Polyester-based resin composition, adhesive composition, 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 resin composition which is excellent in adhesive force under a high temperature condition, has a small change in haze even under a high temperature and high humidity condition, and is excellent in moisture heat resistance.SOLUTION: A polyester-based resin composition contains a polyester-based resin [I] having a glass transition temperature of -40 to 30°C, and a polycarbodiimide-based compound [II] in which at least one terminal isocyanate group in one molecule is substituted with a substituent derived from a hydrophilic organic compound (α), wherein the hydrophilic organic compound (α) is at least one selected from an oxyalkylene structure-containing compound, a hydroxy polyester structure-containing compound, a hydroxyalkylsulfonic acid structure-containing compound, a dialkylaminoalcohol structure-containing compound, a hydroxycarboxylic acid alkyl ester structure-containing compound, and a dialkylaminoalkylamine structure-containing compound.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyester resin composition, an adhesive composition, a pressure-sensitive adhesive composition, a pressure-sensitive adhesive , pressure-sensitive adhesive sheets and optical components with pressure-sensitive adhesive layers, and more specifically, It has excellent adhesive strength in high temperature and high humidity conditions, and the haze change of the pressure-sensitive adhesive layer is small even under high temperature and high humidity conditions. Polyester resin composition, adhesive composition, pressure-sensitive adhesive composition, and pressure-sensitive adhesive composition having excellent wet heat resistance The present invention relates to an adhesive, a pressure-sensitive adhesive sheet, and an optical member with a pressure-sensitive adhesive layer. [Background technology]

[0002] Conventionally, polyester resins are produced by combining a polycarboxylic acid component and a polyol component. This is known to result in excellent chemical resistance and mechanical strength, and is a pressure-sensitive adhesive. It is also useful in the field of pharmaceuticals. The polyester-based pressure-sensitive adhesive may be, for example, a polyester containing 10 mol % or more of an aromatic carboxylic acid and 50 mol % or more of an aromatic carboxylic acid. % or less by mole of a carboxylic acid component and 5 mol % or more of a glycol having a hydrocarbon group in the side chain and a polyhydric alcohol component containing the same, and having a number average molecular weight of 5000 or more. A pressure-sensitive adhesive obtained using a polyester resin has been proposed, which has excellent adhesive properties, heat resistance, and It is said to have good mechanical strength (see, for example, Patent Document 1). Also, a polyester-based adhesive containing a polyester-based resin (A) and a hydrolysis inhibitor (B) is The adhesive is a polyester resin (A) having a glass transition temperature of -10°C or less. ester-based pressure-sensitive adhesive compositions (see, for example, Patent Document 2), sulfonate group-containing dicarboxylic acids, Polyester resin (containing a predetermined amount of polycarboxylic acids and a polyol component) A polyester-based pressure-sensitive adhesive composition containing A) has been proposed (see, for example, Patent Document 3). There are. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-45914 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-115149 [Patent Document 3] Japanese Patent Application Publication No. 2019-85518 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in recent years, adhesives have become increasingly popular for LCD (Liquid Crystal Display) displays. Display devices such as tal displays and touch screen devices used in combination with the above display devices It is increasingly being used in the manufacture of input devices such as panels, and has excellent adhesive strength even under high temperature conditions. Furthermore, the adhesive exhibits minimal haze change under high temperature and humidity conditions, and has excellent resistance to moisture and heat. is now being demanded. The polyester-based adhesives of Patent Documents 1 to 3 are excellent in adhesiveness, heat resistance, and mechanical strength. However, the performance under high temperature and humidity conditions is not fully satisfactory, and further improvement is required. It is being done.

[0005] Therefore, in this invention, it is necessary to provide a composition having excellent adhesive strength under high temperature conditions and further having excellent adhesive strength under high temperature conditions. Polyester resin composition with excellent humidity and moisture resistance and small haze change even under high temperature and humidity conditions , adhesive composition, pressure-sensitive adhesive composition, pressure-sensitive adhesive, pressure-sensitive adhesive sheet and pressure-sensitive adhesive layer The object of the present invention is to provide an optical element. [Means for solving the problem]

[0006] However, the present inventors have conducted extensive research in light of the above circumstances and have found that polyester resins and a polycarbodiimide compound, The polyester resin has a relatively high transition temperature, and the hydrophilic organic compound By using a polycarbodiimide compound containing a hydrophilic structural portion, pressure-sensitive adhesion is achieved. When used as an adhesive, it has excellent adhesive strength under high temperature conditions, and also has little change in haze even under high temperature and high humidity conditions. It has been found that a polyester resin composition having excellent heat resistance and moisture resistance can be obtained. The invention was completed.

[0007] That is, the present invention provides a polyester resin [I] having a glass transition temperature of -40 to 30°C and At least one of the terminal isocyanate groups in one molecule is derived from a hydrophilic organic compound (α). Polyester-based compounds containing polycarbodiimide-based compounds [II] substituted with the following substituents: The first aspect relates to a resin composition.

[0008] The present invention also provides an adhesive composition containing the polyester resin composition according to a second aspect of the present invention. A third aspect of the present invention is a pressure-sensitive adhesive composition containing the polyester-based adhesive composition, The fourth aspect is a pressure-sensitive adhesive obtained by crosslinking the pressure-sensitive adhesive composition, and The fifth aspect is a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer containing an optical element with a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer comprising a material, A sixth aspect of the present invention is an optical member with a pressure-sensitive adhesive layer containing the adhesive.

[0009] Generally, a carbodiimide compound is added to a polyester resin composition as a hydrolysis inhibitor. It is known that the material contains high molecular weight polycarbonate from the viewpoint of long-term durability. However, the glass transition temperature of polyester resin is When the temperature is relatively high, the compatibility between the polyester resin and the polycarbodiimide compound is low. There was a problem that it was not usable. In the present invention, any carbodiimide compound is acceptable. At least one of the terminal isocyanate groups in one molecule is a substituent derived from a hydrophilic organic compound. By selecting and using a polycarbodiimide compound substituted with The objective was achieved. Usually, at least one of the terminal isocyanate groups in one molecule is a substituent derived from a hydrophilic organic compound. When a polycarbodiimide compound substituted with a substituent is used, the hydrophilic structural moiety However, the adhesive strength may be reduced due to the use of certain polyesters. At least one of the terminal isocyanate groups in one molecule of the resin is a hydrophilic organic compound. By using a polycarbodiimide compound substituted with a substituent derived from It has excellent adhesive strength under high temperature conditions and is compatible with polyester resins with high glass transition temperatures. It has good solubility, little haze change under high temperature and humidity conditions, and excellent resistance to humidity and heat. This is what we discovered. [Effects of the Invention]

[0010] The polyester resin composition of the present invention is a polyester resin having a glass transition temperature of -40 to 30°C. A cellulose-based resin [I] and a polymer having at least one terminal isocyanate group in one molecule, which is hydrophilic and organically modified. Since it contains a polycarbodiimide compound [II] substituted with a compound, it has a pressure-sensitive adhesive When used as an adhesive, it has excellent adhesive strength under high temperature conditions, and also has little change in haze even under high temperature and high humidity conditions. It has excellent heat and humidity resistance and is particularly suitable for use as optical components. . DETAILED DESCRIPTION OF THE INVENTION

[0011] 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 adhesive composition includes a pressure-sensitive adhesive composition and a heat-sensitive adhesive composition. This is a concept that can be used for pressure-sensitive adhesive compositions and heat-sensitive adhesive compositions. However, it is particularly effective for use as a pressure-sensitive adhesive composition.

