JP6881317B2 - A curable resin composition for a release sheet, a release sheet, a process base material using the same, and a method for protecting the base material. - Google Patents

Description

The present invention relates to a curable resin composition for a release sheet, which can obtain a release sheet having excellent adhesion and flexibility by curing. The present invention also relates to a process base material having a release sheet obtained by curing a curable resin composition for a release sheet. Furthermore, the present invention relates to a method for protecting a base material by using a release sheet obtained by curing a curable resin composition for a release sheet as a protective layer.

Conventionally, a peelable sheet has been used to protect the surface of a base material in a manufacturing process of precision parts such as electronic materials (see, for example, Japanese Patent Application Laid-Open No. 2001-247832). However, in many of these, it is necessary to cut the release sheet according to the base material, and some parts are discarded without being used. In addition, when peeled off after the heat treatment, a residue may remain on the substrate.

Further, Japanese Patent Application Laid-Open No. 2001-27971 proposes a method of improving heat resistance, printing and protecting only necessary parts by using it in a liquid state, and reducing waste. However, in this method, when the base material is plated while masked, there is a problem that the resin is dissolved in the cleaning liquid and cannot be easily peeled off.

An object of the present invention is to provide a material which can be easily applied to a substrate relatively thinly and the obtained cured film has excellent masking property, flexibility and peelability. Another object of the present invention is to provide a material capable of obtaining a release sheet in which a residue due to a residual solvent, a plasticizer or the like does not remain on the substrate after peeling from the substrate.

Another object of the present invention is to provide a process base material having a release sheet having excellent masking property, flexibility, and release property, which is obtained by curing such a material.

A further object of the present invention is to provide a method for protecting a base material by using such a release sheet as a protective layer.

The present invention has a curability for a release sheet containing (A) a polyfunctional thiol compound having a weight average molecular weight of 200 to 2000 and (B) a polyfunctional (meth) acrylate having a weight average molecular weight of 200 to 50,000. It is a resin composition, and the mass ratio ((A) / (B)) of the component (A) to the component (B) is 5 to 30, and the (C) photopolymerization initiator is used as the above (A). Monofunctional (meth) acrylate, thiophosphate diester, dithiophosphate diester, phosphonic acid, which contains 0.01 to 10 parts by mass and has an organosiloxane structure with respect to 100 parts by mass of the total mass of the component and the component (B). And contains no phosphonic acid monoester.

The curable resin composition for a release sheet contains (D) an amine compound having a weight average molecular weight of 90 to 700, 0.01 based on 100 parts by mass of the total mass of the component (A) and the component (B). It may contain up to 50 parts by mass.
Also, the curable resin composition for release sheet, in the unit weight (thiol groups) / ((meth) acryloxy groups) may be from 0.1 to 20.

Further, the present invention is a release sheet obtained by curing a curable resin composition for a release sheet.

Further, the present invention is a process base material in which a release sheet obtained by curing a curable resin composition for a release sheet is laminated on the base material.

The present invention is a method for protecting a base material by applying a curable resin composition for a release sheet to a base material and providing a release sheet obtained by curing as a protective layer.

The present invention will be described in detail below. In the present invention, "(meth) acrylate" means a generic term including both acrylate and methacrylate, and "(meth) acryloxy group" means a generic term including both an acryloxy group and a methacryloxy group. Further, in the present invention, "○○ to XX" indicating a numerical range is a concept including a lower limit value ("○○") and an upper limit value ("XX") unless otherwise specified. That is, to be exact, it means "more than XX and less than XX". Further, in the present invention, "molecular weight" is a weight average molecular weight unless otherwise specified.

The curable resin composition for a release sheet of the present invention is a curable resin composition containing the following components (A) and (B) as essential components and optionally further containing at least one of the components (C) and (D). is there.

<Polyfunctional thiol (component (A))>
The polyfunctional thiol compound (A) in the curable resin composition of the present invention is an organic compound having two or more thiol groups (-SH groups). The weight average molecular weight of the polyfunctional thiol compound is 200 to 2000, preferably 300 to 1800, and more preferably 350 to 1600. Even if the molecular weight is smaller than 200, there is no problem in terms of curability, but the polyfunctional thiol compound is highly volatile and tends to have a strong odor. On the other hand, if the molecular weight is larger than 2000, the solubility in the (B) polyfunctional (meth) acrylate resin described later may be low.

