Polyester-based pressure-sensitive adhesive composition, pressure-sensitive adhesive, pressure-sensitive adhesive sheet, and optical member with pressure-sensitive adhesive layer

Abstract

To provide a polyester-based adhesive composition which causes less yellowing and has excellent ultraviolet absorbency while having excellent adhesive strength and substrate adhesiveness, an adhesive, an adhesive sheet, and an optical member with an adhesive layer.SOLUTION: A polyester-based adhesive composition comprises a polyester-based resin [I] containing a structural unit derived from a polycarboxylic acid (A) and a structural unit derived from a polyol (B) and an ultraviolet absorber [II], wherein the ultraviolet absorber (II) is an ultraviolet absorber having a hydroxyl value of 900 mgKOH / g or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a polyester-based pressure-sensitive adhesive composition, a pressure-sensitive adhesive, a pressure-sensitive adhesive sheet, and a light-emitting device with a pressure-sensitive adhesive layer. More specifically, regarding optical materials, it has excellent adhesive strength and adhesion to substrates, and is less prone to yellowing and is resistant to ultraviolet rays. Polyester-based pressure-sensitive adhesive composition having excellent radiation absorption ability, pressure-sensitive adhesive, pressure-sensitive adhesive sheet, and pressure-sensitive adhesive layer This relates to optical members. [Background technology]

[0002] Plasma display (PDP), liquid crystal display (LCD), organic EL display OLED, Electrophoretic Display (EPD), Interferometric Modulation Display (IMOD) Such image display devices are composed of various members, and such image display device components In order to bond and integrate the materials, adhesives or adhesive sheets are used. For example, For touch panel displays, surface protection panels, touch panels, image display panels, etc. The image display device components are used, and when these components are laminated, an adhesive or Adhesive sheets are used.

[0003] For example, Patent Document 1 discloses a surface protection layer or a touch panel in an image display device and an image A transparent adhesive sheet for attaching the display surface of the display unit, or a surface protection layer and a touch panel (A) a (meth) alkyl group having 4 to 18 carbon atoms; (B) Alkyl acrylate, homopolymer having a glass transition temperature (Tg) of 50°C or less and (C) a (meth)acrylic acid ester having a specific formula: Or contains a hydrophilic monomer whose homopolymer has a glass transition temperature (Tg) of 10°C or less It contains a copolymer of monomers and has a tan δ of 0.13 or more at 140°C and 1.0 Hz. The storage modulus at 25°C and 1.0 Hz is 8.9 × 10 4 Pa or less, transparent Adhesive sheets have been proposed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-163591 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology disclosed in Patent Document 1 and the adhesives that have been studied so far are acrylic. These acrylic adhesives contain acrylic resins. Since the fat itself is soft, improvements are required in terms of impact resistance. Designing acrylic resins to be too hard would result in reduced adhesive strength and poor adhesion to substrates.

[0006] In recent years, with the trend towards lighter and thinner displays, touch panels are being installed inside LCD pixels. In addition to the in-cell method, which incorporates the panel electrodes, Touch panels that are obtained by lamination, such as the on-cell method, which provides touch panel functions by providing electrodes, The touch-on lens system is a system in which the panel functions are directly integrated into the LCD module ("touch-on lens system"). While new cell types such as in-cell, on-cell, and tha-cell have been proposed, In the touch-on lens system, a single adhesive material is used to bond the surface protection panel and the LCD The functions required for attaching the surface protection panel to the LCD module are also included. The functions required for adhesion to a substrate must be achieved with a single adhesive sheet or adhesive. In particular, display module manufacturers are looking for touch panels. In addition to the above, the light emitted by functional films such as polarizing films and retardation films is also The number of components can be reduced as much as possible by directly incorporating the optical functions into the LCD module or other components. It is expected that the simplification of the functional layers of these functional films and changes in module configuration will The pressure-sensitive adhesive sheet is also required to have ultraviolet ray blocking properties in order to protect these functional layers.

[0007] In this invention, therefore, in this context, we have developed a method for producing a tackifier that can replace acrylic resins. Made of polyester resin, it has excellent adhesion and substrate adhesion, and is less prone to yellowing and has excellent UV absorption. The object of the present invention is to provide a polyester-based pressure-sensitive adhesive composition having excellent yield. In addition, it is an object of the present invention to provide a pressure-sensitive adhesive, a pressure-sensitive adhesive sheet, and an optical member with a pressure-sensitive adhesive layer. [Means for solving the problem]

[0008] However, the present inventors have conducted extensive research in light of the above circumstances and have found that polyester resins In the pressure-sensitive adhesive composition containing the above, by adding an ultraviolet absorber having a small hydroxyl value, It has excellent adhesion, adhesion to substrates, and is also less prone to yellowing. It has excellent UV absorption properties. The present inventors have found that a vinyl-based pressure-sensitive adhesive composition can be obtained by the above-mentioned method, and have completed the present invention.

[0009] That is, the present invention relates to a polyol having a structural unit derived from a polyvalent carboxylic acid (A) and a structural unit derived from a polyol (B). and an ultraviolet absorber [II], The ultraviolet absorber [II] is an ultraviolet absorber having a hydroxyl value of 900 mgKOH / g or less. A first aspect relates to an ester-based pressure-sensitive adhesive composition.

[0010] The present invention also provides a pressure-sensitive adhesive obtained by crosslinking the polyester-based pressure-sensitive adhesive composition, comprising: The present invention relates to a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive, and and an optical member having a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive. A fourth aspect of the present invention is an optical member with a pressure-sensitive adhesive layer.

[0011] In the present invention, the ultraviolet absorbing agent contained in the polyester resin is an ultraviolet absorbing However, not just any agent will do, but ultraviolet absorbing agents with a low hydroxyl value are preferred. It has been found that it is effective in combination with polyester resins. If so, such an ultraviolet absorber contains a hydroxyl group in that it has excellent ultraviolet absorbing performance in the long wavelength region. Although UV absorbents with high hydroxyl values ​​are often used, UV absorbents with low hydroxyl values ​​are used. By blending ultraviolet ray absorbing agents, it is surprisingly possible to absorb ultraviolet rays in the long wavelength range without compromising adhesive strength. The present invention has been achieved by using a polyester resin having excellent absorbency and excellent resistance to yellowing. be. Effect of the Invention

[0012] The polyester-based pressure-sensitive adhesive composition of the present invention comprises a structural unit derived from a polyvalent carboxylic acid (A) and a polyester. A polyester resin [I] containing a structural unit derived from thiol (B), and an ultraviolet absorber [ The ultraviolet absorber [II] is an ultraviolet absorbent having a hydroxyl value of 900 mgKOH / g or less. Therefore, it has excellent adhesion and substrate adhesion, little yellowing, and UV absorption. It has excellent yield properties and is particularly useful as an adhesive for optical members. . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The configuration of the present invention will be described in detail below, but these are examples of preferred embodiments. It is something. In the present invention, the term "carboxylic acids" refers to carboxylic acids as well as carboxylates, carboxylates, and the like. Carboxylic acid derivatives such as carboxylic acid anhydrides, carboxylic acid halides, and carboxylic acid esters are also available. It includes.

[0014] The polyester-based pressure-sensitive adhesive composition of the present invention (hereinafter sometimes referred to as "pressure-sensitive adhesive composition") is The present invention is characterized by containing a polyester resin [I] and a specific ultraviolet absorber [II]. The pressure-sensitive adhesive composition of the present invention comprises the polyester resin [I] and a specific purple polymer. The essential component is an ultraviolet ray absorber [II], and the components are a hydrolysis inhibitor [III] and a crosslinking agent [IV]. It is preferable that the composition contains at least one of the hydrolysis inhibitor [III] and the crosslinking agent [IV It is more preferable that the compound contains both of the above. Each of the components constituting the pressure-sensitive adhesive composition of the present invention will be described below in order.

[0015] <Polyester resin [I]> The polyester resin [I] is usually made of polyvalent carboxylic acids (A) and and a copolymerization component containing a polyol (B), The resin composition of the resin [I] is a structural unit derived from a polyvalent carboxylic acid (A), The polyol (B) has structural units derived therefrom.

[0016] [Polyvalent carboxylic acids (A)] The polyvalent carboxylic acids (A) used as raw materials for the polyester resin [I] Examples of the carboxylic acid include divalent carboxylic acids and trivalent or higher polyvalent carboxylic acids. Divalent carboxylic acids are preferably used since the tere resin [I] can be stably obtained.

[0017] Examples of the divalent carboxylic acids include malonic acids, dimethylmalonic acids, and succinic acid. , glutaric acids, adipic acids, trimethyladipic acids, pimelic acids, 2,2-di Methylglutaric acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, ita Conical acids, thiodipropionic acids, diglycolic acids, 1,9-nonanedicarboxylic acids, etc. aliphatic dicarboxylic acids; Phthalic acids, terephthalic acids, isophthalic acids, benzylmalonic acids, diphenic acids, 4,4'-oxydibenzoic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, Phthalenedicarboxylic acids, naphthalenedicarboxylic acids such as 2,7-naphthalenedicarboxylic acids Aromatic dicarboxylic acids such as acids; 1,3-Cyclopentanedicarboxylic acids, 1,2-Cyclohexanedicarboxylic acids, 1 ,3-Cyclopentanedicarboxylic acids, 1,4-Cyclohexanedicarboxylic acids, 2,5 Alicyclic dicarboxylic acids such as norbornanedicarboxylic acids and adamantanedicarboxylic acids ; etc. Examples of the trivalent or higher polyvalent carboxylic acids include trimellitic acids, pyrrolic acids, and the like. Examples of the acid include ric acids, adamantanetricarboxylic acids, and trimesic acids. These polyvalent carboxylic acids (A) may be used alone or in combination of two or more. .

