Method of hardening gelatin by reacting with conjugated heterocyclic compounds containing halogen atoms and water-solubilizing acid groups

Claim 1

A PROCESS FOR HARDENING GELATIN WHICH COMPRISES REACTING THE GELATIN WITH A COLORLESS COMPOUND WHICH CONTAINS AT LEAST ONE ACID GROUP IMPARTING SOLUBILITY IN WATER, WHICH GROUP IS BOUND TO A CARBON ATOM, AT LEAST ONE HETEROCYCLIC SIX-MEMBERED RING CONSISTING OF 3 TO 4 CARBON ATOMS AND 2 TO 3 NITROGEN ATOMS AND HAVING THREE CONJUGATED DOUBLE BONDS, AND AT LEAST ONE HALOGEN ATOM BOUND TO ONE OF THE RING CARBON ATOMS OF THE HETEROCYCLIC RING, THE CARBON ATOMS IN SAID HETEROCYCLIC RING HAVING SUBSTITUENTS SELECTED FROM THE GROUP CONSISTING OF THE AFORESAID ACID GROUP, A HALOGEN ATOM, A SULFOPHENYLAMINO RADICAL, A SULFONAPHTHYLAMINO RADICAL, A SULFATOALKYLAMINO RADICAL, A SULFOPHENOXY RADICAL, A HYDROXYALKYLAMINO RADICAL, A PRIMARY AMINO GROUP, A B-(6-CHLORO-4: SULFOPHENYLAMINO-1,3,5-TRIAZINE-2- YLAMINO)-ETHYLAMINO RADICAL, A B-(6-CHLORO-4-SULFOPHENYLAMINO-1,3,5-TRIAZINE2-YLAMINO)-PHENYLAMINO RADICAL, AND A B-(6-CHLORO-4SULFOPHENOXY -1,3,5 - TRIAZINE- 2- YLAMINO)-ETHYLAMINO RADICAL.