Peelable pressure-sensitive adhesive composition, peelable pressure-sensitive adhesive, peelable pressure-sensitive adhesive sheet, pressure-sensitive adhesive composition, pressure-

Abstract

To provide a peelable pressure-sensitive adhesive composition capable of forming a peelable pressure-sensitive adhesive which is used for sticking a pressure-sensitive adhesive sheet and an adherend to each other on the assumption that the pressure-sensitive adhesive sheet and the adherend once stuck to each other are peeled from each other and which can prevent the pressure-sensitive adhesive sheet from being broken when the pressure-sensitive adhesive sheet is peeled.SOLUTION: The peelable adhesive composition comprises an adhesive resin (A) and a compound (B) containing an ethylenically unsaturated group and an isocyanate group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a peelable pressure-sensitive adhesive composition, and more particularly to a peelable pressure-sensitive adhesive composition used in semiconductor processing sheets. A release adhesive composition, more specifically, used by being attached to the surface of a semiconductor wafer during wafer back grinding. The present invention relates to a releasable pressure-sensitive adhesive composition for use in a backgrind sheet. [Background technology]

[0002] As information terminal devices become thinner, smaller, and more multifunctional, the semiconductors they incorporate are becoming increasingly Similarly, devices are also required to be thinner and more dense. There is also a demand for thinner integrated semiconductor wafers, and for this reason, may be ground and thinned. In addition, bumps (electrodes) made of solder or the like are formed on the wafer surface, and the surface has unevenness. When such a semiconductor wafer with bumps is subjected to back grinding, the bumps are often A semiconductor processing sheet is attached to the wafer surface to protect the surface containing semiconductor particles. Conventionally, the processing sheet has been provided with a substrate and a pressure-sensitive adhesive layer provided on one side of the substrate. Generally, an adhesive sheet is used.

[0003] The semiconductor processing sheet is designed to adequately protect bumps and other irregularities on the wafer surface. Therefore, the ability to embed bumps and conform to steps is required. If adhesive from the semiconductor processing sheet remains on the uneven surface, the adhesive residue can cause defects in the semiconductor device. Therefore, for example, in Patent Document 1, while improving the step-following ability, In order to prevent adhesive residue from remaining on uneven areas, an intermediate layer is placed on the substrate of the semiconductor processing sheet. and a pressure-sensitive adhesive layer, and the intermediate layer and the pressure-sensitive adhesive layer are formed from a specific acrylic polymer. It has been disclosed. In addition, Patent Document 2 describes an acrylic resin that is often used as a base resin for adhesives. A polyester resin was used instead of the above, and a resin composition containing an unsaturated group-containing compound was further blended. A pressure-sensitive adhesive has been proposed which contains a crosslinking agent and is crosslinked by irradiating with ultraviolet light. Such adhesives are cured by crosslinking under ultraviolet irradiation, and the adhesive strength is reduced, and when peeled off, This improves the releasability. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2015 / 111310 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-221249 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, semiconductor devices have become increasingly finer, and as a result, minute grooves are being added to the uneven parts. When peeling off the adhesive sheet, the adhesive sheet breaks and adhesive remains. This is becoming a problem.

[0006] The adhesive sheet of Patent Document 1 has an intermediate layer between the substrate and the adhesive layer to improve embedding properties. When peeling off the adhesive layer, there is a risk of peeling between the intermediate layer and the adhesive layer. In addition, the provision of an intermediate layer makes the preparation of the adhesive sheet complicated, so There is a need for an adhesive layer that can function as both an intermediate layer and an adhesive layer.

[0007] Furthermore, the adhesive sheets described in Patent Documents 1 and 2 have good embedding properties for bumps. It is possible to reduce adhesive residue while improving adhesion, but it is not possible to break the adhesive sheet. In other words, the pressure-sensitive adhesive sheets described in Patent Documents 1 and 2 have the following problems: If the adherend is flat, adhesive residue can be reduced, but if bumps or other surfaces are embedded, In this case, part of the adhesive layer is physically caught on the uneven surface, causing it to break and remain as adhesive residue. In particular, if the adhesive sheet has low elongation, Because it does not stretch, it tears easily, which can lead to the problem of adhesive residue.

[0008] Therefore, in the present invention, under such circumstances, the adhesive sheet and the adherend that have been bonded together are It is an adhesive used for bonding purposes with the assumption that it will be peeled off, and A peelable adhesive that can prevent the adhesive sheet from breaking when the adhesive sheet is released, and a method for peeling the adhesive sheet The present invention provides a releasable pressure-sensitive adhesive composition capable of forming an adhesive, and a releasable pressure-sensitive adhesive sheet. The present invention also provides a pressure-sensitive adhesive composition, a pressure-sensitive adhesive, and a pressure-sensitive adhesive sheet. be. [Means for solving the problem]

[0009] However, the present inventors have conducted extensive research in light of the above circumstances, and as a result, have discovered a method for producing a tacky resin and an ethyl alcohol. A peelable adhesive composition containing a compound having a carboxylic unsaturated group and an isocyanate group is used. The adhesive was found to have a moderate adhesive strength that allowed it to be peeled off, and also to have high elongation. The present invention has been completed.

[0010] That is, the present invention provides the following [1] to

[12] . [1] An adhesive resin (A) and a compound containing an ethylenically unsaturated group and an isocyanate group (B). [2] The peelable pressure-sensitive adhesive according to [1], wherein the pressure-sensitive adhesive resin (A) is a polyester resin. composition. [3] The adhesive resin (A) is a polyester resin having a weight average molecular weight of 10,000 or more. The peelable pressure-sensitive adhesive composition according to [1] or [2], wherein [4] The compound (B) containing an ethylenically unsaturated group and an isocyanate group is two or more The peelable pressure-sensitive adhesive composition according to any one of [1] to [3] above, which contains an isocyanate group. . [5] The content of the compound (B) containing an ethylenically unsaturated group and an isocyanate group is 0.1 to 50 parts by weight of [1] to [4] relative to 100 parts by weight of the adhesive resin (A). The peelable pressure-sensitive adhesive composition according to any one of the preceding claims. [6] The peelable adhesive according to any one of [1] to [5], further comprising a polymerization initiator (C). Adhesive composition. [7] A peelable adhesive comprising the peelable adhesive composition according to any one of [1] to [6]. Agent. [8] At least one adhesive layer containing the releasable adhesive according to [7] is laminated on a substrate. A peelable adhesive sheet. [9] The adhesive strength (β) of the peelable adhesive sheet is 2N / 25mm or less. [8] The peelable adhesive sheet according to [8]. Adhesion strength (β): The peelable adhesive sheet is attached to the SUS-BA plate as the adherend, and the temperature is 23°C, 5 After leaving the sample at 0%RH for 30 minutes or more, it was irradiated with ultraviolet light (500mJ / cm² using a high-pressure mercury lamp). m 2 ) and then measured according to JIS Z0237, the 180 degree peak after ultraviolet irradiation Strength (N / 25mm)

[10] Polyester resin and ethylene unsaturated group and two or more isocyanate groups A pressure-sensitive adhesive composition containing the compound (B1).

[11] A pressure-sensitive adhesive obtained by using the pressure-sensitive adhesive composition according to

[10] .

[12] At least one adhesive layer containing the adhesive according to

[11] is laminated on a substrate. Adhesive sheet.

[0011] Conventionally, by adding unsaturated groups to adhesive resins, the initial adhesive strength is high and the adhesive strength is high when exposed to ultraviolet light. The most common method was to make the adhesive stronger so that it could be peeled off. However, this method was not effective because it was resistant to ultraviolet light. Since the unsaturated group components corresponding to the adhesive resin are randomly present in the adhesive resin, after ultraviolet irradiation, A network of unsaturated groups is formed throughout the material, which tends to result in a lack of elongation overall. There is a problem. Alternatively, a method other than the above may be used in which a pressure-sensitive adhesive resin having no unsaturated groups and a pressure-sensitive adhesive resin having an unsaturated group are mixed. There is also a method of blending multifunctional acrylates or multifunctional urethane acrylates, but this method The adhesive resin is chemically bonded to the network of unsaturated groups that is formed after UV irradiation. Therefore, there was a problem that adhesive residue was likely to remain after peeling. In the present invention, the functional group of the adhesive resin, which is the main component, reacts with the functional group of the adhesive resin to form an integrated structure. By forming a network with the unsaturated group-containing compound, the cross-linking points after UV irradiation The molecular weight becomes large, and the adhesive resin does not have an unsaturated group, so the entire adhesive resin is easy to stretch. This makes it easier to apply and less likely to leave adhesive residue. [Effects of the Invention]

[0012] The releasable pressure-sensitive adhesive composition of the present invention has adhesive strength that allows re-peelability when used as a releasable pressure-sensitive adhesive. Therefore, the above-mentioned peelable adhesive can be used in an energy-efficient manner. After adding energy, the adhesive strength becomes low and it can be easily peeled off. Even when the adhesive gets physically caught on uneven surfaces, it does not break and adhesive residue is less likely to remain. Furthermore, because of its high elongation, it can be easily attached by applying heat and pressure as needed. At times, it is easier to follow uneven surfaces. That is, the peelable pressure-sensitive adhesive composition of the present invention has low adhesive strength after application of energy and low elongation. This results in a high adhesive, which has excellent peelability, reduced adhesive residue, and unevenness conformability. do.

[0013] The pressure-sensitive adhesive composition of the present invention may be any of the above-mentioned peelable pressure-sensitive adhesive compositions, and may also be any of the above-mentioned compositions for the purpose of peeling. It can also be used in a pressure-sensitive adhesive composition that does not require a peelable adhesive. The adhesive has low adhesive strength and high elongation after energy application, and This reduces adhesive residue and provides excellent step-following properties. DETAILED DESCRIPTION OF THE INVENTION

[0014] The configuration of the present invention will be described in detail below, but these are examples of preferred embodiments. It is something. In the present invention, "(meth)acrylic" refers to acrylic or methacrylic, "(Meth)acryloyl" refers to acryloyl or methacryloyl, and "(meth)acryloyl" refers to "Acrylate" means acrylate or methacrylate, respectively. Furthermore, in the present invention, "x and / or y (x and y are any constitutions or components)" means three combinations: x only, y only, and x and y.

[0015] <Releasable Pressure-Sensitive Adhesive Composition> First, a peelable pressure-sensitive adhesive composition according to one embodiment of the present invention (hereinafter referred to as "the peelable pressure-sensitive adhesive composition") will be described. ") will be explained. The present peelable pressure-sensitive adhesive composition comprises a pressure-sensitive adhesive resin (A) and a compound having an ethylenically unsaturated group and an isocyanate. The compound (B) containing a group (hereinafter referred to as "compound (B)") may be optionally polymerized. It may also contain a polymerization initiator (C), a hydrolysis inhibitor (D), and the like.

[0016] <Adhesive resin (A)> The adhesive resin (A) may be any resin that is generally used as an adhesive. Not limited to.

[0017] The glass transition temperature of the adhesive resin (A) is usually 20°C or lower, preferably 0°C or lower. It is preferable that the glass transition temperature has tackiness at room temperature. °C.

[0018] In addition, the adhesive resin (A) is preferably a resin having a hydroxyl group in terms of reactivity with the compound (B). It is preferable that the main chain end is a polymer because the molecular weight between crosslinking points is large and the elongation is high. A resin having a hydroxyl group is more preferred.

[0019] Examples of the adhesive resin (A) include acrylic resins, rubber resins, and polyester resins. Examples of suitable resins include (A1), urethane resins, and silicone resins. The polyester resin (A1) is preferred because it has excellent elongation after curing and adhesive properties.

[0020] [Polyester resin (A1)] The polyester resin (A1) used in the present peelable pressure-sensitive adhesive composition is Any known polyester resin may be used. Conventionally, when a polyester resin is used as a peelable adhesive, the polyester resin has the following characteristics: Usually, functional groups are only present at the ends of molecules, so By reacting a compound having a functional group and an unsaturated group corresponding to the functional group, a high concentration of unsaturated groups can be obtained. Therefore, when the content of unsaturated groups in polyester resins is increased, In order to achieve this, it is necessary to increase the functional groups at the terminals, which reduces the molecular weight. There is a concern that the adhesive residue will increase when it is used as an adhesive. When incorporating a basic group or using a polyester resin as a reaction point with a crosslinking agent, The number of functional groups in the polyester resin tends to be insufficient, Grease was thought to be unsuitable for applications such as peel-off adhesives. Therefore, in the peelable pressure-sensitive adhesive sheet using polyester resin, It was thought that this design would be difficult to achieve without adding organic compounds. By using the compound (B) described below, the terminal functional group of the polyester resin is It could only react with isocyanates of Therefore, even when polyester resin with few functional groups (hydroxyl groups) is used, sufficient ink is obtained. It was possible to crosslink the hydroxyl groups and to give the unsaturated groups. The functional group (hydroxyl group) of steric resins is located at the end of the molecule, which increases the molecular weight between crosslink points. This allows for a highly stretchable adhesive.

