JPS6211905B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an anti-diffuse reflection material for optical equipment, and more specifically, it is an anti-diffuse reflection material that is placed inside a camera, etc., to absorb incident surplus light rays, and has a fiber pile flocked on its surface to absorb the surplus light rays. The present invention relates to an anti-diffuse reflection material that can prevent troubles inside a camera or the like due to excess pile during flocking, and can enhance the absorption effect, even though the effect is enhanced. 2. Description of the Related Art Conventionally, the interiors of cameras and other optical devices have been coated with black paint or the like in order to prevent the reflection of excess light from the outside. However, in order to improve this antireflection effect, the surface of the black paint layer must be extremely smooth, making the coating method extremely difficult. An anti-reflection material is used on the surface of which fiber piles are flocked via a synthetic resin adhesive layer. With this anti-diffuse reflection material,
Excess light rays hit between the fiber piles on the surface and are absorbed through repeated bending diffraction, resulting in a light blocking rate of 90%.
It is said to reach more than that. However, when planting the fiber pile on the base,
There is inevitably some fiber pile (hereinafter referred to as surplus pile) that is not completely fixed to the base, and this can fall off inside the camera and cause trouble. In addition, most of the fiber piles had a circular cross section, and there was no black color, which has a high absorption capacity, so the effect of preventing random radiation was limited. The present invention aims to solve the above-mentioned drawbacks, and specifically, the cross section of the fiber pile protruding from the surface is formed into an ellipse or gourd shape, and the bending diffraction of the excess light rays is created as a black pile. The surface of the adhesive layer on the base and the exposed surface of the fiber pile are coated with flexible synthetic resin to prevent diffused reflection and prevent excess pile from falling off inside the camera during flocking. provide materials. Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 is a cross-sectional view of a part of a conventional anti-reflection material whose surface is flocked with fiber piles, and reference numeral 1 indicates a base, and back glue 6 is attached to the back surface of this base. A release paper 7 is laminated thereon. A synthetic resin adhesive layer 2 is applied to the surface of the base 1.
is formed, and a large number of fiber piles 3 are embedded and flocked through this layer 2. However, during this flocking, surplus piles 4 that are not fixed to the adhesive layer 2 are generated and cannot be completely removed even by suction, brushing, etc., and the surplus piles 4 that cannot be removed are small. Even if it does, it may fall off inside the camera, etc., causing trouble. Therefore, in the present invention, as shown in FIGS. 2 and 3, the fiber pile 3 electrostatically flocked through the adhesive layer 2 has an oval or gourd-shaped cross section, and is black in color. , further, adhesive layer 2
A coating layer 5 of flexible, synthetic resin, etc. is formed on the surface of the fiber pile 3 and the exposed surface of each fiber pile 3, and the surface of each surplus pile 4 is treated black with the coating layer 5. The excess pile 4 is covered and fixed to completely prevent it from falling off. Furthermore, since the cross section of the fiber pile 3 is oval or gourd-shaped, the reflection of excess light can be absorbed extremely effectively. That is, as shown in FIG. 3, when the fiber pile 3 has a gourd-shaped cross section, its cross section has two symmetrical circular arcs connected by a curved line, and this curved section is concave. Therefore, when an extra ray hits this,
The light beams are reflected in the radial direction by the two arcuate portions and spread out, hitting adjacent piles 3, and these reflected light beams themselves also interfere with each other and lose energy.
This phenomenon in which light rays are reflected and spread occurs in curved portions, and since there are many curved portions in a gourd-shaped cross section, a large proportion of light energy is absorbed, improving the effect of preventing diffuse reflection. On the other hand, if the cross section is circular,
