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US 5,773,170 AGranted
UV-absorbing media bleachable by IR-radiation
AssigneeMinnesota Mining and Manufacturing Company
InventorsRanjan C. Patel, Robert J. D. Nairne
Life of this patent
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Abstract
An image-forming element comprising a substrate, and an image-forming medium comprising (a) a compound absorbing at a first wavelength in the UV/blue region and (b) a dye absorbing at a second wavelength which is longer than the first wavelength, irradiation at said second wavelength bleaching absorption of said compound at said first wavelength, said element being free of thermally unstable urea and/or carbamate molecules.
Claims35
An image-forming element comprising a substrate, and an image-forming medium comprising
- (a) a compound absorbing at a first wavelength in the UV/blue region which has the general formula III ##STR13## wherein R.sup.3 and R.sup.4 are independently members selected from the group consisting of H, alkyl, aryl, alicyclic, and heterocyclic groups:
- each R.sup.5 and each R.sup.6 are independently members selected from the group consisting of alkyl, aryl, alicyclic and heterocyclic groups;
- and
- Z is a member selected from the group consisting of O and a covalent bond;
- and
- (b) a dye absorbing at a second wavelength which is longer than the first wavelength, wherein irradiation of said dye absorbing at said second wavelength causes bleaching of the absorption of said compound of formula III.
3 more elements
A method of imaging which comprises:
- (i) providing an image-forming element comprising a substrate, and an image-forming medium comprising:
- (a) a compound absorbing at a first wavelength in the UV/blue region which has the general formula III ##STR16## wherein R.sup.3 and R.sup.4 are independently members selected from the group consisting of H, alkyl, aryl, alicyclic, and heterocyclic groups;
- each R.sup.5 and each R.sup.6 are independently members selected from the group consisting of alkyl, aryl, alicyclic and heterocyclic groups;
- and
- Z is a member selected from the group consisting of O and a covalent bond;
- and
- (b) a dye absorbing at a second-wavelength which is longer than the first wavelength, wherein irradiation of said dye absorbing at said second wavelength causes bleaching of tee absorption of said compound of formula III;
- and
- (ii) image-wise exposing said image-forming element to radiation at said second wavelength.
6 more elements
An imaging method which comprises the steps of:
- (i) providing a first imaging element comprising an image-forming element comprising a substrate, and an image-forming medium comprising;
- (a) a compound absorbing at a first wavelength in the UV/blue region which has the general formula III ##STR17## wherein R.sup.3 and R.sup.4 are independently members selected from the group consisting of H, alkyl, aryl, alicyclic, and heterocyclic groups;
- each R.sup.5 and each R.sup.6 are independently members selected from the group consisting of alkyl, aryl, alicyclic and heterocyclic groups;
- and
- Z is a member selected from the group consisting of O and a covalent bond;
- and
- (b) a dye absorbing at a second wavelength which is longer than the first wavelength, wherein irradiation of said dye absorbing at said second wavelength causes bleaching of the absorption of said compound of formula III;
- (ii) exposing said first element to a pattern of radiation at said second wavelength;
- (iii) assembling said exposed first element in contact with a second imaging element which is sensitive to light of the first wavelength;
- and
- (iv) exposing the assembly to a source of light of the first wavelength with the first imaging element closest to the source.
8 more elements
A method of forming an image comprising the steps of:
- (i) providing an imaging element comprising an image-forming element comprising;
- a substrate;
- an image-forming medium comprising;
- (a) a compound absorbing at a first wavelength in the UV/blue region which has the general formula III ##STR18## wherein R.sup.3 and R.sup.4 are independently members selected from the group consisting of H, alkyl, aryl, alicyclic, and heterocyclic groups;
- each R.sup.5 and each R.sup.6 are independently members selected from the group consisting of alkyl, aryl, alicyclic and heterocyclic groups;
- and
- Z is a member selected from the group consisting of O and a covalent bond;
- and
- (b) a dye absorbing at a second wavelength which is longer than the first wavelength, wherein irradiation of said dye absorbing at said second wavelength causes bleaching of he absorption of said compound of formula III;
- and
- a second image-forming medium which is UV sensitive wherein the first image-forming medium comprising components (a) and (b) is located such that an image formed therein may act as an exposure mask for said second image-forming medium;
- (ii) exposing the element to a pattern of radiation at said second wavelength;
- (iii) exposing the element to a source of radiation of the first wavelength;
- and
- (iv) processing the element to develop an image in said second image forming medium.
