KR20110025894A - Photocuring-type hydrophilic coating agent, hydrophilic film and hydrophilic coated material - Google Patents

Abstract

(A) 3-40 mass% of acrylic resin, (B) 0.1-5 mass% of polyoxyethylene-polyoxypropylene block copolymer, and (C) 55-photopolymerizable polyfunctional compound which has two or more photopolymerizable groups in 1 molecule. As a photocurable hydrophilic coating agent having fingerprint wipeability containing the resin component containing 95 mass%, acrylic resin (A) is 40-95 mass% of radically polymerizable monomers which have a hydrophilic group, and (meth) acrylic-acid alkylester monomer 5 It has a copolymer of -60 mass% as a main chain.

Description

Photocurable hydrophilic coatings, hydrophilic coatings and hydrophilic coatings {PHOTOCURING-TYPE HYDROPHILIC COATING AGENT, HYDROPHILIC FILM AND HYDROPHILIC COATED MATERIAL}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photocurable hydrophilic coating agent for making it easy to wipe off contaminants such as fingerprints attached to the surface of articles such as touch panels, displays, lenses, and window materials, and hydrophilic coatings and hydrophilic coatings obtained by using the hydrophilic coating agent. .

In recent years, as an input device to an information terminal, a touch panel for inputting information by touching a surface panel of an image display device of an electronic device with a finger or the like has been widely used. When the surface of the touch panel is touched with a finger, fingerprint contamination is likely to adhere. Such fingerprint contamination lowers the visibility of the screen.

As a method for solving such a problem, a method is known in which fingerprint contamination or the like is difficult to adhere to the surface of the touch panel by applying a fluorine-based compound or silicone oil having excellent water repellency and oil repellency to the surface of the touch panel. However, when dirt adhered, it was difficult to fully retain visibility even after wiping off with cloth or the like.

As a technique of suppressing the occurrence of such wiping marks, Patent Document 1 discloses applying a hard coat film containing 100 parts by weight of ionizing radiation curable resin and 0.1 to 10 parts by weight of a nonionic surfactant to the surface of the touch panel. have.

Further, Patent Document 2 discloses a polyether skeleton-containing urethane resin obtained by addition reaction of a polyisocyanate, a polyether polyol containing an alkylene oxide having 3 or more carbon atoms, and a hydroxyl group and a photopolymerizable group-containing monomer as a coating agent applied to the surface of the touch panel, An anti-fingerprint photocurable composition comprising a photopolymerizable polyfunctional compound and a photopolymerization initiator is disclosed.

(Prior art document)

Patent Document 1: Japanese Patent Application Laid-Open No. 2004-114355

Patent Document 2: Japanese Patent Application Laid-Open No. 2008-255301

In the touch panel obtained by applying the hard coat film described in Patent Literature 1, the surface hydrophilicity is deficient, and thus, when the fingerprint contamination is wiped off with water, water penetrates the interface between the fingerprint contamination and the touch panel to make the sebum sufficiently float and wipe off. It was difficult.

In addition, in the touch panel in which the coat layer is formed on the surface using the anti-fingerprint photocurable composition described in Patent Document 2, since the coat layer does not contain a hydroxyl group, hydrophilicity is deficient, water penetrates into the interface between fingerprint contamination and the touch panel. It was difficult to wipe off sebum enough.

The main object of the present invention is to provide a photocurable hydrophilic coating agent capable of imparting high fingerprint wiping property to a substrate surface by coating a substrate surface of various articles such as a touch panel, and a hydrophilic coating obtained by using the hydrophilic coating agent. To provide.

The photocurable hydrophilic coating agent of this invention has 2 or more photopolymerizable groups in 3-40 mass% of (A) acrylic resins, 0.1-5 mass% of (B) polyoxyethylene-polyoxypropylene block copolymers, and (C) 1 molecule. It contains the resin component containing 55-95 mass% of photopolymerizable polyfunctional compounds which have a. The said acrylic resin (A) has a copolymer obtained by copolymerizing 40-95 mass% of radically polymerizable monomers which have a hydrophilic group, and 5-60 mass% of (meth) acrylic-acid alkylester monomers as a principal chain. When such a photocurable hydrophilic coating agent is applied to the substrate surface of various articles to form a coating film, it is possible to impart high fingerprint wiping property and high surface hardness to the surface.

It is preferable that the hydroxyl value of the said acrylic resin (A) is 1-100 mgKOH / g. Moreover, the said acrylic resin (A) is 5-30 mass% of radically polymerizable monomers which have a hydroxyl group, 20-90 mass% of radically polymerizable monomers having a hydrophilic group other than a hydroxyl group, and 5-60 mass% of (meth) acrylic-acid alkylester monomers. It is preferable that it is the (meth) acryloyl group containing acrylic polyol (A1) obtained by adding an isocyanate group containing (meth) acrylate to the copolymer obtained by copolymerizing.

In the case of using such a photocurable hydrophilic coating agent, the (meth) acryloyl group of (A1) in the (meth) acryloyl group-containing acrylic resin becomes a crosslinking point, and thus forms a crosslink with the photopolymerizable polyfunctional compound (C). A higher hardness film is obtained.

It is preferable that the said acrylic resin (A) is the range of the weight average molecular weights 5000-30000.

The photocurable hydrophilic coating agent of the present invention further contains a photopolymerizable monofunctional compound having one photopolymerizable group at a ratio of 50% by mass or less in the resin component, while adjusting the viscosity of the photocurable hydrophilic coating agent and the solid content concentration. It is preferable from the point which can improve drying property by raising the.

It is preferable that the said hydrophilic group is a hydroxyl group, an amide group, a polyalkylene glycol group, or an amino group.

In particular, among the radically polymerizable monomers having the hydrophilic group, the radically polymerizable monomer having a hydrophilic group other than the hydroxyl group is preferably dimethylacrylamide in terms of obtaining a higher hardness.

The hydrophilic coating of the present invention is obtained by photocuring the photocurable hydrophilic coating agent.