[0018] Among the polyvalent carboxylic acids (A), those which reduce the crystallinity of the polyester resin [I] are preferred. From this viewpoint, aromatic polyvalent carboxylic acids, particularly asymmetric aromatic dicarboxylic acids (A-1) are preferred. As the asymmetric aromatic dicarboxylic acid (A-1), for example, Taric acids, isophthalic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids Carboxylic acids, 2,7-naphthalenedicarboxylic acids, etc. are examples. Of these, isophthalic acids are particularly preferred.

[0019] Such aromatic polycarboxylic acids, particularly asymmetric aromatic dicarboxylic acids (A-1), The content is preferably 1 to 90 mol % based on the total amount of the polyvalent carboxylic acids (A), In particular, it is preferably 5 to 80 mol %, more preferably 10 to 70 mol %, and especially The content is preferably 15 to 60 mol %, more preferably 20 to 50 mol %. If the amount is too small, the adhesive strength at high temperatures will decrease, the resin will crystallize, and the adhesive performance will be insufficient. If the amount is too large, the initial adhesive strength (tack) tends to decrease.

[0020] In the present invention, the polyvalent carboxylic acid (A) is used to improve the initial adhesive strength (tack). From the viewpoint of improving the chemical properties, aliphatic dicarboxylic acids having 4 or more carbon atoms (including the carbon atom of the carboxyl group) It is preferable to contain (A-2), and among these, adipic acid, azelaic acid, and sebacic acid are preferable. Contains aliphatic dicarboxylic acids with 6 to 12 carbon atoms (including the carbon of the carboxy group) such as is more preferred.

[0021] The content of the aliphatic dicarboxylic acids (A-2) having 4 or more carbon atoms is, for example, polyvalent carbo It is preferably 5 to 100 mol % based on the total amount of the carboxylic acids (A). It is preferably 95 mol %, particularly preferably 30 to 90 mol %, and further preferably The content is preferably 40 to 85 mol %, more preferably 50 to 80 mol %. If the content is too low, The glass transition temperature of the polyester resin [I] becomes too high, and sufficient adhesive strength cannot be obtained. If the content is too high, the adhesive strength at high temperatures may decrease and the resin may harden. It tends to crystallize and not provide sufficient adhesive performance.

[0022] In the present invention, from the viewpoint of adhesive properties, as the polyvalent carboxylic acid (A), an asymmetric aromatic aliphatic dicarboxylic acids (A-1), and aliphatic dicarboxylic acids (A-2) having 4 or more carbon atoms It is also preferable to use the asymmetric aromatic dicarboxylic acid (A-1) in combination. The content ratio (molar ratio) of the aliphatic dicarboxylic acid (A-2) having 4 or more carbon atoms is (A-1) / (A -2) is preferably 1 / 99 to 90 / 10, and particularly preferably 10 / 90 to 70 / 30, and more preferably 20 / 80 to 60 / 40.

[0023] In the present invention, in order to increase the branching points in the polyester resin [I], trivalent The above polyvalent carboxylic acids (A-3) can also be used. Among them, the polyvalent carboxylic acids (A-4) which tend to gel during production can be used. It is preferable to use trimellitic acids because they are less likely to undergo polymerization.

[0024] The content of the trivalent or higher polyvalent carboxylic acid (A-3) is as follows: In terms of increasing the cohesive strength, it is preferable to use 1 The content is preferably 0.0 mol % or less, particularly preferably 0.1 to 5 mol %, and if the content is too high, the poly The ester resin [I] tends to gel during production.

[0025] [Polyol (B)] The polyol (B) used as a constituent material of the polyester resin [I] is Examples of the polyol include trihydric alcohols and trihydric or higher polyols.

[0026] Examples of the dihydric alcohol include ethylene glycol, diethylene glycol, Triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol 2,4-Dimethyl-2-ethylhexane-1,3-diol, 2-methyl 2,2-dimethyl-1,3-propanediol (neopentyl-1,3-propanediol, 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, Aliphatic acids such as 5-pentanediol and 2,2,4-trimethyl-1,6-hexanediol Diol; 1,2-Cyclohexanedimethanol, 1,3-Cyclohexanedimethanol, 1,4 -Cyclohexanedimethanol, Spiroglycol, Tricyclodecanedimethanol, A Damantanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, etc. of alicyclic diols; 4,4'-Thiodiphenol, 4,4'-Methylenediphenol, 4,4'-Dihydroxy Sibiphenyl, o-, m-, and p-dihydroxybenzene, 2,5-naphthalene dithio p-Xylylenediol, p-Xylylenediol, and their ethylene oxide adducts and propylene diol and aromatic diols such as oxide adducts. In addition, fatty acid esters derived from castor oil, oleic acid, erucic acid, etc. Examples of such glycerol derivatives include dimer diol and glycerol monostearate. Examples of the trihydric or higher polyol include pentaerythritol, dipentaerythritol, and the like. Erythritol, Tripentaerythritol, Glycerin, Trimethylolpropane, Dimethylolethane, 1,2,4-butanetriol, 1,2,5-pentanetriol , 1,2,6-Hexanetriol, 1,3,6-Hexanetriol, Adamantanate Rioll, etc. The above polyols (B) can be used alone or in combination of two or more kinds.

[0027] In the present invention, the glass transition temperature (Tg) of the polyester resin [I] is lowered to obtain an initial In order to improve adhesive strength, a linear aliphatic diol (B-1) is added to polyol (B). It is preferable to contain an aliphatic diol having a straight chain structure and a carbon number of 2 to 18. Particularly preferred are ethylene glycol, 1,3-propanediol, and 1,4- Butanediol.

[0028] The content of the linear aliphatic diol (B-1) relative to the total polyol (B) is 1 It is preferably from 100 mol %, more preferably from 2 to 80 mol %, and particularly preferably from 3 to 70 mol %. The content is preferably 4 to 60 mol %, and more preferably 5 to 50 mol %. If the amount is too small, it tends to be difficult to obtain a stable resin formation.

[0029] Among the polyols (B), those having carbonized side chains are preferred because they can break down crystallinity. It is preferable that the diol (B-2) contains a hydrogen group. Examples of the diol (B-2) having a cyclic group include dipropylene glycol, 2,4- Dimethyl-2-ethylhexane-1,3-diol, 2-methyl-1,3-propanediol 2,2-Dimethyl-1,3-propanediol (Neopentyl glycol), 2- Methyl-2-ethyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol 2-Ethyl-2-isobutyl-1,3-propanediol, 1,3-butyl Tandiol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1, Examples of the diol include aliphatic diols having a branched structure such as 6-hexanediol and dimer diol. can be.

[0030] The content of the diol (B-2) having a hydrocarbon group in the side chain is the total content of the polyol (B). It is preferably 5 to 100 mol %, particularly preferably 20 to 90 mol %, and further preferably 4 If the content is too low, the resin crystallizes and becomes filled. If the content is too high, it tends to be difficult to obtain sufficient adhesive properties. In the production of the copolymer-based resin [I], the reaction time tends to be long.

[0031] Among the polyols (B), those capable of destroying crystallinity and increasing the elastic modulus are From this viewpoint, it is preferable that the composition contains a diol (B-3) having an alicyclic structure. As the diol (B-3) having an alicyclic structure, for example, 1,2-cyclohexanedimethano 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, Pyroglycol, Tricyclodecane Dimethanol, Adamantanediol, 2,2,4, Examples of the diol include alicyclic diols such as 4-tetramethyl-1,3-cyclobutanediol. Among these, 1,4-cyclohexanedimethanol is preferred from the viewpoint of reactivity.

[0032] The content of the diol (B-3) having an alicyclic structure in the entire polyol (B) is The content is preferably 20 to 100 mol %, particularly preferably 40 to 98 mol %, and more preferably 60 to 9 If the content is too low, the resin crystallizes and does not have sufficient viscosity. The adhesiveness tends to be poor and the elastic modulus tends to decrease, resulting in a decrease in impact resistance. If the amount is too large, the reaction time in the production of the polyester resin [I] tends to be long.

[0033] In the present invention, further, the polyester resin [I] is reacted with a crosslinking agent [IV] described later. In order to form a stress point and increase the cohesive strength, a polyol having three or more hydric groups ( B-4) is preferably used, and among them, trimethylolpropane, trimethylol Ethane, glycerin, pentaerythritol, 1,2,4-butanetriol, 1,2, It is preferable to use 5-pentanetriol and 1,2,6-hexanetriol. Among these, trimethylolpropane is particularly preferred because it is less likely to produce gel. Preferred.

[0034] The content of the trihydric or higher polyol (B-4) relative to the total polyol (B) is The content is preferably 20 mol % or less, and more preferably 0.1 to 10 mol %. The content of the trihydric or higher polyol is preferably 0.5 to 5 mol %. If the amount is too large, production of the polyester resin [I] tends to become difficult.

[0035] The polyester resin [I] used in the present invention is a mixture of the above polyvalent carboxylic acid (A) and a poly and (B) are appropriately selected, and these are subjected to a polycondensation reaction in the presence of a catalyst by a known method. It is manufactured by:

[0036] The blending ratio of the polyvalent carboxylic acid (A) and the polyol (B) is as follows: It is preferable that the polyol (B) is used in an amount of 1 to 2 equivalents per equivalent of the polyol (A), and particularly preferable. If the blending ratio of the polyol (B) is too low, the acid value becomes high. If the polymerization temperature is too high, the yield will tend to decrease.

[0037] In the polycondensation reaction, an esterification reaction is carried out first, and then the polycondensation reaction is carried out.

