JP2019206690A - Polyester adhesive composition, adhesive, adhesive sheet and optical member with adhesive layer - Google Patents

Abstract

To provide a polyester adhesive composition that has a small change of haze even under high-temperature and high-humidity conditions and also has excellent durability, an adhesive, an adhesive sheet and an optical member with an adhesive layer.SOLUTION: A polyester adhesive composition contains polyester resin [I] and hygroscopic filler [II].SELECTED DRAWING: None

Description

  The present invention relates to a polyester-based pressure-sensitive adhesive composition, a pressure-sensitive adhesive, a pressure-sensitive adhesive sheet, and an optical member with a pressure-sensitive adhesive layer, and more specifically, a polyester-based pressure-sensitive adhesive having a small change in haze even under high temperature and high humidity conditions and excellent durability. The present invention relates to a composition, an adhesive, an adhesive sheet, and an optical member with an adhesive layer.

  Conventionally, it has been known that polyesters having excellent chemical resistance and mechanical strength can be obtained by combining a polyvalent carboxylic acid component and a polyol component, and are useful in the field of pressure-sensitive adhesives. As a polyester-type adhesive, the adhesive of patent document 1 is mentioned, for example. In Patent Document 1, a carboxylic acid component containing 10 mol% or more and less than 50 mol% of an aromatic carboxylic acid and a polyhydric alcohol component containing 5 mol% or more of a glycol having a hydrocarbon group in the side chain are subjected to polycondensation. And a pressure-sensitive adhesive obtained by using a polyester resin having a number average molecular weight of 5000 or more is described, and is said to have excellent adhesiveness, heat resistance, and mechanical strength.

JP 2007-45914 A

  However, in recent years, pressure-sensitive adhesives are increasingly used in the production of display devices such as liquid crystal displays (LCDs) and input devices such as touch panels used in combination with the above display devices. There is a demand for pressure-sensitive adhesives that have a small change in haze under wet conditions and are excellent in durability. Although the polyester-based pressure-sensitive adhesive of Patent Document 1 is excellent in adhesiveness, heat resistance, and mechanical strength, the performance under high-temperature and high-humidity conditions is not fully satisfactory, and further improvement is required.

  Therefore, in the present invention, under such a background, a polyester-based pressure-sensitive adhesive composition, a pressure-sensitive adhesive, a pressure-sensitive adhesive sheet, and an optical member with a pressure-sensitive adhesive layer having a small change in haze even under high temperature and high humidity conditions and excellent durability. The purpose is to provide.

  However, as a result of intensive research in view of such circumstances, the present inventor has made the polyester resin [I] contain the hygroscopic filler [II], thereby reducing the change in haze even under high-temperature and high-humidity conditions. The present inventors have found that a polyester-based pressure-sensitive adhesive composition having excellent properties can be obtained, thereby completing the present invention.

  That is, the first gist of the present invention is a polyester-based pressure-sensitive adhesive composition containing a polyester-based resin [I] and a hygroscopic filler [II].

  Moreover, this invention makes the adhesive sheet formed by bridge | crosslinking the said polyester-type adhesive composition a 2nd summary, the adhesive sheet which has an adhesive layer containing the said adhesive 3rd summary, and an adhesive layer An optical member with a pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer contains the pressure-sensitive adhesive.

As described above, in order to improve the wet heat durability of the polyester-based pressure-sensitive adhesive composition, it is known that the polyester-based pressure-sensitive adhesive composition contains a monomer having a side chain structure to increase cohesion and hydrophobicity. . However, the present invention is not characterized by such a method, but is characterized by containing polyester resin [I] and hygroscopic filler [II].
That is, the hygroscopic filler [II] has poor compatibility with the polyester resin [I] and has been considered to cause turbidity when used with the polyester resin [I]. It is. However, surprisingly, even when the polyester-based resin [I] and the hygroscopic filler [II] are used in combination, the turbidity does not occur, and the hydrophilicity can be increased. They found that the haze change was small and the durability became excellent.

  Since the polyester-based pressure-sensitive adhesive composition of the present invention contains the polyester-based resin [I] and the hygroscopic filler [II], the haze change is small even under high-temperature and high-humidity conditions and the durability is excellent. Therefore, it is suitable for use as an adhesive for optical members.

Hereinafter, although it demonstrates in detail about the structure of this invention, these show an example of a desirable embodiment.
In the present invention, the term “carboxylic acids” includes carboxylic acid derivatives such as carboxylic acid salts, carboxylic acid anhydrides, carboxylic acid halides, and carboxylic acid esters in addition to carboxylic acids.

The polyester-based pressure-sensitive adhesive composition of the present invention (hereinafter sometimes referred to as “pressure-sensitive adhesive composition”) is characterized by containing a polyester-based resin [I] and a hygroscopic filler [II]. The pressure-sensitive adhesive composition of the present invention comprises the polyester resin [I] and the hygroscopic filler [II] as essential components, a hydrolysis inhibitor [III], a crosslinking agent [IV], and a urethanization catalyst [V]. It is preferable to contain at least one selected from the group consisting of the above, and it is more preferred to contain any of the hydrolysis inhibitor [III], the crosslinking agent [IV] and the urethanization catalyst [V].
Each component constituting the pressure-sensitive adhesive composition of the present invention will be sequentially described below.

<Polyester resin [I]>
The polyester resin [I] is usually obtained by copolymerizing (condensation polymerization) a copolymer component containing polyvalent carboxylic acids (A) and polyol (B) as constituent raw materials, and the polyester resin [I] ] Has a structural unit derived from polyvalent carboxylic acids (A) and a structural unit derived from polyol (B) as its resin composition.

[Polyvalent carboxylic acids (A)]
Examples of the polyvalent carboxylic acids (A) used as a constituent material of the polyester resin [I] include divalent carboxylic acids and trivalent or higher polyvalent carboxylic acids, and the polyester resin [I] can be stably used. From the viewpoint of being obtained, divalent carboxylic acids are preferably used. These polyvalent carboxylic acids (A) can be used alone or in combination of two or more.

Examples of the divalent carboxylic acids include malonic acids, dimethyl malonic acids, succinic acids, glutaric acids, adipic acids, trimethyladipic acids, pimelic acids, 2,2-dimethylglutaric acids, azelaic acids, sebacic acids, fumaric acids, Aliphatic dicarboxylic acids such as maleic acid, itaconic acid, thiodipropionic acid, diglycolic acid, 1,9-nonanedicarboxylic acid;
Phthalic acids, terephthalic acids, isophthalic acids, benzylmalonic acids, diphenic acids, 4,4′-oxydibenzoic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, 2,7-naphthalenedicarboxylic acids, etc. Aromatic dicarboxylic acids such as naphthalene dicarboxylic acids;
Alicyclics such as 1,3-cyclopentanedicarboxylic acids, 1,2-cyclohexanedicarboxylic acids, 1,3-cyclopentanedicarboxylic acids, 1,4-cyclohexanedicarboxylic acids, 2,5-norbornanedicarboxylic acids, adamantanedicarboxylic acids Dicarboxylic acids;
Etc.
Examples of the trivalent or higher carboxylic acids include trimellitic acids, pyromellitic acids, adamantanetricarboxylic acids, trimesic acids, and the like.

  Among the polyvalent carboxylic acids (A), from the viewpoint of lowering the crystallinity of the polyester resin [I], it is preferable to include aromatic polycarboxylic acids, and to include aromatic dicarboxylic acids (a1). Is particularly preferred. Of the aromatic polycarboxylic acids, it is preferable to use asymmetric aromatic polycarboxylic acids from the viewpoint of lowering crystallinity, and it is particularly preferable to use asymmetric aromatic dicarboxylic acids (a1-1). preferable. Examples of such asymmetric aromatic dicarboxylic acids (a1-1) include isophthalic acid, terephthalic acid, benzylmalonic acid, diphenic acid, 4,4′-oxydibenzoic acid, naphthalenedicarboxylic acid, and the like. Especially, as said asymmetrical aromatic dicarboxylic acid (a1-1), isophthalic acid is preferable.

  In the present invention, the polyvalent carboxylic acids (A) are aliphatic dicarboxylic acids (a2) having 4 or more carbon atoms (including carboxy group carbon) from the viewpoint of improving the initial adhesive strength (tack) of the pressure-sensitive adhesive. In particular, it is more preferable to contain an aliphatic dicarboxylic acid having 9 to 12 carbon atoms (including carbon of a carboxy group) such as azelaic acid and sebacic acid.

  Furthermore, in the present invention, a small amount of a sulfonate group-containing dicarboxylic acid (a3) may be used as the polyvalent carboxylic acid (A). The sulfonate group-containing dicarboxylic acid (a3) is not particularly limited as long as it is a monomer component having both a dicarboxy group and a sulfonate group in the molecule, and examples thereof include sodium sulfonate and potassium sulfonate. Phthalic acid, isophthalic acid, terephthalic acid and mono- or diesters thereof containing an alkali metal sulfonate are preferably used. The sulfonate group-containing dicarboxylic acids (a3) can be used alone or in combination of two or more.