In addition, the hydrophilic coating material of this invention is obtained by apply | coating the said photocurable hydrophilic coating agent to the surface of a base material, and then photocuring.

Such hydrophilic coatings and hydrophilic coatings have high fingerprint wipes and high surface hardness.

(Effects of the Invention)

According to the present invention, it is possible to form a hydrophilic coating having high fingerprint wiping property and high surface hardness on the article surface.

The photocurable hydrophilic coating agent of the present invention comprises an acrylic resin (A), a polyoxyethylene-polyoxypropylene block copolymer (B), and a photopolymerizable polyfunctional compound (C) having two or more photopolymerizable groups in one molecule. It contains a resin component.

<Acrylic resin (A)>

The acrylic resin (A) in this invention has a copolymer obtained by copolymerizing 40-95 mass% of radically polymerizable monomers which have a hydrophilic group, and 5-60 mass% of (meth) acrylic-acid alkyl monomers as a principal chain.

The radically polymerizable monomer having a hydrophilic group imparts hydrophilicity to the acrylic resin. As a radically polymerizable monomer which has such a hydrophilic group, it is a monomer which has a radically polymerizable unsaturated bond, and has hydrophilic groups, such as a hydroxyl group, an amide group, a polyalkylene glycol group, an amino group, and each monomer may be used independently, or a hydrophilic group You may use 2 or more types of monomers different from each other.

Specifically, the radically polymerizable monomer which has a hydrophilic group can use the radically polymerizable monomer which has a hydroxyl group, or the radically polymerizable monomer which has hydrophilic groups other than a hydroxyl group independently. Moreover, you may use combining the radically polymerizable monomer which has a hydroxyl group, and the radically polymerizable monomer which has hydrophilic groups other than a hydroxyl group.

It is preferable that the radically polymerizable monomer which has hydrophilic groups other than a hydroxyl group is dimethyl acrylamide.

As a radically polymerizable monomer which has a hydroxyl group as a hydrophilic group, (meth), such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, etc. ) Acrylic acid hydroxyalkyl ester etc. are mentioned. These may be used independently or may be used in combination of 2 or more type. In these, 2-hydroxyethyl (meth) acrylate is used preferably from a reactive viewpoint.

As a radically polymerizable monomer which has an amide group as a hydrophilic group, it is (meth) acrylamide, dimethyl (meth) acrylamide, diethyl (meth) acrylamide, isopropyl (meth) acrylamide, dimethylaminopropyl acrylamide, di Acetone acrylamide, N-methylol acrylamide, etc. are mentioned, Especially, it is preferable to use dimethyl acrylamide.

Examples of the radical polymerizable monomer having a polyalkylene glycol group as the hydrophilic group include methoxy polyethylene glycol 400 methacrylate, methoxy polyethylene glycol 1000 methacrylate, and the like.

As a radically polymerizable monomer which has an amino group as a hydrophilic group, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, diethylaminopropyl (meth) acrylate, etc. are mentioned, for example.

On the other hand, as (meth) acrylic-acid alkylmonomer, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, and benzyl, for example. (Meth) acrylate, dicyclopentadienyl (meth) acrylate, etc. are mentioned. These may be used independently or may be used in combination of 2 or more type. In these, methyl (meth) acrylate is used preferably from the point which is excellent in hardness.

The content rate with respect to the monomer total amount of the radically polymerizable monomer which has a hydrophilic group is 40-95 mass%, Preferably it is 50-90 mass%, More preferably, it is 60-90 mass%. When the content rate of the radically polymerizable monomer which has a hydrophilic group is less than 40 mass%, the hydrophilicity of the film obtained will become inadequate, and when it exceeds 95 mass%, coating film physical properties, such as water resistance of the film obtained, will fall.

Moreover, the content rate with respect to the monomer total amount of an alkyl (meth) acrylic-acid monomer is 5-60 mass%, Preferably it is 10-50 mass%. When the content ratio of the alkyl (meth) acrylate monomer is less than 5% by mass, the lipophilic properties of the obtained film are insufficient, and when it exceeds 60% by mass, the hydrophilicity of the coating is insufficient.

As a method of copolymerizing 40-95 mass% of radically polymerizable monomers which have a hydrophilic group, and 5-60 mass% of alkyl (meth) acrylic-acid monomers, solution polymerization, suspension polymerization, emulsion polymerization, etc. are mentioned, for example. In these, it is preferable to use the solution polymerization which melt | dissolves a monomer liquid mixture in a solvent and superposes | polymerizes in presence of a polymerization initiator as needed.

Examples of the solvent in the solution polymerization include ketone organic solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, ester organic solvents such as methyl acetate, ethyl acetate and butyl acetate, dimethylformamide and dimethyl sulfoxide. , Polar solvents such as N-methyl-2-pyrrolidone, alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, and isopropyl alcohol, aromatic hydrocarbons such as toluene, xylene, and Solveso 100 (manufactured by ExxonMobil Chemical Company) Aliphatic hydrocarbon-based / alicyclic hydrocarbon-based organic solvents such as n-hexane, cyclohexane, methylcyclohexane, `` roth '' (manufactured by Shell Chemicals), and `` Mineral Spirit EC '' (manufactured by Shell Chemicals), methylcello Cellosolve organic solvents such as solve, ethyl vertical solver, butyl cellosolve, ether organic solvents such as tetrahydrofuran and dioxane, carbitols such as n-butylcarbitol and iso-amylcarbitol The organic solvent etc. are mentioned. You may use these individually or in combination of 2 or more types.

As the polymerization initiator, for example, organic peroxides such as benzoyl peroxide, lauroyl peroxide, caproyl peroxide, t-hexyl peroxy neodecanate, t-butyl peroxy pivalate, and 2,2-azo Bis-iso-butyronitrile, 2,2-azobis-2,4-dimethylvaleronitrile, 2,2-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobis-2- Azo compounds, such as methyl butyronitrile ("ABN-E" by the Japan Hydrazine CO., Ltd.), are mentioned. You may use a polymerization initiator individually or in combination of 2 or more types. As content rate of a polymerization initiator, it is preferable that it is 0.01-8 mass parts, and also 0.5-6 mass parts with respect to 100 mass parts of monomer mixture liquids.

