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

Abstract

To provide a polyester-based adhesive composition which is hardly yellowed and is excellent in ultraviolet absorption performance while having excellent adhesive strength and substrate adhesion, an adhesive, an adhesive sheet, and an optical member with an adhesive layer.SOLUTION: A polyester-based adhesive composition includes: a polyester resin [I] including a structural unit derived from polyvalent carboxylic acids (A), and a structural unit derived from a polyol (B); and an ultraviolet absorber [II], wherein the ultraviolet absorber [II] is at least one selected from the group consisting of a triazine-based compound, a triazole-based compound, and a cyanoacrylate-based compound.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. Regarding optical materials, more specifically, we have excellent adhesive strength and adhesion to substrates, little yellowing, and ultraviolet resistance. 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 components. [Background technology]

[0002] Plasma displays (PDP), liquid crystal displays (LCD), organic EL displays OLED, Electrophoretic Display (EPD), Interferometric Modulation Display (IMOD) The image display device is composed of various components. In order to bond and integrate the above, adhesives or adhesive sheets are used. In touch panel displays, the surface protection panel, touch panel, image display panel, etc. When components for an image display device are used and these components are laminated, adhesive or adhesives are used. The sheet is 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 that attaches 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, (C) homopolymer with a glass transition temperature (Tg) of 50°C or higher and (C) a (meth)acrylic acid ester represented by the specific formula: Or contains a hydrophilic monomer whose homopolymer glass transition temperature (Tg) is 10°C or less It contains a copolymer of the monomer 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] Japanese Patent Application Laid-Open No. 2010-163591 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 are acrylic adhesives containing acrylic resins. Since the fat itself is soft, improvements are required in terms of impact resistance. Designing acrylic resins to be hard results in reduced adhesive strength and poor adhesion to substrates.

[0006] In recent years, with the trend towards lighter and thinner displays, touch panels have been incorporated into LCD pixels. In addition to the in-cell method, which incorporates the panel electrodes, Touch panels that have been obtained by lamination, such as the on-cell method, which provides touch panel functionality by providing electrodes, The touch-on lens system is a structure 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 th-cell have been proposed, In the touch-on-lens system, a single adhesive material is used to connect the surface protection panel and the LCD. The functions required for attaching the surface protection panel and LCD module The functions required for adhesion to the surface must be achieved with a single adhesive sheet or adhesive. The above functions are required. In particular, display module manufacturers are In addition to the film, there are also functional films such as polarizing films and retardation films that are laminated together to create light. Optical functions can also be directly incorporated into the LCD module or other components, reducing the number of components as much as possible. It is expected that the simplification of functional layers such as functional films and changes in module configuration will The pressure-sensitive adhesive sheet is also required to have ultraviolet blocking properties to protect these functional layers.

[0007] Therefore, in this invention, under such circumstances, as an adhesive to replace acrylic resins, Made of polyester resin, it has excellent adhesive strength and adhesion to the substrate, but also has little yellowing and UV absorption. The object of the present invention is to provide a polyester-based pressure-sensitive adhesive composition having excellent yield. Furthermore, the present invention also aims 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 a specific ultraviolet absorber, the adhesive strength can be improved. A polyester adhesive with excellent adhesion to substrates, minimal yellowing, and excellent UV absorption. The present invention has been accomplished by finding that a composition can be obtained.

[0009] That is, the present invention provides a polymerizable composition comprising a polycarboxylic acid (A)-derived structural unit and a polyol (B)-derived structural unit. and an ultraviolet absorber [II], The ultraviolet absorber [II] is a triazine compound, a triazole compound, or a cyanoacrylate. a first polyester-based pressure-sensitive adhesive composition, which is at least one selected from the group consisting of acrylate-based compounds; The summary is as follows.

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

[0011] In the present invention, the ultraviolet absorber to be contained in the polyester resin is an ultraviolet absorbing agent. Not just any agent will do, but only certain specific ultraviolet absorbers are considered. It has been found that the combination with polyester resin is good. If there is one, it is a benzophenone-based compound ultraviolet absorber in that it has excellent ultraviolet absorption ability in the long wavelength region. However, instead of benzophenone compounds, triazine a compound selected from the group consisting of acrylate-based compounds, triazole-based compounds, and cyanoacrylate-based compounds; By blending at least one type of UV absorber, the adhesive strength is surprisingly not impaired. The object of the present invention is achieved by providing an ultraviolet ray absorbing agent having excellent long wavelengths and excellent resistance to yellowing. This was what was possible. [Effects of the Invention]

[0012] The polyester-based pressure-sensitive adhesive composition of the present invention comprises a structural unit derived from a polycarboxylic 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 a triazine-based compound, a triazole-based compound, or the like. and cyanoacrylate compounds. Excellent adhesion and substrate adhesion, minimal yellowing, and excellent UV absorption and is particularly useful as a pressure-sensitive adhesive for optical members. DETAILED DESCRIPTION OF THE INVENTION

[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 carboxylic acid salts, carboxylic acids, 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 It 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 resin. The essential component is an ultraviolet absorber [II], and the components are a hydrolysis inhibitor [III] and a cross-linking 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 component constituting the pressure-sensitive adhesive composition of the present invention will be explained below in order.

[0015] <Polyester resin [I]> The polyester resin [I] is usually made of polycarboxylic 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 polycarboxylic acid (A), The resulting polymer has structural units derived from the polyol (B).

[0016] [Polycarboxylic acids (A)] The polycarboxylic acids (A) used as constituent raw materials of the polyester resin [I] Examples of the carboxylic acid include dicarboxylic acids and tricarboxylic or higher polycarboxylic acids. Dicarboxylic acids are preferably used because they allow the ester resin [I] to be obtained stably.

[0017] Examples of the dicarboxylic acids include malonic acids, dimethylmalonic acids, and succinic acid. , glutaric acids, adipic acids, trimethyl adipic acids, pimelic acids, 2,2-di Methylglutaric acids, azelaic acids, sebacic acids, fumaric acids, maleic acids, ita carboxylic 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, Naphthalenedicarboxylic acids such as phthalenedicarboxylic acids and 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, pyrometacarboxylic acids, and the like. Examples thereof include ric acids, adamantanetricarboxylic acids, and trimesic acids. These polycarboxylic acids (A) can be used alone or in combination of two or more. .

