WO2018181510A1 - Adhesive sheet - Google Patents

Adhesive sheet Download PDF

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Publication number
WO2018181510A1
WO2018181510A1 PCT/JP2018/012837 JP2018012837W WO2018181510A1 WO 2018181510 A1 WO2018181510 A1 WO 2018181510A1 JP 2018012837 W JP2018012837 W JP 2018012837W WO 2018181510 A1 WO2018181510 A1 WO 2018181510A1
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WO
WIPO (PCT)
Prior art keywords
pressure
sensitive adhesive
adhesive layer
adhesive sheet
meth
Prior art date
Application number
PCT/JP2018/012837
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French (fr)
Japanese (ja)
Inventor
和恵 上村
Original Assignee
リンテック株式会社
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Publication date
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Publication of WO2018181510A1 publication Critical patent/WO2018181510A1/en

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/04—Homopolymers or copolymers of esters
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J5/00—Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • C09J7/38—Pressure-sensitive adhesives [PSA]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/683—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping

Definitions

  • the present invention relates to a pressure-sensitive adhesive sheet that can reduce the adhesive strength at a desired timing and facilitates the peeling of the adherend.
  • an adhesive sheet may be used to temporarily fix a processing target such as an electronic member such as a semiconductor wafer or a display device constituent member (electronic member / optical member).
  • a pressure-sensitive adhesive sheet can reduce the pressure-sensitive adhesive force of the pressure-sensitive adhesive sheet at a desired timing by a method such as applying energy, thereby facilitating the separation of the object to be processed (the adherend).
  • it is subjected to a desired processing step in a state where an adherend such as an electronic member or an optical member is fixed to the adhesive sheet.
  • An object of the present invention is to provide a peeling method between an adhesive sheet and an adherend that can reduce the adhesive force at a desired timing by a novel action mechanism.
  • this invention is a peeling method of the adhesive sheet which peels an adhesive sheet provided with an adhesive layer at least, and the to-be-adhered body stuck on the adhesive surface of the said adhesive layer,
  • the said adhesive layer is The adhesive surface has a recess, and the adherend is attached to the adhesive sheet so that an independent space is formed by the recess of the adhesive layer, and at least the adherend is attached.
  • the pressure-sensitive adhesive sheet is peeled from the adherend by reducing the pressure-sensitive adhesive force of the pressure-sensitive adhesive layer by subjecting the pressure-sensitive adhesive sheet to a decompression process for expanding the gas in the space.
  • a method for peeling an adhesive sheet is provided (Invention 1).
  • the “sheet” in the present invention includes the concept of “tape”.
  • the adhesive force can be reduced at a desired timing by a novel action mechanism of expanding the gas in the space by a decompression process. Peeling of the sheet and the adherend can be facilitated.
  • the pressure reduction treatment is lower than the atmospheric pressure of the environment in which the adhesive sheet is attached to the adherend (Invention 2).
  • the adhesive composition which forms the said adhesive layer may not have active energy ray curability and thermosetting (invention 3), and this invention (invention) In 3), it is preferable that the pressure-sensitive adhesive composition contains a (meth) acrylic acid ester polymer (Invention 4).
  • the adhesive composition which forms the said adhesive layer may have active energy ray curability or thermosetting (invention 5), this invention (invention 5).
  • the active energy ray-curable pressure-sensitive adhesive composition preferably contains a (meth) acrylic acid ester polymer having an active energy ray-curable group in the side chain (Invention 6).
  • the said pressure reduction process may be performed (invention 7), and the said pressure reduction After the treatment, the pressure-sensitive adhesive layer may be cured by irradiating the pressure-sensitive adhesive layer with energy rays (Invention 8).
  • the pressure-sensitive adhesive sheet is preferably used for temporarily fixing the adherend (Invention 9).
  • the adherend is an electronic member or an optical member. It may be a member (Invention 10).
  • 2nd this invention is a manufacturing method of the workpiece obtained by processing a workpiece
  • the pressure-sensitive adhesive layer is placed in a reduced pressure environment and subjected to a pressure reduction treatment to expand the gas in the space, thereby reducing the adhesive strength of the pressure-sensitive adhesive layer, and the processed product and the pressure-sensitive adhesive sheet.
  • the manufacturing method of the workpiece characterized by providing the peeling process which peels is provided (invention 11).
  • the adhesive force can be reduced at a desired timing by a novel action mechanism, and the peeling between the pressure-sensitive adhesive sheet and the adherend is facilitated. be able to.
  • the peeling method of the adhesive sheet which concerns on this embodiment is a method of peeling an adhesive sheet provided with an adhesive layer at least, and the to-be-adhered body stuck on the adhesive surface of the said adhesive layer.
  • the pressure-sensitive adhesive layer has a concave portion on the pressure-sensitive adhesive surface, and the adherend and the pressure-sensitive adhesive sheet are bonded to each other so that an independent space is generated by the concave portion of the pressure-sensitive adhesive layer.
  • at least the pressure-sensitive adhesive sheet to which the adherend is adhered is subjected to a pressure reduction treatment for expanding the gas in the space generated by the recess and the adherend, thereby increasing the adhesive strength of the pressure-sensitive adhesive layer. Decrease and facilitate separation of the adhesive sheet and the adherend.
  • FIG. 1 is a sectional view of an adhesive sheet used in one embodiment of the present invention.
  • the pressure-sensitive adhesive sheet 1 according to the present embodiment includes a pressure-sensitive adhesive layer 2, and the pressure-sensitive adhesive layer 2 has a pressure-sensitive adhesive surface P; a concave portion 3 on a surface that contacts the adherend (the upper surface in FIG. 1). .
  • the adhesive sheet 1 which concerns on this embodiment may be further equipped with the base material 4 in the surface (lower surface in FIG. 1) on the opposite side to the adhesive surface P in an adhesive layer.
  • the pressure-sensitive adhesive sheet 1 according to this embodiment can be used for temporarily fixing an electronic member or an optical member, for example.
  • the case where it is used for temporarily fixing a semiconductor wafer will be mainly described.
  • the pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition that does not have active energy ray curability and thermosetting (hereinafter sometimes referred to as “non-curable” in the present specification). It may be a pressure-sensitive adhesive layer, or may be a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition having active energy ray curability or thermosetting. When the pressure-sensitive adhesive layer is composed of multiple layers, a combination of a non-curable pressure-sensitive adhesive layer and a curable pressure-sensitive adhesive layer may be used.
  • Non-curable pressure-sensitive adhesive compositions examples include acrylic pressure-sensitive adhesive compositions, rubber-based pressure-sensitive adhesive compositions, silicone-based pressure-sensitive adhesive compositions, and urethane-based pressure-sensitive adhesives. Examples thereof include a composition, a polyester-based pressure-sensitive adhesive composition, a polyvinyl ether-based pressure-sensitive adhesive composition, and among them, an acrylic pressure-sensitive adhesive composition is preferable.
  • an acrylic adhesive composition what contains a conventionally well-known (meth) acrylic acid ester polymer can be used. In the present specification, the term “polymer” includes the concept of “copolymer”.
  • the (meth) acrylic acid ester polymer (A) contained in the acrylic pressure-sensitive adhesive composition may be a homopolymer formed from one type of (meth) acrylic acid ester monomer, or a plurality of types of ( The copolymer may be a copolymer formed from a (meth) acrylate monomer, or a copolymer formed from one or more types of (meth) acrylate monomers and monomers other than (meth) acrylate monomers. It may be a polymer. Moreover, a (meth) acrylic acid ester polymer (A) may be used individually by 1 type, and may be used in combination of 2 or more type.
  • Specific types of the compound that becomes the (meth) acrylic acid ester monomer are not particularly limited, and specific examples include (meth) acrylic acid, (meth) acrylic acid ester, and derivatives thereof (acrylonitrile, itaconic acid, and the like).
  • Specific examples of (meth) acrylic acid esters include chain skeletons such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate.
  • (meth) acrylate Having Dorokishi group (meth) acrylate; glycidyl (meth) acrylate, (meth) acrylates having reactive functional groups other than hydroxy group, such as N- methylaminoethyl (meth) acrylate.
  • monomers other than (meth) acrylic acid ester monomers include olefins such as ethylene and norbornene, vinyl acetate, and styrene.
  • the (meth) acrylic acid ester monomer is an alkyl (meth) acrylate, the alkyl group preferably has 1 to 18 carbon atoms.
  • (meth) acrylic acid means both acrylic acid and methacrylic acid. The same applies to other similar terms.
  • the (meth) acrylic acid ester polymer (A) is directly contained in the pressure-sensitive adhesive composition.
  • at least a part thereof may be contained as a crosslinked product by performing a crosslinking reaction with a crosslinking agent.
  • the (meth) acrylic acid ester polymer (A) preferably has a reactive functional group that reacts with the crosslinking agent.
  • the type of the reactive functional group is not particularly limited, and may be appropriately determined based on the type of the crosslinking agent.
  • examples of the reactive functional group of the (meth) acrylic acid ester polymer (A) include a hydroxy group, a carboxyl group, and an amino group. These highly reactive hydroxy groups are preferred.
  • examples of the reactive functional group of the (meth) acrylic acid ester polymer (A) include a carboxyl group, an amino group, an amide group, etc. These highly reactive carboxyl groups are preferred.
  • the method for introducing the reactive functional group into the (meth) acrylic acid ester polymer (A) is not particularly limited.
  • the (meth) acrylic acid ester polymer (A) using a monomer having a reactive functional group is used.
  • a constitutional unit based on a monomer having a reactive functional group is contained in the polymer skeleton.
  • a carboxyl group is introduced into the (meth) acrylic acid ester polymer (A)
  • a (meth) acrylic acid ester polymer (A) is formed using a monomer having a carboxyl group such as (meth) acrylic acid. do it.
  • the (meth) acrylic acid ester polymer (A) When the (meth) acrylic acid ester polymer (A) has a reactive functional group, it accounts for the total mass of the (meth) acrylic acid ester polymer (A) from the viewpoint of making the degree of crosslinking a good range.
  • the proportion of the mass of the structural portion derived from the monomer having a reactive functional group is preferably about 1 to 20% by mass, and more preferably 2 to 10% by mass.
  • the weight average molecular weight (Mw) of the (meth) acrylic acid ester polymer (A) is preferably 10,000 to 2,000,000, and more preferably 100,000 to 1,500,000 from the viewpoint of film forming properties at the time of coating. preferable.
  • the weight average molecular weights of the (meth) acrylic acid ester polymer (A) and the (meth) acrylic acid ester polymers (B1) and (B3) described later are gel permeation chromatography (GPC). It is a value in terms of standard polystyrene measured by the method, and details of the measuring method are shown in the examples described later.
  • the glass transition temperature Tg of the (meth) acrylic acid ester polymer (A) is preferably in the range of ⁇ 70 ° C. to 30 ° C., more preferably in the range of ⁇ 60 ° C. to 20 ° C.
  • the glass transition temperature can be calculated from the Fox equation.
  • the active energy ray-curable pressure-sensitive adhesive composition has an active energy ray-curable compound (B2) and an active energy ray-curable group introduced into the side chain ( It is preferable that at least one of the (meth) acrylic acid ester polymer (B3) is contained.
  • the active energy ray-curable pressure-sensitive adhesive composition is composed of the active energy ray-curable compound (B2) and the (meth) acrylic acid ester polymer (B3) in which an active energy ray-curable group is introduced into the side chain.
  • the active energy ray-curable pressure-sensitive adhesive composition may further contain a (meth) acrylic acid ester polymer (B1) having no active energy ray curability.
  • (1-2-1) (Meth) acrylic acid ester polymer having no active energy ray curability (B1)
  • the adhesive composition which forms the adhesive layer in this embodiment contains the (meth) acrylic acid ester polymer (B1) which does not have active energy ray curability
  • the said (meth) acrylic acid ester polymer (B1) ) May be contained in the pressure-sensitive adhesive composition as it is, or at least a part thereof may be contained as a crosslinked product by performing a crosslinking reaction with a crosslinking agent described later.
  • (meth) acrylic acid ester polymer (B1) the same thing as the (meth) acrylic acid ester polymer (A) mentioned above regarding the non-curable adhesive composition can be used.
  • the active energy ray curable compound (B2) is a compound having an active energy ray curable group and polymerized when irradiated with active energy rays such as ultraviolet rays and electron beams.
  • the active energy ray-curable group possessed by the active energy ray-curable compound (B2) is, for example, a group containing an active energy ray-curable carbon-carbon double bond, and specifically includes a (meth) acryloyl group, vinyl Examples include groups.
  • Examples of the active energy ray-curable compound (B2) are not particularly limited as long as the active energy ray-curable group has the above-mentioned active energy ray-curable group.
  • low molecular weight compounds monofunctional and polyfunctional monomers and Oligomer
  • Specific examples of the low molecular weight active energy ray-curable compound (B2) include trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, pentaerythritol tri (meth) acrylate, and dipentaerythritol monohydroxypenta.
  • the active energy ray-curable compound (B2) usually has a molecular weight of 100 to 30,000, preferably about 300 to 10,000.
  • the content of the active energy ray-curable compound (B2) in the active energy ray-curable adhesive composition and the content ratio with other components are not particularly limited, but the active energy ray-curable adhesive composition is active energy.
  • the active energy ray-curable adhesive composition is active energy.
  • the active energy ray curable compound (B2) is the above (meth) acrylic acid.
  • the amount is preferably 10 to 400 parts by mass, more preferably about 30 to 350 parts by mass with respect to 100 parts by mass of the ester polymer (B1).
  • the active energy ray-curable compound (B2) when it contains the active energy ray-curable compound (B2) and the (meth) acrylic acid ester polymer (B3) in which an active energy ray-curable group is introduced in the side chain described later, )
  • the content of the active energy ray-curable compound (B2) is preferably in the above range with respect to 100 parts by mass of the acrylic ester polymer (B3).
  • the active energy ray-curable pressure-sensitive adhesive composition has the active energy ray-curable compound (B2), the (meth) acrylic acid ester polymer (B1), and the active energy ray-curable group introduced into the side chain.
  • the total amount of the (meth) acrylic acid ester polymer (B1) and the (meth) acrylic acid ester polymer (B3) is 100 parts by mass.
  • the content of the active energy ray-curable compound (B2) is preferably in the above range.
  • (1-2-3) (Meth) acrylic acid ester polymer (B3) having an active energy ray-curable group introduced in the side chain
  • the active energy ray-curable pressure-sensitive adhesive composition in the present embodiment contains a (meth) acrylic acid ester polymer (B3) having an active energy ray-curable group introduced in the side chain, such (meth) acrylic acid ester
  • the polymer (B3) may be contained in the pressure-sensitive adhesive composition as it is, or at least a part thereof may be contained as a crosslinked product by performing a crosslinking reaction with a crosslinking agent described later.
  • the main skeleton of the (meth) acrylic acid ester polymer (B3) in which the active energy ray-curable group is introduced into the side chain is not particularly limited, and is the same as that of the aforementioned (meth) acrylic acid ester polymer (B1). Are illustrated.
  • the active energy ray-curable group introduced into the side chain of the (meth) acrylate polymer (B3) is, for example, a group containing an active energy ray-curable carbon-carbon double bond.
  • a meth) acryloyl group etc. can be illustrated.
  • the active energy ray-curable group may be bonded to the (meth) acrylic acid ester polymer (B3) via an alkylene group, an alkyleneoxy group, a polyalkyleneoxy group, or the like.
  • the (meth) acrylic acid ester polymer (B3) in which an active energy ray-curable group is introduced into the side chain contains, for example, a functional group such as a hydroxy group, a carboxyl group, an amino group, a substituted amino group, and an epoxy group.
  • a (meth) acrylic acid ester polymer is reacted with a substituent that reacts with the functional group and a curable group-containing compound having 1 to 5 active energy ray-curable carbon-carbon double bonds per molecule. Obtained.
  • Such a (meth) acrylic acid ester polymer includes a (meth) acrylic acid ester monomer or a derivative thereof having a functional group such as a hydroxy group, a carboxyl group, an amino group, a substituted amino group, and an epoxy group, and the component (B1) described above. It can be obtained by copolymerizing with a monomer that constitutes.
  • curable group-containing compound examples include (meth) acryloyloxyethyl isocyanate, meta-isopropenyl- ⁇ , ⁇ -dimethylbenzyl isocyanate, (meth) acryloyl isocyanate, allyl isocyanate, glycidyl (meth) acrylate, (meth) Acrylic acid etc. are mentioned, These can be used individually by 1 type or in combination of 2 or more types.
  • the active energy ray hardening group was introduce
  • the kind of the reactive functional group is not particularly limited, and the (meth) acrylic acid ester polymer (B1) described above (and the (meth) acrylic acid ester polymer (A) described above with respect to the non-curable pressure-sensitive adhesive composition) and The same thing can be illustrated.
  • the weight average molecular weight (Mw) of the (meth) acrylic acid ester polymer (B3) having an active energy ray-curable group introduced in the side chain is preferably 100,000 to 2,000,000, and 300,000 to 1,500,000. More preferably.
  • the glass transition temperature (Tg) of the (meth) acrylic acid ester polymer (B3) is preferably in the range of ⁇ 70 to 30 ° C., more preferably in the range of ⁇ 60 to 20 ° C.
  • the glass transition temperature (Tg) of the (meth) acrylic acid ester polymer (B3) refers to that of the (meth) acrylic acid ester polymer before being reacted with the curable group-containing compound.
  • thermosetting pressure-sensitive adhesive composition examples include those containing an epoxy resin, a phenol resin, and the like.
  • the adhesive composition forming the adhesive layer in this embodiment may contain a crosslinking agent capable of reacting with the polymer contained in the above-mentioned adhesive composition.
  • the pressure-sensitive adhesive layer in this embodiment comprises a polymer ((meth) acrylic acid ester polymer (A), (B1), (B3), etc.) contained in the pressure-sensitive adhesive composition and a crosslinking agent. Contains a cross-linked product obtained by a cross-linking reaction.
  • crosslinking agent examples include polyimine compounds such as polyisocyanate compounds, epoxy compounds, metal chelate compounds, and aziridine compounds, melamine resins, urea resins, dialdehydes, methylol polymers, metal alkoxides, metal salts, and the like. 1 type can be used individually or in combination of 2 or more types. Among these, an epoxy compound or a polyisocyanate compound is preferable because it is easy to control the crosslinking reaction.
  • a polyisocyanate compound is a compound having two or more isocyanate groups per molecule.
  • aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like
  • epoxy compound examples include 1,3-bis (N, N′-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine, ethylene glycol diglycidyl ether. 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidylaniline, diglycidylamine and the like.
  • the content of the crosslinking agent in the pressure-sensitive adhesive composition that forms the pressure-sensitive adhesive layer is the polymer contained in the pressure-sensitive adhesive composition (for example, (meth) acrylic acid ester polymers (A), (B1) and (B3)). Is preferably 0.01 to 50 parts by mass, more preferably 0.02 to 10 parts by mass, and more preferably 0.03 to 5 parts by mass with respect to 100 parts by mass of the total amount of Part is more preferable, and 0.08 to 0.5 part by mass is particularly preferable.
  • the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer in the present embodiment contains a crosslinking agent
  • an appropriate crosslinking accelerator may be contained depending on the type of the crosslinking agent.
  • the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer in the present embodiment includes, in addition to the above components, a photopolymerization initiator, a photosensitizer, a crosslinking accelerator, a dye, a pigment, and the like. You may contain various additives, such as a coloring material, a flame retardant, a filler, a heat conductive agent, a tackifier, a plasticizer, and an antistatic agent.
  • the pressure-sensitive adhesive composition when the pressure-sensitive adhesive composition has active energy ray curability that is cured by active energy rays such as ultraviolet rays, the pressure-sensitive adhesive composition preferably contains a photopolymerization initiator.
  • photopolymerization initiators examples include photoinitiators such as benzoin compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, thioxanthone compounds, and peroxide compounds, and photosensitizers such as amines and quinones.
  • 1-hydroxycyclohexyl phenyl ketone benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, ⁇ -chloranthraquinone 2,4,6-trimethylbenzoyldiphenylphosphine oxide and the like, and these can be used alone or in combination of two or more.
  • ultraviolet rays When ultraviolet rays are used as energy rays, the irradiation time and irradiation amount can be reduced by blending a photopolymerization initiator.
  • the adhesive layer 2 has the concave part 3 in the adhesive surface P. As shown in FIG. As will be described later, in the pressure-sensitive adhesive sheet peeling method according to the present embodiment, the adherend is adhered to the pressure-sensitive adhesive sheet 1 (the pressure-sensitive adhesive surface P) so that a space is generated by the concave portion 3 of the pressure-sensitive adhesive layer 2.
  • the pressure-sensitive adhesive layer 2 preferably has an independent recess 3.
  • that the concave portion 3 is independent means that the entire outer edge of the concave portion 3 is surrounded by a flat surface portion (sometimes referred to as a non-recessed portion) constituting the adhesive surface P, in other words, the concave portion 3. Means that it does not communicate with the end of the pressure-sensitive adhesive sheet 1.
  • the pressure-sensitive adhesive layer 2 has the independent recess 3, it becomes easy to make the space generated by the adherend and the recess 3 of the pressure-sensitive adhesive layer 2 an independent space.
  • the pressure-sensitive adhesive layer 2 preferably has a plurality of recesses 3. Since the pressure-sensitive adhesive layer 2 has a plurality of recesses 3, it is easy to make the space generated by the adherend and the recesses 3 of the pressure-sensitive adhesive layer 2 independent spaces. Furthermore, it is particularly preferable that the pressure-sensitive adhesive layer 2 has a plurality of independent recesses 3. In addition, when the adhesive layer 2 has two or more recessed parts, all the recessed parts 3 do not necessarily need to be independent, and the one part may be connected with the edge part of the adhesive sheet 1. FIG.
  • each recess 3 may have the same shape or may have a different shape.
  • the concave portion 3 has a circular shape (including an elliptical shape or an oval shape) (FIG. 2A), a rectangular shape when the shape of the concave portion 3 on the adhesive surface P is viewed in plan view.
  • a convex polygonal shape (the same (b)
  • a concave polygonal shape such as a star shape (the same (c)), etc.
  • these are combined and arranged in a predetermined pattern (the same (d), (e)) It may also be an irregular shape (same (f)).
  • a plurality of rectangular concave portions 31 are arranged in parallel in the long side direction to form one repeating unit U, and the length of the rectangular concave portion 31 constituting the repeating unit U is long.
  • a plurality of repeating units U are repeatedly arranged vertically and horizontally so that the side directions are alternated.
  • a plurality of rectangular recesses 32 and two right-angled triangular recesses 33 form one repeating unit U ′, and the repeating units U ′ are arranged vertically and horizontally. Yes.
  • one side forming a right angle in the right triangular recess 33 is parallel to the long side of the rectangular recess 32, and the oblique side of the right triangular recess 33 faces the short side of the rectangular recess 32.
  • the rectangular recess 32 and the right triangle recess 33 are arranged.
  • the plurality of rectangular recesses 32 have long sides that become longer as they move away from the right triangle recess 33.
  • the recess 34 has an irregular shape, and the size (length, width, depth, etc.) of the recess 34 is not limited to a specific value. Further, the width and direction of one concave portion 34 are continuously or intermittently changed, and may have a branched shape.
  • the embossed pattern may be a polygon such as a regular triangle, a right triangle, a square, a rectangle, a rhombus, etc.
  • a star-shaped polygon such as a pentagram or a hexagon; a circle; an ellipse; a regular repetitive pattern provided with a plurality of shapes such as a polygon having a curved shape such as a fan shape or a heart shape.
  • emboss pattern is not particularly limited as long as it can form a recess 3 that creates an independent space with the adherend. However, it is preferable that the emboss pattern can form an independent recess 3. Those not communicating with the portion are preferred, and it is particularly preferred that a plurality of independent recesses 3 can be formed.
  • the cross-sectional shape of the recess 3 is semicircular (FIG. 3A), quadrangular (same (b)), trapezoid (same (c)), triangular (same (d)). ) And the like.
  • the recessed part 3 expands the gas in the space produced by the recessed part 3 and a to-be-adhered body by performing a pressure reduction process, and a viewpoint which reduces the adhesive force of the adhesive layer 2 effectively. Therefore, it is preferable that the expanded gas has a shape that tends to concentrate locally.
  • the shape of the concave portion 3 on the adhesive surface P is preferably a convex polygonal shape, a concave polygonal shape, or an irregular shape.
  • the height of the recess 3 is preferably 2 ⁇ m or more and not more than the thickness of the pressure-sensitive adhesive layer 2, particularly preferably 5 ⁇ m or more and not more than the thickness of the pressure-sensitive adhesive layer 2, and 10 ⁇ m or more and the thickness of the pressure-sensitive adhesive layer 2 or less. It is more preferable that the thickness is 20 ⁇ m or more and not more than the thickness of the pressure-sensitive adhesive layer 2.
  • the lower limit of the ratio of the recessed area to the total area of the adhesive surface P (hereinafter also referred to as recessed area ratio) is preferably 3% or more, particularly preferably 10% or more, and 25% or more. More preferably. Further, the upper limit value of the recessed area ratio is preferably 90% or less, particularly preferably 75% or less, and further preferably 60% or less.
  • the area ratio of the recess is 3% or more, a sufficient space is generated between the recess 3 and the adherend. Therefore, when decompression processing is performed, the pressure due to gas expansion becomes large in the space, and the adhesive strength Can be effectively reduced.
  • the recess area ratio is 90% or less, a sufficient contact area with the adherend can be ensured, so that a desired adhesive force can be secured.
  • the concave area ratio is obtained by obtaining an image of the adhesive surface P at a photographing magnification of 20 to 100 times using a digital microscope and imaging the concave surface when the adhesive surface P is viewed in plan. It can be measured by performing (binarization processing) and automatically measuring the total area of the recessed areas. Specifically, a value calculated based on the following formula in a predetermined region D arbitrarily selected on the adhesive surface P can be regarded as a recess area ratio. A detailed measurement method will be described in Examples described later.
  • Examples of the method for forming the recess 3 include embossing in which an emboss pattern is transferred to an adhesive layer.
  • the convex portion in the emboss pattern is transferred to the pressure-sensitive adhesive layer and becomes the concave portion 3 on the pressure-sensitive adhesive surface.
  • the ratio of the convex area to the total area of the surface (embossed surface) on which the embossed pattern is formed (hereinafter also referred to as convex area ratio) is preferably 30% or more as a lower limit, and 50%. It is particularly preferable that the ratio is 70% or more.
  • the upper limit value of the convex area ratio is preferably 98% or less, particularly preferably 95% or less, and further preferably 90% or less.
  • the convex area ratio on the embossed surface does not necessarily coincide with the concave area ratio of the adhesive surface P when embossing is performed on a relatively soft adhesive layer. However, even in such a case, when the convex area ratio on the embossed surface is in the above range, it is easy to keep the concave area ratio in the above-described preferable range on the adhesive surface P to which the embossed pattern is transferred. Become.
  • the convex area ratio on the embossed surface is obtained by obtaining an image of the embossed surface when the embossed surface is viewed in plan using a digital microscope, a laser microscope, or an electron microscope with a shooting magnification of 20 to 1000 times. Then, image processing (binarization processing) is performed on the image, and the total value of the convex area can be measured by automatic area measurement. Specifically, a value calculated based on the following formula in a predetermined region T arbitrarily selected on the embossed surface can be regarded as a convex area ratio. A detailed measurement method will be described in Examples described later.
  • a pattern printing method may be used so that the recesses 3 are formed.
  • the recesses 3 are formed by laser thermal processing for irradiating a laser to the adhesive layer. May be.
  • the method described in International Publication No. 2015/152347 can also be illustrated as a method of forming the recess 3 having an irregular shape.
  • a coating film made of a composition having a high content of fine particles and a small content of resin and a coating film made of a composition containing a resin as a main component are separately formed. The method of drying a coating film simultaneously is mentioned. According to this method, the shrinkage stress difference caused by the fine particles is generated inside the coating film, causing cracking of the coating film, and the peripheral resin flows into the cracking of the coating film, thereby forming the recess 3. it is conceivable that.
  • the thickness of the pressure-sensitive adhesive layer in this embodiment is preferably 5 to 100 ⁇ m, particularly preferably 10 to 50 ⁇ m, and 15 to 30 ⁇ m. More preferably. It is preferable that the pressure-sensitive adhesive layer has a thickness of 5 ⁇ m or more because more space can be secured during decompression. It is preferable for the thickness of the pressure-sensitive adhesive layer to be 100 ⁇ m or less because the film thickness accuracy during application can be ensured.
  • the adhesive strength of the adhesive sheet is preferably 0.5 to 50 N / 25 mm, more preferably 2 to 40 N / 25 mm, and particularly preferably 5 to 30 N / 25 mm. .
  • the adherend can be reliably fixed. For example, it is very useful for temporarily fixing the adherend in the processing step of the adherend.
  • the adhesive force here does not perform the pressure reduction process mentioned later (When the adhesive composition has active energy ray curable property or thermosetting property, irradiation and heating of the active energy ray are not further performed).
  • a silicon mirror wafer be a to-be-adhered body, stick an adhesive sheet on the mirror surface, and let it be the adhesive force (mN / 25mm) measured by 180 degree peeling method according to JISZ0237: 2009.
  • the adhesive strength reduction rate of the adhesive sheet is preferably 10% or more, more preferably 20% or more, and particularly preferably 30% or more. When the adhesive strength of the adhesive sheet is within the above range, in this embodiment, the adhesive sheet and the adherend are more easily separated.
  • the adhesive force decreasing rate here is before performing the pressure reduction process mentioned later (When the adhesive composition has active energy ray curable or thermosetting, after irradiation or heating of active energy rays)
  • the adhesive strength is measured as described above, and is calculated by the following formula based on the obtained value.
  • Adhesive strength reduction rate (%) (adhesive strength before decompression ⁇ adhesive strength after decompression) / (adhesive strength before decompression) ⁇ 100
  • the irradiation or heating of the active energy ray when the pressure-sensitive adhesive composition has active energy ray curable property or thermosetting property may be before or after the decompression treatment, Even in this case, the adhesive strength reduction rate is calculated by the above formula.
  • the lower limit value of the stress relaxation rate of the pressure-sensitive adhesive layer is preferably 40% or more, particularly preferably 50% or more, and 55% or more. Is more preferable.
  • the upper limit of the stress relaxation rate of the pressure-sensitive adhesive layer is preferably 90% or less, particularly preferably 85% or less, and further preferably 80% or less.
  • the stress relaxation rate of an adhesive layer here is not performing the pressure reduction process mentioned later (When an adhesive composition has active energy ray sclerosis
  • the pressure-sensitive adhesive layer is the stress relaxation rate after being stretched by 10% in a tensile test and held for 300 seconds. Specifically, the tensile test was performed at a speed of 200 mm / min with an adhesive formed into a thickness of 50 ⁇ m, a width of 15 mm, and a length of 120 mm (of which the measurement range is 100 mm) in an environment of 23 ° C. and 50% RH. And 10% elongation.
  • the lower limit of the breaking elongation of the pressure-sensitive adhesive layer is preferably 110% or more, particularly preferably 120% or more, and preferably 130% or more. Is more preferable.
  • the upper limit of the elongation at break of the pressure-sensitive adhesive layer is preferably 300% or less, particularly preferably 200% or less, and further preferably 150% or less.
  • the pressure-sensitive adhesive layer was measured as a single pressure-sensitive adhesive layer without a substrate or the like. Specifically, the pressure-sensitive adhesive layer was formed into a thickness of 50 ⁇ m, a width of 15 mm, and a length of 120 mm (of which the measurement range was 100 mm) The pressure-sensitive adhesive is stretched at a speed of 200 mm / min in an environment of 23 ° C. and 50% RH.
  • the lower limit of the gel fraction of the pressure-sensitive adhesive layer is preferably 2% or more, particularly preferably 4% or more, and 6% or more. Is more preferable.
  • the upper limit of the gel fraction of the pressure-sensitive adhesive layer is preferably 90% or less, particularly preferably 40% or less, and further preferably 15% or less.
  • the stability of the pressure-sensitive adhesive sheet can be ensured by the reaction between the pressure-sensitive adhesives due to crosslinking.
  • the upper limit of the gel fraction of the pressure-sensitive adhesive layer is 90% or less, it is easy to impart tack to the pressure-sensitive adhesive sheet, and good temporary fixability can be obtained.
  • the gel fraction of an adhesive layer here is not performing the pressure reduction process mentioned later (When an adhesive composition has active energy ray sclerosis
  • the pressure-sensitive adhesive sheet according to this embodiment may include a base material in addition to the pressure-sensitive adhesive layer.
  • the base material is not particularly limited as long as the pressure-sensitive adhesive sheet can appropriately function in a desired process such as an adherend processing process.
  • a paper base material, a resin film or sheet, a paper base The base material etc. which laminated the material with resin are mentioned, According to the use of the adhesive sheet of 1 aspect of this embodiment, it can select suitably.
  • the film is composed of a film mainly composed of a resin-based material because of its advantage for the decompression effect.
  • Such films include ethylene-copolymer films such as ethylene-vinyl acetate copolymer films, ethylene- (meth) acrylic acid copolymer films, and ethylene- (meth) acrylic acid ester copolymer films; low density Polyethylene films such as polyethylene (LDPE) film, linear low density polyethylene (LLDPE) film, high density polyethylene (HDPE) film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, ethylene-norbornene copolymer film, Polyolefin film such as norbornene resin film; Polyvinyl chloride film such as polyvinyl chloride film and vinyl chloride copolymer film; Polyethylene terephthalate film, Polybutylene tele Polyester film of tallate films; polyurethane film; polyimide film; polystyrene films; polycarbonate films; and fluorine resin film. Further, modified films such as these crosslinked films and ionomer films are also used
  • the film constituting the base material preferably includes at least one of an ethylene copolymer film and a polyolefin film. It is easy to control the mechanical characteristics of an ethylene copolymer film in a wide range by changing the copolymerization ratio. For this reason, the base material provided with the ethylene-based copolymer film easily satisfies the mechanical properties required as the base material of the pressure-sensitive adhesive sheet according to this embodiment. Moreover, since the ethylene copolymer film has relatively high adhesion to the pressure-sensitive adhesive layer, peeling at the interface between the base material and the pressure-sensitive adhesive layer hardly occurs when used as a pressure-sensitive adhesive sheet.
  • the base material used in the present embodiment contains various additives such as pigments, dyes, flame retardants, plasticizers, antistatic agents, lubricants, fillers, etc., in the film mainly composed of the above-mentioned resin-based material. May be.
  • the pigment include titanium dioxide and carbon black.
  • the filler include organic materials such as melamine resin, inorganic materials such as fumed silica, and metal materials such as nickel particles. The content of such an additive is not particularly limited, but should be within a range where the substrate exhibits a desired function and does not lose smoothness and flexibility.
  • the substrate is preferably permeable to ultraviolet rays.
  • the base material has the transparency of an electron beam.
  • the adherend has energy ray permeability and the energy beam is irradiated from the adherend side, the substrate does not need to have energy ray permeability.
  • a component having one or more kinds selected from the group consisting of a carboxyl group and its ions and salts is provided on the surface of the substrate on the side of the pressure-sensitive adhesive layer (hereinafter also referred to as “substrate-coated surface”). Is preferably present.
  • substrate-coated surface a component having one or more kinds selected from the group consisting of a carboxyl group and its ions and salts.
  • the base material itself is an ethylene- (meth) acrylic acid copolymer film, an ionomer resin film, etc., and the resin constituting the base material is selected from the group consisting of carboxyl groups, ions and salts thereof. Or you may have 2 or more types.
  • the substrate is, for example, a polyolefin film, and the substrate-adhered surface side is subjected to corona treatment or a primer layer is provided. May be.
  • Various coating films may be provided on the surface of the substrate opposite to the substrate deposition surface.
  • the thickness of the substrate is not limited as long as the pressure-sensitive adhesive sheet can function properly in a desired process, but it is preferably 5 to 1000 ⁇ m, more preferably 10 to 500 ⁇ m, and still more preferably 12 to 12 from the viewpoint of handleability and economy.
  • the thickness is 250 ⁇ m, more preferably 15 to 150 ⁇ m.
  • the release sheet is laminated on the adhesive surface of the adhesive layer for the purpose of protecting the adhesive layer until the adhesive layer is applied to the adherend. It may be.
  • the configuration of the release sheet is arbitrary, and examples include a release film of a plastic film with a release agent.
  • Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene.
  • the release agent silicone-based, fluorine-based, long-chain alkyl-based, and the like can be used, and among these, a silicone-based material that is inexpensive and provides stable performance is preferable.
  • the thickness of the release sheet is not particularly limited, but is usually about 20 to 250 ⁇ m.
  • a release sheet may be a release sheet on which an emboss pattern for forming a recess is formed, and the release surface is flat, and the adhesive layer is protected after the recess is formed. It may be a release sheet laminated on the substrate.
  • the manufacturing method of an adhesive sheet is a method which can form the adhesive layer formed from the above-mentioned adhesive composition, and can form a recessed part in the adhesive surface of an adhesive layer. If there is, the detailed method is not particularly limited. As an example, first, a sheet on which an emboss pattern corresponding to the concave portion is formed is prepared, and a release sheet on which the emboss pattern is formed is obtained by performing a release process on the surface of the sheet.
  • a coating composition containing the pressure-sensitive adhesive composition described above and, if desired, further containing a solvent or a dispersion medium is prepared, and on the release-treated surface of the release sheet having an emboss pattern obtained as described above, a die coater Applying the coating composition by a curtain coater, spray coater, slit coater, knife coater, etc. to form a coating film, and drying the coating film forms a laminate composed of an adhesive layer and a release sheet can do.
  • a surface of the pressure-sensitive adhesive layer of the laminate that is opposite to the surface on the side of the release sheet may be attached to a substrate to obtain a laminate of the pressure-sensitive adhesive sheet and the release sheet.
  • the release sheet in this laminate may be peeled off as a process material, or the adhesive layer may be protected until being attached to an adherend such as an electronic member or an optical member.
  • the properties of the coating composition are not particularly limited as long as it can be applied, and may contain a component for forming the pressure-sensitive adhesive layer as a solute or a dispersoid. There is also a case.
  • the coating composition contains a crosslinking agent, (meth) acrylic acid in the coating film can be obtained by changing the drying conditions (temperature, time, etc.) or by separately providing a heat treatment. What is necessary is just to advance the crosslinking reaction of ester polymer (A), (B1) or (B3), and a crosslinking agent, and to form a crosslinked structure in a desired presence density in an adhesive layer.
  • crosslinking of the pressure-sensitive adhesive refers to a reaction performed before sticking the pressure-sensitive adhesive sheet to the adherend, and before sticking to the adherend is, for example, the pressure-sensitive adhesive described above. A step of forming a layer may be mentioned. Therefore, “crosslinking” of the pressure-sensitive adhesive is clearly distinguished from “curing” described later.
  • the pressure-sensitive adhesive sheet may be performed by laser thermal processing by laser irradiation instead of embossing.
  • a laser is irradiated from the pressure-sensitive adhesive side of the pressure-sensitive adhesive layer to form a recess.
  • the laser used for laser thermal processing include carbon dioxide (CO 2 ) laser, TEA-CO 2 laser, YAG laser, UV-YAG laser, YVO 4 laser, YLF laser, etc. From the viewpoint of cost and the like, a carbon dioxide laser is preferable.
  • burst processing burst mode
  • laser light is continuously irradiated to one place until one through-hole is formed, and laser light is sequentially irradiated to a plurality of places.
  • burst processing burst mode
  • the former is superior in terms of thermal efficiency
  • the latter is superior in terms of reducing the thermal effect on the workpiece.
  • Thermal processing may be performed in any mode.
  • Examples of the workpiece W to be subjected to the peeling method according to this embodiment include electronic members such as a semiconductor wafer, a semiconductor package, a multilayer substrate, a ceramic green sheet laminate, a batch sealing module; a liquid crystal display member, and an organic EL display member. And optical members such as an optical filter, a polarizing plate, and a retardation plate.
  • the attachment of the workpiece W and the pressure-sensitive adhesive sheet 1 may be performed under atmospheric pressure, or may be performed in a chamber in which the atmospheric pressure is controlled by the pressure control device 10 described later.
  • the atmospheric pressure in which the sticking process is performed or the atmospheric pressure in the chamber corresponds to the pressure of the gas in the space C in the subsequent process, and after performing the sticking process after appropriately adjusting the atmospheric pressure, It becomes easy to control the amount of gas expansion in the decompression process.
  • work W stuck on the adhesive sheet 1 by the sticking process can be attached
  • processing steps include a back grinding process, a circuit forming process, a dicing process, a die sort process, and the like if the work W is a semiconductor wafer, and a laminating process and a transfer process if the work W is a display device component. Etc.
  • the workpiece W is processed into a workpiece W ′.
  • the adhesive sheet 1 is peeled from the workpiece W as described later after the processing step of the workpiece W, it can be said that it is used for temporarily fixing the workpiece W during the processing step.
  • At least the space C is given a pressure in a direction in which it expands in a direction along the vertical direction (the normal direction of the adhesive surface P of the adhesive layer 2).
  • the lateral direction applied to one space C (the pressure-sensitive adhesive surface P in the pressure-sensitive adhesive layer 2).
  • Force in the vertical direction of the space C the pressure in the vertical direction remains without being canceled, and the pressure in the space C adjacent to the space C cancels the pressure in the vertical direction. Is more preferable because it becomes more prominent.
  • the pressure reduction treatment is preferably lower than the atmospheric pressure of the pasting environment, more preferably lower so that the atmospheric pressure in the chamber has a difference of 10 kPa or more than the atmospheric pressure of the pasting environment.
  • the difference is more preferably 30 kPa or more, still more preferably 50 kPa or more, further preferably 80 kPa or more, and particularly preferably 90 kPa or more.
  • the lower limit value of the pressure in the chamber is not particularly limited, but is usually 10 ⁇ 7 Pa or more, preferably 10 ⁇ 5 Pa or more, more preferably 10 ⁇ 1 Pa or more, and even more, from a technical viewpoint.
  • it is 10 Pa or more, More preferably, it is 100 Pa or more, Especially preferably, it is 1000 Pa or more.
  • the adhesive is applied from that location.
  • the agent layer 2 is partially or entirely peeled from the workpiece W ′ (FIG. 4E). Since the pressure-sensitive adhesive layer 2 has a plurality of recesses 3, a plurality of spaces C are formed, and therefore, the number of expanding portions increases, resulting in an increase in the number of locations that cause peeling.
  • the pressure-sensitive adhesive layer 2 may be hard or soft. When the pressure-sensitive adhesive layer 2 is relatively hard, as shown in FIG.
  • the pressure-sensitive adhesive layer 2 and the workpiece W ′ The peeling of the interface proceeds from the space C side. This is because the pressure due to the expansion of the gas is an interface between the pressure-sensitive adhesive layer 2 and the workpiece W ′, which is a relatively fragile portion of the inner wall of the space C constituted by the pressure-sensitive adhesive layer 2 and the workpiece W ′. This is thought to be easier to concentrate on.
  • the pressure-sensitive adhesive layer 2 is relatively soft, after the space C and the pressure-sensitive adhesive layer 2 are deformed in the vertical direction, the pressure-sensitive adhesive layer 2 and the workpiece W ′ are formed as shown in FIG. Peel off. In this way, the adhesive strength of the pressure-sensitive adhesive layer 2 to the workpiece W ′ is reduced.
  • the adhesive sheet 1 and the workpiece W ′ can be easily peeled off.
  • the pressure-sensitive adhesive sheet 1 and the workpiece W ′ can be peeled as they are in the state shown in FIG. 4E.
  • the pressure-sensitive adhesive sheet 1 is placed in the chamber so that the workpiece W ′ is on the upper side of the pressure-sensitive adhesive sheet 1.
  • the pressure-sensitive adhesive sheet 1 and the workpiece W ′ are peeled off by the weight of the workpiece W ′. You can also.
  • the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer 2 has active energy ray curable or thermosetting property
  • the active energy ray irradiation or after the above-described processing step and before or after the decompression treatment It is preferable to cure the pressure-sensitive adhesive layer 2 by heating.
  • the pressure-sensitive adhesive layer 2 is cured before the pressure reduction treatment, the pressure-sensitive adhesive layer 2 is relatively hard at the stage of the pressure reduction treatment. Peeling of the interface between the pressure-sensitive adhesive layer 2 and the workpiece W ′ progresses from the space C side almost without causing the pressure-sensitive adhesive layer 2 and the workpiece W ′ and the adhesive force to be reduced.
  • the pressure-sensitive adhesive layer 2 is cured after the pressure reduction treatment, the space C and the pressure-sensitive adhesive layer 2 are deformed (FIG. 4D) because the pressure-sensitive adhesive layer 2 is relatively soft at the stage of the pressure reduction treatment. Thereafter, the pressure-sensitive adhesive layer 2 can be cured to further reduce the adhesive force, and the pressure-sensitive adhesive layer 2 and the workpiece W ′ can be easily separated from each other.
  • “curing” of the pressure-sensitive adhesive refers to a reaction performed after the pressure-sensitive adhesive sheet 1 is adhered to an adherend (work W, workpiece W ′). Therefore, for example, it is clearly distinguished from the above-mentioned “crosslinking” of the pressure-sensitive adhesive.
  • examples of the active energy ray for curing the pressure-sensitive adhesive composition include ionizing radiation, that is, ultraviolet rays, X-rays, and electron beams. Among these, ultraviolet rays that are relatively easy to introduce irradiation equipment are preferable.
  • near ultraviolet rays including ultraviolet rays having a wavelength of about 200 to 380 nm may be used for ease of handling.
  • the amount of light may be appropriately selected according to the type of active energy ray-curable group possessed by the active energy ray-curable pressure-sensitive adhesive composition and the thickness of the pressure-sensitive adhesive layer 2, and is usually about 50 to 1500 mJ / cm 2 . 200 to 1000 mJ / cm 2 is preferable, and 300 to 800 mJ / cm 2 is more preferable.
  • the ultraviolet illumination is usually 50 ⁇ 1500mW / cm 2 or so, preferably 200 ⁇ 1000mW / cm 2, more preferably 300 ⁇ 800mW / cm 2.
  • the ultraviolet light source is not particularly limited, and for example, an electrodeless lamp, a high-pressure mercury lamp, a metal halide lamp, a UV-LED, or the like is used.
  • the acceleration voltage is appropriately selected according to the type of active energy ray-curable group possessed by the active energy ray-curable adhesive composition and the thickness of the adhesive layer 2. Usually, the acceleration voltage is preferably about 10 to 1000 kV.
  • the irradiation dose may be set within a range where the active energy ray-curable pressure-sensitive adhesive composition is appropriately cured, and is usually selected within a range of 10 to 1000 krad.
  • the electron beam source is not particularly limited.
  • various electron beam accelerators such as a cockcroft Walton type, a bandegraph type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type may be used. it can.
  • these active energy rays may be irradiated from the surface opposite to the pressure-sensitive adhesive surface P (the surface on which the workpiece W ′ is adhered) in the pressure-sensitive adhesive sheet 1. preferable.
  • the pressure-sensitive adhesive composition has thermosetting properties
  • a heating means for curing the pressure-sensitive adhesive composition for example, an appropriate means such as a hot plate, a hot air dryer, or a near infrared lamp can be adopted. It can.
  • the heating conditions are appropriately set depending on the heating temperature required for the thermosetting of the pressure-sensitive adhesive layer 2, the desired peelability, the heat resistance of the workpiece W and the workpiece W ', the heating means, and the like.
  • As general heating conditions for example, when a hot plate is used, a temperature of 80 to 250 ° C., a heating time of 5 seconds to 60 seconds, and the like are exemplified.
  • the pressure-sensitive adhesive treatment of the pressure-sensitive adhesive sheet 1 to the adherend is reduced by a decompression process that forms a space C in the space C and expands the gas in the space C.
  • the adhesive force can be reduced at a desired timing by a novel mechanism of expanding the gas by the decompression process, thereby facilitating the peeling between the adhesive sheet and the adherend. Can do.
  • the adhesive force of the pressure-sensitive adhesive layer 2 is reduced using only active energy ray curable or thermosetting, the selection of materials is limited because the curing reaction (that is, chemical reaction) is sufficiently advanced. End up.
  • the adhesive force can be reduced by the expansion of the gas due to the decompression process, so that the active energy ray curable property or thermosetting property is not used at all or only partially used. Therefore, the freedom degree of the material which comprises the adhesive layer 2 can be made large.
  • the adhesive strength of the adhesive layer 2 decreases.
  • thermosetting property is not used at all or only partially used. Even if a heating process is included in the workpiece, the workpiece W can be sufficiently temporarily fixed.
  • another layer may be interposed between the base material 4 and the pressure-sensitive adhesive layer 2 in the pressure-sensitive adhesive sheet 1.
  • the pressure-sensitive adhesive sheet may be a double-sided pressure-sensitive adhesive sheet comprising only a pressure-sensitive adhesive layer without a base material.
  • a method of peeling a double-sided pressure-sensitive adhesive sheet having a first pressure-sensitive adhesive surface and a second pressure-sensitive adhesive surface, and a first adherend adhered to the first pressure-sensitive adhesive surface can do.
  • a second adherend may be attached to the second adhesive surface.
  • the first adhesive surface has a recess, and the first adherend is adhered to the adhesive layer so that an independent space is created by the recess.
  • the gas in the space expands, and the adhesive force of the double-sided pressure-sensitive adhesive sheet on the first adherend is increased.
  • the first adherend and the pressure-sensitive adhesive sheet can be peeled off.
  • An embossed film (1) is obtained by embossing a polyethylene terephthalate film (manufactured by Toray Industries, Inc., product name “Lumirror”, thickness 75 ⁇ m) to the pattern of FIG. It was.
  • a release agent on the embossed surface of the embossed film (1) a release agent having the same composition as the release agent of the release sheet (product name “SP-PET381130”, manufactured by Lintec Corporation) is 0.1 ⁇ m in thickness after drying.
  • the release sheet (1) having an embossed pattern on the surface was prepared by coating with a Meyer bar so that
  • polystyrene equivalent weight average molecular weight is a standard polystyrene equivalent value measured (GPC measurement) under the following conditions using a gel permeation chromatograph (manufactured by Tosoh Corporation, product name “HLC-8020”).
  • An embossed film (2) was obtained by embossing a polyethylene terephthalate film (manufactured by Toray Industries, Inc., product name “Lumirror”, thickness 75 ⁇ m) so as to have the pattern of FIG.
  • a release agent having the same composition as the release agent of the release sheet (product name “SP-PET381130”, manufactured by Lintec Corporation) is 0.1 ⁇ m in thickness after drying.
  • the release sheet (2) having an embossed pattern on the surface was prepared by applying with a Meyer bar so as to become and drying at 130 ° C. for 30 seconds.
  • a pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the obtained release sheet (2) was used.
  • Example 3 An embossed film (3) was obtained by embossing a polyethylene terephthalate film (manufactured by Toray Industries, Inc., product name “Lumirror”, thickness 75 ⁇ m) so as to have the pattern of FIG.
  • a release agent having the same composition as the release agent of the release sheet (product name “SP-PET381130”, manufactured by Lintec Corporation) is 0.1 ⁇ m in thickness after drying.
  • the release sheet (3) having an embossed pattern on the surface was prepared by coating with a Meyer bar so that A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the obtained release sheet (3) was used.
  • the release sheet (1) is 4 mm long x 5 mm wide
  • the release sheet (2) is 8 mm long x 10 mm wide
  • the release sheet (3) 2 mm long ⁇ 2.5 mm wide were selected.
  • the photographing conditions of the digital microscope are as follows.
  • Convex part area ratio [convex part area in region T / total area of region T] ⁇ 100
  • FIGS. 5B, 6B, and 7B The binarized images obtained for the embossed surfaces of the release sheets of Examples 1 to 3 are shown in FIGS. 5B, 6B, and 7B, respectively.
  • the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet obtained in each example was bonded to a glass plate (Corning Co., Ltd., product name “Eagle XG”), and the adhesive surface was passed through the glass plate with a digital microscope (magnification 20 to 50 times). Using, an arbitrarily selected range on the adhesive surface was photographed vertically from the upper surface, and an image was acquired. The obtained images are shown in FIGS. 8 (a), 9 (a), and 10 (a). In this case, more specifically, the focal point was sequentially moved from above the portion that was visually determined to be a non-recessed portion from the vertical direction, and the first focused portion was photographed as a non-recessed portion. Then, in the obtained connected image, a region D surrounded by a rectangle 6 mm long ⁇ 8 mm wide is arbitrarily selected as one region, and this is defined as an “image of region D”.
  • the photographing conditions of the digital microscope are as follows.
  • the ultraviolet irradiation conditions are an illuminance of 700 mW / cm 2 and a light amount of 700 mJ / cm 2 in a wavelength range of 200 to 380 nm.
  • the illuminance and light amount are determined by an illuminance / light meter (product name “UV Power Pack II” manufactured by EIT). Used to measure illuminance and light intensity.
  • Adhesive strength reduction rate (%) (Adhesive strength after UV irradiation ⁇ Adhesive strength after reduced pressure) / (Adhesive strength after UV irradiation) ⁇ 100
  • ⁇ Stress relaxation rate> the embossed film was changed to a heavy release sheet (manufactured by Lintec Co., Ltd., product name “SP-PET 382050”, thickness 38 ⁇ m, polyethylene terephthalate film coated with a silicone release agent), and the substrate was lightly released. Change to a sheet (manufactured by Lintec Corporation, product name “SP-PET 381031”, thickness 38 ⁇ m, polyethylene terephthalate film coated with silicone release agent), so that the thickness of the adhesive layer after drying is 50 ⁇ m A substrate-less double-sided pressure-sensitive adhesive sheet sandwiched between two release sheets was prepared in the same manner as described in the Examples except that it was applied.
  • the substrate-less double-sided pressure-sensitive adhesive sheet is allowed to stand for 2 weeks in an atmosphere of 23 ° C. and 50% RH, and is irradiated with ultraviolet rays using an irradiation ultraviolet irradiation device (product name “Light Hammer 10 MARK II”, electrodeless lamp) manufactured by Heraeus. Was irradiated.
  • the ultraviolet irradiation conditions are an illuminance of 700 mW / cm 2 and a light amount of 700 mJ / cm 2 in a wavelength range of 200 to 380 nm.
  • the illuminance and light amount are determined by an illuminance / light meter (product name “UV Power Pack II” manufactured by EIT). Used to measure illuminance and light intensity.
  • a 15 mm wide ⁇ 120 mm long sample is cut out from the pressure sensitive adhesive sheet in which a plurality of the pressure sensitive adhesive layers are laminated, and the release sheet laminated on the outermost layer of the laminate is peeled off so that the sample measurement range becomes 15 mm wide ⁇ 100 mm long.
  • the sample was set in a universal tensile testing machine (manufactured by Shimadzu Corporation, Autograph AG-10kNIS). Then, in an environment of 23 ° C. and 50% RH (relative humidity), the sample was stretched at a pulling rate of 200 mm / min, a stress A (Pa) at the time of 10% elongation, and a stress B after 300 seconds from the elongation stop. (Pa) was measured.
  • the pressure-sensitive adhesive sheet obtained in the examples was cut into a size of 80 mm ⁇ 80 mm, and the pressure-sensitive adhesive layer from which the release sheet was removed was wrapped in a polyester mesh (number of meshes: 200 mesh / inch). Weighed with a precision balance. The mass at this time is M1.
  • the pressure-sensitive adhesive sample was immersed in an ethyl acetate solvent at room temperature (23 ° C.) for 24 hours. Thereafter, the pressure-sensitive adhesive was taken out and air-dried for 24 hours in an environment of a temperature of 23 ° C. and 50% RH, and further dried in an oven at 80 ° C. for 12 hours. The mass of only the pressure-sensitive adhesive after drying was weighed with a precision balance. The mass at this time is M2.
  • the gel fraction (%) is represented by (M2 / M1) ⁇ 100.
  • the measurement results are shown in Table 1.

