JPS59116601A - Light transmitting body made of antidazzling synthetic resin - Google Patents

Abstract

PURPOSE:To obtain a light transmitting body made of antidazzling synthetic resin by forming a specified uneven structure and a specified antireflection structure on the surface of a synthetic resin plate so as to make an image on the inside of the resin plate easy to see. CONSTITUTION:The surface of a synthetic resin plate of polymethyl methacrylate, a diethylene glycol bisallyl carbonate polymer or the like is provided with 0.1-2mum Rz average surface roughness at ten spots (JIS-B-0601-1970) by coating paint having a property of forming an uneven surface or by other method. A thin interference film is then formed by vacuum deposition or other method to regulate the surface light reflectance at 500-600nm wavelengths to <=2%. Thus, the titled light transmitting body is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-glare light transmitting body, and more specifically to display cases, cover glasses for frame frames, cover glasses for clocks and instrument scales, CRTs, and TJEDs.

Suitable for use in light display surfaces such as LCDs and plasma displays, or their front plate rings, where reflection of light rays must be prevented.It prevents glare, improves visibility, is lightweight, has excellent scratch resistance, and is colored 1. This invention relates to a light transmitting body made of a synthetic resin plate with a high degree of freedom. Anti-glare refers to reducing the brightness and clarity of reflected images of external light sources.

It is a common experience that specular reflections from shiny surfaces, such as smooth glass surfaces or plastic surfaces, can obscure images behind those surfaces and cause discomfort to viewers.

When viewing television or CRT images, it is a daily experience that the image on the screen becomes difficult to see due to the reflected image of the light source from the window or electric light, and a similar phenomenon occurs due to the force...
It can also be seen when viewing a painting through a glass or viewing the scale of a meter through a glass.

To prevent glare caused by these specular reflections.

Several methods have been proposed so far, and are basically divided into the following three methods.

(1) A method of reducing the clarity of a single reflected image by providing minute irregularities on the surface of a light transmitting material and utilizing light scattering phenomena.

(2) A method of reducing the brightness of a single reflected image by providing a thin film of metal oxide, fluoride, etc. on the surface of a light transmitting body and utilizing light interference phenomena.

(3) A method of reducing the brightness of the reflected image by incorporating dyes or pigments into the light-transmitting material and utilizing light absorption phenomena.

The first method is an extremely effective method for reducing the clarity of the reflected image, but it has the drawback that the resolution of the transmitted image decreases as the effect is improved.

Although the second method is an extremely effective method for reducing the brightness of one reflected image, it is difficult to achieve a reflectance of O in the entire range of visible light. Therefore, in reality, there is a reflected image, and unless the reflected image is clear, there is a disadvantage that it leaves a feeling of discomfort. The third method is particularly effective when used as a front panel of a one-light-emitting display device, but it has the drawback that there is a limit to the reduction in transmittance.

In addition to the six methods mentioned above, conventional techniques include:

Examples of combinations of the first method and the sixth method and combinations of the second method and the third method are known. (Unexamined Japanese Patent Publication No. 55-4
(No. 078, Japanese Unexamined Patent Publication No. 1983-14749) The ideal method for preventing glare is to use the second method to set the reflectance in the entire visible range to O, but realistically, For some reason, the specular reflection image remains, so the annoyance cannot be resolved.

The inventors of the present invention have investigated a specific method for solving the troublesomeness of specularly reflected images on surfaces that are anti-reflective. By forming an anti-reflection structure on the surface due to optical interference, it is possible to reduce the clarity of a single reflected image even if the reflectance in the entire visible region is not O, making it suitable for practical use. It has been found that a light transmitting material with greatly improved visibility can be obtained.

That is, in the present invention, at least one surface has a surface roughness of 01 to 2 μR2 and a roughness of 500 to 600 nm.
The gist of this invention is an anti-glare synthetic resin light transmitting body characterized by being made of a synthetic resin plate having a surface light reflectance of 2 inches or less.

In the present invention, the surface roughness of at least one side, the front side where light enters, is 01 to 2 on a surface ten point average roughness scale.
It needs to be μRz. What is surface 10-point average roughness?JIB
This is a roughness display method described in B-0601-1970.

If the surface roughness is less than 0.1μRZ, the blurring effect of the specularly reflected image will not be sufficient, and if it is more than 2μRZ, the resolution of transmitted light will decrease or it will reach a level that is not desirable for practical purposes. This results in some disadvantages. In addition, it is preferable that the surface light reflectance has a uniformly low value in the entire wavelength range of visible light, but it is preferable that the surface light reflectance has a uniformly low value in the entire wavelength range of visible light.
Of particular importance is the low surface light reflectance in the 00 nm range.

