WO2015060210A1 - Adhesive agent composition and removable adhesive double-sided tape produced using same - Google Patents
Adhesive agent composition and removable adhesive double-sided tape produced using same Download PDFInfo
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- WO2015060210A1 WO2015060210A1 PCT/JP2014/077675 JP2014077675W WO2015060210A1 WO 2015060210 A1 WO2015060210 A1 WO 2015060210A1 JP 2014077675 W JP2014077675 W JP 2014077675W WO 2015060210 A1 WO2015060210 A1 WO 2015060210A1
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- sensitive adhesive
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- acrylic acid
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Classifications
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
- C09J133/04—Homopolymers or copolymers of esters
- C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
- C09J133/062—Copolymers with monomers not covered by C09J133/06
- C09J133/066—Copolymers with monomers not covered by C09J133/06 containing -OH groups
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/67—Unsaturated compounds having active hydrogen
- C08G18/671—Unsaturated compounds having only one group containing active hydrogen
- C08G18/672—Esters of acrylic or alkyl acrylic acid having only one group containing active hydrogen
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J7/00—Adhesives in the form of films or foils
- C09J7/20—Adhesives in the form of films or foils characterised by their carriers
- C09J7/21—Paper; Textile fabrics
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J7/00—Adhesives in the form of films or foils
- C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
- C09J7/38—Pressure-sensitive adhesives [PSA]
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J2301/00—Additional features of adhesives in the form of films or foils
- C09J2301/10—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet
- C09J2301/12—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers
- C09J2301/124—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers the adhesive layer being present on both sides of the carrier, e.g. double-sided adhesive tape
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J2400/00—Presence of inorganic and organic materials
- C09J2400/20—Presence of organic materials
- C09J2400/26—Presence of textile or fabric
- C09J2400/263—Presence of textile or fabric in the substrate
-
- 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
- C09J2431/00—Presence of polyvinyl acetate
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J2433/00—Presence of (meth)acrylic polymer
Definitions
- the present invention relates to a pressure-sensitive adhesive composition and a re-peelable double-sided adhesive tape using the same.
- Double-sided tape is used in various fields, from daily necessities to fixing industrial parts. As market needs, there is a great demand for those having excellent adhesive strength, little change in adhesive strength with time, and good removability. Normally, strong adhesiveness is imparted by introducing a large amount of acid into the adhesive, but when such a strong adhesive adhesive is adhered to a polar adherend such as metal, the adhesive strength increases over time. However, there is a problem that adhesive residue is easily left during peeling.
- non-woven fabric is generally used for the core material of the double-sided tape.
- a nonwoven fabric core material with high mechanical strength is used for double-sided tapes that require strong adhesiveness.
- the nonwoven fabric core material with high mechanical strength usually has a large basis weight and poor penetration of the pressure-sensitive adhesive, when peeled, the breakage occurs between the core layers where the pressure-sensitive adhesive has not sufficiently penetrated. As a result, there was a problem that good removability could not be obtained.
- Patent Document 1 proposes a releasable pressure-sensitive adhesive tape in which a pressure-sensitive adhesive layer mainly comprising a (meth) acrylic resin composition containing substantially no carboxyl group is provided on a base film.
- Patent Document 2 discloses an acrylic resin and a crosslinking agent obtained by polymerizing a (meth) acrylic acid alkyl ester monomer and a monomer having a functional group other than an acidic group in the presence of a functional group-containing polymerization initiator. Containing pressure-sensitive adhesive compositions have been proposed.
- the present invention has been made to solve the above-described problems, and has excellent adhesive strength and holding power, good penetration into a nonwoven fabric core material, particularly a high basis weight nonwoven fabric core material, and release. It is an object of the present invention to provide a pressure-sensitive adhesive composition that can be suitably used for a re-peelable double-sided adhesive tape that can be peeled without contaminating the adherend.
- the present inventors have obtained a copolymer obtained by copolymerizing a specific monomer component, having a hydroxyl group and substantially having a carboxyl group.
- the pressure-sensitive adhesive composition comprising a copolymer having a weight average molecular weight of 150,000 to 500,000 and an isocyanate cross-linking agent having two or more isocyanate groups can solve the above-mentioned problems. It came to complete. That is, the present invention is shown by the following [1] to [8].
- a pressure-sensitive adhesive composition comprising a (meth) acrylic acid alkyl ester copolymer (A) and an isocyanate crosslinking agent (B) having two or more isocyanate groups, A pressure-sensitive adhesive composition, wherein the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) has an acid value of less than 1 mgKOH / g and a weight average molecular weight of 150,000 to 500,000.
- the (meth) acrylate monomer (a2) having a hydroxyl group is at least one selected from the group consisting of 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate.
- the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) is 40% by mass to 99.7% by mass of (meth) acrylic acid alkyl ester monomer (a1), 0.1% by mass to (Meth) acrylate monomer (a2) having 30% by mass of hydroxyl group, 0.1% by mass to 50% by mass of vinyl acetate (a3) and 0.1% by mass to 30% by mass of maleate ester monomer (a4)
- the pressure-sensitive adhesive composition according to [1] or [2] which is obtained by copolymerization.
- the isocyanate cross-linking agent (B) is contained in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A).
- the adhesive composition as described in any one of [3].
- a pressure-sensitive adhesive composition for a releasable pressure-sensitive adhesive tape comprising the pressure-sensitive adhesive composition according to any one of [1] to [4].
- a releasable pressure-sensitive adhesive tape wherein a pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition for a releasable pressure-sensitive adhesive tape according to [5] is formed on at least one surface of a nonwoven fabric core material.
- a releasable pressure-sensitive adhesive double-sided tape wherein a pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition for re-peelable pressure-sensitive adhesive tape according to [5] is formed on both surfaces of a nonwoven fabric core material.
- the adhesive strength and holding power are excellent, the penetration into a nonwoven fabric core material, in particular, a high basis weight nonwoven fabric core material is good, and it is possible to peel the substrate without contaminating the adherend.
- An adhesive composition that can be suitably used for a peelable double-sided adhesive tape can be provided.
- the present invention is described in detail below.
- the pressure-sensitive adhesive composition of the present invention comprises a vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) having an acid value of less than 1 mgKOH / g and an isocyanate crosslinking agent (B) as main components.
- (meth) acryl means methacryl or acryl.
- the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) comprises a (meth) acrylic acid alkyl ester monomer (a1), a (meth) acrylate monomer (a2) having a hydroxyl group, vinyl acetate (a3), And a maleic ester monomer (a4).
- (meth) acrylate means acrylate or methacrylate.
- the (meth) acrylic acid alkyl ester monomer (a1) is an alkyl ester of (meth) acrylic acid that does not contain a hydroxyl group, and the alkyl group usually has 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms. More preferably 1-8, most preferably 4-8.
- (meth) acrylic acid alkyl ester monomer (a1) examples include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meta ) Acrylate, n-propyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) ) Acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate and the like. These monomers can be used alone or in combination of two or more.
- n-butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate are preferred in terms of copolymerizability, adhesive properties, ease of handling, and availability of raw materials.
- methyl methacrylate are preferable, and n-butyl (meth) acrylate and methyl methacrylate are more preferable in view of excellent heat resistance.
- the (meth) acrylate monomer (a2) having a hydroxyl group is a monomer having a hydroxyl group and a (meth) acryloyl group, and examples thereof include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 5-hydroxypentyl.
- Hydroxyalkyl esters of acrylic acid such as (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, caprolactone-modified monomers such as caprolactone-modified 2-hydroxyethyl (meth) acrylate, diethylene glycol (meth) Oxyalkylene-modified monomers such as acrylate and polyethylene glycol (meth) acrylate, 2-acryloyloxyethyl 2-hydroxyethylphthalic acid, N-methylol (meta Primary hydroxyl group-containing monomers such as acrylamide, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate Secondary hydroxyl group-containing monomers such as 2-hydroxy-3-phenoxypropyl (meth) acrylate, and terti
- (meth) acrylate monomer (a2) having a hydroxyl group a primary hydroxyl group-containing monomer is preferable in terms of excellent reactivity with a crosslinking agent, and further, there are few impurities, and 2-hydroxyethyl (meta) ) Acrylate is more preferred.
- maleate monomer (a4) examples include dimethyl maleate, diethyl maleate, diisopropyl maleate, dibutyl maleate, di-2-ethylhexyl maleate, diallyl maleate, monomethyl maleate, monoethyl maleate, maleic acid Examples thereof include monobutyl and mono-2-ethylhexyl maleate. These monomers can be used alone or in combination of two or more.
- dimethyl maleate, diethyl maleate, dibutyl maleate, di-2-ethylhexyl maleate and diallyl maleate are preferred in terms of reactivity and pressure-sensitive adhesive properties. From the viewpoint of releasability, di-2-ethylhexyl maleate is more preferable.
- the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) comprises 40% by mass to 99.7% by mass of the monomer (a1), 0.1% by mass to 30% by mass of the monomer (a2), It is preferable that 0.1% by mass to 50% by mass of vinyl acetate (a3) and 0.1% by mass to 30% by mass of monomer (a4) are copolymerized, and 50% by mass to 90% by mass.
- the monomer (a4) is copolymerized with 50% by mass to 80% by mass of the monomer (a1), 0.3% by mass to 10% by mass of the monomer (a2), and 0% by mass. 2% to 35% by weight of vinyl acetate (a3), 0.2% It is even more preferable that the monomer (a4) is copolymerized in an amount of 10% by mass to 10% by mass, and 55% by mass to 70% by mass of the monomer (a1) and 0.4% by mass to 5% by mass of the monomer (a4). Most preferably, the monomer (a2), 10% by mass to 35% by mass vinyl acetate (a3) and 5% by mass to 10% by mass monomer (a4) are copolymerized.
- the amount of the (meth) acrylic acid alkyl ester monomer (a1) used is 99.7% by mass or less, the cohesive strength of the copolymer is improved, and better removability can be obtained.
- the amount of the (meth) acrylic acid alkyl ester monomer (a1) used is 40% by mass or more, the cohesive strength of the copolymer becomes appropriate, and the decrease in adhesive strength is small. If the usage-amount of the (meth) acrylate monomer (a2) which has a hydroxyl group is 30 mass% or less, the penetration property to a core material will become suitable, and more favorable removability can be obtained.
- the amount of the (meth) acrylate monomer (a2) having a hydroxyl group is 0.1% by mass or more, the introduction amount of the hydroxyl group becomes appropriate, and a sufficient crosslinking point is secured. Can be obtained. If the usage-amount of vinyl acetate (a3) is 50 mass% or less, the penetration property to a core material becomes appropriate, and more favorable removability can be obtained. On the other hand, if the usage-amount of vinyl acetate (a3) is 0.1 mass% or more, the cohesive force of a copolymer will improve and better removability can be obtained.
- the amount of the maleic ester monomer (a4) used is 30% by mass or less, the cohesive strength of the copolymer becomes appropriate and the decrease in adhesive strength is small.
- the amount of the maleic ester monomer (a4) used is 0.1% by mass or more, the cohesive strength of the copolymer is improved, and better removability can be obtained.
- the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) contains substantially no carboxyl group, that is, has an acid value of less than 1 mgKOH / g.
- the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) preferably contains no carboxyl group.
- the acid value of the copolymer (A) is a value measured according to JIS K0070, and is measured, for example, as follows.
- Acid value (mgKOH / g) [B ⁇ f ⁇ 5.611] / S (1)
- B is the amount (ml) of 0.1N potassium hydroxide-ethanol solution used
- f is the factor of 0.1N potassium hydroxide-ethanol solution
- S is the sample The amount collected (g).
- the weight average molecular weight of the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) needs to be 150,000 to 500,000, preferably 200,000 to 400,000. When the weight average molecular weight is less than 150,000, excellent holding power cannot be obtained. On the other hand, when the weight average molecular weight exceeds 500,000, the penetrability into the core material is lowered and good removability is obtained. Absent.
- the weight average molecular weight of the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) is determined by gel permeation chromatography (“Showex (trademark) GPC SYSTEM— 11 ”, column: Shodex (trademark) GPC KF-806L (exclusion limit molecular weight: 2 ⁇ 10 7 , separation range: 100 to 2 ⁇ 10 7 , theoretical plate number: 10,000 plates / tube, packing material: average particle Styrene-divinylbenzene copolymer having a diameter of 10 ⁇ m), sample: 0.5% by mass tetrahydrofuran solution of copolymer, developing solvent: tetrahydrofuran, column temperature: 40 ° C., flow rate: 2 mL / min It is a weight average molecular weight in terms of standard polystyrene molecular weight.
