KR20230111601A - adhesive sheet - Google Patents

Abstract

A pressure-sensitive adhesive sheet capable of temporarily fixing an adherend in a peelable manner, exhibiting peelability with low-power laser light, making a process of washing the adherend unnecessary after peeling, and having a narrow range of areas where peeling occurs. The pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer and a transfer layer disposed on one side of the pressure-sensitive adhesive layer, the transfer layer is a layer that is cured by irradiation with active energy rays, the adhesive strength I of the pressure-sensitive adhesive sheet at 23°C when the pressure-sensitive adhesive layer is adhered to glass is 2 N/20 mm or more, and the adhesive strength I of the pressure-sensitive adhesive sheet at 23°C when the pressure-sensitive adhesive layer is bonded to glass is equivalent to the transfer layer The ratio to the adhesive force B at 23°C after irradiation with 300 mJ/cm ² ultraviolet rays is 5 or more.

Description

adhesive sheet

The present invention relates to an adhesive sheet.

When processing various members typified by electronic components, it is generally practiced to temporarily fix the member to a support using an adhesive sheet, and to peel the processed member from the support after transferring, processing, or the like. For example, Patent Document 1 describes a method in which a substrate (member to be processed) is processed while temporarily fixed to a support body via an adhesive layer and a separation layer, and after processing, the separation layer is destroyed by laser light irradiation, the substrate is separated from the support body for each adhesive layer, and thereafter, the adhesive layer is removed from the substrate. However, the above method requires a step of removing the adhesive layer from the member and cleaning the non-adhesive surface of the member, and there is a problem in terms of production cost. In addition, there is also a problem that the member is damaged when the laser beam is irradiated with high output.

Further, Patent Literature 2 describes a method of temporarily fixing a plurality of workpiece members to a carrier via an adhesive layer, and concentrating a laser beam on the adhesive layer to generate blisters, thereby selectively separating and transferring a part of the workpiece members from the carrier. However, in this method, there is a problem that blisters generated after laser irradiation spread over time, and as a result, separation of the carrier and unnecessary detachment of the workpiece member that does not require transfer occur.

Patent No. 5875850 Patent No. 6053756

The present invention has been made in order to solve the above conventional problems, and its object is to provide an adhesive sheet capable of temporarily fixing an adherend in a peelable manner, exhibiting peelability with a low-power laser beam, eliminating the need for a step of cleaning the adherend after peeling, and having a narrow range of peeling occurrence sites.

The pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer and a transfer layer disposed on one side of the pressure-sensitive adhesive layer, wherein the transfer layer is a layer that is cured by irradiation with active energy rays, the adhesive strength I at 23°C when the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is adhered to a glass plate is 2 N/20 mm or more, and the adhesive strength I at 23°C when the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is adhered to a glass plate is the transfer The ratio to the adhesive strength B at 23° C. after irradiating the layer with 300 mJ/cm ² ultraviolet rays is 5 or more.

In one embodiment, the pressure-sensitive adhesive sheet further includes a substrate between the pressure-sensitive adhesive layer and the transfer layer.

In one embodiment, after irradiation with ultraviolet rays of 300 mJ/cm ² , the indentation elastic modulus B at 23°C of the transfer layer is 5 times or more than the indentation elastic modulus I at 23°C of the pressure-sensitive adhesive layer.

In one embodiment, the transfer layer contains an active energy ray-curable pressure-sensitive adhesive, and the active energy ray-curable pressure-sensitive adhesive contains an acrylic polymer as a base polymer.

In one embodiment, the pressure-sensitive adhesive sheet is used to temporarily fix a member to a support body using the pressure-sensitive adhesive sheet, and to peel the member from the support body by laser light irradiation after transfer and/or processing.

According to the present invention, it is possible to provide an adhesive sheet capable of temporarily fixing an adherend in a peelable manner, exhibiting peelability with a low-power laser beam, eliminating the need for a step of washing the adherend after peeling, and having a narrow range of areas where peeling occurs.

1(a) is a schematic cross-sectional view of an adhesive sheet according to one embodiment of the present invention. (b) is a schematic cross-sectional view of an adhesive sheet according to another embodiment of the present invention.
Fig. 2(a) is a photomicrograph of the surface of the transfer layer in Example 1. (b) is a photomicrograph of the surface of the transfer layer in Comparative Example 1.

A. Outline of adhesive sheet

1(a) is a schematic cross-sectional view of an adhesive sheet according to one embodiment of the present invention. The PSA sheet 100 according to this embodiment includes an PSA layer 10 and a transfer layer 20 disposed on one side of the PSA layer 10 . 1(b) is a schematic cross-sectional view of an adhesive sheet according to another embodiment of the present invention. The PSA sheet 200 according to this embodiment further includes a substrate 30 between the PSA layer 10 and the transfer layer 20 . Although not shown, the pressure-sensitive adhesive sheet of the present invention may be provided with a release liner on the outside of the pressure-sensitive adhesive layer and transfer layer for the purpose of protecting the adhesive surface during use. In addition, the adhesive sheet may further contain any appropriate other layer as long as the effect of the present invention is obtained.

The PSA sheet of the present invention can be used for temporarily fixing a member to a support (eg, glass base) using the PSA sheet, and then peeling the member from the support after transfer, processing, and the like. At the time of peeling, laser light irradiation is performed, and only the member in a desired position can be peeled with pinpoint.

The said transfer layer is a layer hardened|cured by irradiation of an active energy ray. More specifically, the transfer layer has adhesiveness for fixing an adherend, and is cured by irradiation with active energy rays to lower the adhesiveness. Even after curing, it is preferable that the adhesive force to the extent that the adherend can be fixed (for example, the adhesive force to the extent that the adherend does not fall naturally) remains. In one embodiment, the adhesive strength of the entire transfer layer is reduced by irradiating the active energy ray. Examples of active energy rays include gamma rays, ultraviolet rays, visible rays, infrared rays (heat rays), radio waves, alpha rays, beta rays, electron rays, plasmas, ionizing rays, and particle rays. Preferably, it is ultraviolet.

The pressure-sensitive adhesive layer may have any suitable structure as long as the effects of the present invention are obtained. In one embodiment, the pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive. The pressure-sensitive adhesive sheet may be used by adhering the pressure-sensitive adhesive layer to a support (eg, glass substrate). In the pressure-sensitive adhesive sheet, partial deformation occurs in the pressure-sensitive adhesive layer (or the base material in the configuration having a base material) by laser light irradiation, and this strain is propagated to the transfer layer, and the surface of the transfer layer (adhesive surface) temporarily changes shape, thereby making it possible to peel off the adherend placed at the location. In the present invention, by adjusting the components of the pressure-sensitive adhesive layer (for example, the type of base polymer; the type of additives such as tackifier and crosslinking agent; their compounding amounts, etc.), the pressure-sensitive adhesive layer can absorb laser light of a predetermined wavelength, and as a result, the pressure-sensitive adhesive layer is easily deformed. The base material can also be made into a base material that is easily deformed by appropriately selecting the constituent material thereof. In addition, by performing laser beam irradiation after curing the transfer layer as described above, peelability by strain propagation can be favorably developed. In the present invention, since peelability is developed by the above action, a high-output laser light is not required, a step of washing the adherend after peeling is unnecessary, and the peeling occurrence site can be narrowed. In addition, after peeling, the change in the surface shape of the transfer layer does not continue (i.e., it does not widen over time, but rather can return to the shape before the change), and therefore, in a location where peeling is not desired, problems such as unnecessarily falling off of the adherend can be prevented.

The adhesive strength I at 23°C when the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is adhered to the glass plate is 2 N/20 mm or more. By increasing the adhesive force I, deformation of each layer due to laser light irradiation can be made suitable, and peeling occurrence areas can be made within a narrow range, and in areas where peeling is not desired, problems such as unnecessarily falling off of adherends can be prevented. The adhesive strength I is preferably 2 N/20 mm to 25 N/20 mm, more preferably 5 N/20 mm to 20 N/20 mm. In such a range, the effect of the present invention described above becomes remarkable. Adhesion is measured according to JIS Z 0237:2000. Specifically, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet was adhered to a glass plate (arithmetic average surface roughness Ra: 50 ± 25 nm) by reciprocating a 2 kg roller, and left at 23 ° C. for 30 minutes. Then, the pressure-sensitive adhesive sheet was peeled off under conditions of a peeling angle of 180 ° and a peeling speed (tensile speed) of 300 mm / min.

