Polyester-based pressure-sensitive adhesive composition, polyester-based pressure-sensitive adhesive, and pressure-sensitive adhesive sheet

Abstract

To provide a polyester-based adhesive composition which is excellent in adhesive force (initial adhesive force) immediately after bonding and is further excellent in shear force, when formed into an adhesive.SOLUTION: A polyester-based adhesive composition contains a polyester-based resin (A) having a structural unit derived from polyvalent carboxylic acids (a1) and a structural unit derived from polyol (a2), and a polyester-based plasticizer (B), wherein the polyester-based plasticizer (B) has a structural unit derived from polyvalent carboxylic acids (b1), a structural unit derived from polyol (b2) and a structural unit derived from a reactive molecule terminal sealing agent (b3), and a glass transition temperature (TgA) of the polyester-based resin (A) is -25 to 35°C.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyester-based pressure-sensitive adhesive composition, a polyester-based pressure-sensitive adhesive, and a pressure-sensitive adhesive sheet. More specifically, polyesters that have excellent initial adhesive strength and shear strength when used as adhesives. -based adhesive composition, polyester-based adhesive, adhesive sheet, and double-sided adhesive sheet is. [Background technology]

[0002] Conventionally, polyester resins are produced by combining a polycarboxylic acid component and a polyol component. It is known that this results in excellent chemical resistance, plasticizer resistance, mechanical strength, etc. It is also being considered in the field of pressure-sensitive adhesives (adhesives).

[0003] In recent years, with the miniaturization and thinning of parts and components, adhesives have also become more difficult to apply even over a small area. For example, in Patent Document 1, a method for improving adhesive strength is described. In the past, a polyester-based pressure-sensitive adhesive composition containing a polyester-based resin and a tackifier was proposed. There are. In Patent Document 2, a polyester resin containing a polyester resin and a fatty acid ester is disclosed. Ester-based pressure-sensitive adhesive compositions have been proposed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-169419 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-196822 Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology disclosed in Patent Document 1, a tackifier with a high softening point such as a rosin ester or a terpene resin is used. Generally, a tackifier with a high softening point is added to give cohesive strength at high temperatures. However, such tackifiers tend to reduce the initial adhesive strength at room temperature. Therefore, there were still issues with the adhesive strength and shear strength immediately after lamination.

[0006] In addition, the technology disclosed in Patent Document 2 blends a fatty acid ester into a polyester resin. Although fatty acid esters can impart wettability to the adherend, they are low molecular weight components and therefore do not coagulate. It had poor collection power and had issues with adhesion and shear strength.

[0007] Therefore, in the present invention, under such circumstances, when an adhesive is used, the adhesive strength immediately after lamination is To provide a polyester-based pressure-sensitive adhesive composition having excellent initial adhesive strength and shear strength. The purpose is to: [Means for solving the problem]

[0008] However, the present inventors have conducted extensive research in light of the above circumstances and have found that polycarboxylic acids ( Polyesters containing structural units derived from a1) and structural units derived from polyol (a2) In the pressure-sensitive adhesive composition containing resin (A), a polyester resin having a high glass transition temperature is used. By using (A) in combination with polyester plasticizer (B), the initial viscosity of the adhesive can be improved. It has been found that a polyester-based pressure-sensitive adhesive composition having excellent adhesion and shear strength can be obtained, The present invention has been completed.

[0009] That is, the gist of the present invention is the following [1] to

[15] . [1] Structural units derived from polycarboxylic acids (a1) and structures derived from polyols (a2) A polyester resin (A) having a polyester unit and a polyester plasticizer (B) The polyester-based pressure-sensitive adhesive composition, wherein the polyester-based plasticizer (B) is a polycarboxylic acid A structural unit derived from (b1), a structural unit derived from polyol (b2), and a reactive molecular end-capping The polyester resin (A) has a structural unit derived from the chain (b3) and A polyester adhesive characterized by a glass transition temperature (TgA) of -25 to 35°C. composition. [2] The weight average molecular weight of the polyester resin (A) is 15,000 to 200,000 0. The polyester-based pressure-sensitive adhesive composition according to [1]. [3] The polyester resin (A) has an acid value of 5 mg KOH / g or less. The polyester-based pressure-sensitive adhesive composition according to [1] or [2], [4] The polyester-based plasticizer (B) is a structural unit derived from a polycarboxylic acid (b1). At least one structural unit derived from polyol (b2) and one structural unit derived from reactive molecular end-capping agent (b3) [1] to [3], characterized in that any one of them contains an aromatic structure. The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 14. [5] The weight average molecular weight of the polyester plasticizer (B) is 1,000 to 12,000. The polyester-based pressure-sensitive adhesive composition according to any one of [1] to [4], Finished product. [6] The content of the polyester plasticizer (B) is 100% of the polyester resin (A). Any of [1] to [5], characterized in that the amount is 0.1 to 180 parts by weight based on the total weight of the compound. The polyester-based pressure-sensitive adhesive composition according to claim 1. [7] The acid value of the polyester plasticizer (B) is 5 mg KOH / g or less. The polyester-based pressure-sensitive adhesive composition according to any one of [1] to [6] above, characterized in that: [8] The glass transition temperature (TgB) of the polyester plasticizer (B) is -80 to 0°C. The polyester-based pressure-sensitive adhesive composition according to any one of [1] to [7], wherein: [9] The glass transition temperature (TgA) of the polyester resin (A) is [1] to [8], characterized in that the glass transition temperature (TgB) of the plasticizer (B) is higher than that of the plasticizer (B). The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 14.

[10] Any of [1] to [9], characterized in that it contains a hydrolysis inhibitor (C). The polyester-based pressure-sensitive adhesive composition according to claim 1.

[11] The composition according to any one of [1] to

[10] , characterized in that it contains a crosslinking agent (D). A polyester-based pressure-sensitive adhesive composition.

[12] The polyester-based pressure-sensitive adhesive composition according to any one of [1] to

[11] is crosslinked. A polyester-based pressure-sensitive adhesive characterized by:

[13] A pressure-sensitive adhesive layer containing the polyester-based pressure-sensitive adhesive according to

[12] . An adhesive sheet.

[14] A pressure-sensitive adhesive layer obtained from the polyester-based pressure-sensitive adhesive according to

[12] and a substrate. A pressure-sensitive adhesive sheet, wherein the pressure-sensitive adhesive layer is provided on at least one surface of the substrate. The adhesive sheet is characterized.

[15] A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer containing the polyester-based pressure-sensitive adhesive according to

[12] . The pressure-sensitive adhesive sheet is characterized by being a substrate-less type that does not have a substrate.

[0010] In general, a tackifier is blended into a pressure-sensitive adhesive to improve shear strength. In this case, a resin with a low glass transition temperature and adhesiveness is used as the main agent to further increase the cohesive strength. However, in the present invention, a tackifying resin with a high softening point is usually blended to enhance the viscosity. a polyester resin having a specific glass transition temperature, and a repeating polymer having an ester bond; By blending a polyester plasticizer with a repeating structural unit, the main agent It has excellent compatibility with other adhesives, does not bleed, and has excellent initial adhesive strength when used as an adhesive. Furthermore, a pressure-sensitive adhesive composition having excellent shear strength can be obtained. [Effects of the Invention]

[0011] The polyester-based pressure-sensitive adhesive composition of the present invention has excellent initial adhesive strength and shear strength when used as a pressure-sensitive adhesive. It has excellent effects and is particularly useful as an adhesive for electronic components. DETAILED DESCRIPTION OF THE INVENTION

[0012] The configuration of the present invention will be described in detail below, but these are examples of preferred embodiments. It is something.

[0013] The polyester-based pressure-sensitive adhesive composition of the present invention comprises a polyester-based resin (A), a polyester-based A polyester-based pressure-sensitive adhesive containing a plasticizer (B), comprising a polyester-based resin (A) represents a structural unit derived from a polycarboxylic acid (a1) and a structural unit derived from a polyol (a2). and a glass transition temperature (TgA) of -25 to 35°C, and a polyester-based plasticizer (B). is a structural unit derived from a polycarboxylic acid (b1), a structural unit derived from a polyol (b2), and and a structural unit derived from the reactive molecular end-capping agent (b3). Each of the constituent components used in the polyester-based pressure-sensitive adhesive composition of the present invention will be described in detail below. .

[0014] <Polyester resin (A)> The polyester resin that can be used in the present invention usually contains polyvalent calcium carbonate as a constituent material. The copolymerization components containing the polyol (a1) and the polyol (a2) are copolymerized. The polyester resin contains, as its resin composition, a polycarboxylic acid (a1)-derived copolymer. The polyester (a1) has structural units derived from the above-mentioned polyester (a2) and structural units derived from the polyol (a3). The terephthalate resin is a polyol having a structural unit derived from a polycarboxylic acid (a1) and a structural unit derived from a polyol (a2). In view of excellent shear strength, it is preferable that at least one of the structural units contains an aromatic structural unit. It is preferable that the structural unit derived from the polycarboxylic acid (a1) has an aromatic structural unit. Preferred. In the present invention, the term "carboxylic acids" includes not only carboxylic acids but also carboxylic acids Carboxylic acid derivatives such as salts, carboxylic acid anhydrides, carboxylic acid halides, and carboxylic acid esters It also includes conductors.

[0015] [Structural units derived from polycarboxylic acids (a1)] Examples of the structural unit derived from the polycarboxylic acid (a1) include those derived from dicarboxylic acids. and structural units derived from trivalent or higher polyvalent carboxylic acids. In terms of stably obtaining the resin, it is preferable that the resin contains a structural unit derived from a dicarboxylic acid. The polycarboxylic acids (a1) may be used alone or in combination of two or more. .

[0016] Examples of the structural units derived from the dicarboxylic acids include malonic acids, dimethyl malonic acids, and the like. Acids, succinic acids, glutaric acids, adipic acids, trimethyl adipic acids, pimelic acid 2,2-dimethylglutaric acids, azelaic acids, sebacic acids, fumaric acids, maleic diglycolic acids, 1,9-nonanediol, itaconic acids, thiodipropionic acids, diglycolic acids, Structural units derived from aliphatic dicarboxylic acids such as carboxylic acids; Phthalic acids, terephthalic acids, isophthalic acids, benzylmalonic acids, diphenic acids, 4,4'-oxydibenzoic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, Naphthalenedicarboxylic acids such as phthalenedicarboxylic acids and 2,7-naphthalenedicarboxylic acids Structural units derived from aromatic dicarboxylic acids such as carboxylic acids; 1,3-Cyclopentanedicarboxylic acids, 1,2-Cyclohexanedicarboxylic acids, 1 ,3-cyclopentanedicarboxylic acids, 1,4-cyclohexanedicarboxylic acids, 2,5 Alicyclic dicarboxylic acids such as norbornanedicarboxylic acids and adamantanedicarboxylic acids structural units of origin; Dimer acids (carbon dimers) derived from oleic acid, linoleic acid, linolenic acid, erucic acid, etc. Structural units derived from aryl groups (mainly those with numbers 36 to 44); etc. In addition, examples of the structural units derived from the trivalent or higher polyvalent carboxylic acids include trimellitates. Structures derived from methyltricarboxylic acids, pyromellitic acids, adamantanetricarboxylic acids, trimesic acids, etc. Examples include manufacturing units. These structural units derived from polycarboxylic acids (a1) may be contained alone or in combination of two or more. It's fine.

[0017] Among the structural units derived from the polycarboxylic acids (a1), the crystalline structure of polyester resins is In terms of reducing the viscosity and providing excellent cohesive strength, structural units derived from aromatic polycarboxylic acids, particularly It is preferable to contain a structural unit derived from an asymmetric aromatic dicarboxylic acid (a1-1), Examples of structural units derived from asymmetric aromatic dicarboxylic acids (a1-1) include phthalic acid , isophthalic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids Examples of structural units include those derived from carboxylic acids and 2,7-naphthalenedicarboxylic acids. In terms of reactivity, it is particularly preferred that the copolymer contains structural units derived from isophthalic acids.

[0018] Such structural units derived from aromatic polycarboxylic acids, particularly asymmetric aromatic dicarboxylic acids The content of the structural units derived from (a1-1) is the total of the structural units derived from the polycarboxylic acids (a1). It is preferably 5 to 100 mol %, more preferably 10 to 95 mol %, and even more preferably 10 to 95 mol %. More preferably, it is 20 to 90 mol %, particularly preferably 40 to 85 mol %, and particularly preferably 6 If the content is too low, the shear force may decrease and the polyester may become weak. The ester resin tends to crystallize, making it difficult to obtain sufficient adhesive properties. If the content is too high, the initial adhesive strength tends to decrease.

