JP7103137B2 - Polyester-based adhesive composition, polyester-based adhesive, adhesive sheet and optical member with adhesive layer - Google Patents

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. The present invention relates to a 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.

Conventionally, polyester resins have excellent 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, electrical parts, and adhesives and adhesives. It is used.

Further, in recent years, display devices such as liquid crystal displays (LCD: Liquid Crystal Display) 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, optics A transparent adhesive sheet is used for bonding optical members such as films and base materials.

As such an adhesive sheet, for example, a film with an adhesive using a polyester-based adhesive composition having a hydrogenated polybutadiene skeleton is used, and the adhesive is adhered to a metal plate in order to achieve both adhesiveness and cohesiveness. Sheets have been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 3-167284

However, in Patent Document 1, although adhesiveness to a metal plate can be obtained, adhesiveness to a polyolefin base material, which is generally inferior in adhesiveness, is not considered at all, and an adhesive sheet is used. It was not satisfactory in terms of solution transparency as a haze or adhesive composition.
Further, in recent years, applications using a polyolefin base material as an adherend, for example, applications such as automobile interior / exterior materials and building materials, are increasing, and there is an extremely high demand for adhesiveness to the polyolefin base material.

Therefore, in the present invention, under such a background, a polyester-based pressure-sensitive adhesive composition, a polyester-based pressure-sensitive adhesive, a pressure-sensitive adhesive sheet, and a pressure-sensitive adhesive layer, which are excellent in adhesiveness to a polyolefin substrate and also excellent in haze and solution transparency, are provided. It is an object of the present invention to provide an optical member.

However, as a result of diligent research in view of such circumstances, the present inventor has made the polyester-based resin contain a hydrogenated polybutadiene structure, and by making the content relatively smaller than before, the polyolefin base material can be obtained. The present invention has been completed by finding that the polyester-based pressure-sensitive adhesive composition has excellent transparency as well as excellent adhesiveness.

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

The second gist of the present invention is a polyester-based pressure-sensitive adhesive obtained by cross-linking the polyester-based pressure-sensitive adhesive composition, and a third gist is a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer containing the polyester-based pressure-sensitive adhesive. And. Further, the fourth gist is an optical member with a pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer containing a polyester-based pressure-sensitive adhesive and an optical member, which is the second gist.

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

Further, when it is applied to a polyolefin substrate which is generally inferior in adhesiveness, it is usual to consider increasing the content thereof. However, sufficient compatibility between the pressure-sensitive adhesive and the polyester-based resin cannot be obtained, and it becomes difficult to balance the pressure-sensitive adhesive properties due to the white turbidity of the pressure-sensitive adhesive layer and the decrease in low-temperature tackiness, which may result in poor adhesive reliability.

Further, in order to improve the adhesiveness of the polyester-based pressure-sensitive adhesive composition to the substrate, it is conceivable to include a hydrogenated polybutadiene structure, and as with the pressure-sensitive adhesive, increasing the content thereof will improve the effect. However, sufficient compatibility cannot be obtained, and it becomes difficult to balance the adhesive properties due to the white turbidity of the adhesive layer and the decrease in cohesive force.

In the present invention, the content of the hydrogenated polybutadiene structure of the polyester resin is surprisingly relatively small without using a tackifier, so that the adhesiveness to the polyolefin base material is excellent, and haze and solution are obtained. They found that it was also excellent in transparency.

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 the hydrogenated polybutadiene structure-containing compound (a3), and 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 adhesiveness to the polyolefin base material is excellent, and the haze and solution transparency are improved. Is also excellent.

Hereinafter, the configuration of the present invention will be described in detail, but these are examples of desirable embodiments.
In the present invention, the term "carboxylic acid" includes not only carboxylic acid but also carboxylic acid derivatives such as carboxylic acid salt, carboxylic acid anhydride, carboxylic acid halide, and carboxylic acid ester.

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

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

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

<Polyester resin (A)>
The polyester 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 resin (A) is the polyester resin (A). The resin composition will have a structural unit derived from the polyvalent carboxylic acids (a1) and a structural unit derived from the polyol (a2).

The polyester resin (A) used in the present invention can be obtained by copolymerizing a hydrogenated polybutadiene structure-containing compound (a3), and the hydrogenated polybutadiene structure-containing compound (a3) is a polyester resin (A). ) Is preferably contained as at least one of the polyvalent carboxylic acids (a1) and the polyol (a2), which are the constituent raw materials.

[Multivalent carboxylic acids (a1)]
Examples of the polyvalent carboxylic acids (a1) used as a constituent raw material of the polyester resin (A) include divalent 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 obtaining the above.

Examples of the divalent carboxylic acids include malonic acids, dimethylmalonic acids, succinic acids, glutaric acids, adipic acids, trimethyladiponic acids, pimeric acids, 2,2-dimethylglutaric acids, azelaic acids, sebacic acids, fumaric acids, and the like. Aliphatic dicarboxylic acids such as maleic acids, itaconic acids, thiodipropionic acids, diglycolic acids, 1,9-nonandicarboxylic acids, etc.;
Phtalic acids, terephthalic acids, isophthalic acids, benzylmalonic acids, diphenic acids, 4,4'-oxydibenzoic acids, 1,8-naphthalenedicarboxylic acids, 2,3-naphthalenedicarboxylic acids, 2,7-naphthalenedicarboxylic acids, etc. Naphthalenedicarboxylic acids, such as aromatic dicarboxylic acids;
Oil rings of 1,3-cyclopentanedicarboxylic acids, 1,2-cyclohexanedicarboxylic acids, 1,3-cyclopentanedicarboxylic acids, 1,4-cyclohexanedicarboxylic acids, 2,5-norbornandicarboxylic acids, adamantandicarboxylic acids, etc. Group dicarboxylic acids;
And so on.

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

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

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

Further, among the 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. It is preferable that the aliphatic polyvalent carboxylic acids (a1-2) having an odd number of carbon atoms include, for example, malonic acids, glutaric acids, pimelli acids, azelaic acids, 1,9-nonandicarboxylic acids and the like. However, azelaic acids are particularly preferably used.

The content of the aliphatic polyvalent carboxylic acid (a1-2) having an odd number of carbon atoms is preferably 5 to 100 mol% with respect to the entire polyvalent carboxylic acid (a1). In particular, when the transparency of the solution is emphasized, it is preferably 5 to 100 mol%, particularly preferably 10 to 100 mol%, and further preferably 20 to 100 mol% with respect to the whole polyvalent carboxylic acid (a1). %, Especially preferably 30 to 100 mol%. If the content is too small, the resin tends to crystallize and sufficient adhesive performance cannot be obtained.
When the adhesiveness to the polyolefin substrate is important, the content is preferably 5 to 100 mol%, more preferably 10 to 95% mol%, still more preferably, based on the total polyvalent carboxylic acids (a1). Is 20 to 90 mol%, particularly preferably 30 to 80 mol%. If the content is too small, the resin tends to crystallize and sufficient adhesive performance cannot be obtained. If the amount is too large, the adhesiveness to the polyolefin substrate tends to decrease.

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

For the purpose of increasing the number of bifurcation points in the polyester resin (A), polyvalent carboxylic acids having a trivalent value or higher can be used, and among them, trimellitic acids are used because gelation is relatively unlikely to occur. Is preferable.

The content of the trivalent or higher polyvalent carboxylic acids is preferably 10 mol% or less, particularly preferably 10 mol% or less, based on the total polyvalent carboxylic acids (a1) in that the cohesive force of the pressure-sensitive adhesive can be enhanced. It is 0.1 to 5 mol%, and if the content is too large, gelation tends to occur easily during the production of the polyester resin (A).

[Polyol (a2)]
Examples of the polyol (a2) used as a constituent raw material of the polyester resin (A) include a dihydric alcohol and a trivalent or higher polyol.