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  • Adhesive Tapes (AREA)

Abstract

The present invention pertains to an adhesive sheet 1 delamination method for delaminating the adhesive sheet 1 provided with at least an adhesive layer 2 and delaminating attaching bodies W, W' attached to the adhesive surface P of the adhesive layer 2, wherein the method is characterized in that: the adhesive layer 2 has a recess part 3 in the adhesive surface P; the attaching bodies W, W' are attached to the adhesive sheet 1 so that an independent space C is formed by the recess part 3 of the adhesive layer 2; a depressurizing process for expanding a gas inside the space C is performed on the adhesive sheet 1, to which at least the attaching bodies W, W' are attached, to thereby reduce the adhesion of the adhesive layer 2 and delaminate the adhesive sheet 1 and the attaching bodies W, W'. Through this method, the adhesion can be reduced at a desired timing by means of a novel acting mechanism.

Description

粘着シートAdhesive sheet
　本発明は、所望のタイミングで粘着力を低下させることができ、被着体の剥離が容易となる粘着シートに関するものである。 The present invention relates to a pressure-sensitive adhesive sheet that can reduce the adhesive strength at a desired timing and facilitates the peeling of the adherend.
　半導体チップや表示装置などの製造工程においては、半導体ウェハ等の電子部材や表示装置構成部材（電子部材・光学部材）といった加工対象を仮固定するために粘着シートが用いられることがある。かかる粘着シートは、エネルギーを加える等の方法により、所望のタイミングで粘着シートの粘着力を低下させることができるものであり、これにより加工対象（被着体）の剥離が容易となる。前述した製造工程においては、例えば、電子部材や光学部材等の被着体を粘着シートに固定した状態で、所望の加工工程に付される。 In the manufacturing process of a semiconductor chip, a display device, etc., an adhesive sheet may be used to temporarily fix a processing target such as an electronic member such as a semiconductor wafer or a display device constituent member (electronic member / optical member). Such a pressure-sensitive adhesive sheet can reduce the pressure-sensitive adhesive force of the pressure-sensitive adhesive sheet at a desired timing by a method such as applying energy, thereby facilitating the separation of the object to be processed (the adherend). In the manufacturing process described above, for example, it is subjected to a desired processing step in a state where an adherend such as an electronic member or an optical member is fixed to the adhesive sheet.
　かかる粘着シートの粘着力を低下させる方法として、活性エネルギー線硬化型粘着剤を用いて粘着剤層を形成し、活性エネルギー線を照射することで粘着剤層を硬化させて粘着力を低下させる方法（例えば、特許文献１参照）、熱膨張性粒子を粘着剤層に含有させ、加熱により熱膨張性粒子を膨張させて粘着剤層の粘着力を低下させる方法（例えば、特許文献２参照）などが提案されている。 As a method of reducing the adhesive strength of such an adhesive sheet, a method of forming an adhesive layer using an active energy ray-curable adhesive and curing the adhesive layer by irradiating active energy rays to reduce the adhesive strength (For example, refer to Patent Document 1), a method in which thermally expandable particles are contained in an adhesive layer, and the thermally expandable particles are expanded by heating to reduce the adhesive force of the adhesive layer (for example, refer to Patent Document 2). Has been proposed.
特開平８－１８８７５７号公報JP-A-8-188757 特開２０００－２４８２４０号公報JP 2000-248240 A
　本発明は、新規な作用機構により、所望のタイミングで粘着力を低下させることのできる、粘着シートと被着体との剥離方法を提供することを目的とする。 An object of the present invention is to provide a peeling method between an adhesive sheet and an adherend that can reduce the adhesive force at a desired timing by a novel action mechanism.
　第１に本発明は、少なくとも粘着剤層を備える粘着シートと、前記粘着剤層の粘着面に貼着された被着体とを剥離する粘着シートの剥離方法であって、前記粘着剤層は、前記粘着面に凹部を有し、前記被着体は、前記粘着剤層の前記凹部により独立した空間が生じるように前記粘着シートに貼着されており、少なくとも前記被着体が貼着された前記粘着シートに対し、前記空間中の気体を膨張させる減圧処理を行うことにより、前記粘着剤層の粘着力を低下させ、前記粘着シートと前記被着体とを剥離することを特徴とする粘着シートの剥離方法を提供する（発明１）。 1st this invention is a peeling method of the adhesive sheet which peels an adhesive sheet provided with an adhesive layer at least, and the to-be-adhered body stuck on the adhesive surface of the said adhesive layer, Comprising: The said adhesive layer is The adhesive surface has a recess, and the adherend is attached to the adhesive sheet so that an independent space is formed by the recess of the adhesive layer, and at least the adherend is attached. Further, the pressure-sensitive adhesive sheet is peeled from the adherend by reducing the pressure-sensitive adhesive force of the pressure-sensitive adhesive layer by subjecting the pressure-sensitive adhesive sheet to a decompression process for expanding the gas in the space. A method for peeling an adhesive sheet is provided (Invention 1).
　なお、本発明における「シート」には、「テープ」の概念も含まれるものとする。 The “sheet” in the present invention includes the concept of “tape”.
　本発明に係る粘着シートと被着体との剥離方法によれば、減圧処理により前記空間内の気体を膨張させるという新規な作用機構により、所望のタイミングで粘着力を低下させることができ、粘着シートと被着体との剥離を容易にすることができる。 According to the peeling method between the pressure-sensitive adhesive sheet and the adherend according to the present invention, the adhesive force can be reduced at a desired timing by a novel action mechanism of expanding the gas in the space by a decompression process. Peeling of the sheet and the adherend can be facilitated.
　上記発明（発明１）において、前記減圧処理は、前記粘着シートを前記被着体に貼付した環境の雰囲気圧力よりも低くすることが好ましい（発明２）。 In the above invention (Invention 1), it is preferable that the pressure reduction treatment is lower than the atmospheric pressure of the environment in which the adhesive sheet is attached to the adherend (Invention 2).
　上記発明（発明１，２）において、前記粘着剤層を形成する粘着剤組成物は、活性エネルギー線硬化性および熱硬化性を有さないものであってよく（発明３）、かかる発明（発明３）において、前記粘着剤組成物は（メタ）アクリル酸エステル重合体を含有することが好ましい（発明４）。 In the said invention (invention 1 and 2), the adhesive composition which forms the said adhesive layer may not have active energy ray curability and thermosetting (invention 3), and this invention (invention) In 3), it is preferable that the pressure-sensitive adhesive composition contains a (meth) acrylic acid ester polymer (Invention 4).
　上記発明（発明１，２）において、前記粘着剤層を形成する粘着剤組成物は、活性エネルギー線硬化性または熱硬化性を有するものであってよく（発明５）、かかる発明（発明５）において、前記活性エネルギー線硬化性粘着剤組成物は、側鎖に活性エネルギー線硬化性基を有する（メタ）アクリル酸エステル重合体を含有することが好ましい（発明６）。 In the said invention (invention 1 and 2), the adhesive composition which forms the said adhesive layer may have active energy ray curability or thermosetting (invention 5), this invention (invention 5). The active energy ray-curable pressure-sensitive adhesive composition preferably contains a (meth) acrylic acid ester polymer having an active energy ray-curable group in the side chain (Invention 6).
　上記発明（発明５，６）においては、前記粘着剤層に対しエネルギー線を照射して前記粘着剤層を硬化させたのち、前記減圧処理を行ってもよく（発明７）、また、前記減圧処理を行ったのち、前記粘着剤層に対しエネルギー線を照射して前記粘着剤層を硬化させてもよい（発明８）。 In the said invention (invention 5 and 6), after irradiating an energy ray with respect to the said adhesive layer and hardening the said adhesive layer, the said pressure reduction process may be performed (invention 7), and the said pressure reduction After the treatment, the pressure-sensitive adhesive layer may be cured by irradiating the pressure-sensitive adhesive layer with energy rays (Invention 8).
　上記発明（発明１～８）において、前記粘着シートは、前記被着体の仮固定に用いられることが好ましく（発明９）、かかる発明（発明９）において、前記被着体は電子部材または光学部材であってもよい（発明１０）。 In the above inventions (Inventions 1 to 8), the pressure-sensitive adhesive sheet is preferably used for temporarily fixing the adherend (Invention 9). In the invention (Invention 9), the adherend is an electronic member or an optical member. It may be a member (Invention 10).
　第２に本発明は、ワークを加工して得られる加工物の製造方法であって、ワークと、少なくとも粘着剤層を備え、前記粘着剤層の粘着面に凹部を有する粘着シートとを、前記粘着面の前記凹部と前記ワークとで独立した空間が生じるように貼着する貼着工程と、前記粘着シートに貼着された前記ワークを加工して加工物とする加工工程と、少なくとも前記加工物が貼着された前記粘着シートを減圧環境に置いて前記空間中の気体を膨張させる減圧処理を行うことにより、前記粘着剤層の粘着力を低下させ、前記加工物と前記粘着シートとを剥離する剥離工程とを備えることを特徴とする加工物の製造方法を提供する（発明１１）。 2nd this invention is a manufacturing method of the workpiece obtained by processing a workpiece | work, Comprising: A workpiece | work and the adhesive sheet which is provided with an adhesive layer at least and has a recessed part in the adhesive surface of the said adhesive layer, A sticking step of sticking so that an independent space is formed between the concave portion of the adhesive surface and the workpiece, a processing step of processing the workpiece stuck to the pressure sensitive adhesive sheet into a workpiece, and at least the processing The pressure-sensitive adhesive layer is placed in a reduced pressure environment and subjected to a pressure reduction treatment to expand the gas in the space, thereby reducing the adhesive strength of the pressure-sensitive adhesive layer, and the processed product and the pressure-sensitive adhesive sheet. The manufacturing method of the workpiece characterized by providing the peeling process which peels is provided (invention 11).
　本発明に係る粘着シートと被着体との剥離方法によれば、新規な作用機構により、所望のタイミングで粘着力を低下させることができ、粘着シートと被着体との剥離を容易にすることができる。 According to the peeling method between the pressure-sensitive adhesive sheet and the adherend according to the present invention, the adhesive force can be reduced at a desired timing by a novel action mechanism, and the peeling between the pressure-sensitive adhesive sheet and the adherend is facilitated. be able to.
本発明の一実施形態にて用いる粘着シートの断面図である。It is sectional drawing of the adhesive sheet used in one Embodiment of this invention. 凹部の形状の例を模式的に表す粘着剤層の粘着面の平面図である。It is a top view of the adhesion surface of the adhesive layer which represents the example of the shape of a recessed part typically. 凹部の形状の例を模式的に表す粘着剤層の断面模式図である。It is a cross-sectional schematic diagram of the adhesive layer which represents typically the example of the shape of a recessed part. 本発明の一実施形態に係る粘着シートの剥離方法を模式的に表す断面図である。It is sectional drawing which represents typically the peeling method of the adhesive sheet which concerns on one Embodiment of this invention. 実施例１で作成したエンボスフィルム（１）のエンボス加工面をデジタル顕微鏡にて撮影した画像（ａ）および、それを２値化処理して得られた画像（ｂ）である。It is the image (a) which image | photographed the embossing surface of the embossing film (1) created in Example 1 with the digital microscope, and the image (b) obtained by binarizing it. 実施例２で作成したエンボスフィルム（２）のエンボス加工面をデジタル顕微鏡にて撮影した画像（ａ）および、それを２値化処理して得られた画像（ｂ）である。It is the image (a) which image | photographed the embossed surface of the embossed film (2) created in Example 2 with the digital microscope, and the image (b) obtained by binarizing it. 実施例３で作成したエンボスフィルム（３）のエンボス加工面をデジタル顕微鏡にて撮影した画像（ａ）および、それを２値化処理して得られた画像（ｂ）である。It is the image (a) which image | photographed the embossing surface of the embossing film (3) created in Example 3 with the digital microscope, and the image (b) obtained by binarizing it. 実施例１で作成した粘着シートの粘着面をガラス板に貼付して、ガラス越しにデジタル顕微鏡にて撮影した画像（ａ）および、２値化処理して得られた画像（ｂ）である。It is the image (b) obtained by sticking the adhesive surface of the adhesive sheet produced in Example 1 on the glass plate, and image | photographing with the digital microscope through glass, and the binarization process. 実施例２で作成した粘着シートの粘着面をガラス板に貼付して、ガラス越しにデジタル顕微鏡にて撮影した画像（ａ）および、２値化処理して得られた画像（ｂ）である。It is the image (b) obtained by sticking the adhesive surface of the adhesive sheet produced in Example 2 on the glass plate, and image | photographing with the digital microscope through glass, and the binarization process. 実施例３で作成した粘着シートの粘着面をガラス板に貼付して、ガラス越しにデジタル顕微鏡にて撮影した画像（ａ）および、２値化処理して得られた画像（ｂ）である。It is the image (b) obtained by sticking the adhesive surface of the adhesive sheet created in Example 3 on a glass plate, and image | photographing with the digital microscope through glass, and the binarization process.
　以下、本発明の実施形態について説明する。
　本実施形態に係る粘着シートの剥離方法は、少なくとも粘着剤層を備える粘着シートと、当該粘着剤層の粘着面に貼着された被着体とを剥離する方法である。
　かかる粘着剤層は、粘着面に凹部を有し、被着体と粘着シートとは、粘着剤層の凹部により独立した空間が生じるように互いに貼着される。本実施形態においては、少なくとも被着体が貼着された粘着シートに対し、凹部と被着体とにより生じた空間中の気体を膨張させる減圧処理を行うことにより、粘着剤層の粘着力を低下させ、粘着シートと被着体との剥離を容易にする。 Hereinafter, embodiments of the present invention will be described.
The peeling method of the adhesive sheet which concerns on this embodiment is a method of peeling an adhesive sheet provided with an adhesive layer at least, and the to-be-adhered body stuck on the adhesive surface of the said adhesive layer.
The pressure-sensitive adhesive layer has a concave portion on the pressure-sensitive adhesive surface, and the adherend and the pressure-sensitive adhesive sheet are bonded to each other so that an independent space is generated by the concave portion of the pressure-sensitive adhesive layer. In the present embodiment, at least the pressure-sensitive adhesive sheet to which the adherend is adhered is subjected to a pressure reduction treatment for expanding the gas in the space generated by the recess and the adherend, thereby increasing the adhesive strength of the pressure-sensitive adhesive layer. Decrease and facilitate separation of the adhesive sheet and the adherend.
〔粘着シート〕
　図１は本発明の一実施形態にて用いる粘着シートの断面図である。本実施形態に係る粘着シート１は、粘着剤層２を備えて構成され、粘着剤層２は、粘着面Ｐ；被着体と接触する面（図１における上側の面）に凹部３を有する。また、本実施形態に係る粘着シート１は、粘着剤層における粘着面Ｐとは反対側の面（図１における下側の面）に、さらに基材４を備えてもよい。本実施形態に係る粘着シート１は、例えば、電子部材や光学部材を仮固定するために用いることができる。以下、半導体ウェハを仮固定するために用いられる場合を中心に説明する。 [Adhesive sheet]
FIG. 1 is a sectional view of an adhesive sheet used in one embodiment of the present invention. The pressure-sensitive adhesive sheet 1 according to the present embodiment includes a pressure-sensitive adhesive layer 2, and the pressure-sensitive adhesive layer 2 has a pressure-sensitive adhesive surface P; a concave portion 3 on a surface that contacts the adherend (the upper surface in FIG. 1). . Moreover, the adhesive sheet 1 which concerns on this embodiment may be further equipped with the base material 4 in the surface (lower surface in FIG. 1) on the opposite side to the adhesive surface P in an adhesive layer. The pressure-sensitive adhesive sheet 1 according to this embodiment can be used for temporarily fixing an electronic member or an optical member, for example. Hereinafter, the case where it is used for temporarily fixing a semiconductor wafer will be mainly described.
（１）粘着剤層
　粘着剤層は、活性エネルギー線硬化性および熱硬化性を有しない（以下、本明細書において「非硬化性」ということがある。）の粘着剤組成物から形成される粘着剤層であってもよいし、活性エネルギー線硬化性または熱硬化性を有する粘着剤組成物から形成される粘着剤層であってもよい。また、粘着剤層が多層からなる場合には、非硬化性の粘着剤層と硬化性の粘着剤層とを組み合わせたものであってもよい。 (1) Pressure-sensitive adhesive layer The pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition that does not have active energy ray curability and thermosetting (hereinafter sometimes referred to as “non-curable” in the present specification). It may be a pressure-sensitive adhesive layer, or may be a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition having active energy ray curability or thermosetting. When the pressure-sensitive adhesive layer is composed of multiple layers, a combination of a non-curable pressure-sensitive adhesive layer and a curable pressure-sensitive adhesive layer may be used.
（１－１）非硬化性粘着剤組成物
　非硬化性の粘着剤組成物としては、例えば、アクリル系粘着剤組成物、ゴム系粘着剤組成物、シリコーン系粘着剤組成物、ウレタン系粘着剤組成物、ポリエステル系粘着剤組成物、ポリビニルエーテル系粘着剤組成物等が挙げられ、中でもアクリル系粘着剤組成物が好ましい。アクリル系粘着剤組成物としては、従来公知の（メタ）アクリル酸エステル重合体を含有するものを用いることができる。なお、本明細書における「重合体」には「共重合体」の概念も含まれるものとする。 (1-1) Non-curable pressure-sensitive adhesive composition Examples of the non-curable pressure-sensitive adhesive composition include acrylic pressure-sensitive adhesive compositions, rubber-based pressure-sensitive adhesive compositions, silicone-based pressure-sensitive adhesive compositions, and urethane-based pressure-sensitive adhesives. Examples thereof include a composition, a polyester-based pressure-sensitive adhesive composition, a polyvinyl ether-based pressure-sensitive adhesive composition, and among them, an acrylic pressure-sensitive adhesive composition is preferable. As an acrylic adhesive composition, what contains a conventionally well-known (meth) acrylic acid ester polymer can be used. In the present specification, the term “polymer” includes the concept of “copolymer”.
　アクリル系粘着剤組成物に含まれる（メタ）アクリル酸エステル重合体（Ａ）は、１種類の（メタ）アクリル酸エステルモノマーから形成された単独重合体であってもよいし、複数種類の（メタ）アクリル酸エステルモノマーから形成された共重合体であってもよいし、１種類または複数種類の（メタ）アクリル酸エステルモノマーと（メタ）アクリル酸エステルモノマー以外のモノマーとから形成された共重合体であってもよい。また、（メタ）アクリル酸エステル重合体（Ａ）は、１種を単独で用いてもよいし、２種以上を組み合わせて用いてもよい。（メタ）アクリル酸エステルモノマーとなる化合物の具体的な種類は特に限定されず、（メタ）アクリル酸、（メタ）アクリル酸エステル、その誘導体（アクリロニトリル、イタコン酸など）が具体例として挙げられる。（メタ）アクリル酸エステルについてさらに具体例を示せば、メチル（メタ）アクリレート、エチル（メタ）アクリレート、プロピル（メタ）アクリレート、ブチル（メタ）アクリレート、２－エチルヘキシル（メタ）アクリレート等の鎖状骨格を有する（メタ）アクリレート；シクロへキシル（メタ）アクリレート、ベンジル（メタ）アクリレート、イソボルニル（メタ）アクリレート、ジシクロペンタニル（メタ）アクリレート、イミド（メタ）アクリレート、（メタ）アクリロイルモルフォリン等の環状骨格を有する（メタ）アクリレート；２－ヒドロキシエチル（メタ）アクリレート、２－ヒドロキシプロピル（メタ）アクリレート、３－ヒドロキシプロピル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレート等のヒドロキシ基を有する（メタ）アクリレート；グリシジル（メタ）アクリレート、Ｎ－メチルアミノエチル（メタ）アクリレート等のヒドロキシ基以外の反応性官能基を有する（メタ）アクリレートが挙げられる。また、（メタ）アクリル酸エステルモノマー以外のモノマーとして、エチレン、ノルボルネン等のオレフィン、酢酸ビニル、スチレンなどが例示される。なお、（メタ）アクリル酸エステルモノマーがアルキル（メタ）アクリレートである場合には、そのアルキル基の炭素数は１～１８の範囲であることが好ましい。また、本明細書において、（メタ）アクリル酸とは、アクリル酸およびメタクリル酸の両方を意味する。他の類似用語も同様である。 The (meth) acrylic acid ester polymer (A) contained in the acrylic pressure-sensitive adhesive composition may be a homopolymer formed from one type of (meth) acrylic acid ester monomer, or a plurality of types of ( The copolymer may be a copolymer formed from a (meth) acrylate monomer, or a copolymer formed from one or more types of (meth) acrylate monomers and monomers other than (meth) acrylate monomers. It may be a polymer. Moreover, a (meth) acrylic acid ester polymer (A) may be used individually by 1 type, and may be used in combination of 2 or more type. Specific types of the compound that becomes the (meth) acrylic acid ester monomer are not particularly limited, and specific examples include (meth) acrylic acid, (meth) acrylic acid ester, and derivatives thereof (acrylonitrile, itaconic acid, and the like). Specific examples of (meth) acrylic acid esters include chain skeletons such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. (Meth) acrylate having cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, imide (meth) acrylate, (meth) acryloylmorpholine, etc. (Meth) acrylates having a cyclic skeleton; such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, etc. Having Dorokishi group (meth) acrylate; glycidyl (meth) acrylate, (meth) acrylates having reactive functional groups other than hydroxy group, such as N- methylaminoethyl (meth) acrylate. Examples of monomers other than (meth) acrylic acid ester monomers include olefins such as ethylene and norbornene, vinyl acetate, and styrene. When the (meth) acrylic acid ester monomer is an alkyl (meth) acrylate, the alkyl group preferably has 1 to 18 carbon atoms. Moreover, in this specification, (meth) acrylic acid means both acrylic acid and methacrylic acid. The same applies to other similar terms.
　本実施形態における粘着剤層を形成する粘着剤組成物が、後述する架橋剤を含有する場合には、（メタ）アクリル酸エステル重合体（Ａ）は、粘着剤組成物にそのまま含有されていてもよく、また少なくともその一部が架橋剤と架橋反応を行って架橋物として含有されていてもよい。この場合において、（メタ）アクリル酸エステル重合体（Ａ）は、架橋剤と反応する反応性官能基を有することが好ましい。反応性官能基の種類は特に限定されず、架橋剤の種類などに基づいて適宜決定すればよい。 When the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer in the present embodiment contains a crosslinking agent described later, the (meth) acrylic acid ester polymer (A) is directly contained in the pressure-sensitive adhesive composition. In addition, at least a part thereof may be contained as a crosslinked product by performing a crosslinking reaction with a crosslinking agent. In this case, the (meth) acrylic acid ester polymer (A) preferably has a reactive functional group that reacts with the crosslinking agent. The type of the reactive functional group is not particularly limited, and may be appropriately determined based on the type of the crosslinking agent.
　例えば、架橋剤がポリイソシアネート化合物である場合には、（メタ）アクリル酸エステル重合体（Ａ）が有する反応性官能基として、ヒドロキシ基、カルボキシル基、アミノ基などが例示され、中でもイソシアネート基との反応性の高いヒドロキシ基が好ましい。また、架橋剤がエポキシ系化合物である場合には、（メタ）アクリル酸エステル重合体（Ａ）が有する反応性官能基として、カルボキシル基、アミノ基、アミド基などが例示され、中でもエポキシ基との反応性の高いカルボキシル基が好ましい。 For example, when the crosslinking agent is a polyisocyanate compound, examples of the reactive functional group of the (meth) acrylic acid ester polymer (A) include a hydroxy group, a carboxyl group, and an amino group. These highly reactive hydroxy groups are preferred. Further, when the crosslinking agent is an epoxy compound, examples of the reactive functional group of the (meth) acrylic acid ester polymer (A) include a carboxyl group, an amino group, an amide group, etc. These highly reactive carboxyl groups are preferred.
　（メタ）アクリル酸エステル重合体（Ａ）に反応性官能基を導入する方法は特に限定されず、一例として、反応性官能基を有するモノマーを用いて（メタ）アクリル酸エステル重合体（Ａ）を形成し、反応性官能基を有するモノマーに基づく構成単位を重合体の骨格に含有させる方法が挙げられる。例えば、（メタ）アクリル酸エステル重合体（Ａ）にカルボキシル基を導入する場合は、（メタ）アクリル酸などのカルボキシル基を有するモノマーを用いて（メタ）アクリル酸エステル重合体（Ａ）を形成すればよい。 The method for introducing the reactive functional group into the (meth) acrylic acid ester polymer (A) is not particularly limited. As an example, the (meth) acrylic acid ester polymer (A) using a monomer having a reactive functional group is used. And a constitutional unit based on a monomer having a reactive functional group is contained in the polymer skeleton. For example, when a carboxyl group is introduced into the (meth) acrylic acid ester polymer (A), a (meth) acrylic acid ester polymer (A) is formed using a monomer having a carboxyl group such as (meth) acrylic acid. do it.
　（メタ）アクリル酸エステル重合体（Ａ）が反応性官能基を有する場合には、架橋の程度を良好な範囲にする観点から、（メタ）アクリル酸エステル重合体（Ａ）全体の質量に占める反応性官能基を有するモノマー由来の構造部分の質量の割合が、１～２０質量％程度であることが好ましく、２～１０質量％であることがより好ましい。 When the (meth) acrylic acid ester polymer (A) has a reactive functional group, it accounts for the total mass of the (meth) acrylic acid ester polymer (A) from the viewpoint of making the degree of crosslinking a good range. The proportion of the mass of the structural portion derived from the monomer having a reactive functional group is preferably about 1 to 20% by mass, and more preferably 2 to 10% by mass.
　（メタ）アクリル酸エステル重合体（Ａ）の重量平均分子量（Ｍｗ）は、塗布時の造膜性の観点から１万～２００万であることが好ましく、１０万～１５０万であることがより好ましい。なお、本明細書において、（メタ）アクリル酸エステル重合体（Ａ）ならびに後述する（メタ）アクリル酸エステル重合体（Ｂ１）および（Ｂ３）の重量平均分子量は、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）法により測定した標準ポリスチレン換算の値であり、測定方法の詳細は後述する実施例にて示す。また、（メタ）アクリル酸エステル重合体（Ａ）のガラス転移温度Ｔｇは、好ましくは－７０℃～３０℃、さらに好ましくは－６０℃～２０℃の範囲にある。ガラス転移温度は、Ｆｏｘ式より計算することができる。 The weight average molecular weight (Mw) of the (meth) acrylic acid ester polymer (A) is preferably 10,000 to 2,000,000, and more preferably 100,000 to 1,500,000 from the viewpoint of film forming properties at the time of coating. preferable. In addition, in this specification, the weight average molecular weights of the (meth) acrylic acid ester polymer (A) and the (meth) acrylic acid ester polymers (B1) and (B3) described later are gel permeation chromatography (GPC). It is a value in terms of standard polystyrene measured by the method, and details of the measuring method are shown in the examples described later. The glass transition temperature Tg of the (meth) acrylic acid ester polymer (A) is preferably in the range of −70 ° C. to 30 ° C., more preferably in the range of −60 ° C. to 20 ° C. The glass transition temperature can be calculated from the Fox equation.
（１－２）活性エネルギー線硬化性粘着剤組成物
　活性エネルギー線硬化性粘着剤組成物は、活性エネルギー線硬化性化合物（Ｂ２）、および側鎖に活性エネルギー線硬化性基が導入された（メタ）アクリル酸エステル重合体（Ｂ３）のうち少なくともいずれか一方を含有するものであることが好ましい。ここで、活性エネルギー線硬化性粘着剤組成物は、活性エネルギー線硬化性化合物（Ｂ２）、および側鎖に活性エネルギー線硬化性基が導入された（メタ）アクリル酸エステル重合体（Ｂ３）のうちいずれか一方を含有するものであってもよいが、両方を含有するものであることが好ましい。これらの場合において、活性エネルギー線硬化性粘着剤組成物は、さらに活性エネルギー線硬化性を有しない（メタ）アクリル酸エステル重合体（Ｂ１）を含有してもよい。 (1-2) Active energy ray-curable pressure-sensitive adhesive composition The active energy ray-curable pressure-sensitive adhesive composition has an active energy ray-curable compound (B2) and an active energy ray-curable group introduced into the side chain ( It is preferable that at least one of the (meth) acrylic acid ester polymer (B3) is contained. Here, the active energy ray-curable pressure-sensitive adhesive composition is composed of the active energy ray-curable compound (B2) and the (meth) acrylic acid ester polymer (B3) in which an active energy ray-curable group is introduced into the side chain. One of them may be contained, but it is preferred that both are contained. In these cases, the active energy ray-curable pressure-sensitive adhesive composition may further contain a (meth) acrylic acid ester polymer (B1) having no active energy ray curability.
（１－２－１）活性エネルギー線硬化性を有しない（メタ）アクリル酸エステル重合体（Ｂ１）
　本実施形態における粘着剤層を形成する粘着剤組成物が活性エネルギー線硬化性を有しない（メタ）アクリル酸エステル重合体（Ｂ１）を含有する場合、当該（メタ）アクリル酸エステル重合体（Ｂ１）は、粘着剤組成物にそのまま含有されていてもよく、また少なくともその一部が後述する架橋剤と架橋反応を行って架橋物として含有されていてもよい。（メタ）アクリル酸エステル重合体（Ｂ１）としては、非硬化性粘着剤組成物に関して前述した（メタ）アクリル酸エステル重合体（Ａ）と同様のものを用いることができる。 (1-2-1) (Meth) acrylic acid ester polymer having no active energy ray curability (B1)
When the adhesive composition which forms the adhesive layer in this embodiment contains the (meth) acrylic acid ester polymer (B1) which does not have active energy ray curability, the said (meth) acrylic acid ester polymer (B1) ) May be contained in the pressure-sensitive adhesive composition as it is, or at least a part thereof may be contained as a crosslinked product by performing a crosslinking reaction with a crosslinking agent described later. As (meth) acrylic acid ester polymer (B1), the same thing as the (meth) acrylic acid ester polymer (A) mentioned above regarding the non-curable adhesive composition can be used.
（１－２－２）活性エネルギー線硬化性化合物（Ｂ２）
　活性エネルギー線硬化性化合物（Ｂ２）は、活性エネルギー線硬化性基を有し、紫外線、電子線等の活性エネルギー線の照射を受けると重合する化合物である。活性エネルギー線硬化性化合物（Ｂ２）が有する活性エネルギー線硬化性基は、例えば活性エネルギー線硬化性の炭素－炭素二重結合を含む基であり、具体的には、（メタ）アクリロイル基、ビニル基などを例示することができる。 (1-2-2) Active energy ray-curable compound (B2)
