JP2006199914A - Polypropylene resin composition and light transmitting molded product using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light transmitting molded product irregularly reflecting/scattering light incident on the molded product while maintaining light transmittance and eliminating irregularity of illuminance in the light transmitting molded product composed of a light transmitting polypropylene resin composition having relatively high heat-resistant temperature or chemical resistance. <P>SOLUTION: The polypropylene resin composition comprises a polypropylene resin (A), a specific inorganic filler (B), an antioxidant and a light stabilizer (C) and a stearic acid metal soap (D). In the polypropylene resin composition, the specific inorganic filler (B) is one or more kinds of inorganic fillers selected from barium sulfate, zinc sulfide, zinc oxide and titanium oxide having ≤5 μm average particle diameter and is contained in an amount of 0.003-1.5 mass% based on the total amount of the polypropylene resin composition. The stearic acid metal soap (D) contains at least two kinds selected from magnesium stearate, calcium stearate and zinc stearate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polypropylene resin composition suitable for obtaining a light-transmitting molded article used for a cover or a light display plate of a lighting device provided in various electric devices and various vehicles, and a light-transmitting molding using the same. It is about goods.

  Conventionally, as a light-transmitting molded product used for lighting devices and the like provided in various electric devices and various vehicles, (meth) acrylic resin (PMMA), acrylonitrile / styrene resin (AS), polycarbonate resin (PC) ), And molding materials such as polypropylene resin (PP) are used.

  A light-transmitting molded article made of a resin composition containing PMMA or AS as a resin component has a low heat-resistant temperature and can usually be used continuously only in an environment of about 60 ° C. or less.

  Further, a light-transmitting molded article made of a resin composition containing PMMA, AS, and PC as resin components has a drawback that chemical resistance is low.

  On the other hand, a light-transmitting molded article made of a resin composition comprising a polypropylene resin as a resin component has a relatively high heat-resistant temperature and chemical resistance, so that the application requires heat and chemical resistance, for example, lighting in an automobile interior. It is used as a cover part for lighting and a cover part for lighting provided in a trunk door or the like.

  However, a light-transmitting molded article using a polypropylene resin composition has a problem that it easily undergoes discoloration or corrosion deterioration due to light or heat. For example, when ultraviolet rays were irradiated for 60 days at a temperature of 90 ° C., the molded product was greatly discolored, and the shape could not be maintained due to corrosion deterioration. Various measures have been adopted for this problem (see, for example, Patent Documents 1, 2, and 3), but at present, sufficient effects have not been obtained.

Furthermore, in any of the above light-transmitting molded products, when used as a cover for a lighting device or the like, there is a problem that non-uniform illuminance occurs, which is relatively bright just under the light source and dark at the periphery. It was. In order to solve this problem, conventionally, a method has been adopted in which light is irregularly reflected / scattered by providing a fine texture or uneven shape on the surface of a light-transmitting molded product.
Japanese Patent No. 2730165 Japanese Patent No. 2661164 JP-A-8-311274

  The present invention is a light-transmitting molded article comprising a light-transmitting polypropylene resin composition having a relatively high heat resistance temperature and chemical resistance, and discoloration due to light and heat by dispersing an antioxidant and a light stabilizer well. Corrosion degradation is suppressed, and by mixing specific inorganic fillers at a specific ratio, light incident on the molded product is diffused and scattered while maintaining light transmission, eliminating uneven illumination. It is an object to provide a light-transmitting molded product that can be produced.

  The polypropylene resin composition of the present invention is a polypropylene resin composition containing a polypropylene resin (A), an inorganic filler (B), an antioxidant and a light stabilizer (C), and a metal stearate soap (D). The inorganic filler (B) is one or more inorganic fillers selected from barium sulfate, zinc sulfide, zinc oxide, and titanium oxide having an average particle size of 5 μm or less, and is 0.003 based on the total amount of the polypropylene resin composition. The metal stearate soap (D) contains at least two selected from magnesium stearate, calcium stearate and zinc stearate (claim 1). .

  The antioxidant preferably contains a phenolic antioxidant and a phosphorus antioxidant (claim 2).

  The light stabilizer preferably contains a hindered amine light stabilizer and / or a benzotriazole ultraviolet absorber.

  The inorganic filler is preferably surface-coated with one or more selected from alumina, silica, polyhydric alcohol, or stearic acid.

  Moreover, it is a light-transmitting molded article obtained by using the polypropylene resin composition (Claim 5).

