Method of making and the composition for an initially erasable ink for a ball point writing instrument
US4410643A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 7, 1982 |
| Grant date | Oct 18, 1983 |
| Priority date | — |
| Expiry date | May 7, 2002 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB43L19/0018
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method for making and the composition for an initially erasable ink 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 method includes the steps of: (a) selecting elastomeric material from synthetic rubbers not having the chemical structure of natural rubber, with or without cis-1,4-polyisoprene, and mixtures thereof; (b) masticating the selected elastomeric material by subjecting same to high shear stresses; (c) coloring said masticated elastomeric material by forced impregnation of colored pigments into said elastomeric material while subjecting same to further shear stresses; and (d) mixing the pigmented elastomeric material with a solvent system that includes a volatile component and an essentially non-volatile low viscosity component in the form of a hydrocarbon oil, an essential oil, a petroleum derivative, a plasticizer or mixtures thereof to form an erasable ink composition. The ink composition comprises a pre-pigmented elastomer and a solvent system that contains a volati…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.