The initial adhesive force A at 23° C. immediately after the transfer layer of the pressure-sensitive adhesive sheet is adhered to the stainless plate is preferably 1 N/20 mm to 20 N/20 mm, more preferably 1.5 N/20 mm to 15 N/20 mm, still more preferably 2 N/20 mm to 10 N/20 mm. If it is this range, the adhesive sheet which can hold|maintain an adherend satisfactorily can be obtained. The adhesive force on the transfer layer side is also measured according to JIS Z 0237:2000. Specifically, the transfer layer of the adhesive sheet was adhered to a stainless steel plate (arithmetic mean surface roughness Ra: 50 ± 25 nm) by one reciprocation of a 2 kg roller, left at 23 ° C. for 30 minutes, and then peeled off at a peel angle of 180 ° and a peel rate (tensile speed) of 300 mm / min. The adhesive sheet was peeled off and measured. The adhesive force of the transfer layer changes with active energy ray irradiation and laser light irradiation. In this specification, "initial adhesive strength" means the adhesive force before irradiation with active energy ray and laser light.

In one embodiment, the adhesive sheet has an adhesive strength B at 23° C. (also referred to as adhesive strength B after curing) after the adhesive sheet is adhered to the stainless plate and the transfer layer is irradiated with ultraviolet rays of 300 mJ/cm ² . It becomes 1N/20mm or less. Within this range, a pressure-sensitive adhesive sheet having excellent peelability and a small amount of adhesive residue can be obtained. The lower limit of the adhesive force B after curing is, for example, 0.01 N/20 mm (preferably 0.001 N/20 mm). The ultraviolet irradiation is performed by irradiating the transfer layer with ultraviolet rays (characteristic wavelength: 365 nm, integrated light amount: 300 mJ/cm ² ) of a high-pressure mercury lamp using, for example, an ultraviolet irradiation device (manufactured by Nitto Seiki Co., Ltd., trade name “UM-810”). Ultraviolet irradiation may be performed from the side of the pressure-sensitive adhesive layer.

The ratio of the adhesive strength I at 23° C. to the adhesive strength B after curing of the transfer layer when the pressure-sensitive adhesive layer is adhered to glass (adhesive strength I/adhesive strength after curing B) is 5 or more. In other words, in the adhesive sheet, the adhesive strength B after curing is 0.2 times or less (preferably 0.1 times or less, more preferably 0.05 times or less, still more preferably 0.005 times or less) of the adhesive strength I. By specifying (adhesive force I/adhesive force after curing) as described above, deformation of each layer due to laser light irradiation can be made appropriate, and an adhesive sheet having excellent peelability by laser light irradiation can be obtained. Such an adhesive sheet can realize reliable peelability in a narrow range. (Adhesive strength I/Adhesive strength after curing B) is preferably 10 or more, more preferably 20 or more, still more preferably 200 or more. In such a range, the effect of the present invention described above becomes remarkable. The upper limit of (adhesive force I/adhesive force after curing B) is, for example, 1000, preferably 5000, and more preferably 10000. That is, in the adhesive sheet, the adhesive force B after curing can be 0.0001 times or more of the adhesive force I.

The ratio of the initial adhesive force A of the transfer layer to the adhesive force B after curing of the transfer layer (initial adhesive force A/adhesive force after curing B) is preferably 5 or more, more preferably 10 or more, more preferably 10 to 100, and still more preferably 30 to 80. If it is this range, the adhesive sheet excellent in the balance of the fixation property of a to-be-adhered body and peelability can be obtained.

In the pressure-sensitive adhesive sheet, the anchoring force at 23 ° C. of the layer (e.g., transfer layer, substrate, other layers) and the pressure-sensitive adhesive layer disposed in contact with the pressure-sensitive adhesive layer is preferably 2 N / 20 mm or more, more preferably 4 N / 20 mm or more, still more preferably 6 N / 20 mm or more, and particularly preferably 8 N / 20 mm or more. The upper limit of the anchoring force is, for example, 30 N/20 mm (preferably 50 N/20 mm). The anchoring force is measured by pulling the pressure-sensitive adhesive layer away from the adjacent layer under conditions of a peeling angle of 180° and a peeling speed (tensile speed) of 300 mm/min under 23°C.

In the pressure-sensitive adhesive sheet, the anchoring force at 23° C. of the layer (e.g., pressure-sensitive adhesive layer, base material, other layer) and the transfer layer disposed in contact with the transfer layer is preferably 2 N/20 mm or more, more preferably 4 N/20 mm or more, still more preferably 6 N/20 mm or more, and particularly preferably 8 N/20 mm or more. The upper limit of the anchoring force is, for example, 30 N/20 mm (preferably 50 N/20 mm). The anchoring force is measured by pulling the transfer layer away from the adjacent layer under conditions of a peeling angle of 180° and a peeling speed (tensile speed) of 300 mm/min under 23°C.

The light transmittance of the pressure-sensitive adhesive sheet of the present invention at a wavelength of 248 nm is preferably 50% or less, more preferably 30% or less, still more preferably 10% or less, and particularly preferably 5% or less. In one embodiment, the light transmittance of the pressure-sensitive adhesive sheet at a wavelength of 248 nm can be controlled by the light transmittance of the pressure-sensitive adhesive layer and/or the substrate. Specifically, the transmittance is controlled by adjusting the components of the pressure-sensitive adhesive layer (e.g., the type of base polymer; the type of additives such as tackifiers and crosslinking agents; their blending amounts, etc.), the thickness of the pressure-sensitive adhesive layer, the constituent material of the base material, and the thickness of the base material. In the present invention, by lowering the light transmittance, generation of deformation of the pressure-sensitive adhesive layer and/or substrate can be promoted, and the laser output at the time of peeling can be lowered. Since the pressure-sensitive adhesive sheet of the present invention develops peelability with low-power laser light, use of the pressure-sensitive adhesive sheet can reduce damage to the adherend during peeling and prevent damage to the adherend. The light transmittance at a wavelength of 248 nm is preferably as low as possible, but the lower limit thereof is, for example, 0.5% (preferably 0%).

The light transmittance of the pressure-sensitive adhesive sheet of the present invention at a wavelength of 365 nm is preferably 50% or more, more preferably 60% or more, still more preferably 70% or more. Within this range, a pressure-sensitive adhesive sheet in which the transfer layer can be preferably cured by irradiation with active energy rays can be obtained. The light transmittance of the adhesive sheet at a wavelength of 365 nm is preferably as high as possible, but the upper limit thereof is, for example, 95% (preferably 100%).

The haze value of the pressure-sensitive adhesive sheet of the present invention is preferably 70% or less, and more preferably 65% or less. Within this range, a pressure-sensitive adhesive sheet in which the transfer layer can be preferably cured by irradiation with active energy rays can be obtained. In one embodiment, the haze value of the pressure-sensitive adhesive sheet is 20% or less. The lower the haze value of the PSA sheet, the better, but the lower limit thereof is, for example, 0.1%.

The thickness of the pressure-sensitive adhesive sheet is preferably 1 μm to 300 μm, more preferably 5 μm to 200 μm. In one embodiment, the thickness of the pressure-sensitive adhesive sheet is 30 μm or less. When the PSA sheet is thin, strain generated in the PSA layer is easily propagated to the transfer layer, and a PSA sheet having excellent peelability can be obtained.

When the pressure-sensitive adhesive sheet further includes a substrate and/or any suitable other layer, the distance between the pressure-sensitive adhesive layer and the transfer layer is preferably less than 50 μm, more preferably less than 30 μm, still more preferably less than 25 μm, and particularly preferably less than 10 μm. Within this range, the strain generated in the pressure-sensitive adhesive layer is easily propagated to the transfer layer, and a pressure-sensitive adhesive sheet having excellent peelability can be obtained.

B. transfer layer

The thickness of the transfer layer is preferably 1 μm to 30 μm, more preferably 2 μm to 20 μm, still more preferably 3 μm to 10 μm. In such a range, the said effect becomes remarkable.

The initial indentation modulus A of the transfer layer at 23°C is preferably 0.1 MPa or more and less than 14 MPa, more preferably 0.1 MPa to 10 MPa, still more preferably 0.2 MPa to 8 MPa. If it is this range, the adhesive sheet excellent in fixation property can be obtained. The indentation modulus can be measured by a single indentation method at 23° C. at an indentation speed of 10 nm/s and an indentation depth of 100 nm. The adhesive strength of the transfer layer changes with active energy ray irradiation and laser light irradiation. In this specification, "initial indentation elastic modulus A" means adhesive strength before active energy ray and laser light irradiation.