As an acrylic resin (A), the (meth) acryloyl group containing acrylic polyol (A1) which introduce | transduced the (meth) acryloyl group with a hydrophilic group can be used. This acryl polyol (A1) can also form a crosslinked structure between the photopolymerizable polyfunctional compound (C) which has two or more photopolymerizable groups in 1 molecule mentioned later. In this case, it is preferable at the point which the hardness of a film further improves.

As (meth) acryloyl-group containing acrylic polyol (A1), for example, 5-30 mass% of radically polymerizable monomers which have a hydroxyl group, 20-90 mass% of radically polymerizable monomers which have hydrophilic groups other than a hydroxyl group, and (meth) acrylic acid (Meth) acryloyl group containing acrylic polyol obtained by addition-reacting isocyanate group containing (meth) acrylate with the obtained copolymer using the copolymer obtained by copolymerizing an alkyl monomer 5-60 mass% is mentioned.

The content rate of the radically polymerizable monomer which has a hydroxyl group is 5-30 mass% with respect to the monomer total amount which comprises an acrylic resin (A), Preferably it is 10-20 mass%. When the content ratio of the radically polymerizable monomer having a hydroxyl group is less than 5% by mass, sufficient hydrophilicity tends not to be obtained, and when it exceeds 30% by mass, coating film properties such as water resistance tend to decrease.

Moreover, the content rate of the radically polymerizable monomer which has a hydrophilic group other than a hydroxyl group is 20-90 mass% with respect to the total amount of the monomer which comprises an acrylic resin (A), Preferably it is 40-85 mass%. When the content ratio of the radically polymerizable monomer having a hydrophilic group other than a hydroxyl group is less than 20% by mass, the hydrophilicity after crosslinking tends to be insufficient, and when it exceeds 90% by mass, it is (meth) acryl It is difficult to introduce a diary.

An example of the manufacturing method of a (meth) acryloyl-group containing acrylic polyol (A1) is demonstrated below.

First, as mentioned above, 5-30 mass% of radically polymerizable monomers which have a hydroxyl group, 20-90 mass% of radically polymerizable monomers having a hydrophilic group other than a hydroxyl group, and 5-60 mass% of (meth) acrylic-acid alkyl monomers are copolymerized. Thus, a solution of acrylic polyol is obtained. Next, the solution of the obtained acrylic polyol is thrown into a reaction container, the isocyanate group containing (meth) acrylate and a metal catalyst are further added, and also polymerization inhibitors, such as hydroquinone (HQ), are added as needed, and oxygen Isocyanate group containing (meth) acrylate is added to the hydroxyl group of an acryl polyol by blowing for 6 to 12 hours, controlling temperature at 30-150 degreeC, blowing, for example, (meth) acryloyl-group containing acrylic polyol (A1) is obtained. Lose.

As an isocyanate group containing (meth) acrylate, (meth) acryl, such as 2-acryloyloxyethyl isocyanate (brand name "Carens MOI" by Showa Denko KK), 2-methacryloyloxyethyl isocyanate, for example And (meth) acryloyl isocyanates or derivatives thereof in which a royl group is bonded to an isocyanate group via an alkylene group having 2 to 6 carbon atoms.

As a derivative, the (meth) acrylate etc. which have an isocyanate group which masked the isocyanate group with the blocking agent are mentioned, for example. Specific examples thereof include methacrylic acid 2- (0- [1'-methylpropylideneamino] carboxyamino) ethyl (trade name "Karenz MOI-BM" manufactured by Showa Denko K.K.) and the like. You may use these individually or in combination of 2 or more types.

Examples of the metal catalyst include dibutyltin dilaurate, dioctyl tin laurate, dioctyl tin dilaurate, bismuth-based catalysts, and the like.

The addition ratio of the isocyanate group-containing (meth) acrylate to the acrylic polyol (A1) is the ratio of the number of moles of isocyanate group (NCO) to the number of moles of hydroxyl group (OH) in the radically polymerizable monomer having a hydroxyl group used for copolymerization (NCO / OH) is preferably added at a ratio of 0.005 to 0.5 or 0.01 to 0.5. By mix | blending in such a ratio, especially a hydroxyl group with high hydrophilicity can be left in a (meth) acryloyl group containing acrylic polyol (A1), without spending all the reaction with an isocyanate group containing (meth) acrylate. Thereby, it can provide to the film obtained with higher hydrophilicity.

It is preferable that the weight average molecular weights (Mw) of acrylic resin (A) are 5000-30000, Furthermore, it is 8000-20000. When the said weight average molecular weight is less than 5000, there exists a tendency for coating film physical properties, such as water resistance, to fall. On the other hand, when the said weight average molecular weight exceeds 30000, compatibility with another component (B) and (C) tends to fall.

The hydroxyl value of the acrylic resin (A) is preferably 1 to 100 mgKOH / g, preferably 5 to 90 mgKOH / g.

The hydroxyl value of the (meth) acryloyl group-containing acrylic polyol (A1) is preferably 1 to 90 mg KOH / g, preferably 5 to 80 mgKOH / g.

When the hydroxyl value is too low, the hydrophilicity of the resulting film tends to be insufficient. Moreover, when hydroxyl value is too high, there exists a tendency for coating film physical properties, such as water resistance, to fall. In addition, a hydroxyl value is the value measured by the potentiometric titration method based on JIS-K0070.

<Polyoxyethylene-polyoxypropylene block copolymer (B)>

The polyoxyethylene-polyoxypropylene block copolymer (B) is a component that imparts hydrophilicity and lipophilic property to the formed film.

