JPH0827291A - Production of antifogging coated article - Google Patents

Abstract

PURPOSE:To obtain a coated article provided with both an excellent atifogging property and an excellent hot water-resistant property by coating a specific primer composition on a plastic substrate, thermally curing the coated primer, and subsequently irradiating active rays on the cured coating film in a state in which the cured coating film is brought into contact with a specific photocurable composition. CONSTITUTION:This method for producing an antifogging coated article comprises coating a composition comprising (A) a silane coupling agent of the formula (R<1>-R<3> are each a halogen, lower alkyl, lower alkoxy, etc., but at least one of R<1>-R<3> is the group excluding lower alkyl; X is a lower alkyl having a vinyl or (meth)acryloyl group at the end) or its hydrolystate, (B) a hydrophobic multifunctional (meth)acrylate having plural (meth)acryloyl groups, and (C) a photopolymerization initiator as a primer coating layer on a plastic substrate or an isarganic substrate, thermally curing the formed primer coating layer, and subsequently irradiating active rays on the cured coating film in a state brought into contact with a composition comprising (D) a (meth)acryloyl group-containing hydrophilic monomer and the component D to photochemically cure the composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing an antifogging coated article.

[0002]

2. Description of the Related Art Conventionally, plastics and inorganic glasses used as transparent materials have a drawback that when the surface temperature becomes lower than the dew point, the surface becomes cloudy and the transparency is impaired. Until now, various proposals have been made as methods for preventing fogging. For example, (1) a method of forming a water-absorbing film by copolymerizing a hydrophilic acrylate monomer having an alcoholic hydroxyl group with a specific polyfunctional monomer or by crosslinking a water-soluble polymer such as polyvinyl alcohol is known. There is. Further, a method is known in which (2) a surfactant is kneaded into the resin of the molded product, or (3) a composition containing the surfactant is applied to the surface of the base material.

However, according to the method (1), since the water absorption of the film is controlled by the degree of cross-linking, it is difficult to satisfy both the expression of antifogging property and the imparting of water resistance by the water absorption of the film. It was Further, the methods (2) and (3) also have a problem that the antifogging property is significantly reduced when the surfactant flows out by water.

As a method for solving these problems, for example, in Japanese Patent Publication No. Sho 61-40695, after a hydrophobic monomer mixture having two or more unsaturated groups is prepolymerized and gelled, A method in which a hydrophilic monomer having a hydrophilic group such as a carboxyl group, a sulfonic acid group, a sulfuric acid group, a phosphoric acid group, an amino group, and a hydroxyl group and a polymerizable unsaturated group is brought into contact with the surface and copolymerized on the surface is It is disclosed. However, this method has a problem that it is difficult to control the degree of prepolymerization.

Further, in Japanese Patent Laid-Open No. 56-63845, an inorganic base material or an organic base material whose surface is coated with an inorganic material is provided with a first functional group that reacts with the inorganic material and a second functional group that reacts with the organic material. And a product having a hydrophilic layer provided on the surface by reacting the second functional group with a hydrophilic monomer, an oligomer, or a mixture thereof after treating with a coupling agent having A manufacturing method thereof is disclosed.

Further, Japanese Patent Laid-Open No. 4-225301 discloses a method in which a silane coupling agent is bonded to a base material containing silicon oxide on the surface, and then a reactive surfactant is bonded to the silane coupling agent. Is disclosed.

However, in these methods, it is necessary that at least the surface of the substrate has an inorganic substance or silicon oxide, and since the layer of the coupling agent is extremely thin, it is involved in the reaction with the hydrophilic monomer and the like. There is a problem that there are very few active points.

Further, in JP-A-56-43367, a mixture of a vinyl group-containing silane coupling agent and a bifunctional or higher functional vinyl group-containing cross-linking agent is applied to a transparent substrate, and the vinyl group is polymerized. A method is disclosed in which, after curing, a silanol group is generated by hydrolysis in the presence of an acid catalyst to form an antifogging film. However, this method has a problem that the antifogging property is deteriorated when the silanol group is further dehydrated and condensed.

[0009]

DISCLOSURE OF THE INVENTION The present invention solves the above problems and an object thereof is to provide a method for producing an antifogging coated article having both excellent antifogging property and warm water resistance. Especially.

