JP2015010150A - Curable composition for pressure-sensitive adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable composition for a pressure-sensitive adhesive, which has a high curing rate and is thus capable of quickly forming a pressure-sensitive adhesive layer, and to provide a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed using the curable composition for a pressure-sensitive adhesive.SOLUTION: The curable composition is used for a pressure-sensitive adhesive. As raw materials of the curable composition, there are used: (A) a monomer component which contains, as essential components, 6-hydroxyhexyl (meth)acrylate and a (meth)acrylic monomer represented by formula (I) (where Rrepresents a hydrogen atom or a methyl group, and Rrepresents a C1-C22 alkyl group); (B) a polymerization initiator; and (C) at least one functional group-containing compound selected from the group consisting of an isocyanate compound and an epoxy compound.

Description

  The present invention relates to a curable composition for pressure-sensitive adhesives. More specifically, the present invention relates to a curable composition for pressure-sensitive adhesives and a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed from the curable composition for pressure-sensitive adhesives. The curable composition for pressure-sensitive adhesives of the present invention can be suitably used as a pressure-sensitive adhesive. Examples of pressure-sensitive adhesive forms include pressure-sensitive adhesive sheets and pressure-sensitive adhesive films, masking agents, sealing agents, Examples thereof include a bonding agent and an insulating agent.

  Adhesives are generally natural rubber adhesives using natural rubber, synthetic rubber adhesives using synthetic rubber such as styrene-butadiene rubber, silicone adhesives and acrylic resins using silicone. Are roughly classified into acrylic adhesives. Among these pressure-sensitive adhesives, acrylic pressure-sensitive adhesives have a wide selection range of monomers used as raw materials for the pressure-sensitive acrylic pressure-sensitive adhesives and have a high degree of freedom in their selection. Since it can be controlled, it has the advantage that it is not necessary to use a tackifier required for rubber-based pressure-sensitive adhesives.

  Properties required for an acrylic pressure-sensitive adhesive include fluidity when applied to an adherend and agglomeration for preventing the adhesive layer formed by applying to the adherend from being peeled off from the adherend. There is power. In order to improve the fluidity when the acrylic pressure-sensitive adhesive is applied to the adherend, it is necessary to lower the glass transition temperature of the acrylic pressure-sensitive adhesive. 10 alkyl acrylate is used as a monomer component, and in order to enhance cohesion, hydroxyalkyl having 2 to 4 carbon atoms such as ethyl 2-hydroxyacrylate, propyl 3-hydroxyacrylate, and butyl 4-hydroxyacrylate. A composition for pressure-sensitive adhesives (for example, refer to Patent Document 1) or a pressure-sensitive adhesive composition (for example, see Patent Document 1) containing a copolymer in which an alkyl acrylate ester having a group is used as a monomer component and a polyfunctional crosslinking agent. Patent Document 2) [hereinafter referred to as an adhesive (for) composition] has been proposed.

  However, since the adhesive (for) composition has a low curing rate when an adhesive layer is formed using the adhesive (for) composition, industrial productivity such as an adhesive sheet having the adhesive layer. Has the disadvantage of being inferior.

JP-A-48-89234 JP 2003-049141 A

  The present invention has been made in view of the prior art, and uses a curable composition for pressure-sensitive adhesives and a curable composition for pressure-sensitive adhesives that have a high curing rate and can quickly form an adhesive layer. It is an object to provide a pressure-sensitive adhesive sheet having a formed pressure-sensitive adhesive layer.

The present invention
(1) A curable composition used for an adhesive, as a raw material of the curable composition,
(A) 6-hydroxyhexyl (meth) acrylate and formula (I):

(Wherein R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 22 carbon atoms)
A monomer component containing, as an essential component, a (meth) acrylic monomer represented by:
A curable composition for pressure-sensitive adhesives, wherein (B) a polymerization initiator and (C) at least one functional group-containing compound selected from the group consisting of an isocyanate compound and an epoxy compound are used;
(2) The curable composition for pressure-sensitive adhesives according to (1) above, comprising a (meth) acrylic polymer obtained by polymerizing a monomer component in the presence of a polymerization initiator and a functional group-containing compound, and (3) It is related with the adhesive sheet which has the adhesion layer by which the curable composition for adhesives as described in said (1) is apply | coated on the at least one surface of a base material, and the formed coating film is hardened | cured.

  In the present specification, “(meth) acrylate” means “acrylate” or “methacrylate”. “(Meth) acryl” means “acryl” or “methacryl”.

  According to the present invention, a pressure-sensitive adhesive sheet having a high curing rate and capable of forming a pressure-sensitive adhesive layer quickly, and a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed using the pressure-sensitive adhesive curable composition Provided.

The curable composition for pressure-sensitive adhesives of the present invention is a curable composition used for pressure-sensitive adhesives as described above, and as a raw material of the curable composition,
(A) 6-hydroxyhexyl (meth) acrylate and formula (I):

(Wherein R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 22 carbon atoms)
A monomer component containing, as an essential component, a (meth) acrylic monomer represented by:
(B) A polymerization initiator, and (C) at least one functional group-containing compound selected from the group consisting of an isocyanate compound and an epoxy compound are used.

