JPH0578508A - Production of plastic optic having reflection-preventive effect - Google Patents

Abstract

PURPOSE:To produce a plastic optic which is excellent in scratch resistance, adhesion, wear resistance, impact resistance, chemical resistance, flexibility, heat resistance, weatherability, light resistance, dyeability, solvent impermeability, etc., and has a good reflection-preventive effect. CONSTITUTION:A plastic substrate is coated with a film consisting mainly of an organopolysiloxane and fine inorganic oxide particles obtained from at least one of silica sol, titania sol, zirconia sol, antimony oxide sol, and alumina sol. On this coating is then formed a film consisting of one or more inorganic oxides at least 10wt.% of which is silicon dioxide. A multilayered coating film composed of two or more layers is further formed on the inorganic oxide coating to produce the objective plastic optic having a reflection-preventive effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a plastic optical article having an antireflection effect suitable for optics such as spectacle lenses, camera lenses, CRT filters and optical recording substrates.

[0002]

2. Description of the Related Art Plastic molded products, especially molded products represented by plastic lenses, have been in great demand in recent years because they have extremely excellent impact resistance and transparency, are lightweight, and are easy to dye. is increasing. Traditionally,
In order to prevent reflection, a method has been performed in which a substance having a refractive index different from that of the substrate is formed on the substrate by a vacuum vapor deposition method or the like.

Japanese Unexamined Patent Publication (Kokai) No. 52-165862 proposes that a plastic molded article is provided with an organopolysiloxane resin layer, and a metal and / or inorganic ceramic layer is provided thereon.

Further, in Japanese Patent Laid-Open No. 56-113101, for the purpose of improving and improving both the surface hardness and the antireflection property of plastic, Si of about 1 micron is formed on a plastic substrate.
A method is disclosed in which O ₂ is coated by vacuum vapor deposition, and a multilayer antireflection film is further coated thereon.

Further, in Japanese Patent Laid-Open No. 59-78301, a surface of a plastic substrate is coated with an organopolysiloxane-based hard coat film containing an organosilicon compound as a main component or an epoxy resin cured film. A method of coating an antireflection film is disclosed.

[0006]

In the technique disclosed in Japanese Patent Application Laid-Open No. 52-165862, peeling of the coating film, decrease in surface hardness, and further occurrence occur because sufficiently strong adhesion cannot be obtained. There are many defects such as thick and deep scratches, and there is a problem of poor practical durability.

Further, the technique disclosed in Japanese Patent Laid-Open No. 56-11310 has high hardness and antireflection property, but on the other hand, it reduces adhesion, impact resistance, weather resistance and hot water resistance, Furthermore, there is a big problem in heat resistance.

The technique disclosed in Japanese Patent Laid-Open No. 59-78301 has an antireflection property, but on the other hand, it has poor adhesion to the substrate and is easily immersed in water, alcohol, etc. There is a big problem in the adhesion, weather resistance, etc.

The present invention provides scratch resistance, adhesion, abrasion resistance, impact resistance, chemical resistance, slidability, heat resistance, weather resistance, light resistance, dyeability, solvent penetration resistance and the like. An object of the present invention is to provide a method for producing a plastic optical article having an excellent antireflection effect.

[0010]

The present invention has the following constitution in order to achieve the above object.

That is, the present invention provides a method for producing a plastic optical article having an antireflection effect, in which the following a and b are provided in this order on the surface of a plastic substrate, and a multilayer coating having two or more layers is further provided on the coating. Then, the present invention relates to a method for producing a plastic optical article having an antireflection effect, characterized in that at least one layer of the layer B and the multilayer coating film is provided by an ion beam assist method.

As the plastic substrate in the present invention, for example, acrylic resin, polycarbonate, diethylene glycol bisallyl carbonate polymer, (halogenated) bisphenol A di (meth) acrylate polymer and its copolymer, (halogenated) bisphenol A Molded articles such as urethane-modified di (meth) acrylate polymers and copolymers thereof, for example, lenses,
Examples include sheets, films and compact discs.