The active energy ray curable compound (B2) is a compound having an active energy ray curable group and polymerized when irradiated with active energy rays such as ultraviolet rays and electron beams. The active energy ray-curable group possessed by the active energy ray-curable compound (B2) is, for example, a group containing an active energy ray-curable carbon-carbon double bond, and specifically includes a (meth) acryloyl group, vinyl Examples include groups.
　活性エネルギー線硬化性化合物（Ｂ２）の例としては、上記の活性エネルギー線硬化性基を有していれば特に限定されないが、汎用性の観点から低分子量化合物（単官能、多官能のモノマーおよびオリゴマー）であることが好ましい。低分子量の活性エネルギー線硬化性化合物（Ｂ２）の具体例としては、トリメチロールプロパントリ（メタ）アクリレート、テトラメチロールメタンテトラ（メタ）アクリレート、ペンタエリスリトールトリ（メタ）アクリレート、ジペンタエリスリトールモノヒドロキシペンタ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレートあるいは１，４－ブチレングリコールジ（メタ）アクリレート、１，６－ヘキサンジオールジ（メタ）アクリレート、ジシクロペンタジエンジメトキシジ（メタ）アクリレート、イソボルニル（メタ）アクリレートなどの環状脂肪族骨格含有（メタ）アクリレート、ポリエチレングリコールジ（メタ）アクリレート、オリゴエステル（メタ）アクリレート、ウレタン（メタ）アクリレートオリゴマー、エポキシ変性（メタ）アクリレート、ポリエーテル（メタ）アクリレート、などのアクリレート系化合物が挙げられ、これらは１種を単独でまたは２種以上を組み合わせて用いることができる。 Examples of the active energy ray-curable compound (B2) are not particularly limited as long as the active energy ray-curable group has the above-mentioned active energy ray-curable group. However, low molecular weight compounds (monofunctional and polyfunctional monomers and Oligomer) is preferable. Specific examples of the low molecular weight active energy ray-curable compound (B2) include trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, pentaerythritol tri (meth) acrylate, and dipentaerythritol monohydroxypenta. (Meth) acrylate, dipentaerythritol hexa (meth) acrylate or 1,4-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, dicyclopentadiene dimethoxydi (meth) acrylate, isobornyl ( Cyclic aliphatic skeleton-containing (meth) acrylates such as (meth) acrylate, polyethylene glycol di (meth) acrylate, oligoester (meth) acrylate, urethane (meth) acrylate Oligomers, epoxy-modified (meth) acrylate, polyether (meth) acrylates, include acrylate compounds such as these may be used alone or in admixture.
　活性エネルギー線硬化性化合物（Ｂ２）は、通常は分子量が１００～３００００、好ましくは３００～１００００程度である。 The active energy ray-curable compound (B2) usually has a molecular weight of 100 to 30,000, preferably about 300 to 10,000.
　活性エネルギー線硬化性粘着剤組成物における活性エネルギー線硬化性化合物（Ｂ２）の含有量および他の成分との含有量比は特に制限されないが、活性エネルギー線硬化性粘着剤組成物が、活性エネルギー線硬化性化合物（Ｂ２）と活性エネルギー線硬化性を有しない（メタ）アクリル酸エステル重合体（Ｂ１）とを含有する場合、活性エネルギー線硬化性化合物（Ｂ２）は、上記（メタ）アクリル酸エステル重合体（Ｂ１）１００質量部に対し、好ましくは１０～４００質量部、より好ましくは３０～３５０質量部程度の割合で用いられる。また、活性エネルギー線硬化性化合物（Ｂ２）と、後述する側鎖に活性エネルギー線硬化性基が導入された（メタ）アクリル酸エステル重合体（Ｂ３）とを含有する場合には、当該（メタ）アクリル酸エステル重合体（Ｂ３）１００質量部に対して、活性エネルギー線硬化性化合物（Ｂ２）の含有量が上記の範囲であることが好ましい。さらに、活性エネルギー線硬化性粘着剤組成物が、活性エネルギー線硬化性化合物（Ｂ２）と、上記（メタ）アクリル酸エステル重合体（Ｂ１）および側鎖に活性エネルギー線硬化性基が導入された（メタ）アクリル酸エステル重合体（Ｂ３）とを含有する場合には、（メタ）アクリル酸エステル重合体（Ｂ１）および（メタ）アクリル酸エステル重合体（Ｂ３）の合計量１００質量部に対して、活性エネルギー線硬化性化合物（Ｂ２）の含有量が上記の範囲であることが好ましい。 The content of the active energy ray-curable compound (B2) in the active energy ray-curable adhesive composition and the content ratio with other components are not particularly limited, but the active energy ray-curable adhesive composition is active energy. In the case of containing the linear curable compound (B2) and the (meth) acrylic acid ester polymer (B1) having no active energy ray curable, the active energy ray curable compound (B2) is the above (meth) acrylic acid. The amount is preferably 10 to 400 parts by mass, more preferably about 30 to 350 parts by mass with respect to 100 parts by mass of the ester polymer (B1). Moreover, when it contains the active energy ray-curable compound (B2) and the (meth) acrylic acid ester polymer (B3) in which an active energy ray-curable group is introduced in the side chain described later, ) The content of the active energy ray-curable compound (B2) is preferably in the above range with respect to 100 parts by mass of the acrylic ester polymer (B3). Furthermore, the active energy ray-curable pressure-sensitive adhesive composition has the active energy ray-curable compound (B2), the (meth) acrylic acid ester polymer (B1), and the active energy ray-curable group introduced into the side chain. When it contains the (meth) acrylic acid ester polymer (B3), the total amount of the (meth) acrylic acid ester polymer (B1) and the (meth) acrylic acid ester polymer (B3) is 100 parts by mass. The content of the active energy ray-curable compound (B2) is preferably in the above range.
（１－２－３）側鎖に活性エネルギー線硬化性基が導入された（メタ）アクリル酸エステル重合体（Ｂ３）
　本実施形態における活性エネルギー線硬化性粘着剤組成物が側鎖に活性エネルギー線硬化性基が導入された（メタ）アクリル酸エステル重合体（Ｂ３）を含有する場合、かかる（メタ）アクリル酸エステル重合体（Ｂ３）は、粘着剤組成物にそのまま含有されていてもよく、また少なくともその一部が後述する架橋剤と架橋反応を行って架橋物として含有されていてもよい。 (1-2-3) (Meth) acrylic acid ester polymer (B3) having an active energy ray-curable group introduced in the side chain
When the active energy ray-curable pressure-sensitive adhesive composition in the present embodiment contains a (meth) acrylic acid ester polymer (B3) having an active energy ray-curable group introduced in the side chain, such (meth) acrylic acid ester The polymer (B3) may be contained in the pressure-sensitive adhesive composition as it is, or at least a part thereof may be contained as a crosslinked product by performing a crosslinking reaction with a crosslinking agent described later.
　側鎖に活性エネルギー線硬化性基が導入された（メタ）アクリル酸エステル重合体（Ｂ３）の主骨格は特に限定はされず、前述の（メタ）アクリル酸エステル重合体（Ｂ１）と同様のものが例示される。 The main skeleton of the (meth) acrylic acid ester polymer (B3) in which the active energy ray-curable group is introduced into the side chain is not particularly limited, and is the same as that of the aforementioned (meth) acrylic acid ester polymer (B1). Are illustrated.
　（メタ）アクリル酸エステル重合体（Ｂ３）の側鎖に導入される活性エネルギー線硬化性基は、例えば活性エネルギー線硬化性の炭素－炭素二重結合を含む基であり、具体的には（メタ）アクリロイル基等を例示することができる。活性エネルギー線硬化性基は、アルキレン基、アルキレンオキシ基、ポリアルキレンオキシ基等を介して（メタ）アクリル酸エステル重合体（Ｂ３）に結合していてもよい。 The active energy ray-curable group introduced into the side chain of the (meth) acrylate polymer (B3) is, for example, a group containing an active energy ray-curable carbon-carbon double bond. A meth) acryloyl group etc. can be illustrated. The active energy ray-curable group may be bonded to the (meth) acrylic acid ester polymer (B3) via an alkylene group, an alkyleneoxy group, a polyalkyleneoxy group, or the like.
　側鎖に活性エネルギー線硬化性基が導入された（メタ）アクリル酸エステル重合体（Ｂ３）は、例えば、ヒドロキシ基、カルボキシル基、アミノ基、置換アミノ基、エポキシ基等の官能基を含有する（メタ）アクリル酸エステル重合体と、当該官能基と反応する置換基および活性エネルギー線硬化性炭素－炭素二重結合を１分子毎に１～５個を有する硬化性基含有化合物とを反応させて得られる。かかる（メタ）アクリル酸エステル重合体は、ヒドロキシ基、カルボキシル基、アミノ基、置換アミノ基、エポキシ基等の官能基を有する（メタ）アクリル酸エステルモノマーまたはその誘導体と、前述した成分（Ｂ１）を構成するモノマーとから共重合することで得られる。また、上記硬化性基含有化合物としては、（メタ）アクリロイルオキシエチルイソシアネート、メタ－イソプロペニル－α，α－ジメチルベンジルイソシアネート、（メタ）アクリロイルイソシアネート、アリルイソシアネート、グリシジル（メタ）アクリレート、（メタ）アクリル酸等が挙げられ、これらは１種を単独でまたは２種以上を組み合わせて用いることができる。 The (meth) acrylic acid ester polymer (B3) in which an active energy ray-curable group is introduced into the side chain contains, for example, a functional group such as a hydroxy group, a carboxyl group, an amino group, a substituted amino group, and an epoxy group. A (meth) acrylic acid ester polymer is reacted with a substituent that reacts with the functional group and a curable group-containing compound having 1 to 5 active energy ray-curable carbon-carbon double bonds per molecule. Obtained. Such a (meth) acrylic acid ester polymer includes a (meth) acrylic acid ester monomer or a derivative thereof having a functional group such as a hydroxy group, a carboxyl group, an amino group, a substituted amino group, and an epoxy group, and the component (B1) described above. It can be obtained by copolymerizing with a monomer that constitutes. Examples of the curable group-containing compound include (meth) acryloyloxyethyl isocyanate, meta-isopropenyl-α, α-dimethylbenzyl isocyanate, (meth) acryloyl isocyanate, allyl isocyanate, glycidyl (meth) acrylate, (meth) Acrylic acid etc. are mentioned, These can be used individually by 1 type or in combination of 2 or more types.
　また、本実施形態における粘着剤層を形成する粘着剤組成物が、後述する架橋剤を含有する場合には、側鎖に活性エネルギー線硬化性基が導入された（メタ）アクリル酸エステル重合体（Ｂ３）は、架橋剤と反応する反応性官能基を有することが好ましい。反応性官能基の種類は特に限定されず、前述した（メタ）アクリル酸エステル重合体（Ｂ１）（および非硬化性粘着剤組成物に関して前述した（メタ）アクリル酸エステル重合体（Ａ））と同様のものを例示することができる。 Moreover, when the adhesive composition which forms the adhesive layer in this embodiment contains the crosslinking agent mentioned later, the active energy ray hardening group was introduce | transduced into the side chain (meth) acrylic acid ester polymer (B3) preferably has a reactive functional group that reacts with the crosslinking agent. The kind of the reactive functional group is not particularly limited, and the (meth) acrylic acid ester polymer (B1) described above (and the (meth) acrylic acid ester polymer (A) described above with respect to the non-curable pressure-sensitive adhesive composition) and The same thing can be illustrated.
　側鎖に活性エネルギー線硬化性基が導入された（メタ）アクリル酸エステル重合体（Ｂ３）の重量平均分子量（Ｍｗ）は、１０万～２００万であることが好ましく、３０万～１５０万であることがより好ましい。 The weight average molecular weight (Mw) of the (meth) acrylic acid ester polymer (B3) having an active energy ray-curable group introduced in the side chain is preferably 100,000 to 2,000,000, and 300,000 to 1,500,000. More preferably.
　また、（メタ）アクリル酸エステル重合体（Ｂ３）のガラス転移温度（Ｔｇ）は、好ましくは－７０～３０℃、より好ましくは－６０～２０℃の範囲にある。なお、本明細書において（メタ）アクリル酸エステル重合体（Ｂ３）のガラス転移温度（Ｔｇ）は、硬化性基含有化合物と反応させる前の（メタ）アクリル酸エステル重合体のものを指す。 The glass transition temperature (Tg) of the (meth) acrylic acid ester polymer (B3) is preferably in the range of −70 to 30 ° C., more preferably in the range of −60 to 20 ° C. In addition, in this specification, the glass transition temperature (Tg) of the (meth) acrylic acid ester polymer (B3) refers to that of the (meth) acrylic acid ester polymer before being reacted with the curable group-containing compound.
（１－３）熱硬化性粘着剤組成物
　熱硬化型粘着剤組成物としては、エポキシ樹脂、フェノール樹脂などを含有するものが挙げられる。 (1-3) Thermosetting pressure-sensitive adhesive composition Examples of the thermosetting pressure-sensitive adhesive composition include those containing an epoxy resin, a phenol resin, and the like.
（１－４）架橋剤
　本実施形態における粘着剤層を形成する粘着剤組成物は、前述した粘着剤組成物に含まれる重合体と反応し得る架橋剤を含有してもよい。この場合には、本実施形態における粘着剤層は、粘着剤組成物に含まれる重合体（（メタ）アクリル酸エステル重合体（Ａ）、（Ｂ１）、（Ｂ３）等）と架橋剤との架橋反応により得られた架橋物を含有する。 (1-4) Crosslinking agent The adhesive composition forming the adhesive layer in this embodiment may contain a crosslinking agent capable of reacting with the polymer contained in the above-mentioned adhesive composition. In this case, the pressure-sensitive adhesive layer in this embodiment comprises a polymer ((meth) acrylic acid ester polymer (A), (B1), (B3), etc.) contained in the pressure-sensitive adhesive composition and a crosslinking agent. Contains a cross-linked product obtained by a cross-linking reaction.
　架橋剤の種類としては、例えば、ポリイソシアネート系化合物、エポキシ系化合物、金属キレート系化合物、アジリジン系化合物等のポリイミン化合物、メラミン樹脂、尿素樹脂、ジアルデヒド類、メチロールポリマー、金属アルコキシド、金属塩等が挙げられ、１種を単独でまたは２種以上を組み合わせて用いることができる。これらの中でも、架橋反応を制御し易いことなどの理由により、エポキシ系化合物またはポリイソシアネート化合物であることが好ましい。 Examples of the crosslinking agent include polyimine compounds such as polyisocyanate compounds, epoxy compounds, metal chelate compounds, and aziridine compounds, melamine resins, urea resins, dialdehydes, methylol polymers, metal alkoxides, metal salts, and the like. 1 type can be used individually or in combination of 2 or more types. Among these, an epoxy compound or a polyisocyanate compound is preferable because it is easy to control the crosslinking reaction.
　ポリイソシアネート化合物は、１分子当たりイソシアネート基を２個以上有する化合物である。具体的には、トリレンジイソシアネート、ジフェニルメタンジイソシアネート、キシリレンジイソシアネート等の芳香族ポリイソシアネート、ヘキサメチレンジイソシアネート等の脂肪族ポリイソシアネート、イソホロンジイソシアネート、水素添加ジフェニルメタンジイソシアネート等の脂環式ポリイソシアネートなど、及びそれらのビウレット体、イソシアヌレート体、さらにはエチレングリコール、プロピレングリコール、ネオペンチルグリコール、トリメチロールプロパン、ヒマシ油等の低分子活性水素含有化合物との反応物であるアダクト体などが挙げられる。 A polyisocyanate compound is a compound having two or more isocyanate groups per molecule. Specifically, aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like Biuret bodies, isocyanurate bodies, and adduct bodies that are a reaction product with a low molecular active hydrogen-containing compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, castor oil, and the like.
　エポキシ系化合物としては、例えば、１，３－ビス（Ｎ，Ｎ’－ジグリシジルアミノメチル）シクロヘキサン、Ｎ，Ｎ，Ｎ’，Ｎ’－テトラグリシジル－ｍ－キシリレンジアミン、エチレングリコールジグリシジルエーテル、１，６－ヘキサンジオールジグリシジルエーテル、トリメチロールプロパンジグリシジルエーテル、ジグリシジルアニリン、ジグリシジルアミン等が挙げられる。 Examples of the epoxy compound include 1,3-bis (N, N′-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine, ethylene glycol diglycidyl ether. 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidylaniline, diglycidylamine and the like.
　粘着剤層を形成する粘着剤組成物の架橋剤の含有量は、粘着剤組成物に含まれる重合体（例えば、（メタ）アクリル酸エステル重合体（Ａ）、（Ｂ１）および（Ｂ３））の合計量１００質量部に対し、０．０１～５０質量部であることが好ましく、０．０２～１０質量部、０．０３～５質量部であることがより好ましく、０．０５～２質量部であることがより好ましく、０．０８～０．５質量部であることが特に好ましい。 The content of the crosslinking agent in the pressure-sensitive adhesive composition that forms the pressure-sensitive adhesive layer is the polymer contained in the pressure-sensitive adhesive composition (for example, (meth) acrylic acid ester polymers (A), (B1) and (B3)). Is preferably 0.01 to 50 parts by mass, more preferably 0.02 to 10 parts by mass, and more preferably 0.03 to 5 parts by mass with respect to 100 parts by mass of the total amount of Part is more preferable, and 0.08 to 0.5 part by mass is particularly preferable.
　本実施形態における粘着剤層を形成する粘着剤組成物が架橋剤を含有する場合には、その架橋剤の種類などに応じて、適切な架橋促進剤を含有してもよい。 When the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer in the present embodiment contains a crosslinking agent, an appropriate crosslinking accelerator may be contained depending on the type of the crosslinking agent.
（１－５）その他の成分
　本実施形態における粘着剤層を形成する粘着剤組成物は、上記の成分に加えて、光重合開始剤、光増感剤、架橋促進剤、染料や顔料等の着色材料、難燃剤、充填材、熱伝導剤、粘着付与剤、可塑剤、帯電防止剤などの各種添加剤を含有してもよい。特に、粘着剤組成物が紫外線等の活性エネルギー線によって硬化する活性エネルギー線硬化性を有する場合は、当該粘着剤組成物は、光重合開始剤を含有することが好ましい。 (1-5) Other components The pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer in the present embodiment includes, in addition to the above components, a photopolymerization initiator, a photosensitizer, a crosslinking accelerator, a dye, a pigment, and the like. You may contain various additives, such as a coloring material, a flame retardant, a filler, a heat conductive agent, a tackifier, a plasticizer, and an antistatic agent. In particular, when the pressure-sensitive adhesive composition has active energy ray curability that is cured by active energy rays such as ultraviolet rays, the pressure-sensitive adhesive composition preferably contains a photopolymerization initiator.
　光重合開始剤としては、ベンゾイン化合物、アセトフェノン化合物、アシルフォスフィンオキサイド化合物、チタノセン化合物、チオキサントン化合物、パーオキサイド化合物等の光開始剤、アミンやキノン等の光増感剤などが挙げられ、具体的には、１－ヒドロキシシクロヘキシルフェニルケトン、ベンゾイン、ベンゾインメチルエーテル、ベンゾインエチルエーテル、ベンゾインイソプロピルエーテル、ベンジルジフェニルサルファイド、テトラメチルチウラムモノサルファイド、アゾビスイソブチロニトリル、ジベンジル、ジアセチル、β－クロールアンスラキノン、２，４，６－トリメチルベンゾイルジフェニルフォスフィンオキサイドなどが例示され、これらは１種を単独でまたは２種以上を組み合わせて用いることができる。エネルギー線として紫外線を用いる場合には、光重合開始剤を配合することにより照射時間、照射量を少なくすることができる。 Examples of photopolymerization initiators include photoinitiators such as benzoin compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, thioxanthone compounds, and peroxide compounds, and photosensitizers such as amines and quinones. 1-hydroxycyclohexyl phenyl ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyldiphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, β- chloranthraquinone 2,4,6-trimethylbenzoyldiphenylphosphine oxide and the like, and these can be used alone or in combination of two or more. When ultraviolet rays are used as energy rays, the irradiation time and irradiation amount can be reduced by blending a photopolymerization initiator.
（２）凹部
　粘着剤層２は、粘着面Ｐに凹部３を有する。後述するように、本実施形態に係る粘着シートの剥離方法において、被着体は、粘着剤層２の凹部３により空間が生じるように粘着シート１（の粘着面Ｐ）に貼着される。 (2) Concave part The adhesive layer 2 has the concave part 3 in the adhesive surface P. As shown in FIG. As will be described later, in the pressure-sensitive adhesive sheet peeling method according to the present embodiment, the adherend is adhered to the pressure-sensitive adhesive sheet 1 (the pressure-sensitive adhesive surface P) so that a space is generated by the concave portion 3 of the pressure-sensitive adhesive layer 2.
　粘着剤層２は、独立した凹部３を有することが好ましい。ここで、凹部３が独立したとは、凹部３の外縁の全てが、粘着面Ｐを構成する平面部（非凹部ということがある。）により囲まれていることを意味し、言い換えると凹部３が粘着シート１の端部に連通していないことを意味する。粘着剤層２が独立した凹部３を有していると、被着体と、粘着剤層２の凹部３とにより生じる空間を、独立した空間とすることが容易となる。 The pressure-sensitive adhesive layer 2 preferably has an independent recess 3. Here, that the concave portion 3 is independent means that the entire outer edge of the concave portion 3 is surrounded by a flat surface portion (sometimes referred to as a non-recessed portion) constituting the adhesive surface P, in other words, the concave portion 3. Means that it does not communicate with the end of the pressure-sensitive adhesive sheet 1. When the pressure-sensitive adhesive layer 2 has the independent recess 3, it becomes easy to make the space generated by the adherend and the recess 3 of the pressure-sensitive adhesive layer 2 an independent space.
　また、粘着剤層２は、複数の凹部３を有していることが好ましい。粘着剤層２が凹部３を複数有していることで、被着体と、粘着剤層２の凹部３とにより生じる空間を、独立した空間とすることが容易となる。さらには、粘着剤層２は、複数の独立した凹部３を有していることが特に好ましい。なお、粘着剤層２が凹部を複数有している場合は、必ずしも全ての凹部３が独立している必要はなく、その一部は粘着シート１の端部に連通していてもよい。 The pressure-sensitive adhesive layer 2 preferably has a plurality of recesses 3. Since the pressure-sensitive adhesive layer 2 has a plurality of recesses 3, it is easy to make the space generated by the adherend and the recesses 3 of the pressure-sensitive adhesive layer 2 independent spaces. Furthermore, it is particularly preferable that the pressure-sensitive adhesive layer 2 has a plurality of independent recesses 3. In addition, when the adhesive layer 2 has two or more recessed parts, all the recessed parts 3 do not necessarily need to be independent, and the one part may be connected with the edge part of the adhesive sheet 1. FIG.
　凹部３の形状は特に限定されず、例えば、凹部３を複数有する場合、それぞれの凹部３は同様の形状であってもよく、それぞれが異なる形状であってもよい。例えば、凹部３は、図２に示すように、粘着面Ｐにおける凹部３の形状を平面視したときに、円状（楕円状や長円状を含む）（図２（ａ））、四角形状等の凸多角形状（同（ｂ））、星形状等の凹多角形状（同（ｃ））等の他、これらを組み合わせ所定のパターンに配置したもの（同（ｄ），（ｅ））であってもよく、さらに、不定形な形状（同（ｆ））であってもよい。 The shape of the recess 3 is not particularly limited. For example, when a plurality of recesses 3 are provided, each recess 3 may have the same shape or may have a different shape. For example, as shown in FIG. 2, the concave portion 3 has a circular shape (including an elliptical shape or an oval shape) (FIG. 2A), a rectangular shape when the shape of the concave portion 3 on the adhesive surface P is viewed in plan view. In addition to a convex polygonal shape (the same (b)), a concave polygonal shape such as a star shape (the same (c)), etc., these are combined and arranged in a predetermined pattern (the same (d), (e)) It may also be an irregular shape (same (f)).
　ここで、図２（ｄ）においては、複数の矩形状の凹部３１が長辺方向に平行に並列配置されて一つの繰り返し単位Ｕが形成され、繰り返し単位Ｕを構成する矩形状凹部３１の長辺方向が交互となるように、複数の繰り返し単位Ｕが縦横に繰り返し配置されている。
　また、図２（ｅ）においては、複数の矩形状の凹部３２と、２つの直角三角形状の凹部３３とで一つの繰り返し単位Ｕ’が形成され、かかる繰り返し単位Ｕ’が縦横に配置されている。繰り返し単位Ｕ’においては、直角三角形状凹部３３において直角を形成する１辺と矩形状凹部３２の長辺とが平行となり、直角三角形状凹部３３の斜辺と矩形状凹部３２の短辺とが向かい合うようにして、矩形状凹部３２および直角三角形状凹部３３が配置される。複数の矩形状凹部３２は、直角三角形状凹部３３から離れるにしたがって長辺が長いものとなっている。
　図２（ｆ）においては、凹部３４は不定形な形状を有しており、凹部３４の大きさ（長さ、幅、深さ等）は特定の値に限定されない。また、一つの凹部３４における幅や方向は連続的または断続的に変化しており、枝分かれ状の形状を有していてもよい。 Here, in FIG. 2D, a plurality of rectangular concave portions 31 are arranged in parallel in the long side direction to form one repeating unit U, and the length of the rectangular concave portion 31 constituting the repeating unit U is long. A plurality of repeating units U are repeatedly arranged vertically and horizontally so that the side directions are alternated.
In FIG. 2E, a plurality of rectangular recesses 32 and two right-angled triangular recesses 33 form one repeating unit U ′, and the repeating units U ′ are arranged vertically and horizontally. Yes. In the repeating unit U ′, one side forming a right angle in the right triangular recess 33 is parallel to the long side of the rectangular recess 32, and the oblique side of the right triangular recess 33 faces the short side of the rectangular recess 32. In this way, the rectangular recess 32 and the right triangle recess 33 are arranged. The plurality of rectangular recesses 32 have long sides that become longer as they move away from the right triangle recess 33.
In FIG. 2 (f), the recess 34 has an irregular shape, and the size (length, width, depth, etc.) of the recess 34 is not limited to a specific value. Further, the width and direction of one concave portion 34 are continuously or intermittently changed, and may have a branched shape.
　さらに、後述する実施例にて示す通り、エンボスパターンを粘着剤層に転写するエンボス加工により凹部３を形成する場合、エンボスパターンとしては、正三角形、直角三角形、正方形、長方形、ひし形等の多角形；五芒星、六芒星等の星形多角形；円；楕円；扇形、ハート型等の曲線を有する多角形等の形状を複数設けた定形の繰り返しパターンが挙げられる。またリネン地などの布目を模した形状；梨地、砂目、水玉模様などのドット状形状等の非定型の繰り返しパターンが挙げられる。かかるエンボスパターンは、被着体との間で独立した空間を生じさせる凹部３を形成できるものであれば、特に限定されないが、独立した凹部３を形成できるものであることが好ましく、また、端部に連通していないものが好ましく、複数の独立した凹部３を形成できるものであることが特に好ましい。 Furthermore, as shown in the examples described later, when the recess 3 is formed by embossing to transfer the embossed pattern to the adhesive layer, the embossed pattern may be a polygon such as a regular triangle, a right triangle, a square, a rectangle, a rhombus, etc. A star-shaped polygon such as a pentagram or a hexagon; a circle; an ellipse; a regular repetitive pattern provided with a plurality of shapes such as a polygon having a curved shape such as a fan shape or a heart shape. Moreover, the shape which imitated the texture of linen fabric etc .; Atypical repetitive patterns, such as dot-like shapes, such as a satin finish, a grain, and a polka dot pattern, are mentioned. Such an emboss pattern is not particularly limited as long as it can form a recess 3 that creates an independent space with the adherend. However, it is preferable that the emboss pattern can form an independent recess 3. Those not communicating with the portion are preferred, and it is particularly preferred that a plurality of independent recesses 3 can be formed.
　凹部３の断面形状は、図３に示すように、半円状（図３（ａ））、四角形状（同（ｂ））、台形状（同（ｃ））、三角形状（同（ｄ））等、様々な形状とすることができる。 As shown in FIG. 3, the cross-sectional shape of the recess 3 is semicircular (FIG. 3A), quadrangular (same (b)), trapezoid (same (c)), triangular (same (d)). ) And the like.
　ここで、本実施形態において、凹部３は、減圧処理を行うことにより凹部３と被着体とにより生じた空間中の気体を膨張させ、粘着剤層２の粘着力を効果的に低下させる観点から、膨張した気体が局所的に集中しやすい形状であることが好ましい。具体的には、粘着面Ｐにおける凹部３の形状は、凸多角形状、凹多角形状、または不定形な形状であることが好ましい。 Here, in this embodiment, the recessed part 3 expands the gas in the space produced by the recessed part 3 and a to-be-adhered body by performing a pressure reduction process, and a viewpoint which reduces the adhesive force of the adhesive layer 2 effectively. Therefore, it is preferable that the expanded gas has a shape that tends to concentrate locally. Specifically, the shape of the concave portion 3 on the adhesive surface P is preferably a convex polygonal shape, a concave polygonal shape, or an irregular shape.
　凹部３の高さは、２μｍ以上粘着剤層２の厚さ以下であることが好ましく、５μｍ以上粘着剤層２の厚さ以下であることが特に好ましく、１０μｍ以上粘着剤層２の厚さ以下であることがさらに好ましく、２０μｍ以上粘着剤層２の厚さ以下であることが特に好ましい。凹部３の高さが２μｍ以上であると、凹部３と被着体との間で十分な空間が生じ、かかる空間中の気体を効果的に膨張させることができる。 The height of the recess 3 is preferably 2 μm or more and not more than the thickness of the pressure-sensitive adhesive layer 2, particularly preferably 5 μm or more and not more than the thickness of the pressure- sensitive adhesive layer 2, and 10 μm or more and the thickness of the pressure-sensitive adhesive layer 2 or less. It is more preferable that the thickness is 20 μm or more and not more than the thickness of the pressure-sensitive adhesive layer 2. When the height of the recess 3 is 2 μm or more, a sufficient space is generated between the recess 3 and the adherend, and the gas in the space can be effectively expanded.
　粘着面Ｐの総面積に対する凹部面積の割合（以下、凹部面積率ともいう。）は、下限値が３％以上であることが好ましく、１０％以上であることが特に好ましく、２５％以上であることがさらに好ましい。また、凹部面積率の上限値は、９０％以下であることが好ましく、７５％以下であることが特に好ましく、６０％以下であることがさらに好ましい。凹部面積率が３％以上であると、凹部３と被着体との間で十分な空間が生じるため、減圧処理を行ったときに、かかる空間において気体膨張による圧力が大きなものとなり、粘着力を効果的に低下させることができる。一方、凹部面積率が９０％以下であると、被着体との接触面積を十分確保することができるため、所望の粘着力を確保することができる。 The lower limit of the ratio of the recessed area to the total area of the adhesive surface P (hereinafter also referred to as recessed area ratio) is preferably 3% or more, particularly preferably 10% or more, and 25% or more. More preferably. Further, the upper limit value of the recessed area ratio is preferably 90% or less, particularly preferably 75% or less, and further preferably 60% or less. When the area ratio of the recess is 3% or more, a sufficient space is generated between the recess 3 and the adherend. Therefore, when decompression processing is performed, the pressure due to gas expansion becomes large in the space, and the adhesive strength Can be effectively reduced. On the other hand, when the recess area ratio is 90% or less, a sufficient contact area with the adherend can be ensured, so that a desired adhesive force can be secured.