[0021] The polyester resin (A1) contains a structural unit derived from a dicarboxylic acid, a structural unit derived from a diol, and a It has structural units derived from trivalent or higher polycarboxylic acids as required. and / or a structural unit derived from a trihydric or higher polyhydric alcohol. The base resin (A1) is a compound containing a polycarboxylic acid such as a dicarboxylic acid or a polycarboxylic acid having three or more carboxylic acids and a dicarboxylic acid. The polymerization component includes a polyol, a polyhydric alcohol such as a trihydric or higher polyhydric alcohol, and the like. This is obtained by:

[0022] [Structural units derived from dicarboxylic acids] Examples of the structural unit derived from a dicarboxylic acid in the polyester resin (A1) include For example, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, Pimelic acid, decanedicarboxylic acid, octadecanedicarboxylic acid, 1,12-dodecanoic acid aliphatic acyclic dicarboxylic acids such as 1,14-tetradecanoic acid and hydrogenated dimer acids, 1,2- Cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexane cyclohexanedicarboxylic acid, 1,2-cyclohexanediacetic acid, 1,3-cyclohexanediacetic acid, 1,4-Cyclohexanediacetic acid, tetrahydrophthalic acid, tetrachlorophthalic acid, hexa Aliphatic cyclic dicarboxylic acids such as hydrophthalic acid, fumaric acid, maleic acid, itaconic acid, da Aliphatic unsaturated dicarboxylic acids such as mer acid, terephthalic acid, isophthalic acid, orthophthalic acid Benzenedicarboxylic acids such as 1,5-naphthalenedicarboxylic acid and 2,6-naphthalenedicarboxylic acid carboxylic acid, 4,4'-biphenyldicarboxylic acid, furandicarboxylic acid, thiophenedicarboxylic acid carboxylic acids (pyrrole, pyrazole, imidazole, pyridine, pyridazine, pyrimidine, Aromatic dicarboxylic acids such as heterocyclic dicarboxylic acids (e.g., pyrazine) and their acid anhydrides Examples of the structural units include those derived from dicarboxylic acids and lower alkyl esters. The polyester resin (A1) may contain one or more types of acid-derived structural units. Good too. Among these, structural units derived from aromatic dicarboxylic acids and structural units derived from aliphatic acyclic dicarboxylic acids are particularly It is preferable that the polymer has the following structural unit, and in particular, from the viewpoint of achieving both durability and flexibility, It has both structural units derived from aromatic dicarboxylic acids and structural units derived from aliphatic acyclic dicarboxylic acids. It is more preferable to use a structural unit derived from isophthalic acid and a structural unit derived from sebacic acid. It is preferred to have both units.

[0023] When the polyester resin (A1) has a structural unit derived from an aromatic dicarboxylic acid, The content of the structural unit derived from the polycarboxylic acid is preferably 5 to 75 mol %, and more preferably It is more preferable that the content is 10 to 30 mol %. If the content is too small, the heat resistance may be poor. If the amount is too large, the flexibility will be lost, the initial adhesiveness will decrease, and There is a tendency for pressure equivalent to finger pressure to not be able to exert sufficient adhesive strength.

[0024] In addition, the polyester resin (A1) has a structural unit derived from an aliphatic acyclic dicarboxylic acid. In this case, the content of the structural units derived from polycarboxylic acids is 25 to 95 mol %. It is preferable that the content is 70 to 90 mol %. When energy is applied, the flexibility is lost and the initial adhesiveness (adhesion before energy is applied) decreases, and pressure equivalent to that of finger pressure is applied. If the adhesive strength is too high, it will tend to be unable to exert sufficient adhesive force, and if there is too much, the heat resistance and mechanical strength will decrease. There is a tendency to

[0025] In addition, the polyester resin (A1) contains a structural unit derived from an aromatic dicarboxylic acid and a structural unit derived from an aliphatic non- When a structural unit derived from a cyclic dicarboxylic acid is contained, a structural unit derived from an aromatic dicarboxylic acid (monomer) is also contained. The ratio of the structural units (mol%) derived from aliphatic acyclic dicarboxylic acids to the structural units (mol%) derived from aliphatic acyclic dicarboxylic acids is From the viewpoint of balance of mechanical strength, it is preferably 0.1 to 50, and more preferably 1 to 25. It is more preferable that the number of carbon atoms is 2 to 10, and particularly preferable that the number of carbon atoms is 2 to 10.

[0026] [Diol-derived structural units] Examples of the diol-derived structural unit in the polyester resin (A1) include: Ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol 1,6-Hexanediol, 1,8-Octanediol, 1,9-Nonaphthalene Straight-chain fats such as decanediol, 1,10-decanediol, and 1,18-octadecanediol Aromatic diol, propylene glycol, neopentyl glycol, 2-methyl-1,3-propanediol propanediol, 1-methyl-1,3-propanediol, 2-methyl-2-ethyl-1 ,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-methyl- 2-Propyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propane Diol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol 2,4-diethyl-1,5-pentanediol, 1,3,5-trimethyl-1,3 -pentanediol, 2-methyl-1,6-hexanediol, 2-methyl-1,8-hexanediol 2-Methyl-1,9-nonanediol, Dimer diol, 4-methyl -1,7-heptanediol, 3-methyl-1,6-hexanediol, 1-methyl-1 ,6-Hexanediol, 4-Methyl-1,9-nonanediol, 3-Methyl-1,9- Aliphatic diols with hydrocarbon groups in the side chain, such as nonanediol, 1,4-cyclohexane Diol, 1,4-cyclohexanedimethanol, 1,3-cyclobutanediol, hydrogenated Bisphenol A and / or its ethylene oxide adducts and propionate adducts Alicyclic diol, bisphenol A, 9,9-bis(hydroxyphenyl)fluorene , 4,4'-thiodiphenol, 4,4'-methylenediphenol, 4,4'-dihydro Dihydroxybiphenyl, o-, m-, and p-dihydroxybenzene, 2,5-naphthalene ol, p-xylenediol, and their ethylene oxide adducts and propylene Examples of structural units derived from aromatic diols include oxide adducts. The above structural units may be contained alone or in combination of two or more in the polyester resin (A1). good. Among these, linear polymers are preferred because the glass transition temperature can be controlled to prevent crystallization. A structural unit derived from an aliphatic diol and a structural unit derived from an aliphatic diol having a hydrocarbon group in the side chain It is particularly preferable that the structural unit derived from the linear aliphatic diol has both ethyl and methyl groups. at least one selected from the group consisting of ethylene glycol, 1,4-butanediol, and 1,6-hexanediol; structural units derived from at least one type of aliphatic diol and structural units derived from an aliphatic diol having a hydrocarbon group in the side chain Derived from neopentyl glycol and 2-butyl-2-ethyl-1,3-propanediol It is particularly preferable that the compound has at least one structural unit selected from the following structural units: .

[0027] Furthermore, the diol-derived structural unit can easily give a polymer of the desired molecular weight. For this purpose, a structural unit derived from a polyester diol, a structural unit derived from a polyether diol, Structural units derived from polycaprolactone diol, structural units derived from polycarbonate diol etc.

[0028] Examples of the structural unit derived from the polyester diol include ethylene glycol, diol, and the like. Ethylene glycol, 1,4-butanediol, neopentyl glycol, 3-methyl- 1,5-Pentanediol, 2-Butyl-2-ethyl-1,3-propanediol, 2, 4-Diethyl-1,5-pentanediol, 1,8-octanediol, 1,9-nonane Diol, 2-methyl-1,8-octanediol, 1,10-decanediol, octa Diol components such as decanediol, succinic acid, methylsuccinic acid, adipic acid, pimelic acid Citric acid, azelaic acid, sebacic acid, 1,12-dodecanoic acid, 1,14-tetradecanedioic acid , terephthalic acid, isophthalic acid, or their acid anhydrides or lower alkyl esters The carboxylic acid component or its derivatives are dehydrated either alone or in a mixture. Examples of such structural units include structural units derived from polyester diols. Commercially available polyester diols that can be used to introduce into the ester resin (A1) include: For example, polyester diol of 3-methyl-1,5-pentanediol and adipic acid The product names are "Kuraray Polyol P-510", "Kuraray Polyol P-1010", Kuraray Polyol P-2010, Kuraray Polyol P-3010, Kuraray Polyol Examples include "Kuraray P-5010" [all manufactured by Kuraray Co., Ltd.].

[0029] Examples of the structural unit derived from the polyether diol include ethylene oxide, Polyethylene glycol obtained by ring-opening polymerization of propylene oxide, tetrahydrofuran, etc. Polypropylene glycol, polytetramethylene glycol, and copolymers thereof Examples of such structural units include those derived from copolyethers. Commercially available polyether diols used for introducing into (A1) include, for example, Pro A polyether diol made by adding propylene oxide to propylene glycol. Name: "ADEKA Polyether P-400", "ADEKA Polyether P-1000", "ADEKA Polyether P-2000" and "Adeka Polyether P-3000" [both Asahi Denka Kogyo Examples include:

[0030] Examples of the structural unit derived from the polycaprolactone diol include ε-caprolactone. Caprolactone obtained by ring-opening polymerization of cyclic ester monomers such as valerolactone and δ-valerolactone. Examples of such structural units include those derived from polyester diols. The commercially available polycaprolactone diol used for introducing into the ester resin (A1) is For example, the product names are "Plaxel L205AL," "Plaxel L212AL," and "Plaxel L212AL." Plaxel L220AL, Plaxel L220PL, Plaxel L230AL The above are manufactured by Daicel Chemical Industries, Ltd.

[0031] Examples of the structural unit derived from the polycarbonate diol include propylene carbonate, Hexamethylene carbonate diol, hexamethylene carbonate diol, 3-methylpentene carbonate Carbonate diols such as diols, ethylene glycol, 1,3-propylene glycol 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol Polyhydric alcohols such as tandiol and 1,9-nonanediol and diethylene carbonate, Poly(ethylene glycol) obtained by dealcoholization reaction with dialkyl carbonate such as dimethyl carbonate Examples of such structural units include those derived from dicarbonate diols. Commercially available polycarbonate diols that can be used to introduce into the resin (A1) include: For example, product names "PLACCEL CD205", "PLACCEL CD210", "PLACCEL CD220", "PLACCEL CD205PL", "PLACCE L CD210PL", "PLACCEL CD220PL" [Daicel Chemical Industries, Ltd. Examples include:

[0032] When the polyester resin (A1) has a structural unit derived from a linear aliphatic diol, In this case, the content thereof is preferably 5 to 40 mol % of the structural units derived from polyhydric alcohol. It is more preferable that the content is 10 to 30 mol %. If the content is too high, crystallization tends to occur and adhesive properties deteriorate. There tends to be a lack of sex.

[0033] In addition, the polyester resin (A1) is a diol-derived copolymer having a hydrocarbon group in the side chain. When the polyol has the structural unit, the content is 3 to 100 units of the structural unit derived from polyhydric alcohol. It is preferable that the content is 10 to 70 mol %, and more preferably 10 to 70 mol %. If the content is too low, crystallization occurs and tack tends to be easily lost.

[0034] The polyester resin (A1) has a structure unit derived from a linear aliphatic diol and a carbonized structure in the side chain. When the structural unit is derived from an aliphatic diol having a hydrogen group, the structural unit is derived from a linear aliphatic diol. The structural units (mol%) derived from aliphatic diols having hydrocarbon groups in the side chains ( The ratio of mol % is preferably 0.1 to 100 from the viewpoint of preventing crystallinity from being exhibited. It is more preferable that the ratio is 0.5 to 20, and particularly preferably 1 to 5.

[0035] [Structural units derived from trivalent or higher polycarboxylic acids] In the polyester resin (A1), the structure derived from a trivalent or higher polyvalent carboxylic acid Examples of structural units include aromatic polysaccharides such as trimellitic acid, trimesic acid, and pyromellitic acid. carboxylic acids, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid Acid 1,2,4-cyclohexanetricarboxylic acid, 1,2,3,4-butanetetracarboxylic acid aliphatic polycarboxylic acids such as carboxylic acids, and their acid anhydrides and lower alkyl esters The structural units derived from these trivalent or higher polyvalent carboxylic acids include: The polyester resin (A1) may contain one or more of these. Among these, trivalent polycarboxylic acids are preferred from the viewpoint of appropriately controlling the degree of dispersion. It is preferable that the compound has a structural unit derived from a trivalent aromatic carboxylic acid, and particularly a structural unit derived from a trivalent aromatic carboxylic acid. is preferred, and it is particularly preferred that the copolymer has a structural unit derived from trimellitic acid.

[0036] When the polyester resin (A1) has a structural unit derived from a trivalent or higher polycarboxylic acid, In this case, the content of the structural unit derived from the polycarboxylic acid is preferably 0.1 to 5 mol %. It is preferable from the viewpoint of durability before energy is applied when used as a binder, and further, it is preferable to use a binder containing 0.1 to 2.5 mol %, and 0.2 to 2 mol % is particularly preferred. If the amount is too small, the durability of the adhesive before energy application tends to decrease. If the amount is too large, gelation occurs and adhesive strength tends to decrease.

[0037] [Structural units derived from trivalent or higher polyhydric alcohols] The structural unit derived from a trihydric or higher polyhydric alcohol in the polyester resin (A1), Examples of suitable solvents include trimethylolethane, trimethylolpropane, glycerin, and pentamethylolpropane. Erythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, 1 , 2,6-hexanetriol, pentaerythritol, dipentaerythritol, etc. Examples of structural units derived from aliphatic polyhydric alcohols include those derived from trihydric or higher polyhydric alcohols. The polyester resin (A1) may contain one or more of the following structural units. . Among these, trivalent aliphatic alcohols are preferred from the viewpoint of appropriately controlling the degree of dispersion. It is preferable that the copolymer has a structural unit derived from methylolpropane, and particularly preferable that the copolymer has a structural unit derived from trimethylolpropane. It is preferred that the aryl group has a position.

[0038] In addition, the polyester resin (A1) has a structural unit derived from a trihydric or higher polyhydric alcohol. If so, the content must be 0.1 to 5 mol% of the structural unit derived from polyhydric alcohol. is preferable from the viewpoint of durability before energy is applied when used as an adhesive, and more preferably 0.1 to 2. It is particularly preferably 5 mol %, and particularly preferably 0.2 to 2 mol %. If the content is too low, the durability of the adhesive before energy application tends to decrease. If the amount is too large, gelation occurs and adhesive strength tends to decrease.

[0039] The composition and composition ratio of the polyester resin (A1) are: 1 H-NMR measurements and 13 C-NMR It can be determined from the spectrum obtained by measurement.