[0012] The polyester resin composition of the present invention (hereinafter sometimes referred to as "resin composition") is Polyester resins with relatively high glass transition temperatures [I] and hydrophilic organic compounds (α a polycarbodiimide [II] substituted with a substituent derived from . Each component constituting the resin composition of the present invention will be explained below in order.

[0013] <Polyester resin [I]> The polyester resin [I] is usually made of polycarboxylic acids (A) and The polyester-based copolymer is obtained by copolymerizing a copolymerization component containing polyol (B). The resin [I] has a resin composition including a structural unit derived from a polycarboxylic acid (A) and a polycarboxylic acid (B). It will have structural units derived from ol (B). In the present invention, the term "carboxylic acids" includes not only carboxylic acids but also carboxylic acids Carboxylic acid derivatives such as salts, carboxylic acid anhydrides, carboxylic acid halides, and carboxylic acid esters It also includes conductors.

[0014] [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.

[0015] Examples of the dicarboxylic acids include: Malonic acids, dimethylmalonic acids, succinic acids, glutaric acids, adipic acids, trime Chiladipic acids, pimelic acids, 2,2-dimethylglutaric acids, azelaic acids, Bacic acids, fumaric acids, maleic acids, itaconic acids, thiodipropionic acids, diglycerides Acyclic aliphatic dicarboxylic acids such as cholic acids and 1,9-nonanedicarboxylic acids, 1,3- Cyclopentanedicarboxylic acids, 1,2-cyclohexanedicarboxylic acids, 1,3-cyclo 1,4-Cyclohexanedicarboxylic acids, 2,5-norbol Aliphatic dicarboxylic acids such as cycloaliphatic dicarboxylic acids, e.g., tetraamantanedicarboxylic acids ... Aliphatic carboxylic acids; Phthalic acids, terephthalic acids, isophthalic acids, benzylmalonic acids, diphenic acids, 4,4'-oxydibenzoic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, Naphthalenedicarboxylic acids such as phthalenedicarboxylic acids and 2,7-naphthalenedicarboxylic acids aromatic dicarboxylic acids such as carboxylic acids; and the like. 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. .

[0016] 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.

[0017] Such aromatic polycarboxylic acids, particularly asymmetric aromatic dicarboxylic acids (A-1), The content is preferably 5 to 100 mol % based on the total amount of the polycarboxylic acids (A). , particularly preferably 20 to 90 mol %, and more preferably 30 to 85 mol %, Particularly preferably, it is 40 to 80 mol %. If the content is too low, the The adhesive strength tends to decrease, the resin crystallizes, and sufficient adhesive performance cannot be obtained. If there is too much, the initial adhesive strength (tack) tends to decrease.

[0018] In the present invention, the polyvalent carboxylic acid (A) is a compound having a function of improving initial adhesive strength (tackiness). From the viewpoint of improving the cyclic aliphatic dicarboxylic acid having 4 or more carbon atoms (including the carbon atom of the carboxyl group), It is preferable to contain a carboxylic acid (A-2), among which carboxylic acids such as azelaic acid and sebacic acid are preferred. Contains acyclic aliphatic dicarboxylic acids with a prime number of 9 to 12 (including the carbon atom of the carboxyl group) is more preferred.

[0019] The content of the acyclic 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 5 to 95 mol %, particularly preferably 10 to 80 mol %, and further preferably The content is preferably 15 to 70 mol %, and particularly preferably 20 to 60 mol %. If the temperature is too high, 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 become brittle. The oil tends to crystallize and not provide sufficient adhesive performance.

[0020] In the present invention, from the viewpoint of adhesive properties, asymmetric aromatic polycarboxylic acids (A) are used. Aliphatic dicarboxylic acids (A-1) and acyclic aliphatic dicarboxylic acids having 4 or more carbon atoms (A-2) It is also preferable to use the asymmetric aromatic dicarboxylic acid (A-1) in combination with the aromatic dicarboxylic acid having 4 or more carbon atoms. The content ratio (molar ratio) of the acyclic aliphatic dicarboxylic acids (A-1) to the acyclic aliphatic dicarboxylic acids (A-2) is (A-1) / (A -2) is preferably 1 / 99 to 90 / 10, and particularly preferably 20 / 80 to 90 / 10, and more preferably 40 / 60 to 80 / 20.

[0021] 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.

[0022] The content of the trivalent or higher polyvalent carboxylic acid (A-3) is, when used as a pressure-sensitive adhesive, In this respect, it is preferable to use the polycarboxylic acids (A) as a whole in order to increase the cohesive strength of the polycarboxylic acids (A). is 10 mol % or less, particularly preferably 0.1 to 5 mol %, and if the content is too high, The polyester resin [I] tends to gel during production.

[0023] [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.

[0024] 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, Acyclic compounds such as 5-pentanediol and 2,2,4-trimethyl-1,6-hexanediol Aliphatic diol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol alcohol, 1,4-cyclohexanedimethanol, spiroglycol, tricyclodecanediol Methanol, Adamantanediol, 2,2,4,4-tetramethyl-1,3-cyclobutene Aliphatic diols such as cycloaliphatic diols such as tandiol; 4,4'-thiodiphenol, 4,4'-methylenediphenol, bisphenol, biphenol phenolfluorene, 4,4'-dihydroxybiphenyl, o-, m- and p-dihydroxybiphenyl Aromatic diols such as hydroxybenzene, 2,5-naphthalenediol, and p-xylenediol oar; and ethylene oxide and propylene oxide adducts thereof. In addition, fatty acid esters derived from castor oil, oleic acid, erucic acid, etc. Examples of suitable glycerol derivatives include dimer diol and glycerol monostearate. Examples of the trihydric or higher polyols include pentaerythritol, dipentaerythritol, and the like. Erythritol, tripentaerythritol, glycerin, trimethylolpropane, Examples include methylolethane, 1,3,6-hexanetriol, and adamantanetriol. It can be obtained. The above polyols (B) can be used alone or in combination of two or more kinds.

[0025] 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 acyclic aliphatic diol (B- 1) is preferably contained, and more preferably, an acyclic straight-chain structure having 2 to 18 carbon atoms. Aliphatic diols are particularly preferred, and diethylene glycol and 1,4-butanediol are particularly preferred. Among them, polyester is the most popular. It is possible to lower the glass transition temperature (Tg) of the ester resin [I], resulting in better adhesive properties. In this respect, 1,4-butanediol and 1,6-hexanediol are particularly preferred.

[0026] The content of the linear acyclic aliphatic diol (B-1) in the total polyol (B) is The content is preferably 1 to 100 mol %, more preferably 3 to 95 mol %, and particularly preferably 5 to 90 % by mole, more preferably 10 to 80 mol %, and particularly preferably 15 to 60 mol %. If the content is too low, it tends to be difficult to obtain a stable resin formation.

[0027] Among the polyols (B), those capable of increasing branching points and disrupting crystallinity are also preferred. From this viewpoint, it is preferable to contain a diol (B-2) having a hydrocarbon group in the side chain. Examples of such diols (B-2) having a hydrocarbon group in the side chain include dipropylene glycol. Recall, 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 ol, 1,3-butanediol, 3-methyl-1,5-pentanediol, 2,2,4 acyclic aliphatic diols with branched structures such as -trimethyl-1,6-hexanediol, , 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4 -Cyclohexanedimethanol, spiroglycol, tricyclodecane dimethanol, Damantanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, etc. and diols derived from oleic acid, erucic acid, etc. Among them, acyclic aliphatic diols having a branched structure are preferred. 2,2-dimethyl-1,3-propanediol (neopentyl glycol) is particularly preferable.