  Moreover, it is a light-transmitting molded product having a surface roughness (Ra) of the light-transmitting surface of less than 100 μm (Claim 6).

  The polypropylene resin composition of the present invention is a polypropylene resin, one or more inorganic fillers selected from barium sulfate, zinc sulfide, zinc oxide and titanium oxide having an average particle size of 5 μm or less, an antioxidant and a light stabilizer, stearin In the polypropylene resin composition containing an acid metal soap, the inorganic filler is contained in an amount of 0.003 to 1.5% by mass, and the metal stearate soap is at least selected from magnesium stearate, calcium stearate, and zinc stearate. It is characterized by containing two types, and by mixing the inorganic filler at a specific ratio, the light incident on the molded product is irregularly reflected and scattered while maintaining the light transmittance, and the illuminance is uneven. In addition, by using two or more kinds of the metal stearate soap together, Inorganic fillers, antioxidants and light stabilizers goodness distributed to it can (claim 1).

  Moreover, since the said antioxidant contains a phenolic antioxidant and phosphorus antioxidant, the corrosion deterioration by oxidation can be suppressed efficiently (Claim 2).

  Further, since the light stabilizer contains a hindered amine light stabilizer and / or a benzotriazole ultraviolet absorber, discoloration due to light or heat can be efficiently suppressed (claim 3).

  In addition, when the inorganic filler is surface-coated with one or more selected from alumina, silica, polyhydric alcohol, or stearic acid, sodium ions are precipitated from the inorganic filler and the inorganic filler acts as a photocatalyst. Can be suppressed, and discoloration and corrosion deterioration due to light and heat of the molded product can be further reduced.

  In addition, the light-transmitting molded product obtained by using the polypropylene-based resin composition diffuses and scatters light incident on the molded product while maintaining the light transmitting property, and can eliminate unevenness in illuminance. It is a light-transmitting molded article that is suitably used for lighting devices and the like provided in electrical equipment and various vehicles.

  Moreover, in the light-transmitting molded product obtained using the polypropylene resin composition, even if the surface roughness (Ra) of the light transmitting surface is less than 100 μm, the light incident on the molded product is irregularly reflected and scattered. Further, the non-uniformity of illuminance can be eliminated, and a light-transmitting molded product that makes the illuminance uniform can be obtained without applying special embossing or uneven shape to the mold (claim 6).

  The polypropylene resin composition of the present invention is a polypropylene resin composition containing a polypropylene resin (A), an inorganic filler (B), an antioxidant and a light stabilizer (C), and a metal stearate soap (D). The inorganic filler (B) is one or more inorganic fillers selected from barium sulfate, zinc sulfide, zinc oxide, and titanium oxide having an average particle size of 5 μm or less, and is 0.003 based on the total amount of the polypropylene resin composition. The metal stearate soap (D) contains at least two selected from magnesium stearate, calcium stearate and zinc stearate.

  The polypropylene-based resin (A) is a resin obtained by polymerizing a monomer having propylene as a main component. In addition to a homopolymer of propylene, an ethylene copolymer obtained by copolymerizing a small amount of ethylene is known. The light transmissive polypropylene resin is used. Note that only one type of polypropylene resin (A) may be used alone, or two or more types having different melt viscosities or different copolymerization components may be used in combination.

  The inorganic filler (B) in the present invention is selected from barium sulfate, zinc sulfide, zinc oxide, and titanium oxide having an average particle size of 5 μm or less. Light that is a cover when used as a cover for a lighting fixture or the like in order to diffusely reflect and diffuse visible light incident on a molded product while maintaining the light transmittance of the polypropylene resin (A) by using the inorganic filler. Good light diffusibility can be obtained even if the surface of the transmissive molded product is not provided with a shape for irregular reflection such as a textured shape or an uneven shape. Among the inorganic fillers, barium sulfate is particularly preferable. In addition, the said inorganic filler may be used independently or may be used in combination of 2 or more type.

  The average particle size of the inorganic filler (B) is 5 μm or less. When the average particle diameter exceeds 5 μm, the transmittance of visible light incident on the molded article may be lowered, and further, the dispersibility may be lowered and uniform mixing may not be possible. Further, the lower limit of the average particle diameter is about 0.2 μm, and when the average particle diameter is less than 0.2 μm, the particles are aggregated and cannot be uniformly and finely dispersed, and the transmittance of visible light incident on the molded product is reduced. It may be difficult to diffuse and diffuse while maintaining.

