carbon atoms) piperidine (e.g., amine ethyl piperidine), amine alkyl (2 to 4 carbon atoms) imidazole, etc.}, polyalkylene polyamines with 2 to 4 carbon atoms in the alkylene group {diethylenetriamine, dipropylenetriamine, triethylenetetramine, polyethyleneimine with a number average molecular weight of less than 2,000, and mono-, di- or tri-alkyl (1 to 4 carbon atoms) polyalkylene polyamines ( For example, dimethyltriethylenetetramine, etc.); hydroxyalkyl (carbon number 2-4) mono- or di-alkanol (carbon number 2-4) amines (N,N-bis (2-hydroxyethyl) ethylenediamine, etc.); polymers or oligomers having one or more amino groups and a number average molecular weight of 2,000 or less [aminoalkyl (carbon number 2-4) (meth) acrylate (co)polymers, etc.]; and mixtures of two or more of these.

Examples of carboxyl group-containing compounds include aromatic polycarboxylic acids having 8 to 30 carbon atoms (e.g., naphthalenetetracarboxylic acid and pyromelitic acid), unsaturated carboxylic acid polymers [e.g., (meth)acrylic acid (co)polymers having a number average molecular weight of 2,000 or less], and mixtures of two or more thereof.

Examples of the thiol include 4- to 10-valent polythiol having 2 to 6 or more carbon atoms (for example, pentaerythritol tetra(3-butylbutyrate) etc.).

Among these, from the viewpoint of curability, the preferred ones are hydroxyl-containing compounds and amine-containing compounds, and further preferred ones are 4-10-valent polyols {neopentaerytol, sorbitol, xylitol and mannitol, etc.}; their intermolecular or intramolecular dehydrates (e.g. dipentaerytol and sorbitan; polyglycerol (polymerization degree 2-8); carbohydrates and their derivatives (e.g. glucose, fructose, sucrose, α-methyl glucoside and glycoside, etc.);

In the general formula (1), A is an alkylene group having 2 to 12 carbon atoms which may be substituted by a phenyl group, a halogenphenyl group or a halogen atom, and examples thereof include a linear or branched alkylene group having 2 to 12 carbon atoms, a cycloalkylene group having 6 to 10 carbon atoms, and a group in which at least a part of the hydrogen atoms possessed by the alkylene group is substituted by a phenyl group, a halogenphenyl group or a halogen atom (such as Cl and Br).

Specific examples of A include ethyl, 1,2- or 1,3-propyl, 1,2-, 2,3-, 1,3- or 1,4-butyl, 1,2-alkylene having 5 to 12 carbon atoms (such as 1,2-dodecylene group), 1,2-cyclohexylene, chloropropyl, bromopropyl, phenylethyl and chlorophenylethyl.

(A-O) in the general formula (1) is a moiety derived from AO obtained by adding alkylene oxide (hereinafter abbreviated as AO) to a compound having m active hydrogen atoms constituting the residue X. Examples of the AO used include ethylene oxide (hereinafter abbreviated as EO), 1,2-propylene oxide (hereinafter abbreviated as PO), 1,3-propylene oxide, 1,2-, 1,3-, 2,3- or 1,4-butylene oxide (hereinafter abbreviated as BO), α-olefin oxides having 5 to 12 carbon atoms, epihalohydrins (epichlorohydrin, epibromohydrin, etc.), styrene oxide, styrene oxide, 1,2-epoxyhexane, and combinations of two or more thereof. When p (A-O)s are composed of two or more oxyalkylene groups, the bonding pattern may be either block or random. Among these, PO and 1,2-BO are preferred from the viewpoint of the softness of the cured product.

In the general formula (1), Z is a propylene group, specifically, a 1,2- or 1,3-propylene group. In the general formula (1), p is an integer of 0 to 199, q is an integer of 1 to 200, and 1≦p+q≦200 is satisfied. From the viewpoint of adhesion to the substrate, the value of p+q is preferably 50 or less, and more preferably 30 or less.

The polyfunctional polyoxyalkylene polyol (a1) is preferably a polyol having a group represented by the general formula (2) and/or a group represented by the general formula (3) at a molecular terminal.

In general formula (2) and general formula (3), a is independently an integer greater than or equal to 0. When a is 0, general formula (2) and (3) represent the molecular end of polyoxyalkylene polyol (a11), and when a is greater than or equal to 1, general formula (2) and (3) represent the molecular end of ethylene oxide adduct (a12) of polyoxyalkylene polyol (a11). In addition, regarding the ratio of the total number of groups represented by general formula (2) possessed by polyfunctional polyoxyalkylene polyol (a1), from the viewpoint of the fracture strength and cutting property of the cured product, the total number of groups represented by general formula (2) possessed by polyfunctional polyoxyalkylene polyol (a1) and the total number of groups represented by general formula (3) are preferably 40% or more, and more preferably 60% or more.

Confirmation of whether the polyoxyalkylene polyol (a11) has a hydroxypropyl group at the molecular end can be performed, for example, by ¹ H-NMR. The hydroxypropyl group includes a primary hydroxyl group-containing group (a hydroxyl group bonded to a primary carbon) represented by the following chemical formula (4) and a secondary hydroxyl group-containing group (a hydroxyl group bonded to a secondary carbon) represented by the following chemical formula (4'). The ratio of the number of primary hydroxyl group-containing groups to the total number of primary hydroxyl group-containing groups and secondary hydroxyl group-containing groups in the polyoxyalkylene polyol (a11), i.e., the primary hydroxyl content (hereinafter referred to as the primary content ratio), is preferably 40% or more, and more preferably 60% or more, from the viewpoint of adhesion.

The primary conversion rate can be determined by pre-treating (esterifying) the sample and then measuring it by ¹ H-NMR method.

The following describes the details of the ¹ H-NMR method. <Sample preparation method> About 30 mg of the test sample is weighed into a 5 mm diameter NMR sample tube, and about 0.5 ml of a deuterated solvent is added to dissolve it. Then, about 0.1 ml of trifluoroacetic anhydride is added to prepare a sample for analysis. As the above-mentioned deuterated solvent, a solvent that can dissolve the sample can be appropriately selected from deuterated chloroform, deuterated toluene, deuterated dimethyl sulfoxide, deuterated dimethylformamide, etc. <NMR measurement> ¹ H-NMR measurement is performed under general conditions. <Calculation method of primary conversion rate> Through the above-mentioned previous treatment method, the hydroxyl group at the end of the polyoxyalkylene polyol will react with the added trifluoroacetic anhydride to form a trifluoroacetate ester. As a result, the signal from the methylene group bonded to the primary hydroxyl group is observed at around 4.3ppm, and the signal from the methine group bonded to the secondary hydroxyl group is observed at around 5.2ppm. The primary rate is calculated by the following formula. Primary rate (%) = [x/(x+2×y)]×100 [where x is the integrated value of the signal from the methylene group bonded to the primary hydroxyl group at around 4.3ppm, and y is the integrated value of the signal from the methine group bonded to the secondary hydroxyl group at around 5.2ppm.]

Regarding the above-mentioned multifunctional polyoxyalkylene polyol (a1), in other words, it is preferable to satisfy the following conditions. When the above-mentioned multifunctional polyoxyalkylene polyol (a1) is only the above-mentioned polyoxyalkylene polyol (a11), it is preferable that the primary hydroxyl content of the polyoxyalkylene polyol (a11) is at least 40%. When the polyoxyalkylene polyol (a11) is two or more kinds, it is preferable that the primary hydroxyl content of the mixture is at least 40%. Furthermore, when the above-mentioned multifunctional polyoxyalkylene polyol (a1) is only the above-mentioned ethylene oxide adduct (a12), it is preferable that the primary hydroxyl content of (a11) before the addition of ethylene oxide is at least 40%. When there are two or more types of (a11) before ethylene oxide addition, it is preferred that the primary hydroxyl content of the mixture is at least 40%. In addition, when the polyfunctional polyoxyalkylene polyol (a1) is a mixture of the polyoxyalkylene polyol (a11) and the ethylene oxide adduct (a12), it is preferred that when there is a mixture of (a11) before ethylene oxide addition of (a12) and (a11) contained in the polyfunctional polyoxyalkylene polyol (a1), the primary hydroxyl content of the mixture is at least 40%. Furthermore, the ratio of the total number of groups represented by the general formula (2) possessed by the polyfunctional polyoxyalkylene polyol (a1) is preferably 60% or more based on the total number of groups represented by the general formula (2) and the number of groups represented by the general formula (3) possessed by the polyfunctional polyoxyalkylene polyol (a1), from the viewpoint of improving the breaking strength of the cured product and the cutting properties.

The polyoxyalkylene polyol (a11) can be produced, for example, by the method described in Japanese Patent Application Publication No. 2000-344881. As a preferred example of the polyoxyalkylene polyol (a11), there can be cited: in the presence of tris(pentafluorophenyl)borane catalyst (hereinafter abbreviated as TPB), PO is subjected to ring-opening addition polymerization to an active hydrogen-containing compound (a0) represented by the following general formula (5). When TPB is used as a catalyst to carry out the ring-opening addition polymerization of PO, there is a tendency that the addition of PO proceeds so that the terminal hydroxyl group selectively becomes a group of the chemical formula (4).

X, A, p and m in the general formula (5) are the same as those in the above general formula (1).

As specific examples of active hydrogen-containing compounds (a0), when p is 0, the same compounds as those exemplified as compounds having m active hydrogen atoms constituting the residue of general formula (1) can be cited. In addition, in this specification, the compound obtained by adding PO to the compound in which p is 0 in general formula (5) is a compound in which p is 0 and q is 1 or more in general formula (1).