The present invention comprises, on these plastic substrates, a coating comprising, as a main component, organopolysiloxane and one or more finely divided inorganic oxides selected from silica sol, titania sol, zirconia sol, antimony oxide sol and alumina sol. A hard coat layer is provided, and a typical example of the composition forming the organopolysiloxane is an organically substituted silicon compound. As such a silicon compound, there may be mentioned the following general formula (A) or a hydrolyzate thereof.

R _a R ¹ _b SiX _4-ab (A) (wherein R is an organic group having 1 to 10 carbon atoms, R ¹ is a hydrocarbon group having 1 to 6 carbon atoms or a halogenated hydrocarbon group) ,
X is a hydrolyzable group, and a and b are 0 or 1. ) Specific examples include tetraalkoxysilanes such as methyl silicate, ethyl silicate, n-propyl silicate, i-propyl silicate, n-butyl silicate, sec-butyl silicate and t-butyl silicate, and their hydrolysis. Furthermore, methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyl Triethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ-chloropropylto Silane, .gamma.-chloropropyl triethoxysilane, .gamma.-chloropropyl triacetoxy silane, .gamma.-methacryloxypropyltrimethoxysilane, .gamma.-aminopropyltrimethoxysilane, .gamma.-aminopropyltriethoxysilane, .gamma.
Mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, β-cyanoethyltriethoxysilane, methyltriphenoxysilane, chloromethyltrimethoxysilane, chloro Methyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, α
-Glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, α-glycidoxypropyltrimethoxysilane, α -Glycidoxypropyltriethoxysilane, β-glycidoxypropyltrimethoxysilane, β
-Glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltripropoxysilane, γ-glycidoxypropyltributoxysilane, γ -Glycidoxypropyltrimethoxyethoxysilane, γ-glycidoxypropyltriphenoxysilane, α-glycidoxybutyltrimethoxysilane, α-glycidoxybutyltriethoxysilane, β-glycidoxybutyltrimethoxysilane, β-
Glycidoxybutyltriethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, δ-glycidoxybutyltrimethoxysilane, δ-glycidoxybutyltriethoxysilane, (3 , 4-Epoxycyclohexyl) methyltrimethoxysilane, (3,4-epoxycyclohexyl) methyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyl Triethoxysilane, β- (3,4-
Epoxycyclohexyl) ethyltripropoxysilane, β- (3,4-epoxycyclohexyl) ethyltributoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxyethoxysilane, β- (3,4-epoxycyclohexyl) ethyl Triphenoxysilane, γ-
(3,4-epoxycyclohexyl) propyltrimethoxysilane, γ- (3,4-epoxycyclohexyl) propyltriethoxysilane, δ- (3,4-epoxycyclohexyl) butyltrimethoxysilane, δ- (3,4- Epoxycyclohexyl) butyltriethoxysilane and other trialkoxysilanes, triacyloxysilanes or triphenoxysilanes or their hydrolysates and dimethyldimethoxysilane, phenylmethyldimethoxysilane,
Dimethyldiethoxysilane, phenylmethyldiethoxysilane, γ-chloropropylmethyldimethoxysilane,
γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane,
Methylvinyldimethoxysilane, methylvinyldiethoxysilane, glycidoxymethylmethyldimethoxysilane, glycidoxymethylmethyldiethoxysilane, α-
Glycidoxyethylmethyldimethoxysilane, α-glycidoxyethylmethyldiethoxysilane, β-glycidoxyethylmethyldimethoxysilane, β-glycidoxyethylmethyldiethoxysilane, α-glycidoxypropylmethyldimethoxysilane, α-glycidoxypropylmethyldiethoxysilane, β-glycidoxypropylmethyldimethoxysilane, β-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldisilane Ethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropylmethyldimethoxyethoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ- Glycidoxypropylmethyldiacetoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, γ-glycidoxypropylvinyldimethoxysilane, γ-glycidoxypropylvinyldiethoxysilane Examples are dialkoxysilanes such as γ-glycidoxypropylphenyldimethoxysilane and γ-glycidoxypropylphenyldiethoxysilane, diphenoxysilanes or diacyloxysilanes or hydrolysates thereof.