（式中のｎは２〜５の整数であり、ａは２〜１０の整数であり、Ｒ^１は炭素数２〜３０の炭化水素基（α１）、エーテル酸素（−Ｏ−）と炭素数２〜４０の炭化水素基のみからなる基（α２）、イソシアヌレート環（α３）、又はイソシアヌレート環と炭化水素基のみからなる基（α４）のいずれかである。）Examples of the polyfunctional thiol compound (A) include a polyfunctional thiol compound represented by the following general formula (1). The polyfunctional thiol compound (A) may be used alone or in combination of two or more.

(N in the formula is an integer of 2 to 5, a is an integer of 2 to 10, and R ¹ is a hydrocarbon group (α1) having 2 to 30 carbon atoms, ether oxygen (−O−) and a carbon number of carbon atoms. It is either a group consisting only of 2 to 40 hydrocarbon groups (α2), an isocyanurate ring (α3), or a group consisting only of an isocyanurate ring and a hydrocarbon group (α4).)

A compound having n = 1 in the above general formula (1) can be used without any major problem, but the high reactivity of the obtained polyfunctional thiol compound makes the storage stability of the curable resin composition containing the compound slightly stable. It tends to get worse. On the other hand, a compound in the range of n = 2 to 5 is excellent in storage stability and can be thermoset at a low temperature of about 60 ° C. in a short time. As the number of n increases, the reactivity of the obtained polyfunctional thiol compound decreases, and the curing time of the curable resin composition containing the compound during heat curing tends to increase. Therefore, among the compounds represented by the general formula (1), the compound having n = 2 is most preferable. This is because when n = 2, the reactivity of the polyfunctional thiol compound is most suitable for both storage stability and shortening of the curing time during thermosetting.

（式中のｎは２〜５の整数である。）

（式中のａは２〜１０の整数であり、Ｒ^１は炭素数２〜３０の炭化水素基（α１）、エーテル酸素（−Ｏ−）と炭素数２〜４０の炭化水素基のみからなる基（α２）、イソシアヌレート環（α３）、又はイソシアヌレート環と炭化水素基のみからなる基（α４）のいずれかである。）The polyfunctional thiol compound represented by the general formula (1) is obtained by an esterification reaction between a mercaptocarboxylic acid represented by the following general formula (2) and a polyfunctional alcohol represented by the following general formula (3). be able to.

(N in the equation is an integer of 2-5.)

(A in the formula is an integer of 2 to 10, and R ¹ is composed of only a hydrocarbon group having 2 to 30 carbon atoms (α1), ether oxygen (−O−) and a hydrocarbon group having 2 to 40 carbon atoms. It is either a group (α2), an isocyanurate ring (α3), or a group consisting only of an isocyanurate ring and a hydrocarbon group (α4).)

Among the compounds represented by the general formula (3) ^{, the compound (α1-1) in which a is 2 to 4 and R 1} is a group composed of a hydrocarbon group having 2 to 20 carbon atoms, and a is 2. ~ 6, and R ¹ is a group consisting only of ether oxygen (−O−) and a hydrocarbon group having 2 to 30 carbon atoms (α2-1), and a compound having an isocyanurate ring (α3-1). , Or a compound (α4-1) in which a is 3 and R ¹ is a group consisting only of an isocyanurate ring and a hydrocarbon group having 1 to 3 carbon atoms is preferable. This is because such a compound has high solubility in the polyfunctional epoxy resin (B).

Examples of (α1-1) include alkylenediol having 2 to 20 carbon atoms, glycerin, pentaerythritol, trimethylolpropane and the like. Examples of (α2-1) include polyethylene glycol, polypropylene glycol, dipentaerythritol and the like. Examples of (α3-1) include N, N', N ″ -trihydroxyisocyanuric acid, and examples of (α4-1) include tris (2-hydroxyethyl) isocyanurate.

（式中のｂは２〜３０の整数であり、Ｒ^２は炭素数２〜２００の炭化水素基、エーテル酸素（−Ｏ−）と炭素数２〜３００の炭化水素基のみからなる基、またはイソシアヌレート環若しくはイソシアヌレート環と炭化水素基のみからなる基であり、Ｒ^３は水素原子またはメチル基である。）<Polyfunctional (meth) acrylate ((B) component)>
The polyfunctional (meth) acrylate as the component (B) has a (meth) acryloxy group at the terminal, and a preferable example thereof is a compound represented by the following general formula (4). As the polyfunctional (meth) acrylate which is the component (B), only one kind may be used alone, or two or more kinds may be mixed and used.