When p is 1 or more, the active hydrogen-containing compound (a0) is a polyol obtained by (co)adding AO to a compound constituting a residue X using a conventionally known catalyst (alkali metal hydroxide, etc.). Preferred examples include: PO adducts or PO/1,2-BO coadducts (block or random) of neopentyltritol, PO adducts or PO/1,2-BO coadducts (block or random) of dipentyltritol, PO adducts or PO/1,2-BO coadducts (block or random) of polyglycerol, PO adducts or PO/1,2-BO coadducts (block or random) of sorbitol, PO adducts or PO/1,2-BO coadducts (block or random) of sucrose, and the like.

The amount of TPB used when preparing the multifunctional polyoxyalkylene polyol (a1) by ring-opening addition polymerization of PO to the active hydrogen-containing compound (a0) is not particularly limited, but is preferably 0.00005 to 10% by weight, more preferably 0.0001 to 1% by weight, based on the weight of the multifunctional polyoxyalkylene polyol (a1).

The added molar number of PO is 1 to 200 moles, preferably 2 to 100 moles, and more preferably 3 to 30 moles per active hydrogen atom of the active hydrogen-containing compound (a0). The added molar number of all AO (the sum of AO in the first stage and PO in the second stage) per active hydrogen atom of the compound constituting the residual group X is 1 to 200 moles, and more preferably 3 to 100 moles. If the added molar number exceeds 200 moles, the viscosity of the polyfunctional polyoxyalkylene polyol (a1) increases, the viscosity of the mixed solution of the main agent and the curing agent increases, and the cutting property of the cured product decreases.

Therefore, q in the general formula (1) is 1 to 200, preferably 2 to 100, and more preferably 3 to 30. Furthermore, p+q in the general formula (1) is 1 to 200, and more preferably 3 to 100.

The reaction temperature for the ring-opening addition polymerization of PO is preferably 0 to 250° C., more preferably 20 to 180° C. From the viewpoint of controlling the reaction temperature, the following method is preferred: dropping PO into a mixture of an active hydrogen-containing compound (a0) and TPB, or dropping a mixture of PO and TPB into an active hydrogen-containing compound (a0).

Since the obtained addition polymer contains TPB, it is better to use synthetic silicates (magnesium silicate and aluminum silicate, etc.) and activated clay as adsorbents for adsorption removal.

The EO adduct (a12) of the polyoxyalkylene polyol (a11) can be obtained by adding EO to the polyoxyalkylene polyol (a11) by a conventional method. The amount of the added oxyalkylene group is 40% by weight or less, preferably 30% by weight or less, and particularly preferably 10% by weight or less, based on the total weight of the oxyalkylene groups in the EO adduct (a12).

The total content of the polyoxyalkylene polyol (a11) and/or the EO adduct (a12) in the polyol component (a) of the present invention is preferably 50% by weight or more, and more preferably 70% by weight or more, based on the weight of the polyol component (a). If it is less than 50% by weight, it may be difficult to obtain the effect of the present invention.

The hydroxyl value of the multifunctional polyoxyalkylene polyol (a1) is 10 to 350 mgKOH/g. When the hydroxyl value is less than 10 mgKOH/g, the cutting property of the cured product is deteriorated. When the hydroxyl value exceeds 350 mgKOH/g, the peeling force increases, and the bonding performance between the adhesive and the adherend deteriorates (bubbles occur, resulting in poor yield). From the perspective of improving the cutting property of the cured product, the hydroxyl value of the multifunctional polyoxyalkylene polyol (a1) is preferably 28 mgKOH/g or more, and more preferably 45 mgKOH/g or more. The hydroxyl value can be measured by the method described in JIS K 1557-1.

The polyoxyalkylene polyol (a11) and its EO adduct (a12) may be used in combination of two or more types. Examples of the combined use include: the combined use of different types of bases [compounds having m active hydrogen atoms constituting the residue X in the general formula (1)] [e.g., compounds based on polyols (sorbitol, etc.) and compounds based on polyamines (triethylenetetramine, etc.)], compounds having different numbers of functional groups [m in the general formula (1)] [e.g., compounds based on 4-5 functional compounds (pentylene triol, etc.) and compounds based on 5-10 functional compounds (dopentatriol, sorbitol, sucrose, etc.)], compounds having different hydroxyl values or AO addition molar numbers [p+q in the general formula (1)] [combined use of compounds having a hydroxyl value of 300 mgKOH/g or more and compounds having a hydroxyl value of less than 300 mgKOH/g (preferably, compounds having a hydroxyl value of 30 mgKOH/g or more but less than 300 mgKOH/g)], etc.

Preferred specific examples of the multifunctional polyoxyalkylene polyol (a1) constituting the polyol component (a) of the present invention include PO adducts and PO/1,2-BO co-adducts (blocks) of pentaerythritol, PO adducts and PO/1,2-BO co-adducts (blocks) of dipentaerythritol, PO adducts and PO/1,2-BO co-adducts (blocks) of polyglycerol, PO adducts and PO/1,2-BO co-adducts (blocks) of sorbitol, PO adducts and PO/1,2-BO co-adducts (blocks) of sucrose, etc. Among these, from the viewpoints of "film strength of adhesive" and "no flaking and easy removal during peeling", PO adducts and PO/1,2-BO coadducts (blocks) of sorbitol are preferred, and PO50-200 mol adducts of sorbitol are particularly preferred.

The polyol component (a) in the present invention may contain other polyols (a2) in addition to the above-mentioned polyfunctional polyoxyalkylene polyol (a1).

Examples of the other polyols (a2) other than the multifunctional polyoxyalkylene polyol (a1) include polyether alcohols, polyester polyols, polyolefin polyols, polyalkadiene polyols, and acrylic polyols.

Examples of the polyether alcohol include polyethylene glycol, polytetramethylene ether glycol, poly-3-methyltetramethylene ether glycol, copolymerized polyoxyalkylene glycols [EO/PO copolymerized glycols, THF/EO copolymerized glycols and THF/3-methyltetrahydrofuran copolymerized glycols having no hydroxypropyl group at the terminal (weight ratio is, for example, 1/9 to 9/1)], and AO adducts of bisphenol compounds having no hydroxypropyl group at the terminal; polyether alcohols having three or more functions and containing a hydroxyalkyl group other than a hydroxypropyl group at the terminal, for example, AO adducts of trivalent or more polyols [AO adducts of glycerol and AO adducts of trihydroxymethylpropane, etc.]; and products obtained by coupling one or more of these with dichloromethane.

As polyester polyols, castor oil fatty acid ester polyols (e.g. castor oil, partially dehydrated castor oil and castor oil fatty acid esters) can be cited; poly (n = 2 to 3 or more) carboxylic acids [aliphatic saturated or unsaturated polycarboxylic acids (carbon number 2 to 40, such as oxalic acid, adipic acid, azelaic acid, dodecanoic acid, succinic acid, fumaric acid, itaconic acid and dimerized linolenic acid), aromatic ring-containing polycarboxylic acids (carbon number 8 to 15, such as Linear or branched polyester polyols formed by polyols [such as phthalic acid, isophthalic acid, terephthalic acid and 2,6-naphthalene dicarboxylic acid] and alicyclic polycarboxylic acids (carbon number 7 to 15, such as 1,3-cyclopentane dicarboxylic acid and 1,4-cyclohexane dicarboxylic acid)] and polyols [such as the above-mentioned hydroxyl-containing compounds, multifunctional polyoxyalkylene polyols (a1) and other polyols (a2)]; Polylactone polyols (polylactone polyol) [for example, a polyol obtained by addition-polymerizing (substituted) caprolactone (having 6 to 10 carbon atoms, such as ε-caprolactone, α-methyl-ε-caprolactone and ε-methyl-ε-caprolactone) with one or a mixture of two or more of the above-mentioned hydroxyl-containing compounds (divalent to trivalent) as a base in the presence of a catalyst (such as an organic metal compound, a metal chelate compound and a fatty acid metal acyl compound) (such as polycaprolactone polyol)]; a polyetherester polyol obtained by addition-polymerizing AO (such as EO and PO) to a polyester having a carboxyl group and/or a hydroxyl group at the terminal, and which is neither a polyoxyalkylene polyol (a11) nor an EO adduct thereof (a12); polycarbonate polyol, etc.

Examples of the polyolefin polyol include polyisobutylene polyol and the like. Examples of the polydiene polyol include polyisoprene polyol, polybutadiene polyol, hydrogenated polyisoprene polyol and hydrogenated polybutadiene polyol and the like.

Examples of acrylic polyols include copolymers of alkyl (meth)acrylate (alkyl group having 1 to 30 carbon atoms) esters [butyl (meth)acrylate, etc.] and hydroxyl-containing acrylic monomers [hydroxyethyl (meth)acrylate, etc.]. When other polyols (a2) are used, their content is preferably 0.1 to 5% by weight based on the total weight of the polyol component (a).

The hydroxyl equivalent weight (number average molecular weight per hydroxyl group) of the polyol component (a) in the present invention is preferably 500 or more.

The amine prepolymer (b) having an isocyanate group in the present invention is an amine prepolymer having an isocyanate group composed of a polyol component (ap) and a polyisocyanate component (bp).

