WO2014024686A1

WO2014024686A1 - Two-pack type curable coating agent

Info

Publication number: WO2014024686A1
Application number: PCT/JP2013/070115
Authority: WO
Inventors: 雅雄木口; 亮一中井
Original assignee: ハリマ化成株式会社
Priority date: 2012-08-10
Filing date: 2013-07-24
Publication date: 2014-02-13
Also published as: KR101726201B1; TWI519613B; CN104540908B; KR20150023683A; CN104540908A; JP5921986B2; JP2014037454A; TW201418380A

Abstract

The present invention provides a two-pack type curable coating agent which is capable of forming a coating layer that has excellent transparency, hardness, scratch resistance, oil wiping-off properties and tensile elongation. A two-pack type curable coating agent of the present invention is characterized by containing: a base material which contains 100 parts by weight of an acrylic polymer that comprises a photopolymerizable group and a hydroxyl group in side chains and has a hydroxyl number of 30-350 mgKOH/g and a weight average molecular weight (Mw) of 5,000-200,000, 0.3-35 parts by weight of a silane coupling agent, 0.3-35 parts by weight of a polyether polyol, 3-70 parts by weight of a polylactone polyol and 6-500 parts by weight of a photopolymerizable polyfunctional compound that comprises two or more photopolymerizable groups in each molecule; and 3-100 parts by weight of a curing agent which contains a polyisocyanate.

Description

Two-component curable coating agent

The present invention relates to a two-component curable coating, and more particularly, to a two-component curable coating for forming a coating layer that covers the surface of a member used in various industrial fields.

Conventionally, various optical members such as a touch panel, a display, a lens, and glass have been used. In particular, touch panels are used as input devices to information terminals. Necessary information can be input to the information terminal by bringing a fingertip into contact with the front panel of the touch panel.

When the fingertip comes into contact with the optical member, oils such as aliphatic hydrocarbons existing on the surface of the fingertip tend to adhere as fingerprint marks. When the oil component adheres to the optical member, the visibility of the optical member decreases. Therefore, when the oil component adheres, (1) the adhered oil component can be easily wiped off and (2) it remains on the optical member after wiping. Both that the oil does not impair the visibility of the optical member are required. Hereinafter, the characteristics of the above (1) and (2) are collectively referred to as “oil wiping property”.

Also, if the surface of the optical member is scratched or the surface of the optical member is altered by chemicals, the visibility of the optical member is impaired, so that the surface of the optical member is given scratch resistance and chemical resistance. Is also sought.

In order to solve the above requirement, a coating layer is formed by applying a coating agent on the surface of the optical member. The coating layer is required to be transparent in order to ensure visibility. Further, the optical member on which the coating layer is formed may be formed into a desired shape, and the coating layer is not cracked at the time of forming. That is, it is also required to have excellent tensile elongation.

As such a coating agent, for example, Patent Document 1 discloses (A) colloidal silica sol, (B) an acrylic polymer having active hydrogen and a weight average molecular weight (Mw) of 5,000 to 200,000, and (C) a silane cup. A hydrophilic coating agent containing a ring agent, (D) a polylactone polyol, (F) a surfactant having active hydrogen, and (E) a curing agent in a predetermined ratio is disclosed. .

However, the coating layer formed from the hydrophilic coating agent is inferior in scratch resistance and chemical resistance, and further, the hydrophilic coating agent has a problem of low productivity because it takes time to cure. .

Patent Document 2 includes (1-A) an acrylic polyol having a predetermined hydrophilic group, (1-B) an acrylic polyol having an Mw of 50000 or less, (1-C) an organometallic compound, and a basic organosilane compound. An oil-easy-cleaning resin composition is disclosed that contains at least one selected from at least one selected from (1-D) polyisocyanate and amino resin as constituents.

However, the coating layer formed from the easy-to-oil resin composition is inferior in scratch resistance and tensile elongation, and further, the hydrophilic coating agent has a low productivity because it takes time to cure. Has a point.

Patent Document 3 discloses (A) 3 to 40% by weight of a predetermined acrylic resin, (B) 0.1 to 5% by weight of a polyoxyethylene-polyoxypropylene block copolymer, and (C) two in one molecule. A photocurable hydrophilic coating containing 55 to 95% by weight of the photopolymerizable polyfunctional compound having the above photopolymerizable group is disclosed.

However, the coating layer formed from the above-mentioned photocurable hydrophilic coating is inferior in tensile elongation, and the coating layer formed from the coating has a problem that it easily cracks due to deformation.

Patent Document 4 discloses a dealcoholization condensation reaction product of a compound (a1) having a hydroxyl group and a (meth) acryloyl group and an alkoxysilane partial condensate (b), wherein the hydroxyl equivalent of the component (a1) / ( b) A curable composition having thermosetting and active energy ray-curing properties containing a reaction product (A) having an alkoxyl group equivalent (equivalent ratio) of 0.1 to 0.4 as a curable component. Is disclosed. However, the coating layer formed from the said curable composition has the problem that it is inferior to oil wiping off.

Patent Document 5 discloses a compound obtained by reacting an acrylic resin, an isocyanate group-containing silane coupling agent having a predetermined structure, and a hydroxyl group-containing polyfunctional acrylate having a hydroxyl group and three or more acryloyl groups in the molecule, Polyfunctional acrylate having 3 or more acryloyl groups in the molecule, urethane acrylate having 2 or more acryloyl groups in the molecule, silica sol using an organic solvent as a dispersion medium, and active energy ray-curable abrasion resistance A protective coating composition is disclosed.

However, the coating layer formed from the active energy ray-curable wear-resistant coating composition has a problem that it is inferior in oil wiping property.

WO2009 / 144999 JP 2010-53286 A WO2011 / 13497 JP 2002-212248 A JP-A-6-287470

The present invention provides a two-component curable coating agent capable of forming a coating layer excellent in transparency, hardness, scratch resistance, oil wiping property and tensile elongation.

The two-component curable coating agent of the present invention comprises 100 parts by weight of an acrylic polymer having a photopolymerizable group and a hydroxyl group in the side chain, a hydroxyl value of 30 to 350 mgKOH / g, and a weight average molecular weight of 5,000 to 200,000. Coupling agent 0.3 to 35 parts by weight, polyether polyol 0.3 to 35 parts by weight, polylactone polyol 3 to 70 parts by weight, and a photopolymerizable polymer having two or more photopolymerizable groups in one molecule. It is characterized by comprising a main agent containing 6 to 500 parts by weight of a functional compound and 3 to 100 parts by weight of a curing agent containing polyisocyanate.

Further, in the above two-component curable coating agent, the main agent is a photopolymerizable group and a hydroxyl group in the side chain, a hydroxyl value of 30 to 350 mgKOH / g, and a weight average molecular weight of 5,000 to 200,000 acrylic polymer. Parts, silane coupling agent 0.3 to 35 parts by weight, polyether polyol 0.3 to 35 parts by weight, polylactone polyol 3 to 70 parts by weight, and light having two or more photopolymerizable groups in one molecule A part of the compound among 6 to 500 parts by weight of the polymerizable polyfunctional compound is reacted.

The acrylic polymer constituting the two-component curable coating agent of the present invention has a photopolymerizable group and a hydroxyl group in the side chain, and an acrylic polymer having two or more photopolymerizable groups and a hydroxyl group in the side chain. Polymers are preferred. The photopolymerizable group may have an ethylenically unsaturated double bond capable of radical polymerization with the photopolymerizable group of the photopolymerizable polyfunctional compound described later, and includes acryloyl group, methacryloyl group, styryl group, vinyl. Group, an allyl group, etc. are mentioned, An acrylolyl group and a methacryloyl group are preferable.

In the photopolymerizable group, the acrylic polymer forms a cross-linked structure by radical polymerization with the photopolymerizable group of the photopolymerizable polyfunctional compound, and a coating layer (hereinafter simply referred to as a two-component curable coating). It is possible to improve the scratch resistance by improving the hardness of the “coating layer”. Further, the acrylic polymer imparts chemical resistance such as alkali resistance and solvent resistance, and hydrophilicity to the coating layer.

