JP6962009B2 - Adhesive composition and laminate using it - Google Patents

Description

The present invention relates to a pressure-sensitive adhesive composition in which the cured product has excellent adhesion and flexibility, and has high durability, and further relates to a laminate using the pressure-sensitive adhesive composition.

Adhesives are used for various purposes such as tapes and labels. In the field of electro-optical devices, adhesives with high adhesion and high transparency are used to attach panels and optical members such as optical filters, sensors, and front plates. It is used for matching. In recent years, in-vehicle electro-optical devices such as car navigation systems are required to have remarkably high thermal shock resistance for adhesives as compared with indoor electro-optical devices such as televisions. This is because in-vehicle devices are exposed to a considerably high temperature in a vehicle for a long time during the day, and on the contrary, they are in a considerably low temperature state at night. For this reason, when the adhesive generally used for the polarizing plate and the front plate of an indoor television is used for an in-vehicle device, it cannot be said that the heat-resistant impact resistance against a severe temperature change is always sufficient, and peeling may occur. there were.

Further, in in-vehicle devices, a transparent resin plate is often used in order to reduce the weight of the front plate and improve the design. However, when the resin plate is placed under high temperature and high humidity, out gas is released from the inside of the resin plate, and the gas forms bubbles at the interface between the resin plate and the pressure-sensitive adhesive and in the pressure-sensitive adhesive composition, which reduces visibility. There is also the problem of moisture resistance and heat resistance.

Conventionally, as a method for improving the moist heat resistance of a pressure-sensitive adhesive, a method of increasing the Tg of the pressure-sensitive adhesive by using urethane acrylate showing a high glass transition temperature (Tg) is known (see Patent Document 1). However, when the Tg of the pressure-sensitive adhesive is increased, the pressure-sensitive adhesive becomes hard and the flexibility deteriorates, and the pressure-sensitive adhesive follows the difference in thermal expansion of the bonded resin plates in the heat-resistant impact test assuming a temperature change inside the vehicle. There was a problem that peeling and the like occurred without being able to do so. In addition, the improvement of moisture and heat resistance was not always sufficient.

Japanese Unexamined Patent Publication No. 2013-35920

The present invention has been achieved in view of the above circumstances, and an object thereof is a pressure-sensitive adhesive composition in which the cured product has high adhesion, heat impact resistance, and moisture heat resistance, and a pressure-sensitive adhesive composition. It is to provide a laminated body having a layer.

（式中のａは１〜１５の整数である。Ｒ^１は炭素数１〜１４の炭化水素基であり、Ｒ^２は炭素数１〜１４の炭化水素基、下記式２で表されるポリエーテル基、又は下記式３で表されるポリエステル基であり、Ｒ^３は水素原子又はメチル基であり、Ｒ^４は炭素数１〜１４の炭化水素基である。）

（式中のｂは１〜２０の整数である。Ｒ^５はそれぞれ独立した炭素数２〜１４の炭化水素基）

（式中のｃは１〜２０の整数である。Ｒ^６及びＲ^７は炭素数１〜１４の炭化水素基であり、それぞれ同一であっても異なっていても良い。） The pressure-sensitive adhesive composition of the present invention comprises (A) a polyfunctional thiol compound having 2 to 6 thiol groups, (B) a polyfunctional (meth) acrylate having 2 to 6 (meth) acrylic groups, and (C). ) Contains urethane (meth) acrylate represented by the following formula 1 and having a weight average molecular weight of 1000 to 15000, monofunctional (meth) acrylate having only one (D) (meth) acrylic group, and (E) hydroxyl group. When the polyfunctional thiol compound containing (meth) acrylamide and having (A) 2 to 6 thiol groups is 100 parts by mass, (B) polyfunctional (meth) acrylate is 5 to 25 parts by mass, (C). ) 150 to 200 parts by mass of urethane (meth) acrylate, 30 to 150 parts by mass of monofunctional (meth) acrylate having only one (D) (meth) acrylic group, (E) hydroxyl group-containing (meth) acrylamide. It is contained in a proportion of 5 to 15 parts by mass.

(A in the formula is an integer of ¹ to 15. R 1 is a hydrocarbon group ^{having 1 to 14 carbon atoms, R 2} is a hydrocarbon group having 1 to 14 carbon atoms, and the poly represented by the following formula 2. It is an ether group or a polyester group represented by the following formula 3, R ³ is a hydrogen atom or a methyl group, and R ⁴ is a hydrocarbon group having 1 to 14 carbon atoms.

(B in the formula is an integer of 1 to 20. R ⁵ is an independent hydrocarbon group having 2 to 14 carbon atoms)

(C in the formula is an integer of 1 to 20. R ⁶ and R ⁷ are hydrocarbon groups having 1 to 14 carbon atoms, which may be the same or different from each other.)

（式中のｄは２又は３であり、ｅは０又は１であり、ｆは１又は２であり、ｄとｅとｆの和は４である。Ｒ^８は、メチレン基、エチレン基又はイソプロピレン基であり、Ｒ^９は、下記式５又は式６で表される２価の官能基であり、Ｒ^１０は、メチル基又はエチル基であり、Ｒ^１１は、炭素数が１〜１２の炭化水素基である。）

（式中のＲ^１２は水素原子又はメチル基である。）

（式中のＲ^１３は水素原子又はメチル基である。） The polyfunctional thiol compound having 2 to 6 thiol groups (A) is preferably a polyfunctional thiol compound represented by the following formula 4.

(D in the formula is 2 or 3, e is 0 or 1, f is 1 or 2, and the sum of d, e and f is 4. R ⁸ is a methylene group, an ethylene group or It is an ^{isopropylene group, R 9} is a divalent functional group represented by the following formula 5 or formula 6, R ¹⁰ is a methyl group or an ethyl group, and R ¹¹ has 1 to 12 carbon atoms. It is a hydrocarbon group of.)

^{(R 12} in the formula is a hydrogen atom or a methyl group.)

^{(R 13} in the formula is a hydrogen atom or a methyl group.)

（式中のｇは２〜５の整数であり、ｈは０〜２の整数であり、ｉは１〜４の整数であり、ｇとｈとｉの和は６である。Ｒ^１４は下記式８で表される６価の官能基であり、Ｒ^１５は、メチレン基、エチレン基又はイソプロピレン基であり、Ｒ^１６は、下記式５又は式６で表される２価の官能基であり、Ｒ^１７は、メチル基又はエチル基であり、Ｒ^１８は、炭素数が１〜１２の炭化水素基である。）

（式中のＲ^１２は水素原子又はメチル基である。）

（式中のＲ^１３は水素原子又はメチル基である。）

The polyfunctional thiol compound having 2 to 6 thiol groups (A) is preferably a polyfunctional thiol compound represented by the following formula 7.