[0018] Among the polycarboxylic acids (A), those which reduce the crystallinity of the polyester resin [I] are preferred. From this viewpoint, aromatic polycarboxylic 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 Among them, carboxylic acids and 2,7-naphthalenedicarboxylic acids are preferred in terms of reactivity. 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 polycarboxylic 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 may decrease at high temperatures, or the resin may crystallize, resulting in insufficient adhesive performance. 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 a compound having a property of improving initial adhesive strength (tack). From the viewpoint of improving the solubility of the compound, aliphatic dicarboxylic acids having 4 or more carbon atoms (including the carbon atom of the carboxyl group) are used. It is preferable to contain (A-2), and among these, adipic acid, azelaic acid, and sebacic acid are preferred. Contains aliphatic dicarboxylic acids with 6 to 12 carbon atoms (including the carbon atom of the carboxyl group), such as is more preferred.

[0021] The content of the aliphatic dicarboxylic acids (A-2) having 4 or more carbon atoms is 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 It is 40 to 85 mol %, and particularly preferably 50 to 80 mol %. If the content is too low, If the temperature is too high, the glass transition temperature of the polyester resin [I] will be too high, and sufficient adhesive strength will not be obtained. If the content is too high, the adhesive strength at high temperatures may decrease and the resin may break down. It tends to crystallize and not provide sufficient adhesive properties.

[0022] In the present invention, from the viewpoint of adhesive properties, asymmetric aromatic polycarboxylic acids (A) are used. aliphatic dicarboxylic acids (A-1) and aliphatic dicarboxylic acids (A-2) having 4 or more carbon atoms In this case, the asymmetric aromatic dicarboxylic acid (A-1) and the asymmetric aromatic dicarboxylic acid (A-2) having the same number of carbon atoms are preferably used in combination. The content ratio (molar ratio) of the 4 or more aliphatic dicarboxylic acids (A-2) is (A-1) / (A-2). −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], a trivalent The above polycarboxylic acids (A-3) can also be used, and among them, those which are relatively easy to gel during production can be used. It is preferable to use trimellitic acids because they are less likely to undergo oxidation.

[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% by weight of the polycarboxylic acids (A) as a whole. The content is preferably 0 mol % or less, particularly preferably 0.1 to 5 mol %. If the content is too high, the polymer 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 propanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, 2-methyl 2,2-dimethyl-1,3-propanediol (Neopentyl-1,3-propanediol) butyl 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, Aliphatic alcohols such as 5-pentanediol and 2,2,4-trimethyl-1,6-hexanediol diol; 1,2-Cyclohexanedimethanol, 1,3-Cyclohexanedimethanol, 1,4 -Cyclohexanedimethanol, spiroglycol, tricyclodecane dimethanol, Damantanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, etc. Alicyclic diols; 4,4'-Thiodiphenol, 4,4'-Methylenediphenol, 4,4'-Dihydroxy Sulfophenyl, o-, m-, and p-dihydroxybenzene, 2,5-naphthalenediol p-Xylenediol, p-xylenediol, and their ethylene oxide adducts and propylene glycol and aromatic diols such as oxide adducts. Furthermore, fatty acid esters derived from castor oil, oleic acid, erucic acid, etc. Examples of the dimer diol and glycerol monostearate include dimer diol and glycerol monostearate. Examples of the trihydric or higher polyols include pentaerythritol, dipentaerythritol, and the like. Erythritol, tripentaerythritol, glycerin, trimethylolpropane, Methylolethane, 1,2,4-butanetriol, 1,2,5-pentanetriol , 1,2,6-hexanetriol, 1,3,6-hexanetriol, adamantane Lior and others. 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 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 linear structure and having 2 to 18 carbon atoms. Particularly preferred are ethylene glycol, 1,3-propanediol, 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 more preferably 4 to 60 mol %, and particularly preferably 5 to 50 mol %. If the amount is too small, it tends to be difficult to obtain 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 hydroxyl group include dipropylene glycol, 2,4- Dimethyl-2-ethylhexane-1,3-diol, 2-methyl-1,3-propanedio 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2- Methyl-2-ethyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1,3-butyl Tandanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1, Examples include aliphatic diols with branched structures 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 It is preferably 5 to 100 mol %, particularly 20 to 90 mol %, and further preferably 4 If the content is too low, the resin may crystallize and become filled. If the content is too high, it tends to be difficult to obtain sufficient adhesive properties. In the production of the vinyl resin [I], the reaction time tends to be long.

[0031] Among the polyols (B), those capable of breaking down crystallinity and increasing the elastic modulus are From this viewpoint, it is preferable to contain a diol (B-3) having an alicyclic structure. Examples of the diol (B-3) having an alicyclic structure include 1,2-cyclohexanedimethano 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, Pyroglycol, Tricyclodecane Dimethanol, Adamantanediol, 2,2,4, Examples 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 is 2% based on the total amount of the polyol (B). It is preferably 0 to 100 mol %, particularly 40 to 98 mol %, and further preferably 60 to 95 If the content is too low, the resin will crystallize and will not have sufficient adhesion. There is a tendency that it is difficult to obtain the desired performance, and the modulus of elasticity decreases, resulting in a decrease in impact resistance. If this is the case, the reaction time in the production of the polyester resin [I] tends to become longer.

[0033] Furthermore, in the present invention, the polyester resin [I] is reacted with a crosslinking agent [IV] described later. In order to form stress points and increase cohesion, trivalent or higher polyols ( 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 relatively less likely to produce gel. Preferred.

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

[0035] The polyester resin [I] used in the present invention is a mixture of the above polycarboxylic acid (A) and a polycarboxylic acid (B). and an alcohol (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 polycarboxylic acid (A) and the polyol (B) is as follows: It is preferable that the amount of polyol (B) is 1 to 2 equivalents per equivalent of polyol (A), and particularly preferable. If the blending ratio of polyol (B) is too low, the acid value becomes high. If the temperature is too high, the yield tends 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-based catalysts such as tetrahydrofuran, germanium-based catalysts such as germanium dioxide, and zinc acetate catalysts. Examples of catalysts include lead, manganese acetate, and dibutyltin oxide. Among these, the most popular is Benzene because of its balance of high catalytic activity and color. , antimony trioxide, tetrabutyl titanate, germanium dioxide, and zinc acetate are preferred. 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 particularly preferable that the concentration is 10 to 5000 ppm, and further preferably 20 to 3000 ppm. If the blending amount is too small, the polymerization reaction tends to proceed insufficiently. However, 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, more preferably 220 to 260°C. If the temperature is too low, the reaction will not proceed sufficiently, and if it is too high, side reactions such as decomposition will occur. In addition, the pressure during the reaction is usually normal pressure.