[0019] In the present invention, the structural unit derived from the polycarboxylic acid (a1) is From the viewpoint of improving the strength, aliphatic dicarboxylic acids with 4 or more carbon atoms (including the carbon atom of the carboxyl group) are used. It is preferable that the compound contains a structural unit derived from a carboxylic acid (a1-2), and among them, it is preferable that the compound contains a structural unit derived from a carboxylic acid (a1-2) having a carbon number (carbon It is more preferable that the dicarboxylic acid contains an aliphatic dicarboxylic acid having 6 to 12 carbon atoms (including the carbon atoms of the oxy group), It is particularly preferred that the copolymer contains structural units derived from adipic acids, sebacic acids, or azelaic acids. It's nice.

[0020] The content of structural units derived from such aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms is The content of the structural units derived from the polycarboxylic acids (a1) is 5 to 90 mol %. is preferable, more preferably 10 to 80 mol %, and even more preferably 15 to 60 mol %, The content is particularly preferably 20 to 40 mol %. If the content is too low, the polyester resin If the glass transition temperature of the oil becomes too high, the initial adhesive strength tends to decrease. The shear strength decreases, or the polyester resin crystallizes and the adhesive performance becomes insufficient. There is a tendency for this to happen.

[0021] In the present invention, from the viewpoint of adhesive properties, the structural unit derived from the polycarboxylic acid (a1) is and structural units derived from asymmetric aromatic dicarboxylic acids (a1-1) and those having 4 or more carbon atoms. It is also preferred that the copolymer contains structural units derived from aliphatic dicarboxylic acids (a1-2). A structural unit derived from an asymmetric aromatic dicarboxylic acid (a1-1) and an aliphatic dicarboxylic acid having 4 or more carbon atoms The content ratio (molar ratio) of the structural unit derived from the carboxylic acid (a1-2) is (a1-1) / ( a1-2) is preferably 1 / 99 to 99 / 1, and more preferably 40 / 60 to 9 0 / 10, and more preferably 55 / 45 to 80 / 20.

[0022] In the present invention, in order to increase the branching points in the polyester resin, trivalent or higher hydroxyl groups are used. The polycarboxylic acid (a1-3) may contain structural units derived from the polycarboxylic acid (a1-3). It is preferable that the composition contains a structural unit derived from trimellitic acids, since gelation is relatively unlikely to occur. I wish.

[0023] The content of the structural units derived from the trivalent or higher polyvalent carboxylic acids (a1-3) is The polycarboxylic acid (a1)-derived structure is preferred in that it can increase the cohesive strength when used as an adhesive. It is preferably 10 mol % or less, particularly preferably 0.1 to 5 mol %, especially preferably 10 mol % or less, based on the total structural units. The content is preferably 0.5 to 3 mol %. If the content is too high, the polyester resin During production, gelation tends to occur and the acid value tends to be high.

[0024] [Structural units derived from polyol (a2)] The structural unit derived from the polyol (a2) may be a structural unit derived from a dihydric alcohol, a trihydric or higher alcohol, or The polyol (a2) may be a single or two-component polyol. More than one species can be used in combination.

[0025] Examples of the structural unit derived from the dihydric alcohol include ethylene glycol, diethylene glycol, Ethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol 1,3-propanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol Neopentyl glycol, 2-ethyl-2-butyl-1,3-propanediol 2-ethyl-2-isobutyl-1,3-propanediol, 1,3-butanediol , 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3 -Methyl-1,5-pentanediol, 2,2,4-trimethyl-1,6-hexanediol structural units derived from aliphatic diols such as methyl methyl alcohol; 1,2-Cyclohexanedimethanol, 1,3-Cyclohexanedimethanol, 1,4 -Cyclohexanedimethanol, spiroglycol, tricyclodecane dimethanol, Damantanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, etc. alicyclic diol-derived structural units; 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 include structural units derived from aromatic diols such as oxide adducts. Furthermore, structural units derived from fatty acid esters derived from castor oil, oleic acid, linoleic acid, structural units derived from dimer diols derived from glycerol, linolenic acid, erucic acid, etc. Examples include structural units derived from glycerol monostearate. Examples of the structural unit derived from the trivalent or higher polyol include pentaerythritol. dipentaerythritol, tripentaerythritol, glycerin, trimethylol propane, trimethylolethane, 1,2,4-butanetriol, 1,2,5-pentane Tantriol, 1,2,6-hexanetriol, 1,3,6-hexanetriol, Examples include structural units derived from adamantanetriol. These structural units derived from polyol (a2) may be contained alone or in combination of two or more. stomach.

[0026] In the present invention, the glass transition temperature of the polyester resin is lowered to improve the initial adhesive strength. From the viewpoint of achieving this, a linear aliphatic diol (a2) is used as a structural unit derived from the polyol (a3). 2-1) is preferably contained, and more preferably, it is a structural unit having 2 to 18 carbon atoms. It contains a structural unit derived from a linear aliphatic diol, and particularly preferably contains ethyl Structural units derived from ethylene glycol, 1,4-butanediol, and 1,6-hexanediol It is to contain.

[0027] The content of structural units derived from the linear aliphatic diol (a2-1) is ) is preferably 5 to 100 mol % based on the total structural units derived from is preferably 10 to 95 mol %, more preferably 15 to 90 mol %, and particularly preferably 20 to 80 mol %. If the content is too low, the stable Resin formation tends to be difficult to obtain.

[0028] In addition, among the structural units derived from the polyol (a2), the polyol (a3) ​​has the advantage of being able to break down crystallinity. Therefore, it is believed that the compound contains a structural unit derived from a diol (a2-2) having a hydrocarbon group in the side chain. Such a structural unit derived from a diol (a2-2) having a hydrocarbon group in the side chain is preferred. Examples of suitable glycerides include dipropylene glycol, 2,4-dimethyl-2-ethylhexane-1, ,3-diol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3- Propanediol (neopentyl glycol), 2-methyl-2-ethyl-1,3-propanediol Panediol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2- Isobutyl-1,3-propanediol, 1,3-butanediol, 3-methyl-1,5 -Branched structures such as pentanediol and 2,2,4-trimethyl-1,6-hexanediol The structural units derived from aliphatic diols, such as 1,2-cyclohexanedimethanol and 1, 3-Cyclohexanedimethanol, 1,4-Cyclohexanedimethanol, Spiroglycolic acid Tricyclodecane dimethanol, Adamantanediol, 2,2,4,4-tetramethylpropanediol Structures derived from alicyclic diols with branched structures such as methyl-1,3-cyclobutanediol units, and structural units derived from dimer diols derived from oleic acid, erucic acid, etc. Among these, structural units derived from aliphatic diols having a branched structure are preferred, and 2- Methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol (ne pentyl glycol), and structural units derived from 3-methyl-1,5-pentanediol, preferable.

[0029] The content of the structural unit derived from the diol (a2-2) having a hydrocarbon group in the side chain is It is preferably 5 to 95 mol % based on the total structural units derived from the ol (a2), and more preferably Preferably, it is 10 to 90 mol %, more preferably 15 to 80 mol %, and particularly preferably 20 The content is preferably 30 to 70 mol %, and particularly preferably 30 to 65 mol %. If there is too much, the polyester resin tends to crystallize and it becomes difficult to obtain sufficient adhesive properties. The reaction time tends to be long in the production of fat.

[0030] Furthermore, in the present invention, the polyester resin is provided with a reaction site with the crosslinking agent (D) described below. In order to form a polyol (a2) and to enhance cohesive strength, a trivalent or higher polyol is preferably used as the structural unit derived from the polyol (a2). It is also preferred that the polyol (a2-3) contains a structural unit derived from the trihydric or higher polyol. Among the structural units derived from (a2-3), trimethylolpropane, trimethylolethane Glycerin, Pentaerythritol, 1,2,4-Butanetriol, 1,2,5- Structural units derived from pentanetriol and 1,2,6-hexanetriol are preferred. The inclusion of structural units derived from trimethylolpropane is particularly important in that it is less likely to produce artificial gels. preferable.

[0031] The content of the structural unit derived from the trihydric or higher polyol (a2-3) is It is preferable that the amount of the structural units derived from the group (a2) is 10 mol % or less, and further The content is preferably 0.1 to 5 mol %, more preferably 0.5 to 3 mol %. If the content of structural units derived from polyols with a hydroxyl group of 1 or more is too high, it becomes difficult to manufacture polyester resins. It tends to be difficult.

[0032] Here, the ratio of structural units (composition ratio) derived from each component of the polyester resin is, for example, , can be determined by NMR.

[0033] The polyester resin used in the present invention is a mixture of the above polycarboxylic acid (a1) and polyol (a2). (a2) is appropriately selected within the above content range, and these are subjected to a known method in the presence of a catalyst. It is produced by polycondensation reaction according to the method.

[0034] The blending ratio of the polycarboxylic acids (a1) and the polyol (a2) is as follows: It is preferable that the amount of the polyol (a2) is 1 to 2 equivalents per equivalent of the carboxylic acid (a1), The amount is particularly preferably 1.1 to 1.7 equivalents. If the blending ratio of the polyol (a2) is too low, If the acid value is too high, it tends to be difficult to increase the molecular weight, and if the acid value is too high, the yield tends to decrease. be.

[0035] In the polycondensation reaction, an esterification reaction is carried out first, and then the polycondensation reaction is carried out.

[0036] In such an esterification reaction, a catalyst is usually used. Specifically, for example, tetrahydrofuran Titanium catalysts such as isopropyl titanate and tetrabutyl titanate, antimony trioxide antimony-based catalysts such as tetrahydrofuran, germanium-based catalysts such as germanium dioxide, and zinc acetate catalysts. Examples of catalysts include lead, manganese acetate, and dibutyltin oxide. Among these, the most popular is Benzene because of its balance of high catalytic activity and color. , antimony trioxide, tetrabutyl titanate, germanium dioxide, and zinc acetate are preferred. stomach.

[0037] The amount of the catalyst to be blended is 1 to 10,000 ppm by weight based on the total copolymerization components. is preferable, particularly preferably 10 to 5000 ppm, and further preferably 20 to 3000 ppm. If the blending amount is too small, the polymerization reaction tends to proceed poorly. If the amount is too large, there is no advantage such as shortening the reaction time, and side reactions tend to occur.

[0038] The reaction temperature during the esterification reaction is preferably 200 to 300°C, and particularly preferably The reaction temperature is preferably 210 to 280°C, more preferably 220 to 260°C. If the temperature is too low, the reaction will not proceed sufficiently, and if it is too high, side reactions such as decomposition will occur. In addition, the pressure during the reaction is usually normal pressure.

[0039] After the esterification reaction, a polycondensation reaction is carried out. The reaction conditions for the polycondensation reaction are as follows: Furthermore, the same amount of hydroxybenzoates is added, and the reaction temperature is preferably 220 to 280°C, particularly preferably 23 The reaction temperature should be kept between 0 and 270°C, and the reaction system should be gradually reduced in pressure until the reaction is finally carried out at 5 hPa or less. If the reaction temperature is too low, the reaction tends to proceed insufficiently, and if the reaction temperature is too high, If the temperature is too high, side reactions such as decomposition tend to occur.

[0040] Thus, the polyester resin (A) used in the present invention is obtained.

[0041] The polyester resin (A) described above preferably has the following physical properties.

[0042] The glass transition temperature (TgA) of the polyester resin (A) is, from the viewpoint of adhesive properties, - The temperature must be 25 to 35°C, preferably -20 to 30°C, and more preferably -1 5 to 28°C, more preferably -10 to 26°C, particularly preferably -5 to 24°C, and particularly preferably The glass transition temperature (TgA) is preferably 0 to 22°C, and most preferably 3 to 20°C. By setting the range of the adhesive strength to the range of 100%, it is possible to obtain an adhesive having excellent initial adhesive strength and shear strength, which is the effect of the present invention. can be done. If the glass transition temperature is too high, flexibility will be lost, the initial adhesive strength will decrease, and the adhesive will not adhere even with finger pressure. If the adhesive strength is too low, the shear strength will decrease. There is a tendency for this to happen.

[0043] The glass transition temperature (TgA) of the polyester resin (A) is measured by TA Instruments. This value is measured using a differential scanning calorimeter DSC Q20 manufactured by Lument. The measurement temperature range is −90 to 100° C., and the temperature rise rate is 10° C. / min.

[0044] The glass transition temperature (TgA) of the polyester resin (A) is The glass transition temperature (TgB) of the ester-based plasticizer (B) is higher than that of the ester-based plasticizer (B), which is important in terms of adhesive properties. Furthermore, it is preferable that the glass transition temperature of the polyester resin (A) is higher than that of the polyester plasticizer. The temperature is preferably 3 to 80°C higher than the glass transition temperature of the agent (B), more preferably 5 to 60°C higher. It is more preferable that the temperature is 10 to 50°C higher, and particularly preferable that the temperature is 15 to 45°C higher. Preferred. By setting the content within the above range, a pressure-sensitive adhesive having excellent initial adhesive strength and shear strength can be obtained.