- the copolymerization reaction for obtaining the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) is not particularly limited, and a normal radical polymerization method can be applied.
- a monomer in which a polymerization initiator such as 2,2′-azobis (isobutyronitrile) or benzoyl peroxide is dissolved in the monomer (a1), the monomer (a2), the vinyl acetate (a3) and the monomer (a4).
- the solution is dropped into an organic solvent and polymerized at 60 to 100 ° C. for 2 to 10 hours to obtain an organic solvent solution of the copolymer comprising (a1) to (a4).
- the amount of the polymerization initiator used is usually 0.01 parts by weight to 1.0 parts by weight, preferably 0.05 parts by weight to 0.5 parts by weight with respect to 100 parts by weight as the total amount of (a1) to (a4). Part by mass.
- organic solvent used for polymerization examples include ester solvents such as methyl acetate, ethyl acetate, methyl acetoacetate, and ethyl acetoacetate, aromatic hydrocarbons such as toluene and xylene, n-propyl alcohol, and iso-propyl alcohol. And aliphatic alcohols such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. These organic solvents can be used alone or in combination of two or more. Among these organic solvents, ethyl acetate is preferable in terms of solubility, drying properties, environmental aspects, price, and the like.
- the pressure-sensitive adhesive composition of the present invention is obtained by mixing the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) thus obtained with the isocyanate crosslinking agent (B). Although the crosslinking reaction starts after mixing, it takes some time for crosslinking to proceed sufficiently at room temperature.
- the isocyanate crosslinking agent (B) is a compound having two or more isocyanato groups capable of reacting with a hydroxyl group in one molecule.
- Specific examples of the isocyanate crosslinking agent (B) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hydrogenated tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, Hexamethylene diisocyanate, diphenylmethane-4,4-diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, tetramethylxylylene diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, and their poly Examples include adducts of isocyanate compounds and polyol compounds such as trimethylolpropane, burettes and
- isocyanate crosslinking agents (B) 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, and hexamethylene diisocyanate are preferable in terms of reactivity, and 2,4-tolylene diene in terms of pressure-sensitive adhesive properties. More preferred are isocyanate and 2,6-tolylene diisocyanate.
- the amount of the isocyanate crosslinking agent (B) used is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A). More preferably, it is 5 to 5 parts by mass, and most preferably 1.0 to 2.5 parts by mass. If the amount of the isocyanate crosslinking agent (B) used is 0.1 parts by mass or more with respect to 100 parts by mass of the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A), the holding power becomes sufficient and better Heat resistance and removability can be obtained.
- the amount of the isocyanate crosslinking agent (B) used is 10 parts by mass or less with respect to 100 parts by mass of the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A), the flexibility of the resin is ensured, Impregnation into the core material is improved and better removability can be obtained.
- the pressure-sensitive adhesive composition of the present invention preferably contains 40% by mass to 99.9% by mass of a nonvolatile content.
- the non-volatile content is a value calculated from the following formula by weighing about 1 g of the pressure-sensitive adhesive composition on an aluminum dish having a diameter of 5 cm and then drying the residue at 110 ° C. for 5 hours and weighing the residue. It is.
- the volatile matter here is ethyl acetate or the like.
- Nonvolatile content (mass%) (mass of residual) / (initial mass) ⁇ 100
- the pressure-sensitive adhesive composition of the present invention includes an antistatic agent, other acrylic pressure-sensitive adhesives, rosin, rosin ester, hydrogenated rosin ester, aromatic modified terpene resin, phenol as long as the effects of the present invention are not impaired.
- Various additives such as tackifiers such as resins, xylene resins, styrene resins, coumarone resins, aliphatic petroleum resins, alicyclic petroleum resins, coloring agents, fillers, anti-aging agents, and UV absorbers are added. May be.
- the nonwoven fabric core material for applying the pressure-sensitive adhesive composition of the present invention to provide a pressure-sensitive adhesive layer includes wet nonwoven fabrics using fibers such as rayon, pulp, hemp, and vinylon, polyesters that are long fibers, polypropylene, polyethylene, and nylon. Examples thereof include dry nonwoven fabrics, spunbonds, needle punches, water punches, and spunlaces that mainly use synthetic resin fibers such as.
- the nonwoven fabric core material may be composed of one type of fiber, or may be composed of two or more types of fibers.
- the basis weight of the nonwoven fabric core is preferably 10 g / m 2 to 30 g / m 2 , and 12 g / m 2 to 28 g / m 2 in terms of ensuring sufficient strength and suppressing interlaminar fracture. Is more preferable, and it is most preferable that it is 14 g / m 2 to 26 g / m 2 . Further, the thickness of the nonwoven fabric core material is appropriately set in the range of 15 ⁇ m to 125 ⁇ m depending on the application.
- the pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition of the present invention
- a direct method in which the pressure-sensitive adhesive composition is directly coated on a nonwoven fabric core and dried, paper that has been subjected to mold release treatment with silicone or the like
- a release material such as a plastic film
- a pressure-sensitive adhesive layer by cross-linking by drying, and then pressurizing the nonwoven fabric core material on the pressure-sensitive adhesive layer
- Examples thereof include a transfer method in which the pressure-sensitive adhesive layer is transferred onto the nonwoven fabric core material. After forming the pressure-sensitive adhesive layer on both surfaces of the nonwoven fabric core material, an aging treatment may be performed as necessary.
- the coating method is not particularly limited as long as it is a general coating method, and examples thereof include a method using roll coating, die coating, gravure coating, comma coating, screen printing and the like.
- release material for example, various synthetic resin sheets, paper, cloth, non-woven fabric, etc., which have been subjected to release treatment can be used.
- the drying condition after coating is not particularly limited as long as the pressure-sensitive adhesive composition can be dried and cross-linked, for example, at 50 to 150 ° C. for 1 to 5 minutes.
- the aging treatment is performed in order to balance the physical properties of the adhesive, and the aging conditions are usually from room temperature (25 ° C. ⁇ 5 ° C.) to 70 ° C. for 1 day to 30 days.
- the treatment may be performed under conditions such as 1 day to 20 days at 40 ° C. or 1 day to 7 days at 40 ° C.
- the pressure-sensitive adhesive composition of the present invention can be used for a re-peelable pressure-sensitive adhesive tape, and is particularly suitable for a re-peelable pressure-sensitive adhesive double-sided tape.
- the thickness of the pressure-sensitive adhesive layer in the re-peelable pressure-sensitive adhesive tape or the re-peelable pressure-sensitive adhesive double-sided tape of the present invention is preferably 5 ⁇ m to 250 ⁇ m, more preferably 5 ⁇ m to 150 ⁇ m, and most preferably 5 ⁇ m to 100 ⁇ m.
- the thickness of the pressure-sensitive adhesive layer is 5 ⁇ m or more, the physical properties of the pressure-sensitive adhesive are stabilized, and a better adhesive force can be obtained.
- the thickness of the pressure-sensitive adhesive layer is 250 ⁇ m or less, the pressure-sensitive adhesive composition can be easily dried.
- the polymerization catalyst solution in which 0.2 parts by mass of AIBN was dissolved in 10 parts by mass of ethyl acetate was successively added for 7 hours, diluted with ethyl acetate, cooled, and then discharged from the reactor.
- the ester / (meth) acrylic acid alkyl ester copolymer solution was taken out.
- the weight average molecular weight of the vinyl ester / (meth) acrylic acid alkyl ester copolymer was 360,000.
- the nonvolatile content of the vinyl ester / (meth) acrylic acid alkyl ester copolymer solution was 51% by mass.
- the acid value of the vinyl ester / (meth) acrylic acid alkyl ester copolymer is 0 mgKOH / g.
- Examples 1 to 4 and Comparative Examples 1 to 5> Next, 45% isocyanate cross-linking agent (Coronate (registered trademark) L-45E manufactured by Nippon Polyurethane Industry Co., Ltd.) was added to the copolymer solutions of Synthesis Examples 1 to 8 in the blending amounts shown in Table 2 to form an adhesive composition. A product was prepared.
- isocyanate cross-linking agent Coronate (registered trademark) L-45E manufactured by Nippon Polyurethane Industry Co., Ltd.
- a double-sided tape was prepared according to the following method and subjected to characteristic evaluation (initial adhesive force, removability, holding force and ball tack). The results are shown in Tables 3 and 4.
- the obtained double-sided tape was affixed to a stainless steel plate so that the area was 25 mm ⁇ 25 mm, and a load of 1 kg was applied under the condition of 80 ° C., according to the holding power measurement method of JIS Z 0237, The falling time was measured, and the deviation after 24 hours was measured for those whose dropping time exceeded 24 hours.
- the example product when the appropriate amount of the isocyanate cross-linking agent was blended, the example product had excellent removability while having excellent adhesive strength. Furthermore, there was no problem with respect to the cohesive force without any deviation.
Abstract
An adhesive agent composition according to the present invention comprises a (vinyl ester)-((meth)acrylic acid alkyl ester) copolymer (A) produced by copolymerizing a (meth)acrylic acid alkyl ester monomer (a1), a (meth)acrylate monomer having a hydroxy group (a2), vinyl acetate (a3) and a maleic acid ester monomer (a4) with one another and an isocyanate cross-linking agent (B) having at least two isocyanate groups, said adhesive agent composition being characterized in that the (vinyl ester)-((meth)acrylic acid alkyl ester) copolymer (A) has an acid value of less than 1 mgKOH/g and a weight average molecular weight of 150,000 to 500,000. According to the present invention, an adhesive agent composition can be provided which can be used suitably for a removable adhesive double-sided tape that has excellent adhesion power and holding power, has a good property of being seeped into a non-woven fabric core material, particularly a non-woven fabric core material having a high weight per device area, and can be removed from an object of interest without staining the object upon the removal of the adhesive double-sided tape from the object.
Description
本発明は、粘着剤組成物及びそれを用いた再剥離型粘着両面テープに関する。
The present invention relates to a pressure-sensitive adhesive composition and a re-peelable double-sided adhesive tape using the same.
両面テープは、日用品から工業部品の固定などの様々な分野で使用されている。市場ニーズとしては、優れた粘着力を有し、粘着力の経時変化が少なく且つ良好な再剥離性を有しているものの要求が大きい。通常、粘着剤に酸を多く導入することにより強粘着性が付与されているが、そのような強粘着性粘着剤を金属などの極性被着体に粘着させた場合、粘着力が経時で増加し、剥離の際に糊残りし易いという問題があった。
両 面 Double-sided tape is used in various fields, from daily necessities to fixing industrial parts. As market needs, there is a great demand for those having excellent adhesive strength, little change in adhesive strength with time, and good removability. Normally, strong adhesiveness is imparted by introducing a large amount of acid into the adhesive, but when such a strong adhesive adhesive is adhered to a polar adherend such as metal, the adhesive strength increases over time. However, there is a problem that adhesive residue is easily left during peeling.
一方、両面テープの芯材には、不織布が一般的に使用されている。強粘着性が要求される両面テープには、機械的強度の強い不織布芯材が使用される。しかし、通常、機械的強度の強い不織布芯材は坪量が大きく、粘着剤の染み込み性が悪いので、剥離の際に、粘着剤が十分に染み込んでいない芯材層間で破壊が発生し、結果として良好な再剥離性が得られないという問題があった。
On the other hand, non-woven fabric is generally used for the core material of the double-sided tape. For double-sided tapes that require strong adhesiveness, a nonwoven fabric core material with high mechanical strength is used. However, since the nonwoven fabric core material with high mechanical strength usually has a large basis weight and poor penetration of the pressure-sensitive adhesive, when peeled, the breakage occurs between the core layers where the pressure-sensitive adhesive has not sufficiently penetrated. As a result, there was a problem that good removability could not be obtained.
例えば、特許文献１には、カルボキシル基を実質的に含有しない（メタ）アクリル系樹脂組成物を主成分とする粘着剤層を基材フィルム上に設けた再剥離性粘着テープが提案されている。また、特許文献２には、（メタ）アクリル酸アルキルエステル系モノマーと酸性基以外の官能基を有するモノマーとを官能基含有重合開始剤の存在下で重合してなるアクリル系樹脂及び架橋剤を含有する粘着剤組成物が提案されている。
For example, Patent Document 1 proposes a releasable pressure-sensitive adhesive tape in which a pressure-sensitive adhesive layer mainly comprising a (meth) acrylic resin composition containing substantially no carboxyl group is provided on a base film. . Patent Document 2 discloses an acrylic resin and a crosslinking agent obtained by polymerizing a (meth) acrylic acid alkyl ester monomer and a monomer having a functional group other than an acidic group in the presence of a functional group-containing polymerization initiator. Containing pressure-sensitive adhesive compositions have been proposed.
