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

Abstract

To provide an adhesive composition excellent in adhesive force to various adherends and excellent in holding power and tackiness.SOLUTION: A polyester-based adhesive composition contains: a polyester-based resin (A) having a structural unit derived from a polycarboxylic acid (a1) and a structural unit derived from a polyol (a2); and a petroleum resin-based tackifier (B) having a number average molecular weight of 400-8,000. The content of the petroleum resin-based tackifier (B) having a number average molecular weight of 400-8,000 is 0.01-50 pts.wt. based on 100 pts.wt. of the polyester-based resin (A).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a polyester-based pressure-sensitive adhesive composition, a polyester-based pressure-sensitive adhesive, and a pressure-sensitive adhesive sheet. More specifically, the present invention relates to a polyester-based pressure-sensitive adhesive composition, a polyester-based pressure-sensitive adhesive, and a pressure-sensitive adhesive sheet that are excellent in adhesive force to various adherends and further excellent in holding power and tackiness.

Background Art

[0002] Conventionally, it is known that a polyester 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 adhesives (pressure-sensitive adhesives).

[0003] In recent years, with the miniaturization and thinning of parts and members, a high adhesive force is required even for a small area of the pressure-sensitive adhesive. As a method for improving the adhesive force, for example, Patent Document 1 proposes a polyester-based pressure-sensitive adhesive composition containing a polyester and an adhesion promoter. Furthermore, Patent Document 2 proposes a polyester-based pressure-sensitive adhesive composition containing a polyester, a hydrolysis-resistant agent, an adhesion promoter, and a crosslinking agent, and containing 20 to 100 parts by weight of an adhesion promoter having a specific acid value and a specific softening point with respect to 100 parts by weight of the polyester.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

[0005] However, the techniques disclosed in Patent Documents 1 and 2 do not include rosin esters or terpene. It contains a tackifier with a high softening point such as propylene resin. Generally, it is used to give cohesive strength at high temperatures. For this reason, it is common to add a tackifier with a high softening point. Problems remain such as a decrease in tackiness at room temperature, yellowing, clouding, and other changes in appearance. there were. In addition, the terpene resin-based tackifiers described in Patent Documents 1 and 2 have low polarity. However, there was also a concern about compatibility with polyester resins.

[0006] In view of the above, the present invention provides a method for producing a cellulose acylate having excellent adhesion to various adherends and Another object of the present invention is to provide a polyester-based pressure-sensitive adhesive composition having excellent holding power and tackiness. The present invention also aims to provide a polyester-based adhesive and an adhesive sheet. Let us assume that. [Means for solving the problem]

[0007] However, the present inventors have conducted extensive research in light of the above circumstances and have found that polyester resins In the polyester-based pressure-sensitive adhesive composition, By using a petroleum resin-based tackifier having a number average molecular weight of A polyester adhesive with excellent adhesion to various substrates, as well as excellent holding power and tackiness. The present invention has been accomplished by finding that an adhesive composition can be obtained.

[0008] That is, the present invention relates to a polyester resin (A) having a structural unit derived from polycarboxylic acids (a1) and a structural unit derived from polyol (a 2), and a petroleum resin-based tackifier (B) having a number average molecular weight of 400 to 8 000, wherein the content of the petroleum resin-based tackifier (B) having a number average molecular weight of 400 to 8000 is 0.01 to 50 parts by weight with respect to 100 parts by weight of the polyester resin (A). This is the first gist of the polyester-based pressure-sensitive adhesive composition.

[0009] Further, the present invention has a second gist of a polyester-based pressure-sensitive adhesive obtained by crosslinking the above polyester-based pressure-sensitive adhesive composition, and a pressure-sensitive adhesive layer containing the above polyester-based pressure-sensitive adhesive. The third gist is a pressure-sensitive adhesive sheet having

[0010] In a polyester-based pressure-sensitive adhesive, generally, a tackifier is blended to improve the adhesive force to an adherend. In this case, conventionally known tackifiers such as terpene resins, phenol resins, rosin resins, aliphatic petroleum resins, aromatic petroleum resins, copolymerized petroleum resins, alicyclic petroleum resins, xylene resins, epoxy resins, polyamide resins, ketone resins, elastomer resins, etc. can be used. Usually, terpene resins and rosin resins are often used from the viewpoints of adhesive strength and tackiness. However, there are problems such as poor compatibility with polyester resins and hydrolysis due to high acid values. Also, since petroleum resins have low polarity, they are considered not to be practically used because of their poor compatibility with highly polar polyester resins and the decrease in tackiness. However, in the present invention, when a polyester resin is used as a base resin, a petroleum resin-based tackifier having a number average molecular weight of 400 to 8000 is deliberately added to the polyester resin. ​​​​​When a petroleum resin-based tackifier is blended, unexpectedly, the adhesive strength and tackiness may decrease Instead, it has excellent adhesive strength, holding power, and tackiness, and has achieved the object of the present invention It is what has come.

Effect of the Invention

[0011] The polyester-based pressure-sensitive adhesive composition of the present invention comprises a polyester-based resin (A) having structural units derived from polycarboxylic acids (a1) and structural units derived from polyols (a2), and a petroleum resin-based tackifier (B) having a number-average molecular weight of 400 to 8000. The content of the petroleum resin-based tackifier (B) having a number-average molecular weight of 400 to 8000 is 0.01 to 50 parts by weight with respect to 100 parts by weight of the polyester-based resin (A). Therefore, it has excellent adhesive strength to various adherends, and further has excellent holding power and tackiness. In particular, it is useful as an adhesive for electronic members and optical members. and a petroleum resin-based tackifier (B) having a number-average molecular weight of 400 to 8000. The content of the petroleum resin-based tackifier (B) having a number-average molecular weight of 400 to 8000 is 0.01 to 50 parts by weight with respect to 100 parts by weight of the polyester-based resin (A). Therefore, it has excellent adhesive strength to various adherends, and further has excellent holding power and tackiness. In particular, it is useful as an adhesive for electronic members and optical members. and a petroleum resin-based tackifier (B) having a number-average molecular weight of 400 to 8000. The content of the petroleum resin-based tackifier (B) having a number-average molecular weight of 400 to 8000 is 0.01 to 50 parts by weight with respect to 100 parts by weight of the polyester-based resin (A). Therefore, it has excellent adhesive strength to various adherends, and further has excellent holding power and tackiness. In particular, it is useful as an adhesive for electronic members and optical members. 400 to 8000 is 0.01 to 50 parts by weight with respect to 100 parts by weight of the polyester-based resin (A). Therefore, it has excellent adhesive strength to various adherends, and further has excellent holding power and tackiness. In particular, it is useful as an adhesive for electronic members and optical members. 400 to 8000 is 0.01 to 50 parts by weight with respect to 100 parts by weight of the polyester-based resin (A). Therefore, it has excellent adhesive strength to various adherends, and further has excellent holding power and tackiness. In particular, it is useful as an adhesive for electronic members and optical members. and further has excellent holding power and tackiness. In particular, it is useful as an adhesive for electronic members and optical members. and further has excellent holding power and tackiness. In particular, it is useful as an adhesive for electronic members and optical members.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, the configuration of the present invention will be described in detail, but these are examples of desirable embodiments It is a thing. In the present invention, "carboxylic acids" includes, in addition to carboxylic acids, carboxylic acid derivatives such as carboxylates, carboxylic acid anhydrides, carboxylic acid halides, and carboxylic acid esters In the present invention, "carboxylic acids" includes, in addition to carboxylic acids, carboxylic acid derivatives such as carboxylates, carboxylic acid anhydrides, carboxylic acid halides, and carboxylic acid esters It is a thing that contains.

[0013] The polyester-based pressure-sensitive adhesive composition of the present invention contains a polyester-based resin (A) and a petroleum resin-based tackifier (B) having a specific number-average molecular weight in a specific content ratio. Hereinafter, each component contained in the polyester-based pressure-sensitive adhesive composition of the present invention will be described. and a petroleum resin-based tackifier (B) having a specific number-average molecular weight in a specific content ratio. Hereinafter, each component contained in the polyester-based pressure-sensitive adhesive composition of the present invention will be described. and a petroleum resin-based tackifier (B) having a specific number-average molecular weight in a specific content ratio. Hereinafter, each component contained in the polyester-based pressure-sensitive adhesive composition of the present invention will be described.

[0014] <Polyester resin (A)> The polyester resin (A) has, as a resin composition, a structure derived from polycarboxylic acids (a1) units and structural units derived from polyols (a2), and usually, as constituent raw materials to copolymerize copolymer components containing polycarboxylic acids (a1) and polyols (a2) is obtained by this.

[0015] 〔Polycarboxylic acids (a1)〕 The above polycarboxylic acids (a1) used as constituent raw materials of the polyester resin (A) include, for example, divalent dicarboxylic acids and polyvalent carboxylic acids having three or more valences. Dicarboxylic acids are preferably used from the viewpoint of stably obtaining the polyester resin (A). The above polycarboxylic acids (a1) can be used alone or in combination of two or more species.

[0016] Examples of the above dicarboxylic acids include malonic acids, dimethylmalonic acids, succinic acids , glutaric acids, adipic acids, trimethyladipic acids, pimelic acids, 2,2-dimethyl glutaric acids, azelaic acids, sebacic acids, fumaric acids, maleic acids, itaconic acids, thiodipropionic acids, diglycolic acids, 1,9-nonanedicarboxylic acids, etc. of aliphatic dicarboxylic acids; phthalic acids, terephthalic acids, isophthalic acids, benzylmalonic acids, diphenic acids, 4 ,4'-oxydibenzoic acids, and further 1,8-naphthalenedicarboxylic acids, 2,3-naph thalenedicarboxylic acids, 2,7-naphthalenedicarboxylic acids, etc. of naphthalenedicarboxylic acids, etc. of aromatic dicarboxylic acids (a1-1); 1,3-cyclopentanedicarboxylic acids, 1,2-cyclohexanedicarboxylic acids, 1, 3-Cyclopentanedicarboxylic acids, 1,4-cyclohexanedicarboxylic acids, 2,5- alicyclic dicarboxylic acids such as norbornanedicarboxylic acids and adamantanedicarboxylic acids ; structural units 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.

[0017] Examples of the above polyvalent carboxylic acids having a valence of three or more include trimellitic acids, pyromellitic acids, adamantanetricarboxylic acids, trimesic acids, and the like.

[0018] Further, as the polyvalent carboxylic acid (a1), a compound containing a hydrogenated polybutadiene structure may be used and, for example, polybutadiene polyvalent carboxylic acids such as 1,2-polybutadiene dicarboxylic acids, 1,4-polybutadiene dicarboxylic acids, 1,4-polyisoprene dicarboxylic acids, etc. or saturated hydrocarbon polyvalent carboxylic acids obtained by saturating the double bonds of these polybutadiene polyvalent carboxylic acids with hydrogen or halogen, etc. may be mentioned. Furthermore, polyvalent carboxylic acids obtained by copolymerizing olefin compounds such as styrene, ethylene, vinyl acetate, acrylic acid ester, etc. with polybutadiene polyvalent carboxylic acids and hydrogenated polyvalent carboxylic acids thereof can also be used. Among them, hydrocarbon polybutadiene polyvalent carboxylic acids having a high degree of saturation are preferred, those having a number average molecular weight of 300 to 30,000, particularly 500 to 10,000, and further 8 00 to 5,000 are preferred, and those having an average functionality of carboxy groups of 1.5 to 3 are preferred.