These organosilicon compounds may be used alone or in combination.
It is also possible to add more than one species. In particular, for the purpose of imparting dyeability, it is preferable to use an organosilicon compound containing an epoxy group or a glycidoxy group, which gives a high added value.

The above composition is usually diluted with a volatile solvent and applied as a liquid composition. What is used as a solvent is not particularly limited, but it is required that the surface property of the coated object is not impaired in use, and further consideration is given to stability of the composition, wettability to a substrate, volatility, etc. Should be decided. Further, the solvent can be used not only as one kind but also as a mixture of two or more kinds.

Further, in order to improve the hardness and the adhesion to the inorganic oxide layer, the particulate inorganic oxide is contained in an amount of 5% by weight or more and 80% or more.
It is preferably contained in an amount of not more than wt%. That is, if it is less than 5% by weight, sufficiently strong adhesion strength with the coating film B cannot be obtained, and if it exceeds 80% by weight, problems such as poor adhesion with the plastic substrate, cracking of the coating film itself, and reduction of impact resistance are caused. There is. Examples of such fine-particle inorganic oxides include silica sol, titania sol, zirconia sol, antimony oxide sol, and alumina sol, which are colloidally dispersed in terms of workability and transparency.

Further, various surfactants can be used in these coating compositions for the purpose of improving the flow at the time of application, and in particular, block or graft of dimethylpolysiloxane and alkylene oxide. Copolymers and further fluorochemical surfactants are effective.

For the purpose of further improving the weather resistance, it is possible to add an ultraviolet absorber or an antioxidant as a method for improving heat resistance deterioration.

Further, an inorganic compound other than the particulate inorganic oxide may be added to these coating compositions as long as the coating performance and transparency are not significantly reduced. By using these additives together, various physical properties such as adhesion to a substrate, chemical resistance, surface hardness, durability, and dyeability can be improved. Examples of the inorganic material that can be added include metal alkoxides represented by the following general formula [I], chelate compounds and / or hydrolysates thereof.

M (OR) _m [I] (wherein R is an alkyl group, an acyl group or an alkoxyalkyl group, and m is the same as the number of charges of the metal M. M is silicon, titanium, zircon, Antimony, tantalum, germanium, aluminum, etc.) When forming the organopolysiloxane coating in the present invention, various curing agents can be used for the purpose of accelerating curing and low temperature curing. As the curing agent, various epoxy resin curing agents or various organic silicon resin curing agents are applied.

Specific examples of these curing agents include various organic acids and their acid anhydrides, nitrogen-containing organic compounds, various metal complex compounds or metal alkoxides, as well as alkali metal organic carboxylates and carbonates. Examples include various salts such as salts, and radical polymerization initiators such as peroxides and azobisisobutyronitrile. It is also possible to use a mixture of two or more of these curing agents. Among these curing agents, the following aluminum aluminum chelate compounds are particularly useful for the purpose of the present invention from the viewpoints of stability of coating materials and prevention of coloration of coating films after coating.

The aluminum chelate compound as used herein is an aluminum chelate compound represented by the general formula AlX _n Y _3-n (where X is OL (L is a lower alkyl group) and Y is the general formula M ¹ COCH ₂ COM ² (M ¹ ,
M ² is a lower alkyl group, a ligand derived from a compound represented by the general formula M ³ COCH ₂ COOM ⁴
(M ³ and M ⁴ are both lower alkyl groups) is at least one selected from the ligands derived from the compound, and n is 0, 1 or 2. ).