[0010]

The method for producing an antifogging coated article according to the present invention comprises applying the composition (A) as a subbing layer on a plastic substrate or an inorganic substrate, followed by heat curing. And a second step of irradiating with actinic rays in a state where the composition (B) is brought into contact with the obtained cured coating to perform photo-curing.

The composition (A) comprises a silane coupling agent or its hydrolyzate (a), a hydrophobic polyfunctional (meth) acrylate compound (b) and a photopolymerization initiator (c).

Examples of the base material include plastic plate-shaped molded products such as acrylic resin and polycarbonate, and inorganic glass plates. These substrates may be subjected to pretreatment, if necessary, for the purpose of further improving the adhesiveness. Examples of the pretreatment include corona discharge treatment, glow discharge treatment, treatment with ionizing actinic rays such as ultraviolet rays, electron beams, and radiation; surface roughening treatment; chemical treatment; primer treatment.

The silane coupling agent (a) is represented by the following general formula (1).

[0014]

Embedded image

In the general formula (1), R¹~ R³Is it
Each independently, a halogen atom, a lower alkyl group, a lower alkyl group.
Rucoxy group or lower acetoxy group, R¹, R²Over
And R ³At least one of halogen atom and lower alcohol
Represents an oxy group or a lower acetoxy group, and X is vinyl at the terminal
Group or lower alkyl having (meth) acryloyl group
Represents a group.

Examples of the silane coupling agent (a) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltriacetoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, vinyldimethoxysilane,
γ-methacryloxypropyltrimethoxysilane, γ-
Methacryloxypropyltriethoxysilane, γ-methacryloxyethyltrimethoxysilane, γ-methacryloxyethyltrimethoxysilane, γ-methacryloxyethyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxy Examples thereof include silane, γ-acryloxyethyltrimethoxysilane, and γ-acryloxyethyltriethoxysilane. These may be used alone or in combination of two or more.

The silane coupling agent (a) is optionally hydrolyzed in advance to give a halogen atom in the molecule,
Part or all of the lower alkoxy group or lower acetoxy group may be substituted with a hydroxyl group, and the hydroxyl groups may be condensed with each other. Examples of the hydrolysis method include a method in which the silane coupling agent (a) is diluted with water alone or a mixed solvent of water and an alcohol, and an acid or an alkali catalyst is added to the mixture to react.

The above-mentioned hydrophobic polyfunctional (meth) acrylate compound (b) contains at least two (meth) acryloyl groups in one molecule and is substantially insoluble in water (meth). Acrylate compounds are preferable, for example, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, caprolactone-modified dipentaerythritol hexaacrylate, trimethylolpropane tri (meth) acrylate. Acrylate, EO
(Ethylene oxide) modified trimethylolpropane triacrylate, PO (polyethylene oxide) modified trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, bisphenol A
Di (meth) acrylate, EO-modified bisphenol A di (meth) acrylate, dimethylol tricyclodecane diacrylate, neopentyl glycol di (meth) acrylate, tris (acryloxyethyl) isocyanurate, tris (methacryloxyethyl) isocyanurate In addition, bifunctional or higher functional urethane acrylates, polyester acrylates and the like can be mentioned.

In the composition (A), the hydrophobic polyfunctional (meth) acrylate compound (b) does not participate in the cross-linking in the first step, and when the amount is large, the cured film is easily attacked in the second step. When the amount of the (meth) acrylate compound (b) decreases, the amount of the hydrophilic monomer to be copolymerized on the surface decreases. Therefore, the amount of the (meth) acrylate compound (b) used is 100 parts by weight of the silane coupling agent (a). 10 to 300 parts by weight is preferable.

The photopolymerization initiator (c) may be any one as long as it has a property of polymerizing the hydrophobic polyfunctional (meth) acrylate compound (b) with active rays such as ultraviolet rays and visible rays. Such photopolymerization initiators are described in detail in "Ultraviolet Curing System" (Kiyomi Kato, General Technology Center, Inc.).

