JPH07149520A - Coating composition - Google Patents

Abstract

PURPOSE:To obtain an optical part having a colorless transparent coating film with excellent refractive index and light resistance by coating the surface of titanium oxide particles with zinc oxide, applying a coating agent containing the obtained composite titanium oxide particles to the surface of an optical part and curing the coating layer on the optical part. CONSTITUTION:Titanium oxide sol having particle diameter of 5-100nm is produced by the hydrolysis of a titanium alkoxide or titanium salt solution. A zinc compound is added and mixed to the sol and a base is added to the mixture to effect the precipitation of zinc oxide on the surface of the titanium oxide particles and obtain a composite titanium oxide sol having a particle diameter of 10-120nm. The objective coating composition is produced by compounding the sol with a film-forming substance consisting of a compound expressed by formula (R<1>)a(R<2>)bSi(OR<3>)4-a-b (R<1> and R<2> are an alkyl, an alkenyl, allyl, a halogen, epoxy group, etc.; R<3> is H or a 1-4C alkyl; a and b are 0-2) and/or its hydrolyzed product. An optical part having a coating film is produced by applying the composition to an optical substrate and curing the composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition that can be used as a hard coating agent, an ultraviolet absorbing coating agent, an antireflection coating agent for optical parts, a sol contained in the coating composition, and the coating. The present invention relates to optical components coated with the composition, such as spectacle lenses, camera lenses, optical filters attached to displays of word processors, automobile window glasses, and the like.

[0002]

2. Description of the Related Art Titanium oxide is a substance having the highest refractive index among various metal oxides, and it is applied as a sol to the surface of a transparent substrate such as glass or plastic to form a coating, thereby forming glass or plastic. It is known that the surface hardness, the ultraviolet absorption property, the antireflection property, etc. can be improved. As the coating film containing titanium oxide, for example, a coating film containing titanium oxide particles and an organic silicon compound (Japanese Patent Laid-Open No. 63-225635).
(Japanese Patent Laid-Open No. 264902), a hard coat film composed of composite oxide fine particles of titanium oxide and cerium oxide and an organic silicon compound (JP-A-2-264902), and composite oxide fine particles of titanium oxide and iron oxide and organic silicon. A hard coat film composed of a compound (Japanese Patent Laid-Open No. 5-2102) and the like are known. In all of these, a coating film is formed from a mixture of titanium oxide and a specific compound, and the characteristics of the coating film are improved.

However, since titanium oxide itself is a photocatalyst, when it is used in contact with or mixed with an organic substance, there is a problem that the organic substance is decomposed by irradiation of ultraviolet light. For example, Japanese Patent Laid-Open No. 63-2256
The coating produced by the method of JP-A No. 35-35 is inferior in light resistance, and there is a problem that discoloration or deterioration of the film occurs when exposed to sunlight, especially ultraviolet rays for a long time.

In order to solve such problems, attempts have been made to reduce the photocatalytic activity of the titanium oxide particles contained in the coating agent. For example, as a surface treatment for the purpose of improving light resistance, titanium oxide was coated with aluminum oxide-titanium oxide, aluminum oxide-silicon oxide, or the like, and the catalytic activity points were sealed to improve light resistance (A.
W. Evans, Paint Technology, Volume 26, Issue 16, 1962
Years). The surface of the titanium oxide particles disclosed in this report is densely coated with a coating substance, and it is considered that this coating inhibits the catalytic action of titanium oxide. However, since the absorption of the coating material near the absorption edge wavelength of titanium oxide is small, when the composite particles were irradiated with ultraviolet light near the absorption edge of titanium oxide, the light resistance of the coating film was not sufficient. . Japanese Patent Laid-Open No. 4-110918 discloses titanium oxide fine particles coated with cerium oxide fine particles, but this publication does not teach or suggest the light resistance of a coating film containing titanium oxide fine particles.

[0005]

The present inventors have found that a coating film containing fine particles of titanium oxide coated with fine particles of cerium oxide exhibits excellent light resistance, but at the same time, a coating film having a high refractive index is formed. To form
It has been found that when a large amount of coating is performed with a gel containing the composite particles, a problem occurs that the coating film is colored yellow. In addition, JP-A-2-264902
The cerium oxide-containing coating film described in Japanese Unexamined Patent Publication also has a problem that it is colored in yellow as well.
Since the iron oxide-containing coating film described in Japanese Patent No. 2102 is colored reddish brown, it cannot be used as a colorless and transparent hard coat. In particular, with regard to eyeglass lenses, those colored yellow tend to be disliked by consumers, and the degree of coloring of the lenses colored yellow is reduced by a method called brewing. Therefore, the spectacle lens having such a colored coating film, particularly a yellow colored coating film, is extremely inferior in value as a product.