As the above-mentioned polyol component (ap), polyether alcohol, polyester polyol, polyolefin polyol, polydiene polyol and acrylic polyol can be used. Among them, from the perspective of the strength of the obtained urethane adhesive sheet and reducing the peeling force, polyether alcohol, polyester polyol and acrylic polyol are preferred, and further preferred are difunctional polyether alcohol, and particularly preferred are difunctional polypropylene glycol and difunctional polytetramethylene ether glycol or their derivatives (compounds in which the hydrogen atom of the methylene group is substituted with an alkyl group with 1 to 4 carbon atoms, etc.). As the above-mentioned alkyl group with 1 to 4 carbon atoms, methyl, ethyl, propyl, isopropyl, butyl and the like can be cited. In addition, from the perspective of improving the cutting properties of the cured product and reducing the peeling force, difunctional polytetramethylene ether glycol or its derivatives are preferred.

The polyisocyanate component (bp) in the present invention includes those having 2 to 3 or more isocyanate groups, for example: a chain aliphatic polyisocyanate with 4 to 22 carbon atoms (bp1), a cyclic aliphatic polyisocyanate with 8 to 18 carbon atoms (bp2), an aromatic polyisocyanate with 8 to 26 carbon atoms (bp3), an aromatic aliphatic polyisocyanate with 10 to 18 carbon atoms (bp4), and modified products of these polyisocyanates (bp5). The polyisocyanate component (bp) may be used alone or in combination of two or more.

Examples of the chain aliphatic polyisocyanate (bp1) having 4 to 22 carbon atoms include ethyl diisocyanate, butyl diisocyanate, hexamethylene diisocyanate (hereinafter abbreviated as HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylhexanoate, bis(2-isocyanatoethyl)fumarate, bis(2-isocyanatoethyl)carbonate, and 2-isocyanatoethyl-2,6-diisocyanatohexanoate.

Examples of the alicyclic polyisocyanate (bp2) having 8 to 18 carbon atoms include isophorone diisocyanate (hereinafter, abbreviated as IPDI), 4,4'-dicyclohexylmethane diisocyanate (hereinafter, abbreviated as hydrogenated MDI), cyclohexyl diisocyanate, methylcyclohexyl diisocyanate, bis(2-isocyanatoethyl)-4-cyclohexene-1,2-dicarboxylate, and 2,5- or 2,6-isocyanatoethyl. Alkane diisocyanate, etc.

Examples of the aromatic polyisocyanate (bp3) having 8 to 26 carbon atoms include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-methylphenylene diisocyanate (hereinafter, abbreviated as TDI), crude TDI, 4,4'- or 2,4'-diphenylmethane diisocyanate (hereinafter, abbreviated as MDI), crude MDI, polyaryl polyisocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4',4"-triphenylmethane triisocyanate, and m- or p-isocyanatophenylsulfonyl isocyanate.

Examples of the aromatic aliphatic polyisocyanate (bp4) having 10 to 18 carbon atoms include p-isocyanate and α,α,α',α'-tetramethylisocyanate.

As modified products (bp5) of polyisocyanates (bp1) to (bp4), there can be mentioned: modified products of the above polyisocyanates (containing urethane groups, carbodiimide groups, allophanate groups, urea groups, biuret groups, uretdione groups, uretonimine groups, isocyanurate groups or oxazolidinone groups, etc.; free isocyanate The present invention relates to a modified polyisocyanate having an ester content of 8 to 33% by weight, preferably 10 to 30% by weight, and particularly 12 to 29% by weight), for example, modified MDI (amine-modified MDI, carbodiimide-modified MDI, and trihydrocarbylphosphate-modified MDI, etc.), amine-modified TDI, biuret-modified HDI, isocyanurate-modified HDI, and isocyanurate-modified IPDI.

Among these polyisocyanate components (bp), from the viewpoint of the strength and adhesion of the obtained urethane adhesive sheet, the preferred ones are the chain aliphatic polyisocyanate (bp1) having 4 to 22 carbon atoms and the alicyclic polyisocyanate (bp2) having 8 to 18 carbon atoms, and more preferred ones are HDI and IPDI.

As the amine prepolymer (b), a compound represented by the general formula (6) is preferred.

In the general formula (6), L is a divalent group obtained by removing an isocyanate group from the polyisocyanate component (bp), U represents an amine ester bond, R is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, b is an integer of 20 to 70, and the numerical average value of s is 1.01 to 10. The numerical average value of s is an average value calculated from the number average molecular weight of the compound represented by the general formula (6). Examples of the alkyl group having 1 to 4 carbon atoms include the same alkyl groups having 1 to 4 carbon atoms as exemplified for the derivative of the bifunctional polytetramethylene ether glycol of the polyol component (ap). In the general formula (6), b is preferably an integer of 25 to 60. In the general formula (6), the numerical average value of s is preferably 1.01 to 5. The amine prepolymer (b) is preferably a compound having a number average molecular weight of 1,400 to 5,100, more preferably 2,000 to 3,000, of the portion (CHR-CHR-CHR-CHR-O) _b in the general formula (6).

From the viewpoint of the strength and adhesion of the obtained urethane adhesive sheet, in the case where the polyol component (ap) and the polyisocyanate component (bp) are reacted in the urethane prepolymer (b) having an isocyanate group, the ratio of the isocyanate group equivalent of (bp) to the active hydrogen-containing group equivalent of (ap) (isocyanate group equivalent/active hydrogen-containing group equivalent) is preferably 1.1 to 2.0, further preferably 1.2 to 1.8, and particularly preferably 1.3 to 1.7. In addition, from the viewpoint of the strength and adhesion of the obtained urethane adhesive sheet, the weight average molecular weight of the urethane prepolymer (b) is preferably 2,000 to 100,000, further preferably 3,000 to 50,000, and particularly preferably 4,000 to 30,000. The weight average molecular weight of the amine prepolymer (b) can be measured by the method described below. The amine prepolymer (b) is preferably a bifunctional compound (i.e., a compound having 2 moles of isocyanate groups per 1 mole of the amine prepolymer (b)). The isocyanate group content of the amine prepolymer (b) is preferably 0.1 to 12% by weight, more preferably 0.3 to 1.5% by weight, based on the weight of the amine prepolymer (b). The isocyanate group content can be measured according to JIS K7301-1995, 6.3 Isocyanate group content.

The amine prepolymer (b) having an isocyanate group of the present invention can be obtained by reacting a polyol component (ap) with a polyisocyanate component (bp) by a general method. As a method for producing the amine prepolymer (b) in the present invention, for example, there can be cited a method of reacting a polyol component (ap) with a polyisocyanate component (bp) in the presence or absence of a solvent (toluene, xylene, ethyl acetate, butyl acetate, dimethylformamide, acetone, methyl ethyl ketone and tetrahydrofuran, etc.). The amine prepolymer (b) having an isocyanate group at the end can be produced by reducing the ratio of the active hydrogen-containing group equivalent of (ap) to the isocyanate equivalent of (bp) (preferably adjusted within the above-mentioned ratio range of the isocyanate group equivalent of (bp) to the active hydrogen-containing group equivalent of (ap)). Furthermore, the above reaction can also be carried out in the presence of an anti-gelling agent (the same compound as the curing retarder described below can be used).

The reaction can be carried out using a known reaction apparatus (a mixing tank equipped with a stirrer and a static mixer, etc.). From the viewpoint of reactivity and suppression of thermal degradation, the reaction temperature is preferably 10 to 160°C, more preferably 25 to 120°C. From the viewpoint of stability, it is preferred to replace the gas phase with nitrogen.

The amine resin (P) having a hydroxyl group constituting the main agent of the two-component curable amine adhesive of the present invention can be obtained by reacting the above-mentioned polyol component (a) with the above-mentioned amine prepolymer (b) having an isocyanate group by a general method.

From the viewpoint of the strength and adhesion of the obtained urethane adhesive sheet, when the polyol component (a) is reacted with the urethane prepolymer (b) having an isocyanate group, the ratio of the isocyanate group equivalent of the urethane prepolymer (b) to the active hydrogen-containing group equivalent of the polyol component (a) (isocyanate group equivalent/active hydrogen-containing group equivalent) is 0.05 to 0.7, preferably 0.1 to 0.5, and more preferably 0.15 to 0.4.

The amine resin (P) preferably contains a compound represented by the following general formula (7).

In the general formula (7), K is a 2- to 10-valent group obtained by removing two or more OH groups from the compound of the polyol component (a), and U, R and L are the same as above. In the general formula (7), b is an integer of 20 to 70, preferably an integer of 25 to 60. In the general formula (7), the average value of s is 1.01 to 10, preferably 1.01 to 5. In the general formula (7), t is an integer of 1 or more, preferably an integer of 1 to 10. When t is 2 or more, the block bonds represented by [K-U-[L-U-(CHR-CHR-CHR-CHR-O) _b -U] _s -L-U] _t form a straight chain. In the general formula (7), when K is a trivalent or higher group, the K to which the terminal hydroxyl group of the general formula (7) is bonded may further have one or more amine ester bonds in addition to U represented by the general formula (7) (that is, the above K may have two or more amine ester bonds). Furthermore, when the above K has one or more amine ester bonds other than U represented by the general formula (7), K may have a block represented by [K-U-[L-U-(CHR-CHR-CHR-CHR-O) _b -U] _s -L-U] _t through the amine ester bonds other than U. When K has the above block through the amine ester bonds other than U, the compound represented by the general formula (7) has a branched structure in which a plurality of the above blocks are branched from K.

The weight ratio of the compound represented by the general formula (7) contained in the urethane resin (P) is preferably 30 wt % or more, more preferably 50 wt % or more, particularly preferably 80 wt % or more, and most preferably 90 wt % or more, based on the weight of the urethane resin (P), from the viewpoint of reducing the peeling force and improving the cutting property of the cured product.

