TW201606021A - Adhesive composition, adhesive sheet, laminate, picture display device and output/input device - Google Patents

Abstract

This invention provides an adhesive composition, which includes (A) at least one of a block copolymer selected from an X-Y-X-type hydrogenated styrenic block copolymer and an X-Y-type hydrogenated styrenic block copolymer, (B) a softener as a liquid under room temperature (23 DEG C), (C) a terpene tackifier resin, and (D) an aromatic tackifier resin, wherein, with respect to the (A) block copolymer 100 parts by mass, the composition includes the (B) softener 10 parts by mass or more and 300 parts by mass or less, the (C) terpene tackifier resin 1 part by mass or more and 30 parts by mass or less, and the (D) aromatic tackifier resin 1 part by mass or more and 50 parts by mass or less, respectively. In addition, with respect to the content of the (B) softener, the content of the (C) terpene tackifier resin (the content of the (C) terpene tackifier resin / the content of the (B) softener) is 0.05 or more and 0.70 or less.

Description

Adhesive composition, adhesive sheet, laminated body, image display device, and output input device

The present invention relates to an adhesive composition, an adhesive sheet, a laminate, an image display device, and an output input device.

In recent years, development of various functions for an adhesive composition has been actively carried out (for example, Patent Publication 1).

[Previous Technical Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2011-63639

The inventors of the present invention have found that the use of an adhesive sheet formed of an adhesive composition having a specific composition makes it difficult to cause deterioration of the adhesive sheet over time (adhesion reduction, etc.) even after long-term storage, thereby completing the low-polarity adhesion of the present invention. Agent composition. The present invention provides an adhesive composition, an adhesive sheet, a laminate, and an image display device using the adhesive composition And an output input device, the adhesive composition can maintain adhesion for a long period of time, has high transparency and low dielectric constant, and can obtain adhesion, weather resistance, flexibility, flexibility, viscosity, and order Adhesive layer excellent in step followability and resistance to moist heat whitening.

An adhesive composition according to an aspect of the invention comprising: (A) at least one block selected from the group consisting of an XYX type hydrogenated styrene block copolymer and an XY type hydrogenated styrene block copolymer. a copolymer, (B) a liquid softener at normal temperature (23 ° C), (C) a terpene tackifying resin, and (D) an aromatic tackifying resin, wherein the block copolymerization with respect to the above (A) 100 parts by mass of the above-mentioned (B) softener, 10 parts by mass or more and 300 parts by mass or less, and (C) a terpene-based tackifying resin: 1 part by mass or more and 30 parts by mass or less, and the (D) aromatic-based thickening layer 1 part by mass or more and 50 parts by mass or less of the resin, and the content of the (C) terpene-based tackifying resin relative to the content of the (B) softening agent (the content of the (C) terpene-based tackifying resin / the foregoing ( B) The content of the softening agent is 0.05 or more and 0.70 or less.

2. The adhesive composition according to the above 1, wherein the (A) block copolymer is a mixture of an X-Y-X type hydrogenated styrene block copolymer and an X-Y type hydrogenated styrene block copolymer.

3. The adhesive composition according to the above 1 or 2, wherein the (A) block copolymer has a styrene content of 10% by mass or more and 35 masses. The amount is below %.

4. The adhesive composition according to any one of the above 1 to 3, wherein the adhesive layer obtained from the adhesive composition has a relative dielectric constant of 1 or more and 3.5 or less.

In the adhesive composition according to any one of the above 1 to 4, the water vapor permeability of the adhesive layer having a film thickness of 50 μm obtained from the adhesive composition may be JIS Z0208, 40 ° C × 90% Less than 100g/m ^{2 in} RH. day.

6. The adhesive composition according to any one of the above 1 to 5, which can be used for bonding a member constituting a touch panel type input/output device.

7. The adhesive composition according to any one of the above 1 to 5, which can be used for bonding a member constituting an organic EL display.

8. The layered body according to one aspect of the invention, comprising the adhesive layer formed of the adhesive composition according to any one of the above 1 to 5, and a barrier film.

An adhesive sheet according to an aspect of the present invention, which is obtained by drying a film formed of the adhesive composition according to any one of the above 1 to 5.

An image display device according to an aspect of the invention, comprising the adhesive layer formed using the adhesive composition according to any one of the above 1 to 5.

An output input device according to an aspect of the invention, comprising the adhesive layer formed using the adhesive composition according to any one of items 1 to 5 above.

The adhesive composition according to any one of the above 1 to 5, which comprises (adapted) the (A) block copolymer, the (B) softener, and the (C) decene by a predetermined ratio. The adhesive resin and the (D) aromatic tackifying resin can provide an adhesive composition which is excellent in adhesive properties and which is less likely to deteriorate with time when the adhesive sheet is formed.

Further, the above-mentioned adhesive composition has the following feature: the (A) block copolymer, the (B) softener, the (C) terpene tackifying resin, and the above (D) are contained in the above ratio. Since the aromatic tackifying resin is low in polarity and hydrophobic, the obtained adhesive layer has a low relative dielectric constant and is excellent in water vapor barrier properties.

Thus, the adhesive layer (adhesive sheet) obtained by using the above-described adhesive composition can be used, for example, for bonding a member constituting a touch panel type input/output device or for requiring water vapor barrier properties (for example, an organic EL display) It is used in applications such as image display devices or output input devices that are vulnerable to water.

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

1, 111‧‧‧ substrate

2, 12, 14, 17, 30‧‧ ‧ adhesive layer

3‧‧‧Organic EL components

10‧‧‧Liquid Crystal Display Unit (LCD)

11, 15‧‧‧ polarizing plate

13‧‧‧LCD panel

16‧‧‧Smashproof film

18‧‧‧ITO layer

19‧‧‧ glass panel

20‧‧‧Touch Panel Department

21‧‧‧The first layer of the substrate

22‧‧‧The second layer of the substrate

100‧‧‧Touch panel type input input device

110, 120, 130‧‧ ‧ laminated body

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

Figure 2 is a schematic representation of an embodiment of the present invention. A cross-sectional view of a water vapor barrier laminate of an adhesive layer formed by an adhesive composition.

Fig. 3 is a cross-sectional view schematically showing a water vapor barrier layered product comprising an adhesive layer formed of an adhesive composition according to an embodiment of the present invention.

Fig. 4 is a cross-sectional view schematically showing a water vapor barrier layered product comprising an adhesive layer formed of an adhesive composition according to an embodiment of the present invention.

[Formation for implementing the invention]

Adhesive composition

An adhesive composition according to an embodiment of the present invention, comprising: (A) at least one selected from the group consisting of an XYX type hydrogenated (hydrogenated) styrene block copolymer and an XY type hydrogenated styrene block copolymer; One type of block copolymer (hereinafter sometimes referred to as "(A) component"), (B) a liquid softener at normal temperature (23 ° C) (hereinafter, simply referred to as "(B) component"), (C) a terpene-based tackifying resin (hereinafter sometimes referred to simply as "(C) component") and (D) an aromatic tackifying resin (hereinafter, simply referred to as "(D) component").