  Thus, the curable composition for pressure-sensitive adhesives of the present invention is cured because the monomer component, the polymerization initiator and the functional group-containing compound are used as raw materials for the curable composition for pressure-sensitive adhesives. The speed is high, and the excellent effect that the adhesive layer can be formed quickly is exhibited.

  As described above, the monomer component contains 6-hydroxyhexyl (meth) acrylate and a (meth) acrylic monomer represented by the formula (I) as essential components.

  In the present invention, one major characteristic is that the monomer component contains 6-hydroxyhexyl (meth) acrylate. Thus, since the monomer component used in the present invention contains 6-hydroxyhexyl (meth) acrylate, the curable composition for pressure-sensitive adhesives of the present invention uses other hydroxyl group-containing (meth) acrylates. Compared with the case where it exists, the cure rate is high and it can form an adhesion layer rapidly.

  Therefore, since the curable composition for pressure-sensitive adhesives of the present invention has a high curing rate, when the curable composition for pressure-sensitive adhesives of the present invention is cured by heating, the heating temperature is lowered or the heating time is shortened. Since it is difficult to receive heat history, there is an advantage that it is difficult to be thermally denatured. Moreover, since the curable composition for pressure-sensitive adhesives of the present invention has a high curing rate, the curable composition for pressure-sensitive adhesives is cured by irradiating the curable composition for pressure-sensitive adhesives of the present invention with active energy rays. In this case, since the irradiation dose of the active energy ray can be reduced, it is possible to suppress denaturation such as coloring due to the irradiation of the active energy ray.

  The content of 6-hydroxyhexyl (meth) acrylate in the monomer component is preferably 0 from the viewpoint of increasing the adhesive strength of the adhesive layer formed using the curable composition for adhesives of the present invention and increasing the curing rate. 0.1% by mass or more, more preferably 5% by mass or more, further preferably 10% by mass or more, and still more preferably 15% by mass or more, and the curable composition for pressure-sensitive adhesives of the present invention is applied to an adherend. From the viewpoint of improving the fluidity at the time, it is preferably 50% by mass or less, more preferably 45% by mass or less, and further preferably 40% by mass or less.

  As the monomer component, a (meth) acrylic monomer represented by the formula (I) is used as an essential component other than 6-hydroxyhexyl (meth) acrylate.

In the (meth) acrylic monomer represented by the formula (I), R ¹ is a hydrogen atom or a methyl group. R ² is an alkyl group having 1 to 22 carbon atoms. The alkyl group having 1 to 22 carbon atoms may be a straight chain or a branched chain. Moreover, the C1-C22 alkyl group may have ring structures, such as a cycloalkyl group, for example.

  Examples of the (meth) acrylic monomer represented by the formula (I) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, ( N-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, neopentyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) 2-ethylhexyl acrylate, n-heptyl (meth) acrylate, isoamyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, N-decyl (meth) acrylate, isodecyl (meth) acrylate, n- (meth) acrylate Examples include decyl, isomyristyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, and behenyl (meth) acrylate. The present invention is not limited to such examples. These (meth) acrylic monomers may be used alone or in combination of two or more.

  The content of the (meth) acrylic monomer represented by the formula (I) in the monomer component is preferably from the viewpoint of improving fluidity when the curable composition for pressure-sensitive adhesives of the present invention is applied to an adherend. Is 30% by mass or more, more preferably 35% by mass or more, further preferably 40% by mass or more, still more preferably 50% by mass or more, still more preferably 55% by mass or more, and particularly preferably 60% by mass or more. From the viewpoint of increasing the adhesive strength of the pressure-sensitive adhesive layer formed using the curable composition for pressure-sensitive adhesives of the present invention and increasing the curing rate, it is preferably 99.9% by mass or less, more preferably 95% by mass or less, and further preferably. Is 90% by mass or less, more preferably 85% by mass or less.

  It should be noted that the monomer component contains an ethylenically unsaturated copolymerizable with 6-hydroxyhexyl (meth) acrylate and (meth) acrylic monomer, if necessary, so that the total amount of the monomer component is 100% by mass. A monomer having a bond (hereinafter referred to as an ethylenically unsaturated bond-containing monomer) may be contained.

  Examples of the ethylenically unsaturated bond-containing monomer include monofunctional ethylenically unsaturated bond-containing monomers and polyfunctional ethylenically unsaturated bond-containing monomers, which may be used alone or in combination. Good.

  Monofunctional ethylenically unsaturated bond-containing monomers include, for example, (meth) acrylic acid, tetrahydrofurfuryl (meth) acrylate, ethyl carbitol (meth) acrylate, methoxyethyl (meth) acrylate, (meth) Methoxybutyl acrylate, benzyl (meth) acrylate, butoxymethyl (meth) acrylate, lauroxypolyethylene glycol (meth) acrylate, butoxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, (meth) Isobornyl acrylate, allyl (meth) acrylate, glycidyl (meth) acrylate, trifluoroethyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, morpholine acrylate, (Meta) ak N, N-dimethylaminoethyl acrylate, N, N-dimethylaminopropyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-diethylaminopropyl (meth) acrylate, (meth) N-tert-butylaminoethyl acrylate, N-tert-butylaminopropyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N -Diethylaminoethyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide, N- (meth) acryloyloxymethyl-N, N-dimethylammonium-α-N-carboxybetaine, tert-butyl (meth) acrylamide, N-octyl (meth) acrylic Amide, styrene, vinyl pyrrolidone, dimethylacrylamide, methyl itaconate, ethyl itaconate, vinyl acetate, vinyl propionate, propyltrimethoxysilane (meth) acrylate, etc., but the present invention is limited to such examples only. It is not something. These monofunctional ethylenically unsaturated bond-containing monomers may be used alone or in combination of two or more.