(G in the formula is an integer of 2 to 5, h is an integer of 0 to 2, i is an integer of 1 to 4, and the sum of g, h, and i is 6. R ¹⁴ is as follows. It is a hexavalent functional group represented by the formula 8, R ¹⁵ is a methylene group, an ethylene group or an isopropylene group, and R ¹⁶ is a divalent functional group represented by the following formula 5 or formula 6. Yes, R ¹⁷ is a methyl group or an ethyl group, and R ¹⁸ is a hydrocarbon group having 1 to 12 carbon atoms.)

^{(R 12} in the formula is a hydrogen atom or a methyl group.)

^{(R 13} in the formula is a hydrogen atom or a methyl group.)

（式中のＲ^１９は下記式１０で表される３価の官能基であり、Ｒ^２０は下記式５又は式６で表される２価の官能基であり、Ｒ^２１は炭素数が１〜１２の炭化水素基である。）

（式中のＲ^２２はメチレン基、エチレン基又はイソプロピレン基である。）

（式中のＲ^１２は水素原子又はメチル基である。）

（式中のＲ^１３は水素原子又はメチル基である。） The polyfunctional thiol compound having 2 to 6 thiol groups (A) is preferably a polyfunctional thiol compound represented by the following formula 9.

(R ¹⁹ in the formula is a trivalent functional group represented by the following formula 10, R ²⁰ is a divalent functional group represented by the following formula 5 or formula 6, and R ²¹ has 1 carbon number. ~ 12 hydrocarbon groups.)

^{(R 22} in the formula is a methylene group, an ethylene group or an isopropylene group.)

^{(R 12} in the formula is a hydrogen atom or a methyl group.)

^{(R 13} in the formula is a hydrogen atom or a methyl group.)

In the laminate of the present invention, an uncured pressure-sensitive adhesive layer made of the above-mentioned pressure-sensitive adhesive composition is laminated on one surface of a transparent base material.

In the laminate of the present invention, an uncured pressure-sensitive adhesive layer made of the above-mentioned pressure-sensitive adhesive composition and a base material are laminated in this order on one surface of a transparent base material.

In the laminate of the present invention, the pressure-sensitive adhesive layer on which the pressure-sensitive adhesive composition is cured and the base material are laminated in this order on one surface of the transparent base material.

In the present invention, "(meth) acrylate" means a general term including both acrylate and methacrylate, and the same applies to "(meth) acrylamide", "(meth) acrylic group" and the like. Further, in the present invention, "○○ to XX" indicating a numerical range is a concept including a lower limit value (○○) and an upper limit value (XX) unless otherwise specified. That is, to be exact, it means "more than XX and less than XX". Further, "molecular weight" means a weight average molecular weight unless otherwise specified.

The present invention can provide a pressure-sensitive adhesive composition in which the cured product has high adhesion, heat impact resistance, and moisture heat resistance, and a laminate having a pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition of the present invention improves the moisture barrier property by forming a precise crosslinked network by the addition reaction of polyfunctional thiol, polyfunctional (meth) acrylate, and urethane (meth) acrylate. Therefore, even if the cured product is exposed to a high humidity atmosphere, the infiltration of water can be suppressed. In addition, the thioether bond generated by the thiol-ene reaction can change the bond angle and bond length more flexibly than the bond with atoms such as C, O, and N, so that the cured product has excellent flexibility (heat impact resistance). Shows excellent adhesion to the substrate.

Furthermore, by adding a hydroxyl group-containing (meth) acrylamide, a hydrogen-bondable hydroxyl group or acrylamide group is introduced on the cross-linked network, and the cross-linking density can be efficiently increased through the hydrogen bond in the cross-linked network. .. Further, since cross-linking by hydrogen bonds does not reduce the flexibility of the cured product as compared with covalent bonds, it is possible to improve the moisture barrier property and toughness while maintaining high thermal shock resistance.

In addition, since water tends to collect near hydroxyl groups under high temperature and high humidity, even if water infiltrates under high temperature and high humidity, the infiltrated water is captured by hydrogen bonds of hydroxyl group-containing (meth) acrylamide. Since the acrylamide group is less likely to be hydrolyzed than the (meth) acrylic group, the composition is less likely to deteriorate even under high temperature and high humidity. As a result, the composition is less likely to deteriorate even when placed under stricter high temperature and high humidity, and the heat resistance to moisture can be improved.

In other words, since a precise cross-linking network is formed by the addition reaction of polyfunctional thiol and polyfunctional (meth) acrylate, the cross-linking density can be efficiently increased even with a small amount of hydroxyl group-containing (meth) acrylamide, and flexibility. It is possible to exhibit significantly excellent durability (moisture and heat resistance) without losing.

As a result, the pressure-sensitive adhesive composition of the present invention can have excellent adhesion and flexibility (heat and impact resistance) in a cured product, and can realize high durability (moisture and heat resistance).

Hereinafter, the present invention will be described in detail. The pressure-sensitive adhesive composition of the present invention comprises (A) a polyfunctional thiol compound having 2 to 6 thiol groups, (B) polyfunctional (meth) acrylate, (C) urethane (meth) acrylate, and (D) (meth). The essential components are monofunctional (meth) acrylate having only one acrylic group and (E) hydroxyl group-containing (meth) acrylamide.

<(A) Polyfunctional thiol compound having 2 to 6 thiol groups>
The polyfunctional thiol compound having 2 to 6 thiol groups (A) may be a compound having 2 to 6 thiol groups at the terminal, and is represented by the above formula 4, formula 7, or formula 9. A thioether-containing (meth) acrylate derivative is preferred. Only one type of polyfunctional thiol compound may be used alone, or two or more types may be used in combination.

When the pressure-sensitive adhesive composition contains (A) a polyfunctional thiol compound having 2 to 6 thiol groups, the curing shrinkage can be reduced and the adhesion of the cured product can be improved. Further, when the number of thiol groups is 5 or less, the adhesion of the cured product becomes higher, which is preferable. On the other hand, a polyfunctional thiol having 7 or more thiol groups is not preferable because the crosslink density is high and the curing shrinkage is large, so that the adhesion of the cured product is lowered. Further, in the thioether-containing (meth) acrylate derivative represented by the above formula 4, formula 7, or formula 9, a part of the thiol group is modified and an alkyl chain is introduced at the terminal. Therefore, the alkyl chain becomes a spacer and the distance between the cross-linking points becomes long, so that the structure becomes more flexible. Thereby, the thermal impact resistance of the cured product of the pressure-sensitive adhesive composition can be further improved. Further, the thioether-containing (meth) acrylate derivative represented by the above formula 4, 7, or 9 easily forms a crosslinked network in the entire cured product of the pressure-sensitive adhesive composition, and the cured product has better moisture and heat resistance. show.

