JP2009275456A - Lighting building material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting building material excellent in lighting property and not dazzling a person even if the person looks at the sun through the lighting building material. <P>SOLUTION: The lighting building material has an acceptance angle, which causes the total light transmittance of 50%, of not smaller than 20° on the condition that the total light transmittance is 100% at an exit angle of 0° and an acceptance angle of 0° under a total light transmittance of not lower the 60%. The building material comprises a light diffusion layer containing a transparent resin and fine particles having a mean particle size of 1-20 μm and an index of refraction different from that of the transparent resin by 0.05 or more. Preferably, 2-20 mass% of the fine particles is contained in 100 mass% of the light diffusion layer, and the thickness of the light diffusion layer is 20-1,200 μm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a daylighting building material suitable as a roofing material or a side plate, and more particularly, daylighting that can be daylighted and that humans do not feel dazzling even if they directly view the sun through the plate material. This is related to the property building materials.

  Conventionally, it is known that a synthetic resin plate material is used as a roof material or a side plate such as a carport, a terrace, or a veranda. In such a plate material, it is necessary to have a balance between the light shielding property for blocking the heat of sunlight and the daylighting property for taking in the brightness, and at the time of plate material production, an inorganic filler is blended to make milky white, It has been colored by blending pigments. However, when milky white plate material is used as a roofing material, it is inferior in daylighting and tends to be dark. In addition, the coloring type plate material has a problem that it cannot be seen directly because it is too dazzling when the sun is seen through this.

On the other hand, Patent Document 1 discloses a synthetic resin plate having an improved embossed portion and a transparent pattern portion as a synthetic resin plate having improved daylighting performance while maintaining blindness, but the light transmittance of the pattern portion is Since it is configured to be high, it was still dazzling and could not be seen directly when the sun was seen through the pattern.
JP 2005-82960 A

  Therefore, in the present invention, an object is to provide a daylighting building material that is excellent in daylighting and that does not dazzle even when the sun is seen through it.

  The present invention that has solved the above problems has a total light transmittance of 60% or more, a light transmittance of 50% when the light transmittance at a light emission angle of 0 ° and a light receiving angle of 0 ° is 100%. The light receiving angle is 20 ° or more.

  The daylighting building material includes a light diffusion layer including a transparent resin and fine particles having an average particle diameter of 1 to 20 μm and a refractive index difference with the transparent resin of 0.05 or more. A configuration in which the amount of fine particles is 2 to 20% by mass and the thickness of the light diffusion layer is 20 to 1200 μm is preferable.

When the thickness of the light diffusion layer is t (μm), the concentration of fine particles in the light diffusion layer is c (mass%), and the average particle diameter is d (μm), it is preferable that the following equation is satisfied.
250 ≦ (t · c) / d ≦ 2000

  The configuration in which the ultraviolet absorbing layer is provided in the outermost layer and the configuration in which the transparent resin is polycarbonate are both preferred embodiments of the present invention.

  Since the daylighting construction material of the present invention has good daylighting, for example, when it is used as a roofing material for a carport, it is possible to secure a sufficient brightness in the carport even when it is cloudy or raining. Moreover, since it is excellent in light diffusibility, even if it looked directly at the sun through this daylighting construction material, it was not dazzling and the daylighting construction material kind to a user was able to be provided.

  Accordingly, the daylighting building material of the present invention can be used as a roofing material or a side plate such as a carport, a terrace, or a veranda.

  The daylighting building material of the present invention is required to have a total light transmittance of 60% or more, and more preferably 70% or more. This is to improve the daylighting property. As the total light transmittance, a value measured by a method defined in JIS K7361-1 is adopted. As a measuring device, for example, a haze meter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd. can be used.

