Method of making and improved compositions for an initially erasable ink for a ball point writing instrument
US4407985A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 5, 1982 |
| Grant date | Oct 4, 1983 |
| Priority date | — |
| Expiry date | May 5, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09D11/18
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
An initially erasable ink composition for a ball point writing instrument which ink is characterized by its initial erasability by ordinary pencil erasers when applied by a ball point writing instrument to an absorbent paper-like writing surface and which thereafter develops permanence. The ink composition comprises polar elastomers, such as butadiene/acrylonitrile copolymer rubbers and vinyl acetate/ethylene copolymer rubbers, and mixtures thereof, either alone or in admixture with cis-1, 4-polyisoprene (natural rubber or synthetic nature rubber), pigment, and a solvent system. The polar elastomer is present in the range of about 14-25% by weight of the ink and the pigment is present in amount sufficient to impart color and intensity to a trace of the ink when applied to a substrate such as paper. The solvent system essentially comprises a volatile component having a boiling point less than about 180.degree. C. and an essentially non-volatile component which includes pigment vehicle having a boiling point greater than about 300.degree. C. and low viscosity plasticizer having a boiling point greater than 180.degree. C. but less than 300.degree. C., the solvent system being present …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.