Light release additive for release sheet, resin composition for release sheet, and release sheet

Abstract

A light release additive for a release sheet, which contains an organopolysiloxane represented by formula (1). (In the formula, R1 independently represents an unsubstituted or substituted alkyl group having 1-3 carbon atoms, R2 independently represents a monovalent organic group having 1-10 carbon atoms, which has a hydroxyl group, an amino group, or a carboxyl group, and in which a heteroatom may be interposed, and R3 independently represents an unsubstituted or substituted monovalent hydrocarbon group having 4-20 carbon atoms. And a, b, and c are numbers satisfying 2 < = a < = 150, 0 < = 9b + 19c < = a, 2 < = a + b + c < = 166. )

Description

TECHNICAL FIELD

[0001] The present application relates to a light release additive for release sheet, which is a material for adjusting the release property of a release sheet, particularly a release film that can be formed to have good release property and high residual adhesion rate of a pressure-sensitive adhesive tape or the like that is peeled off, a resin composition for release sheet comprising the same, and a release sheet using the resin composition. BACKGROUND

[0002] Hitherto, by coating a release agent on the surface of a sheet-shaped substrate such as paper or plastic, a release film is formed, thereby imparting release properties to an adhesive substance or a pressure-sensitive adhesive substance.

[0003] The release sheet is used in a wide range of applications, such as cases of pressure-sensitive adhesive substances such as labels, stickers, and pressure-sensitive adhesive tapes, and cases of use in the molding process of non-pressure-sensitive adhesive substances such as ceramic green sheets and synthetic leather. Depending on the use, different properties are required.

[0004] As an example of use in the molding process of non-pressure-sensitive adhesive substances, a process paper for synthetic leather production can be cited. In the production process of synthetic leather, by curing a release agent composition on a substrate, a process paper is formed, and a polyurethane resin, a vinyl chloride resin, a polyamide resin, a polyamino acid resin, or the like is coated on the process paper and dried. By forming an adhesive layer on the dried resin and adhering a base cloth, the resin is peeled from the process paper, thereby producing synthetic leather.

[0005] In the production of synthetic leather, the process paper is used multiple times in order to improve productivity. Therefore, it is desirable that the release property (mold releasability) be little changed when repeatedly used. As a resin composition for imparting release properties to the surface of a process paper for synthetic leather, a composition comprising an acrylic resin containing a hydroxyl group, an amino resin, and a silicone resin is disclosed in Patent Literature 1 and Patent Literature 2. It is known that the release film of this resin composition has good release property and repeated durability with respect to non-pressure-sensitive adhesive substances such as polyurethane resins.

[0006] PRIOR ART DOCUMENTS

[0007] PATENT LITERATURE

[0008] Patent Literature 1: Japanese Patent No. 5282083

[0009] Patent Literature 2: Japanese Patent Application Laid-Open No. 2020-189945 SUMMARY

[0010] PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] However, the above resin composition has sufficient peelability for non-pressure-sensitive adhesive substances, but insufficient peelability for pressure-sensitive adhesive substances. In addition, the pressure-sensitive adhesive substances are generally adhered to other adherends after being peeled from the release film. Therefore, it is also required that the pressure-sensitive adhesive substances after peeling have no decrease in adhesion, i.e., have a high residual adhesion rate.

[0012] The present application has been achieved in view of the above-described actual circumstances, and aims to provide a light release additive for a release sheet, which enables good peelability for pressure-sensitive adhesive substances with a small amount of addition, and in addition, enables a release film with a high residual adhesion rate to be formed, a resin composition for a release sheet containing the same, and a release sheet using the resin composition.

[0013] Means for solving the problem

[0014] The present inventors have found that a light release additive for a release sheet containing a polyorganosiloxane having a structure represented by formula (1) solves the above-described problem, is compounded in a resin composition for a release sheet, and a release sheet having a release film formed from the composition on a substrate exhibits good peelability and has a high residual adhesion rate, and have completed the present application.

[0015] Therefore, the present application provides the following inventions.

[0016] 1. A light release additive for a release sheet, comprising an organopolysiloxane represented by the following formula (1),

[0017] [Chemical Formula 1]

[0018]

[0019] (In the formula, R 1 independently is an unsubstituted or substituted alkyl group having 1 to 3 carbon atoms, R 2 independently is a monovalent organic group having a hydroxyl group, an amino group, or a carboxyl group, a carbon atom number of 1 to 10, and a hetero atom can be intervened, R 3 independently is an unsubstituted or substituted monovalent hydrocarbon group having 4 to 20 carbon atoms. a, b, and c are numbers satisfying 2≤a≤150, 0≤9b+19c≤a, and 2≤a+b+c≤166.) 2. The light release additive for a release sheet according to 1, wherein in formula (1), b and c are 0. 3. A resin composition for a release sheet, comprising:

[0020] (A) the light release additive for a release sheet according to 1 or 2: the amount of the organopolysiloxane represented by formula (1) is 0.1 to 20 parts by mass with respect to 100 parts by mass of the total of components (B) and (C),

[0021] (B) an acrylic resin: 100 parts by mass, and

[0022] (C) melamine compound: 10 to 120 parts by mass.

