Light-sensitive coating for pre-sensitized plates intended for offset printing and for engraved wiring of printed circuits

Claim 2

A LIGHT-SENSITIVE COMPOSITION FOR PRE-SENSITIZED PLATES INCLUDED FOR OFFSET PRINTING AND FOR ENGRAVED WIRING FOR PRINTED CIRCUITS, SAID COMPOSITION COMPRISING THE PRODUCTS OF THE REACTION OF AN ANHYDRIDE, OF DIAZO-NAPHTHOL-SULPHONIC ACID AND OF AT LEAST ONE ISOMER OF ANHYDRIDE, WITH A PARA-DIAZO-DIPHENYLAAMINE AND A NOVOLAK RESIN.

Claim 3

IN A METHOD OF PREPARING OF A LIGHT-SENSITIVE COATING FOR PRE-SENSITIZED PLATES INTENDED FOR ENGRAVED WIRING FOR PRINTED CIRCUITS, SAID METHOD COMPRISING: (A) DISSOLVING IN AN ALCOHOLIC MEDIUM AN ANHYDRIDE OF MER OF SAID ANHYDRIDE; (B) DISSOLVING IN SAID ALCHOLIC MEDIUM A PARA-DIAZOMER OF SAID ANHYDRIDE; DIPHENYLAMINE WHEREBY THERE IS PRODUCED IN THE COLD STATE A REACTION BETWEEN THE PARA-DIAZO-DIPHENYLAMINE AND PART OF SAID ANHYDRIDES OF DIAZO-NAPHTHOLSULFONIC ACID; (C) DISSOLVING IN SAID ALCHOLIC MEDIUM A NOVOLAK RESIN, WHEREBY THERE IS OBTAINED AN ALCOHOL COATING VARNISH COMPRISING REACTIVE CONSTITUENTS; (D) COATING A METALLIC SURFACED PLATE WITH SAID ALCOHOL VARNISH; (E) HEAT TREATING SAID VARNISH COATING WHEREBY THERE IS CAUSED A SLIGHT POLY-CONDENSATION OF SAID NOVOLAK RESN AND A CHEMICAL REACTION WITH THE UNREACTED COMPONENTS OF SAID ANHYDRIDES OF DIAZO-NAPHTHOL-SULPHONIC ACID WHICH ARE IN THE FREE STATE IN SAID MEDIUM TO PROVIDE A SENSITIVE SURFACE; (F) APPLYING A POSITIVE FILM OF THE DESIGN TO BE REPRODUCED AGAINST THE SENSITIVE SURFACE; (G) EXPOSING SAID SURFACE TO ULTRA-VIOLTE RAYS; (H) DEVELOPING THE SENSITIVE SURFACE BY MEANS OF A DILUTE AQUEOUS SOLUTION OF TRI-SODIUM PHOSPHATE HAVING A CONCENTRATION, IN CRYSTALLIZED PRODUCT, OF 0.2% TO 10%; (I) TREATING THE PLATE WITH A SOLVENT OF COPPER, COMPRISING AN AQUEOUS SOLUTION OF FERRIC CHLORIDE AT 36* BUAME; (J) DISSOLVING IN AN APPROPRIATE SOLVENT, COMPRISING ETHYL ALCOHOL, THE NON-EXPOSED COATING WHICH COVERS THE UNATTACHED COPPER OF THE PLATE.

Claim 4

IN A METHOD OF PREPARING OF A LIGHT-SENSITIVE COATING FOR PRE-SENSITIZED PLATES INTENDED FOR ENGRAVED WIRING FOR PRINTED CIRCUITS, SAID METHOD COMPRISING: (A) DISSOLVING IN AN ALCOHOLIC MEDIUM AN ANHYDRIDE OF MER OF SAID ANHYDRIDE; (B) DISSOLVING IN SAID ALCHOLIC MEDIUM A PARA-DIAZOMER OF SAID ANHYDRIDE; DIPHENYLAMINE WHEREBY THERE IS PRODUCED IN THE COLD STATE A REACTION BETWEEN THE PARA-DIAZO-DIPHENYLAMINE AND PART OF SAID ANHYDRIDES OF DIAZO-NAPHTHOLSULFONIC ACID; (C) DISSOLVING IN SAID ALCHOLIC MEDIUM A NOVOLAK RESIN, WHEREBY THERE IS OBTAINED AN ALCOHOL COATING VARNISH COMPRISING REACTIVE CONSTITUENTS; (D) COATING A METALLIC SURFACED PLATE WITH SAID ALCOHOL VARNISH; (E) HEAT TREATING SAID VARNISH COATING WHEREBY THERE IS CAUSED A SLIGHT POLY-CONDENSATION OF SAID NOVOLAK RESN AND A CHEMICAL REACTION WITH THE UNREACTED COMPONENTS OF SAID ANHYDRIDES OF DIAZO-NAPHTHOL-SULPHONIC ACID WHICH ARE IN THE FREE STATE IN SAID MEDIUM TO PROVIDE A SENSITIVE SURFACE; (F) APPLYING A POSITIVE FILM OF THE DESIGN TO BE REPRODUCED AGAINST THE SENSITIVE SURFACE; (G) EXPOSING SAID SURFACE TO ULTRA-VIOLTE RAYS; (H) DEVELOPING THE SENSITIVE SURFACE BY MEANS OF A DILUTE AQUEOUS SOLUTION OF TRI-SODIUM PHOSPHATE HAVING A CONCENTRATION, IN CRYSTALLIZED PRODUCT, OF 0.2% TO 10%; (I) TREATING THE PLATE WITH A SOLVENT OF COPPER, COMPRISING AN AQUEOUS SOLUTION OF FERRIC CHLORIDE AT 36* BUAME; (J) DISSOLVING IN AN APPROPRIATE SOLVENT, COMPRISING ETHYL ALCOHOL, THE NON-EXPOSED COATING WHICH COVERS THE UNATTACHED COPPER OF THE PLATE.