Examples of the dihydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, and 2, -Methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl -1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2,2 , 4-trimethyl-1,6-hexanediol and other aliphatic diols;
1,2-Cyclohexanedimethanol, 1,3-Cyclohexanedimethanol, 1,4-Cyclohexanedimethanol, Spiroglycol, Tricyclodecanedimethanol, adamantandiol, 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 Examples thereof include aromatic diols such as those ethylene oxide adducts and propylene oxide adducts.
Further, fatty acid esters derived from castor oil, dimerdiol derived from oleic acid, erucic acid and the like, glycerol monostearate and the like can be mentioned.
Examples of the trivalent or higher-valent polyol include pentaerythritol, dipentaerythritol, tripentaerythritol, glycerin, trimethylolpropane, trimethylolethane, 1,3,6-hexanetriol, and adamantanetriol.
The above-mentioned polyols (a2) can be used alone or in combination of two or more.

Among the above-mentioned polyols (a2), it is preferable to contain the branched structure-containing polyol (a2-1) from the viewpoint of increasing the number of branching points and destroying the crystallinity. Examples of the branched structure-containing polyol (a2-1) include neopentyl glycol, 2-methyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol, and 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 and the like can be mentioned. Be done. Of these, neopentyl glycol is particularly preferable. Further, the branched structure-containing polyol preferably has a molecular weight of 1,000 or less.
The branched structure-containing polyol (a2-1) excludes the hydrogenated polybutadiene polyol (a3-1) described later.

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 entire polyol (a2). It is preferable to have. If the content is too small, the resin tends to crystallize and it tends to be difficult to obtain sufficient adhesive performance, and if it is too large, the reaction time tends to be long in the production of the polyester resin (A).

On the other hand, among the above-mentioned polyols (a2), it is preferable to contain a linear polyol (a2-2) from the viewpoint of reactivity, and a linear polyol having 2 to 40 carbon atoms is more preferable. Examples of such linear polyol (a2-2) include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, and dipropylene glycol. , 1,9-Nonandiol, 1,10-decanediol, 1,12-dodecanediol, and other aliphatic glycols. Of these, 1,4-butanediol is particularly preferable.

The content of the linear polyol (a2-2) is preferably 1 to 100 mol%, more preferably 3 to 99.999 mol%, and particularly 5 to 99.99, based on the total polyol (a2). It is preferably mol%, more preferably 7-99.9 mol%, particularly 10-99.5 mol%. If the content is too small, it tends to be difficult to obtain stable resin formation.

Further, a trivalent or higher polyol can be used in the polyester resin (A) for the purpose of increasing branching points, and examples of the trivalent or higher polyol include pentaerythritol, dipentaerythritol, tripentaerythritol, and glycerin. Examples thereof include trimethylolpropane, trimethylolethane, 1,3,6-hexanetriol, and adamantantriol.

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

The mixing ratio of the polyvalent carboxylic acid (a1) and the polyol (a2) is preferably 1 to 3 equivalents per 1 equivalent of the polyvalent carboxylic acid (a1), and particularly preferably 1.1. ~ 2 equivalents. If the compounding ratio of the polyol (a2) is too small, the acid value tends to be high and it tends to be difficult to increase the molecular weight, and if it is too large, the yield tends to decrease.

[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 raw material of such a polyester resin (A), but from the viewpoint of achieving the object of the present invention, the polyvalent carboxylic acids (a1) And, as at least one of the polyol (a2), it is preferable to contain the hydrogenated polybutadiene structure-containing compound (a3).

Examples of the hydrogenated polybutadiene structure-containing compound (a3) contained in the polyvalent carboxylic acids (a1) include 1,2-polybutadienedicarboxylic acids, 1,4-polybutadienedicarboxylic acids, and 1,2-polychloroplenedicarboxylic acids. Polybutadiene-based polyvalent carboxylic acids such as 1,4-polychloroplenedicarboxylic acids, or chain polyethylene polyvalent carboxylic acids in which the double bonds of these polybutadiene-based polyvalent carboxylic acids are saturated with hydrogen, halogen, etc., chlorinated polyethylene There are polyvalent carboxylic acids and saturated hydrocarbon-based polyvalent carboxylic acids having branches. Further, polyvalent carboxylic acids obtained by copolymerizing polybutadiene-based polyvalent carboxylic acids with olefin compounds such as styrene, ethylene, vinyl acetate, and acrylic acid esters, hydrogenated polyvalent carboxylic acids, and the like can also be used. Of these, hydrocarbon-based polybutadiene polyvalent carboxylic acids having a high degree of saturation are particularly preferably those having a number average molecular weight of 500 to 6,000 and an average functional number 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 mol%, based on the total copolymerization component of the polyester resin (A). It is preferably mol%, particularly 0.01 to 3 mol%, particularly 0.02 to 2 mol%. If the content is too small, the adhesiveness to the polyolefin substrate tends to decrease, and if it is too large, the compatibility tends to decrease.

Further, it is more preferable to contain the hydrogenated polybutadiene structure-containing compound (a3) as the polyol (a2) as a constituent raw material of the polyester resin (A), and particularly preferably, the hydrogenated polybutadiene structure-containing compound. (A3) is a 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, and 1,4-polychloroprene polyol. There are chain polyethylene polyols in which the double bonds of these polybutadiene-based polyols are saturated with hydrogen or halogen, chlorinated polyethylene polyols, saturated hydrocarbon-based polyols having branches, and the like. Further, a polyol obtained by copolymerizing an olefin compound such as styrene, ethylene, vinyl acetate, or acrylic acid ester with a polybutadiene-based polyol, a hydrogenated polyol thereof, or the like can also be used. Of these, hydrocarbon-based polybutadiene polyols having a high degree of saturation are particularly preferably those having a number average molecular weight of 500 to 6,000 and an average number of hydroxyl groups of 1.5 to 3.

Further, as the hydrogenated polybutadiene polyol (a3-1), the olefin base material has a larger proportion of 1,2 bond sites in the 1,2 bond sites and 1,4 bond sites in the structure of the hydrogenated polybutadiene polyol. It is preferable because it has excellent adhesion to. The ratio of 1,2 binding sites to the hydrogenated polybutadiene polyol (a3-1) is preferably 25 to 100%, particularly preferably 50 to 100%, and particularly 75 to 100%. It is preferable to have.

The content of the hydrogenated polybutadiene polyol (a3-1) is preferably 0.001 to 5 mol%, more preferably 0.005 to 4 mol%, based on the total copolymerization component of the polyester resin (A). It is preferably mol%, particularly 0.01 to 3 mol%, particularly 0.02 to 2 mol%. If the content is too small, the adhesiveness to the polyolefin substrate tends to decrease, and if it is too large, the compatibility tends to decrease.

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

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

In such an esterification reaction, a catalyst is usually used, and specifically, for example, a titanium-based catalyst such as tetraisopropyl titanate or tetrabutyl titanate, an antimony catalyst such as antimony trioxide, or a germanium-based catalyst such as germanium dioxide. Such as catalysts and catalysts such as zinc acetate, manganese acetate, dibutyltin oxide and the like can be mentioned, and one or more of these catalysts are used. Among these, antimony trioxide, tetrabutyl titanate, germanium dioxide, and zinc acetate are preferable from the viewpoint of high catalytic activity and balance of hue.

The blending amount of the catalyst is preferably 10,000 to 10,000 ppm, particularly preferably 10 to 5,000 ppm, and further preferably 20 to 3,000 ppm with respect to the total copolymerization component. If the 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 the reaction time and side reactions tend to occur.