しかしながら、本発明者らが、特許文献１に記載の再剥離性粘着テープについて検討したところ、粘着力が不十分であることが分かった。また、特許文献２に記載の粘着剤組成物についても検討したところ、ある程度の粘着力は得られるものの、粘着剤の保持力が不十分であることが分かった。
However, when the present inventors examined the removable adhesive tape described in Patent Document 1, it was found that the adhesive strength was insufficient. Moreover, when the pressure-sensitive adhesive composition described in Patent Document 2 was also examined, it was found that although a certain level of pressure-sensitive adhesive force was obtained, the pressure-sensitive adhesive holding power was insufficient.
従って、本発明は、上記のような課題を解決するためになされたものであり、粘着力及び保持力が優れ、不織布芯材、特に高坪量の不織布芯材への染み込み性が良く、剥離の際に被着体を汚染することがなく剥離可能な再剥離型粘着両面テープに好適に用いることができる粘着剤組成物を提供することを目的とする。
Accordingly, the present invention has been made to solve the above-described problems, and has excellent adhesive strength and holding power, good penetration into a nonwoven fabric core material, particularly a high basis weight nonwoven fabric core material, and release. It is an object of the present invention to provide a pressure-sensitive adhesive composition that can be suitably used for a re-peelable double-sided adhesive tape that can be peeled without contaminating the adherend.
そこで、本発明者らは、上記課題を解決すべく鋭意検討した結果、特定のモノマー成分を共重合して得られる共重合体であって、水酸基を有し、実質的にカルボキシル基を有さず、重量平均分子量が１５万～５０万である共重合体と、２つ以上のイソシアナト基を有するイソシアネート架橋剤とを含む粘着剤組成物が、上記課題を解決し得ることを見出し、本発明を完成するに至った。
即ち、本発明は、以下の［１］～［８］で示される。
［１］（メタ）アクリル酸アルキルエステルモノマー（ａ１）、水酸基を有する（メタ）アクリレートモノマー（ａ２）、酢酸ビニル（ａ３）及びマレイン酸エステルモノマー（ａ４）を共重合させて得られるビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）と、２つ以上のイソシアナト基を有するイソシアネート架橋剤（Ｂ）とを含む粘着剤組成物であって、
前記ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）の酸価が１ｍｇＫＯＨ／ｇ未満であり且つ重量平均分子量が１５万～５０万であることを特徴とする粘着剤組成物。
［２］前記水酸基を有する（メタ）アクリレートモノマー（ａ２）が、２－ヒドロキシエチルアクリレート及び２－ヒドロキシエチルメタアクリレートからなる群から選択される少なくとも１種であることを特徴とする［１］に記載の粘着剤組成物。
［３］前記ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）が、４０質量％～９９．７質量％の（メタ）アクリル酸アルキルエステルモノマー（ａ１）、０．１質量％～３０質量％の水酸基を有する（メタ）アクリレートモノマー（ａ２）、０．１質量％～５０質量％の酢酸ビニル（ａ３）及び０．１質量％～３０質量％のマレイン酸エステルモノマー（ａ４）を共重合させて得られるものであることを特徴とする［１］又は［２］に記載の粘着剤組成物。
［４］前記ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）１００質量部に対して前記イソシアネート架橋剤（Ｂ）を０．１質量部～１０質量部含むことを特徴とする［１］～［３］の何れかに記載の粘着剤組成物。
［５］［１］～［４］の何れかに記載の粘着剤組成物からなることを特徴とする再剥離型粘着テープ用粘着剤組成物。
［６］［５］に記載の再剥離型粘着テープ用粘着剤組成物を架橋して得られる粘着剤層を不織布芯材の少なくとも一方の面に形成したことを特徴とする再剥離型粘着テープ。
［７］［５］に記載の再剥離型粘着テープ用粘着剤組成物を架橋して得られる粘着剤層を不織布芯材の両面に形成したことを特徴とする再剥離型粘着両面テープ。
［８］前記不織布芯材の坪量が、１０ｇ／ｍ2～３０ｇ／ｍ2であることを特徴とする［７］に記載の再剥離型粘着両面テープ。 Therefore, as a result of intensive studies to solve the above problems, the present inventors have obtained a copolymer obtained by copolymerizing a specific monomer component, having a hydroxyl group and substantially having a carboxyl group. The pressure-sensitive adhesive composition comprising a copolymer having a weight average molecular weight of 150,000 to 500,000 and an isocyanate cross-linking agent having two or more isocyanate groups can solve the above-mentioned problems. It came to complete.
That is, the present invention is shown by the following [1] to [8].
[1] Vinyl ester obtained by copolymerizing (meth) acrylic acid alkyl ester monomer (a1), (meth) acrylate monomer (a2) having hydroxyl group, vinyl acetate (a3) and maleic acid ester monomer (a4) A pressure-sensitive adhesive composition comprising a (meth) acrylic acid alkyl ester copolymer (A) and an isocyanate crosslinking agent (B) having two or more isocyanate groups,
A pressure-sensitive adhesive composition, wherein the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) has an acid value of less than 1 mgKOH / g and a weight average molecular weight of 150,000 to 500,000.
[2] In the above [1], the (meth) acrylate monomer (a2) having a hydroxyl group is at least one selected from the group consisting of 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate. The pressure-sensitive adhesive composition described.
[3] The vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) is 40% by mass to 99.7% by mass of (meth) acrylic acid alkyl ester monomer (a1), 0.1% by mass to (Meth) acrylate monomer (a2) having 30% by mass of hydroxyl group, 0.1% by mass to 50% by mass of vinyl acetate (a3) and 0.1% by mass to 30% by mass of maleate ester monomer (a4) The pressure-sensitive adhesive composition according to [1] or [2], which is obtained by copolymerization.
[4] The isocyanate cross-linking agent (B) is contained in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A). [1] The adhesive composition as described in any one of [3].
[5] A pressure-sensitive adhesive composition for a releasable pressure-sensitive adhesive tape, comprising the pressure-sensitive adhesive composition according to any one of [1] to [4].
[6] A releasable pressure-sensitive adhesive tape, wherein a pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition for a releasable pressure-sensitive adhesive tape according to [5] is formed on at least one surface of a nonwoven fabric core material. .
[7] A releasable pressure-sensitive adhesive double-sided tape, wherein a pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition for re-peelable pressure-sensitive adhesive tape according to [5] is formed on both surfaces of a nonwoven fabric core material.
[8] The releasable pressure-sensitive adhesive double-sided tape according to [7], wherein the nonwoven fabric core has a basis weight of 10 g / m 2 to 30 g / m 2 .
即ち、本発明は、以下の［１］～［８］で示される。
［１］（メタ）アクリル酸アルキルエステルモノマー（ａ１）、水酸基を有する（メタ）アクリレートモノマー（ａ２）、酢酸ビニル（ａ３）及びマレイン酸エステルモノマー（ａ４）を共重合させて得られるビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）と、２つ以上のイソシアナト基を有するイソシアネート架橋剤（Ｂ）とを含む粘着剤組成物であって、
前記ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）の酸価が１ｍｇＫＯＨ／ｇ未満であり且つ重量平均分子量が１５万～５０万であることを特徴とする粘着剤組成物。
［２］前記水酸基を有する（メタ）アクリレートモノマー（ａ２）が、２－ヒドロキシエチルアクリレート及び２－ヒドロキシエチルメタアクリレートからなる群から選択される少なくとも１種であることを特徴とする［１］に記載の粘着剤組成物。
［３］前記ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）が、４０質量％～９９．７質量％の（メタ）アクリル酸アルキルエステルモノマー（ａ１）、０．１質量％～３０質量％の水酸基を有する（メタ）アクリレートモノマー（ａ２）、０．１質量％～５０質量％の酢酸ビニル（ａ３）及び０．１質量％～３０質量％のマレイン酸エステルモノマー（ａ４）を共重合させて得られるものであることを特徴とする［１］又は［２］に記載の粘着剤組成物。
［４］前記ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）１００質量部に対して前記イソシアネート架橋剤（Ｂ）を０．１質量部～１０質量部含むことを特徴とする［１］～［３］の何れかに記載の粘着剤組成物。
［５］［１］～［４］の何れかに記載の粘着剤組成物からなることを特徴とする再剥離型粘着テープ用粘着剤組成物。
［６］［５］に記載の再剥離型粘着テープ用粘着剤組成物を架橋して得られる粘着剤層を不織布芯材の少なくとも一方の面に形成したことを特徴とする再剥離型粘着テープ。
［７］［５］に記載の再剥離型粘着テープ用粘着剤組成物を架橋して得られる粘着剤層を不織布芯材の両面に形成したことを特徴とする再剥離型粘着両面テープ。
［８］前記不織布芯材の坪量が、１０ｇ／ｍ2～３０ｇ／ｍ2であることを特徴とする［７］に記載の再剥離型粘着両面テープ。 Therefore, as a result of intensive studies to solve the above problems, the present inventors have obtained a copolymer obtained by copolymerizing a specific monomer component, having a hydroxyl group and substantially having a carboxyl group. The pressure-sensitive adhesive composition comprising a copolymer having a weight average molecular weight of 150,000 to 500,000 and an isocyanate cross-linking agent having two or more isocyanate groups can solve the above-mentioned problems. It came to complete.
That is, the present invention is shown by the following [1] to [8].
[1] Vinyl ester obtained by copolymerizing (meth) acrylic acid alkyl ester monomer (a1), (meth) acrylate monomer (a2) having hydroxyl group, vinyl acetate (a3) and maleic acid ester monomer (a4) A pressure-sensitive adhesive composition comprising a (meth) acrylic acid alkyl ester copolymer (A) and an isocyanate crosslinking agent (B) having two or more isocyanate groups,
A pressure-sensitive adhesive composition, wherein the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) has an acid value of less than 1 mgKOH / g and a weight average molecular weight of 150,000 to 500,000.
[2] In the above [1], the (meth) acrylate monomer (a2) having a hydroxyl group is at least one selected from the group consisting of 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate. The pressure-sensitive adhesive composition described.
[3] The vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) is 40% by mass to 99.7% by mass of (meth) acrylic acid alkyl ester monomer (a1), 0.1% by mass to (Meth) acrylate monomer (a2) having 30% by mass of hydroxyl group, 0.1% by mass to 50% by mass of vinyl acetate (a3) and 0.1% by mass to 30% by mass of maleate ester monomer (a4) The pressure-sensitive adhesive composition according to [1] or [2], which is obtained by copolymerization.
[4] The isocyanate cross-linking agent (B) is contained in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A). [1] The adhesive composition as described in any one of [3].
[5] A pressure-sensitive adhesive composition for a releasable pressure-sensitive adhesive tape, comprising the pressure-sensitive adhesive composition according to any one of [1] to [4].
[6] A releasable pressure-sensitive adhesive tape, wherein a pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition for a releasable pressure-sensitive adhesive tape according to [5] is formed on at least one surface of a nonwoven fabric core material. .
[7] A releasable pressure-sensitive adhesive double-sided tape, wherein a pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition for re-peelable pressure-sensitive adhesive tape according to [5] is formed on both surfaces of a nonwoven fabric core material.
[8] The releasable pressure-sensitive adhesive double-sided tape according to [7], wherein the nonwoven fabric core has a basis weight of 10 g / m 2 to 30 g / m 2 .
本発明によれば、粘着力及び保持力が優れ、不織布芯材、特に高坪量の不織布芯材への染み込み性が良く、剥離の際に被着体を汚染することがなく剥離可能な再剥離型粘着両面テープに好適に用いることができる粘着剤組成物を提供することができる。
According to the present invention, the adhesive strength and holding power are excellent, the penetration into a nonwoven fabric core material, in particular, a high basis weight nonwoven fabric core material is good, and it is possible to peel the substrate without contaminating the adherend. An adhesive composition that can be suitably used for a peelable double-sided adhesive tape can be provided.
以下に、本発明を詳細に説明する。
本発明の粘着剤組成物は、酸価が１ｍｇＫＯＨ／ｇ未満のビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）と、イソシアネート架橋剤（Ｂ）とを主成分とするものである。なお、本発明において、（メタ）アクリルとは、メタクリル又はアクリルを意味する。 The present invention is described in detail below.