[0028] The content of the diol (B-2) having a hydrocarbon group in the side chain is It is preferably 5 to 95 mol %, more preferably 15 to 85 mol %, and even more preferably 40 If the content is too low, the resin will crystallize and the resulting resin will not be sufficiently soluble. If the amount is too large, it tends to be difficult to obtain satisfactory adhesive performance, and if the amount is too large, The reaction time tends to be longer in this case.

[0029] Furthermore, in the present invention, the polyester resin [I] is mixed with a crosslinking agent [III] described later. Polyol (B) is a trivalent or higher polyol, which forms reactive sites and enhances cohesion. It is preferable to use (B-3), and among these, trimethylolpropane, trimethylol Luetane, Glycerin, Pentaerythritol, 1,2,4-Butanetriol, 1,2 It is preferable to use 1,5-pentanetriol and 1,2,6-hexanetriol. Among these, trimethylolpropane is preferred because it is less likely to produce gel. Particularly preferred.

[0030] The content of the trihydric or higher polyol is 20% based on the total amount of polyol (B). % by mole or less, and more preferably 0.1 to 10% by mole, In particular, 0.5 to 5 mol % is preferable. If the content of such trihydric or higher polyol is too high, This tends to make it difficult to produce the polyester resin [I].

[0031] 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

[0032] 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.

[0033] In the polycondensation reaction, an esterification reaction is carried out first, and then the polycondensation reaction is carried out.

[0034] In such an esterification reaction, a catalyst is used, specifically, for example, tetraisopropyl ether Titanium catalysts such as propyl titanate and tetrabutyl titanate, antimony trioxide, etc. Catalysts such as antimony-based catalysts, germanium-based catalysts such as germanium dioxide, zinc acetate, Examples of catalysts include manganese acetate and dibutyltin oxide, and one or more of these may be used. Among these, three types are used because of their balance of high catalytic activity and color. Antimony oxide, tetrabutyl titanate, germanium dioxide, and zinc acetate are preferred.

[0035] The amount of the catalyst to be added is preferably 1 to 10,000 ppm based on the total amount of copolymerization components. , particularly preferably 10 to 5000 ppm, and further preferably 20 to 3000 ppm. If the amount is too small, the polymerization reaction tends to proceed insufficiently, and if the amount is too large, There is no advantage to shortening the reaction time, and side reactions tend to occur easily.

[0036] 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.

[0037] 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 23 The reaction temperature should be kept between 0 and 270°C, and the reaction system should be gradually reduced in pressure until the reaction is finally carried out at 5 hPa or less. If the reaction temperature is too low, the reaction tends to proceed insufficiently, and if the reaction temperature is too high, If the temperature is too high, side reactions such as decomposition tend to occur.

[0038] Thus, the polyester resin [I] used in the present invention is obtained. The resin [I] has a relatively high glass transition temperature.

[0039] 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 the non-paired The structural unit derived from the aromatic dicarboxylic acid (A-1) is a structural unit derived from the polycarboxylic acid (A). When contained as a structural unit, it is a structural unit derived from an asymmetric aromatic dicarboxylic acid (A-1). The units preferably account for 5 to 100 mol % of the structural units derived from the polycarboxylic acids (A). , particularly preferably 20 to 90 mol %, further preferably 30 to 85 mol %, and further preferably If the content is too low, the adhesive strength at high temperatures will be low. The adhesive strength tends to decrease, or the resin crystallizes, making it difficult to obtain sufficient adhesive performance. If the adhesive is too thick, the initial adhesive strength (tack) tends to decrease.

[0040] The structural unit derived from the acyclic aliphatic dicarboxylic acid (A-2) having 4 or more carbon atoms is a polyvalent When included as a structural unit derived from carboxylic acids (A), acyclic fatty acids having 4 or more carbon atoms The structural unit derived from the aromatic dicarboxylic acid (A-2) is a structural unit derived from the polycarboxylic acid (A). It is preferably 5 to 100 mol %, more preferably 5 to 95 mol % of the above. Preferably, it is 10 to 80 mol %, more preferably 15 to 70 mol %, and especially preferably The content is preferably 20 to 60 mol %. If the content is too low, the polyester resin The glass transition temperature of the resin [I] tends to become too high, making it difficult to obtain sufficient adhesive strength. If the content is too high, the adhesive strength at high temperatures may decrease or the resin may crystallize, resulting in insufficient adhesion. There is a tendency for performance to be compromised.

[0041] 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). If the content is too high, the polyester may be easily degraded. The vinyl resin [I] tends to gel during production.

[0042] The structural unit derived from the linear acyclic aliphatic diol (B-1) is a polyol When it is contained as a structural unit derived from (B), it is a linear acyclic aliphatic polyol (B- The structural units derived from 1) account for 1 to 100 mol % of the structural units derived from polyol (B). is preferred, more preferably 3 to 95 mol %, further preferably 5 to 90 mol %, and particularly preferably The content is preferably 10 to 80 mol %, and particularly preferably 15 to 60 mol %. If the amount is too small, the reactivity of the polyester resin [I] during production tends to decrease. If the content is too high, the polyester resin [I] will crystallize, and the initial adhesion of the pressure-sensitive adhesive will deteriorate. There is a tendency for sexual activity to decrease.

[0043] 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 95 mol % of the structural units derived from polyol (B). is preferable, and it is particularly preferable that it is 15 to 85 mol %, and furthermore preferable that it is 40 to 70 mol %. If the content is too low, the polyester resin [I] will crystallize, and the pressure-sensitive adhesive will The initial adhesive strength tends to decrease, and if the content is too high, the polyester resin [I] Reactivity during production tends to decrease.

[0044] In addition, the structural unit derived from the trivalent or higher polyol (B-3) is a structural unit derived from the polyol (B). When the structural unit is contained as a trivalent or higher polyol (B-3), the structural unit derived from the trivalent or higher polyol (B-3) is 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.

[0045] 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.

[0046] The glass transition temperature (Tg) of the polyester resin [I] is -40 The temperature is preferably from -40 to 20°C, more preferably from -35 to 15°C, and even more preferably from -40 to 20°C. Preferably, -30 to 12°C, particularly preferably -25 to 10°C, and particularly preferably -20 to 5°C. That is, the glass transition temperature of the polyester resin [I] is The glass transition temperature (Tg) is higher than that of the commonly used polyester resins. If the temperature is too high, the adhesive will lose flexibility, the initial adhesive strength will decrease, and the adhesive strength will not be achieved with pressure equivalent to finger pressure. If the viscosity is too low, the cohesive strength will decrease and the pressure-sensitive adhesive sheet However, this tends to cause deformation and spoil the appearance.

[0047] 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.

[0048] The weight average molecular weight of the polyester resin [I] is preferably selected from the viewpoint of the cohesive strength of the pressure-sensitive adhesive. It is preferably 8000 to 200000, and particularly preferably Preferably, it 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 as a pressure-sensitive adhesive, and the heat resistance will be poor. In addition, if the weight average molecular weight is too large, the polyester tends to deteriorate. During the production of the ester resin [I], gelation occurs easily, making it difficult to obtain the resin, and furthermore, Adhesion tends to decrease.

[0049] The weight average molecular weight in the present invention is a weight average molecular weight converted into a standard polystyrene molecular weight. The high-performance liquid chromatograph (Waters, ACQUITY APC System) The column consisted of one ACQUITY APC XT 450 and one ACQUITY A One PC XT 200 and two ACQUITY APC XT 45, a total of four It is measured by using a series of

[0050] The acid value of the polyester resin [I] is preferably 10 mgKOH / g or less. More preferably, 5 KOH / g or less, particularly preferably 3 mg KOH / g or less, and even more preferably Preferably, the acid value is 1 mgKOH / g or less, and particularly preferably 0.5 KOH / g or less. If the adhesive strength is too high, it may corrode a metal layer when it is attached to one side of the pressure-sensitive adhesive layer. For example, when a metal oxide thin film layer is used, corrosion occurs and the metal oxide Furthermore, when the polyester resin composition is prepared, the electrical conductivity of the resulting thin film tends to decrease. , the pot life tends to be shorter.