The adhesive composition of the present embodiment contains 10 parts by mass or more and 300 parts by mass or less of the component (B), and 1 part by mass or more and 30 parts by mass or less of the component (C), and (D), per 100 parts by mass of the component (A). The component is 1 part by mass or more and 50 parts by mass or less.

Further, in the adhesive composition of the present embodiment, the content of the component (C) (the content of the component (C) / the component (B) with respect to the content of the component (B) The content) is 0.05 or more and 0.70 or less.

The inventors of the present invention have found that the component (C) contained in the adhesive composition of the present embodiment can suppress deterioration of the adhesive sheet over time. More specifically, the inventors of the present invention have found that the component (C) in the adhesive composition of the present embodiment prevents the component (B) from moving toward the surface of the adhesive layer (adhesive sheet), and as a result, the adhesive layer can be suppressed. The (adhesive sheet) deteriorates with time.

When the component (B) has a low molecular weight (for example, a weight average molecular weight of 5,000 or less), since it is a low molecular weight and easily moves toward the surface of the adhesive layer (adhesive sheet), the adhesive layer (adhesive sheet) is likely to occur. Deteriorated over time. In this case, by disposing the component (C) in the adhesive composition of the present embodiment, the deterioration of the adhesive layer (adhesive sheet) over time can be effectively suppressed.

The mechanism for suppressing the deterioration of the adhesive sheet obtained by the adhesive composition of the present embodiment in the component (C) is not clear, but it is considered that the compatibility of the component (C) with the components (A) and (B) is good. And/or by disposing the component (C) on the surface of the adhesive layer obtained from the adhesive composition of the present embodiment, the component (B) can be prevented from moving toward the surface of the adhesive layer (adhesive sheet). It is presumed that it is possible to provide an adhesive sheet which does not deteriorate in adhesion or the like even when stored for a long period of time, and which is less likely to deteriorate with time.

Furthermore, the inventors of the present invention have found that the content of the component (C) in the adhesive composition of the present embodiment and the content of the component (B) are 0.05 or more and 0.70 or less, whereby the adhesiveness can be achieved. Deterioration prevention, good step followability and adhesion performance.

In the present invention, "compatible" or "compatibilizing" means a mixture obtained by mixing two different components. In the case of turbidity or phase separation, it is not possible to confirm with the naked eye.

1.1. (A) component

The component (A) is a block copolymer selected from at least one of an X-Y-X type hydrogenated styrene block copolymer and an X-Y type hydrogenated styrene block copolymer. Since the component (A) has low polarity and hydrophobicity, it contributes to a low relative dielectric constant and water vapor barrier property of the adhesive layer formed of the adhesive composition of the present embodiment.

The XYX type hydrogenated styrene block copolymer and the XY type hydrogenated styrene block copolymer of the component (A) are hard segments (X) having a polymer component derived from an aromatic vinyl monomer and are derived from a total of A thermoplastic elastomer of a soft segment (Y) of a polymer component of a conjugated diene monomer. More specifically, the aromatic vinyl compound is preferably styrene or α-methyl styrene (more preferably styrene), and the conjugated diene compound is preferably butadiene or isoprene. .

Specific examples of the component (A) include a styrene-(ethylene-propylene)-styrene type block copolymer (SEPS) (styrene-isoprene-styrene type) block copolymer ( Hydride of SIS), styrene-(ethylene-butylene)-styrene block copolymer (SEBS) (hydride of styrene-butadiene-styrene block copolymer (SBS)), XYX type tri-embedded styrene-(butadiene-butene)-styrene block copolymer (SBBS) (partial hydride of styrene-butadiene-styrene block copolymer (SBS)) Segment copolymer; styrene-(ethylene-propylene) block copolymer (SEP) (hydrogen adduct of styrene-isoprene type block copolymer (SI)), styrene-(ethylene-butyl Alkene type block copolymer (SEB) (hydrogen addition product of styrene-butadiene type block copolymer (SB)), etc. X-Y type diblock copolymer. In the component (A), these components may be used singly or in combination of two or more.

Further, the component (A) is an XYX-type triblock copolymer (hereinafter sometimes referred to simply as "triblock copolymer") and an XY-type diblock copolymer (hereinafter sometimes referred to simply as "diblock copolymer". When the mixture is a mixture, the content of the triblock copolymer is preferably 20% by mass or more and 95% by mass or less, more preferably 30% by mass or more and 90% by mass or less. Further, the content of the diblock copolymer is preferably 5% by mass or more and 80% by mass or less based on the mixture, and more preferably 10% by mass or more and 70% by mass or less.

As the component (A), a commercially available hydrogenated block copolymer such as SEP type Septon 1001 and 1020, SEPS type Septon 2002, 2004, 2005, 2006, 2007, 2063 and 2104, SEBS type Septon 8004 can be used. , 8006, 8007, 8076, and 8104 (Septon series are manufactured by Kuraray Co., Ltd.); Tuftec H1221, H1662, H1052, H1053, H1041, H1051, H1517, H1043, H1272 and N504 of SEBS type, Tuftec P1500, P2000 of SBBS type And JT83X (the above-mentioned Tuftec series are manufactured by Asahi Kasei Corporation).

The content of the hard segment (X: styrene) in the component (A) is preferably 10% by mass or more and 35% by mass or less, and more preferably 10% by mass or more, from the viewpoint of imparting heat resistance to the adhesive composition of the present embodiment. 20% by mass or less is more preferable. When the content of the hard segment (X) in the component (A) is less than 10% by mass, the heat resistance is inferior. On the other hand, when the content exceeds 35% by mass, the adhesive layer is too hard and adheres to the adherend. Sexual deterioration.

In addition, the degree of hydrogenation (hydrogenation rate) of the double bond contained in the polymer component of the conjugated diene monomer of the component (A) (hereinafter also referred to simply as "hydrogenation degree") is based on the viewpoint of excellent weather resistance. 90% or more is preferable, and more preferably 95% or more (and, although the degree of hydrogenation is preferably 100%, a trace amount (for example, 0.001% or more and 0.1% or less) of a double bond may be left). That is, in the present invention, the degree of hydrogenation of the double bond contained in the polymer component of the conjugated diene monomer means that the double bond contained in the polymer component of the conjugated diene monomer is saturated by hydrogenation. The ratio.

The weight average molecular weight of the component (A) in the adhesive composition of the present embodiment is 10,000 or more and 300,000 or less, from the viewpoint of imparting appropriate flexibility, flexibility, and step followability to the adhesive layer. It is better to use 50,000 or more and 300,000 or less. Further, when the component (A) is a mixture of the above triblock copolymer and the diblock copolymer, the weight average molecular weight of the component (A) means the weight average molecular weight of the mixture.

