JP2002040591A - Heat developable photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable photosensitive material having high sensitivity and a little fog, capable of giving a high density and excellent in preservability. SOLUTION: The heat developable photosensitive material contains at least one photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one face of the base, and further contains at least one compound of formula (I) (where dye1 is a dye: M1 is a counter ion equilibrated with an electric charge; m1 is a number required to neutralize electric charges in each molecule; (q) is an integer of >=1; and R1 is one of R1a to R1d of formulae (a) to (d) (where Ra to Rd are each an alkyl, aryl, a heterocyclic group, alkoxy, aryloxy, heterocyclic oxy or amino; Qa to Qd are each a linking group; and (r) to (u) are each 0 or 1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material.

[0002]

2. Description of the Related Art In recent years, in the field of medical diagnostic films and photoengraving films, it has been strongly desired to reduce the amount of processing waste liquid from the viewpoint of environmental protection and space saving. Therefore, heat development can be performed by a laser imagesetter or a laser imager to form a clear black image having high resolution and sharpness. There is a need for techniques relating to photosensitive materials. According to these photothermographic materials, a photothermographic processing system that does not require solution-based processing chemicals, is simpler, and does not damage the environment can be supplied to customers.

[0003] In the field of general image forming materials, there are similar requirements, but in particular, medical diagnostic images require fine depiction, so that high quality images with excellent sharpness and granularity are required. There is a feature that a cool black image is preferred from the viewpoint of easiness. At present, various hard copy systems using pigments and dyes, such as ink jet printers and electrophotographs, are distributed as general image forming systems, but there is no satisfactory system for outputting medical images.

On the other hand, thermal image forming systems using an organic silver salt are disclosed in, for example, US Pat. Crosta Bohr (Kl
osterboer) "Heat Processed Silver System (Ther
mally Processed Silver Systems) "(Imaging
Processings and Materials (Imaging Proce
sses and Materials) Neblette Eighth Edition, J. Sturge (Stu
rge), V. Walworth, A. Shep
p) Compilation, Chapter 9, p. 279, 1989). In particular, the photothermographic material generally contains a catalytically active amount of a photocatalyst (for example, silver halide), a reducing agent, a reducible silver salt (for example, an organic silver salt), and if necessary, a color toning agent for controlling the color tone of silver. And a photosensitive layer dispersed in a binder matrix. After the image exposure, the photothermographic material is heated to a high temperature (for example, 80 ° C. or higher) to form a black silver image by an oxidation-reduction reaction between a reducible silver salt (which functions as an oxidizing agent) and a reducing agent. Form. The oxidation-reduction reaction is promoted by the catalytic action of the latent image of silver halide generated by exposure. Therefore, a black silver image is formed in the exposed area. U.S. Patent No. 2910377, Japanese Patent Publication No. 43-4924
And many other documents.

[0005] Further, conventionally, a large number of spectral sensitizing dyes of silver halide used in these photothermographic materials have been used, and great efforts have been made to increase sensitivity and storage stability. It has been done. However, for example, JP-A-2000-98525 and JP-A-2000-1222
No sensitizing dyes described in JP-A-06-2006 and the like exhibit satisfactory performance, and there is still a need for improvement. Further, it is required that the output image density is stably output due to the fluctuation due to the environment such as humidity and temperature in which the system is placed.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art.
That is, an object of the present invention is to provide a photothermographic material having high sensitivity, low fog, and excellent storage stability capable of giving a high density. Further, the present invention provides
Another object of the present invention is to provide a photothermographic material that provides a stable output density against environmental fluctuations such as humidity and temperature in which the system is placed.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, by using a sensitizing dye represented by the general formula (I) defined in the present specification. It has been found that an excellent photothermographic material exhibiting desired effects can be provided, and the present invention has been completed.

That is, according to the present invention, a photothermographic method comprising at least one photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one surface of a support. A photothermographic material comprising at least one compound represented by the following general formula (I) is provided.

Embedded image (Wherein, dye ¹ represents a dye; M ¹ represents a charge-balancing counter ion; m ¹ represents a number required to neutralize the charge of a molecule; q represents an integer of 1 or more; R ¹ Is R represented by
^1a , R ^1b , R ^1c or R ^1d .

Embedded image ^{Wherein, R a, R b, R} c, and R ^d each independently represent an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, heterocyclyloxy group, or an amino group, Q ^a, Q ^b , Q ^c and Q ^d represent a linking group. r, s,
t and u are 0 or 1. )

Preferably, the compound of the general formula (I)
Q^aAnd R^aAt least one of the Q^bAnd R^bof
At least one of them, Q^cAnd R^cAt least one of
One, Q ^dAnd R^dAt least one of which contains an aromatic ring
It is a group.

Preferably, in the compound of the general formula (I), R ^a , R ^b , R ^c and R ^d are represented by the following formula.

Embedded image (In the formula, La represents ^a linking group. H is 0 or 1. A ¹
Represents an aromatic group. )

Preferably, dye ¹ is selected from the following formulas (X), (XI) and (XII).

Embedded image(In the formula (X), L¹¹, L¹², L¹³, L¹⁴, L^Fifteen,
L¹⁶, And L¹⁷Each independently represents a methine group. p¹¹as well as
p¹²Each independently represents 0 or 1. n¹¹Is 0, 1,
Represents 2, 3 or 4. Z¹¹And Z¹²Are independently nitrogen-containing
A group of atoms necessary to form an elementary heterocyclic ring.
The ring may be fused. M¹Represents a charge-balancing counterion
Represents, m¹Represents the number required to neutralize the molecular charge.
You. R¹¹And R¹²Are each independently an alkyl group, an aryl
Represents a group or a heterocyclic group. Where L¹¹, L¹², L¹³, L
¹⁴, L^Fifteen, L¹⁶, L¹⁷, Z¹¹, Z¹², R¹¹And R ¹²To
Is at least one R¹The group represented by
You. )

Embedded image (In formula (XI), L ¹⁸ , L ¹⁹ , L ²⁰ , and L ²¹ each independently represent a methine group. P ¹³ represents 0 or 1. q ¹¹ represents 0 or 1. n ¹² represents 0. , together with .Z ¹³ .Z ¹⁴ and Z ¹⁴ 'each independently (N-R ¹⁴⁾ q ¹¹ representing the atomic group necessary to form a nitrogen-containing heterocyclic ring which represents 1, 2, 3 or 4 Represents a group of atoms necessary to form a heterocyclic or acyclic acidic terminal group, provided that Z ¹³ and Z
Rings may be fused to ¹⁴ and Z ¹⁴ ′. M ¹ represents a charge balancing counter ion, and m ¹ represents a number necessary to neutralize the charge of the molecule. R ¹³ represents an alkyl group, an aryl group, or a heterocyclic group. R ¹⁴ represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group. However, L ¹⁸ , L ¹⁹ , L ²⁰ ,
L ²¹ , Z ¹³ , Z ¹⁴ , Z ¹⁴ ′, R ¹³ and R ¹⁴ are substituted with at least one group represented by R ¹ . )

Embedded image(In the formula (XII), L^{twenty two}, L^{twenty three}, L^{twenty four}, L^{twenty five}, L²⁶,
L²⁷, L²⁸, L²⁹, And L³⁰Each independently represent a methine group
You. p¹⁴And p^FifteenEach independently represents 0 or 1. q¹²Is
Represents 0 or 1. n¹³And n¹⁴Are independently 0, 1,
Represents 2, 3 or 4. Z^FifteenAnd Z¹⁷Are independently nitrogen-containing
Represents an atom group necessary for forming a heterocyclic ring. Z¹⁶When
Z¹⁶′ Are each independently (N—R¹⁶) Q¹²Together with
Represents the group of atoms necessary to form a ring. However,
Z^Fifteen, Z¹⁶And Z¹⁶’And Z¹⁷May be fused
No. M¹Represents a charge-balancing counter ion, m¹Is the charge of the molecule
Indicates the number required for neutralization. R^Fifteen, And R¹⁷Is German
Stands for an alkyl group, an aryl group, or a heterocyclic group.
R¹⁶Is a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic ring
Represents a group. Where L^{twenty two}, L^{twenty three}, L^{twenty four}, L^{twenty five}, L²⁶, L
²⁷, L²⁸, L²⁹, L³⁰, Z^Fifteen, Z ¹⁶, Z¹⁶’, Z¹⁷,
R^Fifteen, R¹⁶Or R¹⁷Has at least one R¹In table
Group is substituted. )

Preferably, the average equivalent circle diameter of the photosensitive silver halide is 10 to 50 nm.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method and an embodiment of the present invention will be described in detail. In addition, in this specification, "-" is used in the meaning including the value described before and after it as a lower limit and an upper limit. First, the compound of the general formula (I) used in the present invention will be described. As the dye represented by dye ¹ in the general formula (I), any dye may be used. Complex cyanine dye, complex merocyanine dye, allopolar dye, oxonol dye,
Hemioxonol dye, squarium dye, croconium dye, azamethine dye, coumarin dye, arylidene dye, anthraquinone dye, triphenylmethane dye,
Azo dye, azomethine dye, spiro compound, metallocene dye, fluorenone dye, fulgide dye, perylene dye, phenazine dye, phenothiazine dye, quinone dye, indigo dye, diphenylmethane dye, polyene dye, acridine dye, acridinone dye, diphenylamine dye, quinacridone dye Quinophthalone dye, phenoxazine dye, phthaloperylene dye, porphyrin dye, chlorophyll dye, phthalocyanine dye, and metal complex dye.

The dye represented by dye ¹ is preferably a cyanine dye, a styryl dye, a hemicyanine dye,
Polymethine chromophores such as merocyanine dyes, trinuclear merocyanine dyes, tetranuclear merocyanine dyes, rhodocyanine dyes, complex cyanine dyes, complex merocyanine dyes, allopolar dyes, oxonol dyes, hemioxonol dyes, squarium dyes, croconium dyes, and azamethine dyes. More preferably, cyanine dyes, merocyanine dyes, and trinuclear merocyanine dyes (the basic skeleton of trinuclear merocyanine is described in
General formulas (I) and (II) of JP-A-71135, JP-A-7-17-1
The basic skeleton represented by the general formula (I) described in JP-A-59920 is preferred.) A tetranuclear merocyanine dye (as a basic skeleton of a tetranuclear merocyanine, European Patent No. 735,41)
No. 5, the basic skeleton represented by the general formula (I) is preferred), rhodacyanine dyes, particularly preferably merocyanine dyes and rhodacyanine dyes, and most preferably merocyanine dyes. The dye represented by dye ¹ is more preferably a sensitizing dye that spectrally sensitizes a silver halide photographic emulsion.

For details of these dyes, see “Heterocyclic Compounds—Cyanine Soybeans and Related Products” by FM Harmer.
Compounds (Heterocyclic Compounds-Cyanine Dyes a
nd Related Compounds), John Wiley & Sons, New York, London, 1964, DM Sturmer (DMStu
rmer), Heterocyclic Compounds-Special topics in heterocyclic chemistry
terocyclic chemistry) ", Chapter 18, Section 14, Section 4
It is described on pages 82 to 515 and the like. Preferred general formulas of the dyes include the general formulas described in U.S. Pat. No. 5,994,051 at pages 32 to 36 and the general formulas described in U.S. Pat. No. 5,747,236 at pages 30 to 34. A general formula is given. The general formulas of preferred cyanine dyes, merocyanine dyes and rhodacyanine dyes are described in U.S. Pat. No. 5,340,694, column 21-22, (X
(I), (XII) and (XIII) (however, the number of n12, n15, n17 and n18 is not limited, and may be an integer of 0 or more (preferably 4 or less)).

The dye represented by dye ¹ is more preferably a dye represented by the following formula (X), (XI) or (XII), and particularly preferably a dye represented by the following formula (XI).

[0017]

Embedded image

In the formula (X), L¹¹, L¹², L¹³, L¹⁴,
L^Fifteen, L¹⁶, And L¹⁷Each independently represents a methine group. p
¹¹And p¹²Each independently represents 0 or 1. n¹¹Is 0,
Represents 1, 2, 3 or 4. Z¹¹And Z¹²Are each independently
Represents a group of atoms necessary to form a nitrogen-containing heterocyclic ring.
The rings may be fused. M¹Is the charge balance versus Io
And m¹Is the number needed to neutralize the molecular charge
Represent. R¹¹And R¹²Are each independently an alkyl group, an aryl
Represents a group or a heterocyclic group. Where L¹¹, L¹², L¹³, L
¹⁴, L^Fifteen, L¹⁶, L¹⁷, Z¹¹, Z¹², R¹¹And R ¹²To
Is at least one R₁The group represented by
You.

[0019] Preferably, the case where the group represented by R ¹ to R ¹¹ or R ¹² is substituted, more preferably R ¹¹
And R ¹² are both substituted by the group represented by R ¹ .

[0020]

Embedded image

In the formula (XI), L ¹⁸ , L ¹⁹ , L ²⁰ and L ²¹ each independently represent a methine group. p ¹³ represents 0 or 1. q ¹¹ represents 0 or 1. n ¹² represents 0, 1, 2, 3, or 4. Z ¹³ represents an atom group necessary for forming a nitrogen-containing heterocyclic ring. Z ¹⁴ and Z ¹⁴ ′ are each independently (N−
It represents a R ¹⁴⁾ heterocyclic ring together with q ^11, or acyclic atomic group necessary for forming an acidic end groups. However,
A ring may be condensed on Z ¹³ and Z ¹⁴ and Z ¹⁴ ′. M
¹ represents a charge-balancing counter ion, and m ¹ represents the number required to neutralize the charge of the molecule. R ¹³ represents an alkyl group, an aryl group, or a heterocyclic group. R ¹⁴ represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group. However, L ¹⁸ ,
L ¹⁹ , L ²⁰ , L ²¹ , Z ¹³ , Z ¹⁴ , Z ¹⁴ ′, R ¹³ and R ¹⁴
Is substituted by at least one group represented by R ¹ .

Preferably, R ¹³ or R ¹⁴ is substituted with a group represented by R ¹ . More preferably, R
^This is the case where ¹³ is substituted with the group represented by R ¹ .

[0023]

Embedded image

In the formula (XII), L^{twenty two}, L^{twenty three}, L^{twenty four}, L
^{twenty five}, L²⁶, L²⁷, L²⁸, L²⁹, And L³⁰Are independent
Represents a tin group. p¹⁴And p^FifteenRepresents 0 or 1 each independently.
You. q¹²Represents 0 or 1. n¹³And n¹⁴Are independent
Represents 0, 1, 2, 3 or 4. Z^FifteenAnd Z¹⁷Is German
Lists the atoms required to form a nitrogen-containing heterocyclic ring.
You. Z¹⁶And Z¹⁶′ Are each independently (N—R¹⁶) Q¹²And one
List of atoms necessary to form a heterocyclic ring
You. Where Z^Fifteen, Z¹⁶And Z¹⁶’And Z¹⁷Ring is condensed
It may be ringed. M¹Represents a charge-balancing counter ion, m¹
Represents the number required to neutralize the molecular charge. R^Fifteen,
And R¹⁷Are each independently an alkyl group, an aryl group,
Represents a ring group. R¹⁶Is hydrogen atom, alkyl group, aryl
Represents a group or a heterocyclic group. Where L^{twenty two}, L^{twenty three}, L^{twenty four},
L^{twenty five}, L²⁶, L²⁷, L²⁸, L²⁹, L³⁰, Z^Fifteen, Z ¹⁶,
Z¹⁶’, Z¹⁷, R^Fifteen, R¹⁶Or R¹⁷At least
One R¹Is substituted.

Preferably, R ¹⁵ , R ¹⁶ or R ¹⁷ is R ¹
Is the case where the group represented by is substituted, and more preferably, the group represented by R ¹ is substituted on R ¹⁵ or R ¹⁷ .

Next, the groups used in the present invention will be described in more detail. In the present invention, when a particular moiety is referred to as a "group", the moiety may be unsubstituted or substituted with one or more (up to the maximum number of possible) substituents. Means good. For example, “alkyl group” means a substituted or unsubstituted alkyl group. The substituents that can be used in the compounds of the present invention include any substituents, regardless of whether they are substituted or not.

Assuming that such a substituent is V, the substituent represented by V is not particularly limited, and examples thereof include a halogen atom, an alkyl group [(a cycloalkyl group and a bicycloalkyl group. Alkenyl groups (including cycloalkenyl groups and bicycloalkenyl groups) and alkynyl groups. ], An aryl group, a heterocyclic group (also referred to as a heterocyclic group), a cyano group, a hydroxyl group, a nitro group, a carboxyl group,
Alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy, amino group (including anilino group), ammonium group, acylamino group, aminocarbonylamino Group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl and arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl and arylsulfinyl Groups, alkyl and arylsulfonyl groups, acyl groups, aryloxycarbonyl groups, alkoxycarbonyl groups, carbamoyl groups, aryl and heterocyclic azo groups,
Examples include an imide group, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group, a phospho group, a silyl group, a hydrazino group, a ureido group, and other known substituents.

