Non-settling coating composition and flatting pigment
US4155769A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 14, 1977 |
| Grant date | May 22, 1979 |
| Priority date | — |
| Expiry date | Nov 14, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2982
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A coating composition such as nitrocellulose lacquer or varnish incorporates a flatting pigment having non-settling properties obtained by grinding a dried precipitated hydrated silica and calcining it at a temperature between 400.degree. C. and 600.degree. C. so that the pigment consists of particles smaller than 10 microns in size having a bound water content below 2%. The calcination may be effected before or after the grinding. Advantageously, a wet precipitated hydrated silica is spray-dried to about 12% or less total moisture; the dried hydrated silica is milled and air classified to obtain material consisting entirely of particles smaller than 10 microns in size; and these particles are calcined at a temperature between 450.degree. C. and 550.degree. C. The pigment product so obtained exhibits outstanding non-settling flatting characteristics in nitrocellulose lacquer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.