Further, the daylighting building material of the present invention must have a light receiving angle of 20 ° or more when the light transmittance is 50% when the light transmittance at the light emission angle of 0 ° and the light receiving angle of 0 ° is 100%. . This value is a measure of light diffusivity, and if this light receiving angle is 20 ° or more, it will not be dazzling even when the sun is directly viewed. 30 degrees or more is more preferable. The light receiving angle (D ₅₀ ) at which the light transmittance is 50% when the light transmittance at a light emission angle of 0 ° and a light receiving angle of 0 ° is 100% is a spectral color change color difference meter (for example, NEC Corporation). The color transmittance is obtained by measuring the light transmittance while changing the light receiving angle.

  In order to satisfy the above-mentioned requirements, as a daylighting building material, a light diffusing layer including a transparent resin and fine particles having an average particle diameter of 1 to 20 μm and a refractive index difference with the transparent resin of 0.05 or more is provided. Is preferably used. The amount of the fine particles is preferably 2 to 20% by mass in 100% by mass of the light diffusion layer, and the thickness of the light diffusion layer is preferably 20 to 1200 μm. The daylighting building material may be composed only of the light diffusion layer.

  If the average particle size of the fine particles is smaller than 1 μm, secondary aggregation may occur and the light diffusion effect may be insufficient. If the average particle size exceeds 20 μm, the amount of scattered light passing through the light diffusion layer decreases, and the total light transmittance is increased. May become too large. The lower limit of the average particle diameter is more preferably 2 μm. Further, the upper limit is more preferably 10 μm, and further preferably 4 μm. The average particle diameter is a value obtained by simply averaging the particle diameters of 100 arbitrarily selected fine particles when observed with a microscope. When the fine particles are not true spheres, for example, in the case of an elliptical sphere, the average particle diameter is (major axis + minor axis) / 2, and in the case of other shapes, the average of the maximum diameter and the minimum diameter is the average particle diameter.

  If the difference between the refractive index of the transparent resin used as the matrix and the refractive index of the fine particles (refractive index difference: absolute value) is 0.05 or more, the light is greatly refracted at the interface between the resin and the fine particles. It is preferable because it can be diffused and the glare does not occur even when looking directly at the sun. The absolute value of the refractive index difference is more preferably 0.07 or more, and further preferably 0.09 or more. The upper limit of the absolute value of the refractive index difference is not particularly limited, but is preferably 2.0 or less, and more preferably 1.5 or less. In addition, what is necessary is just to employ | adopt the value measured with the catalog value or the multiwavelength Abbe refractometer (for example, DR-M2, Atago Co., Ltd.) for the refractive index of resin or particle | grains.

  In order to express the light diffusion effect as described above, the content of fine particles is preferably 2 to 20% by mass in 100% by mass of the light diffusion layer. If it is less than 2% by mass, the light diffusion effect may be insufficient, and if it is more than 20% by mass, the total light transmittance may be small.

  The thickness of the light diffusion layer is preferably 20 to 1200 μm. If it is thinner than 20 μm, the light diffusion effect may be insufficient, and if it is thicker than 1200 μm, the total light transmittance may be reduced. The lower limit of the more preferable thickness is 30 μm, more preferably 80 μm, and particularly preferably 100 μm. Moreover, the upper limit of more preferable thickness is 1000 micrometers, More preferably, it is 700 micrometers.

Further, when the thickness of the light diffusion layer is t (μm), the concentration of fine particles in the light diffusion layer is c (mass%), and the average particle diameter is d (μm), it is preferable to satisfy the following formula.
250 ≦ (t · c) / d ≦ 2000

  This is because if (t · c) / d is 250 or more and 2000 or less, the balance between the total light transmittance and the light diffusibility is improved.

