JP6584867B2 - Acryloyloxy group-containing compound adhesive - Google Patents

Description

  The present invention relates to an acryloyloxy group-containing compound-based pressure-sensitive adhesive. In more detail, this invention relates to the adhesive film which has an adhesive layer which consists of an acryloyloxy group containing compound type adhesive and the said acryloyloxy group containing compound type adhesive.

  In recent years, various acrylic pressure-sensitive adhesives have been proposed, and can be obtained, for example, by copolymerizing an alkyl (meth) acrylate having an alkyl group with 4 to 10 carbon atoms and another modified vinyl monomer. An acrylic pressure-sensitive adhesive mainly composed of an acrylic copolymer (for example, see Patent Document 1), a pressure-sensitive adhesive containing an acrylic resin containing a specific amount of an acrylate monomer having an alkyl group carbon number of 8 or more ( For example, Patent Document 2) has been proposed.

  However, since the pressure-sensitive adhesive does not have sufficient adhesive strength, in recent years, development of a pressure-sensitive adhesive having excellent adhesiveness has been desired.

JP 2000-053929 A JP 2000-265125 A

  This invention is made | formed in view of the said prior art, and makes it a subject to provide the adhesive film which has the adhesive which was excellent in adhesiveness, and the adhesive layer excellent in adhesiveness.

The present invention
(1) Formula (I):

And an acryloyloxy group-containing compound-based pressure-sensitive adhesive comprising a polymer obtained by polymerizing a monomer component containing an acryloyloxy group-containing compound represented by the formula (1): It is related with the adhesive film which has the adhesive layer formed from the containing compound type adhesive on the single side | surface or both surfaces of a film.

  The acryloyloxy group-containing compound-based pressure-sensitive adhesive of the present invention has an excellent effect of exhibiting excellent adhesiveness. Moreover, since the adhesive film of this invention is comprised with the acryloyloxy group containing compound type adhesive of this invention, it has the outstanding adhesiveness.

  As described above, the acryloyloxy group-containing compound-based adhesive of the present invention has the formula (I):

It contains the polymer obtained by polymerizing the monomer component containing the acryloyloxy group containing compound represented by these.

  The acryloyloxy group-containing compound represented by the formula (I) can be easily obtained industrially. The acryloyloxy group-containing compound represented by the formula (I) can be easily obtained commercially, and can be easily obtained from, for example, Osaka Organic Chemical Industry Co., Ltd.

  The monomer component contains an acryloyloxy group-containing compound represented by the formula (I) (hereinafter simply referred to as “acryloyloxy group-containing compound”). The content of the acryloyloxy group-containing compound in the monomer component is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more, from the viewpoint of improving the adhesiveness. 100% by mass. Therefore, the polymer used in the present invention may be a homopolymer of an acryloyloxy group-containing compound.

  The monomer component may contain a monomer other than the acryloyloxy group-containing compound as long as the object of the present invention is not impaired. The content of other monomers in the monomer component is preferably 30% by mass or less, more preferably 25% by mass or less, and still more preferably 20% by mass or less, from the viewpoint of improving the tackiness. %.

  As shown below, the type and amount of other monomers other than the acryloyloxy group-containing compound are such that the glass transition temperature of the polymer used in the pressure-sensitive adhesive is preferably 0 ° C. or lower, more preferably −5 ° C. or lower, It is desirable to select and use so that it may become -10 degrees C or less preferably.

  Examples of monomers other than the acryloyloxy group-containing compound include (meth) acrylic acid, alkyl (meth) acrylate, hydroxyl group-containing monomer, cyano group-containing monomer, heterocyclic ring-containing vinyl monomer, vinyl ester monomer, and aromatic vinyl monomer. Amide group-containing monomer, imide group-containing monomer, amino group-containing monomer, epoxy group-containing monomer, N-acryloylmorpholine, vinyl ether monomer, alkylene oxide group-containing monomer, etc., but the present invention is limited to such examples. It is not something. These monomers may be used alone or in combination of two or more.

  In the present invention, “(meth) acrylic acid” means “acrylic acid” or “methacrylic acid”, but acrylic acid and methacrylic acid may be used alone or in combination. “(Meth) acrylate” means “acrylate” or “methacrylate”, and acrylate and methacrylate may be used alone or in combination of two or more. “(Meth) acrylamide” means “acrylamide” or “methacrylamide”, but acrylamide and methacrylamide may be used alone or in combination of two or more.

