Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F8/00—Chemical modification by after-treatment
  • C08F8/30—Introducing nitrogen atoms or nitrogen-containing groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/04—Acids; Metal salts or ammonium salts thereof
  • C08F220/06—Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/12—Esters of monohydric alcohols or phenols
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/20—Esters of polyhydric alcohols or phenols, e.g. 2-hydroxyethyl (meth)acrylate or glycerol mono-(meth)acrylate
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/62—Polymers of compounds having carbon-to-carbon double bonds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/62—Polymers of compounds having carbon-to-carbon double bonds
  • C08G18/6216—Polymers of alpha-beta ethylenically unsaturated carboxylic acids or of derivatives thereof
  • C08G18/622—Polymers of esters of alpha-beta ethylenically unsaturated carboxylic acids
  • C08G18/6225—Polymers of esters of acrylic or methacrylic acid
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
  • C08G59/42—Polycarboxylic acids; Anhydrides, halides or low molecular weight esters thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
  • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
  • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
  • C08G59/62—Alcohols or phenols
• • 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
  • C09J163/00—Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins
• • 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
  • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P95/00—Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F2438/00—Living radical polymerisation
  • C08F2438/03—Use of a di- or tri-thiocarbonylthio compound, e.g. di- or tri-thioester, di- or tri-thiocarbamate, or a xanthate as chain transfer agent, e.g . Reversible Addition Fragmentation chain Transfer [RAFT] or Macromolecular Design via Interchange of Xanthates [MADIX]

Definitions

• the content of the present disclosure relates to a method for producing a (meth)acrylic resin used in a pressure-sensitive adhesive composition and a method for producing a pressure-sensitive adhesive composition.
• Adhesive compositions used in the adhesive layer of removable adhesive sheets include those containing resins in which UV (ultraviolet rays) curable ethylenically unsaturated groups are introduced into the side chains of (meth)acrylic resins.
• Such an adhesive composition undergoes a crosslinking reaction and is cured by UV irradiation, resulting in a decrease in adhesive strength.
• Patent Document 1 Japanese Unexamined Patent Application Publication No. 2018-138682 describes a living radical polymerization polymer having a molecular weight distribution (Mw/Mn) of 1.05 to 2.5, particularly a living radical polymerization polymer using an organic tellurium polymerization initiator.
• An adhesive tape containing a (meth)acrylic polymer in which a polymerizable group that can be cured by ultraviolet rays is introduced into the side chain of the polymer obtained by the method is described.
• a dicing/die bond integrated film is used, which is a film in which a dicing tape, which is a removable adhesive sheet, and a die bond (adhesive layer) are integrated.
• This film is used, for example, by attaching an adhesive layer to the back surface of a semiconductor wafer and attaching an adhesive layer derived from a dicing tape to a dicing ring. Thereafter, the semiconductor wafer is diced using a dicing blade to obtain individualized semiconductor chips.
• the adhesive layer derived from the dicing tape is required to have high adhesion to the adhesive layer and the dicing ring in the dicing process, but in the semiconductor chip pickup process, adhesive residue (adhesive residue) is left on each semiconductor chip. It is required to be able to easily pick up semiconductor chips with adhesive pieces. If the adhesion of the adhesive layer to the adhesive layer is insufficient, the high-speed rotation of the dicing blade will cause peeling between the adhesive layers and break the adhesive layer, resulting in broken edges of the adhesive layer. A scattering phenomenon (DAF (Die Attach Film) flying) occurs. If the adhesive force of the adhesive layer to the dicing ring is insufficient, a phenomenon in which the dicing ring peels off from the adhesive layer (ring peeling) occurs due to the flow of cutting water.
• DAF Die Attach Film
• stealth dicing has been attracting attention as a dicing method that does not use a dicing blade.
• a laser beam is focused inside the wafer to form a starting point (modified layer) for dividing the wafer, a removable adhesive sheet is attached to the back of the wafer, and this sheet is cooled and expanded. , obtain singulated semiconductor chips.
• the wafer and adhesive layer are separated into pieces by cooling expansion.
• the outer periphery of the adhesive layer may break due to the impact and stress during expansion, causing the phenomenon of scattering of pieces (DAF flying) or the adhesion. Peeling between the edge of the chip with the adhesive and the adhesive layer (chip edge peeling) may occur, causing problems in subsequent steps.
• the adhesive layer used in the dicing/die-bonding integrated film has high adhesion to the adhesive layer and can be easily peeled off from the adhesive layer without leaving any adhesive residue after UV irradiation. Characteristics that are not required for releasable pressure-sensitive adhesive sheets are required. Therefore, it is difficult to apply the acrylic pressure-sensitive adhesive conventionally used in removable pressure-sensitive adhesive sheets to a dicing/die-bonding integrated film as is.
• the present disclosure has sufficient adhesion to the adhesive layer, and when the adhesive sheet is peeled off from the adhesive layer after UV irradiation, excellent peelability is obtained and no adhesive remains.
• a manufacturing method capable of obtaining a (meth)acrylic resin or a pressure-sensitive adhesive composition containing a (meth)acrylic resin that can provide a pressure-sensitive adhesive layer that is difficult to peel.
• the present inventors used a copolymer obtained by reversible addition fragmentation chain transfer (RAFT) polymerization of a hydroxy group-containing (meth)acrylate and an alkyl (meth)acrylate with an isocyanato group-containing ethylenically unsaturated compound. It has been found that a modified polymer can be suitably used in the adhesive layer of a dicing/die-bonding integrated film.
• RAFT reversible addition fragmentation chain transfer
• a copolymer is obtained by polymerizing a raw material monomer group (M) containing a hydroxy group-containing (meth)acrylate (m-1) and an alkyl (meth)acrylate (m-2) by reversible addition-fragmentation chain transfer (RAFT).
• An isocyanato group-containing ethylenically unsaturated compound (a) is added to a part of the side chain hydroxyl groups of the copolymer (A-0) to produce a (meth)acrylic resin (A) having an ethylenically unsaturated group.
• Step (ii) of obtaining A method for producing a (meth)acrylic resin containing [2] The method for producing a (meth)acrylic resin according to [1], wherein the raw material monomer group (M) further contains a carboxy group-containing monomer (m-3). [3] The (meth)acrylic resin according to [1] or [2], wherein the (meth)acrylic resin (A) having an ethylenically unsaturated group has a molecular weight distribution (Mw/Mn) of 2.4 to 10.0. Production method.
• a (meth)acrylic resin (A) having an ethylenically unsaturated group obtained by the production method according to any one of [1] to [3], a photopolymerization initiator (B), and a crosslinking agent (C) A method for producing an adhesive composition, comprising the step (iii) of mixing. [5] The method for producing an adhesive composition according to [4], wherein the crosslinking agent (C) is at least one selected from the group consisting of polyisocyanates and polyepoxy compounds. [6] [4] or [5] A method for producing an adhesive layer, comprising a step of forming a crosslinked structure in the adhesive composition obtained by the production method according to [5].
• a method for producing a pressure-sensitive adhesive sheet comprising applying the pressure-sensitive adhesive composition obtained by the production method according to [4] or [5] to a sheet-like base material to prepare a pressure-sensitive adhesive layer.
• a method for producing a pressure-sensitive adhesive sheet comprising a step of forming a crosslinked structure in the pressure-sensitive adhesive layer obtained by the method according to [7].
