KR102116598B1 - Adhesive composition, adhesive sheet, stacked body, image display device, and input/output device - Google Patents

Abstract

The pressure-sensitive adhesive composition includes (A) at least one block copolymer selected from XYX-type hydrogenated styrenic block copolymers and XY-type hydrogenated styrenic block copolymers, (B) a softener that is liquid at room temperature (23 ° C), (C) terpene tackifying resin and (D) aromatic tackifying resin, the (A) block copolymer 100 parts by weight, respectively, (B) the softener is 10 parts by mass or more and 300 parts by mass It contains below, said (C) terpene tackifying resin contains 1 mass part or more and 30 mass parts or less, said (D) aromatic type tackifying resin contains 1 mass part or more and 50 mass parts or less, and also said (B ) The content of the (C) terpene tackifying resin (content of the (C) terpene tackifying resin / the content of the (B) softener) to the content of the softener is 0.05 or more and 0.70 or less.

Description

Adhesive composition, adhesive sheet, laminate, image display device and input / output device {ADHESIVE COMPOSITION, ADHESIVE SHEET, STACKED BODY, IMAGE DISPLAY DEVICE, AND INPUT / OUTPUT DEVICE}

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

Recently, development to impart various functions to the pressure-sensitive adhesive composition has been actively conducted (for example, Patent Publication 1).

Japanese Patent Application Publication No. 2011-63639

The present inventors have found that even when the pressure-sensitive adhesive sheet formed using the pressure-sensitive adhesive composition having a specific component is stored for a long time, time-lapse deterioration of the pressure-sensitive adhesive sheet (decreased adhesive strength, etc.) is less likely to occur. The low-polar pressure-sensitive adhesive composition has been completed. The present invention provides a pressure-sensitive adhesive composition capable of maintaining a long-term adhesion, high transparency, low dielectric constant, excellent adhesion, weatherability, flexibility, flexibility, tack, step followability, and heat-resistant whitening adhesive layer, and An adhesive sheet, a laminate, an image display device and an input / output device obtained using the composition are provided.

1.A pressure-sensitive adhesive composition according to an aspect of the present invention,

(A) at least one block copolymer selected from X-Y-X type hydrogenated styrenic block copolymers and X-Y type hydrogenated styrenic block copolymers,

(B) a softener that is liquid at room temperature (23 ° C.),

(C) terpene tackifying resin,

(D) contains an aromatic tackifying resin,

With respect to 100 parts by mass of the (A) block copolymer, the (B) emollient contains 10 parts by mass or more and 300 parts by mass or less, and the (C) terpene tackifying resin is 1 part by mass or more and 30 parts by mass or less. Is contained, and the (D) aromatic tackifying resin is contained in an amount of 1 part by mass or more and 50 parts by mass or less, and

The content of the (C) terpene tackifying resin (the content of the (C) terpene tackifying resin / the content of the (B) softener) relative to the content of the (B) softener is 0.05 or more and 0.70 or less.

2. In the pressure-sensitive adhesive composition according to the above 1, the block copolymer (A) may be a mixture of an X-Y-X type hydrogenated styrenic block copolymer and an X-Y type hydrogenated styrenic block copolymer.

3. In the pressure-sensitive adhesive composition described in 1 or 2, the styrene content of the block copolymer (A) may be 10% by mass or more and 35% by mass or less.

4. In the pressure-sensitive adhesive composition according to any one of 1 to 3, the relative dielectric constant of the pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition may be 1 to 3.5.

5. In the pressure-sensitive adhesive composition according to any one of 1 to 4 above, the water vapor transmission rate of the pressure-sensitive adhesive layer having a film thickness of 50 μm obtained from the pressure-sensitive adhesive composition is 100 g / m 2 · in JIS Z 0208, 40 ° C. × 90% RH. It can be less than a day.

6. In the pressure-sensitive adhesive composition according to any one of 1 to 5, it can be used for bonding members constituting a touch panel type input / output device.

7. In the pressure-sensitive adhesive composition according to any one of 1 to 5 above, it can be used for bonding members constituting the organic EL display.

8. The laminate according to one aspect of the present invention includes an adhesive layer formed from the adhesive composition according to any one of 1 to 5 above, and a barrier film.

9. The pressure-sensitive adhesive sheet according to one aspect of the present invention can be obtained by drying a film formed from the pressure-sensitive adhesive composition according to any one of 1 to 5 above.

10. The image display device according to one aspect of the present invention includes the pressure-sensitive adhesive layer formed using the pressure-sensitive adhesive composition according to any one of 1 to 5 above.

11. The input / output device related to one aspect of the present invention includes the pressure-sensitive adhesive layer formed using the pressure-sensitive adhesive composition according to any one of 1 to 5 above.

According to the pressure-sensitive adhesive composition according to any one of the above 1 to 5, the (A) block copolymer, the (B) softener, the (C) terpene tackifying resin, and (D) aromatic tackifying resin is prescribed It can provide the adhesive composition which is contained in the ratio of (mixed), and is excellent in adhesive performance, and does not generate | occur | produce over time with an adhesive sheet easily.

Moreover, the said adhesive composition contains the said (A) block copolymer, the said (B) softener, the said (C) terpene tackifying resin, and the said (D) aromatic tackifying resin at the said ratio, and is low polarity. Moreover, since it is hydrophobic, it has the characteristics that the obtained adhesive layer has a low relative dielectric constant and excellent water vapor barrier properties.

In this way, the pressure-sensitive adhesive layer (adhesive sheet) obtained using the pressure-sensitive adhesive composition is, for example, a combination of members constituting the touch panel type input / output device and uses in which water vapor barrier properties are required (for example, an organic EL display, etc.) Can be used for applications that are susceptible to water, such as image display devices and input / output devices.

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

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.
2 is a cross-sectional view schematically showing a water vapor barrier laminate comprising an adhesive layer formed from the adhesive composition according to one embodiment of the present invention.
3 is a cross-sectional view schematically showing a water vapor barrier laminate comprising an adhesive layer formed from the adhesive composition according to one embodiment of the present invention.
4 is a cross-sectional view schematically showing a water vapor barrier laminate comprising an adhesive layer formed from the adhesive composition according to one embodiment of the present invention.

1. Adhesive composition

The pressure-sensitive adhesive composition according to one embodiment of the present invention, (A) XYX type hydrogenated (hydrogenated: hydrogenated) styrenic block copolymer and XY type hydrogenated styrenic block copolymer selected from at least one block copolymer (hereinafter referred to as , It may be simply referred to as "(A) component"), (B) Softener that is liquid at room temperature (23 ° C) (hereinafter, simply referred to as "(B) component"), and (C ) Terpene tackifying resin (hereinafter, sometimes referred to simply as "(C) component"), and (D) aromatic tackifying resin (hereinafter sometimes simply referred to as "(D) component") It contains.

In the pressure-sensitive adhesive composition according to the present embodiment, the component (B) contains 10 parts by mass or more and 300 parts by mass or less, and (C) component contains 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the component (A). It contains, and (D) component contains 1 mass part or more and 50 mass parts or less.

