WO2024117223A1 - Pressure-sensitive adhesive sheet and method for producing laminate - Google Patents

Pressure-sensitive adhesive sheet and method for producing laminate Download PDF

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Publication number
WO2024117223A1
WO2024117223A1 PCT/JP2023/042945 JP2023042945W WO2024117223A1 WO 2024117223 A1 WO2024117223 A1 WO 2024117223A1 JP 2023042945 W JP2023042945 W JP 2023042945W WO 2024117223 A1 WO2024117223 A1 WO 2024117223A1
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Prior art keywords
adhesive sheet
meth
pressure
sensitive adhesive
acrylate
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PCT/JP2023/042945
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French (fr)
Japanese (ja)
Inventor
晋治 河田
義和 増山
千春 奥原
涼馬 石立
拓身 木田
雄大 緒方
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積水化学工業株式会社
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Publication of WO2024117223A1 publication Critical patent/WO2024117223A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • 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
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/06—Non-macromolecular additives organic
    • 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
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/08—Macromolecular additives
    • 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
    • C09J201/00—Adhesives based on unspecified macromolecular compounds
    • 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
    • C09J4/00—Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16
    • 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]

Definitions

  • the present invention relates to an adhesive sheet.
  • the present invention also relates to a method for producing a laminate having the adhesive sheet.
  • Adhesives are used to bond electronic components inside electronic devices such as smartphones and PCs.
  • an adhesive sheet is first prepared with separators on both sides of the adhesive, and then the adhesive sheet is cut into the desired shape.
  • One separator is then peeled off from the cut adhesive sheet, and one side of the exposed adhesive is bonded to a first adherend, and then the other separator is peeled off, and the other side of the exposed adhesive is bonded to a second adherend.
  • part of the adhesive sheet is discarded after cutting, generating waste. Also, air bubbles can sometimes get into the bonded surfaces.
  • Patent Document 1 discloses an invention for providing a radiation-curable adhesive composition that allows fine patterning and exhibits high adhesion to various adherends such as metals and plastics.
  • Patent Document 1 describes a radiation-curable adhesive composition that contains 10 to 70% by weight of an ethylenically unsaturated monomer that does not contain an aromatic ring, 1 to 10% by weight of a photopolymerization initiator, and 10 to 55% by weight of a crosslinking agent.
  • Patent Document 2 discloses an invention for providing a photocurable adhesive composition that, even when irradiated with light in the presence of oxygen, gives a laminate having adhesive strength equivalent to that in the absence of oxygen.
  • Patent Document 2 describes a photocurable adhesive composition that contains (A) a (meth)acrylate oligomer, (B) a monofunctional (meth)acrylic monomer, (C) a di- to tetrafunctional (meth)acrylic monomer, (D) a photoinitiator, (E) a tackifier having a softening point of 70 to 150°C, and (F) a liquid plasticizer.
  • the method of printing the adhesive composition in a desired shape, forming an adhesive sheet, and laminating it to an adherend without preparing an adhesive sheet in advance can suppress the generation of waste and prevent air bubbles from being introduced into the lamination surface.
  • ultraviolet curing is desirable from the viewpoint of avoiding heating of the adherend and reducing CO2 emissions, but the adhesive sheet obtained by ultraviolet curing has a problem of poor impact resistance.
  • the present invention aims to provide an adhesive sheet that is obtained by UV curing and has excellent impact resistance.
  • the present invention also aims to provide a method for producing a laminate having the adhesive sheet.
  • Disclosure 1 is a pressure-sensitive adhesive sheet that is a cured product of a pressure-sensitive adhesive composition containing a photopolymerization initiator, and in a viscoelasticity chart obtained by performing dynamic viscoelasticity measurement under conditions of a shear method, a measurement temperature of -70°C to 200°C, and a frequency of 1 Hz, when Ggtemp is the temperature at which the loss modulus is maximized on the lowest temperature side, Tg is the lowest temperature among the temperatures at which tan ⁇ is maximized in a region higher than Ggtemp, GF1temp is the lowest temperature in a temperature region from Tg to 50°C among the temperatures at which the ratio of storage modulus to loss modulus is minimum, GF2temp is the lowest temperature among the temperatures at which the loss tangent is minimized in a region higher than GF1temp, and GF2tan ⁇ is the loss tangent at GF2temp, the temperature difference between Ggtemp and GF1temp is 25.0°C or more, and GF2tan
  • Disclosure 2 is a pressure-sensitive adhesive sheet according to Disclosure 1, in which, when GEtemp is the temperature at which the storage modulus becomes a minimum value in a region higher than the GF2temp in the viscoelasticity chart, or 200°C if there is no temperature at which the storage modulus becomes a minimum value in a region higher than the GF2temp, the loss tangent at the GEtemp is GEtan ⁇ , and delta tan ⁇ is a value calculated by the formula (GEtan ⁇ -GF2tan ⁇ )/(GEtemp-GF2temp), the delta tan ⁇ is -0.006 or more.
  • the present disclosure 3 is the pressure-sensitive adhesive sheet of the present disclosure 1 or 2, in which the temperature difference between the Ggtemp and the GF1temp is 50.0°C or more.
  • the present disclosure 4 is the pressure-sensitive adhesive sheet of the present disclosure 1, 2, or 3, in which the GF2 tan ⁇ is 0.50 or more.
  • the present disclosure 5 is the pressure-sensitive adhesive sheet according to claim 1, 2, 3 or 4, wherein the pressure-sensitive adhesive sheet has a 180° peel adhesive strength to a SUS substrate at 25°C of 6 N/cm or more after being aged for one day in an environment of 25°C and 50% RH.
  • the present disclosure 6 is the pressure-sensitive adhesive sheet according to the present disclosure 1, 2, 3, 4, or 5, wherein the pressure-sensitive adhesive composition contains a nitrogen-containing compound.
  • the present disclosure 7 is the pressure-sensitive adhesive sheet according to the present disclosure 6, wherein the nitrogen-containing compound includes a maleimide derivative.
  • the present disclosure 8 is the pressure-sensitive adhesive sheet of the present disclosure 1, 2, 3, 4, 5, 6, or 7, wherein the pressure-sensitive adhesive composition comprises at least one selected from the group consisting of a hydrogen abstraction type photopolymerization initiator and a polymer type photopolymerization initiator.
  • the present disclosure 9 is the pressure-sensitive adhesive sheet according to the present disclosure 1, 2, 3, 4, 5, 6, 7, or 8, wherein the pressure-sensitive adhesive composition contains a thermoplastic resin.
  • the present disclosure 10 is the PSA sheet of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, or 9, wherein the PSA composition contains a tackifier.
  • Disclosure 11 is a method for producing a laminate in which the adhesive composition is partially coated on the first adherend, the method comprising the steps of coating the adhesive composition on a first adherend or a separator and exposing the composition to light to form an adhesive sheet according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, and attaching a second adherend to the adhesive sheet, the method for coating the adhesive composition being inkjet printing, screen printing, spray coating, spin coating, gravure offset, or reverse offset printing.
  • the present invention will be described in detail below.
  • the present inventors have investigated how to make a viscoelasticity chart obtained by performing dynamic viscoelasticity measurement under specific conditions on an adhesive sheet obtained by UV curing an adhesive composition exhibit specific behavior. As a result, they have found that an adhesive sheet with excellent impact resistance can be obtained, leading to the completion of the present invention.
  • the lowest temperature at which the loss modulus is maximum on the lowest temperature side is defined as Ggtemp and the lowest temperature at which tan ⁇ is maximum in a region higher than Ggtemp is defined as Tg
  • the lowest temperature at which the ratio of the storage modulus to the loss modulus is minimum in a temperature region from Tg to 50°C is defined as GF1temp
  • the lowest temperature at which the loss tangent is minimum in a region higher than GF1temp is defined as GF2temp
  • the loss tangent at GF2temp is defined as GF2tan ⁇
  • the lower limit of the temperature difference between Ggtemp and GF1temp is 25.0°C
  • the lower limit of GF2tan ⁇ is 0.34.
  • FIG. 1 A schematic diagram showing the relationship between the Ggtemp, GF1temp, GF2temp, and GF2tan ⁇ in a viscoelasticity chart is shown in Figure 1.
  • the preferred lower limit of the temperature difference between Ggtemp and GF1temp is 40.0° C., and the more preferred lower limit is 50.0° C.
  • there is no particular preferred upper limit of the temperature difference between Ggtemp and GF1temp but the substantial upper limit is 120.0° C.
  • the preferred lower limit of GF2 tan ⁇ is 0.50.
  • the substantial upper limit is 4.0.
  • the loss tangent at the GEtemp is GEtan ⁇
  • the value calculated by the formula (GEtan ⁇ -GF2tan ⁇ )/(GEtemp-GF2temp) is delta tan ⁇
  • the preferred lower limit of the delta tan ⁇ is -0.006.
  • the pressure-sensitive adhesive sheet has better impact resistance.
  • the more preferred lower limit of the delta tan ⁇ is 0.002.
  • the substantial upper limit is 0.5.
  • the viscoelasticity chart can be obtained by performing dynamic viscoelasticity measurement under the following conditions using a dynamic viscoelasticity measuring device, for example, MCR-702e (manufactured by Anton Paar) or the like.
  • a dynamic viscoelasticity measuring device for example, MCR-702e (manufactured by Anton Paar) or the like.
  • Shear method Measured with twin drive using 8 mm parallel plate Measurement temperature: -70°C to 200°C Heating rate: 7°C/min Frequency: 1Hz While cooling from 50°C to -70°C at a rate of 10°C/min, pre-pressure was applied at 8N, and measurements were taken from the low temperature as described below in (1) to (6).
  • the temperature is raised with a normal force of 1 N and a strain of 10%, and measurements are performed under these conditions until the temperature reaches 200° C. (6)
  • the measurement is terminated. If the storage modulus does not reach a minimum point up to this point, 200° C. or the temperature at the end of the measurement becomes the GEtemp.
  • the pressure-sensitive adhesive sheet of the present invention has a glass transition temperature of preferably ⁇ 30° C. at its lower limit and 20° C. at its upper limit. By having the glass transition temperature in this range, the adhesive sheet can have better adhesion to various substrates.
  • the more preferable upper limit of the glass transition temperature is 10° C.
  • the tan ⁇ peak temperature derived from the above-mentioned viscoelasticity chart can be determined as the above-mentioned glass transition temperature.
  • the pressure-sensitive adhesive sheet of the present invention has a preferred lower limit of 6 N/cm in 180° peel adhesive strength to a SUS substrate at 25° C. after aging for one day in an environment of 25° C. and 50% RH.
  • the 180° peel adhesive strength to a SUS substrate at 25° C. is 6 N/cm or more
  • the resulting pressure-sensitive adhesive sheet can be suitably used for adhering electronic components and the like that require high adhesiveness.
  • a more preferred lower limit of the 180° peel adhesive strength to a SUS substrate at 25° C. is 8 N/cm.
  • the substantial upper limit is 25 N/cm.
  • the 180° peel adhesive strength to a SUS substrate at 25° C. can be measured, for example, by the following method. That is, first, the adhesive composition described later is coated on a release PET film, and then cured by simultaneously irradiating ultraviolet light having a wavelength of 365 nm and an illuminance of 20 mW/cm 2 and light having a wavelength of 405 nm and an illuminance of 40 mW/cm 2 so that the total irradiation amount is 900 mJ/cm 2 , to obtain a cured product (adhesive sheet) having a thickness of 100 ⁇ m.
  • the air surface of the cured product is sealed with an easy-adhesive polyester film, and cut to a predetermined size to prepare a laminated film.
  • the release PET film is peeled off from the laminated film, and the exposed surface is attached to a SUS substrate, and pressure-bonded by moving it back and forth with a 2 kg roller to obtain a test piece.
  • the 180 ° peel adhesive strength can be measured by performing 180 ° peel at a speed of 300 mm / min using a universal testing machine.
  • An example of the universal testing machine is Tensilon RTI-1310 (manufactured by A&D Co., Ltd.).
  • the pressure-sensitive adhesive sheet of the present invention is a cured product of a pressure-sensitive adhesive composition containing a photopolymerization initiator, that is, an ultraviolet-cured product obtained by curing the pressure-sensitive adhesive composition with ultraviolet light. Since the pressure-sensitive adhesive sheet of the present invention is an ultraviolet-cured product of the pressure-sensitive adhesive composition, it can be said that the pressure-sensitive adhesive sheet of the present invention is produced in a production process with little CO2 emission.
  • the pressure-sensitive adhesive composition preferably contains a nitrogen-containing compound.
  • the resulting pressure-sensitive adhesive sheet has excellent surface curing properties.
  • the nitrogen-containing compound examples include maleimide derivatives, nitrogen-containing vinyl compounds, etc. Among these, maleimide derivatives are preferred.
  • the reaction system of the maleimide derivative basically proceeds as a hydrogen abstraction (Type II) reaction. Photoradical polymerization by hydrogen abstraction reaction is not easily inhibited by oxygen, and can therefore increase the surface curability.
  • photoradical polymerization by hydrogen abstraction reaction does not produce a linear polymer as in cleavage (Type I) reaction, but produces a branched polymer, which also has high cohesive strength. Therefore, by containing the maleimide derivative, the pressure-sensitive adhesive composition can produce a pressure-sensitive adhesive sheet that is less susceptible to bleeding due to a decrease in surface curability and cohesive failure due to a decrease in surface curability and cohesive strength.
  • the above-mentioned "maleimide derivative” means a compound having a maleimide group.
  • examples of the monofunctional maleimide include N-cyclohexylmaleimide, N-laurylmaleimide, 4-hydroxyphenylmaleimide, N-(4-carboxycyclohexylmethyl)maleimide, N-phenylmaleimide, N-(2-methylphenyl)maleimide, N-(4-methylphenyl)maleimide, N-(2,6-diethylphenyl)maleimide, N-(2-chlorophenyl)maleimide, N-methylmaleimide, and N-ethylmaleimide.
  • Examples of the monofunctional maleimide include N-isopropylmaleimide, N-butylmaleimide, N-benzylmaleimide, N-phenylmethylmaleimide, N-(2,4,6-tribromophenyl)maleimide, N-[3-(triethoxysilyl)propyl]maleimide, N-octadecenylmaleimide, N-dodecenylmaleimide, N-(2-methoxyphenyl)maleimide, N-(2,4,6-trichlorophenyl)maleimide, and N-(1-hydroxyphenyl)maleimide.
  • the monofunctional maleimide is preferably at least one selected from the group consisting of N-cyclohexylmaleimide, 4-hydroxyphenylmaleimide, and N-(4-carboxycyclohexylmethyl)maleimide.
  • examples of polyfunctional maleimides include N,N'-methylene bismaleimide, N,N'-trimethylene bismaleimide, N,N'-dodecamethylene bismaleimide, N,N'-(4,4'-diphenylmethane) bismaleimide, 1,4-dimaleimidecyclohexane, isophorone bisurethane bis(N-ethylmaleimide), N,N'-P-phenylene bismaleimide, N,N'-m-phenylene bismaleimide, N,N'-m-toluylene bismaleimide, and N,N'-4,4'-biphenyl.
  • the above-mentioned monofunctional maleimide and these polyfunctional maleimides may be used in combination as the maleimide derivative.
  • the gel fraction becomes high, it is not preferable to use a large amount of the polyfunctional maleimide in combination.
  • an amide compound having a vinyl group is preferred, and a cyclic amide compound having a vinyl group is more preferred.
  • the cyclic amide compound having a vinyl group preferably has a lactam structure, and is more preferably a compound represented by the following formula (1):
  • n represents an integer from 2 to 6.
  • Examples of the compound represented by the above formula (1) include N-vinyl-2-pyrrolidone and N-vinyl- ⁇ -caprolactam. Of these, N-vinyl- ⁇ -caprolactam is preferred.
  • examples other than the above-mentioned cyclic amide compounds having a vinyl group include N-vinylacetamide, etc.
  • the preferred lower limit of the content of the nitrogen-containing compound in 100 parts by mass of the adhesive composition is 0.4 parts by mass, and the preferred upper limit is 15 parts by mass.
  • the resulting adhesive sheet has superior surface curing properties and adhesion to various substrates.
  • a more preferred lower limit of the content of the nitrogen-containing compound is 1.5 parts by mass, and a more preferred upper limit is 12 parts by mass.
  • the pressure-sensitive adhesive composition preferably contains a (meth)acrylic monomer.
  • a (meth)acrylic monomer By containing the (meth)acrylic monomer, the resulting pressure-sensitive adhesive composition has better curability.
  • (meth)acrylic means acrylic or methacrylic
  • (meth)acrylic monomer means a monomer having a (meth)acryloyl group
  • (meth)acryloyl means acryloyl or methacryloyl.
  • the (meth)acrylic monomer preferably contains a monofunctional (meth)acrylic monomer.
  • the term "monofunctional (meth)acrylic monomer” refers to a monomer having one (meth)acryloyl group in one molecule.
  • Examples of the monofunctional (meth)acrylic monomer include monofunctional (meth)acrylic acid ester compounds, monofunctional (meth)acrylamide compounds, etc.
  • Examples of the monofunctional (meth)acrylic acid ester compound include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, n-heptyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, isomyristyl (meth)acrylate, stearyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, and 2-hydroxybutyl (meth
  • Examples of the monofunctional (meth)acrylamide compounds include N,N-dimethyl(meth)acrylamide, N-(meth)acryloylmorpholine, N-hydroxyethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, and N,N-dimethylaminopropyl(meth)acrylamide.
  • the preferred lower limit of the content of the monofunctional (meth)acrylic monomer in 100 parts by mass of the adhesive composition is 15 parts by mass, and the preferred upper limit is 90 parts by mass.
  • the resulting adhesive composition has better curing properties, and the resulting adhesive sheet has better adhesion to various substrates.
  • a more preferred lower limit of the content of the monofunctional (meth)acrylic monomer is 20 parts by mass, and a more preferred upper limit is 60 parts by mass.
  • the (meth)acrylic monomer may contain a polyfunctional (meth)acrylic monomer.
  • the polyfunctional (meth)acrylic monomer serves as a cross-linking component.
  • polyfunctional (meth)acrylic monomer examples include polyfunctional urethane (meth)acrylates, polyfunctional (meth)acrylic acid ester compounds, and polyfunctional epoxy (meth)acrylates.
  • epoxy (meth)acrylate refers to a compound in which all epoxy groups in an epoxy compound have been reacted with (meth)acrylic acid.
  • the above-mentioned polyfunctional urethane (meth)acrylate can be obtained, for example, by reacting a (meth)acrylic acid derivative having a hydroxyl group with an isocyanate compound in the presence of a catalytic amount of a tin-based compound.
  • MDI diphenylmethane-4,4'-
  • isocyanate compound serving as a raw material for the polyfunctional urethane (meth)acrylate a chain-extended isocyanate compound obtained by reacting a polyol with an excess of an isocyanate compound can also be used.
  • the polyol include ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, and polycaprolactone diol.
  • Examples of the (meth)acrylic acid derivative having a hydroxyl group include hydroxyalkyl mono(meth)acrylates, mono(meth)acrylates of dihydric alcohols, and mono(meth)acrylates or di(meth)acrylates of trihydric alcohols.
  • Examples of the hydroxyalkyl mono(meth)acrylate include 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, and 4-hydroxybutyl(meth)acrylate.
  • Examples of the dihydric alcohol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol.
  • Examples of the trihydric alcohol include trimethylolethane, trimethylolpropane, and glycerin.
  • polyfunctional (meth)acrylic acid ester compounds examples include 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide-added
  • polyfunctional epoxy (meth)acrylate examples include bisphenol A type epoxy (meth)acrylate, bisphenol F type epoxy (meth)acrylate, bisphenol E type epoxy (meth)acrylate, and caprolactone modified versions of these.
  • the preferred lower limit of the content of the polyfunctional (meth)acrylic monomer in 100 parts by mass of the pressure-sensitive adhesive composition is 0.5 parts by mass, and the preferred upper limit is 10 parts by mass.
  • the resulting pressure-sensitive adhesive composition has superior cohesive strength, and the resulting pressure-sensitive adhesive sheet has superior adhesion to various substrates.
  • a more preferred lower limit of the content of the polyfunctional (meth)acrylic monomer is 1.5 parts by mass, and a more preferred upper limit is 6 parts by mass.
  • the (meth)acrylic monomer preferably contains a monomer capable of acting as a hydrogen donor.
  • the monomer capable of serving as a hydrogen donor is preferably a monomer having at least one structure selected from the group consisting of an ether bond, an acetyl group, a phenoxy group, a benzyl group, and an amide bond.
  • the monomer capable of serving as a hydrogen donor is preferably a monomer having at least one structure selected from the group consisting of an ether bond, an acetyl group, a phenoxy group, a benzyl group, and an amide bond, so that the monomer can more easily provide hydrogen to a hydrogen abstraction reaction.
  • the monomer capable of serving as a hydrogen donor is more preferably a monomer having at least one structure selected from the group consisting of an ether bond, a phenoxy group, and an amide bond.
  • the (meth)acrylic monomer preferably contains 50% by mass or more of a monomer having at least one structure selected from the group consisting of an ether bond, an acetyl group, a phenoxy group, a benzyl group, and an amide bond.
  • the (meth)acrylic monomer contains 50% by mass or more of a monomer having at least one structure selected from the group consisting of an ether bond, an acetyl group, a phenoxy group, a benzyl group, and an amide bond, so that the resulting pressure-sensitive adhesive composition has better surface curing properties.
  • the (meth)acrylic monomer more preferably contains 70% by mass or more of a monomer having at least one structure selected from the group consisting of an ether bond, an acetyl group, a phenoxy group, a benzyl group, and an amide bond.
  • the (meth)acrylic monomer may contain only a monomer having at least one structure selected from the group consisting of an ether bond, an acetyl group, a phenoxy group, a benzyl group, and an amide bond.
  • the pressure-sensitive adhesive composition contains a photopolymerization initiator.
  • the photopolymerization initiator preferably includes at least one selected from the group consisting of hydrogen abstraction type photopolymerization initiators and polymer type photopolymerization initiators.
  • the resulting pressure-sensitive adhesive sheet is less susceptible to bleeding due to a decrease in surface curability and cohesive failure due to a decrease in surface curability and cohesive strength.
  • the hydrogen abstraction type photopolymerization initiator is preferably a benzophenone-based photopolymerization initiator.
  • benzophenone-based photopolymerization initiator examples include benzophenone, 4-chlorobenzophenone, 4,4'-dimethylbenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, o-benzoyl methyl benzoate, 3,3'-dimethyl-4-methoxybenzophenone, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 4-morpholinobenzophenone, 4,4'-diphenoxybenzophenone, 4-hydroxybenzophenone, 2-carboxybenzophenone, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methyl-propionyl)-benzyl)-phenyl)-2-methyl-propan-1-one, 1-(4-(4-benzoylphenylthio)phenyl)-2-tos
  • polymeric photopolymerization initiator examples include polymers of ethyl (2,4,6-trimethylbenzoyl)-phenyl phosphonate, polyethylene glycol di( ⁇ -4(4-(2-dimethylamino-2-benzyl)butanoylphenyl)piperazine)propionate, and bis(benzophenone-2-carboxylic acid) polyethylene glycol ester.
  • Omnipol TP Omnipol 910
  • Omnipol 2702 All manufactured by IGM Resins.
  • cleavage type photopolymerization initiator As the photopolymerization initiator, a cleavage type photopolymerization initiator can also be used.
  • the cleavage type photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.
  • the preferred lower limit of the content of the photopolymerization initiator in 100 parts by mass of the pressure-sensitive adhesive composition is 1 part by mass, and the preferred upper limit is 15 parts by mass.
  • the resulting pressure-sensitive adhesive composition has better storage stability and curing properties, and the resulting pressure-sensitive adhesive sheet has better adhesion to various substrates.
  • a more preferred lower limit of the content of the photopolymerization initiator is 3 parts by mass, and a more preferred upper limit is 8 parts by mass.
  • the pressure-sensitive adhesive composition preferably contains an amine compound.
  • an amine compound As described above, by using the amine compound in combination with at least one selected from the group consisting of the hydrogen abstraction type photopolymerization initiator and the polymer type photopolymerization initiator, the resulting pressure-sensitive adhesive sheet is less susceptible to bleeding due to reduced surface curability and cohesive failure due to reduced surface curability and cohesive strength.
  • amine compounds examples include (bis-N,N-(4-dimethylaminobenzoyl)oxyethylene-1-yl)-methylamine, bis(2-morpholinoethyl)ether, 1-methyl 10-(1,2,2,6,6-pentamethyl-4-piperidinyl) decanedioate, tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate, and bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate.
  • the preferred lower limit of the content of the amine compound in 100 parts by mass of the adhesive composition is 0.5 parts by mass, and the preferred upper limit is 5 parts by mass.
  • the resulting adhesive composition has better surface curing properties.