In the thioether-containing (meth) acrylate derivative represented by the above formula 4, the sum of d, e and f in the formula is 4, d is 2 or 3, respectively, e is 0 or 1, and f is. 1 or 2. Since the crosslinkability due to the photoreaction increases when the number of thiol groups is large, d is preferably 3 when it is desired to accelerate the curing reaction or improve the solvent resistance. Further, since the thioether group has lower hydrophilicity than the thiol group, f is preferably 2 when it is desired to improve the compatibility with a solvent having high hydrophobicity or when it is desired to improve the adhesion of the cured product. In the above formula 4, R ⁸ is a methylene group, an ethylene group or an isopropylene group, and R ⁹ is a divalent functional group represented by the above formula 5 or the formula 6. When R ⁹ is a functional group represented by the above formula 5, the adhesion of the cured product can be further improved, and when R 9 is a functional group represented by the above formula 6, the durability of the cured product can be further improved. Can be done. ^{R 10} in the above formula 5 is a methyl group or an ethyl group, and R ¹¹ is a hydrocarbon group having 1 to 12 carbon atoms, preferably 2 to 12 carbon atoms, and more preferably 2 to 12 carbon atoms. Is 4 to 12.

In the thioether-containing (meth) acrylate derivative represented by the above formula 7, the sum of g, h and i in the formula is 6, g is an integer of 2 to 5, and h is an integer of 0 to 2. Yes, i is an integer from 1 to 4. ^{Further, R 14} in the formula 7 has a structure represented by the above formula 8. Since the crosslinkability due to the photoreaction increases when the number of thiol groups is large, g is preferably 5 when it is desired to accelerate the curing reaction or improve the solvent resistance. Further, since the thioether group has lower hydrophilicity than the thiol group, i is preferably 4 when it is desired to improve the compatibility with a solvent having high hydrophobicity or when it is desired to improve the adhesion of the cured product. In the above formula 7, R ¹⁵ is a methylene group, an ethylene group or an isopropylene group, and R ¹⁶ is a divalent functional group represented by the above formula 5 or the formula 6. When R ¹⁶ is a functional group represented by the above formula 5, the adhesion of the cured product can be further improved, and when R 16 is a functional group represented by the above formula 6, the durability of the cured product can be further improved. Can be done. ^{R 17} in the above formula 7 is a methyl group or an ethyl group, and R ¹⁸ is a hydrocarbon group having 1 to 12 carbon atoms, preferably 2 to 12 carbon atoms, and more preferably 2 to 12 carbon atoms. Is 4 to 12.

In the thioether-containing (meth) acrylate derivative represented by the above formula 9, R ¹⁹ has a structure having an isocyanurate ring represented by the above formula 10. The thioether-containing (meth) acrylate derivative represented by the above formula 9 is preferable in that the flexibility can be further improved. ^{R 20} in the above formula 9 is a divalent functional group represented by the above formula 5 or the above formula 6, and R ²¹ is a hydrocarbon group having 1 to 12 carbon atoms, preferably 2 to 12 carbon atoms. It is more preferably 4 to 12 carbon atoms.

（式中のjは２〜６の整数である。Ｒ^２３は水素原子又はメチル基であり、Ｒ^２４は炭素数２〜１４の炭化水素基、炭素数２〜１４のエーテル酸素（−Ｏ−）と炭化水素基のみからなる基、又はイソシアヌレート環と炭化水素基のみからなる基である。）
上記式１１中のＲ^２３が水素原子の場合、チオールとの反応性に優れるため、粘着剤組成物は硬化性に優れる。一方、Ｒ^２３がメチル基の場合、チオールとの反応性が劣るため、粘着剤組成物は貯蔵安定性の観点で優れる。また、（Ｂ）成分として式１１で表される化合物を用いる場合、Ｒ^２４の官能基の種類によって粘着剤組成物の硬化物の性質を更に向上できる。具体的には、Ｒ^２４が炭素数２〜１２の炭化水素基の場合には密着性が向上し、炭素数が４〜９であると向上効果がより高いため更に好ましい。Ｒ^２４が炭素数２〜１２のエーテル酸素と炭化水素基のみからなる基の場合には柔軟性が向上し、炭素数が４〜９であると向上効果がより高いため更に好ましい。Ｒ^２４がイソシアヌレート環と炭素数１〜３の炭化水素基のみからなる基の場合には耐久性が向上し、炭素数が２又は３であると向上効果がより高いため更に好ましい。 <(B) Polyfunctional (meth) acrylate having 2 to 6 (meth) acrylic groups>
(B) A preferable example of the polyfunctional (meth) acrylate having 2 to 6 (meth) acrylic groups is a compound represented by the following formula 11. When the pressure-sensitive adhesive composition contains (B) polyfunctional (meth) acrylate, the moisture and heat resistance of the pressure-sensitive adhesive composition can be improved. On the other hand, when the number of (meth) acrylic groups contained in (B) polyfunctional (meth) acrylate is 7 or more, the adhesion of the cured product is lowered, which is not preferable. As the polyfunctional (meth) acrylate which is the component (B), only one kind may be used alone, or two or more kinds may be used in combination.

(J in the formula is an integer of 2 to 6. R ²³ is a hydrogen atom or a methyl group, R ²⁴ is a hydrocarbon group having 2 to 14 carbon atoms and ether oxygen having 2 to 14 carbon atoms (-O-). ) And a hydrocarbon group only, or an isocyanurate ring and a hydrocarbon group only.)
^{When R 23} in the above formula 11 is a hydrogen atom, the adhesive composition is excellent in curability because it is excellent in reactivity with thiol. On the other hand, when R ²³ is a methyl group, the reactivity with thiol is inferior, so that the pressure-sensitive adhesive composition is excellent from the viewpoint of storage stability. In addition, it further improves the properties of the cured product of the adhesive composition optionally, the type of the functional group of R ²⁴ using the compound of formula 11 as the component (B). Specifically, when R ²⁴ is a hydrocarbon group having 2 to 12 carbon atoms, the adhesion is improved, and when R 24 is 4 to 9 carbon atoms, the improving effect is higher, which is more preferable. When R ²⁴ is a group consisting only of ether oxygen having 2 to 12 carbon atoms and a hydrocarbon group, the flexibility is improved, and when R 24 is 4 to 9 carbon atoms, the improving effect is higher, which is more preferable. When R ²⁴ is a group consisting only of an isocyanurate ring and a hydrocarbon group having 1 to 3 carbon atoms, the durability is improved, and when the number of carbon atoms is 2 or 3, the improving effect is higher, which is more preferable.

