JP7077673B2 - Active energy ray-curable pressure-sensitive adhesive composition - Google Patents

Description

INDUSTRIAL APPLICABILITY The present invention relates to an active energy ray-curable pressure-sensitive adhesive composition and can be used for various uses such as pressure-sensitive adhesive labels, pressure-sensitive adhesive tapes and special pressure-sensitive adhesive films, and can be particularly preferably used for re-peeling applications. It belongs to these technical fields.
In the present specification, acryloyl group and / or methacrylic acid group is referred to as (meth) acryloyl group, acrylate and / or methacrylate is referred to as (meth) acrylate, and acrylic acid and / or methacrylic acid is referred to as (meth) acrylic acid. It is expressed as.
Further, as used herein, the term "monofunctional" means a compound having one ethylenically unsaturated group such as a (meth) acryloyl group.

Adhesives are used in various labels, tapes, etc., taking advantage of their ability to be peeled off after being applied. Among them, a pressure-sensitive adhesive having a weak adhesive force is also called a re-peelable pressure-sensitive adhesive, and has a function of being easily peeled off from an adherend after a certain period of time after being applied. It is widely used as a masking tape and a protective film in the above applications.
As a more specific use of the removable adhesive, there is a removable adhesive processed paper in which the facing surface of a folding sheet on which general information, confidential information, etc. are printed on the superposed surface is releasably bonded. In recent years, it has been widely used in various notifications from the viewpoint of automating the creation of notifications and protecting personal information.
The removable pressure-sensitive adhesive processed paper is provided with a pressure-sensitive removable pressure-sensitive adhesive layer at a predetermined portion of the overlapped surfaces so that the overlapped surfaces adhere to each other. By bringing the removable pressure-sensitive adhesive layers into contact with each other and applying a strong pressure, they adhere to each other during normal handling, and can be re-peeled by peeling off.

Adhesives are roughly classified into solvent-based adhesives, emulsion-type adhesives, solvent-free adhesives, etc. depending on their form, but they are a type of solvent-free adhesives because they do not require a solvent and can reduce energy costs. The active energy ray-curable adhesive is attracting attention.
Unlike solvent-type pressure-sensitive adhesives and emulsion-type pressure-sensitive adhesives, active energy ray-curable pressure-sensitive adhesives do not require a step of removing a solvent such as a solvent or water when forming the pressure-sensitive adhesive layer, so that energy costs can be reduced. In addition, it is an environment-friendly adhesive because it does not require a solvent. For these reasons, it has been used in various fields such as image display devices, home appliances, information equipment, automobile interior / exterior materials, building materials, and labels in recent years. Has been done.

Conventionally, an active energy ray-curable pressure-sensitive adhesive containing a (meth) acrylic polymer as a main component is known. The pressure-sensitive adhesive is a composition containing an organic solvent in order for the (meth) acrylic polymer to use an organic solvent at the time of synthesis or to reduce the viscosity, and the composition is applied to a base material to apply a pressure-sensitive adhesive layer. It is necessary to remove the organic solvent by drying when forming.
However, since it was difficult to eliminate the residual organic solvent in the pressure-sensitive adhesive layer, which is a cured film, there were problems in terms of odor and safety when using it as a pressure-sensitive adhesive tape. Things are sought after.

The solvent-free composition comprises a dry resin (meth) acrylic polymer, an unsaturated monomer having one ethylenically unsaturated group (hereinafter referred to as “monofunctional monomer”), and a polyfunctional (meth) acrylate. The composition is disclosed (Patent Document 1).
However, even if the coating film is laminated with a release film and irradiated with ultraviolet rays under air blocking, the curability is lowered due to the influence of polymerization inhibition by dissolved oxygen in the coating film, and the adhesive layer of the cured film is covered. Since unreacted monofunctional monomer remains, there are problems in terms of odor and safety when used as an adhesive tape.

Further, a solvent-free composition containing an acrylic oligomer such as urethane (meth) acrylate as a main component is also known.
Patent Document 2 discloses a composition comprising a urethane (meth) acrylate and a compound having one (meth) acryloyl group (hereinafter referred to as "monofunctional (meth) acrylate"). By using a monofunctional (meth) acrylate, it is easy to make it solvent-free and low viscosity, and it is easy to adjust the glass transition temperature of the cured film, but the curability is reduced due to the effect of polymerization inhibition by dissolved oxygen in the coating film. Since unreacted monofunctional (meth) acrylate remains in the pressure-sensitive adhesive layer, there are problems in terms of odor and safety when used as a pressure-sensitive adhesive tape.

Patent Document 3 discloses a composition composed of a hydrogenated polybutadiene-based urethane (meth) acrylate and a (meth) acrylate, and in Examples 9 and 10, it remains as an unreacted substance in the pressure-sensitive adhesive layer. Composition containing 20% by weight of tripropylene glycol diacrylate (hereinafter referred to as "TPGDA") or 1,9-nonanediol diacrylate (hereinafter referred to as "NDDA") which is a bifunctional acrylate without containing a functional (meth) acrylate. The thing is disclosed.
However, since the content of TPGDA or NDDA is as low as 20% by weight, the viscosity of the composition is high and the coatability is insufficient. On the other hand, when the content of TPGDA or NDDA is increased, the coatability can be improved by reducing the viscosity of the composition, but there is a problem that the tack is lost and the adherend cannot be attached.

JP-A-2007-217674 Japanese Unexamined Patent Publication No. 2014-5368 Japanese Patent Application Laid-Open No. 2003-155455

The present inventors have diligently found an active energy ray-curable pressure-sensitive adhesive composition in which the composition has a low odor, is excellent in curability even under low-energy irradiation conditions, and the obtained cured film is excellent in adhesive strength and removability. It was examined.

In order to solve the above problems, the present inventors have prepared an active energy ray-curable pressure-sensitive adhesive composition containing a polyfunctional unsaturated compound, an aromatic monofunctional unsaturated compound and a high molecular weight photopolymerization initiator to have a low odor. Therefore, they have found that the cured film is excellent in curability even under low energy irradiation conditions, and the obtained cured film is excellent in adhesive strength and removability, and completed the present invention.
Hereinafter, the present invention will be described in detail.

According to the composition of the present invention, it has a low odor and is excellent in curability even under low energy irradiation conditions, and the obtained cured film can be excellent in adhesive strength and removability.

The present invention contains the following components (A), (B) and (C) as essential components , and does not contain a compound having a mercapto group in the molecule. The active energy ray-curable pressure-sensitive adhesive composition (hereinafter, simply "composition"). Sometimes called "things").
-Component (A): A compound having two or more ethylenically unsaturated groups including urethane (meth) acrylate -Component (B): having an aromatic group and one ethylenically unsaturated group , and oxy Compounds with alkylene units -Component (C): Photopolymerization initiator with a molecular weight of 300 or more excluding (C-1) acylphosphine oxide-based compound and / and light containing (C-2) acylphosphine oxide-based compound as an essential component Polymerization initiator

Hereinafter, the components (A), (B) and (C), the active energy ray-curable pressure-sensitive adhesive composition and their uses will be described.

1. 1. Component (A ) Component (A) is a compound having two or more ethylenically unsaturated groups.
By including the component (A), the cured film of the composition has excellent removability.
Examples of the ethylenically unsaturated group in the component (A) include (meth) acryloyl group, (meth) acrylamide group, vinyl group and (meth) allyl group, and (meth) acryloyl group is preferable.
In the following, "○ functional" means a compound having ○ ethylenically unsaturated groups, and "polyfunctional" means a compound having two or more ethylenically unsaturated groups.