[0045] The weight average molecular weight of the polyester resin (A) is usually 15 in view of the cohesive strength of the adhesive. It is preferably 20,000 to 150,000, and more preferably Preferably, it is 30,000 to 140,000, more preferably 40,000 to 130, The number is 000. By setting the content within the above range, it is possible to obtain a pressure-sensitive adhesive that has excellent adhesion to the substrate and shear strength. Cut. If the weight average molecular weight is too small, the adhesive will not have sufficient cohesive strength and will not be able to withstand shear stress. In addition, if the weight average molecular weight is too large, the adhesion to the substrate tends to decrease. There is a tendency to go down.

[0046] The weight average molecular weight of the polyester resin is calculated based on the molecular weight of standard polystyrene. The average molecular weight was measured by high performance liquid chromatography (Waters, "ACQUITY A The PC system was equipped with one ACQUITY APC XT 450 column and one ACQUITY One ACQUITY APC XT 200 and two ACQUITY APC XT 45. Measurements are made using a total of four in series.

[0047] The number average molecular weight of the polyester resin (A) is usually 5.0 in view of the cohesive strength of the adhesive. It is preferably 7,500 to 40,000, and particularly preferably is preferably 10,000 to 35,000, and more preferably 12,000 to 30,000. By setting the content within the above range, it is possible to obtain a pressure-sensitive adhesive that has excellent adhesion to the substrate and shear strength. Cut. If the number average molecular weight is too small, the adhesive will not have sufficient cohesive strength, and the shear strength will be Moreover, if the number average molecular weight is too large, the adhesion to the substrate tends to decrease. There is a tendency for this to happen. The number average molecular weight is determined based on the polyester resin (A) described above. It can be measured by the same method as for the weight average molecular weight of the resin.

[0048] The hydroxyl value of the polyester resin (A) is 0.1 to 50 mgKOH / g. It is preferable that the concentration is 1 to 30 mgKOH / g, more preferably 2 to 20 mgKOH / g. The hydroxyl value is preferably 3 to 15 mgKOH / g, and particularly preferably 3 to 15 mgKOH / g. However, the crosslinking efficiency with the crosslinking agent (D) tends to decrease.

[0049] The acid value of the polyester resin (A) is preferably 10 mgKOH / g or less. Preferably, the KOH content is less than 5 mgKOH / g, more preferably less than 3 mgKOH / g, and particularly preferably less than 5 mgKOH / g. Preferably it is 1 mgKOH / g or less, particularly preferably 0.5 mgKOH / g or less, most preferably Preferably, it is 0.3 mgKOH / g or less. By setting it in the above range, the polyester resin It suppresses the hydrolysis of the resin (A) and has excellent shear strength. Furthermore, it is corrosion-resistant when attached to metal. It can suppress eating. If the acid value is too high, hydrolysis tends to proceed more easily, and metal may be attached to one side of the adhesive layer. When layers such as these are bonded together, they tend to corrode.

[0050] Here, the hydroxyl value and acid value in the present invention are determined based on the neutralization droplets in accordance with JIS K 0070. This is required by law.

[0051] <Polyester-based plasticizer (B)> The polyester plasticizer (B) exhibits an effect as a plasticizer, and is a polyvalent carbon. Structural units derived from carboxylic acids (b1), structural units derived from polyols (b2), and reactivity It has a structural unit derived from the molecular end-capping agent (b3). For example, at least one of polyester resins One reactive molecular end is blocked with a reactive molecular end blocking agent (b3). be. In addition, the structural units derived from the polycarboxylic acids (b1) and the structural units derived from the polyols (b2) At least one of the structural unit and the reactive molecular end-capping agent (b3) contains an aromatic structural unit. It is preferable that the polycarboxylic acid ( b1) derived structural units and / or reactive molecular end-capping agents (b3) containing aromatic structural units It is more preferable that the reactive molecular end-capping agent (b3) contains an aromatic structural unit. It is particularly preferred that

[0052] The polyester plasticizer (B) has a polycarboxylic acid (b1) as a reactive molecular terminal. ) and a small number of carboxyl group terminals derived from polyol (b2) and hydroxyl group terminals derived from polyol (b3). The reactive molecular end of the polyester plasticizer having at least one reactive molecular end is capped with the reactive molecular end described below. It can be obtained by blocking with a blocking agent (b3). Hereinafter, the polyester plasticizer (B') before the reactive molecular ends are referred to as "end-capping" (hereinafter referred to as "end-capping"). The following will explain about the pre-chain polyester plasticizer (B').

[0053] [Polyester-based plasticizer (B') before end-capping] The polyester plasticizer (B') before end-capping is usually a polyvalent carbo The copolymerization component containing the carboxylic acid (b1) and the polyol (b2) is obtained by copolymerizing the copolymerization component. The polyester plasticizer (B') before end-capping contains, as a resin composition, a polyvalent carboxylic acid. The compound has structural units derived from the acid (b1) and structural units derived from the polyol (b2). do.

[0054] [Structural units derived from polycarboxylic acids (b1)] The structural unit derived from the polycarboxylic acid (b1) includes the structural unit derived from the polycarboxylic acid (a1) ) structural units derived from the same as those described above.

[0055] Among the structural units derived from the polycarboxylic acids (b1), the crystalline structure of polyester resins is In terms of reducing the adhesion and improving the staining resistance of the substrate, a structural unit derived from an aromatic polycarboxylic acid, In particular, it is preferred that the compound contains a structural unit derived from an asymmetric aromatic dicarboxylic acid (b1-1). Examples of structural units derived from unsymmetrical aromatic dicarboxylic acids (b1-1) include: Taric acids, isophthalic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids Examples include structural units derived from carboxylic acids and 2,7-naphthalenedicarboxylic acids. However, in terms of reactivity, structural units derived from isophthalic acids are particularly preferred.

[0056] Such structural units derived from aromatic polycarboxylic acids, particularly asymmetric aromatic dicarboxylic acids The content of structural units derived from (b1-1) is the total content of structural units derived from polycarboxylic acids (b1). It is preferably 0.1 to 100 mol %, more preferably 1 to 80 mol % , more preferably 3 to 70 mol %, particularly preferably 5 to 60 mol %, and even more preferably If the content is too low, the cohesive force may decrease and the polyester may become brittle. The terephthalate plasticizer (B) tends to crystallize, resulting in insufficient adhesive performance. If the amount is too large, the initial adhesive strength tends to decrease.

[0057] In addition, as a structural unit derived from the polycarboxylic acid (b1), From this viewpoint, aliphatic dicarboxylic acids (b1- It is preferable that the structural unit derived from 2) is contained, and in particular, it is preferable that the number of carbon atoms (carbon atoms of the carboxyl group) is large. It is more preferable that the copolymer contains 6 to 12 structural units derived from aliphatic dicarboxylic acids (including 6 to 12 structural units), It is particularly preferred that the copolymer contains structural units derived from adipic acids, sebacic acids, or azelaic acids. It's nice.

[0058] The content of structural units derived from such aliphatic dicarboxylic acids (b1-2) having 4 or more carbon atoms is In this case, the content of the structural units derived from the polycarboxylic acids (b1) is 10 to 100 mol % based on the total structural units derived from the polycarboxylic acids (b1). It is particularly preferable that the content is 20 to 95 mol %, and more preferably The content is preferably 30 to 90 mol %, more preferably 40 to 80 mol %. If the temperature is too high, the glass transition temperature of the polyester plasticizer (B) becomes too high, and sufficient adhesive strength cannot be obtained. When the content is within the preferred range, the polyester-based Crystallization of the plasticizer (B) is suppressed, and the initial adhesive strength of the adhesive tends to be excellent.

[0059] In the present invention, from the viewpoint of adhesive properties, the structural unit derived from the polycarboxylic acid (b1) is and structural units derived from asymmetric aromatic dicarboxylic acids (b1-1) and those having 4 or more carbon atoms. It is also preferable that the copolymer contains structural units derived from aliphatic dicarboxylic acids (b1-2). , a structural unit derived from an asymmetric aromatic dicarboxylic acid (b1-1) and an aliphatic dicarboxylic acid having 4 or more carbon atoms The content ratio (molar ratio) of the structural unit derived from carboxylic acids (b1-2) is (b1-1) / ( b1-2) is preferably 1 / 99 to 99 / 1, and particularly preferably 5 / 95 to 90 / 10, more preferably 20 / 80 to 80 / 20, and particularly preferably 30 / 70 to 70 / It's 30. By adjusting the range above, the compatibility with the polyester resin (A) is excellent, and the initial adhesive strength and A pressure-sensitive adhesive having excellent shear strength can be obtained.

[0060] In addition, in order to increase the branching points in polyester resins, trivalent or higher polycarboxylic acids ( It is also possible to use structural units derived from b1-3), among which gelation occurs relatively frequently during production. It is preferable to use trimellitic acids because they are less likely to cause oxidation.

[0061] The content of the structural units derived from the trivalent or higher polyvalent carboxylic acids (b1-3) is It is advantageous over all polycarboxylic acids (b1) in that it can increase the cohesive strength when used as an adhesive. Preferably, it is 10 mol % or less, particularly preferably 5 mol % or less, and particularly preferably 3 mol % or less, and most preferably 1 mol % or less. If the content is too high, the polyester During the production of the terephthalate resin, gelation tends to occur and the acid value tends to increase.

[0062] [Polyol (b2)] The structural unit derived from the polyol (b2) may be a structural unit derived from the polyol (a2). The units may be the same as those explained above.

[0063] The structural unit derived from the polyol (b2) is the glass of the polyester plasticizer (B). A linear aliphatic diol is used to lower the transition temperature (TgB) and improve initial adhesive strength. It may contain a structural unit derived from the group (b2-1), and more preferably, a straight chain having 2 to 18 carbon atoms. It contains structural units derived from an aliphatic diol having a chain structure, and particularly preferably ethylene Glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol It contains structural units derived from 1,6-hexanediol.

[0064] The content of structural units derived from linear aliphatic diol (b2-1) is ) is preferably 1 to 80 mol % based on the total structural units derived from 3 to 60 mol %, more preferably 5 to 40 mol %, particularly preferably 10 to 30 mol % If the content is too high, the polyester resin will crystallize, making it difficult to obtain sufficient adhesive properties. There is a tendency for this to become difficult.

[0065] In addition, among the structural units derived from the polyol (b2), the polyol (b3) has the advantage of being able to break down crystallinity. Therefore, it is found that the compound contains a structural unit derived from a diol (b2-2) having a hydrocarbon group in the side chain. The structural unit derived from the diol (b2-2) having a hydrocarbon group is preferably Examples of the diols having hydrocarbon groups (a2-2) include those described above. The inclusion of structural units derived from aliphatic diols with the structure suppresses crystallization and improves initial adhesion. 2-methyl-1,3-propanediol and 2,2-dimethyl- 1,3-Propanediol (Neopentyl Glycol), 3-Methyl-1,5-pentane It is particularly preferred that the copolymer contains structural units derived from a diol.

[0066] The content of the structural unit derived from the diol (b2-2) having a hydrocarbon group in the side chain is It is preferably 5 to 100 mol % based on the total structural units derived from the ol (b2), and particularly Preferably, the amount is 15 to 100 mol %, more preferably 30 to 100 mol %, particularly preferably 45 to 100 mol %, and most preferably 50 to 100 mol %. It is more preferable that the content is 60 to 100 mol %. However, the polyester plasticizer (B) tends to crystallize, resulting in a decrease in the initial adhesive strength of the adhesive.

[0067] Furthermore, as a structural unit derived from the polyol (b2), a trivalent or higher polyol (b2- The structural unit derived from such a trivalent or higher polyol (b2-3) may also be contained. The content of the structural units derived from polyol (b2) is 10 % by mole or less, more preferably 0.01 to 5 mol %, and particularly preferably 0.0 The content is preferably 5 to 3 mol %, and particularly preferably 0.1 to 1 mol %. If the content of the polyol-derived (b2-3) structural unit is too high, the initial adhesive strength will decrease. There is a tendency.

[0068] The polycarboxylic acid (b1) and the polyol (b2) are mixed to form the polyester resin. By reacting in a manner similar to the manufacturing method, the polyester plasticizer ( B') is obtained.

