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

Abstract

To provide a polyester-based adhesive composition which is excellent in adhesive force to a low polar adherend, and is further excellent in stain resistance and tackiness at the time of peeling of the adherend, when formed into a polyester-based 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).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, and more particularly, to a polyester-based pressure-sensitive adhesive composition, a polyester-based pressure-sensitive adhesive, and a pressure-sensitive adhesive sheet that, when used as a pressure-sensitive adhesive, have excellent adhesive strength to a low-polarity adherend and further have excellent stain resistance and tackiness during peeling of the adherend.

Background Art

[0002] Conventionally, it has been known that a polyester-based resin becomes excellent in chemical resistance, plasticizer resistance, mechanical strength, etc. by combining a polyvalent carboxylic acid component and a polyol component, and it has also been studied in the field of pressure-sensitive adhesives.

[0003] In recent years, with the miniaturization and thinning of parts and members, a pressure-sensitive adhesive is required to have high adhesive strength even in a small area. As a method for improving the adhesive strength, for example, in Patent Document 1, a polyester-based pressure-sensitive adhesive composition obtained by containing a tackifier in a polyester-based resin has been proposed. And in Patent Document 2, a polyester-based pressure-sensitive adhesive composition containing a polyester-based resin and a fatty acid ester has been proposed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, in the disclosed technology of Patent Document 1, a polyester resin is blended with a tackifier having a high softening point such as rosin ester or terpene resin. Generally, it is common to blend a tackifier with a high softening point in order to impart cohesive force at high temperatures. However, such a tackifier has a problem that the tackiness at room temperature decreases. In addition, in the disclosed technology of Patent Document 2, although wettability to an adherend is imparted by blending a fatty acid ester with a polyester resin, such a fatty acid ester has a low molecular weight, so the adhesive force, especially the adhesive force to a low-polarity adherend, is not sufficient, and there still remain problems in terms of stain resistance when peeling from the adherend. Therefore, in the present invention, under such circumstances, when used as an adhesive, a polyester-based adhesive composition is provided which has excellent adhesive force to a low-polarity adherend and is further excellent in stain resistance and tackiness when peeling from the adherend. However, as a result of intensive studies by the present inventor in view of such circumstances, in an adhesive composition containing a polyester resin (A) having a structural unit derived from polycarboxylic acids (a1) and a structural unit derived from polyol (a2), by deliberately mixing a highly polar polyester plasticizer with a highly polar polyester resin, especially when the polyester plasticizer (B) has a structural unit derived from polycarboxylic acids (b1), a structural unit derived from polyol (b2), and a structural unit derived from a reactive molecular end-capping agent (b3), when used as an adhesive

[0006] In addition, in the disclosed technology of Patent Document 2, although wettability to an adherend is imparted by blending a fatty acid ester with a polyester resin, such a fatty acid ester has a low molecular weight, so the adhesive force, especially the adhesive force to a low-polarity adherend, is not sufficient, and there still remain problems in terms of stain resistance when peeling from the adherend. In addition, in the disclosed technology of Patent Document 2, although wettability to an adherend is imparted by blending a fatty acid ester with a polyester resin, such a fatty acid ester has a low molecular weight, so the adhesive force, especially the adhesive force to a low-polarity adherend, is not sufficient, and there still remain problems in terms of stain resistance when peeling from the adherend. Since it is a low molecular weight, the adhesive force, especially the adhesive force to a low-polarity adherend, is not sufficient, and there still remain problems in terms of stain resistance when peeling from the adherend. In addition, there are still problems in terms of stain resistance when peeling from the adherend.

[0007] Therefore, in the present invention, under such circumstances, when used as an adhesive, a polyester-based adhesive composition is provided which has excellent adhesive force to a low-polarity adherend and is further excellent in stain resistance and tackiness when peeling from the adherend. However, as a result of intensive studies by the present inventor in view of such circumstances, in an adhesive composition containing a polyester resin (A) having a structural unit derived from polycarboxylic acids (a1) and a structural unit derived from polyol (a2), by deliberately mixing a highly polar polyester plasticizer with a highly polar polyester resin, especially when the polyester plasticizer (B) has a structural unit derived from polycarboxylic acids (b1), a structural unit derived from polyol (b2), and a structural unit derived from a reactive molecular end-capping agent (b3), when used as an adhesive However, as a result of intensive studies by the present inventor in view of such circumstances, in an adhesive composition containing a polyester resin (A) having a structural unit derived from polycarboxylic acids (a1) and a structural unit derived from polyol (a2), by deliberately mixing a highly polar polyester plasticizer with a highly polar polyester resin, especially when the polyester plasticizer (B) has a structural unit derived from polycarboxylic acids (b1), a structural unit derived from polyol (b2), and a structural unit derived from a reactive molecular end-capping agent (b3), when used as an adhesive

Means for Solving the Problems

[0008] However, as a result of intensive studies by the present inventor in view of such circumstances, in an adhesive composition containing a polyester resin (A) having a structural unit derived from polycarboxylic acids (a1) and a structural unit derived from polyol (a2), by deliberately mixing a highly polar polyester plasticizer with a highly polar polyester resin, especially when the polyester plasticizer (B) has a structural unit derived from polycarboxylic acids (b1), a structural unit derived from polyol (b2), and a structural unit derived from a reactive molecular end-capping agent (b3), when used as an adhesive a polyester resin (A) having a structural unit derived from polycarboxylic acids (a1) and a structural unit derived from polyol (a2), in an adhesive composition containing a polyester resin (A) having a structural unit derived from polycarboxylic acids (a1) and a structural unit derived from polyol (a2), by deliberately mixing a highly polar polyester plasticizer with a highly polar polyester resin, especially when the polyester plasticizer (B) has a structural unit derived from polycarboxylic acids (b1), a structural unit derived from polyol (b2), and a structural unit derived from a reactive molecular end-capping agent (b3), when used as an adhesive by deliberately mixing a highly polar polyester plasticizer with a highly polar polyester resin, especially when the polyester plasticizer (B) has a structural unit derived from polycarboxylic acids (b1), a structural unit derived from polyol (b2), and a structural unit derived from a reactive molecular end-capping agent (b3), when used as an adhesive a polyester plasticizer (B) having a structural unit derived from polycarboxylic acids (b1), a structural unit derived from polyol (b2), and a structural unit derived from a reactive molecular end-capping agent (b3), and when used as an adhesive When applied, it has excellent adhesion to low-polarity adherends, stain resistance during adherend peeling, and tackiness. A polyester-based pressure-sensitive adhesive composition was obtained, and the present invention was completed.

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

[15] . [1] A polyester-based resin (A) having a structural unit derived from polycarboxylic acids (a1) and a structural unit derived from polyol (a2), and a polyester-based plasticizer (B). A polyester-based pressure-sensitive adhesive composition, wherein the polyester-based plasticizer (B) is a polycarboxylic acid (b1) -derived structural unit, a structural unit derived from polyol (b2), and a structural unit derived from a reactive molecular end-capping agent (b3). The polyester-based pressure-sensitive adhesive composition is characterized by having these. [2] The polyester-based adhesive composition according to [1], wherein the weight average molecular weight of the polyester-based resin (A) is 15,000 to 200,00 0. [3] The polyester-based pressure-sensitive adhesive composition according to [1] or [2], wherein the glass transition temperature (TgA) of the polyester-based resin (A) is -80 to -25 °C . [4] The polyester-based pressure-sensitive adhesive composition according to any one of [1] to [3], wherein the acid value of the polyester-based resin (A) is 5 mgKOH / g or less. [5] The polyester-based pressure-sensitive adhesive composition according to any one of [1] to [4], wherein the weight average molecular weight of the polyester-based plasticizer (B) is 1,000 to 12,000 . [6] The polyester-based pressure-sensitive adhesive composition according to any one of [1] to [5], wherein the content of the polyester-based plasticizer (B) is 0.1 to 150 parts by weight with respect to 100 parts by weight of the polyester-based resin (A). ​ [7] The polyester-based pressure-sensitive adhesive composition according to any one of [1] to [6], characterized in that the acid value of the above polyester-based plasticizer (B) is 5 mgKOH / g or less. [8] The polyester-based pressure-sensitive adhesive composition according to any one of [1] to [7], characterized in that the glass transition temperature (TgB) of the above polyester-based plasticizer (B) is -80 to 0 °C. [9] The polyester-based pressure-sensitive adhesive composition according to any one of [1] to [8], characterized in that the glass transition temperature (TgA) of the above polyester-based resin (A) is lower than the glass transition temperature (TgB) of the polyester-based plasticizer (B).

[10] The polyester-based pressure-sensitive adhesive composition according to any one of [1] to [9], characterized by containing a hydrolysis inhibitor (C).

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

[10] , characterized by containing a crosslinking agent (D).

[12] A polyester-based pressure-sensitive adhesive, characterized in that the polyester-based pressure-sensitive adhesive composition according to any one of [1] to

[11] is crosslinked.

[13] An adhesive sheet, characterized by having an adhesive layer containing the polyester-based pressure-sensitive adhesive described in

[12] .

[14] An adhesive sheet having an adhesive layer obtained from the polyester-based pressure-sensitive adhesive described in

[12] and a base material, characterized in that the adhesive layer is provided on at least one side of the base material.

[15] An adhesive sheet having an adhesive layer obtained from the polyester-based pressure-sensitive adhesive described in

[12] , which is a base-material-less type without a base material.

[0010] In adhesives, generally, in order to improve the adhesive force to the adherend and wettability, an adhesion promoter is added. An agent and a plasticizer are blended. In this case, in order to enhance the cohesive force of the main agent, a tackifying resin with a low molecular weight and a high softening point may be blended, or a low molecular weight ester-based plasticizer may be blended. However, in the present invention, by blending a polyester-based plasticizer having a repeating structural unit composed of an ester bond having a high polarity, unexpectedly, it has excellent compatibility with the main agent, does not cause bleeding, and when used as an adhesive, has excellent tackiness, stain resistance, and further has excellent adhesive force to a low polarity adherend, and an adhesive composition can be obtained.

Advantages of the Invention

[0011]

Modes for Carrying Out the Invention

[0012] The polyester-based adhesive composition of the present invention is a polyester-based adhesive containing a polyester-based resin (A) and a polyester-based plasticizer (B), wherein the polyester-based resin (A) has a structural unit derived from polycarboxylic acids (a1) and a structural unit derived from polyols (a2), and the polyester-based plasticizer (B) has a structural unit derived from polycarboxylic acids (b1), a structural unit derived from polyols (b2), and a structural unit derived from a reactive molecular end-capping agent (b3).

[0013] ​​​​​​​​​​Hereinafter, each constituent component used in the polyester-based pressure-sensitive adhesive composition of the present invention will be described in detail. 。

[0014] <Polyester resin (A)> The polyester resin that can be used in the present invention is obtained by copolymerizing a copolymer component containing polyvalent carboxylic acids (a1) and polyols (a2), and the polyester resin has a structural unit derived from polyvalent carboxylic acids (a1) and a structural unit derived from polyols (a2) as its resin composition. In addition, in the present invention, the term "carboxylic acids" includes, in addition to carboxylic acids, carboxylic acid salts, carboxylic anhydrides, carboxylic acid halides, carboxylic acid esters and other carboxylic acid derivatives such as conductors.