As the component (A), polyfunctional (meth) acrylate is preferable.
Specific examples of the bifunctional (meth) acrylate include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexanediol di (meth) acrylate and nonanediol di (meth). Alkylene glycol di (meth) acrylates such as acrylates;
Polyalkylene glycol di (meth) acrylates such as polyethylene glycol di (meth) acrylates, polypropylene glycol di (meth) acrylates, and polytetramethylene glycol di (meth) acrylates; and di (meth) alkylene oxide adducts of bisphenol A. Examples thereof include di (meth) acrylates of bisphenol compounds such as acrylates and di (meth) acrylates of alkylene oxide adducts of bisphenol F.

As the bifunctional (meth) acrylate, an oligomer may be used, and examples thereof include urethane (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, and polyether (meth) acrylate.
Among these compounds, urethane (meth) acrylate is preferable, and will be described in detail later.

Epoxy (meth) acrylate is a reaction product of epoxy resin and (meth) acrylic acid.
Examples of the epoxy resin include bisphenol type epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin, and novolak type epoxy resins. Examples of the bisphenol A type epoxy resin include Epicoat 827 (trade name, the same applies hereinafter) manufactured by Japan Epoxy Resin Co., Ltd., Epicoat 828, Epicoat 1001, Epicoat 1004 and the like, and examples of the bisphenol F type epoxy resin include Epicoat 806 and Epicoat 4004P. And so on. Examples of the novolak type epoxy resin include Epicoat 152 and Epicoat 154.

Polyester (meth) acrylate is a reaction product of polyester polyol and (meth) acrylic acid.
The polyester polyol is obtained by reacting a polyhydric alcohol with a polybasic acid.
Examples of the polyhydric alcohol include neopentyl glycol, ethylene glycol, propylene glycol, 1,6-hexanediol, trimethylolpropane, pentaerythritol, tricyclodecanedimethylol and bis- [hydroxymethyl] -cyclohexane.
Examples of the polybasic acid include succinic acid, phthalic acid, hexahydrophthalic anhydride, terephthalic acid, adipic acid, azelaic acid, tetrahydrophthalic anhydride and the like.

Examples of the trifunctional or higher (meth) acrylate compound include various compounds as long as they are compounds having three or more (meth) acryloyl groups, and examples thereof include glycerintri (meth) acrylate and trimethylolpropane tri (meth) acrylate. , Diglycerin tri or tetra (meth) acrylate, pentaerythritol tri or tetra (meth) acrylate, dimethylolpropane tri or tetra (meth) acrylate and dipentaerythritol tri, tetra, penta or hexa (meth) acrylate. Polypoly (meth) acrylates such as;
Tri or tetra (meth) acrylate of pentaerythritol alkylene oxide adduct, tri or tetra (meth) acrylate of ditrimethylol propanealkylene oxide adduct, tri, tetra, penta or hexa (meth) acrylate of dipentaerythritol alkylene oxide adduct Poly (meth) acrylates of polyol alkylene oxide adducts such as, and tri (meth) acrylates of isocyanuric acid alkylene oxide adducts can be mentioned.

Examples of the alkylene oxide adduct in the compounds exemplified above include ethylene oxide adducts, propylene oxide adducts, ethylene oxide and propylene oxide adducts, and the like.

As the component (A), only one kind may be used, or two or more kinds may be used in combination.
The glass transition temperature (hereinafter referred to as “Tg”) of the homopolymer of the component (A) is preferably in the range of −80 to 60 ° C., and more preferably in the range of −60 to 40 ° C.
In the present invention, Tg means a value measured at a heating rate of 10 ° C./min using a differential scanning calorimeter (DSC), and is at the glass transition temperature midpoint (Tmg) in the ΔT-temperature curve. Means a value.
As the component (A), urethane (meth) acrylate [hereinafter referred to as "component (A-1)"] is preferable because it can improve the adhesive strength.
Hereinafter, the component (A-1) will be described in detail.

1-1. (A-1) Ingredient
Examples of the urethane (meth) acrylate of the component (A-1) include a polyol, an organic polyisocyanate and a reaction product of a hydroxyl group-containing (meth) acrylate, and a reaction product of an organic polyisocyanate and a hydroxyl group-containing (meth) acrylate.

As the polyol in the component (A-1), diol is preferable.
As the diol, a low molecular weight diol, a diol having a polyene skeleton, a diol having a polyester skeleton, a diol having a polyether skeleton, and a diol having a polycarbonate skeleton are preferable.
Examples of the low molecular weight diol include ethylene glycol, propylene glycol, cyclohexanedimethanol, neopentyl glycol, 3-methyl-1,5-pentanediol and 1,6-hexanediol.
Examples of the diol having a polyene skeleton include a diol having a polybutadiene skeleton, a diol having a polyisoprene skeleton, a diol having a hydrogenated polybutadiene skeleton, and a diol having a hydrogenated polyisoprene skeleton.
Examples of the diol having a polyester skeleton include an esterification reaction product of a diol component such as the low molecular weight diol or polycaprolactone diol and an acid component such as a dicarboxylic acid or an anhydride thereof. Examples of the dicarboxylic acid or its anhydride include adipic acid, succinic acid, phthalic acid, tetrahydraphthalic acid, hexahydrophthalic acid, terephthalic acid and the like, and their anhydrides and the like.
Examples of the polyether diol include polyethylene glycol, polypropylene glycol, polyetramethylene glycol and the like.
Examples of the polycarbonate diol include a reaction product of the low molecular weight diol and / or bisphenol such as bisphenol A and a carbonic acid dialkyl ester such as ethylene carbonate and carbonic acid dibutyl ester.
These diols may be used alone or in combination of two or more.

As the organic polyisocyanate, an organic diisocyanate is preferable.
Specific examples of the organic diisocyanate include hexamethylene diisocyanate (hereinafter referred to as “HDI”), lysine methyl ester diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, aliphatic diisocyanate such as dimerate diisocyanate, and isophorone diisocyanate (hereinafter referred to as “isophorone diisocyanate”). "IPDI"), 4,4'-methylenebis (cyclohexyl isocyanate) (hereinafter referred to as "H12MDI") and alicyclic diisocyanates such as ω, ω'-diisocyanate dimethylcyclohexane, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane- Aromatic diisocyanates such as 4,4'-diisocyanate can be mentioned.
Specific examples of the organic polyisocyanate having three or more isocyanate groups include hexamethylene diisocyanate trimer and isophorone diisocyanate trimer.
These diisocyanate compounds may be used alone or in combination of two or more.

Examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate and hydroxyhexyl (meth) acrylate. Hydroxyalkyl (meth) acrylates such as hydroxyoctyl (meth) acrylates [hereinafter referred to as "hydroxyl-containing monofunctional (meth) acrylates"], and trimethylolpropane mono or di (meth) acrylates, pentaerythritol mono, di or Tri (meth) acrylates, ditrimethylolpropane mono, di or tri (meth) acrylates and dipentaerythritol mono, di, tri, tetra or penta (meth) acrylates and other hydroxyl groups and two or more (meth) acryloyl groups. [Hereinafter referred to as “hydroxyl-containing polyfunctional (meth) acrylate”] and the like.
Among the above-mentioned compounds, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are excellent in the curability of the composition and the adhesive strength of the cured film. preferable.

As the component (A-1), a compound called urethane adduct, which is a reaction product of an organic polyisocyanate and a hydroxyl group-containing (meth) acrylate, can also be used.
Examples of the organic polyisocyanate and the hydroxyl group-containing (meth) acrylate in the urethane adduct include the above-mentioned compounds.
Among the above-mentioned compounds, a combination of an organic diisocyanate and a hydroxyl group-containing monofunctional (meth) acrylate is preferable, and more specifically, as an organic diisocyanate, in terms of lowering the viscosity of the composition and excellent adhesive strength of the cured film. HDI, IPDI, H12MDI and tolylene diisocyanate are preferable, and as the hydroxyl group-containing (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are preferable. ..