  Examples of the fine particles for diffusing light include (meth) acrylic resins such as polymethyl methacrylate; styrene resins such as polystyrene; amino-based formalins that are condensates of amino compounds such as melamine and benzoguanamine and formaldehyde. Crosslinked resin; Polyurethane resin; Polyester resin; Silicone resin; Fluorine resin; Organic fine particles such as these copolymers; Clay compounds such as smectite and kaolinite; Inorganic oxides such as silica, titania, alumina, zirconia Inorganic calcium fine particles such as calcium carbonate, aluminum hydroxide, hollow or solid glass particles; and silica composite resin particles of transparent or translucent resin and silica fine particles. Among these materials, organic fine particles such as (meth) acrylic resins, styrene resins, amino formalin cross-linked resins, and silicone resins are suitable as light diffusing agents because of their moderate hardness and resistance to scratches. . Further, for example, the Eposter (registered trademark) series manufactured by Nippon Shokubai Co., Ltd. is suitable as a fine particle for light diffusion.

  The fine particles may be formed of a single material or may be formed of two or more materials. Examples of the shape of the fine particles include a spherical shape, a plate shape, an ellipsoid shape, a saddle shape, a polygonal shape, a disk shape, a star shape, and a surface wrinkle shape.

  Transparent resin that is a matrix resin includes polycarbonate resin; (meth) acrylic resin; styrene resin such as polystyrene and MS resin; lactone ring-containing resin; vinyl acetate resin; olefin resin such as polyethylene and polypropylene; norbornene Examples thereof include cyclic olefin resins such as resins; vinyl chloride resins; vinylidene chloride resins; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; and copolymers thereof. These resins may be used alone or in combination of two or more. Of these resins, polycarbonate, polymethyl methacrylate, MS resin, polystyrene and the like are preferable. Of these, polycarbonate resins are particularly preferred because of their excellent impact resistance, heat resistant temperature, hygroscopic dimensional stability, flame retardancy, and the like.

  The polycarbonate resin is obtained, for example, by reacting a dihydric phenol and a carbonate precursor by an interfacial polycondensation method or a melting method.

  Examples of the dihydric phenol include 2,2-bis (4-hydroxyphenyl) propane [commonly known as bisphenol A], 1,1-bis (4-hydroxyphenyl) ethane, and 1,1-bis (4-hydroxyphenyl). Cyclohexane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) sulfide, bis (4 -Hydroxyphenyl) sulfone and the like. These dihydric phenols may be used alone or in combination of two or more. Of these dihydric phenols, bisphenol A is particularly preferred.

  Examples of the carbonate precursor include carbonyl halide, carbonate ester, and haloformate. Specifically, for example, phosgene, diphenyl carbonate, dihaloformate of dihydric phenol, and the like are used.

  When producing polycarbonate resin by reacting the above dihydric phenol and carbonate precursor by interfacial polycondensation method or melting method, oxidation of catalyst, terminal terminator, dihydric phenol, if necessary An inhibitor or the like may be used.

  The polycarbonate resin is a polyester carbonate resin obtained by copolymerizing an aromatic or aliphatic difunctional carboxylic acid, even if it is a branched polycarbonate resin copolymerized with a trifunctional or higher polyfunctional aromatic compound. It may also be a mixture obtained by mixing two or more of the obtained polycarbonate resins.

The molecular weight of the polycarbonate-based resin is preferably 15,000 or more and 40,000 or less, more preferably 18,000 or more and 35,000 or less in terms of viscosity average molecular weight. The viscosity average molecular weight is a value obtained by inserting the specific viscosity (ηsp) obtained from a solution obtained by dissolving 0.7 g of a polycarbonate resin in 100 mL of methylene chloride at 20 ° C. into the following equation.
ηsp / c = [η] + 0.45 × [η] ² c
[Η] = 1.23 × 10 ⁻⁴ M ^0.83
(Where c = 0.7, [η] is the intrinsic viscosity, M is the viscosity average molecular weight)

  For polycarbonate resins, heat stabilizers such as phosphorous acid, phosphoric acid, phosphorous acid ester, phosphoric acid ester, phosphonic acid ester; ultraviolet light such as triazole based, acetophenone based, salicylic acid ester based Absorber; Bluing agent; Tetrabromobisphenol A, low molecular weight polycarbonate of tetrabromobisphenol A, flame retardant such as decabromodiphenylene ether; flame retardant aid such as antimony trioxide; You may mix | blend with the addition amount to express.

