JPH04110918A - Optical component - Google Patents

Abstract

PURPOSE:To improve the rubbing flaw resistance, transparency, and shock resistance by applying and curing a coating composition which contains a specific organic silicon compound or its hydrolysis compound and specific titanium oxide particulates which are coated with cerium particulates. CONSTITUTION:The coating composition which contains the organic silicon compound expressed by a formula I or its hydrolysis compound and titanium oxide particulates of 1 - 200mmu in particle size coated with potassium particulates is applied and cured. In the formula, R<1> and R<2> are organic groups with an alkyl group, an alkenyl group, an allyl group, an acyl group, or a halogen group, a glycideoxy group, an epoxy group, an amino group, a phenyl group, a mercapto group, a methacryloxy group, or a cyano group, R<2> is an alkyl group, an alkoxy, an acyl group, or a phenyl group with a carbon number of 1 - 8, and (a) and (b) are '0' or '1'. Consequently, a cured film with the superior rubbing flaw resistance, transparency, and contactness is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical component having excellent scratch resistance, adhesion, impact resistance, and transparency.

[Conventional technology]

Optical components with a cured film on a plastic base material such as diethylene glycol bisallyl carbonate resin (generally called CR-39 resin) are well known. For example, JP-A No. 63-10640 discloses an optical component in which a coating liquid containing an organosilicon compound and colloidal silica is applied and cured on a plastic lens to form a cured film. The publication describes an optical component in which a coating liquid containing an organosilicon compound and titanium oxide fine particles is coated on a plastic lens and cured to form a cured film, and JP-A-63-223701 discloses an optical component in which a coating liquid containing an organosilicon compound and titanium oxide fine particles is applied and cured to form a cured film. An optical component is disclosed in which a coating liquid containing a bissilane compound, cerium oxide fine particles, and colloidal silica is applied and cured to form a cured film.

[Problem to be solved by the invention]

In the optical component disclosed in JP-A-63-10640, the cured film has a refractive index of about 1.50. When the above-mentioned cured film is formed on a high refractive index plastic lens, since the refractive index of the cured film is lower than that of the high refractive index plastic lens, interference fringes are observed, which is practically preferable for use as an eyeglass lens, for example. It has no problems.

In addition, a cured film obtained from a coating composition containing an organosilicon compound and titanium oxide fine particles disclosed in JP-A No. 63-225635 turns blue as the titanium oxide fine particles are reduced over time by irradiation with ultraviolet rays. It has a tendency to become colored, which poses a problem that is undesirable from a fashion point of view when it is used, for example, as an eyeglass lens.

Furthermore, a cured film obtained from a coating composition containing a bissilane compound, cerium oxide, and silica fine particles disclosed in JP-A No. 63-223701 has poor scratch resistance and insufficient transparency. Moreover, since the cured film itself tends to be colored yellow, there is a practical problem when using it as an eyeglass lens, for example.

The present invention was made to solve these problems, and its purpose is to provide excellent scratch resistance, transparency, and impact resistance, as well as adhesion to optical component substrates and antireflection coatings on cured films. It is an object of the present invention to provide a novel optical component which is of good quality and in which appearance defects such as interference fringes are hard to be observed even when used as a lens for spectacles.

[Failure to solve the problem]

As a result of intensive research to achieve the above-mentioned object, the present inventors have found that (A) general formula % formula % () (where R1 and R1 are respectively an alkyl group, an alkenyl group, an aryl group, An acyl group, a halogen group, a glycidoxy group, an epoxy group, an amino group, a phenyl group, a mercapto group, a methacryoxy group, or an organic group having a cyano group; R2 is an alkyl group having 1 to 8 carbon atoms, an alkoxy group, an acyl group; group, phenyl group, a and b are 0 or I
It is. ) or a hydrolyzate thereof and (B) a particle size l~200 coated with cerium oxide fine particles.
The present inventors have discovered an optical component characterized by having a cured film formed by coating and curing a coating composition containing millimicron titanium oxide fine particles, resulting in the present invention.

The present invention will be explained in detail below.

