Patent · US Expired

Granular p-phenylenediamine color developing agent

US3981732A · kind A · utility

11Cited by
5References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 9, 1974
Grant dateSep 21, 1976
Priority date
Expiry dateApr 9, 1994

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03C5/265
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A process for preparing a granular color developing agent, which comprises kneading a mixture of at least one excipient selected from the group consisting of water and lower alcohols and a p-phenylenediamine color developing agent, and granulating the mixture is disclosed.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.