The transfer layer is preferably a layer having an indentation modulus B (also referred to as an elastic modulus after curing) of 14 MPa or more at 23° C. after irradiation with ultraviolet rays of 300 mJ/cm ² , It is more preferable that it is a layer with 15 MPa or more, more preferably a layer with 20 MPa or more, and particularly preferably a layer with 50 MPa or more. If it is this range, the adhesive sheet excellent in peelability can be obtained. In addition, contamination of the adherend at the time of peeling can be prevented. The upper limit of the elastic modulus B after curing at 23°C is, for example, 500 MPa (preferably 300 MPa).

After the transfer layer is irradiated with ultraviolet rays of 300 mJ / cm ² , the indentation elastic modulus B at 23 ° C is preferably 20 times or more, more preferably 30 times or more, more preferably 30 times to 1000 times, and particularly preferably 50 times to 200 times the initial indentation elastic modulus A at 23 ° C. of the transfer layer. If it is this range, the adhesive sheet excellent in the balance of the fixation property of a to-be-adhered body and peelability can be obtained.

After the transfer layer is irradiated with ultraviolet rays of 300 mJ / cm ² , the indentation elastic modulus B at 23 ° C is preferably 5 times or more, more preferably 10 times or more, more preferably 50 times to 5000 times, and particularly preferably 100 times to 3000 times the indentation elastic modulus I at 23 ° C of the pressure-sensitive adhesive layer. Within this range, deformation of each layer due to laser light irradiation can be made suitable, and an adhesive sheet having excellent peelability by laser light irradiation can be obtained. Such an adhesive sheet can realize reliable peelability in a narrow range.

In one embodiment, the transfer layer contains an active energy ray-curable pressure-sensitive adhesive. The active energy ray-curable pressure-sensitive adhesive may further contain a ultraviolet absorber and/or a photopolymerization initiator.

(active energy ray curable adhesive)

In one embodiment, as an active energy ray-curable pressure-sensitive adhesive, an active energy ray-curable pressure-sensitive adhesive (A1) containing a base polymer serving as a base material and an active energy ray-reactive compound (monomer or oligomer) capable of bonding with the base polymer is used. In another embodiment, an active energy ray-curable pressure-sensitive adhesive (A2) containing an active energy ray-reactive polymer is used as a base polymer. Preferably, the base polymer has a functional group capable of reacting with the photopolymerization initiator. As this functional group, a hydroxyl group, a carboxyl group, etc. are mentioned, for example.

Examples of the base polymer used in the pressure-sensitive adhesive (A1) include rubber-based polymers such as natural rubber, polyisobutylene rubber, styrene-butadiene rubber, styrene-isoprene-styrene block copolymer rubber, recycled rubber, butyl rubber, polyisobutylene rubber, and nitrile rubber (NBR); silicone-based polymers; An acrylic polymer etc. are mentioned. You may use these polymers individually or in combination of 2 or more types. Among these, acrylic polymers are preferred.

Examples of the acrylic polymer include homopolymers or copolymers of hydrocarbon group-containing (meth)acrylic acid esters such as (meth)acrylic acid alkyl esters, (meth)acrylic acid cycloalkyl esters and (meth)acrylic acid aryl esters; and copolymers of the hydrocarbon group-containing (meth)acrylic acid ester with other copolymerizable monomers. Examples of (meth)acrylic acid alkyl esters include (meth)acrylic acid methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, s-butyl ester, t-butyl ester, pentyl ester, isopentyl ester, hexyl ester, heptyl ester, octyl ester, 2-ethylhexyl ester, isooctyl ester, nonyl ester, decyl ester, isodecyl ester, undecyl ester, dodecyl ester i.e. lauryl ester, tridecyl ester, tetradecyl ester, hexadecyl ester, octadecyl ester and eicosyl ester. Examples of the (meth)acrylic acid cycloalkyl ester include cyclopentyl ester and cyclohexyl ester of (meth)acrylic acid. Examples of the aryl (meth)acrylate include phenyl (meth)acrylate and benzyl (meth)acrylate. The proportion of the structural unit derived from the hydrocarbon group-containing (meth)acrylic acid ester is preferably 40 parts by weight or more, and more preferably 60 parts by weight or more with respect to 100 parts by weight of the base polymer.

Examples of the other copolymerizable monomers include carboxyl group-containing monomers, acid anhydride monomers, hydroxyl group-containing monomers, glycidyl group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, and functional group-containing monomers such as acrylamide and acrylonitrile. Examples of the carboxy group-containing monomer include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. As an acid anhydride monomer, maleic acid anhydride and itaconic acid anhydride are mentioned, for example. Examples of the hydroxy group-containing monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl (meth)acrylate. Examples of the glycidyl group-containing monomer include glycidyl (meth)acrylate and methylglycidyl (meth)acrylate. Examples of the sulfonic acid group-containing monomer include styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidepropanesulfonic acid, sulfopropyl (meth)acrylate, and (meth)acryloyloxynaphthalenesulfonic acid. As a phosphoric acid group containing monomer, 2-hydroxyethyl acryloyl phosphate is mentioned, for example. As acrylamide, N-acryloylmorpholine is mentioned, for example. These may be used individually by 1 type, and may be used in combination of 2 or more type. The content of the structural unit derived from the copolymerizable monomer is preferably 60 parts by weight or less, and more preferably 40 parts by weight or less with respect to 100 parts by weight of the base polymer.

The acrylic polymer may contain structural units derived from polyfunctional monomers in order to form a cross-linked structure in its polymer backbone. As the polyfunctional monomer, for example, hexanedioldi(meth)acrylate, (poly)ethylene glycoldi(meth)acrylate, (poly)propylene glycoldi(meth)acrylate, neopentylglycoldi(meth)acrylate, pentaerythritoldi(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy(meth)acrylate (i.e. , polyglycidyl (meth)acrylate), polyester (meth)acrylate and urethane (meth)acrylate. These may be used individually by 1 type, and may be used in combination of 2 or more type. The content of the structural unit derived from the polyfunctional monomer is preferably 40 parts by weight or less, and more preferably 30 parts by weight or less with respect to 100 parts by weight of the base polymer.

The weight average molecular weight of the acrylic polymer is preferably 100,000 to 3,000,000, more preferably 200,000 to 2,000,000. A weight average molecular weight can be measured by GPC (solvent: THF).

Examples of the active energy ray-reactive compound that can be used for the pressure-sensitive adhesive (A1) include photoreactive monomers or oligomers having functional groups having polymerizable carbon-carbon multiple bonds such as acryloyl, methacryloyl, vinyl, allyl, and acetylene groups. Specific examples of the photoreactive monomer include trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butanedioldi(meth)acrylate, 1,6-hexanedioldi( esterified products of (meth)acrylic acid and polyhydric alcohol, such as meth)acrylate and polyethylene glycol di(meth)acrylate; polyfunctional urethane (meth)acrylate; epoxy (meth)acrylate; Oligo ester (meth)acrylate etc. are mentioned. Further, monomers such as methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate (2-isocyanatoethyl methacrylate), m-isopropenyl-α, and α-dimethylbenzyl isocyanate may be used. Specific examples of the photoreactive oligomer include dimers and pentamers of the above monomers. The molecular weight of the photoreactive oligomer is preferably 100 to 3000.

Examples of the active energy ray-reactive compound include monomers such as epoxidized butadiene, glycidyl methacrylate, acrylamide, and vinylsiloxane; Or you may use the oligomer comprised from the said monomer.

Further, as the active energy ray-reactive compound, a mixture of an organic salt such as an onium salt and a compound having a plurality of heterocycles in the molecule may be used. In the mixture, organic salts are cleaved by irradiation with active energy rays (eg, ultraviolet rays, electron beams) to generate ions, which become initiating species and cause ring-opening reactions of heterocycles to form a three-dimensional network structure. As said organic salt, an iodonium salt, a phosphonium salt, an antimonium salt, a sulfonium salt, a borate salt etc. are mentioned, for example. Examples of the heterocycle in the compound having a plurality of heterocycles in the molecule include oxirane, oxetane, oxolane, thirane, aziridine and the like.

In the pressure-sensitive adhesive (A1), the content of the active energy ray-reactive compound is preferably 0.1 part by weight to 500 parts by weight, more preferably 5 parts by weight to 300 parts by weight, and still more preferably 40 parts by weight to 150 parts by weight, based on 100 parts by weight of the base polymer.

Examples of the active energy ray-responsive polymer (base polymer) contained in the pressure-sensitive adhesive (A2) include polymers having functional groups having carbon-carbon multiple bonds such as acryloyl, methacryloyl, vinyl, allyl, and acetylene groups. Specific examples of the active energy ray reactive polymer include polymers composed of polyfunctional (meth)acrylates; photo cationic polymerization type polymer; cinnamoyl group-containing polymers such as polyvinylcinnamate; diazotized aminonovolak resins; polyacrylamide; etc. can be mentioned.