  As the inorganic filler, for example, when a highly cohesive filler such as talc is used, it is not possible to form a light colored molded product such as translucent, and the dispersibility is low and the aggregate Therefore, it is not preferable to use it as an inorganic filler.

  As the inorganic filler (B), it is preferable to use a material whose surface is coated by an inorganic coating treatment such as alumina / silica coating or an organic coating treatment such as polyhydric alcohol coating or stearic acid coating. By using a surface-coated inorganic filler, elution of ions and metal components contained in the inorganic filler into the polypropylene resin, specifically, for example, in the case of barium sulfate, sodium ions into the polypropylene resin Elution and the like, and the promotion of discoloration and deterioration can be suppressed. Further, when the inorganic filler is zinc sulfide, zinc oxide, or titanium oxide, the photocatalytic action of the inorganic filler can be suppressed, and discoloration or deterioration of polypropylene can be suppressed.

  In the polypropylene resin composition of the present invention, the blending ratio of the inorganic filler (B) is 0.003 to 1.5 mass% with respect to the total amount of the polypropylene resin composition.

  When the blending ratio is less than 0.003 mass%, it becomes difficult to sufficiently diffuse and diffuse visible light incident on the molded product, and when it exceeds 1.5 mass%, transmission of incident visible light is difficult. It is difficult to sufficiently maintain the property, and when the blending ratio of the inorganic filler is too large, the polypropylene resin tends to be discolored or deteriorated due to elution of ions or the photocatalytic effect.

  In addition, the translucency of the light transmissive molded article obtained from the polypropylene resin composition of the present invention can be appropriately adjusted according to the type, average particle diameter, and blending amount of the inorganic filler (B). For example, when using barium sulfate, it is preferable to mix 0.1 to 1.5% by mass with respect to the total amount of the polypropylene resin composition. When using zinc sulfide or zinc oxide, the mixing ratio is 0.005 to 0.120% by mass is preferable. Further, when titanium oxide is used, the blending ratio of 0.003 to 0.1% by mass may cause discoloration / deterioration of the polypropylene resin. It is preferable from the viewpoint of being small and ensuring a predetermined light transmittance.

  The antioxidant used in the present invention is not particularly limited, but containing a phenolic antioxidant and a phosphorus antioxidant suppresses the oxidation of the polypropylene resin, and further, other components blended at the same time, For example, it is preferable from the viewpoint of suppressing oxidative deterioration of a hindered amine light stabilizer or a benzotriazole ultraviolet absorber.

  Examples of phenolic antioxidants include both hindered types having a 2,6-di-t-butylphenol skeleton (specifically, Irganox 1010 and Irganox 1076 manufactured by Ciba Geigy Japan, Inc.) One-hindered type having a 2,6-di-t-butylphenol skeleton (specifically, Irganox 245 manufactured by Nippon Ciba-Geigy Co., Ltd., or Sumilizer GA80 manufactured by Sumitomo Chemical Co., Ltd.). it can. These may be used alone or in combination of two or more.

  Examples of phosphorus antioxidants include ADK STAB PEP manufactured by Asahi Denka Kogyo Co., Ltd., which contains cyclic neopentanetetraylbis (2,6-di-t-butyl-4-methylphenyl) phosphite as a component. -36 and HP-10 manufactured by Asahi Denka Kogyo Co., Ltd. containing 2,2′methylenebis (4,6-di-butylphenyl) octyl phosphite as a component. These may be used alone or in combination of two or more.

  In the polypropylene resin composition of the present invention, the blending ratio of the antioxidant is preferably 0.2 to 0.5 mass% with respect to the total amount of the polypropylene resin composition. If the blending ratio of the antioxidant is less than 0.2% by mass, discoloration and corrosion deterioration of the transparent molded product may not be sufficiently suppressed. On the contrary, there is a risk that it will be economically disadvantageous.

  Although it does not specifically limit as a light stabilizer used in this invention, A hindered amine type light stabilizer and / or a benzotriazole type ultraviolet absorber are preferable from the point which suppresses the photodegradation of a polypropylene resin effectively.

As the hindered amine light stabilizer, a low molecular type (for example, bis (2,2,6,
6-tetramethyl-4-piperidyl) sebacate as a component Sanol LS-770 manufactured by Sankyo Kasei Kogyo Co., Ltd. ), Kumaso soap 944 “Biosoap 04” manufactured by Kyodo Yakuhin Co., Ltd., and the like. These may be used alone or in combination of two or more.

