Reversible redox-controlled imaging method
AssigneePolaroid Corporation
InventorsMyron S. Simon, Marcis M. Kampe, David P. Waller
Life of this patent
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Abstract
A novel class of N-substituted triarylmethane sulfonamides is provided which undergo reversible oxidation into colored form and reversible reduction of the oxidized form into colorless form. Preferred embodiments comprise xanthene sulfonamides having N-aryl substituents, e.g., hydroquinone substituents. These compounds possess redox potentials ranging between about +200 to -500 millivolts and thus are useful as dyes for producing photographic, photothermographic, thermal, and pressure-induced images, as well as being useful as redox indicators in a wide variety of biological and chemical reactions.
Claims10
A method of forming color which comprises contacting an oxidizing agent and a substantially color less compound of the formula ##STR38## wherein B is a carbocyclic ring or carbocyclic rings;
- T is a 5- or 6-membered ring;
- Y is a carbocyclic moiety selected from ##STR39## wherein E, positioned ortho or para to said --OH group, is selected form --OH, --NH.sub.2, --NHR', --NR'R" and --NHSO.sub.2 R' wherein R' and R" each are lower alkyl groups having 1 to 6 carbon atoms or aralkyl wherein said aralkyl includes an aryl portion which may be substituted with alkyl groups having 1 to 24 carbon atoms, and E' is hydrogen or a monovalent groups that is substituted on one of the remaining carbon atoms of said carbocyclic moiety;
- G and G' each are hydroxy or methoxy, provided one is hydroxy and the other is methoxy;
- and Z and Z' taken individually represent the moieties to complete the chromophoric system of a triarylmethane dye when said N-containing ring, T, is open and Z and Z' taken together represent the bridged moieties to complete the chromophoric system of a bridged triarylmethane dye when said N-containing ring, T, is open to give a colored compound of the formula ##STR40## wherein B, Z and Z' have the same meaning given above and Y' represents the quinoid form of Y.
A method of forming an image which comprises contacting imagewise
- (a) an image dye-providing compound selected from ##STR41## wherein B is a carbocyclic ring or carbocyclic rings;
- T is a 5- or 6-membered ring;
- Y is a carbocyclic moiety selected from ##STR42## wherein E, positioned ortho or para to said --OH group, is selected from --OH, --NH.sub.2, --NHR', NR'R" and --NHSO.sub.2 R' wherein R' and R" each are lower alkyl groups having 1 to 6 carbon atoms or aralkyl wherein the said aralkyl includes an aryl portion which may be substituted with alkyl groups having 1 to 24 carbon atoms, and E' is hydrogen or a monovalent group that is substituted on one of the remaining carbon atoms of said carbocyclic moiety;
- G and G' each are hydroxy ormethoxy, provided one is hydroxy and the other is methoxy;
- and Z and Z' taken individually represent the moieties to complete the chromophoric system of a triarylmethane dye when said N-containing ring, T, is open and Z and Z' taken together represent the bridged moieties to complete the chromophoric system of a bridged triarylmethane dye when said N-containing ring, T, is open;
- and Y' represents the quinoid form of Y;
- and
- (b) a developing material capable of either oxidizing said Y moiety whereby said compound is rendered colored imagewise or reducing said Y' moiety whereby said compound is rendered colorless imagewise.
A method for generating a color change comprising contacting a compound selected from ##STR47## wherein B is a carbocyclic ring or carbocyclic rings;
- T is a 5- or 6-membered ring;
- Y is a carbocyclic moiety selected from ##STR48## wherein E, positioned ortho or para to said --OH group, is selected from --OH, --NH.sub.2, --NHR', --NR'R" and --NHSO.sub.2 R' wherein R' and R" each are lower alkyl groups having 1 to 6 carbon atoms or aralkyl wherein said aralkyl includes an aryl portion which may be substituted with alkyl group having 1 to 24 carbon atoms, and E' is hydrogen or a monovalent group that is substituted on one of the remaining carbon atoms of said carbocyclic moiety;
- G and G' each are hydroxy or methoxy, provided one is hydroxy and the other is methoxy;
- and Z and Z' taken individually represent the moieties to complete the chromophoric system of a triarylmethane dye when said N-containing ring, T, is open and Z and Z' taken together represent the bridged moieties to complete the chromophoric system of a bridged triarylmethane dye when said N-containing ring, T, is open;
- and Y' represents the quinoid form of Y;
- with a material capable of either oxidizing said Y moiety whereby said compound is rendered colored or reducing said Y.varies. moiety whereby said compound is rendered colorless.
Dependencies are inferred from the claim text.