WO2015182369A1 - Pressure-sensitive adhesive composition, process for producing same, and pressure-sensitive adhesive layer and process for producing same - Google Patents

Abstract

A pressure-sensitive adhesive composition which comprises 100 parts by mass of (A) a hydrogenated block copolymer composition, 0.01-5 parts by mass of (B) a compound having a molecular weight of 2,000 or lower, and (C) a solvent which is an aliphatic hydrocarbon and/or aromatic hydrocarbon that is a liquid at 23°C, wherein the hydrogenated block copolymer composition (A) comprises (1) a product of hydrogenation of a block copolymer (a1) represented by the general formula (A-B)n and (2) a product of hydrogenation of a block copolymer (a2) represented by the general formula A-B-A or (A-B)m-X, and both the hydrogenated block copolymer composition (A) and the compound (B) have dissolved in the solvent (C).

Description

Adhesive composition and method for producing the same, and adhesive layer and method for producing the same

The present invention relates to a pressure-sensitive adhesive composition and a production method thereof, and a pressure-sensitive adhesive layer and a production method thereof.

The hydrogenated block copolymer is used as a component of the pressure-sensitive adhesive composition. The hydrogenated block copolymer is a hydrogenated product of a copolymer comprising a polymer block composed of monomer units derived from an aromatic vinyl compound and a polymer block B composed of monomer units derived from a conjugated diene compound. (For example, Patent Document 1).

This hydrogenated block copolymer is generally handled in the form of particles such as pellets, flakes or blocks. However, since the relatively soft hydrogenated block copolymer used in the pressure-sensitive adhesive has strong self-adhesiveness (self-blocking property), the surface of the particle is blocked with an anti-blocking agent such as talc or organic polymer particles. By covering, measures are taken to prevent self-adhesion (blocking) of the particles.

JP-A-5-295056

However, when forming a pressure-sensitive adhesive layer using a pressure-sensitive adhesive composition containing a mixture of such an antiblocking agent and a hydrogenated block copolymer, when the pressure-sensitive adhesive composition is dissolved in a solvent, Since the antiblocking agent does not dissolve in the solvent, dullness may occur in the pressure-sensitive adhesive layer obtained using the solution or the pressure-sensitive adhesive composition. In this case, it is unsuitable for applications requiring transparency.

Moreover, the occurrence of dullness may occur remarkably when the pressure-sensitive adhesive composition or the pressure-sensitive adhesive layer is exposed to a high-temperature and high-humidity environment. For example, even if a slight dullness occurs when the pressure-sensitive adhesive composition or the pressure-sensitive adhesive layer is dissolved in a solvent at room temperature, the pressure-sensitive adhesive composition or the pressure-sensitive adhesive layer may be formed in a high-temperature and high-humidity environment. It may be dull that cannot be overlooked.

The present inventors diligently studied the composition of the pressure-sensitive adhesive composition containing the hydrogenated block copolymer, and found that the pressure-sensitive adhesive composition containing a specific material and the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition are high. It has been found that it has transparency and moist heat whitening resistance, and can impart excellent adhesion and step following ability by the additive components described later.

The present invention provides a pressure-sensitive adhesive composition capable of obtaining a pressure-sensitive adhesive layer having high transparency and excellent moisture and heat whitening resistance, a method for producing the same, and a pressure-sensitive adhesive layer and a method for producing the same. .

1. The pressure-sensitive adhesive composition according to one aspect of the present invention is
(A) 100 parts by mass of a hydrogenated block copolymer composition;
(B) 0.01 to 5 parts by mass of a compound having a molecular weight of 2,000 or less;
(C) a pressure-sensitive adhesive composition comprising an aliphatic hydrocarbon and / or a solvent that is an aromatic hydrocarbon that is liquid at 23 ° C.,
The (A) hydrogenated block copolymer composition comprises the hydrogenated product (1) of the block copolymer (a1) represented by the general formula (AB) n and the general formula ABAA or ( AB) Hydrogenated product of block copolymer (a2) represented by mX (2) (in the above formula, A is the same or different and consists of a monomer unit derived from an aromatic vinyl compound) Represents polymer block A, B is the same or different and represents polymer block B composed of monomer units derived from a conjugated diene compound, n represents an integer of 1 to 3, and m represents an integer of 1 or more And X represents a coupling agent residue.)
The (A) hydrogenated block copolymer composition and the (B) compound are both dissolved in the (C) solvent.

2. 2. The pressure-sensitive adhesive composition according to 1 above, further comprising (D) 5 parts by mass or more and 80 parts by mass or less of the first compatibilizer, wherein the (D) first compatibilizer is compatible with the polymer block A. And has a softening point of 80 ° C. or higher and can be dissolved in the solvent (C).

3. In the pressure-sensitive adhesive composition according to the above 1 or 2, further comprising (E) 10 parts by mass or more and 150 parts by mass or less of the second compatibilizer,
The (E) second compatibilizer is compatible with the polymer block B, is liquid at 23 ° C., and can be dissolved in the (C) solvent.

4. 4. The pressure-sensitive adhesive composition according to any one of 1 to 3 above, wherein the block (a1) hydrogenated product (1) and the block copolymer constituting the (A) hydrogenated block copolymer composition are combined with the block copolymer. The mass ratio of the polymer (a2) to the hydrogenated product (2) can be 90:10 to 10:90.

5. 5. The pressure-sensitive adhesive composition according to any one of 1 to 4, wherein the compound (B) is at least one selected from the group consisting of an ultraviolet absorber, a light stabilizer, an antioxidant and a metal deactivator. Can be.

6. In the pressure-sensitive adhesive composition according to any one of 1 to 5, the (D) first compatibilizer may be an aromatic tackifying resin.

7. 7. The pressure-sensitive adhesive composition according to 6 above, wherein the aromatic tackifying resin is an aromatic petroleum resin, a styrene polymer, an α-methylstyrene polymer, or a styrene- (α-methylstyrene) copolymer. At least one selected from the group consisting of styrene-aliphatic hydrocarbon copolymers, styrene- (α-methylstyrene) -aliphatic hydrocarbon copolymers, and styrene-aromatic hydrocarbon copolymers Can be.

8. 8. The pressure-sensitive adhesive composition according to any one of 1 to 7, wherein the (E) second compatibilizer is at least one selected from the group consisting of a polybutene compound, a polyisobutylene compound, and a polyisoprene compound. Can be.

9. 9. The pressure-sensitive adhesive composition according to any one of 1 to 8 above, wherein the total content of the (D) first compatibilizer and the (E) second compatibilizer is (A) hydrogenated block co-polymer. It can be 20 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the combined composition.

10. The manufacturing method of the adhesive composition which concerns on 1 aspect of this invention is a manufacturing method of the adhesive composition in any one of said 1 thru | or 9, Comprising: Said (A) hydrogenated block copolymer composition 100 A pellet of a hydrogenated block copolymer composition containing 0.01 part by mass or more and 5 parts by mass or less of the compound (B) with respect to part by mass, wherein the compound (B) is present inside and on the surface of the pellet. A step of dissolving the hydrogenated block copolymer composition pellets in the solvent (C).

11. The manufacturing method of the adhesive layer which concerns on 1 aspect of this invention is the process of apply | coating the adhesive composition in any one of said 1 thru | or 9 on a base material, and obtaining a film | membrane, and drying the said film | membrane. And (C) removing the solvent to obtain a pressure-sensitive adhesive layer.

