JP2020122120A - Photocurable resin composition for temporary fixing or masking - Google Patents

Abstract

To provide a photocurable resin composition for temporary fixing or masking, applicable by a dispenser or various printing methods, curable by UV irradiation, excellent in surface dryness, and further its cured product has high solubility to water.SOLUTION: A photocurable resin composition for temporary fixing or masking, contains a radical polymerization reactive monomer (A), a chain transfer agent (B), and a photoinitiator (C). and has a viscosity of 100-100,000 mPa-s at 25°C. The photocurable resin composition for temporary fixing or masking, further contains, in the component (A), a radical polymerization reactive monomer (A1) having one (meth)acrylamide group in a molecule as much as 30-100 wt.%.SELECTED DRAWING: None

Description

The present invention relates to a photocurable resin composition for temporary fixing or masking.

Water-soluble polymers (water-soluble polymers) are used in various applications. Masking to prevent scratches, adhesion of dirt, deterioration, etc. by temporarily protecting the base material etc. with a film, and temporary fixing to temporarily bond one member to another member, Is one. Since these need to be removed after the intended processing, a polymer that can be removed by washing with water is suitable.

In Patent Document 1, a masking material containing a water-soluble polyester resin is dissolved in a solvent such as water to form a solution, and after applying a necessary amount, the solvent is scattered by heating for a certain period of time to form a masking material film. Is disclosed.

On the other hand, ultraviolet (UV) curable plastics are widely used as optical materials due to their features such as ease of molding and light weight. Patent Document 2 discloses an ultraviolet curable resin composition containing a hydrophobic component as a temporary fixing material when processing a member. Patent Document 2 discloses that a base material having a cured film of a temporary fixing material is immersed in water at a high temperature of about 80° C. for several tens of minutes to swell the cured film of the temporary fixing material and then peeled off. ing.

JP, 2013-245255, A JP, 2010-100831, A

The method of forming a film of a masking material after forming a solution as disclosed in Patent Document 1 is not suitable for mass production because it takes time. Furthermore, the masking material used by dissolving it in an organic solvent may affect the environment.

The acrylic resin generally used as a component contained in the ultraviolet curable resin composition as described in Patent Document 2 is likely to be uncured in a portion in contact with air due to oxygen inhibition during ultraviolet curing. However, there is a risk that the uncured liquid component remaining on the surface of the cured product may contaminate members, processing equipment, and the like. Further, the method of removing the temporary fixing material disclosed in Patent Document 2 is time-consuming and cannot be used for a member that is weak against heat.

The present invention provides a photocurable resin composition that can be applied by a dispenser or various printing methods, is cured by irradiation with energy rays and has excellent surface dryness, and that the cured product has high solubility in water. The purpose is to provide.

The present invention relates to the following.
[1] Light for temporary fixing or masking, which contains a radical polymerization reactive monomer (A), a chain transfer agent (B) and a photopolymerization initiator (C) and has a viscosity of 100 to 100,000 mPa·s at 25° C. A curable resin composition, characterized in that the component (A) contains 30 to 100% by weight of a radical polymerization-reactive monomer (A1) having one (meth)acrylamide group in the molecule. A photocurable resin composition for fixing or masking.
[2] The photocurable resin according to [1], further containing one or more additional components (D) selected from the group consisting of a water-soluble polymer (d1) and a thixotropic agent (d2) containing an inorganic substance. Composition.
[3] The photocurable resin composition according to [2], wherein the component (D) contains a water-soluble polymer (d1), and the weight average molecular weight of the component (d1) is 300 to 100,000.
[4] The photocurable resin composition according to any one of [1] to [3], wherein the component (B) is a compound having a thiol group or α-methylstyrene dimer.
[5] The photocurable resin composition according to any one of [1] to [4], wherein the content of the component (B) in the photocurable resin composition is 0.7 to 15% by weight.

According to the present invention, a photocurable resin composition that can be applied by a dispenser or various printing methods, is cured by irradiation with energy rays and has excellent surface dryness, and that the cured product has high solubility in water. Can provide things.

[Definition of terms]
“(Meth)acrylate” means at least one of acrylate and methacrylate.
The “(meth)acryloyl group” has at least one of an acryloyl group and a methacryloyl group.
The "radical polymerization-reactive monomer (A)" is also referred to as "component (A)". The same applies to the "chain transfer agent (B)" and the like.

