WO2023100401A1

WO2023100401A1 - Adhesive sheet

Info

Publication number: WO2023100401A1
Application number: PCT/JP2022/025049
Authority: WO
Inventors: 克矩伊藤; みずほ千葉
Original assignee: 日東電工株式会社
Priority date: 2021-12-03
Filing date: 2022-06-23
Publication date: 2023-06-08
Also published as: JP2023082842A; TW202338039A

Abstract

Provided is an adhesive sheet capable of temporarily fixing an adherend in a detachable manner, wherein the adhesive sheet exhibits peelability with respect to low-power laser light, eliminates the need for a step for rinsing an adherend after detachment, and which is configured so that a site at which detachment is exhibited is narrow.　This adhesive sheet comprises an adhesive layer, a base, and a transfer layer, in that order. The adhesive layer contains a silicone adhesive. In one embodiment, the light transmittance of the adhesive layer at a wavelength of 248 nm is preferably 25% or more. In one embodiment, the light transmittance of the base at a wavelength of 248 nm is 60% or less.

Description

Adhesive sheet

The present invention relates to an adhesive sheet.

When processing various members represented by electronic components, it is common practice to temporarily fix the member to a support using an adhesive sheet, and peel off the processed member from the support after transfer, processing, etc. ing. For example, in Patent Document 1, a substrate (member to be processed) is processed in a state temporarily fixed to a support via an adhesive layer and a separation layer, and after processing, the separation layer is destroyed by laser light irradiation, and adhesion is performed. A method is described in which the substrate is peeled from the support together with the adhesive layer, and then 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, which poses a problem in terms of production cost. Moreover, there is also a problem that the member is damaged when the laser beam is irradiated with a high output.

Further, in Patent Document 2, a plurality of workpieces are temporarily fixed to a carrier via an adhesive layer, and a laser beam is focused on the adhesive layer to generate blisters, thereby partially fixing the workpieces. A method for optionally separating and transferring from the carrier is described. However, this method has the problem that the blisters generated after laser irradiation spread over time, resulting in peeling of the carrier and unnecessary dropping of the workpiece that does not require transfer.

Patent No. 5875850 Patent No. 6053756

The present invention has been made to solve the above-mentioned conventional problems, and its object is to provide a pressure-sensitive adhesive sheet that can temporarily fix an adherend in a releasable manner, and is releasable with a low-power laser beam. To provide a pressure-sensitive adhesive sheet in which the peeling is exhibited in a narrow range, without the need for a step of washing the adherend after peeling.

The pressure-sensitive adhesive sheet of the present invention comprises a pressure-sensitive adhesive layer, a substrate, and a transfer layer in this order, and the pressure-sensitive adhesive layer contains a silicone-based pressure-sensitive adhesive.
In one embodiment, the pressure-sensitive adhesive layer has a light transmittance of 25% or more at a wavelength of 248 nm.
In one embodiment, the base material has a light transmittance of 60% or less at a wavelength of 248 nm.
In one embodiment, the substrate is composed of a polyester-based resin and/or a polyimide-based resin.
In one embodiment, the base material has a thickness of 50 μm or less.
In one embodiment, the transfer layer is a layer that is cured by irradiation with active energy rays.
In one embodiment, the transfer layer has a thickness of 50 μm or less.
In one embodiment, the adhesive force I at 23° C. when the adhesive layer of the adhesive sheet is adhered to a glass plate is 2 N/20 mm or more.
In one embodiment, the adhesive strength I at 23° C. when the adhesive layer of the adhesive sheet is attached to a glass plate is measured at 23° C. after irradiating the transfer layer with ultraviolet rays of 300 mJ/cm ² . The ratio to the adhesive strength B is 5 or more.
In one embodiment, the indentation elastic modulus B of the transfer layer at 23°C is five times or more the indentation elastic modulus I of the pressure-sensitive adhesive layer at 23°C after irradiation with ultraviolet rays of 300 mJ/cm ² .
In one embodiment, the pressure-sensitive adhesive sheet is used to temporarily fix a member to a support, and after transfer and/or processing, the member is peeled off from the support by laser light irradiation.
In one embodiment, the member is a semiconductor wafer, optical semiconductor element, miniLED or microLED.

According to the present invention, there is provided a pressure-sensitive adhesive sheet capable of releasably temporarily fixing an adherend, exhibiting releasability with a low-power laser beam, and eliminating the need for a step of washing the adherend after peeling, and , it is possible to provide a pressure-sensitive adhesive sheet in which peeling occurs in a narrow range.

1 is a schematic cross-sectional view of an adhesive sheet according to one embodiment of the present invention; FIG.

A. Outline of Adhesive Sheet FIG. 1 is a schematic cross-sectional view of an adhesive sheet according to one embodiment of the present invention. The adhesive sheet 100 according to this embodiment comprises an adhesive layer 10, a substrate 20, and a transfer layer 30. As shown in FIG. The adhesive layer 10 contains a silicone-based adhesive. 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 the transfer layer for the purpose of protecting the pressure-sensitive adhesive surface until it is used. In addition, the pressure-sensitive adhesive sheet may further contain any appropriate other layer as long as the effects of the present invention can be obtained. Preferably, the substrate and the transfer layer are laminated directly (that is, without interposing another layer).

The pressure-sensitive adhesive sheet of the present invention can be used to temporarily fix a member to a support (for example, a glass substrate) using the pressure-sensitive adhesive sheet, and peel the member from the support after transfer, processing, and the like. The pressure-sensitive adhesive sheet can be used by attaching the pressure-sensitive adhesive layer to a support (for example, a glass substrate). At the time of peeling, laser light irradiation is performed, and only a member at a desired position can be peeled with pinpoint accuracy. In the pressure-sensitive adhesive sheet, the transfer layer may be a layer exhibiting releasability upon irradiation with a laser beam. Moreover, laser light irradiation can be performed from the pressure-sensitive adhesive layer side. In the pressure-sensitive adhesive sheet, the base material is partially distorted by laser light irradiation, and this distortion propagates to the transfer layer, temporarily changing the shape of the transfer layer surface (adhering surface). It becomes possible to peel off the member (adherend) arranged at the location. In the present invention, by adjusting the components of the pressure-sensitive adhesive layer (for example, the type of base polymer, etc.), the pressure-sensitive adhesive layer can transmit a laser beam of a predetermined wavelength, and as a result, distortion of the substrate is likely to occur. . By appropriately selecting the constituent materials of the base material, the base material can be easily strained. For example, if the substrate is configured so that laser light of a predetermined wavelength is difficult to pass through, the substrate can be easily distorted. In the present invention, the peelability is exhibited by the above action, so a high-power laser beam is not required, the step of washing the adherend after peeling is unnecessary, and the peeling area is narrowed. be able to. In addition, after peeling, the change in the surface shape of the transfer layer does not persist (that is, it does not widen over time, but rather can return to the shape before the change). It is possible to prevent troubles such as unnecessary dropping of the adherend.

In particular, the present invention is advantageous in that the power of laser light irradiation required for peeling can be reduced. When the pressure-sensitive adhesive sheet of the present invention is used, peeling occurs preferably by low-power laser light irradiation, so damage to the member to be processed is small, and unnecessary deformation of the pressure-sensitive adhesive layer and accompanying detachment from the support are prevented. be able to. In addition, the pressure-sensitive adhesive sheet of the present invention can contribute to production cost reduction. Moreover, the use of the pressure-sensitive adhesive sheet of the present invention is advantageous in that the range of selection of manufacturing equipment is widened.

