JPS58104965A - Reflection preventing paint - Google Patents

Abstract

PURPOSE:To prepare the titled paint giving matted surface without reducing the blackness, forming a thin film having excellent reflection-preventing property to an optical part, and capable of preventing the flair and ghost, by using bone black and artificial graphite together with carbon black as the extender pigment. CONSTITUTION:The objective paint can be prepared by compounding (A) 150pts. of an epoxy-type ester resin and melamine resin, (B) 3pts. of carbon black as black coloring pigment, and (C) 100pts. of extender pigment composed of (i) 90pts. of bone black (preferably a calcium bone black containing 20-30% carbon and having desirable blackness) and (ii) 10pts. of artificial graphite.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to 5 anti-reflective paints and 1% to anti-reflective paints used to prevent the occurrence of flare and ghosts due to light reflection at parts of optical parts etc. It is something.

The general composition of such anti-reflective paints consists of main film-forming elements that form a continuous film, mostly organic polymer substances, and plasticizers and thickeners added to improve the performance of the paint film. Paint film forming elements such as agents, pigments which are insoluble powders added for the purpose of adjusting the color and gloss of the paint film, giving thixotorby properties, and reinforcing mechanical properties and weather resistance, and coatings such as paints. It consists of film-forming auxiliary elements such as solvents, which are added for the purpose of imparting fluidity and making it easier to apply. In paints intended to prevent reflection, the color tone of the paint is made blacker to reduce the light energy reflected from the paint film, and the surface of the paint film is roughened to a matte state to reduce the amount of light that enters the paint. The matte design that diffuses the light is mainly done using pigments.

According to the prior art, carbon black is widely used to blacken paints, and silica and Merck are used as extender pigments with a matting effect to adjust the gloss of paints.

Calcium carbonate or the like is added, and the amount of addition is adjusted by examining the appropriate particle size and shape and compatibility with the main elements of coating film formation. however.

Conventional anti-reflective paints prepared in this way.

Although silica, talc, calcium carbonate, etc. added as extender pigments can reduce the gloss to some extent, these conventional extender pigments are pigments that do not have black coloring properties, and do not inherently have black coloring properties. It lowered the black tone of the paint, and as the amount added increased, the blackness tended to be lost and the paint film became whitish. On the other hand, the amount of carbon black, which is a black coloring pigment, cannot be increased unnecessarily due to its oil absorption with the organic polymeric substance that is the main component of coating film formation. Although the amount of the organic polymer substance used varies depending on the rice species, when used in combination with an extender pigment, the limit is generally 6 to 54. There was a problem in that carbon black could not compensate for the decrease in blackness of the filter paint.

Anti-reflective paint formulated with the addition of conventional extender pigments,
An example of the reflection results on the coated film surface when the part of an optical system component that reflects light is painted using a coating method such as spraying or brushing is generally as shown in the table below. This table also shows that it is difficult to obtain low reflection with conventional anti-reflection paints, and that it is necessary to take measures to further attenuate the reflected light energy when the angle of incidence of incident light is at or above the critical angle. found.

The object of the present invention is to provide an optical antireflection coating that has blackness and low reflection by using a pigment that has blackness and also has a matte effect.

According to the present invention: J is an anti-reflection paint used to prevent the occurrence of flare or ghost due to light reflection at a light-reflecting part of an optical component, etc., comprising carbon black as a black coloring pigment; Reflective material containing bone black, which is used as a finely divided extender pigment that is black and has the effect of a matting agent, and artificial graphite, which is used as an extender pigment that is black and has the effect of being a matting agent and has high hiding properties. A preventive paint is obtained.

This invention replaces conventional extender pigments, such as silica, talc, and calcium carbonate, which do not have black coloring properties by themselves.
Bone black obtained by carbonizing animal bones by carbonization is used as an extender pigment that can lower the gloss of the paint without impairing the blackness required for antireflection paint. For example, calcium bone black containing 20 to 60% of cariner and having a preferable degree of blackness is used. Bone black has the function as a black coloring pigment as well.

Like conventional silica, talc, calcium carbonate, etc. for the purpose of adjusting gloss, imparting thixotropy, or improving mechanical properties and weather resistance, it can be mixed in relatively large amounts, so it can be used as a bone black extender pigment. By using it, sufficient matteness can be brought out without impairing the blackness of the paint, and the antireflection effect can be enhanced. In addition, the present invention uses artificial graphite as an extender pigment that can expand the coating surface per unit area of the object to be coated, absorb more light on the coating surface, and improve the hiding performance of the coating. By utilizing the black property of artificial graphite, it can function as a black coloring pigment, and by utilizing the scaly property of artificial graphite, which is large per volume of the powder itself,
The area of contact with organic polymer substances and coloring pigments, which are the main elements of coating film formation, is also increased, making it possible to increase the hiding properties of the paint and the surface area of the coating film. By using artificial graphite as an extender pigment, the blackness of the paint is not impaired, and the anti-reflection performance is sufficiently maintained even with a thin film, compared to the drawback of conventional anti-reflection paints which have thick and fluffy coatings. I can do it. Further, according to the present invention, although the amount of carbon black added as a black coloring pigment is limited due to the oil absorption amount with the organic polymer substance that is the main component of coating film formation, it can be added as an extender pigment. Since the bone black and artificial graphite used also function as black coloring pigments, it is possible to sufficiently avoid the decrease in blackness of the paint caused by the addition of conventional extender pigments.

Examples of the present invention will be described below.

Example 1 100 parts K of an epoxy ester resin having good adhesion to the object to be coated, such as metal, was used as the main component for forming a coating film.

3 parts carbon black, 90 parts bone black.