  In addition, polycarbonate resin has a heat resistance such as phosphorus-containing heat stabilizer, phenol-based heat stabilizer, lactone-based heat stabilizer, sulfur-based heat stabilizer, etc. in order to prevent a decrease in molecular weight and a deterioration in hue during molding. A stabilizer can be blended. Of these, phosphorus-containing heat stabilizers are preferred. Examples of the phosphorus-containing heat stabilizer include phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid, and esters thereof. Specifically, for example, triphenyl phosphite, tris (nonylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl Monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, tris (2,4-di-t-butylphenyl) phosphite, bis (2,6-di-t-butyl) -4-methylphenyl) pentaerythritol diphosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, bis (nonylphenyl) pentaerythritol diphosphite, bis (2,4- -T-butylphenyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tributyl phosphate, triethyl phosphate, trimethyl phosphate, triphenyl phosphate, diphenyl monooxoxenyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate, tetrakis (2,4-di-isopropylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,4-di-n-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,4 -Di-t-butylphenyl) -4,4'-biphenylenediphosphonite, tetrakis (2,4-di-t-butylphenyl) -4,3'-biphenylenediphosphonite, tetra (2,4-di-t-butylphenyl) -3,3′-biphenylenediphosphonite, tetrakis (2,6-di-isopropylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2, 6-di-n-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,6-di-t-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,6- Di-t-butylphenyl) -4,3′-biphenylenediphosphonite, tetrakis (2,6-di-t-butylphenyl) -3,3′-biphenylenediphosphonite, bis (2,4-di-) t-butylphenyl) -biphenylphosphonite, dimethyl benzenephosphonate, diethyl benzenephosphonate, dipropyl benzenephosphonate and the like. These phosphorus-containing heat stabilizers may be used alone or in combination of two or more. Among these phosphorus-containing heat stabilizers, tris (2,4-di-t-butylphenyl) phosphite, tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylenediphosphonite, Bis (2,4-di-t-butylphenyl) -biphenylphosphonite is particularly preferred.

  The amount of the heat stabilizer used is preferably 0.001 parts by mass or more and 0.15 parts by mass or less with respect to 100 parts by mass of the copolymerized polycarbonate resin or polycarbonate resin blend.

  Furthermore, a fatty acid ester may be blended with the polycarbonate-based resin for the purpose of improving the releasability from the mold during molding. The fatty acid ester is preferably a partial ester or a total ester of a monohydric or polyhydric alcohol having 1 to 20 carbon atoms and a saturated fatty acid having 10 to 30 carbon atoms. Examples of partial esters or total esters of monohydric or polyhydric alcohols and saturated fatty acids include stearic acid monoglyceride, stearic acid diglyceride, stearic acid triglyceride, stearic acid monosorbite, behenic acid monoglyceride, pentaerythritol monostearate, penta Erythritol tetrastearate, pentaerythritol tetrapelargonate, propylene glycol monostearate, stearyl stearate, palmityl palmitate, butyl stearate, methyl laurate, isopropyl palmitate, biphenyl biphenate, sorbitan monostearate, 2-ethylhexyl Examples include stearate. These fatty acid esters may be used alone or in combination of two or more. Of these fatty acid esters, stearic acid monoglyceride, stearic acid triglyceride, and pentaerythritol tetrastearate are particularly suitable. The amount of the fatty acid ester used is preferably 0.001 part by mass or more and 0.5 part by mass or less with respect to 100 parts by mass of the copolymer polycarbonate resin or the polycarbonate resin blend.

  A blueing agent or a fluorescent brightening agent can be blended with the polycarbonate-based resin in order to cancel the yellowishness of the daylighting building material based on the polycarbonate-based resin or the ultraviolet absorber. Any bluing agent can be used without any problem as long as it is used for polycarbonate resins. In general, anthraquinone dyes are preferred because they are readily available.