  Among the alkyl (meth) acrylates, an alkyl (meth) acrylate having an alkyl group having 1 to 14 carbon atoms which may have an alicyclic structure is preferable from the viewpoint of improving the adhesiveness. Examples of the alkyl (meth) acrylate having an alkyl group having 1 to 14 carbon atoms which may have an alicyclic structure include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n- Butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate , Isooctyl (meth) acrylate, n-nonyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth) Acu Although the rate and the like, the present invention is not limited only to those exemplified. These alkyl (meth) acrylates may be used alone or in combination of two or more. Among these alkyl (meth) acrylates, alkyl (meth) acrylates having an alkyl group having 1 to 4 carbon atoms are preferable from the viewpoint of obtaining a pressure-sensitive adhesive having excellent adhesiveness.

  Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and 8-hydroxyoctyl (meta ) A hydroxyalkyl (meth) acrylate having a hydroxyalkyl group having 2 to 8 carbon atoms, such as acrylate, and the like can be mentioned, but the present invention is not limited only to such illustration. These hydroxyl group-containing monomers may be used alone or in combination of two or more. Among these hydroxyl group-containing monomers, a hydroxyalkyl (meth) acrylate having a hydroxyalkyl group having 2 to 8 carbon atoms is preferable from the viewpoint of obtaining a pressure-sensitive adhesive having excellent adhesion, and 2-hydroxyethyl (meth) acrylate. Is more preferable.

  Examples of the cyano group-containing monomer include acrylonitrile and methacrylonitrile, but the present invention is not limited to such examples. These cyano group-containing monomers may be used alone or in combination.

  Examples of the heterocyclic ring-containing vinyl monomer include N-vinyl-2-pyrrolidone, N-vinylcaprolactam, N-vinylpyridine, N-vinylpyrimidine, N-vinylpiperidone, N-vinylpyrrole, N-vinylimidazole, and N-vinyl. Oxazole, N-vinylpiperazine, (meth) acryloylmorpholine, and the like can be mentioned, but the present invention is not limited to such examples. These heterocyclic ring-containing vinyl monomers may be used alone or in combination.

  Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, vinyl laurate and the like, but the present invention is not limited to such examples. These vinyl ester monomers may be used alone or in combination of two or more.

  Examples of the aromatic vinyl monomer include styrene monomers such as styrene, chlorostyrene, chloromethylstyrene, and α-methylstyrene. However, the present invention is not limited to such examples. These aromatic vinyl monomers may be used alone or in combination of two or more.

  Examples of the amide group-containing monomer include (meth) acrylamide, diethyl (meth) acrylamide, N-vinylpyrrolidone, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, and N, N′-. Examples include methylene bis (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, and diacetone (meth) acrylamide, but the present invention is not limited to such examples. These amide group-containing monomers may be used alone or in combination of two or more.

  Examples of the imide group-containing monomer include cyclohexylmaleimide, isopropylmaleimide, N-cyclohexylmaleimide, and itaconimide, but the present invention is not limited to such examples. These imide group-containing monomers may be used alone or in combination of two or more.

  Examples of the amino group-containing monomer include aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, and the like. It is not limited to illustration only. These amino group-containing monomers may be used alone or in combination of two or more.

  Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, and allyl glycidyl ether, but the present invention is not limited to such examples. These epoxy group-containing monomers may be used alone or in combination of two or more.

  Examples of the vinyl ether monomer include methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, and the like, but the present invention is not limited to such examples. These vinyl ether monomers may be used alone or in combination of two or more.

  Examples of the alkylene oxide group-containing monomer include polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, polyethylene glycol-polypropylene glycol (meth) acrylate, polyethylene glycol-polybutylene glycol (meth) acrylate, and polypropylene glycol-polybutylene. Glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, ethoxypolyethyleneglycol (meth) acrylate, butoxypolyethyleneglycol (meth) acrylate, octoxypolyethyleneglycol (meth) acrylate, lauroxypolyethyleneglycol (meth) acrylate, stearoxy Polyethylene glycol (meth) acrylate Phenoxy polyethylene glycol (meth) acrylate, methoxy polypropylene glycol (meth) acrylate, octoxypolyethylene glycol - and polypropylene glycol (meth) acrylate, the present invention is not limited only to those exemplified. These alkylene oxide group-containing monomers may be used alone or in combination of two or more.

  Among the monomer components, from the viewpoint of obtaining a pressure-sensitive adhesive having excellent adhesion, 50 to 100% by mass of an acryloyloxy group-containing compound, 0 to 30% by mass of an alkyl (meth) acrylate having an alkyl group having 1 to 4 carbon atoms, and A monomer component containing 0 to 30% by mass of a hydroxyalkyl (meth) acrylate having a hydroxyalkyl group having 2 to 8 carbon atoms is preferred, an acryloyloxy group-containing compound of 60 to 100% by mass, and an alkyl group having 1 to 4 carbon atoms. A monomer component containing 0 to 20% by mass of alkyl (meth) acrylate having 0 and 0 to 20% by mass of 2-hydroxyethyl (meth) acrylate is more preferable.