(B in the formula is an integer of 2 to 30, and R ² is a hydrocarbon group having 2 to 200 carbon atoms, a group consisting only of ether oxygen (−O−) and a hydrocarbon group having 2 to 300 carbon atoms, or It is a group consisting only of an isocyanurate ring or an isocyanurate ring and a hydrocarbon group, and R ³ is a hydrogen atom or a methyl group.)

Further, as the (B) polyfunctional (meth) acrylate, a polymer type can also be preferably used. Examples of the polymer-type polyfunctional (meth) acrylate include a polymer obtained by reacting a (meth) acrylate (co) polymer having an epoxy group with a (meth) acrylate having a group that reacts with an epoxy group, and a hydroxyl group. A polymer obtained by reacting a (meth) acrylate (co) polymer having a (meth) acrylate having a group that reacts with a hydroxyl group (hereinafter referred to as a polymer derived from a hydroxyl group) and a (meth) acrylate having a carboxyl group (co). A polymer obtained by reacting a polymer with a (meth) acrylate having a group that reacts with a carboxyl group (hereinafter referred to as a polymer derived from a carboxyl group) and the like. As a polymer obtained by reacting a (meth) acrylate (co) polymer having an epoxy group with a (meth) acrylate having a group that reacts with an epoxy group, specifically, a glycidyl (meth) acrylate (co) polymer (Meta) acrylic acid adducts and the like can be mentioned. As a polymer obtained by reacting a (meth) acrylate (co) polymer having a hydroxyl group with a (meth) acrylate having a group that reacts with a hydroxyl group, specifically, a hydroxyethyl (meth) acrylate (co) polymer 2-Isocyanatoethyl (meth) acrylate adducts and the like can be mentioned. As a polymer obtained by reacting a (meth) acrylate (co) polymer having a carboxyl group with a (meth) acrylate having a group that reacts with a carboxyl group, specifically, glycidyl of a (meth) acrylic acid copolymer. (Meta) acrylate adducts and the like can be mentioned. In the present invention, the "(co) polymer" means a homopolymer (only one kind of monomer) and a copolymer (copolymerized with a plurality of kinds of monomers).

(B) The weight average molecular weight of the polyfunctional (meth) acrylate is 200 to 50,000, preferably 220 to 40,000, and more preferably 240 to 30,000. (B) When the weight average molecular weight of the polyfunctional (meth) acrylate is smaller than 200, the volatility tends to be high and the odor tends to be strong, which is not preferable. On the other hand, if the weight average molecular weight is larger than 50,000, the solubility in other components may be low, which is not preferable.

The (meth) acrylate equivalent of the (B) polyfunctional (meth) acrylate is 80 to 6000 g / mol, preferably 80 to 4500 g / mol, and more preferably 85 to 3000 g / mol. When the (meth) acrylate equivalent is smaller than 80 g / mol, the (meth) acryloxy group per unit volume becomes excessive, and a large amount of the thiol group of the (A) polyfunctional thiol and the unreacted (meth) acryloxy group remain. As a result, the toughness of the cured film made of the curable resin composition may decrease. On the other hand, when the (meth) acrylate equivalent is larger than 6000 g / mol, the concentration of the (meth) acryloxy group is remarkably low, and thus the reaction efficiency of the polyfunctional thiol with the thiol group is lowered, so that the curable resin composition is formed. There is a risk that the toughness of the cured film made of thiol will decrease.

<Photopolymerization initiator (component (C))>
The curable resin composition for a release sheet of the present invention may further contain (C) a photopolymerization initiator in addition to the above-mentioned components (A) to (B). The component (C) is blended in an amount of 0.01 to 10 parts by mass with respect to a total mass of 100 parts by mass of the component (A) and the component (B).

The photopolymerization initiator as the component (C) is added to promote the reaction between the thiol group and the (meth) acryloxy group, and the light irradiation required for curing the curable composition can be reduced. Examples of the photopolymerization initiator include a photoradical polymerization initiator, a photocationic polymerization initiator, a photoanionic polymerization initiator and the like. The photoradical polymerization initiator is preferably used when shortening the reaction time, the photocationic polymerization initiator is preferably used when reducing the curing shrinkage, and the photoanionic polymerization initiator is used in fields such as electronic circuits. It is preferable to use in.

