公开(公告)号：US3702245A

公开(公告)日：1972-11-07

申请号：US3702245D

申请日：1971-01-04

Applicant: POLAROID CORP

Inventor： SIMON MYRON S ,  WALLER DAVID P

IPC: C09B11/04 ,  C09B11/08 ,  C09B11/24 ,  C09B11/26 ,  G03C8/48 ,  G03C5/54 ,  G03C1/40 ,  G03C7/00

CPC classification number: G03C8/48 ,  C09B11/04 ,  C09B11/08 ,  C09B11/245 ,  C09B11/26

Abstract: THIS INVENTION RELATES TO PHOTOGRAPHY, AND MORE PARTICULARLY, IT RELATES TO THE USE OF CERTAIN INDICATOR DYES DERIVED FROM PHENOLS AS OPTICAL FILTER AGENTS TO PROTECT A SELECTIVELY EXPOSED PHOTOSENSITIVE MATERIAL FROM POSTEXPOSURE FOGGING IN PHOTOGRAPHIC PROCESSES WHERE DEVELOPMENT OF THE PHOTOSENSITIVE MATERIAL IS CONDUCTED IN THE PRESENCE OF EXTRANEOUS INDIDENT LIGHT. THIS CLASS OF PHENOL INDICATOR DYES CONTAIN A RING-CLOSING MOIETY BONDED TO TWO HYDROXY-SUBSTITUTED CARBOCYCLIC ARYL RADICALS SELECTED FROM TWO P-HYDROXYPHENYL RADICALS EACH POSSESSING A HYDROGEN-BONDING GROUP ADJACENT TO THE P-HYDROXY GROUP AND TWO P-PHYDROXYNAPHTHYL RADICALS AT LEAST ONE OF THE P-HYDROXYNAPHTYL RADICALS POSSESSING A HYDROGENBONDING GROUP ADJACENT TO THE P-HYDROXY GROUP. AT A FIRST PH IN ALKALINE SOLUTION THEY HAVE A HIGHLY COLORED, LIGHTABSORBING FORM CAPABLE OF ABSORBING RADIATION WITHIN A PREDETERMINED WAVELENGTH RANGE IN THE LONGER WAVELENGTH REGION OF THE VISIBLE SPECTRUM AND AT A SECOND LESS ALKALINE PH HAVE A COLORLESS FORM THAT IS SUBSTANTIALLY NON-LIGHTABSORBING IN THE VISIBLE SPECTRUM. BY SELECTING A DYE FROM THIS CLASS WHICH IS IN ITS LIGHT-ASBORBING FORM AT THE PH AT WHICH DEVELOPMENT IS PREFORMED, PROTECTION OF THE EXPOSED PHOTOSENSITIVE MATERIAL FROM RADIATION ACTINIC THERETO IS AFFORDED WITHIN THE WAVELENGTH RANGE ABSORBED BY THE DYE AND SUBSEQUENT TO AT LEAST THE INITIAL STAGES OF DEVELOPMENT, THE DYE MAY BE RENDERED SUBSTANTIALLY COLORLESS BY ADJSTING THE PH TO PERMIT VIEWING OF THE FINAL IMAGE. IN A PREFERRED EMBODIMENT, THE PHENOL DYE OR DYES ARE USED IN CONJUNCTION WITH A SECOND DYE OR DYES HAVING A PRINCIPAL ABSORPTION IN AT LEAST A PARTIALLY DIFFERENT WAVELENGTH RANGE, AND THE PHENOL DYE(S) AND SECOND DYE(S) TOGETHER AFFORD PROTECTION OVER THE WAVELENGTH RANGE OF ABOUT 400 MM. TO 700 MM.