[0019] Examples of the above compound containing a hydrogenated polybutadiene structure include those in the hydrogenated polybutadiene structure​​​​​​ At the 1,2-bonding site and the 1,4-bonding site, it is preferable that the proportion of the 1,2-bonding site is larger in terms of excellent adhesiveness to the polyolefin substrate. Also, the 1,2-bonding site occupying in the hydrogenated polybutadiene structure is preferably 25 to 100%, particularly preferably 50 to 100%, and especially preferably 75 to 100%. Among the above polycarboxylic acids (a1), aromatic dicarboxylic acids (a1-1) are preferable in terms of excellent adhesive strength and holding power. Furthermore, among the above aromatic dicarboxylic acids (a1-1), it is preferable to include asymmetric aromatic dicarboxylic acids (a1-1-1) in terms of reducing the crystallinity of the polyester resin (A). Examples of the asymmetric aromatic dicarboxylic acids (a1-1-1) include phthalic acids, isophthalic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, 2,7-naphthalenedicarboxylic acids, etc. Among them, isophthalic acids are particularly preferable in terms of reactivity. The content of such asymmetric aromatic dicarboxylic acids (a1-1-1) is preferably 0.1 to 70 mol% with respect to the total amount of polycarboxylic acids (a1), more preferably 0.5 to 60 mol%, still more preferably 1 to 50 mol%, particularly preferably 2 to 40 mol%, especially preferably 3 to 30 mol%, and most preferably 5 to 20 mol%. If the content is too small, the resin tends to crystallize and sufficient adhesive performance cannot be obtained. If it is too large, the initial adhesive strength (tack) tends to decrease.

[0020] Among the above polycarboxylic acids (a1), aromatic dicarboxylic acids (a1-1) are preferable from the viewpoints of excellent adhesive strength and holding power. Aromatic dicarboxylic acids (a1-1) are preferred.

[0021] Furthermore, among the above aromatic dicarboxylic acids (a1-1), in order to lower the crystallinity of the polyester resin (A), it is preferable to include asymmetric aromatic dicarboxylic acids (a1-1-1). Examples of the asymmetric aromatic dicarboxylic acids (a1-1-1) include phthalic acids, isophthalic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, 2,7-naphthalenedicarboxylic acids, etc. Among them, isophthalic acids are particularly preferable in terms of reactivity. It is preferably included, and examples of the asymmetric aromatic dicarboxylic acids (a1-1-1) include phthalic acids, isophthalic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, 2,7-naphthalenedicarboxylic acids, etc. Among them, isophthalic acids are particularly preferable in terms of reactivity. It is preferably included, and examples of the asymmetric aromatic dicarboxylic acids (a1-1-1) include phthalic acids, isophthalic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, 2,7-naphthalenedicarboxylic acids, etc. Among them, isophthalic acids are particularly preferable in terms of reactivity. phthalic acids, isophthalic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, 2,7-naphthalenedicarboxylic acids, etc. are exemplified, and among them, isophthalic acids are particularly preferable in terms of reactivity. phthalic acids, isophthalic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, 2,7-naphthalenedicarboxylic acids, etc. are exemplified, and among them, isophthalic acids are particularly preferable in terms of reactivity. isophthalic acids are particularly preferred.

[0022] The content of such asymmetric aromatic dicarboxylic acids (a1-1-1) is preferably 0.1 to 70 mol% with respect to the total amount of polycarboxylic acids (a1), more preferably 0.5 to 60 mol%, still more preferably 1 to 50 mol%, particularly preferably 2 to 40 mol%, especially preferably 3 to 30 mol%, and most preferably 5 to 20 mol%. If the content is too small, the resin tends to crystallize and sufficient adhesive performance cannot be obtained. If it is too large, the initial adhesive strength (tack) tends to decrease. The content of such asymmetric aromatic dicarboxylic acids (a1-1-1) is preferably 0.1 to 70 mol% with respect to the total amount of polycarboxylic acids (a1), more preferably 0.5 to 60 mol%, still more preferably 1 to 50 mol%, particularly preferably 2 to 40 mol%, especially preferably 3 to 30 mol%, and most preferably 5 to 20 mol%. If the content is too small, the resin tends to crystallize and sufficient adhesive performance cannot be obtained. If it is too large, the initial adhesive strength (tack) tends to decrease. is more preferably 0.5 to 60 mol%, still more preferably 1 to 50 mol%, particularly preferably 2 to 40 mol%, especially preferably 3 to 30 mol%, and most preferably 5 to 20 mol%. If the content is too small, the resin tends to crystallize and sufficient adhesive performance cannot be obtained. If it is too large, the initial adhesive strength (tack) tends to decrease. is particularly preferably 2 to 40 mol%, especially preferably 3 to 30 mol%, and most preferably 5 to 20 mol%. If the content is too small, the resin tends to crystallize and sufficient adhesive performance cannot be obtained. If it is too large, the initial adhesive strength (tack) tends to decrease. If the content is too small, the resin tends to crystallize and sufficient adhesive performance cannot be obtained. If it is too large, the initial adhesive strength (tack) tends to decrease. If the content is too large, the initial adhesive strength (tack) tends to decrease.

[0023] In the present invention, from the viewpoint of improving the initial adhesiveness (tack), aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms (including the carbon atoms of the carboxy group) are used as the polycarboxylic acids (a1). It is preferably contained, and among them, it is more preferably contained aliphatic dicarboxylic acids having 6 to 12 carbon atoms (including the carbon atoms of the carboxy group), and it is particularly preferably contained adipic acids, sebacic acids, and azelaic acids. From the viewpoint of excellent adhesiveness when using the petroleum resin-based tackifier resin (B) described later, it is particularly preferably contained sebacic acids. As the content of such aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms, it is preferably 5 to 100 mol% with respect to the total polycarboxylic acids (a1), more preferably 20 to 99 mol%, still more preferably 40 to 98 mol%, particularly preferably 60 to 97 mol%, and particularly preferably 80 to 95 mol%. If the content is too small, the glass transition temperature of the polyester resin (A) becomes too high, and there is a tendency that sufficient adhesiveness cannot be obtained. If it is too much, the resin tends to crystallize and sufficient adhesive performance cannot be obtained. In the present invention, from the viewpoint of adhesive physical properties, it is also preferable to use asymmetric aromatic dicarboxylic acids (a1-1-1) and aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms in combination as the polycarboxylic acids (a1). The content ratio (molar ratio) of the asymmetric aromatic dicarboxylic acids (a1-1-1) and the aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms is preferably (a1-1-1) / (a1-2)=0.1 / 99.9 to 70 / 30, more preferably In the present invention, from the viewpoint of improving the initial adhesiveness (tack), aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms (including the carbon atoms of the carboxy group) are used as the polycarboxylic acids (a1). It is preferably contained, and among them, it is more preferably contained aliphatic dicarboxylic acids having 6 to 12 carbon atoms (including the carbon atoms of the carboxy group), and it is particularly preferably contained adipic acids, sebacic acids, and azelaic acids. From the viewpoint of excellent adhesiveness when using the petroleum resin-based tackifier resin (B) described later, it is particularly preferably contained sebacic acids. It is particularly preferred.

[0024] As the content of such aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms, it is preferably 5 to 100 mol% with respect to the total polycarboxylic acids (a1), more preferably 20 to 99 mol%, still more preferably 40 to 98 mol%, particularly preferably 60 to 97 mol%, and particularly preferably 80 to 95 mol%. If the content is too small, the glass transition temperature of the polyester resin (A) becomes too high, and there is a tendency that sufficient adhesiveness cannot be obtained. If it is too much, the resin tends to crystallize and sufficient adhesive performance cannot be obtained. In the present invention, from the viewpoint of adhesive physical properties, it is also preferable to use asymmetric aromatic dicarboxylic acids (a1-1-1) and aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms in combination as the polycarboxylic acids (a1). The content ratio (molar ratio) of the asymmetric aromatic dicarboxylic acids (a1-1-1) and the aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms is preferably (a1-1-1) / (a1-2)=0.1 / 99.9 to 70 / 30, more preferably In the present invention, from the viewpoint of improving the initial adhesiveness (tack), aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms (including the carbon atoms of the carboxy group) are used as the polycarboxylic acids (a1). It is preferably contained, and among them, it is more preferably contained aliphatic dicarboxylic acids having 6 to 12 carbon atoms (including the carbon atoms of the carboxy group), and it is particularly preferably contained adipic acids, sebacic acids, and azelaic acids. From the viewpoint of excellent adhesiveness when using the petroleum resin-based tackifier resin (B) described later, it is particularly preferably contained sebacic acids. If the content is too small, the glass transition temperature of the polyester resin (A) becomes too high, and there is a tendency that sufficient adhesiveness cannot be obtained. If it is too much, the resin tends to crystallize and sufficient adhesive performance cannot be obtained.

[0025] In the present invention, from the viewpoint of adhesive physical properties, it is also preferable to use asymmetric aromatic dicarboxylic acids (a1-1-1) and aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms in combination as the polycarboxylic acids (a1). The content ratio (molar ratio) of the asymmetric aromatic dicarboxylic acids (a1-1-1) and the aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms is preferably (a1-1-1) / (a1-2)=0.1 / 99.9 to 70 / 30, more preferably In the present invention, from the viewpoint of adhesive physical properties, it is also preferable to use asymmetric aromatic dicarboxylic acids (a1-1-1) and aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms in combination as the polycarboxylic acids (a1). The content ratio (molar ratio) of the asymmetric aromatic dicarboxylic acids (a1-1-1) and the aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms is preferably (a1-1-1) / (a1-2)=0.1 / 99.9 to 70 / 30, more preferably In the present invention, from the viewpoint of adhesive physical properties, it is also preferable to use asymmetric aromatic dicarboxylic acids (a1-1-1) and aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms in combination as the polycarboxylic acids (a1). Preferably 0.5 / 99.5 to 60 / 40, more preferably 1 / 99 to 50 / 50, particularly preferably 2 / 98 to 40 / 60, especially preferably 3 / 97 to 30 / 70, most preferably is 5 / 95 to 20 / 80.

[0026] In addition, for the purpose of increasing the branching points in the polyester resin (A), polyvalent carboxylic acids having three or more valences can also be used. Among them, trimellitic acids are preferably used in terms of being relatively less likely to cause gelation.

[0027] As the content of such polyvalent carboxylic acids having three or more valences, in terms of being able to increase the cohesive force of the adhesive, preferably 10 mol% or less, particularly preferably 0.1 to 5 mol% with respect to the total amount of the polyvalent carboxylic acids (a1). If such a content is too high, there is a tendency for gelation to occur during the production of the polyester resin (A ).

