Baked color pencil lead and process for producing the same
US6709501B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 24, 2002 |
| Grant date | Mar 23, 2004 |
| Priority date | — |
| Expiry date | May 24, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09D13/00
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Provided is a baked color pencil lead which comprises a baked lead obtained by impregnating pores of a porous baked lead comprising at least a filler with a solution containing a polysiloxane having a structural unit represented by the following Formula (I) and subjecting it to heat treatment in an oxidation atmosphere and/or a non-oxidation atmosphere and a colorant filled into the pores of the resultant baked lead and which is excellent in mechanical strength (bending strength, tensile strength, impact strength and the like) while exhibiting a satisfactory coloring power and sufficient drawn line density: wherein R1 and R2 each represent an alkyl group, an alkoxy group, a hydroxy group or a siloxane group, and they may be the same or different.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.