1.2. (B) ingredients

The component (B) is a liquid softener at normal temperature (23 ° C). The component (B) has a property compatible with the soft segment (Y) constituting the component (A). The component (B) contributes to the flexibility (wettability) of the adhesive composition of the present embodiment. Further, due to the factor (B), adhesion to the adherend and adhesion can be improved, and flexibility can be imparted to the adhesive layer obtained by using the composition.

Further, the "liquid" in the present invention contains a viscous viscoelastic liquid and other low viscosity liquids.

Further, whether or not the component (B) is compatible with the soft segment (Y) of the component (A) is a composition of a soft segment (Y) which conforms to the above component (A). The fraction, that is, the polymer synthesized from only the conjugated diene and the component (B) were evaluated.

More specifically, when a polymer obtained by polymerizing only a conjugated diene and a component (B) are mixed with a solvent to be used, turbidity occurs, or a phase containing the polymer is contained. When the phase separation from the phase containing the component (B) is not visually observed, the component (B) is considered to be compatible with the soft segment (Y) of the component (A), and on the other hand, the above turbidity or When the phase separation can be observed with the naked eye, the component (B) is considered to be incompatible with the soft segment (Y) of the above component (A).

Since the component (B) contained in the adhesive composition of the present embodiment is compatible with the soft segment (Y) of the component (A), the wettability of the adhesive layer is improved. The adhesiveness and adhesion to the adherend can be improved, and the adhesive layer obtained by using the composition can be made flexible.

The component (B) may be, for example, a softener containing an aliphatic hydrocarbon such as a polybutene compound, a polyisobutylene compound or a polyisoprene compound.

As the softener which can be used as the component (B), a commercially available softener such as Nisseki Polybutene LV-7, LV-50, LV-100, HV-15, HV-35 which is a polybutene compound, can be used. HV-50, HV-100, HV-300, HV-1900 and SV-7000 (all manufactured by JX Nippon Mining & Energy Co., Ltd.); Tetrax 3T, 4T, 5T and 6T, Himol 4H as polyisobutylene compounds, 5H, 5.5H and 6H (all manufactured by JX Nippon Mining & Energy Co., Ltd.); Kurapuren as a polyisoprene compound LIR-290 (manufactured by Kuraray Co., Ltd.) and the like. The component (B) may be used alone or in combination of two or more.

The content of the component (B) in the adhesive composition of the present embodiment is 10 parts by mass or more based on 100 parts by mass of the component (A), from the viewpoint of further improving the compatibility with the component (A). Preferably, it is more preferably 15 parts by mass or more, more preferably 20 parts by mass or more, and more preferably 300 parts by mass or less, more preferably 250 parts by mass or less, and even more preferably 200 parts by mass or less.

From the viewpoint of obtaining an adhesive layer having more excellent flexibility by using the adhesive composition of the present embodiment, the molecular weight (number average molecular weight) of the component (B) is preferably 5,000 or less, more preferably 500 or more and 3,000 or less.

1.3. (C) ingredients

The terpene-based tackifying resin as the component (C) is a tackifier resin derived from a terpene compound.

When the components (A) and (B) are mixed, the component (B) tends to move toward the surface of the adhesive layer. In the adhesive composition of the present embodiment, the component (B) can be prevented from moving toward the surface of the adhesive layer by blending the component (C). Further, the component (C) contributes to the improvement of the adhesiveness (adhesion and viscosity) of the adhesive composition of the present embodiment.

The terpene-based tackifying resin as the component (C) has a property compatible with the component (A). More specifically, the component (C) is compatible with both the hard segment (X) and the soft segment (Y) constituting the component (A).

(C) component and hard segment (X) and film constituting component (A) Whether or not the segment (Y) is compatible, is a component which satisfies the hard segment (X) of the above-mentioned composition (A), that is, a polymer synthesized only from an aromatic vinyl monomer, and conforms to the above constitution The component of the soft segment (Y) of the component (A), that is, the polymer synthesized only from the conjugated diene monomer, and the component (C) were evaluated.

More specifically, (i) a polymer synthesized only from an aromatic vinyl monomer which conforms to the hard segment (X) constituting the component (A) and a component (C) are mixed with a solvent if necessary. a mixture, (ii) a mixture of a polymer synthesized only from a conjugated diene monomer and a component (C) which is a soft segment (Y) constituting the component (A), if necessary, a solvent, (iii) When the component (A) and the component (C) are mixed with a solvent if necessary, when the occurrence of turbidity or phase separation cannot be observed with the naked eye, it is considered that the component (C) is compatible with the component (A). On the other hand, when turbidity or phase separation can be observed with the naked eye in any of the above (i) to (iii), it is considered that the component (C) is incompatible with the component (A).

Further, the component (C) is preferably one having a property compatible with the component (B).

More specifically, in the mixture obtained by mixing the component (B) and the component (C) with a solvent, if necessary, the occurrence of turbidity or the phase containing the component (B) and the component containing (C) cannot be observed with the naked eye. When the phase of the phase is separated, it is considered that the component (C) is compatible with the component (B). On the other hand, when the turbidity or phase separation can be observed with the naked eye, it is considered that the component (C) is not in phase with the component (B). Rong.

For the component (C), for example, YS resin PX1250 (softening point 125±5 ° C), YS resin PX1150 (softening point 115±5) can be used. °C), YS resin PX1000 (softening point 100±5°C), YS resin PX1150N (softening point 115±5°C), YS Polystar U130 (softening point 130±5°C), YS Polystar U115 (softening point 115±5°C) YS Polystar T160 (softening point 160±5°C), YS Polystar T145 (softening point 145±5°C), YS Polystar T130 (softening point 130±5°C), YS Polystar T115 (softening point 115±5°C), YS Polystar T100 (softening point 100±5°C), YS Polystar S145 (softening point 145±5°C), YS Polystar G150 (softening point 150±5°C), YS Polystar G125 (softening point 125±5°C), YS Polystar N125 (softening point 125±5°C), YS Polystar K140 (softening point 140±5°C), YS Polystar K125 (softening point 125±5°C), YS Polystar TH130 (softening point 130±5°C), YS Polystar UH115 (softening) Point 115±5°C), Clearon P150 (softening point 152±5°C), Clearon P135 (softening point 135±5°C), Clearon P125 (softening point 125±5°C), Clearon P115 (softening point 115±5°C) , Clearon P105 (softening point 105 ± 5 ° C), Clearon M125 (softening point 125 ± 5 ° C), Clearon M115 (softening point 115 ± 5 ° C), Clearon M105 (softening point 105 ± 5 ° C), Clearon K100 (softening point) 100±5°C), Cleanon K4100 ( 100100±5°C), YS resin TO125 (softening point 125±5°C), YS resin TO115 (softening point 115±5°C), YS resin TO105 (softening point 105±5°C) and YS resin TR105 (softening point) 105±5°C) (all manufactured by Yasuhara). The component (C) may be used singly or in combination of two or more.

