JP2017052880A - Coating composition, and optical member and lighting cover using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition capable of improving optical transparency and light diffusibility by a simpler configuration and exhibiting antibacterial performance and antiviral performance, and to provide an optical member and a lighting cover using the coating composition.SOLUTION: A coating composition comprises an acrylic resin, light diffusing particles, and cuprous oxide. The light diffusing particles are contained in an amount of 40-120 pts.mass with respect to 100 pts.mass of the solid matter of the acrylic resin. The cuprous oxide is contained in an amount of 0.5-5 pts.mass with respect to 100 pts.mass of the solid matter of the acrylic resin. An optical member includes a transparent resin substrate and a light diffusion layer provided on a surface of the transparent resin substrate opposite to a surface thereof facing a light source portion and including the coating composition. A lighting cover includes the optical member.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a coating composition, an optical member using the same, and a lighting cover. Specifically, the present invention provides a coating composition that has both high light transmittance and light diffusibility, and can exhibit antibacterial performance and antiviral performance, an optical member using the coating composition, and the optical member. It relates to the used lighting cover.

  The luminaire generally includes a lighting cover that covers the light source unit. This lighting cover is usually formed by using an optical member having light permeability and light diffusibility. By using the illumination cover having such light diffusibility, it is possible to diffuse the light emitted from the light source over the entire light-transmitting surface of the illumination cover. As a result, the light transmission amount per unit area on the entire surface of the light transmitting surface can be averaged, and unevenness of brightness and darkness on the light transmitting surface can be suppressed. The lighting cover also conceals the image of the light source and enhances the quality of the lighting fixture.

  In general, an optical member having light transmittance and light diffusibility is manufactured by molding a resin sheet containing a white pigment. As this 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. And the outstanding light diffusibility can be provided with respect to an optical member by increasing the addition amount of a white pigment. However, although these pigments have an effect of diffusing light, there is a problem that light transmittance is reduced in proportion to the amount of addition. For this reason, when an optical member having excellent light diffusibility is to be obtained, there is a problem that the light transmittance is lowered. Further, since the inorganic particles of the white inorganic pigment deteriorate the surface of the optical member, there is a possibility that choking may occur on the surface of the optical member.

  As described above, it is possible to obtain an optical member imparted with excellent light diffusibility even by the conventional method, but the light transmittance is lowered, so that both high light transmittance and light diffusibility are achieved. It was difficult. Therefore, when the optical member obtained by the conventional method is applied to the lighting cover, it is inevitable to sacrifice the brightness of the lighting device in order to suppress the occurrence of uneven brightness on the light-transmitting surface. It was.

  Conventionally, a method of forming a photocatalytic film on a lighting cover of a lighting fixture or the like is known in order to provide a comfortable indoor environment such as deodorization and antibacterial. However, in order to develop deodorant performance and antibacterial performance, it is necessary to contain a considerable amount of photocatalyst particles in the photocatalyst film. Therefore, when such a photocatalytic film is applied to a lighting cover, there is a possibility that the optical characteristics are affected.

  By the way, in recent years, lighting fixtures (LED lighting) using LED light sources have attracted attention. Thus, energy saving of a lighting fixture can be achieved by using LED (light emitting diode) as a light source. And as long as the LED illumination is intended to save energy, the illumination cover for LED illumination is required to have higher light transmittance than the illumination cover for conventional fluorescent lamps. Therefore, in order to apply the lighting cover to LED lighting, it is necessary to improve the light transmittance of the lighting cover. Furthermore, since the LED light source has strong directivity, it is necessary to impart light diffusibility to the illumination cover and make it difficult to recognize that the light source of the LED illumination is a point light source.

  Therefore, conventionally, a light diffusing film for LED illumination having a single substrate, an internal scattering layer containing at least particles and a binder, and a surface shape layer containing at least particles and a binder has been disclosed (for example, Patent Documents). 1). In Patent Document 1, the refractive index difference between the particles and the binder is set to a predetermined value or less, and the average particle diameter of the particles is within a specific range, thereby improving light utilization efficiency while achieving high concealability. ing.

  Conventionally, there has also been proposed a laminate having a visible light photocatalyst layer on an inorganic base material that exhibits a sufficient photocatalytic action in an environment where there is a large amount of visible light (see, for example, Patent Document 2). ). In Patent Document 2, a photocatalytic action can be exhibited even indoors by using a oxide semiconductor that has been subjected to a modification treatment so as to exhibit a photocatalytic action with visible light.

JP 2011-209658 A JP 2006-68684 A

  However, in patent document 1, it is necessary to laminate | stack the laminated body of an at least 2 layer of an internal scattering layer and a surface shape layer on a board | substrate. Therefore, the technique described in Patent Document 1 has a problem that the configuration of the light diffuser becomes complicated. Moreover, in patent document 2, although deodorizing performance is expressed, antibacterial performance is low and antiviral performance is not expressed.

  The present invention has been made in view of such problems of the prior art. An object of the present invention is to improve the light transmittance and light diffusibility with a simpler configuration, and to exhibit antibacterial performance and antiviral performance, as well as an optical member and illumination using the same. To provide a cover.

  In order to solve the above problems, the coating composition according to the first aspect of the present invention includes an acrylic resin, light diffusion particles, and cuprous oxide. And 40-120 mass parts of light-diffusion particles are included with respect to 100 mass parts of solid content of an acrylic resin. Furthermore, 0.5-5 mass parts of cuprous oxide is contained with respect to 100 mass parts of solid content of an acrylic resin.