Examples of the photoradical polymerization initiator include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, and 2-hydroxy-2-methyl-1-phenyl-propane. -1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1- {4- [4- (2) -Hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propane-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one , Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and the like.

Examples of the photocationic polymerization initiator include bis (4-tert-butylphenyl) iodonium hexafluorophosphate, bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate, cyclopropyldiphenylsulfonium tetrafluoroborate, and diphenyl. Iodonium hexafluorophosphate, diphenyliodonium hexafluoroarsenate, 2- (3,4-dimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, triphenylsulfonium tetrafluoroborate, Examples thereof include triphenylsulfonium bromide, tri-p-tolylsulfonium hexafluorophosphate, and tri-p-tolylsulfonium trifluoromethanesulfonate.

Examples of the photoanionic polymerization initiator include acetphenone o-benzoyloxime, nifedipine, and 2- (9-oxoxanthen-2-yl) propionic acid 1,5,7-triazabicyclo [4,4,0] deca-. 5-ene, 2-nitrophenylmethyl 4-methacryloyloxypiperidine-1-carboxylate, 1,2-diisopropyl-3- [bis (dimethylamino) methylene] guanidium 2- (3-benzoylphenyl) propionate, and 1, Examples thereof include 2-dicyclohexyl-4,4,5,5-tetramethylbiguanidium n-butyltriphenylborate.

<Amine compound (component (D))>
The curable resin composition for a release sheet of the present invention has (D) a weight average molecular weight of 90 to 700 in addition to the above-mentioned components (A) to (B) or (A) to (C). It can contain an amine compound. The component (D) is blended in an amount of 0.01 to 50 parts by mass with respect to a total mass of 100 parts by mass of the component (A) and the component (B).

The amine compound as the component (D) is added to promote (catalyst) the reaction between the thiol group and the (meth) acryloxy group. Specifically, by containing the component (D), the thiol group and the (meth) acryloxy group can be reacted at a low temperature, so that the curable resin composition containing the component (A) and the component (B) is contained. It is possible to cure an object at low temperature. Examples of the amine compound as the component (D) include monofunctional amines having a weight average molecular weight of 90 to 700, preferably 100 to 690, and more preferably 110 to 680, and polyamines having a plurality of amino groups. When the weight average molecular weight of the amine compound is less than 90, the volatility of the amine becomes high, which causes odor and voids. When the weight average molecular weight of the amine compound exceeds 700, the water resistance tends to decrease.

Examples of monofunctional amines include primary amines, secondary amines, and tertiary amines. Examples of polyamines include primary amines, secondary amines, tertiary amines, and complex amines. The composite amine is an amine having two or more of a primary amino group, a secondary amino group, and a tertiary amino group. Examples of such a composite amine include an imidazoline compound, an imidazole compound, an N-substituted piperazine compound, and an N, N-dimethylurea derivative. As the amine compound, only one kind may be used alone, or two or more kinds may be mixed and used.

Further, the amine compound may form a salt with an organic acid in advance in order to adjust the catalytic activity. Examples of the organic acid to be reacted with the amine compound in advance include an aliphatic carboxylic acid and an aromatic carboxylic acid.

Among the amine compounds, the highly basic imidazole compound is suitable for curing at the lowest temperature. Further, an imidazole compound coated with a phenol resin or the like can also be used.

（Ｒ^５はシアノ基、炭素数１〜１０の炭化水素基、２，３−ジアミノトリアジンで置換された炭素数１〜１０の炭化水素基、炭素数１〜４のアルコキシ基、又は水素原子であり、Ｒ^４、Ｒ^６、及びＲ^７は炭素数１〜２０の炭化水素基、炭素数１〜４のアルコキシ基、又は水素原子であり、Ｒ^４〜Ｒ^７が結合して環を形成している場合には炭素数２〜８の炭化水素基である。）The imidazole compound is a compound represented by the following formula (5).

(R ⁵ is a cyano group, a hydrocarbon group having 1 to 10 carbon atoms, a hydrocarbon group having 1 to 10 carbon atoms substituted with 2,3-diaminotriazine, an alkoxy group having 1 to 4 carbon atoms, or a hydrogen atom. Yes, R ⁴ , R ⁶ and R ⁷ are hydrocarbon groups with 1 to 20 carbon atoms, alkoxy groups with 1 to 4 carbon atoms, or hydrogen atoms, and R ^{4 to} R ⁷ combine to form a ring. If so, it is a hydrocarbon group having 2 to 8 carbon atoms.)