[0069] The polycarboxylic acids (b1) and the polyester plasticizer (B') before end-capping The blending ratio of the polyester resin (B') having a hydroxyl group terminal is In this case, 1 to 2 equivalents of polyol (b2) are used per equivalent of polycarboxylic acid (b1). It is particularly preferred that the amount is 1.03 to 1.8 equivalents, and more preferably 1.03 to 1.8 equivalents. The blending ratio of the polyol (b2) is 1.05 to 1.7, particularly preferably 1.1 to 1.6. If the ratio is too low, the compatibility with the polyester resin (A) tends to decrease, and if it is too high, As an adhesive, the cohesive strength tends to decrease and the shear strength tends to decrease. In addition, when the polyester plasticizer (B') before end-blocking has a carboxy terminal, 1 to 2 equivalents of polycarboxylic acids (b1) are used per equivalent of polyol (b2). is preferred, particularly preferably 1.03 to 1.8 equivalents, and more preferably 1.05 to 1 0.7, and particularly preferably 1.1 to 1.6. If it is too high, the compatibility with the polyester resin (A) tends to decrease, and if it is too high, the adhesive As a result, the cohesive force decreases and the shear force tends to decrease.

[0070] The polyester plasticizer (B') obtained in this manner before end-blocking has a reactive molecular end As the carboxylic acid, a carboxyl group terminal derived from a polycarboxylic acid (b1) and a polyol (b2) and has at least one terminal hydroxyl group derived from From this point of view, it is more preferable that the polymer has a terminal hydroxyl group.

[0071] The glass transition temperature (Tg'B) of the polyester plasticizer (B') before end-capping is From the viewpoint of physical properties, the temperature is usually −80 to 30° C., preferably −75 to 20° C., and more preferably Preferably -70 to 0°C, particularly preferably -65 to -20°C, and particularly preferably -60 to -40°C is. If the glass transition temperature (TgB) is too high, flexibility is lost and the initial adhesive strength decreases. The adhesive strength is less than that of finger pressure, and workability tends to decrease. The cohesive strength and shear strength tend to decrease. The glass transition temperature of the plasticizer (B') is the same as that of the polyester resin (A) described above. It can be measured by the same method as that for the glass transition temperature of the ester resin.

[0072] The number average molecular weight of the polyester plasticizer (B') before end-capping is set to 0.1 to 0.25. In terms of strength, it is usually 200 to 12,000, preferably 300 to 10,000, particularly Preferably, it is 400 to 8,000, more preferably 600 to 6,000, and particularly preferably is 800 to 5,000, more preferably 1,000 to 4,000. If the number average molecular weight is too small, the adhesive will not have sufficient cohesive strength, and the shear force will be too large. It tends to decrease easily. Moreover, if the number average molecular weight is too large, the compatibility with the polyester resin (A) tends to decrease. The number average molecular weight is determined based on the polyester resin (A) described above. It can be measured by the same method as that for the weight average molecular weight of the steric resin.

[0073] The weight average molecular weight of the polyester plasticizer (B') before end-capping is From the viewpoint of collecting power, it is 800 to 12,000, preferably 1,000 to 10,000. Particularly preferably 1,500 to 8,000, and even more preferably 2,000 to 7,5000 It is particularly preferably 2,500 to 7,000, more preferably 3,000 to 6,500. do. If the weight average molecular weight is too small, the polyester plasticizer (B) may be used as a plasticizer. In this case, the adhesive does not have sufficient cohesive strength, and the shear strength tends to decrease. In addition, if the weight average molecular weight is too large, the compatibility with the polyester resin (A) tends to decrease. The weight average molecular weight is determined based on the weight average molecular weight of the polyester resin (A) described above. It can be measured by the same method as that for the weight average molecular weight of the steric resin.

[0074] The hydroxyl value of the polyester plasticizer (B') before end-blocking is In the case of the polyester-based plasticizer (B') before blocking, the KOH content is 5 to 200 mg KOH / g. Preferably 10 to 150 mgKOH / g or less, more preferably 15 to 100 mgKOH / g If the hydroxyl value is too high, the cohesive strength tends to decrease, and if it is too low, the polyester tends to In this case, the compatibility with the vinyl resin (A) tends to decrease. In addition, when the polyester plasticizer (B') before end-blocking has a carboxyl group terminal, is 10 mgKOH / g or less, preferably 5 mgKOH / g or less, more preferably is 3 mg KOH / g or less, particularly preferably 1 mg KOH / g or less, especially preferably 0.5 mg KOH / g or less. The lower limit is 0.0 mgKOH / g. If the hydroxyl value is too high, The adhesive strength tends to decrease.

[0075] The acid value of the polyester plasticizer (B') before end-capping is determined by the acid value of the end-capping polyester plasticizer (B') having a hydroxyl group terminal. In the case of using the polyester plasticizer (B'), the plasticizer has a viscosity of 10 mgKOH / g or less, and is preferably Preferably, the concentration is 5 mgKOH / g or less, more preferably 3 mgKOH / g or less, and particularly preferably 1 mgKOH / g or less. mgKOH / g or less, especially 0.5 mgKOH / g or less. The lower limit is 0.0 mg If the acid value is too high, the cohesive strength will decrease and hydrolysis will tend to progress. do. In addition, when the polyester plasticizer (B') before end-blocking has a carboxyl group terminal, is 5 to 200 mgKOH / g, preferably 10 to 150 mgKOH / g, and more preferably The acid value is preferably 15 to 100 mgKOH / g. If the acid value is too high, the cohesive force may decrease and the temperature may become too high. There is a tendency for hydrolysis to occur more easily, and when a metal layer is attached to one side of the adhesive layer, This tends to cause corrosion in some cases.

[0076] As described above, the polyester plasticizer (B') before end-capping has the following reactive molecular terminals: The polymer generally has at least one of a carboxyl terminal group and a hydroxyl terminal group. The polyester plasticizer (B) used in the present invention is the above-mentioned pre-endblocked polyester plasticizer (B' At least one of the reactive molecular ends of the polymer (b1) is blocked by a reactive molecular end blocking agent (b3). This is obtained by:

[0077] [Structural unit derived from reactive molecular end-capping agent (b3)] The reactive molecular end-capping agent (b3) is a polyester plasticizer (B') before end-capping. The terminal reactive group (e.g., hydroxyl group) of the The reactive end of the polyester plasticizer (B') before end-capping and the functionality of the reactive end-capping agent (b3) The groups react to cap the terminal reactive groups. For example, isocyanate group-containing compounds, carbodiimide group-containing compounds, epoxy group-containing compounds Compound, oxazoline group-containing compound, carboxyl group-containing compound, hydroxy group-containing compound These may be used alone or in combination of two or more.

[0078] In the present invention, the isocyanate group-containing compound is a compound having an isocyanate group in a molecule. Monoisocyanates having one in the structure are preferred. Examples of the monoisocyanate compound include methyl isocyanate and ethyl isocyanate. cyanate, propyl isocyanate, n-butyl isocyanate, t-butyl isocyanate nate, isobutyl isocyanate, pentyl isocyanate, neopentyl isocyanate 2-Ethyl-hexyl isocyanate, 2-Isocyanatoethyl methacrylate, Aliphatic monoisocyanates such as 2-isocyanatoethyl acrylate and octadecyl isocyanate Isocyanate compounds, phenyl isocyanate, tolyl isocyanate, 1-naphthyl isocyanate Anate, 2-naphthyl isocyanate, m-isopropenyl-α,α-dimethylbenzene Examples of the aromatic monoisocyanate compounds include aromatic monoisocyanate compounds such as methylisocyanate and methylisocyanate. These may be used alone or in combination of two or more. Aromatic monoisocyanate compounds are preferred because of their excellent shear strength, and phenyl isocyanate is particularly preferred.

[0079] In the present invention, the carbodiimide group-containing compound is a compound having a carbodiimide group (-N Monocarbodiimides having one =C=N-) in the molecule are preferred. Examples of the monocarbodiimide compound include dicyclohexylcarbodiimide, Diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide , dioctylcarbodiimide, diphenylcarbodiimide, and naphthylcarbodiimide These may be used alone or in combination of two or more.

[0080] In the present invention, the epoxy group-containing compound has one epoxy group in the molecular structure. Monofunctional epoxy compounds having the above structure are preferred, and examples thereof include monoglycidyl ester compounds and mono Glycidyl ether compounds, etc. These may be used alone or in combination of two or more. It is possible.

[0081] Examples of the monoglycidyl ester compound include benzoic acid glycidyl ester, t-Bu-benzoic acid glycidyl ester, p-toluic acid glycidyl ester, cyclohexane Xanthan Glycidyl Ester, Pelargonic Acid Glycidyl Ester, Stearic Acid Glycyl ester, lauric acid glycidyl ester, palmitic acid glycidyl ester, Behenic acid glycidyl ester, versatic acid glycidyl ester, oleic acid glycidyl ester Glycidyl ester of linoleic acid, glycidyl ester of linolenic acid, beheno glycidyl ester of ... These can be used alone or in combination of two or more.

[0082] Examples of the monoglycidyl ether compounds include phenyl glycidyl ether, o-phenylglycidyl ether, etc., which may be used alone or in combination of two or more kinds. It can be used.

[0083] In the present invention, the oxazoline group-containing compound is a compound having an oxazoline group in a molecular structure A monofunctional oxazoline compound having one of the groups is preferred. 2-ethyl-2-oxazoline, etc., and these can be used alone. Alternatively, two or more types can be used in combination.

[0084] In the present invention, the carboxy group-containing compound is a compound having a carboxy group in its molecular structure. Monocarboxylic acids having one of these groups are preferred, and saturated monocarboxylic acids are particularly preferred. . Examples of the monocarboxylic acid include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, Valeric acid, isovaleric acid, 2-methylbutanoic acid, pivalic acid, hexanoic acid, 4-methylpentane Acid, 2-ethylbutanoic acid, 2,2-dimethylbutanoic acid, heptanoic acid, octanoic acid, nonane Acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadeca carboxylic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, eicosanoic acid, docosanoic acid, Aliphatic monocarboxylic acids such as hexacosanoic acid and triacontanoic acid, benzoic acid, toluic acid Aromatic monocarboxylic acids such as naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid Carboxylic acids can be used alone or in combination of two or more. However, aromatic monocarboxylic acids are preferred because of their excellent reactivity and shear strength.

[0085] In the present invention, the hydroxy group-containing compound is a compound having a hydroxy group in the molecular structure. Monoalcohols having one are preferred. Examples of the monoalcohol include butanol, hexanol, pentanol, and hexane. butanol, octanol, nonanol, decanol, undecanol, dodecanol, Aliphatic monoalcohols such as tridecanol, benzyl alcohol, 3-phenyl-1- These may be used alone or in combination of two or more. They can be used in combination.

[0086] In the present invention, the reactive molecular end-capping agent (b3) is a compound having one of the above functional groups. In addition to the compound having the above functional groups, a compound having two or more functional groups may be used within a range that does not impair the effects of the present invention. It can also be used in

[0087] Among the reactive molecular end-capping agents (b3), the polyester plasticizer before end-capping (B An isocyanate group-containing compound is preferred because it has excellent reactivity with the hydroxyl group terminal of .

[0088] In addition, the reactive molecular end-capping agent (b3) has a number average molecular weight of 100 or less, from the viewpoint of excellent adhesive properties. is preferably 50 to 5,000, more preferably 60 to 3,000. It is particularly preferable that the molecular weight is 70 to 1,000, and further preferably 80 to 500. It is particularly preferable that the molecular weight is 90 to 300. If the molecular weight is too small, the volatility is high. If the molecular weight is too large, the compatibility with the polyester resin (A) tends to decrease. do.

[0089] The polyester plasticizer (B) used in the present invention has excellent adhesive properties and is therefore At least one reactive molecular end is blocked by the molecular end blocking agent (b3). It is preferable, and more preferable, that all reactive molecular ends are blocked.

[0090] Polyester plasticizer (B') before end-capping with the reactive molecular end-capping agent (b3) The terminal blocking of the reactive molecule may be carried out by a known method, for example, by terminal blocking in an organic solvent. The polyester plasticizer (B') can be reacted with the reactive molecule end-capping agent (b3) to form a good.

[0091] The reaction of the polyester plasticizer (B') before end-capping with the reactive molecular end-capping agent (b3) The reaction ratio is determined according to the hydroxyl value and acid value of the polyester plasticizer (B') before end-capping. That is, the carboxyl group and hydroxyl group of the polyester plasticizer (B') before end-capping It is preferable to optimize the amount of the polyester plasticizer (B') before end-capping. 100 mol% of the carboxyl groups or 100 mol% of the hydroxyl groups are end-capping with reactive molecules. The functional group reactive with the reactive molecular end of the chain-linking agent (b3) is usually 80 to 120 mol %, preferably Preferably, it is 90 to 110 mol %, more preferably 95 to 105 mol %, and particularly preferably 97 % by mole, more preferably 98 to 102 mol %, and particularly preferably 99 to 101 mol %. For example, a reactive molecular end-blocking agent (b3) containing an isocyanate group may be used. When using an isocyanate-containing compound, the compound containing an isocyanate group reacts with the carboxyl group and the hydroxyl group. Therefore, the carboxyl group of the polyester plasticizer (B') before end-capping is and hydroxy groups in a total of 100 mol %. A mixture can be used.