The reaction temperature during the esterification reaction is preferably 200 to 300 ° C, particularly preferably 210 to 280 ° C, and even more preferably 220 to 260 ° C. If the reaction temperature is too low, the reaction tends to be difficult to proceed sufficiently, and if it is too high, side reactions such as decomposition tend to occur. The pressure during the reaction is usually under normal pressure.

After the above esterification reaction is carried out, a polycondensation reaction is carried out.
As the reaction conditions of the polycondensation reaction, the same catalyst as that used in the above esterification reaction is further blended in the same amount, and the reaction temperature is preferably 220 to 280 ° C, particularly preferably 230 to 270 ° C. It is preferable that the system is gradually depressurized and finally reacted at 5 hPa or less. If the reaction temperature is too low, the reaction tends to be difficult 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 can be 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). However, it is 0.01 to 35% by weight, preferably 0.1 to 30% by weight, particularly preferably 0.2 to 20% by weight, still more preferably 0.3 to 10% by weight, and more preferably 0.4. It is ~ 5% by weight, particularly preferably 0.5 ~ 3% by weight.

Further, in the polyester resin (A), the structural unit derived from the hydrogenated polybutadiene structure-containing compound (a3) is at least one of the structural unit derived from the polyvalent carboxylic acids (a1) and the structural unit derived from the polyol (a2). It is preferable that it is contained as a structural unit derived from the polyol (a2), and more preferably it is contained as a structural unit derived from the polyol (a2).

Further, when the structural unit derived from the hydrogenated polybutadiene polyol (a3-1) is included as the structural unit derived from the polyol (a2), the structural unit derived from the hydrogenated polybutadiene polyol (a3-1) is the polyol (a2). ) Is preferably contained in the structural unit derived from 0.001 to 10 mol% from the viewpoint of compatibility, more preferably 0.01 to 8 mol%, particularly preferably 0.03 to 5 mol%, and 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 acids (a1) and a structural unit derived from the polyol (a2), but the asymmetric aromatic polyvalent carboxylic acids (a1-1). When the derived structural unit is included as the structural unit derived from the polyvalent carboxylic acids (a1), the structural unit derived from the asymmetric aromatic polyvalent carboxylic acids (a1-1) is derived from the polyvalent carboxylic acids (a1). It is preferably 1 to 90 mol%, particularly preferably 2 to 80 mol%, further preferably 3 to 60 mol%, more preferably 4 to 50 mol%, and particularly preferably 5 to 40 mol% in the structural unit of. Mol%.

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

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

When the structural unit derived from the linear polyol (a2-2) is included as the 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 to contain 3 to 95 mol% in the structural unit of the above from the viewpoint of stable resin formation, more preferably 5 to 90 mol%, particularly preferably 10 to 80 mol%, and particularly preferably 15 to 60 mol%. be.

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

The glass transition temperature of the polyester resin (A) is preferably −80 to 20 ° C., particularly preferably −75 to 15 ° C., still more preferably −65 to 10 ° C., particularly preferably −65 to 10 ° C. from the viewpoint of adhesive physical properties. Is -60 to -30 ° C. If the glass transition temperature is too high, the flexibility is lost, the initial adhesiveness is lowered, the adhesive force is hard to be exhibited at a pressure of about finger pressure, and the workability tends to be lowered. If the glass transition temperature is too low, the cohesive force is lowered. However, the adhesive sheet is easily deformed and tends to spoil the appearance.

Here, the glass transition temperature (Tg) of the polyester 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.

It is preferable that the polyester resin (A) does not crystallize from the viewpoint of storage stability, but even when it is crystallized, it is preferable that the crystallization energy of the polyester resin (A) is as low as possible, and usually 35 J / g. Hereinafter, it is preferably 20 J / g or less, particularly preferably 10 J / g or less, and particularly preferably 5 J / g or less.

The acid value of the police ether resin (A) is preferably 10 mgKOH / g or less, particularly preferably 3 mgKOH / g or less, and further preferably 1 mgKOH / g or less. If the acid value is too high, it tends to corrode when a layer such as metal is laminated on one surface of the pressure-sensitive adhesive layer. For example, when the metal oxide thin film layer is formed, corrosion tends to occur 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.

The weight average molecular weight of the polyester resin (A) is preferably 8,000 to 200,000 from the viewpoint of the cohesive force of the pressure-sensitive adhesive, particularly 10,000 to 180,000, and further 20, It is preferably 000 to 150,000. If the weight average molecular weight is too small, sufficient cohesive force cannot be obtained as an adhesive, and heat resistance and mechanical strength tend to decrease. If the weight average molecular weight is too large, gelation tends to occur during the production of the polyester resin (A). , Resin tends to be difficult to obtain.

The weight average molecular weight of the present invention is a weight average molecular weight converted to a standard polystyrene molecular weight, and is shown on a high-speed liquid chromatograph (manufactured by Toso Co., Ltd., “HLC-8320GPC”) as a column: TSKgel SuperMultipore HZ-M (exclusion limit molecular weight:). It is measured by using 2 x ¹⁰⁶ , theoretical number of stages: 16,000 stages / piece, filler material: styrene-divinylbenzene copolymer, filler particle size: 4 μm) in series. , 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, may be abbreviated as "taste-sensitive adhesive composition") preferably contains a hydrolysis inhibitor (B) together with the polyester-based resin (A). The hydrolysis inhibitor (B) is contained to ensure long-term durability.

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

As the carbodiimide group-containing compound, a known polycarbodiimide having one or more carbodiimide groups (-N = C = N-) in the molecule may be usually used, but the durability under higher temperature and high humidity is improved. In terms of points, a compound containing two or more carbodiimide groups in the molecule, that is, a polyvalent carbodiimide-based compound is preferable, and in particular, a compound containing three or more, further five or more, and particularly seven or more. Is preferable. The number of carbodiimide groups in the molecule is usually 50 or less, and if there are too many carbodiimide groups, the molecular structure becomes too large, which tends to be unfavorable. It is also preferable to use a high molecular weight polycarbodiimide produced by decarboxylating and condensing diisocyanate in the presence of a carbodiimidization catalyst.

Further, the high molecular weight polycarbodiimide having a terminal isocyanate group sealed with a sealant is preferable in terms of storage stability. Examples of the encapsulant include a compound having an active hydrogen that reacts with an isocyanate group and a compound having an isocyanate group. For example, monoalcohols, monocarboxylic acids, monoamines, and monoisocyanates having one substituent selected from a carboxyl group, an amino group, and an isocyanate group can be mentioned.

Examples of such high molecular weight polycarbodiimides include those obtained by decarboxylating and condensing the following diisocyanates.

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

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

As the epoxy group-containing compound, for example, a glycidyl ester compound, a glycidyl ether compound, or the like is preferable.

Specific examples of the glycidyl ester compound include 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, and lauric acid. Glycidyl ester, palmitate glycidyl ester, bechenic acid glycidyl ester, versatic acid glycidyl ester, oleic acid glycidyl ester, linoleic acid glycidyl ester, linoleic acid glycidyl ester, behenolic acid glycidyl ester, stearolic acid glycidyl ester, terephthalic acid diglycidyl ester, Isophthalic acid diglycidyl ester, phthalic acid diglycidyl ester, naphthalenedicarboxylic acid diglycidyl ester, methylterephthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, cyclohexanedicarboxylic acid diglycidyl ester, adipic acid Examples thereof include diglycidyl ester, succinic acid diglycidyl ester, sebacic acid diglycidyl ester, dodecandioic acid diglycidyl ester, octadecane dicarboxylic acid diglycidyl ester, trimellitic acid triglycidyl ester, pyromellitic acid tetraglycidyl ester, and the like. It can be used alone or in combination of two or more.