  The optical member which concerns on the 2nd aspect of this invention is equipped with a transparent resin base material and the light-diffusion layer provided in the surface on the opposite side of the surface which opposes a light source part in a transparent resin base material. And a light-diffusion layer contains a coating composition.

  The lighting cover according to the third aspect of the present invention includes an optical member.

  According to the present invention, a coating composition capable of improving light utilization efficiency by imparting light transmittance and light diffusibility with a simpler structure, and capable of exhibiting antibacterial performance and antiviral performance. Can be obtained. Furthermore, by using the coating composition, it is possible to obtain an optical member and a lighting cover that are excellent in light transmittance and light diffusibility, antibacterial performance, and antiviral performance.

It is the schematic which shows an example of the lighting fixture which concerns on embodiment of this invention.

  Hereinafter, the coating composition according to the present embodiment, an optical member using the coating composition, and a lighting cover using the optical member will be described in detail.

[Coating composition]
The coating composition according to the present embodiment includes an acrylic resin, light diffusing particles, and cuprous oxide. And a coating composition contains 40-120 mass parts of light-diffusion particles with respect to 100 mass parts of solid content of an acrylic resin, and also a cuprous oxide is 0.5-5 with respect to 100 mass parts of solid content of an acrylic resin. Includes mass parts.

  In the present embodiment, the acrylic resin is a resin obtained by polymerizing a (meth) acrylate monomer. The acrylic resin may be a copolymer of a (meth) acrylate monomer 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 monomer, an olefin monomer, and a vinyl monomer. “(Meth) acrylate” means acrylate or methacrylate.

  Examples of (meth) acrylate monomers include methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) acrylate, glycidyl (meth) acrylate, benzyl (meth) acrylate, stearyl (meth) acrylate, and lauryl. There may be mentioned at least one selected from the group consisting of (meth) acrylate and 2-hydroxy-3-phenoxypropyl (meth) acrylate. Examples of the styrenic monomer include styrene. Examples of the olefin monomer include ethylene and propylene. Examples of the vinyl monomer include vinyl chloride and vinylidene chloride. One of these monomer components may be used alone, or two or more thereof may be mixed and used.

  In this embodiment, the light diffusing particles are not particularly limited as long as the particles can impart light diffusibility to the light diffusing layer made of the coating composition, as will be described later. Examples of the light diffusing particles include at least one selected from the group consisting of benzoguanamine resin particles, styrene particles, silicone particles, melamine resin particles, polytetrafluoroethylene (PTFE) particles, and inorganic particles. Examples of the inorganic fine particles include at least one selected from the group consisting of barium sulfate, calcium carbonate, crystalline silica, amorphous silica, glass flakes, glass fibers, and glass beads.

  In order to use an optical member provided with a light diffusing layer made of a coating composition as an illumination cover, it is necessary to use a light diffusing particle that can impart light diffusibility without impairing visible light transmittance. preferable. From such a viewpoint, the light diffusing particles are particularly preferably benzoguanamine-based resin particles. Examples of the benzoguanamine resin particles include benzoguanamine (2,4-diamino-6-phenyl-1,3,5-triazine), a condensate of benzoguanamine and formaldehyde, a condensate of benzoguanamine, melamine and formaldehyde. it can.

  In the coating composition, the light diffusing particles preferably include 40 to 120 parts by mass with respect to 100 parts by mass of the solid content of the acrylic resin. When the content of the light diffusing particles is less than 40 parts by mass, the light diffusing property of the light diffusing layer is not sufficiently exhibited, and unevenness in brightness and darkness may occur on the light transmitting surface. On the other hand, when the content of the light diffusing particles exceeds 120 parts by mass, the light transmittance of the light diffusing layer is lowered, and the instrument efficiency may be deteriorated. In addition, from a viewpoint of improving both light diffusibility and light transmittance, the content of the light diffusing particles is more preferably 60 to 100 parts by mass with respect to 100 parts by mass of the solid content of the acrylic resin.

  The average particle diameter of the light diffusing particles is preferably 1 μm or more and 10 μm or less. When the average particle diameter of the light diffusing particles is within this range, the light transmittance and light diffusibility of the light diffusing layer can be improved. In order to enhance the light transmittance and the light diffusivity in a suitable thickness range within the light diffusion layer, the average particle diameter of the light diffusion particles is more preferably 1 μm or more and 3 μm or less. The average particle size of the light diffusing particles can be measured by a dynamic light scattering method and obtained by a cumulant analysis method.

  The difference in refractive index between the acrylic resin and the light diffusing particles is preferably 0.1 or more and 0.2 or less. When the refractive index difference between the acrylic resin and the light diffusing particles is 0.1 or more, the light diffusibility of the obtained light diffusing layer can be effectively enhanced. Moreover, when the difference in refractive index between the acrylic resin and the light diffusing particles is 0.2 or less, it is possible to suppress a decrease in light transmittance while enhancing the light diffusibility of the light diffusion layer.

The coating composition of this embodiment contains cuprous oxide in order to impart antibacterial and antiviral properties. Here, many copper compounds exhibiting antibacterial activity have been reported heretofore, but copper (I) oxide (cuprous oxide, Cu ₂ O) is antibacterial as compared with copper (II) oxide (copper oxide, CuO). High activity and antiviral activity. That is, since cuprous oxide easily elutes copper ions, when the eluted copper ions come into contact with microorganisms, they bind to enzymes and proteins to reduce the activity and easily inhibit the metabolic function of microorganisms. Further, the catalytic action of the eluted copper ions converts oxygen in the air into active oxygen, making it easier to decompose microorganism organic matter. Therefore, it is preferable to use particles made of copper (I) as the cuprous oxide.