The general formula used as component (A) in the present invention is % () (where R1 and R1 are each an alkyl group, an alkenyl group, an aryl group, an acyl group, or a halogen group, a glycidoxy group, an epoxy group, an amino group, An organic group having a phenyl group, a mercapto group, a methacrioxy group, or a cyano group, R2 is an alkyl group having 1 to 8 carbon atoms, an alkoxy group, an acyl group, a phenyl group, a and b are an atom or an I
It is. ) Examples of the organosilicon compounds or their hydrolysates include methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltripropoxysilane, methyltributoxysilane, Ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ-
Chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltripropoxysilane, 3,3.3-)lifluoroprobyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-gly cydoxybrobyltriethoxysilane,
γ-(βglycidoxyethoxy)propyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltriethoxysilane, γ-methacryloxypropyltri Methoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane,
γ-Mercaptopropyltriethoxysilane, N-β(
trialkoxy or triazyloxysilanes such as aminoethyl)-γ-aminopropyltrimethoxysilane, β-cyanoethyltriethoxysilane, and dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyljethoxysilane, phenylmethyljethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyljethoxysilane, γ-glycidoxypropylphenyldimethoxysilane, γ-glycidoxypropylphenyldiethoxysilane, γ-chloro Propylmethyldimethoxysilane, γ
-Chloropropylmethyljethoxysilane, dimethyldiacetoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyljethoxy Examples include dialkoxysilanes or diacyloxysilanes such as silane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyljethoxysilane, methylvinyldimethoxysilane, and methylvinyljethoxysilane.

The titanium oxide fine particles coated with cerium oxide fine particles used as component (B) in the present invention and having a particle size of 1 to 200 millimicrons are used in the form of a colloidal solution dispersed in water, an organic solvent, or a mixed solvent thereof. This is to improve the refractive index and scratch resistance of the cured film. Examples of organic solvents for dispersing titanium oxide fine particles coated with cerium oxide fine particles include alcohols such as methanol, ethanol, and isopropyl alcohol, cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve, and dimethyl formamide. Can be mentioned.

The particle size of the titanium oxide fine particles is 1 to 200 millimicrons, particularly preferably 5 to 50 millimicrons. Particle size is 1
Particles smaller than millimicrons lack stability;
Particle diameters exceeding 200 millimicrons are undesirable since there is a problem that the cured film lacks transparency.

The amount of titanium oxide coated with cerium oxide fine particles is such that the ratio of solid content of titanium oxide fine particles coated with cerium oxide fine particles/amount of organosilicon compound or its hydrolyzate used is 1150 to 1O/1. preferable. When the ratio is l150, the refractive index of the cured film becomes low and the effect of addition is small.

Moreover, if it exceeds 10/1, cracks are likely to occur between the cured film and the substrate, and furthermore, there is a greater possibility that transparency will be lowered.

It is also possible to use a curing agent in the coating composition used in the present invention to accelerate the reaction and cure it at low temperatures. Examples of curing agents include amines such as allylamine and ethylamine, or various acids and bases including Lewis acids and bases, such as organic carboxylic acids, chromic acid, hypochlorous acid, boric acid, bromic acid, and selenite. acids, thiosulfuric acid, orthosilicic acid, thiocyanic acid, nitrous acid, aluminic acid,
Examples include metal salts such as carbonic acid and perchloric acid, alkoxides such as aluminum, zirconium, and titanium, and complex compounds thereof.

In addition, the coating composition used in the present invention is coated with metals such as aluminum, antimony, zirconium, tin, tungsten, and silicon in order to match the refractive index with the optical member serving as the substrate and to further improve scratch resistance. A particulate inorganic substance consisting of an oxide may be added.

Various surfactants can be added to the coating composition used in the present invention for the purpose of improving wettability during application and improving smoothness of the cured film. Further, ultraviolet absorbers, antioxidant M, etc. can also be used as long as they do not affect the physical properties of the cured film.

As the coating means, commonly used methods such as dipping, spinning, and spraying can be used, but dipping and spinning are particularly preferred from the viewpoint of surface precision.

