JPS63191101A - Transparent molding having surface film - Google Patents

Abstract

PURPOSE:To increase the hardness of a film having a non-glare property and to improve the durability thereof by providing a film which contains a vehicle and fine antimony pentaoxide particles having a specific average particle size and is formed with aggregate having a specific average diameter in the extreme surface part on the surface of a transparent base material. CONSTITUTION:This molding has the film which contains the vehicle and fine antimony pentaoxide particle having 1-200nm average particle size and is formed with the aggregate having 0.1-10mum average diameter in the extreme surface part thereof on the surface of the transparent base material. The trans parent base material is a substrate selected from inorg. glass and plastic. Said inorg. glass and plastic have a transparent conductive film on at least a part of the surface part of said film is dispersed as uniformly as possible to 2-100mum, more preferably 5-75mum spacing therebetween, by which the good non-glare property is imparted to the film. The transparent molding having the non-glare property, high surface hardness and excellent wear resistance and durability is thereby obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a transparent molded article having a surface with excellent non-glare properties (antireflection properties) and abrasion resistance.

The transparent molded product obtained by the present invention has particularly excellent properties in terms of abrasion resistance, and also has glare properties, so it is useful to utilize the characteristics of reducing discomfort and glare caused by reflected light. Therefore, it can be suitably used as a front panel for various displays such as a CRT front panel, a touch panel, a showcase, and a meter cover.

[Conventional technology] Today's information society is progressing at a remarkable rate, and along with this, the number of devices that use displays, such as personal computers, word processors, and other large computer terminals, has increased rapidly, and the performance of displays has improved. , multifunctionality is progressing. In particular, touch panels that allow input according to instructions and graphics on the display surface are becoming more popular. In addition, problems such as eye strain, discomfort, and decreased work efficiency due to the presence of reflected light in front of the display have emerged. In order to eliminate such problems, there is a strong demand for transparent molded products that can provide non-glare properties to the front surface of the display and suppress glare, and various developments are being carried out (Japanese Patent Application Laid-Open No. 1983-1998).
51920, JP-A-59-51923, JP-A-59-
51952, JP-A-59-133268, JP-A-60
-245610, JP-A-61-76328, JP-A-6
1-108520, Special Publication No. 6l-54066).

These methods require a special molding method using an ultraviolet irradiation device and a mold, and the hardness of the molded non-glare surface is low, so they do not have long-term practical durability on the sole. In addition, in the case where the non-glare property was achieved by adding silica fine particles, the adhesion of the film to the inorganic article was insufficient.

[Problems to be Solved by the Invention] The purpose of the present invention is to improve the problems of the prior art as described above, and to provide a film having non-glare properties with significantly improved hardness and improved abrasion resistance. The objective is to provide a durable transparent molded product.

[Means for Solving the Problems] As a result of intensive studies to solve the problems of the prior art, the present inventors have completed the present invention having the following configuration.

``Vehicle and average particle size of 1 to 20 on the surface of a transparent substrate.
A transparent molded article having a surface coating containing antimony pentoxide fine particles of 0 nm and having a coating formed with aggregates having an average diameter of 0.1 μm to 10 μm on at least the outermost surface thereof. Examples of the transparent substrate in the present invention include inorganic glass, molded products such as various plastic articles, sheet films, and the like. Moreover, those having a transparent conductive film on the surface of these transparent substrates can also be used as required.

The transparent conductive film applied on this transparent substrate can be made of various materials known under these names, such as metal thin films such as gold, silver, and palladium, and conductive inorganic oxide thin films. In particular, indium oxide/
Tin oxide thin films (hereinafter abbreviated as ITO) and tin oxide thin films are useful. The thickness of the thin film is preferably 5 nm to 500 nm from the viewpoint of conductivity and transparency.