Among the aluminum chelate compounds represented by AlX _n Y _3-n , aluminum acetylacetonate and aluminum bisethylacetate are preferred from the viewpoints of solubility in the composition, stability, and effect as a curing catalyst. Acetate monoacetylacetonate, aluminum-
Di-n-butoxide-monoethylacetoacetate, aluminum-di-iso-propoxide-monomethylacetoacetate and the like are preferable. It is also possible to use a mixture of two or more thereof.

As a coating method, a method used in ordinary coating work can be applied, but for example, dip coating, flow coating method, spin coating method and the like are preferable. The coating composition thus applied is dried by heating,
Or cured.

As a heating method, hot air or infrared rays can be used. The heating temperature should be determined depending on the substrate to be applied and the coating composition used, but usually room temperature to 250 ° C, more preferably 35 to 200 ° C is used. If the temperature is lower than this, curing or drying tends to be insufficient, and if the temperature is higher than this, thermal decomposition, cracking and the like occur, and further problems such as yellowing are likely to occur.

In applying the liquid coating composition of the present invention, it is preferable that the surface to be applied is cleaned. During cleaning, dirt is removed with a surfactant, degreasing with an organic solvent, and freon. Steam cleaning is applied. In addition, various pretreatments are also effective means for improving adhesion and durability. Particularly preferably used methods are the below-mentioned activated gas treatment and chemical treatment with acid, alkali or the like depending on the concentration.

The film thickness of the coating film containing the organopolysiloxane and the fine-particle inorganic oxide as the main components in the present invention is not particularly limited. However, from the viewpoints of maintaining adhesion strength, hardness, etc., it is preferably used between 0.1 micron and 20 microns.

Particularly preferably, it is 0.4 to 10 microns.

In the present invention, a coating film made of an inorganic oxide containing at least 10% by weight of silicon dioxide is provided on these hard coat layers.
As pretreatment, activated gas treatment, chemical treatment or the like may be performed. The activated gas treatment is generated ions, electrons, or excited gas under normal pressure or reduced pressure. As a method of generating these activated gases, for example, corona discharge, high-voltage discharge by direct current under reduced pressure, low frequency, high frequency, or microwave is used. In particular, a treatment with low temperature plasma obtained by high frequency discharge under reduced pressure is preferably used from the viewpoint of reproducibility and productivity. The gas used here is not particularly limited, but specific examples include oxygen, nitrogen, hydrogen, carbon dioxide, sulfur dioxide, helium, neon, argon, freon, water vapor, ammonia, carbon monoxide, chlorine, Examples thereof include nitric oxide and nitrogen dioxide. These can be used not only as one kind but also as a mixture of two or more kinds.

Oxygen is mentioned as a preferable gas in the above, and it may be one existing in the natural world such as air. Particularly preferably, pure oxygen gas is effective for improving the adhesion. Further, for the same purpose, it is possible to raise the temperature of the treated substrate during the treatment. Among them, the pretreatment with the activated gas is particularly effective. When applying such an activated gas, the treatment conditions are:
It should be optimized depending on the composition for forming the organopolysiloxane, the type of the inorganic oxide fine particles, the curing conditions, the film thickness, the presence or absence of dyeing, etc., and should be determined experimentally.

In the present invention, liquid coating or dry coating such as vacuum deposition is effective in providing a coating film made of an inorganic oxide substance of which at least 10% by weight is silicon dioxide, and in particular, the film density and productivity are improved. From the viewpoint of the above, dry coating such as vacuum deposition is preferably used. Specific examples of inorganic oxides other than silicon dioxide that can be used in combination include colloidal oxides such as titania sol, zirconia sol, antimony oxide sol, and alumina sol in liquid coating, and the above-mentioned general formula, M (OR). Examples thereof include products obtained from the metal alkoxide represented by m and / or its hydrolyzate. It is possible to use not only one of these substances but also a mixture of two or more thereof. In dry coating, preferably used inorganic oxides other than silicon dioxide are SiO,
ZrO ₂ , Al ₂ O ₃ , TiO, TiO ₂ , Ti
₂ O ₃ , Y ₂ O ₃ , Yb ₂ O ₃ , MgO, Ta ₂ O ₅ ,
CeO ₂ , HfO _{2 and the} like can be mentioned. It is possible to use not only one of these substances but also a mixture of two or more thereof. The film thickness of such a coating is not particularly limited. However, from the viewpoint of hardness and heat resistance, it is preferably used between 0.01 micron and 1 micron. Particularly preferably, it is 0.02 to 0.5 micron. In particular, a coating film made of a mixed substance of SiO ₂ and ZrO ₂ is effective for improving the light fastness of the dyed plastic substrate. Also,
Upon co-evaporation, it is effective to add Y ₂ O _{3 and the} like in combination.