  Specific examples of the sulfonate group-containing dicarboxylic acids (a3) include, for example, dimethyl sodium 4-sulfoisophthalate, sodium 5-sulfoisophthalate, dimethyl sodium 5-sulfoisophthalate, dimethyl potassium 4-sulfoisophthalate, Examples include dimethyl potassium 5-sulfoisophthalate, sodium 2-sulfoterephthalate, potassium 2-sulfoterephthalate, dimethyl sodium 2-sulfoterephthalate, and dimethyl potassium 2-sulfoterephthalate. Among these, dimethyl sodium 5-sulfoisophthalate is preferably used.

  In the present invention, trivalent or higher polyvalent carboxylic acids (a4) can be used for the purpose of increasing branch points in the polyester-based resin [I]. It is preferable to use trimellitic acids in that they are not easily generated.

[Polyol (B)]
In the present invention, examples of the polyol (B) used together with the polyvalent carboxylic acid (A) as a constituent raw material of the polyester resin [I] include dihydric alcohols and trihydric or higher polyols.

Examples of the dihydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, -Methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl -1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2,2 Aliphatic diols such as 1,4-trimethyl-1,6-hexanediol;
1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, spiroglycol, tricyclodecane dimethanol, adamantanediol, 2,2,4,4-tetramethyl-1,3 -Alicyclic diols such as cyclobutanediol;
4,4′-thiodiphenol, 4,4′-methylenediphenol, 4,4′-dihydroxybiphenyl, o-, m- and p-dihydroxybenzene, 2,5-naphthalenediol, p-xylenediol and the like And aromatic diols such as ethylene oxide adducts and propylene oxide adducts.
Furthermore, fatty acid esters derived from castor oil, dimer diols derived from oleic acid, erucic acid and the like, glycerol monostearate and the like can be mentioned.
Examples of the trivalent or higher polyol include pentaerythritol, dipentaerythritol, tripentaerythritol, glycerin, trimethylolpropane, trimethylolethane, 1,2,4-butanetriol, 1,2,5-pentane. Examples include triol, 1,2,6-hexanetriol, 1,3,6-hexanetriol, adamantanetriol and the like.
These polyols (B) can be used alone or in combination of two or more.

  Among the polyols (B), it is preferable to contain the diol compound (b1) having a hydrocarbon group in the side chain from the viewpoint of increasing the branch point and breaking the crystallinity. Examples of the diol compound (b1) having a hydrocarbon group in the side chain include dipropylene glycol, 2,4-dimethyl-2-ethylhexane-1,3-diol, and 2-methyl-1,3- Propanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2-methyl-2-ethyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol 2-ethyl-2-isobutyl-1,3-propanediol, 1,3-butanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,6-hexanediol, etc. Aliphatic diols having a branched structure, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethano Le, spiro glycol, tricyclodecane, adamantane diol, 2,2,4,4 alicyclic diols such as tetramethyl-1,3-cyclobutanediol and the like.

  The diol compound (b1) having a hydrocarbon group in the side chain is preferably a diol compound having a hydrocarbon group having 1 to 6 carbon atoms from the viewpoint of preventing crystallization while maintaining mechanical strength and heat resistance. A diol compound having a hydrocarbon group having 1 to 4 carbon atoms is more preferred, and neopentyl glycol and 2-methyl-2-ethyl-1,3-propanediol are more preferred.

  In the present invention, the polyol (B) contains the aliphatic diol (b2) having a linear structure from the viewpoint of lowering the glass transition temperature (Tg) of the polyester resin [I] and improving the initial adhesive strength. More preferably, it is an aliphatic diol having a linear structure having 1 to 10 carbon atoms, and particularly preferably diethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol. It is. Among these, 1,4-butanediol and 1,6-hexanediol are particularly preferable in that the glass transition temperature (Tg) of the polyester resin [I] can be lowered and the tackiness becomes more excellent. .

  Furthermore, in the present invention, a trivalent or higher polyol (b3) is used as the polyol (B) from the viewpoint of forming a reaction point with the below-mentioned crosslinking agent [IV] in the polyester resin [I] and increasing the cohesive force Among them, trimethylolpropane, trimethylolethane, glycerin, pentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, and 1,2,6-hexanetriol are used. It is preferable. Among these, it is preferable to use trimethylolpropane because it is relatively difficult to generate a gel.

  As a blending ratio of the polyvalent carboxylic acids (A) and the polyol (B), the polyol (B) is preferably 1 to 2 equivalents, more preferably 1.1 per equivalent of the polyvalent carboxylic acids (A). -1.7 equivalents. If the blending ratio of the polyol (B) is too low, the acid value tends to be high and it is difficult to increase the molecular weight, and if it is too high, the yield tends to decrease.

(Production method)
The polyester-based resin [I] used in the present invention is produced by arbitrarily selecting the polyvalent carboxylic acid (A) and the polyol (B) and subjecting them to a polycondensation reaction by a known method in the presence of a catalyst. The

In the polycondensation reaction, an esterification reaction is first performed and then a polycondensation reaction is performed.
In the esterification reaction, a catalyst is used. Specifically, for example, titanium-based catalysts such as tetraisopropyl titanate and tetrabutyl titanate, antimony-based catalysts such as antimony trioxide, germanium-based catalysts such as germanium dioxide, etc. Examples thereof include catalysts and catalysts such as zinc acetate, manganese acetate, and dibutyltin oxide, and one or more of these are used. Among these, it is preferable to use antimony trioxide, tetrabutyl titanate, germanium dioxide, and zinc acetate from the balance between the high catalytic activity and the hue of the obtained reaction product.

  The amount of the catalyst is preferably 1 to 10,000 ppm, more preferably 10 to 5,000 ppm, and still more preferably 10 to 3,000 ppm with respect to all copolymer components. When the blending amount of the catalyst is too small, the polymerization reaction tends not to proceed sufficiently, and when it is too large, there is no advantage such as shortening the reaction time and a side reaction tends to occur.

  The reaction temperature in the esterification reaction is preferably 160 to 280 ° C, particularly preferably 180 to 270 ° C, and further preferably 200 to 260 ° C. If the reaction temperature is too low, the reaction tends not to proceed sufficiently, and if it is too high, side reactions such as decomposition tend to occur. Moreover, the pressure at the time of reaction is usually a normal pressure.

  The reaction time in the esterification reaction is preferably 1 to 48 hours, more preferably 1.5 to 24 hours, and further preferably 2 to 12 hours.

  As the reaction conditions for the polycondensation reaction performed after the esterification reaction, the same amount of the same catalyst as that used in the esterification reaction is further blended, and the reaction temperature is preferably 220 to 280 ° C, particularly preferably. It is preferable that the reaction system is gradually depressurized at 230 to 270 ° C. and finally reacted at 5 hPa or less. If the reaction temperature is too low, the reaction tends not to proceed sufficiently, and if it is too high, side reactions such as decomposition tend to occur.

  The reaction time in the polycondensation reaction is preferably 1 to 48 hours, more preferably 1.5 to 24 hours, and further preferably 2 to 12 hours.

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

(composition)
The polyester resin [I] has a structural unit derived from the polyvalent carboxylic acid (A) and a structural unit derived from the polyol (B), and the structural unit derived from the aromatic polyvalent carboxylic acid is a polyvalent carboxylic acid ( When included as a structural unit derived from A), the structural unit derived from aromatic polyvalent carboxylic acid is preferably 1 to 100 mol%, particularly preferably, in the structural unit derived from polyvalent carboxylic acid (A). Is 20 to 95 mol%, more preferably 40 to 90 mol%, particularly preferably 50 to 85 mol%, more preferably 60 to 80 mol%. If the content is too small, the cohesive force of the pressure-sensitive adhesive tends to be reduced, and it tends to be lifted or peeled off. If the content is too large, the flexibility of the polyester resin [I] is lost, and the pressure-sensitive adhesive There is a tendency for the initial adhesive strength (tack) of the to decrease.

  The polyvalent carboxylic acid (A) preferably contains an aromatic dicarboxylic acid (a1). The content ratio is preferably 1 to 100 mol%, more preferably 20 to 95 mol%, still more preferably 40 to 90 mol%, particularly preferably in the structural unit derived from the polyvalent carboxylic acid (A). Is from 50 to 85 mol%, more preferably from 60 to 80 mol%. If the content is too small, the cohesive force of the pressure-sensitive adhesive tends to decrease, and there is a tendency to float or peel off. If it is too large, the flexibility of the polyester-based resin [I] is lost, and the initial pressure-sensitive adhesive properties are reduced. Tend to.