The adhesive force I at 23° C. when the adhesive layer of the adhesive sheet is attached to a glass plate is preferably 0.02 N/20 mm or more, more preferably 2 N/20 mm or more, and still more preferably 2 N/ It is 20 mm to 25 N/20 mm, more preferably 5 N/20 mm to 20 N/20 mm. Within such a range, the deformation of each layer due to laser light irradiation can be optimized, the range where peeling occurs can be narrowed, and the adherend is unnecessarily detached at locations where peeling is not desired. Such troubles can be prevented. Adhesion is measured according to JIS Z 0237:2000. Specifically, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is adhered to a glass plate (arithmetic mean surface roughness Ra: 50 ± 25 nm) by reciprocating a 2 kg roller once, and left at 23 ° C. for 30 minutes. It is measured by peeling off the pressure-sensitive adhesive sheet under the conditions of 180° and peeling speed (tensile speed) of 300 mm/min.

The initial adhesive force A at 23° C. immediately after the transfer layer of the adhesive sheet is attached to the stainless steel plate is preferably 1 N/20 mm to 20 N/20 mm, more preferably 1.5 N/20 mm to 15 N/20 mm. , more preferably 2 N/20 mm to 10 N/20 mm. Within such a range, it is possible to obtain a pressure-sensitive adhesive sheet that can hold an adherend well. Adhesion 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 reciprocating a 2 kg roller once, left at 23° C. for 30 minutes, and peeled at a peeling angle of 180. °, peeling speed (tensile speed) of 300 mm/min, peel off the pressure-sensitive adhesive sheet and measure. The adhesive strength of the transfer layer changes due to irradiation with active energy rays and laser light, and the term "initial adhesive strength" as used herein means the adhesive strength before irradiation with active energy rays and laser light.

In one embodiment, the adhesive sheet has an adhesive strength B at 23 ° C. after the adhesive sheet is attached to the stainless steel plate and the transfer layer is irradiated with ultraviolet rays of 300 mJ / cm ² (also known as adhesive strength B after curing is preferably 1 N/20 mm or less, more preferably 0.5 N/20 mm or less, still more preferably 0.2 N/20 mm or less, and particularly preferably 0.1 N/20 mm or less. Within such a range, it is possible to obtain a pressure-sensitive adhesive sheet with excellent releasability and little adhesive residue. The lower limit of the post-curing adhesive strength B is, for example, 0.01 N/20 mm (preferably 0.001 N/20 mm). The ultraviolet irradiation is performed by, for example, using an ultraviolet irradiation device (manufactured by Nitto Seiki Co., Ltd., trade name “UM-810”) and applying ultraviolet rays (characteristic wavelength: 365 nm, integrated light amount: 300 mJ/cm ² ) from a high-pressure mercury lamp to the transfer layer. It is done by irradiation. Ultraviolet irradiation can be performed from the pressure-sensitive adhesive layer side.

The ratio of the adhesive strength I at 23° C. to the adhesive strength B after curing of the transfer layer when the adhesive layer is attached to the glass (adhesive strength I/adhesive strength after curing B) is 5 or more. In other words, in the adhesive sheet, the post-curing adhesive strength B is 0.2 times or less (preferably 0.1 times or less, more preferably 0.05 times or less, and still more preferably 0.02 times) the adhesive strength I after curing. below). By specifying (adhesive strength I/adhesive strength after curing B) as described above, it is possible to optimize the deformation of each layer due to laser light irradiation, and to obtain a pressure-sensitive adhesive sheet that is excellent in peelability due to laser light irradiation. be able to. Such a pressure-sensitive adhesive sheet can achieve reliable releasability 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 50 or more, particularly preferably 70 or more, and most preferably 90 or more. be. Within such a range, the effect of the present invention is remarkable. The upper limit of (adhesive strength I/post-curing adhesive strength B) is, for example, 1,000, preferably 5,000, and more preferably 10,000. That is, in the pressure-sensitive adhesive sheet, the post-curing adhesive force B can be 0.0001 times or more the adhesive force I.

The ratio of the initial adhesive strength A of the transfer layer to the adhesive strength B after curing of the transfer layer (initial adhesive strength A/adhesive strength B after curing) is preferably 5 or more, more preferably 10 or more, and more preferably 10 to 100, more preferably 20 to 100, particularly preferably 30 to 80. Within such a range, it is possible to obtain a pressure-sensitive adhesive sheet having an excellent balance between fixability and releasability of an adherend.

In the pressure-sensitive adhesive sheet, the anchoring force at 23° C. between the layers (e.g., transfer layer, base material, other layers) arranged in contact with the pressure-sensitive adhesive layer and 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, 30N/20mm (preferably 50N/20mm). The anchoring force is measured by peeling off the adhesive layer from the adjacent layer under the conditions of 23° C., 180° peeling angle, and 300 mm/min peeling speed (tensile speed).

In the pressure-sensitive adhesive sheet, the anchoring force at 23° C. between a layer (e.g., pressure-sensitive adhesive layer, base material, other layer) disposed in contact with the transfer layer and the transfer layer is preferably 2 N/20 mm or more, It is 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, 30N/20mm (preferably 50N/20mm). The anchoring force is measured by peeling off the transfer layer from the adjacent layer under conditions of 23° C., a peel angle of 180°, and a peel speed (tensile speed) of 300 mm/min.

The haze value of the adhesive sheet of the present invention is preferably 70% or less, more preferably 65% or less. Within such a range, it is possible to obtain a pressure-sensitive adhesive sheet in which the transfer layer is favorably cured by irradiation with active energy rays. In one embodiment, the adhesive sheet has a haze value of 20% or less. The haze value of the adhesive sheet is preferably as low as possible, but its lower limit is, for example, 0.1%.

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

B. Transfer Layer The thickness of the transfer layer is preferably 50 µm or less, more preferably 40 µm or less, still more preferably 30 µm or less, particularly preferably 20 µm or less, most preferably 10 µm or less. Within such a range, strain generated in the base material is easily propagated to the surface of the transfer layer, and a pressure-sensitive adhesive sheet having excellent peelability can be obtained. The lower limit of the thickness of the transfer layer is, for example, 2 μm.

In one embodiment, the transfer layer is a layer that is cured by irradiation with active energy rays. More specifically, in the present embodiment, the transfer layer has adhesiveness for fixing the member (adherend), and is configured to be cured by irradiation with active energy rays to reduce the adhesiveness. be done. By irradiating the transfer layer with a laser beam after curing the transfer layer, it is possible to preferably develop peelability due to strain propagation. In addition, it is preferable that adhesive strength to the extent that the adherend can be fixed (for example, adhesive strength to the extent that the adherend does not fall naturally) remains even after curing. In one embodiment, the irradiation with active energy rays reduces the adhesive strength of the entire transfer layer. Examples of active energy rays include gamma rays, ultraviolet rays, visible rays, infrared rays (heat rays), radio waves, alpha rays, beta rays, electron beams, plasma currents, ionizing rays, and particle beams. Ultraviolet rays are preferred.

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, even more preferably 0.2 MPa to 5 MPa, and particularly preferably 0.5 MPa to 2 MPa. With such a range, it is possible to obtain a pressure-sensitive adhesive sheet with excellent fixability. The indentation modulus can be measured by the single indentation method at 23° C. with an indentation speed of 10 nm/s and an indentation depth of 100 nm. The adhesive strength of the transfer layer changes due to irradiation with active energy rays and laser light. In this specification, the term "initial indentation elastic modulus A" means the adhesive strength before irradiation with active energy rays and laser light. do.