An acrylic polymer having a photopolymerizable group and a hydroxyl group in the side chain (hereinafter sometimes simply referred to as “acrylic polymer”) is a radical of a monomer composition containing a radical polymerizable monomer containing a hydroxyl group or a glycidyl group, for example. A polymer can be produced by polymerization, and can be produced by adding a compound having an isocyanate group and a photopolymerizable group to a part of the hydroxyl groups of the obtained polymer. When a radically polymerizable monomer containing a glycidyl group is used, it is necessary to generate a hydroxyl group by opening the glycidyl group with an acid. Examples of the acid include maleic acid, maleic anhydride, fumaric acid, acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone monoacrylate, phthalic acid monohydroxyethyl acrylate, and acrylic acid and methacrylic acid are preferable. In addition, an acid may be used independently or 2 or more types may be used together. By using an acid having an ethylenically unsaturated double bond in the molecule, such as acrylic acid and methacrylic acid, as the acid for opening the glycidyl group, ring opening of the glycidyl group and introduction of a photopolymerizable group Can be performed simultaneously.

The amount of acid used for ring opening of the glycidyl group is preferably 0.3 to 1.5 equivalents, more preferably 0.5 to 1.2 equivalents per equivalent of glycidyl group. If the amount of acid is too small, the photopolymerizable groups in the side chain will decrease, and the hardness or chemical resistance of the coating layer obtained from the two-part curable coating may be reduced. When the amount of the acid is large, unreacted acid remains in the main agent, so that the alkali resistance or water resistance of the coating layer obtained from the two-component curable coating may be lowered.

As the polymerization method of the monomer composition, a general-purpose method is used, and examples thereof include emulsion polymerization (including suspension polymerization), solution polymerization, bulk polymerization, and the like, and emulsion polymerization and solution polymerization are preferable.

For example, an acrylic polymer is prepared by radical polymerization of a monomer composition containing a radical polymerizable monomer containing a hydroxyl group or a glycidyl group containing an alkyl (meth) acrylate and copolymerizable with an alkyl (meth) acrylate. It can be obtained by producing a polyol and adding a compound having an isocyanate group and a photopolymerizable group to a part of the hydroxyl groups of the resulting acrylic polyol. In addition, when the radically polymerizable monomer containing a glycidyl group is used, as above-mentioned, it is necessary to ring-open a glycidyl group and to produce a hydroxyl group. In the present invention, (meth) acrylate means acrylate or methacrylate.

An example of a more specific method for producing an acrylic polymer will be described. Acrylic by radical polymerization of a monomer composition containing a radical polymerizable monomer containing a hydroxyl group or a glycidyl group containing an alkyl (meth) acrylate and copolymerizable with an alkyl (meth) acrylate in the presence of a radical polymerization initiator. A polyol is produced. Next, the obtained acrylic polyol solution is supplied into a reaction vessel, and a compound having an isocyanate group and a photopolymerizable group and a metal catalyst are added into the reaction vessel. If necessary, a polymerization inhibitor such as p-methoxyphenol or hydroquinone (HQ) may be added to the reaction vessel. Then, while blowing oxygen into the reaction vessel, for example, by reacting the reaction solution for 6 to 12 hours while controlling the reaction solution to be 30 to 1500 ° C., a part of the hydroxyl groups of the acrylic polyol is obtained. A compound having an isocyanate group and a photopolymerizable group is added to produce an acrylic polymer having a photopolymerizable group and a hydroxyl group in the side chain. In addition, when the radically polymerizable monomer containing a glycidyl group is used, as above-mentioned, it is necessary to ring-open a glycidyl group and to produce a hydroxyl group.

As the radical polymerization initiator, those generally used in radical polymerization are used, such as benzoyl peroxide, lauroyl peroxide, caproyl peroxide, t-hexyl peroxyneodecanate, t-butyl peroxybivalate, etc. Organic peroxides such as 2,2-azobis-isobutyronitrile, 2,2-azobis-2,4-dimethylvaleronitrile, 2,2-azobis-4-methoxy-2,4-dimethylvaleronitrile Azo compounds such as azobis-2-methylbutyronitrile (trade name “ABN-E” manufactured by Nippon Hydrazine Kogyo Co., Ltd.), and the like are preferred. In addition, a radical polymerization initiator may be used independently or 2 or more types may be used together. The blending amount of the radical polymerization initiator is appropriately selected, but is preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the monomer composition.

Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, and heptyl (meth). Examples include acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, benzyl (meth) acrylate, and dicyclopentadienyl (meth) acrylate. In addition, alkyl (meth) acrylate may be used independently or 2 or more types may be used together.

As the alkyl (meth) acrylate, methyl (meth) acrylate and butyl (meth) acrylate are preferable, methyl (meth) acrylate is more preferable, and methyl methacrylate is particularly preferable.

In the monomer composition, when the content of the alkyl (meth) acrylate is small, the water resistance of the coating layer may be lowered, so that it is preferably 10% by weight or more, and more preferably 20% by weight or more.

In the monomer composition, if the content of the alkyl (meth) acrylate is large, the hydrophilicity of the coating layer is lowered, and the oil wiping property of the coating layer may be lowered. 80% by weight or less is more preferable.

Examples of the radical polymerizable monomer containing a hydroxyl group include an alkyl (meth) acrylate containing a hydroxyl group, acrylic acid N-hydroxymethylamide, methacrylic acid N-hydroxymethylamide, and 4-hydroxymethylcyclohexyl (meth) acrylate. An alkyl (meth) acrylate containing a hydroxyl group is preferred, and an alkyl (meth) acrylate having a hydroxyl group in the alkyl group is more preferred. Examples of the alkyl (meth) acrylate containing a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, Examples include 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, and the like. In addition, the alkyl (meth) acrylate containing a hydroxyl group may be used independently, or 2 or more types may be used together.

As the radical polymerizable monomer containing a hydroxyl group, 2-hydroxyethyl (meth) acrylate is preferable, and 2-hydroxyethyl acrylate (2-HEA) is more preferable.

As the radical polymerizable monomer containing a glycidyl group, an alkyl (meth) acrylate containing a glycidyl group is preferable. Examples of the alkyl (meth) acrylate containing a glycidyl group include glycidyl (meth) acrylate, and glycidyl methacrylate is preferable. In addition, the alkyl (meth) acrylate containing a glycidyl group may be used independently, or 2 or more types may be used together.

In the monomer composition, the content of the radically polymerizable monomer containing a hydroxyl group is preferably 60% by weight or less, more preferably 40% by weight or less, since the water resistance of the coating layer may decrease if the content is large. 30% by weight or less is particularly preferable. In the monomer composition, if the content of the radically polymerizable monomer containing a hydroxyl group is small, the hydrophilicity of the coating layer is lowered and the oil wiping property of the coating layer may be lowered. Is preferred.

In the monomer composition, if the content of the radically polymerizable monomer containing a glycidyl group is large, the water resistance of the coating layer may be lowered. . In the monomer composition, if the content of the radically polymerizable monomer containing a glycidyl group is small, the hydrophilicity of the coating layer is lowered and the oil wiping property of the coating layer may be lowered. The above is preferable, 20% by weight or more is more preferable, and 50% by weight or more is particularly preferable.

Examples of the compound having an isocyanate group and a photopolymerizable group include (meth) acryloyl groups such as 2-acryloyloxyethyl isocyanate (trade name “Karenz MOI” manufactured by Showa Denko KK) and 2-methacryloyloxyethyl isocyanate. (Meth) acryloyl isocyanate or a derivative thereof bonded to an isocyanate group via an alkylene group having 2 to 6 carbon atoms.

Examples of the derivative include (meth) acrylate having an isocyanate group masked with a blocking agent. Specific examples include 2- (O- [1'-methylpropylideneamino] carboxyamino) ethyl methacrylate (trade name “Karenz MOI-BM” manufactured by Showa Denko KK). In addition, a derivative | guide_body may be used independently or 2 or more types may be used together.

