Process of hardening protein-containing photographic layers with a mixture of a carboxyl group-activating, low molecular weight compound and a carboxyl group-activating polymer

Claim 2

A process for treating silver halide photographic materials which include a protein-containing layer to harden such layer which comprises the step of applying over such layer a layer comprising a mixture of a low molecular weight, fast-acting, carboxyl group-activating hardening agent with a larger amount of a film-forming, hydrophilic, polymeric, fast-acting hardening agent carrying at least one carboxyl group-activating carbodiimide substituent, said low molecular weight hardening agent being selected from the group consisting of carbamoylpyridinium salts, carbamoyloxypyridinium salts, isoxazolium salts, dihydroquinoline compounds, and carbodiimides.

Claim 3

A process according to claim 1, wherein the layer to be hardened contains gelatin.

Claim 4

A process according to claim 1, wherein the low molecular weight, fast-acting, carboxyl group-activating hardening agent corresponds to the general formulas: X.sup.1 - N ═ C ═ N - X.sup.2 wherein each of X 1 and X 2 (same or different) represents alkyl of 1 to 6 carbon atoms, cyclohexyl, alkoxyalkyl, allyl, phenyl, tolyl, morpholinoalkyl, pyridylalkyl, or dialkylaminoalkyl, or X 1 represents alkyl, alkoxyalkyl or pyridylalkyl and X 2 represents the group ##STR33## wherein X 3 is an alkylene group of 1 to 5 carbon atoms, each of X 4 and X 5 is alkyl of 1 to 3 carbon atoms, or X 4 and X 5 together form with the N atom a six-membered heterocyclic ring, X 6 is hydrogen or lower alkyl and X is an anion.

Claim 5

A process according to claim 3, wherein the low molecular weight, fast-acting, carboxyl group-activating hardening agent is N-methyl-N'-(3-dimethylaminopropyl)carbodiimide.HCl.

Claim 6

A process according to claim 1, wherein the polymeric fast-acting hardening agent comprises in its structure recurring units corresponding to the formula: ##STR34## wherein A represents a single chemical bond or a group according to one of the formulae: ______________________________________ CO . O,CONH, ##STR35## ##STR36## ##STR37## or ##STR38## ______________________________________ with R' and R" representing a methyl or ethyl group, R"' representing an alkylene group of 1 to 4 carbon atoms, and X representing an anion, R 1 represents a hydrogen atom or a methyl group, and each of R 2 and R 3 represents an alkyl group of 1 to 4 carbon atoms, and R 4 represents a phenylene or an alkylene group of 1 to 4 carbon atoms.

Claim 7

A process according to claim 7, wherein the polymeric, fast-acting hardening agent corresponds to the structural formula: ##STR39## wherein x, y, z, and w are 26.2, 52.6, 7.2, and 14.0 mole % respectively.

Claim 8

A process according to claim 1, wherein the polymeric, fast-acting hardening agent comprises in its structure recurring units corresponding to the formula: ##STR40## wherein each of R 2 and R 3 represents an alkyl group of 1 to 4 carbon atoms, R' and R" represent a methyl or ethyl group, and X represents an anion.

Claim 9

A process according to claim 1, wherein the coating composition comprises 4 to 20 parts by weight of said low molecular weight, fast-acting, carboxyl group-activating hardening agent and 80 to 96 parts by weight of said polymeric fast-acting hardening agent carrying carboxyl group-activating substituents.

Claim 10

A process according to claim 1, wherein the applied coating composition forms after drying a layer of 0.2 to 5 μm in thickness.

Claim 11

A silver halide photographic material containing at least one protein-containing layer and a superposed contacting layer comprising a mixture of a low molecular weight, fast-acting, carboxyl group-activating hardening agent with a larger amount of a film-forming, hydrophilic, polymeric, fast-acting hardening agent carrying at least one carboxyl group-activating carbodiimide substituent, said low molecular weight hardening agent being selected from the group consisting of carbamoylpyridinium salts, carbamoyloxypyridinium salts, isoxazolium salts, dihydroquinoline compounds, and carbodiimides.

Claim 12

A silver halide photographic material containing at least one protein-containing layer and a superposed contacting layer comprising a mixture of a low molecular weight, fast-acting, carboxyl group-activating hardening agent with a larger amount of a film-forming, hydrophilic, polymeric, fast-acting hardening agent carrying at least one carboxyl group-activating carbodiimide substituent, said low molecular weight hardening agent being selected from the group consisting of carbamoylpyridinium salts, carbamoyloxypyridinium salts, isoxazolium salts, dihydroquinoline compounds, and carbodiimides.

Claim 13

A photographic material according to claim 10, wherein the protein containing layer comprises gelatin.