In the urethane adduct, urethane (meth) acrylate obtained by using a hydroxyl group-containing polyfunctional (meth) acrylate as the hydroxyl group-containing (meth) acrylate can also be used.
As the hydroxyl group-containing polyfunctional (meth) acrylate in the urethane adduct, various compounds can be used, specifically, trimethylolpropane di (meth) acrylate, pentaerythritol di or tri (meth) acrylate, and trimethylolpropane. Di or tri (meth) acrylates and di, trimethylolpropane or penta (meth) acrylates of dipentaerythritol can be mentioned.
Preferred examples of the urethane adduct include an addition reaction product of HDI and pentaerythritol tri (meth) acrylate, an addition reaction product of IPDI and pentaerythritol tri (meth) acrylate, and the like.

Another preferred compound of urethane adduct includes a reaction product of an organic polyisocyanate having three or more isocyanate groups and a hydroxyl group-containing monofunctional (meth) acrylate.
Examples of the hydroxyl group-containing monofunctional (meth) acrylate in the compound include compounds similar to those described above.
Examples of the organic polyisocyanate having three or more isocyanate groups include the hexamethylene diisocyanate trimer and the isophorone diisocyanate trimer described above.

The component (A-1) may be manufactured according to a conventional method.
As the component (A-1), a compound obtained by reacting a polyol with an organic polyisocyanate to produce an isocyanate group-containing compound and reacting this with a hydroxyl group-containing (meth) acrylate (hereinafter referred to as “compound A1”), and Examples thereof include a compound obtained by simultaneously reacting a polyol, an organic polyisocyanate and a hydroxyl group-containing (meth) acrylate (hereinafter referred to as “compound A2”), and the compound A1 is preferable because the molecular weight can be easily controlled.
As a method for producing the compound A1, for example, in the presence of a urethanization catalyst such as dibutyltin dilaurate, the polyol and the organic polyisocyanate to be used are heated and stirred for an addition reaction, and further, a hydroxyl group-containing (meth) acrylate is added, and the mixture is heated and stirred for addition. Examples thereof include a method of reacting, and in the case of producing compound A2, a method of simultaneously adding a polyol, an organic polyisocyanate and a hydroxyl group-containing (meth) acrylate in the presence of the same catalyst as described above and heating and stirring the compound A2 can be mentioned. Be done.
Examples of the method for producing the urethane adduct include a method of heating and stirring an organic polyisocyanate and a hydroxyl group-containing (meth) acrylate in the presence of the same catalyst as described above.

As the component (A-1), only one kind may be used, or two or more kinds may be used in combination.
The weight average molecular weight (hereinafter referred to as “Mw”) of the component (A-1) is preferably 1,000 to 60,000, more preferably 3,000 to 20,000.
Mw in the present invention means a polystyrene-equivalent number average molecular weight measured by gel permeation chromatography (GPC).
The Tg of the homopolymer of the component (A-1) is preferably in the range of -80 to 60 ° C, more preferably in the range of -60 to 40 ° C.

2. 2. Component (B ) Component (B) is a compound having an aromatic group and one ethylenically unsaturated group.
By including the component (B), the cured film of the composition has excellent adhesive strength and removability.
As the component (B), various compounds can be used as long as they are compounds having an aromatic group and one ethylenically unsaturated group, and monofunctional (meth) acrylate is preferable.
Examples of the monofunctional (meth) acrylate include benzyl (meth) acrylate, (meth) acrylate of a phenol alkylene oxide adduct, (meth) acrylate of a p-cumylphenol alkylene oxide adduct, and o-phenylphenol alkylene oxide adduct. Examples thereof include (meth) acrylate and (meth) acrylate of a nonylphenol alkylene oxide adduct.
Examples of the alkylene oxide adduct mentioned above include ethylene oxide adducts, propylene oxide adducts, ethylene oxide and propylene oxide adducts, and the like.

As the component (B), a compound having an oxyalkylene unit is preferable because it has excellent adhesive strength.
Specific examples of the compound include (meth) acrylate of a phenol alkylene oxide adduct, (meth) acrylate of a p-cumylphenol alkylene oxide adduct, (meth) acrylate of an o-phenylphenol alkylene adduct adduct, and nonylphenol. Examples thereof include (meth) acrylate as an alkylene oxide adduct.
The number of repetitions of the oxyalkylene unit of the compound is preferably 1 or more, and more preferably 1 to 5 repetitions.
Further, as the component (B), a compound having an alkyl group and an oxyalkylene unit is more preferable in that the surface tension is low and the composition is excellent in coatability.
As the alkyl group, an alkyl group having 1 to 12 carbon atoms is preferable, and a long chain alkyl group having 4 to 12 carbon atoms is more preferable.
Furthermore, a compound having a long-chain alkyl group and an oxyalkylene unit having one or more repetitions is more preferable in that the composition is excellent in coatability. Specific examples of the compound include (meth) acrylate of a nonylphenol alkylene oxide adduct.

The Tg of the homopolymer of the component (B) is preferably in the range of −50 to 40 ° C, more preferably in the range of −30 to 20 ° C.

As for the content ratio of the components (A) and (B), a compound having one ethylenically unsaturated group other than the component (B) described later in 100% by weight of the total amount of the components (A) and (B). When [hereinafter referred to as "(D) component"] is blended, 5 to 50% by weight of the component (A) and ( The B) component is preferably contained in an amount of 50 to 95% by weight, more preferably the component (A) is contained in an amount of 10 to 30% by weight, and the component (B) is contained in an amount of 70 to 90% by weight.
By setting the content ratio of the components (A) and (B) to the above range, it is preferable in that the coatability of the composition and the adhesive strength of the cured film can be improved.
In the present invention, the curable component is a component that is cured by active energy rays, and means the component (A) and the component (B). When the component (D) described later is blended, the component (A) is used. It means a component, a component (B) and a component (D).

3. 3. (C) component The (C) component is a photopolymerization initiator having a molecular weight of 300 or more excluding the (C-1) acylphosphine oxide compound [hereinafter referred to as “(C-1) component”] or / and (C-1). ) An acylphosphine oxide-based compound [hereinafter referred to as "(C-2) component"] is a photopolymerization initiator containing an essential component.
In the present invention, by using the component (C), the curability of the composition is excellent, and the low odor property of the obtained cured film is excellent. Further, the component (C-1) is preferable in that the cured film has excellent light stability and less coloring.

As the component (C-1), the α-hydroxyketone compound is more preferable in that it is excellent in compatibility with the components (A) and (B) in addition to the above-mentioned excellent performance.
Specific examples of the α-hydroxyketone-based compound include oligomers and polymers of α-hydroxyketone, and examples thereof include compounds represented by the following formula (1).

In formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents an alkyl group, and n represents a number of 2 to 5. In addition, n means the average number of repetitions of the said unit.
As the alkyl group, R ² is preferably a lower alkyl group such as a methyl group, an ethyl group and a propyl group.

Specific examples of the compound represented by the formula (1) include oligo (2-hydroxy-2-methyl-1- (4- (1-methylvinyl) phenyl) propanone and the like.
The compound is commercially available, and examples thereof include ESACURE KIP 150 (manufactured by IGM Resins) and ESACURE ONE (manufactured by IGM Resins).
ESACURE KIP 150 and ESACURE ONE are compounds represented by the above formula (1), where R ¹ is a hydrogen atom or a methyl group, R ² is a methyl group, n is a number of 2 to 3, and [(204.3 × n + 16). .0) or (204.3 × n + 30.1)] is a compound having a molecular weight.
ESACURE ONE contains the same components as ESACURE KIP 150, but is a purified and high-purity product.