  • the content of the amine compound is 5 parts by mass or less, the resulting adhesive sheet is less likely to cause cohesive failure.
  • a more preferred lower limit of the content of the amine compound is 1.5 parts by mass, and a more preferred upper limit is 3 parts by mass.
  • the pressure-sensitive adhesive composition preferably contains a thermoplastic resin.
  • the thermoplastic resin is preferably a compound that does not contain a reactive double bond, or a compound that has a reactive double bond but does not substantially exhibit photoradical polymerization reactivity.
  • thermoplastic resin examples include a solvent-free acrylic polymer and a polymer obtained by drying a polymer dissolved in a solvent.
  • solvent-free acrylic polymer examples include a polymer of at least one monomer selected from (meth)acrylic acid alkyl esters having an alkyl group with 1 to 20 carbon atoms, and a copolymer of the monomer and another copolymerizable monomer.
  • commercially available ones include, for example, the ARUFON-UP1000 series, UH2000 series, UC3000 series (all manufactured by Toagosei Co., Ltd.), the Clarity LA series, and the Clarity LK series (all manufactured by Kuraray Co., Ltd.).
  • the preferred lower limit of the content of the thermoplastic resin in 100 parts by mass of the pressure-sensitive adhesive composition is 5 parts by mass, and the preferred upper limit is 45 parts by mass.
  • the content of the thermoplastic resin is within this range, the viscosity of the resulting pressure-sensitive adhesive composition is improved, a thick coating film can be formed, the printability is superior, and the decrease in adhesion at high temperatures can be suppressed.
  • a more preferred lower limit of the content of the thermoplastic resin is 10 parts by mass, and a more preferred upper limit is 25 parts by mass.
  • the adhesive composition may contain a thermosetting resin or a moisture-curing resin, and thus may exhibit reactivity to triggers such as heat and moisture.
  • thermosetting resin examples include epoxy resin, phenol resin, urea resin, melamine resin, etc.
  • epoxy resin is preferable.
  • the epoxy resin include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, phenol novolac type epoxy resins, biphenyl type epoxy resins, biphenyl novolac type epoxy resins, biphenol type epoxy resins, naphthalene type epoxy resins, fluorene type epoxy resins, phenol aralkyl type epoxy resins, naphthol aralkyl type epoxy resins, dicyclopentadiene type epoxy resins, anthracene type epoxy resins, epoxy resins having an adamantane skeleton, epoxy resins having a tricyclodecane skeleton, and epoxy resins having a triazine nucleus in the skeleton.
  • thermosetting agent is contained in the pressure-sensitive adhesive composition.
  • the heat curing agent include cyanate ester compounds (cyanate ester curing agents), phenol compounds (phenol heat curing agents), amine compounds (amine heat curing agents), thiol compounds (thiol heat curing agents), imidazole compounds, phosphine compounds, acid anhydrides, active ester compounds, and dicyandiamide.
  • a photocationic polymerization initiator may be contained in the adhesive composition. This allows the curing to proceed gradually even after the first stage of irradiation with active energy rays. As a result, the resulting adhesive sheet has even better initial adhesive strength.
  • the photocationic polymerization initiator is not particularly limited as long as it generates a protonic acid or a Lewis acid upon irradiation with light, and may be an ionic photoacid generating type or a non-ionic photoacid generating type.
  • Examples of the ionic photoacid generating type photocationic polymerization initiator include the following: onium salts in which the cationic moiety is an aromatic sulfonium, aromatic iodonium, aromatic diazonium, aromatic ammonium, or (2,4-cyclopentadiene-1-yl)((1-methylethyl)benzene)-Fe cation and the anionic moiety is BF 4 - , PF 6 - , SbF 6 - , or (BX 4 ) - , where X represents a phenyl group substituted with at least two or more fluorine or trifluoromethyl groups.
  • aromatic sulfonium salts include, for example, bis(4-(diphenylsulfonio)phenyl)sulfide bishexafluorophosphate, bis(4-(diphenylsulfonio)phenyl)sulfide bishexafluoroantimonate, bis(4-(diphenylsulfonio)phenyl)sulfide bistetrafluoroborate, bis(4-(diphenylsulfonio)phenyl)sulfide tetrakis(pentafluorophenyl)borate, diphenyl-4-(phenylthio)phenylsulfonium hexafluorophosphate, diphenyl-4-(phenylthio)phenylsulfonium hexafluoroantimonate, diphenyl-4-(phenylthio)phenylsulfonium tetrafluoroborate, and
  • triphenylsulfonium hexafluorophosphate triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis(pentafluorophenyl)borate, bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl)sulfide bishexafluorophosphate, bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl)sulfide bishexafluoroantimonate, bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl)sulfide bistetrafluoroborate, bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyls
  • aromatic diazonium salt examples include phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, phenyldiazonium tetrafluoroborate, and phenyldiazonium tetrakis(pentafluorophenyl)borate.
  • aromatic ammonium salts examples include 1-benzyl-2-cyanopyridinium hexafluorophosphate, 1-benzyl-2-cyanopyridinium hexafluoroantimonate, 1-benzyl-2-cyanopyridinium tetrafluoroborate, 1-benzyl-2-cyanopyridinium tetrakis(pentafluorophenyl)borate, 1-(naphthylmethyl)-2-cyanopyridinium hexafluorophosphate, 1-(naphthylmethyl)-2-cyanopyridinium hexafluoroantimonate, 1-(naphthylmethyl)-2-cyanopyridinium tetrafluoroborate, and 1-(naphthylmethyl)-2-cyanopyridinium tetrakis(pentafluorophenyl)borate.
  • Examples of the (2,4-cyclopentadiene-1-yl)((1-methylethyl)benzene)-Fe salt include (2,4-cyclopentadiene-1-yl)((1-methylethyl)benzene)-Fe(II) hexafluorophosphate, (2,4-cyclopentadiene-1-yl)((1-methylethyl)benzene)-Fe(II) hexafluoroantimonate, (2,4-cyclopentadiene-1-yl)((1-methylethyl)benzene)-Fe(II) tetrafluoroborate, and (2,4-cyclopentadiene-1-yl)((1-methylethyl)benzene)-Fe(II) tetrakis(pentafluorophenyl)borate.
  • nonionic photoacid generating cationic photopolymerization initiator examples include nitrobenzyl esters, sulfonic acid derivatives, phosphate esters, phenolsulfonic acid esters, diazonaphthoquinones, and N-hydroxyimidesulfonates.
  • the above cationic photopolymerization initiators may be used alone or in combination of two or more kinds.
  • the content of the photocationic polymerization initiator is preferably such that the lower limit is 0.1 parts by mass and the upper limit is 10 parts by mass relative to 100 parts by mass of the epoxy resin.
  • the moisture-curing resin examples include moisture-curing urethane resin and resin having a crosslinkable silyl group. Among them, moisture-curing urethane resin is preferable. Moisture-curing urethane resin has a urethane bond and an isocyanate group, and the isocyanate group in the molecule reacts with moisture to cure. It is preferable that the isocyanate group is at the end of the molecule.
  • the moisture-curable urethane resin may have a radical reactive functional group.
  • the moisture-curable urethane resin can be obtained by reacting a polyol compound having two or more hydroxyl groups in one molecule with a polyisocyanate compound having two or more isocyanate groups in one molecule.
  • the moisture-curable resin When the moisture-curable resin is used, it is preferable to add a moisture-curing accelerator to the pressure-sensitive adhesive composition from the viewpoint of improving the curing speed during moisture curing.
  • the moisture curing accelerator include a compound having a morpholine skeleton, a compound having a piperidine skeleton, and a compound having a piperazine skeleton.
  • the pressure-sensitive adhesive composition preferably contains a tackifier.
  • tackifier include rosin-based resins and terpene-based resins.
  • the rosin-based resin includes, for example, rosin diol.
  • the rosin diol is not particularly limited as long as it is a rosin-modified diol having two rosin skeletons and two hydroxyl groups in the molecule.
  • Diols having a rosin component in the molecule are called rosin polyols, and these include polyether types such as polypropylene glycol (PPG) in which the skeleton excluding the rosin component is polyether, and polyester types such as condensation polyester polyols, lactone polyester polyols, and polycarbonate diols.
  • PPG polypropylene glycol
  • polyester types such as condensation polyester polyols, lactone polyester polyols, and polycarbonate diols.
  • rosin diol examples include rosin ester obtained by reacting rosin with a polyhydric alcohol, epoxy-modified rosin ester obtained by reacting rosin with an epoxy compound, and modified rosin having a hydroxyl group, such as polyether having a rosin skeleton, etc. These can be produced by conventionally known methods.
  • the rosin component includes, for example, abietic acid and its derivatives, such as pimaric acid type resin acids as dehydroabietic acid, dihydroabietic acid, tetrahydroabietic acid, diabietic acid, neoabietic acid, and levopimaric acid, hydrogenated rosins obtained by hydrogenating these, and disproportionated rosins obtained by disproportionating these.
  • abietic acid and its derivatives such as pimaric acid type resin acids as dehydroabietic acid, dihydroabietic acid, tetrahydroabietic acid, diabietic acid, neoabietic acid, and levopimaric acid, hydrogenated rosins obtained by hydrogenating these, and disproportionated rosins obtained by disproportionating these.
  • rosin-based resins include Pine Crystal D-6011, Pine Crystal KE-615-3, Pine Crystal KR-614, Pine Crystal KE-100, Pine Crystal KE-311, Pine Crystal KE-359, Pine Crystal KE-604, and Pine Crystal D-6250 (all manufactured by Arakawa Chemical Industries Co., Ltd.).
  • the terpene resin examples include terpene phenol resins.
  • the terpene phenol resin is a copolymer of phenol and a terpene resin, which is an essential oil component obtained from natural products such as rosin and orange peel, and also includes partially hydrogenated terpene phenol resins in which at least a portion of the copolymer is hydrogenated, and fully hydrogenated terpene phenol resins in which the copolymer is completely hydrogenated.
  • the fully hydrogenated terpene phenolic resin is a terpene resin obtained by substantially completely hydrogenating a terpene phenolic resin
  • the partially hydrogenated terpene phenolic resin is a terpene resin obtained by partially hydrogenating a terpene phenolic resin.
  • the terpene phenolic resin has a double bond derived from a terpene and an aromatic ring double bond derived from a phenol. Therefore, the fully hydrogenated terpene phenolic resin means a resin in which both the terpene portion and the phenol portion are completely or almost hydrogenated, and the partially hydrogenated terpene phenolic resin means a resin in which the degree of hydrogenation of these portions is not complete but partial.
  • the hydrogenation method and reaction form are not particularly limited.
  • examples of commercially available ones include YS Polystar NH (fully hydrogenated terpene phenol-based resin) manufactured by Yasuhara Chemical Co., Ltd.
  • the preferred lower limit of the content of the tackifier in 100 parts by mass of the adhesive composition is 5 parts by mass, and the preferred upper limit is 50 parts by mass.
  • the resulting adhesive sheet has better adhesion to various substrates.
  • a more preferred lower limit of the content of the tackifier is 15 parts by mass, and a more preferred upper limit is 35 parts by mass.
  • the pressure-sensitive adhesive composition may contain a plasticizer.
  • the plasticizer include organic acid esters, organic phosphates, and organic phosphites.
  • Examples of the organic acid ester include monobasic organic acid esters and polybasic organic acid esters.
  • Examples of the monobasic organic acid ester include glycol esters obtained by reacting a monobasic organic acid such as butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptyl acid, n-octylic acid, 2-ethylhexyl acid, pelargonic acid (n-nonylic acid), or decylic acid with a glycol such as triethylene glycol, tetraethylene glycol, or tripropylene glycol.
  • a monobasic organic acid such as butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptyl acid, n-octylic acid, 2-ethylhexyl acid, pelargonic acid (n-nonylic acid), or decylic acid with a glycol such as triethylene glycol
  • polybasic organic acid ester examples include ester compounds obtained by reacting a polybasic organic acid such as adipic acid, sebacic acid, or azelaic acid with an alcohol having a linear or branched structure having 4 to 8 carbon atoms.
  • organic acid esters include triethylene glycol di-2-ethylbutyrate (3GH), triethylene glycol di-2-ethylhexanoate (3GO), triethylene glycol dicaprylate, triethylene glycol di-n-octanoate, and triethylene glycol di-n-heptanoate (3G7).
  • tetraethylene glycol di-n-heptanoate (4G7) tetraethylene glycol di-2-ethylhexanoate, dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate, ethylene glycol di-2-ethylbutyrate, and 1,3-propylene glycol di-2-ethylbutyrate.
  • 1,4-butylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylhexanoate, and dipropylene glycol di-2-ethylbutyrate are also included.
  • Examples include triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate (4GH), diethylene glycol dicapryate, dihexyl adipate (DHA), dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, etc.
  • Other examples include oil-modified sebacic acid alkyd, a mixture of a phosphate ester and an adipate ester, and a mixed adipate ester made from an alkyl alcohol having 4 to 9 carbon atoms and a cyclic alcohol having 4 to 9 carbon atoms.
  • the organic phosphate or organic phosphite may be a compound obtained by a condensation reaction between phosphoric acid or phosphorous acid and an alcohol.
  • a compound obtained by a condensation reaction between an alcohol having 1 to 12 carbon atoms and phosphoric acid or phosphorous acid is preferable.
  • the alcohol having 1 to 12 carbon atoms include methanol, ethanol, butanol, hexanol, 2-ethylbutanol, heptanol, octanol, 2-ethylhexanol, decanol, dodecanol, butoxyethanol, butoxyethoxyethanol, and benzyl alcohol.
  • organic phosphate ester or organic phosphite ester examples include trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tri(2-ethylhexyl) phosphate, tri(butoxyethyl) phosphate, tri(2-ethylhexyl) phosphite, isodecylphenyl phosphate, and triisopropyl phosphate.
  • the pressure-sensitive adhesive composition may contain a defoaming agent.
  • the defoaming agent include silicone-based defoaming agents, acrylic polymer-based defoaming agents, vinyl ether polymer-based defoaming agents, and olefin polymer-based defoaming agents.
  • the pressure-sensitive adhesive composition may further contain various known additives such as a crosslinking agent, a viscosity modifier, a silane coupling agent, a sensitizer, a heat curing agent, a cure retarder, an antioxidant, a storage stabilizer, a dispersant, and a filler, within the scope of not impairing the object of the present invention.
  • various known additives such as a crosslinking agent, a viscosity modifier, a silane coupling agent, a sensitizer, a heat curing agent, a cure retarder, an antioxidant, a storage stabilizer, a dispersant, and a filler, within the scope of not impairing the object of the present invention.
  • the pressure-sensitive adhesive composition is substantially free of organic solvents, and specifically, it is preferable that the content of the organic solvent per 100 mass of the pressure-sensitive adhesive composition is 1.5 parts by mass or less.
  • the method for preparing the pressure-sensitive adhesive composition includes, for example, a method in which the nitrogen-containing compound, the (meth)acrylic monomer, the photopolymerization initiator, the thermoplastic resin, and additives added as necessary are mixed using a mixer.
  • the mixer include a homodisper, a homomixer, a universal mixer, a planetary mixer, a kneader, and a three-roll mixer.
  • the pressure-sensitive adhesive composition has a viscosity at 25° C. of preferably 5 mPa ⁇ s at the lower limit and 250,000 mPa ⁇ s at the upper limit. By setting the viscosity within this range, the pressure-sensitive adhesive composition is more suitable for printing.
  • the more preferred lower limit of the viscosity is 100 mPa ⁇ s, and the more preferred upper limit is 150,000 mPa ⁇ s.
  • the viscosity can be measured, for example, using a VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) as an E-type viscometer and using an appropriate cone plate depending on the viscosity range of the pressure-sensitive adhesive composition, under conditions of 25° C. and 10 rpm.
  • the adhesive sheet of the present invention is formed by irradiating the adhesive composition with ultraviolet light to cure it.
  • the adhesive sheet of the present invention may be formed on a substrate (separator) and transferable to an adherend, or may be formed directly on an adherend.
  • the adhesive sheet of the present invention is formed directly on an adherend, the number of times of lamination can be minimized and air bubbles can be prevented from being introduced at the interface during lamination.
  • the adhesive sheet of the present invention is formed on a substrate (separator), the adhesive sheet is placed on the adherend by transfer, which has the advantage of fewer constraints on application.
  • the thickness of the adhesive sheet of the present invention is preferably 30 ⁇ m or more, and more preferably 50 ⁇ m or more. By having a thickness of the adhesive layer of 30 ⁇ m or more, sufficient adhesion can be obtained. Furthermore, from the viewpoint of responding to the trend toward thinner electronic devices, the thickness of the adhesive layer is preferably 1000 ⁇ m or less, and more preferably 500 ⁇ m or less.
  • the method includes a step of forming the adhesive sheet of the present invention by applying the adhesive composition to a first adherend or a separator and exposing the composition to light, and a step of attaching a second adherend to the adhesive layer, and the method of applying the adhesive composition is inkjet printing, screen printing, spray coating, spin coating, gravure offset, or reverse offset printing.
  • the present invention also includes a method of manufacturing a laminate in which the adhesive composition is partially applied to the first adherend. When the adhesive sheet of the present invention is formed on the separator, a step of transferring the obtained adhesive sheet to the first adherend is performed, and then a step of attaching a second adherend to the adhesive layer is performed.
  • Examples of the material for the first adherend and the second adherend include metals such as stainless steel and aluminum, resins, etc.
  • an adhesive sheet that is obtained by UV curing and has excellent impact resistance.
  • a method for producing a laminate having the adhesive sheet it is possible to provide a laminate having the adhesive sheet.
  • FIG. 1 is a schematic diagram showing the relationship between Ggtemp, GF1temp, GF2temp, and GF2tan ⁇ in a viscoelasticity chart.
  • Adhesive Sheets (Examples 1 to 4, 6, 7, 9 to 18, Comparative Example 2)
  • the obtained adhesive composition was applied to the inner treated surface of a release PET film (manufactured by Nippa Corporation, "1-C", thickness 38 ⁇ m) with an applicator to a thickness of 100 ⁇ m.
  • a crosslinking agent was mixed into the adhesive composition before application so as to have the content shown in Tables 1 to 3.
  • the adhesive composition was cured by simultaneously irradiating ultraviolet light having a wavelength of 365 nm and an illuminance of 20 mW/cm 2 and light having a wavelength of 405 nm and an illuminance of 40 mW/cm 2 in an atmospheric environment without sealing the coated surface, using a batch-type UV LED curing device, so that the total irradiation amount was 900 mJ/cm 2.
  • a batch-type UV LED curing device M UVBA (manufactured by ITEC Co., Ltd.) was used.
  • the air side of the pressure-sensitive adhesive sheet was sealed with a PET sheet (Nippa Corporation "1-E", thickness 50 ⁇ m) that had been release-treated on one side, to obtain a laminate including the pressure-sensitive adhesive sheet.
  • a PET sheet Nippa Corporation "1-E", thickness 50 ⁇ m
  • the pressure-sensitive adhesive sheet obtained by this method is formed by only irradiating the pressure-sensitive adhesive composition with ultraviolet light without heating it, it can be said to have an excellent effect of reducing CO2 emissions.
  • the pressure-sensitive adhesive sheet obtained without using the acrylic polymers A and B produced by heating can be said to have an excellent effect of reducing CO2 emissions.
  • Examples 5 and 8, Comparative Example 1 The obtained adhesive composition was applied to the inner treated surface of a release PET film (manufactured by Nippa Corporation, "1-C", thickness 38 ⁇ m) with an applicator to a thickness of 100 ⁇ m.
  • a crosslinking agent was mixed into the adhesive composition before application to the contents shown in Tables 1 and 3.
  • the air surface was sealed with a release PET film (manufactured by Nippa Corporation, "1-E", thickness 50 ⁇ m).
  • a batch-type UV LED curing device was used to simultaneously irradiate ultraviolet light with a wavelength of 365 nm and an illuminance of 4 mW/cm 2 and light with a wavelength of 405 nm and an illuminance of 4 mW/cm 2 to a total irradiation amount of 1500 mJ/cm 2 , thereby curing the adhesive composition and obtaining a laminate including an adhesive sheet.
  • the pressure-sensitive adhesive sheet obtained by this method is also formed by only irradiating the pressure-sensitive adhesive composition with ultraviolet light without heating it, and therefore can be said to have an excellent effect of reducing CO2 emissions.
  • the pressure-sensitive adhesive sheet obtained without using the acrylic polymers A and B produced by heating can be said to have an excellent effect of reducing CO2 emissions.
  • the time when the dropping started was defined as the polymerization initiation time, and a polymer solution was obtained by carrying out a polymerization reaction at 60°C for 6 hours from the start of polymerization.
  • the crosslinking agent was mixed into the obtained polymer solution in an amount shown in Table 3, and then the mixture was applied using an applicator onto a release PET film (manufactured by Nippa Corporation, "1-C", thickness 38 ⁇ m) so that the thickness after drying would be 100 ⁇ m, to obtain an adhesive sheet. Drying was performed in the order of 20 minutes at 40° C., 20 minutes at 60° C., and 10 minutes at 110° C.
  • the air side of the adhesive sheet was sealed with a PET sheet (manufactured by Nippa Corporation, "1-E", thickness 50 ⁇ m) that had been release-treated on one side, to obtain a laminate including the adhesive sheet.
  • a PET sheet manufactured by Nippa Corporation, "1-E", thickness 50 ⁇ m
  • the pressure-sensitive adhesive sheet obtained by this method is formed by heating the pressure-sensitive adhesive composition, and therefore is inferior in terms of the effect of reducing CO2 emissions.
  • Shear method Measured with twin drive using 8 mm parallel plate Measurement temperature: -70°C to 200°C Heating rate: 7°C/min Frequency: 1Hz While cooling from 50°C to -70°C at 10°C/min, pre-pressure is applied at 8N, and measurements are taken from the low temperature as described below in (3-1) to (3-6). (3-1) The temperature is raised with a normal force of 20 N and a strain of 0.005%, and measurements are taken under these conditions until the torque value becomes less than 1500 ⁇ N ⁇ m. (3-2) After (3-1), the temperature is increased with a normal force of 8 N and a strain of 0.05%, and measurements are taken under these conditions until the torque value becomes less than 200 ⁇ N ⁇ m.
  • the laminate including the obtained pressure-sensitive adhesive sheet was cut to a width of 75 mm and a length of 125 mm, and then one of the release PET films was peeled off and transferred to the inner treated surface of an easily adhesive polyester film (manufactured by Toyobo Co., Ltd., "Cosmoshine A4100"), and cut to a width of 25 mm and a length of 200 mm (adhering surface 25 mm x 125 mm) to obtain a laminated film.
  • an easily adhesive polyester film manufactured by Toyobo Co., Ltd., "Cosmoshine A4100
  • the other release PET film was peeled off from the laminated film, and the exposed surface was attached to a SUS 304-BA substrate having a width of 80 mm, a length of 125 mm, and a thickness of 1 mm, and pressure-bonded by moving it back and forth once with a 2 kg roller to obtain a test piece.
  • the obtained test piece was aged for one day in an environment of 25°C and 50% RH, and then 180° peel adhesion was measured by performing 180° peel at a speed of 300 mm/min using a universal testing machine (manufactured by A&D Co., Ltd., "Tensilon RTI-1310").
  • the laminate including the obtained adhesive sheet was cut into 25 mm x 25 mm, and both release PET films were peeled off. Next, a SUS substrate of 40 mm x 40 mm x 3 mmt with a hole of 20 mm x 20 mm x 3 mmt in the center and a SUS substrate of 25 mm x 25 mm x 3 mmt were bonded together through the adhesive sheet to obtain a laminate.
  • the obtained laminate was pressed at 62 N using a universal testing machine (manufactured by A & D Co., Ltd., "Tensilon RTI-1310") to prepare a test piece.
  • a drop weight impact tester manufactured by IMATEK Co., Ltd., "IM1C-15 type"
  • a drop weight of 16 ⁇ and a total mass of 5 kg was dropped naturally from a height of 51 mm to impact the center of the test piece.
  • the area (amount of energy) of the first peak was calculated as the impact absorption rate ⁇ E (J).
  • the maximum point was taken as the peak force (impact resistance test force (N)).
  • the impact resistance was evaluated according to the following criteria.
  • ⁇ E When ⁇ E exceeds 0.345 J or when the peak force exceeds 1.60 N ⁇ : When ⁇ E is 0.120 J or more and 0.345 J or less and the peak force is 1.20 N or more and 1.60 N or less ⁇ : When ⁇ E is less than 0.120 J and the peak force is 1.20 N or more and 1.60 N or less, or when ⁇ E is 0.120 J or more and 0.345 J or less and the peak force is less than 1.20 N XX: When ⁇ E is less than 0.120 J and the peak force is less than 1.20 N
  • an adhesive sheet that is obtained by UV curing and has excellent impact resistance.
