JP2019073685A - Polyester adhesive composition, polyester adhesive, adhesive sheet and optical member with adhesive layer - Google Patents

Abstract

To provide a polyester adhesive composition having excellent adhesiveness to a polyolefin base material, and also excellent haze and solution transparency, a polyester adhesive, an adhesive sheet and an optical member with an adhesive layer.SOLUTION: A polyester adhesive composition contains a polyester resin (A) having a structural unit derived from a hydrogenated polybutadiene structure-containing compound (a3). The content of the structural unit derived from the hydrogenated polybutadiene structure-containing compound (a3) is 0.01-35 wt.% relative to the polyester resin (A).SELECTED DRAWING: None

Description

  The present invention relates to a polyester-based pressure-sensitive adhesive composition, a polyester-based pressure-sensitive adhesive, a pressure-sensitive adhesive sheet, and an optical member with a pressure-sensitive adhesive layer, more specifically, a polyester having excellent adhesion to a polyolefin substrate and also excellent haze and solution transparency The present invention relates to a pressure-sensitive adhesive composition, a polyester-based pressure-sensitive adhesive, a pressure-sensitive adhesive sheet, and an optical member with a pressure-sensitive adhesive layer.

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

  In recent years, display devices such as liquid crystal displays (LCDs) and input devices used in combination with the above display devices such as touch panels have been widely used, and in the manufacture of these devices, optical devices are used. A transparent pressure-sensitive adhesive sheet is used to bond optical members such as films and substrates.

  For example, a film with a pressure-sensitive adhesive using a polyester-based pressure-sensitive adhesive composition having a hydrogenated polybutadiene skeleton as such a pressure-sensitive adhesive sheet, adhesion in which the cohesion and cohesivity at the time of sticking to a metal plate are achieved. A sheet has been proposed (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 3-167284

However, although the above-mentioned patent document 1 can obtain the adhesiveness to a metal plate, it is not considered at all about the adhesiveness to a polyolefin substrate which is generally poor in adhesiveness, and also in the case of being used as a pressure-sensitive adhesive sheet. It was not satisfactory in the point of solution transparency as a haze or an adhesive composition.
Furthermore, in recent years, applications using a polyolefin substrate as an adherend, for example, applications such as automobile interiors / exterior materials and building materials are increasing, and the demand for adhesiveness to the polyolefin substrate is extremely high.

  Therefore, in the present invention, under such background, a polyester-based pressure-sensitive adhesive composition excellent in adhesion to a polyolefin substrate and further excellent in haze and solution transparency, polyester-based pressure-sensitive adhesive, pressure-sensitive adhesive sheet and pressure-sensitive adhesive layer attached It aims at providing an optical member.

  However, as a result of intensive studies conducted by the present inventor under these circumstances, it is possible to obtain a polyolefin substrate by incorporating a hydrogenated polybutadiene structure in a polyester resin and making the content relatively smaller than in the prior art. The present invention has been found to be a polyester-based pressure-sensitive adhesive composition which is excellent in adhesion as well as transparency.

  That is, the gist of the present invention is a polyester-based pressure-sensitive adhesive composition containing a polyester resin (A) having a structural unit derived from a hydrogenated polybutadiene structure-containing compound (a3), which comprises a hydrogenated polybutadiene structure-containing compound (a3) The present invention relates to a polyester-based pressure-sensitive adhesive composition in which the content of the structural unit derived from the polyester resin (A) is 0.01 to 35% by weight.

  The present invention also provides a polyester-based pressure-sensitive adhesive, in which the polyester-based pressure-sensitive adhesive composition is crosslinked, as a second aspect, and a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer containing such a polyester-based pressure-sensitive adhesive as a third aspect. I assume. Furthermore, a pressure-sensitive adhesive layer-containing optical member having a polyester-based pressure-sensitive adhesive according to the second aspect and a pressure-sensitive adhesive layer-carrying optical member having an optical member are referred to as a fourth aspect.

  Generally, in order to improve the adhesion of the polyester-based pressure-sensitive adhesive composition to a substrate, it is conceivable to add a tackifier to control the cohesion of the pressure-sensitive adhesive layer and the interfacial adhesion.

  Furthermore, when applied to a polyolefin substrate generally having poor adhesion, it is usually considered to increase the content even more. However, sufficient compatibility can not be obtained between the tackifier and the polyester resin, and it may be difficult to balance adhesion characteristics due to cloudiness of the pressure-sensitive adhesive layer or reduction in low-temperature tackiness, and adhesion reliability may be deteriorated.

  In addition, it is also conceivable to include a hydrogenated polybutadiene structure to improve the adhesion of the polyester-based pressure-sensitive adhesive composition to the substrate, and the improvement effect is shown by increasing the content as in the tackifier. Although it is a wax, sufficient compatibility can not be obtained, too, and it becomes difficult to balance the adhesive properties due to the clouding of the pressure-sensitive adhesive layer and the decrease in cohesion.

  In the present invention, the tackiness agent is not used, and the content of the hydrogenated polybutadiene structure of the polyester-based resin is surprisingly relatively small, whereby the adhesiveness to the polyolefin substrate is excellent and the haze and the solution are excellent. It has been found that the transparency is also excellent.

  The polyester-based pressure-sensitive adhesive composition of the present invention is a polyester-based pressure-sensitive adhesive composition containing a polyester-based resin (A) having a structural unit derived from a hydrogenated polybutadiene structure-containing compound (a3), which contains a hydrogenated polybutadiene structure Since the content of the structural unit derived from the compound (a3) is 0.01 to 35% by weight with respect to the polyester resin (A), the adhesion to the polyolefin substrate is excellent, and the haze and the solution transparency are further enhanced. Also excellent.

Hereinafter, although the configuration of the present invention will be described in detail, these are merely examples of the preferred embodiments.
In the present invention, the term "carboxylic acids" includes, in addition to carboxylic acids, carboxylic acid salts such as carboxylic acid salts, carboxylic acid anhydrides, carboxylic acid halides and carboxylic acid esters.

  The polyester-based pressure-sensitive adhesive composition of the present invention contains a polyester-based resin (A) having a structural unit derived from a hydrogenated polybutadiene structure-containing compound (a3), and a structural unit derived from a hydrogenated polybutadiene structure-containing compound (a3) It is characterized in that the content is 0.01 to 35% by weight with respect to the polyester resin (A).

  That is, in the polyester-based resin (A) used in the polyester-based pressure-sensitive adhesive composition of the present invention, the content of structural units derived from the hydrogenated polybutadiene structure-containing compound (a3) is in the polyester-based resin (A) It is obtained by polymerizing and preparing a hydrogenated polybutadiene structure-containing compound (a3) so as to be 0.01 to 35% by weight.

And the polyester-based pressure-sensitive adhesive composition of the present invention comprises the above-mentioned polyester-based resin (A) as an essential component, and from the group consisting of a hydrolysis inhibitor (B), a urethanization catalyst (C), and a crosslinking agent (D). It is preferable to contain at least one selected, and it is more preferable to contain any of the components (B) to (D).
The components constituting such a polyester-based pressure-sensitive adhesive composition of the present invention will be sequentially described below.

<Polyester resin (A)>
The polyester-based resin (A) is usually obtained by copolymerizing a copolymerization component containing a polyvalent carboxylic acid (a1) and a polyol (a2) as a constituent raw material, and the polyester-based resin (A) is As a resin composition, it comes to have a structural unit derived from polyvalent carboxylic acids (a1) and a structural unit derived from polyol (a2).

  The polyester-based resin (A) used in the present invention can be obtained by copolymerizing a hydrogenated polybutadiene structure-containing compound (a3). The hydrogenated polybutadiene structure-containing compound (a3) is a polyester-based resin (A). It is preferable to be contained as at least one of polyhydric carboxylic acids (a1) and polyols (a2) which are constituent materials of (a).

[Polyvalent carboxylic acids (a1)]
Examples of the polyvalent carboxylic acids (a1) used as a constituent raw material of the polyester resin (A) include dihydric carboxylic acids and trivalent or higher polyvalent carboxylic acids, and the polyester resin (A) is stable. Divalent carboxylic acids are preferably used from the viewpoint of being obtained.

Examples of the above divalent carboxylic acids include malonic acids, dimethylmalonic acids, succinic acids, glutaric acids, adipic acids, trimethyladipic acids, pimelic acids, 2,2-dimethyl glutaric acids, azelaic acids, sebacic acids, fumaric acids, Aliphatic dicarboxylic acids such as maleic acids, itaconic acids, thiodipropionic acids, diglycolic acids, 1,9-nonane dicarboxylic acids, etc .;
Phthalic acids, terephthalic acids, isophthalic acids, benzylmalonic acids, diphenic acids, 4,4'-oxydibenzoic acids, further 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, 2,7-naphthalenedicarboxylic acids, etc. Aromatic dicarboxylic acids such as naphthalene dicarboxylic acids;
Alicyclic acids such as 1,3-cyclopentane dicarboxylic acids, 1,2-cyclohexane dicarboxylic acids, 1,3-cyclopentane dicarboxylic acids, 1,4-cyclohexane dicarboxylic acids, 2,5-norbornane dicarboxylic acids, adamantane dicarboxylic acids, etc. Family dicarboxylic acids;
Etc.

Further, examples of the trivalent or higher carboxylic acids include trimellitic acid, pyromellitic acid, adamantane tricarboxylic acid, trimesic acid and the like.
These polyvalent carboxylic acids (a1) can be used alone or in combination of two or more.

  Further, among the above polyvalent carboxylic acids (a1), from the viewpoint of lowering the crystallinity of the polyester resin (A), it is preferable to include an asymmetric aromatic polyvalent carboxylic acid (a1-1). Examples of the aromatic polyvalent carboxylic acids (a1-1) include phthalic acids, isophthalic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, 2,7-naphthalenedicarboxylic acids and the like. Among them, isophthalic acids are particularly preferably used in view of reactivity.