  When the aromatic dicarboxylic acid (a1) contains an asymmetric aromatic dicarboxylic acid (a1-1), the content is preferably 62 mol% or more with respect to the entire aromatic dicarboxylic acid (a1). More preferably, it is 65 mol% or more, further preferably 70 mol% or more, and particularly preferably 80 mol% or more. When there is too little content of asymmetric aromatic dicarboxylic acid (a1-1), there exists a tendency for the crystallinity of polyester-type resin [I] to become high and the solubility with respect to a solvent to fall.

  When the structural unit derived from aliphatic dicarboxylic acids (a2) having 4 or more carbon atoms (including carbon of carboxy group) is included as a structural unit derived from polyvalent carboxylic acids (A), The structural unit derived from 4 or more aliphatic dicarboxylic acids (a2) (including carbon) is preferably less than 99 mol% in the structural unit derived from the polyvalent carboxylic acids (A), more preferably 5 to 80 mol. %, More preferably 10 to 60 mol%, particularly preferably 15 to 50 mol%, particularly preferably 20 to 40 mol%. When the content of the aliphatic dicarboxylic acid (a2) is too large, the adhesive component tends to decrease, and thus the adhesive force to a polar adherend tends to decrease. In addition, when there is too little content of the said aliphatic dicarboxylic acid (a2), there exists a tendency for the glass transition temperature (Tg) of polyester-type resin [I] to become high, and sufficient adhesive force not to be obtained.

  When the structural unit derived from the sulfonate group-containing dicarboxylic acid (a3) is included as a structural unit derived from the polyvalent carboxylic acid (A), 0.001 to 0.001 in the structural unit derived from the polyvalent carboxylic acid (A) The amount is preferably 10 mol%, particularly preferably 0.01 to 5 mol%, more preferably 0.03 to 3 mol%, and particularly preferably 0.05 to 2 mol%. If the amount of the sulfonate group-containing dicarboxylic acid (a3) is too small, the haze after the moist heat test tends to increase (transparency decreases), and if too large, the durability tends to decrease.

  When the structural unit derived from the trivalent or higher polyvalent carboxylic acid (a4) is included as a structural unit derived from the polyvalent carboxylic acid (A), the structural unit derived from the trivalent or higher polyvalent carboxylic acid (a4) However, it is preferable that it is 10 mol% or less in a structural unit derived from polyhydric carboxylic acid (A), More preferably, it is 0.1-5 mol%. If the content of the trivalent or higher polyvalent carboxylic acid (a4) is too large, gelation tends to occur during the production of the polyester resin [I].

  When the structural unit derived from the diol compound (b1) having a hydrocarbon group in the side chain is included as the structural unit derived from the polyol (B), the structural unit is derived from the diol compound (b1) having a hydrocarbon group in the side chain. Is preferably 5 mol% or more, more preferably 10 to 90 mol%, and still more preferably 15 to 80 mol% in the structural unit derived from the polyol (B). If the content of the diol compound (b1) having a hydrocarbon group in the side chain is too small, the polyester resin [I] tends to crystallize and the initial adhesive strength of the pressure-sensitive adhesive tends to be reduced. When there are too many diol compounds (b1) which have a hydrogen group, there exists a tendency for the reactivity at the time of manufacture of polyester-type resin [I] to fall.

  When the structural unit derived from the aliphatic diol (b2) having the linear structure is included as a structural unit derived from the polyol (B), the structural unit derived from the aliphatic diol (b2) having the linear structure is polyol. It is preferable that it is 5-95 mol% in the structural unit derived from (B), More preferably, it is 10-90 mol%, More preferably, it is 20-80 mol%. When the amount of the aliphatic diol (b2) having the linear structure is too large, the polyester resin [I] tends to crystallize and the initial tackiness of the pressure-sensitive adhesive tends to be lowered. When there is too little, there exists a tendency for the reactivity at the time of manufacture of polyester-type resin [I] to fall.

  When the structural unit derived from the trivalent or higher polyol (b3) is included as a structural unit derived from the polyol (B), the structural unit derived from the trivalent or higher polyol (b3) is derived from the polyol (B). It is preferable that it is 10 mol% or less in a structural unit of, More preferably, it is 0.1-5 mol%. When there are too many trivalent or more polyols (b3), polyester-type resin [I] will gelatinize at the time of manufacture, and there exists a tendency for manufacture to become difficult.

  Here, the structural unit ratio (composition ratio) derived from each component of the polyester resin [I] can be determined by, for example, nuclear magnetic resonance (NMR).

(Physical properties)
In the present invention, the polyester resin [I] preferably has a glass transition temperature (Tg) of -20 to 30 ° C, more preferably -15 to 25 ° C, still more preferably -10 to 20 ° C, and particularly preferably. Is −5 to 10 ° C. That is, it is preferable that the glass transition temperature of the polyester-based resin [I] is higher than that of a general polyester-based resin used in the pressure-sensitive adhesive composition, since the blister resistance is improved. If the glass transition temperature is too high, the flexibility of the polyester-based resin [I] is lost, the initial adhesiveness of the adhesive (adhesiveness at the time of bonding to the adherend) is lowered, and the pressure is about the finger pressure. However, since it becomes difficult to exhibit sufficient adhesive force, workability | operativity falls. On the other hand, when the glass transition temperature is too low, the cohesive force of the pressure-sensitive adhesive is lowered, and the floating is likely to occur.

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

  In the present invention, it is preferable from the viewpoint of storage stability that the polyester resin [I] is not crystallized. However, even in the case of crystallization, it is preferable that the crystallization energy of the polyester resin [I] is as low as possible. 35 J / g or less, preferably 20 J / g or less, particularly preferably 10 J / g or less, particularly preferably 5 J / g or less. The lower limit is usually 0 J / g.

  In the present invention, the acid value of the polyether-based resin [I] is preferably 10 mgKOH / g or less, more preferably 5 mgKOH / g or less, still more preferably 1 mgKOH / g or less, particularly preferably 0.5 mgKOH / g or less. is there. If the acid value is too high, the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition of the present invention tends to be hydrolyzed and the durability tends to decrease. Moreover, when it becomes the structure used as the metal oxide thin film layer on one surface of an adhesive layer, there exists a tendency for corrosion to occur and the electroconductivity of a metal oxide film to fall.

Here, the acid value of the polyester resin [I] is based on JIS K 0070 by dissolving 10 g of the polyester resin [I] in a mixed solvent having a volume ratio of toluene and methanol of 7/3 (toluene / methanol). It is obtained by neutralization titration.
In addition, in this invention, the acid value of polyester-type resin [I] means content of the carboxy group in resin.

  Moreover, it is preferable that the number average molecular weights of the said polyester-type resin [I] are 5,000 or more, More preferably, it is 8,000-150,000, More preferably, it is 10,000-80,000. That is, if the number average molecular weight is too low, sufficient cohesive force as an adhesive cannot be obtained, and heat resistance and mechanical strength tend to decrease. If the number average molecular weight is too high, flexibility is lost. The initial tackiness of the pressure-sensitive adhesive tends to decrease.

In addition, the number average molecular weight in this specification is a number average molecular weight in terms of standard polystyrene molecular weight, and column: TSKgel SuperMultipore HZ-M (excluded) on a high performance liquid chromatograph (manufactured by Tosoh Corporation, “HLC-8320GPC”). The molecular weight is 2 × 10 ⁶ , the number of theoretical plates: 16,000 plates / line, the filler material: styrene-divinylbenzene copolymer, and the particle size of filler particle: 4 μm). is there.

<Hygroscopic filler [II]>
The pressure-sensitive adhesive composition of the present invention contains a hygroscopic filler [II] together with the polyester resin [I]. By including the hygroscopic filler [II], the hydrophilicity of the pressure-sensitive adhesive can be increased, preventing water from aggregating in the pressure-sensitive adhesive layer when a wet heat environment load is applied, and the change in haze before and after wet heat durability. Small and excellent in optical characteristics.
Such a hygroscopic filler [II] is an inorganic filler having an ability to absorb moisture, and examples thereof include hygroscopic metal oxides that chemically react with moisture that has been absorbed to become hydroxides. Examples of such a material include at least one selected from the group consisting of calcium oxide, magnesium oxide, strontium oxide, aluminum oxide, and barium oxide, or a mixture or solid solution of two or more. As said 2 or more types of mixture or solid solution, a baking dolomite, a baking hydrotalcite, etc. are mentioned, for example.

Of these, calcium oxide, magnesium oxide, and calcined hydrotalcite are preferable as the hygroscopic filler [II] of the present invention because of its excellent hygroscopicity and supply stability and low cost, and more preferably calcined hydrotalcite. It is. Moreover, from the point that the haze change before and after the wet heat test is small, forced dehydration of a metal inorganic compound containing crystal water is preferable, and calcined hydrotalcite is more preferable. The above-mentioned forced dehydration of inorganic metal compound containing crystal water is a dehydrated product of metal inorganic compound containing crystal water by heating at high temperature (usually 180 ° C. or higher) for 30 minutes or more to reduce its water content. It is. The calcined hydrotalcite calcinates natural hydrotalcite (Mg ₆ Al ₂ (OH) ₁₆ CO ₃ .4H ₂ O) and synthetic hydrotalcite (hydrotalcite-like compound), and determines the amount of OH in the chemical structure. Reduced or eliminated. In the present invention, among the calcined hydrotalcites, a calcined product of a synthetic hydrotalcite represented by the following general formula (1) and a calcined product of a synthetic hydrotalcite represented by the following general formula (2): preferable.