The polyoxyethylene-polyoxypropylene block copolymer (B) is ``-(CH <sub>2</sub> CH <sub>2</sub> O) <sub>m-</sub> (wherein m is oxy), which is an oxyethylene block (hereinafter may be referred to as ethylene oxide chain). ``-(CH (CH ₃ ) CH ₂ O) _n- (where n represents oxy) '' and oxypropylene block (hereinafter may be referred to as propylene oxide chain). It represents the repeating number of a propylene unit. " In addition, m and n are one or more integers which may be same or different.

Content of ethylene oxide chain in polyoxyethylene-polyoxypropylene block copolymer (B) [(total mass of ethylene oxide chain in copolymer) / (total mass of ethylene oxide chain and propylene oxide chain in copolymer) ) * 100] is 5-99 mass%, Furthermore, it is preferable that it is 10-90 mass%, Especially 10-70 mass%.

The weight average molecular weight (Mw) of the polyoxyethylene-polyoxypropylene block copolymer (B) is 1000 to 100000, preferably 1500 to 60000, more preferably 2000 to 40000. Moreover, it is preferable at the point which improves hydrophilicity to have active hydrogen groups, such as a hydroxyl group, an amino group, and an amide group, at least one terminal of a polyoxyethylene-polyoxypropylene block copolymer (B).

<Photopolymerizable polyfunctional compound (C)>

A photopolymerizable polyfunctional compound (C) acts as a coating film formation component which has high hardness by photopolymerizing.

As a photopolymerizable polyfunctional compound (C) which has two or more photopolymerizable groups in 1 molecule, if it is a monomer or oligomer which has photopolymerizable groups, such as two or more (meth) acryloyl groups and a vinyl group, in a molecule, it will be used without particular limitation.

Specific examples of the monomer of the photopolymerizable polyfunctional compound (C) having two or more photopolymerizable groups in one molecule include the following compounds.

As a photopolymerizable polyfunctional compound which has two photopolymerizable groups in 1 molecule, alkylene, such as ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and neopentyl glycol di (meth) acrylate, for example. Glycol di (meth) acrylates; Polyalkylene glycol di (meth) acryl, such as diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, and tripropylene glycol di (meth) acrylate Rate; 1,4-butanedioldi (meth) acrylate, 1,6-hexanedioldi (meth) acrylate, 1,9-nonanedioldi (meth) acrylate, dicyclopentadienedi (meth) acrylate, neopentyl Glycol adipate di (meth) acrylate, hydroxy pivalic acid neopentyl glycol di (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, dicyclopentanyldi (meth) acrylate; Pentaerythritol di (meth) acrylate, bisphenol AEO addition diacrylate, caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified phosphoric acid di (meth) acrylate, allylated cyclohexyldi (meth) Acrylate, isocyanurate di (meth) acrylate or alkylene oxide modified compounds thereof, divinylbenzene, butanediol-1,4-divinyl ether, cyclohexanedimethanoldivinyl ether, diethylene glycol divinyl ether, Dipropylene glycol divinyl ether dipropylene glycol divinyl ether, hexanediol divinyl ether, triethylene glycol divinyl ether, phenylglycidyl ether acrylate hexamethylene diisocyanate urethane prepolymer (KYOEISHA CHEMICAL CO., LTD. AH-600 ''), phenylglycidyl ether acrylate toluene diisocyanate urethane prepolymer (KYOEISHA CHEMICAL CO., LTD. "AT-600") and the like are listed.

As a photopolymerizable polyfunctional compound which has three photopolymerizable groups in 1 molecule, for example, trimethylol propane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, and tris ( And acryloxyethyl) isocyanurate or their alkylene oxide modified compounds, and tri (meth) acrylates of isocyanurate alkylene oxide modified compounds.

Examples of the photopolymerizable multifunctional compound having four photopolymerizable groups in one molecule include ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, alkylene oxide modified substances thereof, and the like.

As a photopolymerizable polyfunctional compound which has five photopolymerizable groups in 1 molecule, dipentaerythritol penta (meth) acrylate, those alkylene oxide modified bodies, etc. are mentioned, for example.

As a photopolymerizable polyfunctional compound which has six photopolymerizable groups in 1 molecule, the dipentaerythritol hexa (meth) acrylate and the pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer (KYOEISHA CHEMICAL CO., LTD. Make) "UA-306H"), caprolactone modified dipentaerythritol hexa (meth) acrylate, alkylene oxide modified bodies thereof, and the like.

The photopolymerizable polyfunctional compound (C) mentioned above may be used independently, and may be used in combination of 2 or more type. Among these, it is preferable to use a compound having three or more, preferably four or more, more preferably five or more, and particularly preferably six or more photopolymerizable groups in one molecule. In other words, when the number of photopolymerizable groups contained in one molecule increases, crosslinking becomes more dense, whereby higher surface hardness is obtained.

Moreover, you may mix | blend the photocurable monofunctional compound which has one photopolymerizable group in 1 molecule as needed in the photocurable hydrophilic coating agent of this invention in the range which does not impair the objective of this invention. A photopolymerizable monofunctional compound is used in order to adjust the viscosity of a photocurable hydrophilic coating agent, and to improve the dryness of a photocurable hydrophilic coating agent by increasing solid content concentration. As a specific example of a photopolymerizable monofunctional compound, For example, aliphatic (meth) acrylate, alicyclic (meth) acrylate, aromatic (meth) acrylate, ether (meth) acrylate, vinyl monomer, (meth ) Acrylamides and the like.

As a photopolymerizable monofunctional compound, for example, 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, Toxy-diethylene glycol (meth) acrylate, 2-ethylhexyl-carbitol (meth) acrylate, neopentyl glycol benzoate (meth) acrylate, nonyl phenoxy polyethylene glycol (meth) acrylate, ECH modified phenoxy (Meth) acrylate, phenoxyethyl (meth) acrylate, paracumyl phenol ethylene oxide modified (meth) acrylate, vinylpyrrolidone, vinyl caprolactam, acryloyl morpholine, etc. are mentioned.

As a content rate of a photopolymerizable monofunctional compound, it is preferable that it is 50 mass% or less, Furthermore, 30 mass% or less, especially 20 mass% or less in a resin component.