To form such a thin film, vacuum evaporation, sputtering, other physical vapor phase methods, chemical vapor phase methods using metal halides or organic derivatives, and in some cases thin film forming methods from a liquid phase can be used. Used as appropriate. In forming such a thin film, various chemical and physical surface treatments of the base material and surface modification of the base material can be carried out as necessary. Among these, for substrates on which ITO or tin oxide thin films are provided, immersion treatment in hot water, especially spring water, is preferable in terms of improving adhesion. The same effect is observed whether the treatment is performed before or after film formation.

The film in the present invention contains antimony pentoxide fine particles and a vehicle as essential components, and at least the outermost surface has 0.
It is a coating in which aggregates having an average diameter of 1 μm to 10 μm are formed, and the aggregates scatter external light,
It provides non-glare properties. In particular, it is preferable that the average diameter of the aggregates be 1 to 10 μm in order to significantly express the glare effect, and for the purpose of imparting non-glare properties as well as transparency or high resolution, the average diameter of the aggregates should be 0 μm. It is preferable to control the thickness to .1 to 1 μm. Such fine aggregates form at least irregularities on the surface of the coating, and in order to maintain transparency as high as possible, it is preferable that they exist substantially only in the outermost layer.

Various methods can be considered as means for forming such fine irregularities. For example, S i 0 in the coating composition
2. A method of dispersing inorganic fine particles such as A Q203 and T i 02, a method of dispersing organic polymers, a method of roughening the surface by blowing sand etc. after coating formation, a method of roughening the surface using a grindstone or metal fiber etc. Examples include a method of polishing the surface to make minute scratches to make the surface matte, or a method of making the surface matte by causing a brushing phenomenon in an uncured state after coating with paint. Among these methods, the method of dispersing an organic polymer is preferably used from the viewpoint of cost, ease of processing, pot life of the paint, transparency, reproducibility, etc. More preferably, water-soluble organic polymers are used from the viewpoint of stability and reproducibility of the paint, and among them, celluloses and saponified polyvinyl acetate are most preferred because they can impart non-glare properties without impairing transparency. Furthermore, when using organic polymers, it is also possible to add two or more types of organic polymers having different molecular weights or degrees of saponification. Further, the amount added should be determined depending on the characteristics of the polymer and the desired song glare properties. Each of these methods for forming fine irregularities can produce matte properties depending on the method and purpose, but it is also possible to use two or more methods in combination.

The diameter of the aggregates on the outermost surface of the film as referred to in the present invention can be measured by microscopic observation, but in particular from the perspective of the non-glare property of the aggregates, it can be measured according to JIS BO6.
Most preferably, the diameter obtained by surface roughness measurements as specified in 51 is between 0.1 and 10 μm. Furthermore, for the purpose of controlling non-glare properties, it is effective to control not only the size but also the number of aggregates present per unit area of the aggregates present on the outermost surface of the coating. 2 to 100 μm, more preferably 5 to 100 μm
Good non-glare properties can be achieved by dispersing the particles as uniformly as possible to 75 μm.

The vehicle used in the present invention is not particularly limited as long as it provides transparency, glare properties, and abrasion resistance, and can uniformly disperse antimony pentoxide fine particles to form a transparent film. Thermosetting resins are preferably used from the viewpoint of properties and the like. Further, in order to exhibit non-glare properties, it is preferable to use a water-soluble organic polymer in combination.

Preferred specific examples of these thermosetting resins include epoxy resins and organopolysiloxane compounds.

As the above-mentioned epoxy resin, various epoxy resins known by their names can be used. Particularly effective epoxy resins for the present invention include the following - maximum (n), (I[
Examples include compounds represented by [), (rV), <V>, (Vl), and (VI).

(Here, R is a glycidyl group, 411, Q2, ml, R2
, nl, R2, R3 and R4 are integers from 0 to 15. ) General formula (It>, (I[I), (IV), (V), (V
The epoxy equivalents of the epoxy resins represented by l) and (■) are not particularly limited, but those less than 1000 are preferably used from the viewpoint of compatibility with other components and ease of handling.

As organopolysiloxane compounds, the following -ffi
An organosilicon compound represented by formula (I) and/or a hydrolyzate thereof is used.

