JPH1044285A - Light diffusible resin laminated plate for illumination equipment cover and the illumination equipment cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light diffusion plate for an illumination equipment cover which has all crack retardance and satisfactory light diffusibility as an illumination cover while incorporating feel of a vitreous material therein. SOLUTION: The light diffusible resin laminated plate comprises a structure obtained by laminating a light diffusible resin layer in which light diffusion agent selected from those having weight-average particle size of a range of 0.5 to 20μm is uniformly dispersed in 100 pts.wt. of transparent resin having an entire light ray permeability of 80% or more and a haze of 10 or less so that the total agent becomes 1 to 50 pts.wt. and a transparent resin layer in which an entire light ray permeability of 80% or more and a haze of 10 or less by co-extrusion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin excellent in light diffusivity and surface appearance, which is used for covers of various lighting equipment such as home lighting, facility lighting, store display lighting, and vehicle interior and exterior lighting. The present invention relates to a laminate and a lighting device cover using the laminate.

[0002]

2. Description of the Related Art Conventionally, glass has been widely used as a member provided for a cover of a lighting device. However, since it is easy to form and thereafter is difficult to be broken,
Acrylic resin, styrene resin, polycarbonate,
Transparent resins such as vinyl chloride resins have been used in place of glass.

Further, by using a light diffusing plate in which a light diffusing agent is dispersed in the transparent resin and a molded product obtained by heating and molding the light diffusing plate as an illumination cover, the light of the light source can be more uniformly diffused to prevent glare and to prevent glare. It is widely used for reducing images and for uniform illumination in rooms and the like. However, these light diffusing plates and their molded bodies have mainly focused on diffusing light. Recently, however, the cover of this lighting device has effectively utilized light, and has an elegant appearance. It is desired to have a favorable texture when turned off. That is, there has been a demand for a resin light diffusion plate having a new texture.

To meet these demands, a prism sheet having a prism-shaped sheet surface and a mat sheet having fine irregularities formed on the sheet surface have been provided. The one that combines the diffusivity has not been realized yet.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above situation. That is, an object of the present invention is to provide a light diffusing plate which has a glass-like texture, is hard to break, and has good light diffusing properties as a lighting cover, and still another object is to provide a light diffusing plate even after heat molding. An object of the present invention is to provide a lighting device cover having a beautiful glass texture.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a novel light-diffusing resin laminate for a lighting equipment cover and a lighting equipment cover made of the molded product, and has a total light transmittance of 80% or more and a haze of 10 or less. A light-diffusing resin in which 100 parts by weight of a transparent resin is uniformly dispersed with a light-diffusing agent selected from those having a weight-average particle diameter in the range of 0.5 to 20 μm in a total amount of 1 to 50 parts by weight. Layer (A) and total light transmittance 8
An object of the present invention is to provide a light diffusing resin laminate having a structure in which a transparent resin layer (B) having a haze of 10% or less and a haze of 10% or more is laminated by co-extrusion, and a lighting device cover comprising a molded product thereof.

Hereinafter, the present invention will be described in detail. Specific examples of the transparent resin having a total light transmittance of 80% or more and a haze of 10 or less include methacrylic resin, styrene resin, olefin resin, vinyl chloride resin, polycarbonate, and polyester resin. Among them, a methacrylic resin having a total light transmittance of 92% or more and a haze of 1 or less is most preferable.

The methacrylic resin used in the present invention includes a resin mainly composed of methyl methacrylate.
This includes a homopolymer of methyl methacrylate or methyl methacrylate and methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, butyl acrylate, acrylonitrile, acrylic acid, methacrylic acid, 2-hydroxy acrylate,
It includes a copolymer with any one or more copolymerizable monomers such as maleic anhydride, styrene, and α-methylstyrene, and an impact-resistant acrylic resin.
These may be used alone or may be blended. The rubber elastic body of the impact-resistant acrylic resin is disclosed in
No. 8554, No. 55-94917, No. 61-
Although it is disclosed in, for example, Japanese Patent No. 32346, it is a multi-stage polymer produced by a multi-stage sequential polymerization method in which an elastic layer and an inelastic layer are alternately formed around an acrylic polymer core material. This is blended with an acrylic resin.