10 parts of artificial graphite were added, 240 parts of xylene was added as a solvent, and the mixture was mixed and stirred in a ball mill to form a paint. In order to cause the polymerization reaction of the polyester resin and to improve the spreadability of the paint, 55% of the melamine resin was added to the resulting mixture.
Paint I was obtained by adding 0 parts.

Example 2 5 parts of carbon black, 180 parts of bone black, 20 parts of artificial graphite were added to 100 parts of epoxy ester resin, 240 parts of xylene was added as a solvent, and the mixture was mixed and stirred in a ball mill to form a paint. 50 parts of melaquin resin was added to the resulting mixture to obtain a paint.

Example 3 6 parts of carbon black and 100 parts of bone black were added to 100 parts of epoxy ester resin.

240 parts of xylene was added as a solvent and mixed and stirred in a ball mill to form a paint. 50 parts of melamine resin was added to the resulting mixture to obtain a paint layer.

Example 4 To 100 parts of melamine resin, 6 parts of carbon black, 290 parts of bofufu, 10 parts of artificial graphite were added, 150 parts of xylene solvent was added, and the mixture was mixed and stirred in a ball mill to form a paint to obtain paint ■. .

Example 5 Carbon to 100 parts of epoxy ester resin.

5 parts of black, 260 parts of Bonobu 2F and 10 parts of artificial graphite were added, 120 parts of xylene was added as a solvent, and the mixture was mixed and stirred in a ball mill to form a paint. 50 parts of melamine-based resin was added to the resulting mixture to obtain paint (2).
1' After adjusting the paint viscosity using xylene as a solvent for each of paints 1 to Vik formulated according to Examples 1 to 5.

As shown in Figure 1, part 1# of optical components where light is reflected.
When a coating film 2 is formed by coating using a coating method such as C spray or mackerel, the incident light 3 is absorbed by the coating film 2 or becomes reflected light 4 which is attenuated.

Alternatively, it became dispersed reflected light 5 and was diffusely reflected, making it possible to prevent harmful reflection from the surface of the optical component.

The antireflection performance of the coatings formed by paints 1 to 2 was as shown in the table below. The table below shows the dilution ratio with paint thinner for each paint - V and the reflectance according to each reflection angle at the paint film thickness, and compared to the previous table showing the reflection results of the paint film with conventional paint A-4. Therefore, the reflectance obviously decreases and you can get a low reflection.

A comparison of the characteristics of paints 1 to 2 was as follows. Even when the dilution ratio of Paint 1 was changed, the anti-reflection properties of the surface did not change, and even with a relatively thin film thickness, the anti-reflection effect was obtained. Paint ■ had the same anti-reflection properties as Paint I, but because the resin content was lower than the pigment, the paint spread was somewhat slow, and when the dilution ratio was increased, the paint film tended to become smeared. .

In order to obtain this satisfactory coating film, it was necessary to apply a relatively thick amount of paint. Paint I has a slightly smoother coating surface than paints I and I, and as the reflection angle increases, the reflectance increases, and the antireflection effect is better (or worse).

Paint (2) has a different resin from paint (1), but its reflection characteristics (1) are slightly inferior to paint (I), but the paint spreads well and has a comparatively thin film coating effect. Paint ■ has a black color over the entire coating, but it has a slightly glossy coating and has no overall antireflection effect.

From the side view of Example 9 above, the conditions for achieving anti-reflection properties in a uniform thin film are to add artificial graphite in an amount that does not worsen the blackness of the paint and gives an appropriate level of unevenness to the paint surface. That's good.

It is also desirable to add an appropriate amount of bone black to the extent that it does not adversely affect the elongation of the resin, taking workability into account, and to configure the paint to bring out the black coloring effect of carbon black.As an anti-reflection paint for optical system parts. In addition to optical properties, there are various requirements such as the texture and color tone of the coating surface, and dimensional accuracy in fitting with other parts, so the composition of the coating is not uniform depending on the part where it is used. The amount of carbon black that can achieve the highest blackness is approximately 2 to 5 parts per 100 parts of resin, and the amount of bone black is 40 to 12 parts.
0 parts 1 Artificial graphite is allowed to stand in paint (6 parts to the extent that it does not settle)
It is preferable to set it as 20 parts.

As explained above, in the present invention, since the antireflection paint using carbon black as a black coloring pigment contains bone black and artificial graphite as extender pigments, the paint can be sufficiently matted without any loss in blackness. In addition to maintaining the anti-reflection performance with a thin film,
Compared to conventional antireflection paints, it has the effect of being significantly superior in terms of blackness and reflectance.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the relationship between a coating film made of the antireflection paint of the present invention, incident light, and reflected light. 1... Optical component, 2... Coating film, 3... Incident light. 4.5...Reflected light. Agent Patent attorney Sho Watanabe Nisaku/U7'J Procedural amendment dated April 1980, Director General of the Patent Office Haruki Shimada1, Indication of the case 1982-1 - Patent Application No. 2024183, Make amendments Relationship with Patent Applicant 4, Agent 227 Phone: 045-971-1
370 Address: 206-1165 Ichigao-cho, Midori-ku, Yokohama-shi, Kanagawa Prefecture Number of inventions increased by 7 due to amendment Contents of amendment subject to amendment (1) Page 6 of the specification, line 6 “Thickness per volume” Corrected "thickness of surface area per volume". that's all

Claims (1)

[Scope of Claims] 1. An anti-reflective paint containing carbon black as a black coloring pigment; 6. An anti-reflective paint containing bone black and artificial graphite as extender pigments. 2. The antireflection paint according to claim 1, which contains 3 parts of carbon black, 90 parts of bone black, and 10 parts of artificial graphite to 150 parts of epoxy ester resin and melamine resin. .