Therefore, the surface light reflectance of glass or plastic, which is a conventional base material for forming a light transmitting body, is about 4 nm, but in order to obtain the effective antireflection effect of the present invention, the surface light reflectance is 500 to 600 nm. It is necessary to keep the ratio below 2q6.

When this surface light reflectance is combined with the uneven structure formed on the surface of the light transmitting body, the surface light reflectance decreases to a fraction of a second. It is possible to obtain a light-transmitting body that is easier to see than ever before.

It is important to use a synthetic resin as the material for the base material that forms the light transmitting body, as it is lightweight, has excellent moldability, is resistant to mechanical shock, and has excellent flexibility in coloring. be. The inherent disadvantage of synthetic resins is that they have low surface hardness and are easily scratched.

Surface hardening treatment technology that has already been developed (generally 7
Coating with silicone, urethane, melamine, and acrylic surface hardening paints.

It can be cut by surface hardening treatment by vacuum processing of hard inorganic materials such as inorganic oxides such as 5102. Examples of synthetic resins used as base materials include polymethyltutaacrylate and copolymers thereof, acrylonitrile-styrene copolymers, and ABS resins.

Thermoplastic resins such as polycarbonate, cellulose acetate, cellulose acetate butyrate, cellulose acetate-1-propionate, polyvinyl chloride, polyethylene terephthalate, epoxy resins, urethane resins, unsaturated polyester resins.

A wide range of synthetic resins with excellent transparency can be used, such as thermosetting resins such as diethylene glycol-rubysallyl carbonate polymers, but polymethyl methacrylate is particularly useful.
1., diethylene glycol bisallyl carbonate, or copolymers thereof are preferred. These synthetic resin plates are not particularly limited as long as they are plate-shaped, such as a flat plate or a single curved plate.

It may also be a thin sort, a film, or an extremely thick molded product, but a plate-like shape is preferred.

Curved ones are good. It is also possible to use an r1 polarized notebook board depending on the purpose.

Two different methods can be used to obtain a light transmitting body having a surface structure according to the present invention. Generally, the surface light reflectance of a synthetic resin base material is around 4 coefficients, so
The characteristics of the present invention cannot be obtained by simply forming irregularities on the surface of the profiteer itself because the surface light reflectance does not change.

Therefore, it is necessary to first form irregularities on the surface of the base material by some method and then apply some kind of anti-reflection treatment.

As a method for forming the unevenness required by the present invention on the surface of a light transmitting body made of a synthetic resin base material, several methods including methods that have already been put into practical use can be applied. Examples include the monomer casting method using a template glass or metal template with the desired unevenness formed on the surface, the thermoforming method using a similar template, and the synthetic resin base material using a paint that has the ability to form unevenness. Typical methods include coating the surface with 9-surface hardening technology, which is effective for the ribs because the surface of synthetic resin base materials is soft and easily damaged by crows, etc. Specifically, coating with a hard paint such as a silicone-based paint that has an unevenness forming property, or applying a hard coating such as 8102 to a synthetic resin base material with an uneven surface manufactured by a mold transfer method, by vacuum evaporation, sputtering, or ion bubbling. 2) The surface is hard and does not easily scratch by forming it by a method such as rating, or by coating a base material with unevenness on the 1st surface with a hard paint under conditions that do not completely fill in the unevenness. It is possible to prepare a light transmitting base material having surface irregularities that satisfy the conditions of the present invention as well as having good performance.

As the antireflection processing method to be performed next, various methods including methods that have been put into practical use can be applied. For example, vacuum evaporation.

A method of forming an inorganic thin film by ion blating, snobbing, etc., a method of forming an interference thin film by coating with paints with different refractive indexes at normal pressure, and a method of forming a low refractive index layer on the surface by post-treatment such as plasma treatment. 7. Pre-coat with a coating that can form One example is a method of imparting a foul prevention effect through post-processing.

The roughness of the final surface of the surface to which the surface has been made uneven and has an antireflection effect ranges from 0.1μRZ to 2μ on a 10-point average roughness.
It is essential that the surface reflectance is in the Rz range and in the wavelength range of 500 to 600 nm is a factor of 2 or less.

The light transmitting body according to the present invention can be used as a CRT or an LED.