• [10] [4] or [5] A method for producing an integrated dicing and die bonding film, the method comprising applying the pressure-sensitive adhesive composition obtained by the production method according to [5] to an adhesive layer.
• the (meth)acrylic resin obtained by the method of the present disclosure in the adhesive layer of the dicing/die-bonding integrated film, it has sufficient adhesion to the adhesive layer and is sticky after UV irradiation.
• the sheet is peeled off from the adhesive layer, it is possible to obtain an adhesive layer that exhibits excellent peelability and is less likely to leave adhesive residue.
• (meth)acrylic means methacrylic or acrylic
• (meth)acrylate means acrylate or methacrylate
• (meth)acryloyloxy means acryloyloxy or methacryloyloxy. do.
• weight average molecular weight and “number average molecular weight” are measured at room temperature (23°C) using gel permeation chromatography (GPC) under the following conditions, and a standard polystyrene calibration curve is used.
• GPC gel permeation chromatography
• glass transition temperature refers to the temperature of a sample taken from -100°C to 200°C at a heating rate of 10°C/min using a differential scanning calorimeter (DSC). Differential scanning calorimetry was performed while changing the temperature, and this is the observed temperature at which endotherm begins due to glass transition. If two or more endothermic onset temperatures are observed, Tg is the simple average value of the two or more endothermic onset temperatures.
• a method for producing a (meth)acrylic resin (A) having an ethylenically unsaturated group includes hydroxyl group-containing (meth)acrylate (m-1), and A copolymer (A-0) is obtained by subjecting a raw material monomer group (M) containing an alkyl (meth)acrylate (m-2) to reversible addition-fragmentation chain transfer (RAFT) polymerization.
• RAFT addition-fragmentation chain transfer
• the raw material monomer group (M) may contain a carboxy group-containing monomer (m-3).
• the copolymer (A-0) is prepared by combining a hydroxy group-containing (meth)acrylate (m-1) and an alkyl (meth)acrylate (m-2) in the presence of a reversible addition-fragmentation chain transfer agent (RAFT agent), It can also be obtained by RAFT polymerizing a raw material monomer group (M) optionally containing a carboxy group-containing monomer (m-3).
• RAFT polymerization refers to radical polymerization performed in the presence of a RAFT agent.
• RAFT polymerization is a type of living radical polymerization.
• Living radical polymerization is generally known as a polymerization method capable of obtaining a polymer with a small molecular weight distribution, and specific examples thereof include atom transfer radical polymerization, organic tellurium-mediated radical polymerization, RAFT polymerization, and the like.
• RAFT polymerization does not use halogens or heavy metals, so it has a low environmental impact and is suitable for semiconductor applications.
• the copolymer (A-0) obtained by RAFT polymerization has a more appropriate molecular weight distribution than (meth)acrylic copolymers obtained by other living radical polymerizations.
• the adhesive composition produced using the (meth)acrylic resin (A) obtained from the copolymer (A-0) has excellent wettability to the adhesive layer and high adhesion to the adhesive layer. have power. This is because the low molecular weight component of the (meth)acrylic resin (A) contributes to the wettability and fluidity of the adhesive composition. If the molecular weight distribution of the (meth)acrylic copolymer is too narrow, the resulting pressure-sensitive adhesive composition will have low fluidity and wettability with respect to the adhesive layer, and sufficient adhesion will not be obtained.
• a solution polymerization method As the polymerization method, a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a suspension polymerization method, an alternating copolymerization method, etc. can be used. Among these polymerization methods, in consideration of the addition reaction in step (ii), it is preferable to use the solution polymerization method in terms of ease of reaction.
• the hydroxy group-containing (meth)acrylate (m-1) is not particularly limited as long as it has a hydroxy group and a (meth)acryloyloxy group.
• hydroxyalkyl (meth)acrylates such as acrylate; (meth)acrylates having an aromatic ring and a hydroxyl group such as hydroxyphenyl (meth)acrylate and 2-hydroxy-3-phenoxypropyl (meth)acrylate;
• hydroxyalkyl (meth)acrylates are preferred, hydroxyalkyl (meth)acrylates in which the hydroxyalkyl group has 1 to 6 carbon atoms are more preferred, and 2-hydroxyethyl More preferred are (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate.
• the content of the hydroxy group-containing (meth)acrylate (m-1) is preferably 5 to 50 mol%, more preferably 10 to 40 mol%, based on 100 mol% of the raw material monomer group (M). , more preferably 15 to 35 mol%.
• the content of the hydroxy group-containing (meth)acrylate (m-1) is 5 mol% or more, the (meth)acrylic resin (A) has sufficient hydroxy groups and the amount of crosslinking with the crosslinking agent (C) is Therefore, it is possible to obtain an adhesive layer having sufficient cohesive force.
• reaction points for introducing ethylenically unsaturated groups can be secured, and better peelability can be obtained when the pressure-sensitive adhesive sheet is peeled off from the adherend after UV irradiation.
• the content of the hydroxy group-containing (meth)acrylate (m-1) is 50 mol% or less, unintended progress of reaction in the adhesive composition can be suppressed, resulting in good storage stability. It is.
• alkyl (meth)acrylate (m-2) The alkyl (meth)acrylate (m-2) is not particularly limited as long as it does not have a hydroxy group or a carboxy group and has an alkyl group and a (meth)acryloyloxy group.
• the alkyl group in the alkyl (meth)acrylate (m-2) may be substituted.
• the substituent include alkoxy groups such as methoxy and ethoxy groups.
• alkyl (meth)acrylates and alicyclic alkyl (meth)acrylates in which the alkyl group has 1 to 20 carbon atoms are preferred, and methyl (meth)acrylate, Ethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, ) acrylate and dicyclopentanyl (meth)acrylate are more preferred.
• the content of alkyl (meth)acrylate (m-2) is preferably 10 to 94 mol%, more preferably 30 to 85 mol%, and further Preferably it is 50 to 80 mol%.
• the content of alkyl (meth)acrylate (m-2) is 10 mol% or more, excellent adhesiveness can be obtained.
• the content of alkyl (meth)acrylate (m-2) is 94 mol% or less, a sufficient content of hydroxyl groups and ethylenically unsaturated groups in the (meth)acrylic resin (A) can be ensured. Therefore, an adhesive layer having well-balanced physical properties can be obtained from the viewpoint of the cohesive force of the adhesive layer and the peelability of the adhesive sheet after UV irradiation.
• the carboxyl group-containing monomer (m-3) is not particularly limited as long as it does not have a hydroxyl group and has a carboxyl group and an ethylenically unsaturated group.
• unsaturated monobasic acids such as (meth)acrylic acid, crotonic acid, vinylbenzoic acid, ⁇ -haloalkyl, alkoxyl, halogen, nitro, or cyano substituted products of acrylic acid, and unsaturated dibasic acids such as itaconic acid. can be mentioned.
• (meth)acrylic acid is preferred from the viewpoint of ease of production of the adhesive.
• the content of the carboxy group-containing monomer (m-3) is preferably 0.1 to 0.1 to 100 mol% of the raw material monomer group (M).
• the content is 10 mol%, more preferably 0.5 to 8.0 mol%, even more preferably 1.0 to 5.0 mol%.