Specifically, 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1,2-dimethylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methyl. Imidazole, 1-benzyl-2-phenylimidazole, 2-ethyl-4-methylimidazole, 1- (2-cyanoethyl) -2-methylimidazole, 1- (2-cyanoethyl) -2-undecylimidazole, 1-( 2-Cyanoethyl) -2-ethyl-4-methylimidazole, 1- (2-cyanoethyl-2-phenylimidazole, 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole, 2,3-dihydro-1H -Pyrrolo [1,2-a] benzimidazole, 2,4-diamino-6- [2-methylimidazolyl- (1)] ethyl-1,3,5-triazine, 2,4-diamino-6- [2 '-Undecylimidazole- (1')]-ethyl-1,3,5-triazine, 2,4-diamino-6- [2'-ethyl-4'-methylimidazolyl- (1')]-ethyl- Examples thereof include 1,3,5-triazine, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole.

<Composition ratio (blending balance)>
The curable resin composition for a release sheet of the present invention has a mass ratio ((A) / (B)) of (A) polyfunctional thiol and (B) polyfunctional (meth) acrylate of 0.05 to 30. To mix. Here, "(A) / (B)" is a value obtained by dividing the mass of (A) polyfunctional thiol by the mass of (B) polyfunctional (meth) acrylate. If (A) / (B) is less than 0.05, tearing or cracking is likely to occur at the time of peeling, and if (A) / (B) exceeds 30, it becomes difficult to obtain a cured film. The optimum values of (A) / (B) differ depending on the properties required for the curable resin composition and the types of (A) polyfunctional thiol and (B) polyfunctional (meth) acrylate. Strictly speaking, the characteristics of the curable resin composition after curing are determined by the value of (number of thiol groups) / (number of (meth) acryloxy groups) (hereinafter referred to as thiol / en ratio) in the unit weight of the curable resin composition. to be influenced. For example, when the thiol / en ratio is in the range of 0.5 to 1.5, a dense crosslink is likely to be formed and a tough cured product is likely to be formed. On the other hand, when the thiol / en ratio is 0.1 or more and less than 0.5, or more than 1.5 and 2.0 or less, a flexible and sticky cured product can be obtained.

Further, the curable resin composition for a release sheet of the present invention is based on 100 parts by mass ((A) + (B)) of the total mass of (A) polyfunctional thiol and (B) polyfunctional (meth) acrylate. (C) The photopolymerization initiator is blended so as to be 0.01 to 10 parts by mass. ((A) + (B)) When the blending amount of the component (C) is less than 0.01 parts by mass with respect to 100 parts by mass, a large amount of accumulated light is required for the reaction of the thiol group and the (meth) acryloxy group to proceed. Is required, and if it exceeds 10 parts by mass, it becomes excessive for curing, which is not preferable.

When (D) an amine compound is also blended with the curable resin composition for a release sheet of the present invention, the total weight of (A) polyfunctional thiol and (B) polyfunctional (meth) acrylate ((A). ) + (B)) The amount of the (D) amine compound is 0.01 to 50 parts by mass, preferably 0.01 to 45 parts by mass with respect to 100 parts by mass. If the blending amount of the component (D) is less than 0.01 with respect to ((A) + (B)), the function as a catalyst becomes insufficient, curing is not promoted by heating, and if it exceeds 50 parts by mass. , The storage stability of the curable resin composition is lowered.