  Cuprous oxide exhibits high antibacterial performance and antiviral performance regardless of whether it has a crystal structure or an amorphous structure, and when it has a crystal structure, regardless of the crystal structure. Therefore, the crystal structure of cuprous oxide is not particularly limited.

  The average primary particle size of cuprous oxide is preferably 2 nm to 80 nm. Even if the average primary particle diameter of cuprous oxide is outside this range, it is possible to impart antibacterial performance and antiviral performance to the coating composition. However, if the average primary particle diameter of the cuprous oxide particles is less than 2 nm, the surface area of the individual cuprous oxide particles becomes too small, and the cuprous oxide particles may hardly exhibit high antibacterial performance and antiviral performance. Moreover, when the average primary particle diameter of the cuprous oxide particles exceeds 80 nm, it is difficult to make fine particles sufficiently in the dispersion treatment step described later. Moreover, the mass of each cuprous oxide particle increases, and there exists a possibility that it may aggregate and precipitate in a dispersion liquid during a dispersion process and the storage after a process. In addition, the average primary particle diameter of cuprous oxide can be calculated | required by measuring the diameter of a some cuprous oxide particle, for example using a transmission electron microscope (TEM).

  In the coating composition, the cuprous oxide preferably contains 0.5 to 5 parts by mass with respect to 100 parts by mass of the solid content of the acrylic resin. When cuprous oxide is less than 0.5 parts by mass, the effect of adding cuprous oxide is not recognized, and the antibacterial and antiviral properties may not be sufficiently improved. Moreover, when cuprous oxide exceeds 5 mass parts, there exists a possibility that the light transmittance of the obtained light-diffusion layer may fall.

  The coating composition according to this embodiment preferably further contains photocatalyst particles in addition to the acrylic resin, the light diffusing particles and the cuprous oxide. As described above, antibacterial performance and antiviral performance are higher in cuprous oxide than in copper oxide, but cuprous oxide is oxidized in the atmosphere to become copper oxide. Therefore, in order to maintain antibacterial performance and antiviral performance in a high state, it is necessary to reduce oxidized copper oxide. Therefore, by combining photocatalyst particles together with cuprous oxide with respect to the acrylic resin, the copper oxide oxidized by the catalytic action of the photocatalyst particles can be reduced to cuprous oxide. Therefore, the antibacterial performance and antiviral performance of the coating composition can be maintained in a high state for a long period.

  Photocatalyst particles are substances that can generate conduction electrons and holes by excitation of electrons in the valence band when light with an energy larger than the energy gap between the conductor and the valence band is irradiated. If it is, it will not specifically limit. Specific examples of the photocatalyst particles include titanium oxide, tin oxide, tungsten oxide, iron oxide, zinc oxide, chromium oxide, molybdenum oxide, ruthenium oxide, germanium oxide, lead oxide, cadmium oxide, vanadium oxide, niobium oxide, tantalum oxide, Examples thereof include oxides such as manganese oxide, cobalt oxide, rhodium oxide, nickel oxide, rhenium oxide, and zirconium oxide, oxides of these metals, and metal oxides doped with nitrogen or metal ions. Moreover, the metal oxide etc. with which cocatalysts, such as a metal and a metal salt, photosensitizing dye, etc. are carry | supported on the surface are also mentioned. The photocatalyst particles may be used singly or in combination of two or more.

  The average primary particle size of the photocatalyst particles is preferably 5 nm to 200 nm. Even if the average primary particle diameter of the photocatalyst particles is outside this range, the reduction performance of copper oxide can be exhibited. However, if the average primary particle diameter of the photocatalyst particles is less than 10 nm, the surface area of the individual photocatalyst particles becomes too small, and the area in contact with the cuprous oxide may be reduced, thereby making it difficult for the catalytic action to be exhibited. Moreover, when the average primary particle diameter of the photocatalyst particles exceeds 200 nm, scattering by the photocatalyst particles increases, and the light transmittance of the obtained light diffusion layer may be lowered. The average primary particle diameter of the photocatalyst particles can be determined by measuring the diameter of a plurality of photocatalyst particles using, for example, a transmission electron microscope (TEM).

  In the coating composition of this embodiment, it is preferable that 0.5-20 mass parts of photocatalyst particles are included with respect to 100 mass parts of solid content of an acrylic resin. Even if the content of the photocatalyst particles is outside this range, the reduction performance of copper oxide can be exhibited. However, when the amount of the photocatalyst particles is less than 0.5 parts by mass, the content of the photocatalyst particles is small, which may make it difficult to reduce the copper oxide. Moreover, when photocatalyst particle exceeds 20 mass parts, there exists a possibility that the light transmittance of the obtained light-diffusion layer may fall.

  Thus, the coating composition according to the present embodiment includes an acrylic resin, light diffusing particles, and cuprous oxide. And a coating composition contains 40-120 mass parts of light-diffusion particles with respect to 100 mass parts of solid content of an acrylic resin, and also a cuprous oxide is 0.5-5 with respect to 100 mass parts of solid content of an acrylic resin. Including parts by mass. With such a configuration, it is possible to exhibit antibacterial performance and antiviral performance by the effect of cuprous oxide while improving light utilization efficiency by imparting light transmittance and light diffusibility.

  Next, the manufacturing method of the coating composition which concerns on this embodiment is demonstrated. The coating composition can be prepared by mixing the above-mentioned acrylic resin, light diffusing particles and cuprous oxide, and highly dispersing the light diffusing particles and cuprous oxide in the acrylic resin. When the coating composition contains photocatalyst particles, the acrylic resin, light diffusing particles, cuprous oxide and photocatalyst particles are mixed, and the light diffusing particles, cuprous oxide and photocatalyst particles are highly dispersed in the acrylic resin. It is possible to prepare. Therefore, any method can be used as a method for dispersing the light diffusing particles, cuprous oxide and photocatalyst particles in the acrylic resin as long as they can be highly dispersed.

