JP6846682B2 - Optical components, lighting covers and lighting fixtures - Google Patents

Description

The present invention relates to optical members, luminaire covers and luminaires. More specifically, the present invention relates to an optical member having excellent light transmission and light diffusivity, and a lighting cover and a luminaire using the light diffusing member.

The luminaire generally includes a luminaire cover that covers the light source unit. The illumination cover is usually formed by using an optical member having light transmission and light diffusivity. By using such a light-transmitting and light-diffusing lighting cover, it is possible to diffuse the light emitted from the light source over the entire surface of the light-transmitting surface of the lighting cover. As a result, the amount of light transmitted per unit area on the entire surface of the translucent surface can be made uniform, and uneven light and darkness can be suppressed on the transmissive surface. Further, by making the amount of light transmitted per unit area uniform, it is possible to conceal the image of the light source and enhance the dignity of the luminaire.

Generally, an optical member having light transmission and light diffusivity is manufactured by molding a resin sheet containing a white pigment. As the white pigment, white inorganic pigments such as silicon oxide, barium sulfate, calcium carbonate, titanium oxide, mica, magnesium oxide, talc, aluminum hydroxide, and aluminum oxide are used. Then, by increasing the amount of the white pigment added, it is possible to impart excellent light diffusivity to the optical member. However, although these pigments have the effect of diffusing light, there is a problem that the light transmittance decreases in proportion to the amount of addition. Therefore, when trying to obtain an optical member having excellent light diffusivity, there is a problem that the light transmittance is lowered. Further, since the inorganic particles used as the white pigment deteriorate the surface of the optical member, there is a possibility that chalking may occur on the surface of the optical member.

Therefore, for example, Patent Document 1 proposes to use a light-diffusing coating composition containing an acrylic resin, a fluororesin, and light-diffusing particles as a light-diffusing member. The light diffusing coating composition of Patent Document 1 contains 0.3 to 20 parts by mass of fluororesin with respect to 100 parts by mass of acrylic resin, and 0. It is contained in an amount of 3 to 20 parts by mass.

Japanese Unexamined Patent Publication No. 2012-208424

However, light emitting diode (LED) luminaires, which have been attracting attention in recent years from the viewpoint of energy saving, need to efficiently extract light with low power consumption, and therefore, an optical member having higher light transmission is desired. On the other hand, since the LED light source has a strong directivity, it is necessary to impart light diffusivity to the optical member and make it difficult to recognize that the light source of the LED illumination is a point light source.

The present invention has been made in view of such a situation, and an object of the present invention is to provide an optical member having excellent light transmission and light diffusivity, and a lighting cover and a lighting fixture using the same.

In order to solve the above problems, the optical member according to the first aspect of the present invention comprises a translucent resin base material, a translucent resin containing a fluororesin, and polytetrafluoroethylene-based resin particles. It has a light diffusing layer including. The light diffusion layer contains 100 to 250 parts by mass of polytetrafluoroethylene-based resin particles with respect to 100 parts by mass of the resin. The light diffusion layer is provided on one surface of the resin base material.

The lighting cover according to the second aspect of the present invention uses the optical member according to the first aspect.

The luminaire according to the third aspect of the present invention includes a luminaire body having an opening, a light source provided in the luminaire body, and a lighting cover in the second aspect covering the opening.

According to the present invention, it is possible to provide an optical member having excellent light transmission and light diffusivity, and a lighting cover and a lighting fixture using the optical member.

It is sectional drawing which shows an example of the optical member which concerns on this embodiment. It is a schematic diagram which shows the behavior of light on the surface of the light diffusion layer of this embodiment. It is the schematic which shows the behavior of light on the surface of the polytetrafluoroethylene resin particle of this embodiment. It is sectional drawing which shows an example of the lighting cover and the lighting fixture which concerns on this embodiment.

Hereinafter, the optical member according to the present embodiment, and the lighting cover and the luminaire using the optical member will be described in detail.