  It is preferable to blend a benzotriazole ultraviolet absorber. Examples of the benzotriazole ultraviolet absorber include 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole and 2- (3,5-di-t-amyl-2). Various types such as -hydroxyphenyl) benzotriazole can be used, but specific product names include those of low molecular weight (LA36 manufactured by Asahi Denka Kogyo Co., Ltd., Tinuvin manufactured by Nippon Ciba-Geigy Co., Ltd.) 326, Biosoap 591 manufactured by Kyodo Yakuhin Co., Ltd., Tinuvin 328 manufactured by Nippon Ciba-Geigy Co., Ltd.) and polymer type (LA31 manufactured by Asahi Denka Kogyo Co., Ltd.), Tinuvin 234 manufactured by Nippon Ciba-Geigy Co., Ltd. Etc.). These may be used alone or in combination of two or more.

  In the polypropylene resin composition of the present invention, the blending ratio of the light stabilizer is preferably 0.1 to 1.0% by mass with respect to the total amount of the polypropylene resin composition. When the blending ratio of the light stabilizer is less than 0.1% by mass, discoloration and deterioration due to light of the light-transmitting molded product cannot be sufficiently suppressed, and even if blended in a large amount, further improvement of the effect cannot be obtained. There is a risk of economic disadvantage.

  In the present invention, in order to increase the dispersibility of the inorganic filler (B), the antioxidant and the light stabilizer (C) in the polypropylene resin (A), from magnesium stearate, calcium stearate and zinc stearate. Contains metal stearate soap (D) containing at least two selected.

  These components are components that enhance the dispersibility of the inorganic filler (B), the antioxidant, and the light stabilizer (C) in the polyolefin.

  Moreover, as a combination of a metal stearate soap, it is preferable to use together with magnesium stearate and calcium stearate from the point which raises the light transmittance by improving the dispersibility of an inorganic filler (B) more. Further, when zinc stearate is used in combination, the dispersibility of the inorganic filler (B), antioxidant and light stabilizer (C) in the polypropylene resin (A) can be further enhanced.

  That is, for example, in the inorganic filler (B), by adding 0.003 to 1.5% by mass with respect to the total amount of the polypropylene resin composition, the obtained light transmissive molded article maintains a sufficient light transmissive property. Irradiance unevenness can be eliminated by irregularly reflecting and scattering light incident on the molded product. In addition, in the antioxidant and the light stabilizer (C), due to its good dispersibility, it is possible to effectively suppress discoloration / deterioration due to light and heat, and to obtain a light-transmitting molded article excellent in light resistance and the like. It can be done.

  The blending ratio of the stearic acid metal soap (D) is preferably 0.01 to 0.3% by mass with respect to the total amount of the polypropylene resin composition. If the proportion is less than 0.01% by mass, the various components cannot be sufficiently uniformly dispersed in the light-transmitting molded product, and the above effects tend not to be sufficiently obtained. Further improvement of the effect cannot be obtained, and there is a risk that it will be economically disadvantageous.

  In the present invention, a plurality of types of metal stearate soap are used in combination as the metal stearate soap, but the blending ratio of each metal stearate soap is arbitrary, and for example, an equal amount can be blended.

  And the polypropylene resin composition of this invention mix | blends the said various components, this is uniformly mixed with a mixer, a blender, etc., and also heat-kneaded with a biaxial or single screw extrusion kneader etc., and pelletized etc. It is obtained by granulating.

  The obtained polypropylene resin composition is molded into a desired shape by a known resin molding method, specifically, for example, an injection molding method, a compression molding method, an extrusion molding method, etc. can get. The molding conditions are appropriately selected according to various molding methods so that a desired shape can be obtained.

  In addition, the light-transmitting molded article of the present invention is a molded article having a thickness of 2.5 mm, for example, and has a light transmittance of about 10 to 70%.

  In the molding die used to obtain the light-transmitting molded product of the present invention, the conventional illumination is used to diffusely reflect the visible light incident from the light source on the molded product to the cavity surface of the mold and diffuse the emitted light. As with the cover of the device, the surface of the light transmission surface may be subjected to various irregularities, sandy, rocky, geometric patterns, etc., but the polypropylene resin of the present invention When using the composition, the visible light is irregularly reflected by the inorganic filler contained in the polypropylene resin composition of the present invention in a molded product obtained by a mold having a relatively smooth surface without performing the processing. The emitted light can be diffused. Therefore, it is possible to reduce the manufacturing cost of a mold used for a light-transmitting cover or the like used for a lighting device or the like.

