JPH10186114A - Pentagonal prism mask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to obviate the dislodgment of the particulates acting as antireflection fillers from an antireflection film and to prevent the production of a defective pentagonal prism unit by forming the antireflection film by electrodeposition coating. SOLUTION: A plating film 12 is formed on the front surface of a plastic mask material 11 by a plating stage on plastic. Further, a chemical conversion film 13 is formed by subjecting the skin of this plating film 12 to a chemical treating and an electrodeposition coating film 14 is formed on its surface. An example of the chemical conversion film 13 is a copper oxide film obtainable by oxidizing the plating film 12 when the plating film is copper. The electrodeposition coating film 14 as the antireflection film is formed by using an electrodeposition coating material contg. the particulates acting as the antireflection fillers in an electrodepositable resin and electrodepositiing this coating material on a metallic or nonmetallic mask base material by electrophoresis. If the mask base material is nonmetals, such as resins, the base material is subjected to electrodeposition coating after the base material is subjected to metal plating by a chemical plating treatment or to a suitable surface conducting treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antireflection pentaprism mask for cameras, 8 mm video cameras, and the like.

[0002]

2. Description of the Related Art Conventionally, spray coating has been mainly used as a method of forming a coating for preventing light reflection of a pentaprism mask.

However, in the case of spray painting,
Since the anti-reflection filler is dispersed more than twice the amount of the resin, the binder effect is small, the anti-reflection filler drops off after painting and adheres to the pentaprism box unit, and the entire pentaprism box unit becomes defective. There was a problem.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pentaprism mask having an antireflection film that does not cause the antireflection filler to fall off.

Another object of the present invention is to provide a pentaprism mask having excellent antireflection properties.

[0006]

According to the present invention, there is provided a pentaprism mask having an antireflection film on its surface, wherein the antireflection film is formed by electrophoresis using an electrodeposition coating material in which fine particles are dispersed in a resin. It is a coating film.

That is, according to the present invention, by forming the antireflection film of the pentaprism mask by electrodeposition coating, the fine particles acting as the antireflection filler do not separate from the antireflection film, and the defective pentaprism box unit is defective. Was prevented.

FIG. 1A is an exploded perspective view of a typical pentaprism box unit. The pentaprism 1 is a prism that refracts light from a lens and guides the light to a finder, and a spacer 2 is adhered via a tape 3. Also, a spacer 4 is bonded before the pentaprism. The pentaprism mask 6 is a component for clearly displaying the periphery of an image in the viewfinder, and has an anti-reflection film formed on the surface to prevent ghost and internal reflection. It is preferable that the condenser spacer 7 is adhered to the pentaprism mask, and the finder display mask adhered to or provided in the vicinity of the pentaprism mask 6 is also subjected to antireflection treatment using an electrodeposition coating film. The condenser lens 8 is a lens for brightening the viewfinder. After accommodating the condenser lens, the pentaprism mask 7 and the pentaprism in the holder 9, the pentaprism is fixed to the holder by a spring (not shown) with a penta-holding plate (not shown) covered. After the fixing, as shown in FIG. 1B, the gap between the pentaprism and the holder is sealed 10 with a sealing agent to prevent dust and the like from being mixed.

According to the present invention, the pentaprism mask and the antireflection filler of the antireflection film of the pentaprism mask caused by friction, vibration, etc. when the pentaprism is assembled into the holder are removed. This was prevented by doing so.

The electrodeposition coating film is formed by electrophoretic coating on a metal or nonmetal mask substrate using an electrodeposition coating material containing fine particles acting as an antireflection filler in an electrodepositable resin. Is done.

When the mask base material is a non-metal such as resin, metal plating by chemical plating or an appropriate surface conductivity treatment is performed, and then electrodeposition coating is performed.

The resin used for the electrodeposition paint is an acrylic or melamine, acrylic, epoxy, urethane or alkyd anionic or cationic resin.

As the anionic resin, for example, a resin obtained by introducing an anionic group such as a carboxyl group or a sulfone group into a resin such as an acrylic resin, a maleic resin, a polyester resin, an epoxy resin, or a polybutadiene resin is used. These resins are solubilized or dispersed in water with a basic substance such as triethylamine, diethylamine, dimethylethanol, or ammonia in the electrodeposition paint.