Therefore, according to the present invention, the photocatalytic activity is reduced without deteriorating the high refractive property of titanium oxide, thereby imparting excellent refraction and light resistance to the formed coating film and coating a large amount thereof. Even in any case, it is an object to provide a titanium oxide-containing coating composition capable of forming a colorless and transparent coating film in the visible region. Another object of the present invention is to provide a titanium oxide-containing sol contained in the coating composition having the above properties.

[0007]

The present inventor has made diligent efforts to solve the above problems, and as a result, a coating which has sufficient absorption characteristics near the absorption edge wavelength of titanium oxide and is colorless and transparent in the visible region. It has been found that zinc oxide is very suitable as the substance. Further, when the titanium oxide particles are coated with zinc oxide, the photocatalytic property of titanium oxide can be sufficiently suppressed with a very small amount of coating, so that the coating film formed by the coating agent containing the titanium oxide particles described above is It has been found that while maintaining high refractivity, it is colorless and transparent in the visible region and has extremely excellent light resistance. The present invention has been completed based on the above findings.

That is, the present invention provides a composite titanium oxide particle characterized in that a zinc oxide coating is provided on the surface of the titanium oxide particle. According to an embodiment of the present invention, the titanium oxide particles have a particle diameter of 5 to 100 nm, the titanium oxide composite particles have a particle diameter of 10 to 120 nm, and the composite titanium oxide particles. A sol containing is provided. Further, (a) a step of producing a gel in which titanium oxide particles are dispersed in alcohols by hydrolysis of a titanium alkoxide or a titanium salt solution, (b) a step of adding a zinc compound to the gel, and (c) Zinc oxide is deposited on the surface of titanium oxide particles by adding a base to the mixture obtained in the above step (b) or performing a hydrolysis reaction to form a zinc oxide coating on the surface of the titanium oxide particles. There is provided a method for producing the sol, which comprises the steps.

Further, according to the present invention, there is provided a coating composition, which comprises (a) the composite titanium oxide particles according to claim 1.
And (b) Formula: (R ¹ ) _a (R ² ) _b Si (OR ³ ) _4-ab (wherein
R ¹ and R ² represent a functional group having an alkyl group, an alkenyl group, an allyl group, a halogen group, an epoxy group, an amino group, a mercapto group, a methacryloxy group, a cyano group, an aryl group, or an acyl group, and R ³ is A coating composition comprising a film-forming substance which is a compound represented by hydrogen or an alkyl group having 1 to 4 carbon atoms, and a and b are integers of 0 to 2) and / or a hydrolyzate thereof. And a coating composition comprising a sol containing the composite titanium oxide particles and a film-forming material described above. Further, according to the present invention, there is provided an optical component having a coating film formed by applying and curing the above coating composition. According to an aspect of the present invention, there is provided the above optical component having a coating film that is colorless in the visible region.

The composite titanium oxide particles of the present invention are characterized in that a zinc oxide coating is provided on the surface of the titanium oxide particles. For example, a sol containing the titanium oxide particles forming the core portion was produced. Then, it can be produced by depositing zinc oxide, which is a coating substance, on the surface of titanium oxide particles. The above method is a step of producing a gel in which titanium oxide particles are dispersed in an alcohol by hydrolysis of a titanium alkoxide or a titanium salt solution, (b) a step of adding a zinc compound to the gel, and (c) Zinc oxide is deposited on the surface of titanium oxide particles by adding a base to the mixture obtained in the above step (b) or performing a hydrolysis reaction to form a zinc oxide coating on the surface of the titanium oxide particles. It includes a process.

The sol containing titanium oxide particles can be produced, for example, by a method such as hydrolysis of titanium alkoxide or hydrolysis of titanium salt solution, but a commercially available titanium oxide sol may be used. The particle size of titanium oxide particles contained in the above sol is preferably in the range of 5 to 100 nm. If the particle size is 5 nm or less, the sol may become unstable, and if it is 100 nm or more, the particle size becomes large after coating with zinc oxide, and the transparency of the finally obtained sol may decrease.

As a starting material for obtaining the titanium oxide particles, for example, a solvent-soluble titanium compound may be used. As the titanium alkoxide, for example, methoxide,
Ethoxide, normal propoxide, isopropoxide, normal butoxide, isobutoxide and the like can be used, and examples of the titanium salt include chloride, iodide, bromide, nitrate, sulfate, acetate, oxalate, and citric acid. Salts, tartrates and the like can be used. Examples of other titanium compounds include chelate compounds such as titanium diisopropoxybisacetylacetonato and titanium diisopropoxybisethylacetoacetate, and acylates such as tri-n-butoxytitanium monostearate. Among these, the produced sol which is good for the hydrolysis of titanium alkoxide is preferable in that the particle size of titanium oxide particles is fine and the particle size is uniform.