  The content of such asymmetric aromatic polyvalent carboxylic acids (a1-1) is preferably 1 to 90 mol%, particularly preferably 2 to 80 mol, based on the whole polyvalent carboxylic acids (a1). %, More preferably 3 to 60 mol%, more preferably 4 to 50 mol%, particularly preferably 5 to 40 mol%. If the content is too small, the resin tends to crystallize and sufficient adhesion performance can not be obtained, and if too large, the compatibility and the initial adhesion (tack) tend to be reduced.

  Furthermore, among the above polyvalent carboxylic acids (a1), an aliphatic polyvalent carboxylic acid (a1-2) having an odd number of carbon atoms is included from the viewpoint of lowering the crystallinity of the polyester resin (A) from another viewpoint. Examples of aliphatic polyvalent carboxylic acids (a1-2) having an odd number of carbon atoms include malonic acids, glutaric acids, pimelic acids, azelaic acids, 1,9-nonane dicarboxylic acids, etc. However, azelaic acids are particularly preferably used.

The content of the aliphatic polyvalent carboxylic acids (a1-2) having an odd number of carbon atoms is preferably 5 to 100 mol% with respect to the whole polyvalent carboxylic acids (a1). In particular, when importance is given to solution transparency, the content is preferably 5 to 100 mol%, particularly preferably 10 to 100 mol%, and still more preferably 20 to 100 mol based on the whole polyvalent carboxylic acid (a1). %, Particularly preferably 30 to 100 mol%. If the content is too small, the resin tends to crystallize and a sufficient adhesion performance can not be obtained.
When importance is attached to adhesion to a polyolefin substrate, it is preferably 5 to 100 mol%, particularly preferably 10 to 95% mol%, further preferably to the whole polybasic carboxylic acid (a1). Is 20 to 90 mol%, particularly preferably 30 to 80 mol%. If the content is too small, the resin tends to crystallize and a sufficient adhesion performance can not be obtained. When the amount is too large, the adhesion to the polyolefin substrate tends to be lowered.

  In the present invention, it is also preferable to use an asymmetric aromatic polyvalent carboxylic acid (a1-1) and an aliphatic polyvalent carboxylic acid in combination as the polyvalent carboxylic acids (a1) from the viewpoint of adhesive physical properties. As the content ratio (molar ratio) of the asymmetric aromatic polyvalent carboxylic acids (a1-1) and the aliphatic polyvalent carboxylic acids, the asymmetric aromatic polyvalent carboxylic acids (a1-1) / aliphatic polyvalent carboxylic acids = 0.1 / 99.9 to 70/30, preferably 0.2 / 99.8 to 60/40, more preferably 0.5 / 99.5 to 50/50, particularly preferably Preferably it is 1/99 to 40/60, more preferably 3/97 to 30/70.

  In order to increase the branching point in the polyester resin (A), trivalent or higher polyvalent carboxylic acids can also be used, and among them, trimellitic acids are used in that gelation is relatively unlikely to occur. Is preferred.

  The content of such trivalent or higher polyvalent carboxylic acids is preferably at most 10 mol%, particularly preferably at most 10 mol%, based on the whole of the polyvalent carboxylic acids (a1) in that the cohesion of the adhesive can be enhanced. When the content is too large, gelation tends to easily occur during the production of the polyester resin (A).

[Polyol (a2)]
As a polyol (a2) used as a constituent raw material of polyester-based resin (A), there exist a dihydric alcohol and a trivalent or more polyol.

Examples of the above dihydric alcohols include 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 Aliphatic diols such as 4-trimethyl-1,6-hexanediol;
1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, spiroglycol, tricyclodecanedimethanol, 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 These include aromatic diols such as ethylene oxide adducts and propylene oxide adducts, and the like.
Furthermore, fatty acid esters derived from castor oil, oleic acid, dimer diols derived from erucic acid and the like, glycerol monostearate and the like can be mentioned.
Further, examples of the trivalent or higher polyols include pentaerythritol, dipentaerythritol, tripentaerythritol, glycerin, trimethylolpropane, trimethylolethane, 1,3,6-hexanetriol, adamantantriol and the like.
These polyols (a2) described above can be used alone or in combination of two or more.

Among the polyols (a2), it is preferable to contain a branched structure-containing polyol (a2-1) from the viewpoint of increasing the branching point and breaking the crystallinity. As a branched structure-containing polyol (a2-1), for example, neopentyl glycol, 2-methyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol, 2,2-diethyl- 1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2- Methyl 2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,3,5-trimethyl-1,3-pentanediol, 2-methyl-1,6-hexanediol etc. are mentioned. Be Among them, neopentyl glycol is particularly preferable. Furthermore, the branched structure-containing polyol preferably has a molecular weight of 1,000 or less.
In addition, as a branch structure containing polyol (a2-1), the below-mentioned hydrogenated polybutadiene polyol (a3-1) is remove | excluded.

  The content of the branched structure-containing polyol (a2-1) is preferably 5 to 99 mol%, particularly 10 to 98 mol%, and further 30 to 97 mol% with respect to the whole polyol (a2). Is preferred. If the content is too small, the resin tends to crystallize and it is difficult to obtain sufficient adhesion performance. If the content is too large, the reaction time tends to be long in the production of the polyester resin (A).

  On the other hand, among the polyols (a2), it is preferable to contain a linear polyol (a2-2) from the viewpoint of reactivity, and more preferably a linear polyol having 2 to 40 carbon atoms. As this linear polyol (a2-2), for example, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol And aliphatic glycols such as 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, and the like. Among these, 1,4-butanediol is particularly preferable.

  The content of the linear polyol (a2-2) is preferably 1 to 100% by mole, more preferably 3 to 99.999% by mole, particularly preferably 5 to 99.99% with respect to the whole polyol (a2). It is preferable that it is mol%, further 7 to 99.9 mol%, especially 10 to 99.5 mol%. If the content is too small, stable resin formation tends to be difficult to obtain.

  In addition, trivalent or higher polyols may be used to increase the branching point in the polyester resin (A), and examples of trivalent or higher polyols include pentaerythritol, dipentaerythritol, tripentaerythritol, glycerin, and the like. Examples include trimethylolpropane, trimethylolethane, 1,3,6-hexanetriol, adamantantriol and the like.

  The content of such a trivalent or higher polyol is preferably 20 mol% or less, more preferably 0.1 to 10 mol%, particularly preferably 0 to 10 mol%, based on the whole polyol (a2). 5 to 5 mol% is preferable, and when the content is too large, production of the polyester resin (A) tends to be difficult.

  The compounding ratio of the polyvalent carboxylic acids (a1) and the polyol (a2) is preferably 1 to 3 equivalents of the polyol (a2) per one equivalent of the polyvalent carboxylic acids (a1), particularly preferably 1.1. ~ 2 equivalents. When the blending ratio of the polyol (a2) is too small, the acid value tends to be high and the high molecular weight formation tends to be difficult, and when too large, the yield tends to be reduced.

[Hydrogenated polybutadiene structure-containing compound (a3)]
As described above, the polyester resin (A) used in the present invention has a structural unit derived from the hydrogenated polybutadiene structure-containing compound (a3). A hydrogenated polybutadiene structure-containing compound (a3) can be appropriately blended as a constituent material of such a polyester resin (A), but from the viewpoint of achieving the object of the present invention, polyvalent carboxylic acids (a1) It is preferable to contain a hydrogenated polybutadiene structure-containing compound (a3) as at least one of the polyol (a2) and the polyol (a2).

  As the hydrogenated polybutadiene structure-containing compound (a3) contained in the polyvalent carboxylic acids (a1), for example, 1,2-polybutadiene dicarboxylic acids, 1,4-polybutadiene dicarboxylic acids, 1,2-polychloropredicarboxylic acids, Linear polyvalent polyvalent carboxylic acids in which polybutadiene type polyvalent carboxylic acids such as 1,4-polychloroprene carboxylic acids or the like or polyvalent polyvalent carboxylic acids thereof are saturated with hydrogen or halogen or the like, chlorinated polyethyl carboxylic acids, chlorinated polyethylene There are polyvalent carboxylic acids and saturated hydrocarbon type polyvalent carboxylic acids having a branch. Furthermore, polyvalent carboxylic acids obtained by copolymerizing polybutadiene-based polyvalent carboxylic acids with olefin compounds such as styrene, ethylene, vinyl acetate, acrylic acid esters and the like, hydrogenated polyvalent carboxylic acids, and the like can also be used. Among them, particularly preferred are hydrocarbon-based polybutadiene polyvalent carboxylic acids having a high degree of saturation, having a number average molecular weight of 500 to 6,000 and an average functionality of carboxyl groups of 1.5 to 3.

  The content of the hydrogenated polybutadiene structure-containing compound (a3) is preferably 0.001 to 5 mol%, more preferably 0.005 to 4 with respect to the total copolymerization component of the polyester resin (A). It is preferable that it is mol%, particularly 0.01 to 3 mol%, especially 0.02 to 2 mol%. If the content is too low, the adhesion to the polyolefin substrate tends to decrease, and if too high, the compatibility tends to decrease.

  Moreover, as a constituent raw material of polyester-based resin (A), it is more preferable to contain a hydrogenated polybutadiene structure-containing compound (a3) as the polyol (a2), and among them, a hydrogenated polybutadiene structure-containing compound is particularly preferable. (A3) is the hydrogenated polybutadiene polyol (a3-1) in the polyol (a2).

  Examples of the hydrogenated polybutadiene polyol (a3-1) include polybutadiene-based polyols such as 1,2-polybutadiene polyol, 1,4-polybutadiene polyol, 1,2-polychloroprene polyol, 1,4-polychloroprene polyol and the like, or These include linear polyethylene polyols in which the double bonds of these polybutadiene-based polyols are saturated with hydrogen or halogen, chlorinated polyethylene polyols, branched saturated hydrocarbon-based polyols, and the like. Furthermore, a polyol obtained by copolymerizing an olefin compound such as styrene, ethylene, vinyl acetate or acrylic ester with a polybutadiene-based polyol, a hydrogenated polyol thereof or the like can also be used. Among them, particularly preferred is a hydrocarbon-based polybutadiene polyol having a high degree of saturation, having a number average molecular weight of 500 to 6,000 and an average functionality of hydroxyl groups of 1.5 to 3.

