JP6140484B2 - Unsaturated polyester resin composition for lamp reflector and molded product thereof, and lamp reflector - Google Patents

Description

  The present invention relates to a lamp reflector used for various lamps such as a headlamp and a fog lamp of a vehicle, an unsaturated polyester resin composition for a lamp reflector used for manufacturing the lamp reflector, and a molded product thereof.

  The unsaturated polyester resin composition (bulk molding compound: BMC) containing an unsaturated polyester resin, an inorganic filler and a fiber reinforcement has excellent properties (for example, mechanical strength, rigidity, surface smoothness, dimensional accuracy, heat resistance). Due to its properties and formability, it is widely used in various applications such as chassis for office automation equipment and office equipment, and lamp reflectors represented by headlamps.

However, the conventional unsaturated polyester resin composition can obtain a molding excellent in mechanical strength, rigidity, surface smoothness, dimensional accuracy and heat resistance by curing molding, while retaining these excellent characteristics. For this reason, it is necessary to increase the contents of the inorganic filler and the fiber reinforcing material, resulting in an increase in the specific gravity of the molded product. Further, in general, unsaturated polyester resins give a molded product having a higher specific gravity than thermoplastic resins, and thus the range of use has been limited so far.
In order to solve this problem, various methods for reducing the specific gravity have been developed. As a typical method, there is a method of reducing the content of an inorganic filler or a fiber reinforcing material and adding a hollow filler such as a glass balloon or a silica balloon (see, for example, Patent Documents 1 and 2).

  By the way, the lamp is composed of various parts, and the lamp reflector, which is one of the parts, uses other parts (for example, a part for fixing the lamp reflector, a part for fixing the bulb, a light, etc.) using a self-tapping screw. The hood is adjusted and fastened. In particular, the lamp reflector is an important component for irradiating light from a light source in a predetermined direction, and it is necessary to fix the lamp reflector at a predetermined position in order to suppress a deviation in the irradiation direction.

Japanese Patent Laid-Open No. 2001-261554 Japanese Patent No. 4404539

  However, although the unsaturated polyester resin composition obtained by a conventional method gives a molded product having a low specific gravity, the self-tap strength of the molded product is not sufficient. Therefore, when this molded product is used as the base material of the lamp reflector, the self-tap portion is destroyed when the lamp is assembled or used, and the lamp reflector cannot be fixed. As a result, it becomes difficult to determine the irradiation direction of the lamp, and a basic function as a lamp reflector that irradiates light from a light source in a predetermined direction cannot be stably obtained.

The present invention has been made to solve the above-described problems, and maintains the conventional characteristics (surface smoothness, mechanical strength, dimensional accuracy, and formability), while reducing the specific gravity and self-tapping strength. It aims at providing the unsaturated polyester resin composition for lamp reflectors which gives the molding which achieved coexistence with improvement of.
In addition, the present invention provides a molded article that achieves both low specific gravity and improved self-tap strength while maintaining conventional characteristics (surface smoothness, mechanical strength, dimensional accuracy, and moldability). With the goal.
Furthermore, an object of this invention is to provide the lamp reflector which can suppress the shift | offset | difference of an irradiation direction.

As a result of diligent research to solve the above problems, the present inventors have resulted in a decrease in self-tap strength due to the blending of the hollow filler, and by treating the hollow filler with a silane coupling agent, It has been found that the balance between the lowering of the specific gravity and the improvement of the self-tap strength can be improved by increasing the adhesiveness with the resin component to improve the self-tap strength and specifying the blending amount of the hollow filler. It came to be completed.
That is, this invention is the following [1]-[ 5 ].

[1] An unsaturated polyester resin composition for a lamp reflector including an unsaturated polyester, a crosslinking agent, an inorganic filler, a hollow filler and a fiber reinforcing material, wherein the hollow filler is subjected to a surface treatment with a silane coupling agent. And the content of the hollow filler in the unsaturated polyester resin composition for a lamp reflector is 15 to 22% by mass, the unsaturated polyester resin composition for a lamp reflector .

[2] The silane coupling agent is at least one selected from the group consisting of a methacrylic silane coupling agent, a styryl silane coupling agent, a vinyl silane coupling agent, and an acrylic silane coupling agent. The unsaturated polyester resin composition for lamp reflectors according to [1] .
[3] The unsaturated polyester resin composition for lamp reflectors according to [1] or [2] , wherein a molded product having a self-tap strength of 1.7 N · m or more is provided.