As the photopolymerization initiator (c) which is activated by ultraviolet rays, for example, sodium methyldithiocarbamate sulfide, tetramethylthiuram monosulfide,
Sulfides such as diphenyl monosulfide, dibenzothiazoyl monosulfide and disulfide; thioxanthone derivatives such as thioxanthone, ethylthioxanthone, 2-chlorothioxanthone, diethylthioxanthone, diisopropylthioxanthone; diazo such as hydrazone, azoisobutyronitrile and benzenediazonium Compounds: benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzophenone, dimethylaminobenzophenone, Michler's ketone, benzylanthraquinone, t-butylanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-aminoanthraquinone, 2 -Chloroanthraquinone, benzyl dimethyl ketal, methyl Aromatic carbonyl compounds such as phenylglyoxylate; 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2 -Propyl) ketone, 2,2-diethoxyacetophenone, acetophenone derivatives such as 2,2-dimethoxyacetophenone; 4
-Methyl dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, butyl 4-dimethylaminobenzoate,
Dialkylaminobenzoic acid esters such as isopropyl 4-diethylaminobenzoate; peroxides such as benzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide, cumene hydroperoxide; 9-phenylacridine, 9-p. Acridine derivatives such as -methoxyphenylacridine, 9-acetylaminoacridine and benzacridine; 9,10-dimethylbenzphenazine, 9-methylbenzphenazine,
Phenazine derivatives such as 10-methoxybenzphenazine; quinoxaline derivatives such as 4,4 ', 4 "-trimethoxy-2,3-diphenylquinoxaline; 2,4,5
-Triphenylimidazoyl dimer; halogenated ketones; acylated phosphorus compounds such as acylphosphine oxide and acylphosphonate.

Examples of the photopolymerization initiator (c) which is activated by visible light include 2-nitrofluorene, 2,
4,6-tris (trichloromethyl) -1,3,5-triazine, 3,3′-carbonylbiscoumarin, thiomichler ketone and the like can be mentioned. The photopolymerization initiator (c)
Is selected in consideration of stability depending on the temperature conditions and the like at the time of heat curing in the first step.

When the amount of the photopolymerization initiator (c) used in the composition (A) increases, problems such as yellowing of the cured coating or brittleness of the cured coating occur. Insufficient hydrophobic polyfunctional (meta)
0.1 to 100 parts by weight of the acrylate compound (b)
It is preferably 10 parts by weight.

Further, the composition (A) contains, if necessary,
A silane coupling agent having a functional group other than a vinyl group and a (meth) acryloyl group, for example, an epoxy group, an amino group, a mercapto group, a chloro group, an ultraviolet absorber, an antioxidant, a leveling agent, a surfactant, etc. May be added.

The composition (A) may be diluted with a solvent if necessary. Examples of the solvent used include alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, and benzyl alcohol; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve. Other
Examples thereof include ethyl acetate, tetrahydrofuran, toluene and the like, and these may be used alone or in combination of two or more kinds.

In the first step of the production method of the present invention, the reactive silyl group is crosslinked by applying the composition (A) as an undercoat layer on one or both sides of the substrate, and then heating to coat the substrate. A cured coating of the undercoat layer is formed.

As a method for providing the undercoat layer on the above-mentioned substrate, a conventionally known method can be applied, and examples thereof include coating by spray coating, bar coating, dipping, roll coating, spin coating and the like.

The composition (B) comprises the hydrophilic monomer (d)
And a photopolymerization initiator (c).

The hydrophilic monomer (d) contains at least one (meth) acryloyl group in one molecule, and the hydrophilic group is a hydroxyl group, a sulfonic acid group or a sulfonic acid group. 1 molecule of base, primary, secondary, tertiary amino group or amide group, quaternary ammonium group, carboxylic acid group or carboxylate group, phosphate group or phosphate group, polyethylene glycol chain, morpholino group, sulfate group, etc. Those containing at least one are preferable.

As such a hydrophilic monomer (d),
2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycerol (meth) acrylate, 2-acrylamido-2-methylpropanesulfonic acid and salt, sodium sulfonate ethoxy (meth) acrylate, (meth) acrylamide , N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N-isopropylacrylamide, N, N-dimethylaminopropylacrylamide, 2-methacryloxyethyltrimethylammonium chloride, (meth) Acrylic acid, sodium (meth) acrylate, 2- (meth)
Acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, ω-carboxy-polycaprolactone monoacrylate, EO-modified phosphoric acid (meth) acrylate, polyethylene glycol Examples thereof include (meth) acrylate and acryloylmorpholine, and these may be used alone or in combination of two or more kinds.