  In addition, as the hydrogenated polybutadiene polyol (a3-1), one having a larger proportion of the 1,2 bonding site in the 1,2 bonding site and 1,4 bonding site in the structure of the hydrogenated polybutadiene polyol is an olefin base It is preferable at the point which is excellent in the adhesiveness to. The proportion of 1,2 bond sites in the hydrogenated polybutadiene polyol (a3-1) is preferably 25 to 100%, particularly preferably 50 to 100%, and particularly preferably 75 to 100%. Is preferred.

  The content of the hydrogenated polybutadiene polyol (a3-1) is preferably 0.001 to 5 mol%, and more preferably 0.005 to 4 with respect to the total copolymerization component of the polyester resin (A). It is preferable that it is mol%, particularly 0.01 to 3 mol%, especially 0.02 to 2 mol%. If the content is too low, the adhesion to the polyolefin substrate tends to decrease, and if too high, the compatibility tends to decrease.

  The polyester-based resin (A) used in the present invention is produced by arbitrarily selecting the above-mentioned polyvalent carboxylic acids (a1) and polyols (a2) and subjecting them to a polycondensation reaction in the presence of a catalyst by a known method. However, it is necessary in the structure thereof to have a predetermined amount of structural units derived from the hydrogenated polybutadiene structure-containing compound (a3).

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

  In the esterification reaction, a catalyst is usually used. Specifically, for example, a titanium-based catalyst such as tetraisopropyl titanate or tetrabutyl titanate, an antimony-based catalyst such as antimony trioxide, or a germanium-based catalyst such as germanium dioxide And catalysts such as zinc acetate, manganese acetate, dibutyltin oxide and the like, and one or more of these may be used. Among these, antimony trioxide, tetrabutyl titanate, germanium dioxide and zinc acetate are preferable in terms of the balance of the height of the catalytic activity and the hue.

  The compounding 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 the copolymerization components. If the compounding amount is too small, the polymerization reaction tends to be difficult to proceed sufficiently, and if it is too large, there is no advantage such as shortening of the reaction time, and side reactions tend to occur easily.

  The reaction temperature during the esterification reaction is preferably 200 to 300 ° C., particularly preferably 210 to 280 ° C., and still more preferably 220 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 normal pressure.

After the esterification reaction is performed, a polycondensation reaction is performed.
As the reaction conditions for the polycondensation reaction, the same amount of catalyst as that used in the esterification reaction described above 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 system and to make the reaction finally 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.

  Thus, the polyester resin (A) used in the present invention is obtained.

  The polyester resin (A) contains a structural unit derived from the hydrogenated polybutadiene structure-containing compound (a3), and the content of the structural unit derived from the hydrogenated polybutadiene structure-containing compound (a3) in the polyester resin (A) Is preferably 0.01 to 35% by weight, preferably 0.1 to 30% by weight, particularly preferably 0.2 to 20% by weight, more preferably 0.3 to 10% by weight, more preferably 0.4 % To 5% by weight, particularly preferably 0.5 to 3% by weight.

  The structural unit derived from the above hydrogenated polybutadiene structure-containing compound (a3) in the polyester resin (A) is at least one of a structural unit derived from a polyvalent carboxylic acid (a1) and a structural unit derived from a polyol (a2) It is preferable from the viewpoint of the adhesiveness to the polyolefin substrate that it is preferably contained as a structural unit derived from the polyol (a2).

  Furthermore, when the structural unit derived from the hydrogenated polybutadiene polyol (a3-1) is contained as a structural unit derived from the polyol (a2), the structural unit derived from the hydrogenated polybutadiene polyol (a3-1) is a polyol (a2) It is preferable from the viewpoint of compatibility that it is contained in the structural unit derived from) from 0.001 to 10 mol%, more preferably 0.01 to 8 mol%, particularly preferably 0.03 to 5 mol%, particularly preferably Is 0.04 to 3 mol%, and 0.05 to 0.5 mol%.

  The polyester resin (A) usually has a structural unit derived from the polyvalent carboxylic acid (a1) and a structural unit derived from the polyol (a2), but the asymmetric aromatic polyvalent carboxylic acid (a1-1) When the structural unit derived from is contained as a structural unit derived from polyvalent carboxylic acids (a1), the structural unit derived from asymmetrical aromatic polyvalent carboxylic acids (a1-1) is derived from polyvalent carboxylic acids (a1) The structural unit is preferably 1 to 90 mol%, particularly preferably 2 to 80 mol%, more preferably 3 to 60 mol%, more preferably 4 to 50 mol%, particularly preferably 5 to 40 mol%. It is mol%.

  When a structural unit derived from an aliphatic polyvalent carboxylic acid (a1-2) having an odd number of carbon atoms is contained as a structural unit derived from a polyvalent carboxylic acid (a1), an aliphatic polyvalent carboxylic acid having an odd number of carbon atoms The structural unit derived from the acids (a1-2) is preferably 5 to 100 mol%, more preferably 10 to 100 mol%, still more preferably 20 to 100 mol% in the structural unit derived from the polyvalent carboxylic acids (a1). It is 100 mol%, particularly preferably 30 to 100 mol%.

  On the other hand, when the structural unit derived from the branched structure-containing polyol (a2-1) is contained as a structural unit derived from the polyol (a2), the structural unit derived from the branched structure-containing polyol (a2-1) is a polyol (a2) It is preferable to contain 5 to 99 mol% in the structural unit derived from the above from the viewpoint of destroying the crystallinity, particularly 10 to 98 mol%, and further preferably 30 to 97 mol%.

  When the structural unit derived from the linear polyol (a2-2) is contained as a structural unit derived from the polyol (a2), the structural unit derived from the linear polyol (a2-2) is derived from the polyol (a2) It is preferable from the viewpoint of stable resin formation that the content of 3-95 mol% in structural units is more preferably 5 to 90 mol%, particularly preferably 10 to 80 mol%, especially 15 to 60 mol%. is there.

  Here, the structural unit ratio (composition ratio) derived from each component of the polyester resin (A) can be determined, for example, by NMR.

  The glass transition temperature of the polyester resin (A) is preferably −80 to 20 ° C., particularly preferably −75 to 15 ° C., further preferably −65 to 10 ° C., particularly preferably from the viewpoint of adhesion physical properties. Is -60 to -30 ° C. If the glass transition temperature is too high, the flexibility is lost, the initial tackiness is reduced, the adhesive strength is less likely to be exhibited at a pressure of about finger pressure, the workability tends to be reduced, and the cohesion is reduced if it is too low. As a result, the pressure-sensitive adhesive sheet tends to be deformed and lose its appearance.

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

  The polyester-based resin (A) is preferably not crystallized from the viewpoint of storage stability, but even in the case of crystallization, it is preferable that the crystallization energy of the polyester-based resin (A) be as low as possible, usually 35 J / g The following is preferably 20 J / g or less, particularly preferably 10 J / g or less, particularly preferably 5 J / g or less.

  The acid value of the above-mentioned polysether resin (A) is preferably 10 mg KOH / g or less, particularly preferably 3 mg KOH / g or less, and more preferably 1 mg KOH / g or less. If the acid value is too high, it tends to corrode when a layer of metal or the like is laminated on one side of the pressure-sensitive adhesive layer. For example, when the metal oxide thin film layer is formed, corrosion occurs and the conductivity of the metal oxide thin film tends to decrease.

  Here, the acid value of the polyester resin (A) is determined by neutralization titration based on JIS K 0070.

  Further, the weight average molecular weight of the polyester resin (A) is preferably 8,000 to 200,000, particularly 10,000 to 180,000, and further 20, from the viewpoint of the cohesion of the adhesive. It is preferable that it is 000-150,000. When the weight-average molecular weight is too small, sufficient cohesion as a pressure-sensitive adhesive can not be obtained, and heat resistance and mechanical strength tend to decrease, and when it is too large, it becomes easy to gel at the time of production of polyester resin (A). And resins tend to be difficult to obtain.

In addition, the weight average molecular weight of this invention is a weight average molecular weight by standard polystyrene molecular weight conversion, and high-performance liquid chromatograph (Tosoh Corp. make, "HLC-8320GPC"), column: TSKgel SuperMultipore HZ-M (exclusion limit molecular weight: 2 × 10 ⁶ , theoretical plate number: 16,000 plates / bar, filler material: styrene-divinylbenzene copolymer, filler particle diameter: 4 μm) The same method can be used for the number average molecular weight.

<Hydrolysis inhibitor (B)>
The polyester-based pressure-sensitive adhesive composition of the present invention (hereinafter sometimes abbreviated as "pressure-sensitive adhesive composition") preferably contains a hydrolysis inhibitor (B) together with the above-mentioned polyester-based resin (A). Such a hydrolysis inhibitor (B) is contained to secure long-term durability.

  As the above-mentioned hydrolysis inhibitor (B), conventionally known ones can be used, and examples thereof include a compound which is reacted with and bonded to the carboxylic acid terminal group of the above-mentioned polyester resin (A). Examples thereof include compounds containing functional groups such as carbodiimide group, epoxy group and oxazoline group. Among these, a carbodiimide group-containing compound is preferable in that the effect of eliminating the catalytic activity of a proton derived from a carboxyl group end group is high. These can be used alone or in combination of two or more.

  As the carbodiimide group-containing compound, generally, a known polycarbodiimide having one or more carbodiimide groups (-N = C = N-) in the molecule may be used, but the durability under high temperature and high humidity is further improved. In terms of point, it is preferable to use a compound containing two or more carbodiimide groups in the molecule, that is, a polyvalent carbodiimide type compound, in particular a compound containing three or more, further five or more, especially seven or more. Is preferred. The number of carbodiimide groups contained in the molecule is usually 50 or less, and when the number of carbodiimide groups is too large, the molecular structure tends to be too 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.

