| abstract |
A method of hardening gelatin which comprises adding thereto a compound of the following general formula (I): <IMAGE> (I) in which Y1 is CH2=CH-, ClCH2-CH2-, BrCH2-CH2-, CH3COO-CH2CH2- or ClCH2COO-CH2CH2-, R1 and R2 are H or CH3, but both of them are not CH3 at the same time, and A is one of the following groups: (1) esters <IMAGE> , OCH2Cl, <IMAGE> , <IMAGE> <IMAGE> or <IMAGE> (2) Acid anhydrides <IMAGE> or <IMAGE> (3) Amides(imides) <IMAGE> or <IMAGE> in which both R3 and R4 were acyl groups or at least one of them is an acyl group other than when R3 and R4 form a benzotriazole ring, and when one of R3 and R4 is an acyl group, the other is H or an alkyl group containing at most 4 carbon atoms; and wherein in any case, R3 and R4 may form a saturated or unsaturated carbocyclic or heterocyclic ring in combination with the nitrogen atom to which they are attached; R5, R6 and R7 are alkyl groups containing at most 4 carbon atoms, and may form a saturated or unsaturated ring, or may form a bicyclo ring; X<-> is an acid anion; R8 and R9 are a saturated or unsaturated carbocyclic or heterocyclic ring which combine with the nitrogen atom to which they are attached; R10 is an alkyl or aryl group containing at most 6 carbon atoms; R11 is an alkyl group containing at most 3 carbon atoms; R12 is an alkyl, aryl or aralkyl group containing at most 7 carbons atoms; Y2 is CH2=CH-, ClCH2-CH2-, Br-CH2CH2-, CH3COO-CH2CH2-, or ClCH2COO-CH2CH2-, and Y1 is as earlier defined. |