[Photocurable resin composition for temporary fixing or masking]
The photocurable resin composition for temporary fixing or masking (hereinafter, also simply referred to as “photocurable resin composition”) includes a radical polymerization reactive monomer (A), a chain transfer agent (B) and a photopolymerization initiator (C). ), the viscosity is 100 to 100,000 mPa·s at 25° C., and the radical polymerization reactive monomer (A1) having one (meth)acrylamide group in the molecule in the component (A) is 30 to 100% by weight. %contains.

<Radical Polymerization Reactive Monomer (A)>
The radical polymerization reactive monomer (A) is not particularly limited as long as it has a radical polymerization reactive functional group. The radical polymerization reactive functional group is not particularly limited as long as it is an unsaturated double bond-containing group, but an alkenyl group (for example, vinyl group, allyl group, etc.) or a (meth)acryloyl group is preferable, and a (meth)acryloyl group. Is particularly preferable.

<<Radical Polymerization Reactive Monomer (A1) Having One (Meth)acrylamide Group in the Molecule>>
The radical polymerization reactive monomer (A) contains a radical polymerization reactive monomer (A1) having one (meth)acrylamide group in the molecule. The component (A1) is a compound having a (meth)acrylamide group as a radical polymerization reactive group. Examples of the component (A1) include compounds represented by the following formula (1).

[In the formula,
R ¹ is a hydrogen atom or a methyl group,
R ² and R ³ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, or an aryl group which is unsubstituted or substituted with one or more selected from the group consisting of a hydroxyl group and an alkyl group. Or
R ² and R ³ together with the N atom to which they are attached form an alicyclic group which can contain an oxygen atom (preferably a morpholino group).

In the formula (1), the number of carbon atoms in the alkyl moiety of the alkyl group and the hydroxyalkyl group is preferably 1-18, and particularly preferably 1-6. The aryl group preferably has 6 to 20 carbon atoms. Further, the aryl group is preferably a phenyl group. In addition, the morpholino group refers to a monovalent group in which the hydrogen atom of the secondary amine portion of morpholine has been removed.

Component (A1) includes (meth)acrylamide; N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-butyl(meth)acrylamide and the like having 1 to 4 carbon atoms. N-alkyl(meth)acrylamide having an alkyl group of N;N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, or another N,N-dialkyl(having an alkyl group having 1 to 4 carbon atoms). (Meth)acrylamide; C2-C4 such as N-(2-hydroxyethyl)(meth)acrylamide, N-(3-hydroxypropyl)(meth)acrylamide, N-(4-hydroxybutyl)(meth)acrylamide, etc. N-hydroxyalkyl(meth)acrylamide having an alkyl group; N-phenyl(meth)acrylamide, N-(2-hydroxyphenyl)(meth)acrylamide, N-(3-hydroxyphenyl)(meth)acrylamide, N-( (Meth)acrylamide having an unsubstituted or substituted aryl group such as 4-hydroxyphenyl)(meth)acrylamide, N-(2-methylphenyl)(meth)acrylamide; cyclic structure such as 4-(meth)acryloylmorpholine And (meth)acrylamide having N-hydroxyethyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, 4-(meth)acryloylmorpholine are preferable, and N-hydroxyethyl(meth)acrylamide is particularly preferable from the viewpoint of further increasing the solubility (water solubility) of the cured product of the curable resin composition in water.
The component (A1) may be one type or a combination of two or more types.

<<Radical Polymerization Reactive Monomer (A2) Other Than Component (A1)>>
The radical polymerization reactive monomer (A2) other than the component (A1) is a radical polymerization reactive monomer other than the radical polymerization reactive monomer having one (meth)acrylamide group in the molecule. The component (A2) is not particularly limited, but is preferably a (meth)acrylate monomer having a (meth)acryloyl group.

<<<(meth)acrylate monomer>>
Examples of the (meth)acrylate monomer include alicyclic (meth)acrylate monomers, hydroxyl group-containing (meth)acrylate monomers, aromatic (meth)acrylate monomers, alkyl (meth)acrylate monomers, and (meth)acrylate monomers having a heterocyclic structure. Etc.

The (meth)acrylate monomers may each be a single type or a combination of two or more types. For example, the (meth)acrylate monomer may be a combination of one or more kinds of hydroxyl group-containing (meth)acrylate monomer and one or more kinds of (meth)acrylate monomer having a heterocyclic structure.

