JPS6132762B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lamp reflector particularly suitable for use in automobile headlamps and fog lamps, and a method for manufacturing the same.

The lamp reflector of the present invention has a reflective coating on the inner surface of a dish-shaped body made by curing a low-profile polyester molding composition containing glass fibers and a fatty acid ester as a compatible internal mold release agent. be. "Compatible" here means that the mold release agent is compatible or miscible with the remaining components of the molding composition;
Also, "low profile" refers to the property of a polyester molding composition that allows it to produce molded bodies with little or no surface roughness or deformation.

Preferably, the glass fiber content of the above composition is
The content should be 1.0 to 25% by weight.

Preferably, the composition is catalyzed with an aliphatic peroxy compound such as tertiary butyl peroctoate.

Although a method for manufacturing a dish-shaped body of a lamp reflector by curing a low-profile polyester molding composition containing glass fibers and a mold release agent in the form of a fatty acid or a fatty acid salt is known, the present inventors conducted experiments. discovered that when this reflector was used with high-intensity light bulbs, the release agent (e.g., zinc stearate or calcium stearate) condensed on the reflective surface after evaporation due to the high temperature, causing it to fog up. It has been found that this problem can be solved by using a fatty acid ester as a mold release agent.

Furthermore, according to experiments conducted by the present inventors, benzoyl peroxide, which is conventionally used as a catalyst together with known polyester molding compositions, tends to cause benzoic acid to precipitate on the reflective surface, but this problem also occurs when tertiary butyl peroctoate, etc. It became clear that this problem could be solved by using an aliphatic peroxy catalyst.

An embodiment of the present invention will be described below with reference to the drawings.

In the drawing, 11 is a dish-shaped reflector body of a fog lamp, which is closed by a lens element 12 and houses a light bulb 13 inside. A reflective coating made of vacuum-deposited aluminum is formed on the inner surface 15 of the reflector main body 11. Reference numeral 14 denotes a bracket provided on the reflector main body 11 for attaching the fog lamp to an automobile.

The reflector body 11 is made of 0.5 parts by weight of tertiary butyl peroctoate, 20 parts by weight of a styrene solution of unsaturated polyester resin, 15 parts by weight of glass fiber with a length of about 0.64 cm (0.25 inches), and 58 parts by weight of calcium carbonate filler. , a low profile polyester molding composition which is a mixture of 1 part by weight of Roxiol G10 (registered trademark of Henkel GmbH, partial fatty acid ester of glycerin), 4 parts by weight of polypropylene adipate and 1.5 parts by weight of finely divided polystyrene. There is. As the styrene solution of unsaturated polyester and polypropylene adipate, a mixture commercially available from BP Chemicals (International) Limited under the name Cerobond A711/22 can be used, preferably with an inhibitor (for example, butyl). Hydroxytoluene) is added to the above mixture to improve shelf life.

After mixing the above molding composition and dispersing the glass fibers, it is poured into an appropriately shaped mold and closed.
Subsequently, the composition is cured by heating to form the reflector main body 11. In this case, it is preferable to inject the molding composition by injection molding, since it has been found that removing all air from the molding composition prior to injection improves the surface finish of the final reflector body 11. For this purpose, it is convenient to supply the composition to the injection device by means of a hopper connected to a negative pressure source, and to evacuate the space above the composition to remove air before injection. A suitable machine for such an injection molding process is the one commercially available from George Seidl KG Munich as model FPA1BX-A.

Also, during curing, the mold should be kept at approximately 132° to 165°C (270°C).
It is preferable to heat the film to a temperature of 0.5 to 330 °C, and the curing time is 0.5 to 330 °C depending on the thickness of the intended reflector body.
minutes. It has been found that the shrinkage of the composition upon curing is negligible, and at the same time, the surface of the reflector main body 11 removed from the mold is free from distortion and is rich in gloss.

Next, a lacquer serving as a base layer is applied to the inner surface 15 of the reflector main body 11, and an aluminum film is formed on the lacquer. The lacquer adheres to the aluminum coating as well as the inner surface 15 of the reflector, and is preferably made of polyester. If desired, multiple lacquers may be applied to the inner surface 15 before the aluminum is deposited, and it may be desirable to apply a primer to the inner surface 15 prior to applying the lacquer. The above lacquer may also be applied on top of the aluminum coating.

According to experiments, when a lamp using a reflector with the above configuration is used with a high-intensity light bulb,
Even at high temperatures of 170°C to 170°C, the aluminum coating did not become cloudy.

As another example, when the mold release agent of the molding composition is a complex fatty acid ester mold release agent commercially available from Henkel GmbH under the name Roxiol (registered trademark), the reflector main body as a final product may be used. was fully applicable to automobile lamps using high-intensity light bulbs.

[Brief explanation of the drawing]

The drawing is a sectional view showing an automobile fog lamp provided with a reflector according to the present invention. 11... Reflector main body, 12... Lens element, 1
3...Light bulb, 14...Bracket, 15...Inner side.

Claims (1)

[Scope of Claims] 1. A lamp reflector in which an aluminum reflective coating is applied to the inner surface of a dish-shaped body formed by curing a low-profile polyester molding composition containing glass fibers, wherein the molding composition has a compatible internal separation. A lamp reflector characterized by containing a fatty acid ester as a molding agent and an aliphatic peroxy compound as a curing catalyst. 2. A lamp reflector according to claim 1, wherein the molding composition contains 10 to 25% by weight of glass fibers. 3. A lamp reflector according to claim 1, wherein the aliphatic peroxy compound is tert-butyl peroctoate. 4. A lamp reflector according to claim 1, wherein the aluminum reflective coating comprises a lacquer layer as a base layer and an aluminum layer as a surface layer. 5. A lamp reflector as claimed in claim 4, wherein the lacquer is selected from polyester, epoxy, acrylic or alkyd resins. 6 molding and curing a low profile polyester molding composition containing glass fibers, a fatty acid ester as an internal mold release agent, and an aliphatic peroxy compound as a curing catalyst to obtain a dish-shaped body; A method for manufacturing a lamp reflector, comprising forming an aluminum reflective coating on the inner surface of the lamp reflector.