JP3034111B2 - Light-emitting cover materials for lighting equipment, etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floodlight cover material used for a cover material of a lighting fixture, a board of an electric signboard, and the like.

[0002]

2. Description of the Related Art To make the above colorless and transparent cover material of a synthetic resin such as a polyvinyl chloride resin by a general formulation, a tin-based heat stabilizer such as malate tin or mercapto tin, a lubricant, a plastic, What is necessary is just to shape | mold the material which mix | blended predetermined amount of general additives, such as an agent, into a predetermined shape.
Lighting equipment using a cover material made of polyvinyl chloride resin made with such a general prescription has a sufficient color inside the room with light emitted from a light source such as a fluorescent lamp because the cover material is colorless and transparent. It is possible to illuminate with bright illuminance. However, if the cover material is colorless and transparent, the real image of the light source built into the lighting fixture is seen through the cover material.

[0003] On the other hand, recently, the above-mentioned cover material called a louver of a lighting fixture hardly allows a real image of an internal light source to be seen from the outside (for example, indoors). It has been required that the illuminance be maintained high enough to every corner.

Incidentally, the total light transmittance is sometimes used as a concept as an index as to whether or not a substance easily transmits light. The total light transmittance is a parallel light transmittance indicating a rate at which parallel rays emitted from a light source pass straight through a material, and a light diffusivity indicating a rate at which parallel rays emitted from a light source are diffused when passing through a substance. It is expressed by the sum of On the other hand, the ratio of the light diffusion amount to the total light transmission amount may be expressed as a haze value (cloudiness). Therefore, in the cover material of the lighting fixture, the larger the total light transmittance, the more light from the light source is projected into the room, and the higher the light illuminance in the room, and the higher the light diffusion rate, the more uniform the illuminance in each part of the room. It can be said that the greater the haze, the higher the haze of the substance and the more difficult it is to see the light source through the substance.

[0005] Therefore, a colorless and transparent cover material formed by molding a polyvinyl chloride resin by a general prescription has a satisfactory haze value, although it satisfies the total light transmittance. However, it cannot be said that the above-mentioned requirement for the cover material can be satisfied.

Therefore, when a cover material is made of a polyvinyl chloride resin, conventionally, in addition to a general additive such as a tin-based heat stabilizer, a lubricant, and a plasticizer, calcium carbonate or an oxide is added to the polyvinyl chloride resin. Additives such as titanium that exhibit a light concealing effect are mixed, and the whiteness of the cover material is used to make the real image of the light source difficult to see by utilizing the whiteness of the additives.

[0007]

However, in the above-mentioned conventional cover material having a whiteness with a white additive (hereinafter, referred to as a white additive) such as calcium carbonate or titanium oxide, a colorless and transparent polychloride is used. If the compounding ratio of the white additive to the vinyl resin is increased to such an extent that the real image of the light source is difficult to see through the cover material, the light source is dispersed because the white additive is scattered in the polyvinyl chloride resin layer. Most of the light emitted from the cover material is concealed by the white additive, so that the total light transmittance of the cover material becomes too low, so that the illuminance in the room cannot be increased to a satisfactory value or the required intensity cannot be satisfied. . Also, if the mixing ratio of the white additive is reduced to increase the illuminance in the room to a satisfactory value, the light concealing effect and the whiteness are insufficient, so that the real image of the light source can be easily seen through the cover material. Further, the mere use of the white additive does not increase the light diffusivity of the cover material, so that it is impossible to improve the uniformity of the illuminance of each part in the room.

The present invention has been made in view of the above circumstances, and by increasing the light diffusivity as compared with a conventional cover material, it is possible to maintain both the total light transmittance and the haze value sufficiently high. Moreover, an object of the present invention is to provide a light-projecting cover material such as a lighting fixture capable of expressing white.

