JPH02256032A - Glass or plastic product having antireflection coating, its production and coating composition - Google Patents

Abstract

PURPOSE:To improve the antireflection effect of the film by using the composition contg. specified amts. of an org. resin binder and the MgF2 grains having below the specified average diameter. CONSTITUTION:A composition consisting of 5-50wt.% org. resin binder and 95-50wt.% MgF2 grains having <=500Angstrom average diameter is mixed with an org. solvent, and the obtained soln. is applied on a glass or plastic product. Since the antireflection coating has to compensate the reflected light of the surface and the reflected light of the lower surface by making both light an antiphase to each other, the film thickness is preferably controlled to 1/4 of the wavelength of visible light, namely to about 0.1mum (about 1,000Angstrom ). When the average diameter of the MgF2 grains exceeds 500Angstrom , the film thickness becomes larger than 0.1mum at the overlapped part of the grains, hence a protrusion of the grain is formed on the film surface, the smoothness is deteriorated, hazing is caused, and transparency is deteriorated. By this method, the antireflection effect of the coating on the surface is improved, the surface is smoothed, and hazing is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a glass or plastic product having an antireflection film, a method for producing the same, and an antireflection coating composition.

The anti-reflection coating composition of the present invention is applied to television cathode ray tubes, picture front glasses, showcase glass plates, eyeglass lenses, etc., and the resulting coating film prevents the reflection of visible light and, by extension, the appearance of virtual images due to reflection. It is effective in preventing.

[Prior Art and Problems to be Solved by the Invention] Surface reflection of transparent inorganic glass or plastic articles poses various problems. For example, fluorescent lights reflected on a TV's cathode ray tube and the scenery outside the window make it difficult to see the TV image. The front glass of a picture, the glass plate of a showcase, and the plastic plate make the picture or product unclear due to the reflected light from the surface.

Further, reflection on the surface of the eyeglass lens reduces the amount of light transmitted through the eyeglass lens.

Conventionally, MgF 211! has been used as an anti-reflection coating. A method is known in which a titanium-containing organometallic compound and a silicon-containing organic compound are hydrolyzed to form a multilayer coating consisting of a TiO2 film and 5iO2Wi.

However, in the case of the MgF2 vapor-deposited film, large articles cannot be coated due to restrictions on vapor deposition equipment. Mg
F2 film has the disadvantages of low adhesion, low hardness, and low scratch resistance, so it must be baked on glass products, and cannot be baked on plastic products, so it has not been a practical coating film. . In addition, obtaining a uniform coating thickness through vapor deposition requires extremely sophisticated technology, and when the dimensions and shape of the object to be vaporized change, the vapor deposition conditions and equipment must be adjusted each time to find the best settings. The problem is that it has to be done. Furthermore, a film formed by hydrolyzing an organometallic compound is inferior in antireflection effect compared to MgF2.

[Problem to be solved by the invention]

An object of the present invention is to provide an antireflection composition which has an excellent antireflection effect and can be formed into a film industrially advantageously.

Another object of the present invention is to provide a method of forming antireflective coatings on glass and plastic products using such compositions.

[Means to solve the problem]

In the present invention, the solid content is 5 to 50% by weight of the organic resin binder.
and 95 to 50 HgF2 particles with an average particle size of 500 Å or less.
% by weight.

The present invention further provides 5 to 50% by weight of an organic resin binder.
and MgF2 particles with an average particle size of 500 Å or less 95-5
0% by weight, is mixed with an organic solvent that dissolves the resin, and the resulting liquid is applied to the glass or plastic product. Provide manufacturing method.

The antireflective coating composition of the present invention has an average particle size of 500 Å or less, preferably 400 to 10 M [? Contains F2 particles. Anti-reflection coatings must make the light reflected from the surface of the film and the light reflected from the bottom surface opposite in phase to cancel them out.
The film thickness is preferably 1/4 of the wavelength of visible light, that is, the film thickness is preferably about 0.1 μm (about 1000 μm). The average particle size of MgF2 particles in the film is 500
If the thickness exceeds 0.1μ, the film thickness will be larger than 0.1μ in the overlapping part of the cocoon, and the film will have protrusions on the film surface, resulting in poor smoothness and haze, which will impair the transparency of the product. There is a problem. In order to make the coating surface smooth, the particle size is preferably 115 or less of the film thickness, so Mg
A particularly preferred average particle size of the F2 particles is 200 to 50 particles.