[0028] 〔Polyol (a2)〕 As the polyol (a2) used as a constituent raw material of the polyester resin (A), for example, divalent diols, polyols having three or more valences, etc. can be mentioned. The polyol (a2) can be used alone or in combination of two or more.

[0029] Examples of the above diol include 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 and other aliphatic diols; 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, spiroglycol, tricyclodecane dimethanol, adamantane diol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol and other alicyclic diols; 4,4'-thiodiphenol, 4,4'-methylenediphenol, bisphenol, bisphenol fluorene, 4,4'-dihydroxybiphenyl, o-, m- and p-dihydroxybenzene, 2,5-naphthalenediol, p-xylenediol and other aromatic diols; and ethylene oxide and propylene oxide adducts thereof. ; 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, spiroglycol, tricyclodecane dimethanol, adamantane diol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol and other alicyclic diols; 4,4'-thiodiphenol, 4,4'-methylenediphenol, bisphenol, bisphenol fluorene, 4,4'-dihydroxybiphenyl, o-, m- and p-dihydroxybenzene, 2,5-naphthalenediol, p-xylenediol and other aromatic diols; and ethylene oxide and propylene oxide adducts thereof. ; 4,4'-thiodiphenol, 4,4'-methylenediphenol, bisphenol, bisphenol fluorene, 4,4'-dihydroxybiphenyl, o-, m- and p-dihydroxybenzene, 2,5-naphthalenediol, p-xylenediol and other aromatic diols; and ethylene oxide and propylene oxide adducts thereof. 4,4'-thiodiphenol, 4,4'-methylenediphenol, bisphenol, bisphenol fluorene, 4,4'-dihydroxybiphenyl, o-, m- and p-dihydroxybenzene, 2,5-naphthalenediol, p-xylenediol and other aromatic diols; and ethylene oxide and propylene oxide adducts thereof. 4,4'-thiodiphenol, 4,4'-methylenediphenol, bisphenol, bisphenol fluorene, 4,4'-dihydroxybiphenyl, o-, m- and p-dihydroxybenzene, 2,5-naphthalenediol, p-xylenediol and other aromatic diols; and ethylene oxide and propylene oxide adducts thereof. 4,4'-thiodiphenol, 4,4'-methylenediphenol, bisphenol, bisphenol fluorene, 4,4'-dihydroxybiphenyl, o-, m- and p-dihydroxybenzene, 2,5-naphthalenediol, p-xylenediol and other aromatic diols; and ethylene oxide and propylene oxide adducts thereof. ; and ethylene oxide and propylene oxide adducts thereof. Furthermore, fatty acid esters derived from castor oil, dimer diols derived from oleic acid, erucic acid, etc., glycerol monostearate and the like can be mentioned. ; and ethylene oxide and propylene oxide adducts thereof.

[0030] Examples of the above polyhydric alcohols having three or more valences include pentaerythritol, dipentaerythritol, tripentaerythritol, glycerin, trimethylolpropane, trimethylolethane, 1,3,6-hexanetriol, adamantanetriol and the like. Examples of the above polyhydric alcohols having three or more valences include pentaerythritol, dipentaerythritol, tripentaerythritol, glycerin, trimethylolpropane, trimethylolethane, 1,3,6-hexanetriol, adamantanetriol and the like. ; and ethylene oxide and propylene oxide adducts thereof. ; and ethylene oxide and propylene oxide adducts thereof.

[0031] Also, as the polyol (a2), hydrogenated polybutadiene polyol (a2-1) can be used. ; and ethylene oxide and propylene oxide adducts thereof. Examples of the hydrogenated polybutadiene polyol (a2-1) include, for example, 1,2-polybuta diene polyol, 1,4-polybutadiene polyol, 1,4-polyisoprene poly ol such as polybutadiene-based polyols or saturated hydrocarbon-based polyols obtained by saturating the double bonds of these polybutadiene-based polyols with hydrogen, halogen, etc. Examples thereof include saturated hydrocarbon-based polyols obtained by saturating the double bonds of these polybutadiene-based polyols with hydrogen, halogen, etc. Furthermore, polyols obtained by copolymerizing olefin compounds such as styrene, ethylene, vinyl acetate, and acrylic acid esters with polybutadiene-based polyols, and hydrogenated polyols thereof, etc. can also be used. Among them, hydrocarbon-based polybutadiene polyols with a high degree of saturation are preferred, and the number average molecular weight is preferably 300 to 30,000, more preferably 500 to 10,000, even more preferably 800 to 5,000, and it is preferable that the average functionality of the hydroxyl groups is 1.5 to 3.

[0032] As the hydrogenated polybutadiene polyol (a2-1), in the hydrogenated polybutadiene structure, at the 1,2-bonding site and the 1,4-bonding site, it is preferable that the proportion of the 1,2-bonding site is larger in terms of excellent adhesion to the polyolefin substrate. Also, the proportion of the 1,2-bonding site in the hydrogenated polybutadiene structure is preferably 25 to 100%, particularly preferably 50 to 100% and especially preferably 75 to 100%.

[0033] Among the above polyols (a2), it is preferable to use the hydrogenated polybutadiene polyol (a2-1) from the viewpoint of excellent adhesion to the polyolefin substrate.

[0034] The content of the hydrogenated polybutadiene polyol (a2-1) is relative to the polyol (a2). ​​and preferably in an amount of 0.001 to 15 mol%, more preferably 0.005 to 10 mol%, still more preferably 0.01 to 5 mol%, particularly preferably 0.05 to 2 mol%, and especially preferably 0.1 to 1 mol%. If the content is too small, the adhesiveness to the polyolefin material tends to decrease, and if it is too large, the compatibility

[0035] tends to decrease. Further, as the above polyol (a2), it is preferable to contain a polyol (a2-2) containing a branched structure from the viewpoint of increasing the number of branching points and disrupting crystallinity. Examples of the polyol (a2-2) containing a branched structure include neopentyl glycol, 2-methyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,3,5-trimethyl-1,3-pentanediol, 2-methyl-1,6-hexanediol, dimer diol, and the like. Among them, neopentyl glycol is particularly preferred. In addition, as the polyol (a2-2) containing a branched structure, those other than the above hydrogenated polybutadiene polyol (a2-1) are used.

[0036] The content of the above polyol (a2-2) containing a branched structure is preferably 5 to 100 mol% based on the total amount of the polyol (a2), more preferably 10 to 90 mol%, still more preferably 20 to 80 mol%, particularly preferably 30 to 70 mol%, and It is 0 mol%. If such content is too low, the resin tends to crystallize and it is difficult to obtain sufficient adhesive performance. If it is too much, the reaction time tends to be long in the production of the polyester resin (A).

[0037] On the other hand, as the above polyol (a2), it is preferable to contain a linear polyol (a2-3) from the viewpoint of reactivity. More preferably, a linear polyol having 2 to 40 carbon atoms is used. Examples of such linear polyol (a2-3) include aliphatic glycols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, etc. Among them, ethylene glycol, 1,4-butanediol, and 1,6-hexanediol are particularly preferable.

[0038] The content of the linear polyol (a2-3) is preferably 5 to 100 mol%, more preferably 10 to 90 mol%, still more preferably 20 to 80 mol%, and particularly preferably 30 to 60 mol% based on the total polyol (a2). If such content is too low, it tends to be difficult to obtain stable resin formation.

[0039] Also, for the purpose of increasing the number of branch points in the polyester resin (A), it is also preferable to use a polyol having three or more valences. Examples of the polyol having three or more valences include pentaerythritol, dipentaerythritol, tripentaerythritol, glycerin, trimethylolpropane, trimethylolethane, 1,3,6-hexanetriol, adamantantriol, ​​​​​​​​​​​ Examples include a loop or the like.

[0040] The content of such a polyol having a valency of 3 or more is preferably 2 0 mol% or less, more preferably 0.1 to 10 mol%, and particularly preferably 0.5 to 5 mol%. If the content is too large, the production of the polyester resin (A ) tends to be difficult.

[0041] The polyester resin (A) used in the present invention is arbitrarily selected from the above polycarboxylic acids (a1) and poly ols (a2), and these are subjected to a polycondensation reaction by a known method in the presence of a catalyst. It is produced by

[0042] The mixing ratio of the polycarboxylic acids (a1) and the polyol (a2) is preferably 1 to 3 equivalents of the polyol (a2) per 1 equivalent of the polycarboxylic acid s (a1), and particularly preferably 1.1 to 2 equivalents. If the mixing ratio of the polyol (a2) is too small, the acid value tends to be high and it tends to be difficult to increase the molecular weight. If it is too large, the yield tends to decrease.

[0043] In the above polycondensation reaction, first, an esterification reaction is carried out, and then a polycondensation reaction is carried out. . In such an esterification reaction, a catalyst is used. Specifically, for example, titanium-based catalysts such as tetraisopropyl titanate and tetrabutyl titanate, antimony-based catalysts such as antimony trioxide, germanium-based catalysts such as germanium dioxide, and catalysts such as zinc acetate, manganese acetate, and dibutyltin oxide can be mentioned, and one or two or more of these are used. Among these, from the balance of high catalytic activity and hue, three Antimony oxide, tetrabutyl titanate, germanium dioxide, and zinc acetate are preferred.

[0044] The blending amount of the above catalyst is preferably 1 to 10,000 ppm based on all the copolymerization components, particularly preferably 10 to 5,000 ppm, and more preferably 20 to 3,000 ppm. If such a blending amount is too small, the polymerization reaction tends not to proceed sufficiently. If it is too large, there are no advantages such as shortening the reaction time, and side reactions tend to occur easily.

[0045] 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. If it is too high, side reactions such as decomposition tend to occur easily. Also, the pressure during the reaction is usually normal pressure.

[0046] After the above esterification reaction is carried out, a polycondensation reaction is carried out. As the reaction conditions for the polycondensation reaction, the same catalyst as that used in the above esterification reaction is blended in the same amount, and the reaction temperature is preferably 220 to 280 °C, particularly preferably 230 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. If it is too high, side reactions such as decomposition tend to occur easily.

[0047] Thus, the polyester resin (A) used in the present invention is obtained.

[0048] The above polyester resin (A) usually has structural units derived from polycarboxylic acids (a1) and structural units derived from polyols (a2), but the asymmetric aromatic dicarboxylic acids (a1-1-1) When the structural unit derived from is included as the structural unit derived from polycarboxylic acids (a1), if the structural unit derived from asymmetric aromatic dicarboxylic acids (a1-1-1) is included, it is preferably contained in the structural unit derived from polycarboxylic acids (a1) in an amount of 0.1 to 70 mol%, more preferably 0.5 to 60 mol%, still more preferably 1 to 50 mol%, particularly preferably 2 to 40 mol%, especially preferably 3 to 30 mol%, and most preferably 5 to 20 mol%.