Solvents used for producing the sol containing titanium oxide particles include water; alcohols such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, normal butyl alcohol and isobutyl alcohol; tetrahydrofuran, diethyl ether and the like. Examples thereof include ethers; esters such as methyl acetate, ethyl acetate, propyl acetate and butyl acetate; polyhydric alcohols such as ethylene glycol and glycerin; cellosolves such as ethyl cellosolve and cellosolve acetate. These solvents may be used alone or in combination of two or more. Generally, the titanium compound may be dissolved in these solvents so as to be 0.01 to 20% by weight to carry out the hydrolysis reaction.

In producing a sol containing titanium oxide particles, it is preferable to add a polymer dispersant because the stability of the sol is increased. As the polymer dispersant, for example, a cellulose derivative can be used, and examples thereof include hydroxypropyl cellulose, hydroxyethyl cellulose, ethyl cellulose, methyl cellulose, carboxymethyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl ethyl cellulose, benzyl cellulose, acetyl cellulose, nitrocellulose. , Cellulose acetate phthalate, cellulose acetate butyrate and the like. The polymer dispersant is preferably added before the titanium oxide is precipitated from the titanium compound, and should be added before the precipitated titanium oxide particles are fused or aggregated.

To coat the surface of titanium oxide particles with zinc oxide used as a coating substance, a solution containing a zinc compound soluble in a solvent is prepared, and zinc oxide is precipitated from the solution on the surface of titanium oxide particles. Good. As a zinc compound,
Chloride, iodide, bromide, nitrate, sulfate, acetate,
Salts such as oxalate, citrate and tartrate; chelates such as diisopropoxybisacetylacetonate and diisopropoxybisethylacetoacetate; methoxide, ethoxide, normal propoxide, isopropoxide, normal butoxide, Examples thereof include alkoxides such as isobutoxide, and among these zinc compounds, those soluble in the reaction solvent may be appropriately selected and used. To produce a sol containing composite titanium oxide particles, a solution of a zinc compound is added to and mixed with the titanium oxide sol, and then a base is added to the mixture or a hydrolysis reaction is performed to form a titanium oxide particle on the surface of the titanium oxide particles. It suffices to deposit zinc oxide.

The composite titanium oxide particles produced as described above have zinc oxide coating on the surface of the titanium oxide particles, and the particle size is preferably in the range of generally 10 to 120 nm. . If the particle size is 10 nm or less, the obtained sol may become unstable, and if it is 120 nm or more, the particle size becomes large after being covered with a coating substance, and the transparency of the finally obtained sol may decrease. . The lower the concentration of the zinc compound in the reaction solution, the finer the particle size of the composite titanium oxide particles obtained. However, the concentration of the zinc compound in the reaction solution depends on the solvent evaporation method or the ultrafiltration method. It can be adjusted by any method such as. Generally, 0.01
It is preferable to use a zinc compound solution having a concentration of about 10% by weight to 10% by weight.

According to the present invention, (a) the above composite titanium oxide particles, and (b) the formula: (R ¹ ) _a (R ² ) _b Si (OR ³ ).
_4-ab (wherein R ¹ and R ² are functional groups having an alkyl group, an alkenyl group, an allyl group, a halogen group, an epoxy group, an amino group, a mercapto group, a methacryloxy group, a cyano group, an aryl group, or an acyl group. Group, R ³ represents hydrogen or an alkyl group having 1 to 4 carbon atoms, and a and b are integers of 0 to 2) and / or a hydrolyzate thereof. A composition is provided.
Generally, the coating composition is prepared by mixing a sol containing the composite titanium oxide particles with a film forming agent.

In the film forming agent represented by the above general formula, R ¹ and R ² are effectively functional groups having adhesiveness to a substrate such as plastic. The alkoxy group represented by OR ³ is
It is hydrolyzed by water to form a -Si-O-Si- bond, which has the function of forming a film. When the carbon number of R ³ is 5 or more, the molecular weight of the alcohol produced by hydrolysis becomes large, so that it is difficult to remove the alcohol and the denseness of the film may be deteriorated, which is not preferable. General formula R ¹ _a
Specific examples of the compound represented by R ² _b Si (OR ³ ) _4-ab include:
Tetramethylsilane, tetraethylsilane, tetra-n-
Propylsilane, tetraisopropylsilane, tetra-n
-Butylsilane, tetra-sec-butylsilane, tetra-t
-Butylsilane, dimethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldi-n-propoxysilane, diisopropyldiisopropoxysilane, di-n-
Butyldi-n-butyloxysilane, di-sec- Butyldi-sec
-Butyloxysilane,