[0041] After the esterification reaction, a polycondensation reaction is carried out. The reaction conditions for the polycondensation reaction are as follows: the same catalyst as that used in the above esterification reaction is used; The reaction temperature is preferably 220 to 280°C, particularly preferably 230 The reaction temperature is set to 270°C, and the reaction system is gradually reduced in pressure until the reaction is finally carried out at 5 hPa or less. If the reaction temperature is too low, the reaction tends to proceed insufficiently, and if the reaction temperature is too high, side reactions such as decomposition tend to occur easily.

[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 polycarboxylic acid (A), and and polyol (B), but the aromatic polycarboxylic acids, particularly non- The structural unit derived from the symmetrical aromatic dicarboxylic acid (A-1) is derived from the polycarboxylic acid (A). When the structural unit of the aromatic dicarboxylic acid (A-1) is included, the structure derived from the unsymmetrical aromatic dicarboxylic acid (A-2) The units preferably account for 1 to 90 mol % of the structural units derived from the polycarboxylic acids (A). , particularly preferably 5 to 80 mol %, more preferably 10 to 70 mol %, and further preferably It is preferably 15 to 60 mol %, more preferably 20 to 50 mol %. If this occurs, the adhesive strength may decrease at high temperatures, 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 contained as a structural unit derived from carboxylic acids (A), it is an aliphatic dicarboxylic acid having 4 or more carbon atoms. The structural units derived from the polycarboxylic acids (A-2) are 5 to 100 times the structural units derived from the polycarboxylic acids (A). % by mole, more preferably 20 to 95 mol %, and even more preferably 30 to 95 mol %. 90 mol %, particularly preferably 40 to 85 mol %, and particularly preferably 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 will not be obtained. Adhesive strength at high temperatures tends to decrease, and the resin tends to crystallize, making it difficult to achieve sufficient adhesive performance. be.

[0045] The structural unit derived from the trivalent or higher polyvalent carboxylic acid (A-3) is ), when it is contained as a structural unit derived from trivalent or higher polyvalent carboxylic acids (A-3), The structural units preferably account for 10 mol % or less of the structural units derived from the polycarboxylic acids (A). It is preferable that the content is 0.1 to 5 mol %. If the content is too high, the polyester may become brittle. The vinyl resin [I] tends to gel during production.

[0046] In addition, the structural unit derived from the linear aliphatic diol (B-1) is When included as a structural unit derived from a linear aliphatic diol (B-1), The units preferably account for 1 to 100 mol % of the structural units derived from the polyol (B), and more preferably More preferably, it is 2 to 80 mol %, further preferably, it is 3 to 70 mol %, and particularly preferably, it is 4 to 6 0 mol %, and particularly preferably 5 to 50 mol %. If the content is too low, the poly The reactivity of the ester 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.

[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 contained as a structural unit derived from diol (B), it is -2)-derived structural units 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 more 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 adhesive strength of the polyester resin tends to decrease. The reactivity of the fat [I] during production tends to decrease.

[0048] Furthermore, the structural unit derived from the diol (B-3) having an alicyclic structure is When included as a structural unit derived from a diol (B-3) having an alicyclic structure, The units preferably account for 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 ratio is too low, the resin will crystallize, making it difficult to obtain sufficient adhesive performance and reducing the elastic modulus. If the content is too high, the polyester-based The reaction time in the production of the resin [I] tends to be long.

[0049] In addition, the structural unit derived from the trivalent or higher polyol (B-4) is derived from the polyol (B). When the structural unit derived from the trivalent or higher polyol (B-4) is contained as a structural unit of The amount of the structural units 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 proportions (compositional proportions) of structural units derived from each component of the polyester resin [I] are 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 -60 to 10°C. Preferably, the glass transition temperature is -40 to -5°C, and particularly preferably -30 to -10°C. If the Tg is too high, the flexibility will be lost, the initial adhesive strength will decrease, and the adhesive strength will become weaker with pressure equivalent to finger pressure. If the temperature is too low, the cohesive strength will decrease and the adhesive sheet will not adhere well. This tends to make the product more susceptible to deformation and spoil 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 in terms of the cohesive strength of the adhesive. 000 to 300000, preferably 8000 to 200000, and particularly preferably is 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 the heat resistance and mechanical properties will be poor. 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], gelation occurs easily, making it difficult to obtain a resin, and furthermore, adhesion to the substrate is poor. There is a tendency for it to decrease.

[0054] The weight average molecular weight in the present invention is the weight average molecular weight converted into the molecular weight of standard polystyrene. 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 bottle of Y APC XT 200 and two bottles of 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. It is particularly preferably 3 mgKOH / g or less, and further preferably 1 mgKOH / g or less. If the acid value is too high, hydrolysis tends to proceed more easily, and the adhesive layer may have metal or other impurities on one side. For example, when a metal oxide thin film layer is bonded to a metal substrate, the layer tends to corrode. When such a structure is used, corrosion occurs and the conductivity of the metal oxide thin film tends to decrease.

[0056] The acid value of the polyester resin [I] is determined 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 contained. By virtue of this, the pressure-sensitive adhesive composition of the present invention has excellent adhesive strength and substrate adhesion, while exhibiting little yellowing. It has the effect of being excellent in ultraviolet absorption ability. In the case of acrylic resins that are generally used as adhesive compositions, Even if the specific ultraviolet absorber [II] is contained in the adhesive composition, the above-mentioned effect can be obtained. The present invention does not achieve all of the above effects. When these are selectively combined, the above effects, particularly yellowing resistance and ultraviolet absorption ability, are achieved. It has been found that excellent effects can be obtained.

[0058] The specific ultraviolet absorber [II] may be a triazine-based compound, a triazole-based compound, or and cyanoacrylate compounds.

