Stabilizers for use in substantially light-insensitive thermographic recording materials

Abstract

A substantially light-insensitive black and white monosheet thermographic recording material comprising a support and a thermosensitive element, said thermosensitive element containing a substantially light-insensitive organic silver salt, an organic reducing agent therefor in thermal working relationship therewith, at least one binder and at least one stabilizer represented by formula (I): wherein R, R, Rand Rare independently selected from the group consisting of a hydrogen atom, halogen atoms and aliphatic, alkoxy, nitro, acyl, sulfonyl, nitrile, alkaryl, aryl, amino, thioalkyl, aldehyde, urea, —O—(C═O)-alkyl, —O—(C═O)-aryl, —O—(C═O)—O-alkyl, —O—(C═O)—O-aryl, —NH—(C═O)-alkyl, —NH—(C═O)-aryl, —(C═O)—NH-alkyl, —(C═O)—NH-aryl, —NH—(SO)-alkyl, —NH—(SO)-aryl, —(SO)—NH-alkyl, —(SO)—NH-aryl groups; X is represented by -A(-M)or is selected from the group consisting of substituted aliphatic groups, unsubstituted aliphatic groups, substituted cycloaliphatic groups, unsubstituted cycloaliphatic groups, substituted aromatic groups and unsubstituted aromatic groups where in each of said groups one or more of the chain or ring carbon atoms may be substituted by one of more atoms selected from the group consisting of S, O, Si, N and P atoms; n is 2, 3 or 4; A is selected from the group consisting of substituted aliphatic groups, unsubstituted aliphatic groups, substituted cycloaliphatic groups, unsubstituted cycloaliphatic groups, substituted aromatic groups and unsubstituted aromatic groups where in each of said groups one or more of the chain or ring carbon atoms may be substituted by one of more atoms selected from the group consisting of S, O, Si, N and P atoms; each (-M) is independently a substituted or unsubstituted group selected from the group consisting of -(2-S-imidazole) groups and -(2-S-imidazole) groups annelated with an aromatic ring system, the optional substituents for -M being selected from the group consisting of halogen atoms and aliphatic, alkoxy, nitro, acyl, sulfonyl, nitrile, alkaryl and aryl groups.