<Formation of cured film (release sheet)>
The curable resin composition for a release sheet of the present invention can form a cured film by applying it on a substrate and curing it. The curable resin composition for a release sheet of the present invention exhibits adhesion to a substrate due to a thioether group composed of a reaction of (A) polyfunctional thiol and (B) polyfunctional (meth) acrylate. Therefore, as the base material, a base material that forms a chemical bond with the thioether group (has a high chemical affinity), for example, a transition metal or an alloy thereof, a silicon compound, a phosphorus compound, a sulfur compound, a boron compound, or the like. It is excellent in the effect of improving adhesion to an inorganic base material, an organic material having an unsaturated bond (including an aromatic ring), an organic material having a hydroxyl group or a carboxyl group, or an organic material treated with plasma or UV ozone. Specifically, examples of the inorganic base material include glass, silicon, and various metals. As the organic base material, poly (meth) acrylic resin, triacetate cellulose (TAC) resin, polyester resin such as polyethylene terephthalate (PET) and polybutylene terephthalate, polycarbonate resin, polyimide resin, polyolefin such as polyethylene and polypropylene. Preferred examples thereof include based resins, polycarbonates, polyimides, ABS resins, polyvinyl alcohols, vinyl chloride resins, and polyacetals. Further, in the curable resin composition for a release sheet of the present invention, the cured film is excellent in flexibility because (A) the polyfunctional thiol has a specific hydrocarbon group. Therefore, it can be particularly preferably used for coating a flexible base material.

The curable resin composition for a release sheet of the present invention can be cured by, for example, irradiating with light. Examples of the light to be irradiated include active energy rays such as UV (ultraviolet rays) and EB (electron rays). Further, if the curable resin composition comprises a component (C), it is possible to reduce the amount of light irradiation to be usually 2,500 mJ / cm ² about need to about 100 mJ / cm ^2. When the curable resin composition contains the component (D), it can be cured only by heating at a low temperature of about 80 ° C. Further, when the curable resin composition contains the component (C) and the component (D), it can be cured through a two-step process of a curing step by irradiating light and a curing step by heating.

The curable resin composition for a release sheet of the present invention may be diluted with an organic solvent and used in order to make the reaction system uniform and facilitate coating. Examples of such an organic solvent include alcohol-based solvents, aromatic hydrocarbon-based solvents, ether-based solvents, ester-based solvents and ether ester-based solvents, ketone-based solvents, and phosphoric acid ester-based solvents. It is preferable that the amount of these organic solvents blended is less than 10,000 parts by mass with respect to 100 parts by mass of the curable resin composition. However, since the solvent is basically volatile at the time of forming the cured film, the cured film is formed. Does not have a significant effect on the physical properties of.

Further, the curable resin composition for a release sheet of the present invention may contain a viscosity modifier such as silica powder for the purpose of adjusting the viscosity. These viscosity modifiers are preferably blended in an amount of less than 300 parts by mass with respect to 100 parts by mass of the curable resin composition. If the blending amount of the viscosity modifier exceeds 300 parts by mass, a cured film may not be obtained.

Further, in the curable resin composition for a release sheet of the present invention, various additives such as those used in ordinary paints and adhesives may be added. Examples of such an additive include a surfactant for smoothing the coated surface, an aluminum salt for prolonging the usable time, and the like. These additives are preferably blended in an amount of less than 80 parts by mass with respect to 100 parts by mass of the curable resin composition. If the blending amount of these additives exceeds 80 parts by mass, a large amount of integrated light may be required for the reaction to proceed.

The curable resin composition for a release sheet of the present invention can be cured and used as a release sheet. The curable resin composition for a release sheet of the present invention includes, for example, glass, PET (polyethylene terephthalate), polyethylene, polypropylene, nylon, ITO (indium tin oxide), polyimide (PI), Si wafers, and metals in general (stainless steel, copper). , Aluminum, etc.), acrylic resin, epoxy resin, etc., can be applied and cured to form a release sheet, which can be peeled off if necessary.

The present invention relates to a process base material obtained by applying a curable resin composition for a release sheet to a base material and laminating a release sheet obtained by curing the base material. As the base material, the above-mentioned base material can be used.

The process base material of the present invention is, so to speak, an intermediate process product in the product manufacturing process. For example, at the time of manufacturing a touch panel, the curable resin composition for a release sheet of the present invention is applied to and cured on the touch panel which is the base material. A laminated body provided with a release sheet to be formed. In touch panel manufacturing, the release sheet protects the touch panel, which is the base material, from cracks, scratches, dust, dirt, and the like. Alternatively, when printing or plating the base material, the release sheet can be used to mask the non-printed portion or the non-plated portion of the base material.

Since the process base material of the present invention has a release sheet having excellent masking property, flexibility, and peelability obtained by curing the curable resin composition for a release sheet of the present invention, various base materials are used. Can be configured.

The method for protecting a base material of the present invention relates to a method for protecting a base material by applying a curable resin composition for a release sheet to the base material and providing a release sheet obtained by curing as a protective layer.