[0023] 4. The resin composition for a release sheet according to 3, wherein, in formula (1), b and c are 0.

[0024] 5. The resin composition for a release sheet according to 3 or 4, wherein the (C) component is a peralkyl type methylated melamine compound.

[0025] 6. A release sheet having a base material, and a release film formed on the base material from a cured product of the resin composition for a release sheet according to any one of 3 to 5.

[0026] Effects of the Invention

[0027] The light release additive for a release sheet of the present application, by being compounded in a resin composition for a release sheet, exhibits good release properties, and enables a release film with a high residual adhesion rate to be formed. DETAILED DESCRIPTION

[0028] The present application is explained in detail below. Note that "resin composition for a release sheet" is sometimes referred to simply as "composition".

[0029] [Light release additive for a release sheet]

[0030] The light release additive for a release sheet of the present application contains an organic polysiloxane represented by the following general formula (1), and can be used alone or in combination with two or more as appropriate. Note that the order of bonding of each siloxane unit is not limited by the following (same below).

[0031] [Chemical 2]

[0032]

[0033] (In the formula, R 1 is independently an unsubstituted or substituted alkyl group having 1 to 3 carbon atoms, R 2 is independently a monovalent organic group having a hydroxyl group, an amino group, or a carboxyl group, a carbon atom number of 1 to 10, which can intervene with a hetero atom, R 3 is independently an unsubstituted or substituted monovalent hydrocarbon group having 4 to 20 carbon atoms. a, b, and c are numbers satisfying 2 ≤ a ≤ 150, 0 ≤ 9b + 19c ≤ a, and 2 ≤ a + b + c ≤ 166.)

[0034] R 1 is independently an unsubstituted or substituted alkyl group having 1 to 3 carbon atoms. For example, a methyl group, an ethyl group, a propyl group can be mentioned, and a methyl group is preferred from the aspect of ease of obtaining.

[0035] R2 independently a monovalent organic group having 1 to 10 carbon atoms which can intervene a heteroatom, is an organopolysiloxane having a functional group which can chemically bond with a resin selected from one or more of the resin contained in the release sheet resin composition and the crosslinking agent. As the heteroatom, an oxygen atom, a nitrogen atom, a sulfur atom, and the like can be exemplified. As R 2 , specifically, 2-hydroxyethyl, 3-hydroxypropyl, 2,3-dihydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, 2-hydroxybutyl, 2-(hydroxymethyl)propyl, 2-hydroxypentyl, 3-hydroxy-2,2-dimethylpropyl, 3-hydroxypentyl, 5-hydroxypentyl, 6-hydroxyhexyl, 2-hydroxyhexyl, 7-hydroxyheptyl, 8-hydroxyoctyl, 2-hydroxyethoxy, 3-[(2-hydroxyethyl)oxy]propyl, 3-[(3-hydroxypropyl)oxy]propyl, and the like hydroxyalkyl group, a polyethylene glycol group represented by -(CH2)3-(OCH2CH2) n1 OH (n1 is an integer of 1 to 3), a polypropylene glycol group represented by -(CH2)3-(OCH2CH2CH2) n2 OH (n2 is an integer of 1 to 2), 3-aminopropyl, N-2-(aminoethyl)-3-aminopropyl, carboxyoctyl, 3-glycidyloxypropyl, 2-(3,4-epoxycyclohexyl)ethyl, 3-isocyanatepropyl, and the like. Of these, from the viewpoint of curability, a hydroxyalkyl group, a polyethylene glycol group, and a polypropylene glycol group are more preferable.

[0036] R 3 independently an unsubstituted or substituted monovalent hydrocarbon group having 4 to 20 carbon atoms. It is a monovalent hydrocarbon group. Specifically, an alkyl group such as butyl, pentyl, hexyl, heptyl, octyl, and the like, a cycloalkyl group such as cyclohexyl, an aryl group such as phenyl and tolyl, and an aralkyl group such as benzyl can be exemplified. Of these, an aryl group and an aralkyl group are preferable, and a phenyl group and a benzyl group are particularly preferable. In formula (1), the proportion of R 1 , R 2 , and R 3 to the total of R 3 is preferably 5 mol% or less, and can be 0 mol%.

[0037] a, b, and c in the above formula (1) are numbers satisfying 2 ≤ a ≤ 150, 0 ≤ 9b + 19c ≤ a, and 2 ≤ a + b + c ≤ 166. a is preferably 4 ≤ a ≤ 100, more preferably 5 ≤ a ≤ 60, further preferably 6 ≤ a ≤ 40, and particularly preferably 7 ≤ a ≤ 26. If a is less than the lower limit, sometimes the releasability deteriorates, and if it exceeds the upper limit, sometimes the residual adhesion rate decreases.

[0038] b and c are numbers satisfying 0 < 9b + 19c < a, preferably 0 < 9b + 19c < 0.5a, more preferably 0 < 9b + 19c < 0.25a, particularly preferably b and c are 0. If 9b + 19c exceeds the upper limit, the peelability deteriorates.

[0039] a + b + c is 2 < a + b + c < 166, preferably 4 < a + b + c < 111, more preferably 5 < a + b + c < 66, further preferably 6 < a + b + c < 44, particularly preferably 7 < a + b + c < 28. If a + b + c is less than the lower limit, sometimes the peelability deteriorates, and if a + b + c exceeds the upper limit, sometimes the residual adhesion rate decreases.

