JP2017115149A - Polyester pressure-sensitive adhesive composition, polyester pressure-sensitive adhesive, pressure-sensitive adhesive sheet for optical members, substrate-less double-sided pressure-sensitive adhesive sheet for optical members, optical member with pressure-sensitive adhesive layer, optical laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly durable polyester pressure-sensitive adhesive that is excellent in adhesive physical properties and transparency even when the pressure-sensitive adhesive layer is exposed to high temperature and high humidity.
SOLUTION: A polyester pressure-sensitive adhesive containing a polyester resin (A) and a hydrolysis inhibitor (B), wherein the glass transition temperature of the polyester resin (A) is −10 ° C. or lower. Polyester adhesive to be used [selection figure] None

Description

  The present invention relates to a polyester-based pressure-sensitive adhesive composition, and more particularly, to a polyester-based pressure-sensitive adhesive composition containing a hydrolysis inhibitor, and relates to a polyester-based pressure-sensitive adhesive composition excellent in durability and blister resistance. is there.

  Conventionally, polyester resins have excellent heat resistance, chemical resistance, durability, and mechanical strength, so they are used in a wide range of applications such as films, PET bottles, fibers, toners, electrical parts, and adhesives and adhesives. It has been.

  Regarding pressure-sensitive adhesives using polyester resin, when used for bonding optical members, etc., the pressure-sensitive adhesive is exposed to high temperature and high humidity. There was a problem of being lowered.

  As a technique for solving such a problem, for example, in Patent Document 1, a polyester-based pressure-sensitive adhesive composition containing a polyester, a hydrolysis-resistant agent, a tackifier, and a cross-linking agent, A polyester having a value of 8 or less, a softening point of the tackifier of 80 to 170 ° C., and containing 20 to 100 parts by weight of the tackifier with respect to 100 parts by weight of the polyester. Based pressure-sensitive adhesive compositions have been proposed.

  On the other hand, in recent years, display devices such as liquid crystal displays (LCDs) and input devices such as touch panels that combine the display devices and position input devices have been widely used in various fields. A transparent pressure-sensitive adhesive sheet, for example, a substrate-less double-sided pressure-sensitive adhesive sheet, is used for bonding optical members such as an optical film and a base material.

Here, a transparent base material is required for an optical member constituting an optical device such as a touch panel, and a glass base material has been used conventionally. However, in recent years, from the viewpoint of impact resistance and weight reduction, Instead of a glass substrate such as a protective cover or a glass substrate, a plastic substrate such as a polycarbonate resin, an acrylic resin, or a (cyclic) olefin resin is used.
However, when such a plastic base material is used, there is a problem that foaming or peeling occurs between the plastic base material and the pressure-sensitive adhesive layer due to gas or moisture generated from the plastic base material, resulting in a decrease in visibility. It was.

Therefore, the adhesive used for laminating optical members is required to have a high level of blister resistance that can suppress these.
In order to improve such blister resistance, for example, in Patent Document 2, a pressure-sensitive adhesive containing an acrylic polymer and a crosslinking agent, which is a structural unit derived from an alkyl acrylate monomer having an alkyl group having 4 to 20 carbon atoms. 30 to 77% by mass, 20 to 60% by mass of a structural unit derived from an alicyclic group-containing (meth) acrylate monomer, and 0.1 to 10.0% by mass of a structural unit derived from (meth) acrylic acid Agents have been proposed.

JP2015-134906A JP 2012-201877 A

  However, in the technique disclosed in Patent Document 1, although a hydrolysis-resistant agent is contained, hydrolysis of the polyester resin under high temperature and high humidity can be suppressed, but since it also contains a tackifier, coloring is performed at high temperature. It is easy to be used and difficult to use in applications where transparency is required for the pressure-sensitive adhesive layer.

  The technique disclosed in Patent Document 2 achieves blister resistance under certain conditions, but does not sufficiently satisfy the high level of blister resistance required in the market, and further improvement is desired. It was a thing.

  Therefore, in the present invention, under such a background, even when the pressure-sensitive adhesive layer is exposed to high temperature and high humidity, it is a highly durable polyester pressure-sensitive adhesive that is excellent in adhesive physical properties (adhesive strength) and transparency. It is another object of the present invention to provide a polyester pressure-sensitive adhesive composition capable of obtaining a polyester pressure-sensitive adhesive having excellent blister resistance.

  However, as a result of intensive studies in view of such circumstances, the present inventors have used a polyester-based resin having a lower glass transition temperature than usual in a polyester-based pressure-sensitive adhesive composition containing a hydrolysis inhibitor. Even without the use of a tackifier, a polyester-based pressure-sensitive adhesive that is excellent in both adhesive properties and transparency and excellent in blister resistance under conditions where durability is required (high temperature and high humidity) can be obtained. As a result, the present invention has been completed.

That is, the gist of the present invention is a polyester pressure-sensitive adhesive containing a polyester resin (A) and a hydrolysis inhibitor (B), and the glass transition temperature of the polyester resin (A) is −10 ° C. or lower. This is a polyester-based pressure-sensitive adhesive composition.
Furthermore, in this invention, it is related also with the polyester-type adhesive, the adhesive sheet for optical members, the base material less double-sided adhesive sheet for optical members, the optical member with an adhesive layer, and an optical laminated body.