[Optical member]
FIG. 1 shows an example of an optical member according to the present embodiment. The optical member 11 according to the present embodiment includes a light-transmitting resin base material 12, a light-transmitting resin 13 containing a fluororesin, and a light diffusion layer 15 containing polytetrafluoroethylene-based resin particles 14. Have. The light diffusion layer 15 contains 100 to 250 parts by mass of the polytetrafluoroethylene-based resin particles 14 with respect to 100 parts by mass of the resin 13. The light diffusion layer 15 is provided on one surface of the resin base material 12.

The optical member 11 according to the present embodiment has a translucent resin base material 12 and a light diffusing layer 15. The light diffusion layer 15 is provided on one surface of the resin base material 12. Specifically, as will be described later, for example, when the optical member 11 is used as the lighting fixture 100, the light diffusing layer 15 is set on the resin base material so that the light diffusing layer 15 is on the light source side with respect to the resin base material 12. It can be provided on one side of the twelve.

The light-transmitting resin base material 12 is not particularly limited as long as it is a light-transmitting resin, but a resin having a total light transmittance of 90% or more is preferable. The total light transmittance can be determined by using, for example, a haze meter (NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd.), Japanese Industrial Standard JIS K7361-1 (Plastic-Transparent Material Total Light Transmittance Test Method-First). Part: Can be measured by the single beam method).

As the resin base material 12, for example, one formed of at least one selected from the group consisting of acrylic resin, polyester resin, polycarbonate resin and styrene resin can be used. Among them, acrylic resin and polycarbonate resin have high light transmission. Therefore, it is preferable that the resin base material 12 is formed of at least one of an acrylic resin and a polycarbonate resin.

Acrylic resin is a resin obtained by polymerizing a monomer containing at least one of acrylate and methacrylate. Examples of the acrylate include a group consisting of methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, isobornyl acrylate, glycidyl acrylate, benzyl acrylate, stearyl acrylate, lauryl acrylate, and 2-hydroxy-3-phenoxypropyl acrylate. At least one of the more selected can be mentioned. Examples of the methacrylate include methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, isobornyl methacrylate, glycidyl methacrylate, benzyl methacrylate, stearyl methacrylate, lauryl methacrylate, and 2-hydroxy-3-phenoxypropyl methacrylate. At least one of the more selected can be mentioned.

The acrylic resin may be a copolymer of a monomer containing at least one of acrylate and methacrylate and a monomer having a carbon-carbon double bond. Examples of the monomer having a carbon-carbon double bond include at least one selected from the group consisting of styrene-based monomers, olefin-based monomers, and vinyl-based monomers. Examples of the styrene-based monomer include styrene and the like. Examples of the olefin-based monomer include ethylene and propylene. Examples of the vinyl-based monomer include vinyl chloride and vinylidene chloride. The above-mentioned monomer components may be used alone or in combination of two or more.

Polycarbonate resin is a polymer having a carbonate bond in the main chain. As the polycarbonate resin, a polymer obtained by reacting bisphenol with phosgene, bisphenol with diphenyl carbonate, or the like can be used.

As the resin base material 12, either a thermoplastic resin or a thermosetting resin may be used. When processing after obtaining the optical member 11 according to the present embodiment, the resin base material 12 is preferably a thermoplastic resin because it can be stretch-molded to fit a predetermined shape.

The thickness of the resin base material 12 is not particularly limited, but is preferably 0.1 mm to 3 mm, for example. Considering moldability and strength, the thickness of the resin base material 12 is more preferably 1 mm to 2 mm. As the resin base material 12, those obtained by a sheet molding method such as a glass casting method, a continuous casting method, or an extrusion method can be used.