Examples of α-hydroxyketone compounds other than the above include 2-hydroxy-1- {4- [4- (2-hydroxy-2-methylpropionyl) phenoxy] phenyl} -2-methylpropan-1-one (commercially available product). Examples include ESACURE KIP-160 manufactured by IGM Resins. Hereinafter, parentheses indicate the same meaning) and (2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-). Propionyl) -benzyl] -phenyl} -2-methylpropane-1-one (Irgacure 127 manufactured by BASF) and the like can be mentioned.

Examples of the compound other than the α-hydroxyketone compound include 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester, oxyphenylacetic acid and the like.
The compound is commercially available, and Irgacure 754 (manufactured by BASF) is known. Irgacure 754 is a mixture of oxyphenylacetic acid, 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester and oxyphenylacetic acid, 2- (2-hydroxyethoxy) ethyl ester.
In addition, SPEEDCURE 7005 (molecular weight 1200 or more, manufactured by Rambuson Japan), which is an oligomer-type benzophenone-based photopolymerization initiator, oligomer-type thioxanthone-based photopolymerization initiator, etc. (molecular weight 1500 or more, manufactured by Rambuson Japan), ( 1- [4- (4-Benzoylphenylsulfanyl) phenyl] -2-methyl-2- (4-methylphenylsulfonyl) propan-1-one (ESACURE 1001M manufactured by IGM Resins), 2-benzyl-2-dimethylamino -1- (4-morpholinophenyl) butanone-1 (Irgacure 369 manufactured by BASF) and 2-dimethylamino-2- (4-methylbenzyl) -1- (4-morpholin-4-yl-phenyl) Butanon-1 (Irgacure 379 manufactured by BASF) and the like can be mentioned.

Examples of the acylphosphine oxide-based compound of the component (C-2) include bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and bis (2,6-dimethoxy). Benzoyl) -2,4,4-trimethylpentylphosphine oxide and the like can be mentioned.

The component (C) contains the components (C-1) and (C-2) as essential components, but if necessary, a photopolymerization initiator other than the components (C-1) and (C-2) [ Hereinafter, "(C-3) component"] can be used in combination.
Specific examples of the component (C-3) include benzyldimethylketal, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1- [4- (2-hydroxyethoxy). ) Phenyl] -2-hydroxy-2-methyl-1-propane-1-one, 2-methyl-1- [4- (methylthio)] phenyl] -2-morpholinopropane-1-one, etc. with a molecular weight of 300 Less than acetophenone compounds;
Benzoin compounds such as benzoin, benzoin ethyl ether, benzoin isopropyl ether and benzoin isobutyl ether;
Benzophenone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, methyl-2-benzophenone, 4,4'-bis (dimethylamino) benzophenone, 4 , Benzophenone compounds such as 4'-bis (diethylamino) benzophenone and 4-methoxy-4'-dimethylaminobenzophenone;
Thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 1-chloro-4-propylthioxanthone, 3- [3,4-dimethyl-9-oxo-9H-thioxanthone-2-yl-oxy]- Examples thereof include thioxanthone compounds such as 2-hydroxypropyl-N, N, N-trimethylammonium chloride and fluorothioxanthone.
Examples of the compound other than the above include benzyl, ethyl (2,4,6-trimethylbenzoyl) phenylphosphinate, methyl phenylglycite, ethylanthraquinone, phenanthrenequinone, camphorquinone and the like.

When it is necessary to increase the thickness of the cured film, for example, when it is necessary to make it 50 μm or more, for the purpose of improving the curability inside the cured film, or when an ultraviolet absorber or a pigment is used in combination. For the purpose of improving the curability of the composition, it is preferable to use a plurality of kinds of compounds selected from a thioxanthone-based compound and an α-aminoalkylphenone-based compound in combination.
Preferred examples of the compound in this case include 2,4-diethylthioxanthone, isopropylthioxanthone, 1-chloro-4-propoxythioxanthone and the like as thioxanthone-based compounds, and α-aminoalkylphenone-based compounds as α-aminoalkylphenone-based compounds. , 2-Methyl-1- [4- (methylthio)] phenyl] -2-morpholinopropane-1-one and the like.

The content ratio of the component (C) is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the total amount of the curable component. By setting the proportion of the component (C) to 0.1 parts by weight or more, the active energy ray curability of the composition can be improved and the adhesion can be improved. The internal curability of the cured film can be improved, and the adhesion to the substrate can be improved.

4. Active Energy Ray Curable Adhesive Composition The present invention relates to an active energy ray curable pressure-sensitive adhesive composition containing the components (A), (B) and (C) as essential components.
Further, the composition of the present invention is preferably used as an active energy ray-curable pressure-sensitive adhesive composition for re-peeling because the composition is excellent in coatability and curability, and the cured film is excellent in adhesive strength and re-peelability. be able to.
The peel strength when used for re-peeling is 23 ° C, 50% when the cured film of the composition has a film thickness of 40 μm, a polyethylene terephthalate film is used as a substrate, and a glass plate is used as an adherend. It is preferable that the 180 ° peel strength (peeling speed: 300 mm / min) under the RH condition is 0.01 to 5.0 N / 25 mm. A composition having a peeling strength in the above range can be easily peeled off after being attached to an adherend.

The viscosity of the composition is preferably 50 to 500,000 mPa · s, more preferably 100 to 50,000 mPa · s.
In the present invention, the viscosity means a value measured at 25 ° C. using an E-type viscometer (cone plate type viscometer).

The composition of the present invention contains the above-mentioned components (A), (B) and (C) as essential components, but various components can be blended depending on the purpose.

Specific examples of the other components include the component (D) [a compound having one ethylenically unsaturated group other than the component (B)] and an organic solvent [hereinafter referred to as "component (E)"]. Can be mentioned.

Hereinafter, these components will be described.
As the other components described later, only one of the exemplified compounds may be used, or two or more of them may be used in combination.

4-1. Component (D ) Component (D) is a compound having one ethylenically unsaturated group other than the component (B), and is blended for the purpose of imparting various physical properties to the cured film of the composition.
Examples of the ethylenically unsaturated group in the component (D) include (meth) acryloyl group, (meth) acrylamide group, vinyl group and (meth) allyl group, and (meth) acryloyl group is preferable.

As the component (D), a monofunctional (meth) acrylate is preferable.
Specific examples of the monofunctional (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and 2-. Alkyl (meth) acrylates such as ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, and stearyl (meth) acrylate;
Cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, 1,4-cyclohexanedimethylolmono (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and dicyclopentenyloxyethyl (meth) ) (Meta) acrylate having an alicyclic group such as acrylate;
Alkoxyalkyl (meth) acrylates such as 2-methoxyethyl (meth) acrylate and 2-ethoxyethoxyethyl (meth) acrylate;
Glycol mono (meth) acrylates such as ethylene glycol mono (meth) acrylate, propylene glycol mono (meth) acrylate, butanediol mono (meth) acrylate, pentanediol mono (meth) acrylate, and hexanediol mono (meth) acrylate;
Diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, dipropylene glycol mono (meth) acrylate, tripropylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, and polypropylene glycol. Polyalkylene glycol mono (meth) acrylate such as mono (meth) acrylate;
Examples thereof include (meth) acrylate having a heterocycle such as tetrahydrofurfuryl (meth) acrylate.