[0040] [Production of polyester resin (A1)] The polyester resin (A1) used in the present peelable pressure-sensitive adhesive composition is Using carboxylic acid and the above-mentioned polyhydric alcohol as raw materials, a polycondensation reaction is carried out in the presence of a catalyst by a known method. That is, the polyester resin (A1) can be produced by Since it is obtained by polycondensation reaction of polycarboxylic acid and polyhydric alcohol, The resulting polymer has a structural unit derived from the polyhydric alcohol and a structural unit derived from the polyhydric alcohol. During the reaction, an esterification reaction or an ester exchange reaction is carried out first, followed by a polycondensation reaction. If it is not necessary to obtain a high molecular weight, an esterification reaction or It can also be produced by transtermination alone.

[0041] The blending ratio of the polycarboxylic acid and polyhydric alcohol is 1 equivalent of polycarboxylic acid. The amount of polyhydric alcohol is preferably 1 to 3 equivalents, and particularly preferably 1.1 to 2.2 equivalents. The blending ratio of the polyhydric alcohol is preferably 1.2 to 1.7 equivalents. If it is too low, the acid value will be high and it will be difficult to increase the molecular weight, and if it is too high, the yield will decrease. There is a tendency to

[0042] [Esterification reaction or transesterification reaction] In the esterification reaction or transesterification reaction, a catalyst is usually used. Examples of suitable titanium catalysts include tetraisopropyl titanate and tetrabutyl titanate. catalysts, antimony-based catalysts such as antimony trioxide, germanium-based catalysts such as germanium dioxide Examples of catalysts include catalysts such as zinc acetate, manganese acetate, and dibutyltin oxide. One or more of these can be used. Among these, those with high catalytic activity are preferred. From the balance between the color of the reaction product and the color of the resulting product, antimony trioxide, tetrabutyl titanate , germanium dioxide, and zinc acetate are preferred.

[0043] The amount of the catalyst to be blended is 1 to 10,000 ppm based on the total copolymerization components (by weight). It is particularly preferable that the concentration is 10 to 5000 ppm, and further preferably 20 to 300 If the blending amount is too small, the polymerization reaction tends to proceed insufficiently. If the amount is too large, there is no advantage such as shortening the reaction time, and side reactions tend to occur.

[0044] The reaction temperature during the esterification reaction or transesterification reaction is 200 to 300°C. is preferable, particularly preferably 210 to 280°C, and further preferably 220 to 260°C. If the reaction temperature is too low, the reaction tends not to proceed sufficiently, and if it is too high, decomposition and the like may occur. In addition, the reaction pressure is usually normal pressure, but in pressurized reactions, It is also preferable to increase the reaction temperature by reacting the catalyst with the catalyst in a manner that allows the reaction to proceed efficiently.

[0045] The polycondensation reaction carried out after the esterification reaction or transesterification reaction is The reaction conditions are the same as those used in the above esterification reaction or transesterification reaction. The catalyst is further added in an amount of about the same, and the reaction temperature is preferably 220 to 280°C, particularly preferably The reaction temperature is kept at 230-270°C, and the pressure in the reaction system is gradually reduced until the reaction is completed at 5 hPa or less. If the reaction temperature is too low, the reaction tends to proceed insufficiently. If the temperature is too high, side reactions such as decomposition tend to occur.

[0046] In producing the polyester resin (A1), the depolymerization reaction is carried out after the condensation reaction. This is also preferred because it allows the polyester resin (A1) to effectively contain functional groups. For depolymerization, the above-mentioned polycarboxylic acids and polyhydric alcohols can be used. It is preferable to use the above polyvalent carboxylic acids and / or trivalent or higher polyhydric alcohol components. Preferably, dicarboxylic acids and diols can be used as needed.

[0047] The polycarboxylic acids and polyhydric alcohols added during depolymerization should have a high hydroxyl group content. In view of this, diols or trihydric or higher polyhydric alcohols are preferred. In particular, trihydric or higher polyhydric alcohols are preferred because they can increase the hydroxyl group content. However, trimethylolpropane is preferred due to its versatility.

[0048] The temperature for depolymerization is usually 150 to 260°C, and the reaction time is usually 10 minutes to 3 hours. is.

[0049] The depolymerization is carried out to remove 10% of all polycarboxylic acids constituting the polyester resin (A1). When the depolymerization rate is 0 mol%, it is preferable to use 20 mol% or less of the depolymerization component, and more preferably Preferably 0.1 to 15 mol %, particularly preferably 0.5 to 10 mol %, further preferably 1 to It is 5 mol%.

[0050] By carrying out the reaction according to the above method, a polyester resin (A1) can be obtained. Cut.

[0051] The number average molecular weight (Mn) of the polyester resin (A1) is usually 5,000 or more. It is more preferable that the molecular weight is 8,000 to 100,000, and more preferably 10,000 to 80,000. If the number average molecular weight is too small, sufficient cohesive strength cannot be obtained as an adhesive. If the thickness is too large, the heat resistance and mechanical strength tend to decrease, and if the thickness is too large, flexibility is lost and the initial adhesiveness decreases. The adhesive strength decreases, and sufficient adhesive strength cannot be achieved with pressure equivalent to finger pressure.

[0052] The weight average molecular weight (Mw) of the polyester resin (A1) is 10,000 or more. It is preferable that the number of ions is 30,000 or more, and more preferable that the number of ions is 30,000 or more. If the weight average molecular weight is too small, the adhesive will not have sufficient cohesive strength. This can lead to a decrease in heat resistance and mechanical strength, and adhesive residue can easily remain when the film is peeled off. If it is too large, it will lose flexibility, the initial adhesiveness will decrease, and the pressure will be similar to that of a finger pressure. There is a tendency that sufficient adhesive strength cannot be exerted.

[0053] The polydispersity (weight average molecular weight / number average molecular weight) of the polyester resin (A1) is 20 It is preferably 15 or less, more preferably 10 or less. If the dispersion degree is too high, adhesive residue due to low molecular weight components tends to be more likely to occur. There is no problem even if the degree is low.

[0054] As an index of the degree of dispersion, Mw / Mp (weight average molecular weight / peak top molecular weight) is used. The smaller the Mw / Mp, the more preferable it is, and it is preferably 10 or less. It is particularly preferable that Mw / Mp is 3 or less, and most preferably 1.5 or less. However, due to the high content of low molecular weight components, adhesive residue tends to remain.

[0055] Furthermore, the number average molecular weight and weight average molecular weight do not contain low molecular weight components, which is important for adhesion. It is preferable to reduce the amount of residual agent, and it is recommended that the amount of components with a molecular weight of 1000 or less is 10% or less. It is more preferable that the ratio is 5% or less.

[0056] The above-mentioned dispersity and the ratio of low molecular weight components are determined based on the trivalent hydroxyl group for constituting the polyester resin (A1). The content of polyhydric alcohol components and / or polyvalent carboxylic acid components of 3 or more, and The polymerization reaction conditions (temperature, degree of vacuum, stirring, reaction time, etc.) can be adjusted depending on whether depolymerization occurs or not and the conditions. This can be done.

[0057] The number average molecular weight and weight average molecular weight are calculated in terms of standard polystyrene molecular weight. The average molecular weight is measured by high performance liquid chromatography (Waters 2695 (separation module) and Waters 2414 (detector) Column: Shodex GPC KF-806L (exclusion limit: 2 × 10 7 , separation Range: 100 to 2×10 7 Theoretical plate number: 10,000 plates / unit, Packing material: styrene-divinyl The measurements were taken using three tubes (a 10μm diameter olefin copolymer, a 10μm diameter filler particle size) in series.

[0058] The glass transition temperature of the polyester resin (A1) is -100 to 20°C. is preferable, -80 to 0°C is particularly preferable, and -70 to -20°C is particularly preferable. If the transfer temperature is too high, flexibility will be lost, conformability to uneven surfaces will be poor, and initial adhesion will decrease. It tends not to be able to exert sufficient adhesive strength with finger pressure, and if the glass transition temperature is too low, The mechanical strength and heat resistance tend to decrease. It is measured using a scanning calorimeter.

[0059] It is more preferable that the polyester resin (A1) does not crystallize. Even if crystallization occurs, the crystallization temperature is preferably 0°C or lower, particularly -30°C or lower. If the temperature is too high, the tack tends to disappear. It is more preferable that the density is low, and it is 35 J / g or less, particularly 20 J / g or less, and further 15 J / g or less. If the crystallization energy is too high, the tack tends to disappear. The crystallization energy mentioned above is the energy consumed when heating and melting a crystallized substance. and can be measured by a differential scanning calorimeter (DSC).

[0060] The polyester resin (A1) preferably contains substantially no acidic groups. The acid value of the polyester resin (A1) is preferably 10 mgKOH / g or less. , more preferably 5 mgKOH / g or less, even more preferably 3 mgKOH / g or less, particularly Preferably it is 1 mgKOH / g or less, and most preferably 0.5 mgKOH / g or less. However, if the acid value is too high, durability tends to decrease. In order to adjust the acid value, for example, a polyhydric alcohol may be added during the esterification reaction or the transesterification reaction. This can be done by increasing the ratio of alcohol or adjusting the reaction conditions. The lower limit of the acid value of the polyester resin (A1) is usually 0 mgKOH / g. It is determined by neutralization titration according to IS K0070. The acid value in the present invention is the ratio of the number of carboxyl groups in the polyester resin (A1) to the number of carboxyl groups in the polyester resin (A1). The carboxyl group is neutralized with a basic compound. Also included are those in the carboxylate ion state.

[0061] The polyester resin (A1) preferably contains a hydroxyl group. The hydroxyl value of the terephthalic resin (A1) is usually 1 to 100 mgKOH / g, preferably 3 up to 50 mgKOH / g, particularly preferably 5 to 40 mgKOH / g, and further preferably 15 ~30mgKOH / g. If the hydroxyl value is too low, the number of hydroxyl groups that react with compound (B) will decrease, and In order to increase the hydroxyl value, it is necessary to decrease the molecular weight. Therefore, if the hydroxyl value is too high, low molecular weight components tend to cause adhesive residue. be. In the present invention, the hydroxyl value (mgKOH / g) is the value of the polyester resin (A 1) Dissolve 1g in 30g of a mixed solvent of toluene / pyridine = 5 / 5 (weight ratio) and measure according to the JIS standard. It is determined by neutralization titration based on K0070.

[0062] The ester group concentration of the polyester resin (A1) is 1 to 12 mmol / g. It is preferable that the amount of the hydroxyl group is 3 to 11 mmol / g, more preferably 3 to 11 mmol / g, and further preferably 5 to 10 mmol / g. If the ester group concentration is too low, the polarity of the polyester resin (A1) becomes too low. If the temperature is too high, the polarity will increase too much and the initial adhesion will tend to be poor. Therefore, the solution stability tends to be poor.

[0063] The ester group concentration (mmol / g) is the concentration of ester groups in 1 g of polyester resin (A1). This refers to the number of moles of ter groups, and can be calculated from the amount of the compound to be charged. The method is to use the smaller number of moles of polycarboxylic acid or polyhydric alcohol as the final product. This is the value divided by the total weight of the container, and an example of the calculation formula is shown below. When the amounts of polycarboxylic acid and polyhydric alcohol charged are equal in moles, the following reaction is performed: Either formula may be used. In addition, monomers with both carboxylic acid and hydroxyl groups are used, and caprolactone is also used. When preparing polyester from tons, the calculation method will be changed appropriately.

[0064] <When polycarboxylic acids are in short supply> Ester group concentration (mmol / g) = [(A1 / α1 × m1 + A2 / α2 × m2 + A3 / α3×m3···) / Z×1000 A: Amount of polycarboxylic acid (g) α: Molecular weight of polycarboxylic acid m: number of carboxyl groups per molecule of polycarboxylic acid Z: Finished weight (g)

[0065] <When there is little polyhydric alcohol> Ester group concentration (mmol / g) = [(B1 / β1×n1+B2 / β2×n2+B3 / β3×n3···) / Z×1000 B: Amount of polyhydric alcohol (g) β: Molecular weight of polyhydric alcohol n: number of hydroxyl groups per molecule of polyhydric alcohol Z: Finished weight (g)

[0066] The ester group concentration can also be measured by a known method such as NMR. For example, the ester group concentration of the polyester resin (A1) is 1 H-NMR measurement (proton nuclear magnetic resonance spectroscopy), 13 C-NMR measurement (carbon-type nuclei This can be done by magnetic resonance spectroscopy.

[0067] [Unsaturated Group-Containing Polyester Resin (a1)] In the present invention, in order to efficiently reduce the adhesive strength after energy application, polyester The unsaturated group-containing polyester resin (a1) is obtained by introducing an unsaturated group into the polyester resin (A1). That's fine. By using the unsaturated group-containing polyester resin (a1), the energy - After application, the cohesive strength tends to be increased and the adhesive strength tends to be reduced. The polyester resin (a1) is a polyester resin containing an ethylenically unsaturated group in its structure. Preferably, the terminal of the main chain or the terminal of the side chain of the polyester resin (A1) Preferably, the crosslinking point molecular weight is In terms of being able to increase the size, those containing an ethylenically unsaturated group at the end of the main chain are preferred. .

[0068] [Compound (B)] The compound (B) used in the present peelable pressure-sensitive adhesive composition is also a crosslinking agent, and when energy is applied, It is also a reactive compound. The compound (B) may be, for example, a polyimide having a (meth)acryloyl group in the side chain. Socyanates are an example.

[0069] The polyisocyanate containing a (meth)acryloyl group in the side chain is not particularly limited. However, for example, when polyisocyanate is reacted with a hydroxyl group-containing (meth)acrylic compound, After producing urethane (meth)acrylate with isocyanate groups remaining, Allophanate compounds, or one isocyanate of a trifunctional or higher polyisocyanate Examples include compounds in which a hydroxyl group-containing (meth)acrylate compound is reacted with a nate group. Among them, allophanate is particularly advantageous in that it can stably have a (meth)acryloyl group on the side chain. The hydroxylated compounds are preferred.