[0040] As specific examples of the organic polysiloxane represented by the following general formula (1), there can be mentioned organic polysiloxanes represented by the following formulae, but they are not limited thereto. Note that Me in the following formulae represents a methyl group, and Ph represents a phenyl group, and they are appropriately selected in such a manner as to satisfy the stipulation of the above formula (1).

[0041] [Chemical Formula 3]

[0042]

[0043] (In the formula, 2 < d1 < 150, 0 < e1 < 7, 0 < f1 < 2, 0 < g1 < 2)

[0044] [Chemical Formula 4]

[0045]

[0046] (2 < d2 < 150, 0 < e2 < 16, 0 < f2 < 2, 0 < g2 < 2)

[0047] The method for producing the organic polysiloxane having the structure represented by formula (1) is not particularly limited, and a publicly known method can be employed.

[0048] The compounding amount of the organic polysiloxane having the structure represented by formula (1) in the light release additive for release sheet is not particularly limited, and can be appropriately selected. The light release additive (A) for release sheet can be compounded with a solvent as an optional component. By dilution with the solvent, the compatibility with the resin composition for release sheet is improved, and the dispersibility in the release sheet resin composition can be improved.

[0049] The solvent can be any compound capable of dissolving the organopolysiloxane having the structure represented by formula (1), such as, for example, aromatic hydrocarbon compounds such as toluene, xylene, and the like; aliphatic hydrocarbon compounds such as hexane, heptane, isoparaffin, and the like; alcohol compounds such as methanol, ethanol, 1-butanol, and the like; ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like; ester compounds such as ethyl acetate, butyl acetate, and the like; ether compounds such as diisopropyl ether, 1,4-dioxane, and the like. In the present application, more preferably, a solvent selected from aromatic hydrocarbon compounds such as toluene, xylene, and the like; aliphatic hydrocarbon compounds such as hexane, heptane, isoparaffin, and the like; ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like; ester compounds such as ethyl acetate, butyl acetate, and the like; ether compounds such as diisopropyl ether, 1,4-dioxane, and the like is used. These can be used alone or two or more can be appropriately combined and compounded.

[0050] The compounding amount as a compounding solvent is preferably 10 to 500 parts by mass, more preferably 20 to 300 parts by mass, relative to 100 parts by mass of (A) the organopolysiloxane having the structure represented by formula (1).

[0051] As the effect of "light peeling", in the method of the following-described Examples (for example, Example 1), the peeling strength is preferably 30 gf / 25 mm or less, more preferably 20 gf / 25 mm or less.

[0052] [Resin composition for release sheet]

[0053] The light peeling additive for release sheet of the present application is preferably used as a resin composition for release sheet. The compounding amount of the light peeling additive for release sheet as the amount of the organopolysiloxane represented by formula (1) is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 15.0 parts by mass, further preferably 0.3 to 13.0 parts by mass, relative to 100 parts by mass of the total amount of the resin and the crosslinking agent contained in the resin composition for release sheet. If it is within the above range, the peelability becomes good and the residual adhesion rate is improved.

[0054] As the resin, a resin selected from among acrylic resins, polyester resins, polyurethane resins, and epoxy resins can be used alone or two or more can be used in combination. Among these, acrylic resins and polyester resins are preferred. As the crosslinking agent, a crosslinking agent selected from among oxazoline compounds, carbodiimide compounds, isocyanate compounds, melamine compounds, and amine compounds can be used alone or two or more can be used in combination. Among these, isocyanate compounds and melamine compounds are preferred. In the resin composition for release sheet, a publicly known optional ingredient can be further compounded alone or two or more can be compounded in an appropriate amount within a range that does not impair the effects of the present application.

[0055] The resin composition for a release sheet is preferably a composition containing a light release additive for a release sheet, and more preferably a composition containing the following (A) to (C) components.

[0056] (A) Light release additive for a release sheet

[0057] (B) Acrylic resin

[0058] (C) Melamine compound

[0059] [(A) Component]

[0060] The compounding amount of the (A) light release additive for a release sheet in the resin composition for a release sheet is preferably 0.1 to 20 parts by mass, and more preferably 0.2 to 15 parts by mass, as the amount of the organopolysiloxane represented by formula (1), relative to 100 parts by mass of the total of the (B) component and the (C) component described later.

[0061] [(B) Component]

[0062] The (B) acrylic resin of the present application is a copolymer of a radical polymerizable monomer having one radical polymerizable group in one molecule, and contains one or more selected from the group consisting of acrylic acid, methacrylic acid, and derivatives thereof as an essential component. The (B) component can be used alone or two or more can be appropriately combined.

[0063] The (B) component preferably has a hydroxyl group in order to crosslink with the (C) component. The hydroxyl value of the (B) component is preferably 80 to 200 mgKOH / g, more preferably 90 to 190 mgKOH / g, and further preferably 100 to 180 mgKOH / g. If the hydroxyl value is within the above range, the releasability is good. Also, in the present application, the hydroxyl value of the acrylic resin having a hydroxyl group is a value measured according to the neutralization titration method (JIS K0070).