[0009]

According to the present invention, a light-transmitting cover material such as a lighting device according to the present invention comprises a base layer made of a transparent synthetic resin and transparent beads having a refractive index different from that of the base layer and having a particle diameter of 5 to 50 μm. A core layer that is scattered, and a transparent synthetic resin having a thickness of 0.1 to 0.5 mm, which is laminated and integrated with the core layer, is mixed with 0.02 to 0.09 parts of white powder such as titanium oxide, and is scattered. A surface thin layer.

[0010]

According to the light-projecting cover material having this structure, the light beam of the light source entering the base layer is refracted when entering or exiting the bead or is reflected on the bead surface and passes through the base layer. Increases light diffusion, and because the base layer and beads are both transparent, maintains a total light transmittance comparable to the cover material made with the general formulation described at the outset, but nevertheless all light The ratio of the light diffusion amount to the transmission amount increases, and the haze value increases.

When the light beam passes through the thin surface layer, a part of the light is reflected by the white powder contained in the thin surface layer, and a white color is developed , and satisfactory whiteness is obtained.

[0012]

FIG. 1 is a sectional view for explaining a cover material A according to an embodiment of the present invention. The cover material A has a core layer 1 in which transparent beads 3 having a refractive index different from that of the bait layer 2 and a particle diameter of 5 to 50 μm are scattered on a base layer 2 made of a transparent synthetic resin, Laminated and integrated, 0.02 of white powder 5
0.09 parts of a transparent thin synthetic resin layer 4 having a thickness of 0.1 to 0.5 mm, which is dispersed and dispersed. The surface thin layer 4 may be laminated and integrated only on one surface of the core layer 1 or may be laminated and integrated on both surfaces. However, when used as a louver of a lighting fixture, the surface thin layer 4 is laminated and integrated only on one surface on the surface side. Alternatively, the total light transmittance may be increased.

A light source is installed on the other side of the cover member A, which has the surface thin layer 4 laminated and integrated only on one surface of the core layer 1, and the light source is turned on. Most of the emitted light passes through the base layer 2 while repeating refraction and reflection when entering the base layer 2, entering and leaving the beads 3, and exiting from the base layer 2. . As a result, the real image of the light source becomes difficult to see through the base layer 1. This light diffusion property is the particle size of the beads 3.
When the particle size is 50 μm or more, the particle size decreases.
Should be below. Further, since both the base layer 2 and the beads 3 are transparent, light rays are hardly blocked by them. Then, light from the outside is reflected by the surface thin layer 4 to exhibit white. When the light from the light source passes through the surface thin layer 4, a part of the light is concealed by the white powder 5, so that the total light transmittance of the cover material A is reduced correspondingly. The thickness of 4 is less than 0.5mm
The amount of Sanishi white powder 5 by previously reduced with 0.02-0.09 parts, it is possible to suppress to a minimum the drop in total light transmittance due to the hiding effect of the white powder 5. Note that if the thickness of the surface thin layer 4 is too small, it is difficult to develop white color, so the thickness should be 0.1 mm or more. As the transparent resin and the transparent beads 3 used for the base layer 2, vinyl chloride, acryl, polycarbonate resin, styrene, acrylic styrene copolymer and the like are used, and these have different refractive indexes. For example, the refractive index of vinyl chloride is about 1.52, while the refractive index of acrylic is about 1.47, so they have different refractive indices, and light is refracted or reflected when passing through the beads 2. It is transmitted while being scattered. Also, the acrylic polymer beads softening point is higher than the polyvinyl chloride resin does not occur a situation broken during molding.

In the cover material A having this configuration, while the total light transmittance and the light diffusivity increase, the parallel light transmittance decreases, and as a result, the haze value increases. Also,
White color due to the white powder scattered in the surface thin layer 4 is exhibited. Therefore, when the cover material A is used for a lighting fixture, each part in the room is uniformly illuminated with a sufficiently large illuminance,
Nevertheless, the real image of the light source built into the lighting fixture becomes difficult to be seen from the outside, and is visually recognized as the white cover material A.

