JPS63172101A - Crt filter - Google Patents

Abstract

PURPOSE:To improve the resolution, glare retarding effect, scratch resistance, and flame resistance of a CRT filter comprising polyvinyl chloride by forming a hard coating layer contg. silica having specified particle size on a surface opposite to the surface of the CRT. CONSTITUTION:A hard coating layer contg. 3-30wt.% silica having 1-50mum mean particle size is formed on the surface opposite to the surface of a CRT in a CRT filter comprising polyvinyl chloride and having a shape capable of contacting tightly to the CRT surface. The polyvinyl chloride to be used is one having flame resistance without using any particular flame retardant and having transparency since the resin itself has self-extinguishing characteristic. The hard-coating agent to be used is thermosetting hard coating agent such as silicone resin type, epoxy resin type, phenol resin type, or ultraviolet ray cured hard coating agent such as acrylic resin type, urethane resin type. Among said hard coating agents, ultraviolet ray cured type hard coating agent is most suitable for polyvinyl chloride. By this constitution, a CRT filter having scratch resistance, glare retarding effect, flame resistance at the same time is provided, which prevents reflection of illuminating light, etc. on the surface of the CRT filter.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a CRT filter.

[Conventional technology]

O of word processing sensor, personal computer, etc.
CRT display devices such as A-devices and analytical devices have become so widespread that they have become indispensable in offices, homes, and factories. Along with this, the number of operators who come into close contact with CRTs for long periods of time is increasing, and in developed countries, occupational diseases of operators, so-called OA disease, are becoming a social problem. One of the reasons for this negative effect is that indoor light and sunlight reflect on the screen, causing eye fatigue.

Furthermore, in CRTs for consumer televisions, there is a problem in that light from lighting and the like is reflected on the screen. In order to prevent such problems, the surface of the CRT is roughened and treated with anti-glare treatment, or a flat CRT filter with anti-glare properties is attached.

As a method of imparting anti-glare properties to a CRT filter, C
A method for roughening the surface of an RT filter (for example, JP-A-50-96128, JP-A-55-12107, JP-A-56-32653, JP-A-60-60)
291, etc.), a method of directly using a net with a specific opening as a CRT filter (Japanese Unexamined Patent Publication No. 57-1983),
126054, Japanese Patent Application Laid-Open No. 61-46903)
, a method of coating the surface of a CRT filter with many layers of ceramics or metal films by sputtering or vapor deposition has been used.

On the other hand, if the surface of a CRT made of glass is made rough or if glass is used as a material for a CRT filter, there is a problem that the CRT filter is easily broken due to the lack of impact resistance of the glass. Therefore,
Plastics are suitable as materials for CRT filters. However, plastics have poor surface hardness and are easily scratched. Therefore, CR made of plastics
In addition to providing anti-glare properties, the T filter needed to be coated with a hard coat on the side opposite to the CRT (hereinafter referred to as the viewing side).

[Problem that the invention seeks to solve]

However, it has not always been easy to apply a hard coat after imparting anti-glare properties using the method described above. For example, when a hard coat layer is further provided after roughening the surface of a CRT filter, there is a problem in that the anti-glare properties of the CRT filter are significantly reduced because the hard coat agent fills in the irregularities on the surface of the CRT filter. CR online directly
When used as a T-filter, applying a hard coat over the net will significantly reduce the resolution and strength of the CRT filter, making it unusable as a CRT filter. CR
When applying a hard coat layer after coating the surface of a T-filter with ceramics or metal films in multiple layers using the sputtering method or the art method, it is difficult to prevent the reflection of light that occurs on the surface of the hard coat layer. Therefore, it was difficult to obtain a CRT filter with excellent anti-glare properties.

One possible method of applying a hard coat to the viewing surface side of a CRT filter in addition to anti-glare properties is to disperse silica having a fine particle size in the node coat layer. However, when a conventional flat CRT filter is provided with a nodular coating layer in which silica is dispersed, if the amount of silica added is increased until it has sufficient anti-glare properties, the CR
When used as a T filter, there was a problem in that the resolution of the peripheral portion of the screen was significantly reduced.

Furthermore, it is preferable that electric appliances such as CRTs use flame-retardant materials for fire prevention. However, usually
Polymethyl methacrylate, which is often used as a CRT filter, has excellent transparency but poor flame retardancy. In order to impart flame retardancy to polymethyl methacrylate, etc., it is necessary to blend various flame retardants into it, but it is necessary to blend flame retardants until it can be used as a material for electrical equipment without losing transparency. It was difficult.