Di-t-butyldi-t-butyroxysilane, methyloctadecyldimethoxysilane, methyldodecyldiethoxysilane, methyloctadecyldiethoxysilane, n-octylmethyldimethoxysilane, n-octylmethyldiethoxysilane, methyltrimethoxysilane, Methyltriethoxysilane, Methyltri-n-propoxysilane, Methyltriisopropoxysilane, Methyltri-n
-Butyloxysilane, Methyltri-sec- Butyloxysilane, Methyltri-t-butyloxysilane, Ethyltrimethoxysilane, Ethyltriethoxysilane, Ethyltri-n
-Propoxysilane, ethyltriisopropoxysilane, ethyltri-n-butyroxysilane, ethyltri-sec
-Butyloxysilane, ethyltri-t-butyloxysilane, n-propyltrimethoxysilane, isobutyltrimethoxysilane, n-hexyltrimethoxysilane, hexadecyltrimethoxysilane, n-octyltrimethoxysilane, n-dodecyltrimethoxysilane, n- Octadecyltrimethoxysilane, n-propyltriethoxysilane,
Isobutyltriethoxysilane, n-hexyltriethoxysilane, hexadecyltriethoxysilane, n-octyltriethoxysilane, n-dodecyltriethoxysilane, n-octadecyltriethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, dibenzyl Dimethoxysilane,

Dibenzyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, benzyltrimethoxysilane, benzyltriethoxysilane, 3-acetoxypropyltrimethoxysilane, 3-acetoxypropyltriethoxysilane, allyltrimethoxysilane, Allyltriethoxysilane, 4-aminobutyltriethoxysilane, (aminoethylaminomethyl) phenethyltrimethoxysilane, N- (2-aminoethyl) -3-
Aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyltrimethoxysilane,
6- (aminohexylaminopropyl) trimethoxysilane, p-aminophenyltrimethoxysilane, p-aminophenyltriethoxysilane, 3-aminopropyltrimethoxysilane,

3-aminopropyltriethoxysilane, ω
-Aminoundecyltrimethoxysilane, aminotriethoxysilane, bis- (2-hydroxyethyl) -3-aminopropyltriethoxysilane, 8-bromooctyltrimethoxysilane, bromophenyltrimethoxysilane, 3-bromopropyltrimethoxysilane Silane, n-bromotrimethoxysilane, 2-chloromethyltriethoxysilane, chloromethylmethyldiethoxysilane, chloromethylmethyldiisopropoxysilane, p- (chloromethyl) phenyltrimethoxysilane, chloromethyltriethoxysilane,
Chlorophenyltriethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 2- (4-chlorosulphonylphenyl) ethyltrimethoxysilane, 2-cyanoethyltriethoxy Silane,
2-cyanoethyltrimethoxysilane, cyanomethylphenethyltriethoxysilane, 3-cyanopropyltriethoxysilane, 2- (3-cyclohexenyl) ethyltrimethoxysilane, (cyclohexylaminomethyl) methyldiethoxysilane, (3-cyclopenta Dienylpropyl) triethoxysilane,

(N, N-diethyl-3-aminopropyl) trimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, (3-glycidoxypropyl)
Methyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 1,2,3,4,7,7-hexachloro-6 -Methyldiethoxylyl-2-norbornene, 1,2,3,4,7,7-hexachloro-6-triethoxysilyl-2-norbornene, 3-iodopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, (Mercaptomethyl) methyldiethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane,

3-methacryloxypropyltriethoxysilane, methyl [2- (3-trimethoxysilylpropylamino) ethylamino] -3-propionate, 7-octynyltrimethoxysilane, RN-α-phenethyl-N'- Triethoxysilylpropyl urea, SN-α-phenethyl-N'-
Triethoxysilylpropylurea, phenethyltrimethoxysilane, N-phenylaminopropyltrimethoxysilane, phenylvinyldiethoxysilane, 3-thiocyanatopropyltriethoxysilane, (tridecafluoro-1,1,2,2-tetrahydro Octyl) triethoxysilane, N- [3- (triethoxysilyl) propyl] phthalamic acid, (3,3,3-trifluoropropyl) methyldimethoxysilane, 3,3,3- (trifluoropropyl) trimethoxysilane , 1-trimethoxysilyl-2- (chloromethyl) phenylethane, 2- (trimethoxysilyl) ethylphenylsulfonyl azide, β-trimethoxysilylethyl-2
-Pyridine, trimethoxysilylpropyldiethylenetriamine, N-[(3-trimethoxysilyl) propyl] ethylenediaminetriacetic acid sodium salt, N- (3-trimethoxysilylpropyl) pyrrole, vinylmethyldiethoxysilane, vinyltris-t-butoxy Silane etc. can be mentioned. However, the compound of the above general formula used in the present invention is not limited to the above specific examples.

One of the compounds represented by the above general formula may be used, or any two or more of them may be mixed and used. Further, in order to improve the film forming property, a hydrolyzate of the compound represented by the above general formula may be used. For the hydrolysis of the above compound, pure water is added and mixed, or hydrochloric acid,
Acidic water added with acid such as nitric acid, sulfuric acid, acetic acid, oxalic acid, citric acid, tartaric acid as a catalyst, or base such as ammonia, sodium hydroxide, potassium hydroxide, monoethanolamine, diethanolamine, triethanolamine as a catalyst The added basic water may be added and stirred. The degree of progress of hydrolysis can be adjusted by controlling the amount of water added, but in general, the amount of water added is
It is desirable that the amount is equimolar or more to the hydrolyzable group of the compound to be hydrolyzed. Further, in the hydrolysis of the above compound, a solvent such as alcohol may be added for the purpose of homogenizing the reaction system of the hydrolysis.

