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:
Nov. 23, 1976
Filed:
Jan. 12, 1976
Peter A Isaac, Summit, NJ (US);
T Dixon Oulton, Watchung, NJ (US);
Engelhard Minerals & Chemicals Corporation, Edison, NJ (US);
Abstract
A reduced charge montmorillonite pigment useful as a colorformer in record material, especially pressure-sensitive carbonless copying record systems. The pigment is produced by replacing exchangeable cations of a selected dioctahedral montmorillonite crude clay (exemplified by certain bentonite clays) with a predetermined amount of lithium ions, mildly heating the lithium-exchanged montmorillonite to collapse irreversibly the montmorillonite structure, and grinding the heat-treated material to pigment-size particles, the grinding preferably being carried out in a fluid energy mill. When the pigment particles are coated on paper, the coated sheets produce stabilized intense images when printed with a solution of crystal violet lactone (CVL) dye precursor and thus may be used in record material with CVL without employing secondary slow acting dyes such as benzoyl leuco methylene blue. The sheets are also useful with other colorless or substantially colorless dye precursors.