The content of the component (C) in the adhesive composition of the present embodiment is 1 part by mass or more based on 100 parts by mass of the component (A), from the viewpoint of further improving the compatibility with the component (A). Good, in 3 parts by mass More preferably, it is more preferably 5 parts by mass or more, and more preferably 30 parts by mass or less, more preferably 25 parts by mass or less, even more preferably 20 parts by mass or less.

From the viewpoint of more effectively suppressing the deterioration of the adhesive strength in the adhesive composition of the present embodiment, the content of the component (C) relative to the content of the component (B) (the content of the component (C) / (B) The content of the component is preferably 0.05 or more, more preferably 0.07 or more, still more preferably 0.10 or more, and further preferably 0.70 or less, more preferably 0.60 or less, and still more preferably 0.50 or less.

In the adhesive composition of the present embodiment, the sum of the content of the component (B) and the content of the component (C) can be further improved from the viewpoint of improving the compatibility of the component (A), the component (B) and the component (C). With respect to 100 parts by mass of the component (A), it is preferably 11 or more, more preferably 18 or more, and still more preferably 25 or more. On the other hand, preferably 330 or less, more preferably 275 or less, and 220 or more. The following is even better.

Further, in the adhesive composition of the present embodiment, the content of the component (B) and the content of the component (C) can be further improved from the viewpoint of improving the compatibility of the component (D), the component (B) and the component (C). The sum of the components (D) may be 0.5 or more and 10.0 or less, preferably 0.7 or more, more preferably 0.8 or more, and more preferably 9.0 or less, more preferably 8.0 or less.

From the viewpoint of imparting high adhesion, the softening point of the component (C) is preferably 100 ° C or more, more preferably 120 ° C or more, and still more preferably 145 ° C or more (generally 300 ° C or less).

From the viewpoint of further improving compatibility, (C) The weight average molecular weight is preferably 200 or more and 5,000 or less.

1.4. (D) component

The aromatic tackifying resin (the tackifying resin having an aromatic ring) as the component (D) has a property compatible with the hard segment (X) of the composition (A), and the softening point is 80 ° C or higher. . The component (D) contributes to the improvement of the cohesiveness and adhesiveness (adhesion) of the adhesive composition of the present embodiment.

Further, whether or not the component (D) is compatible with the hard segment (X) constituting the component (A) is a component which satisfies the hard segment (X) constituting the component (A), that is, only an aromatic vinyl group. The polymer synthesized by the monomer is evaluated in accordance with the component (D).

More specifically, in the mixture obtained by mixing only the polymer obtained by polymerizing the aromatic vinyl monomer and the component (D) with a solvent if necessary, the occurrence of turbidity or the presence of the polymer cannot be observed with the naked eye. When the phase is separated from the phase containing the component (D), the component (D) is compatible with the hard segment (X) constituting the component (A), and on the other hand, the turbidity or phase separation can be observed with the naked eye. In the case, the component (D) is incompatible with the hard segment (X) constituting the component (A).

Since the component (D) contained in the adhesive composition of the present embodiment is compatible with the hard segment (X) constituting the component (A), the adhesive layer formed of the adhesive composition is imparted. A certain degree of hardness can improve the heat resistance and adhesion of the adhesive layer.

Examples of the compound which can be used as the component (D) include aromatic petroleum resins, styrene polymers, α-methylstyrene polymers, and styrene-(α-methylstyrene) copolymers. Styrene-aliphatic hydrocarbon A copolymer, a styrene-(α-methylstyrene)-aliphatic hydrocarbon copolymer, a styrene-aromatic hydrocarbon copolymer, and the like. More specifically, for example, FMR-0150 (softening point 145 ° C, manufactured by Mitsui Chemicals, Inc.) of a commercially available styrene-aromatic hydrocarbon copolymer; FTR of a styrene-aliphatic hydrocarbon copolymer may also be used. 6100 (softening point 100 ° C, manufactured by Mitsui Chemicals Co., Ltd.), FTR-6110 (softening point 110 ° C, manufactured by Mitsui Chemicals, Inc.) and FTR-6125 (softening point 125 ° C, manufactured by Mitsui Chemicals, Inc.); styrene-(α-甲Ftyrene-based aliphatic hydrocarbon copolymer FTR-7100 (softening point 100 ° C, manufactured by Mitsui Chemicals Co., Ltd.); styrene copolymer FTR-8120 (softening point 120 ° C, manufactured by Mitsui Chemicals, Inc.) and SX- 100 (softening point 100 ° C, manufactured by Yasuhara Chemical Co., Ltd.); FTR-0100 of α-methylstyrene copolymer (softening point 100 ° C, manufactured by Mitsui Chemicals, Inc.); styrene-(α-methylstyrene) system Copolymer FTR-2120 (softening point 120 ° C, manufactured by Mitsui Chemicals Co., Ltd.), FTR-2140 (softening point 145 ° C, manufactured by Mitsui Chemicals, Inc.), Christa Rex 3100 (softening point 100 ° C, manufactured by Eastman Chemical Co., Ltd.), Christa Rex 3085 (softening point 85 ° C, manufactured by Eastman Chemical Co., Ltd.), Christa Rex 5140 (softening point 140 ° C , manufactured by Eastman Chemical Co., Ltd., Christa Rex 1120 (softening point 120 ° C, manufactured by Eastman Chemical Co., Ltd.), Christa Rex F85 (softening point 85 ° C, manufactured by Eastman Chemical Co., Ltd.), Christa Rex F100 (softening point 100 ° C, manufactured by Eastman Chemical Co., Ltd.) And Christa Rex F115 (softening point 115 ° C, manufactured by Eastman Chemical Co., Ltd.) and the like. The component (D) may be used singly or in combination of two or more.

Adhesive composition of the present embodiment is endowed with durability The softening point of the component (D) is preferably 80 ° C or more, more preferably 100 ° C or more, and even more preferably 120 ° C or more.

From the viewpoint of good compatibility and adhesion, the weight average molecular weight of the component (D) is preferably 5,000 or less, more preferably 500 or more and 3,000 or less.

The content of the component (D) in the adhesive composition of the present embodiment is preferably 1 part by mass or more based on 100 parts by mass of the component (A), from the viewpoint of the compatibility with the component (A). It is more preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and more preferably 50 parts by mass or less, more preferably 40 parts by mass or less, still more preferably 30 parts by mass or less.

Further, in the adhesive composition of the present embodiment, the total content of the component (A), the component (B), the component (C), and the component (D) is preferably 70% by mass or more, more preferably 80% by mass or more. (generally 100% by mass or less).

1.5. Form of composition

The adhesive composition of the present embodiment can be used by being dissolved in a solvent. The solvent is preferably, for example, at least one selected from the group consisting of aliphatic hydrocarbons and/or aromatic hydrocarbons which are liquid at 23 ° C.

Examples of the aliphatic hydrocarbon which can be used as a solvent include linear chains such as n-pentane, methylpentane, n-hexane, isohexane, n-heptane, isoheptane, n-octane, and isooctane, or Branched chain aliphatic hydrocarbon; cyclic aliphatic hydrocarbon such as cyclopentane, cyclohexane and methylcyclohexane.