12 The pressure-sensitive adhesive layer according to one embodiment of the present invention is
(A) 100 parts by mass of a hydrogenated block copolymer composition;
(B) A pressure-sensitive adhesive layer containing 0.01 to 5 parts by mass of a compound having a molecular weight of 2,000 or less,
The (A) hydrogenated block copolymer composition comprises the hydrogenated product (1) of the block copolymer (a1) represented by the general formula (AB) n and the general formula ABAA or ( AB) Hydrogenated product of block copolymer (a2) represented by mX (2) (in the above formula, A is the same or different and consists of a monomer unit derived from an aromatic vinyl compound) Represents polymer block A, B is the same or different and represents polymer block B composed of monomer units derived from a conjugated diene compound, n represents an integer of 1 to 3, and m represents an integer of 1 or more And X represents a coupling agent residue.)
The (A) hydrogenated block copolymer composition and the compound (B) are both dissolved in (C) a solvent that is an aliphatic hydrocarbon and / or an aromatic hydrocarbon that is liquid at 23 ° C. Has properties.

13. The pressure-sensitive adhesive layer according to the above 12, can be obtained by removing the solvent (C) from the pressure-sensitive adhesive composition according to any one of the above 1 to 9.

10. The pressure-sensitive adhesive composition according to any one of 1 to 9 above, (A) 100 parts by mass of the hydrogenated block copolymer composition, and (B) 0.01 mass of a compound having a molecular weight of 2,000 or less. And (C) a hydrogenated block copolymer containing (C) a solvent that is an aliphatic hydrocarbon and / or an aromatic hydrocarbon that is liquid at 23 ° C. Since both the composition and the compound (B) are dissolved in the solvent (C), the composition is excellent in transparency. For this reason, after forming into a film using this adhesive composition, in the adhesive layer obtained by removing the said (C) solvent, it is excellent in the solubility of the said (B) compound, and this (B) compound Is difficult to precipitate. Thereby, the pressure-sensitive adhesive layer has high transparency and is excellent in moisture and heat whitening resistance. Moreover, the outstanding adhesiveness and level | step difference followable | trackability can be provided to this adhesive layer with the below-mentioned additive component.

Moreover, according to the manufacturing method of the adhesive composition of said 10, including the process of dissolving said (A) hydrogenated block copolymer composition pellet in said (C) solvent, said (A) Since the hydrogenated block copolymer composition and the compound (B) can be dissolved in the solvent (C), a pressure-sensitive adhesive composition excellent in transparency can be obtained, followed by a pressure-sensitive adhesive composition. Even in the filtration process that is generally performed in the manufacturing process, and in the microfiltration process for optical applications that require more transparency, a smooth filtration operation is possible without causing clogging of the filtration device. .

According to the method for producing a pressure-sensitive adhesive layer described in 11 above, a process of applying a pressure-sensitive adhesive composition according to any one of 1 to 9 on a substrate to obtain a film, and drying the film And (C) removing the solvent to obtain a pressure-sensitive adhesive layer, thereby providing a pressure-sensitive adhesive layer that is excellent in solubility of the compound (B) and in which the compound (B) is difficult to precipitate. Therefore, it is possible to obtain a pressure-sensitive adhesive layer excellent in transparency and moisture and heat whitening resistance.

In the pressure-sensitive adhesive layer according to 12 or 13, the (A) hydrogenated block copolymer composition and the (B) compound are both (C) an aliphatic carbonization liquid at 23 ° C. By having the property of being dissolved in a solvent that is hydrogen and / or an aromatic hydrocarbon, it can be used, for example, in an environment that requires transparency and wet heat whitening resistance.

FIG. 1 is a cross-sectional view schematically showing a configuration of an input / output device (touch panel type input / output device) according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings. In the present invention, “parts” means “parts by mass” and “%” means “mass%” unless otherwise specified.

1. Pressure-sensitive adhesive composition The pressure-sensitive adhesive composition according to an embodiment of the present invention includes (A) a hydrogenated (hydrogenated) block copolymer composition (hereinafter simply referred to as “component (A)”). 100 parts by mass and (B) a compound having a molecular weight of 2,000 or less (hereinafter sometimes simply referred to as “component (B)”) 0.01 parts by mass or more and 5 parts by mass or less, (C) a solvent that is an aliphatic hydrocarbon and / or an aromatic hydrocarbon that is liquid at 23 ° C. (hereinafter sometimes simply referred to as “component (C)”).

In the pressure-sensitive adhesive composition according to this embodiment, the component (A) and the component (B) are both dissolved in the component (C). In the present invention, “the (A) component and the (B) component are both dissolved in the (C) component” means that the (A) component or the (B) component is solid as a pressure-sensitive adhesive composition. It means that no dullness or cloudiness is observed in the pressure-sensitive adhesive composition. Specifically, it does not cause clogging when filtered through a filter paper having an opening of 1 μm, and a residue on the filter paper. It means that there is no.

1.1. Component (A) The component (A) is a hydrogenated product of the block copolymer (a1) represented by the general formula (AB) n (hereinafter, simply referred to as “hydrogenated product (1)”). (1) and the hydrogenated product (2) of the block copolymer (a2) represented by the general formula ABA or (AB) mX (hereinafter simply referred to as “hydrogenated product ( 2) "(in the above formula, A is the same or different, and represents a polymer block A composed of monomer units derived from an aromatic vinyl compound, and B is the same or different, respectively). And represents a polymer block B composed of monomer units derived from a conjugated diene compound, n represents an integer of 1 to 3, m represents an integer of 1 or more, and X represents a coupling agent residue. It consists of.

In the general formula (AB) n, n can be 1, 2 or 3. In the general formula (AB) mX, m, which is an integer of 1 or more, is preferably 2 or more and 4 or less.

Hydrogenated product (1) and hydrogenated product (2) are thermoplastic elastomers. In the polymer block A composed of monomer units derived from an aromatic vinyl compound and constituting the hydrogenated product (1) and the hydrogenated product (2), the monomer unit derived from the aromatic vinyl compound is, for example, styrene, α-methyl styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, and p-tert-butyl styrene are preferable, and styrene and α-methyl styrene are more preferable (more preferably styrene). In the polymer block B consisting of monomer units derived from a conjugated diene compound and constituting the hydrogenated product (1) and the hydrogenated product (2), the monomer unit derived from a conjugated diene compound is, for example, butadiene, Isoprene or a mixture of butadiene and isoprene is preferable, and isoprene is more preferable. Examples of the coupling agent residue in the general formula (AB) mX include divinylbenzene; polyvalent epoxy compounds such as epoxidized 1,2-polybutadiene and epoxidized soybean oil; dimethyldichlorosilane, tri Halogen compounds such as chlorosilane, methyltrichlorosilane, and tetrachlorosilane; ester compounds such as methyl benzoate, ethyl benzoate, diethyl phthalate, dimethyl isophthalate, and dimethyl terephthalate; carbonate compounds such as dimethyl carbonate; dimethyldimethoxysilane, methyl Examples include coupling agent residues derived from known coupling agents such as alkoxysilane compounds such as trimethoxysilane, methyltriethoxysilane, tetramethoxysilane, and tetraethoxysilane.

In the pressure-sensitive adhesive composition according to this embodiment, the mass ratio of the hydrogenated product (1) and the hydrogenated product (2) in the component (A) is that the adjustment of the viscoelasticity of the obtained pressure-sensitive adhesive layer is easy. Is preferably 90:10 to 10:90, more preferably 80:20 to 20:80, and still more preferably 70:30 to 30:70 (here, component (A) 100) In the case of mass%, the total amount of the hydrogenated product (1) and the hydrogenated product (2) is 100% by mass.) The hydrogenated additive (1) and the hydrogenated additive (2) The mass ratio can be determined from an elution curve obtained by gel permeation chromatography (GPC) measurement.

The content of the polymer block A contained in the hydrogenated product (1) and the content of the polymer block A contained in the hydrogenated product (2) in that durability can be imparted to the pressure-sensitive adhesive composition according to this embodiment. The amount can be 3% by mass or more and 40% by mass or less of the hydrogenated product (1) or the hydrogenated product (2), respectively, preferably 5% by mass or more and 30% by mass or less, and more preferably 10% by mass or more. More preferably, it is 20 mass% or less. The content of block A can be determined from the measured value measured by a ¹ H-NMR spectrum or the like.