  • a method for producing a laminate having the adhesive sheet it is possible to provide a laminate having the adhesive sheet.

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Abstract

A purpose of the present invention is to provide a pressure-sensitive adhesive sheet which has excellent impact resistance although being obtained by ultraviolet curing. Another purpose of the present invention is to provide a method for producing a laminate including the pressure-sensitive adhesive sheet. This pressure-sensitive adhesive sheet is a cured object obtained from a pressure-sensitive adhesive composition containing a photopolymerization initiator. The pressure-sensitive adhesive sheet, when examined for dynamic viscoelasticity by a shear method under the conditions of measurement temperatures of from -70°C to 200°C and a frequency of 1 Hz, gives a viscoelasticity chart in which in cases when a lowest temperature at which the loss modulus is maximal is expressed by Ggtemp and a temperature that is the lowest among the temperatures at which the tanδ is maximal and which are higher than the Ggtemp is expressed by Tg and when a temperature that is the lowest among the temperatures at which the ratio between the storage modulus and the loss modulus is minimum and which are in a temperature range of from Tg to 50°C is expressed by GF1temp, a temperature that is the lowest among the temperatures at which the loss tangent is minimal in a range of temperatures higher than the GF1temp is expressed by GF2temp, and the loss tangent at the GF2temp is expressed by GF2tanδ, then the temperature difference between the Ggtemp and the GF1temp is 25.0°C or greater and the GF2tanδ is 0.34 or greater.

Description

粘着シート、及び、積層体の製造方法Method for manufacturing pressure-sensitive adhesive sheet and laminate
本発明は、粘着シートに関する。また、本発明は、該粘着シートを有する積層体の製造方法に関する。 The present invention relates to an adhesive sheet. The present invention also relates to a method for producing a laminate having the adhesive sheet.
スマートフォン、ＰＣ等の電子機器の内部で電子部品の貼り合わせに粘着剤が用いられている。粘着剤による貼り合わせの一般的な方法では、まず、粘着剤の両面にそれぞれセパレータが配置された粘着シートが作製され、次に、粘着シートを所望の形状に裁断する。その後、裁断された粘着シートから一方のセパレータを剥離して、露出した粘着剤の一方の面と第一の被着体との貼り合わせが行われ、続いて、他方のセパレータを剥離して、露出した粘着剤の他方の面と第二の被着体との貼り合わせが行われる。この方法の場合、裁断後に粘着シートの一部が廃棄されることから、廃棄物が発生していた。また、貼り合わせ面に気泡が入ることがあった。 Adhesives are used to bond electronic components inside electronic devices such as smartphones and PCs. In a typical method of bonding using adhesives, an adhesive sheet is first prepared with separators on both sides of the adhesive, and then the adhesive sheet is cut into the desired shape. One separator is then peeled off from the cut adhesive sheet, and one side of the exposed adhesive is bonded to a first adherend, and then the other separator is peeled off, and the other side of the exposed adhesive is bonded to a second adherend. With this method, part of the adhesive sheet is discarded after cutting, generating waste. Also, air bubbles can sometimes get into the bonded surfaces.
これに対して、粘着シートを作製することなく、粘着剤組成物を所望の形状に印刷してから被着体との貼り合わせを行う方法が検討されている。この方法によれば、廃棄物の発生を抑制し、貼り合わせ面に気泡が入ることも防止できる。 In response to this, a method has been developed in which a pressure-sensitive adhesive composition is printed in a desired shape and then bonded to an adherend, without the need to prepare a pressure-sensitive adhesive sheet. This method can reduce waste generation and prevent air bubbles from forming on the bonding surface.
例えば、特許文献１には、放射線硬化型の粘着剤組成物で、微細なパターニングが可能であるとともに、金属やプラスチック等の種々の被着体に対する高い接着性を発揮する組成物を提供するための発明が開示されている。該特許文献１には、芳香環非含有エチレン性不飽和モノマー１０～７０重量％、光重合開始剤１～１０重量％、及び架橋剤１０～５５重量％、を含有する放射線硬化性粘着組成物が記載されている。 For example, Patent Document 1 discloses an invention for providing a radiation-curable adhesive composition that allows fine patterning and exhibits high adhesion to various adherends such as metals and plastics. Patent Document 1 describes a radiation-curable adhesive composition that contains 10 to 70% by weight of an ethylenically unsaturated monomer that does not contain an aromatic ring, 1 to 10% by weight of a photopolymerization initiator, and 10 to 55% by weight of a crosslinking agent.
また、特許文献２には、酸素存在下で光照射した場合でも、酸素が存在しない場合と同等な接着強度を有する積層体を与える、光硬化型接着組成物を提供するための発明が開示されている。該特許文献２には、（Ａ）（メタ）アクリレートオリゴマー、（Ｂ）単官能の（メタ）アクリルモノマー、（Ｃ）２～４官能の（メタ）アクリルモノマー、（Ｄ）光反応開始剤、（Ｅ）軟化点が７０～１５０℃の粘着付与剤、及び（Ｆ）液状可塑剤を含む、光硬化型接着組成物が記載されている。 Patent Document 2 discloses an invention for providing a photocurable adhesive composition that, even when irradiated with light in the presence of oxygen, gives a laminate having adhesive strength equivalent to that in the absence of oxygen. Patent Document 2 describes a photocurable adhesive composition that contains (A) a (meth)acrylate oligomer, (B) a monofunctional (meth)acrylic monomer, (C) a di- to tetrafunctional (meth)acrylic monomer, (D) a photoinitiator, (E) a tackifier having a softening point of 70 to 150°C, and (F) a liquid plasticizer.
特開２０１３－２１６７４２号公報JP 2013-216742 A 国際公開第２０１６／１６３１５２号International Publication No. 2016/163152
上記したように、予め粘着シートを作製することなく、粘着剤組成物を所望の形状に印刷してから粘着シートを形成して被着体との貼り合わせを行う方法によれば、廃棄物の発生を抑制し、貼り合わせ面に気泡が入ることも防止できる。一方で、粘着剤組成物を硬化する方法としては、被着体の加熱を避ける観点やＣＯ２排出量を削減する観点から紫外線硬化が望ましいが、紫外線硬化により得られる粘着シートは、耐衝撃性に劣るという問題があった。 As described above, the method of printing the adhesive composition in a desired shape, forming an adhesive sheet, and laminating it to an adherend without preparing an adhesive sheet in advance can suppress the generation of waste and prevent air bubbles from being introduced into the lamination surface. On the other hand, as a method for curing the adhesive composition, ultraviolet curing is desirable from the viewpoint of avoiding heating of the adherend and reducing CO2 emissions, but the adhesive sheet obtained by ultraviolet curing has a problem of poor impact resistance.
本発明は、紫外線硬化により得られるものでありながら耐衝撃性に優れる粘着シートを提供することを目的とする。また、本発明は、該粘着シートを有する積層体の製造方法を提供することを目的とする。 The present invention aims to provide an adhesive sheet that is obtained by UV curing and has excellent impact resistance. The present invention also aims to provide a method for producing a laminate having the adhesive sheet.
本開示１は、光重合開始剤を含有する粘着剤組成物の硬化物である粘着シートであって、せん断法、測定温度－７０℃から２００℃、周波数１Ｈｚの条件で動的粘弾性測定を行うことにより得られる粘弾性チャートにおいて、最も低温側において損失弾性率が極大値となる温度をＧｇｔｅｍｐとし、該Ｇｇｔｅｍｐより高温の領域におけるｔａｎδが極大値となる温度のうち最も低温側にある温度をＴｇとした場合において、貯蔵弾性率と損失弾性率の比が最小となる温度のうちＴｇ以上から５０℃以下の温度領域において最も低温側にある温度をＧＦ１ｔｅｍｐとし、該ＧＦ１ｔｅｍｐより高温の領域において損失正接が極小値となる温度のうち最も低温側の温度をＧＦ２ｔｅｍｐとし、該ＧＦ２ｔｅｍｐにおける損失正接をＧＦ２ｔａｎδとしたとき、上記Ｇｇｔｅｍｐと上記ＧＦ１ｔｅｍｐとの温度差が２５．０℃以上であり、上記ＧＦ２ｔａｎδが０．３４以上である粘着シートである。
本開示２は、上記粘弾性チャートにおいて、上記ＧＦ２ｔｅｍｐより高温の領域において貯蔵弾性率が極小値となる温度、又は、上記ＧＦ２ｔｅｍｐより高温の領域において貯蔵弾性率が極小値となる温度がない場合は２００℃をＧＥｔｅｍｐとし、該ＧＥｔｅｍｐにおける損失正接をＧＥｔａｎδとし、式（ＧＥｔａｎδ－ＧＦ２ｔａｎδ）／（ＧＥｔｅｍｐ－ＧＦ２ｔｅｍｐ）で求められる値をｄｅｌｔａ　ｔａｎδとしたとき、上記ｄｅｌｔａ　ｔａｎδが－０．００６以上である本開示１の粘着シートである。
本開示３は、上記Ｇｇｔｅｍｐと上記ＧＦ１ｔｅｍｐとの温度差が５０．０℃以上である本開示１又は２の粘着シートである。
本開示４は、上記ＧＦ２ｔａｎδが０．５０以上である本開示１、２又は３の粘着シートである。
本開示５は、２５℃、５０％ＲＨの環境下で１日養生した後の上記粘着シートの２５℃におけるＳＵＳ基板に対する１８０°ピール接着力が６Ｎ／ｃｍ以上である請求項１、２、３又は４記載の粘着シートである。
本開示６は、上記粘着剤組成物は、窒素含有化合物を含有する本開示１、２、３、４又は５の粘着シートである。
本開示７は、上記窒素含有化合物は、マレイミド誘導体を含む本開示６の粘着シートである。
本開示８は、上記粘着剤組成物は、水素引き抜き型光重合開始剤及びポリマー型光重合開始剤からなる群より選択される少なくとも１種を含む本開示１、２、３、４、５、６又は７の粘着シートである。
本開示９は、上記粘着剤組成物は、熱可塑性樹脂を含有する本開示１、２、３、４、５、６、７又は８の粘着シートである。
本開示１０は、上記粘着剤組成物は、粘着付与剤を含有する本開示１、２、３、４、５、６、７、８又は９の粘着シートである。
本開示１１は、第一の被着体又はセパレータ上に、上記粘着剤組成物を塗工し、露光することにより本開示１、２、３、４、５、６、７、８、９又は１０の粘着シートを形成する工程、及び、上記粘着シート上に第二の被着体を貼付する工程を有し、上記粘着剤組成物を塗工する方法は、インクジェット印刷、スクリーン印刷、スプレーコート、スピンコート、グラビアオフセット、又は、反転オフセット印刷であり、上記粘着剤組成物が上記第一の被着体上に部分的に塗工される積層体の製造方法である。
以下に本発明を詳述する。 Disclosure 1 is a pressure-sensitive adhesive sheet that is a cured product of a pressure-sensitive adhesive composition containing a photopolymerization initiator, and in a viscoelasticity chart obtained by performing dynamic viscoelasticity measurement under conditions of a shear method, a measurement temperature of -70°C to 200°C, and a frequency of 1 Hz, when Ggtemp is the temperature at which the loss modulus is maximized on the lowest temperature side, Tg is the lowest temperature among the temperatures at which tan δ is maximized in a region higher than Ggtemp, GF1temp is the lowest temperature in a temperature region from Tg to 50°C among the temperatures at which the ratio of storage modulus to loss modulus is minimum, GF2temp is the lowest temperature among the temperatures at which the loss tangent is minimized in a region higher than GF1temp, and GF2tan δ is the loss tangent at GF2temp, the temperature difference between Ggtemp and GF1temp is 25.0°C or more, and GF2tan δ is 0.34 or more.
Disclosure 2 is a pressure-sensitive adhesive sheet according to Disclosure 1, in which, when GEtemp is the temperature at which the storage modulus becomes a minimum value in a region higher than the GF2temp in the viscoelasticity chart, or 200°C if there is no temperature at which the storage modulus becomes a minimum value in a region higher than the GF2temp, the loss tangent at the GEtemp is GEtanδ, and delta tanδ is a value calculated by the formula (GEtanδ-GF2tanδ)/(GEtemp-GF2temp), the delta tanδ is -0.006 or more.
The present disclosure 3 is the pressure-sensitive adhesive sheet of the present disclosure 1 or 2, in which the temperature difference between the Ggtemp and the GF1temp is 50.0°C or more.
The present disclosure 4 is the pressure-sensitive adhesive sheet of the present disclosure 1, 2, or 3, in which the GF2 tan δ is 0.50 or more.
The present disclosure 5 is the pressure-sensitive adhesive sheet according to claim 1, 2, 3 or 4, wherein the pressure-sensitive adhesive sheet has a 180° peel adhesive strength to a SUS substrate at 25°C of 6 N/cm or more after being aged for one day in an environment of 25°C and 50% RH.
The present disclosure 6 is the pressure-sensitive adhesive sheet according to the present disclosure 1, 2, 3, 4, or 5, wherein the pressure-sensitive adhesive composition contains a nitrogen-containing compound.
The present disclosure 7 is the pressure-sensitive adhesive sheet according to the present disclosure 6, wherein the nitrogen-containing compound includes a maleimide derivative.
The present disclosure 8 is the pressure-sensitive adhesive sheet of the present disclosure 1, 2, 3, 4, 5, 6, or 7, wherein the pressure-sensitive adhesive composition comprises at least one selected from the group consisting of a hydrogen abstraction type photopolymerization initiator and a polymer type photopolymerization initiator.
The present disclosure 9 is the pressure-sensitive adhesive sheet according to the present disclosure 1, 2, 3, 4, 5, 6, 7, or 8, wherein the pressure-sensitive adhesive composition contains a thermoplastic resin.
The present disclosure 10 is the PSA sheet of the present disclosure 1, 2, 3, 4, 5, 6, 7, 8, or 9, wherein the PSA composition contains a tackifier.
Disclosure 11 is a method for producing a laminate in which the adhesive composition is partially coated on the first adherend, the method comprising the steps of coating the adhesive composition on a first adherend or a separator and exposing the composition to light to form an adhesive sheet according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, and attaching a second adherend to the adhesive sheet, the method for coating the adhesive composition being inkjet printing, screen printing, spray coating, spin coating, gravure offset, or reverse offset printing.
The present invention will be described in detail below.
本発明者らは、粘着剤組成物を紫外線硬化させて得られる粘着シートについて、特定の条件で動的粘弾性測定を行うことにより得られる粘弾性チャートが特定の挙動を示すものとなるようにすることを検討した。その結果、耐衝撃性に優れる粘着シートを得ることができることを見出し、本発明を完成させるに至った。 The present inventors have investigated how to make a viscoelasticity chart obtained by performing dynamic viscoelasticity measurement under specific conditions on an adhesive sheet obtained by UV curing an adhesive composition exhibit specific behavior. As a result, they have found that an adhesive sheet with excellent impact resistance can be obtained, leading to the completion of the present invention.
本発明の粘着シートは、せん断法、測定温度－７０℃から２００℃、周波数１Ｈｚの条件で動的粘弾性測定を行うことにより得られる粘弾性チャートにおいて、最も低温側において損失弾性率が極大値となる温度をＧｇｔｅｍｐとし、該Ｇｇｔｅｍｐより高温の領域におけるｔａｎδが極大値となる温度のうち最も低温側にある温度をＴｇとした場合において、貯蔵弾性率と損失弾性率の比が最小となる温度のうちＴｇ以上から５０℃以下の温度領域において最も低温側にある温度をＧＦ１ｔｅｍｐとし、該ＧＦ１ｔｅｍｐより高温の領域において損失正接が極小値となる温度のうち最も低温側の温度をＧＦ２ｔｅｍｐとし、該ＧＦ２ｔｅｍｐにおける損失正接をＧＦ２ｔａｎδとしたとき、上記Ｇｇｔｅｍｐと上記ＧＦ１ｔｅｍｐとの温度差の下限が２５．０℃であり、上記ＧＦ２ｔａｎδの下限が０．３４である。粘弾性チャートにおける、上記Ｇｇｔｅｍｐ、上記ＧＦ１ｔｅｍｐ、上記ＧＦ２ｔｅｍｐ、及び、上記ＧＦ２ｔａｎδの関係を示す模式図を図１に示した。上記Ｇｇｔｅｍｐと上記ＧＦ１ｔｅｍｐとの温度差が２５．０℃以上であること、及び、上記ＧＦ２ｔａｎδが０．３４以上であることの両方を満たすことにより、本発明の粘着シートは、耐衝撃性に優れるものとなる。
上記Ｇｇｔｅｍｐと上記ＧＦ１ｔｅｍｐとの温度差の好ましい下限は４０．０℃であり、より好ましい下限は５０．０℃である。また、上記Ｇｇｔｅｍｐと上記ＧＦ１ｔｅｍｐとの温度差の好ましい上限は特にないが、実質的な上限は１２０．０℃である。
上記ＧＦ２ｔａｎδの好ましい下限は０．５０である。また、上記ＧＦ２ｔａｎδの好ましい上限は特にないが、実質的な上限は４．０である。 In the pressure-sensitive adhesive sheet of the present invention, when a temperature at which the loss modulus is maximum on the lowest temperature side is defined as Ggtemp and the lowest temperature at which tan δ is maximum in a region higher than Ggtemp is defined as Tg, the lowest temperature at which the ratio of the storage modulus to the loss modulus is minimum in a temperature region from Tg to 50°C is defined as GF1temp, the lowest temperature at which the loss tangent is minimum in a region higher than GF1temp is defined as GF2temp, and the loss tangent at GF2temp is defined as GF2tan δ, the lower limit of the temperature difference between Ggtemp and GF1temp is 25.0°C and the lower limit of GF2tan δ is 0.34. A schematic diagram showing the relationship between the Ggtemp, GF1temp, GF2temp, and GF2tan δ in a viscoelasticity chart is shown in Figure 1. By satisfying both that the temperature difference between the Ggtemp and the GF1temp is 25.0°C or more, and that the GF2tan δ is 0.34 or more, the pressure-sensitive adhesive sheet of the present invention has excellent impact resistance.
The preferred lower limit of the temperature difference between Ggtemp and GF1temp is 40.0° C., and the more preferred lower limit is 50.0° C. In addition, there is no particular preferred upper limit of the temperature difference between Ggtemp and GF1temp, but the substantial upper limit is 120.0° C.
The preferred lower limit of GF2 tan δ is 0.50. Although there is no particular preferred upper limit of GF2 tan δ, the substantial upper limit is 4.0.
本発明の粘着シートは、上記粘弾性チャートにおいて、上記ＧＦ２ｔｅｍｐより高温の領域において貯蔵弾性率が極小値となる温度、又は、上記ＧＦ２ｔｅｍｐより高温の領域において貯蔵弾性率が極小値となる温度がない場合は２００℃をＧＥｔｅｍｐとし、該ＧＥｔｅｍｐにおける損失正接をＧＥｔａｎδとし、式（ＧＥｔａｎδ－ＧＦ２ｔａｎδ）／（ＧＥｔｅｍｐ－ＧＦ２ｔｅｍｐ）で求められる値をｄｅｌｔａ　ｔａｎδとしたとき、上記ｄｅｌｔａ　ｔａｎδの好ましい下限が－０．００６である。上記ｄｅｌｔａ　ｔａｎδが－０．００６以上であることにより、上記粘着シートが耐衝撃性により優れるものとなる。上記ｄｅｌｔａ　ｔａｎδのより好ましい下限は、０．００２である。
また、上記ｄｅｌｔａ　ｔａｎδの好ましい上限は特にないが、実質的な上限は０．５である。 In the pressure-sensitive adhesive sheet of the present invention, when the temperature at which the storage modulus is a minimum value in the region higher than the GF2temp in the viscoelasticity chart, or 200°C if there is no temperature at which the storage modulus is a minimum value in the region higher than the GF2temp, the loss tangent at the GEtemp is GEtanδ, and the value calculated by the formula (GEtanδ-GF2tanδ)/(GEtemp-GF2temp) is delta tanδ, the preferred lower limit of the delta tanδ is -0.006. When the delta tanδ is -0.006 or more, the pressure-sensitive adhesive sheet has better impact resistance. The more preferred lower limit of the delta tanδ is 0.002.
Further, although there is no particular preferred upper limit for the delta tan δ, the substantial upper limit is 0.5.
上記粘弾性チャートは、具体的には例えば、動的粘弾性測定装置を用いて、以下の条件で動的粘弾性測定を行うことで得ることができる。上記動的粘弾性測定装置としては、例えば、ＭＣＲ－７０２ｅ（アントンパール社製）等を用いることができる。
＜条件＞
　せん断法：８ｍｍパラレルプレートを用いて、ツインドライブにて測定
　測定温度－７０℃～２００℃
　昇温速度：７℃／分
　周波数：１Ｈｚ
　５０℃から－７０℃まで１０℃／分で降温中、８Ｎで予備圧着させ、下記（１）～（６）の通りに低温から測定。
（１）ノーマルフォース２０Ｎにて歪０．００５％で昇温、トルク値が１５００μＮ・ｍ未満となるまでこの条件で測定。
（２）（１）の後、ノーマルフォース８Ｎにて歪０．０５％で昇温、トルク値が２００μＮ・ｍ未満となるまでこの条件で測定。
（３）（２）の後、ノーマルフォース３Ｎにて歪０．５％で昇温、トルク値が１５０μＮ・ｍ未満となるまでこの条件で測定。（３）のトルク値が１２０℃まで１５０μＮ・ｍ以上であった場合は、（４）に移行する。
（４）（３）の後、ノーマルフォース１．５Ｎにて歪２％で昇温、トルク値が１００μＮ・ｍ未満となるまでこの条件で測定。（４）のトルク値が１７０℃まで１００μＮ・ｍ以上だった場合は、（５）に移行する。
（５）（４）の後、ノーマルフォース１Ｎにて歪５％で昇温、トルク値が８０μＮ・ｍ未満となるまでこの条件で測定。（５）のトルク値が１９０℃まで８０μＮ・ｍ以上だった場合や厚みが３０μｍ未満になった場合は、（６）に移行する。
（６）（５）の後、ノーマルフォース１Ｎにて歪１０％で昇温、２００℃となるまでこの条件で測定。（６）の温度が２００℃になる前に厚みが２０μｍ未満になった際、測定を終了する。ここまで貯蔵弾性率が極小点を迎えない場合は、２００℃又は測定終了時の温度が上記ＧＥｔｅｍｐとなる。 Specifically, the viscoelasticity chart can be obtained by performing dynamic viscoelasticity measurement under the following conditions using a dynamic viscoelasticity measuring device, for example, MCR-702e (manufactured by Anton Paar) or the like.
<Conditions>
Shear method: Measured with twin drive using 8 mm parallel plate Measurement temperature: -70℃ to 200℃
Heating rate: 7°C/min Frequency: 1Hz
While cooling from 50°C to -70°C at a rate of 10°C/min, pre-pressure was applied at 8N, and measurements were taken from the low temperature as described below in (1) to (6).
(1) The temperature was raised with a normal force of 20 N and a strain of 0.005%, and measurements were taken under these conditions until the torque value became less than 1,500 μN·m.
(2) After (1), the temperature is increased with a normal force of 8 N and a strain of 0.05%, and measurements are taken under these conditions until the torque value becomes less than 200 μN·m.
(3) After (2), raise the temperature with a normal force of 3 N and a strain of 0.5%, and measure under these conditions until the torque value is less than 150 μN·m. If the torque value in (3) is 150 μN·m or more up to 120°C, proceed to (4).
(4) After (3), raise the temperature with a normal force of 1.5 N and a strain of 2%, and measure under these conditions until the torque value is less than 100 μN·m. If the torque value in (4) is 100 μN·m or more up to 170°C, proceed to (5).
(5) After (4), raise the temperature with a normal force of 1N and a strain of 5%, and measure under these conditions until the torque value is less than 80 μN·m. If the torque value in (5) is 80 μN·m or more up to 190°C or if the thickness is less than 30 μm, proceed to (6).
(6) After (5), the temperature is raised with a normal force of 1 N and a strain of 10%, and measurements are performed under these conditions until the temperature reaches 200° C. (6) When the thickness becomes less than 20 μm before the temperature reaches 200° C., the measurement is terminated. If the storage modulus does not reach a minimum point up to this point, 200° C. or the temperature at the end of the measurement becomes the GEtemp.
本発明の粘着シートは、ガラス転移温度の好ましい下限が－３０℃であり、好ましい上限が２０℃である。上記ガラス転移温度がこの範囲であることにより、各種基材への密着性により優れるものとすることができる。上記ガラス転移温度のより好ましい上限は１０℃である。
なお、上述した粘弾性チャートから導出されるｔａｎδピーク温度を上記ガラス転移温度として求めることができる。 The pressure-sensitive adhesive sheet of the present invention has a glass transition temperature of preferably −30° C. at its lower limit and 20° C. at its upper limit. By having the glass transition temperature in this range, the adhesive sheet can have better adhesion to various substrates. The more preferable upper limit of the glass transition temperature is 10° C.
