Chalking-resistant, calcined kaolin clay pigment and method of making
US4525518A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 23, 1984 |
| Grant date | Jun 25, 1985 |
| Priority date | — |
| Expiry date | Jan 23, 2004 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/60
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Novel pigments useful as primary extenders in exterior grade latex formulations are described. The pigments are composed of particles of calcined clay, substantially all the particles of which are finer than about 44 microns and having an average particle size, equivalent spherical diameter, within the range of about 3 to 10 microns, most preferably within the range of about 4 to 8 microns. The novel pigments are further characterized by having a significantly lower oil absorption value (ASTM) than conventional, calcined clay pigments. Exterior grade paint formulations containing such pigments can be formulated below the critical pigment volume concentration without substantially reducing opacity or chalking resistance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.