The transparent resin of the present invention contains other components such as a pigment, a dye, an antistatic agent, a release agent, a heat stabilizer, an antioxidant, a light stabilizer, and the like, as long as the physical properties are not impaired. An ultraviolet absorber, a plasticizer and the like can be contained. The light diffusing agent used in the present invention corresponds to a known inorganic or organic light diffusing agent. Specific examples of the inorganic diffusing agent include calcium carbonate, barium sulfate, silica, and magnesia. Specific examples of the organic diffusing agent include, for example, a crosslinked styrene polymer, a crosslinked acrylic polymer, a crosslinked siloxane type. The polymer is raised.

[0010] These light diffusing agents have a weight average particle diameter of 0.1.
If the particle size is too small, secondary aggregation occurs between the particles. If the particle size is too large, the surface state of the resin is deteriorated. is required. By blending it with a transparent resin, it is possible to use at least one of calcium carbonate and barium sulfate, which are excellent in light diffusion performance and easy to obtain a high whiteness color tone. preferable.

The amount of addition is determined according to the optical and color characteristics required for the illumination cover member, but is preferably in the range of 1 to 50 parts by weight with respect to 100 parts by weight of the transparent resin. The thickness of the light-diffusing resin layer (A) is not particularly limited, and a thickness in the range of 0.1 to 3 mm, which is easy to secure light-diffusing characteristics as a lighting equipment cover, is appropriate. This patent is not restricted.

The transparent resin layer (B) preferably has a thickness of 0.5 to 5 mm. If the thickness is less than 0.5 mm, the texture of the glass cannot be maintained. If the thickness exceeds 5 mm, the weight of the lighting device cover increases, and the presence of the diffusion layer is weakened especially when the light is turned off. More preferably, it has a sufficient glass texture and does not become excessively heavy as a lighting cover.
The range of m is particularly preferred.

In order to form the light diffusing resin layer (A) and the transparent resin layer (B) into a laminated structure, a plurality of extruders are used to extrude and simultaneously form a laminated plate. It is necessary to. In the coextrusion method, the light-diffusing resin layer (A) and the transparent resin layer (B) are simultaneously formed into a laminated structure at the time of extrusion molding. It can be selected, can be changed continuously, and can be applied to various types.

The transparent resin layer of the light diffusing resin laminate prepared as described above preferably has an arithmetic average roughness (R _a ) of the surface of 0.1 μm or less. 0.1
If it exceeds μm, the unevenness of the surface is visually recognizable, which is not preferable in obtaining a beautiful glass-like appearance. At the same time, the light is scattered on the surface and the illumination effect is reduced. In order to obtain a beautiful glass-like appearance, the thickness is more preferably 0.05 μm or less.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to examples and comparative examples. The evaluation and test methods used in each of the examples and comparative examples are as follows. (1) Measurement of total light transmittance and scattered light transmittance: JIS-
Model 10 manufactured by Nippon Denshoku Industries Co., Ltd. according to K7105
Measure using 01DP. (2) Measurement of arithmetic average roughness (R _a ): JIS-B060
The arithmetic average roughness (R _a ) of the surface of the test piece is measured using a Surfcom 575A type surface roughness meter manufactured by Tokyo Seimitsu Co., Ltd. according to 1. (3) Appearance: The surface of the sheet or its molded product was visually observed from the side of the transparent resin layer, and evaluated as good when it exhibited vitreous gloss and a deep appearance, and evaluated as poor when it was not. did.

[0016]

Example 1 Del Powder 70H as methacrylic resin
(# 99141 transparent powder / Asahi Kasei Kogyo Co., Ltd. product)
100 parts by weight, and 3.5 μm in weight average particle diameter as a light diffusing agent.
22 parts of barium sulfate and 0.25 parts of titanium oxide as a white pigment were blended with a Henschel mixer, and then pelletized at a resin temperature of 260 ° C. with a 40 mmφ extruder equipped with a vent to prepare a light-diffusing resin layer raw material composition. Get.