12 more elements
An imaging method comprising the steps of:
- (i) providing a first imaging element comprising a substrate and an imaging medium comprising;
- (a) a compound absorbing at a first wavelength in the UV/blue region which has the general formula III ##STR19## wherein R.sup.3 and R.sup.4 are independently members selected from the group consisting of H, alkyl, aryl, alicyclic, and heterocyclic groups;
- each R.sup.5 and each R.sup.6 are independently members selected from the group consisting of alkyl, aryl, alicyclic and heterocyclic groups;
- and
- Z is a member selected from the group consisting of O and a covalent bond;
- and
- (b) a dye absorbing at a second wavelength which is longer than the first wavelength, wherein irradiation of the medium at said second wavelength causes bleaching o absorption of the compound (a) at the first wavelength, said imaging medium additionally comprising a thermally transferable colourant;
- (ii) assembling in contact with a receptor said first imaging element;
- (iii) exposing the assembly to a pattern of radiation at said second wavelength so as to cause thermal transfer of colourant to the receptor in irradiated areas and to bleach absorption of the compound (a) at said first wavelength;
- (iv) separating said first imaging element from the receptor and assembling said first imaging element in contact with a second imaging element which is sensitive to radiation of the first wavelength;
- and
- (v) exposing the assembly to a source of radiation at said first wavelength.
9 more elements
An image-forming element comprising a substrate, and an image-forming medium comprising:
- (a) a compound absorbing at a first wavelength in the UV/blue region which has the general formula II ##STR20## wherein each R.sup.2 is independently a member selected from the group consisting of an alkyl group and an aryl group of up to 10 ring carbon atoms;
- and
- M.sup.+ represents a cation;
- and
- (b) a dye absorbing at a second wavelength which is longer than the first wavelength, wherein irradiation at said second wavelength causes bleaching of the absorption of said compound of formula II.
2 more elements
A method of imaging which comprises:
- (i) providing an image-forming element comprising a substrate, and an image-forming medium comprising:
- (a) a compound absorbing at a first wavelength in the UV/blue region which has the general formula II ##STR22## wherein each R.sup.2 is independently a member selected from the group consisting of an alkyl group and an aryl group of up to 10 ring carbon atoms;
- and
- M.sup.+ represents a cation;
- and
- (b) a dye absorbing at a second wavelength which is longer than the first wavelength wherein irradiation of said dye absorbing at said second wavelength causes bleaching of the absorption of said compound of formula II;
- and
- (iii) image-wise exposing said image-forming element to radiation at said second wavelength.
5 more elements
An imaging method which comprises the steps of:
- (i) providing a first imaging element comprising an image-forming element comprising a substrate, and an image-forming medium comprising:
- (a) a compound absorbing at a first wavelength in the UV/blue region which has the general formula II ##STR23## wherein each R.sup.2 is independently a member selected from the group consisting of an alkyl group and an aryl group of up to 10 ring carbon atoms;
- and
- M.sup.+ represents a cation;
- and
- (b) a dye absorbing at a second wavelength which is longer than the first wavelength, wherein irradiation of said dye absorbing at said second wavelength causes bleaching of the absorption of said compound of formula II;
- (ii) exposing said first element to a pattern of radiation at said second wavelength;
- (iii) assembling said exposed first element in contact with a second imaging element which is sensitive to light of the first wavelength;
- and
- (iv) exposing the assembly to a source of light of the first wavelength with the first imaging element closest to the source.
7 more elements
A method of forming an image comprising the steps of:
- (i) providing an imaging element comprising an image-forming element comprising:
- a substrate;
- an image-forming medium comprising:
- (a) a compound absorbing at a first wavelength in the UV/blue region which has the general formula II ##STR24## wherein each R.sup.2 is independently a member selected from the group consisting of an alkyl group and an aryl group of up to 10 ring carbon atoms;
- and
- M.sup.+ represents a cation;
- and
- (b) a dye absorbing at a second wavelength which is longer than the first wavelength, wherein irradiation of said dye absorbing at said second wavelength causes bleaching of the absorption of said compound of formula II;
- and
- a second image-forming medium which is UV sensitive wherein the first image-forming medium comprising components (a) and (b) is located such that an image formed therein may act as an exposure mask for said second image-forming medium;
- (ii) exposing the element to a pattern of radiation at said second wavelength;
- (iii) exposing the element to a source of radiation of the first wavelength;
- and
- (iv) processing the element to develop an image in said second image-forming medium.
11 more elements
An imaging method comprising the steps of:
- (i) providing a first imaging element comprising a substrate and an imaging medium comprising:
- (a) a compound absorbing at a first wavelength in the UV/blue region which has the general formula II ##STR25## wherein each R.sup.2 is independently a member selected from the group consisting of an alkyl group and an aryl group of up to 10 ring carbon atoms;
- and
- M.sup.+ represents a cation;
- and
- (b) a dye absorbing at a second wavelength which is longer than said first wavelength, where irradiation of the medium at said second wavelength causes bleaching of the absorption of the compound (a) at the first wavelength, said imaging medium additionally comprising a thermally transferable colourant;
- (ii) assembling in contact with a receptor said first imaging element;
- (iii) exposing the assembly to a pattern of radiation at said second wavelength so as to cause thermal transfer of colourant to the receptor in irradiated areas and to bleach absorption of the compound (a) at said first wavelength;
- (iv) separating said first imaging element from the receptor and assembling said first imaging element in contact with a second imaging element which is sensitive to radiation of the first wavelength;
- and
- (v) exposing the assembly to a source of radiation of said first wavelength.
8 more elements
Dependencies are inferred from the claim text.