  Furthermore, as for the said high molecular weight polycarbodiimide, that by which the terminal isocyanate group is sealed by the sealing agent is preferable at the point of storage stability. The blocking agent includes a compound having an active hydrogen that reacts with an isocyanate group, or a compound having an isocyanate group. For example, monoalcohols having one substituent selected from a carboxyl group, an amino group and an isocyanate group, monocarboxylic acids, monoamines and monoisocyanates can be mentioned.

  As such a high molecular weight polycarbodiimide, what carried out the decarboxylation condensation reaction of the following diisocyanate is mentioned.

  As such diisocyanate, for example, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethoxy-4,4'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'- Diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1-methoxyphenyl-2,4-diisocyanate, isophorone diisocyanate 4, 4'-dicyclohexylmethane diisocyanate, tetramethyl xylylene diisocyanate and the like can be mentioned, and these can be used alone or in combination of two or more. Such high molecular weight polycarbodiimides may be synthesized or commercially available products.

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

  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, benzoic acid glycidyl ester, t-Bu-benzoic acid glycidyl ester, p-toluic acid glycidyl ester, cyclohexanecarboxylic acid glycidyl ester, pelargonic acid glycidyl ester, stearic acid glycidyl ester, lauric acid Glycidyl ester, palmitic acid glycidyl ester, behenic acid glycidyl ester, versatic acid glycidyl ester, oleic acid glycidyl ester, linoleic acid glycidyl ester, linoleic acid glycidyl ester, behenolic acid glycidyl ester, stearic acid glycidyl ester, terephthalic acid diglycidyl ester, Isophthalic acid diglycidyl ester, phthalic acid diglycidyl ester, naphthalene dicarboxylic acid digry Dilster ester, methylterephthalic 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 thereof include dodecanedioic acid diglycidyl ester, octadecanedicarboxylic acid diglycidyl ester, trimellitic acid triglycidyl ester, pyromellitic acid tetraglycidyl ester and the like, and these can be used alone or in combination of two or more.

  Specific examples of the glycidyl ether compound include, for example, phenyl glycidyl ether, o-phenyl glycidyl ether, 1,4-bis (β, γ-epoxypropoxy) butane, 1,6-bis (β, γ- Epoxypropoxy) hexane, 1,4-bis (β, γ-epoxypropoxy) benzene, 1- (β, γ-epoxypropoxy) -2-ethoxyethane, 1- (β, γ-epoxypropoxy) -2- Benzyloxyethane, 2,2-bis- [р- (β, γ-epoxypropoxy) phenyl] propane and 2,2-bis- (4-hydroxyphenyl) propane and 2,2-bis- (4-hydroxyphenyl) B.) Bisglycidyl polyethers obtained by the reaction of bisphenols such as methane with epichlorohydrin, etc., which may be used alone or in combination of two or more It can be used in combination.

  As said oxazoline group containing compound, a bis oxazoline compound etc. are 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-phenylene bis (2-oxazoline), 2 , 2'-m-phenylene bis (2-oxazoline), , 2′-o-phenylene bis (2-oxazoline), 2,2′-p-phenylene bis (4-methyl-2-oxazoline), 2,2′-p-phenylene bis (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′-decamethylene bis (2-oxazoline), 2,2′-ethylene bis (4-methyl-2-oxazoline), 2,2′-tetramethylene bis (4,4-dimethyl-2-oxax) Phosphorus), 2,2′-9,9′-diphenoxyethane bis (2-oxazoline), 2,2′-cyclohexylene bis (2-oxazoline), 2,2′-diphenylene bis (2-oxazoline) And the like, and among these, 2,2′-bis (2-oxazoline) is most preferable from the viewpoint of the reactivity with the polyester. Moreover, these can be used alone or in combination of two or more.

As these hydrolysis inhibitors (B), those having low volatility are preferable, and therefore, those having a high number average molecular weight are preferable, and usually 300 to 10,000, preferably 1,000 to 5,000. Use the
Moreover, as a hydrolysis inhibitor (B), it is more preferable to use what has a high weight average molecular weight from a viewpoint of hydrolysis resistance. The weight average molecular weight of the hydrolysis inhibitor (B) is preferably 500 or more, more preferably 2,000 or more, and still more preferably 3,000 or more. The upper limit of the weight average molecular weight is usually 50,000.
When the weight average molecular weight of the hydrolysis inhibitor (B) is too small, the hydrolysis resistance tends to decrease. When the weight average molecular weight is too large, the compatibility with the polyester resin tends to decrease.

  Among the hydrolysis inhibitors (B), it is preferable to use a carbodiimide group-containing compound, in which case the carbodiimide equivalent is preferably 50 to 10,000, particularly 100 to 1,000, and more preferably 150. It is preferable that it is 500. In addition, a carbodiimide equivalent shows chemical formula weight per carbodiimide group.

  The content of the hydrolysis inhibitor (B) is preferably 0.01 to 10 parts by weight, particularly preferably 0.1 to 5 parts by weight, per 100 parts by weight of the polyester resin (A). More preferably, it is 0.2 to 3 parts by weight. If the content is too large, turbidity tends to occur due to poor compatibility with the polyester resin (A), and if too small, sufficient durability tends to be difficult to be obtained.

The content of the hydrolysis inhibitor (B) is preferably optimized according to the acid value of the polyester resin (A), and the polyester resin (A) in the pressure-sensitive adhesive composition is preferably used. The molar ratio ((b) / (a)) of the total of the number of moles of the functional groups of the hydrolysis inhibitor (B) in the pressure-sensitive adhesive composition to the total number of moles of acidic functional groups of (a) It is preferable that 0.5 ≦ (b) / (a), particularly preferably 1 ≦ (b) / (a) ≦ 1,000, and still more preferably 1.5 ≦ (b) / (a) ≦ It is 100.
If the molar ratio of (b) to (a) is too low, the moisture and heat resistance performance tends to deteriorate. When the molar ratio of (b) to (a) is too high, the compatibility with the polyester resin (A) tends to decrease, and the adhesive strength, cohesion, and durability tend to decrease.

<Urethanization catalyst (C)>
The pressure-sensitive adhesive composition of the present invention contains the above-mentioned polyester resin (A), preferably contains the above-mentioned hydrolysis inhibitor (B), but in view of the reaction rate, the urethane-forming catalyst (C) is used. It is more preferable to contain.

  As a urethanization catalyst (C), an organic metal type compound, a tertiary amine compound, etc. are mentioned, for example. These can be used alone or in combination of two or more.

Examples of the organic metal compounds include zirconium compounds, iron compounds, tin compounds, titanium compounds, lead compounds, cobalt compounds, zinc compounds and the like.
Examples of the zirconium-based compound include zirconium naphthenate and zirconium acetylacetonate.
Examples of the iron-based compound include iron acetylacetonate, iron 2-ethylhexanoate and the like.
Examples of tin-based compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dilaurate and the like.
Examples of the titanium-based compound include dibutyl titanium dichloride, tetrabutyl titanate, butoxy titanium trichloride and the like.
Examples of lead-based compounds include lead oleate, lead 2-ethylhexanoate, lead benzoate, lead naphthenate and the like.
Examples of cobalt-based compounds include cobalt 2-ethylhexanoate, cobalt benzoate and the like.
Examples of zinc compounds include zinc naphthenate and zinc 2-ethylhexanoate.

  Moreover, as said tertiary amine compound, a triethylamine, a triethylenediamine, 1,8- diaza bicyclo- (5,4,0)-undecen-7 etc. are mentioned, for example.

  Among these urethanization catalysts (C), organic metal compounds are preferable in view of reaction rate and pot life of the pressure-sensitive adhesive layer, and zirconium compounds are particularly preferable. Furthermore, the urethanization catalyst (C) is preferably used in combination with acetylacetone as a catalyst inhibitor. A catalyst system containing acetylacetone is preferable in terms of suppressing the catalytic action at low temperatures and prolonging the pot life.

<Crosslinking agent (D)>
The pressure-sensitive adhesive composition of the present invention contains the above-mentioned polyester resin (A), preferably contains a hydrolysis inhibitor (B), but usually further contains a crosslinking agent (D) Preferably, by containing the crosslinking agent (D), the polyester resin (A) is crosslinked with the crosslinking agent (D) to be excellent in cohesion, and the performance as an adhesive can be improved.

  Examples of the crosslinking agent (D) include polyisocyanate compounds, polyepoxy compounds, and compounds having a functional group that reacts with at least one of a hydroxyl group and a carboxyl group contained in the polyester resin (A). Among these, it is preferable to use a polyisocyanate compound in particular from the viewpoint of achieving both initial tackiness, mechanical strength and heat resistance in a well-balanced manner.

  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 And polyisocyanates such as 5-naphthalenediisocyanate and triphenylmethane triisocyanate; adducts of the above-mentioned polyisocyanates with polyol compounds such as trimethylolpropane; buret bodies of these polyisocyanate compounds; A nurate body etc. are mentioned. In addition, the said polyisocyanate compound can be used even if what the isocyanate part was blocked by a phenol, a lactam, etc. One of these crosslinking agents (D) may be used alone, or two or more thereof may be mixed and used.

The content of the crosslinking agent (D) can be appropriately selected depending on the molecular weight of the polyester resin (A) and the purpose of use, but usually, one equivalent of at least one of a hydroxyl group and a carboxyl group contained in the polyester resin (A) Preferably, the reactive group contained in the crosslinking agent (D) contains the crosslinking agent (D) in a proportion of 0.2 to 10 equivalents, particularly preferably 0.5 to 5 equivalents, further Preferably, it is 0.5 to 3 equivalents.
If the number of equivalents of the reactive group contained in the crosslinking agent (D) is too small, the cohesion tends to be reduced, and if it is too large, the flexibility tends to be reduced.