As a specific bluing agent, for example, the general name Solvent Violet 13 [CA. No (Color Index No) 60725] (for example, “Malexex (registered trademark) violet B” manufactured by LANXESS, “Diaresin (registered trademark) Blue G” manufactured by Mitsubishi Chemical Corporation, “Sumiplast (registered trademark) violet” manufactured by Sumitomo Chemical Co., Ltd. B "etc.), generic name Solvent Violet 31 [CA. No 68210] (for example, “Diaresin Violet D” manufactured by Mitsubishi Chemical Corporation), general name Solvent Violet 33 [CA. No 60725] (for example, “Diaresin Blue J” manufactured by Mitsubishi Chemical Corporation), generic name Solvent Blue 94 [CA. No 61500] (for example, “Diaresin Blue N” manufactured by Mitsubishi Chemical Corporation), generic name SolventViolet 36 [CA. No. 68210] (for example, “Macrolex Violet 3R” manufactured by LANXESS), generic name Solvent Blue97 [for example, “Macrolex Violet RR” manufactured by LANXESS, etc.] and general name Solvent Blue45 [CA. No. 61110] (for example, “Tetrazole Blue RLS” manufactured by Sand Corp.) is a representative example. These bluing agents are blended at a ratio of 2 × 10 ⁻⁴ parts by mass or less with respect to 100 parts by mass of the polycarbonate resin.

  As the fluorescent brightening agent, any conventionally known fluorescent brightening agent may be used, and is not particularly limited. For example, oxazole fluorescent brightening agent, coumarin fluorescent brightening agent, stilbene fluorescent brightening agent may be used. Examples thereof include a whitening agent, an imidazole fluorescent whitening agent, a triazole fluorescent whitening agent, a naphthalimide fluorescent whitening agent, and a rhodamine fluorescent whitening agent. These fluorescent brighteners may be used alone or in combination of two or more. Of these, oxazole fluorescent whitening agents and coumarin fluorescent whitening agents are particularly suitable. The amount of the optical brightener used is preferably 0.1 parts by mass or less, more preferably 0.05 parts by mass or less, with respect to 100 parts by mass of the polycarbonate resin. When the amount used exceeds 0.1 parts by mass, the uniformity of light may be impaired, and an expensive fluorescent whitening agent will be used more than necessary, which may increase the production cost.

  The transparent resin for the light diffusion layer may be blended with additives such as rubber for polymer alloy, thermoplastic elastomer and other polymers. What is necessary is just to adjust suitably the compounding quantity of these additives according to the kind etc., and it is not specifically limited.

  The manufacturing method of the daylighting building material of this invention is not specifically limited, Various types, such as extrusion molding, injection molding, and press molding, are employable. In order to uniformly disperse the light diffusing fine particles, a melted transparent resin may be agitated by applying a shearing force, or extrusion or injection molding that requires a shearing force during molding may be used. The shape of the plate can be changed from a general flat plate shape to a corrugated plate shape, a spherical shape, a dome shape, and the like.

  The daylighting building material of the present invention may be composed of only one light diffusion layer or may be composed of two or more layers. In this case, each layer has the same material and properties. It may be different or different. Especially, the aspect by which the light-diffusion layer and the non-light-diffusion layer were laminated | stacked one layer each or multiple layers is preferable. In this case, the matrix resin of the light diffusion layer and the non-light diffusion layer may be the same or different. Moreover, although a light-diffusion layer may be provided anywhere, it is preferable to provide in the light emission side (opposite side to the direction which sunlight injects). Most preferred is an embodiment in which an ultraviolet absorbing layer having an ultraviolet absorbing ability is formed on or on both sides of the light diffusion layer. The UV absorbing layer is provided by a coextrusion method at the same time as the formation of the light diffusing layer, using a resin composition obtained by blending a low molecular weight UV absorber with the above transparent resin, or a polymer UV absorbing agent. After the molding, it can be produced by a method such as forming by a coating method. The ultraviolet absorbing layer may be formed first, and then the light diffusion layer may be formed. Moreover, an ultraviolet absorption layer can also be provided by a method of laminating or adhering an ultraviolet absorbing film.