[0038] In such an esterification reaction, a catalyst is usually used. Specifically, for example, tetrahydrofuran Titanium catalysts such as isopropyl titanate and tetrabutyl titanate, antimony trioxide antimony catalysts such as ruthenium dioxide, germanium catalysts such as germanium dioxide, and zinc acetate catalysts. Examples of catalysts include lead, manganese acetate, and dibutyltin oxide. Among these, the most popular one is fluorine-based, which has a good balance between high catalytic activity and color. , antimony trioxide, tetrabutyl titanate, germanium dioxide, and zinc acetate are preferred. Of these, germanium dioxide is particularly preferred.

[0039] The amount of the catalyst to be blended is 1 to 10,000 ppm by weight based on the total copolymerization components. It is preferable that the concentration is 10 to 5000 ppm, particularly preferably 20 to 3000 ppm. If the blending amount is too small, the polymerization reaction tends not to proceed sufficiently. If the amount is too large, there is no advantage such as shortening the reaction time, and side reactions tend to occur.

[0040] The reaction temperature during the esterification reaction is preferably 200 to 300° C., and particularly preferably The reaction temperature is preferably 210 to 280° C., and more preferably 220 to 260° C. If the temperature is too high, the reaction will not proceed sufficiently, and if the temperature is too high, side reactions such as decomposition will occur. In addition, the reaction is usually carried out under normal pressure.

[0041] After the esterification reaction, a polycondensation reaction is carried out. The reaction conditions for the polycondensation reaction are as follows: The reaction temperature is preferably 220 to 280°C, particularly preferably 23 The reaction temperature should be kept between 0 and 270℃, and the reaction system should be gradually depressurized to a final pressure of 5hPa or less. If the reaction temperature is too low, the reaction tends not to proceed sufficiently, whereas if the reaction temperature is too high, If the temperature is too high, side reactions such as decomposition tend to occur.

[0042] Thus, the polyester resin [I] used in the present invention is obtained.

[0043] The polyester resin [I] generally contains a structural unit derived from a polyvalent carboxylic acid (A), and polyol (B), but the aromatic polyvalent carboxylic acids, particularly non- The structural unit derived from the symmetric aromatic dicarboxylic acid (A-1) is derived from the polyvalent carboxylic acid (A). When the structural unit is included in the structure, the structure derived from the asymmetric aromatic dicarboxylic acid (A-1) The units are preferably 1 to 90 mol % of the structural units derived from the polyvalent carboxylic acids (A). , particularly preferably 5 to 80 mol %, more preferably 10 to 70 mol %, and further preferably The content is preferably 15 to 60 mol %, more preferably 20 to 50 mol %. If this occurs, the adhesive strength at high temperatures may decrease or the resin may crystallize, resulting in insufficient adhesive performance. If the content is too high, the initial adhesive strength (tack) tends to decrease. There is.

[0044] The structural unit derived from the aliphatic dicarboxylic acid (A-2) having 4 or more carbon atoms is a polyvalent carbo When it is included as a structural unit derived from the carboxylic acids (A), it is an aliphatic dicarboxylic acid having 4 or more carbon atoms. The structural unit derived from the polycarboxylic acid (A) is 5 to 100 times the structural unit derived from the polycarboxylic acid (A). % by mole, more preferably 20 to 95 mol %, and even more preferably 30 %. The content of the aryl group is preferably from 40 to 90 mol %, more preferably from 40 to 85 mol %, and particularly preferably from 50 to 80 mol %. If the content is too low, the glass transition temperature of the polyester resin [I] becomes high. If the content is too high, sufficient adhesive strength cannot be obtained. At high temperatures, the adhesive strength tends to decrease or the resin tends to crystallize, resulting in insufficient adhesive performance. There is.

[0045] The structural unit derived from the trivalent or higher polyvalent carboxylic acid (A-3) is ), when it is included as a structural unit derived from trivalent or higher polyvalent carboxylic acids (A-3), The structural units are preferably 10 mol % or less of the structural units derived from the polyvalent carboxylic acids (A). The content is preferably 0.1 to 5 mol %. If the content is too high, the polyester The polyester resin [I] tends to gel during production.

[0046] The structural unit derived from the linear aliphatic diol (B-1) is When it is included as a structural unit derived from a linear aliphatic polyol (B-1), The structural units are preferably 1 to 100 mol % of the structural units derived from the polyol (B), More preferably, it is from 2 to 80 mol %, further preferably from 3 to 70 mol %, and particularly preferably from 4 to The content is preferably 6 to 60 mol %, and more preferably 5 to 50 mol %. The reactivity of the polyester resin [I] during production tends to decrease. If the amount is too large, the polyester resin [I] will crystallize, and the initial adhesive strength of the adhesive will tend to decrease. There is a direction.

[0047] On the other hand, the structural unit derived from the diol (B-2) having a hydrocarbon group in the side chain is a polyol. When it is included as a structural unit derived from diol (B), it is a diol (B The structural units derived from -2) account for 5 to 100 mol % of the structural units derived from polyol (B). It is particularly preferable that the content is 20 to 90 mol %, and further preferably 40 to 80 mol %. If the content is too low, the polyester resin [I] will crystallize and the initial phase of the adhesive will be If the content is too high, the polyester resin [I ] tends to decrease in reactivity during production.

[0048] Furthermore, the structural unit derived from the diol (B-3) having an alicyclic structure is When it is included as a structural unit derived from a diol (B-3) having an alicyclic structure, The structural units are preferably 20 to 100 mol % of the structural units derived from the polyol (B). In particular, the content is preferably 40 to 98 mol %, and more preferably 60 to 95 mol %. If the proportion is too low, the resin will crystallize, making it difficult to obtain sufficient adhesive performance, and the elastic modulus will be low. If the content is too high, the polyester tends to have a low impact resistance. In the production of the copolymer-based resin [I], the reaction time tends to be long.

[0049] The structural unit derived from the trihydric or higher polyol (B-4) is When the structural unit is included as a structural unit of the trihydric or higher polyol (B-4), the structural unit derived from the trihydric or higher polyol (B-4) is The structural unit derived from the polyol (B) is preferably 10 mol % or less, and more preferably If the content is too high, the polyester resin may be easily dissolved during production. [I] tends to gel, making production difficult.

[0050] Here, the ratio of structural units (composition ratio) derived from each component of the polyester resin [I] is as follows: For example, it can be determined by NMR.

[0051] The glass transition temperature (Tg) of the polyester resin [I] is -70 The temperature is preferably from -60 to 10°C, more preferably from -50 to 0°C, and particularly preferably from -20 to 20°C. The glass transition temperature is preferably from -40 to -5°C, and particularly preferably from -30 to -10°C. If the Tg is too high, the flexibility is lost, the initial adhesive strength decreases, and the adhesive strength decreases with finger pressure. If the temperature is too low, the cohesive strength will decrease and the adhesive sheet will not adhere well. This tends to cause the parts to become easily deformed, marring the appearance.

[0052] The glass transition temperature (Tg) of the polyester resin [I] is measured by TA Instruments. The values ​​are measured using a differential scanning calorimeter DSC Q20 manufactured by Menthon. The measurement temperature range is −90 to 100° C., and the temperature rise rate is 10° C. / min.

[0053] The weight average molecular weight of the polyester resin [I] is 5 or less from the viewpoint of the cohesive strength of the adhesive. 000 to 300000. Preferably, it is 8000 to 200000, and more preferably is preferably 10,000 to 150,000, and more preferably 20,000 to 100,000. If the weight average molecular weight is too small, the adhesive will not have sufficient cohesive strength, and it will have poor heat resistance and mechanical properties. In addition, if the weight average molecular weight is too large, the strength of the polyester resin tends to decrease. During the production of the oil [I], it becomes easy for it to gel, making it difficult to obtain a resin, and furthermore, the adhesion to the substrate becomes poor. There is a tendency for it to decrease.

[0054] In the present invention, the weight average molecular weight is the weight average molecular weight converted into the standard polystyrene molecular weight. The molecular weight was measured by high performance liquid chromatography (Waters, "ACQUITY APC The system was equipped with one ACQUITY APC XT 450 column and one ACQUITY One Y APC XT 200 and two ACQUITY APC XT 45, for a total of four It is measured by using two books in series.

[0055] The acid value of the polyester resin [I] is preferably 10 mgKOH / g or less. In particular, it is preferably 3 mgKOH / g or less, and more preferably 1 mgKOH / g or less. If the acid value is too high, hydrolysis may easily proceed, or metal or other substances may be present on one side of the adhesive layer. For example, when a metal oxide thin film layer is laminated, it tends to corrode. When such a structure is used, corrosion tends to occur, decreasing the electrical conductivity of the metal oxide thin film.

[0056] Here, the acid value of the polyester resin [I] is the neutralization value based on JIS K 0070. It is determined by titration.

[0057] <Ultraviolet absorber [II]> The pressure-sensitive adhesive composition of the present invention comprises the above-mentioned polyester resin [I] and a specific ultraviolet absorber [II]. The polyester resin [I] and a specific ultraviolet absorber [II] are included. By virtue of this, the pressure-sensitive adhesive composition of the present invention has excellent adhesive strength and adhesion to substrates while exhibiting little yellowing. It has the effect of being excellent in ultraviolet absorbing ability. In the case of acrylic resins that are generally used as pressure-sensitive adhesive compositions, Even if the above-mentioned specific ultraviolet absorber [II] is contained in the adhesive composition, the above-mentioned effect is not obtained. The present invention relates to a polyester resin and the specific ultraviolet absorber. When selectively combined with the above effects, particularly yellowing resistance and ultraviolet absorbing ability, It has been found that excellent effects can be obtained.