The transfer layer is preferably a layer having an indentation elastic modulus B (also referred to as post-curing elastic modulus B) at 23° C. of 14 MPa or more after irradiation with ultraviolet rays of 300 mJ/cm ² , and a layer having 15 MPa or more. It is more preferable to be a layer of 20 MPa or more, more preferably of 50 MPa or more, and most preferably of 100 MPa or more. Within such a range, a pressure-sensitive adhesive sheet with excellent peelability can be obtained. In addition, contamination of the adherend during peeling can be prevented. The upper limit of the post-curing elastic modulus B at 23° C. is, for example, 500 MPa (preferably 300 MPa).

After being irradiated with ultraviolet rays of 300 mJ/cm ² , the indentation modulus B of the transfer layer at 23° C. is preferably 20 times or more, more preferably 30 times or more, the initial indentation modulus A of the transfer layer at 23° C. more preferably 30 to 1,000 times, and particularly preferably 50 to 200 times. Within such a range, it is possible to obtain a pressure-sensitive adhesive sheet having an excellent balance between fixability and releasability of an adherend.

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 the indentation elastic modulus I at 23° C. of the pressure-sensitive adhesive layer, preferably 10 times or more. more preferably 50-fold to 5000-fold, more preferably 80-fold to 4500-fold, and particularly preferably 100-fold to 3000-fold. Within such a range, deformation of each layer by laser light irradiation can be optimized, and a pressure-sensitive adhesive sheet with excellent peelability by laser light irradiation can be obtained. Such a pressure-sensitive adhesive sheet can achieve reliable releasability in a narrow range.

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

(Active energy ray-curable adhesive)
In one embodiment, the active energy ray-curable pressure-sensitive adhesive is an active energy ray-curable adhesive containing a base polymer as a base material and an active energy ray-reactive compound (monomer or oligomer) capable of bonding with the base polymer. An adhesive (A1) is used. In another embodiment, an active energy ray-curable pressure-sensitive adhesive (A2) containing an active energy ray-reactive polymer as a base polymer is used. Preferably, the base polymer has functional groups capable of reacting with the photoinitiator. Examples of the functional group include hydroxyl group and carboxyl group.

Examples of the base polymer used in the adhesive (A1) include natural rubber, polyisobutylene rubber, styrene/butadiene rubber, styrene/isoprene/styrene block copolymer rubber, recycled rubber, butyl rubber, polyisobutylene rubber, and nitrile rubber. rubber-based polymers such as (NBR); silicone-based polymers; and acrylic polymers. These polymers may be used alone or in combination of two or more. Among them, acrylic polymers are preferred.

Examples of acrylic polymers include homopolymers and copolymers of hydrocarbon group-containing (meth)acrylic esters such as (meth)acrylic acid alkyl esters, (meth)acrylic acid cycloalkyl esters, and (meth)acrylic acid aryl esters. a copolymer of the hydrocarbon group-containing (meth)acrylic acid ester and another copolymerizable monomer; (Meth)acrylic acid alkyl esters include, for example, (meth)acrylic acid methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, s-butyl ester, t-butyl ester, pentyl ester, iso Pentyl ester, hexyl ester, heptyl ester, octyl ester, 2-ethylhexyl ester, isooctyl ester, nonyl ester, decyl ester, isodecyl ester, undecyl ester, dodecyl ester or lauryl ester, tridecyl ester, tetradecyl ester, hexa Decyl esters, octadecyl esters, and eicosyl esters are included. (Meth)acrylic acid cycloalkyl esters include, for example, cyclopentyl and cyclohexyl esters of (meth)acrylic acid. (Meth)acrylic acid aryl esters include, for example, phenyl (meth)acrylate and benzyl (meth)acrylate. The content of structural units derived from the hydrocarbon group-containing (meth)acrylic acid ester is preferably 40 parts by weight or more, more preferably 60 parts by weight or more, relative to 100 parts by weight of the base polymer.

Examples of other copolymerizable monomers include carboxy group-containing monomers, acid anhydride monomers, hydroxy group-containing monomers, glycidyl group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, acrylamide, and acrylonitrile. Examples include functional group-containing monomers. Carboxy group-containing monomers include, for example, acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Anhydride monomers include, for example, maleic anhydride and itaconic anhydride. Examples of hydroxy group-containing monomers 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. Glycidyl group-containing monomers include, for example, glycidyl (meth)acrylate and methylglycidyl (meth)acrylate. Sulfonic acid group-containing monomers include, for example, styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, and (meth) ) acryloyloxynaphthalene sulfonic acid. Phosphate group-containing monomers include, for example, 2-hydroxyethyl acryloyl phosphate. Acrylamides include, for example, N-acryloylmorpholine. These may be used individually by 1 type, and may be used in combination of 2 or more type. The content of structural units derived from the copolymerizable monomer is preferably 60 parts by weight or less, more preferably 40 parts by weight or less, relative 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 crosslinked structure in the polymer backbone. Examples of polyfunctional monomers include 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, (meth)acrylates, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy (meth)acrylate (i.e. polyglycidyl (meth)acrylate), polyester (meth)acrylate ) acrylates, and urethane (meth)acrylates. 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, more preferably 30 parts by weight or less, relative 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 in the adhesive (A1) include a functional group having a polymerizable carbon-carbon multiple bond such as an acryloyl group, a methacryloyl group, a vinyl group, an allyl group, and an acetylene group. photoreactive monomers or oligomers having Specific examples of the photoreactive monomer include trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol mono Hydroxy penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate ( Esterified product of meth)acrylic acid and polyhydric alcohol; polyfunctional urethane (meth)acrylate; epoxy (meth)acrylate; oligoester (meth)acrylate and the like. Also, monomers such as methacryloylisocyanate, 2-methacryloyloxyethyl isocyanate (2-isocyanatoethyl methacrylate), m-isopropenyl-α,α-dimethylbenzyl isocyanate may be used. Specific examples of photoreactive oligomers include dimers to pentamers of the above monomers. The molecular weight of the photoreactive oligomer is preferably 100-3000.

Further, as the active energy ray-reactive compound, monomers such as epoxidized butadiene, glycidyl methacrylate, acrylamide, and vinylsiloxane; or oligomers composed of such monomers may be used.

Furthermore, 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. When the mixture is irradiated with an active energy ray (e.g., ultraviolet rays, electron beams), the organic salt is cleaved to generate ions, which act as starting species to cause a heterocyclic ring-opening reaction to form a three-dimensional network structure. can. Examples of the organic salts include iodonium salts, phosphonium salts, antimonium salts, sulfonium salts, borate salts and the like. Examples of the heterocyclic ring in the compound having a plurality of heterocyclic rings in the molecule include oxirane, oxetane, oxolane, thiirane, aziridine and the like.

In the adhesive (A1), the content of the active energy ray-reactive compound is preferably 0.1 parts by weight to 500 parts by weight, more preferably 5 parts by weight to 300 parts by weight, with respect to 100 parts by weight of the base polymer. parts by weight, more preferably 40 to 150 parts by weight.

Examples of the active energy ray-reactive polymer (base polymer) contained in the adhesive (A2) include functional groups having carbon-carbon multiple bonds such as acryloyl groups, methacryloyl groups, vinyl groups, allyl groups, and acetylene groups. polymer having Specific examples of active energy ray-reactive polymers include polymers composed of polyfunctional (meth)acrylates; photo-cationically polymerizable polymers; cinnamoyl group-containing polymers such as polyvinyl cinnamate; diazotized amino novolak resins; ; and the like.