The calcined hydrotalcite preferably has a BET specific surface area of 1 m ² / g or more, more preferably a BET specific surface area of 2 to 2 from the viewpoint of improving the transparency of the cured product of the polyester-based pressure-sensitive adhesive composition. was 300m ² / g, more preferably from BET specific surface area of 3~200m ² / g.

  In the present invention, a commercially available product may be used as the hygroscopic filler [II]. Examples of commercially available products include calcium oxide (manufactured by Sankyo Seimitsu Co., Ltd., Moistop series), magnesium oxide (manufactured by Kyowa Chemical Industry Co., Ltd., Kyowa Mag MF150, Kyowa Mag MF30), "manufactured by Tateho Chemical Industry Co., Ltd., PUREMAG FNM-G". ), Light calcined magnesium oxide (manufactured by Tateho Chemical Industry Co., Ltd., TATEHOMAG series), calcined dolomite (manufactured by Yoshizawa Lime Industry Co., Ltd., KT), calcined hydrotalcite (manufactured by Kyowa Chemical Industry Co., Ltd., DHT-4A, DHT-4A-2) , DHT-4C, KW-2000, KW-2100, KW-2200 ”,“ manufactured by Sakai Chemical Co., Ltd., STABIACE HT-1, STABIACE HT-7, STABIACE HT-9, STABIACE HT-P ”) and the like. .

  The hygroscopic filler [II] is preferably a surface treated with a surface treatment agent from the viewpoint of compatibility with the polyester resin [I]. As the surface treatment agent, for example, higher fatty acids, alkoxysilanes, silane coupling agents and the like can be used, and among these, higher fatty acids and alkoxysilanes are preferably used. The said surface treating agent can be used individually or in combination of 2 or more types.

  Examples of the higher fatty acid include higher fatty acids having 18 or more carbon atoms such as stearic acid, montanic acid, myristic acid, and palmitic acid. Among these, stearic acid is preferable. These may be used alone or in combination of two or more.

  Examples of the alkoxysilanes include methyltrimethoxysilane, ethyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, octadecyltrimethoxysilane, dimethyldimethoxysilane, octyltriethoxysilane, and n-octadecyldimethyl. (3- (trimethoxysilyl) propyl) ammonium chloride and the like. These may be used alone or in combination of two or more.

  Examples of the silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropyl (dimethoxy) methylsilane, and 2- (3,4-epoxycyclohexyl) ethyltri Epoxy silane coupling agents such as methoxysilane; mercapto silane couplings such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane and 11-mercaptoundecyltrimethoxysilane Agents: 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, N-phenyl-3-aminopropyltrime Amino silane cups such as xylsilane, N-methylaminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane and N- (2-aminoethyl) -3-aminopropyldimethoxymethylsilane Ringing agent; Ureido silane coupling agent such as 3-ureidopropyltriethoxysilane, vinyl silane coupling agent such as vinyltrimethoxysilane, vinyltriethoxysilane and vinylmethyldiethoxysilane; p-styryltrimethoxysilane Styryl-based silane coupling agents; acrylate-based silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane; 3-isocyanatopropyltrimethoxysilane Isocyanate-based silane coupling agents, sulfide-based silane coupling agents such as bis (triethoxysilylpropyl) disulfide, bis (triethoxysilylpropyl) tetrasulfide; phenyltrimethoxysilane, methacryloxypropyltrimethoxysilane, imidazolesilane, triazine A silane etc. can be mentioned. These may be used alone or in combination of two or more.

  The surface treatment of the hygroscopic filler [II] is performed, for example, by spraying the surface treatment agent while stirring the untreated hygroscopic filler with a mixer at normal temperature and further stirring for 5 to 60 minutes. It can be carried out. Examples of the mixer include blenders such as a V blender, a ribbon blender, and a bubble cone blender, mixers such as a Henschel mixer and a concrete mixer, a ball mill, and a cutter mill. Further, when the hygroscopic material (hygroscopic filler material) is pulverized by a ball mill or the like, the surface treatment can be performed by adding and mixing the surface treatment agent. Although the said surface treating agent changes also with the kind of hygroscopic filler, the kind of surface treating agent, etc., it is preferable to use 1-10 weight part with respect to 100 weight part of a hygroscopic filler.

  The content of the hygroscopic filler [II] is preferably 0.001 to 10 parts by weight, more preferably 0.005 to 5 parts by weight, further preferably 100 parts by weight of the polyester resin [I]. Is from 0.01 to 3 parts by weight, particularly preferably from 0.03 to 1 part by weight. If the content of the hygroscopic filler [II] is too large, it is difficult to be compatible with the polyester resin [I] and becomes cloudy and the optical properties are lowered, or the flexibility of the polyester resin [I] is impaired and the adhesive strength is lowered. Tend to. On the other hand, if the content of the hygroscopic filler [II] is too small, the hygroscopic performance tends to be lowered and the effect of reducing the haze change after the wet heat test tends not to be sufficiently obtained.

  The hygroscopic filler [II] usually has an average particle diameter of 1 to 5 μm, but considering use of the hygroscopic filler [II] in an adhesive composition for an optical member, it is preferably 0.01 to 1 μm, more preferably. The thickness is preferably 0.01 to 0.8 μm, particularly 0.01 to 0.5 μm. Further, the hygroscopic filler [II] preferably has a particle diameter of 5 μm or more in an amount of 1% by weight or less, more preferably 0.3% by weight or less of the entire hygroscopic filler [II]. The average particle diameter can be measured, for example, with a laser diffraction particle size distribution measuring apparatus.

  In the present invention, when the hygroscopic filler [II] is contained in the polyester resin [I], (1) the hygroscopic filler [II] is blended with the polyester resin [I], or (2) the above The hygroscopic filler [II] can be present in the reaction system together with each monomer during the production of the polyester resin [I] and can be uniformly dispersed in the polyester resin [I]. The method (2) is preferred in that the filler [II] can be dehydrated.

  In the present invention, when the hygroscopic filler [II] is contained in the polyester resin [I], the glass transition temperature (Tg) is −20 as the polyester resin [I] as described above. It is preferable to use a polyester resin [I] of ˜30 ° C. Furthermore, it is preferable to adjust so that the glass transition temperature (Tg) may become -20-30 degreeC as a mixture of polyester-type resin [I] and a hygroscopic filler [II].

  In the pressure-sensitive adhesive composition of the present invention, an optional component may be used together with the polyester resin [I] and the hygroscopic filler [II]. Examples of the optional component include a hydrolysis inhibitor [III], Examples thereof include a crosslinking agent [IV] and a urethanization catalyst [V]. The hydrolysis inhibitor [III] is contained for ensuring long-term durability, and the cross-linking agent [IV] is an adhesive that cross-links the polyester resin [I] and has excellent cohesive strength. As a result, the performance is improved. The urethanization catalyst [V] is used to adjust the curing rate. In addition to these components, as long as the effects of the present invention are not impaired, an antioxidant such as a catalyst inhibitor, a hindered phenol, a softener, an ultraviolet absorber, a stabilizer, an antistatic agent, and tackifying Additives such as additives, and other additives such as inorganic or organic fillers, powders such as metal powders and pigments, and particulates. These may be used alone or in combination of two or more.

<Hydrolysis inhibitor [III]>
As the hydrolysis inhibitor [III], conventionally known ones can be used, and examples thereof include compounds that react with and bind to the carboxylic acid end groups of the polyester resin [I]. Examples thereof include compounds containing a functional group such as a carbodiimide group, an epoxy group, and an oxazoline group. Among these, a carbodiimide group-containing compound is preferable in that it has a high effect of eliminating the catalytic activity of protons derived from carboxy group end groups.

  As the carbodiimide group-containing compound, a known carbodiimide having at least one carbodiimide group (—N═C═N—) in the molecule may be used, but it is more durable at higher temperatures and higher humidity. It is preferably a compound containing two or more carbodiimide groups in the molecule, that is, a polyvalent carbodiimide compound, particularly a compound containing three or more, more preferably five or more, particularly seven or more. Is preferred. In addition, when it contains 50 or more, the molecular structure becomes too large, so that the compatibility tends to decrease. It is also preferable to use a high molecular weight polycarbodiimide produced by decarboxylation condensation reaction of diisocyanate in the presence of a carbodiimidization catalyst.

  Examples of such a high molecular weight polycarbodiimide include those obtained by subjecting the following diisocyanates to a decarboxylation condensation reaction.