In one embodiment, an active energy ray-reactive polymer formed by introducing active energy ray polymerizable carbon-carbon multiple bonds into side chains, main chains and/or main chain terminals of the acrylic polymer is used. As a method for introducing a radiation-polymerizable carbon-carbon double bond into an acrylic polymer, for example, a raw material monomer containing a monomer having a predetermined functional group (first functional group) is copolymerized to obtain an acrylic polymer, and then a compound having a radiation-polymerizable carbon-carbon double bond and a predetermined functional group (second functional group) that can be bonded by causing a reaction between the first functional group and a compound having a radiation-polymerizable carbon-carbon double bond are subjected to condensation reaction or addition to the acrylic polymer while maintaining radiation polymerizability of the carbon-carbon double bond. How to react can be mentioned.

Examples of the combination of the first functional group and the second functional group include a carboxy group and an epoxy group, an epoxy group and a carboxy group, a carboxy group and an aziridyl group, an aziridyl group and a carboxy group, a hydroxyl group and an isocyanate group, and an isocyanate group and a hydroxyl group. Among these combinations, a combination of a hydroxyl group and an isocyanate group and a combination of an isocyanate group and a hydroxyl group are preferable from the viewpoint of easiness of tracking the reaction. In addition, since producing a polymer having a highly reactive isocyanate group is a high technical difficulty, from the viewpoint of ease of production or acquisition of an acrylic polymer, the first functional group on the acrylic polymer side is a hydroxy group and the second functional group is an isocyanate group. It is more preferable. In this case, examples of the isocyanate compound having a radiation polymerizable carbon-carbon double bond and a second functionalized isocyanate group include methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate, and m-isopropenyl-α, α-dimethylbenzyl isocyanate. Further, the acrylic polymer having a first functional group preferably includes a structural unit derived from the above hydroxy group-containing monomer, and preferably includes a structural unit derived from an ether compound such as 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, or diethylene glycol monovinyl ether.

The pressure-sensitive adhesive (A2) may further contain the active energy ray-reactive compound (monomer or oligomer).

The active energy ray-curable pressure-sensitive adhesive may include a UV absorber and/or a photopolymerization initiator. Details of the ultraviolet absorber and photopolymerization initiator used are described later.

In one embodiment, the active energy ray-curable pressure-sensitive adhesive may contain a photosensitizer. As a photosensitizer, Kawasaki Kasei Kogyo Co., Ltd. brand name "UVS-581", 9, 10- diethoxy anthracene (for example, Kawasaki Kasei Kogyo Co., Ltd. make, brand name "UVS-1101"), etc. are mentioned. Other examples of the photosensitizer include 9,10-dibutoxyanthracene (for example, manufactured by Kawasaki Chemical Industries, Ltd., trade name "UVS-1331"), 2-isopropylthioxanthone, benzophenone, thioxanthone derivatives, 4,4'-bis (dimethylamino) benzophenone, and the like. As a thioxanthone derivative, ethoxycarbonyl thioxanthone, isopropyl thioxanthone, etc. are mentioned, for example.

The content of the photosensitizer is preferably 0.01 part by weight to 2 parts by weight, more preferably 0.5 part by weight to 2 parts by weight, based on 100 parts by weight of the base polymer.

Preferably, the active energy ray-curable pressure-sensitive adhesive contains a crosslinking agent. Examples of the crosslinking agent include isocyanate crosslinking agents, epoxy crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, melamine crosslinking agents, peroxide crosslinking agents, urea crosslinking agents, metal alkoxide crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents, carbodiimide crosslinking agents, and amine crosslinking agents.

The content of the crosslinking agent is preferably 0.5 parts by weight to 10 parts by weight, more preferably 1 part by weight to 8 parts by weight, based on 100 parts by weight of the base polymer of the pressure-sensitive adhesive.

In one embodiment, an isocyanate-based crosslinking agent is preferably used. An isocyanate-based crosslinking agent is preferable in that it can react with a variety of functional groups. Specific examples of the isocyanate-based crosslinking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate; aromatic isocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate; Isocyanate adducts such as trimethylolpropane/tolylene diisocyanate trimer adduct (trade name “Coronate L”, manufactured by Tosoh Corporation), trimethylolpropane/hexamethylene diisocyanate trimer adduct (trade name “Coronate HL”, manufactured by Tosoh Corporation), and isocyanurate of hexamethylene diisocyanate (trade name “Coronate HX”, manufactured by Tosoh Corporation); etc. can be mentioned. Preferably, a crosslinking agent having three or more isocyanate groups is used.

The active energy ray-curable pressure-sensitive adhesive may further contain any appropriate additives, if necessary. Examples of additives include active energy ray polymerization accelerators, radical scavengers, coupling agents (eg, silane coupling agents), tackifiers, plasticizers (eg, trimellitic acid ester plasticizers, pyromellitic acid ester plasticizers, etc.), pigments, dyes, fillers, anti-aging agents, conductive materials, antistatic agents, light stabilizers, peeling regulators, softeners, surfactants, flame retardants, antioxidants, particles, ultraviolet absorbers, etc. can be heard

(photopolymerization initiator)

As the photopolymerization initiator, any suitable initiator can be used. Examples of the photopolymerization initiator include α-ketol compounds such as 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α′-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, and 1-hydroxycyclohexylphenyl ketone; acetophenone-based compounds such as methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, and 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane-1; benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether; ketal-based compounds such as benzyldimethyl ketal; aromatic sulfonyl chloride-based compounds such as 2-naphthalenesulfonyl chloride; photoactive oxime-based compounds such as 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime; benzophenone compounds such as benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone; thioxanthone-based compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone; camphorquinone; halogenated ketones; acyl phosphine oxide; Acyl phosphonate etc. are mentioned. The usage amount of the photopolymerization initiator can be set to any suitable amount.

In one embodiment, a photopolymerization initiator having a maximum absorption wavelength in the range of 400 nm or less (preferably 380 nm or less, more preferably 340 nm or less) is used.

The usage amount of the photopolymerization initiator may be set to any suitable amount.

As said photoinitiator, you may use a commercial item. For example, as a photopolymerization initiator having a maximum absorption wavelength in the range of 400 nm or less, BASF's trade names "Irgacure 127", "Irgacure 369", "Irgacure 369E", "Irgacure 379", "Irgacure 379EG", "Irgacure 819", "Irgacure TOP", "Irgacure 7" 84”, “Irgacure OXE01” and the like.

C. Adhesive layer

The thickness of the pressure-sensitive adhesive layer is preferably 30 μm or less, more preferably 20 μm or less, still more preferably 10 μm or less. In such a range, the said effect becomes remarkable. The lower limit of the thickness of the pressure-sensitive adhesive layer is, for example, 1 μm (preferably 0.5 μm).

The indentation modulus I at 23°C of the pressure-sensitive adhesive layer is preferably 0.05 MPa to 20 MPa, more preferably 0.08 MPa to 10 MPa, still more preferably 0.08 MPa to 5 MPa. Within this range, deformation of each layer due to laser light irradiation can be made suitable, and an adhesive sheet having excellent peelability by laser light irradiation can be obtained. Such an adhesive sheet can realize reliable peelability in a narrow range.

The light transmittance of the pressure-sensitive adhesive layer at a wavelength of 248 nm is preferably 50% or less, more preferably 30% or less, still more preferably 10% or less, and particularly preferably 5% or less. The light transmittance of the pressure-sensitive adhesive layer at a wavelength of 248 nm is preferably as low as possible, but the lower limit thereof is, for example, 0.5% (preferably 0%).

The light transmittance of the pressure-sensitive adhesive layer at a wavelength of 365 nm is preferably 50% or more, more preferably 60% or more, still more preferably 70% or more. The light transmittance of the pressure-sensitive adhesive layer at a wavelength of 365 nm is preferably higher, but the upper limit thereof is, for example, 95% (preferably 100%).

The haze value of the pressure-sensitive adhesive sheet of the pressure-sensitive adhesive layer is preferably 70% or less, and more preferably 65% or less. In one embodiment, the haze value of the said adhesive layer is 20 % or less. Although the haze value of an adhesive layer is so preferable that it is low, the lower limit is 0.1 %, for example.

The pressure-sensitive adhesive layer contains any suitable pressure-sensitive adhesive. As the pressure-sensitive adhesive, any appropriate pressure-sensitive adhesive may be used as long as the effects of the present invention are obtained. As the pressure-sensitive adhesive, for example, a pressure-sensitive adhesive may be used.