[0051] The acid value of the polyester resin [I] is determined based on JIS K 0070. It is determined by titration.

[0052] <Polycarbodiimide compounds [II]> The polycarbodiimide compound [II] used in the present invention is an isocyanate-terminated polycarbodiimide. At least one of the terminal isocyanate groups in one diimide molecule is derived from a hydrophilic organic compound (α). The substituents are as follows:

[0053] [Isocyanate-terminated polycarbodiimide] The isocyanate-terminated polycarbodiimide is prepared by condensation reaction of an organic diisocyanate compound. It can be obtained by reacting

[0054] Examples of the organic diisocyanate compound include 1,5-naphthylene diisocyanate. 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane Tanethene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylenediisocyanate Isocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate , a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, Aromatic diisocyanates such as xylylene diisocyanate and tetramethylxylylene diisocyanate Socyanate compounds; Acyclic aliphatic diisocyanates such as hexamethylene diisocyanate, cyclohexane -1,4-Diisocyanate, isophorone diisocyanate, dicyclohexylmethane- 4,4'-Diisocyanate, Methylcyclohexanediisocyanate, 2,5(2,6 )-bis(isocyanatomethyl)bicyclo[2.2.1]heptane and other alicyclic diisocyanates These may be used alone or in combination. The above may be used in combination. Among these, aromatic diisopropyl acrylates are preferred because they can be used to produce pressure-sensitive adhesive compositions with excellent resistance to moist heat. Cyanate compounds are preferred, and tetramethylxylene diisocyanate is more preferred.

[0055] The organic diisocyanate compound is decarboximed in a conventional manner using a known carbodiimide catalyst. By subjecting the compound to an acid condensation reaction, an isocyanate-terminated polycarbodiimide can be obtained. do.

[0056] [Hydrophilic organic compound (α)] The hydrophilic organic compound (α) is a compound obtained by dissolving the terminal of the isocyanate-terminated polycarbodiimide. In addition to the above substituents, Furthermore, it is a compound that has one or more heteroatoms in the molecule.

[0057] Examples of the substituent having an active hydrogen reactive with the isocyanate group include: Acid group, primary amino group, secondary amino group, imino group, isocyanate group, carboxy group, etc. Among these, a hydroxyl group, a primary amino group, a secondary amino group, and an imino group are preferred. These substituents may be contained alone or in combination in the hydrophilic organic compound (α). Good too.

[0058] The number of substituents having active hydrogen reactive with the isocyanate group is determined by the hydrophilic organic compound. The number of the substituents in the compound (α) is usually 2 or less, and preferably 1. It is preferable that the alkyl group is located at the terminal of the reactive organic compound (α).

[0059] The compound has a substituent having an active hydrogen that is reactive with the isocyanate group, and Other compounds having one or more heteroatoms in the molecule include, for example, oxyalkylenes. Compounds containing ethylene structure, compounds containing hydroxypolyester structure, hydroxyalkyl sulfur compounds containing carboxylic acid structure, compounds containing dialkylamino alcohol structure, hydroxycarbo Compounds containing alkyl phosphate ester structure, compounds containing dialkylaminoalkylamine structure Among these, compounds containing an oxyalkylene structure are preferred.

[0060] The end of the hydrophilic organic compound (α) is blocked with an alkoxy group or a phenoxy group. It is preferable that

[0061] Among these, the hydrophilic organic compound (α) is preferably an alkoxy group or a phenoxy group. The compound containing an oxyalkylene structure and having terminals blocked with a group is is also preferable in that the change in haze is small.

[0062] The compound containing an oxyalkylene structure end-blocked with an alkoxy group or a phenoxy group Examples of the substance include a compound represented by the following formula (1). R 1 -O-(CH2-CHR 2 -O) m -H (1) In the above formula (1), R 1 represents an alkyl group having 1 to 4 carbon atoms or a phenyl group, and R 2 is hydrogen It represents an atom or a methyl group, and m is an integer of 4 to 100.

[0063] Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, Examples include an isopropyl group, an n-butyl group, an s-butyl group, an isobutyl group, and a t-butyl group. can be.

[0064] Specific examples of the compound represented by the above formula (1) include polyethylene glycol monomethyl Ether, polyethylene glycol monoethyl ether, polypropylene glycol mono Methyl ether, polypropylene glycol monoethyl ether, polypropylene glycol Among them, polyethylene glycol monomethyl ether and the like are particularly preferred. Diethers are preferred.

[0065] The weight average molecular weight of the hydrophilic organic compound (α) is preferably 200 or more. The upper limit of the weight average molecular weight is usually 5,000. or less, preferably 4000 or less, more preferably 2000 or less, and even more preferably 100 If the weight average molecular weight is too small, the compatibility with the polyester resin [I] may be poor. The haze value tends to decrease and the haze change tends to increase under high temperature and high humidity conditions. If the average molecular weight is too large, the adhesive strength tends to decrease.

[0066] The polycarbodiimide compound [II] used in the present invention is the isocyanate-terminated polycarbodiimide compound [II]. It can be obtained by reacting carbodiimide with the hydrophilic organic compound (α). Cut.

[0067] The reaction between the isocyanate-terminated polycarbodiimide and the hydrophilic organic compound (α) is The isocyanate-terminated polycarbodiimide is heated to a temperature of usually 50 to 200°C, preferably 100 to 180°C. After heating to 80 to 200°C, the hydrophilic organic compound (α) was added, and the mixture was further heated to 80 to 200°C for 0.5 The reaction is carried out for ~5 hours.

[0068] In this way, at least one of the terminal isocyanate groups in one molecule is converted to a hydrophilic organic compound. A polycarbodiimide compound [II] substituted with a substituent derived from compound (α) can be obtained. can.

[0069] The polycarbodiimide compound [II] exhibits little change in haze even under high temperature and high humidity conditions. In view of the fact that a pressure-sensitive adhesive composition having excellent resistance to moist heat can be obtained, aromatic polycarbodiimide is preferred. It is preferable that the compound is a methyl methyl ether compound.

[0070] The degree of polymerization of the polycarbodiimide compound [II] is preferably 2 to 200. It is preferably 2 to 100, more preferably 3 to 50, and 3 It is particularly preferable that the degree of polymerization is 15 or less. If the degree of polymerization is too low, the resistance to moist heat tends to decrease. If it is too large, the compatibility with the polyester resin [I] tends to decrease.

[0071] Commercially available polycarbodiimide compounds [II] include, for example, Nisshinbo Chemical Co., Ltd.'s Carbodilite (registered trademark) V-02B, V-04K, V-04PF, E manufactured by BASF Among them, Carbodilite V-04PF is preferred. stomach.

[0072] The content of the polycarbodiimide compound [II] is 100% of the polyester resin [I]. It is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight. It is more preferable that the amount is 0.2 to 5 parts by weight, and particularly preferable that the amount is 0.3 to 3 parts by weight. It is particularly preferable that the amount is 0.5 to 2 parts by weight, and more preferably 0.5 to 2 parts by weight. If the content of the imide compound [II] is too low, the haze change under high temperature and high humidity conditions will be large. Polycarbodiimide compounds [II] If the content of [I] is too high, the compatibility with the polyester resin [I] tends to decrease.