An object of the present invention is to provide a CRT filter that solves the above-mentioned problems and has excellent resolution, anti-glare properties, scratch resistance, and flame retardancy.

[Means for solving problems]

The present inventors have studied to solve such problems,
The present invention has now been completed.

That is, the present invention provides a CRT filter made of polyvinyl chloride and having a shape capable of adhering closely to the CR7 surface, in which 3 to 30% by weight of silica having an average particle size of 1 to 50 μm is added to the surface opposite to the CRT. This is a CRT filter characterized by having a hard coat layer containing.

Polyvinyl chloride, which is a material for the CRT filter of the present invention, has self-extinguishing properties as a resin itself, so it is particularly flame retardant and transparent even without the addition of a flame retardant. In addition, in the present invention, as long as flame retardancy, transparency, and rigidity are not significantly lost,
Ultraviolet absorbers, infrared absorbers, antistatic agents, dyes, pigments, plasticizers, etc. may be added.

There are known methods such as injection molding, vacuum forming, and pressure forming as methods for molding a CRT filter into a shape that fits closely on a CRT, and by these methods, a CRT filter having a shape that can fit tightly on a CRT can be obtained.

Furthermore, a net made of conductive fibers or the like may be provided inside the filter to prevent electromagnetic waves, static electricity, etc. generated by the CRT.

In the present invention, hard coating agents that can be used include:
Examples include thermosetting hard coating agents such as silicone-based, epoxy-based, and phenol-based hard coating agents, and ultraviolet curable hard coating agents such as acrylic-based and urethane-based hard coating agents. Among them, polyvinyl chloride has a low heat deformation temperature, so it is particularly preferable to use an ultraviolet curable hard coating agent.

The silica added to the hard coating agent may be a fine powder of silicone resin in addition to a fine powder of silicon dioxide.

The average particle size of silica added to the hard coating agent is 1 to 50.
μm1 is preferably 3 to 20 μm. If the average particle size is less than 1 μm, sufficient anti-glare properties cannot be obtained, and if the average particle size exceeds 50 μm, C
This is undesirable in any case because it tends to cause moiré phenomena with the RT scanning line and dot pitch.

The optimum amount of silica to be added to the hard coat agent is 3 to 30% by weight, preferably 5 to 20% by weight in the hard coat layer. If the amount of silica is less than 3% by weight, sufficient anti-glare properties cannot be obtained;
If the
When attached to a CRT, it reduces the resolution and screen brightness.

The thickness of the hard coat agent containing silica varies depending on the average particle size and content of the fine silica powder contained and cannot be specified, but it is usually 1.2 to 5.0 times the average particle size of the silica.
Double thickness is preferred. The thickness is 1 or 2 of the average particle size of silica.
If it is less than twice that, more silica will be exposed on the surface of the hard coat layer, impairing the scratch resistance. If the thickness exceeds 5.0 times the average particle diameter of silica, the light transmittance of the CRT filter will be lowered more than necessary, which is not preferable.

In addition to silica, the hard coating agent applied to the surface of the CRT filter of the present invention may optionally include a diluent,
Dispersants, sensitizers, antistatic agents, dyes, pigments, fine metal powders, etc. may be added.

〔Example〕

The present invention will be explained below with reference to Examples.

In addition, the gloss level Gs (60°) is -7105 according to JIS.
The pencil hardness was measured according to JIS K-5400, and the scratch resistance was measured by rubbing the surface of the CRT filter with stainless steel wool and visually observing the presence or absence of scratches. A CRT filter was installed and the resolution of characters on the screen was visually observed, and flame retardancy was determined by lighting the end of the CRT filter and visually observing the degree of combustion.

Example I From a polyvinyl chloride sheet with a thickness of 2 mm, an aluminum mold for pressure forming was used to form a C into a shape that could be closely attached to a CRT surface.
An RT filter was manufactured. On the observation surface side, UV curable hard coating agent "Orestar χRA-" manufactured by Mitsui Toatsu Chemical Co., Ltd.
1458'' (trademark, solid content 80% by weight) After curing a coating solution containing 53.5% by weight, 10.9% by weight of silica powder with an average particle size of 5 μm and 35.6% by weight of ethyl acetate as a diluent. The hard coat agent layer was applied to a thickness of 8 μm, dried at 50°C for 5 minutes, and then heated at 80 W/c.
The surface was hardened by irradiating it with a high-pressure water lamp from a distance of 15 cm for 30 seconds. A surface hardness of 4H on a pencil hardness scale was obtained, and at the same time anti-glare treatment could be performed. The surface of the CRT filter was rubbed with stainless steel wool and visually observed for scratches, but no scratches were found. Even when the end of the CRT filter was lit on fire, the flame did not ignite any further and the flame retardance was sufficient.