[0015] [Structural unit derived from polyvalent carboxylic acids (a1)] Examples of the structural unit derived from the polyvalent carboxylic acids (a1) include, for example, structural units derived from divalent carboxylic acids and structural units derived from polyvalent carboxylic acids having a trivalent or higher valence. From the viewpoint of stably obtaining a polyester resin, it is preferable to include a structural unit derived from a divalent carboxylic acid. The polyvalent carboxylic acids (a1) can be used alone or in combination of two or more. 。

[0016] Examples of the structural unit derived from the divalent carboxylic acids include, for example, malonic acids, dimethylmalonic acids, succinic acids, glutaric acids, adipic acids, trimethyladipic acids, pimelic acids, 2,2-dimethylglutaric acids, azelaic acids, sebacic acids, fumaric acids, maleic acids, itaconic acids, thiodipropionic acids, diglycolic acids, 1,9-nonanedicarboxylic acids and other structural units derived from aliphatic dicarboxylic acids;​​ Phthalic acids, terephthalic acids, isophthalic acids, benzylmalonic acids, diphenic acids, 4,4'-oxydibenzoic acids, and further structural units derived from aromatic dicarboxylic acids such as 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, 2,6-naphthalenedicarboxylic acids, 2,7-naphthalenedicarboxylic acids, etc.; Structural units derived from alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acids, 1,2-cyclohexanedicarboxylic acids, 1,3-cyclopentanedicarboxylic acids, 1,4-cyclohexanedicarboxylic acids, 2,5-norbornanedicarboxylic acids, adamantanedicarboxylic acids, etc.; Structural units derived from dimer acids (mainly those having 36 to 44 carbon atoms) derived from oleic acid, linoleic acid, linolenic acid, erucic acid, etc.; and the like. Also, as the structural units derived from the above trivalent or higher polycarboxylic acids, for example, structural units derived from trimellitic acids, pyromellitic acids, adamantanetricarboxylic acids, trimesic acids, etc. can be mentioned. These structural units derived from the polycarboxylic acids (a1) may be possessed alone or may have two or more structural units. Among these structural units derived from the polycarboxylic acids (a1), from the viewpoint of lowering the crystallinity of the polyester resin and excellent cohesive force, it is preferable to include structural units derived from aromatic polycarboxylic acids, particularly structural units derived from asymmetric aromatic dicarboxylic acids (a1-1). Examples of the structural units derived from the asymmetric aromatic dicarboxylic acids (a1-1) include phthalic acids, isophthalic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, etc. These structural units derived from the polycarboxylic acids (a1) may be possessed alone or may have two or more structural units. Among these structural units derived from the polycarboxylic acids (a1), from the viewpoint of lowering the crystallinity of the polyester resin and excellent cohesive force, it is preferable to include structural units derived from aromatic polycarboxylic acids, particularly structural units derived from asymmetric aromatic dicarboxylic acids (a1-1). Examples of the structural units derived from the asymmetric aromatic dicarboxylic acids (a1-1) include phthalic acids, isophthalic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, etc. These structural units derived from the polycarboxylic acids (a1) may be possessed alone or may have two or more structural units.

[0017] Among these structural units derived from the polycarboxylic acids (a1), from the viewpoint of lowering the crystallinity of the polyester resin and excellent cohesive force, it is preferable to include structural units derived from aromatic polycarboxylic acids, particularly structural units derived from asymmetric aromatic dicarboxylic acids (a1-1). Examples of the structural units derived from the asymmetric aromatic dicarboxylic acids (a1-1) include phthalic acids, isophthalic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, etc. Examples of the structural units derived from the asymmetric aromatic dicarboxylic acids (a1-1) include phthalic acids, isophthalic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, etc. Examples of structural units include those derived from acids, 2,7-naphthalenedicarboxylic acids, etc. Among them, it is particularly preferable to contain a structural unit derived from isophthalic acids in terms of reactivity.

[0018] The content of the structural unit derived from such aromatic polycarboxylic acids, particularly the structural unit derived from asymmetric aromatic dicarboxylic acids (a1-1), is preferably 0.1 to 70 mol%, more preferably 0.5 to 60 mol%, with respect to the total structural unit derived from polycarboxylic acids (a1). Even more preferably, it is 1 to 50 mol%, particularly preferably 2 to 40 mol%, especially preferably 3 to 30, and most preferably 5 to 25 mol%. If such content is too low, the cohesive force may decrease, the polyester resin may crystallize, and it may be difficult to obtain sufficient adhesive performance. On the other hand, if such content is too high, the tackiness tends to decrease.

[0019] In the present invention, from the viewpoint of improving the tackiness, as the structural unit derived from polycarboxylic acids (a1), it is preferable to contain a structural unit derived from aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms (including the carbon of the carboxy group). Among them, it is more preferable to contain aliphatic dicarboxylic acids having 6 to 12 carbon atoms (including the carbon of the carboxy group), and it is particularly preferable to contain a structural unit derived from adipic acids, sebacic acids, and azelaic acids.

[0020] Regarding the content of the structural unit derived from such aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms, it is preferably 5 to 100 mol%, more preferably 20 to 99 mol%, and even more preferably 40 to 98 mol% with respect to the total structural unit derived from polycarboxylic acids (a1). , particularly preferably 60 to 97 mol%, especially preferably 70 to 95 mol%. If the content is too low, the glass transition temperature of the polyester resin becomes too high and the tackiness tends to be low. If the content is too high, the cohesive force tends to decrease or the polyester resin tends to crystallize and sufficient adhesive performance cannot be obtained. When the content is too small, the glass transition temperature of the polyester resin becomes too high and the tackiness tends to be low. When the content is too large, the cohesive force tends to decrease or the polyester resin tends to crystallize and sufficient adhesive performance cannot be obtained.

[0021] In the present invention, from the viewpoint of adhesive physical properties, as the structural unit derived from polycarboxylic acids (a1), the structural unit derived from asymmetric aromatic dicarboxylic acids (a1-1) and the structural unit derived from aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms are preferably included. In that case, the content ratio (molar ratio) of the structural unit derived from asymmetric aromatic dicarboxylic acids (a1-1) to the structural unit derived from aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms is preferably (a1-1) / (a1-2)=0.1 / 99.9 to 70 / 30, more preferably 0.5 / 99.5 to 60 / 40, still more preferably 1 / 99 to 50 / 50, particularly preferably 2 / 98 to 40 / 60, especially preferably 3 / 97 to 30 / 70, and most preferably 5 / 95 to 25 / 75.

[0022] Further, in the present invention, for the purpose of increasing the number of branch points in the polyester resin, a structural unit derived from a polycarboxylic acid (a1-3) having a trivalent or higher valence may be included. Among them, a structural unit derived from trimellitic acids is preferably included in that gelation is less likely to occur during production.

[0023] As the content of the structural unit derived from such a polycarboxylic acid (a1-3) having a trivalent or higher valence, from the viewpoint of increasing the cohesive force when used as an adhesive, the structure derived from polycarboxylic acids (a1) For the entire production unit, preferably 10 mol% or less, particularly preferably 0.1 to 5 mol%, especially preferably 0.5 to 3 mol%. If such a content is too high, gelation tends to occur during the production of the polyester resin, and the acid value tends to increase.

[0024] [Structural unit derived from polyol (a2)] Examples of the structural unit derived from polyol (a2) include the structural unit derived from a dihydric alcohol and the structural unit derived from a polyol having a trivalent or higher valence. Polyol (a2) can be used alone or in combination of two or more species.

[0025] Examples of the structural unit derived from the above dihydric alcohol include, for example, ethylene glycol, diethylene 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, etc., which are structural units derived from aliphatic diols; Structural units derived from alicyclic diols such as 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4 -cyclohexanedimethanol, spiroglycol, tricyclodecanedimethanol, adamantane diol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, etc. ; 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4 -cyclohexanedimethanol, spiroglycol, tricyclodecanedimethanol, adamantane diol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, etc. of alicyclic diols; ​ 4,4'-Thiodiphenol, 4,4'-methylenediphenol, 4,4'-dihydro xybiphenyl, o-, m-, and p-dihydroxybenzene, 2,5-naphthalenedi ol, p-xylenediol, and structural units derived from aromatic diols such as their ethylene oxide adducts and propylene oxide adducts. Furthermore, structural units derived from fatty acid esters derived from castor oil, and structural units derived from dimer diols derived from oleic acid, linoleic acid, linolenic acid, and erucic acid, and structural units derived from glycerol monostearate. In addition, examples of the structural units derived from the above polyhydric alcohols having three or more valences include pentaerythritol, dipentaerythritol, tripentaerythritol, glycerin, trimethylolpropane, trimethylolethane, 1,2,4-butanetriol, 1,2,5-pentanetriol, 1,2,6-hexanetriol, 1,3,6-hexanetriol, and structural units derived from adamantanetriol. These structural units derived from the polyhydric alcohol (a2) may be possessed alone, or may have two or more kinds of structural units.

[0026] In the present invention, from the viewpoint of lowering the glass transition temperature of the polyester resin and improving the tackiness, as the structural unit derived from the polyhydric alcohol (a2), it is preferable to contain a structural unit derived from a linear aliphatic diol (a2-1), more preferably, it is to contain a structural unit derived from a linear aliphatic diol having 2 to 18 carbon atoms, and particularly preferably, it is to contain a structural unit derived from ethylene glycol, 1,4-butanediol, or 1,6-hexanediol.

[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 Examples thereof include units and structural units derived from dimer diols derived from units, oleic acid, erucic acid, etc. Among them, 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 opentyl glycol), structural units derived from 3-methyl-1,5-pentanediol are particularly preferred.

[0029] The content of the structural unit derived from the diol (a2-2) having a hydrocarbon group in the side chain is preferably 5 to 95 mol% based on the total structural units derived from the polyol (a2), more preferably 10 to 90 mol%, still more preferably 15 to 80 mol%, particularly preferably 20 to 70 mol%, especially preferably 30 to 60 mol%. If such a content is too small, the resin tends to crystallize and it is difficult to obtain sufficient adhesive performance. If it is too large, the reaction time tends to be long in the production of polyester resins.