Further, as the (B) polyfunctional (meth) acrylate, a polymer type can also be preferably used. The polymer-type polyfunctional (meth) acrylate has a (meth) acrylate having an epoxy group such as glycidyl (meth) acrylate alone or a copolymer having a group that reacts with an epoxy group such as (meth) acrylic acid. A polymer obtained by reacting a (meth) acrylate, a (meth) acrylate having a hydroxyl group such as hydroxyethyl (meth) acrylate alone or a copolymer has a hydroxyl group such as 2-isocyanatoethyl 2-methylpropenate. A polymer obtained by reacting a (meth) acrylate having a group that reacts with (meth) acrylic acid, a (meth) acrylate having a carboxyl group such as (meth) acrylic acid alone or a copolymer, and a carboxyl group such as glycidyl (meth) acrylate. Examples thereof include a polymer obtained by reacting a (meth) acrylate having a group that reacts with. Preferably, it is a polyfunctional (meth) acrylate having 2 to 4 (meth) acrylic groups, for example, glycerin dimethacrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, bisphenol A diglycidyl ether acrylic acid adduct. , Phenol novolac type diglycidyl ether acrylic acid adduct, bisphenol A diglycidyl ether methacrylic acid adduct and the like can be used.

<(C) Urethane (meth) acrylate>
The urethane (meth) acrylate as the component (C) is a compound represented by the above formula 1, a diisocyanate compound represented by the following formula 12, a diol compound represented by the following formula 13, and a table represented by the following formula 14. It can be obtained by reacting with a (meth) acrylate compound having a hydroxyl group. By containing (C) urethane (meth) acrylate in the pressure-sensitive adhesive composition, the coatability of the pressure-sensitive adhesive composition on the base material is improved, and the cohesive force and stickiness of the cured product of the pressure-sensitive adhesive composition are improved. It can be enhanced and the adhesion can be enhanced. As the urethane (meth) acrylate which is the component (C), only one kind may be used alone, or two or more kinds may be used in combination.

In the above formula 1, R ¹ is a hydrocarbon group having 1 to 14 carbon atoms, preferably 4 to 13 carbon atoms. R ² is a hydrocarbon group having 1 to 14 carbon atoms, a polyether group represented by the above formula 2, or a polyester group represented by the above formula 3. When R ² is a hydrocarbon group, the number of carbon atoms is preferably 2 to 12, and more preferably 4 to 9. R ³ is a hydrogen atom or a methyl group, and R ⁴ is a hydrocarbon group having 1 to 14 carbon atoms. The number of carbon atoms in R ⁴ is 2 to 12 are preferred, 4-9 is more preferable. ^{Further, R 5} in the above formula 2 is an independent hydrocarbon group having 2 to 14 carbon atoms, preferably 2 to 8 carbon atoms, and more preferably 2 to 6 carbon atoms. ^{R 6} and R ⁷ in the above formula 3 are hydrocarbon groups having 1 to 14 carbon atoms, and may be the same or different from each other. The hydrocarbon group of R ⁶ preferably has 2 to 12 carbon atoms, and more preferably 2 to 8 carbon atoms. The hydrocarbon group of R ⁷ preferably has 2 to 6 carbon atoms, and more preferably 2 to 4 carbon atoms.

（Ｒ^１は炭素数１〜１４の炭化水素基である。）
式１２中のＲ¹は炭素数４〜１３が好ましい。

（Ｒ^２は炭素数１〜１４の炭化水素基、上記式２で表されるポリエーテル基、又は上記式３で表されるポリエステル基である。）
式１３中のＲ^２が炭化水素基の場合、炭素数は２〜１２が好ましく、更に好ましくは、４〜９である。

（Ｒ^３は水素原子又はメチル基であり、Ｒ^４は炭素数１〜１４の炭化水素基である。）
式１４中のＲ^４の炭素数は２〜１２が好ましく、更に好ましくは４〜９である。

(R ¹ is a hydrocarbon group having 1 to 14 carbon atoms.)
^{R 1} in the formula 12 preferably has 4 to 13 carbon atoms.

(R ² is a hydrocarbon group having 1 to 14 carbon atoms, a polyether group represented by the above formula 2, or a polyester group represented by the above formula 3.)
^{When R 2} in the formula 13 is a hydrocarbon group, the number of carbon atoms is preferably 2 to 12, and more preferably 4 to 9.

(R ³ is a hydrogen atom or a methyl group, and R ⁴ is a hydrocarbon group having 1 to 14 carbon atoms.)
^{The carbon number of R 4} in the formula 14 is preferably 2 to 12, and more preferably 4 to 9.

As the diisocyanate compound represented by the formula 12, a known compound can be used, and it can be used alone or in combination of two or more.

As the diol compound represented by the formula 13, a diol having a hydrocarbon group having 1 to 14 carbon atoms, a polyether diol, and a polyester diol can be used, and each of them can be used alone or two or more kinds thereof. It can also be used together.

As the (meth) acrylate compound having a hydroxyl group represented by the formula 14, a known compound can be used.

The weight average molecular weight of the urethane (meth) acrylate (C) is preferably 1000 to 15000 from the viewpoint of ease of handling, coatability of the pressure-sensitive adhesive composition, and excellent adhesion. If the weight average molecular weight is less than 1000, the cohesive force of the cured product is reduced and the adhesion is lowered. On the other hand, when the weight average molecular weight is larger than 15,000, it is difficult to handle because of its high viscosity, and the coatability of the pressure-sensitive adhesive composition is deteriorated, which is not preferable.

（式中のＲ^２５は水素原子又はメチル基であり、Ｒ^２６は炭素数１〜２０の炭化水素基、炭素数１〜１４のエーテル酸素（−Ｏ−）と炭化水素基のみからなる基、１つ若しくは複数のヒドロキシル基が置換した炭素数１〜１４の炭化水素基、又は置換若しくは非置換のフェニル基である。）
式１５中のＲ^２６が炭化水素基の場合、炭素数は２〜１２が好ましく、４〜１２が更に好ましい。Ｒ^２６がエーテル酸素と炭化水素基のみからなる基の場合、炭素数は２〜１２が好ましく、４〜９が更に好ましい。Ｒ^２６が１つ若しくは複数のヒドロキシル基が置換した炭化水素基の場合、炭素数は２〜１２が好ましく、４〜１２が更に好ましい。 <Monofunctional (meth) acrylate having only one (D) (meth) acrylic group>
(D) The monofunctional (meth) acrylate having only one (meth) acrylic group is a compound having only one (meth) acrylic group in the molecule, and a preferable example thereof is a compound represented by the following formula 15. Can be mentioned. The pressure-resistant impact resistance can be improved by containing the monofunctional (meth) acrylate having only one (D) (meth) acrylic group in the pressure-sensitive adhesive composition. As the monofunctional (meth) acrylate having only one (meth) acrylic group as the component (D), only one type may be used alone, or two or more types may be used in combination.