R' R2bS l 4-a-b (
I) (In the formula, R1 and R2 are each an alkyl group, an alkenyl group, an aryl group, or a hydrocarbon group having a halogen group, an epoxy group, a glycidoxy group, an amino group, a mercapto group, a methacryloxy group, or a cyano group, and X is a hydrocarbon group) It is a decomposable group, and a and b are 0 or 1.) Specific representative examples include methyl silicate, ethyl silicate, 0-propyl silicate, i-propyl silicate, n-butyl silicate, 5ec-butyl silicate. and tetraalkoxysilanes such as t-butyl silicate, and their hydrolysates, as well as methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltributoxysilane, and ethyltrimethoxysilane. , ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ-talolopropyltrimethoxysilane , γ-chloropropyltriethoxysilane, γ-chloropropyltriacetoxysilane, 3
．． 3.3- Trifluoropropyltrimethoxysilane,
γ-methacryloxypropyltrimethoxysilane, γ
-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, β- Cyanoethyltriethoxysilane, methyltriphenoxysilane, chloromethyltrimethoxysilane, chloromethyltriethoxysilane,
Glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, α-glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycid xyethyltriethoxysilane, α-glycidoxypropyltrimethoxysilane, α-glycidoxypropyltriethoxysilane, β-glycidoxypropyltrimethoxysilane, β-glycidoxypropyltriethoxysilane, γ -glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltriproboxysilane, γ-glycidoxypropyltributoxysilane, γ
- glycidoxyprobyltrimethoxyethoxysilane,
γ-glycidoxypropyltrifenoxysilane, 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)ethyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyl Tripropoxysilane, β-
(3,4-epoxycyclohexyl)ethyltributoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxyethoxysilane, β-(3,4-epoxycyclohexyl)ethyltriphenoxysilane, γ
-(3,4-epoxycyclohexyl)propyltrimethoxysilane, γ-(3,4-epoxycyclohexyl)propyltriethoxysilane, δ-(3,4-epoxycyclohexyl)butyltrimethoxysilane, δ-(
Trialkoxysilanes such as 3,4-epoxycyclohexyl)butyltriethoxysilane, triazyloxysilane, or triphenoxysilanes or their hydrolysates, and dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyljethoxysilane, phenylmethyl Jetoxysilane, γ-lyloropropylmethyldimethoxysilane, γ-chloropropylmethyljethoxysilane, dimethyldiacetoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyljethoxysilane, γ-mercapto Propylmethyldimethoxysilane, γ-mercaptopropylmethyljethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyljethoxysilane, methylvinyldimethoxysilane,
Methylvinyljethoxysilane, glycidoxymethylmethyldimethoxysilane, glycidoxymethylmethyljethoxysilane, α-glycidoxyethylmethyldimethoxysilane, α-glycidoxyethylmethyljethoxysilane, β-glycidoxyethyl Methyldimethoxysilane, β-glycidoxyethylmethyljethoxysilane, α
-Glycidoxypropylmethyldimethoxysilane, α-
Glycidoxypropylmethyljethoxysilane, β-glycidoxypropylmethyldimethoxysilane, β-glycidoxypropylmethyljethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropyl Methyljethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropylmethyldimethoxyethoxysilane, γ-glycidoxypropylmethyldiphenoxy Silane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyljethoxysilane, γ-glycidoxypropylethyldiproboxysilane, γ-glycidoxypropyllvinyldimethoxysilane, γ - Glycidoxypropylphenyldimethoxysilane, γ-glycidoxypropylphenyldimethoxysilane, γ-glycidoxypropylphenyldiethoxysilane, etc. Dialkoxysilane or diacyloxysilane or its hydrolyzate is This is an example.

It is also possible to add one type or two or more types of these organosilicon compounds. Particularly for the purpose of imparting dyeability, it is suitable to use organosilicon compounds containing epoxy groups and glycidoxy groups.

