Thermal imaging method
AssigneePolaroid Corporation
InventorErnest W. Ellis
Life of this patent
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Abstract
A method of thermal imaging is provided which comprises heating imagewise a layer of a colored di- or triarylmethane compound possessing within its di- or triarylmethane structure an aryl group substituted in the ortho-position to the meso carbon atom with a group comprising a thermally unstable urea moiety which fragments upon heating to provide a new group that bonds to the meso carbon atom whereby the di- or triarylmethane compound is rendered ring-closed and colorless in an imagewise pattern corresponding to said imagewise heating.
Claims16
A heat-sensitive element comprising a support carrying at least one imaging layer of a colored di- or triarylmethane imaging compound possessing in its di- or triarylmethane structure an aryl group substituted in the ortho-position to the meso carbon atom with a thermally unstable urea moiety, said urea moiety undergoing a unimolecular fragmentation reaction upon heating to provide a new group in said ortho position that bonds to said meso carbon atom to form a ring having 5 or 6 members whereby said di- or triarylmethane compound becomes ring-closed and rendered colorless.
A method of thermal imaging which comprises heating imagewise a heat-sensitive element comprising a support carrying at least one imaging layer of a colored di- or triarylmethane compound possessing in its di- or triarylmethane structure an aryl group substituted in the ortho-position to the meso carbon atom with a thermally unstable urea moiety, said urea moiety being capable of undergoing a unimolecular fragmentation reaction upon heating to provide a new group in said ortho position that bonds to said meso carbon atom to form a ring having 5 or 6 members whereby said di- or triarylmethane compound becomes ring-closed and rendered colorless in an imagewise pattern corresponding to said imagewise heating.
Dependencies are inferred from the claim text.