• the content of the carboxy group-containing monomer (m-3) is 0.1 mol% or more, a sufficient amount of crosslinking can be ensured when the crosslinking agent (C) is a polyepoxy compound. , sufficient cohesive force of the adhesive can be obtained.
• the raw material monomer group (M) may contain monomers (m-4) other than (m-1) to (m-3).
• monomers (m-4) include dienes such as butadiene and dicyclopentadiene, styrenes, unsaturated dicarboxylic acid diesters, and other vinyl compounds.
• styrenes include styrene, ⁇ -, o-, m-, or p-alkyl derivatives of styrene.
• unsaturated dicarboxylic acid diesters include diethyl citraconate, diethyl maleate, diethyl fumarate, diethyl itaconate, and the like.
• vinyl compounds include norbornene (bicyclo[2.2.1]hept-2-ene), 5-methylbicyclo[2.2.1]hept-2-ene, 5-ethylbicyclo[ 2.2.1] hept-2-ene, tetracyclo[4.4.0.1 2,5 . 1 7,10 ] dodec-3-ene, 8-methyltetracyclo[4.4.0.1 2,5 . 1 7,10 ] dodec-3-ene, 8-ethyltetracyclo[4.4.0.1 2,5 .
• RAFT agent Reversible addition-fragmentation chain transfer agent
• any known RAFT agent can be used without particular limitation.
• sulfur-based compounds trithiocarbonate, dithioester, dithiocarbonate, and dithiocarbamate
• formula (1), formula (2), formula (3), or formula (4) are preferred.
• R 1a and R 1b are the same or different and represent a hydrogen atom, a hydrocarbon group, a carboxy group, or a cyano group, and R 1c is substituted with a cyano group, a cyano group, or a carboxy group.
• R2 represents a saturated or unsaturated aliphatic hydrocarbon group that may be substituted with a carboxy group, or a phenyl group that may be substituted; Indicates a hydrocarbon group or an optionally substituted benzyl group.
• R 3a and R 3b are the same or different and represent a hydrogen atom, a hydrocarbon group, or a cyano group, and R 3c is a carboxy group, an acetoxymethyl group, a cyano group, or a carboxy group. represents a hydrocarbon group that may be substituted, and R 4 represents a hydrocarbon group.
• R 5a and R 5b are the same or different and are a hydrogen atom, a hydrocarbon group, a carboxy group which may be substituted with a saturated aliphatic hydrocarbon group having 1 to 3 carbon atoms, or a cyano (R 5c represents a hydrocarbon group which may be substituted with an alkoxy group, and R 6 represents a hydrocarbon group.)
• R 7a and R 7b are the same or different and represent a hydrogen atom or a hydrocarbon group
• R 7c is a cyano group
• R 8 and R 9 are the same or different, It may represent a hydrocarbon group, or R 8 and R 9 may combine to form a pyrazole ring which may be substituted with a saturated aliphatic hydrocarbon group having 1 to 3 carbon atoms or a chlorine atom.
• the hydrocarbon group represented by R 1a and R 1b includes, for example, a straight chain, branched or cyclic, saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms, Among these, straight chain, branched or cyclic, saturated or unsaturated hydrocarbon groups having 1 to 12 carbon atoms are preferred.
• the hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a cyclohexyl group, a dodecyl group, an octadecyl group, etc.
• the saturated or unsaturated aliphatic hydrocarbon group represented by R 1c is, for example, a linear, branched or cyclic saturated or unsaturated aliphatic hydrocarbon group having 1 to 20 carbon atoms. Hydrogen groups are mentioned, and among them, linear, branched or cyclic, saturated or unsaturated aliphatic hydrocarbon groups having 1 to 12 carbon atoms are preferred.
• Examples of the aliphatic hydrocarbon group include carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, cyclohexyl group, dodecyl group, and octadecyl group.
• Examples include 1 to 20 linear, branched, or cyclic saturated aliphatic hydrocarbon groups.
• 1 to 3 hydrogen atoms of the saturated or unsaturated aliphatic hydrocarbon group represented by R 1c may be substituted with a carboxy group or a cyano group, and the carboxy group is a carbon It may be further substituted with a saturated aliphatic hydrocarbon group having 1 to 3 atoms.
• substituents for the optionally substituted phenyl group represented by R 1c include a substituted carbamoyl group, an alkoxycarbonyl group having 2 to 5 carbon atoms which may be substituted with a hydroxy group, and a carbon atom number Examples include 3 to 5 alkenyloxycarbonyl groups.
• the substituent of the substituted carbamoyl group examples include a saturated aliphatic hydrocarbon group having 1 to 3 carbon atoms which may be substituted with a hydroxy group or an acetyloxy group.
• the saturated or unsaturated aliphatic hydrocarbon group represented by R 2 is, for example, a linear, branched or cyclic saturated or unsaturated aliphatic hydrocarbon group having 1 to 20 carbon atoms. Examples include hydrogen groups, and among them, aliphatic hydrocarbon groups having 1 to 12 carbon atoms are preferred.
• Examples of the aliphatic hydrocarbon group include carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, cyclohexyl group, dodecyl group, and octadecyl group.
• Examples include 1 to 20 linear, branched, or cyclic saturated aliphatic hydrocarbon groups.
• 1 to 3 hydrogen atoms of the saturated or unsaturated aliphatic hydrocarbon group represented by R 2 may be substituted with a carboxy group.
• substituents for the optionally substituted benzyl group represented by R 2 include a substituted carbamoyl group, an alkoxycarbonyl group having 2 to 5 carbon atoms which may be substituted with a hydroxy group, and a carbon atom number Examples include 3 to 5 alkenyloxycarbonyl groups.
• substituent of the substituted carbamoyl group include a saturated aliphatic hydrocarbon group having 1 to 3 carbon atoms which may be substituted with a hydroxy group or an acetyloxy group.
• R 1a and R 1b are the same or different and are a hydrogen atom, a hydrocarbon group having 1 to 4 carbon atoms, or a carboxy group
• R 1c is a hydrocarbon group having 1 to 4 carbon atoms, or a phenyl group which may be substituted
• R 2 is a linear, branched or cyclic, saturated or unsaturated aliphatic hydrocarbon group having 1 to 20 carbon atoms, or a benzyl group which may be substituted.
• a compound represented by a certain formula (1) is preferred, in which R 1a and R 1b are a hydrogen atom, a combination of a methyl group or an ethyl group, and a carboxy group, or a hydrogen atom, and R 1c is a methyl group, an ethyl group, or a phenyl group which may be substituted, and a compound represented by formula (1) in which R 2 is a linear saturated aliphatic hydrocarbon group having 1 to 20 carbon atoms, or a benzyl group which may be substituted; More preferred.
• the hydrocarbon group represented by R 3a , R 3b , R 3c and R 4 is, for example, a linear, branched or cyclic, saturated or unsaturated carbonized group having 1 to 20 carbon atoms. Hydrogen groups are mentioned, and among them, straight chain, branched or cyclic, saturated or unsaturated hydrocarbon groups having 1 to 12 carbon atoms are preferred.
• hydrocarbon group examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a cyclohexyl group, a dodecyl group, an octadecyl group, etc. ⁇ 20 linear, branched or cyclic saturated aliphatic hydrocarbon groups; aryl groups with 6 to 12 carbon atoms such as phenyl groups; arylalkyl groups with 7 to 10 carbon atoms such as benzyl groups and phenethyl groups, etc. can be mentioned.