Moreover, in the adhesive composition which concerns on this embodiment, content of (C) component (content of (C) component / content of (B) component) with respect to content of (B) component is 0.05 or more and 0.70 or less.

The present inventors found that (C) component contained in the adhesive composition which concerns on this embodiment can suppress the deterioration over time of an adhesive sheet. More specifically, the present inventors, as a result of the (C) component preventing the component (B) from moving to the surface of the pressure-sensitive adhesive layer (adhesive sheet) in the pressure-sensitive adhesive composition according to the present embodiment, the pressure-sensitive adhesive layer (adhesive It was found that the time-dependent deterioration of the sheet) can be suppressed.

Among them, when the component (B) has a low molecular weight (for example, a weight average molecular weight of 5,000 or less), it is a low molecular weight and easily migrates to the surface of the pressure-sensitive adhesive layer (adhesive sheet). Red degradation is liable to occur. In this case, the time-lapse deterioration of the pressure-sensitive adhesive layer (adhesive sheet) can be effectively suppressed by adding the component (C) to the pressure-sensitive adhesive composition according to the present embodiment.

Although the mechanism by which (C) component suppresses the aging deterioration of the pressure-sensitive adhesive sheet obtained from the adhesive composition which concerns on this embodiment is not clear, compatibility of (C) component with (A) component and (B) component It is considered that the good thing and / or (C) component are arrange | positioned on the surface of the adhesive layer obtained from the adhesive composition which concerns on this embodiment, and it is thought that (B) component is prevented from moving to the surface of an adhesive layer. Thereby, it is estimated that even when the pressure-sensitive adhesive sheet is stored for a long period of time, it is possible to provide the pressure-sensitive adhesive sheet that does not deteriorate with time and does not deteriorate easily.

In addition, the inventors of the present application prevented the temporal deterioration of the adhesive strength and good step followability by setting the content of the component (C) / content of the component (B) to 0.05 to 0.70 in the pressure-sensitive adhesive composition according to the present embodiment. And it was found that compatibility of expression of adhesive force can be achieved.

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

1.1. (A) Ingredient

The component (A) is at least one block copolymer selected from X-Y-X type hydrogenated styrenic block copolymers and X-Y type hydrogenated styrenic block copolymers. Since the component (A) has low polarity and hydrophobicity, it can contribute to the low dielectric constant and water vapor barrier properties of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to the present embodiment.

(A) XYX type hydrogenated styrenic block copolymers and XY type hydrogenated styrenic block copolymers which are components are hard segments (X) derived from the polymer component of the aromatic vinyl monomer and soft derived from the polymer component of the conjugated diene monomer. It is a thermoplastic elastomer having a segment (Y). Here, more specifically, the aromatic vinyl compound is preferably styrene and α-methylstyrene (more preferably styrene), and the conjugated diene compound is preferably butadiene and isoprene.

As specific examples of the component (A), for example, styrene- (ethylene-propylene) -styrene block copolymer (SEPS) (hydrogenated product of styrene-isoprene-styrene block copolymer (SIS)), styrene- (Ethylene-butylene) -styrene block copolymer (SEBS) (hydrogenated product of styrene-butadiene-styrene block copolymer (SBS)), styrene- (butadiene-butylene) -styrene block copolymer (SBBS) XYX type triblock copolymers such as (partial hydrogenated product of styrene-butadiene-styrene type block copolymer (SBS)), styrene- (ethylene-propylene) type block copolymer (SEP) (styrene-isoprene type block copolymer ( XY-type diblock copolymers, such as hydrogenated products of SI) and styrene- (ethylene-butylene) type block copolymers (SEB) (hydrogenated products of styrene-butadiene type block copolymers (SB)). (A) As a component, these components may be used individually and may be used in mixture of 2 or more type.

In addition, (A) component is an XYX type triblock copolymer (hereinafter sometimes simply referred to as "triblock copolymer") and an XY type diblock copolymer (hereinafter simply referred to as "diblock copolymer") In some cases), the content of the triblock copolymer is preferably 20% by mass or more and 95% by mass or less, and more preferably 30% by mass or more and 90% by mass or less with respect to the mixture. Moreover, it is preferable that content of a diblock copolymer is 5 mass% or more and 80 mass% or less with respect to the mixture, and it is more preferable that it is 10 mass% or more and 70 mass% or less.

As the component (A), commercially available hydrogenated block copolymers, such as SEP type Septons 1001 and 1020, SEPS type Septon 2002, 2004, 2005, 2006, 2007, 2063 and 2104, SEBS type Septon 8004, 8006, 8007, 8076 and 8104 (all of the Septon series above are manufactured by Kuraresa), SEBS-type toughtecs H1221, H1662, H1052, H1053, H1041, H1051, H1517, H1043, H1272 and N504, SBBS-type toughtec P1500 , P2000 and JT83X (all of the above-mentioned Tufftech series manufactured by Asahi Chemical Co., Ltd.) may be used.

From the viewpoint of providing heat resistance to the pressure-sensitive adhesive composition according to the present embodiment, the content of the hard segment (X: for example, styrene) in the component (A) is preferably 10% by mass or more and 35% by mass or less, and 10% by mass It is more preferable that it is 20 mass% or more. When the content rate of the hard segment (X) in the component (A) is less than 10% by mass, the heat resistance is poor, whereas when it exceeds 35% by mass, the pressure-sensitive adhesive layer may become too hard and the adhesion with the adherend may be poor.

Moreover, from the viewpoint of excellent weather resistance, the hydrogenation rate (hydrogen addition rate) of the double bond contained in the polymer component of the conjugated diene monomer constituting the component (A) (hereinafter, simply referred to as “hydrogenation rate”) is preferably 90% or more. And more preferably 95% or more (although the hydrogenation rate is preferably 100%, it does not interfere even if trace amounts (for example, 0.001% or more and 0.1% or less) of the double bond remain). That is, in this invention, the hydrogenation rate of the double bond contained in the polymer component of a conjugated diene monomer means the ratio of the double bond contained in the polymer component of a conjugated diene monomer saturated by hydrogenation.

In view of being able to impart moderate flexibility, flexibility, and step followability to the pressure-sensitive adhesive layer, the weight average molecular weight of the component (A) in the pressure-sensitive adhesive composition according to the present embodiment is 10,000 or more and 300,000 or less (more preferably It is preferable that it is 50,000 or more and 300,000 or less). Moreover, when component (A) is a mixture of the above-mentioned triblock copolymer and diblock copolymer, the weight average molecular weight of the component (A) means the weight average molecular weight of the mixture.

1.2. (B) Ingredient

(B) A component is a softener which is liquid at normal temperature (23 degreeC). The component (B) has properties that are compatible with the soft segment (Y) constituting the component (A). (B) A component can contribute to the flexibility (wetting property) of the adhesive composition which concerns on this embodiment. In addition, due to the component (B), adhesion to the adherend and tack can be improved, and flexibility can be imparted to the pressure-sensitive adhesive layer obtained using the composition.

