Patent · US Expired

Method and composition for hardening gelatin

US5236822A · kind A · utility

4Cited by
4References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 3, 1991
Grant dateAug 17, 1993
Priority date
Expiry dateOct 3, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03C1/047
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A method for hardening gelatin which comprises using as a hardening agent a compound represented by formula (I): ##STR1## wherein R.sub.1, when taken along, may be alkyl of 1 to 20 carbon atoms, aralkyl of from 7 to 20 carbon atoms, aryl of from 6 to 20 carbon atoms, and alkenyl of from 2 to 20 carbon atoms. R.sub.1 and R.sub.2 can also combine with each other to form a heterocyclic ring of 5 to 8 atoms. The R.sub.1 -R.sub.2 ring contains the nitrogen atoms to which R.sub.1 and R.sub.2 are attached, and may also contain an additional nitrogen atom. R.sub.2 and R.sub.3 can combine to form either a 5 or 6 membered ring. The R.sub.2 -R.sub.3 ring contains the nitrogen atom to which R.sub.2 is attached, and may also contain one or two additional nitrogen atoms. R.sub.4 may be hydrogen or alkyl of 1 to 4 carbon atoms. R.sub.5 may be hydrogen or one or more substituents at any of positions 3 through 6 on the pyridine ring, including alkyl of 1 to 20 carbon atoms, aryl of from 6 to 20 carbon atoms, aralkyl of from 7 to 20 carbon atoms, or alkenyl of from 2 to 20 carbon atoms, alkoxy of 1 to 20 carbon atoms, aryloxy of from 6 to 20 carbon atoms, carboxy, halogen, nitro, or sulfo. R.sub.5 m…

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