[0092] The organic solvent used is one that does not show reactivity with the reactive molecular end-capping agent (b3). Examples of suitable esters include ethyl acetate, butyl acetate, and the like, methyl ethyl ketone, methyl Organic solvents such as ketones such as triisobutyl ketone, aromatics such as toluene and xylene are used. These can be used alone or in combination of two or more.

[0093] The reaction of the polyester plasticizer (B') before end-capping with the reactive molecular end-capping agent (b3) The reaction temperature is usually 20 to 240°C, preferably 25 to 180°C, more preferably 30 to 1 The reaction temperature is usually 20°C, particularly preferably 40 to 80°C. The reaction time is usually 0.1 to 24 hours, preferably The time is preferably 0.5 to 12 hours, and more preferably 0.5 to 3 hours.

[0094] By the above method, a polyester plastic having at least one reactive molecular end blocked can be obtained. Agent (B) can be obtained.

[0095] The glass transition temperature (TgB) of the polyester plasticizer (B) is −80 to 30° C. Preferably, the temperature is between -70 and 25°C, more preferably between -60 and 20°C. It is more preferable that the temperature is from -55 to 0°C, and particularly preferably from -50 to -10°C. It is particularly preferable that the temperature is in the range of -40 to -15°C, and most preferable that the temperature is in the range of -40 to -15°C. This allows for the production of a pressure-sensitive adhesive with excellent initial adhesive strength and shear strength. If the glass transition temperature of (B) is too low, the cohesive strength tends to decrease and the adhesive strength tends to decrease. If the glass transition temperature is too high, flexibility will be lost, the initial adhesive strength will decrease, and the adhesive will not become sticky even with pressure equivalent to finger pressure. As mentioned above, polyester tends to be less likely to adhere well. In relation to the glass transition temperature of the resin (A), the glass transition temperature of the polyester resin (A) The glass transition temperature (TgA) of the polyester plasticizer (B) is higher than the glass transition temperature (TgB) of the polyester plasticizer (B). It is preferable that the temperature is low.

[0096] The polyester plasticizer (B) is preferably amorphous. The heat of fusion of crystals is preferably 20 J / g or less, and more preferably 10 J / g or less. It is preferable that the ion exchange rate is 5 J / g or less, particularly preferable that the ion exchange rate is 5 J / g or less, and further preferable that the ion exchange rate is 3 J / g or less. If the heat of fusion of crystals is too high, the storage stability may be deteriorated. In such a case, the initial adhesive strength tends to decrease, and the compatibility with the polyester resin (A) tends to be poor.

[0097] Here, the heat of crystalline fusion of the polyester plasticizer (B) is measured by the TA Instruments This is a value measured using a differential scanning calorimeter DSC Q20. The measurement temperature range was -90 to 100°C, and the temperature rise rate was 10°C / min. After heating to 0°C and completely melting, the temperature was lowered to -90°C and then raised again to 100°C. The heat of fusion in this case was taken as the heat of fusion of crystals.

[0098] The number average molecular weight of the polyester plasticizer (B) is 3.0 or less from the viewpoint of the cohesive strength of the adhesive. It is preferably 400 to 10,000, and particularly preferably 6 00 to 8,000, more preferably 1,000 to 6,000, and particularly preferably 1,20 It is 0 to 5,000, more preferably 1,500 to 4,000. With this, it is possible to obtain a pressure-sensitive adhesive having excellent initial adhesive strength and shear strength. If it is too low, the polyester plasticizer (B) may not be sufficiently effective as an adhesive. Cohesive strength is not obtained, and the initial adhesive strength tends to decrease. If the number average molecular weight is too high, the compatibility with the polyester resin (A) tends to decrease. The molecular weight is the weight average molecular weight of the polyester resin described above in connection with the polyester resin (A). It can be measured by the same method as

[0099] The weight average molecular weight of the polyester plasticizer (B) is 1.0 to 1.5 times the cohesive strength of the adhesive. It is preferably 1,200 to 10,000, and particularly preferably Preferably 1,500 to 8,000, more preferably 2,000 to 7,500, particularly preferably The range is preferably 2,500 to 7,000, and more preferably 3,000 to 6,500. By setting the weight within this range, it is possible to obtain a pressure-sensitive adhesive having excellent initial adhesive strength and shear strength. If the average molecular weight is too small, adhesion may occur when a polyester plasticizer (B) is used as a plasticizer. As a result, the cohesive strength of the agent is not sufficient, and the shear strength tends to decrease. If the molecular weight is too large, the compatibility with the polyester resin (A) tends to decrease. The weight average molecular weight is the same as that of the polyester resin (A) described above. The weight average molecular weight of the polymer can be measured by the same method as that of the polymer.

[0100] The hydroxyl value of the polyester resin (B) is preferably 15 mgKOH / g or less. It is preferable that the content is 10 mgKOH / g or less, and more preferable that the content is 8 mgKOH / g or less. It is more preferable that the concentration is 5 mgKOH / g or less, and particularly preferable that the concentration is 3 mgKOH / g or less. / g or less is particularly preferred, and 1 mgKOH / g or less is most preferred. The lower limit is 0 mgKOH / g. If the hydroxyl value is too high, the polyester resin (A ) and tends to crosslink, reducing initial adhesive strength.

[0101] The acid value of the polyester resin (B) is preferably 10 mgKOH / g or less. , and more preferably 5 mgKOH / g or less, and more preferably 3 mgKOH / g or less. It is more preferable that the KOH content is 1 mgKOH / g or less, and particularly preferable that the KOH content is 0.5 mgKOH / g or less. It is particularly preferable that the KOH / g or less. The lower limit is 0 mgKOH / g. By setting the range, the hydrolysis of the polyester resin (A) is suppressed and the initial adhesive strength is improved. If the acid value is too high, the polyester resin (A) may not be crosslinked. However, the initial adhesive strength and hydrolysis resistance tend to decrease.

[0102] The total acid value and hydroxyl value of the polyester plasticizer (B) is 20 mg KOH / g or less. It is preferable that the KOH content is 15 mgKOH / g or less, and more preferable that the KOH content is 10 mgKOH / g or less. It is more preferable that the concentration is 5 mgKOH / g or less, and particularly preferable that the concentration is 5 mgKOH / g or less. It is particularly preferable that the KOH content is 3 mg KOH / g or less, and 1 mg KOH / g or less. The lower limit is 0 mgKOH / g. If the total of the acid value and the hydroxyl value is too high, If this occurs, crosslinking with the polyester (A) occurs, resulting in a decrease in initial adhesive strength and a decrease in hydrolysis resistance. There is a tendency for this to happen.

[0103] The content of the polyester plasticizer (B) is 100 parts by weight of the polyester resin (A). It is preferably 0.1 to 180 parts by weight, more preferably 1 to 175 parts by weight, based on the total weight of the It is more preferable that the amount is 5 to 170 parts by weight, and even more preferable that the amount is 10 to 160 parts by weight. It is particularly preferable that the amount is 30 to 150 parts by weight, more preferably 40 to 140 parts by weight. It is more preferable that the amount is 50 to 130 parts by weight, and particularly preferable that the amount is 60 to 130 parts by weight. It is particularly preferably 120 parts by weight, and most preferably 70 to 110 parts by weight. By setting the content within the above range, it is possible to obtain a pressure-sensitive adhesive having excellent adhesive strength, initial adhesive strength, and shear strength. If the content of polyester plasticizer (B) is too high, the cohesive force decreases and the shear force If the content is too low, the adhesive strength and initial adhesive strength tend to decrease.

[0104] The content of the polyester plasticizer (B) is 10% by weight of the pressure-sensitive adhesive composition (active ingredient amount). Preferably, the content is 0.1 to 75% by weight, and more preferably 1 to 70% by weight, relative to 0% by weight. is more preferable, and 5 to 65% by weight is even more preferable, and 10 to 60% by weight is still more preferable. It is particularly preferable that the content is 20 to 55% by weight, and particularly preferable that the content is 30 to 50% by weight. If the content of the polyester plasticizer (B) is too high, the cohesive force may be reduced. If the content is too low, the adhesive strength and initial adhesive strength will decrease. There is a tendency to

[0105] <Hydrolysis inhibitor (C)> The pressure-sensitive adhesive composition of the present invention preferably further contains a hydrolysis inhibitor (C). The hydrolysis inhibitor (C) is contained to ensure long-term durability.

[0106] As the hydrolysis inhibitor (C), a conventionally known one can be used, for example, Examples of the compound include a compound that reacts with the carboxyl terminal of the polyester resin (A) to bond. Specifically, functional groups such as a carbodiimide group, an epoxy group, an oxazoline group, etc. The hydrolysis inhibitor (C) may be used alone or in combination of two or more. Among them, the carbodiimide group-containing compound is preferably a compound having a carboxylic acid terminal. This is preferred in that it is highly effective in eliminating the catalytic activity of the protons derived from the group.

[0107] The carbodiimide group-containing compound is generally a compound having a carbodiimide group (-N=C=N- ) in the molecule, and among them, carbodiimide compounds A compound containing two or more diimide groups in the molecule, i.e., a polyvalent carbodiimide compound. It is particularly preferable that the number of carbodiimide groups in the molecule is 3 or more, and more preferably 5 or more. In particular, compounds containing 7 or more of these groups are preferred. The compound usually contains 50 or less carbodiimide groups in the molecule. If there are too many amido groups, the molecular structure becomes too large, so This tends to decrease compatibility, which is undesirable.

[0108] The carbodiimide group-containing compound may be a compound selected from the group consisting of diimide compounds, diisopropyl ether compounds, and diisopropyl ether compounds. High molecular weight polycarbodiimides produced by decarboxylation condensation of isocyanates It is also preferable to use a

[0109] Such high molecular weight polycarbodiimides may be synthesized or commercially available products may be used. When synthesizing a high molecular weight polycarbodiimide, for example, the following diisocyanate is derivatized: Examples include those obtained by carbonic acid condensation reaction.

[0110] Such diisocyanates include, for example, 4,4'-diphenylmethane diisocyanate. ester, 3,3'-dimethoxy-4,4'-diphenylmethane diisocyanate, 3,3' -Dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-diphenylamine Diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1- Methoxyphenyl-2,4-diisocyanate, isophorone diisocyanate, 4,4' -Dicyclohexylmethane diisocyanate, tetramethylxylylene diisocyanate These can be used alone or in combination of two or more.

[0111] Furthermore, the terminal isocyanate groups of the high molecular weight polycarbodiimide are sealed with a sealing agent. The sealing agent is preferably a compound having an isocyanate group and a carboxylic acid group. Compounds with reactive active hydrogen or compounds with isocyanate groups are examples. For example, a compound having one substituent selected from a carboxy group, an amino group, and an isocyanate group Monoalcohols, monocarboxylic acids, monoamines, and monoisocyanates Examples include:

[0112] The carbodiimide equivalent of the carbodiimide group-containing compound is preferably 50 to 100 00, particularly 100 to 1000, and further preferably 150 to 500. The carbodiimide equivalent weight refers to the chemical formula weight per carbodiimide group.

[0113] The carbodiimide group-containing compound may be a commercially available product. Commercially available products of the compound include, for example, Carbodilite (registered trademark) manufactured by Nisshinbo Chemical Co., Ltd. ) series, among which Carbodilite (registered trademark) "V-01", "V-02B", "V-03", "V-04K", "V-04PF", "V-05", " V-07, V-09, and V-09GB are compatible with polyester resin (A). It is preferable in terms of its superiority.

