Type of modified gelatin and its use in a DTR material

Photographic material comprising a support, a photosensitive hydrophilic layer, and optionally one or more other hydrophilic layer(s), characterized in that at least one of said hydrophilic layer(s) contains modified gelatin according to general formula (I) or (II):

• Gel--CO--NR.sup.1 --L--X (I)
• Gel--CO--NR.sup.1 --Z.sub.(X).sbsb.m (II)
• wherein
• Gel is a gelatin polypeptide, --CO--is a carbonyl group from part of the free carboxyl groups originally present in an aspartic acid or glutamic acid moiety in said gelatin polypeptide,
• R.sup.1 represents hydrogen, alkyl, aryl, or cycloalkyl,
• X is a moiety selected from the group consisting of:
• --SO.sub.3 M, --OSO.sub.3 M, --SSO.sub.3 M, --OPO(OH).sub.2, --OPO(OH)(OR.sup.2), --PO(OH).sub.2, --PO(OH)(OR.sup.2),
• wherein M is a hydrogen or a cation, and R.sup.2 is lower alkyl,
• L represents an alkykene moiety, which can be further substituted by alkyl, aryl, or cycloalkyl,
• one or more pairs of said substituents on said alkylene moiety can combine together to form a ring, and wherein said alkylene moiety can be interrupted by one or more hetero atoms;
• Z represents the atoms to form a cycloaliphatic, aromatic carbocyclic, or aromatic or non-aromatic heterocyclic ring,
• m is 1 to 4.