  The polyester-based pressure-sensitive adhesive composition of the present invention is excellent in both adhesive properties (adhesive strength) and transparency under conditions requiring durability (high temperature and high humidity), and blister resistance in harsh environments It is possible to obtain a pressure-sensitive adhesive having excellent properties, and also has a good tack feeling, so that it is excellent in workability and can be suitably used for bonding optical members, and in particular, an optical member made of a plastic material. It can be suitably used for bonding.

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 acid” includes carboxylic acid derivatives such as carboxylic acid salts, carboxylic acid anhydrides, carboxylic acid halides, and carboxylic acid esters in addition to carboxylic acid.

<Polyester resin (A)>
The polyester resin (A) used in the present invention has a glass transition temperature of −10 ° C. or lower, preferably −80 to −10 ° C., particularly preferably −70 to −15 ° C. More preferably, it is -70 to -20 degreeC.
When the glass transition temperature exceeds the upper limit, the flexibility is lost, the initial adhesiveness is lowered, it becomes difficult to exert sufficient adhesiveness at a pressure of about finger pressure, workability is deteriorated, and the object of the present invention is achieved. Cannot be achieved.
Here, the glass transition temperature (Tg) of the polyester resin is a value measured using a differential scanning calorimeter DSC Q20 manufactured by TA Instruments.
The measurement temperature range is from -90 ° C to 100 ° C, and the temperature increase rate is 10 ° C / min.

  The polyester-based resin (A) used in the present invention is obtained by copolymerizing a copolymer component including a polyvalent carboxylic acid component (A1) and a polyol component (A2) as constituent raw materials.

[Polyvalent carboxylic acid component (A1)]
As the polyvalent carboxylic acid component (A1) used in the present invention, for example,
Aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, benzylmalonic acid, diphenic acid, 4,4'-oxydibenzoic acid, naphthalenedicarboxylic acid;
Malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, thiodipropionic acid , Aliphatic dicarboxylic acids such as diglycolic acid;
Alicyclics such as 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2,5-norbornanedicarboxylic acid, adamantanedicarboxylic acid, etc. Dicarboxylic acids;
And other divalent carboxylic acids.
These may be used alone or in combination of two or more.

  Among these, from the viewpoint of imparting cohesive force, it is preferable to include an aromatic dicarboxylic acid, and it is particularly preferable to include isophthalic acid.

  The content ratio of the aromatic dicarboxylic acid is preferably 50 mol% or less, particularly preferably 5 to 40 mol%, more preferably 10 to 30 mol, based on the entire polyvalent carboxylic acid component (A1). %. If the content is too high, the glass transition temperature tends to be high and sufficient adhesive performance tends to be not obtained.

  Moreover, it is preferable that aliphatic dicarboxylic acid is included from the point which provides a tuck feeling, It is preferable that C4-C12 aliphatic dicarboxylic acid is included especially, and it is preferable that sebacic acid is included further.

  The content ratio of the aliphatic dicarboxylic acid is preferably 20 mol% or more, particularly preferably 50 mol% to 95 mol%, more preferably 70 to 90, based on the entire polyvalent carboxylic acid component (A1). Mol%. If the content is too low, there is a tendency that the glass transition temperature becomes high and sufficient adhesive strength cannot be obtained. If the content is too high, the adhesion component decreases, resulting in a decrease in adhesive strength to the polar adherend. Tend to.

  In the present invention, it is preferable to use an aromatic dicarboxylic acid and an aliphatic dicarboxylic acid in combination as the polyvalent carboxylic acid component (A1) from the viewpoint of the balance of adhesive properties, and the content ratio (molar ratio) is aromatic. Dicarboxylic acid / aliphatic dicarboxylic acid is preferably 1/99 to 90/10, particularly preferably aromatic dicarboxylic acid / aliphatic dicarboxylic acid = 5/95 to 49/51, and more preferably aromatic dicarboxylic acid / Aliphatic dicarboxylic acid = 10/90 to 30/70.

For the purpose of increasing the branch point in the polyester resin (A), a trivalent or higher polyvalent carboxylic acid can be used. Examples of the trivalent or higher carboxylic acid include trimellitic acid and pyromellitic acid. , Adamantanetricarboxylic acid, trimesic acid and the like. Among them, it is preferable to use trimellitic acid from the viewpoint that gelation hardly occurs.
The content ratio of the trivalent or higher polyvalent carboxylic acid is preferably 10 mol% or less, particularly preferably based on the whole polyvalent carboxylic acid component (A1) in that the cohesive force of the pressure-sensitive adhesive can be increased. Is 0.1 to 5 mol%, and if the content is too large, gelation tends to occur during the production of the polyester resin.

[Polyol component (A2)]
As the polyol component (A2) used in the present invention, for example,
Ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, 2-methyl-1,3-propanediol 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1 , 3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,6- Aliphatic diols such as 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 Aromatic diols such as ethylene oxide and propylene oxide adducts of
And dihydric alcohols.
These may be used alone or in combination of two or more.

  Among these, aliphatic diols and alicyclic diols are preferable from the viewpoint of excellent reactivity, and particularly preferable aliphatic diols are ethylene glycol, 1,3-propanediol, and 2-methyl-1,3-propane. Diol, neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. Examples of the alicyclic diol include 1,2 cyclohexanedimethanol, 1,3 cyclohexanedimethanol, , 4 cyclohexanedimethanol.