The light diffusion layer 15 contains a translucent resin 13 containing a fluororesin and polytetrafluoroethylene-based resin particles 14. When the refractive index of the light diffusing layer is high, when the light emitted from the light source is incident on the light diffusing layer, the difference in refractive index between the air layer on the light source side and the light diffusing layer becomes large, so that Frenel reflection is likely to occur. .. However, in the present embodiment, since the translucent resin 13 containing the fluororesin having a small refractive index and the polytetrafluoroethylene-based resin particles 14 are used for the light diffusing layer 15, the air layer and the light diffusing layer are used. The difference in refractive index from 15 becomes smaller. As a result, as shown in FIG. 2, the amount of Fresnel-reflected light F1 decreases and the amount of refracted light R1 increases, so that the light transmission of the light diffusion layer 15 increases. Further, in the light diffusion layer 15 according to the present embodiment, both the resin 13 and the polytetrafluoroethylene-based resin particles 14 are fluorine-based resins. Therefore, even when the light diffusion layer 15 does not contain a dispersant, the compatibility between the resin 13 and the polytetrafluoroethylene-based resin particles 14 is good. Therefore, in the present embodiment, the presence or absence of the dispersant is not limited, and the dispersant can be blended in the light diffusion layer 15 as long as the optical characteristics of the present embodiment are not affected. That is, the light diffusion layer 15 may not contain a dispersant depending on the optical characteristics of the optical member 11.

The light diffusion layer 15 contains 100 to 250 parts by mass of the polytetrafluoroethylene-based resin particles 14 with respect to 100 parts by mass of the resin 13. When the content of the polytetrafluoroethylene-based resin particles 14 is 100 parts by mass or more, the light diffusing effect due to the difference in refractive index between the resin 13 and the polytetrafluoroethylene-based resin particles 14 is improved, so that the light diffusivity is improved. An excellent optical member 11 can be obtained. When the content of the resin 13 is 100 parts by mass or more, the polytetrafluoroethylene-based resin particles 14 are appropriately exposed on the surface of the light diffusion layer 15. The exposure of the polytetrafluoroethylene-based resin particles 14 forms a hemispherical lens-shaped convex portion as shown in FIG. Due to this convex portion, not only the refracted light R2 that has directly entered the light diffusing layer from the air layer, but also the light F2 that is reflected by Frenel at the interface between the gas layer and the light diffusing layer 15 is formed as the refracted light R3 in the adjacent convex portion. As it enters, the light capture effect is improved. That is, since the light capture effect is improved, the light transmission is improved. Further, when the content of the polytetrafluoroethylene resin particles 14 is 250 parts by mass or less, it is possible to obtain an optical member 11 having less aggregation of the polytetrafluoroethylene resin particles 14 and excellent light transmission. .. That is, when the content of the polytetrafluoroethylene-based resin particles 14 is in the above range, the light diffusion layer 15 having both light transmission and light diffusivity is formed.

The thickness of the light diffusion layer 15 is not particularly limited, but is preferably 5 μm or more and 20 μm or less. When the thickness of the light diffusing layer 15 is 5 μm or more, the light diffusing layer 15 can exert a higher light diffusing effect. Further, when the thickness of the light diffusion layer 15 is 20 μm or less, convex portions derived from the polytetrafluoroethylene resin particles 14 are likely to be formed on the surface of the light diffusion layer 15. Due to the convex portion of the surface, the light uptake effect as described above is improved, and the light diffusion layer 15 having high light transmission can be obtained. Further, the thickness of the light diffusion layer 15 is more preferably 7 μm or more and 15 μm or less. When the thickness of the light diffusing layer 15 is in such a range, an optical member 11 having higher light transmissivity and light diffusing property can be obtained. From the viewpoint of forming a convex portion on the surface of the light diffusion layer 15, the thickness of the light diffusion layer 15 is preferably adjusted in consideration of the average particle size of the polytetrafluoroethylene resin particles 14.

The light diffusion layer 15 can be formed, for example, by applying a coating composition containing the resin 13 and the polytetrafluoroethylene-based resin particles 14 to the resin base material 12. The coating method of the coating composition is not particularly limited, but a spray coating method, a dip coating method, a flow coating method, a spin coating method, a roll coating method, a brush coating method, a sponge coating method, or the like is preferably used. can do. When the coating composition contains an organic solvent, the light diffusion layer 15 can be formed on the surface of the resin base material 12 by removing the organic solvent by heating or the like.