  In the reaction of the polyester resin (A) with the crosslinking agent (D), an organic solvent having no functional group that reacts with the components (A) and (D), for example, esters such as ethyl acetate and 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 can be used alone or in combination of two or more.

  In the pressure-sensitive adhesive composition of the present invention, in addition to the polyester resin (A), the hydrolysis inhibitor (B), the urethanization catalyst (C) and the crosslinking agent (D) described above, the effects of the present invention can be obtained. Additives such as antioxidants (E) such as hindered phenols, softeners, UV absorbers, stabilizers, antistatic agents, tackifiers, etc., and other inorganic or organic fillers, as long as they are not impaired Additives such as metal powder, powder such as pigment, and particles may be blended. These can be used alone or in combination of two or more.

  Further, the polyester-based pressure-sensitive adhesive (hereinafter sometimes abbreviated as "pressure-sensitive adhesive") according to the present invention is one comprising the above-mentioned pressure-sensitive adhesive composition, that is, one obtained by curing the pressure-sensitive adhesive composition.

The pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one side or both sides of a supporting substrate, or a substrate-less pressure-sensitive adhesive sheet, and in particular, an adhesive for optical members used for laminating optical members It is suitable as a sheet.
In the present invention, "sheet" is described as meaning including "film" and "tape".

<Adhesive sheet>
The pressure-sensitive adhesive sheet can be produced, for example, as follows.
The pressure-sensitive adhesive sheet can be produced according to a known method for producing a general pressure-sensitive adhesive sheet. For example, the above-mentioned pressure-sensitive adhesive composition is coated on a substrate, dried, and the pressure-sensitive adhesive composition on the opposite side A release sheet (or release film) is bonded to the surface of the product layer, and if necessary, curing is carried out to obtain the pressure-sensitive adhesive sheet of the present invention having a pressure-sensitive adhesive layer comprising a pressure-sensitive adhesive composition on a substrate.

  The pressure-sensitive adhesive sheet of the present invention can also be obtained by coating the above-mentioned pressure-sensitive adhesive composition on a release sheet, drying it, bonding a substrate to the pressure-sensitive adhesive composition layer surface on the opposite side, and curing as necessary. Be

  Moreover, a substrate-less double-sided pressure-sensitive adhesive sheet can be produced by forming a pressure-sensitive adhesive layer on a release sheet and bonding the release sheet to the pressure-sensitive adhesive layer surface on the opposite side.

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

  Examples of the substrate include polyester resins such as polyethylene naphthalate, polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate / isophthalate copolymer; polyolefin resins such as polyethylene, polypropylene and polymethylpentene; polyvinyl fluoride, Polyfluoroethylene resins such as polyvinylidene fluoride and polyfluoroethylene; Polyamides such as nylon 6, nylon 6,6 and the like; polyvinyl chloride, polyvinyl chloride / vinyl acetate copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl Alcohol copolymers, vinyl polymers such as polyvinyl alcohol and vinylon; Cellulose-based resins such as cellulose triacetate and cellophane; polymethyl methacrylate, polyethyl methacrylate, polyethyl acrylate Acrylic resin such as butyl polyacrylate; polystyrene; polycarbonate; polyarylate; polyimide; sheet composed of at least one synthetic resin selected from the group consisting of cycloolefin polymer etc .; metal foil of aluminum, copper, iron; Examples thereof include paper such as paper and glassine paper; woven and non-woven fabrics made of glass fibers, natural fibers, synthetic fibers and the like. These substrates can be used as a single layer body or a multilayer body in which two or more kinds are laminated.

  Among them, particularly preferred is a substrate made of polyethylene terephthalate or polyimide, and particularly preferred is polyethylene terephthalate from the viewpoint of excellent adhesion to a pressure-sensitive adhesive, and further, polyethylene terephthalate having a metal thin film layer. It is preferable in that it is excellent in the adhesive force with the pressure-sensitive adhesive, can stably keep the base without corroding the metal thin film layer, and can remarkably exhibit the effect as the pressure-sensitive adhesive of the present invention.

  In the present invention, the pressure-sensitive adhesive layer is provided on the PET side of the film in which the ITO electrode film is formed as a thin film on a polyethylene terephthalate (PET) substrate, and the PET substrate and polycarbonate (PC It is also preferable to make an optical laminate in which a base film is laminated and an acrylic film is further laminated (layer structure: ITO electrode film / PET base material / pressure-sensitive adhesive layer / PC base film / acrylic film).

 Moreover, a foam base material can be used as the said base material, for example, the foam sheet which consists of foams of synthetic resins, such as a polyurethane foam, a polyethylene foam, a polyacrylate foam. By using the foam sheet, it is excellent in flexibility, and the followability to the adherend and the adhesive strength are improved. Among these, polyacrylate foams are preferable from the viewpoint of being excellent in the balance between the followability to the adherend and the adhesive strength.

[Filling material]
In addition, the foam sheet may contain a filler. By including the filler in the foam sheet, it is possible to increase the shear strength. By this, the resistance (peeling strength) with respect to peeling off an adhesive sheet from a to-be-adhered body can be improved. Moreover, by using the filler, it is possible to suppress the excessive deformation of the foam sheet and suitably adjust the balance between the flexibility and the cohesion as the whole pressure-sensitive adhesive sheet.

  As the filler, various particulate substances can be used. As a constituent material of such particulate matter, for example, metals such as copper, nickel, aluminum, chromium, iron and stainless steel; metal oxides such as alumina and zirconia; carbides such as silicon carbide, boron carbide and nitrogen carbide; aluminum nitride , Nitrides such as silicon nitride and boron nitride; inorganic materials such as calcium carbide, calcium carbonate, aluminum hydroxide, glass, and silica; polystyrene, acrylic resin (for example, polymethyl methacrylate), phenol resin, benzoguanamine resin, urea resin, silicone Examples thereof include resins, nylon, polyester, polyurethane, polyethylene, polypropylene, polyamide, polyimide, silicone, polymers such as vinylidene chloride and the like. Alternatively, natural raw material particles such as volcanic shirasu and sand may be used. These can be used singly or in combination of two or more.

Further, the outer shape and the particle shape of the particulate matter are not particularly limited.
Examples of the outer shape of the particulate matter include a spherical shape, a flake shape, and an irregular shape. The particle structure of the above-mentioned particulate matter includes, for example, a dense structure, a porous structure, a hollow structure and the like.
Among them, the foam sheet preferably contains a particulate material having a hollow structure (hereinafter, also referred to as “hollow particles”) as the filler, and more preferably includes hollow particles made of an inorganic material. Examples of such hollow particles include glass balloons such as hollow glass balloons; hollow balloons made of metal compounds such as hollow alumina balloons; and hollow balloons made of porcelain such as hollow ceramic balloons.

  As a hollow glass balloon, for example, trade name "Glass micro balloon" manufactured by Fuji Silysia Chemical, "Fuji balloon H-40", "Fuji balloon H-35", trade name "Celstar Z-20 manufactured by Tokai Industry Co., Ltd." “CELLSTAR Z-27”, “CELLSTAR CZ-31T”, “CELLSTAR Z-36”, “CELLSTAR Z-39”, “CELLSTAR Z-39”, “CELLSTAR T-36”, “CELLSTAR PZ-6000” , Trade name "Cylux Fineballoon" manufactured by Fineballoon Co., "Q-CEL (trademark) 5020" manufactured by Potters Barrotini, "Q-CEL (trademark) 7014", "Sphericel (trademark) 110P8 "," Sphericel (TM) 25P45 "," Sphericel (TM) 34P30 "," Sp Commercial products such as Hericel (trademark) 60P18 ", trade names" Super Balloon BA-15 "," Super Balloon 732 C "manufactured by Showa Kagaku Kogyo Co., Ltd. can be used.

The average particle size of the hollow particles is not particularly limited. The average particle diameter of the hollow particles is, for example, usually 1 to 500 μm, preferably 5 to 400 μm, more preferably 10 to 300 μm, still more preferably 10 to 200 μm, and particularly preferably 10 to 150 μm.
The average particle size of the hollow particles is usually 50% or less of the thickness of the foam sheet, preferably 30% or less, and more preferably 10% or less.

The specific gravity of the hollow particles is not particularly limited, but in consideration of uniform dispersibility, mechanical strength, etc., for example, usually 0.1 to 1.8 g / cm ³ , preferably 0.1 to 1.5 g / cm ³ , more preferably 0.1 to 0.5 g / cm ^3, particularly preferably 0.2-0.5 g / cm ^3.
The use amount of the hollow particles is not particularly limited, and may be, for example, 1 to 70% by volume of the volume of the whole foam sheet, preferably 5 to 50% by volume, and particularly preferably 10 It is preferable to set it as -40 volume%.

[Bubbles]
The foam sheet may have direct cells, as well as cells having the above-mentioned filler. By including air bubbles in the foam sheet, the cushioning properties of the pressure-sensitive adhesive sheet can be improved, and the flexibility can be enhanced. When the flexibility of the pressure-sensitive adhesive sheet is high, the irregularities and the steps on the surface of the adherend can be easily absorbed by the deformation of the pressure-sensitive adhesive sheet, so that the pressure-sensitive adhesive surface can be more closely adhered to the surface of the adherend. Good adhesion of the adhesive surface to the adherend surface can advantageously contribute to the improvement of the peel strength to the low polarity surface and other various surfaces.

 Moreover, the improvement of the softness | flexibility of an adhesive sheet can also contribute to the reduction of the repulsive force of an adhesive sheet. Thus, when the pressure-sensitive adhesive sheet is attached along the surface of an adherend having a curved surface or a step, or when the adherend to which the pressure-sensitive adhesive sheet is attached is deformed, etc. It is possible to effectively suppress the event of peeling off (lifting) from the surface of the adherend.