The content of the polymer block B contained in the hydrogenated product (1) and the hydrogenated product (2) is such that the hydrogenated product can be imparted with a step following property to the pressure-sensitive adhesive composition according to the present embodiment. (1) or the hydrogenated product (2) may be 60% by mass to 97% by mass, more preferably 70% by mass to 95% by mass, and more preferably 80% by mass to 90% by mass. More preferably. The content of the block B can be determined from the measured value measured by a ¹ H-NMR spectrum or the like.

The hydrogenated product (1) and the hydrogenated product (2) are carbon-carbon double bonds derived from the conjugated diene compound in the polymer block B in that weather resistance can be imparted to the pressure-sensitive adhesive composition according to this embodiment. The hydrogenation rate is preferably 50% by weight or more (and 100% by weight or less), more preferably 80% by weight or more. The hydrogenation rate can be determined from the measured values measured by ¹ H-NMR spectrum before and after hydrogenation.

In the present invention, the hydrogenation rate of the carbon-carbon double bond derived from the conjugated diene compound in the polymer block B means that the carbon-carbon double bond derived from the conjugated diene compound is saturated by hydrogenation. Say percentage.

The weight average molecular weight of the hydrogenated product (1) is preferably 10,000 or more and 300,000 or less, and preferably 20,000 or more, from the viewpoint that the pressure-sensitive adhesive composition according to the present embodiment can impart more excellent step following ability. More preferably, it is more preferably 30,000 or more, more preferably 250,000 or less, and further preferably 200,000 or less.

The weight average molecular weight of the hydrogenated product (2) is preferably 50,000 or more and 500,000 or less, more preferably 80,000 or more, from the viewpoint that durability can be imparted to the pressure-sensitive adhesive composition according to this embodiment. More preferably, it is 100,000 or more, more preferably 400,000 or less, and further preferably 300,000 or less. In addition, the weight average molecular weight said here means the weight average molecular weight of polystyrene conversion calculated | required by the gel permeation chromatography (GPC) measurement.

Examples of the hydrogenated product (1) include a hydrogenated product of a diblock copolymer of styrene and isoprene (SEP), a hydrogenated product of a diblock copolymer of styrene and butadiene (SEB), and styrene and butadiene / isoprene. And hydrogenated products (SEEP) of diblock copolymers. These may be used singly or in combination of two or more.

Examples of the hydrogenated product (2) include a hydrogenated product of a styrene, isoprene and styrene triblock copolymer (SEPS), a hydrogenated product of a styrene, butadiene and styrene triblock copolymer (SEBS), and styrene. And a hydrogenated product (SEEPS) of a triblock copolymer of butadiene / isoprene and styrene. These may be used singly or in combination of two or more.

1.2. (B) Component (B) The compound whose molecular weight is 2,000 or less is the transparency of the adhesive layer obtained using the adhesive composition which concerns on this embodiment, adhesiveness, and heat-and-heat-whitening resistance. Contribute.

The component (B) can be an inorganic compound or an organic compound, and is preferably an organic compound in terms of excellent solubility in the component (C). Furthermore, from the viewpoint of solubility in the component (C), the component (B) is preferably a compound containing no inorganic salt or organic salt.

Specific examples of the component (B) include ultraviolet absorbers (for example, tinuvin 326 (molecular weight 316), tinuvin 329 (molecular weight 323)), light stabilizers (for example, ADK STAB LA-77 (MW 481), ADK STAB LA-52 (Molecular weight 847)), antioxidants (for example, BHT (molecular weight 220), ADK STAB AO-330 (molecular weight 775), ADK STAB AO-60 (molecular weight 1178), Irganox 1076 (molecular weight 531), etc., metal deactivators (For example, at least one selected from the group consisting of benzotriazole (molecular weight 119)). As the component (B), one type may be used alone, or two or more types may be used in combination.

The content of the component (B) in the pressure-sensitive adhesive composition according to this embodiment is 0.01 with respect to 100 parts by mass of the component (A) in that the transparency of the pressure-sensitive adhesive composition according to this embodiment can be ensured. It is preferably no less than 5 parts by mass and no greater than 5 parts by mass, preferably no less than 0.2 parts by mass and no greater than 3 parts by mass, and more preferably no less than 0.25 parts by mass and no greater than 2.5 parts by mass.

From the viewpoint of excellent solubility in the component (C), the molecular weight of the component (B) is preferably 1,800 or less, more preferably 1,500 or less, and usually 100 or more. In addition, when (B) component is a high molecular compound, the molecular weight of (B) component means a weight average molecular weight (Mw).

When the molecular weight of the component (B) exceeds 2,000, the component (B) is likely to precipitate in the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition. As a result, the adhesive strength of the pressure-sensitive adhesive layer may be reduced. Moreover, transparency of this adhesive layer may fall by precipitation of (B) component. Furthermore, even if the pressure-sensitive adhesive layer is transparent at room temperature, when the pressure-sensitive adhesive layer is exposed under high temperature and high humidity conditions, it tends to precipitate due to the size of the molecular weight, and is inferior in moisture and heat whitening resistance. There is.

Also, it is preferable that the component (B) is solid at room temperature in that it can be supported on the hydrogenated block copolymer composition (A) pellets and blocking can be suppressed.

The average particle size of the component (B) is preferably 50 μm or less, usually 0.01 μm or more, more preferably 30 μm or less, and further preferably 20 μm or less. In the present invention, fine powder particles can be classified, or pellet and granule particles can be pulverized and used as a desired particle size. In addition, the average particle diameter of particle | grains can be measured with an electron microscope, for example, can be measured by the method as described in this-application Example mentioned later.

1.3. Component (C) The solvent which is an aliphatic hydrocarbon and / or an aromatic hydrocarbon which is liquid at 23 ° C. as the component (C) has a property of dissolving the component (A) and the component (B). Have.

Examples of the aliphatic hydrocarbon that can be used as the component (C) include linear chains such as n-pentane, methylpentane, n-hexane, isohexane, n-heptane, n-heptane, isoheptane, n-octane, and isooctane. Alternatively, branched aliphatic hydrocarbons, cyclic aliphatic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclohexane are exemplified.

In addition, examples of the aromatic hydrocarbon that can be used as the component (C) include toluene, benzene, o-xylene, m-xylene, p-xylene, ethylbenzene, mesitylene, chlorobenzene, and nitrobenzene. As the component (C), one or two of aliphatic hydrocarbons and aromatic hydrocarbons can be used in combination.

In the pressure-sensitive adhesive composition according to this embodiment, (A) component and (B) component can be dissolved, and a coating operation is performed when forming a pressure-sensitive adhesive layer from the pressure-sensitive adhesive composition according to this embodiment. In view of improving the property, the content of the component (C) in the pressure-sensitive adhesive composition according to this embodiment is 100 parts by mass or more and 1,000 parts by mass or less with respect to 100 parts by mass of the component (A). It is more preferable that it is 200 parts by mass or more and 600 parts by mass or less.

1.4. (D) First compatibilizer The first compatibilizer (hereinafter sometimes simply referred to as “component (D)”) is the block copolymer (a1) or block copolymer constituting component (A). It has a property compatible with the polymer block A contained in the polymer (a2), has a softening point of 80 ° C. or higher, and is dissolved in the component (C).

In the present invention, “the (D) component is dissolved in the (C) component” means that the (D) component is not visually confirmed in the pressure-sensitive adhesive composition according to this embodiment. It means that no cloudiness is observed. Specifically, it means that no clogging occurs when filtering with a filter paper having an opening of 1 μm, and there is no residue on the filter paper.

