Direct positive silver halide photographic materials

Claim 1

A direct positive silver halide light-sensitive material capable of forming direct positive images comprising a support having coated thereon at least one internal image silver halide emulsion layer, wherein said light-sensitive material contains at least one hydrophilic colloid layer containing heterocyclic quaternary salt compound represented by formula (I) in an amount of about 5mg to about 1000mg per 1 mol of silver halide sufficient so that said compound acts as a fogging agent in the silver halide photographic emulsion ##STR7## wherein Z is an atomic group necessary for completing a 5- or 6-membered heterocyclic nucleus selected from the group consisting of a thiazole nucleus, a benzothiazole nucleus, a naphthothiazole nucleus, a selenazole nucleus, a benzoselenazole nucleus, a naphthoselenozole nucleus, an oxazole nucleus, a benzoxazole nucleus, a naphthoxazole nucleus, a benzimidazole nucleus, a pyridine nucleus, a quinoline nucleus and an indolenine nucleus, R 1 is an aliphatic group, having 1 to 8 carbon atoms, which aliphatic group is selected from the group consisting of an unsubstituted alkyl group, a sulfo substituted alkyl group, a sulfoalkoxyalkyl group, a hydroxysulfoalkyl group, a carboxyalkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an acyloxyalkyl group, a dialkylaminoalkyl group, a sulfatoalkyl group, an aralkyl group, and a vinylmethyl group, R 2 is a hydrazonoalkyl group having 1 to 8 carbon atoms in the alkyl moiety thereof, X⊖ is an anion, and n is 1 or 2, when n is 1 the compound forms an intermolecular salt.