[4] A molded product, which is a molded and cured body of the unsaturated polyester resin composition for lamp reflectors according to any one of [1] to [3] .
[5] A lamp reflector having the molded product of [4] as a base material.

According to the present invention, a lamp reflector that provides a molded product that achieves both low specific gravity and improved self-tap strength while maintaining conventional characteristics (surface smoothness, mechanical strength, dimensional accuracy, and moldability). An unsaturated polyester resin composition can be provided.
In addition, according to the present invention, a molded product that achieves both low specific gravity and improved self-tap strength while maintaining conventional characteristics (surface smoothness, mechanical strength, dimensional accuracy, and moldability) is provided. can do.
Furthermore, according to this invention, the lamp reflector which can suppress the shift | offset | difference of an irradiation direction can be provided.

The unsaturated polyester resin composition for lamp reflectors of the present invention (hereinafter abbreviated as “unsaturated polyester resin composition”) includes an unsaturated polyester, a crosslinking agent, an inorganic filler, a hollow filler, and a fiber reinforcement. Hereinafter, each component will be described.
It does not specifically limit as unsaturated polyester used for this invention, A well-known thing can be used in the said technical field. An unsaturated polyester is generally a compound obtained by polycondensation (esterification) of a polyhydric alcohol with an unsaturated polybasic acid or a saturated polybasic acid, and is appropriately selected and used according to desired properties. That's fine.

Although the weight average molecular weight (MW) of unsaturated polyester is not specifically limited, Preferably it is 5,000-20,000. In the present specification, “weight average molecular weight” is measured at normal temperature using gel permeation chromatography (Shodex GPC-101, Showa Denko KK) at the following conditions, and obtained using a standard polystyrene calibration curve. Means the value.
Column: Showa Denko LF-804
Column temperature: 40 ° C
Sample: 0.2% by mass tetrahydrofuran solution of copolymer Flow rate: 1 mL / min Eluent: Tetrahydrofuran Detector: RI-71S

  It does not specifically limit as polyhydric alcohol used for the synthesis | combination of unsaturated polyester, A well-known thing can be used. Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, neopentyl glycol, butanediol, diethylene glycol, dipropylene glycol, triethylene glycol, pentanediol, hexanediol, hydrogenated bisphenol A, bisphenol A, and glycerin. . Among these, propylene glycol, neopentyl glycol, and bisphenol A or hydrogenated bisphenol A are preferable from the viewpoints of heat resistance, mechanical strength, and moldability. These polyhydric alcohols can be used alone or in combination.

It does not specifically limit as an unsaturated polybasic acid used for the synthesis | combination of unsaturated polyester, A well-known thing can be used. Examples of unsaturated polybasic acids include maleic anhydride, fumaric acid, citraconic acid, itaconic acid and the like. These can be used alone or in combination.
It does not specifically limit as a saturated polybasic acid used for the synthesis | combination of unsaturated polyester, A well-known thing can be used. Examples of saturated polybasic acids include phthalic anhydride, isophthalic acid, terephthalic acid, het acid, succinic acid, adipic acid, sebacic acid, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, endomethylenetetrahydrophthalic anhydride, etc. Can be mentioned. These can be used alone or in combination.
Among these, from the viewpoints of heat resistance, mechanical strength, moldability, and the like, unsaturated polybasic acids are preferable, and maleic anhydride and fumaric acid are more preferable.

  Unsaturated polyester is compoundable by a well-known method using the above raw materials. Various conditions in this synthesis need to be set as appropriate according to the raw material used and the amount thereof, but in general, in an inert gas stream such as nitrogen, at a temperature of 140 to 230 ° C. under pressure or reduced pressure. Can be esterified. In this esterification reaction, an esterification catalyst can be used as needed. Examples of the catalyst include known catalysts such as manganese acetate, dibutyltin oxide, stannous oxalate, zinc acetate, and cobalt acetate. These can be used alone or in combination.

The crosslinking agent used in the present invention is not particularly limited as long as it has a polymerizable double bond polymerizable with an unsaturated polyester, and those known in the technical field can be used. Examples of the crosslinking agent include styrene monomer, diallyl phthalate monomer, diallyl phthalate prepolymer, methyl methacrylate, triallyl isocyanurate and the like.
The blending amount of the cross-linking agent is not particularly limited, but from the viewpoint of workability, polymerizability, shrinkage of the molded product, and the degree of freedom in adjusting the amount, the total amount of unsaturated polyester and cross-linking agent is preferably 100 parts by mass. It is 25-70 mass parts, More preferably, it is 35-65 mass parts.