[0049] Also, when the structural unit derived from aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms is included as the structural unit derived from polycarboxylic acids (a1), the structural unit derived from aliphatic dicarboxylic acids (a1-2) having 4 or more carbon atoms is preferably contained in the structural unit derived from polycarboxylic acids (a1) in an amount of 5 to 100 mol%, more preferably 20 to 99 mol%, still more preferably 40 to 98 mol%, particularly preferably 60 to 97 mol%, especially preferably 80 to 95 mol%.

[0050] Also, when the polyester resin (A) contains a structural unit derived from a hydrogenated polybutadiene structure-containing compound, the content of the structural unit derived from the hydrogenated polybutadiene structure-containing compound in the polyester resin (A) is preferably 0.01 to 50% by weight, more preferably 0.1 to 30% by weight, still more preferably 0.2 to 20% by weight, particularly preferably 0.3 to 1 0% by weight, especially preferably 0.4 to 5% by weight, and most preferably 0.5 to 2% by weight.

[0051] In the above polyester resin (A), the structural unit derived from the hydrogenated polybutadiene structure-containing compound The units are preferably included as at least one of the structural units derived from polycarboxylic acids (a1) and the structural units derived from polyols (a2) from the viewpoint of adhesion to the polyolefin substrate, and more preferably included as the structural units derived from polyols (a2). When the structural units derived from the hydrogenated polybutadiene polyol (a2-1) are included as the structural units derived from the polyol (a2), from the viewpoint of compatibility, the structural units derived from the hydrogenated polybutadiene polyol (a2-1) are preferably contained in the structural units derived from the polyol (a2) in an amount of 0.001 to 15 mol%, more preferably 0.005 to 10 mol%, even more preferably 0.01 to 5 mol%, particularly preferably 0.05 to 2 mol%, and especially preferably 0.1 to 1 mol%.

[0052] On the other hand, when the structural units derived from the branched-structure-containing polyol (a2-2) are included as the structural units derived from the polyol (a2), in terms of disrupting the crystallinity of the polyester resin (A), the structural units derived from the branched-structure-containing polyol (a2-2) are preferably contained in the structural units derived from the polyol (a2) in an amount of 5 to 100 mol%, more preferably 10 to 90 mol%, even more preferably 20 to 80 mol%, particularly preferably 30 to 70 mol%, and especially preferably 40 to 60 mol%. When the structural units derived from the linear polyol (a2-3) are included as the structural units derived from the polyol (a2), from the viewpoint of stable resin formation, the structural units derived from the linear polyol (a2-3) are contained in the structural units derived from the polyol (a2) in an amount of 5 to 100 mol%. even more preferably 0.01 to 5 mol%, particularly preferably 0.05 to 2 mol%, and especially preferably 0.1 to 1 mol%. even more preferably 20 to 80 mol%, particularly preferably 30 to 70 mol%, and especially preferably 40 to 60 mol%. even more preferably 20 to 80 mol%, particularly preferably 30 to 70 mol%, and especially preferably 40 to 60 mol%.

[0053] When the structural units derived from the branched-structure-containing polyol (a2-2) are included as the structural units derived from the polyol (a2), in terms of disrupting the crystallinity of the polyester resin (A), the structural units derived from the branched-structure-containing polyol (a2-2) are preferably contained in the structural units derived from the polyol (a2) in an amount of 5 to 100 mol%, more preferably 10 to 90 mol%, even more preferably 20 to 80 mol%, particularly preferably 30 to 70 mol%, and especially preferably 40 to 60 mol%. On the other hand, when the structural units derived from the linear polyol (a2-3) are included as the structural units derived from the polyol (a2), from the viewpoint of stable resin formation, the structural units derived from the linear polyol (a2-3) are contained in the structural units derived from the polyol (a2) in an amount of 5 to 100 mol%. even more preferably 20 to 80 mol%, particularly preferably 30 to 70 mol%, and especially preferably 40 to 60 mol%. even more preferably 20 to 80 mol%, particularly preferably 30 to 70 mol%, and especially preferably 40 to 60 mol%. even more preferably 20 to 80 mol%, particularly preferably 30 to 70 mol%, and especially preferably 40 to 60 mol%.

[0054] When the structural units derived from the linear polyol (a2-3) are included as the structural units derived from the polyol (a2), from the viewpoint of stable resin formation, the structural units derived from the linear polyol (a2-3) are contained in the structural units derived from the polyol (a2) in an amount of 5 to 100 mol%. even more preferably 20 to 80 mol%, particularly preferably 30 to 70 mol%, and especially preferably 40 to 60 mol%. even more preferably 20 to 80 mol%, particularly preferably 30 to 70 mol%, and especially preferably 40 to 60 mol%. Preferably, more preferably 10 to 90 mol%, even more preferably 20 to 80 mol% , particularly preferably 30 to 60 mol%.

[0055] Here, the proportion (composition ratio) of the structural units derived from each component of the polyester resin (A) is For example, it can be determined by NMR.

[0056] The glass transition temperature of the polyester resin (A) is -80 to 20 °C from the viewpoint of adhesive physical properties Preferably, particularly preferably -75 to 10 °C, even more preferably -70 to -2 0 °C, more preferably -65 to -30 °C, particularly preferably -60 to -35 °C, most preferably is -55 to -40 °C. If such a glass transition temperature is too high, flexibility is lost and initial adhesiveness decreases, and it becomes difficult to exhibit adhesive force with a pressure of about finger pressure, and workability tends to decrease There is a tendency, and if it is too low, the cohesive force decreases, and the adhesive sheet is likely to be deformed, deteriorating the appearance There is a tendency.

[0057] Here, the glass transition temperature (Tg) of the polyester resin (A) is a value measured using a differential scanning calorimeter DSC Q20 manufactured by TA Instruments Co., Ltd. The measurement temperature range is -90 to 100 °C, and the temperature increase rate is 10 °C / min.

[0058] The ester bond concentration of the polyester resin (A) is preferably 3 to 9 mmol / g, more preferably 4 to 9 mmol / g, even more preferably 4.5 to 8.5 mmol / g, particularly preferably 5 to 8 mmol / g. If such an ester bond concentration is too small, the polyester resin (A) becomes soft and the adhesive properties tend to decrease. Also, the ester bond If the concentration is too high, the polyester resin (A) becomes hard and the adhesive properties tend to deteriorate. There is.

[0059] The above ester bond concentration (mmol / g) refers to the number of moles of ester bonds in 1 g of the polyester resin, and is obtained, for example, as a calculated value from the charged amounts. Such a calculation method is the value obtained by dividing the smaller number of moles of the charged amounts of the polycarboxylic acids (a1) and the polyol (a2) by the total weight, and an example of the calculation formula is shown below. In the case where the charged amounts of the polycarboxylic acids (a1) and the polyol (a2) are the same number of moles either of the following calculation formulas may be used.

[0060] <When the polycarboxylic acids (a1) are less than the polyol (a2)> Ester bond concentration (mmol / g) = [(A1 / a1 × m1 + A2 / a2 × m2 + A3 / a3 × m3 ···) / Z] × 1000 A1, A2, A3 ···: Charged amount of the polycarboxylic acids (a1) (g) a1, a2, a3 ···: Molecular weight of the polycarboxylic acids (a1) m1, m2, m3 ···: Number of carboxy groups per molecule of the polycarboxylic acids (a1) Z: Final weight (g) <When the polyol (a2) is less than the carboxylic acids (a1)> Ester bond concentration (mmol / g) = [(B1 / b1 × n1 + B2 / b2 × n2 + B3 / b3 × n3 ···) / Z] × 1000 B1, B2, B3 ···: Charged amount of the polyol (a2) (g) b1, b2, b3 ···: Molecular weight of polyol (a2) n1, n2, n3 ···: Number of hydroxyl groups per molecule of polyol (a2) Z: Finished weight (g)

[0061] Also, the above ester bond concentration can also be measured by a known method using NMR or the like. 。 For example, the ester group concentration of the polyester resin (A) is determined by 1 H -NMR measurement (proton nuclear magnetic resonance spectroscopy), 13 C-NMR measurement (carbon nuclear magnetic resonance spectroscopy).

[0062] The above polyester resin (A) is preferably non-crystallizing from the viewpoint of storage stability. However, even when crystallized, it is preferable that the heat of crystal fusion of the polyester resin (A) is as low as possible. It is usually 35 J / g or less, preferably 20 J / g or less, particularly preferably 10 J / g or less, especially preferably 5 J / g or less, more preferably 3 J / g or less, and most preferably 1 J / g or less. The above heat of crystal fusion refers to the change in energy when a crystallized solid substance changes to a liquid state, and can be measured by a differential scanning calorimeter DSC.

[0063] The acid value of the above polyester resin (A) is preferably 10 mgKOH / g or less, particularly 3 mgKOH / g or less, more preferably 1.5 mgKOH / g or less, and still more preferably 1 mgKOH / g or less. If the acid value is too high, hydrolysis tends to proceed and the cohesive force tends to decrease.

[0064] Also, the hydroxyl value of the above polyester resin (A) is preferably 50 mgKOH / g or less is preferable, particularly 30 mgKOH / g or less, more preferably 20 mgKOH / g or less, and still more preferably 15 mgKOH / g or less. If the hydroxyl value is too high, the crosslinking efficiency with the crosslinking agent (D) described below tends to decrease.

[0065] The acid value and hydroxyl value of the above polyester resin (A) are determined by neutralization titration based on JIS K 0070.

[0066] In addition, the weight average molecular weight of the above polyester resin (A) is preferably 5 000 to 300,000 from the viewpoint of the cohesive force of the adhesive, particularly 8,000 to 200,000, more preferably 10,000 to 120,000, especially preferably 30,000 to 100,000. If such a weight average molecular weight is too small, sufficient cohesive force as an adhesive cannot be obtained, and the heat resistance and mechanical strength tend to decrease. If it is too large, gelation is likely to occur during the production of the polyester resin (A), and it tends to be difficult to obtain the resin.

[0067] The number average molecular weight of the above polyester resin (A) is preferably 3,000 to 100,000, more preferably 4,000 to 80,000, still more preferably 5,000 to 50,000, particularly preferably 6,000 to 30,000, especially preferably 7,000 to 20,000. If the number average molecular weight is too small, sufficient cohesive force as an adhesive cannot be obtained, and the heat resistance and mechanical strength tend to decrease. If it is too large, the adhesion to the substrate tends to decrease.

[0068] The weight average molecular weight and number average molecular weight of the present invention are based on standard polystyrene molecular weight conversion, and are measured using a high performance liquid chromatograph (manufactured by Tosoh Corporation, "HLC-8320GPC"). Column: TSKgel SuperMultipore HZ-M (exclusion limit molecular weight: 2 ×10 6 , theoretical number of plates: 16,000 plates / column, packing material: styrene-divinylbenzene copolymer mer, packing particle size: 4 μm) measured by using two columns in series.