[0059] Examples of the triazine compounds include 2-(2-hydroxy-4-methoxyphenyl)-2-propanol. 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 (Benzyloxyphenyl)-4,6-diphenyl-1,3,5-triazine, 2,4-bis (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 [(2,4-dimethylphenyl)-4,6-bis(2-hydroxy ... -1,3,5-triazine, 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyl] 4,6-bis(2,4-dimethylphenyl)-2-hydroxyphenyl)-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-octyloxy 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) (2,4-dimethylphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazolidine These may be used alone or in combination of two or more. They may be used in combination. Among them, 2,4-bis(2-hydroxy-4-butoxyphenyl) )-6-(2,4-dibutoxyphenyl)-1,3-5-triazine is preferred.

[0060] Commercially available triazine compounds include, for example, "Tinuvin" manufactured by BASF. 400", "Tinuvin405", "Tinuvin460", "Tinuvin4 77" and "Tinuvin479".

[0061] Examples of the triazole compounds include 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)phenylbenzotriazole 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chloro Benzotriazole, 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl 2-(2-hydroxybenzotriazol-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 bis(4-octoxyphenyl)benzotriazole, 2,2'-methylenebis(4-octoxyphenyl)benzotriazole 2,2'-p-phenylenebis(1,3-benzotriazolephenyl) 2-[2-hydroxy-3-(3,4,5,6-tetrahydro- benzotriazolidinol (5-methylphenyl)benzotriazole, etc. 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.

[0062] Commercially available triazole compounds include, for example, "Tinuvi" manufactured by BASF. nPS”, “Tinuvin99-2”, “Tinuvin326”, “Tinuvin 384-2", "Tinuvin900", "Tinuvin928", "Tinuvi n970" and "Tinuvin1130".

[0063] Examples of the cyanoacrylate compounds include 2-ethylhexyl-2-cyanoacrylate. -3,3-diphenylacrylate, ethyl-2-cyano-3,3-diphenylacrylate acrylate, octyl-2-cyano-3,3-diphenylacrylate, etc. may be used alone or in combination of two or more.

[0064] Commercially available cyanoacrylate compounds include, for example, "Uvi" manufactured by BASF. Examples include "nul3035", "Uvinul3039", and "Uvinul3030". do.

[0065] Among the above UV absorbers [II], this has better adhesive strength, less yellowing, and is UV resistant. In view of their excellent absorption capacity, triazine compounds and triazole compounds are preferred.

[0066] 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.

[0067] The ultraviolet absorber [II] preferably has a maximum absorption wavelength of 300 to 395 nm. It is more preferable that the wavelength is 320 to 390 nm, and more preferably 330 to 380 nm. is particularly preferred, and it is especially preferred that the ultraviolet absorber has a wavelength of 340 to 370 nm. If the maximum absorption wavelength of is too short, the ultraviolet absorption performance in the long wavelength range tends to decrease. If the absorption wavelength is too long, the yellowing resistance tends to decrease.

[0068] The content of the ultraviolet absorber [II] is 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 adhesive strength tends to decrease, and if the amount is too small, the ultraviolet absorbing performance tends to decrease.

[0069] <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 to ensure long-term durability.

[0070] As the hydrolysis inhibitor [III], a conventionally known one can be used, for example, Examples of the compound include a compound that reacts with the carboxylic acid terminal group of the polyester resin [I] to bond thereto. Specifically, functional groups such as a carbodiimide group, an epoxy group, an oxazoline group, etc. The hydrolysis inhibitor [III] may be used alone or in combination. The above compounds can be used in combination. Among them, the carbodiimide group-containing compound is preferably a carboxylic acid terminal compound. This is preferred in that it is highly effective in eliminating the catalytic activity of the protons derived from the terminal groups.

[0071] The carbodiimide group-containing compound is generally a compound having a carbodiimide group (-N=C=N- ) in the molecule, but at higher temperatures In order to improve durability under high humidity, compounds containing two or more carbodiimide groups in the molecule, 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. 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.

[0072] The carbodiimide group-containing compound is a compound which is prepared by reacting a diisocyanate compound 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

[0073] Such high molecular weight polycarbodiimides may be synthesized or commercially available products may be used. When synthesizing a high molecular weight polycarbodiimide, for example, the following diisocyanate is derivatized: Examples include those obtained by carbonic acid condensation reaction.

[0074] 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 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.

[0075] Furthermore, the terminal isocyanate groups of the high molecular weight polycarbodiimide are blocked with a blocking agent. In terms of storage stability, those which react with isocyanate groups are preferred. Examples include compounds having active hydrogen atoms or compounds having an isocyanate group. For example, a carboxylic acid having one substituent selected from a carboxy group, an amino group, and an isocyanate group. Monoalcohols, monocarboxylic acids, monoamines, and monoisocyanates are Examples include:

[0076] 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 has excellent properties.

[0077] The carbodiimide equivalent of the carbodiimide group-containing compound is preferably 50 to 100 00, particularly 100 to 1000, and further preferably 150 to 500. The carbodiimide equivalent weight indicates the chemical formula weight per carbodiimide group.

[0078] 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.

[0079] Specific examples of the glycidyl ester compound include, for example, benzoic acid glycidyl ester, t-Bu-benzoic acid glycidyl ester, p-toluic acid glycidyl ester, cyclohexane Xanthan Glycidyl Ester, Pelargonic Acid Glycidyl Ester, Stearic Acid Glycidyl ester, lauric acid glycidyl ester, palmitic acid glycidyl ester , Behenic acid glycidyl ester, Versatic acid glycidyl ester, Glyceryl oleate Glycidyl ester, linoleic acid glycidyl ester, linolenic acid glycidyl ester, Glycidyl ester of hydroxybenzoate, glycidyl ester of stearolic acid, diglyceryl terephthalate Glycidyl ester, diglycidyl isophthalate, diglycidyl phthalate , Naphthalenedicarboxylic acid diglycidyl ester, Methyl terephthalic acid diglycidyl ester ter, hexahydrophthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester Esters, cyclohexanedicarboxylic acid diglycidyl ester, adipate diglycidyl Esters, succinic acid diglycidyl ester, sebacic acid diglycidyl ester, dodecane Dicarboxylic acid diglycidyl ester, octadecanedicarboxylic acid diglycidyl ester, triglyceride Examples include mellitic acid triglycidyl ester and pyromellitic acid tetraglycidyl ester. These can be used alone or in combination of two or more.