Specific examples of the glycidyl ether compound include phenylglycidyl ethane, o-phenyl glycidyl ethane, 1,4-bis (β, γ-epoxypropoxy) butane, and 1,6-bis (β, γ-). Epoxypropoxy) Hexane, 1,4-bis (β, γ-epoxypoxy) benzene, 1- (β, γ-epoxypropoxy) -2-ethoxyethane, 1- (β, γ-epoxypropoxy) -2- Butaneoxyethane, 2,2-bis- [р- (β, γ-epoxypropoxy) phenyl] propane and 2,2-bis- (4-hydroxyphenyl) propane and 2,2-bis- (4-hydroxyphenyl) ) Examples thereof include bisglycidyl polyether obtained by the reaction of bisphenol such as methane and epichlorohydrin, and these can be used alone or in combination of two or more.

As the oxazoline group-containing compound, a bisoxazoline compound or the like is preferable. Specifically, for example, 2,2'-bis (2-oxazoline), 2,2'-bis (4-methyl-2-oxazoline), 2,2'-bis (4,4-dimethyl-2-). Oxazoline), 2,2'-bis (4-ethyl-2-oxazoline), 2,2'-bis (4,4'-diethyl-2-oxazoline), 2,2'-bis (4-propyl-2) -Oxazoline), 2,2'-bis (4-butyl-2-oxazoline), 2,2'-bis (4-hexyl-2-oxazoline), 2,2'-bis (4-phenyl-2-oxazoline) ), 2,2'-bis (4-cyclohexazoline), 2,2'-bis (4-benzyl-2-oxazoline), 2,2'-p-phenylenebis (2-oxazoline), 2 , 2'-m-phenylenebis (2-oxazoline), 2,2'-o-phenylenebis (2-oxazoline), 2,2'-p-phenylenebis (4-methyl-2-oxazoline), 2, 2'-p-phenylenebis (4,4-dimethyl-2-oxazoline), 2,2'-m-phenylenebis (4-methyl-2-oxazoline), 2,2'-m-phenylenebis (4, 4-Dimethyl-2-oxazoline), 2,2'-ethylenebis (2-oxazoline), 2,2'-tetramethylenebis (2-oxazoline), 2,2'-hexamethylenebis (2-oxazoline), 2,2'-octamethylenebis (2-oxazoline), 2,2'-decamethylenebis (2-oxazoline), 2,2'-ethylenebis (4-methyl-2-oxazoline), 2,2'- Tetramethylenebis (4,4-dimethyl-2-oxazoline), 2,2'-9,9'-diphenoxyetambis (2-oxazoline), 2,2'-cyclohexazoline (2-oxazoline), 2 , 2'-Diphenylene bis (2-oxazoline) and the like can be exemplified, and among these, 2,2'-bis (2-oxazoline) is most preferable from the viewpoint of reactivity with polyester. In addition, these can be used alone or in combination of two or more.

As these hydrolysis inhibitors (B), those having low volatility are preferable, and those having a high number average molecular weight are preferable, and usually 300 to 10,000, preferably 1,000 to 5,000. Use.
Further, as the hydrolysis inhibitor (B), it is preferable to use one having a high weight average molecular weight from the 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 even more preferably 3,000 or more. The upper limit of the weight average molecular weight is usually 50,000.
If the weight average molecular weight of the hydrolysis inhibitor (B) is too small, the hydrolysis resistance tends to decrease. If 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, and the carbodiimide equivalent at that time is preferably 50 to 10,000, particularly 100 to 1,000, and further 150. It is preferably ~ 500. The carbodiimide equivalent indicates the chemical formula amount 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, based on 100 parts by weight of the polyester resin (A). , More preferably 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 it is too small, sufficient durability tends to be difficult to obtain.

Further, 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 the molar ratio ((b) / (a)) of the total number of moles (b) of the functional groups of the hydrolysis inhibitor (B) in the pressure-sensitive adhesive composition to the total number of moles (a) of the acidic functional groups. , 0.5 ≦ (b) / (a), particularly preferably 1 ≦ (b) / (a) ≦ 1,000, and more preferably 1.5 ≦ (b) / (a) ≦ It is 100.
If the molar ratio of (b) to (a) is too low, the moist heat resistance performance tends to decrease. If the molar ratio of (b) to (a) is too high, the compatibility with the polyester resin (A) tends to decrease, and the adhesive strength, cohesive force, and durability performance tend to decrease.

<Urethane catalyst (C)>
The pressure-sensitive adhesive composition of the present invention contains the polyester-based resin (A), preferably contains the hydrolysis inhibitor (B), but the urethanization catalyst (C) is used from the viewpoint of reaction rate. It is more preferable to contain it.

Examples of the urethanization catalyst (C) include organometallic compounds and tertiary amine compounds. These can be used alone or in combination of two or more.

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

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

Among these urethanization catalysts (C), organometallic compounds are preferable, and zirconium-based compounds are particularly preferable, in terms of reaction rate and pot life of the pressure-sensitive adhesive layer. Further, it is preferable that acetylacetone is used in combination with the urethanization catalyst (C) as a catalytic action inhibitor. A catalytic system containing acetylacetone is preferable in that it suppresses catalytic action at low temperatures and prolongs pot life.

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

Examples of the cross-linking agent (D) include 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), such as a polyisocyanate compound and a polyepoxy compound. Among these, it is particularly preferable to use a polyisocyanate compound from the viewpoint of achieving both initial adhesiveness, 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, hydride diphenylmethane diisocyanate, xylylene diisocyanate, hydride xylylene diisocyanate, tetramethylxylylene diisocyanate, 1 , 5-Naphthalenediocyanate, triphenylmethane triisocyanate, and other polyisocyanates, as well as adducts of the above polyisocyanates and polyol compounds such as trimethylolpropane, and burettes and isocyanates of these polyisocyanate compounds. Nurate form, etc. can be mentioned. The polyisocyanate compound may be used even if the isocyanate portion is blocked with phenol, lactam or the like. One of these cross-linking agents (D) may be used alone, or two or more thereof may be mixed and used.

The content of the cross-linking agent (D) can be appropriately selected depending on the molecular weight of the polyester-based resin (A) and the purpose of use, but is usually one equivalent of at least one of the hydroxyl groups and carboxyl groups contained in the polyester-based resin (A). On the other hand, it is preferable that the reactive group contained in the cross-linking agent (D) contains the cross-linking agent (D) at a ratio of 0.2 to 10 equivalents, particularly preferably 0.5 to 5 equivalents, and further. It is preferably 0.5 to 3 equivalents.
If the equivalent number of the reactive groups contained in the cross-linking agent (D) is too small, the cohesive force tends to decrease, and if it is too large, the flexibility tends to decrease.

Further, in the reaction between the polyester resin (A) and the cross-linking agent (D), an organic solvent having no functional group that reacts with these components (A) and (D), for example, esters such as ethyl acetate and butyl acetate , Acetants such as methyl ethyl ketone and methyl isobutyl ketone, and organic solvents such as 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 above-mentioned polyester resin (A), hydrolysis inhibitor (B), urethanization catalyst (C), and cross-linking agent (D), the effects of the present invention can be obtained. Additives such as antioxidants (E) such as hindered phenols, softeners, ultraviolet absorbers, stabilizers, antistatic agents, tackifiers, and other inorganic or organic fillers, as long as they are not impaired. Additives such as metal powders, powders such as pigments, and particles can be blended. These can be used alone or in combination of two or more.

Further, the polyester-based pressure-sensitive adhesive according to the present invention (hereinafter, may be abbreviated as "sticking agent") is made of the above-mentioned pressure-sensitive adhesive composition, that is, the pressure-sensitive adhesive composition is cured.

Further, the pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet having an pressure-sensitive adhesive layer on one or both sides of a supporting base material, or a base-less pressure-sensitive adhesive sheet. Suitable as a sheet.
In the present invention, the term "sheet" is described as including "film" and "tape".