• the hydrocarbon group which may be substituted with a cyano group or a carboxy group represented by R 3c is, for example, a hydrocarbon group in which 1 to 3 of the hydrogen atoms of the above-mentioned hydrocarbon group are cyano groups or carboxy groups. Examples include groups substituted with .
• R 3a and R 3b are the same or different and are linear saturated hydrocarbon groups having 1 to 4 carbon atoms
• R 3c is an aryl group
• R 4 is an aryl group or a benzyl group.
• a compound represented by a certain formula (2) is preferred, in which R 3a and R 3b are the same or different and are a methyl group or an ethyl group, R 3c is a phenyl group, and R 4 is a phenyl group or a benzyl group.
• a compound represented by formula (2) is more preferred.
• the hydrocarbon group represented by R 5a , R 5b , R 5c and R 6 is, for example, a linear, branched or cyclic, saturated or unsaturated carbonized group having 1 to 20 carbon atoms. Hydrogen groups are mentioned, and among them, straight chain, branched or cyclic, saturated or unsaturated hydrocarbon groups having 1 to 12 carbon atoms are preferred.
• hydrocarbon group examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a cyclohexyl group, a dodecyl group, an octadecyl group, etc. ⁇ 20 linear, branched or cyclic saturated aliphatic hydrocarbon groups; aryl groups with 6 to 12 carbon atoms such as phenyl groups; arylalkyl groups with 7 to 10 carbon atoms such as benzyl groups and phenethyl groups, etc. can be mentioned.
• the hydrocarbon group which may be substituted with an alkoxy group represented by R 5c includes, for example, a group in which 1 to 3 of the hydrogen atoms of the above-mentioned hydrocarbon group are substituted with an alkoxy group. can be mentioned.
• the hydrocarbon group represented by R 7a , R 7b , R 8 and R 9 is, for example, a linear, branched or cyclic, saturated or unsaturated carbonized group having 1 to 20 carbon atoms. Hydrogen groups are mentioned, and among them, linear, branched or cyclic, saturated or unsaturated hydrocarbon groups having 1 to 12 carbon atoms are preferred.
• hydrocarbon group examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a cyclohexyl group, a dodecyl group, an octadecyl group, etc. ⁇ 20 linear, branched, or cyclic saturated aliphatic hydrocarbon groups; aryl groups with 6 to 12 carbon atoms such as phenyl groups; arylalkyl groups with 7 to 10 carbon atoms such as benzyl groups and phenethyl groups, etc. can be mentioned.
• R 8 and R 9 may form a pyrazole ring together with the nitrogen atom of formula (4).
• the pyrazole ring may be substituted with a saturated aliphatic hydrocarbon group having 1 to 3 carbon atoms or a chlorine atom.
• RAFT agents shown in formulas (1) to (4) When polymerization is carried out in the presence of the RAFT agents shown in formulas (1) to (4), radical species undergo a chain reaction between the sulfur atoms in the RAFT agent and the carbon atoms adjacent to the sulfur atoms, leading to polymerization. proceed.
• RAFT agents represented by formulas (1) and (2) are preferred from the viewpoint of ease of polymerization.
• RAFT agents are commercially available. Those that are not commercially available can be easily synthesized by known or conventional methods.
• RAFT agents include S-cyanomethyl-S-dodecyl trithiocarbonate, 2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propanoic acid, 2- ⁇ [(2-carboxyethyl)sulfanylthiocarbonyl]sulfanyl ⁇ propane.
• Dithioester ethyl 2-[(ethoxycarbonothioyl)thio]propionate, O-ethyl-S-(2-propoxyethyl)dithiocarbonate, O-ethyl-S-(1-cyano-1-methylethyl)dithio Dithiocarbonates such as carbonate; 2-cyano-2-propyldiethyldithiocarbamate, 2'-cyanobutan-2'-yl 4-chloro-3,5-dimethylpyrazole-1-dithiocarbamate, 2'-cyanobutane-2 Examples include dithiocarbamates such as '-yl 3,5-dimethylpyrazole-1-dithiocarbamate, cyanomethyl 3,5-dimethylpyrazole-1-dithiocarbamate, and cyanomethyl N-methyl-N-phenyldithiocarbamate.
• trithiocarbonate and dithioester are preferred from the viewpoint of ease of polymerization of the (meth)acrylic resin (A), and 2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propanoic acid, 2- ⁇ [(2 -carboxyethyl)sulfanylthiocarbonyl]sulfanyl ⁇ propanoic acid, 2-phenyl-2-propyldithiobenzoic acid, S,S-dibenzyltrithiocarbonate, and bis ⁇ 4-[ethyl-(2-acetyloxyethyl)carbamoyl) ]benzyl ⁇ trithiocarbonate is more preferred.
• RAFT agents may be used alone or in combination of two or more.
• radical polymerization initiator RAFT polymerization is preferably performed in the presence of a radical polymerization initiator.
• the radical polymerization initiator include ordinary organic radical polymerization initiators, specifically, for example, 2,2'-azobis(isobutyronitrile), 2,2'-azobis(4- methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane) -1-carbonitrile), 2,2'-azobis(2,4,4-trimethylpentane), dimethyl-2,2'-azobis(2-methylpropionate), and other azo polymerization initiators; and benzoyl Peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide, 1,1-bis(t-butyl hydro
• the radical polymerization initiators may be used alone or in combination of two or more.
• the amount of the radical polymerization initiator used is preferably 0.001 to 5 parts by mass, more preferably 0.005 to 3 parts by mass, based on 100 parts by mass of the total amount of the raw material monomer group (M). , more preferably 0.01 to 1 part by mass.
• solvent As the solvent used for RAFT polymerization, common solvents can be used.
• solvents include esters such as ethyl acetate, propyl acetate, and butyl acetate; aromatic hydrocarbons such as toluene, xylene, and benzene; aliphatic hydrocarbons such as hexane and heptane; and alicyclic carbonization such as cyclohexane and methylcyclohexane.
• Ketones such as methyl ethyl ketone and methyl isobutyl ketone
• Glycols such as ethylene glycol, propylene glycol and dipropylene glycol
• Glycol ethers such as methyl cellosolve, propylene glycol monomethyl ether and dipropylene glycol monomethyl ether
• ethylene glycol diacetate and propylene glycol examples include glycol esters such as monomethyl ether acetate.
• the solvents may be used alone or in combination of two or more.
• reaction temperature for RAFT polymerization depends on the type of radical polymerization initiator used, but is usually 30°C to 130°C, preferably 40°C to 120°C, more preferably 50°C to 110°C. preferable. When the temperature during RAFT polymerization is 30° C. or higher, a sufficient reaction rate can be obtained. When the temperature during RAFT polymerization is 130° C. or lower, there is little risk during production.
• the reaction time for RAFT polymerization depends on the raw material monomer group (M) used, the RAFT agent, and the type of radical polymerization initiator, but is usually 3 to 30 hours, preferably 4 to 20 hours. , more preferably from 5 hours to 15 hours.
• the reaction time is 3 hours or more, the copolymer (A-0) can be produced from the raw material monomer group (M) with an appropriate degree of polymerization, and when the reaction time is 30 hours or less, the copolymer (A-0) can be produced efficiently. Manufacturing can be carried out.