In one embodiment, an active energy ray-reactive polymer is formed by introducing an active energy ray-polymerizable carbon-carbon multiple bond into the side chain, main chain and/or end of the main chain of the acrylic polymer. Used. As a technique for introducing a radiation-polymerizable carbon-carbon double bond into an acrylic polymer, for example, an acrylic polymer is obtained by copolymerizing raw material monomers containing a monomer having a predetermined functional group (first functional group). After obtaining, a compound having a predetermined functional group (second functional group) and a radiation-polymerizable carbon-carbon double bond capable of reacting with and bonding to the first functional group is carbon-carbon A method of subjecting an acrylic polymer to a condensation reaction or an addition reaction while maintaining the radiation polymerizability of the double bond can be mentioned.

Combinations of the first functional group and the second functional group include, for example, 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 hydroxy group and an isocyanate group, and an isocyanate group. and hydroxy groups. Among these combinations, a combination of a hydroxy group and an isocyanate group and a combination of an isocyanate group and a hydroxy group are preferable from the viewpoint of ease of reaction tracking. In addition, it is technically difficult to produce a polymer having a highly reactive isocyanate group. More preferred is when the group is a hydroxy group and said second functional group is an isocyanate group. In this case, examples of isocyanate compounds having both a radiation-polymerizable carbon-carbon double bond and an isocyanate group as the second functional group include methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate, m-isopropenyl-α, and α-dimethylbenzyl isocyanate. Further, the acrylic polymer having the first functional group preferably contains a structural unit derived from the hydroxy group-containing monomer, such as 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether. It is also preferable to contain a constitutional unit derived from an ether-based compound.

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

The active energy ray-curable adhesive may contain an ultraviolet absorber and/or a photopolymerization initiator. The details of the ultraviolet absorber and photopolymerization initiator used will be described later.

In one embodiment, the active energy ray-curable pressure-sensitive adhesive may contain a photosensitizer. Examples of photosensitizers include "UVS-581" (trade name) manufactured by Kawasaki Chemical Industries, Ltd., and 9,10-diethoxyanthracene (eg, "UVS-1101" (trade name) manufactured by Kawasaki Chemical Industries, Ltd.). Other examples of the photosensitizer include 9,10-dibutoxyanthracene (eg, trade name “UVS-1331” manufactured by Kawasaki Chemical Industries, Ltd.), 2-isopropylthioxanthone, benzophenone, thioxanthone derivatives, 4,4 '-bis(dimethylamino)benzophenone and the like. Thioxanthone derivatives include, for example, ethoxycarbonylthioxanthone and isopropylthioxanthone.

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

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

The content of the cross-linking agent is preferably 0.5 to 10 parts by weight, more preferably 1 to 8 parts by weight, with respect to 100 parts by weight of the base polymer of the adhesive.

In one embodiment, an isocyanate-based cross-linking agent is preferably used. An isocyanate-based cross-linking agent is preferable because it can react with various functional groups. Specific examples of the isocyanate-based cross-linking agents include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; Aromatic isocyanates such as tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate; trimethylolpropane/tolylene diisocyanate trimer adduct (manufactured by Tosoh Corporation, trade name "Coronate L"), trimethylolpropane / Isocyanate adducts such as hexamethylene diisocyanate trimer adduct (manufactured by Tosoh Corporation, trade name "Coronate HL"), isocyanurate form of hexamethylene diisocyanate (manufactured by Tosoh Corporation, trade name "Coronate HX"); mentioned. Preferably, a cross-linking agent having 3 or more isocyanate groups is used.

The active energy ray-curable adhesive may further contain any suitable additive as necessary. Additives include, for example, active energy ray polymerization accelerators, radical scavengers, coupling agents (e.g., silane coupling agents), tackifiers, plasticizers (e.g., trimellitic acid ester plasticizers, pyromellitic acid ester plasticizers, etc.), pigments, dyes, fillers, antioxidants, conductive materials, antistatic agents, light stabilizers, release modifiers, softeners, surfactants, flame retardants, antioxidants, particles, ultraviolet rays Absorbents and the like are included.

(Photoinitiator)
Any appropriate initiator can be used as the photopolymerization initiator. Examples of photopolymerization initiators include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2-hydroxypropio α-ketol compounds such as phenone and 1-hydroxycyclohexylphenyl ketone; methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1-[4-(methylthio) Acetophenone compounds such as -phenyl]-2-morpholinopropane-1; benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether; ketal compounds such as benzyl dimethyl ketal; 2-naphthalenesulfonyl chloride, etc. aromatic sulfonyl chloride compounds; 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl) oxime and other photoactive oxime compounds; benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4 -benzophenone compounds such as methoxybenzophenone; thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4 thioxanthone-based compounds such as diethylthioxanthone and 2,4-diisopropylthioxanthone; camphorquinone; halogenated ketones; The amount of photopolymerization initiator used can be set to any appropriate 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 amount of the photopolymerization initiator used can be set to any appropriate amount.

A commercially available product may be used as the photopolymerization initiator. For example, as a photopolymerization initiator having a maximum absorption wavelength in the range of 400 nm or less, BASF trade names "Irgacure 127", "Irgacure 369", "Irgacure 369E", "Irgacure 379", "Irgacure 379EG", " Irgacure 819", "Irgacure TOP", "Irgacure 784", and "Irgacure OXE01".

C. Adhesive layer The thickness of the adhesive layer is preferably 2 to 50 µm, more preferably 2 to 40 µm, still more preferably 2 to 30 µm. Within such a range, deformation of each layer by laser light irradiation can be optimized, and a pressure-sensitive adhesive sheet with excellent peelability by laser light irradiation can be obtained. Such a pressure-sensitive adhesive sheet can achieve reliable releasability in a narrow range.

The indentation modulus I of the adhesive layer at 23°C is preferably 0.03 MPa to 20 MPa, more preferably 0.05 MPa to 10 MPa, and still more preferably 0.06 MPa to 5 MPa. Within such a range, deformation of each layer by laser light irradiation can be optimized, and a pressure-sensitive adhesive sheet with excellent peelability by laser light irradiation can be obtained. Such a pressure-sensitive adhesive sheet can achieve reliable releasability in a narrow range.

The light transmittance of the pressure-sensitive adhesive layer at a wavelength of 248 nm is preferably 25% or more, more preferably 40% or more, still more preferably 55% or more, particularly preferably 80% or more, and most preferably. is 90% or more. The light transmittance of the pressure-sensitive adhesive layer at a wavelength of 248 nm is preferably as high as possible, but its upper limit is, for example, 99%. Within such a range, the laser beam can effectively reach the base material during peeling by laser beam irradiation, and excellent peelability can be achieved.

The adhesive layer contains a silicone-based adhesive. A silicone-based pressure-sensitive adhesive contains a silicone-based polymer as a base polymer. By using a silicone-based pressure-sensitive adhesive, a pressure-sensitive adhesive layer having excellent transparency to light of a predetermined wavelength can be formed. As a result, the laser light effectively reaches the base material during the peeling by laser light irradiation, and excellent peelability can be realized.