<Adhesive sheet>
The adhesive sheet can be produced, for example, as follows.
As a method for producing such an adhesive sheet, it can be produced according to a known general method for producing an adhesive sheet. For example, the pressure-sensitive adhesive composition is applied onto a base material, dried, and the pressure-sensitive adhesive composition on the opposite side is applied. A release sheet (or release film) is attached to the surface of the material layer and cured if necessary to obtain the pressure-sensitive adhesive sheet of the present invention having the pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive composition on the substrate.

Further, the pressure-sensitive adhesive sheet of the present invention can also be obtained by applying the above-mentioned pressure-sensitive adhesive composition on a release sheet, drying it, attaching a base material to the pressure-sensitive adhesive composition layer surface on the opposite side, and curing it if necessary. Be done.

Further, a base material-less double-sided adhesive sheet can be manufactured by forming an adhesive layer on the release sheet and attaching the release sheet to the adhesive layer surface on the opposite side.

When the obtained pressure-sensitive adhesive sheet or base-less double-sided pressure-sensitive adhesive sheet is used, the release sheet is peeled off from the pressure-sensitive adhesive layer and the pressure-sensitive adhesive layer and the adherend are bonded together.

Examples of the base material include polyester resins such as polyethylene naphthalate, polyethylene terephthalate, ribobutylene terephthalate, and polyethylene terephthalate / isophthalate copolymers; polyolefin resins such as polyethylene, polypropylene, and polymethylpentene; Polyfluorinated ethylene resins such as vinylidene polyfluoride and ethylene polyfluoride; polyamides such as nylon 6, nylon 6 and 6; polyvinyl chloride, polyvinyl chloride / vinyl acetate copolymers, ethylene-vinyl acetate copolymers, ethylene-vinyl Alcohol copolymers, vinyl polymers such as polyvinyl alcohol and vinylon; cellulose resins such as cellulose triacetate and cellophane; acrylic resins such as methyl polymethacrylate, ethyl polymethacrylate, ethyl polyacrylate and butyl polyacrylate. Polystyrene; Polycarbonate; Polyallylate; Polyimide; Sheet made of at least one synthetic resin selected from the group consisting of cycloolefin polymers, etc .; Metal foils of aluminum, copper, iron; Paper such as high-quality paper, glassin paper; Glass; Examples thereof include woven fabrics and non-woven fabrics made of fibers, natural fibers, synthetic fibers and the like. These base materials can be used as a single layer or as a multi-layer in which two or more kinds are laminated.

Among these, a base material made of polyethylene terephthalate or polyimide is particularly preferable, polyethylene terephthalate is particularly preferable in terms of excellent adhesiveness to an adhesive, and polyethylene terephthalate having a metal thin film layer is a base material. It is preferable because it has excellent adhesive strength between the adhesive and the adhesive, and the base material can be stably maintained without corroding the metal thin film layer, and the effect as the adhesive of the present invention can be remarkably exhibited.

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

Further, as the base material, a foam base material, for example, a foam sheet made of a foam of a synthetic resin such as polyurethane foam, polyethylene foam, or polyacrylate foam can be used. By using the foam sheet, the flexibility is excellent, and the followability to the adherend and the adhesive strength are improved. Among these, polyacrylate foam is preferable because it has an excellent balance of followability to an adherend and adhesive strength.

[Filler]
Further, the foam sheet may contain a filler. By including the filler in the foam sheet, the shear strength can be increased. This makes it possible to improve the resistance (peeling strength) against peeling the adhesive sheet from the adherend. Further, by using the filler, it is possible to suppress excessive deformation of the foam sheet and preferably adjust the balance between the flexibility and the cohesiveness of the adhesive sheet as a whole.

As the filler, various particulate matter can be used. Examples of the constituent material of the particulate matter include 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. , Nitridees such as silicon nitride and boron nitride; Inorganic materials such as calcium carbide, calcium carbonate, aluminum hydroxide, glass and silica; polystyrene, acrylic resin (eg polymethylmethacrylate), phenolic resin, benzoguanamine resin, urea resin, silicone Examples thereof include resins, nylons, polyesters, polyurethanes, polyethylenes, polypropylenes, polyamides, polyimides, silicones, 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 alone or in combination of two or more.

Further, the outer shape and 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 indefinite shape. Examples of the particle structure of the particulate matter include a dense structure, a porous structure, and a hollow structure.
Among them, the foam sheet preferably contains a particulate matter having a hollow structure (hereinafter, also referred to as “hollow particles”) as the filler, and more preferably contains 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 porcelain hollow balloons such as hollow ceramic balloons.

Examples of the hollow glass balloon include the trade name "Glass Micro Balloon", "Fuji Balloon H-40", "Fuji Balloon H-35" manufactured by Fuji Silicia Chemical Co., Ltd., and the trade name "Cellstar Z-20" manufactured by Tokai Kogyo Co., Ltd. , "Cellstar Z-27", "Cellstar CZ-31T", "Cellstar Z-36", "Cellstar Z-39", "Cellstar Z-39", "Cellstar T-36", "Cellstar PZ-6000" , Fine Balloon product name "Cylux Fine Balloon", Potters Barottini product name "Q-CEL ™ 5020", "Q-CEL ™ 7014", "Sphericel ™" 110P8 ”,“ Superior ™ 25P45 ”,“ Spherel ™ 34P30 ”,“ Spherel ™ 60P18 ”, trade names“ Super Balloon BA-15 ”,“ Super Balloon 732C ”, etc. manufactured by Showa Kagaku Kogyo Co., Ltd. Commercially available products can be used.

The average particle size of the hollow particles is not particularly limited. The average particle size 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, preferably 30% or less, and more preferably 10% or less of the thickness of the foam sheet.

The specific gravity of the hollow particles is not particularly limited, but in consideration of uniform dispersibility, mechanical strength, etc., for example, it is usually 0.1 to 1.8 g / cm ³ , preferably 0.1 to 1.5 g / cm ³ , and so on. It is more preferably 0.1 to 0.5 g / cm ³ , and particularly preferably 0.2 to 0.5 g / cm ³ .
The amount of the hollow particles used is not particularly limited, and can be, for example, 1 to 70% by volume of the total volume of the foam sheet, preferably 5 to 50% by volume, and particularly preferably 10%. It is preferably about 40% by volume.

[Bubble]
The foam sheet may have air bubbles directly in addition to the case where the foam sheet has air bubbles due to the filler. By including air bubbles in the foam sheet, the cushioning property of the adhesive sheet can be improved and the flexibility can be increased. When the flexibility of the pressure-sensitive adhesive sheet is increased, the deformation of the pressure-sensitive adhesive sheet makes it easier to absorb irregularities and steps on the surface of the adherend, so that the pressure-sensitive adhesive surface can be better adhered to the surface of the adherend. When the adhesive surface adheres well to the surface of the adherend, it can advantageously contribute to the improvement of the peel strength against the low-polarity surface and other various surfaces.

Further, the improvement of the flexibility of the adhesive sheet can also contribute to the reduction of the repulsive force of the adhesive sheet. As a result, when the adhesive sheet is attached along the surface of the adherend having a curved surface or a step, or when the adherend to which the adhesive sheet is attached is deformed, the adhesive sheet is subjected to its own repulsive force. It is possible to effectively suppress the phenomenon of peeling (floating) from the surface of the adherend.

The foam sheet may contain both a filler (eg, hollow particles) as described above and air bubbles. An adhesive sheet containing such a foam sheet is preferable because it tends to have an excellent balance between flexibility and cohesive force.

The bubbles contained in the foam sheet may be closed cells, open cells, or a mixture of these. From the viewpoint of cushioning property, a foam sheet having a structure containing a large amount of closed cells is more preferable.