[0030] Furthermore, in the present invention, from the viewpoint of forming a reaction point with the crosslinking agent (D) described later in the polyester resin and increasing the cohesive force, as the structural unit derived from the polyol (a2), a structural unit derived from a polyol (a2-3) having a trivalent or higher valence is also preferably included. Among the structural units derived from the polyol (a2-3) having a trivalent or higher valence, structural units derived from trimethylolpropane, trimethylolethane, glycerin, pentaerythritol, 1,2,4-butanetriol, 1,2,5- pentanetriol, 1,2,6-hexanetriol are preferred, and it is particularly preferred that the structural unit derived from trimethylolpropane is included in terms of relatively low gel generation. (a2-3)

[0031] The content of the structural unit derived from such polyol (a2-3) having a valence of three or more is preferably 10 mol% or less, more preferably 0.1 to 5 mol%, still more preferably 0.5 to 3 mol%, based on the total structural units derived from polyol (a2). If the content of the structural unit derived from such polyol having a valence of three or more is too large, the production of the polyester resin tends to be difficult. Here, the ratio (composition ratio) of the structural units derived from each component of the polyester resin can be determined by, for example, NMR. The polyester resin used in the present invention is produced by appropriately selecting the above polycarboxylic acids (a1) and polyol (a2) within the above content ranges and subjecting them to a polycondensation reaction by a known method in the presence of a catalyst. As for the blending ratio of the above polycarboxylic acids (a1) and polyol (a2), it is preferable that the polyol (a2) is 1 to 2 equivalents per equivalent of the polycarboxylic acids (a1), particularly preferably 1.1 to 1.7 equivalents. If the blending ratio of the polyol (a2) is too low, the acid value tends to be high and it becomes difficult to increase the molecular weight. If it is too high, the yield tends to decrease. In the polycondensation reaction, first, an esterification reaction is carried out, and then a polycondensation reaction is carried out.

[0032] In such an esterification reaction, a catalyst is usually used. Specifically, for example, titanium-based catalysts such as tetra-isopropyl titanate and tetra-butyl titanate, antimony trioxide

[0033]

[0034]

[0035]

[0036] Catalysts such as antimony-based catalysts and germanium-based catalysts such as germanium dioxide, and zinc acetate Catalysts such as lead acetate, manganese acetate, and dibutyltin oxide can be mentioned, and one of these or two or more thereof are used. Among these, from the balance of high catalytic activity and hue, antimony trioxide, tetrabutyl titanate, germanium dioxide, and zinc acetate are preferred.

[0037] The compounding amount of the catalyst is preferably 1 to 10,000 ppm based on weight with respect to all the copolymerization components, particularly preferably 10 to 5,000 ppm, and more preferably 20 to 3,000 ppm. If such a compounding amount is too small, the polymerization reaction tends not to proceed sufficiently, and if it is too large, there are no advantages such as shortening of the reaction time and side reactions tend to occur.

[0038] Regarding the reaction temperature during the esterification reaction, 200 to 300 °C is preferred, particularly preferably 210 to 280 °C, and more preferably 220 to 260 °C. If such a reaction temperature is too low, the reaction tends not to proceed sufficiently, and if it is too high, side reactions such as decomposition tend to occur. Also, the pressure during the reaction is usually under normal pressure.

[0039] After the above esterification reaction is carried out, a polycondensation reaction is carried out. As the reaction conditions for the polycondensation reaction, a catalyst similar to that used in the above esterification reaction is further compounded in an amount of about the same degree, and the reaction temperature is preferably 220 to 280 °C, particularly preferably 23 0 to 270 °C, and the reaction system is gradually depressurized and finally reacted at 5 hPa or less. If such a reaction temperature is too low, the reaction tends not to proceed sufficiently, and if it 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] From the viewpoint of adhesive physical properties, the glass transition temperature (TgA) of the above polyester resin (A) is usually -80 to -25°C, preferably -75 to -30°C, more preferably -70 to -3 5°C, even more preferably -65 to -40°C, particularly preferably -60 to -45°C. If such a glass transition temperature (TgA) is too high, flexibility is lost, tackiness decreases, and it becomes difficult to exhibit adhesive strength under finger pressure level pressure, and workability tends to decrease. If it is too low, the cohesive force tends to decrease.

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

[0044] Also, from the viewpoint of adhesive physical properties, the glass transition temperature (TgA) of the above polyester resin (A) is preferably lower than the glass transition temperature (TgB) of the polyester plasticizer (B) described later. Furthermore, it is more preferable that the glass transition temperature of the polyester resin (A) is 3 to 80°C lower than the glass transition temperature of the polyester plasticizer (B), even more preferably 5 to 60°C lower, particularly preferably 10 to 40°C lower, and extremely preferably 15 to 30°C lower. By setting it within the above range, an adhesive excellent in adhesive strength and tackiness to a low-polarity adherend can be obtained. ​​​​​It is possible.

[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, 000, and particularly preferably 50,000 to 120,000. This makes it possible to obtain a pressure-sensitive adhesive that is excellent in heat resistance, mechanical strength, and adhesion to substrates. If the weight average molecular weight is too small, the adhesive will not have sufficient cohesive strength, and the heat resistance and The mechanical strength tends to decrease. In addition, if the weight average molecular weight is too large, the adhesion to the substrate may decrease. Adhesion tends to decrease.

[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 tends to decrease. Also, if the number average molecular weight is too large, the adhesion to the substrate tends to decrease. Incidentally, the number average molecular weight can be measured by the same method as the weight average molecular weight of the polyester resin (A) described above.

[0048] In addition, the hydroxyl value of the polyester resin (A) is preferably 0.1 to 50 mgKOH / g, more preferably 1 to 30 mgKOH / g, still more preferably 2 to 20 mgKOH / g, and particularly preferably 3 to 15 mgKOH / g. If the hydroxyl value is too high, 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, more preferably 5 mgKOH / g or less, still more preferably 3 mgKOH / g or less, particularly preferably 1 mgKOH / g or less, especially preferably 0.5 mgKOH / g or less, and most preferably 0.3 mgKOH / g or less. By setting it within the above range, hydrolysis of the polyester resin (A) is suppressed, and the stain resistance at the time of adherend peeling is excellent. Furthermore, corrosion in the case of laminating to a metal or the like can be suppressed. If the acid value is too high, hydrolysis tends to proceed, and there is a tendency to cause corrosion when a layer of metal or the like is laminated on one surface of the adhesive layer.

[0050] Here, the hydroxyl value and acid value in the present invention are determined by neutralization titration based on JIS K 0070.

[0051] <Polyester plasticizer (B)> ​​​​​​​The above polyester plasticizer (B) exhibits the effects of a plasticizer and contains structural units derived from polycarboxylic acids (b1), structural units derived from polyols (b2), and structural units derived from reactive molecular terminal blocking agents (b3). For example, it is one in which at least one reactive molecular terminal of a polyester resin is blocked by a reactive molecular terminal blocking agent (b3). It has structural units derived from polycarboxylic acids (b1), structural units derived from polyols (b2), and structural units derived from reactive molecular terminal blocking agents (b3). For example, it is one in which at least one reactive molecular terminal of a polyester resin is blocked by a reactive molecular terminal blocking agent (b3). It exists. Moreover, it is preferable that at least one of the structural unit derived from the above polycarboxylic acids (b1), the structural unit derived from the above polyol (b2), and the reactive molecular terminal blocking agent (b3) contains an aromatic structural unit in terms of excellent adhesiveness, tackiness, and stain resistance. It is more preferable that the structural unit derived from polycarboxylic acids (b1) and / or the reactive molecular terminal blocking agent (b3) contains an aromatic structural unit, and it is particularly preferable that the reactive molecular terminal blocking agent (b3) contains an aromatic structural unit.

[0052] The above polyester plasticizer (B) is obtained by blocking the reactive molecular terminals of a polyester plasticizer having at least one of a carboxy group terminal derived from polycarboxylic acids (b1) and a hydroxyl group terminal derived from polyols (b2) as reactive molecular terminals with a reactive molecular terminal blocking agent (b3) described later. Hereinafter, the polyester plasticizer (B') before blocking the reactive molecular terminals (hereinafter, may be referred to as "the polyester plasticizer (B') before terminal blocking") will be described.

[0053] 〔The polyester plasticizer (B') before terminal blocking〕 The above polyester plasticizer (B') before terminal blocking is usually obtained by copolymerizing a copolymerization component containing polycarboxylic acids (b1) and polyols (b2) as constituent raw materials. ​​​​​​​​​​​Moreover, such polyester plasticizer (B') before terminal blocking has structural units derived from polycarboxylic acids (b1) and structural units derived from polyols (b2) in its resin composition.

[0054] 〔Structural units derived from polycarboxylic acids (b1)〕 Examples of the structural units derived from the polycarboxylic acids (b1) include the same ones as those described for the structural units derived from the polycarboxylic acids (a1).

[0055] Among the structural units derived from the polycarboxylic acids (b1), in terms of reducing the crystallinity of the polyester resin and excellent adhesion body contamination, structural units derived from aromatic polycarboxylic acids, particularly structural units derived from asymmetric aromatic dicarboxylic acids (b1-1) are preferably included. Examples of the structural units derived from the asymmetric aromatic dicarboxylic acids (b1-1) include, for example, structural units derived from phthalic acids, isophthalic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, 2,7-naphthalenedicarboxylic acids, etc. Among them, the structural units derived from isophthalic

[0056] acids are particularly preferred in terms of reactivity. The content of such structural units derived from aromatic polycarboxylic acids, particularly structural units derived from asymmetric aromatic dicarboxylic acids (b1-1), is preferably 0.1 to 100 mol% with respect to the total structural units derived from polycarboxylic acids (b1), more preferably 1 to 80 mol%, even more preferably 3 to 70 mol%, particularly preferably 5 to 60 mol%, even more preferably 10 to 55 mol%. If such content is too low, the cohesive force may decrease,​ If there is too much, the tackiness tends to decrease.

[0057] Also, as a structural unit derived from the polyvalent carboxylic acids (b1), from the viewpoint of improving the tackiness, it is preferable to contain a structural unit derived from an aliphatic dicarboxylic acid (b1-2) having 4 or more carbon atoms (including the carbon of the carboxy group), and more preferably to contain a structural unit derived from an aliphatic dicarboxylic acid having 6 to 12 carbon atoms (including the carbon of the carboxy group), and particularly preferably to contain a structural unit derived from adipic acids, sebacic acids, azelaic acids.

[0058] Regarding the content of the structural unit derived from such aliphatic dicarboxylic acids (b1-2) having 4 or more carbon atoms, it is preferably 10 to 100 mol% with respect to the total structural unit derived from polyvalent carboxylic acids (b1). In particular, it is preferably 20 to 95 mol%, more preferably 30 to 90 mol%, and particularly preferably 40 to 80 mol%. If the content is too small, the glass transition temperature of the polyester plasticizer (B) becomes too high, and there is a tendency that sufficient adhesiveness cannot be obtained. Note that if the content is within the preferable range, the crystallization of the polyester plasticizer (B) is suppressed, and there is a tendency that the tackiness of the adhesive is excellent.

[0059] In the present invention, from the viewpoint of adhesive physical properties, as a structural unit derived from polyvalent carboxylic acids (b1), it is also preferable to contain a structural unit derived from an asymmetric aromatic dicarboxylic acid (b1-1) and a structural unit derived from an aliphatic dicarboxylic acid (b1-2) having 4 or more carbon atoms. In that case, the structural unit derived from the asymmetric aromatic dicarboxylic acid (b1-1) and the aliphatic di The content ratio (molar ratio) with the structural unit derived from carboxylic acids (b1-2) is (b1-1) / ( b1-2) is preferably from 1 / 99 to 99 / 1, particularly preferably from 5 / 95 to 90 / 10, more preferably from 20 / 80 to 80 / 20, and especially preferably from 30 / 70 to 70 / 30.