As the photopolymerization initiator (c), the photopolymerization initiator used in the composition (A) is preferably used.
The amount of the photopolymerization initiator (c) used is the hydrophilic monomer (e) 1
It is preferably 0.1 to 10 parts by weight with respect to 00 parts by weight.

The composition (B) may be diluted with a solvent if necessary. In particular, when the hydrophilic monomer (d) is solid, it is preferable to use a solvent. The solvent used is preferably a polar solvent, specifically, alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol and benzyl alcohol; ketones such as acetone, methyl ethyl ketone and cyclohexanone; methyl. In addition to cellosolves such as cellosolve, ethyl cellosolve, and butyl cellosolve, ethyl acetate, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, water and the like can be mentioned.

In the second step of the production method of the present invention, the cured film of the undercoat layer formed in the first step is irradiated with actinic rays in a state where the composition (B) is brought into contact therewith and photocured. Let The photocuring reaction proceeds by the irradiation of this actinic ray, and the (meth) acryloyl group contained in the coating and the hydrophilic monomer (d) are copolymerized on the surface of the cured coating, and inside the cured coating, The crosslinking density is further improved by the polymerization reaction of the (meth) acryloyl group and the vinyl group.

Examples of the method of bringing the composition (B) into contact with the cured coating include roll coating and dipping.

The photocured film obtained in the second step is
If necessary, alkali treatment may be performed. Such an alkali treatment is particularly effective when the hydrophilic monomer (d) contains a carboxylic acid group, a sulfonic acid group or a phosphoric acid group, and a salt such as an alkali metal can be prepared by this treatment. preferable. For the alkali treatment, for example, an aqueous solution of sodium carbonate, sodium hydrogen carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide or the like, an alcohol solution, or the like is used.

The concentration of the above-mentioned alkaline solution is preferably 0.1 to 5% by weight so that the cured coating is not damaged.

It is preferable to remove excess composition (B) and unreacted composition (B) by washing with water.

The light source used for irradiation with the above-mentioned actinic rays is not particularly limited, and examples thereof include a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a xenon lamp, a low pressure sterilization lamp and the like.

[0039]

EXAMPLES Examples will be shown below, but the present invention is not limited thereto. (Example 1) First step (1) Preparation of composition (A) 5 g of γ-methacryloxypropyltrimethoxysilane (“KBM503” manufactured by Shin-Etsu Silicone Co., Ltd.), ethanol 4
g and 0.1 N-hydrochloric acid aqueous solution 1.2 g are mixed, and 40 ° C.
And hydrolyzed for 5 hours. Thereafter, 5 g of pentaerythritol triacrylate (“Karayad PET-30” manufactured by Nippon Kayaku Co., Ltd.), 0.2 g of 1-hydroxycyclohexyl phenyl ketone (“Irgacure 184” manufactured by Ciba Geigy), and 4-dimethylaminobenzoic acid were added to the solution. Ethyl (“Kayakyu EPA” manufactured by Nippon Kayaku Co., Ltd.) 0.1 g
The composition (A) was prepared by adding and making a uniform solution. (2) Coating and thermosetting The composition (A) obtained in (1) was applied to a glass plate substrate with a Meyer bar and heated at 120 ° C. for 2 hours for curing to form a cured coating film for the undercoat layer. .

Second step (3) Photocuring The cured film obtained in the step (2) is treated with the following composition (B).
After immersing in the solution, pulling it up, 2000mJ with high pressure mercury lamp
After irradiating with ultraviolet rays of / cm ² for photo-curing, the unreacted portion of the composition (B) was removed by washing with water to prepare an antifogging coated article. [Composition (B)] 75 g of water 25 g of ethanol 25 g of 2-acrylamido-2-methylpropanesulfonic acid ("TBAS-Q" manufactured by Nitto Chemical Co., Ltd.) 2.6 g of sodium carbonate 1-hydroxycyclohexyl phenyl ketone 0 0.2 g (“Irgacure 184” manufactured by Ciba-Geigy) • Ethyl 4-dimethylaminobenzoate 0.1 g (“Kayacure EPA” manufactured by Nippon Kayaku Co., Ltd.)