In the case of closed cells, the gas component contained in the bubbles (gas component forming bubbles, hereinafter may be referred to as "bubble forming gas") is not particularly limited, and for example, nitrogen, carbon dioxide, argon and the like are not used. In addition to active gas, various gas components such as air can be mentioned. Further, as the bubble-forming gas, when the polymerization reaction of the synthetic resin is carried out in a state where the bubble-forming gas is contained, it is preferable to use a gas that does not inhibit the reaction. From such a viewpoint and a viewpoint of cost, nitrogen can be preferably adopted as the bubble forming gas.

The shape of the bubbles is typically generally spherical, but is not limited to this. The average diameter of the bubbles (average cell diameter) 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, preferably 30% or less, and more preferably 10% or less of the thickness of the foam sheet.

The average cell diameter can be typically determined by a scanning electron microscope (SEM), and can be determined by arithmetically averaging the results of measuring the diameters of 10 or more bubbles. preferable. At this time, for bubbles having a non-spherical shape, the average pore diameter shall be obtained by converting them into spherical bubbles having the same volume.

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

The method for forming the foam sheet is not particularly limited, and a known method can be appropriately adopted. For example, (1) a synthetic resin composition in which a bubble-forming gas is mixed in advance (preferably a composition of a type that is cured by active energy rays such as ultraviolet rays to form a viscoelastic body) is cured to form a viscoelastic body containing bubbles. A method of forming a body layer, (2) a method of forming a bubble-containing viscoelastic body layer by forming bubbles from the foaming agent using a synthetic resin composition containing a foaming agent, and the like can be appropriately adopted. The foaming agent used is not particularly limited, and can be appropriately selected from known foaming agents. For example, a foaming agent such as a heat-expandable microsphere can be preferably used.

In the formation of the bubble-containing viscoelastic body layer by the method (1) above, the method for preparing the synthetic resin composition mixed with the bubble-forming gas is not particularly limited, and a known bubble mixing method can be used. For example, as an example of a bubble mixing device, a stator having a large number of fine teeth on a disk having a through hole in 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 introducing a composition before bubble mixing between the teeth on the stator and the teeth on the rotor in such a bubble mixing device and forming bubbles while rotating the rotor at high speed. Is introduced through the through hole. As a result, a synthetic resin composition in which bubbles are finely dispersed and mixed is obtained.

The bubble-containing viscoelastic body layer can be formed by applying the synthetic resin composition mixed with the bubble-forming gas on a predetermined surface and curing the composition. As the curing method, a method of heating, a method of irradiating with active energy rays (for example, ultraviolet rays), or the like can be preferably adopted. The foam sheet can be suitably formed by heating or irradiating the synthetic resin composition mixed with the bubble-forming gas with active energy rays or the like to cure the synthetic resin composition while stably holding the bubbles.

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 a surfactant include an ionic surfactant, a hydrocarbon-based surfactant, a silicone-based surfactant, a fluorine-based surfactant, and the like. Of these, a fluorine-based surfactant is preferable, and a fluorine-based surfactant having an oxyalkylene group (typically, an oxyalkylene group having 2 to 3 carbon atoms) and a fluorinated hydrocarbon group in the molecule is particularly preferable. The fluorine-based surfactant may be used alone or in combination of two or more. As a commercially available product of a preferable fluorine-based surfactant, for example, the trade name "Surflon S-393" manufactured by AGC Seimi Chemical Co., Ltd. can be mentioned.
The amount of the surfactant used is not particularly limited, and is usually about 0.01 to 3 parts by weight based on the solid content with respect to 100 parts by weight of the synthetic resin contained in the foam sheet.

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

The thickness of the base material is, for example, preferably 1 to 1,000 μm, particularly preferably 2 to 500 μm, and even more preferably 3 to 300 μm.

As the release sheet, for example, a sheet, paper, cloth, non-woven fabric or the like made of various synthetic resins exemplified in the above-mentioned base material can be used after being released. As the release sheet, it is preferable to use a silicon-based release sheet.

As a method for 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 the conditions of the curing treatment, the temperature is usually room temperature (23 ° C.) to 70 ° C., and the time is usually 1 to 30 days. Specifically, for example, 23 ° C. for 1 to 20 days, preferably 23 ° C. for 3 days. It may be carried out under conditions such as to 14 days and 1 to 10 days at 40 ° C.

As the drying conditions, 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, particularly preferably 1 to 5 minutes.

The thickness of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet and the base-less double-sided pressure-sensitive adhesive sheet is preferably 2 to 500 μm, particularly preferably 5 to 200 μm, and even more preferably 10 to 100 μm. If the thickness of the adhesive layer is too thin, the adhesive strength tends to decrease, and if it is too thick, it becomes difficult to apply the adhesive layer uniformly, and problems such as bubbles entering the coating film tend to occur. be. When considering shock absorption, it is preferably 50 μm or more.

The thickness of the pressure-sensitive adhesive layer is obtained by subtracting the measured value of the thickness of the constituent members other than the pressure-sensitive adhesive layer from the measured value of the thickness of the entire pressure-sensitive adhesive sheet using "ID-C112B" manufactured by Mitutoyo. ..

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 further preferably 20 to 90% by weight from the viewpoint of durability and adhesive strength. be. If the gel fraction is too low, the cohesive force tends to decrease and the durability tends to decrease. If the gel fraction is too high, the cohesive force tends to increase and the adhesive force tends to decrease.

The gel fraction is a measure of the degree of cross-linking, and is calculated by, for example, the following method. That is, a pressure-sensitive adhesive sheet (without a release sheet) in which a pressure-sensitive adhesive layer is formed on a polymer sheet (for example, PET film or the like) as a base material is wrapped with a 200-mesh SUS wire mesh and contained in toluene. The gel fraction is defined as the weight percentage of the insoluble adhesive component remaining in the wire mesh after immersion at 23 ° C. for 24 hours. However, the weight of the base material is deducted.

Further, the pressure-sensitive adhesive sheet may be protected by providing a release sheet on the outside of the pressure-sensitive adhesive layer, if necessary. Further, in the pressure-sensitive adhesive sheet in which the pressure-sensitive adhesive layer is formed on one side of the base material, the pressure-sensitive adhesive layer is utilized by performing a peeling treatment on the surface of the base material opposite to the pressure-sensitive adhesive layer. It is also possible to protect.

Further, the pressure-sensitive adhesive of the present invention can be used for bonding various members, and among them, it is preferably used as a pressure-sensitive adhesive for optical members used for bonding optical members, and comprises such a pressure-sensitive adhesive composition. The optical member with the pressure-sensitive adhesive layer can be obtained by laminating and forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive on the optical member.

Examples of such an optical member include an ITO electrode film, a transparent electrode film such as an inorganic conductive film such as polythiophene, an organic conductive film, a polarizing plate, a retardation plate, an elliptical polarizing plate, an optical compensation film, a brightness improving film, an electromagnetic wave shielding film, and the like. Examples thereof include an electromagnetic wave absorbing film and an AR (anti-reflection) film. Among these, an ITO electrode film is particularly preferable because it is effective when the optical member is a transparent electrode film and high adhesive strength can be obtained. The ITO electrode film is often formed of a thin film on a base material such as glass or PET, but in the present invention, it is possible to use a film in which the ITO electrode film is formed of a thin film on a PET base material. Especially preferable. It is also suitable for a light extraction film provided on the light emitting surface of a surface light emitting body of an organic EL element, or as a light diffusion sheet for a liquid crystal display.

It is preferable that the optical member with the pressure-sensitive adhesive layer is further provided with a release sheet on the surface opposite to the surface of the optical member of the pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer and the adherend are bonded together. As such a release sheet, it is preferable to use a silicon-based release sheet.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded. In the example, "part" and "%" mean the weight standard.
Further, regarding the measurement of the glass transition temperature of the polyester resin in the following examples, the measurement was performed according to the above-mentioned method.