  The foam sheet may include both fillers (eg, hollow particles) and cells as described above. An adhesive sheet containing such a foam sheet is preferable because it tends to be excellent in the balance between the flexibility and the cohesion.

  The cells contained in the foam sheet may be closed cells or open cells, or they may be mixed. From the viewpoint of cushioning properties, a foam sheet having a large number of closed cells is more preferable.

  In the case of a closed cell, the gas component contained in the cell (a gas component forming a cell, hereinafter sometimes referred to as a "bubble forming gas") is not particularly limited. For example, nitrogen, carbon dioxide, argon, etc. Other than the active gas, various gas components such as air can be mentioned. Moreover, as a bubble formation gas, when performing the polymerization reaction of a synthetic resin, etc. in the state in which this bubble formation gas was contained, it is preferable to use the thing which does not inhibit the reaction. From this point of view, cost, etc., nitrogen can be suitably employed as the bubble-forming gas.

The shape of the air bubble is typically, but not limited to, generally spherical. The average diameter (average cell diameter) of the cells is not particularly limited, and is, for example, usually 1 to 1,000 μm, preferably 10 to 500 μm, and more preferably 30 to 300 μm.
The average cell diameter is usually 50% or less of the thickness of the foam sheet, preferably 30% or less, and more preferably 10% or less.

  In addition, the above-mentioned average bubble diameter can be typically determined by a scanning electron microscope (SEM), and it is determined by arithmetically averaging the results of measuring the diameters of 10 or more bubbles. preferable. At this time, with regard to the non-spherical bubbles, the average pore diameter is determined by converting them into spherical bubbles having the same volume.

  When the foam sheet has air bubbles, the volume ratio (air bubble content rate) of the air bubbles in the foam sheet is not particularly limited, and can be appropriately set so as to achieve desired cushioning properties and flexibility. For example, it can be about 3 to 70% by volume with respect to the volume of the foam sheet (refers to the apparent volume and can be calculated from the thickness and area of the foam sheet), and usually about 5 to 50% by volume It is appropriate that the ratio is about 8 to 40% by volume.

  The method for forming the foam sheet is not particularly limited, and any known method can be adopted as appropriate. For example, (1) A synthetic resin composition (preferably, a composition of the type that cures with active energy rays such as ultraviolet light to form a visco-elastic body) in which a bubble-forming gas is mixed beforehand to cure bubble-containing viscoelasticity A method of forming a body layer, (2) a method of forming a bubble-containing visco-elastic body layer, etc. can be appropriately adopted by forming a bubble from the foaming agent using a synthetic resin composition containing a foaming agent. The foaming agent to be used is not particularly limited, and can be appropriately selected from known foaming agents. For example, a foaming agent such as thermally expandable microspheres can be preferably used.

  In the formation of the bubble-containing viscoelastic layer by the method (1), the method for preparing the synthetic resin composition in which the bubble-forming gas is mixed is not particularly limited, and a known bubble mixing method can be used. For example, as an example of a bubble mixing apparatus, a stator having a large number of fine teeth on a disk having a through hole at the center, and a rotor facing the stator and having fine teeth similar to the stator on the disk And the like. A gas component (bubble-forming gas) for forming bubbles while introducing a composition before mixing of bubbles between the teeth on the stator and the teeth on the rotor in such a bubble mixing device and rotating the rotor at high speed Are introduced through the through holes. Thereby, a synthetic resin composition in which air bubbles are finely dispersed and mixed is obtained.

  A bubble-containing viscoelastic body layer can be formed by applying and curing the synthetic resin composition mixed with the bubble-forming gas on a predetermined surface. As a curing method, a method of heating, a method of irradiating active energy rays (for example, ultraviolet rays), and the like can be preferably employed. A foam sheet can be suitably formed by performing heating, active energy ray irradiation, etc. to the synthetic resin composition with which bubble formation gas was mixed, and hardening it in the state which hold | maintained the bubble stably.

A surfactant may be added to the synthetic resin composition from the viewpoint of the mixing property of the bubble forming gas and the stability of the bubbles. Examples of such surfactants include ionic surfactants, hydrocarbon surfactants, silicone surfactants, fluoro surfactants and the like. Among them, fluorine surfactants are preferable, and fluorine surfactants having an oxyalkylene group (typically, an oxyalkylene group having 2 to 3 carbon atoms) and a fluorinated hydrocarbon group in the molecule are particularly preferable. The fluorine-based surfactants can be used singly or in combination of two or more. As a commercial item of a preferable fluorochemical surfactant, the brand name "Surflon S-393" by AGC Seimi Chemical Co., Ltd. is mentioned, for example.
The amount of surfactant used is not particularly limited. For example, the amount is usually about 0.01 to 3 parts by weight on the basis of solid content with respect to 100 parts by weight of the synthetic resin contained in the foam sheet.

  The foam sheet is, for example, a known plasticizer, softener, coloring agent (pigment, dye, etc.), antioxidant, leveling agent, stabilizer, preservative, etc. to the extent that the effect of the present invention is not significantly impaired. You may contain the additive as needed. Specifically, when a synthetic resin composition is cured by photopolymerization to form a foam sheet, in order to color the foam sheet, a pigment (coloring pigment) which does not separate photopolymerization is used as a colorant. It can be used. When black is desired as coloring of a foam sheet, carbon black can be preferably used as a coloring agent, for example. The amount of carbon black used is, for example, 0.15% by weight or less, preferably 0.001 to 0.15% by weight, and more preferably, in consideration of the degree of coloring, photopolymerization reactivity, etc. It is 0.01 to 0.1% by weight.

  The thickness of the substrate is, for example, preferably 1 to 1,000 μm, particularly preferably 2 to 500 μm, and further preferably 3 to 300 μm.

  As the above-mentioned release sheet, for example, a sheet made of various synthetic resins exemplified for the above-mentioned base material, paper, cloth, non-woven fabric or the like which has been subjected to release treatment can be used. It is preferable to use a silicon-based release sheet as the release sheet.

  As a method of applying the pressure-sensitive adhesive composition, for example, 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, a comma coater or the like may be used.

  As conditions for the above-mentioned curing treatment, the temperature is usually room temperature (23 ° C.) to 70 ° C., and the time is usually 1 to 30 days, and specifically, for example, 1 day to 23 ° C., preferably 3 days at 23 ° C. It may be carried out under the conditions such as 14 days and 40 ° C. and 1 to 10 days.

  The drying temperature is preferably 60 to 140 ° C., particularly preferably 80 to 120 ° C., and the drying time is preferably 0.5 to 30 minutes, and more preferably 1 to 5 minutes.

  The thickness of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet or 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. When the thickness of the pressure-sensitive adhesive layer is too thin, the adhesive strength tends to decrease, and when it is too thick, it becomes difficult to apply uniformly, and a defect such as air bubbles in the coating tends to easily occur. is there. In addition, when considering shock absorption, it is preferable to set it as 50 micrometers or more.

  In addition, the thickness of the said adhesive layer is calculated | required by deducting the measured value of thickness of structural members other than an adhesive layer from the measured value of the thickness of the whole adhesive sheet using Mitutoyo company make "ID-C112B" .

  The gel fraction of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is preferably 10% by weight or more, particularly preferably 15 to 95% by weight, and more preferably 20 to 90% by weight from the viewpoint of durability and adhesion. is there. If the gel fraction is too low, the cohesion will decrease and the durability will tend to decrease. If the gel fraction is too high, the cohesion will increase and the cohesion will tend to decrease.

  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 (having no release sheet) formed by forming a pressure-sensitive adhesive layer on a polymer sheet (for example, a PET film etc.) to be a base material is wrapped with 200 mesh SUS wire mesh and It is immersed at 23 ° C. for 24 hours, and the weight percentage of the undissolved pressure-sensitive adhesive component remaining in the wire mesh is taken as a gel fraction. However, the weight of the substrate is deducted.

  Further, such a pressure-sensitive adhesive sheet may be protected by providing a release sheet on the outside of the pressure-sensitive adhesive layer, if necessary. In the pressure-sensitive adhesive sheet in which the pressure-sensitive adhesive layer is formed on one side of the substrate, the surface of the substrate opposite to the pressure-sensitive adhesive layer is subjected to a release treatment to use the release-treated surface It is also possible to protect the

  Further, the pressure-sensitive adhesive of the present invention can be used for bonding of various members, and among them, it is preferable to use as a pressure-sensitive adhesive for optical members used for bonding of optical members, and it comprises such a pressure-sensitive adhesive composition By laminating the pressure-sensitive adhesive layer of the pressure-sensitive adhesive on the optical member, the pressure-sensitive adhesive layer-carrying optical member can be obtained.

  Such optical members include transparent electrode films such as ITO electrode films and inorganic or organic conductive films such as polythiophene, polarizing plates, retardation plates, elliptical polarizing plates, optical compensation films, brightness enhancement films, electromagnetic wave shielding films, and so on. An infrared absorption film, AR (antireflection) 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 strength can be obtained, and an ITO electrode film is particularly preferable. Although the ITO electrode film is often formed as a thin film on a substrate such as glass or PET, in the present invention, a film in which the ITO electrode film is formed as a thin film on a PET substrate is 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, and the light-diffusion sheet of a liquid crystal display.

  In the pressure-sensitive adhesive layer-carrying optical member, it is preferable to further provide a release sheet on the side opposite to the optical member surface of the pressure-sensitive adhesive layer, and for practical use, release the release sheet. Bond the pressure-sensitive adhesive layer and the adherend. As such a release sheet, it is preferable to use a silicon-based release sheet.

EXAMPLES Hereinafter, the present invention will be more specifically described by way of examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In the examples, "part" and "%" mean weight basis.
Moreover, regarding the measurement of the glass transition temperature of the polyester-based resin in the following Example, it measured according to the above-mentioned method.

<Production of Polyester Resin (A)>
The molar described in the following production examples indicates a molar ratio when the total amount of polyvalent carboxylic acids (a1) is 100 mol%.