The above-mentioned fine MgF2 particles used in the present invention can be obtained, for example, by plasma evaporation and precipitation in air.

In order for the target transparent article to be clearly visible for a long time, the film strength must be high. If the amount of the organic resin binder exceeds 50% by weight (the amount of MgFz is less than 50% by weight), the strength will be considerably low, so the amount of the organic resin binder should be 50% by weight or less. When the amount of MgF2 in the composition is 50% by weight or more, the coating film strength is high.
As the amount of MgF2 increases, the strength becomes even greater.
Weight strength of 80-850-85 reaches the highest level. Furthermore, as the weight of MgF increases, the strength decreases, and 9
Above 5% by weight, the film strength falls below an acceptable level. Therefore, the amounts of the organic resin binder and MgF2 in the antireflective coating composition of the present invention are based on the total weight of both:
The former should be 5 to 50% by weight, and the latter should be 95 to 50% by weight.

The organic resin binder is not particularly limited as long as it is a transparent resin, and may be appropriately selected from among polyester resins, acrylic resins, vinyl resins, polycarbonate resins, polyolefin resins, etc., depending on the type of the article to be coated. Bye.

A coating composition is prepared by adding an organic solvent capable of dissolving the binder to an organic resin binder and MgF2, but the type and amount of the solvent are not particularly limited.
The organic resin binder is appropriately selected in consideration of its solubility, boiling point and viscosity suitable for the coating method. Generally, the amount of solvent will be between 50 and 98% by weight based on the total weight of the composition including the solvent.
is within the range of

The antireflective coating composition can be prepared in the same manner as many resin coatings, and there are no particular restrictions on how the coating composition can be applied to the target article as long as it can form a thin film. Normal application methods can be used without any problems. In particular, dipping, spin cord, and gravure printing are suitable because they yield a coating film that is thin, has a smooth surface, and has low haze.

If necessary, the coating film is cured by a conventional method under appropriate conditions depending on the type of organic resin binder used.

Glass products and plastic products on which the antireflection film of the present invention is formed include, for example, window glasses and windshields of automobiles, ships, aircraft, etc.; cathode ray tubes and front glasses or plastic plates of CRTs, televisions, etc.; liquid crystal display devices, Glass plates and plastic plates for instruments; glass plates and plastic plates for display windows, museums and art galleries; glass plates and plastic plates for watches; spectacle lenses and camera lenses; and glass plates and plastic plates for solar cells.

〔Effect of the invention〕

The surface coating film formed from the antireflection coating composition of the present invention has an excellent antireflection effect, has a smooth surface and low haze, and can be formed with industrial advantage.

〔Example〕

The present invention will be specifically described below with reference to Examples.

In each example, surface reflectance was measured with a spectrophotometer. In addition, the surface hardness (pencil hardness) is JIS K-5400.
and 5401 compliant.

Implementation 10 = Polyester resin (Watersol S- manufactured by Dainippon Ink)
123) 0.3 parts by weight, 27 parts by weight of MgF with an average particle size of 150 (mostly distributed between 50 and 250) and a mixed solvent of methyl ethyl ketone/toluene (mixed weight ratio of 50)
: 50) Mix and stir 40 parts by weight in a ball mill,
A coating composition was obtained. This coating composition was applied to a methacrylic resin transparent plate by dipping method, and the dry film thickness was 0.1 μm.
A film of porridge was formed.

The surface reflectance was 8% before application, but it was approximately 3% after application.
It was reduced to

Hiba salmon λ Average particle size: 150 MgF'2 (Most are 50-25
A coating composition was prepared by stirring 3 parts by weight of water-soluble acrylic resin (Watersol 5744, manufactured by Dainippon Ink), and 100 parts by weight of isopropyl alcohol in a ball mill for 1 day and night. .

The above coating composition was applied to an acrylic resin plate by a dipping method and dried at 120°C for 10 minutes to a thickness of 0.1μ.
A film of m was made.