^{(R 25} in the formula is a hydrogen atom or a methyl group, and R ²⁶ is a hydrocarbon group having 1 to 20 carbon atoms, a group consisting only of ether oxygen (−O−) having 1 to 14 carbon atoms and a hydrocarbon group. A hydrocarbon group having 1 to 14 carbon atoms substituted with one or more hydroxyl groups, or a substituted or unsubstituted phenyl group.)
^{When R 26} in the formula 15 is a hydrocarbon group, the number of carbon atoms is preferably 2 to 12, and more preferably 4 to 12. When R ²⁶ is a group consisting only of ether oxygen and a hydrocarbon group, the number of carbon atoms is preferably 2 to 12, and more preferably 4 to 9. When R ²⁶ is a hydrocarbon group substituted with one or more hydroxyl groups, the number of carbon atoms is preferably 2 to 12, and more preferably 4 to 12.

（Ｒ^２７は水素原子又はメチル基であり、Ｒ^２８は炭素数１〜４の炭化水素基である。）
式１６中のＲ^２８が炭素数１〜３の炭化水素基の場合、硬化物のバリア性が高く、より優れた耐久性が実現できるため更に好ましい。 <(E) Hydroxy group-containing (meth) acrylamide>
(E) The hydroxyl group-containing (meth) acrylamide is a compound containing a hydroxyl group in the molecule and having only one acrylamide group, and a preferable example thereof is a compound represented by the following formula 16. By containing (E) hydroxyl group-containing (meth) acrylamide in the pressure-sensitive adhesive composition, the moisture and heat resistance of the cured product of the pressure-sensitive adhesive composition can be enhanced. This is because even if water enters the cured product under high temperature and high humidity, the water collects near the hydroxyl group and is captured by the hydrogen bond of the hydroxyl group-containing (meth) acrylamide. Since the (meth) acrylamide group is not easily hydrolyzed, it is possible to retain the water without being hydrolyzed by the captured water, and as a result, the dispersion of the water is suppressed and the deterioration due to the hydrolysis of other components is suppressed. Therefore, the moisture and heat resistance is improved. On the other hand, when (meth) acrylamide containing no hydroxyl group is used, it becomes difficult for the (meth) acrylamide group to capture water, so that other components are hydrolyzed and the heat resistance to moisture and heat is lowered. The hydroxyl group-containing (meth) acrylamide, which is the component (E), may be used alone or in combination of two or more.

(R ²⁷ is a hydrogen atom or a methyl group, and R ²⁸ is a hydrocarbon group having 1 to 4 carbon atoms.)
^{When R 28} in the formula 16 is a hydrocarbon group having 1 to 3 carbon atoms, it is more preferable because the barrier property of the cured product is high and more excellent durability can be realized.

<Additives>
In the pressure-sensitive adhesive composition, a photopolymerization initiator that improves the curability of the pressure-sensitive adhesive composition and ultraviolet rays (UV) are appropriately absorbed by active energy rays such as ultraviolet rays (UV) to cure the pressure-sensitive adhesive composition. An ultraviolet absorber that improves the light resistance of the cured product, a light stabilizer that captures radicals generated in the cured product obtained by curing the pressure-sensitive adhesive composition, and a light stabilizer that improves the light resistance of the cured product, the pressure-sensitive adhesive composition. Additives such as a polymerization inhibitor that improves the storage stability of the product and a tackifier that improves the adhesion of the cured product obtained by curing the pressure-sensitive adhesive composition can be added.

<Composition ratio (blending balance)>
The pressure-sensitive adhesive composition of the present invention contains (A) 5 to 25 parts by mass of polyfunctional (meth) acrylate and (C) urethane with respect to 100 parts by mass of a polyfunctional thiol compound having 2 to 6 thiol groups. 80 to 200 parts by mass of (meth) acrylate, 30 to 150 parts by mass of monofunctional (meth) acrylate having only one (D) (meth) acrylic group, and 5 to 5 parts by mass of (E) hydroxyl group-containing (meth) acrylamide. It is blended so as to have a ratio of 25 parts by mass. (B) When the blending amount of the polyfunctional (meth) acrylate is less than 5 parts by mass, the toughness of the cured product tends to decrease, and the moist heat resistance tends to decrease. (B) When the blending amount of the polyfunctional (meth) acrylate exceeds 25 parts by mass, the flexibility of the cured product is insufficient, the heat impact resistance is inferior, and the heat resistance and adhesion tend to be lowered. When the blending amount of the urethane (meth) acrylate (C) is less than 80 parts by mass, the cohesive force of the cured product obtained by curing the pressure-sensitive adhesive composition is lowered, and the moist heat resistance and the adhesiveness tend to be inferior. When the blending amount of the urethane (meth) acrylate (C) exceeds 200 parts by mass, the flexibility of the cured product is insufficient and the heat impact resistance tends to be inferior. (D) When the blending amount of the monofunctional (meth) acrylate having only one (meth) acrylic group is less than 30 parts by mass, the pressure-sensitive adhesive composition tends to be too hard and the thermal shock resistance tends to be inferior. (D) When the blending amount of the monofunctional (meth) acrylate exceeds 150 parts by mass, the cross-linking density is lowered, and the adhesion, moisture heat resistance, and heat impact resistance tend to be inferior. (E) When the blending amount of the hydroxyl group-containing (meth) acrylamide is less than 5 parts by mass, the moisture and heat resistance of the cured product tends to be inferior. (E) When the blending amount of the hydroxyl group-containing (meth) acrylamide exceeds 25 parts by mass, the Tg of the composition tends to be high and the thermal impact resistance tends to be inferior.

<Laminated body>
In the laminate of the present invention, an uncured pressure-sensitive adhesive layer made of the above-mentioned pressure-sensitive adhesive composition is laminated on one surface of a transparent base material, and the base material can be further laminated on the pressure-sensitive adhesive layer. Further, in the laminated body in which the pressure-sensitive adhesive layer and the base material are laminated on the transparent base material, the pressure-sensitive adhesive layer may be cured.

The film thickness of the adhesive layer of the laminated body is usually 25 to 1,000 μm, preferably 50 to 900 μm, and more preferably 80 to 800 μm. If the film thickness exceeds 1,000 μm, the amount of the pressure-sensitive adhesive composition required is large, which makes application difficult. On the other hand, if the film thickness is thinner than 25 μm, it becomes difficult to make the film thickness uniform, which is not preferable.

<Base material>
As the transparent base material to which the pressure-sensitive adhesive composition is applied, a base material having a total light transmittance of 70% or more can be used. Examples of the transparent base material include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, cellulose films such as triacetyl cellulose, polyurethane films, polyurethane acrylate films, polyethylene films, polypropylene films, polyvinyl chloride films, and poly. Plastic films such as vinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, acrylic resin film, norbornene-based resin film, cycloolefin resin film, and liquid crystal polymer film can be used.