[0060] Also, for the purpose of increasing the branching points in the polyester resin, a structural unit derived from a polyvalent carboxylic acid of trivalent or higher ( b1-3) can be used. Among them, it is preferable to use trimellitic acids in that gelation is less likely to occur during production.

[0061] The content of the structural unit derived from such a polyvalent carboxylic acid of trivalent or higher (b1-3) is preferably 10 mol% or less, particularly preferably 5 mol% or less, especially preferably 3 mol % or less, and most preferably 1 mol% or less, in terms of being able to increase the cohesive force when used as an adhesive, relative to the total polyvalent carboxylic acids (b1). If such a content is too high, gelation tends to occur during the production of the polyester resin, or the acid value tends to increase.

[0062] [Polyol (b2)] As the structural unit derived from the above polyol (b2), those similar to those described as the structural unit derived from the above polyol (a2) can be mentioned.

[0063] As the structural unit derived from the above polyol (b2), in terms of lowering the glass transition temperature (TgB) of the polyester plasticizer (B) and improving the tackiness, it may contain a structural unit derived from a linear aliphatic diol (b2-1), more preferably, it contains a structural unit derived from a linear aliphatic diol having 2 to 18 carbon atoms , and particularly preferably ethylene glycol ​ It contains structural units derived from 1,3 - propanediol, 1,4 - butanediol, 1,5 - pentanediol, 1,6 - hexanediol, and the like in the recall. It is to contain structural units derived from aliphatic diols (b2 - 1) having a linear structure.

[0064] The content of the structural units derived from the aliphatic diol (b2 - 1) having a linear structure is preferably 1 to 80 mol%, more preferably 3 to 60 mol%, still more preferably 5 to 40 mol%, and particularly preferably 10 to 30 mol% with respect to the total structural units derived from the polyol (b2). If such a content is too large, the polyester - based resin tends to crystallize, and sufficient adhesive performance may not be obtained.

[0065] Also, among the structural units derived from the above - mentioned polyol (b2), since it is possible to disrupt crystallinity it is preferable to contain structural units derived from a diol (b2 - 2) having a hydrocarbon group in the side chain. As the structural units derived from the diol (b2 - 2) having a hydrocarbon group, those described for the diol (a2 - 2) having a hydrocarbon group can be mentioned. Among them, it is preferable to contain structural units derived from an aliphatic diol having a branched structure, and particularly preferably to contain structural units derived from 2 - methyl - 1,3 - propanediol, 2,2 - dimethyl - 1,3 - propanediol (neopentyl glycol), 3 - methyl - 1,5 - pentanediol.

[0066] The content of the structural units derived from the diol (b2 - 2) having a hydrocarbon group in the side chain is preferably 5 to 100 mol%, particularly preferably 15 to 100 mol%, still more preferably 30 to 100 mol%, and most preferably is 45 to 100 mol%, most preferably 60 to 100 mol%. If the content is too low, the polyester plasticizer (B) tends to crystallize, and the tackiness of the adhesive tends to decrease. There is.

[0067] Furthermore, as the structural unit derived from the polyol (b2), a structural unit derived from a polyol (b2- 3) may be included. The content of the structural unit derived from such a polyol (b2-3) of trivalent or higher is preferably 10 mol% or less, more preferably 0.01 to 5 mol%, particularly preferably 0.0 5 to 3 mol%, and especially preferably 0.1 to 1 mol% with respect to the total structural unit derived from the polyol (b2). If the content of the structural unit derived from such a polyol (b2-3) of trivalent or higher is too large, the tackiness tends to decrease. There is a tendency. When the content of the structural unit derived from the polyol (b2-3) of trivalent or higher is too large, there is a tendency for the tackiness to decrease. There is a tendency.

[0068] By reacting the above polycarboxylic acids (b1) and polyol (b2) by a method according to the method for producing the above polyester resin, a polyester plasticizer ( B’) before end-capping is obtained. There is obtained.

[0069] Incidentally, as the blending ratio of the polycarboxylic acids (b1) and polyol (b2) of the polyester plasticizer (B’) before end-capping, when the polyester resin (B’) having a hydroxyl group terminal is used, it is preferable that the polyol (b2) is 1 to 2 equivalents per 1 equivalent of the polycarboxylic acids (b1), particularly preferably 1.03 to 1.8 equivalents, more preferably 1.05 to 1.7, and especially preferably 1.1 to 1.6. If the blending ratio of the polyol (b2) is too low, the compatibility with the polyester resin (A) tends to decrease, and if it is too high, there is a tendency for the compatibility with the polyester resin (A) to decrease. If the blending ratio of the polyol (b2) is too high, there is a tendency for the compatibility with the polyester resin (A) to decrease. As an adhesive, the cohesive force decreases, and the adhesive force and stain resistance tend to decrease. When using a polyester-based plasticizer (B') before end-capping having a carboxy terminal , it is preferable that the polyvalent carboxylic acids (b1) are 1 to 2 equivalents per 1 equivalent of the polyol (b2), particularly preferably 1.03 to 1.8 equivalents, more preferably 1.05 to 1 .7, especially preferably 1.1 to 1.6. If the blending ratio of the polyvalent carboxylic acids (b1) is too low, the compatibility with the polyester resin (A) tends to decrease, and if it is too high, as an adhesive, the cohesive force decreases, and the adhesive force and stain resistance tend to decrease.

[0070] The polyester-based plasticizer (B') before end-capping thus obtained usually has at least one of a carboxy group terminal derived from the polyvalent carboxylic acids (b1) and a hydroxyl group terminal derived from the polyol (b2) as a reactive molecular terminal, and it is more preferable to have a hydroxyl group terminal from the viewpoint of hydrolysis resistance.

[0071] The glass transition temperature (TgB') of the polyester-based plasticizer (B') before end-capping is usually -80 to 30 °C, preferably -75 to 20 °C, more preferably -70 to 0 °C, particularly preferably -65 to -20 °C, especially preferably -60 to -40 °C from the viewpoint of adhesive physical properties. If such a glass transition temperature (TgB) is too high, flexibility is lost, tackiness decreases, and it becomes difficult to exhibit adhesive force with a pressure of about finger pressure, and the workability tends to decrease. If it is too low, the cohesive force decreases, and the adhesive sheet tends to deform and the appearance is damaged. It should be noted that the glass transition temperature of the polyester-based plasticizer (B') before end-capping is the same as that of the polyester Measured by the same method as the glass transition temperature of the polyester resin described by the terephthalic resin (A). It can be done.

[0072] In addition, the number average molecular weight of the polyester plasticizer (B') before end-capping is usually 200 to 12,000, preferably 300 to 10,000, particularly preferably 400 to 8,000, more preferably 600 to 6,000, particularly preferably 800 to 5,000, and even more preferably 1,000 to 4,000. If the number average molecular weight is too small, sufficient cohesive force cannot be obtained as an adhesive, and the adhesive strength and stain resistance tend to decrease easily. On the other hand, if the number average molecular weight is too large, the compatibility with the polyester resin (A) tends to decrease . Note that the number average molecular weight can be measured by the same method as the weight average molecular weight of the polyester resin described by the polyester resin (A). In addition, the weight average molecular weight of the polyester plasticizer (B') before end-capping is 800 to 12,000 from the viewpoint of the cohesive force of the adhesive. Preferably it is 1,000 to 10,000 , particularly preferably 1,500 to 8,000, more preferably 2,000 to 7,500, particularly preferably 2,500 to 7,000, and even more preferably 3,000 to 6,500. If the weight average molecular weight is too small, sufficient cohesive force cannot be obtained as an adhesive when using the polyester plasticizer (B) as a plasticizer, and the adhesive strength and stain resistance tend to decrease easily

[0073] . On the other hand, if the weight average molecular weight is too large, the compatibility with the polyester resin (A) tends to decrease . Note that the weight average molecular weight is described by the polyester resin (A) above and can be measured by the same method. . If the weight average molecular weight is too small, sufficient cohesive force cannot be obtained as an adhesive when using the polyester plasticizer (B) as a plasticizer, and the adhesive strength and stain resistance tend to decrease easily. In addition, if the weight average molecular weight is too large, the compatibility with the polyester resin (A) tends to decrease . Note that the weight average molecular weight is described by the polyester resin (A) above and can be measured by the same method. ​It can be measured by the same method as the weight average molecular weight of the polyester resin.

[0074] The hydroxyl value of the polyester plasticizer (B') before end-capping is the terminal having a hydroxyl group terminal. When it is the polyester plasticizer (B') before end-capping, it is 5 to 200 mgKOH / 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 force tends to decrease, and if it is too low, the compatibility with the polyester resin (A) tends to decrease. Also, when it is the polyester plasticizer (B') before end-capping having a carboxyl group terminal is 10 mgKOH / g or less, preferably 5 mgKOH / g or less, more preferably is 3 mgKOH / g or less, particularly preferably 1 mgKOH / g or less, especially 0.5 mgKO H / g or less. The lower limit is 0.0 mgKOH / g. If the hydroxyl value is too high, the tack tends to decrease.

[0075] The acid value of the polyester plasticizer (B') before end-capping is the end-capping having a hydroxyl group terminal. When it is the polyester plasticizer (B') before end-capping, it is 10 mgKOH / g or less, preferably 5 mgKOH / g or less, more preferably 3 mgKOH / g or less, particularly preferably 1 mgKOH / g or less, especially 0.5 mgKOH / g or less. The lower limit is 0.0 mg KOH / g. If the acid value is too high, the cohesive force tends to decrease and hydrolysis tends to proceed easily. Also, when it is the polyester plasticizer (B') before end-capping having a carboxyl group terminal is 5 to 200 mgKOH / g, preferably 10 to 150 mgKOH / g, more ​Preferably, it is 15 to 100 mgKOH / g. If the acid value is too high, the cohesive force decreases, hydrolysis tends to proceed, and when a layer such as a metal is laminated on one surface of the adhesive layer, there is a tendency to cause corrosion. As described above, the polyester plasticizer (B') before terminal blocking usually has at least one of a carboxy group terminal and a hydroxy group terminal as a reactive molecular terminal. The polyester plasticizer (B) used in the present invention is obtained by blocking at least one of the reactive molecular terminals of the polyester plasticizer (B') before terminal blocking with a reactive molecular terminal blocking agent (b3). 〔Structural unit derived from reactive molecular terminal blocking agent (b3)〕

[0076] As described above, the polyester plasticizer (B') before terminal blocking usually has at least one of a carboxy group terminal and a hydroxy group terminal as a reactive molecular terminal. The polyester plasticizer (B) used in the present invention is obtained by blocking at least one of the reactive molecular terminals of the polyester plasticizer (B') before terminal blocking with a reactive molecular terminal blocking agent (b3). As described above, the polyester plasticizer (B') before terminal blocking usually has at least one of a carboxy group terminal and a hydroxy group terminal as a reactive molecular terminal. The polyester plasticizer (B) used in the present invention is obtained by blocking at least one of the reactive molecular terminals of the polyester plasticizer (B') before terminal blocking with a reactive molecular terminal blocking agent (b3). As described above, the polyester plasticizer (B') before terminal blocking usually has at least one of a carboxy group terminal and a hydroxy group terminal as a reactive molecular terminal. The polyester plasticizer (B) used in the present invention is obtained by blocking at least one of the reactive molecular terminals of the polyester plasticizer (B') before terminal blocking with a reactive molecular terminal blocking agent (b3). As described above, the polyester plasticizer (B') before terminal blocking usually has at least one of a carboxy group terminal and a hydroxy group terminal as a reactive molecular terminal. The polyester plasticizer (B) used in the present invention is obtained by blocking at least one of the reactive molecular terminals of the polyester plasticizer (B') before terminal blocking with a reactive molecular terminal blocking agent (b3). As described above, the polyester plasticizer (B') before terminal blocking usually has at least one of a carboxy group terminal and a hydroxy group terminal as a reactive molecular terminal. The polyester plasticizer (B) used in the present invention is obtained by blocking at least one of the reactive molecular terminals of the polyester plasticizer (B') before terminal blocking with a reactive molecular terminal blocking agent (b3).