In addition, in the present invention, the term "liquid" includes a viscoelastic liquid that is viscous and other low-viscosity liquids.

Moreover, whether the component (B) is compatible with the soft segment (Y) of the component (A) is a polymer synthesized from only the component corresponding to the soft segment (Y) of the component (A), that is, only the conjugated diene monomer. And, it shall be evaluated using (B) component.

More specifically, in the mixture obtained by mixing the polymer polymerized only from the conjugated diene monomer and the component (B) using a solvent, if necessary, the occurrence of turbidity in the mixture obtained, or the phase and component (B) containing the polymer When the phase separation containing a phase is not visible to the naked eye, the component (B) is assumed to be compatible with the soft segment (Y) of the component (A), while the above-mentioned haze or phase separation is visible to the naked eye. It is assumed that the component (B) is not compatible with the soft segment (Y) of the component (A).

Since (B) component contained in the adhesive composition which concerns on this embodiment is used for the soft segment (Y) of the said (A) component, it adheres as a result by increasing the wettability of the adhesive layer. The adhesiveness and tack to the sieve can be improved, and flexibility can be imparted to the pressure-sensitive adhesive layer obtained using the composition.

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

(B) As a softener which can be used as a component, commercially available softeners, such as polybutene-based compounds, are Niseki polybutenes LV-7, LV-50, LV-100, HV-15, HV-35, HV-50 , HV-100, HV-300, HV-1900 and SV-7000 (all manufactured by JX Nikko Niseki Energy Co.), Tetrax 3T, 4T, 5T and 6T, Hymol 4H, 5H, 5.5 as polyisobutylene compounds H and 6H (both manufactured by JX Nikko Niseki Energy Co., Ltd.), and Kuraprene LIR-290 (manufactured by Kurare Co., Ltd.) may be used as the polyisoprene-based compound. As the component (B), these components may be used alone, or two or more of them may be used in combination.

(A) From the viewpoint of further improving the compatibility with the component, the content of the component (B) in the pressure-sensitive adhesive composition according to the present embodiment is preferably 10 parts by mass or more with respect to 100 parts by mass of the component (A) , More preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, while 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 the pressure-sensitive adhesive layer having better flexibility using the pressure-sensitive adhesive composition according to 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. Do.

1.3. (C) Ingredient

(C) The terpene tackifying resin which is a component is a tackifier resin derived from a terpene compound.

When (A) component and (B) component are mixed, (B) component tends to migrate to the surface of an adhesive layer. In the pressure-sensitive adhesive composition according to the present embodiment, by mixing the component (C), it is possible to prevent the component (B) from being transferred to the surface of the pressure-sensitive adhesive layer. Moreover, (C) component can also contribute to the improvement of the adhesive properties (adhesive force and tack) of the adhesive composition which concerns on this embodiment.

(C) The terpene tackifying resin which is a component has the property compatible with (A) component. More specifically, the component (C) can be used for both the hard segment (X) and the soft segment (Y) constituting the component (A).

Whether the component (C) is commonly used for both the hard segment (X) and the soft segment (Y) constituting the component (A) is a component corresponding to the hard segment (X) constituting the component (A), that is, , Evaluated using a polymer synthesized from only the aromatic vinyl monomer, a component corresponding to the soft segment (Y) constituting the component (A), that is, a polymer synthesized from only the conjugated diene monomer, and the component (C) It is assumed.

More specifically, (i) a mixture obtained by mixing a polymer synthesized from only the aromatic vinyl monomer corresponding to the hard segment (X) constituting the component (A) and the component (C) using a solvent if necessary, ( Ii) A mixture obtained by mixing a polymer synthesized from only the conjugated diene monomer corresponding to the soft segment (Y) constituting the component (A) with the component (C) using a solvent if necessary, (i) the component (A) In the mixture obtained by mixing the component (C) with a solvent, if necessary, when the occurrence of cloudiness or phase separation is not visible, the component (C) is assumed to be compatible with the component (A), On the other hand, when the turbidity or phase separation is visually seen in any of the above-mentioned mixtures (i) to (i), the component (C) is not to be compatible with the component (A).

Moreover, it is preferable that (C) component has the property compatible with (B) component.

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 (C) containing When the phase separation of the phase is not visible to the naked eye, the component (C) is assumed to be compatible with the component (B), while when the above-mentioned haze or phase separation is visible to the naked eye, the component (C) is the component (B) It is assumed that it is not commercially available.

As the component (C), for example, YS resin PX1250 (softening point 125 ± 5 ° C), YS resin PX1150 (softening point 115 ± 5 ° C), YS resin PX1000 (softening point 100 ± 5 ° C), YS resin PX1150N (softening point 115 ± 5 ℃), YS Polystar U130 (softening point 130 ± 5 ℃), YS Polystar U115 (softening point 115 ± 5 ℃), YS Polystar T160 (softening point 160 ± 5 ℃), YS Polystar T145 (softening point 145 ± 5 ℃), YS Polystar T130 (softening point 130 ± 5 ℃), YS Polystar T115 (softening point 115 ± 5 ℃), YS Polystar T100 (softening point 100 ± 5 ℃), YS Polystar S145 (softening point 145 ± 5 ℃) , YS Polystar G150 (softening point 150 ± 5 ℃), YS Polystar G125 (softening point 125 ± 5 ℃), YS Polystar N125 (softening point 125 ± 5 ℃), YS Polystar K140 (softening point 140 ± 5 ℃), 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 ℃, Clearlon P125 (softening point 125 ± 5 ℃), Clearon P115 (softening point 115 ± 5 ℃), Clearon P105 (softening point 105 ± 5 ℃), Clearon M125 (softening point 125 ± 5 ℃) , Clearon M115 (softening point 115 ± 5 ° C), Clearon M105 (softening point 105 ± 5 ° C), Clearon K100 (softening point 100 ± 5 ° C), Clearon K4100 (softening point 100 ± 5 ° C), YS resin TO125 (softening point) 125 ± 5 ℃), YS resin TO115 (softening point 115 ± 5 ℃), YS resin TO105 (softening point 105 ± 5 ℃), YS resin TR105 (softening point 105 ± 5 ℃) (all manufactured by Yasuhara Chemical Co., Ltd.) Can be used. As the component (C), these components may be used alone, or two or more of them may be used in combination.

It is preferable that the content of the component (C) in the pressure-sensitive adhesive composition according to the present embodiment is 1 part by mass or more with respect to 100 parts by mass of the component (A) from the viewpoint of further increasing compatibility with the component (A). , More preferably 3 parts by mass or more, more preferably 5 parts by mass or more, while preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less.

The content of (C) component relative to the content of (B) component ((C) component content / (B) from the point that the time-dependent deterioration of the adhesive force in the pressure-sensitive adhesive composition according to the present embodiment can be more effectively suppressed ) The content of the component) is preferably 0.05 or more, more preferably 0.07 or more, still more preferably 0.10 or more, while it is preferably 0.70 or less, more preferably 0.60 or less, and even more preferably 0.50 or less.