In addition, a trihydric or higher polyhydric alcohol can be used for the purpose of increasing branch points in the polyester resin (A). Examples of the trihydric or higher polyhydric alcohol include pentaerythritol, dipentaerythritol, and tripenta. Examples include erythritol, glycerin, trimethylolpropane, trimethylolethane, 1,3,6-hexanetriol, adamantanetriol and the like.
The content ratio of the trihydric or higher polyhydric alcohol is preferably 10 mol% or less, particularly preferably 0.1 to 5 mol%, based on the entire polyol component (A2), and the content ratio is too large. And the production of the polyester resin (A) tends to be difficult.

  As a blending ratio of the polyvalent carboxylic acid component (A1) and the polyol component (A2), the polyol component (A2) is preferably 1 to 2 equivalents, particularly preferably, per equivalent of the polyvalent carboxylic acid component (A1). Is 1.1 to 1.7 equivalents. If the content ratio of the polyol component (A2) is too low, the acid value tends to be high and it becomes difficult to increase the molecular weight, and if it is too high, the yield tends to decrease.

  The polyester resin (A) used in the present invention is produced by arbitrarily selecting the polyvalent carboxylic acid component (A1) and the polyol component (A2) and subjecting them to a polycondensation reaction by a known method in the presence of a catalyst. Is done.

  In the polycondensation reaction, an esterification reaction is first performed and then a condensation reaction is performed.

  In such esterification reaction, a catalyst is used. Specifically, catalysts such as titanium-based catalysts such as tetraisopropyl titanate and tetrabutyl titanate, antimony-based catalysts such as antimony trioxide, germanium-based catalysts such as germanium dioxide, and the like Examples of the catalyst include zinc acetate, manganese acetate, and dibutyltin oxide, and one or more of these are used. Among these, antimony trioxide, tetrabutyl titanate, and germanium dioxide are preferable from the viewpoint of high catalytic activity and hue.

  The amount of the catalyst is preferably 1 to 10,000 ppm, particularly preferably 10 to 5,000 ppm, and still more preferably 20 to 3,000 ppm with respect to all copolymer components. If the blending amount is too small, the polymerization reaction tends not to proceed sufficiently, and if it is too large, there is no advantage such as shortening the reaction time and a side reaction tends to occur.

  About the reaction temperature at the time of esterification reaction, 160-260 degreeC is preferable, Especially preferably, it is 180-250 degreeC, More preferably, it is 200-250 degreeC. 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 should just be under normal pressure normally.

After the esterification reaction is performed, a condensation reaction is performed.
As the reaction conditions for the polycondensation reaction, a catalyst similar to that used in the above esterification reaction is further blended in the same amount, and the reaction temperature is preferably 220 to 280 ° C. (particularly preferably 230 to 270 ° C.) It is preferable to gradually reduce the pressure of the reaction system and finally react 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 number average molecular weight of the polyester resin (A) used in the present invention is preferably 5,000 or more, particularly preferably 10,000 to 100,000, and more preferably 15,000 to 80,000.
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 and initial adhesion is reduced. It tends to be difficult to exert a sufficient adhesive force with a pressure of about a finger pressure.

In addition, said number average molecular weight is a number average molecular weight by standard polystyrene molecular weight conversion, a column: TSKgel SuperMultipore HZ-M (exclusion limit molecular weight: 2) in a high performance liquid chromatography (the Tosoh company make, "HLC-8320GPC"). × 10 ⁶ , Theoretical plate number: 16,000 plate / line, Filler material: Styrene-divinylbenzene copolymer, Filler particle size: 4 μm) are used.

The acid value of the polyester resin (A) is preferably 5 mgKOH / g or less, particularly preferably 1 mgKOH / g or less, more preferably 0.5 mgKOH / g or less, particularly preferably 0.2 mgKOH / g or less. is there. If the acid value is too high, corrosion will occur when the metal oxide thin film layer is formed on one side of the pressure-sensitive adhesive layer made of the present polyester-based pressure-sensitive adhesive, and the conductivity of the metal oxide film tends to decrease. There is.
The acid value of the polyester resin is determined by neutralization titration based on JIS K0070.

<Hydrolysis inhibitor (B)>
The polyester-based pressure-sensitive adhesive composition of the present invention contains a hydrolysis inhibitor (B) together with the polyester-based resin (A). By containing the hydrolysis inhibitor (B), a desired composition can be obtained. A pressure-sensitive adhesive layer having characteristics can be obtained, and an improvement in durability under high temperature and high humidity can be expected.

  The hydrolysis inhibitor (B) is not particularly limited, and a conventionally known one can be used. For example, the hydrolysis inhibitor (B) reacts with the carboxylic acid end group of the polyester resin (A) to bind. Examples thereof include compounds having 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 carboxyl group end groups.

  As the carbodiimide group-containing compound, a known polycarbodiimide having one or more carbodiimide groups (—N═C═N—) in the molecule may be used, but the durability under higher temperature and higher humidity is improved. In terms of this point, a compound containing two or more carbodiimide groups in the molecule is preferable, particularly a compound containing three or more, more preferably five or more, and particularly preferably seven or more. In addition, when 30 or more are contained, the molecular structure becomes excessively large, which tends to be undesirable. 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-03, V-05, V -07 and V-09 are preferable in terms of excellent compatibility with organic solvents.