The weight average molecular weight of the urethane resin (P) is preferably 10,000 to 500,000, more preferably 120,000 to 500,000, from the viewpoint of the breaking strength, breaking elongation, cutting property and curing property of the cured product.

The weight average molecular weight of the amine prepolymer (b) and the amine resin (P) in the present invention can be measured by gel permeation chromatography, for example, under the following conditions. In addition, when measuring the amine prepolymer (b), the weight average molecular weight is measured for all isocyanate groups of the amine prepolymer (b) reacted with methanol. Furthermore, the weight from methanol is calculated from the isocyanate group content, and the value obtained by subtracting it from the measured weight average molecular weight is used as the weight average molecular weight of the amine prepolymer (b). Device: "HLC-8120GPC" [manufactured by Tosoh Corporation] Guard column: "Guardcolumn HXL-H" [manufactured by Tosoh Corporation] Column: "TSKgel GMHXL" [manufactured by Tosoh Corporation] Sample solution: 0.125 wt% dimethylformamide (containing 0.01M LiBr) solution Solution injection volume: 100μl Flow rate: 1ml/min Measurement temperature: 40℃ Detection device: Refractive index detector Standard substance: Standard polystyrene

As a method for producing the amine resin (P) having a hydroxyl group in the present invention, a known method for producing an amine resin can be used, for example, a method of reacting a polyol component (a) with an amine prepolymer (b) having an isocyanate group in the presence or absence of a solvent (toluene, xylene, ethyl acetate, butyl acetate, dimethylformamide, acetone, methyl ethyl ketone, tetrahydrofuran, etc.). The amine resin (P) having a hydroxyl group at the end can be produced by increasing the ratio of the active hydrogen-containing group equivalent of the polyol component (a) to the isocyanate equivalent of the amine prepolymer (b) (preferably adjusted within the above-mentioned ratio range of the isocyanate group equivalent of the amine prepolymer (b) to the active hydrogen-containing group equivalent of the polyol component (a)). Furthermore, the above reaction can also be carried out in the presence of an anti-gelling agent (the same compound as the curing delay agent described below can be used). By using an anti-gelling agent, the molecular weight of the urethane resin (P) can be increased without gelling, thereby improving the cutting property or elongation at break.

The reaction can be carried out using a known reaction apparatus (a mixing tank equipped with a stirrer and a static mixer, etc.). From the viewpoint of reactivity and suppression of thermal degradation, the reaction temperature is preferably 10 to 160°C, more preferably 25 to 120°C. From the viewpoint of stability, it is preferred to replace the gas phase with nitrogen.

The two-component curable urethane adhesive of the present invention comprises a main agent and a curing agent, wherein the main agent comprises the above-mentioned urethane resin (P), and the curing agent comprises a crosslinking agent (D) having an isocyanate group.

Examples of the crosslinking agent (D) having an isocyanate group include the polyisocyanates exemplified as the polyisocyanate component (bp).

From the viewpoint of curability, the average functional group number of the crosslinking agent (D) is preferably 2 to 6 or more, more preferably 2 to 5, and particularly preferably 3 to 4.

When manufacturing the two-component curable urethane adhesive, the cured product of the two-component curable urethane adhesive, and the adhesive sheet formed using the two-component curable urethane adhesive of the present invention, an amine catalyst may be used depending on the application and the required degree of curability.

As the catalyst for amine esterification, metal catalysts and amine catalysts can be mentioned. As the metal catalyst, tin catalysts (trimethyltin laurate, trimethyltin hydroxide, dimethyltin dilaurate, dibutyltin diacetate, dibutyltin dilaurate, stannous octanoate) can be mentioned. octoate and dibutyltin maleate); lead catalysts (lead oleate, lead 2-ethylhexanoate, lead cycloalkanoate and lead octenate); bismuth catalysts (bismuth carboxylate, bismuth alkoxide and chelate compounds of compounds with dicarbonyl and bismuth); titanium catalysts (titanium isopropyloxytri-N-ethylaminoethylamine (aminato), tetrabutyl titanium ester and tetraisopropyloxybis-dioctyl titanium phosphite); zinc Catalysts (organic zinc complexes, etc.); zirconium catalysts (zirconia tetraacetylpyruvate and zirconium tributoxyacetylpyruvate, etc.); aluminum catalysts (aluminum complexes, etc.); iron catalysts [iron carboxylate compounds (ferric lactate and ricinoleic acid iron, etc.), ferrocene compounds (ferrocene and acetylferrocene, etc.) and ferrophthalocyanine, etc.] and other metal catalysts (cycloalkanoic acid metal salts such as cobalt cycloalkanoate and phenylmercuric propionate, etc.).

As the amine catalyst, there can be mentioned: triethylenediamine, tetramethylethylenediamine, diazabicycloolefins [1,8-diazabicyclo[5.4.0]undecene-7 [DBU (San-Apro Co., Ltd., registered trademark)], etc.], dialkyl (carbon number 1-3) amine alkyl (carbon number 2-4) amine (dimethylaminoethylamine, dimethylaminopropylamine, diethylaminopropylamine and dipropylaminopropylamine, etc.), heterocyclic amine alkyl (carbon number 2-6) amine [2-(1-azabicyclo[5.4.0]undecene-7 [DBU (San-Apro Co., Ltd., registered trademark)], etc.], aziridinyl)ethylamine, 4-(1-piperidinyl)-2-hexylamine, etc.] and N-methyl and N-ethyl phenoxyethanol, etc.

Among these, preferred are diazabicycloolefin, bismuth catalysts, tin catalysts and zinc catalysts, and particularly preferred are DBU, bismuth carboxylate, dibutyltin dilaurate and organic zinc complexes.

The amount of amine ester catalyst used varies depending on the application, but when high rapid curing is required, it is preferably less than 3,000ppm, more preferably 1 to 2,000ppm, and particularly preferably 10 to 1,000ppm based on the weight of the two-component curing amine ester adhesive. Amine ester catalysts can be used alone or in combination of two or more.

The two-component curable urethane adhesive of the present invention may further contain additives such as solvents, antioxidants, curing delay agents, ultraviolet absorbers, plasticizers, adhesives, fillers and pigments as exemplified in the production method of the urethane resin (P) as long as the effect of the present invention is not hindered. The additives may be added to either the main agent or the curing agent, or may be added when the main agent and the curing agent are mixed, but it is preferably added to the main agent in advance.

As antioxidants, hindered phenols phenol) compounds [triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], pentaerythrityl-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and 2,2-thio (thio)-diethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], etc.] and phosphite compounds [tris(2,4-di-tert-butylphenyl) phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl) octyl phosphite, bis(2,6-di-tert-butylphenyl) pentaerythrityl-diphosphite and tetrakis(2,4-di-tert-butylphenyl) 4,4'-biphenylene-diphosphonite, etc.], etc. These antioxidants may be used alone or in combination. From the viewpoint of antioxidant effect and adhesion, the amount of the antioxidant used is preferably 5% by weight or less, more preferably 0.05 to 1% by weight, based on the weight of the two-component curing urethane adhesive.

As hardening delay agents, there are: 2,4-pentanedione (acetyl acetone), 3-methyl-2,4-pentanedione, 2,4-hexanedione, 2,2-dimethyl-3,5-hexanedione, 2,4-heptanedione, 3,5-heptanedione, 2,2,6,6-tetramethyl-3,5-heptanedione, 2,4-octanedione, 2,2,7-trimethyl-3,5-octanedione, 2,4-nonanedione, 3-methyl-2,4-nonanedione, 2-methyl-4,6-nonanedione, 1-phenyl-1,3-butanedione (benzoyl acetone), dibenzoylmethane (dibenzoylmethane) methane) and 2-furanylbenzoylmethane and other β-diketones; methyl acetylacetate, ethyl acetylacetate, propyl acetylacetate, butyl acetylacetate, methyl propionylacetate, ethyl propionylacetate, propyl propionylacetate, isopropyl propionylacetate, butyl propionylacetate, methyl butyrylacetate, ethyl butyrylacetate, propyl butyrylacetate, methyl hexanoylacetate, ethyl hexanoylacetate, propyl hexanoylacetate and butyl hexanoylacetate and other β-ketoesters; dialkyl malonates such as dimethyl malonate, diethyl malonate, methyl ethyl malonate, diisopropyl malonate and dibutyl malonate; acetylacetamides such as N,N-dimethylacetylacetamide and N-ethylacetylacetamide and the like. These curing retardants may be used alone or in combination. From the perspective of curing delay effect and adhesion, the amount of the curing retardant used is preferably 5% by weight or less, and more preferably 0.01 to 3% by weight, based on the weight of the two-component curing urethane adhesive.

