Lamp for vehicle

Abstract

A vehicle lamp includes a reflective member having a silver vapor deposition reflective surface with good durability to prevent cracking or peeling of a protective film and capable of maintaining a high reflectance. The reflective member includes a topcoat layer which serves as a protective film on a silver vapor deposition film which is a silver alloy including Nd on a surface of a base material made of synthetic resin inside a lamp chamber S. The topcoat layer 64 includes a transparent modified silicone series resin using a silicone resin and an acrylic resin as resin components.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal sectional view of a head lamp for an automobile according to a first embodiment of the invention.

FIG. 2 is an enlarged sectional diagram of a reflective surface of an extension reflector disposed in the same head lamp.

FIG. 3 is a diagram showing a correlation between a reflectance of a silver alloy vapor deposition reflective surface and an additive amount of Nd in an alloy of Ag and Nd.

FIG. 4(a) is a diagram explaining action in which an Nd atom in a silver vapor deposition film inhibits cohesion of Ag atoms (crystal grains of Ag), and FIG. 4(b) is a diagram explaining action in which acrylic molecules in a topcoat layer inhibit cohesion of Ag atoms (crystal grains of Ag).

FIG. 5( a) is a diagram explaining a situation of heat motion of the case where a general topcoat layer made of resin receives heat energy, and FIG. 5(b) is a diagram explaining a situation of receiving heat energy and a network structure of a modified silicone series topcoat layer using a silicone series resin and an acrylic resin as resin components.

FIG. 6 is an explanatory diagram of a transition state at the time when a migration phenomenon occurs in a topcoat layer.

FIG. 7( a) is an enlarged sectional diagram of a reflective surface of an extension reflector which is a main part of a head lamp for automobile according to a second embodiment of the invention, and

FIG. 7( b) is an enlarged sectional diagram of a reflective surface of an extension reflector which is a main part of a head lamp for an automobile according to a third embodiment of the invention.

FIG. 8( a) is a sectional diagram of a reflective surface of a reflector which is a main part of a head lamp for automobile using an LED as a light source according to a fourth embodiment of the invention, and FIG. 8(b) is an enlarged sectional diagram of the reflective surface of the reflector.

FIG. 9 is an enlarged sectional diagram of a reflective surface of a reflective member such as a conventional reflector or an extension reflector.

FIG. 10 is an explanatory diagram explaining action in which Ag atoms constructing a silver vapor deposition film formed on a surface of a base material receive heat energy and vibrate and cohere.

Claims

1. A vehicle lamp comprising a reflective member having a topcoat layer as a protective film on a silver vapor deposition film on a surface of a base material made of synthetic resin inside a lamp chamber, wherein the silver vapor deposition film comprises a silver alloy including Nd, and the topcoat layer comprises a transparent modified silicone series resin including a silicone resin and an acrylic resin.

2. A vehicle lamp as claimed in claim 1 wherein the silicone resin is in the range of 50 to 70% by weight and the acrylic resin is in the range of 30 to 50% by weight in a content ratio between resin components of the modified silicone series resin.

3. A vehicle lamp as claimed in claim 1 wherein the reflective member is an extension reflector.

4. A vehicle lamp as claimed in claim 1 wherein the reflective member is a reflector for an automobile head lamp with an LED as a light source.

5. A vehicle lamp as claimed in claim 2 wherein the reflective member is an extension reflector.

6. A vehicle lamp as claimed in claim 2 wherein the reflective member is a reflector for an automobile head lamp with an LED as a light source.