  As the ultraviolet absorber, any conventionally known ultraviolet absorber may be used, and is not particularly limited. For example, salicylic acid phenyl ester ultraviolet absorber, benzophenone ultraviolet absorber, triazine ultraviolet absorber, Low molecular weight UV absorbers such as benzotriazole UV absorbers, cyclic imino ester type UV absorbers, hybrid UV absorbers having both hindered phenol and hindered amine structures in the molecule, and these low molecular weight types Examples thereof include a polymer type ultraviolet absorber in which the ultraviolet absorber is suspended from a polymer (for example, Halus Hybrid (registered trademark) polymer manufactured by Nippon Shokubai Co., Ltd.). These ultraviolet absorbers may be used alone or in combination of two or more. In addition, it is preferable to use a hindered amine-based ultraviolet stabilizer in combination because it can further suppress light degradation.

  Specific examples of salicylic acid phenyl ester ultraviolet absorbers include phenyl salicylate, pt-butylphenyl salicylate, and p-octylphenyl salicylate.

  Specific examples of the benzophenone ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 2-hydroxy-4-benzyloxybenzophenone. 2-hydroxy-4-methoxy-5-sulfoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfoxytrihydridolate benzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2 ′, 4 , 4′-tetrahydroxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxy-5-sodiumsulfoxybenzophenone, bis (5-benzoyl) -4-hydroxy-2-me Kishifeniru) methane, 2-hydroxy -4-n-dodecyloxy benzophenone, 2-hydroxy-4-methoxy-2'-carboxy benzophenone.

  Specific examples of triazine-based ultraviolet absorbers include 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-hexyloxyphenol.

  Specific examples of the benzotriazole ultraviolet absorber include 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-t-octylphenyl) benzotriazole, 2- (2-hydroxy-3,5-dicumylphenyl) phenylbenzotriazole, 2- (2-hydroxy-3-t-butyl-5-methylphenyl) -5-chlorobenzotriazole, 2,2′-methylenebis [4 -(1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (2-hydroxy-3,5-di-t-butylphenyl) benzotriazole 2- (2-hydroxy-3,5-di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3 5-di-t-amylphenyl) benzotriazole, 2- (2-hydroxy-5-t-octylphenyl) benzotriazole, 2- (2-hydroxy-5-t-butylphenyl) benzotriazole, 2- (2 -Hydroxy-4-octoxyphenyl) benzotriazole, 2,2′-methylenebis (4-cumyl-6-benzotriazolephenyl), 2,2′-p-phenylenebis (1,3-benzoxazin-4-one ), 2- [2-hydroxy-3- (3,4,5,6-tetrahydrophthalimidomethyl) -5-methylphenyl] benzotriazole and the like.

  Specific examples of the cyclic imino ester type ultraviolet absorber include 2,2′-p-phenylenebis (3,1-benzoxazin-4-one), 2,2 ′-(4,4′-). And diphenylene) bis (3,1-benzoxazin-4-one) and 2,2 ′-(2,6-naphthalene) bis (3,1-benzoxazin-4-one).

  Specific examples of hindered amine ultraviolet stabilizers include bis (2,2,6,6-) tetramethyl-4-piperidyl) sebacate and bis (1,2,2,6,6-pentamethyl-4). -Piperidyl) sebacate and the like.

Specific examples of the hybrid ultraviolet absorber having both a hindered phenol structure and a hindered amine structure in the molecule include 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2. -Bis (1,2,2,6,6-pentamethyl-4-piperidyl) -n-butylmalonate, 1- [2- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl Oxy] ethyl] -4- [3- (3,5-di-t-butyl-4-
Hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidine and the like.