As ultraviolet absorbers, there are salicylic acid derivatives (salicylic acid phenyl ester, salicylic acid-p-octylphenyl ester and salicylic acid-p-tert-butylphenyl ester, etc.), diphenyl ketone compounds [2,4-dihydroxydiphenyl ketone, 2-hydroxy-4-methoxydiphenyl ketone, 2,2'-dihydroxy-4-methoxydiphenyl ketone, 2,2'-dihydroxy-4,4'-dimethoxydiphenyl ketone, 2,2'-dihydroxy-4,4'-dimethoxydiphenyl ketone, 5-sulfonic acid diphenyl ketone, 2-hydroxy －4-methoxy-2'-carboxy diphenyl ketone, 2-hydroxy-4-methoxy-5-sulfonic acid diphenyl ketone trihydrate, 2-hydroxy-4-n-octoxy (n-octoxy) diphenyl ketone, 2-hydroxy-4-octadecyloxy diphenyl ketone, 2,2',4,4'-tetrahydroxy diphenyl ketone, 4-dodecyl-2-hydroxy diphenyl ketone, 2-hydroxy-4-(2-hydroxy-3-methacryloxy (methacryloxy group)) propoxydiphenyl ketone and bis(2-methoxy-4-hydroxy-5-benzoylphenyl)methane, etc.], benzotriazole compounds {2-(2'-hydroxy-5'-methyl-phenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butyl-phenyl)benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methyl-phenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butyl-phenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-4'-n-octyloxyphenyl)benzotriazole, 2-(2' 2-(2'-hydroxy-5'-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-pentylphenyl)benzotriazole, 2-[2'-hydroxy-3'-(3",4",5",6"-tetrahydrophthalimidomethyl)-5'-methylphenyl]benzotriazole and 2,2-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], etc.; cyanoacrylate compounds (2-ethylhexyl-2-cyano-3,3'-diphenylacrylate and ethyl-2-cyano-3,3'-diphenylacrylate, etc.). The ultraviolet absorber may be used alone or in combination of two or more. From the viewpoint of the UV absorption effect and adhesion, the amount of the UV absorber used is preferably 5% by weight or less, and more preferably 0.1 to 1% by weight, based on the weight of the two-component curing urethane adhesive.

As plasticizers, hydrocarbons [process oil, liquid polybutadiene, liquid polyisobutylene, liquid polyisoprene, liquid wax, chlorinated wax, wax, copolymers of ethylene and α-olefin (carbon number 3 to 20) (weight ratio 0.1/99.9 to 99.9/0.1) oligomers (weight average molecular weight 5,000 to 100,000) and copolymers of propylene and α-olefin (carbon number 4 to 20) (weight ratio 0.1/99.9 ～99.9／0.1) oligomers (weight average molecular weight 5,000～100,000)]; chlorinated wax; esters [phthalates [diethyl phthalate (DEP), dibutyl phthalate (DBP), di-2-ethylhexyl phthalate (DOP), didecyl phthalate, dilauryl phthalate, dioctadecyl phthalate and diisononyl phthalate, etc.], adipates [di(2-ethylhexyl) adipate (DOA) and dioctyl adipate, etc.] and sebacic acid esters (dioctyl sebacic acid ester, etc.), fatty acid esters (butyl octadecanoate, 2-ethylhexyl palmitate, 2-ethylhexyl palmitate, behenic acid monoglyceride, 2-ethylhexanoic acid cetyl, isopropyl palmitate, isopropyl cholesteryl, methyl coconut oil, methyl laurate, methyl oleate, methyl octadecanoate, isopropyl myristate, octyl myristate [0046] laurate, myristyl myristate, stearyl octadecanoate, 2-ethylhexyl octadecanoate, isotridecyl octadecanoate, 2-ethylhexanoic acid triglyceride, butyl laurate and octyl oleate, etc.), poly (meth) acrylates (butyl polyacrylate, 2-ethylhexyl polyacrylate, etc.); animal and plant fats and oils (linoleic acid and linolenic acid, etc.); and hydrogenated products of these having unsaturated double bonds that can be hydrogenated, etc. The plasticizer may be used alone or in combination of two or more. From the viewpoint of the cohesive force of the adhesive, the amount of the plasticizer used is preferably 100% by weight or less, more preferably 1 to 50% by weight, more preferably 3 to 40% by weight, particularly preferably 5 to 35% by weight, and most preferably 10 to 30% by weight, based on the weight of the two-component curing urethane adhesive.

The weight average molecular weight of the plasticizer can be measured by gel permeation chromatography, for example, under the following conditions. Apparatus: "HLC-8120GPC" [manufactured by Tosoh Corporation] Column: "Guardcolumn HXL-H" (1 piece), "TSKgel GMHXL" (2 pieces) [both manufactured by Tosoh Corporation] Sample solution: 0.25 wt% tetrahydrofuran solution Solution injection volume: 100 μl Flow rate: 1 ml/min Measurement temperature: 40°C Detection device: Refractive index detector Reference material: Standard polystyrene

Examples of the binder include terpene resins, terpene phenol resins, phenol resins, aromatic hydrocarbon modified terpene resins, rosin resins, modified rosin resins, synthetic petroleum resins (aliphatic, aromatic or alicyclic synthetic petroleum resins, etc.), lavender-indene resins, xylene resins, styrene resins, cyclopentadiene resins, and hydrogenated products of these resins having unsaturated double bonds that can be hydrogenated. The binder may be used alone or in combination of two or more. Among these, polar resins are preferred from the viewpoint of adhesiveness, and rosin resins, phenol resins, terpene phenol resins, xylene resins and hydrogenates thereof are further preferred, and terpene phenol resins and hydrogenates thereof are particularly preferred. From the viewpoint of adhesiveness and heat resistance, the amount of the adhesive is preferably 100% by weight or less, more preferably 1 to 50% by weight, more preferably 3 to 40% by weight, particularly preferably 5 to 35% by weight, and most preferably 10 to 30% by weight, based on the weight of the two-component curing urethane adhesive.

As fillers, carbonates (magnesium carbonate and calcium carbonate, etc.), sulfates (aluminum sulfate, calcium sulfate and barium sulfate, etc.), sulfites (calcium sulfite, etc.), molybdenum disulfide, silicates (aluminum silicate and calcium silicate, etc.), diatomaceous earth, diatomite powder, talc, silica and zeolite, etc. The above fillers are microparticles with a volume average particle size of preferably about 0.01 to 5 μm. One type can be used alone or two or more types can be used in combination. From the perspective of the cohesive force of the adhesive, the amount of the filler is preferably less than 250% by weight, and more preferably 0.5 to 100% by weight, based on the weight of the two-component curing urethane adhesive.

As pigments, there are inorganic pigments (alumina white, graphite, titanium oxide, ultrafine titanium oxide, zinc white, black iron oxide, mica iron oxide, lead white, white carbon, molybdenum white, carbon black, lead monoxide, zinc barium white, barite, cadmium red, cadmium mercury red, hematite, molybdenum red, red lead, chromium yellow, cadmium yellow, barium yellow, strontium yellow, Titanium yellow, titanium black, chromium oxide green, cobalt oxide, cobalt green, cobalt/chromium green, ultramarine, iron blue, cobalt blue, cerulean blue, etc. Blue), manganese violet and cobalt violet, etc.) and organic pigments (insect resin, insoluble azo pigments, soluble azo pigments, condensed azo pigments, phthalocyanine blue and dyeing pigments, etc.). The above-mentioned pigments are microparticles with a volume average particle size of preferably about 0.01 to 5 μm. One type can be used alone or two or more types can be used in combination. From the perspective of the cohesive force of the adhesive, the amount of the pigment used is preferably less than 250% by weight, and more preferably 0.1 to 50% by weight, based on the weight of the two-component curing urethane adhesive.

The NCO/OH ratio (isocyanate group equivalent relative to hydroxyl group equivalent) when the main agent and the hardener are mixed is preferably 0.3 to 2.0, more preferably 0.5 to 1.5, and particularly preferably 0.7 to 1.3 from the viewpoint of the film strength and adhesion of the adhesive sheet obtained.

The use of the two-component curable urethane adhesive of the present invention is not particularly limited. For example, the main agent and the curing agent can be mixed, applied to a base film such as a polyester film and a polyolefin film, and cured to obtain an adhesive sheet, which is then attached to an optical component and used as a surface protective film. The cured product formed by curing the two-component curable urethane adhesive of the present invention and the urethane adhesive sheet formed using the two-component curable urethane adhesive of the present invention are also included in the present invention.

Optical components that can be used with two-component curing urethane adhesives and urethane adhesive sheets include polarizing plates, phase difference plates, light diffusion plates, anti-reflection films, electromagnetic wave shielding films, and glass substrates used in liquid crystal displays, organic EL displays, plasma displays, and field emission displays.

As a specific example of the method of forming the urethane adhesive sheet, the following method can be cited. For coating the two-component curing urethane adhesive on the substrate film, a gravure coater, a reverse roll coater, a comma coater, a spin coater, a curtain coater, a slot coater, a bar coater, a die coater or a knife coater can be used. The amount of adhesive applied (solid content) during coating is preferably 0.5 to 300 g/m ² , more preferably 1 to 200 g/m ² , and particularly preferably 10 to 100 g/m ² .

The coating temperature of the adhesive when applied to the substrate film is preferably 10 to 160°C, more preferably 25 to 130°C, from the viewpoint of coating properties and suppression of thermal degradation. The viscosity of the adhesive at the coating temperature is preferably 0.01 to 100 Pa·s, more preferably 0.02 to 50 Pa·s, and particularly preferably 0.03 to 10 Pa·s from the viewpoint of formability (thick coating is possible, and there is no bad appearance such as warping and shrinkage after curing) and coating properties. The viscosity of the present invention can be measured by a B-type rotational viscometer. For lamination, a commonly used dry laminator or extrusion laminator can be used. After stacking, the adhesive is completely cured by curing at 10-50°C for 20-150 hours.

The urethane group concentration of the cured product of the two-component curing urethane adhesive and the urethane adhesive sheet of the present invention is preferably 3 to 25% by weight based on the total weight of the urethane resin (P) having a hydroxyl group in the main agent and the crosslinking agent (D) in the curing agent from the viewpoint of adhesion to the adherend. [Example]

Hereinafter, the present invention will be specifically described by way of embodiments, but the present invention is not limited to these embodiments.