These organosilicon compounds are preferably used after being hydrolyzed in order to lower the curing temperature and further promote curing.

Hydrolysis is produced by adding and stirring pure water or an acidic aqueous solution such as hydrochloric acid, acetic acid, or sulfuric acid. Furthermore, the degree of hydrolysis can be easily controlled by adjusting the amount of pure water or acidic aqueous solution added. During hydrolysis, it is particularly preferable to add pure water or acidic aqueous solution in an amount equal to or more than 3 times the mole of the hydrolyzable group of formula (I) from the viewpoint of accelerating curing.

During hydrolysis, alcohol and other substances are produced, so it is possible to hydrolyze without a solvent, but in order to make the hydrolysis more uniform, hydrolysis is performed after mixing the organosilicon compound and a solvent. It is also possible. Depending on the purpose, alcohol etc. after hydrolysis may be heated and/or
Alternatively, it is possible to remove an appropriate amount under reduced pressure and use it, or it is also possible to add an appropriate solvent afterwards.

Examples of these solvents include alcohols, esters, ethers, ketones, halogenated hydrocarbons, and aromatic hydrocarbons such as toluene and xylene.

Moreover, these solvents can also be used as a mixed solvent of two or more types as required. Furthermore, depending on the purpose, it is possible to accelerate the hydrolysis reaction and further advance reactions such as precondensation by heating above room temperature, or to suppress precondensation, the hydrolysis temperature can be lowered to below room temperature. Needless to say, it is possible to do so.

In the present invention, antimony pentoxide fine particles having an average particle diameter of 1 to 200 nm include water and/or antimony pentoxide.
A specific example is antimony pentoxide sol colloidally dispersed in an organic solvent such as alcohol.
Preferably, particles having a particle size of 5 to 1100 nm are used. If the average particle size exceeds 200 nm, the resulting coating film will have poor transparency and large turbidity.

There is no problem even if various surfactants and amines are added to improve the dispersibility of the fine antimony pentoxide particles. Furthermore, antimony pentoxide fine particles may be coated with other inorganic oxides such as zirconium oxide.

Various curing agents can be used in combination with the coating composition used in forming the film of the present invention for the purpose of accelerating curing and enabling low-temperature curing. As the curing agent, various epoxy resin curing agents or various organosilicon resin curing agents are used.

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, and various salts such as organic carboxylates and carbonates of alkali metals. can be mentioned. It is also possible to use a mixture of two or more of these curing agents. Among these curing agents, the aluminum chelate compounds shown below are particularly useful for the purpose of the present invention from the viewpoints of stability of the coating material, coloration of the coating film after coating, and the like.

The aluminum chelate compound referred to herein is, for example, an aluminum chelate compound represented by the general formula AαXn Y3-n.

However, in the formula, or 0L (L is a lower alkyl group), Y is the general formula MI C
OCHpCOM" (Ml, M2 are both lower alkyl groups) and at least one ligand derived from a compound represented by the general formula % (lower alkyl group) Yes, π is 0.1 or 2
It is.

One maximum AαXn ”3 particularly useful as a curing agent in the present invention
As the aluminum chelate compound represented by -n,
Various compounds can be used, but from the viewpoint of solubility in the composition, stability, and effect as a curing catalyst, aluminum acetylacetonate, aluminum and suetyl acetoacetate monoacetylacetonate, and aluminum Di-n-butoxide-monoethyl acetoacetate, aluminum-di-1SO-pro ・
Examples include poxide monomethyl acetoacetate. It is also possible to use a mixture of two or more of these.

Coating means for coating the transparent substrate of the present invention include brush coating, dip coating, roll coating, spray coating,
Commonly used coating methods such as spin coating and flow coating can be easily used.