The monofunctional (meth) acrylate may be a compound having various functional groups.
Examples of compounds having a carboxyl group are (meth) acrylic acid, polycaprolactone modified (meth) acrylic acid, Michael-added multimer of (meth) acrylic acid, 2-hydroxyethyl (meth) acrylate and phthal anhydride. Examples thereof include acid adducts and carboxyl group-containing (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and anhydrous succinic acid adducts.

Examples of the compound having a hydroxyl group include (meth) acrylate having a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypentyl (meth). Examples thereof include hydroxyalkyl (meth) acrylates such as acrylates, hydroxyhexyl (meth) acrylates and hydroxyoctyl (meth) acrylates.

Examples of (meth) acrylates having an imide group include (meth) acrylates having a maleimide group. Examples of the compound having a maleimide group include (meth) acrylate having a hexahydrophthalimide group and (meth) acrylate having a tetrahydrophthalimide group. Specific examples of the (meth) acrylate having a hexahydrophthalimide group include N- (meth) acryloyloxyethyl hexahydrophthalimide and the like. Examples of (meth) acrylates having a tetrahydrophthalimide group include N- (meth) acryloyloxyethyl tetrahydrophthalimide and the like.

Examples of the component (D) other than the monofunctional (meth) acrylate include radically polymerizable vinyl compounds such as (meth) acrylamide compounds and N-vinyl compounds.

The content ratio of the component (D) is preferably 0 to 45% by weight, more preferably 0 to 20% by weight, in 100% by weight of the total amount of the curable components.
By setting the content ratio of the component (D) to 45% by weight or less, it is possible to prevent the cured film from becoming brittle, particularly when the component (D) is a polyfunctional ethylenically unsaturated compound.

4-2. (E) Component The composition of the present invention is most preferably solvent-free, but may contain the organic solvent of the component (E) for the purpose of improving the coatability on the substrate.

Specific examples of the component (E) include aromatic compounds such as benzene, toluene and xylene; ester compounds such as ethyl acetate, butyl acetate and propylene glycol monomethyl ether acetate; and ketone compounds such as methyl ethyl ketone and methyl isobutyl ketone. ..
Among these, aromatic compounds are more preferable in that the components (A) and (B) are excellent in solubility.

The content ratio of the component (E) is preferably 0 to 1,000 parts by weight, more preferably 0 to 500 parts by weight, and 0 to 300 parts by weight with respect to 100 parts by weight of the total amount of the curable component. It is more preferably by weight. Within the above range, the composition can have a viscosity suitable for coating, and the composition can be easily applied by a known coating method described later.

4-3. Other Ingredients Other ingredients other than the above-mentioned (D) and (E) ingredients can be added to the composition of the present invention.
Specific examples thereof include sensitizers, polymerization inhibitors, antioxidants, ultraviolet absorbers, silane coupling agents, surface modifiers and plasticizers.
Hereinafter, these components will be described.

1) Sensitizer The sensitizer is added for the purpose of further enhancing the photoreactivity of the composition.
Examples of the sensitizer include aliphatic amines or aromatic amines such as diethylaminophenone, ethyl dimethylaminobenzoate, and isoacyl dimethylaminobenzoate. Further, in order to reduce migration from the coating film after curing, a high molecular weight type amine can also be used.
The content ratio of the sensitizer is preferably 0 to 5 parts by weight, more preferably 0 to 3 parts by weight, based on 100 parts by weight of the solid content of the composition.

2) Polymerization inhibitor The polymerization inhibitor is added for the purpose of enhancing the thermal stability and photoreactivity of the composition.
Specific examples of the polymerization inhibitor include an organic polymerization inhibitor, an inorganic polymerization inhibitor, and an organic salt polymerization inhibitor. Specific examples of the organic polymerization inhibitor include phenol compounds such as hydroquinone, tert-butylhydroquinone and hydroquinone monomethyl ether, quinone compounds such as benzoquinone, galbinoxyl, 2,2,6,6-tetramethylpiperidine-1-oxyl, 4 Examples thereof include stable radicals such as -hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, phenothiazine, N-nitroso-N-phenylhydroxylamineammonium and the like. Specific examples of the inorganic polymerization inhibitor include copper chloride, copper sulfate and iron sulfate. Specific examples of the organic salt-based polymerization inhibitor include nitroso compounds such as N-nitroso-N-phenylhydroxylamine / aluminum salt and ammonium N-nitrosophenylhydroxylamine, and copper dibutyldithiocarbamate.

Among these, stable radicals and nitroso compounds are preferable because the adhesive is less colored and the composition can be prevented from thickening and gelling to increase stability.
The proportion of the polymerization inhibitor in the curable component is 0.0001 to 1% by mass, more preferably 0.0005 to 0.5% by mass. By setting the ratio of the polymerization inhibitor to 0.0001% by mass or more, the thermal stability and photostability of the composition can be enhanced, and by setting the ratio to 1% by mass or less, the photocurability of the composition is excellent. It will be.

3) Antioxidants Antioxidants are added for the purpose of improving the durability such as heat resistance and weather resistance of the cured film.
Examples of the antioxidant include a phenol-based antioxidant, a phosphorus-based antioxidant, a sulfur-based antioxidant, and the like.
Examples of the phenolic antioxidant include hindered phenols such as 2,6-di-t-butylhydroxytoluene. Examples of commercially available products include AO-20, AO-30, AO-40, AO-50, AO-60, AO-70, and AO-80 manufactured by Adeca Co., Ltd.
Examples of the phosphorus-based antioxidant include phosphines such as trialkylphosphine and triarylphosphine, and trialkyl phosphite and triaryl phosphite. Commercially available products of these derivatives include, for example, Adecaster PEP-4C, PEP-8, PEP-24G, PEP-36, HP-10, 260, 522A, 329K, 1178, 1500, 135A, 3010. And so on.
Examples of the sulfur-based antioxidant include thioether-based compounds, and examples of commercially available products include AO-23, AO-412S, and AO-503A manufactured by Adeca Co., Ltd.
These may be used alone or in combination of two or more. Preferred combinations of these antioxidants include a combination of a phenol-based antioxidant and a phosphorus-based antioxidant, and a combination of a phenol-based antioxidant and a sulfur-based antioxidant.
The content ratio of the antioxidant may be appropriately set according to the purpose, and is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 1 part by weight, based on 100 parts by weight of the total amount of curable components. Is.
The durability of the composition can be improved by setting the content ratio of the antioxidant to 0.1 parts by weight or more, while the curability and adhesion are improved by setting the content to 5 parts by weight or less. be able to.

4) Ultraviolet absorber The ultraviolet absorber is added for the purpose of improving the light resistance of the cured film.
Examples of the ultraviolet absorber include triazine-based ultraviolet absorbers such as TINUVIN400, TINUVIN405, TINUVIN460, and TINUVIN479 manufactured by BASF, and benzotriazole-based ultraviolet absorbers such as TINUVIN900, TINUVIN928, and TINUVIN1130.
The content ratio of the ultraviolet absorber may be appropriately set according to the purpose, and is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 1 part by weight, based on 100 parts by weight of the total amount of curable components. Is. By setting the content ratio of the ultraviolet absorber to 0.01 parts by weight or more, the light resistance of the cured film can be improved, while by setting it to 5 parts by weight or less, the curability of the composition can be improved. It can be excellent.

5) Silane coupling agent The silane coupling agent is blended for the purpose of improving the interfacial adhesive strength between the cured film and the substrate.
The silane coupling agent is not particularly limited as long as it can contribute to improving the adhesiveness with the substrate.

Specific examples of the silane coupling agent include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-. Glycydoxypropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-Aminopropyltriethoxysilane, 3-Aminopropyltrimethoxysilane, 3-Aminopropyltriethoxysilane, 3-Triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3 -Aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like can be mentioned.