[0064] As the (B) component, a copolymer of a radical polymerizable monomer (B-a) having one or more hydroxyl groups in one molecule and one or more radical polymerizable groups in one molecule, and a radical polymerizable monomer (B-b) having no hydroxyl group in one molecule and one or more radical polymerizable groups in one molecule is preferably used. The polymerization ratio of the (B-a) component to the (B-b) component is adjusted according to the hydroxyl value of the (B) component.

[0065] As the (B-a) component, a radical polymerizable monomer having one or more hydroxyl groups in one molecule and one or more radical polymerizable groups in one molecule can be used alone or two or more can be used in combination, without particular limitation. As the radical polymerizable group, acryloyl group, methacryloyl group, styryl group, cinnamate group, vinyl group, allyl group, and the like can be exemplified.

[0066] Specific examples of the component (Ba) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 1,4-cyclohexanedimethanol (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and the Placcel F series (manufactured by Daicel Corporation) obtained by modifying these with caprolactone.

[0067] In addition, the radical polymerizable monomer (Bb) is not particularly limited as long as it does not have a hydroxyl group in one molecule and has one or more radical polymerizable groups in one molecule. One type can be used alone or two or more types can be used in appropriate combination. Examples of the radical polymerizable group include acryloyl, methacryloyl, styryl, cinnamate, vinyl, and allyl groups.

[0068] Component (Bb) specifically includes styrene compounds such as styrene, o-methylstyrene, p-methylstyrene, and α-methylstyrene; (meth)acrylic acid ester compounds such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, trifluoropropyl (meth)acrylate, perfluorobutylethyl (meth)acrylate, and perfluorooctylethyl (meth)acrylate; free radical polymerizable monomers containing epoxy groups such as glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate, and 3,4-epoxycyclohexylmethyl (meth)acrylate; and γ-methylacrylate. Free radical polymerizable silane compounds such as γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyldimethylmethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltributoxysilane, γ-methacryloxypropyltriisopropenoxysilane, γ-acryloxypropyltrimethoxysilane, acryloxymethyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxypropylmethyldiethoxysilane, styryltrimethoxysilane, styryltriethoxysilane, and α-methylstyryltrimethoxysilane; free radical polymerizable monomers containing polyoxyalkylene groups; glycerol (meth)acrylate, etc.

[0069] The copolymerization of the component (B-a) with the component (B-b) is carried out in the presence of a general radical polymerization initiator such as benzoyl peroxide, dicumyl peroxide, lauryl peroxide, tert-butyl 2-ethylperoxyhexanoate, azo compounds such as 2,2'-azobis(2-methylbutyronitrile), and the like, and any of solution polymerization, emulsion polymerization, suspension polymerization, and bulk polymerization can be applied. Further, the amount of the polymerization initiator used is preferably 0.01 to 10 parts by mass, more preferably 0.02 to 5 parts by mass, relative to 100 parts by mass of the total of the component (B-a) and the component (B-b).

[0070] In the present application, among these polymerization methods, solution polymerization is preferred because it is easy to adjust the weight average molecular weight of the component (B) to the optimum range. As the solvent used in this case, aromatic hydrocarbons such as benzene, toluene, and xylene; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; esters such as ethyl acetate, n-butyl acetate, and isobutyl acetate; monohydric alcohols such as ethanol, isopropanol, n-butanol, and isobutanol, and the like can be used alone or in combination of two or more as appropriate. The amount of the solvent used is preferably 10 to 900 parts by mass, more preferably 20 to 800 parts by mass, relative to 100 parts by mass of the total of the component (B-a) and the component (B-b).

[0071] In the case of copolymerizing the component (B-a) with the component (B-b) by solution polymerization, the polymerization is preferably carried out at 50 to 180°C, particularly 60 to 120°C, for 1 to 15 hours, particularly 2 to 10 hours.

[0072] The weight average molecular weight of the component (B) is preferably 5,000 to 400,000, more preferably 10,000 to 300,000, further preferably 15,000 to 250,000, particularly preferably 20,000 to 200,000. If the weight average molecular weight is within the above range, the coatability and handleability are good. Note that the weight average molecular weight is a value converted to polystyrene obtained by gel permeation chromatography (hereinafter abbreviated as "GPC") using tetrahydrofuran as the eluent.

[0073] [(C) component]

[0074] The melamine compound (C) used in the present application is a compound obtained by condensation reaction of melamine with formaldehyde, and is used as a single compound or a mixture of a plurality of compounds. The component (C) functions as a crosslinking agent that reacts with the component (A) and / or the component (B), and one or two or more kinds can be used. The component (C) can be synthesized, for example, by the publicly known method described in Japanese Patent Application No. 51-137629, and commercially available products can be used.

[0075] The (C) component can be roughly classified into a peralkyl type, a methylol type, an imino type, a methylol / imino type, depending on the functional group of the compound that becomes the main component, and can be classified into a methylated melamine compound in which all the alkoxymethyl groups are methoxymethyl groups, a n-butylated melamine compound in which all the alkoxymethyl groups are n-butoxymethyl groups, and a methylated / n-butylated melamine compound in which methoxymethyl groups and n-butoxymethyl groups are mixed, depending on the type of the alkoxymethyl group.