  Although it does not specifically limit as an inorganic filler used for this invention, It is a thing other than the below-mentioned hollow filler, and a well-known thing can be used in the said technical field. Examples of the inorganic filler include calcium carbonate, aluminum hydroxide, wollastonite, clay, talc, mica, silicic anhydride and the like. Among these, calcium carbonate is preferable from the viewpoint of surface smoothness and heat resistance.

The average particle diameter of the inorganic filler is not particularly limited, but is preferably 0.5 μm or more. When the average particle size of the inorganic filler is less than 0.5 μm, the viscosity of the unsaturated polyester resin composition is increased and the moldability is reduced, or the hollow filler is destroyed and the specific gravity of the molded product is increased. There is.
The average particle diameter of the inorganic filler is more preferably 0.7 μm or more from the viewpoint of moldability. On the other hand, the average particle diameter of the inorganic filler is preferably 15 μm or less, more preferably 10 μm or less, from the viewpoint of surface smoothness and mechanical properties of the molded product. If the average particle size of the inorganic filler exceeds 15 μm, the surface smoothness and mechanical strength of the molded product may be significantly reduced, or the fluidity of the unsaturated polyester resin composition may be reduced, resulting in poor moldability. is there.
Here, the “average particle diameter” of the inorganic filler in the present specification means the particle diameter obtained by calculation from the specific surface area obtained by the air permeation method.
Average particle diameter = (6 × 10000) / (true specific gravity × specific surface area)

  Although the compounding quantity of an inorganic filler is not specifically limited, Preferably it is 40-250 mass parts with respect to a total of 100 mass parts of unsaturated polyester and a crosslinking agent, More preferably, it is 50-200 mass parts. If the blending amount of the inorganic filler is less than 40 parts by mass, the moldability deteriorates, the nest and the fiber reinforcing material float on the molded product, and sufficient surface smoothness cannot be obtained, or the mechanical strength May be significantly reduced. When the compounding quantity of an inorganic filler exceeds 250 mass parts, the specific gravity of a molded article will become high.

The hollow filler used in the present invention needs to be subjected to a surface treatment in order to enhance the adhesion with the resin component (unsaturated polyester and crosslinking agent). Since the hollow filler is generally spherical with a smooth surface, if the surface treatment is not performed, the adhesiveness between the resin component and the hollow filler is weakened, so that the desired self-tap strength cannot be obtained.
It does not specifically limit as a hollow filler, A well-known thing can be used in the said technical field. Examples of the hollow filler include a glass balloon, a silica balloon, and an alumina balloon.
Although the average particle diameter of a hollow filler is not specifically limited, Preferably it is 30 micrometers or less. Here, the “average particle size” of the hollow filler in the present specification means the particle size in the particle size distribution obtained by the laser diffraction / scattering method.

The pressure strength of the hollow filler is not particularly limited, but is preferably 55 MPa or more. When the pressure strength is less than 55 MPa, the mechanical strength decreases, the hollow filler may be destroyed during the production and molding of the unsaturated polyester resin composition, and the specific gravity of the molded product may increase.
Here, in this specification, the “pressure strength of the hollow filler” refers to the pressure at which 90 vol% of the hollow filler remains without being destroyed when pressure is applied to the hollow filler based on ASTM D-3102. means.

  The specific gravity of the hollow filler is not particularly limited, but is preferably 0.3 to 0.7. When the specific gravity of the hollow filler is less than 0.3, the pressure resistance of the hollow filler is often insufficient, the hollow filler is destroyed during the production and molding of the unsaturated polyester resin composition, and the specific gravity of the molded product increases. Sometimes. On the other hand, if the specific gravity of the hollow filler exceeds 0.7, the reduction in specific gravity may not be sufficient.

The surface treatment of the hollow filler is not particularly limited as long as it is a method capable of improving the adhesion with the resin component (unsaturated polyester and crosslinking agent). Examples of the surface treatment of the hollow filler include surface treatment with a silane coupling agent. Specifically, a silane coupling agent may be applied to the surface of the hollow filler.
The silane coupling agent is preferably at least one selected from the group consisting of a methacrylic silane coupling agent, a styryl silane coupling agent, a vinyl silane coupling agent, and an acrylic silane coupling agent.