As the base material, the above-mentioned base material can be used. As the curable resin composition for a release sheet, the above-mentioned curable resin composition for a release sheet of the present invention can be used. The curable resin composition for a release sheet can be applied and cured under the above-mentioned conditions.

The method for protecting the base material of the present invention is, for example, applying a curable resin composition for a release sheet to a touch panel which is a base material and curing the touch panel to protect the touch panel from cracks, scratches, dust and dirt. Alternatively, in the method of protecting the base material of the present invention, when printing or plating the base material, a curable resin composition for a release sheet is applied and cured on the non-printed portion or the non-plated portion of the base material. , Protect the substrate from printing and plating.

The curable resin composition for a release sheet of the present invention can be easily applied to a desired thickness, and can be easily peeled off without a residue at the time of peeling. Further, since the cured film obtained by curing the composition is excellent in masking property and peelability, it can be laminated on a base material and used as a process base material. It is also possible to use the release sheet itself as a base material. By using the release sheet obtained by curing the curable resin composition for a release sheet of the present invention as a protective layer, it is possible to provide a method for protecting a base material.

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The components used in this example and the comparative example are as follows. In addition, Mw indicates the weight average molecular weight.

<Component (A): Polyfunctional thiol>
(A-1, Mw: 372)

(A-2, Mw: 399)

(A-3, Mw: 526)

(A-4, Mw: 488)

(A-5, Mw: 784)

(A-6, Mw: 416)

(A-7, Mw: 785)

(A-8, Mw: 1584)

（ｎは平均１３）<(B) component: polyfunctional (meth) acrylate>
(B-1, Mw: 5000)

(N is 13 on average)

(B-2, Mw: 246)

(B-3, Mw: 352)

(B-4, Mw: 22000)
A polymer (50 wt% methyl) in which this molar amount of methacrylic acid is added to the epoxy group of a copolymer of glycidyl methacrylate and cyclohexyl methacrylate (glycidyl methacrylate: cyclohexyl methacrylate = 3 mol: 2 mol) using the following D-3 as a catalyst. A white solid obtained by reprecipitating an isobutyl ketone solution with hexane).

(B-5, Mw: 45000)
A polymer (50 wt% methyl) in which this molar amount of methacrylic acid is added to the epoxy group of a copolymer of glycidyl methacrylate and cyclohexyl methacrylate (glycidyl methacrylate: cyclohexyl methacrylate = 3 mol: 2 mol) using the following D-3 as a catalyst. A white solid obtained by reprecipitating an isobutyl ketone solution with hexane).

<Component (C): Photopolymerization initiator>
(C-1, Mw: 204)
1-Hydroxy-cyclohexyl-phenyl-ketone

(C-2, Mw: 348)
2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide

(C-3, Mw: 407)
2- (9-oxoxanthene-2-yl) propionic acid 1,5,7-triazabicyclo [4.4.0] deca-5-ene

<Component (D): amine compound>
(D-1, Mw: 110)

(D-2, Mw: 102)
N, N-dimethyl-1,3-propanediamine

（ｎ１、ｎ２、ｎ３は１〜５の整数であり、平均が３．５である混合物）(D-3, Mw: 680)

(N1, n2, n3 are integers 1-5, with an average of 3.5)

The components (A) to (D) are mixed at the blending ratios shown in Tables 1 to 4 below, and the mixture is stirred with a spatula until uniform, and samples of the curable resin composition for a release sheet of Examples and Comparative Examples are prepared. Obtained. The following peelability, heat resistance, printability, masking property, and scratch resistance were evaluated for each of the obtained curable resin composition samples of Examples and Comparative Examples. The results are shown in Tables 1 to 4.

[Preparation of test piece 1 for evaluation of peelability and heat resistance]
Each sample of the curable resin composition for a release sheet was applied to various substrates of 10 cm × 10 cm to a thickness of 150 μm with a die coater, and UV irradiation was performed under the curing conditions shown in Tables 1 to 4, and evaluation of having a release sheet. Test piece 1 for use was obtained. The base materials used were glass (Corning, Eagle XG), PET film (Toray Co., Ltd., Lumirer U46-100), polyimide (PI) film (Toray DuPont Co., Ltd., Kapton 100H), ITO. Glass (a pattern is formed on soda glass with a length of 20 mm and a width of 50 μm of 100 Ω / □ in a line and space). For UV irradiation, a UV lamp system "Light Hammer 6" manufactured by Heleus Noble Light Fusion Ubuy Co., Ltd. was used, and an H bulb was used as the lamp bulb.