[0114] Examples of the epoxy group-containing compound include glycidyl ester compounds and glycidyl These may be used alone or in combination of two or more. do. Examples of the glycidyl ester compound include benzoic acid glycidyl ester, t- Bu-benzoic acid glycidyl ester, p-toluic acid glycidyl ester, cyclohexa Glycidyl ester of carboxylic acid, glycidyl ester of pelargonic acid, glycidyl ester of stearate Glycidyl ester, lauric acid glycidyl ester, palmitic acid glycidyl ester, behen Glycidyl ester of carboxylic acid, glycidyl ester of versatic acid, glycidyl oleate Esters, glycidyl linoleate, glycidyl linoleate, behenol Acid glycidyl ester, stearolic acid glycidyl ester, diglycidyl terephthalate Ester, isophthalic acid diglycidyl ester, phthalic acid diglycidyl ester, naphtha Diglycidyl ester of diphenyl ether, diglycidyl ester of methyl terephthalic acid, Hexahydrophthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester , cyclohexanedicarboxylic acid diglycidyl ester, adipic acid diglycidyl ester , succinic acid diglycidyl ester, sebacic acid diglycidyl ester, dodecanedioic acid Diglycidyl ester, Octadecanedicarboxylic acid diglycidyl ester, Trimelli acid triglycidyl ester, pyromellitic acid tetraglycidyl ester, etc. These can be used alone or in combination of two or more.

[0115] Examples of the glycidyl ether compound include phenyl glycidyl ether, o- Phenyl glycidyl ether, 1,4-bis(β,γ-epoxypropoxy)butane, 1 ,6-bis(β,γ-epoxypropoxy)hexane, 1,4-bis(β,γ-epoxy 1-(β,γ-epoxypropoxy)benzene, 1-(β,γ-epoxypropoxy)-2-ethoxyethane, 1- (β,γ-epoxypropoxy)-2-benzyloxyethane, 2,2-bis-[р-( β,γ-epoxypropoxy)phenyl]propane, and 2,2-bis-(4-hydroxyphenyl)propane Bisphenols such as 2,2-bis-(4-hydroxyphenyl)propane and 2,2-bis-(4-hydroxyphenyl)methane Examples include bisglycidyl polyether obtained by the reaction of phenol with epichlorohydrin. These may be used alone or in combination of two or more.

[0116] 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) 2,2'-diphenylenebis(2-oxazoline), 2,2'-diphenylenebis(2-oxazoline), etc. These can be used alone or in combination of two or more.

[0117] It is preferable that the hydrolysis inhibitor (C) has low volatility. It is preferable to use a polymer having a high molecular weight, usually 300 to 10,000, preferably 1 Use one that is between 1,000 and 5,000. In addition, as the hydrolysis inhibitor (C), a compound having a high weight average molecular weight is preferred from the viewpoint of hydrolysis resistance. The weight average molecular weight of the hydrolysis inhibitor (C) is preferably 500 to 30 ,000, and more preferably 2,000 to 20,000 or more. It is more preferable that the molecular weight is 3,000 to 15,000 or more, and more preferably 4,000 to 10,000. 00 is especially preferred. If the molecular weight of the hydrolysis inhibitor (C) is too small, the hydrolysis resistance tends to decrease. If the molecular weight is too large, the compatibility with the polyester resin (A) tends to decrease. do.

[0118] The content of the hydrolysis inhibitor (C) is 100 parts by weight of the polyester resin (A). It is preferably 0.01 to 10 parts by weight, and particularly preferably 0.1 to 5 parts by weight. The amount is more preferably 0.3 to 3 parts by weight, and particularly preferably 0.5 to 2 parts by weight. If the content is too high, the initial adhesive strength with the polyester resin (A) may decrease, or compatibility may become insufficient. If the amount is too small, it tends to be difficult to obtain sufficient durability. do.

[0119] The content of the hydrolysis inhibitor (C) is determined based on the acid value of the polyester resin (A). It is preferable to optimize the content accordingly. For example, when the polyester resin (A) is a polyester resin, The ratio of the total mole number (X) of the acidic functional groups of the polyester resin to the total mole number (X) of the hydrated functional groups in the pressure-sensitive adhesive composition The molar ratio ((Y) / (X)) of the total number of moles of functional groups in the decomposition inhibitor (C) is 0.5 or less. (Y) / (X) is preferably 1≦(Y) / (X)≦1000, and particularly preferably 1≦(Y) / (X)≦1000. More preferably, 1.5≦(Y) / (X)≦100. If the molar ratio of (Y) to (X) is too low, the moisture and heat resistance tends to decrease. If the molar ratio of (Y) to (X) is too high, the compatibility with the polyester resin (A) will be poor. The adhesive strength, cohesion and durability tend to decrease.

[0120] <Crosslinking agent (D)> The pressure-sensitive adhesive composition of the present invention preferably further contains a crosslinking agent (D). Examples of the crosslinking agent (D) include polyisocyanate compounds, polyepoxy compounds, and the like. At least one of the hydroxyl groups and carboxyl groups contained in the polyester resin (A) is Among these, compounds with functional groups that react with one another are those with high initial adhesive strength and mechanical strength. Polyisocyanate compounds are particularly preferred because they offer a good balance of mechanical strength and heat resistance. It is preferable that

[0121] Examples of such polyisocyanate compounds include tetramethylene diisocyanate. Hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate Diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate Xylylene diisocyanate, hydrogenated xylylene diisocyanate, tetramethyl Silylene diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane Polyisocyanates such as triisocyanate are also included. and polyol compounds such as trimethylolpropane, and Examples of the biuret and isocyanurate compounds of the anate compounds are as follows. Isocyanate compounds are compounds in which the isocyanate moiety is blocked with phenol, lactam, etc. These crosslinking agents (D) can be used alone or in combination. Alternatively, two or more types may be used in combination.

[0122] The content of the crosslinking agent (D) depends on the molecular weight of the polyester resin (A) and the intended use. Although it can be appropriately selected, it is usually the hydroxyl group and carboxyl group contained in the polyester resin (A) that are the most preferable. The reactive group contained in the crosslinking agent (D) is 0.2 times the equivalent of at least one of the hydroxy groups. The crosslinking agent (D) is preferably contained in an amount of 0.5 to 10 equivalents, and particularly preferably 0.5 to 10 equivalents. The amount is preferably from 0.5 to 5 equivalents, and more preferably from 0.5 to 3 equivalents. If the number of equivalents of the reactive groups contained in the crosslinking agent (D) is too small, the cohesive strength tends to decrease. If it is too large, flexibility tends to decrease.

[0123] The content of the crosslinking agent (D) is 100 parts by weight of the polyester resin (A). The content is preferably 0.1 to 20 parts by weight, and more preferably 0.5 to 15 parts by weight. It is particularly preferably 1 to 10 parts by weight, and even more preferably 1.5 to 8 parts by weight. It is preferable that the content of the crosslinking agent (D) is 2 to 6 parts by weight, and it is particularly preferable that the content of the crosslinking agent (D) is too high. If the content is too low, the initial adhesive strength tends to decrease, and if the content is too low, the shear strength tends to decrease.

[0124] In the reaction between the polyester resin (A) and the crosslinking agent (D), an organic solvent that does not have a functional group that reacts with the vinyl resin (A) and the crosslinking agent (D), e.g. esters such as ethyl acetate and butyl acetate, methyl ethyl ketone, methyl isobutyl ketone Examples of the organic solvent that can be used include ketones such as benzene, and aromatics such as toluene and xylene. These may be used alone or in combination of two or more.

[0125] <Urethanization catalyst (E)> The pressure-sensitive adhesive composition of the present invention preferably further contains a urethanization catalyst (E). Examples of the urethane catalyst (E) include organometallic compounds and tertiary amine compounds. These can be used alone or in combination of two or more.

[0126] Examples of the organometallic compounds include zirconium compounds, iron compounds, tin compounds, and the like. Examples of compounds include titanium compounds, lead compounds, cobalt compounds, and zinc compounds. can. Examples of zirconium compounds include zirconium naphthenate and zirconium acetate. Examples include ethyl acetonate. Examples of iron compounds include iron acetylacetonate and iron 2-ethylhexanoate. Examples include: Examples of tin compounds include dibutyltin dichloride, dibutyltin oxide, and dibutyltin. tin dilaurate and the like. Examples of titanium compounds include dibutyltitanium dichloride and tetrabutyltitanium. butoxytitanium trichloride, and the like. Examples of lead compounds include lead oleate, lead 2-ethylhexanoate, lead benzoate, Examples include lead naphthenate. Examples of cobalt compounds include cobalt 2-ethylhexanoate and cobalt benzoate. Examples include: Examples of zinc compounds include zinc naphthenate and zinc 2-ethylhexanoate. can be done.

[0127] Examples of the tertiary amine compound include triethylamine and triethylenediamine. amine, 1,8-diazabicyclo-(5,4,0)-undecene-7, and the like.

[0128] Among these urethane catalysts (E), the following are preferred in terms of reaction rate and pot life of the adhesive layer: Organometallic compounds are preferred, zirconium compounds are particularly preferred, and zirconium compounds are particularly preferred. Most commonly, zirconium acetylacetonate.

[0129] [Catalytic inhibitor] The pressure-sensitive adhesive composition of the present invention has the advantages of extending the pot life and improving the coating properties. It is preferable that the urethanization catalyst (E) contains a catalytic inhibitor. Examples of catalytic inhibitors include methyl acetoacetate, ethyl acetoacetate, and acetoacetic acid. β-ketoacetate such as octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, and stearyl acetoacetate β-esters such as acetylacetone, 2,4-hexanedione, and benzoylacetone These are keto-enol tautomeric compounds, and these are the same as those mentioned above. By protecting the urethanization catalyst (E), the catalytic activity of the urethanization catalyst (E) in solution state is improved. This reduces the viscosity of the adhesive composition, suppressing excessive viscosity increase and gelation of the adhesive composition after blending, and The pot life of the composition can be extended. Among these, from the viewpoint of the balance between pot life and curing speed, It is preferable to use acetylacetone as the catalyst inhibitor. Two or more of these can be used in combination.

[0130] The blending ratio (weight ratio) of the catalyst inhibitor and the urethane catalyst (E) is: catalyst inhibitor: urethan. The ratio of the ethane catalyst (E) is preferably in the range of 0.001:1 to 15:1, and more preferably The ratio is preferably 0.005:1 to 13:1, and particularly preferably 0.01:1 to 10:1. If the content of the catalyst inhibitor is too low compared to the content of the urethane catalyst (E), If too much is used, the curing speed tends to decrease. do.

[0131] In the pressure-sensitive adhesive composition of the present invention, the polyester resin (A) and the polyester copolymer (B) are In addition to plasticizers (B), hydrolysis inhibitors (C), crosslinking agents (D), urethane catalysts (E), etc., In the range not impairing the effects of the present invention, antioxidants such as hindered phenols, softening agents, Additives such as UV absorbers, silane coupling agents, stabilizers, antistatic agents, and tackifiers and other inorganic or organic fillers, metal powders, pigments, and other powders and particulate additives. These can be used alone or in combination of two or more.

[0132] The tackifier is not particularly limited, and conventionally known tackifiers may be used. For example, terpene-based tackifiers, phenol-based tackifiers, rosin-based tackifiers, etc. tackifier, petroleum-based tackifier, xylene-based tackifier, epoxy-based tackifier, polyamide-based tackifier Examples of suitable tackifiers include tackifiers, ketone-based tackifiers, and elastomer-based tackifiers. Uses petroleum-based tackifying resins and terpene-based tackifiers due to their excellent initial adhesive strength and adhesive strength. It is preferable to use a styrene-based tackifier or a terpene phenol-based tackifier resin. These can be used alone or in combination of two or more.

[0133] When the tackifier is blended, the amount is determined based on 100 parts by weight of the polyester resin (A). The content is preferably 0.01 to 50 parts by weight, more preferably 0.1 to 30 parts by weight, and even more preferably 0.01 to 50 parts by weight. More preferably, the amount is 1 to 20 parts by weight, and particularly preferably 3 to 10 parts by weight. This is preferable in that it has excellent properties.

[0134] In addition to the additives, the adhesive composition of the present invention also contains other components for the adhesive composition. It may contain a small amount of impurities contained in the raw materials.

[0135] Such a pressure-sensitive adhesive composition may comprise, for example, the above-mentioned polyester resin (A), polyester resin (B), Prepare the plasticizer (B) and other necessary optional components, and mix them during the production of the polyester resin (A). or by dissolving the polyester resin (A) in an organic solvent. It can be obtained by blending it in a solution and dispersing it using a mixing roller.

[0136] The pressure-sensitive adhesive of the present invention is made of the pressure-sensitive adhesive composition, i.e., The composition is crosslinked (cured).

[0137] The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive. The pressure-sensitive adhesive sheet has a pressure-sensitive adhesive layer on one or both sides of a supporting substrate. Alternatively, the double-sided PSA sheet may be a substrateless type that does not have a substrate. The pressure-sensitive adhesive sheet of the present invention is particularly suitable as an adhesive sheet for electronic components used for bonding electronic components. It is suitable as a sheet. In the present invention, the term "sheet" includes "film" and "tape." do.