• the (meth)acrylic resin (A) is an ethylenically unsaturated compound containing an isocyanato group in a part of the side chain hydroxyl group derived from the hydroxyl group-containing (meth)acrylate (m-1) possessed by the copolymer (A-0). Obtained by adding (a).
• the isocyanato group-containing ethylenically unsaturated compound (a) is added to all of the side chain hydroxy groups of the copolymer (A-0), there will be no reaction sites with the crosslinking agent (C) described below, so the addition will be carried out only on the side chains. Only part of the hydroxyl group.
• (Meth)acrylic resin (A) has ethylenically unsaturated groups in its side chains, so compared to (meth)acrylic copolymers with ethylenically unsaturated groups introduced at the ends, the molecular chain between crosslinking points is The length is relatively short, and the adhesive force can be greatly reduced after UV irradiation.
• a pressure-sensitive adhesive sheet using (meth)acrylic resin (A) has excellent releasability from an adherend.
• the adhesive composition manufactured using the methacrylic resin (A) has excellent adhesion to the adhesive layer. have Therefore, the adhesive composition manufactured using the (meth)acrylic resin (A) is suitably used in the adhesive layer of the dicing/die-bonding integrated film.
• the molecular weight distribution (Mw/Mn) of the (meth)acrylic resin (A) is preferably 2.4 or more, more preferably 2.5 or more, and still more preferably 3.0 or more.
• the molecular weight distribution of the (meth)acrylic resin (A) is preferably 10.0 or less, more preferably 6.0 or less, still more preferably 5.8 or less, even more preferably 5.6 or less. Any combination of these lower limit values and upper limit values may be used.
• the molecular weight distribution of the (meth)acrylic resin (A) is preferably 2.4 to 10.0, more preferably 2.4 to 6.0, still more preferably 2.5 to 5.8, even more preferably 3. It is 0 to 5.6.
• the molecular weight distribution is 2.4 or more, the wettability of the pressure-sensitive adhesive composition containing the (meth)acrylic resin (A) is improved, and the adhesiveness to the adherend, especially the adhesive layer, is good.
• the molecular weight distribution is 10.0 or less, the (meth)acrylic resin (A) in the high molecular weight region falls within an appropriate range, making it easy to control the viscosity of the adhesive composition, and the (meth)acrylic resin (A) in the low molecular weight region falls within an appropriate range. ) By keeping the acrylic resin (A) within an appropriate range, adhesive residue is suppressed when the adhesive sheet is peeled off from the adherend.
• the weight average molecular weight (Mw) of the (meth)acrylic resin (A) is preferably 100,000 or more, more preferably 150,000 or more, still more preferably 200,000 or more, even more preferably 300,000 or more.
• the weight average molecular weight of the (meth)acrylic resin (A) is preferably 800,000 or less, more preferably 700,000 or less, even more preferably 650,000 or less. Any combination of these lower limit values and upper limit values may be used.
• the weight average molecular weight (Mw) of the (meth)acrylic resin (A) is preferably 100,000 to 800,000, more preferably 150,000 to 700,000, and even more preferably 200,000 to 650. ,000, more preferably 300,000 to 650,000.
• the weight average molecular weight is 100,000 or more, the peelability after UV irradiation is improved.
• the weight average molecular weight is 800,000 or less, the viscosity of the adhesive composition containing the (meth)acrylic resin (A) can be appropriately suppressed, and the workability of the adhesive composition can be improved.
• the ethylenically unsaturated group equivalent of the (meth)acrylic resin (A) is preferably 100 to 3,000 g/mol, more preferably 300 to 2,500 g/mol, even more preferably 500 to 2,000 g /mol. Within the above range, the amount of crosslinking of the adhesive composition during UV irradiation is sufficient, and the adhesive sheet produced using the (meth)acrylic resin (A) has excellent properties when peeled from the adherend. Excellent peelability and pick-up of small pieces of elements can be obtained.
• the ethylenically unsaturated group equivalent of the (meth)acrylic resin (A) is the mass of the (meth)acrylic resin (A) per mole of ethylenically unsaturated bonds.
• the ethylenically unsaturated group equivalent of the (meth)acrylic resin (A) in one embodiment is calculated from the amount charged, assuming that each raw material used in the production of the (meth)acrylic resin (A) has reacted 100%. This is the calculated value.
• the ethylenically unsaturated group equivalent of the (meth)acrylic resin (A) may be calculated from the amount of halogen bonded to the (meth)acrylic resin (A).
• the amount of halogen bonded to the (meth)acrylic resin (A) can be evaluated according to JIS K 0070:1992.
• the glass transition temperature (Tg) of the (meth)acrylic resin (A) is preferably -80°C to 0°C, more preferably -70°C to -10°C, even more preferably -60°C to -30°C. It is °C.
• Tg glass transition temperature
• Tg glass transition temperature
• the acid value of the (meth)acrylic resin (A) is preferably 0.5 to 100 mgKOH/g, more preferably is 1.0 to 50 mgKOH/g, more preferably 3.0 to 25 mgKOH/g.
• the acid value is 0.5 mgKOH/g or more, a sufficient amount of crosslinking can be ensured when a polyepoxy compound is used as the crosslinking agent (C), and a sufficient cohesive force of the adhesive layer can be ensured.
• the acid value is 100 mgKOH/g or less, the storage stability of the adhesive composition is good.
• the acid value is a value measured according to JIS K 0070:1992.
• the isocyanato group-containing ethylenically unsaturated compound (a) is not particularly limited as long as it is a compound that does not have a hydroxyl group or a carboxy group and has an isocyanato group and an ethylenically unsaturated group.
• (meth)acrylic resin (A) (meth)acryloyloxyalkyl isocyanate is preferred, and 2-isocyanatoethyl (meth)acrylate is more preferred.
• the content of the isocyanato group-containing ethylenically unsaturated compound (a) is preferably 0.25 mol or more, more preferably 0.50 mol or more, still more preferably 1. It is 0 or more.
• the content of the isocyanato group-containing ethylenically unsaturated compound (a) is preferably 49 mol or less, more preferably 47 mol or less, still more preferably 45 mol or less. Any combination of these lower limit values and upper limit values may be used.
• the content of the isocyanato group-containing ethylenically unsaturated compound (a) is preferably 0.25 to 49 mol, more preferably 0.50 to 47 mol, per 100 mol of the raw material monomer group (M).
• the content of the isocyanato group-containing ethylenically unsaturated compound (a) is 0.25 mol or more, a sufficient amount of ethylenically unsaturated groups will be introduced into the (meth)acrylic resin (A), and the pressure-sensitive adhesive sheet will be formed after UV irradiation. It is possible to obtain better releasability when peeling off from an adherend.
• the content of the isocyanato group-containing ethylenically unsaturated compound (a) is 49 mol or less, a sufficient content of hydroxyl groups in the (meth)acrylic resin (A) can be ensured, resulting in an excellent adhesive layer. A cohesive force can be obtained.
• the amount of unreacted isocyanato group-containing ethylenically unsaturated compound (a) can be reduced, a pressure-sensitive adhesive sheet with less adhesive residue can be obtained.
• a known catalyst can be used as necessary.
• a urethanization catalyst such as dibutyltin dilaurate, titanium diisopropoxy bis(ethyl acetoacetate), tetrakis(2,4-pentanedionato)zirconium, bismuth tris(2-ethylhexanoate) is used. be able to.