The surface area is small, the spread of reflected light rays is constant, there is little interference between reflected rays, and the absorption rate of light energy is low. An example of the manufacturing process of the anti-diffuse reflection material of the present invention having the above structure is as follows. First, an adhesive is coated on the surface of a base (paper, cloth, plastic film, etc.), and fiber piles are electrostatically flocked using a conventional method. Natural and synthetic rubber latex, polyvinyl acetate, polyacrylic acid ester, water-based urethane, etc. are used as adhesives, but in the present invention, in order to further coat the fiber pile or adhesive layer with resin, A water-based urethane type is most preferable in terms of not being attacked at this time. Further, as the fiber pile, synthetic fibers such as rayon, vinylon, acrylic, nylon, etc. are suitable from the viewpoint of ease of processing. Moreover, the thickness is preferably 0.5 to 3 deniers, and the length is 0.1 to 0.5 mm, which is appropriately selected and used depending on the purpose. After hair transplantation, after drying by heating, perform absorption brushing as desired to remove excess pile.
A resin coating is applied on each fiber pile or on the adhesive layer, and by this treatment, the excess pile is completely covered and fixed, and troubles such as falling off inside the camera etc. can be completely prevented. The resin used for this resin coating must: 1 have good formability; 2. Must have superior strength. 3. Excellent weather resistance. 4. Be flexible. However, a synthetic resin solution containing butyl acrylate as a main component is suitable as a flexible resin because it is easy to coat by roller coating or the like and increases the absorption rate. Next, a release paper 7 is attached to the back surface of the base via a back glue 6 to obtain the anti-diffuse reflection material of the present invention. At the time of construction, after cutting out the mold according to the purpose, the release paper 7 is peeled off and attached to the inside of a camera or the like. Next, examples will be described. A water column urethane adhesive was applied to a cloth base, and a black dyed fiber pile (1 denier x 0.2 mm) with a gourd-shaped cross section was electrostatically flocked thereon by a conventional method, and then dried at 80 to 120°C. After suction brushing was performed to remove loose piles, a flexible resin coating material mainly composed of butyl acrylate was applied with a roller and dried at 60 to 120°C. The surface of each fiber pile was coated. It was covered with wood. On the other hand, as a comparative example, we electrostatically flocked the conventional fiber pile with a roughly circular cross section to create a fiber pile without surface coating.The fiber pile was blackened and the optical properties of both were changed by changing the incident angle of the light rays. was measured. The results are shown in Table 1, and it can be seen that the product of the present invention is more effective in preventing diffuse reflection than the conventional product, regardless of the angle of incidence of the light beam. In addition, a sellotape test was conducted to determine the presence or absence of excess fiber pile. That is, cellotape was attached to the surface of the anti-diffuse reflection material of this example and the conventional example, and a 100 g weight was moved back and forth twice on the tape, and then it was peeled off. As a result, the presence or absence of excess pile adhering to the cellophane tape was examined. A large number of fallen black fiber piles were observed to be attached to the cellophane tape according to the conventional example.
On the contrary, no fiber pile was observed on the cellophane tape of the present invention, indicating that the effect of the resin coating was extremely large. In addition, the anti-diffuse reflection material made of the product of the present invention was applied at a temperature of 70°C.
We left the product at ~80℃ and 100% humidity for one month and performed a wet friction test, but no changes such as hair loss were observed, confirming that it is sufficiently durable for use in tropical jungle regions. It was done.

【table】

【table】 [Brief explanation of the drawing]

FIG. 1 is a sectional view of a part of a conventional anti-diffuse reflection material, FIG. 2 is a sectional view of a part of an anti-diffuse reflection material according to an embodiment of the present invention, and FIG. 3 is a gourd-shaped one in the present invention. FIG. 2 is a perspective view showing a portion of a fiber pile in cross section. Reference numerals 1... Base, 2... Adhesive layer, 3... Fiber pile, 4... Surplus pile, 5... Coating layer, 6... Back glue, 7... Release paper.

Claims (1)

[Claims] 1. In an anti-reflection material for optical equipment, which is comprised of a fiber pile flocked to the surface of a base to be adhered to the inside of a camera or other optical equipment via an adhesive layer,
These fiber piles are composed of black piles with an oval or gourd-shaped cross section, while the surface of the adhesive layer and the exposed surface of each fiber pile are made of a synthetic resin with excellent flexibility, which is different from the adhesive. An anti-diffuse anti-reflection material for optical equipment characterized by being coated.