  The coating composition can use an organic solvent in order to enhance the dispersibility of the light diffusing particles and cuprous oxide in the acrylic resin. That is, it can be prepared by mixing an acrylic resin, light diffusing particles and cuprous oxide in an organic solvent and highly dispersing the light diffusing particles and cuprous oxide. The organic solvent is not particularly limited, but it is preferable to appropriately select an organic solvent that volatilizes easily when the light diffusion layer is formed and does not cause curing inhibition during the formation of the light diffusion layer. Examples of the organic solvent include aromatic hydrocarbons (such as toluene and xylene), alcohols (such as methanol, ethanol, and isopropyl alcohol), and ketones (such as acetone, methyl ethyl ketone, and methyl isobutyl ketone). Furthermore, aliphatic hydrocarbons (such as hexane and heptane), ethers (such as tetrahydrofuran), and amide solvents (such as N, N-dimethylformamide (DMF) and dimethylacetamide (DMAc)) may be mentioned. Of these, aromatic hydrocarbons and alcohols are preferred. These organic solvents may be used individually by 1 type, and may be used in combination of 2 or more type.

  However, from the viewpoint of enhancing the dispersibility of the cuprous oxide in the acrylic resin and facilitating securing the light transmittance of the light diffusion layer, a cuprous oxide dispersion in which cuprous oxide is dispersed in advance is prepared, It is preferable to mix the cuprous oxide dispersion, the acrylic resin, and the light diffusing particles.

  The cuprous oxide dispersion contains cuprous oxide particles, a nonionic surfactant, and an organic solvent. The cuprous oxide particles preferably have an average primary particle diameter of 2 nm to 80 nm, and an average secondary particle diameter measured by a dynamic light scattering method and obtained by a cumulant analysis method is preferably 50 nm to 150 nm. By using such a cuprous oxide dispersion, even when the concentration of cuprous oxide in the acrylic resin is increased, the dispersibility of the cuprous oxide can be maintained in a high state. As a result, it is possible to increase the light transmittance of the obtained light diffusion layer, and to further improve the antibacterial performance and antiviral performance.

  The addition amount of the nonionic surfactant in the cuprous oxide dispersion is not particularly limited, but is preferably 5 to 100 parts by mass, more preferably 20 to 90 parts by mass with respect to 100 parts by mass of the cuprous oxide particles. The amount is preferably 30 to 70 parts by mass. With such an addition amount, it is possible to suppress the inhibition of curing of the light diffusion layer and the deterioration of physical properties while improving the dispersibility of the cuprous oxide particles.

  The addition amount of the organic solvent in the cuprous oxide dispersion is not particularly limited, but is preferably 500 to 10,000 parts by mass, more preferably 1000 to 5000 parts by mass with respect to 100 parts by mass of the cuprous oxide particles. With such an addition amount, it is possible to suppress an excessive increase in viscosity while improving the dispersibility of the cuprous oxide particles.

  In addition, from a viewpoint of improving the light transmittance of the obtained light-diffusion layer, it is preferable that the average secondary particle diameter of the cuprous oxide particle in a cuprous oxide dispersion liquid is 50 nm-150 nm. The average secondary particle diameter of the cuprous oxide particles can be measured by a dynamic light scattering method and determined by a cumulant analysis method.

  As the organic solvent in the cuprous oxide dispersion, aromatic hydrocarbons (toluene, xylene, etc.), alcohols (methanol, ethanol, isopropyl alcohol, etc.), ketones (acetone, methyl ethyl ketone, and methyl isobutyl ketone) are the same as described above. Etc.). Furthermore, aliphatic hydrocarbons (such as hexane and heptane), ethers (such as tetrahydrofuran), and amide solvents (such as N, N-dimethylformamide (DMF) and dimethylacetamide (DMAc)) may be mentioned. Of these, aromatic hydrocarbons and alcohols are preferred. These organic solvents may be used individually by 1 type, and may be used in combination of 2 or more type.

  Nonionic surfactants include fatty acid sorbitan esters and their polyalkylene oxide adducts, fatty acid polyglycol esters, various polyalkylene oxide type nonionic surfactants (polyoxyethylene fatty acid esters, polyoxyethylene fatty acid amides, polyoxyethylenes). Aliphatic amine, polyoxyethylene aliphatic mercaptan, polyoxyethylene alkylaryl ether, polyoxyethylene polyoxypropylene block polymer, polyoxyethylene aralkyl aryl ether, polyoxyethylene distyrenated phenol ether phosphate, etc.) . Among these, phosphate ester type anionic surfactants are desirable as dispersants that do not exhibit a decrease in antibacterial activity.

  Examples of the phosphate ester type anionic surfactant include alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, and the like. More specifically, alkyl phosphate ester, polyoxyethylene alkyl ether phosphate ester, polyoxyethylene (mono or di) alkyl phenyl ether phosphate ester, polyoxyethylene (mono, di or tri) alkyl phenyl ether polymer phosphate ester , Polyoxyethylene (mono, di or tri) phenyl phenyl ether phosphate, polyoxyethylene (mono, di or tri) benzyl phenyl ether phosphate, polyoxyethylene (mono, di or tri) styryl phenyl ether phosphate, poly Phosphoric ester of polymer of oxyethylene (mono, di or tri) styryl phenyl ether, phosphoric ester of polyoxyethylene polyoxypropylene block polymer, phosphatidylcholine, phosphatidi Phosphate esters such as ethanol imine and condensation phosphoric acid (e.g., tripolyphosphate, etc.), and salts of these phosphate esters.