[Manufacturing of polyoxyalkylene polyol] <Manufacturing Example 1> After loading 100 parts by weight of sorbitol and 4.0 parts by weight of potassium hydroxide into a stainless steel autoclave equipped with a stirring device, a temperature control device, a heat exchanger as a condensation device, a raw material supply pipeline, and an exhaust pipeline, 3,200 parts by weight of PO were continuously added to the liquid phase through the raw material supply pipeline over a period of 12 hours, and at the same time, the reaction temperature was controlled to be maintained at 90-100°C. After aging at 100°C for 3 hours, 30 parts by weight of synthetic silicate {"Kyoward600" manufactured by Kyowa Chemical Industry Co., Ltd.} and 40 parts by weight of water were added and treated at 60°C for 3 hours. The product was taken out from the autoclave, filtered through a filter with a pore size of 1 micron, and then dehydrated to obtain polyoxyalkylene polyol (a11-1). The hydroxyl value of (a11-1) was 66 mgKOH/g, the viscosity was 700 mPa·s/25°C, and the primary rate was 2%. In the general formula (1) of (a11-1), p was 0 and q was about 14.

<Production Example 2> In a stainless steel autoclave equipped with a stirring device, a temperature control device, a heat exchanger as a condensing device, a raw material supply pipeline and an exhaust pipeline, 1,000 parts by weight of polyoxyalkylene polyol (a11-1) and 0.09 parts by weight of TPB were charged, and stirring was started, and the pressure in the autoclave and the condensing device was reduced to 0.005 MPa. 50 parts by weight of PO were continuously added to the liquid phase through the raw material supply pipeline over a period of 12 hours, and the reaction temperature was controlled to be maintained at 70-80°C. In order to condense and recover PO in the condensing device, a refrigerant at -30°C was circulated. After aging at 70°C for 4 hours, 200 parts by weight of water were added and heated at 130-140°C for 1 hour. After heating for 1 hour, water was removed by atmospheric distillation for 2 hours, and then steam was introduced, and the pressure was maintained at 0.04-0.07MPa, and the remaining water and by-product low-boiling point compounds were removed by reduced pressure distillation for 3 hours. Then 30 parts by weight of synthetic silicate {"Kyoward600" manufactured by Kyowa Chemical Industry Co., Ltd.} and 40 parts by weight of water were added, stirred at 60°C for 3 hours, taken out from the autoclave, filtered with a filter with a pore size of 1 micron, and dehydrated to obtain polyoxyalkylene polyol (a11-2). The hydroxyl value of (a11-2) is 65mgKOH/g, the viscosity is 800mPa·s/25°C, and the primary rate is 40%. In the general formula (1) of (a11-2), p is 0 and q is approximately 14.

＜Production Example 3＞ Except that the amount of PO added in Production Example 2 was changed to 180 parts by weight, the polyoxyalkylene polyol (a11-3) was obtained in the same manner as in Production Example 2. The hydroxyl value of (a11-3) was 62 mgKOH/g, the viscosity was 980 mPa・s/25°C, and the primary rate was 60%. In addition, p in the general formula (1) of (a11-3) was 0, and q was about 15.

<Production Example 4> In a stainless steel autoclave equipped with a stirring device, a temperature control device, a heat exchanger as a condensing device, a raw material supply pipeline and an exhaust pipeline, 100 parts by weight of pentaerythritol and 0.09 parts by weight of TPB were charged, and stirring was started to reduce the pressure in the autoclave and the condensing device to 0.005 MPa. 2248 parts by weight of PO were continuously added to the liquid phase through the raw material supply pipeline over a period of 12 hours, and the reaction temperature was controlled to be maintained at 70-80°C. In order to condense and recover PO in the condensing device, a refrigerant at -30°C was circulated. After aging at 70°C for 4 hours, 200 parts by weight of water were added and heated at 130-140°C for 1 hour. After heating for 1 hour, the water was removed by atmospheric distillation for 2 hours, and then steam was introduced, and the pressure was maintained at 0.04-0.07MPa, and the remaining water and low-boiling point compounds produced by the by-product were removed by reduced pressure distillation for 3 hours. Then 30 parts by weight of synthetic silicate {"Kyoward600" manufactured by Kyowa Chemical Industry Co., Ltd.} and 40 parts by weight of water were added, stirred at 60°C for 3 hours, taken out from the autoclave, filtered with a filter with a pore size of 1 micron, and dehydrated to obtain polyoxyalkylene polyol (a11-4). The hydroxyl value of (a11-4) is 43mgKOH/g, the viscosity is 940mPa·s/25°C, and the primary rate is 70%. In the general formula (1) of (a11-4), p is 0 and q is approximately 25.

<Production Example 5> Sorbitol was used as a base agent, and PO was reacted in the presence of KOH catalyst to produce polyoxypropylene glycol (primary rate 2%, hydroxyl value 490mgKOH/g). 100 parts by weight of the polyoxypropylene glycol was placed in a stainless steel autoclave equipped with a stirring device, a temperature control device, a heat exchanger as a condensation device, a raw material supply pipeline and an exhaust pipeline. After 0.09 parts by weight of TPB was added, stirring was started, and the pressure in the autoclave and the condensation device was reduced to 0.005MPa. 365 parts by weight of PO were continuously added to the liquid phase through the raw material supply pipeline over a period of 12 hours, and the reaction temperature was controlled to be maintained at 70-80°C. In order to condense and recover PO in the condensation equipment, a refrigerant at -30°C is circulated. After aging at 70°C for 4 hours, 200 parts by weight of water is added and heated at 130-140°C for 1 hour. After heating for 1 hour, the water is removed by atmospheric distillation for 2 hours, and then steam is introduced, and the pressure is maintained at 0.04-0.07MPa, and the remaining water and low-boiling point compounds of the by-product are removed by reduced pressure distillation for 3 hours. Then, 30 parts by weight of synthetic silicate {"Kyoward600" manufactured by Kyowa Chemical Industry Co., Ltd.} and 40 parts by weight of water were added, stirred at 60°C for 3 hours, taken out from the autoclave, filtered with a filter having a pore size of 1 micron, and dehydrated to obtain polyoxyalkylene polyol (a11-5). The hydroxyl value of (a11-5) is 105 mgKOH/g, the viscosity is 690 mPa・s/25°C, and the primary rate is 66%. In the general formula (1) of (a11-5), p is 0 and q is about 8.

<Production Example 6> Using sucrose as a base, PO is reacted in the presence of a KOH catalyst to produce polyoxypropylene glycol (primary rate 2%, hydroxyl value 35 mgKOH/g, p in general formula (1) is 0, q is about 27.), 100 parts by weight of the polyoxypropylene glycol is placed in a stainless steel autoclave equipped with a stirring device, a temperature control device, a heat exchanger as a condensation device, a raw material supply pipeline and an exhaust pipeline, and 4.0 parts by weight of potassium hydroxide is added. Then, 25 parts by weight of EO is continuously added to the liquid phase through the raw material supply pipeline over a period of 12 hours, and at the same time, the reaction temperature is controlled to be maintained at 90-100°C. After aging at 100°C for 3 hours, 30 parts by weight of synthetic silicate {"Kyoward600" manufactured by Kyowa Chemical Industry Co., Ltd.} and 40 parts by weight of water were added and treated at 60°C for 3 hours. The mixture was taken out from the autoclave, filtered through a filter with a pore size of 1 micron, and then dehydrated to obtain a polyoxyalkylene polyol ethylene oxide adduct (a12-1). The hydroxyl value of (a12-1) is 28 mgKOH/g, the viscosity is 1,660 mPa・s/25°C, and a in the general formula (2) or (3) is about 9.

[Synthesis of amine prepolymer with isocyanate group] <Synthesis Example 1> In a four-necked flask equipped with a reflux cooling tube, a stirring rod and a thermometer, 100 parts by weight of PTMG3000 {difunctional polytetramethylene ether glycol, hydroxyl value 39 mgKOH/g, b value in general formula (6) is about 40, manufactured by Mitsubishi Chemical Co., Ltd.}, 9.6 parts by weight of HDI (hexamethylene diisocyanate), 47 parts by weight of ethyl acetate as a solvent, 0.03 parts by weight of Neostann U-600 {manufactured by Nitto Kasei Co., Ltd.} as an amine esterification catalyst, and 0.05 parts by weight of diethyl malonate as an anti-gelling agent were added, and the mixture was reacted at 78°C for 6 hours to obtain a solution of amine prepolymer (b-1) with isocyanate group. The isocyanate content of the solution (b-1) is 1.1%, the concentration is 70% by weight, and the viscosity is 30,000 mPa·s/25°C.

<Synthesis Examples 2 to 8> Except for changing the loading amount to the value shown in Table 1, the solutions of amine prepolymers (b-2) to (b-8) having isocyanate groups were obtained in the same manner as in Synthesis Example 1. The isocyanate group content, concentration and viscosity of the solutions of (b-2) to (b-8) are shown in Table 1. In addition, "PTG-L2000" in Table 1 represents a bifunctional polytetramethylene ether glycol derivative {hydroxyl value 56 mgKOH/g, manufactured by Hodogaya Chemical Industry Co., Ltd., a random copolymer of tetrahydrofuran and 3-methyltetrahydrofuran}, and "IPDI" represents isophorone diisocyanate.