[0069] <Petroleum resin-based tackifier (B)> The polyester-based pressure-sensitive adhesive composition of the present invention contains the above polyester-based resin (A) and a petroleum resin-based tackifier (B) having a specific number-average molecular weight. As described above, the petroleum resin-based tackifier has a low polarity and poor compatibility with the highly polar polyester-based resin. Therefore, it is generally difficult to use them by mixing. Moreover, it is even more difficult when trying to improve tackiness. However, the present invention has found that when the polyester-based resin (A) is used as the base resin, by blending the polyester-based resin (A) and a petroleum resin-based tackifier (B) having a specific number-average molecular weight at a specific content ratio, a polyester-based pressure-sensitive adhesive composition excellent in adhesive strength, holding power, and tackiness can be obtained. The number-average molecular weight of the above petroleum resin-based tackifier (B) is 400 to 8000. Preferably it is 500 to 5000, more preferably 600 to 3000, particularly preferably 700 to 2 000, and especially preferably 750 to 1500. When the number-average molecular weight of the petroleum resin-based tackifier (B) is within the above range, it is excellent in adhesive strength, holding power, and tackiness. The number-average molecular weight of the above petroleum resin-based tackifier (B) can be measured by the same method as the above polyester-based resin (A). The number-average molecular weight of the above petroleum resin-based tackifier (B) can be measured in the same manner as the above polyester-based resin (A). The polyester-based pressure-sensitive adhesive composition is excellent in adhesive strength, holding power, and tackiness. The polyester-based pressure-sensitive adhesive composition is excellent in adhesive strength, holding power, and tackiness.

[0070] The number-average molecular weight of the above petroleum resin-based tackifier (B) is 400 to 8000. Preferably it is 500 to 5000, more preferably 600 to 3000, particularly preferably 700 to 2 000, and especially preferably 750 to 1500. When the number-average molecular weight of the petroleum resin-based tackifier (B) is within the above range, it is excellent in adhesive strength, holding power, and tackiness. The number-average molecular weight of the above petroleum resin-based tackifier (B) can be measured by the same method as the above polyester-based resin (A). The number-average molecular weight of the above petroleum resin-based tackifier (B) can be measured in the same manner as the above polyester-based resin (A). The number-average molecular weight of the above petroleum resin-based tackifier (B) can be measured in the same manner as the above polyester-based resin (A).

[0071] The weight average molecular weight of the above petroleum resin-based tackifier (B) is 400 to 10,000 is preferable, particularly 600 to 8,000, more preferably 800 to 4,000, and especially preferably 1,000 to 2 000. When the weight average molecular weight of the petroleum resin-based tackifier (B) is within the above range , it is excellent in adhesive strength, holding power, and tackiness. The weight average molecular weight of the above petroleum resin-based tackifier (B ) can be measured by the same method as the above polyester resin (A).

[0072] Examples of the above petroleum resin-based tackifier (B) include aliphatic (C5-based) petroleum resins, aromatic (C9-based) petroleum resins, aliphatic / aromatic copolymer (C5 / C9-based) petroleum resins, and hydrogenated petroleum resins obtained by hydrogenating these, alicyclic petroleum resins such as dicyclopentadiene, and coumarone-indene resins. These may be used alone or in combination of two or more. Among these, from the viewpoint of excellent adhesive strength, holding power, and tackiness, it preferably has an aromatic ring structure, more preferably an aromatic (C9-based) petroleum resin or an aliphatic / aromatic copolymer (C5 / C9-based) petroleum resin, and particularly preferably an aliphatic / aromatic copolymer (C5 / C9-based) petroleum resin. Among them, it is preferable that the aromatic ring structure is derived from a styrene-based resin.

[0073] Among the above petroleum resin-based tackifiers (B), from the viewpoint of excellent adhesive strength, holding power, and tackiness , it preferably has an aromatic ring structure, more preferably an aromatic (C9-based) petroleum resin or an aliphatic / aromatic copolymer (C5 / C9-based) petroleum resin, and particularly preferably an aliphatic / aromatic copolymer (C5 / C9-based) petroleum resin. Among them, it is preferable that the aromatic ring structure is derived from a styrene-based resin.

[0074] The above styrene-based resin is preferably a styrene-based polymer, but may also be a mixture of a styrene-based monomer and a styrene-based polymer. Further, the above styrene-based polymer may be a homopolymer or copolymer of one or more styrene-based monomers, and 1 ​​​​​​​​​It is a copolymer of one or more styrene monomers and other monomers other than styrene monomers. It may be.

[0075] Examples of the above styrene polymers include polystyrene, poly-α-methylstyrene, a copolymer of α-methylstyrene and styrene, a copolymer of a styrene monomer and an aliphatic monomer, a copolymer of a styrene monomer and an aromatic monomer, a copolymer of α-methylstyrene and a styrene monomer other than α-methylstyrene, etc. Among them, from the viewpoints of excellent adhesiveness, holding power, and tackiness, a copolymer of styrene monomers, a copolymer of a styrene monomer and an aliphatic monomer are preferred.

[0076] Examples of the above styrene monomers include styrene, 2-methylstyrene, 4-methyl styrene, 4-ethylstyrene, 4-t-butylstyrene, 2,4-dimethylstyrene and other alkyl-substituted styrenes such as α-methylstyrene, α-methyl-4-methylstyrene, etc. α-alkyl-substituted styrenes, and substituted styrenes such as 2-chlorostyrene, 4-chlorostyrene, hydroxystyrene, vinylbenzoic acid, etc.

[0077] In addition, examples of other monomers other than the above styrene monomers include aliphatic monomers and aromatic monomers. Examples of the above aliphatic monomers include aliphatic hydrocarbons. Examples of the above aromatic monomers include aromatic hydrocarbons other than those exemplified by the above styrene monomers.

[0078] Examples of commercially available products of the copolymer of the above styrene monomer and aliphatic monomer include, for example, ​Examples include "FTR6100", "FTR6110", "FTR6125", etc. manufactured by Mitsui Chemicals, Inc. and the like.

[0079] Examples of commercially available copolymers of the above styrene-based monomers include, for example, "FTR 2120", "FTR2140", "FTR8100", "FTR8120", etc. and the like.

[0080] The softening point (for example, measured by the ring and ball method) of the above petroleum resin-based tackifier (B) is preferably 30 to 200 °C, particularly preferably 60 to 180 °C, more preferably 70 to 160 °C, still more preferably 80 to 140 °C, and especially preferably 90 to 1 30 °C. When the softening point is within the above range, the adhesive strength, holding power, and tackiness tend to be excellent. and the like.

[0081] The above petroleum resin-based tackifier (B) preferably has an acid value of 5 mgKOH / g or less, particularly 3 mgKOH / g or less, further 2 mgKOH / g or less, and especially 1 mgKOH / g or less. When using a plurality of types of tackifier resins in combination, the average is preferably within the above range. and the like. and the like.

[0082] In addition, the above petroleum resin-based tackifier (B) preferably has a hydroxyl value of 5 mgKOH / g or less, particularly 3 mgKOH / g or less, further 2 mgKOH / g or less, and especially 1 mgKOH / g or less. When using a plurality of types of tackifier resins in combination, the average is preferably within the above range. and the like.

[0083] Note that the acid value and hydroxyl value of the above petroleum resin-based tackifier (B) are determined in accordance with JIS K 0070. This can be determined by neutralization titration based on the above.

[0084] The content of the petroleum resin-based tackifier (B) is based on 100 parts by weight of the polyester resin (A). The amount is preferably 0.01 to 50 parts by weight, more preferably 1 to 40 parts by weight, and even more preferably Preferably, it is 2 to 30 parts by weight, more preferably 3 to 25 parts by weight, and particularly preferably 4 to 50 parts by weight. The content is preferably from 1 to 20 parts by weight, and more preferably from 5 to 15 parts by weight. This provides excellent adhesion, holding power and tackiness.

[0085] The polyester-based pressure-sensitive adhesive composition of the present invention contains the above-mentioned polyester-based resin (A), petroleum resin In addition to the tackifier (B), preferably, a hydrolysis inhibitor (C), a crosslinking agent (D), a urea-based tackifier (E), and a tackifier (F) are also used. A tanning catalyst (E) and, if necessary, an antioxidant and the like may be contained.

[0086] <Hydrolysis inhibitor (C)> The hydrolysis inhibitor (C) ensures the long-term durability of the polyester-based pressure-sensitive adhesive composition. It is contained for this purpose. As the hydrolysis inhibitor (C), a conventionally known one can be used. For example, Compounds that react with the carboxyl end of the polyester resin (A) to bond thereto are exemplified. Specifically, functional groups such as carbodiimide groups, epoxy groups, and oxazoline groups are Among these, compounds containing a carbodiimide group are particularly preferred. This is preferred because it is highly effective in eliminating the catalytic activity of the protons derived from the carboxyl group terminals.

[0087] The carbodiimide group-containing compound is usually a carbodiimide group (-N=C=N- ) in the molecule, but it is difficult to use them under high temperature and high humidity conditions. A compound containing two or more carbodiimide groups in the molecule, that is, a polyvalent carbodiimide compound, is preferred in terms of improving durability. In particular, a compound containing three or more, more preferably five or more, and particularly preferably seven or more carbodiimide groups in the molecule is preferred. Note that the number of carbodiimide groups in the molecule is usually 50 or less. If there are too many carbodiimide groups, the molecular structure becomes too large, and the compatibility tends to decrease. Further, it is also preferred to use a high molecular weight polycarbodiimide produced by subjecting a diisocyanate to a decarboxylation condensation reaction in the presence of a carbodiimidization catalyst. Moreover, it is preferred that the terminal isocyanate groups of the high molecular weight polycarbodiimide are blocked by a blocking agent in terms of storage stability. Examples of the blocking agent include a compound having active hydrogen that reacts with an isocyanate group, or a compound 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 can be mentioned. Examples of such high molecular weight polycarbodiimides include those obtained by subjecting the following diisocyanates to a decarboxylation condensation reaction. 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'-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate. In terms of improving durability, a compound containing two or more carbodiimide groups in the molecule, that is, a polyvalent carbodiimide compound, is preferred. In particular, a compound containing three or more, more preferably five or more, and particularly preferably seven or more carbodiimide groups in the molecule is preferred. Note that the number of carbodiimide groups in the molecule is usually 50 or less. If there are too many carbodiimide groups, the molecular structure becomes too large, and the compatibility tends to decrease. Further, it is also preferred to use a high molecular weight polycarbodiimide produced by subjecting a diisocyanate to a decarboxylation condensation reaction in the presence of a carbodiimidization catalyst. Moreover, it is preferred that the terminal isocyanate groups of the high molecular weight polycarbodiimide are blocked by a blocking agent in terms of storage stability. Examples of the blocking agent include a compound having active hydrogen that reacts with an isocyanate group, or a compound 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 can be mentioned.