  The polymer used for the acryloyloxy group-containing compound-based pressure-sensitive adhesive of the present invention may have a crosslinked structure. A polymer having a crosslinked structure can be obtained, for example, by allowing a monomer component used as a raw material of the polymer to contain a crosslinking agent and polymerizing the monomer component containing the crosslinking agent.

  Examples of the crosslinking agent include polyfunctional monomers. Examples of the polyfunctional monomer include aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate; 2,4-tolylene diisocyanate , 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, and the like; N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidyl) Epoxy compounds such as aminomethyl) cyclohexane; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate Plural such as relate, neopentyl glycol di (meth) acrylate, 1,6 hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate The (meth) acryloyloxy group-containing compound having (meth) acryloyloxy group; divinylbenzene, N, N′-methylenebisacrylamide, and the like are exemplified, but the present invention is not limited to such examples. These polyfunctional monomers may be used alone or in combination of two or more.

  The content of the polyfunctional monomer in the monomer component is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and further preferably 0.5% by mass or more from the viewpoint of sufficiently forming a crosslinked structure. From the viewpoint of increasing the cohesive strength of the pressure-sensitive adhesive, it is preferably 10% by mass or less, more preferably 5% by mass or less.

  Moreover, in order to adjust the molecular weight of the polymer used for the acryloyloxy group-containing compound-based pressure-sensitive adhesive of the present invention, a chain transfer agent may be contained in an appropriate amount in the monomer component. Examples of the chain transfer agent include thiol group-containing compounds such as lauryl mercaptan, dodecyl mercaptan, and thioglycerol, and inorganic salts such as sodium hypophosphite and sodium hydrogen sulfite. It is not limited. The amount of the chain transfer agent per 100 parts by mass of the monomer component is usually about 0.01 to 10 parts by mass.

  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.

  When the monomer component is polymerized by a solution polymerization method, a solvent can be used. Examples of the solvent include alcohol solvents such as methanol, ethanol, propyl alcohol, isopropyl alcohol, and butyl alcohol; hydrocarbon solvents such as hexane, heptane, octane, isooctane, decane, and liquid paraffin; dimethyl ether, diethyl ether, tetrahydrofuran, and the like. Ether solvents such as acetone and methyl ethyl ketone; ester solvents such as methyl acetate, ethyl acetate and butyl acetate; chloride solvents such as methylene chloride, chloroform and carbon tetrachloride; dimethylformamide, diethylformamide and dimethyl Examples thereof include sulfoxide and dioxane, but the present invention is not limited to such examples. These solvents may be used alone or in combination of two or more.

  Since the amount of the solvent varies depending on the composition of the monomer component, the type of the solvent, and the like, it cannot be generally limited, but is usually about 100 to 1000 parts by mass per 100 parts by mass of the monomer component.

  When the monomer component is polymerized, a polymerization initiator can be used. Examples of the polymerization initiator include a photopolymerization initiator and a thermal polymerization initiator. Some of the polymerization initiators can be used as either a photopolymerization initiator or a thermal polymerization initiator. The polymerization initiator can also be used as a photopolymerization initiator and a thermal polymerization initiator.

  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-hydroxy-2-methylpropiophenone, 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.

  Examples of the thermal polymerization initiator include azodiisobutyronitrile, 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, azobisisovaleronitrile, 2, 2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis (2-methyl) Propionamidine) disulfate, 2,2-azobis (N, N'-dimethyleneisobutylamidine) dihydrochloride and other azo polymerization initiators Examples include peroxide-based polymerization initiators such as diisobutyryl peroxide, tert-butylperoxypivalate, dibenzoyl peroxide, dibenzoyl peroxide, lauroyl peroxide; and redox-based polymerization initiators. However, the present invention is not limited to such examples. These thermal polymerization initiators may be used alone or in combination of two or more.

  Since the amount of the polymerization initiator varies depending on the type of the polymerization initiator and the like, it cannot be determined unconditionally. However, usually, it is preferably 0.01 to 15 parts by mass, more preferably 0 per 100 parts by mass of the monomer component. 5 to 10 parts by mass.

  The atmosphere for polymerizing the monomer component is not particularly limited, and may be air or an inert gas such as nitrogen gas or argon gas.

  The polymerization temperature of the monomer component is not particularly limited, and is usually preferably about 5 to 80 ° C. Since the time required for the polymerization of the monomer component varies depending on the polymerization conditions and the like, it cannot be determined unconditionally and is arbitrary. Usually, the polymerization reaction can be arbitrarily terminated when the amount of the remaining monomer is 10% by mass or less. The amount of the remaining monomer can be determined, for example, by adding oxalic acid to the double bond of the monomer and measuring the double bond content.