  These ultraviolet absorbers may be used alone or in combination of two or more. Among these ultraviolet absorbers, 2-hydroxy-4-n-octoxybenzophenone, 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-hexyloxyphenol, 2- (2-hydroxy-5-t-octylphenyl) benzotriazole, 2- (2-hydroxy-3,5-dicumylphenyl) phenylbenzotriazole, 2- (2-hydroxy-3-tert-butyl-5-methyl) Phenyl) -5-chlorobenzotriazole, 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2,2 '-P-phenylenebis (3,1-benzoxazin-4-one) is particularly preferred.

  The amount of the ultraviolet absorber used is preferably 0.5 parts by mass or more and 50 parts by mass or less, more preferably 0.8 parts by mass or more with respect to 100 parts by mass of the matrix resin constituting the ultraviolet absorbing layer containing the ultraviolet absorber. 40 parts by mass or less, more preferably 1 part by mass or more and 30 parts by mass or less. If the amount used is less than 0.5 parts by mass, the effect of preventing the influence of sunlight or the like may be small. On the contrary, when the amount used exceeds 50 parts by mass, the effect of preventing the influence of sunlight or the like may be saturated.

  The present invention will be described in more detail with reference to the following examples. However, the following examples do not limit the present invention. In the following description, “part” means “part by mass” and “%” means “mass%”. Moreover, the evaluation method of a daylighting building material is as follows.

[Total light transmittance (%)]
It measured by the method prescribed | regulated to JISK7361-1 using Nippon Denshoku Industries Co., Ltd. haze meter NDH2000. The evaluation standard of the total light transmittance was 70% or more as ◎, 60% or more and less than 70% as ○, and less than 60% as ×.

[D _50]
Using the manufactured daylighting building material, the light transmittance is automatically measured by changing the light receiving angle in increments of 5 ° with a spectral color change color difference meter (GC5000 manufactured by Nippon Denshoku Industries Co., Ltd.). The light receiving angle (D ₅₀ ) at which the light transmittance was 50% when the light transmittance at an angle of 0 ° was 100% was determined. Evaluation criteria of the D ₅₀ is more than 30 ° ◎, the less than 20 ° 30 ° ○, was × less than 20 °.

Example 1
98 parts of polycarbonate (PC) resin ("Caliber (registered trademark) 302-6": manufactured by Sumitomo Dow Co., Ltd .: refractive index: 1.59) as fine particles for light diffusion, "Eposter (registered trademark) MA-1002" (poly 2 parts of methyl methacrylate cross-linked product: average particle diameter 2 μm: refractive index 1.49: manufactured by Nippon Shokubai Co., Ltd. were supplied to an extruder, and the lighting building material was extruded at an extrusion temperature of 280 ° C. A plate-shaped daylighting building material having a thickness of 1000 μm was obtained. The evaluation results are shown in Table 1.

Example 2
For the light diffusion layer, 85 parts of the PC resin and 15 parts of “Eposter (registered trademark) MA-1004” (average particle size 4 μm: refractive index 1.49: manufactured by Nippon Shokubai Co., Ltd.) are supplied to the first extruder. did. Only the PC resin was supplied to the second extruder. A plate-shaped daylighting building material having a thickness of 1000 μm in which a light diffusion layer and a non-light diffusion layer were laminated was manufactured by a coextrusion method. The thickness of the light diffusion layer is 100 μm. The evaluation results are shown in Table 1.

Example 3
First extrusion of 83 parts of the above PC resin, 15 parts of “Eposter (registered trademark) MA-1004” and 2 parts of “TINUVIN (registered trademark) 1577” (manufactured by Ciba Japan) for the light diffusion layer Except having supplied to the machine, it carried out similarly to Example 2, and manufactured the plate-shaped daylighting building material with a thickness of 1000 micrometers in which the light-diffusion layer and the non-light-diffusion layer were laminated | stacked. The thickness of the light diffusion layer is 100 μm. The evaluation results are shown in Table 1.