[0088] Moreover, it is preferred that the terminal isocyanate groups of the high molecular weight polycarbodiimide are blocked by a blocking agent in terms of storage stability. Examples of the blocking agent include a compound having active hydrogen that reacts with an isocyanate group, or a compound 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 can be mentioned. Examples of such high molecular weight polycarbodiimides include those obtained by subjecting the following diisocyanates to a decarboxylation condensation reaction. 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'-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate. In terms of improving durability, a compound containing two or more carbodiimide groups in the molecule, that is, a polyvalent carbodiimide compound, is preferred. In particular, a compound containing three or more, more preferably five or more, and particularly preferably seven or more carbodiimide groups in the molecule is preferred. Note that the number of carbodiimide groups in the molecule is usually 50 or less. If there are too many carbodiimide groups, the molecular structure becomes too large, and the compatibility tends to decrease. Further, it is also preferred to use a high molecular weight polycarbodiimide produced by subjecting a diisocyanate to a decarboxylation condensation reaction in the presence of a carbodiimidization catalyst. Moreover, it is preferred that the terminal isocyanate groups of the high molecular weight polycarbodiimide are blocked by a blocking agent in terms of storage stability. Examples of the blocking agent include a compound having active hydrogen that reacts with an isocyanate group, or a compound 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 can be mentioned.

[0089] Examples of such high molecular weight polycarbodiimides include those obtained by subjecting the following diisocyanates to a decarboxylation condensation reaction. 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'-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate.

[0090] 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'-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate. 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'-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate. 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'-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate. 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'-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate. , 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1-methoxy phenyl-2,4-diisocyanate, isophorone diisocyanate, 4,4'-di cyclohexylmethane diisocyanate, tetramethylxylylene diisocyanate, etc. are exemplified and these can be used alone or in combination of two or more. Such high molecular weight polycarbodiimide may be synthesized or a commercially available product may be used.

[0091] Examples of commercially available products of the carbodiimide group-containing compound include, for example, the Carbodilite (registered trademark) series manufactured by Nisshinbo Chemicals Co., Ltd. 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).

[0092] Examples of the epoxy group-containing compound include, for example, glycidyl ester compounds and glycidyl ether compounds, etc. are preferable.

[0093] Specific examples of the glycidyl ester compound include, for example, glycidyl benzoate, glycidyl t-Bu-benzoate, glycidyl p-toluate, glycidyl cyclohexanecarboxylate, glycidyl pelargonate, glycidyl stearate, glycidyl laurate, glycidyl palmitate, glycidyl behenate, glycidyl versatate, glycidyl oleate, glycidyl linoleate, glycidyl linolenate, ​​​​​Glycidyl behenate, glycidyl stearate, terephthalic acid di glycidyl ester, isophthalic acid diglycidyl ester, phthalic acid diglycidyl es ter, naphthalenedicarboxylic acid diglycidyl ester, methyl terephthalic acid diglycidyl e ster, hexahydrophthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl l ester, cyclohexanedicarboxylic acid diglycidyl ester, adipic acid diglycidyl l ester, succinic acid diglycidyl ester, sebacic acid diglycidyl ester, dodeca ndioic acid diglycidyl ester, octadecanedicarboxylic acid diglycidyl ester, tri glycidyl trimellitate, tetraglycidyl pyromellitate, etc. can be mentioned, and these can be used alone or in combination of two or more.

[0094] Specific examples of the above glycidyl ether compounds include, for example, phenyl glycidyl e-ther l, o-phenyl glycidyl e-ther, 1,4-bis(β,γ-epoxypropoxy) b utane, 1,6-bis(β,γ-epoxypropoxy)hexane, 1,4-bis(β,γ- epoxypropoxy)benzene, 1-(β,γ-epoxypropoxy)-2-ethoxy e thane, 1-(β,γ-epoxypropoxy)-2-benzyloxyethane, 2,2-bis -[р-(β,γ-epoxypropoxy)phenyl]propane and 2,2-bis-(4 -hydroxyphenyl)propane and 2,2-bis-(4-hydroxyphenyl)methane, etc. Bisglycidyl polyethers obtained by the reaction of bisphenols such as with epichlorohydrin can be mentioned, and these can be used alone or in combination of two or more.

[0095] As the above 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-ox azoline), 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-cyclohexyl -2-oxazoline), 2,2'-bis(4-benzyl-2-oxazoline), 2,2'- p-phenylenebis(2-oxazoline), 2,2'-m-phenylenebis(2-oxa zoline), 2,2'-o-phenylenebis(2-oxazoline), 2,2'-p-phenylene bis(4-methyl-2-oxazoline), 2,2'-p-phenylenebis(4,4-di methyl-2-oxazoline), 2,2'-m-phenylenebis(4-methyl-2-oxa zoline), 2,2'-m-phenylenebis(4,4-dimethyl-2-oxazoline), 2 ,2'-ethylenebis(2-oxazoline), 2,2'-tetramethylenebis(2-oxa zoline), 2,2'-hexamethylenebis(2-oxazoline), 2,2'-octamethylene bis(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'-diphenoxyethanebis( 2-oxazoline), 2,2'-cyclohexylenebis(2-oxazoline), 2,2'- diphenylenebis(2-oxazoline) and the like can be exemplified, and among these, 2 ,2'-bis(2-oxazoline) is most preferred from the viewpoint of reactivity with the polyester resin (A). These can be used alone or in combination of two or more.

[0096] As these hydrolysis inhibitors (C), those with low volatility are preferred. For this reason, it is preferable to use those with a high number-average molecular weight, and usually, it is 300 to 10,000, preferably 100 0 to 5,000. Also, as the hydrolysis inhibitor (C), those with a high weight-average molecular weight are preferably used from the viewpoint of hydrolysis resistance. The weight-average molecular weight of the hydrolysis inhibitor (C) is preferably 500 or more, more preferably 1,000 or more, still more preferably 2,000 or more, and particularly preferably 3,000 or more. The upper limit of the weight-average molecular weight is usually 50,000. 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. .

[0097] Among the hydrolysis inhibitors (C), it is preferable to use a carbodiimide group-containing compound. In this case, the carbodiimide equivalent is preferably 50 to 10,000, particularly 100 to 1,000, and more preferably 150 to 500. The carbodiimide equivalent represents the chemical formula weight per one carbodiimide group.

[0098] The content of the hydrolysis inhibitor (C) is preferably 0.01 to 10 parts by weight, particularly preferably 0.1 to 5 parts by weight , more preferably 0.2 to 3 parts by weight, based on 100 parts by weight of the polyester resin (A). If the content is too large, turbidity tends to occur due to poor compatibility with the polyester resin (A), and if it is too small, sufficient durability tends to be difficult to obtain.

[0099] Also, the content of the hydrolysis inhibitor (C) is preferably optimized according to the acid value of the polyester resin (A). The molar ratio [(y) / (x)] of the total number of moles (y) of the functional groups of the hydrolysis inhibitor (C) in the polyester-based pressure-sensitive adhesive composition to the total number of moles (x) of the acidic functional groups of the polyester resin (A) in the polyester-based pressure-sensitive adhesive composition is preferably 0.5 ≦ (y) / (x), 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 wet heat resistance performance tends to decrease. Incidentally , if the molar ratio of (y) to (x) is too high, the compatibility with the polyester resin (A) tends to decrease, and the adhesive strength, cohesive strength, and durability performance tend to decrease. (x)

[0100] <Crosslinking agent (D)> The polyester-based pressure-sensitive adhesive composition of the present invention preferably further contains a crosslinking agent (D). By containing the crosslinking agent (D), the polyester resin (A) can be crosslinked with the crosslinking agent (D) to obtain excellent cohesive strength and improve the performance as an adhesive.

[0101] Examples of such a crosslinking agent (D) include polyisocyanate-based compounds and polyepoxy-based ​​​Compounds and the like having a functional group that reacts with at least one of the hydroxyl groups and carboxyl groups contained in the polyester resin (A) are exemplified. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds.

[0102] Examples of such polyisocyanate compounds include tolylene diisocyanate compounds such as 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, xylylene diisocyanate compounds such as 1,3-xylylene diisocyanate, diphenylmethane compounds such as diphenylmethane-4,4-diisocyanate, naphthalene diisocyanate compounds such as 1,5-naphthalene diisocyanate, and other aromatic isocyanate compounds; alicyclic isocyanate compounds such as isophorone diisocyanate, 1,4-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, methylcyclohexane diisocyanate, isopropylidene dicyclohexyl-4,4'-diisocyanate, 1,3-diisocyanatomethylcyclohexane, norbornane diisocyanate; aliphatic isocyanate compounds such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; and adducts, burettes, isocyanurates, etc. of the above isocyanate compounds. In addition, the above polyisocyanate compounds can also be used in the form of those in which the isocyanate moiety is blocked with phenol, lactam, etc. These polyvalent isocyanate compounds may be used alone or in combination of two or more. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds. Among these, from the viewpoint of achieving a good balance between initial adhesiveness, mechanical strength, and heat resistance, it is particularly preferable to use polyisocyanate compounds.

[0103] The content of such a crosslinking agent (D) can be appropriately selected according to the molecular weight and application purpose of the polyester resin (A). Usually, for at least one equivalent of the hydroxyl group and carboxyl group contained in the polyester resin (A), the reactive group contained in the crosslinking agent (D) is preferably contained in the crosslinking agent (D) at a ratio of 0.2 to 10 equivalents, particularly preferably 0.5 to 5 equivalents, more preferably 0.5 to 3 equivalents, and even more preferably 0.5 to 1.5 equivalents. When the equivalent number of the reactive group contained in such a crosslinking agent (D) is too small, the cohesive force tends to decrease. When it is too large, the flexibility tends to decrease.

[0104] The content of such a crosslinking agent (D) is preferably contained in the crosslinking agent (D) at a ratio of 0 .1 to 20 parts by weight with respect to 100 parts by weight of the polyester resin (A), particularly preferably 0.2 to 15 parts by weight, more preferably 0.3 to 10 parts by weight, even more preferably 0.5 to 5 parts by weight, and particularly preferably 1 to 3 parts by weight. When the content of such a crosslinking agent (D) is too small, the cohesive force tends to decrease. When it is too large, the flexibility tends to decrease.

[0105] In the reaction between the polyester resin (A) and the crosslinking agent (D), an organic solvent having no functional group reactive with these (A) and (D) components, for example, esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, and aromatics such as toluene and xylene can be used. These can be used alone or in combination of two or more.

[0106] <Urethane-forming catalyst (E)> The polyester-based pressure-sensitive adhesive composition of the present invention preferably contains a urethanization catalyst (E) from the viewpoint of reaction rate. It is more preferable to have it.

[0107] Examples of the urethanization catalyst (E) include organometallic compounds and tertiary amine compounds. These can be used alone or in combination of two or more.