In this cover material A, the core layer 1 comprises, for example, an additive necessary for obtaining a generally transparent base layer 2 such as a tin-based heat stabilizer, a lubricant and a plasticizer in a polyvinyl chloride resin. By blending a predetermined amount of highly transparent beads 3 made of an acrylic polymer and molding them by a known method such as extrusion or pressing, the beads 3 can be easily and inexpensively manufactured. In addition, the white powder scattered in the surface thin layer 4 includes:
One or a plurality of inorganic white powders such as titanium oxide TiO ₂ , calcium carbonate CaCO ₃ , and silicon oxide SiO ₂ are selected, but TiO _{2 which} is most excellent in obtaining whiteness is preferably used.

Next, Table 1 shows the compositions of the core layer and the surface thin layer in the prototype using the cover material according to the present invention, and Table 2 shows the test results of the optical characteristics of each prototype. Tables 1 and 2 also show the composition and optical characteristics of the comparative example. In the test sample, the thickness of the core layer was 4.3 mm,
The thickness of the thin surface layer is 0.35 mm, and the thin surface layer is laminated and integrated on both surfaces of the core layer. The test sample of the comparative example is 5 mm thick.

[0017]

[Table 1]

[0018]

[Table 2]

The following items were found from the above measurement results. (A) The whiteness of Comparative Examples 1 and 2 is significantly lower than that of the test sample. If the whiteness is kept the same by increasing the amount of CaCO ₃ added, the light diffusivity decreases, and the total light transmittance greatly decreases. (B) When the amount of titanium oxide added to the surface layer is changed (increased), the whiteness is improved, but the light diffusion rate and the total light transmittance are reduced. The haze value shows almost the same value. (C) The particle diameter of the acrylic polymer beads of the core layer is 5 to 50.
When changed (increased) between μm, the parallel light transmittance increases, but the light diffusion rate and the total light transmittance decrease.

From the above results, considering the cover material, it is considered that the core layer is formed by laminating a thin surface layer having a thickness of 0.1 to 0.5 mm containing titanium oxide in a range of 0.02 to 0.09 parts. Then, it was found that satisfactory whiteness was obtained and that the total light transmittance did not decrease. When the particle size of the acrylic polymer beads becomes 50 μm, the light diffusivity decreases and the haze value decreases. Therefore, it was found that the particle size should be 50 μm or less, preferably 20 μm or less. Such covering materials can be used for lighting fixtures such as general homes and commercial homes,
It is used as a cover material for an illuminated signboard of a type in which a substrate is illuminated with light from a light source such as a fluorescent lamp. It should be noted that, in addition to the illuminated signboard installed outdoors, as well as the lighting equipment installed indoors, if an acrylic protective film is laminated and integrated on the surface of the cover material, the weather resistance is improved without lowering the total light transmittance. be able to.

[0021]

According to the present invention, the total light transmittance of the cover material is not significantly impaired by the thin surface layer. And
The whiteness can be kept high by the surface thin layer. Also,
With the core layer, both the total light transmittance and the haze value can be increased, so that the light source built into the lighting fixture can be made hard to see without lowering the illuminance in the room, and it can be seen in white It is possible to provide a cover material to be used. In addition, when the cover material of the present invention is used for an electric signboard, it is possible to obtain a substrate that exhibits sufficiently satisfactory illuminance and is hard to see the real image of the internal light source in white.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a cover member according to an embodiment of the present invention.

[Explanation of symbols]

 A cover material 1 core layer 2 base layer 3 beads 4 surface thin layer 5 white powder

Claims (1)

(57) [Claims] 1. A core layer in which transparent beads having a refractive index different from that of a bait layer and having a particle diameter of 5 to 50 μm are scattered on a base layer made of a transparent synthetic resin, and a titanium oxide laminated and integrated on the core layer. And a thin layer of a transparent synthetic resin having a thickness of 0.1 to 0.5 mm obtained by distributing 0.02 to 0.09 parts of a white powder such as a transparent powder.