　ここで、凹部面積率は、粘着面Ｐを平面視したときの凹部をデジタル顕微鏡を用いて、撮影倍率が２０～１００倍で、粘着面Ｐの画像を取得し、当該画像に対して画像処理（２値化処理）を行い、凹部面積の合計値を自動面積計測することにより測定することができる。具体的には、粘着面Ｐの任意に選択した所定の領域Ｄにおいて下記式に基づき算出した値を、凹部面積率と見做すことができる。詳細な測定方法は後述する実施例にて示す。 Here, the concave area ratio is obtained by obtaining an image of the adhesive surface P at a photographing magnification of 20 to 100 times using a digital microscope and imaging the concave surface when the adhesive surface P is viewed in plan. It can be measured by performing (binarization processing) and automatically measuring the total area of the recessed areas. Specifically, a value calculated based on the following formula in a predetermined region D arbitrarily selected on the adhesive surface P can be regarded as a recess area ratio. A detailed measurement method will be described in Examples described later.
　凹部３の形成方法としては、例えば、エンボスパターンを粘着剤層に転写するエンボス加工が挙げられる。この場合、エンボスパターンにおける凸部が粘着剤層に転写され、粘着面の凹部３となる。ここで、エンボスパターンが形成された面（エンボス面）の総面積に対する凸部面積の割合（以下、凸部面積率ともいう。）は、下限値が３０％以上であることが好ましく、５０％以上であることが特に好ましく、７０％以上であることがさらに好ましい。また、凸部面積率の上限値は、９８％以下であることが好ましく、９５％以下であることが特に好ましく、９０％以下であることがさらに好ましい。 Examples of the method for forming the recess 3 include embossing in which an emboss pattern is transferred to an adhesive layer. In this case, the convex portion in the emboss pattern is transferred to the pressure-sensitive adhesive layer and becomes the concave portion 3 on the pressure-sensitive adhesive surface. Here, the ratio of the convex area to the total area of the surface (embossed surface) on which the embossed pattern is formed (hereinafter also referred to as convex area ratio) is preferably 30% or more as a lower limit, and 50%. It is particularly preferable that the ratio is 70% or more. Further, the upper limit value of the convex area ratio is preferably 98% or less, particularly preferably 95% or less, and further preferably 90% or less.
　エンボス面における凸部面積率は、比較的軟質な粘着剤層に対しエンボス加工を施す場合などにおいて、粘着面Ｐの凹部面積率と必ずしも一致するものではない。ただし、このような場合であっても、エンボス面における凸部面積率が上記範囲にあると、エンボスパターンが転写された粘着面Ｐにおいて、凹部面積率を前述した好ましい範囲に収めることが容易となる。 The convex area ratio on the embossed surface does not necessarily coincide with the concave area ratio of the adhesive surface P when embossing is performed on a relatively soft adhesive layer. However, even in such a case, when the convex area ratio on the embossed surface is in the above range, it is easy to keep the concave area ratio in the above-described preferable range on the adhesive surface P to which the embossed pattern is transferred. Become.
　エンボス面における凸部面積率は、エンボス面を平面視したときの凸部をデジタル顕微鏡、レーザ顕微鏡、又は電子顕微鏡などを用いて、撮影倍率が２０～１０００倍で、エンボス面の画像を取得し、当該画像に対して画像処理（２値化処理）を行い、凸部面積の合計値を自動面積計測することにより測定することができる。具体的には、エンボス面の任意に選択した所定の領域Ｔにおいて下記式に基づき算出した値を、凸部面積率と見做すことができる。詳細な測定方法は後述する実施例にて示す。 The convex area ratio on the embossed surface is obtained by obtaining an image of the embossed surface when the embossed surface is viewed in plan using a digital microscope, a laser microscope, or an electron microscope with a shooting magnification of 20 to 1000 times. Then, image processing (binarization processing) is performed on the image, and the total value of the convex area can be measured by automatic area measurement. Specifically, a value calculated based on the following formula in a predetermined region T arbitrarily selected on the embossed surface can be regarded as a convex area ratio. A detailed measurement method will be described in Examples described later.
　エンボス加工以外の凹部３の形成方法としては、例えば、凹部３が形成されるようにパターン印刷する方法であってもよく、粘着剤層に対しレーザを照射するレーザ熱加工により凹部３を形成してもよい。
　さらに、不定形な形状の凹部３を形成する方法として、国際公開第２０１５／１５２３４７号に記載される方法も例示することができる。その具体的な一例として、微粒子の含有量が多く樹脂の含有量が少ない組成物からなる塗膜と、主成分として樹脂を含有する組成物からなる塗膜とを別々に形成し、これら２つの塗膜を同時に乾燥させる方法が挙げられる。かかる方法によれば、塗膜内部において微粒子に起因する収縮応力差が発生し、塗膜の割れを生じさせ、かかる塗膜の割れに周辺の樹脂が流入することで、凹部３が形成されると考えられる。 As a method for forming the recesses 3 other than the embossing, for example, a pattern printing method may be used so that the recesses 3 are formed. The recesses 3 are formed by laser thermal processing for irradiating a laser to the adhesive layer. May be.
Furthermore, the method described in International Publication No. 2015/152347 can also be illustrated as a method of forming the recess 3 having an irregular shape. As a specific example, a coating film made of a composition having a high content of fine particles and a small content of resin and a coating film made of a composition containing a resin as a main component are separately formed. The method of drying a coating film simultaneously is mentioned. According to this method, the shrinkage stress difference caused by the fine particles is generated inside the coating film, causing cracking of the coating film, and the peripheral resin flows into the cracking of the coating film, thereby forming the recess 3. it is conceivable that.
（３）粘着剤層の物性等
（３－１）厚さ
　本実施形態における粘着剤層の厚さは、５～１００μｍであることが好ましく、１０～５０μｍであることが特に好ましく、１５～３０μｍであることがさらに好ましい。粘着剤層の厚さが５μｍ以上であると、減圧時の空間をより多く確保できるため、好ましい。粘着剤層の厚さが１００μｍ以下であると、塗布時の膜厚精度が確保できるため、好ましい。 (3) Physical properties of pressure-sensitive adhesive layer, etc. (3-1) Thickness The thickness of the pressure-sensitive adhesive layer in this embodiment is preferably 5 to 100 μm, particularly preferably 10 to 50 μm, and 15 to 30 μm. More preferably. It is preferable that the pressure-sensitive adhesive layer has a thickness of 5 μm or more because more space can be secured during decompression. It is preferable for the thickness of the pressure-sensitive adhesive layer to be 100 μm or less because the film thickness accuracy during application can be ensured.
（３－２）粘着力
　粘着シートの粘着力は、０．５～５０Ｎ／２５ｍｍであることが好ましく、２～４０Ｎ／２５ｍｍであることがより好ましく、５～３０Ｎ／２５ｍｍであることが特に好ましい。粘着シートの粘着力が上記の範囲内にあることで、被着体を確実に固定することができ、例えば、被着体の加工工程における被着体の仮固定に非常に有用である。 (3-2) Adhesive strength The adhesive strength of the adhesive sheet is preferably 0.5 to 50 N / 25 mm, more preferably 2 to 40 N / 25 mm, and particularly preferably 5 to 30 N / 25 mm. . When the adhesive strength of the pressure-sensitive adhesive sheet is within the above range, the adherend can be reliably fixed. For example, it is very useful for temporarily fixing the adherend in the processing step of the adherend.
　なお、ここでいう粘着力は、後述する減圧処理を行っていない（粘着剤組成物が活性エネルギー線硬化性または熱硬化性を有する場合は、さらに活性エネルギー線の照射および加熱を行っていない）粘着シートについて、シリコンミラーウェハを被着体とし、その鏡面に粘着シートを貼り合わせ、ＪＩＳ　Ｚ０２３７：２００９に準じた１８０°引き剥がし法により測定した粘着力（ｍＮ／２５ｍｍ）とする。 In addition, the adhesive force here does not perform the pressure reduction process mentioned later (When the adhesive composition has active energy ray curable property or thermosetting property, irradiation and heating of the active energy ray are not further performed). About an adhesive sheet, let a silicon mirror wafer be a to-be-adhered body, stick an adhesive sheet on the mirror surface, and let it be the adhesive force (mN / 25mm) measured by 180 degree peeling method according to JISZ0237: 2009.
（３－３）粘着力減少率
　粘着シートの粘着力減少率は、１０％以上であることが好ましく、２０％以上であることがより好ましく、３０％以上であることが特に好ましい。粘着シートの粘着力が上記の範囲内にあることで、本実施形態において粘着シートと被着体との剥離がさらに容易になる。 (3-3) Adhesive strength reduction rate The adhesive strength reduction rate of the adhesive sheet is preferably 10% or more, more preferably 20% or more, and particularly preferably 30% or more. When the adhesive strength of the adhesive sheet is within the above range, in this embodiment, the adhesive sheet and the adherend are more easily separated.
　なお、ここでいう粘着力減少率は、後述する減圧処理を行う前（粘着剤組成物が活性エネルギー線硬化性または熱硬化性を有する場合は、活性エネルギー線の照射または加熱を行った後）の粘着シートと、減圧処理を行った後（粘着剤組成物が活性エネルギー線硬化性または熱硬化性を有する場合は、活性エネルギー線の照射および加熱を行った後）の粘着シートとのそれぞれにおいて、前述したように粘着力を測定し、得られた値に基づき以下の式によって算出される。
　粘着力減少率（％）＝（減圧前粘着力－減圧後粘着力）／（減圧前粘着力）×１００ In addition, the adhesive force decreasing rate here is before performing the pressure reduction process mentioned later (When the adhesive composition has active energy ray curable or thermosetting, after irradiation or heating of active energy rays) In each of the pressure-sensitive adhesive sheet and the pressure-sensitive adhesive sheet after being subjected to reduced pressure treatment (when the pressure-sensitive adhesive composition has active energy ray curable or thermosetting properties, after irradiation and heating with active energy rays) The adhesive strength is measured as described above, and is calculated by the following formula based on the obtained value.
Adhesive strength reduction rate (%) = (adhesive strength before decompression−adhesive strength after decompression) / (adhesive strength before decompression) × 100
　なお、後述するとおり、粘着剤組成物が活性エネルギー線硬化性または熱硬化性を有する場合の活性エネルギー線の照射または加熱は、減圧処理の前であっても後であってもよいが、いずれの場合であっても粘着力減少率は上記式によって算出されるものとする。 As will be described later, the irradiation or heating of the active energy ray when the pressure-sensitive adhesive composition has active energy ray curable property or thermosetting property may be before or after the decompression treatment, Even in this case, the adhesive strength reduction rate is calculated by the above formula.
（３－４）応力緩和率
　本実施形態において、粘着剤層の応力緩和率の下限値は、４０％以上であることが好ましく、５０％以上であることが特に好ましく、５５％以上であることがさらに好ましい。粘着剤層の応力緩和率の上限値は、９０％以下であることが好ましく、８５％以下であることが特に好ましく、８０％以下であることがさらに好ましい。応力緩和率を前述の範囲に設定することで、粘着剤層が減圧時にバランス良く安定的に変形することができる。 (3-4) Stress relaxation rate In the present embodiment, the lower limit value of the stress relaxation rate of the pressure-sensitive adhesive layer is preferably 40% or more, particularly preferably 50% or more, and 55% or more. Is more preferable. The upper limit of the stress relaxation rate of the pressure-sensitive adhesive layer is preferably 90% or less, particularly preferably 85% or less, and further preferably 80% or less. By setting the stress relaxation rate within the above-described range, the pressure-sensitive adhesive layer can be stably deformed with good balance during decompression.
　なお、ここでいう粘着剤層の応力緩和率は、後述する減圧処理を行っていない（粘着剤組成物が活性エネルギー線硬化性または熱硬化性を有する場合は、活性エネルギー線の照射または加熱を行った後）粘着剤層について、引張試験にて１０％伸長させて３００秒保持した後の応力緩和率をいう。引張試験は、具体的には、厚さ５０μｍ、幅１５ｍｍ、長さ１２０ｍｍ（このうち測定範囲は１００ｍｍ）に成形した粘着剤を、２３℃、５０％ＲＨの環境下で、２００ｍｍ／分の速度で１０％伸長させて行うものとする。 In addition, the stress relaxation rate of an adhesive layer here is not performing the pressure reduction process mentioned later (When an adhesive composition has active energy ray sclerosis | hardenability or thermosetting, irradiation or heating of an active energy ray is carried out. After the test) The pressure-sensitive adhesive layer is the stress relaxation rate after being stretched by 10% in a tensile test and held for 300 seconds. Specifically, the tensile test was performed at a speed of 200 mm / min with an adhesive formed into a thickness of 50 μm, a width of 15 mm, and a length of 120 mm (of which the measurement range is 100 mm) in an environment of 23 ° C. and 50% RH. And 10% elongation.
（３－５）破断伸度
　本実施形態において、粘着剤層の破断伸度の下限値は、１１０％以上であることが好ましく、１２０％以上であることが特に好ましく、１３０％以上であることがさらに好ましい。また、粘着剤層の破断伸度の上限値は、３００％以下であることが好ましく、２００％以下であることが特に好ましく、１５０％以下であることがさらに好ましい。粘着剤層の破断伸度を前述の範囲に設定することで、粘着剤層が減圧時にバランス良く安定的に変形することができる。 (3-5) Breaking elongation In this embodiment, the lower limit of the breaking elongation of the pressure-sensitive adhesive layer is preferably 110% or more, particularly preferably 120% or more, and preferably 130% or more. Is more preferable. The upper limit of the elongation at break of the pressure-sensitive adhesive layer is preferably 300% or less, particularly preferably 200% or less, and further preferably 150% or less. By setting the breaking elongation of the pressure-sensitive adhesive layer within the above-described range, the pressure-sensitive adhesive layer can be stably deformed with a good balance during decompression.
　なお、ここでいう粘着剤層の破断伸度は、後述する減圧処理を行っていない（粘着剤組成物が活性エネルギー線硬化性または熱硬化性を有する場合は、活性エネルギー線の照射または加熱を行なった後）粘着剤層について、基材等を伴わない単独の粘着剤層として測定し、具体的には、厚さ５０μｍ、幅１５ｍｍ、長さ１２０ｍｍ（このうち測定範囲は１００ｍｍ）に成形した粘着剤を、２３℃、５０％ＲＨの環境下で、２００ｍｍ／分の速度で伸長させて行うものとする。 Note that the elongation at break of the pressure-sensitive adhesive layer here is not subjected to the pressure reduction treatment described later (if the pressure-sensitive adhesive composition has active energy ray curable or thermosetting properties, irradiation with active energy rays or heating is performed. After the measurement was performed, the pressure-sensitive adhesive layer was measured as a single pressure-sensitive adhesive layer without a substrate or the like. Specifically, the pressure-sensitive adhesive layer was formed into a thickness of 50 μm, a width of 15 mm, and a length of 120 mm (of which the measurement range was 100 mm) The pressure-sensitive adhesive is stretched at a speed of 200 mm / min in an environment of 23 ° C. and 50% RH.
（３－６）ゲル分率
　本実施形態において、粘着剤層のゲル分率の下限値は、２％以上であることが好ましく、４％以上であることが特に好ましく、６％以上であることがさらに好ましい。粘着剤層のゲル分率の上限値は、９０％以下であることが好ましく、４０％以下であることが特に好ましく、１５％以下であることがさらに好ましい。粘着剤層のゲル分率の下限値が２％以上であると、架橋による粘着剤同士の反応により、粘着シートとしての安定性が確保できる。一方、粘着剤層のゲル分率の上限値が９０％以下であると粘着シート上にタックを付与し易く、良好な仮固定性を得ることができる。 (3-6) Gel fraction In this embodiment, the lower limit of the gel fraction of the pressure-sensitive adhesive layer is preferably 2% or more, particularly preferably 4% or more, and 6% or more. Is more preferable. The upper limit of the gel fraction of the pressure-sensitive adhesive layer is preferably 90% or less, particularly preferably 40% or less, and further preferably 15% or less. When the lower limit of the gel fraction of the pressure-sensitive adhesive layer is 2% or more, the stability of the pressure-sensitive adhesive sheet can be ensured by the reaction between the pressure-sensitive adhesives due to crosslinking. On the other hand, if the upper limit of the gel fraction of the pressure-sensitive adhesive layer is 90% or less, it is easy to impart tack to the pressure-sensitive adhesive sheet, and good temporary fixability can be obtained.
　なお、ここでいう粘着剤層のゲル分率は、後述する減圧処理を行っていない（粘着剤組成物が活性エネルギー線硬化性または熱硬化性を有する場合は、さらに活性エネルギー線の照射および加熱を行っていない）粘着剤層についての貼付時（シーズニング期間経過後）での値である。具体的には、粘着剤を剥離シートに塗布し、加熱乾燥した後、２３℃、５０％ＲＨの環境下にて７日間保管した後のゲル分率をいう。なお、粘着剤のゲル分率は、シーズニング期間経過後であれば安定することから、シーズニング期間が経過しているかどうか不明の場合、改めて、２３℃、５０％ＲＨの環境下にて７日間保管した後、測定すればよい。 In addition, the gel fraction of an adhesive layer here is not performing the pressure reduction process mentioned later (When an adhesive composition has active energy ray sclerosis | hardenability or thermosetting property, irradiation and heating of an active energy ray are further carried out. It is the value at the time of sticking (after the seasoning period has elapsed) about the pressure-sensitive adhesive layer. Specifically, it refers to the gel fraction after the pressure-sensitive adhesive is applied to a release sheet, dried by heating, and stored for 7 days in an environment of 23 ° C. and 50% RH. In addition, since the gel fraction of the adhesive is stable after the seasoning period has elapsed, if it is unclear whether the seasoning period has elapsed, it is stored again in an environment of 23 ° C. and 50% RH for 7 days. And then measure.
（４）基材
　本実施形態に係る粘着シートは、粘着剤層に加えて、基材を備えていてもよい。ここで、基材は、粘着シートが被着体の加工工程などの所望の工程において適切に機能できる限り、その構成材料は特に限定されず、例えば、紙基材、樹脂フィルム又はシート、紙基材を樹脂でラミネートした基材等が挙げられ、本実施形態の一態様の粘着シートの用途に応じて適宜選択することができる。中でも、減圧効果に対する有利さから、樹脂系の材料を主材とするフィルムから構成されることが好ましい。そのフィルムの具体例として、エチレン－酢酸ビニル共重合体フィルム、エチレン－（メタ）アクリル酸共重合体フィルム、エチレン－（メタ）アクリル酸エステル共重合体フィルム等のエチレン系共重合フィルム；低密度ポリエチレン（ＬＤＰＥ）フィルム、直鎖低密度ポリエチレン（ＬＬＤＰＥ）フィルム、高密度ポリエチレン（ＨＤＰＥ）フィルム等のポリエチレンフィルム、ポリプロピレンフィルム、ポリブテンフィルム、ポリブタジエンフィルム、ポリメチルペンテンフィルム、エチレン－ノルボルネン共重合体フィルム、ノルボルネン樹脂フィルム等のポリオレフィン系フィルム；ポリ塩化ビニルフィルム、塩化ビニル共重合体フィルム等のポリ塩化ビニル系フィルム；ポリエチレンテレフタレートフィルム、ポリブチレンテレフタレートフィルム等のポリエステル系フィルム；ポリウレタンフィルム；ポリイミドフィルム；ポリスチレンフィルム；ポリカーボネートフィルム；フッ素樹脂フィルムなどが挙げられる。またこれらの架橋フィルム、アイオノマーフィルムのような変性フィルムも用いられる。上記の基材はこれらの１種からなるフィルムでもよいし、さらにこれらを２種類以上組み合わせた積層フィルムであってもよい。 (4) Base material The pressure-sensitive adhesive sheet according to this embodiment may include a base material in addition to the pressure-sensitive adhesive layer. Here, the base material is not particularly limited as long as the pressure-sensitive adhesive sheet can appropriately function in a desired process such as an adherend processing process. For example, a paper base material, a resin film or sheet, a paper base The base material etc. which laminated the material with resin are mentioned, According to the use of the adhesive sheet of 1 aspect of this embodiment, it can select suitably. Among these, it is preferable that the film is composed of a film mainly composed of a resin-based material because of its advantage for the decompression effect. Specific examples of such films include ethylene-copolymer films such as ethylene-vinyl acetate copolymer films, ethylene- (meth) acrylic acid copolymer films, and ethylene- (meth) acrylic acid ester copolymer films; low density Polyethylene films such as polyethylene (LDPE) film, linear low density polyethylene (LLDPE) film, high density polyethylene (HDPE) film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, ethylene-norbornene copolymer film, Polyolefin film such as norbornene resin film; Polyvinyl chloride film such as polyvinyl chloride film and vinyl chloride copolymer film; Polyethylene terephthalate film, Polybutylene tele Polyester film of tallate films; polyurethane film; polyimide film; polystyrene films; polycarbonate films; and fluorine resin film. Further, modified films such as these crosslinked films and ionomer films are also used. The substrate may be a film made of one of these, or may be a laminated film in which two or more of these are combined.
　基材を構成するフィルムは、エチレン系共重合フィルムおよびポリオレフィン系フィルムの少なくとも一種を備えることが好ましい。エチレン系共重合フィルムは共重合比を変えることなどによりその機械特性を広範な範囲で制御することが容易である。このため、エチレン系共重合フィルムを備える基材は本実施形態に係る粘着シートの基材として求められる機械特性を満たし易い。また、エチレン系共重合フィルムは粘着剤層に対する密着性が比較的高いため、粘着シートとして使用した際に基材と粘着剤層との界面での剥離が生じ難い。 The film constituting the base material preferably includes at least one of an ethylene copolymer film and a polyolefin film. It is easy to control the mechanical characteristics of an ethylene copolymer film in a wide range by changing the copolymerization ratio. For this reason, the base material provided with the ethylene-based copolymer film easily satisfies the mechanical properties required as the base material of the pressure-sensitive adhesive sheet according to this embodiment. Moreover, since the ethylene copolymer film has relatively high adhesion to the pressure-sensitive adhesive layer, peeling at the interface between the base material and the pressure-sensitive adhesive layer hardly occurs when used as a pressure-sensitive adhesive sheet.
　本実施形態において用いる基材には、上記の樹脂系材料を主材とするフィルム内に、顔料、染料、難燃剤、可塑剤、帯電防止剤、滑剤、フィラー等の各種添加剤が含まれていてもよい。顔料としては、例えば、二酸化チタン、カーボンブラック等が挙げられる。また、フィラーとしては、メラミン樹脂のような有機系材料、ヒュームドシリカのような無機系材料およびニッケル粒子のような金属系材料が例示される。こうした添加剤の含有量は特に限定されないが、基材が所望の機能を発揮し、平滑性や柔軟性を失わない範囲に留めるべきである。 The base material used in the present embodiment contains various additives such as pigments, dyes, flame retardants, plasticizers, antistatic agents, lubricants, fillers, etc., in the film mainly composed of the above-mentioned resin-based material. May be. Examples of the pigment include titanium dioxide and carbon black. Examples of the filler include organic materials such as melamine resin, inorganic materials such as fumed silica, and metal materials such as nickel particles. The content of such an additive is not particularly limited, but should be within a range where the substrate exhibits a desired function and does not lose smoothness and flexibility.
　粘着剤層を硬化させるために照射するエネルギー線として紫外線を用い、基材側から照射する場合には、基材は紫外線に対して透過性を有することが好ましい。また、エネルギー線として電子線を用いる場合には、基材は電子線の透過性を有していることが好ましい。ただし、被着体がエネルギー線透過性を有し、エネルギー線を被着体側から照射する場合は、基材がエネルギー線透過性を有している必要はない。 When ultraviolet rays are used as the energy rays to be irradiated to cure the pressure-sensitive adhesive layer and irradiation is performed from the substrate side, the substrate is preferably permeable to ultraviolet rays. Moreover, when using an electron beam as an energy beam, it is preferable that the base material has the transparency of an electron beam. However, when the adherend has energy ray permeability and the energy beam is irradiated from the adherend side, the substrate does not need to have energy ray permeability.
　また、基材の粘着剤層側の面（以下「基材被着面」ともいう。）には、カルボキシル基、ならびにそのイオンおよび塩からなる群から選ばれる１種または２種以上を有する成分が存在することが好ましい。基材における上記の成分と粘着剤層に係る成分（粘着剤層を構成する成分および架橋剤などの粘着剤層を形成するにあたり使用される成分が例示される。）とが化学的に相互作用することにより、これらの間で剥離が生じる可能性を低減させることができる。基材被着面にそのような成分を存在させるための具体的な手法は特に限定されない。例えば、基材自体をエチレン－（メタ）アクリル酸共重合体フィルム、アイオノマー樹脂フィルム等として、基材を構成する材料となる樹脂がカルボキシル基、ならびにそのイオンおよび塩からなる群から選ばれる１種または２種以上を有するものとするのであってもよい。基材被着面に上記成分を存在させる他の手法として、基材は例えばポリオレフィン系フィルムであって、基材被着面側にコロナ処理が施されていたり、プライマー層が設けられていたりしてもよい。また、基材の基材被着面と反対側の面には各種の塗膜が設けられていてもよい。 In addition, a component having one or more kinds selected from the group consisting of a carboxyl group and its ions and salts is provided on the surface of the substrate on the side of the pressure-sensitive adhesive layer (hereinafter also referred to as “substrate-coated surface”). Is preferably present. The above-mentioned component in the substrate and the component related to the pressure-sensitive adhesive layer (components used for forming the pressure-sensitive adhesive layer such as the component constituting the pressure-sensitive adhesive layer and the cross-linking agent are exemplified) chemically. By doing, possibility that peeling will generate | occur | produce between these can be reduced. The specific method for making such a component exist in a base-material adhesion surface is not specifically limited. For example, the base material itself is an ethylene- (meth) acrylic acid copolymer film, an ionomer resin film, etc., and the resin constituting the base material is selected from the group consisting of carboxyl groups, ions and salts thereof. Or you may have 2 or more types. As another method for causing the above components to be present on the substrate-adhered surface, the substrate is, for example, a polyolefin film, and the substrate-adhered surface side is subjected to corona treatment or a primer layer is provided. May be. Various coating films may be provided on the surface of the substrate opposite to the substrate deposition surface.
　基材の厚さは、粘着シートが所望の工程において適切に機能できる限り限定されないが、取扱性及び経済性の観点から、好ましくは５～１０００μｍ、より好ましくは１０～５００μｍ、更に好ましくは１２～２５０μｍ、より更に好ましくは１５～１５０μｍである。 The thickness of the substrate is not limited as long as the pressure-sensitive adhesive sheet can function properly in a desired process, but it is preferably 5 to 1000 μm, more preferably 10 to 500 μm, and still more preferably 12 to 12 from the viewpoint of handleability and economy. The thickness is 250 μm, more preferably 15 to 150 μm.
（５）剥離シート
　本実施形態に係る粘着シートは、被着体に粘着剤層を貼付するまでの間、粘着剤層を保護する目的で、粘着剤層の粘着面に、剥離シートが積層されていてもよい。剥離シートの構成は任意であり、プラスチックフィルムを剥離剤等により剥離処理したものが例示される。プラスチックフィルムの具体例としては、ポリエチレンテレフタレート、ポリブチレンテレフタレート、ポリエチレンナフタレート等のポリエステルフィルム、およびポリプロピレンやポリエチレン等のポリオレフィンフィルムが挙げられる。剥離剤としては、シリコーン系、フッ素系、長鎖アルキル系等を用いることができるが、これらの中で、安価で安定した性能が得られるシリコーン系が好ましい。剥離シートの厚さについては特に制限はないが、通常２０～２５０μｍ程度である。なお、かかる剥離シートは、凹部を形成するためのエンボスパターンが形成された剥離シートであってもよく、また、剥離面が平面であって、凹部が形成された後に粘着剤層を保護するために積層される剥離シートであってもよい。 (5) Release sheet The release sheet is laminated on the adhesive surface of the adhesive layer for the purpose of protecting the adhesive layer until the adhesive layer is applied to the adherend. It may be. The configuration of the release sheet is arbitrary, and examples include a release film of a plastic film with a release agent. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene. As the release agent, silicone-based, fluorine-based, long-chain alkyl-based, and the like can be used, and among these, a silicone-based material that is inexpensive and provides stable performance is preferable. The thickness of the release sheet is not particularly limited, but is usually about 20 to 250 μm. Such a release sheet may be a release sheet on which an emboss pattern for forming a recess is formed, and the release surface is flat, and the adhesive layer is protected after the recess is formed. It may be a release sheet laminated on the substrate.
（６）粘着シートの製造方法
　粘着シートの製造方法は、前述の粘着剤組成物から形成される粘着剤層を形成し、かつ、粘着剤層の粘着面に凹部を形成することができる方法であれば、詳細な方法は特に限定されない。一例を挙げれば、まず、凹部に対応するエンボスパターンが形成されたシートを用意し、かかるシートの表面を剥離処理することにより、エンボスパターンが形成された剥離シートを得る。次いで、前述の粘着剤組成物、および所望によりさらに溶媒または分散媒を含有する塗布用組成物を調製し、前述のようにして得たエンボスパターンを有する剥離シートの剥離処理面上に、ダイコーター、カーテンコーター、スプレーコーター、スリットコーター、ナイフコーター等によりその塗布用組成物を塗布して塗膜を形成し、当該塗膜を乾燥させることにより、粘着剤層と剥離シートからなる積層体を形成することができる。次いで、この積層体の粘着剤層における剥離シート側の面と反対側の面を基材に貼付して、粘着シートと剥離シートとの積層体を得てもよい。この積層体における剥離シートは工程材料として剥離してもよいし、電子部材や光学部材等の被着体に貼付するまでの間、粘着剤層を保護していてもよい。 (6) Manufacturing method of adhesive sheet The manufacturing method of an adhesive sheet is a method which can form the adhesive layer formed from the above-mentioned adhesive composition, and can form a recessed part in the adhesive surface of an adhesive layer. If there is, the detailed method is not particularly limited. As an example, first, a sheet on which an emboss pattern corresponding to the concave portion is formed is prepared, and a release sheet on which the emboss pattern is formed is obtained by performing a release process on the surface of the sheet. Next, a coating composition containing the pressure-sensitive adhesive composition described above and, if desired, further containing a solvent or a dispersion medium is prepared, and on the release-treated surface of the release sheet having an emboss pattern obtained as described above, a die coater Applying the coating composition by a curtain coater, spray coater, slit coater, knife coater, etc. to form a coating film, and drying the coating film forms a laminate composed of an adhesive layer and a release sheet can do. Next, a surface of the pressure-sensitive adhesive layer of the laminate that is opposite to the surface on the side of the release sheet may be attached to a substrate to obtain a laminate of the pressure-sensitive adhesive sheet and the release sheet. The release sheet in this laminate may be peeled off as a process material, or the adhesive layer may be protected until being attached to an adherend such as an electronic member or an optical member.