It is preferable that the photocurable hydrophilic coating agent of this invention contains a photoinitiator. By containing a photoinitiator, hardening of a photopolymerizable polyfunctional compound (C) can be promoted.

As a photoinitiator, a benzoin ether type photoinitiator, a benzophenone type photoinitiator, a thioxanthone type photoinitiator, an alkylphenone type photoinitiator, an acylphosphine oxide type photoinitiator, a titanocene type photoinitiator, an oxime ester type photoinitiator, for example Examples thereof include an initiator, a diazophenylamine photopolymerization initiator, a naphthoquinone diazosulfonic acid photopolymerization initiator, and a dimethylaminobenzoic acid photopolymerization initiator.

As a benzoin ether type photoinitiator, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, etc. are mentioned, for example.

Examples of the benzophenone-based photopolymerization initiators include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenylsulfide, 2,4,6-trimethylbenzophenone, and the like. do.

As a thioxanthone type photoinitiator, 2-isopropyl thioxanthone, 2, 4- diethyl thioxanthone, 2, 4- dichloro thioxanthone, 1-chloro-4- propoxy thioxanthone, etc. are mentioned, for example. This is listed.

As an alkylphenone type photoinitiator, 2-hydroxy-2-methyl-1- phenyl- propane- 1-one, 2, 2- dimethoxy- 1, 2- diphenyl ethane- 1-one, 1-, for example 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-propane-1-one, 2-methyl-1- (4-methylthiophenyl)- 2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl ) Methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone and the like.

As an acyl phosphine oxide type photoinitiator, 2,4,6- trimethyl benzoyl- diphenyl- phosphine oxide, bis (2, 4, 6- trimethyl benzoyl)-phenylphosphine oxide, etc. are mentioned, for example.

As a titanocene type photoinitiator, it is bis ((eta5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl), for example. Titanium and the like.

Examples of the oxime ester photopolymerization initiators include 1.2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], ethanone, and 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) ethylester and the like. These photoinitiators may be used independently or may be used in combination of 2 or more type.

As content rate of a photoinitiator, it is preferable to add about 0.5-10 mass% with respect to the total amount of a photopolymerizable polyfunctional compound (C).

<Photocurable hydrophilic coating agent>

The content rate of the acrylic resin (A) in the resin component in the photocurable hydrophilic coating agent of this invention is 3-40 mass% with respect to the gross mass of a resin component, Preferably it is 6-35 mass%, More preferably, it is It is the range of 10-30 mass%. When the content rate of acrylic resin (A) is less than 3 mass% with respect to the gross mass of a resin component, since hydrophilicity and lipophilic sufficient for the obtained hydrophilic film fall, the fingerprint wipe resistance of a hydrophilic film falls. Moreover, when the content rate of an acrylic resin (A) exceeds 40 mass%, surface hardness sufficient for the hydrophilic film obtained will fall.

The content rate of the polyoxyethylene-polyoxypropylene block copolymer (B) in the resin component in the photocurable hydrophilic coating agent of this invention is 0.1-5 mass% with respect to the gross mass of a resin component, Preferably it is 0.5- 3 mass%, More preferably, it is the range of 0.5-2 mass%. When the content ratio of the polyoxyethylene-polyoxypropylene block copolymer (B) is less than 0.1 mass% with respect to the total mass of the resin component, sufficient hydrophilicity and lipophilicity of the resulting hydrophilic film decreases, so that the fingerprint wipeability of the hydrophilic film is reduced. When it falls and exceeds 5 mass%, the surface hardness sufficient for the obtained hydrophilic film falls.

The content rate of the photopolymerizable polyfunctional compound (C) which has two or more photopolymerizable groups in 1 molecule in the resin component in the photocurable hydrophilic coating agent of this invention is 55-95 mass% with respect to the gross mass of a resin component, Preferably it is 60-90 mass%, More preferably, it is the range of 65-85 mass%. When the content ratio of the photopolymerizable polyfunctional compound (C) is less than 55% by mass relative to the total mass of the resin component, sufficient surface hardness of the obtained hydrophilic film is lowered, and when the content of the hydrophilic film is greater than 95% by mass, sufficient hydrophilicity is obtained. And lipophilic properties are lowered.

In the photocurable hydrophilic coating agent of the present invention, various additives such as an ultraviolet absorber, an antioxidant, an optical stabilizer, a heat stabilizer, an antistatic agent, an antifoaming agent, and the like may be further blended as necessary without departing from the effect of the present invention.

The photocurable hydrophilic coating agent of the present invention is a photopolymerizable having a resin solution of an acrylic resin (A) prepared as described above, a polyoxyethylene-polyoxypropylene block copolymer (B), and two or more photopolymerizable groups in one molecule. A polyfunctional compound (C), a photoinitiator, and various additives added as needed, the solvent used for viscosity adjustment, or a reactive diluent are added so that it may become the above-mentioned content ratio, and it is prepared by stirring and mixing.

Although content (non-volatile content, ie, ratio of solid content) of the component except the solvent in the photocurable hydrophilic coating agent of this invention is not specifically limited, It is 10-80 mass%, Preferably it is 20-60 mass%. When the ratio of nonvolatile matter is in the said range, it is excellent in coatability and the stability of a photocurable hydrophilic coating agent is excellent.

It is apply | coated to the surface of substrates, such as a surface panel, such as a touch panel and a display, and a sheet | seat and a film for protecting the said surface. Then, the hydrophilic coating is obtained by applying the photocurable hydrophilic coating agent on the surface of the substrate and photocuring the same.

Although it does not specifically limit as a material of a base material, For example, various resin base materials, such as polycarbonate resin, polyacrylic resin, and styrene resin, inorganic base materials, such as glass, etc. are mentioned, A metal base material may be sufficient.

The coating method is not particularly limited, and examples thereof include dipping, roll coating, spin coating, bar coating, and the like.