The translucent resin 13 containing a fluororesin is not particularly limited as long as it has light transmittance and contains fluorine, but a resin having a total light transmittance of 90% or more is preferable. The total light transmittance can be measured by JIS K7361-1 using, for example, a haze meter or the like.

The resin 13 is not particularly limited as long as it contains fluorine. The fluororesin is a resin obtained by polymerizing a monomer containing at least fluorine. Examples of the fluorine-containing monomer include at least one selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, vinylidene fluoride, vinyl fluoride, fluorovinyl ether and hexafluoropropylene.

The fluororesin may be a copolymer of a monomer containing fluorine and a monomer having a carbon-carbon double bond. Examples of the monomer having a carbon-carbon double bond include at least one selected from the group consisting of a styrene-based monomer, an olefin-based monomer, a vinyl-based monomer, and an acrylic-based monomer. Examples of the styrene-based monomer include styrene. Examples of the olefin-based monomer include ethylene and propylene. Examples of the vinyl-based monomer include vinyl chloride and vinylidene chloride. Examples of the acrylic monomer include acrylate and methacrylate. The above-mentioned monomer components may be used alone or in combination of two or more.

The resin 13 includes, for example, a polytetrafluoroethylene (PTFE) -based resin, a polychlorotrifluoroethylene (PCTFE) -based resin, a polyvinylidene fluoride (PVDF) -based resin, a polyvinyl fluoride (PVF) -based resin, and tetrafluoroethylene. Perfluoroalkyl vinyl ether (PFA) -based copolymer, tetrafluoroethylene / hexafluoropropylene (FEP) -based copolymer, ethylene / tetrafluoroethylene (ETFE) -based copolymer and ethylene / chlorotrifluoroethylene (ECTFE) -based At least one selected from the group consisting of copolymers may be contained.

The refractive index of the resin 13 is not particularly limited, but is preferably 1.32 or more and 1.42 or less. When the refractive index of the resin 13 is in such a range, the light transmittance of the light diffusion layer 15 can be increased. Further, from the viewpoint of increasing the light transmittance, the refractive index of the resin 13 is preferably 1.32 or more and 1.39 or less. The refractive index is a value on the NaD line (589 nm) measured by an Abbe refractometer.

The polytetrafluoroethylene-based resin particles 14 form convex portions on the surface of the light diffusing layer 15 and diffuse the light incident on the light diffusing layer 15. The polytetrafluoroethylene-based resin particles 14 are particles containing the polytetrafluoroethylene-based resin. The polytetrafluoroethylene-based resin may be polytetrafluoroethylene, which is a homopolymer of tetrafluoroethylene monomers. Further, the polytetrafluoroethylene resin may be a copolymer with a polytetrafluoroethylene monomer containing a monomer other than tetrafluoroethylene up to about 30 mol%. Examples of monomers other than tetrafluoroethylene include fluorine-containing monomers such as chlorotrifluoroethylene, vinylidene fluoride, vinyl fluoride, fluorovinyl ether, and hexafluoropropylene, and non-fluorine such as ethylene, propylene, and acrylic acid. At least one selected from the group consisting of containing monomers can be used. The polytetrafluoroethylene resin may be modified or unmodified depending on the intended use.

Although not particularly limited, the average particle size (D50) of the polytetrafluoroethylene-based resin particles 14 is preferably 1 μm or more and 20 μm or less. When the average particle size of the polytetrafluoroethylene-based resin particles 14 is 1 μm or more, light easily collides with the polytetrafluoroethylene-based resin particles 14, so that the light diffusivity can be improved. When the average particle size of the polytetrafluoroethylene-based resin particles 14 is 1 μm or more, a sufficient proportion of convex portions can be formed on the surface of the light diffusion layer 15. The convex portion improves the light capture effect of the light diffusion layer 15 as described above, so that the light transmission of the optical member 11 is improved. Further, since the average particle size of the polytetrafluoroethylene resin particles 14 is 20 μm or less, the dispersibility of the polytetrafluoroethylene resin particles 14 in the light diffusion layer 15 is improved, so that the light of the optical member 11 is improved. The transparency can be increased. Further, the average particle size of the polytetrafluoroethylene resin particles 14 is more preferably 2 μm or more. In such a range, the light transmittance and the light diffusivity of the optical member 11 are further increased. Further, the average particle size of the polytetrafluoroethylene resin particles 14 is more preferably 10 μm or less. In such a range, the light transmittance of the optical member 11 becomes higher. The average particle size (D50) of the polytetrafluoroethylene resin particles 14 can be determined by a laser diffraction / scattering method using a laser diffraction type particle size distribution measuring device.