In the pressure-sensitive adhesive composition according to the present embodiment, from the viewpoint of further improving the compatibility between the component (A) and the component (B) and the component (C), the total content of the component (B) and the content of the component (C) (A) It is preferable that it is 11 or more with respect to 100 mass parts of content of (A) component, it is more preferable that it is 18 or more, it is more preferable that it is 25 or more, and it is preferable that it is 330 or less, it is more preferable that it is 275 or less, and it is 220 or less It is more preferable.

Moreover, in the adhesive composition which concerns on this embodiment, content of (B) component and content of (C) component from a viewpoint which can further improve the compatibility of (D) component and (B) component and (C) component The sum of (D) may be 0.5 or more and 10.0 or less with respect to the content of the component (D), preferably 0.7 or more, more preferably 0.8 or more, and more preferably 9.0 or less, and more preferably 8.0 or less.

From the point of being able to impart high adhesion, the softening point of the component (C) is preferably 100 ° C or higher, more preferably 120 ° C or higher, and even more preferably 145 ° C or higher (usually 300 ° C or lower).

It is preferable that the weight average molecular weight of (C) component is 200 or more and 5,000 or less from a point which can improve compatibility more.

1.4. (D) Ingredient

(D) The aromatic tackifying resin (component tackifying resin having an aromatic ring) which is a component has properties that are commonly used in the hard segment (X) constituting the component (A), and has a softening point of 80 ° C or higher. . (D) A component can contribute to the improvement of the cohesiveness and adhesive property (adhesion force) of the adhesive composition which concerns on this embodiment.

Moreover, whether or not the component (D) is compatible with the hard segment (X) constituting the component (A), only the component corresponding to the hard segment (X) constituting the component (A), that is, the aromatic vinyl monomer It will be evaluated using the polymer synthesized from and (D) component.

More specifically, in the mixture obtained by mixing the polymer polymerized only from the aromatic vinyl monomer and the component (D) using a solvent, if necessary, the occurrence of turbidity, or the phase and component (D) containing the polymer When the phase separation of the containing phase is not visible to the naked eye, the component (D) is assumed to be compatible with the hard segment (X) constituting the component (A), while the above-mentioned haze or phase separation is visible to the naked eye. In this case, it is assumed that the component (D) is not compatible with the hard segment (X) constituting the component (A).

Since (D) component contained in the adhesive composition which concerns on this embodiment is used for the hard segment (X) which comprises the said (A) component, it gives some hardness to the adhesive layer formed from the adhesive composition, , It is possible to increase the heat resistance and adhesive strength of the pressure-sensitive adhesive layer.

Examples of the component (D) that can be used are, for example, aromatic petroleum resins, styrene-based polymers, α-methylstyrene-based polymers, styrene- (α-methylstyrene) -based copolymers, styrene-aliphatic hydrocarbon-based copolymers, And styrene- (α-methylstyrene) -aliphatic hydrocarbon-based copolymers, styrene-aromatic hydrocarbon-based copolymers, and the like. More specifically, for example, FMR-0150 as a commercially available styrene-aromatic hydrocarbon-based copolymer (softening point 145 ° C, manufactured by Mitsui Chemicals), FTR-6100 as a styrene-aliphatic hydrocarbon-based copolymer (softening point 100 ° C, manufactured by Mitsui Chemicals) ), FTR-6110 (softening point 110 ° C, manufactured by Mitsui Chemicals) and FTR-6125 (softening point 125 ° C, manufactured by Mitsui Chemicals), FTR-7100 as a styrene- (α-methylstyrene) -aliphatic hydrocarbon-based copolymer (softening point 100 ° C) , Mitsui Chemicals Co., Ltd., 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 as α-methylstyrene polymer (softening point) 100 ° C, Mitsui Chemicals), FTR-2120 as a styrene- (α-methylstyrene) copolymer (softening point 120 ° C, manufactured by Mitsui Chemicals), FTR-2140 (softening point 145 ° C, manufactured by Mitsui Chemicals), Crystallex 3100 ( Softening point 100 ℃, Eastman Chemical Co., Ltd., Crystallex 3085 (Softening point 85 ℃, Eastman Chemical Co.), Crystallex 5140 (Softening point 140 ℃, Eastman Chemical Co.), Crystallex 1120 (Softening point 120 ℃, East Crystal Chemicals F85 (softening point 85 ° C, Eastman Chemicals), Crystallex F100 (softening point 100 ° C, Eastman Chemicals) and Crystallex F115 (softening point 115 ° C, Eastman Chemicals) Etc. can also be used. As the component (D), these components may be used alone, or two or more of them may be used in combination.

From the viewpoint of imparting durability to the pressure-sensitive adhesive composition according to the present embodiment and further increasing durability and adhesion, the softening point of the component (D) is preferably 80 ° C or higher, more preferably 100 ° C or higher, and more preferably 120 ° C or higher It is more preferable.

(D) It is preferable that a component is 5,000 or less in weight average molecular weight from a viewpoint of favorable compatibility and adhesiveness, and it is more preferable that it is 500 or more and 3,000 or less.

(A) From the viewpoint of improving the compatibility with the component, the content of the component (D) in the pressure-sensitive adhesive composition according to the present embodiment is preferably 1 part by mass or more with respect to 100 parts by mass of the component (A), It is more preferable that it is 5 parts by mass or more, more preferably 10 parts by mass or more, while it is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less.

Moreover, in the adhesive composition which concerns on this embodiment, it is preferable that the total content of (A) component, (B) component, (C) component, and (D) component is 70 mass% or more, and it is more preferable that it is 80 mass% or more. It is preferred (typically 100% by mass or less).

1.5. Form of the composition

The pressure-sensitive adhesive composition according to the present embodiment can be dissolved in a solvent and used. It is preferable that the said solvent is at least 1 sort (s) chosen from the aliphatic hydrocarbon and / or aromatic hydrocarbon which are liquid, for example at 23 degreeC.

Examples of the aliphatic hydrocarbon that can be used as a solvent include linear or branched aliphatic hydrocarbons such as n-pentane, methylpentane, n-hexane, isohexane, n-heptane, isoheptane, n-octane, isooctane, and the like. And cyclic aliphatic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclohexane.

Moreover, as an aromatic hydrocarbon which can be used as a solvent, toluene, benzene, o-xylene, m-xylene, p-xylene, ethylbenzene, mesitylene, chlorobenzene, nitrobenzene is mentioned, for example. As a solvent, 1 type or 2 types of aliphatic hydrocarbons and aromatic hydrocarbons can be used in combination. Moreover, the adhesive composition which concerns on this embodiment is a solvent other than an aliphatic hydrocarbon and an aromatic hydrocarbon as a solvent (For example, ester solvents, such as ethyl acetate, methyl acetate, butyl acetate, ketone solvents, such as methyl ethyl ketone and acetone. , An organic solvent commonly used in adhesives such as tetrahydrofuran and acetonitrile).