The tan δ peak temperature derived from the above-mentioned viscoelasticity chart can be determined as the above-mentioned glass transition temperature.
本発明の粘着シートは、２５℃、５０％ＲＨの環境下で１日養生した後の上記粘着シートの２５℃におけるＳＵＳ基板に対する１８０°ピール接着力の好ましい下限が６Ｎ／ｃｍである。上記２５℃におけるＳＵＳ基板に対する１８０°ピール接着力が６Ｎ／ｃｍ以上であることにより、得られる粘着シートが高い接着性を要する電子部品等の接着に好適に用いることができるものとなる。上記２５℃におけるＳＵＳ基板に対する１８０°ピール接着力のより好ましい下限は８Ｎ／ｃｍである。
また、上記２５℃におけるＳＵＳ基板に対する１８０°ピール接着力の好ましい上限は特にないが、実質的な上限は２５Ｎ／ｃｍである。
上記２５℃におけるＳＵＳ基板に対する１８０°ピール接着力は、具体的には例えば、以下の方法により測定することができる。
即ち、まず、後述する粘着剤組成物を離型ＰＥＴフィルム上に塗工した後、波長３６５ｎｍ、照度２０ｍＷ／ｃｍ２の紫外線、及び、波長４０５ｎｍ、照度４０ｍＷ／ｃｍ２の光を、合計の照射量が９００ｍＪ／ｃｍ２となるように同時照射することにより硬化させ、厚み１００μｍの硬化物（粘着シート）を得る。次いで、易接着性ポリエステルフィルムにて硬化物の大気面を封止し、所定の大きさにカットして積層フィルムを作製する。その後、積層フィルムから離型ＰＥＴフィルムを剥離し、露出させた面をＳＵＳ基板に貼り合わせ、２ｋｇローラーにて一往復させることで圧着し、試験片を得る。得られた試験片を２５℃、５０％ＲＨの環境下で１日養生した後、万能試験機を用いて３００ｍｍ／ｍｉｎの速度で１８０°ピールを行うことにより、１８０°ピール接着力を測定することができる。上記万能試験機としては、例えば、テンシロン　ＲＴＩ－１３１０（エー・アンド・デイ社製）等が挙げられる。 The pressure-sensitive adhesive sheet of the present invention has a preferred lower limit of 6 N/cm in 180° peel adhesive strength to a SUS substrate at 25° C. after aging for one day in an environment of 25° C. and 50% RH. When the 180° peel adhesive strength to a SUS substrate at 25° C. is 6 N/cm or more, the resulting pressure-sensitive adhesive sheet can be suitably used for adhering electronic components and the like that require high adhesiveness. A more preferred lower limit of the 180° peel adhesive strength to a SUS substrate at 25° C. is 8 N/cm.
Further, although there is no particular upper limit to the 180° peel adhesive strength to a SUS substrate at 25° C., the substantial upper limit is 25 N/cm.
Specifically, the 180° peel adhesive strength to a SUS substrate at 25° C. can be measured, for example, by the following method.
That is, first, the adhesive composition described later is coated on a release PET film, and then cured by simultaneously irradiating ultraviolet light having a wavelength of 365 nm and an illuminance of 20 mW/cm 2 and light having a wavelength of 405 nm and an illuminance of 40 mW/cm 2 so that the total irradiation amount is 900 mJ/cm 2 , to obtain a cured product (adhesive sheet) having a thickness of 100 μm. Next, the air surface of the cured product is sealed with an easy-adhesive polyester film, and cut to a predetermined size to prepare a laminated film. Thereafter, the release PET film is peeled off from the laminated film, and the exposed surface is attached to a SUS substrate, and pressure-bonded by moving it back and forth with a 2 kg roller to obtain a test piece. After aging the obtained test piece for one day in an environment of 25 ° C. and 50% RH, the 180 ° peel adhesive strength can be measured by performing 180 ° peel at a speed of 300 mm / min using a universal testing machine. An example of the universal testing machine is Tensilon RTI-1310 (manufactured by A&D Co., Ltd.).
本発明の粘着シートは、光重合開始剤を含有する粘着剤組成物の硬化物である。即ち、本発明の粘着シートは、上記粘着剤組成物を紫外線硬化することにより得られる紫外線硬化物である。
上記粘着剤組成物の紫外線硬化物であるため、本発明の粘着シートは、ＣＯ２排出の少ない生産工程で作製されるものと言える。 The pressure-sensitive adhesive sheet of the present invention is a cured product of a pressure-sensitive adhesive composition containing a photopolymerization initiator, that is, an ultraviolet-cured product obtained by curing the pressure-sensitive adhesive composition with ultraviolet light.
Since the pressure-sensitive adhesive sheet of the present invention is an ultraviolet-cured product of the pressure-sensitive adhesive composition, it can be said that the pressure-sensitive adhesive sheet of the present invention is produced in a production process with little CO2 emission.
上記粘着剤組成物は、窒素含有化合物を含有することが好ましい。上記窒素含有化合物を含有することにより、得られる粘着シートが表面硬化性に優れるものとなる。 The pressure-sensitive adhesive composition preferably contains a nitrogen-containing compound. By containing the nitrogen-containing compound, the resulting pressure-sensitive adhesive sheet has excellent surface curing properties.
上記窒素含有化合物としては、マレイミド誘導体、窒素含有ビニル化合物等が挙げられる。なかでも、マレイミド誘導体が好ましい。
上記マレイミド誘導体の反応系は、基本的に水素引き抜き（Ｔｙｐｅ　ＩＩ）反応で進行する。水素引き抜き反応による光ラジカル重合は、酸素阻害を受け難いため、表面硬化性を高くすることができる。また、水素引き抜き反応による光ラジカル重合では、開裂（Ｔｙｐｅ　Ｉ）反応のようにリニアなポリマーではなく、ブランチポリマーが得られ、凝集力も高くなる。そのため、上記粘着剤組成物は、上記マレイミド誘導体を含有することにより、表面硬化性の低下に伴うブリードの発生や、表面硬化性及び凝集力の低下に伴う凝集破壊が起き難い粘着シートを得ることができるものとなる。
なお、本明細書において、上記「マレイミド誘導体」は、マレイミド基を有する化合物を意味する。 Examples of the nitrogen-containing compound include maleimide derivatives, nitrogen-containing vinyl compounds, etc. Among these, maleimide derivatives are preferred.
The reaction system of the maleimide derivative basically proceeds as a hydrogen abstraction (Type II) reaction. Photoradical polymerization by hydrogen abstraction reaction is not easily inhibited by oxygen, and can therefore increase the surface curability. In addition, photoradical polymerization by hydrogen abstraction reaction does not produce a linear polymer as in cleavage (Type I) reaction, but produces a branched polymer, which also has high cohesive strength. Therefore, by containing the maleimide derivative, the pressure-sensitive adhesive composition can produce a pressure-sensitive adhesive sheet that is less susceptible to bleeding due to a decrease in surface curability and cohesive failure due to a decrease in surface curability and cohesive strength.
In this specification, the above-mentioned "maleimide derivative" means a compound having a maleimide group.
上記マレイミド誘導体のうち単官能マレイミドとしては、例えば、Ｎ－シクロヘキシルマレイミド、Ｎ－ラウリルマレイミド、４－ヒドロキシフェニルマレイミド、Ｎ－（４－カルボキシシクロヘキシルメチル）マレイミド、Ｎ－フェニルマレイミド、Ｎ－（２－メチルフェニル）マレイミド、Ｎ－（４－メチルフェニル）マレイミド、Ｎ－（２，６－ジエチルフェニル）マレイミド、Ｎ－（２－クロロフェニル）マレイミド、Ｎ－メチルマレイミド、Ｎ－エチルマレイミド、Ｎ－イソプロピルマレイミド、Ｎ－ブチルマレイミド、Ｎ－ベンジルマレイミド、Ｎ－フェニルメチルマレイミド、Ｎ－（２，４，６－トリブロモフェニル）マレイミド、Ｎ－［３－（トリエトキシシリル）プロピル］マレイミド、Ｎ－オクタデセニルマレイミド、Ｎ－ドデセニルマレイミド、Ｎ－（２－メトキシフェニル）マレイミド、Ｎ－（２，４，６－トリクロロフェニル）マレイミド、Ｎ－（１－ヒドロキシフェニル）マレイミド等が挙げられる。なかでも、ヘテロ原子に水素が結合された構造を有さないマレイミド誘導体が反応率を上げる観点から選択されることが望ましい。また、接着力向上の観点からヘテロ原子に水素が結合された構造を有するマレイミド誘導体が用いられてもよい。上記単官能マレイミドとしては、具体的には、Ｎ－シクロヘキシルマレイミド、４－ヒドロキシフェニルマレイミド、及び、Ｎ－（４－カルボキシシクロヘキシルメチル）マレイミドからなる群より選択される少なくとも１種が好ましい。
また、上記マレイミド誘導体のうち多官能マレイミドとしては、例えば、Ｎ，Ｎ’－メチレンビスマレイミド、Ｎ，Ｎ’－トリメチレンビスマレイミド、Ｎ，Ｎ’－ドデカメチレンビスマレイミド、Ｎ，Ｎ’－（４，４’－ジフェニルメタン）ビスマレイミド、１，４－ジマレイミドシクロヘキサン、イソホロンビスウレタンビス（Ｎ－エチルマレイミド）、Ｎ，Ｎ’－Ｐ－フェニレンビスマレイミド、Ｎ，Ｎ’－ｍ－フェニレンビスマレイミド、Ｎ，Ｎ’－ｍ－トルイレンビスマレイミド、Ｎ，Ｎ’－４，４’－ビフェニレンビスマレイミド、Ｎ，Ｎ’－４，４’－（３，３’－ジメチル－ビフェニレン）ビスマレイミド、Ｎ，Ｎ’－４，４’－（３，３’－ジメチルジフェニルメタン）ビスマレイミド、Ｎ，Ｎ’－４，４’－（３，３’－ジエチルジフェニルメタン）ビスマレイミド、Ｎ，Ｎ’－４，４’－ジフェニルプロパンビスマレイミド、Ｎ，Ｎ’－４，４’－ジフェニルエーテルビスマレイミド、Ｎ，Ｎ’－３，３’－ジフェニルスルホンビスマレイミド、Ｎ，Ｎ’－４，４’－ジフェニルスルホンビスマレイミド等が挙げられる。
反応率を上げる観点から、上記マレイミド誘導体として、上記単官能マレイミドとこれらの多官能マレイミドとを併用してもよいが、ゲル分率が高くなるため、多量の多官能マレイミドを併用することは好ましくない。 Among the maleimide derivatives, examples of the monofunctional maleimide include N-cyclohexylmaleimide, N-laurylmaleimide, 4-hydroxyphenylmaleimide, N-(4-carboxycyclohexylmethyl)maleimide, N-phenylmaleimide, N-(2-methylphenyl)maleimide, N-(4-methylphenyl)maleimide, N-(2,6-diethylphenyl)maleimide, N-(2-chlorophenyl)maleimide, N-methylmaleimide, and N-ethylmaleimide. Examples of the monofunctional maleimide include N-isopropylmaleimide, N-butylmaleimide, N-benzylmaleimide, N-phenylmethylmaleimide, N-(2,4,6-tribromophenyl)maleimide, N-[3-(triethoxysilyl)propyl]maleimide, N-octadecenylmaleimide, N-dodecenylmaleimide, N-(2-methoxyphenyl)maleimide, N-(2,4,6-trichlorophenyl)maleimide, and N-(1-hydroxyphenyl)maleimide. Among them, it is preferable to select a maleimide derivative that does not have a structure in which hydrogen is bonded to a heteroatom from the viewpoint of increasing the reaction rate. In addition, a maleimide derivative that has a structure in which hydrogen is bonded to a heteroatom from the viewpoint of improving adhesive strength may be used. Specifically, the monofunctional maleimide is preferably at least one selected from the group consisting of N-cyclohexylmaleimide, 4-hydroxyphenylmaleimide, and N-(4-carboxycyclohexylmethyl)maleimide.
Among the maleimide derivatives, examples of polyfunctional maleimides include N,N'-methylene bismaleimide, N,N'-trimethylene bismaleimide, N,N'-dodecamethylene bismaleimide, N,N'-(4,4'-diphenylmethane) bismaleimide, 1,4-dimaleimidecyclohexane, isophorone bisurethane bis(N-ethylmaleimide), N,N'-P-phenylene bismaleimide, N,N'-m-phenylene bismaleimide, N,N'-m-toluylene bismaleimide, and N,N'-4,4'-biphenyl. bismaleimide, N,N'-4,4'-(3,3'-dimethyl-biphenylene)bismaleimide, N,N'-4,4'-(3,3'-dimethyldiphenylmethane)bismaleimide, N,N'-4,4'-(3,3'-diethyldiphenylmethane)bismaleimide, N,N'-4,4'-diphenylpropane bismaleimide, N,N'-4,4'-diphenylether bismaleimide, N,N'-3,3'-diphenylsulfone bismaleimide, and N,N'-4,4'-diphenylsulfone bismaleimide.
From the viewpoint of increasing the reaction rate, the above-mentioned monofunctional maleimide and these polyfunctional maleimides may be used in combination as the maleimide derivative. However, since the gel fraction becomes high, it is not preferable to use a large amount of the polyfunctional maleimide in combination.
上記窒素含有ビニル化合物としては、ビニル基を有するアミド化合物が好ましく、ビニル基を有する環状アミド化合物がより好ましい。 As the nitrogen-containing vinyl compound, an amide compound having a vinyl group is preferred, and a cyclic amide compound having a vinyl group is more preferred.
上記ビニル基を有する環状アミド化合物は、ラクタム構造を有することが好ましく、下記式（１）で表される化合物であることがより好ましい。 The cyclic amide compound having a vinyl group preferably has a lactam structure, and is more preferably a compound represented by the following formula (1):
Figure JPOXMLDOC01-appb-C000001
Figure JPOXMLDOC01-appb-C000001
式（１）中、ｎは、２～６の整数を表す。 In formula (1), n represents an integer from 2 to 6.
上記式（１）で表される化合物としては、例えば、Ｎ－ビニル－２－ピロリドン、Ｎ－ビニル－ε－カプロラクタム等が挙げられる。なかでも、Ｎ－ビニル－ε－カプロラクタムが好ましい。 Examples of the compound represented by the above formula (1) include N-vinyl-2-pyrrolidone and N-vinyl-ε-caprolactam. Of these, N-vinyl-ε-caprolactam is preferred.
上記ビニル基を有するアミド化合物のうち、上記ビニル基を有する環状アミド化合物以外のものとしては、例えば、Ｎ－ビニルアセトアミド等が挙げられる。 Among the above-mentioned amide compounds having a vinyl group, examples other than the above-mentioned cyclic amide compounds having a vinyl group include N-vinylacetamide, etc.
上記粘着剤組成物１００質量部中における上記窒素含有化合物の含有量の好ましい下限は０．４質量部であり、好ましい上限は１５質量部である。上記窒素含有化合物の含有量がこの範囲であることにより、得られる粘着シートが表面硬化性及び各種基材への密着性により優れるものとなる。上記窒素含有化合物の含有量のより好ましい下限は１．５質量部であり、より好ましい上限は１２質量部である。 The preferred lower limit of the content of the nitrogen-containing compound in 100 parts by mass of the adhesive composition is 0.4 parts by mass, and the preferred upper limit is 15 parts by mass. When the content of the nitrogen-containing compound is within this range, the resulting adhesive sheet has superior surface curing properties and adhesion to various substrates. A more preferred lower limit of the content of the nitrogen-containing compound is 1.5 parts by mass, and a more preferred upper limit is 12 parts by mass.
上記粘着剤組成物は、（メタ）アクリルモノマーを含有することが好ましい。上記（メタ）アクリルモノマーを含有することにより、得られる粘着剤組成物が硬化性により優れるものとなる。
なお、本明細書において上記「（メタ）アクリル」は、アクリル又はメタクリルを意味し、上記「（メタ）アクリルモノマー」は、（メタ）アクリロイル基を有するモノマーを意味し、上記「（メタ）アクリロイル」は、アクリロイル又はメタクリロイルを意味する。 The pressure-sensitive adhesive composition preferably contains a (meth)acrylic monomer. By containing the (meth)acrylic monomer, the resulting pressure-sensitive adhesive composition has better curability.
In this specification, the term "(meth)acrylic" means acrylic or methacrylic, the term "(meth)acrylic monomer" means a monomer having a (meth)acryloyl group, and the term "(meth)acryloyl" means acryloyl or methacryloyl.
上記（メタ）アクリルモノマーは、各種基材への密着性等の観点から、単官能（メタ）アクリルモノマーを含むことが好ましい。
また、本明細書において、上記「単官能（メタ）アクリルモノマー」は、１分子中に（メタ）アクリロイル基を１つ有するモノマーを意味する。 From the viewpoint of adhesion to various substrates, the (meth)acrylic monomer preferably contains a monofunctional (meth)acrylic monomer.
In this specification, the term "monofunctional (meth)acrylic monomer" refers to a monomer having one (meth)acryloyl group in one molecule.
上記単官能（メタ）アクリルモノマーとしては、例えば、単官能の（メタ）アクリル酸エステル化合物、単官能の（メタ）アクリルアミド化合物等が挙げられる。 Examples of the monofunctional (meth)acrylic monomer include monofunctional (meth)acrylic acid ester compounds, monofunctional (meth)acrylamide compounds, etc.
上記単官能の（メタ）アクリル酸エステル化合物としては、例えば、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、ｎ－ブチル（メタ）アクリレート、イソブチル（メタ）アクリレート、ｔ－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、ｎ－オクチル（メタ）アクリレート、ｎ－へプチル（メタ）アクリレート、イソオクチル（メタ）アクリレート、イソノニル（メタ）アクリレート、イソデシル（メタ）アクリレート、ラウリル（メタ）アクリレート、イソミリスチル（メタ）アクリレート、ステアリル（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、２－ヒドロキシ－３－フェノキシプロピル（メタ）アクリレート、２－ヒドロキシブチル（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、シクロヘキシル（メタ）アクリレート、イソボルニル（メタ）アクリレート、ビシクロペンテニル（メタ）アクリレート、ベンジル（メタ）アクリレート、２－メトキシエチル（メタ）アクリレート、２－エトキシエチル（メタ）アクリレート、２－ブトキシエチル（メタ）アクリレート、２－フェノキシエチル（メタ）アクリレート、メトキシエチレングリコール（メタ）アクリレート、メトキシポリエチレングリコール（メタ）アクリレート、フェノキシジエチレングリコール（メタ）アクリレート、フェノキシポリエチレングリコール（メタ）アクリレート、テトラヒドロフルフリル（メタ）アクリレート、テトラヒドロフルフリルアルコールアクリル酸多量体エステル、エチルカルビトール（メタ）アクリレート、２，２，２－トリフルオロエチル（メタ）アクリレート、２，２，３，３－テトラフルオロプロピル（メタ）アクリレート、１Ｈ，１Ｈ，５Ｈ－オクタフルオロペンチル（メタ）アクリレート、イミド（メタ）アクリレート、ジメチルアミノエチル（メタ）アクリレート、ジエチルアミノエチル（メタ）アクリレート、２－（メタ）アクリロイロキシエチルコハク酸、２－（メタ）アクリロイロキシエチルヘキサヒドロフタル酸、２－（メタ）アクリロイロキシエチル２－ヒドロキシプロピルフタレート、２－（メタ）アクリロイロキシエチルホスフェート、（３－エチルオキセタン－３－イル）メチル（メタ）アクリレート、２－（（（ブチルアミノ）カルボニル）オキシ）エチル（メタ）アクリレート、（３－プロピルオキセタン－３－イル）メチル（メタ）アクリレート、（３－ブチルオキセタン－３－イル）メチル（メタ）アクリレート、（３－エチルオキセタン－３－イル）エチル（メタ）アクリレート、（３－エチルオキセタン－３－イル）プロピル（メタ）アクリレート、（３－エチルオキセタン－３－イル）ブチル（メタ）アクリレート、（３－エチルオキセタン－３－イル）ペンチル（メタ）アクリレート、（３－エチルオキセタン－３－イル）ヘキシル（メタ）アクリレート、γ－ブチロラクトン（メタ）アクリレート、（２，２－ジメチル－１，３－ジオキソラン－４－イル）メチル（メタ）アクリレート、（２－メチル－２－エチル－１，３－ジオキソラン－４－イル）メチル（メタ）アクリレート、（２－メチル－２－イソブチル－１，３－ジオキソラン－４－イル）メチル（メタ）アクリレート、（２－シクロヘキシル－１，３－ジオキソラン－４－イル）メチル（メタ）アクリレート、環状トリメチロールプロパンホルマールアクリレート等が挙げられる。
なお、本明細書において、上記「（メタ）アクリレート」は、アクリレート又はメタクリレートを意味する。 Examples of the monofunctional (meth)acrylic acid ester compound include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, n-heptyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, isomyristyl (meth)acrylate, stearyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate. 4-hydroxybutyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, bicyclopentenyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, methoxyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, tetrahydrofurfuryl alcohol acrylic acid polymer ester, ethyl carbitol (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate, imido (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl hexahydrophthalate, 2-(meth)acryloyloxyethyl 2-hydroxypropyl phthalate, 2-(meth)acryloyloxyethyl phosphate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, 2-(((butylamino)carbonyl)oxy)ethyl (meth)acrylate, (3-propyloxetan-3-yl)methyl (meth)acrylate, (3-butyloxetan-3-yl)methyl (meth)acrylate, (3-ethyloxetane Examples of the acrylates include (3-ethyloxetan-3-yl)ethyl (meth)acrylate, (3-ethyloxetan-3-yl)propyl (meth)acrylate, (3-ethyloxetan-3-yl)butyl (meth)acrylate, (3-ethyloxetan-3-yl)pentyl (meth)acrylate, (3-ethyloxetan-3-yl)hexyl (meth)acrylate, γ-butyrolactone (meth)acrylate, (2,2-dimethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (2-methyl-2-isobutyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (2-cyclohexyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, and cyclic trimethylolpropane formal acrylate.
In this specification, the term "(meth)acrylate" means acrylate or methacrylate.
上記単官能の（メタ）アクリルアミド化合物としては、例えば、Ｎ，Ｎ－ジメチル（メタ）アクリルアミド、Ｎ－（メタ）アクリロイルモルフォリン、Ｎ－ヒドロキシエチル（メタ）アクリルアミド、Ｎ，Ｎ－ジエチル（メタ）アクリルアミド、Ｎ－イソプロピル（メタ）アクリルアミド、Ｎ，Ｎ－ジメチルアミノプロピル（メタ）アクリルアミド等が挙げられる。 Examples of the monofunctional (meth)acrylamide compounds include N,N-dimethyl(meth)acrylamide, N-(meth)acryloylmorpholine, N-hydroxyethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, and N,N-dimethylaminopropyl(meth)acrylamide.
上記粘着剤組成物１００質量部中における上記単官能（メタ）アクリルモノマーの含有量の好ましい下限は１５質量部、好ましい上限は９０質量部である。上記単官能（メタ）アクリルモノマーの含有量がこの範囲であることにより、得られる粘着剤組成物が硬化性により優れるものとなり、かつ、得られる粘着シートが各種基材への密着性により優れるものとなる。上記単官能（メタ）アクリルモノマーの含有量のより好ましい下限は２０質量部であり、より好ましい上限は６０質量部である。 The preferred lower limit of the content of the monofunctional (meth)acrylic monomer in 100 parts by mass of the adhesive composition is 15 parts by mass, and the preferred upper limit is 90 parts by mass. When the content of the monofunctional (meth)acrylic monomer is within this range, the resulting adhesive composition has better curing properties, and the resulting adhesive sheet has better adhesion to various substrates. A more preferred lower limit of the content of the monofunctional (meth)acrylic monomer is 20 parts by mass, and a more preferred upper limit is 60 parts by mass.
上記（メタ）アクリルモノマーは、多官能（メタ）アクリルモノマーを含んでいてもよい。上記多官能（メタ）アクリルモノマーは、架橋成分としての役割を有する。 The (meth)acrylic monomer may contain a polyfunctional (meth)acrylic monomer. The polyfunctional (meth)acrylic monomer serves as a cross-linking component.
上記多官能（メタ）アクリルモノマーとしては、例えば、多官能のウレタン（メタ）アクリレート、多官能の（メタ）アクリル酸エステル化合物、多官能のエポキシ（メタ）アクリレート等が挙げられる。
なお、本明細書において、上記「エポキシ（メタ）アクリレート」とは、エポキシ化合物中の全てのエポキシ基を（メタ）アクリル酸と反応させた化合物のことを表す。 Examples of the polyfunctional (meth)acrylic monomer include polyfunctional urethane (meth)acrylates, polyfunctional (meth)acrylic acid ester compounds, and polyfunctional epoxy (meth)acrylates.
