Dye-bleach materials and process
AssigneeMinnesota Mining and Manufacturing Company
InventorsGebran J. Sabongi, Stephen S. C. Poon
Life of this patent
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Abstract
An imagewise bleachable composition is described comprising a dye in reactive association with a mesoionic compound. The composition may be bleached by radiation at wavelengths between 200 and 1000 nm.
Claims25
A composition capable of bleaching upon exposure to radiation of selected wavelength within the range 200 to 1100 nm and/or upon heating to at least 70.degree. C., said composition comprising a bleachable dye in reactive association with a mesoionic bleaching compound wherein said mesoionic compound contains a five- or six-membered heterocycle which cannot be represented satisfactorily by any one covalent or polar structure and possesses a sextet of electrons in association with all the atoms comprising the ring.
An element capable of recording a positive image upon imagewise exposure to radiation within the wavelength range of 200 to 1100 nm or upon heating to a temperature of at least 70.degree. C., comprising a support having on at least one surface thereof a bleachable dye in reactive association with a mesoionic bleaching compound wherein said mesoionic compound contains a five- or six-membered heterocycle which cannot be represented satisfactorily by any one covalent or polar structure and possesses a sextet of electrons in association with all the atoms comprising the ring.
An element capable of recording a positive image upon imagewise exposure to radiation within the wavelength range of 200 to 1100 nm or upon heating to a temperature of at least 70.degree. C., comprising a support having on at least one surface thereof a bleachable dye in reactive association with a mesoionic bleaching compound in which the bleachable dye has the general formula:
- ##STR27## in which:
- n is an integer of 1 to 5,
- R.sup.1 to R.sup.4 are selected to provide an electron donor moiety at one end of the conjugated chain and an electron acceptor moiety at the other, and represent alkyl, aryl groups or heterocyclic rings any of which may be substituted, said group generally containing up to 14 atoms selected from C, N, O and S;
- or R.sup.1 and R.sup.2 and/or R.sup.3 and R.sup.4 may represent the necessary atoms to complete optionally substituted aryl groups or heterocyclic rings, generally containing up to 14 atoms selected from C, N, O and S.
A recording element comprising a support, one or more radiation sensitive layers and as an antihalation layer, a layer containing a bleachable dye in reactive association with a mesoionic bleaching compound wherein said mesoionic compound contains a five:
- or six-membered heterocycle which cannot be represented satisfactorily by any one covalent or polar structure and possesses a sextet of electrons in association with all the atoms comprising the ring.
Dependencies are inferred from the claim text.