[0108] Examples of the above-mentioned organometallic compounds include zirconium-based compounds, iron-based compounds, tin-based compounds, titanium-based compounds, lead-based compounds, cobalt-based compounds, zinc-based compounds, etc. Examples of the zirconium-based compounds include zirconium naphthenate, zirconium acetylacetonate, etc. It can be mentioned. Examples of the iron-based compounds include iron acetylacetonate, iron 2-ethylhexanoate, etc. It can be mentioned. Examples of the tin-based compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dilaurate, etc. It can be mentioned. Examples of the titanium-based compounds include dibutyltitanium dichloride, tetrabutyl titanate, butoxytitanium trichloride, etc. It can be mentioned. Examples of the lead-based compounds include lead oleate, lead 2-ethylhexanoate, lead benzoate, lead naphthenate, etc. It can be mentioned. Examples of the cobalt-based compounds include cobalt 2-ethylhexanoate, cobalt benzoate, etc. It can be mentioned. Examples of the zinc-based compounds include zinc naphthenate, zinc 2-ethylhexanoate, etc. It can be mentioned. Examples of the above-mentioned tertiary amine compounds include triethylamine, triethylenediamine, etc. It can be mentioned.

[0109] Also, examples of the above-mentioned tertiary amine compounds include triethylamine, triethylenediamine, etc. Examples include min, 1,8-diazabicyclo-(5,4,0)-undecene-7, etc.

[0110] Among these urethanization catalysts (E), in terms of reaction rate and pot life of the adhesive layer, organometallic compounds are preferred, and zirconium-based compounds are particularly preferred. Furthermore, for urethanization catalyst (E), it is preferable to use acetylacetone in combination as a catalyst action inhibitor. Acetyl By containing acetone, the catalytic action at low temperatures is suppressed, which is preferable in terms of increasing the pot life.

[0111] In the polyester-based adhesive composition of the present invention, in addition to the above polyester-based resin (A), petroleum resin-based tackifier (B), hydrolysis inhibitor (C), crosslinking agent (D), urethanization catalyst (E), other additives such as hindered phenols and the like antioxidants, softeners, ultraviolet absorbers, stabilizers, antistatic agents, tackifiers other than the petroleum resin-based tackifier (B ), and other additives such as inorganic or organic fillers, metal powders, pigments, etc. powdery, particulate additives, etc. can be blended. These can be used alone or in combination of two or more.

[0112] The polyester-based adhesive according to the present invention is obtained by crosslinking the above polyester-based adhesive composition.

[0113] And the adhesive sheet of the present invention has an adhesive layer containing the above polyester-based adhesive, and such an adhesive layer is preferably formed on one or both sides of the support substrate. In the present invention, "sheet" is described to include "film" and "tape" as well. ​​​​​

[0114] <Adhesive sheet> The adhesive sheet can be produced, for example, as follows. As a method for manufacturing such an adhesive sheet, it can be manufactured according to a known general method for manufacturing an adhesive sheet. For example, the above polyester-based adhesive composition is applied and dried on a base material, a release sheet is laminated on the adhesive layer surface on the opposite side, and if necessary, cured, whereby an adhesive sheet having a base material and an adhesive layer containing a polyester-based adhesive, wherein the adhesive layer is provided on at least one surface of the base material, is obtained.

[0115] Alternatively, the polyester-based adhesive composition is applied and dried on a release sheet, and a base material is laminated on the adhesive layer surface on the opposite side, and if necessary, cured, whereby the adhesive sheet of the present invention can also be obtained.

[0116] Further, an adhesive layer is formed on a release sheet, and a release sheet is laminated on the adhesive layer surface on the opposite side, whereby an adhesive sheet having an adhesive layer containing a polyester-based adhesive and no base material, i.e., a base material-less type of adhesive sheet, can be manufactured.

[0117] When using the obtained adhesive sheet or base material-less type of adhesive sheet, the release sheet is peeled off from the adhesive layer during use, and the adhesive layer is laminated on an adherend.

[0118] Examples of the base material include polyester-based resins such as polyethylene naphthalate, polyethylene terephthalate, polybutylene terephthalate, and polyethylene terephthalate / isophthalate copolymer; polyolefin-based resins such as polyethylene, polypropylene, and polymethylpentene; and fluorine-containing resins such as polyvinyl fluoride, polyvinylidene fluoride, and polyvinyl fluoride. ​​ Ethylene tetrafluoride resin; polyamides such as nylon 6 and nylon 6,6; polyvinyl chloride, polyvinyl chloride / vinyl acetate copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, vinyl polymers such as polyvinyl alcohol and vinylon; triacetate cell ulose, cellulose-based resins such as cellophane; polymethyl methacrylate, polymethacrylic acid ethyl, acrylic resins such as polyethyl acrylate and polybutyl acrylate; polystyrene ; polycarbonate; polyarylate; polyimide; a sheet made of at least one synthetic resin selected from the group consisting of cycloolefin polymers, etc.; metal foils of aluminum, copper, and iron ; papers such as high-quality paper and glassine paper; woven fabrics and non-woven fabrics made of glass fibers, natural fibers, synthetic fibers, etc. These substrates can be used as a single layer or as a multi-layer body in which two or more layers are laminated.

[0119] Among these, substrates made of polyethylene terephthalate and polyimide are particularly preferred, and polyethylene terephthalate is particularly preferred in terms of excellent adhesion to the adhesive.

[0120] In addition, as the above substrate, a foam substrate, for example, a foam sheet made of a foam of a synthetic resin such as polyurethane foam, polyethylene foam, and polyacrylate foam can be used. Among these, polyethylene foam and polyacrylate foam are preferred in terms of excellent followability to the adherend and balance of adhesive strength.

[0121] The thickness of the above substrate is preferably, for example, 1 to 1000 μm, particularly preferably 2 to 500 μm, and even more preferably 3 to 300 μm. ​​​​​

[0122] As the release sheet, for example, a sheet made of various synthetic resins exemplified by the above base material, paper, cloth, non-woven fabric, etc. that have been subjected to a release treatment can be used. As the release sheet, a silicone-based release sheet is preferably used.

[0123] As the coating method of the above polyester-based pressure-sensitive adhesive composition, for example, a gravure roll coater -er, reverse roll coater, kiss roll coater, dip roll coater, bar coater -er, knife coater, spray coater, comma coater, etc. may be used.

[0124] As the conditions for the aging treatment, the temperature is usually room temperature (23°C) to 70°C, and the time is usually 1 to 30 days. Specifically, for example, it can be carried out under conditions such as 1 to 20 days at 23°C, preferably 3 to 1 4 days, 1 to 10 days at 40°C, etc.

[0125] Also, as the drying conditions, the drying temperature is preferably 60 to 140°C, particularly preferably 80 to 120°C, and the drying time is preferably 0.5 to 30 minutes, particularly preferably 1 to 5 minutes. There is.

[0126] The thickness of the adhesive layer of the above pressure-sensitive adhesive sheet and the substrate-less double-sided pressure-sensitive adhesive sheet is preferably 2 to 500 μm Particularly preferably 5 to 200 μm, more preferably 10 to 100 μm. If the thickness of such an adhesive layer is too thin, the adhesive strength tends to decrease. If it is too thick, it becomes difficult to coat uniformly, and there is a tendency for problems such as air bubbles to enter the coating film to occur easily. In addition, when considering the shock absorbency, it is preferably 50 μm or more. There is.

[0127] Incidentally, the thickness of the above adhesive layer is measured using "ID-C112B" manufactured by Mitutoyo Corporation, and the thickness of the components other than the adhesive layer is subtracted from the measured value of the total thickness of the adhesive sheet. to obtain the thickness of the adhesive layer.

[0128] The gel fraction of the adhesive layer of the above adhesive sheet is preferably 5% by weight or more, particularly preferably 6 to 80% by weight, more preferably 7 to 60% by weight, still more preferably 10 to 40% by weight, particularly preferably 15 to 35% by weight, and most preferably 20 to 30% by weight, from the viewpoints of durability performance and adhesive strength. If the gel fraction is too low, the cohesive force decreases, and the holding force tends to decrease. If the gel fraction is too high, the adhesive strength tends to decrease due to the increase in the cohesive force.

[0129] The above gel fraction serves as a measure of the degree of crosslinking and is calculated, for example, by the following method. That is, an adhesive sheet (one without a release sheet) in which an adhesive layer is formed on a polymer sheet serving as a base material (for example, a PET film or the like) is wrapped with a 200-mesh SUS wire mesh and immersed in toluene at 23°C for 24 hours. The weight percentage of the insoluble adhesive component remaining in the wire mesh after immersion with respect to the weight of the adhesive component before immersion is defined as the gel fraction. However, the weight of the base material is subtracted.

[0130] Furthermore, such an adhesive sheet may be provided with a release sheet on the outside of the adhesive layer for protection as needed. Also, in an adhesive sheet in which the adhesive layer is formed on one side of the base material, by performing a peeling treatment on the surface of the base material opposite to the adhesive layer, it is also possible to protect the adhesive layer using the peeled surface.

[0131] The polyester-based pressure-sensitive adhesive of the present invention can be used for bonding various members. In particular, single-sided or double-sided adhesive sheets used for bonding optical components, and parts of portable electronic devices It is used as a single-sided or double-sided adhesive sheet for fixing materials and electronic materials. EXAMPLES

[0132] The present invention will be described 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. In the examples, "parts" and "%" indicate All values ​​are by weight unless otherwise specified. In addition, the glass transition temperature, number average molecular weight, and the like of the polyester resin (A) in the following examples are The amount, weight average molecular weight, acid value, hydroxyl value, ester bond concentration, and heat of fusion of crystals are as described above. The method was used to calculate the

[0133] Prior to the examples, the following components were prepared.

[0134] [Production of polyester resin] The structural unit ratio derived from the finished component of the polyvalent carboxylic acids described in the following manufacturing examples (hereinafter, The mole percentage of the "finished component ratio" is calculated by dividing the total amount of polycarboxylic acids by 10 The molar ratio is shown assuming 0 mol %. In addition, the mole percentages of the components in the final polyols described in the following production examples are the same as those in the polyols. The molar ratio is shown when the total amount of the above is taken as 100 mol %.

[0135] [Polyester resin (A-1)] A reactor equipped with a heater, thermometer, stirrer, rectification column, nitrogen inlet tube and vacuum device is installed. As the divalent carboxylic acid (a1), 94.6 parts of isophthalic acid (IPA) (a1-1-1) 0 mol% and 460.8 parts (80 mol%) of sebacic acid (SebA), polyol (a 2) as 1,4-butanediol (1.4BG) (a2-3) 128.3 parts (50 mol %), neopentyl glycol (NPG) (a2-2) 296.6 parts (100 mol%), trimethylolpropane (TMP) 5.7 parts (1.5 mol%), and hydrogenated polybutadie ne polyol (a2-1) (manufactured by Nippon Catalyst Co., Ltd., "GI-1000") 14 parts (0.3 mol% ), 0.05 part of zinc acetate was charged as a catalyst, the temperature was gradually raised to 250 °C, and the esterification reaction was carried out over 4 hours . Then, the temperature was raised to 260 °C, 0.05 part of tetrabutyl titanate was charged as a catalyst, the pressure was reduced to 1.33 hPa, and the polymerization reaction was carried out over 3 hours , and polyester resin (A-1) was produced . The resulting component ratio of polyester resin (A-1) was isophthalic acid / sebacic acid = 20 mol% / 80 mol% as polycarboxylic acids (a 1), and 1,4-butanediol / neopentyl glycol / trimethylolpropane / hydrogenated polybutadiene polyol = 33.7 mol% / 64.5 mol% / 1.5 mol% / 0.3 mol as polyol (a2) %, and the physical properties were as shown in Table 1 . Also, the content of the structural unit derived from the hydrogenated polybutadiene structure-containing compound in polyester resin (A-1) was 1.7% by weight, and the heat of crystal melting was 0 J / g .