[0073] The content of the polycarbodiimide compound [II] is It is preferable to optimize the content depending on the acid value of the polyester resin composition. The total number of moles of the acidic groups in the polyester resin [I] (a) is The total number of moles (b) of carbodiimide groups in the polycarbodiimide compound [II] in the composition It is preferable, and particularly preferable, that the ratio [(b) / (a)] is 0.5≦(b) / (a). Preferably, 1≦(b) / (a)≦1000, more preferably 1.5≦(b) / (a)≦100 is. If the molar ratio of (b) to (a) is too low, the haze change under high temperature and high humidity conditions will be large. The moisture and heat resistance performance tends to decrease. If the molar ratio is too high, the compatibility with the polyester resin [I] may decrease, and the adhesive strength and cohesion may decrease. The strength and durability tend to decrease.

[0074] <Crosslinking agent [III]> The resin composition of the present invention comprises the polyester resin [I] and a polycarbodiimide compound It contains [II], but preferably further contains a crosslinking agent [III]. By incorporating the crosslinking agent [III], the polyester resin [I] is crosslinked by the crosslinking agent [III]. This results in excellent cohesive strength and improves the performance as a pressure-sensitive adhesive.

[0075] Examples of such crosslinking agents [III] include polyisocyanate compounds, polyepoxy compounds, At least one of the hydroxyl group and the carboxyl group contained in the polyester resin [I], such as a polyester-based compound Among these, compounds with functional groups that react with either the other are particularly suitable. Polyisocyanate compounds are particularly preferred because they offer a good balance of mechanical strength and heat resistance. It is preferable to use

[0076] 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 triisocyanate, and the like. Adducts of these polyisoprene and polyol compounds such as trimethylolpropane, Examples include biuret and isocyanurate forms of cyanate compounds. Polyisocyanate compounds are compounds in which the isocyanate moiety is blocked with phenol, lactam, etc. These crosslinking agents [III] may be used alone. Alternatively, two or more types may be used in combination.

[0077] The content of the crosslinking agent [III] depends on the molecular weight of the polyester resin [I] and the intended use. The hydroxyl and carboxyl groups contained in the polyester resin [I] can be selected appropriately. For one equivalent of at least one of the hydroxy groups, the reactive group contained in the crosslinking agent [III] is 0. The crosslinking agent [III] is preferably contained in an amount of 2 to 10 equivalents, and particularly preferably 0 The amount is preferably 0.5 to 5 equivalents, and more preferably 0.5 to 3 equivalents. If the number of equivalents of the reactive group contained in the crosslinking agent [III] is too small, the cohesive strength tends to decrease. If it is too large, flexibility tends to decrease.

[0078] The content of the crosslinking agent [III] is 100 parts by weight of the polyester resin [I]. The amount is preferably 0.01 to 15 parts by weight, more preferably 0.1 to 10 parts by weight, and even more preferably Preferably 0.3 to 7 parts by weight, particularly preferably 0.5 to 5 parts by weight, and particularly preferably 1 to 3 parts by weight. It is preferable that the amount is parts by weight. If the amount of the crosslinking agent [III] is too small, the cohesive strength tends to decrease, and if it is too large, the flexibility tends to decrease. This tends to decrease the adhesive strength required.

[0079] The content of the crosslinking agent [III] is 0.1 to 15% by weight of the total active ingredients in the composition. is preferred, more preferably 0.2 to 10% by weight, and even more preferably 0.3 to 7% by weight, Particularly preferably, the content is 0.5 to 5% by weight, and particularly preferably, 1 to 3% by weight. If the amount of the crosslinking agent [III] is too small, the cohesive strength tends to decrease, and if it is too large, the flexibility tends to decrease. This tends to decrease the adhesive strength required.

[0080] In addition, in the reaction between the polyester resin [I] and the crosslinking agent [III], these [I] and [III] an organic solvent having no functional group that reacts with the component, such as ethyl acetate, butyl acetate, etc. esters such as methyl ethyl ketone and methyl isobutyl ketone; ketones such as toluene; Organic solvents such as aromatics such as ene and xylene can be used. Two or more of these can be used in combination.

[0081] <Urethanization catalyst [IV]> The resin composition of the present invention preferably contains a urethanization catalyst [IV] in terms of reaction rate. preferable.

[0082] The urethane catalyst [IV] may be, for example, an organometallic compound, a tertiary amine compound, or the like. These may be used alone or in combination of two or more.

[0083] 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.

[0084] Examples of the tertiary amine compound include triethylamine and triethylenediamine. amine, 1,8-diazabicyclo-(5,4,0)-undecene-7, and the like.

[0085] Among these urethane catalysts [IV], the most popular are those that are suitable for reaction speed and pot life of the pressure-sensitive adhesive layer. Among them, organometallic compounds are preferred, and zirconium compounds are particularly preferred. The nitration catalyst [IV] is preferably used in combination with acetylacetone as a catalytic inhibitor. The inclusion of cetylacetone inhibits catalytic activity at low temperatures, extending the pot life. This is preferable in that

[0086] In the resin composition of the present invention, the polyester resin [I], polycarbodiimide In addition to the imido compound [II], the crosslinking agent [III], and the urethane catalyst [IV], To the extent that it does not impair the properties of the product, hydrolysis inhibitors other than polycarbodiimide compounds [II], Antioxidants such as chlorinated phenols, softeners, UV absorbers, stabilizers, antistatic agents, viscosity enhancers Additives such as adhesion promoters, inorganic or organic fillers, metal powders, pigments, and other powders and particles These may be used alone or in combination of two or more. This can be done.

[0087] In addition to the additives, the resin composition of the present invention may also contain raw materials for producing the constituent components of the resin composition. It may contain small amounts of impurities contained in the above.

[0088] Such a resin composition may be, for example, the above-mentioned polyester resin [I], polycarbodiimide The polyester compound [II] and necessary optional components are prepared, and the polyester resin [I] is produced. Polyester resins [I] prepared by blending and dispersing or dissolving in organic solvents. The resulting mixture can be obtained by mixing it in a solution and dispersing it using a mixing roller.

[0089] The resin composition of the present invention thus obtained is useful as an adhesive composition, particularly a pressure-sensitive adhesive composition, The composition is useful as a heat-sensitive adhesive composition, and is particularly suitable as a pressure-sensitive adhesive composition.

[0090] The pressure-sensitive adhesive according to the present invention is made of the above pressure-sensitive adhesive composition, i.e., The adhesive composition is crosslinked (cured).

[0091] The pressure-sensitive adhesive sheet of the present invention comprises the above-mentioned pressure-sensitive adhesive on one or both sides of a supporting substrate. The pressure-sensitive adhesive sheet has a pressure-sensitive adhesive layer containing the compound, and is particularly suitable for bonding optical components. It is suitable as a pressure-sensitive adhesive sheet for optical members. In the present invention, the term "sheet" includes "film" and "tape." do.

[0092] <Pressure-sensitive 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 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. The adhesive is then dried and crosslinked to form a pressure-sensitive adhesive layer, and the surface (the surface that contacts the substrate) A release sheet is attached to the opposite side of the substrate, and if necessary, cured to allow the pressure-sensitive adhesive to adhere to the substrate. Thus, a pressure-sensitive adhesive sheet of the present invention having a pressure-sensitive adhesive layer containing the adhesive agent is obtained.

[0093] The pressure-sensitive adhesive composition can also be applied to a release sheet, dried, and crosslinked. A pressure-sensitive adhesive layer is formed by laminating a substrate to the surface of the pressure-sensitive adhesive layer (the surface opposite to the surface that contacts the release sheet). If necessary, the pressure-sensitive adhesive sheet of the present invention can be obtained by curing the sheet.