  As said epoxy 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, glycidyl t-Bu-benzoate, glycidyl p-toluate, glycidyl cyclohexane carboxylic acid, glycidyl pelargonate, glycyl stearate, 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 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, dodecane Examples include diionic diglycidyl ester, octadecanedicarboxylic acid diglycidyl ester, trimellitic acid triglycidyl ester, and pyromellitic acid tetraglycidyl ester. 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 the reaction of bisphenol such as methane and epichlorohydrin can be mentioned. It can be used in combination with the above.

  The oxazoline compound is preferably a bisoxazoline compound. Specifically, for example, 2,2'-bis (2-oxazoline), 2,2'-bis (4-methyl-2-oxazoline), 2,2'-bis (4,4-dimethyl-2-) Oxazoline), 2,2′-bis (4-ethyl-2-oxazoline), 2,2′-bis (4,4′-diethyl-2-oxazoline), 2,2′-bis (4-propyl-2) -Oxazoline), 2,2'-bis (4-butyl-2-oxazoline), 2,2'-bis (4-hexyl-2-oxazoline), 2,2'-bis (4-phenyl-2-oxazoline) ), 2,2′-bis (4-cyclohexyl-2-oxazoline), 2,2′-bis (4-benzyl-2-oxazoline), 2,2′-p-phenylenebis (2-oxazoline), 2 , 2'-m-phenylenebis (2-oxazoline), , 2′-o-phenylenebis (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'-ethylene Bis (2-oxazoline), 2,2′-tetramethylene bis (2-oxazoline), 2,2′-hexamethylene bis (2-oxazoline), 2,2′-octamethylene bis (2-oxazoline), 2 , 2′-Decamethylenebis (2-oxazoline), 2,2′-ethylenebis (4-methyl-2-oxazoline), 2,2′-tetramethylenebis (4,4-dimethyl-2-oxa Phosphorus), 2,2′-9,9′-diphenoxyethanebis (2-oxazoline), 2,2′-cyclohexylenebis (2-oxazoline), 2,2′-diphenylenebis (2-oxazoline) Among them, 2,2′-bis (2-oxazoline) is most preferable from the viewpoint of reactivity with polyester. Furthermore, the bisoxazoline compounds mentioned above can be used alone or in combination of two or more as long as the object of the present invention is achieved.

  As these hydrolysis inhibitors (B), those with lower volatility are preferable, and for this reason, it is preferable to use those having a high molecular weight.

  The blending amount of the hydrolysis inhibitor (B) 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 (A). More preferably, it is 0.2 to 3 parts by weight. If the amount is too large, turbidity tends to occur due to poor compatibility with the polyester resin (A), and if it is too small, sufficient durability tends to be difficult to obtain.

Further, the blending amount of the hydrolysis inhibitor (B) is preferably optimized according to the acid value of the polyester resin (A), and the polyester resin ( The molar ratio ((b) / (a)) of the sum (a) of the acid value of A) and the sum (b) of the functional group amount of the hydrolysis inhibitor (B) in the polyester resin composition is 0. .5 ≦ (b) / (a), preferably 1 ≦ (b) / (a) ≦ 1,000, more preferably 1.5 ≦ (b) / (a) ≦ 100. is there.
When the content ratio of (b) with respect to (a) is too high, the compatibility with the polyester-based resin (A) tends to decrease, or the adhesive strength, cohesive strength, and durability performance tend to decrease. When the content ratio of b) is low, the heat-and-moisture resistance tends to decrease.

<Polyester adhesive composition>
The polyester-based pressure-sensitive adhesive composition of the present invention contains the polyester-based resin (A) and the hydrolysis inhibitor (B). Usually, the polyester-based resin (A) is coagulated by crosslinking with a crosslinking agent. Excellent performance as an adhesive.
Examples of such a crosslinking agent include compounds having a functional group that reacts with a hydroxyl group and / or a carboxyl group contained in a polyester resin, such as a polyisocyanate compound and a polyepoxy compound. Among these, a polyisocyanate compound is particularly preferable from the viewpoint that both initial tackiness, mechanical strength, and heat resistance can be balanced.

  Examples of such polyisocyanate compounds include polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, and hydrogenated xylylene diisocyanate. And tolylene diisocyanate adducts of trimethylolpropane, and isocyanate adducts such as hexamethylene diisocyanate adduct and isophorone diisocyanate adduct. In addition, the said polyisocyanate compound can also use what the isocyanate part was blocked with phenol, lactam, etc. These crosslinking agents may be used individually by 1 type, and may be used in mixture of 2 or more types.

The amount of such a crosslinking agent can be appropriately selected depending on the molecular weight of the polyester resin (A) and the purpose of use, but is usually 1 equivalent of the hydroxyl group and / or carboxyl group contained in the polyester resin (A). The reactive group contained in the cross-linking agent preferably contains the cross-linking agent in a ratio of 0.2 to 10 equivalents, particularly preferably 0.5 to 5 equivalents, and more preferably 0.5 to 3 equivalents. .
If the number of equivalents of reactive groups contained in such a cross-linking agent is too small, the cohesive force tends to decrease, and sufficient heat resistance tends to be not obtained, and if it is too large, the flexibility decreases and the initial adhesiveness decreases, There is a tendency that sufficient adhesive force cannot be exhibited at a pressure of about a finger pressure.