The optical member 11 according to the present embodiment includes a light-transmitting resin base material 12, a light-transmitting resin 13 containing a fluororesin, and a light diffusion layer 15 containing polytetrafluoroethylene-based resin particles 14. Have. The light diffusion layer 15 contains 100 to 250 parts by mass of the polytetrafluoroethylene-based resin particles 14 with respect to 100 parts by mass of the resin 13. The light diffusion layer 15 is provided on one surface of the resin base material 12. Therefore, it is possible to obtain an optical member 11 having high light transmission and light diffusivity.

[Lighting cover]
Next, the lighting cover 40 of this embodiment will be described. The illumination cover 40 of this embodiment uses an optical member 11. That is, the illumination cover 40 of this embodiment includes an optical member 11.

The shape of the lighting cover 40 is not particularly limited, but for example, it is preferably mounted so as to cover the lamp as the light source 30. At this time, the lamp may be mounted so as to cover the entire light emitting portion of the lamp, or may be mounted so as to cover a part of the light emitting portion of the lamp. The illumination cover 40 may have a flat plate shape, but it can also be molded by pressing and stretching in order to form a shape that covers the lamp.

Such a lighting cover 40 can be used for various lighting fixtures. For example, it can be suitably used for a ceiling light, a pendant type light, a sink light, a bathroom light, a chandelier, a stand, a bracket, a cover for a lantern, and the like. Also, for garage lights, eaves lights, gatepost lights, porch lights, garden lights, entrance lights, foot lights, stairs lights, guide lights, security lights, downlights, base lights, illuminated signs, sign lights, etc. It can be preferably used. Further, it can be suitably used as a cover for vehicle lighting equipment such as automobiles and motorcycles. In particular, as will be described later, it can be suitably used for a ceiling light or the like having a structure in which the lighting cover 40 is sandwiched between the fixture main body 20.

As described above, the lighting cover 40 according to the present embodiment uses the optical member 11. Therefore, it is possible to obtain an illumination cover 40 having high light transmission and light diffusivity.

[lighting equipment]
Next, the lighting fixture 100 of the present embodiment will be described. The lighting fixture 100 of the present embodiment includes a fixture main body 20 having an opening 21, a light source 30 provided in the fixture main body 20, and a lighting cover 40 covering the opening 21.

The lighting fixture 100 according to the present embodiment includes a fixture main body 20, a light source 30, and a lighting cover 40. FIG. 4 shows an example of the lighting fixture 100. The luminaire 100 is a circular ceiling type light. Although the circular ceiling type light is described in FIG. 4, the luminaire 100 may be a polygonal ceiling type light.

The instrument body 20 includes, for example, a base portion 22, an engaged portion 23, and a support portion 24. The base portion 22 can be installed on an installation surface such as a ceiling 50 depending on the application. The engaged portion 23 engages with the engaging portion 41 of the lighting cover 40. In the form of FIG. 4, the engaged portion 23 is formed so as to project toward the outside of the instrument body. The support portion 24 supports the lighting cover 40 from the outside so that the lighting cover 40 does not shift or rattle. The support portion 24 is formed so as to project downward from the outside of the instrument main body 20 with respect to the engaged portion 23. The engaged portion 23 and the support portion 24 may be provided over the entire circumference of the instrument main body 20 or may be provided partially. The fixture body 20 can be installed on the ceiling 50 as shown in FIG. 4, or can be installed at an installation location according to the application such as the above-mentioned lantern.