[0058] The ultraviolet absorber [II] used in the present invention has a hydroxyl value of 900 mgKOH / g or less. It is important that the pH is 800 mgKOH / g or less, and more preferably 600 mgKOH / g or less. gKOH / g or less, more preferably 400 mgKOH / g or less, and even more preferably The preferred pH is 300 mg KOH / g, and more preferably 200 mg KOH / g or less. If the hydroxyl value of the radiation absorber [II] is too large, the resistance to yellowing decreases. The hydroxyl value can be calculated, for example, from the following formula. Hydroxyl value = 56.1 x 1000 x number of hydroxyl groups per molecule / number average molecular weight

[0059] In addition, the ultraviolet absorber [II] used in the present invention preferably has a hydroxyl group equivalent of 65 or more. It is preferably 100 to 1000, particularly preferably 200 to 800, and further preferably The preferable range is 300 to 700. If the hydroxyl equivalent of the ultraviolet absorber [II] is too small, the yellowing resistance is poor. There is a tendency for degeneration to decrease.

[0060] The above-mentioned hydroxyl group equivalent means the molecular weight per hydroxyl group, and is calculated, for example, by the following formula: It is possible. Hydroxyl equivalent = number average molecular weight / number of hydroxyl groups in one molecule

[0061] The number average molecular weight of the ultraviolet absorber [II] is preferably 180 to 1,500. It is preferable that the molecular weight is 250 to 1000, and it is particularly preferable that the molecular weight is 300 to 800. If the number average molecular weight of the ultraviolet absorber [II] is too small, the yellowing resistance tends to decrease. If the number average molecular weight is too large, the adhesive strength tends to decrease.

[0062] The ultraviolet absorber [II] preferably has a maximum absorption wavelength of 300 to 395 nm. It is preferable that the wavelength is in the range of 320 to 390 nm, and more preferable that the wavelength is in the range of 330 to 380 nm. is particularly preferred, and it is particularly preferred that the ultraviolet absorbing agent has a wavelength of 340 to 370 nm. If the maximum absorption wavelength of is too short, the ultraviolet absorbing performance in the long wavelength region tends to decrease. If the absorption wavelength is too long, the resistance to yellowing tends to decrease.

[0063] The ultraviolet absorber [II] is a triazine compound, a triazole compound, a cyanoacrylate compound, At least one compound selected from the group consisting of acrylate compounds and benzophenone compounds. Among them, triazine-based compounds, triazole-based compounds, and benzene-based compounds are more preferable. The preferred compounds are benzophenone compounds, and particularly preferred are triazine compounds and triazole compounds. It is an object.

[0064] Examples of the triazine compounds include 2-(2-hydroxy-4-methoxyphenyl)-2-phenylpropanediol. 2-(2-hydroxy-4-enyl)-4,6-diphenyl-1,3,5-triazine (2-hydroxyphenyl)-4,6-diphenyl-1,3,5-triazine 2-(4-propoxyphenyl)-4,6-diphenyl-1,3,5-triazine 2-Hydroxy-4-butoxyphenyl)-4,6-diphenyl-1,3,5-triazine 2-(2-hydroxy-4-hexyloxyphenyl)-4,6-diphenyl-1, 3,5-Triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6- Diphenyl-1,3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl) 2-(2-hydroxy-4-phenyl)-4,6-diphenyl-1,3,5-triazine 2,4-bis(phenyloxyphenyl)-4,6-diphenyl-1,3,5-triazine (2-hydroxy-4-butoxyphenyl)-6-(2,4-dibutoxyphenyl)-1 ,3-5-triazine, 2,4,6-tris(2-hydroxy-4-hexyloxy-3 -methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-[1-octyl 4,6-bis(4-phenylphenyl)- 1,3,5-Triazine, 2-[4-[(2-hydroxy-3-dodecyloxypropyl )oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)- 1,3,5-Triazine, 2-[4-[(2-hydroxy-3-tridecyloxypropyl 4,6-bis(2,4-dimethylphenyl)-2-hydroxyphenyl -1,3,5-triazine, 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyl 4,6-bis(2,4-dimethylphenyl)-2-hydroxyphenyl )-1,3,5-triazine, 2,4-bis(2,4-dimethylphenyl)-6-[2- Hydroxy-4-(3-octyloxy-2-hydroxypropyloxy)-5-α-chloride 2,4-bis(2,4-dimethylphenyl)-6-[ 2-Hydroxy-4-(3-nonyloxy-2-hydroxypropyloxy)-5-α- cumylphenyl]-s-triazine, 2,4-bis(2,4-dimethylphenyl)-6- [2-hydroxy-4-(3-decyloxy-2-hydroxypropyloxy)-5-α -cumylphenyl]-s-triazine, 2-(2-hydroxy-4-acryloyloxy Ethoxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triphenyl These may be used alone or in combination of two or more. The above may be used in combination. Among them, 2,4-bis(2-hydroxy-4-butoxyphenyl) Preferred is 2,4-dibutoxyphenyl)-6-(2,4-dibutoxyphenyl)-1,3-5-triazine.

[0065] Commercially available triazine compounds include, for example, "Tinuvin" manufactured by BASF. 400", "Tinuvin405", "Tinuvin460", "Tinuvin4 77" and "Tinuvin479".

[0066] The triazole-based compound is, for example, C7-C9-alkyl-3-[3-(2 H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy Diphenyl]propion ether, 2-(2-hydroxy-5-methylphenyl)benzo Triazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole 2-(2-hydroxy-3,5-dicumylphenyl)phenylbenzotriazol 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chloro Benzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutane 2-(2-Hydroxyethyl)-6-(2H-benzotriazol-2-yl)phenol], 2-(2-Hydroxy-3,5-di-tert-butylphenyl)benzotriazole (3,5-di-tert-butylphenyl)-5-chlorobenzotriazole, 2- (2-hydroxy-3,5-di-tert-amylphenyl)benzotriazole, 2- (2-Hydroxy-5-tert-octylphenyl)benzotriazole, 2-(2- Hydroxy-5-tert-butylphenyl)benzotriazole, 2-(2-hydroxy 2,2'-methylenebis(4-octoxyphenyl)benzotriazole 2,2'-p-phenylenebis(1,3-benzotriazolephenyl) 2-[2-hydroxy-3-(3,4,5,6-tetrahydro- Benzotriazolides such as (5-methylphenyl)-4-(1,2-difluorophthalimidomethyl)-benzotriazole These may be used alone or in combination of two or more. C7-C9-Alkyl-3-[3-(2H-benzotriazol-2-yl)-5-(1 , 1-dimethylethyl)-4-hydroxyphenyl]propion ether is preferred.

[0067] Commercially available triazole compounds include, for example, "Tinuvi" manufactured by BASF. nPS”, “Tinuvin99-2”, “Tinuvin326”, “Tinuvin 384-2”, “Tinuvin900”, “Tinuvin928”, “Tinuvi n970" and "Tinuvin1130".

[0068] The cyanoacrylate compound is, for example, 2-ethylhexyl-2-cyano -3,3-Diphenylacrylate, Ethyl-2-cyano-3,3-diphenylacrylate acrylate, octyl-2-cyano-3,3-diphenyl acrylate, etc. may be used alone or in combination of two or more.

[0069] Commercially available cyanoacrylate compounds include, for example, "Uvi" manufactured by BASF. Examples include "nul3035", "Uvinul3039", and "Uvinul3030". do. The benzophenone compounds include, for example, 2,2-dihydroxy-4,4-dimethyl 2-Hydroxy-4-octyloxybenzophenone, etc. can be. Commercially available benzophenone compounds include, for example, "Uvinu" manufactured by BASF. l3049" and "Chimassorb81" are examples.

[0070] Among the above ultraviolet absorbents [II], this has better adhesion, less yellowing, and is resistant to ultraviolet rays. At least one selected from triazine compounds and triazole compounds due to their excellent absorption ability is used. It is preferable that both are one type.

[0071] The content of the ultraviolet absorber [II] is based on 100 parts by weight of the polyester resin (I). The amount is preferably 0.01 to 20 parts by weight, particularly preferably 0.1 to 10 parts by weight, and more preferably 0.01 to 20 parts by weight. The content of the ultraviolet absorber [II] is more preferably 0.2 to 5 parts by weight. If the amount is too small, the adhesion tends to decrease, and if the amount is too small, the ultraviolet absorbing performance tends to decrease.

[0072] <Hydrolysis inhibitor [III]> The pressure-sensitive adhesive composition of the present invention preferably further contains a hydrolysis inhibitor [III]. The hydrolysis inhibitor [III] is contained in order to ensure long-term durability.

[0073] As the hydrolysis inhibitor [III], a conventionally known one can be used, for example. and compounds which react with and bond to the carboxylic acid end groups of the polyester resin [I]. Specifically, functional groups such as a carbodiimide group, an epoxy group, and an oxazoline group are The hydrolysis inhibitor [III] may be used alone or in combination. The above can be used in combination. Among them, the carbodiimide group-containing compound is preferably a carboxylic acid terminal compound. This is preferred because it is highly effective in eliminating the catalytic activity of the protons derived from the terminal groups.

[0074] The carbodiimide group-containing compound is usually a carbodiimide group (-N=C=N- A known carbodiimide compound having one or more groups in the molecule may be used. Compounds containing two or more carbodiimide groups in the molecule to improve durability under high humidity conditions. That is, polyvalent carbodiimide compounds are preferred, and in particular, compounds having a carbodiimide group are preferred. It is preferable that the compound contains 3 or more, more preferably 5 or more, and especially 7 or more in the molecule. In addition, the number of carbodiimide groups contained in the polyvalent carbodiimide compound in the molecule is The number of carbodiimide groups is usually 50 or less. If there are too many carbodiimide groups, the molecular structure becomes too large. This tends to be undesirable.

[0075] The carbodiimide group-containing compound is a compound which is produced by reacting a diisocyanate in the presence of a carbodiimide catalyst. A high molecular weight polycarbodiimide produced by the decarboxylation condensation reaction of an anate is used. It is also preferable to have

[0076] Such high molecular weight polycarbodiimides may be synthesized or commercially available products may be used. To synthesize a high molecular weight polycarbodiimide, for example, Examples include those obtained by carbonic acid condensation reaction.

