Coating for halogen lamps
AssigneeEdison International, Inc.
InventorRollin G. Brown
Life of this patent
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Abstract
The invention relates to a composition for an opaque coating for minimizing the light output from selected areas of an incandescent lamp, particularly a halogen lamp. It has been discovered that a paste comprising a mixture of sodium silicate and manganese dioxide, when thinned with water to a desired consistency, then applied to the external surface of a halogen lamp bulb and properly dried, forms a tightly adhering, opaque coating of dark gray color which resists flaking and blistering at operational temperatures of the halogen lamp.
Claims12
A composition for coating the bulb surface of an incandescent lamp, said composition including;
- (a) sodium silicate, said sodium silicate comprising silicon dioxide and sodium oxide in proportion by weight of approximately 2:1 and
- (b) manganese dioxide, said manganese dioxide being finely divided and in proportion by weight with respect to said sodium silicate in the range between approximately 4:1 and approximately 5:1.
A mixture for application as a coating on the bulb surface of an incandescent lamp comprising:
- (a) sodium silicate, said sodium silicate comprising silicon dioxide and sodium oxide in proportion by weight of approximately 2:1;
- (b) finely divided manganese dioxide, said manganese dioxide being in proportion by weight to said sodium silicate in the range between approximately 4:1 and approximately 5:1;
- and
- (c) water for thinning said sodium silicate and manganese dioxide to a selected viscosity.
A composition for coating an external surface portion of a halogen lamp bulb for substantially blocking the light emitted in the direction of the coated portion thereof comprising:
- (a) sodium silicate, said sodium silicate comprising silicon dioxide and sodium oxide in proportion by weight of approximately 2:1;
- (b) finely divided manganese dioxide, said manganese dioxide being in proportion by weight to said sodium silicate in the range between approximately 4:1 and approximately 5:1;
- and
- (c) water for thinning said sodium silicate and manganese dioxide to a selected viscosity.
A composition for coating an external surface portion of a halogen lamp bulb for substantially blocking the light emitted in the direction thereof comprising:
- (a) 16 parts by weight sodium silicate, said sodium silicate comprising silicon dioxide and sodium oxide in a ratio by weight of approximately 2:1;
- (b) 65 parts by weight manganese dioxide powder, said powder having average particle diameter less than or equal to 20 microns;
- and
- (c) 19 parts by weight deionized water.
A method for coating an incandescent lamp bulb comprising the steps of:
- (a) mixing sodium silicate and finely divided manganese dioxide to a paste, said sodium silicate comprising silicon dioxide and sodium oxide in proportion by weight of approximately 2:1, said finely divided manganese dioxide being in proportion by weight to said sodium silicate in the range between approximately 4:1 and approximately 5:1;
- (b) thinning said paste with water to a selected viscosity;
- (c) applying the thinned paste mixture to a selected portion of the external surface of an incandescent lamp bulb;
- and
- (d) drying said thinned paste to form a coating on said selected portion.
Dependencies are inferred from the claim text.