The coating composition used in the present invention is cured by hot air drying,
This is carried out by irradiation with active energy rays, preferably 70
It is preferable to carry out in hot air at a temperature of .degree. C. to 200.degree. C. (particularly preferably 90.degree. C. to 150.degree. C.).Active energy rays include far infrared rays, and damage caused by heat can be suppressed to a low level.

Furthermore, before applying the coating composition used in the present invention to the optical member substrate, chemical treatment with acids, alkalis, various organic solvents, physical treatment with plasma and ultraviolet rays, cleaning treatment with various detergents, and furthermore, various resin treatments are performed. The adhesion between the base material and the cured film can be improved by performing the primer treatment using.

Optical members that can be coated and cured with the cured film obtained according to the present invention are not particularly limited as long as they do not impair transparency, but examples include methyl methacrylate homopolymer,
Copolymers containing methyl methacrylate and one or more other monomers as monomer components, diethylene glycol bisallyl carbonate homocopolymers, copolymers containing diethylene glycol bisallyl carbonate and one or more other monomers as monomer components Synthetic resins such as synthetic resins, polycarbonate, polystyrene, polyvinyl chloride, polyethylene terephthalate, and polyurethane, and inorganic glasses may be mentioned.

The multilayer antireflection film provided on the cured film is formed by alternately laminating low refractive index and high refractive index films, and the high refractive index film at this time includes a titanium oxide film, an aluminum oxide film, and a tantalum oxide film. , zirconium oxide film, etc., but from the viewpoint of transparency, durability, etc., a mixed vapor deposited film of metal oxides containing tantalum, zirconium, and yttrium is particularly preferred. In addition, examples of the low refractive index include a magnesium fluoride film, but it is particularly preferable to use a silicon dioxide (Sin2) film from the viewpoint of scratch resistance, heat resistance, and the like.

A mixed vapor deposition film of metal oxides containing tantalum, zirconium and yttrium is obtained by mixing zirconium oxide (ZrCL) powder and tantalum oxide (T a 20s) powder,
Preferably, the material is made into pellets by pressure pressing and sintering, and then vapor-deposited by electron beam heating. The composition ratio of the mixed raw material obtained by mixing each powder is Z
rO2! .

0, TazOi is 0.8 to 1.8, y.

, is preferably 0.05 to 0.3.

The mixed metal vapor deposited film obtained in this way is Ta*oh
Similarly, it is chemically extremely stable compared to ZrO*, and has transparency comparable to ZrOx. Furthermore, it exhibits a high refractive index of, for example, 2°05, which is effective from the viewpoint of film design.

In addition, TazOi is 0.8 for 1 mol of Zr0z.
If the amount is less than 1.8 mol or more than 1.8 mol, absorption tends to occur in the absorption film in the mixed vapor deposited film obtained, and Y*O- is 0.
．． If it is less than 15 mol, absorption tends to occur in the mixed vapor deposited film obtained, and if it exceeds 0.3 mol, the vapor deposition rate becomes faster and absorption tends to occur in the obtained mixed vapor deposited film, and the vapor deposition raw materials tend to scatter. This is not preferred because it is difficult to control.

The film structure of the multilayer anti-reflection coating is a two-layer film of λ7'2-λ/4, λ, 2'4-λ/4-λ/'4 or λ7'4λ/
Although it is practical to use a three-layer film of '2-λ/4,
A multilayer film of four or more layers is also possible from the viewpoint of reflective properties. Here, λ/4 of the first JI counting from the substrate side of the three-layer film
The film was 31 using the above mixed vapor deposition film and a SiO2 film.
It may be a one-symmetric equivalent film or a two-layer composite equivalent film.

Furthermore, in forming the multilayer anti-reflection film, instead of the above-mentioned vacuum evaporation method, a method such as a sputtering method using a similar sintered body as a target material or an ion-blating method can also be used.

Furthermore, the optical component of the present invention may be subjected to antistatic treatment, shoulder treatment, etc., if necessary.

In addition to eyeglass lenses, the optical component of the present invention can be used for camera lenses, optical filters attached to word processor displays, automobile window glasses, and the like.

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited to these Examples. Note that all parts in the examples are based on weight.