Examples of the alicyclic (meth)acrylate monomer include isobornyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, norbornene (meth)acrylate, dicyclopentanyl (meth)acrylate and cyclohexyl (meth)acrylate. ..

Examples of the hydroxyl group-containing (meth)acrylate monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and diethylene glycol monoethyl ether (meth)acrylate. (Meth)acrylate is preferred. Further, the hydroxyl group-containing (meth)acrylate monomer may be a polyol poly(meth)acrylate (provided that it contains a hydroxyl group). Examples of the poly(meth)acrylate of the polyol include trimethylolpropane di(meth)acrylate and poly(meth)acrylate of polypentaerythritol.

Examples of the alkyl (meth)acrylate monomer include methyl (meth)acrylate, ethyl (meth)acrylate, tert-butyl (meth)acrylate, isooctyl (meth)acrylate, isomyristyl (meth)acrylate, and lauryl (meth)acrylate. To be

Examples of the (meth)acrylate monomer having a heterocyclic structure include tetrahydrofurfuryl (meth)acrylate.

Aromatic (meth)acrylate monomers include benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, ethoxylated o-phenylphenol acrylate, phenoxybenzyl (meth)acrylate, naphthalene (meth)acrylate, ethoxylated bisphenol A di(meth). ) Acrylate, modified bisphenol A di(meth)acrylate and the like.

The (meth)acrylate monomer preferably contains at least one selected from the group consisting of a (meth)acrylate monomer having a heterocyclic structure and a hydroxyl group-containing acrylate monomer.
The component (A2) may be one kind or a combination of two or more kinds.

<Chain transfer agent (B)>
The chain transfer agent (B) is a component that causes a chain transfer reaction. Here, the chain transfer reaction refers to a reaction in a radical polymerization in which a growing radical reacts with another chemical species in the polymerization system, which is accompanied by stopping the growth, transferring the radical, and restarting the growth. As the component (B), α-methylstyrene, α-methylstyrene dimer; alcohols such as methanol, ethanol, propanol and butanol; aldehydes such as acetaldehyde, propionaldehyde, n-butyraldehyde, furfural and benzaldehyde; carbon tetrachloride. , Halogens such as chloroform; and pentaerythritol tetrakis(3-mercaptobutyrate), 1,4-bis(3-mercaptobutyryloxy)butane, dodecyl mercaptan, lauryl mercaptan, normal mercaptan, thioglycolic acid, thioglycol. One or more compounds selected from the group consisting of compounds having a thiol group such as octyl acid and thioglycerol are exemplified, and a compound having a thiol group or α-methylstyrene dimer is preferable.
The component (B) may be one kind or a combination of two or more kinds.

<Photopolymerization initiator (C)>
The photopolymerization initiator (C) is not particularly limited as long as it is a compound that generates radicals upon irradiation with energy rays. Component (C) is 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, benzophenone, 2, 2-dimethoxy-1,2-diphenylethan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, 2-benzyl-2-dimethylamino-1 -(4-morpholinophenyl)butanone-1,2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-methyl-1-[4-methylthio]phenyl]-2-morpholinopropane-1- On, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone], oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl] ] Propanone], benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether, benzoin isopropyl ether, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, oligo-2-hydroxy-2-methyl-1-[4- (1-methylvinyl)phenyl]propanol, oligo 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanol, 2-hydroxy-2-methyl-1-phenyl-1-propanone, Isopropylthioxanthone, methyl o-benzoylbenzoate, [4-(methylphenylthio)phenyl]phenylmethane, 2,4-diethylthioxanthone, 2-chlorothioxanthone, benzophenone, ethylanthraquinone, benzophenone ammonium salt, thioxanthone ammonium salt, bis( 2,6-Dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzophenone , 4-methylbenzophenone, 4,4'-bisdiethylaminobenzophenone, 1,4 dibenzoylbenzene, 10-butyl-2-chloroacridone, 2,2'bis(o-chlorophenyl)4,5,4',5 '-Tetrakis(3,4,5-trimethoxyphenyl)1,2'-biimidazole,2,2'bis(o-chlorophenyl)4,5,4',5'-tetra Phenyl-1,2′-biimidazole, 4-benzoyldiphenyl ether, acrylated benzophenone, bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole- 1-yl)-phenyl)titanium, o-methylbenzoylbenzoate, p-dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid isoamylethyl ester, active tertiary amine, carbazole/phenone-based photopolymerization initiator, acridine-based Examples thereof include a photopolymerization initiator, a triazine-based photopolymerization initiator, and a benzoyl-based photopolymerization initiator.