  Examples of the polyfunctional ethylenically unsaturated bond-containing monomer include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and 1,9-nonanediol di (meth) acrylate. 2-n-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, methylenebisacrylamide, trimethylolpropane tri ( Examples include (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and tripentaerythritol (meth) acrylate, but the present invention is not limited to such examples. These polyfunctional ethylenically unsaturated bond-containing monomers may be used alone or in combination of two or more.

  The content of the ethylenically unsaturated bond-containing monomer in the monomer component is the balance of 6-hydroxyhexyl (meth) acrylate and (meth) acrylic monomer in the monomer component. However, it is preferably 20% by mass or less from the viewpoint of increasing the adhesive strength of the adhesive layer formed using the curable composition for an adhesive of the present invention and increasing the curing rate.

  In addition, when polymerizing a monomer component, in order to adjust the molecular weight of the (meth) acrylic-type polymer obtained by polymerizing the said monomer component, you may make a monomer component contain a chain transfer agent. Examples of chain transfer agents include mercapto group-containing compounds such as octyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, mercaptoethanol; thioglycolic acid, methyl thioglycolate, ethyl thioglycolate, propyl thioglycolate, thioglycolic acid Butyl, tert-butyl thioglycolate, 2-ethylhexyl thioglycolate, octyl thioglycolate, isooctyl thioglycolate, decyl thioglycolate, dodecyl thioglycolate, 3-mercapto-1-propanol, 3-mercapto-1, Examples include 3-propanediol, ethylene glycol thioglycolate, neopentyl glycol thioglycolate, and pentaerythritol thioglycolate. It is not limited only to the illustrated that. These chain transfer agents may be used alone or in combination of two or more. The amount of the chain transfer agent is preferably appropriately determined according to the molecular weight of the target (meth) acrylic polymer, and is not particularly limited, but is usually 0.1 to 20 mass per 100 parts by mass of the monomer component. Parts, more preferably 0.2 to 15 parts by mass, still more preferably 0.3 to 10 parts by mass.

  When the monomer component is polymerized, a polymerization initiator is used. The polymerization initiator can be selected according to the method for polymerizing the monomer component. For example, when the monomer component is thermally polymerized, a thermal polymerization initiator can be used, and when the monomer component is photopolymerized, a photopolymerization initiator can be used.

  Examples of the thermal polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2, 4-dimethylvaleronitrile), 2,2′-azobis (2-methylpropionic acid) dimethyl, 2,2′-azobis-2-methylbutyronitrile, 4,4′-azobis-4-cyanovaleric acid, azo Bisisovaleronitrile, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2 Azo-based polymerizations such as' -azobis (2-methylpropionamidine) disulfate, 2,2-azobis (N, N'-dimethyleneisobutylamidine) dihydrochloride Initiators; peroxide polymerization initiators such as diisobutyryl peroxide, tert-butyl peroxypivalate, dibenzoyl peroxide, dibenzoyl peroxide, lauroyl peroxide; redox polymerization initiators, etc. The present invention is not limited to such examples. These thermal polymerization initiators may be used alone or in combination of two or more.

  Examples of the photopolymerization initiator include acetophenone photopolymerization initiator, benzyl photopolymerization initiator, benzoin photopolymerization initiator, benzoin ether photopolymerization initiator, benzophenone photopolymerization initiator, and ketal photopolymerization initiator. Agents, α-ketol photopolymerization initiators, thioxanthone photopolymerization initiators, and the like, but the present invention is not limited to such examples. These photopolymerization initiators may be used alone or in combination of two or more.

  Examples of the acetophenone-based photopolymerization initiator include acetophenone, 4-tert-butyl-dichloroacetophenone, 4-phenoxydichloroacetophenone, methoxyacetophenone, and the like, but the present invention is not limited to such examples. . These acetophenone photopolymerization initiators may be used alone or in combination of two or more.

  Examples of the benzyl photopolymerization initiator include benzyl and 4,4'-dimethoxybenzyl, but the present invention is not limited to such examples. These benzyl photopolymerization initiators may be used alone or in combination of two or more.

  Examples of the benzoin-based photopolymerization initiator include benzoin, but the present invention is not limited to such examples. The benzoin photopolymerization initiators may be used alone or in combination of two or more.

  Examples of the benzoin ether photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, and benzoin isobutyl ether, but the present invention is not limited to such examples. Absent. These benzoin ether photopolymerization initiators may be used alone or in combination of two or more.

  Examples of the benzophenone-based photopolymerization initiator include benzophenone, 3,3′-dimethyl-4-methoxybenzophenone, and polyvinyl benzophenone, but the present invention is not limited to such examples. These benzophenone-based photopolymerization initiators may be used alone or in combination of two or more.

  Examples of the ketal photopolymerization initiator include benzyl dimethyl ketal and the like, but the present invention is not limited to such examples. The ketal photopolymerization initiators may be used alone or in combination of two or more.

  Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) -phenyl] -2-hydroxy-2-methylpropane-1- Although ON etc. are mentioned, this invention is not limited only to this illustration. These α-ketol photopolymerization initiators may be used alone or in combination of two or more.

  Examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, Examples include 2,4-diisopropylthioxanthone and dodecylthioxanthone, but the present invention is not limited to such examples. These thioxanthone photopolymerization initiators may be used alone or in combination of two or more.

  The amount of the polymerization initiator varies depending on the type of the polymerization initiator and cannot be determined unconditionally, but is usually preferably 0.01 to 20 parts by mass, more preferably 0.8 to 100 parts by mass of the monomer component. It is 05-15 mass parts.

  A (meth) acrylic polymer can be obtained by polymerizing the monomer component in the presence of a polymerization initiator.

  Examples of the method for polymerizing the monomer component include a bulk polymerization method, a solution polymerization method, an emulsion polymerization method, a suspension polymerization method, and the like, but the present invention is not limited to such examples.

  For example, when the monomer component is polymerized by a solution polymerization method, a solvent is used. Examples of the solvent include ester compounds such as ethyl acetate and n-butyl acetate; aromatic hydrocarbon compounds such as toluene and benzene; aliphatic hydrocarbon compounds such as n-hexane and n-heptane; cyclohexane and methylcyclohexane Examples of alicyclic hydrocarbon compounds; ketone compounds such as methyl ethyl ketone and methyl isobutyl ketone are included, but the present invention is not limited to such examples. These solvents may be used alone or in combination of two or more. The amount of the solvent is not particularly limited, and is usually preferably about 50 to 300 parts by mass per 100 parts by mass of the monomer component.

  A (meth) acrylic polymer is obtained by polymerizing the monomer component as described above. The obtained (meth) acrylic polymer can be suitably used for an adhesive.

  The weight average molecular weight of the (meth) acrylic polymer is preferably 1000 or more, more preferably 1500 or more, and still more preferably from the viewpoint of improving the adhesive strength of the adhesive layer formed with the curable composition for pressure-sensitive adhesives of the present invention. Is 2000 or more, and is preferably 30000 or less, more preferably 20000 or less, and still more preferably 10,000 or less, from the viewpoint of improving the adhesiveness of the adhesive layer formed of the curable composition for adhesives of the present invention. In addition, the weight average molecular weight of a (meth) acrylic-type polymer can be calculated | required in polystyrene conversion, for example with a gel permeation chromatography. More specifically, the weight average molecular weight of the (meth) acrylic polymer is determined by, for example, gel permeation chromatography [manufactured by Tosoh Corporation, product number: HLC-8220], and TSKgelGMH-H (20) × as a column. Two can be used, and tetrahydrofuran can be used as a solvent, and can be measured at a flow rate of about 0.5 mL / min.

  The glass transition temperature of the (meth) acrylic polymer is preferably 20 ° C. or less, more preferably −40 ° C. or less, from the viewpoint of improving the cohesive force of the adhesive layer at a temperature of room temperature or higher and improving the adhesive force. More preferably, it is -50 degrees C or less. In addition, it is preferable that the glass transition temperature of a (meth) acrylic-type polymer is normally -100 degreeC or more.

The glass transition temperature of the (meth) acrylic polymer is given by the formula:
1 / Tg = W ₁ / Tg ₁ + W ₂ / Tg ₂ +... + W _n / Tg _n
Wherein, Tg is glass transition temperature of the (meth) acrylic polymer (unit: K), Tg _i is the glass transition temperature of the homopolymer of monomer i (unit: K), W _i is the monomer i in the monomer component (Indicates mass fraction)
It is the value calculated | required based on Fox formula represented by these.

  The glass transition temperature of the homopolymer of monomer i is described in, for example, “Polymer Handbook, John Wiley & Sons, Inc., 4th edition, 1999”. ing.

  When the glass transition temperature of the homopolymer of monomer i is not described in the above document, for example, the glass transition temperature of the (meth) acrylic polymer should be measured using a differential scanning calorimeter or the like. Can do.

  Next, the composition for curable pressure-sensitive adhesives of the present invention can be obtained by mixing the (meth) acrylic polymer obtained above and a functional group-containing compound. In this case, for example, when a (meth) acrylic polymer is prepared by a solution polymerization method for the monomer component, the (meth) acrylic polymer solution obtained by solution polymerization of the monomer component can be used as it is. In addition, when mixing a (meth) acrylic-type polymer and a functional group containing compound, you may add an additive etc. as needed.

  The functional group-containing compound can be used for the purpose of adjusting the cohesive strength of the curable adhesive composition of the present invention. As the functional group-containing compound, at least one selected from the group consisting of an isocyanate compound and an epoxy compound is used.

  Examples of the isocyanate compound include tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate. , Polymethylene polyphenyl isocyanate, 2-isocyanatoethyl (meth) acrylate, and the like, but the present invention is not limited to such examples. These isocyanate compounds may be used alone or in combination of two or more.