  Examples of the diisocyanate include 4,4′-diphenylmethane diisocyanate, 3,3′-dimethoxy-4,4′-diphenylmethane diisocyanate, 3,3′-dimethyl-4,4′-diphenylmethane diisocyanate, and 4,4′-. Diphenyl ether diisocyanate, 3,3′-dimethyl-4,4′-diphenyl ether diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1-methoxyphenyl-2,4-diisocyanate, isophorone diisocyanate, 4, Examples thereof include 4′-dicyclohexylmethane diisocyanate and tetramethylxylylene diisocyanate, and these can be used alone or in combination of two or more. Such a high molecular weight polycarbodiimide may be synthesized or a commercially available product may be used.

  Examples of commercially available carbodiimide group-containing compounds include Carbodilite (registered trademark) series manufactured by Nisshinbo Chemical Co., Ltd. Among them, carbodilite (registered trademark) V-01, V-02B, V-03, V -04K, V-4PF, V-05, V-07, V-09, and V-09GB are preferable in terms of excellent compatibility with organic solvents.

  Moreover, the carbodiimide equivalent when using the said carbodiimide group containing compound becomes like this. Preferably it is 50-10,000, Especially 100-1,000, Furthermore, it is preferable that it is 150-500. In addition, a carbodiimide equivalent shows the chemical formula amount per carbodiimide group.

  As said epoxy group containing compound, a glycidyl ester compound, a glycidyl ether compound, etc. are preferable, for example.

  Specific examples of the glycidyl ester compound include, for example, glycidyl benzoate, t-butyl-glycidyl benzoate, p-toluic acid glycidyl ester, cyclohexanecarboxylic acid glycidyl ester, pelargonic acid glycidyl ester, stearic acid glycyl ester, lauric acid Glycidyl ester, palmitic acid glycidyl ester, behenic acid glycidyl ester, versatic acid glycidyl ester, oleic acid glycidyl ester, linoleic acid glycidyl ester, linolenic acid glycidyl ester, behenolic acid glycidyl ester, stearolic acid glycidyl ester, terephthalic acid diglycidyl ester, Isophthalic acid diglycidyl ester, phthalic acid diglycidyl ester, naphthalenedicarboxylic acid diglyceride Diglycidyl ester, methyl terephthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, cyclohexanedicarboxylic acid diglycidyl ester, adipic acid diglycidyl ester, succinic acid diglycidyl ester, sebacic acid diglycidyl ester, Examples include dodecanedioic acid diglycidyl ester, octadecanedicarboxylic acid diglycidyl ester, trimellitic acid triglycidyl ester, pyromellitic acid tetraglycidyl ester, and the like. These may be used alone or in combination of two or more.

  Specific examples of the glycidyl ether compound include, for example, phenylglycidyl ether, o-phenylglycidyl ether, 1,4-bis (β, γ-epoxypropoxy) butane, 1,6-bis (β, γ- Epoxypropoxy) hexane, 1,4-bis (β, γ-epoxypropoxy) benzene, 1- (β, γ-epoxypropoxy) -2-ethoxyethane, 1- (β, γ-epoxypropoxy) -2- Benzyloxyethane, 2,2-bis- [р- (β, γ-epoxypropoxy) phenyl] propane, 2,2-bis- (4-hydroxyphenyl) propane and 2,2-bis- (4-hydroxyphenyl) ) Bisglycidyl polyether obtained by reaction of bisphenol such as methane and epichlorohydrin, and the like are mentioned alone or in combination It can be used in combination.

As the oxazoline group-containing compound, a bisoxazoline compound or the like is preferable. Specifically, for example, 2,2'-bis (2-oxazoline), 2,2'-bis (4-methyl-2-oxazoline), 2,2'-bis (4,4-dimethyl-2-) Oxazoline), 2,2′-bis (4-ethyl-2-oxazoline), 2,2′-bis (4,4′-diethyl-2-oxazoline), 2,2′-bis (4-propyl-2) -Oxazoline), 2,2'-bis (4-butyl-2-oxazoline), 2,2'-bis (4-hexyl-2-oxazoline), 2,2'-bis (4-phenyl-2-oxazoline) ), 2,2′-bis (4-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-pheny Bis (2-oxazoline), 2,2′-p-phenylenebis (4-methyl-2-oxazoline), 2,2′-p-phenylenebis (4,4-dimethyl-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′-octamethylenebis (2-oxazoline), 2,2′-decamethylenebis (2-oxazoline), 2,2′-ethylenebis (4-methyl-2-oxazoline), 2,2′-tetramethylenebis (4,4-dimethyl-2-oxazoline), 2,2′-9, 9'-Difeno Examples thereof include sietanbis (2-oxazoline), 2,2′-cyclohexylenebis (2-oxazoline), 2,2′-diphenylenebis (2-oxazoline), and among these, 2,2 '-Bis (2-oxazoline) is most preferred from the viewpoint of reactivity with polyester.
These may be used alone or in combination of two or more.

As these hydrolysis inhibitors [III], those having lower volatility are preferred, and therefore, it is preferred to use those having a high number average molecular weight, usually 300 to 15,000, preferably 1,000 to 10,000. Use one.
Moreover, as a hydrolysis inhibitor [III], it is preferable to use what has a high weight average molecular weight from a hydrolysis-resistant viewpoint. The weight average molecular weight of the hydrolysis inhibitor [III] is preferably 500 or more, more preferably 2,000 or more, and further preferably 3,000 or more. The upper limit of the weight average molecular weight is usually 50,000.
If the molecular weight of the hydrolysis inhibitor [III] is too small, the hydrolysis resistance tends to decrease. On the other hand, when the molecular weight is too large, the compatibility with the polyester resin [I] tends to decrease.

In addition, the weight average molecular weight in the present specification is a weight average molecular weight in terms of standard polystyrene molecular weight, and a column: TSKgel SuperMultipore HZ-M (exclusion limit molecular weight: Tosoh Corporation, HLC-8320GPC). 2 × 10 ⁶ , theoretical plate number: 16,000 plate / line, filler material: styrene-divinylbenzene copolymer, filler particle size: 4 μm) are used in series.

The content of the hydrolysis inhibitor [III] is preferably 0.01 to 10 parts by weight, particularly preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the polyester resin [I]. More preferably, it is 0.2 to 3 parts by weight, particularly preferably 0.3 to 1.5 parts by weight.
If the content is too large, turbidity tends to occur due to poor compatibility with the polyester resin [I], and if it is too small, sufficient durability tends to be difficult to obtain.

Further, the content of the hydrolysis inhibitor [III] is preferably optimized according to the acid value of the polyester resin [I], and the polyester resin [I in the pressure-sensitive adhesive composition [I] ] The molar ratio (T) of the total number of moles of the functional group of the hydrolysis inhibitor [III] in the pressure-sensitive adhesive composition to the total number of moles of the acidic functional group of] is 0.5 ≦ (T). Is preferable, particularly preferably 1 ≦ (T) ≦ 1,000, and more preferably 1.5 ≦ (T) ≦ 100.
When the molar ratio (T) is too low, the heat and humidity resistance tends to be reduced. On the other hand, when the molar ratio (T) is too high, the compatibility with the polyester resin [I] tends to decrease, and the adhesive strength, cohesive strength, and durability tend to decrease.

<Crosslinking agent [IV]>
Examples of the crosslinking agent [IV] include compounds having a functional group that reacts with at least one of a hydroxyl group and a carboxy group contained in the polyester resin [I], such as a polyisocyanate compound and a polyepoxy compound. Among these, it is particularly preferable to use a polyisocyanate compound from the viewpoint that both initial adhesive strength, mechanical strength, and heat resistance can be balanced.

  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 xylylene diisocyanate, 1 Polyisocyanates such as 1,5-naphthalene diisocyanate and triphenylmethane triisocyanate, adducts of the above polyisocyanates with polyol compounds such as trimethylolpropane, burettes of these polyisocyanate compounds, isocyanurates Examples include the body. In addition, the said polyisocyanate type-compound can also use what the isocyanate part was blocked by phenol, lactam, etc. These crosslinking agents [IV] may be used alone or in a combination of two or more.

The content of the crosslinking agent [IV] can be appropriately selected depending on the molecular weight of the polyester resin [I] and the purpose of use, but usually one equivalent of at least one of a hydroxyl group and a carboxy group contained in the polyester resin [I]. In contrast, the reactive group contained in the crosslinking agent [IV] preferably contains the crosslinking agent [IV] in a ratio of 0.2 to 10 equivalents, particularly preferably 0.5 to 5 equivalents, Preferably it is 0.5-3 equivalent.
If the number of equivalents of reactive groups contained in the crosslinking agent [IV] is too small, the cohesive force tends to decrease, and if it is too large, the flexibility tends to decrease.

  In the reaction between the polyester resin [I] and the crosslinking agent [IV], an organic solvent having no functional group that reacts with these [I] and [IV] components, for example, an ester such as ethyl acetate or butyl acetate. , Organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone, and aromatics such as toluene and xylene can be used. These may be used alone or in combination of two or more.