Any appropriate adhesive can be used as the silicone-based adhesive as long as the effects of the present invention can be obtained. As the silicone-based pressure-sensitive adhesive, for example, a silicone-based pressure-sensitive adhesive having a base polymer such as silicone rubber containing organopolysiloxane or silicone resin is preferably used. A base polymer obtained by cross-linking the above silicone rubber or silicone resin may be used as the base polymer constituting the silicone pressure-sensitive adhesive. In the present specification, the term "silicone rubber" means a polymer (e.g., a viscosity of 1000 Pa s) in which diorganosiloxane (D unit) as a main component is linked in a straight chain, and a "silicone resin". means a polymer composed of triorganosilhemioxane (M unit) and silicate (Q unit) as main components (“Material design and functionalization of adhesives (films and tapes)”, Technical Information Association, September 30, 2009).

Examples of the silicone rubber include organopolysiloxane containing dimethylsiloxane as a structural unit. A functional group (for example, a vinyl group) may be introduced into the organopolysiloxane, if necessary. The weight average molecular weight of the organopolysiloxane is preferably from 100,000 to 1000,000, more preferably from 150,000 to 500,000. A weight average molecular weight can be measured by GPC (solvent: THF).

Examples of the silicone resin include organopolysiloxanes containing at least one structural unit selected from R ₃ SiO _1/2 structural units, SiO ₂ structural units, RSiO _3/2 structural units and R ₂ SiO structural units. (R is a monovalent hydrocarbon or hydroxyl group).

The above silicone rubber and silicone resin may be used in combination. The weight ratio of the silicone rubber to the silicone resin (rubber:resin) in the silicone adhesive is preferably 100:0 to 100:220, more preferably 100:0 to 100:180, still more preferably 100: 10-100:100. The silicone rubber and the silicone resin may be contained in the silicone pressure-sensitive adhesive as a simple mixture, or may be contained in the silicone pressure-sensitive adhesive in the form of partial condensation of the silicone rubber and the silicone resin. The rubber:resin ratio can also be determined from the ratio of Q units (resin) to D units (rubber) obtained by measuring the composition of the silicone adhesive by ²⁹ Si-NMR.

The silicone-based pressure-sensitive adhesive may contain any suitable additive as necessary. The additives include, for example, cross-linking agents, vulcanizing agents, tackifiers, plasticizers, pigments, dyes, fillers, anti-aging agents, conductive materials, antistatic agents, ultraviolet absorbers, light stabilizers, and release control agents. agents, softeners, surfactants, flame retardants, antioxidants and the like.

Preferably, the silicone pressure-sensitive adhesive contains a cross-linking agent. Examples of the cross-linking agent include siloxane-based cross-linking agents and peroxide-based cross-linking agents. Any appropriate cross-linking agent can be used as the peroxide-based cross-linking agent. Peroxide cross-linking agents include, for example, benzoyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide and the like. Examples of siloxane-based cross-linking agents include polyorganohydrogensiloxanes. The polyorganohydrogensiloxane preferably has two or more silicon-bonded hydrogen atoms. The polyorganohydrogensiloxane preferably has an alkyl group, a phenyl group, or a halogenated alkyl group as functional groups bonded to silicon atoms.

A commercially available product may be used as the silicone adhesive. Specific examples of commercially available products include SD series manufactured by Dow Toray Industries, KR-3700 series, X-40 series and KR-100 series manufactured by Shin-Etsu Chemical Co., Ltd.

The solid content of the silicone adhesive is preferably 50 parts by weight or more, more preferably 80 parts by weight or more, and still more preferably 90 parts by weight or more, relative to 100 parts by weight of the adhesive layer.

D. Substrate The substrate may be composed of any suitable resin. Examples of the resin include polyolefin-based resins such as polyethylene-based resins, polypropylene-based resins, polybutene-based resins, and polymethylpentene-based resins, polyurethane-based resins, polyester-based resins, polyimide-based resins, polyetherketone-based resins, and polystyrene-based resins. Resins, polyvinyl chloride resins, polyvinylidene chloride resins, fluorine resins, silicon resins, cellulose resins, ionomer resins, and the like can be mentioned.

In one embodiment, the substrate is made of polyester resin and/or polyimide resin. Base materials made of these resins are advantageous in that they have low light transmittance at a wavelength of 248 nm and are easily distorted by laser light irradiation.

The light transmittance of the base material at a wavelength of 248 nm is preferably 60% or less, more preferably 30% or less, even more preferably 15% or less, and particularly preferably 10% or less. Within such a range, the substrate can be easily distorted by laser light irradiation. The lower limit of the light transmittance of the substrate at a wavelength of 248 nm is, for example, 0.005%.

The thickness of the base material 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 thickness of the substrate is 50 µm or less, more preferably 30 µm or less, still more preferably 20 µm or less, particularly preferably 15 µm or less, and most preferably 10 µm or less. . By reducing the thickness of the base material, the strain generated in the base material is easily propagated to the transfer layer, and a pressure-sensitive adhesive sheet having excellent peelability can be obtained.

The indentation elastic modulus of the base material at 23°C is preferably 5000 MPa or less, more preferably 3000 MPa or less, and still more preferably 1000 MPa or less. Within such a range, the base material can easily propagate strain to the transfer layer. The lower limit of the indentation modulus of the substrate at 23° C. is preferably 1 MPa, more preferably 5 MPa, and still more preferably 10 MPa. Within such a range, it is possible to obtain a pressure-sensitive adhesive sheet having appropriate rigidity and excellent handleability.

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

E. Production method of pressure-sensitive adhesive sheet The above-mentioned pressure-sensitive adhesive sheet can be produced by any appropriate method. The pressure-sensitive adhesive sheet can be obtained, for example, by applying the above-mentioned pressure-sensitive adhesives forming the pressure-sensitive adhesive layer and the transfer layer onto a base material or a release liner. Coating methods include bar coater coating, air knife coating, gravure coating, gravure reverse coating, reverse roll coating, lip coating, die coating, dip coating, offset printing, flexographic printing, screen printing, etc. Various methods 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, and bonding them together, or by bonding these to a substrate.

F. Method of Using the Adhesive Sheet The adhesive sheet of the present invention can be used to temporarily fix any suitable work member (for example, an electronic component) during processing and/or transfer of the work member. As a method of using the pressure-sensitive adhesive sheet of the present invention, for example, (i) the pressure-sensitive adhesive layer is attached to the support, (ii) the member to be processed is attached and fixed to the transfer layer of the adherend sheet, and (ii) the adhesive layer is attached to the support. ) processing or transferring the member to be processed, (iii) irradiating the adhesive sheet with an active energy ray (e.g., ultraviolet rays) to reduce the adhesive strength of the adhesive sheet on the transfer layer side, and (iv) exhibiting peelability. A method of using the pressure-sensitive adhesive layer by irradiating a desired portion with a laser beam to cause strain in the pressure-sensitive adhesive layer is exemplified. According to this method, it is possible to separate the workpiece by natural fall. Moreover, when a plurality of workpieces are temporarily fixed, it is also possible to peel off only a part of them. By using the adhesive sheet of the present invention, the adhesive force can be reduced to the point that it naturally falls, so even very small (for example, 50 μm square) workpieces can be individually peeled off. is. Examples of the member include semiconductor wafers, optical semiconductor elements, miniLEDs, microLEDs, and the like.

For example, a glass plate is used as the support in (i) above. Preferably, the support is light transmissive. The total light transmittance of the support is, for example, 50% or more, preferably 80% or more.

In one embodiment, the active energy ray in (iii) above is irradiated from the adhesive layer side (substantially, the support side) of the adhesive sheet.

In one embodiment, the laser light in (iv) above is irradiated from the adhesive layer side (substantially, the support side) of the adhesive sheet.