  A polymer is obtained by polymerizing the monomer component as described above. The weight average molecular weight of the polymer is preferably 100,000 or more, more preferably 200,000 or more, and still more preferably 300,000 or more from the viewpoint of increasing the cohesive strength of the pressure-sensitive adhesive, from the viewpoint of improving the coating property of the pressure-sensitive adhesive. , Preferably it is 5 million or less, More preferably, it is 4 million or less, More preferably, it is 3 million. When the monomer component contains a cross-linking agent, the polymer obtained has a cross-linked structure, so it is difficult to measure the weight average molecular weight of the polymer.

  In addition, in this invention, the weight average molecular weight of a polymer is a value when measured by polystyrene conversion using the Tosoh make, brand name: HLC-8220 GPC system (column: TSGgel G-4000HXL and TSGgel G-2000HXL). .

  The glass transition temperature of the polymer is preferably 0 ° C. or less, more preferably −5 ° C. or less, and still more preferably −10 ° C. or less from the viewpoint of improving the adhesiveness, and from the viewpoint of suppressing the fluidity of the adhesive. It is −50 ° C. or higher, more preferably −40 ° C. or higher, and further preferably −30 ° C. or higher. The glass transition temperature of the polymer can be easily adjusted by adjusting the composition of the monomer component.

  In the present invention, the glass transition temperature of the polymer is determined by using a differential scanning calorimeter [manufactured by Rigaku Corporation, product number: DSC8230], placing 7 mg of the sample (polymer) on an aluminum pan and 7 mg of aluminum oxide on the aluminum pan for control. Each is placed at a designated position in the oven, heated to 100 ° C. at a temperature start rate of 30 ° C. at a rate of temperature increase of 10 ° C./min, held at that temperature for 10 minutes, and −100 ° C. at a cooling rate of 10 ° C./min. It is a value measured when the measurement of the differential scanning calorific value is started and heated from −100 ° C. to 100 ° C. at a temperature rising rate of 10 ° C./min. Note that the oven is cooled to room temperature after measurement of the differential scanning calorific value.

  As an example of the glass transition temperature of the polymer, for example, the glass transition temperature of the homopolymer of the acryloyloxy group-containing compound is -37 ° C, the glass transition temperature of the homopolymer of butyl acrylate is -54 ° C, and n- The glass transition temperature of the homopolymer of octyl acrylate is −71 ° C., the glass transition temperature of the homopolymer of isodecyl acrylate is −62 ° C., the glass transition temperature of the homopolymer of lauryl acrylate is −23 ° C., Nonyl acrylate homopolymer has a glass transition temperature of −71 ° C., 2-ethylhexyl acrylate homopolymer has a glass transition temperature of −70 ° C., and isooctyl acrylate homopolymer has a glass transition temperature of −70 ° C. .

  A polymer can be obtained by polymerizing the monomer component as described above. The polymer may be used as it is. For example, in order to remove unreacted monomers, the polymer may be purified by a purification method such as distillation or extraction.

  The polymer obtained by polymerizing the monomer component can be used as an adhesive as it is. For example, when the monomer component is polymerized by a bulk polymerization method, the obtained polymer can be used as an adhesive, and when the monomer component is polymerized by a solution polymerization method, the obtained solution polymerization reaction The solution can be used as a pressure-sensitive adhesive, and when the monomer component is polymerized by an emulsion polymerization method, the resulting emulsion polymerization reaction solution can be used as the pressure-sensitive adhesive.

  In addition, you may add a solvent, an additive, etc. in a proper quantity to the acryloyloxy group containing compound type adhesive of this invention as needed. Examples of additives include colorants such as pigments, surfactants, plasticizers, tackifiers, leveling agents, antioxidants, corrosion inhibitors, light stabilizers, ultraviolet absorbers, polymerization inhibitors, and silane coupling agents. The present invention is not limited to only such examples.

  From the viewpoint of improving productivity, the solid content in the acryloyloxy group-containing compound-based pressure-sensitive adhesive of the present invention is preferably 20% by mass or more, more preferably 30% by mass or more, which improves coatability. From the viewpoint, it is preferably 80% by mass or less, more preferably 70% by mass or less. The resin solid content in the acryloyloxy group-containing compound-based pressure-sensitive adhesive of the present invention can be adjusted by adjusting the amount of solvent contained in the pressure-sensitive adhesive. As a solvent, the thing similar to the solvent used when carrying out solution polymerization of a monomer component can be illustrated.

  Since the acryloyloxy group-containing compound-based pressure-sensitive adhesive of the present invention obtained as described above is excellent in adhesiveness, it is expected to be used for applications such as adhesive films and masking tapes. is there. In the present specification, the adhesive film is a term having the same meaning as the adhesive sheet, and is a concept including the adhesive sheet.