[0080] Specific examples of the glycidyl ether compound include, for example, phenyl glycidyl ether, o-Phenylglycidyl ether, 1,4-bis(β,γ-epoxypropoxy)butane , 1,6-bis(β,γ-epoxypropoxy)hexane, 1,4-bis(β,γ-epoxypropoxy)hexane 1-(β,γ-epoxypropoxy)benzene, 1-(β,γ-epoxypropoxy)-2-ethoxyethane, 1-(β,γ-epoxypropoxy)-2-benzyloxyethane, 2,2-bis-[ -(β,γ-epoxypropoxy)phenyl]propane, and 2,2-bis-(4-hydroxyphenyl)propane Bis-(hydroxyphenyl)propane and 2,2-bis-(4-hydroxyphenyl)methane Examples include bisglycidyl polyethers obtained by the reaction of phenol with epichlorohydrin. These can be used alone or in combination of two or more.

[0081] 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 ether) methyl-2-oxazoline), 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-oxazoline) 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 include diphenylenebis(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.

[0082] It is preferable that the hydrolysis inhibitor [III] has low volatility. It is preferable to use a polymer having a high average molecular weight, usually 300 to 10,000, preferably 1 Use one between 000 and 5000. In addition, 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. Preferably, it is 2000 or more, more preferably 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. If the molecular weight is too large, the compatibility with the polyester resin [I] tends to decrease. be.

[0083] 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] will be poor, causing turbidity. If the amount is too small, it tends to be difficult to obtain sufficient durability.

[0084] 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 ratio of the total mole number (a) of the acidic functional groups in the ester resin to the total mole number (a) of the polyester-based pressure-sensitive adhesive composition The molar ratio of the total number of moles (b) of the functional groups of the hydrolysis inhibitor [III] in the , 0.5≦(b) / (a) is preferred, and 1≦(b) / (a)≦ 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, cohesion and durability tend to decrease.

[0085] <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], such as a polyester resin [I] Among these, compounds with functional groups that react with one another are those with high initial adhesive strength and mechanical strength. Polyisocyanate compounds are particularly preferred because they offer a good balance of mechanical strength and heat resistance. It is preferable that

[0086] Examples of such polyisocyanate compounds include tetramethylene diisocyanate. Hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate Diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate Xylylene diisocyanate, hydrogenated xylylene diisocyanate, tetramethyl Silylene diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane Polyisocyanates such as triisocyanate are also included. and polyol compounds such as trimethylolpropane, and Examples of the biuret and isocyanurate compounds of the anate compounds are as follows. Isocyanate compounds are compounds in which the isocyanate moiety is blocked with phenol, lactam, etc. These crosslinking agents [IV] can be used alone or in combination. Alternatively, two or more types may be used in combination.

[0087] 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 carboxyl group contained in the polyester resin [I]. The reactive group contained in the crosslinking agent [IV] is 0.2 times the equivalent of at least one of the hydroxy 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 number of equivalents of the reactive groups contained in the crosslinking agent [IV] is too small, the cohesive strength tends to decrease. If it is too large, flexibility tends to decrease.

[0088] In addition, in the reaction between the polyester resin [I] and the crosslinking agent [IV], and organic solvents that do not have a functional group that reacts with component [IV], such as ethyl acetate and butyl acetate. esters such as methyl ethyl ketone and methyl isobutyl ketone; ketones such as toluene; Organic solvents such as aromatics such as benzene and xylene can be used. Two or more types can be used in combination.

[0089] <Urethanization 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.

[0090] Examples of the organometallic compounds include zirconium compounds, iron compounds, tin compounds, and the like. Examples of compounds include titanium compounds, lead compounds, cobalt compounds, and zinc compounds. can. Examples of zirconium compounds include zirconium naphthenate and zirconium acetate. Examples include ethyl acetonate. Examples of iron compounds include iron acetylacetonate and iron 2-ethylhexanoate. Examples include: Examples of tin compounds include dibutyltin dichloride, dibutyltin oxide, and dibutyltin. tin dilaurate and the like. Examples of titanium compounds include dibutyltitanium dichloride and tetrabutyltitanium. butoxytitanium trichloride, and the like. Examples of lead compounds include lead oleate, lead 2-ethylhexanoate, lead benzoate, Examples include lead naphthenate. Examples of cobalt compounds include cobalt 2-ethylhexanoate and cobalt benzoate. Examples include: Examples of zinc compounds include zinc naphthenate and zinc 2-ethylhexanoate. can be done.

[0091] Examples of the tertiary amine compound include triethylamine and triethylenediamine. amine, 1,8-diazabicyclo-(5,4,0)-undecene-7, and the like.

[0092] Among these urethane catalysts [V], the following are the most suitable 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.

[0093] [Catalytic inhibitor] The pressure-sensitive adhesive composition of the present invention has the advantages of extending the pot life and improving the coating properties. It is preferable that the urethanization catalyst [V] contains a catalytic inhibitor. Examples of catalytic inhibitors include methyl acetoacetate, ethyl acetoacetate, and acetoacetic acid. β-ketoacetate such as octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, and stearyl acetoacetate β-esters such as acetylacetone, 2,4-hexanedione, and benzoylacetone These are keto-enol tautomeric compounds, and these are the same as those mentioned above. By protecting the urethanization catalyst [V], the catalytic activity of the urethanization catalyst [V] in solution can be improved. This reduces the viscosity of the adhesive composition, suppressing excessive viscosity increase and gelation of the adhesive composition after blending, and The pot life of the composition can be extended. Among these, from the viewpoint of the balance between pot life and curing speed, It is preferable to use acetylacetone as the catalyst inhibitor. Two or more of these can be used in combination.

[0094] The blending ratio (weight ratio) of the catalyst inhibitor and the urethane catalyst [V] is The thanilation 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 content of the catalyst inhibitor is too low compared to the content of the urethane catalyst [V], If too much is used, the curing speed tends to decrease. do.

[0095] <Silane coupling agents [VI]> The pressure-sensitive adhesive composition of the present invention preferably further contains a silane coupling agent [VI]. It's nice. Examples of the silane coupling agent [VI] include amino group-containing silane coupling 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, These may be used alone or in combination. More than one species may be used in combination.