Examples of the cationic resin include resins such as epoxy resins, acrylic resins, urethane resins, polyamide resins, and polybutadiene resins into which cationic groups such as amino groups, ammonium bases, and imino groups have been introduced. Is used. These resins are solubilized or dispersed in water with an acidic substance such as formic acid, acetic acid, propionic acid and lactic acid in the electrodeposition paint.

In the anionic system, the mask substrate side is used as an anode,
In the case of a cation system, a cathode is used and electricity is supplied.

In this energization process, the anionic resin moves to the surface of the anode, which is a mask base material, and reacts with the acid (H ⁺ ) generated near the anode by electrolysis of water to form an electrodeposition coating film. Precipitates. In addition, the cationic resin moves to the surface of the cathode serving as a mask base material, reacts with a base (OH ⁻ ) generated near the cathode by electrolysis of water, and deposits as an electrodeposition coating film. Next, the mask base material is taken out of the electrodeposition tank, washed with water, and then drained. The electrodeposition coating film thus formed is preferably further subjected to a curing treatment by heating or light irradiation to improve weather resistance and chemical resistance. In the case of an anionic resin, for example, a hydroxyl group or a methylolated amide group introduced into the anionic resin is reacted with an amino resin such as a melamine resin or a benzoguanamine resin to cure the anionic resin.
At this time, the amino resin acts as a crosslinking agent. Further, there is curing by oxidative polymerization utilizing a double bond of an anionic resin. In the case of cationic polymerization, for example, a curing method of reacting an isocyanate compound with a hydroxyl group of a cationic resin or an amino group introduced for cationization, a curing method by oxidative polymerization, a curing method by transesterification, and the like. To cure.

Fine particles acting as an antireflection filler include metal powders such as aluminum, copper, nickel and silver; metal foils and short metal fibers; metal oxides such as antimony oxide, indium oxide and tin oxide; carbon fibers; Carbon black, graphite powder and the like are used.

The surface roughness of the electrodeposition coating film formed on the mask substrate is preferably 1.7 to 5 μm (Ra: center line average roughness, JIS B0601-1982) from the viewpoint of preventing reflection.

As the fine particles, alumina oxide, diatomaceous earth, activated carbon, zirconium oxide, porous carbon and a silicon oxide compound are preferred, and those having a porosity of 80% or more are preferred. Particularly, a silicate compound is preferable.

Regarding the dispersion amount of the fine particles,
The range of 5 to 60 parts by weight relative to 00 parts by weight is suitable.

The porosity (%) evaluates the porosity of the fine particles, and is calculated by the following equation.

[0022]

[Outside 1] s: apparent specific gravity (density) d: true specific gravity (density)

For example, when the d value of the porous aluminum oxide is 3.8 and the s value is 1, the porosity of the alumina oxide is 73.1%.

[0024]

FIG. 2 and FIG. 3 show a typical sectional configuration example of a pentaprism mask according to the present invention.

FIG. 2 shows that a plating film 12 is formed on the surface of a plastic mask material 11 by a generally known plating process on plastic, and further, a chemical conversion film 13 is formed by chemically treating the skin of the plating film. FIG. 4 is a cross-sectional view when an electrodeposition coating film 14 is formed on the surface. An example of the chemical conversion film is a copper oxide film obtained by oxidizing the plating film when the plating film is copper.

FIG. 3 is a cross-sectional view when a plating film or a chemical conversion film 16 is formed on a surface of a metal material 15 by a generally known plating process or a chemical conversion process, and an electrodeposition coating film 14 is formed on the surface. FIG.

However, the plating film or the chemical conversion film can be omitted. As described above, the electrodeposition coating member has a remarkably roughened film surface due to the eutectoid effect of the porous fine particles, and the light-shielding property against light or the antireflection is improved.
Further, by using an electrodeposition coating film, an electrodeposition coating member having high scratch resistance, high weather resistance, high adhesion or high solvent resistance can be formed.