  The pressure-sensitive adhesive film of the present invention can be obtained by forming a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive on one or both sides of the film.

  Examples of the method for forming the pressure-sensitive adhesive layer on the film include a method for forming the pressure-sensitive adhesive layer on the film by applying the pressure-sensitive adhesive on the film and drying it as necessary. However, the present invention is not limited to such examples. Examples of methods for applying the adhesive on the film include a roll coating method, a spray coating method, a flow coating method, a dipping method, a gravure coating method, a reverse coating method, a roll brush method, an air knife coating method, and a die coater method. However, the present invention is not limited to such examples.

  Although the thickness after drying of an adhesive layer is not specifically limited, Usually, it is preferably 3-100 micrometers, More preferably, it is 5-50 micrometers.

  Examples of the film include polyolefin resin films such as polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer, polyester resin films such as polyethylene terephthalate and polybutylene terephthalate, and polyamides such as nylon 6 and nylon 6,6. Although resin films, such as a resin film, an acrylic resin film, a polystyrene resin film, a polyvinyl chloride resin film, and a polycarbonate resin film, are mentioned, this invention is not limited only to this illustration.

  The thickness of the film cannot be determined unconditionally because it varies depending on the type and use of the film, but is usually preferably about 5 to 200 μm, more preferably about 10 to 125 μm, and still more preferably about 20 to 100 μm. It is.

  In addition, from the viewpoint of improving the release property between the pressure-sensitive adhesive layer and the film, a release agent such as a silicone release agent, a fluorine release agent, or a fatty acid amide release agent is provided on the surface of the film. It may be applied and may be subjected to surface treatment such as corona treatment, plasma treatment, or ultraviolet treatment.

  Moreover, the separator for protecting the surface of an adhesive layer may be formed in the surface of the formed adhesive layer as needed.

  Examples of separators include polyolefin resin films such as polyethylene films and polypropylene films, polyvinyl chloride resin films, polyethylene terephthalate films, polyester resin films such as polybutylene terephthalate films, polyurethane resin films, and ethylene-vinyl acetate copolymers. A resin film such as a film made of; paper, etc. can be mentioned, but the present invention is not limited to such illustration. Although the thickness of a separator is not specifically limited, Usually, it is preferable that it is about 5-200 micrometers, and it is more preferable that it is about 10-100 micrometers. Moreover, a release agent may be applied to the separator as necessary, and a treatment such as an antifouling treatment or an antistatic treatment may be applied.

  Since the pressure-sensitive adhesive film of the present invention obtained as described above has a pressure-sensitive adhesive layer formed from the acryloyloxy group-containing compound pressure-sensitive adhesive of the present invention, it is excellent in pressure-sensitive adhesiveness.

  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 flask, 100 g of an acryloyloxy group-containing compound represented by the formula (I) and 10 g of 2-hydroxy-2-methylpropiophenone [manufactured by BASF Japan Ltd., trade name: DAROCUR1173] as a polymerization initiator are placed. The monomer component was obtained by mixing so as to obtain a uniform composition.

After the monomer component obtained above was applied on a polyester plate with a bar coater No. 10 so that the thickness was about 20 μm, a rectangular polyester film (length: 300 mm, width: on the formed coating film) 24 mm, thickness: 125 μm) was placed in close contact with the coating film, and ultraviolet rays were applied at an exposure amount of 6000 mJ / cm ² using an ultraviolet exposure machine (product name: UB031-5BM, manufactured by Eye Graphics Co., Ltd.). By irradiation, a monomer component was polymerized, and a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface was obtained. In addition, when the glass transition temperature of the polymer obtained by superposing | polymerizing the said monomer component was measured separately, the said glass transition temperature was -37 degreeC.

  Next, the pressure-sensitive adhesive sheet obtained as described above was allowed to stand in the atmosphere at room temperature (about 25 ° C.) for 24 hours, and then was subjected to a tensile tester [( Using a Shimadzu Corporation product name: Autograph AG-I], the polyester film was peeled 180 ° at a peeling speed of 300 mm / min, and the peel strength when the polyester film peeled was measured. As a result, the peel strength was 88 mN / 24 mm.

Comparative Example 1
In Example 1, a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface in the same manner as in Example 1 except that 100 g of n-octyl acrylate was used instead of 100 g of the acryloyloxy group-containing compound represented by the formula (I). The peel strength was measured in the same manner as in Example 1. As a result, the peel strength was 70 mN / 24 mm. In addition, when the glass transition temperature of the homopolymer of n-octyl acrylate was separately measured, the glass transition temperature was -71 ° C.