  Examples of the epoxy compound include 1,4-butanediol diglycidyl ether, 1,5-hexadiene diepoxide, 1,7-octadiene diepoxide, neopentyl glycol diglycidyl ether, bisphenol A, ethylene glycol diglycidyl ether, Polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol glycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, diamine glycidyl amine, N, N, N ′, N′- Examples include tetraglycidyl-m-xylylenediamine and 1,3-bis (N, N′-diamineglycidylaminomethyl) cyclohexane. The present invention is not limited shown only to. These epoxy compounds may be used alone or in combination of two or more.

  Since the amount of the functional group-containing compound varies depending on the number of functional groups of the (meth) acrylic polymer, it cannot be determined unconditionally. The amount of the functional group-containing compound is stoichiometrically equivalent to a functional group that the (meth) acrylic polymer has, for example, a hydroxyl group. The amount of the functional group-containing compound per 100 parts by mass of the (meth) acrylic polymer is preferably from the viewpoint of improving the cohesive force of the adhesive layer formed by the curable adhesive composition of the present invention. 01 parts by mass or more, more preferably 0.02 parts by mass or more, more preferably 0.03 parts by mass or more, from the viewpoint of improving the adhesiveness of the adhesive layer formed by the curable adhesive composition of the present invention Therefore, it is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and still more preferably 10 parts by mass or less.

  As described above, the curable pressure-sensitive adhesive composition of the present invention can be obtained. However, the curable pressure-sensitive adhesive composition of the present invention contains additives as long as the purpose of the present invention is not hindered. It may be included. Examples of the additive include an ultraviolet absorber, a light stabilizer, a silane coupling agent, a crosslinking accelerator, a tackifier resin, an anti-aging agent, a filler, a colorant, an antioxidant, a plasticizer, a softener, and an interface. Examples include activators and solvents, but the present invention is not limited to such examples. These additives may be used alone or in combination of two or more.

  As a method for forming an adhesive layer comprising the curable adhesive composition of the present invention, for example, the curable adhesive composition of the present invention is applied on at least one surface of a substrate, and the formed coating film And a method of coating the curable pressure-sensitive adhesive composition of the present invention on a release liner and transferring the formed pressure-sensitive adhesive layer to a substrate, but the present invention is limited to such a method. It is not limited.

  When the curable adhesive composition of the present invention is applied to a substrate, for example, a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, a spray coater, a comma coater, A direct coater or the like can be used.

  Although the thickness after hardening of the adhesion layer formed by apply | coating the composition for curable adhesives of this invention to a base material is not specifically limited, Preferably it is preferably 10-200 micrometers, More preferably, it is 10-150 micrometers. More preferably, it is 10-100 micrometers.

  As a method of curing the formed coating film after applying the curable adhesive composition of the present invention on at least one surface of the substrate, for example, a method of thermally curing the coating film, Although the method etc. of hardening the said coating film by irradiating an active energy ray are mentioned, this invention is not limited only to this illustration.

  In the method of thermally curing the coating film, the curing temperature is not particularly limited, but is usually preferably 80 to 200 ° C, more preferably 100 to 160 ° C. Since the time required for thermosetting varies depending on the heating temperature and the like and cannot be determined unconditionally, the time required for the formed coating film to cure is usually selected. In addition, examples of the atmosphere for thermally curing the coating film include inert gases such as air, nitrogen gas, and argon gas. However, the present invention is not limited to such examples.

  In the method of curing the coating film by irradiating the coating film with active energy rays, examples of the active energy rays include ionizing radiation such as ultraviolet rays, infrared rays, electron beams, α rays, β rays, γ rays, microwaves, and the like. However, the present invention is not limited to such examples. Among the active energy rays, ultraviolet to visible light having a wavelength of 180 to 500 nm is preferable. Since the time for curing the coating film by irradiating the coating film with active energy rays differs depending on the type and intensity of the active energy rays, it cannot be determined unconditionally. The time required to cure is selected. Examples of the atmosphere when the coating film is cured by irradiating the coating film with active energy rays include inert gases such as air, nitrogen gas, and argon gas, but the present invention is only such examples. It is not limited to. When the coating film is cured by irradiating the coating film with active energy rays, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a chemical lamp, a black light lamp, a mercury-xenon lamp. Excimer lamps, short arc lamps, helium / cadmium lasers, argon lasers, excimer lasers, and the like can be used.

  If necessary, another adhesive layer may be formed of one layer or a plurality of layers on the upper surface of the adhesive layer. Examples of the pressure-sensitive adhesive used in other pressure-sensitive adhesive layers include urethane pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, polyester-based pressure-sensitive adhesives, polyamide-based pressure-sensitive adhesives, epoxy-based pressure-sensitive adhesives, and vinyl. Examples include alkyl ether-based pressure-sensitive adhesives and fluorine-based pressure-sensitive adhesives, but the present invention is not limited to such examples.

  Examples of the base material include cloth; paper; polyester resins such as polyethylene terephthalate; (meth) acrylic resins such as polymethyl methacrylate; polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymers, and cyclic olefin polymers. Sheet or film made of resin such as resin, polycarbonate, triacetyl cellulose, polysulfone, polyarylate, polyimide, polyvinyl chloride, polyvinyl acetate, etc., which may have a metal layer on the surface; cellophane; aluminum foil, copper foil And metal foils such as lead foils; rubber sheets and the like, but the present invention is not limited to such examples.