[0070] The polyisocyanate is not particularly limited, and examples thereof include aromatic and aliphatic polyisocyanates. Examples of the polyisocyanates include aromatic and alicyclic polyisocyanates. Specifically, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, Anate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate , modified diphenylmethane diisocyanate, xylylene diisocyanate, tetramethyl Xylylene diisocyanate, phenylene diisocyanate, naphthalene diisocyanate aromatic polyisocyanates such as methyl methacrylate, Hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, isophorone Norbornene diisocyanate, 1,3-bis(isocyanatomyl) cyclohexane, and other alicyclic polyisocyanates; Hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine Polyisocyanates such as diisocyanates, aliphatic polyisocyanates such as lysine triisocyanate, etc. Trimers or polymers of isocyanates or polyisocyanates, vinyl tulette-type polyisocyanate, water-dispersed polyisocyanate (e.g., Nippon Polyurethane) "Aquanate 100," "Aquanate 110," and "Aquanate 200" manufactured by Aquan Industrial Co., Ltd. ", "Aquanate 210", etc.), or the reaction of these polyisocyanates with polyols These may be used alone or in combination of two or more. However, because of their versatility, tolylene diisocyanate, isophorone diisocyanate, Hexamethylene diisocyanate is preferred, and most preferably hexamethylene diisocyanate. This is Nate.

[0071] Examples of the hydroxyl group-containing (meth)acrylic compound include 2-hydroxyethyl ( meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl butyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxy Hexyl (meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxy Dipropyl phthalate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth) ) acrylate, caprolactone-modified 2-hydroxyethyl (meth)acrylate, etc. a hydroxyl group-containing (meth)acrylic compound having one hydroxyl group and one (meth)acrylate; Pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate ) acrylate, caprolactone-modified dipentaerythritol penta(meth)acrylate Caprolactone-modified pentaerythritol tri(meth)acrylate, ethylene oxide Side-modified dipentaerythritol penta(meth)acrylate, ethylene oxide modified pentaerythritol tri(meth)acrylate and other acrylates having one or more hydroxyl groups and 2 Examples include hydroxyl group-containing (meth)acrylic compounds having one or more (meth)acrylates. Among these, it is advantageous in that it can produce compound (B) with few impurities and is less likely to leave adhesive residue. , a hydroxyl group-containing (meth)acrylic compound having one hydroxyl group and one (meth)acrylate It is preferable to use a 2-hydroxyethylene glycol diol, in particular, in order to reduce impurities. 2-Hydroxypropyl (meth)acrylate, 2-Hydroxypropyl (meth)acrylate, 2-Hydroxypropyl (meth)acrylate Uses 4-hydroxybutyl (meth)acrylate These may be used alone or in combination of two or more.

[0072] The number of isocyanate groups contained in the compound (B) depends on the reactivity with the adhesive resin (A). From this point of view, it is preferable that the number is two or more, and more preferably two.

[0073] The compound (B) is a compound containing an ethylenically unsaturated group and two or more isocyanate groups. It is preferable that the compound (B1) is a compound (B1) having the formula (B1).

[0074] The number of ethylenically unsaturated groups contained in the compound (B) determines the curability after energy is applied. From this viewpoint, the number is usually 2 or more, preferably 2 to 20, and more preferably 2 to 5. do.

[0075] Specific examples of the compound (B) include compounds represented by the following general formula (1): .

[0076] [ka]

[0077] In the formula, n represents a positive integer, for example, 20 or less, preferably 1 to 5. The R1 is hydrogen or a methyl group, preferably hydrogen. The R2 is C, O, N and S. Specifically, for example, -COO-, -CO-, -O-, alkylene chains and oxyalkylene These may be combined in two or more. A combination of - and an alkylene chain is preferred, and a combination of -COO- and an alkylene chain is particularly preferred. The alkylene chain is, for example, an alkylene chain having 1 to 10 carbon atoms. Among these, alkylene chains having 1 to 5 carbon atoms are particularly preferred. The oxyalkylene chain may be, for example, an oxyethylene chain or an oxypropylene chain. Examples of such oxyethylene chains include oxyethylene chains and oxybutylene chains, and two or more of such oxyethylene chains may be combined. Each of the oxyalkylene chains may be a repeating oxyalkylene chain. In this case, the total number of repeating units is preferably 2 to 20.

[0078] The above R3 and R4 each independently represent a bond containing at least one selected from C, O, N and S. It is a copolymer of the above polyisocyanates, such as methyltoluene, isophorone, and hexamethylene. Part of the diisocyanate backbone and the combination of these diisocyanate backbone and -NHCO- It is preferable that the combination

[0079] The most preferred structure of compound (B) is shown in the following general formula (2).

[0080] [ka]

[0081] These compounds (B) may be used alone or in combination of two or more.

[0082] The content of the compound (B) is determined by the amount of functional groups contained in the adhesive resin (A), ) molecular weight, and for the purpose of controlling the adhesive strength and elongation after irradiation with active energy rays. The amount of the adhesive resin (A) can be appropriately selected, but it is usually 0.1 to 50 parts by weight based on 100 parts by weight of the adhesive resin (A). It is preferably 0.5 to 25 parts by weight, more preferably 1 to 20 parts by weight. It is preferable. If the amount of compound (B) is too small, the cohesive strength will be insufficient and sufficient durability will not be obtained. If the amount is too large, the flexibility before energy application decreases, and adhesive strength tends to decrease. do.

[0083] In the present invention, the hydroxyl group concentration (mmol / g) of the adhesive resin (A) is (X), and the compound If the isocyanate group concentration (mmol / g) contained in substance (B) is (Y), then 0. 1≦(Y) / (X)≦3.0 means that the adhesive network after energy application It is preferable that the ratio (Y) / (X) satisfies 0.2≦(Y) / (X)≦2.0. It is particularly preferred that (Y) / (X) satisfies 0.5≦(Y) / (X)≦1.5. If the temperature is too high, bubbles may occur when the adhesive layer is formed, which may result in a poor appearance. If the adhesive is too thick, the overall network becomes loose, which tends to cause adhesive residue.

[0084] In the present peelable pressure-sensitive adhesive composition, other crosslinking agents may be used in addition to the compound (B). It is also possible.

[0085] [Other crosslinking agents] Other crosslinking agents include those having functional groups that react with the functional groups contained in the adhesive resin (A). Any compound that can be used is acceptable, for example, bisphenol A-epichlorohydrin type epoxy resin. Fat, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether Ether, Glycerin Diglycidyl Ether, Glycerin Triglycidyl Ether, 1,6 -Hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether ether, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether , pentaerythritol polyglycidyl erythritol, diglycerol polyglycidyl Epoxy compounds such as ethers, tetramethylolmethane-tri-β-aziridinylpropionates N,N Trimethylolpropane-tri-β-aziridinyl propionate '-Diphenylmethane-4,4'-bis(1-aziridinecarboxamide), N,N' -Aziridines such as hexamethylene-1,6-bis(1-aziridinecarboxamide) Compounds, hexamethoxymethylmelamine, hexaethoxymethylmelamine, hexapropion oxymethylmelamine, hexaptoxymethylmelamine, hexapentyloxymethylmelamine melamine compounds such as melamine, hexahexyloxymethylmelamine, and melamine resins; 4-Tolylene diisocyanate, 2,6-tolylene diisocyanate, hydrogenated tolylene Isocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate nate, hexamethylene diisocyanate, diphenylmethane-4,4-diisocyanate Isophorone diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane , tetramethylxylylene diisocyanate, 1,5-naphthalene diisocyanate, Triphenylmethane triisocyanate, and these polyisocyanate compounds and triisocyanates Adducts with polyol compounds such as methylolpropane, and polyisocyanates Isocyanate compounds such as biuret compounds and isocyanurates, glyoxal , malondialdehyde, succindialdehyde, maleic dialdehyde, glutaric acid Aldehyde compounds such as aldehyde, formaldehyde, acetaldehyde, and benzaldehyde substances, hexamethylenediamine, triethyldiamine, polyethyleneimine, hexamethylene diethylenetriamine, triethyltetraamine, isophorone diamine Amine compounds such as amines, amino resins, polyamides, aluminum, iron, copper, zinc, tin, Titanium, nickel, antimony, magnesium, vanadium, chromium, zirconium, etc. Metal chelate compounds such as polymetallic acetylacetone and acetoacetyl ester coordination compounds Among these, the ability to improve adhesion to the substrate and the reaction with the adhesive resin (A) are particularly noteworthy. In view of the properties, isocyanate compounds are preferably used. These other crosslinking agents may be used alone or in combination of two or more.

[0086] <Adhesive composition> Furthermore, the pressure-sensitive adhesive composition according to one embodiment of the present invention (hereinafter referred to as "the pressure-sensitive adhesive composition") The polyester resin (A1) and a copolymer containing an unsaturated group and two or more isocyanate groups The compound (B1) is contained, and if necessary, a polymerization initiator (C) and a hydrolysis inhibitor are contained. The polyester resin (A1) and the copolymer (B) may contain a saturated group and two or more substituted groups. The compound (B1) containing a socyanate group is as described above. The present adhesive composition can be used not only as a peelable adhesive composition but also as a non-peeling adhesive composition. It can also be used in adhesive compositions.

[0087] [Polymerization initiator (C)] The presence of the polymerization initiator (C) in the present peelable pressure-sensitive adhesive composition makes it possible to improve the peelability of the composition when peeled from an adherend. In addition, it is preferable in that the curing reaction can be stabilized.

[0088] Examples of the polymerization initiator (C) include a photopolymerization initiator (C1), a thermal polymerization initiator (C2), and a It is possible to use various polymerization initiators such as (C1), but it is particularly preferable to use a photopolymerization initiator (C2). It is possible to use it and harden it by applying energy such as ultraviolet light for a very short time. This is preferable in that

[0089] Such a photopolymerization initiator (C1) may be any one that generates radicals by the action of light. Examples of the hydroxybenzoates include, but are not limited to, diethoxyacetophenone, 2-hydroxy-1-[4-[4 -(2-hydroxy-2-methylpropionyl)benzyl]phenyl]-2-methylpropane -1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl Dimethyl ketal, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2- propyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-2-methylpropional Phosphorino(4-thiomethylphenyl)propan-1-one, 2-benzyl-2-dimethyl Amino-1-(4-morpholinophenyl)butanone, 2-hydroxy-2-methyl-1- Acetophenones such as [4-(1-methylvinyl)phenyl]propanone oligomer; Benzoin, Benzoin Methyl Ether, Benzoin Ethyl Ether, Benzoin Isopropyl Benzoins such as benzoin isobutyl ether and benzoin isobutyl ether; benzophenone, o- Methyl benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl diphenyl sulfide, 3,3',4,4'-tetra(t-butylperoxycarbonyl) 4-benzoyl-N, 2,4,6-trimethylbenzophenone, ,N-dimethyl-N-[2-(1-oxo-2-propenyloxy)ethyl]benzene Tanaminium bromide, (4-benzoylbenzyl)trimethylammonium chloride, etc. Benzophenones; 2-isopropylthioxanthone, 4-isopropylthioxanthone thioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro- 4-Propoxythioxanthone, 2-(3-dimethylamino-2-hydroxy)-3,4 Thioxanthones such as -dimethyl-9H-thioxanthone-9-one mesochloride; 2, 4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,6-dimethyl 2,4,4-trimethyl-pentylphosphine oxide, bis( Acyl phosphines such as 2,4,6-trimethylbenzoyl-phenylphosphine oxide Examples of such compounds include fluorine oxides. These photopolymerization initiators (C1) may be used alone or in combination of two or more kinds.

[0090] Among these, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy- 1-[4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl]-2-methyl Tylpropan-1-one, 2,4,6-trimethylbenzoyl-diphenylphosphine It is preferable to use benzyl dimethyl ketal or benzyl oxide.

[0091] In addition, triethanolamine and triisopropanol are used as assistants for the photopolymerization initiator (C1). amine, 4,4'-dimethylaminobenzophenone (Michler's ketone), 4,4'- Diethylaminobenzophenone, 2-dimethylaminoethylbenzoic acid, 4-dimethylamino Ethyl 4-dimethylaminobenzoate, (n-butoxy)ethyl 4-dimethylaminobenzoate, 4-dimethyl Isoamyl aminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2,4- Diethylthioxanthone, 2,4-diisopropylthioxanthone, etc. can also be used in combination. It is Noh.