Comparative Example 2
In Example 1, except that 100 g of isodecyl acrylate was used instead of 100 g of the acryloyloxy group-containing compound represented by the formula (I), a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface was obtained in the same manner as in Example 1. The peel strength was measured in the same manner as in Example 1, and the peel strength was 61 mN / 24 mm. In addition, when the glass transition temperature of the homopolymer of isodecyl acrylate was separately measured, the glass transition temperature was -62 ° C.

Comparative Example 3
In Example 1, a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface was prepared in the same manner as in Example 1 except that 100 g of lauryl acrylate was used instead of 100 g of the acryloyloxy group-containing compound represented by the formula (I). When the peel strength was measured in the same manner as in Example 1, the peel strength was 51 mN / 24 mm. In addition, when the glass transition temperature of the homopolymer of lauryl acrylate was separately measured, the glass transition temperature was −23 ° C.

Comparative Example 4
In Example 1, except that 100 g of isononyl acrylate was used instead of 100 g of the acryloyloxy group-containing compound represented by the formula (I), a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface was obtained in the same manner as in Example 1. When the peel strength was measured in the same manner as in Example 1, the peel strength was 43 mN / 24 mm. In addition, when the glass transition temperature of the homopolymer of isononyl acrylate was separately measured, the glass transition temperature was -71 ° C.

Comparative Example 5
In Example 1, a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface in the same manner as in Example 1 except that 100 g of 2-ethylhexyl acrylate was used instead of 100 g of the acryloyloxy group-containing compound represented by the formula (I) Was prepared and the peel strength was measured in the same manner as in Example 1. The peel strength was 47 mN / 24 mm. In addition, when the glass transition temperature of the homopolymer of 2-ethylhexyl acrylate was separately measured, the glass transition temperature was -70 ° C.

Comparative Example 6
In Example 1, except that 100 g of isooctyl acrylate was used instead of 100 g of the acryloyloxy group-containing compound represented by the formula (I), a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface was obtained in the same manner as in Example 1. The peel strength was measured in the same manner as in Example 1, and the peel strength was 37 mN / 24 mm. In addition, when the glass transition temperature of the homopolymer of isooctyl acrylate was separately measured, the glass transition temperature was -70 ° C.

From the results of Example 1 and Comparative Examples 1 to 6, the pressure-sensitive adhesive sheet obtained in Example 1 is
Since the acryloyloxy group-containing compound represented by the formula (I) is used as the monomer component, it can be seen that the peel strength is remarkably superior to the pressure-sensitive adhesive sheets obtained in Comparative Examples 1 to 6. .

Example 2
Into a 500 mL flask, 30 g of an acryloyloxy group-containing compound represented by the formula (I) and 70 g of methyl ethyl ketone were placed, and the inside of the flask was sufficiently replaced with nitrogen gas, and then 1.5 g of azoisobutyronitrile was placed in the flask. Then, a thermal polymerization reaction was performed at 50 ° C. for 2 days in a nitrogen gas atmosphere. The obtained polymerization reaction solution was used as an adhesive.

  Next, the pressure-sensitive adhesive obtained above was applied to a polyester plate with a bar coater No. 10 so that the thickness after drying was about 10 μm, and then dried under reduced pressure at a temperature of 55 ° C. for 2 hours. The solvent (methyl ethyl ketone) contained in the formed pressure-sensitive adhesive layer was volatilized and removed. Thereafter, a rectangular polyester film (length: 300 mm, width: 24 mm, thickness: 125 μm) is placed on and closely adhered to the formed coating film to obtain a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface. It was. The weight average molecular weight of the polymer contained in the pressure-sensitive adhesive layer was 33000, and the glass transition temperature of the polymer was −37 ° C.

  When the peel strength was measured in the same manner as in Example 1 using the pressure-sensitive adhesive sheet obtained above, the peel strength was 169 mN / 24 mm.

Comparative Example 7
In Example 2, a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface in the same manner as in Example 2 except that 30 g of n-butyl acrylate was used instead of 30 g of the acryloyloxy group-containing compound represented by the formula (I) Was prepared and the peel strength was measured in the same manner as in Example 1. The peel strength was 48 mN / 24 mm. In addition, the weight average molecular weight of the polymer contained in the pressure-sensitive adhesive layer was 40000, and the glass transition temperature of the polymer was -54 ° C.

Comparative Example 8
In Example 2, except that 30 g of n-octyl acrylate was used instead of 30 g of the acryloyloxy group-containing compound represented by the formula (I), a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface in the same manner as in Example 2. Was prepared and the peel strength was measured in the same manner as in Example 1. The peel strength was 38 mN / 24 mm. In addition, the weight average molecular weight of the polymer contained in the pressure-sensitive adhesive layer was 42000, and the glass transition temperature of the polymer was -71 ° C.