The polyester-based pressure-sensitive adhesive of the present invention preferably contains substantially no acidic group. Specifically, the acid value is preferably 10 mgKOH / g or less, particularly preferably 1 mgKOH / g or less, Preferably it is 0.1 mgKOH / g or less.
In addition, the acid value of the said polyester-type adhesive can be calculated | required by the method similar to the acid value of the said polyester-type resin (A).

In the polyester-based pressure-sensitive adhesive composition of the present invention, additives such as conventionally known softening agents, ultraviolet absorbers, stabilizers, antistatic agents, tackifiers, and the like, as long as the effects of the present invention are not impaired. Alternatively, organic fillers, powders such as metal powders and pigments, and additives such as particles can be blended.
In addition, about the said tackifier, it is preferable not to contain substantially from the point of durability and transparency.

  The polyester-based pressure-sensitive adhesive composition of the present invention is preferably used as a pressure-sensitive adhesive for optical members used for laminating optical members, and a pressure-sensitive adhesive layer made of such a polyester-based pressure-sensitive adhesive composition is laminated on the optical member. Thus, the optical member with the pressure-sensitive adhesive layer can be obtained.

  Such optical members include ITO electrode films and 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, when the optical member is a transparent electrode film, the effect of the present invention can be remarkably exhibited and high adhesive force is 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.

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

Further, the polyester-based pressure-sensitive adhesive of the present invention can be used as a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer made of the pressure-sensitive adhesive of the present invention on one side or both sides of a support substrate, and in particular, an optical material used for bonding optical members. It is suitable as an adhesive sheet for members.
Moreover, it is also preferable to set it as the base material-less double-sided adhesive sheet which does not have a support base material at the point which is excellent in transparency and has high adhesive force with respect to the thickness which comprises.
In the present invention, “sheet” is described as meaning including “film” and “tape”.
An adhesive sheet can be produced as follows, for example.

<Adhesive sheet>
As a method for producing such an adhesive sheet, it can be produced according to a known general method for producing an adhesive sheet. For example, on the base sheet, the polyester resin (A), the hydrolysis inhibitor (B), preferably Furthermore, the pressure-sensitive adhesive sheet of the present invention having a pressure-sensitive adhesive layer comprising the polyester-based pressure-sensitive adhesive of the present invention on the substrate is obtained by coating, drying, and curing the polyester pressure-sensitive adhesive composition containing the crosslinking agent as necessary. .
Moreover, a base material-less double-sided pressure-sensitive adhesive sheet can be produced by forming a pressure-sensitive adhesive layer on the release sheet and bonding the release sheet to the opposite pressure-sensitive adhesive layer surface.
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; synthetic resin sheet such as polyimide, aluminum, copper, iron metal foil, paper such as fine paper, glassine paper, glass fiber, natural fiber, synthetic fiber Examples thereof include woven fabrics and non-woven fabrics. These base material sheets can be used as a single layer body or a multilayer body in which two or more kinds are laminated.
Among these, a base sheet made of polyethylene phthalate or polyimide is particularly preferable, polyethylene terephthalate is particularly preferable in terms of excellent adhesion to the pressure-sensitive adhesive, and further polyethylene terephthalate having a metal thin film layer. It is preferable in that the adhesion between the material and the adhesive is excellent, the substrate can be stably maintained without corroding the metal thin film layer, and the effect of the polyester-based pressure-sensitive adhesive of the present invention can be exhibited remarkably.
In the present invention, the ITO electrode film has a pressure-sensitive adhesive layer on the PET side of the film formed as a thin film on the PET base material, and the PET base material and the polycarbonate film are laminated via the pressure-sensitive adhesive layer, Furthermore, it is most preferable to set it as the optical laminated body by which an acrylic film is laminated | stacked (layer structure: ITO electrode film / PET base material / adhesive layer / PC system 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. As the release sheet, it is preferable to use a silicon-based 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, and a spray coater.

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

  Moreover, as drying conditions, the drying temperature is preferably 60 to 140 ° C., particularly preferably 80 to 120 ° C., and the drying time is preferably 1 to 30 minutes, particularly preferably 2 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 further 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 is a value calculated | required by deducting 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 using Mitutoyo "ID-C112B". It is.

  About the gel fraction of the adhesive layer of the said adhesive sheet, it is preferable that it is 50% or more from the point of durable performance and adhesive force, Especially preferably, it is 60 to 100%, More preferably, it is 70 to 85%. 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, polyethylene terephthalate film or the like) as a base material is wrapped with a 200-mesh SUS wire mesh, and 23 in toluene. The weight percentage of the insoluble pressure-sensitive adhesive component immersed in the wire mesh at 24 ° C. for 24 hours is defined as the gel fraction. However, the weight of the substrate is subtracted.

  Further, the pressure-sensitive adhesive sheet may be protected 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 applied to the surface of the base material opposite to the pressure-sensitive adhesive layer by using a release treatment surface. It is also possible to protect.