Examples of commercially available component (C) include KIP-150 manufactured by DKSH Japan, Irgacure 184, Irgacure 819, Irgacure 127, Irgacure 1173, and the like, Irgacure (registered trademark) series, Darocur LPOc series, such as Darocur 1373, and Darocur (registered trademark) series. Lucirin (registered trademark) series, ESACUR 1001M manufactured by Japan Siber Hegner Co., Ltd., and the like. Irgacure 1173 (Irgacure 1173) and Irgacure 184 (Irgacure 184) are used from the viewpoint of making oxygen inhibition which is an uncured factor less likely to occur in the radical reaction of the component (A), and from the viewpoint of solubility in the component (A) and water. preferable.
The component (C) may be one type or a combination of two or more types.

<Further ingredients (D)>
The photocurable resin composition can contain a further component (D), if necessary, within a range that does not impair the effects of the present invention. As the component (D), a water-soluble polymer (d1), a thixotropic agent (d2) containing an inorganic substance, a silane coupling agent, a surfactant, a slip agent, a polymerization inhibitor, a photosensitizer, an antioxidant, and a stability. Agents, colorants, solvents, fillers (for example, water-soluble plasticizer (d3), water-soluble filler (d4), or water-insoluble filler), and the like, water-soluble polymer (d1), thixo containing inorganic substance The imparting agent (d2), the water-soluble plasticizer (d3), and the water-soluble filler (d4) are preferable. When the photocurable resin composition contains the water-soluble polymer (d1) and the thixotropic agent (d2) containing an inorganic substance, the viscosity of the photocurable resin composition can be efficiently increased, which is more preferable.
Each of the component (D) may be one kind or a combination of two or more kinds.

<<Water-soluble polymer (d1)>>
The water-soluble polymer (d1) is not particularly limited as long as it does not have a radical-polymerization reactive functional group and has a property of being soluble in both water and the photocurable resin composition. As the component (d1), polyoxyalkylene such as polyethylene glycol, polypropylene glycol, a copolymer of polyethylene glycol and polypropylene glycol, polyvinyl alcohol; cellulose derivative such as hydroxymethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose; starch decomposition product, hydroxy Propyl etherified starch, sodium alginate, gelatin, polysaccharides such as xanthan gum; and the like.

The weight average molecular weight of the water-soluble polymer (d1) is preferably 300 to 100,000, more preferably 500 to 50,000, and particularly preferably 500 to 20,000. When the weight average molecular weight of the component (d1) is within the above range, the viscosity of the photocurable resin composition can be efficiently increased, and the photocurable resin composition after UV curing has high water solubility. As a method of measuring the weight average molecular weight, a method of converting the measurement result of gel permeation chromatography (GPC) using a calibration curve of standard polystyrene is generally known for components having a relatively high molecular weight such as oligomers and polymers. Has been. Further, since the monomer does not have a molecular weight distribution, it can be obtained from the structural formula.

<< thixotropic agent (d2) containing inorganic matter >>
The thixotropic agent (d2) containing an inorganic substance is not particularly limited as long as it has a high thickening or thixotropy effect even when added in a small amount. The inorganic substances contained in the component (d2) include fumed silica, calcium carbonate, carbon black, kaolin, clay, activated clay, silica sand, silica stone, diatomaceous earth, anhydrous aluminum silicate, hydrous magnesium silicate, talc, Examples include perlite, white carbon, fine powder of mica, bentonite, and the like. Further, the component (d2) may be composed of only an inorganic material, or may be an inorganic material surface-treated with a fatty acid and/or a resin acid.

<<Water-soluble plasticizer (d3), Water-soluble filler (d4)>>
The water-soluble plasticizer (d3) and/or the water-soluble filler (d4) are components added when controlling properties such as hardness of the photocurable resin composition and the cured product thereof.
The water-soluble plasticizer (d3) is a material which is not a polymer but is soluble in both water and a photocurable resin composition and has no radical reactivity. The molecular weight of the water-soluble plasticizer is preferably less than 500, particularly preferably less than 300.
The water-soluble filler (d4) refers to a filler that does not dissolve in the photocurable resin composition but dissolves in water.
The component (d3) and the component (d4) are not particularly limited as long as they are components usually used in the photocurable resin composition, and can be appropriately selected depending on the purpose.