The methacrylic silane coupling agent means a silane coupling agent having a methacryloxy group. Examples thereof include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and 3-methacryloxy. Examples thereof include propylmethyldiethoxysilane and 3-methacryloxypropyltriethoxysilane.
The styryl silane coupling agent means a silane coupling agent having a styryl group, and an example thereof is p-styryltrimethoxysilane.
The vinyl-based silane coupling agent means a silane coupling agent having a vinyl group, and examples thereof include vinyltrimethoxysilane and vinyltriethoxysilane.
The acrylic silane coupling agent means a silane coupling agent having an acryloxy group, and an example thereof includes 3-acryloxypropyltrimethoxysilane.

The compounding quantity of the hollow filler in an unsaturated polyester resin composition is 15-22 mass%. 17-22 mass% is preferable from a viewpoint of low specific gravity, and 15-20 mass% is preferable from a viewpoint of self tap strength. If the blending amount of the hollow filler is less than 15% by mass, the specific gravity cannot be lowered sufficiently. On the other hand, when the amount of the hollow filler exceeds 22% by mass, desired self-tap strength cannot be obtained.
Here, the self-tap strength generally tends to decrease as the blending amount of the hollow filler increases. In particular, when a hollow filler that has not been subjected to a surface treatment is used, if the blending amount is 15% by mass or more, the self-tap strength is significantly reduced. As a result, when the molded product is used as the base material of the lamp reflector, the self-tap portion is destroyed when the lamp is assembled or used.

  On the other hand, in the present invention, since the surface-treated hollow filler is used, even when the blending amount is 15% by mass or more, the adhesiveness between the hollow filler and the resin component is maintained and the lamp reflector is used. A proper self-tapping strength can be ensured. However, if the amount of the hollow filler is too large, it is impossible to prevent the self-tap strength from being lowered. Therefore, the upper limit of the amount of the hollow filler needs to be 22% by mass.

  It does not specifically limit as a fiber reinforcement used for this invention, A well-known thing can be used in the said technical field. Examples of the fiber reinforcement include various organic fibers and inorganic fibers such as glass fiber, pulp fiber, Tetron (registered trademark) fiber, vinylon fiber, carbon fiber, aramid fiber, and wollastonite. Among them, it is preferable to use chopped strand glass cut to a fiber length of about 1.5 to 25 mm.

In addition to the above components, the unsaturated polyester resin composition of the present invention contains components known in the art such as a low shrinkage agent, a curing agent, a release agent, a thickener, a pigment, and a thinning agent. It can be included as long as the effects of the invention are not impaired.
Examples of the low shrinkage agent include thermoplastic polymers generally used as low shrinkage agents such as polystyrene, polymethyl methacrylate, polyvinyl acetate, saturated polyester, and styrene-butadiene rubber. These can be used alone or in combination of two or more.

  Curing agents include t-butyl peroxy octoate, benzoyl peroxide, 1,1-di-t-butyl peroxy-3,3,5-trimethylcyclohexane, t-butyl peroxyisopropyl carbonate, t-butyl peroxy Examples thereof include organic peroxides such as oxybenzoate, dicumyl peroxide, and di-t-butyl peroxide. These can be used alone or in combination of two or more.

Examples of the mold release agent include stearic acid, zinc stearate, calcium stearate, aluminum stearate, magnesium stearate, carnauba wax and the like. These can be used alone or in combination of two or more.
Examples of the thickener include metal oxides such as magnesium oxide, magnesium hydroxide, calcium hydroxide, and calcium oxide, and isocyanate compounds. These can be used alone or in combination of two or more.
The compounding amount of each component in the unsaturated polyester resin composition of the present invention is such that the content of the hollow filler in the composition is 15 to 22% by mass, and the total amount of the unsaturated polyester and the crosslinking agent is 100 parts by mass. Preferably, the crosslinking agent is 25 to 70 parts by mass, the inorganic filler is 40 to 250 parts by mass, and the fiber reinforcement is 60 to 105 parts by mass. More preferably, the crosslinking agent is 35 to 65 parts by mass, and the inorganic filler is 50. -200 mass parts and a fiber reinforcement are 70-95 mass parts.