Further, examples of the aromatic hydrocarbon which can be used as a solvent include, for example, toluene, benzene, o-xylene, m-xylene, p-xylene, ethylbenzene, mesitylene, chlorobenzene and nitro group. benzene. Solvent One or two of an aliphatic hydrocarbon and an aromatic hydrocarbon may be used in combination. Further, the adhesive composition of the present embodiment may contain a solvent other than an aliphatic hydrocarbon or an aromatic hydrocarbon (for example, an ester solvent such as ethyl acetate, methyl acetate or butyl acetate; methyl ethyl ketone and A ketone solvent such as acetone; an organic solvent generally used in an adhesive such as tetrahydrofuran or acetonitrile).

The content of the solvent is preferably 1,000% by mass or less, and more preferably 900% by mass or less based on 100 parts by weight of the total of the adhesive composition of the present embodiment.

1.6. Relative dielectric constant

The relative dielectric constant of the adhesive layer obtained from the adhesive composition of the present embodiment is the value of the relative dielectric constant measured at a frequency of 100 Hz. The adhesive layer obtained from the optical adhesive composition of the present embodiment has a relative dielectric constant of 1 or more and 3.5 or less, preferably 1 or more and 3.2 or less, more preferably 1 or more and 2.8 or less.

As described above, since the adhesive layer obtained from the optical adhesive composition of the present embodiment exhibits a low relative dielectric constant in a wide band, the image display device or the output/input device provided with the adhesive layer can prevent high frequency. The operation of the pulse is incorrect.

1.7. Water vapor barrier

The adhesive layer formed of the adhesive composition of the present embodiment has excellent water vapor barrier properties. More specifically, in the adhesive composition of the present embodiment, the water vapor permeability of the adhesive layer having a thickness of 50 μm obtained from the adhesive composition may be JIS Z0208 or 40 ° C × 90% RH. Not up to 100g/m ² . Japanese, to less than 70g / m ² . The Japanese are better, not to reach 50g/m ² . The day is better, to less than 40g/m ² . The day (generally 1 × 10 ^-4 g / m ² . day or more) is even better.

In the present invention, the "water vapor transmission rate of the adhesive layer" means the measured value of the water vapor permeability of the adhesive single layer having a film thickness of 50 μm in Z0208 and 40 ° C × 90% RH (g/m). ^2. Day).

1.8. Persistence of adhesion

The adhesive layer (adhesive sheet) formed of the adhesive composition of the present embodiment also has a property that the adhesive sheet is less likely to deteriorate over time even if it has been stored for a long period of time. More specifically, the adhesive layer of the film thickness of 50 μm formed by the adhesive composition of the present embodiment is placed at 60 ° C in a dry environment for one month, and the adhesive force is compared with that before being placed in the environment. The adhesion of the adhesive layer is 80% or more, preferably 90% or more.

1.9. Use

The use of the adhesive composition of the present embodiment is intended to be used for the purpose of ensuring adhesion, transparency, flexibility, flexibility, step followability, gas barrier properties such as water vapor, or resistance to moist heat whitening. There is no special limit. For example, it can be used in adhesive sheets, adhesive tapes, labels, pressure sensitive sheets, surface protective films/sheets or optical applications.

The member to be bonded to the adhesive composition of the present embodiment may be, for example, an optical member (for example, selected from the group consisting of a polarizing film, a retardation film, an elliptically polarizing film, an antireflection film, a brightness enhancement film, and light). A metal film such as a group of a diffusion film and a hard coat film), a metal layer such as an ITO layer, or a substrate containing glass or plastic.

More specifically, the adhesive group of the present embodiment can be used. The object is used for bonding of a member constituting an image display device (organic EL display) or an input/output device including a touch panel.

In recent years, there has been a problem of operational errors in the operation of the touch. Since the adhesive layer obtained from the adhesive composition of the present embodiment has a low relative dielectric constant, it can prevent the operation of the touch panel during operation when used in the bonding of the members constituting the touch panel type input/output device. Mistakes.

Further, for example, since the organic EL element and the organic thin film solar cell are easily affected by moisture, it is required that the adhesive/adhesive resin material used in such an organic EL element and an organic thin film solar cell has high water vapor barrier property. . On the other hand, since the adhesive layer formed of the adhesive composition of the present embodiment has water vapor barrier properties, it can be prevented by being used in applications such as organic EL devices and organic thin film solar cells that are vulnerable to water. Infiltration of water.

1.9.1. Touch panel use

An example of the adhesive layer (adhesive sheet) obtained by using the adhesive composition of the present embodiment in the bonding of the members constituting the touch panel type input/output device will be described with reference to Fig. 1 .

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

The adhesive layer 30 is, for example, an adhesive of the embodiment. The composition is coated on a surface of a separator (not shown) and dried, and the adhesive sheet is peeled off from the separator and disposed between the LCD 10 and the touch panel portion 20.

Further, as shown in Fig. 1, the LCD 10 has a laminated 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 adhesive layer 12 is such that the polarizing plate 11 and the liquid crystal panel 13 are bonded to each other, and the adhesive layer 14 is such that the liquid crystal panel 13 and the polarizing plate 15 are bonded to each other.

Further, as shown in FIG. 1, the touch panel unit 20 is configured by laminating the shatterproof film 16, the adhesive layer 17, the ITO layer 18, and the glass panel 19 in this order. The adhesive layer 17 is such that the shatterproof film 16 is bonded to the ITO layer 18.

The adhesive layers 12, 14 and 17 are the same as the adhesive layer 30, and may be an adhesive sheet obtained by applying the adhesive composition of the present embodiment to the surface of a separator (not shown) to dry the volatile components. The set is peeled off from the separator.

1.9.2. Use of water vapor barrier laminates

The adhesive layer (adhesive sheet) obtained from the adhesive composition of the present embodiment can be used for the use of a water vapor barrier laminate. In other words, the laminate of one embodiment of the present invention may comprise an adhesive layer and a barrier film obtained from the adhesive composition of the present embodiment.

Fig. 2, Fig. 3, and Fig. 4 are each a schematic cross-sectional view showing an example of an adhesive water vapor barrier layered product of the present embodiment.

Adhesive water vapor barrier layered body shown in Fig. 2 The 110 series includes a substrate 1 and an adhesive layer 2 provided on the substrate 1 (the surface of the substrate 1). The material of the substrate 1 may be an inorganic material such as glass; or an organic material represented by plastics such as polyethylene, polypropylene, polyethylene terephthalate, polymethyl methacrylate, polyester, and polycarbonate. material. Further, Fig. 2 shows a case where the substrate 1 is a single layer.

Alternatively, the substrate 1 may be an inorganic material (for example, at least one layer selected from the group consisting of oxides, nitrides, or oxynitrides of Si, Al, In, Sn, Zn, and Ti).