The instrument body 20 has an opening 21. The shape and size of the opening 21 are not particularly limited, and the opening 21 can be covered with the illumination cover 40. As shown in FIG. 4, the opening 21 can be provided on the side opposite to the installation surface of the base portion 22. The opening 21 may be formed so as to be surrounded by the support portion 24 as shown in FIG.

The light source 30 is provided on the instrument body 20. The light source 30 can also be provided inside the opening 21 of the instrument body 20. The light source used for the light source 30 is not particularly limited, such as a point light source, a line light source, and a surface light source. The light source used for the light source 30 is not particularly limited, but a light emitting diode (LED) light source, a fluorescent lamp, an incandescent lamp, a high-intensity discharge lamp (HID), or the like can be used. The instrument main body 20 according to the present embodiment has high light transmission and light diffusivity, and is preferable because it can contribute to energy saving when used as an LED light source. A single light source can be used as the light source 30, or a plurality of light sources can be used as the light source 30.

At the upper end of the lighting cover 40, an engaging portion 41 for hooking on the fixture main body 20 can be provided. In the illustrated form, the engaging portion 41 is formed so as to project toward the inside of the instrument main body 20. The engaging portion 41 may be provided over the entire circumference of the illumination cover 40, or may be provided in a part thereof.

The lighting cover 40 covers the opening 21. For example, as shown in FIG. 4, the illumination cover 40 having a substantially C-shaped cross section can be attached to the fixture main body 20 from below so as to cover the light source 30. At this time, it is preferable that the light diffusion layer 15 is arranged closer to the light source 30 than the resin base material 12. By doing so, the luminaire 100 having high light transmission can be obtained by the convex portion on the surface of the light diffusion layer 15.

As described above, the lighting fixture 100 according to the present embodiment has the fixture main body 20 having the opening 21, the light source 30 provided in the fixture main body 20, and the lighting cover 40 covering the opening 21. Therefore, for example, even when a light source having high directivity such as an LED light source is used, it is possible to provide the luminaire 100 having high light transmission and light diffusivity.

Hereinafter, the present embodiment will be described in more detail with reference to Examples and Comparative Examples, but the present embodiment is not limited to these Examples.

[Example 1]
150 parts by mass of polytetrafluoroethylene-based resin particles were added to 100 parts by mass of the solid content of the translucent resin containing the fluororesin. As a translucent resin containing a fluororesin, PES-5 manufactured by Kanto Denka Kogyo Co., Ltd. was used. PES-5 contains a monomer containing a fluorine atom, and PES-5 has a refractive index of 1.39. Further, as the polytetrafluoroethylene resin particles, KTL-10S manufactured by Kitamura Co., Ltd. was used. The refractive index of KTL-10S is 1.35, and the average particle size is 10 μm.

Further, a solution was prepared in which the solid content was diluted with propylene glycol monomethyl ether acetate so that the total solid content was 25% by mass. The diluted solution was ultrasonically stirred until the solids were evenly dispersed to give the paint.

This paint is applied to the surface of a translucent resin base material with a bar coater so that the film thickness is 10 μm, and the solvent is dried at 80 ° C. for 10 minutes to diffuse light onto the surface of the resin base material. An optical member having a layer formed was obtained. As the resin base material, an acrylic plate measuring 100 mm square and having a thickness of 2 mm was used. As this acrylic plate, Sumipex (registered trademark) E000 manufactured by Sumitomo Chemical Co., Ltd. was used. The haze of this acrylic plate is 0.2% and the total light transmittance is 92.5%.

[Example 2]
An optical member was prepared in the same procedure as in Example 1 except that 100 parts by mass of polytetrafluoroethylene resin particles were added to 100 parts by mass of the solid content of the translucent resin containing a fluororesin.