• the amount of the catalyst used is 0.01 parts by mass based on the total of 100 parts by mass of the copolymer (A-0) and the isocyanato group-containing ethylenically unsaturated compound (a). It is preferably from 10 parts by weight, more preferably from 0.02 to 5 parts by weight, even more preferably from 0.03 to 1 part by weight.
• a known polymerization inhibitor in the addition reaction in step (ii), a known polymerization inhibitor can be used as necessary.
• Known polymerization inhibitors can be used and are not particularly limited, but examples include 4-methoxyphenol, hydroquinone, methoquinone, 2,6-di-t-butylphenol, and 2,2'-methylenebis( (4-methyl-6-t-butylphenol) and phenothiazine. Polymerization inhibitors may be used alone or in combination of two or more.
• the amount of the polymerization inhibitor used is based on the total of 100 parts by mass of the copolymer (A-0) and the isocyanato group-containing ethylenically unsaturated compound (a). , preferably 0.005 to 5 parts by weight, more preferably 0.03 to 3 parts by weight, and even more preferably 0.05 to 1.5 parts by weight. If the amount of the polymerization inhibitor used is 0.005 parts by mass or more, gelation during the addition reaction can be prevented. On the other hand, if the amount of the polymerization inhibitor used is 5 parts by mass or less, sufficient exposure sensitivity of the (meth)acrylic resin (A) upon UV irradiation can be obtained.
• the temperature of the addition reaction is preferably 25°C to 130°C, particularly preferably 40°C to 120°C. When the temperature of the addition reaction is 25° C. or higher, a sufficient reaction rate can be obtained. When the temperature of the addition reaction is 130° C. or lower, it is possible to prevent double bonds from being crosslinked due to radical polymerization due to heat and from forming a gelled product.
• a gas having a polymerization inhibiting effect may be introduced into the reaction system.
• a gas having a polymerization inhibiting effect By introducing a gas having a polymerization inhibiting effect into the reaction system, gelation during the addition reaction can be prevented.
• gases that have a polymerization inhibiting effect include gases that contain oxygen to an extent that does not fall within the explosive range of substances in the system, such as air.
• the adhesive composition is prepared by mixing the (meth)acrylic resin (A), the photopolymerization initiator (B), the crosslinking agent (C), and other components added as necessary (iii). It can be manufactured by a method including.
• the pressure-sensitive adhesive composition containing the (meth)acrylic resin (A) is suitably used for removable pressure-sensitive adhesive sheets, particularly for dicing and die-bonding integrated films.
• the method of mixing each component contained in the adhesive composition is not particularly limited. Mixing can be performed using, for example, a stirring device equipped with a stirring blade such as a homodisper or a paddle blade.
• Photopolymerization initiator (B) examples include benzophenone, benzyl, benzoin, ⁇ -bromoacetophenone, chloroacetone, acetophenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, p-dimethyl Aminoacetophenone, p-dimethylaminopropiophenone, 2-chlorobenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bisdiethylaminobenzophenone, Michler's ketone, benzoin methyl ether, benzoin isobutyl ether, benzoin-n-butyl ether, benzyl Methyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-(4-isopropylphenyl)-2-hydroxy
• Examples of the photopolymerization initiator (B) include sulfide photopolymerization initiators such as diphenyl disulfide, dibenzyl disulfide, tetraethylthiuram disulfide, and tetramethylammonium monosulfide; 2,4,6-trimethylbenzoyldiphenylphosphine oxide; , acylphosphine oxides such as 4,6-trimethylbenzoylphenylethoxyphosphine oxide; quinone-based photopolymerization initiators such as benzoquinone and anthraquinone; sulfochloride-based photopolymerization initiators; and thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, etc. Also included are thioxanthone photopolymerization initiators.
• sulfide photopolymerization initiators such as diphenyl disulfide, dibenzyl dis
• photoinitiators (B) carbonyl photoinitiators and acylphosphine oxides are preferred from the viewpoint of solubility in the adhesive composition, and 1-hydroxycyclohexylphenyl ketone and 2,4, It is more preferable to use at least one selected from 6-trimethylbenzoyldiphenylphosphine oxide.
• the photopolymerization initiator (B) may be used alone or in combination of two or more types.
• the photopolymerization initiator (B) is preferably 0.1 to 5.0 parts by mass, and 0.5 to 2.0 parts by mass, based on 100 parts by mass of the (meth)acrylic resin (A). It is more preferable.
• the content of the photopolymerization initiator (B) is 0.1 parts by mass or more based on 100 parts by mass of the (meth)acrylic resin (A)
• the adhesive composition can be cured at a sufficiently fast curing rate during UV irradiation. Therefore, the adhesive force of the adhesive layer after UV irradiation can be sufficiently reduced.
• the adhesive sheet having the adhesive layer containing the adhesive composition cannot be adhered.
• the adhesive layer is peeled off after being attached to the body, the adhesive layer is less likely to remain on the adherend. Even if the content of the photopolymerization initiator (B) exceeds 5.0 parts by mass with respect to 100 parts by mass of the (meth)acrylic resin (A), no effect commensurate with the content of the photopolymerization initiator (B) is observed. Therefore, by setting the content to 5.0 parts by mass or less, the adhesive composition can be economically produced.
• the crosslinking agent (C) is a compound having no ethylenically unsaturated bond, and is a functional compound that reacts with the hydroxy group contained in the (meth)acrylic resin (A) and/or the optionally contained functional group carboxyl group. A compound having two or more groups.
• the crosslinking agent (C) is not particularly limited, but a compound having two or more functional groups reactive with hydroxyl groups is preferred.
• a compound having two or more functional groups reactive with the carboxy group may be used.
• the functional group having reactivity with a hydroxy group include an isocyanato group, an epoxy group, a carboxy group, an acid anhydride group, an aziridinyl group, and from the viewpoint of reactivity, an isocyanato group and an epoxy group are preferable. Particularly preferred is an isocyanato group.
• the functional group having reactivity with a carboxyl group include an epoxy group, a hydroxy group, and an aziridinyl group. From the viewpoint of reactivity, an epoxy group and an aziridinyl group are preferable.
• crosslinking agent (C) examples include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hydrogenated tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane- 4,4'-diisocyanate, isophorone diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, isocyanurate of hexamethylene diisocyanate, tetramethylxylylene diisocyanate, 1,5-naphthalene diisocyanate, tolylene diisocyanate of trimethylolpropane Adducts, polyisocyanates such as xylylene diisocyanate adducts of trimethylolpropane, triphenylmethane triisocyanate, methylenebis(4-phenylmethane)triisocyanate; 1,3-bis(N
• crosslinking agents (C) it is preferable to use at least one selected from the group consisting of polyisocyanates and polyepoxy compounds because of its good reactivity with the (meth)acrylic resin (A). , it is more preferable to use polyisocyanate.
• the crosslinking agent (C) may be used alone or in combination of two or more.
• the crosslinking agent (C) is preferably 0.1 to 30 parts by weight, more preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the (meth)acrylic resin (A), and The amount is more preferably .1 to 10 parts by weight, and even more preferably 0.1 to 5 parts by weight.
• the content of the crosslinking agent (C) is 0.1 parts by mass or more based on 100 parts by mass of the (meth)acrylic resin (A)
• a three-dimensional crosslinked structure is sufficiently formed in the adhesive composition during UV irradiation. , the adhesive force of the adhesive composition after UV irradiation can be sufficiently reduced.
