The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 04, 1983
Filed:
May. 05, 1982
Frank A Muller, Los Angeles, CA (US);
Scripto, Inc., Doraville, GA (US);
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 in amount sufficient to impart a final ink viscosity in the range of about 1.5 million cps.