More specifically, the substituent V is a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an alkyl group [a linear, branched, or cyclic substituted or unsubstituted alkyl group. . They include alkyl groups (preferably alkyl groups having 1 to 30 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, t-butyl, n-octyl, eicosyl, 2-chloroethyl,
-Cyanoethyl, 2-ethylhexyl), a cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, for example, cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl), a bicycloalkyl group (preferably And a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms.
2] heptane-2-yl, bicyclo [2,2,2] octan-3-yl), and a tricyclo structure having many ring structures. An alkyl group (for example, an alkyl group of an alkylthio group) in the substituents described below represents an alkyl group having such a concept, and further includes an alkenyl group and an alkynyl group. And an alkenyl group [which represents a linear, branched or cyclic substituted or unsubstituted alkenyl group. They include alkenyl groups (preferably substituted or unsubstituted alkenyl groups having 2 to 30 carbon atoms, for example, vinyl, allyl, prenyl, geranyl, oleyl), cycloalkenyl groups (preferably substituted or substituted with 3 to 30 carbon atoms). An unsubstituted cycloalkenyl group, that is, a monovalent group obtained by removing one hydrogen atom from a cycloalkene having 3 to 30 carbon atoms, for example, 2-cyclopenten-1-yl, 2-cyclohexen-1-yl), Bicycloalkenyl group (substituted or unsubstituted bicycloalkenyl group, preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent obtained by removing one hydrogen atom of a bicycloalkene having one double bond) For example, bicyclo [2,2,1] hept-2-en-1-yl, bicyclo 2,2,2] oct-2-en-4-yl). ],
Alkynyl group (preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, for example, ethynyl, propargyl, trimethylsilylethynyl group)], an aryl group (preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms) For example, phenyl, p-tolyl, naphthyl,
m-chlorophenyl, o-hexadecanoylaminophenyl), a heterocyclic group (preferably a 5- or 6-membered substituted or unsubstituted aromatic or non-aromatic heterocyclic compound, obtained by removing one hydrogen atom from a monovalent compound) And more preferably a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms, for example, 2-furyl, 2-thienyl, 2-pyrimidinyl, 2-benzothiazolyl, and
A cationic heterocyclic group such as 1-methyl-2-pyridinio and 1-methyl-2-quinolinio may be used. ), A cyano group, a hydroxyl group, a nitro group, a carboxyl group, an alkoxy group (preferably a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, for example, methoxy, ethoxy, isopropoxy, t-butoxy, n-octyl) Oxy, 2-methoxyethoxy), aryloxy group (preferably substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, for example, phenoxy, 2-methylphenoxy, 4-t-butylphenoxy, 3-nitrophenoxy) , 2-tetradecanoylaminophenoxy), a silyloxy group (preferably a silyloxy group having 3 to 20 carbon atoms, for example, trimethylsilyloxy, t-butyldimethylsilyloxy), a heterocyclic oxy group (preferably having 2 to 2 carbon atoms) 30 substituted or unsubstituted heterocyclic oxy groups, - phenyl tetrazole over 5-oxy, 2
-Tetrahydropyranyloxy), an acyloxy group (preferably a formyloxy group, a substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, a carbon number of 6)
To 30 substituted or unsubstituted arylcarbonyloxy groups, for example, formyloxy, acetyloxy, pivaloyloxy, stearoyloxy, benzoyloxy, p-methoxyphenylcarbonyloxy), carbamoyloxy group (preferably having 1 to 30 carbon atoms) A substituted or unsubstituted carbamoyloxy group, for example, N,
N-dimethylcarbamoyloxy, N, N-diethylcarbamoyloxy, morpholinocarbonyloxy,
N-di-n-octylaminocarbonyloxy, Nn
-Octylcarbamoyloxy), an alkoxycarbonyloxy group (preferably a substituted or unsubstituted alkoxycarbonyloxy group having 2 to 30 carbon atoms, for example, methoxycarbonyloxy, ethoxycarbonyloxy, t
-Butoxycarbonyloxy, n-octylcarbonyloxy), an aryloxycarbonyloxy group (preferably a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms, for example, phenoxycarbonyloxy, p-methoxyphenoxycarbonyloxy , Pn-hexadecyloxyphenoxycarbonyloxy), an amino group (preferably an amino group, having 1 carbon atom)
To 30 substituted or unsubstituted alkylamino groups, substituted or unsubstituted anilino groups having 6 to 30 carbon atoms, such as amino, methylamino, dimethylamino, anilino, N-methyl-anilino, diphenylamino), and ammonio group (Preferably an ammonio group, a substituted or unsubstituted alkyl or aryl having 1 to 30 carbon atoms, an ammonio group substituted with a heterocyclic ring, for example, trimethylammonio, triethylammonio, diphenylmethylammonio), an acylamino group (preferably A formylamino group, a substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted arylcarbonylamino group having 6 to 30 carbon atoms, for example, formylamino, acetylamino, pivaloylamino, lauroylamino, Benzoi Amino, 3,4,5-tri -n
-Octyloxyphenylcarbonylamino), aminocarbonylamino group (preferably substituted or unsubstituted aminocarbonylamino having 1 to 30 carbon atoms, for example, carbamoylamino, N, N-dimethylaminocarbonylamino, N, N-diethylamino Carbonylamino, morpholinocarbonylamino), alkoxycarbonylamino group (preferably substituted or unsubstituted alkoxycarbonylamino group having 2 to 30 carbon atoms, for example, methoxycarbonylamino, ethoxycarbonylamino,
t-butoxycarbonylamino, n-octadecyloxycarbonylamino, N-methyl-methoxycarbonylamino), an aryloxycarbonylamino group (preferably a substituted or unsubstituted aryloxycarbonylamino group having 7 to 30 carbon atoms, for example, Phenoxycarbonylamino, p-chlorophenoxycarbonylamino,
mn-octyloxyphenoxycarbonylamino),
Sulfamoylamino group (preferably having 0 to 3 carbon atoms)
0 substituted or unsubstituted sulfamoylamino groups, for example, sulfamoylamino, N, N-dimethylaminosulfonylamino, Nn-octylaminosulfonylamino), alkyl and arylsulfonylamino groups (preferably having Substituted or unsubstituted alkylsulfonylamino having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfonylamino having 6 to 30 carbon atoms, for example, methylsulfonylamino, butylsulfonylamino, phenylsulfonylamino, 2,3,5-trichlorophenyl Sulfonylamino, p-methylphenylsulfonylamino), mercapto group, alkylthio group (preferably,
A substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms, for example, methylthio, ethylthio, n-hexadecylthio), an arylthio group (preferably having 6 to 30 carbon atoms)
A substituted or unsubstituted arylthio such as phenylthio, p-chlorophenylthio, m-methoxyphenylthio), a heterocyclic thio group (preferably having 2 to 3 carbon atoms)
0 substituted or unsubstituted heterocyclic thio group, for example, 2-
Benzothiazolylthio, 1-phenyltetrazole-5
-Ylthio), a sulfamoyl group (preferably having 0 carbon atoms)
To 30 substituted or unsubstituted sulfamoyl groups, for example, N-ethylsulfamoyl, N- (3-dodecyloxypropyl) sulfamoyl, N, N-dimethylsulfamoyl, N-acetylsulfamoyl, N-benzoyl Sulfamoyl, N- (N'-phenylcarbamoyl) sulfamoyl), sulfo group, alkyl and arylsulfinyl group (preferably substituted or unsubstituted alkylsulfinyl group having 1 to 30 carbon atoms, 6 to 3
0 substituted or unsubstituted arylsulfinyl groups such as methylsulfinyl, ethylsulfinyl, phenylsulfinyl, p-methylphenylsulfinyl),
Alkyl and arylsulfonyl groups (preferably substituted or unsubstituted alkylsulfonyl groups having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfonyl groups having 6 to 30 carbon atoms, for example, methylsulfonyl, ethylsulfonyl,
Phenylsulfonyl, p-methylphenylsulfonyl), an acyl group (preferably formyl group, a substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, a substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms, Heterocyclic carbonyl group linked to the carbonyl group by 4 to 30 substituted or unsubstituted carbon atoms, for example, acetyl, pivaloyl, 2-chloroacetyl, stearoyl, benzoyl, pn-octyloxyphenylcarbonyl, 2- Pyridylcarbonyl, 2-
Furylcarbonyl), an aryloxycarbonyl group (preferably a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms, for example, phenoxycarbonyl, o-chlorophenoxycarbonyl, m-nitrophenoxycarbonyl, pt-butyl Phenoxycarbonyl), an alkoxycarbonyl group (preferably a substituted or unsubstituted alkoxycarbonyl group having 2 to 30 carbon atoms, for example, methoxycarbonyl, ethoxycarbonyl, t-butoxycarbonyl, n-octadecyloxycarbonyl), a carbamoyl group (preferably , Carbon number 1
To 30 substituted or unsubstituted carbamoyl, such as carbamoyl, N-methylcarbamoyl, N, N-
Dimethylcarbamoyl, N, N-di-n-octylcarbamoyl, N- (methylsulfonyl) carbamoyl),
Aryl and heterocyclic azo groups (preferably substituted or unsubstituted arylazo groups having 6 to 30 carbon atoms,
To 30 substituted or unsubstituted heterocyclic azo groups such as phenylazo, p-chlorophenylazo, 5-ethylthio-1,3,4-thiadiazol-2-ylazo), an imide group (preferably N-succinimide, N
-Phthalimide), a phosphino group (preferably a substituted or unsubstituted phosphino group having 2 to 30 carbon atoms, for example, dimethylphosphino, diphenylphosphino, methylphenoxyphosphino), a phosphinyl group (preferably having 2 to 30 carbon atoms) 30 substituted or unsubstituted phosphinyl groups such as phosphinyl, dioctyloxyphosphinyl, diethoxyphosphinyl) and phosphinyloxy groups (preferably substituted or unsubstituted phosphinyl having 2 to 30 carbon atoms) An oxy group such as diphenoxyphosphinyloxy, dioctyloxyphosphinyloxy), a phosphinylamino group (preferably having 2 carbon atoms);
To 30 substituted or unsubstituted phosphinylamino groups, for example, dimethoxyphosphinylamino, dimethylaminophosphinylamino), phospho group, silyl group (preferably substituted or unsubstituted 3 to 30 carbon atoms). A silyl group such as trimethylsilyl, t-butyldimethylsilyl and phenyldimethylsilyl), a hydrazino group (preferably a substituted or unsubstituted hydrazino group having 0 to 30 carbon atoms such as trimethylhydrazino), a ureido group (preferably carbon Represents a substituted or unsubstituted ureido group of the formulas 0 to 30, for example, N, N-dimethylureido).

Further, a structure in which two substituents V cooperate to form a fused ring may be employed, for example, an aromatic or non-aromatic hydrocarbon ring or a heterocyclic ring. To form a polycyclic fused ring. For example, benzene ring, naphthalene ring, anthracene ring, quinoline ring, phenanthrene ring, fluorene ring, triphenylene ring, naphthacene ring, biphenyl ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, pyridine ring, pyrazine ring,
Pyrimidine ring, pyridazine ring, indolizine ring, indole ring, benzofuran ring, benzothiophene ring, isobenzofuran ring, quinolidine ring, quinoline ring, phthalazine ring, naphthyridine ring, quinoxaline ring, quinoxazoline ring, quinoline ring, carbazole ring, phenanthate Lysine ring, acridine ring, phenanthroline ring, thianthrene ring, chromene ring, xanthene ring, phenoxathiin ring,
Examples include a phenothiazine ring and a phenazine ring.

Among the above functional groups, those having a hydrogen atom may be removed and further substituted with the above group. Examples of such functional groups include alkylcarbonylaminosulfonyl, arylcarbonylaminosulfonyl, alkylsulfonylaminocarbonyl,
An arylsulfonylaminocarbonyl group is exemplified.
Examples include methylsulfonylaminocarbonyl,
p-methylphenylsulfonylaminocarbonyl, acetylaminosulfonyl, and benzoylaminosulfonyl groups.

Next, R represented by R ¹ in the general formula (I)
^1a , R ^1b , R ^1c or R ^1d will be described. In the general formula (I), q represents an integer of 1 or more, preferably 1, 2, 3 or 4, more preferably 1 or 2, and particularly preferably 1.

Q ^a , Q ^b , Q ^c and Q ^d represent a linking group (preferably a divalent linking group). The linking group preferably comprises an atom or an atomic group containing at least one of a carbon atom, a nitrogen atom, a sulfur atom and an oxygen atom. Preferably, an alkylene group (eg, methylene, ethylene, trimethylene, tetramethylene, pentamethylene), an arylene group (eg, phenylene, naphthylene), an alkenylene group (eg, ethenylene, propenylene), an alkynylene group (eg, ethinylene, propynylene), an amide group ,
Ester group, sulfoamide group, sulfonic ester group,
Ureido group, sulfonyl group, sulfinyl group, thioether group, ether group, carbonyl group, -N (Va)-
(Va represents a hydrogen atom or a monovalent substituent. Examples of the monovalent substituent include V described below.), A heterocyclic divalent group (for example, 6-chloro-1,3,5-triazine) −
2,4-diyl group, pyrimidine-2,4-diyl group, and quinoxaline-2,3-diyl group) having one or more of 0 to 100 carbon atoms, preferably 1 to 20 carbon atoms. The following linking groups are represented. However, when these linking groups do not contain a hetero atom,
More preferred.

The above-mentioned linking group may further have a substituent represented by the aforementioned V, and may contain a ring (aromatic or non-aromatic hydrocarbon ring or heterocyclic ring). Good but
It is more preferable that these are not substituted with the substituent represented by V described above.

More preferably, an alkylene group having 1 to 10 carbon atoms (eg, methylene, ethylene, trimethylene, tetramethylene, pentamethylene), an arylene group having 6 to 10 carbon atoms (eg, phenylene, naphthylene), 2 or more carbon atoms A divalent group having 1 to 10 carbon atoms composed of one or more alkenylene groups (eg, ethenylene, propenylene) and alkynylene groups having 2 to 10 carbon atoms (eg, ethinylene, propynylene) Is a linking group. Particularly preferably, one or more combinations of an alkylene group having 1 to 10 carbon atoms (eg, methylene, ethylene, trimethylene, tetramethylene, pentamethylene) and an arylene group having 6 to 10 carbon atoms (eg, phenylene, naphthylene) are used. Is a divalent linking group having 1 to 10 carbon atoms. When Ra, Rb, Rc or Rd is a group containing an aromatic ring, preferably an alkylene group having 1 to 10 carbon atoms (for example, methylene, ethylene,
Trimethylene, tetramethylene, pentamethylene), and more preferably an alkylene group having 1 to 6 carbon atoms (eg, methylene, ethylene, trimethylene, tetramethylene, pentamethylene). These may be substituted with the substituent represented by V described above, but it is more preferable that they are not substituted.

R ^a , R ^b , R ^c , and R ^d represent an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, a heterocyclyloxy group, or an amino group. One.

(1) An unsubstituted alkyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms (eg, methyl, ethyl, propyl,
(2) C1 to C18, preferably C1 to C1
0, more preferably a substituted alkyl group having 1 to 5 carbon atoms (eg, hydroxymethyl, trifluoromethyl, benzyl, carboxyethyl, ethoxycarbonylmethyl, acetylaminomethyl, etc., more preferably 2 to 18 carbon atoms, more preferably An unsaturated hydrocarbon group having 3 to 10 carbon atoms, particularly preferably 3 to 5 carbon atoms (for example, vinyl group, ethynyl group, 1-cyclohexenyl group,
Benzylidene group and benzylidene group) are also included in the substituted alkyl group. (3) having 6 to 20 carbon atoms, preferably 6 to 1 carbon atoms.
5, more preferably a substituted or unsubstituted aryl group having 6 to 10 carbon atoms (for example, phenyl, naphthyl, p-carboxyphenyl, p-nitrophenyl, 3,5-dichlorophenyl, p-cyanophenyl, m-fluorophenyl, (p-tolyl, etc.); (4) having 1 to 20 carbon atoms, preferably 2 to 1 carbon atoms.
0, more preferably an optionally substituted heterocyclic group having 4 to 6 carbon atoms (eg, pyridyl, 5-methylpyridyl,
Thienyl, furyl, morpholino, tetrahydrofurfuryl, etc.);

(5) An alkoxy group having 1 to 10, preferably 1 to 8 carbon atoms (for example, methoxy, ethoxy, 2-methoxyethoxy, 2-hydroxyethoxy,
(6) C6-C20, preferably C6-C1
2, more preferably an aryloxy group having 6 to 10 carbon atoms (for example, phenoxy, p-methylphenoxy, p-
Chlorophenoxy, naphthoxy, etc.); (7) having 1 to 20 carbon atoms, preferably 3 to 1 carbon atoms.
2, more preferably a heterocyclyloxy group having 3 to 10 carbon atoms (which means an oxy group substituted with a heterocyclic group; for example, 2-thienyloxy, 2-morpholinooxy); (8) a carbon number of 0 to 20, preferably Is from 0 to 1 carbon atoms
2, more preferably an amino group having 0 to 8 carbon atoms (eg, amino, methylamino, dimethylamino, ethylamino, diethylamino, hydroxyethylamino, benzylamino, anilino, diphenylamino, ring-formed morpholino, pyrrolidino, etc.) The above-mentioned groups may be further substituted by the aforementioned substituent V.

[0038] In the present invention, at least one of Q ^a and R ^a, at least one of Q ^b and R ^b, at least one of Q ^c and R ^c, at least one of Q ^d and R ^d One is preferably a group containing an aromatic ring.

Next, the aromatic ring will be described in detail. The aromatic ring includes a hydrocarbon aromatic ring and a heteroaromatic ring. These are a hydrocarbon aromatic ring and a polycyclic fused ring in which heteroaromatic rings are fused together, or a ring having a polycyclic fused ring structure in which an aromatic hydrocarbon ring and an aromatic heterocycle are combined. And may be substituted with the above-described substituent V or the like. Preferably as an aromatic ring,
Benzene, naphthalene, anthracene, phenanthrene, fluorene, triphenylene, naphthacene, biphenyl, pyrrole, furan, thiophene, imidazole, oxazole, thiazole, pyridine, pyrazine,
Pyrimidine, pyridazine, indolizine, indole,
Benzofuran, benzothiophene, isobenzofuran,
Examples include quinolidine, quinoline, phthalazine, naphthyridine, quinoxaline, quinoxazoline, quinoline, carbazole, phenanthridine, acridine, phenanthroline, thianthrene, chromene, xanthene, phenoxatiin, phenothiazine, phenazine and the like.
More preferred are the above-mentioned hydrocarbon aromatic rings, and particularly preferred are benzene and naphthalene.

Next, (L ^a ) _h -A ¹ will be described. L
^a represents a linking group, and the linking group includes Q ^a , Q ^b ,
The same as those described as Q ^c and Q ^d are preferable, and the same is preferable. h is 0 or 1, but is preferably 0. A ¹ represents an aromatic group, and the aromatic group is preferably a monovalent group obtained by removing one hydrogen atom from the aromatic ring described in detail above. They are,
It may be substituted with the aforementioned substituent V or the like. Particularly preferred are monovalent groups obtained by removing one hydrogen atom from benzene and naphthalene, that is, a phenyl group and a naphthyl group.

In R ^1a , R ^1b , R ^1c or R ^1d represented by R ¹ in the general formula (I), all of them are represented in a form in which a nitrogen atom is dissociated (N ⁻ ). It is also possible to use the notation (NH). Actually, it becomes dissociated due to the environment such as pH where the dye is placed,
It becomes non-dissociated.

When a cation is present as a counter ion,
For example, it is written as (N ⁻ , Na ⁺ ) or (NH) in a non-dissociated state, but it can also be written as (N ⁻ , H ⁺ ) if the counter ion cation compound is a proton. is there.

Z ¹¹ , Z ¹² , Z ¹³ , Z ¹⁵ , and Z ¹⁷ each represent an atom group necessary for forming a nitrogen-containing heterocyclic ring, preferably a 5- or 6-membered nitrogen-containing heterocyclic ring. However, the rings may be condensed with these. The ring may be either an aromatic ring or a non-aromatic ring. Preferable is an aromatic ring, for example, a hydrocarbon aromatic ring such as a benzene ring and a naphthalene ring, and a heteroaromatic ring such as a pyrazine ring and a thiophene ring.