[Production of Polyester Resin (A-1)]
66.3 parts (20 mol%) of isophthalic acid (IPA) and sebacine as polyvalent carboxylic acids (a1) in a reaction vessel equipped with a heating device, thermometer, stirrer, rectification column, nitrogen introducing pipe and vacuum device 322.9 parts (80 mol%) of acid (SebA), 207.9 parts (100 mol%) of neopentyl glycol (NPG) as polyol (a2), 89.9 parts of 1,4-butanediol (1.4 BG) (50 mol%), and trimethylolpropane (TMP) 4.0 parts (1.5 mol%), hydrogenated polybutadiene polyol (Nippon Soda Co., Ltd., "GI-1000" as a hydrogenated polybutadiene structure-containing compound (a3) 9.0 parts (0.3 mol%) and 0.05 parts of zinc acetate as a catalyst were charged, the temperature was gradually raised to an internal temperature of 250 ° C., and the esterification reaction was performed 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 the polymerization reaction was performed over 3 hours to produce a polyester resin (A-1).
The glass transition temperature of the obtained polyester-based resin (A-1) is -46.8 ° C., and the structural unit ratio derived from the finished component (hereinafter sometimes abbreviated as "finished component ratio") is a polyvalent carboxylic acid ( Isophthalic acid / sebacic acid = 20 mol% / 80 mol% as a1), neopentyl glycol / 1,4-butanediol / trimethylolpropane / hydrogenated polybutadiene polyol = 64.5 mol% / 33 as polyol (a2). It was 7 mol% / 1.5 mol% / 0.3 mol%.
The content of structural units derived from the hydrogenated polybutadiene structure-containing compound (a3) in the polyester resin (A-1) was 1.7% by weight.

[Production of Polyester Resin (A-2)]
In a reaction vessel equipped with a heating device, thermometer, stirrer, rectification column, nitrogen introducing pipe and vacuum device, 64.6 parts (20 mol%) of isophthalic acid as polyvalent carboxylic acids (a1) and 314. 4 parts (80 mol%), 200.4 parts (99 mol%) of neopentyl glycol as polyol (a2), 87.6 parts (50 mol%) of 1,4-butanediol, and 3.9 parts of trimethylolpropane (1.5 mol%), a hydrogenated polybutadiene polyol (Nippon Soda Co., Ltd., “GI-1000”) 29.1 parts (1 mol%) as a hydrogenated polybutadiene structure-containing compound (a3), and zinc acetate 0. 2 as a catalyst. 05 parts were charged, the temperature was gradually raised to an internal temperature of 250 ° C., and the esterification reaction was performed 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 the polymerization reaction was performed over 3 hours to produce a polyester resin (A-2).
The glass transition temperature of the obtained polyester resin (A-2) is -47.7 ° C, the finished component ratio is isophthalic acid / sebacic acid = 20 mol% / 80 mol% as polyvalent carboxylic acids (a1), polyol Neopentyl glycol / 1,4-butanediol / trimethylolpropane / hydrogenated polybutadiene polyol = 63.8 mol% / 33.7 mol% / 1.5 mol% / 1 mol% as (a2).
The content of structural units derived from the hydrogenated polybutadiene structure-containing compound (a3) in the polyester resin (A-2) was 5.5% by weight.

[Production of Polyester Resin (A-3)]
In a reaction vessel equipped with a heating device, thermometer, stirrer, rectification column, nitrogen introduction tube and vacuum device, 43.7 parts (20 mol%) of isophthalic acid and 20 g% of sebacic acid as polyvalent carboxylic acids (a1). 7 parts (80 mol%), 123.2 parts (90 mol%) of neopentyl glycol as polyol (a2), 59.2 parts (50 mol%) of 1,4-butanediol, and 3.5 parts of trimethylolpropane (1.5 mol%) As a hydrogenated polybutadiene structure-containing compound (a3), 157.7 parts (8 mol%) of a hydrogenated polybutadiene polyol ("GI-1000" manufactured by Nippon Soda Co., Ltd.) 05 parts were charged, the temperature was gradually raised to an internal temperature of 250 ° C., and the esterification reaction was performed 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 the polymerization reaction was carried out over 3 hours to produce a polyester resin (A-3).
The glass transition temperature of the obtained polyester resin (A-3) is -47.5 ° C, and the finished component ratio is isophthalic acid / sebacic acid = 20 mol% / 80 mol% as polyvalent carboxylic acids (a1), polyol As (a2), neopentyl glycol / 1,4-butanediol / trimethylolpropane / hydrogenated polybutadiene polyol = 56.9 mol% / 33.1 mol% / 2 mol% / 8 mol%.
The content of structural units derived from the hydrogenated polybutadiene structure-containing compound (a3) in the polyester resin (A-3) was 32.3% by weight.

[Production of Polyester Resin (A-4)]
67.4 parts (20 mol%) of isophthalic acid as polyvalent carboxylic acids (a1), azelaic acid (AzA), as a polyvalent carboxylic acid (a1), in a reaction vessel equipped with a heating apparatus, thermometer, stirrer, rectification column, nitrogen introducing pipe and vacuum apparatus ) 152.7 parts (40 mol%) and 164.1 parts (40 mol%) sebacic acid, 211.2 parts (100 mol%) of neopentyl glycol as polyol (a2), 91.4 parts of 1,4-butanediol Parts (50 mol%), and 4.1 parts (1.5 mol%) of trimethylolpropane, and a hydrogenated polybutadiene polyol (Nippon Soda Co., Ltd. "GI-1000") 9 as a hydrogenated polybutadiene structure-containing compound (a3) .1 part (0.3 mol%), 0.05 part of zinc acetate as a catalyst 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., 0.05 part of tetrabutyl titanate was charged as a catalyst, the pressure was reduced to 1.33 hPa, and the polymerization reaction was carried out over 3 hours to produce a polyester resin (A-4).
The glass transition temperature of the obtained polyester resin (A-4) is −45.7 ° C., and the finished component ratio is isophthalic acid / azelaic acid / sebacic acid = 20 mol% / 40 mol as polyvalent carboxylic acids (a1) % / 40 mol% neopentyl glycol / 1,4-butanediol / trimethylolpropane / hydrogenated polybutadiene polyol = 64.5 mol% / 33.7 mol% / 1.5 mol% / 0 as the polyol (a2) It was .3 mol%.
The content of structural units derived from the hydrogenated polybutadiene structure-containing compound (a3) in the polyester resin (A-4) was 1.7% by weight.

[Production of Polyester Resin (A-5)]
308.6 parts (100 mol%) of azelaic acid as polyvalent carboxylic acids (a1) in a reaction vessel equipped with a heating device, thermometer, stirrer, rectification column, nitrogen introducing pipe and vacuum device, polyol (a2) 163.9 parts (96 mol%) of neopentyl glycol, 73.9 parts (50 mol%) of 1,4-butanediol, and 4.4 parts (2 mol%) of trimethylolpropane, a hydrogenated polybutadiene structure-containing compound As (a3), 49.2 parts (2 mol%) of hydrogenated polybutadiene polyol (manufactured by Nippon Soda Co., Ltd., “GI-1000”), 0.05 parts of zinc acetate as a catalyst are charged, and the temperature is gradually increased to an internal temperature of 250 ° C. The reaction was carried out for 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 the polymerization reaction was performed for 3 hours to produce a polyester resin (A-5).
The glass transition temperature of the obtained polyester resin (A-5) is -59.4 ° C., and the finished component ratio is 100 mol% of azelaic acid as polyvalent carboxylic acids (a1), neopentyl glycol as polyol (a2) / 1,4-butanediol / trimethylolpropane / hydrogenated polybutadiene polyol = 62.2. It was mol% / 33.8 mol% / 2 mol% / 2 mol%.
The content of structural units derived from the hydrogenated polybutadiene structure-containing compound (a3) in the polyester resin (A-5) was 10.7% by weight.

[Production of polyester resin (A'-1)]
In a reaction vessel equipped with a heating apparatus, thermometer, stirrer, rectification column, nitrogen introducing pipe and vacuum apparatus, 16.9 parts (20 mol%) of isophthalic acid and 80% of sebacic acid as polyvalent carboxylic acids (a1). 1 part (80 mol%), 20.1 parts (38 mol%) of neopentyl glycol as polyol (a2), 22.9 parts (50 mol%) of 1,4-butanediol, and 1.4 parts of trimethylolpropane (1.5 mol%) As a hydrogenated polybutadiene structure-containing compound (a3), 456.7 parts (60 mol%) of a hydrogenated polybutadiene polyol ("GI-1000" manufactured by Nippon Soda Co., Ltd.) 02 parts were charged, the temperature was gradually raised to an internal temperature of 250 ° C., and an esterification reaction was carried out 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 the polymerization reaction was carried out over 3 hours to produce a polyester resin (A′-1).
The glass transition temperature of the obtained polyester resin (A′-1) is −43.6 ° C., and the finished component ratio is isophthalic acid / sebacic acid = 20 mol% / 80 mol% as polyvalent carboxylic acids (a1) Neopentyl glycol / 1,4-butanediol / trimethylolpropane / hydrogenated polybutadiene polyol as the polyol (a2) = 15.3 mol% / 22.7 mol% / 2 mol% / 60 mol%.
The content of structural units derived from the hydrogenated polybutadiene structure-containing compound (a3) in the polyester resin (A'-1) was 80% by weight.