In this specification, the above-mentioned "epoxy (meth)acrylate" refers to a compound in which all epoxy groups in an epoxy compound have been reacted with (meth)acrylic acid.
上記多官能のウレタン（メタ）アクリレートは、例えば、イソシアネート化合物に対して水酸基を有する（メタ）アクリル酸誘導体を、触媒量のスズ系化合物存在下で反応させることによって得ることができる。 The above-mentioned polyfunctional urethane (meth)acrylate can be obtained, for example, by reacting a (meth)acrylic acid derivative having a hydroxyl group with an isocyanate compound in the presence of a catalytic amount of a tin-based compound.
上記多官能のウレタン（メタ）アクリレートの原料となるイソシアネート化合物としては、例えば、イソホロンジイソシアネート、２，４－トリレンジイソシアネート、２，６－トリレンジイソシアネート、ヘキサメチレンジイソシアネート、トリメチルヘキサメチレンジイソシアネート、ジフェニルメタン－４，４’－ジイソシアネート（ＭＤＩ）、水添ＭＤＩ、ポリメリックＭＤＩ、１，５－ナフタレンジイソシアネート、ノルボルナンジイソシアネート、トリジンジイソシアネート、キシリレンジイソシアネート（ＸＤＩ）、水添ＸＤＩ、リジンジイソシアネート、トリフェニルメタントリイソシアネート、トリス（イソシアネートフェニル）チオフォスフェート、テトラメチルキシリレンジイソシアネート、１，６，１１－ウンデカントリイソシアネート等が挙げられる。 Examples of isocyanate compounds that are the raw material for the polyfunctional urethane (meth)acrylate include isophorone diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornane diisocyanate, tolidine diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, lysine diisocyanate, triphenylmethane triisocyanate, tris(isocyanatephenyl)thiophosphate, tetramethylxylylene diisocyanate, and 1,6,11-undecane triisocyanate.
また、上記多官能のウレタン（メタ）アクリレートの原料となるイソシアネート化合物としては、ポリオールと過剰のイソシアネート化合物との反応により得られる鎖延長されたイソシアネート化合物も使用することができる。
上記ポリオールとしては、例えば、エチレングリコール、プロピレングリコール、グリセリン、ソルビトール、トリメチロールプロパン、カーボネートジオール、ポリエーテルジオール、ポリエステルジオール、ポリカプロラクトンジオール等が挙げられる。 As the isocyanate compound serving as a raw material for the polyfunctional urethane (meth)acrylate, a chain-extended isocyanate compound obtained by reacting a polyol with an excess of an isocyanate compound can also be used.
Examples of the polyol include ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, and polycaprolactone diol.
上記水酸基を有する（メタ）アクリル酸誘導体としては、例えば、ヒドロキシアルキルモノ（メタ）アクリレート、二価のアルコールのモノ（メタ）アクリレート、三価のアルコールのモノ（メタ）アクリレート又はジ（メタ）アクリレート等が挙げられる。
上記ヒドロキシアルキルモノ（メタ）アクリレートとしては、例えば、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、２－ヒドロキシブチル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレート等が挙げられる。
上記二価のアルコールとしては、例えば、エチレングリコール、プロピレングリコール、１，３－プロパンジオール、１，３－ブタンジオール、１，４－ブタンジオール、ポリエチレングリコール等が挙げられる。
上記三価のアルコールとしては、例えば、トリメチロールエタン、トリメチロールプロパン、グリセリン等が挙げられる。 Examples of the (meth)acrylic acid derivative having a hydroxyl group include hydroxyalkyl mono(meth)acrylates, mono(meth)acrylates of dihydric alcohols, and mono(meth)acrylates or di(meth)acrylates of trihydric alcohols.
Examples of the hydroxyalkyl mono(meth)acrylate include 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, and 4-hydroxybutyl(meth)acrylate.
Examples of the dihydric alcohol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol.
Examples of the trihydric alcohol include trimethylolethane, trimethylolpropane, and glycerin.
上記多官能の（メタ）アクリル酸エステル化合物としては、例えば、１，３－ブタンジオールジ（メタ）アクリレート、１，４－ブタンジオールジ（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、１，９－ノナンジオールジ（メタ）アクリレート、１，１０－デカンジオールジ（メタ）アクリレート、エチレングリコールジ（メタ）アクリレート、ジエチレングリコールジ（メタ）アクリレート、テトラエチレングリコールジ（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、２－ｎ－ブチル－２－エチル－１，３－プロパンジオールジ（メタ）アクリレート、ジプロピレングリコールジ（メタ）アクリレート、トリプロピレングリコールジ（メタ）アクリレート、ポリプロピレングリコールジ（メタ）アクリレート、ネオペンチルグリコールジ（メタ）アクリレート、エチレンオキシド付加ビスフェノールＡジ（メタ）アクリレート、プロピレンオキシド付加ビスフェノールＡジ（メタ）アクリレート、エチレンオキシド付加ビスフェノールＦジ（メタ）アクリレート、ジメチロールジシクロペンタジエニルジ（メタ）アクリレート、エチレンオキシド変性イソシアヌル酸ジ（メタ）アクリレート、２－ヒドロキシ－３－（メタ）アクリロイロキシプロピル（メタ）アクリレート、カーボネートジオールジ（メタ）アクリレート、ポリエーテルジオールジ（メタ）アクリレート、ポリエステルジオールジ（メタ）アクリレート、ポリカプロラクトンジオールジ（メタ）アクリレート、ポリブタジエンジオールジ（メタ）アクリレート、トリシクロデカンジメタノールジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、エチレンオキシド付加トリメチロールプロパントリ（メタ）アクリレート、プロピレンオキシド付加トリメチロールプロパントリ（メタ）アクリレート、カプロラクトン変性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、エチレンオキシド付加イソシアヌル酸トリ（メタ）アクリレート、グリセリントリ（メタ）アクリレート、プロピレンオキシド付加グリセリントリ（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、トリス（メタ）アクリロイルオキシエチルフォスフェート、ジトリメチロールプロパンテトラ（メタ）アクリレート、ペンタエリスリトールテトラ（メタ）アクリレート、ジペンタエリスリトールペンタ（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、カプロラクトン変性ジペンタエリスリトールヘキサ（メタ）アクリレート等が挙げられる。 Examples of the polyfunctional (meth)acrylic acid ester compounds include 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide-added bisphenol A di(meth)acrylate, propylene oxide-added bisphenol A di(meth)acrylate, ethylene oxide-added bisphenol F di(meth)acrylate, dimethylol dicyclopentadienyl di(meth)acrylate, ethylene oxide-modified isocyanuric acid di(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, carbonate diol di(meth)acryloyloxypropyl (meth)acrylate acrylate, polyether diol di(meth)acrylate, polyester diol di(meth)acrylate, polycaprolactone diol di(meth)acrylate, polybutadiene diol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethylene oxide added trimethylolpropane tri(meth)acrylate, propylene oxide added trimethylolpropane tri(meth)acrylate, caprolactone modified trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, ethylene oxide added isocyanate Examples of such acrylates include anuric acid tri(meth)acrylate, glycerin tri(meth)acrylate, propylene oxide-added glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(meth)acryloyloxyethyl phosphate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate.
上記多官能のエポキシ（メタ）アクリレートとしては、例えば、ビスフェノールＡ型エポキシ（メタ）アクリレート、ビスフェノールＦ型エポキシ（メタ）アクリレート、ビスフェノールＥ型エポキシ（メタ）アクリレート、及び、これらのカプロラクトン変性体等が挙げられる。 Examples of the polyfunctional epoxy (meth)acrylate include bisphenol A type epoxy (meth)acrylate, bisphenol F type epoxy (meth)acrylate, bisphenol E type epoxy (meth)acrylate, and caprolactone modified versions of these.
上記粘着剤組成物１００質量部中における上記多官能（メタ）アクリルモノマーの含有量の好ましい下限は０．５質量部、好ましい上限は１０質量部である。上記多官能（メタ）アクリルモノマーの含有量がこの範囲であることにより、得られる粘着剤組成物が凝集力により優れるものとなり、かつ、得られる粘着シートが各種基材への密着性により優れるものとなる。上記多官能（メタ）アクリルモノマーの含有量のより好ましい下限は１．５質量部であり、より好ましい上限は６質量部である。 The preferred lower limit of the content of the polyfunctional (meth)acrylic monomer in 100 parts by mass of the pressure-sensitive adhesive composition is 0.5 parts by mass, and the preferred upper limit is 10 parts by mass. When the content of the polyfunctional (meth)acrylic monomer is within this range, the resulting pressure-sensitive adhesive composition has superior cohesive strength, and the resulting pressure-sensitive adhesive sheet has superior adhesion to various substrates. A more preferred lower limit of the content of the polyfunctional (meth)acrylic monomer is 1.5 parts by mass, and a more preferred upper limit is 6 parts by mass.
上記（メタ）アクリルモノマーは、水素供与体となり得るモノマーを含むことが好ましい。
上記水素供与体となり得るモノマーは、エーテル結合、アセチル基、フェノキシ基、ベンジル基、及び、アミド結合からなる群より選択される少なくとも１種の構造を有するモノマーであることが好ましい。上記水素供与体となり得るモノマーが、エーテル結合、アセチル基、フェノキシ基、ベンジル基、及び、アミド結合からなる群より選択される少なくとも１種の構造を有するモノマーであることにより、より容易に水素引き抜き反応に水素を供することができるものとなる。なかでも、上記水素供与体となり得るモノマーは、エーテル結合、フェノキシ基、及び、アミド結合からなる群より選択される少なくとも１種の構造を有するモノマーであることがより好ましい。 The (meth)acrylic monomer preferably contains a monomer capable of acting as a hydrogen donor.
The monomer capable of serving as a hydrogen donor is preferably a monomer having at least one structure selected from the group consisting of an ether bond, an acetyl group, a phenoxy group, a benzyl group, and an amide bond. The monomer capable of serving as a hydrogen donor is preferably a monomer having at least one structure selected from the group consisting of an ether bond, an acetyl group, a phenoxy group, a benzyl group, and an amide bond, so that the monomer can more easily provide hydrogen to a hydrogen abstraction reaction. In particular, the monomer capable of serving as a hydrogen donor is more preferably a monomer having at least one structure selected from the group consisting of an ether bond, a phenoxy group, and an amide bond.
上記（メタ）アクリルモノマーは、エーテル結合、アセチル基、フェノキシ基、ベンジル基、及び、アミド結合からなる群より選択される少なくとも１種の構造を有するモノマーを５０質量％以上含むことが好ましい。上記（メタ）アクリルモノマーが、エーテル結合、アセチル基、フェノキシ基、ベンジル基、及び、アミド結合からなる群より選択される少なくとも１種の構造を有するモノマーを５０質量％以上含むことにより、得られる粘着剤組成物が表面硬化性により優れるものとなる。上記（メタ）アクリルモノマーは、エーテル結合、アセチル基、フェノキシ基、ベンジル基、及び、アミド結合からなる群より選択される少なくとも１種の構造を有するモノマーを７０質量％以上含むことがより好ましい。
また、上記（メタ）アクリルモノマーは、エーテル結合、アセチル基、フェノキシ基、ベンジル基、及び、アミド結合からなる群より選択される少なくとも１種の構造を有するモノマーのみを含むものであってもよい。 The (meth)acrylic monomer preferably contains 50% by mass or more of a monomer having at least one structure selected from the group consisting of an ether bond, an acetyl group, a phenoxy group, a benzyl group, and an amide bond. The (meth)acrylic monomer contains 50% by mass or more of a monomer having at least one structure selected from the group consisting of an ether bond, an acetyl group, a phenoxy group, a benzyl group, and an amide bond, so that the resulting pressure-sensitive adhesive composition has better surface curing properties. The (meth)acrylic monomer more preferably contains 70% by mass or more of a monomer having at least one structure selected from the group consisting of an ether bond, an acetyl group, a phenoxy group, a benzyl group, and an amide bond.
The (meth)acrylic monomer may contain only a monomer having at least one structure selected from the group consisting of an ether bond, an acetyl group, a phenoxy group, a benzyl group, and an amide bond.
上記粘着剤組成物は、光重合開始剤を含有する。
上記光重合開始剤は、水素引き抜き型光重合開始剤及びポリマー型光重合開始剤からなる群より選択される少なくとも１種を含むことが好ましい。上記光重合開始剤として上記水素引き抜き型光重合開始剤及び上記ポリマー型光重合開始剤からなる群より選択される少なくとも１種を、後述するアミン化合物と組み合わせて用いることにより、得られる粘着シートが、表面硬化性の低下に伴うブリードの発生や、表面硬化性及び凝集力の低下に伴う凝集破壊がより起き難いものとなる。 The pressure-sensitive adhesive composition contains a photopolymerization initiator.
The photopolymerization initiator preferably includes at least one selected from the group consisting of hydrogen abstraction type photopolymerization initiators and polymer type photopolymerization initiators. By using at least one selected from the group consisting of hydrogen abstraction type photopolymerization initiators and polymer type photopolymerization initiators as the photopolymerization initiator in combination with an amine compound described later, the resulting pressure-sensitive adhesive sheet is less susceptible to bleeding due to a decrease in surface curability and cohesive failure due to a decrease in surface curability and cohesive strength.
上記水素引き抜き型光重合開始剤としては、ベンゾフェノン系光重合開始剤が好ましい。上記ベンゾフェノン系光重合開始剤としては、例えば、ベンゾフェノン、４－クロロベンゾフェノン、４，４’－ジメチルベンゾフェノン、４－メチルベンゾフェノン、２，４，６－トリメチルベンゾフェノン、ｏ－ベンゾイル安息香酸メチル、３，３’－ジメチル－４－メトキシベンゾフェノン、４－フェニルベンゾフェノン、４－ベンゾイル－４’－メチル－ジフェニルサルファイド、４－モルフォリノベンゾフェノン、４，４’－ジフェノキベンゾフェノン、４－ヒドロキシベンゾフェノン、２－カルボキシベンゾフェノン、２－ヒドロキシ－１－（４－（４－（２－ヒドロキシ－２－メチル－プロピオニル）－ベンジル）－フェニル）－２－メチル－プロパン－１－オン、１－（４－（４－ベンゾイルフェニルチオ）フェニル）－２－トシル－２－メチル－１－プロパノン、３－ケトクマリン等が挙げられる。 The hydrogen abstraction type photopolymerization initiator is preferably a benzophenone-based photopolymerization initiator. Examples of the benzophenone-based photopolymerization initiator include benzophenone, 4-chlorobenzophenone, 4,4'-dimethylbenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, o-benzoyl methyl benzoate, 3,3'-dimethyl-4-methoxybenzophenone, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 4-morpholinobenzophenone, 4,4'-diphenoxybenzophenone, 4-hydroxybenzophenone, 2-carboxybenzophenone, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methyl-propionyl)-benzyl)-phenyl)-2-methyl-propan-1-one, 1-(4-(4-benzoylphenylthio)phenyl)-2-tosyl-2-methyl-1-propanone, and 3-ketocoumarin.
上記ポリマー型光重合開始剤としては、例えば、エチル（２，４，６－トリメチルベンゾイル）－フェニルフォスフィネートの重合体、ポリエチレングリコールジ（β－４（４－（２－ジメチルアミノ－２－ベンジル）ブタノイルフェニル）ピペラジン）プロピオネート、ビス（ベンゾフェノン－２－カルボン酸）ポリエチレングリコールエステル等が挙げられる。 Examples of the polymeric photopolymerization initiator include polymers of ethyl (2,4,6-trimethylbenzoyl)-phenyl phosphonate, polyethylene glycol di(β-4(4-(2-dimethylamino-2-benzyl)butanoylphenyl)piperazine)propionate, and bis(benzophenone-2-carboxylic acid) polyethylene glycol ester.
上記ポリマー型光重合開始剤のうち市販されているものとしては、例えば、Ｏｍｎｉｐｏｌ　ＴＰ、Ｏｍｎｉｐｏｌ　９１０、Ｏｍｎｉｐｏｌ　２７０２（いずれもＩＧＭ　Ｒｅｓｉｎｓ社製）等が挙げられる。 Commercially available examples of the above polymer-type photopolymerization initiators include Omnipol TP, Omnipol 910, and Omnipol 2702 (all manufactured by IGM Resins).
上記光重合開始剤としては、開裂型光重合開始剤を用いることもできる。
上記開裂型光重合開始剤としては、例えば、１－ヒドロキシシクロヘキシルフェニルケトン、２，４，６－トリメチルベンゾイルジフェニルホスフィンオキサイド、ビス（２，４，６－トリメチルベンゾイル）フェニルホスフィンオキサイド等が挙げられる。 As the photopolymerization initiator, a cleavage type photopolymerization initiator can also be used.
Examples of the cleavage type photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.
上記粘着剤組成物１００質量部中における上記光重合開始剤の含有量の好ましい下限は１質量部、好ましい上限は１５質量部である。上記光重合開始剤の含有量がこの範囲であることにより、得られる粘着剤組成物が保存安定性及び硬化性により優れるものとなり、かつ、得られる粘着シートが各種基材への密着性により優れるものとなる。上記光重合開始剤の含有量のより好ましい下限は３質量部であり、より好ましい上限は８質量部である。 The preferred lower limit of the content of the photopolymerization initiator in 100 parts by mass of the pressure-sensitive adhesive composition is 1 part by mass, and the preferred upper limit is 15 parts by mass. When the content of the photopolymerization initiator is within this range, the resulting pressure-sensitive adhesive composition has better storage stability and curing properties, and the resulting pressure-sensitive adhesive sheet has better adhesion to various substrates. A more preferred lower limit of the content of the photopolymerization initiator is 3 parts by mass, and a more preferred upper limit is 8 parts by mass.
上記粘着剤組成物は、アミン化合物を含有することが好ましい。
上述したように、上記アミン化合物を、上記水素引き抜き型光重合開始剤及び上記ポリマー型光重合開始剤からなる群より選択される少なくとも１種と組み合わせて用いることにより、得られる粘着シートが、表面硬化性の低下に伴うブリードの発生や、表面硬化性及び凝集力の低下に伴う凝集破壊がより起き難いものとなる。 The pressure-sensitive adhesive composition preferably contains an amine compound.
As described above, by using the amine compound in combination with at least one selected from the group consisting of the hydrogen abstraction type photopolymerization initiator and the polymer type photopolymerization initiator, the resulting pressure-sensitive adhesive sheet is less susceptible to bleeding due to reduced surface curability and cohesive failure due to reduced surface curability and cohesive strength.
上記アミン化合物としては、例えば、（ビス－Ｎ，Ｎ－（４－ジメチルアミノベンゾイル）オキシエチレン－１－イル）－メチルアミン、ビス（２－モルホリノエチル）エーテル、デカン二酸１－メチル１０－（１，２，２，６，６－ペンタメチル－４－ピペリジニル）、テトラキス（１，２，２，６，６－ペンタメチル－４－ピペリジル）ブタン－１，２，３，４－テトラカルボキシレート、セバシン酸ビス（１，２，２，６，６－ペンタメチル－４－ピペリジル）等が挙げられる。 Examples of the amine compounds include (bis-N,N-(4-dimethylaminobenzoyl)oxyethylene-1-yl)-methylamine, bis(2-morpholinoethyl)ether, 1-methyl 10-(1,2,2,6,6-pentamethyl-4-piperidinyl) decanedioate, tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate, and bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate.
上記粘着剤組成物１００質量部中における上記アミン化合物の含有量の好ましい下限は０．５質量部、好ましい上限は５質量部である。上記アミン化合物の含有量が０．５質量部以上であることにより、得られる粘着剤組成物が表面硬化性により優れるものとなる。上記アミン化合物の含有量が５質量部以下であることにより、得られる粘着シートが凝集破壊を起こし難いものとなる。上記アミン化合物の含有量のより好ましい下限は１．５質量部であり、より好ましい上限は３質量部である。 The preferred lower limit of the content of the amine compound in 100 parts by mass of the adhesive composition is 0.5 parts by mass, and the preferred upper limit is 5 parts by mass. When the content of the amine compound is 0.5 parts by mass or more, the resulting adhesive composition has better surface curing properties. When the content of the amine compound is 5 parts by mass or less, the resulting adhesive sheet is less likely to cause cohesive failure. A more preferred lower limit of the content of the amine compound is 1.5 parts by mass, and a more preferred upper limit is 3 parts by mass.
上記粘着剤組成物は、熱可塑性樹脂を含有することが好ましい。
上記熱可塑性樹脂としては、反応性二重結合を化合物中に含まないか、又は、反応性二重結合を有していても実質的に光ラジカル重合反応性を示さない化合物が好ましい。 The pressure-sensitive adhesive composition preferably contains a thermoplastic resin.
The thermoplastic resin is preferably a compound that does not contain a reactive double bond, or a compound that has a reactive double bond but does not substantially exhibit photoradical polymerization reactivity.
上記熱可塑性樹脂としては、例えば、無溶剤系アクリルポリマーや、溶剤に溶解したポリマーを乾燥させることで得られるポリマー等が挙げられる。
上記無溶剤系アクリルポリマーとしては、例えば、アルキル基の炭素数が１～２０の（メタ）アクリル酸アルキルエステルの中から選ばれる少なくとも１種の単量体の重合体、又は該単量体と他の共重合可能な単量体との共重合体等が挙げられる。
上記無溶剤系アクリルポリマーのうち市販されているものとしては、例えば、ＡＲＵＦＯＮ－ＵＰ１０００シリーズ、ＵＨ２０００シリーズ、ＵＣ３０００シリーズ（いずれも東亞合成社製）、クラリティＬＡシリーズ、クラリティＬＫシリーズ（いずれもクラレ社製）等が挙げられる。 Examples of the thermoplastic resin include a solvent-free acrylic polymer and a polymer obtained by drying a polymer dissolved in a solvent.
Examples of the solvent-free acrylic polymer include a polymer of at least one monomer selected from (meth)acrylic acid alkyl esters having an alkyl group with 1 to 20 carbon atoms, and a copolymer of the monomer and another copolymerizable monomer.
Among the above-mentioned solvent-free acrylic polymers, commercially available ones include, for example, the ARUFON-UP1000 series, UH2000 series, UC3000 series (all manufactured by Toagosei Co., Ltd.), the Clarity LA series, and the Clarity LK series (all manufactured by Kuraray Co., Ltd.).
上記粘着剤組成物１００質量部中における上記熱可塑性樹脂の含有量の好ましい下限は５質量部、好ましい上限は４５質量部である。上記熱可塑性樹脂の含有量がこの範囲であることにより、得られる粘着剤組成物の粘度が向上し、厚い塗膜を形成することができ、印刷性により優れるものとなり、高温での粘着性の低下も抑制することができる。上記熱可塑性樹脂の含有量のより好ましい下限は１０質量部であり、より好ましい上限は２５質量部である。 The preferred lower limit of the content of the thermoplastic resin in 100 parts by mass of the pressure-sensitive adhesive composition is 5 parts by mass, and the preferred upper limit is 45 parts by mass. When the content of the thermoplastic resin is within this range, the viscosity of the resulting pressure-sensitive adhesive composition is improved, a thick coating film can be formed, the printability is superior, and the decrease in adhesion at high temperatures can be suppressed. A more preferred lower limit of the content of the thermoplastic resin is 10 parts by mass, and a more preferred upper limit is 25 parts by mass.
上記粘着剤組成物は、熱硬化性樹脂や湿気硬化性樹脂を含有することにより、熱、湿気等のトリガーに対して反応性を示すものを含んでもよい。 The adhesive composition may contain a thermosetting resin or a moisture-curing resin, and thus may exhibit reactivity to triggers such as heat and moisture.
上記熱硬化性樹脂としては、例えば、エポキシ樹脂、フェノール樹脂、尿素樹脂、メラミン樹脂等が挙げられる。なかでも、エポキシ樹脂が好ましい。
上記エポキシ樹脂としては、例えば、ビスフェノールＡ型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂、ビスフェノールＳ型エポキシ樹脂、フェノールノボラック型エポキシ樹脂、ビフェニル型エポキシ樹脂、ビフェニルノボラック型エポキシ樹脂、ビフェノール型エポキシ樹脂、ナフタレン型エポキシ樹脂、フルオレン型エポキシ樹脂、フェノールアラルキル型エポキシ樹脂、ナフトールアラルキル型エポキシ樹脂、ジシクロペンタジエン型エポキシ樹脂、アントラセン型エポキシ樹脂、アダマンタン骨格を有するエポキシ樹脂、トリシクロデカン骨格を有するエポキシ樹脂、トリアジン核を骨格に有するエポキシ樹脂等が挙げられる。 Examples of the thermosetting resin include epoxy resin, phenol resin, urea resin, melamine resin, etc. Among these, epoxy resin is preferable.