The content ratio of the silane coupling agent may be appropriately set according to the purpose, and is preferably 0.1 to 10 parts by weight, more preferably 1 to 5 parts by weight, based on 100 parts by weight of the total amount of curable components. ..
By setting the content of the silane coupling agent to 0.1 parts by weight or more, the adhesive strength of the composition can be improved, while by setting the content of the silane coupling agent to 10 parts by weight or less, the change in adhesive strength with time is prevented. be able to.

6) Surface modifier The composition of the present invention may be added with a surface modifier for the purpose of enhancing the leveling property at the time of coating, the purpose of enhancing the slipperiness of the cured film, and the like.
Examples of the surface modifier include a surface conditioner, a surfactant, a leveling agent, an antifoaming agent, a slipperiness-imparting agent, an antifouling agent, and the like, and these known surface modifiers can be used. ..
Among them, a silicone-based surface modifier and a fluorine-based surface modifier are preferably mentioned. Specific examples include a silicone polymer and an oligomer having a silicone chain and a polyalkylene oxide chain, a silicone polymer and an oligomer having a silicone chain and a polyester chain, and a fluoropolymer having a perfluoroalkyl group and a polyalkylene oxide chain. And oligomers, as well as fluoropolymers and oligomers having a perfluoroalkyl ether chain and a polyalkylene oxide chain.
Further, a surface modifier having an ethylenically unsaturated group, preferably a (meth) acryloyl group in the molecule may be used for the purpose of enhancing the sustainability of slipperiness.

The content ratio of the surface modifier is preferably 0.01 to 1.0 parts by weight with respect to 100 parts by weight of the total amount of the curable components. Within the above range, the surface smoothness of the coating film is excellent.

7) Plasticizer The composition of the present invention may be blended as necessary for the purpose of adjusting the adhesiveness of the cured film.

Examples of the plasticizer include phthalates such as dimethylphthalate, diethylphthalate and dioctylphthalate; aliphatic dibases such as dimethyladipate, dibutyladipate, dioctyladipate, dimethylsevacate, diethylsevacate, dibutylsevacate and diethylsuccinate. Acid esters and aliphatic polybasic acid esters such as tributyl acetylcitrate; orthophosphates such as trimethyl phosphate, triethyl phosphate, triphenyl phosphate and tricresyl phosphate; such as glyceryl triacetate and 2-ethylhexyl acetate. Acetate esters; Subphosphate esters such as triphenylphosphite and dibutylhydrodienephosphite; Natural resins such as rosin-based resins and terpene-based resins and their derivatives; and polyesters and acrylic polymers (eg, manufactured by Toa Synthetic). Alfon UP-1000), inert compounds such as polyethers and petroleum resins and the like can be mentioned.

The content ratio of the plasticizer may be appropriately set according to the intended purpose, but is preferably 1 to 90% by weight, more preferably 5 to 80% by weight in the composition.

5. Method of use As a method of using the composition of the present invention, a conventional method may be followed.
Specific examples thereof include a method of applying a composition to a substrate and irradiating it with active energy rays to cure it, and a method of bonding it to another substrate and then further irradiating it with active energy rays to cure it.
Further, the coating range for the base material may be appropriately selected according to the purpose, and may be partially coated or fully coated.

The base material may be a material for the purpose of adhesion (hereinafter referred to as “adhesive body”), or a sheet or film having mold releasability (hereinafter referred to as “release material”).

Examples of the material of the adherend include polymers, paper, glass, ceramics, metals such as steel plates and aluminum, vapor-deposited films of metals and metal oxides, and silicon.
Polymers include cellophane, polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyamide, polyimide, polycarbonate, urea-melamine resin, epoxy resin, polyurethane, polylactic acid, polyethylene, polypropylene, cycloolefin polymer, acrylic resin, methacrylic resin, and poly. Examples thereof include vinyl chloride, polystyrene, polyvinyl acetate, polyvinyl alcohol, triacetyl cellulose, hydroxypropyl cellulose, polyether sulfone, copolymers of the above polymers, liquid crystal polymers and fluororesins. The shape of these polymers is preferably a film or a sheet.
Examples of the paper include high-quality paper, coated paper, art paper, imitation paper, thin paper, and thick paper.

Examples of the mold release material include a material obtained by subjecting the polymer mentioned as the adherend to a mold release treatment. Specific examples of the mold release treatment include silicone treatment, fluorine treatment, and long-chain alkyl treatment. Further, it is possible to use a polymer having a small surface free energy as it is, and specific examples thereof include polyethylene, polypropylene, cycloolefin polymer, and fluororesin.

The coating method may be appropriately set according to the purpose, and may be appropriately set according to the purpose, such as a bar coater, an applicator, a doctor blade, a dip coater, a roll coater, a spin coater, a flow coater, a knife coater, and a comma. Examples thereof include a method of coating with a coater, a reverse roll coater, a die coater, a lip coater, a gravure coater, a micro gravure coater, an inkjet, and the like.

Examples of the active energy ray for curing the composition of the present invention include ultraviolet rays, visible rays, electron beams and the like, but ultraviolet rays are preferable.
Examples of the ultraviolet irradiation device include a high-pressure mercury lamp, a metal halide lamp, an ultraviolet electrodeless lamp, and an ultraviolet light emitting diode (UV-LED).
The irradiation energy may be appropriately set according to the type of active energy ray and the compounding composition, and varies depending on the thickness and illuminance of the coating film. For example, when a high-pressure mercury lamp is used, the irradiation energy in the UV-A region is used. 10 to 2,000 mJ / cm ² is preferable, and 10 to 1,000 mJ / cm ² is more preferable.

6. Adhesive Sheet The composition of the present invention can be preferably used in the production of an adhesive sheet.
As a method for producing the pressure-sensitive adhesive sheet, a conventional method may be followed. For example, the pressure-sensitive adhesive sheet can be produced by applying the composition to a substrate and then irradiating it with active energy rays.

If the composition is solvent-free, the composition is applied to the substrate. When the composition is an organic solvent or the like, the composition is applied to a base material and then dried to evaporate the organic solvent or the like.
By irradiating the sheet on which the composition layer is formed on the base material with active energy rays, an adhesive sheet composed of the base material / cured film can be obtained. Irradiation of the active energy ray is usually performed from the composition layer side, but can also be irradiated from the base material side.

The coating amount of the composition of the present invention may be appropriately selected depending on the intended use, but the film thickness after drying the organic solvent or the like is preferably 1 to 100 μm, preferably 5 to 50 μm. It is more preferable to have.

If the composition contains an organic solvent or the like, it is dried after coating to evaporate the organic solvent or the like.
The drying conditions may be appropriately set according to the organic solvent or the like used, and examples thereof include a method of heating to a temperature of 40 to 150 ° C.

Irradiation conditions such as irradiation energy in active energy ray irradiation may be appropriately set according to the composition, the base material, the purpose and the like to be used, and may follow the same conditions as described above.

7. Uses The pressure-sensitive adhesive sheet formed from the composition of the present invention can be used for various purposes such as pressure-sensitive adhesive labels, pressure-sensitive adhesive tapes, and special pressure-sensitive adhesive films. In particular, examples of preferred applications include re-peeling applications.