Comparative Example 9
In Example 2, a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface was prepared in the same manner as in Example 2 except that 30 g of isodecyl acrylate was used instead of 30 g of the acryloyloxy group-containing compound represented by the formula (I). When the peel strength was measured in the same manner as in Example 1, the peel strength was 63 mN / 24 mm. The weight average molecular weight of the polymer contained in the pressure-sensitive adhesive layer was 28000, and the glass transition temperature of the polymer was −62 ° C.

Comparative Example 10
In Example 2, a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface was prepared in the same manner as in Example 2 except that 30 g of lauryl acrylate was used instead of 30 g of the acryloyloxy group-containing compound represented by the formula (I). When the peel strength was measured, the peel strength was 32 mN / 24 mm. In addition, the weight average molecular weight of the polymer contained in the adhesive layer was 37000, and the glass transition temperature of the polymer was −23 ° C.

Comparative Example 11
In Example 2, a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface was obtained in the same manner as in Example 2 except that 30 g of isononyl acrylate was used instead of 30 g of the acryloyloxy group-containing compound represented by the formula (I). When the peel strength was measured in the same manner as in Example 1, the peel strength was 59 mN / 24 mm. The weight average molecular weight of the polymer contained in the pressure-sensitive adhesive layer was 30000, and the glass transition temperature of the polymer was −71 ° C.

Comparative Example 12
In Example 2, a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface in the same manner as in Example 2 except that 30 g of 2-ethylhexyl acrylate was used instead of 30 g of the acryloyloxy group-containing compound represented by the formula (I) Was prepared and the peel strength was measured in the same manner as in Example 1. The peel strength was 74 mN / 24 mm. The weight average molecular weight of the polymer contained in the pressure-sensitive adhesive layer was 35000, and the glass transition temperature of the polymer was −70 ° C.

Comparative Example 13
In Example 2, a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface was obtained in the same manner as in Example 2 except that 30 g of isooctyl acrylate was used instead of 30 g of the acryloyloxy group-containing compound represented by the formula (I). The peel strength was measured in the same manner as in Example 1. As a result, the peel strength was 71 mN / 24 mm. In addition, the weight average molecular weight of the polymer contained in the pressure-sensitive adhesive layer was 40000, and the glass transition temperature of the polymer was -70 ° C.

  From the results of Example 2 and Comparative Examples 7 to 13, since the acryloyloxy group-containing compound represented by the formula (I) is used as the monomer component in the pressure-sensitive adhesive sheet obtained in Example 2, Comparative Example 7 It turns out that it is remarkably excellent in peeling strength compared with the adhesive sheet obtained by ~ 13.

Example 3
A monomer component was prepared by mixing 80 g of an acryloyloxy group-containing compound represented by the formula (I), 10 g of methyl methacrylate and 10 g of 2-hydroxyethyl methacrylate.

  Into a 500 mL flask, 30 g of the monomer component obtained above and 70 g of methyl ethyl ketone were placed, and after sufficiently replacing the inside of the flask with nitrogen gas, 1.5 g of azoisobutyronitrile was added to the flask, and nitrogen gas was added. A thermal polymerization reaction was performed in an atmosphere at 50 ° C. for 2 days. The obtained polymerization reaction solution was used as an adhesive. In addition, the weight average molecular weight of the polymer contained in the obtained polymerization reaction solution was 28000, and the glass transition temperature was 0 degreeC.

  Next, the pressure-sensitive adhesive obtained above was used as a bar coater no. 10 is applied on a polyester plate so that the thickness after drying is about 10 μm, and then dried under reduced pressure at a temperature of 55 ° C. for 2 hours, whereby the solvent (methyl ethyl ketone) contained in the formed adhesive layer is formed. ) Was stripped off. Thereafter, a rectangular polyester film (length: 300 mm, width: 24 mm, thickness: 125 μm) is placed on and closely adhered to the formed coating film to obtain a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface. It was.

  The peel strength of the pressure-sensitive adhesive sheet obtained above was measured in the same manner as in Example 1. As a result, the peel strength was 168 mN / 24 mm.

Comparative Example 14
In Example 3, a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface in the same manner as in Example 3 except that 30 g of n-butyl acrylate was used instead of 30 g of the acryloyloxy group-containing compound represented by the formula (I). Was prepared and the peel strength was measured in the same manner as in Example 1. The peel strength was 126 mN / 24 mm. In addition, the weight average molecular weight of the polymer contained in the obtained polymerization reaction solution was 33000, and the glass transition temperature of the polymer was −24 ° C.