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

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Tests and evaluation methods in Examples are as follows. Also, "parts" and "%" are by weight unless otherwise specified.

(1) Adhesive strength I of adhesive layer to glass
The PET release liner on the transfer layer side of the adhesive sheet was peeled off, and PET (Lumirror S10 manufactured by Toray Industries, Inc.) having a thickness of 25 μm was adhered. After that, the PET release liner on the other side is peeled off, and a 2 kg roller is reciprocated once to bond it to a glass plate (manufactured by Matsunami Glass Industry Co., Ltd., trade name "S200423"). The adhesive force was measured at an angle of 180°, a peeling speed (tensile speed) of 300 mm/min, and a measurement temperature of 23°C.

(2) Adhesive strength of the transfer layer to the stainless steel plate The PET release liner on the adhesive layer side of the adhesive sheet (in Comparative Example 4, the PET release liner attached to the transfer layer) was peeled off, and PET (Lumirror manufactured by Toray) with a thickness of 25 µm was removed. S10) was pasted together. After that, the PET release liner on the other side was peeled off, and a 2-kg roller was reciprocated once to bond it to SUS304. Measurement temperature: 23°C), and the initial adhesive strength A was obtained.
In the same manner, after bonding the adhesive sheet to SUS304, from the adhesive layer side, using an ultraviolet irradiation device (manufactured by Nitto Seiki, trade name “UM-810”), ultraviolet light from a high-pressure mercury lamp (specific wavelength: 365 nm, cumulative After irradiating the entire surface with a light intensity of 300 mJ/cm ² , the adhesive strength was measured in the same manner, and was defined as adhesive strength B after curing.

(3) Indentation modulus (before curing)
The indentation elastic modulus of the pressure-sensitive adhesive layer and the transfer layer was measured using a tripoindenter TI-950 manufactured by Hysitron. The measurements were made by the single indentation method at 23° C. with an indentation speed of 10 nm/s and an indentation depth of 100 nm.

(4) Indentation modulus (after curing)
The PET release liner on the adhesive layer side of the adhesive sheet (in Comparative Example 4, the PET release liner attached to the transfer layer) was peeled off, and a hand roller was used on a large slide glass (manufactured by Matsunami Glass, trade name "S9111"). pasted together. Using an ultraviolet irradiator (manufactured by Nitto Seiki, trade name “UM-810”) from the side of the slide glass of the obtained sample, the entire surface was exposed to ultraviolet light from a high-pressure mercury lamp (specific wavelength: 365 nm, integrated light amount: 300 mJ/cm ² ). irradiated. Thereafter, the other PET release liner was peeled off to expose the transfer layer, and the indentation modulus was measured using a tripoindenter TI-950 manufactured by Hysitron. The measurements were made by the single indentation method at 23° C. with an indentation speed of 10 nm/s and an indentation depth of 100 nm.

(5) Light transmittance A spectrophotometer (trade name “Spectrophotometer U-4100” manufactured by Hitachi High-Tech Science) was used to measure the light transmittance of the pressure-sensitive adhesive layer and the substrate at 248 nm.

(6) Peelability (transferability)
The PET separator on the adhesive layer side of the adhesive sheet (in Comparative Example 4, the PET release liner attached to the transfer layer) was peeled off, and attached to a quartz plate (manufactured by AS ONE) using a hand roller. After that, the PET release liner on the other side was peeled off, and a silicon chip of 125 μm×100 μm was attached to the adhesive side of the transfer layer.
From the quartz plate surface side, the entire surface was irradiated with ultraviolet light from a high-pressure mercury lamp (specified wavelength: 365 nm, integrated light amount: 300 mJ/cm ² ) using an ultraviolet irradiation device (manufactured by Nitto Seiki, trade name “UM-810”).
After that, a laser beam with a wavelength of 248 nm is irradiated only to the target member position from the quartz plate side while changing the output (1 plus per chip; irradiation area: 130 μm × ¹⁰⁵ μm). was evaluated as pass (◯), and the case where free fall occurred at an output of 50 mJ/cm ² or less was evaluated as failure (x).

(7) Presence or Absence of Deformation In the evaluation of (7) above, the deformation of the surface of the transfer layer was observed after irradiation with laser light at the laser light output (“transfer energy” in the table) during free fall. A case in which a significant color difference was observed between the laser-irradiated portion and the other portion was evaluated as unsatisfactory (×), and a case in which this was not observed was evaluated as acceptable (◯).

(8) Adhesive residue The glass plate was visually observed after the evaluation of "(1) Adhesive strength of adhesive layer to glass". When the adhesive layer remained on the glass, it was rejected (X), and when not, it was accepted (○).

[Production Example 1] Preparation 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.
Next, nitrogen was introduced into a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirrer, and under a nitrogen atmosphere, 103.1 parts by weight of the above monomer composition, 0.2 parts by weight of benzoyl peroxide (BPO), and toluene were mixed. 150 parts by weight was charged and stirred at 60° C. for 6 hours to obtain acrylic polymer solution I containing acrylic polymer I.

[Production Example 2] Preparation 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 introduction tube, a thermometer, and a stirrer, and under a nitrogen atmosphere, 295 parts by weight of toluene, 109 parts by weight of the above monomer composition, and 0.2 parts of benzoyl peroxide (BPO) were added. Parts by weight were charged and stirred at 60° C. for 4 hours to obtain acrylic polymer solution II containing acrylic polymer II having a weight average molecular weight of 500,000.

[Production Example 3] Preparation 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 tube, a thermometer, and a stirrer, and under a nitrogen atmosphere, 102.01 parts by weight of the above monomer composition, 0.2 parts by weight of benzoyl peroxide (BPO), and toluene were mixed. 189 parts by weight were charged and stirred at 60° C. for 7 hours to obtain acrylic polymer solution III containing acrylic polymer III.

[Production Example 4] Preparation of Acrylic Polymer IV 100 parts by weight of 2-methoxyethyl acrylate, 27 parts by weight of acryloylmorpholine and 22 parts by weight of 2-hydroxyethyl acrylate were mixed to prepare a monomer composition.
Next, nitrogen was introduced into a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirrer, and under a nitrogen atmosphere, 500 parts by weight of toluene, 149 parts by weight of the above monomer composition, and 0.3 parts of benzoyl peroxide (BPO) were added. Parts by weight were charged and stirred at 60° C. for 5 hours. Then, it is cooled to room temperature, and 24 parts by weight of 2-methacryloyloxyethyl isocyanate is added and reacted to add an NCO group to the side chain terminal OH group of 2-hydroxyethyl acrylate in the copolymer, and carbon at the end. - An acrylic polymer solution IV containing an acrylic polymer IV having a carbon double bond was obtained.

[Production Example 5] Preparation of acrylic polymer V 100 parts by weight of butyl acrylate, 78 parts by weight of ethyl acrylate, and 40 parts by weight of hydroxyethyl acrylate were mixed to prepare a monomer composition.
Next, nitrogen was introduced into a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirrer, and under a nitrogen atmosphere, 507 parts by weight of toluene, 218 parts by weight of the above monomer composition, and 1.2 parts of benzoyl peroxide (BPO) were mixed. Parts by weight were charged and stirred at 60° C. for 5 hours. Then, it is cooled to room temperature, and 42.6 parts by weight of 2-methacryloyloxyethyl isocyanate is added and reacted to add an NCO group to the side chain terminal OH group of 2-hydroxyethyl acrylate in the copolymer, and An acrylic polymer solution V containing an acrylic polymer V having a carbon-carbon double bond was obtained.