The pressure-sensitive adhesive composition of the present invention comprises a vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) having an acid value of less than 1 mgKOH / g and an isocyanate crosslinking agent (B) as main components. . In the present invention, (meth) acryl means methacryl or acryl.
本発明の粘着剤組成物は、酸価が１ｍｇＫＯＨ／ｇ未満のビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）と、イソシアネート架橋剤（Ｂ）とを主成分とするものである。なお、本発明において、（メタ）アクリルとは、メタクリル又はアクリルを意味する。 The present invention is described in detail below.
The pressure-sensitive adhesive composition of the present invention comprises a vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) having an acid value of less than 1 mgKOH / g and an isocyanate crosslinking agent (B) as main components. . In the present invention, (meth) acryl means methacryl or acryl.
ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）は、（メタ）アクリル酸アルキルエステルモノマー（ａ１）と、水酸基を有する（メタ）アクリレートモノマー（ａ２）と、酢酸ビニル（ａ３）と、マレイン酸エステルモノマー（ａ４）とを共重合させることにより得られるものである。なお、本発明において、（メタ）アクリレートとは、アクリレート又はメタクリレートを意味する。
The vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) comprises a (meth) acrylic acid alkyl ester monomer (a1), a (meth) acrylate monomer (a2) having a hydroxyl group, vinyl acetate (a3), And a maleic ester monomer (a4). In the present invention, (meth) acrylate means acrylate or methacrylate.
（メタ）アクリル酸アルキルエステルモノマー（ａ１）は、水酸基を含まない（メタ）アクリル酸のアルキルエステルであり、アルキル基の炭素数が、通常１～２０であるもの、好ましくは１～１２であるもの、より好ましくは１～８であるもの、最も好ましくは４～８であるものである。（メタ）アクリル酸アルキルエステルモノマー（ａ１）の具体例としては、メチル（メタ）アクリレート、エチル（メタ）アクリレート、ｎ－ブチル（メタ）アクリレート、ｉｓｏ－ブチル（メタ）アクリレート、ｔｅｒｔ－ブチル（メタ）アクリレート、ｎ－プロピル（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、イソデシル（メタ）アクリレート、ラウリル（メタ）アクリレート、セチル（メタ）アクリレート、ステアリル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、イソボルニル（メタ）アクリレートなどが挙げられる。これらのモノマーは、単独であるいは２種以上を併せて用いることができる。
The (meth) acrylic acid alkyl ester monomer (a1) is an alkyl ester of (meth) acrylic acid that does not contain a hydroxyl group, and the alkyl group usually has 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms. More preferably 1-8, most preferably 4-8. Specific examples of the (meth) acrylic acid alkyl ester monomer (a1) include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meta ) Acrylate, n-propyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) ) Acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate and the like. These monomers can be used alone or in combination of two or more.
（メタ）アクリル酸アルキルエステルモノマー（ａ１）の中でも、共重合性、粘着物性、取り扱い易さ及び原料入手のし易さの点で、ｎ－ブチル（メタ）アクリレート、２－エチルヘキシル（メタ）アクリレート及びメチルメタアクリレートが好ましく、更に耐熱性に優れる点で、ｎ－ブチル（メタ）アクリレート及びメチルメタアクリレートがより好ましい。
Among the (meth) acrylic acid alkyl ester monomers (a1), n-butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate are preferred in terms of copolymerizability, adhesive properties, ease of handling, and availability of raw materials. And methyl methacrylate are preferable, and n-butyl (meth) acrylate and methyl methacrylate are more preferable in view of excellent heat resistance.
水酸基を有する（メタ）アクリレートモノマー（ａ２）は、水酸基及び（メタ）アクリロイル基を有するモノマーであり、例えば、２－ヒドロキシエチル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレート、５－ヒドロキシペンチル（メタ）アクリレート、６－ヒドロキシヘキシル（メタ）アクリレート、８－ヒドロキシオクチル（メタ）アクリレートなどのアクリル酸ヒドロキシアルキルエステル、カプロラクトン変性２－ヒドロキシエチル（メタ）アクリレートなどのカプロラクトン変性モノマー、ジエチレングリコール（メタ）アクリレート、ポリエチレングリコール（メタ）アクリレートなどのオキシアルキレン変性モノマー、２－アクリロイロキシエチル２－ヒドロキシエチルフタル酸、Ｎ－メチロール（メタ）アクリルアミドなどの１級水酸基含有モノマー、２－ヒドロキシプロピル（メタ）アクリレート、２－ヒドロキシブチル（メタ）アクリレート、２－ヒドロキシ３－フェノキシプロピル（メタ）アクリレート、３－クロロ２－ヒドロキシプロピル（メタ）アクリレート、２－ヒドロキシ３－フェノキシプロピル（メタ）アクリレートなどの２級水酸基含有モノマー、２，２－ジメチル２－ヒドロキシエチル（メタ）アクリレートなどの３級水酸基含有モノマーが挙げられる。これらのモノマーは、単独であるいは２種以上を併せて用いることができる。
The (meth) acrylate monomer (a2) having a hydroxyl group is a monomer having a hydroxyl group and a (meth) acryloyl group, and examples thereof include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 5-hydroxypentyl. Hydroxyalkyl esters of acrylic acid such as (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, caprolactone-modified monomers such as caprolactone-modified 2-hydroxyethyl (meth) acrylate, diethylene glycol (meth) Oxyalkylene-modified monomers such as acrylate and polyethylene glycol (meth) acrylate, 2-acryloyloxyethyl 2-hydroxyethylphthalic acid, N-methylol (meta Primary hydroxyl group-containing monomers such as acrylamide, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate Secondary hydroxyl group-containing monomers such as 2-hydroxy-3-phenoxypropyl (meth) acrylate, and tertiary hydroxyl group-containing monomers such as 2,2-dimethyl 2-hydroxyethyl (meth) acrylate. These monomers can be used alone or in combination of two or more.
水酸基を有する（メタ）アクリレートモノマー（ａ２）の中でも、架橋剤との反応性に優れる点で、１級水酸基含有モノマーが好ましく、更に不純物が少なく、製造し易い点で、２－ヒドロキシエチル（メタ）アクリレートがより好ましい。
Of the (meth) acrylate monomer (a2) having a hydroxyl group, a primary hydroxyl group-containing monomer is preferable in terms of excellent reactivity with a crosslinking agent, and further, there are few impurities, and 2-hydroxyethyl (meta) ) Acrylate is more preferred.
マレイン酸エステルモノマー（ａ４）の具体例としては、マレイン酸ジメチル、マレイン酸ジエチル、マレイン酸ジイソプロピル、マレイン酸ジブチル、マレイン酸ジ２－エチルヘキシル、マレイン酸ジアリル、マレイン酸モノメチル、マレイン酸モノエチル、マレイン酸モノブチル、マレイン酸モノ２－エチルヘキシルなどが挙げられる。これらのモノマーは、単独であるいは２種以上を併せて用いることができる。
Specific examples of the maleate monomer (a4) include dimethyl maleate, diethyl maleate, diisopropyl maleate, dibutyl maleate, di-2-ethylhexyl maleate, diallyl maleate, monomethyl maleate, monoethyl maleate, maleic acid Examples thereof include monobutyl and mono-2-ethylhexyl maleate. These monomers can be used alone or in combination of two or more.
マレイン酸エステルモノマー（ａ４）の中でも、反応性、粘着剤特性の点で、マレイン酸ジメチル、マレイン酸ジエチル、マレイン酸ジブチル、マレイン酸ジ２－エチルヘキシル、マレイン酸ジアリルが好ましく、初期粘着力、再剥離性の点で、マレイン酸ジ２－エチルヘキシルがより好ましい。
Among the maleic acid ester monomers (a4), dimethyl maleate, diethyl maleate, dibutyl maleate, di-2-ethylhexyl maleate and diallyl maleate are preferred in terms of reactivity and pressure-sensitive adhesive properties. From the viewpoint of releasability, di-2-ethylhexyl maleate is more preferable.
ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）は、４０質量％～９９．７質量％のモノマー（ａ１）と、０．１質量％～３０質量％のモノマー（ａ２）と、０．１質量％～５０質量％の酢酸ビニル（ａ３）と、０．１質量％～３０質量％のモノマー（ａ４）とを共重合させたものであることが好ましく、５０質量％～９０質量％のモノマー（ａ１）と、０．２質量％～２０質量％のモノマー（ａ２）と、０．２質量％～４０質量％の酢酸ビニル（ａ３）と、０．２質量％～２０質量％のモノマー（ａ４）とを共重合させたものであることがより好ましく、５０質量％～８０質量％のモノマー（ａ１）と、０．３質量％～１０質量％のモノマー（ａ２）と、０．２質量％～３５質量％の酢酸ビニル（ａ３）と、０．２質量％～１０質量％のモノマー（ａ４）とを共重合させたものであることが更により好ましく、５５質量％～７０質量％のモノマー（ａ１）と、０．４質量％～５質量％のモノマー（ａ２）と、１０質量％～３５質量％の酢酸ビニル（ａ３）と、５質量％～１０質量％のモノマー（ａ４）とを共重合させたものであることが最も好ましい。
The vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) comprises 40% by mass to 99.7% by mass of the monomer (a1), 0.1% by mass to 30% by mass of the monomer (a2), It is preferable that 0.1% by mass to 50% by mass of vinyl acetate (a3) and 0.1% by mass to 30% by mass of monomer (a4) are copolymerized, and 50% by mass to 90% by mass. % Monomer (a1), 0.2% to 20% by weight monomer (a2), 0.2% to 40% by weight vinyl acetate (a3), 0.2% to 20% by weight It is more preferable that the monomer (a4) is copolymerized with 50% by mass to 80% by mass of the monomer (a1), 0.3% by mass to 10% by mass of the monomer (a2), and 0% by mass. 2% to 35% by weight of vinyl acetate (a3), 0.2% It is even more preferable that the monomer (a4) is copolymerized in an amount of 10% by mass to 10% by mass, and 55% by mass to 70% by mass of the monomer (a1) and 0.4% by mass to 5% by mass of the monomer (a4). Most preferably, the monomer (a2), 10% by mass to 35% by mass vinyl acetate (a3) and 5% by mass to 10% by mass monomer (a4) are copolymerized.
（メタ）アクリル酸アルキルエステルモノマー（ａ１）の使用量が９９．７質量％以下であれば、共重合体の凝集力が向上し、より良好な再剥離性を得ることができる。一方、（メタ）アクリル酸アルキルエステルモノマー（ａ１）の使用量が４０質量％以上であれば、共重合体の凝集力が適切となり、粘着力の低下が小さい。
水酸基を有する（メタ）アクリレートモノマー（ａ２）の使用量が３０質量％以下であれば、芯材への浸み込み性が適切となり、より良好な再剥離性を得ることができる。一方、水酸基を有する（メタ）アクリレートモノマー（ａ２）の使用量が０．１質量％以上であれば、水酸基の導入量が適切となり、架橋点が十分に確保されるため、より良好な保持力を得ることができる。
酢酸ビニル（ａ３）の使用量が５０質量％以下であれば、芯材への浸み込み性が適切となり、より良好な再剥離性を得ることができる。一方、酢酸ビニル（ａ３）の使用量が０．１質量％以上であれば、共重合体の凝集力が向上し、より良好な再剥離性を得ることができる。
マレイン酸エステルモノマー（ａ４）の使用量が３０質量％以下であれば、共重合体の凝集力が適切となり、粘着力の低下が小さい。一方、マレイン酸エステルモノマー（ａ４）の使用量が０．１質量％以上であれば、共重合体の凝集力が向上し、より良好な再剥離性を得ることができる。 When the amount of the (meth) acrylic acid alkyl ester monomer (a1) used is 99.7% by mass or less, the cohesive strength of the copolymer is improved, and better removability can be obtained. On the other hand, when the amount of the (meth) acrylic acid alkyl ester monomer (a1) used is 40% by mass or more, the cohesive strength of the copolymer becomes appropriate, and the decrease in adhesive strength is small.
If the usage-amount of the (meth) acrylate monomer (a2) which has a hydroxyl group is 30 mass% or less, the penetration property to a core material will become suitable, and more favorable removability can be obtained. On the other hand, when the amount of the (meth) acrylate monomer (a2) having a hydroxyl group is 0.1% by mass or more, the introduction amount of the hydroxyl group becomes appropriate, and a sufficient crosslinking point is secured. Can be obtained.
