Erasable colored pencil lead
US6262143A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 1998 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Nov 20, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09D13/00
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The present invention provides an erasable colored pencil lead composition comprising a colorant, one or more binder resins, a fibrillatable or fibrillated material, and a filler. The colored pencil lead of the present invention produces marks on paper which are easily erased by ordinary pencil eraser. The mark made using the composition has a cohesive nature which assists in the removal from paper in sheet or film like sections by the use of an ordinary eraser without smearing or leaving a residue. In a preferred embodiment, the composition is free or substantially free of low melting waxes or wax like materials. Examples of suitable binder resins include high density polyethylene, low density polyethylene, polypropylene, and high melting waxes. Examples of fibrillated or fibrillatable materials include fibrillatable or fibrillated polytetrafluoroethylene and ethylene-vinyl acetate copolymer. The colored pencil lead composition may further include a lubricant. Examples of the lubricants include micronized PTFE and polyethylene glycols. The present invention further provides a process for using the colored pencil lead composition. The present invention further provides a process fo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.