[0096] Examples of the amino group-containing silane coupling agent include 3-aminopropyltrimethylsilane. Triethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)amino Examples include 3-aminopropyltrimethoxysilane and 3-phenylaminopropyltrimethoxysilane. It can be obtained.

[0097] Examples of the epoxy group-containing silane coupling agent include 3-glycidoxypropyl 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, Glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane , 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and the like.

[0098] Examples of the vinyl group-containing silane coupling agent include vinyltriacetoxysilane. Examples of the silane include vinyltrimethoxysilane, vinyltriethoxysilane, and the like.

[0099] Examples of the (meth)acryloyl group-containing silane coupling agent include 3-(meth)acryloyl groups. ) Acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyl Dimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 3-( meth)acryloxypropyltriethoxysilane and the like.

[0100] Examples of the mercapto group-containing silane coupling agent include 3-mercaptopropionyl 3-mercaptotrimethoxysilane, 3-mercaptomethyldimethoxysilane, 3-mercaptotriethoxysilane Examples include thoxysilane.

[0101] Examples of the isocyanate group-containing silane coupling agent include tris-(trimethylsilyl)-2-isocyanate. Silane coupling agents containing isocyanurate groups, such as hydroxysilylpropyl isocyanurate Examples of suitable silane include silane blockers, 3-isocyanatepropyltriethoxysilane, and the like.

[0102] Among these silane coupling agents, epoxy group-containing silane coupling agents are preferred. Of these, 3-glycidoxypropyltrimethoxysilane is particularly preferred.

[0103] 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 0.03 to 3 parts by weight, and further preferably, it is 0.1 to 1 part by weight. If the content of silane coupling agent [VI] is too high, the adhesive strength tends to decrease. If the thickness is too large, the adhesion to the substrate tends to decrease.

[0104] In the pressure-sensitive adhesive composition of the present invention, the polyester resin [I], the ultraviolet absorber In addition to the 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 this range, antioxidants such as hindered phenols, softeners, and UV absorbers other than those listed above are not included. additives such as binders, stabilizers, antistatic agents, tackifiers, and other inorganic or organic fillers, Powders such as metal powders and pigments, and particulate additives can be added. Two or more types can be used in combination.

[0105] In addition to the additives, the adhesive composition of the present invention also contains other components for the adhesive composition. It may contain a small amount of impurities contained in the raw materials.

[0106] Such a pressure-sensitive adhesive composition may comprise, for example, the above-mentioned polyester resin [I], an ultraviolet absorber [ II] and optional ingredients as needed, and blend them when manufacturing polyester resin [I] Polyester resin [I] solution obtained by dispersing or dissolving in an organic solvent and dispersing the mixture using a mixing roller.

[0107] The pressure-sensitive adhesive of the present invention is made of the pressure-sensitive adhesive composition, i.e., The composition is crosslinked (cured).

[0108] 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 a substrate-less 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 car seat. In the present invention, the term "sheet" includes "film" and "tape." do.

[0109] <Adhesive sheet> The pressure-sensitive adhesive sheet can be produced, for example, as follows. Such a pressure-sensitive adhesive sheet can be manufactured by a method according to a known general method for manufacturing a pressure-sensitive adhesive sheet. For example, the pressure-sensitive adhesive composition can be applied to one surface of a substrate, followed by drying, A pressure-sensitive adhesive layer is formed, and a release sheet is attached to its surface (the surface opposite to the surface that contacts the substrate). By further curing, it is possible to obtain a film having a substrate and a pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer is attached to at least one side of the substrate. Thus, the pressure-sensitive adhesive sheet of the present invention is obtained.

[0110] Alternatively, the pressure-sensitive adhesive composition is applied to a release sheet and dried to form a pressure-sensitive adhesive layer; A substrate is attached to the surface (the side opposite to the release sheet) and cured as necessary. The pressure-sensitive adhesive sheet of the present invention can also be obtained.

[0111] In addition, a pressure-sensitive adhesive layer is formed on a release sheet, and its surface (the surface opposite to the surface in contact with the release sheet) By laminating the release sheet and another release sheet to the substrate, a substrate-less It is possible to produce a substrate-less double-sided PSA sheet of this type.

[0112] When using the obtained pressure-sensitive adhesive sheet or substrate-less double-sided pressure-sensitive adhesive sheet, the release sheet is adhered to the sheet. The adhesive layer is peeled off and the adhesive layer is stuck to the adherend.

[0113] 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 cellulose Cellulose resins such as cellulose and cellophane; polymethyl methacrylate, polymethacrylic acid Acrylic resins such as polyethyl acrylate, polyethyl acrylate, polybutyl acrylate, etc.; Polycarbonate; Polyarylate; Polyimide; Cycloolefin polymer, etc. Synthetic resin sheet; Metal foils such as aluminum, copper, and iron; Paper such as fine paper and glassine paper; Examples include woven fabrics and nonwoven fabrics made of glass fibers, natural fibers, synthetic fibers, etc. These substrates can be used as a single layer or as a multi-layer structure in which two or more types are laminated. can.

[0114] 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, polyethylene terephthalate having a thin metal layer is used to separate the substrate and the adhesive. 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.

[0115] In the present invention, the ITO electrode film is formed on a polyethylene terephthalate (PET) substrate. The adhesive layer is attached to the PET side of the film on which a thin film is formed, and the PET The base material and polycarbonate (PC) film are laminated together, and then an acrylic film is laminated on top of them. It is also preferable to use an optical laminate having layers (layer structure: ITO electrode film / PET substrate / adhesive). Adhesive layer / PC film / acrylic film).

[0116] Examples of the release sheet include the various synthetic resin sheets, paper, cloth, and the like exemplified above as the substrate. Nonwoven fabrics that have been treated with a release agent can be used. Among them, silicone-based release agents are preferred. It is preferable to use a phosphate.

[0117] The thickness of the substrate is preferably, for example, 1 to 1000 μm, and particularly preferably Preferably, it is 2 to 500 μm, and more preferably, it is 3 to 300 μm.

[0118] The pressure-sensitive adhesive composition can be applied by, for example, a gravure roll coater or a reverse roll coater. Roll coater, kiss roll coater, dip roll coater, bar coater, knife coater A coater, spray coater, comma coater, or the like may be used.

