Non-baked color pencil leads and method for preparing same
US5318622A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | May 6, 1993 |
| Grant date | Jun 7, 1994 |
| Priority date | — |
| Expiry date | May 6, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09D13/00
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Novel non-baked color pencil leads are here disclosed which can be obtained by forming a blend composition from a filler, a pigment, a binder and the like without using any wax, at least one of the pigment and the filler being all or partially covered with a fluorinated aromatic compound, kneading the blend composition with a solvent and/or a plasticizer, extruding the kneaded material, drying the extruded articles to remove the solvent and/or the plasticizer therefrom, and then impregnating the porous articles with an oil, a fat and/or a wax. The thus obtained non-baked color pencil leads are remarkably excellent in mechanical properties such as bending strength and pointed end strength, has a smooth writing performance, and permits the drawing of uniform lines. A high-temperature and short-time drying treatment is possible, which can remarkably decrease a manufacturing cost. The color pencil leads which can be erased with an eraser or the color pencil leads which cannot be erased with an eraser can be selectively prepared.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.