If the usage-amount of vinyl acetate (a3) is 50 mass% or less, the penetration property to a core material becomes appropriate, and more favorable removability can be obtained. On the other hand, if the usage-amount of vinyl acetate (a3) is 0.1 mass% or more, the cohesive force of a copolymer will improve and better removability can be obtained.
When the amount of the maleic ester monomer (a4) used is 30% by mass or less, the cohesive strength of the copolymer becomes appropriate and the decrease in adhesive strength is small. On the other hand, when the amount of the maleic ester monomer (a4) used is 0.1% by mass or more, the cohesive strength of the copolymer is improved, and better removability can be obtained.
水酸基を有する（メタ）アクリレートモノマー（ａ２）の使用量が３０質量％以下であれば、芯材への浸み込み性が適切となり、より良好な再剥離性を得ることができる。一方、水酸基を有する（メタ）アクリレートモノマー（ａ２）の使用量が０．１質量％以上であれば、水酸基の導入量が適切となり、架橋点が十分に確保されるため、より良好な保持力を得ることができる。
酢酸ビニル（ａ３）の使用量が５０質量％以下であれば、芯材への浸み込み性が適切となり、より良好な再剥離性を得ることができる。一方、酢酸ビニル（ａ３）の使用量が０．１質量％以上であれば、共重合体の凝集力が向上し、より良好な再剥離性を得ることができる。
マレイン酸エステルモノマー（ａ４）の使用量が３０質量％以下であれば、共重合体の凝集力が適切となり、粘着力の低下が小さい。一方、マレイン酸エステルモノマー（ａ４）の使用量が０．１質量％以上であれば、共重合体の凝集力が向上し、より良好な再剥離性を得ることができる。 When the amount of the (meth) acrylic acid alkyl ester monomer (a1) used is 99.7% by mass or less, the cohesive strength of the copolymer is improved, and better removability can be obtained. On the other hand, when the amount of the (meth) acrylic acid alkyl ester monomer (a1) used is 40% by mass or more, the cohesive strength of the copolymer becomes appropriate, and the decrease in adhesive strength is small.
If the usage-amount of the (meth) acrylate monomer (a2) which has a hydroxyl group is 30 mass% or less, the penetration property to a core material will become suitable, and more favorable removability can be obtained. On the other hand, when the amount of the (meth) acrylate monomer (a2) having a hydroxyl group is 0.1% by mass or more, the introduction amount of the hydroxyl group becomes appropriate, and a sufficient crosslinking point is secured. Can be obtained.
If the usage-amount of vinyl acetate (a3) is 50 mass% or less, the penetration property to a core material becomes appropriate, and more favorable removability can be obtained. On the other hand, if the usage-amount of vinyl acetate (a3) is 0.1 mass% or more, the cohesive force of a copolymer will improve and better removability can be obtained.
When the amount of the maleic ester monomer (a4) used is 30% by mass or less, the cohesive strength of the copolymer becomes appropriate and the decrease in adhesive strength is small. On the other hand, when the amount of the maleic ester monomer (a4) used is 0.1% by mass or more, the cohesive strength of the copolymer is improved, and better removability can be obtained.
ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）は、実質的にカルボキシル基を含まず、すなわち酸価が１ｍｇＫＯＨ／ｇ未満である。ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）は、好ましくはカルボキシル基を全く含まない。
なお、本発明において、共重合体（Ａ）の酸価はＪＩＳ Ｋ００７０に準拠して測定した値であり、例えば、以下のように測定する。
精密天秤で１００ｍｌ三角フラスコに試料約２ｇ程度を精秤し、これにエタノール／ジエチルエーテル＝１／１（質量比）の混合溶媒１０ｍｌを加えて溶解する。更に、この容器に指示薬としてフェノールフタレインエタノール溶液を１～３滴添加し、試料が均一になるまで充分に攪拌する。これを、０．１Ｎ水酸化カリウム－エタノール溶液で滴定し、指示薬のうすい紅色が３０秒間続いたときを、中和の終点とする。その結果から下記の計算式（１）を用いて得た値を、樹脂の酸価とする。
酸価（ｍｇＫＯＨ／ｇ）＝［Ｂ×ｆ×５．６１１］／Ｓ （１）
計算式（１）中、Ｂは、０．１Ｎ水酸化カリウム－エタノール溶液の使用量（ｍｌ）であり、ｆは、０．１Ｎ水酸化カリウム－エタノール溶液のファクターであり、Ｓは、試料の採取量（ｇ）である。 The vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) contains substantially no carboxyl group, that is, has an acid value of less than 1 mgKOH / g. The vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) preferably contains no carboxyl group.
In the present invention, the acid value of the copolymer (A) is a value measured according to JIS K0070, and is measured, for example, as follows.
About 2 g of a sample is precisely weighed into a 100 ml Erlenmeyer flask with a precision balance, and 10 ml of a mixed solvent of ethanol / diethyl ether = 1/1 (mass ratio) is added and dissolved therein. Furthermore, add 1 to 3 drops of a phenolphthalein ethanol solution as an indicator to the container, and stir well until the sample is uniform. This is titrated with a 0.1N potassium hydroxide-ethanol solution, and the end point of neutralization is when the light red color of the indicator lasts for 30 seconds. The value obtained from the result using the following formula (1) is defined as the acid value of the resin.
Acid value (mgKOH / g) = [B × f × 5.611] / S (1)
In the calculation formula (1), B is the amount (ml) of 0.1N potassium hydroxide-ethanol solution used, f is the factor of 0.1N potassium hydroxide-ethanol solution, and S is the sample The amount collected (g).
なお、本発明において、共重合体（Ａ）の酸価はＪＩＳ Ｋ００７０に準拠して測定した値であり、例えば、以下のように測定する。
精密天秤で１００ｍｌ三角フラスコに試料約２ｇ程度を精秤し、これにエタノール／ジエチルエーテル＝１／１（質量比）の混合溶媒１０ｍｌを加えて溶解する。更に、この容器に指示薬としてフェノールフタレインエタノール溶液を１～３滴添加し、試料が均一になるまで充分に攪拌する。これを、０．１Ｎ水酸化カリウム－エタノール溶液で滴定し、指示薬のうすい紅色が３０秒間続いたときを、中和の終点とする。その結果から下記の計算式（１）を用いて得た値を、樹脂の酸価とする。
酸価（ｍｇＫＯＨ／ｇ）＝［Ｂ×ｆ×５．６１１］／Ｓ （１）
計算式（１）中、Ｂは、０．１Ｎ水酸化カリウム－エタノール溶液の使用量（ｍｌ）であり、ｆは、０．１Ｎ水酸化カリウム－エタノール溶液のファクターであり、Ｓは、試料の採取量（ｇ）である。 The vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) contains substantially no carboxyl group, that is, has an acid value of less than 1 mgKOH / g. The vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) preferably contains no carboxyl group.
In the present invention, the acid value of the copolymer (A) is a value measured according to JIS K0070, and is measured, for example, as follows.
About 2 g of a sample is precisely weighed into a 100 ml Erlenmeyer flask with a precision balance, and 10 ml of a mixed solvent of ethanol / diethyl ether = 1/1 (mass ratio) is added and dissolved therein. Furthermore, add 1 to 3 drops of a phenolphthalein ethanol solution as an indicator to the container, and stir well until the sample is uniform. This is titrated with a 0.1N potassium hydroxide-ethanol solution, and the end point of neutralization is when the light red color of the indicator lasts for 30 seconds. The value obtained from the result using the following formula (1) is defined as the acid value of the resin.
Acid value (mgKOH / g) = [B × f × 5.611] / S (1)
In the calculation formula (1), B is the amount (ml) of 0.1N potassium hydroxide-ethanol solution used, f is the factor of 0.1N potassium hydroxide-ethanol solution, and S is the sample The amount collected (g).
ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）の重量平均分子量は、１５万～５０万であることが必要であり、好ましくは２０万～４０万である。重量平均分子量が１５万未満であると、優れた保持力が得られず、一方、重量平均分子量が５０万を超えると、芯材への染み込み性が低下し、良好な再剥離性が得られない。
The weight average molecular weight of the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) needs to be 150,000 to 500,000, preferably 200,000 to 400,000. When the weight average molecular weight is less than 150,000, excellent holding power cannot be obtained. On the other hand, when the weight average molecular weight exceeds 500,000, the penetrability into the core material is lowered and good removability is obtained. Absent.
なお、本発明において、ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）の重量平均分子量は、ゲル・パーミエーション・クロマトグラフィー（昭和電工株式会社製「ショウデックス（商標） ＧＰＣ ＳＹＳＴＥＭ－１１」に、カラム：ショウデックス（商標） ＧＰＣ ＫＦ－８０６Ｌ（排除限界分子量：２×１０7、分離範囲：１００～２×１０7、理論段数：１０，０００段／本、充填剤：平均粒径１０μｍのスチレン－ジビニルベンゼン共重合体）を用い、試料：共重合体の０．５質量％テトラヒドロフラン溶液、展開溶媒：テトラヒドロフラン、カラム温度：４０℃、流量：２ｍＬ／分の条件で測定される標準ポリスチレン分子量換算による重量平均分子量である。
In the present invention, the weight average molecular weight of the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) is determined by gel permeation chromatography (“Showex (trademark) GPC SYSTEM— 11 ”, column: Shodex (trademark) GPC KF-806L (exclusion limit molecular weight: 2 × 10 7 , separation range: 100 to 2 × 10 7 , theoretical plate number: 10,000 plates / tube, packing material: average particle Styrene-divinylbenzene copolymer having a diameter of 10 μm), sample: 0.5% by mass tetrahydrofuran solution of copolymer, developing solvent: tetrahydrofuran, column temperature: 40 ° C., flow rate: 2 mL / min It is a weight average molecular weight in terms of standard polystyrene molecular weight.
ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）を得るための共重合反応は特に制限されず、通常のラジカル重合法を適用することができる。例えば、モノマー（ａ１）、モノマー（ａ２）、酢酸ビニル（ａ３）及びモノマー（ａ４）に２，２’－アゾビス（イソブチロニトリル）、過酸化ベンゾイルなどの重合開始剤を溶解させたものを有機溶剤中に滴下し、６０℃～１００℃で２時間～１０時間重合させることにより、（ａ１）～（ａ４）からなる共重合物の有機溶剤溶液が得られる。重合開始剤の使用量は、（ａ１）～（ａ４）の合計量１００質量部に対して、通常、０．０１質量部～１．０質量部、好ましくは０．０５質量部～０．５質量部である。
The copolymerization reaction for obtaining the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) is not particularly limited, and a normal radical polymerization method can be applied. For example, a monomer in which a polymerization initiator such as 2,2′-azobis (isobutyronitrile) or benzoyl peroxide is dissolved in the monomer (a1), the monomer (a2), the vinyl acetate (a3) and the monomer (a4). The solution is dropped into an organic solvent and polymerized at 60 to 100 ° C. for 2 to 10 hours to obtain an organic solvent solution of the copolymer comprising (a1) to (a4). The amount of the polymerization initiator used is usually 0.01 parts by weight to 1.0 parts by weight, preferably 0.05 parts by weight to 0.5 parts by weight with respect to 100 parts by weight as the total amount of (a1) to (a4). Part by mass.
重合に用いられる有機溶剤としては、例えば、酢酸メチル、酢酸エチル、アセト酢酸メチル、アセト酢酸エチルなどのエステル系溶剤、トルエン、キシレンなどの芳香族炭化水素類、ｎ－プロピルアルコール、ｉｓｏ－プロピルアルコールなどの脂肪族アルコール類、メチルエチルケトン、メチルイソブチルケトン、シクロヘキサノンなどのケトン類が挙げられる。これらの有機溶剤は、単独であるいは２種以上を併せて用いることができる。これらの有機溶剤の中でも、溶解性、乾燥性、環境面、価格などの点で、酢酸エチルが好ましい。
Examples of the organic solvent used for polymerization include ester solvents such as methyl acetate, ethyl acetate, methyl acetoacetate, and ethyl acetoacetate, aromatic hydrocarbons such as toluene and xylene, n-propyl alcohol, and iso-propyl alcohol. And aliphatic alcohols such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. These organic solvents can be used alone or in combination of two or more. Among these organic solvents, ethyl acetate is preferable in terms of solubility, drying properties, environmental aspects, price, and the like.