When used as an observation surface of an optical display device such as a plasma display (LCI) or a plasma display, a method of combining a light attenuation effect due to characteristic light absorption, which has been proposed in the past, is effective. Furthermore, a method of combining a transparent conductive film with one synthetic resin base material is also effective in imparting an electromagnetic wave blocking effect. Furthermore, when the product of the present invention is used as a front plate of an optical display device, by combining it with a circularly polarizing plate, it is possible to prevent reflections from the front glass surface of the display and further improve the effect as a front plate. .

Examples embodying the present invention are listed below.

These are not intended to limit the method of implementing the present invention.

Example 1 Flat polymethyl methacrylate with a thickness of about 15I]]]II] [light transmittance at 660 nm with a gear strike plate of about 4]
I got the red colored one from Section 5 from Nanchu. Next, a highly hardened surface paint containing a hydrolyzate of methyltrimethoxine lantriate/nlan as a main component and a gel as a surface unevenness forming phase (published in 1982-12107) was developed.
(described in the publication), coated on the previous cast plate and cured at 80℃ for 2 hours,
P' has a matte appearance with excellent surface hardness on both sides.
An MMA resin plate was obtained. Next, on one side of this resin plate,
Vacuum deposition equipment (Shinku Kikai Kogyo “%BMc-800T type)”
The first layer is aluminum oxide, the second layer is
The layers were formed with a two-layer anti-reflective coating of silicon dioxide. The optical thickness of each layer was 550/4 nm.

The surface 10-point average roughness of the product of the present invention thus obtained was 0.
．． 2pRz (TALY manufactured by TAYLOR-HOBSON
19URF4) and 500 to 600 nm
The surface light reflectance in the wavelength range was 16-17% (according to Hitachi spectrophotometer model 7660).

A PMMA resin plate (Comparative Example 1) having a matte appearance before applying anti-reflection treatment to the product of the present invention.

Results of a comparison of the practical performance as an LED front plate of a resin plate (Comparative Example 2) manufactured in the same manner as the present invention except that it was coated with a paint with the silica sol removed from the above paint (to obtain a mirror surface). .

It was as shown in the table below.

Example 2 A commercially available single-sided matted 4p MM A plate (Kyowa Gas Kagaku ■°°Paraglass F584K'', thickness of about 2 plates, ten-point average roughness of about 5μR1 was obtained, and the inner surface radius of curvature was about 630II. ]fI]. After coating this plate with a primer prepared by dissolving PMMA pellets in a solvent, the γ-grid prepared by the method described in Japanese Patent Publication No. 57-2735 was A hardened surface coated with a surface hardening paint mainly composed of cynopropyl methyljethoxysilane, a hydrolyzate of hydrochloropropyltrimethoxy/silane, and metatol silica sol, "Epicoat" 827, which has an uneven shape on one side. A plate was prepared.Then, this cured plate was heated to an oxygen flow rate of 50% using a plasma reactor (Model PC-101A manufactured by Yamato Pharmaceutical Co., Ltd.).
A low refractive index layer was formed on the surface by processing at cc/min, 50 W, for 4 minutes. Furthermore, an extremely thin film of a hydrolyzate of γ-glycidoxypropyltrimethoxy 7-lane was formed as a surface protective film, and curing was performed to obtain a light transmitting material.

The surface roughness of the obtained light transmitting body is approximately 1.0 μRz, and the surface reflectance in the range of 500 to 6 CI Onm is 1.
．． They were in charge of 0-16.

The product of the present invention was compared with a conventionally known CRT front panel with an uneven surface without antireflection processing and a CRT front panel with multilayer antireflection processing on the front glass surface of a personal computer green monitor television front panel. As a result of examining the practical performance as an inventive product, it was found that the visibility of the transmitted image of the product using the present invention was extremely poor.

Example 6 A single-sided matte surface hardened acrylic resin plate prepared in the same manner as in Example 2 was prepared, and then a four-layer antireflection film was formed on the matte surface using a vacuum evaporation device (from the base material side). The first layer is aluminum oxide.

The second layer is zirconium oxide, the sixth layer is tantalum oxide, the fourth layer is silicon dioxide, and the optical thickness of each layer is 550 nm/
4). The ten-point average roughness of the surface of the light transmitting body according to this example thus obtained is about 1.2 p Rz, and the surface light reflectance at 500-600 nm is about 0.6
It was q6. When this transparent material was used as the front panel of a green monitor television for personal computers, its practical performance was significantly superior to that of conventional front panels.

Claims (1)

[Claims] Made of a synthetic resin plate with at least one surface having a ten-point average roughness of 01 to 2μRz and a surface light reflectance of 2% or less at 5-00 to 60 nm.