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.
Moreover, regarding the measurement of the number average molecular weight and the glass transition temperature of the polyester resin in the following examples, the measurement was performed according to the above-described method. The acid value of the polyester resin was measured by neutralization titration based on JIS K0070 by dissolving 0.5 g of the polyester resin in a mixed solvent of 7/3 (weight ratio) (toluene / methanol).

<Production of polyester resin (A)>
[Production Example 1: Production of polyester resin (A-1)]
In a reaction vessel equipped with a thermometer, a stirrer, a rectifying column, a nitrogen introduction tube and a vacuum apparatus, 9.6 parts (0.2 mol) of isophthalic acid and 46.8 parts of sebacic acid as a polyvalent carboxylic acid component (A1) (0.8 mol), 27.1 parts (0.9 mol) of neopentyl glycol as polyol component (A2), 13 parts (0.5 mol) of 1,4-butanediol, 3 parts of 1,6-hexanediol (0.09 mol) and 0.5 parts (0.01 mol) of trimethylolpropane, and 0.01 part of tetrabutyl titanate as a catalyst were added, the temperature was gradually raised to 250 ° C., and esterification was performed over 4 hours. Reaction was performed. Thereafter, the internal temperature was raised to 260 ° C., 0.01 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 (A-1). The number average molecular weight of the obtained polyester resin (A-1) was 25,000, the glass transition temperature was −50 ° C., and the acid value was 0.4 (mgKOH / g).

[Production Example 2: Production of polyester resin (A-2)]
In a reaction vessel equipped with a thermometer, a stirrer, a rectifying column, a nitrogen introduction tube and a vacuum apparatus, 9.2 parts (0.2 mol) of isophthalic acid and 22.3 parts of sebacic acid as a polyvalent carboxylic acid component (A1) (0.4 mol), 20.7 parts (0.4 mol) of azelaic acid, 8.9 parts (0.52 mol) of ethylene glycol as polyol component (A2), 38.9 parts (0.98) of cyclohexanedimethanol Mol), 0.02 part of germanium dioxide was charged as a catalyst, 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 270 ° C., the pressure was reduced to 1.33 hPa, and a polycondensation reaction was performed over 3 hours to produce a polyester resin (A-2). The number average molecular weight of the obtained polyester resin (A-2) was 30,000, the glass transition temperature was −25 ° C., and the acid value was 0.7 (mgKOH / g).

[Comparative Production Example 1: Production of Polyester Resin (A′-1)]
In a reaction vessel equipped with a thermometer, a stirrer, a rectifying column, a nitrogen introduction tube and a vacuum apparatus, 21 parts (0.33 mol) of terephthalic acid and 16.6 parts of isophthalic acid (0) as the polyvalent carboxylic acid component (A1) .26 mol), 23 parts (0.41 mol) of adipic acid, 18.4 parts (0.78 mol) of ethylene glycol as the polyol component (A2), 21 parts (0.53 mol) of neopentyl glycol, and tetra as the catalyst. 0.02 part of butyl titanate was charged, the temperature was gradually raised to an internal temperature of 250 ° C., and an esterification reaction was performed over 4 hours. Thereafter, the internal temperature was raised to 260 ° C., 0.02 part of tetrabutyl titanate was charged as a catalyst, the pressure was reduced to 1.33 hPa, and a polycondensation reaction was performed over 3 hours to produce a polyester resin (A′-1). The number average molecular weight of the obtained polyester resin (A′-1) was 20,000, and the glass transition temperature was 11 ° C. The acid value was 0.6 (mgKOH / g).

<Hydrolysis inhibitor (B)>
The following were prepared as the hydrolysis inhibitor (B).
(B-1) Carbodiimide group-containing hydrolysis inhibitor (manufactured by Nisshinbo Chemical Co., Ltd .; trade name “Carbodilite V-07”)
(B-2) Carbodiimide group-containing hydrolysis inhibitor (Nisshinbo Chemical Co., Ltd .; trade name “Carbodilite V-05”)

Example 1
The polyester-based resin (A-1) obtained above is diluted with ethyl acetate to a solid content concentration of 50%, and 100 parts (solid content) of this polyester-based resin (A-1) solution is subjected to a hydrolysis inhibitor ( B-1) 2 parts, and 6 parts of trimethylolpropane / tolylene diisocyanate adduct (manufactured by Nippon Polyurethane Industry Co., Ltd .; product name “Coronate L55E”) as a cross-linking agent were mixed, stirred and mixed to obtain a polyester. A system adhesive was obtained.

(Example 2)
In Example 1, a polyester pressure-sensitive adhesive was obtained in the same manner as in Example 1 except that 2 parts of the hydrolysis inhibitor (B-1) was changed to 2.5 parts of the hydrolysis inhibitor (B-2). It was.

(Example 3)
In Example 1, the polyester resin (A-1) was changed to the polyester resin (A-2) and the hydrolysis inhibitor (B-1) was changed to 1 part. A system adhesive was obtained.

(Comparative Example 1)
In Example 1, the polyester adhesive was obtained like Example 1 except having changed the polyester-type resin (A-1) into the polyester-type resin (A'-1).

(Comparative Example 2)
In Example 1, a polyester-based pressure-sensitive adhesive was obtained in the same manner as in Example 1 except that no hydrolysis inhibitor was blended.