[0077] Such diisocyanates include, for example, 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 Diphenyl-2,4-diisocyanate, isophorone diisocyanate, 4,4'-diisocyanate Examples include cyclohexylmethane diisocyanate and tetramethylxylylene diisocyanate. These can be used alone or in combination of two or more kinds.

[0078] Furthermore, the terminal isocyanate groups of the high molecular weight polycarbodiimide are sealed with a sealing agent. In terms of storage stability, it is preferable to use a sealing agent having an isocyanate group and Compounds with reactive active hydrogen or compounds with isocyanate groups are examples. For example, one substituent selected from a carboxy group, an amino group, and an isocyanate group may be added. Monoalcohols, monocarboxylic acids, monoamines, and monoisocyanates having Examples include:

[0079] Commercially available carbodiimide group-containing compounds include, for example, Carbodiimide (manufactured by Nisshinbo Chemical Co., Ltd.) Among them, Carbodilite (registered trademark) standard) "V-01", "V-02B", "V-03", "V-04K", "V-04PF" "V-05", "V-07", "V-09", and "V-09GB" are compatible with organic solvents. This is preferable in that it is excellent in terms of

[0080] The carbodiimide equivalent of the carbodiimide group-containing compound is preferably 50 to 100 00, particularly 100 to 1000, and further preferably 150 to 500. The carbodiimide equivalent indicates the chemical formula weight per one carbodiimide group.

[0081] The epoxy group-containing compound used as the hydrolysis inhibitor [III] is Examples of the glycidyl ester compounds include glycidyl ether compounds. These can be used alone or in combination of two or more.

[0082] Specific examples of the glycidyl ester compound include benzoic acid glycidyl ester, t-Bu-benzoic acid glycidyl ester, p-toluic acid glycidyl ester, cyclohexyl Xanthate glycidyl ester, pelargonic acid glycidyl ester, stearic acid Glycidyl esters, lauric acid glycidyl esters, palmitic acid glycidyl esters , behenic acid glycidyl ester, versatic acid glycidyl ester, oleic acid glycidyl ester Glycidyl ester of linoleic acid, glycidyl ester of linoleic acid, glycidyl ester of linoleic acid, Glycidyl ester of phenylalanine, glycidyl ester of stearolic acid, diglyceryl terephthalate Glycidyl ester, isophthalic acid diglycidyl ester, phthalic acid diglycidyl ester , Naphthalenedicarboxylic acid diglycidyl ester, Methyl terephthalic acid diglycidyl ester ter, diglycidyl hexahydrophthalate, diglycidyl tetrahydrophthalate Esters, Diglycidyl ester of cyclohexanedicarboxylic acid, Diglycidyl adipate Esters, diglycidyl succinate, diglycidyl sebacate, dodecane Diglycidyl ester of dicarboxylic acid, diglycidyl ester of octadecanedicarboxylic acid, triglyceride Examples include mellitic acid triglycidyl ester and pyromellitic acid tetraglycidyl ester. These can be used alone or in combination of two or more kinds.

[0083] Specific examples of the glycidyl ether compound include phenyl glycidyl ether, o-Phenyl glycidyl ether, 1,4-bis(β,γ-epoxypropoxy)butane , 1,6-bis(β,γ-epoxypropoxy)hexane, 1,4-bis(β,γ-epoxy 1-(β,γ-epoxypropoxy)benzene, 1-(β,γ-epoxypropoxy)-2-ethoxyethane, 1-(β,γ-epoxypropoxy)-2-benzyloxyethane, 2,2-bis-[р -(β,γ-epoxypropoxy)phenyl]propane, and 2,2-bis-(4-phenyl Bis(hydroxyphenyl)propane and 2,2-bis(4-hydroxyphenyl)methane Examples include bisglycidyl polyethers obtained by the reaction of sphenol with epichlorohydrin. These can be used alone or in combination of two or more kinds.

[0084] The oxazoline group-containing compound is preferably a bisoxazoline compound. Specifically, for example, 2,2'-bis(2-oxazoline), 2,2'-bis(4-methyl-2 -oxazoline), 2,2'-bis(4,4-dimethyl-2-oxazoline), 2,2'- Bis(4-ethyl-2-oxazoline), 2,2'-bis(4,4'-diethyl-2-oxazoline) 2,2'-bis(4-propyl-2-oxazoline), 2,2'-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-oxazoline) 2,2'-o-phenylenebis(2-oxazoline), 2,2'-p-phenylene 2,2'-p-phenylenebis(4,4-diphenyl 2,2'-m-phenylenebis(4-methyl-2-oxazoline) 2,2'-m-phenylenebis(4,4-dimethyl-2-oxazoline), 2 ,2'-Ethylenebis(2-oxazoline), 2,2'-Tetramethylenebis(2-oxa 2,2'-Hexamethylenebis(2-oxazoline), 2,2'-Octamethylene 2,2'-decamethylenebis(2-oxazoline), 2, 2'-Ethylenebis(4-methyl-2-oxazoline), 2,2'-tetramethylenebis( 4,4-Dimethyl-2-oxazoline), 2,2'-9,9'-diphenoxyethane bis( 2-oxazoline), 2,2'-cyclohexylenebis(2-oxazoline), 2,2'- Examples of the aryl groups include diphenylene bis(2-oxazoline), and among these, 2 ,2'-bis(2-oxazoline) from the viewpoint of reactivity with polyester resin (A) These may be used alone or in combination of two or more.

[0085] It is preferable that the hydrolysis inhibitor [III] has low volatility. It is preferable to use a copolymer having a high average molecular weight, usually 300 to 10,000, preferably 1 Use one with a value between 000 and 5000. As the hydrolysis inhibitor [III], a compound having a high weight average molecular weight is preferred from the viewpoint of hydrolysis resistance. It is preferable to use a hydrolysis inhibitor [III] having a weight average molecular weight of 500 or more. It is preferable that the number of ions is 2000 or more, more preferable that the number of ions is 3000 or more. The upper limit of the weight average molecular weight is usually 50,000. If the molecular weight of the hydrolysis inhibitor [III] is too small, the hydrolysis resistance tends to decrease. However, if the molecular weight is too large, the compatibility with the polyester resin [I] tends to decrease. be.

[0086] The content of the hydrolysis inhibitor [III] is 100 parts by weight of the polyester resin [I]. The amount is preferably 0.01 to 10 parts by weight, and particularly preferably 0.1 to 5 parts by weight. parts by weight, more preferably 0.3 to 3 parts by weight, and particularly preferably 0.5 to 2 parts by weight. If the content is too high, the compatibility with the polyester resin [I] is poor and turbidity occurs. If the amount is too small, it tends to be difficult to obtain sufficient durability.

[0087] The content of the hydrolysis inhibitor [III] is determined by the acid value of the polyester resin [I]. It is preferable to optimize the content depending on the type of polyester. The total mole number (a) of the acidic functional groups in the ester resin of the polyester-based pressure-sensitive adhesive composition The molar ratio [(b) / (a)] of the total number of moles (b) of functional groups of the hydrolysis inhibitor [III] in , 0.5≦(b) / (a) is preferable, and 1≦(b) / (a)≦ is particularly preferable. 1000, and more preferably 1.5≦(b) / (a)≦100. If the molar ratio of (b) to (a) is too low, the moisture and heat resistance tends to decrease. If the molar ratio of (b) to (a) is too high, the compatibility with the polyester resin [I] will be poor. The adhesive strength, cohesive strength and durability tend to decrease.

[0088] <Crosslinking agent [IV]> Examples of the crosslinking agent [IV] include polyisocyanate compounds, polyepoxy compounds, and the like. At least one of the hydroxyl group and the carboxyl group contained in the polyester resin [I] is Among these, compounds with functional groups that react with the other are those that have the highest initial adhesion and mechanical strength. Polyisocyanate compounds are particularly used because they provide a good balance between mechanical strength and heat resistance. It is preferable that

[0089] Examples of such polyisocyanate compounds include tetramethylene diisocyanate. Hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate Anate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate xylylene diisocyanate, hydrogenated xylylene diisocyanate, tetramethyl xylylene diisocyanate Silylene diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane and polyisocyanates such as triisocyanate. and polyol compounds such as trimethylolpropane. Examples of the biuret and isocyanurate derivatives of an anate compound include the above-mentioned poly In isocyanate compounds, the isocyanate portion is blocked with phenol, lactam, etc. These crosslinking agents [IV] can be used alone or in combination. Alternatively, two or more types may be used in combination.

[0090] The content of the crosslinking agent [IV] depends on the molecular weight of the polyester resin [I] and the intended use. Although it can be appropriately selected, it is usually the hydroxyl group and the carbo group contained in the polyester resin [I] that are the most suitable. The reactive group contained in the crosslinking agent [IV] is 0.2 times the equivalent of at least one of the alkoxy groups. The crosslinking agent [IV] is preferably contained in an amount of 0.5 to 10 equivalents, and particularly preferably 0.5 to 10 equivalents. The amount is preferably from 0.5 to 5 equivalents, and more preferably from 0.5 to 3 equivalents. If the equivalent number of the reactive group contained in the crosslinking agent [IV] is too small, the cohesive strength tends to decrease. If it is too large, the flexibility tends to decrease.

[0091] In addition, in the reaction between the polyester resin [I] and the crosslinking agent [IV], and [IV] an organic solvent having no functional group that reacts with the component, such as ethyl acetate, butyl acetate, etc. esters such as ethyl ketone and methyl isobutyl ketone; ketones such as toluene; Organic solvents such as aromatics such as benzene and xylene can be used alone or in combination. Two or more types can be used in combination.