[0094] Furthermore, a pressure-sensitive adhesive layer is formed on the release sheet, and the surface (the surface in contact with the release sheet) By laminating the release sheet and another release sheet on the opposite side, a substrate is not required. Therefore, it is possible to produce a substrate-less double-sided pressure-sensitive adhesive sheet.

[0095] When using the obtained pressure-sensitive adhesive sheet or substrate-less double-sided pressure-sensitive adhesive sheet, the release sheet is The adhesive is peeled off from the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer is attached to the adherend.

[0096] Examples of the substrate include polyethylene naphthalate and polyethylene terephthalate. , Polybutylene terephthalate, Polyethylene terephthalate / isophthalate copolymer Polyester resins such as polyethylene, polypropylene, polymethylpentene, etc. Olefin resins; polyvinyl fluoride, polyvinylidene fluoride, polyethylene fluoride, etc. Polyethylene fluoride resin; nylon 6, nylon 6,6 and other polyamides; polyvinyl chloride , polyvinyl chloride / vinyl acetate copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl vinyl polymers such as vinyl alcohol copolymers, polyvinyl alcohol, vinylon; Cellulose, cellophane and other cellulose-based resins; polymethyl methacrylate, polymethacrylate acrylic resins such as polyethyl acrylate, polyethyl acrylate, and polybutyl acrylate; Polyethylene; polycarbonate; polyarylate; polyimide; cycloolefin polymer, etc. Synthetic resin sheets; aluminum, copper, iron metal foil; fine paper, glassine paper, and other paper; glass fiber These substrates include woven fabrics and nonwoven fabrics made of fiber, natural fiber, synthetic fiber, etc. or as a multi-layer body in which two or more types are laminated.

[0097] 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. Furthermore, the substrate and the polyethylene terephthalate having a thin metal film layer are pressure-sensitively welded. It has excellent adhesive strength with adhesives and can keep the base material stable without corroding the metal thin film layer. This is preferable in that the effects of the pressure-sensitive adhesive according to the present invention can be significantly exhibited.

[0098] In the present invention, the ITO electrode film is formed on a polyethylene terephthalate (PET) substrate. The PET side of the film has a pressure-sensitive adhesive layer formed on it, and the adhesive layer The PET base material and polycarbonate (PC) film are laminated together, and then an acrylic film is applied. It is also preferable to use an optical laminate in which an ITO electrode film and a PET film are laminated (layer structure: ITO electrode film / PET film). Substrate / pressure-sensitive adhesive layer / PC film / acrylic film).

[0099] Examples of the release sheet include the various synthetic resin sheets, paper, cloth, and the like exemplified above as the substrate. Nonwoven fabrics or the like that have been subjected to release treatment can be used. Among them, the following are examples of release sheets: It is preferable to use a silicone-based release sheet.

[0100] 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.

[0101] The pressure-sensitive adhesive composition can be applied by, for example, a gravure roll coater or a river coater. Slow roll coater, kiss roll coater, dip roll coater, bar coater, A foam coater, a spray coater, a comma coater, or the like may be used.

[0102] 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.

[0103] The drying conditions after coating the pressure-sensitive adhesive composition are a drying temperature of 60 to 140°C. The drying temperature is preferably 80 to 120°C, and particularly preferably 80 to 120°C. The drying time is preferably 0.5 to 30 minutes. It is preferable, and particularly preferable that the time is 1 to 5 minutes.

[0104] The thickness of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet and the substrate-less double-sided pressure-sensitive adhesive sheet is Each of these is preferably 2 to 500 μm, particularly preferably 5 to 400 μm, and further preferably If the thickness of the pressure-sensitive adhesive layer is too thin, the adhesive strength decreases. If the coating is too thick, it will be difficult to apply evenly and air bubbles will appear in the coating. When considering shock absorption, it is recommended to use a thickness of 50 μm or more. It is preferable to set the following.

[0105] The thickness of the pressure-sensitive adhesive layer was measured using a Digimatic Indicator (Mitutoyo Corporation, ID- C112B) was used to measure the thickness of the entire adhesive sheet, and the thickness of the components other than the pressure-sensitive adhesive layer was measured. The thickness measurement value is calculated by subtracting the thickness measurement value of the first layer from the thickness measurement value of the second layer.

[0106] The gel fraction of the pressure-sensitive adhesive layer is 10% by weight or more from the viewpoint of durability and adhesive strength. It is particularly preferable that the content is 15 to 95% by weight, and further preferably 20 to 90% by weight. %, more preferably 25 to 80% by weight, and particularly preferably 30 to 70% by weight. If the gel content is too low, the cohesive strength will decrease, which will tend to reduce durability. If the ratio is too high, there is a concern that the adhesive strength will decrease due to an increase in cohesive strength.

[0107] 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 the base polymer sheet (e.g., PET film, etc.). The pressure-sensitive adhesive sheet (without separator) is then passed through a 200 mesh S The sample was wrapped in a US-made wire mesh and immersed in toluene at 23°C for 24 hours to determine the weight of the pressure-sensitive adhesive component before immersion. The weight percentage of the undissolved pressure-sensitive adhesive component remaining in the wire mesh after immersion relative to the amount of the adhesive was determined as the gel fraction. However, the weight of the substrate is to be subtracted.

[0108] The glass transition temperature (Tg) of the pressure-sensitive adhesive layer is preferably −40 to 40°C in terms of adhesive properties. °C, more preferably -30 to 30°C, and even more preferably -20 to 2 0°C, particularly preferably -15 to 15°C, and particularly preferably -10 to 10°C. If the glass transition temperature (Tg) is too high, flexibility will be lost, initial adhesion will decrease, and pressure equivalent to finger pressure will be insufficient. If the pressure is too low, the adhesive strength will be difficult to exert and workability will tend to decrease. However, the pressure-sensitive adhesive sheet tends to be easily deformed, which can impair the appearance. The glass transition temperature (Tg) of the pressure-sensitive adhesive layer is measured by the method described above. It can be measured in the same manner as in [I].

[0109] Furthermore, such a pressure-sensitive adhesive sheet may have a release sheet on the outside of the pressure-sensitive adhesive layer, if necessary. A pressure-sensitive adhesive layer may be protected by a protective film. In the case of pressure-sensitive adhesive sheets, a release treatment is applied to the surface of the substrate opposite the pressure-sensitive adhesive layer. The release-treated surface can also be used to protect the pressure-sensitive adhesive layer.

[0110] The pressure-sensitive adhesive of the present invention can be used to bond various members together. However, it is preferable to use it as a pressure-sensitive adhesive for optical components to bond optical components. A pressure-sensitive adhesive layer made of such a pressure-sensitive adhesive composition is laminated on an optical member. In this way, the above-mentioned optical member with a pressure-sensitive adhesive layer can be obtained.

[0111] 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 high The ITO electrode film is particularly preferred because it provides sufficient adhesive strength. The film is often formed as a thin film on a substrate such as glass or PET. It is particularly preferable to use a film in which the O electrode film is formed as a thin film on a PET substrate. 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.

[0112] The optical member with the pressure-sensitive adhesive layer further comprises a pressure-sensitive adhesive layer on the side opposite to the optical member side. It is preferable to provide a release sheet, and when put into practical use, the release sheet is peeled off, The pressure-sensitive adhesive layer is attached to the adherend. As the release sheet, a silicone-based release sheet is used. It is preferable to use [Example]

[0113] 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. It means weight basis (excluding "haze change"). In the following examples, the glass transition temperatures of the polyester resin [I] and the pressure-sensitive adhesive layer are The temperature was measured according to the method described above.