[0077] 〔Structural unit derived from reactive molecular terminal blocking agent (b3)〕 The reactive molecular terminal blocking agent (b3) contains a functional group having reactivity with a reactive group (for example, a hydroxy group) at the terminal of the polyester plasticizer (B') before terminal blocking, and the reactive terminal of the polyester plasticizer (B') before terminal blocking reacts with the functional group of the reactive molecular terminal blocking agent (b3) to block the reactive group at the terminal. The reactive molecular terminal blocking agent (b3) contains a functional group having reactivity with a reactive group (for example, a hydroxy group) at the terminal of the polyester plasticizer (B') before terminal blocking, and the reactive terminal of the polyester plasticizer (B') before terminal blocking reacts with the functional group of the reactive molecular terminal blocking agent (b3) to block the reactive group at the terminal. The reactive molecular terminal blocking agent (b3) contains a functional group having reactivity with a reactive group (for example, a hydroxy group) at the terminal of the polyester plasticizer (B') before terminal blocking, and the reactive terminal of the polyester plasticizer (B') before terminal blocking reacts with the functional group of the reactive molecular terminal blocking agent (b3) to block the reactive group at the terminal. The reactive molecular terminal blocking agent (b3) contains a functional group having reactivity with a reactive group (for example, a hydroxy group) at the terminal of the polyester plasticizer (B') before terminal blocking, and the reactive terminal of the polyester plasticizer (B') before terminal blocking reacts with the functional group of the reactive molecular terminal blocking agent (b3) to block the reactive group at the terminal. Examples of the reactive molecular terminal blocking agent (b3) include isocyanate group-containing compounds, carbodiimide group-containing compounds, epoxy group-containing compounds, oxazoline group-containing compounds, carboxy group-containing compounds, hydroxy group-containing compounds, etc. These may be used alone or in combination of two or more. Examples of the reactive molecular terminal blocking agent (b3) include isocyanate group-containing compounds, carbodiimide group-containing compounds, epoxy group-containing compounds, oxazoline group-containing compounds, carboxy group-containing compounds, hydroxy group-containing compounds, etc. These may be used alone or in combination of two or more. Examples of the reactive molecular terminal blocking agent (b3) include isocyanate group-containing compounds, carbodiimide group-containing compounds, epoxy group-containing compounds, oxazoline group-containing compounds, carboxy group-containing compounds, hydroxy group-containing compounds, etc. These may be used alone or in combination of two or more. Examples of the reactive molecular terminal blocking agent (b3) include isocyanate group-containing compounds, carbodiimide group-containing compounds, epoxy group-containing compounds, oxazoline group-containing compounds, carboxy group-containing compounds, hydroxy group-containing compounds, etc. These may be used alone or in combination of two or more.

[0078] In the present invention, as the isocyanate group-containing compound, a monoisocyanate having one isocyanate group in the molecular structure is preferable. In the present invention, as the isocyanate group-containing compound, a monoisocyanate having one isocyanate group in the molecular structure is preferable. Examples of the monoisocyanate compound include methyl isocyanate, 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. may be used alone or in combination of two or more. Aromatic monoisocyanate compounds are preferred because of their excellent properties, and phenyl isocyanate is particularly preferred. 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 above monoglycidyl ester compound include glycidyl benzoate, glycidyl t-Bu-benzoate, glycidyl p-toluylate, cyclohe xanecarboxylic acid glycidyl ester, glycidyl pelargonate, stearic acid glycidyl ester, glycidyl laurate, glycidyl palmitate, glycidyl behenate, glycidyl versatate, glycidyl oleate, glycidyl linoleate, glycidyl linolenate, glycidyl beheno yl oleate, glycidyl stearolate, etc., and these can be used alone or in combination of two or more.

[0082] Examples of the above monoglycidyl ether compound include phenyl glycidyl ether, o-phenyl glycidyl ether, etc., and these can be used alone or in combination of two or more together.

[0083] In the present invention, as the above oxazoline group-containing compound, a monofunctional oxazoline compound having one oxazoline group in the molecular structure is preferable. Specifically, for example, 2-phenyl (2-oxazoline), 2-ethyl-2-oxazoline, etc. are mentioned, and these can be used alone or in combination of two or more.

[0084] In the present invention, as the above carboxy group-containing compound, a monocarboxylic acid having one carboxy group in the molecular structure is preferable, and particularly preferably a saturated monocarboxylic acid or the like is preferable . Examples of the monocarboxylic acid include formic acid, acetic acid, pyruvic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, 2-methylbutanoic acid, pivalic acid, hexanoic acid, 4-methylpentanoic acid, 2-ethylbutanoic acid, 2,2-dimethylbutanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, eicosanoic acid, docosanoic acid, hexacosanoic acid, triacontanoic acid and other aliphatic monocarboxylic acids, benzoic acid, toluic acid, naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, phenylacetic acid and other aromatic monocarboxylic acids. These can be used alone or in combination of two or more. Among them, aromatic monocarboxylic acids are preferred in terms of excellent reactivity and stain resistance.

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

[0086] In the present invention, as the reactive molecular terminal blocking agent (b3), in addition to the compound having one of the above functional groups, a compound having two or more functional groups can also be used within the range not impairing the effects of the present invention.

[0087] Among the above reactive molecular end-capping agents (b3), an isocyanate group-containing compound is preferred in terms of excellent reactivity with the hydroxy group end of the polyester-based plasticizer (B ’) before end-capping. .

[0088] Further, the above reactive molecular end-capping agent (b3) preferably has a number-average molecular weight of 50 to 5,000, more preferably 60 to 3,000 , particularly preferably 70 to 1,000, still more preferably 80 to 500 , and extremely preferably 90 to 300. If such a molecular weight is too small, there is a tendency for high volatility , and if it is too large, there is a tendency for the compatibility with the polyester-based resin (A) to decrease. .

[0089] The polyester-based plasticizer (B) used in the present invention preferably has at least one reactive molecular end blocked by the above reactive molecular end-capping agent (b3) from the viewpoint of excellent adhesive physical properties, and more preferably, all reactive molecular ends are blocked.

[0090] The blocking of the reactive molecular ends of the polyester-based plasticizer (B’) before end-capping with the above reactive molecular end-capping agent (b3) may be carried out by a known method. For example, in an organic solvent, the polyester-based plasticizer (B’) before end-capping may be reacted with the above reactive molecular end-capping agent (b3).

[0091] The reaction ratio between the polyester-based plasticizer (B’) before end-capping and the reactive molecular end-capping agent (b3) depends on the hydroxyl value and acid value of the polyester-based plasticizer (B’) before end-capping, that is, the carboxy groups and hydroxyl 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 0° C. Preferably, the temperature is between -70 and -3°C, more preferably between -60 and -5°C. It is more preferable that the temperature is between -55 and -10°C, and particularly preferable that the temperature is between -50 and -15°C. It is particularly preferable that the temperature is in the range of -40 to -20°C, and most preferable that the temperature is in the range of -40 to -20°C. This makes it possible to obtain a pressure-sensitive adhesive that is excellent in adhesive strength, flexibility, and tackiness. If the glass transition temperature of the polyester plasticizer (B) is too low, the cohesive strength will decrease and the adhesive strength will If the glass transition temperature is too high, flexibility is lost and tackiness decreases. However, the adhesive tends to be less effective with pressure equivalent to that of a finger. In relation to the glass transition temperature of the polyester resin (A), The glass transition temperature (TgA) of the resin (A) is equal to the glass transition temperature (TgA) of the polyester plasticizer (B). It is preferable that the temperature is lower than the temperature at which the glass transition temperature (TgB) is reached.

[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. The tackiness and compatibility with the polyester resin (A) tend to decrease. be.

[0097] Here, the heat of crystal fusion of the polyester plasticizer (B) is measured using a differential scanning calorimeter DSC Q20 manufactured by TA Instruments. It is a value measured using the differential scanning calorimeter DSC Q20 manufactured by TA Instruments. The measurement temperature range is -90 to 100 °C, the temperature increase rate is 10 °C / min, and after heating up to 10 0 °C for complete melting and then cooling down to -90 °C and heating up to 100 °C again The heat quantity of the heat of fusion during heating was taken as the heat of crystal fusion.

[0098] Also, the number average molecular weight of the polyester plasticizer (B) is 3 from the viewpoint of the cohesive force of the adhesive 00 to 12,000. Preferably it is 400 to 10,000, particularly preferably 6 00 to 8,000, more preferably 1,000 to 6,000, especially preferably 1,20 0 to 5,000, more preferably 1,500 to 4,000. By setting it within the above range, an adhesive excellent in adhesion to a low-polarity adherend, tackiness, and stain resistance can be obtained, and the compatibility with the polyester resin (A) is also improved. An adhesive excellent in adhesion to a low-polarity adherend, tackiness, and stain resistance can be obtained, and the compatibility with the polyester resin (A) is also improved. If such a number average molecular weight is too small, sufficient cohesive force cannot be obtained as an adhesive when using the polyester plasticizer (B) as a plasticizer, and the adhesion and stain resistance tend to decrease. There is a tendency. Also, if the number average molecular weight is too large, the compatibility with the polyester resin (A) tends to decrease. There is a tendency. There is a tendency. The number average molecular weight can be measured by the same method as the weight average molecular weight of the polyester resin described for the polyester resin (A). The number average molecular weight can be measured by the same method as the weight average molecular weight of the polyester resin described for the polyester resin (A).