Examples of the metal catalyst include dibutyltin dilaurate, dioctyltin laurate, dioctyltin dilaurate, triphenylphosphine, and bismuth-based catalysts.

When the compound having an isocyanate group and a photopolymerizable group is added to the acrylic polyol, the isocyanate group (-) with respect to the number of moles of the hydroxyl group (-OH) in the radical polymerizable monomer containing the hydroxyl group used in the production of the acrylic polyol. The ratio of the number of moles of (NCO) (—NCO / —OH) is preferably 0.05 to 0.9, more preferably 0.1 to 0.9.

By blending in the above ratio, an acrylic polymer can be produced in a state in which the hydroxyl group remains without consuming the hydroxyl group by reaction with a compound having an isocyanate group and a photopolymerizable group. Thus, by leaving a hydroxyl group in the acrylic polymer, hydrophilicity can be imparted to the coating layer formed from the two-component curable coating agent, and the coating layer has excellent oil wiping properties. it can.

In the acrylic polymer having an alkyl (meth) acrylate component and a radically polymerizable monomer component containing a hydroxyl group or a glycidyl group, if the content of the alkyl (meth) acrylate component is small, the water resistance of the coating layer is reduced. Therefore, 10% by weight or more is preferable, and 20% by weight or more is more preferable.

In the acrylic polymer having an alkyl (meth) acrylate component and a radical polymerizable monomer component containing a hydroxyl group or a glycidyl group, if the content of the alkyl (meth) acrylate component is large, the hydrophilicity of the coating layer is lowered. Since the oil wiping property of the coating layer may be lowered, it is preferably 90% by weight or less, more preferably 80% by weight or less.

In the acrylic polymer having an alkyl (meth) acrylate component and a radical polymerizable monomer component containing a hydroxyl group, if the content of the radical polymerizable monomer component containing a hydroxyl group is large, the water resistance of the coating layer decreases. Therefore, it is preferably 60% by weight or less, more preferably 40% by weight or less, and particularly preferably 30% by weight or less.

In the acrylic polymer having an alkyl (meth) acrylate component and a radical polymerizable monomer component containing a hydroxyl group, the hydrophilicity of the coating layer decreases if the content of the radical polymerizable monomer component containing a hydroxyl group is small. And since the oil-wiping property of a coating layer may fall, 5 weight% or more is preferable.

In the acrylic polymer having an alkyl (meth) acrylate component and a radical polymerizable monomer component containing a glycidyl group, if the content of the radical polymerizable monomer component containing a glycidyl group is large, the water resistance of the coating layer is increased. 90% by weight or less is preferable, and 80% by weight or less is more preferable.

In the acrylic polymer having an alkyl (meth) acrylate component and a radical polymerizable monomer component containing a glycidyl group, if the content of the radical polymerizable monomer component containing a glycidyl group is small, the coating layer is hydrophilic. 10% by weight or more is preferable, 20% by weight or more is more preferable, and 50% by weight or more is particularly preferable.

When the hydroxyl value of the acrylic polymer is low, the portion that is thermally cured in the two-part curable coating is reduced, the tensile elongation of the coating layer is lowered, and when it is high, the chemical resistance of the coating layer is lowered, Since the appearance of the coating layer is lowered and the transparency is lowered, it is limited to 30 to 350 mgKOH / g, preferably 50 to 320 mgKOH / g, and more preferably 60 to 270 mgKOH / g. In the present invention, the hydroxyl value of the polymer refers to the hydroxyl value of the solid content.

The hydroxyl value of the acrylic polymer conforms to 4.2 method B of JIS K 1557-1: 2007 (ISO 14900: 2001) “Plastics—Polyurethane raw material polyol test method—Part 1: Determination of hydroxyl value”. The value measured in this way.

When the weight average molecular weight Mw of the acrylic polymer is low, the scratch resistance and chemical resistance of the coating layer are lowered, and when it is high, the tensile elongation of the coating layer is lowered and the appearance of the coating layer is lowered to be transparent. Therefore, it is limited to 5,000 to 200,000, preferably 6,000 to 150,000, and more preferably 10,000 to 100,000.

The weight average molecular weight Mw of the acrylic polymer is determined by measuring the molecular weight distribution of the acrylic polymer using a gel permeation chromatograph (GPC) equipped with a differential refractive index detector (RID), for example. It can be calculated from the gram (chart) using standard polystyrene as a calibration curve.

The main component of the two-component curable coating agent of the present invention contains a silane coupling agent. The silane coupling agent is an organic silicon compound represented by the following formula (1), and includes a hydroxyl group of an acrylic polymer, a hydroxyl group of a polyether polyol or a hydroxyl group-reactive functional group X having reactivity with a hydroxyl group of a polylactone polyol, An organosilicon compound having a decomposable group Y.
X _n —Si—Y _(4-n) (1)
X is a hydroxyl-reactive functional group having reactivity with a hydroxyl group of an acrylic polymer, a hydroxyl group of a polyether polyol or a hydroxyl group of a polylactone polyol, Y is a hydrolyzable group, and n is 1 to It is an integer of 3. When n is 2 or 3, a plurality of Xs may be the same or different from each other. When n is 1 or 2, a plurality of Y may be the same or different from each other.

A silane coupling agent forms a crosslinked structure with an acrylic polymer, polyether polyol or polylactone polyol in a hydroxyl-reactive functional group, and the hydrolyzable group is hydrolyzed and polycondensed. Siloxane is formed to form a cross-linked structure in a network, and the coating layer is given tensile elongation and chemical resistance.

The hydroxyl group-reactive functional group of the silane coupling agent is not particularly limited as long as it is a functional group that can react with a hydroxyl group to form a chemical bond. For example, a glycidoxyalkyl group (for example, a glycidoxypropyl group) Etc.), aminoalkyl group (eg aminopropyl group etc.), mercaptoalkyl group (eg mercaptopropyl group etc.), ureidoalkyl group (eg ureidopropyl group etc.), isocyanate alkyl group (eg isocyanatepropyl group etc.) An aminoalkyl group and an isocyanate alkyl group are preferable.

The hydrolyzable group of the silane coupling agent is not particularly limited as long as it can form a polysiloxane by hydrolysis and polycondensation. For example, hydrogen atom, halogen atom, alkoxy group, acyloxy group, ketoximate Group, amino group, amide group, acid amide group, aminooxy group, mercapto group, alkenyloxy group and the like. Alkoxy groups are preferred from the viewpoint of water resistance and chemical resistance of the resulting coating layer. As an alkoxy group, a methoxy group, an ethoxy group, a butoxy group, a propoxy group etc. are mentioned, for example, A methoxy group and an ethoxy group are preferable.

Specific examples of the silane coupling agent include, for example, glycidoxypropyltrimethoxysilane (trade name “KBM403” manufactured by Shin-Etsu Chemical Co., Ltd., product name “Silaplane S-510” manufactured by Chisso Corporation, etc.) ), Glycidoxypropyltriethoxysilane (trade name “KBE403” manufactured by Shin-Etsu Chemical Co., Ltd., product name “Z-6041” manufactured by Toray Dow Corning Co., Ltd.), etc. Agents: aminopropyltrimethoxysilane (trade name “KBM903” manufactured by Shin-Etsu Chemical Co., Ltd., product name “Z-6610” manufactured by Toray Dow Corning Co., Ltd.), N-2- (aminoethyl)- 3-Aminopropyltriethoxysilane (trade name “KBE603” manufactured by Shin-Etsu Chemical Co., Ltd.), Aminopropyltriethoxysilane (Shin-Etsu Chemical Co., Ltd. Amino group-containing silane coupling agents such as product name “KBE903”, product name “Silane Plane S330” manufactured by Chisso Corporation; mercaptopropyltrimethoxysilane (trade name “KBM803” manufactured by Shin-Etsu Chemical Co., Ltd.), Mercapto group-containing silane coupling agents such as Toray Dow Corning's trade name “Z-6062”, etc .; Ureidopropyltriethoxysilane (trade name “KBE585”, manufactured by Shin-Etsu Chemical Co., Ltd.) Urethane group-containing silane coupling agents such as Dow Corning's trade name “Z-6676”; isocyanates such as isocyanate propyltriethoxysilane (trade name “KBE9007” manufactured by Shin-Etsu Chemical Co., Ltd.) Examples thereof include a group-containing silane coupling agent. As the silane coupling agent, the stability and reactivity of the two-part curable coating agent is excellent, so that glycidoxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane Isocyanatopropyltriethoxysilane is preferable, and γ-aminopropyltriethoxysilane and N-2- (aminoethyl) -3-aminopropyltriethoxysilane are more preferable.