[0092] <Urethane catalyst [V]> The pressure-sensitive adhesive composition of the present invention preferably further contains a urethanization catalyst [V]. Examples of the urethane catalyst [V] include organometallic compounds, tertiary amine compounds, etc. These can be used alone or in combination of two or more.

[0093] Examples of the organometallic compounds include zirconium compounds, iron compounds, tin compounds, and the like. Examples of compounds include titanium compounds, lead compounds, cobalt compounds, and zinc compounds. can. Examples of zirconium compounds include zirconium naphthenate and zirconium acetate. Examples thereof include ethyl acetonate. Examples of iron-based compounds include iron acetylacetonate and iron 2-ethylhexanoate. Some examples include: Examples of tin compounds include dibutyltin dichloride, dibutyltin oxide, and dibutyltin. tin dilaurate and the like. Examples of titanium compounds include dibutyltitanium dichloride and tetrabutyltitanium. butoxytitanium trichloride, and the like. Examples of lead-based compounds include lead oleate, lead 2-ethylhexanoate, lead benzoate, Examples include lead naphthenate. Examples of cobalt compounds include cobalt 2-ethylhexanoate and cobalt benzoate. Examples include Examples of zinc compounds include zinc naphthenate and zinc 2-ethylhexanoate. can be done.

[0094] Examples of the tertiary amine compound include triethylamine and triethylenediamine. amine, 1,8-diazabicyclo-(5,4,0)-undecene-7, and the like.

[0095] Among these urethane catalysts [V], the following are the most effective in terms of reaction speed and pot life of the adhesive layer: Organometallic compounds are preferred, zirconium compounds are particularly preferred, and zirconium compounds are particularly preferred. Most commonly, zirconium acetylacetonate.

[0096] [Catalyst inhibitors] The pressure-sensitive adhesive composition of the present invention has the following advantages: it extends the pot life and improves the coatability. It is preferable that the urethanization catalyst [V] contains a catalytic inhibitor. Examples of catalytic inhibitors include methyl acetoacetate, ethyl acetoacetate, and acetoacetic acid. β-ketoacetate such as octyl, oleyl acetoacetate, lauryl acetoacetate, and stearyl acetoacetate β-Acetate, acetylacetone, 2,4-hexanedione, benzoylacetone, etc. These are keto-enol tautomeric compounds, and By protecting the urethanization catalyst [V], the catalytic activity of the urethanization catalyst [V] in solution is improved. The adhesive composition after blending is prevented from excessively increasing in viscosity and from gelling, and the adhesive composition The pot life of the composition can be extended. Among these, from the viewpoint of the balance between pot life and curing speed, It is preferable to use acetylacetone as the catalyst inhibitor. can be used in combination of two or more.

[0097] The mixing ratio (weight ratio) of the catalyst inhibitor and the urethane catalyst [V] is: catalyst inhibitor: urethane The rethanation catalyst [V] is preferably in the range of 0.001:1 to 15:1, and more preferably The ratio is preferably 0.005:1 to 13:1, and particularly preferably 0.01:1 to 10:1. If the amount of catalyst inhibitor is too small compared to the amount of urethane catalyst [V], If the amount is too large, the curing speed tends to decrease. do.

[0098] <Silane coupling agents [VI]> The pressure-sensitive adhesive composition of the present invention preferably further contains a silane coupling agent [VI]. It is nice. The silane coupling agent [VI] is, for example, an amino group-containing silane coupling agent. agents, epoxy group-containing silane coupling agents, vinyl group-containing silane coupling agents, (meth ) acryloyl group-containing silane coupling agents, mercapto group-containing silane coupling agents, Examples of the silane coupling agent include isocyanate group-containing silane coupling agents. These may be used alone or in combination. More than one species may be used in combination.

[0099] Examples of the amino group-containing silane coupling agent include 3-aminopropyltrimethylsilane. Triethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)amino Examples include 3-phenylaminopropyltrimethoxysilane and 3-phenylaminopropyltrimethoxysilane. Can be obtained.

[0100] The epoxy group-containing silane coupling agent is, for example, 3-glycidoxypropyl 3-Glycidoxypropylmethyldimethoxysilane, 3-Glycidoxypropylmethyldimethoxysilane Doxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane , 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and the like.

[0101] Examples of the vinyl group-containing silane coupling agent include vinyltriacetoxysilane. Examples of the silane include vinyltrimethoxysilane, vinyltriethoxysilane, and the like.

[0102] Examples of the (meth)acryloyl group-containing silane coupling agent include 3-(meth)acryloyl group-containing silane coupling agents. ) Acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyl Dimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 3-( meth)acryloxypropyltriethoxysilane and the like.

[0103] Examples of the mercapto group-containing silane coupling agent include 3-mercaptopropionate. 3-Mercaptotrimethoxysilane, 3-Mercaptomethyldimethoxysilane, 3-Mercaptotriethylene Toxicsilane and the like.

[0104] The isocyanate group-containing silane coupling agent is, for example, tris-(trimethylsilyl) Silane coupling agents containing isocyanurate groups such as (methoxysilylpropyl) isocyanurate Examples of suitable anti-bacterial agents include 3-isocyanatepropyltriethoxysilane.

[0105] Among these silane coupling agents, epoxy group-containing silane coupling agents are preferred. Of these, 3-glycidoxypropyltrimethoxysilane is particularly preferred.

[0106] The content of the silane coupling agent [VI] is based on 100 parts by weight of the polyester resin [I]. The amount is usually 0.01 to 10 parts by weight, and preferably 0.02 to 5 parts by weight. Particularly preferably, it is from 0.03 to 3 parts by weight, and further preferably, it is from 0.1 to 1 part by weight. If the content of the silane coupling agent [VI] is too high, the adhesive strength tends to decrease. If the thickness is too small, the adhesion to the substrate etc. tends to decrease.

[0107] In the pressure-sensitive adhesive composition of the present invention, the polyester resin [I], the ultraviolet absorber In addition to the above-mentioned components [II], the hydrolysis inhibitor [III], and the crosslinking agent [IV], any other components that do not impair the effects of the present invention may be used. Within the range, antioxidants such as hindered phenols, softeners, and ultraviolet absorbing agents other than those mentioned above Additives such as binders, stabilizers, antistatic agents, tackifiers, etc., and other inorganic or organic fillers, Additives such as powders and particulates, such as metal powders and pigments, can be blended. Two or more of them can be used in combination.

[0108] In addition to the above additives, the adhesive composition of the present invention also includes the following components: It may contain a small amount of impurities contained in the raw materials.

[0109] Such a pressure-sensitive adhesive composition may be, for example, a mixture of the above-mentioned polyester resin [I] and an ultraviolet absorber [ II] and optional ingredients, etc., are prepared and mixed during the manufacture of polyester resin [I]. Polyester resin [I] solution obtained by dissolving in an organic solvent or by dispersing in an aqueous solution of polyester resin [I] and dispersing the mixture using a mixing roller.

[0110] The pressure-sensitive adhesive of the present invention is made of the pressure-sensitive adhesive composition. The composition is crosslinked (cured).

[0111] The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive. The pressure-sensitive adhesive sheet is a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one or both sides of a supporting substrate. Alternatively, the double-sided PSA sheet may be of a substrateless type that does not have a substrate. The pressure-sensitive adhesive sheet of the present invention is particularly a pressure-sensitive adhesive sheet for optical members used for bonding optical members. It is suitable as a support. In the present invention, the term "sheet" includes "film" and "tape." do.

[0112] <Adhesive sheet> The pressure-sensitive adhesive sheet can be produced, for example, as follows. The method for producing such a pressure-sensitive adhesive sheet is according to a known method for producing a pressure-sensitive adhesive sheet. For example, the pressure-sensitive adhesive composition can be applied to one surface of a substrate, followed by drying, A pressure-sensitive adhesive layer is formed, and a release sheet is attached to its surface (the surface opposite to the surface that contacts the substrate). By further curing, the adhesive layer is formed on at least one side of the substrate. Thus, the pressure-sensitive adhesive sheet of the present invention having the adhesive layer provided on the surface is obtained.

[0113] Alternatively, the pressure-sensitive adhesive composition is applied onto a release sheet, followed by drying to form a pressure-sensitive adhesive layer; A substrate is attached to the surface (the side opposite to the release sheet) and cured as necessary. The pressure-sensitive adhesive sheet of the present invention can also be obtained.

[0114] Also, a pressure-sensitive adhesive layer is formed on a release sheet, and the surface (the surface opposite to the surface in contact with the release sheet) By laminating the release sheet and another release sheet to the substrate, a substrate-less substrate having no substrate is obtained. It is possible to produce a substrate-less double-sided PSA sheet of this type.

[0115] When using the obtained pressure-sensitive adhesive sheet or substrate-less double-sided pressure-sensitive adhesive sheet, the release sheet is adhered to the sheet. The adhesive layer is peeled off and the adhesive layer is attached to an adherend.

[0116] Examples of the substrate include polyethylene naphthate, polyethylene terephthalate, Polybutylene terephthalate, polyethylene terephthalate / isophthalate copolymer, etc. Polyester resins such as polyethylene, polypropylene, polymethylpentene, etc. olefin resins; polyvinyl fluoride, polyvinylidene fluoride, polyethylene fluoride, etc. Fluorinated ethylene resin; nylon 6, nylon 6,6 and other polyamides; polyvinyl chloride, Polyvinyl chloride / vinyl acetate copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl vinyl alcohol copolymers, polyvinyl alcohol, vinylon and other vinyl polymers; triacetic acid cellulosic acid Cellulosic resins such as cellulose and cellophane; polymethyl methacrylate, polymethacrylic acid acrylic resins such as polystyrene, polyethyl acrylate, polybutyl acrylate, etc. Polyimide; cycloolefin polymer; polycarbonate; polyarylate; Synthetic resin sheet; Metal foils such as aluminum, copper, and iron; Paper such as fine paper and glassine paper; Examples of the material include woven fabrics and nonwoven fabrics made of glass fibers, natural fibers, synthetic fibers, and the like. These substrates can be used as a single layer or as a multi-layer structure in which two or more types are laminated. can.