  Although the thickness of a base material is not specifically limited, Usually, it is preferable that it is about 10-80 micrometers. The surface of the base material may be subjected to, for example, physical treatment such as corona discharge treatment or plasma treatment, or chemical treatment such as undercoating treatment.

  The pressure-sensitive adhesive sheet obtained as described above has a pressure-sensitive adhesive layer on one side or both sides. Therefore, the pressure-sensitive adhesive sheet of the present invention may have a pressure-sensitive adhesive layer formed on only one surface thereof, or may have a pressure-sensitive adhesive layer formed on both surfaces thereof.

  Although the thickness of the adhesive sheet of this invention is not specifically limited, Usually, Preferably it is about 10-200 micrometers, More preferably, it is about 10-150 micrometers, More preferably, it is about 10-100 micrometers.

  A release sheet may be attached to the surface of the pressure-sensitive adhesive sheet of the present invention. When the pressure-sensitive adhesive layer is formed on both surfaces of the pressure-sensitive adhesive sheet of the present invention, a release sheet may be attached to the surface of each pressure-sensitive adhesive layer. The release sheet is used as a protective material for the adhesive layer, and is usually peeled off when the adhesive sheet is attached to an adherend.

  Examples of the release sheet include a base material having a release treatment layer; polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, chlorofluoroethylene-fluoride. Examples include low-adhesive base materials made of fluororesins such as vinylidene chloride copolymers; low-adhesive base materials made of nonpolar resins such as polyethylene and polypropylene, but the present invention is limited only to such examples. is not. Examples of the substrate having a release treatment layer include a resin film subjected to a surface treatment with a release treatment agent such as a silicone resin and a fluororesin, but the present invention is not limited to such examples. Absent.

  As described above, the pressure-sensitive adhesive sheet of the present invention is obtained. The pressure-sensitive adhesive sheet of the present invention is formed using the above-mentioned pressure-sensitive adhesive curable composition. The pressure-sensitive adhesive curable composition has a high curing rate and quickly forms a pressure-sensitive adhesive layer. An adhesive sheet can be manufactured.

  Next, the present invention will be described in more detail based on examples. However, the present invention is not limited to such examples.

Example 1
In a 500 mL five-necked flask equipped with a reflux condenser, a thermometer, a nitrogen gas inlet tube and a stirrer, 30.5 g of 6-hydroxyhexyl acrylate, 54.4 g of 2-ethylhexyl acrylate, n-butyl acrylate 15.1 g, 100 g of methyl isobutyl ketone as a solvent, and 2 g of 2-mercaptoethanol as a chain transfer agent were charged. After replacing the space in the flask with nitrogen gas, 10 g of 2,2′-azobisisobutyronitrile as a polymerization initiator was added to the flask, and then the contents of the flask were heated to 80 ° C. The polymerization was carried out by maintaining for 8 hours to obtain a polymer solution having a polymer content of 50% by mass.

  The weight average molecular weight of the polymer contained in the polymer solution obtained above was subjected to gel permeation chromatography [manufactured by Tosoh Corporation, product number: HLC-8220], and TSKgelGMH-H (20) × 2 as a column. Was used, and tetrahydrofuran was used as the solvent, and the polymer was measured at a flow rate of about 0.5 mL / min. The weight average molecular weight of the polymer was 5010.

  Next, 0.744 g of hexamethylene diisocyanate (an amount in which the isocyanate group of hexamethylene diisocyanate is equivalent to the hydroxyl group of the polymer) is added to 10 g of the polymer solution obtained above, and stirred so as to obtain a uniform composition. By doing, the curable composition for adhesives was obtained.

  The curable composition for pressure-sensitive adhesives obtained above was cast on a glass plate (width 20 mm, length 100 mm) so that the thickness after drying was 50 μm, and heated to 100 ° C. with a hot plate. After 30 minutes from the start of heating, the isocyanate content in the coating film formed on the surface of the glass plate was detected by the FTIR-ATR (total reflection absorption infrared spectroscopy) method to determine the reaction conversion rate. As a result, the reaction conversion rate was 90.2%.

  Next, the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet obtained above was bonded to a backing substrate and backed, and left for 30 minutes in an atmosphere at a temperature of 23 ° C. and a relative humidity of 50%. Thereafter, in accordance with JIS Z0237 (2000), using a tensile tester [manufactured by A & D, product number: RTG-1310] in an atmosphere of a temperature of 23 ° C. and a relative humidity of 50%, a tensile speed of 300 mm / min and a peeling angle of 180 ° The backing substrate was peeled off from the glass plate, and the adhesive strength at that time was examined. As a result, the adhesive force was 13.6N.

Example 2
In a 500 mL five-necked flask equipped with a reflux condenser, a thermometer, a nitrogen gas inlet tube and a stirrer, 38.5 g of 6-hydroxyhexyl acrylate, 45.3 g of 2-ethylhexyl acrylate, n-butyl acrylate 16.2 g, 100 g of methyl isobutyl ketone as a solvent, and 2 g of 2-mercaptoethanol as a chain transfer agent were charged. After replacing the space in the flask with nitrogen gas, 10 g of 2,2′-azobisisobutyronitrile as a polymerization initiator was added to the flask, and then the contents of the flask were heated to 80 ° C. The polymerization was carried out by maintaining for 8 hours to obtain a polymer solution having a polymer content of 50% by mass.

