WO2020149386A1 - Crosslinkable block copolymer, production method therefor, and hot-melt adhesive - Google Patents

Crosslinkable block copolymer, production method therefor, and hot-melt adhesive Download PDF

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Publication number
WO2020149386A1
WO2020149386A1 PCT/JP2020/001387 JP2020001387W WO2020149386A1 WO 2020149386 A1 WO2020149386 A1 WO 2020149386A1 JP 2020001387 W JP2020001387 W JP 2020001387W WO 2020149386 A1 WO2020149386 A1 WO 2020149386A1
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polymer
crosslinkable
meth
polymer block
monomer
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PCT/JP2020/001387
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French (fr)
Japanese (ja)
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章滋 桑原
川端　和裕
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積水フーラー株式会社
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Publication of WO2020149386A1 publication Critical patent/WO2020149386A1/en

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/10—Esters
    • C08F220/12—Esters of monohydric alcohols or phenols
    • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
    • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F293/00—Macromolecular compounds obtained by polymerisation on to a macromolecule having groups capable of inducing the formation of new polymer chains bound exclusively at one or both ends of the starting macromolecule
    • 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
    • C09J153/00—Adhesives based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Adhesives based on derivatives of such polymers

Definitions

  • the present invention relates to a crosslinkable block copolymer, a method for producing the same, and a hot melt adhesive.
  • Acrylic adhesives are used in adhesive tapes and product labels. Further, since the acrylic pressure-sensitive adhesive is excellent in transparency, heat resistance and weather resistance, it is also used for optical displays of electronic devices such as personal computers, smartphones, televisions and digital cameras.
  • solvent-free adhesives are recommended from the viewpoint of improving the usage environment, and even acrylic adhesives are becoming hot-melt.
  • the hot-melt pressure-sensitive adhesive does not require a drying step for removing the solvent in the step of coating the support, and thus does not require equipment for the drying step and contributes greatly to energy saving.
  • Patent Document 1 At least two blocks of a non-elastomeric polymer block A and an elastomeric polymer block B composed of a (meth)acrylate-based polymer are bonded, and the non-elastomeric polymer block A determined by 1 H pulse NMR at 30° C.
  • the elastomer-polymer block A has a spin-spin relaxation time T 2 of 13 to 25 microseconds, its proton component ratio is 0.05 to 0.3, and the melting point or glass transition of the non-elastomeric polymer block A.
  • a reactive hot type which has a main component of a block copolymer having a number average molecular weight of 15,000 to 200,000, which has a proton component ratio of 0 at a temperature of not less than the above, and which is crosslinked or polymerized by heating or irradiation with active energy rays.
  • Melt adhesive compositions are disclosed.
  • the reactive hot-melt pressure-sensitive adhesive composition of Patent Document 1 has a markedly increased viscosity depending on the type and content of the monomers constituting the non-elastomeric polymer block A, which leads to a decrease in coatability and adhesiveness. And the thermal stability is also low.
  • the present invention has a low melt viscosity, excellent coatability and thermal stability, and exhibits excellent adhesive physical properties (particularly peeling resistance) by crosslinking, and a crosslinkable block copolymer excellent in ultraviolet curability and A hot melt adhesive using the same is provided.
  • the crosslinkable block copolymer comprises a polymer block B, And a polymer block A containing a benzyl (meth)acrylate-based monomer unit and a UV-crosslinkable monomer unit, each of which is bonded to both ends of the polymer block B.
  • the crosslinkable block copolymer is an ABA type triblock copolymer in which the polymer block A is bound to both ends of the polymer block B,
  • the polymer block A is characterized by containing a benzyl (meth)acrylate-based monomer unit and a UV-crosslinkable monomer unit.
  • the crosslinkable block copolymer of the present invention is an ABA type triblock copolymer in which the polymer block A is bound to both ends of the polymer block B.
  • a benzyl (meth)acrylate-based monomer and a UV crosslinkable monomer may be contained.
  • the (meth)acrylate means methacrylate or acrylate.
  • the polymer block A contains a monomer unit having an ultraviolet crosslinking property. Since the polymer block A contains a monomer unit having an ultraviolet-crosslinking property, the polymer block A and the polymer block B have different polarities from each other, thereby exhibiting a layer separation structure, and at the same time, the polymer block By positively introducing a crosslinked structure into A, the crosslinkable block copolymer has excellent peel resistance after crosslinking.
  • Ultraviolet crosslinkable monomer refers to a monomer having an ultraviolet crosslinkable group that forms a chemical bond upon irradiation with ultraviolet rays.
  • the "ultraviolet ray crosslinkability" means that a chemical bond is formed by irradiation of ultraviolet rays and thus the compound can be crosslinked.
  • the ultraviolet crosslinkable group is not particularly limited, and examples thereof include a thiol group, a glycidyl group, an oxetanyl group, a vinyl group, a (meth)acryloyl group, a benzophenone group, a benzoin group, a thioxanthone group, and the like, a glycidyl group, a benzophenone group.
  • a benzoin group and a thioxanthone group are preferable, a glycidyl group and a benzophenone group are more preferable, and a benzophenone group is particularly preferable.
  • (meth)acryloyl means methacryloyl or acryloyl.
  • (Meth)acryloxy means methacryloxy or acryloxy.
  • the UV-crosslinkable monomer is not particularly limited, and examples thereof include glycidyl (meth)acrylate, 4-hydroxybutyl acrylate glycidyl ether, 4-(meth)acryloyloxybenzophenone, and 4-[2-((meth)acryloyloxy.
  • the UV-crosslinkable group-containing monomer may be used alone or in combination of two or more kinds.
  • (meth)acryloyloxy means methacryloyloxy or acryloyloxy.
  • the content of the UV-crosslinkable monomer unit is preferably 40% by mass or less because the peel resistance after crosslinking of the crosslinkable block copolymer is improved. 10 mass% or less is more preferable, and 2 mass% or less is particularly preferable.
  • the content of the monomer unit having an ultraviolet crosslinking property is preferably 1% by mass or more because the ultraviolet curability of the crosslinkable block copolymer is improved.
  • a monomer having no ultraviolet crosslinking property (hereinafter referred to as "monomer having no ultraviolet crosslinking group” or “ultraviolet light”). Sometimes referred to as “non-crosslinkable monomer”).
  • monomer having no UV crosslinking property include a monomer capable of undergoing a polymerization reaction such as radical polymerization, cationic polymerization or anionic polymerization, and a monomer having an ethylenically unsaturated bond is preferable.
  • Examples of the monomer having no UV crosslinking property include a vinyl-based monomer, a (meth)acrylic-based monomer, and a (meth)acrylamide-based monomer, which have excellent radical polymerization reactivity. And (meth)acrylamide-based monomers are preferred.
  • (meth)acryl means acryl or methacryl.
  • vinyl monomers examples include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ⁇ -methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene and 2,4-dimethyl.
  • styrene-based monomers such as p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, and 3,4-dichlorostyrene.
  • the vinyl monomers may be used alone or in combination of two or more kinds.
  • Examples of the (meth)acryl-based monomer include benzyl (meth)acrylate-based monomer, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate and isobutyl (meth).
  • the crosslinkable block copolymer has an appropriate melt viscosity and is excellent.
  • Benzyl (meth)acrylate-based monomers are preferred because they have good coatability and excellent thermal stability, and also have excellent adhesive properties such as peeling resistance after crosslinking, and benzyl (meth)acrylate is preferred.
  • Acrylate is more preferred, and benzyl acrylate is particularly preferred.
  • the (meth)acrylic monomers may be used alone or in combination of two or more.
  • Examples of the (meth)acrylamide-based monomer include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, 2-hydroxyethyl(meth)acrylamide, N- Phenyl(meth)acrylamide, N-benzyl(meth)acrylamide, N-isobornyl(meth)acrylamide, N-cyclohexyl(meth)acrylamide, N-3,5,5-trimethylcyclohexyl(meth)acrylamide, N-dicyclopenta Examples thereof include nyl(meth)acrylamide, N-dicyclopentenyl(meth)acrylamide, N-adamantyl(meth)acrylamide, N,N-diphenyl(meth)acrylamide and the like.
  • the (meth)acrylamide-based monomers may be used alone or in combination of two or more kinds.
  • the crosslinkable block copolymer contains a benzyl (meth)acrylate-based monomer unit as a monomer unit having no UV crosslinkability in the monomer unit constituting the polymer block A.
  • the crosslinkable block copolymer has excellent coating properties and thermal stability, and also has excellent adhesiveness such as peeling resistance and It has excellent curability.
  • the benzyl (meth)acrylate-based monomer has the following structural formula.
  • the benzyl (meth)acrylate-based monomers may be used alone or in combination of two or more.
  • R 1 is a hydrogen atom or a methyl group
  • R 2 to R 6 are each independently a hydrogen atom or an alkyl group having 1 to 22 carbon atoms.
  • R 2 to R 6 may be the same or different.
  • R 2 to R 6 examples include methyl group, ethyl group, n-propyl group, isopropyl group, butyl group, pentyl group, hexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tetradecyl group. , Hexadecyl group, eicosyl group and the like.
  • R 1 is preferably a hydrogen atom or a methyl group
  • R 2 to R 6 are preferably hydrogen atoms
  • R 1 to R 6 are more preferably hydrogen atoms. .. That is, the benzyl (meth)acrylate-based monomer is preferably benzyl (meth)acrylate, and more preferably benzyl acrylate.
  • the content of the benzyl (meth)acrylate-based monomer unit is preferably 60% by mass or more, more preferably 90% by mass or more, and particularly preferably 98% by mass or more.
  • the content of the benzyl (meth)acrylate-based monomer is more preferably 99% by mass or less.
  • the content of the monomer unit having no ultraviolet crosslinking property is 60% by mass or more because the peel resistance after crosslinking of the crosslinkable block copolymer is improved. 90 mass% or more is more preferable, and 98 mass% or more is particularly preferable. In the monomer units constituting the polymer block A, the content of the monomer unit having no UV crosslinking property is more preferably 99% by mass or less.
  • the polymer block A is bonded to both ends of the polymer block B described later, and the crosslinkable block copolymer has an ABA type triblock structure.
  • the two polymer blocks A bonded to both ends of the polymer block B do not have to be the same and may be different. That is, in the two polymer blocks A bonded to both ends of the polymer block B, the type and content of the monomer units constituting the two polymer blocks A may be the same or different, The molecular weights may be the same or different.
  • the molecular weight of the polymer constituting the polymer block A is preferably 1,000 or more, more preferably 3,000 or more, and even more preferably 5,000 or more.
  • the polymer constituting the polymer block A has a molecular weight of preferably 50,000 or less, more preferably 30,000 or less, and further preferably 20,000 or less.
  • the crosslinkable block copolymer has excellent peel resistance after crosslinking.
  • the molecular weight of the polymer constituting the polymer block A is 50,000 or less, the crosslinkable block copolymer has an appropriate melt viscosity and excellent coatability.
  • the ratio of the molecular weights of the two polymer blocks A bonded to both ends of the polymer block B is preferably 2.0 or less, more preferably 1.8 or less, and particularly preferably 1.6 or less.
  • the ratio of the molecular weights is a value obtained by dividing the larger molecular weight of the two polymer blocks A and A by the smaller molecular weight.
  • the molecular weight of the polymer constituting the polymer block A is determined from the peak top molecular weight of the partial polymer of the polymer block A and the peak top molecular weight of the crosslinkable block copolymer. The value obtained by subtracting the peak top molecular weight of the polymer block B partial polymer.
  • the monomer forming the polymer block B of the crosslinkable block copolymer preferably has no UV crosslinking property (UV noncrosslinking property). That is, it is preferable that the monomer constituting the polymer block B of the polymer block B is a monomer not containing an ultraviolet crosslinking group (an ultraviolet noncrosslinking monomer). When the monomer constituting the polymer block B has no crosslinkability, the peeling resistance of the crosslinkable block copolymer after crosslinking is improved.
  • the monomer constituting the polymer block B of the crosslinkable block copolymer is not particularly limited, and examples thereof include a monomer capable of undergoing a polymerization reaction such as radical polymerization, cationic polymerization or anionic polymerization, and an ethylenically unsaturated bond.
  • the monomers having are preferred.
  • Examples of the monomer constituting the polymer block B include a vinyl-based monomer, a (meth)acrylic-based monomer, a (meth)acrylamide-based monomer, and the like. Since they have excellent radical polymerization reactivity, (meth) Acrylic monomers and (meth)acrylamide monomers are preferred. In addition, (meth)acryl means acryl or methacryl.
  • vinyl monomers examples include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ⁇ -methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene and 2,4-dimethyl.
  • styrene-based monomers such as p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, and 3,4-dichlorostyrene.
  • the vinyl monomers may be used alone or in combination of two or more kinds.
  • Examples of the (meth)acrylic monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth).
  • the crosslinkable block copolymer has an appropriate melt viscosity and excellent coatability.
  • Alkyl (meth)acrylates having an alkyl group with 1 to 12 carbon atoms are preferred because they have excellent adhesive properties such as peel resistance after crosslinking, and alkyl (meth) with an alkyl group with 2 to 10 carbon atoms Acrylate is more preferred, and alkyl(meth)acrylate in which the alkyl group has 4 to 8 carbon atoms is particularly preferred.
  • the (meth)acrylic monomers may be used alone or in combination of two or more.
  • Examples of the (meth)acrylamide-based monomer include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, 2-hydroxyethyl(meth)acrylamide, N- Phenyl(meth)acrylamide, N-benzyl(meth)acrylamide, N-isobornyl(meth)acrylamide, N-cyclohexyl(meth)acrylamide, N-3,5,5-trimethylcyclohexyl(meth)acrylamide, N-dicyclopenta Examples thereof include nyl(meth)acrylamide, N-dicyclopentenyl(meth)acrylamide, N-adamantyl(meth)acrylamide, N,N-diphenyl(meth)acrylamide and the like.
  • the (meth)acrylamide-based monomers may be used alone or in combination of two or more kinds.
  • the monomer constituting the polymer block B of the crosslinkable block copolymer preferably contains a carboxy group-containing monomer unit.
  • the carboxy group-containing monomer is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, ⁇ -carboxyethyl acrylate, ⁇ -carboxyethyl methacrylate, maleic acid, fumaric acid, and the like, with methacrylic acid and acrylic acid being preferred.
  • the content of the carboxy group-containing monomer unit is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and further preferably 1% by mass or more. 2 mass% or more is more preferable, and 2.5 mass% or more is more preferable.
  • the content of the carboxy group-containing monomer unit is preferably 25% by mass or less, more preferably 23% by mass or less, more preferably 20% by mass or less, and 10% by mass. The following is more preferable, and 5% by mass or less is more preferable.
  • the content of the carboxy group-containing monomer is 0.1% by mass or more, the peeling resistance of the crosslinkable block copolymer after crosslinking is improved.
  • the content of the carboxy group-containing monomer is 25 mass% or less, the coatability of the crosslinkable block copolymer is improved.
  • the monomer that constitutes the polymer block B and the monomer that does not have ultraviolet crosslinking property among the monomers that constitute the polymer block A may be the same or different.
  • the glass transition temperature of the polymer constituting the polymer block B is preferably 0° C. (273.15K (Kelvin)) or lower, more preferably ⁇ 20° C. (253.15K) or lower, and ⁇ 30° C. (243. 15 K) or less is more preferable, and ⁇ 40° C. (233.15 K) or less is particularly preferable.
  • the glass transition temperature of the polymer constituting the polymer block B is preferably ⁇ 80° C. (193.15K) or higher, more preferably ⁇ 70° C. (203.15K) or higher, and ⁇ 60° C. (213.15K). The above is particularly preferable.
  • peeling resistance of the crosslinkable block copolymer after crosslinking is improved.
  • the glass transition temperature (Kelvin) of the polymer constituting the polymer block B is calculated, for example, based on the following formula (Fox's formula).
  • Tg is the glass transition temperature (K, Kelvin) of the polymer constituting the polymer block B.
  • m is the number of kinds of monomers constituting the polymer in the polymer constituting the polymer block B and is a natural number.
  • Tgn is a glass transition temperature (K, Kelvin) of a polymer constituting the polymer block B, which a homopolymer of the n-th monomer constituting the polymer has.
  • Wn is the content (mass %) of the n-th monomer constituting the polymer of the polymer constituting the polymer block B.
  • Tgn was measured by DSC in accordance with JIS K7121, and after heating and cooling at a rate of 10°C/min, the DSC curve measured in the second run under a rate condition of 10°C/min. The temperature is at the midpoint of the step.
  • the total content of the polymer block A is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more.
  • the crosslinkable block copolymer has appropriate melt viscosity and excellent coatability, and at the same time, the crosslinkable block copolymer is It has excellent peeling resistance after crosslinking.
  • the total content of the polymer block A is preferably 39% by mass or less, more preferably 30% by mass or less, and particularly preferably 25% by mass or less.
  • the crosslinkable block copolymer When the total content of the polymer block A is within the above range, the crosslinkable block copolymer has appropriate melt viscosity and excellent coatability, and at the same time, the crosslinkable block copolymer is It has excellent peeling resistance after crosslinking.
  • the content of the polymer block B is preferably 61% by mass or more, more preferably 70% by mass or more, and further preferably 75% by mass or more.
  • the crosslinkable block copolymer has an appropriate melt viscosity and excellent coatability, and at the same time, the crosslinkable block copolymer is It has excellent peeling resistance after crosslinking.
  • the content of the polymer block B is preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 85% by mass or less.
  • the crosslinkable block copolymer When the total content of the polymer block B is within the above range, the crosslinkable block copolymer has an appropriate melt viscosity and excellent coatability, and at the same time, the crosslinkable block copolymer is It has excellent peeling resistance after crosslinking.
  • the molecular weight of the polymer constituting the polymer block B is preferably 5,000 or more, more preferably 30,000 or more, particularly preferably 50,000 or more.
  • the molecular weight of the polymer constituting the polymer block B is preferably 400000 or less, more preferably 240000 or less, and particularly preferably 150,000 or less.
  • the crosslinkable block copolymer has excellent peel resistance after crosslinking.
  • the molecular weight of the polymer constituting the polymer block A is 400000 or less, the crosslinkable block copolymer has an appropriate melt viscosity and excellent coatability.
  • the ratio of the molecular weight of the polymer constituting the polymer block A to the molecular weight of the polymer constituting the polymer block B is preferably 0.03 or more, more preferably 0.05 or more, and particularly preferably 0.08 or more.