[0119] 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.

[0120] The conditions for the above curing treatment are usually room temperature (23℃) to 70℃, and the time is usually 1 to 3 hours. 0 days, specifically, for example, 1 to 20 days at 23°C, preferably 3 to 14 days at 23°C. The incubation may be carried out under conditions such as 1 to 10 days at 40°C.

[0121] 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 00μm, particularly preferably 5 to 300μm, and further preferably 10 If the thickness of the 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 impact absorption, it is preferable to set the thickness to 50 μm or more. I wish.

[0122] The thickness of the adhesive layer was measured using a Digimatic Indicator (Mitutoyo Corporation, ID-C1 12B), the thickness of the components other than the adhesive layer was calculated from the measured thickness of the entire adhesive sheet. This value is obtained by subtracting the measured value.

[0123] The gel fraction of the pressure-sensitive adhesive layer is preferably 10% by weight or more from the viewpoint 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 force 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.

[0124] The gel fraction is a measure of the degree of crosslinking and is calculated, for example, by the following method. That is, a pressure-sensitive adhesive layer is formed on a polymer sheet (e.g., PET film) that serves as a base material. The adhesive sheet (without a separator) is wrapped in a 200 mesh SUS wire mesh. The adhesive was wrapped in a plastic bag and immersed in toluene at 23°C for 24 hours. The weight of the adhesive component before immersion was calculated based on the weight of the adhesive component after immersion. The weight percentage of the undissolved adhesive component remaining in the wire mesh after the treatment is taken as the gel fraction. The weight of the

[0125] Furthermore, such a pressure-sensitive adhesive sheet may be provided with a release sheet on the outside of the pressure-sensitive adhesive layer, if necessary, to prevent adhesion. In addition, in the case of a PSA sheet in which the PSA layer is formed on one side of the substrate, By subjecting the surface of the substrate opposite to the pressure-sensitive adhesive layer to a release treatment, the release-treated surface can be used to It is also possible to protect the adhesive layer by using the adhesive layer.

[0126] The pressure-sensitive adhesive of the present invention can be used to bond various members together, among which: It is preferable to use it as a pressure-sensitive adhesive for optical members to be used for bonding optical members. By laminating and forming a pressure-sensitive adhesive layer of a pressure-sensitive adhesive composed of a pressure-sensitive adhesive composition on an optical member, An optical element with an adhesive layer can be obtained.

[0127] 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 particularly effective when the optical member is a transparent electrode film. In particular, an ITO electrode film is preferable because it can provide high adhesive strength. The TO electrode film is often formed as a thin film on a substrate such as glass or PET. As mentioned above, the film is a thin film of ITO electrode film formed on a PET substrate. It is particularly preferred to use It is also used for light extraction films that are attached to the light-emitting surface of the surface emitter of organic EL elements, and for LCDs. It is also suitable as a light diffusion sheet for play.

[0128] The optical member with the pressure-sensitive adhesive layer may further include a release film on the surface of the pressure-sensitive adhesive layer opposite to the optical member surface. When the adhesive is put into practical use, the release film is peeled off and the adhesive layer is The adhesive layer is pasted onto the adherend. As the release film, a silicone-based release film is used. It is preferable to use [Example]

[0129] The present invention will be explained in more detail below with reference to examples, but the present invention will not go beyond the gist of the invention. The present invention is not limited to the following examples unless otherwise specified. All values ​​are by weight unless otherwise specified. In addition, regarding the glass transition temperature of the polyester resin [I] in the following examples, Measurement was carried out according to the method described above.

[0130] Prior to the examples, the following components were prepared.

[0131] [Production of polyester resin [I]] The molar percentages of each component, which is a polycarboxylic acid (A) described in the following production examples, are The molar ratio is shown when the total amount of the phosphoric acids (A) is taken as 100 mol %. In addition, the mole percentages of each component of the polyol (B) described in the following production examples are the same as those of the polyol (B). The molar ratio is shown when the total amount of (B) is taken as 100 mol %.

[0132] [Polyester resin [I-1]] A reactor equipped with a heater, a thermometer, a stirrer, a rectification column, a nitrogen inlet tube, and a vacuum device was installed. Polycarboxylic acids (A) include 76.6 parts of isophthalic acid, 186.5 parts of sebacic acid, 186.5 parts of azeotropic acid, 173.6 parts of ethylene glycol as polyol (B), 14.3 parts of cyclohexane 349 parts of hexanedimethanol and 0.04 parts of germanium dioxide as a catalyst were charged. The temperature was gradually raised to 250°C, and the esterification reaction was carried out over 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 over 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 ratio of the components in the final product was 60,000. Phthalic acid / sebacic acid / azelaic acid = 20 mol% / 40 mol% / 40 mol%, polyol Ethylene glycol / cyclohexanedimethanol = 8 mol% / 92 mol as (B) %.

[0133] [Ultraviolet absorber [II]] [II-1]: Triazine-based UV absorber (BASF, "Tinuvin 460") Average molecular weight 630, maximum absorption wavelength 349nm) [II-2]: Triazole-based UV absorber (BASF, "Tinuvin 384-2 ", number average molecular weight 451.6, maximum absorption wavelength 345nm) [II'-1]: Benzophenone-based ultraviolet absorber (BASF, "Uvinul 3050") , number average molecular weight 246, maximum absorption wavelength 346nm)

[0134] [Hydrolysis inhibitor [III]] [III-1]: Isocyanate-terminated polyethylene glycol monomethyl ether-derived Substituted aromatic polycarbodiimide compounds (Nisshinbo Chemical Co., Ltd., "Carbodiimide") Zillite V-04PF

[0135] [Crosslinking agent [IV]] [IV-1]: Trimethylolpropane / tolylene diisocyanate adduct (manufactured by Tosoh Corporation, "Coronate L55E")

[0136] [Urethanization catalyst [V]] [V-1]: Zirconium-based compound (pine) diluted with acetylacetone to a solid concentration of 1% Moto Fine Chemical Co., Ltd., "Orgatics ZC-150")

[0137] [Silane coupling agents [VI]] [VI-1]: 3-glycidoxypropyltrimethoxysilane (Shin-Etsu Silicone Co., Ltd., "K BM-403

[0138] Example 1 The polyester resin [I-1] obtained above was diluted with toluene to a solids concentration of 50%. , the polyester resin [I-1] solution (100 parts as solids) was subjected to ultraviolet absorption 3 parts of agent [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 adhesive [VI-1] was added, and the mixture was stirred and mixed to obtain a pressure-sensitive adhesive composition.