The adhesive water vapor barrier laminate 120 shown in FIG. 3 includes a substrate 111 and an adhesive layer 2 provided on the surface of the substrate 111. Fig. 3 shows an example in which the substrate 111 is composed of a plurality of layers. That is, as shown in FIG. 3, the substrate 111 includes a first layer 21, another layer (the second layer 22) provided on the surface of the first layer 21, and an adhesive layer 2 may be disposed on the second layer 22. .

The material of the first layer 21 may be an inorganic material such as glass or the like, or an organic material such as the above-exemplified plastics of the substrate 1. The material of the second layer 22 is not particularly limited, and may be an inorganic barrier material such as a metal such as a metal, cerium oxide, cerium oxynitride or tantalum nitride, or may be a plastic or the like exemplified as the substrate 1 described above. organic material.

More specifically, the first layer 21 or the second layer 22 may be an inorganic material (for example, at least one layer selected from the group consisting of oxides, nitrides, or oxynitrides of Si, Al, In, Sn, Zn, and Ti ( For example, a vapor deposited film deposited on an organic film or the like)).

Further, in Fig. 3, an example in which the adhesive layer 2 is provided on the second layer 22 of the substrate 111 is shown, but in the first layer 21 of the substrate 111, The adhesive layer 2 is provided on the reverse side of the side on which the second layer 22 is provided, and the adhesive layer 2 may be provided between the first layer 21 and the second layer 22.

The fourth drawing shows an example in which the laminated body 130 as an image display device includes the organic EL element 3. In other words, the laminated body 130 shown in FIG. 4 includes the substrate 1, the organic EL element 3 provided on the substrate 1, and the adhesive layer provided on the substrate 1 so as to cover the organic EL element 3. 2.

According to the laminated body 130 shown in Fig. 4, the adhesive layer 2 is provided so as to cover the organic EL element 3, whereby the organic EL element 3 is sealed, so that the vapor of the organic EL element 3 can be blocked.

According to the laminates 110, 120, and 130 of Figs. 2, 3, and 4, water vapor can be blocked from infiltrating from the end faces of the adhesive layer 2 (the lateral direction of the paper of Figs. 2, 3, and 4). . Further, in the laminated bodies 110, 120, and 130, for example, in the middle of the manufacturing step of the laminated body, no other layer is provided on the surface of the adhesive layer 2, and the surface of the adhesive layer 2 may be blocked from water vapor. Infiltration with the vertical direction (the longitudinal direction of the paper in Figs. 2, 3, and 4).

The adhesive layer 2 of Fig. 2, Fig. 3, and Fig. 4 can be formed by directly applying an adhesive composition described later on the surface of the substrate 1 or the substrate 111, but it can also be formed in the peeling. The adhesive layer 2 on the film is transferred to the surface of the substrate 1 or the substrate 111, whereby the adhesive layer 2 is formed on the surface of the substrate 1 or the substrate 111. The water vapor permeability of the substrate 1 or the substrate 111 may be less than 30 g/m ² in JIS Z0208, 40 ° C × 90% RH (wet cup method) (1976 edition). The day is less than 10g/m ² . The day is better, less than 1g/m ² . Better day (generally 1 × 10 ^-6 g / m ² . day or more). For example, when the water vapor permeability of the substrate 1 and 111 is lower than the water vapor permeability of the adhesive layer 2 (more specifically, when the substrate 1 and 111 have water vapor barrier properties (that is, as water) In the vapor barrier film)), the adhesive layer of the present invention can suppress the infiltration of water from the end faces, and therefore, the water vapor permeability of the laminates 110, 120, and 130 can actually become the water vapor of the substrate 1, 111. Penetration rate.

The film thickness of the base material 1 and 111 is generally 1 μm or more and 500 μm or less, and preferably 5 μm or more and 200 μm or less.

Further, when the adhesive water vapor barrier layered product of the present embodiment has transparency (for example, the total light transmittance of the adhesive water vapor barrier layered product of the present embodiment is JIS K7361 (1997 edition)) When it is 85% or more, the total light transmittance of the base materials 1 and 111 is preferably 85% or more (generally 100% or less) in the JIS K7361 method, and more preferably 87% or more.

1.10. Effect

In the first embodiment, the adhesive composition of the present embodiment prevents the component (B) from moving toward the surface of the adhesive layer due to the component (C), and suppresses the elapsed time of the adhesive sheet obtained from the adhesive composition during long-term storage. Deterioration.

In the second embodiment, the adhesive composition of the present embodiment has low polarity and is hydrophobic. Therefore, the adhesive layer formed of the adhesive composition has a low relative dielectric constant and excellent water vapor barrier properties.

In the adhesive composition of the third embodiment, the adhesive layer formed of the adhesive composition has flexibility (wettability) and flexibility due to the factor (B), so the step followability Excellent.

According to the fourth aspect, the adhesive composition of the present embodiment is provided with the component (C) and the component (D), and the adhesive composition is provided. The adhesion layer of the formed adhesive layer and the adhesion are excellent in stability over time.

The fifth adhesive layer obtained from the adhesive composition of the present embodiment has durability due to factors (A), (C) and (D).

As described above, the adhesive layer formed of the adhesive composition of the present embodiment suppresses deterioration of the adhesive strength of the adhesive sheet obtained by the adhesive composition over a long period of time, and has a low relative dielectric constant. Excellent in water vapor barrier properties, flexibility, flexibility, step followability, adhesion and durability. Therefore, it can be applied to, for example, a touch panel type output input device or an organic EL display or the like.

2. Adhesive layer (adhesive sheet) and manufacturing method thereof

An adhesive layer (adhesive sheet) according to an embodiment of the present invention is obtained by drying a film formed of the adhesive composition of the present embodiment. More specifically, the adhesive layer (adhesive sheet) of one embodiment of the present invention contains 100 parts by mass of the component (A), 10 parts by mass or more and 300 parts by mass or less of the component (B), and 1 part by mass or more of the component (C). 30 parts by mass or less and (D) component 1 part by mass or more and 50 parts by mass or less. Here, the content of the component (C) / the content of the component (B) is 0.05 or more and 0.70 or less.

The adhesive layer of the present embodiment can be obtained by dissolving the adhesive composition of the above embodiment in a solvent, and then removing the solvent. That is, the method for producing an adhesive layer (adhesive sheet) according to an embodiment of the present invention includes a step of applying a pressure-sensitive adhesive composition of the above-described embodiment dissolved in a solvent to a substrate to obtain a film, and The step of obtaining an adhesive layer by drying the film to remove the solvent.

For example, the adhesive composition of the present embodiment dissolved in a solvent is applied to the surface of a release substrate (separator), and the adhesive of the embodiment can be obtained by, for example, maintaining the separator at an evaporation temperature by a solvent. Layer (adhesive sheet).