  Further, the surface roughness is not particularly limited, but the light-transmitting molded product obtained by using the polypropylene resin composition of the present invention has a light-transmitting surface on its surface like a conventional light-transmitting cover. The surface of the light-transmitting surface does not require irregularities, various kinds of graining such as sand, rocks, geometric patterns, etc., so that the surface roughness (Ra) of the light transmission surface is less than 100 μm, and even smooth such as less than 50 μm. Even in such a case, the visible light can be sufficiently diffused and diffused, and the emitted light can be diffused, and the illuminance can be made uniform.

  In addition, when a spotlight function is imparted to the light-transmitting molded product of the present invention, such as an automobile interior lamp cover, the spot illumination function can be imparted by making the thickness of the spot portion thinner than the periphery thereof. . The thickness is preferably about 0.3 to 1.5 mm at the spot portion, and its peripheral portion is preferably about twice as thick as the spot portion.

  The light-transmitting molded article of the present invention is used for various lighting fixture parts. Specifically, for example, covers for housing lighting equipment, main bodies, other various parts, automotive interior lighting parts, covers for lighting equipment such as trunks and doors, main bodies, various other parts, diffusion plates in automobile meters, It is suitably used for a cover of a display device for various other machine parts. In particular, since the light-transmitting molded product of the present invention is excellent in heat resistance, chemical resistance, and weather resistance as well as the light diffusibility, it is effective when used in ultraviolet rays, high-temperature environments and automobile interior parts. .

  In addition, the light source of the said lighting fixture is not specifically limited, For example, the light source which emits light with a wavelength of about 250-1000 nm, such as a mercury lamp, an incandescent lamp, a fluorescent lamp, LED, a halogen lamp, is used suitably.

  Hereinafter, the present invention will be described specifically by way of examples.

  The raw materials used in this example are summarized below.

Polypropylene A: Polypropylene resin “J107W” manufactured by Grand Polymer Co., Ltd.
Polypropylene B: Polypropylene resin “J707” manufactured by Grand Polymer Co., Ltd.
Polycarbonate: “H3000” manufactured by Mitsubishi Engineering Plastics Co., Ltd.
PMMA resin: “IRH50” manufactured by Mitsubishi Rayon Co., Ltd.
AS resin: “SAN-C” manufactured by Techno Polymer Co., Ltd.
PEN resin: “TN8065S” manufactured by Teijin Chemicals Ltd.
Barium sulfate A: Barium sulfate with an average particle size of 5 μm (“300” manufactured by Sakai Chemical Co., Ltd.)
Barium sulfate B: Barium sulfate with an average particle diameter of 8 μm Surface coated barium sulfate: Barium sulfate with an average particle diameter of 3 μm whose surface is coated with silica and alumina (“B-34” manufactured by Sakai Chemical Co., Ltd.)
Zinc sulfide: Zinc sulfide with an average particle size of 2 μm (Sactris)
Zinc oxide: Ultrafine zinc oxide with an average particle diameter of 1 μm (manufactured by Sakai Chemical Co., Ltd.)
Titanium oxide: Titanium oxide with an average particle diameter of 2 μm (“R680” manufactured by Ishihara Sangyo Co., Ltd.)
Talcphenol-based antioxidant: “Irganox 1010” manufactured by Ciba Geigy Japan
Phosphorous antioxidant: “PEP-36” manufactured by Asahi Denka Co., Ltd.
Hindered amine light stabilizer: “Biosoap 04” manufactured by Kyodo Yakuhin Co., Ltd.
Benzotriazole UV absorber: “Tinubin 326” manufactured by Ciba Geigy Japan