<Manufacturing of polyester resin (A)>
The moles described in the following production examples indicate the molar ratio when the total amount of the polyvalent carboxylic acids (a1) is 100 mol%.

[Manufacturing of polyester resin (A-1)]
66.3 parts (20 mol%) of isophthalic acid (IPA) and sebacin as polyvalent carboxylic acids (a1) in a reaction can equipped with a heating device, a thermometer, a stirrer, a rectification tower, a nitrogen introduction tube and a 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 (1.4BG) (50 mol%), 4.0 parts (1.5 mol%) of trimethylolpropane (TMP), hydrogenated polybutadiene polyol as a hydrogenated polybutadiene structure-containing compound (a3) (manufactured by Nippon Soda Co., Ltd., "GI-1000" ) 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 carried out over 4 hours.
Then, 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-1).
The glass transition temperature of the obtained polyester resin (A-1) is -46.8 ° C., and the structural unit ratio derived from the finished component (hereinafter, may be abbreviated as "finished component ratio") is a polyhydric carboxylic acid (hereinafter, may be abbreviated as "finished component ratio"). 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 the structural unit derived from the hydrogenated polybutadiene structure-containing compound (a3) in the polyester resin (A-1) was 1.7% by weight.

[Manufacturing of polyester resin (A-2)]
In a reaction can equipped with a heating device, a thermometer, a stirrer, a rectification tower, a nitrogen introduction tube and a vacuum device, 64.6 parts (20 mol%) of isophthalic acid and 314 sebacic acid as polyvalent carboxylic acids (a1). 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%), 29.1 parts (1 mol%) of hydrogenated polybutadiene polyol (“GI-1000” manufactured by Nippon Soda Co., Ltd.) as the hydrogenated polybutadiene structure-containing compound (a3), zinc acetate as the catalyst 0. 05 parts were charged, the temperature was gradually raised to an internal temperature of 250 ° C., and the esterification reaction was carried out over 4 hours.
Then, 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-2).
The glass transition temperature of the obtained polyester resin (A-2) was −47.7 ° C., and the finished component ratio was 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 = 63.8 mol% / 33.7 mol% / 1.5 mol% / 1 mol%.
The content of the structural unit derived from the hydrogenated polybutadiene structure-containing compound (a3) in the polyester resin (A-2) was 5.5% by weight.

[Manufacturing of polyester resin (A-3)]
In a reaction can equipped with a heating device, a thermometer, a stirrer, a rectification tower, a nitrogen introduction tube and a vacuum device, 43.7 parts (20 mol%) of isophthalic acid and 212. Sebasic 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%), 157.7 parts (8 mol%) of hydrogenated polybutadiene polyol (“GI-1000” manufactured by Nippon Soda Co., Ltd.) as the hydrogenated polybutadiene structure-containing compound (a3), zinc acetate as the catalyst 0. 05 parts were charged, the temperature was gradually raised to an internal temperature of 250 ° C., and the esterification reaction was carried out over 4 hours.
Then, 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) was -47.5 ° C., and the finished component ratio was 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 the structural unit derived from the hydrogenated polybutadiene structure-containing compound (a3) in the polyester resin (A-3) was 32.3% by weight.

[Manufacturing of polyester resin (A-4)]
In a reaction can equipped with a heating device, a thermometer, a stirrer, a rectification tower, a nitrogen introduction tube and a vacuum device, 67.4 parts (20 mol%) of isophthalic acid and azeline acid (AZA) as polyvalent carboxylic acids (a1). ) 152.7 parts (40 mol%) and 164.1 parts (40 mol%) of sebacic acid, 211.2 parts (100 mol%) of neopentyl glycol as polyol (a2), 1,4-butanediol 91.4 Part (50 mol%), and 4.1 parts (1.5 mol%) of trimethylol propane, hydrogenated polybutadiene polyol (manufactured by Nippon Soda Co., Ltd., "GI-1000") as a hydrogenated polybutadiene structure-containing compound (a3) 9 .1 part (0.3 mol%) and 0.05 part 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 carried out over 4 hours.
Then, 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) was -45.7 ° C., and the finished component ratio was isophthalic acid / azelaic acid / sebacic acid = 20 mol% / 40 mol as polyvalent carboxylic acids (a1). % / 40 mol%, as polyol (a2) neopentyl glycol / 1,4-butanediol / trimethylolpropane / hydrogenated polybutadiene polyol = 64.5 mol% / 33.7 mol% / 1.5 mol% / 0 It was 0.3 mol%.
The content of the structural unit derived from the hydrogenated polybutadiene structure-containing compound (a3) in the polyester resin (A-4) was 1.7% by weight.

[Manufacturing of polyester resin (A-5)]
308.6 parts (100 mol%) of azelaic acid as polyvalent carboxylic acids (a1), polyol (a2) in a reaction can equipped with a heating device, a thermometer, a stirrer, a rectification tower, a nitrogen introduction tube and a vacuum device. As neopentyl glycol 163.9 parts (96 mol%), 1,4-butanediol 73.9 parts (50 mol%), and trimethylolpropane 4.4 parts (2 mol%), hydrogenated polybutadiene structure-containing compound. Add 49.2 parts (2 mol%) of hydrogenated polybutadiene polyol (manufactured by Nippon Soda Co., Ltd., "GI-1000") as (a3) and 0.05 parts of zinc acetate as a catalyst, and gradually raise the temperature to an internal temperature of 250 ° C. The esterification reaction was carried out over 4 hours.
Then, 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-5).
The glass transition temperature of the obtained polyester resin (A-5) was -59.4 ° C., and the finished component ratio was azelaic acid = 100 mol% as polyvalent carboxylic acids (a1) and 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 the structural unit derived from the hydrogenated polybutadiene structure-containing compound (a3) in the polyester resin (A-5) was 10.7% by weight.

[Manufacturing of polyester resin (A'-1)]
In a reaction can equipped with a heating device, a thermometer, a stirrer, a rectification tower, a nitrogen introduction tube and a vacuum device, 16.9 parts (20 mol%) of isophthalic acid and sebacic acid 82. 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%), 456.7 parts (60 mol%) of hydrogenated polybutadiene polyol (“GI-1000” manufactured by Nippon Soda Co., Ltd.) as the hydrogenated polybutadiene structure-containing compound (a3), zinc acetate as the catalyst 0. 02 parts were charged, the temperature was gradually raised to an internal temperature of 250 ° C., and the esterification reaction was carried out over 4 hours.
Then, 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) was -43.6 ° C., and the finished component ratio was isophthalic acid / sebacic acid = 20 mol% / 80 mol% as polyvalent carboxylic acids (a1). The polyol (a2) was neopentyl glycol / 1,4-butanediol / trimethylolpropane / hydrogenated polybutadiene polyol = 15.3 mol% / 22.7 mol% / 2 mol% / 60 mol%.
The content of the structural unit derived from the hydrogenated polybutadiene structure-containing compound (a3) in the polyester resin (A'-1) was 80% by weight.

[Manufacturing of polyester resin (A'-2)]
In a reaction can equipped with a heating device, a thermometer, a stirrer, a rectification tower, a nitrogen introduction tube and a vacuum device, 67.3 parts (20 mol%) of isophthalic acid and 327. 5 parts (80 mol%), 189.7 parts (90 mol%) of neopentyl glycol as polyol (a2), 91.2 parts (50 mol%) of 1,4-butanediol, 3.5 parts of trimethylolpropane (50 mol%) 1 mol%), 20.8 parts (9 mol%) of 1,6-hexanediol (1.6HG), 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.
Then, 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'-2).
The glass transition temperature of the obtained polyester resin (A'-2) was −48.5 ° C., and the finished component ratio was 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 polyol (a2) Met.
The content of the structural unit 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 unit derived from the finished component) and the glass transition temperature (Tg) of the obtained polyester resin (A) are also shown in Table 1 below.