Further, as the base material laminated on the adhesive layer, an opaque base material having a total light transmittance of less than 70% can be used in addition to the above transparent base material. For example, high-quality paper, paper such as glassin paper, metal foils of aluminum, copper, and iron, glass fibers, natural fibers, synthetic fibers, and other woven fabrics and non-woven fabrics can be used.

Functional layers such as a mold release treatment layer, an easy-adhesion layer, a hard coat layer, an antireflection layer, a transparent conductive layer, and an electromagnetic wave shielding layer are provided on one side or both sides of these transparent base materials or opaque base materials. Is also good.

The thickness of the transparent base material and the base material is preferably 10 to 500 μm. When the thickness of the base material is thinner than 10 μm or thicker than 500 μm, the handleability at the time of use is lowered, which is not preferable.

<Formation of laminate>
The laminate is composed of (1) a step of applying an adhesive composition to one surface of a transparent base material to form an adhesive layer, (2) a step of laminating the base material on the adhesive layer, and (3) adhesiveness. It is produced by performing only (1), (1) and (2), or (1) to (3) in the steps of curing the layer. When the steps (1) to (3) are performed, the order of the steps (2) and (3) may be reversed. That is, the base material may be laminated on the uncured adhesive layer and then the adhesive layer may be cured, or the adhesive layer may be cured and then the base material may be laminated.

The coating method of the pressure-sensitive adhesive composition is not particularly limited, and known coating methods such as a roll coating method, a reverse coating method, a blade coating method, a bar coating method, a knife coating method, a die coating method, and a gravure coating method can be adopted.

The method for curing the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition is not particularly limited, and the pressure-sensitive adhesive layer can be cured by heat, ultraviolet rays (UV), or electron beam (EB).

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The components used in this example and the comparative example are as follows. The term "examples and comparative examples" includes reference examples in addition to the examples and comparative examples.

Ａ−５：下記式１８の多官能チオール化合物

Ａ−６：下記式１９の多官能チオール化合物

Ａ−７：下記式２０の多官能チオール化合物

Ａ−８：下記式２１の多官能チオール化合物

Ａ−９：下記式２２の多官能チオール化合物

Ａ’−１：１−オクタンチオール
＜（Ｂ）成分＞
Ｂ−１：ジメチロール−トリシクロデカンジアクリレート
Ｂ−２：ジペンタエリスリトールヘキサアクリレート
Ｂ−３：エトキシ化イソシアヌル酸トリアクリレート
Ｂ−４：ビスフェノールＡのＥＯ付加物ジメタクリレート
Ｂ−５：トリメチロールプロパントリメタクリレート
Ｂ−６：１，６−ヘキサンジオールジメタクリレート
＜（Ｄ）成分＞
Ｄ−１：２−エチルヘキシルアクリレート
Ｄ−２：イソボニルアクリレート
Ｄ−３：２−ヒドロキシエチルアクリレート
Ｄ−４：４−ヒドロキシブチルアクリレート
Ｄ−５：テトラヒドロフルフリルアクリレート
＜（Ｅ）成分＞
Ｅ−１：Ｎ−(２−ヒドロキシメチル)アクリルアミド
Ｅ−２：Ｎ−(２−ヒドロキシエチル)アクリルアミド
Ｅ−３：Ｎ−(２−ヒドロキシプロピル)アクリルアミド
Ｅ’−１：ジメチルアクリルアミド
Ｅ’−２：アクリルロイルアクリルアミド <Ingredient (A)>
A-1: Trimethylolpropanetris (3-mercaptopropionate)
A-2: Dipentaerythritol hexakis (3-mercaptopropionate)
A-3: Tris-[(3-mercaptopropionyloxy) -ethyl] -isocyanurate A-4: Polyfunctional thiol compound of the following formula 17

A-5: Polyfunctional thiol compound of the following formula 18

A-6: Polyfunctional thiol compound of the following formula 19

A-7: Polyfunctional thiol compound of the following formula 20

A-8: Polyfunctional thiol compound of the following formula 21

A-9: Polyfunctional thiol compound of the following formula 22

A'-1: 1-octane thiol <(B) component>
B-1: Dimethylol-tricyclodecanediacrylate B-2: Dipentaerythritol hexaacrylate B-3: Ethoxylated isocyanuric acid triacrylate B-4: EO adduct of bisphenol A Dimethacrylate B-5: Trimethylolpropanetri Methacrylate B-6: 1,6-hexanediol dimethacrylate <component (D)>
D-1: 2-Ethylhexyl acrylate D-2: Isobonyl acrylate D-3: 2-Hydroxyethyl acrylate D-4: 4-Hydroxybutyl acrylate D-5: Tetrahydrofurfuryl acrylate <(E) component>
E-1: N- (2-Hydroxymethyl) Acrylamide E-2: N- (2-Hydroxyethyl) Acrylamide E-3: N- (2-Hydroxypropyl) Acrylamide E'-1: Dimethylacrylamide E'-2 : Acrylic loyl acrylamide

<Manufacturing of component (C)>
(Production of diol compound (c-1))
A reaction vessel equipped with a stirrer, a rectification tower, a nitrogen introduction tube, and a thermometer was charged with 150.2 parts by mass of adipate and 161.3 parts by mass of 3-methyl-1,5-pentanediol, and 140 by mass under a nitrogen atmosphere. The mixture was heated to ° C and stirred. To this, 0.01 part by mass of tetrabutyl titanate was charged, the temperature was raised to 220 ° C., and a dehydration reaction was carried out. Then, it was continuously held at 220 ° C. and a dehydration reaction was carried out. After 18 hours from the start of the dehydration reaction, the contents were cooled to obtain a diol compound (c-1) (weight average molecular weight: 1600).

(Production of diol compound (c-2))
A reaction vessel equipped with a stirrer, a rectification tower, a nitrogen introduction tube, and a thermometer was charged with 158.5 parts by mass of pimeric acid and 202.1 parts by mass of 3-methyl-1,5-pentanediol, and 140 parts by mass under a nitrogen atmosphere. The mixture was heated to ° C and stirred. To this, 0.01 part by mass of tetrabutyl titanate was charged, the temperature was raised to 220 ° C., and a dehydration reaction was carried out. Then, it was continuously held at 220 ° C. and a dehydration reaction was carried out. After 18 hours from the start of the dehydration reaction, the contents were cooled to obtain a diol compound (c-2) (weight average molecular weight: 1750).

(Manufacturing of urethane (meth) acrylate)
160.3 parts by mass of the diol compound (c-1) was charged into a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen introduction tube, and a thermometer, and stirring was started. Next, 0.1 part by mass of dibutyltin laurate and 77.4 parts by mass of 1,6-diisocyanate-2,2,4-trimethylhexane as diisocyanate were added, and the internal temperature was raised to 80 ° C. while paying attention to heat generation. After that, the mixture was stirred for 3 hours while maintaining the temperature. Further, 0.1 part by mass of methquinone as a polymerization inhibitor and 31.2 parts by mass of propylene glycol monoacrylate as an acrylate were added, and the mixture was stirred at 85 ° C. for 2 hours to obtain urethane (meth) acrylate (C-1). Obtained (weight average molecular weight: 9500).