  When the weight average molecular weight of the polymer contained in the polymer solution obtained above was measured in the same manner as in Example 1, the weight average molecular weight of the polymer was 5530.

  Next, 0.940 g of hexamethylene diisocyanate (an amount in which the isocyanate group of hexamethylene diisocyanate is equivalent to the hydroxyl group of the polymer) is added to 10 g of the polymer solution obtained above, and stirred so as to obtain a uniform composition. By doing, the curable composition for adhesives was obtained.

  The curable composition for pressure-sensitive adhesives obtained above was cast on a glass plate (width 20 mm, length 100 mm) so that the thickness after drying was 50 μm, and heated to 100 ° C. with a hot plate. After 30 minutes from the start of heating, the isocyanate content in the coating film formed on the surface of the glass plate was detected by the FTIR-ATR (total reflection absorption infrared spectroscopy) method to determine the reaction conversion rate. As a result, the reaction conversion rate was 90.3%.

  Next, in the same manner as in Example 1, the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet obtained above was bonded to the backing substrate and backed, and the adhesive strength was examined. The adhesive strength was 13.7 N. Met.

Example 3
In a 500 mL five-necked flask equipped with a reflux condenser, a thermometer, a nitrogen gas inlet tube and a stirrer, 15.2 g of 6-hydroxyhexyl acrylate, 67.5 g of 2-ethylhexyl acrylate, n-butyl acrylate 17.3 g, 100 g of methyl isobutyl ketone as a solvent, and 2 g of 2-mercaptoethanol as a chain transfer agent were charged. After replacing the space in the flask with nitrogen gas, 10 g of 2,2′-azobisisobutyronitrile as a polymerization initiator was added to the flask, and then the contents of the flask were heated to 80 ° C. The polymerization was carried out by maintaining for 8 hours to obtain a polymer solution having a polymer content of 50% by mass.

  When the weight average molecular weight of the polymer contained in the polymer solution obtained above was measured in the same manner as in Example 1, the weight average molecular weight of the polymer was 4990.

  Next, 0.371 g of hexamethylene diisocyanate (amount in which the isocyanate group of hexamethylene diisocyanate is equivalent to the hydroxyl group of the polymer) is added to 10 g of the polymer solution obtained above, and stirred so as to obtain a uniform composition. By doing, the curable composition for adhesives was obtained.

  The curable composition for pressure-sensitive adhesives obtained above was cast on a glass plate (width 20 mm, length 100 mm) so that the thickness after drying was 50 μm, and heated to 100 ° C. with a hot plate. After 30 minutes from the start of heating, the isocyanate content in the coating film formed on the surface of the glass plate was detected by the FTIR-ATR (total reflection absorption infrared spectroscopy) method to determine the reaction conversion rate. As a result, the reaction conversion rate was 90.6%.

  Next, in the same manner as in Example 1, the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet obtained above was bonded to the backing substrate and backed, and the adhesive strength was examined. The adhesive strength was 12.8 N. Met.

Comparative Example 1
In a 500 mL five-necked flask equipped with a reflux condenser, a thermometer, a nitrogen gas inlet tube and a stirrer, 20.6 g of 2-hydroxyethyl acrylate, 62.1 g of 2-ethylhexyl acrylate, n-butyl acrylate 17.3 g, 100 g of methyl isobutyl ketone as a solvent, and 2 g of 2-mercaptoethanol as a chain transfer agent were charged. After replacing the space in the flask with nitrogen gas, 10 g of 2,2′-azobisisobutyronitrile was added to the flask, and then the contents of the flask were heated to 80 ° C. and the temperature was maintained for 8 hours. Thus, polymerization was carried out to obtain a polymer solution having a polymer content of 50% by mass.

  When the weight average molecular weight of the polymer contained in the polymer solution obtained above was measured in the same manner as in Example 1, the weight average molecular weight of the polymer was 5010.

  Next, 0.826 g of hexamethylene diisocyanate (an amount in which the isocyanate group of hexamethylene diisocyanate is equivalent to the hydroxyl group of the polymer) is added to 10 g of the polymer solution obtained above, and stirred so as to obtain a uniform composition. By doing, the curable composition for adhesives was obtained.

  The curable composition for pressure-sensitive adhesives obtained above was cast on a glass plate (width 20 mm, length 100 mm) so that the thickness after drying was 50 μm, and heated to 100 ° C. with a hot plate. After 30 minutes from the start of heating, the isocyanate content in the coating film formed on the surface of the glass plate was detected by FTIR-ATR to determine the reaction conversion rate. As a result, the reaction conversion rate was 76.0%.

  Next, in the same manner as in Example 1, when the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet obtained above was bonded to the backing substrate and backed, and the adhesive strength was examined, the adhesive strength was 10.3 N. Met.

Comparative Example 2
In a 500 mL five-necked flask equipped with a reflux condenser, a thermometer, a nitrogen gas inlet tube and a stirrer, 24.0 g of 2-hydroxybutyl acrylate, 58.8 g of 2-ethylhexyl acrylate, n-butyl acrylate 16.3 g, 100 g of methyl isobutyl ketone as a solvent, and 2 g of 2-mercaptoethanol as a chain transfer agent were charged. After replacing the space in the flask with nitrogen gas, 10 g of 2,2′-azobisisobutyronitrile was added to the flask, and then the contents of the flask were heated to 80 ° C. and the temperature was maintained for 8 hours. Thus, polymerization was carried out to obtain a polymer solution having a polymer content of 50% by mass.