[Example 1] (Production of plastic lens) 100 parts by weight of m-xylylene diisocyanate, 142 parts by weight of pentaerythritol tetrakis 3-mercaptopropionate, 6 parts by weight of di-n-butyl phosphate, and 0.25 parts by weight of dibutyltin dilaurate. and 0.5 parts by weight of 2-(2'-hydroxy-5°-t-octylphenyl)benzotriazole as an ultraviolet absorber were mixed and thoroughly stirred, followed by deaeration for 60 minutes under a vacuum of lmmHg.

Next, the mixed solution was poured into a mold consisting of a glass lens mold and a resin gasket, and heated at 25°C for 12 hours.
The temperature was raised continuously to 0°C over 20 hours, then 120°C.
Polymerization was carried out by holding at °C for 2 hours. After polymerization, the gasket was removed and the lens mold and lens were separated to obtain a plastic lens.

The obtained plastic lens has nd=1.592, sid
It had good optical properties of -36.

(Adjustment of coating liquid) In a glass container equipped with a magnetic stirrer (A
) 42 parts by weight of γ-glycidoxypropyltrimethoxysilane was added, and while stirring, 0.01N hydrochloric acid was added! 4 parts by weight was added dropwise. After the dropwise addition was completed, the mixture was stirred for 24 hours to obtain a hydrolyzed product. Next, 200 parts by weight of methanol-dispersed titanium oxide particles (solid content 2096, average particle diameter 15 mm) coated with cerium oxide particles as component (B), and 2 parts by weight of isopropyl alcohol as a solvent were added.
0 parts by weight, 80 parts by weight of ethyl cellosolve, 1 part by weight of a silicone surfactant as a lubricant, and 3 parts by weight of aluminum acetylacetonate as a hardening agent were added, and after thorough stirring, the mixture was filtered to obtain a coating liquid.

(Formation of cured film) The plastic lens (refractive index nc11.592, ν
d36) was immersed in a 5% NaOH aqueous solution at 45°C for 3 minutes to thoroughly wash it, and then coated with the Day-Tub method (pulling speed 14 cm/min) using the coating solution prepared in the above manner. ) and heated at 120° C. for 3 hours to form a cured film, and the following evaluations were performed.

(1) Scratch Resistance Test The lens surface was rubbed with #0000 steel wool, and the scratch resistance was visually judged. The judgment criteria were as follows.

A...Strong (hardly scratched even if rubbed B...severe scratches if rubbed too hard C...scratches similar to the lens board) (2) Presence of interference fringes Visually inspected under fluorescent light The judgment criteria are as follows.

A... Interference fringes are hardly visible B... A little visible C... Quite visible (3) q! ! Adhesion test The surface of a plastic lens with a cured film was 10 mm apart at 1 mm intervals.
A cross cut was made at 0, and a cellophane tape was firmly attached, and then rapidly peeled off to check the presence or absence of a cured film. Those that did not peel were rated as ○, and those that peeled were rated as ×.

(4) Impact resistance test Using a flat plate with a center thickness of 1.6 m+, drop a 16 gI1 ball from a height of 127 an into the center of the flat plate, F
A steel ball drop test based on the DA standard was conducted to examine the presence or absence of damage to the lens. Those that were not damaged were rated O1, and those that were damaged were rated X.

(5) Transparency test In a dark room under fluorescent light, the lenses were visually inspected to see if they were cloudy. The criteria for judgment are as follows.

A: Hardly visible clouding B: Slightly visible C: Quite visible The plastic lens with the cured film of this example has good scratch resistance and adhesion, no visible interference fringes, and is transparent. It was confirmed that this lens also has excellent performance characteristics.

[Example 2] All except that 70 parts by weight of γ-glycidoxypropylmethyldimethoxysilane was used instead of 42 parts by weight of γ-glycidoxypropyltrimethoxysilane used in component (A) in Example 1. The same procedure as in Example 1 was carried out. As shown in Table 1, the evaluation results confirmed that the lens had excellent scratch resistance, adhesion, interference fringes, and transparency, similar to Example 1.