  The cuprous oxide dispersion can be prepared by mixing the above-described cuprous oxide particles, nonionic surfactant and organic solvent, and highly dispersing the cuprous oxide particles in the organic solvent. Therefore, any method can be used as a method of dispersing cuprous oxide particles in an organic solvent as long as the cuprous oxide particles can be highly dispersed.

  However, from the viewpoint of enhancing the dispersibility of the cuprous oxide particles and ensuring the light transmittance of the light diffusion layer, it is preferable to carry out the dispersion process of the cuprous oxide particles separately in the pre-dispersion process and the main dispersion process. As a result, the surface of the cuprous oxide particles is wetted and the air layer on the surface is replaced with the organic solvent, so that the dispersion proceeds promptly in the subsequent main dispersion treatment. If this pre-dispersion treatment is insufficient, the progress of dispersion is slow, and there is a risk that useless mechanical impact is imparted to the cuprous oxide particles. As a result, the crystal structure itself of the cuprous oxide particles may be destroyed, resulting in a dispersion with reduced stability.

  The pre-dispersion treatment may be stirred using a general dissolver. However, it is preferable to stir with a high-speed stirrer from the viewpoint of making the surface of the cuprous oxide particles easy to wet. As a high-speed stirrer, for example, T.M. K. Homomixer, T.W. K. Robomix and T. K. Fillmix (trade name, manufactured by Primix Co., Ltd.) can be used. In addition, Claremix (registered trademark) (trade name, manufactured by M Technique Co., Ltd.) and Ultra Disper (trade name, manufactured by Asada Tekko Co., Ltd.) can also be used.

  Examples of a dispersion apparatus that performs this dispersion processing include a kneader, a two-roll, a three-roll, SS5 (trade name, M Technique Co., Ltd.), and Miracle KCK (registered trademark) (trade name, manufactured by Asada Tekko Co., Ltd.). Such a kneader can be used. Moreover, an ultrasonic disperser, a microfluidizer (trade name, manufactured by Mizuho Kogyo Co., Ltd.) that is a high-pressure homogenizer, and NanoVita (registered trademark) (trade name, manufactured by Yoshida Kikai Kogyo Co., Ltd.) are also included. Furthermore, Starburst (registered trademark) (trade name, Sugino Machine Co., Ltd.), G-smasher (trade name, Rix Co., Ltd.) and the like are also included. For those using bead media such as glass and zircon, ball mills, bead mills, sand mills, horizontal media mill dispersers, colloid mills and the like can be used. As a medium used in the bead mill, a bead medium having a diameter of 1 mm or less is preferable, and a bead medium having a diameter of 0.5 mm or less is more preferable. In addition, what is necessary is just to adjust suitably the dispersion time of a pre-dispersion process and this dispersion process with each dispersion apparatus and media so that a cuprous oxide particle may be highly dispersed in an organic solvent with a nonionic surfactant.

  In addition, when supplying the pre-dispersed treatment liquid to the dispersing device, it can be processed in a shorter time by supplying it with sufficient stirring using a high-speed stirrer or the like. is there.

[Optical member]
Next, the optical member according to the present embodiment will be described. The optical member of the present embodiment includes a transparent resin base material and a light diffusion layer provided on the surface of the transparent resin base material opposite to the surface facing the light source unit. And a light-diffusion layer contains a coating composition. As described above, since the coating composition of the present embodiment contains a predetermined amount of light diffusing particles with respect to the acrylic resin, the light diffusibility of the obtained light diffusing layer is enhanced, and unevenness of light and darkness on the translucent surface. Can be suppressed. Moreover, since the coating composition contains a predetermined amount of cuprous oxide with respect to the acrylic resin, it is possible to impart antibacterial performance and antiviral performance to the obtained light diffusion layer.

  The optical member of this embodiment is provided with a light diffusion layer on one surface of a transparent resin base material, and can be stretch-molded according to a predetermined shape. That is, as described above, since the light diffusion layer is made of an acrylic resin that is a thermoplastic resin, if the transparent resin base material is thermoplastic, the light diffusion layer can be followed to be stretch-molded. It is.

  Although it will not specifically limit if it is transparent as a transparent resin base material, The thing whose total light transmittance is 90% or more is preferable. As a transparent resin base material, what was formed by at least 1 type chosen from the group which consists of an acrylic resin (polymer of acrylic ester or methacrylic ester), a polycarbonate resin, and a styrene resin can be used, for example. Among them, acrylic resin and polycarbonate resin have high light transmittance. Therefore, it is preferable that the transparent resin base material is formed by at least one of acrylic resin and polycarbonate resin.

  Although the thickness of a transparent resin base material is not specifically limited, For example, it is preferable that it is 0.1 mm-3 mm. In consideration of moldability and strength, the thickness of the transparent resin substrate is more preferably 1 mm to 2 mm. In addition, what was obtained by sheet molding methods, such as a glass cast manufacturing method, a continuous cast manufacturing method, an extrusion manufacturing method, can be used for a transparent resin base material.

  The light diffusion layer is preferably formed so as to have a film thickness of 5 μm to 15 μm. Usually, the light diffusion layer is formed so that the film thickness is 5 μm or more and 50 μm or less. However, considering the function, productivity, cost, etc., the light diffusion layer is formed so that the film thickness becomes 5 μm or more and 15 μm or less. It is preferred to form a layer. Therefore, the resin or light diffusing particles used as the light diffusing layer is appropriately selected so that the film thickness necessary for imparting suitable light transmittance and light diffusibility falls within the range of 5 μm to 15 μm. preferable.

