Process for the preparation of a printing plate made from a diazonium salt mixed with an organic acid from the group consisting of phosphonic, phosphinic and arsonic acids

1,125,150. Photo-sensitive materials. KALLE A.G. Dec.31, 1965 [Jan.2, 1965], No. 55431/65. Heading G2C. A light-sensitive material for use in preparing printing plates comprises a metal support coated with a diazonium salt as such or as a condensate with an aldehyde or ketone and an organic phosphonic acid (other than polyvinyl phosphonic acid) present as such or as the anion of the salt or condensate, an organic phosphonic or an organic arsenic acid. Specified phosphonic acids are chloromethane, phenyl, benzyl, phenoxymethyl which may be substituted, naphthalene and 5-nitro-naphthalene; specified arsenic acids are phenyl, butyl, substituted phenyl, alkyl, naphthalene and 4- dimethylaminophenylazo-benzene-4'-arsenic acid whereas diphenyl-phosphonic acid is the specified phosphinic acid. Phenoxymethyl-phosphonic acid formaldehyde condensate and 1,4 bis (methanephosphonic acid) 2, 3, 5, 6 tetrachlorobenzene may also be used. In the examples, an aluminium support, which may be electrolytically roughened, is coated with a diazonium salt or condensate and the organic acid imagewise exposed and developed to produce a printing plate. Alternatively the diazonium salt or condensate may have an anion of naphthalene- or 4-chlorophenoxymethylphosphonic acid or of a diphosophonic acid which may be partially esterfied.