[0092] Examples of the thermal polymerization initiator (C2) include methyl ethyl ketone peroxide. Cyclohexanone peroxide, methylcyclohexanone peroxide, methyl Acetoacetate peroxide, acetylacetate peroxide, 1,1-bis( t-Hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t -hexylperoxy)-cyclohexane, 1,1-bis(t-butylperoxy)-3 ,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)-2-methyl 1,1-bis(t-butylperoxy)-cyclohexane, 1,1 -Bis(t-butylperoxy)cyclododecane, 1,1-bis(t-butylperoxy)cyclododecane ) butane, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane , p-menthane hydroperoxide, diisopropylbenzene hydroperoxide , 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide oxide, t-hexyl hydroperoxide, t-butyl hydroperoxide , α,α'-bis(t-butylperoxy)diisopropylbenzene, dicumylperoxy Side, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, t-butyl Fluorine peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5- Bis(t-butylperoxy)hexyne-3, isobutyryl peroxide, 3,5,5 -Trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide -oxide, stearoyl peroxide, succinic acid peroxide, m-toluoyl Dibenzoyl peroxide, benzoyl peroxide, di-n-propyl peroxide Dicarbonate, diisopropyl peroxydicarbonate, bis(4-t-butylcyclohexyl) Di-2-ethoxyethyl peroxydicarbonate Di-2-ethoxyhexyl peroxydicarbonate, Di-3-methoxybutyl peroxydicarbonate -oxydicarbonate, di-s-butyl peroxydicarbonate, di(3-methyl- 3-Methoxybutyl) peroxydicarbonate, α,α'-bis(neodecanoyl peroxydicarbonate) Oxy)diisopropylbenzene, cumyl peroxyneodecanoate, 1,1,3,3 -Tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethoxy Tylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butyl peroxyneodecanoate, t-hexylperoxypivalate, t-butylperoxy oxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexanoate Sanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate ester, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2 -Ethylhexanoate, t-Hexylperoxyisopropyl monocarbonate, t- Butyl peroxyisobutyrate, t-butyl peroxymalate, t-butyl peroxy 3,5,5-trimethylhexanoate, t-butyl peroxylaurate, t-butyl t-Butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl Silmonocarbonate, t-butylperoxyacetate, t-butylperoxy-m- Toluyl benzoate, t-butyl peroxybenzoate, bis(t-butylperoxy) Isophthalate, 2,5-dimethyl-2,5-bis(m-toluylperoxy)hexyl San, t-hexyl peroxybenzoate, 2,5-dimethyl-2,5-bis(benzo (Ilperoxy)hexane, t-butylperoxyallyl monocarbonate, t-butyl Trimethylsilyl peroxide, 3,3',4,4'-tetra(t-butylperoxide) (carbonyl)benzophenone, 2,3-dimethyl-2,3-diphenylbutane, and other organic peroxides Oxide initiator; 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, 1-[(1-cyano-1-methylethyl)azo]formamide, 1,1'-azobis(cyano) cyclohexane-1-carbonitrile), 2,2'-azobis(2-methylbutyronitrile) ), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylbutyronitrile) 2,2'-Azobis(2-methylpropionamidine) dihydrochloride 2,2'-azobis(2-methyl-N-phenylpropionamidine) dihydrochloride Lid, 2,2'-azobis[N-(4-chlorophenyl)-2-methylpropionamid dihydridochloride, 2,2'-azobis[N-(4-hydrophenyl)-2-methyl propionamidine] dihydrochloride, 2,2'-azobis[2-methyl-N-(furan (phenylmethyl)propionamidine]dihydrochloride, 2,2'-azobis[2-methyl N-(2-propenyl)propionamidine dihydrochloride, 2,2'-azobiphenyl N-(2-hydroxyethyl)-2-methylpropionamidine dihydrochloride , 2,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane]di Hydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] Dihydrochloride, 2,2'-azobis[2-(4,5,6,7-tetrahydro-1H- 1,3-diazepin-2-yl)propane]dihydrochloride, 2,2'-azobis[2 -(3,4,5,6-tetrahydropyrimidin-2-yl)propane]dihydrochloride , 2,2'-azobis[2-(5-hydroxy-3,4,5,6-tetrahydropyrimidinyl] 2,2'-azobis[2-[1-(2-hydroxybenzoyl)propane]dihydrochloride, 2,2-hydroxyethyl-2-imidazolin-2-ylpropane dihydrochloride '-Azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis[ 2-Methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propyl amide], 2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl) propionamide], 2,2'-azobis[2-methyl-N-(2-hydroxypropyl)ethyl]propionamide], 2,2'-azobis(2-methylpropionamide) , 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(2- Methylpropane), Dimethyl-2,2-azobis(2-methylpropionate), 4,4 '-Azobis(4-cyanopentanoic acid), 2,2'-azobis[2-(hydroxymethyl ) propionitrile] and other azo-based initiators. One kind may be used alone, or two or more kinds may be used in combination.

[0093] The content of the polymerization initiator (C) is as follows, relative to 100 parts by weight of the adhesive resin (A): The amount is preferably 0.01 to 10 parts by weight, and particularly preferably 0.1 to 5 parts by weight. If the blending amount is too small, the curing may be insufficient. If the amount is too large, there is a concern that the polymerization initiator (C) will become a residual adhesive.

[0094] [Hydrolysis inhibitor (D)] The hydrolysis inhibitor (D) is not particularly limited, and any of the conventionally known inhibitors may be used. For example, the carboxylic acid terminal group of the polyester resin (A1) can be Examples of compounds that react with and bond to the carboxyl end group include carbodiimide groups, Examples include compounds having functional groups such as epoxy groups and oxazoline groups. However, the carbodiimide group-containing compound quenches the catalytic activity of the protons derived from the carboxyl end group. This is preferable in that it has a high dissipation effect.

[0095] The carbodiimide group-containing compound used in the present peelable pressure-sensitive adhesive composition is usually a carbodiimide group-containing compound. A known carbodiimide having one or more carbodiimide groups (-N=C=N-) in the molecule is used. However, in order to improve durability under high temperature and humidity, it is recommended to incorporate a carbodiimide group into the molecule. Preferably, the compound contains two or more of these groups, i.e., a polyvalent carbodiimide compound. In particular, those containing 3 or more, more preferably 5 or more, and especially 7 or more carbodiimide groups in the molecule are preferred. It is preferable that the compound is a compound having the formula: The number of carbodiimide groups in a molecule is usually 50 or less. If there are too many groups, the molecular structure becomes too large, which tends to reduce compatibility.

[0096] The carbodiimide group-containing compound has a weight average molecular weight of 100 to 2000 mg / kg from the viewpoint of hydrolysis resistance. It is preferable to use a compound having a high weight average molecular weight. 00 or more, more preferably 2000 or more, and more preferably 3000 or more. The upper limit of the weight average molecular weight is usually 50,000.

[0097] Furthermore, it is preferable that the carbodiimide group-containing compound has low volatility. It is preferable to use one having a high number average molecular weight, usually 300 to 10,000, preferably It is between 1000 and 5000.

[0098] If the molecular weight of the carbodiimide group-containing compound is too small, the hydrolysis resistance tends to decrease. If the molecular weight is too large, the compatibility with the adhesive resin (A) tends to decrease. .

[0099] The carbodiimide equivalent of the carbodiimide group-containing compound is preferably 50 to 1000 0, particularly preferably 100 to 1000, and further preferably 150 to 500. The carbodiimide equivalent weight refers to the chemical formula weight per carbodiimide group.

[0100] Furthermore, the carbodiimide group-containing compound is a diisopropyl ether in the presence of a carbodiimide catalyst. Polycarbodiimide compounds produced by decarboxylation condensation of cyanates It is also preferable to use

[0101] (Polycarbodiimide compounds) Polycarbodiimide compounds are produced by condensing organic diisocyanate compounds. You can get more. Examples of the organic diisocyanate compound include 1,5-naphthylene diisocyanate. 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane Tanethene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylenediisocyanate Isocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate , a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, Aromatic diisocyanates such as xylylene diisocyanate and tetramethylxylylene diisocyanate Socyanate compounds; Acyclic aliphatic diisocyanates such as hexamethylene diisocyanate, cyclohexane -1,4-Diisocyanate, isophorone diisocyanate, dicyclohexylmethane- 4,4'-Diisocyanate, Methylcyclohexanediisocyanate, 2,5(2,6 )-bis(isocyanatomethyl)bicyclo[2.2.1]heptane and other alicyclic diisocyanates These may be used alone or in combination of two or more. The above may be used in combination. Among these, aromatic di-aminobenzoates are preferred in that they can be used to produce a peelable pressure-sensitive adhesive composition having excellent resistance to moisture and heat. isocyanate compounds are preferred, with tetramethylxylene diisocyanate being more preferred. .

[0102] The organic diisocyanate compound is decarboximed in a conventional manner using a known carbodiimide catalyst. By carrying out an acid condensation reaction, a polycarbodiimide compound can be obtained.

[0103] The polycarbodiimide compound has little change in haze even under high temperature and high humidity conditions, and is moisture resistant. It is preferable that the compound be an aromatic polycarbodiimide compound because it can be used as an adhesive with excellent thermal properties. It is preferable that:

[0104] Commercially available polycarbodiimide compounds include, for example, Carbodiimide manufactured by Nisshinbo Chemical Co., Ltd. Zylight (registered trademark) V-09GB, V-02B, V-04K, V-04PF, V-07 BASF's Elastostab H01, and among them, Carbodilite V -09GB is preferred.

[0105] Examples of the epoxy group-containing compound include a glycidyl ester group-containing compound and a glycidyl ester group-containing compound. Compounds containing a silyl ether group are preferred.

[0106] Examples of the glycidyl ester group-containing compound include benzoic acid glycidyl ester. , t-Bu-benzoic acid glycidyl ester, p-toluic acid glycidyl ester, cyclo Hexanecarboxylic acid glycidyl ester, pelargonic acid glycidyl ester, stearin Acid glycyl ester, lauric acid glycidyl ester, palmitic acid glycidyl ester , Behenic acid glycidyl ester, Versatic acid glycidyl ester, Glycidyl oleate Glycidyl ester, linoleic acid glycidyl ester, linolenic acid glycidyl ester, behen Glycidyl ester of glycerol, glycidyl ester of stearolic acid, diglyceryl terephthalate diglycidyl ester, isophthalic acid diglycidyl ester, phthalic acid diglycidyl ester, Naphthalenedicarboxylic acid diglycidyl ester, methyl terephthalic acid diglycidyl ester Diglycidyl ester of hexahydrophthalic acid, diglycidyl ester of tetrahydrophthalic acid ester, cyclohexanedicarboxylic acid diglycidyl ester, adipate diglycidyl ester ester, succinic acid diglycidyl ester, sebacic acid diglycidyl ester, dodecane diglycidyl diglycidyl ester of octadecanedicarboxylic acid, diglycidyl ester of octadecanedicarboxylic acid, Examples include glycidyl ester of methylcellulose and tetraglycidyl ester of pyromellitic acid. These may be used alone or in combination of two or more.

[0107] Examples of the glycidyl ether group-containing compound include phenyl glycidyl ether , o-phenylglycidyl ether, 1,4-bis(β,γ-epoxypropoxy)butadiene hexane, 1,6-bis(β,γ-epoxypropoxy)hexane, 1,4-bis(β,γ-epoxypropoxy)hexane 1-(β,γ-epoxypropoxy)benzene, 1-(β,γ-epoxypropoxy)-2-ethoxyethane , 1-(β,γ-epoxypropoxy)-2-benzyloxyethane, 2,2-bis-[ p-(β,γ-epoxypropoxy)phenyl]propane and 2,2-bis-(4-hydroxyphenyl)propane Bis-(hydroxyphenyl)propane and 2,2-bis-(4-hydroxyphenyl)methane Examples include bisglycidyl polyethers obtained by the reaction of phenol with epichlorohydrin. These can be used alone or in combination of two or more.

[0108] The oxazoline group-containing compound is preferably a bisoxazoline compound. Specifically, for example, 2,2'-bis(2-oxazoline), 2,2'-bis(4-methyl- 2-oxazoline), 2,2'-bis(4,4-dimethyl-2-oxazoline), 2,2 '-Bis(4-ethyl-2-oxazoline), 2,2'-bis(4,4'-diethyl-2 -oxazoline), 2,2'-bis(4-propyl-2-oxazoline), 2,2'-bi bis(4-butyl-2-oxazoline), 2,2'-bis(4-hexyl-2-oxazoline) 2,2'-bis(4-phenyl-2-oxazoline), 2,2'-bis(4-cyclohexyl) 2,2'-bis(4-benzyl-2-oxazoline), 2,2'-bis(4-benzyl-2-oxazoline) , 2,2'-p-phenylenebis(2-oxazoline), 2,2'-m-phenylenebis (2-oxazoline), 2,2'-o-phenylenebis(2-oxazoline), 2,2' -p-phenylenebis(4-methyl-2-oxazoline), 2,2'-p-phenylenebis bis(4,4-dimethyl-2-oxazoline), 2,2'-m-phenylenebis(4-methyl 2,2'-m-phenylenebis(4,4-dimethyl-2-oxazoline), 2,2'-ethylenebis(2-oxazoline), 2,2'-tetramethylene Bis(2-oxazoline), 2,2'-hexamethylenebis(2-oxazoline), 2, 2'-Octamethylenebis(2-oxazoline), 2,2'-decamethylenebis(2-oxazoline) 2,2'-ethylenebis(4-methyl-2-oxazoline), 2,2'- Tetramethylenebis(4,4-dimethyl-2-oxazoline), 2,2'-9,9'-di Phenoxyethane bis(2-oxazoline), 2,2'-cyclohexylene bis(2-oxazoline) Examples include 2,2'-diphenylenebis(2-oxazoline), 2,2'-diphenylenebis(2-oxazoline), etc. Among these, 2,2'-bis(2-oxazoline) has high reactivity with polyester. Furthermore, the bisoxazoline compounds listed above are the most preferred from the viewpoint of the present invention. As long as the effect is achieved, these can be used alone or in combination of two or more.

[0109] The hydrolysis inhibitor (D) is preferably low in volatility, and therefore has a molecular weight It is preferable to use a material with a high

[0110] The amount of the hydrolysis inhibitor (D) to be added is 0. The amount is preferably 0.1 to 10 parts by weight, particularly preferably 0.1 to 5 parts by weight, and further preferably If the blending amount is too large, the compatibility with the adhesive resin (A) becomes poor. It tends to become cloudy due to poor properties, and if it is too little, it is difficult to obtain sufficient durability. There is a tendency.

[0111] The amount of the hydrolysis inhibitor (D) to be added is determined depending on the acid value of the adhesive resin (A). It is preferable to optimize the amount of the adhesive resin (A) in the peelable adhesive composition. The desired total of carboxy groups (i) and the hydrolysis inhibitor (D) in the release pressure-sensitive adhesive composition The molar ratio ((ii) / (i)) of the total amount of functional groups (ii) is 0.5≦(ii) / (i). It is preferable that (ii) / (i) is 1≦(ii) / (i)≦1000, and it is particularly preferable that (ii) / (i) is 1≦(ii) / (i)≦1000, and it is even more preferable that (ii) / (i) is 1. 5≦(ii) / (i)≦100. If the content ratio of (ii) to (i) is too high, the compatibility with the adhesive resin (A) decreases. As a result, adhesive strength, cohesion, and durability tend to decrease. When the temperature is low, the moisture and heat resistance tends to decrease.