このようにして得られるビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）をイソシアネート架橋剤（Ｂ）と混合することにより、本発明の粘着剤組成物となる。なお、混合後、架橋反応が開始するが、常温では、架橋が充分に進行するためにはある程度時間を要する。
The pressure-sensitive adhesive composition of the present invention is obtained by mixing the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) thus obtained with the isocyanate crosslinking agent (B). Although the crosslinking reaction starts after mixing, it takes some time for crosslinking to proceed sufficiently at room temperature.
イソシアネート架橋剤（Ｂ）としては、水酸基と反応可能なイソシアナト基を１分子中に２つ以上有する化合物である。イソシアネート架橋剤（Ｂ）の具体例としては、２，４－トリレンジイソシアネート、２，６－トリレンジイソシアネート、水素化トリレンジイソシアネート、１，３－キシリレンジイソシアネート、１，４－キシリレンジイソシアネート、ヘキサメチレンジイソシアネート、ジフェニルメタン－４，４－ジイソシアネート、イソホロンジイソシアネート、１，３－ビス（イソシアナトメチル）シクロヘキサン、テトラメチルキシリレンジイソシアネート、１，５－ナフタレンジイソシアネート、トリフェニルメタントリイソシアネート、及びこれらのポリイソシアネート化合物とトリメチロールプロパンなどのポリオール化合物とのアダクト体、これらポリイソシアネート化合物のビュレット体やイソシアヌレート体などが挙げられる。
The isocyanate crosslinking agent (B) is a compound having two or more isocyanato groups capable of reacting with a hydroxyl group in one molecule. Specific examples of the isocyanate crosslinking agent (B) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hydrogenated tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, Hexamethylene diisocyanate, diphenylmethane-4,4-diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, tetramethylxylylene diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, and their poly Examples include adducts of isocyanate compounds and polyol compounds such as trimethylolpropane, burettes and isocyanurates of these polyisocyanate compounds.
イソシアネート架橋剤（Ｂ）の中でも、反応性の点で、２，４－トリレンジイソシアネート、２，６－トリレンジイソシアネート、ヘキサメチレンジイソシアネートが好ましく、粘着剤特性の点で、２，４－トリレンジイソシアネート、２，６－トリレンジイソシアネートがより好ましい。
Among the isocyanate crosslinking agents (B), 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, and hexamethylene diisocyanate are preferable in terms of reactivity, and 2,4-tolylene diene in terms of pressure-sensitive adhesive properties. More preferred are isocyanate and 2,6-tolylene diisocyanate.
イソシアネート架橋剤（Ｂ）の使用量は、ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）１００質量部に対して、０．１質量部～１０質量部であることが好ましく、０．５質量部～５質量部であることがより好ましく、１．０質量部～２．５質量部であることが最も好ましい。イソシアネート架橋剤（Ｂ）の使用量がビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）１００質量部に対して０．１質量部以上であれば、保持力が十分となり、より良好な耐熱性及び再剥離性を得ることができる。一方、イソシアネート架橋剤（Ｂ）の使用量がビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）１００質量部に対して１０質量部以下であれば、樹脂の柔軟性が確保され、芯材への染み込み性が向上し、より良好な再剥離性を得ることができる。
The amount of the isocyanate crosslinking agent (B) used is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A). More preferably, it is 5 to 5 parts by mass, and most preferably 1.0 to 2.5 parts by mass. If the amount of the isocyanate crosslinking agent (B) used is 0.1 parts by mass or more with respect to 100 parts by mass of the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A), the holding power becomes sufficient and better Heat resistance and removability can be obtained. On the other hand, if the amount of the isocyanate crosslinking agent (B) used is 10 parts by mass or less with respect to 100 parts by mass of the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A), the flexibility of the resin is ensured, Impregnation into the core material is improved and better removability can be obtained.
本発明の粘着剤組成物は、通常、４０質量％～９９．９質量％の不揮発分を含有することが好ましい。
なお、本発明において、不揮発分は、直径５ｃｍのアルミ皿に約１ｇの粘着剤組成物を秤量した後、１１０℃で５時間乾燥させて残分を秤量し、下記の式から算出される値である。ここでの揮発分は、酢酸エチル等である。
不揮発分（質量％）＝（残分の質量）／（初期の質量）×１００ In general, the pressure-sensitive adhesive composition of the present invention preferably contains 40% by mass to 99.9% by mass of a nonvolatile content.
In the present invention, the non-volatile content is a value calculated from the following formula by weighing about 1 g of the pressure-sensitive adhesive composition on an aluminum dish having a diameter of 5 cm and then drying the residue at 110 ° C. for 5 hours and weighing the residue. It is. The volatile matter here is ethyl acetate or the like.
Nonvolatile content (mass%) = (mass of residual) / (initial mass) × 100
なお、本発明において、不揮発分は、直径５ｃｍのアルミ皿に約１ｇの粘着剤組成物を秤量した後、１１０℃で５時間乾燥させて残分を秤量し、下記の式から算出される値である。ここでの揮発分は、酢酸エチル等である。
不揮発分（質量％）＝（残分の質量）／（初期の質量）×１００ In general, the pressure-sensitive adhesive composition of the present invention preferably contains 40% by mass to 99.9% by mass of a nonvolatile content.
In the present invention, the non-volatile content is a value calculated from the following formula by weighing about 1 g of the pressure-sensitive adhesive composition on an aluminum dish having a diameter of 5 cm and then drying the residue at 110 ° C. for 5 hours and weighing the residue. It is. The volatile matter here is ethyl acetate or the like.
Nonvolatile content (mass%) = (mass of residual) / (initial mass) × 100
また、本発明の粘着剤組成物には、本発明の効果を損なわない範囲で、帯電防止剤、その他のアクリル系粘着剤、ロジン、ロジンエステル、水添ロジンエステル、芳香族変性テルペン樹脂、フェノール樹脂、キシレン樹脂、スチレン樹脂、クマロン樹脂、脂肪族系石油樹脂、脂環族系石油樹脂などの粘着付与剤、着色剤、充填剤、老化防止剤、紫外線吸収剤などの各種添加剤を添加してもよい。
In addition, the pressure-sensitive adhesive composition of the present invention includes an antistatic agent, other acrylic pressure-sensitive adhesives, rosin, rosin ester, hydrogenated rosin ester, aromatic modified terpene resin, phenol as long as the effects of the present invention are not impaired. Various additives such as tackifiers such as resins, xylene resins, styrene resins, coumarone resins, aliphatic petroleum resins, alicyclic petroleum resins, coloring agents, fillers, anti-aging agents, and UV absorbers are added. May be.
本発明の粘着剤組成物を塗布して粘着剤層を設けるための不織布芯材としては、レーヨン、パルプ、麻、ビニロンなどの繊維を用いる湿式不織布、長繊維であるポリエステル、ポリプロピレン、ポリエチレン、ナイロンなどの合成樹脂繊維を主として用いる、乾式不織布、スパンボンド、ニードルパンチ、ウォーターパンチ、スパンレースなどが挙げられる。不織布芯材は、１種類の繊維から構成されるものであってもよいし、２種以上の繊維から構成されるものであってもよい。不織布芯材の坪量は、十分な強度を確保し、層間破壊を抑制する点で、１０ｇ／ｍ2～３０ｇ／ｍ2であることが好ましく、１２ｇ／ｍ2～２８ｇ／ｍ2であることがより好ましく、１４ｇ／ｍ2～２６ｇ／ｍ2であることが最も好ましい。また、不織布芯材の厚みは、用途に応じて１５μｍ～１２５μｍの範囲で適宜設定される。
The nonwoven fabric core material for applying the pressure-sensitive adhesive composition of the present invention to provide a pressure-sensitive adhesive layer includes wet nonwoven fabrics using fibers such as rayon, pulp, hemp, and vinylon, polyesters that are long fibers, polypropylene, polyethylene, and nylon. Examples thereof include dry nonwoven fabrics, spunbonds, needle punches, water punches, and spunlaces that mainly use synthetic resin fibers such as. The nonwoven fabric core material may be composed of one type of fiber, or may be composed of two or more types of fibers. The basis weight of the nonwoven fabric core is preferably 10 g / m 2 to 30 g / m 2 , and 12 g / m 2 to 28 g / m 2 in terms of ensuring sufficient strength and suppressing interlaminar fracture. Is more preferable, and it is most preferable that it is 14 g / m 2 to 26 g / m 2 . Further, the thickness of the nonwoven fabric core material is appropriately set in the range of 15 μm to 125 μm depending on the application.
本発明の粘着剤組成物からなる粘着剤層を形成する方法としては、不織布芯材の上に、粘着剤組成物を直接塗工して乾燥させる直接法、シリコーンなどで離型処理された紙、又はプラスチックフィルムなどの離型材の上に粘着剤組成物を塗工した後、乾燥により架橋させて粘着剤層を形成させた後、粘着剤層の上に不織布芯材を重ねて加圧し、不織布芯材上に粘着剤層を転写する転写法などが挙げられる。不織布芯材の両面に粘着剤層を形成した後、必要に応じてエージング処理を施してもよい。
As a method for forming the pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition of the present invention, a direct method in which the pressure-sensitive adhesive composition is directly coated on a nonwoven fabric core and dried, paper that has been subjected to mold release treatment with silicone or the like Or, after coating the pressure-sensitive adhesive composition on a release material such as a plastic film, after forming a pressure-sensitive adhesive layer by cross-linking by drying, and then pressurizing the nonwoven fabric core material on the pressure-sensitive adhesive layer, Examples thereof include a transfer method in which the pressure-sensitive adhesive layer is transferred onto the nonwoven fabric core material. After forming the pressure-sensitive adhesive layer on both surfaces of the nonwoven fabric core material, an aging treatment may be performed as necessary.
塗工方法としては、一般的な塗工方法であれば特に限定されることなく、例えば、ロールコーティング、ダイコーティング、グラビアコーティング、コンマコーティング、スクリーン印刷などを使用する方法が挙げられる。
The coating method is not particularly limited as long as it is a general coating method, and examples thereof include a method using roll coating, die coating, gravure coating, comma coating, screen printing and the like.
さらに、上記離型材としては、例えば、各種合成樹脂シート、紙、布、不織布などに離型処理を施したものを使用することができる。
Furthermore, as the release material, for example, various synthetic resin sheets, paper, cloth, non-woven fabric, etc., which have been subjected to release treatment can be used.
塗工後の乾燥条件としては、粘着剤組成物を乾燥させ架橋させることが可能であればよく、例えば、５０℃～１５０℃で１～５分間である。
The drying condition after coating is not particularly limited as long as the pressure-sensitive adhesive composition can be dried and cross-linked, for example, at 50 to 150 ° C. for 1 to 5 minutes.
エージング処理は、粘着物性のバランスをとるために行なうものであり、エージングの条件としては、通常室温（２５℃±５℃）～７０℃で１日～３０日であり、具体的には、２３℃で１日～２０日間あるいは４０℃で１日～７日間などの条件で行なえばよい。
The aging treatment is performed in order to balance the physical properties of the adhesive, and the aging conditions are usually from room temperature (25 ° C. ± 5 ° C.) to 70 ° C. for 1 day to 30 days. The treatment may be performed under conditions such as 1 day to 20 days at 40 ° C. or 1 day to 7 days at 40 ° C.
本発明の粘着剤組成物は、再剥離型粘着テープに用いることができ、特に再剥離型粘着両面テープ用に好適である。本発明の再剥離型粘着テープあるいは再剥離型粘着両面テープにおける粘着剤層の厚みは、５μｍ～２５０μｍが好ましく、５μｍ～１５０μｍがより好ましく、５μｍ～１００μｍが最も好ましい。粘着剤層の厚みが５μｍ以上であれば、粘着物性が安定し、より良好な粘着力を得ることができる。一方、粘着剤層の厚みが２５０μｍ以下であれば、粘着剤組成物の乾燥が容易となる。
The pressure-sensitive adhesive composition of the present invention can be used for a re-peelable pressure-sensitive adhesive tape, and is particularly suitable for a re-peelable pressure-sensitive adhesive double-sided tape. The thickness of the pressure-sensitive adhesive layer in the re-peelable pressure-sensitive adhesive tape or the re-peelable pressure-sensitive adhesive double-sided tape of the present invention is preferably 5 μm to 250 μm, more preferably 5 μm to 150 μm, and most preferably 5 μm to 100 μm. When the thickness of the pressure-sensitive adhesive layer is 5 μm or more, the physical properties of the pressure-sensitive adhesive are stabilized, and a better adhesive force can be obtained. On the other hand, if the thickness of the pressure-sensitive adhesive layer is 250 μm or less, the pressure-sensitive adhesive composition can be easily dried.