<Urethaneization catalyst [V]>
As said urethanization catalyst [V], an organometallic compound, a tertiary amine compound, etc. can be used, for example. These may be used alone or in combination of two or more.

Examples of the organometallic compound include a zirconium compound, an iron compound, a tin compound, a titanium compound, a lead compound, a cobalt compound, and a zinc compound.
Examples of the zirconium-based compound include zirconium naphthenate and zirconium acetylacetonate.
Examples of iron-based compounds include iron acetylacetonate and iron 2-ethylhexanoate.
Examples of tin compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dilaurate, and the like.
Examples of titanium compounds include dibutyltitanium dichloride, tetrabutyltitanate, butoxytitanium trichloride, and the like.
Examples of the lead-based compound include lead oleate, lead 2-ethylhexanoate, lead benzoate, lead naphthenate and the like.
Examples of cobalt compounds include cobalt 2-ethylhexanoate and cobalt benzoate.
Examples of the zinc-based compound include zinc naphthenate and zinc 2-ethylhexanoate.

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

  Among these urethanization catalysts [V], organometallic compounds are preferred, particularly preferred are zirconium compounds, and particularly preferred are zirconium acetylacetonate, in terms of reaction rate and pot life of the pressure-sensitive adhesive layer. .

<Catalytic action inhibitor>
The pressure-sensitive adhesive composition of the present invention preferably contains a catalytic action inhibitor in the urethanization catalyst [V] in terms of extending pot life and improving coatability.
Examples of the catalyst inhibitor include β-ketoesters such as methyl acetoacetate, ethyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, stearyl acetoacetate, acetylacetone, 2,4-hexanedione, and benzoylacetone. Β-diketones such as These are ketoenol tautomeric compounds, and by protecting the urethanization catalyst [V], the catalyst activity in the solution state of the urethanization catalyst [V] is reduced, and the pressure-sensitive adhesive composition after mixing is excessive. An increase in viscosity and gelation can be suppressed, and the pot life of the pressure-sensitive adhesive composition can be extended.
Among these, it is preferable to use acetylacetone as a catalyst inhibitor from the viewpoint of the balance between pot life and curing rate. In addition, these catalytic action inhibitors can be used alone or in combination of two or more.
The blending ratio (weight ratio) of the catalyst inhibitor and the urethanization catalyst [V] is preferably in the range of catalyst inhibitor: urethanization catalyst [V] = 0.001: 1 to 15: 1, 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 small relative to the content of the urethanization catalyst [V], the pot life tends to be short and the coating property tends to decrease, and if too large, the curing rate tends to decrease.

<Antioxidant>
The pressure-sensitive adhesive composition of the present invention preferably further contains an antioxidant in terms of improving heat resistance. By containing the antioxidant, a decrease in the molecular weight of the polyester resin [I] in a heat resistant environment is suppressed, and the adhesive residue preventing property to the adherend is excellent.
As the antioxidant, an antioxidant having a hindered phenol structure is preferable.
As an antioxidant having a hindered phenol structure, for example, a group having a large steric hindrance such as a tertiary butyl group is bonded to at least one of the adjacent carbon atoms on the aromatic ring to which the hydroxyl group of phenol is bonded. An antioxidant having a hindered phenol structure is exemplified. By using such an antioxidant, the effect of suppressing a decrease in the molecular weight of the polyester resin [I] in a heat-resistant environment becomes very high.
The content of the antioxidant is preferably 0.01 to 10 parts by weight, more preferably 0.03 to 8 parts by weight, and still more preferably 0 with respect to 100 parts by weight of the polyester resin [I]. 0.05 to 5 parts by weight.
If the content is too small, adhesive residue tends to be generated on the adherend, and if the content is too large, the physical properties of the adhesive tend to decrease.

  In addition to the above additives, the pressure-sensitive adhesive composition of the present invention may contain a small amount of impurities contained in the raw materials for producing the constituents of the pressure-sensitive adhesive composition.

  Such a pressure-sensitive adhesive composition is prepared by, for example, preparing the polyester resin [I], the hygroscopic filler [II] and necessary optional components, and blending and dispersing the polyester resin [I] during production. Or it can obtain by mix | blending in the polyester-type resin [I] solution dissolved with the organic solvent, and making it disperse | distribute using a mixing roller.

  The pressure-sensitive adhesive according to the present invention is composed of the above pressure-sensitive adhesive composition, that is, the pressure-sensitive adhesive composition is crosslinked (cured).

And the adhesive sheet of this invention is an adhesive sheet which has an adhesive layer in the single side | surface or both surfaces of a support base material, and is especially suitable as an adhesive sheet for optical members used for bonding of an optical member.
In the present invention, “sheet” means “film” and “tape”.

<Adhesive sheet>
An adhesive sheet can be produced as follows, for example.
As a method for producing such a pressure-sensitive adhesive sheet, it can be produced in accordance with a known general method for producing a pressure-sensitive adhesive sheet. For example, the pressure-sensitive adhesive composition is applied to one surface of a base material and dried to obtain a pressure-sensitive adhesive. A pressure-sensitive adhesive layer in which a pressure-sensitive adhesive composition is crosslinked on a substrate by forming a layer, bonding a release sheet to the surface (the surface opposite to the surface in contact with the substrate), and curing as necessary. A pressure-sensitive adhesive sheet of the present invention having the following is obtained.

  In addition, the pressure-sensitive adhesive composition is coated on the release sheet and dried to form a pressure-sensitive adhesive layer, and a substrate is bonded to the surface (opposite the surface in contact with the release sheet). The pressure-sensitive adhesive sheet of the present invention can also be obtained by curing.

  Then, a pressure-sensitive adhesive layer is formed on the release sheet, and the release sheet and another release sheet are bonded to the surface (the surface opposite to the surface in contact with the release sheet). Can be manufactured.

  At the time of use, the obtained pressure-sensitive adhesive sheet or substrate-less double-sided pressure-sensitive adhesive sheet peels the release sheet from the pressure-sensitive adhesive layer and bonds the pressure-sensitive adhesive layer and the adherend.

  Examples of the substrate include polyester resins such as polyethylene naphthalate, polyethylene terephthalate, boribylene terephthalate, and polyethylene terephthalate / isophthalate copolymer; polyolefin resins such as polyethylene, polypropylene, and polymethylpentene; polyvinyl fluoride, Polyfluorinated ethylene resins such as polyvinylidene fluoride and polyfluorinated ethylene; polyamides such as nylon 6 and nylon 6,6; polyvinyl chloride, polyvinyl chloride / vinyl acetate copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl Alcohol copolymers, vinyl polymers such as polyvinyl alcohol and vinylon; cellulose resins such as cellulose triacetate and cellophane; polymethyl methacrylate, polyethyl methacrylate, polyethyl acrylate Acrylic resin such as polybutyl acrylate; polystyrene; polycarbonate; polyarylate; polyimide; synthetic resin sheet such as cycloolefin polymer; metal foil of aluminum, copper, iron; paper such as fine paper, glassine paper; glass fiber, natural Examples thereof include woven fabrics and nonwoven fabrics made of fibers, synthetic fibers and the like. These base materials can be used as a single layer body or a multilayer body in which two or more kinds are laminated.

  Among these, a base material made of polyethylene terephthalate and polyimide is particularly preferable, polyethylene terephthalate is particularly preferable in terms of excellent adhesiveness with a pressure-sensitive adhesive, and further, the base material is a polyethylene terephthalate having a metal thin film layer. It is preferable in that it is excellent in adhesive strength between the adhesive and the adhesive, can stably maintain the base material without corroding the metal thin film layer, and can exert the effect of the adhesive used in the present invention remarkably.

  In the present invention, the ITO electrode film has an adhesive layer on the PET side of the film in which the thin film is formed on the polyethylene terephthalate (PET) substrate, and the PET substrate and the polycarbonate (PC) are interposed through the adhesive layer. It is also preferable to form an optical laminate in which an acrylic film is laminated and an acrylic film is laminated (layer structure: ITO electrode film / PET substrate / adhesive layer / PC film / acrylic film).

  As the release sheet, for example, various synthetic resin sheets exemplified in the base material, paper, cloth, non-woven fabric and the like can be used. Of these, it is preferable to use a silicon-based release sheet as the release sheet.

  As thickness of the said base material, it is preferable that it is 1-1000 micrometers, for example, Especially preferably, it is 2-500 micrometers, More preferably, it is 3-300 micrometers.

  Examples of the method for applying the pressure-sensitive adhesive composition include a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, a spray coater, and a comma coater.

  As conditions for the above curing treatment, the temperature is usually room temperature (23 ° C.) to 70 ° C., and the time is usually 1 to 30 days. Specifically, for example, the temperature is 23 ° C. for 1 to 20 days, preferably 3 hours at 23 ° C. What is necessary is just to carry out on conditions, such as 1 to 10 days at 40 degreeC for -14 days.