  • the ratio of the molecular weight of the polymer constituting the polymer block A to the molecular weight of the polymer constituting the polymer block B is preferably 0.32 or less, more preferably 0.22 or less, and particularly preferably 0.17 or less.
  • the ratio of the molecular weight of the polymer forming the polymer block A to the molecular weight of the polymer forming the polymer block B is 0.03 or more, the crosslinkable block copolymer is excellent after crosslinking. Has peeling resistance.
  • the crosslinkable block copolymer has an appropriate melt viscosity. And has excellent coatability.
  • the molecular weight of the polymer constituting the polymer block A means the arithmetic average value of the molecular weights of the polymers constituting the polymer block A bonded to both ends of the polymer block B.
  • the molecular weight of the polymer constituting the polymer block B means the value calculated according to the following procedure.
  • the polymer constituting the polymer block B The molecular weight of is a value obtained by subtracting the peak top molecular weight of the polymer block A partial polymer from the peak top molecular weight of the polymer block A-polymer block B partial polymer.
  • the polymer constituting the polymer block B Is the value obtained by subtracting the peak top molecular weight of the polymer block A partial polymer from the peak top molecular weight of the crosslinkable block copolymer.
  • the weight average molecular weight (Mw) of the crosslinkable block copolymer is preferably 10,000 or more, more preferably 50,000 or more, more preferably 70,000 or more, and more preferably 80,000 or more.
  • the weight average molecular weight (Mw) of the crosslinkable block copolymer is preferably 500,000 or less, more preferably 300,000 or less, more preferably 250,000 or less, and more preferably 200,000 or less.
  • the weight average molecular weight (Mw) is 10,000 or more, the peeling resistance of the crosslinkable block copolymer is improved.
  • the weight average molecular weight (Mw) is 500000 or less, the crosslinkable block copolymer has an appropriate melt viscosity and excellent coatability.
  • the dispersity (weight average molecular weight Mw/number average molecular weight Mn) of the crosslinkable block copolymer is preferably 3.0 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. When the dispersity is 3.0 or less, the crosslinkable block copolymer has excellent peel resistance after crosslinking.
  • the molecular weight of the polymer constituting the polymer block of the crosslinkable block copolymer, and the weight average molecular weight and number average molecular weight of the crosslinkable block copolymer are measured by GPC (gel permeation chromatography) method. It is a value converted into polystyrene. Specifically, 0.01 g of the crosslinkable block copolymer was collected, the collected crosslinkable block copolymer was supplied to a test tube, and THF (tetrahydrofuran) was added to the test tube to add the crosslinkable block copolymer. The combined sample is diluted 500 times and filtered to prepare a measurement sample.
  • GPC gel permeation chromatography
  • the molecular weight of the polymer constituting the polymer block of the crosslinkable block copolymer, and the weight average molecular weight Mw and the number average molecular weight Mn of the crosslinkable block copolymer were measured by the GPC method. can do.
  • the molecular weight of the polymer constituting the polymer block of the crosslinkable block copolymer, and the weight average molecular weight Mw and the number average molecular weight Mn of the crosslinkable block copolymer are, for example, in the following measurement device and measurement conditions. Can be measured. Measuring apparatus Waters ACQUITY APC system Measurement conditions Column: Waters HSPgel(TM) HR MB-M Mobile phase: using tetrahydrofuran 0.5 mL/min Detector: RI detector Standard substance: polystyrene SEC temperature: 40°C
  • the crosslinkable block copolymer is an ABA type triblock copolymer, and the hard component is mainly composed of one of the polymer blocks A and B having a high glass transition temperature.
  • the soft component is mainly composed of one of the polymer blocks A and B having a low glass transition temperature.
  • a crosslinkable block copolymer is obtained. It is possible to favorably form a layer separation structure due to the polarity difference between the polymer blocks A and B of the block copolymer obtained by crosslinking the crosslinkable block copolymer while imparting appropriate hardness.
  • the block copolymer obtained by crosslinking the crosslinkable block copolymer can impart excellent peeling resistance, which is preferable.
  • a block copolymer obtained by crosslinking a crosslinkable block copolymer by incorporating a carboxy group-containing monomer as a monomer that does not have ultraviolet crosslinkability constituting the polymer block B has more excellent peeling resistance. ..
  • the crosslinkable block copolymer can be produced using a general-purpose polymerization method, but it is preferable to produce it using living polymerization.
  • living polymerization examples include living radical polymerization, living cationic polymerization, and living anionic polymerization, but living radical polymerization is preferable from the viewpoint of high versatility and safety of polymerization reaction.
  • Examples of the living radical polymerization method include iniferter polymerization, nitroxide-mediated polymerization (NMP), transition metal-catalyzed atom transfer radical addition polymerization (ATRP), dithioester compound reversible chain transfer polymerization (RAFT), and organic tellurium compound.
  • NMP nitroxide-mediated polymerization
  • ATRP transition metal-catalyzed atom transfer radical addition polymerization
  • RAFT dithioester compound reversible chain transfer polymerization
  • organic tellurium compound organic tellurium compound.
  • Polymerization TERP
  • RTCP reversible transfer catalytic polymerization
  • RCMP reversible coordination-mediated polymerization
  • RAFT reversible chain transfer polymerization
  • monomers (2) does not cause an extreme decrease in reactivity to oxygen and light, and (3) at extremely low or high temperatures. Since the reaction proceeds even without it, it can be carried out in a simple polymerization reaction environment and has high productivity, (4) no poisons such as metals and halogens are used, and (5) a crosslinkable block having a sufficient molecular weight. It is preferable because a copolymer can be produced.
  • the dithioester compound used for carrying out the reversible chain transfer polymerization (RAFT) is not particularly limited as long as it is a dithioester compound having exchange chain reactivity, and examples thereof include a dithiobenzoate compound, a trithiocarbonate compound, Examples thereof include dithiocarbamate compounds and xanthate compounds, with trithiocarbonate compounds being preferred.
  • the trithiocarbonate compound is not particularly limited, and examples thereof include 2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propanoic acid, 4- ⁇ [(2-carboxyethyl)sulfanylthiocarbonyl]sulfanyl ⁇ propanoic acid, 4-cyano.
  • a trithiocarbonate compound having only one exchange chain reaction site such as -4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid and 4-[(2-carboxyethylsulfanylthiocarbonyl)sulfanyl]-4-cyanopentanoic acid , S,S-dibenzyltrithiocarbonate, bis ⁇ 4-[ethyl-(2-hydroxyethyl)carbamoyl]benzyl ⁇ trithiocarbonate, etc., such as trithiocarbonate compounds having two exchange chain reaction sites.
  • a trithiocarbonate compound having only one chain reaction site is preferable, and 2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propanoic acid is more preferable.
  • the introduction position of the trithiocarbonate compound residue in the crosslinkable block copolymer differs due to the chemical structure of the trithiocarbonate compound.
  • the trithiocarbonate compound residue is introduced at the end of the polymer block constituting the crosslinkable block copolymer.
  • the trithiocarbonate compound residue is introduced inside the polymer block constituting the crosslinkable block copolymer.
  • a crosslinkable block copolymer produced by reversible chain transfer polymerization (RAFT) using a trithiocarbonate compound having only one exchange chain reaction site decomposes the trithiocarbonate compound residue by heat or light.
  • RAFT reversible chain transfer polymerization
  • the crosslinkable block copolymer structure itself is not decomposed, it is more excellent in thermal stability and UV crosslinking reactivity.
  • the crosslinkable block copolymer is preferably produced by reversible chain transfer polymerization (RAFT) with a dithioester compound.
  • RAFT reversible chain transfer polymerization
  • examples of the reversible chain transfer polymerization (RAFT) polymerization mode include bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization, and solution polymerization is preferable.
  • Multistep polymerization is performed to produce a crosslinkable block copolymer.
  • RAFT reversible chain transfer polymerization
  • a monomer constituting the polymer block A is converted into a dithioester compound (dithioester compound). It polymerizes sufficiently (in the presence of a compound) to obtain a polymer block A partial polymer (first stage polymerization).
  • a monomer that constitutes the polymer block B is supplied into the polymerization reaction system and sufficiently polymerized to obtain a polymer block A-polymer block B partial polymer (second-stage polymerization).
  • an ABA type triblock obtained by supplying the monomer constituting the polymer block A into the polymerization reaction system and sufficiently polymerizing it to bond the polymer block A to both ends of the polymer block B.
  • a crosslinkable block copolymer which is a copolymer can be obtained.
  • RAFT reversible chain transfer polymerization
  • the dithioester compound is used as the monomer constituting the polymer block A.
  • (Below) polymerize sufficiently to obtain polymer block A partial polymer (first stage polymerization).
  • a monomer constituting the polymer block B is supplied into the polymerization reaction system and polymerized (second-stage polymerization) to form a polymer block B in the intermediate part of the polymer block A partial polymer, and A A crosslinkable block copolymer which is a —BA type triblock copolymer can be obtained.
  • a crosslinkable block copolymer produced using a dithioester compound may have a coloring derived from its chemical structure or a unique odor derived from a sulfur atom.
  • a treatment for reducing or removing a dithioester compound residue in the crosslinkable block copolymer, and a residual dithioester mixed in the crosslinkable block copolymer It is preferable to perform a compound reduction or removal treatment.
  • the treatment method for reducing or removing the dithioester compound residue or the residual dithioester compound include treatment with heat, treatment with ultraviolet light, treatment with excess radical initiator, treatment with nucleophile or reducing agent, treatment with oxidizing agent.
  • the content of the benzyl (meth)acrylate-based monomer in the raw material monomer for producing the polymer block A is preferably 60% by mass or more, more preferably 90% by mass or more, and particularly preferably 98% by mass or more. ..
  • the content of the benzyl (meth)acrylate-based monomer is preferably 99% by mass or less.
  • the content of the UV-crosslinkable monomer is preferably 40% by mass or less, more preferably 10% by mass or less, and particularly preferably 2% by mass or less.
  • the content of the UV-crosslinkable monomer in the monomer, which is a raw material for producing the polymer block A is preferably 1% by mass or more.
  • the content of the monomer having no ultraviolet crosslinking property is preferably 60% by mass or more, more preferably 90% by mass or more, and particularly preferably 98% by mass or more. ..
  • the content of the monomer having no ultraviolet crosslinking property in the raw material monomer for producing the polymer block A is preferably 99% by mass or less.
  • the content of the carboxy group-containing monomer in the raw material monomer for producing the polymer block B is preferably 1 to 20% by mass, more preferably 2 to 10% by mass, and 2.5 to 5% by mass. Particularly preferred.
  • the content of the carboxy group-containing monomer is 1% by mass or more, the peeling resistance of the crosslinkable block copolymer after crosslinking is improved.
  • the content of the carboxy group-containing monomer is 20% by mass or less, the coatability of the crosslinkable block copolymer is improved.
  • the crosslinkable block copolymer can be suitably used as a hot-melt pressure-sensitive adhesive by adding additives such as a tackifier and a photo-acid generator, if necessary.
  • the hot-melt pressure-sensitive adhesive containing the crosslinkable block copolymer has an appropriate melt viscosity and therefore has excellent coatability.
  • the crosslinkable block copolymer is coated on the adherend and then subjected to a crosslinking treatment to the crosslinkable block copolymer, whereby the crosslinkable monomer units contained in the polymer block A are
  • the crosslinkable group forms a crosslinked structure, and the crosslinked structure is introduced into the polymer block A.
  • the block copolymer having the crosslinked structure introduced exhibits excellent tackiness such as peel resistance.
  • Hot-melt pressure-sensitive adhesives are tackifiers, photo-acid generators (UV cation generators), UV polymerization initiators, plasticizers, antioxidants, colorants, flame retardants and antistatic agents, as long as their physical properties are not impaired. Additives such as agents may be included.
  • the crosslinkable block copolymer of the present invention has a low viscosity, excellent coatability, and excellent thermal stability.
  • the block copolymer obtained by cross-linking the cross-linkable block copolymer of the present invention is excellent in adhesive property, particularly peeling resistance.
  • Examples 1 to 3 and 5 to 17 and Comparative Examples 1 to 4 In a separable flask equipped with a stirrer, a cooling tube, a thermometer and a nitrogen gas inlet, benzyl acrylate, benzyl methacrylate, n-butyl acrylate, isobornyl acrylate, phenoxyethyl acrylate and t-butyl acrylate as UV non-crosslinking monomers.
  • Propanoic acid (one exchange chain reaction site) and 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid (one exchange chain reaction site) and ethyl acetate as the solvent are shown in Tables 1 and 2, respectively. Each of the compounding amounts shown in 1 was supplied and stirred to prepare a reaction liquid.
  • reaction solution After purging the inside of the separable flask with nitrogen gas, the reaction solution was kept at 60° C. using a water bath. Then, 2,2′-azobis(isobutyronitrile) as a polymerization initiator was supplied to the reaction solution in the separable flask in the compounding amounts shown in Tables 1 and 2 to start reversible chain transfer polymerization (RAFT). did.
  • the reaction liquid was kept at 60° C. for 6 hours to obtain a polymer block A partial polymer.
  • the peak top molecular weight and the weight average molecular weight of the polymer block A partial polymer are shown in Tables 4 and 5.
  • a reaction liquid containing the polymer block A partial polymer n-butyl acrylate, 2-ethylhexyl acrylate, acrylic acid and ⁇ -carboxyethyl acrylate as a UV non-crosslinking monomer, and ethyl acetate as a solvent are shown in Tables 1 and 2, respectively. The respective compounding amounts shown in were supplied.
  • the reaction solution was kept at 60° C. for 6 hours for reversible chain transfer polymerization (RAFT) to obtain a polymer block A-polymer block B partial polymer.
  • Tables 4 and 5 show the peak top molecular weights of the polymers constituting the polymer block A-polymer block B partial polymer and the weight average molecular weights of the polymer block A-polymer block B partial polymer. ..
  • a reaction solution containing a polymer block A-polymer block B partial polymer benzyl acrylate, benzyl methacrylate, n-butyl acrylate, isobornyl acrylate, phenoxyethyl acrylate and t-butyl acrylate as UV non-crosslinkable monomers, 4-Acryloyloxybenzophenone, 4-hydroxybutyl acrylate glycidyl ether and 4-[2-(acryloyloxy)ethoxy]benzophenone were used as crosslinking monomers, and ethyl acetate was used as a solvent in the amounts shown in Tables 1 and 2, respectively. .. The reaction solution was kept at 60° C.
  • the crosslinkable block copolymer was an ABA type triblock copolymer in which the polymer block A was bound to both ends of the polymer block B.
  • the peak top molecular weight, weight average molecular weight and dispersity of the crosslinkable block copolymer are shown in Tables 1 and 2.
  • the total content of polymer block A and the content of polymer block B in the crosslinkable block copolymer are shown in Tables 4 and 5.
  • Example 4 In a separable flask equipped with a stirrer, a cooling tube, a thermometer and a nitrogen gas inlet, benzyl acrylate as a UV non-crosslinking monomer, 4-acryloyloxybenzophenone as a crosslinkable monomer, and S,S- as a trithiocarbonate compound. Dibenzyl trithiocarbonate (two exchange chain reaction sites) and ethyl acetate as a solvent were supplied in the respective compounding amounts shown in Table 1 and stirred to prepare a reaction solution.
  • reaction solution After purging the inside of the separable flask with nitrogen gas, the reaction solution was kept at 60° C. using a water bath. Next, 2,2'-azobis(isobutyronitrile) as a polymerization initiator was supplied to the reaction solution in the separable flask in the compounding amounts shown in Table 1 to initiate reversible chain transfer polymerization (RAFT). The reaction liquid was kept at 60° C. for 6 hours to obtain a polymer block A partial polymer. The peak top molecular weight and the weight average molecular weight of the polymer block A partial polymer are shown in Table 4.
  • RAFT reversible chain transfer polymerization
  • RAFT reversible chain transfer polymerization
  • the crosslinkable block copolymer was an ABA type triblock copolymer in which the polymer block A was bound to both ends of the polymer block B.
  • Table 4 shows the peak top molecular weight, weight average molecular weight, and dispersity of the crosslinkable block copolymer.
  • Table 4 shows the total content of the polymer block A and the content of the polymer block B in the crosslinkable block copolymer.
  • RAFT reversible chain transfer polymerization
  • Table 3 shows the peak top molecular weight, weight average molecular weight and dispersity of the crosslinkable random copolymer.
  • the glass transition temperatures of the polymers constituting the polymer block B are shown in Tables 4 and 5.
  • the measuring device shown below was prepared. 13 g of the hot melt adhesive was collected and put into an aluminum cylinder mounted in Thermosel. The temperature was set to 130° C. to melt the hot melt adhesive. Melt viscosity measurements were taken over 30 minutes using spindle 4-29. The numerical value after the measurement for 30 minutes was read to obtain the melt viscosity at 130°C. Measuring device: DV-E Viscometer (manufactured by Brookfield) Thermosel (manufactured by Brookfield)
  • melt viscosity was less than 70 Pa ⁇ s.
  • B Melt viscosity was 70 Pa ⁇ s or more and less than 150 Pa ⁇ s.
  • C Melt viscosity was 150 Pa ⁇ s or more.
  • melt viscosity initial melt viscosity
  • melt viscosity change rate Melt viscosity after 1 week/initial melt viscosity A... The melt viscosity change rate was less than 2.
  • B The rate of change in melt viscosity was 2 or more.
  • UV curable The hot melt adhesive was applied onto a polyethylene terephthalate (PET) film that had been subjected to a mold release treatment so that the thickness would be 20 ⁇ m.
  • UV-C irradiation intensity about 48 mW/cm 2
  • UV-C integrated light amount using an ultraviolet irradiation device (Hereus (former Fusion UV Systems), trade name “Light Hammer 6” (H bulb used))
  • UV-C ultraviolet rays
  • the cured hot melt adhesive was peeled off from the polyethylene terephthalate film, and 0.2 g of the hot melt adhesive was supplied to the glass bottle. 30 g of tetrahydrofuran was supplied to a glass bottle and left at 25° C. for 24 hours to swell the hot melt adhesive.
  • the hot melt adhesive was applied onto a polyethylene terephthalate (PET) film so as to have a thickness of 20 ⁇ m.
  • UV-C irradiation intensity about 48 mW/cm 2
  • UV-C integrated light amount using an ultraviolet irradiation device (Hereus (former Fusion UV Systems), trade name “Light Hammer 6” (H bulb used))
  • UV-C ultraviolet rays
  • a 20 ⁇ m-thick adhesive layer was laminated and integrated on a polyethylene terephthalate film to prepare a test piece.
  • a test film was prepared by cutting the test film into a width of 15 mm and a length of 150 mm.