[Example 1]
100 parts by weight of a silicone polymer (manufactured by Dow Toray Industries, trade name "DOWSIL SD 4584 PSA") was applied to the surface of a PET release liner (PET38X1-SS4A, manufactured by Nippa Corporation, thickness: 38 μm) treated with silicone fluoride, and 0.9 parts by weight of mixture A of a catalyst (manufactured by Dow Toray Industries, trade name "DOWSIL SRX212") was applied and then heated at 100° C. for 3 minutes to form an adhesive layer with a thickness of 4 μm.
Acrylic polymer solution III containing 100 parts by weight of acrylic polymer III, 5 parts by weight of a cross-linking agent (manufactured by Tosoh Corporation, product name "Coronate L"), and 10 parts by weight of a photopolymerization initiator (manufactured by BASF, product name "Irgacure 127") were added to obtain a pressure-sensitive adhesive (A) for forming a transfer layer. The pressure-sensitive adhesive (A) is applied to the silicone-treated surface of a PET release liner (trade name HY-75Gt, manufactured by Higashiyama Film Co., Ltd., thickness: 75 μm), and then heated at 120° C. for 2 minutes to give a thickness of 5 μm. to form a transfer layer.
On one side of a PET substrate (manufactured by Toray Industries, Inc., product name “Lumirror S-10”, thickness: 12 μm), the above adhesive layer with a PET release liner is attached, and the other side is the above with a PET release liner. The transfer layer was laminated to obtain an adhesive sheet consisting of PET release liner/adhesive layer/substrate/transfer layer/PET release liner.
The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 1 shows the results.

[Example 2]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that 5 parts by weight of an additive (manufactured by Dow Toray Co., Ltd., trade name "CP-96 Black") was further added to the above mixture A to form a transfer layer. rice field. The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 1 shows the results.

[Example 3]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that 5 parts by weight of an additive (manufactured by BASF, trade name "Tinuvin 477") was further added to the mixture A to form a transfer layer. The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 1 shows the results.

[Example 4]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that 5 parts by weight of an additive (manufactured by BASF, trade name "TinuvinPS") was further added to the mixture A to form a transfer layer. The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 1 shows the results.

[Example 5]
Instead of 100 parts by weight of a silicone polymer (manufactured by Dow Toray Industries, trade name "DOWSIL SD 4584 PSA"), 100 parts by weight of a silicone polymer (manufactured by Dow Toray Industries, trade name "DOWSIL SD 4580 PSA") is used. A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that the The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 1 shows the results.

[Example 6]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that the thickness of the pressure-sensitive adhesive layer was 12 μm. The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 1 shows the results.

[Example 7]
Example 1 except that a PET base material (manufactured by Toray Industries, Inc., trade name "Lumirror 2DC61", thickness: 2 μm) was used instead of the PET base material (manufactured by Toray Industries, Inc., trade name "Lumirror S-10"). A pressure-sensitive adhesive sheet was obtained in the same manner as above. The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 1 shows the results.

[Example 8]
Instead of the PET base material (manufactured by Toray Industries, Inc., trade name "Lumirror S-10"), a polyimide base material (manufactured by Toray DuPont, trade name "Kapton 50H", thickness: 12 μm) was used. A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1. The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 1 shows the results.

[Example 9]
100 parts by weight of a silicone polymer (manufactured by Dow Toray Industries, trade name "DOWSIL SD 4584 PSA") was applied to the surface of a PET release liner (PET38X1-SS4A, manufactured by Nippa Corporation, thickness: 38 μm) treated with silicone fluoride, and 0.9 parts by weight of mixture A of a catalyst (manufactured by Dow Toray Industries, trade name "DOWSIL SRX212") was applied and then heated at 100° C. for 3 minutes to form an adhesive layer with a thickness of 4 μm.
Acrylic polymer solution IV containing 100 parts by weight of acrylic polymer IV, 3 parts by weight of a cross-linking agent (manufactured by Tosoh Corporation, product name "Coronate L"), and 10 parts by weight of a photopolymerization initiator (manufactured by BASF, product name "Irgacure 127") parts were added to obtain a pressure-sensitive adhesive (B) for forming a transfer layer. The pressure-sensitive adhesive (B) is applied to the silicone-treated surface of a PET release liner (trade name HY-75Gt, manufactured by Higashiyama Film Co., Ltd., thickness: 75 μm), and then heated at 120° C. for 2 minutes to give a thickness of 5 μm. to form a transfer layer.
On one side of a PET substrate (manufactured by Toray Industries, Inc., trade name “Lumirror S-10”, thickness: 12 μm), the above adhesive layer with a PET release liner is attached, and on the other side, the above adhesive layer with a PET release liner is attached. The transfer layer was laminated to obtain an adhesive sheet consisting of PET release liner/adhesive layer/substrate/transfer layer/PET release liner.
The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 1 shows the results.

[Example 10]
Instead of 100 parts by weight of a silicone polymer (manufactured by Dow Toray Industries, trade name "DOWSIL SD 4584 PSA"), 100 parts by weight of a silicone polymer (manufactured by Dow Toray Industries, trade name "DOWSIL LTC757 Coating") was used. A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except for the above. The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 1 shows the results.

[Comparative Example 1]
Acrylic polymer solution I containing 100 parts by weight of acrylic polymer I and a cross-linking agent (manufactured by Tosoh Corporation, product name "Coronate L ”) and 30 parts by weight of an additive (manufactured by Arakawa Chemical Industries, Ltd., trade name “D-125”), a mixture B is applied, and then heated at 100 ° C. for 3 minutes to form an adhesive with a thickness of 4 μm. A layer was formed.
Acrylic polymer solution III containing 100 parts by weight of acrylic polymer III, 5 parts by weight of a cross-linking agent (manufactured by Tosoh Corporation, product name "Coronate L"), and 10 parts by weight of a photopolymerization initiator (manufactured by BASF, product name "Irgacure 127") were added to obtain a pressure-sensitive adhesive (A) for forming a transfer layer. The pressure-sensitive adhesive (A) is applied to the silicone-treated surface of a PET release liner (trade name HY-75Gt, manufactured by Higashiyama Film Co., Ltd., thickness: 75 μm), and then heated at 120° C. for 2 minutes to give a thickness of 5 μm. to form a transfer layer.
On one side of a PET substrate (manufactured by Toray Industries, Inc., trade name “Lumirror S-10”, thickness: 12 μm), the above adhesive layer with a PET release liner is attached, and on the other side, the above adhesive layer with a PET release liner is attached. The transfer layer was laminated to obtain an adhesive sheet consisting of PET release liner/adhesive layer/substrate/transfer layer/PET release liner.
The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 1 shows the results.

[Comparative Example 2]
Acrylic polymer solution II containing 100 parts by weight of acrylic polymer II and a cross-linking agent (manufactured by Tosoh Corporation, product name "Coronate L ”) 8.5 parts by weight of mixture C was applied and then heated at 100° C. for 3 minutes to form an adhesive layer with a thickness of 4 μm.
Acrylic polymer solution III containing 100 parts by weight of acrylic polymer III, 5 parts by weight of a cross-linking agent (manufactured by Tosoh Corporation, product name "Coronate L"), and 10 parts by weight of a photopolymerization initiator (manufactured by BASF, product name "Irgacure 127") were added to obtain a pressure-sensitive adhesive (A) for forming a transfer layer. The pressure-sensitive adhesive (A) is applied to the silicone-treated surface of a PET release liner (trade name HY-75Gt, manufactured by Higashiyama Film Co., Ltd., thickness: 75 μm), and then heated at 120° C. for 2 minutes to give a thickness of 5 μm. to form a transfer layer.
On one side of a PET substrate (manufactured by Toray Industries, Inc., product name “Lumirror S-10”, thickness: 12 μm), the above adhesive layer with a PET release liner is attached, and the other side is the above with a PET release liner. The transfer layer was laminated to obtain an adhesive sheet consisting of PET release liner/adhesive layer/substrate/transfer layer/PET release liner.
The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 1 shows the results.

