Thermoplastic resin composition for light reflector, formed article for light reflector, light reflector, and method for producing formed article for light reflector

Patent metadata

Field	Value
Publication number	US-9671531-B2
Application number	US-201314018720-A
Country	US
Kind code	B2
Filing date	Sep 5, 2013
Priority date	Aug 26, 2003
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

Thermoplastic resin composition for a light reflector such as a housing, reflector, and extension of an automotive lamp, and a lighting fixture. The composition contains 2 to 45 parts by mass of an inorganic filler treated with a fatty acid type surface treating agent and has an average diameter of not more than 3 μm, per 100 parts by mass of a thermoplastic resin. The housing reflector made from such thermoplastic resin composition shows excellent surface smoothness, surface luster and surface image clarify.

First claim

The invention claimed is:

1. A light reflector, comprising:
a light reflecting metal layer; and
a molded article having a surface;
wherein
the light reflecting metal layer is directly formed on at least a part of the surface of the molded article, and
the molded article comprises:
a thermoplastic resin (A) at least one of an ester of a fatty acid and a salt of fatty acid in an amount of from 0.01 to 3 parts by mass with respect to 100 parts by mass of the thermoplastic resin (A); and
2 to 45 parts by mass of precipitated barium sulfate per 100 parts by mass of the thermoplastic resin (A);
wherein
the thermoplastic resin (A) contains a polyester resin (a),
the polyester resin (a) contains a polybutylene terephthalate (a-1) and a polyethylene terephthalate (a-2),
an amount of the polyester (a) is 85% by mass or more with respect to a total mass of the thermoplastic resin (A),
a refractive index (α) of the precipitated barium sulfate is from 1.64 to 1.65,
an average particle diameter of the precipitated barium sulfate is 3 μm or less, and
a diffused reflectance of the light reflector after a heat resistance test is not more than 3%.

2. The light reflector according to claim 1 wherein the average particle diameter of the precipitated barium sulfate is not more than 1 μm.

3. The light reflector according to claim 1 , wherein the thermoplastic resin (A) further comprises 3 to 15% by mass of a vinyl thermoplastic resin (x).

4. The light reflector according to claim 1 , wherein the molded article comprises the fatty acid ester and the fatty acid ester is at least one glycerol ester selected from the group consisting of a glycerol triester of a fatty acid and a glycerol diester of a fatty acid.

5. The light reflector according to claim 1 wherein the molded article has at all times a light reflectance, at the surface of the molded article, of 65% or more at a wave length of light in the range of from 420 to 700 nm and has a linear shrinkage of not more than 1.6%.

6. The light reflector according to claim 5 wherein the light reflectance, at the surface of the molded aticle is 70% or more at a wage length of light in the range of from 420 to 700 nm.

7. The light reflector according to claim 1 , wherein an amount of the polyester resin (a) is 90% by mass or more with respect to the total mass of the thermoplastic resin (A) of the molded article.

Assignees

• Mitsubishi Rayon Co

Inventors

• Shirai Yasunori
• Ueda Haruo
• Takagi Tamae

Classifications

• B29C45/0001 Primary

  characterised by the choice of material · CPC title

• C08K5/103

  with polyalcohols · CPC title

• G02B5/0866 Primary

  incorporating one or more organic, e.g. polymeric layers · CPC title

• B29C45/0013

  using fillers dispersed in the moulding material, e.g. metal particles · CPC title

• B29L2031/747

  Lightning equipment · CPC title