<Manufacture of PET film with adhesive layer>
The polyester-based pressure-sensitive adhesives obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were each coated on a polyethylene terephthalate (PET) film having a thickness of 38 μm using an applicator, dried at 100 ° C. for 3 minutes, An adhesive sheet having a thickness of 25 μm was obtained. Next, the obtained pressure-sensitive adhesive layer surface was covered with a release-treated PET film (release film) and subjected to an aging treatment at 40 ° C. for 5 days to obtain a PET film with a release film-attached pressure-sensitive adhesive layer.

  Using the PET film with the pressure-sensitive adhesive layer with the release film, the initial adhesive strength, durability, and transparency were evaluated. The results are summarized in Table 1.

[Initial adhesive strength]
After the PET film with the adhesive layer with the release film obtained above is cut into 25 × 200 mm in an environment of 23 ° C. and 50% RH, the release film is peeled off, and the adhesive layer side is placed on a SUS plate with a 2 kg roller. After being reciprocated and pressure-applied and left for 10 seconds in the same atmosphere, 180 degree peel strength (N / s) at a peel rate of 300 mm / min using an autograph (“Autograph AGS-H 500N” manufactured by Shimadzu Corporation) 25 mm) was measured and evaluated according to the following criteria.
(Evaluation criteria)
○: 1N / 25mm or more ×: Less than 1N / 25mm

[durability]
As shown below, the adhesive strength during normal time (adhesive strength before wet heat test) and the adhesive strength after long-term exposure to high temperature and high humidity (adhesive strength after wet heat test) are measured and (adhesive strength after wet heat test / before wet heat test) A value of (adhesive strength) × 100 (%) (change in adhesive strength) was calculated, and durability was evaluated according to the following criteria.
(Evaluation criteria)
○ ・ ・ ・ 50% or more × ・ ・ ・ less than 50%

<Adhesive strength before wet heat test>
After the PET film with the adhesive layer with the release film obtained above is cut into 25 × 200 mm in an environment of 23 ° C. and 50% RH, the release film is peeled off, and the adhesive layer side is placed on a SUS plate with a 2 kg roller. Were reciprocated and pressure-applied, and allowed to stand in the same atmosphere for 30 minutes, then using an autograph (“Autograph AGS-H 500N” manufactured by Shimadzu Corporation) at a peeling rate of 300 mm / min and a 180 ° peel rate (N / 25 mm).

<Adhesive strength after wet heat test>
After the PET film with the adhesive layer with the release film obtained above is cut into 25 × 200 mm in an environment of 23 ° C. and 50% RH, the release film is peeled off, and the adhesive layer side is placed on a SUS plate with a 2 kg roller. Were reciprocated and pressure-applied, and left in an environment of temperature: 85 ° C. and relative humidity of 85% for 500 hours. After returning to room temperature and allowing to stand for 24 hours, using an autograph (“Autograph GS-H 500N” manufactured by Shimadzu Corporation) in an environment where the temperature is 23 ° C. and the relative humidity is 50%, the peeling speed is 300 mm / min. Degree peel strength (/ 25 mm) was measured.

[transparency]
The PET film with the pressure-sensitive adhesive layer was left in an 80 ° C. environment for 5 days. Thereafter, the temperature was returned to room temperature, the yellowness b * was measured with a color difference meter, and evaluated according to the following criteria.
(Evaluation criteria)
○ ・ ・ ・ less than 1 × ・ ・ ・ 1 or more

From the results of Examples 1 to 3, the pressure-sensitive adhesive layer of the polyester-based pressure-sensitive adhesive obtained using the polyester-based resin having a glass transition temperature within the desired range and the hydrolysis inhibitor is exposed to high temperature and high humidity. Even in this case, it can be seen that the adhesive has excellent physical properties and transparency.
On the other hand, the polyester-based pressure-sensitive adhesive of Comparative Example 1 using a polyester-based resin having a glass transition temperature higher than the range specified in claim 1 of the present invention has a low initial pressure-sensitive adhesive force, and a sufficient pressure-sensitive adhesive strength can be obtained at a pressure of about a finger pressure. You can see that it is not.
In addition, the polyester-based pressure-sensitive adhesive of Comparative Example 2 that does not contain a hydrolysis inhibitor is exposed to high temperature and high humidity, and then the pressure-sensitive adhesive is hydrolyzed to reduce the cohesive force. It can be seen that is not obtained.

Example 4
The polyester resin (A-1) obtained above is diluted with ethyl acetate to a solid content concentration of 50% by weight, and a hydrolysis inhibitor is added to 100 parts (solid content) of this polyester resin (A-1) solution. (B-1) 1 part and 3 parts of trimethylolpropane / tolylene diisocyanate adduct (manufactured by Nippon Polyurethane Industry Co., Ltd .; product name “Coronate L55E”) as a crosslinking agent are mixed, stirred and mixed. As a result, a polyester-based pressure-sensitive adhesive was obtained.

(Example 5)
In Example 4, a polyester-based pressure-sensitive adhesive was obtained in the same manner as in Example 4 except that the polyester-based resin (A-1) was changed to the polyester-based resin (A-2).

(Comparative Example 3)
In Example 4, a polyester-based pressure-sensitive adhesive was obtained in the same manner as in Example 4 except that the hydrolysis inhibitor (B-1) was not blended.