[0114] <Production of polyester resin> The "mol %" of the polycarboxylic acid (A) described in the following production examples refers to the amount of the polycarboxylic acid (A) The molar ratio is shown when the total amount of (A) is taken as 100 mol %. In addition, the "mol %" of polyol (B) described in the following production examples refers to the percentage of polyol (B) The molar ratios are shown when the total amount of the above is taken as 100 mol %.

[0115] [Production of polyester resin [I-1]] A reactor equipped with a heater, thermometer, stirrer, rectification column, nitrogen inlet tube and vacuum device was installed. As the carboxylic acid (A), 354.8 parts of isophthalic acid (IPA) and 354.8 parts of sebacic acid (S ebA) 185.1 parts, polyol (B) as 1,4-butanediol (1,4BG) 137.5 parts, 1,6-hexanediol (1,6HG) 30.6 parts, neopentyl glycol Coal (NPG) 285.9 parts, trimethylolpropane (TMP) 6.1 parts, catalyst 0.05 parts of zinc acetate was added, and the internal temperature was gradually increased to 250°C. Termination reaction was carried out. After that, the internal temperature was raised to 260°C, and 0.05 parts of tetrabutyl titanate was added as a catalyst. The pressure was reduced to 1.33 hPa, and the polymerization reaction was carried out for 3 hours to produce a polyester resin [I -1] was manufactured. The resulting polyester resin [I-1] had a glass transition temperature of 1°C and an acid value of 0.3 mgK. OH / g, the finished component ratio is isophthalic acid / sebacic acid as polycarboxylic acids (A) Acid = 70 mol% / 30 mol%, polyol (B) was 1,4-butanediol / 1,6 -Hexanediol / Neopentyl glycol / Trimethylolpropane=34 mol% / The ratio was 6 mol % / 58.5 mol % / 1.5 mol %.

[0116] [Production of polyester resin [I-2]] A reactor equipped with a heater, thermometer, stirrer, rectification column, nitrogen inlet tube and vacuum device was installed. As the carboxylic acid (A), 196.2 parts of isophthalic acid (IPA), 196.2 parts of sebacic acid (Seb A) 358.3 parts, polyol (B) 1,4-butanediol (1,4BG) 13 3.1 parts, 1,6-hexanediol (1,6HG) 29.7 parts, neopentyl glycol 276.8 parts of NPG, 5.9 parts of trimethylolpropane (TMP), acetic acid as a catalyst Add 0.05 parts of zinc oxide, gradually increase the internal temperature to 250°C, and add the ester over 4 hours. The polymerization reaction was carried out. After that, the internal temperature was raised to 260°C, and 0.05 parts of tetrabutyl titanate was added as a catalyst. The pressure was reduced to 1.33 hPa, and the polymerization reaction was carried out for 3 hours to produce a polyester resin [I -2] was manufactured. The resulting polyester resin [I-2] had a glass transition temperature of -33°C and an acid value of 0.3 m gKOH / g, the finished component ratio is isophthalic acid / sebacic acid as polycarboxylic acids (A). Synthetic acid = 40 mol% / 60 mol%, polyol (B) = 1,4-butanediol / 1 ,6-Hexanediol / Neopentyl glycol / Trimethylolpropane=34 moles % / 6 mol % / 58.5 mol % / 1.5 mol %.

[0117] [Production of Polyester Resin [I'-1]] A reactor equipped with a heater, thermometer, stirrer, rectification column, nitrogen inlet tube and vacuum device was installed. As the carboxylic acid (A), 96.1 parts of isophthalic acid (IPA) and 96.1 parts of sebacic acid (Se bA) 467.8 parts, 1,4-butanediol (1,4BG) as polyol (B) 30.3 parts, 1,6-hexanediol (1,6HG) 6 parts, neopentyl glycol ( 271 parts of NPG, 5.8 parts of trimethylolpropane (TMP), 0 parts of zinc acetate as catalyst The internal temperature was gradually increased to 250°C, and the esterification reaction was carried out over 4 hours. went. After that, the internal temperature was raised to 260°C, and 0.05 parts of tetrabutyl titanate was added as a catalyst. The pressure was reduced to 1.33 hPa, and the polymerization reaction was carried out for 3 hours to produce a polyester resin [I -3] was manufactured. The resulting polyester resin [I'-1] had a glass transition temperature of -48°C and an acid value of 0.2 mgKOH / g, the finished component ratio is isophthalic acid / selenite as polycarboxylic acids (A). Basic acid = 20 mol% / 80 mol%, 1,4-butanediol / as polyol (B) 1,6-Hexanediol / Neopentyl Glycol / Trimethylolpropane (TMP )=34 mol % / 6 mol % / 58.5 mol % / 1.5 mol %.

[0118] Resin composition (structural units derived from components) and glass transition temperature of the obtained polyester resin The results of (Tg) are also shown in Table 1 below.

[0119] [Table 1]

[0120] <Polycarbodiimide compounds> The following polycarbodiimide compounds were prepared: [II-1]: Polyethylene glycol monomethyl ester with an isocyanate terminal and a molecular weight of 500 Aromatic polycarbodiimide compounds substituted with ether-derived substituents (Nisshinbo Chemical (Manufactured by Carbodilite Co., Ltd., "Carbodilite V-04PF") [II'-1]: Aromatic polyisocyanates with terminally substituted substituents derived from aromatic monoisocyanates Carbodiimide compound (Nisshinbo Chemical Co., Ltd., "Carbodilite V-09GB")

[0121] <Crosslinking agent> The following crosslinking agents were prepared: [III-1]: Trimethylolpropane / tolylene diisocyanate adduct (Tosoh Corporation) (Manufacturer: Coronate L55E)

[0122] <Urethanization catalyst> The following urethanization catalysts were prepared: [IV-1]: Zirconium-based compound (macro) diluted with acetylacetone to a solid concentration of 1% Tsumoto Fine Chemical Co., Ltd., "Orgatics ZC-150")

[0123] <Production of Resin Composition> The polyester resins [I-1], [I-2], and [I'-1] obtained above and the above Using each of the components above, a resin composition (pressure-sensitive adhesive composition) was produced as follows.

[0124] Example 1 The polyester resin [I-1] obtained above was diluted with toluene to a solids concentration of 50%. To this polyester resin [I-1] solution (100 parts as solid content), 1.5 parts (solid content) of diimide compound [II-1] and 2 parts (solid content) of crosslinking agent [III-1] 0.02 parts (solid content) of urethane catalyst [IV-1], and stirring and mixing Thus, a resin composition (pressure-sensitive adhesive composition) was obtained.

[0125] Example 2 In Example 1, the polyester resin [I-1] was replaced with the polyester resin [I-2]. A resin composition (pressure-sensitive adhesive composition) was obtained in the same manner except for the above change.

[0126] (Comparative Example 1) The same procedure as in Example 1 was carried out except that the polycarbodiimide compound [II-1] was not added. In this manner, a resin composition (pressure-sensitive adhesive composition) was obtained.

[0127] (Comparative Example 2) In Example 1, the polycarbodiimide compound [II-1] was converted into a polycarbodiimide compound. A resin composition (pressure-sensitive adhesive composition) was obtained in the same manner as above, except that the compound [II'-1] was used instead.

[0128] (Comparative Example 3) In Example 1, the polyester resin [I-1] was replaced with the polyester resin [I'-1]. A resin composition (pressure-sensitive adhesive composition) was obtained in the same manner except for changing the above.

[0129] The resulting resin composition (pressure-sensitive adhesive composition) was evaluated as follows. are shown in Table 2 below.