  • a SUS plate was prepared, the surface of the SUS plate was polished with a #240 water resistant sandpaper, and then wiped with a mixed solvent of hexane and acetone to degrease.
  • test piece bonding surface was installed so as to face downward.
  • the weight of 150 g was hung on the end portion of the test piece not attached to the SUS plate, and the measurement was started in a state where the load was applied so that the test piece was peeled off at an angle of 90 degrees with respect to the SUS surface. The measurement was terminated when the bonded 75 mm was entirely peeled off and the test piece dropped, or when 1 hour passed from the start of the measurement.
  • the peeling distance at which the test piece peeled from the SUS plate was measured.
  • the peeling distance at the time when 1 hour passed from the start of the test was proportionally calculated based on the time required for the test piece to fall from the start of the test. The shorter the peeling distance, the better the peeling resistance.
  • A-PET amorphous polyethylene terephthalate

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Abstract

The present invention provides a crosslinkable block copolymer which has a low melt viscosity and excellent coatability and thermal stability, exhibits excellent adhesive properties (in particular, peeling resistance) due to crosslinking, and has excellent UV-curability. This crosslinkable block copolymer is characterized by containing a polymer block B and polymer blocks A that are joined to the respective ends of the polymer block B and include benzyl (meth)acrylate monomer units and monomer units crosslinkable by ultraviolet light.

Description

架橋性ブロック共重合体及びその製造方法並びにホットメルト粘着剤Crosslinkable block copolymer, method for producing the same, and hot melt adhesive
　本発明は、架橋性ブロック共重合体及びその製造方法並びにホットメルト粘着剤に関する。 The present invention relates to a crosslinkable block copolymer, a method for producing the same, and a hot melt adhesive.
　アクリル系粘着剤は、粘着テープや商品ラベルなどに用いられている。更に、アクリル系粘着剤は、透明性、耐熱性及び耐候性に優れていることから、パソコン、スマートフォン、テレビ及びデジタルカメラなどの電子機器の光学ディスプレイなどにも用いられている。 Acrylic adhesives are used in adhesive tapes and product labels. Further, since the acrylic pressure-sensitive adhesive is excellent in transparency, heat resistance and weather resistance, it is also used for optical displays of electronic devices such as personal computers, smartphones, televisions and digital cameras.
　又、使用環境の改善の観点から粘着剤の無溶剤化が推奨されており、アクリル系粘着剤においてもホットメルト化が進んでいる。ホットメルト粘着剤は、支持体への塗工工程において溶剤を除去するための乾燥工程が必要ないことから、乾燥工程用の設備を必要とせず、省エネルギー化にも大きく貢献する。 Also, solvent-free adhesives are recommended from the viewpoint of improving the usage environment, and even acrylic adhesives are becoming hot-melt. The hot-melt pressure-sensitive adhesive does not require a drying step for removing the solvent in the step of coating the support, and thus does not require equipment for the drying step and contributes greatly to energy saving.
アクリル系ホットメルト粘着剤においてホットメルト塗工性を発現させるために、アクリル系重合体の分子量を小さく設計する必要がある。しかし、分子量を小さくすることで粘着特性が得られなくなるため、ホットメルト塗工後に、架橋反応や鎖延長反応などを行なって架橋化（硬化）、高分子量化することが必要である。 In order to exhibit hot melt coatability in the acrylic hot melt adhesive, it is necessary to design the molecular weight of the acrylic polymer to be small. However, since adhesive properties cannot be obtained by reducing the molecular weight, it is necessary to carry out cross-linking reaction, chain extension reaction or the like to cross-link (cur) and increase the molecular weight after hot-melt coating.
　特許文献１には、非エラストマー性重合体ブロックＡと（メタ）アクリレート系重合体からなるエラストマー性重合体ブロックＢとが少なくとも２ブロック結合してなり、３０℃における1ＨパルスＮＭＲで求めた非エラストマー性重合体ブロックＡのスピン－スピン緩和時間Ｔ2 が１３～２５マイクロ秒で、そのプロトン成分比が０．０５～０．３であり、かつ非エラストマー性重合体ブロックＡの融点またはガラス転移温度以上では上記のプロトン成分比が０となる、数平均分子量１５，０００～２００，０００のブロック共重合体を主剤成分とし、加熱または活性エネルギー線の照射により架橋ないし高分子量化する反応型ホットメルト粘着剤組成物が開示されている。 In Patent Document 1, at least two blocks of a non-elastomeric polymer block A and an elastomeric polymer block B composed of a (meth)acrylate-based polymer are bonded, and the non-elastomeric polymer block A determined by 1 H pulse NMR at 30° C. The elastomer-polymer block A has a spin-spin relaxation time T 2 of 13 to 25 microseconds, its proton component ratio is 0.05 to 0.3, and the melting point or glass transition of the non-elastomeric polymer block A. A reactive hot type which has a main component of a block copolymer having a number average molecular weight of 15,000 to 200,000, which has a proton component ratio of 0 at a temperature of not less than the above, and which is crosslinked or polymerized by heating or irradiation with active energy rays. Melt adhesive compositions are disclosed.
特開２００２－６９４１２号公報JP-A-2002-69412
　特許文献１の反応型ホットメルト粘着剤組成物は、非エラストマー性重合体ブロックＡを構成しているモノマーの種類及び含有量などによっては著しく粘度が上昇し、塗工性が低下すると共に粘着性も低下し、更に、熱安定性も低いという問題点を有する。 The reactive hot-melt pressure-sensitive adhesive composition of Patent Document 1 has a markedly increased viscosity depending on the type and content of the monomers constituting the non-elastomeric polymer block A, which leads to a decrease in coatability and adhesiveness. And the thermal stability is also low.
　本発明は、溶融粘度が低くて塗工性及び熱安定性に優れ、且つ、架橋によって優れた粘着物性（特に耐剥がれ性）を発現し、紫外線硬化性に優れた架橋性ブロック共重合体及びこれを用いたホットメルト粘着剤を提供する。 The present invention has a low melt viscosity, excellent coatability and thermal stability, and exhibits excellent adhesive physical properties (particularly peeling resistance) by crosslinking, and a crosslinkable block copolymer excellent in ultraviolet curability and A hot melt adhesive using the same is provided.
　架橋性ブロック共重合体は、重合体ブロックＢと、
　上記重合体ブロックＢの両末端のそれぞれに結合し且つベンジル（メタ）アクリレート系モノマー単位及び紫外線架橋性を有するモノマー単位を含む重合体ブロックＡとを含む。 The crosslinkable block copolymer comprises a polymer block B,
And a polymer block A containing a benzyl (meth)acrylate-based monomer unit and a UV-crosslinkable monomer unit, each of which is bonded to both ends of the polymer block B.
　架橋性ブロック共重合体は、重合体ブロックＢの両末端に重合体ブロックＡが結合してなるＡ－Ｂ－Ａ型トリブロック共重合体であって、
　上記重合体ブロックＡは、ベンジル（メタ）アクリレート系モノマー単位及び紫外線架橋性を有するモノマー単位を含むことを特徴とする。 The crosslinkable block copolymer is an ABA type triblock copolymer in which the polymer block A is bound to both ends of the polymer block B,
The polymer block A is characterized by containing a benzyl (meth)acrylate-based monomer unit and a UV-crosslinkable monomer unit.
［架橋性ブロック共重合体］
　本発明の架橋性ブロック共重合体は、重合体ブロックＢの両末端に重合体ブロックＡが結合してなるＡ－Ｂ－Ａ型トリブロック共重合体である。 [Crosslinkable block copolymer]
The crosslinkable block copolymer of the present invention is an ABA type triblock copolymer in which the polymer block A is bound to both ends of the polymer block B.
　架橋性ブロック共重合体の重合体ブロックＡを構成しているモノマーとしては、ベンジル（メタ）アクリレート系モノマー及び紫外線架橋性を有するモノマーを含有しておればよい。なお、（メタ）アクリレートは、メタクリレート又はアクリレートを意味する。 As the monomer constituting the polymer block A of the crosslinkable block copolymer, a benzyl (meth)acrylate-based monomer and a UV crosslinkable monomer may be contained. The (meth)acrylate means methacrylate or acrylate.
　重合体ブロックＡは、紫外線架橋性を有するモノマー単位を含有している。重合体ブロックＡが紫外線架橋性を有するモノマー単位を含有していることによって、重合体ブロックＡ及び重合体ブロックＢの極性を互いに相違させることによって層分離構造を発現させていると共に、重合体ブロックＡに積極的に架橋構造を導入させることによって、架橋性ブロック共重合体は架橋後において優れた耐剥がれ性を有する。 The polymer block A contains a monomer unit having an ultraviolet crosslinking property. Since the polymer block A contains a monomer unit having an ultraviolet-crosslinking property, the polymer block A and the polymer block B have different polarities from each other, thereby exhibiting a layer separation structure, and at the same time, the polymer block By positively introducing a crosslinked structure into A, the crosslinkable block copolymer has excellent peel resistance after crosslinking.
　紫外線架橋性を有するモノマー（以下「紫外線架橋性モノマー」ということがある）とは、紫外線の照射によって化学結合を形成する紫外線架橋性基を有するモノマーをいう。「紫外線架橋性」とは、紫外線の照射によって化学結合を形成して架橋可能であることをいう。 “Ultraviolet crosslinkable monomer (hereinafter sometimes referred to as “ultraviolet crosslinkable monomer”) refers to a monomer having an ultraviolet crosslinkable group that forms a chemical bond upon irradiation with ultraviolet rays. The "ultraviolet ray crosslinkability" means that a chemical bond is formed by irradiation of ultraviolet rays and thus the compound can be crosslinked.
　紫外線架橋性基としては、特に限定されず、例えば、チオール基、グリシジル基、オキセタニル基、ビニル基、（メタ）アクリロイル基、ベンゾフェノン基、ベンゾイン基、チオキサントン基などが挙げられ、グリシジル基、ベンゾフェノン基、ベンゾイン基及びチオキサントン基が好ましく、グリシジル基、ベンゾフェノン基がより好ましく、ベンゾフェノン基が特に好ましい。なお、（メタ）アクリロイルは、メタクリロイル又はアクリロイルを意味する。（メタ）アクリロキシは、メタクリロキシ又はアクリロキシを意味する。 The ultraviolet crosslinkable group is not particularly limited, and examples thereof include a thiol group, a glycidyl group, an oxetanyl group, a vinyl group, a (meth)acryloyl group, a benzophenone group, a benzoin group, a thioxanthone group, and the like, a glycidyl group, a benzophenone group. , A benzoin group and a thioxanthone group are preferable, a glycidyl group and a benzophenone group are more preferable, and a benzophenone group is particularly preferable. In addition, (meth)acryloyl means methacryloyl or acryloyl. (Meth)acryloxy means methacryloxy or acryloxy.
　紫外線架橋性を有するモノマーとしては、特に限定されず、例えば、グリシジル（メタ）アクリレート、４－ヒドロキシブチルアクリレートグリシジルエーテル、４－（メタ）アクリロイルオキシベンゾフェノン、４－［２－（（メタ）アクリロイルオキシ）エトキシ］ベンゾフェノン、４－（メタ）アクリロイルオキシ－４’－メトキシベンゾフェノン、４－（メタ）アクリロイルオキシエトキシ－４’－メトキシベンゾフェノン、４－（メタ）アクリロイルオキシ－４’－ブロモベンゾフェノン、４－（メタ）アクリロイルオキシエトキシ－４’－ブロモベンゾフェノンなどが挙げられ、架橋性ブロック共重合体の熱安定性及び塗工性が向上すると共に、架橋性ブロック共重合体の架橋後の耐剥がれ性が向上するので、４－ヒドロキシブチルアクリレートグリシジルエーテル、４－（メタ）アクリロイルオキシベンゾフェノン及び４－［２－（（メタ）アクリロイルオキシ）エトキシ］ベンゾフェノンが好ましく、４－（メタ）アクリロイルオキシベンゾフェノンがより好ましい。紫外線架橋性基を有するモノマーは、単独で用いられても二種以上が併用されてもよい。なお、（メタ）アクリロイルオキシは、メタクリロイルオキシ又はアクリロイルオキシを意味する。 The UV-crosslinkable monomer is not particularly limited, and examples thereof include glycidyl (meth)acrylate, 4-hydroxybutyl acrylate glycidyl ether, 4-(meth)acryloyloxybenzophenone, and 4-[2-((meth)acryloyloxy. )Ethoxy]benzophenone, 4-(meth)acryloyloxy-4′-methoxybenzophenone, 4-(meth)acryloyloxyethoxy-4′-methoxybenzophenone, 4-(meth)acryloyloxy-4′-bromobenzophenone, 4- Examples thereof include (meth)acryloyloxyethoxy-4′-bromobenzophenone, which improves the thermal stability and coatability of the crosslinkable block copolymer and also improves the peel resistance of the crosslinkable block copolymer after crosslinking. 4-hydroxybutyl acrylate glycidyl ether, 4-(meth)acryloyloxybenzophenone and 4-[2-((meth)acryloyloxy)ethoxy]benzophenone are preferable, and 4-(meth)acryloyloxybenzophenone is more preferable. .. The UV-crosslinkable group-containing monomer may be used alone or in combination of two or more kinds. In addition, (meth)acryloyloxy means methacryloyloxy or acryloyloxy.
　重合体ブロックＡを構成しているモノマー単位中において、紫外線架橋性を有するモノマー単位の含有量は、架橋性ブロック共重合体の架橋後における耐剥がれ性が向上するので、４０質量％以下が好ましく、１０質量％以下がより好ましく、２質量％以下が特に好ましい。重合体ブロックＡを構成しているモノマー単位中において、紫外線架橋性を有するモノマー単位の含有量は、架橋性ブロック共重合体の紫外線硬化性が向上するので、１質量％以上が好ましい。 In the monomer units constituting the polymer block A, the content of the UV-crosslinkable monomer unit is preferably 40% by mass or less because the peel resistance after crosslinking of the crosslinkable block copolymer is improved. 10 mass% or less is more preferable, and 2 mass% or less is particularly preferable. In the monomer unit constituting the polymer block A, the content of the monomer unit having an ultraviolet crosslinking property is preferably 1% by mass or more because the ultraviolet curability of the crosslinkable block copolymer is improved.
　架橋性ブロック共重合体の重合体ブロックＡを構成しているモノマーとして、紫外線架橋性を有するモノマー以外に、紫外線架橋性を有しないモノマー（以下「紫外線架橋性基を含有しないモノマー」又は「紫外線非架橋性モノマー」ということがある）が含まれている。このような紫外線架橋性を有しないモノマーとしては、例えば、ラジカル重合、カチオン重合又はアニオン重合などの重合反応し得るモノマーなどが挙げられ、エチレン性不飽和結合を有するモノマーが好ましい。 As the monomer constituting the polymer block A of the crosslinkable block copolymer, in addition to the monomer having ultraviolet crosslinking property, a monomer having no ultraviolet crosslinking property (hereinafter referred to as "monomer having no ultraviolet crosslinking group" or "ultraviolet light"). Sometimes referred to as "non-crosslinkable monomer"). Examples of such a monomer having no UV crosslinking property include a monomer capable of undergoing a polymerization reaction such as radical polymerization, cationic polymerization or anionic polymerization, and a monomer having an ethylenically unsaturated bond is preferable.
　紫外線架橋性を有しないモノマーとしては、例えば、ビニル系モノマー、（メタ）アクリル系モノマー、（メタ）アクリルアミド系モノマーなどが挙げられ、ラジカル重合反応性に優れているので、（メタ）アクリル系モノマー及び（メタ）アクリルアミド系モノマーが好ましい。なお、（メタ）アクリルとは、アクリル又はメタクリルを意味する。 Examples of the monomer having no UV crosslinking property include a vinyl-based monomer, a (meth)acrylic-based monomer, and a (meth)acrylamide-based monomer, which have excellent radical polymerization reactivity. And (meth)acrylamide-based monomers are preferred. In addition, (meth)acryl means acryl or methacryl.
　ビニル系モノマーとしては、例えば、スチレン、ｏ－メチルスチレン、ｍ－メチルスチレン、ｐ－メチルスチレン、α－メチルスチレン、ｏ－エチルスチレン、ｍ－エチルスチレン、ｐ－エチルスチレン、２，４－ジメチルスチレン、ｐ－ｎ－ブチルスチレン、ｐ－ｔ－ブチルスチレン、ｐ－ｎ－ヘキシルスチレン、ｐ－ｎ－オクチルスチレン、ｐ－ｎ－ノニルスチレン、ｐ－ｎ－デシルスチレン、ｐ－ｎ－ドデシルスチレン、ｐ－メトキシスチレン、ｐ－フェニルスチレン、ｐ－クロロスチレン、３，４－ジクロロスチレンなどのスチレン系モノマーなどが挙げられる。なお、ビニル系モノマーは、単独で用いられても二種以上が併用されてもよい。 Examples of vinyl monomers include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene and 2,4-dimethyl. Styrene, pn-butylstyrene, pt-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene And styrene-based monomers such as p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, and 3,4-dichlorostyrene. The vinyl monomers may be used alone or in combination of two or more kinds.
　（メタ）アクリル系モノマーとしては、例えば、ベンジル（メタ）アクリレート系モノマー、メチル（メタ）アクリレート、エチル（メタ）アクリレート、ｎ－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、ｓｅｃ－ブチル（メタ）アクリレート、ｔ－ブチルアクリレート、ｎ－ヘキシル（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、イソオクチル（メタ）アクリレート、ｎ－ノニル（メタ）アクリレート、イソノニル（メタ）アクリレート、ｎ－デシル（メタ）アクリレート、ラウリル（メタ）メタクリレート、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、３－ヒドロキシプロピル（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、４－ヒドロキシブチル（メタ）アクリレート、イソボルニル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、３，５，５－トリメチルシクロヘキシル（メタ）アクリレート、フェニル（メタ）アクリレート、ジシクロペンタニル（メタ）アクリレート、ジシクロペンテニル（メタ）アクリレート、アダマンチル（メタ）アクリレートなどのアクリレート、（メタ）アクリル酸などが挙げられ、架橋性ブロック共重合体は適度な溶融粘度を有して優れた塗工性を有していると共に優れた熱安定性を有し、更に、架橋後において耐剥がれ性などの粘着物性に優れているので、ベンジル（メタ）アクリレート系モノマーが好ましく、ベンジル（メタ）アクリレートがより好ましく、ベンジルアクリレートが特に好ましい。なお、（メタ）アクリル系モノマーは、単独で用いられても二種以上が併用されてもよい。 Examples of the (meth)acryl-based monomer include benzyl (meth)acrylate-based monomer, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate and isobutyl (meth). ) Acrylate, sec-butyl(meth)acrylate, t-butyl acrylate, n-hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, n-octyl(meth)acrylate, isooctyl(meth)acrylate, n-nonyl( (Meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, lauryl (meth)methacrylate, stearyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2- Hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, 3,5,5-trimethylcyclohexyl (meth)acrylate, phenyl (meth)acrylate, dicyclopenta Nyl (meth) acrylate, dicyclopentenyl (meth) acrylate, acrylates such as adamantyl (meth) acrylate, (meth) acrylic acid, etc. are mentioned, and the crosslinkable block copolymer has an appropriate melt viscosity and is excellent. Benzyl (meth)acrylate-based monomers are preferred because they have good coatability and excellent thermal stability, and also have excellent adhesive properties such as peeling resistance after crosslinking, and benzyl (meth)acrylate is preferred. Acrylate is more preferred, and benzyl acrylate is particularly preferred. The (meth)acrylic monomers may be used alone or in combination of two or more.