The surface roughness of the electrodeposition coating film is preferably 2
４4.5 μm. The surface roughness of the electrodeposition coating film is
The finer the better, the number of roughness peaks (measurement length 2 mm) whose distance from the average line of the roughness curve is 2.5 μm or more is 30.
The number is preferably at least 40, especially at least 40. The number of roughness peaks is the sum of the number of peaks and the number of valleys on the basis of the average line.

The particle size of the fine particles differs depending on the size. The gloss tends to be high when the particle size is small, and the gloss tends to be low when the particle size is large. Cause, preferably 5
７０70 μm, especially 10 to 40 μm. The particle size of the particles is a value measured using a centrifugal sedimentation type particle size distribution analyzer. What was actually used as this measuring instrument was SAC
P-3 (manufactured by Shimadzu Corporation).

The dispersion amount of the fine particles in the electrodeposition coating film is correlated with the ratio to the resin component. If the amount of the fine particles is excessive, the fine particles fall off and cause dust after completion of the product. Preferably, the range is 2 to 50 parts by weight, particularly 5 to 40 parts by weight, based on 100 parts by weight of the resin. Regarding the shape, either a fixed form or an irregular form may be used. These are put together with a resin in a prescribed amount into a container and dispersed by a ball mill for 24 hours or more, and then diluted with demineralized water, preferably to 5 to 20% by weight, especially , 7-1
7 wt% solids. Thereafter, a pigment is added as necessary to adjust the pH to 7.5 to 8.5 to obtain an electrodeposition paint.

Next, as a light-shielding or anti-reflection pentaprism mask member, an anion is used as an anode with respect to a counter electrode in anionic electrodeposition coating, and an object is used as a cathode in cationic electrodeposition coating, and a bath temperature of 20 to 25 is used. If necessary, apply a voltage of 70 to 200 V, a current density of 0.5 to 5 A / cm ² , and a treatment time of 1 to 5 minutes in the range of ° C.
It is cured for 20 to 120 minutes in the range of ~ 200 ° C to complete.
At this time, the thickness of the electrodeposition coating member can be an arbitrary film thickness of 10 to 50 μm. At this time, the content of the porous fine particles is preferably 7 to 50% by weight, particularly,
10 to 40 wt%.

As described above, the present invention remarkably promotes light-shielding or antireflection by light by the eutectoid effect by dispersing fine particles in an electrodepositable resin to form an electrodeposition coating film. As a result of measuring the light-shielding property or the anti-reflection effect with a gloss meter, a gloss of 0 to 2 was obtained at an incident angle of 60 ° and a reflection angle (light reception angle) with respect to the horizontal plane. Note that a gloss of 0 indicates that reflected light is not measured. What was actually used as this measuring instrument was GLOSS METER UGS
-300A (manufactured by Nippon Denshoku Industries Co., Ltd.).

In terms of the physical properties of the coating film, there is no generation of dust due to, for example, fine particles falling off as seen in spray coating, there is no problem in adhesion, and the hardness is 3H or more. Solvent resistance is unchanged even with methyl ethyl ketone. And the weather resistance is 1
000 hours or more.

The eutectoid quantity of fine particles is measured by thermogravimetric analysis. Further, the eutectoid content of the fine particles is confirmed by an X-ray microanalyzer.

The measurement of Ra was carried out by TOKYO SEIMI.
It was measured by Surfcom manufactured by TSU.

As a black colorant added to exhibit light-shielding properties, a material having excellent light-absorbing properties such as carbon black, titanium monoxide, and magnetite is used.

When a black coloring material is not contained in the electrodeposition coating film, it can be used as a member having an excellent regular reflection preventing appearance.

Example 1 Aqueous resin solution A of acrylic / melamine resin clear 15 wt% (trade name: Honey Bright H-1, manufactured by Honey Kasei Co., Ltd.) was adjusted to a total volume of 2 liters with demineralized water. To dilute and obtain a black film, carbon black 1.5 wt% as a black pigment
Was added to obtain an electrodeposition paint (1).