  In the optical member according to the present embodiment, the light diffusion layer can be formed by applying a coating composition to a transparent resin substrate. The method of applying 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. And when a coating composition contains an organic solvent, a light-diffusion layer can be formed in the surface of a transparent resin base material by removing an organic solvent by heating etc.

  As described above, in the optical member of the present embodiment, the transparent resin base material only exhibits a single light diffusion layer and exhibits antibacterial performance and antiviral performance in addition to excellent light transmission and light diffusion properties. It becomes possible.

[Lighting cover]
Next, the lighting cover of this embodiment will be described. The illumination cover of this embodiment includes the above-described optical member.

  The lighting cover is preferably mounted so as to cover a lamp as a light source unit, for example. At this time, the light emitting unit may be entirely covered or attached, or a part of the light emitting unit may be covered. In order to make the shape covering the lamp, it is preferable to mold by pressing and stretching from the surface of the resin sheet on the substrate side (the side opposite to the light diffusion layer). If it shape | molds in this way, a light-diffusion layer will be arrange | positioned on the outer surface of a molded article.

  Moreover, it is preferable that the illumination cover is a type of cover that is milky white and is accompanied by diffusion of light, thereby softening the light from the lamp and softening the lamp image. Therefore, the lighting cover preferably has a total light transmittance of 30% or more, and more preferably has a total light transmittance of 40% or more. If the total light transmittance is 30% or more, the light from the lamp can be moderated moderately without being too dark. Moreover, it is more preferable that the light cover has a total light transmittance of 70% or less. If the total light transmittance is 70% or less, sufficient brightness can be obtained while softening the light from the lamp.

  Such a lighting cover can be used for various lighting fixtures. For example, it can be suitably used for a ceiling light, a pendant type light, a sink lamp, a bathroom lamp, a chandelier, a stand, a bracket, a cover for a banquet, etc. Also for garage lights, eaves lights, gatepost lights, porch lights, garden lights, entrance lights, footlights, stair lights, guide lights, security lights, downlights, base lights, electric signs, sign lights, etc. It can be used suitably. Furthermore, it can be suitably used for a cover for a vehicular lamp such as an automobile or a motorcycle. In particular, it can be suitably used for a ceiling light or the like having a structure in which a cover is sandwiched between instrument bodies. Since the above optical member has appropriate strength and flexibility, it can be fitted into a portion sandwiched by the flexibility while improving the impact resistance by the strength.

  FIG. 1 shows an example of a lighting fixture 10 in which the lighting cover 1 is used. The luminaire 10 is a circular ceiling light that is installed on the ceiling 4 of a house. The lighting fixture 10 includes a lamp 2 that serves as a light emitter, a fixture main body 3 that holds the lamp 2 and is attached to a ceiling 4, and a lighting cover 1 that is formed by an optical member.

  The lighting cover 1 has a substantially C-shaped cross section and covers the lamp 2 and is attached to the fixture body 3 from below. In the illumination cover 1, a light diffusion layer is disposed on the outer surface opposite to the lamp 2. At the upper end portion of the illumination cover 1, an engagement portion 11 for hooking on the instrument body 3 is provided. In the illustrated form, the engaging portion 11 is formed to protrude inward. The engaging portion 11 may be provided over the entire circumference of the lighting cover 1 or may be provided in part.

  The fixture body 3 is provided with an engaged portion 31 that engages with the engaging portion 11 of the illumination cover 1. In the illustrated form, the engaged portion 31 is formed to protrude outward. In addition, the instrument body 3 is provided with a support portion 32 that protrudes downward from a position outside the instrument body 3 relative to the engaged portion 31. The support portion 32 supports the illumination cover 1 from the outside so that the illumination cover 1 is not displaced or rattled. The engaged portion 31 and the support portion 32 may be provided over the entire circumference of the instrument body 3 or may be provided in part.

  As described above, the illumination cover 1 includes the above-described optical member. And since the outer surface is the light-diffusion layer, the illumination cover 1 has a high antibacterial performance and antiviral performance. Moreover, light resistance improves because the light-diffusion layer is formed with the acrylic resin, and suitable light transmittance and light diffusibility are obtained.

  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]
80 parts by mass of light diffusing particles and 1% by mass of cuprous oxide mixed with the solid content of 100 parts by mass of the acrylic resin were mixed. Then, the mixture was diluted with cyclohexanone so that the total nonvolatile content was 20%, and further stirred with a disper at a rotation speed of 2000 rpm for 20 minutes to obtain a coating material of this example. In addition, the acrylic resin used WAL-578 by DIC Corporation whose solid content is 50 mass%. The refractive index of the acrylic resin is 1.49. The light diffusing particles used were benzoguanamine formaldehyde condensate (Nippon Shokubai Eposter MS). The light diffusion particles have an average particle diameter of 2 μm and a refractive index of 1.66. As the cuprous oxide, cuprous oxide particles (CuO reduction, average primary particle diameter 50 nm) manufactured by Sigma-Aldrich Co. were used.

  In addition, cuprous oxide mixed 1000 mass parts of methyl ethyl ketone as an organic solvent and 30 mass parts of nonionic surfactant with respect to 100 mass parts of cuprous oxide particles, and the cuprous oxide dispersion liquid ( Solid content 9% by mass) was used. In addition, DISPARLON (registered trademark) PW-36 (phosphate ester type anionic surfactant) manufactured by Enomoto Kasei Co., Ltd. was used as a nonionic surfactant.