(pressure sensitive adhesive)

Examples of the pressure-sensitive adhesive include acrylic adhesives, rubber-based adhesives, vinylalkyl ether-based adhesives, silicone-based adhesives, polyester-based adhesives, polyamide-based adhesives, urethane-based adhesives, and styrene-diene block copolymer-based adhesives. Among them, acrylic adhesives or rubber-based adhesives are preferred, and acrylic adhesives are more preferred. Moreover, you may use the said adhesive individually or in combination of 2 or more types. In one embodiment, from the viewpoint of UV absorption, an adhesive containing a base polymer having an aromatic ring and/or a double bond is used. Also from this point of view, an acrylic pressure sensitive adhesive can be preferably used.

Examples of the acrylic pressure-sensitive adhesive include acrylic pressure-sensitive adhesives having, as a base polymer, an acrylic polymer (homopolymer or copolymer) using one or two or more (meth)acrylic acid alkyl esters as monomer components. Specific examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (meth)acrylate. Isooctyl acrylate, (meth)nonyl acrylate, (meth)isononyl acrylate, (meth)decyl acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, (meth) and (meth)acrylic acid C1-20 alkyl esters such as nonadecyl acrylate and eicosyl (meth)acrylate. Among them, (meth)acrylic acid alkyl esters having a linear or branched alkyl group having 4 to 18 carbon atoms can be preferably used.

The acrylic polymer may contain units corresponding to other monomeric components copolymerizable with the alkyl (meth)acrylic acid ester, if necessary, for the purpose of modification such as cohesive force, heat resistance, and crosslinkability. Examples of such monomer components include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; acid anhydride monomers such as maleic anhydride and icotanoic acid anhydride; Hydroxyl group-containing monomers such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyhexyl (meth)acrylate, hydroxyoctyl (meth)acrylate, hydroxydecyl (meth)acrylate, hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methylmethacrylate; sulfonic acid group-containing monomers such as styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidepropanesulfonic acid, sulfopropyl (meth)acrylate, and (meth)acryloyloxynaphthalenesulfonic acid; (N-substituted) amide monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, and N-methylol propane(meth)acrylamide; aminoalkyl (meth)acrylate monomers such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate; alkoxyalkyl (meth)acrylate monomers such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate; maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide; itaconimide monomers such as N-methyl itaconimide, N-ethyl itaconimide, N-butyl itaconimide, N-octyl itaconimide, N-2-ethylhexyl itaconimide, N-cyclohexyl itaconimide, and N-lauryl itaconimide; succinimide monomers such as N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, and N-(meth)acryloyl-8-oxyoctamethylenesuccinimide; vinyl monomers such as vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, vinylmorpholine, N-vinylcarboxylic acid amides, styrene, α-methylstyrene, and N-vinylcaprolactam; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth)acrylate; glycol-based acrylic ester monomers such as polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate; acrylic acid ester monomers having heterocycles such as (meth)acrylate tetrahydrofurfuryl, fluorine (meth)acrylate, and silicon (meth)acrylate, halogen atoms, silicon atoms, and the like; Hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy acrylate, polyester acrylate, urethane acrylate, etc. mer; olefinic monomers such as isoprene, butadiene, and isobutylene; Vinyl ether type monomers, such as vinyl ether, etc. are mentioned. You may use these monomer components individually or in combination of 2 or more types.

Examples of the rubber-based adhesive include natural rubber; Polyisoprene rubber, styrene-butadiene (SB) rubber, styrene-isoprene (SI) rubber, styrene-isoprene-styrene block copolymer (SIS) rubber, styrene-butadiene-styrene block copolymer (SBS) rubber, styrene-ethylene-butylene-styrene block copolymer (SEBS) rubber, styrene-ethylene-propylene-styrene block copolymer (SEPS) rubber, styrene-ethylene-propylene block copolymer (SEP) Synthetic rubbers such as rubber, recycled rubber, butyl rubber, polyisobutylene, and modified products thereof; The rubber type adhesive which uses etc. as a base polymer is mentioned.

The pressure-sensitive adhesive may contain any suitable additive, if necessary. Examples of the additives include crosslinking agents, tackifiers (eg, rosin-based tackifiers, terpene-based tackifiers, hydrocarbon-based tackifiers, etc.), plasticizers (eg, trimellitic acid ester plasticizers, pyromellitic acid ester plasticizers), pigments, dyes, anti-aging agents, conductive materials, antistatic agents, light stabilizers, peeling regulators, softeners, surfactants, flame retardants, antioxidants, ultraviolet absorbers, Particles etc. are mentioned.

Examples of the crosslinking agent include isocyanate crosslinking agents, epoxy crosslinking agents, melamine crosslinking agents, peroxide crosslinking agents, urea crosslinking agents, metal alkoxide crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, and amine crosslinking agents. Among them, an isocyanate-based crosslinking agent or an epoxy-based crosslinking agent is preferred. In one embodiment, a crosslinking agent having an aromatic ring and/or a double bond (for example, an aromatic isocyanate-based crosslinking agent) is used from the viewpoint of UV absorption.

Specific examples of the isocyanate-based crosslinking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate; aromatic isocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate; Isocyanate adducts such as trimethylolpropane/tolylene diisocyanate trimer adduct (trade name “Coronate L”, manufactured by Tosoh Corporation), trimethylolpropane/hexamethylene diisocyanate trimer adduct (trade name “Coronate HL”, manufactured by Tosoh Corporation), and isocyanurate of hexamethylene diisocyanate (trade name “Coronate HX”, manufactured by Tosoh Corporation); etc. can be mentioned. The content of the isocyanate-based crosslinking agent can be set to any suitable amount depending on the desired adhesive force, and is typically 0.1 part by weight to 20 parts by weight, more preferably 0.5 part by weight to 10 parts by weight based on 100 parts by weight of the base polymer. It is 10 parts by weight.

Examples of the epoxy-based crosslinking agent include N,N,N',N'-tetraglycidyl-m-xylenediamine, diglycidylaniline, 1,3-bis(N,N-glycidylaminomethyl) cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name "Tetrade C"), 1,6-hexanediol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Epol Light 1600"), neopentyl glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Epolite 1500NP"), ethylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Epolite 40E"), propylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Corporation, trade name "Epolite 70P"), polyethylene glycol digly Cidyl ether (manufactured by Nippon Yushi Co., Ltd., trade name "Epiol E-400"), polypropylene glycol diglycidyl ether (manufactured by Nippon Yushi Co., Ltd., trade name "Epiol P-200"), sorbitol polyglycidyl ether (manufactured by Nagase ChemteX Co., Ltd., trade name "Denacol EX-611"), glycerol polyglycidyl ether (manufactured by Nagase Chemtex Corporation, trade name "Denacol EX-314"), Pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether (manufactured by Nagase ChemteX Co., Ltd., trade name "Denacol EX-512"), sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris (2-hydroxyethyl) isocyanurate, resorcin diglycidyl ether, bisphenol -S-diglycidyl ether, an epoxy resin having two or more epoxy groups in the molecule, and the like. The content of the epoxy-based crosslinking agent can be set to any appropriate amount depending on the desired adhesive strength, and is typically 0.01 part by weight to 10 parts by weight, more preferably 0.03 part by weight to 5 parts by weight, based on 100 parts by weight of the base polymer.

As the adhesive subsidiary, for example, rosin resin (eg, rosin ester resin, etc.), terpene -based resin (eg, terpenphenols (terpene degeneration resin), hydrogen additive terpen resin, etc.) Hydrocarbon -based petroleum resins such as petroleum resin and aromatic petroleum resin) and phenolic resin are mentioned. In one embodiment, a crosslinking agent (for example, a rosin-based resin) having an aromatic ring and/or a double bond is used from the viewpoint of ultraviolet absorption. The content of the tackifier can be set to any suitable amount depending on the desired adhesive strength, and is typically 1 part by weight to 50 parts by weight, more preferably 10 parts by weight to 30 parts by weight, based on 100 parts by weight of the base polymer.

D. Description

The substrate may be made of any suitable resin. Examples of the resin include polyolefin resins such as polyethylene resins, polypropylene resins, polybutene resins, and polymethylpentene resins, polyurethane resins, polyester resins, polyimide resins, polyether ketone resins, polystyrene resins, polyvinyl chloride resins, polyvinylidene chloride resins, fluorine resins, silicone resins, cellulose resins, and ionomer resins. Among them, polyolefin-based resins are preferred.