以下、実施例及び比較例により本発明をさらに具体的に説明するが、本発明はこれらに限定されるものではない。
Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these.
＜合成例１＞
温度計、攪拌機、滴下ロート及び還流冷却器を備えた反応器内に、酢酸エチル１７０質量部を仕込み、攪拌しながら７８℃に昇温させた。次いで、２－エチルヘキシルアクリレート １７６質量部、２－ヒドロキシエチルメタクリレート ４質量部、酢酸ビニル ９３質量部及びマレイン酸ジ２－エチルヘキシル ３０質量部に、２，２’－アゾビス（イソブチロニトリル）（以下、ＡＩＢＮと略記することがある）０．６質量部を溶解させた混合物を、反応器内に２時間かけて滴下した。さらに、重合途中に、酢酸エチル１０質量部にＡＩＢＮ ０．２質量部を溶解させた重合触媒液を逐次追加しながら７時間重合させた後、酢酸エチルで希釈し、冷却後、反応器からビニルエステル・（メタ）アクリル酸アルキルエステル共重合体溶液を取り出した。ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体の重量平均分子量は３６万であった。また、ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体溶液の不揮発分は５１質量％であった。ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体の酸価は０ｍｇＫＯＨ／ｇである。 <Synthesis Example 1>
In a reactor equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser, 170 parts by mass of ethyl acetate was charged and heated to 78 ° C. while stirring. Subsequently, 176 parts by mass of 2-ethylhexyl acrylate, 4 parts by mass of 2-hydroxyethyl methacrylate, 93 parts by mass of vinyl acetate and 30 parts by mass of di-2-ethylhexyl maleate were mixed with 2,2′-azobis (isobutyronitrile) The mixture in which 0.6 part by mass was dissolved (may be abbreviated as AIBN) was dropped into the reactor over 2 hours. Further, during the polymerization, the polymerization catalyst solution in which 0.2 parts by mass of AIBN was dissolved in 10 parts by mass of ethyl acetate was successively added for 7 hours, diluted with ethyl acetate, cooled, and then discharged from the reactor. The ester / (meth) acrylic acid alkyl ester copolymer solution was taken out. The weight average molecular weight of the vinyl ester / (meth) acrylic acid alkyl ester copolymer was 360,000. The nonvolatile content of the vinyl ester / (meth) acrylic acid alkyl ester copolymer solution was 51% by mass. The acid value of the vinyl ester / (meth) acrylic acid alkyl ester copolymer is 0 mgKOH / g.
温度計、攪拌機、滴下ロート及び還流冷却器を備えた反応器内に、酢酸エチル１７０質量部を仕込み、攪拌しながら７８℃に昇温させた。次いで、２－エチルヘキシルアクリレート １７６質量部、２－ヒドロキシエチルメタクリレート ４質量部、酢酸ビニル ９３質量部及びマレイン酸ジ２－エチルヘキシル ３０質量部に、２，２’－アゾビス（イソブチロニトリル）（以下、ＡＩＢＮと略記することがある）０．６質量部を溶解させた混合物を、反応器内に２時間かけて滴下した。さらに、重合途中に、酢酸エチル１０質量部にＡＩＢＮ ０．２質量部を溶解させた重合触媒液を逐次追加しながら７時間重合させた後、酢酸エチルで希釈し、冷却後、反応器からビニルエステル・（メタ）アクリル酸アルキルエステル共重合体溶液を取り出した。ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体の重量平均分子量は３６万であった。また、ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体溶液の不揮発分は５１質量％であった。ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体の酸価は０ｍｇＫＯＨ／ｇである。 <Synthesis Example 1>
In a reactor equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser, 170 parts by mass of ethyl acetate was charged and heated to 78 ° C. while stirring. Subsequently, 176 parts by mass of 2-ethylhexyl acrylate, 4 parts by mass of 2-hydroxyethyl methacrylate, 93 parts by mass of vinyl acetate and 30 parts by mass of di-2-ethylhexyl maleate were mixed with 2,2′-azobis (isobutyronitrile) The mixture in which 0.6 part by mass was dissolved (may be abbreviated as AIBN) was dropped into the reactor over 2 hours. Further, during the polymerization, the polymerization catalyst solution in which 0.2 parts by mass of AIBN was dissolved in 10 parts by mass of ethyl acetate was successively added for 7 hours, diluted with ethyl acetate, cooled, and then discharged from the reactor. The ester / (meth) acrylic acid alkyl ester copolymer solution was taken out. The weight average molecular weight of the vinyl ester / (meth) acrylic acid alkyl ester copolymer was 360,000. The nonvolatile content of the vinyl ester / (meth) acrylic acid alkyl ester copolymer solution was 51% by mass. The acid value of the vinyl ester / (meth) acrylic acid alkyl ester copolymer is 0 mgKOH / g.
＜合成例２～８＞
表１に示す成分及び配合量で合成例１と同様にして共重合体溶液を得た。得られた共重合体溶液の不揮発分及び重量平均分子量を表１に併せて示す。合成例３の共重合体の酸価は１ｍｇＫＯＨ／ｇ以上であるが、それ以外は０ｍｇＫＯＨ／ｇである。 <Synthesis Examples 2 to 8>
A copolymer solution was obtained in the same manner as in Synthesis Example 1 with the components and blending amounts shown in Table 1. The nonvolatile content and weight average molecular weight of the obtained copolymer solution are also shown in Table 1. The acid value of the copolymer of Synthesis Example 3 is 1 mgKOH / g or more, but the other is 0 mgKOH / g.
表１に示す成分及び配合量で合成例１と同様にして共重合体溶液を得た。得られた共重合体溶液の不揮発分及び重量平均分子量を表１に併せて示す。合成例３の共重合体の酸価は１ｍｇＫＯＨ／ｇ以上であるが、それ以外は０ｍｇＫＯＨ／ｇである。 <Synthesis Examples 2 to 8>
A copolymer solution was obtained in the same manner as in Synthesis Example 1 with the components and blending amounts shown in Table 1. The nonvolatile content and weight average molecular weight of the obtained copolymer solution are also shown in Table 1. The acid value of the copolymer of Synthesis Example 3 is 1 mgKOH / g or more, but the other is 0 mgKOH / g.
＜実施例１～４及び比較例１～５＞
次に、表２に示す配合量で合成例１～８の共重合体溶液に４５％のイソシアネート架橋剤（日本ポリウレタン工業株式会社製コロネート（登録商標）Ｌ－４５Ｅ）を添加して粘着剤組成物を調製した。 <Examples 1 to 4 and Comparative Examples 1 to 5>
Next, 45% isocyanate cross-linking agent (Coronate (registered trademark) L-45E manufactured by Nippon Polyurethane Industry Co., Ltd.) was added to the copolymer solutions of Synthesis Examples 1 to 8 in the blending amounts shown in Table 2 to form an adhesive composition. A product was prepared.
次に、表２に示す配合量で合成例１～８の共重合体溶液に４５％のイソシアネート架橋剤（日本ポリウレタン工業株式会社製コロネート（登録商標）Ｌ－４５Ｅ）を添加して粘着剤組成物を調製した。 <Examples 1 to 4 and Comparative Examples 1 to 5>
Next, 45% isocyanate cross-linking agent (Coronate (registered trademark) L-45E manufactured by Nippon Polyurethane Industry Co., Ltd.) was added to the copolymer solutions of Synthesis Examples 1 to 8 in the blending amounts shown in Table 2 to form an adhesive composition. A product was prepared.
このようにして得られた粘着剤組成物を用い、下記の方法に従って、両面テープを作製し、特性評価（初期粘着力、再剥離性、保持力及びボールタック）を行なった。その結果を表３及び４に示す。
Using the pressure-sensitive adhesive composition thus obtained, a double-sided tape was prepared according to the following method and subjected to characteristic evaluation (initial adhesive force, removability, holding force and ball tack). The results are shown in Tables 3 and 4.
＜特性評価＞
実施例１～４及び比較例１～５の粘着剤組成物を、離型紙上に乾燥後の厚みが７０μｍ～８０μｍとなるように塗工し、その後１０５℃の温度で３分間乾燥させ架橋させた。次いで、この離型紙上の粘着剤組成物をレーヨン不織布芯材（坪量１４ｇ／ｍ2又は２７ｇ／ｍ2）に重ねてからロールで圧着した。この操作をレーヨン不織布芯材のもう片面についても施した。その後、片面に２５μｍＰＥＴフィルムを貼り合せ、４０℃で３日養生し、レーヨン不織布を芯材とする両面テープを得た。 <Characteristic evaluation>
The pressure-sensitive adhesive compositions of Examples 1 to 4 and Comparative Examples 1 to 5 were coated on a release paper so that the thickness after drying was 70 μm to 80 μm, and then dried at 105 ° C. for 3 minutes for crosslinking. It was. Next, the pressure-sensitive adhesive composition on the release paper was laminated on a rayon nonwoven fabric core (basis weight 14 g / m 2 or 27 g / m 2 ) and then pressure-bonded with a roll. This operation was also performed on the other side of the rayon nonwoven core. Thereafter, a 25 μm PET film was bonded to one side and cured at 40 ° C. for 3 days to obtain a double-sided tape having a rayon nonwoven fabric as a core material.
実施例１～４及び比較例１～５の粘着剤組成物を、離型紙上に乾燥後の厚みが７０μｍ～８０μｍとなるように塗工し、その後１０５℃の温度で３分間乾燥させ架橋させた。次いで、この離型紙上の粘着剤組成物をレーヨン不織布芯材（坪量１４ｇ／ｍ2又は２７ｇ／ｍ2）に重ねてからロールで圧着した。この操作をレーヨン不織布芯材のもう片面についても施した。その後、片面に２５μｍＰＥＴフィルムを貼り合せ、４０℃で３日養生し、レーヨン不織布を芯材とする両面テープを得た。 <Characteristic evaluation>
The pressure-sensitive adhesive compositions of Examples 1 to 4 and Comparative Examples 1 to 5 were coated on a release paper so that the thickness after drying was 70 μm to 80 μm, and then dried at 105 ° C. for 3 minutes for crosslinking. It was. Next, the pressure-sensitive adhesive composition on the release paper was laminated on a rayon nonwoven fabric core (basis weight 14 g / m 2 or 27 g / m 2 ) and then pressure-bonded with a roll. This operation was also performed on the other side of the rayon nonwoven core. Thereafter, a 25 μm PET film was bonded to one side and cured at 40 ° C. for 3 days to obtain a double-sided tape having a rayon nonwoven fabric as a core material.
〔初期粘着力〕
得られた両面テープを、ＳＵＳ３０４研磨板に２３℃、５０％ＲＨにて、２ｋｇローラーを１往復させて接着させてから２０分後に、２３℃、５０％ＲＨの雰囲気下で３００ｍｍ／分の剥離速度での１８０度剥離強度（Ｎ／１０ｍｍ）を測定した。 [Initial adhesive strength]
The obtained double-sided tape was bonded to a SUS304 polishing plate at 23 ° C. and 50% RH by reciprocating a 2 kg roller once and then peeled off at 300 mm / min in an atmosphere of 23 ° C. and 50% RH. The 180 degree peel strength (N / 10 mm) at the speed was measured.
得られた両面テープを、ＳＵＳ３０４研磨板に２３℃、５０％ＲＨにて、２ｋｇローラーを１往復させて接着させてから２０分後に、２３℃、５０％ＲＨの雰囲気下で３００ｍｍ／分の剥離速度での１８０度剥離強度（Ｎ／１０ｍｍ）を測定した。 [Initial adhesive strength]
The obtained double-sided tape was bonded to a SUS304 polishing plate at 23 ° C. and 50% RH by reciprocating a 2 kg roller once and then peeled off at 300 mm / min in an atmosphere of 23 ° C. and 50% RH. The 180 degree peel strength (N / 10 mm) at the speed was measured.