Examples of the nitrogen-containing heterocyclic ring include thiazoline nucleus, thiazole nucleus, benzothiazole nucleus, oxazoline nucleus, oxazole nucleus, benzoxazole nucleus, selenazoline nucleus,
Selenazole nucleus, benzoselenazole nucleus, tellurazoline nucleus, tellurazole nucleus, benzotellurazole nucleus, 3,3-
A dialkylindolenine nucleus (for example, 3,3-dimethylindolenine), an imidazoline nucleus, an imidazole nucleus, a benzimidazole nucleus, a 2-pyridine nucleus, a 4-pyridine nucleus,
2-quinoline nucleus, 4-quinoline nucleus, 1-isoquinoline nucleus, 3-isoquinoline nucleus, imidazo [4,5-b] quinoxaline nucleus, oxadiazole nucleus, thiadiazole nucleus,
Examples thereof include a tetrazole nucleus and a pyrimidine nucleus, and preferably a benzothiazole nucleus, a benzoxazole nucleus, a 3,3-dialkylindolenine nucleus (for example, 3,3-dimethylindolenine), a benzimidazole nucleus, and a 2-pyridine nucleus. , A 4-pyridine nucleus, a 2-quinoline nucleus, a 4-quinoline nucleus, a 1-isoquinoline nucleus, and a 3-isoquinoline nucleus, and more preferably a benzothiazole nucleus, a benzoxazole nucleus, and a 3,3-dialkylindolenine nucleus (for example, 3 , 3-dimethylindolenine) and a benzoimidazole nucleus, particularly preferably a benzoxazole nucleus, a benzothiazole nucleus and a benzimidazole nucleus, and most preferably a benzoxazole nucleus and a benzothiazole nucleus.

Substituents may be substituted on these nitrogen-containing heterocycles, and examples of the substituent include the substituents represented by V described above. The substituent V on Z ¹¹ , Z ¹² , Z ¹³ , Z ¹⁵ , and Z ¹⁷ is more preferably an alkyl group, an aryl group, an alkoxy group, a halogen atom, or an aromatic ring condensed as the substituent V. .

Specific examples of Z ¹¹ , Z ¹² , Z ¹³ , Z ¹⁵ , and Z ¹⁷ include Z ¹¹ , Z ¹² , Z ^{13 in} columns 23 to 24 of US Pat. No. 5,340,694. , Z ¹⁴ and Z ¹⁶ are the same as those mentioned as examples.

Z ¹⁴ , Z ¹⁴ ′ and (N—R ¹⁴ ) q ¹¹ each together represent an atom group necessary to form a heterocyclic or acyclic acidic terminal group. The heterocyclic ring (preferably a 5- or 6-membered heterocyclic ring) may be any, but an acidic nucleus is preferred. Next, the acidic nucleus and the acyclic acidic terminal group will be described. The acidic nucleus and acyclic acid end groups can take the form of the acidic nucleus and acyclic acid end groups of any common merocyanine dye. In a preferred form, Z ¹⁴ is a thiocarbonyl group, a carbonyl group, an ester group, an acyl group, a carbamoyl group, a cyano group or a sulfonyl group, more preferably a thiocarbonyl group or a carbonyl group. Z ¹⁴ ′ represents the remaining atomic group necessary for forming an acidic nucleus and an acyclic acidic terminal group. When forming an acyclic acidic terminal group, it is preferably a thiocarbonyl group, a carbonyl group, an ester group, an acyl group, a carbamoyl group, a cyano group, a sulfonyl group, or the like. q ¹¹
Is 0 or 1, but preferably 1.

The acidic nucleus and the acyclic acidic terminal group referred to herein are described, for example, in "The Theory of the Photographic Process", edited by James.
Theory of the Photograph
ic Process) 4th edition, Macmillan Publishing Company, 1
977, pp. 198-200. Here, the acyclic acidic terminal group means an acidic or electron-accepting terminal group which does not form a ring. The acidic nucleus and the acyclic acidic end group are, specifically,
U.S. Pat. Nos. 3,567,719 and 3,57.
5,869, 3,804,634,
No. 3,837,862, 4,002,480
No. 4,925,777, Japanese Unexamined Patent Publication No.
No. 167546, U.S. Pat. No. 5,994,051, and U.S. Pat. No. 5,747,236 are mentioned.

The acidic nucleus forms a heterocycle (preferably a 5- or 6-membered nitrogen-containing heterocycle) consisting of carbon, nitrogen and / or chalcogen (typically oxygen, sulfur, selenium and tellurium) atoms. And more preferably a 5- or 6-membered nitrogen-containing heterocyclic ring composed of carbon, nitrogen and / or chalcogen (typically oxygen, sulfur, selenium and tellurium) atoms. Specifically, for example, the following nuclei can be mentioned.

2-pyrazolin-5-one, pyrazolidin-3,5-dione, imidazolin-5-one, hydantoin, 2- or 4-thiohydantoin, 2-iminooxazolidin-4-one, 2-oxazoline-5-one ,
2-thiooxazolidin-2,5-dione, 2-thiooxazoline-2,4-dione, isoxazoline-5
ON, 2-thiazolin-4-one, thiazolidine-4-
On, thiazolidine-2,4-dione, rhodanine, thiazolidine-2,4-dithione, isorhodanine, indan-1,3-dione, thiophen-3-one, thiophen-3-one-1,1-dioxide, indoline- 2
-One, indoline-3-one, 2-oxoindazolinium, 3-oxoindazolinium, 5,7-dioxo-6,7-dihydrothiazolo [3,2-a] pyrimidine, cyclohexane-1,3 -Dione, 3,4-dihydroisoquinolin-4-one, 1,3-dioxane-4,6-dione, barbituric acid, 2-thiobarbituric acid, chroman-2,4-dione, indazolin-2-one , Pyrido [1,2-a] pyrimidine-1,3-dione, pyrazolo [1,5-b] quinazolone, pyrazolo [1,5-a]
Benzimidazole, pyrazolopyridone, 1,2,3
4-tetrahydroquinoline-2,4-dione, 3-oxo-2,3-dihydrobenzo [d] thiophene-1,1
-Dioxide, 3-dicyanomethine-2,3-dihydrobenzo [d] thiophene-1,1-dioxide nucleus.

Further, the carbonyl group or thiocarbonyl group forming these nuclei is substituted at the active methylene position of the acidic nucleus, and the nucleus has an exomethylene structure, and is used as a raw material for an acyclic acidic terminal group. A nucleus having an exomethylene structure substituted at the active methylene position of an active methylene compound having a structure such as ketomethylene or cyanomethylene. When these are written by a general formula, they are expressed as follows.

[0052]

Embedded image

In the formula (XIa), Z ^14a , Z ^14a ′ and (N−R
^14a ) ^{q11a, Z14b} and ^Z14b 'and (N- ^R14b ) ^q11b are
Z ¹⁴ and Z ¹⁴ 'and (N-R ¹⁴⁾ q ¹¹ as synonymous. n
²⁰ is an integer of 0 or more. Otherwise, the general formula (XI)
Is synonymous with n ²⁰ is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0. When n ²⁰ is 2 or more, Z ^14a and Z ^14a 'and ^{(N-R 1 4a) q} 11a need not be identical. However,
A nucleus having a carbonyl group or a thiocarbonyl group is preferable to a nucleus having an exomethylene structure in which the carbonyl group or the thiocarbonyl group is substituted, and a nucleus having a thiocarbonyl group is more preferable. These acidic nuclei and acyclic acidic terminal groups may be substituted or condensed with the substituent or ring represented by the aforementioned substituent V.

As Z ¹⁴ , Z ¹⁴ ′ and (NR ¹⁴ ) q ¹¹ , hydantoin, 2 or 4-thiohydantoin, 2-oxazoline-5-one, 2-thiooxazoline-2,4-dione, Thiazolidine-2,4-dione,
Rhodanine, thiazolidine-2,4-dithione, barbituric acid and 2-thiobarbituric acid, more preferably hydantoin, 2 or 4-thiohydantoin, 2-oxazoline-5-one, rhodanine, barbituric acid, 2-thiobarbituric acid. Particularly preferred are 2 or 4-thiohydantoin, 2-oxazolin-5-one, rhodanine and barbituric acid. Most preferably, it is rhodanine.

The heterocyclic ring formed by Z ¹⁶ , Z ¹⁶ ′ and (NR ¹⁶ ) q ¹² is the same as the heterocyclic ring of Z ¹⁴ , Z ¹⁴ ′ and (NR ¹⁴ ) q ^11. The same ones are mentioned. Preferably, an oxo group or a thioxo group is removed from the acidic nucleus described in the description of the heterocyclic ring of Z ¹⁴ , Z ¹⁴ ′, and (N—R ¹⁴ ) q ¹¹ .

More preferably, the acidic nucleus of Z ¹⁴ , Z ¹⁴ ′ and (N—R ¹⁴ ) q ¹¹ is free of an oxo group or a thioxo group. More preferably, it is a hydantoin. 2, or 4-thiohydantoin,
2-oxazolin-5-one, 2-thiooxazoline-
2,4-dione, thiazolidine-2,4-dione, rhodanine, thiazolidine-2,4-dithione, barbituric acid, 2-thiobarbituric acid obtained by removing an oxo group or a thioxo group, and is particularly preferable. Is hydantoin, 2 or 4-thiohydantoin, 2-oxazolin-5-one, rhodanine, barbituric acid, 2-thiobarbituric acid from which an oxo group or a thioxo group is removed, and most preferably 2 or It is obtained by removing an oxo group or a thioxo group from 4-thiohydantoin, 2-oxazolin-5-one or rhodanine.

Q¹²Is 0 or 1, preferably 1,
is there. R¹¹, R¹², R¹³, R^Fifteen, And R¹⁷Are each independently
An alkyl group, an aryl group, or a heterocyclic group;¹⁴
And R¹⁶Are each independently a hydrogen atom, an alkyl group, an aryl
Or a heterocyclic group. R¹⁴And R¹⁶Preferred as
Or an alkyl group, an aryl group, or a heterocyclic group.
R¹¹, R¹², R¹³, R¹⁴, R^Fifteen, R¹⁶, And R ¹⁷Represented by
As an alkyl group, an aryl group, or a heterocyclic group
Physically, for example, 1 to 18, preferably 1 carbon atoms
To 7, particularly preferably 1 to 4 unsubstituted alkyl groups
(Eg, methyl, ethyl, propyl, isopropyl,
Butyl, isobutyl, hexyl, octyl, dodecyl,
Octadecyl), 1 to 18, preferably 1 carbon atoms
7, particularly preferably 1 to 4 substituted alkyl groups {e.g.
Examples of the substituent include the aforementioned alkyl group substituted by V.
It is. Preferably an aralkyl group (eg benzyl, 2-
Phenylethyl), unsaturated hydrocarbon groups (eg, allyl
Group, vinyl group), hydroxyalkyl group (for example, 2-
Hydroxyethyl, 3-hydroxypropyl), carbo
A xyalkyl group (eg, 2-carboxyethyl, 3-
Carboxypropyl, 4-carboxybutyl, carboxy
Cimethyl), an alkoxyalkyl group (for example, 2-meth
Xyethyl, 2- (2-methoxyethoxy) ethyl),
Aryloxyalkyl group (for example, 2-phenoxyethyl
Ru, 2- (1-naphthoxy) ethyl), alkoxycal
Bonylalkyl group (for example, ethoxycarbonylmethyl,
2-benzyloxycarbonylethyl), aryloxy
Cicarbonylalkyl group (for example, 3-phenoxycarbo
Nylpropyl), an acyloxyalkyl group (for example, 2-
Acetyloxyethyl), an acylalkyl group (for example, 2
-Acetylethyl), carbamoylalkyl group (for example,
2-morpholinocarbonylethyl), sulfamoylua
Alkyl group (for example, N, N-dimethylsulfamoylmethyl)
), A sulfoalkyl group (for example, 2-sulfoethyl,
3-sulfopropyl, 3-sulfobutyl, 4-sulfob
Chill, 2- [3-sulfopropoxy] ethyl, 2-hydr
Roxy-3-sulfopropyl, 3-sulfopropoxye
Toxiethyl), sulfoalkenyl group, sulfatoal
A kill group (for example, a 2-sulfatoethyl group,
Propyl, 4-sulfatobutyl), heterocyclic-substituted
Alkyl group (for example, 2- (pyrrolidin-2-one-1-i
Le) ethyl, tetrahydrofurfuryl), alkylsulfur
Honylcarbamoylalkyl group (for example, methanesulfonyl
Rucarbamoylmethyl group), acylcarbamoylalkyl
(For example, acetylcarbamoylmethyl group), acyl
Sulfamoylalkyl groups (eg, acetylsulfamo
Ylmethyl group), alkylsulfonylsulfamoyl
Alkyl groups (eg, methanesulfonylsulfamoyl)
Methyl group)｝, having 6 to 20 carbon atoms, preferably 6 carbon atoms
To 10, more preferably 6 to 8 carbon atoms.
Reel group (eg, phenyl group, 1-naphthyl group), carbon
Number 6 to 20, preferably 6 to 10 carbon atoms, more preferably
Preferably, a substituted aryl group having 6 to 8 carbon atoms (eg, substituted
The aryl group substituted by V described above as an example of the group is exemplified.
I can do it. Specifically, p-methoxyphenyl group, p-meth
A phenylphenyl group, a p-chlorophenyl group and the like.
You. ), Having 1 to 20 carbon atoms, preferably 3 to 1 carbon atoms.
0, more preferably an unsubstituted heterocyclic group having 4 to 8 carbon atoms
(For example, 2-furyl group, 2-thienyl group, 2-pyridyl
Group, 3-pyrazolyl, 3-isoxazolyl, 3-iso
Thiazolyl, 2-imidazolyl, 2-oxazolyl, 2
-Thiazolyl, 2-pyridazyl, 2-pyrimidyl, 3-
Pyrazyl, 2- (1,3,5-triazolyl), 3- (1,2,4-
Triazolyl), 5-tetrazolyl), having 1-2 carbon atoms
0, preferably 3 to 10, more preferably carbon
A substituted heterocyclic group having a prime number of 4 to 8 (for example,
Heterocyclic groups substituted by the aforementioned substituents V are mentioned.
You. Specifically, a 5-methyl-2-thienyl group, 4-methoxy
An xy-2-pyridyl group and the like can be mentioned. )
You.

In the present invention, the following cases are preferable. (1) When R ¹¹ or R ¹² is substituted with a group represented by R ¹ . More preferably, both R ¹¹ and R ¹² are substituted with the group represented by R ¹ . (2) When R ¹³ or R ¹⁴ is substituted with a group represented by R ¹ . More preferably, R ¹³ is substituted by the group represented by R ¹ . (3) When R ¹⁵ , R ¹⁶ , or R ¹⁷ is substituted with a group represented by R ¹ . More preferably, R ¹⁵ or R ¹⁷ is R
^{When the} group represented by ¹ is substituted.

In the present invention, R¹¹, R¹², R
¹³, R¹⁴, R^Fifteen, R¹⁶, And R¹⁷And R¹Group represented by
Is substituted, then R¹¹, R¹², R¹³,
R¹⁴, R ^Fifteen, R¹⁶, And R¹⁷Is R¹Is synonymous with
And it is preferable that they have the same meaning. At this time,
r, s, t, and u are preferably 1. Furthermore,
R¹¹, R¹³, R^FifteenAnd R¹⁷At least one of which is R¹
Preferably, such a dye is represented by the following general formula
It can be represented by the formula (XX).

[0060]

Embedded image

In the formula (XX), Z ²¹ represents an atom group necessary for forming a nitrogen-containing heterocyclic ring. However, the rings may be condensed with these. Q ²¹ represents a group necessary for the compound represented by the general formula (XX) to form a methine dye. L ⁵¹
And L ⁵² each represents a methine group. p ²¹ represents 0 or 1.
R ¹ , M ¹ , and m ¹ have the same meanings as in formula (I). Z ²¹ is Z
^11, Z ^13, Z ^15, the same nitrogen-containing heterocyclic ring as described in the description of Z ¹⁷ are preferred. Q ²¹ is preferably a group necessary for forming a dye similar to that described in the description of Dye ¹ above. In formula (XX), such as when the cyanine dye by Q ^21, rhodacyanine dyes are formed, it can also be represented by resonance formula as follows.

[0062]

Embedded image

L ¹¹ , L ¹² , L ¹³ , L ¹⁴ , L ¹⁵ , L ¹⁶ , L
^{17, L 18, L 19,} L 20, L 21, L 22, L 23, L 24,
^{L 25, L 26, L 27} , L 28, L 29, L 30, L 51, and L
⁵² independently represents a methine group. L ^{1 to} L ³⁰ ,
The methine groups represented by L ⁵¹ and L ⁵² may have a substituent, and examples of the substituent include the aforementioned V. For example, substituted or unsubstituted C 1 to C 15, preferably C 1
To 10, particularly preferably an alkyl group having 1 to 5 carbon atoms (eg, methyl, ethyl, 2-carboxyethyl),
A substituted or unsubstituted aryl group having 6 to 20 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms (eg, phenyl, o-carboxyphenyl);
A substituted or unsubstituted heterocyclic group having 3 to 20 carbon atoms, preferably 4 to 15 carbon atoms, more preferably 6 to 10 carbon atoms (for example, N, N-dimethylbarbituric acid group), a halogen atom, (for example, chlorine , Bromine, iodine, fluorine), an alkoxy group having 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (eg, methoxy, ethoxy), and 0 to 15 carbon atoms, preferably An amino group having 2 to 10, more preferably 4 to 10 carbon atoms (for example, methylamino, N, N-dimethylamino, N
-Methyl-N-phenylamino, N-methylpiperazino), having 1 to 15 carbon atoms, preferably 1 to 1 carbon atoms.
0, more preferably an alkylthio group having 1 to 5 carbon atoms (eg, methylthio, ethylthio);
An arylthio group having 0, preferably 6 to 12 carbon atoms, more preferably 6 to 10 carbon atoms (for example, phenylthio,
p-methylphenylthio) and the like. It may also form a ring with another methine group, or Z ^{11 to} Z ¹⁷ ,
A ring may be formed together with R ¹ and R ^{11 to} R ¹⁷ .

L ¹¹ , L ¹² , L ¹⁶ , L ¹⁷ , L ¹⁸ , L ¹⁹ , L
²² , L ²³ , L ²⁹ , L ³⁰ , L ⁵¹ and L ⁵² are preferably
It is an unsubstituted methine group. n ¹¹ , n ¹² , n ¹³ and n ¹⁴ each independently represent 0, 1, 2, 3 or 4. Preferably it is 0, 1, 2 or 3. n ¹¹ is more preferably 1, 2 or 3, and particularly preferably 2 or 3.
And most preferably 3. As even more preferably n ^{1 2,} 1, 2 or 3, particularly preferably 2 or 3, most preferably 2. n ¹³ is more preferably 0, 1 or 2, and particularly preferably 1 or 2.
And most preferably 1. n ¹⁴ is more preferably 0, 1 or 2, particularly preferably 0 or 1, and most preferably 0. n ¹¹ , n ¹² , n ¹³
And when n ¹⁴ is 2 or more, the methine group is repeated but need not be the same. p ^11, represents a ^{p 12, p 13, p 14} , p 15 and p ²¹ each independently 0 or 1. Preferably 0
It is.