[Comparative Example 3]
An acrylic polymer solution containing 100 parts by weight of a polyester polymer (manufactured by Mitsubishi Chemical Co., Ltd., trade name "Nichigo Polyester NP110S50EO" I) was applied to the silicone-treated surface of a PET release liner (trade name MRF38, manufactured by Mitsubishi Plastics Co., Ltd., thickness: 38 μm). I, 2 parts by weight of a cross-linking agent (manufactured by Tosoh Corporation, trade name "Coronate L"), and 30 parts by weight of an additive (manufactured by Arakawa Chemical Industries, Ltd., trade name "D-125"). , and 100° C. for 3 minutes to form a 4 μm-thick pressure-sensitive adhesive layer.
Acrylic polymer solution III containing 100 parts by weight of acrylic polymer III, 5 parts by weight of a cross-linking agent (manufactured by Tosoh Corporation, product name "Coronate L"), and 10 parts by weight of a photopolymerization initiator (manufactured by BASF, product name "Irgacure 127") were added to obtain a pressure-sensitive adhesive (A) for forming a transfer layer. The pressure-sensitive adhesive (A) is applied to the silicone-treated surface of a PET release liner (trade name HY-75Gt, manufactured by Higashiyama Film Co., Ltd., thickness: 75 μm), and then heated at 120° C. for 2 minutes to give a thickness of 5 μm. to form a transfer layer.
On one side of a PET substrate (manufactured by Toray Industries, Inc., trade name “Lumirror S-10”, thickness: 12 μm), the above adhesive layer with a PET release liner is attached, and on the other side, the above adhesive layer with a PET release liner is attached. The transfer layer was laminated to obtain an adhesive sheet consisting of PET release liner/adhesive layer/substrate/transfer layer/PET release liner.
The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 1 shows the results.

[Comparative Example 4]
Acrylic polymer solution III containing 100 parts by weight of acrylic polymer III, 5 parts by weight of a cross-linking agent (manufactured by Tosoh Corporation, product name "Coronate L"), and 10 parts by weight of a photopolymerization initiator (manufactured by BASF, product name "Irgacure 127") were added to obtain a pressure-sensitive adhesive (A) for forming a transfer layer. The pressure-sensitive adhesive (A) is applied to the silicone-treated surface of a PET release liner (trade name HY-75Gt, manufactured by Higashiyama Film Co., Ltd., thickness: 75 μm), and then heated at 120° C. for 2 minutes to give a thickness of 5 μm. to form a transfer layer. The silicone-treated surface of another PET release liner (trade name: MRF38, manufactured by Mitsubishi Plastics, Inc., thickness: 38 μm) was laminated on the transfer layer to obtain an adhesive sheet consisting of PET release liner/transfer layer/PET release liner.
The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 1 shows the results.

[Comparative Example 5]
100 parts by weight of a silicone polymer (manufactured by Dow Toray Industries, trade name "DOWSIL SD 4584 PSA") was applied to the surface of a PET release liner (PET38X1-SS4A, manufactured by Nippa Corporation, thickness: 38 μm) treated with silicone fluoride, and 0.9 parts by weight of mixture A of a catalyst (manufactured by Dow Toray Industries, trade name "DOWSIL SRX212") was applied and then heated at 100° C. for 3 minutes to form an adhesive layer with a thickness of 4 μm.
Acrylic polymer solution III containing 100 parts by weight of acrylic polymer III, 5 parts by weight of a cross-linking agent (manufactured by Tosoh Corporation, product name "Coronate L"), and 10 parts by weight of a photopolymerization initiator (manufactured by BASF, product name "Irgacure 127") were added to obtain a pressure-sensitive adhesive (A) for forming a transfer layer. The pressure-sensitive adhesive (A) is applied to the silicone-treated surface of a PET release liner (trade name HY-75Gt, manufactured by Higashiyama Film Co., Ltd., thickness: 75 μm), and then heated at 120° C. for 2 minutes to give a thickness of 5 μm. to form a transfer layer.
The pressure-sensitive adhesive layer with the PET release liner and the transfer layer with the PET release liner were laminated to obtain a pressure-sensitive adhesive sheet consisting of PET release liner/adhesive layer/transfer layer/PET release liner.
The obtained pressure-sensitive adhesive sheet was subjected to the above evaluation. Table 1 shows the results.

As is clear from Table 1, according to the present invention, the member on the transfer layer can be peeled off in a narrow range by low-power laser light irradiation. Adhesive sheets with an adhesive layer composed of an adhesive other than a silicone-based adhesive (Comparative Examples 1 to 3), an adhesive sheet without an adhesive layer (Comparative Example 4), and an adhesive sheet without a substrate (Comparative Example 5) resulted in poor transferability.

REFERENCE SIGNS LIST 10 Adhesive layer 20 Base material 30 Transfer layer 100 Adhesive sheet

Claims

An adhesive layer, a base material, and a transfer layer are provided in this order,
The pressure-sensitive adhesive layer contains a silicone-based pressure-sensitive adhesive,
adhesive sheet.
The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive layer has a light transmittance of 25% or more at a wavelength of 248 nm.
The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the base material has a light transmittance of 60% or less at a wavelength of 248 nm.
The pressure-sensitive adhesive sheet according to claim 1 or 2, wherein the base material is composed of a polyester-based resin and/or a polyimide-based resin.
The pressure-sensitive adhesive sheet according to any one of claims 1 to 4, wherein the base material has a thickness of 50 µm or less.
The pressure-sensitive adhesive sheet according to any one of claims 1 to 5, wherein the transfer layer is a layer that is cured by irradiation with active energy rays.
The pressure-sensitive adhesive sheet according to any one of claims 1 to 6, wherein the transfer layer has a thickness of 50 µm or less.
The adhesive sheet according to any one of claims 1 to 7, wherein the adhesive force I at 23°C when the adhesive layer of the adhesive sheet is adhered to a glass plate is 2 N/20 mm or more.
The ratio of the adhesive strength I at 23° C. when the adhesive layer of the adhesive sheet is attached to a glass plate to the adhesive strength B at 23° C. after irradiating the transfer layer with ultraviolet rays of 300 mJ/cm 2 is The pressure-sensitive adhesive sheet according to any one of claims 1 to 8, which is 5 or more.
10. Any one of claims 1 to 9, wherein the indentation elastic modulus B of the transfer layer at 23° C. is five times or more the indentation elastic modulus I of the pressure-sensitive adhesive layer at 23° C. after irradiation with ultraviolet rays of 300 mJ/cm 2 . The adhesive sheet described in Crab.
11. Any one of claims 1 to 10, wherein the pressure-sensitive adhesive sheet is used for temporarily fixing a member to a support, and peeling the member from the support by laser light irradiation after transfer and/or processing. Adhesive sheet described.
The pressure-sensitive adhesive sheet according to claim 11, wherein the member is a semiconductor wafer, optical semiconductor element, miniLED or microLED.