〔再剥離性〕
得られた両面テープを、ＳＵＳ３０４研磨板に２３℃、５０％ＲＨにて、２ｋｇローラーを１往復させて貼合させ、６０℃、９０％ＲＨの恒温槽中で１日間放置した後、２３℃、５０％ＲＨの雰囲気下で１時間放置し、９０°の角度で、３００ｍｍ／分の剥離速度で剥離する。被着体表面の汚染度合いを目視観察し、以下の基準に従って評価した。
○：汚染は認められなかった
ＣＦ：糊残りが認められた
ＢＦ：芯材層間破壊が認められた [Removability]
The obtained double-sided tape was bonded to a SUS304 polishing plate by reciprocating a 2 kg roller at 23 ° C. and 50% RH and left in a constant temperature bath at 60 ° C. and 90% RH for 1 day, and then 23 ° C. , Left in an atmosphere of 50% RH for 1 hour, and peeled off at an angle of 90 ° at a peeling speed of 300 mm / min. The degree of contamination on the adherend surface was visually observed and evaluated according to the following criteria.
○: No contamination was observed CF: Adhesive residue was observed BF: Core material interlayer fracture was observed
得られた両面テープを、ＳＵＳ３０４研磨板に２３℃、５０％ＲＨにて、２ｋｇローラーを１往復させて貼合させ、６０℃、９０％ＲＨの恒温槽中で１日間放置した後、２３℃、５０％ＲＨの雰囲気下で１時間放置し、９０°の角度で、３００ｍｍ／分の剥離速度で剥離する。被着体表面の汚染度合いを目視観察し、以下の基準に従って評価した。
○：汚染は認められなかった
ＣＦ：糊残りが認められた
ＢＦ：芯材層間破壊が認められた [Removability]
The obtained double-sided tape was bonded to a SUS304 polishing plate by reciprocating a 2 kg roller at 23 ° C. and 50% RH and left in a constant temperature bath at 60 ° C. and 90% RH for 1 day, and then 23 ° C. , Left in an atmosphere of 50% RH for 1 hour, and peeled off at an angle of 90 ° at a peeling speed of 300 mm / min. The degree of contamination on the adherend surface was visually observed and evaluated according to the following criteria.
○: No contamination was observed CF: Adhesive residue was observed BF: Core material interlayer fracture was observed
〔保持力〕
得られた両面テープを、ステンレス板に貼り付け面積が２５ｍｍ×２５ｍｍになるように貼り付け、８０℃の条件下にて１ｋｇの荷重をかけて、ＪＩＳ Ｚ ０２３７の保持力測定法に準じて、落下時間を測定し、落下時間が２４時間を超えるものについては２４時間後のズレも測定した。 [Retention force]
The obtained double-sided tape was affixed to a stainless steel plate so that the area was 25 mm × 25 mm, and a load of 1 kg was applied under the condition of 80 ° C., according to the holding power measurement method of JIS Z 0237, The falling time was measured, and the deviation after 24 hours was measured for those whose dropping time exceeded 24 hours.
得られた両面テープを、ステンレス板に貼り付け面積が２５ｍｍ×２５ｍｍになるように貼り付け、８０℃の条件下にて１ｋｇの荷重をかけて、ＪＩＳ Ｚ ０２３７の保持力測定法に準じて、落下時間を測定し、落下時間が２４時間を超えるものについては２４時間後のズレも測定した。 [Retention force]
The obtained double-sided tape was affixed to a stainless steel plate so that the area was 25 mm × 25 mm, and a load of 1 kg was applied under the condition of 80 ° C., according to the holding power measurement method of JIS Z 0237, The falling time was measured, and the deviation after 24 hours was measured for those whose dropping time exceeded 24 hours.
〔ボールタック〕
得られた両面テープにおいて、Ｊ．ｄｏｗ式ボールタック測定機を用い、２３℃、５０％ＲＨの条件下にて、テストピース２５ｍｍ×１００ｍｍ、角度３０度で、テストピース上（粘着面）で停止する最大径のボールナンバーを測定した。なお、ボールナンバーの最大径が大きい程、被着体に対する初期密着性が大きいといえる。 [Ball tack]
In the obtained double-sided tape, J.M. Using a dow ball tack measuring machine, the ball number of the maximum diameter that stops on the test piece (adhesive surface) was measured at a test piece 25 mm × 100 mm and an angle of 30 degrees under the conditions of 23 ° C. and 50% RH. . It can be said that the larger the maximum diameter of the ball number, the greater the initial adhesion to the adherend.
得られた両面テープにおいて、Ｊ．ｄｏｗ式ボールタック測定機を用い、２３℃、５０％ＲＨの条件下にて、テストピース２５ｍｍ×１００ｍｍ、角度３０度で、テストピース上（粘着面）で停止する最大径のボールナンバーを測定した。なお、ボールナンバーの最大径が大きい程、被着体に対する初期密着性が大きいといえる。 [Ball tack]
In the obtained double-sided tape, J.M. Using a dow ball tack measuring machine, the ball number of the maximum diameter that stops on the test piece (adhesive surface) was measured at a test piece 25 mm × 100 mm and an angle of 30 degrees under the conditions of 23 ° C. and 50% RH. . It can be said that the larger the maximum diameter of the ball number, the greater the initial adhesion to the adherend.
上記結果から、実施例品は、適当量のイソシアネート架橋剤を配合した場合、優れる粘着力を有しながら、再剥離性も良好であった。さらに、凝集力に関してもズレが見られず問題のないものであった。
From the above results, when the appropriate amount of the isocyanate cross-linking agent was blended, the example product had excellent removability while having excellent adhesive strength. Furthermore, there was no problem with respect to the cohesive force without any deviation.
なお、本国際出願は、２０１３年１０月２３日に出願した日本国特許出願第２０１３－２２００３１号に基づく優先権を主張するものであり、この日本国特許出願の全内容を本国際出願に援用する。
Note that this international application claims priority based on Japanese Patent Application No. 2013-220031 filed on October 23, 2013, and the entire contents of this Japanese patent application are incorporated herein by reference. To do.
Claims (8)
- （メタ）アクリル酸アルキルエステルモノマー（ａ１）、水酸基を有する（メタ）アクリレートモノマー（ａ２）、酢酸ビニル（ａ３）及びマレイン酸エステルモノマー（ａ４）を共重合させて得られるビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）と、２つ以上のイソシアナト基を有するイソシアネート架橋剤（Ｂ）とを含む粘着剤組成物であって、
前記ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）の酸価が１ｍｇＫＯＨ／ｇ未満であり且つ重量平均分子量が１５万～５０万であることを特徴とする粘着剤組成物。 (Meth) acrylic acid alkyl ester monomer (a1), vinyl ester (meth) obtained by copolymerizing (meth) acrylate monomer (a2), vinyl acetate (a3) and maleic acid ester monomer (a4) having a hydroxyl group An adhesive composition comprising an alkyl acrylate copolymer (A) and an isocyanate crosslinking agent (B) having two or more isocyanate groups,
A pressure-sensitive adhesive composition, wherein the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) has an acid value of less than 1 mgKOH / g and a weight average molecular weight of 150,000 to 500,000. - 前記水酸基を有する（メタ）アクリレートモノマー（ａ２）が、２－ヒドロキシエチルアクリレート及び２－ヒドロキシエチルメタアクリレートからなる群から選択される少なくとも１種であることを特徴とする請求項１に記載の粘着剤組成物。 The pressure-sensitive adhesive according to claim 1, wherein the (meth) acrylate monomer (a2) having a hydroxyl group is at least one selected from the group consisting of 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate. Agent composition.
- 前記ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）が、４０質量％～９９．７質量％の（メタ）アクリル酸アルキルエステルモノマー（ａ１）、０．１質量％～３０質量％の水酸基を有する（メタ）アクリレートモノマー（ａ２）、０．１質量％～５０質量％の酢酸ビニル（ａ３）及び０．１質量％～３０質量％のマレイン酸エステルモノマー（ａ４）を共重合させて得られるものであることを特徴とする請求項１又は２に記載の粘着剤組成物。 The vinyl ester / (meth) acrylic acid alkyl ester copolymer (A) is 40% by mass to 99.7% by mass of (meth) acrylic acid alkyl ester monomer (a1), 0.1% by mass to 30% by mass. (Meth) acrylate monomer (a2) having a hydroxyl group of 0.1% by mass to 50% by mass of vinyl acetate (a3) and 0.1% by mass to 30% by mass of maleic ester monomer (a4) The pressure-sensitive adhesive composition according to claim 1, wherein the pressure-sensitive adhesive composition is obtained.
- 前記ビニルエステル・（メタ）アクリル酸アルキルエステル共重合体（Ａ）１００質量部に対して前記イソシアネート架橋剤（Ｂ）を０．１質量部～１０質量部含むことを特徴とする請求項１～３の何れか一項に記載の粘着剤組成物。 The isocyanate cross-linking agent (B) is contained in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of the vinyl ester / (meth) acrylic acid alkyl ester copolymer (A). 4. The pressure-sensitive adhesive composition according to any one of 3.
- 請求項１～４の何れか一項に記載の粘着剤組成物からなることを特徴とする再剥離型粘着テープ用粘着剤組成物。 A pressure-sensitive adhesive composition for a re-peelable pressure-sensitive adhesive tape, comprising the pressure-sensitive adhesive composition according to any one of claims 1 to 4.
- 請求項５に記載の再剥離型粘着テープ用粘着剤組成物を架橋して得られる粘着剤層を不織布芯材の少なくとも一方の面に形成したことを特徴とする再剥離型粘着テープ。 A re-peelable pressure-sensitive adhesive tape, wherein a pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition for a re-peelable pressure-sensitive adhesive tape according to claim 5 is formed on at least one surface of a nonwoven fabric core material.
- 請求項５に記載の再剥離型粘着テープ用粘着剤組成物を架橋して得られる粘着剤層を不織布芯材の両面に形成したことを特徴とする再剥離型粘着両面テープ。 6. A re-peelable pressure-sensitive adhesive double-sided tape, wherein the pressure-sensitive adhesive layer obtained by crosslinking the pressure-sensitive adhesive composition for re-peelable pressure-sensitive adhesive tape according to claim 5 is formed on both surfaces of a nonwoven fabric core material.
- 前記不織布芯材の坪量が、１０ｇ／ｍ2～３０ｇ／ｍ2であることを特徴とする請求項７に記載の再剥離型粘着両面テープ。 The re-peelable pressure-sensitive adhesive double-sided tape according to claim 7, wherein the nonwoven fabric core has a basis weight of 10 g / m 2 to 30 g / m 2 .
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| Application Number | Priority Date | Filing Date | Title |
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| JP2013220031A JP2016222741A (en) | 2013-10-23 | 2013-10-23 | Adhesive composition and re-peelable adhesive double-sided tape |
| JP2013-220031 | 2013-10-23 |
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| WO2015060210A1 true WO2015060210A1 (en) | 2015-04-30 |
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| WO2018025335A1 (en) * | 2016-08-02 | 2018-02-08 | 凸版印刷株式会社 | Coating fluid for pressure-sensitive adhesive, method for forming pressure-sensitive adhesive layer using same, and laminated film |
| WO2019075418A1 (en) * | 2017-10-12 | 2019-04-18 | Avery Dennison Corporation | Low outgassing clean adhesive |
| WO2020209212A1 (en) * | 2019-04-08 | 2020-10-15 | デンカ株式会社 | Method for producing adhesive tape |
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| JPH069934A (en) * | 1992-06-29 | 1994-01-18 | Sumitomo Chem Co Ltd | Pressure-sensitive adhesive composition |
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| JP2011168658A (en) * | 2010-02-17 | 2011-09-01 | Daio Paper Corp | Adhesive composition and adhesive sheet |
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| JPS62212484A (en) * | 1986-03-13 | 1987-09-18 | Daicel Chem Ind Ltd | Self-adhesive composition for removal of dust |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2018025335A1 (en) * | 2016-08-02 | 2018-02-08 | 凸版印刷株式会社 | Coating fluid for pressure-sensitive adhesive, method for forming pressure-sensitive adhesive layer using same, and laminated film |
| WO2019075418A1 (en) * | 2017-10-12 | 2019-04-18 | Avery Dennison Corporation | Low outgassing clean adhesive |
| CN111163938A (en) * | 2017-10-12 | 2020-05-15 | 艾利丹尼森公司 | Low-outgassing cleaning adhesive |
| CN111163938B (en) * | 2017-10-12 | 2022-09-09 | 艾利丹尼森公司 | Low-outgassing cleaning adhesive |
| US11541639B2 (en) | 2017-10-12 | 2023-01-03 | Avery Dennison Corporation | Low outgassing clean adhesive |
| WO2020209212A1 (en) * | 2019-04-08 | 2020-10-15 | デンカ株式会社 | Method for producing adhesive tape |
| JP7368459B2 (en) | 2019-04-08 | 2023-10-24 | デンカ株式会社 | Adhesive tape manufacturing method |
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