[0099] Also, the weight average molecular weight of the polyester plasticizer (B) is 1000 to 12,000 from the viewpoint of the cohesive force of the adhesive. Preferably it is 1,200 to 10,000, particularly preferably 1,500 to 8,000, more preferably 2,000 to 7,500, especially preferably is 2,500 to 7,000, more preferably 3,000 to 6,500. By setting it within the above range, an adhesive excellent in adhesion to a low-polarity adherend and stain resistance can be obtained, and the compatibility with the polyester resin (A) is also improved. If such a weight-average molecular weight is too small, when the polyester plasticizer (B) is used as a plasticizer, sufficient cohesive force cannot be obtained as an adhesive, and the adhesion and stain resistance tend to decrease. Also, if the weight-average molecular weight is too large, the compatibility with the polyester resin (A) tends to decrease. The weight-average molecular weight can be measured by the same method as the weight-average molecular weight of the polyester resin described for the polyester resin (A).

[0100] The hydroxyl value of the above polyester resin (B) is preferably 15 mgKOH / g or less, more preferably 10 mgKOH / g or less, even more preferably 8 mgKOH / g or less, particularly preferably 5 mgKOH / g or less, especially preferably 3 mgKOH / g or less, and most preferably 1 mgKOH / g or less. The lower limit is 0 mgKOH / g. If the hydroxyl value is too high, it tends to crosslink with the polyester resin (A), and the adhesion and tackiness tend to decrease.

[0101] The acid value of the above polyester resin (B) is preferably 10 mgKOH / g or less, more preferably 5 mgKOH / g or less, even more preferably 3 mgKOH / g or less, particularly preferably 1 mgKOH / g or less, especially preferably 0.5 mgK OH / g or less. The lower limit is 0 mgKOH / g. By setting it within the above range, an adhesive excellent in adhesive strength and tackiness can be obtained, and hydrolysis of the polyester-based plasticizer (B) can be suppressed. If the acid value is too high, it will crosslink with the polyester resin (A), resulting in a decrease in adhesive strength and tackiness, or a decrease in hydrolysis resistance. The total of the acid value and hydroxyl value of the above polyester-based plasticizer (B) is preferably 20 mgKOH / g or less, more preferably 15 mgKOH / g or less, even more preferably 10 mgKOH / g or less, particularly preferably 5 mgKOH / g or less, extremely preferably 3 mgKOH / g or less, and most preferably 1 mgKOH / g or less. The lower limit is 0 mgKOH / g. If the total of the acid value and hydroxyl value is too high, it will crosslink with the polyester-based (A), resulting in a tendency for the adhesive strength and tackiness to decrease, or the hydrolysis resistance to decrease. (A) and the adhesive strength and tackiness decrease, or the hydrolysis resistance decreases. There is a tendency.

[0102] The content of the above polyester-based plasticizer (B) is preferably 0.1 to 150 parts by weight, more preferably 1 to 140 parts by weight, even more preferably 3 to 130 parts by weight, particularly preferably 5 to 120 parts by weight, more preferably 10 to 100 parts by weight, even more preferably 15 to 90 parts by weight, particularly preferably 20 to 80 parts by weight, extremely preferably 30 to 70 parts by weight, and most preferably 40 to 60 parts by weight with respect to 100 parts by weight of the polyester resin (A). By setting it within the above range, an adhesive excellent in stain resistance, adhesive strength, and tackiness can be obtained. If the content of the polyester-based plasticizer (B) is too large, the cohesive force will decrease and the stain resistance will tend to decrease. It is more preferably 15 mgKOH / g or less, even more preferably 10 mgKOH / g or less, particularly preferably 5 mgKOH / g or less, extremely preferably 3 mgKOH / g or less, and most preferably 1 mgKOH / g or less. The lower limit is 0 mgKOH / g. If the total of the acid value and hydroxyl value is too high, it will crosslink with the polyester-based (A), resulting in a tendency for the adhesive strength and tackiness to decrease, or the hydrolysis resistance to decrease. It is even more preferably 10 mgKOH / g or less, particularly preferably 5 mgKOH / g or less, extremely preferably 3 mgKOH / g or less, and most preferably 1 mgKOH / g or less. The lower limit is 0 mgKOH / g. If the total of the acid value and hydroxyl value is too high, it will crosslink with the polyester-based (A), resulting in a tendency for the adhesive strength and tackiness to decrease, or the hydrolysis resistance to decrease. It is extremely preferably 3 mgKOH / g or less, and most preferably 1 mgKOH / g or less. The lower limit is 0 mgKOH / g. If the total of the acid value and hydroxyl value is too high, it will crosslink with the polyester-based (A), resulting in a tendency for the adhesive strength and tackiness to decrease, or the hydrolysis resistance to decrease. The lower limit is 0 mgKOH / g. If the total of the acid value and hydroxyl value is too high, it will crosslink with the polyester-based (A), resulting in a tendency for the adhesive strength and tackiness to decrease, or the hydrolysis resistance to decrease. It will crosslink with the polyester-based (A), resulting in a tendency for the adhesive strength and tackiness to decrease, or the hydrolysis resistance to decrease. There is a tendency.

[0103] The content of the above polyester-based plasticizer (B) is preferably 0.1 to 150 parts by weight with respect to 100 parts by weight of the polyester resin (A). More preferably, it is 1 to 140 parts by weight. Even more preferably, it is 3 to 130 parts by weight. Particularly preferably, it is 5 to 120 parts by weight. More preferably, it is 10 to 100 parts by weight. Even more preferably, it is 15 to 90 parts by weight. By setting it within the above range, an adhesive excellent in stain resistance, adhesive strength, and tackiness can be obtained. If the content of the polyester-based plasticizer (B) is too large, the cohesive force will decrease and the stain resistance will tend to decrease. If the content of the polyester-based plasticizer (B) is too large, the cohesive force will decrease and the stain resistance will tend to decrease. There is [a certain component], and if its content is too small, the adhesive force and tackiness tend to decrease.

[0104] Also, the content of the polyester plasticizer (B) is preferably 0.1 to 75% by weight, more preferably 1 to 60% by weight, still more preferably 5 to 55% by weight, particularly preferably 10 to 50% by weight, especially preferably 20 to 45% by weight, and most preferably 25 to 40% by weight, based on 10 0% by weight of the adhesive composition (active ingredient amount). If the content of the polyester plasticizer (B) is too large, the cohesive force tends to decrease and the stain resistance tends to decrease. If the content is too small, the adhesive force and tackiness tend to decrease.

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

[0106] As the above hydrolysis inhibitor (C), conventionally known ones can be used. For example, compounds that react and bond with the carboxyl group terminals of the polyester resin (A) can be mentioned. Specifically, for example, compounds containing functional groups such as carbodiimide groups, epoxy groups, oxazoline groups, etc. can be mentioned. The above hydrolysis inhibitor (C) can be used alone or in combination of two or more. Among them, carbodiimide group-containing compounds are preferable in that they have a high effect of eliminating the catalytic activity of protons derived from carboxylic acid terminal groups.

[0107] As the above carbodiimide group-containing compound, usually, a compound having a carbodiimide group (-N = C = N- ​​​​​​​Known carbodiimide compounds having one or more in the molecule include, among others, compounds containing two or more carbodiimide groups in the molecule, that is, polyvalent carbodiimide compounds are preferred, and particularly compounds containing three or more, more preferably five or more, especially seven or more carbodiimide groups in the molecule are preferred. Note that the number of carbodiimide groups contained in the above polyvalent carbodiimide compounds is usually 50 or less. If there are too many carbodiimide groups, the molecular structure becomes too large, resulting in a decrease in compatibility with the polyester resin (A), which is not preferable.

[0108] In addition, as the above carbodiimide group-containing compound, high molecular weight polycarbodiimide produced by decarboxylation condensation reaction of diisocyanate in the presence of a carbodiimidization catalyst is also preferably used.

[0109] Such high molecular weight polycarbodiimide may be synthesized or a commercially available product may be used. When synthesizing high molecular weight polycarbodiimide, for example, those obtained by decarboxylation condensation reaction of the following diisocyanates can be mentioned.

[0110] Examples of such diisocyanates include 4,4'-diphenylmethane diisocyanate, 3,3'-dimethoxy-4,4'-diphenylmethane diisocyanate, 3,3' -dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-diphenylethane 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 etc. may be mentioned, and these may be used alone or in combination of two or more kinds.

[0111] Furthermore, it is preferable in terms of storage stability that the high molecular weight polycarbodiimide has its terminal isocyanate group blocked by a blocking agent. Examples of the blocking agent include compounds having active hydrogen that reacts with the isocyanate group, or compounds having an isocyanate group. For example, monoalcohols, monocarboxylic acids, monoamines, and monoisocyanates having one substituent selected from a carboxy group, an amino group, and an isocyanate group may be mentioned.

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

[0113] In addition, a commercially available product may be used as the above carbodiimide group-containing compound. Examples of commercially available products of carbodiimide group-containing compounds include, for example, the Carbodilite (registered trademark ) series manufactured by Nisshinbo Chemical Inc. Among them, Carbodilite (registered trademark) "V-01", "V-02B", "V-03", "V-04K", "V-04PF", "V-05", " V-07", "V-09", "V-09GB" are preferable in terms of excellent compatibility with the polyester resin (A).

[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 propoxy)benzene, 1-(β,γ-epoxypropoxy)-2-ethoxyethane, 1- (β,γ-epoxypropoxy)-2-benzyloxyethane, 2,2-bis-[р-( β,γ-epoxypropoxy)phenyl]propane, and bisphenols such as 2,2-bis-(4-hydro xyphenyl)propane and 2,2-bis-(4-hydroxyphenyl)methane, and bisglycidyl polyethers obtained by the reaction of epichlorohydrin with bisphenols, etc. are mentioned, and these can be used alone or in combination of two or more. Examples include those obtained by the reaction of bisphenols with epichlorohydrin, and these can be used alone or in combination of two or more. These can be used alone or in combination of two or more.

[0116] As the oxazoline group-containing compound, bisoxazoline compounds and the like are preferable. 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'-bis(4-butyl-2-oxazoline) ), 2,2'-bis(4-hexyl-2-oxazoline), 2,2'-bis(4-phenyl-2-oxazoline), 2,2'-bis(4-cycl ohexyl-2-oxazoline), 2,2'-bis(4-benzyl-2-oxazoline) ), 2,2'-p-phenylene bis(2-oxazoline), 2,2'-m-phenylene bis (2-oxazoline), 2,2'-o-phenylene bis(2-oxazoline), 2,2' (4-methyl-2-oxazoline), 2,2'-p-phenylene bis(4-methyl-2-oxazoline), 2,2'-p-phenylene bis (4-methyl-2-oxazoline), 2,2'-p-phenylene bis 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, It is more preferably 3,000 to 15,000, and more preferably 4,000 to 10,000. It is particularly preferred that 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 compatibility with the polyester resin (A) is poor, which tends to cause turbidity. If the amount is too small, it tends to be difficult to obtain sufficient durability.