More specifically, the adhesive composition of the present embodiment dissolved in a solvent is coated on a release substrate by a gravure coater, a bar coater, an air knife coater, a roll coater or the like. The cloth can be prepared by holding the applied adhesive composition at a normal temperature (for example, 15° C. or higher and 40° C. or lower) or by appropriately heating (for example, 40° C. or higher and 200° C. or lower). Form of adhesive layer.

Alternatively, the adhesive layer of the present embodiment can be produced by directly applying the adhesive composition of the present embodiment to the adherend.

In the adhesive layer of the present embodiment, the total light transmittance can be 85% or more in the JIS K7361 method from the viewpoint of excellent transparency, and more preferably 90% or more.

Further, the adhesive layer of the present embodiment may have a storage elastic modulus at 25 ° C and 1 Hz from 1 × 10 ⁴ Pa to 2 × 10 ⁶ Pa or less, from the viewpoint of excellent durability and flexibility. It is preferable that 10 ⁴ Pa or more and 1 × 10 ⁶ Pa or less.

The thickness of the adhesive layer of the present embodiment is generally 10 μm or more and 500 μm or less, and preferably 20 μm or more and 300 μm or less.

3. Embodiment

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

3.1. Modulation of adhesive composition

The components of Examples 1 to 12 and Comparative Examples 1 to 3 were prepared by mixing the components in the formulations shown in Table 1.

In other words, the component (A) and the other components were dissolved in a solvent (150 parts by mass of toluene) to prepare the adhesive compositions of Examples 1 to 12 and Comparative Examples 1 to 3, respectively.

In the adhesive compositions of Examples 1 to 12, solids were not visible to the naked eye in the adhesive composition, and dull or white turbidity did not occur in the adhesive composition, and more, when filtered with a mesh filter of 1 μm. It does not cause clogging and confirms that there is no residue on the filter paper. Thus, it was confirmed that the components (A), (B), (C) and (D) in the adhesive compositions of Examples 1 to 12 and Comparative Examples 1 to 3 were dissolved in a solvent.

3.2. Manufacture of adhesive sheets for evaluation

The adhesive composition solution obtained in the examples and the comparative examples was applied to the peeled polyethylene terephthalate film so that the film thickness after drying became 50 μm, and the organic film was removed by a dryer at 90 ° C. Solvent (toluene). Then, the peeled polyethylene terephthalate film was bonded to the coated surface of the pressure-sensitive adhesive layer to obtain an evaluation adhesive sheet having a film thickness of 50 μm.

3.3. Assessment method

3.3.1. Adhesion

(initial)

The evaluation adhesive with a film thickness of 50 μm was obtained by the method described in the above column 3.2. The sheet was peeled off, and the polyethylene terephthalate film on one side was peeled off, and bonded to a polyethylene terephthalate film having a thickness of 100 μm, and cut into a test piece of 25 mm in width.

The peeled polyethylene terephthalate film of the glass piece was peeled off, and the exposed adhesive coated surface was pressure-bonded to the glass with a roll of 2 kg. After bonding for 20 minutes, the adhesive sheet was peeled off from the glass plate (23° C., peeling angle 180, peeling speed: 300 mm/min), and the initial adhesion was measured.

(after aging)

An evaluation adhesive sheet having a thickness of 50 μm was obtained by the method described in the above section 3.2. The polyethylene terephthalate film on one side was peeled off and bonded to a polyethylene terephthalate film having a thickness of 100 μm. The test piece was cut into a width of 25 mm.

The obtained test piece was allowed to stand at 60 ° C for 1 month in a dry environment, and then left to stand in an environment of 23 ° C × 50% RH for 1 hour, and then the peeled polyethylene terephthalate film of the test piece was peeled off. The exposed adhesive coated surface was crimped to the glass with a 2 kg roller. After bonding for 20 minutes, the adhesive sheet was peeled off from the glass plate (23° C., peeling angle: 180°, peeling speed: 300 mm/min), and the adhesive force after aging was measured.

3.3.2. Step followability

The evaluation adhesive sheet having a film thickness of 50 μm was transferred to a polyethylene terephthalate film having a thickness of 100 μm by the method described in the above section 3.2. to obtain an evaluation test piece cut into 50 mm × 50 mm.

Then, a polyethylene terephthalate film having a film thickness of 25 μm cut into 15 mm × 15 mm was placed on a glass plate, and the glass layer was coated with an adhesive layer. The test piece (50 mm × 50 mm) was attached to the entire surface of the polyethylene terephthalate film (15 mm × 15 mm) on the glass plate, and subjected to autoclaving (50 ° C, 5 atm, 20 minutes) at room temperature. After being left for 1 hour, the appearance of the step portion was observed with the naked eye.

Based on the above, the step followability of the adhesive layer obtained from the adhesive composition was evaluated according to the following criteria.

(assessment)

○: No voids or bubbles were observed by the naked eye in the step portion of the bonding.

△: A small amount of voids or bubbles were visually observed in the step portion of the fit.

×: Obvious voids or bubbles were observed in the step portion of the fit.

3.3.3. Initial viscosity (probe viscosity)

An evaluation adhesive sheet having a thickness of 50 μm was obtained by the method described in the above section 3.2. The polyethylene terephthalate film on one side was peeled off and bonded to a polyethylene terephthalate film having a thickness of 100 μm. A test piece was prepared, and the peeled polyethylene terephthalate film of the test piece was peeled off, and the adhesive viscosity of the exposed adhesive-coated surface was measured. The probe was SUS having a diameter of 5 mm, the contact time was 1 second, the probe speed was 1 cm/sec, and the load was 20 g.

3.3.4. Water vapor transmission rate

The water vapor transmission rate was carried out in accordance with JIS Z0208. That is, an adhesive sheet for evaluation having a film thickness of 50 μm was obtained by the method described in the above column 3.2, and the polyethylene terephthalate film on both sides thereof was peeled off, and after bonding with the non-woven fabric, about 10 g of calcium chloride was contained. On the moisture permeable cup (inner diameter 60 mm), the adhesive sheet was evaluated by a non-woven fabric, and the periphery was sealed. Then, the moisture permeable cup was allowed to stand in an environment of 40 ° C × 90% RH for measurement.

3.3.5. Storage elastic modulus

The evaluation adhesive sheets having a film thickness of 50 μm obtained by the method described in the above section 3.2. were bonded to each other several times in an environment of 23 ° C × 50% RH, and treated in an autoclave at 50 ° C × 5 atm for 20 minutes to prepare a thickness of 1.0 mm. Adhesive layer. For the adhesive layer having a thickness of 1.0 mm, "Physica MCR300" manufactured by Anton Paar Co., Ltd., according to the dynamic viscoelasticity measurement method of JIS K7244 (temperature range -40 ° C to 160 ° C, temperature increase rate 3.67 ° C / minute, frequency 1 Hz) Condition) The viscoelastic spectrum was determined to determine the storage elastic modulus at a temperature of 25 °C.