If the content of the silane coupling agent in the two-component curable coating is small, the tensile elongation or chemical resistance of the coating layer is reduced, and if it is high, the oil wiping property of the coating layer is reduced. The amount is limited to 0.3 to 35 parts by weight based on 100 parts by weight of the polymer, preferably 1 to 30 parts by weight, more preferably 1.5 to 20 parts by weight, and particularly preferably 1.3 to 10 parts by weight.

The main component of the two-component curable coating agent contains polyether polyol. The polyether polyol imparts hydrophilicity to the coating layer formed from the two-component curable coating agent, and improves the oil wiping property and fingerprint resistance of the coating layer.

The polyether polyol may be, for example, a low molecular weight polyol (for example, ethylene glycol, propylene glycol, glycerin, etc.) or an aromatic polyamine / aliphatic polyamine (for example, ethylenediamine, tolylenediamine, etc.) as an initiator, ethylene oxide and / or It can be obtained by addition reaction of alkylene oxide such as propylene oxide. Since the polyether polyol can improve the hydrophilicity of the coating layer formed from the two-component curable coating agent and improve the oil wiping property of the coating layer, it preferably contains an alkylene oxide. Examples of the polyether polyol include polyoxyethylene polyoxypropylene glycol ether, polyethylene polyol, polypropylene polyol, polyethylene polypropylene polyol (random or block copolymer), and polyoxyethylene polyoxypropylene glycol ether is preferable.

In addition, examples of the polyether polyol include polytetramethylene ether glycol obtained by ring-opening polymerization of tetrahydrofuran.

These polyether polyols may be used alone or in combination of two or more. The hydroxyl value of the polyether polyol is preferably 3 to 600 mgKOH / g, and more preferably 5 to 300 mgKOH / g. The hydroxyl value of the polyether polyol is a value measured in accordance with method B of JIS K1557-1 (2007).

The average number of functional groups of the polyether polyol is preferably 1 to 8, and more preferably 2 to 6. In addition, the average functional group number of polyether polyol can be calculated | required from the kind and mixture ratio of an initiator.

The weight average molecular weight of the polyether polyol is preferably 300 to 30000, more preferably 700 to 20000. The weight average molecular weight of the polyether polyol is obtained by measuring the molecular weight distribution of the polyether polyol using a gel permeation chromatograph (GPC) equipped with a differential refractive index detector (RID), for example. From (chart), standard polystyrene can be calculated as a calibration curve.

If the content of the polyether polyol contained in the main component of the two-component curable coating agent is small, the oil wiping property of the coating layer formed from the two-component curable coating agent is reduced. Since the hardness, scratch resistance and chemical resistance of the coating layer formed from the curable coating agent are lowered, the amount is limited to 0.3 to 35 parts by weight with respect to 100 parts by weight of the acrylic polymer, and 1 to 30 parts by weight. Is preferred, 1.3 to 20 parts by weight is more preferred, and 1.3 to 10 parts by weight is particularly preferred.

The main component of the two-component curable coating agent contains polylactone polyol. Excellent tensile elongation is imparted to the coating layer formed from the two-component curable coating agent by the polylactone polyol.

The polylactone polyol is obtained, for example, by ring-opening polymerization of a lactone monomer using a polyhydric alcohol as an initiator.

Specific examples of the polyhydric alcohol include, for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, and 2-methyl 1,3-propane. Diol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 2,2,4-trimethyl-1,3- Pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, glycerin, trimethylol Examples include propane, trimethylol octane, pentaerythritol and the like.

Lactone monomers include ε-caprolactone, α-methyl-ε-caprolactone, β-methyl-ε-caprolactone, γ-methyl-ε-caprolactone, β, δ-dimethyl-ε-caprolactone, 3,3,5-trimethyl -Caprolactones such as -ε-caprolactone; polyvalerolactones such as δ-valerolactone and β-methyl-δ-valerolactone; propiolactones; butyrolactones; enanthlactones; dodecanolactone. It may be a derivative of a lactone monomer.

As an example of the polylactone polyol, polycaprolactone diol is represented by the following general formula (2).
H [O (CH ₂ ) ₅ (C = O)] mO-RO [(C = O) (CH ₂ ) ₅ O] nH (2)
However, in the formula (2), R has a carbon number of 2 to 18 such as —C ₂ H ₄ —, —C ₂ H ₄ OC ₂ H ₄ —, —C (CH ₃ ) ₂ C ₂ H ₄ —, etc. Alkylene, m and n are each a positive integer, and m + n is an integer of 4 to 35.

As an example of the polylactone polyol, polycaprolactone triol is ^one in which three polyester chains having a terminal hydroxyl group are bonded to a trivalent hydrocarbon group R ¹ as shown in Formula (3).
R ¹ — (O [(C═O) — (CH ₂ ) ₅ O] pH) ₃ Formula (3)
However, in Formula (3), R ¹ is

A trivalent hydrocarbon group having 2 to 18 carbon atoms, and p is an integer of 1 to 30.

Specific examples of the polylactone polyol include polycaprolactone triol (for example, trade names “Placcel 303”, “Placcel 305”, “Placcel 308”, and “Placcel 312” manufactured by Daicel Chemical Industries, Ltd.) as commercial products. And polycaprolactone diol ("Placcel 205", "Placcel 208", "Placcel 210", and "Placcel 212" manufactured by Daicel Chemical Industries, Ltd.). As the polylactone polyol, polycaprolactone polyol is preferable. This is because, since the number of carbons connecting the polyester bonds is relatively large, excellent tensile elongation can be imparted to the coating layer formed from the two-component curable coating agent.

If the content of the polylactone polyol in the main component of the two-component curable coating agent is small, the tensile elongation of the coating layer formed from the two-component curable coating agent decreases. Since the hardness, scratch resistance and chemical resistance of the coating layer formed from the above are reduced, it is limited to 3 to 70 parts by weight with respect to 100 parts by weight of the acrylic polymer, preferably 5 to 50 parts by weight. Part by weight is more preferable, and 15 to 35 parts by weight is particularly preferable.

The main component of the two-component curable coating contains a photopolymerizable polyfunctional compound having two or more photopolymerizable groups in one molecule (hereinafter sometimes simply referred to as “photopolymerizable polyfunctional compound”). Has been. The photopolymerizable polyfunctional compound forms a cross-linked structure by radical polymerization with the photopolymerizable group of the acrylic polymer, and the coating layer formed from the two-component curable coating agent has excellent hardness, scratch resistance and resistance. Has chemical properties.

The photopolymerizable group contained in the photopolymerizable polyfunctional compound only needs to have an ethylenically unsaturated double bond capable of radical polymerization with the photopolymerizable group of the acrylic polymer, such as an acryloyl group or methacryloyl group. Group, a styryl group, a vinyl group, an allyl group, etc. are mentioned, An acrylolyl group and a methacryloyl group are preferable.

Examples of the photopolymerizable polyfunctional compound having two photopolymerizable groups in one molecule include alkylenes such as ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and neopentyl glycol di (meth) acrylate. Glycol di (meth) acrylate; polyalkylene glycol di (meth) acrylate such as diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, dicyclopentadiene di (meth) acrylate Rate, neopentyl glycol adipate di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, dicyclopentanyl di (meth) acrylate; pentaerythritol di (meta) ) Acrylate, bisphenol AEO addition diacrylate, caprolactone-modified dicyclopentenyl di (meth) acrylate, ethylene oxide-modified phosphoric acid di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate or alkylene thereof Modified oxide, divinylbenzene, butanediol-1,4-divinyl ether, cyclohexanedimethanol divinyl ether, diethylene glycol Vinyl ether, dipropylene glycol divinyl ether dipropylene glycol divinyl ether, hexanediol divinyl ether, triethylene glycol divinyl ether, phenylglycidyl ether acrylate hexamethylene diisocyanate urethane prepolymer (trade name “AH-600” manufactured by Kyoeisha Chemical Co., Ltd.) And phenylglycidyl ether acrylate toluene diisocyanate urethane prepolymer (trade name “AT-600” manufactured by Kyoeisha Chemical Co., Ltd.). In addition, a photopolymerizable polyfunctional compound may be used independently or 2 or more types may be used together.