Urethane (meth) acrylates (C-2) to (C-5) were obtained in the same manner as in the above method except that the diol compound, diisocyanate, and acrylate shown in Table 1 below were used.

<Manufacturing of adhesive composition>
Each component was added to the stirring pot as shown in Tables 2 to 5 below, mixed for 2 hours, and stirred to obtain the pressure-sensitive adhesive compositions of each Example and Comparative Example.

<Manufacturing of laminate>
<Manufacturing of laminated body 1>
On a transparent substrate (PET, thickness: 100 μm, total light transmittance: 91%, manufactured by Toyobo Co., Ltd. (product number: A4100)), the pressure-sensitive adhesive compositions of the respective Examples and Comparative Examples have a thickness of 500 μm by a die coater. A base material (PC, thickness: 125 μm, total light transmittance: 90%, made of Escalbo sheet (product number C000)) was placed on the formed adhesive layer and laminated. Then, ultraviolet irradiation (700 mJ / cm ² ) was performed using a metal halide lamp to cure the adhesive layer to obtain a laminated body 1 of each Example and Comparative Example.

<Manufacturing of laminated body 2>
On a transparent base material (PC, thickness: 125 μm, total light transmittance: 90%, made of escabo sheet (product number C000)), the pressure-sensitive adhesive compositions of each example and comparative example were applied to a thickness of 500 μm by a die coater. A base material (glass, thickness: 0.7 mm, total light transmittance: 91%, manufactured by Corning Inc. (product number: EAGLE XG)) was placed on the formed adhesive layer and laminated. .. Then, ultraviolet irradiation (700 mJ / cm ² ) was performed using a metal halide lamp to cure the adhesive layer to obtain a laminated body 2 of each Example and Comparative Example.

<Evaluation method>
The properties of the pressure-sensitive adhesive compositions and laminates obtained in each Example and Comparative Example were evaluated by the methods described below. The evaluation results are shown in Tables 2 to 5 above.

Adhesion The adhesion of the laminate 1 of each Example and Comparative Example was measured using a desktop material tester (STA-1150 manufactured by Orientec Co., Ltd.) according to JISZ0237: 2009 (peeling speed: 300 mm / min). , 180 degree peel force test).
◯: 15N / 20mm or more ×: 15N / less than 20mm

・ Moisture resistance 1 (durability)
The laminate 1 of each Example and Comparative Example was cut into a size of 50 mm in length and 50 mm in width, and the haze value of the obtained sample was measured with a haze meter (NDH2000 manufactured by Nippon Denshoku Kogyo Co., Ltd.). After the measurement, the sample was allowed to stand in a constant temperature and humidity tester at 60 ° C. and 95% RH for 1000 hours. Then, the sample was taken out from a constant temperature and humidity tester, allowed to stand at 23 ° C. and 50% RH for 30 minutes, and then the appearance of the sample was visually observed and the haze value was measured by a haze meter (NDH2000 manufactured by Nippon Denshoku Kogyo Co., Ltd.). Measured at.
◯: There was no peeling in the appearance of the sample, no abnormality such as liquid dripping of the adhesive composition, and the change value of the haze value before and after the treatment with the constant temperature and humidity tester (haze value before treatment-haze after treatment). Value) is less than ± 3%.
X: There is an abnormality such as peeling, foaming, and liquid dripping of the pressure-sensitive adhesive composition on the appearance of the sample. Alternatively, the change value of the haze value (haze value before treatment-haze value after treatment) before and after the treatment with the constant temperature and humidity tester is ± 3% or more.

・ Moisture resistance 2 (durability)
The laminate 1 of each Example and Comparative Example was cut into a size of 50 mm in length and 50 mm in width, and the haze value of the obtained sample was measured with a haze meter (NDH2000 manufactured by Nippon Denshoku Kogyo Co., Ltd.). After the measurement, the sample was allowed to stand in a constant temperature and humidity tester at 85 ° C. and 85% RH for 2000 hours. Then, the sample was taken out from a constant temperature and humidity tester, allowed to stand at 23 ° C. and 50% RH for 30 minutes, and then the appearance of the sample was visually observed and the haze value was measured by a haze meter (NDH2000 manufactured by Nippon Denshoku Kogyo Co., Ltd.). Measured at.
◯: There was no peeling in the appearance of the sample, no abnormality such as liquid dripping of the adhesive composition, and the change value of the haze value before and after the treatment with the constant temperature and humidity tester (haze value before treatment-haze after treatment). Value) is less than ± 3%.
X: There is an abnormality such as peeling, foaming, and liquid dripping of the pressure-sensitive adhesive composition on the appearance of the sample. Alternatively, the change value of the haze value (haze value before treatment-haze value after treatment) before and after the treatment with the constant temperature and humidity tester is ± 3% or more.

・ Heat resistance (flexibility)
The laminate 1 and the laminate 2 of each Example and Comparative Example were cut into a size of 150 mm in length and 200 mm in width, and the haze value of the obtained sample was measured with a haze meter (NDH2000 manufactured by Nippon Denshoku Kogyo Co., Ltd.). After the measurement, the sample was treated with a thermal shock tester for 300 cycles under the following test conditions.
-High temperature side test condition: 95 ° C., 30 minutes-Low temperature side test condition: -40 ° C, 30 minutes After that, the sample is taken out from the thermal shock tester and allowed to stand at 23 ° C., 50% RH for 30 minutes, and then the sample. The appearance of the above was visually observed, and the haze value was measured with a haze meter (NDH2000 manufactured by Nippon Denshoku Kogyo Co., Ltd.).
⊚: In the laminated body 1 and the laminated body 2, there was no abnormality such as peeling in the appearance of the sample and liquid dripping of the pressure-sensitive adhesive composition, and the change value of the haze value before and after the treatment with the constant temperature and humidity tester (treatment). The previous haze value-the haze value after processing) is less than ± 3%.
◯: In the laminated body 2, the appearance of the sample is peeled off, and there are abnormalities such as foaming and liquid dripping of the pressure-sensitive adhesive composition. In addition, there is no peeling in the appearance of the sample in the laminate 1 and no abnormality such as liquid dripping of the pressure-sensitive adhesive composition, and the change value of the haze value before and after the treatment with the constant temperature and humidity tester (the haze value before the treatment). -Haze value after processing) is less than ± 3%.
X: In the laminated body 1 and the laminated body 2, there are abnormalities such as peeling, foaming, and liquid dripping of the pressure-sensitive adhesive composition in the appearance of the sample. Alternatively, the change value of the haze value (haze value before treatment-haze value after treatment) before and after the treatment with the constant temperature and humidity tester is ± 3% or more.