• the content of the crosslinking agent (C) is 30 parts by mass or less with respect to 100 parts by mass of the (meth)acrylic resin (A)
• the adhesive strength of the adhesive composition before UV irradiation is good.
• other ingredients in the method for producing an adhesive composition, other components than the (meth)acrylic resin (A), the photopolymerization initiator (B), and the crosslinking agent (C) may be mixed as necessary.
• other components include tackifiers, solvents, and various additives.
• tackifier As the tackifier, conventionally known tackifiers can be used without particular limitation. Examples of tackifiers include terpene-based tackifier resins, phenolic tackifier resins, rosin-based tackifier resins, aliphatic petroleum resins, aromatic petroleum resins, copolymer petroleum resins, and alicyclic petroleum resins. , xylene resin, epoxy tackifier resin, polyamide tackifier resin, ketone tackifier resin, and elastomer tackifier resin. These tackifiers may be used alone or in combination of two or more.
• the amount added is preferably 30 parts by mass or less, more preferably 5 to 20 parts by mass, based on 100 parts by mass of the (meth)acrylic resin (A).
• solvent can be used to dilute the adhesive composition for the purpose of adjusting the viscosity of the adhesive composition.
• a solvent can be used to adjust the viscosity of the pressure-sensitive adhesive composition to an appropriate viscosity.
• organic solvents such as methyl ethyl ketone, methyl isobutyl ketone, acetone, ethyl acetate, propyl acetate, tetrahydrofuran, dioxane, cyclohexanone, hexane, toluene, xylene, n-propanol, and isopropyl alcohol can be used.
• organic solvents such as methyl ethyl ketone, methyl isobutyl ketone, acetone, ethyl acetate, propyl acetate, tetrahydrofuran, dioxane, cyclohexanone, hexane, toluene, xylene, n-propanol, and isopropyl alcohol can be used.
• solvents may be used alone or in combination of two or more.
• additives include plasticizers, surface lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, benzotriazole-based light stabilizers, and phosphorus.
• additives include acid ester and other flame retardants, surfactants, and antistatic agents.
• the adhesive sheet can be manufactured, for example, by the method shown below.
• an adhesive solution is prepared by dissolving or dispersing the adhesive composition in a solvent.
• the adhesive composition may be used as it is as an adhesive solution.
• an adhesive solution is applied onto the base material, and if it contains a solvent, the solvent is removed by heating and drying to form an adhesive layer. Thereafter, a release sheet is laminated on the adhesive layer, if necessary. Furthermore, a pressure-sensitive adhesive sheet can be obtained by curing the obtained sheet in an oven for a certain period of time to form a crosslinked structure, if necessary.
• the adhesive sheet can also be manufactured by the method shown below.
• a pressure-sensitive adhesive solution is applied onto a release sheet, and if it contains a solvent, the solvent is removed by heating and drying to form a pressure-sensitive adhesive layer.
• a release sheet having an adhesive layer is placed on the base material with the adhesive layer side facing the base material, and the adhesive layer is transferred (transferred) onto the base material.
• a pressure-sensitive adhesive sheet can be obtained by curing the obtained sheet in an oven for a certain period of time to form a crosslinked structure, if necessary.
• a base material having an adhesive layer is used as a base material, and the adhesive composition is applied to the adhesive layer, or the adhesive layer and the adhesive layer are laminated so as to face each other, thereby performing dicing.
• a die bonding integrated film can be obtained.
• a known method can be used to apply the adhesive solution onto the base material (or onto the release sheet).
• examples include coating methods using conventional coaters, such as gravure roll coater, reverse roll coater, kiss roll coater, dip roll coater, bar coater, knife coater, spray coater, comma coater, and direct coater. It will be done.
• Conditions for heating and drying the applied adhesive solution are not particularly limited, but heating and drying is usually carried out at 25 to 180°C, preferably 60 to 150°C, for 1 to 20 minutes, preferably 1 to 10 minutes. . By performing heat drying in the above range, the solvent contained in the adhesive solution can be removed.
• the conditions for curing the heated and dried sheet in an oven for a certain period of time are not particularly limited, but the curing is usually carried out at 25 to 100°C, preferably 30 to 80°C, for 1 to 30 days, preferably 1 to 14 days.
• the (meth)acrylic resin (A) can be crosslinked with the crosslinking agent (C), and the gel fraction of the adhesive layer can be adjusted to a desired range.
• the adhesive sheet can be used as a removable adhesive sheet, for example, when manufacturing electronic components. Specifically, a removable adhesive sheet is used to fix an adherend in each step of manufacturing electronic components, and after subjecting it to various processing steps, irradiates the adherend with UV (ultraviolet light). Used for peeling from. Therefore, the adhesive sheet can be used as a backgrind tape, dicing tape, etc. when processing semiconductor wafers.
• the adhesive sheet can also be used as a support tape for fragile members such as ultra-thin glass substrates and easily warped members such as FPC boards.
• the adhesive sheet has excellent adhesion to the adhesive layer and excellent releasability after UV irradiation, and is therefore suitable for a dicing tape used when manufacturing a dicing/die bonding integrated film.
• the adhesive sheet When using an adhesive sheet as a dicing tape for a wafer, the adhesive sheet is attached to the wafer on which multiple parts are formed before performing the dicing process. Next, the wafer is cut and diced into individual parts to form small element pieces (chips). Thereafter, UV irradiation is applied to the adhesive sheet pasted on each element piece. As a result, the adhesive layer is irradiated with UV light through the base material of the adhesive sheet, and the unsaturated bonds in the adhesive form a three-dimensional crosslinked structure and are cured. As a result, the adhesive force of the adhesive layer decreases. Thereafter, the adhesive sheet is peeled off from above each element piece.
• Examples of light sources used when performing UV irradiation include high-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, xenon lamps, metal halide lamps, chemical lamps, and black lights.
• the amount of UV irradiation applied to the adhesive sheet is preferably 50 to 3,000 mJ/cm 2 , more preferably 100 to 600 mJ/cm 2 .
• the adhesive layer can be cured at a sufficiently fast curing speed by UV irradiation, so the adhesive strength of the adhesive layer after UV irradiation is can be made sufficiently small.
• (meth)acrylic resins (A) and (cA) are shown below.
• Hydroxy group-containing (meth)acrylate (m-1) 2-Hydroxyethyl acrylate, Nippon Shokubai Co., Ltd. 2-Hydroxyethyl methacrylate, Nippon Shokubai Co., Ltd. 4-Hydroxybutyl acrylate, Osaka Organic Chemical Industry Co., Ltd.
• RAFT agent 2- “(dodecylsulfanylthiocarbonyl)sulfanyl” propanoic acid, Fujifilm Wako Pure Chemical Industries, Ltd. Bis ⁇ 4-[ethyl-(2-hydroxyethyl)carbamoyl]benzyl ⁇ trithiocarbonate, Fujifilm Wako Pure Chemical Industries, Ltd. S,S-dibenzyltrithiocarbonate, Fujifilm Wako Pure Chemical Industries, Ltd. 2-phenyl-2-propyldithiobenzoic acid, Ouchi Shinko Chemical Co., Ltd. additive: Ethyl 2-methyl-2-n-butylterranyl-propionate, Otsuka Chemical Co., Ltd.