M¹Is to neutralize the ionic charge of the dye
Indicates the presence of cations or anions when required
Because it is included in the formula. As a typical cation
Are either inorganic or organic cations.
Hydrogen ion (H ⁺), Alkali metal ion
(Eg sodium ion, potassium ion, lithium
Ions), alkaline earth metal ions (for example, calcium
Inorganic ion such as ion, ammonium ion (preferred)
Or ammonium ion, substitution of 1 to 30 carbon atoms
Or unsubstituted alkyl, aryl, or heterocyclic
Ammonium ion (preferably tetraalkyl
Ammonium ion (preferably, tetramethylammonium
Ion), trialkylammonium ion (preferably
Preferably, triethylammonium ion), 1,8-
Diazabicyclo [5.4.0] -7-undeceniumio
), Substituted or unsubstituted cation having 1 to 30 carbon atoms
Heterocyclic ion (preferably pyridinium ion
, Ethyl pyridinium ion))
No. As the anion, an inorganic anion or
Any of organic anions, halogen anions
(For example, fluorine ion, chlorine ion, bromine ion,
Uranium ion), sulfate ion, perchlorate ion, tetraf
Inorganic ions such as fluoroborate ion, substituted aryl
Sulfonate ion (for example, p-toluenesulfonic acid ion
, P-chlorobenzenesulfonate ion), aryl
Disulfonate ion (for example, 1,3-benzenesulfone
Acid ion, 1,5-naphthalenedisulfonic acid ion,
2,6-naphthalenedisulfonic acid ion), alkyl sulfur
Acid ion (eg, methyl sulfate ion), thiocyanate
On, picrate ion, acetate ion, trifluorome
Organic ions such as tansulfonate ion, etc.
You. In addition, it has an opposite charge to the ionic polymer or dye
Other dyes may be used. Also, CO_Two ^-, SO_Three ^-Is
CO with hydrogen ion as counter ion_TwoH, SO_Three
It is also possible to write H. m¹Balances the charge
Indicates the number necessary to perform m¹Is greater than or equal to 2, M¹Is
It need not be the same.

Specific examples of sensitizing dyes (including dyes of general formula (I) and lower concepts) used in the present invention are shown below, but the present invention is not limited thereto.

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Sensitizing dyes (including subordinate dyes) used in the present invention are described in FM Harmer, "Heterocyclic Compounds-Cyanine Soybeans and Relativized Compounds".
Sounds-Cyanine Dyes and Related Compounds), John Wiley & Sons, New York, London, 1964, DMSturmer, Heterocyclic
Heterocyclic Compounds- Special Topics in Heterocyclic Compounds
Special topics in heterocyclic chemistry)
Chapter 8, Section 14, pp. 482-515, John Wiley & Sons, New York, London, 1977, "Rodd's Chemistr."
y of Carbon Compounds) '' 2nd.Ed.vol.IV, partB, 197
Seventh Edition, Chapter 15, Chapters 369-422, Elsevier
Science Public Company, Inc. (Elsevie
r Science Publishing Company Inc.), New York, and the like.

The method of synthesizing the dye used in the present invention will be described below with reference to specific examples. Synthesis Example: Synthesis of Compound (62) Compound (62) was synthesized according to Scheme 1 below. Scheme 1

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Synthesis of Compound (62-a) Toluene 2 was added to 10.3 g of 2-naphthalenesulfonamide.
0 ml, heated in an oil bath set at 110 ° C.,
5.8 g of bromobutyric acid chloride was gradually added dropwise, and after completion of the addition, the mixture was stirred at 110 ° C. for 3 hours while bubbling with nitrogen.
After cooling to room temperature, insolubles were filtered off, and 100 ml of hexane was added to the filtrate. The supernatant of the viscous liquid separated into two layers was removed by decantation, and 100 ml of hexane was added thereto. The precipitated crystals were filtered, and the obtained crystals were washed with hexane and dried under reduced pressure to obtain 16.2 g of Compound (62-a) (yield: 91%).

Synthesis of Compound (62-b) 3.7 g of Compound (62-a) and 7.5 g of 2-methylnaphtho [2.1-d] oxazole were mixed and stirred at 130 ° C. for 11.5 hours. The mixture was allowed to cool to an oil bath temperature of 100 ° C, 10 ml of acetic anhydride and 7.0 g of 1,1,3,3-tetraethoxy-2-methylpropane were added, and the mixture was stirred at an oil bath temperature of 100 ° C for 20 minutes. After allowing to cool to room temperature, the reaction mixture was poured into a mixture of 40 ml of ethyl acetate and 40 ml of hexane, the supernatant of the viscous liquid separated into two layers was removed by decantation, and 40 ml of ethyl acetate was added. The precipitated crystals were filtered, and the obtained crystals were washed with ethyl acetate and dried under reduced pressure to obtain 5.7 g (yield: 45%) of compound (62-b).

Synthesis of Compound (62) 5.1 g of Compound (62-b), 1.
5 g and 20 ml of acetonitrile were mixed, and 3.4 ml of triethylamine was added at room temperature. The reaction mixture was stirred at room temperature for 100 minutes. To this was added 1.8 ml of acetic acid and the resulting mixture was stirred at room temperature for 1 hour. The precipitated crystals were filtered, and the obtained crystals were dissolved in a mixture of 50 ml of methanol and 3.4 ml of triethylamine at room temperature.
Acetic acid (5 ml) was added thereto, and 2-propanol (50) was further added.
ml was added and left for a while at room temperature. The precipitated crystals were collected by filtration, washed with 2-propanol and methanol, and dried under reduced pressure to give 2.9 g of compound (62).
(52% yield). Solution absorption (methanol + one drop of triethylamine) λmax = 595.8 nm, ε = 9150
0.

In the present invention, not only the sensitizing dyes of the general formula (I) but also other sensitizing dyes other than the sensitizing dyes of the general formula (I) may be used or used in combination. Preferred examples of the dye include a cyanine dye, a merocyanine dye, a rhodocyanine dye, a trinuclear merocyanine dye, a tetranuclear merocyanine dye, an allopolar dye, a hemicyanine dye, and a styryl dye. More preferred are cyanine dyes, merocyanine dyes and rhodacyanine dyes, and particularly preferred are cyanine dyes. For more information on these dyes, see FM Harme
r), Heterocyclic Compounds-Cyanine Soybeans and Related Compounds (Heterocyc
lic Compounds-Cyanine Dyes and Related Compound
s) ", John Wiley and Sons
& Sons), New York, London, 1964, DMSturmer, Heterocyclic Compound Special Topics in Heterocyclic Chemistry (Heterocyc)
lic Compounds-Special topics in heterocyclic chemi
stry) ", Chapter 18, Section 14, pages 482 to 515, and the like.

Preferred dyes include those described in US Pat.
Specific examples include sensitizing dyes represented by the general formulas described in U.S. Pat. No. 94,051 at pages 32 to 44 and U.S. Pat. No. 5,747,236 at pages 30 to 39, and specific examples.
The general formulas of preferred cyanine dyes, merocyanine dyes and rhodacyanine dyes are described in US Pat. No. 5,340,69.
(XI), (XII), (X
III) (however, n12, n15, n17, n18
Is not limited and is an integer of 0 or more (preferably 4 or less). ).

One of these sensitizing dyes may be used.
Two or more sensitizing dyes may be used, and a combination of sensitizing dyes is often used particularly for supersensitization. Representative examples are U.S. Pat. Nos. 2,688,545 and 2,977,2.
No. 29, 3,397,060, 3,
522,052, 3,527,641, 3,617,293, 3,628,9
Nos. 64, 3,666,480, 3,
672,898, 3,679,428, 3,303,377, 3,769,3
No. 01, 3,814, 609, 3,
837,862, 4,026,707, British Patent 1,344,281, 1,50
7,803, JP-B-43-49336,
No. 53-12375, JP-A-52-110618
And JP-A-52-109925. In addition to the sensitizing dye, the emulsion may contain a dye which does not itself have a spectral sensitizing effect or a substance which does not substantially absorb visible light and exhibits supersensitization.

Supersensitizers useful for spectral sensitization in the present invention (for example, pyrimidylamino compounds, triazinylamino compounds, azolium compounds, aminostyryl compounds, aromatic organic acid formaldehyde condensates, azaindene compounds, cadmium salts) And combinations of supersensitizers and sensitizing dyes are described, for example, in US Pat. No. 3,511,66.
Nos. 4, 3,615, 613, 3, 6
15,632, 3,615,641, 4,596,767, 4,945,0
No. 38, No. 4,965,182, No. 4,
965,182, 2,933,390, 3,635,721, 3,743,5
No. 10, No. 3,617,295, No. 3,
It is described in, for example, 635,721, and the use thereof is preferably the method described in the above patent.

The timing at which the sensitizing dye of the general formula (I) used in the present invention (also the other sensitizing dyes and supersensitizers) is added to the silver halide emulsion has been useful. It can be during any process of emulsion preparation which has been found to be acceptable. For example, US Pat.
No. 66, 3,628,960, 4,
183,756, 4,225,666, JP-A-58-184142, and 60-196.
As disclosed in Japanese Patent No. 749 and the like, the timing before silver halide grain formation step and / or before desalting, the timing during and / or after desalting and before the start of chemical ripening, As disclosed in JP-A-58-113920 and the like, at any time before or during the time of chemical ripening or during the process, and before the application of the emulsion after the chemical ripening and before coating, it can be added in the process. Is also good. Also, U.S. Pat.
As disclosed in US Pat. No. 5,666, JP-A-58-7629 and the like, the same compound may be used alone or in combination with a compound having a different structure, for example, during the particle forming step and during the chemical ripening step. Alternatively, it may be added separately after the completion of the chemical ripening, or before or after the completion of the chemical ripening, or during the process, and may be added separately. May be added.

The amount of the sensitizing dye of the general formula (I) used in the present invention (the same applies to other sensitizing dyes and supersensitizers) depends on the sensitivity and fog performance, system environment dependency, The desired amount can be obtained depending on the shape and size of the silver halide grains, but is preferably from 10 ^-6 to 1 mol, more preferably from 10 ^-4 to 10 ^-1 mol, per mol of silver halide in the photosensitive layer. It is.

The sensitizing dye of the formula (I) used in the present invention (the same applies to other sensitizing dyes and supersensitizers) can be directly dispersed in the emulsion. These can be first dissolved in an appropriate solvent, for example, methyl alcohol, ethyl alcohol, methyl cellosolve, acetone, water, pyridine or a mixed solvent thereof, and added to the emulsion in the form of a solution. At this time, additives such as a base, an acid, and a surfactant can be made to coexist. Also, ultrasonic waves can be used for dissolution. Further, as a method for adding this compound, US Pat.
No. 9,987, etc., a method in which the compound is dissolved in a volatile organic solvent, the solution is dispersed in a hydrophilic colloid, and this dispersion is added to an emulsion.
As described in JP-A-6-24185 and the like, a method of dispersing in a water-soluble solvent and adding this dispersion to an emulsion, as described in US Pat. No. 3,822,135,
A method in which a compound is dissolved in a surfactant, and the solution is added to the emulsion. As described in JP-A-50-80826, a method of dissolving a compound in an acid substantially free of water and adding the solution to an emulsion is used. In addition, US Pat.
2,343, 3,342,605,
2,996,287 and 3,429,835
The method described in the specification can be used.

The photothermographic material of the present invention will be described in more detail below. The organic silver salt that can be used in the present invention is relatively stable to light, but at 80 ° C. or less in the presence of an exposed photocatalyst (such as a latent image of a photosensitive silver halide) and a reducing agent. A silver salt that forms a silver image when heated as described above. The organic silver salt can be any organic substance including a source capable of reducing silver ions. Such non-photosensitive organic silver salts are described in paragraphs 0048 to 0049 of JP-A-10-62899, European Patent Publication No. 080376.
No. 4A1, page 18, line 24 to page 19, page 3
Seven lines, EP 0 986 812 A1. Silver salts of organic acids, especially (C 10-30, preferably 1
Silver salts of long chain aliphatic carboxylic acids (5-28) are preferred. Preferred examples of the organic silver salt include silver behenate, silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, and mixtures thereof. In the present invention, among these organic silver salts, it is preferable to use an organic acid silver salt having a silver behenate content of 75 mol% or more.

The shape of the organic silver salt that can be used in the present invention is not particularly limited, and may be needle-like, rod-like, plate-like, or flake-like. In the present invention, scaly organic silver salts are preferred. In the present specification, the scaly organic silver salt is defined as follows. The silver salt of the organic acid was observed with an electron microscope, and the shape of the silver salt of the organic acid was approximated to a rectangular parallelepiped.
May be the same as b. ) When the shorter numerical value a,
Calculate with b and obtain x as follows. x = b / a As described above, x is obtained for about 200 particles, and as an average value x (average), those satisfying a relationship of x (average) ≧ 1.5 are regarded as scaly. Preferably 30 ≧ x
(Average) ≧ 1.5, more preferably 20 ≧ x (average) ≧ 2.0. Incidentally, the needle shape is 1 ≦ x (average) <1.5.

In the scaly particles, a can be regarded as the thickness of tabular particles having a main plane with b and c as the sides. The average of a is preferably 0.01 μm or more and 0.23 μm, more preferably 0.1 μm.
It is more preferably at least 0.20 μm. The average of c / b is preferably 1 or more and 6 or less, more preferably 1.05 or more and 4 or less,
It is more preferably 1.1 or more and 3 or less, particularly preferably 1.1 or more and 2 or less.

The particle size distribution of the organic silver salt is preferably monodispersed. Monodisperse and the minor axis, the standard deviation of the length of each major axis is 100% or less, preferably 100% or less, more preferably 80% or less, more preferably 50% of the value obtained by dividing the standard deviation of the length of each major axis by the minor axis. It is as follows. The shape of the organic silver salt can be measured from a transmission electron microscope image of the organic silver salt dispersion. Another way to measure monodispersity is
There is a method of calculating the standard deviation of the volume-weighted average diameter of an organic silver salt, and the percentage of the value divided by the volume-weighted average diameter (coefficient of variation)
Is preferably 100% or less, more preferably 80% or less, and still more preferably 50% or less. As a measuring method, for example, the particle size (volume weighted average diameter) obtained by irradiating a laser beam to an organic silver salt dispersed in a liquid and obtaining an autocorrelation function with respect to a time change of fluctuation of the scattered light is obtained. Can be.

Known methods can be applied to the production of the organic acid silver used in the present invention and its dispersion method. For example, the above-mentioned JP-A-10-62899, European Patent Publication 080376
Reference can be made to 3A1 and European Patent Publication 962812A1. In addition, when a photosensitive silver salt is present at the time of dispersion of an organic silver salt, fog increases and sensitivity is significantly reduced. Therefore, it is more preferable that the photosensitive silver salt is not substantially contained at the time of dispersion. In the present invention, the amount of the photosensitive silver salt in the aqueous dispersion to be dispersed is 0.1 mol% or less based on 1 mol of the organic acid silver salt in the liquid. Not something.

In the present invention, it is possible to produce a photosensitive material by mixing an aqueous dispersion of an organic silver salt and an aqueous dispersion of a photosensitive silver salt. You can choose, but the ratio of photosensitive silver salt to organic silver salt is 1
~ 30 mol% is preferred, more preferably 3 ~ 20 mol%, especially 5 ~
A range of 15 mol% is preferred. Mixing two or more aqueous dispersions of organic silver salts with two or more aqueous dispersions of photosensitive silver salts during mixing is a method preferably used for adjusting photographic characteristics. The organic silver salt in the present invention can be used in a desired amount, preferably 0.1-5 g / m ² as silver amount, more preferably from 1 to 3 g / m ^2.

The photothermographic material of the present invention contains a reducing agent for an organic silver salt. A reducing agent for an organic silver salt is any substance (preferably an organic substance) that reduces silver ions to metallic silver.
It may be. Such reducing agents are described in paragraphs 0043 to 0045 of JP-A-11-65021 and European Patent Publication No.
No. 0803764A1, page 7, line 34 to page 18, line 12. In the present invention, the reducing agent is preferably a bisphenol reducing agent, and more preferably a compound represented by the following general formula (Ia).

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In the general formula (Ia), R ^1a and R ^1a ′
Each independently represents an alkyl group having 1 to 20 carbon atoms. R ^2a and R ^2a ′ each independently represent a hydrogen atom or a substituent that can be substituted on a benzene ring. L _d represents a —S— group or a —CHR ^3a — group. R ^3a represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Xa and Xa 'each independently represent a hydrogen atom or a group that can be substituted on a benzene ring.

The general formula (Ia) will be described in detail.
R ^1a and R ^1a ′ are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. The alkyl group may be linear, branched, cyclic, or a combination thereof. The substituent of the alkyl group is not particularly limited, but is preferably an aryl group, a hydroxy group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acylamino group, a sulfonamide group, a sulfonyl group, a phosphoryl group, Examples include an acyl group, a carbamoyl group, an ester group, and a halogen atom.

R ^2a and R ^2a ′ each independently represent a hydrogen atom or a substituent that can be substituted on a benzene ring;
a ′ also independently represents a hydrogen atom or a group that can be substituted on a benzene ring. Preferred examples of the group that can be substituted on a benzene ring include an alkyl group, an aryl group, a halogen atom, an alkoxy group, and an acylamino group.

Ld represents a —S— group or a —CHR ^3a — group. R ^3a represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. The alkyl group may be linear, branched, cyclic, or a combination thereof. The alkyl group may have a substituent. Specific examples of the unsubstituted alkyl group for R ^3a include a methyl group, an ethyl group, a propyl group, a butyl group, a heptyl group, an undecyl group, an isopropyl group, a 1-ethylpentyl group, and a 2,4,4-trimethylpentyl group. can give. Examples of the substituent of the alkyl group are the same as the substituent of R ^1a , and include a halogen atom, an alkoxy group, an alkylthio group, an aryloxy group, an arylthio group, an acylamino group, a sulfonamide group, a sulfonyl group, a phosphoryl group, an oxycarbonyl group, Examples include a carbamoyl group and a sulfamoyl group.

R ^1a and R ^1a ′ preferably have 3 carbon atoms
~ 15 secondary or tertiary alkyl groups, specifically, isopropyl, isobutyl, t-butyl, t-
Examples thereof include an amyl group, a t-octyl group, a cyclohexyl group, a cyclopentyl group, a 1-methylcyclohexyl group, and a 1-methylcyclopropyl group. R ^1a and R ^1a ′ are more preferably tertiary alkyl groups having 4 to 12 carbon atoms, among which t-butyl, t-amyl, and 1-methylcyclohexyl are more preferred, and t-butyl is most preferred. .

R ^2a and R ^2a ′ preferably have 1 carbon atom
To 20 alkyl groups, specifically, methyl, ethyl, propyl, butyl, isopropyl, t-butyl, t-amyl, cyclohexyl, 1-methylcyclohexyl, benzyl, methoxy Examples include a methyl group and a methoxyethyl group. More preferred are a methyl group, an ethyl group, a propyl group, an isopropyl group and a t-butyl group. Xa and Xa 'are preferably a hydrogen atom, a halogen atom, or an alkyl group, and more preferably a hydrogen atom.