The aqueous resin solution A has a porosity of 73
% Aluminum oxide particles having a particle size of 10 μm in a weight ratio of 5%.
wt% and dispersed in a ball mill for 24 hours.
The solution was diluted to a total volume of 2 liters with demineralized water, and in order to obtain a black film, 1.5 wt% of carbon black was added as a black pigment to obtain an electrodeposition paint (2).

The porosity is 85% with respect to the aqueous resin solution A.
Silica soil (trade name: Brelite # 4, manufactured by Sanshin Seisakusho)
5% by weight of particles having an average particle diameter of 10 μm are added in a weight ratio,
After being dispersed in a ball mill for 24 hours, the mixture was diluted with demineralized water so that the total volume became 2 liters, and a black pigment was obtained.
t% was added to obtain an electrodeposition coating material (3).

The conditions of the electrodeposition coating are pH 8.0 to 8.2,
The bath temperature is set to 20 to 25 ° C.
using a stainless plate of mm ^t, minimum 50V voltage applied to the DC power supply, under elevated conditions at each 25V intervals at the maximum 200V, alkali degreasing a steel plate treated with zinc phosphate as a penta prism mask substrate (trade name : Pakna, manufactured by Yuken Chemical Co., Ltd.)
Electrodeposition was applied for 2 minutes at each applied voltage. Next, it was washed with water, finally washed with demineralized water, and baked in an electric furnace at 150 ° C. ± 1 ° C. for 30 minutes to complete. The finished pentaprism mask member was measured for glossiness, Ra, peak number of roughness, and eutectoid content of fine particles in the electrodeposition coating film. The results shown in Table 1 were obtained. Further, as a result of actually assembling a pentaprism box unit as shown in FIG. 1 (B) and assembling it in a camera, no dropout of the aluminum oxide, diatomaceous earth and carbon black from the electrodeposition coating film was observed at all. .

In preparing the electrodeposition paints (1) to (3), instead of the aqueous resin solution A, 15% by weight of acrylic / melamine resin clear (trade name: Honey Bright C-1)
L, manufactured by Honey Kasei Co., Ltd.) A similar result was obtained when the aqueous resin solution B was used. In addition, coating film characteristics (weather resistance 1000
(Including time) did not differ. However, the baking temperature after electrodeposition was 95 ° C. ± 1 ° C.

[0043]

[Table 1]

FIGS. 4 to 9 show the roughness curves for the examples of the compositions (2) having a voltage of 75 V, 100 V and 150 V and the composition (3) having a voltage of 50 V, 75 V and 100 V.

(Comparative Example) 45 parts of graphite as a matting agent, and 2 parts of carbon black as a black pigment to obtain a black coating film, for 20 parts of epoxy / melamine resin clear,
Then, 35 parts of an organic solvent (thinner) was added to obtain a spray paint.

The conditions for the spray coating are as follows. The same organic solvent as described above is used to adjust the viscosity of the spray coating. 17 in 4
After adding so as to be within the range of 20 seconds, the paint is put into the spray gun, and the air pressure is 1.5 kg / cm ² , the distance to the object to be coated is 30 cm, and the pentaprism mask shown in the booth (FIG. 11A). Coating film 20 to both sides (formed one by one) of finder display mask (material phosphor bronze)
A 30 μm thick film was formed and baked in an electric furnace at 150 ° C. ± 1 ° C. for 30 minutes to complete the process.

The gloss, Ra, and the number of roughness peaks of both completed masks were measured. The results are shown in Table 1.
However, although it has light-shielding properties, graphite fine particles fall off on the condenser lens shown in FIG. 1 during the camera assembling process, resulting in dust defects and poor adhesion due to contact between components, which poses a major problem in terms of quality. occured.

(Example 2) Acrylic melamine resin clear 15 wt% (trade name: Honey Bright C-1L, manufactured by Honey Kasei Co., Ltd.) is used. 85% porosity
Activated Carbon (trade name: FM-150, manufactured by Catala Industries)
Particles having an average particle diameter of 25 μm were separately added at a weight ratio of 10 wt%, dispersed in a ball mill for 24 hours, and then diluted with demineralized water so that the total volume became 2 liters. 1.5% by weight of carbon black was added to obtain an electrodeposition paint.