Further components other than the above components are not particularly limited as long as they are components usually used in the photocurable resin composition, and can be appropriately selected according to the purpose.

(Composition and characteristics, etc.)
<Viscosity>
The viscosity of the photocurable resin composition is 100 to 100,000 mPa·s at 25°C. Since the photocurable resin composition has a viscosity of 100 to 100,000 mPa·s at 25° C., it can be applied by a dispenser or various printing methods. The viscosity of the photocurable resin composition at 25° C. is preferably 200 to 80,000 mPa·s, and particularly preferably 300 to 50,000 mPa·s. The viscosity is a value measured using an E-type viscometer at 25° C. under atmospheric pressure by selecting an appropriate cone plate and rotation speed.

<Composition>
In the photocurable resin composition, the content of the component (A1) in the component (A) is 30 to 100% by weight. From the viewpoint of more excellent UV curability, the content of the component (A1) in the component (A) is preferably 35 to 100% by weight, more preferably 40 to 100% by weight, and 80% by weight. ˜100 wt% is more preferred, and 100 wt% is especially preferred. The remainder obtained by removing the component (A1) from the component (A) is the component (A2).

Component (A), as a main component of the photocurable resin composition, is preferably 55% by weight or more, more preferably 70% by weight or more, and 80% by weight or more in the photocurable resin composition. It is particularly preferable that

The component (B) is preferably 0.7 to 15% by weight, and 1.0 to 10% by weight in the photocurable resin composition from the viewpoint of energy ray curability and water solubility after UV curing. Is more preferable, and 1.0 to 7.0% by weight is particularly preferable.

The component (C) is preferably 0.1 to 10% by weight in the photocurable resin composition, from the viewpoint of energy ray curability and water solubility after UV curing, etc., and is 0.5 to 8.0. It is more preferably in the range of 1.0% by weight, and particularly preferably in the range of 1.0 to 7.0% by weight.

When the photocurable resin composition contains the component (D), the content of the component (D) is less than 50 parts by weight based on 100 parts by weight of the total of the components (A) and (D). It is more preferably 1 to 40 parts by weight, and particularly preferably 1 to 20 parts by weight.

(Method for producing photocurable resin composition)
The photocurable resin composition is obtained by a production method including a step of mixing the component (A), the component (B), the component (C) and an optional additional component (component (D) etc.).

[Use]
The photocurable resin composition can be used as a photocurable resin composition for temporary fixing (temporary fixing material) or a photocurable resin composition for masking (masking material). The photocurable resin composition can be applied to temporary fixing in the processing of crystal oscillators, glass lenses, plastic lenses and optical disks. Further, the photocurable resin composition can be applied to masking printed wiring boards, electronic parts, automobile parts and the like.

(Temporary fixing material)
Temporary fixing means temporarily adhering one member to the other member via the cured product of the photocurable resin composition. The cured product of the photocurable resin composition is later removed, whereby the adhesiveness between the one member and the other member due to the cured product of the photocurable resin composition is lost, and the purpose of temporary fixing is maintained. To achieve.

<Temporary fixing method>
The method of temporarily fixing a member using the photocurable resin composition for temporary fixing is as follows: a base material is attached using the photocurable resin composition for temporary fixing, or two members are overlapped on the outer peripheral portion thereof. A step of applying the photocurable resin composition, a step of curing the photocurable resin composition for temporary fixing to bond the base material, a step of temporarily fixing the base material, and a step of processing the temporarily fixed base material, Contacting the processed substrate with an aqueous cleaning agent to remove the cured photo-curable resin composition for temporary fixing.

Moreover, as a manufacturing method of the processed body using the photocurable resin composition for temporary fixing, the method including the following steps (A) or (B) and (C) to (E) can be mentioned.
(A) (a1) A step of applying a photocurable resin composition to one of the base materials to form a photocurable resin composition layer, and (a2) another step on the photocurable resin composition layer. A step of adhering one base material to obtain a laminate, or (B) after superimposing the other base material on the one base material, and then photocuring the peripheral edge portion or the superposed part thereof. A step of applying a hydrophilic resin composition to obtain a laminate,
(C) a step of irradiating the laminate obtained in step (A) or step (B) with energy rays to obtain an adhesive body,
(D) a step of processing the bonded body to obtain a rough processed body,
(E) A method of obtaining a processed product by removing the cured product of the photocurable resin composition from the rough processed product.