In the present invention, “compatible” or “compatibilizing” means that turbidity or phase separation is not visually confirmed in a mixture obtained by mixing two different components. .

Here, whether or not the component (D) is compatible with the polymer block A depends on the component corresponding to the polymer block A, that is, hydrogenation of a polymer synthesized only from an aromatic vinyl monomer. Evaluation will be made using the product and the component (D).

More specifically, the occurrence of turbidity in a mixture obtained by mixing the hydrogenated polymer of the polymer polymerized only from the aromatic vinyl monomer and the component (D) using a solvent as necessary, Alternatively, when phase separation between the phase containing the hydrogenated product of the polymer and the phase containing the component (D) is not visually observed, the component (D) is compatible with the polymer block A. On the other hand, when the above-mentioned turbidity or phase separation is visually observed, the component (D) is not compatible with the polymer block A.

Since the pressure-sensitive adhesive composition according to the present embodiment contains the component (D), the component (D) is compatible with the polymer block A, and therefore, the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition has a certain amount. It is possible to improve the adhesion to the adherend and to improve the heat resistance of the pressure-sensitive adhesive layer.

The component (D) can be, for example, an aromatic tackifier resin. The aromatic tackifying resin used as the component (D) preferably has a molecular weight of 5,000 or less from the viewpoint of compatibility.

Examples of aromatic tackifying resins that can be used as the component (D) include aromatic petroleum resins, styrene polymers, α-methylstyrene polymers, styrene- (α-methylstyrene) copolymers, Examples thereof include styrene-aliphatic hydrocarbon copolymers, styrene- (α-methylstyrene) -aliphatic hydrocarbon copolymers, styrene-aromatic hydrocarbon copolymers, and the like.

More specifically, for example, FMR-0150 as a commercially available styrene-aromatic hydrocarbon copolymer (softening point 145 ° C., manufactured by Mitsui Chemicals), FTR-as a styrene-aliphatic hydrocarbon copolymer 6100 (softening point 100 ° C., Mitsui Chemicals), FTR-6110 (softening point 110 ° C., Mitsui Chemicals) and FTR-6125 (softening point 125 ° C., Mitsui Chemicals), styrene (α-methylstyrene) ) -FTR-7100 as an aliphatic hydrocarbon copolymer (softening point 100 ° C., manufactured by Mitsui Chemicals), FTR-8120 as a styrene polymer (softening point 120 ° C., manufactured by Mitsui Chemicals) and SX- 100 (softening point 100 ° C., manufactured by Yasuhara Chemical), FTR-0100 (softening point 100 ° C., manufactured by Mitsui Chemicals) as an α-methylstyrene polymer, styrene (α-methyl) Tylene) FTR-2120 (softening point 120 ° C., Mitsui Chemicals), FTR-2140 (softening point 145 ° C., Mitsui Chemicals), Crystallex 3100 (softening point 100 ° C., Eastman Chemical) ), Crystallex 3085 (softening point 85 ° C., Eastman Chemical), Crystallex 5140 (softening point 140 ° C., Eastman Chemical), Crystallex 1120 (softening point 120 ° C., Eastman Chemical) ), Crystallex F85 (softening point 85 ° C., Eastman Chemical Co.), Crystallex F100 (softening point 100 ° C., Eastman Chemical Co.) and Crystallex F115 (softening point 115 ° C., Eastman Chemical Co.), Etc. can also be used. As the component (D), one type may be used alone, or two or more types may be used in combination.

From the viewpoint that durability can be imparted to the pressure-sensitive adhesive composition according to this embodiment, adhesion with the adherend can be increased, and durability can be increased, the softening point of the component (D) is 80. The temperature can be higher than 95 ° C, and preferably higher than 95 ° C.

From the viewpoint of improving compatibility with the component (A), the content of the component (D) in the pressure-sensitive adhesive composition according to this embodiment is 5 parts by mass or more and 80 parts by mass with respect to 100 parts by mass of the component (A). The amount is preferably not more than part by mass, more preferably not less than 10 parts by mass and not more than 50 parts by mass.

1.5. (E) Second compatibilizer The second compatibilizer (hereinafter sometimes simply referred to as “component (E)”) is used as the block copolymer (a1) or the block copolymer constituting component (A). It has a property compatible with the polymer block B contained in the polymer (a2), is liquid at room temperature (23 ° C.), and is dissolved in the component (C).

In the present invention, “liquid” includes viscous viscoelastic liquid and other low viscosity liquid.

In the present invention, “the (E) component is dissolved in the (C) component” means that the (E) component is not visually confirmed in the pressure-sensitive adhesive composition, and dullness and cloudiness are also present in the pressure-sensitive adhesive. It means that it is not found in the composition, and further, it means that no clogging occurs when it is filtered through a filter paper having an opening of 1 μm and there is no residue on the filter paper.

In the present invention, “compatible” or “compatibilizing” means that turbidity or phase separation is not visually confirmed in a mixture obtained by mixing two different components. .

Here, whether or not the component (E) is compatible with the polymer block B is a component corresponding to the polymer block B, that is, a hydrogenated polymer synthesized from only a conjugated diene monomer. And (E) component.

More specifically, generation of turbidity in a mixture obtained by mixing the hydrogenated polymer of the polymer polymerized only from the conjugated diene monomer and the component (E) using a solvent as necessary, or In the case where phase separation between the phase containing the hydrogenated product of the polymer and the phase containing the component (E) is not visually observed, the component (E) is compatible with the polymer block B. On the other hand, when the above-described turbidity or phase separation is visually observed, the component (E) is not compatible with the polymer block B.

When the pressure-sensitive adhesive composition according to this embodiment contains the component (E), the component (E) is compatible with the polymer block B, so that the wet-ability of the pressure-sensitive adhesive layer is increased. As a result, durability can be enhanced.

The component (E) can be a softener containing an aliphatic hydrocarbon such as a polybutene compound, a polyisobutylene compound, or a polyisoprene compound.

Examples of the softener usable as the component (E) include commercially available softeners such as Nisseki Polybutene LV-7, LV-50, LV-100, HV-15, HV-35, HV-50 as polybutene compounds. HV-100, HV-300, HV-1900, and SV-7000 (all manufactured by JX Nippon Oil & Energy Corporation), Tetrax 3T, 4T, 5T and 6T as polyisobutylene compounds, Highmol 4H, 5H, 5. 5H and 6H (both manufactured by JX Nippon Oil & Energy Corporation) and Claprene LIR-290 (manufactured by Kuraray Co., Ltd.) can also be used as the polyisoprene compound. As the component (E), one type may be used alone, or two or more types may be used in combination.

From the viewpoint of improving compatibility with the component (A), the content of the component (E) in the pressure-sensitive adhesive composition according to this embodiment is 10 parts by mass or more and 150 parts by mass with respect to 100 parts by mass of the component (A). More preferably, it is at most 15 parts by mass, and more preferably at least 15 parts by mass and at most 130 parts by mass.

Furthermore, the total content of the component (D) and the component (E) is preferably 20 parts by mass or more and 200 parts by mass or less, and 25 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the component (A). More preferably.

It is preferable that the pressure-sensitive adhesive composition according to this embodiment includes a component (D) and a component (E). In the pressure-sensitive adhesive composition according to this embodiment, the component (D) is compatible with the polymer block A contained in the block copolymer (a1) or the block copolymer (a2) constituting the component (A). The cohesive force of the pressure-sensitive adhesive is obtained when the component (E) is compatible with the polymer block B contained in the block copolymer (a1) or the block copolymer (a2) constituting the component (A). Durability can be increased by increasing.