Table 1 shows the glossiness Gs (60''), pencil hardness, scratch resistance, resolution, and flame retardance.

Example 2 - A polyvinyl chloride sheet with a thickness of 1.51 mm and an opening of 20 mm.
A polyethylene terephthalate net on which 0 mesh of metallic copper has been vapor-deposited is superimposed, a laminated sheet is obtained by heat pressing, and then an aluminum mold for air pressure forming is used to create a shape that allows the net to adhere closely to the CRT surface on the viewing side. CRT
A filter was manufactured. Glossiness on the observation surface side Gs (60)
was 27%.

The same hard coat agent as in Example 1 was applied to the observation surface side so that the thickness of the hard coat agent layer after hardening was 8 μm, and surface curing was performed under the same conditions as in Example 1. 4 on pencil hardness
A surface hardness of H was obtained. The surface of the CRT filter was visually observed for scratches with stainless steel wool, but no scratches were found. Even when the end of the CRT filter was lit on fire, the fire did not ignite any further and it was sufficiently flame retardant.

Table 1 shows the glossiness Gs (60''), pencil hardness, scratch resistance, resolution, and flame retardancy.

Comparative Example 1 A CRT filter was produced in the same manner as in Example 1, except that the amount of silica added to the hard coat agent was 40% by weight. The resolution was poor and the characters on the CRT could not be distinguished.

Glossiness Gs (60°), pencil hardness, scratch resistance, resolution,
Flame retardancy is shown in Table 1.

Comparative Example 2 A CRT filter whose surface was hard-coated and shaped to adhere closely to a CRT was obtained in the same manner as in Example 1, except that a polymethyl methacrylate sheet having a thickness of 2 mm was used in place of the polyvinyl chloride sheet.

The obtained CRT filter had a surface hardness of 7H on a pencil hardness scale, but when the end of the CRT filter was lit, the fire spread and no flame retardancy was observed.

Table 1 shows the glossiness Gs (60°), pencil hardness, scratch resistance, resolution, and flame retardancy.

Comparative Example 3 The CRT filter of Example 1 was used as a CRT filter without applying a hard coat agent. Although the resolution was fine, the glossiness Gs (60') was high. When used as a CRT filter, the illumination light was strongly reflected on the screen, and the scratch resistance was poor and easily scratched.

Table 1 shows the glossiness Gs (60°), pencil hardness, scratch resistance, resolution, and flame retardancy.

Table 1 (Effects of the Invention) The CRT filter of the present invention is manufactured by Plastitifux.
It simultaneously has the scratch resistance, anti-glare, and flame retardant properties required for RT filters. This prevents the reflection of illumination light on the surface of the CRT filter, allowing CRT operators to work without eye fatigue or resulting mental pain, and also allows them to clean the surface of the CRT filter. The surface will not be scratched even if you accidentally scratch it with a pencil or the like, and it can be used semi-permanently even if it is incorporated into a CRT.Furthermore, since the CRT filter is made of flame-retardant polyvinyl chloride, it will not damage the surface of the CRT housing. There is no problem in using it as a part.

Furthermore, since the CRT filter of the present invention has a shape that allows it to come into close contact with the CRT, the glossiness of the filter Gs
Even if the angle (60°) is low, the phenomenon of blurring of the display at a corner of the screen can be prevented and the resolution will not be lowered.

In addition, it has an excellent design and does not lose the curved surface of a conventional CRT screen and does not cause any discomfort.

The CRT filter of the present invention can be used not only for office automation equipment CRTs but also for consumer CRTs, and has a wide range of flf applications.

Claims (1)

[Claims] 1. In a CRT filter made of polyvinyl chloride and having a shape capable of adhering closely to the CRT surface, 3 to 30 particles of silica having an average particle size of 1 to 50 μm are placed on the opposite side of the CRT.
C characterized by having a hard coat layer containing % by weight
RT filter