Photothermographic material

1. A photothermographic material comprising:

a substrate; and

an image forming layer disposed on one surface of the substrate, and containing at least a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for a silver ion, and a binder,

wherein, the photosensitive silver halide has a silver iodide content of 40 to 100 mol %, and an average particle size of 5 to 80 nm, and the photothermographic material contains a compound represented by formula (1);

Q-(Y) n —C(Z 1 )(Z 2 )X  formula (1)

wherein Q represents a heterocycle, Y represents a divalent connecting group, n represents 0 or 1, Z 1 and Z 2 each represent a halogen atom, and X represents a hydrogen atom or an electron withdrawing group;

and at least one compound represented by the following formula (T1);

wherein R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an aryl group, a halogen atom, an amino group, a nitro group, an alkoxycarbonyl group, a substituted or non-substituted carboxyl group or salt thereof, or a sulfonic group or salt thereof.

2. The photothermographic material according to claim 1 , wherein said photothermographic material contains a phthalic acid or a derivative thereof.

3. The photothermographic material according to claim 1 , wherein said photothermographic material contains a compound represented by the following formula (2):

wherein Z represents an atomic group for forming a 5-membered or 6-membered aromatic heterocycle; and R represents a hydrogen atom, an alkyl group, an aralkyl group, an alkoxy group, or an aryl group.

4. The photothermographic material according to claim 1 , wherein said photosensitive silver halide has an average particle size of 5 to 50 nm.

5. The photothermographic material according to claim 1 , wherein said photosensitive silver halide has a silver iodide content of 90 to 100 mol %.

6. The photothermographic material according to claim 1 , wherein said binder comprises polyvinyl butyral in an amount of 50 to 100 % by weight.

7. The photothermographic material according to claim 1 , wherein said photosensitive silver halide is spectrally sensitized to a wavelength range of 700 nm to 1400 nm by a spectral sensitizing dye.

8. The photothermographic material according to claim 7 , wherein said spectral sensitizing dye is at least one spectral sensitizing dye selected from the group represented by formulae (3a), (3b), (3c) and (3d):

wherein Y 1 , Y 2 and Y 11 each independently represent an oxygen atom, a sulfur atom, a selenium atom or a —CH═CH— group; L 1 to L 9 and L 11 to L 15 each independently represent a methine group; R 1 , R 2 , R 11 and R 12 each independently represent an aliphatic group; R 3 , R 4 , R 13 and R 14 each independently represent a lower alkyl group, a lower cycloalkyl group, a lower alkenyl group, a lower aralkyl group, a lower aryl group or a lower heterocyclic group; W 1 , W 2 , W 3 , W 4 , W 11 , W 12 , W 13 and W 14 each independently represent a hydrogen atom, a substituent, a non-metal atomic group necessary for bonding between W 1 and W 2 , W 3 and W 4 , W 11 and W 12 , W 13 and W 14 to form a condensed ring, or a non-metal atomic group necessary for bonding between R 3 and W 1 , R 3 and W 2 , R 13 and W 11 , R 13 and W 12 , R 4 and W 3 , R 4 and W 4 , R 14 and W 13 , and R 14 and W 14 to form a 5-membered or 6-membered ring; X 1 and X 11 each represent an ion necessary for neutralizing charge in the molecule, k 1 and k 11 each represent a number of ions necessary for neutralizing charge in the molecule; m 1 represents 0 or 1; n 1 , n 2 , n 11 and n 12 each represent 0, 1, or 2; and n 1 and n 2 do not simultaneously represent 0; and n 11 and n 12 do not simultaneously represent 0.

9. A photothermographic material comprising:

a substrate; and

an image forming layer disposed on one surface of the substrate, and containing at least a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for a silver ion, and a binder,

wherein, the photosensitive silver halide has a silver iodide content of 40 to 100 mol %, and an average particle size of 5 to 80 nm, and the photothermographic material contains a compound represented by formula (1);

Q-(Y) n —C(Z 1 )(Z 2 )X  formula (1)

wherein Q represents a heterocycle, Y represents a divalent connecting group, n represents 0 or 1, Z 1 and Z 2 each represent a halogen atom, and X represents a hydrogen atom or an electron withdrawing group;

and at least one compound represented by the following formula (T1);

wherein R represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an aryl group, a halogen atom, an amino group, a nitro group, an alkoxycarbonyl group, a substituted or non-substituted carboxyl group or salt thereof, or a sulfonic group or salt thereof;

and wherein methyl ethyl ketone is used as an application solvent, and a residual amount of the methyl ethyl ketone is 0.1 to 150 mg/m 2 .

10. The photothermographic material according to claim 1 , further comprising a compound represented by formula (PR):

wherein R 1 represents a hydroxyl group or a metal salt of a hydroxyl group; R 2 represents an alkyl group or an aryl group; and X represents an electron withdrawing group, or R 1 and X together form a ring containing an electron withdrawing group.

11. The photothermographic material according to claim 1 , further comprising at least one compound selected from the group consisting of compounds 1 to 5:

(1) a compound that can be one-electron-oxidized to provide a one-electron oxidation product which further releases at least two electrons, due to when subjected to a subsequent bond cleavage reaction;

(2) a compound that has at least 2 groups adsorbable to the silver halide and can be one-electron-oxidized to provide a one-electron oxidation product which further releases one electron, due to when subjected to a subsequent bond cleavage reaction;

(3) a compound that can be one-electron-oxidized to provide a one-electron oxidation product, which further releases at least one electron after being subjected to a subsequent bond formation;

(4) a compound that can be one-electron-oxidized to provide a one-electron oxidation product which further releases at least one electron after a subsequent ring cleavage reaction in the molecule; and

(5) a compound represented by X—Y, in which X represents a reducing group and Y represents a leaving group, and convertable by one-electron-oxidizing the reducing group to a one-electron oxidation product which can be converted into an X radical by eliminating the leaving group in a subsequent X—Y bond cleavage reaction, one electron being released from the X radical.