[Example 3]
An optical member was prepared in the same procedure as in Example 1 except that 233 parts by mass of polytetrafluoroethylene resin particles were added to 100 parts by mass of the solid content of the translucent resin containing a fluororesin.

[Example 4]
Instead of PES-5 used in Example 1, the optical member was prepared in the same procedure as in Example 1 except that the developed product N3818 manufactured by Kanto Denka Kogyo Co., Ltd. was used as a translucent resin containing a fluororesin. Created. N3818 contains a monomer containing a fluorine atom, and N3818 has a refractive index of 1.42 and an average particle size of 10 μm.

[Example 5]
An optical member was prepared in the same procedure as in Example 1 except that KTL-9S manufactured by Kitamura Co., Ltd. was used as the polytetrafluoroethylene resin particles instead of KTL-10S used in Example 1. The refractive index of KTL-9S is 1.35, and the average particle size is 9 μm.

[Example 6]
Same as Example 1 except that 3M® Dyneon® PTFE micropowder TF9205 manufactured by 3M Company was used as polytetrafluoroethylene resin particles in place of KTL-10S used in Example 1. An optical member was created by the procedure. The refractive index of 3M (registered trademark) Dyneon (registered trademark) PTFE micropowder TF9205 is 1.35, and the average particle size is 8 μm.

[Example 7]
An optical member was prepared in the same procedure as in Example 1 except that SST-3 manufactured by SHAMROCK was used as the polytetrafluoroethylene-based resin particles instead of KTL-10S used in Example 1. The refractive index of SST-3 is 1.35, and the average particle size is 5 μm.

[Example 8]
An optical member was prepared in the same procedure as in Example 1 except that CERAFLOUR (registered trademark) 981 manufactured by BYK Chemie was used as the polytetrafluoroethylene resin particles in place of KTL-10S used in Example 1. .. The refractive index of CERAFLOUR (registered trademark) 981 is 1.35, and the average particle size is 3 μm.

[Example 9]
An optical member was prepared in the same procedure as in Example 1 except that KTL-2N manufactured by Kitamura Co., Ltd. was used as the polytetrafluoroethylene resin particles instead of KTL-10S used in Example 1. The refractive index of KTL-2N is 1.35, and the average particle size is 2 μm.

[Comparative Example 1]
An optical member was prepared in the same procedure as in Example 1 except that 67 parts by mass of polytetrafluoroethylene resin particles were added to 100 parts by mass of the solid content of the translucent resin containing a fluororesin.

[Comparative Example 2]
An optical member was prepared in the same procedure as in Example 1 except that 300 parts by mass of polytetrafluoroethylene resin particles were added to 100 parts by mass of the solid content of the translucent resin containing a fluororesin.

[Comparative Example 3]
A lighting cover was prepared in the same procedure as in Example 1 except that Tospearl (registered trademark) 2000B manufactured by Momentive Performance Materials Co., Ltd. was used as silicone particles in place of KTL-10S used in Example 1. The refractive index of Tospearl (registered trademark) 2000B is 1.43, and the average particle size is 6 μm.

[Evaluation]
The following items were evaluated for the optical members obtained in Examples 1 to 9 and Comparative Examples 1 to 3. Table 1 shows the details of each example and the evaluation results.

[Total light transmittance]
Using a haze meter (NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd.), the total light transmittance of the optical members of each example was measured. The total light transmittance was measured according to JIS K7361-1 (Plastic-Test method for total light transmittance of transparent material-Part 1: Single beam method). If the total light transmittance is 90% or more, it can be judged that the light transmittance is excellent. Therefore, the following criteria were used.
・ Judgment criteria 90% or more: ○
Less than 90%: ×

[Haze]
The haze of the optical member of each example was measured using a haze meter (NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd.). The haze was measured according to JIS K7136 (Plastic-How to determine the haze of transparent material). If the haze is 80% or more, it can be judged that the light diffusivity is excellent. Therefore, the following criteria were used.
・ Judgment criteria 80% or more: ○
Less than 80%: ×

In Examples 1 to 9, since 100 to 250 parts by mass of polytetrafluoroethylene resin particles are contained with respect to the translucent resin containing 100 parts by mass of the fluororesin, the total light transmission amount and the haze are increased. The value met a predetermined criterion. That is, it was confirmed that the optical member has both light transmission and light diffusivity.