　この場合において、塗布用組成物は、塗布を行うことが可能であればその性状は特に限定されず、粘着剤層を形成するための成分を溶質として含有する場合もあれば、分散質として含有する場合もある。また、塗布用組成物が架橋剤を含有する場合には、上記の乾燥の条件（温度、時間など）を変えることにより、または加熱処理を別途設けることにより、塗膜内の（メタ）アクリル酸エステル重合体（Ａ）、（Ｂ１）または（Ｂ３）と架橋剤との架橋反応を進行させ、粘着剤層内に所望の存在密度で架橋構造を形成させればよい。この架橋反応を十分に進行させるために、上記の方法などによって基材に粘着剤層を積層させた後、得られた粘着シートを、例えば２３℃、相対湿度５０％の環境に数日間静置するといった養生を通常行う。
　なお、本明細書において粘着剤の「架橋」とは、粘着シートを被着体に貼着する前に行われる反応をいい、被着体に貼着する前とは、例えば、前述した粘着剤層を形成する段階が挙げられる。そのため、粘着剤の「架橋」は、後述する「硬化」とは明確に区別される。 In this case, the properties of the coating composition are not particularly limited as long as it can be applied, and may contain a component for forming the pressure-sensitive adhesive layer as a solute or a dispersoid. There is also a case. Further, when the coating composition contains a crosslinking agent, (meth) acrylic acid in the coating film can be obtained by changing the drying conditions (temperature, time, etc.) or by separately providing a heat treatment. What is necessary is just to advance the crosslinking reaction of ester polymer (A), (B1) or (B3), and a crosslinking agent, and to form a crosslinked structure in a desired presence density in an adhesive layer. In order to sufficiently proceed with this crosslinking reaction, after the pressure-sensitive adhesive layer is laminated on the substrate by the above-described method, the obtained pressure-sensitive adhesive sheet is allowed to stand for several days in an environment of 23 ° C. and 50% relative humidity, for example. It is usually done with curing.
In the present specification, “crosslinking” of the pressure-sensitive adhesive refers to a reaction performed before sticking the pressure-sensitive adhesive sheet to the adherend, and before sticking to the adherend is, for example, the pressure-sensitive adhesive described above. A step of forming a layer may be mentioned. Therefore, “crosslinking” of the pressure-sensitive adhesive is clearly distinguished from “curing” described later.
　粘着シートの別の製造方法として、エンボス加工に変えて、レーザ照射によるレーザ熱加工により行ってもよい。具体的には、前述したように粘着剤層と基材との積層体としての粘着シートを得たのち、粘着剤層の粘着面側からレーザを照射し、凹部を形成する。レーザ熱加工に用いるレーザの種類としては、炭酸ガス（ＣＯ２）レーザ、ＴＥＡ－ＣＯ２レーザ、ＹＡＧレーザ、ＵＶ－ＹＡＧレーザ、ＹＶＯ４レーザ、ＹＬＦレーザ等が挙げられるが、中でも、生産効率、コスト等の面から炭酸ガスレーザが好ましい。 As another manufacturing method of the pressure-sensitive adhesive sheet, it may be performed by laser thermal processing by laser irradiation instead of embossing. Specifically, as described above, after obtaining a pressure-sensitive adhesive sheet as a laminate of a pressure-sensitive adhesive layer and a substrate, a laser is irradiated from the pressure-sensitive adhesive side of the pressure-sensitive adhesive layer to form a recess. Examples of the laser used for laser thermal processing include carbon dioxide (CO 2 ) laser, TEA-CO 2 laser, YAG laser, UV-YAG laser, YVO 4 laser, YLF laser, etc. From the viewpoint of cost and the like, a carbon dioxide laser is preferable.
　なお、レーザ熱加工による貫通孔の形成には、一の貫通孔が形成されるまで一箇所に連続的にレーザ光を照射するバースト加工（バーストモード）と、複数箇所に順次レーザ光を照射して複数の貫通孔を均等に形成するサイクル加工（サイクルモード）とがあり、前者は熱効率の点で優れており、後者は被加工物に対する熱影響を低減できる点で優れているが、上記レーザ熱加工は、いずれのモードで行ってもよい。 In addition, through-hole formation by laser thermal processing is performed by burst processing (burst mode) in which laser light is continuously irradiated to one place until one through-hole is formed, and laser light is sequentially irradiated to a plurality of places. In addition, the former is superior in terms of thermal efficiency, and the latter is superior in terms of reducing the thermal effect on the workpiece. Thermal processing may be performed in any mode.
〔粘着シートの剥離方法，加工物の製造方法〕
　以上述べた粘着シートを用い、粘着シートと、粘着剤層の粘着面に貼着された被着体とを剥離する方法について、図４を参照しながら以下に説明する。 [Peeling method of adhesive sheet, manufacturing method of processed products]
A method of peeling the pressure-sensitive adhesive sheet and the adherend adhered to the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer using the pressure-sensitive adhesive sheet described above will be described below with reference to FIG.
（１）貼着工程
　まず、本実施形態の剥離方法に付すにあたり、図４（ａ）に示すように、被着体としてのワークＷを、粘着シート１が備える粘着剤層２の粘着面Ｐに、あらかじめ貼着する。前述したとおり、粘着剤層２の粘着面Ｐには、凹部３が形成されており、かかる凹部３とワークＷとの間に独立した空間Ｃが生じるように、ワークＷを粘着シート１に貼着する。ここで、空間Ｃが独立しているとは、粘着面Ｐにおいて被着体に貼着されている部分の端部Ｅに、空間Ｃが連通していないことを意味する。空間Ｃが独立していることにより、後述する剥離工程において、減圧処理により空間Ｃを膨張させることができる。 (1) Adhesion process First, when attaching | subjecting to the peeling method of this embodiment, as shown to Fig.4 (a), the adhesive surface P of the adhesive layer 2 with which the adhesive sheet 1 is equipped with the workpiece | work W as a to-be-adhered body. Adhere in advance. As described above, the concave surface 3 is formed on the adhesive surface P of the pressure-sensitive adhesive layer 2, and the work W is pasted on the pressure-sensitive adhesive sheet 1 so that an independent space C is formed between the concave portion 3 and the work W. To wear. Here, that the space C is independent means that the space C does not communicate with the end E of the portion of the adhesive surface P that is attached to the adherend. Since the space C is independent, the space C can be expanded by a decompression process in a peeling step described later.
　本実施形態に係る剥離方法の対象となるワークＷとしては、例えば、半導体ウェハ、半導体パッケージ、多層基板、セラミックグリーンシート積層体、一括封止モジュール等の電子部材；液晶ディスプレイ部材、有機ＥＬディスプレイ部材、光学フィルター、偏光板、位相差板等の光学部材などが挙げられる。 Examples of the workpiece W to be subjected to the peeling method according to this embodiment include electronic members such as a semiconductor wafer, a semiconductor package, a multilayer substrate, a ceramic green sheet laminate, a batch sealing module; a liquid crystal display member, and an organic EL display member. And optical members such as an optical filter, a polarizing plate, and a retardation plate.
　ワークＷと粘着シート１との貼着は、大気圧下で行ってもよく、後述する圧力制御装置１０により雰囲気圧力が制御されたチャンバー内で行ってもよい。ここで、貼着工程が行われる大気圧またはチャンバー内の雰囲気圧力は、その後の工程における空間Ｃ中の気体の圧力に相当し、かかる雰囲気圧力を適宜調整したうえで貼着工程を行うと、減圧処理における気体の膨張量を制御することが容易になる。 The attachment of the workpiece W and the pressure-sensitive adhesive sheet 1 may be performed under atmospheric pressure, or may be performed in a chamber in which the atmospheric pressure is controlled by the pressure control device 10 described later. Here, the atmospheric pressure in which the sticking process is performed or the atmospheric pressure in the chamber corresponds to the pressure of the gas in the space C in the subsequent process, and after performing the sticking process after appropriately adjusting the atmospheric pressure, It becomes easy to control the amount of gas expansion in the decompression process.
（２）加工工程
　貼着工程により粘着シート１に貼着されたワークＷは、粘着シート１に貼着された状態で、各種の加工工程に付すことができる（図４（ｂ））。加工工程の例としては、ワークＷが半導体ウェハであれば、バックグラインド工程、回路形成工程、ダイシング工程やダイソート工程等が挙げられ、ワークＷが表示装置構成部材であれば、積層工程や移送工程等が挙げられる。これら各種加工工程により、ワークＷは加工物Ｗ’に加工される。ここで、粘着シート１は、ワークＷの加工工程の後、後述するようにワークＷから剥離されるため、加工工程の間ワークＷを仮固定するために用いられるということができる。 (2) Processing process The workpiece | work W stuck on the adhesive sheet 1 by the sticking process can be attached | subjected to various processing processes in the state stuck on the adhesive sheet 1 (FIG.4 (b)). Examples of processing steps include a back grinding process, a circuit forming process, a dicing process, a die sort process, and the like if the work W is a semiconductor wafer, and a laminating process and a transfer process if the work W is a display device component. Etc. Through these various processing steps, the workpiece W is processed into a workpiece W ′. Here, since the adhesive sheet 1 is peeled from the workpiece W as described later after the processing step of the workpiece W, it can be said that it is used for temporarily fixing the workpiece W during the processing step.
（３）剥離工程
　次に、加工物Ｗ’が貼着された状態の粘着シート１を、圧力制御装置１０のチャンバー内に載置する（図４（ｃ））。ここで、後述する減圧処理において空間Ｃを効果的に膨張させるため、加工物Ｗ’が貼着された状態の粘着シート１を、加工物Ｗ’が粘着シート１の下側となるように、チャンバー内に載置することが好ましい。ただし、加工物Ｗ’の重さが十分に小さい等（特に、加工物Ｗ’が粘着シート１よりも軽い場合）、減圧処理において空間Ｃを膨張させることができる場合は、加工物Ｗ’が粘着シート１の上側となるように、チャンバー内に載置してもよい。 (3) Peeling step Next, the pressure-sensitive adhesive sheet 1 in a state where the workpiece W ′ is stuck is placed in the chamber of the pressure control device 10 (FIG. 4C). Here, in order to effectively expand the space C in the decompression process to be described later, the pressure-sensitive adhesive sheet 1 in a state in which the workpiece W ′ is adhered, so that the workpiece W ′ is below the pressure-sensitive adhesive sheet 1, It is preferable to place in the chamber. However, when the weight of the workpiece W ′ is sufficiently small (particularly when the workpiece W ′ is lighter than the pressure-sensitive adhesive sheet 1), the workpiece W ′ can be expanded when the space C can be expanded in the decompression process. You may mount in a chamber so that it may become the upper side of the adhesive sheet 1. FIG.
　続いて、チャンバー内圧力を低下させる（減圧処理，図４（ｄ））。すると、空間Ｃ中の気体の圧力は、チャンバー内圧力に比べて相対的に高い状態となるため、かかる空間Ｃ中の気体が体積膨張することにより、粘着剤層２内において空間Ｃを膨張させるような圧力が粘着剤層２に付与される。 Subsequently, the pressure in the chamber is reduced (decompression treatment, FIG. 4 (d)). Then, since the pressure of the gas in the space C is relatively higher than the pressure in the chamber, the space C expands in the pressure-sensitive adhesive layer 2 by volume expansion of the gas in the space C. Such pressure is applied to the pressure-sensitive adhesive layer 2.
　このような圧力として、少なくとも空間Ｃには、縦方向（粘着剤層２の粘着面Ｐの法線方向）に沿った方向で膨張させる向きの圧力が付与されることになる。ここで、粘着剤層２が複数の凹部３を有することにより、空間Ｃが複数形成されている場合には、一つの空間Ｃに対して付与される横方向（粘着剤層２における粘着面Ｐの平面方向）の圧力が、その空間Ｃに隣接する空間Ｃにおける横方向の圧力により相殺される場合、縦方向の圧力が相殺されずに残り、空間Ｃの縦方向へ膨張させようとする力がより顕著なものとなるため、好ましい。 As such a pressure, at least the space C is given a pressure in a direction in which it expands in a direction along the vertical direction (the normal direction of the adhesive surface P of the adhesive layer 2). Here, when a plurality of spaces C are formed by having the plurality of recesses 3 in the pressure-sensitive adhesive layer 2, the lateral direction applied to one space C (the pressure-sensitive adhesive surface P in the pressure-sensitive adhesive layer 2). Force in the vertical direction of the space C, the pressure in the vertical direction remains without being canceled, and the pressure in the space C adjacent to the space C cancels the pressure in the vertical direction. Is more preferable because it becomes more prominent.
　上記減圧処理は、貼付環境の雰囲気圧力よりも低くすることが好ましく、チャンバー内の雰囲気圧力が貼付環境の雰囲気圧力よりも１０ｋＰａ以上の差を有するように低くすることがより好ましく、当該雰囲気圧力の差が３０ｋＰａ以上とすることがさらに好ましく、５０ｋＰａ以上とすることがよりさらに好ましく、８０ｋＰａ以上とすることがさらに好ましく、９０ｋＰａ以上とすることが特に好ましい。貼付環境の雰囲気圧力よりも低くなるように上記減圧処理を行うことにより、空間Ｃ中の気体をより効果的に膨張させることができる。なお、チャンバー内の圧力の下限値は特に限定されないが、技術的な観点から、通常は１０－７Ｐａ以上であり、好ましくは１０－５Ｐａ以上、より好ましくは１０－１Ｐａ以上、よりさらに好ましくは１０Ｐａ以上、よりさらに好ましくは１００Ｐａ以上、特に好ましくは１０００Ｐａ以上である。 The pressure reduction treatment is preferably lower than the atmospheric pressure of the pasting environment, more preferably lower so that the atmospheric pressure in the chamber has a difference of 10 kPa or more than the atmospheric pressure of the pasting environment. The difference is more preferably 30 kPa or more, still more preferably 50 kPa or more, further preferably 80 kPa or more, and particularly preferably 90 kPa or more. By performing the pressure reduction process so as to be lower than the atmospheric pressure of the pasting environment, the gas in the space C can be expanded more effectively. The lower limit value of the pressure in the chamber is not particularly limited, but is usually 10 −7 Pa or more, preferably 10 −5 Pa or more, more preferably 10 −1 Pa or more, and even more, from a technical viewpoint. Preferably it is 10 Pa or more, More preferably, it is 100 Pa or more, Especially preferably, it is 1000 Pa or more.
　かかる減圧処理の結果、図４（ｄ）に示されるように、空間Ｃの膨張により粘着剤の縦方向へ基材を押し上げる力が、被着体との粘着力を上回る場合、その箇所から粘着剤層２は加工物Ｗ’から一部または全て剥離する（図４（ｅ））。粘着剤層２が複数の凹部３を有することにより、空間Ｃが複数形成されるため、膨張する箇所が増えて結果的に剥離のきっかけとなる箇所が増えるため好ましい。なお、粘着剤層２は硬質であっても軟質であってもよい。粘着剤層２が比較的硬質である場合は、図４（ｄ）に示すように、空間Ｃおよび粘着剤層２の変形がほとんど認められない状態で、粘着剤層２と加工物Ｗ’との界面の剥離が、空間Ｃ側から進行していく。これは、気体の膨張による圧力が、粘着剤層２と加工物Ｗ’とで構成される空間Ｃの内壁のうち、比較的脆弱な部分である粘着剤層２と加工物Ｗ’との界面に集中しやすくなるためであると考えられる。一方、粘着剤層２が比較的軟質である場合は、空間Ｃおよび粘着剤層２が縦方向に変形した後に、図４（ｅ）に示すように粘着剤層２と加工物Ｗ’とが剥離する。このようにして、粘着剤層２の加工物Ｗ’への粘着力が低下する。これにより、粘着シート１と加工物Ｗ’とを容易に剥離させることができる。ここで、粘着シート１と加工物Ｗ’とは、図４（ｅ）の状態でそのまま剥離させることもできるし、例えば、加工物Ｗ’が粘着シート１の上側となるようにチャンバー内に載置して減圧した場合は、減圧したチャンバー内で加工物Ｗ’と粘着シート１とを１８０°反転させることで、加工物Ｗ’の自重により粘着シート１と加工物Ｗ’とを剥離させることもできる。 As a result of the decompression process, as shown in FIG. 4D, when the force for pushing up the base material in the longitudinal direction of the adhesive due to the expansion of the space C exceeds the adhesive force with the adherend, the adhesive is applied from that location. The agent layer 2 is partially or entirely peeled from the workpiece W ′ (FIG. 4E). Since the pressure-sensitive adhesive layer 2 has a plurality of recesses 3, a plurality of spaces C are formed, and therefore, the number of expanding portions increases, resulting in an increase in the number of locations that cause peeling. The pressure-sensitive adhesive layer 2 may be hard or soft. When the pressure-sensitive adhesive layer 2 is relatively hard, as shown in FIG. 4D, the pressure-sensitive adhesive layer 2 and the workpiece W ′ The peeling of the interface proceeds from the space C side. This is because the pressure due to the expansion of the gas is an interface between the pressure-sensitive adhesive layer 2 and the workpiece W ′, which is a relatively fragile portion of the inner wall of the space C constituted by the pressure-sensitive adhesive layer 2 and the workpiece W ′. This is thought to be easier to concentrate on. On the other hand, when the pressure-sensitive adhesive layer 2 is relatively soft, after the space C and the pressure-sensitive adhesive layer 2 are deformed in the vertical direction, the pressure-sensitive adhesive layer 2 and the workpiece W ′ are formed as shown in FIG. Peel off. In this way, the adhesive strength of the pressure-sensitive adhesive layer 2 to the workpiece W ′ is reduced. Thereby, the adhesive sheet 1 and the workpiece W ′ can be easily peeled off. Here, the pressure-sensitive adhesive sheet 1 and the workpiece W ′ can be peeled as they are in the state shown in FIG. 4E. For example, the pressure-sensitive adhesive sheet 1 is placed in the chamber so that the workpiece W ′ is on the upper side of the pressure-sensitive adhesive sheet 1. When the pressure is reduced by placing the workpiece W ′ and the pressure-sensitive adhesive sheet 1 in 180 ° in a reduced pressure chamber, the pressure-sensitive adhesive sheet 1 and the workpiece W ′ are peeled off by the weight of the workpiece W ′. You can also.
　また、粘着剤層２を形成する粘着剤組成物が活性エネルギー線硬化性または熱硬化性を有する場合は、前述した加工工程の後であって、減圧処理の前または後に、活性エネルギー線照射または加熱により、粘着剤層２を硬化させることが好ましい。ここで、減圧処理の前に粘着剤層２を硬化させる場合、減圧処理の段階で粘着剤層２が比較的硬質となっているため、前述したとおり、空間Ｃおよび粘着剤層２の変形をほとんど起こさずに、粘着剤層２と加工物Ｗ’との界面の剥離が、空間Ｃ側から進行し、粘着剤層２と加工物Ｗ’と粘着力を低下させることができる。一方、減圧処理の後に粘着剤層２を硬化させると、減圧処理の段階では粘着剤層２は比較的軟質であるため、空間Ｃおよび粘着剤層２を変形（図４（ｄ））させた後、粘着剤層２を硬化させることでさらに粘着力を低下させることができ、やはり粘着剤層２と加工物Ｗ’との剥離が容易になる。
　なお、本明細書において粘着剤の「硬化」とは、粘着シート１を被着体（ワークＷ，加工物Ｗ’）に貼着したのちに行われる反応をいう。そのため、例えば前述した粘着剤の「架橋」とは明確に区別される。 Further, when the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer 2 has active energy ray curable or thermosetting property, the active energy ray irradiation or after the above-described processing step and before or after the decompression treatment. It is preferable to cure the pressure-sensitive adhesive layer 2 by heating. Here, when the pressure-sensitive adhesive layer 2 is cured before the pressure reduction treatment, the pressure-sensitive adhesive layer 2 is relatively hard at the stage of the pressure reduction treatment. Peeling of the interface between the pressure-sensitive adhesive layer 2 and the workpiece W ′ progresses from the space C side almost without causing the pressure-sensitive adhesive layer 2 and the workpiece W ′ and the adhesive force to be reduced. On the other hand, when the pressure-sensitive adhesive layer 2 is cured after the pressure reduction treatment, the space C and the pressure-sensitive adhesive layer 2 are deformed (FIG. 4D) because the pressure-sensitive adhesive layer 2 is relatively soft at the stage of the pressure reduction treatment. Thereafter, the pressure-sensitive adhesive layer 2 can be cured to further reduce the adhesive force, and the pressure-sensitive adhesive layer 2 and the workpiece W ′ can be easily separated from each other.
In this specification, “curing” of the pressure-sensitive adhesive refers to a reaction performed after the pressure-sensitive adhesive sheet 1 is adhered to an adherend (work W, workpiece W ′). Therefore, for example, it is clearly distinguished from the above-mentioned “crosslinking” of the pressure-sensitive adhesive.
　粘着剤組成物が活性エネルギー線硬化性を有する場合、粘着剤組成物を硬化させるための活性エネルギー線としては、電離放射線、すなわち、紫外線、Ｘ線、電子線などが挙げられる。これらのうちでも、比較的照射設備の導入の容易な紫外線が好ましい。 When the pressure-sensitive adhesive composition has active energy ray curability, examples of the active energy ray for curing the pressure-sensitive adhesive composition include ionizing radiation, that is, ultraviolet rays, X-rays, and electron beams. Among these, ultraviolet rays that are relatively easy to introduce irradiation equipment are preferable.
　電離放射線として紫外線を用いる場合には、取り扱いの容易さから波長２００～３８０ｎｍ程度の紫外線を含む近紫外線を用いればよい。光量としては、活性エネルギー線硬化性粘着剤組成物が有する活性エネルギー線硬化性基の種類や粘着剤層２の厚さに応じて適宜選択すればよく、通常５０～１５００ｍＪ／ｃｍ２程度であり、２００～１０００ｍＪ／ｃｍ２が好ましく、３００～８００ｍＪ／ｃｍ２がより好ましい。また、紫外線照度は、通常５０～１５００ｍＷ／ｃｍ２程度であり、２００～１０００ｍＷ／ｃｍ２が好ましく、３００～８００ｍＷ／ｃｍ２がより好ましい。紫外線源としては特に制限はなく、例えば無電極ランプ、高圧水銀ランプ、メタルハライドランプ、ＵＶ－ＬＥＤなどが用いられる。 When ultraviolet rays are used as the ionizing radiation, near ultraviolet rays including ultraviolet rays having a wavelength of about 200 to 380 nm may be used for ease of handling. The amount of light may be appropriately selected according to the type of active energy ray-curable group possessed by the active energy ray-curable pressure-sensitive adhesive composition and the thickness of the pressure-sensitive adhesive layer 2, and is usually about 50 to 1500 mJ / cm 2 . 200 to 1000 mJ / cm 2 is preferable, and 300 to 800 mJ / cm 2 is more preferable. The ultraviolet illumination is usually 50 ~ 1500mW / cm 2 or so, preferably 200 ~ 1000mW / cm 2, more preferably 300 ~ 800mW / cm 2. The ultraviolet light source is not particularly limited, and for example, an electrodeless lamp, a high-pressure mercury lamp, a metal halide lamp, a UV-LED, or the like is used.
　電離放射線として電子線を用いる場合には、その加速電圧については、活性エネルギー線硬化性粘着剤組成物が有する活性エネルギー線硬化性基の種類や粘着剤層２の厚さに応じて適宜選定すればよく、通常加速電圧１０～１０００ｋＶ程度であることが好ましい。また、照射線量は、活性エネルギー線硬化性粘着剤組成物が適切に硬化する範囲に設定すればよく、通常１０～１０００ｋｒａｄの範囲で選定される。電子線源としては、特に制限はなく、例えばコッククロフトワルトン型、バンデグラフ型、共振変圧器型、絶縁コア変圧器型、あるいは直線型、ダイナミトロン型、高周波型などの各種電子線加速器を用いることができる。 When an electron beam is used as the ionizing radiation, the acceleration voltage is appropriately selected according to the type of active energy ray-curable group possessed by the active energy ray-curable adhesive composition and the thickness of the adhesive layer 2. Usually, the acceleration voltage is preferably about 10 to 1000 kV. The irradiation dose may be set within a range where the active energy ray-curable pressure-sensitive adhesive composition is appropriately cured, and is usually selected within a range of 10 to 1000 krad. The electron beam source is not particularly limited. For example, various electron beam accelerators such as a cockcroft Walton type, a bandegraph type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type may be used. it can.
　粘着剤組成物を効果的に硬化させる観点から、これらの活性エネルギー線は、粘着シート１における粘着面Ｐ（加工物Ｗ’が貼着された面）とは反対の面側から照射することが好ましい。 From the viewpoint of effectively curing the pressure-sensitive adhesive composition, these active energy rays may be irradiated from the surface opposite to the pressure-sensitive adhesive surface P (the surface on which the workpiece W ′ is adhered) in the pressure-sensitive adhesive sheet 1. preferable.
　一方、粘着剤組成物が熱硬化性を有する場合、粘着剤組成物を硬化させるための加熱手段としては、例えば、ホットプレート、熱風乾燥機、近赤外線ランプなどの適当な手段を採用することができる。加熱条件は、粘着剤層２の熱硬化に要する加熱温度、所望の剥離性、ワークＷや加工物Ｗ’等の耐熱性、加熱手段等により適宜設定される。一般的な加熱条件として、例えばホットプレートを用いる場合、温度８０～２５０℃、加熱時間５秒～６０秒間等が例示される。 On the other hand, when the pressure-sensitive adhesive composition has thermosetting properties, as a heating means for curing the pressure-sensitive adhesive composition, for example, an appropriate means such as a hot plate, a hot air dryer, or a near infrared lamp can be adopted. it can. The heating conditions are appropriately set depending on the heating temperature required for the thermosetting of the pressure-sensitive adhesive layer 2, the desired peelability, the heat resistance of the workpiece W and the workpiece W ', the heating means, and the like. As general heating conditions, for example, when a hot plate is used, a temperature of 80 to 250 ° C., a heating time of 5 seconds to 60 seconds, and the like are exemplified.
　以上述べた本実施形態に係る粘着シートの剥離方法によれば、粘着シート１の粘着剤層２が粘着面Ｐに有する凹部３と、被着体（ワークＷ，加工物Ｗ’）との間に空間Ｃを形成し、かかる空間Ｃ中の気体を膨張させる減圧処理により、粘着シート１の被着体への粘着力を低下させる。かかる方法によれば、減圧処理により気体を膨張させるとの新規な作用機構により、所望のタイミングで粘着力を低下させることができ、これにより粘着シートと被着体との剥離を容易にすることができる。 According to the pressure-sensitive adhesive sheet peeling method according to the present embodiment described above, the space between the concave portion 3 of the pressure-sensitive adhesive layer 2 of the pressure-sensitive adhesive sheet 1 on the pressure-sensitive adhesive surface P and the adherend (work W, workpiece W ′). The pressure-sensitive adhesive treatment of the pressure-sensitive adhesive sheet 1 to the adherend is reduced by a decompression process that forms a space C in the space C and expands the gas in the space C. According to such a method, the adhesive force can be reduced at a desired timing by a novel mechanism of expanding the gas by the decompression process, thereby facilitating the peeling between the adhesive sheet and the adherend. Can do.
　ここで、活性エネルギー線硬化性または熱硬化性のみを利用して粘着剤層２の粘着力を低下させる場合は、硬化反応（すなわち化学反応）を十分に進行させるため、材料の選択が限定されてしまう。しかし、本実施形態によれば、減圧処理による気体の膨張により粘着力を低下させることができるため、活性エネルギー線硬化性もしくは熱硬化性を全く利用しないか、部分的に利用すればよいこととなるため、粘着剤層２を構成する材料の自由度を大きいものとすることができる。また、熱硬化性を利用して粘着剤層２の粘着力を低下させる場合は、ワークＷの加工工程の中に加熱する工程が含まれていると、粘着剤層２の粘着力が低下し加工工程中のワークＷの仮固定が十分に行えないおそれがあるが、本実施形態においては、熱硬化性を全く利用しないか、または部分的にのみ利用すればよいため、ワークＷの加工工程の中に加熱工程が含まれる場合であっても、ワークＷを十分に仮固定することができる。 Here, when the adhesive force of the pressure-sensitive adhesive layer 2 is reduced using only active energy ray curable or thermosetting, the selection of materials is limited because the curing reaction (that is, chemical reaction) is sufficiently advanced. End up. However, according to the present embodiment, the adhesive force can be reduced by the expansion of the gas due to the decompression process, so that the active energy ray curable property or thermosetting property is not used at all or only partially used. Therefore, the freedom degree of the material which comprises the adhesive layer 2 can be made large. Moreover, when reducing the adhesive strength of the adhesive layer 2 using thermosetting, if the process of heating the workpiece W is included, the adhesive strength of the adhesive layer 2 decreases. Although there is a possibility that the temporary fixing of the workpiece W during the processing step may not be sufficiently performed, in the present embodiment, the thermosetting property is not used at all or only partially used. Even if a heating process is included in the workpiece, the workpiece W can be sufficiently temporarily fixed.
　以上説明した実施形態は、本発明の理解を容易にするために記載されたものであって、本発明を限定するために記載されたものではない。したがって、上記実施形態に開示された各要素は、本発明の技術的範囲に属する全ての設計変更、均等物および均等方法をも含む趣旨である。 The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes, equivalents, and equivalent methods belonging to the technical scope of the present invention.
　例えば、上記粘着シート１における基材４と粘着剤層２との間には、他の層が介在していてもよい。 For example, another layer may be interposed between the base material 4 and the pressure-sensitive adhesive layer 2 in the pressure-sensitive adhesive sheet 1.
　また、別の実施形態においては、粘着シートは、基材を備えず、粘着剤層のみからなる両面粘着シートであってもよい。例えば、他の一実施形態においては、第１の粘着面および第２の粘着面を有する両面粘着シートと、第１の粘着面に貼着された第１の被着体とを剥離する方法とすることができる。第２の粘着面には、例えば、第２の被着体が貼着されていてもよい。この場合において、前述した実施形態と同様に、第１の粘着面には凹部が形成されており、第１の被着体はかかる凹部により独立した空間が生じるように粘着剤層に貼着される。かかる第１の被着体ならびに粘着シート（および第２の被着体）に対し減圧処理を行うことにより、空間中の気体が膨張し、第１の被着体に対する両面粘着シートの粘着力が低下することにより、第１の被着体と粘着シートとを剥離させることができる。 In another embodiment, the pressure-sensitive adhesive sheet may be a double-sided pressure-sensitive adhesive sheet comprising only a pressure-sensitive adhesive layer without a base material. For example, in another embodiment, a method of peeling a double-sided pressure-sensitive adhesive sheet having a first pressure-sensitive adhesive surface and a second pressure-sensitive adhesive surface, and a first adherend adhered to the first pressure-sensitive adhesive surface; can do. For example, a second adherend may be attached to the second adhesive surface. In this case, as in the above-described embodiment, the first adhesive surface has a recess, and the first adherend is adhered to the adhesive layer so that an independent space is created by the recess. The By performing a decompression process on the first adherend and the pressure-sensitive adhesive sheet (and the second adherend), the gas in the space expands, and the adhesive force of the double-sided pressure-sensitive adhesive sheet on the first adherend is increased. By lowering, the first adherend and the pressure-sensitive adhesive sheet can be peeled off.