　（メタ）アクリルアミド系モノマーとしては、例えば、Ｎ，Ｎ－ジメチル（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、２－ヒドロキシエチル（メタ）アクリルアミド、Ｎ－フェニル（メタ）アクリルアミド、Ｎ－ベンジル（メタ）アクリルアミド、Ｎ－イソボルニル（メタ）アクリルアミド、Ｎ－シクロヘキシル（メタ）アクリルアミド、Ｎ－３，５，５－トリメチルシクロヘキシル（メタ）アクリルアミド、Ｎ－ジシクロペンタニル（メタ）アクリルアミド、Ｎ－ジシクロペンテニル（メタ）アクリルアミド、Ｎ－アダマンチル（メタ）アクリルアミド、Ｎ，Ｎ－ジフェニル（メタ）アクリルアミドなどが挙げられる。なお、（メタ）アクリルアミド系モノマーは、単独で用いられても二種以上が併用されてもよい。
Examples of the (meth)acrylamide-based monomer include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, 2-hydroxyethyl(meth)acrylamide, N- Phenyl(meth)acrylamide, N-benzyl(meth)acrylamide, N-isobornyl(meth)acrylamide, N-cyclohexyl(meth)acrylamide, N-3,5,5-trimethylcyclohexyl(meth)acrylamide, N-dicyclopenta Examples thereof include nyl(meth)acrylamide, N-dicyclopentenyl(meth)acrylamide, N-adamantyl(meth)acrylamide, N,N-diphenyl(meth)acrylamide and the like. The (meth)acrylamide-based monomers may be used alone or in combination of two or more kinds.
　架橋性ブロック共重合体は、重合体ブロックＡを構成しているモノマー単位中に、紫外線架橋性を有しないモノマー単位としてベンジル（メタ）アクリレート系モノマー単位を含んでいる。ベンジル（メタ）アクリレート系モノマー単位を含むことによって、架橋性ブロック共重合体は、優れた塗工性及び熱安定性を有していると共に、耐剥がれ性などの粘着性に優れており、紫外線硬化性に優れている。 The crosslinkable block copolymer contains a benzyl (meth)acrylate-based monomer unit as a monomer unit having no UV crosslinkability in the monomer unit constituting the polymer block A. By including the benzyl (meth)acrylate-based monomer unit, the crosslinkable block copolymer has excellent coating properties and thermal stability, and also has excellent adhesiveness such as peeling resistance and It has excellent curability.
　ベンジル（メタ）アクリレート系モノマーは、下記構造式を有する。なお、ベンジル（メタ）アクリレート系モノマーは単独で用いられても二種以上が併用されてもよい。 The benzyl (meth)acrylate-based monomer has the following structural formula. The benzyl (meth)acrylate-based monomers may be used alone or in combination of two or more.
Figure JPOXMLDOC01-appb-C000001
Figure JPOXMLDOC01-appb-C000001
　但し、Ｒ1は、水素原子又はメチル基であり、Ｒ2～Ｒ6はそれぞれ独立して水素原子又は炭素数が１～２２であるアルキル基である。Ｒ2～Ｒ6は同一であっても相違してもよい。 However, R 1 is a hydrogen atom or a methyl group, and R 2 to R 6 are each independently a hydrogen atom or an alkyl group having 1 to 22 carbon atoms. R 2 to R 6 may be the same or different.
　Ｒ2～Ｒ6としては、例えば、メチル基、エチル基、ｎ－プロピル基、イソプロピル基、ブチル基、ペンチル基、ヘキシル基、オクチル基、ノニル基、デシル基、ウンデシル基、ドデシル基、テトラデシル基、ヘキサデシル基、エイコシル基などが挙げられる。 Examples of R 2 to R 6 include methyl group, ethyl group, n-propyl group, isopropyl group, butyl group, pentyl group, hexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tetradecyl group. , Hexadecyl group, eicosyl group and the like.
　ベンジル（メタ）アクリレート系モノマーは、Ｒ1が水素原子又はメチル基であり、且つ、Ｒ2～Ｒ6が水素原子であることが好ましく、Ｒ1～Ｒ6が水素原子であることがより好ましい。即ち、ベンジル（メタ）アクリレート系モノマーは、ベンジル（メタ）アクリレートが好ましく、ベンジルアクリレートがより好ましい。 In the benzyl (meth)acrylate-based monomer, R 1 is preferably a hydrogen atom or a methyl group, R 2 to R 6 are preferably hydrogen atoms, and R 1 to R 6 are more preferably hydrogen atoms. .. That is, the benzyl (meth)acrylate-based monomer is preferably benzyl (meth)acrylate, and more preferably benzyl acrylate.
　重合体ブロックＡを構成しているモノマー単位中において、ベンジル（メタ）アクリレート系モノマー単位の含有量は、６０質量％以上が好ましく、９０質量％以上がより好ましく、９８質量％以上が特に好ましい。ベンジル（メタ）アクリレート系モノマーの含有量は、９９質量％以下がより好ましい。ベンジル（メタ）アクリレート系モノマー単位の含有量が上記範囲内であると、架橋性ブロック共重合体の塗工性及び熱安定性が向上すると共に、架橋性ブロック共重合体の架橋後における耐剥がれ性などの粘着性が向上する。 In the monomer unit constituting the polymer block A, the content of the benzyl (meth)acrylate-based monomer unit is preferably 60% by mass or more, more preferably 90% by mass or more, and particularly preferably 98% by mass or more. The content of the benzyl (meth)acrylate-based monomer is more preferably 99% by mass or less. When the content of the benzyl (meth)acrylate-based monomer unit is within the above range, coating property and thermal stability of the crosslinkable block copolymer are improved, and peeling resistance of the crosslinkable block copolymer after crosslinking is improved. The adhesiveness such as the property is improved.
　重合体ブロックＡを構成しているモノマー単位中において、紫外線架橋性を有しないモノマー単位の含有量は、架橋性ブロック共重合体の架橋後における耐剥がれ性が向上するので、６０質量％以上が好ましく、９０質量％以上がより好ましく、９８質量％以上が特に好ましい。重合体ブロックＡを構成しているモノマー単位中において、紫外線架橋性を有しないモノマー単位の含有量は、９９質量％以下がより好ましい。 In the monomer unit constituting the polymer block A, the content of the monomer unit having no ultraviolet crosslinking property is 60% by mass or more because the peel resistance after crosslinking of the crosslinkable block copolymer is improved. 90 mass% or more is more preferable, and 98 mass% or more is particularly preferable. In the monomer units constituting the polymer block A, the content of the monomer unit having no UV crosslinking property is more preferably 99% by mass or less.
　重合体ブロックＡは、後述する重合体ブロックＢの両末端に結合しており、架橋性ブロック共重合体は、Ａ－Ｂ－Ａ型のトリブロック構造を有している。重合体ブロックＢの両末端に結合している２個の重合体ブロックＡは、同一である必要はなく相違していてもよい。即ち、重合体ブロックＢの両末端に結合している２個の重合体ブロックＡは、これを構成しているモノマー単位の種類及び含有量は同一であっても相違していてもよいし、分子量が同一であっても相違していてもよい。 The polymer block A is bonded to both ends of the polymer block B described later, and the crosslinkable block copolymer has an ABA type triblock structure. The two polymer blocks A bonded to both ends of the polymer block B do not have to be the same and may be different. That is, in the two polymer blocks A bonded to both ends of the polymer block B, the type and content of the monomer units constituting the two polymer blocks A may be the same or different, The molecular weights may be the same or different.
　重合体ブロックＡを構成している重合体の分子量は、１０００以上が好ましく、３０００以上がより好ましく、５０００以上がより好ましい。重合体ブロックＡを構成している重合体の分子量は、５００００以下が好ましく、３００００以下がより好ましく、２００００以下がより好ましい。重合体ブロックＡを構成している重合体の分子量が１０００以上であると、架橋性ブロック共重合体は架橋後において優れた耐剥がれ性を有する。重合体ブロックＡを構成している重合体の分子量が５００００以下であると、架橋性ブロック共重合体は適度な溶融粘度を有して優れた塗工性を有している。 The molecular weight of the polymer constituting the polymer block A is preferably 1,000 or more, more preferably 3,000 or more, and even more preferably 5,000 or more. The polymer constituting the polymer block A has a molecular weight of preferably 50,000 or less, more preferably 30,000 or less, and further preferably 20,000 or less. When the molecular weight of the polymer constituting the polymer block A is 1,000 or more, the crosslinkable block copolymer has excellent peel resistance after crosslinking. When the molecular weight of the polymer constituting the polymer block A is 50,000 or less, the crosslinkable block copolymer has an appropriate melt viscosity and excellent coatability.
　重合体ブロックＢの両末端に結合している２個の重合体ブロックＡの分子量の比は、２．０以下が好ましく、１．８以下がより好ましく、１．６以下が特に好ましい。分子量の比が上記範囲内であると、架橋性ブロック共重合体の架橋後において、重合体ブロックＡと重合体ブロックＢとの間で層分離構造を良好に形成することができ、架橋性ブロック共重合体の架橋後の耐剥がれ性が向上する。なお、分子量の比は、２個の重合体ブロックＡ、Ａの分子量のうち、大きい方の分子量を小さい方の分子量で除した値をいう。 The ratio of the molecular weights of the two polymer blocks A bonded to both ends of the polymer block B is preferably 2.0 or less, more preferably 1.8 or less, and particularly preferably 1.6 or less. When the molecular weight ratio is within the above range, a layer separation structure can be satisfactorily formed between the polymer block A and the polymer block B after the crosslinking of the crosslinkable block copolymer, and thus the crosslinkable block. The peel resistance of the copolymer after crosslinking is improved. The ratio of the molecular weights is a value obtained by dividing the larger molecular weight of the two polymer blocks A and A by the smaller molecular weight.
　なお、本発明において、重合体ブロックＡを構成している重合体の分子量は、重合体ブロックＡ部分重合物のピークトップ分子量と、架橋性ブロック共重合体のピークトップ分子量から重合体ブロックＡ－重合体ブロックＢ部分重合物のピークトップ分子量を引いた値とをいう。 In the present invention, the molecular weight of the polymer constituting the polymer block A is determined from the peak top molecular weight of the partial polymer of the polymer block A and the peak top molecular weight of the crosslinkable block copolymer. The value obtained by subtracting the peak top molecular weight of the polymer block B partial polymer.
　架橋性ブロック共重合体の重合体ブロックＢを構成しているモノマーは、紫外線架橋性を有しないこと（紫外線非架橋性であること）が好ましい。即ち、重合体ブロックＢの重合体ブロックＢを構成しているモノマーは、紫外線架橋性基を含有しないモノマー（紫外線非架橋性モノマー）であることが好ましい。重合体ブロックＢを構成しているモノマーが架橋性を有していないと、架橋性ブロック共重合体の架橋後における耐剥がれ性が向上する。 The monomer forming the polymer block B of the crosslinkable block copolymer preferably has no UV crosslinking property (UV noncrosslinking property). That is, it is preferable that the monomer constituting the polymer block B of the polymer block B is a monomer not containing an ultraviolet crosslinking group (an ultraviolet noncrosslinking monomer). When the monomer constituting the polymer block B has no crosslinkability, the peeling resistance of the crosslinkable block copolymer after crosslinking is improved.
　架橋性ブロック共重合体の重合体ブロックＢを構成しているモノマーとしては、特に限定されず、ラジカル重合、カチオン重合又はアニオン重合などの重合反応し得るモノマーが挙げられ、エチレン性不飽和結合を有するモノマーが好ましい。 The monomer constituting the polymer block B of the crosslinkable block copolymer is not particularly limited, and examples thereof include a monomer capable of undergoing a polymerization reaction such as radical polymerization, cationic polymerization or anionic polymerization, and an ethylenically unsaturated bond. The monomers having are preferred.
　重合体ブロックＢを構成しているモノマーとしては、例えば、ビニル系モノマー、（メタ）アクリル系モノマー、（メタ）アクリルアミド系モノマーなどが挙げられ、ラジカル重合反応性に優れているので、（メタ）アクリル系モノマー及び（メタ）アクリルアミド系モノマーが好ましい。なお、（メタ）アクリルとは、アクリル又はメタクリルを意味する。 Examples of the monomer constituting the polymer block B include a vinyl-based monomer, a (meth)acrylic-based monomer, a (meth)acrylamide-based monomer, and the like. Since they have excellent radical polymerization reactivity, (meth) Acrylic monomers and (meth)acrylamide monomers are preferred. In addition, (meth)acryl means acryl or methacryl.
　ビニル系モノマーとしては、例えば、スチレン、ｏ－メチルスチレン、ｍ－メチルスチレン、ｐ－メチルスチレン、α－メチルスチレン、ｏ－エチルスチレン、ｍ－エチルスチレン、ｐ－エチルスチレン、２，４－ジメチルスチレン、ｐ－ｎ－ブチルスチレン、ｐ－ｔ－ブチルスチレン、ｐ－ｎ－ヘキシルスチレン、ｐ－ｎ－オクチルスチレン、ｐ－ｎ－ノニルスチレン、ｐ－ｎ－デシルスチレン、ｐ－ｎ－ドデシルスチレン、ｐ－メトキシスチレン、ｐ－フェニルスチレン、ｐ－クロロスチレン、３，４－ジクロロスチレンなどのスチレン系モノマーなどが挙げられる。なお、ビニル系モノマーは、単独で用いられても二種以上が併用されてもよい。 Examples of vinyl monomers include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene and 2,4-dimethyl. Styrene, pn-butylstyrene, pt-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene And styrene-based monomers such as p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, and 3,4-dichlorostyrene. The vinyl monomers may be used alone or in combination of two or more kinds.
　（メタ）アクリル系モノマーとしては、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、ｎ－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、ｓｅｃ－ブチル（メタ）アクリレート、ｎ－ヘキシル（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、イソオクチル（メタ）アクリレート、ｎ－ノニル（メタ）アクリレート、イソノニル（メタ）アクリレート、ｎ－デシル（メタ）アクリレート、ラウリル（メタ）メタクリレート、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、３－ヒドロキシプロピル（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、４－ヒドロキシブチル（メタ）アクリレート、ベンジル（メタ）アクリレート、イソボルニル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、３，５，５－トリメチルシクロヘキシル（メタ）アクリレート、フェニル（メタ）アクリレート、ジシクロペンタニル（メタ）アクリレート、ジシクロペンテニル（メタ）アクリレート、アダマンチル（メタ）アクリレートなどのアクリレート、（メタ）アクリル酸などが挙げられ、架橋性ブロック共重合体は適度な溶融粘度を有して優れた塗工性を有し且つ架橋後において耐剥がれ性などの粘着物性に優れているので、アルキル基の炭素数が１～１２であるアルキル（メタ）アクリレートが好ましく、アルキル基の炭素数が２～１０であるアルキル（メタ）アクリレートがより好ましく、アルキル基の炭素数が４～８であるアルキル（メタ）アクリレートが特に好ましい。なお、（メタ）アクリル系モノマーは、単独で用いられても二種以上が併用されてもよい。 Examples of the (meth)acrylic monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth). ) Acrylate, n-hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, n-octyl(meth)acrylate, isooctyl(meth)acrylate, n-nonyl(meth)acrylate, isononyl(meth)acrylate, n-decyl (Meth)acrylate, lauryl (meth)methacrylate, stearyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth ) Acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, 3,5,5-trimethylcyclohexyl (meth)acrylate, phenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, di Examples thereof include acrylates such as cyclopentenyl (meth)acrylate and adamantyl (meth)acrylate, and (meth)acrylic acid. The crosslinkable block copolymer has an appropriate melt viscosity and excellent coatability. Alkyl (meth)acrylates having an alkyl group with 1 to 12 carbon atoms are preferred because they have excellent adhesive properties such as peel resistance after crosslinking, and alkyl (meth) with an alkyl group with 2 to 10 carbon atoms Acrylate is more preferred, and alkyl(meth)acrylate in which the alkyl group has 4 to 8 carbon atoms is particularly preferred. The (meth)acrylic monomers may be used alone or in combination of two or more.
　（メタ）アクリルアミド系モノマーとしては、例えば、Ｎ，Ｎ－ジメチル（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、２－ヒドロキシエチル（メタ）アクリルアミド、Ｎ－フェニル（メタ）アクリルアミド、Ｎ－ベンジル（メタ）アクリルアミド、Ｎ－イソボルニル（メタ）アクリルアミド、Ｎ－シクロヘキシル（メタ）アクリルアミド、Ｎ－３，５，５－トリメチルシクロヘキシル（メタ）アクリルアミド、Ｎ－ジシクロペンタニル（メタ）アクリルアミド、Ｎ－ジシクロペンテニル（メタ）アクリルアミド、Ｎ－アダマンチル（メタ）アクリルアミド、Ｎ，Ｎ－ジフェニル（メタ）アクリルアミドなどが挙げられる。なお、（メタ）アクリルアミド系モノマーは、単独で用いられても二種以上が併用されてもよい。 Examples of the (meth)acrylamide-based monomer include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, 2-hydroxyethyl(meth)acrylamide, N- Phenyl(meth)acrylamide, N-benzyl(meth)acrylamide, N-isobornyl(meth)acrylamide, N-cyclohexyl(meth)acrylamide, N-3,5,5-trimethylcyclohexyl(meth)acrylamide, N-dicyclopenta Examples thereof include nyl(meth)acrylamide, N-dicyclopentenyl(meth)acrylamide, N-adamantyl(meth)acrylamide, N,N-diphenyl(meth)acrylamide and the like. The (meth)acrylamide-based monomers may be used alone or in combination of two or more kinds.