More specifically, the heat resistance is improved by the component having a high softening point due to the compatibility with the polymer block A constituting the component (A) due to the component (D), and the component (E). The durability of the pressure-sensitive adhesive layer can be increased by two interactions with improvement in wettability to the adherend. Thereby, the adhesive layer excellent in durability, adhesiveness, and a weather resistance can be obtained.

1.6. Uses The use of the pressure-sensitive adhesive composition according to the present embodiment is not particularly limited as long as it is a use requiring transparency, adhesion, level difference followability or moisture heat whitening resistance. It can be suitably used for optical applications.

More specifically, the pressure-sensitive adhesive composition according to this embodiment can be used for bonding members constituting an image display device or an input / output device.

The member to be bonded using the pressure-sensitive adhesive composition according to the present embodiment is, for example, an optical member (for example, a polarizing film, a retardation film, an elliptically polarizing film, an antireflection film, a brightness enhancement film, a light diffusion film). And an optical film selected from the group consisting of hard coat films), a metal layer such as an ITO layer, or a substrate made of glass or plastic.

For example, the pressure-sensitive adhesive composition according to this embodiment can be suitably used for bonding members constituting the touch panel type input / output device.

An example in which the pressure-sensitive adhesive composition according to this embodiment is used for bonding members constituting a touch panel type input / output device will be described with reference to FIG.

FIG. 1 is a cross-sectional view schematically showing a configuration of an input / output device (touch panel type input / output device 100) according to an embodiment of the present invention. The touch panel type input / output device 100 according to the present embodiment includes a liquid crystal display device (LCD) 10, a touch panel unit 20, and an adhesive layer 30 provided between the LCD 10 and the touch panel unit 20. The adhesive layer 30 bonds the LCD 10 and the touch panel unit 20 together.

The adhesive layer 30 is formed by, for example, applying the pressure-sensitive adhesive composition according to the present embodiment to the surface of a separator (not shown) and peeling the adhesive sheet obtained by drying from the separator, and the LCD 10 and the touch panel 20. It was installed between.

Further, as shown in FIG. 1, the LCD 10 is configured by laminating a polarizing plate 11, an adhesive layer 12, a liquid crystal panel 13, an adhesive layer 14, and a polarizing plate 15 in this order. The pressure-sensitive adhesive layer 12 bonds the polarizing plate 11 and the liquid crystal panel 13, and the pressure-sensitive adhesive layer 14 bonds the liquid crystal panel 13 and the polarizing plate 15.

Further, as shown in FIG. 1, the touch panel unit 20 is configured by a scattering prevention film 16, an adhesive layer 17, an ITO layer 18, and a glass panel 19 laminated in this order. The pressure-sensitive adhesive layer 17 bonds the scattering prevention film 16 and the ITO layer 18.

The adhesive layers 12, 14, and 17 are adhesive sheets obtained by applying the adhesive composition according to the present embodiment to the surface of a separator (not shown) and drying volatile components, like the adhesive layer 30. Is peeled off from the separator and installed.

1.7. Effect The pressure-sensitive adhesive composition according to this embodiment comprises (A) component 100 parts by mass, (B) component 0.01 part by mass to 5 parts by mass, and (C) component, and (A The component (B) and the component (B) are both excellent in transparency because they are dissolved in the component (C).

In addition, in the pressure-sensitive adhesive layer obtained by removing the solvent (C) after forming a film using the pressure-sensitive adhesive composition, the molecular weight of the compound (B) is as low as 2,000 or less, It is possible to obtain a pressure-sensitive adhesive layer that is excellent in dispersibility of the compound (B) and in which the compound (B) is hardly precipitated. Thereby, the pressure-sensitive adhesive layer has high transparency and is excellent in moisture and heat whitening resistance.

Therefore, the pressure-sensitive adhesive layer can be suitably used for applications requiring transparency, and can impart adhesion and durability with an additive. Floating and peeling due to the generated gas (water vapor or a volatile component derived from the adherend) can be suppressed. Accordingly, for example, an image display device having high quality and excellent durability can be obtained using the pressure-sensitive adhesive layer.

As described in the Background section, hydrogenated block copolymers generally have strong self-adhesive properties (self-blocking properties), so the surface of the particles is usually coated with an anti-blocking agent such as talc or organic polymer particles. By covering, measures are taken to prevent self-adhesion (blocking) of the particles. However, the pressure-sensitive adhesive layer formed using a hydrogenated block copolymer to which talc or general organic polymer particles are attached has a tendency to deposit organic polymer components, or talc or the like to be a hydrogenated block copolymer. Due to the incompatibility with the body, transparency, adhesiveness and wet heat whitening resistance may be inferior.

In general, in order to obtain a highly transparent pressure-sensitive adhesive layer, a process of removing insoluble components (such as talc) contained in the pressure-sensitive adhesive composition by washing and filtration is essential. If it contains an insoluble component, the filter is likely to be clogged, and not only smooth filtration is possible, but even after passing through a filtration step, a trace amount of insoluble component is present in the system after filtration. Therefore, it is difficult to obtain a pressure-sensitive adhesive layer having high transparency.

On the other hand, according to the pressure-sensitive adhesive composition according to this embodiment, since both the component (A) and the component (B) are dissolved in the component (C), the pressure-sensitive adhesive layer is formed. Since it is not necessary to remove (B) component, the effort at the time of producing an adhesive layer can be reduced. Moreover, when the molecular weight of (B) component is 2000 or less, it is excellent in the solubility of this (B) component in the obtained adhesive layer, and this (B) component cannot precipitate easily. Thereby, the adhesive layer excellent in transparency, adhesiveness, and heat-and-moisture whitening resistance can be formed using the adhesive composition which concerns on this embodiment.

Moreover, the adhesive composition which concerns on this embodiment contains the (D) component and (E) component excellent in compatibility with (A) component, and has the adhesiveness and the level | step difference followable | trackability which were excellent. A layer can be obtained.

2. Manufacturing method of adhesive composition The manufacturing method of the adhesive composition of the invention which concerns on one Embodiment of this invention is (A) component, (B) component, (C) component, and (D) component as needed. (E) It is a method of manufacturing the adhesive composition which concerns on the said embodiment containing a component, Comprising: (A) 100 mass parts of components contain (B) component 0.01 mass part or more and 5 mass parts or less. Hydrogenated block copolymer composition pellets, wherein (B) component is present inside and on the surface of the pellet, the hydrogenated block copolymer composition pellets are dissolved in component (C) Process.

According to the method for producing a pressure-sensitive adhesive composition of the present invention, the step of dissolving the pellet in the component (C) includes the step of dissolving the component (A) and the component (B) in the component (C). The obtained pressure-sensitive adhesive composition can be obtained. Thereby, the adhesive layer excellent in transparency and moisture-and-heat whitening resistance can be obtained using this adhesive composition.

In addition, as a manufacturing method of the hydrogenated block copolymer composition pellet which (B) component exists in the inside and the surface of the pellet which consists of (A) component, (A) component and (B) component (internal use) are mentioned, for example The composition is kneaded to produce pellets, and then component (B) (for surface) may be externally added to the pellet surface. The component (B) present inside and on the surface of the pellet may be the same or different.

Moreover, when the adhesive composition of this invention contains (D) component and / or (E) component, in the manufacturing process of the said adhesive composition, it is added simultaneously with the said pellet and becomes (C) component. Alternatively, after the pellets are added and dissolved, the component (D) and / or the component (E) may be added to the composition solution and dissolved in the component (C).

3. Pressure-sensitive adhesive layer (pressure-sensitive adhesive sheet) and method for producing the same The pressure-sensitive adhesive layer (pressure-sensitive adhesive sheet) according to an embodiment of the present invention comprises (A) component 100 parts by weight and (B) component 0.01 parts by weight to 5 parts by weight. Includes:

The pressure-sensitive adhesive layer according to this embodiment can be obtained by removing the component (C) from the pressure-sensitive adhesive composition according to the above-described embodiment. That is, the method for producing a pressure-sensitive adhesive layer (pressure-sensitive adhesive sheet) according to one embodiment of the present invention includes a step of applying a pressure-sensitive adhesive composition according to the above-described embodiment onto a substrate to obtain a film, and drying the film. And removing the component (C) to obtain a pressure-sensitive adhesive layer.