In general, the compounding ratio of the compound titanium oxide particles to the compound represented by the above general formula or its hydrolyzate is preferably 1/50 to 10/1 in terms of solid content. If the ratio is 1/50, the refractive index of the cured film may not be sufficiently high, and if it exceeds 10/1, cracks may occur between the coating film and the substrate, or transparency may deteriorate, which is not preferable. . In the coating composition of the present invention, fine particles made of a metal oxide such as aluminum, antimony, zirconium, tin, tungsten, or silicon are used in order to match the refractive index with the optical component serving as the substrate and further improve the scratch resistance. Inorganic substances may be added. Further, various surfactants can be added for the purpose of improving wettability at the time of application and improving smoothness of the cured film. Further, an ultraviolet absorber, an antioxidant and the like can be added to the extent that they do not affect the physical properties of the coating film.

The above coating composition may be applied onto a substrate which is an optical material by a dipping method, a spin coating method, a spraying method or the like and cured. From the viewpoint of surface accuracy and the like, it is preferable to apply by a dipping method or a spin method. Before applying the coating composition to the optical component as the base material, the surface of the optical component is chemically treated with an acid, an alkali, or various organic solvents; a physical treatment with plasma or ultraviolet rays; a washing treatment with various detergents; or various By applying a primer treatment using a resin, the adhesion between the base material and the cured film can be improved. Curing of the coating composition may be generally carried out by heat treatment, for example, hot air drying or irradiation with active energy rays. It is preferable to cure in hot air at 70 ° C to 200 ° C, and particularly preferable to cure at 90 ° C to 150 ° C. Far infrared rays or the like can be used as the active energy ray, and damage due to heat can be suppressed to a low level.

In curing the coating film by heating, in order to shorten the heating time or to cure at low temperature,
Various curing catalysts may be added to the coating composition. Examples of the curing catalyst include amine agents such as allylamine and ethylamine, and various acids and bases including Lewis acids and Lewis bases such as organic carboxylic acids, chromic acid, hypochlorous acid, boric acid, bromic acid, selenious acid. Examples thereof include metal salts such as thiosulfuric acid, orthosilicic acid, thiocyanic acid, nitrous acid, aluminic acid, carbonic acid and perchloric acid, alkoxides such as aluminum, zirconium and titanium, and complex compounds thereof.

According to the present invention, there is provided an optical component having a coating film formed by applying and curing the above coating composition. The optical member as a base material is not particularly limited as long as it does not impair the transparency, and examples thereof include a methyl methacrylate homopolymer, a copolymer containing methyl methacrylate and one or more other monomers as a monomer component, and diethylene glycol bisallyl. A homopolymer of carbonate, a copolymer of diethylene glycol bisallyl carbonate and at least one other monomer as a monomer component, a transparent synthetic resin such as polycarbonate, polystyrene, polyvinyl chloride, polyethylene terephthalate, polyurethane, or an inorganic glass. Can be used. As the optical component, for example, a spectacle lens,
Examples thereof include a lens for a camera, an optical filter attached to a display of a word processor, a window glass of an automobile, and the like.

Further, vacuum deposition method, sputtering method,
Alternatively, an antireflection film may be further formed on the surface layer of the coating film by an ion plating method or the like.
As the multilayer antireflection film provided for such a purpose,
An antireflection film including a low refractive index layer and a high refractive index layer alternately laminated can be given. As the high refractive index layer, a titanium oxide film, an aluminum oxide film, a tantalum oxide film, a zirconium oxide film or the like can be used, but from the viewpoint of transparency, durability, etc., a metal oxide containing tantalum, zirconium and yttrium. What used the mixed vapor deposition film of 1 is especially preferable. Examples of the low refractive index layer include a magnesium fluoride film and the like, but it is particularly preferable to use a silicon dioxide (SiO ₂ ) film from the viewpoint of scratch resistance, heat resistance and the like.

As a mixed vapor deposition film of metal oxide containing tantalum, zirconium and yttrium, zirconium oxide (ZrO ₂ ) powder and tantalum oxide (Ta ₂ O ₅ ) powder are mixed,
Pelletized by pressure press or sintering,
Those deposited by the electron beam heating method are preferable.
The mixing ratio (molar ratio) of each powder is Ta ₂ O relative to ZrO ₂ 1.0.
It is preferably ₅ 0.8 to 1.8 and Y ₂ O ₃ 0.05 to 0.3. When Ta ₂ O ₅ is less than 0.8 mol or more than 1.8 mol with respect to 1 mol of ZrO ₂ , absorption may easily occur in the obtained mixed vapor deposition film, and Y ₂ O ₃ is 0.15 mol. If it is less than the same, absorption may easily occur in the mixed vapor deposition film obtained in the same manner, and if Y ₂ O ₃ exceeds 0.3 mol, the vapor deposition rate becomes faster, and absorption tends to occur in the obtained mixed vapor deposition film. It is not preferable because the raw material is likely to be scattered and its control may be difficult. A mixed metal deposited film obtained by, as with Ta ₂ O _5, is chemically very stable compared with ZrO _2, and and has transparency comparable to ZrO _2. Further, the refractive index shows a high value of 2.05, for example, which is effective from the viewpoint of film design.