  The coating material obtained as described above was applied to one side of a transparent acrylic extruded plate so that the thickness of the obtained light diffusion layer was 8 μm. And the optical member of this example was produced by drying a coating film. In addition, the transparent acrylic extrusion board (Sumipex (trademark) E000) was used as a transparent resin base material.

[Example 2]
A coating material was prepared in the same manner as in Example 1 except that 40 parts by mass of light diffusing particles were used with respect to 100 parts by mass of the solid content of the acrylic resin, thereby obtaining an optical member of this example.

[Example 3]
A coating material was prepared in the same manner as in Example 1 except that 120 parts by mass of light diffusing particles was used with respect to 100 parts by mass of the solid content of the acrylic resin, and an optical member of this example was obtained.

[Example 4]
A coating material was prepared in the same manner as in Example 1 except that cuprous oxide having a solid content of 0.5 parts by mass was used with respect to 100 parts by mass of the acrylic resin, and an optical member of this example was obtained. It was.

[Example 5]
A coating material was prepared in the same manner as in Example 1 except that cuprous oxide having a solid content of 5 parts by mass was used with respect to 100 parts by mass of the acrylic resin, and an optical member of this example was obtained.

[Example 6]
80 parts by mass of light diffusing particles, cuprous oxide having a solid content of 1 part by mass, and titanium oxide having a solid content of 5 parts by mass were mixed with respect to 100 parts by mass of the solid content of the acrylic resin. Then, the mixture was diluted with cyclohexanone so that the total nonvolatile content was 20%, and further stirred with a disper at a rotation speed of 2000 rpm for 20 minutes to obtain a coating material of this example. In addition, the acrylic resin used WAL-578 by DIC Corporation whose solid content is 50 mass%. The refractive index of the acrylic resin is 1.49. The light diffusing particles used were benzoguanamine formaldehyde condensate (Nippon Shokubai Eposter MS). The light diffusion particles have an average particle diameter of 2 μm and a refractive index of 1.66. As the cuprous oxide, cuprous oxide particles (CuO reduction, average primary particle diameter 50 nm) manufactured by Sigma-Aldrich Co. were used. As the titanium oxide, ST-01 (average primary particle size: 7 nm, crystal structure: anatase) manufactured by Ishihara Sangyo Co., Ltd. was used.

  In addition, cuprous oxide mixed 1000 mass parts of methyl ethyl ketone as an organic solvent and 30 mass parts of nonionic surfactant with respect to 100 mass parts of cuprous oxide particles, and the cuprous oxide dispersion liquid ( Solid content 9% by mass) was used. In addition, DISPARLON (registered trademark) PW-36 (phosphate ester type anionic surfactant) manufactured by Enomoto Kasei Co., Ltd. was used as a nonionic surfactant.

  Titanium oxide is a titanium oxide dispersion (solid content) in which 500 parts by mass of diethylene glycol monomethyl ether as an organic solvent and 30 parts by mass of a nonionic surfactant are mixed with 100 parts by mass of titanium oxide particles. 16% by mass) was used. As the nonionic surfactant, Uniol (registered trademark) TG-1000 (polyoxypropylene glyceryl ether, weight average molecular weight Mw: 1000) manufactured by NOF Corporation was used.

  The coating material obtained as described above was applied to one side of a transparent acrylic extruded plate so that the thickness of the obtained light diffusion layer was 8 μm. And the optical member of this example was produced by drying a coating film. In addition, the transparent acrylic extrusion board (Sumipex (trademark) E000) was used as a transparent resin base material.

[Example 7]
A coating material was prepared in the same manner as in Example 6 except that titanium oxide having a solid content of 0.5 parts by mass was used with respect to 100 parts by mass of the acrylic resin, and an optical member of this example was obtained. It was.

[Example 8]
A coating material was prepared in the same manner as in Example 6 except that titanium oxide having a solid content of 20 parts by mass was used with respect to 100 parts by mass of the acrylic resin, and an optical member of this example was obtained.

[Comparative Example 1]
A coating material was prepared in the same manner as in Example 1 except that 20 parts by mass of light diffusing particles were used with respect to 100 parts by mass of the solid content of the acrylic resin, and an optical member of this example was obtained.

[Comparative Example 2]
A coating material was prepared in the same manner as in Example 1 except that 200 parts by mass of light diffusing particles were used with respect to 100 parts by mass of the solid content of the acrylic resin, and an optical member of this example was obtained.

[Comparative Example 3]
A coating material was prepared in the same manner as in Example 1 except that cuprous oxide having a solid content of 0.05 part by mass was used with respect to 100 parts by mass of the acrylic resin, and an optical member of this example was obtained. It was.

[Comparative Example 4]
A coating material was prepared in the same manner as in Example 1 except that cuprous oxide having a solid content of 10 parts by mass was used with respect to 100 parts by mass of the acrylic resin, and an optical member of this example was obtained.

[Evaluation]
(1) Light transmittance evaluation The total light transmittance of the optical member of each example was measured using the haze meter ("NDH2000" by Nippon Denshoku Industries Co., Ltd.). The measurement was performed with the light diffusion layer side facing the light source part. If the total light transmittance is 60% or more, there is light uniformity, and there is no lamp image, it can be said that both excellent instrument efficiency and light uniformity can be achieved. It was.
・ Criteria> 70%: ◎
60-70%: ○
Less than 60%: ×

(2) Evaluation of light diffusivity Using a square base light XL524PFULT9 manufactured by Panasonic Corporation, the ability to erase the lamp image of each optical member was visually confirmed. Specifically, the optical member of each example is cut into a size (350 mm × 350 mm) suitable for this instrument, and observed with the light diffusion layer side facing the light source, and the light diffusivity is evaluated according to the following criteria. did.
-Criteria A: The light source shape cannot be confirmed and is uniform.
B: Although the light source shape is blurred, the interval between adjacent LED light sources can be determined.
C: The light source shape can be confirmed.