The thickness of the coating in the present invention is not particularly limited. However, from the viewpoint of maintaining adhesive strength and hardness, 06
It is preferably used between 5 μm and 20 μm. Particularly preferably, the thickness is 0.7 μm to 15 μm. In addition, when applying the coating composition, it is used after being diluted with various solvents for workability, film thickness adjustment, etc. Examples of diluting solvents include water, alcohol, ester, ether, halogenated hydrocarbon, dimethylformamide, dimethyl Sulfoxide etc. can be used in various ways depending on the purpose.
A mixed solvent can also be used if necessary. However, from the viewpoint of dispersibility of antimony pentoxide, water, alcohol, dimethylformamide, ethylene glycol, diethylene glycol, triethylene glycol, benzyl alcohol, phenethyl alcohol, phenyl cellosolve, and the like are preferably used.

To form a film from these compositions, a coating composition containing these compositions is applied and then dried and cured by heating.

Although the curing temperature varies depending on the compound selected and the working conditions, a temperature of 60°C to 300°C, preferably 80°C to 200°C is used. Curing is insufficient at temperatures lower than this,
At high temperatures, problems such as cracks and film decomposition occur.

The transparent molded product obtained by the present invention has non-glare properties due to the aggregates on the outermost surface, and the coating itself maintains transparency, has a high hardness surface, has excellent wear resistance, and has excellent abrasion resistance. It can be preferably used for various display front panels such as front panels, touch panels, showcases, and meter covers.

EXAMPLES In order to clarify the characteristics of the present invention, Examples are given below, but the present invention is not limited to these Examples.

[Example 1 (1) Preparation of coating composition (a) Adjustment of γ-glycidoxyprobyltrimethoxysilane hydrolyzate. Charge 100.7f of methoxysilane and adjust the liquid temperature to 10℃
0.0 while stirring with a magnetic cooler.
23.0 g of 1N aqueous hydrochloric acid solution was gradually added dropwise. After the dropwise addition is completed, stop cooling to obtain a hydrolyzate of γ-glycidoxypropyltrimethoxysilane.

(b) Preparation of paint Add bisphenol A type epoxy resin (manufactured by Shell Chemical Co., Ltd., trade name: Ebico) 827)7 to the silane hydrolyzate.
1.3t, N,N-dimethylformamide 221g, benzyl alcohol 99.9g, methyl alcohol 171g
．． 2g of silicone surfactant and 1.5g of silicone surfactant were added and mixed, and further 297.2t of colloidal antimony pentoxide sol (manufactured by Kaguchi Kagaku Co., Ltd., trade name Antimony Sol A-2550) was added.
, aluminum acetylacetonate) and stirred thoroughly, polyvinyl alcohol (manufactured by Nippon Gosei Kagaku Co., Ltd., trade name Gohsenol GL-〇5 saponification degree 8) was added.
33 g of a 7.5 mO+%>15 vt% aqueous solution was added and stirred to obtain a coating composition.

(2) Preparation of transparent molded product with song glare properties An inorganic glass plate (70 x 80 x 3 mm
) was dip-coated with the coating composition prepared in (1) at a pulling rate of 20 cIl/min, and then
Preliminary curing was performed at 0°C for 12 minutes, and after heating in a hot air dryer at 140°C for 2 hours, immersion treatment was performed in spring water at 120°C for 1 hour. Thereafter, it was further dried for 2 hours in a hot air dryer at 140°C to obtain a transparent molded product with non-glare properties.

Further, the film thickness was 2.8 μm. The average diameter of the aggregates at the outermost surface of the coating was 0.5 μm as measured according to JIS BO651.

(3) Evaluation When the transparent molded product obtained in (2) above was attached to the front of a CRT, characters and figures on the CRT screen could be clearly seen. In addition, when we reflected indoor fluorescent lights (37 watts) off the front of the transparent molded product, the reflection was much lower than that of the base material before coating, and we did not feel any glare. The total light transmittance at this time was 79%, and the surface gloss at a 60° angle measured by a glass meter (manufactured by Murakami Shikizai Research Institute) was 95%. In addition, use a steel knife to insert 100 goblets reaching the 1m square substrate on the coating surface, firmly adhere cellophane adhesive tape (trade name "Cello Tape" Nichiban product), and quickly move it in a 90 degree direction. When it was peeled off and examined for the presence or absence of paint film peeling, no paint film peeling was observed, indicating that it had good adhesion. A pencil hardness test (JIS K5400) was conducted as a surface hardness test and 8H was obtained. Further, even though the coating film was strongly rubbed with steel wool (#0OOO), there was hardly any scratches and the surface had good surface hardness.