The film structure of the above-mentioned multilayer antireflection film is generally a two-layer film of λ / 2-λ / 4, λ / 4-λ / 4-λ / 4 or λ.
A three-layer film of / 4-λ / 2-λ / 4 is preferable, but a multilayer film of four or more layers may be used in view of the use of reflection characteristics.
In the case of a three-layer film, as the first λ / 4 film counted from the substrate side, a three-layer symmetric equivalent film using the above mixed vapor deposition film and SiO ₂ film or a two-layer composite equivalent film is used. be able to. Further, the optical component of the present invention may be subjected to antistatic treatment, light control treatment, etc., if necessary. Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0032]

【Example】

Example 1 Titanium isopropoxide (2.24 g, 8.0 × 10 ^-3 mol) and hydroxypropyl cellulose (150 cp) (0.04 g) were dissolved in absolute ethanol (300 ml) and stirred with a magnetic stirrer at room temperature to give 0.57 ml. A mixture of (3.2 × 10 ^-2 mol) distilled water and 100 ml absolute ethanol was added dropwise.
Titanium isopropoxide was hydrolyzed to obtain a slightly turbid, almost transparent titanium oxide sol. Particle size observation was performed using a scanning electron microscope, and it was confirmed that the particle size of titanium oxide was 60 nm. To the obtained sol, add 2 × 10 ^-4 mol of zinc chloride and dissolve it.
1.8 ml of an aqueous solution of H10 in sodium hydroxide was added to deposit zinc oxide on the surface of titanium oxide particles. From the same particle size observation as above, the particle size of zinc oxide coated titanium oxide was 80 nm.
Was found to be The sol containing the composite titanium oxide particles was concentrated to a solid content concentration of 8% by weight by a rotary evaporator to obtain a white translucent sol.

A film-forming agent solution was prepared by diluting 1.96 g of 3-glycidoxypropyltrimethoxysilane with 8 ml of ethanol, adding 0.45 ml of an aqueous hydrochloric acid solution having a pH of 4 and sufficiently hydrolyzing at room temperature. did. The above sol and the film forming agent solution were thoroughly mixed to obtain a coating composition.
No sedimentation was observed in this coating composition, and there was almost no change with time even after standing for 1 month, and the coating composition was excellent in stability. On the surface of the base material polymethylmethacrylate, the above coating composition was applied by spin coating at 2000 rpm,
Then, a curing treatment was performed at 120 ° C. for 30 minutes to manufacture an optical component. The refractive index of the coating film measured by an ellipsometer (wavelength 633 nm) was 1.55. 20 with xenon lamp
There is no change in the visible light spectrum even after irradiation for 0 hours,
The coating film had excellent light resistance.

Example 2 By the same method as in Example 1, a white translucent sol having a solid content concentration of 8% by weight was obtained. Dilute 0.98 g of 3-glycidoxypropyltrimethoxysilane with 4 ml of ethanol and adjust to pH 4
0.22 ml of aqueous hydrochloric acid solution was added and sufficiently hydrolyzed at room temperature to prepare a film forming agent solution. The above sol and the film forming agent solution were thoroughly mixed to obtain a coating composition. No sedimentation was observed in this coating composition, and there was almost no change with time even after standing for 1 month, and the coating composition was excellent in stability. An optical component was manufactured in the same manner as in Example 1 using the base material polymethylmethacrylate and the above coating composition. The refractive index of the coating film measured by an ellipsometer (wavelength 633 nm) was 1.57. Even after irradiation with a xenon lamp for 200 hours, there was no change in the visible light spectrum, and the coated film was excellent in light resistance.

Example 3 In the same manner as in Example 1, a white translucent sol having a solid content concentration of 0.8% by weight was obtained. A film-forming agent solution was prepared by diluting 1.96 g of 3-glycidoxypropyltrimethoxysilane with 8 ml of ethanol, adding 0.45 ml of a hydrochloric acid aqueous solution having a pH of 4 and sufficiently hydrolyzing the mixture at room temperature. The above sol and the film forming agent solution were thoroughly mixed to obtain a coating composition. No sedimentation was observed in this coating composition, 1
The coating composition was excellent in stability with almost no change with time even after being allowed to stand for 10 months. An optical component was manufactured in the same manner as in Example 1 using the base material polymethylmethacrylate and the above coating composition. The refractive index of the coating film measured by an ellipsometer (wavelength 633 nm) is
It was 1.53. Even after irradiation with a xenon lamp for 200 hours, the visible light spectrum did not change, and the coating film had excellent light resistance.