[0130] <Production of substrate-less double-sided pressure-sensitive adhesive sheet> The pressure-sensitive adhesive compositions obtained in the examples and comparative examples were applied to a 100 μm-thick PET release sheet. The applicator was used on a sheet (Mitsui Chemicals Tocello, SP-PET-03-BU) (X). The adhesive was applied to the pressure-sensitive adhesive layer with a release sheet at 100°C for 4 minutes. A pressure-bonded sheet was obtained. Next, the surface of the pressure-sensitive adhesive layer of the obtained pressure-sensitive adhesive sheet with a release sheet is (X) is a 38 μm thick PET release sheet (Mitsui Chemicals Tocello, S Cover with P-PET-01-BU)(Y) and cure at 40°C for 4 days. A pressure-sensitive adhesive sheet was obtained. The glass transition temperature (Tg) of the pressure-sensitive adhesive layer in the obtained substrate-less double-sided pressure-sensitive adhesive sheet The results are shown in Table 2.

[0131] <Pressure-sensitive adhesive sheet evaluation> [Room temperature adhesion: 180 degree peel strength (N / 25mm)] The release sheet (Y) on one side of the substrateless double-sided pressure-sensitive adhesive sheet obtained above was peeled off. The pressure-sensitive adhesive layer was transferred onto a PET film (100 μm) to prepare a pressure-sensitive adhesive sheet for evaluation. The release sheet (X) on the other side of the obtained pressure-sensitive adhesive sheet for evaluation was peeled off. The exposed pressure-sensitive adhesive layer was then attached to a polycarbonate plate (Mitsubishi Chemical Corporation, Stella). After that, autoclave treatment (50°C, 0.5 MPa, 20 minutes) was performed to compress the PET film. A test specimen having a structure of rubber / pressure-sensitive adhesive layer / polycarbonate plate was prepared. The above test pieces were subjected to a tensile test using a Shimadzu Autograph AG-X 50N. Using the above, under the conditions of 23℃×50%RH, peeling speed 300mm / min, 180 degree peeling The strength was measured.

[0132] [High temperature adhesion: 180 degree peel strength (N / 25mm)] The release sheet (Y) on one side of the substrateless double-sided pressure-sensitive adhesive sheet obtained above was peeled off. The pressure-sensitive adhesive layer was transferred onto a PET film (100 μm) to prepare a pressure-sensitive adhesive sheet for evaluation. The release sheet (X) on the other side of the obtained pressure-sensitive adhesive sheet for evaluation was peeled off. The exposed pressure-sensitive adhesive layer was then attached to a polycarbonate plate (Mitsubishi Chemical Corporation, Stella). After that, autoclave treatment (50°C, 0.5 MPa, 20 minutes) was performed to compress the PET film. A test specimen having a structure of rubber / pressure-sensitive adhesive layer / polycarbonate 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 85°C, peel speed 300mm / min, 180° peel strength The degree was measured.

[0133] [Haze change] A release sheet on one side of the pressure-sensitive adhesive layer of the substrate-less double-sided pressure-sensitive adhesive sheet obtained above is (Y) was peeled off, and the pressure-sensitive adhesive layer was transferred to a PET film (100 μm) for evaluation. An adhesive sheet was prepared. The release sheet on the other side of the obtained pressure-sensitive adhesive sheet for evaluation was (X) was peeled off, and the exposed pressure-sensitive adhesive layer was placed on an alkali-free glass plate (Corning, E After laminating to the adhesive, autoclave treatment (50°C, 0.5 MPa, 20 minutes) was performed to reduce pressure. A test piece with a PET film / pressure-sensitive adhesive layer / non-alkali glass plate structure was prepared. did. The above test pieces were subjected to a damp heat test (85°C, 85% RH, 100 hours). The haze was measured 3 hours after the test and after removal from the test piece. The change was calculated and evaluated according to the following criteria. Oh, this unit complies with JIS K7361-1. (Evaluation criteria) Haze change (%) = Haze value after moist heat test (%) - Haze value before moist heat test (%) ◎ (Very good) Haze change less than 5%. ○ (Good): Haze change is 5% or more but less than 10%. △ (Average): Haze change of 10% or more but less than 15%. × (bad): Haze change of 15% or more.

[0134] [Table 2]

[0135] From the results in Table 2 above, it can be seen that the pressure-sensitive adhesive compositions of Examples 1 and 2 have excellent adhesive properties at high temperatures, and It can be seen that the change in haze under high temperature and high humidity conditions is very small. The pressure-sensitive adhesive compositions of No. 1 and No. 2 have excellent adhesive properties at high temperatures, but the haze change is extremely large. Furthermore, the pressure-sensitive adhesive composition of Comparative Example 3 was poor in performance as a pressure-sensitive adhesive. The adhesiveness was poor. [Industrial Applicability]

[0136] The polyester resin composition of the present invention has excellent adhesive strength under high temperature conditions. Even under humid conditions, the change in haze is small and it has excellent resistance to humidity and heat. compositions, particularly pressure-sensitive adhesive compositions and heat-sensitive adhesive compositions, particularly pressure-sensitive adhesive compositions and can be suitably used for bonding various members. The pressure-sensitive adhesive sheet using the adhesive agent is suitable for use in optical films and substrates that constitute displays. In the case of members, the film can be suitably used for bonding optical members.

Claims

1. A polyester resin composition comprising a polyester resin [I] having a glass transition temperature of −40 to 30° C. and a polycarbodiimide compound [II] in which at least one terminal isocyanate group in one molecule is substituted with a substituent derived from a hydrophilic organic compound (α), The polyester resin [I] has a structural unit derived from a polycarboxylic acid (A) and a structural unit derived from a polyol (B), The polyol (B) has, as structural units derived from a linear acyclic aliphatic diol (B-1) and a structural unit derived from a diol (B-2) having a hydrocarbon group in a side chain, The polyester-based resin composition is characterized in that the hydrophilic organic compound (α) is at least one selected from the group consisting of an oxyalkylene structure-containing compound, a hydroxypolyester structure-containing compound, a hydroxyalkylsulfonic acid structure-containing compound, a dialkylaminoalcohol structure-containing compound, a hydroxycarboxylic acid alkyl ester structure-containing compound, and a dialkylaminoalkylamine structure-containing compound.

2. the structural units derived from the linear acyclic aliphatic diol (B-1) account for 10 to 80 mol % of the structural units derived from the polyol (B); 2. The polyester resin composition according to claim 1, wherein the structural units derived from the diol (B-2) having a hydrocarbon group in a side chain account for 15 to 85 mol % of the structural units derived from the polyol (B).

3. 3. The polyester resin composition according to claim 1, wherein the polycarbodiimide compound [II] is an aromatic polycarbodiimide compound.

4. 4. The polyester resin composition according to claim 1, wherein the degree of polymerization of the polycarbodiimide compound [II] is 2 to 200.

5. The polyester resin composition according to any one of claims 1 to 4, characterized in that the hydrophilic organic compound (α) is an oxyalkylene structure-containing compound end-blocked with an alkoxy group or a phenoxy group.

6. 6. The polyester resin composition according to claim 1, wherein the hydrophilic organic compound (α) has a weight average molecular weight of 200 or more.

7. The polyester resin composition according to any one of claims 1 to 6, further comprising a crosslinking agent [III].

8. An adhesive composition comprising the polyester resin composition according to any one of claims 1 to 7.

9. A pressure-sensitive adhesive composition comprising the polyester resin composition according to any one of claims 1 to 7.

10. A pressure-sensitive adhesive obtained by crosslinking the pressure-sensitive adhesive composition according to claim 9.

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

12. 12. The pressure-sensitive adhesive sheet according to claim 11, which is used for bonding optical members.

13. 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 10.

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