Example 4
97 parts of the PC resin and 3 parts of “Eposter (registered trademark) MA-1004” are supplied to the first extruder for the light diffusion layer, and 2 UV absorbers are added to the PC resin for the non-light diffusion layer. %, A flat light-collecting building material having a thickness of 740 μm in which a light diffusing layer and an ultraviolet absorbing layer were laminated was produced in the same manner as in Example 2 except that it was added to the second extruder and supplied to the second extruder. The thickness of the light diffusion layer is 700 μm. The evaluation results are shown in Table 1.

Example 5
For the light diffusion layer, 80 parts of the PC resin and 20 parts of “Eposter (registered trademark) MA-1002” are supplied to the first extruder, and only the PC resin is supplied to the second extruder for the non-light diffusion layer. A sheet having a thickness of 1950 μm in which a light diffusing layer and a non-light diffusing layer were laminated was obtained in the same manner as in Example 2 except that it was supplied. The thickness of the light diffusion layer is 100 μm. A weather-resistant acrylic laminate film having ultraviolet absorptivity (“Acryprene (registered trademark)” manufactured by Mitsubishi Rayon Co., Ltd .: thickness 50 μm) is thermally laminated on the non-light diffusing layer side of this sheet to obtain a 2 mm thick plate-shaped daylighting property. Building materials were manufactured. The evaluation results are shown in Table 1.

Comparative Example 1
A flat lighting construction material having a thickness of 740 μm in which a light diffusion layer and a non-light diffusion layer having the same composition as in Example 2 were laminated was produced. The thickness of the light diffusion layer is 10 μm. The evaluation results are shown in Table 1.

Comparative Example 2
In Example 1, a plate-shaped daylighting building material having a thickness of 1 mm was manufactured in the same manner as in Example 1 except that 99 parts of the PC resin and 1 part of “Eposter (registered trademark) MA-1002” were used. The evaluation results are shown in Table 1.

Comparative Example 3
In the same manner as in Example 1, a plate-shaped daylighting building material having a thickness of 2 mm was produced. The evaluation results are shown in Table 1.

As is clear from Table 1, all of the daylighting building materials of the present invention had high light transmittance and light diffusivity (D ₅₀ ), and had high performance. Since Comparative Example 1 had a thin light diffusion layer, Comparative Example 2 had a low light diffusibility (D ₅₀ ) because the amount of fine particles for light diffusion was small. In Comparative Example 3, the thickness of the light diffusion layer was too thick and the total light transmittance was inferior.

  Since the daylighting building material of the present invention has good daylighting properties, for example, when used as a roofing material, sufficient brightness can be ensured even when it is cloudy or raining. Moreover, it is excellent in light diffusibility, and even if it looks directly at the sun through this lighting construction material, it is not dazzling. Accordingly, the daylighting building material of the present invention can be used as a roofing material or a side plate such as a carport, a terrace, or a veranda.

Claims (5)

  When the total light transmittance is 60% or more and the light transmittance at a light emission angle of 0 ° and a light receiving angle of 0 ° is 100%, the light receiving angle at which the light transmittance is 50% is 20 ° or more. A characteristic daylighting building material.   A light diffusing layer comprising a transparent resin and fine particles having an average particle diameter of 1 to 20 μm and a refractive index difference with the transparent resin of 0.05 or more is provided. The lighting construction material according to claim 1, wherein the light-diffusing layer has a thickness of 20 to 1200% by mass. The following formula is satisfied, wherein the thickness of the light diffusion layer is t (μm), the fine particle concentration in the light diffusion layer is c (mass%), and the average particle diameter is d (μm). Daylighting building materials.
250 ≦ (t · c) / d ≦ 2000   The daylighting building material of any one of Claims 1-3 provided with the ultraviolet absorption layer in the outermost layer. The daylighting building material according to any one of claims 2 to 4, wherein the transparent resin is polycarbonate.