[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. There is a tendency for the adhesive strength, cohesion and durability 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 tackiness and mechanical properties. Polyisocyanate compounds are particularly preferred because they offer a good balance of 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. It is preferably contained with the crosslinking agent (D) at a ratio of 0 to 10 equivalents, particularly preferably 0.5 ~5 equivalents, more preferably 0.5 to 3 equivalents. If the number of equivalents of the reactive group contained in such a crosslinking agent (D) is too small, the cohesive force tends to decrease and if it is too large, the flexibility tends to decrease.

[0123] Also, the content of the crosslinking agent (D) is based on 100 parts by weight of the polyester resin (A) It is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 15 parts by weight particularly preferably 1 to 10 parts by weight, even more preferably 1.5 to 8 parts by weight and most preferably 2 to 6 parts by weight. If the content of the crosslinking agent (D) is too large, the tackiness tends to decrease and if the content is too small, the stain resistance tends to decrease.

[0124] In the reaction between the polyester resin (A) and the crosslinking agent (D), these polyester resin (A), and an organic solvent having no functional group that reacts with the crosslinking agent (D) component, for example , esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone and aromatic compounds such as toluene and xylene can be used as the organic solvent. These can be used alone or in combination of two or more.

[0125] <Urethane-forming catalyst (E)> The pressure-sensitive adhesive composition of the present invention preferably further contains a urethane-forming catalyst (E). As the urethane-forming catalyst (E), for example, an organometallic compound, a tertiary amine compound, etc can be used. These can be used alone or in combination of two or more.

[0126] Examples of the above organometallic compounds include zirconium compounds, iron compounds, tin compounds, titanium compounds, lead compounds, cobalt compounds, zinc compounds, and the like. Examples of the zirconium compounds include zirconium naphthenate, zirconium acetylacetonate, and the like. Examples of the iron compounds include iron acetylacetonate, iron 2-ethylhexanoate, and the like. Examples of the tin compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dilaurate, and the like. Examples of the titanium compounds include dibutyltitanium dichloride, tetrabutyl titanate, butoxytitanium trichloride, and the like. Examples of the lead compounds include lead oleate, lead 2-ethylhexanoate, lead benzoate, lead naphthenate, and the like. Examples of the cobalt compounds include cobalt 2-ethylhexanoate, cobalt benzoate, and the like. Examples of the zinc compounds include zinc naphthenate, zinc 2-ethylhexanoate, and the like. Examples of the tertiary amine compounds include triethylamine, triethylenediamine, 1,8-diazabicyclo-(5,4,0)-undecene-7, and the like.

[0127] Among these urethanization catalysts (E), organometallic compounds are preferred in terms of reaction rate and pot life of the adhesive layer, particularly preferably zirconium compounds, and especially preferably zirconium acetylacetonate.

[0128]

[0129] [[Inhibitor for catalytic action]]​​​​​​​​​​​​ 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 the plasticizer (B), hydrolysis inhibitor (C), crosslinking agent (D), urethanization catalyst (E), etc., in the range that does not impair the effects of the present invention, antioxidants such as hindered phenols, softening agents, ultraviolet absorbers, silane coupling agents, stabilizers, antistatic agents, tackifiers, etc. additives and other inorganic or organic fillers, powders such as metal powders and pigments, particulate additives, etc. can be blended. These can be used alone or in combination of two or more.

[0132] The above-mentioned tackifier is not particularly limited, and conventionally known ones can be used. For example, terpene-based tackifiers, phenol-based tackifiers, rosin-based tackifiers, petroleum-based tackifiers, xylene-based tackifiers, epoxy-based tackifiers, polyamide-based tackifiers, ketone-based tackifiers, elastomer-based tackifiers, etc. can be mentioned. Among them, in terms of excellent tack and adhesive strength, it is preferable to use petroleum-based tackifying resins or terpene-based tackifiers. Particularly, styrene-based tackifiers and terpene phenol-based tackifying resins are preferable. These can be used alone or in combination of two or more.

[0133] When blending the above-mentioned tackifier, it is preferably 0.01 to 50 parts by weight, more preferably 0.1 to 30 parts by weight, even more preferably 1 to 20 parts by weight, and particularly preferably 3 to 10 parts by weight, based on 100 parts by weight of the polyester resin (A). This is preferable in terms of excellent tack. [[ID=···]]

[0134] [[ID=···]] Also, the adhesive composition of the present invention may contain a small amount of impurities contained in the raw materials for producing the components of the adhesive composition, etc., in addition to the above-mentioned additives.

[0135] ​​​Such an adhesive composition can be obtained, for example, by preparing the above polyester resin (A), polyester-based plasticizer (B) and necessary optional components, etc., and blending and dispersing them during the production of the polyester resin (A), or by blending them into a solution of the polyester resin (A) dissolved in an organic solvent and dispersing them using a mixing roller, etc.

[0136] Further, the adhesive according to the present invention is composed of the above adhesive composition, that is, the adhesive composition is crosslinked (cured).

[0137] And the adhesive sheet of the present invention has an adhesive layer containing the above adhesive. The above adhesive sheet may be an adhesive sheet having an adhesive layer on one or both sides of a support substrate, or a substrate-less type substrate-less double-sided adhesive sheet having no substrate. And the adhesive sheet of the present invention is particularly suitable as an adhesive sheet for electronic members used for bonding electronic members. In the present invention, "sheet" means including "film" and "tape".

[0138] <Adhesive sheet> The above adhesive sheet can be produced, for example, as follows. As a method for producing such an adhesive sheet, it can be produced according to a known general method for producing an adhesive sheet. For example, the above adhesive composition is applied and dried on one surface of a substrate to form an adhesive layer, and a release sheet is bonded to the surface (the opposite surface to the surface in contact with the substrate), and if necessary, cured to obtain an adhesive sheet of the present invention having a substrate and an adhesive layer, and the above adhesive layer is provided on at least one surface of the above substrate.

[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, poly olefin fiber and the like can be mentioned. Examples of the rubber sheet include a natural rubber sheet, a butyl rubber sheet, and the like. . Examples of the foam sheet include a foamed polyurethane sheet, a foamed polyacrylic sheet, a foamed polyolefin sheet, and the like. Examples of the metal foil include an aluminum foil, a copper foil, and the like. These base materials can be used as a single layer or as a multilayer in which two or more kinds are laminated. It is possible.

[0143] Among these, in particular, a base material made of polyethylene terephthalate, polyimide, foamed polyurethane sheet, foamed polyacrylic sheet, or foamed polyolefin sheet is preferred, and polyethylene terephthalate is particularly preferred in terms of excellent adhesiveness to the adhesive. The base material is preferred because it has excellent adhesive strength with the adhesive and can significantly exhibit the effect of the adhesive used in the present invention. In terms of preferred.

[0144] Examples of the release sheet include those obtained by subjecting various resin films, papers, cloths, rubber sheets, foam sheets, metal foils, and composites thereof exemplified as the base material to a release treatment. Among them, it is preferable to use a silicone-based release sheet as the release sheet. It is possible. preferred.

[0145] When a resin film is used as the base material, the thickness of the resin film base material is not particularly limited. From the viewpoint of avoiding the adhesive sheet from becoming excessively thick, the thickness of the base film is, for example , 200 μm or less, preferably 150 μm or less, more preferably 100 μm or less. to 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 set to 5% by weight or more in terms of adhesive strength and tackiness. It is particularly preferable that the content is 10 to 80% by weight, and further preferably 15 to 60% by weight. The gel fraction is particularly preferably 20 to 50% by weight, and most preferably 25 to 45% by weight. If the gel fraction is too low, the stain resistance tends to decrease. If the gel fraction is too high, the adhesive strength and tackiness tend to decrease. There is a tendency for sexual activity 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. All values are by weight unless otherwise specified. 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 of the polyols. 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. Polycarboxylic acids (a1) include 96 parts of isophthalic acid (IPA; a1-1), sebacic acid (SebA; a1-2) 468 parts, neopentyl glycol ( NPG (a2-2) 271 parts, 1,4 butanediol (1,4BG; a2-1) 130 parts , 1,6-hexanediol (1,6HG; a2-1) 30 parts, trimethylolpropane (TMP; a2-3) 5 parts, zinc acetate 0.05 parts as a catalyst were charged, and the internal temperature (liquid temperature) was 25 The temperature was raised to 0°C, and the esterification reaction was carried out for 4 hours. Thereafter, the internal temperature was further increased to 260°C, and 0.05 parts of tetrabutyl titanate was added as a catalyst. The pressure was reduced to 1.33 hPa, and polycondensation reaction was carried out for 3 hours. A polyester resin (A-1) was obtained. The glass transition temperature (Tg) of the obtained polyester resin (A-1) was -48°C, the number average molecular weight was 16,000, and the weight average molecular weight (Mw) was 86,000. Other various properties were as shown in Table 1 below. Also, the final component ratio was isophthalic acid / sebacic acid = 20 mol% / 80 mol% as polycarboxylic acids (a1), and neopentyl glycol / 1 ,4-butanediol / 1,6-hexanediol / trimethylolpropane = 58.5 mol % / 34 mol% / 6.2 mol% / 1.3 mol% as polyol (a2).

[0160]

Table 1

[0161] [Polyester plasticizer (B-1)] [Production of polyester plasticizer (B'-1) before end-capping] Into a reaction vessel equipped with a heating device, a thermometer, a stirrer, a rectification column, a nitrogen inlet tube, and a vacuum device, as polycarboxylic acids (b1) as shown in Table 2 below, 290 parts of isophthalic acid (IPA; b1 -1), 255 parts of adipic acid (AdA; b1-2), and polyol (b2) 454 parts of 3-methylpentanediol (MPD; b2-2) were charged as, and 0.05 part of tetrabutyl titanate was charged as a catalyst. The temperature was raised to 250°C, and an esterification reaction was carried out over 4 hours. After that, the internal temperature was raised to 260°C and the pressure was reduced to 100 hPa, and an esterification reaction was carried out over 1 hour to obtain a polyester plasticizer (B'-1) before end-capping. The final component ratio of the obtained polyester plasticizer (B'-1) before end-capping was polycarboxylic acids (a1) and ​​ to obtain isophthalic acid / adipic acid = 50 / 50 mol%, and 3-methyl-1,5-pentanediol = 100 mol% as the polyol (a2). The acid value was 0.1 mgKOH / g, and the hydroxyl value was 56.0 mgKOH / g. The physical properties and the like of the obtained polyester plasticizer (B'-1) before end-capping are shown in Table 2 below.

[0162] [Production of Polyester Plasticizer (B-1)] To 100 parts of the above polyester plasticizer (B'-1) before end-capping, 40 parts of ethyl acetate and 11.8 parts of phenyl isocyanate as a capping agent were charged, and the mixture was reacted at an internal temperature of 60 °C for 4 hours to obtain a polyester plasticizer (B-1) with reactive molecular terminals capped. The acid value of the obtained polyester plasticizer (B-1) was 0.1 mgKOH / g, and the hydroxyl value was 0.6 mgKOH / g. The obtained polyester plasticizer (B-1) did not show a peak in the crystal melting heat (J / g) and had no melting point.