[0076] The (C) component is preferably a peralkyl type methylated melamine compound, a peralkyl type methylated / n-butylated melamine compound, a methylol type methylated melamine compound, a methylol type methylated / n-butylated melamine compound, more preferably a peralkyl type methylated melamine compound, a methylol type methylated melamine compound, and further preferably a peralkyl type methylated melamine compound, from the viewpoint of peelability.

[0077] As commercially available (C) components, for example, Cymel 300, Cymel 301, Cymel 303LF (all of which are peralkyl type methylated melamine compounds manufactured by Allnex Japan Co., Ltd.), Cymel 370N (all of which are methylol type methylated melamine compounds manufactured by Allnex Japan Co., Ltd.), Cymel 325, Cymel 327 (all of which are imino type methylated melamine compounds manufactured by Allnex Japan Co., Ltd.), Cymel 232, Cymel 235 (all of which are peralkyl type methylated / n-butylated melamine compounds manufactured by Allnex Japan Co., Ltd.), Cymel 251 (all of which are methylol type methylated / n-butylated melamine compounds manufactured by Allnex Japan Co., Ltd.), and the like can be listed.

[0078] The compounding amount of the (C) component is preferably 10 to 120 parts by mass, more preferably 20 to 100 parts by mass, further preferably 30 to 80 parts by mass, and particularly preferably 40 to 60 parts by mass, relative to 100 parts by mass of the (B) component. If the compounding amount of the (C) component is within the above range, the peelability becomes even better, and the residual adhesion rate is further improved.

[0079] [(D) component]

[0080] An acidic catalyst (D) can be used in the resin composition for a release sheet of the present application from the viewpoint of promoting the cross-linking reaction of the (A) component, the (B) component, and the (C) component. As the (D) component, for example, inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, boric acid, and the like, and organic acids selected from carboxylic acids such as acetic acid, monochloroacetic acid, dichloroacetic acid, butyric acid, and the like, benzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, p-phenolsulfonic acid, methanesulfonic acid, ethanesulfonic acid, and the like can be exemplified. These acidic catalysts can be used singly or two or more kinds can be used in combination as appropriate.

[0081] The amount of the (D) component when compounded can be a catalytic amount for promoting the reaction, and for example, 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, relative to 100 parts by mass of the total of the (A) to (C) components. If it is within the above range, the releasability becomes better and the residual adhesion rate is further improved.

[0082] [(E) component]

[0083] The resin composition for a release sheet of the present application can be compounded with a solvent (E). By dilution with the (E) component, practical advantages such as improvement in coatability, the thickness or finishing state of the coated film, and the state of the coated film can be obtained.

[0084] The (E) component is arbitrary as long as it is a compound that can dissolve it, and for example, aromatic hydrocarbon-based compounds such as toluene, xylene, and the like; aliphatic hydrocarbon-based compounds such as hexane, heptane, isoparaffin, and the like; alcohol-based compounds such as methanol, ethanol, 1-butanol, and the like; ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like; ester compounds such as ethyl acetate, butyl acetate, and the like; ether compounds such as diisopropyl ether, 1,4-dioxane, and the like can be exemplified. In the present application, more preferably, compounds selected from aromatic hydrocarbon-based compounds such as toluene, xylene, and the like; aliphatic hydrocarbon-based compounds such as hexane, heptane, isoparaffin, and the like; ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like; ester compounds such as ethyl acetate, butyl acetate, and the like; ether compounds such as diisopropyl ether, 1,4-dioxane, and the like are used. These can be compounded singly or two or more kinds can be used in combination as appropriate.

[0085] The amount of the (E) component when compounded is preferably 20 to 20,000 parts by mass, more preferably 50 to 10,000 parts by mass, relative to 100 parts by mass of the total of the (A) to (C) components. If it is within the above range, the coatability becomes good and the surface state of the coated film can be improved.

[0086] [(F) component]

[0087] In the resin composition for a release sheet of the present application, as a component for imparting mold releasability, an organopolysiloxane represented by the following general formula (2) can be contained, and one kind can be used singly or two or more kinds can be used in combination as appropriate.

[0088] [Chemistry 5]

[0089]

[0090] (Where R 4 are independently unsubstituted or substituted alkyl groups having 1 to 3 carbon atoms, R 5 R 6 Each of d, e, and f is independently an unsubstituted or substituted hydrocarbon group having 4 to 20 carbon atoms. d, e, and f are numbers satisfying 2≤d≤400, d≤4e+9f, 4f-e≤6d, and 2≤d+e+f≤500.

[0091] In formula (2), relative to R 4 、R 5 and R 6 The total, R 6 The ratio is preferably 10 to 60 mol%.

[0092] R 4 Independently, examples of the unsubstituted or substituted alkyl group having 1 to 3 carbon atoms include methyl, ethyl, and propyl groups. A methyl group is preferred due to its availability.