[0136] [[Adhesive imparting agent (B), (B')]] (B-1): Copolymer of styrene monomer and aliphatic monomer (number average molecular weight (Mn) 860, weight average molecular weight (Mw) 1210, glass transition temperature (Tg) 30 °C, softening point 95 °C, acid value less than 1 mg KOH / g, salicylic acid value less than 1 mg KOH / g (manufactured by Mitsui Chemicals, "FT R-6100") (B-2): Copolymer of styrene-based monomer and aliphatic monomer (number average molecular weight (Mn) 1150, weight average molecular weight (Mw) 1950, glass transition temperature (Tg) 65 °C, softening point 1 25 °C, acid value less than 1 mg KOH / g, salicylic acid value less than 1 mg KOH / g (manufactured by Mitsui Chemicals, " FTR-6125") (B-3): Copolymer of styrene-based monomer (number average molecular weight (Mn) 820, weight average molecular weight (Mw) 1240, glass transition temperature (Tg) 35 °C, softening point 100 °C, acid value 1 mg K OH / g less than, salicylic acid value less than 1 mg KOH / g (manufactured by Mitsui Chemicals, "FTR-8100") (B'-1): Terpene phenol-based tackifier (number average molecular weight (Mn) 500, softening point 80 °C, acid value less than 1 mg KOH / g, salicylic acid value 70 mg KOH / g (manufactured by Yasuhara Chemical Co., Ltd., "T80") (B'-2): Aliphatic monomer copolymer (number average molecular weight (Mn) 370, weight average molecular weight (Mw) 500, glass transition temperature (Tg) -31 °C, softening point 10 °C, acid value 1 mg KOH / g less than, salicylic acid value less than 1 mg KOH / g (manufactured by Kray Valley Co., Ltd., "Wingtack10 ")

[0137] [Hydrolysis inhibitor (C)] (C-1): Polyvalent carbodiimide compound (manufactured by Nisshinbo Chemicals Co., Ltd., "Carbodilite V-0 9GB, solid content concentration 70%")

[0138] [Crosslinking agent (D)] (D-1): Trimethylolpropane / toluene diisocyanate adduct (manufactured by Tosoh Corporation, "Coronate L55E, solid content concentration 55%")

[0139] [Urethane-forming 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") (Examples 1 to 4, Comparative Examples 1 to 6)

[0140] (Examples 1 to 4, Comparative Examples 1 to 6) The polyester resin (A) obtained above was diluted with ethyl acetate to a solid content concentration of 50%, and to this polyester resin (A) (100 parts as solid content), tackifier (B) or (B’), hydrolysis inhibitor (C), crosslinking agent (D), and urethane-forming catalyst (E) were blended in the compositions shown in Table 2 (by solid content ratio), and stirred and mixed to obtain a polyester-based pressure-sensitive adhesive composition. Using the polyester-based pressure-sensitive adhesive compositions obtained in the above Examples and Comparative Examples, a pressure-sensitive adhesive sheet was produced as follows and evaluated as follows. Also, the gel fraction of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet was determined according to the method described above.

[0141] [Production of Pressure-Sensitive Adhesive Sheet with Single-Sided Release Film] The polyester-based pressure-sensitive adhesive compositions obtained in the Examples and Comparative Examples were applied onto a PET film (thickness: 38 μm, manufactured by Toray Industries, Inc., "Lumirror T60") using an applicator, and dried at 100°C for 3 minutes to obtain a pressure-sensitive adhesive sheet with a PET film having a pressure-sensitive adhesive layer thickness of 25 μm. Next, the surface of the pressure-sensitive adhesive layer of the obtained pressure-sensitive adhesive sheet with a PET film was covered with a PE T release film (thickness: 38 μm, manufactured by Mitsui Chemicals Toagosei Co., Ltd., SP-PET-01-BU), and aged at 40°C for 4 days to obtain a pressure-sensitive adhesive sheet with a single-sided release film.

[0142] [Evaluation of Pressure-Sensitive Adhesive Sheet] [Adhesive Strength] ​​The pressure-sensitive adhesive sheet with a single-sided release film obtained above was placed in an environment of 23°C and 50% RH for 2 After cutting it into a size of 5 mm × 200 mm, the release film was peeled off, and the adhesive layer side was attached to each of (1 ) a mirror-finished stainless steel plate (SUS-BA plate), (2) a PET film lined with a SUS-BA plate, and (3) a polyethylene plate (PE) by reciprocating a 2-kg roller twice and pressing it. After standing still for 30 minutes in the same atmosphere, an autograph (manufactured by Shimadzu Corporation, " Autograph AG-X 50N") was used to measure the peel strength (N / 25 mm) at a peel rate of 300 mm / min at 180 degrees. The evaluation criteria are as follows. The evaluation criteria are as follows. ○ ··· Greater than 10 N / 25 mm (Evaluation criteria) ○ ··· Greater than 10 N / 25 mm △ ··· Greater than 5 N / 25 mm and less than or equal to 10 N / 25 mm × ··· Less than or equal to 5 N / 25 mm

[0143] [Retention force] The pressure-sensitive adhesive sheet with a single-sided release film obtained above was placed in an environment of 23°C and 50% RH for 2 After cutting it into a size of 5 mm × 50 mm, the release film was peeled off, and a 2-kg roller was reciprocated twice and pressed onto a stainless steel plate (SU S304) (adhesive area: 25 mm × 25 mm). Then, a creep tester (manufactured by Tester Sangyo Co., Ltd., holding force tester with high-temperature and constant-humidity chamber BE-501) was used to measure the holding force by applying a load of 1 kg at 40°C for 24 hours. The evaluation criteria are as follows . The evaluation criteria are as follows. (Evaluation criteria) 〇 ··· No displacement △ ··· Displacement is 1.0 mm or less × ··· Displacement greater than 1.0 mm or falling off

[0144] [Tackiness] The pressure-sensitive adhesive sheet with a single-sided release film obtained above was placed in an environment of 23°C and 50% RH for 2 Cut to a size of 5 mm × 100 mm and use an inclined ball tack tester. At an angle of 30° After installation, peel off the release film, and roll 32 types of bare ring balls with diameters ranging from 1 / 32 inch to 1 inch for a sliding distance of 100 mm, and the maximum No. of the balls that remained on the adhesive surface for 30 seconds or more was taken as the ball tack value. The evaluation criteria are as follows. (Evaluation criteria) 〇 ··· Ball No. 9 or above △ ··· Ball No. 7 - 8 × ··· Ball No. 6 or below

[0145]

Table 1

[0146]

Table 2

[0147] From the results of Table 2 above, it can be seen that the pressure-sensitive adhesive sheets obtained from the pressure-sensitive adhesive compositions of Examples 1 to 4 using polyester resin (A) and petroleum resin-based tackifying resin (B) having a specific number-average molecular weight at a specific content ratio are excellent in all of adhesive strength, holding power, and tackiness. On the other hand, the pressure-sensitive adhesive sheet obtained from the pressure-sensitive adhesive composition of Comparative Example 1 that does not use petroleum resin-based tackifying resin (B) having a specific number-average molecular weight has holding power, but is inferior in terms of adhesive strength and tackiness. Also, in the pressure-sensitive adhesive sheet obtained from the pressure-sensitive adhesive composition of Comparative Example 2 that uses a large amount of petroleum resin-based tackifying resin (B) having a specific number-average molecular weight, it is inferior in all of adhesive strength, holding power, and ball tack. ​​​​There were. And, the polyester adhesives of Comparative Examples 3 to 4 using terpene-based tackifier resins Although the pressure-sensitive adhesive sheet obtained from the composition has holding power, it is inferior in adhesive strength and tack There was. Furthermore, for Comparative Examples 5 to 6 using petroleum resin-based tackifier resins having a small number average molecular weight Regarding the pressure-sensitive adhesive sheet obtained from the polyester-based pressure-sensitive adhesive composition, although it is excellent in holding power It was inferior in adhesive strength and tack. From this, it can also be seen that the polyester resin (A) and a petroleum resin-based tackifier resin (B) having a specific number average molecular weight in a specific ratio It can be seen that the polyester-based pressure-sensitive adhesive composition containing it is excellent in adhesive properties .

Industrial Applicability

[0148] The polyester-based pressure-sensitive adhesive composition of the present invention is excellent in adhesive strength, holding power, and tack Therefore, the polyester-based pressure-sensitive adhesive and pressure-sensitive adhesive sheet using it can be suitably used for bonding applications such as electronic members, optical Members and building members.

Claims

1. A structural unit derived from a polyvalent carboxylic acid (a1) and a structural unit derived from a polyol (a2) and a petroleum resin-based viscoelastic having a number average molecular weight of 400 to 8,000. A petroleum resin-based tackifier containing a tackifier (B) and having a number average molecular weight of 400 to 8,000. The content of (B) is 0.01 to 50 parts by weight per 100 parts by weight of the polyester resin (A).

2. A polyester-based pressure-sensitive adhesive composition comprising:

2. 2. The method according to claim 1, wherein the petroleum resin-based tackifier (B) has an aromatic ring structure. The polyester-based pressure-sensitive adhesive composition.

3. The softening point of the petroleum resin-based tackifier (B) is 30 to 200° C. The polyester-based pressure-sensitive adhesive composition according to claim 1 or 2.

4. The petroleum resin-based tackifier (B) has an acid value of 5 mgKOH / g or less. The pressure-sensitive adhesive composition according to any one of claims 1 to 3.

5. The polyester resin (A) has a glass transition temperature of -80 to 20°C. The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 4.

6. The ester bond concentration of the polyester resin (A) is 3 to 9 mmol / g. The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 5,

7. 7. The composition according to claim 1, further comprising a hydrolysis inhibitor (C). Item 1. The polyester-based pressure-sensitive adhesive composition according to item 1.

8. The composition according to any one of claims 1 to 7, further comprising a crosslinking agent (D). A polyester-based pressure-sensitive adhesive composition.

9. The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 8 is crosslinked. A polyester-based adhesive characterized by:

10. A pressure-sensitive adhesive comprising a pressure-sensitive adhesive layer containing the polyester-based pressure-sensitive adhesive according to claim 9. Arrival seat.

11. A pressure-sensitive adhesive sheet having a substrate and a pressure-sensitive adhesive layer containing the polyester-based pressure-sensitive adhesive according to claim 9. The pressure-sensitive adhesive layer is provided on at least one surface of the substrate. Adhesive sheet.

12. A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer containing the polyester-based pressure-sensitive adhesive according to claim 9. The pressure-sensitive adhesive sheet is characterized by being a substrate-less type having no substrate.

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