Ld is preferably a —CHR ^3a — group. R ^3a is preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, wherein the alkyl group is a methyl group, an ethyl group,
A propyl group, an isopropyl group and a 2,4,4-trimethylpentyl group are preferred. Particularly preferred as R ^3a is a hydrogen atom, a methyl group, an ethyl group or a propyl group.

When R ^3a is a hydrogen atom, R ^2a and R ^2a ′
Is preferably an alkyl group having 2 to 5 carbon atoms, more preferably an ethyl group or a propyl group, and most preferably an ethyl group. When R ^3a is a primary or secondary alkyl group having 1 to 8 carbon atoms, R ^2a and R ^2a ′ are preferably methyl groups. R ^3a
As the primary or secondary alkyl group having 1 to 8 carbon atoms, a methyl group, an ethyl group, a propyl group, and an isopropyl group are more preferable, and a methyl group, an ethyl group, and a propyl group are more preferable. The general formula (I) which can be used in the present invention is described below.
Specific examples of the compound represented by a) are shown below, but it should not be construed that the invention is limited thereto.

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In the present invention, the amount of the reducing agent added is from 0.01 to 5.
Is preferably 0 g / m ^2, more preferably from 0.1 to 3.0 g / m ^2, preferably contained 5-50 mol% per mol of silver on the side having the image forming layer, 10 ~Four
More preferably, it is contained at 0 mol%. The reducing agent is preferably contained in the image forming layer. The reducing agent may be contained in the coating solution by any method such as a solution form, an emulsified dispersion form, and a solid fine particle dispersion form, and may be contained in the photosensitive material. Well-known emulsification dispersion methods include dissolving oils such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, and auxiliary solvents such as ethyl acetate and cyclohexanone to mechanically produce an emulsified dispersion. Method.

In the solid fine particle dispersion method, a powder of a reducing agent is dispersed in a suitable solvent such as water by a ball mill, a colloid mill, a vibrating ball mill, a sand mill, a jet mill, a roller mill, or ultrasonic waves to obtain a solid dispersion. The method of making is mentioned. In this case, a protective colloid (for example, polyvinyl alcohol) and a surfactant (for example, an anionic surfactant such as sodium triisopropylnaphthalenesulfonate (a mixture of three isopropyl groups having different substitution positions)) may be used. Good. The aqueous dispersion can contain a preservative (eg, benzoisothiazolinone sodium salt). In the photothermographic material of the present invention, a phenol derivative represented by the formula (A) described in Japanese Patent Application No. 11-73951 is preferably used as a development accelerator.

When the reducing agent in the present invention has an aromatic hydroxyl group (—OH), particularly in the case of the above-mentioned bisphenols, a non-reducing agent having a group capable of forming a hydrogen bond with these groups is used. It is preferable to use a compound having an acidic property. Examples of the group that forms a hydrogen bond with a hydroxyl group or an amino group include a phosphoryl group, a sulfoxide group, a sulfonyl group, a carbonyl group, an amide group, an ester group, an urethane group, a ureido group, a tertiary amino group, and a nitrogen-containing aromatic group. No. Among them, preferred are a phosphoryl group, a sulfoxide group and an amide group (provided that they have no> NH group,
> NR (R is a substituent other than H). ), Urethane group (provided that it does not have a> NH group,
> NR (R is a substituent other than H). ), Ureido group (provided that it has no> NH group,
> NR (R is a substituent other than H). ). In the present invention, a particularly preferred hydrogen bonding compound is a compound represented by the following general formula (IIa).

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In formula (IIa), R ^11a , R ^12a and R ^13a each independently represent an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group or a heterocyclic group, and these groups are unsubstituted. And it may have a substituent. When R ^11a , R ^12a and R ^13a have a substituent, examples of the substituent include a halogen atom, an alkyl group, an aryl group, an alkoxy group, an amino group, an acyl group, an acylamino group, an alkylthio group, an arylthio group, a sulfonamide group, An acyloxy group, an oxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, a phosphoryl group, and the like can be mentioned. Preferred substituents are an alkyl group or an aryl group such as a methyl group, an ethyl group,
Examples include an isopropyl group, a t-butyl group, a t-octyl group, a phenyl group, a 4-alkoxyphenyl group, and a 4-acyloxyphenyl group. R ^11a , R ^12a and R ^13a
The alkyl group is preferably a substituted, unsubstituted alkyl group having 1 to 20 carbon atoms, such as a straight-chain, branched-chain, cyclic or combination thereof, and specifically, a methyl group, an ethyl group, a butyl group, an octyl group , Dodecyl, isopropyl, t-butyl, t-amyl, t-octyl, cyclohexyl, 1-methylcyclohexyl, benzyl, phenethyl and 2-phenoxypropyl. Examples of the aryl group include a phenyl group, a cresyl group, a xylyl group, a naphthyl group, a 4-t-butylphenyl group, a 4-t-octylphenyl group, a 4-anisidyl group,
Examples include a 3,5-dichlorophenyl group. As the aryl group, a monocyclic or polycyclic substituted or unsubstituted aryl group having 6 to 20 carbon atoms is preferable, and a phenyl group, a cresyl group, a xylyl group, a naphthyl group, a 4-t-butylphenyl group, a 4-t -Octylphenyl group, 4-anisidyl group, 3,5-dichlorophenyl group and the like.

The alkoxy group is preferably a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, such as a straight-chain, branched-chain, cyclic or combination thereof, and is preferably a methoxy group, an ethoxy group, a butoxy group, an octyloxy group, -Ethylhexyloxy group, 3,5,5-trimethylhexyloxy group, dodecyloxy group, cyclohexyloxy group, 4-
Examples include a methylcyclohexyloxy group and a benzyloxy group. The aryloxy group has 6 to 20 carbon atoms.
Are preferred, and examples thereof include a phenoxy group, a cresyloxy group, an isopropylphenoxy group, a 4-t-butylphenoxy group, a naphthoxy group, and a biphenyloxy group. As the amino group, an amino group having 0 to 20 carbon atoms is preferable, and a dimethylamino group, a diethylamino group, a dibutylamino group, a dioctylamino group, an N-methyl-N-hexylamino group, a dicyclohexylamino group, a diphenylamino group, And a methyl-N-phenylamino group. The heterocyclic group is a 3- to 10-membered saturated or unsaturated heterocyclic group containing at least one of N, O and S atoms, which may be a monocyclic ring or a heterocyclic group. A condensed ring may be formed. Specific examples of the heterocycle in the heterocyclic group include, for example, pyrrolidine, piperidine, piperazine, morpholine,
Thiophene, furan, pyrrole, imidazole, pyrazole, pyridine, pyrimidine, pyrazine, pyridazine,
Triazole, triazine, indole, indazole, purine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, thiazole,
Oxazole, benzimidazole, benzoxazole, benzthiazole, benzselenazole, indolenine, tetrazaindene and the like.

R ^11a and R ^12a , R ^12a and R ^13a or R ^11a
And R ^12a and R ^13a together can represent an optionally substituted monocyclic or polycyclic hydrocarbon group. R
^{As 11a} , ^R12a and ^R13a , an alkyl group, an aryl group, an alkoxy group and an aryloxy group are preferred. From the viewpoint of the effects of the present invention, at least one of R ^11a , R ^12a and R ^13a is preferably an alkyl group or an aryl group, and more preferably two or more are an alkyl group or an aryl group. In addition, it is preferable that R ^11a , R ^12a and R ^13a are the same group in that they can be obtained at low cost. Specific examples of the compound of the general formula (IIa) that can be used in the present invention are shown below, but the invention is not limited thereto.

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The compound of the formula (IIa) can be contained in a coating solution in the form of a solution, an emulsified dispersion or a solid-dispersed fine particle dispersion as in the case of the reducing agent, and used in a light-sensitive material. The compound of the general formula (IIa) forms a hydrogen bonding complex with a compound having a phenolic hydroxyl group or an amino group in a solution state, and depending on the combination of the reducing agent and the compound of the general formula (IIa), a complex may be formed. It can be isolated in crystalline form. It is particularly preferable to use the crystal powder isolated in this way as a solid dispersion fine particle dispersion in order to obtain stable performance. Further, a method in which the reducing agent and the compound of the formula (IIa) are mixed in a powder form, and a complex is formed at the time of dispersion by a sand grinder mill or the like using an appropriate dispersant can also be preferably used. General formula (II
The compound of a) is preferably used in a range of 1 to 200 mol%, more preferably 10 to 1 mol%, based on the reducing agent.
It is in the range of 50 mol%, more preferably in the range of 30 to 100 mol%.

The photosensitive silver halide used in the present invention is not particularly limited as a halogen composition, and silver chloride, silver chlorobromide, silver bromide, silver iodobromide, and silver iodochlorobromide can be used. . The distribution of the halogen composition in the grains may be uniform, the halogen composition may be changed stepwise, or may be changed continuously. Further, silver halide grains having a core / shell structure can be preferably used. The preferred structure is
The core has a double / five-layer structure, and more preferably has a double / four-layer structure.
Shell particles can be used. A technique for localizing silver bromide on the surface of silver chloride or silver chlorobromide grains can also be preferably used.

Methods for forming light-sensitive silver halide are well known in the art, for example, Research Disclosure No. 17029, June 1978, and US Pat. No. 3,700,45.
The method described in No. 8 can be used, but specifically, a photosensitive silver halide is prepared by adding a silver supply compound and a halogen supply compound to gelatin or another polymer solution, Thereafter, a method of mixing with an organic silver salt is used. Also, the method described in paragraphs 0217 to 0224 of JP-A-11-119374,
The methods described in Japanese Patent Application Nos. 11-98708 and 11-84182 are also preferable.

The grain size of the photosensitive silver halide is preferably small for the purpose of suppressing the white turbidity after image formation, specifically 200 nm or less, more preferably 5 nm or less.
nm to 150 nm, preferably 10 nm to 120 nm, more preferably 10 nm to 50 nm.
nm or less, particularly preferably 20 nm or more and 50 nm or less. The grain size as used herein means a diameter when converted into a circular image having the same area as the projected area of a silver halide grain (in the case of a tabular grain, the projected area of a main plane). Examples of the shape of silver halide grains include cubic, octahedral, tabular grains, spherical grains, rod-like grains, potato-like grains, and the like, and cubic grains are particularly preferred in the invention.
Grains having rounded corners of silver halide grains can also be preferably used. The surface index (mirror index) of the outer surface of the photosensitive silver halide grains is not particularly limited,
High spectral sensitization efficiency when the spectral sensitizing dye is adsorbed [10
It is preferable that the ratio occupied by the [0] plane is high. The ratio is preferably 50% or more, more preferably 65% or more, and 80%
The above is more preferred. The Miller index [100] plane ratio was determined by T. Tani; J. Imaging Sci., 29, 165 (1985) using the dependence of the adsorption of sensitizing dyes on the [111] and [100] planes. It can be determined by the method described.

In the present invention, silver halide grains having a hexacyano metal complex present on the outermost surface of the grains are preferred. Hexacyano metal complexes include [Fe (CN) ₆ ] ^4- , [Fe (CN) ₆ ] ^3- ,
[Ru (CN) ₆ ] ^4- , [Os (CN) ₆ ] ^4- , [Co (CN) ₆ ] ^3- , [Rh (C
^{_{N) 6] 3-, [Ir}} (CN) 6] 3-, [Cr (CN) 6] 3 -, and the like ^{_{3- [Re (CN) 6]}} . In the present invention, a hexacyano Fe complex is preferred. Since the hexacyano metal complex exists in the form of ions in an aqueous solution, its counter cation is not important, but it is easily miscible with water and is compatible with the precipitation operation of silver halide emulsions, sodium ion, potassium ion, rubidium. It is preferable to use an alkali metal ion such as an ion, a cesium ion and a lithium ion, an ammonium ion, and an alkylammonium ion (for example, a tetramethylammonium ion, a tetraethylammonium ion, a tetrapropylammonium ion, and a tetra (n-butyl) ammonium ion).

The hexacyano metal complex may be used in combination with water or a suitable water-miscible organic solvent (eg, alcohols, ethers, glycols, ketones, esters, amides, etc.) or gelatin. And can be added as a mixture. The amount of hexacyano metal complex added is per mole of silver.
It is preferably from 1 × 10 ⁻⁵ mol to 1 × 10 ⁻² mol, more preferably from 1 × 10 ⁻⁴ mol to 1 × 10 ⁻³ mol. In order for the hexacyano metal complex to be present on the outermost surface of the silver halide grains, the addition of the hexacyano metal complex to the silver nitrate aqueous solution used for grain formation is followed by sulfur sensitization, selenium sensitization, and chalcogen sensitization of tellurium sensitization. It is added directly before the completion of the preparation step before the chemical sensitization step for performing noble metal sensitization such as sensitization or gold sensitization, during the washing step, during the dispersion step, or before the chemical sensitization step. In order not to grow silver halide fine grains,
It is preferable to add the hexacyano metal complex immediately after the particle formation, and it is preferable to add the hexacyano metal complex before the end of the charging step.

Incidentally, the addition of the hexacyano metal complex may be started after 96% by mass of the total amount of silver nitrate added for grain formation, or started after 98% by mass is added. More preferably, it is particularly preferable after adding 99% by mass. When these hexacyano metal complexes are added after the addition of the aqueous silver nitrate solution immediately before the completion of grain formation, they can be adsorbed on the outermost surface of the silver halide grains, and most of them form hardly soluble salts with silver ions on the grain surface. I do. Since the silver salt of hexacyanoiron (II) is a harder-soluble salt than AgI, re-dissolution by fine particles can be prevented, and silver halide fine particles having a small particle size can be produced. .

The photosensitive silver halide grains to be used in the present invention are selected from groups 8 to 10 of the periodic table (showing groups 1 to 18).
A group metal or metal complex can be included. Rhodium, ruthenium, and iridium are preferable as the metals of Groups 8 to 10 of the periodic table or the central metal of the metal complex. One kind of these metal complexes may be used, or two or more kinds of complexes of the same metal and different metals may be used in combination. The preferred content is in the range of 1 × 10 ^-9 mol to 1 × 10 ^-3 mol per mol of silver. These heavy metals and metal complexes and their addition methods are described in JP-A-7-225449 and JP-A-11-225449.
-65021, paragraphs 0018 to 0024, JP-A-11-119374
No. 0227 to 0240 in the publication. Further, a metal atom (for example, [Fe (CN) ₆ ] ^4- ) which can be contained in the silver halide grains used in the present invention, and a desalting method and a chemical sensitizing method of a silver halide emulsion are described in No. 84574, paragraphs 0046 to 0050, JP-A-11-65021, paragraphs 0025 to 0031, JP-A-11-119374, paragraph 0
242-0250.

As the gelatin contained in the photosensitive silver halide emulsion used in the present invention, various gelatins can be used. In order to maintain a good dispersion state of the photosensitive silver halide emulsion in the coating solution containing an organic silver salt, it is preferable to use low molecular weight gelatin having a molecular weight of 500 to 60,000. These low-molecular-weight gelatins may be used at the time of grain formation or at the time of dispersion after desalting, but are preferably used at the time of dispersion after desalting.

The method of using the sensitizing dye is described above, and will be further described. The sensitizing dye applicable to the present invention is a sensitizing dye capable of spectrally sensitizing silver halide grains in a desired wavelength region when adsorbed on silver halide grains, and having a spectral sensitivity suitable for the spectral characteristics of an exposure light source. Dyes can be advantageously selected. For the sensitizing dye and the method of addition, JP-A-11-65021, paragraphs 0103 to
0109, the compound represented by the general formula (II) of JP-A-10-186572, the dye represented by the general formula (I) of JP-A-11-119374 and paragraph No. 0106, U.S. Patent No. 5,510,236 The dye described in Example 5 of the specification of JP-A-3,871,887,
JP-A-2-96131, dyes disclosed in JP-A-59-48753, No. 19 of EP-A-0 080 364 A1
It is described in page 38, line 20 to page 20, line 35, Japanese Patent Application No. 2000-86865, Japanese Patent Application No. 2000-102560, and the like.
These sensitizing dyes may be used alone or in combination of two or more. In the present invention, the time when the sensitizing dye is added to the silver halide emulsion is preferably after the desalting step and before coating, and more preferably after desalting and before the start of chemical ripening. The addition amount of the sensitizing dye in the present invention can be a desired amount in accordance with the sensitivity and the performance of fog.
It is preferably 10 ^-6 to 1 mol, more preferably 10 ^-4 to 10 ^-1.
Is a mole.

In the present invention, in order to improve the spectral sensitization efficiency,
Supersensitizers can be used. As the supersensitizer used in the present invention, EP-A-587,338, U.S. Pat.No. 3,877,943, U.S. Pat. Id 10-111543
And the compounds described in Japanese Unexamined Patent Publication (KOKAI) No. HEI 9-86.

The photosensitive silver halide grains used in the present invention are preferably chemically sensitized by a sulfur sensitization method, a selenium sensitization method, or a tellurium sensitization method. As the compound preferably used in the sulfur sensitization method, the selenium sensitization method, and the tellurium sensitization method, known compounds, for example, compounds described in JP-A-7-128768 can be used. In particular, tellurium sensitization is preferable in the present invention, and compounds described in JP-A-11-65021, paragraph number 0030, compounds described in JP-A-5-313284, general formulas (II), (III), (III) Compounds represented by IV) are more preferred.

In the present invention, chemical sensitization can be performed at any time after grain formation and before coating, and after desalting, (1) before spectral sensitization, (2) simultaneously with spectral sensitization, ( 3) After spectral sensitization, (4) immediately before coating, and the like. In particular, it is preferably performed after spectral sensitization. The amount of the sulfur, selenium and tellurium sensitizers used in the present invention varies depending on the silver halide grains used, the conditions of chemical ripening, etc., but is preferably 10 ^-8 to 10 ^-2 mol, and more preferably 10 ^-8 to 10 ^-2 mol per mol of silver halide. 10 ^-7 ~
About 10 ^-3 mol is used. The conditions for chemical sensitization in the present invention are not particularly limited, but the pH is 5 to 8, p
Ag is about 6 to 11, and temperature is about 40 to 95 ° C. A thiosulfonic acid compound may be added to the silver halide emulsion used in the present invention according to the method disclosed in European Patent Publication No. 293,917.

The light-sensitive silver halide emulsion in the photothermographic material of the present invention may be of one kind or two or more kinds (eg, those having different average grain sizes, different halogen compositions, different crystal habits). And those having different conditions of chemical sensitization). The gradation can be adjusted by using a plurality of photosensitive silver halides having different sensitivities. Japanese Patent Application Laid-Open Nos. 57-119341 and 5
No. 3-106125, No. 47-3929, No. 48-55730, No. 46-5187, No. 50-73627, No. 57-150841
And the like. It is preferable that each emulsion has a difference of 0.2 logE or more as a sensitivity difference.