Specific examples of adhesive labels include trademark labels, quality label, content label, returnable label, name plate and other product labels, weighing label, hand label, price tag / price label and other price labels, instruction label, and inspection. Certificate label, warranty label, tamper-proof label, distribution chart label, scale plate label, PL law warning label, etc. for explanation / warranty, stickers (for windows, vehicles, storefronts, etc.), marks / decorative labels, stamps , Stickers, emblems, posters, multi-layer labels, etc. for advertising / promotion, form labels, computer labels, POS labels, process / inventory management labels, etc., double-sided / single-sided tag labels, address labels, home delivery slips Labels and other tags / addresses, sealing stickers, cap stickers, etc., guidance sign labels, traffic sign labels, facility sign labels, etc. for guidance / signs, toiletry-related labels, home appliance labels, OA equipment labels, etc. For recycling, other index labels (for stationery, Blu-ray discs, etc.), color sample labels, toys (seals), teaching materials, etc.

Adhesive tapes include name plate tapes, tapes for metal building materials, tapes for automobiles, etc., tapes for semiconductor manufacturing processes, tapes for transporting electronic parts, tapes for protection / masking, tapes for fixing / adhesives, and electrical insulation. For electrical / electronic equipment such as tapes for binding / repair, conductive tapes, for labeling / sealing on EPS (expanded polystyrene bead fusion products) cases, for general masking such as paint masking tapes and curing masking tapes. , For sealing and packaging of cardboard wrapping tape, for office use, other applications for automobile decoration tape, photoengraving tape, splicing tape, etc., for general binding and fixing applications such as double-sided tape, cellophane tape, OPP tape, etc. Can be mentioned.

Special adhesive films include outdoor advertising films, automotive stripes, marking films and other outdoor durable films, posters, interior films, interior materials and other general wall coverings, elevator interior films, counter decorative films, furniture decorative films, vehicle interior films. , Vending machine decorative film, cash corner decorative film, table decorative film, etc. for interior cosmetics, wind display film, stickers, marking film, etc. for short-term decoration, outdoor durable film, etc. for interior lighting signs, building sunshade and shatterproof For films, for safety reflective films (for automobiles, shoes, helmets, etc.), for automobiles, etc., as window films that can be applied while moistening with water or soapy water, as well as prisms, hologram films, light-harvesting films, and light-emitting films. And so on.

The composition of the present invention can be preferably used for re-peeling because the composition is excellent in coatability and curability, and the cured film is excellent in adhesive strength and re-peelability.
Specific examples of the re-peelable application include distribution management labels for office use and products, etc., for labels that can be repeatedly affixed.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.
In the following, "part" means a part by weight.

1. 1. Examples 1 to 9 and Comparative Examples 1 to 4
1) Preparation of active energy ray-curable pressure-sensitive adhesive composition The compounds shown in Table 1 were stirred and mixed at the ratios shown in Tables 1 and 2 to produce an active energy ray-curable pressure-sensitive adhesive composition.
The obtained composition was used and evaluated later. The results are shown in Table 3.
The numbers in Tables 1 and 2 mean the number of copies.
The abbreviations in Tables 1 and 2 mean the following.

(1) Ingredients (A) -M1200: Non-yellowing polyester skeleton urethane acrylate (Mw4,500), "Aronix M-1200" manufactured by Toagosei Co., Ltd. (trade name)
UN6200: Non-yellowing type polyether skeleton urethane acrylate (Mw6,500), "Art Resin UN-6200" manufactured by Negami Kogyo Co., Ltd. (trade name)
-UN353: Non-yellowing polyester skeleton urethane acrylate (Mw5,000), "Art Resin UN-353" manufactured by Negami Kogyo Co., Ltd. (trade name)
-UN7600: Non-yellowing polyester skeleton urethane acrylate (Mw11,500), "Art Resin UN-7600" manufactured by Negami Kogyo Co., Ltd. (trade name)
OT1001: Isobornyl acrylate (hereinafter referred to as "IBXA") 50% by weight diluted product of non-yellowing polyester skeleton urethane acrylate (Mw40,000), "Aronix OT-1001" (trade name) manufactured by Toagosei Co., Ltd. .. In Table 2, the urethane acrylate corresponding to the component (A) and the IBXA corresponding to the component (D) are listed separately.

(2) Component (B) -M111: Nonylphenol ethylene oxide modified (n = 1) acrylate, liquid surface tension = 35.8 mN / m, "Aronix M-111" manufactured by Toagosei Co., Ltd. (trade name)
-M113: Nonylphenol ethylene oxide modified (n = 4) acrylate, liquid surface tension = 35.7 mN / m, "Aronix M-113" (trade name) manufactured by Toagosei Co., Ltd.
M101A: Phenol ethylene oxide-modified (n = 2) acrylate, liquid surface tension = 44.6 mN / m, "Aronix M-101A" manufactured by Toagosei Co., Ltd. (trade name)

(3) (C) component -E-ONE: Poly {2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane-1-one}, "ESACURE ONE" manufactured by IGM Resins. (Product name)
-KIP160: 2-Hydroxy-1- {4- [4- (2-hydroxy-2-methylpropionyl) phenoxy] phenyl} -2-methylpropanone, "ESACURE KIP-160" manufactured by IGM Resins (trade name)
SBPI 718: 2,4,6-trimethylbenzoyldiphenylphosphine oxide, "SB-PI 718" manufactured by Sogoku Minoru Co., Ltd. (trade name)
SBPI719: Bis (2,4,6-trimethylbenzoyl) -Phenylphosphine oxide, "SB-PI 719" manufactured by Sogoku Minoru Co., Ltd. (trade name)

(4) (C)'Component -SBPI714: 1-hydroxycyclohexylphenyl ketone, "SB-PI 714" manufactured by Sogoku Minoru Co., Ltd. (trade name)

(5) Ingredient (D) -M5700: 2-hydroxy-3-phenoxypropyl acrylate, cured product Tg = 17 ° C., "Aronix M-5700" manufactured by Toagosei Co., Ltd. (trade name)
-BC190: Ethylcarbitol acrylate, cured product Tg = -67 ° C, "Viscoat # 190" manufactured by Osaka Organic Chemical Industry Co., Ltd. (trade name)
-HBA: 4-Hydroxybutyl acrylate, cured product Tg = -80 ° C, manufactured by Osaka Organic Chemical Industry Co., Ltd.

2) Evaluation method of composition
(1) Viscosity The compositions obtained in Tables 1 and 2 were measured for viscosity at 25 ° C. using an E-type viscometer. The results are shown in Table 3.
(2) Workability
The compositions obtained in Tables 1 and 2 were prepared into a polyethylene terephthalate film having a width of 300 mm and a length of 300 mm so as to have a film thickness of 40 μm [Cosmo Shine A4300 (thickness 50 μm) manufactured by Toyobo Co., Ltd.). Hereinafter, it is referred to as "PET"] to form a coating film, and the coatability at this time is evaluated at the following three levels. The results are shown in Table 3.
◯: The film thickness of the coating film does not vary in the plane and is uniform.
Δ: The film thickness of the coating film has a small variation in the plane.
X: The film thickness of the coating film varies widely in the plane and is not uniform.

3) Evaluation method of cured film
◆ Manufacture of Adhesive Sheet A release PET film with a width of 300 mm and a length of 300 mm [Cerapir BKE (manufactured by Toray Film Processing Co., Ltd.)) is applied to the coating film on PET obtained in the above 2) and (2) coatability evaluations. Thickness 38 μm). Hereinafter referred to as "release PET"] was laminated.
Next, a conveyor-type ultraviolet irradiation device manufactured by Igraphics Co., Ltd. (160 W / cm high-pressure mercury lamp, lamp height 10 cm, irradiation intensity in the UV-A region 1,200 mW / cm ² (UV POWER PUCK manufactured by Heleus Co., Ltd.) By passing through a 7 m / min conveyor using the measured value), ultraviolet rays with an irradiation energy of 200 mJ / cm ² in the UV-A region are irradiated from the release PET side (hereinafter referred to as "irradiation condition 1"). Obtained an adhesive sheet.
The release PET of the obtained adhesive sheet was peeled off and evaluated later.
By using the same ultraviolet irradiation device as above and passing through a 36 m / min conveyor whose conveyor speed is faster than that of irradiation condition 1, the material laminated by the same method as above is used on the release PET side. Further, ultraviolet irradiation with an irradiation energy of 40 mJ / cm ² in the UV-A region was performed (hereinafter referred to as "irradiation condition 2") to obtain an adhesive sheet.
The release PET of the obtained adhesive sheet was peeled off and evaluated later.
The results are shown in Table 3.