Examples of the photopolymerizable polyfunctional compound having three photopolymerizable groups in one molecule include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, and tris. (Acryloxyethyl) isocyanurate, or their modified alkylene oxide, isocyanuric acid alkylene oxide modified tri (meth) acrylate and the like.

Examples of the photopolymerizable polyfunctional compound having four photopolymerizable groups in one molecule include ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, and their modified alkylene oxides. .

Examples of the photopolymerizable polyfunctional compound having five photopolymerizable groups in one molecule include dipentaerythritol penta (meth) acrylate or a modified alkylene oxide thereof.

Examples of the photopolymerizable polyfunctional compound having six photopolymerizable groups in one molecule include dipentaerythritol hexa (meth) acrylate and pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer (manufactured by Kyoeisha Chemical Co., Ltd.). Trade name “UA-306H”), caprolactone-modified dipentaerythritol hexa (meth) acrylate, or alkylene oxide-modified products thereof.

As the number of photopolymerizable groups contained in the photopolymerizable polyfunctional compound increases, the cross-linking of the coating layer formed from the two-component curable coating agent becomes denser and the hardness of the coating layer increases. Therefore, 3 or more are preferable, 4 or more are more preferable, and 5 or more are particularly preferable. The number of photopolymerizable groups contained in the photopolymerizable polyfunctional compound is preferably 20 or less, and more preferably 15 or less.

If the content of the photopolymerizable polyfunctional compound in the main component of the two-component curable coating is small, the hardness, scratch resistance and chemical resistance of the coating layer formed from the two-component curable coating will decrease, If the amount is too large, the tensile elongation of the coating layer formed from the two-component curable coating agent decreases, so the amount is limited to 6 to 500 parts by weight with respect to 100 parts by weight of the acrylic polymer, and preferably 3 to 100 parts by weight. 30 to 100 parts by weight is more preferable, and 30 to 85 parts by weight is particularly preferable.

The main component of the two-component curable coating agent may contain a photopolymerizable monofunctional compound having one photopolymerizable group in one molecule, if necessary. The photopolymerizable monofunctional compound is used for adjusting the viscosity of the two-component curable coating agent and improving the drying property of the two-component curable coating agent by increasing the solid content concentration.

Specific examples of the photopolymerizable monofunctional compound include aliphatic (meth) acrylate, alicyclic (meth) acrylate, aromatic (meth) acrylate, ether (meth) acrylate, vinyl monomer, (meth ) Acrylamides. In the present invention, (meth) acrylamide means acrylamide or methacrylamide.

Examples of the photopolymerizable monofunctional compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxy-3-acryloyloxypropyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) ) Acrylate, isooctyl (meth) acrylate, isomyristyl (meth) acrylate, isostearyl (meth) acrylate, isobornyl (meth) acrylate, ethoxy-diethylene glycol (meth) acrylate, 2-ethylhexyl-carbitol (meth) acrylate, neopentyl Glycol benzoate (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, ECH modified phenoxy (meth) acrylate, phenoxyethyl ( Data) acrylate, p-cumylphenol ethylene oxide-modified (meth) acrylate, vinyl pyrrolidone, vinyl caprolactam, and the like acryloyl morpholine.

If the content of the photopolymerizable monofunctional compound in the main component of the two-component curable coating is large, the reactivity of the two-component curable coating decreases and the hardness and chemical resistance of the resulting coating layer decrease. Therefore, it is preferably 150 parts by weight or less, more preferably 90 parts by weight or less, and particularly preferably 60 parts by weight or less with respect to 100 parts by weight of the acrylic polymer.

In the above description, the case where the compound contained in the main component of the two-component curable coating agent has not reacted has been described, but the compound contained in the main component of the two-component curable coating agent has partially reacted. Also good. When a part of the compound contained in the main component of the two-component curable coating agent is reacted, the above-described content of the compound means a content before the compounds react with each other.

The polyisocyanate is contained in the curing agent of the two-component curable coating agent. A two-component curable coating agent, in which the isocyanate group of the polyisocyanate reacts with the hydroxyl group of the acrylic polymer, the hydroxyl group of the polyether polyol or the hydroxyl group of the polylactone polyol to form a urethane bond, thereby introducing a crosslinked structure into the coating layer. The coating layer formed from is excellent in tensile elongation.

The polyisocyanate is not particularly limited as long as it has two or more isocyanate groups in one molecule. For example, diisocyanate, diisocyanate multimer (for example, dimer, trimer, etc.), diisocyanate modification, and the like. Since the hardness and chemical resistance of the resulting coating layer are excellent, a modified diisocyanate is preferable, and a biuret modified diisocyanate is more preferable.

The diisocyanate is not particularly limited. For example, aromatic diisocyanate (for example, tolylene diisocyanate (2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate or a mixture thereof), phenylene diisocyanate (m-phenylene diisocyanate, p-phenylene diisocyanate or a mixture thereof), 1,5-naphthalene diisocyanate, diphenylmethane diisocyanate (4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate) Nates or mixtures thereof), 4,4′-toluidine diisocyanate, etc.), araliphatic diisocyanates (eg, xylylene diisocyanate (1,3-xylylene diisocyanate) 1,4-xylylene diisocyanate or mixtures thereof), tetramethyl xylylene diisocyanate (1,3-tetramethyl xylylene diisocyanate, 1,4-tetramethyl xylylene diisocyanate or mixtures thereof), aliphatic diisocyanates ( For example, 1,3-trimethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, etc., alicyclic diisocyanates (eg, cyclohexane diisocyanate, 3-isocyanato Methyl-3,5,5-trimethylcyclohexylisocyanate (isophorodiisocyanate), methylenebis (cyclohexylisocyanate), norbornane diisocyanate, bis ( Socia isocyanatomethyl) cyclohexane) and the like. In addition, diisocyanate may be used independently or 2 or more types may be used together.

Examples of the modified diisocyanate include, for example, allophanate-modified products (for example, allophanate-modified products produced from the reaction of diisocyanate and low molecular weight polyol (for example, trimethylolpropane)), biuret-modified products (for example, diisocyanate, Modified biuret produced by reaction with water or amines), modified nurate (for example, modified nurate produced by trimerization reaction between isocyanates), modified polyol (for example, diisocyanate and low molecular weight polyol described above) Modified polyol produced by reaction with urea) modified urea (for example, modified urea produced by reaction of diisocyanate with polyamine (eg ethylenediamine, tolylenediamine, etc.), oxadiazine tri Modified products (for example, oxadiazine trione produced by reaction of diisocyanate and carbon dioxide), carbodiimide modified products (for example, carbodiimide modified products produced by decarboxylation condensation reaction of diisocyanate), uretdione modified product, uretonimine modified product The biuret modified body is preferable.

Commercially available diisocyanate modified products include, for example, trade name “Takenate D-165N” (Biuret type), trade name “Takenate D-170N” (Nurate type) manufactured by Mitsui Takeda Chemical Co., Ltd. D-178N "(allophanate type) and the like.

When the content of the curing agent in the two-component curable coating is small, the tensile elongation of the coating layer formed from the two-component curable coating is reduced, and when it is large, the coating is formed from the two-component curable coating. Since the oil wiping property of the coating layer is lowered, it is limited to 3 to 100 parts by weight with respect to 100 parts by weight of the acrylic polymer as the main agent, preferably 5 to 70 parts by weight, and more preferably 6 to 35 parts by weight.

