JPH08208959A - Lamp reflector - Google Patents

Abstract

PURPOSE: To obtain a lamp reflector which has good surface properties and does not cloud the surface of glass used. CONSTITUTION: This lamp reflector is obtd. by molding a polyester resin compsn. contg. 100-50 pts.wt. polyalkylene naphthalate resin, 0-50 pts.wt. polyethylene terephthalate resin, and 0-150 pts.wt. inorg. reinforcement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lamp reflector, and more particularly to a lamp reflector which is used as lighting for an automobile or a room and which has a good glass surface and has good moldability and surface gloss.

[0002]

2. Description of the Related Art Conventionally, an iron plate has been used as a lamp reflector. However, with the demand for higher functionality, the shape of the headlamp has become smaller and thinner, and the shape has become complicated, so that molded products of unsaturated polyester resin compositions have come to be used. In recent years, the use of unsaturated polyester resins has decreased due to work efficiency, and the use of thermoplastic resins such as polyamide resins and polyethylene terephthalate resins has progressed. However, there is a problem that moisture is generated in the case of a polyamide resin and heat decomposition is generated in the case of a polyalkylene terephthalate resin due to heating of a lamp which is used at a high temperature for a long time, and a lens is fogged up, so that specifications are limited.

[0003]

As described above, the lamp reflector made of polyamide resin has a problem that moisture absorbed by the reflector is evaporated by the heating of the lamp and is condensed on the glass surface to cloud the glass surface. Further, a reflector made of a polyalkylene terephthalate resin such as polybutylene terephthalate has a problem in that the glass surface of the thermally decomposed product is sublimated and the glass surface becomes cloudy.
The present invention has been made to solve the above problems, and has good surface properties and moldability, and even when used for a long period of time at high temperature, glass is formed by condensation of hygroscopic moisture and sublimation of thermal decomposition products. It is an object to provide a lamp reflector whose surface does not fog.

[0004]

Means for Solving the Problems The inventors of the present invention have made extensive studies as a result of the above-mentioned problems in order to obtain a lamp reflector having good surface properties and moldability, and which does not fog the glass surface used in combination. Finally, the present invention has been completed. That is, the present invention provides 100 to 50 parts by weight of polyalkylene naphthalate resin, 0 to 50 parts by weight of polyethylene terephthalate resin, and 0 to 1 of inorganic reinforcing material.
It is a lamp reflector formed by molding a polyester resin composition containing 50 parts by weight.

In the lamp reflector of the present invention, the polyester resin composition is injection-molded, and the surface of the obtained molded product is coated with a metal such as aluminum or zinc by a method such as vacuum deposition. Although obtained, it also includes the case where a metal coating is not applied as a part of the molded body. An example of one embodiment of the lamp reflector of the present invention is specifically shown in FIGS. 1 and 2. FIG. 1 is a perspective view of an embodiment of an automobile lamp unit including an automobile lamp reflector 1, a lamp case 2 and a lamp 3 used in combination with the lamp reflector 1, and a glass 4 covering the whole thereof. FIG. 2 is a perspective view of an embodiment of a headlamp in which the lamp unit is assembled.

The polyalkylene naphthalate resin used in the present invention is not only a polyethylene naphthalate resin, a polybutylene naphthalate resin, a polypropylene naphthalate resin, etc., but also a copolymerized polyester containing 80 mol% or more of these repeating units. Resins may be mentioned. As the copolymer component, a known acid component or glycol component can be used. That is, examples of the copolymerization component include acid components such as terephthalic acid, isophthalic acid, adipic acid, sebacic acid, diphenylene ether 4,4'dicarboxylic acid, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, neopentyl. Glycol, cyclohexanedimethanol,
Examples thereof include glycol components such as 2,2-bis (4-hydroxyphenyl) propane, and oxyacids such as P-oxybenzoic acid and P-hydroxyethoxybenzoic acid.
Two or more of these may be used in combination.
The polyalkylene naphthalate resin is preferably a polybutylene naphthalate resin or a polyethylene naphthalate resin from the viewpoint of performance and moldability, or a copolymer thereof. In the present invention, the polybutylene naphthalate resin is a polybutylene naphthalate resin at a low temperature. It is particularly preferable because good heat resistance and surface property can be obtained with a mold. Further, the polyalkylene naphthalate resin used in the present invention has a reduced specific viscosity of 0.4 or more, preferably 0 when measured at 30 ° C. with a phenol / tetrachloroethane mixed solvent (6/4 weight ratio). .5 or more.