[0112] [Active energy ray-curable compound] In the present peelable pressure-sensitive adhesive composition, in order to set the unsaturated group concentration described below within the desired range, If necessary, an active energy ray-curable compound can be used.

[0113] Examples of the active energy ray-curable compound include urethane (meth)acrylate. and ethylenically unsaturated monomers having an ethylenically unsaturated group.

[0114] [Urethane (meth)acrylate compounds] The urethane (meth)acrylate compound has a urethane bond in the molecule. ) acrylate compounds, and is a mixture of hydroxyl group-containing (meth)acrylic compounds and polyisocyanates. The copolymer can be produced by further reacting it with a polyol, if necessary.

[0115] The hydroxyl group-containing (meth)acrylic compound may be any of those described above in connection with the compound (B). Among them, hydroxyl group-containing (meth)acrylic copolymers having three or more acryloyl groups can be used. These compounds may be used alone or in combination of two or more. It is possible.

[0116] The polyisocyanate is not particularly limited, and may be any of the compounds described above in connection with the compound (B). These can be used alone or in combination of two or more. can.

[0117] Such polyols are not particularly limited, and examples thereof include ethylene glycol, Diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene ethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol Coal, butylene glycol, polybutylene glycol, 1,6-hexanediol, Dipentyl glycol, cyclohexanedimethanol, hydrogenated bisphenol A, poly Caprolactone, trimethylolethane, trimethylolpropane, polytrimethylol Propane, pentaerythritol, polypentaerythritol, sorbitol, mannitol Polyhydric alcohols such as ethanol, glycerin, polyglycerin, and polytetramethylene glycol Polyethylene oxide, polypropylene oxide, ethylene oxide / propylene Polyesters having at least one structure of block or random copolymerization of ethylene oxides ter polyol; the polyhydric alcohol or polyether polyol and maleic anhydride, maleic anhydride Polysalts of leic acid, fumaric acid, itaconic anhydride, itaconic acid, adipic acid, isophthalic acid, etc. Polyester polyols, condensation products with base acids; caprolactone-modified polytetramethylene Caprolactone-modified polyols such as polyols; polyolefin-based polyols; hydrogenated polyols Examples include polybutadiene-based polyols such as butadiene polyols.

[0118] Further, examples of such polyols include 2,2-bis(hydroxymethyl)butyric acid , tartaric acid, 2,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 2,2-bihydroxybenzoic acid Bis(hydroxymethyl)propionic acid, 2,2-bis(hydroxyethyl)propionic acid , 2,2-bis(hydroxypropyl)propionic acid, dihydroxymethylacetic acid, bis( 4-hydroxyphenyl)acetic acid, 4,4-bis(4-hydroxyphenyl)pentanoic acid, Carboxyl group-containing polyols such as homogentisic acid and 1,4-butanediol sulfonates Also included are polyols containing sulfonic acid groups or sulfonate groups, such as sodium phosphate. These polyols can be used alone or in combination of two or more.

[0119] When a reaction product of a polyisocyanate and a polyol is used, for example, A polyisocyanate having terminal isocyanate groups obtained by reacting the above polyisocyanate with the above polyisocyanate. In the reaction of such polyisocyanate with polyol, In order to promote the reaction, metal catalysts such as dibutyltin dilaurate and 1,8-diaza It is also preferable to use an amine catalyst such as bicyclo[5.4.0]undecene-7. .

[0120] The method for producing the urethane (meth)acrylate compound is not particularly limited, and examples thereof include For example, a hydroxyl group-containing (meth)acrylic compound and a polyvalent isocyanate compound are mixed in an inert gas atmosphere. The mixture is mixed in an atmosphere and reacted at a temperature of 30 to 80°C for 2 to 10 hours. In the reaction, tin octenoate, di-n-butyltin dilaurate, lead octylate, octylic acid Urethane compounds such as potassium, potassium acetate, stannous octoate, and triethylenediamine It is preferred to use a catalyst.

[0121] The weight average molecular weight of the urethane (meth)acrylate compound is preferably 300 to 40 00, more preferably 1000 to 3500, and particularly preferably 1200 to 3000. The method for measuring the weight average molecular weight is as described above.

[0122] [Ethylenically unsaturated monomer having an ethylenically unsaturated group] The ethylenically unsaturated monomer having an ethylenically unsaturated group may be, for example, Monofunctional monomers with one ethylenically unsaturated group in one molecule, Bifunctional monomers with saturated groups, trifunctional monomers with three or more ethylenically unsaturated groups in one molecule Examples of monomers include those with higher functionality.

[0123] Examples of the monofunctional monomer include styrene, vinyl toluene, and chlorostyrene. , α-methylstyrene, methyl (meth)acrylate, ethyl (meth)acrylate, Acrylonitrile, vinyl acetate, 2-hydroxyethyl (meth)acrylate, 2-hydroxyethyl 2-Hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, phenyl Phenoxyethyl (meth)acrylate, 2-phenoxy-2-hydroxypropyl (meth)acrylate Acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 3-chlor 2-Hydroxypropyl (meth)acrylate, Glycerin mono(meth)acrylate acrylate, glycidyl (meth)acrylate, lauryl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, tricyclodecanyl (meth)acrylate (meth)acrylate, dicyclopentenyl (meth)acrylate, n-butyl (meth)acrylate acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl ( (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, iso Decyl (meth)acrylate, dodecyl (meth)acrylate, n-stearyl (meth)acrylate Acrylate, benzyl (meth)acrylate, phenol ethylene oxide modified (meth)acrylate p) acrylate, nonylphenol propylene oxide modified (meth) acrylate, Phthalic acid derivatives such as 2-(meth)acryloyloxy-2-hydroxypropyl phthalate Half ester (meth)acrylate, furfuryl (meth)acrylate, carbitol Benzyl (meth)acrylate, Benzyl (meth)acrylate, Butoxyethyl (meth)acrylate Acrylate, allyl (meth)acrylate, acryloylmorpholine, 2-hydroxy Ethyl acrylamide, N-methylol (meth)acrylamide, N-vinylpyrrolidone , 2-vinylpyridine, 2-(meth)acryloyloxyethyl acid phosphate mono Noester et al.

[0124] Examples of the bifunctional monomer include ethylene glycol di(meth)acrylate, Diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate Acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di (Meth)acrylate, dipropylene glycol di(meth)acrylate, polypropylene ethylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, Dipentyl glycol di(meth)acrylate, ethylene oxide modified bisphenol A-type di(meth)acrylate, propylene oxide modified bisphenol A-type di(meth)acrylate Acrylate, 1,6-Hexanediol di(meth)acrylate, 1,6-Hexanedi All ethylene oxide modified di(meth)acrylate, glycerin di(meth)acrylate acrylate, pentaerythritol di(meth)acrylate, ethylene glycol diglycidyl Ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate ) acrylate, phthalic acid diglycidyl ester di(meth)acrylate, hydroxypi Valine acid modified neopentyl glycol di(meth)acrylate, ethylene isocyanurate Oxide-modified diacrylate, 2-(meth)acryloyloxyethyl acid phosphite ester diesters and the like.

[0125] Examples of the tri- or higher functional monomer include trimethylolpropane tri(meth)amine. Acrylate, Pentaerythritol tri(meth)acrylate, Pentaerythritol terephthalate Dipentaerythritol tri(meth)acrylate, Dipentaerythritol tri(meth)acrylate, Dipentaerythritol tri(meth)acrylate Dipentaerythritol tetra(meth)acrylate, Dipentaerythritol penta(meth)acrylate Acrylate, Dipentaerythritol Hexa(meth)acrylate, Tri(meth)acrylate Trimethylolpropane, Glycerin Polyglycidyl Ether Poly Tri(meth)acrylate, isocyanuric acid ethylene oxide modified tri(meth)acrylate acrylate, ethylene oxide modified dipentaerythritol penta(meth)acrylate, ethylene Ethylene oxide modified dipentaerythritol hexa(meth)acrylate, ethylene oxide Oxide-modified pentaerythritol tri(meth)acrylate, ethylene oxide-modified Pentaerythritol tetra(meth)acrylate, succinic acid modified pentaerythritol Tri(meth)acrylate and the like.

[0126] In addition to the above, the ethylenically unsaturated monomers include Michael adducts of acrylic acid. Also listed are 2-acryloyloxyethyl dicarboxylic acid monoesters, and acrylic acid The Michael adducts of acrylic acid dimer, methacrylic acid dimer, acrylic acid trimer, acrylic acid trimer, methacrylic acid trimer, acrylic acid tetramer, methacrylic acid tetramer, etc. In addition, 2-acryloyloxyethyldicarboxylic acids with specific substituents can be used. Examples of carboxylic acid monoesters include 2-acryloyloxyethyl succinate monoesters. Ester, 2-methacryloyloxyethyl succinic acid monoester, 2-acryloyloxyethyl succinate Oxyethyl phthalate monoester, 2-methacryloyloxyethyl phthalate monoester 2-Acryloyloxyethyl hexahydrophthalic acid monoester, 2-Methacryloyl hydroxyethyl hexahydrophthalic acid monoester, etc. Steryl acrylates are also included.

[0127] These active esters such as urethane (meth)acrylate compounds and ethylenically unsaturated monomers The energy ray curable compounds may be used alone or in combination of two or more. In order to increase the crosslink density when used as a peelable adhesive, a multifunctional urethane (meth)acrylate is used. It is preferable to use a acrylate compound or a polyfunctional ethylenically unsaturated monomer, and particularly It is preferable to use a compound having three or more saturated groups. To enhance this, highly polar urethane (meth)acrylate compounds and compounds with polar moieties are used. It is also preferred to use ethylenically unsaturated monomers.

[0128] The content of the active energy ray curable compound is 100 parts by weight of the adhesive resin (A). The amount is preferably 1 to 50 parts by weight, more preferably 2 to 20 parts by weight, and even more preferably 3 to 50 parts by weight. If the content is too high, the adhesiveness after hardening by applying energy may be poor. The cohesive strength of the layers becomes too high, which reduces the elongation and makes the material unable to stretch. If the amount is too small, the adhesive strength after application of energy tends not to decrease much.

[0129] These active energy ray curable compounds usually contain a polymerization inhibitor. In addition to this, adding a polymerization inhibitor can improve the stability of the adhesive sheet and, for example, For example, it is preferable in that it can withstand use under severe conditions such as heat resistance and then undergo a peeling process.

[0130] The content of the polymerization inhibitor is not limited, but may be, for example, In contrast, the concentration is usually 20 to 10,000 ppm, and particularly preferably 50 to 1,000 ppm. stomach.

[0131] The polymerization inhibitor is not particularly limited, but a phenol type inhibitor may be used. It is preferable to use methoxyhydroquinone, hydroquinone, di-tert-butylhydroquinone, etc. It is preferable to use xytoluene or the like.

[0132] [Other ingredients] The present peelable pressure-sensitive adhesive composition may further contain, for example, a band, within the range not impairing the effects of the present invention. Antistatic agents, antioxidants, plasticizers, fillers, pigments, diluents, antioxidants, UV absorbers, purple It may further contain other components such as an external stabilizer and a tackifying resin. The peelable adhesive composition may be used alone or in combination of two or more. In addition to the above other ingredients, the composition may contain raw materials for producing the components of the present peelable pressure-sensitive adhesive composition. A small amount of impurities may be contained.

[0133] The present peelable pressure-sensitive adhesive composition comprises the above-mentioned pressure-sensitive adhesive resin (A), compound (B), and optionally a polymerizable compound (B). It can be obtained by mixing a polymerization initiator (C), a hydrolysis inhibitor (D), and other components.

[0134] The adhesive resin (A) is preferably the main component of the present peelable pressure-sensitive adhesive composition. The main component is a component whose content is 50% by weight or more of the entire peelable pressure-sensitive adhesive composition, and is preferably The content is 60 to 99.9% by weight, more preferably 70 to 99.7% by weight, and particularly preferably Preferably, it is 80 to 99.5% by weight, and particularly preferably, it is 90 to 99% by weight. The content of the compound (B) is 0.1 to 25% by weight of the entire peelable pressure-sensitive adhesive composition. It is preferable that the content of the hydroxybenzoate is 0.2 to 20% by weight, more preferably 0.2 to 20% by weight, and further preferably 0.5 to 15% by weight. be. The content of the polymerization initiator (C) is 0.01 to 10% by weight of the entire peelable pressure-sensitive adhesive composition. It is preferable that the content of the hydroxybenzoate is 0.1 to 5% by weight, more preferably 0.1 to 5% by weight, and further preferably 0.2 to 3% by weight. is. The content of the hydrolysis inhibitor (D) is 0.01 to 10% by weight of the entire peelable pressure-sensitive adhesive composition. It is preferable that the content of the hydroxybenzoate is 0.1 to 5% by weight, more preferably 0.1 to 5% by weight, and further preferably 0.3 to 3 times the content of the hydroxybenzoate. % by volume.

[0135] The present peelable pressure-sensitive adhesive composition has an unsaturated group concentration of 0.01 to 1.5 mmol / g. Preferably, the concentration is 0.03 to 1.2 mmol / g, more preferably 0.1 to 1 0.0 mmol / g, and particularly preferably 0.2 to 0.8 mmol / g. The concentration (mmol / g) can be calculated using the following formula: In this case, calculations are based only on the active ingredients contained in the peelable pressure-sensitive adhesive composition, excluding solvents, etc. Unsaturated group concentration (mmol / g) of the releasable pressure-sensitive adhesive composition = contained in the releasable pressure-sensitive adhesive composition Amount of unsaturated group-containing compound (mmol) / total weight of peelable pressure-sensitive adhesive composition (g)

[0136] The unsaturated group concentration can also be determined by measurement using a known method. For example, the unsaturated group concentration of the peelable pressure-sensitive adhesive composition is 1 H-NMR measurement (proton nuclear magnetic resonance spectroscopy), 13 C-NMR measurement (carbon-type nuclear magnetic resonance spectroscopy) The measurement device was a VARIAN NM An R apparatus 400-MR can be used, and deuterated chloroform can be used as the solvent.