　架橋性ブロック共重合体の重合体ブロックＢを構成しているモノマーは、カルボキシ基含有モノマー単位を含有していることが好ましい。カルボキシ基含有モノマーとしては、特に限定されず、例えば、アクリル酸、メタクリル酸、β－カルボキシエチルアクリレート、β－カルボキシエチルメタクリレート、マレイン酸、フマル酸などが挙げられ、メタクリル酸及びアクリル酸が好ましい。 The monomer constituting the polymer block B of the crosslinkable block copolymer preferably contains a carboxy group-containing monomer unit. The carboxy group-containing monomer is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, β-carboxyethyl acrylate, β-carboxyethyl methacrylate, maleic acid, fumaric acid, and the like, with methacrylic acid and acrylic acid being preferred.
　重合体ブロックＢを構成しているモノマー単位中において、カルボキシ基含有モノマー単位の含有量は、０．１質量％以上が好ましく、０．５質量％以上がより好ましく、１質量％以上がより好ましく、２質量％以上がより好ましく、２．５質量％以上がより好ましい。重合体ブロックＢを構成しているモノマー単位中において、カルボキシ基含有モノマー単位の含有量は、２５質量％以下が好ましく、２３質量％以下がより好ましく、２０質量％以下がより好ましく、１０質量％以下がより好ましく、５質量％以下がより好ましい。カルボキシ基含有モノマーの含有量が０．１質量％以上であると、架橋性ブロック共重合体の架橋後における耐剥がれ性が向上する。カルボキシ基含有モノマーの含有量が２５質量％以下であると、架橋性ブロック共重合体の塗工性が向上する。 In the monomer unit constituting the polymer block B, the content of the carboxy group-containing monomer unit is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and further preferably 1% by mass or more. 2 mass% or more is more preferable, and 2.5 mass% or more is more preferable. In the monomer unit constituting the polymer block B, the content of the carboxy group-containing monomer unit is preferably 25% by mass or less, more preferably 23% by mass or less, more preferably 20% by mass or less, and 10% by mass. The following is more preferable, and 5% by mass or less is more preferable. When the content of the carboxy group-containing monomer is 0.1% by mass or more, the peeling resistance of the crosslinkable block copolymer after crosslinking is improved. When the content of the carboxy group-containing monomer is 25 mass% or less, the coatability of the crosslinkable block copolymer is improved.
　重合体ブロックＢを構成しているモノマーと、重合体ブロックＡを構成しているモノマーのうちの紫外線架橋性を有しないモノマーとは、同一であっても相違していてもよい。 The monomer that constitutes the polymer block B and the monomer that does not have ultraviolet crosslinking property among the monomers that constitute the polymer block A may be the same or different.
　重合体ブロックＢを構成している重合体のガラス転移温度は、０℃（２７３．１５Ｋ（ケルビン））以下が好ましく、－２０℃（２５３．１５Ｋ）以下がより好ましく、－３０℃（２４３．１５Ｋ）以下がより好ましく、－４０℃（２３３．１５Ｋ）以下が特に好ましい。重合体のガラス転移温度が０℃以下であると、架橋性ブロック共重合体の架橋後の耐剥がれ性が向上する。重合体ブロックＢを構成している重合体のガラス転移温度は、－８０℃（１９３．１５Ｋ）以上が好ましく、－７０℃（２０３．１５Ｋ）以上がより好ましく、－６０℃（２１３．１５Ｋ）以上が特に好ましい。重合体のガラス転移温度が－８０℃以上であると、架橋性ブロック共重合体の架橋後の耐剥がれ性が向上する。 The glass transition temperature of the polymer constituting the polymer block B is preferably 0° C. (273.15K (Kelvin)) or lower, more preferably −20° C. (253.15K) or lower, and −30° C. (243. 15 K) or less is more preferable, and −40° C. (233.15 K) or less is particularly preferable. When the glass transition temperature of the polymer is 0° C. or lower, the peel resistance of the crosslinkable block copolymer after crosslinking is improved. The glass transition temperature of the polymer constituting the polymer block B is preferably −80° C. (193.15K) or higher, more preferably −70° C. (203.15K) or higher, and −60° C. (213.15K). The above is particularly preferable. When the glass transition temperature of the polymer is −80° C. or higher, peeling resistance of the crosslinkable block copolymer after crosslinking is improved.
　なお、重合体ブロックＢを構成する重合体のガラス転移温度（ケルビン）は、例えば、下記式（Ｆｏｘの式）に基づいて算出される。 The glass transition temperature (Kelvin) of the polymer constituting the polymer block B is calculated, for example, based on the following formula (Fox's formula).
Figure JPOXMLDOC01-appb-M000002
　但し、
　Ｔｇは、重合体ブロックＢを構成している重合体のガラス転移温度（Ｋ、ケルビン）である。
　ｍは、重合体ブロックＢを構成している重合体について、この重合体を構成しているモノマーの種類の数であり、自然数である。
　Ｔｇｎは、重合体ブロックＢを構成している重合体について、この重合体を構成しているｎ番目のモノマーのホモ重合体が有するガラス転移温度（Ｋ、ケルビン）である。
　Ｗｎは、重合体ブロックＢを構成している重合体について、この重合体を構成しているｎ番目のモノマーの含有量（質量％）である。
Figure JPOXMLDOC01-appb-M000002
However,
Tg is the glass transition temperature (K, Kelvin) of the polymer constituting the polymer block B.
m is the number of kinds of monomers constituting the polymer in the polymer constituting the polymer block B and is a natural number.
Tgn is a glass transition temperature (K, Kelvin) of a polymer constituting the polymer block B, which a homopolymer of the n-th monomer constituting the polymer has.
Wn is the content (mass %) of the n-th monomer constituting the polymer of the polymer constituting the polymer block B.
　なお、Ｔｇｎは、ＪＩＳ　Ｋ７１２１に準拠してＤＳＣ測定を行い、１０℃／分の速度で加熱と冷却を行った後、１０℃／分の速度条件下の第２ランにおいて測定されたＤＳＣ曲線の段差の中間点の温度とする。 In addition, Tgn was measured by DSC in accordance with JIS K7121, and after heating and cooling at a rate of 10°C/min, the DSC curve measured in the second run under a rate condition of 10°C/min. The temperature is at the midpoint of the step.
　架橋性ブロック共重合体において、重合体ブロックＡの総含有量は、５質量％以上が好ましく、１０質量％以上がより好ましく、１５質量％以上がより好ましい。重合体ブロックＡの総含有量が上記範囲内であると、架橋性ブロック共重合体は適度な溶融粘度を有して優れた塗工性を有していると共に、架橋性ブロック共重合体は架橋後において優れた耐剥がれ性を有する。架橋性ブロック共重合体において、重合体ブロックＡの総含有量は、３９質量％以下が好ましく、３０質量％以下がより好ましく、２５質量％以下が特に好ましい。重合体ブロックＡの総含有量が上記範囲内であると、架橋性ブロック共重合体は適度な溶融粘度を有して優れた塗工性を有していると共に、架橋性ブロック共重合体は架橋後において優れた耐剥がれ性を有する。 In the crosslinkable block copolymer, the total content of the polymer block A is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more. When the total content of the polymer block A is within the above range, the crosslinkable block copolymer has appropriate melt viscosity and excellent coatability, and at the same time, the crosslinkable block copolymer is It has excellent peeling resistance after crosslinking. In the crosslinkable block copolymer, the total content of the polymer block A is preferably 39% by mass or less, more preferably 30% by mass or less, and particularly preferably 25% by mass or less. When the total content of the polymer block A is within the above range, the crosslinkable block copolymer has appropriate melt viscosity and excellent coatability, and at the same time, the crosslinkable block copolymer is It has excellent peeling resistance after crosslinking.
　架橋性ブロック共重合体において、重合体ブロックＢの含有量は、６１質量％以上が好ましく、７０質量％以上がより好ましく、７５質量％以上がより好ましい。重合体ブロックＢの総含有量が上記範囲内であると、架橋性ブロック共重合体は適度な溶融粘度を有して優れた塗工性を有していると共に、架橋性ブロック共重合体は架橋後において優れた耐剥がれ性を有する。架橋性ブロック共重合体において、重合体ブロックＢの含有量は、９５質量％以下が好ましく、９０質量％以下がより好ましく、８５質量％以下がより好ましい。重合体ブロックＢの総含有量が上記範囲内であると、架橋性ブロック共重合体は適度な溶融粘度を有して優れた塗工性を有していると共に、架橋性ブロック共重合体は架橋後において優れた耐剥がれ性を有する。 In the crosslinkable block copolymer, the content of the polymer block B is preferably 61% by mass or more, more preferably 70% by mass or more, and further preferably 75% by mass or more. When the total content of the polymer block B is within the above range, the crosslinkable block copolymer has an appropriate melt viscosity and excellent coatability, and at the same time, the crosslinkable block copolymer is It has excellent peeling resistance after crosslinking. In the crosslinkable block copolymer, the content of the polymer block B is preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 85% by mass or less. When the total content of the polymer block B is within the above range, the crosslinkable block copolymer has an appropriate melt viscosity and excellent coatability, and at the same time, the crosslinkable block copolymer is It has excellent peeling resistance after crosslinking.
　重合体ブロックＢを構成している重合体の分子量は、５０００以上が好ましく、３００００以上がより好ましく、５００００以上が特に好ましい。重合体ブロックＢを構成している重合体の分子量は、４０００００以下が好ましく、２４００００以下がより好ましく、１５００００以下が特に好ましい。重合体ブロックＢを構成している重合体の分子量が５０００以上であると、架橋性ブロック共重合体は架橋後において優れた耐剥がれ性を有する。重合体ブロックＡを構成している重合体の分子量が４０００００以下であると、架橋性ブロック共重合体は、適度な溶融粘度を有し、優れた塗工性を有している。 The molecular weight of the polymer constituting the polymer block B is preferably 5,000 or more, more preferably 30,000 or more, particularly preferably 50,000 or more. The molecular weight of the polymer constituting the polymer block B is preferably 400000 or less, more preferably 240000 or less, and particularly preferably 150,000 or less. When the molecular weight of the polymer constituting the polymer block B is 5,000 or more, the crosslinkable block copolymer has excellent peel resistance after crosslinking. When the molecular weight of the polymer constituting the polymer block A is 400000 or less, the crosslinkable block copolymer has an appropriate melt viscosity and excellent coatability.
　架橋性ブロック共重合体において、重合体ブロックＡを構成している重合体の分子量と重合体ブロックＢを構成している重合体の分子量との比（重合体ブロックＡを構成している重合体の分子量／重合体ブロックＢを構成している重合体の分子量）は、０．０３以上が好ましく、０．０５以上がより好ましく、０．０８以上が特に好ましい。架橋性ブロック共重合体において、重合体ブロックＡを構成している重合体の分子量と重合体ブロックＢを構成している重合体の分子量との比（重合体ブロックＡを構成している重合体の分子量／重合体ブロックＢを構成している重合体の分子量）は、０．３２以下が好ましく、０．２２以下がより好ましく、０．１７以下が特に好ましい。重合体ブロックＡを構成している重合体の分子量と重合体ブロックＢを構成している重合体の分子量との比が０．０３以上であると、架橋性ブロック共重合体は架橋後において優れた耐剥がれ性を有する。重合体ブロックＡを構成している重合体の分子量と重合体ブロックＢを構成している重合体の分子量との比が０．３２以下であると、架橋性ブロック共重合体は適度な溶融粘度を有し、優れた塗工性を有する。なお、重合体ブロックＡを構成している重合体の分子量は、重合体ブロックＢの両末端に結合している重合体ブロックＡを構成している重合体の分子量の相加平均値をいう。 In the crosslinkable block copolymer, the ratio of the molecular weight of the polymer constituting the polymer block A to the molecular weight of the polymer constituting the polymer block B (the polymer constituting the polymer block A (Molecular weight/molecular weight of the polymer constituting the polymer block B) is preferably 0.03 or more, more preferably 0.05 or more, and particularly preferably 0.08 or more. In the crosslinkable block copolymer, the ratio of the molecular weight of the polymer constituting the polymer block A to the molecular weight of the polymer constituting the polymer block B (the polymer constituting the polymer block A (Molecular weight/molecular weight of the polymer constituting the polymer block B) is preferably 0.32 or less, more preferably 0.22 or less, and particularly preferably 0.17 or less. When the ratio of the molecular weight of the polymer forming the polymer block A to the molecular weight of the polymer forming the polymer block B is 0.03 or more, the crosslinkable block copolymer is excellent after crosslinking. Has peeling resistance. When the ratio of the molecular weight of the polymer constituting the polymer block A and the molecular weight of the polymer constituting the polymer block B is 0.32 or less, the crosslinkable block copolymer has an appropriate melt viscosity. And has excellent coatability. The molecular weight of the polymer constituting the polymer block A means the arithmetic average value of the molecular weights of the polymers constituting the polymer block A bonded to both ends of the polymer block B.
　なお、本発明において、重合体ブロックＢを構成している重合体の分子量は下記の要領で算出された値をいう。リビング重合を活性化しうる構造（例えば、交換連鎖反応部位など）を１分子当たり１個有する化合物を用いて重合された架橋性ブロック共重合体の場合、重合体ブロックＢを構成している重合体の分子量は、重合体ブロックＡ－重合体ブロックＢ部分重合物のピークトップ分子量から、重合体ブロックＡ部分重合物のピークトップ分子量を引いた値をいう。リビング重合を活性化しうる構造（例えば、交換連鎖反応部位など）を１分子当たり２個有する化合物を用いて重合された架橋性ブロック共重合体の場合、重合体ブロックＢを構成している重合体の分子量は、架橋性ブロック共重合体のピークトップ分子量から重合体ブロックＡ部分重合物のピークトップ分子量を引いた値をいう。 In the present invention, the molecular weight of the polymer constituting the polymer block B means the value calculated according to the following procedure. In the case of a crosslinkable block copolymer polymerized with a compound having one structure (for example, exchange chain reaction site) capable of activating living polymerization per molecule, the polymer constituting the polymer block B The molecular weight of is a value obtained by subtracting the peak top molecular weight of the polymer block A partial polymer from the peak top molecular weight of the polymer block A-polymer block B partial polymer. In the case of a crosslinkable block copolymer polymerized using a compound having two structures per molecule that can activate living polymerization (for example, exchange chain reaction sites), the polymer constituting the polymer block B Is the value obtained by subtracting the peak top molecular weight of the polymer block A partial polymer from the peak top molecular weight of the crosslinkable block copolymer.
　架橋性ブロック共重合体の重量平均分子量（Ｍｗ）は、１００００以上が好ましく、５００００以上がより好ましく、７００００以上がより好ましく、８００００以上がより好ましい。架橋性ブロック共重合体の重量平均分子量（Ｍｗ）は、５０００００以下が好ましく、３０００００以下がより好ましく、２５００００以下がより好ましく、２０００００以下がより好ましい。重量平均分子量（Ｍｗ）が１００００以上であると、架橋性ブロック共重合体の耐剥がれ性が向上する。重量平均分子量（Ｍｗ）が５０００００以下であると、架橋性ブロック共重合体は適度な溶融粘度を有し、優れた塗工性を有する。 The weight average molecular weight (Mw) of the crosslinkable block copolymer is preferably 10,000 or more, more preferably 50,000 or more, more preferably 70,000 or more, and more preferably 80,000 or more. The weight average molecular weight (Mw) of the crosslinkable block copolymer is preferably 500,000 or less, more preferably 300,000 or less, more preferably 250,000 or less, and more preferably 200,000 or less. When the weight average molecular weight (Mw) is 10,000 or more, the peeling resistance of the crosslinkable block copolymer is improved. When the weight average molecular weight (Mw) is 500000 or less, the crosslinkable block copolymer has an appropriate melt viscosity and excellent coatability.
　架橋性ブロック共重合体の分散度（重量平均分子量Ｍｗ／数平均分子量Ｍｎ）は、３．０以下が好ましく、２．５以下がより好ましく、２．０以下が特に好ましい。分散度が３．０以下であると、架橋性ブロック共重合体は架橋後において優れた耐剥がれ性を有する。 The dispersity (weight average molecular weight Mw/number average molecular weight Mn) of the crosslinkable block copolymer is preferably 3.0 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. When the dispersity is 3.0 or less, the crosslinkable block copolymer has excellent peel resistance after crosslinking.
　架橋性ブロック共重合体の重合体ブロックを構成している重合体の分子量、並びに、架橋性ブロック共重合体の重量平均分子量及び数平均分子量は、ＧＰＣ（ゲルパーミエーションクロマトグラフィー）法によって測定されたポリスチレン換算した値である。具体的には、架橋性ブロック共重合体０．０１ｇを採取し、採取した架橋性ブロック共重合体を試験管に供給した上で、試験管にＴＨＦ（テトラヒドロフラン）を加えて架橋性ブロック共重合体を５００倍に希釈し、フィルタリングを行って、測定試料を作製する。 The molecular weight of the polymer constituting the polymer block of the crosslinkable block copolymer, and the weight average molecular weight and number average molecular weight of the crosslinkable block copolymer are measured by GPC (gel permeation chromatography) method. It is a value converted into polystyrene. Specifically, 0.01 g of the crosslinkable block copolymer was collected, the collected crosslinkable block copolymer was supplied to a test tube, and THF (tetrahydrofuran) was added to the test tube to add the crosslinkable block copolymer. The combined sample is diluted 500 times and filtered to prepare a measurement sample.
　この測定試料を用いてＧＰＣ法によって、架橋性ブロック共重合体の重合体ブロックを構成している重合体の分子量、並びに、架橋性ブロック共重合体の重量平均分子量Ｍｗ及び数平均分子量Ｍｎを測定することができる。 Using this measurement sample, the molecular weight of the polymer constituting the polymer block of the crosslinkable block copolymer, and the weight average molecular weight Mw and the number average molecular weight Mn of the crosslinkable block copolymer were measured by the GPC method. can do.
　架橋性ブロック共重合体の重合体ブロックを構成している重合体の分子量、並びに、架橋性ブロック共重合体の重量平均分子量Ｍｗ及び数平均分子量Ｍｎは、例えば、下記測定装置及び測定条件にて測定することができる。
測定装置　Ｗａｔｅｒｓ社製　ＡＣＱＵＩＴＹ　ＡＰＣシステム
測定条件　カラム：Ｗａｔｅｒｓ社製　ＨＳＰｇｅｌ（ＴＭ）ＨＲ　ＭＢ－Ｍ
　　　　　移動相：テトラヒドロフラン使用　０．５ｍＬ／分
　　　　　検出器：ＲＩ検出器
　　　　　標準物質：ポリスチレン
　　　　　ＳＥＣ温度：４０℃ The molecular weight of the polymer constituting the polymer block of the crosslinkable block copolymer, and the weight average molecular weight Mw and the number average molecular weight Mn of the crosslinkable block copolymer are, for example, in the following measurement device and measurement conditions. Can be measured.