　以下、実施例等により本発明をさらに具体的に説明するが、本発明の範囲はこれらの実施例等に限定されるものではない。 Hereinafter, the present invention will be described more specifically with reference to examples and the like, but the scope of the present invention is not limited to these examples and the like.
〔実施例１〕
（ａ）剥離シートの作成
　ポリエチレンテレフタレートフィルム（東レ株式会社製，製品名「ルミラー」，厚さ７５μｍ）に図５（ａ）の模様となるようにエンボス加工を施してエンボスフィルム（１）を得た。エンボスフィルム（１）のエンボス加工面に剥離剤として、剥離シート（リンテック株式会社製，製品名「ＳＰ－ＰＥＴ３８１１３０」）の剥離剤と同じ組成の剥離剤を、乾燥後の厚さが０．１μｍとなるようにマイヤーバーで塗布し、１３０℃で３０秒間乾燥させて、表面にエンボスパターンを有する剥離シート（１）を作製した。 [Example 1]
(A) Creation of release sheet An embossed film (1) is obtained by embossing a polyethylene terephthalate film (manufactured by Toray Industries, Inc., product name “Lumirror”, thickness 75 μm) to the pattern of FIG. It was. As a release agent on the embossed surface of the embossed film (1), a release agent having the same composition as the release agent of the release sheet (product name “SP-PET381130”, manufactured by Lintec Corporation) is 0.1 μm in thickness after drying. The release sheet (1) having an embossed pattern on the surface was prepared by coating with a Meyer bar so that
（ｂ）粘着剤の調製
　ｎ－ブチルアクリレート５２質量部、メチルメタクリレート２０質量部および２－ヒドロキシエチルアクリレート２８質量部を共重合してなる（メタ）アクリル酸エステル共重合体（メタクリロイルオキシエチルイソシアネート（ＭＯＩ）を（メタ）アクリル酸エステル共重合体のヒドロキシ基１００当量に対して９０当量を添加して反応、重量平均分子量５８万、固形分濃度３５質量％）１００質量部（固形分質量部）と、エネルギー線硬化型ウレタンアクリレート系オリゴマー（日本合成化学工業株式会社製，製品名「紫光ＵＶ－６１００Ｂ」，質量平均分子量６７００，ガラス転移温度０℃）１００質量部（固形分）と、イソシアネート系架橋剤（東ソー株式会社製，製品名「コロネートＬ」，固形分濃度７５質量％）０．４質量部（固形分質量部）と、光重合開始剤として１－ヒドロキシ－シクロヘキシル－フェニル－ケトン（ＢＡＳＦ社製，製品名「イルガキュア１８４」）３．０質量部とを混合し、エネルギー線硬化型粘着剤を調製した。 (B) Preparation of pressure-sensitive adhesive (meth) acrylic acid ester copolymer (methacryloyloxyethylisocyanate) obtained by copolymerizing 52 parts by mass of n-butyl acrylate, 20 parts by mass of methyl methacrylate and 28 parts by mass of 2-hydroxyethyl acrylate MOI) is reacted by adding 90 equivalents to 100 equivalents of the hydroxy group of the (meth) acrylic acid ester copolymer, weight average molecular weight 580,000, solid concentration 35% by mass) 100 parts by mass (solids part by mass) And 100 parts by mass (solid content) of an energy ray curable urethane acrylate oligomer (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., product name “purple light UV-6100B”, mass average molecular weight 6700, glass transition temperature 0 ° C.), isocyanate type Cross-linking agent (manufactured by Tosoh Corporation, product name “Coronate L”, solid concentration 75 mass) %) 0.4 part by mass (solid part part by mass) and 3.0 part by mass of 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF, product name “Irgacure 184”) as a photopolymerization initiator Then, an energy ray curable pressure-sensitive adhesive was prepared.
　ここで、ポリスチレン換算重量平均分子量は、ゲル浸透クロマトグラフ装置（東ソー株式会社製，製品名「ＨＬＣ－８０２０」）を用い、下記条件にて測定（ＧＰＣ測定）した標準ポリスチレン換算値である。 Here, the polystyrene equivalent weight average molecular weight is a standard polystyrene equivalent value measured (GPC measurement) under the following conditions using a gel permeation chromatograph (manufactured by Tosoh Corporation, product name “HLC-8020”).
＜ＧＰＣ測定条件＞
・カラム　　：「ＴＳＫ　ｇｕａｒｄ　ｃｏｌｕｍｎ　ＨＸＬ－Ｌ」、「ＴＳＫ　ｇｅｌ　Ｇ２５００ＨＸＬ」、「ＴＳＫ　ｇｅｌ　Ｇ２０００ＨＸＬ」、「ＴＳＫ　ｇｅｌ　Ｇ１０００ＨＸＬ」（いずれも東ソー株式会社製）を順次連結したもの
・カラム温度：４０℃
・展開溶媒　：テトラヒドロフラン
・流速　　　：１．０ｍＬ／ｍｉｎ
・検出器　　：示差屈折計
・標準試料　：ポリスチレン <GPC measurement conditions>
Column: “TSK guard column HXL-L”, “TSK gel G2500HXL”, “TSK gel G2000HXL”, “TSK gel G1000HXL” (all manufactured by Tosoh Corporation) • Column temperature: 40 ° C.
・ Developing solvent: Tetrahydrofuran ・ Flow rate: 1.0 mL / min
・ Detector: Differential refractometer ・ Standard sample: Polystyrene
（ｃ）粘着シートの作製
　上記（ａ）で作成した剥離シートの剥離処理面に、上記（ｂ）で調製したエネルギー線硬化型粘着剤を、乾燥後の厚さがエンボスの頂点から２５μｍとなるようにナイフコーターで塗布し、１１０℃で２分間乾燥させて粘着剤層を形成した。得られた粘着剤層に、基材としてのポリエチレンテレフタレートフィルム（三菱樹脂株式会社製，製品名「ダイアホイル」，厚さ５０μｍ）を貼り合わせ、その後、２３℃、相対湿度５０％の条件下で７日間シーズニングして、これを粘着シートとした。 (C) Production of pressure-sensitive adhesive sheet On the release-treated surface of the release sheet created in (a) above, the energy ray-curable pressure-sensitive adhesive prepared in (b) above has a thickness after drying of 25 μm from the top of the emboss. Thus, it was applied with a knife coater and dried at 110 ° C. for 2 minutes to form an adhesive layer. A polyethylene terephthalate film (manufactured by Mitsubishi Plastics Co., Ltd., product name “Diafoil”, thickness 50 μm) as a base material is bonded to the obtained pressure-sensitive adhesive layer, and then, under conditions of 23 ° C. and 50% relative humidity. This was seasoned for 7 days and used as an adhesive sheet.
〔実施例２〕
　ポリエチレンテレフタレートフィルム（東レ株式会社製，製品名「ルミラー」，厚さ７５μｍ）に図６（ａ）の模様となるようにエンボス加工を施してエンボスフィルム（２）を得た。エンボスフィルム（２）のエンボス加工面に剥離剤として、剥離シート（リンテック株式会社製，製品名「ＳＰ－ＰＥＴ３８１１３０」）の剥離剤と同じ組成の剥離剤を、乾燥後の厚さが０．１μｍとなるようにマイヤーバーで塗布し、１３０℃で３０秒間乾燥させて、表面にエンボスパターンを有する剥離シート（２）を作製した。
　得られた剥離シート（２）を用いた以外は実施例１と同様にして、粘着シートを作製した。 [Example 2]
An embossed film (2) was obtained by embossing a polyethylene terephthalate film (manufactured by Toray Industries, Inc., product name “Lumirror”, thickness 75 μm) so as to have the pattern of FIG. As the release agent on the embossed surface of the embossed film (2), a release agent having the same composition as the release agent of the release sheet (product name “SP-PET381130”, manufactured by Lintec Corporation) is 0.1 μm in thickness after drying. The release sheet (2) having an embossed pattern on the surface was prepared by applying with a Meyer bar so as to become and drying at 130 ° C. for 30 seconds.
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the obtained release sheet (2) was used.
〔実施例３〕
　ポリエチレンテレフタレートフィルム（東レ株式会社製，製品名「ルミラー」，厚さ７５μｍ）に図７（ａ）の模様となるようにエンボス加工を施してエンボスフィルム（３）を得た。エンボスフィルム（３）のエンボス加工面に剥離剤として、剥離シート（リンテック株式会社製，製品名「ＳＰ－ＰＥＴ３８１１３０」）の剥離剤と同じ組成の剥離剤を、乾燥後の厚さが０．１μｍとなるようにマイヤーバーで塗布し、１３０℃で３０秒間乾燥させて、表面にエンボスパターンを有する剥離シート（３）を作製した。
　得られた剥離シート（３）を用いた以外は実施例１と同様にして、粘着シートを作製した。 Example 3
An embossed film (3) was obtained by embossing a polyethylene terephthalate film (manufactured by Toray Industries, Inc., product name “Lumirror”, thickness 75 μm) so as to have the pattern of FIG. As the release agent on the embossed surface of the embossed film (3), a release agent having the same composition as the release agent of the release sheet (product name “SP-PET381130”, manufactured by Lintec Corporation) is 0.1 μm in thickness after drying. The release sheet (3) having an embossed pattern on the surface was prepared by coating with a Meyer bar so that
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the obtained release sheet (3) was used.
＜エンボス面の凸部面積率の測定＞
　各実施例にて用いた剥離シートのエンボス面（エンボスパターンを有する剥離処理面）を、デジタル顕微鏡（倍率２０～５０倍）を用いて、任意に選択した範囲を上面から垂直方向に撮影し、画像を取得した。
　なお、当該撮影に際し、より具体的には、垂直方向から目視にて接着面に該当する側（非凸部）に焦点を当てて撮影した。
　そして、取得した画像において、所定の長方形で囲まれた領域Ｔを１領域任意に選択し、これを「領域Ｔの画像」とした。ここで、領域Ｔの選択においては、エンボスパターンの認識のしやすさと規則性を考慮し、剥離シート（１）では縦４ｍｍ×横５ｍｍを、剥離シート（２）では縦８ｍｍ×横１０ｍｍを、剥離シート（３）では縦２ｍｍ×横２．５ｍｍを、それぞれ選択した。
　なお、デジタル顕微鏡の撮影条件は以下のとおりである。 <Measurement of convex area ratio of embossed surface>
Using a digital microscope (magnification 20 to 50 times), an arbitrarily selected range was photographed in the vertical direction from the top surface of the embossed surface of the release sheet used in each example (exfoliation-treated surface having an embossed pattern). The image was acquired.
Note that, more specifically, the photographing was performed by focusing on the side (non-convex portion) corresponding to the adhesion surface visually from the vertical direction.
In the acquired image, a region T surrounded by a predetermined rectangle is arbitrarily selected as one region, and this is designated as “image of region T”. Here, in the selection of the region T, considering the ease of recognition of the embossed pattern and regularity, the release sheet (1) is 4 mm long x 5 mm wide, the release sheet (2) is 8 mm long x 10 mm wide, For the release sheet (3), 2 mm long × 2.5 mm wide were selected.
The photographing conditions of the digital microscope are as follows.
（測定機器）
　株式会社キーエンス製，製品名「デジタルマイクロスコープＶＨＸ－５０００」，高解像度ズームレンズＶＨＸ－ＺＳＴ１００倍
（測定条件）
撮影方式：ＨＤＲ撮影　　　 
エッジ強調：ＯＦＦ (measuring equipment)
KEYENCE CO., LTD., Product name “Digital Microscope VHX-5000”, High Resolution Zoom Lens VHX-ZST 100x (Measurement Conditions)
Shooting method: HDR shooting
Edge enhancement: OFF
　次に、取得した「領域Ｔの画像」を基に、上記と同じデジタル顕微鏡を用いて自動面積計測を行ない、領域Ｔに存在する各凸部の面積を得た。
　自動面積計測では、まず、デジタル顕微鏡を用いた画像処理により、領域Ｔに存在する凸部の境界の画定および二値化を行い、二値化画像を得た。なお、デジタル顕微鏡の画像処理では凸部の境界が画定できない場合は、上記「領域Ｔの画像」を照合しながら手入力にて凸部の境界を画定し、二値化画像を得た。次に、得られた二値化画像の数値（面積）の計測を行ない、全ての凸部の合計面積を測定した。
　その後、凸部面積率を下記式に基づき算出した。測定結果を表１に示す。
　凸部面積率＝［領域Ｔにおける凸部面積／領域Ｔの総面積］×１００
　また、実施例１～３の剥離シートのエンボス面について得られた二値化画像をそれぞれ図５（ｂ）、図６（ｂ）、および図７（ｂ）に示す。 Next, based on the acquired “image of the region T”, automatic area measurement was performed using the same digital microscope as described above, and the area of each convex portion existing in the region T was obtained.
In the automatic area measurement, first, the boundary of the convex portion existing in the region T was defined and binarized by image processing using a digital microscope, and a binarized image was obtained. When the boundary of the convex portion could not be demarcated by the image processing of the digital microscope, the boundary of the convex portion was demarcated by manual input while collating the “image of the region T” to obtain a binarized image. Next, the numerical value (area) of the obtained binarized image was measured, and the total area of all the convex portions was measured.
Then, the convex part area ratio was computed based on the following formula. The measurement results are shown in Table 1.
Convex part area ratio = [convex part area in region T / total area of region T] × 100
The binarized images obtained for the embossed surfaces of the release sheets of Examples 1 to 3 are shown in FIGS. 5B, 6B, and 7B, respectively.
＜粘着面の凹部面積率の測定＞
　各実施例で得られた粘着シートの粘着面を、ガラス板（コーニング株式会社製，製品名「イーグルＸＧ」）に貼り合せ、接着面をガラス板越しにデジタル顕微鏡（倍率２０～５０倍）を用いて、粘着面上の任意に選択した範囲を上面から垂直方向に撮影し、画像を取得した。得られた画像を図８（ａ）、図９（ａ）、および図１０（ａ）に示す。
　なお、当該撮影に際し、より具体的には、垂直方向から目視にて非凹部だと判断した部位の上方から順に焦点を移動し、初めに焦点があった部分を非凹部として撮影した。
　そして、取得した連結画像において、縦６ｍｍ×横８ｍｍの長方形で囲まれた領域Ｄを１領域任意に選択し、これを「領域Ｄの画像」とした。
　なお、デジタル顕微鏡の撮影条件は以下のとおりである。 <Measurement of concave area ratio of adhesive surface>
The pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet obtained in each example was bonded to a glass plate (Corning Co., Ltd., product name “Eagle XG”), and the adhesive surface was passed through the glass plate with a digital microscope (magnification 20 to 50 times). Using, an arbitrarily selected range on the adhesive surface was photographed vertically from the upper surface, and an image was acquired. The obtained images are shown in FIGS. 8 (a), 9 (a), and 10 (a).
In this case, more specifically, the focal point was sequentially moved from above the portion that was visually determined to be a non-recessed portion from the vertical direction, and the first focused portion was photographed as a non-recessed portion.
Then, in the obtained connected image, a region D surrounded by a rectangle 6 mm long × 8 mm wide is arbitrarily selected as one region, and this is defined as an “image of region D”.
The photographing conditions of the digital microscope are as follows.
（測定機器）
　株式会社キーエンス製，製品名「デジタルマイクロスコープＶＨＸ－５０００」，高解像度ズームレンズＶＨＸ－ＺＳＴ１００倍
（測定条件）
　・落射照明：ＯＮ
　・ステージ透過照明：ＯＦＦ
　・照明きりかえ：同軸落射
　・エッジ強調：ＯＦＦ (measuring equipment)
KEYENCE CO., LTD., Product name “Digital Microscope VHX-5000”, High Resolution Zoom Lens VHX-ZST 100x (Measurement Conditions)
-Epi-illumination: ON
-Stage transmitted illumination: OFF
・ Lighting change: Coaxial incident light ・ Edge enhancement: OFF
　次に、取得した「領域Ｄの画像」を基に、上記と同じデジタル顕微鏡を用いて自動面積計測を行ない、領域Ｄに存在する各凹部の面積を得た。
　自動面積計測では、まず、デジタル顕微鏡を用いた画像処理により、領域Ｄに存在する凹部の境界の画定および二値化を行い、二値化画像を得た。なお、デジタル顕微鏡の画像処理では凹部の境界が画定できない場合は、上記「領域Ｄの画像」を照合しながら手入力にて凹部の境界を画定し、二値化画像を得た。次に、得られた二値化画像の数値（面積）の計測を行ない、全ての凹部の合計面積を測定した。
　その後、凹部面積率を下記式に基づき算出した。測定結果を表１に示す。
　凹部面積率＝［領域Ｄにおける凹部面積／領域Ｄの総面積］×１００
　また、実施例１～３の粘着シートの粘着面について得られた二値化画像をそれぞれ図８（ｂ）、図９（ｂ）、および図１０（ｂ）に示す。 Next, based on the acquired “image of region D”, automatic area measurement was performed using the same digital microscope as described above, and the area of each concave portion existing in region D was obtained.
In the automatic area measurement, first, the boundary of the concave portion existing in the region D was defined and binarized by image processing using a digital microscope, and a binarized image was obtained. In addition, when the boundary of the concave portion could not be defined by the image processing of the digital microscope, the boundary of the concave portion was defined manually while collating the “image of region D”, and a binarized image was obtained. Next, the numerical value (area) of the obtained binarized image was measured, and the total area of all the concave portions was measured.
Thereafter, the concave area ratio was calculated based on the following formula. The measurement results are shown in Table 1.
Recess area ratio = [recess area in area D / total area of area D] × 100
Also, the binarized images obtained for the adhesive surfaces of the adhesive sheets of Examples 1 to 3 are shown in FIG. 8 (b), FIG. 9 (b), and FIG. 10 (b), respectively.
＜粘着力（ＵＶ照射前）の測定＞
　各実施例で得られた粘着シートを縦２５ｍｍ×横３００ｍｍの大きさに切断した後、２３℃、５０％ＲＨ（相対湿度）の環境下で、ガラス板（日本板硝子株式会社製，ソーダライムガラス，縦１５０ｍｍ×横７０ｍｍ×厚さ２ｍｍ）に貼付し、同じ環境下で２４時間静置した。静置後、ＪＩＳ　Ｚ０２３７：２０００に基づき、１８０°引き剥がし法により、引っ張り速度３００ｍｍ／分にて、各粘着シートの粘着力を測定した。測定結果を表１に示す。 <Measurement of adhesive strength (before UV irradiation)>
After the pressure-sensitive adhesive sheet obtained in each Example was cut into a size of 25 mm in length and 300 mm in width, a glass plate (manufactured by Nippon Sheet Glass Co., Ltd., soda lime glass) in an environment of 23 ° C. and 50% RH (relative humidity) , Length 150 mm × width 70 mm × thickness 2 mm) and allowed to stand for 24 hours in the same environment. After standing, the adhesive force of each adhesive sheet was measured at a pulling speed of 300 mm / min by a 180 ° peeling method based on JIS Z0237: 2000. The measurement results are shown in Table 1.
＜粘着力（ＵＶ照射後）の測定＞
　各実施例で得られた粘着シートを縦２５ｍｍ×横３００ｍｍの大きさに切断した後、２３℃、５０％ＲＨ（相対湿度）の環境下で、ガラス板（日本板硝子株式会社製，ソーダライムガラス，縦１５０ｍｍ×横７０ｍｍ×厚さ２ｍｍ）に貼付し、同じ環境下で２４時間静置した。その後、石英ガラス製のチャンバーの中に静置し、照射紫外線照射装置（ヘレウス社製、製品名「ライトハンマー　１０　ＭＡＲＫ　ＩＩ」、無電極ランプ）を用いて、石英ガラス上から２ｃｍの照射距離にて紫外線照射した後に、チャンバーから粘着シートとガラス板を取り出して、ＪＩＳ　Ｚ０２３７：２０００に基づき、１８０°引き剥がし法により、引っ張り速度３００ｍｍ／分にて、各粘着シートの粘着力を測定した。測定結果を表１に示す。
　紫外線照射条件は、波長２００～３８０ｎｍの範囲において、照度７００ｍＷ／ｃｍ２、光量７００ｍＪ／ｃｍ２とし、当該照度及び光量は照度・光量計（ＥＩＴ社製、製品名「ＵＶ　Ｐｏｗｅｒ　Ｐｕｃｋ　ＩＩ」）を用いて照度および光量を測定した。 <Measurement of adhesive strength (after UV irradiation)>
After the pressure-sensitive adhesive sheet obtained in each Example was cut into a size of 25 mm in length and 300 mm in width, a glass plate (manufactured by Nippon Sheet Glass Co., Ltd., soda lime glass) in an environment of 23 ° C. and 50% RH (relative humidity) , Length 150 mm × width 70 mm × thickness 2 mm) and allowed to stand for 24 hours in the same environment. Then, it is left still in a quartz glass chamber, and an irradiation distance of 2 cm from the quartz glass is used using an irradiation ultraviolet irradiation device (manufactured by Heraeus, product name “Light Hammer 10 MARK II”, electrodeless lamp). After the ultraviolet irradiation, the pressure-sensitive adhesive sheet and the glass plate were taken out from the chamber, and the pressure-sensitive adhesive strength of each pressure-sensitive adhesive sheet was measured at a pulling speed of 300 mm / min by a 180 ° peeling method based on JIS Z0237: 2000. The measurement results are shown in Table 1.
The ultraviolet irradiation conditions are an illuminance of 700 mW / cm 2 and a light amount of 700 mJ / cm 2 in a wavelength range of 200 to 380 nm. The illuminance and light amount are determined by an illuminance / light meter (product name “UV Power Pack II” manufactured by EIT). Used to measure illuminance and light intensity.
＜粘着力（ＵＶ照射ならびに減圧後）の測定＞
　各実施例で得られた粘着シートを縦２５ｍｍ×横３００ｍｍの大きさに切断した後、２３℃、５０％ＲＨ（相対湿度）の環境下で、ガラス板（日本板硝子株式会社製，ソーダライムガラス，縦１５０ｍｍ×横７０ｍｍ×厚さ２ｍｍ）に貼付し、同じ環境下で２４時間静置した。静置後、石英ガラス製のチャンバーの中に静置し、照射紫外線照射装置（ヘレウス社製、製品名「ライトハンマー　１０　ＭＡＲＫ　ＩＩ」、無電極ランプ）を用いて、石英ガラス上から２ｃｍの照射距離にて紫外線照射した後に、チャンバーとホースで接続した減圧器を用いて、チャンバー内の雰囲気圧力が２ｋＰａになるまで減圧して１０秒間保持した後、減圧状態を開放して、チャンバーから粘着シートとガラス板を取り出して、ＪＩＳ　Ｚ０２３７：２０００に基づき、１８０°引き剥がし法により、引っ張り速度３００ｍｍ／分にて、各粘着シートの粘着力を測定した。測定結果を表１に示す。
　紫外線照射条件は、＜粘着力（ＵＶ照射後）の測定＞と同様の条件とした。 <Measurement of adhesive strength (after UV irradiation and reduced pressure)>
After the pressure-sensitive adhesive sheet obtained in each Example was cut into a size of 25 mm in length and 300 mm in width, a glass plate (manufactured by Nippon Sheet Glass Co., Ltd., soda lime glass) in an environment of 23 ° C. and 50% RH (relative humidity) , Length 150 mm × width 70 mm × thickness 2 mm) and allowed to stand for 24 hours in the same environment. After standing, leave in a quartz glass chamber and irradiate 2 cm from the top of the quartz glass using an irradiation ultraviolet irradiation device (product name “Light Hammer 10 MARK II”, electrodeless lamp) manufactured by Heraeus. After irradiating with ultraviolet rays at a distance, using a decompressor connected to the chamber and a hose, the pressure inside the chamber is reduced to 2 kPa and held for 10 seconds, then the reduced pressure state is released, and the adhesive sheet is removed from the chamber. And the glass plate was taken out, and the adhesive force of each adhesive sheet was measured at a pulling speed of 300 mm / min by a 180 ° peeling method based on JIS Z0237: 2000. The measurement results are shown in Table 1.
The ultraviolet irradiation conditions were the same as those in <Measurement of adhesive strength (after UV irradiation)>.
＜粘着力減少率＞
　下記式によって粘着力減少率を算出した。結果を表１に示す。
　粘着力減少率（％）＝（ＵＶ照射後粘着力－減圧後粘着力）／（ＵＶ照射後粘着力）×１００ <Adhesion reduction rate>
The adhesive strength reduction rate was calculated by the following formula. The results are shown in Table 1.
Adhesive strength reduction rate (%) = (Adhesive strength after UV irradiation−Adhesive strength after reduced pressure) / (Adhesive strength after UV irradiation) × 100
＜応力緩和率＞
　各実施例において、エンボスフィルムを重剥離シート（リンテック株式会社製，製品名「ＳＰ－ＰＥＴ３８２０５０」、厚さ３８μｍ、シリコーン系剥離剤が塗布されたポリエチレンテレフタレートフィルム）に変更し、基材を軽剥離シート（リンテック株式会社製，製品名「ＳＰ－ＰＥＴ３８１０３１」、厚さ３８μｍ、シリコーン系剥離剤が塗布されたポリエチレンテレフタレートフィルム）に変更し、乾燥後の粘着剤層の厚さが５０μｍとなるように塗布したこと以外は実施例に記載の通りの手順で、２枚の剥離シートに挟持された基材レスの両面粘着シートを作成した。
　基材レスの両面粘着シートを２３℃、５０％ＲＨの雰囲気下で２週間放置し、照射紫外線照射装置（ヘレウス社製、製品名「ライトハンマー　１０　ＭＡＲＫ　ＩＩ」、無電極ランプ）を用いて紫外線を照射した。
　紫外線照射条件は、波長２００～３８０ｎｍの範囲において、照度７００ｍＷ／ｃｍ２、光量７００ｍＪ／ｃｍ２とし、当該照度及び光量は照度・光量計（ＥＩＴ社製、製品名「ＵＶ　Ｐｏｗｅｒ　Ｐｕｃｋ　ＩＩ」）を用いて照度および光量を測定した。 <Stress relaxation rate>
In each example, the embossed film was changed to a heavy release sheet (manufactured by Lintec Co., Ltd., product name “SP-PET 382050”, thickness 38 μm, polyethylene terephthalate film coated with a silicone release agent), and the substrate was lightly released. Change to a sheet (manufactured by Lintec Corporation, product name “SP-PET 381031”, thickness 38 μm, polyethylene terephthalate film coated with silicone release agent), so that the thickness of the adhesive layer after drying is 50 μm A substrate-less double-sided pressure-sensitive adhesive sheet sandwiched between two release sheets was prepared in the same manner as described in the Examples except that it was applied.
The substrate-less double-sided pressure-sensitive adhesive sheet is allowed to stand for 2 weeks in an atmosphere of 23 ° C. and 50% RH, and is irradiated with ultraviolet rays using an irradiation ultraviolet irradiation device (product name “Light Hammer 10 MARK II”, electrodeless lamp) manufactured by Heraeus. Was irradiated.
The ultraviolet irradiation conditions are an illuminance of 700 mW / cm 2 and a light amount of 700 mJ / cm 2 in a wavelength range of 200 to 380 nm. The illuminance and light amount are determined by an illuminance / light meter (product name “UV Power Pack II” manufactured by EIT). Used to measure illuminance and light intensity.
　その後、上記粘着剤層を複数層積層した粘着シートから１５ｍｍ幅×１２０ｍｍ長のサンプルを切り出し、積層体の最表層に積層された剥離シートを剥し、サンプル測定範囲が１５ｍｍ幅×１００ｍｍ長になるようにサンプルを万能引張試験機（株式会社島津製作所製，オートグラフＡＧ－１０ｋＮＩＳ）にセットした。そして、２３℃、５０％ＲＨ（相対湿度）の環境下にて、引張速度２００ｍｍ／分でサンプルを伸長させ、１０％伸長時の応力Ａ（Ｐａ）と、伸長停止から３００秒後の応力Ｂ（Ｐａ）とを測定した。測定はＭＤ方向、つまり粘着剤の塗布方向と平行である方向のみを測定した。測定された応力Ａおよび応力Ｂから、以下の式を用いて、応力緩和率（％）を算出した。測定結果を表１に示す。
　応力緩和率（％）＝{（Ａ－Ｂ）／Ａ}×１００（％） Thereafter, a 15 mm wide × 120 mm long sample is cut out from the pressure sensitive adhesive sheet in which a plurality of the pressure sensitive adhesive layers are laminated, and the release sheet laminated on the outermost layer of the laminate is peeled off so that the sample measurement range becomes 15 mm wide × 100 mm long. The sample was set in a universal tensile testing machine (manufactured by Shimadzu Corporation, Autograph AG-10kNIS). Then, in an environment of 23 ° C. and 50% RH (relative humidity), the sample was stretched at a pulling rate of 200 mm / min, a stress A (Pa) at the time of 10% elongation, and a stress B after 300 seconds from the elongation stop. (Pa) was measured. The measurement was performed only in the MD direction, that is, the direction parallel to the adhesive application direction. From the measured stress A and stress B, the stress relaxation rate (%) was calculated using the following equation. The measurement results are shown in Table 1.
Stress relaxation rate (%) = {(AB) / A} × 100 (%)
＜破断伸度＞
　応力緩和率の測定に使用したサンプルと同じ形態、大きさのサンプルを、前述の応力緩和率の測定と同じ様にサンプル測定範囲が１５ｍｍ幅×１００ｍｍ長となるように万能引張試験機（株式会社島津製作所製，オートグラフＡＧ－１０ｋＮＩＳ）にセットした。そして、２３℃、５０％ＲＨ（相対湿度）の環境下にて、引張速度２００ｍｍ／分でサンプルを伸長させ破断した時のサンプルの長さＣ（ｍｍ）を測定した。測定はＭＤ方向、つまり粘着剤の塗布方向と平行である方向のみを測定した。破断した時のサンプルの長さＣ（ｍｍ）から、以下の式を用いて破断伸度（％）を算出した。測定結果を表１に示す。
　破断伸度（％）＝｛Ｃ／測定前のサンプル長さ｝×１００（％） <Elongation at break>
Universal tensile testing machine (Inc.) with the same form and size as the sample used for the measurement of the stress relaxation rate, so that the sample measurement range is 15 mm wide x 100 mm long, similar to the measurement of the stress relaxation rate described above. Shimadzu Corporation, Autograph AG-10k NIS). Then, in an environment of 23 ° C. and 50% RH (relative humidity), the length C (mm) of the sample when the sample was stretched and broken at a tensile speed of 200 mm / min was measured. The measurement was performed only in the MD direction, that is, the direction parallel to the adhesive application direction. The elongation at break (%) was calculated from the length C (mm) of the sample at the time of fracture using the following formula. The measurement results are shown in Table 1.
Elongation at break (%) = {C / sample length before measurement} × 100 (%)
＜ゲル分率＞
　実施例で得られた粘着シートを８０ｍｍ×８０ｍｍの大きさに裁断して、剥離シートを除去した粘着剤層をポリエステル製メッシュ（メッシュ数：２００メッシュ／インチ）に包み、粘着剤のみの質量を精密天秤にて秤量した。このときの質量をＭ１とする。
　次に、酢酸エチル溶剤に上記粘着剤のサンプルを室温（２３℃）で２４時間浸漬させた。その後粘着剤を取り出し、温度２３℃、５０％ＲＨの環境下で、２４時間風乾させ、さらに８０℃のオーブン中にて１２時間乾燥させた。乾燥後の粘着剤のみの質量を、精密天秤にて秤量した。このときの質量をＭ２とする。ゲル分率（％)は、（Ｍ２／Ｍ１）×１００で表される。測定結果を表１に示す。 <Gel fraction>
The pressure-sensitive adhesive sheet obtained in the examples was cut into a size of 80 mm × 80 mm, and the pressure-sensitive adhesive layer from which the release sheet was removed was wrapped in a polyester mesh (number of meshes: 200 mesh / inch). Weighed with a precision balance. The mass at this time is M1.
Next, the pressure-sensitive adhesive sample was immersed in an ethyl acetate solvent at room temperature (23 ° C.) for 24 hours. Thereafter, the pressure-sensitive adhesive was taken out and air-dried for 24 hours in an environment of a temperature of 23 ° C. and 50% RH, and further dried in an oven at 80 ° C. for 12 hours. The mass of only the pressure-sensitive adhesive after drying was weighed with a precision balance. The mass at this time is M2. The gel fraction (%) is represented by (M2 / M1) × 100. The measurement results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１に示される通り、実施例１～３のいずれにおいても、減圧処理を行うことにより粘着力が低下し、粘着シートと被着体との剥離が容易になることが確認された。 As shown in Table 1, in any of Examples 1 to 3, it was confirmed that the pressure-sensitive adhesive treatment reduced the adhesive strength and facilitated peeling between the adhesive sheet and the adherend.
１…粘着シート
　２…粘着剤層
　３…凹部
　４…基材
Ｐ…粘着面
Ｃ…空間
Ｗ…ワーク
Ｗ’…加工物
Ｅ…端部
１０…圧力制御装置 DESCRIPTION OF SYMBOLS 1 ... Adhesive sheet 2 ... Adhesive layer 3 ... Concave 4 ... Base material P ... Adhesive surface C ... Space W ... Work W '... Workpiece E ... End part 10 ... Pressure control apparatus