[Peelability]
After producing the evaluation test piece 1, a tape was attached to the end of the release sheet to peel off the release sheet, and then the appearance and peelability of the base material were visually confirmed and evaluated as follows.
○: Peeling (no residue)
× A: tears and cracks occur during peeling × B: poor curing

[Heat-resistant]
The glass base material of the evaluation test piece 1 is heated at 100 ° C. for 30 minutes, the tape is attached to the edge of the release sheet and peeled off, and then the appearance and peelability of the base material are visually confirmed and evaluated as follows. did.
○: Peeling (no residue)
× A: tears and cracks occur during peeling × B: poor curing

[Preparation of test piece 2 for printability evaluation]
After printing each sample of the curable resin composition for a release sheet on 10 cm × 10 cm glass (Eagle XG manufactured by Corning Inc.) using a screen printing machine at line and space = 100 μm / 100 μm, Tables 1 to 4 show. UV irradiation was carried out under the above curing conditions to obtain an evaluation test piece 2 having a release sheet. The screen printing machine used was MT-320TV manufactured by Microtech Co., Ltd.

[Printability]
The distance between the lines of the release sheet of the evaluation test piece 2 was measured using an optical microscope and evaluated as follows.
◯: Space width is 100 to 80 μm
X: Space width is less than 80 μm

[Preparation of test piece 3 for masking property evaluation]
Each sample of the curable resin composition for a release sheet is coated on a half of a 10 cm × 10 cm copper plate to a thickness of 200 μm, UV irradiation is performed under the curing conditions shown in Tables 1 to 4, and an evaluation test piece having a release sheet. I got 3.

[Masking]
The evaluation test piece 3 was immersed in a sulfuric acid aqueous solution (0.5 N) at 60 ° C. for 1 hour, and then silver-plated for 1 minute. Next, after washing the silver plating with tap water, the peelability was visually confirmed and evaluated as follows.
○: Peeling (no residue)
× A: tears and cracks occur during peeling × B: poor curing

[Preparation of test piece 4 for scratch resistance evaluation]
Each sample of the curable resin composition for a release sheet was applied to a 10 cm × 10 cm glass (Eagle XG manufactured by Corning Inc.) to a thickness of 200 μm with a die coater, and UV irradiation was performed under the curing conditions shown in Tables 1 to 4. , An evaluation test piece 4 having a release sheet was obtained.

[Scratch resistance]
A load of 300 g was applied to the release sheet of the evaluation test piece 4, a notch was made using a cutter knife, the release sheet was peeled off, and then the appearance of the base material was visually confirmed and evaluated as follows.
○: No scratches ×: With scratches

Claims (6)

(A) A polyfunctional thiol compound having a weight average molecular weight of 200 to 2000, and
(B) Polyfunctional (meth) acrylate having a weight average molecular weight of 200 to 50,000, and
The mass ratio ((A) / (B)) of the component (A) to the component (B) is 5 to 30.
(C) a photopolymerization initiator, wherein the total weight 100 parts by weight of the component (A) (B) component, Ri Na blended 0.01-10 parts by weight,
A curable resin composition for a release sheet, which does not contain a monofunctional (meth) acrylate having an organosiloxane structure, a thiophosphate diester, a dithiophosphate diester, a phosphonic acid, and a phosphonic acid monoester. (D) An amine compound having a weight average molecular weight of 90 to 700 is blended in an amount of 0.01 to 50 parts by mass with respect to 100 parts by mass of the total mass of the component (A) and the component (B). Item 2. The curable resin composition for a release sheet according to Item 1. The curable resin composition for a release sheet according to claim 1 or 2 , wherein the (number of thiol groups) / (number of (meth) acryloxi groups) in the unit weight is 0.1 to 20. A release sheet obtained by curing the curable resin composition for a release sheet according to any one of claims 1 to 3. A process base material in which a release sheet obtained by curing the curable resin composition for a release sheet according to any one of claims 1 to 3 is laminated on the base material. A method for protecting a base material by applying the curable resin composition for a release sheet according to any one of claims 1 to 3 to a base material and providing a release sheet obtained by coating and curing as a protective layer. ..