[0117] Among these, substrates made of polyethylene terephthalate and polyimide are particularly preferred. In particular, polyethylene terephthalate is preferred because of its excellent adhesiveness to pressure-sensitive adhesives. In particular, the adhesive is preferably polyethylene terephthalate having a thin metal layer. The adhesive strength is excellent, and the substrate can be stably maintained without corroding the metal thin film layer. This is preferable in that the effect of the adhesive used can be significantly exhibited.

[0118] In the present invention, the ITO electrode film is made of a polyethylene terephthalate (PET) substrate. The PET side of the film has a thin film formed on it, and the PET The substrate and polycarbonate (PC) film are laminated, and then an acrylic film is laminated. It is also preferable to form an optical laminate having a structure in which the layers are made of ITO electrode film, PET substrate, and adhesive. Adhesive layer / PC film / acrylic film).

[0119] Examples of the release sheet include the various synthetic resin sheets, paper, cloth, etc., exemplified above as the base material. Nonwoven fabrics that have been subjected to release treatment can be used. Among them, the following release sheets are available: It is preferable to use a silicone-based release sheet.

[0120] The thickness of the substrate is preferably, for example, 1 to 1000 μm, and particularly preferably The thickness is preferably 2 to 500 μm, and more preferably 3 to 300 μm.

[0121] The pressure-sensitive adhesive composition can be applied by, for example, a gravure roll coater or a reverse roll coater. Roll coater, kiss roll coater, dip roll coater, bar coater, knife coater A coater, a spray coater, a comma coater, or the like may be used.

[0122] As for the drying conditions after coating the pressure-sensitive adhesive composition, the drying temperature is preferably 60 to 140° C. The drying temperature is preferably 80 to 120° C., and more preferably 80 to 120° C. The drying time is preferably 0.5 to 30 minutes. The time is preferably 1 to 5 minutes.

[0123] The conditions for the above curing treatment are usually room temperature (23℃) to 70℃, and the time is usually 1 to 3 hours. 0 days, specifically, for example, 1 to 20 days at 23°C, preferably 3 to 14 days at 23°C. The incubation may be performed under conditions such as at 40° C. for 1 to 10 days.

[0124] The thickness of the adhesive layer of the above-mentioned pressure-sensitive adhesive sheet and the substrate-less double-sided pressure-sensitive adhesive sheet is 2 to 5 It is preferable that the thickness is 1000 μm, particularly preferably 5 to 300 μm, and further preferably 1000 μm. If the thickness of the pressure-sensitive adhesive layer is too thin, the adhesive strength tends to decrease. If the coating is too thick, it will be difficult to apply evenly and problems such as air bubbles will occur in the coating. When considering shock absorption, it is preferable to set the thickness to 50 μm or more. I wish.

[0125] The thickness of the adhesive layer was measured using a digital indicator (Mitutoyo Corporation, ID-C1 12B), the thickness of the components other than the adhesive layer was calculated from the measured thickness of the entire adhesive sheet. This value is obtained by subtracting the measured value.

[0126] The gel fraction of the pressure-sensitive adhesive layer is preferably 10% by weight or more from the viewpoints of durability and adhesive strength. It is particularly preferably 15 to 80% by weight, and further preferably 20 to 70% by weight. If the gel fraction is too low, the cohesive strength decreases, which tends to decrease durability. If the gel fraction is too high, there is a concern that the adhesive strength will decrease due to an increase in cohesive strength.

[0127] The gel fraction is an index of the degree of crosslinking and is calculated, for example, by the following method. That is, a pressure-sensitive adhesive layer is formed on a polymer sheet (e.g., PET film, etc.) that serves as a substrate. The adhesive sheet (without a separator) is wrapped in a 200 mesh SUS wire net. The adhesive was wrapped in a paper and immersed in toluene at 23°C for 24 hours. The weight of the adhesive component before immersion was calculated. The weight percentage of the undissolved adhesive component remaining in the wire mesh after the treatment is taken as the gel fraction. The weight of the

[0128] Furthermore, such a pressure-sensitive adhesive sheet may be provided with a release sheet on the outer side of the pressure-sensitive adhesive layer, if necessary, to prevent adhesion. The adhesive layer may be protected. In addition, in a PSA sheet in which the PSA layer is formed on one side of the substrate, The surface of the substrate opposite to the pressure-sensitive adhesive layer is subjected to a release treatment, and the release-treated surface is used to It is also possible to protect the pressure-sensitive adhesive layer.

[0129] The pressure-sensitive adhesive of the present invention can be used for bonding various members, among which It is preferable to use the adhesive as a pressure-sensitive adhesive for optical members for bonding optical members. The pressure-sensitive adhesive layer of the pressure-sensitive adhesive composition is laminated on the optical member, thereby An optical member with an adhesive layer can be obtained.

[0130] Such optical members include inorganic and organic conductive films such as ITO electrode films and polythiophene. Transparent electrode films, polarizing plates, retardation plates, elliptical polarizing plates, optical compensation films, brightness enhancement films, Electromagnetic wave shielding film, near infrared absorbing film, AR (anti-reflection) film Among these, it is effective when the optical member is a transparent electrode film, and has a high It is preferable in that it has adhesive strength, and an ITO electrode film is particularly preferable. The film is often formed as a thin film on a substrate such as glass or PET. As mentioned in the previous article, a film in which an ITO electrode film is formed as a thin film on a PET substrate is used. It is particularly preferred. In addition, it is used for light extraction films that are provided on the light-emitting surface of the surface emitter of an organic EL element, and for liquid crystal displays. It is also suitable as a light diffusion sheet for play.

[0131] The optical member with the pressure-sensitive adhesive layer may further include a release film on the surface of the pressure-sensitive adhesive layer opposite to the optical member surface. When the adhesive is put into practical use, the release film is peeled off and the adhesive is removed. The adhesive layer is attached to the adherend. As the release film, a silicone-based release film is used. It is preferable to use 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 Weight basis is meant. In addition, regarding the glass transition temperature of the polyester resin [I] in the following examples, The measurements were carried out according to the method described above.

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

[0134] <Production of polyester resin [I]> The mole percentages of each component of the polyvalent carboxylic acid (A) described in the following production examples are The molar ratios are shown when the total amount of the phosphoric acids (A) is taken as 100 mol %. The mole percentages of each component of the polyol (B) described in the following production examples are The molar ratio is shown when the total amount of (B) is taken as 100 mol %.

[0135] [Production of polyester resin [I-1]] A reactor equipped with a heater, thermometer, stirrer, distillation column, nitrogen inlet tube, and vacuum device. Polyvalent carboxylic acids (A) are 76.6 parts of isophthalic acid, 186.5 parts of sebacic acid, 173.6 parts of zeaic acid, 14.3 parts of ethylene glycol as polyol (B), 349 parts of hexanedimethanol, 0.04 parts of germanium dioxide as a catalyst, The internal temperature was gradually raised to 250° C., and the esterification reaction was carried out for 4 hours. After that, the internal temperature was raised to 270°C, the pressure was reduced to 1.33 hPa, and the polycondensation reaction was carried out for 3 hours. A polyester resin [I-1] was produced. The resulting polyester resin [I-1] had a glass transition temperature of -25°C and a weight average molecular weight of The final component ratio was 60,000. Phthalic acid / sebacic acid / azelaic acid=20 mol% / 40 mol% / 40 mol%, polyol (B) Ethylene glycol / cyclohexanedimethanol = 8 mol% / 92 mol %.

[0136] [Ultraviolet absorber] [II-1]: Triazine-based UV absorber (BASF, "Tinuvin 460", water Acid value 178mgKOH / g, hydroxyl equivalent 315, number average molecular weight 630, maximum absorption wavelength 3 49 nm) [II-2]: Triazole-based UV absorber (BASF, "Tinuvin 384-2 ", hydroxyl value 124KOH / g, hydroxyl equivalent 451.6, number average molecular weight 451.6, maximum Absorption wavelength: 345 nm [II'-1]: Benzophenone-based UV absorber (BASF, "Uvinul3050 ", hydroxyl value 912KOH / g, hydroxyl equivalent 61.5, number average molecular weight 246, maximum absorption wave length 346nm)

[0137] [Hydrolysis inhibitor [III]] [III-1]: Polyethylene glycol monomethyl ether-derived isocyanate terminal Substituted aromatic polycarbodiimide compounds (Nisshinbo Chemical Co., Ltd., "Carbodiimide" Zillite V-04PF

[0138] [Crosslinking agent [IV]] [IV-1]: Trimethylolpropane / tolylene diisocyanate adduct (manufactured by Tosoh Corporation, "Coronate L55E")

[0139] [Urethanization catalyst [V]] [V-1]: Zirconium-based compound (pine) diluted with acetylacetone to a solid content of 1% "Orgatics ZC-150" manufactured by Moto Fine Chemical Co., Ltd.)

[0140] [Silane coupling agents [VI]] [VI-1]: 3-glycidoxypropyltrimethoxysilane (Shin-Etsu Silicone Co., Ltd., "K BM-403"

[0141] Example 1 The polyester resin [I-1] obtained above was diluted with toluene to a solid content of 50%. The polyester resin [I-1] solution (100 parts as solids) was subjected to ultraviolet absorption 3 parts of hydrolysis inhibitor [II-1], 1.5 parts of hydrolysis inhibitor [III-1], and 2 parts of crosslinker [IV-1]. 25 parts (solid content), urethane catalyst [V-1] 0.02 parts (solid content), silane coupling 0.1 parts of the binder [VI-1] was added and stirred and mixed to obtain a pressure-sensitive adhesive composition.