[0138] The addition amount of the photosensitive silver halide, when expressed by the amount of coated silver per photosensitive material 1 m ^2, it is preferably 0.03~0.6g / m ^2, is 0.05 to 0.4 g / m ² more preferably, and most preferably from 0.1 to 0.4 g / m ^2, relative to the organic silver salt to 1 mole of the photosensitive silver halide is preferably 0.01 mol to 0.5 mol, and more is 0.02 mol to 0.3 mol preferable.

With respect to the mixing method and mixing conditions of the separately prepared photosensitive silver halide and organic silver salt, the silver halide particles and organic silver salt which have been respectively prepared are mixed with a high-speed stirrer, a ball mill, a sand mill, a colloid mill, and a vibrator. Mills, a method of mixing with a homogenizer, etc., or a method of preparing an organic silver salt by mixing photosensitive silver halide prepared at any timing during the preparation of the organic silver salt, etc. There is no particular limitation as long as the effect appears sufficiently. In addition, mixing two or more kinds of aqueous dispersions of organic silver salts and two or more kinds of aqueous dispersions of photosensitive silver salts is a preferable method for controlling photographic characteristics. The preferred timing of adding silver halide to the image forming layer coating solution is from 180 minutes to immediately before coating, preferably from 60 minutes to 1 minute.
Before 0 seconds, there is no particular limitation on the mixing method and mixing conditions as long as the effects of the present invention are sufficiently exhibited. As a specific mixing method, a method of mixing in a tank such that the average residence time calculated from the addition flow rate and the amount of liquid sent to the coater is a desired time or N. Harnby, MFEdwa
rds, AWNienow, translated by Koji Takahashi, "Liquid Mixing Technology" (published by Nikkan Kogyo Shimbun, 1989).

The binder for the organic silver salt-containing layer in the photothermographic material of the present invention may be any polymer. Suitable binders are transparent or translucent, generally colorless, and include natural resins, polymers and copolymers, and synthetic resins. Resins, polymers and copolymers, and other film-forming media, such as gelatins, rubbers, poly (vinyl alcohol) s, hydroxyethyl celluloses, cellulose acetates, cellulose acetate butyrate,
Poly (vinylpyrrolidone), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid),
Poly (vinyl chloride) s, poly (methacrylic acid) s, styrene-maleic anhydride copolymers, styrene-acrylonitrile copolymers, styrene-butadiene copolymers, poly (vinyl acetal) s (for example, poly (Vinyl formal) and poly (vinyl butyral)), poly (ester) s, poly (urethane) s, phenoxy resins, poly (vinylidene chloride) s, poly (epoxides)
, Poly (carbonate) s, poly (vinyl acetate) s,
There are poly (olefins), cellulose esters, and poly (amides). The binder may be coated from water or an organic solvent or an emulsion.

In the present invention, when the organic silver salt-containing layer is formed by coating using a coating solution in which 30% by mass or more of the solvent is water and drying, the binder of the organic silver salt-containing layer is further added. It improves when it is soluble or dispersible in an aqueous solvent (aqueous solvent), especially when it consists of a polymer latex having an equilibrium water content of 2% by mass or less at 25 ° C. and 60% relative humidity. The most preferred form is prepared so that the ionic conductivity is 2.5 mS / cm or less. As such a preparation method, a method of purifying using a separation functional membrane after polymer synthesis can be mentioned. The aqueous solvent in which the polymer is soluble or dispersible is water or a mixture of water and 70% by mass or less of a water-miscible organic solvent. Examples of the water-miscible organic solvent include alcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol; cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; ethyl acetate; and dimethylformamide.

[0142] The term "aqueous solvent" is also used herein in the case where the polymer is not thermodynamically dissolved but exists in a so-called dispersed state. The `` equilibrium water content at 25 ° C relative humidity of 60% '' refers to the mass W1 of the polymer that is in humidity control equilibrium under an atmosphere of 25 ° C and a relative humidity of 60%, and the mass W0 of the polymer that is in a completely dry state at 25 ° C. Can be expressed as follows. Equilibrium moisture content at 25 ° C and 60% relative humidity = [(W1-W0) / W0] x 10
0 (% by mass) The definition and measurement method of the water content can be referred to, for example, Polymer Engineering Course 14, Polymer Material Testing Method (edited by the Society of Polymer Science, Jinjinshokan). The equilibrium water content at 25 ° C. and 60% relative humidity of the binder polymer used in the present invention is preferably 2% by mass or less, more preferably 0.01% by mass.
It is desirably at least 1.5 mass% and more preferably at least 0.02 mass% and at most 1 mass%.

In the present invention, a polymer dispersible in an aqueous solvent is particularly preferred. Examples of the dispersed state include a latex in which fine particles of a water-insoluble hydrophobic polymer are dispersed, and a dispersed state in which polymer molecules are dispersed in a molecular state or in the form of micelles. The average particle size of the dispersed particles is 1 to 50,000 nm, more preferably 5 to 1000 nm
The range of the degree is preferable. The particle size distribution of the dispersed particles is not particularly limited, and may have a wide particle size distribution or a monodispersed particle size distribution. In the present invention, preferred embodiments of the polymer dispersible in an aqueous solvent include acrylic polymers, poly (esters), and rubbers (eg, SBR
Resins), poly (urethane) s, poly (vinyl chloride) s,
Hydrophobic polymers such as poly (vinyl acetate) s, poly (vinylidene chloride) s and poly (olefins) can be preferably used. These polymers may be a linear polymer, a branched polymer, a crosslinked polymer, a so-called homopolymer in which a single monomer is polymerized, or a copolymer in which two or more monomers are polymerized. In the case of a copolymer, it may be a random copolymer or a block copolymer. These polymers have a number average molecular weight of from 5,000 to 100,000, preferably from 10,000 to 200,000. If the molecular weight is too small, the mechanical strength of the emulsion layer is insufficient, and if it is too large, the film-forming properties are poor, which is not preferable.

Specific examples of preferable polymer latex include the following. In the following, the raw material monomers are used, and the numerical value in parentheses is mass%, and the molecular weight is the number average molecular weight. P-1; -MMA (70) -EA (27) -MAA (3)-latex (molecular weight 3700
0) Latex of P-2; -MMA (70) -2EHA (20) -St (5) -AA (5)-(molecular weight 40000) P-3; -St (50) -Bu (47) -MAA ( 3)-latex (molecular weight 4500
0) P-4; -St (68) -Bu (29) -AA (3)-latex (MW 60000) P-5; -St (71) -Bu (26) -AA (3)-latex (Molecular weight 60000) Latex of P-6; -St (70) -Bu (27) -IA (3)-(molecular weight 12000
0) Latex of P-7; -St (75) -Bu (24) -AA (1)-(molecular weight 10800
0) P-8; -St (60) -Bu (35) -DVB (3) -MAA (2)-latex (molecular weight 150,000) P-9; -St (70) -Bu (25) -DVB ( 2) -AA (3)-latex (molecular weight 280000) P-10; -VC (50) -MMA (20) -EA (20) -AN (5) -AA (5)-latex (molecular weight 80000) P-11; -VDC (85) -MMA (5) -EA (5) -MAA (5)-latex (molecular weight 67,000) P-12; -Et (90) -MAA (10)-latex (molecular weight) 12000) Latex of P-13; -St (70) -2EHA (27) -AA (3) (molecular weight 130
000) Abbreviations of the above structures represent the following monomers. MMA; methyl methacrylate, EA; ethyl acrylate, MAA; methacrylic acid, 2EHA; 2-ethylhexyl acrylate, S
t; styrene, Bu; butadiene, AA; acrylic acid, DVB;
Divinylbenzene, VC; vinyl chloride, AN; acrylonitrile, VDC; vinylidene chloride, Et; ethylene, IA; itaconic acid.

The polymer latexes described above are also commercially available, and the following polymers can be used. Examples of acrylic polymers include Sebian A-4635,4658
3,4601 (all manufactured by Daicel Chemical Industries, Ltd.), Nipol Lx811, 8
Examples of poly (esters) such as 14, 821, 820, 857 (all manufactured by Nippon Zeon Co., Ltd.) include FINETEX ES650, 611, 67
5, 850 (all manufactured by Dainippon Ink and Chemicals, Inc.), WD-size, WMS
(Eastman Chemical) and poly (urethane)
Examples of rubbers include HYDRAN AP10, 20, 30, 40 (all manufactured by Dainippon Ink and Chemicals, Inc.), and examples of rubbers include LACSTAR
7310K, 3307B, 4700H, 7132C (hereinafter Dainippon Ink and Chemicals, Inc.)
Nipol Lx416, 410, 438C, 2507 (Nippon Zeon Co., Ltd.)
Examples of poly (vinyl chloride) s such as G35
Examples of poly (vinylidene chloride) s such as 1, G576 (all manufactured by Zeon Corporation) include L502 and L513 (all manufactured by Asahi Kasei Corporation)
Examples of poly (olefins) include Chemipearl S120 and SA100 (all manufactured by Mitsui Petrochemical Co., Ltd.). These polymer latexes may be used alone or as a blend of two or more as necessary.

The polymer latex used in the present invention is particularly preferably a styrene-butadiene copolymer latex. The mass ratio of the styrene monomer unit to the butadiene monomer unit in the styrene-butadiene copolymer is preferably from 40:60 to 95: 5. Also,
The proportion of the styrene monomer unit and the butadiene monomer unit in the copolymer is preferably 60 to 99% by mass. The preferred molecular weight range is the same as described above. Examples of the styrene-butadiene copolymer latex that is preferably used in the present invention include the above-mentioned P-3 to P-8, commercially available products such as LACSTAR-3307B, 7132C, and Nipol Lx416. The latex used in the present invention preferably has a glass transition temperature (Tg) in the range of 10C to 80C, more preferably 20C to 60C. Tg
When two or more types of latexes different from each other are blended and used, the weight average Tg is preferably in the above range.

The organic silver salt-containing layer of the photothermographic material of the present invention may optionally contain a hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose and carboxymethylcellulose. The amount of these hydrophilic polymers to be added is 30% by mass or less of the total binder of the organic silver salt-containing layer, more preferably
It is preferably at most 20% by mass. The organic silver salt-containing layer (that is, the image forming layer) is preferably formed using a polymer latex. The amount of the binder in the organic silver salt-containing layer is
The mass ratio of total binder / organic silver salt is 1/1 to 10/1, and even 1
The range of / 5 to 4/1 is preferred.

Further, such an organic silver salt-containing layer is usually a photosensitive layer (emulsion layer) containing a photosensitive silver halide, which is a photosensitive silver salt. The mass ratio of silver / silver halide is preferably in the range of 400 to 5, more preferably 200 to 10. The total amount of the binder in the image forming layer is preferably in the range of 0.2 to 30 g / m ² , more preferably 1 to 15 g / m ² . A crosslinking agent for crosslinking and a surfactant for improving coating properties may be added to the image forming layer.

The solvent of the coating solution for the organic silver salt-containing layer of the photothermographic material of the present invention (for the sake of simplicity, the solvent and the dispersion medium are collectively referred to as a solvent) is an aqueous solvent containing 30% by mass or more of water. Is preferred. As a component other than water, any water-miscible organic solvent such as methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, and ethyl acetate may be used. The water content of the solvent in the coating liquid is preferably 50% by mass or more, more preferably 70% by mass or more. Examples of preferred solvent composition include water, water / methyl alcohol = 90/10, water /
Methyl alcohol = 70/30, water / methyl alcohol / dimethylformamide = 80/15/5, water / methyl alcohol / ethyl cellosolve = 85/10/5, water / methyl alcohol / isopropyl alcohol = 85/10/5, etc. Yes (numerical values are mass%).

The antifoggants, stabilizers and stabilizer precursors which can be used in the present invention are described in JP-A-10-628.
No. 99, paragraph 0070, EP-A-0 080 364 A
Japanese Patent Publication No. 1, page 20, line 57 to page 21, line 7 include patents. The antifoggants preferably used in the present invention are organic halides, and examples thereof include those disclosed in the patents described in paragraphs 0111 to 0112 of JP-A-11-65021. Particularly, an organic halogen compound represented by the formula (P) in Japanese Patent Application No. 11-87297 and an organic polyhalogen compound represented by the general formula (II) in JP-A-10-339934 are preferred.

Hereinafter, preferred organic polyhalogen compounds in the present invention will be specifically described. The preferred polyhalogen compound in the present invention is a compound represented by the following general formula (IIIa). Formula ^{(IIIa): Q a - (} Y a) na -C (Z 1a) (Z 2a) X b general formula (IIIa), Q ^a represents an alkyl group, an aryl group or a heterocyclic group, Y ^a Represents a divalent linking group, na represents 0 or 1, Z ^1a and Z ^2a represent a halogen atom, and ^Xb represents a hydrogen atom or an electron-withdrawing group. In the general formula (IIIa), Q ^a preferably represents a phenyl group substituted by an electron-withdrawing group having a positive Hammett σp. Specifically, cyano group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, sulfoxide group, acyl group, heterocyclic group, halogen atom, halogenated alkyl group, phosphoryl And the like. The σp value is preferably 0.2 to
In the range of 2.0, more preferably in the range of 0.4 to 1.0. Particularly preferred as the electron-withdrawing group are a carbamoyl group, an alkoxycarbonyl group, an alkylsulfonyl group, and an alkylphosphoryl group, among which a carbamoyl group is most preferred. Hereinafter, specific examples of the compound of the general formula (IIIa) that can be used in the present invention will be shown.

[0152]

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[0153]

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[0154]

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In the present invention, as a method for incorporating an antifoggant into a light-sensitive material, the method described in the above-mentioned method for containing a reducing agent can be mentioned, and it is preferable to add an organic polyhalogen compound as a solid fine particle dispersion. .

As other antifoggants, JP-A-11-6
Mercury (II) salt of paragraph No. 0113 of 5021 publication, benzoic acids of paragraph No. 0114 of the same publication, formula of Japanese Patent Application No. 11-87297.
A salicylic acid derivative represented by (Z), a formalin scavenger compound represented by the formula (S) in Japanese Patent Application No. 11-23995, a triazine compound according to claim 9 in JP-A-11-352624, Compounds represented by the general formula (III) of JP-A-61-11791, 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene and the like can be mentioned.

The photothermographic material of the present invention may contain an azolium salt for the purpose of preventing fog. As the azolium salt, the general formula (XI) described in JP-A-59-193447
A compound described in JP-B-55-12581, and a compound represented by formula (II) described in JP-A-60-153039. The azolium salt may be added to any part of the light-sensitive material. However, it is preferable to add the azolium salt to the layer having the photosensitive layer, and it is more preferable to add the azolium salt to the organic silver salt-containing layer. The azolium salt may be added at any time during the preparation of the coating solution, and when the azolium salt is added to the organic silver salt-containing layer, any process from the preparation of the organic silver salt to the preparation of the coating solution may be performed. To just before application. The azolium salt may be added by any method such as powder, solution, and fine particle dispersion. Further, it may be added as a solution mixed with other additives such as a sensitizing dye, a reducing agent and a color tone agent. In the present invention, the addition amount of the azolium salt may be any amount, but is preferably 1 × 10 ⁻⁶ mol or more and 2 mol or less, more preferably 1 × 10 ⁻³ mol or more and 0.5 mol or less per 1 mol of silver.

In the present invention, a mercapto compound, a disulfide compound, and a thione compound are contained in order to suppress or accelerate development to control development, to improve spectral sensitization efficiency, to improve storage stability before and after development, and the like. Paragraph Nos. 0067 to 006 of JP-A-10-62899
9, compounds represented by the general formula (I) of JP-A-10-186572 and paragraphs 0033 to 0052 as specific examples thereof, pages 20 to 36 to 56 of EP-A-0 080 364 A1.
And Japanese Patent Application No. 11-273670. Among them, mercapto-substituted heteroaromatic compounds are preferred.

In the photothermographic material of the present invention, it is preferable to add a toning agent. For the toning agent, see paragraphs 0054 to 0055 of JP-A-10-62899 and page 23 of EP-A-0 080 684 A1. ~ 48 lines, JP-A-2000-3563
No. 1, especially phthalazinones (phthalazinone, phthalazinone derivatives or metal salts; for example, 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethoxyphthalazinone and 2,3 -Dihydro-
1,4-phthalazinedion); phthalazinones and phthalic acids
(Eg, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride); phthalazines (phthalazine, phthalazine derivative or metal salt; for example, 4- (1-naphthyl) phthalazine, 6-isopropyl Phthalazine, 6-t-butylfuratazine, 6-chlorophthalazine, 5,7-dimethoxyphthalazine and 2,3-dihydrophthalazine); a combination of phthalazines and phthalic acids is preferred, especially phthalazines and phthalates Combinations of acids are preferred.

The plasticizers and lubricants that can be used in the photosensitive layer of the photothermographic material of the present invention are described in
No. 0117 of JP-65021 JP, paragraph No. 0118 of paragraph No. 0136 to 019 of JP-A No. 11-223898, with respect to the super-high contrast agent for super-high contrast image formation and the addition method and amount thereof.
3, formula (H), formulas (1) to (3), formula in Japanese Patent Application No. 11-87297
Compounds of (A) and (B), compounds of general formulas (III) to (V) described in Japanese Patent Application No. 11-91652 (specific compounds:
24), about the contrast enhancement agent, paragraph No. 0102 of JP-A-11-65021, paragraph No. 019 of JP-A-11-223898
4-0195. In order to use formic acid or formate as a strong fogging substance, it is preferable to contain 5 mmol or less, more preferably 1 mmol or less, per mole of silver on the side having the image forming layer containing photosensitive silver halide.

When a super-high contrast agent is used in the photothermographic material of the present invention, it is preferable to use an acid formed by hydration of diphosphorus pentoxide or a salt thereof in combination. Acids or salts thereof formed by hydration of diphosphorus pentoxide include metaphosphoric acid (salt), pyrophosphoric acid (salt), orthophosphoric acid (salt), triphosphoric acid (salt), tetraphosphoric acid (salt), hexametaline Acid (salt)
And the like. Particularly preferred acids or salts thereof formed by hydration of diphosphorus pentoxide include,
Orthophosphoric acid (salt) and hexametaphosphoric acid (salt) can be mentioned. Specific salts include sodium orthophosphate, sodium dihydrogen orthophosphate, sodium hexametaphosphate, and ammonium hexametaphosphate. Use amount of the oxidizing acid or salt thereof formed by hydration of diphosphorus (coating amount per photographic material 1 m ²⁾ may be a desired amount depending on the performance such as sensitivity and fog, but, 0.1～500M
g / m ² is preferred, and 0.5 to 100 mg / m ² is more preferred.

The photothermographic material of the present invention may be provided with a surface protective layer for the purpose of preventing adhesion of the image forming layer.
The surface protective layer may be a single layer or a plurality of layers.
The surface protective layer is described in JP-A-11-65021, paragraphs 0119 to 0120. Gelatin is preferred as the binder for the surface protective layer, but polyvinyl alcohol (PVA) is also preferred. As gelatin, inert gelatin (for example, Nitta Gelatin 750), phthalated gelatin (for example, Nitta Gelatin 801) and the like can be used. As PVA, fully saponified PVA-
105, partially saponified PVA-205, PVA-33
5. MP-203 of modified polyvinyl alcohol (above,
(Trade name, manufactured by Kuraray Co., Ltd.). The coating amount (per 1 m ² of polyvinyl alcohol) of the protective layer (per layer) is preferably 0.3 to 4.0 g / m ^{2, and} 0.3 to 4.0 g / m ^2.
2.0 g / m ² is more preferred.