In the main component and the curing agent of the two-component curable coating agent, an additive may be added as necessary within a range not impairing the physical properties of the two-component curable coating agent. Examples of the additive include a photopolymerization initiator, an antioxidant, a light stabilizer, a heat stabilizer, an antistatic agent, and an antifoaming agent.

Examples of photopolymerization initiators include benzoin ether photopolymerization initiators, benzophenone photopolymerization initiators, thioxanthone photopolymerization initiators, alkylphenone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, and titanocenes. And photopolymerization initiators, oxime ester photopolymerization initiators, diazophenylamine photopolymerization initiators, naphthoquinone diazosulfonic acid photopolymerization initiators, and dimethylaminobenzoic acid photopolymerization initiators. In addition, a photoinitiator may be used independently or 2 or more types may be used together.

Examples of the benzoin ether photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

Examples of the benzophenone photopolymerization initiator include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4′-methyl-diphenyl sulfide, 2,4,6-trimethylbenzophenone, and the like.

Examples of the thioxanthone photopolymerization initiator include 2-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone and the like.

Examples of the alkylphenone photopolymerization initiator include 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, and 1-hydroxy. -Cyclohexyl-phenyl-ketone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) Chill] -1- [4- (4-morpholinyl) phenyl] -1-butanone and the like.

Examples of the acylphosphine oxide photopolymerization initiator include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and the like.

Examples of titanocene photopolymerization initiators include bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium. Etc.

Examples of the oxime ester photopolymerization initiator include 1.2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (0-acetyloxime), oxy-phenyl-acetic acid 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester, oxy -Phenyl-acetic acid 2- (2-hydroxyethoxy) ethyl ester and the like.

If the content of the photopolymerization initiator is small in the main component of the two-component curable coating agent, the photo-curing of the two-component curable coating agent may not proceed sufficiently. Since the hardness of the coating layer may be lowered depending on the case, the amount is preferably 0.3 to 60 parts by weight, more preferably 1 to 35 parts by weight with respect to 100 parts by weight of the acrylic polymer.

If the content of the photopolymerization initiator in the curing agent of the two-component curable coating is small, the photo-curing of the two-component curable coating may not proceed sufficiently, and if the content is large, the photopolymerization initiator is decomposed. Since the hardness of the coating layer may be lowered depending on the product, it is preferably 0.3 to 60 parts by weight, more preferably 1 to 35 parts by weight with respect to 100 parts by weight of the acrylic polymer in the main agent used in combination with the curing agent. .

The main components of the two-component curable coating agent of the present invention are the acrylic polymer, silane coupling agent, polyether polyol, polylactone polyol, photopolymerizable polyfunctional compound, and additives added as necessary. It prepares by mixing so that it may become the content rate which carried out.

The main component of the two-component curable coating agent can also be prepared as an organic solvent solution. In this case, the solid content concentration of the main agent is preferably 10 to 90% by weight, more preferably 20 to 80% by weight.

Specifically, after pre-mixing a silane coupling agent, a polyether polyol, a polylactone polyol, a photopolymerizable polyfunctional compound, and an additive added as necessary, a pre-mixed liquid is prepared, The main component of the two-component curable coating is prepared by gradually adding the acrylic polymer to the premixed solution and mixing.

More specifically, a silane coupling agent, a polyether polyol, a polylactone polyol, a photopolymerizable polyfunctional compound, and an additive added as necessary are preliminarily mixed at 10 to 40 ° C. After preparing the mixed solution, the acrylic polymer is gradually added dropwise to the preliminary mixed solution over 30 to 60 minutes. After the dropping of the acrylic polymer into the premixed liquid is completed, the main mixture is prepared by stirring the premixed liquid at 10 to 40 ° C. for 30 to 60 minutes.

Moreover, the curing agent of the two-component curable coating agent contains polyisocyanate, but when it contains an additive other than polyisocyanate, it is prepared by adding the additive to polyisocyanate and mixing them.

As the use procedure of the two-component curable coating agent, first, the curing agent is mixed with the main component of the two-component curable coating agent, and the two-component curable coating agent is applied to the substrate. It is preferable to mix the curing agent with the main component of the two-component curable coating agent immediately before applying the two-component curable coating agent to the substrate.

The material of the base material is not particularly limited, and examples thereof include polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polycarbonate resins, polyacrylic resins, synthetic resins such as styrene resins and ABS resins, and inorganic materials such as glass. Examples include materials, metals such as stainless steel, steel, and aluminum.

As a method of applying the two-component curable coating to the substrate, for example, a dip coating method, a spray coating method, a roll coating method, a doctor blade method, a screen printing method, a coating method, a bar coater, an applicator, or the like was used. Casting etc. are mentioned.

The film thickness of the coating film of the two-component curable coating applied on the substrate is not particularly limited, but is preferably 2 to 90 μm, more preferably 5 to 50 μm.

Then, the coating film of the two-component curable coating applied on the substrate is heated and thermally cured. The thermosetting temperature of the two-component curable coating agent is preferably 60 to 180 ° C, more preferably 80 to 150 ° C. The time for heat curing of the two-component curable coating agent is preferably 1 to 30 minutes, and more preferably 1 to 10 minutes.

Next, by irradiating the heat-cured coating film with light such as ultraviolet rays, the coating film is further photocured to form a coating layer. The coating layer thus obtained is excellent in transparency, hardness, scratch resistance, oil wiping property and tensile elongation. In addition, you may form a coating layer by making the coating film of a two-component-curing-type coating agent photocure, and then thermosetting.

The coating layer is excellent in transparency. Specifically, the haze of the coating layer is preferably 1.0% or less, and more preferably 0.8% or less. The haze of the coating layer is a value measured by a haze meter in accordance with JIS K 7136 (2000).

The coating layer is excellent in hardness. Specifically, the hardness of the coating layer is preferably H or higher, more preferably 2H or higher, as pencil hardness. The pencil hardness is a value measured by a pencil hardness test in accordance with JIS K 5600-5-4 (1999).

The coating layer is excellent in oil wiping property. Specifically, the water contact angle measured by a contact angle meter is preferably 50 to 75 °, more preferably 52 to 72 °. The oleic acid contact angle is preferably 5 to 25 °, more preferably 10 to 20 °.

The coating layer has excellent adhesion to the substrate. Furthermore, since the coating layer is also excellent in oil wiping property, oil (such as fingerprints) adhering to the surface of the coating layer can be removed well with a small number of wiping operations.

The coating layer protects the surface of the optical member (for example, the surface of the image display panel, which is disposed on the outermost layer of the image display device such as a touch panel or a display that is easily touched by a human touch, and the image display panel) In order to improve the oil wiping property, the surface of the surface protective film bonded to the surface thereof, the surface of lenses such as glasses and goggles, the surface of window materials for buildings, vehicles, and instruments, etc.) are formed. The coating layer is excellent in transparency after wiping off the oil, and can ensure the visibility of the optical member. Moreover, since the coating layer is excellent in hardness, scratch resistance and chemical resistance, it can maintain excellent transparency over a long period of time, and can ensure the visibility of the optical member.

According to the two-component curable coating agent of the present invention, a coating layer excellent in transparency, hardness, scratch resistance, oil wiping property and tensile elongation can be formed.

Therefore, the two-component curable coating agent of the present invention can be favorably used for forming a coating layer for protecting the substrate surface that requires visibility.

Furthermore, the coating layer formed from the two-component curable coating agent has moderate hydrophilicity due to the hydroxyl group or ether portion. Therefore, even when oil is attached to the surface of the coating layer, water can smoothly penetrate between the surface of the coating layer and the oil to make the oil rise from the surface of the coating layer, making it easy to remove the oil. Can be removed.

The coating layer has moderate hydrophilicity, but also has moderate lipophilicity due to the carbon chain portion. Therefore, even if the oil component adhering to the coating layer is not completely removed and remains slightly on the coating layer, the oil component on the coating layer does not rise in the form of water droplets on the coating layer. On the coating layer, it becomes a thin film that is unrecognizable with the naked eye. Therefore, the oil does not cause irregular reflection of light, and the coating layer maintains excellent transparency.