In one embodiment, the substrate is composed of at least one selected from the group consisting of polyethylene terephthalate-based resins, polyimide-based resins, polystyrene-based resins, and polycarbonate-based resins. A base material composed of these resins is advantageous in that the light transmittance at a wavelength of 248 nm is low.

The thickness of the substrate is preferably 2 μm to 300 μm, more preferably 2 μm to 100 μm, still more preferably 2 μm to 50 μm. In one embodiment, the substrate has a thickness of less than 50 μm, more preferably 30 μm or less, still more preferably 20 μm or less, particularly preferably 10 μm or less, and most preferably 5 μm or less. By reducing the thickness of the base material, the strain generated in the pressure-sensitive adhesive layer is easily propagated to the transfer layer, and a pressure-sensitive adhesive sheet having excellent peelability can be obtained.

The indentation modulus of the substrate at 23°C is preferably 5000 MPa or less, more preferably 3000 MPa or less, still more preferably 1000 MPa or less. If it is within this range, it is possible to make a base material that does not easily absorb the strain generated in the pressure-sensitive adhesive layer and easily propagates the strain to the transfer layer. The lower limit of the indentation modulus of the base material at 23°C is preferably 1 MPa, more preferably 5 MPa, still more preferably 10 MPa. Within this range, an adhesive sheet having appropriate rigidity and excellent handling properties can be obtained.

The total light transmittance of the substrate is preferably 70% or more, more preferably 80% or more, still more preferably 90% or more, and particularly preferably 95% or more. The upper limit of the total light transmittance of the substrate is, for example, 98% (preferably 99%).

E. Manufacturing method of adhesive sheet

The pressure-sensitive adhesive sheet may be manufactured by any suitable method. The pressure-sensitive adhesive sheet can be obtained, for example, by applying the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer and the transfer layer onto a substrate or a release liner, respectively. As the coating method, various methods such as bar coater coating, air knife coating, gravure coating, gravure reverse coating, reverse roll coating, lip coating, die coating, dip coating, offset printing, flexographic printing, and screen printing can be employed. Alternatively, the pressure-sensitive adhesive sheet may be formed by forming a pressure-sensitive adhesive layer on a release liner, forming a transfer layer on another release liner, bonding them together, or bonding them to a base material.

F. How to use the adhesive sheet

The pressure-sensitive adhesive sheet of the present invention can be used when processing and/or transporting any suitable member to be processed (e.g., an electronic component) and temporarily fixing the member to be processed. A method of using the PSA sheet of the present invention includes, for example, (i) bonding the PSA layer to a support, (ii) bonding and fixing a member to be processed to the transfer layer of the PSA sheet, (ii) processing or transferring the member to be processed, (iii) irradiating the PSA sheet with active energy rays (eg, ultraviolet rays) to reduce the adhesive force on the transfer layer side of the PSA sheet, (iv) irradiating a laser beam to a portion where peelability is desired, It is possible to use a method by causing deformation to occur. According to the method, it becomes possible to peel the member to be processed by natural fall. Further, when a plurality of workpiece members are temporarily fixed, it is also possible to peel only a part of them. Since the use of the PSA sheet of the present invention can reduce the adhesive force to the extent that it naturally falls, even a very small (e.g., 50 µm square) member to be processed can be separated from each other.

As a support body in said (i), a glass plate is used, for example. The support is preferably light-transmitting. The total light transmittance of the support is, for example, 50% or more, preferably 80% or more.

In one embodiment, the active energy rays in (iii) above are irradiated from the pressure-sensitive adhesive layer side (substantially, the support body side) of the pressure-sensitive adhesive sheet.

In one embodiment, the laser beam in (iv) above is irradiated from the pressure-sensitive adhesive layer side (substantially, the support body side) of the pressure-sensitive adhesive sheet.

In one embodiment, the wavelength of the laser light is 200 nm to 300 nm.

Example

Hereinafter, the present invention will be specifically described by examples, but the present invention is not limited by these examples. Tests and evaluation methods in Examples are as follows. In addition, "part" and "%" are based on weight unless otherwise specified.

(1) Adhesion to glass of the pressure-sensitive adhesive layer I

The PET separator on the transfer layer side of the adhesive sheet was peeled off, and PET (Lumiror S10, manufactured by Toray) having a thickness of 25 μm was bonded. After that, the PET separator on the other side was peeled off, and a 2 kg roller was bonded to a glass plate (manufactured by Matsunami Glass Kogyo Co., Ltd., trade name "S200423") by one reciprocation, and the adhesive strength was measured by a method according to JIS Z 0237: 2000 (peeling angle 180 °, peeling rate (tensile speed) 300 mm / min, measurement temperature: 23 ° C.).

(2) Adhesion of the transfer layer to the stainless plate

The PET separator on the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive sheet (in Comparative Example 2, one PET separator adhered to the transfer layer) was peeled off, and a 25 μm-thick PET (Lumiror S10 manufactured by Toray) was bonded. After that, the PET separator on the other side was peeled off, a 2 kg roller was bonded to SUS304 by one reciprocation, and the adhesive force was measured by a method according to JIS Z 0237: 2000 (peeling angle 180 °, peeling speed (tensile speed) 300 mm / min, measurement temperature: 23 ° C.), and the initial adhesive force was referred to as A.

In the same way, after bonding the adhesive sheet to SUS304, the entire surface was irradiated with ultraviolet rays (specific wavelength: 365 nm, integrated light amount: 300 mJ/cm ² ) of a high-pressure mercury lamp using an ultraviolet irradiation device (manufactured by Nitto Seiki, trade name “UM-810”) from the adhesive layer side, and then the adhesive force was similarly measured and referred to as adhesive force B after curing.

(3) Indentation modulus (before curing)

The indentation modulus of the pressure-sensitive adhesive layer and the transfer layer was measured using a Tripoint Indenter TI-950 manufactured by Hysitron. The measurement was performed at an indentation speed of 10 nm/s and an indentation depth of 100 nm by a single indentation method at 23°C.

(4) Indentation modulus (after hardening)

The PET separator on the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive sheet (in Comparative Example 2, one PET separator adhered to the transfer layer) was peeled off and bonded to a large slide glass (manufactured by Matsunami Glass, trade name "S9111") using a hand roller. The entire surface was irradiated with ultraviolet rays (specific wavelength: 365 nm, integrated light amount: 300 mJ/cm ² ) of a high-pressure mercury lamp using an ultraviolet irradiation device (manufactured by Nitto Seiki, trade name “UM-810”) from the slide glass surface side of the obtained sample. Thereafter, the other PET separator was peeled off to expose the transfer layer, and the indentation modulus was measured using a Tripoint Indenter TI-950 manufactured by Hysitron. The measurement was performed at an indentation speed of 10 nm/s and an indentation depth of 100 nm by a single indentation method at 23°C.

(5) Haze value

The haze value of the adhesive sheet was measured using a haze meter (trade name "HAZE METER HM-150", manufactured by Murakami Shikisai Kijutsu Genkyujo).

(6) light transmittance

The light transmittance at a wavelength of 365 nm and the light transmittance at 248 nm of the adhesive sheet were measured using a spectrophotometer (trade name "Spectrophotometer U-4100", manufactured by Hitachi High-Tech Sciences).

(7) peelability (transferability)

The PET separator on the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive sheet (in Comparative Example 2, one PET separator adhered to the transfer layer) was peeled off and bonded to a quartz plate (manufactured by As One Co., Ltd.) using a hand roller. Thereafter, the PET separator on the other side was peeled off, and a silicon chip of 125 μm × 100 μm was bonded to the adhesive side of the transfer layer.

The entire surface was irradiated with ultraviolet rays (specific wavelength: 365 nm, integrated light amount: 300 mJ/cm ² ) of a high-pressure mercury lamp using an ultraviolet irradiation device (manufactured by Nitto Seiki, trade name "UM-810") from the side of the quartz plate.

Thereafter, laser light having a wavelength of 248 nm (irradiation area: 130 μm × 105 μm, output 100 mJ / cm ² ) was irradiated only on the target member position from the quartz plate side (1 plus per chip), and the case where it fell naturally was rated as pass (○), and the case where it did not fall naturally was rated as fail (×).

(8) Presence or absence of deformation

The surface deformation of the transfer layer after laser irradiation was observed under a microscope. A case in which significant color difference was observed between the laser irradiation site and other locations was rated as fail (X), and a case where it was not was rated as pass (○).

In addition, a micrograph of the surface of the transfer layer in Example 1 (evaluation of deformation: pass) is shown in FIG. 2 (a), and a micrograph of the surface of the transfer layer in Comparative Example 1 (evaluation of deformation: fail) is shown in FIG.