Electrodeposition conditions were as follows: pH 8.0 to 8.2, bath temperature 20 to 25 ° C., an object to be coated as an anode, and a counter electrode of 0.5 m
From 50V DC applied voltage using a stainless steel plate of m ^t,
A plastic material (ABS) is used as a pentaprism mask substrate under the condition that the voltage is increased at a maximum of 200 V at 25 V intervals.
/ PS) was degreased on the surface, treated with a chromic acid-sulfuric acid-water etching solution at 70 ° C. for 10 minutes, and then treated as a sensitizer solution with a composition of stannous chloride 30 g / 1 hydrochloric acid 20 ml / 1 at room temperature for 2 minutes to obtain a catalyst treatment. After the surface is treated with palladium to make it conductive, electroless copper plating (trade name: OPC700,
5 hours after treatment at 50 ° C for 2 hours.
Was formed. Thereafter, the alkali chemical solution bath temperature is 50 ° C.1
After forming a chemical conversion film on the surface by copper plating and subjecting it to electrodeposition treatment for 2 minutes at each applied voltage, it was washed with water, washed with demineralized water, and further heated in an electric furnace at 95 ° C. ± 1 ° C. 3
Baking for 0 minutes completed. Thereafter, the gloss, Ra, the number of roughness peaks, and the eutectoid content of the fine particles were measured, and the effects shown in Table 2 were obtained. Further, as a result of actually assembling and evaluating the camera, the result was good as in Example 1.

[0050]

[Table 2]

[0051]

As described above, according to the present invention,
By forming the anti-reflection film of the pentaprism mask by electrodeposition coating, fine particles acting as anti-reflection fillers do not separate from the anti-reflection film, thereby preventing defective pentaprism box units. .

[Brief description of the drawings]

FIG. 1A is an exploded perspective view of a pentaprism box unit. (B) is a perspective view of a pentaprism box unit.

FIG. 2 is a schematic sectional view of a pentaprism mask member according to the present invention.

FIG. 3 is a schematic sectional view of another pentaprism mask member according to the present invention.

FIG. 4 is a roughness curve diagram of an electrodeposition coating film.

FIG. 5 is a roughness curve diagram of an electrodeposition coating film.

FIG. 6 is a roughness curve diagram of an electrodeposition coating film.

FIG. 7 is a roughness curve diagram of an electrodeposition coating film.

FIG. 8 is a roughness curve diagram of an electrodeposition coating film.

FIG. 9 is a roughness curve diagram of an electrodeposition coating film.

Claims (11)

[Claims] 1. A pentaprism mask having an antireflection film on its surface, wherein the antireflection film is an electrodeposition coating film formed by electrophoresis using an electrodeposition coating material in which fine particles are dispersed in a resin. Pentaprism mask. 2. A pentaprism mask, wherein an anti-reflection film is formed on a surface of a metal substrate. 3. The electrodeposition coating film has a surface roughness of 1.7 to 5 μm.
The pentaprism mask according to claim 1, wherein 4. The electrodeposition coating film has a surface roughness of 2 to 4.5 μm.
The pentaprism mask according to claim 1, wherein 5. The method according to claim 1, wherein the number of roughness peaks whose distance from the average line of the roughness curve of the electrodeposition coating film is 2.5 μm or more is 30 or more (measurement length 2 mm). Penta prism mask. 6. The pentaprism mask according to claim 5, wherein the number of roughness peaks is 40 or more. 7. The pentaprism mask according to claim 1, wherein the fine particles are a silicate compound. 8. The pentaprism mask according to claim 1, wherein the fine particles have a porosity of 80% or more. 9. The pentaprism mask according to claim 1, wherein the fine particles have an average particle size of 5 to 70 μm. 10. The pentaprism mask according to claim 1, wherein the electrodeposition paint contains a black coloring material for providing a light-shielding property to the electrodeposition coating film. 11. The pentaprism mask according to claim 10, wherein the surface gloss of the electrodeposition coating film is 2 or less.