Claims (11)

  1. 　少なくとも粘着剤層を備える粘着シートと、前記粘着剤層の粘着面に貼着された被着体とを剥離する粘着シートの剥離方法であって、
    　前記粘着剤層は、前記粘着面に凹部を有し、
    　前記被着体は、前記粘着剤層の前記凹部により独立した空間が生じるように前記粘着シートに貼着されており、
    　少なくとも前記被着体が貼着された前記粘着シートに対し、前記空間中の気体を膨張させる減圧処理を行うことにより、前記粘着剤層の粘着力を低下させ、前記粘着シートと前記被着体とを剥離する
    ことを特徴とする粘着シートの剥離方法。     A pressure-sensitive adhesive sheet peeling method for peeling a pressure-sensitive adhesive sheet having at least a pressure-sensitive adhesive layer and an adherend adhered to the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer,
    The pressure-sensitive adhesive layer has a concave portion on the pressure-sensitive adhesive surface,
    The adherend is adhered to the pressure-sensitive adhesive sheet so that an independent space is created by the concave portion of the pressure-sensitive adhesive layer,
    At least the pressure-sensitive adhesive sheet to which the adherend is adhered is subjected to a decompression treatment for expanding the gas in the space, thereby reducing the adhesive strength of the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive sheet and the adherend. A method for peeling the pressure-sensitive adhesive sheet, wherein
  2. 　前記減圧処理は、前記粘着シートを前記被着体に貼着した環境の雰囲気圧力よりも低くすることを特徴とする請求項１に記載の粘着シートの剥離方法。 2. The pressure-sensitive adhesive sheet peeling method according to claim 1, wherein the pressure reduction treatment is performed at a pressure lower than an atmospheric pressure of an environment in which the pressure-sensitive adhesive sheet is adhered to the adherend.
  3. 　前記粘着剤層を形成する粘着剤組成物は、活性エネルギー線硬化性および熱硬化性を有さないことを特徴とする請求項１または２に記載の粘着シートの剥離方法。 The pressure-sensitive adhesive sheet peeling method according to claim 1 or 2, wherein the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer does not have active energy ray curability and thermosetting.
  4. 　前記粘着剤組成物は（メタ）アクリル酸エステル重合体を含有することを特徴とする請求項３に記載の粘着シートの剥離方法。 The pressure-sensitive adhesive sheet peeling method according to claim 3, wherein the pressure-sensitive adhesive composition contains a (meth) acrylic acid ester polymer.
  5. 　前記粘着剤層を形成する粘着剤組成物は、活性エネルギー線硬化性または熱硬化性を有することを特徴とする請求項１または２に記載の粘着シートの剥離方法。 The pressure-sensitive adhesive sheet peeling method according to claim 1 or 2, wherein the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer has active energy ray curability or thermosetting.
  6. 　前記活性エネルギー線硬化性粘着剤組成物は、側鎖に活性エネルギー線硬化性基を有する（メタ）アクリル酸エステル重合体を含有することを特徴とする請求項５に記載の粘着シートの剥離方法。 The said active energy ray-curable adhesive composition contains the (meth) acrylic acid ester polymer which has an active energy ray-curable group in a side chain, The peeling method of the adhesive sheet of Claim 5 characterized by the above-mentioned. .
  7. 　前記粘着剤層に対しエネルギー線を照射して前記粘着剤層を硬化させたのち、前記減圧処理を行うことを特徴とする請求項５または６に記載の粘着シートの剥離方法。 The pressure-sensitive adhesive sheet peeling method according to claim 5 or 6, wherein the pressure-reducing treatment is carried out after the pressure-sensitive adhesive layer is cured by irradiating the pressure-sensitive adhesive layer with an energy ray.
  8. 　前記減圧処理を行ったのち、前記粘着剤層に対しエネルギー線を照射して前記粘着剤層を硬化させることを特徴とする請求項５または６に記載の粘着シートの剥離方法。 The pressure-sensitive adhesive sheet peeling method according to claim 5 or 6, wherein the pressure-sensitive adhesive layer is cured by irradiating the pressure-sensitive adhesive layer with an energy ray after the pressure reduction treatment.
  9. 　前記粘着シートは、前記被着体の仮固定に用いられることを特徴とする請求項１～８のいずれか一項に記載の粘着シートの剥離方法。 The pressure-sensitive adhesive sheet peeling method according to any one of claims 1 to 8, wherein the pressure-sensitive adhesive sheet is used for temporarily fixing the adherend.
  10. 　前記被着体は電子部材または光学部材であることを特徴とする請求項９に記載の粘着シートの剥離方法。 The pressure-sensitive adhesive sheet peeling method according to claim 9, wherein the adherend is an electronic member or an optical member.
  11. 　ワークを加工して得られる加工物の製造方法であって、
    　ワークと、少なくとも粘着剤層を備え、前記粘着剤層の粘着面に凹部を有する粘着シートとを、前記粘着面の前記凹部と前記ワークとで独立した空間が生じるように貼着する貼着工程と、
    　前記粘着シートに貼着された前記ワークを加工して加工物とする加工工程と、
    　少なくとも前記加工物が貼着された前記粘着シートを減圧環境に置いて前記空間中の気体を膨張させる減圧処理を行うことにより、前記粘着剤層の粘着力を低下させ、前記加工物と前記粘着シートとを剥離する剥離工程と
    を備えることを特徴とする加工物の製造方法。     A method of manufacturing a workpiece obtained by processing a workpiece,
    A sticking step of sticking a work and at least a pressure-sensitive adhesive layer, and sticking a pressure-sensitive adhesive sheet having a concave portion on the pressure-sensitive adhesive layer so that an independent space is formed between the concave portion of the pressure-sensitive adhesive surface and the work. When,
    A processing step of processing the workpiece adhered to the pressure-sensitive adhesive sheet into a processed product,
    At least the pressure-sensitive adhesive sheet to which the workpiece is adhered is placed in a reduced pressure environment to perform a pressure reduction treatment for expanding the gas in the space, thereby reducing the adhesive strength of the pressure-sensitive adhesive layer, and the workpiece and the pressure-sensitive adhesive. A method for producing a workpiece, comprising: a peeling step for peeling the sheet.
PCT/JP2018/012837 2017-03-31 2018-03-28 Adhesive sheet WO2018181510A1 (en)

