Photothermographic material and image forming method
View Patent ↗A photothermographic material including, on at least one surface of a support, at least a photosensitive silver halide containing a silver iodide at 40 mol % or more, a non-photosensitive organic silver salt, and a reducing agent, wherein the photothermographic material contains two or more kinds of the reducing agent at the mixing ratio to satisfy at least one of a), b), c) and d): a) a difference between a sensitivity or b) a difference between a maximum density is 0.10 or less, when developed at 120° C. for 10 sec and a sensitivity when developed at 120° C. for 14 sec; c) a difference between a sensitivity or d) a difference between a maximum density is 0.10 or less, when developed at 117° C. for 12 sec and a sensitivity when developed at 123° C. for 12 sec. An image forming method using the photothermographic material is also provided.
1. A photothermographic material comprising, on at least one surface of a support, at least a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent and a binder, wherein the photosensitive silver halide has a silver iodide content of 40 mol % or more, and the photothermographic material contains two or more kinds of the reducing agent at the mixing ratio to satisfy at least one of a) and b):
a) a difference between a sensitivity when the photothermographic material has been imagewise exposed using a laser beam source and developed at 120° C. for 10 sec and a sensitivity when the photothermographic material has been imagewise exposed using a laser beam source and developed at 120° C. for 14 sec is 0.10 or less, wherein these sensitivities are expressed as a logarithm of a reciprocal of an exposure value;
b) a difference between a maximum density when the photothermographic material has been imagewise exposed using a laser beam source and developed at 120° C. for 10 sec and a maximum density when the photothermographic material has been imagewise exposed using a laser beam source and developed at 120° C. for 14 sec is 0.10 or less.
2. A photothermographic material comprising, on at least one surface of a support, at least a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent and a binder, wherein the photosensitive silver halide has a silver iodide content of 40 mol % or more, and the photothermographic material contains two or more kinds of the reducing agent at the mixing ratio to satisfy at least one of a) and b):
a) a difference between a sensitivity when the photothermographic material has been imagewise exposed using a laser beam source and developed at 117° C. for 12 sec and a sensitivity when the photothermographic material has been imagewise exposed using a laser beam source and developed at 123° C. for 12 sec is 0.10 or less, wherein these sensitivities are expressed as a logarithm of a reciprocal of an exposure value;
b) a difference between a maximum density when the photothermographic material has been imagewise exposed using a laser beam source and developed at 117° C. for 12 sec and a maximum density when the photothermographic material has been imagewise exposed using a laser beam source and developed at 123° C. for 12 sec is 0.10 or less.
3. The photothermographic material according to claim 1 further containing a development accelerator at an optimum coating amount thereof to satisfy at least one of the a) and b).
4. The photothermographic material according to claim 2 further containing a development accelerator at an optimum coating amount thereof to satisfy at least the one of the a) and b).
5. The photothermographic material according to claim 1 , wherein the laser beam source has a wavelength of 350 nm to 450 nm.
6. The photothermographic material according to claim 2 , wherein the laser beam source has a wavelength of 350 nm to 450 nm.
7. The photothermographic material according to claim 1 , wherein one of the two or more kinds of the reducing agent contains a compound represented by formula (R):
wherein L is —CH 2 — group. R 11 and R 11′ each represent a t-butyl group. X 1 , and X 1 ′ are hydrogen atom. R 12 and R 12′ each represent an ethyl group.
8. The photothermographic material according to claim 1 , wherein one of the two or more kinds of the reducing agent contains a compound represented by formula (R):
wherein L is —CH(R 13 )— group, wherein R 13 is a primary or secondary alkyl group having 1 to 8 carbon atoms. R 11 and R 11′ each independently represent a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. R 12 and R 12′ each represent a methyl group. X 1 , and X 1 ′ are hydrogen atom.
9. The photothermographic material according to claim 8 , wherein R 13 in —CH(R 13 )— is a secondary alkyl group, and R 11 and R 11′ each represent a methyl group.
10. The photothermographic material according to claim 2 , wherein one of the two or more kinds of the reducing agent contains a compound represented by formula (R):
wherein L is —CH 2 — group. R 11 and R 11′ each represent a t-butyl group. X 1 , and X 1 ′ each represent a hydrogen atom. R 12 and R 12′ each represent an ethyl group.
11. The photothermographic material according to claim 2 , wherein one of the two or more kinds of the reducing agent contains a compound represented by formula (R):
wherein L is —CH(R 13 )— group, wherein R 13 is a primary or secondary alkyl group having 1 to 8 carbon atom. R 11 and R 11′ each independently represent a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. R 12 and R 12′ each represent a methyl group. X 1 and X 1 ′ each represent a hydrogen atom.
12. The photothermographic material according to claim 11 , wherein R 13 in —CH(R 13 )— is a secondary alkyl group, and R 11 and R 11′ each represent a methyl group.
13. The photothermographic material according to claim 1 further containing a polyhalogen compound at an optimum coating amount thereof to satisfy at least one of a) and b).
14. The photothermographic material according to claim 2 further containing a polyhalogen compound at an optimum coating amount thereof to satisfy at least one of a) and b).
15. A method of forming an image, wherein the photothermographic material according to claim 1 is imagewise exposed using a laser beam source and developed at a temperature selected from a range of 100° C. to 140° C. for 12 sec or less, wherein the imagewise exposure is started from a leading end of the photothermographic material followed by the thermal development which is started before completing the imagewise exposure up to a posterior end thereof.
16. The method of forming an image according to claim 15 , wherein the photothermographic material is developed at a line speed of 23 mm/sec or higher.
17. A method of forming an image, wherein the photothermographic material according to claim 2 is imagewise exposed using a laser beam source and developed at a temperature selected from a range of 100° C. to 140° C. for 12 sec or less, wherein the imagewise exposure is started from a leading end of the photothermographic material followed by the thermal development which is started before completing the imagewise exposure up to a posterior end thereof.
18. The method of forming an image according to claim 17 , wherein the photothermographic material is developed at a line speed of 23 mm/sec or higher.