[Table 1] Synthesis Example 1 2 3 4 5 6 7 8 Amine prepolymer having isocyanate group (b) (b-1) (b-2) (b-3) (b-4) (b-5) (b-6) (b-7) (b-8) Polyol component (ap) PTMG3000 100 100 100 100 - 100 100 - PTG-L2000 - - - - 100 - - 100 Polyisocyanate component (bp) HDI (formula weight = 168.2) 9.6 - - - 12.6 - - - IPDI (Formula weight = 222.3) - 12.7 10.8 10.0 - 9.2 15.6 17.6 Solvent Ethyl acetate 47 48 110 110 48 164 77 78 Amine esterification catalyst Neostann U-600 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 Anti-gelling agent Diethyl malonate 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 The s value in general formula (6) 1.67 1.67 2.86 4.00 2.50 6.67 1.02 1.54 Isocyanate content of amine prepolymer solution (%) 1.1 1.1 0.46 0.33 1.1 0.16 1.5 1.5 Concentration of amine prepolymer solution (weight %) 70 70 50 50 70 40 60 60 Viscosity of amine prepolymer solution (mPa・s/25℃) 30,000 22,000 9,200 33,000 16,000 11,000 8,600 6,600

[Synthesis of amine resin with hydroxyl group] <Synthesis Example 9> In a 4-necked flask equipped with a reflux cooling tube, a stirring rod and a thermometer, 15 parts by weight of polyoxyalkylene polyol (a11-1), 16 parts by weight of a solution of an amine prepolymer with an isocyanate group (b-1) and 34.5 parts by weight of ethyl acetate as a solvent were added and reacted at 78°C for 10 hours to obtain a solution of an amine resin with hydroxyl group (P-1). The hydroxyl value of the solution (P-1) was 11.2 mgKOH/g, the concentration was 40% by weight, the viscosity was 6,200 mPa・s/25°C, and the weight average molecular weight was 131,000.

<Synthesis Examples 10 to 24, Comparison with Synthesis Examples 1 to 2> Except for changing the charge amount to the value shown in Table 2, the same method as Synthesis Example 9 was used to obtain solutions of amine resins (P-2) to (P-16) and (P'-1) to (P'-2) having a hydroxyl group. The hydroxyl value, concentration, viscosity, and weight average molecular weight of the solutions of (P-2) to (P-16) and (P'-1) to (P'-2) are shown in Table 2. In Table 2, (a2-1) indicates SANNIX GH-5000 {trifunctional polypropylene glycol, hydroxyl value 33 mgKOH/g, manufactured by Sanyo Chemical Industries, Ltd.}, and (a2-2) indicates SANNIX SP-750 {hexafunctional polypropylene glycol, hydroxyl value 490 mgKOH/g, manufactured by Sanyo Chemical Industries, Ltd.}.

[Table 2] Synthesis Example Comparative Synthesis Example 9 10 11 12 13 14 15 16 17 18 19 20 twenty one twenty two twenty three twenty four 1 2 Amine resin with hydroxyl group (P) (P-1) (P-2) (P-3) (P-4) (P-5) (P-6) (P-7) (P-8) (P-9) (P-10) (P-11) (P-12) (P-13) (P-14) (P-15) (P-16) (P'-1) (P'-2) Polyol component (a) (a11-1) 15 15 - - - - 15 - - - 25 - - - - - - - (a11-2) - - 15 - - - - - - - - - - - - - - - (a11-3) - - - 15 10 8 - 10 16 32 - - - - 15 16 - - (a11-4) - - - - - - - - - - - - - 15 - - - - (a11-5) - - - - - - - - - - - - 15 - - - - - (a12-1) - - - - - - - - - - - 25 - - - - - - (a2-1) - - - - - - - - - - - - - - - - 15 - (a2-2) - - - - - - - - - - - - - - - - - 10 Solution of amine prepolymer having isocyanate group (b) Solution (b-1) 16 - - - - - - - - - - - 26 - - - 17 65 Solution (b-2) - 17 17 16 - - - - - - - - - 13 - - - - Solution (b-3) - - - - 25 - - - - - - - - - - - - - Solution (b-4) - - - - - 38 - - - - - - - - - - - - Solution (b-5) - - - - - - 17 - - - - - - 16 - - - Solution (b-6) - - - - - - - 58 - - - - - - - - - - Solution (b-7) - - - - - - - - 15 29 twenty four 7.1 - - - - - - Solution of (b-8) - - - - - - - - - - - - - - - 14 - - Solvent Ethyl acetate 34.5 34.9 35.0 34.2 21.1 18.9 34.6 15.0 31.4 21.4 16.7 41.0 41.8 31.8 33.9 31.2 35.5 15.0 Ratio (%) of the total number of groups represented by the general formula (2) to the total number of groups represented by the general formula (2) and the number of groups represented by the general formula (3) in the polyol (a1) 2 2 40 60 60 60 2 60 60 60 2 2 66 70 60 60 2 2 Hydroxyl value of amine resin solution (mgKOH/g) 11.2 11.1 11.2 10.7 8.3 6.8 11.2 6.0 11.1 18.0 18.3 7.7 17.8 6.8 10.5 11.5 3.8 1.6 Concentration of amine resin solution (weight %) 40 40 40 40 40 40 40 40 40 60 60 40 40 40 40 40 40 40 Viscosity of urethane resin solution (mPa・s/25℃) 6,200 5,000 5,700 37,000 45,000 55,000 8,900 13,000 20,000 21,000 37,000 45,000 11,000 5,400 9,800 15,000 5,500 14,700 Weight average molecular weight of amine resin (P) 131,000 64,500 64,700 110,000 93,900 106,000 116,000 175,000 304,000 124,000 144,000 442,000 132,000 88,300 122,000 236,000 135,000 49,600

<Examples 1 to 16 and Comparative Examples 1 to 2> The solutions of hydroxyl amine resins (P-1) to (P-16) or (P'-1) to (P'-2) as the main agent, Desmodur XP2675 (D-1) {HDI isocyanurate, manufactured by Covestro Corporation} or Duranate TFD-90B (D-2) {HDI isocyanurate, manufactured by Asahi Kasei Corporation} as the curing agent, ethyl acetate as the solvent, and dibutyltin dilaurate or Borchi Kat22 {manufactured by Borchers Corporation} as the amine esterification catalyst were mixed in the weight proportions listed in Table 3, and centrifuged to defoam to obtain an adhesive solution. Use a rod coater to apply on a 38μm thick polyethylene terephthalate film in a manner such that the film thickness after drying and curing is 30μm. After drying at 130°C for 3 minutes, adhere the peeling film and cure at 50°C for 2 days to obtain an adhesive sheet. Using the obtained adhesive sheet, the initial adhesion, adhesion after the heat resistance test, cutting properties and substrate adhesion are evaluated by the following evaluation method. The results are shown in Table 3. In addition, using the adhesive cured product obtained by changing the polyethylene terephthalate film to a 100μm OPP (stretched polypropylene) film and changing the film thickness after drying and curing to 100μm, the breaking strength, breaking elongation, yield and gel fraction are evaluated by the following method. The results are shown in Table 3.

(1) Method for measuring initial adhesion The adhesive sheets obtained in Examples 1 to 16 and Comparative Examples 1 to 2 were cut into 100 mm × 25 mm sizes, and the peeling film was peeled off and then attached to a glass plate. The 180° peeling strength (unit: N/25 mm) was measured at 23°C and a tensile speed of 300 mm/min using a tensile tester as the initial adhesion. The measurement was performed on 5 samples, and the average value is shown in Table 3. When used as a surface protection sheet, the peeling strength is preferably in the range of 0.01 to 0.03 N/25 mm from the perspective of no floating and easy peeling.

(2) Method for measuring adhesion after heat resistance test The adhesive sheets obtained in Examples 1 to 16 and Comparative Examples 1 to 2 were cut into 100 mm × 25 mm sizes, and the peeling films were removed and then attached to a glass plate. The sheets were then placed in a constant temperature chamber at 85°C for 7 days. After that, the sheets were temperature-controlled in a 50% RH, 23°C temperature-controlled room for 4 hours. The 180° peel strength (unit: N/25 mm) was measured at 23°C and a tensile speed of 300 mm/min using a tensile testing machine as the adhesion after heat resistance test. The measurement was performed on 5 samples, and the average value is shown in Table 3. The peel strength after the heat test is preferably in the range of 0.01 to 0.05 N/25 mm, and more preferably in the range of 0.01 to 0.04 N/25 mm. Furthermore, the variation of the peel strength after the heat test relative to the initial adhesion is preferably 0.025 N/25 mm or less.

(3) Method for measuring cutting properties The peeling film was removed from the adhesive sheet obtained from Examples 1 to 16 and Comparative Examples 1 to 2, and the blade of a cutter was placed against the adhesive surface to quickly cut a notch. The cut surface after cutting was visually observed through a magnifying glass, and the cutting properties were evaluated according to the following criteria. The results are shown in Table 3. Since chips generated during processing can contaminate the adherend and reduce performance, it is better not to generate chips. <Evaluation criteria> ◎ : The cut surface is smooth and no chips are generated. ○ : Although the cut surface is not smooth, no chips are generated. △ : The cut surface is not smooth and chips are generated. × : The cut surface is not smooth and chips are generated and scattered around.

(4) Evaluation method of substrate adhesion The peeling film was removed from the adhesive sheets obtained from Examples 1 to 16 and Comparative Examples 1 to 2, and each adhesive surface was rubbed 10 times with a fingernail to visually confirm whether the surface of the adhesive layer was peeled off from the polyethylene terephthalate film of the substrate, and the evaluation was performed according to the following criteria. The results are shown in Table 3. <Evaluation criteria> ◎: No whitening and no peeling. ○: Although it did not peel off, it was whitening. △: It peeled off after 6 to 10 rubbings. ×: It peeled off after 1 to 5 rubbings.

