Imaging particulates, paper and process, and imaging of paper using dual wavelength light
The present invention provides dual wavelength imaging compositions, processes for forming dual wavelength imaging compositions, methods for forming images using dual wavelength imaging compositions and substrate (e.g., paper web) treated (e.g., coated) on one or both sides with dual wavelength imaging compositions. Also provided is a dual wavelength imaging particulate comprising a matrix of polymer material and containing: one or more image-forming agents; a photo-oxidizing agent which is activated at a first wavelength of light to cause the one or more image-forming agents to form one or more images; and a reducing agent which is activated at a second wavelength of light to cause termination of the formation of the one or more images.
1. An article comprising: a dual wavelength image-forming particulate comprising a polymeric matrix of polymer material in which is contained: one or more image-forming agents comprising a light activated dye; a photo-oxidizing agent which is activated at a first wavelength of light to cause the one or more image-forming agents to form one or more images; and a reducing agent which is activated at a second wavelength of light to cause termination of the formation of the one or more images.
2. The article of claim 1 , wherein the polymer material comprises cellulose acetate butyrate.
3. The article of claim 1 , wherein the one or more imaging agents comprise a leuco dye.
4. The article of claim 1 , wherein the polymeric matrix of each particulate further comprises a plasticizer.
5. The article of claim 1 , wherein the photo-oxidizing agent is activated at a wavelength in the range of from about 300 to about 350 nm, and wherein the reducing agent is activated at a wavelength in the range of from about 360 to about 450 nm.
6. The article of claim 1 , wherein at least some of the particulates are about 10 microns or less in diameter.
7. The article of claim 6 , wherein at least some of the particulates are about 5 microns or less in diameter.
8. An imaging composition comprising:
a solvent; and
a plurality of dual wavelength image-forming particulates dispersed in the solvent, wherein each particulate of the plurality of particulates comprises a polymeric matrix of polymer material in which is contained:
one or more imaging agents comprising a light activated dve; and
a photo-oxidizing agent which is activated at a first wavelength of light to cause the one or more image-forming agents to form one or more images; and
a reducing agent which is activated at a second wavelength of light to cause termination of the formation of the one or more images.
9. The imaging composition of claim 8 , wherein the solvent comprises water.
10. The imaging composition of claim 8 , wherein the polymer material comprises cellulose acetate butyrate.
11. The imaging composition of claim 8 , wherein the polymer material comprises from about 40 to about 99% of the solids portion of the imaging composition.
12. The imaging composition of claim 11 , wherein the polymer material comprises from about 50 to about 80% of the solids portion of the imaging composition.
13. The imaging composition of claim 8 , wherein the polymeric matrix of each particulate further comprises a plasticizer and wherein the plasticizer comprises up to about 45% of the solids portion of the imaging composition.
14. The imaging composition of claim 13 , wherein the plasticizer comprises from about 10 to about 20% of the solids portion of the imaging composition.
15. The imaging composition of claim 8 , wherein the one or more imaging agents comprise a leuco dye comprising from about 0.1 to about 10% of the solids portion of the imaging composition.
16. The imaging composition of claim 15 , wherein the leuco dye comprises from about 1 to about 3% of the solids portion of the imaging composition.
17. The imaging composition of claim 8 , wherein the polymeric matrix of each particulate further contains one or more acids/couplers and wherein the acids/couplers collectively comprise from about 0.1 to about 20% of the solids portion of the imaging composition.
18. The imaging composition of claim 17 , wherein the acids/couplers collectively comprise from about 1 to about 6% of the solids portion of the imaging composition.
19. The imaging composition of claim 8 , wherein the photo-oxidizing agent is activated at a wavelength in the range of from about 300 to about 350 nm, and wherein the reducing agent is activated at a wavelength in the range of from about 360 to about 450 nm.
20. The imaging composition of claim 8 , wherein the particulates are about 10 microns or less in diameter.
21. The imaging composition of claim 20 , wherein at least some of the particulates are about 5 microns or less in diameter.
22. An article comprising:
a substrate having first and second surfaces; and
a plurality image-forming particulates applied to at least one of the first and second surfaces, each particulate comprising a polymeric matrix of polymer material and in which is contained:
one or more imaging agents comprising a light activated dye;
a photo-oxidizing agent which is activated at a first wavelength of light to cause the one or more image-forming agents to form one or more images in or on the substrate; and
a reducing agent which is activated at a second wavelength of light to cause termination of the formation of the one or more images.
23. The article of claim 22 , wherein the polymer material comprises cellulose acetate butyrate.
24. The article of claim 22 , wherein the polymer material comprises from about 40 to about 99% of the solids portion of the imaging composition.
25. The article of claim 24 , wherein the polymer material comprises from about 50 to about 80% of the solids portion of the imaging composition.
26. The article of claim 22 , wherein the polymeric matrix of each particulate further comprises a plasticizer and wherein the plasticizer comprises up to about 45% of the solids portion of the imaging composition.
27. The article of claim 26 , wherein the plasticizer comprises from about 10 to about 20% of the solids portion of the imaging composition.
28. The article of claim 22 , wherein the one or more imaging agents comprise a leuco dye comprising from about 0.1 to about 10% of the solids portion of the imaging composition.
29. The article of claim 28 , wherein the leuco dye comprises from about 1 to about 3% of the solids portion of the imaging composition.
30. The article of claim 22 , wherein the polymeric matrix of each particulate further contains one or more acids/couplers and wherein the acids/couplers collectively comprise from about 0.1 to about 20% of the solids portion of the imaging composition.
31. The article of claim 30 , wherein the acids/coupler collectively comprise from about 1 to about 6% of the solids portion of the imaging composition.
32. The article of claim 22 , wherein the photo-oxidizing agent is activated at a wavelength in the range of from about 300 to about 450 nm.
33. The article of claim 22 , wherein the photo-oxidizing agent is activated at a wavelength in the range of from about 300 to about 350 nm, and wherein the reducing agent is activated at a wavelength in the range of from about 360 to about 450 nm.
34. The article of claim 22 , wherein at least some of the particulates are about 10 microns or less in diameter.
35. The article of claim 34 , wherein at least some of the particulates are about 5 microns or less in diameter.
36. The method comprising the following steps:
(a) providing a dual wavelength imaging substrate comprising:
a plurality of dual wavelength image-forming, particulates applied to at least one of the first and second surfaces, wherein the particulates each comprise a polymeric matrix of polymer material in which is contained:
one or more imaging agents comprising a light activated dye;
a photo-oxidizing agent which is activated at a first wavelength of light to cause the one or more image-forming agents to form one or more images; and
a reducing agent which is activated at a second wavelength of light to cause termination of the formation of the one or more images;
(b) subjecting the dual wavelength imaging substrate of step (a) to the first wave length of light that activates the photo-oxidizing agent to cause the one or more imaging agents to form one or more images in or on the substrate; and
(c) subjecting the imaged substrate of step (b) to the second wave length of light that activates the reducing agent to cause the termination of the formation of the one or more images.
37. The method of claim 36 , wherein the polymer material of each particulate of step (a) comprises cellulose acetate butyrate.
38. The method of claim 36 , wherein the one or more imaging agents of step (a) comprise a leuco dye.
39. The method of claim 36 , wherein the photo-oxidizing agent of step (a) is activated during step (b) at a wavelength in the range of from about 300 to about 350 nm, and wherein the reducing agent of step (a) is activated during step (c) at a wavelength in the range of from about 360 to about 450 nm.
40. The article of claim 22 , wherein the substrate comprises a paper web.
41. The method of claim 36 , wherein the dual wavelength imaging substrate of step (a) comprises a paper web.