(9) adhesive residue

The glass plate after evaluation of said "(1) adhesive force with respect to the glass of an adhesive layer" was visually observed. The case where the pressure-sensitive adhesive layer remained on the glass was rated as disqualified (X), and the case where it was not was evaluated as pass (○).

[Production Example 1] Adjustment of Acrylic Polymer I

A monomer composition was prepared by mixing 30 parts by weight of 2-ethylhexyl acrylate, 70 parts by weight of butyl acrylate, 3 parts by weight of acrylic acid, and 1 part by weight of 4-hydroxybutyl acrylate.

Subsequently, nitrogen was introduced into a reaction vessel equipped with a nitrogen inlet pipe, a thermometer, and a stirrer, and under a nitrogen atmosphere, 103.1 parts by weight of the monomer composition, 0.2 parts by weight of benzoyl peroxide (BPO), and 150 parts by weight of toluene were added, and stirred at 60 ° C. for 6 hours to obtain an acrylic polymer solution I containing acrylic polymer I.

[Production Example 2] Adjustment of Acrylic Polymer II

A monomer composition was prepared by mixing 70 parts by weight of ethyl acrylate, 30 parts by weight of 2-hydroxyethyl acrylate, 5 parts by weight of methyl methacrylate, and 4 parts by weight of hydroxyethyl acrylate.

Next, nitrogen was introduced into a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirrer, and 295 parts by weight of toluene, 109 parts by weight of the monomer composition, and 0.2 parts by weight of benzoyl peroxide (BPO) were introduced under a nitrogen atmosphere, and stirred at 60 ° C. for 4 hours to obtain an acrylic polymer solution II containing acrylic polymer II having a weight average molecular weight of 500,000.

[Production Example 3] Adjustment of Acrylic Polymer III

A monomer composition was prepared by mixing 100 parts by weight of 2-ethylhexyl acrylate, 2 parts by weight of acrylic acid, and 0.01 part by weight of trimethylolpropane triacrylate.

Next, nitrogen was introduced into a reaction vessel equipped with a nitrogen inlet pipe, a thermometer, and a stirrer, and under a nitrogen atmosphere, 102.01 parts by weight of the monomer composition, 0.2 parts by weight of benzoyl peroxide (BPO), and 189 parts by weight of toluene were added and stirred at 60 ° C. for 7 hours to obtain an acrylic polymer solution III containing acrylic polymer III.

[Production Example 4] Adjustment of Acrylic Polymer IV

A monomer composition was prepared by mixing 100 parts by weight of butyl acrylate, 78 parts by weight of ethyl acrylate, and 40 parts by weight of hydroxyethyl acrylate.

Subsequently, nitrogen was introduced into a reaction vessel equipped with a nitrogen inlet pipe, a thermometer, and a stirrer, and 507 parts by weight of toluene, 218 parts by weight of the monomer composition, and 1.2 parts by weight of benzoyl peroxide (BPO) were introduced under a nitrogen atmosphere, and stirred at 60 ° C. for 5 hours. Then, it was cooled to room temperature, 42.6 parts by weight of 2-methacryloyloxyethyl isocyanate was added and reacted, an NCO group was added to the terminal OH group of the side chain of 2-hydroxyethyl acrylate in the copolymer, and an acrylic polymer solution IV containing acrylic polymer IV having a carbon-carbon double bond at the terminal was obtained.

[Production Example 5] Adjustment of Acrylic Polymer V

A monomer composition was prepared by mixing 100 parts by weight of 2-ethylhexyl acrylate, 25.5 parts by weight of acryloylmorpholine, and 18.5 parts by weight of hydroxyethyl acrylate.

Subsequently, nitrogen was introduced into a reaction vessel equipped with a nitrogen inlet pipe, a thermometer, and a stirrer, and 60 parts by weight of toluene, 144 parts by weight of the monomer composition, and 0.3 parts by weight of benzoyl peroxide (BPO) were introduced under a nitrogen atmosphere, and stirred at 60 ° C. for 4 hours. Then, it was cooled to room temperature, 12 parts by weight of 2-methacryloyloxyethyl isocyanate was added and reacted, an NCO group was added to the terminal OH group of the side chain of 2-hydroxyethyl acrylate in the copolymer, and the acrylic polymer solution V containing the acrylic polymer V having a carbon-carbon double bond at the terminal was obtained.

[Production Example 6] Adjustment of Acrylic Polymer VI

A monomer composition was prepared by mixing 100 parts by weight of 2-methoxyethyl acrylate, 27 parts by weight of acryloylmorpholine, and 22 parts by weight of 2-hydroxyethyl acrylate.

Subsequently, nitrogen was introduced into a reaction vessel equipped with a nitrogen inlet pipe, a thermometer, and a stirrer, and 500 parts by weight of toluene, 149 parts by weight of the monomer composition, and 0.3 parts by weight of benzoyl peroxide (BPO) were introduced under a nitrogen atmosphere, and stirred at 60 ° C. for 5 hours. Then, it was cooled to room temperature, 24 parts by weight of 2-methacryloyloxyethyl isocyanate was added and reacted, an NCO group was added to the terminal OH group of the side chain of 2-hydroxyethyl acrylate in the copolymer, and an acrylic polymer solution VI containing acrylic polymer VI having a carbon-carbon double bond at the terminal was obtained.

[Example 1]

(Preparation of adhesive)

To the acrylic polymer solution I containing 100 parts by weight of the acrylic polymer I, 2 parts by weight of a crosslinking agent (manufactured by Tosoh Corporation, trade name “Coronate L”) and 30 parts by weight of a tackifying resin (manufactured by Arakawa Chemical Industry, trade name “D-125”) were added to obtain an adhesive (1) for forming an adhesive layer.

To acrylic polymer solution IV containing 100 parts by weight of acrylic polymer IV, 3 parts by weight of a crosslinking agent (manufactured by Tosoh Corporation, trade name “Coronate L”) and 10 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name “Irgacure 127”) were added to obtain an adhesive (A) for forming a transfer layer.

(adhesive sheet)

The adhesive (1) was applied to the silicone-treated surface of a PET separator (thickness: 38 μm) and then heated at 120° C. for 2 minutes to form an adhesive layer having a thickness of 4 μm.

Separately, the adhesive (A) was applied to the siliconized surface of a PET separator (thickness: 75 μm) and then heated at 120° C. for 2 minutes to form a transfer layer having a thickness of 5 μm.

An adhesive layer with a PET separator was bonded to one side of a PET substrate (manufactured by Toray, trade name: “Lumiror 2DC61”, thickness: 2 μm), and a transfer layer with a PET separator was bonded to the other side to obtain an adhesive sheet composed of PET separator/adhesive layer/substrate/transfer layer/PET separator.

The obtained PSA sheet was subjected to the above evaluation. The results are shown in Table 1.

[Example 2]

An adhesive sheet was obtained in the same manner as in Example 1, except that the acrylic polymer solution V containing 100 parts by weight of the acrylic polymer V was used instead of the acrylic polymer solution IV. The obtained PSA sheet was subjected to the above evaluation. The results are shown in Table 1.

[Example 3]

To acrylic polymer solution VI containing 100 parts by weight of acrylic polymer VI, 5 parts by weight of a crosslinking agent (manufactured by Tosoh Corporation, trade name “Coronate L”) and 10 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name “Irgacure 127”) were added to obtain an adhesive (C) for forming a transfer layer.

An adhesive sheet was obtained in the same manner as in Example 1 except that the transfer layer was formed using the adhesive (C) instead of the adhesive (A). The obtained PSA sheet was subjected to the above evaluation. The results are shown in Table 1.

[Example 4]

To acrylic polymer solution VI containing 100 parts by weight of acrylic polymer VI, 5 parts by weight of a crosslinking agent (manufactured by Tosoh Corporation, trade name “Coronate L”), 10 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name “Irgacure 127”), 5 parts by weight of silica fine particles (manufactured by Admatechs, trade name “YA050C”) were added to obtain an adhesive (D) for forming a transfer layer.

An adhesive sheet was obtained in the same manner as in Example 1, except that the transfer layer was formed using the adhesive (D) instead of the adhesive (A). The obtained PSA sheet was subjected to the above evaluation. The results are shown in Table 1.

[Example 5]

A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 3 except that the thickness of the pressure-sensitive adhesive layer was 20 µm. The obtained PSA sheet was subjected to the above evaluation. The results are shown in Table 1.

[Example 6]

(Preparation of adhesive)

It carried out similarly to Example 1, and obtained the adhesive (1) for adhesive layer formation.