The applied photocurable hydrophilic coating agent is photocured by irradiating light such as ultraviolet rays to form a hydrophilic coating. Since the photocurable hydrophilic coating agent of this invention uses photocuring for film formation, it can form a film with high productivity compared with a thermosetting hydrophilic coating agent, and there is no possibility that a base material may deteriorate by heat.

By using (meth) acryloyl-group containing acrylic polyol (A1) as an acrylic resin (A), a crosslinked structure is formed between the photopolymerizable polyfunctional compound (C) which has two or more photopolymerizable groups in 1 molecule. By the formation of this crosslinked structure, the hardness of the hydrophilic coating is further improved.

Although the film thickness of the hydrophilic film formed on the base material is not specifically limited, It is good that it is 2-90 micrometers, Preferably it is about 5-50 micrometers.

Such a hydrophilic coating is bonded to a surface of an image display panel to be installed on the outermost layer of an image display device such as a touch panel or a display that is easily attached with fingerprints by contact with a person, and the surface protection bonded to the surface of the image display panel in order to protect the image display panel. It is formed in order to improve fingerprint wiping property on the surface of a film, lens surfaces such as glasses and goggles, and the surface of window materials for construction, vehicles, and instruments.

(Example)

Hereinafter, an Example demonstrates this invention further in detail. In addition, this invention is not limited to an Example at all, The arbitrary deformation | transformation is possible within the range of the technical idea of this invention. In addition, in a following example and a comparative example, "part" means a "mass part."

<< synthesis example of acrylic resin (A) >>

Synthesis Example 1

233 parts of methyl ethyl ketone (MEK) were thrown into the reaction container as a solvent, and it heated up to 70 degreeC.

On the other hand, in the monomer component which consists of 40 parts of methyl methacrylate (MMA), 50 parts of dimethyl acrylamide (DMAA), and 10 parts of 2-hydroxyethyl acrylate (2-HEA), it is azobis-2-methylbuty as a polymerization catalyst. The monomer liquid mixture was prepared by stirring and mixing 4 parts of ronitrile ("ABN-E" by Japan Hydrazine CO., Ltd.).

The monomer liquid mixture was dripped at the solvent over 2 hours at 70 degreeC, and it aged for 4 hours after completion | finish of dripping, and obtained the resin solution of about 30% of non volatile matter containing an acrylic polyol. The hydroxyl value of the obtained acrylic polyol was 16 mgKOH / g, and the weight average molecular weight (Mw) was 12000. In addition, the viscosity (Gardner / 25 degreeC) of the obtained resin solution was A4.

Synthesis Example 2

A resin solution containing an acrylic polyol was obtained in the same manner as in Synthesis Example 1 except that the monomer component consisting of 30 parts of MMA, 50 parts of DMAA, and 20 parts of 2-HEA was used as the monomer component. The hydroxyl value of the obtained acrylic polyol was 31 mgKOH / g, and the weight average molecular weight (Mw) was 10000. In addition, the viscosity (Gardner / 25 degreeC) of the obtained resin solution was A4.

Synthesis Example 3

A resin solution containing an acrylic polyol was obtained in the same manner as in Synthesis Example 1 except that the monomer component consisting of 10 parts of MMA, 80 parts of DMAA, and 10 parts of 2-HEA was used as the monomer component. The hydroxyl value of the obtained acrylic polyol was 16 mgKOH / g, and the weight average molecular weight (Mw) was 13000. In addition, the viscosity (Gardner / 25 degreeC) of the obtained resin solution was A4.

Synthesis Example 4

A resin solution containing an acrylic polyol was obtained in the same manner as in Synthesis Example 1 except that the monomer component consisting of 10 parts of MMA, 70 parts of DMAA, and 20 parts of 2-HEA was used as the monomer component. The hydroxyl value of the obtained acrylic polyol was 31 mgKOH / g, and the weight average molecular weight (Mw) was 11000. In addition, the viscosity (Gardner / 25 degreeC) of the obtained resin solution was A4.

Synthesis Example 5

Except having used the monomer component which consists of 40 parts of MMA, 50 parts of methoxy polyethylene glycol 400 methacrylate ("NK ester M-90G" by Shin-Nakamura Chemical CO., Ltd.), and 10 parts of 2-HEA In the same manner as in Synthesis example 1, a resin solution containing an acrylic polyol was obtained. The hydroxyl value of the obtained acrylic polyol was 20 mgKOH / g, and the weight average molecular weight (Mw) was 11000. In addition, the viscosity (Gardner / 25 degreeC) of the obtained resin solution was A4.

Synthesis Example 6

Except having used the monomer component which consists of 90 parts of MMA and 10 parts of 2-HEA as a monomer component, it carried out similarly to the synthesis example 1, and obtained the resin solution containing an acrylic polyol. The hydroxyl value of the obtained acrylic polyol was 16 mgKOH / g, and the weight average molecular weight (Mw) was 10000. In addition, the viscosity (Gardner / 25 degreeC) of the obtained resin solution was A4.

Synthesis Example 7

Except having used the monomer component which consists of 100 parts of MMA as a monomer component, it carried out similarly to the synthesis example 1, and obtained the resin solution containing an acrylic resin. The hydroxyl value of the obtained acrylic resin was 0, and the weight average molecular weight (Mw) was 12000. In addition, the viscosity (Gardner / 25 degreeC) of the obtained resin solution was A4.

Synthesis Example 8

A resin solution containing an acrylic polyol was obtained in the same manner as in Synthesis Example 1 except that the monomer component consisting of 80 parts of MMA, 10 parts of DMAA and 10 parts of 2-HEA was used as the monomer component. The hydroxyl value of the obtained acrylic polyol was 16 mgKOH / g, and the weight average molecular weight (Mw) was 10000. In addition, the viscosity (Gardner / 25 degreeC) of the obtained resin solution was A4.

The above result is put together in Table 1 and shown.