-Storage stability Immediately after mixing the pressure-sensitive adhesive compositions of each Example and Comparative Example, the viscosity at 25 ° C. (viscosity immediately after mixing) was measured, and after heating at 50 ° C. for 60 days, the viscosity (viscosity after heating) was measured again. ) Was measured, and the viscosity after heating was divided by the viscosity immediately after mixing to calculate the thickening rate, which was evaluated as follows. The viscosity was measured using an R-type viscometer RE-85U manufactured by Toki Sangyo Co., Ltd. under the following conditions.
Rotor used: 1 ° 34'x R24
Measurement range: 0.5183 to 103.7 Pa · s
⊚: Thickness thickening rate is less than 1.02 ○: Thickness thickening rate is 1.02 or more and less than 1.50 ×: Thickness thickening rate is 1.50 or more

As a result of each of the above tests, the pressure-sensitive adhesive compositions of the Examples and Reference Examples had excellent adhesion, moisture heat resistance (durability), heat impact resistance (flexibility), and storage stability. On the other hand, Comparative Example 1-1 was inferior in moisture and heat resistance because the component (B) was too small. In Comparative Example 1-2, since the component (B) was too large, the adhesion, the heat resistance to moisture and heat resistance, and the heat impact resistance were inferior. In Comparative Examples 1-3, the amount of the component (C) was too small, so that the adhesion and the heat resistance to moisture were inferior. In Comparative Examples 1-4, the heat impact resistance was inferior because the component (C) was too large. Comparative Example 1-5 was inferior in thermal impact resistance because the component (D) was too small. In Comparative Example 1-6, since the component (D) was too large, the adhesion, the heat resistance to moisture and heat, and the heat impact resistance were inferior. Comparative Example 1-7 was inferior in moisture and heat resistance because the component (E) was too small. In Comparative Example 1-8, since the component (E) was too large, the heat resistance to moisture and heat resistance and the heat impact resistance were inferior. Comparative Examples 1-9 and 1-10 were inferior in moisture and heat resistance because the component (E) did not have a hydroxyl group. In Comparative Example 1-11, since the component (A) had only one thiol group, the adhesion, the heat resistance to moisture and heat resistance, and the heat impact resistance were inferior.

Claims (7)

(A) A polyfunctional thiol compound having 2 to 6 thiol groups and
(B) Polyfunctional (meth) acrylate having 2 to 6 (meth) acrylic groups and
(C) Urethane (meth) acrylate having a weight average molecular weight of 1000 to 15000 represented by the following formula 1 and
(D) Monofunctional (meth) acrylate having only one (meth) acrylic group and
(E) A pressure-sensitive adhesive composition containing a hydroxyl group-containing (meth) acrylamide.
(A) When a polyfunctional thiol compound having 2 to 6 thiol groups is taken as 100 parts by mass,
(B) Polyfunctional (meth) acrylate: 5 to 25 parts by mass (C) Urethane (meth) acrylate: 150 to 200 parts by mass (D) Monofunctional (meth) acrylate: 30 to 150 parts by mass (E) Containing hydroxyl groups (Meta) Acrylamide: A pressure-sensitive adhesive composition contained in a ratio of 5 to 15 parts by mass.

(A in the formula is an integer of ¹ to 15. R 1 is a hydrocarbon group ^{having 1 to 14 carbon atoms, R 2} is a hydrocarbon group having 1 to 14 carbon atoms, and the poly represented by the following formula 2. It is an ether group or a polyester group represented by the following formula 3, R ³ is a hydrogen atom or a methyl group, and R ⁴ is a hydrocarbon group having 1 to 14 carbon atoms.

(B in the formula is an integer of 1 to 20. R ⁵ is an independent hydrocarbon group having 2 to 14 carbon atoms.)

(C in the formula is an integer of 1 to 20. R ⁶ and R ⁷ are hydrocarbon groups having 1 to 14 carbon atoms, which may be the same or different from each other.) The pressure-sensitive adhesive composition according to claim 1, wherein the polyfunctional thiol compound having 2 to 6 thiol groups (A) is a polyfunctional thiol compound represented by the following formula 4.

(D in the formula is 2 or 3, e is 0 or 1, f is 1 or 2, and the sum of d, e and f is 4. R ⁸ is a methylene group, an ethylene group or It is an ^{isopropylene group, R 9} is a divalent functional group represented by the following formula 5 or formula 6, R ¹⁰ is a methyl group or an ethyl group, and R ¹¹ has 1 to 12 carbon atoms. It is a hydrocarbon group of.)

^{(R 12} in the formula is a hydrogen atom or a methyl group.)

^{(R 13} in the formula is a hydrogen atom or a methyl group.) The pressure-sensitive adhesive composition according to claim 1, wherein the polyfunctional thiol compound having 2 to 6 thiol groups (A) is a polyfunctional thiol compound represented by the following formula 7.

(G in the formula is an integer of 2 to 5, h is an integer of 0 to 2, i is an integer of 1 to 4, and the sum of g, h, and i is 6. R ¹⁴ is as follows. It is a hexavalent functional group represented by the formula 8, R ¹⁵ is a methylene group, an ethylene group or an isopropylene group, and R ¹⁶ is a divalent functional group represented by the following formula 5 or formula 6. Yes, R ¹⁷ is a methyl group or an ethyl group, and R ¹⁸ is a hydrocarbon group having 1 to 12 carbon atoms.)

^{(R 12} in the formula is a hydrogen atom or a methyl group.)

^{(R 13} in the formula is a hydrogen atom or a methyl group.)

The pressure-sensitive adhesive composition according to claim 1, wherein the polyfunctional thiol compound having 2 to 6 thiol groups (A) is a polyfunctional thiol compound represented by the following formula 9.

(R ¹⁹ in the formula is a trivalent functional group represented by the following formula 10, R ²⁰ is a divalent functional group represented by the following formula 5 or formula 6, and R ²¹ has 1 carbon number. ~ 12 hydrocarbon groups.)

^{(R 22} in the formula is a methylene group, an ethylene group or an isopropylene group.)

^{(R 12} in the formula is a hydrogen atom or a methyl group.)

^{(R 13} in the formula is a hydrogen atom or a methyl group.) A laminate in which an uncured pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition according to any one of claims 1 to 4 is laminated on one surface of a transparent base material. A laminate in which an uncured pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive composition according to any one of claims 1 to 4 and a base material are laminated in this order on one surface of a transparent base material. A laminate in which a pressure-sensitive adhesive layer on which the pressure-sensitive adhesive composition according to any one of claims 1 to 4 is cured and a base material are laminated in this order on one surface of a transparent base material.