When a particularly good surface property is required in the present invention, the polyethylene terephthalate resin used together with the polyalkylene naphthalate resin is a copolymerized polyester containing at least 80 mol% of ethylene naphthalate repeating units. Is mentioned. As the copolymer component, a known acid component or glycol component can be used. Specific examples thereof include the same acids and glycols as those described for the polyalkylene naphthalate resin. In the present invention, the polyethylene terephthalate resin is blended in an amount of 0 to 50 parts by weight, preferably 2 to 45 parts by weight, based on 100 parts by weight of the polyalkylene naphthalate resin. When the polyethylene terephthalate resin is blended, the surface property is improved, but when it exceeds 50 parts by weight, a thermal decomposition product is generated, which is not preferable.

Further, as the inorganic reinforcing material used as required in the present invention, fiber reinforcing material such as glass fiber and carbon fiber, whisker such as titanic acid, talc, wollastonite, bentonite, montmorillonite, calcium carbonate, etc. The powder reinforcing material of
Powder reinforcements such as talc, clay and wollastonite. The inorganic reinforcing material increases the rigidity and heat deformation temperature of the molded product, increases the dimensional stability, and provides a stable luminous flux even after long-time lighting. Therefore, depending on the application, 0 to 150 parts by weight, and more preferably 10 to 100 parts by weight are blended with 100 parts by weight of the polyalkylene naphthalate resin. If it exceeds 150 parts by weight, the appearance of the molded product deteriorates,
Further, the fluidity at the time of molding is also deteriorated, which is not preferable.

[0009]

Since the lamp reflector of the present invention is formed from a resin composition containing a polyalkylene naphthalate resin as a main component, it has a good surface property and moldability, and is a pyrolyzate which is sublimable during use. Since it is extremely rare, the glass surface does not become cloudy even after long-term use. The reason why the polyalkylene naphthalate resin does not haze the glass surface while the polyalkylene terephthalate resin hazes the glass surface is not clear yet.
It has high heat resistance and does not easily decompose even if it reaches 0 ° C.
It is also considered that the naphthalenedicarboxylic acid generated by decomposition has a much lower sublimation property than the terephthalic acid generated in the case of polyalkylene terephthalate.

[0010]

EXAMPLES The present invention will be specifically described below with reference to examples. Parts and% in the examples are based on weight. In addition, the deflection temperature under load of the injection molded product is ASTM D648
According to the above, the measurement was performed under a load of 4.6 kg / cm ² . The amount of precipitation on the glass surface and the haze of the glass surface were evaluated as follows. Place a 10 mm @ 3 molded product with a thickness of 3 mm on a hot plate adjusted to a surface temperature of 200.degree.
The glass tube of mmΦ × 70 mmL and the top surface were covered with a glass plate and treated for 240 hours. Parts other than the glass tube were covered with a heat insulating plate to prevent heat radiation from the hot plate surface to the top surface. After the treatment, the amount of precipitation obtained from the weight change of the glass plate on the top surface and the haze of the central portion were measured.

Examples 1 to 14 and Comparative Examples 1 to 7 Polybutylene naphthalate resin, polyethylene naphthalate resin, polyethylene terephthalate resin, polybutylene terephthalate resin, talc, wollastonite, glass fiber, montanic acid ester are shown in Table 1 respectively. After melt-mixing in the proportion shown in, put into the hopper of the twin-screw extruder
Melt kneading was performed to obtain compound chips. The compound chip was dried at 130 ° C. for 4 hours, and then a test piece was molded by an injection molding machine adjusted to a cylinder temperature of 270 ° C., and physical properties required as a lamp reflector were evaluated. Table 1 shows the results.

[0012]

[Table 1]

[0013]

[Table 2]

[0014]

As is clear from Table 1, the lamp reflector of the present invention shows that the haze due to sublimation on the glass surface is small and the transparency of the glass surface is maintained when used at high temperature. In addition, this result corresponds well with the result of the practical test of the lamp unit for automobiles. Further, according to the present invention, while maintaining good surface properties and moldability, the amount of the decomposition products deposited during high temperature use is small and the glass surface is not fogged, so the degree of freedom in design is increased, and at high temperatures Can also be used, and the range of application can be expanded to applications that could not be used before, which is a great contribution to the industrial world.

[Brief description of drawings]

FIG. 1 is a perspective view of an exemplary embodiment of an automobile lamp unit.

FIG. 2 is a perspective view of an example of an embodiment of a vehicle headlamp.

[Explanation of symbols]

 1: Lamp reflector 2: Lamp case 3: Lamp 4: Glass

Claims (2)

[Claims] 1. A polyester resin composition containing 100 to 50 parts by weight of a polyalkylene naphthalate resin, 0 to 50 parts by weight of a polyethylene terephthalate resin, and 0 to 150 parts by weight of an inorganic reinforcing material. Lamp reflector to do. 2. The lamp reflector according to claim 1, wherein the polyalkylene naphthalate resin is a polybutylene naphthalate resin.