The unsaturated polyester resin composition of the present invention constituted by the components as described above can be produced by kneading using a method usually performed in the art, for example, a kneader.
Since the unsaturated polyester resin composition of the present invention produced in this way is blended with a specific proportion of the surface-treated hollow filler, the conventional properties (surface smoothness, mechanical strength, dimensional accuracy) In addition, while maintaining the moldability, it is possible to provide a molded product that achieves both a reduction in specific gravity (less than the specific gravity of the molded product of less than 1.4) and an improvement in self-tap strength.

The unsaturated polyester resin composition of the present invention can be molded into a desired shape and cured to produce a molded product. The molding and curing method is not particularly limited, and a method usually performed in the technical field, for example, compression molding, transfer molding, injection molding, or the like can be used.
The self-tap strength of the molded product thus manufactured is preferably 1.7 N · m or more. When the self-tap strength is less than 1.7 N · m, the self-tap portion may be destroyed when fastening with a self-tapping screw.

  The molded product obtained from the unsaturated polyester resin composition of the present invention is suitable for use as a base material for a lamp reflector. That is, as for the lamp reflector, the self-tapping screw is generally used for fastening and fixing with a part for fixing the lamp reflector, a part for fixing the bulb, a part such as a hood for adjusting light, and the unsaturated polyester resin of the present invention. Since the molded product obtained from the composition has a high self-tap strength, when used as a base material for a lamp reflector, it is possible to prevent the self-tap portion from being destroyed when the lamp is assembled or used. Thereby, the lamp reflector using the molded article obtained from the unsaturated polyester resin composition of the present invention as a base material can suppress deviation in the irradiation direction.

In a lamp reflector using a molded product obtained from the unsaturated polyester resin composition of the present invention as a substrate, a metal reflective layer is formed on the substrate.
The material of the metal reflective layer is not particularly limited as long as it is used for a lamp reflector, and for example, silver, zinc, an alloy mainly composed of silver or zinc, or the like can be used.
The method for forming the metal reflective layer is not particularly limited, and for example, a known method such as a vacuum deposition method can be used.
The thickness of the metal reflective layer may be appropriately set according to the required size of the lamp reflector and the like, but is generally 800 to 2,000 mm.

Moreover, in order to improve the adhesiveness of a base material and a metal reflective layer, you may form a primer layer between a base material and a metal reflective layer.
It does not specifically limit as a primer layer, What is necessary is just to form using a well-known method in the said technical field. For example, a primer layer can be formed by applying and drying a primer composition on a substrate. The method for applying the primer composition onto the substrate is not particularly limited, and for example, a known method such as an air spray method or an airless spray method can be used. In addition, the drying method may be adjusted as appropriate according to the composition of the primer composition and the coating method.
The thickness of the primer layer may be appropriately set according to the required size of the lamp reflector and the like, but is generally 10 to 30 μm.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited by these.
Various physical properties of the unsaturated polyester resin compositions and molded articles thereof in the following Examples and Comparative Examples were evaluated as follows.
(1) Molding shrinkage rate A shrinking disk defined in JIS K6911 is manufactured by performing injection molding under conditions of a molding temperature of 150 ° C., an injection pressure of 30 MPa, and a molding time of 3 minutes. Based on JIS K6911 5.7 Mold shrinkage was calculated.
(2) Specific gravity After producing a contraction disk specified in JIS K6911 by performing injection molding under conditions of a molding temperature of 150 ° C., an injection pressure of 30 MPa, and a molding time of 3 minutes, a test piece was cut out and based on JIS K6911 Specific gravity was measured.

(3) Mechanical strength By performing compression molding under the conditions of a molding temperature of 150 ° C., a molding pressure of 10 MPa, and a molding time of 3 minutes, a bending strength and a flexural modulus test piece specified in JIS K6911 were prepared. The bending strength and bending elastic modulus were measured based on K6911.
(4) Molded product evaluation (appearance)
Transfer molding (disk shape, diameter 117 mm, thickness 3 mm (uniform)) was produced by performing transfer molding under conditions of a molding temperature of 140 ° C., an injection pressure of 25 MPa, and a molding time of 1 minute. The molded product was visually evaluated for appearance leveling and fillability. In this evaluation, those that were good were represented as ◯, those that were slightly inferior as Δ, and those that were poor as x.