[0137] In the present peelable pressure-sensitive adhesive composition, the unsaturated group is a carbon-carbon double bond or a carbon-carbon double bond. There is no particular limitation on the functional group as long as it has a carbon-carbon triple bond, but preferably, A functional group having a bond is preferred, and furthermore, it can be easily used with a commonly used ultraviolet irradiator. Preferably, it is a (meth)acryloyl group where possible.

[0138] In order to adjust the unsaturated group concentration of the present release pressure-sensitive adhesive composition to the desired range, (i) compound (B (ii) a method of introducing an unsaturated group into the adhesive resin (A); i) A method of adding an active energy ray curable compound, or a combination thereof, etc. However, in terms of integrating the adhesive layer after curing, method (i) or a combination of methods (i) and (ii) is preferred. is preferred.

[0139] The glass transition temperature of the present peelable pressure-sensitive adhesive composition is determined from the viewpoint of the balance between adhesive properties and various functionalities. The temperature is preferably 30°C or lower, particularly 15°C or lower, further 0°C or lower, and particularly preferably -1 If the glass transition temperature is too high, the flexibility is lost and the initial The adhesiveness will decrease over time, and it will be difficult to exert sufficient adhesive force with finger pressure, which will reduce workability. The lower limit of the glass transition temperature is usually -90°C, preferably -70°C. , and more preferably -50°C. Here, the glass transition temperature (Tg) of the present peelable pressure-sensitive adhesive composition is measured using a differential scanning calorimeter. It is something that is measured.

[0140] The present peelable pressure-sensitive adhesive composition preferably contains substantially no acidic groups, and specifically The acid value is preferably 10 mgKOH / g or less, more preferably 5 mgKOH / g or less. / g or less, particularly preferably 3 mgKOH / g or less, and further preferably 1 mgKOH / g or less. The lower limit of the acid value is usually 0 mg KOH / g or less, and particularly preferably 0.5 mg KOH / g or less. The acid value of the present peelable pressure-sensitive adhesive composition is determined based on the neutralization droplet size in accordance with JIS K0070. This is required by law. In the present invention, the acid value means the content of carboxy groups. Some of these compounds are in the carboxylate ion state, where the carboxyl group is neutralized with a basic compound. This also includes.

[0141] The releasable pressure-sensitive adhesive composition is crosslinked to form a releasable pressure-sensitive adhesive ( Hereinafter referred to as "the present releasable adhesive"). The present releasable adhesive is By applying the heat, the unsaturated groups in the release adhesive are polymerized, and the release adhesive is hardened. The adhesive strength is reduced, and the adhesive exhibits peelability.

[0142] <Removable adhesive> The present releasable pressure-sensitive adhesive is suitably used as a pressure-sensitive adhesive layer of a releasable pressure-sensitive adhesive sheet, The above-mentioned releasable pressure-sensitive adhesive sheet is a releasable sheet containing the releasable pressure-sensitive adhesive of the present invention on one or both sides of a supporting substrate. It is preferable that the adhesive layer has excellent transparency and adhesive strength relative to the thickness of the adhesive layer. In view of the high performance, it is also preferable to use a substrate-less double-sided PSA sheet that does not have a supporting substrate. The peelable adhesive sheet will now be described.

[0143] In the present invention, the term "sheet" includes "film" and "tape." This is what is written.

[0144] <Removable adhesive sheet> A peelable adhesive sheet according to one embodiment of the present invention (hereinafter referred to as "the peelable adhesive sheet") can be produced according to a known general method for producing a peelable pressure-sensitive adhesive sheet, for example, It can be manufactured in the street. The present peelable pressure-sensitive adhesive composition may be applied as is or with the concentration adjusted with an appropriate organic solvent to a release filter. The film is then applied directly onto the release-treated surface of the film or onto the substrate sheet. Dry the sheet by heating at 0.5°C for 0.5 to 10 minutes, and then transfer it to a base sheet or release film. By attaching the adhesive to a film, the present peelable adhesive sheet can be obtained. To achieve a balance, it is also preferable to carry out further aging after drying.

[0145] Examples of the base sheet include polyethylene naphthate and polyethylene terephthalate. Polybutylene terephthalate, polyethylene terephthalate / isophthalate copolymer Polyester resins such as polyethylene, polypropylene, polymethylpentene, etc. Polyolefin resins; polyvinyl fluoride, polyvinylidene fluoride, polyethylene fluoride Polyethylene fluoride resins such as nylon 6, nylon 6,6 and other polyamides; polyvinyl chloride Nyl, polyvinyl chloride / vinyl acetate copolymer, ethylene-vinyl acetate copolymer, ethylene -Vinyl alcohol copolymers, polyvinyl alcohol, vinylon and other vinyl polymers; Cellulose resins such as cellulose acetate and cellophane; polymethyl methacrylate, polymethacrylate acrylic resins such as ethyl acrylate, polyethyl acrylate, and polybutyl acrylate; Synthetic resin sheets such as styrene, polycarbonate, polyarylate, polyimide, etc., aluminum Aluminum, copper, iron metal foil, fine paper, glassine paper, glass fiber, natural fiber, synthetic fiber, etc. These substrate sheets can be used as a single layer or as a mixture of two or more layers. It can be used as a laminated body with the top layer laminated. Synthetic resin sheets are preferred, and polyester resins and polyolefin resins are particularly preferred. It's nice.

[0146] Furthermore, the release film may be made of, for example, any of the synthetic resins exemplified above for the base sheet. Sheets, paper, woven fabrics, nonwoven fabrics, etc. that have been subjected to a release treatment can be used.

[0147] The method for applying the peelable pressure-sensitive adhesive composition is not particularly limited as long as it is a general application method. For example, roll coating, die coating, gravure coating, etc. Examples of methods include coating, comma coating, and screen printing.

[0148] When forming a thick adhesive layer, apply the adhesive to the release-treated surface of the release film. The peelable adhesive composition whose viscosity has been adjusted by the above-mentioned method is directly applied and dried to form an adhesive layer. Two or more release films are manufactured, and the adhesive layers of the two release film peeling materials with adhesive layers are bonded to each other. They can also be stuck together to form a thick adhesive layer.

[0149] The thickness of the adhesive layer of the peelable adhesive sheet is usually preferably 10 to 200 μm. The thickness is preferably 15 to 100 μm.

[0150] In order to give the present peelable adhesive sheet further unevenness conformability and extensibility, A soft intermediate layer may be placed between the substrate layer and the adhesive layer.

[0151] The thickness of the adhesive layer was determined using a Mitutoyo "ID-C112B" peelable adhesive. Subtract the thickness measurement of components other than the adhesive layer from the thickness measurement of the entire sheet. The value is calculated by

[0152] The aging conditions are usually room temperature (23°C) to 70°C, and the time is usually For example, 1 to 30 days at 23°C for 1 to 20 days, or 3 to 10 days at 23°C for 3 to 10 days. The incubation may be carried out under conditions such as 40°C for 1 to 10 days.

[0153] The gel fraction of the adhesive layer of this peelable adhesive sheet before energy application is important for durability and adhesive strength. From this viewpoint, it is preferably 20% or more, particularly preferably 30 to 99%, and further preferably If the gel fraction is too low, the cohesive force decreases, resulting in a decrease in durability. However, if the gel fraction is too high, there is a concern that the adhesive strength will decrease due to an increase in cohesive force. There is.

[0154] In addition, the gel fraction of the adhesive layer of the present peelable adhesive sheet after application of energy is It is preferably 70% or more, particularly preferably 80% or more, and further preferably 90% or more. If the gel fraction is too low, the cohesive strength will decrease, which will increase the adhesive strength and cause peeling. The upper limit of the gel fraction is usually 100%.

[0155] The gel fraction is a measure of the degree of crosslinking and is calculated, for example, by the following method. That is, the base polymer sheet (for example, polyethylene terephthalate film, etc.) A peelable adhesive sheet having a peelable adhesive layer formed thereon (without a separator) The sample was wrapped in a 200-mesh SUS wire netting, immersed in toluene at 23°C for 24 hours, and then The weight percentage of the undissolved adhesive component remaining in the adhesive layer is the gel fraction. Subtract it.

[0156] The peelable pressure-sensitive adhesive sheet thus obtained exhibits high adhesive strength when applied to an adherend, The surface of the adherend can be protected, and by applying energy after the treatment step, As a result, the ethylenically unsaturated groups contained in the releasable adhesive layer are polymerized, and the releasable adhesive layer is hardened. Since the adhesive strength can be reduced, the adhesive can be easily peeled off and the adhesive can be easily peeled off from the adherend. No adhesive residue is left when removed.

[0157] The above energy includes far ultraviolet rays, ultraviolet rays, near ultraviolet rays, infrared rays, X-rays, and gamma rays. In addition to electromagnetic waves such as those mentioned above, electron beams, proton beams, and neutron beams can also be used, but the curing speed and irradiation equipment vary. Curing by ultraviolet irradiation is advantageous in terms of availability, price, etc. In this case, curing is possible without using the photopolymerization initiator (C1).

[0158] The light source for the ultraviolet irradiation may be a high-pressure mercury lamp, an electrodeless lamp, or an ultra-high pressure water lamp. Silver lamp, carbon arc lamp, xenon lamp, metal halide lamp, chemical lamp, black In the case of the high-pressure mercury lamp, for example, 5 to 30 00mJ / cm 2 , preferably 50 to 2000 mJ / cm 2 The above conditions are also met. For electrodeless lamps, for example, 2 to 2000 mJ / cm 2 , preferably 10 to 1000 mJ / cm 2 The irradiation time is determined by the type of light source and the distance between the light source and the coated surface. Although it depends on the separation, coating thickness, and other conditions, it usually takes several seconds to several tens of seconds, and in some cases On the other hand, in the case of the electron beam irradiation, for example, 50 to 1000 Kev It is preferable to use an electron beam having an energy in the range of 2 to 50 Mrad.

[0159] The adhesive strength (α) of the releasable adhesive layer of the releasable adhesive sheet is appropriately adjusted depending on the material of the adherend. For example, silicon wafers, glass substrates, polycarbonate plates, polymethyl When attaching to a methacrylate plate, a PET sheet with an ITO layer deposited, or a metal plate, The adhesive strength immediately after application is preferably 0.2 to 500 N / 25 mm, and particularly preferably 0. 5~100N / 25mm.

[0160] The adhesive strength (α) can be measured, for example, as follows. This peelable adhesive sheet was attached to a SUS-BA substrate and left at 23°C, 50% RH for 30 minutes. After leaving it for more than 1 minute, the 180-degree peel strength (N / 25mm) was measured according to JIS Z0237. ) is measured.

[0161] In addition, the adhesive strength (β) of the releasable adhesive layer of this releasable adhesive sheet after application of energy is 2 N / 25mm or less, preferably 1.5N / 25mm or less, particularly preferably 1N / 25mm or less The adhesive strength (β) is preferably 0.7 N / 25 mm or less, and more preferably 0.7 N / 25 mm or less. If it is too large, the removability tends to be poor, it becomes difficult to peel off, and adhesive residue tends to remain. The lower the lower limit of adhesive strength (β), the better. 0.0001N / 25mm, preferably 0.001N / 25mm, particularly preferably It is 0.01N / 25mm.

[0162] The adhesive strength (β) can be measured, for example, as follows. This peelable adhesive sheet was attached to a SUS-BA plate as the adherend and left at 23°C and 50% RH for 3 After leaving it for more than 10 minutes, it was irradiated with ultraviolet light (500mJ / cm from a high-pressure mercury lamp). 2 ) was performed. After that, the 180-degree peel strength (N / 25 mm) is measured in accordance with JIS Z0237.

[0163] In addition, the adhesive strength after energy application is 1 / 3 or less of the adhesive strength before energy application. It is preferable that the ratio is 1 / 10 or less, and more preferable that the ratio is 1 / 10 or less.

[0164] This peelable pressure-sensitive adhesive sheet has excellent adhesive strength to adherends, and when peeled off, it releases an active energy. By irradiating the adhesive with high energy rays, it adheres smoothly and without leaving any adhesive residue when peeled off from the adherend. For example, semiconductor wafers, circuit boards such as FPC boards, and ITO transparent electrodes As a temporary surface protection adhesive sheet to temporarily protect the surface of the electrode layer, or during the manufacturing process It is used as a temporary adhesive sheet to temporarily hold and reinforce products. It is possible. [Example]

[0165] The present invention will be explained in more detail below with reference to examples, but the present invention does not exceed the gist of the present invention. The present invention is not limited to the following examples. In the examples, "parts" and "%" indicate weights. It means a quantity standard.

[0166] [Production of Polyester Resin (A1-1)] A reactor equipped with a heater, thermometer, stirrer, rectification column, nitrogen inlet tube and vacuum device was installed. As carboxylic acids, 9.6 parts (0.2 moles) of isophthalic acid and 46.8 parts of sebacic acid (0.8 mol), as polyhydric alcohol, 27.1 parts of neopentyl glycol (0.9 mol), 1,4-butanediol 13.0 parts (0.5 moles), 1,6-hexanediol 3 0.0 part (0.087 moles) and 0.5 parts (0.013 moles) of trimethylolpropane, 0.01 parts of tetrabutyl titanate was added as a catalyst, and the internal temperature was gradually increased to 250°C. The internal temperature was then increased to 260°C, and the esterification reaction was carried out for 4 hours. 0.01 parts of tetrabutyl titanate was added, the pressure was reduced to 1.33 hPa, and the mixture was stirred for 3 hours. The polymerization reaction was carried out over a period of 1 hour to produce a polyester resin (A1-1). The resin composition (molar ratio) of the obtained polyester resin (A1-1) was: isophthalic acid / ceramide Basic Acid / Neopentyl Glycol / 1,4-Butanediol / 1,6-Hexanediol ethanol / trimethylolpropane = 0.2 / 0.8 / 0.59 / 0.34 / 0.06 / 0.0 It was 1. The ester group concentration of the polyester resin (A1-1) was 7.7 mmol / g, and the crystalline The heat of fusion is 0 J / g, the weight average molecular weight is 81,000, the number average molecular weight is 18,000, and the peak The molecular weight of the polymer is 69,000, the glass transition temperature (Tg) is -49°C, and the acid value is 0.02mg / K.O. The hydroxyl value was 10.0 mgKOH / g.