(Examples 1-9 and Comparative Examples 1-10)
After blending each component at the blending ratio shown in Table 1 and Table 2, mixing for 30 minutes with a blender and homogenizing, melt-kneading with a twin-screw extruder set at a cylinder temperature of 220 ° C., cooling, pelletizing, and polypropylene A system resin composition was obtained. The following evaluation was performed using the obtained polypropylene resin composition.
(Tensile elongation test)
In accordance with ASTM D638, a dumbbell specimen having a thickness of 3 mm was formed by injection molding. The resulting dumbbell test piece was measured for elongation at break using a tensile tester.
(Light tensile elongation test)
A dumbbell test piece similar to the tensile elongation test was irradiated with ultraviolet rays for 30 days under a 120 ° C. atmosphere using a mercury lamp, and then the elongation at break was measured and calculated in the same manner as in the tensile elongation test.
(Light discoloration resistance test)
A 3 mm-thick 50 mmφ disk specimen was molded, and the color change after irradiation with a mercury lamp for 30 days in an atmosphere of 120 ° C. was measured with a color difference meter to calculate ΔE.
(Heat-resistant discoloration test)
A 50 mmφ disk specimen having a thickness of 3 mm was molded, and the color change after standing for 30 days in an atmosphere of 120 ° C. was measured with a color difference meter to calculate ΔE.
(Light-proof crack occurrence time)
A disc test piece having a thickness of 3 mm and a diameter of 50 mmφ was molded, and the time until the occurrence of cracks was measured when ultraviolet rays were irradiated with a mercury lamp in an atmosphere of 120 ° C.

(Light diffusion test)
An illumination cover, which is a box-shaped light-transmitting molded product having a thickness of 2 mm, a bottom surface of 60 × 60 mm, and a height of 20 mm, was molded by injection molding using the obtained resin composition. Note that the mold surface used in the molding is smooth.

  Next, as shown in FIG. 1, a 1A light bulb is fixed to a white top plate and covered with the molded product, and the illumination is perpendicular to the molded product when the light bulb is turned on and in the direction of 30 degrees below the top plate. The illuminance was measured with an illuminometer, and the ratio of the illuminance in the downward 30 degree direction to the case where the illuminance in the vertical direction was taken as 100% (hereinafter referred to as the illuminance ratio in the downward 30 degree direction) was measured.

  The obtained results are shown in Tables 1 and 2.

(Comparative Examples 11-20)
Using each of the resins listed in Table 3, the same shape as in Examples 1 to 9 and Comparative Examples 1 to 10, and a light-transmitting molded product having a texture of 100 μm deep on its inner surface, and A light-transmitting molded product having a depth of 500 μm and having 45-degree ridges and depressions on the surface was molded. In addition, the shape of the said surface was obtained by surface-treating in the cavity of the metal mold | die similar to the metal mold | die used in Examples 1-9 and Comparative Examples 1-10.

  And illumination intensity was evaluated like Examples 1-9 and Comparative Examples 1-10. The results are shown in Table 3.

  In Example 6 in which the light-transmitting molded product of the present invention was used as an illumination cover from Table 3, even in the case of a molded product having a smooth surface shape that does not provide a surface shape for diffusing light on the surface, the illuminance below 30 degrees The percentage was 63%.

  On the other hand, even in the case of a light-transmitting molded product formed by molding a material that has been used for a cover of a conventional lighting device or the like, the inner surface thereof is subjected to a textured process or a mountain-shaped uneven process for the purpose of diffusing light. The illuminance ratio in the downward 30-degree direction was about 17 to 38%.

  From the above results, it can be seen that the light diffusibility of the light transmissive molded product of the present invention is significantly superior to the conventional light transmissive molded product.

It is a schematic diagram which shows the shape of the light transmissive molded article used in the Example.

Explanation of symbols

1 1A bulb 2 Light-transmitting molded product 3 Top plate

Claims (6)

In a polypropylene resin composition containing a polypropylene resin (A), an inorganic filler (B), an antioxidant and a light stabilizer (C), and a metal stearate soap (D),
The inorganic filler (B) is one or more inorganic fillers selected from barium sulfate, zinc sulfide, zinc oxide, and titanium oxide having an average particle size of 5 μm or less, and is 0.003 to the total amount of the polypropylene resin composition. Containing 1.5% by weight,
The metal stearate soap (D) contains at least two kinds selected from magnesium stearate, calcium stearate and zinc stearate.   The polypropylene resin composition according to claim 1, wherein the antioxidant contains a phenolic antioxidant and a phosphorus antioxidant.   The polypropylene resin composition according to claim 1 or 2, wherein the light stabilizer contains a hindered amine light stabilizer and / or a benzotriazole ultraviolet absorber.   The polypropylene resin composition according to any one of claims 1 to 3, wherein the inorganic filler (B) is surface-coated with one or more selected from alumina, silica, polyhydric alcohol, or stearic acid.   The light-transmitting molded article obtained using the polypropylene-type resin composition of any one of Claims 1-4.   The light transmissive molded article according to claim 5, wherein the light transmissive surface has a surface roughness (Ra) of less than 100 μm.

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