(5) Determination method of breaking strength and breaking elongation The peeling film and OPP film were peeled off from the adhesive cured products obtained in Examples 1 to 16 and Comparative Examples 1 to 2 to prepare dumb bell-shaped No. 3 test pieces. The breaking strength and breaking elongation of the test pieces were measured using a tensile testing machine at 23°C and 50% RH at a tensile speed of 100 mm/min. The measurement was performed on 5 test pieces, and the average value was calculated. The breaking strength and breaking elongation were evaluated according to the following criteria. The results are shown in Table 3. <Evaluation criteria for breaking strength> ◎: 2.0 MPa or more. ○: 1.0 MPa or more, but less than 2.0 MPa. △: 0.5MPa or more, less than 1.0MPa. ×: less than 0.5MPa. <Evaluation criteria for elongation at break> ◎: 100% or more. ○: 75% or more, less than 100%. △: 50% or more, less than 75%. ×: less than 50%.

(6) Evaluation method of yield The adhesive sheets obtained in Examples 1 to 16 and Comparative Examples 1 to 2 were cut into 100 mm × 25 mm sizes to prepare test pieces. After the peeling film was removed, one end of the test piece (5 mm × 25 mm) was bonded to the glass plate and fixed so that it would not peel off. Then, the 95 mm × 25 mm portion that was not bonded to the glass plate was vertically suspended from the glass plate by the short side of the test piece. Then, the suspended test piece was released, and the time until the entire test piece was bonded to the surface of the glass plate was measured. The measurement was performed on 5 test pieces, and the average value was calculated. The yield was evaluated based on the following criteria. The results are shown in Table 3. The shorter the time until bonding, the more difficult it is to mix bubbles during bonding, and the better the yield. <Evaluation criteria> ◎: Less than 2.0 seconds. ○: 2.0 seconds or more, less than 4.0 seconds. △: More than 4.0 seconds, less than 8.0 seconds. ×    ：More than 8.0 seconds.

(7) Evaluation method of gel fraction The cured adhesive obtained from Examples 1 to 16 and Comparative Examples 1 to 2 was cut into a size of about 70 mm × about 70 mm, and after removing the release film and OPP film, it was folded into four pieces to make a test piece of about 35 mm × about 35 mm. In addition, a SUS mesh with a pore size of 77 μm was cut into 150 mm × 150 mm, formed into a drawstring bag shape, and the open part was fixed with a metal wire to make a packaging material. After measuring the weight of the packaging material (W1), the metal wire was opened, the test piece was placed in it, and the weight was measured again (W2), and it was placed in a glass bottle and immersed in 100 mL of ethyl acetate. After standing at 25°C for 24 hours, the adhesive was taken out from ethyl acetate and dried in a dryer at 130°C for 90 minutes. The weight (W3) was measured and the gel fraction calculated by the following formula (1) was evaluated using the following criteria. The results are shown in Table 3. The higher the gel fraction, the more the adhesive can be cured to a practical level in a short time. Gel fraction (weight %) = (W3-W1) / (W2-W1) × 100 (1) <Evaluation criteria> ◎: 90% or more. ○: 70% or more, less than 90%. △: 50% or more, less than 70%. ×: less than 50%.

[table 3] Embodiment Comparison Example 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 2 Main agent (P-1) 100 - - - - - - - - - - - - - - - - - (P-2) - 100 - - - - - - - - - - - - - - - - (P-3) - - 100 - - - - - - - - - - - - - - - (P-4) - - - 100 - - - - - - - - - - - - - - (P-5) - - - - 100 - - - - - - - - - - - - - (P-6) - - - - - 100 - - - - - - - - - - - - (P-7) - - - - - - 100 - - - - - - - - - - - (P-8) - - - - - - - 100 - - - - - - - - - - (P-9) - - - - - - - - 100 - - - - - - - - - (P-10) - - - - - - - - - 100 - - - - - - - - (P-11) - - - - - - - - - - 100 - - - - - - - (P-12) - - - - - - - - - - - 100 - - - - - - (P-13) - - - - - - - - - - - - 100 - - - - - (P-14) - - - - - - - - - - - - - 100 - - - - (P-15) - - - - - - - - - - - - - - 100 - - - (P-16) - - - - - - - - - - - - - - - 100 - - (P'-1) - - - - - - - - - - - - - - - - 100 - (P'-2) - - - - - - - - - - - - - - - - - 100 Hardener (D-1) 5.1 5.0 5.1 4.9 3.7 3.1 5.1 - - - - - 8.1 3.1 4.8 - 2.7 - (D-2) - - - - - - - 3.2 5.8 9.5 9.7 4.1 - - - 6.0 - 0.85 Solvent Ethyl acetate 40 40 40 40 40 40 40 64 98 66 66 98 52 40 40 98 40 35 Amine esterification catalyst Dibutyltin dilaurate 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 0.008 - - 0.008 0.008 0.008 0.008 0.008 0.008 0.008 Borchi Kat22 - - - - - - - - - 0.30 0.30 - - - - - - - Isocyanate equivalent weight/Hydroxy equivalent weight 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 Initial adhesion (N/25mm) 0.017 0.021 0.015 0.020 0.014 0.011 0.018 0.024 0.016 0.013 0.018 0.017 0.019 0.036 0.019 0.019 0.051 0.012 Adhesion after heat resistance test (N/25mm) 0.039 0.039 0.036 0.038 0.015 0.016 0.037 0.027 0.023 0.034 0.032 0.037 0.042 0.051 0.035 0.028 0.078 0.034 Adhesion force change after heat resistance test (N/25mm) 0.022 0.018 0.021 0.018 0.001 0.005 0.019 0.003 0.007 0.021 0.014 0.020 0.023 0.015 0.016 0.009 0.027 0.022 Cutting ◎ ○ ○ ◎ ○ ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ ○ ◎ ◎ △ △ Adhesion to substrate ○ ◎ ◎ ◎ ◎ ◎ ○ ◎ ◎ ◎ ◎ ◎ ○ ◎ ○ ◎ △ △ Breaking strength ○ ○ ◎ ◎ ◎ ◎ ○ ◎ ◎ ◎ ○ ◎ ◎ ◎ ◎ ◎ △ ○ Elongation at break ◎ ◎ ◎ ◎ ○ ○ ◎ ○ ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ ○ × Yield ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ ◎ ○ ○ ◎ ◎ ◎ ○ × Gel fraction ◎ ○ ○ ○ ○ ○ ○ ◎ ◎ ◎ ◎ ◎ ◎ ○ ◎ ◎ ○ △ [Industrial Availability]

The main agent for the two-component curable urethane adhesive of the present invention and the two-component curable urethane adhesive using the same can be used for a wide range of purposes such as protecting optical components in the manufacturing steps of image display devices such as polarizing plates or attaching optical components to each other, and are extremely useful.

without

without

Claims (7)

A two-component curable urethane adhesive comprises a main agent and a curing agent, wherein the main agent comprises an urethane resin (P) having a hydroxyl group formed by reacting a polyol component (a) with an urethane prepolymer (b) having an isocyanate group, the polyol component (a) comprises a multifunctional polyoxyalkylene polyol (a1) having a hydroxyl value of 10 to 350 mgKOH/g, the multifunctional polyoxyalkylene polyol (a1) being a polyoxyalkylene polyol (a11) having a hydroxypropyl group at the molecular end represented by the general formula (1) and/or an ethylene oxide adduct (a12) thereof, the urethane prepolymer (b) being a compound represented by the general formula (6), and the curing agent comprising a crosslinking agent (D) having an isocyanate group.

[In the general formula (1), X is an m-valent residue obtained by removing all active hydrogen atoms from a compound having m active hydrogen atoms; A is an alkylene group having 2 to 12 carbon atoms which may be substituted by a phenyl group, a halogenphenyl group or a halogen atom; Z is a propylene group; m is an integer of 4 to 10; p is an integer of 0 to 199; q is an integer of 1 to 200, and 1≦p+q≦200]OCN-[LU-(CHR-CHR-CHR-CHR-O) _b -U] _s -L-NCO (6) [In the general formula (6), L is a divalent group obtained by removing an isocyanate group from a polyisocyanate component (bp); U represents an amine ester bond; R is independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; b is an integer of 20 to 70; and the average value of s is 1.01 to 10]. As in claim 1, the two-component curing amine adhesive, wherein the amine prepolymer (b) is bifunctional, and the isocyanate content based on the weight of the amine prepolymer (b) is 0.1-12% by weight. The two-component curable urethane adhesive of claim 1 or 2, wherein the polyfunctional polyoxyalkylene polyol (a1) is a polyol having a group represented by the general formula (2) and/or a group represented by the general formula (3) at a molecular end, and the ratio of the number of groups represented by the general formula (2) possessed by the polyfunctional polyoxyalkylene polyol (a1) is 40% or more, based on the total number of groups represented by the general formula (2) and the number of groups represented by the general formula (3) possessed by the polyfunctional polyoxyalkylene polyol (a1),

[In general formulas (2) and (3), a is each independently an integer greater than or equal to 0]. As in claim 1 or 2 of the two-component curable urethane adhesive, wherein the multifunctional polyoxyalkylene polyol (a1) is an alkylene oxide adduct of sorbitol, the alkylene oxide comprises propylene oxide, and the addition molar number of the propylene oxide is 50-200. For example, the two-component curing urethane adhesive of claim 1 or 2, wherein the weight average molecular weight of the urethane resin (P) is 10,000~500,000. A cured product of a two-component curable urethane adhesive, wherein the two-component curable urethane adhesive is a two-component curable urethane adhesive of any one of claim items 1 to 5. An urethane adhesive sheet is made using a two-component curing urethane adhesive according to any one of claim items 1 to 5.