<< synthesis of reactant (A1) of acryl polyol and isocyanate group containing methacrylate >>

(Synthesis Examples 9-16)

According to the composition of Table 2, the resin solution (30% of non volatile matter) and 2-methacryloyloxyethyl isocyanate (MOI) of the acrylic polyol obtained by the synthesis examples 1-6 and the synthesis example 8 in reaction container of the product made by Showa Denko KK `` Karenz MOI ''), hydroquinone (HQ), dibutyltin dilaurate and MEK were added, and each acrylic polyol and isocyanate group-containing methacrylate were reacted by controlling the temperature to 60 ° C for 6 hours while blowing oxygen. Reaction was obtained. In addition, the composition in Table 2 is shown by resin powder. In the synthesis examples 9-15, the ratio (NCO / OH) of the number-of-moles of an isocyanate group (NCO) with respect to the number-of-moles of hydroxyl group (OH) was 0.5, and it was 1 about the synthesis example 16. In Synthesis Example 16, gelation occurred in the middle of the reaction to terminate the reaction.

In Table 2, the composition of the reaction component in Synthesis Examples 9-16 and the hydroxyl value (mgKOH / g), the weight average molecular weight (Mw), the viscosity (Gardner / 25 degreeC), and the non volatile matter concentration of the obtained reaction product are shown collectively.

Other raw materials used in the present embodiment will be collectively described below.

<Polyether polyol (B)>

Polyethylene oxide-polypropylene oxide glycol ether: U105 ("Evan U105" produced by DAI-ICHI KOGYO SEIYAKU CO., LTD., Weight average molecular weight 6400, ethylene oxide content 50 mass%)

<Photopolymerizable polyfunctional compound (C) having two or more photopolymerizable groups in one molecule>

Pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer: UA-306H (“UA-306H” manufactured by KYOEISHA CHEMICAL CO., LTD .; has six photopolymerizable groups in one molecule.)

Phenylglycidyl ether acrylate hexamethylene diisocyanate urethane prepolymer: AH-600 ("AH-600" by KYOEISHA CHEMICAL CO., LTD .; has two photopolymerizable groups in 1 molecule.)

Dipentaerythritol hexaacrylate: DPE-6A ("Light acrylate DPE-6A manufactured by KYOEISHA CHEMICAL CO., LTD .; has 6 photopolymerizable groups in 1 molecule.)

Pentaerythritol triacrylate: PE-3A ("Light acrylate PE-3A manufactured by KYOEISHA CHEMICAL CO., LTD .; has three photopolymerizable groups in 1 molecule.")

<Photoinitiator>

2-hydroxy-2-methyl-1-phenyl-propan-1-one: DAROCUR 1173 ("DAROCUR 1173" made by Ciba Specialty Chemicals K.K.)

<Photoreactive Diluent>

Acryloyl morpholine: ACMO (`` ACMO '' by Kohjin CO., LTd.)

(Example 1)

10 parts (non-volatile matter) 3 parts of resin solution of 30% of non volatile matter containing the acryl polyol obtained by the synthesis example 1, 0.5 parts of polyethylene oxide polypropylene oxide glycol ether (U105), pentaerythritol triacrylate hexamethylene di The photocurable hydrophilic coating agent was prepared by stirring and mixing 27 parts of isocyanate urethane prepolymers (UA-306H), 0.8 parts of 2-hydroxy-2-methyl-1-phenyl-propane-1-one (DAROCUR 1173) and 63 parts of MEK. .

And the obtained photocurable hydrophilic coating agent was apply | coated on the polyethylene terephthalate (PET) film using bar coater No. 10 so that dry film thickness might be set to about 5 micrometers. And after removing a solvent by heating at 80 degreeC x 2 minutes, the photocurable hydrophilic coating material which hardened the ultraviolet-ray exposure and apply | coated at 400 mJ / cm <^2> using the high pressure mercury lamp (120W / cm) was hardened.

The formed cured film was evaluated in accordance with the following evaluation methods.

<Film appearance>

Based on the test method of 4.4 "Overview of Coating Film" of JIS K 5600-1-1, the presence or absence of transparency and crack was determined by the following reference | standard.

Excellent: Colorless transparent, no cracks.

Poor: cloudy or cracked.

<Pencil hardness>

The pencil hardness test was implemented based on the test method of JISK5600-5-4 "scratch hardness (pencil method)." In the pencil hardness test, the hardness is listed in the order of B, HB, F, and H from low to high. In addition, the larger the number in front of "H", the higher the hardness. The larger the number in front of "B", the lower the hardness.

<Adhesiveness>

An adhesive test was carried out in accordance with the test method of "Cross Cut Method" of JIS K 5600-5-6.

Specifically, 100 crosscuts (cut pieces) were formed so as to cut the coating film applied to the test plate in the vertical and horizontal directions with a cutter knife to reach the substrate. And the adhesive tape ("Nichiban tape No. 1" by NICHIBAN CO., LTD.) Was affixed on the crosscut. And after peeling the adherent cellophane adhesive tape, the number of the crosscuts remaining without peeling was counted.

<Oil wipes>

0.1 g of normal hexadecane was poured to the surface of a test plate. And normal hexadecane adhering to the test plate surface was wiped 10 times by applying a 300g load with the cellulose nonwoven fabric ("Coat M-3 by Asahi Kasei Corporation"). The haze (turbidity) of the test plate surface before and after a test was measured using the haze meter NDH 5000 (made by Nippon Denshoku Industries CO., Ltd.). And the difference (DELTA) E of the haze before and after a test was computed. The smaller the value of ΔE, the better the wiping property of the fingerprint marks resulting from sebum, that is, the better antifouling property.

<Water contact angle>

0.4 μL of water was poured onto the test plate surface, and the contact angle was measured by a contact angle meter (“Drop Master 500” manufactured by Kyowa Interface Science CO., LTD.).

<Oil contact angle>

0.4 microliter of oleic acid was made to flow on the test board surface, and the contact angle was measured with the contact angle meter ("Drop Master 500" by Kyowa Interface Science CO., LTD.).

Table 3 shows the test results.

(Examples 2-20 and Comparative Examples 1-14)

Except having prepared the photocurable hydrophilic coating agent according to the composition of Table 3 and Table 4, it carried out similarly to Example 1, and obtained the photocurable hydrophilic coating agent. The results are shown in Tables 3 and 4.