Examples of the epoxy resin include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, phenol novolac type epoxy resins, biphenyl type epoxy resins, biphenyl novolac type epoxy resins, biphenol type epoxy resins, naphthalene type epoxy resins, fluorene type epoxy resins, phenol aralkyl type epoxy resins, naphthol aralkyl type epoxy resins, dicyclopentadiene type epoxy resins, anthracene type epoxy resins, epoxy resins having an adamantane skeleton, epoxy resins having a tricyclodecane skeleton, and epoxy resins having a triazine nucleus in the skeleton.
上記熱硬化性樹脂を用いる場合は、熱硬化剤を上記粘着剤組成物に含有させることが好ましい。
上記熱硬化剤としては、例えば、シアネートエステル化合物（シアネートエステル硬化剤）、フェノール化合物（フェノール熱硬化剤）、アミン化合物（アミン熱硬化剤）、チオール化合物（チオール熱硬化剤）、イミダゾール化合物、ホスフィン化合物、酸無水物、活性エステル化合物、ジシアンジアミド等が挙げられる。
また、上記熱硬化性樹脂としてエポキシ樹脂を使用する場合は、光カチオン重合開始剤を粘着剤組成物に含有させてもよい。これにより、１段階目で活性エネルギー線を照射した後でも、徐々に硬化が進行しやすくなる。その結果、得られる粘着シートが初期接着力により一層優れたものとなる。 When the thermosetting resin is used, it is preferable that a thermosetting agent is contained in the pressure-sensitive adhesive composition.
Examples of the heat curing agent include cyanate ester compounds (cyanate ester curing agents), phenol compounds (phenol heat curing agents), amine compounds (amine heat curing agents), thiol compounds (thiol heat curing agents), imidazole compounds, phosphine compounds, acid anhydrides, active ester compounds, and dicyandiamide.
In addition, when an epoxy resin is used as the thermosetting resin, a photocationic polymerization initiator may be contained in the adhesive composition. This allows the curing to proceed gradually even after the first stage of irradiation with active energy rays. As a result, the resulting adhesive sheet has even better initial adhesive strength.
上記光カチオン重合開始剤は、光照射によりプロトン酸又はルイス酸を発生するものであれば特に限定されず、イオン性光酸発生型であってもよいし、非イオン性光酸発生型であってもよい。 The photocationic polymerization initiator is not particularly limited as long as it generates a protonic acid or a Lewis acid upon irradiation with light, and may be an ionic photoacid generating type or a non-ionic photoacid generating type.
上記イオン性光酸発生型の光カチオン重合開始剤としては、例えば、次のものが挙げられる。即ち、カチオン部分が芳香族スルホニウム、芳香族ヨードニウム、芳香族ジアゾニウム、芳香族アンモニウム、又は、（２，４－シクロペンタジエン－１－イル）（（１－メチルエチル）ベンゼン）－Ｆｅカチオンであり、アニオン部分がＢＦ４ －、ＰＦ６ －、ＳｂＦ６ －、又は、（ＢＸ４）－で構成されるオニウム塩等が挙げられる。前記Ｘは、少なくとも２つ以上のフッ素又はトリフルオロメチル基で置換されたフェニル基を表す。 Examples of the ionic photoacid generating type photocationic polymerization initiator include the following: onium salts in which the cationic moiety is an aromatic sulfonium, aromatic iodonium, aromatic diazonium, aromatic ammonium, or (2,4-cyclopentadiene-1-yl)((1-methylethyl)benzene)-Fe cation and the anionic moiety is BF 4 - , PF 6 - , SbF 6 - , or (BX 4 ) - , where X represents a phenyl group substituted with at least two or more fluorine or trifluoromethyl groups.
上記芳香族スルホニウム塩としては、例えば、ビス（４－（ジフェニルスルホニオ）フェニル）スルフィドビスヘキサフルオロホスフェート、ビス（４－（ジフェニルスルホニオ）フェニル）スルフィドビスヘキサフルオロアンチモネート、ビス（４－（ジフェニルスルホニオ）フェニル）スルフィドビステトラフルオロボレート、ビス（４－（ジフェニルスルホニオ）フェニル）スルフィドテトラキス（ペンタフルオロフェニル）ボレート、ジフェニル－４－（フェニルチオ）フェニルスルホニウムヘキサフルオロホスフェート、ジフェニル－４－（フェニルチオ）フェニルスルホニウムヘキサフルオロアンチモネート、ジフェニル－４－（フェニルチオ）フェニルスルホニウムテトラフルオロボレート、ジフェニル－４－（フェニルチオ）フェニルスルホニウムテトラキス（ペンタフルオロフェニル）ボレート、トリフェニルスルホニウムヘキサフルオロホスフェート、トリフェニルスルホニウムヘキサフルオロアンチモネート、トリフェニルスルホニウムテトラフルオロボレート、トリフェニルスルホニウムテトラキス（ペンタフルオロフェニル）ボレート、ビス（４－（ジ（４－（２－ヒドロキシエトキシ））フェニルスルホニオ）フェニル）スルフィドビスヘキサフルオロホスフェート、ビス（４－（ジ（４－（２－ヒドロキシエトキシ））フェニルスルホニオ）フェニル）スルフィドビスヘキサフルオロアンチモネート、ビス（４－（ジ（４－（２－ヒドロキシエトキシ））フェニルスルホニオ）フェニル）スルフィドビステトラフルオロボレート、ビス（４－（ジ（４－（２－ヒドロキシエトキシ））フェニルスルホニオ）フェニル）スルフィドテトラキス（ペンタフルオロフェニル）ボレート等が挙げられる。 The above aromatic sulfonium salts include, for example, bis(4-(diphenylsulfonio)phenyl)sulfide bishexafluorophosphate, bis(4-(diphenylsulfonio)phenyl)sulfide bishexafluoroantimonate, bis(4-(diphenylsulfonio)phenyl)sulfide bistetrafluoroborate, bis(4-(diphenylsulfonio)phenyl)sulfide tetrakis(pentafluorophenyl)borate, diphenyl-4-(phenylthio)phenylsulfonium hexafluorophosphate, diphenyl-4-(phenylthio)phenylsulfonium hexafluoroantimonate, diphenyl-4-(phenylthio)phenylsulfonium tetrafluoroborate, and diphenyl-4-(phenylthio)phenylsulfonium tetrakis(pentafluorophenyl)borate. , triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis(pentafluorophenyl)borate, bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl)sulfide bishexafluorophosphate, bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl)sulfide bishexafluoroantimonate, bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl)sulfide bistetrafluoroborate, bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl)sulfide tetrakis(pentafluorophenyl)borate, etc.
上記芳香族ジアゾニウム塩としては、例えば、フェニルジアゾニウムヘキサフルオロホスフェート、フェニルジアゾニウムヘキサフルオロアンチモネート、フェニルジアゾニウムテトラフルオロボレート、フェニルジアゾニウムテトラキス（ペンタフルオロフェニル）ボレート等が挙げられる。 Examples of the aromatic diazonium salt include phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, phenyldiazonium tetrafluoroborate, and phenyldiazonium tetrakis(pentafluorophenyl)borate.
上記芳香族アンモニウム塩としては、例えば、１－ベンジル－２－シアノピリジニウムヘキサフルオロホスフェート、１－ベンジル－２－シアノピリジニウムヘキサフルオロアンチモネート、１－ベンジル－２－シアノピリジニウムテトラフルオロボレート、１－ベンジル－２－シアノピリジニウムテトラキス（ペンタフルオロフェニル）ボレート、１－（ナフチルメチル）－２－シアノピリジニウムヘキサフルオロホスフェート、１－（ナフチルメチル）－２－シアノピリジニウムヘキサフルオロアンチモネート、１－（ナフチルメチル）－２－シアノピリジニウムテトラフルオロボレート、１－（ナフチルメチル）－２－シアノピリジニウムテトラキス（ペンタフルオロフェニル）ボレート等が挙げられる。 Examples of the aromatic ammonium salts include 1-benzyl-2-cyanopyridinium hexafluorophosphate, 1-benzyl-2-cyanopyridinium hexafluoroantimonate, 1-benzyl-2-cyanopyridinium tetrafluoroborate, 1-benzyl-2-cyanopyridinium tetrakis(pentafluorophenyl)borate, 1-(naphthylmethyl)-2-cyanopyridinium hexafluorophosphate, 1-(naphthylmethyl)-2-cyanopyridinium hexafluoroantimonate, 1-(naphthylmethyl)-2-cyanopyridinium tetrafluoroborate, and 1-(naphthylmethyl)-2-cyanopyridinium tetrakis(pentafluorophenyl)borate.
上記（２，４－シクロペンタジエン－１－イル）（（１－メチルエチル）ベンゼン）－Ｆｅ塩としては、例えば、（２，４－シクロペンタジエン－１－イル）（（１－メチルエチル）ベンゼン）－Ｆｅ（ＩＩ）ヘキサフルオロホスフェート、（２，４－シクロペンタジエン－１－イル）（（１－メチルエチル）ベンゼン）－Ｆｅ（ＩＩ）ヘキサフルオロアンチモネート、（２，４－シクロペンタジエン－１－イル）（（１－メチルエチル）ベンゼン）－Ｆｅ（ＩＩ）テトラフルオロボレート、（２，４－シクロペンタジエン－１－イル）（（１－メチルエチル）ベンゼン）－Ｆｅ（ＩＩ）テトラキス（ペンタフルオロフェニル）ボレート等が挙げられる。 Examples of the (2,4-cyclopentadiene-1-yl)((1-methylethyl)benzene)-Fe salt include (2,4-cyclopentadiene-1-yl)((1-methylethyl)benzene)-Fe(II) hexafluorophosphate, (2,4-cyclopentadiene-1-yl)((1-methylethyl)benzene)-Fe(II) hexafluoroantimonate, (2,4-cyclopentadiene-1-yl)((1-methylethyl)benzene)-Fe(II) tetrafluoroborate, and (2,4-cyclopentadiene-1-yl)((1-methylethyl)benzene)-Fe(II) tetrakis(pentafluorophenyl)borate.
上記非イオン性光酸発生型の光カチオン重合開始剤としては、例えば、ニトロベンジルエステル、スルホン酸誘導体、リン酸エステル、フェノールスルホン酸エステル、ジアゾナフトキノン、Ｎ－ヒドロキシイミドスホナート等が挙げられる。 Examples of the nonionic photoacid generating cationic photopolymerization initiator include nitrobenzyl esters, sulfonic acid derivatives, phosphate esters, phenolsulfonic acid esters, diazonaphthoquinones, and N-hydroxyimidesulfonates.
上記光カチオン重合開始剤は、単独で用いてもよく、２種以上を併用して用いてもよい。
上記光カチオン重合開始剤の含有量は、上記エポキシ樹脂１００質量部に対して、好ましい下限が０．１質量部、好ましい上限が１０質量部である。 The above cationic photopolymerization initiators may be used alone or in combination of two or more kinds.
The content of the photocationic polymerization initiator is preferably such that the lower limit is 0.1 parts by mass and the upper limit is 10 parts by mass relative to 100 parts by mass of the epoxy resin.
上記湿気硬化性樹脂としては、例えば、湿気硬化性ウレタン樹脂、架橋性シリル基を有する樹脂等が挙げられる。なかでも、湿気硬化性ウレタン樹脂が好ましい。湿気硬化性ウレタン樹脂は、ウレタン結合とイソシアネート基とを有し、分子内のイソシアネート基が、水分と反応して硬化する。イソシアネート基は分子の末端に有することが好ましい。
上記湿気硬化性ウレタン樹脂は、ラジカル反応性官能基を有してもよい。
上記湿気硬化性ウレタン樹脂は、１分子中に２個以上の水酸基を有するポリオール化合物と、１分子中に２個以上のイソシアネート基を有するポリイソシアネート化合物とを反応させることにより得ることができる。 Examples of the moisture-curing resin include moisture-curing urethane resin and resin having a crosslinkable silyl group. Among them, moisture-curing urethane resin is preferable. Moisture-curing urethane resin has a urethane bond and an isocyanate group, and the isocyanate group in the molecule reacts with moisture to cure. It is preferable that the isocyanate group is at the end of the molecule.
The moisture-curable urethane resin may have a radical reactive functional group.
The moisture-curable urethane resin can be obtained by reacting a polyol compound having two or more hydroxyl groups in one molecule with a polyisocyanate compound having two or more isocyanate groups in one molecule.
上記湿気硬化性樹脂を用いる場合は、湿気硬化時の硬化速度を向上させる観点から、湿気硬化促進剤を上記粘着剤組成物に含有させることが好ましい。
上記湿気硬化促進剤としては、例えば、モルホリン骨格を有する化合物、ピペリジン骨格を有する化合物、ピペラジン骨格を有する化合物等が挙げられる。 When the moisture-curable resin is used, it is preferable to add a moisture-curing accelerator to the pressure-sensitive adhesive composition from the viewpoint of improving the curing speed during moisture curing.
Examples of the moisture curing accelerator include a compound having a morpholine skeleton, a compound having a piperidine skeleton, and a compound having a piperazine skeleton.
上記粘着剤組成物は、粘着付与剤を含有することが好ましい。
上記粘着付与剤としては、例えば、ロジン系樹脂、テルペン系樹脂等が挙げられる。 The pressure-sensitive adhesive composition preferably contains a tackifier.
Examples of the tackifier include rosin-based resins and terpene-based resins.
上記ロジン系樹脂としては、例えば、ロジンジオール等が挙げられる。
上記ロジンジオールは、分子内にロジン骨格と水酸基とを各々２個有するロジン変性ジオールであれば特に限定されない。分子内にロジン成分を有するジオールは、ロジンポリオールと称されるが、これにはロジン成分を除く骨格がポリプロピレングリコール（ＰＰＧ）のようなポリエーテル型と、縮合系ポリエステルポリオール、ラクトン系ポリエステルポリオール、ポリカーボネートジオールのようなポリエステル型とがある。
上記ロジンジオールとしては、例えば、ロジンと多価アルコールとを反応させて得られるロジンエステル、ロジンとエポキシ化合物とを反応させて得られるエポキシ変性ロジンエステル、ロジン骨格を有するポリエーテル等の水酸基を有する変性ロジン等が挙げられる。これらは従来公知の方法によって製造することができる。 The rosin-based resin includes, for example, rosin diol.
The rosin diol is not particularly limited as long as it is a rosin-modified diol having two rosin skeletons and two hydroxyl groups in the molecule. Diols having a rosin component in the molecule are called rosin polyols, and these include polyether types such as polypropylene glycol (PPG) in which the skeleton excluding the rosin component is polyether, and polyester types such as condensation polyester polyols, lactone polyester polyols, and polycarbonate diols.
Examples of the rosin diol include rosin ester obtained by reacting rosin with a polyhydric alcohol, epoxy-modified rosin ester obtained by reacting rosin with an epoxy compound, and modified rosin having a hydroxyl group, such as polyether having a rosin skeleton, etc. These can be produced by conventionally known methods.
上記ロジン成分としては、例えば、アビエチン酸とその誘導体であるデヒドロアビエチン酸、ジヒドロアビエチン酸、テトラヒドロアビエチン酸、ジアビエチン酸、ネオアビエチン酸、レボピマル酸等のピマル酸型樹脂酸、これらを水素添加した水添ロジン、これらを不均化した不均化ロジン等が挙げられる。 The rosin component includes, for example, abietic acid and its derivatives, such as pimaric acid type resin acids as dehydroabietic acid, dihydroabietic acid, tetrahydroabietic acid, diabietic acid, neoabietic acid, and levopimaric acid, hydrogenated rosins obtained by hydrogenating these, and disproportionated rosins obtained by disproportionating these.
上記ロジン系樹脂のうち市販されているものとしては、例えば、パインクリスタルＤ－６０１１、パインクリスタルＫＥ－６１５－３、パインクリスタルＫＲ－６１４、パインクリスタルＫＥ－１００、パインクリスタルＫＥ－３１１、パインクリスタルＫＥ－３５９、パインクリスタルＫＥ－６０４、パインクリスタルＤ－６２５０（いずれも荒川化学工業社製）等が挙げられる。 Commercially available examples of the above rosin-based resins include Pine Crystal D-6011, Pine Crystal KE-615-3, Pine Crystal KR-614, Pine Crystal KE-100, Pine Crystal KE-311, Pine Crystal KE-359, Pine Crystal KE-604, and Pine Crystal D-6250 (all manufactured by Arakawa Chemical Industries Co., Ltd.).
上記テルペン系樹脂としては、例えば、テルペンフェノール系樹脂等が挙げられる。
上記テルペンフェノール系樹脂とは、松ヤニやオレンジの皮等の天然物から得られる精油成分であるテルペン系樹脂とフェノールとの共重合体であって、当該共重合体の少なくとも一部水素化した部分水添テルペンフェノール系樹脂又は完全に水素化した完全水添テルペンフェノール系樹脂も含まれる。
ここで、完全水添テルペンフェノール系樹脂は、テルペンフェノール系樹脂を、実質的に完全に水添することにより得られるテルペン系樹脂であり、部分水添テルペンフェノール系樹脂は、テルペンフェノール系樹脂を部分的に水添することにより得られるテルペン系樹脂である。そして、テルペンフェノール系樹脂は、テルペン由来の二重結合とフェノール類由来の芳香族環二重結合とを有している。従って、完全水添テルペンフェノール系樹脂とは、テルペン部位及びフェノール部位の両方の部位が、完全に、又は、ほとんど水添された樹脂を意味し、部分水添テルペンフェノール系樹脂とは、それらの部位の水添程度が完全でなく、部分的である樹脂を意味する。上記水添する方法や反応形式としては、特に限定されるものではない。
上記テルペンフェノール系樹脂のうち市販されているものとしては、例えば、ヤスハラケミカル社製のＹＳポリスターＮＨ（完全水添テルペンフェノール系樹脂）等が挙げられる。 Examples of the terpene resin include terpene phenol resins.
The terpene phenol resin is a copolymer of phenol and a terpene resin, which is an essential oil component obtained from natural products such as rosin and orange peel, and also includes partially hydrogenated terpene phenol resins in which at least a portion of the copolymer is hydrogenated, and fully hydrogenated terpene phenol resins in which the copolymer is completely hydrogenated.
Here, the fully hydrogenated terpene phenolic resin is a terpene resin obtained by substantially completely hydrogenating a terpene phenolic resin, and the partially hydrogenated terpene phenolic resin is a terpene resin obtained by partially hydrogenating a terpene phenolic resin. The terpene phenolic resin has a double bond derived from a terpene and an aromatic ring double bond derived from a phenol. Therefore, the fully hydrogenated terpene phenolic resin means a resin in which both the terpene portion and the phenol portion are completely or almost hydrogenated, and the partially hydrogenated terpene phenolic resin means a resin in which the degree of hydrogenation of these portions is not complete but partial. The hydrogenation method and reaction form are not particularly limited.
Among the above terpene phenol-based resins, examples of commercially available ones include YS Polystar NH (fully hydrogenated terpene phenol-based resin) manufactured by Yasuhara Chemical Co., Ltd.
上記粘着剤組成物１００質量部中における上記粘着付与剤の含有量の好ましい下限は５質量部、好ましい上限は５０質量部である。上記粘着付与剤の含有量がこの範囲であることにより、得られる粘着シートが各種基材への密着性により優れるものとなる。上記粘着付与剤の含有量のより好ましい下限は１５質量部であり、より好ましい上限は３５質量部である。 The preferred lower limit of the content of the tackifier in 100 parts by mass of the adhesive composition is 5 parts by mass, and the preferred upper limit is 50 parts by mass. When the content of the tackifier is within this range, the resulting adhesive sheet has better adhesion to various substrates. A more preferred lower limit of the content of the tackifier is 15 parts by mass, and a more preferred upper limit is 35 parts by mass.
上記粘着剤組成物は、可塑剤を含有してもよい。
上記可塑剤としては、例えば、有機酸エステル、有機リン酸エステル、有機亜リン酸エステル等が挙げられる。 The pressure-sensitive adhesive composition may contain a plasticizer.
Examples of the plasticizer include organic acid esters, organic phosphates, and organic phosphites.
上記有機酸エステルとしては、例えば、一塩基性有機酸エステル、多塩基性有機酸エステル等が挙げられる。
上記一塩基性有機酸エステルとしては、例えば、酪酸、イソ酪酸、カプロン酸、２－エチル酪酸、ヘプチル酸、ｎ－オクチル酸、２－エチルヘキシル酸、ペラルゴン酸（ｎ－ノニル酸）、デシル酸等の一塩基性有機酸と、トリエチレングリコール、テトラエチレングリコール、トリプロピレングリコール等のグリコールとの反応によって得られたグリコールエステル等が挙げられる。
上記多塩基性有機酸エステルとしては、例えば、アジピン酸、セバシン酸、アゼライン酸等の多塩基性有機酸と、炭素数４～８の直鎖又は分岐構造を有するアルコールとの反応によって得られたエステル化合物等が挙げられる。 Examples of the organic acid ester include monobasic organic acid esters and polybasic organic acid esters.
Examples of the monobasic organic acid ester include glycol esters obtained by reacting a monobasic organic acid such as butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptyl acid, n-octylic acid, 2-ethylhexyl acid, pelargonic acid (n-nonylic acid), or decylic acid with a glycol such as triethylene glycol, tetraethylene glycol, or tripropylene glycol.
Examples of the polybasic organic acid ester include ester compounds obtained by reacting a polybasic organic acid such as adipic acid, sebacic acid, or azelaic acid with an alcohol having a linear or branched structure having 4 to 8 carbon atoms.
上記有機酸エステルは、具体的には例えば、トリエチレングリコール－ジ－２－エチルブチレート（３ＧＨ）、トリエチレングリコール－ジ－２－エチルヘキサノエート（３ＧＯ）、トリエチレングリコールジカプリレート、トリエチレングリコールジ－ｎ－オクタノエート、トリエチレングリコール－ジ－ｎ－ヘプタノエート（３Ｇ７）等が挙げられる。また、テトラエチレングリコール－ジ－ｎ－ヘプタノエート（４Ｇ７）、テトラエチレングリコール－ジ－２－エチルヘキサノエート、ジブチルセバケート、ジオクチルアゼレート、ジブチルカルビトールアジペート、エチレングリコールジ－２－エチルブチレート、１，３－プロピレングリコールジ－２－エチルブチレート等が挙げられる。更に、１，４－ブチレングリコールジ－２－エチルブチレート、ジエチレングリコール－ジ－２－エチルブチレート、ジエチレングリコール－ジ－２－エチルヘキサノエート、ジプロピレングリコールジ－２－エチルブチレート等が挙げられる。また、トリエチレングリコールジ－２－エチルペンタノエート、テトラエチレングリコール－ジ－２－エチルブチレート（４ＧＨ）、ジエチレングリコールジカプリエート、ジヘキシルアジペート（ＤＨＡ）、ジオクチルアジペート、ヘキシルシクロヘキシルアジペート、ジイソノニルアジペート、ヘプチルノニルアジペート等が挙げられる。その他、油変性セバシン酸アルキド、リン酸エステルとアジピン酸エステルとの混合物、炭素数４～９のアルキルアルコール及び炭素数４～９の環状アルコールから作製された混合型アジピン酸エステル等が挙げられる。 Specific examples of the organic acid esters include triethylene glycol di-2-ethylbutyrate (3GH), triethylene glycol di-2-ethylhexanoate (3GO), triethylene glycol dicaprylate, triethylene glycol di-n-octanoate, and triethylene glycol di-n-heptanoate (3G7). In addition, tetraethylene glycol di-n-heptanoate (4G7), tetraethylene glycol di-2-ethylhexanoate, dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate, ethylene glycol di-2-ethylbutyrate, and 1,3-propylene glycol di-2-ethylbutyrate. In addition, 1,4-butylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylhexanoate, and dipropylene glycol di-2-ethylbutyrate are also included. Other examples include triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate (4GH), diethylene glycol dicapryate, dihexyl adipate (DHA), dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, etc. Other examples include oil-modified sebacic acid alkyd, a mixture of a phosphate ester and an adipate ester, and a mixed adipate ester made from an alkyl alcohol having 4 to 9 carbon atoms and a cyclic alcohol having 4 to 9 carbon atoms.
上記有機リン酸エステル又は有機亜リン酸エステルとしては、リン酸又は亜リン酸とアルコールとの縮合反応により得られる化合物が挙げられる。なかでも、炭素数１～１２のアルコールと、リン酸又は亜リン酸との縮合反応により得られる化合物が好適である。
上記炭素数１～１２のアルコールとしては、例えば、メタノール、エタノール、ブタノール、ヘキサノール、２－エチルブタノール、ヘプタノール、オクタノール、２－エチルヘキサノール、デカノール、ドデカノール、ブトキシエタノール、ブトキシエトキシエタノール、ベンジルアルコール等が挙げられる。
上記有機リン酸エステル又は有機亜リン酸エステルとしては、例えば、リン酸トリメチル、リン酸トリエチル、リン酸トリプロピル、リン酸トリブチル、リン酸トリ（２－エチルヘキシル）、リン酸トリ（ブトキシエチル）、亜リン酸トリ（２－エチルヘキシル）、イソデシルフェニルホスフェート、トリイソプロピルホスフェート等が挙げられる。 The organic phosphate or organic phosphite may be a compound obtained by a condensation reaction between phosphoric acid or phosphorous acid and an alcohol. Among them, a compound obtained by a condensation reaction between an alcohol having 1 to 12 carbon atoms and phosphoric acid or phosphorous acid is preferable.