According to the method for producing a pressure-sensitive adhesive layer according to this embodiment, in the pressure-sensitive adhesive composition according to the above-described embodiment, the component (A) and the component (B) are dissolved in the component (C), and the component (B) Since the molecular weight of 2,000 or less is excellent in solubility of the component (B) in the obtained pressure-sensitive adhesive layer and the component (B) hardly precipitates in the pressure-sensitive adhesive layer, transparency, adhesive strength In addition, a pressure-sensitive adhesive layer excellent in moisture and heat whitening resistance can be obtained.

For example, the pressure-sensitive adhesive layer according to the present embodiment is prepared by applying the pressure-sensitive adhesive composition according to the present embodiment to the surface of the release substrate (separator) and holding the separator at a temperature at which the component (C) evaporates. (Adhesive sheet) can be obtained.

More specifically, the pressure-sensitive adhesive composition according to the present embodiment is applied onto a release substrate with a gravure coater, a Mayer bar coater, an air knife coater, a roll coater, and the like. For example, the pressure-sensitive adhesive layer according to this embodiment can be produced by holding at 15 ° C. or higher and 40 ° C. or lower) or by appropriately heating (for example, 40 ° C. or higher and 200 ° C. or lower).

The pressure-sensitive adhesive layer according to the present embodiment is more excellent in transparency, and the total light transmittance can be 80% or more in the JIS K7361 method, and preferably 90% or more.

In addition, the pressure-sensitive adhesive layer according to the present embodiment can have a storage elastic modulus of 1 × 10 ⁴ Pa or more and 2 × 10 ⁶ Pa or less at 25 ° C. and 1 Hz because it is more excellent in durability. It is preferable that it is 10 ⁴ Pa or more and 1 × 10 ⁶ Pa or less.

The thickness of the pressure-sensitive adhesive layer according to this embodiment is usually in the range of 10 μm to 500 μm, preferably 20 μm to 300 μm.

4). EXAMPLES Hereinafter, the present invention will be described based on the following examples, but the present invention is not limited to the examples.

4.1. Preparation of hydrogenated block copolymer composition pellets 4.1.1. Synthesis of hydrogenated block copolymer [Synthesis Example 1]
A pressure-resistant container purged with nitrogen and dried was charged with 2,500 ml of cyclohexane as a solvent and 26.4 ml of sec-butyllithium (cyclohexane solution) having a concentration of 10.5% by mass as an initiator, and heated to 50 ° C. 101 ml of styrene was added and polymerized for 60 minutes.
Then, after raising the temperature to 60 ° C., 10 ml of isoprene was added to react, and after 3 minutes, the same amount of isoprene was added and reacted repeatedly, and finally 1092 ml of isoprene was added in total. Thereafter, the reaction was further continued for 90 minutes, and then the polymerization was stopped with 1.5 ml of methanol to obtain a polymerization reaction solution containing a block copolymer.
To the reaction mixture, 41.8 g of palladium carbon (palladium supported amount: 5 mass%) was added as a hydrogenation catalyst, and a hydrogenation reaction was performed at a hydrogen pressure of 2 MPa and 150 ° C. for 10 hours. After allowing to cool and release the pressure, palladium carbon was removed by filtration, and the filtrate was concentrated and further vacuum dried to obtain a hydrogenated product (1) -1 of the block copolymer (a1).
As a result of analyzing the obtained hydrogenated product (1) -1, it was a hydrogenated product of a styrene-isoprene diblock copolymer, the styrene content was 11% by mass, and the weight average molecular weight was 46,100. The hydrogenation rate was 99.8%.

[Synthesis Example 2]
A pressure-resistant container purged with nitrogen and dried was charged with 3,000 ml of cyclohexane as a solvent and 2.8 ml of sec-butyllithium (cyclohexane solution) having a concentration of 10.5% by mass as an initiator, and the temperature was raised to 50 ° C. 25 ml of styrene was added and polymerized for 60 minutes.
Thereafter, the temperature was raised to 60 ° C., 10 ml of isoprene was added and reacted, and after 3 minutes, the same amount of isoprene was added and reacted, and a total of 540 ml of isoprene was finally added. The reaction was driven for another 90 minutes.
Further, 25 ml of styrene was added at the same temperature for polymerization for 60 minutes, and then the polymerization was stopped with 0.16 ml of methanol to obtain a polymerization reaction solution containing a block copolymer.
To this reaction mixture, 20.6 g of palladium carbon (palladium supported amount: 5% by mass) was added as a hydrogenation catalyst, and a hydrogenation reaction was performed at a hydrogen pressure of 2 MPa and 150 ° C. for 10 hours. After allowing to cool and release the pressure, palladium carbon was removed by filtration, and the filtrate was concentrated and further vacuum dried to obtain a hydrogenated product (2) -1 of the block copolymer (a2).
As a result of analyzing the obtained hydrogenated product (2) -1, it was a hydrogenated product of a styrene-isoprene-styrene triblock copolymer, the styrene content was 11% by mass, and the weight average molecular weight was 215,300. The hydrogenation rate was 99.3%.

4.1.2. Preparation of Hydrogenated Block Copolymer Composition Pellets Hydrogenated products (1) -1 and (2) -1 obtained in Synthesis Examples 1 and 2 were converted into (1) -1 / (2) -1 = 60 / Premixed at a mass ratio of 40, and Adeka Stub AO-60 as component (B) (for internal addition (internal addition)) with respect to a total of 100 parts by mass of hydrogenated products (1) -1 and (2) -1 0.2 parts by mass and further premixed, and then melt-kneaded at 200 ° C. in a twin-screw extruder, and the hydrogenated block copolymer in which component (B) is mixed in component (A) A pellet made of the composition was obtained.
Next, externally adding the component (B) (for external addition (external addition)) shown in Table 1 and Table 2 to 100 parts by mass of the component (A) in the formulation shown in Table 1 and Table 2, (B) The hydrogenated block copolymer composition pellet which a component exists in the inside and surface of a pellet was prepared.

4.2. Preparation of pressure-sensitive adhesive compositions The components shown in Tables 1 and 2 were mixed to prepare pressure-sensitive adhesive compositions of Examples 1 to 9 and Comparative Examples 1 to 4, respectively. In the preparation of the pressure-sensitive adhesive composition, the component (A) and the component (B) are the same as those in 4.1.2. It blended as a hydrogenated block copolymer composition pellet prepared by the production method described in the column.

That is, the hydrogenated block copolymer composition pellets containing the component (A) and the component (B) and other components were dissolved in the component (C), and Examples 1 to 9 and Comparative Examples 1 to 4 were dissolved. Each pressure-sensitive adhesive composition was prepared.

In the pressure-sensitive adhesive compositions of Examples 1 to 9, no solid was visually confirmed in the pressure-sensitive adhesive composition, and neither dullness nor cloudiness was observed in the pressure-sensitive adhesive composition. Further, when the pressure-sensitive adhesive compositions of Examples 1 to 9 were filtered through a filter paper having an opening of 1 μm, no clogging was produced, and no residue was found on the filter paper. From this, in the pressure-sensitive adhesive compositions of Examples 1 to 9, it was confirmed that (A) component, (B) component, (D) component and (E) component were dissolved in (C) component. .

In the pressure-sensitive adhesive compositions of Examples 1 to 9, the total light transmittance was 90% or more. From this, it can be understood that (A) component, (B) component, (D) component and (E) component are dissolved in (C) component in the adhesive compositions of Examples 1 to 9. .