(Comparative Example 4)
In Example 5, a polyester-based pressure-sensitive adhesive was obtained in the same manner as in Example 4 except that the hydrolysis inhibitor (B-1) was not blended.

<Manufacture of substrate-less double-sided PSA sheet>
The polyester-based pressure-sensitive adhesives obtained in Examples 4 and 5 and Comparative Examples 3 and 4 were each applied onto a polyethylene terephthalate (PET) film (release film) having a thickness of 38 μm and subjected to a release treatment using an applicator. And dried at 100 ° C. for 3 minutes to obtain a PSA sheet having a PSA layer thickness of 50 μm. Next, the surface of the obtained pressure-sensitive adhesive composition layer was covered with a release-treated PET film, and an aging treatment was performed at 40 ° C. for 5 days to obtain a substrate-less double-sided pressure-sensitive adhesive sheet with a double-sided release film.

One release film of the obtained substrate-less double-sided pressure-sensitive adhesive sheet with a double-sided release film was peeled off, transferred to a polyethylene terephthalate (PET) film with an easy-adhesion layer having a thickness of 100 μm, and a PET with a pressure-sensitive adhesive layer with a release film A film was obtained.
Blister resistance was evaluated using the obtained PET film with an adhesive layer with a release film. The results are shown in Table 2.

[Blister resistance]
The PET film with the adhesive layer with the release film obtained above was cut into a width of 50 mm and a length of 40 mm, the release film was peeled off, and the pressure-sensitive adhesive layer side was placed on a polycarbonate plate at 23 ° C. and a relative humidity of 50%. 2kg rubber roller in two reciprocating atmospheres, and autoclaved at 0.5MPa x 50 ° C for 20 minutes, then left under conditions of temperature: 85 ° C and relative humidity of 85% for 3 hours. After that, the generation of bubbles was confirmed visually. The evaluation criteria are as follows.
(Evaluation criteria)
○… There were no bubbles exceeding φ0.2 mm. Δ… Bubbles exceeding φ0.2 mm were generated in less than 1/3 of the entire pasting surface. × ... Bubbles exceeding φ0.2 mm were generated in one third or more of the entire pasting surface. Or the adhesive layer was dissolved and eluted

From the results of Examples 4 and 5, it can be seen that the polyester-based pressure-sensitive adhesive of the present invention is extremely excellent in blister resistance without foaming even when exposed to high temperature and high humidity conditions.
On the other hand, although the polyester-type resin whose glass transition temperature is in a desired range was used, Comparative Examples 3 and 4 using a polyester-based adhesive not containing a hydrolysis inhibitor were exposed to high-temperature and high-humidity conditions. It can be seen that foaming occurs and the adhesive layer is further eluted, and the blister resistance is not satisfied.

The polyester-based pressure-sensitive adhesive of the present invention can be used as a pressure-sensitive adhesive for electronic parts, a pressure-sensitive adhesive for bonding optical members, a pressure-sensitive adhesive for soft vinyl chloride, and the like.
In particular, the polyester-based pressure-sensitive adhesive of the present invention is excellent in both adhesive physical properties (adhesive strength) and transparency under conditions where durability (high temperature and high humidity) is required, and also extremely resistant to blistering. Since it is excellent, it can be suitably used for bonding optical members, and in particular, it can be suitably used for bonding optical members made of plastic materials.

Claims (11)

  A polyester-based pressure-sensitive adhesive containing a polyester-based resin (A) and a hydrolysis inhibitor (B), wherein the polyester-based resin (A) has a glass transition temperature of −10 ° C. or lower. Agent composition.   The polyester-based pressure-sensitive adhesive composition according to claim 1, wherein the polyvalent carboxylic acid component (A1), which is a constituent material of the polyester-based resin (A), contains isophthalic acid.   The polyester-based pressure-sensitive adhesive composition according to claim 1 or 2, wherein the hydrolysis inhibitor (B) is a carbodiimide-based hydrolysis inhibitor.   Content of a hydrolysis inhibitor (B) is 0.01-10 weight part with respect to 100 weight part of polyester-type resin (A), The polyester-type adhesion | attachment in any one of Claims 1-3 characterized by the above-mentioned. Agent composition.   Furthermore, a crosslinking agent (C) is contained, The polyester-type adhesive composition in any one of Claims 1-4 characterized by the above-mentioned.   The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 5, which contains substantially no tackifier.   A polyester-based pressure-sensitive adhesive composition, wherein the polyester-based pressure-sensitive adhesive composition according to claim 1 is crosslinked with a crosslinking agent (C).   It has an adhesive layer which consists of a polyester-type adhesive of Claim 7, The adhesive sheet for optical members characterized by the above-mentioned.   A substrate-less double-sided pressure-sensitive adhesive sheet for optical members, comprising release sheets on both sides of the pressure-sensitive adhesive layer comprising the polyester-based pressure-sensitive adhesive according to claim 7.   An optical member with a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer comprising the polyester-based pressure-sensitive adhesive according to claim 7 and an optical member are laminated.   An optical laminate comprising a metal oxide thin film layer on at least one surface of a pressure-sensitive adhesive layer comprising the polyester-based pressure-sensitive adhesive according to claim 7.