Claims
- 1. A heat-sensitive element comprising a support carrying as color-forming co-reactants in the same or different layers (a) a substantially colorless di- or triarylmethane compound possessing on the meso carbon atom within its di- or triarylmethane structure an aryl group substituted in the ortho position with a nucleophilic moiety which is ring-closed on the meso carbon atom and (b) an electrophilic reagent which upon heating and contacting said di- or triarylmethane compound undergoes a bimolecular nucleophilic substitution reaction with said nucleophilic moiety to form a colored, ring-opened di- or triarylmethane compound.
- 2. A heat-sensitive element as defined in claim 1 wherein an infra-red absorber is associated with at least one of said color-forming co-reactants (a) and (b) for absorbing radiation at wavelengths above 700 nm and transferring said absorbed radiation as heat to said reactants.
- 3. A heat-sensitive element as defined in claim 1 wherein a black compound is formed upon reaction of said (b) with said (a).
- 4. A heat-sensitive element as defined in claim 1 wherein said element comprises at least two sets of said color-forming co-reactants (a) and (b).
- 5. A heat-sensitive element as defined in claim 3 wherein an infra-red absorber is associated with each set of said color-forming co-reactants for absorbing radiation at wavelengths above 700 nm and transferring said absorbed radiation as heat to at least one of said co-reactants of each said set.
- 6. A heat-sensitive element as defined in claim 5 wherein said infra-red absorbers selectively absorb radiation at different predetermined wavelengths above 700 nm.
- 7. A heat-sensitive element as defined in claim 5 wherein said infra-red absorbers absorb radiation at the same wavelength above 700 nm.
- 8. A heat-sensitive element as defined in claim 5 which additionally includes a thermal isolation layer between adjacent sets of said color-forming reactants.
- 9. A heat-sensitive element as defined in claim 8 wherein three sets of said color-forming co-reactants are carried on said support for forming a cyan image, a magenta image and a yellow image, respectively.
- 10. A method of thermal imaging which comprises heating imagewise as color-forming co-reactants at least one of (a) a substantially colorless di- or triarylmethane compound in a layer on a support, said di- or triarylmethane compound possessing on the meso carbon atom within its di- or triarylmethane structure an aryl group substituted in the ortho position with a nucleophilic moiety which is ring-closed on the meso carbon atom and (b) an electrophilic reagent in a layer on the same or a separate support, which reagent upon contacting said colorless di- or triarylmethane compound undergoes a bimolecular nucleophilic substitution reaction with said nucleophilic moiety to form a colored, ring-opened di- or triarylmethane compound different from said (a), said imagewise heating effecting contact between said (a) and (b) to bring about said bimolecular reaction whereby said colored di- or triarylmethane compound is formed in an imagewise pattern corresponding to said imagewise heating.
- 11. A method of thermal imaging as defined in claim 10 wherein an infra-red absorber is associated with at least one of said color-forming co-reactants (a) and (b) for absorbing radiation at wavelengths above 700 nm and transferring said absorbed radiation as heat to said reactant, said imagewise heating being effected by imagewise exposure to infra-red radiation at a wavelength strongly absorbed by said infra-red absorber.
- 12. A method of thermal imaging as defined in claim 10 wherein said color-forming co-reactants (a) and (b) are carried on the same support in the same or different layers.
- 13. A method of thermal imaging as defined in claim 12 wherein at least two sets of said color-forming co-reactants (a) and (b) are carried on said support.
- 14. A method of thermal imaging as defined in claim 13 which additionally includes a thermal isolation layer between adjacent sets of said color-forming co-reactants.
- 15. A method of thermal imaging as defined in claim 13 wherein said infra-red absorber is associated with each set of said color-forming co-reactants for absorbing radiation at wavelengths above 700 nm and transferring said absorbed radiation as heat to at least one of said (a) and (b) of each set of co-reactants, said infra-red absorbers associated with each set of co-reactants selectively absorbing infra-red radiation at different predetermined wavelengths above 700 nm, said imagewise heating being effected by imagewise exposure to a plurality of laser beam sources emitting infra-red radiation at the respective wavelengths selectively absorbed by said infra-red absorbers.
- 16. A method of thermal imaging as defined in claim 13 wherein an infra-red absorber is associated with each set of color-forming co-reactants for absorbing radiation at wavelengths above 700 nm and transferring said absorbed radiation as heat to at least one of said (a) and (b) of each set of co-reactants, said infra-red absorbers associated with each set of co-reactants absorbing infra-red radiation at the same or at different predetermined wavelengths above 700 nm, said imagewise heating being effected by adjusting the depth of focus of a laser beam source emitting radiation at the wavelength absorbed by said infra-red absorber.
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of copending application Ser. No. 740,888 filed June 3, 1985 abandoned.
US Referenced Citations (9)
Foreign Referenced Citations (1)
Number |
Date |
Country |
55-87553 |
Jul 1980 |
JPX |
Continuation in Parts (1)
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Number |
Date |
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Parent |
740888 |
Jun 1985 |
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