Examples of the alcohol having 1 to 12 carbon atoms include methanol, ethanol, butanol, hexanol, 2-ethylbutanol, heptanol, octanol, 2-ethylhexanol, decanol, dodecanol, butoxyethanol, butoxyethoxyethanol, and benzyl alcohol.
Examples of the organic phosphate ester or organic phosphite ester include trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tri(2-ethylhexyl) phosphate, tri(butoxyethyl) phosphate, tri(2-ethylhexyl) phosphite, isodecylphenyl phosphate, and triisopropyl phosphate.
上記粘着剤組成物は、消泡剤を含有してもよい。
上記消泡剤としては、例えば、シリコーン系消泡剤、アクリルポリマー系消泡剤、ビニルエーテルポリマー系消泡剤、オレフィンポリマー系消泡剤等が挙げられる。 The pressure-sensitive adhesive composition may contain a defoaming agent.
Examples of the defoaming agent include silicone-based defoaming agents, acrylic polymer-based defoaming agents, vinyl ether polymer-based defoaming agents, and olefin polymer-based defoaming agents.
上記粘着剤組成物は、本発明の目的を阻害しない範囲で、更に、架橋剤、粘度調整剤、シランカップリング剤、増感剤、熱硬化剤、硬化遅延剤、酸化防止剤、貯蔵安定化剤、分散剤、充填剤等の公知の各種添加剤を含有してもよい。
また、上記粘着剤組成物は、紫外線反応性の低下を防止する観点から、有機溶剤を実質的に含まないことが好ましく、具体的には、上記粘着剤組成物１００質量中における有機溶剤の含有量が１．５質量部以下であることが好ましい。 The pressure-sensitive adhesive composition may further contain various known additives such as a crosslinking agent, a viscosity modifier, a silane coupling agent, a sensitizer, a heat curing agent, a cure retarder, an antioxidant, a storage stabilizer, a dispersant, and a filler, within the scope of not impairing the object of the present invention.
In addition, from the viewpoint of preventing a decrease in ultraviolet reactivity, it is preferable that the pressure-sensitive adhesive composition is substantially free of organic solvents, and specifically, it is preferable that the content of the organic solvent per 100 mass of the pressure-sensitive adhesive composition is 1.5 parts by mass or less.
上記粘着剤組成物を調製する方法としては、例えば、混合機を用いて、上記窒素含有化合物と、上記（メタ）アクリルモノマーと、上記光重合開始剤と、熱可塑性樹脂や必要に応じて添加する添加剤等とを混合する方法等が挙げられる。上記混合機としては、例えば、ホモディスパー、ホモミキサー、万能ミキサー、プラネタリーミキサー、ニーダー、３本ロール等が挙げられる。 The method for preparing the pressure-sensitive adhesive composition includes, for example, a method in which the nitrogen-containing compound, the (meth)acrylic monomer, the photopolymerization initiator, the thermoplastic resin, and additives added as necessary are mixed using a mixer. Examples of the mixer include a homodisper, a homomixer, a universal mixer, a planetary mixer, a kneader, and a three-roll mixer.
上記粘着剤組成物の２５℃における粘度の好ましい下限は５ｍＰａ・ｓ、好ましい上限は２５万ｍＰａ・ｓである。上記粘度がこの範囲であることにより、上記粘着剤組成物は、印刷用により好適なものとなる。上記粘度のより好ましい下限は１００ｍＰａ・ｓ、より好ましい上限は１５万ｍＰａ・ｓである。
なお、上記粘度は、例えば、Ｅ型粘度計としてＶＩＳＣＯＭＥＴＥＲ　ＴＶ－２２（東機産業社製）を用い、粘着剤組成物の粘度領域に応じて適切なコーンプレートを用い、２５℃、１０ｒｐｍの条件にて測定することができる。 The pressure-sensitive adhesive composition has a viscosity at 25° C. of preferably 5 mPa·s at the lower limit and 250,000 mPa·s at the upper limit. By setting the viscosity within this range, the pressure-sensitive adhesive composition is more suitable for printing. The more preferred lower limit of the viscosity is 100 mPa·s, and the more preferred upper limit is 150,000 mPa·s.
The viscosity can be measured, for example, using a VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) as an E-type viscometer and using an appropriate cone plate depending on the viscosity range of the pressure-sensitive adhesive composition, under conditions of 25° C. and 10 rpm.
本発明の粘着シートは、上記粘着剤組成物に紫外線を照射して硬化させることにより形成される。本発明の粘着シートは、基材（セパレータ）上に形成され、被着体に転写可能なものであってもよいし、被着体上に直に形成されてもよい。本発明の粘着シートが被着体上に直に形成される場合、貼り合わせの回数を最低限にすることができ、かつ、貼り合わせ時に界面に気泡が入ることを防止できる。一方、本発明の粘着シートが基材（セパレータ）上に形成される場合、粘着シートが転写によって被着体上に配置されるので、施工上の制約が少ないという利点がある。 The adhesive sheet of the present invention is formed by irradiating the adhesive composition with ultraviolet light to cure it. The adhesive sheet of the present invention may be formed on a substrate (separator) and transferable to an adherend, or may be formed directly on an adherend. When the adhesive sheet of the present invention is formed directly on an adherend, the number of times of lamination can be minimized and air bubbles can be prevented from being introduced at the interface during lamination. On the other hand, when the adhesive sheet of the present invention is formed on a substrate (separator), the adhesive sheet is placed on the adherend by transfer, which has the advantage of fewer constraints on application.
本発明の粘着シートの厚さは、３０μｍ以上であることが好ましく、５０μｍ以上であることがより好ましい。上記粘着層の厚さが３０μｍ以上であることにより、充分な密着性が得られる。また、電子機器の薄型化に対応する観点から、上記粘着層の厚さは、１０００μｍ以下であることが好ましく、５００μｍ以下であることがより好ましい。 The thickness of the adhesive sheet of the present invention is preferably 30 μm or more, and more preferably 50 μm or more. By having a thickness of the adhesive layer of 30 μm or more, sufficient adhesion can be obtained. Furthermore, from the viewpoint of responding to the trend toward thinner electronic devices, the thickness of the adhesive layer is preferably 1000 μm or less, and more preferably 500 μm or less.
第一の被着体又はセパレータ上に、上記粘着剤組成物を塗工し、露光することにより本発明の粘着シートを形成する工程、及び、上記粘着層上に第二の被着体を貼付する工程を有し、上記粘着剤組成物を塗工する方法は、インクジェット印刷、スクリーン印刷、スプレーコート、スピンコート、グラビアオフセット、又は、反転オフセット印刷であり、上記粘着剤組成物が上記第一の被着体上に部分的に塗工される積層体の製造方法もまた、本発明の１つである。上記セパレータ上に本発明の粘着シートを形成する場合、得られた粘着シートを第一の被着体上に転写する工程が行われた後、上記粘着層上に第二の被着体を貼付する工程が行われる。 The method includes a step of forming the adhesive sheet of the present invention by applying the adhesive composition to a first adherend or a separator and exposing the composition to light, and a step of attaching a second adherend to the adhesive layer, and the method of applying the adhesive composition is inkjet printing, screen printing, spray coating, spin coating, gravure offset, or reverse offset printing. The present invention also includes a method of manufacturing a laminate in which the adhesive composition is partially applied to the first adherend. When the adhesive sheet of the present invention is formed on the separator, a step of transferring the obtained adhesive sheet to the first adherend is performed, and then a step of attaching a second adherend to the adhesive layer is performed.
上記第一の被着体及び上記第二の被着体の材質としては、例えば、ステンレス、アルミニウム等の金属、樹脂等が挙げられる。 Examples of the material for the first adherend and the second adherend include metals such as stainless steel and aluminum, resins, etc.
本発明によれば、紫外線硬化により得られるものでありながら耐衝撃性に優れる粘着シートを提供することができる。また、本発明によれば、該粘着シートを有する積層体の製造方法を提供することができる。 According to the present invention, it is possible to provide an adhesive sheet that is obtained by UV curing and has excellent impact resistance. In addition, according to the present invention, it is possible to provide a method for producing a laminate having the adhesive sheet.
図１は、粘弾性チャートにおける、Ｇｇｔｅｍｐ、ＧＦ１ｔｅｍｐ、ＧＦ２ｔｅｍｐ、及び、ＧＦ２ｔａｎδの関係を示す模式図である。FIG. 1 is a schematic diagram showing the relationship between Ggtemp, GF1temp, GF2temp, and GF2tan δ in a viscoelasticity chart.
以下に実施例を掲げて本発明を更に詳しく説明するが、本発明はこれら実施例のみに限定されない。 The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.
（実施例１～１８、比較例１～７）
（１）粘着剤組成物の調製
表１～３に記載された配合比に従い、架橋剤を除く各材料を遊星式撹拌機（シンキー社製、「あわとり練太郎」）にて混合して粘着剤組成物を得た。
表中に略号で記載した材料の詳細は、以下の通りである。
（窒素含有化合物）
・ＣＨＭＩ：Ｎ－シクロヘキシルマレイミド（日本触媒社製）
・ＮＶＣ：Ｎ－ビニル－ε－カプロラクタム（東京化成工業社製）
（（メタ）アクリルモノマー）
・ＣＢＡ：エチルカルビトールアクリレート（大阪有機化学工業社製、「ビスコート＃１９０」、エーテル結合含有）
・ＭＥＤＯＬ－１０：（２－メチル－２－エチル－１，３－ジオキソラン－４－イル）メチルアクリレート（大阪有機化学工業社製、エーテル結合含有）
・ＩＤＡＡ：イソデシルアクリレート（大阪有機化学工業社製）
・ＩＢＯＡ：イソボルニルアクリレート（日本触媒社製）
・ビスコート＃２１６：アクリル酸－２－ブチルカルバモイルオキシエチルエステル（大阪有機化学工業社製、アミド結合含有）
・４－ＨＢＡ：４－ヒドロキシブチルアクリレート（三菱ケミカル社製）
・ＵＡ－１６０ＴＭ：ポリエーテル系多官能ウレタンアクリレート（新中村化学工業社製）
・ＡＢ－６：片末端にアクリロイル基を有するアクリル系化合物（東亞合成社製）
・ＨＰＶＭ－Ｌ１２５３：片末端にメタクリロイル基を有するオレフィン系化合物（クレイトンポリマージャパン社製）
（光重合開始剤）
・Ｏｍｎｉｒａｄ　１８４：１－ヒドロキシシクロヘキシルフェニルケトン（ＩＧＭ　Ｒｅｓｉｎｓ社製、開裂型光重合開始剤）
・Ｏｍｎｉｒａｄ　ＴＰＯ：２，４，６－トリメチルベンゾイルジフェニルホスフィンオキサイド（ＩＧＭ　Ｒｅｓｉｎｓ社製、開裂型光重合開始剤）
・Ｅｓａｃｕｒｅ　ＴＺＴ：２，４，６－トリメチルベンゾフェノンと４－メチルベンゾフェノンとの混合物（ＩＧＭ　Ｒｅｓｉｎｓ社製、水素引き抜き型光重合開始剤）
・Ｅｓａｃｕｒｅ　３６４４：３－ケトクマリン（ＩＧＭ　Ｒｅｓｉｎｓ社製、水素引き抜き型光重合開始剤）
・Ｏｍｎｉｐｏｌ　ＴＰ：エチル（２，４，６－トリメチルベンゾイル）－フェニルフォスフィネートの重合体（ＩＧＭ　Ｒｅｓｉｎｓ社製、ポリマー型光重合開始剤）
・Ｏｍｎｉｐｏｌ　９１０：ポリエチレングリコールジ（β－４（４－（２－ジメチルアミノ－２－ベンジル）ブタノイルフェニル）ピペラジン）プロピオネート（ＩＧＭ　Ｒｅｓｉｎｓ社製、ポリマー型光重合開始剤）
・Ｏｍｎｉｐｏｌ　２７０２：ビス（ベンゾフェノン－２－カルボン酸）ポリエチレングリコールエステル（ＩＧＭ　Ｒｅｓｉｎｓ社製、ポリマー型光重合開始剤）
（熱可塑性樹脂）
・ＬＡ２１４０：アクリル系ブロック共重合体（クラレ社製）
・ＬＫ９３３３：アクリル系ブロック共重合体（クラレ社製）
・アクリルポリマーＡ：後述する方法により合成
・アクリルポリマーＢ：後述する方法により合成
（粘着付与剤）
・ＫＥ－３５９：ロジン系樹脂（荒川化学工業社製）
（架橋剤）
・ミリオネートＭＲ：ポリメリックＭＤＩ（東ソー社製）
・コロネートＬ：トルエンジイソシアネート（東ソー社製）
（アミン化合物）
・アデカスタブＬＡ－５２：テトラキス（１，２，２，６，６－ペンタメチル－４－ピペリジル）ブタン－１，２，３，４－テトラカルボキシレート
・Ｅｖｅｒｓｏｒｂ　９３：セバシン酸ビス（１，２，２，６，６－ペンタメチル－４－ピペリジル）とデカン二酸１－メチル１０－（１，２，２，６，６－ペンタメチル－４－ピペリジニル）との混合物
（消泡剤）
・ＫＳ－６６：シリコーンオイルに微粉末シリカを配合したオイルコンパウンド型消泡剤（信越化学工業社製） (Examples 1 to 18, Comparative Examples 1 to 7)
(1) Preparation of Pressure-Sensitive Adhesive Compositions According to the compounding ratios shown in Tables 1 to 3, the materials except for the crosslinking agent were mixed in a planetary mixer (Thinky Corporation, "Awatori Rentaro") to obtain pressure-sensitive adhesive compositions.
Details of the materials indicated by abbreviations in the table are as follows.
(Nitrogen-containing compounds)
CHMI: N-cyclohexylmaleimide (manufactured by Nippon Shokubai Co., Ltd.)
NVC: N-vinyl-ε-caprolactam (Tokyo Chemical Industry Co., Ltd.)
((Meth)acrylic monomer)
CBA: Ethyl carbitol acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., "Viscoat #190", containing ether bonds)
MEDOL-10: (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., containing an ether bond)
IDAA: Isodecyl acrylate (Osaka Organic Chemical Industry Co., Ltd.)
IBOA: Isobornyl acrylate (manufactured by Nippon Shokubai Co., Ltd.)
Viscoat #216: acrylic acid-2-butylcarbamoyloxyethyl ester (Osaka Organic Chemical Industry, Inc., containing amide bond)
4-HBA: 4-hydroxybutyl acrylate (manufactured by Mitsubishi Chemical Corporation)
UA-160TM: Polyether-based multifunctional urethane acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)
AB-6: Acrylic compound having an acryloyl group at one end (manufactured by Toagosei Co., Ltd.)
HPVM-L1253: an olefin-based compound having a methacryloyl group at one end (manufactured by Kraton Polymer Japan)
(Photopolymerization initiator)
Omnirad 184: 1-hydroxycyclohexyl phenyl ketone (IGM Resins, cleavage-type photopolymerization initiator)
Omnirad TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (manufactured by IGM Resins, cleavage-type photopolymerization initiator)
Esacure TZT: a mixture of 2,4,6-trimethylbenzophenone and 4-methylbenzophenone (manufactured by IGM Resins, a hydrogen abstraction type photopolymerization initiator)
Esacure 3644: 3-ketocoumarin (manufactured by IGM Resins, hydrogen abstraction type photopolymerization initiator)
Omnipol TP: Ethyl (2,4,6-trimethylbenzoyl)-phenyl phosphinate polymer (manufactured by IGM Resins, polymeric photopolymerization initiator)
Omnipol 910: polyethylene glycol di(β-4(4-(2-dimethylamino-2-benzyl)butanoylphenyl)piperazine)propionate (manufactured by IGM Resins, polymer type photopolymerization initiator)
Omnipol 2702: bis(benzophenone-2-carboxylic acid) polyethylene glycol ester (manufactured by IGM Resins, polymeric photopolymerization initiator)
(Thermoplastic resin)
LA2140: Acrylic block copolymer (manufactured by Kuraray)
LK9333: Acrylic block copolymer (manufactured by Kuraray)
Acrylic polymer A: Synthesized by the method described below Acrylic polymer B: Synthesized by the method described below (tackifier)
KE-359: Rosin resin (manufactured by Arakawa Chemical Industries, Ltd.)
(Crosslinking Agent)
Millionate MR: Polymeric MDI (manufactured by Tosoh Corporation)
・Coronate L: Toluene diisocyanate (manufactured by Tosoh Corporation)
(Amine Compound)
ADK STAB LA-52: Tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate Eversorb 93: Mixture of bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacic acid and 1-methyl 10-(1,2,2,6,6-pentamethyl-4-piperidinyl)decanedioate (defoaming agent)
KS-66: An oil compound type defoamer made by mixing silicon oil with fine silica powder (manufactured by Shin-Etsu Chemical Co., Ltd.)
（アクリルポリマーＡ）
温度計、撹拌機、窒素導入管、冷却管を備えた２Ｌ容のセパラブルフラスコに重合溶媒として酢酸エチル５０質量部を仕込み、加熱により還流させた後、重合開始剤として２，２’－アゾビス（イソブチロニトリル）０．４質量部を投入した。ブチルアクリレート７７質量部、２－エチルヘキシルアクリレート１７質量部、２－ヒドロキシエチルアクリレート０．０１質量部、アクリル酸６質量部、及び、連鎖移動剤として１－チオグリセロール０．１５質量部を混合し、滴下漏斗を用いてセパラブルフラスコ内に２時間かけて滴下した。滴下を開始した時間を重合開始時間とし、重合開始から６０℃で６時間重合反応を行うことによりアクリルポリマー溶液を得た。得られた溶液を加熱して乾燥させ、アクリルポリマーＡを得た。 (Acrylic Polymer A)
A 2L separable flask equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a cooling tube was charged with 50 parts by mass of ethyl acetate as a polymerization solvent, and after heating to reflux, 0.4 parts by mass of 2,2'-azobis(isobutyronitrile) was added as a polymerization initiator. 77 parts by mass of butyl acrylate, 17 parts by mass of 2-ethylhexyl acrylate, 0.01 parts by mass of 2-hydroxyethyl acrylate, 6 parts by mass of acrylic acid, and 0.15 parts by mass of 1-thioglycerol as a chain transfer agent were mixed and dropped into the separable flask over 2 hours using a dropping funnel. The time when the dropping started was the polymerization initiation time, and the polymerization reaction was carried out at 60 ° C. for 6 hours from the start of polymerization to obtain an acrylic polymer solution. The obtained solution was heated and dried to obtain acrylic polymer A.
（アクリルポリマーＢ）
温度計、撹拌機、窒素導入管、冷却管を備えた２Ｌ容のセパラブルフラスコに重合溶媒として酢酸エチル８０質量部を仕込み、加熱により還流させた後、重合開始剤として２，２’－アゾビス（イソブチロニトリル）０．１質量部を投入した。２－エチルヘキシルアクリレート１８質量部、ｎ－ヘプチルアクリレート７９質量部、２－ヒドロキシエチルアクリレート０．２質量部、アクリル酸３質量部、及び、連鎖移動剤としてドデカンチオール０．０５質量部を混合し、滴下漏斗を用いてセパラブルフラスコ内に２時間かけて滴下した。滴下を開始した時間を重合開始時間とし、重合開始から８０℃で６時間重合反応を行うことによりアクリルポリマー溶液を得た。得られた溶液を加熱して乾燥させ、アクリルポリマーＢを得た。 (Acrylic Polymer B)
A 2L separable flask equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a cooling tube was charged with 80 parts by mass of ethyl acetate as a polymerization solvent, and the mixture was refluxed by heating, and then 0.1 parts by mass of 2,2'-azobis(isobutyronitrile) was added as a polymerization initiator. 18 parts by mass of 2-ethylhexyl acrylate, 79 parts by mass of n-heptyl acrylate, 0.2 parts by mass of 2-hydroxyethyl acrylate, 3 parts by mass of acrylic acid, and 0.05 parts by mass of dodecanethiol as a chain transfer agent were mixed and dropped into the separable flask over 2 hours using a dropping funnel. The time when the dropping started was the polymerization initiation time, and the polymerization reaction was carried out at 80 ° C. for 6 hours from the start of polymerization to obtain an acrylic polymer solution. The obtained solution was heated and dried to obtain an acrylic polymer B.
（２）粘着シートの作製
（実施例１～４、６、７、９～１８、比較例２）
得られた粘着剤組成物を、離型ＰＥＴフィルム（ニッパ社製、「１－Ｃ」、厚さ３８μｍ）の内側処理面上に厚み１００μｍとなるようにアプリケーターにて塗工した。なお、実施例２、３、７、９、１２、１３、１６、１７にかかる粘着剤組成物については、塗工前に粘着剤組成物に表１～３に記載された含有量となるように架橋剤を混合した。次いで、塗工上面を封止せずに大気環境下で、バッチ式ＵＶ　ＬＥＤ硬化装置を用いて、波長３６５ｎｍ、照度２０ｍＷ／ｃｍ２の紫外線、及び、波長４０５ｎｍ、照度４０ｍＷ／ｃｍ２の光を、合計の照射量が９００ｍＪ／ｃｍ２となるように同時照射することにより、粘着剤組成物を硬化させて粘着シートを得た。上記バッチ式ＵＶ　ＬＥＤ硬化装置としては、Ｍ　ＵＶＢＡ（アイテック社製）を用いた。その後、片面離型処理されたＰＥＴシート（ニッパ社製「１－Ｅ」、厚さ５０μｍ）にて粘着シートの大気面を封止し、粘着シートを含む積層体を得た。
なお、本方法で得られた粘着シートは、粘着剤組成物を加熱せずに紫外線照射のみを行って形成したものであるため、ＣＯ２排出量を削減する効果に優れるものと言える。また、本方法において、加熱を行って作製されたアクリルポリマーＡ、Ｂを用いずに得られた粘着シートは、ＣＯ２排出量を削減する効果により優れるものと言える。 (2) Preparation of Adhesive Sheets (Examples 1 to 4, 6, 7, 9 to 18, Comparative Example 2)
The obtained adhesive composition was applied to the inner treated surface of a release PET film (manufactured by Nippa Corporation, "1-C", thickness 38 μm) with an applicator to a thickness of 100 μm. For the adhesive compositions of Examples 2, 3, 7, 9, 12, 13, 16, and 17, a crosslinking agent was mixed into the adhesive composition before application so as to have the content shown in Tables 1 to 3. Next, the adhesive composition was cured by simultaneously irradiating ultraviolet light having a wavelength of 365 nm and an illuminance of 20 mW/cm 2 and light having a wavelength of 405 nm and an illuminance of 40 mW/cm 2 in an atmospheric environment without sealing the coated surface, using a batch-type UV LED curing device, so that the total irradiation amount was 900 mJ/cm 2. As the batch-type UV LED curing device, M UVBA (manufactured by ITEC Co., Ltd.) was used. Thereafter, the air side of the pressure-sensitive adhesive sheet was sealed with a PET sheet (Nippa Corporation "1-E", thickness 50 μm) that had been release-treated on one side, to obtain a laminate including the pressure-sensitive adhesive sheet.
In addition, since the pressure-sensitive adhesive sheet obtained by this method is formed by only irradiating the pressure-sensitive adhesive composition with ultraviolet light without heating it, it can be said to have an excellent effect of reducing CO2 emissions. In addition, in this method, the pressure-sensitive adhesive sheet obtained without using the acrylic polymers A and B produced by heating can be said to have an excellent effect of reducing CO2 emissions.