[Example 3] Example! Instead of 42 parts by weight of γ-glycidoxypropyltrimethoxysilane used in component (A), β-(3
, 4epoxycyclohexyl)ethyltriethoxysilane and 12 parts by weight of methyltrimethoxysilane were used. As shown in Table 1, the evaluation results are the same as in Example 1, including scratch resistance, adhesion,
It was confirmed that the lens has excellent interference fringes and transparency.

[Comparative Example 1] 135 parts by weight of methanol-dispersed colloidal silica (solid content 30%, average particle diameter 15 mm) was used instead of the titanium oxide fine particles coated with cerium oxide fine particles of component (B) used in Example 1. Everything was carried out in the same manner as in Example 1 except for using the following. As a result, as shown in Table 1, interference fringes were generated and the appearance was unfavorable.

(Margin below) Table 1 [Example 4] A multilayer antireflection film was formed on the plastic lens obtained in Example 1 as follows.

(Formation of multilayer anti-reflection film) 5JO2 sintered body was used as the vapor deposition raw material for the base layer and the low refractive index film, and ZrO2 powder, Ta20i powder and Y2O powder were used as the vapor deposition raw material for the mixed vapor deposition film which is the high refractive index film.
, the powders were mixed at a molar ratio of 1:1.30.2, pressed, and then sintered at 1200°C to form a pellet, and a plastic lens with a cured film provided by the method described above was made. The mixture was placed in a vapor deposition tank, heated to 85°C without evacuation, and evacuated to 2 x 10-'' Torr.The above vapor deposition raw materials were vapor-deposited using an electron beam heating method to form a silicon compound as shown in Table 2. a base layer consisting of a base layer consisting of a 1J low refractive index film consisting of a composite equivalent film of a mixed vapor deposited film and a silicon compound film, a 1J2 high refractive index film consisting of a mixed vapor deposited film, and a third low refractive index film consisting of a silicon oxide. A multilayer antireflection film having a film structure formed by sequentially depositing refractive index films was obtained.

Note that the base layer is used to improve adhesion to the substrate.

(The following is a blank space) Table 2 *The first layer low refractive index film is a composite sotho-equivalent film.

Table 3 shows the measurement results of the absorption rate in the visible light wavelength range of the plastic lens with the multilayer antireflection film obtained in this way. In addition, the absorption coefficient (96) in Table 3 is 380 to 780n of the plastic lens with multilayer antireflection coating.
The reflectance (R) and transmittance (T) in the m wavelength range are
Measured using Utate Seisakusho Model 340 self-recording spectrophotometer, 1
It was calculated by converting it into 00-(R+T).

As is clear from Table 3, the plastic lens with the multilayer antireflection film obtained in Example 4 exhibits low absorption over the entire wavelength range of visible light and has excellent optical properties. confirmed.

In addition, the results of measuring the appearance, luminous reflectance, scratch resistance, impact resistance, adhesion, heat resistance, alkali resistance, and acid resistance of the plastic lens with multilayer antireflection film obtained in Example 4 are shown. 4. From Table 4, it was confirmed that the plastic lens with multilayer antireflection film of Example 4 had good results in all items, and was also excellent in mechanical properties and chemical properties.

Table 3 *Raw material composition ratio represents the raw material composition ratio of the mixed vapor deposited film used as the high refractive index film constituting the multilayer antireflection film.

[Comparative Example 2] Instead of the titanium oxide fine particles coated with the cerium oxide fine particles of component (B) used in Example 1, 150 parts by weight of methanol-dispersed titanium oxide sol (solid content 2096, average particle size 20 millimicrons) was used. All except those used were those of Example 4.
I did the same thing. As a result, the product was colored blue in the outdoor exposure test, which was unfavorable in terms of appearance.

[Comparative Example 3] Water-dispersed cerium oxide (solid content 30%, average particle size 5 millimicrons) was used instead of the titanium oxide fine particles coated with cerium oxide fine particles of component (B) used in Example I.
The same procedure as in Example 4 was carried out except that parts by weight were used.

As a result, the cured film was colored and had insufficient transparency.

The evaluation methods for appearance, luminous reflectance, scratch resistance, impact resistance, adhesion, alkali resistance, acid resistance, and outdoor exposure in Table 4 were as follows.