Moreover, it is preferable that content in the case of using a solvent is 1000 mass% or less, and more preferably 900 mass% or less with respect to 100 weight part of the whole adhesive composition which concerns on this embodiment.

1.6. Relative dielectric constant

The relative dielectric constant of the adhesive layer obtained from the adhesive composition according to the present embodiment is a value of the relative dielectric constant measured at a frequency of 100 Hz. The relative dielectric constant of the pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition for optics according to the present embodiment is 1 or more and 3.5 or less, preferably 1 or more and 3.2 or less, and more preferably 1 or more and 2.8 or less.

As described above, since the pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition for optics according to the present embodiment exhibits a low relative dielectric constant in a wide frequency band, in the image display device or input / output device on which the pressure-sensitive adhesive layer is formed, high-frequency pulses are generated. Malfunction can be prevented.

1.7. Water vapor barrier

The pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to the present embodiment has excellent water vapor barrier properties. More specifically, in the pressure-sensitive adhesive composition according to the present embodiment, the water vapor transmission rate of the pressure-sensitive adhesive layer having a film thickness of 50 μm obtained from the pressure-sensitive adhesive composition is 100 g / m 2 · day at JIS Z 0208, 40 ° C. × 90% RH. It may be less than, preferably less than 70 g / m 2 · day, more preferably less than 50 g / m 2 · day, less than 40 g / m 2 · day (typically, 1 × 10 ^-4 g / m 2 · day or more) It is more preferable.

In the present invention, the term "water vapor transmittance of the adhesive layer" means a measured value (g / m 2 · day) of water vapor transmittance at Z0208, 40 ° C × 90% RH of the pressure-sensitive adhesive monolayer adjusted to a film thickness of 50 µm.

1.8. Long-term persistence of adhesion

The pressure-sensitive adhesive layer (adhesive sheet) formed from the pressure-sensitive adhesive composition according to the present embodiment has a property that the time-lapse deterioration of the pressure-sensitive adhesive sheet hardly occurs even when stored for a long period of time. More specifically, the adhesive strength after the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to the present embodiment is placed in a dry environment at 60 ° C. for 1 month under 60 ° C., compared with the pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer before being placed under the environment. % Or more, and preferably 90% or more.

1.9. purpose

The use of the pressure-sensitive adhesive composition according to the present embodiment is not particularly limited as long as it is an application requiring adhesiveness, transparency, flexibility, flexibility, step followability, gas barrier properties such as water vapor, or moisture and heat whitening resistance. For example, it can be used for an adhesive sheet, an adhesive tape, a label, a pressure-sensitive sheet, a surface protective film / sheet, or optical applications.

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 elliptical polarizing film, an antireflection film, a brightness enhancing film, a light diffusing 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 may be used.

More specifically, the pressure-sensitive adhesive composition according to the present embodiment can be used for bonding members constituting an image display device (organic EL display) or an input / output device including a touch panel.

In recent years, malfunctions in operation of the touch panel have become a problem. Since the pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition according to the present embodiment has a low relative dielectric constant, when used for bonding members constituting the touch panel type input / output device, malfunction during operation of the touch panel can be prevented.

In addition, for example, since organic EL elements and organic thin film solar cells are susceptible to moisture, high water vapor barrier properties are required for the viscous and adhesive resin materials used in such organic EL devices and organic thin film solar cells. have. On the other hand, since the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to the present embodiment has water vapor barrier properties, it can be prevented from invading moisture by using it in applications that are susceptible to water, such as organic EL devices and organic thin film solar cells. Can be.

1.9.1. Touch panel applications

An example in which the pressure-sensitive adhesive layer (adhesive sheet) obtained from the pressure-sensitive adhesive composition according to the present embodiment is used for bonding members constituting the touch panel type input / output device will be described with reference to FIG. 1.

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 is a pressure-sensitive adhesive layer formed between a liquid crystal display (LCD) 10, a touch panel unit 20, and an LCD 10 and a touch panel unit 20. (30). The adhesive layer 30 bonds the LCD 10 and the touch panel unit 20.

The pressure-sensitive adhesive layer 30 is coated with, for example, the pressure-sensitive adhesive composition according to this embodiment on the surface of a separator (not shown), and the dried pressure-sensitive adhesive sheet is peeled from the separator, and the LCD 10 and the touch panel 20 ).

In addition, as shown in FIG. 1, the LCD 10 includes 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. They are stacked. 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.

In addition, as shown in FIG. 1, in the touch panel portion 20, the anti-scattering film 16, the pressure-sensitive adhesive layer 17, the ITO layer 18, and the glass panel 19 are laminated in this order. Consists of. The pressure-sensitive adhesive layer 17 bonds the anti-scattering film 16 and the ITO layer 18.

The pressure-sensitive adhesive layers 12, 14 and 17 are the same as the pressure-sensitive adhesive layer 30, and the pressure-sensitive adhesive sheet obtained by applying the pressure-sensitive adhesive composition according to this embodiment to the surface of a separator (not shown) and drying the volatile components from the separator. It may be provided by peeling.

1.9.2. Use in water vapor barrier laminates

The pressure-sensitive adhesive layer (adhesive sheet) obtained from the pressure-sensitive adhesive composition according to the present embodiment can be used for water vapor barrier laminate applications. That is, the layered product according to one embodiment of the present invention may include the pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition according to the present embodiment, and a barrier film.

2, 3, and 4 are cross-sectional views schematically showing an example of the adhesive water vapor barrier laminate according to the present embodiment.

The adhesive water vapor barrier laminate 110 shown in FIG. 2 includes a base 1 and an adhesive layer 2 formed on the base 1 (on the surface of the base 1). The material of the base material 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. 2, the case where the base material 1 is a single layer is shown.

Alternatively, the base material 1 may be an inorganic material (for example, a layer of at least one oxide, nitride, or oxynitride selected from 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 formed on the surface of the substrate 111. 3, the example which the base material 111 is comprised from several layers is shown. That is, as shown in FIG. 3, the substrate 111 includes a first layer 21 and another layer (second layer 22) formed on the surface of the first layer 21, and this second The pressure-sensitive adhesive layer 2 may be formed on the layer 22.

The material of the first layer 21 may be an inorganic material such as glass, or an organic material such as plastic exemplified above as the substrate 1. The material of the second layer 22 is not limited, and may be an inorganic barrier material such as metal or ceramics such as silicon oxide, silicon oxynitride, and silicon nitride, and organic materials such as plastics exemplified above as the base material 1 Materials may be used.

More specifically, the first layer 21 or the second layer 22 is an inorganic material (for example, at least one oxide, nitride, or selected from Si, Al, In, Sn, Zn, and Ti, or A layer of oxynitride (for example, a vapor-deposited film deposited on an organic film) may be used.

3, although the example in which the adhesive layer 2 was formed on the 2nd layer 22 of the base material 111 was shown, in the 1st layer 21 of the base material 111, the 2nd layer The pressure-sensitive adhesive layer 2 may be formed on the opposite side to the side on which the (22) is formed, or the pressure-sensitive adhesive layer 2 may be formed between the first layer 21 and the second layer 22.