Example 2 In the composition (A), γ-
Instead of methacryloxypropyltrimethoxysilane,
Vinyltriethoxysilane ("KB manufactured by Shin-Etsu Silicone Co., Ltd.
E1003 ") was prepared in the same manner as in Example 1 except that 3.8 g was used.

(Example 3) The same as Example 1 except that an acrylic resin plate was used as the substrate instead of the glass plate, and the composition (A) was heated and cured at 70 ° C for 3 hours. To prepare an antifogging coated article.

(Example 4) The same procedure as in Example 1 was repeated except that a polycarbonate plate was used as the substrate instead of the glass plate, and the composition (A) was heated and cured at 70 ° C for 3 hours. To produce an antifogging coated article.

(Comparative Example 1) The following composition (A) was applied onto a glass plate base material, and the coating film was irradiated with ultraviolet rays of 2000 mJ / cm ² , and then the light-irradiated coating film was exposed to 50 ° C. It was hydrolyzed in a 1N hydrochloric acid aqueous solution to prepare an antifogging coated article. -Γ-methacryloxypropyltrimethoxysilane 5g ("KBM503" manufactured by Shin-Etsu Silicone Co., Ltd.)-Pentaerythritol triacrylate 5g ("Karayad PET-30" manufactured by Nippon Kayaku Co., Ltd.) 1-Hydroxycyclohexyl phenyl ketone 0.2g (Ciba Geigy) "Irgacure 184" manufactured by the company) ・ Ethyl 4-dimethylaminobenzoate 0.1 g ("Kayacure EPA" manufactured by Nippon Kayaku Co., Ltd.)

Comparative Example 2 An antifogging coated article was produced in the same manner as in Example 1 except that the second step was not performed at all.

Comparative Example 3 An antifogging coated article was produced in the same manner as in Example 1 except that the first step was not performed at all.

Comparative Example 4 A glass plate substrate was coated with the following composition and dried at 80 ° C. for 1 hour to prepare an antifogging coated article.・ Polyacrylic acid (25% by weight aqueous solution, manufactured by Wako Pure Chemical Industries, Ltd.) 5 g ・ Sodium dodecylbenzenesulfonate 15 g ・ Water 80 g

[0048] The performance evaluation the following evaluation per the obtained anti-fogging coated article in the above Examples and Comparative Examples of performance, and the results are shown in Table 1. (1) Anti-fogging property The anti-fogging property when cooling water is applied to one surface of an anti-fog coated article and kept at 25 ° C, and steam of 42 ° C is applied to the other surface for 3 minutes, JIS- 1st grade according to S4030
The grade was evaluated in four grades: grade 1 was marked with ⊚, grade 2 was marked with ◯, grade 3 was marked with Δ, and grade 4 was marked with x. (2) Warm water resistance After immersing the antifogging coated article in warm water at 50 ° C. for 24 hours,
The same antifogging property as in (1) was evaluated.

[0049]

[Table 1]

[0050]

The composition of the method for producing an antifogging coated article of the present invention is as described above, and provides an antifogging coated article excellent in antifogging property and hot water resistance. The obtained antifogging coated article is suitably used for lenses such as glasses and cameras, windshields of automobiles, windshields of automobiles, shields of helmets, optical articles such as underwater glasses, mirrors of bathrooms and washrooms, and the like.

Claims (1)

[Claims] 1. A plastic substrate or an inorganic substrate,
(A) a silane coupling agent represented by the following general formula (1) or a hydrolyzate of the silane coupling agent, (b) 1
A composition (A) consisting of a hydrophobic polyfunctional (meth) acrylate compound having at least two (meth) acryloyl groups in the molecule and (c) a photopolymerization initiator is applied as an undercoat layer on a substrate and heated. (D) a hydrophilic monomer containing at least one (meth) acryloyl group in one molecule, and (c) photopolymerization in the first step of curing, and the cured coating formed by the first step. A method for producing an antifogging coated article, comprising the second step of irradiating an active ray with the composition (B) comprising an initiator in contact with the composition and photocuring the composition. Embedded image (In the formula, R ^{1 to} R ³ each independently represent a halogen atom, a lower alkyl group, a lower alkoxy group or a lower acetoxy group, and at least one of R ¹ , R ² and R ³ is a halogen atom, a lower atom or a lower atom. An alkoxy group or a lower acetoxy group, and X represents a lower alkyl group having a vinyl group or a (meth) acryloyl group at the end)