[0093] R 5 It is independently a monovalent organic group having 1 to 10 carbon atoms and having a hydroxyl group, an amino group, a carboxyl group, or an optionally intervening heteroatom. Specific examples of such a monovalent organic group include hydroxyalkyl groups such as 2-hydroxyethyl, 3-hydroxypropyl, 2,3-dihydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, 2-hydroxybutyl, 2-(hydroxymethyl)propyl, 2-hydroxypentyl, 3-hydroxy-2,2-dimethylpropyl, 3-hydroxypentyl, 5-hydroxypentyl, 6-hydroxyhexyl, 2-hydroxyhexyl, 7-hydroxyheptyl, 8-hydroxyoctyl, 2-hydroxyethoxy, 3-[(2-hydroxyethyl)oxy]propyl, and 3-[(3-hydroxypropyl)oxy]propyl, and groups represented by -(CH2)3-(OCH2CH2) n1 -OH (n1 is an integer from 1 to 3), a polyethylene glycol group represented by -(CH2)3-(OCH2CH2CH2) n2 -OH (n2 is an integer of 1 to 2) represented by a polypropylene glycol group, a 3-aminopropyl group, an N-2-(aminoethyl)-3-aminopropyl group, a carboxyoctyl group, a 3-glycidyloxypropyl group, a 2-(3,4-epoxycyclohexyl)ethyl group, a 3-isocyanatepropyl group, etc. Among these, a hydroxyalkyl group, a polyethylene glycol group, and a polypropylene glycol group are more preferred from the viewpoint of curability.

[0094] R 6independently unsubstituted or substituted hydrocarbon group having 4 to 20 carbon atoms. As the hydrocarbon group, specifically, there can be mentioned alkyl groups such as butyl, pentyl, hexyl, heptyl, octyl and the like, cycloalkyl groups such as cyclohexyl and the like, aryl groups such as phenyl and tolyl and the like, aralkyl groups such as benzyl and the like. The aryl group, aralkyl group are preferred, and the phenyl group, benzyl group are more preferred.

[0095] d, e and f in the above formula (2) are numbers satisfying 2 ≤ d ≤ 400, d ≤ 4e + 9f, 4f - e ≤ 6d, 2 ≤ d + e + f ≤ 500. d is preferably 4 ≤ d ≤ 300, more preferably 5 ≤ d ≤ 200, further preferably 6 ≤ d ≤ 150, particularly preferably 7 ≤ d ≤ 100.

[0096] e and f are numbers satisfying d ≤ 4e + 9f, and 4f - e ≤ 6d, more preferably numbers satisfying 3d ≤ 7e + 17f, and f ≤ d.

[0097] d + e + f is preferably 4 ≤ d + e + f ≤ 400, more preferably 5 ≤ d + e + f ≤ 300, further preferably 6 ≤ d + e + f ≤ 200, further preferably 7 ≤ d + e + f ≤ 100.

[0098] As specific examples of the component (F), the following examples can be mentioned, but are not limited thereto. Note that Me in the following formulae represents a methyl group, and Ph represents a phenyl group. These are appropriately selected in a manner satisfying the above formula (2).

[0099] [Chemical 6]

[0100]

[0101] (2 ≤ d3≤ 450, 1 ≤ e3≤ 300, 0 ≤ f3≤ 2, 0 ≤ g3≤ 2)

[0102] [Chemical 7]

[0103]

[0104] (2 ≤ d4≤ 400, 1 ≤ e4≤ 498, 0 ≤ f4≤ 2, 0 ≤ g4≤ 2)

[0105] As the amount of the component (F) when compounding, from the aspect of imparting mold releasability, 0.1 to 10 parts by mass, more preferably 1 to 8 parts by mass, further preferably 3 to 7 parts by mass, relative to 100 parts by mass of the component (B) is preferred.

[0106] [Other Components]

[0107] In a range not impairing the effects of the present application, the release sheet resin composition of the present application can be further added with optional components other than the above-mentioned components. As the optional components, for example, an antioxidant such as a phenol-based, quinone-based, amine-based, phosphorus-based, phosphite-based, sulfur-based, sulfide-based, and the like; a light stabilizer such as a triazole-based, benzophenone-based, and the like; a flame retardant such as a phosphate-based, halogen-based, phosphorus-based, antimony-based, and the like; a dye; a pigment; an antifoaming agent; a filler; a leveling agent; a thickening agent; a surfactant, and the like can be used. They can be used alone or two or more of them can be appropriately combined.

[0108] [Method for producing release sheet resin composition]

[0109] As for the production of the composition of the present application, it is only necessary to mix the components (A) to (C), the component (D) used as necessary, the component (E), the component (F), and the optional components, and in the case of compounding the component (D), in terms of storage stability, it is preferable to uniformly mix the components (A), (B), (C), the component (E) used as necessary, the component (F), and the optional components in advance and then add the component (D) immediately before use. The mixing method and the like are not particularly limited, and a publicly known method can be used.

[0110] [Release sheet (coated article)]

[0111] The present application provides a release sheet having a substrate and a release film formed on the surface thereof, the release film being composed of a cured product of the above-mentioned composition. The release sheet can be obtained by coating the above-mentioned composition on a substrate, heating, and forming a release film.

