发明授权
US4298676A Optical filter agents and photographic products and processes containing
same
失效
光学过滤剂和含有它们的摄影产品和方法
- 专利标题: Optical filter agents and photographic products and processes containing same
- 专利标题(中): 光学过滤剂和含有它们的摄影产品和方法
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申请号: US89559申请日: 1979-10-29
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公开(公告)号: US4298676A公开(公告)日: 1981-11-03
- 发明人: Derek H. R. Barton , Irena Y. Bronstein-Bonte , Lloyd D. Taylor
- 申请人: Derek H. R. Barton , Irena Y. Bronstein-Bonte , Lloyd D. Taylor
- 申请人地址: MA Cambridge
- 专利权人: Polaroid Corporation
- 当前专利权人: Polaroid Corporation
- 当前专利权人地址: MA Cambridge
- 主分类号: G03C8/48
- IPC分类号: G03C8/48 ; G03C1/40 ; G03C1/10 ; G03C1/84 ; G03C5/54
摘要:
Optical filter agents and photographic products and processes using same are disclosed. The optical filter agents are pH-sensitive hydrazone compounds conforming to the following structural formula: ##STR1## where R is any group which can provide a double bond for conjugation with the ##STR2## portion of the compound to provide light-absorbing capability or color for the agent at a pH above its pKa, X is a substituent of R providing at least one electron-withdrawing group and each R' can be defined as any substituent that does not impair the light-absorbing capacity of the compound at a pH above the pKa thereof. The pH-sensitive optical filter agents have a highly colored light-absorbing form at a pH above the pKa and are substantially non-absorbing at a pH below the pKa. The pH-sensitive optical filter agents are useful in photographic film units and processes for the protection of photoexposed photosensitive elements against the occurence of fogging during in-light development.
公开/授权文献
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