(5) Self-tap strength Boss shape test piece for self-tapping (boss outer diameter φ8mm, pilot hole diameter φ3.6mm) by injection molding under conditions of molding temperature 150 ° C, injection pressure 50MPa, molding time 2 minutes Was made.
Next, the tightening torque strength at the time of destruction that occurs when this test piece is tightened with a tapping slotted screw (L = 12 mm) having a screw diameter “M4” is measured with a torque driver (Digital Torque Tester manufactured by HIOS Corporation). HDP-50 "). In this evaluation, a case where the tap strength was satisfactory was indicated as ◯, and a case where the tap strength was not satisfactory was indicated as ×.

(Preparation of unsaturated polyester)
Fumaric acid, propylene glycol, and hydrogenated bisphenol A are charged at a molar ratio of 100: 80: 20 into a four-necked flask equipped with a thermometer, stirrer, inert gas inlet and reflux condenser, and heated under a nitrogen stream. The temperature was raised to 230 ° C. while stirring, and an unsaturated polyester was obtained by carrying out an esterification reaction by a conventional procedure. When the weight average molecular weight (MW) of this unsaturated polyester was measured on the said conditions, it was 10,000.

(Surface treatment of hollow filler)
A glass balloon having a pressure strength of 80 MPa, a specific gravity of 0.6, and an average particle size of 30 μm was surface-treated with 3-methacryloxypropyltrimethoxysilane to obtain a hollow filler (A).
A glass balloon having a pressure strength of 80 MPa, a specific gravity of 0.6, and an average particle diameter of 30 μm was surface-treated with p-styryltrimethoxysilane to obtain a hollow filler (B).
A glass balloon having a pressure strength of 80 MPa and a specific gravity of 0.6 was surface-treated with vinyltrimethoxysilane to obtain a hollow filler (C).
A glass balloon having a pressure strength of 80 MPa, a specific gravity of 0.6, and an average particle size of 30 μm was surface-treated with 3-acryloxypropyltrimethoxysilane to obtain a hollow filler (D).
For comparison, a glass balloon having a pressure strength of 80 MPa, a specific gravity of 0.6, and an average particle diameter of 30 μm was used as it was. This glass balloon is represented as a hollow filler (untreated).

(Examples 1-6 and Comparative Examples 1-5)
The unsaturated polyester resin composition obtained by kneading the unsaturated polyester and hollow filler obtained above and each component shown in Table 1 at 30 ° C. using a double kneader at the ratio shown in Table 1. Obtained. In Table 1, the unit of the amount of each component is part by mass.
Said evaluation was performed about the unsaturated polyester resin composition obtained in this way. The results are shown in Table 1.

As shown in Table 1, the unsaturated polyester resin compositions of Examples 1 to 6 are low in specific gravity and self while maintaining the molding shrinkage rate, mechanical strength and appearance at the same level as in the comparative example. A molded product having both improved tap strength was obtained.
On the other hand, since the unsaturated polyester resin composition of Comparative Examples 1-3 used the hollow filler which has not surface-treated, the self tap intensity | strength of the molded object fell. Moreover, although the unsaturated polyester resin composition of Comparative Example 4 was able to maintain the self-tap strength of the molded product by reducing the content of the hollow filler, the specific gravity of the molded product was not sufficiently reduced. . Furthermore, in the unsaturated polyester resin composition of Comparative Example 5, the ratio of the hollow filler in the composition was too large, so that the self-tap strength and the appearance of the molded product were lowered.

  As can be seen from the above results, according to the present invention, an unsaturated polyester resin composition for a lamp reflector that provides a molded article that achieves both low specific gravity and improved self-tap strength while maintaining conventional characteristics. Can be provided.

Claims (5)

An unsaturated polyester resin composition for a lamp reflector comprising an unsaturated polyester, a crosslinking agent, an inorganic filler, a hollow filler and a fiber reinforcement,
The hollow filler is surface-treated with a silane coupling agent , and the content of the hollow filler in the unsaturated polyester resin composition for lamp reflector is 15 to 22% by mass. Unsaturated polyester resin composition for lamp reflectors. The silane coupling agent is at least one selected from the group consisting of a methacrylic silane coupling agent, a styryl silane coupling agent, a vinyl silane coupling agent, and an acrylic silane coupling agent. The unsaturated polyester resin composition for lamp reflectors according to claim 1 . The unsaturated polyester resin composition for a lamp reflector according to claim 1 or 2 , wherein the molded product has a self-tap strength of 1.7 N · m or more. A molded article, which is a molded and cured body of the unsaturated polyester resin composition for a lamp reflector according to any one of claims 1 to 3 . A lamp reflector comprising the molded product according to claim 4 as a base material.