In the present invention, two or more multi-layered films are provided on the above-mentioned coating layer made of an inorganic oxide substance containing 10% by weight or more of silicon dioxide. Specific examples of the substance to be formed are as described above. A combination of the above inorganic oxides is preferably used.

Examples of the method for forming such a layer include a vacuum vapor deposition method, an ion beam assist method, a sputtering method and an ion plating method. In the present invention, a layer containing 10% by weight or more of silicon dioxide is used. ,
At least one layer of the antireflection multilayer coating is provided by the ion beam assist method. The plastic optical article having an antireflection effect obtained by the present invention is more than a general plastic antireflection optical article.
It has high hardness, high heat resistance, and is resistant to chemicals. Therefore, eyeglass lenses, camera lenses, CRT filters, and especially 10% by weight of silicon dioxide.
Since the coating film containing the above has a gas barrier property, it can be preferably used for an optical recording substrate.

[0035]

EXAMPLES In order to describe in more detail, examples will be described below, but the present invention is not limited thereto.

The performance of the obtained optical article having an antireflection effect was tested according to the following method. The results are shown in Table 1.

(B) Using steel wool having a hardness of # 0000, the coated surface was rubbed 50 times under a load of 1.5 kg, and the degree of scratches was judged. The criteria are: A ... No scratches.

B ... Many scratches are generated.

(B) Adhesiveness 100 pieces of crevices reaching the substrate of 1 mm are put on the surface of the coating with a steel knife from the top of the coating, and cellophane adhesive tape (trade name "Cellotape" manufactured by Nichiban Co., Ltd.) is strongly attached. , 90
It was peeled off rapidly in the direction of the angle and examined for the presence or absence of peeling of the coating film.

(C) Appearance The obtained optical article having an antireflection effect was observed with the naked eye for its transparency, colorability, and presence of cracks.

(D) Heat resistance After being placed in an oven set at 70 ° C. for 1 hour, it was taken out and observed for cracks.

Example 1 (1) Preparation of transparent substrate for coating Tetrabrom bisphenol A ethylene oxide 2
70 parts by weight of a monomer containing a polyfunctional acrylate monomer to which 0.9 mol of hexamethylene diisocyanate is added and 30 parts by weight of styrene are added to 1 mol of a hydroxyl group-containing compound obtained by esterifying 1 mol of acrylic acid to a mol addition product. The substrate obtained by cast polymerization using isopropyl peroxide as a polymerization initiator was subjected to low-temperature plasma treatment to obtain a surface-treated substrate. The refractive index of the obtained resin was 1.6.

(2) Preparation of coating composition (a) Preparation of γ-glycidoxypropyltrimethoxysilane hydrolyzate γ-glycidoxypropyltrimethoxysilane 95.3 wt% in a reactor equipped with a rotor Part is charged and the liquid temperature is 10
℃ and stirred with magnetic stirrer
21.8 parts by weight of a 01N hydrochloric acid aqueous solution is gradually added dropwise.
After completion of the dropping, cooling was stopped to obtain a hydrolyzate of γ-glycidoxypropyltrimethoxysilane. (B) Preparation of coating composition The silane hydrolyzate was mixed with 216 parts by weight of methanol, 216 parts by weight of dimethylformamide, 0.5 parts by weight of a fluorosurfactant, bisphenol A type epoxy resin (trade name Epicoat manufactured by Shell Chemical Co., Ltd.). 827) 67.5 parts by weight are added and mixed, and colloidal antimony pentoxide sol (trade name: Antimonzol A-255 manufactured by Nissan Chemical Industries, Ltd.)
270 parts by weight of 0 average particle diameter 60 mμ) and 13.5 parts by weight of aluminum acetylacetonate were added and sufficiently stirred to obtain a coating composition.