(1) Exterior Visually check the following 1) using a lighting device with a fluorescent lamp as the light source.
- 4) were observed, and those that satisfied all of these were evaluated as good, and those that did not satisfy any of these were evaluated as poor.

I) It must be transparent 2) There should be no irregularity on the surface 3) It must not be colored 4) There should be no foreign matter or scratches on the surface (2) Luminous reflectance Used with Hitachi Model 340 self-recording spectrophotometer , 380-7
The reflectance in the 80 nIn wavelength range was measured, and the luminous reflectance was calculated from this reflectance and the luminous efficiency curve.

(3) Scratch Resistance Test The surface of the multilayer antireflection film was rubbed with steel wool #0000, and the scratch resistance was visually judged.

The judgment criteria were as follows.

A... There is almost no scratch even if you rub it hard B... You get a lot of scratches if you rub it hard C... You get the same scratches as the lens board (4) Scratch resistance test Center thickness is 1.6 mm FD using a flat plate and dropping a 16 g steel ball from a height of 127 cm onto the center of the flat plate.
Based on the A standard (a steel ball drop test was performed, the presence or absence of damage to the lens was checked. Those that were not damaged were rated ○, and those that were damaged were rated ×.

(5) Adhesion test The surface of a plastic lens with a multilayer antireflection film is cross-cutted 100 times at 1 mm intervals, and cellophane tape is firmly attached, then rapidly peeled off to remove the multilayer antireflection film, base layer, and hard coat film. The presence or absence of H was examined, and those that did not release were rated O, and those that peeled were rated ×.

(6) Heat Resistance Test A plastic lens with a multilayer antireflection film deposited on the cured film was heated in an oven for 1 hour, and the presence or absence of cracks was examined. The heating temperature started at 70°C and was increased in 5°C increments, and superiority or inferiority was determined based on the temperature at which cracks occur.

(7) Alkali resistance test A plastic lens with a multilayer antireflection film was immersed in an iowt% NaOH aqueous solution for 24 hours, and the state of erosion on the surface of the multilayer antireflection film was observed. was marked as ×.

(8) Acid resistance test 10ifto6HC1 aqueous solution and l Owt%Ht
A plastic lens with a multilayer antireflection film was immersed in the S 04 aqueous solution for 24 hours, and the state of erosion on the surface of the multilayer antireflection film was observed. Those with no erosion change were rated ○, and those with erosion change were rated ×.

(9) Outdoor exposure test: Leave exposed outdoors for one month, and if there is no change in appearance, ○
, Those with changes were marked as ×.

(The following is a blank space) [Effects of the Invention] As described above, according to the present invention, a cured film using titanium oxide fine particles coated with cerium oxide has excellent scratch resistance, transparency, and adhesion. , even when coated on high refractive index plastic lenses for eyeglasses.
It has become possible to match the refractive index of the film to the refractive index of a high refractive index plastic lens, making it possible to provide an optical component in which interference fringes are less likely to occur.

Furthermore, when an antireflection film is applied on a cured film, it has become possible to obtain an optical component with good alkali resistance, acid resistance, and impact resistance.

Claims (3)

[Claims] (1) On the optical member, (A) General formula (R^1)a(R^3)bSi(OR^2)4-(a+
b) (where R^1 and R^3 are each an alkyl group, an alkenyl group, an aryl group, an acyl group, a halogen group, a glycidoxy group, an epoxy group, an amino group, a phenyl group, a mercapto group, a methacryloxy group, or an organic group having a cyano group, R^2 is an alkyl group having 1 to 8 carbon atoms, an alkoxy group, an acyl group, a phenyl group, a and b are 0 or 1) or a hydrate thereof An optical component characterized by having a cured film formed by coating and curing a coating composition containing a decomposition product and (B) titanium oxide fine particles having a particle size of 1 to 200 millimicrons coated with cerium oxide fine particles. (2) The optical component according to claim 1, further comprising a multilayer antireflection film on the cured film. (3) The optical component according to claim 1 or 2, wherein the optical member is a lens for spectacles.