Example 2 (1) Preparation of coating composition The coating composition of Example 1 without adding a 15 wt % aqueous solution of polyvinyl alcohol was used as a coating composition.

(2) Example 1 of manufacturing a transparent molded product with non-glare properties
After dip coating, leave it indoors (23℃, 90℃).
%RH) for 5 minutes and then precuring at 80° C. for 12 minutes, the same procedure as in Example 1 was carried out to obtain a transparent molded article having good non-glare properties, especially in the center.

The main film thickness was 2.5 μm. The average diameter of the aggregates at the outermost surface of the coating is JIS BO65 at the center.
As a result of measurement according to No. 1, it was 0.4 μm.

(3) Evaluation Example I It had good transparency and glare like Example 1, and had the same performance as Example 1 in terms of adhesiveness and surface hardness. At this time, the total light transmittance was 85% and the gloss was 99%. However, some unevenness was observed in the matte properties.

[Effects of the Invention] The transparent molded article with excellent surface properties obtained by the present invention has the following effects.

(1) A transparent molded product with non-glare properties, high surface hardness, and excellent wear resistance and durability can be obtained.

(2) The coating has good stability, and transparent molded products with good productivity and reproducibility can be obtained.

(3) Even when a film is formed on a transparent conductive film, it has excellent adhesiveness, durability, and surface hardness.

(4) It has a large capacitance and is suitable for capacitive finger touch input devices.

Claims (10)

[Claims] (1) Vehicle and average particle diameter of 1 to 2 on the surface of a transparent substrate
1. A transparent molded article having a surface coating containing antimony pentoxide fine particles of 0.00 nm and having a coating formed with aggregates having an average diameter of 0.1 μm to 10 μm on at least the outermost surface thereof. (2) Claim No. 1, characterized in that the transparent base material is a base material selected from inorganic glass and plastic.
1) A transparent molded product having a surface coating as described in item 1). (3) A transparent molded article having a surface coating according to claim (2), wherein the inorganic glass or plastic has a transparent conductive film on at least a part of its surface. (4) Claim (3) characterized in that the transparent conductive film is made of tin oxide and/or indium oxide.
A transparent molded product having a surface coating as described in 2. (5) Claim (1) characterized in that the vehicle contains at least an organosilicon compound represented by the following general formula (I) and/or a hydrolyzate thereof, an epoxy resin, and a water-soluble organic polymer. Transparent molded products. R^1_aR^2_bSi_4_-_a_-_b( I
) (wherein R^1 and R^2 are each an alkyl group, an alkenyl group, an aryl group, or a hydrocarbon group having a halogen group, an epoxy group, a glycidoxy group, an amino group, a mercapto group, a methacryloxy group, or a cyano group, X is a hydrolyzable group, a and b are 0 or 1) (6) A patent claim characterized in that the epoxy resin is one or more selected from the group consisting of bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol F epoxy resin, and hydrogenated bisphenol F epoxy resin. A transparent molded article having a surface coating according to item (5). (7) A transparent molded article having a surface coating according to claim (5) or (6), wherein the epoxy resin has an epoxy equivalent of less than 1,000. (8) A transparent molded article having a surface coating according to claim (5), wherein the water-soluble organic polymer is a hydroxyl group-containing organic polymer. (9) A transparent molded article having a surface coating according to claim (8), wherein the hydroxyl group-containing organic polymer is one or more selected from celluloses and saponified polyvinyl acetate. (10) A transparent molded article having a surface coating according to claim (1), wherein the coating has a thickness of 0.5 μm to 20 μm.