（実施例５、８、比較例１）
得られた粘着剤組成物を、離型ＰＥＴフィルム（ニッパ社製、「１－Ｃ」、厚さ３８μｍ）の内側処理面上に厚み１００μｍとなるようにアプリケーターにて塗工した。なお、実施例５、比較例１にかかる粘着剤組成物については、塗工前に粘着剤組成物に表１、３に記載された含有量となるように架橋剤を混合した。次いで、離型ＰＥＴフィルム（ニッパ社製「１－Ｅ」、厚さ５０μｍ）にて大気面を封止した。封止された状態でバッチ式ＵＶ　ＬＥＤ硬化装置を用いて、波長３６５ｎｍ、照度４ｍＷ／ｃｍ２の紫外線、及び、波長４０５ｎｍ、照度４ｍＷ／ｃｍ２の光を、合計の照射量が１５００ｍＪ／ｃｍ２となるように同時照射することにより、粘着剤組成物を硬化させて、粘着シートを含む積層体を得た。
なお、本方法で得られた粘着シートも、粘着剤組成物を加熱せずに紫外線照射のみを行って形成したものであるため、ＣＯ２排出量を削減する効果に優れるものと言える。また、本方法において、加熱を行って作製されたアクリルポリマーＡ、Ｂを用いずに得られた粘着シートは、ＣＯ２排出量を削減する効果により優れるものと言える。 (Examples 5 and 8, Comparative Example 1)
The obtained adhesive composition was applied to the inner treated surface of a release PET film (manufactured by Nippa Corporation, "1-C", thickness 38 μm) with an applicator to a thickness of 100 μm. For the adhesive compositions of Example 5 and Comparative Example 1, a crosslinking agent was mixed into the adhesive composition before application to the contents shown in Tables 1 and 3. Next, the air surface was sealed with a release PET film (manufactured by Nippa Corporation, "1-E", thickness 50 μm). In the sealed state, a batch-type UV LED curing device was used to simultaneously irradiate ultraviolet light with a wavelength of 365 nm and an illuminance of 4 mW/cm 2 and light with a wavelength of 405 nm and an illuminance of 4 mW/cm 2 to a total irradiation amount of 1500 mJ/cm 2 , thereby curing the adhesive composition and obtaining a laminate including an adhesive sheet.
In addition, the pressure-sensitive adhesive sheet obtained by this method is also formed by only irradiating the pressure-sensitive adhesive composition with ultraviolet light without heating it, and therefore can be said to have an excellent effect of reducing CO2 emissions. In addition, in this method, the pressure-sensitive adhesive sheet obtained without using the acrylic polymers A and B produced by heating can be said to have an excellent effect of reducing CO2 emissions.
（比較例３～７）
温度計、撹拌機、窒素導入管、冷却管を備えた２Ｌ容のセパラブルフラスコに重合溶媒として酢酸エチル７０質量部及びアセトン４０質量部を仕込み、加熱により還流させた後、重合開始剤として２，２’－アゾビス（イソブチロニトリル）０．０５質量部を投入した。次いで、得られた粘着剤組成物を、滴下漏斗を用いてセパラブルフラスコ内に２時間かけて滴下した。滴下を開始した時間を重合開始時間とし、重合開始から６０℃で６時間重合反応を行うことによりポリマー溶液を得た。
得られたポリマー溶液に表３に記載された含有量となるように架橋剤を混合した後、乾燥後の厚さが１００μｍとなるように離型ＰＥＴフィルム（ニッパ社製、「１－Ｃ」、厚さ３８μｍ）上にアプリケーターを用いて塗工し、粘着シートを得た。乾燥は、４０℃にて２０分、６０℃にて２０分、１１０℃にて１０分の順に行った。その後、片面離型処理されたＰＥＴシート（ニッパ社製「１－Ｅ」、厚さ５０μｍ）にて粘着シートの大気面を封止し、粘着シートを含む積層体を得た。
なお、本方法で得られた粘着シートは、粘着剤組成物を加熱して形成したものであるため、ＣＯ２排出量を削減する効果に劣るものと言える。 (Comparative Examples 3 to 7)
A 2 L separable flask equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a cooling tube was charged with 70 parts by mass of ethyl acetate and 40 parts by mass of acetone as a polymerization solvent, and the mixture was heated to reflux, and then 0.05 parts by mass of 2,2'-azobis(isobutyronitrile) was added as a polymerization initiator. The resulting pressure-sensitive adhesive composition was then dropped into the separable flask over a period of 2 hours using a dropping funnel. The time when the dropping started was defined as the polymerization initiation time, and a polymer solution was obtained by carrying out a polymerization reaction at 60°C for 6 hours from the start of polymerization.
The crosslinking agent was mixed into the obtained polymer solution in an amount shown in Table 3, and then the mixture was applied using an applicator onto a release PET film (manufactured by Nippa Corporation, "1-C", thickness 38 μm) so that the thickness after drying would be 100 μm, to obtain an adhesive sheet. Drying was performed in the order of 20 minutes at 40° C., 20 minutes at 60° C., and 10 minutes at 110° C. Then, the air side of the adhesive sheet was sealed with a PET sheet (manufactured by Nippa Corporation, "1-E", thickness 50 μm) that had been release-treated on one side, to obtain a laminate including the adhesive sheet.
It should be noted that the pressure-sensitive adhesive sheet obtained by this method is formed by heating the pressure-sensitive adhesive composition, and therefore is inferior in terms of the effect of reducing CO2 emissions.
（３）動的粘弾性測定
得られた粘着シートを含む積層体から両方の離型ＰＥＴフィルムを剥離し、以下の条件で粘着シートに対して動的粘弾性測定を行い、粘弾性チャートを得た。上記動的粘弾性測定装置としては、ＭＣＲ－７０２ｅ（アントンパール社製）等を用いた。得られた粘弾性チャートから、Ｇｇｔｅｍｐ、ＧＦ１ｔｅｍｐ、ＧｇｔｅｍｐとＧＦ１ｔｅｍｐとの温度差、ＧＦ２ｔｅｍｐ、ＧＦ２ｔａｎδ、ＧＥｔｅｍｐ、ＧＥｔａｎδ、及び、ｄｅｌｔａ　ｔａｎδを導出した。また、得られた粘弾性チャートから導出されるｔａｎδピーク温度をガラス転移温度（Ｔｇ）として求めた。結果を表１～３に示した。
＜条件＞
　せん断法：８ｍｍパラレルプレートを用いて、ツインドライブにて測定
　測定温度－７０℃～２００℃
　昇温速度：７℃／分
　周波数：１Ｈｚ
　５０℃から－７０℃まで１０℃／分で降温中、８Ｎで予備圧着させ、下記（３－１）～（３－６）の通りに低温から測定。
（３－１）ノーマルフォース２０Ｎにて歪０．００５％で昇温、トルク値が１５００μＮ・ｍ未満となるまでこの条件で測定。
（３－２）（３－１）の後、ノーマルフォース８Ｎにて歪０．０５％で昇温、トルク値が２００μＮ・ｍ未満となるまでこの条件で測定。
（３－３）（３－２）の後、ノーマルフォース３Ｎにて歪０．５％で昇温、トルク値が１５０μＮ・ｍ未満となるまでこの条件で測定。（３－３）のトルク値が１２０℃まで１５０μＮ・ｍ以上であった場合は、（３－４）に移行する。
（３－４）（３－３）の後、ノーマルフォース１．５Ｎにて歪２％で昇温、トルク値が１００μＮ・ｍ未満となるまでこの条件で測定。（３－４）のトルク値が１７０℃まで１００μＮ・ｍ以上だった場合は、（３－５）に移行する。
（３－５）（３－４）の後、ノーマルフォース１Ｎにて歪５％で昇温、トルク値が８０μＮ・ｍ未満となるまでこの条件で測定。（３－５）のトルク値が１９０℃まで８０μＮ・ｍ以上だった場合や厚みが３０μｍ未満になった場合は、（３－６）に移行する。
（３－６）（３－５）の後、ノーマルフォース１Ｎにて歪１０％で昇温、２００℃となるまでこの条件で測定。（３－６）の温度が２００℃になる前に厚みが２０μｍ未満になった際、測定を終了する。ここまで貯蔵弾性率が極小点を迎えない場合は、２００℃又は測定終了時の温度が上記ＧＥｔｅｍｐとなる。 (3) Dynamic Viscoelasticity Measurement Both release PET films were peeled off from the laminate containing the obtained adhesive sheet, and dynamic viscoelasticity measurement was performed on the adhesive sheet under the following conditions to obtain a viscoelasticity chart. As the dynamic viscoelasticity measuring device, MCR-702e (manufactured by Anton Paar) or the like was used. From the obtained viscoelasticity chart, Ggtemp, GF1temp, the temperature difference between Ggtemp and GF1temp, GF2temp, GF2tan δ, GEtemp, GEtan δ, and delta tan δ were derived. In addition, the tan δ peak temperature derived from the obtained viscoelasticity chart was determined as the glass transition temperature (Tg). The results are shown in Tables 1 to 3.
<Conditions>
Shear method: Measured with twin drive using 8 mm parallel plate Measurement temperature: -70℃ to 200℃
Heating rate: 7°C/min Frequency: 1Hz
While cooling from 50°C to -70°C at 10°C/min, pre-pressure is applied at 8N, and measurements are taken from the low temperature as described below in (3-1) to (3-6).
(3-1) The temperature is raised with a normal force of 20 N and a strain of 0.005%, and measurements are taken under these conditions until the torque value becomes less than 1500 μN·m.
(3-2) After (3-1), the temperature is increased with a normal force of 8 N and a strain of 0.05%, and measurements are taken under these conditions until the torque value becomes less than 200 μN·m.
(3-3) After (3-2), raise the temperature with a normal force of 3 N and a strain of 0.5%, and measure under these conditions until the torque value is less than 150 μN·m. If the torque value of (3-3) is 150 μN·m or more up to 120°C, proceed to (3-4).
(3-4) After (3-3), raise the temperature with a normal force of 1.5 N and a strain of 2%, and measure under these conditions until the torque value is less than 100 μN·m. If the torque value of (3-4) is 100 μN·m or more up to 170°C, proceed to (3-5).
(3-5) After (3-4), raise the temperature with a normal force of 1N and a strain of 5%, and measure under these conditions until the torque value is less than 80 μN·m. If the torque value of (3-5) is 80 μN·m or more up to 190°C or if the thickness is less than 30 μm, proceed to (3-6).
(3-6) After (3-5), the temperature is raised with a normal force of 1 N and a strain of 10%, and measurements are performed under these conditions until the temperature reaches 200° C. When the thickness becomes less than 20 μm before the temperature of (3-6) reaches 200° C., the measurement is terminated. If the storage modulus does not reach a minimum point up to this point, 200° C. or the temperature at the end of the measurement becomes the GEtemp.
＜評価＞
実施例及び比較例で得られた各粘着シートについて、以下の評価を行った。結果を表１～３に示した。 <Evaluation>
The pressure-sensitive adhesive sheets obtained in the Examples and Comparative Examples were evaluated as follows. The results are shown in Tables 1 to 3.
（１８０°ピール接着力）
得られた粘着シートを含む積層体を幅７５ｍｍ、長さ１２５ｍｍとなるように切り出した後、一方の離型ＰＥＴフィルムを剥離し、易接着性ポリエステルフィルム（東洋紡社製、「コスモシャイン　Ａ４１００」）の内側処理面に転写し、幅２５ｍｍ、長さ２００ｍｍ（被着面２５ｍｍ×１２５ｍｍ）となるようにカットし、積層フィルムを得た。その後、積層フィルムからもう一方の離型ＰＥＴフィルムを剥離し、露出させた面を幅８０ｍｍ、長さ１２５ｍｍ、厚さ１ｍｍのＳＵＳ　３０４－ＢＡ基板に貼り合わせ、２ｋｇローラーにて一往復させることで圧着し、試験片を得た。
得られた試験片を２５℃、５０％ＲＨの環境下で１日養生した後、万能試験機（エー・アンド・デイ社製、「テンシロン　ＲＴＩ－１３１０」）を用いて３００ｍｍ／ｍｉｎの速度で１８０°ピールを行うことにより、１８０°ピール接着力を測定した。 (180° peel adhesive strength)
The laminate including the obtained pressure-sensitive adhesive sheet was cut to a width of 75 mm and a length of 125 mm, and then one of the release PET films was peeled off and transferred to the inner treated surface of an easily adhesive polyester film (manufactured by Toyobo Co., Ltd., "Cosmoshine A4100"), and cut to a width of 25 mm and a length of 200 mm (adhering surface 25 mm x 125 mm) to obtain a laminated film. Thereafter, the other release PET film was peeled off from the laminated film, and the exposed surface was attached to a SUS 304-BA substrate having a width of 80 mm, a length of 125 mm, and a thickness of 1 mm, and pressure-bonded by moving it back and forth once with a 2 kg roller to obtain a test piece.
The obtained test piece was aged for one day in an environment of 25°C and 50% RH, and then 180° peel adhesion was measured by performing 180° peel at a speed of 300 mm/min using a universal testing machine (manufactured by A&D Co., Ltd., "Tensilon RTI-1310").
（耐衝撃性）
得られた粘着シートを含む積層体を２５ｍｍ×２５ｍｍに切り出した後、両方の離型ＰＥＴフィルムを剥離した。次いで、粘着シートを介して、中央に２０ｍｍ×２０ｍｍ×３ｍｍｔの穴が開いた４０ｍｍ×４０ｍｍ×３ｍｍｔのＳＵＳ基板と、２５ｍｍ×２５ｍｍ×３ｍｍｔのＳＵＳ基板とを貼り合わせ、積層体を得た。得られた積層体について、万能試験機（エー・アンド・デイ社製、「テンシロン　ＲＴＩ－１３１０」）を用いて６２Ｎにて圧着を行い、試験片を作製した。落錘式衝撃試験機（ＩＭＡＴＥＫ社製、「ＩＭ１Ｃ－１５型」）を用いて、１６Φ、総質量５ｋｇの落錘子にて５１ｍｍの高さから、自然落下により試験片の中央部をインパクトした。ｍｓ　ｖ．ｓ．　Ｎのスペクトルから、一つ目の山の面積（エネルギー量）を衝撃吸収率ΔＥ（Ｊ）として算出した。更に極大点をピークフォース（耐衝撃試験力（Ｎ））とした。以下の基準により、耐衝撃性を評価した。
◎：ΔＥが０．３４５Ｊを超えた場合、又は、ピークフォースが１．６０Ｎを超えた場合
○：ΔＥが０．１２０Ｊ以上０．３４５Ｊ以下であり、かつ、ピークフォースが１．２０Ｎ以上１．６０Ｎ以下であった場合
×：ΔＥが０．１２０Ｊ未満であり、かつ、ピークフォースが１．２０Ｎ以上１．６０Ｎ以下であるか、又は、ΔＥが０．１２０Ｊ以上０．３４５Ｊ以下であり、かつ、ピークフォースが１．２０Ｎ未満であった場合
××：ΔＥが０．１２０Ｊ未満であり、かつ、ピークフォースが１．２０Ｎ未満であった場合 (Impact resistance)
The laminate including the obtained adhesive sheet was cut into 25 mm x 25 mm, and both release PET films were peeled off. Next, a SUS substrate of 40 mm x 40 mm x 3 mmt with a hole of 20 mm x 20 mm x 3 mmt in the center and a SUS substrate of 25 mm x 25 mm x 3 mmt were bonded together through the adhesive sheet to obtain a laminate. The obtained laminate was pressed at 62 N using a universal testing machine (manufactured by A & D Co., Ltd., "Tensilon RTI-1310") to prepare a test piece. Using a drop weight impact tester (manufactured by IMATEK Co., Ltd., "IM1C-15 type"), a drop weight of 16 Φ and a total mass of 5 kg was dropped naturally from a height of 51 mm to impact the center of the test piece. From the spectrum of ms v.s.N, the area (amount of energy) of the first peak was calculated as the impact absorption rate ΔE (J). Furthermore, the maximum point was taken as the peak force (impact resistance test force (N)). The impact resistance was evaluated according to the following criteria.
◎: When ΔE exceeds 0.345 J or when the peak force exceeds 1.60 N ○: When ΔE is 0.120 J or more and 0.345 J or less and the peak force is 1.20 N or more and 1.60 N or less ×: When ΔE is less than 0.120 J and the peak force is 1.20 N or more and 1.60 N or less, or when ΔE is 0.120 J or more and 0.345 J or less and the peak force is less than 1.20 N XX: When ΔE is less than 0.120 J and the peak force is less than 1.20 N
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
本発明によれば、紫外線硬化により得られるものでありながら耐衝撃性に優れる粘着シートを提供することができる。また、本発明によれば、該粘着シートを有する積層体の製造方法を提供することができる。 According to the present invention, it is possible to provide an adhesive sheet that is obtained by UV curing and has excellent impact resistance. In addition, according to the present invention, it is possible to provide a method for producing a laminate having the adhesive sheet.

Claims (11)

  1. 光重合開始剤を含有する粘着剤組成物の硬化物である粘着シートであって、
    せん断法、測定温度－７０℃から２００℃、周波数１Ｈｚの条件で動的粘弾性測定を行うことにより得られる粘弾性チャートにおいて、
    最も低温側において損失弾性率が極大値となる温度をＧｇｔｅｍｐとし、該Ｇｇｔｅｍｐより高温の領域におけるｔａｎδが極大値となる温度のうち最も低温側にある温度をＴｇとした場合において、貯蔵弾性率と損失弾性率の比が最小となる温度のうちＴｇ以上から５０℃以下の温度領域において最も低温側にある温度をＧＦ１ｔｅｍｐとし、該ＧＦ１ｔｅｍｐより高温の領域において損失正接が極小値となる温度のうち最も低温側の温度をＧＦ２ｔｅｍｐとし、該ＧＦ２ｔｅｍｐにおける損失正接をＧＦ２ｔａｎδとしたとき、
    前記Ｇｇｔｅｍｐと前記ＧＦ１ｔｅｍｐとの温度差が２５．０℃以上であり、
    前記ＧＦ２ｔａｎδが０．３４以上である
    ことを特徴とする粘着シート。     A pressure-sensitive adhesive sheet which is a cured product of a pressure-sensitive adhesive composition containing a photopolymerization initiator,
    In a viscoelasticity chart obtained by performing dynamic viscoelasticity measurement under the conditions of a shear method, a measurement temperature of -70°C to 200°C, and a frequency of 1 Hz,
    When the temperature at which the loss modulus is maximum on the lowest temperature side is defined as Ggtemp, and the lowest temperature among the temperatures at which tan δ is maximum in the region higher than Ggtemp is defined as Tg, the lowest temperature in the temperature region from Tg to 50° C. among the temperatures at which the ratio of the storage modulus to the loss modulus is minimum is defined as GF1temp, and the lowest temperature among the temperatures at which the loss tangent is minimum in the region higher than GF1temp is defined as GF2temp, and the loss tangent at GF2temp is defined as GF2tan δ,
    The temperature difference between the Ggtemp and the GF1temp is 25.0°C or more;
    A pressure-sensitive adhesive sheet, characterized in that the GF2 tan δ is 0.34 or more.
  2. 前記粘弾性チャートにおいて、前記ＧＦ２ｔｅｍｐより高温の領域において貯蔵弾性率が極小値となる温度、又は、前記ＧＦ２ｔｅｍｐより高温の領域において貯蔵弾性率が極小値となる温度がない場合は２００℃をＧＥｔｅｍｐとし、該ＧＥｔｅｍｐにおける損失正接をＧＥｔａｎδとし、式（ＧＥｔａｎδ－ＧＦ２ｔａｎδ）／（ＧＥｔｅｍｐ－ＧＦ２ｔｅｍｐ）で求められる値をｄｅｌｔａ　ｔａｎδとしたとき、前記ｄｅｌｔａ　ｔａｎδが－０．００６以上である請求項１記載の粘着シート。 The adhesive sheet according to claim 1, in which GEtemp is the temperature at which the storage modulus is a minimum in the region higher than GF2temp in the viscoelasticity chart, or 200°C if there is no temperature at which the storage modulus is a minimum in the region higher than GF2temp, the loss tangent at said GEtemp is GEtanδ, and the value calculated by the formula (GEtanδ-GF2tanδ)/(GEtemp-GF2temp) is delta tanδ, said delta tanδ is -0.006 or more.
  3. 前記Ｇｇｔｅｍｐと前記ＧＦ１ｔｅｍｐとの温度差が５０．０℃以上である請求項１又は２記載の粘着シート。 The adhesive sheet according to claim 1 or 2, wherein the temperature difference between the Ggtemp and the GF1temp is 50.0°C or more.
  4. 前記ＧＦ２ｔａｎδが０．５０以上である請求項１、２又は３記載の粘着シート。 The adhesive sheet according to claim 1, 2 or 3, wherein the GF2 tan δ is 0.50 or more.
  5. ２５℃、５０％ＲＨの環境下で１日養生した後の前記粘着シートの２５℃におけるＳＵＳ基板に対する１８０°ピール接着力が６Ｎ／ｃｍ以上である請求項１、２、３又は４記載の粘着シート。 The adhesive sheet according to claim 1, 2, 3 or 4, which has a 180° peel adhesive strength of 6 N/cm or more at 25°C to a SUS substrate after being aged for one day in an environment of 25°C and 50% RH.
  6. 前記粘着剤組成物は、窒素含有化合物を含有する請求項１、２、３、４又は５記載の粘着シート。 The adhesive sheet according to claim 1, 2, 3, 4 or 5, wherein the adhesive composition contains a nitrogen-containing compound.
  7. 前記窒素含有化合物は、マレイミド誘導体を含む請求項６記載の粘着シート。 The adhesive sheet according to claim 6, wherein the nitrogen-containing compound includes a maleimide derivative.
  8. 前記粘着剤組成物は、水素引き抜き型光重合開始剤及びポリマー型光重合開始剤からなる群より選択される少なくとも１種を含む請求項１、２、３、４、５、６又は７記載の粘着シート。 The adhesive sheet according to claim 1, 2, 3, 4, 5, 6 or 7, wherein the adhesive composition contains at least one selected from the group consisting of a hydrogen abstraction type photopolymerization initiator and a polymer type photopolymerization initiator.
  9. 前記粘着剤組成物は、熱可塑性樹脂を含有する請求項１、２、３、４、５、６、７又は８記載の粘着シート。 The adhesive sheet according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein the adhesive composition contains a thermoplastic resin.
  10. 前記粘着剤組成物は、粘着付与剤を含有する請求項１、２、３、４、５、６、７、８又は９記載の粘着シート。 The adhesive sheet according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, wherein the adhesive composition contains a tackifier.
  11. 第一の被着体又はセパレータ上に、前記粘着剤組成物を塗工し、露光することにより請求項１、２、３、４、５、６、７、８、９又は１０記載の粘着シートを形成する工程、及び、前記粘着シート上に第二の被着体を貼付する工程を有し、
    前記粘着剤組成物を塗工する方法は、インクジェット印刷、スクリーン印刷、スプレーコート、スピンコート、グラビアオフセット、又は、反転オフセット印刷であり、前記粘着剤組成物が前記第一の被着体上に部分的に塗工される積層体の製造方法。     The method includes a step of forming the pressure-sensitive adhesive sheet according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 by applying the pressure-sensitive adhesive composition onto a first adherend or a separator and exposing the composition to light, and a step of attaching a second adherend onto the pressure-sensitive adhesive sheet,
    The method for applying the pressure-sensitive adhesive composition is inkjet printing, screen printing, spray coating, spin coating, gravure offset, or reverse offset printing, and the pressure-sensitive adhesive composition is applied partially onto the first adherend.
PCT/JP2023/042945 2022-12-01 2023-11-30 Pressure-sensitive adhesive sheet and method for producing laminate WO2024117223A1 (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013181088A (en) * 2012-03-01 2013-09-12 Mitsubishi Plastics Inc Transparent double-sided adhesive sheet for image-displaying device, and image-displaying device by using the same
US20140224577A1 (en) * 2011-08-23 2014-08-14 Avery Dennison Corporation Pressure Sensitive Adhesive Laminate for High Performance Noise and Vibration Damping Applications
WO2017154660A1 (en) * 2016-03-09 2017-09-14 株式会社カネカ Radically curable composition and cured product thereof
JP2018159066A (en) * 2017-03-22 2018-10-11 三菱ケミカル株式会社 Curable composition, curing sheet, and image display device
JP2019172916A (en) * 2018-03-29 2019-10-10 三菱ケミカル株式会社 Resin composition, compact, laminate, and picture display unit
JP2021088698A (en) * 2019-11-22 2021-06-10 三菱ケミカル株式会社 Adhesive sheet, layered sheet, flexible image display device member and flexible image display device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140224577A1 (en) * 2011-08-23 2014-08-14 Avery Dennison Corporation Pressure Sensitive Adhesive Laminate for High Performance Noise and Vibration Damping Applications
JP2013181088A (en) * 2012-03-01 2013-09-12 Mitsubishi Plastics Inc Transparent double-sided adhesive sheet for image-displaying device, and image-displaying device by using the same
WO2017154660A1 (en) * 2016-03-09 2017-09-14 株式会社カネカ Radically curable composition and cured product thereof
JP2018159066A (en) * 2017-03-22 2018-10-11 三菱ケミカル株式会社 Curable composition, curing sheet, and image display device
JP2019172916A (en) * 2018-03-29 2019-10-10 三菱ケミカル株式会社 Resin composition, compact, laminate, and picture display unit
JP2021088698A (en) * 2019-11-22 2021-06-10 三菱ケミカル株式会社 Adhesive sheet, layered sheet, flexible image display device member and flexible image display device

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