Two extruders (90 mmφ with vent and L
/ D is 32 single-screw extruder, and 50 mmφ single-screw extruder with L / D is 32) using a unit consisting of three feed blocks, a die, and three polishing rolls. Delpet LP-
1 (# 99141 transparent pellet / product of Asahi Kasei Kogyo Co., Ltd.), co-extruded sheet molding was performed by extruding the raw material composition of the light diffusing resin layer from a 50 mmφ extruder, and a width of 95
A 0 mm laminated sheet is obtained.

The total thickness of the laminated sheet is adjusted to a target of 3.0 mm by the clearance of a polishing roll. The thickness of each layer is adjusted to the transparent methacrylic resin layer 2.8 mm and the light-diffusing resin layer 0.2 mm by adjusting the discharge amount balance of the two extruders. Using this as a test piece, the above (1)
(3) is evaluated.

[0019]

Example 2 An illumination cover is formed by thermoforming the laminated sheet obtained in Example 1 so that the light diffusing resin layer is positioned on the light source side. The sheet temperature is heated to 150 ° C., and vacuum forming is performed according to a conventional method while clamping the periphery.
Thus, a dome-shaped illumination cover having a diameter of 550 mm and a height of 180 mm is obtained. At this time, the length of the corner portion where the laminated sheet is most elongated is doubled.

After observing the external appearance, the above-mentioned evaluation (3) is performed on a test piece cut from the corner.

[0021]

Example 3 100 parts by weight of the above-mentioned Del Powder 70H,
As a light diffusing agent, 0.95 part of barium sulfate having a weight average particle diameter of 3.5 μm and 0.8 part of calcium carbonate having a weight average particle diameter of 5 μm were pelletized in the same manner as in Example 1, and further, similarly as in Example 1. 2m clear methacrylic resin layer by extrusion
m, a laminated sheet having a light diffusing resin layer of 2 mm.

Using the obtained laminated sheet as a test piece, the above evaluations (1) to (3) are performed.

[0023]

Example 4 The laminated sheet obtained in Example 3 was replaced with Example 2
Thermoforming is performed in the same manner as described above, and the same evaluation is performed.

[0024]

Comparative Example 1 A single-layer sheet was prepared using only the same light-diffusing resin layer raw material composition as in Example 3 without providing a transparent resin layer. Appearance is glassy gloss, texture does not look deep,
It is a milky translucent plate.

[0025]

COMPARATIVE EXAMPLE 2 When the sheet of Comparative Example 1 was thermoformed in the same manner as in Example 2, as a result, the surface roughness was larger than that of the original sheet, and the gloss was further reduced.

[0026]

Comparative Example 3 A laminated sheet was obtained in the same manner as in Example 3 except that the thickness of the transparent resin layer was changed to 0.2 mm. The appearance is the same as that of a translucent translucent plate, without vitreous luster or deep texture. Table 1 summarizes the above results.

[0027]

[Table 1]

[0028]

The light-diffusing resin laminate for lighting equipment cover obtained by the present invention has a favorable glass-like appearance and an excellent lighting effect by improving the surface appearance. It is extremely useful for application to Moreover, the lighting device cover, which is a molded article, has excellent lighting effects and is extremely useful as a cover for lighting devices.

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Claims (5)

[Claims] 1. A light diffusing agent selected from those having a weight average particle size in the range of 0.5 to 20 μm is added to 100 parts by weight of a transparent resin having a total light transmittance of 80% or more and a haze of 10 or less. A light-diffusing resin layer (A) uniformly dispersed so as to be 1 to 50 parts by weight in total and a transparent resin layer (B) having a total light transmittance of 80% or more and a haze of 10 or less are laminated by co-extrusion. Light-diffusing resin laminate for lighting equipment covers with a structured structure. 2. The light diffusing resin for a lighting equipment cover according to claim 1, wherein the arithmetic mean roughness (R _a ) of the surface of the transparent resin layer (B) is 0.1 μm or less. Laminated board. 3. The light diffusing resin laminate for lighting equipment covers according to claim 1, wherein the transparent resin is a methacrylic resin. 4. The light diffusing resin laminate for lighting equipment covers according to claim 1, wherein at least one of the light diffusing agents is selected from calcium carbonate and barium sulfate. 5. A lighting equipment cover formed by heating and molding the light diffusing resin laminate according to claim 1.