Example 4 4.48 g (1.6 × 10 ^-2 mol) of titanium isopropoxide and 0.08 g of hydroxypropylcellulose (150 cp) were dissolved in 300 ml of absolute ethanol and stirred at room temperature with a magnetic stirrer. A mixture of 1.14 ml (6.4 × 10 ^-2 mol) of distilled water and 100 ml of absolute ethanol was added dropwise to hydrolyze titanium isopropoxide. 4 × 10 in this sol
^{-Add 4} moles of zinc chloride, dissolve and mix well,
3.6 ml of an aqueous sodium hydroxide solution having a pH of 10 was added to deposit zinc oxide on the surface of titanium oxide particles. The resulting sol was concentrated by a rotary evaporator to a solid content concentration of 16% by weight to obtain a white translucent sol.

A film forming agent solution was prepared by diluting 0.98 g of 3-glycidoxypropyltrimethoxysilane with 4 ml of ethanol, adding 0.22 ml of an aqueous hydrochloric acid solution having a pH of 4 and sufficiently hydrolyzing at room temperature. . The above sol and the film forming agent solution were thoroughly mixed to obtain a coating composition. No sedimentation was observed in this coating composition, and there was almost no change with time even after standing for one month, and the coating composition was excellent in stability. Example 1 using the substrate polymethylmethacrylate and the above coating composition
An optical component was manufactured in the same manner as in. The refractive index of the coating film measured by an ellipsometer (wavelength 633 nm) is 1.61.
Met. Even after irradiation with a xenon lamp for 200 hours, the visible light spectrum did not change, and the coating film had excellent light resistance.

Comparative Example 1 2.24 g (8.0 × 10 ^-3 mol) of titanium isopropoxide and 0.04 g of hydroxypropyl cellulose (150 cp) were dissolved in 300 ml of absolute ethanol and stirred at room temperature with a magnetic stirrer. A mixture of 0.57 ml (3.2 × 10 ^-2 mol) of distilled water and 100 ml of absolute ethanol was added dropwise to hydrolyze titanium isopropoxide to obtain a slightly turbid, almost transparent titanium oxide sol. From the particle size observation with a scanning electron microscope, it was confirmed that the particle size of titanium oxide was 60 nm. The sol was concentrated by a rotary evaporator to a solid content concentration of 4% by weight to obtain a white translucent sol.

1.96 g of 3-glycidoxypropyltrimethoxysilane was diluted with 8 ml of ethanol, 0.45 ml of an aqueous hydrochloric acid solution having a pH of 4 was added, and it was sufficiently hydrolyzed at room temperature to prepare a film forming agent solution. The above sol and the film forming agent solution were thoroughly mixed to obtain a coating composition. The surface of the substrate polymethylmethacrylate was spin coated with the above coating composition at 2000 rpm and then 120
An optical component was manufactured by performing a curing treatment at 30 ° C. for 30 minutes. After irradiation with a xenon lamp for 200 hours, whitening of the film was observed.

Comparative Example 2 2.24 g (8.0 × 10 ^-3 mol) of titanium isopropoxide and 0.04 g of hydroxypropylcellulose (150 cp) were dissolved in 300 ml of absolute ethanol and stirred at room temperature with a magnetic stirrer. Add a mixture of 0.57 ml (3.2 x 10 ^-2 mol) of distilled water and 100 ml of absolute ethanol dropwise.
Titanium isopropoxide was hydrolyzed to obtain a slightly turbid, almost transparent titanium oxide sol. 2 × 10 ^{-4 in} this sol
Mole zinc chloride was added and dissolved and mixed. The sol was concentrated by a rotary evaporator to a solid content concentration of 4% by weight to obtain a white semitransparent sol.

1.96 g of 3-glycidoxypropyltrimethoxysilane was diluted with 8 ml of ethanol, 0.45 ml of an aqueous hydrochloric acid solution having a pH of 4 was added, and the solution was sufficiently hydrolyzed at room temperature to prepare a film forming agent solution. The above sol and the film forming agent solution were thoroughly mixed to obtain a coating composition. Although spin coating was performed on the surface of the base material, polymethylmethacrylate, at 2000 rpm, a large crystal of zinc chloride was deposited.
A film with low transparency was obtained.

Comparative Example 3 1.96 g of 3-glycidoxypropyltrimethoxysilane was diluted with 8 ml of ethanol, and 0.45 ml of a hydrochloric acid aqueous solution having a pH of 4 was diluted.
Was added and sufficiently hydrolyzed at room temperature to prepare a film forming agent solution. Then, a film-forming agent solution was added to a methanol dispersion of titanium oxide fine particles coated with cerium oxide fine particles.
10 ml (described in JP-A-4-110918; cerium oxide / titanium oxide = 1: 1, solid content concentration 10%) was added and mixed sufficiently to obtain a coating composition. The surface of a substrate, polymethylmethacrylate, was spin-coated with the above coating composition at 2000 rpm, and then cured at 120 ° C. for 30 minutes to manufacture an optical component. The coating film of this optical component was not yellowish. After 200 hours of irradiation with a xenon lamp, the film was colored a deep dark green color.