Process (A) is process (a1) and process (b1). Step (a1) is a step of applying the photocurable resin composition to one of the base materials to form a photocurable resin composition layer. The material of the base material is not particularly limited, but a base material made of a material that can transmit ultraviolet rays is preferable. Examples of such a material that can transmit ultraviolet rays include crystal, glass, and plastic.

The method of applying the photocurable resin composition to the substrate is not particularly limited, and a brush coating method, a screen printing method, a gravure printing, a spray method, a dipping method, a bar coater, a roll coater, a spin coater, a die coater, a dispenser. , And other known coating means. The thickness of the curable resin composition layer formed by applying the photocurable resin composition is not particularly limited, but is preferably 10 to 500 μm, and particularly preferably 30 to 350 μm.

The step (a2) is a step of bonding the other base material on the photocurable resin composition layer to obtain a laminate. The other base material is placed on the base material on which the photocurable resin composition layer is formed so as to be in contact with the curable resin layer, and the base materials are attached to each other to obtain a laminate. The step (a2) may include a step of pressure-treating the laminate.

The step (B) is a step of superimposing the other base material on the one base material, and then applying the photocurable resin composition to the outer peripheral edge portion or the superposed part to obtain a laminate. Is. In the step (B), the other base material is placed on the one base material, and one base material and the other base material are photo-cured at the peripheral edge portion or the overlapping portion thereof. It is optional as long as the photocurable composition is applied so that it is fixed by the resin composition. Examples of the method of applying the photocurable resin composition include the method described above in step (a1).

Step (C) is a step of irradiating the laminate obtained in step (A) or step (B) with energy rays to obtain an adhesive body. By irradiating the laminate with energy rays, the photocurable resin composition between the one base material and the other base material is cured, and the base materials are adhered to each other.

The energy rays are not particularly limited, and active energy rays such as visible light rays, ultraviolet rays, X-rays and electron rays can be used. The energy rays are preferably ultraviolet rays. As a light source of ultraviolet rays, a light source that emits ultraviolet rays (UV) can be used. Examples of the ultraviolet light source include a metal halide lamp, a high-pressure mercury lamp, a xenon lamp, a mercury-xenon lamp, a halogen lamp, a pulse xenon lamp, and an LED. The integrated light amount of energy rays is preferably, for example, 500 to 10,000 mJ/cm ² at 365 nm, and particularly preferably 1,000 to 8,000 mJ/cm ² .

Step (D) is a step of processing the bonded body to obtain a rough processed body. Examples of the processing include cutting, grinding, polishing, perforating, and painting the temporarily fixed adhesive body into a desired shape, which is appropriately set according to the obtained processed body.

Step (E) is a method of removing a cured product of the photocurable resin composition from the rough processed product to obtain a processed product. Examples of the method for removing the cured product of the photocurable resin composition include a method of contacting a roughened product with an aqueous cleaning agent. For example, the aqueous cleaning agent is spray-applied to the cured product of the photocurable resin composition. Examples include a method and a method of immersing the roughened product in an aqueous detergent. The cured product of the photocurable resin composition is removed from the base material by peeling or dissolving from the base material by the method of bringing the raw material and the aqueous cleaning agent into contact with each other.

Examples of the water-based detergent include water, a mixed solvent of water and a surfactant, or a mixed solvent of water and a hydrophilic organic solvent.
Surfactants include those that are nonionic, anionic, and cationic. The surfactant may be one kind or a combination of two or more kinds.
As the hydrophilic organic solvent, alcohols such as methanol, ethanol, 2-propanol and 1,2-propanediol; ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethyl cellosolve, propylene glycol monopropyl ether, propylene glycol monoisopropyl ether, Examples include glycol ethers such as butyl cellosolve, ethylene glycol monoisobutyl ether, propylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether; and cyclohexanone. The hydrophilic organic solvent may be one kind or a combination of two or more kinds.
The water-based detergent is preferably water or a mixed solvent of water and a surfactant.