[Production of Polyester Resin (A'-2)]
In a reaction vessel equipped with a heating apparatus, thermometer, stirrer, rectification column, nitrogen introducing pipe and vacuum apparatus, 67.3 parts (20 mol%) of isophthalic acid as polyvalent carboxylic acids (a1) and 327.3 of sebacic acid. 5 parts (80 mol%), 189.7 parts (90 mol%) of neopentyl glycol as the polyol (a2), 91.2 parts (50 mol%) of 1,4-butanediol, 3.5 parts of trimethylolpropane ( (1 mol%), 20.8 parts (9 mol%) of 1,6-hexanediol (1.6 HG), and 0.05 parts of zinc acetate as a catalyst, gradually raising the temperature to an internal temperature of 250 ° C, 4 The esterification reaction was carried out over time.
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 the polymerization reaction was performed for 3 hours to produce a polyester resin (A′-2).
The glass transition temperature of the obtained polyester resin (A′-2) is −48.5 ° C., and the finished component ratio is isophthalic acid / sebacic acid = 20 mol% / 80 mol% as polyvalent carboxylic acids (a1) Neopentyl glycol / 1,4-butanediol / trimethylolpropane / 1,6-hexanediol = 58.5 mol% / 34.0 mol% / 1.3 mol% / 6.2 mol% as the polyol (a2) Met.
The content of structural units derived from the hydrogenated polybutadiene structure-containing compound (a3) in the polyester resin (A'-2) was 0% by weight.

  The results of the resin composition (structural units derived from finished components) and the glass transition temperature (Tg) of the obtained polyester resin (A) are shown in Table 1 below.

<Production of polyester-based pressure-sensitive adhesive composition>
The polyester-based pressure-sensitive adhesive compositions of the following Examples and Comparative Examples are manufactured using each of the polyester-based resins obtained above, and the haze and solution transparency are evaluated according to the following evaluation criteria, and the gel fraction is the method described above The results are shown in Table 2.

Example 1
The polyester resin (A-1) obtained above is diluted with toluene to a solid concentration of 50%, and the hydrolysis is suppressed with respect to 200 parts (100 parts as solid content) of the polyester resin (A-1) solution. Agent (Nisshinbo Chemical Co., Ltd., “Carbodilite V-09BG”) 1 part (solid content) and 3 parts of trimethylolpropane / tolylene diisocyanate adduct (Tosoh Corp., “Coronato L55E”) as a crosslinking agent (solid content) By blending 0.01 part (solid content) of a zirconium-based compound (Matsumoto Fine Chemical Co., Ltd., “Orgatics ZC-150”) diluted to 1% solid content concentration with acetylacetone as a urethanization catalyst, stirring and mixing, A polyester-based pressure-sensitive adhesive composition was obtained.

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

(Example 3)
A polyester-based pressure-sensitive adhesive composition was obtained in the same manner as in Example 1 except that the polyester-based resin (A-1) was changed to the polyester-based resin (A-3) in Example 1.

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

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

(Comparative example 1)
A polyester-based pressure-sensitive adhesive composition was obtained in the same manner as in Example 1 except that the polyester-based resin (A-1) was changed to the polyester-based resin (A′-1) in Example 1.

(Comparative example 2)
Example 1 was repeated except that polyester resin (A-1) was changed to polyester resin (A'-2), 3 parts of crosslinking agent to 2 parts, and toluene to ethyl acetate. Thus, a polyester-based pressure-sensitive adhesive composition was obtained.

  Evaluation is performed as follows using the obtained polyester-based pressure-sensitive adhesive composition, and the results are shown in Table 2 below.

<Production of adhesive sheet with release film on both sides>
The polyester-based pressure-sensitive adhesive composition obtained in Examples 1 to 5 and Comparative Examples 1 and 2 was treated with a 38 μm-thick PET release film (Mitsui Chemicals Tosoh Co., “SP-PET-03-BU”) (α The solution was applied using an applicator and dried at 100 ° C. for 4 minutes to obtain a pressure-sensitive adhesive sheet with a release film having a thickness of 50 μm.
Next, the surface of the pressure-sensitive adhesive composition layer of the obtained release film-attached pressure-sensitive adhesive sheet has a thickness of 38 μm and a release film made of PET having a peeling force different from that of the release film (α) It covered with PET-01-BU ") ((beta), and the aging process was performed at 40 degreeC for 4 days, and the adhesive sheet with a double-sided release film was obtained.

<Adhesive sheet production with single-sided release film>
The polyester-based pressure-sensitive adhesive composition obtained in Examples 1 to 5 and Comparative Examples 1 and 2 is applied onto a 38 μm-thick PET film (“Lumirror T60” manufactured by Toray Industries, Inc.) using an applicator, and the temperature is 100 ° C. It dried for 3 minutes with this, and the thickness of the adhesive composition layer obtained the 25-micrometer-thick adhesive sheet with a PET film.
Next, the surface of the pressure-sensitive adhesive composition layer of the obtained PET film-attached pressure-sensitive adhesive sheet is covered with a 38 μm-thick PET release film (β), subjected to aging treatment at 40 ° C. for four days, Obtained.

<Adhesive sheet evaluation>
[Adhesive force]
The single-sided release film-attached pressure-sensitive adhesive sheet obtained above is cut into a size of 25 mm × 200 mm under an environment of 23 ° C. and 50% RH, and then the release film (β) is peeled off, and the pressure-sensitive adhesive layer side is A 2 kg roller is reciprocated on each of mirror finished stainless steel plate (SUS-BA plate) and polypropylene (PP) plate, and pressure applied and left for 24 hours under the same atmosphere, and then an autograph (manufactured by Shimadzu Corporation, “ The degree of 180 degree peeling (N / 25 mm) was measured at a peeling speed of 300 mm / min using Autograph AGS-H 500N ").

[Haze]
The release film (β) on one side is peeled off from the pressure-sensitive adhesive layer of the double-sided release film-attached pressure-sensitive adhesive sheet obtained above, and the pressure-sensitive adhesive layer side is bonded to an alkali-free glass plate (Eagle XG, manufactured by Corning) Then, the other release film (α) was peeled off to obtain an alkali-free glass plate with an adhesive layer. The haze of the non-alkali glass plate with the pressure-sensitive adhesive layer was measured using HAZE MATER NDH 2000 (manufactured by Nippon Denshoku Kogyo Co., Ltd.) and evaluated according to the following criteria. This machine complies with JIS K7361-1.
(Evaluation criteria)
・ ・ ・ ... 1.0% or less ○ ... 1.0% or more and 5.0% or less × ... · 5.0% or more

[Solution transparency (compatibility)]
200 parts (100 parts as solid content) of the polyester-based resin solution used in the above Examples 1 to 5 and Comparative Examples 1 and 2 and 1 part of a hydrolysis inhibitor ("Nisshinbo Chemical Co., Ltd.," Carbodilite V-09BG ") Only (solid content) was compounded to prepare a compounded liquid, and the appearance change before and after the compounding was visually evaluated according to the following criteria.
(Evaluation criteria)
・ ・ ・ ··· No change in appearance ○ · · · 光 light transmitted but turbid × · · light does not transmit turbid

From the results of Table 1 above, the polyester-based pressure-sensitive adhesive compositions of Examples 1 to 5 are excellent not only in adhesion to SUS-BA plates, but also in adhesion to polyolefin substrates such as PP plates, Furthermore, the haze and the solution transparency were also excellent.
On the other hand, although comparative example 1 is excellent in adhesiveness, it was inferior to haze and solution transparency. Moreover, although the comparative example 2 is excellent in a haze and solution transparency, it was inferior to the adhesiveness with respect to polyolefin substrates like PP board.
Therefore, it is understood that the example is an excellent polyester-based pressure-sensitive adhesive composition which achieves both the adhesiveness to the polyolefin substrate, the haze and the solution transparency.

  The polyester-based pressure-sensitive adhesive composition of the present invention is generally excellent in adhesion to a polyolefin substrate having poor adhesion, and further excellent in haze and solution transparency, so a pressure-sensitive adhesive or a pressure-sensitive adhesive sheet using it is The optical member such as a display, an optical film constituting the same, and a base material can be suitably used for bonding the optical members.

Claims (13)

A polyester-based pressure-sensitive adhesive composition comprising a polyester-based resin (A) having a structural unit derived from a hydrogenated polybutadiene structure-containing compound (a3),
Content of the structural unit derived from a hydrogenated polybutadiene structure containing compound (a3) is 0.01-35 weight% with respect to polyester-based resin (A), The polyester-type adhesive composition characterized by the above-mentioned.   The polyester resin (A) has a structural unit derived from a polyvalent carboxylic acid (a1) and a structural unit derived from a polyol (a2), and the above-mentioned hydrogenated polybutadiene structure-containing compound (a3) is contained in the polyol (a2) The hydrogenated polybutadiene polyol (a3-1) is characterized in that the structural unit derived from the hydrogenated polybutadiene structure-containing compound (a3) is contained in an amount of 0.001 to 10 mol% in the structural unit derived from the polyol (a2). The polyester-based pressure-sensitive adhesive composition as claimed in claim 1.   The polyester-based pressure-sensitive adhesive composition according to claim 2, characterized in that it contains an asymmetric aromatic polyvalent carboxylic acid (a1-1) as the polyvalent carboxylic acid (a1).   The polyester-based pressure-sensitive adhesive composition according to claim 2 or 3, wherein an aliphatic polyvalent carboxylic acid (a1-2) having an odd number of carbon atoms is contained as the polyvalent carboxylic acid (a1).   The polyester-based pressure-sensitive adhesive composition according to any one of claims 2 to 4, which contains a branched structure-containing polyol (a2-1) as the polyol (a2).   The polyester-based pressure-sensitive adhesive composition according to any one of claims 2 to 5, which contains a linear polyol (a2-2) as the polyol (a2).   The glass transition temperature of polyester-based resin (A) is -80-20 degreeC, The polyester-based adhesive composition as described in any one of Claims 1-6 characterized by the above-mentioned.   The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 7, further comprising a hydrolysis inhibitor (B).   The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 8, further comprising a urethanization catalyst (C).   The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 9, further comprising a crosslinking agent (D).   The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 10, which is crosslinked.   A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer containing the polyester-based pressure-sensitive adhesive according to claim 11.   A pressure-sensitive adhesive layer-carrying optical member comprising a pressure-sensitive adhesive layer containing the polyester-based pressure-sensitive adhesive according to claim 11 and an optical member.