[0043]

Since the composite titanium oxide particles of the present invention are coated with zinc oxide having sufficient absorption characteristics in the vicinity of the absorption edge wavelength of titanium oxide, the photocatalytic property of titanium oxide is sufficiently suppressed, Provides a coating film with excellent light resistance. Further, since zinc oxide can suppress the titanium oxide photocatalyst with a very small amount of coating, the ratio of titanium oxide in the composite titanium oxide particles can be increased, and the high refractive index of titanium oxide is not impaired. Moreover, zinc oxide is colorless in the visible range, and can be incorporated in a large amount in the coating composition to form a colorless and transparent high refractive index coating film. The optical component of the present invention is useful because it has a colorless high-refractive index coating film in the visible region.

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[Procedure amendment]

[Submission date] January 21, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 4

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

That is, the present invention provides a composite titanium oxide particle characterized in that a zinc oxide coating is provided on the surface of the titanium oxide particle. According to an embodiment of the present invention, the titanium oxide particles have a particle diameter of 5 to 100 nm, the titanium oxide composite particles have a particle diameter of 10 to 120 nm, and the composite titanium oxide particles. A sol containing is provided. Further, (a) a step of producing a sol in which titanium oxide particles are dispersed in alcohols by hydrolysis of a titanium alkoxide or titanium salt solution, (b)
A step of adding a zinc compound to the sol , and (c) a base is added to the mixture obtained in the above step (b) or a hydrolysis reaction is performed to precipitate zinc oxide on the surface of the titanium oxide particles. There is provided a method for producing the above sol, which comprises the step of forming a zinc oxide coating on the surface of the titanium oxide particles.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

The composite titanium oxide particles of the present invention are characterized in that a zinc oxide coating is provided on the surface of the titanium oxide particles. For example, a sol containing the titanium oxide particles forming the core portion was produced. Then, it can be produced by depositing zinc oxide, which is a coating substance, on the surface of titanium oxide particles. The above method is a step of producing a sol in which titanium oxide particles are dispersed in an alcohol by hydrolysis of a titanium alkoxide or a titanium salt solution, (b) a step of adding a zinc compound to the sol , and (c) Zinc oxide is deposited on the surface of titanium oxide particles by adding a base to the mixture obtained in the above step (b) or performing a hydrolysis reaction to form a zinc oxide coating on the surface of the titanium oxide particles. It includes a process.

Claims (8)

[Claims] 1. Composite titanium oxide particles, characterized in that a zinc oxide coating is provided on the surface of the titanium oxide particles. 2. The composite titanium oxide particles according to claim 1, wherein the titanium oxide particles have a particle diameter of 5 to 100 nm, and the titanium oxide composite particles have a particle diameter of 10 to 120 nm. 3. A sol containing the composite titanium oxide particles according to claim 1. 4. The following steps: (a) a step of producing a gel in which titanium oxide particles are dispersed in alcohols by hydrolysis of a titanium alkoxide or titanium salt solution; (b) addition of a zinc compound to the gel On the surface of the titanium oxide particles by precipitating zinc oxide on the surface of the titanium oxide particles by adding a base to the mixture obtained in the above step (b) or performing a hydrolysis reaction. The method for producing a sol according to claim 3, further comprising a step of forming a zinc oxide coating on the sol. 5. A coating composition comprising: (a) composite titanium oxide particles according to claim 1, and (b) a formula: (R ¹ ).
_a (R ² ) _b Si (OR ³ ) _4-ab (in the formula, R ¹ and R ² are alkyl group, alkenyl group, allyl group, halogen group, epoxy group, amino group, mercapto group, methacryloxy group, cyano Base,
Represents a functional group having an aryl group or an acyl group, R ³
Represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and a and b are integers of 0 to 2) and / or a hydrolyzate of the film-forming material. object. 6. A coating composition comprising: (a) the sol of claim 3 and (b) the formula: (R ¹ ) _a (R ² ) _b Si (O
R ³ ) _4-ab (wherein R ¹ and R ² are an alkyl group, an alkenyl group,
Allyl group, halogen group, epoxy group, amino group, mercapto group, methacryloxy group, cyano group, aryl group,
Or a functional group having an acyl group, R ³ represents hydrogen or an alkyl group having 1 to 4 carbon atoms, and a and b are 0 to 2
A coating composition comprising a film-forming substance which is a compound represented by the formula) and / or a hydrolyzate thereof. 7. An optical component having a coating film formed by applying and curing the coating composition according to claim 5 or 6. 8. The optical component according to claim 8, which has a colorless coating film in the visible region.