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

  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 preferably 2 to 500 μm, particularly preferably 5 to 200 μm, and more preferably 10 to 100 μm. If the thickness of the pressure-sensitive adhesive layer is too thin, the adhesive strength tends to decrease. If the thickness is too thick, it is difficult to apply uniformly, and problems such as bubbles entering the coating film tend to occur. is there. In consideration of impact absorption, the thickness is preferably 50 μm or more.

  In addition, the thickness of the said adhesive layer uses a dimatic indicator (Mitutoyo company make, ID-C112B), and subtracts the measured value of the thickness of structural members other than an adhesive layer from the measured value of the thickness of the whole adhesive sheet. Is a value obtained by

  About the gel fraction of the said adhesive layer, it is preferable that it is 10 weight% or more from the point of durability and adhesive force, Most preferably, it is 15-95 weight%, More preferably, it is 20-90 weight%. If the gel fraction is too low, durability tends to decrease due to a decrease in cohesion. If the gel fraction is too high, there is a concern that the adhesive force is reduced due to the increase in cohesive force.

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 sheet (not provided with a separator) in which a pressure-sensitive adhesive layer is formed on a polymer sheet (for example, a PET film) as a base material is wrapped with a 200-mesh SUS wire mesh, and 23 ° C. in toluene. X It is immersed for 24 hours, and the weight percentage of the insoluble adhesive component remaining in the wire mesh after immersion with respect to the weight of the adhesive component before immersion is defined as the gel fraction. However, the weight of the substrate is subtracted.

  Furthermore, this pressure sensitive adhesive sheet may protect the pressure sensitive adhesive layer by providing a release sheet outside the pressure sensitive adhesive layer as necessary. Further, in the pressure-sensitive adhesive sheet in which the pressure-sensitive adhesive layer is formed on one side of the base material, the pressure-sensitive adhesive layer is utilized by using the above-mentioned release-treated surface by subjecting the surface on the opposite side of the base material to the pressure-sensitive adhesive layer. It is also possible to protect.

  Moreover, although the adhesive of this invention can be used for bonding of various members, it is preferable to use as an adhesive for optical members used especially for bonding of an optical member. The above-mentioned optical member with the pressure-sensitive adhesive layer can be obtained by forming a pressure-sensitive adhesive layer of the pressure-sensitive adhesive composition on the optical member.

Such optical members include ITO electrode films, transparent electrode films such as inorganic and organic conductive films such as polythiophene, polarizing plates, retardation plates, elliptical polarizing plates, optical compensation films, brightness enhancement films, electromagnetic wave shielding films, An infrared absorption film, AR (anti-reflection) film, etc. are mentioned. Among these, it is effective when the optical member is a transparent electrode film, and is preferable in that high adhesive force can be obtained, and an ITO electrode film is particularly preferable. The ITO electrode film is often formed as a thin film on a substrate such as glass or PET, but in the present invention, a film in which the ITO electrode film is formed as a thin film on a PET substrate may be used. Particularly preferred.
Moreover, it is suitable also for the light extraction film provided in the light emission surface of the surface light-emitting body of an organic EL element, or the light-diffusion sheet | seat of a liquid crystal display.

  In the optical member with the pressure-sensitive adhesive layer, it is preferable to further provide a release film on the surface opposite to the optical member surface of the pressure-sensitive adhesive layer, and when put to practical use, the release film is peeled off, Adhesive layer and adherend are bonded together. As such a release film, it is preferable to use a silicon-based release film.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded. In the examples, “parts” and “%” mean weight basis (excluding “haze change”).
Moreover, regarding the measurement of the glass transition temperature of polyester-type resin [I] in the following Example, it measured according to the above-mentioned method.

<Production of polyester resin [I]>
The mol% of the polyvalent carboxylic acids (A) described in the following production examples indicates a molar ratio when the total amount of the polyvalent carboxylic acids (A) is 100 mol%.
Moreover, the mol% of the polyol (B) described in the following production examples indicates a molar ratio when the total amount of the polyol (B) is 100 mol%.

[Production of Polyester Resin [I-1]]
In a reaction vessel equipped with a heating device, a thermometer, a stirrer, a rectifying column, a nitrogen introducing tube and a vacuum device, 248.3 parts of isophthalic acid (IPA) and sebacic acid (SebA) 129 as polyvalent carboxylic acids (A) .6 parts, 1,4-butanediol (1,4BG) 96.2 parts as polyol (B), neopentyl glycol (NPG) 200.2 parts, 1,6-hexanediol (1,6HG) 21.4 Parts, trimethylolpropane (TMP) 4.3 parts, hygroscopic filler [II] (manufactured by Kyowa Chemical Industry Co., Ltd .; DTH-4A-2) 0.5 parts, zinc acetate 0.05 part as a catalyst, The temperature was gradually raised to 250 ° C., and the esterification reaction was carried out over 4 hours.
Thereafter, the internal temperature was raised to 260 ° C., 0.05 part of tetrabutyl titanate was added as a catalyst, the pressure was reduced to 1.33 hPa, and a polymerization reaction was performed for 3 hours to produce a polyester resin [I-1].
The obtained polyester resin [I-1] has a glass transition temperature of 3.0 ° C., and a finished component ratio of isophthalic acid / sebacic acid = 70 mol% / 30 mol% as polyol (A), polyol ( As B), 1,4-butanediol / neopentylglycol / 1,6-hexanediol / trimethylolpropane = 34 mol% / 58.5 mol% / 6 mol% / 1.5 mol%.

[Production of polyester resin [I-2]]
In a reaction vessel equipped with a heating device, a thermometer, a stirrer, a rectifying column, a nitrogen inlet tube and a vacuum device, 236.5 parts of isophthalic acid (IPA) as polyvalent carboxylic acids (A), and sebacic acid (SebA) 141 8 parts, 0.3 part of dimethyl sodium 5-sulfoisophthalate (SIPM), 95.7 parts of 1,4-butanediol (1,4BG) as polyol (B), 221.3 parts of neopentyl glycol (NPG) , 4.3 parts of trimethylolpropane (TMP), 0.5 part of hygroscopic filler [II] (manufactured by Kyowa Chemical Industry Co., Ltd., KW-2200), 0.05 part of zinc acetate as a catalyst, up to an internal temperature of 250 ° C. The temperature was gradually raised and the esterification reaction was carried out over 4 hours.
Thereafter, the internal temperature was raised to 260 ° C., 0.05 part of tetrabutyl titanate was charged as a catalyst, the pressure was reduced to 1.33 hPa, and a polymerization reaction was performed for 3 hours to produce a polyester resin [I-2].
The obtained polyester resin [I-2] has a glass transition temperature of 4.9 ° C., and the resulting component ratio of polycarboxylic acids (A) is isophthalic acid / sebacic acid / 5-sulfoisophthalic acid dimethyl sodium = 66. 97 mol% / 32.98 mol% / 0.05 mol%, 1,4-butanediol / neopentylglycol / trimethylolpropane as the polyol (B) = 33.8 mol% / 64.7 mol% / 1. It was 5 mol%.

[Production of polyester resin [I-3]]
In a reaction vessel equipped with a heating device, a thermometer, a stirrer, a rectifying column, a nitrogen introducing tube and a vacuum device, 248.3 parts of isophthalic acid (IPA) and sebacic acid (SebA) 129 as polyvalent carboxylic acids (A) .6 parts, 1,4-butanediol (1,4BG) 96.2 parts as polyol (B), neopentyl glycol (NPG) 200.2 parts, 1,6-hexanediol (1,6HG) 21.4 Part, trimethylolpropane (TMP) 4.3 parts, and 0.05 parts of zinc acetate as a catalyst were added, the temperature was gradually raised to an internal temperature of 250 ° C., and the esterification reaction was carried out over 4 hours.
Thereafter, the internal temperature was raised to 260 ° C., 0.05 part of tetrabutyl titanate was charged as a catalyst, the pressure was reduced to 1.33 hPa, and a polymerization reaction was performed over 3 hours to produce a polyester resin [I-3].
The obtained polyester resin [I-3] has a glass transition temperature of 1.0 ° C., and a finished component ratio of isophthalic acid / sebacic acid = 70 mol% / 30 mol% as a polyvalent carboxylic acid (A), polyol ( B) 1,4-butanediol / neopentylglycol / 1,6-hexanediol / trimethylolpropane (TMP) = 34 mol% / 58.5 mol% / 6.2 mol% / 1.3 mol% there were.

  The results of the resin composition (component-derived structural unit) and glass transition temperature (Tg) of the obtained polyester resin [I] are also shown in Table 1 below.

<Manufacture of an adhesive composition>
Using the polyester resins [I-1], [I-2] and [I-3] obtained above, pressure-sensitive adhesive compositions were produced as follows.