(3) The coating composition prepared in (2) above is immersed in the substrate to be coated obtained in (1) above at a pulling rate of 10 cm / min, and heat curing is performed at 8
Preliminary curing was performed at 2 ° C for 12 minutes, and further heated at 100 ° C for 4 hours.

(4) The hard-coated plastic substrate obtained in (3) above was immersed in a disperse dye bath containing red, blue and yellow and having a liquid temperature of 93 ° C., and dyeing was carried out for 5 minutes. The extinction ratio of the obtained dyed product was 50%.

(5) On the dyed hard coat plastic substrate obtained in the above (4), ZrO ₂ which is an inorganic oxide substance is added.
And SiO ₂ mixture (ZrO ₂ / SiO ₂ = 50/5
0 (weight ratio)), ZrO ₂ , Ta ₂ O ₅ , and SiO ₂ in the order of the optical film thickness by λ / 4, λ / 4, λ / 4, λ / 4 (λ = 521 nm) for multi-layer coating on both sides. The reflection interference color of the obtained optical article having an antireflection effect was yellowish green. The dyed antireflection plastic substrate thus obtained was wrapped on one side with aluminum foil, and a fade meter (manufactured by Suga Test Instruments Co., Ltd.) was used to perform a lightfastness-promoting test. It had no fading and had good light fastness.

[0047]

[0048]

The plastic optical article having an antireflection effect obtained by the present invention has the following effects.

(1) A high-hardness coating film capable of withstanding multiple abrasions such as steel wool can be obtained.

(2) Excellent adhesion.

(3) It has excellent heat resistance and hot water resistance.

(4) The durability of the dyed product is excellent.

(5) It has excellent gas barrier properties and durability of dyed products.

(6) Excellent solvent resistance.

Claims (4)

[Claims] 1. A method for producing a plastic optical article having an antireflection effect, which comprises the steps (1) and (2) shown below in this order on a surface of a plastic substrate, and further comprising a multi-layer coating of two or more layers on the coating. (2) A method for producing a plastic optical article having an antireflection effect, characterized in that at least one of the multilayer coating and the multilayer coating is provided by an ion beam assist method. I. A film containing an organopolysiloxane as a main component and one or more fine particle inorganic oxides selected from silica sol, titania sol, zirconia sol, antimony oxide sol and alumina sol. A coating consisting of at least 10% by weight of an inorganic oxide which is silicon dioxide 2. The method for producing a plastic optical article having an antireflection effect according to claim 1, wherein the organopolysiloxane is an organosilicon compound represented by the following general formula (A). R _a R ¹ _b SiX _4-ab (A) (wherein R is an organic group having 1 to 10 carbon atoms, R ¹ is a hydrocarbon group having 1 to 6 carbon atoms or a halogenated hydrocarbon group, X
Is a hydrolyzable group, and a and b are 0 or 1. ) 3. The production of a plastic optical article having an antireflection effect according to claim 1, wherein the organopolysiloxane is a hydrolyzate of an organosilicon compound represented by the following general formula (A). Method. R _a R ¹ _b SiX _4-ab (A) (wherein R is an organic group having 1 to 10 carbon atoms, R ¹ is a hydrocarbon group having 1 to 6 carbon atoms or a halogenated hydrocarbon group, X
Is a hydrolyzable group, and a and b are 0 or 1. ) 4. The particulate inorganic oxide comprises 5% by weight or more and 8
The method for producing a plastic optical article having an antireflection effect according to claim 1, wherein the content is 0% by weight or less.