[0163] The physical properties and the like of the obtained polyester plasticizer (B-1) with reactive molecular terminals capped are shown in Table 3 below.

[0164]

Table 2

[0165]

Table 3

[0166] Next, as the hydrolysis inhibitor (C), crosslinking agent (D), and urethanization catalyst (E), the following were prepared.

[0167] [Hydrolysis inhibitor (C)] (C-1): Polycarbodiimide compound (manufactured by Nisshinbo Chemical Inc., "Carbodilite V-0" 9GB"; number average molecular weight 3,700; weight average molecular weight 9,200; (Y) / (X)= 28.0)

[0168] [Crosslinking agent (D)] (D-1): Trimethylolpropane / tolylene diisocyanate adduct (manufactured by Tosoh Corporation, "Coronate L55E")[[]END]]

[0169] [Urethane catalyst (E)] (E-1): Zirconium-based compound diluted to a solid content concentration of 1% with acetylacetone (manufactured by Matsumoto Fine Chemical Co., Ltd., "Organix ZC-150")[[]END]] (E-1): Zirconium-based compound diluted to a solid content concentration of 1% with acetylacetone (manufactured by Matsumoto Fine Chemical Co., Ltd., "Organix ZC-150")[[]END]]

[0170] (Example 1) The polyester resin (A-1) obtained above was diluted with ethyl acetate to a solid content concentration of 50% and, based on 100 parts (solid content) of this polyester resin (A-1) solution, 10 parts of polyester-based plasticizer (B-1), 1 part (solid content) of hydrolysis inhibitor (C-1), crosslinking agent (D-1) 1.7 parts (solid content), and 0.02 part (solid content) of urethane catalyst (E-1) were blended and stirred and mixed to obtain a polyester-based pressure-sensitive adhesive composition.

[0171] (Example 2) In Example 1, a polyester-based pressure-sensitive adhesive composition was obtained in the same manner as in Example 1, except that the blending amount of the polyester-based plasticizer (B-1) was changed to 30 parts and the blending amount of the crosslinking agent (D- 1) was changed to 2 parts.

[0172] (Example 3) In Example 1, a polyester-based pressure-sensitive adhesive composition was obtained in the same manner as in Example 1, except that the blending amount of the polyester-based plasticizer (B-1) was changed to 50 parts and the blending amount of the crosslinking agent (D- ​The polyester adhesive was prepared in the same manner as in Example 1, except that the blending amount of 1) was changed to 2.5 parts. A composition was obtained.

[0173] Example 4 In Example 1, the blending amount of the polyester plasticizer (B-1) was 100 parts, the crosslinking agent ( The polyester adhesive was prepared in the same manner as in Example 1, except that the blending amount of D-1) was changed to 4 parts. A composition was obtained.

[0174] . (Comparative Example 1) In Example 1, the polyester plasticizer (B-1) was not added, and the crosslinking agent (D-1) was added. A polyester-based pressure-sensitive adhesive composition was prepared in the same manner as in Example 1, except that the blending amount was changed to 1.3 parts. obtained.

[0175] Using the polyester-based pressure-sensitive adhesive compositions obtained in Examples 1 to 4 and Comparative Example 1, Pressure-sensitive adhesive sheets were prepared as follows and various evaluations were carried out.

[0176] <Preparation of adhesive sheet with one-sided release film> The polyester-based pressure-sensitive adhesive compositions obtained in Examples 1 to 4 and Comparative Example 1 were applied to a 38 μm thick film. was applied to a PET film (Toray Industries, Inc., "Lumirror T60") using an applicator. Thereafter, it was dried at 100°C for 3 minutes to obtain a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive composition layer thickness of 25 µm. Next, the surface of the adhesive layer of the obtained adhesive sheet was covered with a 38 μm-thick PET release film ( After covering the sample with a sheet of paper (Mitsui Chemicals Tocello Co., Ltd., "SP-PET-01-BU"), the sample was left at 40°C for 4 days. A jig treatment was carried out to obtain a pressure-sensitive adhesive sheet with a release film on one side.

[0177] [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, wrapped with a 200-mesh SUS wire mesh, and immersed in toluene at 2 3°C for 24 hours. The weight of the adhesive component before immersion and the weight of the insoluble adhesive component remaining in the wire mesh after immersion were measured, and the percentage was calculated according to the following formula and taken as the gel fraction (%). However, the weight of the substrate was subtracted. . Weight of the insoluble adhesive component remaining in the wire mesh after immersion / Weight of the adhesive component before immersion × 1 00 (%)

[0178] (Adhesive sheet evaluation) [Adhesion force] The adhesive sheet with the single-sided release film obtained above was cut into a size of 23°C, 50% RH environment and 2 5 mm × 200 mm. After peeling off the release film, the adhesive layer side was pressed and attached to (1 ) mirror-finished stainless steel plate (SUS-BA plate), (2) polypropylene plate (PP), ( 3) polyethylene plate (PE) with a 2 kg roller reciprocated, allowed to stand for 30 minutes in the same atmosphere, and then the 180-degree peel adhesion force (N / 25 mm) was measured at a peel rate of 300 mm / min using an autograph (manufactured by Shimadzu Corporation, "Autograph AG-X 50N" ). The evaluation criteria are as follows. The measurement was carried out. (Evaluation criteria) ◎ ··· Greater than 5 N / 25 mm and the peeling state was adherend interface peeling 〇 ··· Greater than 3 N / 25 mm and less than or equal to 5 N / 25 mm, and the peeling state was adherend interface peeling △ ··· Greater than 1 N / 25 mm and less than or equal to 3 N / 25 mm, and the peeling state was adherend interface peeling × ··· Less than or equal to 1 N / 25 mm, or the peeling state was cohesive peeling or adherend substrate interface peeling

[0179] [Stain resistance]​ The pressure-sensitive adhesive sheet with a single-sided release film obtained above was cut into a size of 23°C, 50%RH environment at 2 After cutting into a size of 5 mm × 200 mm, the release film was peeled off, and the pressure-sensitive adhesive layer side was polished The surface finish stainless steel plate (SUS-BA plate) was pressure-bonded by reciprocating a 2 kg roller, and the same atmosphere After curing for 30 minutes in the atmosphere and making it a measurement sample, an autograph (manufactured by Shimadzu Corporation, " Autograph AG-X 50N") was used to peel off at a peeling speed of 300 mm / min at 180 degrees The presence or absence of adhesive residue on the mirror-finished stainless steel plate as the adherend was visually confirmed. The evaluation criteria are as follows. (Evaluation criteria) ◎ ··· No residue was confirmed × ··· Residue was confirmed

[0180] [Tackiness] The pressure-sensitive adhesive sheet with a single-sided release film obtained above was cut into a size of 23°C, 50%RH environment at 1 After cutting into a size of 2 mm × 12 mm, the release film was peeled off, and probe tack (test Manufactured by TA Industries Co., Ltd., TE-6001) was used with a probe diameter of 5 mmΦ, a pushing speed of 10 mm / sec, a pulling speed of 10 mm / sec, a pressing time of 5 seconds, and a sticking pressure of 1000 gf / cm 2 The probe tack was measured. The evaluation criteria are as follows. (Evaluation criteria) ◎ ··· 5 N or more 〇 ··· 4 N or more and less than 5 N △ ··· 3 N or more and less than 4 N × ··· Less than 3 N

[0181]

Table 4

[0182] From the results in Table 4 above, the pressure-sensitive adhesive sheets obtained from the pressure-sensitive adhesive compositions of Examples 1 to 4 have an adhesive force and are found to be excellent in both stain resistance and tackiness when peeling from the adherend. On the other hand, the pressure-sensitive adhesive sheet obtained from the pressure-sensitive adhesive composition of Comparative Example 1 that does not contain the polyester plasticizer (B) is excellent in stain resistance when peeling from the adherend, but is inferior in adhesive force and tackiness to PE, which is a low-polarity adherend. That is, it was inferior. From the above, it can be seen that the polyester-based pressure-sensitive adhesive composition containing a polyester plasticizer is excellently balanced in the adhesive properties when used as a pressure-sensitive adhesive. That is, it is excellent.

Industrial Applicability

[0183] The pressure-sensitive adhesive composition of the present invention is excellent in adhesive force, stain resistance, and tackiness, and therefore, the pressure-sensitive adhesive and pressure-sensitive adhesive sheet using the same can be suitably used for applications such as bonding of electronic members and label applications. That is, it can be suitably used.

Claims

1. A polyester-based pressure-sensitive adhesive composition containing a polyester-based resin (A) having structural units derived from polyvalent carboxylic acids (a1) and structural units derived from polyols (a2), and a polyester-based plasticizer (B), wherein the polyester-based plasticizer (B) has structural units derived from polyvalent carboxylic acids (b1), structural units derived from polyols (b2), and structural units derived from a reactive molecular terminal blocking agent (b3).

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. The polyester-based pressure-sensitive adhesive composition according to Claim 1 or 2, wherein the glass transition temperature (TgA) of the polyester-based resin (A) is -80 to -25°C.

4. The polyester-based pressure-sensitive adhesive composition according to any one of Claims 1 to 3, wherein the acid value of the polyester-based resin (A) is 5 mgKOH / g or less.

5. The polyester-based pressure-sensitive adhesive composition according to any one of Claims 1 to 4, wherein the weight average molecular weight of the polyester-based plasticizer (B) is 1,000 to 12,000.

6. The polyester-based pressure-sensitive adhesive composition according to any one of Claims 1 to 5, wherein the content of the polyester-based plasticizer (B) is 0.1 to 150 parts by weight with respect to 100 parts by weight of the polyester-based resin (A).

7. The polyester-based pressure-sensitive adhesive composition according to any one of Claims 1 to 6, wherein the acid value of the polyester-based plasticizer (B) is 5 mgKOH / g or less.

8. The polyester-based pressure-sensitive adhesive composition according to any one of Claims 1 to 7, wherein the glass transition temperature (TgB) of the polyester-based plasticizer (B) is -80 to 0°C.

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

10. The polyester-based pressure-sensitive adhesive composition according to any one of Claims 1 to 9, which contains a hydrolysis inhibitor (C).

11. The polyester-based pressure-sensitive adhesive composition according to any one of Claims 1 to 10, which contains a crosslinking agent (D).

12. A polyester-based pressure-sensitive adhesive, characterized in that the polyester-based pressure-sensitive adhesive composition according to any one of Claims 1 to 11 is crosslinked.

13. An adhesive sheet, characterized by having an adhesive layer containing the polyester-based pressure-sensitive adhesive according to Claim 12.

14. An adhesive sheet having an adhesive layer obtained from the polyester-based pressure-sensitive adhesive according to Claim 12 and a base material, wherein the adhesive layer is provided on at least one side of the base material.

15. An adhesive sheet having an adhesive layer obtained from the polyester-based pressure-sensitive adhesive according to Claim 12, which is a type without a base material, characterized by not having a base material.

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