The temperature of the water-based cleaning agent in the step (E) is not particularly limited and is preferably 25 to 70°C. Further, the contact time between the rough-processed body and the water-based cleaning agent in the step (E) is not particularly limited as long as it is a condition capable of removing the cured product of the photocurable resin composition from the rough-processed body, and is appropriately determined by those skilled in the art. Can be set. From the viewpoint of accelerating the dissolution of the cured product of the photocurable resin composition in water, it is preferable to vibrate the aqueous cleaning liquid with ultrasonic waves or the like. By the step (E), the purpose of temporary fixing is achieved.

Examples of the processed body obtained by the method of manufacturing the processed body using the photocurable resin composition for temporary fixing include a crystal oscillator, a glass lens, a plastic lens, and an optical disk.

(Masking material)
Masking refers to temporarily protecting a substrate or the like with a cured product of a photocurable resin composition to prevent the substrate from being scratched, attached with dirt, altered, or the like, or wiring in a film forming process. It refers to preventing the above film formation. The cured product of the photocurable resin composition is later removed to achieve the purpose of masking with the cured product of the photocurable resin composition. The photocurable resin composition can be used for temporarily masking a substrate to be masked or the like (for example, a printed wiring board or an electronic component).

<Masking method>
Examples of the method of masking the substrate include a method of temporarily covering a part or all of the surface of the substrate with a cured product of the photocurable resin composition. Depending on the method of masking the base material, when the base material is handled or a plurality of base materials are stacked, the hardened film is interposed between the base materials so that the base materials do not come into direct contact with each other and the base material is not damaged. It is possible to suppress the occurrence of breakage, adherence of foreign matter, and the like. Further, when coating an automobile part or the like, by temporarily covering the unpainted area with the cured film of the masking material, it is possible to suppress the scattering of the paint to the unpainted area.

Moreover, as a method for producing a processed body using the photocurable resin composition for masking, a method including the following steps (F) to (I) can be mentioned.
(F) a step of applying a photocurable resin composition to a substrate to form a photocurable resin composition layer,
(G) a step of irradiating the photocurable resin composition layer with energy rays to obtain a substrate masked with a cured product of the photocurable resin composition,
(H) A step of processing a base material masked with a cured product of a photocurable resin composition to obtain a roughened product, and (I) removing the cured product of the photocurable resin composition from the roughened product. Then, a process of obtaining a processed body.

The method for applying the photocurable resin composition to the substrate, the method for curing the photocurable resin composition, the method for processing the substrate, and the method for removing the cured product of the photocurable resin composition include light for temporary fixing. The method mentioned above in the manufacturing method of the processed body using a curable resin composition is mentioned.

Examples of the processed product obtained by the method for producing a processed product using the photocurable resin composition for masking include electronic parts such as printed wiring boards and displays, automobile parts and the like.

The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The values in the table are parts by weight unless otherwise specified.

(Use ingredient)
<Component (A): radical polymerization reactive monomer>
<<Component (A1): Radical polymerization reactive monomer having one (meth)acrylamide group in the molecule>>
HEAA: N-(2-hydroxyethyl)acrylamide (manufactured by KJ Chemical)
DMAA: N,N-dimethylacrylamide (manufactured by KJ Chemical)
DEAA: N,N-diethylacrylamide (manufactured by KJ Chemical)
ACMO: 4-acryloylmorpholine (made by KJ Chemical)
<<Component (A2): Other Radical Polymerization Reactive Monomer>>
FA-THFA: Tetrahydrofurfuryl acrylate (manufactured by Hitachi Chemical)
HO-250: 2-hydroxyethyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd.)
<Component (B): chain transfer agent>
MSD-100: α-methylstyrene dimer (Mitsui Chemicals)
Karenz MT PE1: Pentaerythritol tetrakis (3-mercaptobutyrate) (Showa Denko)
Karenz MT BD1: 1,4-bis(3-mercaptobutyryloxy)butane (manufactured by Showa Denko)
<Component (C): Photopolymerization Initiator>
Irgacure 1173: 2-hydroxy-2-methyl-1-phenyl-propan-1-one (manufactured by BASF)
<Component (D): further component>
<<Component (d1): Water-soluble polymer>>
PEG#1000: polyethylene glycol (manufactured by Lion) (weight average molecular weight (Mw): 1,000)
PEG#300: polyethylene glycol (manufactured by Lion) (weight average molecular weight (Mw): 300)
Klucel E: hydroxypropyl cellulose (manufactured by ASHLAND) (weight average molecular weight (Mw): 80,000)
HPC SSL: Hydroxypropyl cellulose (manufactured by Nippon Soda) (weight average molecular weight (Mw): 40,000)
Amycol 1: Starch degradation product (manufactured by Nitto Kagaku) (weight average molecular weight (Mw): 4,500)
Penone JE66: Hydroxypropyl etherified starch (manufactured by Nitto Kagaku) (weight average molecular weight (Mw): 16,000)
<<Component (d2): thixotropic agent containing an inorganic substance>>
TG308F: Fumed Silica: Cabot Specialty Chemicals