In particular, when the photothermographic material of the present invention is used for printing applications in which dimensional change is a problem, it is preferable to use a polymer latex for the surface protective layer and the back layer.
For such polymer latex, see "Synthetic Resin Emulsion (edited by Hira Okuda and Hiroshi Inagaki, published by Kobunshi Kanko (1978))" and "Application of Synthetic Latex (Takaaki Sugimura, Yasuo Kataoka, Soichi Suzuki, Keiji Kasahara, Keiji Kasahara) Molecular publishing society (1993)), "Synthesis of Synthetic Latex (Souichi Muroi, published by Kobunshi Kankokai (1970))", and specifically, methyl methacrylate (33.5% by mass)
/ Ethyl acrylate (50% by weight) / methacrylic acid (16.5% by weight) copolymer latex, methyl methacrylate (4
7.5 mass%) / butadiene (47.5 mass%) / itaconic acid (5 mass
%) Copolymer latex, ethyl acrylate / methacrylic acid copolymer latex, methyl methacrylate (58.9% by mass) / 2-ethylhexyl acrylate (2
5.4% by mass) / styrene (8.6% by mass) / 2-hydroxyethyl methacrylate (5.1% by mass) / latex of acrylic acid (2.0% by mass) copolymer, methyl methacrylate (64.0% by mass) / styrene (9.0% by mass) / butyl Acrylate (20.0
Mass%) / 2-hydroxyethyl methacrylate (5.0 mass%
%) / Acrylic acid (2.0% by mass) copolymer latex. Further, as a binder for the surface protective layer, a combination of a polymer latex of Japanese Patent Application No. 11-6872, paragraphs 0021 to 0 of Japanese Patent Application No. 11-143058.
025, paragraph number 00 of Japanese Patent Application No. 11-6872
The technology described in paragraphs 0023 to 0041 of JP-A-2000-19678 may be applied. The ratio of the polymer latex in the surface protective layer is preferably from 10% by mass to 90% by mass of all the binders, particularly preferably from 20% by mass to 80% by mass. The total amount of the binder (including the water-soluble polymer and latex polymer) applied to the surface protective layer (per layer) (per 1 m ^{2 of the} support)
0.3 to 5.0 g / m ² is preferred, and 0.3 to 2.0 g / m ² is more preferred.

The preparation temperature of the coating solution for the image forming layer is 30 ° C. or higher and 65 ° C.
° C or lower, more preferably 35 ° C or higher and lower than 60 ° C, and more preferably 35 ° C or higher and 55 ° C or lower. The temperature of the coating solution for the image forming layer immediately after the addition of the polymer latex is preferably maintained at 30 ° C. or more and 65 ° C. or less.
Preferably, the reducing agent and the organic silver salt are mixed before the addition of the polymer latex.

In the invention, the image forming layer is composed of one or more layers on a support. When it is composed of one layer, it is composed of an organic silver salt, a photosensitive silver halide, a reducing agent and a binder, and if necessary, contains additional materials such as a toning agent, a coating auxiliary and other auxiliary agents as required. When comprising two or more layers, the first image-forming layer (usually a layer adjacent to the support) contains an organic silver salt and a photosensitive silver halide, and some are contained in the second image-forming layer or both layers. Other components must be included. The construction of a multicolor photothermographic material may include a combination of these two layers for each color, and may include all components in a single layer as described in U.S. Pat.No. 4,708,928. You may go out.
In the case of a multi-dye multi-color photosensitive heat-developable photographic material, each emulsion layer is
Generally, they are kept separate from each other by using a functional or non-functional barrier layer between each photosensitive layer, as described in US Pat. No. 4,460,681.

In the photosensitive layer, various dyes and pigments (for example, CI Pigment Blue 60, CI Pigment Blue) can be used from the viewpoint of color tone improvement, prevention of interference fringe generation during laser exposure, and prevention of irradiation.
Blue 64, CI Pigment Blue 15: 6) can be used. These are described in detail in International Publication WO98 / 36322, JP-A-10-268465, JP-A-11-338098 and the like.

In the photothermographic material of the present invention, an antihalation layer can be provided on the side farther from the light source than the photosensitive layer. A photothermographic material generally has a non-photosensitive layer in addition to a photosensitive layer. The non-photosensitive layer may be arranged as follows: (1) a protective layer provided on the photosensitive layer (on the side farther than the support); (2) between a plurality of photosensitive layers or between the photosensitive layer and the protective layer. (3) an undercoat layer provided between the photosensitive layer and the support, and (4) a back layer provided on the opposite side of the photosensitive layer. The filter layer is provided on the photosensitive material as the layer (1) or (2). The antihalation layer is provided on the photosensitive material as the layer (3) or (4).

The antihalation layer is disclosed in
-65021, paragraph numbers 0123 to 0124, JP-A-11-223898
No. 9-230531, No. 10-36695, No. 10-1
Nos. 04779, 11-231457, 11-352625, and 11-352626. The antihalation layer contains an antihalation dye having absorption at the exposure wavelength. When the exposure wavelength is in the infrared region, an infrared absorbing dye may be used, and in that case, a dye having no absorption in the visible region is preferable. When using a dye having absorption in the visible region to prevent halation, it is preferable that substantially no color of the dye remains after image formation, and a means for decoloring by the heat of heat development is used. It is particularly preferable to add a thermal decoloring dye and a base precursor to the non-photosensitive layer to function as an antihalation layer. These techniques are described in JP-A-11-231457 and the like.

The amount of the decolorizable dye to be added is determined depending on the use of the dye. Generally, the optical density (absorbance) measured at the target wavelength is used in an amount exceeding 0.1. The optical density is preferably from 0.2 to 2. The amount of the dye used to obtain such an optical density is generally 0.001-1 g.
/ M ² .

When the dye is decolored in this manner, the optical density after thermal development can be reduced to 0.1 or less. Two or more decolorizable dyes may be used in combination in a heat-decolorable recording material or a photothermographic material. Similarly, two or more base precursors may be used in combination. In thermal decoloring using such a decoloring dye and a base precursor,
When used in combination with a base precursor as described in JP-A-11-352626, a substance (for example, diphenylsulfone, 4-chlorophenyl (phenyl) sulfone) which lowers the melting point by 3 ° C. (deg.) Or more can be used in combination with heat discoloration. It is preferable from the point of view.

In the present invention, a colorant having an absorption maximum at 300 to 450 nm can be added for the purpose of improving the silver tone and the temporal change of the image. Such colorants are disclosed in JP-A-62-210458, JP-A-63-104046, and JP-A-63-103235.
JP-A-63-208846, JP-A-63-306436, JP-A-63
-314535 JP, JP-A-01-61745, Japanese Patent Application No. 11-2767
No. 51, etc. Such a coloring agent is usually added in the range of 0.1 mg / m ^{2 to 1} g / m ² , and the layer to be added is preferably a back layer provided on the side opposite to the photosensitive layer.

The photothermographic material of the present invention is a so-called single-sided photosensitive material having at least one photosensitive layer containing a silver halide emulsion on one side of a support and a back layer on the other side. Preferably, there is. In the present invention, it is preferable to add a matting agent for improving transportability, and the matting agent is described in paragraph No. 01 of JP-A-11-65021.
26-0127. The matting agent is preferably 1 to 400 mg / m ² , when the coating amount is shown per 1 m ² of the photosensitive material,
More preferably, it is 5 to 300 mg / m ² .

The matting degree of the emulsion surface may be any value as long as no star dust failure occurs, but the Bekk smoothness is 30 seconds or more.
The time is preferably 2000 seconds or less, and particularly preferably 40 seconds or more and 1500 seconds or less. Beck smoothness is based on Japanese Industrial Standards (JIS) P8119
"Smoothness test method for paper and paperboard using Beck tester"
And it can be easily obtained by TAPPI standard method T479. In the present invention, the matting degree of the back layer is preferably Beck smoothness of 10 seconds or more of 1200 seconds or less, and 800 seconds or less of 20 seconds or less.
The time is preferably not less than seconds, more preferably not more than 500 seconds and not less than 40 seconds.

In the present invention, the matting agent is preferably contained in the outermost surface layer of the light-sensitive material, a layer functioning as the outermost surface layer, or a layer close to the outer surface. It is preferable to be contained. The back layer applicable to the present invention is described in paragraphs 0128 to 0130 of JP-A-11-65021.

The photothermographic material of the present invention preferably has a film surface pH before heat development of 6.0 or less, more preferably 5.5 or less. The lower limit is not particularly limited, but is about 3. For adjusting the film surface pH, it is preferable to use an organic acid such as a phthalic acid derivative, a nonvolatile acid such as sulfuric acid, or a volatile base such as ammonia from the viewpoint of reducing the film surface pH. In particular, ammonia is preferable for achieving a low film surface pH since ammonia is easily volatilized and can be removed before the application step and the heat development. The method for measuring the film surface pH is described in paragraph No. 0123 of Japanese Patent Application No. 11-87297.

A hardener may be used for each layer such as the photosensitive layer, the protective layer and the back layer of the photothermographic material of the present invention. Examples of hardeners include “THE THEORY OF THE PHOTO” by THJames.
GRAPHIC PROCESS FOURTH EDITION "(Macmillan Publishi
ng Co., Inc., 1977), pages 77 to 87, each of which includes chromium alum, 2,4-dichloro-6-hydroxy-s-triazine sodium salt, N, N-ethylenebis ( Vinyl sulfone acetamide), N, N-propylene bis (vinyl sulfone acetamide), polyvalent metal ions described on page 78 of the same book, and polyisocyanates such as U.S. Pat. No. 4,281,060 and JP-A-6-208193. Epoxy compounds such as described in U.S. Pat. No. 4,791,042, and vinylsulfone compounds such as described in JP-A-62-89048 are preferably used. The hardener is added as a solution, and the time of adding this solution to the protective layer coating solution is from 180 minutes before to just before application, preferably from 60 minutes to 10 seconds before application. Is not particularly limited as long as the effects of the present invention are sufficiently exhibited. As a specific mixing method, a method of mixing in a tank in which the average residence time calculated from the addition flow rate and the amount of liquid sent to the coater is a desired time, N. Harnby, MFEdwards, AWN
ienow, translated by Koji Takahashi, "Liquid Mixing Technology" (published by Nikkan Kogyo Shimbun, 1989).

For the surfactant applicable to the present invention, paragraph No. 0132 of JP-A-11-65021, for the solvent, paragraph 0133 of the same publication, and for the support, paragraph 0134 of the same publication, antistatic For the conductive layer, refer to paragraph No. 0135 of the same publication, for the method of obtaining a color image, refer to paragraph 0136 of the same publication, and for the slipping agent, refer to JP-A-11-845.
No. 73, paragraphs 0061 to 0064 and Japanese Patent Application No. 11-106881 are described in paragraphs 0049 to 0062.

The transparent support is a polyester which has been subjected to a heat treatment at a temperature in the range of 130 to 185 ° C. in order to alleviate the internal strain remaining in the film at the time of biaxial stretching and to eliminate the heat shrinkage distortion generated during the heat development processing. Particularly, polyethylene terephthalate is preferably used. In the case of a photothermographic material for medical use, the transparent support is made of a blue dye (for example,
It may be colored with dye-1) described in Examples of JP-A-240877, or may be uncolored. For the support, JP-A-11-845
Application of undercoating technology such as water-soluble polyester of No. 74, styrene butadiene copolymer of No. 10-186565, and vinylidene chloride copolymer of paragraphs 0063 to 0080 of Japanese Patent Application No. 11-106881. Is preferred. Also, JP-A-56-143430 discloses an antistatic layer or undercoat,
JP 56-143431, JP 58-62646, JP 56-120519, paragraphs 0040 to 0051 of JP-A-11-84573, U.S. Pat.No. 5,575,957, JP-A-11-223898 The techniques described in Paragraph Nos. 0078 to 0084 can be applied.

The photothermographic material is preferably of a monosheet type (a type capable of forming an image on the photothermographic material without using another sheet such as an image receiving material). The photothermographic material may further contain an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber or a coating aid.
Various additives are added to either the photosensitive layer or the non-photosensitive layer. Regarding them, WO98 / 36322, EP803764A1, JP-A-10-186567, and JP-A-10-186567.
Reference can be made to 18568 publication.

The photothermographic material of the present invention may be applied by any method. Specifically, various coating operations are used, including extrusion coating, slide coating, curtain coating, dip coating, knife coating, flow coating, or extrusion coating using a hopper of the type described in U.S. Pat.No. 2,681,294. Stephen F. Kistl
er, "Liquid Film Coating" by Peter M. Schweizer (CH
Extrusion coating or slide coating described on pages 399 to 536, published by APMAN & HALL, 1997) is preferably used, and particularly preferably slide coating is used. An example of the shape of the slide coater used for slide coating is shown in Figure 11 on page 427 of the same book.
It is in b.1. If desired, two or more layers can be coated simultaneously by the method described on pages 399 to 536 of the same book, US Pat. No. 2,761,791 and British Patent No. 837,095.

The coating solution for the organic silver salt-containing layer in the present invention comprises:
It is preferably a so-called thixotropic fluid. The thixotropic property refers to a property in which the viscosity decreases as the shear rate increases. Any device may be used for the viscosity measurement, but it is manufactured by Rheometrics Far East Co., Ltd.
RFS fluid spectrometers are preferably used,
Measured at 25 ° C. Here, the viscosity of the organic silver salt-containing layer coating solution of the present invention at a shear rate of 0.1 S ^-1 is 400 mPas
It is preferably at least 100,000 mPas or less, more preferably
It is 500 mPa · s or more and 20,000 mPa · s or less. Further, at a shear rate of 1000 S ^−1, it is preferably from 1 mPa · s to 200 mPa · s, more preferably from 5 mPa · s to 80 mPa · s.

Various systems expressing thixotropy are known, and are described in “Lecture / Rheology” edited by Polymer Publishing Association, Muroi,
It is described in Morino co-authored "Polymer Latex" (published by the Society of Polymer Publishing). In order for a fluid to exhibit thixotropic properties, it is necessary to contain a large amount of solid fine particles.
In order to enhance the thixotropic property, it is effective to include a thickened linear polymer, to increase the aspect ratio of the contained solid fine particles in an anisotropic shape, to use an alkali thickener, and to use a surfactant.

The techniques that can be used for the photothermographic material of the present invention include EP803764A1, EP883022A1, WO98 / 36322, JP-A-56-62648 and JP-A-58-62644. JP-A-9-281637, 9-29
No. 7367, No. 9-304869, No. 9-311405, No.
No. 9-329865, No. 10-10669, No. 10-62899, No. 10-69023, No. 10-186568, No. 10-9082
No. 3, No. 10-171063, No. 10-186565, No. 1
No. 0-186567, 10-186569 to 10-186572,
No. 10-197974, No. 10-197982, No. 10-197983
No. 10-197985 to No. 10-197987, No. 10-207
No. 001, No. 10-207004, No. 10-221807,
No. 10-282601, No. 10-288823, No. 10-288824
No. 10-307365, No. 10-312038, No. 10
-339934, 11-11100, 11-15105,
No. 11-24200, No. 11-24201, No. 11-30832, No. 11-84574, No. 11-65021, No. 11-10954
No. 7, No. 11-125880, No. 11-129629, No. 1
No. 1-133536 to No. 11-133539, No. 11-133542,
JP 11-133543, JP 11-223898, JP 11-352627
Publications.

The photothermographic material of the present invention may be developed by any method, but is usually developed by elevating the temperature of the photothermographic material exposed imagewise. The preferred development temperature is 80 to 250 ° C, more preferably 100 to 140 ° C.
° C. The development time is preferably from 1 to 180 seconds, from 10 to 180 seconds.
90 seconds is more preferable, and 10 to 40 seconds is particularly preferable.

As a method of thermal development, a plate heater method is preferable. The method described in JP-A-11-133572 is preferred as the heat development method using a plate heater method,
A heat developing apparatus for obtaining a visible image by contacting a photothermographic material having a latent image formed thereon with a heating unit in a heat development unit, wherein the heating unit comprises a plate heater, and one of the plate heaters A thermal developing apparatus, wherein a plurality of pressing rollers are disposed to face each other along a surface, and heat development is performed by passing the photothermographic material between the pressing roller and the plate heater. It is preferable to divide the plate heater into two to six stages and lower the temperature at the tip part by about 1 to 10 ° C. Such a method is disclosed in JP-A-54-300.
As described in No. 32, water and organic solvents contained in the photothermographic material can be excluded from the system. Changes in the shape of the support of the material can also be suppressed.

The light-sensitive material of the present invention may be exposed by any method, but a laser beam is preferred as an exposure light source.
As the laser beam according to the present invention, a gas laser (Ar ⁺ ,
He-Ne), a YAG laser, a dye laser, a semiconductor laser and the like are preferable. Further, a semiconductor laser and a second harmonic generation element can be used. Preferably, it is a gas or semiconductor laser emitting red to infrared light.

As a medical laser imager having an exposure section and a heat development section, there is a Fuji Medical Dry Laser Imager FM-DPL.
Regarding FM-DPL, Fuji Medical Review No.
8, pages 39 to 55, and it goes without saying that those techniques are applied as a laser imager for the photothermographic material of the present invention. It can also be applied as a photothermographic material for laser imagers in the "AD network" proposed by Fuji Medical System as a network system conforming to the DICOM standard.

The photothermographic material of the present invention forms a black-and-white image by a silver image, and is used for medical diagnosis, photothermographic material for industrial photography, photothermographic material for printing, COM
It is preferably used as a photothermographic material for use.
Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

[0189]

EXAMPLES Example 1 (Preparation of PET support) Terephthalic acid and ethylene glycol
Of intrinsic viscosity IV = 0.66 (measured in phenol / tetrachloroethane = 6/4 (mass ratio) at 25 ° C.)
I got After pelletizing this, dried at 130 ° C for 4 hours,
After being melted at 300 ° C., the film was extruded from a T-die and rapidly cooled to prepare an unstretched film having a thickness of 175 · after heat setting. This was longitudinally stretched 3.3 times using rolls having different peripheral speeds, and then laterally stretched 4.5 times using a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively. Then, after heat setting at 240 ° C for 20 seconds,
% Eased. Then, after slitting the chuck part of the tenter, knurling is performed on both ends and wound at 4 kg / cm ² ,
A roll with a thickness of 175 μm was obtained.

(Surface Corona Treatment) Using a solid state corona treatment machine 6KVA model manufactured by Pillar Co., both surfaces of the support were treated at room temperature at 20 m / min. From the current and voltage readings at this time, it was found that the support was treated at 0.375 kV · A · min / m ² . At this time, the processing frequency was 9.6 kHz, and the gap clearance between the electrode and the dielectric roll was 1.6 mm.