[0138] <Adhesive sheet> The pressure-sensitive adhesive sheet can be produced, for example, as follows. Such a pressure-sensitive adhesive sheet can be manufactured by a method according to a known general method for manufacturing a pressure-sensitive adhesive sheet. For example, the pressure-sensitive adhesive composition can be applied to one surface of a substrate, followed by drying, A pressure-sensitive adhesive layer is formed, and a release sheet is attached to its surface (the surface opposite to the surface that contacts the substrate). By further curing, it is possible to obtain a film having a substrate and a pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer is attached to at least one side of the substrate. Thus, the pressure-sensitive adhesive sheet of the present invention is obtained.

[0139] Alternatively, the pressure-sensitive adhesive composition is applied to a release sheet and dried to form a pressure-sensitive adhesive layer; A substrate is attached to the surface (the side opposite to the release sheet) and cured as necessary. The pressure-sensitive adhesive sheet of the present invention can also be obtained.

[0140] In addition, a pressure-sensitive adhesive layer is formed on a release sheet, and its surface (the surface opposite to the surface in contact with the release sheet) By laminating the release sheet and another release sheet to the substrate, a substrate-less It is possible to produce a substrate-less double-sided PSA sheet of this type.

[0141] When using the obtained pressure-sensitive adhesive sheet or substrate-less double-sided pressure-sensitive adhesive sheet, the release sheet is adhered to the sheet. The adhesive layer is peeled off and the adhesive layer is stuck to the adherend.

[0142] Examples of the substrate include a resin film, paper, cloth, a rubber sheet, a foam sheet, and a metal. A foil, a composite of these, or the like can be used. Examples of the resin film include polyethylene (PE) and polypropylene (PP). Polyolefin films such as ethylene-propylene copolymers; polyethylene terephthalate Polyester film such as PET; vinyl chloride resin film; vinyl acetate resin Film; Polyimide resin film; Polyamide resin film; Fluorine resin film; Poly Examples of the material include polyurethane films and cellophane. Examples of the paper include Japanese paper, kraft paper, glassine paper, fine paper, synthetic paper, and topcoat. Examples include paper. Examples of the fabric include woven fabrics and nonwoven fabrics made of various fibrous materials, either alone or in combination. Examples of the fibrous material include cotton, staple fiber, Manila hemp, pulp, and rayon. , acetate fiber, polyester fiber, polyvinyl alcohol fiber, polyamide fiber, polyolefin fibers and the like. Examples of the rubber sheet include a natural rubber sheet and a butyl rubber sheet. . Examples of the foam sheet include a foam polyurethane sheet and a foam polyacrylic sheet. Examples include foamed polyolefin sheets. Examples of the metal foil include aluminum foil and copper foil. These substrates can be used as a single layer or as a multi-layer structure in which two or more types are laminated. can.

[0143] Among these, polyethylene terephthalate, polyimide, and polyurethane foam are particularly The substrate is preferably a sheet, a foamed polyacrylic sheet, or a foamed polyolefin sheet. The base is preferably polyethylene terephthalate, which is particularly preferred because of its excellent adhesiveness to adhesives. The adhesive strength between the material and the adhesive is excellent, and the adhesive effect of the present invention can be significantly exhibited. preferable.

[0144] Examples of the release sheet include the various resin films, paper, cloth, and rubber exemplified above as the substrate. It is possible to use rubber sheets, foam sheets, metal foils, and composites of these that have been treated with release agents. Among them, it is preferable to use a silicone-based release sheet as the release sheet. It's nice.

[0145] When a resin film is used as the substrate, the thickness of the resin film substrate is not particularly limited. In order to prevent the PSA sheet from becoming excessively thick, the thickness of the base film is, for example, The thickness is set to 200 μm or less, preferably 150 μm or less, and more preferably 100 μm or less. The thickness of the base film can be adjusted depending on the purpose and mode of use of the pressure-sensitive adhesive sheet. It may be 70 μm or less, 50 μm or less, 30 μm or less, or 20 μm or less. By reducing the thickness of the base film, the adhesive sheet can be Even if the total thickness of the sheet is the same, the thickness of the adhesive layer can be increased. This can be advantageous from the viewpoint of improving adhesion to the substrate. However, from the viewpoint of the handling and processability of the adhesive sheet, It is 0.5 μm or more, preferably 2 μm or more, and particularly preferably 4 μm or more.

[0146] When a foam substrate is used as the substrate, the thickness of the foam substrate is not particularly limited. It can be set appropriately depending on the strength, flexibility, and purpose of use of the sheet. From this viewpoint, the thickness of the foam substrate is usually 0.70 mm or less, and 0.40 mm or less. It is more preferable that the thickness is 0.2 mm or less, and particularly preferable that the thickness is 0.30 mm or less. From the viewpoint of impact resistance, the thickness of the foam substrate is particularly preferably 0.05 mm or more. is preferable, 0.06 mm or more is more preferable, 0.07 mm or more is particularly preferable, and 0. A thickness of 10 mm or more is particularly preferable. As the thickness of the foam substrate increases, impact resistance is exhibited. This is a trend.

[0147] The pressure-sensitive adhesive composition can be applied by, for example, a gravure roll coater or a reverse roll coater. Roll coater, kiss roll coater, dip roll coater, bar coater, knife coater A coater, spray coater, comma coater, or the like may be used.

[0148] As for the drying conditions after coating the pressure-sensitive adhesive composition, the drying temperature is preferably 60 to 140°C. The drying temperature is preferably 80 to 120° C., and more preferably 80 to 120° C. The drying time is preferably 0.5 to 30 minutes. The time is preferably 1 to 5 minutes.

[0149] The conditions for the above curing treatment are usually room temperature (23℃) to 70℃, and the time is usually 1 to 3 hours. 0 days, specifically, for example, 1 to 20 days at 23°C, preferably 3 to 14 days at 23°C. The incubation may be carried out under conditions such as 1 to 10 days at 40°C.

[0150] The thickness of the pressure-sensitive adhesive sheet and the pressure-sensitive adhesive layer of the substrate-less double-sided pressure-sensitive adhesive sheet is not particularly limited. However, in either case, the thickness is preferably 0.5 to 500 μm, and particularly preferably 1 to 300 μm. It is preferably 5 to 200 μm, and more preferably 10 to 100 μm. If the adhesive layer is too thin, the adhesive strength tends to decrease, and if it is too thick, it is difficult to apply evenly. This makes it difficult to apply the coating, and also tends to cause problems such as bubbles in the coating film.

[0151] The thickness of the adhesive layer was measured using a Digimatic Indicator (Mitutoyo Corporation, ID-C1 12B), the thickness of the components other than the adhesive layer was calculated from the measured thickness of the entire adhesive sheet. This value is obtained by subtracting the measured value.

[0152] The gel fraction of the pressure-sensitive adhesive layer is 5% by weight or more in terms of adhesive strength and initial adhesive strength. It is particularly preferable that the content is 10 to 80% by weight, and further preferably 15 to 70% by weight. The gel fraction is particularly preferably 20 to 65% by weight, and most preferably 25 to 60% by weight. If the gel fraction is too low, the shear strength tends to decrease. There is a tendency for it to decrease.

[0153] The gel fraction is a measure of the degree of crosslinking and is calculated, for example, by the following method. That is, a pressure-sensitive adhesive layer is formed on a polymer sheet (e.g., PET film) that serves as a base material. The adhesive sheet (without a separator) is wrapped in a 200 mesh SUS wire mesh. The adhesive was wrapped in a plastic bag and immersed in toluene at 23°C for 24 hours. The weight of the adhesive component before immersion was calculated based on the weight of the adhesive component after immersion. The weight percentage of the undissolved adhesive component remaining in the wire mesh after the treatment is taken as the gel fraction. The weight of the

[0154] Furthermore, such a pressure-sensitive adhesive sheet may be provided with a release sheet on the outside of the pressure-sensitive adhesive layer, if necessary, to prevent adhesion. In addition, in the case of a PSA sheet in which the PSA layer is formed on one side of the substrate, By subjecting the surface of the substrate opposite to the pressure-sensitive adhesive layer to a release treatment, the release-treated surface can be used to It is also possible to protect the adhesive layer by using the adhesive layer.

[0155] The pressure-sensitive adhesive of the present invention can be used to bond various members together, among which: It can be used as an adhesive for optical components used for bonding optical components and as an adhesive for labels. preferable.

[0156] The optical member with the pressure-sensitive adhesive layer may further include a release film on the surface of the pressure-sensitive adhesive layer opposite to the optical member surface. When the adhesive is put into practical use, the release film is peeled off and the adhesive layer is The adhesive layer is pasted onto the adherend. As the release film, a silicone-based release film is used. It is preferable to use [Example]

[0157] The present invention will be explained in more detail below with reference to examples, but the present invention will not go beyond the gist of the invention. The present invention is not limited to the following examples unless otherwise specified. Unless otherwise specified, all values ​​are by weight. In the following examples, the glass transition temperature, weight average molecular weight, number average molecular weight, acid value, The hydroxyl value and the like were measured according to the above-mentioned method.

[0158] The components were prepared as follows: The molar percentages of the polycarboxylic acids described in the following polyester resin production examples are indicates a molar ratio when the total amount of polycarboxylic acids is taken as 100 mol %. In addition, the mol % of each component, which is a polyol, described in the following production examples is the total mol % of the polyol. The molar ratio is shown when the amount is taken as 100 mol %.

[0159] [Polyester resin (A)] [Production of Polyester Resin (A-1)] A reactor equipped with a heater, a thermometer, a stirrer, a rectification column, a nitrogen inlet tube, and a vacuum device was installed. As polyvalent carboxylic acids (a1), 355 parts of isophthalic acid, 185 parts of sebacic acid, polyol As for (a2), 286 parts of neopentyl glycol, 137 parts of 1,4 butanediol, 1 ,6-hexanediol 31 parts, trimethylolpropane 5 parts, zinc acetate 0. The internal temperature was raised to 250°C, and the esterification reaction was carried out for 4 hours. After that, the internal temperature was raised to 260°C, and 0.05 parts of tetrabutyl titanate was added as a catalyst. The pressure was reduced to 1.33 hPa, and a polycondensation reaction was carried out over 3 hours to produce a polyester resin ( A-1) was obtained. The resulting polyester resin (A-1) had a glass transition temperature (Tg) of 1°C and a number average molecular weight of 1.001. The amount was 18,000 and the weight average molecular weight (Mw) was 90,000. The ratio of the finished components is as follows: polycarboxylic acids (a1) is isophthalic acid / sebacillus acid Polyol (a2) = 70 mol% / 30 mol%, neopentyl glycol / 1 ,4-butanediol / 1,6-hexanediol / trimethylolpropane = 58.5 mo The results were 34 mol % / 6.2 mol % / 1.3 mol %.

[0160] [Production of Polyester Resins (A-2) and (A'-1)] Polyethylene glycol monoacrylate was prepared in the same manner as A-1, except that the resin composition was changed as shown in Table 1. Steric resins (A-2) and (A'-1) were obtained.

[0161] The polyester resins (A-1), (A-2) and (A'-1) obtained above were The fat composition and physical properties are shown in Table 1.

[0162] [Table 1]

[0163] [Polyester-based plasticizer (B-1)] [Production of Polyester-Based Plasticizer (B'-1) Before End-Capping] A reactor equipped with a heater, a thermometer, a stirrer, a rectification column, a nitrogen inlet tube, and a vacuum device was installed. As shown in Table 2 below, polycarboxylic acids (b1) include isophthalic acid (IPA; b1 290 parts of adipic acid (AdA; b1-2), 255 parts of polyol (b2) 454 parts of 3-methylpentanediol (MPD; b2-2) as a catalyst, tetrahydrofuran as a catalyst, Add 0.05 parts of butyl titanate, raise the internal temperature to 250°C, and simmer for 4 hours. The silylating reaction was carried out. After that, the internal temperature is raised to 260°C, the pressure is reduced to 100 hPa, and the esterification reaction is carried out for 1 hour. The polyester resin (B'-1) before end-capping was obtained. The final component ratio of the polyester plasticizer (B'-1) is polycarboxylic acid (a1). isophthalic acid / adipic acid=50 / 50 mol%, polyol (a2) was 3-methyl The acid value was 0.1 mg KOH / The hydroxyl value was 56.0 mgKOH / g. The physical properties of the resulting polyester resin (B'-1) before end-capping are shown in Table 2 below. .

[0164] [Production of polyester plasticizer (B-1)] 4 parts of ethyl acetate per 100 parts of the polyester plasticizer (B'-1) before end-blocking 11.8 parts of phenyl isocyanate as a blocking agent, and the mixture was heated at an internal temperature of 60°C for 4 hours. The resulting polyester resin (B-1) had its reactive molecular ends blocked. The acid value of the polyester resin (B-4) was 0.1 mgKOH / g and the hydroxyl value was 0.6 mg The obtained polyester resin (B-1) had a heat of fusion (J / g) peak was not observed, and there was no melting point.