Comparative Example 15
In Example 3, except that 30 g of n-octyl acrylate was used instead of 30 g of the acryloyloxy group-containing compound represented by the formula (I), a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface in the same manner as Example 3 When the peel strength when the polyester film was peeled was measured in the same manner as in Example 1, the peel strength was 82 mN / 24 mm. In addition, the weight average molecular weight of the polymer contained in the obtained polymerization reaction solution was 37000, and the glass transition temperature of the polymer was −26 ° C.

Comparative Example 16
In Example 3, except that 30 g of isodecyl acrylate was used instead of 30 g of the acryloyloxy group-containing compound represented by the formula (I), a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface was obtained in the same manner as in Example 3. When the peel strength when the polyester film was prepared and peeled was measured in the same manner as in Example 1, the peel strength was 91 mN / 24 mm. In addition, the weight average molecular weight of the polymer contained in the obtained polymerization reaction solution was 23000, and the glass transition temperature of the polymer was −16 ° C.

Comparative Example 17
In Example 3, a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface was prepared in the same manner as in Example 3 except that 30 g of lauryl acrylate was used instead of 30 g of the acryloyloxy group-containing compound represented by the formula (I). When the peel strength when the polyester film was peeled was measured in the same manner as in Example 1, the peel strength was 26 mN / 24 mm. In addition, the weight average molecular weight of the polymer contained in the obtained polymerization reaction solution was 32000, and the glass transition temperature of the polymer was 14 ° C.

Comparative Example 18
In Example 3, except that 30 g of isononyl acrylate was used instead of 30 g of the acryloyloxy group-containing compound represented by the formula (I), a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface was obtained in the same manner as in Example 3. The peel strength was measured in the same manner as in Example 1, and the peel strength was 99 mN / 24 mm. In addition, the weight average molecular weight of the polymer contained in the obtained polymerization reaction solution was 25000, and the glass transition temperature of the polymer was −24 ° C.

Comparative Example 19
In Example 3, except that 30 g of 2-ethylhexyl acrylate was used instead of 30 g of the acryloyloxy group-containing compound represented by the formula (I), a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface in the same manner as Example 3 Was prepared and the peel strength was measured in the same manner as in Example 1. The peel strength was 77 mN / 24 mm. In addition, the weight average molecular weight of the polymer contained in the obtained polymerization reaction solution was 30000, and the glass transition temperature of the polymer was −26 ° C.

Comparative Example 20
In Example 3, except that 30 g of isooctyl acrylate was used instead of 30 g of the acryloyloxy group-containing compound represented by the formula (I), a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer on one surface was obtained in the same manner as in Example 3. When the peel strength was measured in the same manner as in Example 1, the peel strength was 110 mN / 24 mm. In addition, the weight average molecular weight of the polymer contained in the obtained polymerization reaction solution was 35000, and the glass transition temperature of the polymer was -70 ° C.

  From the results of Example 3 and Comparative Examples 14 to 20, the pressure-sensitive adhesive sheet obtained in Example 3 uses the acryloyloxy group-containing compound represented by the formula (I) as the monomer component. It can be seen that the peel strength is remarkably excellent as compared with the pressure-sensitive adhesive sheet obtained in -20.

  From the above results, the pressure-sensitive adhesive film using the pressure-sensitive adhesive obtained in each example uses the acryloyloxy group-containing compound represented by the formula (I) as the monomer component. It can be seen that the adhesiveness is remarkably excellent as compared with the obtained adhesive film.

  The pressure-sensitive adhesive film using the acryloyloxy group-containing compound-based pressure-sensitive adhesive of the present invention is, for example, a polarizing plate, a wave plate, a retardation plate, an optical compensation film, a reflection sheet, a brightness enhancement film, etc. used for liquid crystal displays. It is expected to be used as a surface protective film used for protecting the optical member surface.

Claims (3)

Formula (I):
An acryloyloxy group-containing compound-based pressure-sensitive adhesive comprising a polymer obtained by polymerizing a monomer component containing an acryloyloxy group-containing compound represented by the formula: An acryloyloxy group-containing compound-based pressure-sensitive adhesive having a content of 70% by mass or more .   Formula (I):
An acryloyloxy group-containing compound-based pressure-sensitive adhesive comprising a polymer obtained by polymerizing a monomer component containing an acryloyloxy group-containing compound represented by the formula: 50 to 100% by mass, 0 to 30% by mass of an alkyl (meth) acrylate having an alkyl group having 1 to 4 carbon atoms and 0 to 30% by mass of a hydroxyalkyl (meth) acrylate having a hydroxyalkyl group having 2 to 8 carbon atoms An acryloyloxy group-containing compound-based pressure-sensitive adhesive. The adhesive film which has the adhesive layer formed from the acryloyloxy group containing compound adhesive of Claim 1 or 2 on the single side | surface or both surfaces of a film.