Measuring apparatus Waters ACQUITY APC system Measurement conditions Column: Waters HSPgel(TM) HR MB-M
Mobile phase: using tetrahydrofuran 0.5 mL/min Detector: RI detector Standard substance: polystyrene SEC temperature: 40°C
　架橋性ブロック共重合体は、Ａ－Ｂ－Ａ型トリブロック共重合体であり、硬質成分は、重合体ブロックＡ及びＢのうちのガラス転移温度の高い重合体ブロックによって主に構成される一方、軟質成分は、重合体ブロックＡ及びＢのうちのガラス転移温度の低い重合体ブロックによって主に構成される。 The crosslinkable block copolymer is an ABA type triblock copolymer, and the hard component is mainly composed of one of the polymer blocks A and B having a high glass transition temperature. The soft component is mainly composed of one of the polymer blocks A and B having a low glass transition temperature.
　硬質成分を主に重合体ブロックＡによって構成し且つ軟質成分を主に重合体ブロックＢによって構成すると共に、重合体ブロックＡに積極的に架橋構造を導入することによって、架橋性ブロック共重合体に適度な硬さを付与しつつ、架橋性ブロック共重合体を架橋させて得られるブロック共重合体の重合体ブロックＡ及びＢ間の極性差に起因した層分離構造を良好に形成することができ、架橋性ブロック共重合体を架橋させて得られるブロック共重合体に優れた耐剥がれ性を付与することができ好ましい。 By forming the hard component mainly by the polymer block A and the soft component mainly by the polymer block B, and by positively introducing a crosslinked structure into the polymer block A, a crosslinkable block copolymer is obtained. It is possible to favorably form a layer separation structure due to the polarity difference between the polymer blocks A and B of the block copolymer obtained by crosslinking the crosslinkable block copolymer while imparting appropriate hardness. The block copolymer obtained by crosslinking the crosslinkable block copolymer can impart excellent peeling resistance, which is preferable.
　重合体ブロックＢを構成する紫外線架橋性を有しないモノマーとしてカルボキシ基含有モノマーを含有させることによって、架橋性ブロック共重合体を架橋させて得られるブロック共重合体はより優れた耐剥がれ性を有する。 A block copolymer obtained by crosslinking a crosslinkable block copolymer by incorporating a carboxy group-containing monomer as a monomer that does not have ultraviolet crosslinkability constituting the polymer block B has more excellent peeling resistance. ..
　次に、架橋性ブロック共重合体の製造方法を説明する。架橋性ブロック共重合体は、汎用の重合方法を用いて製造することができるが、リビング重合を用いて製造することが好ましい。 Next, the method for producing the crosslinkable block copolymer will be described. The crosslinkable block copolymer can be produced using a general-purpose polymerization method, but it is preferable to produce it using living polymerization.
　リビング重合は、例えば、リビングラジカル重合、リビングカチオン重合、リビングアニオン重合が挙げられるが、高い汎用性と重合反応の安全性の点からリビングラジカル重合が好ましい。 Examples of living polymerization include living radical polymerization, living cationic polymerization, and living anionic polymerization, but living radical polymerization is preferable from the viewpoint of high versatility and safety of polymerization reaction.
　リビングラジカル重合法としては、例えば、イニファーター重合、ニトロキシド介在重合（ＮＭＰ）、遷移金属触媒による原子移動ラジカル付加重合（ＡＴＲＰ）、ジチオエステル化合物による可逆的連鎖移動重合（ＲＡＦＴ）、有機テルル化合物による重合（ＴＥＲＰ）、有機化合物触媒による可逆移動触媒重合（ＲＴＣＰ）、可逆配位媒介重合（ＲＣＭＰ）などが挙げられる。 Examples of the living radical polymerization method include iniferter polymerization, nitroxide-mediated polymerization (NMP), transition metal-catalyzed atom transfer radical addition polymerization (ATRP), dithioester compound reversible chain transfer polymerization (RAFT), and organic tellurium compound. Polymerization (TERP), reversible transfer catalytic polymerization (RTCP) using an organic compound catalyst, reversible coordination-mediated polymerization (RCMP), etc.
　特に、可逆的連鎖移動重合（ＲＡＦＴ）は、（１）モノマー汎用性が高いこと、（２）酸素及び光に対して極端な反応性低下を生じないこと、（３）極端な低温又は高温でなくても反応が進行することから簡便な重合反応環境で実施可能でき高い生産性を有すること、（４）金属及びハロゲンなどの毒物を使用しないこと、（５）十分な分子量を有する架橋性ブロック共重合体を製造できることから好ましい。 In particular, reversible chain transfer polymerization (RAFT) is (1) highly versatile in monomers, (2) does not cause an extreme decrease in reactivity to oxygen and light, and (3) at extremely low or high temperatures. Since the reaction proceeds even without it, it can be carried out in a simple polymerization reaction environment and has high productivity, (4) no poisons such as metals and halogens are used, and (5) a crosslinkable block having a sufficient molecular weight. It is preferable because a copolymer can be produced.
　可逆的連鎖移動重合（ＲＡＦＴ）を実施するために用いられるジチオエステル化合物としては、交換連鎖反応性を有するジチオエステル化合物であれば、特に限定されず、例えば、ジチオベンゾエート化合物、トリチオカーボネート化合物、ジチオカルバメート化合物、キサンテート化合物などが挙げられ、トリチオカーボネート化合物が好ましい。 The dithioester compound used for carrying out the reversible chain transfer polymerization (RAFT) is not particularly limited as long as it is a dithioester compound having exchange chain reactivity, and examples thereof include a dithiobenzoate compound, a trithiocarbonate compound, Examples thereof include dithiocarbamate compounds and xanthate compounds, with trithiocarbonate compounds being preferred.
　トリチオカーボネート化合物としては、特に限定されないが、例えば、２－［（ドデシルスルファニルチオカルボニル）スルファニル］プロパン酸、４－｛［（２－カルボキシエチル）スルファニルチオカルボニル］スルファニル｝プロパン酸、４－シアノ－４－［（ドデシルスルファニルチオカルボニル）スルファニル］ペンタン酸、４－［（２－カルボキシエチルスルファニルチオカルボニル）スルファニル］－４－シアノペンタン酸などの交換連鎖反応部位を１個のみ有するトリチオカーボネート化合物、Ｓ，Ｓ－ジベンジルトリチオカーボネート、ビス｛４－［エチル－（２－ヒドロキシエチル）カルバモイル］ベンジル｝トリチオカーボネートなどの交換連鎖反応部位を２個有するトリチオカーボネート化合物など挙げられ、交換連鎖反応部位を１個のみ有するトリチオカーボネート化合物が好ましく、２－［（ドデシルスルファニルチオカルボニル）スルファニル］プロパン酸がより好ましい。 The trithiocarbonate compound is not particularly limited, and examples thereof include 2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propanoic acid, 4-{[(2-carboxyethyl)sulfanylthiocarbonyl]sulfanyl}propanoic acid, 4-cyano. A trithiocarbonate compound having only one exchange chain reaction site such as -4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid and 4-[(2-carboxyethylsulfanylthiocarbonyl)sulfanyl]-4-cyanopentanoic acid , S,S-dibenzyltrithiocarbonate, bis{4-[ethyl-(2-hydroxyethyl)carbamoyl]benzyl}trithiocarbonate, etc., such as trithiocarbonate compounds having two exchange chain reaction sites. A trithiocarbonate compound having only one chain reaction site is preferable, and 2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propanoic acid is more preferable.
　トリチオカーボネート化合物を用いて製造される架橋性ブロック共重合体において、トリチオカーボネート化合物の化学構造に起因して、架橋性ブロック共重合体中におけるトリチオカーボネート化合物残基の導入位置が異なる。トリチオカーボネート化合物が一個の交換連鎖反応部位のみを有している場合、トリチオカーボネート化合物残基は、架橋性ブロック共重合体を構成している重合体ブロックの末端に導入される。一方、トリチオカーボネート化合物が２個の交換連鎖反応部位を有している場合、トリチオカーボネート化合物残基は、架橋性ブロック共重合体を構成している重合体ブロックの内部に導入される。そして、交換連鎖反応部位を１個のみ有するトリチオカーボネート化合物を用いて可逆的連鎖移動重合（ＲＡＦＴ）によって製造された架橋性ブロック共重合体は、熱や光によってトリチオカーボネート化合物残基が分解しても、架橋性ブロック共重合体構造自体は分解されないことから、熱安定性及び紫外線架橋反応性に更に優れている。 In a crosslinkable block copolymer produced using a trithiocarbonate compound, the introduction position of the trithiocarbonate compound residue in the crosslinkable block copolymer differs due to the chemical structure of the trithiocarbonate compound. When the trithiocarbonate compound has only one exchange chain reaction site, the trithiocarbonate compound residue is introduced at the end of the polymer block constituting the crosslinkable block copolymer. On the other hand, when the trithiocarbonate compound has two exchange chain reaction sites, the trithiocarbonate compound residue is introduced inside the polymer block constituting the crosslinkable block copolymer. A crosslinkable block copolymer produced by reversible chain transfer polymerization (RAFT) using a trithiocarbonate compound having only one exchange chain reaction site decomposes the trithiocarbonate compound residue by heat or light. However, since the crosslinkable block copolymer structure itself is not decomposed, it is more excellent in thermal stability and UV crosslinking reactivity.
　架橋性ブロック共重合体は、上述の通り、ジチオエステル化合物による可逆的連鎖移動重合（ＲＡＦＴ）により製造されることが好ましい。可逆的連鎖移動重合（ＲＡＦＴ）の重合形態としては、例えば、塊状重合、溶液重合、懸濁重合、乳化重合などが挙げられ、溶液重合が好ましい。なお、架橋性ブロック共重合体を溶液重合によって製造する場合、架橋性ブロック共重合体をホットメルト粘着剤とするためには、系内の溶剤を脱処理する必要がある。 As described above, the crosslinkable block copolymer is preferably produced by reversible chain transfer polymerization (RAFT) with a dithioester compound. Examples of the reversible chain transfer polymerization (RAFT) polymerization mode include bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization, and solution polymerization is preferable. When the crosslinkable block copolymer is produced by solution polymerization, it is necessary to remove the solvent in the system in order to use the crosslinkable block copolymer as a hot melt adhesive.
　架橋性ブロック共重合体を製造するには多段階重合が行われる。例えば、交換連鎖反応部位を１個のみ有するジチオエステル化合物を用いて可逆的連鎖移動重合（ＲＡＦＴ）を行う場合、先ず、重合体ブロックＡを構成するモノマーを、ジチオエステル化合物を用いて（ジチオエステル化合物の存在下にて）十分に重合させて、重合体ブロックＡ部分重合物を得る（１段階目重合）。次に、重合反応系内に重合体ブロックＢを構成するモノマーを供給して十分に重合させ、重合体ブロックＡ－重合体ブロックＢ部分重合物を得る（２段階目重合）。更に、重合反応系内に重合体ブロックＡを構成するモノマーを供給して十分に重合させて、重合体ブロックＢの両末端に重合体ブロックＡが結合してなるＡ－Ｂ－Ａ型トリブロック共重合体である架橋性ブロック共重合体を得ることができる。 Multistep polymerization is performed to produce a crosslinkable block copolymer. For example, in the case of performing reversible chain transfer polymerization (RAFT) using a dithioester compound having only one exchange chain reaction site, first, a monomer constituting the polymer block A is converted into a dithioester compound (dithioester compound). It polymerizes sufficiently (in the presence of a compound) to obtain a polymer block A partial polymer (first stage polymerization). Next, a monomer that constitutes the polymer block B is supplied into the polymerization reaction system and sufficiently polymerized to obtain a polymer block A-polymer block B partial polymer (second-stage polymerization). Further, an ABA type triblock obtained by supplying the monomer constituting the polymer block A into the polymerization reaction system and sufficiently polymerizing it to bond the polymer block A to both ends of the polymer block B. A crosslinkable block copolymer which is a copolymer can be obtained.
　又、交換連鎖反応部位を２個有するジチオエステル化合物を用いて可逆的連鎖移動重合（ＲＡＦＴ）を行う場合、重合体ブロックＡを構成するモノマーを、ジチオエステル化合物を用いて（ジチオエステル化合物の存在下にて）十分に重合させて、重合体ブロックＡ部分重合物を得る（１段階目重合）。次に、重合反応系内に重合体ブロックＢを構成するモノマーを供給し重合する（２段階目重合）ことによって、重合体ブロックＡ部分重合物の中間部に重合体ブロックＢを形成し、Ａ－Ｂ－Ａ型トリブロック共重合体である架橋性ブロック共重合体を得ることができる。 When reversible chain transfer polymerization (RAFT) is carried out using a dithioester compound having two exchange chain reaction sites, the dithioester compound is used as the monomer constituting the polymer block A. (Below) polymerize sufficiently to obtain polymer block A partial polymer (first stage polymerization). Next, a monomer constituting the polymer block B is supplied into the polymerization reaction system and polymerized (second-stage polymerization) to form a polymer block B in the intermediate part of the polymer block A partial polymer, and A A crosslinkable block copolymer which is a —BA type triblock copolymer can be obtained.
　ジチオエステル化合物を用いて製造された架橋性ブロック共重合体は、その化学構造に由来する着色や、硫黄原子に由来する独特の臭気を有する場合がある。このような着色及び臭気の低減又は除去を目的として、架橋性ブロック共重合体中のジチオエステル化合物残基の低減又は除去処理、及び、架橋性ブロック共重合体中に混入している残存ジチオエステル化合物の低減又は除去処理を行うことが好ましい。ジチオエステル化合物残基又は残存ジチオエステル化合物の低減又は除去処理方法としては、例えば、熱による処理、紫外線による処理、過剰のラジカル開始剤による処理、求核試薬や還元剤による処理、酸化剤による処理、金属触媒による処理、ジエン化合物とのヘテロＤｉｅｌｓ－Ａｌｄｅｒ反応による処理などが挙げられる。上記処理によって、ジチオエステル化合物残基又は残存ジチオエステル化合物の低減又は除去処理されたとしても架橋性ブロック共重合体の奏する作用効果に変化はない。 A crosslinkable block copolymer produced using a dithioester compound may have a coloring derived from its chemical structure or a unique odor derived from a sulfur atom. For the purpose of reducing or removing such coloring and odor, a treatment for reducing or removing a dithioester compound residue in the crosslinkable block copolymer, and a residual dithioester mixed in the crosslinkable block copolymer. It is preferable to perform a compound reduction or removal treatment. Examples of the treatment method for reducing or removing the dithioester compound residue or the residual dithioester compound include treatment with heat, treatment with ultraviolet light, treatment with excess radical initiator, treatment with nucleophile or reducing agent, treatment with oxidizing agent. , Treatment with a metal catalyst, treatment with a hetero Diels-Alder reaction with a diene compound, and the like. Even if the dithioester compound residue or the residual dithioester compound is reduced or removed by the treatment, the action and effect of the crosslinkable block copolymer does not change.
　重合体ブロックＡを生成するための原料となるモノマー中において、ベンジル（メタ）アクリレート系モノマーの含有量は、６０質量％以上が好ましく、９０質量％以上がより好ましく、９８質量％以上が特に好ましい。ベンジル（メタ）アクリレート系モノマーの含有量は、９９質量％以下が好ましい。ベンジル（メタ）アクリレート系モノマーの含有量が上記範囲内であると、架橋性ブロック共重合体の塗工性及び熱安定性が向上すると共に、架橋性ブロック共重合体の架橋後における耐剥がれ性などの粘着性が向上する。 The content of the benzyl (meth)acrylate-based monomer in the raw material monomer for producing the polymer block A is preferably 60% by mass or more, more preferably 90% by mass or more, and particularly preferably 98% by mass or more. .. The content of the benzyl (meth)acrylate-based monomer is preferably 99% by mass or less. When the content of the benzyl (meth)acrylate-based monomer is within the above range, coating property and thermal stability of the crosslinkable block copolymer are improved, and peeling resistance after crosslinking of the crosslinkable block copolymer is improved. The adhesiveness such as is improved.
　重合体ブロックＡを生成するための原料となるモノマー中において、紫外線架橋性を有するモノマーの含有量は、４０質量％以下が好ましく、１０質量％以下がより好ましく、２質量％以下が特に好ましい。重合体ブロックＡを生成するための原料となるモノマー中において、紫外線架橋性を有するモノマーの含有量は、１質量％以上が好ましい。紫外線架橋性を有するモノマーの含有量が上記範囲内であると、架橋性ブロック共重合体の架橋後における耐剥がれ性が向上する。 In the monomer as a raw material for producing the polymer block A, the content of the UV-crosslinkable monomer is preferably 40% by mass or less, more preferably 10% by mass or less, and particularly preferably 2% by mass or less. The content of the UV-crosslinkable monomer in the monomer, which is a raw material for producing the polymer block A, is preferably 1% by mass or more. When the content of the UV-crosslinkable monomer is within the above range, the peeling resistance of the crosslinkable block copolymer after crosslinking is improved.
　重合体ブロックＡを生成するための原料となるモノマー中において、紫外線架橋性を有しないモノマーの含有量は、６０質量％以上が好ましく、９０質量％以上がより好ましく、９８質量％以上が特に好ましい。重合体ブロックＡを生成するための原料となるモノマー中において、紫外線架橋性を有しないモノマーの含有量は、９９質量％以下が好ましい。紫外線架橋性を有しないモノマーの含有量が上記範囲内であると、架橋性ブロック共重合体の架橋後における耐剥がれ性が向上する。 In the monomer that is a raw material for producing the polymer block A, the content of the monomer having no ultraviolet crosslinking property is preferably 60% by mass or more, more preferably 90% by mass or more, and particularly preferably 98% by mass or more. .. The content of the monomer having no ultraviolet crosslinking property in the raw material monomer for producing the polymer block A is preferably 99% by mass or less. When the content of the monomer having no UV crosslinking property is within the above range, the peeling resistance of the crosslinkable block copolymer after crosslinking is improved.