[0112] Specifically, for example, the above-mentioned composition is directly coated or further diluted in the above-mentioned range using a dilution solvent, and then coated on one side or both sides of a sheet-like substrate such as paper or film using a coating method such as coating using a missing corner wheel coater, a lip coater, a roll coater, a die coater, a doctor coater, a blade coater, a bar coater, a kiss coater, a gravure roll coater, a wire bar coater, screen coating, dip coating, flow coating, and the like, in an amount of 0.01 to 100 g / m 2 and then heated at 50 to 200°C for 1 to 120 seconds, thereby forming a release film on the substrate.

[0113] The coating amount is preferably 0.01 to 100 g / m 2 , more preferably 0.03 to 20 g / m 2 The temperature at the time of drying is preferably 50 to 200°C, more preferably 70 to 180°C. The time at the time of drying is preferably 1 to 120 seconds, more preferably 5 to 90 seconds. In the case where a release film is formed on both sides of a substrate, it is preferable to perform the release film formation operation for each side of the substrate.

[0114] As examples of the sheet-like base material, various coated papers such as polyethylene laminated paper, glassine paper, fine paper, kraft paper, clay-coated paper, mirror-coated paper, synthetic paper such as YUPO, polyethylene film, polypropylene film such as CPP, OPP, polyester film such as polyethylene terephthalate film, polyamide film, polyimide film, polylactic acid film, polyphenol formaldehyde film, polycarbonate film, and the like can be listed. In order to improve the adhesion of these base materials to the release film, a base material subjected to a corona treatment, an etching treatment, or a plasma treatment on the surface of the base material can be used.

[0115] Examples

[0116] The following synthesis examples, examples, and comparative examples are shown to specifically explain the present application, but the present application is not limited by the following examples.

[0117] Note that, in the formulae representing the organopolysiloxane, the order of bonding of the siloxane units is not limited by the following.

[0118] The weight average molecular weight is a value converted to polystyrene, obtained by gel permeation chromatography (hereinafter referred to as "GPC") using tetrahydrofuran as the eluent.

[0119] <Raw Materials Used>

[0120] (A) Component: organopolysiloxane represented by formula (1)

[0121] (A1) organopolysiloxane represented by the following general formula (3)

[0122] [Chem. 8]

[0123]

[0124] (In the formula, Me is a methyl group.)

[0125] (A2) organopolysiloxane represented by the following general formula (4)

[0126] [Chem. 9]

[0127]

[0128] (In the formula, Me is a methyl group.)

[0129] (A3) organopolysiloxane represented by the following general formula (5)

[0130] [Chem. 10]

[0131]

[0132] (In the formula, Me is a methyl group.)

[0133] (A4) organopolysiloxane represented by the following general formula (6)

[0134] [Chemical Formula 11]

[0135]

[0136] (In the formula, Me is a methyl group.)

[0137] (A5) An organopolysiloxane represented by the following general formula (7)

[0138] [Chemical Formula 12]

[0139]

[0140] (In the formula, Me is a methyl group.)

[0141] (B) Component

[0142] (B1) A 50 mass% butyl acetate solution of the hydroxyl group-containing acrylic resin obtained in the following Synthesis Example 1

[0143] [Synthesis Example 1]

[0144] In a glass reaction apparatus equipped with a stirrer, a thermometer, a reflux condenser, and a dropping device, butyl acetate 46.1 parts by mass was charged, heated to 90 to 100°C, and then a mixture of 2-hydroxyethyl methacrylate 26.0 parts by mass (0.20 mol), methyl methacrylate 14.0 parts by mass (0.14 mol), styrene 29.2 parts by mass (0.28 mol), t-butyl 2-ethylperoxyhexanoate 1.1 parts by mass (0.005 mol), and butyl acetate 23.1 parts by mass was dropped over 4 hours under nitrogen. Further, after polymerization at 90 to 100°C for 2 hours, t-butyl 2-ethylperoxyhexanoate 0.2 parts by mass (0.001 mol) was added, and polymerization was performed for 2 hours, to obtain a 50 mass% butyl acetate solution of the hydroxyl group-containing acrylic resin. The obtained hydroxyl group-containing acrylic resin had a hydroxyl value of 161 mgKOH / g. The weight average molecular weight in terms of polystyrene, which was obtained by GPC, was 36,000.

[0145] (B2) A 50 mass% butyl acetate solution of the hydroxyl group-containing acrylic resin obtained in the following Synthesis Example 2

[0146] [Synthesis Example 2]

[0147] In a glass reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a dropping device, 39.6 parts by mass of butyl acetate was charged, heated to 90 to 100°C, and then a mixture of 16.9 parts by mass (0.13 mol) of 2-hydroxyethyl methacrylate, 8.0 parts by mass (0.08 mol) of methyl methacrylate, 33.9 parts by mass (0.10 mol) of stearyl methacrylate, 1.1 parts by mass (0.005 mol) of t-butyl 2-ethylperoxyhexanoate, and 19.8 parts by mass of butyl acetate was dropped over 4 hours under nitrogen stream. Further, after polymerization at 90 to 100°C for 2 hours, 0.2 parts by mass (0.001 mol) of t-butyl 2-ethylperoxyhexanoate was added, and polymerization was performed for 2 hours, to obtain a 50% by mass butyl acetate solution of a hydroxyl group-containing acrylic resin. The obtained hydroxyl group-containing acrylic resin had a hydroxyl value of 112 mgKOH / g. The weight average molecular weight was 40,000 in terms of polystyrene by GPC.