[0165] Various physical properties of the polyester resin (B-1) with the reactive molecular ends blocked obtained above etc. are shown in Table 3 below.

[0166] [Table 2]

[0167] [Table 3]

[0168] [Hydrolysis inhibitor (C)] (C-1): Polycarbodiimide compound (manufactured by Nisshinbo Chemical Co., Ltd., "Carbodilite V-0" 9GB"; Number average molecular weight 3,700; Weight average molecular weight 9,200; (A-1)Y / X=1 4.0;(A-2)Y / X=9.3)

[0169] [Crosslinking agent (D)] (D-1): Trimethylolpropane / tolylene diisocyanate adduct (manufactured by Tosoh Corporation, "Coronate L55E")

[0170] [Urethanization catalyst (E)] (E-1): Zirconium-based compound (pine) diluted with acetylacetone to a solid concentration of 1% Moto Fine Chemical Co., Ltd., "Orgatics ZC-150")

[0171] Example 1 The polyester resin (A-1) obtained above was diluted with ethyl acetate to a solids concentration of 50%. The polyester resin (A-1) (100 parts as solid content) is mixed with a polyester 50 parts of plasticizer (B-1), 0.5 parts (solids) of hydrolysis inhibitor (C-1), crosslinking agent (D -1) 3.5 parts (solid content), urethane catalyst (E-1) 0.02 parts (solid content), The mixture was stirred and mixed to obtain a pressure-sensitive adhesive composition.

[0172] Example 2 In Example 1, 50 parts of polyester plasticizer (B-1) and 100 parts of crosslinking agent (D- 1) A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1, except that the amount was changed from 3.5 parts to 6.5 parts.

[0173] Example 3 In Example 1, 50 parts of polyester plasticizer (B-1) and 150 parts of crosslinking agent (D- 1) A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1, except that the amount was changed from 3.5 parts to 9.5 parts.

[0174] Example 4 In Example 1, the polyester resin (A-1) was mixed with (A-2) and the crosslinking agent (D-1) was mixed with 3 An adhesive composition was obtained in the same manner as in Example 1, except that 0.5 parts was changed to 6 parts.

[0175] Example 5 In Example 1, the polyester resin (A-1) was replaced with (A-2), and the polyester resin The experiment was carried out except that (B-1) was changed from 50 parts to 100 parts and crosslinking agent (D-1) was changed from 3.5 parts to 10 parts. A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1.

[0176] Example 5 In Example 1, the polyester resin (A-1) was replaced with (A-2), and the polyester resin The test was carried out except that (B-1) was changed from 50 parts to 150 parts and crosslinking agent (D-1) was changed from 3.5 parts to 13 parts. A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1.

[0177] (Comparative Example 1) In Example 1, the polyester plasticizer (B-1) was not added, and the crosslinking agent (D-1) was added in an amount of 300 ml. An adhesive composition was obtained in the same manner as in Example 1, except that 0.5 parts was changed to 1.5 parts.

[0178] (Comparative Example 2) In Example 1, the polyester resin (A-1) was replaced with (A-2), and the polyester plastic The same procedure as in Example 1 was repeated except that the crosslinking agent (B-1) was not added and the amount of the crosslinking agent (D-1) was changed from 3.5 parts to 3 parts. In the same manner as above, a pressure-sensitive adhesive composition was obtained.

[0179] (Comparative Example 3) In Example 1, the polyester resin (A-1) was replaced with (A'-1), and the polyester resin The plasticizer (B-1) was not added, and the cross-linking agent (D-1) was changed from 3.5 parts to 1.5 parts. A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1.

[0180] Comparative Example 4 In Example 1, the polyester resin (A-1) was replaced with (A'-1). A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1.

[0181] (Comparative Example 5) In Example 1, the polyester resin (A-1) was replaced with (A'-1), and the polyester resin Except for changing the plasticizer (B-1) from 50 parts to 100 parts and the crosslinking agent (D-1) from 3.5 parts to 6.5 parts A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1.

[0182] (Comparative Example 6) In Example 1, the polyester resin (A-1) was replaced with (A'-1), and the polyester resin Except for changing the plasticizer (B-1) from 50 parts to 150 parts and the crosslinking agent (D-1) from 3.5 parts to 9.5 parts A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1.

[0183] The adhesive compositions obtained in the above Examples and Comparative Examples were used to prepare adhesive sheets as follows. were prepared and evaluated as follows.

[0184] <Preparation of adhesive sheet with one-sided release film> The pressure-sensitive adhesive compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were applied to a 38 μm-thick PET film. The coating was applied to a film (Toray Industries, Inc., "Lumirror T60") using an applicator and heated at 100°C. After drying for 3 minutes, the adhesive composition layer was attached to a PET film having a thickness of 25 μm and 100 μm. An adhesive sheet was obtained. Next, the surface of the pressure-sensitive adhesive composition layer of the obtained pressure-sensitive adhesive sheet with a PET film was coated with a 38 μm thick film. The sample was covered with a PET release film (Mitsui Chemicals Tocello, SP-PET-01-BU) and 4 Aging treatment was carried out at 0°C for 4 days to obtain a pressure-sensitive adhesive sheet with a release film on one side.

[0185] <Preparation of adhesive sheet with double-sided release film> The pressure-sensitive adhesive compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were applied to a 38 μm-thick PET film. The applicator is placed on a release film (Mitsui Chemicals Tohcello, "SP-PET-03-BU") The adhesive composition was applied using a release agent and dried at 100°C for 3 minutes to form a pressure-sensitive adhesive composition layer having a thickness of 100µm. A pressure-sensitive adhesive sheet with a film was obtained. Next, the surface of the pressure-sensitive adhesive composition layer of the obtained pressure-sensitive adhesive sheet with a release film was coated with a 38 μm thick adhesive sheet. Covered with a PET release film (Mitsui Chemicals Tocello, SP-PET-01-BU), 40 C. for 4 days to obtain a pressure-sensitive adhesive sheet with double-sided release films.

[0186] [Gel fraction] The adhesive sheet with one-sided release film obtained above was cut into a size of 50 mm x 50 mm. After that, the release film was peeled off, the mixture was wrapped in a 200 mesh SUS wire netting, and then soaked in toluene for 2 minutes. The weight of the adhesive component before immersion and the undissolved adhesive remaining in the wire mesh after immersion were measured. The weight of the adhesive component was measured, and the percentage was calculated using the following formula to determine the gel fraction (%). . However, the weight of the substrate was subtracted. Weight of undissolved adhesive component remaining in the wire mesh after immersion / Weight of adhesive component before immersion × 1 00(%)

[0187] (Adhesive sheet evaluation) [Initial adhesive strength] The pressure-sensitive adhesive sheet with one-sided release film obtained above was left in an environment of 23°C and 50% RH for 2 After cutting into a size of 5mm x 200mm, peel off the release film and apply the adhesive layer to a mirror surface. A 2 kg roller was pressed and attached to the finished stainless steel plate (SUS-BA plate) in the same atmosphere. After leaving it to stand for 30 seconds under atmospheric pressure, the sample was analyzed by an autograph (Shimadzu Corporation, Autograph AG- x 50N") at a peel speed of 300 mm / min and a 180-degree peel adhesive strength (N / 25 The evaluation criteria were as follows: (Evaluation criteria) ◎: The strength was greater than 5N / 25mm, and the peeling occurred at the adherend interface. ○: The strength is greater than 3N / 25mm and less than 5N / 25mm, and the peeling state is Interfacial peeling △: The strength is greater than 1N / 25mm and less than 3N / 25mm, and the peeling state is Interfacial peeling × 1N / 25mm or less, or peeling is cohesive peeling or peeling at the substrate interface Ta

[0188] [Shear force measurement] The pressure-sensitive adhesive sheet with double-sided release film obtained above was left in an environment of 23°C and 50% RH for 2 After cutting into a size of 5 mm x 12.5 mm, peel off one of the release films and expose the adhesive layer side. The adhesive layer is then attached to a stainless steel plate, and the other release film is peeled off. The specimen was then laminated to a 50 μm stainless steel foil and pressed at 0.3 MPa for 10 seconds to prepare a test piece. The specimens were cured in the same atmosphere for 48 hours, and then used as measurement samples. Shimadzu Corporation's "Autograph AG-X 5kN" was used, and the peeling speed was 10 mm / m. A tensile test was carried out in the vertical direction at 100 mm, and the shear strength was measured. The evaluation criteria were as follows: be. (Evaluation criteria) ◎ Greater than 1.5 MPa ○: More than 1 MPa and 1.5 MPa or less △: More than 0.5 MPa and less than 1 MPa ×...0.5MPa or less

[0189] [Table 4]

[0190] From the results in Table 4 above, it can be seen that the pressure-sensitive adhesive sheets obtained from the pressure-sensitive adhesive compositions of Examples 1 to 6 had an initial viscosity of It is clear that it is excellent in both adhesion and shear strength. On the other hand, the pressure-sensitive adhesive compositions of Comparative Examples 1 and 2, which do not contain the polyester plasticizer (B), The pressure-sensitive adhesive sheet obtained from this had excellent shear strength but was poor in initial adhesive strength. In addition, the adhesives of Comparative Examples 3 to 6, which used polyester resins with low glass transition temperatures, The adhesive sheet obtained from the adhesive composition has excellent initial adhesive strength but poor shear strength. there were. From the above, it is possible to obtain a polymer having a specific glass transition temperature and further containing a polyester-based plasticizer. The ester-based adhesive composition has well-balanced and excellent adhesive properties when used as an adhesive. We can see that. [Industrial Applicability]

[0191] The pressure-sensitive adhesive composition of the present invention is excellent in initial adhesive strength and shear strength, and therefore The adhesive and adhesive sheet using the same can be used for bonding electronic components. .

Claims

1. A polyester-based pressure-sensitive adhesive composition comprising a polyester-based resin (A) having a structural unit derived from a polycarboxylic acid (a1) and a structural unit derived from a polyol (a2), a polyester-based plasticizer (B), and a crosslinking agent (D), the polyester plasticizer (B) has a structural unit derived from a polycarboxylic acid (b1), a structural unit derived from a polyol (b2), and a structural unit derived from a reactive molecule end-capping agent (b3), and the content of the polyester plasticizer (B) is 10 to 180 parts by weight per 100 parts by weight of the polyester resin (A); A polyester-based pressure-sensitive adhesive composition, characterized in that the polyester-based resin (A) has a glass transition temperature (TgA) of -25 to 35°C and a hydroxyl value of 1 to 30 mgKOH / g.

2. 2. The polyester-based pressure-sensitive adhesive composition according to claim 1, wherein the weight-average molecular weight of the polyester-based resin (A) is 15,000 to 200,000.

3. 3. The polyester-based pressure-sensitive adhesive composition according to claim 1, wherein the polyester-based resin (A) has an acid value of 5 mgKOH / g or less.

4. The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 3, characterized in that the polyester-based plasticizer (B) contains an aromatic structure in at least one of a structural unit derived from a polycarboxylic acid (b1), a structural unit derived from a polyol (b2), and a reactive molecular end-capping agent (b3).

5. 5. The polyester-based pressure-sensitive adhesive composition according to claim 1, wherein the weight-average molecular weight of the polyester-based plasticizer (B) is 1,000 to 12,000.

6. 6. The polyester-based pressure-sensitive adhesive composition according to claim 1, wherein the polyester-based plasticizer (B) has an acid value of 5 mgKOH / g or less.

7. 7. The polyester-based pressure-sensitive adhesive composition according to claim 1, wherein the polyester-based plasticizer (B) has a glass transition temperature (TgB) of -80 to 0°C.

8. 8. The polyester-based pressure-sensitive adhesive composition according to any one of 1 to 7, wherein the glass transition temperature (TgA) of the polyester-based resin (A) is higher than the glass transition temperature (TgB) of the polyester-based plasticizer (B).

9. The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 8, further comprising a hydrolysis inhibitor (C).

10. A polyester-based pressure-sensitive adhesive obtained by crosslinking the polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 9.

11. A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer containing the polyester-based pressure-sensitive adhesive according to claim 10.

12. 11. A pressure-sensitive adhesive sheet comprising a substrate and a pressure-sensitive adhesive layer obtained from the polyester-based pressure-sensitive adhesive according to claim 10, wherein the pressure-sensitive adhesive layer is provided on at least one surface of the substrate.

13. A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer obtained from the polyester-based pressure-sensitive adhesive according to claim 10, characterized in that the pressure-sensitive adhesive sheet is of a substrate-less type having no substrate.

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