(3) Chromaticity Evaluation Using a spectrocolorimeter (CM-700d manufactured by Konica Minolta Co., Ltd.), the chromaticity (b ^* ) of each optical member was measured and evaluated according to the following criteria. In addition, the black surface of the concealment rate measurement paper (made by Motofuji) was used for the base which installs a sample at the time of evaluation.
・ Criteria A: b ^* ≦ 5
B: 5 <b ^* <10
C: b ^* ≧ 10

(4) Antibacterial performance Using Escherichia coli, the antibacterial performance was evaluated based on Japanese Industrial Standard JIS R1702 (Fine ceramics-Antibacterial test method / antibacterial effect of photocatalyst antibacterial processed product). Irradiation conditions were a fluorescent lamp with a wavelength of less than 380 nm cut and 1000 lx for 4 hours. The antibacterial activity value R (antibacterial) was calculated from the following formula.
R (antibacterial) = Log (B / C)
R (antibacterial): antibacterial activity value of optical member under the above irradiation conditions B: number of viable bacteria after irradiating the glass plate with light under the above irradiation conditions (number)
C: Viable count (number) after irradiating the optical member with light under the above irradiation conditions

(5) Antiviral performance evaluation Antiviral performance evaluation was performed based on JIS R1702 using bacteriophage. Irradiation conditions are as follows: a phage solution (1 × 109 PFU / mL) prepared on a glass plate or an optical member is dropped, and then covered with an OHP film and irradiated at 1000 lx for 2 hours using a fluorescent lamp with a wavelength of less than 380 nm cut. That's it. And after irradiating light, the phage solution on a glass plate or an optical member was collect | recovered, after colon_bacillus | E._coli was mixed and infected and culture | cultivated, the number of E. coli plaques infected with phage was counted. Moreover, the inactivation rate R (antiviral) of antiviral performance was calculated from the following formula.
R (antiviral) = Log (D / E)
R (antiviral): Inactivation rate of the antiviral performance of the optical member under the above irradiation conditions D: Number of plaques after the glass plate was irradiated with light under the above irradiation conditions (pieces)
E: Number of plaques after the optical member is irradiated with light under the above irradiation conditions (number)

  In Example 1, it was confirmed that antibacterial performance and antiviral performance were expressed while achieving both light transmittance and light diffusibility. Further, in Example 2, the amount of light diffusing particles was reduced, and in Example 4, the amount of cuprous oxide was reduced, thereby confirming that the light transmittance was improved while exhibiting antibacterial performance and antiviral performance. . On the other hand, in Example 3, since the amount of the light diffusing particles was increased, the light diffusibility was improved. In Example 5, since the amount of cuprous oxide was increased, antibacterial performance and antiviral performance were improved. Moreover, in Example 6, Example 7, and Example 8, it confirmed that antibacterial performance and antiviral performance could be improved further according to each addition amount by compounding a titanium oxide.

  On the other hand, in Comparative Example 1, since the content of the light diffusing particles was small, the diffusibility was poor, and the light source shape was confirmed visually. On the other hand, in Comparative Example 2, there was no problem in diffusibility because the content of the light diffusing particles was large, but the light transmittance was remarkably lowered. Moreover, in comparative example 3, since there was little content of cuprous oxide, antibacterial performance and antiviral performance fell. In Comparative Example 4, since the content of cuprous oxide was large, antibacterial performance and antiviral performance were exhibited, but coloring was confirmed by cuprous oxide.

  In addition, from Examples 1-3 and Comparative Examples 1-2, when content of a light diffusing particle is increased in the state where content of cuprous oxide is constant, it turns out that antibacterial performance and antiviral performance improve. This is presumably because the ratio of cuprous oxide exposed on the surface of the light diffusion layer increases due to the increase in light diffusion particles. However, when the content of the light diffusing particles is too small as in Comparative Example 1, the light diffusibility is lowered, and when the content of the light diffusing particles is excessive as in Comparative Example 2, the light transmittance is decreased. Decreases. Therefore, it is preferable that a light-diffusion particle is 40-120 mass parts with respect to 100 mass parts of solid content of an acrylic resin.

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

  1 Lighting cover

Claims (7)

An acrylic resin, light diffusing particles, and cuprous oxide,
The light diffusing particles include 40 to 120 parts by mass with respect to 100 parts by mass of the solid content of the acrylic resin,
The coating composition containing 0.5-5 mass parts of said cuprous oxide with respect to 100 mass parts of solid content of the said acrylic resin.   The coating composition according to claim 1, wherein the light diffusion particles have an average particle diameter of 1 μm to 10 μm, and the cuprous oxide has an average primary particle diameter of 2 nm to 80 nm.   The coating composition according to claim 1 or 2, wherein the light diffusing particles have a refractive index difference of 0.1 or more and 0.2 or less with respect to the acrylic resin.   The coating composition as described in any one of Claims 1 thru | or 3 which contains 0.5-20 mass parts of photocatalyst particles with respect to 100 mass parts of solid content of the said acrylic resin.   The coating composition of Claim 4 whose average primary particle diameter of the said photocatalyst particle is 5 nm-200 nm. A transparent resin substrate;
A light diffusion layer provided on a surface opposite to the surface facing the light source in the transparent resin substrate;
With
The optical member in which the said light-diffusion layer contains the coating composition as described in any one of Claims 1 thru | or 5. A lighting cover comprising the optical member according to claim 6.

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