3.3.6. Relative dielectric constant

The evaluation adhesive sheet having a film thickness of 50 μm obtained by the method described in the above section 3.2. was adhered to a copper foil having a thickness of 100 μm, and further adhered to a copper foil having a thickness of 100 μm to prepare a test sample. Copper/platinum was connected using an LCR tester 6440B manufactured by Toyo Corporation, and the relative dielectric constant was determined under the conditions of a frequency of 100 Hz and 23 ° C × 65% RH.

3.3.7. Total light transmittance

An evaluation adhesive sheet having a film thickness of 50 μm was obtained by the method described in the above section 3.2. The polyethylene terephthalate film on one side was peeled off, and glass was placed on it to prepare a test piece. After the test piece was autoclaved (50 ° C, 5 atm, 20 minutes), the other side of the polyethylene terephthalate film was removed, and the total light transmittance of the adhesive layer was measured by haze (model name "HM" -150", manufactured by Murakami Color Technology Research Institute Co., Ltd.).

Further, each component used in the examples and comparative examples is as follows.

▪ (A) component

Polymer 1: a mixture of SEP (50% by mass) and SEPS (50% by mass)

(styrene content 15% by mass, weight average molecular weight 150,000)

Polymer 2: a mixture of SEP (50% by mass) and SEPS (50% by mass)

(styrene content 20% by mass, weight average molecular weight 170,000)

Polymer 3: a mixture of SEP (60% by mass) and SEPS (40% by mass)

(styrene content 15% by mass, weight average molecular weight 130,000)

Polymer 4: a mixture of SEP (30% by mass) and SEPS (70% by mass)

(styrene content 15% by mass, weight average molecular weight 200,000)

Polymer 5: a mixture of SEP (60% by mass) and SEPS (40% by mass)

(styrene content: 35 mass%, weight average molecular weight: 130,000)

Further, the degree of hydrogenation of SEP and SEPS used in the polymers 1 to 5 was 90% or more.

▪ (B) ingredients

LV-100: Polybutene (Mn=500) (manufactured by JX Nippon Mining & Energy Co., Ltd.)

HV-300: Polybutene ((Mn=1,400)) (manufactured by JX Nippon Mining & Energy Co., Ltd.)

▪ (C) ingredients

P-150: terpene resin having a softening point of 152 ± 5 ° C (manufactured by Yasuhara Chemical Co., Ltd.)

TH-130: terpene type tackifying resin with a softening point of 130±5°C (manufactured by Yasuhara Chemical Co., Ltd.)

▪ (D) component

FMR-0150: Aromatic tackifying resin with a softening point of 145 ° C (manufactured by Mitsui Chemicals Co., Ltd., weight average molecular weight: 2,040)

FMR-6100: Aromatic tackifying resin with a softening point of 100 ° C (manufactured by Mitsui Chemicals Co., Ltd., weight average molecular weight: 1,210)

▪ Solvent

Toluene (made by Sankyo Chemical Co., Ltd.)

3.4. Assessment results

As is apparent from the results of Table 1, the adhesive compositions of Examples 1 to 12 of the present invention contained the components (A), (B), (C) and (D), and the content of the component (B). The content of the component (C) (the content of the component (C) / the content of the component (B)) is 0.05 or more and 0.70 or less, whereby the adhesive force can be maintained for a long period of time, and high transparency and a low dielectric constant are obtained. Further, an adhesive layer excellent in adhesion, weather resistance, flexibility, flexibility, viscosity, step followability, and wet heat whitening resistance can be obtained.

On the other hand, as shown in Table 1, it can be understood that the composition of Comparative Example 1 of the present invention is inferior in step followability because it does not contain the component (B). Further, the adhesive sheet obtained by using the adhesive layer obtained from the composition of Comparative Example 1 of the present invention had a low adhesiveness, and it was impossible to bond the adhesive sheet having a thickness of 50 μm to the thickness of 1 mm. Further, it can be understood that the composition of Comparative Example 2 of the present invention deteriorates the adhesion over time due to the absence of the component (C). Further, it can be understood that the composition of Comparative Example 3 of the present invention is inferior in adhesion due to the absence of the component (D).

Further, the entire light of the above-mentioned adhesive layer formed of the adhesive compositions of Examples 1 to 12 measured by the above evaluation method The light rate is 92%. Thus, it can be understood that the above-mentioned adhesive layer formed of the adhesive compositions of Examples 1 to 12 is excellent in transparency.

10‧‧‧Liquid Crystal Display Unit (LCD)

11, 15‧‧‧ polarizing plate

12, 14, 17, 30‧‧‧ adhesive layer

13‧‧‧LCD panel

16‧‧‧Smashproof film

18‧‧‧ITO layer

19‧‧‧ glass panel

20‧‧‧Touch Panel Department

100‧‧‧Touch panel type input input device

Claims (11)

An adhesive composition comprising: (A) a block copolymer selected from at least one of an XYX-type hydrogenated styrene block copolymer and an XY-type hydrogenated styrene block copolymer; (B) a room temperature (23) C is a liquid softener, (C) a terpene-based tackifying resin, and (D) an aromatic tackifying resin, each of which contains 100 parts by mass of the block copolymer (A). (B) the softening agent: 10 parts by mass or more and 300 parts by mass or less, (C) the terpene-based tackifying resin: 1 part by mass or more and 30 parts by mass or less, and the (D) aromatic-based tackifying resin: 1 part by mass or more and 50 parts by mass In the following, and the content of the (C) terpene-based tackifying resin relative to the content of the (B) softening agent (the content of the (C) terpene-based tackifying resin / the content of the aforementioned (B) softening agent ) is 0.05 or more and 0.70 or less. The adhesive composition according to claim 1, wherein the (A) block copolymer is a mixture of an X-Y-X type hydrogenated styrene block copolymer and an X-Y type hydrogenated styrene block copolymer. The adhesive composition according to claim 1 or 2, wherein the styrene content of the (A) block copolymer is 10% by mass or more and 35% by mass or less. The adhesive composition according to any one of claims 1 to 3, wherein any one of claims 1 to 3 is The adhesive layer obtained by the adhesive composition has a relative dielectric constant of 1 or more and 3.5 or less. The adhesive composition according to any one of claims 1 to 4, wherein the adhesive of the adhesive composition according to any one of claims 1 to 4 has a film thickness of 50 μm. The water vapor transmission rate of the agent layer is less than 100 g/m ² in JIS Z0208, 40 ° C × 90% RH. day. The adhesive composition according to any one of claims 1 to 5, which is used for constituting a member of a touch panel type input/output device. The adhesive composition according to any one of claims 1 to 5, which is used for constituting a member of an organic EL display. A laminate comprising an adhesive layer and a barrier film obtained from the adhesive composition according to any one of claims 1 to 5. An adhesive sheet obtained by drying a film formed of the adhesive composition according to any one of claims 1 to 5. An image display device comprising an adhesive layer formed using the adhesive composition according to any one of claims 1 to 5. An output input device comprising an adhesive layer formed using the adhesive composition according to any one of claims 1 to 5.