4 shows an example in which the laminate 130 as an image display device includes the organic EL element 3. That is, the laminated body 130 shown in FIG. 4 is formed so as to cover the base 1 and the organic EL element 3 formed on the base 1 and the organic EL element 3 on the base 1 The adhesive layer 2 is included.

According to the layered body 130 shown in FIG. 4, the organic EL element 3 is sealed because the organic EL element 3 is sealed by forming the pressure-sensitive adhesive layer 2 so as to cover the organic EL element 3. ) Intrusion of water vapor into the furnace can be prevented.

According to the laminates 110, 120, and 130 of Figs. 2, 3, and 4, the cross-section of the pressure-sensitive adhesive layer 2 (from the horizontal side in Figs. 2, 3, and 4) It can prevent the invasion of water vapor. Moreover, in the laminated body (110, 120, 130), for example, in the state where another layer is not formed on the surface of the adhesive layer 2, such as during the manufacturing process of the laminated body, the adhesive layer ( 2) The intrusion of water vapor from the surface and the vertical direction (the vertical direction of the ground in FIGS. 2, 3 and 4) can also be blocked.

The pressure-sensitive adhesive layer 2 of FIGS. 2, 3, and 4 can be formed by directly applying the pressure-sensitive adhesive composition described below to the surface of the substrate 1 or the substrate 111, but the pressure-sensitive adhesive layer formed on the peelable film By transferring (2) to the surface of the substrate 1 or the substrate 111, the pressure-sensitive adhesive layer 2 can also be formed on the surface of the substrate 1 or the substrate 111. The water vapor transmission rate of the substrate 1 or the substrate 111 may be less than 30 g / m 2 · day in JIS Z 0208, 40 ° C. × 90% RH (cup method) (1976 version), and less than 10 g / m 2 · day. It is preferable, and it is more preferably less than 1 g / m 2 · day (typically, 1 × 10 ^-6 g / m 2 · day or more). For example, when the water vapor transmission rate of the substrates 1 and 111 is lower than that of the pressure-sensitive adhesive layer 2 (more specifically, when the substrates 1 and 111 have water vapor barrier properties (i.e., water vapor barrier) Sex film)), since the pressure-sensitive adhesive layer of the present invention can suppress the intrusion of water from the cross-section, the water vapor transmission rate of the laminates 110, 120, 130 is substantially, the water vapor of the substrates 1, 111 Transmittance can be.

The thickness of the base materials 1 and 111 is usually 1 µm or more and 500 µm or less, and preferably 5 µm or more and 200 µm or less.

In addition, when the adhesive vapor barrier laminate according to the present embodiment has transparency (for example, the total light transmittance of the adhesive vapor barrier laminate according to the present embodiment is 85% in JIS K 7361 method (1997 version). In the case of the above), the total light transmittance of the substrates 1 and 111 is preferably 85% or more (typically 100% or less) in the JIS K 7361 method, more preferably 87% or more.

1.10. Effect

First, the pressure-sensitive adhesive composition according to the present embodiment prevents migration of the component (B) to the surface of the pressure-sensitive adhesive layer due to the component (C), and elapses time when the pressure-sensitive adhesive sheet obtained from the pressure-sensitive adhesive composition is stored for a long time. Red deterioration is suppressed.

Second, the pressure-sensitive adhesive composition according to the present embodiment is low-polarity and hydrophobic, resulting in a low dielectric constant of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition and excellent water vapor barrier properties.

Third, the pressure-sensitive adhesive composition according to the present embodiment is excellent in step followability because the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition due to the component (B) has flexibility (wetting) and flexibility.

Fourth, since the adhesive composition according to the present embodiment contains components (C) and (D), tackiness is imparted, and the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition is excellent in adhesive strength and time-lapse stability of adhesive strength. .

Fifth, the pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition according to the present embodiment has durability due to (A) component and (C) component and (D) component.

In this way, the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to the present embodiment has a time-dependent deterioration of the adhesive force when the pressure-sensitive adhesive sheet obtained from the pressure-sensitive adhesive composition is stored for a long time, has a low relative dielectric constant, water vapor barrier property, It has excellent flexibility, flexibility, step followability, adhesion and durability. For this reason, it can be preferably used, for example, in a touch panel type input / output device or an organic EL display.

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

The pressure-sensitive adhesive layer (adhesive sheet) according to one embodiment of the present invention is obtained by drying the film formed from the pressure-sensitive adhesive composition according to the present embodiment. More specifically, the pressure-sensitive adhesive layer (adhesive sheet) according to one embodiment of the present invention includes: (A) 100 parts by mass, (B) 10 parts by mass or more and 300 parts by mass or less, and (C) 1 part by mass. Part 30 or more and 30 parts by mass or less, and (D) 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 pressure-sensitive adhesive layer according to the present embodiment can be obtained by dissolving and coating the pressure-sensitive adhesive composition according to the above-described embodiment in a solvent and drying and removing the solvent. That is, the manufacturing method of the pressure-sensitive adhesive layer (adhesive sheet) according to one embodiment of the present invention comprises the steps of coating the pressure-sensitive adhesive composition according to the above-described embodiment dissolved in a solvent on a substrate to obtain a film, and drying the film to remove the solvent. , The step of obtaining an adhesive layer.

For example, the pressure-sensitive adhesive layer (adhesive) according to the present embodiment is applied by applying the pressure-sensitive adhesive composition according to the present embodiment dissolved in a solvent to the surface of the release substrate (separator), and maintaining the separator at a temperature at which the solvent evaporates, for example. Sheet).

More specifically, the pressure-sensitive adhesive composition according to the present embodiment dissolved in a solvent on a release substrate is coated with a gravure coater, a Meyer bar coater, an air knife coater, a roll coater, or the like, and the applied pressure-sensitive adhesive composition is at room temperature (for example, 15 ° C or higher and 40 ° C or lower), or by appropriate heating (for example, 40 ° C or higher and 200 ° C or lower), drying, and the pressure-sensitive adhesive layer according to the present embodiment can be produced.

Alternatively, the pressure-sensitive adhesive layer according to the present embodiment may be produced by directly applying the pressure-sensitive adhesive composition according to the present embodiment to an adherend.

Since the adhesive layer which concerns on this embodiment is excellent in transparency, the total light transmittance may be 85% or more in JIS K 7361 method, and it is preferable that it is 90% or more.

Moreover, since the adhesive layer which concerns on this embodiment is excellent in durability and flexibility, the storage elastic modulus in 25 degreeC and 1 Mpa may be 1x10 ⁴ Mpa or more and 2x10 ⁶ Mpa or less, and 5x10 ⁴ It is preferable that it is ㎩ or more and 1 × 10 ⁶ ㎩ or less.

The film thickness of the pressure-sensitive adhesive layer according to the present embodiment is usually in the range of 10 μm or more and 500 μm or less, preferably 20 μm or more and 300 μm or less.