　重合体ブロックＢを生成するための原料となるモノマー中において、カルボキシ基含有モノマーの含有量は、１～２０質量％が好ましく、２～１０質量％がより好ましく、２．５～５質量％が特に好ましい。カルボキシ基含有モノマーの含有量が１質量％以上であると、架橋性ブロック共重合体の架橋後における耐剥がれ性が向上する。カルボキシ基含有モノマーの含有量が２０質量％以下であると、架橋性ブロック共重合体の塗工性が向上する。 The content of the carboxy group-containing monomer in the raw material monomer for producing the polymer block B is preferably 1 to 20% by mass, more preferably 2 to 10% by mass, and 2.5 to 5% by mass. Particularly preferred. When the content of the carboxy group-containing monomer is 1% by mass or more, the peeling resistance of the crosslinkable block copolymer after crosslinking is improved. When the content of the carboxy group-containing monomer is 20% by mass or less, the coatability of the crosslinkable block copolymer is improved.
　上記架橋性ブロック共重合体は、必要に応じて粘着付与剤及び光酸発生剤などの添加剤を添加することによってホットメルト粘着剤として好適に用いることができる。架橋性ブロック共重合体を含むホットメルト粘着剤は、適度な溶融粘度を有していることから、優れた塗工性を有している。 The crosslinkable block copolymer can be suitably used as a hot-melt pressure-sensitive adhesive by adding additives such as a tackifier and a photo-acid generator, if necessary. The hot-melt pressure-sensitive adhesive containing the crosslinkable block copolymer has an appropriate melt viscosity and therefore has excellent coatability.
　架橋性ブロック共重合体は、被着体上に塗工された後、架橋性ブロック共重合体に架橋処理が施されることによって、重合体ブロックＡ中に含まれる架橋性を有するモノマー単位の架橋性基が架橋構造を形成し、重合体ブロックＡ中に架橋構造が導入される。架橋構造が導入されたブロック共重合体は、耐剥がれ性などの優れた粘着性を発現する。 The crosslinkable block copolymer is coated on the adherend and then subjected to a crosslinking treatment to the crosslinkable block copolymer, whereby the crosslinkable monomer units contained in the polymer block A are The crosslinkable group forms a crosslinked structure, and the crosslinked structure is introduced into the polymer block A. The block copolymer having the crosslinked structure introduced exhibits excellent tackiness such as peel resistance.
　ホットメルト粘着剤は、その物性を損なわない範囲内において、粘着付与剤、光酸発生剤（ＵＶカチオン発生剤）、紫外線重合開始剤、可塑剤、酸化防止剤、着色剤、難燃剤及び帯電防止剤などの添加剤が含まれていてもよい。 Hot-melt pressure-sensitive adhesives are tackifiers, photo-acid generators (UV cation generators), UV polymerization initiators, plasticizers, antioxidants, colorants, flame retardants and antistatic agents, as long as their physical properties are not impaired. Additives such as agents may be included.
　本発明の架橋性ブロック共重合体は、粘度が低くて塗工性に優れていると共に熱安定性に優れている。本発明の架橋性ブロック共重合体を架橋させて得られるブロック共重合体は、粘着物性、特に耐剥がれ性に優れている。 The crosslinkable block copolymer of the present invention has a low viscosity, excellent coatability, and excellent thermal stability. The block copolymer obtained by cross-linking the cross-linkable block copolymer of the present invention is excellent in adhesive property, particularly peeling resistance.
　以下に、本発明を実施例を用いてより具体的に説明するが、本発明はこれに限定されない。 Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.
（実施例１～３及び５～１７、並びに、比較例１～４）
　攪拌機、冷却管、温度計及び窒素ガス導入口を備えたセパラブルフラスコに、紫外線非架橋性モノマーとしてベンジルアクリレート、ベンジルメタクリレート、ｎ－ブチルアクリレート、イソボルニルアクリレート、フェノキシエチルアクリレート及びｔ－ブチルアクリレートと、架橋性モノマーとして４－アクリロイルオキシベンゾフェノン、４－ヒドロキシブチルアクリレートグリシジルエーテル及び４－［２－（アクリロイルオキシ）エトキシ］ベンゾフェノンと、トリチオカーボネート化合物として２－［（ドデシルスルファニルチオカルボニル）スルファニル］プロパン酸（交換連鎖反応部位が１個）及び４－シアノー４－［（ドデシルスルファニルチオカルボニル）スルファニル］ペンタン酸（交換連鎖反応部位が１個）と、溶剤として酢酸エチルとをそれぞれ表１及び２に示した配合量ずつ供給し、攪拌して反応液を作製した。 (Examples 1 to 3 and 5 to 17 and Comparative Examples 1 to 4)
In a separable flask equipped with a stirrer, a cooling tube, a thermometer and a nitrogen gas inlet, benzyl acrylate, benzyl methacrylate, n-butyl acrylate, isobornyl acrylate, phenoxyethyl acrylate and t-butyl acrylate as UV non-crosslinking monomers. And 4-acryloyloxybenzophenone, 4-hydroxybutyl acrylate glycidyl ether and 4-[2-(acryloyloxy)ethoxy]benzophenone as the crosslinking monomer, and 2-[(dodecylsulfanylthiocarbonyl)sulfanyl] as the trithiocarbonate compound. Propanoic acid (one exchange chain reaction site) and 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid (one exchange chain reaction site) and ethyl acetate as the solvent are shown in Tables 1 and 2, respectively. Each of the compounding amounts shown in 1 was supplied and stirred to prepare a reaction liquid.
　セパラブルフラスコ内を窒素ガスで置換した後、ウォーターバスを用いて反応液を６０℃に保持した。次に、セパラブルフラスコ内の反応液に重合開始剤として２，２’－アゾビス（イソブチロニトリル）を表１及び２に示した配合量供給して可逆的連鎖移動重合（ＲＡＦＴ）を開始した。反応液を６時間に亘って６０℃に保持し、重合体ブロックＡ部分重合物を得た。重合体ブロックＡ部分重合物のピークトップ分子量及び重量平均分子量を表４及び５に示した。 After purging the inside of the separable flask with nitrogen gas, the reaction solution was kept at 60° C. using a water bath. Then, 2,2′-azobis(isobutyronitrile) as a polymerization initiator was supplied to the reaction solution in the separable flask in the compounding amounts shown in Tables 1 and 2 to start reversible chain transfer polymerization (RAFT). did. The reaction liquid was kept at 60° C. for 6 hours to obtain a polymer block A partial polymer. The peak top molecular weight and the weight average molecular weight of the polymer block A partial polymer are shown in Tables 4 and 5.
　重合体ブロックＡ部分重合物を含む反応液に、紫外線非架橋性モノマーとしてｎ－ブチルアクリレート、２－エチルヘキシルアクリレート、アクリル酸及びβ－カルボキシエチルアクリレートと、溶剤として酢酸エチルとをそれぞれ表１及び２に示した配合量ずつ供給した。反応液を６時間に亘って６０℃に保持して可逆的連鎖移動重合（ＲＡＦＴ）を行い、重合体ブロックＡ－重合体ブロックＢ部分重合物を得た。重合体ブロックＡ－重合体ブロックＢ部分重合物を構成している重合体のピークトップ分子量、及び、重合体ブロックＡ－重合体ブロックＢ部分重合物の重量平均分子量を表４及び５に示した。 In a reaction liquid containing the polymer block A partial polymer, n-butyl acrylate, 2-ethylhexyl acrylate, acrylic acid and β-carboxyethyl acrylate as a UV non-crosslinking monomer, and ethyl acetate as a solvent are shown in Tables 1 and 2, respectively. The respective compounding amounts shown in were supplied. The reaction solution was kept at 60° C. for 6 hours for reversible chain transfer polymerization (RAFT) to obtain a polymer block A-polymer block B partial polymer. Tables 4 and 5 show the peak top molecular weights of the polymers constituting the polymer block A-polymer block B partial polymer and the weight average molecular weights of the polymer block A-polymer block B partial polymer. ..
　重合体ブロックＡ－重合体ブロックＢ部分重合物を含む反応液に、紫外線非架橋性モノマーとしてベンジルアクリレート、ベンジルメタクリレート、ｎ－ブチルアクリレート、イソボルニルアクリレート、フェノキシエチルアクリレート及びｔ－ブチルアクリレートと、架橋性モノマーとして４－アクリロイルオキシベンゾフェノン、４－ヒドロキシブチルアクリレートグリシジルエーテル及び４－［２－（アクリロイルオキシ）エトキシ］ベンゾフェノンと、溶剤として酢酸エチルとをそれぞれ表１及び２に示した配合量供給した。反応液を６時間に亘って６０℃に保持して可逆的連鎖移動重合（ＲＡＦＴ）を行った後、酢酸エチルを除去して架橋性ブロック共重合体を得た。架橋性ブロック共重合体は、重合体ブロックＢの両末端に重合体ブロックＡが結合してなるＡ－Ｂ－Ａ型トリブロック共重合体であった。架橋性ブロック共重合体のピークトップ分子量、重量平均分子量及び分散度を表１及び２に示した。架橋性ブロック共重合体中の重合体ブロックＡの総含有量及び重合体ブロックＢの含有量を表４及び５に示した。 In a reaction solution containing a polymer block A-polymer block B partial polymer, benzyl acrylate, benzyl methacrylate, n-butyl acrylate, isobornyl acrylate, phenoxyethyl acrylate and t-butyl acrylate as UV non-crosslinkable monomers, 4-Acryloyloxybenzophenone, 4-hydroxybutyl acrylate glycidyl ether and 4-[2-(acryloyloxy)ethoxy]benzophenone were used as crosslinking monomers, and ethyl acetate was used as a solvent in the amounts shown in Tables 1 and 2, respectively. .. The reaction solution was kept at 60° C. for 6 hours for reversible chain transfer polymerization (RAFT), and then ethyl acetate was removed to obtain a crosslinkable block copolymer. The crosslinkable block copolymer was an ABA type triblock copolymer in which the polymer block A was bound to both ends of the polymer block B. The peak top molecular weight, weight average molecular weight and dispersity of the crosslinkable block copolymer are shown in Tables 1 and 2. The total content of polymer block A and the content of polymer block B in the crosslinkable block copolymer are shown in Tables 4 and 5.
（実施例４）
　攪拌機、冷却管、温度計及び窒素ガス導入口を備えたセパラブルフラスコに、紫外線非架橋性モノマーとしてベンジルアクリレートと、架橋性モノマーとして４－アクリロイルオキシベンゾフェノンと、トリチオカーボネート化合物としてＳ，Ｓ－ジベンジルトリチオカーボネート（交換連鎖反応部位が２個）と、溶剤として酢酸エチルとをそれぞれ表１に示した配合量ずつ供給し、攪拌して反応液を作製した。 (Example 4)
In a separable flask equipped with a stirrer, a cooling tube, a thermometer and a nitrogen gas inlet, benzyl acrylate as a UV non-crosslinking monomer, 4-acryloyloxybenzophenone as a crosslinkable monomer, and S,S- as a trithiocarbonate compound. Dibenzyl trithiocarbonate (two exchange chain reaction sites) and ethyl acetate as a solvent were supplied in the respective compounding amounts shown in Table 1 and stirred to prepare a reaction solution.
　セパラブルフラスコ内を窒素ガスで置換した後、ウォーターバスを用いて反応液を６０℃に保持した。次に、セパラブルフラスコ内の反応液に重合開始剤として２，２’－アゾビス（イソブチロニトリル）を表１に示した配合量供給して可逆的連鎖移動重合（ＲＡＦＴ）を開始した。反応液を６時間に亘って６０℃に保持し、重合体ブロックＡ部分重合物を得た。重合体ブロックＡ部分重合物のピークトップ分子量及び重量平均分子量を表４に示した。 After purging the inside of the separable flask with nitrogen gas, the reaction solution was kept at 60° C. using a water bath. Next, 2,2'-azobis(isobutyronitrile) as a polymerization initiator was supplied to the reaction solution in the separable flask in the compounding amounts shown in Table 1 to initiate reversible chain transfer polymerization (RAFT). The reaction liquid was kept at 60° C. for 6 hours to obtain a polymer block A partial polymer. The peak top molecular weight and the weight average molecular weight of the polymer block A partial polymer are shown in Table 4.
　重合体ブロックＡ部分重合物を含む反応液に、紫外線非架橋性モノマーとしてｎ－ブチルアクリレート及びアクリル酸と、溶剤として酢酸エチルとをそれぞれ表１に示した配合量ずつ供給した。反応液を６時間に亘って６０℃に保持して可逆的連鎖移動重合（ＲＡＦＴ）を行い、重合体ブロックＡ部分重合物の中間部に重合体ブロックＢを形成し、酢酸エチルを除去して架橋性ブロック共重合体を得た。架橋性ブロック共重合体は、重合体ブロックＢの両末端に重合体ブロックＡが結合してなるＡ－Ｂ－Ａ型トリブロック共重合体であった。架橋性ブロック共重合体のピークトップ分子量、重量平均分子量及び分散度を表４に示した。架橋性ブロック共重合体中の重合体ブロックＡの総含有量及び重合体ブロックＢの含有量を表４に示した。 To the reaction liquid containing the polymer block A partial polymer, n-butyl acrylate and acrylic acid as ultraviolet non-crosslinkable monomers and ethyl acetate as a solvent were supplied in the respective compounding amounts shown in Table 1. The reaction solution was kept at 60° C. for 6 hours to carry out reversible chain transfer polymerization (RAFT) to form a polymer block B in the middle part of the polymer block A partial polymer and remove ethyl acetate. A crosslinkable block copolymer was obtained. The crosslinkable block copolymer was an ABA type triblock copolymer in which the polymer block A was bound to both ends of the polymer block B. Table 4 shows the peak top molecular weight, weight average molecular weight, and dispersity of the crosslinkable block copolymer. Table 4 shows the total content of the polymer block A and the content of the polymer block B in the crosslinkable block copolymer.
（比較例５、６）
　攪拌機、冷却管、温度計及び窒素ガス導入口を備えたセパラブルフラスコに、紫外線非架橋性モノマーとしてｎ－ブチルアクリレート、アクリル酸及びベンジルアクリレートと、架橋性モノマーとして４－アクリロイルオキシベンゾフェノンと、トリチオカーボネート化合物として２－［（ドデシルスルファニルチオカルボニル）スルファニル］プロパン酸と、溶剤として酢酸エチルとをそれぞれ表３に示した配合量ずつ供給し、攪拌して反応液を作製した。 (Comparative Examples 5 and 6)
In a separable flask equipped with a stirrer, a cooling tube, a thermometer and a nitrogen gas inlet, n-butyl acrylate, acrylic acid and benzyl acrylate as a UV non-crosslinking monomer, 4-acryloyloxybenzophenone as a crosslinkable monomer, and tri- 2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propanoic acid as a thiocarbonate compound and ethyl acetate as a solvent were supplied in the respective compounding amounts shown in Table 3, and stirred to prepare a reaction liquid.
　セパラブルフラスコ内を窒素ガスで置換した後、ウォーターバスを用いて反応液を６０℃に保持した。次に、セパラブルフラスコ内の反応液に重合開始剤として２，２’－アゾビス（イソブチロニトリル）を表３に示した配合量供給して可逆的連鎖移動重合（ＲＡＦＴ）を開始した。反応液を６時間に亘って６０℃に保持して可逆的連鎖移動重合（ＲＡＦＴ）を行った後、酢酸エチルを除去して架橋性ランダム共重合体を得た。架橋性ランダム共重合体のピークトップ分子量、重量平均分子量及び分散度を表３に示した。 After purging the inside of the separable flask with nitrogen gas, the reaction solution was kept at 60° C. using a water bath. Next, reversible chain transfer polymerization (RAFT) was started by supplying 2,2'-azobis(isobutyronitrile) as a polymerization initiator in the reaction liquid in the separable flask in the compounding amounts shown in Table 3. The reaction solution was kept at 60° C. for 6 hours for reversible chain transfer polymerization (RAFT), and then ethyl acetate was removed to obtain a crosslinkable random copolymer. Table 3 shows the peak top molecular weight, weight average molecular weight and dispersity of the crosslinkable random copolymer.
（ホットメルト粘着剤の作製）
　実施例１、２、４～８及び１０～１７、比較例１～４の架橋性ブロック共重合体並びに比較例５、６の架橋性ランダム共重合体を何ら処理することなくホットメルト粘着剤として用いた。 (Preparation of hot melt adhesive)
The crosslinkable block copolymers of Examples 1, 2, 4 to 8 and 10 to 17 and Comparative Examples 1 to 4 and the crosslinkable random copolymers of Comparative Examples 5 and 6 were used as hot melt adhesives without any treatment. Using.
　実施例９の架橋性ブロック共重合体１００質量部に、光酸発生剤としてトリアリールスルホニウム塩系光酸発生剤（サンアプロ社製　商品名「ＣＰＩ－２００Ｋ」）２質量部を添加して１３０℃にて均一に混合してホットメルト粘着剤を得た。 To 100 parts by mass of the crosslinkable block copolymer of Example 9, 2 parts by mass of a triarylsulfonium salt-based photoacid generator (trade name "CPI-200K" manufactured by San-Apro Co.) as a photoacid generator was added, and the temperature was adjusted to 130°C. To obtain a hot-melt pressure-sensitive adhesive.
　実施例３の架橋性ブロック共重合体１００質量部に粘着付与剤としてロジンエステル系タッキファイヤー（Ｅａｓｔｍａｎ　Ｃｈｅｍｉｃａｌ社製　商品名「Ｆｏｒａｌ　８５－Ｅ」）１０質量部を添加して１３０℃にて均一に混合してホットメルト粘着剤を得た。 To 100 parts by mass of the crosslinkable block copolymer of Example 3, 10 parts by mass of a rosin ester-based tackifier (Product name "Foral 85-E" manufactured by Eastman Chemical Co., Ltd.) as a tackifier was added, and the mixture was uniformly added at 130°C. A hot melt adhesive was obtained by mixing.
　実施例及び比較例で得られた架橋性ブロック共重合体及び架橋性ランダム共重合体について、塗工性、熱安定性、紫外線硬化性及び粘着性を下記の要領で測定した。 With respect to the crosslinkable block copolymers and crosslinkable random copolymers obtained in Examples and Comparative Examples, coating properties, thermal stability, UV curability and tackiness were measured in the following manner.
　実施例及び比較例で得られた架橋性ブロック共重合体について、重合体ブロックＢを構成している重合体のガラス転移温度を表４及び５に記載した。 Regarding the crosslinkable block copolymers obtained in Examples and Comparative Examples, the glass transition temperatures of the polymers constituting the polymer block B are shown in Tables 4 and 5.