(1) Curability The acryloyl group reaction rate of the composition before curing and the cured film cured under irradiation condition 1 was measured by infrared absorption spectroscopy [μ-ATR method]. As an infrared absorption spectrum measuring device, a Spectrum 100 manufactured by PerkinElmer Japan Co., Ltd. was used.
Using the obtained ultraviolet absorption spectrum, the acryloyl group reaction rate was calculated by the following formula (1).
Acryloyl group reaction rate = {1- (B2 / A2) / (B1 / A1)] × 100 ... (1)
A1: Peak height of 1724 cm ^-1 derived from -C = O of the composition B1: Peak height of 1405 cm ^-1 derived from -CH = CH ₂ of the composition A2: Derived from -C = O of the cured film 1724 cm ^-1 peak height B2: 1405 cm ^-1 peak height derived from -CH = CH ₂ of the cured film Follow the same method as above to determine the acryloyl group reaction rate of the cured film cured under irradiation condition 2. It was measured.

(2) Adhesive strength Using the test piece obtained under the irradiation condition 1, the adhesive strength was measured according to JIS Z 0237: 2009.
Specifically, a glass plate was used as an adherend, and 180 ° peel strength (peeling speed: 300 mm / min) was measured under the conditions of 23 ° C and 50% RH.
For the measurement of the peel strength, the universal material testing machine Instron 5564 manufactured by Instron Japan Company Limited was used.

(3) Removability With respect to the test pieces obtained under irradiation conditions 1 and 2, the surface condition of the glass plate after the PET was peeled off under the same conditions as the adhesive strength measurement in (2) above was visually observed, and the following was observed. The evaluation was made at the two levels of.
〇: No adhesive residue can be seen on the surface of the glass plate.
X: Adhesive residue is seen on the surface of the glass plate.

(4) Using the test piece obtained under the odor irradiation condition 1, the glass plate after the adhesive strength measurement in (2) was peeled off, the odor of the adhesive layer was smelled, and the evaluation was performed at the following three levels. ..
〇: There is no odor.
Δ: There is a slight odor.
×: Has a strong odor.

(5) Light stability 20 g of the composition before curing was placed in a 100 cc polycup and allowed to stand directly under a straight tube 32 type UV cut fluorescent lamp × 2 lamps (light source distance 2 m). After that, it was visually observed every hour, and the time until the gelled product was partially generated was measured.

4) Evaluation Results As is clear from the results of Examples 1 to 9, the composition of the present invention has a low odor, excellent curability, excellent curability even under low energy irradiation conditions, and further obtains a cured film. It was excellent in adhesive strength and removability.
In addition, the compositions of Examples 1 to 5, 8 and 9 containing M111 and M113, which are compounds having a long-chain alkyl group and an oxyalkylene unit having 1 or more repetitions, as the component (B) are coated. It was also excellent in workability. Further, the compositions of Examples 1 to 7 containing the component (C-1) as the component (C) were also excellent in light stability.
On the other hand, the composition of Comparative Example 1 containing no component (A) has a low odor, is excellent in curability, and is excellent in the adhesive strength of the obtained cured film, but in any of the irradiation conditions 1 and 2. However, the removability has decreased. Further, the composition of Comparative Example 2 containing no component (B) had a low odor, was excellent in curability, and was excellent in removability of the obtained cured film, but the adhesive strength and coatability were deteriorated. .. Further, the composition of Comparative Example 3 containing no component (B) has excellent adhesive strength of the obtained cured film, but has an odor, and the curability under irradiation condition 2 which is low irradiation energy is lowered. In both cases of irradiation conditions 1 and 2, the removability was lowered. Further, the composition of Comparative Example 4 containing a photopolymerization initiator different from the component (C) has excellent adhesive strength of the obtained cured film but has a slight odor, and has curability and removability under irradiation condition 2. Has dropped.

The active energy ray-curable pressure-sensitive adhesive composition of the present invention can be used for various purposes such as pressure-sensitive adhesive labels, pressure-sensitive adhesive tapes, and special pressure-sensitive adhesive films, and can be particularly preferably used for re-peeling applications.

Claims (11)

An active energy ray-curable pressure-sensitive adhesive composition containing the following components (A), (B) and (C) as essential components and not containing a compound having a mercapto group in the molecule .
-Component (A): A compound having two or more ethylenically unsaturated groups including urethane (meth) acrylate -Component (B): having an aromatic group and one ethylenically unsaturated group , and oxy Compounds with alkylene units -Component (C): Photopolymerization initiator with a molecular weight of 300 or more excluding (C-1) acylphosphine oxide-based compound and / and light containing (C-2) acylphosphine oxide-based compound as an essential component Polymerization initiator The active energy ray-curable pressure-sensitive adhesive composition according to claim 1 , wherein the component (B) is a compound having a long-chain alkyl group having 4 to 12 carbon atoms and an oxyalkylene unit having 1 or more repetitions. The active energy ray-curable pressure-sensitive adhesive composition according to claim 1 or 2, wherein the component (C) contains a photopolymerization initiator having a molecular weight of 300 or more excluding the (C-1) acylphosphine oxide compound. The active energy ray-curable pressure-sensitive adhesive composition according to claim 3 , wherein the component (C-1) contains an α-hydroxyketone-based compound. The total amount of the components (A) and (B) is 100% by weight, and the component (A) is contained in an amount of 5 to 50% by weight and the component (B) is contained in an amount of 50 to 95% by weight. The active energy ray-curable pressure-sensitive adhesive composition according to any one of claims 1 to 4 , which contains 0.1 to 15 parts by weight of the component (C) with respect to 100 parts by weight of the total amount. The active energy ray-curable pressure-sensitive adhesive composition according to any one of claims 1 to 5 , further comprising the following component (D).
-Component (D): A compound having one ethylenically unsaturated group other than the component (B). In the total amount of 100% by weight of the components (A), (B) and (D), the component (A) is 5 to 50% by weight, the component (B) is 50 to 95% by weight, and the component (D) is added. The activity according to claim 6 , which contains 45% by weight or less and contains 0.1 to 15 parts by weight of the component (C) with respect to 100 parts by weight of the total amount of the components (A), (B) and (D). Energy ray curable pressure-sensitive adhesive composition. When the cured film of the composition has a film thickness of 40 μm, a polyethylene terephthalate film is used as a substrate, and a glass plate is used as an adherend, 180 ° peel strength (peeling speed: 300 mm) under the conditions of 23 ° C and 50% RH. The active energy ray-curable pressure-sensitive adhesive composition according to any one of claims 1 to 7 , wherein / min) is 0.01 to 5.0 N / 25 mm. An active energy ray-curable pressure-sensitive adhesive composition for removing, which comprises the composition according to any one of claims 1 to 8 . A pressure-sensitive adhesive film or sheet composed of a base material and a pressure-sensitive adhesive layer composed of an active energy ray-cured film according to any one of claims 1 to 9 . A method for producing an adhesive film or sheet, which comprises applying the composition according to any one of claims 1 to 9 to a base material and then irradiating the base material with active energy rays.