The surface hardness was 5H5 and the surface reflectance was 3.2%.

The surface hardness of the uncoated acrylic plate was HB, and the surface reflectance was 8%.

Large 11 Average particle size 150 people HgF2 (mostly distributed between 50 and 250 people) 4 g, melamine resin (Dainippon Ink, Watersol S-5-683-L 1 g, acrylic resin (
Dainippon Ink, Watersol S-732) 1 g
A coating composition was prepared by stirring 200 g of isopropyl alcohol in a ball mill for 10 hours.

The above coating composition was spin-coded on an acrylic resin plate, and 1
It was dried at 30° C. for 15 minutes to form a film with a thickness of 0.1 μm.

The surface hardness was 6H1 and the surface reflectance was 2.8%.

The surface hardness of the uncoated acrylic resin plate was HB, and the surface reflectance was 8%.

The MgF2 used in Example 1 was mixed with MgF2 having an average particle size of 700.
A coating composition was prepared in the same manner as in Example 1 except that gF 2 was used, and this was applied by dipping onto an acrylic resin plate.
It was dried at 20° C. for 10 minutes to form a film with a thickness of 0.1 μm.

Although the surface hardness was 5H1 and the surface reflectance was 7%, the film became cloudy.

100 parts by weight of Acdic resin manufactured by Daisake Dai Nippon Ink Co., Ltd., 360 parts by weight of toluene, and particle size 50-1 manufactured by Sumitomo Cement Company.
40 parts by weight of MgF2 ultrafine particles were added, mixed for 60 minutes in a sand mill, and further dispersed for 20 minutes using ultrasonic waves with an output of 1200 W to prepare an antireflection coating.

This paint was applied to the surface of an automobile dash board (transparent polycarbonate cover, one side reflectance 4%) using a spin cord, heated at 120°C for 60 minutes, and a film thickness of 120 nm was obtained.
A coating film of m was obtained. The single-sided reflectance was 2%, reducing the amount of light reflected from the dash board and making instruments easier to see.

Dog 1 salmon i 100 parts by weight of Byron resin manufactured by Toyobo Co., Ltd., 50 parts by weight of methyl ethyl ketone, 50 parts by weight of toluene, 10 parts by weight of MgF2 powder with a particle size of 50 to 100 manufactured by Sumitomo Cement Co., Ltd., powder amount 0 parts by weight, in a sand mill for 60 minutes The mixture was mixed and further dispersed using an ultrasonic dispersion machine at 1200 W for 25 minutes to prepare an antireflection coating.

This paint is polycarbonate (CR39, reflectance 8%)
A plate was dip coated and dried by heating at 120° C. for 60 minutes to form a film. The film thickness was 1105 nm, and the reflectance was 4%, indicating an improvement in reflectance.

Claims (1)

[Claims] 1. Solid content: 5 to 50% by weight of organic resin binder and 95 to 50% by weight of MgF_2 particles with an average particle size of 500 Å or less
An anti-reflective paint composition comprising: 2. The antireflective coating composition according to claim 1, wherein the average particle size of MgF_2 is 400 to 10 Å. 3. The antireflective coating composition according to claim 1, wherein the average particle size of MgF_2 is 200 to 50 Å. 4. Solid content of organic resin binder 15-20
Antireflective coating composition according to any one of claims 1 to 3, comprising 80-85% by weight of MgF_2 particles. 5. Organic resin binder 5-50% by weight and average particle size 5.
An antireflection coating is produced by mixing a composition consisting of 95 to 50% by weight of MgF_2 particles with a size of 00 Å or less with an organic solvent that dissolves the resin, and applying the resulting liquid to glass or plastic products. A manufacturing method for glass or plastic products. 6. Mg with an average particle size of MgF_2 of 400 to 10 Å
The method according to claim 5, wherein F_2 is used. 7. Mg with an average particle size of MgF_2 of 200 to 50 Å
The method according to claim 5, wherein F_2 is used. 8. The composition contains 15 to 20% by weight of an organic resin binder and M
The method according to any one of claims 5 to 7, comprising 80 to 85% by weight of gF_2 particles. 9. A glass or plastic product having an antireflection film obtained by the manufacturing method according to any one of claims 5 to 8.