Also, since the coating layer has an excellent tensile elongation, even when the substrate on which the coating layer is formed is deformed to form a desired shape, the substrate can be smoothly deformed. It will follow and there will be no cracks in the coating layer. Accordingly, it is possible to easily obtain a substrate having a surface protected by the coating layer and having a desired shape.

Furthermore, since the coating layer has excellent hardness, scratch resistance and chemical resistance, the coating layer can maintain excellent transparency and appearance over a long period of time.

The two-part curable coating agent of the present invention does not need to contain colloidal silica, and the obtained coating layer has excellent hardness, and further, tensile elongation generated by containing colloidal silica. It does not cause a decrease in Therefore, the coating layer formed from the two-component curable coating agent has excellent hardness and tensile elongation.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples.

(Synthesis of acrylic polymers A1-13)
In the reaction vessel, 233 parts by weight of methyl isobutyl ketone (MIBK) was supplied as a solvent and heated to 88 ° C. and maintained.

Contains predetermined amounts of methyl methacrylate (MMA), glycidyl methacrylate (GMA), butyl acrylate (BA), N, N-dimethylacrylamide (DMAA) and 2-hydroxyethyl acrylate (2-HEA) shown in Tables 1-3 The monomer composition was fed into and mixed with methyl isobutyl ketone in the reaction vessel.

Next, azobis-2-methylbutyronitrile (ABN-E) was mixed with the monomer composition while gradually dropping over 2 hours, and then allowed to stand for 1 hour. Further, azobis-2-methylbutyronitrile was gradually added dropwise to the monomer composition over 2 hours, and then the monomer composition was maintained at 88 ° C. over 3 hours. The total amount of azobis-2-methylbutyronitrile dropped into the monomer composition is shown in Tables 1-3.

Thereafter, the monomer composition was heated to 110 ° C. and radically polymerized for 2 hours to produce an acrylic polymer.

The weight average molecular weight Mw, number average molecular weight Mn, glass transition temperature Tg, viscosity and hydroxyl value of the obtained acrylic polymers A1 to A-13 were measured in the following manner, and the results are shown in Tables 1 to 3. The glass transition temperature Tg of the acrylic polymer was calculated by Fox's formula and shown in Tables 1 to 3. The hydroxyl value of acrylic polymers A1 to A13 is the hydroxyl value of the solid content.

(Measurement of weight average molecular weight and number average molecular weight by gel permeation chromatography)
About 0.2 mg was collected as a sample from the obtained acrylic polymer, dissolved in 10 ml of tetrahydrofuran, and measured by a gel permeation chromatograph (GPC) equipped with a differential refractive index detector (RID). The molecular weight distribution of was obtained.

Next, the weight average molecular weight and number average molecular weight of the sample were calculated from the obtained chromatogram (chart) using standard polystyrene as a calibration curve. The measurement apparatus and measurement conditions are shown below.
Data processor: Part number HLC-8220GPC (manufactured by Tosoh Corporation)
Differential refractive index detector: RI detector column built in part number HLC-8220GPC: Part number TSKgel GMH _XL (manufactured by Tosoh Corp.) 3 mobile phases: tetrahydrofuran column Flow rate: 0.5 mL / min
Injection volume: 20 μL
Measurement temperature: 40 ° C
Standard polystyrene molecular weight: 1250, 3250, 9200, 28500, 68000, 165000, 475000, 950,000, 1900000

(viscosity)
The viscosity of the obtained acrylic polymer at 25 ° C. was measured according to JIS K 5600-2-3: 1999 using a cone plate viscometer.

(Hydroxyl value)
The hydroxyl value of the obtained acrylic polymer was determined according to the method 4.2B of JIS K1557-1: 2007 (ISO 14900: 2001) “Plastics—Polyurethane raw material polyol test method—Part 1: Determination of hydroxyl value”. Measured in conformity.

(Synthesis of acrylic polymer B1-15)
A predetermined amount of methyl isobutyl ketone (MIBK) shown in Tables 4 to 6 was supplied as a solvent into the reaction vessel and heated to 80 ° C. and maintained.

Predetermined amounts of acrylic polymers A1 to 13, 2-acryloyloxyethyl isocyanate (trade name “Karenz AOI” manufactured by Showa Denko KK), acrylic acid, dibutyltin dilaurate, triphenylphosphine shown in Tables 4-6 Then, p-methoxyphenol was supplied into the reaction vessel and mixed to prepare a mixed solution.

The mixed solution is reacted at the reaction temperatures shown in Tables 4 to 6 for the reaction times shown in Tables 4 to 6, and contains acrylic polymers B1 to 15 having ethylenically unsaturated double bonds and hydroxyl groups in the side chains. An acrylic polymer solution was produced.

The weight average molecular weight Mw, number average molecular weight Mn, viscosity and hydroxyl value of the obtained acrylic polymers B1 to 15 were measured in the above manner, and the results are shown in Tables 4 to 6. Also, the ratio of the number of moles of isocyanate groups (—NCO) to the number of moles of hydroxyl groups (—OH) in 2-hydroxyethyl acrylate used in the production of acrylic polymers A1 to 6, 10 to 13 is shown in Tables 4 to 6. It was shown to. The hydroxyl value of the acrylic polymers B1 to 15 is the hydroxyl value of the solid content.

(Examples 1 to 30, Comparative Examples 1 to 17)
Predetermined amounts of γ-isocyanatopropyltriethoxysilane (trade name “KBE-9007” manufactured by Shin-Etsu Chemical Co., Ltd.) and N-2- (aminoethyl) -3-aminopropyltriethoxy shown in Tables 7 to 11 Silane (trade name “KBE-603” manufactured by Shin-Etsu Chemical Co., Ltd.), glycidoxytrimethoxysilane (trade name “KBM-403” manufactured by Shin-Etsu Chemical Co., Ltd.), polyoxyethylene polyoxypropylene glycol ether ( Trade name “Epan U105” of Daiichi Kogyo Seiyaku Co., Ltd., hydroxyl value: 19 mg KOH / g, average number of functional groups: 2, weight average molecular weight: 6400, polyoxypropylene glycol ether (manufactured by Sanyo Chemical Industries, Ltd.) Product name “SANNICS PP-1000”, hydroxyl value: 112 mgKOH / g, average number of functional groups: 2, weight average molecular weight: 000), polycaprolactone triol (trade name “Placcel 303” from Daicel Chemical Industries, Ltd.), polycaprolactone diol (trade name “Placcel 205” from Daicel Chemical Industries, Ltd.), pentaerythritol triacrylate hexamethylene diisocyanate Urethane prepolymer (trade name “UA-306H” from Kyoeisha Chemical Co., Ltd.), phenylglycidyl ether acrylate hexamethylene diisocyanate prepolymer (trade name “AH-600” from Kyoeisha Chemical Co., Ltd.), colloidal silica (Nissan Chemical Industries) A premixed solution was prepared by uniformly mixing a product name “MIBK-ST” of Co., Ltd.) and methyl isobutyl ketone.Acrylic polymer solution containing acrylic polymers B1 to 15 was added to the acrylic polymer B1. ~ 15 Was gradually added dropwise over 10 minutes so that the amount (solid content) was as shown in Tables 7 to 11. After completion of the dropwise addition of the acrylic polymer solution to the premixed solution, the premixed solution was added at 30 ° C. for 30 to 30 minutes. The main component of the two-component curable coating was prepared by stirring for 60 minutes, and then a predetermined amount of 2-hydroxy-2-methyl-1 shown in Tables 7 to 11 was added to the main component of the two-component curable coating. -Phenyl-propan-1-one (product name “DAROCUR 1173” manufactured by BASF) was added, and the solid content concentration of the main component of the two-pack curable coating was 30% by weight.

A biuret-modified product of hexamethylene diisocyanate with a predetermined amount shown in Tables 7 to 11 (trade name “Takenate D-165N” of Mitsui Takeda Chemical Co., Ltd.) was used as a curing agent for a two-component curing type coating agent.