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JP2009035660A (en) * 2007-08-03 2009-02-19 Nippon Zeon Co Ltd Method for peeling foamed self-adhesive sheet
JP2010129701A (en) * 2008-11-26 2010-06-10 Nitto Denko Corp Dicing die-bonding film and method for producing semiconductor device
JP2012136678A (en) * 2010-12-28 2012-07-19 Nitto Denko Corp Radiation-curable pressure-sensitive adhesive composition, and pressure-sensitive adhesive sheet
JP2012193317A (en) * 2011-03-17 2012-10-11 Nitto Denko Corp Pressure-sensitive adhesive tape for temporary fixing of electronic part

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JP2002121505A (en) * 2000-10-18 2002-04-26 Nitto Denko Corp Energy ray curing heat release adhesive sheet, and manufacturing method of cut piece therewith
JP2009035660A (en) * 2007-08-03 2009-02-19 Nippon Zeon Co Ltd Method for peeling foamed self-adhesive sheet
JP2010129701A (en) * 2008-11-26 2010-06-10 Nitto Denko Corp Dicing die-bonding film and method for producing semiconductor device
JP2012136678A (en) * 2010-12-28 2012-07-19 Nitto Denko Corp Radiation-curable pressure-sensitive adhesive composition, and pressure-sensitive adhesive sheet
JP2012193317A (en) * 2011-03-17 2012-10-11 Nitto Denko Corp Pressure-sensitive adhesive tape for temporary fixing of electronic part

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