On the other hand, the optical member of Comparative Example 1 contains 67 parts by mass of polytetrafluoroethylene-based resin particles with respect to a translucent resin containing 100 parts by mass of a fluororesin. Therefore, although the value of the total light transmittance satisfies a predetermined criterion, the haze value does not satisfy the predetermined criterion. That is, it cannot be said that the optical member of Comparative Example 1 has sufficient light diffusivity. It is probable that the light could not be sufficiently diffused due to the low content of the polytetrafluoroethylene resin particles.

The optical member of Comparative Example 2 contains 300 parts by mass of polytetrafluoroethylene-based resin particles with respect to a translucent resin containing 100 parts by mass of a fluororesin. Therefore, although the haze value satisfies the predetermined criterion, the value of the total light transmittance does not satisfy the predetermined criterion. That is, it cannot be said that the optical member of Comparative Example 2 has sufficient light transmission. It is considered that the total light transmittance decreased because the content of the polytetrafluoroethylene-based resin particles was high and the polytetrafluoroethylene-based resin particles aggregated with each other.

The optical member of Comparative Example 3 contains silicone particles having a refractive index of 1.43 instead of the polytetrafluoroethylene-based resin particles having a refractive index of 1.35. Therefore, although the haze value satisfies the predetermined criterion, the value of the total light transmittance does not satisfy the predetermined criterion. That is, it cannot be said that the optical member of Comparative Example 3 has sufficient light transmission. When particles having a higher refractive index than polytetrafluoroethylene are used, it is considered that the total light transmittance is lowered because Fresnel reflection is likely to occur due to the convex portions on the surface of the light diffusion layer derived from the particles.

Further, in Examples 1 and 5-9, the haze value tended to decrease as the average particle size of the polytetrafluoroethylene-based resin particles decreased. It is considered that this is because if the particles are too small, sufficient protrusions are not formed on the surface of the light diffusing layer, and the light diffusing effect is lowered. On the other hand, if the particle size is too large, the particles will aggregate in the light diffusion layer. Generally, since polytetrafluoroethylene-based resin particles are produced by pulverization, the larger the average particle size, the more the shape tends to be distorted. When the shape of the particles is distorted, the amount of light taken in by Fresnel reflection decreases, and as a result, the total light transmittance tends to decrease. Therefore, the average particle size of the polytetrafluoroethylene resin particles is preferably 1 to 20 μm.

Although the contents of the present embodiment have been described above with reference to the examples, it is obvious to those skilled in the art that the present embodiment is not limited to these descriptions and various modifications and improvements are possible. is there.

11 Optical member 12 Resin base material 13 Resin 14 Polytetrafluoroethylene resin particles 15 Light diffusion layer 20 Equipment body 21 Opening 30 Light source 40 Lighting cover 100 Lighting equipment

Claims (5)

With a translucent resin base material,
It is obtained by polymerizing at least one selected from the group consisting of at least tetrafluoroethylene, chlorotrifluoroethylene, vinylidene fluoride, vinyl fluoride, fluorovinyl ether and hexafluoropropylene, which is provided on one surface of the resin base material. A light diffusion layer containing 100 to 250 parts by mass of the polytetrafluoroethylene resin particles with respect to 100 parts by mass of the fluororesin , which contains a translucent fluororesin and polytetrafluoroethylene resin particles.
Optical member having. The optical member according to claim 1, wherein the polytetrafluoroethylene-based resin particles have an average particle size of 1 to 20 μm. A lighting cover using the optical member according to claim 1 or 2. The instrument body with an opening and
The light source provided on the instrument body and
The lighting cover according to claim 3, which covers the opening.
Have a lighting fixture. The lighting fixture according to claim 4, wherein the light diffusion layer is arranged closer to the light source than the resin base material.

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