3. Examples

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

3.1. Preparation of adhesive composition

The components shown in Table 1 were mixed to prepare the pressure-sensitive adhesive compositions of Examples 1 to 12 and Comparative Examples 1 to 3, respectively.

That is, the (A) component and other components were dissolved together in a solvent (150 parts by mass of toluene) to prepare the pressure-sensitive adhesive compositions of Examples 1 to 12 and Comparative Examples 1 to 3, respectively.

In the pressure-sensitive adhesive compositions of Examples 1 to 12, solids were not visually observed in the pressure-sensitive adhesive composition, and it was confirmed that dullness and cloudiness were not visible in the pressure-sensitive adhesive composition, and clogging was not caused when filtered with a 1 μm mesh filter paper. It was confirmed that there was no residue on the filter paper. From this point, it was confirmed that (A) component, (B) component, (C) component, and (D) component were dissolved in the solvent in the adhesive composition of Examples 1-12 and Comparative Examples 1-3.

3.2. Preparation of adhesive sheet for evaluation

The pressure-sensitive adhesive composition solution obtained in Examples and Comparative Examples was coated on a release-treated polyethylene terephthalate film so that the film thickness after drying was 50 µm, and the organic solvent (toluene) was removed with a dryer at 90 ° C. Subsequently, the peeled-treated polyethylene terephthalate film was pasted to the coated surface of the pressure-sensitive adhesive layer to obtain a pressure-sensitive adhesive sheet for evaluation with a film thickness of 50 µm.

3.3. Assessment Methods

3.3.1. adhesiveness

(Early)

Above 3.2. The polyethylene terephthalate film on one side of the pressure-sensitive adhesive sheet for evaluation with a film thickness of 50 μm obtained by the method described in the column was peeled off, a polyethylene terephthalate film with a film thickness of 100 μm was bonded, cut to a width of 25 mm to prepare a test piece.

The peeled polyethylene terephthalate film of the test piece was peeled off, and the exposed adhesive coating surface was pressed onto glass using a 2 kg roller. After 20 minutes from sticking, 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 aging)

Above 3.2. The polyethylene terephthalate film on one side of the pressure-sensitive adhesive sheet for evaluation with a film thickness of 50 μm obtained by the method described in the column was peeled off, a polyethylene terephthalate film with a film thickness of 100 μm was bonded, cut to a width of 25 mm to prepare a test piece.

The obtained test piece was left in a dry environment at 60 ° C for 1 month, and then left for 1 hour in a 23 ° C x 50% RH environment, and then the peeled polyethylene terephthalate film of the test piece was peeled off, and the exposed pressure-sensitive adhesive coating surface was 2 kg. The roller was pressed into the glass. After 20 minutes from the affix, the adhesive sheet was peeled from the glass plate (23 ° C., peeling angle 180 °, peeling rate 300 mm / min), and the adhesive strength after aging was measured.

3.3.2. Step followability

Above 3.2. The pressure-sensitive adhesive sheet for evaluation having a film thickness of 50 µm obtained by the method described in the column was transferred to a polyethylene terephthalate film having a film thickness of 100 µm, cut to 50 mm × 50 mm to obtain an evaluation test piece.

Then, a polyethylene terephthalate film having a film thickness of 25 µm cut to 15 mm × 15 mm was placed on a glass plate, and the test piece was covered so that the pressure-sensitive adhesive layer was covered on the entire surface of the polyethylene terephthalate film (15 mm × 15 mm) on the glass plate. 50 mm × 50 mm) was adhered and subjected to autoclave treatment (50 ° C., 5 atm, 20 minutes), then allowed to stand at room temperature for 1 hour, and the appearance of the step portion was visually observed.

Based on the above, the step followingability of the pressure-sensitive adhesive layer obtained by the pressure-sensitive adhesive composition was evaluated by the following evaluation criteria.

(evaluation)

○: Visually, no voids or bubbles were observed in the patch step.

(Triangle | delta): Visually, some voids and air bubbles were confirmed in the patch | step difference part.

X: Clear voids and air bubbles were observed in the patch step portion.

3.3.3. Initial tack (probe tack)

Above 3.2. The polyethylene terephthalate film on one side of the pressure-sensitive adhesive sheet for evaluation with a film thickness of 50 μm obtained by the method described in the column was peeled off, and a polyethylene terephthalate film with a film thickness of 100 μm was bonded to prepare a test piece. The peeled polyethylene terephthalate film of the test piece was peeled off, and the probe tack of the exposed adhesive coating surface was measured. The probe had a SUS of 5 mm in diameter, a contact time of 1 second, a probe speed of 1 cm / sec, and a load of 20 g.

3.3.4. Water vapor transmission rate

The water vapor transmission rate was evaluated in accordance with JIS Z 0208. That is, the above 3.2. After peeling the polyethylene terephthalate film on both sides of the pressure-sensitive adhesive sheet for evaluation with a film thickness of 50 µm obtained by the method described in the column, and attaching the nonwoven fabric, put it between the nonwoven fabric on a moisture permeable cup (diameter 60 mm) containing about 10 g of calcium chloride. The adhesive sheet for evaluation was covered and sealed around. Thereafter, the moisture-permeable cup was still stopped under a 40 ° C x 90% RH environment to measure.

3.3.5. Storage modulus

Above 3.2. The pressure-sensitive adhesive sheets for evaluation of the film thickness of 50 µm obtained by the method described in the column were affixed multiple times under an environment of 23 ° C × 50% RH, treated with an autoclave of 50 ° C x 5 atm for 20 minutes, and a pressure-sensitive adhesive layer having a thickness of 1.0 mm. Was produced. For the pressure-sensitive adhesive layer having a thickness of 1.0 mm, a dynamic viscoelasticity measurement method in accordance with JIS K 7244 (temperature range -40 ° C to 160 ° C, heating rate of 3.67 ° C / min, frequency 1 using Anton Physar's "Physica MCR300") Viscoelastic spectrum was measured according to the condition of ㎐), and the storage modulus at a temperature of 25 ° C was determined.

3.3.6. Relative dielectric constant

To a copper foil having a film thickness of 100 µm, the above 3.2. The adhesive sheet for evaluation of the film thickness of 50 micrometers obtained by the method described in the column was affixed, and was also attached to a copper foil having a film thickness of 100 micrometers to obtain a measurement sample. The LCR meter 6440B manufactured by Toyo Technica was used to connect to the copper foil, and the relative dielectric constant was calculated under the conditions of a frequency of 100 kHz and 23 ° C × 65% RH.

3.3.7. Total light transmittance

Above 3.2. The polyethylene terephthalate film on one side of the pressure-sensitive adhesive sheet for evaluation having a film thickness of 50 µm obtained by the method described in the column was peeled off and pasted onto glass to prepare a test piece. After autoclaving the test piece (50 ° C, 5 atm, 20 minutes), the other polyethylene terephthalate film was removed, and the total light transmittance of the pressure-sensitive adhesive layer was measured using a haze meter (model name `` HM-150 '', manufactured by Murakami Color Technology Research Institute). ).