[0139] Example 2 In Example 1, except that 3 parts of the ultraviolet absorber [II-1] was changed to 4 parts of [II-2], A pressure-sensitive adhesive composition was obtained in the same manner as in Example 1.

[0140] (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.

[0141] (Comparative Example 2) The acrylic resin [I'] solution obtained below (100 parts as solids) was subjected to ultraviolet absorption. Collector [II-2] 4 parts, and crosslinker [IV-1] 0.4 parts (solids), silane coupling agent 0.1 parts of the agent [VI-1] was added, 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, a stirrer, a nitrogen gas inlet, and a thermometer was Ingredients: 38.8 parts of butyl acrylate, 60 parts of methyl acrylate, hydroxyethyl methacrylate acrylate 1.0 part, 2-(dimethylamino)ethyl acrylate 0.2 part, and ethyl acetate Charge 60 parts of methyl ethyl ketone and 8 parts of methyl ethyl ketone, and after heating and refluxing, 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 It was 0000.

[0142] (Comparative Example 3) In Comparative Example 2, 4 parts of the ultraviolet absorber [II-2] was changed to 1.5 parts of [II'-1]. A pressure-sensitive adhesive composition was obtained in the same manner as above.

[0143] The resulting adhesive composition was evaluated as follows, and the results are shown in Table 1 below. .

[0144] <Production of substrate-less double-sided adhesive sheets> The pressure-sensitive adhesive compositions obtained in the examples and comparative examples were applied to a 38 μm-thick PET release film. An applicator was used on a film (Mitsui Chemicals Tocello, SP-PET-03-BU) (Fα). The adhesive layer is then applied to the adhesive sheet with a release film and dried at 100°C for 4 minutes. Got a sheet. Next, the surface of the adhesive layer of the obtained adhesive sheet with a release film was coated with the release film (F α) is a 38 μm thick PET release film (Mitsui Chemicals Tocello, S P-PET-01-BU) (Fβ), and cured at 40°C for 7 days. A pressure-sensitive adhesive sheet was obtained.

[0145] <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 transferred onto a PET film (100 μm) to prepare an adhesive sheet for evaluation. The obtained adhesive sheet for evaluation was cut into a width of 10 mm, and the separator on the other side was peeled off. The exposed adhesive layer was then attached to an alkali-free glass plate (Corning Eagle XG). After that, autoclave treatment (50°C, 0.5 MPa, 20 minutes) was performed to compress the PET film. 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°C x 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

[0146] [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 into a width of 10 mm, and the separator on the other side was peeled off. The exposed adhesive layer was then attached to an alkali-free glass plate (Corning Eagle XG). After that, autoclave treatment (50°C, 0.5 MPa, 20 minutes) was performed to compress the PET film. 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°C x 50% RH, peeling speed 60mm / min, 180 The peeling mode when measuring the peel strength was evaluated according to the following criteria. The results are shown in Table 1. Also shown. (Evaluation criteria) ○...Adherent interface peeling ×...Interface peeling or cohesive failure of substrate

[0147] [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 onto a non-alkali glass plate (Corning, Eagle XG), and the other Peel off the release film (Fα) on 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

[0148] [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 onto a non-alkali glass plate (Corning, Eagle XG), and the other Peel off the release film (Fα) on the surface and test the adhesive layer / alkali-free glass structure. The obtained test pieces were measured using an ultraviolet-visible-near infrared spectrophotometer (JASCO Corporation, V -7200) to measure the ultraviolet transmittance (%) at 380 nm, and The results are also shown in Table 1. (Evaluation criteria) ○ 5% or less △: More than 5% and less than 10% × More than 10%

[0149] [Table 1]

[0150] From the results in Table 1 above, it can be seen that the pressure-sensitive adhesive compositions of Examples 1 and 2 are excellent in adhesive strength and substrate adhesion. It can be seen that the film exhibits little yellowing and excellent ultraviolet absorption. In contrast, the adhesive composition of Comparative Example 1 had no adhesive strength, substrate adhesion, or UV absorption ability. However, yellowing was observed, and the adhesive was inferior in performance as an adhesive for optical members. In addition, in Comparative Examples 2 and 3, which used acrylic resin, the adhesion to the substrate was poor. There was no particular difference in adhesive strength or UV absorption ability depending on the type of UV absorber. For this reason, in the pressure-sensitive adhesive composition containing a polyester resin, it is necessary to use an ultraviolet absorber. It is clear that the combination of [Industrial Applicability]

[0151] The pressure-sensitive adhesive composition of the present invention has excellent adhesive strength and adhesion to substrates, and is less likely to yellow and purple. It has excellent ultraviolet radiation absorption ability, and therefore adhesives and adhesive sheets using it are In optical components such as plates and optical films and substrates that compose them, the adhesion of the optical components It can be suitably used for combining purposes.

Claims

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 and having a hydroxyl group and / or a carboxyl group in the 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 ultraviolet absorber [II] is at least one selected from the group consisting of a triazine-based compound and a triazole-based compound.

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 number-average molecular weight of the ultraviolet absorber [II] is 180 to 1,500.

4. 4. The polyester-based pressure-sensitive adhesive composition according to claim 1, wherein 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, further comprising a hydrolysis inhibitor [III].

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

7. A pressure-sensitive adhesive obtained by crosslinking the polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 6.

8. A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive according to claim 7.

9. 9. The adhesive sheet according to claim 8, comprising a substrate and an adhesive layer, the adhesive layer being provided on at least one surface of the substrate.

10. 9. The pressure-sensitive adhesive sheet according to claim 8, which is a substrate-less type pressure-sensitive adhesive sheet having no substrate.

11. The pressure-sensitive adhesive sheet according to any one of claims 8 to 10, which is used for bonding optical members.

12. 8. An optical member with a pressure-sensitive adhesive layer, comprising a pressure-sensitive adhesive layer and an optical member, wherein the pressure-sensitive adhesive layer contains the pressure-sensitive adhesive according to claim 7.

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