  When the weight average molecular weight of the polymer contained in the polymer solution obtained above was measured in the same manner as in Example 1, the weight average molecular weight of the polymer was 5410.

  Next, 0.785 g of hexamethylene diisocyanate (an amount in which the isocyanate group of hexamethylene diisocyanate is equivalent to the hydroxyl group of the polymer) is added to 10 g of the polymer solution obtained above, and stirred so as to obtain a uniform composition. By doing, the curable composition for adhesives was obtained.

  The curable composition for pressure-sensitive adhesives obtained above was cast on a glass plate (width 20 mm, length 100 mm) so that the thickness after drying was 50 μm, and heated to 100 ° C. with a hot plate. After 30 minutes from the start of heating, the isocyanate content in the coating film formed on the surface of the glass plate was detected by FTIR-ATR to determine the reaction conversion rate. As a result, the reaction conversion rate was 86.9%.

  Next, in the same manner as in Example 1, the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet obtained above was bonded to the backing substrate and backed, and the adhesive strength was examined. The adhesive strength was 11.8 N. Met.

Comparative Example 3
In a 500 mL five-necked flask equipped with a reflux condenser, a thermometer, a nitrogen gas inlet tube and a stirrer, 24.9 g of 2-hydroxynonyl acrylate, 58.8 g of 2-ethylhexyl acrylate, n-butyl acrylate 16.3 g, 100 g of methyl isobutyl ketone as a solvent, and 2 g of 2-mercaptoethanol as a chain transfer agent were charged. After replacing the space in the flask with nitrogen gas, 10 g of 2,2′-azobisisobutyronitrile was added to the flask, and then the contents of the flask were heated to 80 ° C. and the temperature was maintained for 8 hours. Thus, polymerization was carried out to obtain a polymer solution having a polymer content of 50% by mass.

  When the weight average molecular weight of the polymer contained in the polymer solution obtained above was measured in the same manner as in Example 1, the weight average molecular weight of the polymer was 5410.

  Next, 0.693 g of hexamethylene diisocyanate (an amount in which the isocyanate group of hexamethylene diisocyanate is equivalent to the hydroxyl group of the polymer) is added to 10 g of the polymer solution obtained above, and stirred so as to obtain a uniform composition. By doing, the curable composition for adhesives was obtained.

  The curable composition for pressure-sensitive adhesives obtained above was cast on a glass plate (width 20 mm, length 100 mm) so that the thickness after drying was 50 μm, and heated to 100 ° C. with a hot plate. After 30 minutes from the start of heating, the isocyanate content in the coating film formed on the surface of the glass plate was detected by FTIR-ATR to determine the reaction conversion rate. As a result, the reaction conversion rate was 79.9%.

  Next, in the same manner as in Example 1, when the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet obtained above was bonded to a backing substrate and backed, and the adhesive strength was examined, the adhesive strength was 11.0 N. Met.

  From the above results, according to each example, a curable composition for pressure-sensitive adhesives having a high curing rate and capable of forming an adhesive layer quickly is obtained as compared with each comparative example. It turns out that the adhesive sheet in which the adhesion layer which has favorable adhesive force was formed can be obtained by using a curable composition.

  The pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer formed using the curable composition for pressure-sensitive adhesives of the present invention is, for example, an electrical component insulating tape, an electronic component taping tape, a masking tape at the time of exposure in a printed wiring board process, Masking tape during etching, masking tape during solder removal, masking tape during plating, masking tape during flux application, masking tape during soldering, audio magnetic tape connection tape, polishing during semiconductor manufacturing Tape for fixing the polishing cloth used, tape for fixing pellicles during back grinding and photoresist, tape for fixing during dicing, tape for adhesive processing of polarizing film for LCD screens, transparent conductive for touch panels Film adhesive tape, electromagnetic wave shielding tape Medical patch tape, surgical tape, adhesive bandage, patch test tape, display label tape, building curing tape, waterproof tape, packing adhesive sheet, stainless steel sheet surface protection tape, marking film, etc. It is expected to be used for various applications.

  Moreover, the curable composition for adhesives of this invention can also be used with forms, such as a masking agent, a sealing agent, a bonding agent, and an insulating agent.

Claims (3)

A curable composition used for an adhesive, as a raw material of the curable composition,
(A) 6-hydroxyhexyl (meth) acrylate and formula (I):

(Wherein R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 22 carbon atoms)
A monomer component containing, as an essential component, a (meth) acrylic monomer represented by:
A curable composition for pressure-sensitive adhesives, wherein (B) a polymerization initiator and (C) at least one functional group-containing compound selected from the group consisting of an isocyanate compound and an epoxy compound are used.   The curable composition for pressure-sensitive adhesives according to claim 1, comprising a (meth) acrylic polymer obtained by polymerizing a monomer component in the presence of a polymerization initiator and a functional group-containing compound.   A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer formed by applying the curable composition for pressure-sensitive adhesives according to claim 1 on at least one surface of a substrate and curing the formed coating film.