In addition, each component used in the Example and the comparative example is as follows.

・ (A) Ingredient

Polymer 1: A mixture of SEP (50 mass%) and SEPS (50 mass%) (styrene content 15 mass%, weight average molecular weight 150,000)

Polymer 2: A mixture of SEP (50 mass%) and SEPS (50 mass%) (styrene content 20 mass%, weight average molecular weight 170,000)

Polymer 3: A mixture of SEP (60 mass%) and SEPS (40 mass%) (styrene content 15 mass%, weight average molecular weight 130,000)

Polymer 4: Mixture of SEP (30 mass%) and SEPS (70 mass%) (styrene content 15 mass%, weight average molecular weight 200,000)

Polymer 5: A mixture of SEP (60 mass%) and SEPS (40 mass%) (styrene content 35 mass%, weight average molecular weight 130,000)

Moreover, the hydrogenation rate of SEP and SEPS used by polymers 1-5 was 90% or more.

・ (B) Ingredient

LV-100: Polybutene (Mn = 500) (manufactured by JX Nikko Niseki Energy Co., Ltd.)

HV-300: Polybutene (Mn = 1,400) (manufactured by JX Nikko Niseki Energy Co., Ltd.)

・ (C) Ingredient

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

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

・ (D) Ingredient

FMR-0150: aromatic tackifying resin having a softening point of 145 ° C (Mitsui Chemical Co., Ltd., weight average molecular weight: 2,040)

FTR-6100: aromatic tackifying resin having a softening point of 100 ° C (Mitsui Chemical Co., Ltd., weight average molecular weight: 1,210)

·solvent

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

3.4. Evaluation results

From the results of Table 1, the pressure-sensitive adhesive composition of Examples 1 to 12 of the present application contains (A) component, (B) component, (C) component, and (D) component, and also (B) C) When the content of the component (the content of the component (C) / the content of the component (B)) is 0.05 or more and 0.70 or less, the adhesive strength is maintained for a long time, has high transparency, has a low dielectric constant, and also provides adhesion, weather resistance, flexibility, It is possible to obtain an adhesive layer excellent in flexibility, tack, step followability, and moisture resistance whitening.

On the other hand, as shown in Table 1, since the composition of Comparative Example 1 of the present application does not contain the component (B), it can be understood that the step followability is poor. In addition, the pressure-sensitive adhesive sheet obtained using the pressure-sensitive adhesive layer obtained from the composition of Comparative Example 1 herein had a low tack, and a pressure-sensitive adhesive sheet having a film thickness of 50 μm could not be laminated to adhere to a thickness of 1 mm. Moreover, since the composition of the comparative example 2 of this application does not contain the component (C), it can be understood that the adhesive force deteriorated with time. Moreover, since the composition of the comparative example 3 of this application does not contain the component (D), it can be understood that the adhesive force is inferior.

Moreover, the total light transmittance of the said adhesive layer formed from the adhesive composition of Examples 1-12 measured by the said evaluation method was all 92%. In this respect, it is understood that the pressure-sensitive adhesive layers formed from the pressure-sensitive adhesive compositions of Examples 1 to 12 are excellent in transparency.

Claims (11)

(A) Styrene- (ethylene-propylene) -styrene block copolymer (SEPS), hydrogenated product of styrene-isoprene-styrene block copolymer (SIS), styrene- (ethylene-butylene) -styrene block copolymer (SEBS), hydrogenated product of styrene-butadiene-styrene block copolymer (SBS), styrene- (butadiene-butylene) -styrene block copolymer (SBBS), styrene-butadiene-styrene block copolymer (SBS) Hydrogenated part of styrene- (ethylene-propylene) type block copolymers (SEP), styrene-isoprene type block copolymers (SI), styrene- (ethylene-butylene) type block copolymers (SEB) and At least one or more block copolymers selected from hydrogenated products of styrene-butadiene type block copolymers (SB),
(B) a softener that is liquid at room temperature (23 ° C.),
(C) terpene tackifying resin,
(D) The softening point is 120 ° C or higher, aromatic petroleum resin, styrene polymer, α-methylstyrene polymer, styrene- (α-methylstyrene) copolymer, styrene-aliphatic hydrocarbon copolymer, styrene- (α- Methyl styrene) -containing at least one aromatic tackifying resin selected from aliphatic hydrocarbon-based copolymers and styrene-aromatic hydrocarbon-based copolymers,
With respect to 100 parts by mass of the (A) block copolymer, the (B) softener contains 10 parts by mass or more and 300 parts by mass or less, and the (C) terpene tackifying resin is 1 part by mass or more and 30 parts by mass or less. Is contained, and the (D) aromatic tackifying resin is contained in an amount of 1 part by mass to 50 parts by mass, and
The adhesive composition in which the content of the (C) terpene tackifying resin (the content of the (C) terpene tackifying resin / the content of the (B) softener) with respect to the content of the (B) softener is 0.05 or more and 0.70 or less. According to claim 1,
The (A) block copolymer is a styrene- (ethylene-propylene) -styrene block copolymer (SEPS), a hydrogenated product of a styrene-isoprene-styrene block copolymer (SIS), styrene- (ethylene-butylene) -Styrene-type block copolymers (SEBS), hydrogenated additives of styrene-butadiene-styrene type block copolymers (SBS), styrene- (butadiene-butylene) -styrene block copolymers (SBBS) and styrene-butadiene-styrene type At least one member selected from partial hydrogenation of block copolymers (SBS), and styrene- (ethylene-propylene) type block copolymers (SEP), hydrogenated products of styrene-isoprene type block copolymers (SI), styrene- ( The adhesive composition which is a mixture of at least 1 sort (s) chosen from hydrogenation of ethylene-butylene) type block copolymer (SEB) and styrene-butadiene type block copolymer (SB). The method of claim 1 or 2,
The adhesive composition whose styrene content rate of the said (A) block copolymer is 10 mass% or more and 35 mass% or less. The method of claim 1 or 2,
The pressure-sensitive adhesive composition having a relative dielectric constant of 1 or more and 3.5 or less of the pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition. The method of claim 1 or 2,
The pressure-sensitive adhesive composition of the pressure-sensitive adhesive layer having a film thickness of 50 μm obtained from the pressure-sensitive adhesive composition is less than 100 g / m 2 · day at JIS Z 0208, 40 ° C. × 90% RH. The method of claim 1 or 2,
An adhesive composition used for bonding members constituting a touch panel type input / output device. The method of claim 1 or 2,
An adhesive composition used for bonding members constituting an organic EL display. A laminate comprising the pressure-sensitive adhesive layer obtained from the pressure-sensitive adhesive composition according to claim 1 or 2, and a barrier film. An adhesive sheet obtained by drying a film formed from the adhesive composition according to claim 1 or 2. An image display device comprising an adhesive layer formed using the adhesive composition according to claim 1 or 2. An input / output device comprising an adhesive layer formed using the adhesive composition according to claim 1 or 2.

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