In the acrylic polymer solution VI containing 100 parts by weight of the acrylic polymer VI, 5 parts by weight of cross -derivative (wholesale priests, the product name "Coronate L"), the photocurrent initiator (BASF Priest, the product name "Irga Cure 127") 10 parts by weight, ultraviolet absorbent (BASF priest, product name "Tinuvin 405”, molecular weight : 583.8) 5 parts by weight was added to obtain an adhesive (E) for the formation of a warrior layer.

(adhesive sheet)

The adhesive (1) was applied to the silicone-treated surface of a PET separator (thickness: 38 μm) and then heated at 120° C. for 2 minutes to form an adhesive layer having a thickness of 4 μm.

Separately, the adhesive (E) was applied to the silicone-treated surface of a PET separator (thickness: 75 μm), and then heated at 120° C. for 2 minutes to form a transfer layer having a thickness of 5 μm.

An adhesive layer with a PET separator was bonded to one side of a PET substrate (manufactured by Toray, trade name “Lumiror S10”, thickness: 25 μm), and a transfer layer with a PET separator was bonded to the other side to obtain an adhesive sheet composed of PET separator/adhesive layer/substrate/transfer layer/PET separator.

The obtained PSA sheet was subjected to the above evaluation. The results are shown in Table 1.

[Example 7]

An adhesive sheet was obtained in the same manner as in Example 3 except that the thickness of the transfer layer was 25 μm. The obtained PSA sheet was subjected to the above evaluation. The results are shown in Table 1.

[Example 8]

(Preparation of adhesive)

8.5 parts by weight of a crosslinking agent (manufactured by Tosoh Corporation, trade name "Coronate L") was added to acrylic polymer solution II containing 100 parts by weight of acrylic polymer II to obtain an adhesive (2) for forming an adhesive layer.

In the same manner as in Example 3, an adhesive (C) for forming a transfer layer was obtained.

(adhesive sheet)

The adhesive (2) was applied to the siliconized surface of a PET separator (thickness: 38 μm) and then heated at 120° C. for 2 minutes to form an adhesive layer having a thickness of 4 μm.

Separately, the adhesive (C) was applied to the silicone treated surface of a PET separator (thickness: 75 μm), and then heated at 120° C. for 2 minutes to form a transfer layer having a thickness of 5 μm.

An adhesive layer with a PET separator was bonded to one side of a PET substrate (manufactured by Toray, trade name: “Lumiror 2DC61”, thickness: 2 μm), and a transfer layer with a PET separator was bonded to the other side to obtain an adhesive sheet composed of PET separator/adhesive layer/substrate/transfer layer/PET separator.

The obtained PSA sheet was subjected to the above evaluation. The results are shown in Table 1.

[Comparative Example 1]

(Preparation of adhesive)

To acrylic polymer solution III containing 100 parts by weight of acrylic polymer III, 2 parts by weight of a crosslinking agent (trade name "Coronate L" manufactured by Tosoh Corporation) was added to obtain an adhesive (3) for forming an adhesive layer.

In the same manner as in Example 3, an adhesive (C) for forming a transfer layer was obtained.

(adhesive sheet)

The adhesive (3) was applied to the silicone-treated surface of a PET separator (thickness: 38 μm) and then heated at 120° C. for 2 minutes to form an adhesive layer having a thickness of 4 μm.

Separately, the adhesive (C) was applied to the silicone treated surface of a PET separator (thickness: 75 μm), and then heated at 120° C. for 2 minutes to form a transfer layer having a thickness of 5 μm.

An adhesive layer with a PET separator was bonded to one side of a PET substrate (manufactured by Toray, trade name: “Lumiror 2DC61”, thickness: 2 μm), and a transfer layer with a PET separator was bonded to the other side to obtain an adhesive sheet composed of PET separator/adhesive layer/substrate/transfer layer/PET separator.

The obtained PSA sheet was subjected to the above evaluation. The results are shown in Table 1.

[Comparative Example 2]

(Preparation of adhesive)

In the same manner as in Example 3, an adhesive (C) for forming a transfer layer was obtained.

(adhesive sheet)

The adhesive (C) was applied to the silicone treated surface of a PET separator (thickness: 75 μm), and then heated at 120° C. for 2 minutes to form a transfer layer having a thickness of 5 μm.

Another PET separator (thickness: 38 μm) was laminated on the transfer layer to obtain a pressure-sensitive adhesive sheet composed of PET separator/transfer layer/PET separator.

[Comparative Example 3]

To acrylic polymer solution I containing 100 parts by weight of acrylic polymer I, 2 parts by weight of a crosslinking agent (manufactured by Tosoh Corporation, trade name “Coronate L”) and 30 parts by weight of a tackifying resin (manufactured by Arakawa Chemical Industry, trade name “D-125”) were added to obtain an adhesive (F) for forming a transfer layer.

An adhesive sheet was obtained in the same manner as in Example 1, except that the transfer layer was formed using the adhesive (F) instead of the adhesive (A). The obtained PSA sheet was subjected to the above evaluation. The results are shown in Table 1.

[Comparative Example 4]

To the acrylic polymer solution V containing 100 parts by weight of the acrylic polymer V, 3 parts by weight of a crosslinking agent (manufactured by Tosoh Corporation, trade name “Coronate L”), and 0.5 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name “Irgacure 127”) were added to obtain an adhesive (G) for forming a transfer layer.

An adhesive sheet was obtained in the same manner as in Example 8, except that the transfer layer was formed using the adhesive (G) instead of the adhesive (C). The obtained PSA sheet was subjected to the above evaluation. The results are shown in Table 1.

[Comparative Example 5]

(Preparation of adhesive)

It carried out similarly to Example 1, and obtained the adhesive (1) for adhesive layer formation.

In the same manner as in Comparative Example 3, an adhesive (F) for forming a transfer layer was obtained.

(adhesive sheet)

The adhesive (1) was applied to the silicone-treated surface of a PET separator (thickness: 38 μm) and then heated at 120° C. for 2 minutes to form an adhesive layer having a thickness of 4 μm.

Separately, the adhesive (F) was applied to the siliconized surface of a PET separator (thickness: 75 μm) and then heated at 120° C. for 2 minutes to form a transfer layer having a thickness of 5 μm.

An adhesive layer with a PET separator was bonded to one side of a PET base material (manufactured by Toray, trade name “Lumiror S27”, thickness: 75 μm), and a transfer layer with a PET separator was bonded to the other side to obtain a pressure-sensitive adhesive sheet composed of PET separator/adhesive layer/substrate/transfer layer/PET separator.

The obtained PSA sheet was subjected to the above evaluation. The results are shown in Table 1.

[Comparative Example 6]

An adhesive sheet was obtained in the same manner as in Comparative Example 5, except that a PP substrate (manufactured by Toray, trade name: "Trepan BO 12D-KW37", thickness: 12 µm) was used instead of the PET substrate (manufactured by Toray, trade name "Lumiror S27", thickness: 75 µm).

The obtained PSA sheet was subjected to the above evaluation. The results are shown in Table 1.

10: adhesive layer
20: transfer layer
30: substrate
100, 200: adhesive sheet

Claims (5)

A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer and a transfer layer disposed on one side of the pressure-sensitive adhesive layer,
The transfer layer is a layer that is cured by irradiation with active energy rays,
The adhesive force I at 23°C when the PSA layer of the PSA sheet is adhered to the glass plate is 2 N/20 mm or more,
The ratio of the adhesive force I at 23 ° C when the PSA layer of the PSA sheet is adhered to the glass plate to the adhesive force B at 23 ° C after irradiating the transfer layer with 300 mJ / cm ² ultraviolet rays is 5 or more,
adhesive sheet. According to claim 1,
The pressure-sensitive adhesive sheet further comprising a substrate between the pressure-sensitive adhesive layer and the transfer layer. According to claim 1 or 2,
The pressure-sensitive adhesive sheet, wherein after being irradiated with ultraviolet rays of 300 mJ/cm ² , the transfer layer has an indentation modulus B at 23°C that is 5 times or more than the indentation modulus I at 23°C of the PSA layer. According to any one of claims 1 to 3,
The transfer layer contains an active energy ray-curable pressure-sensitive adhesive,
The active energy ray-curable pressure-sensitive adhesive contains an acrylic polymer as a base polymer,
adhesive sheet. According to any one of claims 1 to 4,
A pressure-sensitive adhesive sheet used for temporarily fixing a member to a support body using the pressure-sensitive adhesive sheet and peeling the member from the support body by laser light irradiation after transport and/or processing.