[0142] Example 2 In Example 1, except that 3 parts of the ultraviolet absorber [II-1] was changed to 4 parts of [II-2], In the same manner as in Example 1, a pressure-sensitive adhesive composition was obtained.

[0143] Comparative Example 1 In Example 1, 3 parts of the ultraviolet absorber [II-1] was changed to 1.5 parts of [II'-1]. Other than that, the same procedure as in Example 1 was carried out to obtain a pressure-sensitive adhesive composition.

[0144] Comparative Example 2 The acrylic resin [I'] solution obtained below (100 parts as solids) was subjected to ultraviolet absorbing Collector [II-2] 4 parts, and crosslinker [IV-1] 0.4 parts (solids), silane coupling agent 0.1 parts of the additive [VI-1] was added thereto, and the mixture was stirred and mixed to obtain a pressure-sensitive adhesive composition. [Production of acrylic resin [I']] A four-neck round-bottom flask equipped with a reflux condenser, stirrer, nitrogen gas inlet, and thermometer was Ingredients: 38.8 parts of butyl acrylate, 60 parts of methyl acrylate, hydroxyethyl methacrylate 1.0 part acrylate, 0.2 parts 2-(dimethylamino)ethyl acrylate, and ethyl acetate Charge 60 parts of ethyl acetate and 8 parts of methyl ethyl ketone, heat to reflux, and then add azo as a polymerization initiator. Add 0.5 parts of bisisobutyronitrile (AIBN) and react for 7 hours at ethyl acetate reflux temperature. Then, it was diluted with 98 parts of ethyl acetate and 20 parts of methyl ethyl ketone to obtain acrylic resin [I']. A solution was prepared. The glass transition temperature of the obtained acrylic resin [I'] was -21°C and the weight average molecular weight was 53 The number was 0000.

[0145] Comparative Example 3 In Comparative Example 2, 4 parts of the ultraviolet absorber [II-2] was changed to 1.5 parts of [II'-1]. Except for the above, a pressure sensitive adhesive composition was obtained in the same manner.

[0146] The obtained pressure-sensitive adhesive composition was evaluated as follows. The results are shown in Table 1 below. vinegar.

[0147] <Production of substrate-less double-sided adhesive sheet> The adhesive compositions obtained in the examples and comparative examples were applied to a PET release film having a thickness of 100 μm. Using an applicator, The adhesive layer was dried at 100°C for 4 minutes to obtain an adhesive with a release film having a thickness of 50 μm. I got a seat. Next, the surface of the adhesive layer of the obtained adhesive sheet with a release film is coated with the release film (F α) is a PET release film (Mitsui Chemicals Tocello, S P-PET-01-BU) (Fβ), and cured at 40°C for 7 days. A surface adhesive sheet was obtained.

[0148] <Adhesive sheet evaluation> [Adhesive strength] Peel off the release film (Fβ) from one side of the substrate-less double-sided PSA sheet obtained above. The adhesive layer was then transferred onto a PET film (100 μm) to prepare an adhesive sheet for evaluation. The obtained adhesive sheet for evaluation was cut to a width of 10 mm, and the separator on the other side was peeled off. The exposed adhesive layer was then attached to a non-alkali glass plate (Corning Eagle XG). After that, it was compressed by autoclaving (50°C, 0.5 MPa, 20 minutes) and the PET film was A test piece having a structure of film / adhesive layer / non-alkali glass plate was prepared. The above test pieces were subjected to a tensile test using a thermostatic chamber equipped tensile tester (Shimadzu Corporation, Autograph AG-X 50N) at 23℃×50%RH, peeling speed 60mm / min, 180 The peel strength was measured and evaluated according to the following criteria. The results are shown in Table 1. (Evaluation Criteria) ○ Greater than 5N / 10mm △: More than 3N / 10mm and 5N / 10mm or less ×...3N / 10mm or less

[0149] [Adhesion to substrate] Peel off the release film (Fβ) from one side of the substrate-less double-sided PSA sheet obtained above. The adhesive layer was transferred onto a PET film (100 μm) to prepare an adhesive sheet for evaluation. The obtained adhesive sheet for evaluation was cut to a width of 10 mm, and the separator on the other side was peeled off. The exposed adhesive layer was then attached to a non-alkali glass plate (Corning Eagle XG). After that, it was compressed by autoclaving (50°C, 0.5 MPa, 20 minutes) and the PET film was A test piece having a structure of film / adhesive layer / non-alkali glass plate was prepared. The above test pieces were subjected to a tensile test using a thermostatic chamber equipped tensile tester (Shimadzu Corporation, Autograph AG-X 50N) at 23℃×50%RH, peeling speed 60mm / min, 180 The peeling mode when the peel strength was measured was evaluated according to the following criteria. The results are shown in Table 1. Also shown. (Evaluation Criteria) ○...Adherent interface peeling × Substrate interface peeling or cohesive failure

[0150] [Yellowing resistance] Peel off the release film (Fβ) from one side of the substrate-less double-sided PSA sheet obtained above. The adhesive layer was transferred to a non-alkali glass plate (Corning Eagle XG) and the other Peel off the release film (Fα) from the surface and test the adhesive layer / alkali-free glass structure. The obtained test pieces were measured using a color difference meter (SE6000, manufactured by Nippon Denshoku Industries Co., Ltd.). Using b * The values ​​were measured and evaluated according to the following criteria. The results are shown in Table 1. (Evaluation Criteria) ○ 2 or less × 2 or more

[0151] [UV absorption capacity] Peel off the release film (Fβ) from one side of the substrate-less double-sided PSA sheet obtained above. The adhesive layer was transferred to a non-alkali glass plate (Corning Eagle XG) and the other Peel off the release film (Fα) from the surface and test the structure of adhesive layer / non-alkali glass. The obtained test pieces were measured using an ultraviolet, visible, near infrared spectrophotometer (JASCO Corporation, V -7200) was used to measure the UV transmittance (%) at 380 nm, and the following criteria were used: The results are shown in Table 1. (Evaluation Criteria) ○ 5% or less △ More than 5% and 10% × More than 10%

[0152] [Table 1]

[0153] From the results in Table 1 above, it can be seen that the pressure-sensitive adhesive compositions of Examples 1 and 2 have excellent adhesive strength and adhesion to substrates. It can be seen that, despite the high temperature, there is little yellowing and the UV absorption ability is excellent. In contrast, the adhesive composition of Comparative Example 1 had the following adhesive strength, substrate adhesion, and ultraviolet absorbing ability: However, yellowing was observed and the performance as a pressure-sensitive adhesive for optical members was poor. In addition, in Comparative Examples 2 and 3 in which an acrylic resin was used, the adhesion to the substrate was poor. However, depending on the type of UV absorber, the adhesive strength, yellowing resistance, and UV absorption capacity are not particularly distinguished. This also shows that the adhesive composition containing the polyester resin has It is clear that the combination with an ultraviolet absorber is extremely important. [Industrial Applicability]

[0154] The pressure-sensitive adhesive composition of the present invention has excellent adhesive strength and adhesion to substrates, and is less prone to yellowing and purple coloring. It has excellent ultraviolet radiation absorption ability, and therefore adhesives and adhesive sheets using it are In the case of optical members such as optical films and substrates that compose the plates, the attachment of the optical members It can be suitably used for combining purposes.

Claims

1. 1. A polyester-based pressure-sensitive adhesive composition comprising a polyester-based resin [I] (excluding polyester-based resins having a glass transition temperature in the range of -80 to 0°C and having a hydroxyl group and / or a carboxyl group in a side chain) containing a structural unit derived from a polyvalent carboxylic acid (A) and a structural unit derived from a polyol (B), and an ultraviolet absorber [II], wherein the polyester-based resin [I] contains a structural unit derived from an aliphatic dicarboxylic acid (A-2) having 4 or more carbon atoms as a structural unit derived from the polyvalent carboxylic acid (A), the content of the structural unit derived from the aliphatic dicarboxylic acid (A-2) having 4 or more carbon atoms being 40 to 100 mol % of the structural unit derived from the polyvalent carboxylic acid (A), and the ultraviolet absorber [II] is an ultraviolet absorber having a hydroxyl value of 900 mgKOH / g or less.

2. 2. The polyester-based pressure-sensitive adhesive composition according to claim 1, wherein the polyester-based resin [I] has a glass transition temperature (Tg) of -70 to 20°C.

3. 3. The polyester-based pressure-sensitive adhesive composition according to claim 1, wherein the ultraviolet absorber [II] has a number average molecular weight of 180 to 1,500.

4. The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 3, characterized in that the ultraviolet absorber [II] has a maximum absorption wavelength in the range of 300 to 395 nm.

5. The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 4, wherein the ultraviolet absorber [II] is at least one selected from the group consisting of triazine-based compounds and triazole-based compounds.

6. The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 5, further comprising a hydrolysis inhibitor [III].

7. The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 6, further comprising a crosslinking agent [IV].

8. A pressure-sensitive adhesive obtained by crosslinking the polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 7.

9. A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive according to claim 8.

10. 10. The pressure-sensitive adhesive sheet according to claim 9, comprising a substrate and a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer being provided on at least one surface of the substrate.

11. 10. The pressure-sensitive adhesive sheet according to claim 9, which is a substrateless type pressure-sensitive adhesive sheet having no substrate.

12. The pressure-sensitive adhesive sheet according to any one of claims 9 to 11, which is used for bonding optical members.

13. 9. An optical member with a pressure-sensitive adhesive layer, comprising a pressure-sensitive adhesive layer and an optical member, the pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive according to claim 8.

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