As for the film obtained by the photocurable hydrophilic coating agent prepared in Examples 1-20, (DELTA) E which shows the haze (turbidity) at the time of wiping off normal hexadecane in oil wiping evaluation was 1.0 or less. Moreover, the water contact angle was 65 degrees or less and the oil contact angle was 25 degrees or less, and it was excellent in hydrophilicity and lipophilic property. Therefore, it is confirmed that the film obtained by the photocurable hydrophilic coating agent prepared in Examples 1 to 20 is excellent in fingerprint wiping property. In addition, all of the external appearance of the film were colorless and transparent, and no crack was generated. In addition, pencil hardness was all H or more, and peeling of a film was not seen also in an adhesive test.

On the other hand, in the film obtained by the comparative examples 1-5, (DELTA) E is 3.2 or more in oil wipe wipeability evaluation, and it is confirmed that fingerprint wipeability is inferior. In addition, the water contact angle and the oil contact angle were high, resulting in a lack of hydrophilicity and lipophilicity. It is considered that this is because the acrylic polyol does not contain a radically polymerizable monomer unit having a hydrophilic group other than a hydroxyl group, or because the hydrophobicity of the film is insufficient because the oil polyol is difficult to transfer to the nonwoven fabric when wiped off.

It is confirmed that the film obtained in Comparative Examples 6 to 9 also has a high ΔE in oil wipe wipeability evaluation and is poor in fingerprint wipe. It is considered that this is because the hydrophilicity and lipophilic property of the film are deficient because it does not contain any of the acrylic polyol and the polyether polyol.

It is confirmed that the film obtained in Comparative Example 10 also has a high ΔE in oil wipe wipeability evaluation and poor fingerprint wipe. It is considered that this is because the hydrophilicity and lipophilic property of the film are deficient because it does not contain an acrylic polyol.

The film obtained in the comparative example 11 is an example which raised the content rate of polyether polyol in order to provide hydrophilicity and lipophilic with respect to the film obtained in the comparative example 10. Although hydrophilicity and lipophilic property improved a little by increasing the content rate of a polyether polyol, hardness fell significantly.

It is confirmed that the film obtained in Comparative Example 12 has a slightly higher ΔE in the oil wipe wipeability evaluation and thus insufficient fingerprint wipe. This is considered to be because the hydrophilicity of the film is deficient because it does not contain a polyether polyol.

Moreover, the film obtained by the comparative example 13 also has a little high ΔE in oil wipe wipeability evaluation, and it is confirmed that fingerprint wipeability is inadequate. This is considered to be because the content ratio of the acryl polyol is too low and the hydrophilicity of the film is deficient.

Moreover, the film obtained by the comparative example 14 had low (DELTA) E in oil wipe wipe evaluation, and was excellent in fingerprint wipeability. However, it is confirmed that the content ratio of the acrylic polyol is too high and the hardness of the film is lowered.

(Industrial availability)

Since the hydrophilic coating agent of the present invention can form a hydrophilic coating or a hydrophilic coating having high fingerprint wipeability and high surface hardness on the surface of an article, the surface of an image display panel provided in the outermost layer of an image display apparatus such as a display, In addition to the surface of the surface protection film to be bonded to the surface in order to protect the image display panel, the surface of the lens such as glasses, goggles, surface of the touch panel, etc. in addition to the window surface for building, vehicle, instrument, etc.

In addition, the hydrophilic coating agent of the present invention is effective not only for wiping fingerprints but also for wiping other oil contamination.

Claims (9)

(A) 3-40 mass% of acrylic resin, (B) 0.1-5 mass% of polyoxyethylene-polyoxypropylene block copolymer, and (C) 55-photopolymerizable polyfunctional compound which has two or more photopolymerizable groups in 1 molecule. As a photocurable hydrophilic coating agent containing the resin component containing 95 mass%:
Said acrylic resin (A) has a copolymer obtained by copolymerizing 40-95 mass% of radically polymerizable monomers which have a hydrophilic group, and 5-60 mass% of (meth) acrylic-acid alkylester monomers as a principal chain, The photocurable hydrophilic body a copy. The method of claim 1,
The acrylic resin (A) has a hydroxyl value in the range of 1 to 100 mgKOH / g, wherein the photocurable hydrophilic coating agent. The method of claim 1,
The said acrylic resin (A) copolymerizes 5-30 mass% of radically polymerizable monomers which have a hydroxyl group, 20-90 mass% of radically polymerizable monomers which have a hydrophilic group other than a hydroxyl group, and 5-60 mass% of (meth) acrylic-acid alkylester monomers. It is a (meth) acryloyl group containing acrylic polyol (A1) obtained by adding an isocyanate group containing (meth) acrylate to the copolymer obtained by making it photo-curable hydrophilic coating agent. The method of claim 1,
The weight average molecular weight of the said acrylic resin (A) is the range of 5000-30000, The photocurable hydrophilic coating agent characterized by the above-mentioned. The method of claim 1,
The photocurable monofunctional compound which has one photopolymerizable group is further contained in the ratio of 50 mass% or less in a resin component, The photocurable hydrophilic coating agent characterized by the above-mentioned. The method of claim 1,
Said hydrophilic group is a hydroxyl group, an amide group, a polyalkylene glycol group, or an amino group, The photocurable hydrophilic coating agent characterized by the above-mentioned. The method of claim 1,
The radically polymerizable monomer which has a hydrophilic group other than a hydroxyl group among the radically polymerizable monomers which have a hydrophilic group is dimethyl acrylamide, The photocurable hydrophilic coating agent characterized by the above-mentioned.  It is obtained by photocuring the photocurable hydrophilic coating agent of Claim 1, The hydrophilic film characterized by the above-mentioned. It is obtained by apply | coating the photocurable hydrophilic coating agent of Claim 1 to the surface of a base material, and photocuring, The hydrophilic coating object characterized by the above-mentioned.