（塗工性）
　下記に示した測定装置を用意した。ホットメルト粘着剤１３ｇ採取し、Ｔｈｅｒｍｏｓｅｌ内に装着するアルミ筒に投入した。温度を１３０℃に設定してホットメルト粘着剤を溶融した。スピンドル４－２９を用いて３０分間に亘って溶融粘度の測定を行った。３０分間の測定後の数値を読み取り、１３０℃における溶融粘度とした。
　測定器：ＤＶ－Ｅ　Ｖｉｓｃｏｍｅｔｅｒ（Ｂｒｏｏｋｆｉｅｌｄ社製）
　　　　　Ｔｈｅｒｍｏｓｅｌ（Ｂｒｏｏｋｆｉｅｌｄ社製） (Coatability)
The measuring device shown below was prepared. 13 g of the hot melt adhesive was collected and put into an aluminum cylinder mounted in Thermosel. The temperature was set to 130° C. to melt the hot melt adhesive. Melt viscosity measurements were taken over 30 minutes using spindle 4-29. The numerical value after the measurement for 30 minutes was read to obtain the melt viscosity at 130°C.
Measuring device: DV-E Viscometer (manufactured by Brookfield)
Thermosel (manufactured by Brookfield)
　得られた１３０℃における溶融粘度に基づいて下記基準にて評価した。
　　Ａ：溶融粘度が７０Ｐａ・ｓ未満であった。
　　Ｂ：溶融粘度が７０Ｐａ・ｓ以上で且つ１５０Ｐａ・ｓ未満であった。
　　Ｃ：溶融粘度が１５０Ｐａ・ｓ以上であった。 The following criteria were evaluated based on the obtained melt viscosity at 130°C.
A: Melt viscosity was less than 70 Pa·s.
B: Melt viscosity was 70 Pa·s or more and less than 150 Pa·s.
C: Melt viscosity was 150 Pa·s or more.
（熱安定性）
　塗工性の測定時と同様の要領でホットメルト粘着剤の１３０℃における溶融粘度（初期溶融粘度）を測定した。 (Thermal stability)
The melt viscosity (initial melt viscosity) of the hot-melt pressure-sensitive adhesive at 130° C. was measured in the same manner as when measuring the coatability.
　次に、同様の測定装置を用いて、ホットメルト粘着剤１３ｇ採取し、Ｔｈｅｒｍｏｓｅｌ内に装着するアルミ筒に投入した。温度を１３０℃に設定してホットメルト粘着剤を溶融し、この状態を１週間保持した。１週間経過後に上記と同様の要領でホットメルト粘着剤の１３０℃における溶融粘度（１週間経過後溶融粘度）を測定した。溶融粘度の変化率を下記式に基づいて算出した。
　溶融粘度の変化率＝１週間経過後溶融粘度／初期溶融粘度
　　Ａ・・・溶融粘度の変化率が２未満であった。
　　Ｂ・・・溶融粘度の変化率が２以上であった。
　　Ｃ・・・１週間経過後のホットメルト粘着剤がゲル化又は高粘度化していたため、測
　　　　　　定できなかった。 Next, using the same measuring device, 13 g of the hot melt adhesive was sampled and put into an aluminum cylinder mounted in Thermosel. The temperature was set to 130° C. to melt the hot melt adhesive, and this state was maintained for 1 week. After 1 week, the melt viscosity at 130° C. (melt viscosity after 1 week) of the hot melt adhesive was measured in the same manner as above. The change rate of melt viscosity was calculated based on the following formula.
Melt viscosity change rate = Melt viscosity after 1 week/initial melt viscosity A... The melt viscosity change rate was less than 2.
B: The rate of change in melt viscosity was 2 or more.
C... It could not be measured because the hot melt adhesive after 1 week had gelled or had a high viscosity.
（紫外線硬化性）
　ホットメルト粘着剤を離型処理されたポリエチレンテレフタレート（ＰＥＴ）フィルム上に厚みが２０μｍとなるように塗工した。次に、紫外線照射装置（ヘレウス（旧フュージョンＵＶシステムズ）社製　商品名「Ｌｉｇｈｔ　Ｈａｍｍｅｒ６」（Ｈバルブ使用））を用いて、ＵＶ－Ｃ照射強度：約４８ｍＷ／ｃｍ2、ＵＶ－Ｃ積算光量：６０ｍＪ／ｃｍ2の条件下にてホットメルト粘着剤に紫外線（ＵＶ－Ｃ）を照射して、ホットメルト粘着剤を硬化させた。 (UV curable)
The hot melt adhesive was applied onto a polyethylene terephthalate (PET) film that had been subjected to a mold release treatment so that the thickness would be 20 μm. Next, UV-C irradiation intensity: about 48 mW/cm 2 , UV-C integrated light amount: using an ultraviolet irradiation device (Hereus (former Fusion UV Systems), trade name “Light Hammer 6” (H bulb used)) The hot melt adhesive was irradiated with ultraviolet rays (UV-C) under the condition of 60 mJ/cm 2 to cure the hot melt adhesive.
　硬化されたホットメルト粘着剤をポリエチレンテレフタレートフィルムより剥離して、ホットメルト接着剤０．２ｇをガラス瓶に供給した。テトラヒドロフラン３０ｇをガラス瓶に供給し、２５℃にて２４時間放置し、ホットメルト粘着剤を膨潤させた。 The cured hot melt adhesive was peeled off from the polyethylene terephthalate film, and 0.2 g of the hot melt adhesive was supplied to the glass bottle. 30 g of tetrahydrofuran was supplied to a glass bottle and left at 25° C. for 24 hours to swell the hot melt adhesive.
　膨潤させたホットメルト粘着剤を２００メッシュの金網でろ過し、８０℃に昇温した恒温槽にてホットメルト粘着剤を金網ごと乾燥させた。乾燥後のホットメルト粘着剤の質量Ｙｇを測定し、下記の要領に従ってゲル分率を算出した。
ゲル分率（％）＝１００×Ｙ／０．２ The swollen hot-melt adhesive was filtered through a 200-mesh wire net, and the hot-melt adhesive was dried together with the wire net in a thermostat heated to 80°C. The mass Yg of the dried hot melt adhesive was measured, and the gel fraction was calculated according to the following procedure.
Gel fraction (%)=100×Y/0.2
　ゲル分率が高い程、ホットメルト粘着剤の紫外線硬化性は良好であると判断できる。実施例及び比較例において、６０ｍＪ／ｃｍ2照射時に６５％以上であれば、紫外線硬化性は良好であると判断できる。 It can be judged that the higher the gel fraction is, the better the UV curability of the hot melt adhesive is. In Examples and Comparative Examples, it can be judged that the ultraviolet curability is good when the irradiation is 60 mJ/cm 2 and 65% or more.
（耐剥がれ性：定荷重保持力　対ＳＵＳ）
　ホットメルト粘着剤をポリエチレンテレフタレート（ＰＥＴ）フィルム上に厚み２０μｍとなるように塗工した。次に、紫外線照射装置（ヘレウス（旧フュージョンＵＶシステムズ）社製　商品名「Ｌｉｇｈｔ　Ｈａｍｍｅｒ６」（Ｈバルブ使用））を用いて、ＵＶ－Ｃ照射強度：約４８ｍＷ／ｃｍ2、ＵＶ－Ｃ積算光量：６０ｍＪ／ｃｍ2にてホットメルト粘着剤に紫外線（ＵＶ－Ｃ）を照射して、ホットメルト粘着剤を硬化させた。ポリエチレンテレフタレートフィルム上に厚みが２０μｍの粘着剤層が積層一体化されてなる試験片を作製した。 (Peeling resistance: Constant load holding force vs. SUS)
The hot melt adhesive was applied onto a polyethylene terephthalate (PET) film so as to have a thickness of 20 μm. Next, UV-C irradiation intensity: about 48 mW/cm 2 , UV-C integrated light amount: using an ultraviolet irradiation device (Hereus (former Fusion UV Systems), trade name “Light Hammer 6” (H bulb used)) The hot melt adhesive was irradiated with ultraviolet rays (UV-C) at 60 mJ/cm 2 to cure the hot melt adhesive. A 20 μm-thick adhesive layer was laminated and integrated on a polyethylene terephthalate film to prepare a test piece.
　試験フィルムを幅１５ｍｍ、長さ１５０ｍｍに切断して試験片を作製した。一方、ＳＵＳ板を用意し、このＳＵＳ板の表面を＃２４０の耐水紙やすりで研磨した後にヘキサンとアセトンの混合溶剤を用いて払拭して脱脂した。 A test film was prepared by cutting the test film into a width of 15 mm and a length of 150 mm. On the other hand, a SUS plate was prepared, the surface of the SUS plate was polished with a #240 water resistant sandpaper, and then wiped with a mixed solvent of hexane and acetone to degrease.
　ＳＵＳ板の表面に試験片を粘着剤層によって試験片の端部より７５ｍｍの長さを貼合した後、試験片上に２ｋｇハンドローラーを往復させた。３０分の養生時間を置いた後、試験片貼合面が下向きとなるように設置した。ＳＵＳ板に貼着させていない試験片の端部に１５０ｇの分銅を吊るし、ＳＵＳ表面に対して試験片が９０度の角度で剥離されるように荷重を掛けた状態で測定を開始した。貼合した７５ｍｍが全面的に剥離して試験片が落下した時点、又は、測定開始から１時間を経過した時点で測定を終了した。 After sticking the test piece on the surface of the SUS plate with a pressure-sensitive adhesive layer to a length of 75 mm from the end of the test piece, a 2 kg hand roller was reciprocated on the test piece. After allowing a curing time of 30 minutes, the test piece bonding surface was installed so as to face downward. The weight of 150 g was hung on the end portion of the test piece not attached to the SUS plate, and the measurement was started in a state where the load was applied so that the test piece was peeled off at an angle of 90 degrees with respect to the SUS surface. The measurement was terminated when the bonded 75 mm was entirely peeled off and the test piece dropped, or when 1 hour passed from the start of the measurement.
　測定開始から１時間を経過した時点において、試験片がＳＵＳ板から剥離した距離（剥離距離）を測定した。１時間以内に試験片がＳＵＳ板から落下した場合、試験開始から試験片が落下するのに要した時間に基づいて、試験開始から１時間経過した時点における剥離距離を比例計算した。剥離距離が短い程、耐剥がれ性に優れている。 At a time point 1 hour after the start of measurement, the distance (peeling distance) at which the test piece peeled from the SUS plate was measured. When the test piece fell from the SUS plate within 1 hour, the peeling distance at the time when 1 hour passed from the start of the test was proportionally calculated based on the time required for the test piece to fall from the start of the test. The shorter the peeling distance, the better the peeling resistance.
（耐剥がれ性：定荷重保持力　対ＰＥＴ）
　アモルファスポリエチレンテレフタレート（Ａ－ＰＥＴ）板を用意し、Ａ－ＰＥＴ板の表面をヘキサンとアセトンの混合溶剤を用いて払拭して脱脂した。このＡ－ＰＥＴ板をＳＵＳ板の代わりに用いたこと、分銅の質量を１００ｇとしたこと以外は、上述と同様の要領で剥離距離を測定した。 (Peel resistance: Constant load holding force vs. PET)
An amorphous polyethylene terephthalate (A-PET) plate was prepared, and the surface of the A-PET plate was wiped with a mixed solvent of hexane and acetone for degreasing. The peel distance was measured in the same manner as described above except that this A-PET plate was used instead of the SUS plate, and the mass of the weight was 100 g.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000007
　本発明によれば、塗工性及び熱安定性に優れ、且つ粘着物性、特に耐剥がれ性に優れた架橋性ブロック共重合体及びこれを用いたホットメルト粘着剤を提供することができる。
　（関連出願の相互参照）
　本出願は、２０１９年１月１６日に出願された日本国特許出願第２０１９－５２５３号に基づく優先権を主張し、この出願の開示はこれらの全体を参照することにより本明細書に組み込まれる。 According to the present invention, it is possible to provide a crosslinkable block copolymer having excellent coatability and thermal stability, and having excellent adhesive physical properties, particularly peel resistance, and a hot-melt adhesive using the same.
(Cross-reference of related applications)
This application claims priority based on Japanese Patent Application No. 2019-5253 filed on Jan. 16, 2019, the disclosure of which is incorporated herein by reference in its entirety. ..

Claims (6)

  1. 　重合体ブロックＢと、
    　上記重合体ブロックＢの両末端のそれぞれに結合し且つベンジル（メタ）アクリレート系モノマー単位及び紫外線架橋性を有するモノマー単位を含む重合体ブロックＡとを含むことを特徴とする架橋性ブロック共重合体。     Polymer block B,
    A crosslinkable block copolymer comprising a polymer block A which is bonded to each of both ends of the polymer block B and includes a benzyl (meth)acrylate-based monomer unit and a UV-crosslinkable monomer unit. ..
  2. 　重合体ブロックＢは、カルボキシ基含有モノマー単位を含有していると共に、重合体ブロックＢを構成している重合体のガラス転移温度が０℃以下であることを特徴とする請求項１に記載の架橋性ブロック共重合体。 The polymer block B contains a carboxy group-containing monomer unit, and the glass transition temperature of the polymer constituting the polymer block B is 0° C. or lower. Crosslinkable block copolymer.
  3. 　分子中にジチオエステル化合物残基を含むことを特徴とする請求項１又は請求項２に記載の架橋性ブロック共重合体。 The crosslinkable block copolymer according to claim 1 or 2, wherein the molecule contains a dithioester compound residue.
  4. 　請求項１～３の何れか１項に記載の架橋性ブロック共重合体を含むことを特徴とするホットメルト粘着剤。 A hot melt pressure-sensitive adhesive comprising the crosslinkable block copolymer according to any one of claims 1 to 3.
  5. 　ベンジル（メタ）アクリレート系モノマー及び紫外線架橋性を有するモノマーを含むモノマーを１個の交換連鎖反応部位を有するジチオエステル化合物の存在下にてリビング重合を行なって重合体ブロックＡ部分重合物を製造する第１工程と、
    　上記第１工程の反応系内に、エチレン性不飽和結合を有するモノマーを含むモノマーを添加してリビング重合を行なって、上記重合体ブロックＡ部分重合物に結合した重合体ブロックＢを生成して重合体ブロックＡ－重合体ブロックＢ部分重合物を製造する第２工程と、
    　上記第２工程の反応系内に、ベンジル（メタ）アクリレート系モノマー及び紫外線架橋性を有するモノマーを含むモノマーを添加してリビング重合を行なって、上記重合体ブロックＡ－重合体ブロックＢ部分重合物に結合した重合体ブロックＡを生成して架橋性ブロック共重合体を製造する第３工程とを含むことを特徴とする架橋性ブロック共重合体の製造方法。     Living block polymerization of a monomer containing a benzyl (meth)acrylate-based monomer and a monomer having an ultraviolet crosslinking property in the presence of a dithioester compound having one exchange chain reaction site to produce a polymer block A partial polymer. The first step,
    A monomer containing a monomer having an ethylenically unsaturated bond is added to the reaction system in the first step to carry out living polymerization to produce a polymer block B bonded to the polymer block A partial polymer. A second step of producing a polymer block A-polymer block B partial polymer,
    A living polymerisation is carried out by adding a monomer containing a benzyl (meth)acrylate-based monomer and a UV-crosslinkable monomer into the reaction system of the second step, to obtain the polymer block A-polymer block B partial polymer. And a third step of producing a crosslinkable block copolymer by producing a polymer block A bonded to the crosslinkable block copolymer.
  6. 　ベンジル（メタ）アクリレート系モノマー及び紫外線架橋性を有するモノマーを含むモノマーを２個の交換連鎖反応部位を有するジチオエステル化合物の存在下にてリビング重合を行なって重合体ブロックＡ部分重合物を製造する第１工程と、
    　上記第１工程の反応系内に、エチレン性不飽和結合を有するモノマーを含むモノマーを添加してリビング重合を行なって重合体ブロックＢを生成すると共に、上記重合体ブロックＢの両末端に上記重合体ブロックＡ部分重合物を結合させて架橋性ブロック共重合体を製造する第２工程とを含むことを特徴とする架橋性ブロック共重合体の製造方法。     Living block polymerization of a monomer containing a benzyl (meth)acrylate-based monomer and a monomer having an ultraviolet-crosslinking property in the presence of a dithioester compound having two exchange chain reaction sites to produce a polymer block A partial polymer. The first step,
    A monomer containing a monomer having an ethylenically unsaturated bond is added to the reaction system of the first step to carry out living polymerization to produce a polymer block B, and at the same time, both ends of the polymer block B have the above-mentioned heavy chain. And a second step of producing a crosslinkable block copolymer by combining a partial polymer of the united block A, the method for producing a crosslinkable block copolymer.
PCT/JP2020/001387 2019-01-16 2020-01-16 Crosslinkable block copolymer, production method therefor, and hot-melt adhesive WO2020149386A1 (en)

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JP2008088368A (en) * 2006-10-04 2008-04-17 Canon Inc Process for producing composition containing polymer compound, composition and liquid imparting method
JP2011201973A (en) * 2010-03-24 2011-10-13 Seiko Epson Corp Photopolymerizable polymer micelle, method of producing the same, and ink composition containing photopolymerizable polymer micelle
JP2012533652A (en) * 2009-07-15 2012-12-27 イー・アイ・デュポン・ドウ・ヌムール・アンド・カンパニー Aqueous inkjet inks containing cross-linked pigment dispersions based on diblock polymer dispersants
WO2015163321A1 (en) * 2014-04-21 2015-10-29 日立化成株式会社 Block polymer
JP2017206700A (en) * 2011-03-24 2017-11-24 スリーエム イノベイティブ プロパティズ カンパニー Flame retarding adhesives
JP2018535283A (en) * 2015-12-10 2018-11-29 エルジー・ケム・リミテッド Adhesive composition

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* Cited by examiner, † Cited by third party
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JP2008088368A (en) * 2006-10-04 2008-04-17 Canon Inc Process for producing composition containing polymer compound, composition and liquid imparting method
JP2012533652A (en) * 2009-07-15 2012-12-27 イー・アイ・デュポン・ドウ・ヌムール・アンド・カンパニー Aqueous inkjet inks containing cross-linked pigment dispersions based on diblock polymer dispersants
JP2011201973A (en) * 2010-03-24 2011-10-13 Seiko Epson Corp Photopolymerizable polymer micelle, method of producing the same, and ink composition containing photopolymerizable polymer micelle
JP2017206700A (en) * 2011-03-24 2017-11-24 スリーエム イノベイティブ プロパティズ カンパニー Flame retarding adhesives
WO2015163321A1 (en) * 2014-04-21 2015-10-29 日立化成株式会社 Block polymer
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