Claims
- 1. A binderless coating composition, free from allkaline and alkaline earth metallic oxides, hafnium, silica, and alumina, comprising substantially pure zirconium oxide suspended in an aqueous zirconyl nitrate and ammonium hydroxide gel.
- 2. The coating composition of claim 1, wherein zirconium oxide particles in said gel are sized from about 10 microns to about 1 micron.
- 3. The coating composition of claim 1 wherein the suspension of zirconyl nitrate in said gel is acidified at ambient temperature before application to a pH value of from about 3 to about 4.
- 4. The coating composition of claim 1 wherein the proportion of zirconyl nitrate to water is in the range of from about 1 Kg of zirconyl nitrate to about 5 liters of water and the amount of ammonium hydroxide is that amount which will produce a pH value of from about 8 to about 11.
- 5. The coating composition of claim 4, wherein the proportion of zirconium oxide to zirconyl nitrate is about from 3 to about 50 parts by weight of zirconium oxide to about 1 part by weight of zirconyl nitrate.
- 6. A method of making a binderless water based zirconium crucible coating composition comprising the steps of:
- (a) dissolving zirconyl nitrate in the water;
- (b) adding ammonium hydroxide to the aqueous solution containing zirconyl nitrate to form a gel having a pH value of from about 8 to about 11;
- (c) adding sufficient substantially pure zirconium oxide free from alkaline and alkaline earth metallic oxides, hafnium, silica and alumina particles having a size of from about 10 microns to about 1 micron to said gel to form a suspension of zirconium oxide in said gel.
- 7. The method of claim 6 wherein said gel containing the suspension of zirconium oxide particles is acidified by the step of adding sufficient nitric acid to adjust the pH value of the gel suspension to a value of from about 3 to about 4.
Parent Case Info
This is a division of application Ser. No. 07/240,001, filed Sep. 2, 1988 now U.S. Pat. No. 4,856,576.
US Referenced Citations (7)
Foreign Referenced Citations (1)
Number |
Date |
Country |
3095117 |
Apr 1988 |
JPX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
240001 |
Sep 1988 |
|