On the other hand, in the pressure-sensitive adhesive compositions of Comparative Examples 1 to 4, a solid was visually confirmed in the pressure-sensitive adhesive composition. Further, when the pressure-sensitive adhesive compositions of Comparative Examples 1 to 4 were filtered through a filter paper having an opening of 1 μm, a residue was confirmed on the filter paper. Furthermore, in the pressure-sensitive adhesive compositions of Comparative Examples 1 to 4, the total light transmittance was less than 80%. From this, in the adhesive compositions of Comparative Examples 1 to 4, it was confirmed that the support particles added instead of the component (B) were not dissolved in the component (C).

4.3. Evaluation method 4.3.1. Haze / total light transmittance (transparency, heat and humidity resistance against whitening)
(initial)
The pressure-sensitive adhesive composition solutions obtained in Examples and Comparative Examples were applied onto a peeled polyethylene terephthalate film so that the thickness after drying was 50 μm, and then the solvent was removed with a dryer at 80 ° C. did. A polyethylene terephthalate film subjected to a release treatment was bonded to the pressure-sensitive adhesive coated surface to obtain a pressure-sensitive adhesive sheet.

The polyethylene terephthalate film on one side of the obtained pressure-sensitive adhesive sheet was peeled off and bonded to glass to prepare a test piece. After the test piece was autoclaved (50 ° C., 5 atm, 20 minutes), the other polyethylene terephthalate film was removed, and the haze and total light transmittance of the adhesive layer were measured using a haze meter (model name “HM-150”, Murakami Color). The measurement was performed using a technical laboratory.

(After wet heat)
The pressure-sensitive adhesive composition solutions obtained in Examples and Comparative Examples were applied onto a peeled polyethylene terephthalate film so that the thickness after drying was 50 μm, and then the solvent was removed with a dryer at 80 ° C. did. A polyethylene terephthalate film subjected to a release treatment was bonded to the pressure-sensitive adhesive coated surface to obtain a pressure-sensitive adhesive sheet.

The polyethylene terephthalate film on one side of the obtained pressure-sensitive adhesive sheet was peeled off and bonded to glass to prepare a test piece. The test piece was autoclaved (50 ° C., 5 atm, 20 minutes), placed in a 85 ° C., 85% dryer for 24 hours, taken out in an environment at 23 ° C., 50%, left for 1 hour, and then the other polyethylene. The terephthalate film was removed, and the haze and total light transmittance of the pressure-sensitive adhesive layer were measured using a haze meter (model name “HM-150”, manufactured by Murakami Color Research Laboratory Co., Ltd.).

4.3.2. Adhesive strength (adhesion)
(initial)
The pressure-sensitive adhesive composition solutions obtained in Examples and Comparative Examples were coated on a peeled polyethylene terephthalate film so that the thickness after drying was 50 μm, and the solvent was removed with a dryer at 80 ° C. Subsequently, the polyethylene terephthalate film which peel-processed on the adhesive coating surface was bonded together, and the adhesive sheet was obtained.

The polyethylene terephthalate film on one side of the obtained pressure-sensitive adhesive sheet was peeled off, a polyethylene terephthalate film having a thickness of 100 μm was bonded, and cut into a width of 25 mm to prepare a test piece.

The polyethylene terephthalate film from which the test piece was peeled was peeled off, and the exposed adhesive-coated surface was pressure-bonded to glass using a 2 kg roller. Twenty minutes after pasting, the adhesive sheet was peeled from the glass plate (23 ° C., peeling angle 180 °, peeling speed 300 mm / min), and the initial adhesive strength was measured.

(After wet heat)
The pressure-sensitive adhesive composition solutions obtained in Examples and Comparative Examples were applied on a peeled polyethylene terephthalate film so that the thickness after drying was 50 μm, and the solvent was removed with a dryer at 80 ° C. Subsequently, the polyethylene terephthalate film which peel-processed on the adhesive coating surface was bonded together, and the adhesive sheet was obtained.

The polyethylene terephthalate film on one side of the obtained pressure-sensitive adhesive sheet was peeled off, a polyethylene terephthalate film having a thickness of 100 μm was bonded, and cut into a width of 25 mm to prepare a test piece.

The polyethylene terephthalate film from which the test piece was peeled was peeled off, and the exposed adhesive-coated surface was pressure-bonded to glass using a 2 kg roller. After putting it in an environment of 85 ° C and 85% for 24 hours and leaving it in an environment of 23 ° C and 50% for 1 hour, the adhesive sheet is peeled off from the glass plate (23 ° C, peeling angle 180 °, peeling speed 300 mm / min) The adhesive strength was measured after wet heat.

4.3.3. Step followability The evaluation test body was obtained by transferring the 50 μm thick adhesive sheet obtained by the production method described in 4.3.1 above to a 100 μm thick polyethylene terephthalate film.
On the other hand, a glass plate having an arbitrary step on the surface was prepared to prepare an adherend for the test. In addition, the level | step difference provided on the glass plate in this test was formed by sticking the polyethylene terephthalate adhesive tape which has predetermined | prescribed fixed thickness on the surface of a glass plate. The thickness of the polyethylene terephthalate pressure-sensitive adhesive tape attached to the surface of the glass plate is two types of 25% and 15% with respect to the pressure-sensitive adhesive layer thickness. That is, two types of steps are provided on the surface of the glass plate.
By the above method, a 50 μm thick adhesive sheet transferred to a 100 μm thick polyethylene terephthalate film is attached to the surface of a glass plate having an arbitrary step on the surface, which is an adherend for this test, and the test It was a piece.
Thereafter, the test piece was autoclaved at 50 ° C. and 5 atm for 20 minutes, and then the filling of the step was visually observed (“after autoclaving” in Tables 1 and 2).
Further, the test piece was allowed to stand for 24 hours under the condition of 80 ° C. dry, and then the level difference was visually observed (“After 80 hours of 80 ° C. dry” in Tables 1 and 2).
Based on the above contents, the step following property of the pressure-sensitive adhesive layer obtained by the pressure-sensitive adhesive composition was evaluated according to the following evaluation criteria.
(Evaluation)
A: A 25% step (that is, a step of 12.5 μm) can be filled with respect to the adhesive layer thickness of 50 μm, and no voids or bubbles are visually recognized around the step.
Δ: A step of 12.5% with respect to the adhesive layer thickness of 50 μm (that is, a step of 7.5 μm) can be filled, and no voids or bubbles are visible around the step, but 25% of the adhesive layer thickness of 50 μm The step (that is, a step of 12.5 μm) could not be filled, and voids and bubbles were visually recognized around the 25% step.
X: After leaving still for 24 hours at 80 degreeCdry dryer, the space | gap and the bubble were visually recognized around the level | step difference.

4.3.4. Surface smoothness The pressure-sensitive adhesive composition solutions obtained in Examples and Comparative Examples were coated on a polyethylene terephthalate film subjected to a release treatment so that the thickness after drying was 50 μm, and the solvent was removed with a dryer at 80 ° C. Removed. The coated surface was observed visually.
○: No defects were found on the coated surface.
(Triangle | delta): Some coating stripes and nonuniformity were seen in the coating surface of what can be used practically.

4.3.5. Modulus of elasticity The adhesive composition solutions obtained in Examples and Comparative Examples were coated on a polyethylene terephthalate film that had been subjected to release treatment so that the thickness after drying would be 50 μm, and the solvent was removed with a dryer at 80 ° C. did. Next, the pressure-sensitive adhesive layer was overlapped so that the thickness of the pressure-sensitive adhesive layer was 1 mm, and autoclaved (50 ° C., 5 atm, 20 min) to obtain a test specimen for measurement.
The storage elastic modulus (frequency: 1 Hz, unit: 10 ⁵ Pa) at a temperature of 25 ° C. of the obtained measurement sample was measured using “Physica MCR300” manufactured by Anton Paar.