[Evaluation conditions]
(1) Viscosity The viscosity was measured at 25° C. using an E-type viscometer (RE-105U manufactured by Toki Sangyo).

(2) UV curable After applying 15 mg of a photocurable resin composition on a slide glass substrate by a dispenser method, a metal halide lamp (M06-L31 manufactured by Eye Graphics) of 3,000 mJ/cm ² UV is applied. After irradiating, it was confirmed by touching with a finger whether or not it was cured.
◯: Hardened (the surface is dry and the liquid (photo-curable resin composition) does not adhere to the finger)
×: Surface is not cured (liquid (photocurable resin composition) adheres to finger)

(3) Adhesion In the above “(2) UV curability”, the photocurable resin composition after UV curing is left standing for 24 hours and then visually observed to see if it is peeled from the slide glass substrate. It was confirmed.
○: No peeling ×: Peeling

(4) Water Solubility The test piece confirmed to have the “(2) UV curability” was put in a 2 L beaker, and 200 g of water having a temperature of 20° C. was poured. The beaker was placed in an ultrasonic cleaner (manufactured by SND, US-20PS) and subjected to ultrasonic waves of the weakest level (first step of 5 steps). Then, the test piece was taken out, and it was visually confirmed whether or not the photocurable resin composition remained.
⊚: The photocurable resin composition was completely dissolved within 3 minutes. ◯: The photocurable resin composition was completely dissolved within 3 minutes and 5 minutes. ×: The photocurable resin composition was dissolved within 5 minutes. Did not exist

[Production of photocurable resin composition]
According to the formulations shown in Tables 1 and 2, the components (A) to (D) were stirred and mixed for 30 minutes in a flask equipped with a stirrer until uniform. Among these, those containing the component (D) are heated at 60° C. and further stirred for 30 minutes to 1 hour to dissolve the solid components, thereby obtaining the liquid photocurable resin compositions of Examples and Comparative Examples. Obtained.

The results are shown in Tables 1 and 2. The values of the blending amounts of the respective components are all parts by weight.

From Table 1 and Table 2, the photocurable resin compositions of the examples were excellent in UV curability, and the cured product thereof had high solubility in water. From the results of Examples 1 to 3, it was found that the component (B) does not affect the performance even if it is added up to at least about 10% by weight in the photocurable resin composition. Comparison between Example 8 and Example 12 showed that when the content of the component (B) was high, the water solubility was better. By comparison with Examples 1, 4, 6, 7, 17, and 18, when the molecular weight of the component (D) was in the preferable range, the viscosity was high and the water solubility was better. On the other hand, since the composition of Comparative Example 1 did not contain the component (B), the obtained cured product had poor water solubility. Further, the compositions of Comparative Examples 2 and 3 did not contain the component (A1), and thus the UV curability of the compositions was poor.

Claims (5)

A photocurable resin for temporary fixing or masking, which contains a radical polymerization reactive monomer (A), a chain transfer agent (B) and a photopolymerization initiator (C) and has a viscosity of 100 to 100,000 mPa·s at 25°C. A composition, wherein the component (A) contains 30 to 100% by weight of a radical polymerization reactive monomer (A1) having one (meth)acrylamide group in the molecule, temporary fixing or masking. Photocurable resin composition for use. The photocurable resin composition according to claim 1, further comprising at least one further component (D) selected from the group consisting of a water-soluble polymer (d1) and a thixotropic agent (d2) containing an inorganic substance. .. The photocurable resin composition according to claim 2, wherein the component (D) contains a water-soluble polymer (d1), and the weight average molecular weight of the component (d1) is 300 to 100,000. The photocurable resin composition according to claim 1, wherein the component (B) is a compound having a thiol group or α-methylstyrene dimer. The photocurable resin composition according to claim 1, wherein the content of the component (B) in the photocurable resin composition is 0.7 to 15% by weight.