A biuret-modified product of a predetermined amount of hexamethylene diisocyanate shown in Tables 7 to 11 was added as a curing agent to the main component of the two-component curable coating agent. Immediately after the addition, the two-component curable coating was coated with a bar coater No. 10 was applied onto a polyethylene terephthalate (PET) film.

Thereafter, the two-component curable coating is heated at 80 ° C. for 3 minutes to remove the solvent and thermally cure the two-component curable coating, and then the resulting thermosetting coating is coated with a high-pressure mercury lamp (120 W). / Cm) was used to irradiate ultraviolet rays at 500 mJ / cm ² to further photocure the thermosetting film to form a coating layer. In Comparative Example 12, the two-component curable coating was heated at 80 ° C. for 20 minutes to remove the solvent and thermally cure the two-component curable coating.

Measure the haze, pencil hardness, adhesion, oil removal, scratch resistance, alkali resistance, solvent resistance, tensile elongation, water contact angle and oleic acid contact angle of the resulting coating layer as follows. The results are shown in Tables 7-11.

(Haze)
The haze of the coating layer was measured using a haze meter (trade name “NDH5000” of Nippon Denshoku Industries Co., Ltd.) in accordance with the test method of “How to determine haze of plastic / transparent material” of JIS K 7136. . In addition, the haze is excellent in transparency as the value is small.

(Pencil hardness)
The pencil hardness of the coating layer was measured by conducting a pencil hardness test in accordance with JIS K 5600-5-4: 1999. In the pencil hardness test, B, HB, F, and H are arranged in order from the lower hardness to the higher hardness. The pencil hardness indicates that the greater the number attached before “H”, the higher the hardness, and the greater the number attached before “B”, the lower the hardness.

(Adhesion)
The adhesion of the coating layer was measured according to JIS K 5600-5-6: 1999. Specifically, incisions reaching the polyethylene terephthalate film were formed in a lattice shape in the coating layer. The coating layer was divided into 100 pieces by grid-like cuts. The divided piece had a planar square shape with one side of 1.0 mm. An adhesive tape (trade name “Nichiban Tape No. 1” manufactured by Nichiban Co., Ltd.) was attached to the whole of the divided pieces. And the stuck adhesive tape was peeled from the polyethylene terephthalate film, and the number of the division pieces which remained on the polyethylene terephthalate film was counted. The adhesion was evaluated as (number of divided pieces remaining on the polyethylene terephthalate film / number of divided pieces formed on the polyethylene terephthalate film). In addition, it shows that it is excellent in adhesiveness, so that there are many division pieces which remain | survived on the polyethylene terephthalate film.

(Oil removal)
0.1 g of normal hexadecane was dropped on the surface of the coating layer. Then, normal hexadecane adhering to the surface of the coating layer was wiped 10 times with a cellulose nonwoven fabric (trade name “Bencot M-3” manufactured by Asahi Kasei Co., Ltd.) under a load of 300 g.

Next, the haze (turbidity) of the coating layer surface before and after wiping was measured using a haze meter (trade name “NDH5000” manufactured by Nippon Denshoku Industries Co., Ltd.). And haze difference (DELTA) E of the coating layer before wiping off and after wiping off was computed. Note that the smaller the value of ΔE, the better the oil wiping property such as fingerprint marks caused by sebum.

(Scratch resistance)
The surface of the coating layer, steel wool (Bonsuta Sales Co., Ltd. No. # 0000) and along the surface of the coating layer while applying a load of 1 cm ² per 300g was 50 back and forth. Using a haze meter (trade name “NDH5000” manufactured by Nippon Denshoku Industries Co., Ltd.), the haze (turbidity) of the coating layer surface before and after the test was measured. And the difference (DELTA) E of the haze of the coating layer before a test and after a test was computed. The smaller the value of ΔE, the better the scratch resistance.

(Alkali resistance)
The polyethylene terephthalate film on which the coating layer was formed was immersed in a 5 wt% aqueous sodium hydroxide solution at 40 ° C. ± 2 ° C. for 3 days. Using a haze meter (trade name “NDH5000” manufactured by Nippon Denshoku Industries Co., Ltd.), haze (turbidity) of the coating layer surface before and after immersion was measured. And the difference (DELTA) E of the haze of the coating layer before immersion and after immersion was computed. In addition, alkali resistance is so favorable that the value of (DELTA) E is small.

(Solvent resistance)
Acetone was dropped onto the surface of the coating layer, and then a rubbing test was performed 100 times with a load of 100 g. Using a haze meter (trade name “NDH5000” manufactured by Nippon Denshoku Industries Co., Ltd.), the haze (turbidity) of the coating layer surface before and after the test was measured. And the difference (DELTA) E of the haze of the coating layer before a test and after a test was computed. The smaller the value of ΔE, the better the solvent resistance.

(Tensile elongation)
After adding as a curing agent to the main component of the two-part curable coating, immediately after adding the two-part curable coating, the bar coater No. 10 was applied onto a polyethylene terephthalate (PET) film having a thickness of 188 μm.

Thereafter, the two-component curable coating is heated at 80 ° C. for 3 minutes to remove the solvent and thermally cure the two-component curable coating, and then the resulting thermosetting coating is coated with a high-pressure mercury lamp (120 W). / cm) 500mJ / cm ² was irradiated with ultraviolet light to further photocuring a thermosetting coating in it to form a coating layer used.

The tensile elongation of the obtained coating layer was measured in accordance with a plastic-tensile property test method (JIS K7127). The measurement conditions were as follows: a test piece having a thickness of 30 μm, a width of 25 mm, and a length of 115 mm was used. The test piece was pulled under the conditions of a pulling speed of 100 mm / min, a distance between chucks of 80 mm, a distance between marked lines of 25 mm, and a temperature of 23 ° C. The length L of the test piece at the time of breaking was measured, and the tensile elongation was calculated based on the following formula.
Tensile elongation (%) = 100 × (L-115)

(Water contact angle)
A 0.4 microliter water droplet was dropped on the surface of the coating layer, and the contact angle was measured with a contact angle meter (trade name “Drop Master 500” manufactured by Kyowa Interface Science Co., Ltd.). In addition, it shows that it is excellent in the oil wiping off property, so that a water contact angle is low.

(Oleic acid contact angle)
0.4 microliters of oleic acid was dropped on the surface of the coating layer, and the contact angle was measured with a contact angle meter (trade name “Drop Master 500” manufactured by Kyowa Interface Science Co., Ltd.). In addition, it shows that it is excellent in the oil wiping off property, so that a water contact angle is low.

Since the two-component curable coating agent of the present invention can form a coating layer excellent in transparency, hardness, scratch resistance, oil wiping property and tensile elongation, various optical members (touch panel, display, lens, It can be used to form a coating layer for protecting the surface of a substrate that requires visibility such as glass.

Claims

100 parts by weight of an acrylic polymer having a photopolymerizable group and a hydroxyl group in the side chain and having a hydroxyl value of 30 to 350 mgKOH / g and a weight average molecular weight of 5000 to 200000, 0.3 to 35 parts by weight of a silane coupling agent, A main agent comprising 0.3 to 35 parts by weight of a polyether polyol, 3 to 70 parts by weight of a polylactone polyol, and 6 to 500 parts by weight of a photopolymerizable polyfunctional compound having two or more photopolymerizable groups in one molecule; And a two-component curable coating agent comprising 3 to 100 parts by weight of a curing agent containing polyisocyanate.
The main ingredients are 100 parts by weight of an acrylic polymer having a photopolymerizable group and a hydroxyl group in the side chain, a hydroxyl value of 30 to 350 mgKOH / g, and a weight average molecular weight of 5,000 to 200,000, and a silane coupling agent of 0.3 to 35. Parts by weight, 0.3 to 35 parts by weight of a polyether polyol, 3 to 70 parts by weight of a polylactone polyol, and 6 to 500 parts by weight of a photopolymerizable polyfunctional compound having two or more photopolymerizable groups in one molecule. The two-component curable coating agent according to claim 1, wherein a part of the compound is reacted.
The two-component curable coating agent according to claim 1 or 2, wherein the curing agent contains a polyisocyanate derivative.