4.3.6. Average Particle Size of Particles The average particle size of the supported particles of Examples and Comparative Examples was measured using a scanning electron microscope (S-4800, manufactured by Hitachi High-Tech Co., Ltd.).

In addition, each component used by the Example and the comparative example is as follows.
-Component (B) Tinuvin 326: UV absorber, average particle size 0.4 μm, molecular weight 316 (manufactured by BASF)
BHT (dibutylhydroxytoluene): antioxidant, average particle size 1 μm, molecular weight 220 (manufactured by Tokyo Chemical Industry Co., Ltd.)
Benzotriazole: metal deactivator, average particle diameter 1 μm, molecular weight 119 (manufactured by Tokyo Chemical Industry Co., Ltd.)
ADK STAB AO-60: Antioxidant, average particle size 16 μm, molecular weight, 1178 (manufactured by ADEKA)
・ Other additives Talc: Inorganic particles, average particle size 5μm (manufactured by NOF Corporation)
Calcium stearate: organometallic salt particles, average particle size 1 μm, molecular weight 607 (manufactured by NOF Corporation)
PE wax: Organic polymer particles, average particle diameter 8 μm, weight average molecular weight 5,000 or more (manufactured by Yasuhara Chemical Co., Ltd.)
Component (C) Toluene: Sankyo Chemical Co., Ltd. n-Hexane: Sankyo Chemical Co., Ltd. Component (D) FTR-6100: Aromatic tackifying resin with a softening point of 100 ° C. (Mitsui Chemicals)
-(E) component HV100: Polybutene (manufactured by JX Nippon Oil & Energy Corporation)
BI-3000: Hydrogenated polybutadiene (manufactured by Nippon Soda Co., Ltd.)

4.4. Evaluation results From the results shown in Table 1, the pressure-sensitive adhesive compositions of Examples 1 to 9 of the present application include (A) component 100 parts by mass, (B) component 0.01 parts by mass to 5 parts by mass, and (C) component. And (A) component and (B) component are melt | dissolved in (C) component, and it has high transparency and was excellent in adhesiveness, level | step difference followability, and moisture-and-heat whitening resistance A layer can be obtained.

In contrast, as shown in Table 2, the compositions of Comparative Examples 1 to 3 of the present application, unlike the component (B) of the present invention, contain an additive that does not dissolve in the component (C). It can be understood that it is inferior in heat and heat whitening resistance.

Further, since the composition of Comparative Example 4 of the present application contains PE wax having a weight average molecular weight of 5,000 or more in place of the component (B), it can be understood that the composition is inferior in transparency and resistance to moist heat whitening.

Claims (13)

1. (A) 100 parts by mass of a hydrogenated block copolymer composition;
   (B) 0.01 to 5 parts by mass of a compound having a molecular weight of 2,000 or less;
   (C) a pressure-sensitive adhesive composition comprising an aliphatic hydrocarbon and / or a solvent that is an aromatic hydrocarbon that is liquid at 23 ° C.,
   The (A) hydrogenated block copolymer composition comprises the hydrogenated product (1) of the block copolymer (a1) represented by the general formula (AB) n and the general formula ABAA or ( AB) Hydrogenated product of block copolymer (a2) represented by mX (2) (in the above formula, A is the same or different and consists of a monomer unit derived from an aromatic vinyl compound) Represents polymer block A, B is the same or different and represents polymer block B composed of monomer units derived from a conjugated diene compound, n represents an integer of 1 to 3, and m represents an integer of 1 or more And X represents a coupling agent residue.)
   The pressure-sensitive adhesive composition in which the (A) hydrogenated block copolymer composition and the (B) compound are both dissolved in the solvent (C).
2. (D) further including 5 parts by weight or more and 80 parts by weight or less of the first compatibilizer;
   The (D) first compatibilizer has a property compatible with the polymer block A, has a softening point of 80 ° C or higher, and is dissolved in the (C) solvent. 2. The pressure-sensitive adhesive composition according to 1.
3. (E) further containing 10 parts by weight or more and 150 parts by weight or less of the second compatibilizer;
   The said (E) 2nd compatibilizer has a property compatible with the said polymer block B, is a liquid at 23 degreeC, and is melt | dissolving in the said (C) solvent. 2. The pressure-sensitive adhesive composition according to 1.
4. Mass ratio of the hydrogenated product (1) of the block copolymer (a1) and the hydrogenated product (2) of the block copolymer (a2) constituting the (A) hydrogenated block copolymer composition The pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the ratio is 90:10 to 10:90.
5. The pressure-sensitive adhesive according to any one of claims 1 to 4, wherein the compound (B) is at least one selected from the group consisting of an ultraviolet absorber, a light stabilizer, an antioxidant, and a metal deactivator. Agent composition.
6. The pressure-sensitive adhesive composition according to any one of claims 1 to 5, wherein the (D) first compatibilizer is an aromatic tackifying resin.
7. The aromatic tackifier resin is an aromatic petroleum resin, a styrene polymer, an α-methylstyrene polymer, a styrene- (α-methylstyrene) copolymer, or a styrene-aliphatic hydrocarbon copolymer. The pressure-sensitive adhesive according to claim 6, which is at least one selected from the group consisting of styrene- (α-methylstyrene) -aliphatic hydrocarbon copolymers and styrene-aromatic hydrocarbon copolymers. Composition.
8. The (E) second compatibilizer is at least one selected from the group consisting of a polybutene compound, a polyisobutylene compound, and a polyisoprene compound, according to any one of claims 1 to 7. Adhesive composition.
9. The total content of the (D) first compatibilizer and the (E) second compatibilizer is 20 parts by mass or more and 200 parts by mass with respect to 100 parts by mass of the (A) hydrogenated block copolymer composition. The pressure-sensitive adhesive composition according to any one of claims 1 to 8, which is as follows.
10. A method for producing the pressure-sensitive adhesive composition according to any one of claims 1 to 9,
    A pellet of the hydrogenated block copolymer composition containing 0.01 part by mass or more and 5 parts by mass or less of the compound (B) with respect to 100 parts by mass of the (A) hydrogenated block copolymer composition, The manufacturing method of an adhesive composition including the process of dissolving the hydrogenated block copolymer composition pellet which the said (B) compound exists in the inside and surface of a pellet in the said (C) solvent.
11. Applying the pressure-sensitive adhesive composition according to any one of claims 1 to 9 onto a substrate to obtain a film;
    And (c) removing the solvent to obtain a pressure-sensitive adhesive layer by drying the film.
12. (A) 100 parts by mass of a hydrogenated block copolymer composition;
    (B) A pressure-sensitive adhesive layer containing 0.01 to 5 parts by mass of a compound having a molecular weight of 2,000 or less,
    The (A) hydrogenated block copolymer composition comprises the hydrogenated product (1) of the block copolymer (a1) represented by the general formula (AB) n and the general formula ABAA or ( AB) Hydrogenated product of block copolymer (a2) represented by mX (2) (in the above formula, A is the same or different and consists of a monomer unit derived from an aromatic vinyl compound) Represents polymer block A, B is the same or different and represents polymer block B composed of monomer units derived from a conjugated diene compound, n represents an integer of 1 to 3, and m represents an integer of 1 or more And X represents a coupling agent residue.)
    The (A) hydrogenated block copolymer composition and the compound (B) are both dissolved in (C) a solvent that is an aliphatic hydrocarbon and / or an aromatic hydrocarbon that is liquid at 23 ° C. A pressure-sensitive adhesive layer having properties.
13. The pressure-sensitive adhesive layer according to claim 12, which is obtained by removing the solvent (C) from the pressure-sensitive adhesive composition according to any one of claims 1 to 9.

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