Example 1
The polyester resin [I-1] obtained above is diluted with toluene to a solid content concentration of 50%, and a hydrolysis inhibitor [100 parts as a solid content] is added to this polyester resin [I-1] solution (100 parts as a solid content). III] (Nisshinbo Chemical Co., Ltd., Carbodilite V-09BG) 0.7 parts (solid content), and trimethylolpropane / tolylene diisocyanate adduct (Tosoh Corp., Coronate L55E) 4 parts (solid) ), 0.02 part (solid content) of a zirconium-based compound (Matsumoto Fine Chemical Co., Ltd., ORGATIZ ZC-150) diluted to a solid content concentration of 1% as urethanization catalyst [V] is mixed, stirred and mixed. As a result, a pressure-sensitive adhesive composition was obtained.

(Example 2)
In Example 1, the polyester resin [I-1] was changed to the polyester resin [I-2], and the amount of the crosslinking agent [IV] was changed to 5 parts (solid content). In the same manner as above, a pressure-sensitive adhesive composition was obtained.

(Comparative Example 1)
In Example 1, the polyester resin [I-1] was changed to the polyester resin [I-3], and the amount of the crosslinking agent [IV] was changed to 2.5 parts (solid content). Other than that was carried out similarly to Example 1, and obtained the adhesive composition. That is, in Comparative Example 1, the hygroscopic filler [II] is not used.

  Using the obtained pressure-sensitive adhesive composition, evaluation was performed as follows, and the results are shown in Table 2 below.

<Preparation of double-sided pressure-sensitive adhesive sheet>
The pressure-sensitive adhesive composition obtained in Examples 1 and 2 and Comparative Example 1 was coated with an applicator on a PET release film having a thickness of 100 μm (SP-PET-03-BU, manufactured by Mitsui Chemicals Tosero Co., Ltd.) (α). And then dried at 100 ° C. for 4 minutes to obtain a pressure-sensitive adhesive sheet with a release film having a pressure-sensitive adhesive layer thickness of 50 μm.
Next, the surface of the pressure-sensitive adhesive layer of the obtained pressure-sensitive adhesive sheet with a release film is a PET release film having a thickness different from that of the release film (α) and having a thickness of 38 μm (manufactured by Mitsui Chemicals, Inc. -BU) (β) and a curing treatment at 40 ° C. for 4 days to obtain a substrate-less double-sided PSA sheet.

<Adhesive sheet evaluation>
[Haze change]
The release film (β) on one side was peeled off from the pressure-sensitive adhesive layer of the substrate-less double-sided pressure-sensitive adhesive sheet obtained above, and the pressure-sensitive adhesive layer was transferred to a PET film (100 μm) to prepare a pressure-sensitive adhesive sheet for evaluation. . The separator on the other side was peeled from the obtained pressure-sensitive adhesive sheet for evaluation, and the exposed pressure-sensitive adhesive layer was bonded to an alkali-free glass plate (Corning Corp., Eagle XG), followed by autoclaving (50 ° C., The test piece having a configuration of PET film / adhesive layer / non-alkali glass plate was produced by pressure bonding at 0.5 MPa for 20 minutes.
The test piece is subjected to a wet heat test (85 ° C., 85% RH, 100 hours), and the haze before the test and 30 minutes after the test is taken out is measured using a HAZE MATER NDH2000 (manufactured by Nippon Denshoku Industries Co., Ltd.). The displacement was calculated and evaluated according to the following criteria. The results are also shown in Table 2 below. This machine complies with JIS K7361-1.
(Evaluation criteria)
Haze displacement (%) = Haze value after wet heat test (%) − Haze value before wet heat test (%)
◎ (very good) ... Haze displacement is less than 5%.
○ (Good): Haze displacement of 5 or more and less than 10%.
Δ (Normal): Haze displacement of 10 or more and less than 15%.
X (Poor) ... Haze displacement of 15% or more.

[Adhesion under high temperature: 180 degree peel strength (N / 25mm)]
The release film (β) on one surface was peeled off from the substrate-less double-sided pressure-sensitive adhesive sheet obtained above, and the adhesive layer was transferred to a PET film (100 μm) to prepare a pressure-sensitive adhesive sheet for evaluation. The separator on the other side was peeled off from the obtained pressure-sensitive adhesive sheet for evaluation, and the exposed pressure-sensitive adhesive layer was bonded to a polycarbonate plate (manufactured by Mitsubishi Chemical Corporation, Stella), and then autoclaved (50 ° C., 0. A test piece having a configuration of PET film / adhesive layer / polycarbonate plate was produced by pressure bonding at 5 MPa for 20 minutes.
About the said test piece, 180 degree | times peel strength was measured by the peeling rate of 300 mm / min on 85 degreeC conditions using the tensile testing machine with a thermostat (Shimadzu Corp. make, autograph AGS-H 500N). The results are also shown in Table 2.

[Blister resistance]
The release film (β) on one surface was peeled off from the substrate-less double-sided pressure-sensitive adhesive sheet obtained above, and the adhesive layer was transferred to a PET film (100 μm) to prepare a pressure-sensitive adhesive sheet for evaluation. The separator on the other side was peeled off from the obtained pressure-sensitive adhesive sheet for evaluation, and the exposed pressure-sensitive adhesive layer was bonded to a polycarbonate plate (manufactured by Mitsubishi Chemical Corporation, Stella), and then autoclaved (50 ° C., 0. A test piece having a configuration of PET film / adhesive layer / polycarbonate plate was produced by pressure bonding at 5 MPa for 20 minutes.
About the said test piece, the load was applied for 24 hours with a thermostat (85 degreeC, 85% RH), the external appearance (the presence or absence of foaming) of the test piece after a load was observed visually, and the following reference | standard evaluated. The results are also shown in Table 2.
(Evaluation criteria)
◎ (very good): No foaming and no change in appearance.
○ (Good): The portion where foaming occurred was 1/4 or less of the area of the test piece.
Δ (Normal): The portion where foaming occurred was more than ¼ of the area of the test piece and ½ or less.
X (Poor): The portion where foaming occurred exceeded 1/2 of the area of the test piece.

From the results of Table 2 above, it can be seen that the pressure-sensitive adhesive compositions of Examples 1 and 2 are not only excellent in high-temperature adhesiveness and blister resistance, but also have very little haze change even under high-temperature and high-humidity conditions.
On the other hand, the pressure-sensitive adhesive composition of Comparative Example 1 was excellent in high-temperature pressure-sensitive adhesiveness and blister resistance, but had a very large haze change and poor performance as a pressure-sensitive adhesive.
In general, it is known that a pressure-sensitive adhesive composition using a urethane-based resin or an acrylic resin has low adhesive strength at high temperatures and poor blister resistance. Therefore, in the present invention, it is important to use the polyester-based resin [I]. Furthermore, by using the polyester-based resin [I] and the hygroscopic filler [II] in combination, The pressure-sensitive adhesive composition is excellent in change, tackiness, and blister resistance.

  The pressure-sensitive adhesive composition of the present invention is excellent in all of haze change, pressure-sensitive adhesiveness, and blister resistance under high-temperature and high-humidity conditions. Therefore, the pressure-sensitive adhesive and pressure-sensitive adhesive sheet using the same are a display and an optical film constituting the display. In an optical member such as a base material or the like, it can be suitably used for bonding the optical member.

Claims (13)

  A polyester-based pressure-sensitive adhesive composition comprising a polyester-based resin [I] and a hygroscopic filler [II].   The polyester pressure-sensitive adhesive composition according to claim 1, wherein the polyester-based resin [I] has a glass transition temperature (Tg) of -20 to 30 ° C.   The polyester resin [I] has a structural unit derived from the polyvalent carboxylic acid (A) and a structural unit derived from the polyol (B), and the polyvalent carboxylic acid (A) is an aromatic dicarboxylic acid (a1). The polyester-based pressure-sensitive adhesive composition according to claim 1, wherein the polyol (B) contains a diol compound (b1) having a hydrocarbon group in the side chain.   The polyester pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the hygroscopic filler [II] is a forced dehydration of a metal inorganic compound containing crystal water.   Furthermore, hydrolysis inhibitor [III] is contained, The polyester-type adhesive composition as described in any one of Claims 1-4 characterized by the above-mentioned.   Furthermore, a crosslinking agent [IV] is contained, The polyester-type adhesive composition as described in any one of Claims 1-5 characterized by the above-mentioned.   Furthermore, the urethanization catalyst [V] is contained, The polyester-type adhesive composition as described in any one of Claims 1-6 characterized by the above-mentioned.   A pressure-sensitive adhesive obtained by crosslinking the polyester-based pressure-sensitive adhesive composition according to claim 1.   A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive according to claim 8.   The pressure-sensitive adhesive sheet according to claim 9, comprising a base material and a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer is provided on at least one side of the base material.   The pressure-sensitive adhesive sheet according to claim 9, wherein the pressure-sensitive adhesive sheet is a substrate-less type having no substrate.   It is used for bonding of an optical member, The adhesive sheet as described in any one of Claims 9-11 characterized by the above-mentioned. An optical member with an adhesive layer having an adhesive layer and an optical member, wherein the adhesive layer contains the adhesive according to claim 8.