[0148] (C) Component

[0149] (C1) Cymel 303LF (manufactured by Allnex Japan Co., Ltd.: all-alkyl type methylated melamine compound)

[0150] (D) Component

[0151] p-toluenesulfonic acid

[0152] (E) Component

[0153] Toluene / methyl ethyl ketone (mass ratio 1:1)

[0154] (F) Component

[0155] (F1) An organopolysiloxane represented by the following general formula (8): The order of bonding of the siloxane units is not limited by the following.

[0156] [Chemical Formula 13]

[0157]

[0158] (In the formula, Me is a methyl group, and Ph is a phenyl group.)

[0159] [Examples 1 to 9, Comparative Examples 1 and 2]

[0160] Using the above-described (A) to (F) components as raw materials, a coating composition was prepared by the following procedure.

[0161] The components (A), (B), (C), (F) were taken into a flask in the compounding ratio of Tables 1, 2, and the component (E) was compounded so that the components (A) to (C) were 5 mass% of solid content, and mixed uniformly. To the resulting solution, the component (D) was added so that it was 3 mass% relative to 100 mass parts of the total of the components (A) to (C) at an addition amount, and mixed by stirring, thereby obtaining a resin composition for release sheet. Using this composition, a release sheet (film) was produced by the method described later. Further, the compounding amount of the component (B) in the table is the pure amount excluding the solvent, since the component (B) contains butyl acetate as a solvent.

[0162] [Preparation of release film]

[0163] The resulting composition was coated on a PET film having a thickness of 38 μm using a bar coater, and heated in a hot air dryer at 120°C for 60 seconds, thereby forming a release layer. At this time, the coating amount was 0.3 g / m 2 .

[0164] [Peeling strength]

[0165] A pressure-sensitive adhesive tape (No. 31B tape, product name of Nippon Orient Co., Ltd.) having a width of 25 mm was attached to the surface of the release layer, and a load of 70 g / cm 2 was applied in a dryer at 25°C for 20 hours. Then, the No. 31B tape was pulled at an angle of 180° and a peeling speed of 0.3 m / min using a tensile testing machine (AGS-50G manufactured by Shimadzu Corporation), and the force (gf / 25 mm) required for peeling was measured. This value was taken as the peeling strength, and evaluated based on the following index.

[0166] O: Peeling strength was 20 gf / 25 mm or less

[0167] Δ: Peeling strength was more than 20 gf / 25 mm and 30 gf / 25 mm or less

[0168] X: Peeling strength was more than 30 gf / 25 mm

[0169] [Residual adhesion rate]

[0170] A pressure-sensitive adhesive tape (No. 31B tape, product name of Nippon Orient Co., Ltd.) having a width of 25 mm was attached to the surface of the release layer, and a load of 70 g / cm 2 was applied in a dryer at 25°C for 20 hours. Then, the pressure-sensitive adhesive tape was peeled from the release layer, and the tape was attached to a stainless steel plate. Next, the tape was peeled from the stainless steel plate using a tensile testing machine (AGS-50G manufactured by Shimadzu Corporation), and the peeling strength X was measured.

[0171] The adhesive tape not pasted to the release layer was pasted to the stainless steel plate, the adhesive tape was peeled from the stainless steel plate using a tensile testing machine, and the peeling strength Y was measured.

[0172] The residual adhesion rate was calculated using the formula (peeling strength X / peeling strength Y) x 100 (%), and evaluated based on the following index.

[0173] O: Residual adhesion rate is more than 95%

[0174] Δ: Residual adhesion rate is more than 85% and 95% or less

[0175] X: Residual adhesion rate is 85% or less

[0176] The results of these are shown in Tables 1 and 2. Note that the values in the tables are written as pure components for the compounding amount of the (B) component, and are not written in the tables for the (D) component.

[0177] [Table 1]

[0178]

[0179] [Table 2]

[0180]

Claims

1. A light release additive for release sheets, which contains an organopolysiloxane represented by the following formula (1), [Chemical 1] wherein R 1 independently unsubstituted or substituted alkyl group having 1 to 3 carbon atoms, R 2 independently monovalent organic group having 1 to 10 carbon atoms which can intervene hetero atom, R 3 independently unsubstituted or substituted hydrocarbon group having 4 to 20 carbon atoms, a, b and c are numbers satisfying 2≤a≤150, 0≤9b+19c≤a, 2≤a+b+c≤166.

2. The light peeling additive for release sheets according to claim 1, wherein In formula (1), b and c are 0.

3. A resin composition for release sheets, which comprises: (A) the light release additive for release sheets according to claim 1: the amount of the organopolysiloxane represented by formula (1) is 0.1 to 20 parts by mass relative to 100 parts by mass of the total of components (B) and (C), (B) an acrylic resin: 100 parts by mass, and (C) a melamine compound: 10 to 120 parts by mass.

4. The resin composition for a release sheet according to claim 3, wherein In formula (1), b and c are 0.

5. The resin composition for a release sheet according to claim 3, wherein The component (C) is a peralkylated methylated melamine compound.

6. A release sheet having: a substrate, and a release film formed on the substrate from a cured product of the resin composition for release sheets according to any one of claims 3 to 5.

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