[0167] [Production of Polyester Resin (A1-2)] A reactor equipped with a heater, thermometer, stirrer, rectification column, nitrogen inlet tube and vacuum device was installed. As carboxylic acids, 9.6 parts (0.2 moles) of isophthalic acid and 46.8 parts of sebacic acid (0.8 mol), as polyhydric alcohol, 27.1 parts of neopentyl glycol (0.9 mol), 1,4-butanediol 13.0 parts (0.5 moles), 1,6-hexanediol 3 0.0 part (0.087 moles) and 0.5 parts (0.013 moles) of trimethylolpropane, 0.01 parts of tetrabutyl titanate was added as a catalyst, and the internal temperature was gradually increased to 250°C. The internal temperature was then increased to 260°C, and the esterification reaction was carried out for 4 hours. 0.01 parts of tetrabutyl titanate was added, the pressure was reduced to 1.33 hPa, and the mixture was stirred for 3 hours. The polymerization reaction was carried out over a period of 1 hour, and the pressure was returned to normal, and 0.75 parts of trimethylolpropane was added. The mixture was then reacted at 240° C. for 3 hours to produce a polyester resin (A-2). The resin composition (molar ratio) of the obtained polyester resin (A1-2) was: isophthalic acid / ceramide Basic Acid / Neopentyl Glycol / 1,4-Butanediol / 1,6-Hexanediol ethanol / trimethylolpropane = 0.2 / 0.8 / 0.59 / 0.34 / 0.06 / 0.0 It was 3. The ester group concentration of the polyester resin (A1-2) was 7.7 mmol / g, and the crystalline The heat of fusion is 0 J / g, the weight average molecular weight is 49,000, the number average molecular weight is 10,000, and the peak The molecular weight of the polymer is 38,000, the glass transition temperature (Tg) is -49°C, and the acid value is 0.02mg / K.O. The hydroxyl value was 24.5 mgKOH / g.

[0168] The polymer compositions and properties of the obtained polyester resins (A1-1) and (A1-2) were as follows: The properties are shown in Table 1 below. The methods for measuring each property are as follows.

[0169] <Weight average molecular weight, number average molecular weight, peak top molecular weight> The weight average molecular weight, number average molecular weight, and peak top molecular weight are calculated using standard polystyrene molecules. The average molecular weight is calculated by the mass conversion, and is analyzed by high performance liquid chromatography (Nihon Waters, "Waters 2695 (Separation Module)" and "Waters 2414 (detector)), column: Shodex GPC KF-806L (exclusion limit molecular weight: 2×10 7 Separation range: 100 to 2 × 10 7 Theoretical plate number: 10,000 plates / unit, Packing material: Three styrene-divinylbenzene copolymers (filler particle size: 10 μm) were connected in series and measured. Ta.

[0170] <Glass transition temperature (Tg)> The test piece is heated and cooled from room temperature at a rate of 10°C / min, and the heat is measured using a differential scanning calorimeter. Measure the amount of heat and draw two extension lines on the endothermic or exothermic curve. The temperature at the intersection of the heat curve or exothermic curve was taken as the glass transition temperature.

[0171] [Table 1]

[0172] Prior to the examples, the following ingredients were prepared:

[0173] [Compound (B) containing an ethylenically unsaturated group and an isocyanate group] (B-1): Compound "PR-9000" (manufactured by BASF) represented by the following general formula (2) TIFF2026012471000004.tif48150[Polymerization initiator (C)] Photopolymerization initiator (C-1): "Omnirad184" (IGM Resins B.V.) Company) [Hydrolysis inhibitor (D)] Carbodiimide compound (D-1): "Carbodilite V-09GB" (Nisshinbo Chemical Co., Ltd.) (manufactured by Lexus) [Urethanization catalyst] Zirconium compound: "Orgatics ZC-150" (Matsumoto Fine Chemical) (manufactured by the company) diluted with acetylacetone to a solids concentration of 1% [Antioxidants] Hindered phenolic antioxidant: "Irganox 1010" (BASF) [Other crosslinking agents] Isocyanate crosslinking agent: "Coronate L55E" (Tosoh Corporation)

[0174] [Production of active energy ray-curable compound (E)] A four-necked round-bottom flask equipped with a reflux condenser, a stirrer, a nitrogen gas inlet, and a thermometer was , isophorone diisocyanate (IPDI) 6.6 parts, dipentaerythritol pentaerythritol Acrylate 93.4 parts, di-t-butylhydroxyphenol 0.03 parts, dibutyltin 0.02 parts of dilaurate was added, and the reaction was continued at 50°C to form an active energy ray curable compound. The weight average molecular weight of the active energy ray-curable compound (E-1) was 15. It was 00.

[0175] <Examples 1 to 4, Comparative Examples 1 and 2> Each component was mixed in the amounts shown in Table 2 below and diluted with ethyl acetate and / or toluene. Dilute to a coatable viscosity (1000-5000 mPa·s / 25°C) to form a peelable adhesive composition Using this release adhesive composition, a release adhesive film was prepared by the following method. A release adhesive sheet was prepared.

[0176] [Table 2]

[0177] [Preparation of Peelable Adhesive Sheet] A polyethylene terephthalate (PET) film (thickness 38 μm) was prepared as the substrate. The peelable pressure-sensitive adhesive composition is dried on the surface of the PET film while ultraviolet light is blocked. After applying the adhesive to a thickness of 25 μm, it was dried at 100°C for 2 minutes. The adhesive layer is protected by a release-treated PET film. An adhesive sheet (thickness: 25 μm) was obtained. In addition, a release-treated polyethylene terephthalate (PET) film (thickness 38 μm) ) and, with ultraviolet rays blocked, apply the above-mentioned release-treated PET film surface with The peelable adhesive composition was applied so that the thickness after drying was 50 μm, and then heated at 100° C. for 5 minutes. After that, a release-treated PET film was attached to the surface of the adhesive layer to protect it. Thus, a double-sided release PET-attached peelable adhesive sheet (thickness: 50 μm) was obtained.

[0178] The peelable adhesive sheets of the Examples and Comparative Examples thus obtained were cured at 40°C for 7 days. After that, various physical properties were evaluated according to the following methods, and the results are shown in Table 3 below. The release-treated PET sheet was peeled off when various measurement tests were carried out.

[0179] <Gel fraction> The peelable adhesive sheet (thickness: 25 μm) obtained above was passed through a 200 mesh SUS wire mesh. The wire mesh was then wrapped in a plastic bag and immersed in toluene at 23°C for 24 hours. The gel fraction was determined as the percentage of the amount of the gel. The gel fraction was also measured in the same manner after ultraviolet irradiation. The weight of the substrate was subtracted.

[0180] <Adhesion strength before UV irradiation> The peelable adhesive sheet (thickness: 25 μm) obtained above was attached to the SUS-BA plate as the adherend. After leaving it for 30 minutes or more at 23°C and 50% RH, the 180° peel strength (N / 25 mm) was measured.

[0181] <Adhesive strength after UV irradiation> The peelable adhesive sheet (thickness 25 μm) obtained above was attached to the SUS-BA plate as the adherend. After leaving it at 23°C and 50% RH for 30 minutes or more, it was irradiated with ultraviolet light (high pressure mercury lamp) 500mJ / cm 2 ) and then tested for 180-degree peel strength ( N / 25mm) was measured.

[0182] <Holding force (cohesive force)> The peelable adhesive sheet (thickness: 25 μm) obtained above was subjected to a peeling test in accordance with JIS Z-0237. The adhesive was applied to SUS304 with an area of ​​25mm x 25mm, and then left at 40°C for 20 minutes. After that, a 1 kg load was applied and the time until the load fell was evaluated according to the following criteria: Ta. (Evaluation criteria) ○...It did not fall off even after being left standing for 24 hours. ×: The sample fell off after being left standing for 24 hours.

[0183] [Preparation of samples for elongation and breaking stress] The peelable adhesive sheet (thickness 50 μm) obtained above was irradiated with ultraviolet light of 365 nm wavelength. Radiation intensity 200mW / cm 2 , cumulative light intensity 500mJ / cm 2 Irradiate under conditions that result in hardening. The hardened peelable adhesive sheet was punched out with a dumbbell to form a sheet 15 cm wide and 75 cm long. After preparing a rectangular sample so that the thickness is 1 mm, the PET film on both sides is peeled off and the sample is measured. The sample pieces were used for the test.

[0184] <Elongation (%)> The measurement sample obtained above was subjected to a tensile test using the AG tensile tester at 23°C and 50% RH. A tensile test was conducted in accordance with JIS K 7127 using a Shimadzu SUS304-X. The pulling speed was 10 mm / min, and the elongation at the breaking point was measured.

[0185] < Breaking stress (N / mm 2 )> The measurement sample obtained above was subjected to a tensile test using the AG tensile tester at 23°C and 50% RH. A tensile test was conducted in accordance with JIS K 7127 using a Shimadzu SUS304-X. The pulling speed was 10 mm / min, and the strength at the breaking point was measured.

[0186] [Table 3]

[0187] The releasable pressure-sensitive adhesive sheets of Examples 1 to 4 prepared from the releasable pressure-sensitive adhesive composition of the present invention were The adhesive strength was low enough that it could be peeled off after irradiation, and it had excellent peelability and high elongation. This is thought to result in less adhesive residue. On the other hand, by blending a crosslinking agent and an active energy ray curing compound, the adhesiveness after UV irradiation is improved. The releasable pressure-sensitive adhesive sheet produced from the releasable pressure-sensitive adhesive composition of Comparative Example 1, which exhibited a decrease in adhesive strength, was exposed to ultraviolet light. After irradiation, the cohesive strength became too high and the elongation was low. This caused the adhesive layer to break. It is expected that the adhesive will be easily damaged and leave a large amount of adhesive residue. Furthermore, a peelable adhesive composition prepared from the peelable adhesive composition of Comparative Example 2, which does not contain an ethylenically unsaturated group, was used. The peelable adhesive sheet had high adhesive strength after exposure to ultraviolet light, making it difficult to peel off. [Industrial Applicability]

[0188] The removable adhesive composition of the present invention exhibits a certain level of adhesive strength at the beginning and, upon peeling, The adhesive strength is very low, so it holds firmly when fixed and peels off easily when removed. Moreover, it has the property of being extremely stretchable even when hardened by ultraviolet light, etc. The adhesive layer does not physically catch on uneven surfaces such as bumps. Even if the adhesive is broken, it is difficult to tear and does not leave adhesive residue. Therefore, processed materials such as electronic substrates, semiconductor wafers, processed glass products, metal plates, plastic plates, etc. It is preferably used as an adhesive layer of an adhesive sheet to temporarily protect the surface when processing a member. More specifically, circuit patterns having bumps on semiconductor wafers with uneven surfaces are also suitable. It can be very useful as an adhesive layer to temporarily protect the forming surface. be.

Claims

1. A peelable pressure-sensitive adhesive composition comprising an adhesive resin (A) and a compound (B) containing an ethylenically unsaturated group and an isocyanate group, the adhesive resin (A) is at least one selected from the group consisting of a rubber-based resin, a polyester-based resin, a urethane-based resin, and a silicone-based resin, each having a hydroxyl group at a main chain terminal; A peelable pressure-sensitive adhesive composition, characterized in that the compound (B) containing an ethylenically unsaturated group and an isocyanate group is a polyisocyanate containing a (meth)acryloyl group and two or more isocyanate groups in its side chain.

2. 2. The peelable pressure-sensitive adhesive composition according to claim 1, wherein the pressure-sensitive adhesive resin (A) is a polyester resin.

3. 3. The peelable pressure-sensitive adhesive composition according to claim 1, wherein the pressure-sensitive adhesive resin (A) is a polyester resin having a weight-average molecular weight of 10,000 or more.

4. 4. The peelable pressure-sensitive adhesive composition according to claim 1, wherein the pressure-sensitive adhesive resin (A) does not have an unsaturated group.

5. The peelable pressure-sensitive adhesive composition according to any one of claims 1 to 4, characterized in that the content of the compound (B) containing an ethylenically unsaturated group and an isocyanate group is 0.1 to 50 parts by weight per 100 parts by weight of the pressure-sensitive adhesive resin (A).

6. The peelable pressure-sensitive adhesive composition according to any one of claims 1 to 5, further comprising a polymerization initiator (C).

7. A peelable pressure-sensitive adhesive comprising the peelable pressure-sensitive adhesive composition according to any one of claims 1 to 6.

8. A releasable adhesive sheet comprising a substrate and at least one adhesive layer containing the releasable adhesive of claim 7 laminated thereon.

9. 9. The peelable adhesive sheet according to claim 8, wherein the adhesive strength (J) of the peelable adhesive sheet is 2 N / 25 mm or less. Adhesion strength (J): The peelable adhesive sheet was attached to an SUS-BA plate as an adherend, and left to stand at 23, 50% RH for 30 minutes or more, and then irradiated with ultraviolet light (500 mJ / cm using a high-pressure mercury lamp). 2 ) and then the 180-degree peel strength (N / 25 mm) after ultraviolet irradiation was measured in accordance with JIS Z0237.

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