• Isocyanato group-containing ethylenically unsaturated compound (a): Karenz (trademark) MOI, 2-isocyanatoethyl methacrylate, Showa Denko K.K. AOI-VM (trademark), 2-isocyanatoethyl acrylate, Showa Denko K.K.
• (meth)acrylic resins (A) and (cA) Synthesis examples of (meth)acrylic resins (A) and (cA) are shown below.
• the weight average molecular weight, molecular weight distribution, acid value, and glass transition temperature of the (meth)acrylic resins (A) and (cA) were measured and calculated using the methods described above.
• the ethylenically unsaturated group equivalents of the (meth)acrylic resins (A) and (cA) were calculated from the charged amounts as described above.
• the hydroxyl value is the mass (mg) of potassium hydroxide required to neutralize acetic acid bonded to hydroxyl groups when 1 g of resin is acetylated, according to JIS K 0070:1992.
• Table 1 shows the weight average molecular weight, molecular weight distribution, ethylenically unsaturated group equivalent, hydroxyl value, acid value, and glass transition temperature of the (meth)acrylic resins (A) and (c
• the temperature of the reactant was lowered to 60°C, and a mixed solution of 16.5 parts by mass (10.6 mol) of 2-isocyanatoethyl methacrylate and 0.18 parts by mass of dibutyltin dilaurate, which is a urethanization catalyst, was added through the dropping funnel. dripped. After the dropwise addition was completed, the reaction system was maintained at 70° C. for 4 hours to eliminate the isocyanate groups.
• Synthesis Example 1 was carried out in the same manner as in Synthesis Example 1, except that ethyl 2-methyl-2-n-butylterranyl-propionate was used instead of 2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propanoic acid and the composition shown in Table 1 was used.
• a (meth)acrylic resin (cA2) was obtained.
• TETRAD-X N,N'-[1,3-phenylenebis(methylene)]bis[bis(oxiran-2-ylmethyl)amine] (manufactured by Mitsubishi Gas Chemical Co., Ltd., product name: TETRAD-X)
• the (meth)acrylic resin (A) or (cA) shown in Table 2, the photopolymerization initiator (B), and the crosslinking agent (C) shown in Table 2 were placed in a plastic container in a room blocked from active rays. The indicated content (parts by mass) was added and stirred to obtain adhesive compositions (B1) to (B4) and (cB1) to (cB3).
• the numerical values of (meth)acrylic resins (A1) to (A4) and (meth)acrylic resins (cA1) to (cA3) in Table 2 are based on the solid content of the solutions used, that is, (meth)acrylic resins (A1) to ( A4) and the amounts used (parts by mass) of (cA1) to (cA3).
• the numerical value of the photopolymerization initiator (B) is the amount (parts by mass) of the photopolymerization initiator (B) used per 100 parts by mass of the (meth)acrylic resin (A) or (cA).
• the numerical value of the crosslinking agent (C) is the amount (parts by mass) of the crosslinking agent (C) used per 100 parts by mass of the (meth)acrylic resin (A) or (cA).
• Example 2-1 Preparation of adhesive sheet A silicone-based light release PET film (Toyobo Co., Ltd., product name: E7006, thickness 25 ⁇ m) was prepared as a separator, and the release-treated surface was The adhesive composition (B1) was applied using an applicator so that the thickness after curing was 20 ⁇ m, and the adhesive composition was dried by heating at 100° C. for 2 minutes to form an adhesive layer. Next, a 90 ⁇ m thick PO film was prepared as a sheet-like base material. The PO film was attached to the adhesive layer using a rubber roller so that the corona-treated surface of the PO film adhered to the exposed surface of the adhesive layer. The pressure-sensitive adhesive sheet of Example 2-1 was obtained by curing in an oven at 40° C. for 3 days to crosslink and cure the pressure-sensitive adhesive layer.
• Example 2-2 to 2-4 and Comparative Examples 2-1 to 2-3 Production of adhesive sheets Except for using the adhesive composition shown in Table 2 instead of the adhesive composition (B1) Adhesive sheets of Examples 2-2 to 2-4 and Comparative Examples 2-1 to 2-3 were obtained in the same manner as in Example 2-1.
• the measurement conditions were a peel angle of 30° and a tensile speed of 600 mm/min.
• the storage of the samples and the measurement of peel strength were performed under an environment of a temperature of 23° C. and a relative humidity of 40%. Table 2 shows the results.
• the silicon wafer after stealth dicing was polished to a thickness of 30 ⁇ m.
• a grinder polisher device (DGP8761, DISCO Co., Ltd.) was used for polishing.
• An adhesive layer of a dicing/die bonding integrated film was attached to the polished silicon wafer under the following conditions with the base side surface of the dicing tape facing the dicing ring. Thereafter, the BG tape was peeled off from the surface of the silicon wafer.
• ⁇ Pasting conditions> ⁇ Packing device: DFM2800 (Disco Co., Ltd.) ⁇ Application temperature: 70°C ⁇ Application speed: 10mm/s ⁇ Application tension level: Level 6
• the silicon wafer and the adhesive layer were diced into a plurality of chips with adhesive chips (size: 10 mm x 10 mm).
• ⁇ Cooling expansion conditions > ⁇ Cooling temperature: -15°C ⁇ Cooling time: 120 seconds ⁇ Push-up amount: 12mm ⁇ Push-up speed: 200mm/sec ⁇ Holding time after push-up: 3 seconds ⁇ Heat shrink conditions> ⁇ Heater temperature: 220°C ⁇ Heater rotation speed: 5°/sec ⁇ Listing amount: 8mm ⁇ Tape cooling waiting time: 10 seconds
• the adhesive layer was irradiated with ultraviolet rays from the surface of the adhesive sheet on the base material side under the following conditions. This cured the adhesive layer and reduced the adhesive force to the adhesive layer.
• DAF jump Evaluation of processability (DAF jump) After cooling expansion and heat shrinking, DAF jump was evaluated according to the following criteria. Table 2 shows the results. A: DAF jump did not occur at all. B: DAF did not fly, but peeling or lifting was observed at the interface between the adhesive layer and the pressure-sensitive adhesive layer. C: DAF skipping occurred in at least one location.
• the interval (kerf width) between the chips with adhesive chips after singulation was measured using a microscope.
• the kerf width in the MD/TD direction was measured at two locations each on the outer periphery (top, bottom, left and right) of the silicon wafer and at one location in the center (total of 18 points), and the average value was determined. Evaluation was made based on the following criteria. Table 2 shows the results.
• A The average value of the kerf width was 70 ⁇ m or more and less than 100 ⁇ m.
• B The average value of the kerf width was 50 ⁇ m or more and less than 70 ⁇ m.
• Kerf width is one of the important items in the stealth dicing process from the viewpoint of achieving excellent pick-up properties.
• chip edge peeling occurred after cooling expansion and heat shrinking, and pickup failure also occurred.
• Comparative Example 2-2 which used a (meth)acrylic resin obtained from a copolymer produced by organic tellurium radical polymerization, had a small amount of low molecular weight components and insufficient propagation of breaking stress, resulting in adhesive layer separation.
• the gender was D.
• a (meth)acrylic resin suitable for an adhesive composition is provided.
• a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition produced using a (meth)acrylic resin can be preferably used as a pressure-sensitive adhesive layer of a removable pressure-sensitive adhesive sheet, particularly a dicing/die-bonding integrated film.

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