<Manufacturing of polyester adhesive composition>
The polyester-based pressure-sensitive adhesive compositions of the following Examples and Comparative Examples were produced using each of the polyester-based resins obtained above, and the haze and solution transparency were evaluated according to the following evaluation criteria, and the gel fraction was determined by the above-mentioned method. The results are shown in Table 2.

(Example 1)
The polyester resin (A-1) obtained above is diluted with toluene to a solid content concentration of 50%, and hydrolysis is suppressed with respect to 200 parts (100 parts as solid content) of this polyester resin (A-1) solution. Agent (Nissin Spinning Chemical Co., Ltd., "Carbodilite V-09BG") 1 part (solid content), and trimethylolpropane / tolylene diisocyanate adduct (Tosoh Co., Ltd., "Coronate L55E") 3 parts (solid content) , 0.01 part (solid content) of a zirconium-based compound (manufactured by Matsumoto Fine Chemical Co., Ltd., "Organix ZC-150") diluted with acetylacetone to a solid content concentration of 1% as a urethanization catalyst, and stirred and mixed. 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)
In Example 1, the same as in Example 1 except that the polyester resin (A-1) was changed to the polyester resin (A'-2), the cross-linking agent was changed to 2 parts, and the toluene was changed to ethyl acetate. To obtain a polyester-based pressure-sensitive adhesive composition.

The obtained polyester-based pressure-sensitive adhesive composition was evaluated as follows, and the results are shown in Table 2 below.

<Making an adhesive sheet with a double-sided release film>
The polyester-based pressure-sensitive adhesive compositions obtained in Examples 1 to 5 and Comparative Examples 1 and 2 were used on a PET release film having a thickness of 38 μm (Mitsui Chemicals Tocello Co., Ltd., “SP-PET-03-BU”) (α). ) 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 the pressure-sensitive adhesive composition layer of 50 μm.
Next, the surface of the pressure-sensitive adhesive composition layer of the obtained pressure-sensitive adhesive sheet with a release film was subjected to a PET release film having a thickness of 38 μm, which was different from that of the release film (α) (manufactured by Mitsui Kagaku Tohcello Co., Ltd., “SP-”. It was covered with PET-01-BU ") (β) and aged at 40 ° C. for 4 days to obtain an adhesive sheet with a double-sided release film.

<Making an adhesive sheet with a single-sided release film>
The polyester-based pressure-sensitive adhesive compositions obtained in Examples 1 to 5 and Comparative Examples 1 and 2 were applied onto a PET film (manufactured by Toray Industries, Inc., "Lumirer T60") having a thickness of 38 μm using an applicator, and the temperature was 100 ° C. To obtain a pressure-sensitive adhesive sheet with a PET film having a thickness of the pressure-sensitive adhesive composition layer of 25 μm.
Next, the surface of the pressure-sensitive adhesive composition layer of the obtained pressure-sensitive adhesive sheet with PET film was covered with a PET release film (β) having a thickness of 38 μm, and aged at 40 ° C. for 4 days to obtain the pressure-sensitive adhesive sheet with a single-sided release film. Obtained.

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

[Haze]
Peel off the release film (β) on one side from the adhesive layer of the adhesive sheet with the double-sided release film obtained above, and attach the adhesive layer side to a non-alkali glass plate (Eagle XG, manufactured by Corning). After that, 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 adhesive layer was measured using HAZE MATER NDH2000 (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 ○ ・ ・ ・ Greater than 1.0% 5.0% or less × ・ ・ ・ Greater than 5.0%

[Solution transparency (compatibility)]
200 parts of polyester resin solution (100 parts as solid content) used in Examples 1 to 5 and Comparative Examples 1 and 2 and 1 part of a hydrolysis inhibitor (“Carbodilite V-09BG” manufactured by Nisshinbo Chemical Co., Ltd.) A compounding solution was prepared by blending only (solid content), and the change in appearance before and after the compounding was visually evaluated according to the following criteria.
(Evaluation criteria)
◎ ・ ・ ・ No change in appearance ○ ・ ・ ・ Light is transmitted but turbid × ・ ・ ・ Light is not transmitted and turbidity is large

From the results in Table 1 above, the polyester-based pressure-sensitive adhesive compositions of Examples 1 to 5 are excellent not only in adhesiveness to SUS-BA plates but also in adhesiveness to polyolefin substrates such as PP plates. Furthermore, the haze and solution transparency were also excellent.
On the other hand, Comparative Example 1 was excellent in adhesiveness but inferior in haze and solution transparency. Further, Comparative Example 2 was excellent in haze and solution transparency, but inferior in adhesiveness to a polyolefin substrate such as a PP plate.
Therefore, it can be seen that the examples are excellent polyester-based pressure-sensitive adhesive compositions that have both adhesiveness to a polyolefin substrate and haze and solution transparency.

Since the polyester-based pressure-sensitive adhesive composition of the present invention has excellent adhesiveness to a polyolefin base material, which is generally inferior in adhesiveness, and also has excellent haze and solution transparency, the pressure-sensitive adhesive and pressure-sensitive adhesive sheet using the same can be used. In an optical member such as a display, an optical film or a base material constituting the display, the optical member can be suitably used for bonding the optical member.

Claims (13)

A polyester-based pressure-sensitive adhesive composition containing a polyester-based resin (A) having a structural unit derived from the hydrogenated polybutadiene structure-containing compound (a3).
The content of the structural unit derived from the hydrogenated polybutadiene structure-containing compound (a3) is 0.01 to 20 % by weight with respect to the polyester resin (A), and the weight average molecular weight of the polyester resin (A) is A polyester-based pressure-sensitive adhesive composition having an acid value of 20,000 to 200,000 and an acid value of 3 mgKOH / g or less . The polyester resin (A) has a structural unit derived from the polyvalent carboxylic acids (a1) and a structural unit derived from the polyol (a2), and the hydrogenated polybutadiene structure-containing compound (a3) is contained in the polyol (a2). It is a hydrogenated polybutadiene polyol (a3-1), and is characterized in that the structural unit derived from the hydrogenated polybutadiene structure-containing compound (a3) is contained in the structural unit derived from the polyol (a2) in an amount of 0.001 to 10 mol%. The polyester-based pressure-sensitive adhesive composition according to claim 1. The polyester-based pressure-sensitive adhesive composition according to claim 2, wherein the polyvalent carboxylic acid (a1) contains an asymmetric aromatic polyvalent carboxylic acid (a1-1). The polyester-based pressure-sensitive adhesive composition according to claim 2 or 3, wherein the polyvalent carboxylic acid (a1) contains an aliphatic polyvalent carboxylic acid (a1-2) having an odd number of carbon atoms. The polyester-based pressure-sensitive adhesive composition according to any one of claims 2 to 4, wherein the polyol (a2) contains a branched structure-containing polyol (a2-1). The polyester-based pressure-sensitive adhesive composition according to any one of claims 2 to 5, wherein the polyol (a2) contains a linear polyol (a2-2). The polyester-based pressure-sensitive adhesive composition according to any one of claims 1 to 6, wherein the polyester-based resin (A) has a glass transition temperature of −80 to 20 ° C. 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 cross-linking agent (D). A polyester-based pressure-sensitive adhesive according to any one of claims 1 to 10, wherein the polyester-based pressure-sensitive adhesive composition is crosslinked. A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer containing the polyester-based pressure-sensitive adhesive according to claim 11. An optical member with a pressure-sensitive adhesive layer, which comprises a pressure-sensitive adhesive layer containing the polyester-based pressure-sensitive adhesive according to claim 11 and an optical member.