(Preparation of Undercoat Support) (1) Preparation of Coating Solution for Undercoat Layer Formulation (for undercoat layer on photosensitive layer side) Pesresin A-515GB manufactured by Takamatsu Oil Co., Ltd. (30% by mass solution) 234 g Polyethylene glycol monononyl Phenyl ether (average ethylene oxide number = 8.5) 10% by mass solution 21.5g Soken Chemical Co., Ltd. MP-1000 (polymer fine particles, average particle size 0.4μm) 0.91g distilled water 744ml

Formulation (for back surface first layer) Styrene-butadiene copolymer latex 158 g (solid content 40% by mass, styrene / butadiene mass ratio = 68/32) 2,4-dichloro-6-hydroxy-S-triazine Sodium salt 8% by weight aqueous solution 20g 1% by weight aqueous solution of sodium laurylbenzenesulfonate 10ml Distilled water 854ml

Formulation (for back surface side second layer) SnO ₂ / SbO (9/1 mass ratio, average particle size 0.038 μm, 17 mass% dispersion) 84 g gelatin (10 mass% aqueous solution) 89.2 g Shin-Etsu Chemical Co., Ltd. ) Metrolose TC-5 (2 mass% aqueous solution) 8.6 g Soken Chemical Co., Ltd. MP-1000 0.01 g 1 mass% aqueous solution of sodium dodecylbenzenesulfonate 10 ml NaOH (1 mass%) 6 ml Proxel (manufactured by ICI) 1 ml 805 ml of distilled water

(Preparation of Undercoating Support) Thickness 175 μm
After performing the above-mentioned corona discharge treatment on both surfaces of the biaxially stretched polyethylene terephthalate support, the undercoating solution formulation was applied on one surface (photosensitive layer surface) with a wire bar at a wet application amount of 6.6 ml / m ² (per surface). ) And dried at 180 ° C. for 5 minutes. Then, the above-mentioned undercoating coating liquid formulation was applied to the back surface (back surface) with a wire bar so that the wet application amount was 5.7 ml / m ² , and 180 At 5 ° C. for 5 minutes, and then apply the above-mentioned undercoating solution formulation to the back surface (back surface) with a wire bar so that the wet coating amount is 7.7 ml / m ^2, and then dry at 180 ° C. for 6 minutes to prepare an undercoating support. It was created.

(Preparation of Back Surface Coating Solution) (Preparation of Solid Precursor Dispersion (a) of Base Precursor) 64 g of base precursor compound 11 and 2 g of diphenyl sulfone were used.
8 g and 10 g of surfactant Demol N manufactured by Kao Corporation were mixed with 220 ml of distilled water, and the mixture was dispersed in beads using a sand mill (1/4 Gallon Sand Grinder Mill, manufactured by Imex Co., Ltd.) to have an average particle diameter of 0.2. As a result, a solid fine particle dispersion (a) of a base precursor compound having a thickness of μm was obtained.

(Preparation of Dye Solid Fine Particle Dispersion) 9.6 g of cyanine dye compound 13 and 5.8 g of sodium P-dodecylbenzenesulfonate were mixed with 305 ml of distilled water, and the mixture was subjected to a sand mill (1/4 Gallon sand grinder mill, The beads were dispersed using an IMEX Co., Ltd.
A dispersion of solid dye fine particles of 2 μm was obtained.

(Preparation of antihalation layer coating solution) Gelatin 17g, polyacrylamide 9.6g, solid fine particle dispersion (a) of the above base precursor (a) 70g, dye solid fine particle dispersion 56g, polymethyl methacrylate fine particles (average particle size 6.5) μm), 1.5 g of benzoisothiazolinone, 2.2 g of sodium polyethylenesulfonate, 0.2 g of the blue dye compound 14, 3.9 g of the yellow dye compound 15 and 844 ml of water were mixed to prepare an antihalation layer coating solution.

(Preparation of back surface protective layer coating solution)
At 50 ° C, gelatin 50 g, polystyrene sodium sulfonate 0.2 g, N, N-ethylenebis (vinylsulfone acetamide) 2.4 g, sodium t-octylphenoxyethoxyethanesulfonic acid 1 g, benzoisothiazolinone 30
mg, N-perfluorooctylsulfonyl-N-propylalanine potassium salt 37 mg, polyethylene glycol mono (N-perfluorooctylsulfonyl-N-propyl-2-aminoethyl) ether [average degree of polymerization of ethylene oxide 1
5] 0.15 g, C ₈ F ₁₇ SO ₃ K 32 mg, C ₈ F ₁₇ SO ₂ N (C ₃ H ₇ ) (CH ₂ CH ₂ O) ₄
(CH ₂ ) ₄ -SO ₃ Na 64 mg, acrylic acid / ethyl acrylate copolymer (copolymerization mass ratio 5/95) 8.8 g, aerosol OT
(American Cyanamid Co.) 0.6 g, liquid paraffin emulsion 1.8 g as liquid paraffin, and 950 ml of water were mixed to obtain a back surface protective layer coating solution.

(Preparation of Silver Halide Emulsion 1) Distilled water 1421
Add 3.1 ml of a 1% by weight potassium bromide solution to the
ol / L concentration of sulfuric acid 3.5 ml, while stirring the liquid to which phthalated gelatin 31.7 g was added in a titanium-coated stainless steel reaction vessel, keeping the liquid temperature at 34 ° C., and adding distilled water to 22.22 g of silver nitrate and adding 95.4% Solution A diluted to 15.3 g, potassium bromide 15.3 g, and potassium iodide 0.8 g were diluted with distilled water to a volume of 97.4 ml, and solution B was added at a constant flow rate over 45 seconds. afterwards,
10 ml of a 3.5% by mass aqueous hydrogen peroxide solution was added, and further 10.8 ml of a 10% by mass aqueous solution of benzimidazole was added.
Furthermore, distilled water was added to 51.86 g of silver nitrate to dilute the solution C to 317.5 ml, potassium bromide 44.2 g and potassium iodide 2.2 g.
Was diluted with distilled water to a volume of 400 ml, solution C was added at a constant flow rate over 20 minutes, and solution D added pAg to 8.1.
, And added by a controlled double jet method. The total amount of potassium hexachloride iridate (III) was added 10 minutes after starting to add the solution C and the solution D so as to be 1 × 10 ⁻⁴ mol per mol of silver. Five seconds after the completion of the addition of the solution C, an aqueous solution of potassium hexairon cyanide (II) was added in a total amount of 3 × 10 ^-4 mol per mol of silver. The pH was adjusted to 3.8 using sulfuric acid having a concentration of 0.5 mol / L, stirring was stopped, and a precipitation / desalting / water washing step was performed. The pH was adjusted to 5.9 with 1 mol / L sodium hydroxide to prepare a silver halide dispersion having a pAg of 8.0.

While stirring the above silver halide dispersion, 38
C. and 0.34% by weight of 1,2-benzisothiazoline
5 ml of a methanol solution of -3-one was added, and after 40 minutes, a methanol solution of the spectral sensitizing dye SS-1 was added at 1 × 10 ⁻³ per mol of silver.
After 1 minute, the temperature was raised to 47 ° C. 20 minutes after the temperature rise, sodium benzenethiosulfonate
7.6 × 10 ^-5 mol per mol was added, and after 5 minutes, tellurium sensitizer B was added with a methanol solution at 1.9 × 10 ^-4 per mol of silver.
Mol was added and the mixture was aged for 91 minutes. 1.3 ml of a 0.8% by mass methanol solution of N, N'-dihydroxy-N "-diethylmelamine was added, and after 4 minutes, 5-methyl-2-mercaptobenzimidazole was added with a methanol solution at 3.7 × 10 ⁻ per mol of silver. ³ mol and 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole in a methanol solution at 4.9 × 1 per mol of silver
By adding 0 to ³ mol, a silver halide emulsion 1 was prepared. The grains in the prepared silver halide emulsion had an average equivalent circle diameter of 4
3.5% uniform iodine with 2 nm, 20% variation coefficient of circle equivalent diameter
It was silver iodobromide grains containing mol%. Particle size etc.
It was determined from the average of 1000 particles using an electron microscope. The [100] plane ratio of these particles was determined to be 80% using the Kubelka-Munk method.

(Silver halide emulsions 2, 2b, 2c, 2
d) Preparation of 3 to 20) In the preparation of silver halide emulsion 1, the type of spectral sensitizing dye was changed from SS-1 as shown in Table 1, and the liquid temperature during grain formation was changed as shown in Table 1. The silver halide emulsions 2, 2b, Preparations 2c, 2d, 3-20 were made.

(Preparation of Coating Emulsion A for Coating Solution) For silver halide emulsions 1, 2, 2b, 2c, 2d, and 3 to 20, silver benzothiazolium iodide was dissolved in a 1% by weight aqueous solution of silver 1 emulsion.
7 × 10 ^-3 mol was added per mol.

(Preparation of fatty acid silver dispersion) 87.6 kg of behenic acid (product name: Edenor C22-85R) manufactured by Henkel, 423 L of distilled water,
49.2 L of a 5 mol / L NaOH aqueous solution and 120 L of tert-butanol were mixed and reacted by stirring at 75 ° C. for 1 hour to obtain a sodium behenate solution. Separately, 206.2 L of an aqueous solution of 40.4 kg of silver nitrate
(PH 4.0) was prepared and kept at 10 ° C. The reaction vessel containing 635 L of distilled water and 30 L of tert-butanol was kept at 30 ° C., and while stirring, the entire amount of the sodium behenate solution and the entire amount of the silver nitrate aqueous solution were kept at a constant flow rate of 62 minutes and 10 seconds, respectively.
Added over 60 minutes. At this time, only the aqueous silver nitrate solution was added for 7 minutes and 20 seconds after the start of the aqueous silver nitrate solution addition, and then the addition of the sodium behenate solution was started. After the addition of the aqueous silver nitrate solution was completed, only the sodium behenate solution was added for 9 minutes and 30 seconds. Was added. At this time, the temperature in the reaction vessel was 30 ° C., and the external temperature was controlled so that the liquid temperature was constant. Further, the piping of the addition system of the sodium behenate solution was kept warm by steam tracing, and the steam opening was adjusted so that the liquid temperature at the outlet at the tip of the addition nozzle became 75 ° C. Also, the piping for the addition system of the silver nitrate aqueous solution is
The temperature was maintained by circulating cold water outside the double tube.
The addition position of the sodium behenate solution and the addition position of the aqueous silver nitrate solution were arranged symmetrically with respect to the stirring axis, and were adjusted to a height such that they did not come into contact with the reaction solution.

After the addition of the sodium behenate solution was completed, the mixture was left to stir at the same temperature for 20 minutes, and the temperature was lowered to 25 ° C. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtered water became 30 μS / cm. Thus, a fatty acid silver salt was obtained. The obtained solid content was stored as a wet cake without drying. When the morphology of the obtained silver behenate particles was evaluated by electron micrographing, a = 0.
14 μm, b = 0.4 μm, c = 0.6 μm, average aspect ratio 5.2, average sphere equivalent diameter 0.52 μm, and flake-like crystal with a sphere equivalent diameter variation coefficient of 15%. (A, b, c are prescribed in the text) Dry solid content 1
To a wet cake equivalent to 00 g, 7.4 g of polyvinyl alcohol (trade name: PVA-217) and water were added to adjust the total amount to 385 g, and the mixture was preliminarily dispersed by a homomixer. Next, the pre-dispersed stock solution was dispersed in a dispersing machine (trade name: Microfluidizer M-110S-EH, manufactured by Microfluidics International Corporation, G10
Pressure of 1750kg /
Adjusted to cm ² and processed three times to obtain a silver behenate dispersion. The cooling operation was set at a dispersion temperature of 18 ° C. by installing coiled heat exchangers before and after the interaction chamber, respectively, and adjusting the temperature of the refrigerant.

(Preparation of a 25% by mass dispersion of a reducing agent) 10 kg of 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane and modified polyvinyl alcohol (Kuraray
10% of a 20% by weight aqueous solution of Poval MP203 manufactured by
6 kg was added and mixed well to form a slurry. This slurry is sent by a diaphragm pump and has an average diameter of 0.5 mm.
Horizontal sand mill filled with zirconia beads (UVM-
2: 3 hours and 30 minutes by using IMEX Co., Ltd., and after adding 0.2 g of benzoisothiazolinone sodium salt and water, the concentration of the reducing agent was adjusted to 25% by mass, and the reducing agent dispersion was obtained. I got The reducing agent particles contained in the thus obtained reducing agent dispersion had a median diameter of 0.42 μm and a maximum particle diameter of 2.0 μm or less. The resulting reducing agent dispersion was filtered through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust, and stored.

(Preparation of 25% by mass dispersion of reducing agent complex)
2-methylenebis- (4-ethyl-6-tert-butylphenol)
10 kg of a 1: 1 complex of phenol and triphenylphosphine oxide and denatured polyvinyl alcohol (manufactured by Kuraray Co., Ltd., Poval MP
To 10 kg of the 20% by mass aqueous solution of 203), 16 kg of water was added and mixed well to form a slurry. This slurry was sent by a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 3 hours and 30 minutes, and then benzoisothiazolinone sodium salt 0.2 g and water were added to adjust the concentration of the reducing agent to 25% by mass to obtain a reducing agent complex dispersion. The reducing agent complex particles contained in the thus obtained reducing agent complex dispersion had a median diameter of 0.46 μm and a maximum particle diameter of 2.0 μm or less. The obtained reducing agent complex dispersion was filtered through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust, and stored.

(Preparation of a 10% by mass dispersion of a mercapto compound) 5 kg of 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole and modified polyvinyl alcohol (Kuraray)
8.3k of water to 5kg of 20% by weight aqueous solution of Poval MP203 manufactured by
g was added and mixed well to form a slurry. This slurry was sent by a diaphragm pump and filled with zirconia beads having an average diameter of 0.5 mm in a horizontal sand mill (UVM-2:
After dispersing for 6 hours using IMEX Co., Ltd., water was added to adjust the concentration of the mercapto compound to 10% by mass to obtain a mercapto dispersion. The mercapto compound particles contained in the thus obtained mercapto compound dispersion had a median diameter of 0.40 μm and a maximum particle diameter of 2.0 μm or less. The resulting mercapto compound dispersion was filtered through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust, and stored. Immediately before use, the mixture was filtered again with a polypropylene filter having a pore size of 10 μm.

(Preparation of 20% by mass dispersion of organic polyhalogen compound-1) 5 kg of tribromomethylnaphthyl sulfone
And modified polyvinyl alcohol (Poval MP manufactured by Kuraray Co., Ltd.)
203) 2.5 kg of a 20% by mass aqueous solution of sodium triisopropylnaphthalenesulfonate and 213 g of a 20% by mass aqueous solution of sodium triisopropylnaphthalenesulfonate;
10 kg of water was added and mixed well to form a slurry. This slurry is sent by a diaphragm pump and has an average diameter of 0.5 m.
m zirconia beads filled horizontal sand mill (UVM-
2: manufactured by Imex Co., Ltd.) for 5 hours, and then added with 0.2 g of benzoisothiazolinone sodium salt and water to adjust the concentration of the organic polyhalogen compound to 20% by mass. A dispersion was obtained. The organic polyhalogen compound particles contained in the polyhalogen compound dispersion thus obtained have a median diameter of 0.36 μm and a maximum particle diameter of 2.0 μm.
m or less. The obtained organic polyhalogen compound dispersion was filtered with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

(Preparation of 25% by mass dispersion of organic polyhalogen compound-2) Same as 20% by mass dispersion of organic polyhalogen compound-1, except that 5 kg of tribromomethylnaphthyl sulfone was used instead of tribromomethyl ( Using 5 kg of 4- (2,4,6-trimethylphenylsulfonyl) phenyl) sulfone, the mixture was dispersed, diluted so that the organic polyhalogen compound became 25% by mass, and filtered. The organic polyhalogen compound particles contained in the organic polyhalogen compound dispersion thus obtained had a median diameter of 0.38 μm and a maximum particle diameter of 2.0 μm or less. The obtained organic polyhalogen compound dispersion was filtered with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

(Preparation of 26% by mass dispersion of organic polyhalogen compound-3) Same as 20% by mass dispersion of organic polyhalogen compound-1, except that 5 kg of tribromomethylnaphthyl sulfone was used instead of tribromomethylphenyl Sulfone 5
Using 20 kg of a 20% by mass aqueous solution of MP203, 5 kg was added, dispersed, diluted so that the organic polyhalogen compound became 26% by mass, and filtered. The organic polyhalogen compound particles contained in the organic polyhalogen compound dispersion thus obtained had a median diameter of 0.41 μm and a maximum particle diameter of 2.0 μm or less. The obtained organic polyhalogen compound dispersion was filtered with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored. After storage, it was stored at 10 ° C or less until use.

<< Preparation of 25% by mass dispersion of organic polyhalogen compound-4 >> Similar to 20% by mass dispersion of organic polyhalogen compound-1, except that 5 kg of tribromomethylnaphthyl sulfone was used instead of tribromomethyl-naphthyl sulfone. Disperse using 5 kg of 3-pentanoylaminophenylsulfone, dilute the organic polyhalogen compound to 25% by mass,
Filtration was performed. The organic polyhalogen compound particles contained in the organic polyhalogen compound dispersion thus obtained had a median diameter of 0.41 μm and a maximum particle diameter of 2.0 μm or less. The obtained organic polyhalogen compound dispersion was filtered with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

(Preparation of 5% by mass solution of phthalazine compound) 8 kg of modified polyvinyl alcohol MP2 manufactured by Kuraray Co., Ltd.
03 in 174.57 kg of water, and then 3.15 kg of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate.
14.28 kg of a 70% by mass aqueous solution of 6-isopropylphthalazine was added to prepare a 5% by mass solution of 6-isopropylphthalazine.

(Preparation of 20% by mass dispersion of pigment)
t 64 g of Blue 60 and 6.4 g of Demol N manufactured by Kao Corporation in 250 g of water
Was added and mixed well to form a slurry. Average diameter 0.5mm
Of zirconia beads was placed in a vessel together with the slurry, and dispersed by a dispersing machine (1 / 4G sand grinder mill: manufactured by Imex Co., Ltd.) for 25 hours to obtain a pigment dispersion. The pigment particles contained in the pigment dispersion thus obtained had an average particle size of 0.21 ·.

(Preparation of 40% by mass of SBR latex) Ultrafiltration
(UF) The purified SBR latex was obtained as follows. The following SBR latex was diluted 10 times with distilled water and diluted with UF-purification module FS03-FC-FUY03A1 (Daisen Membrane System Co., Ltd.) until the ionic conductivity became 1.5 mS / cm. Purify and use Sandet-BL manufactured by Sanyo Chemical Co., Ltd.
It was added to be 0.22% by mass. Further with NaOH and NH ₄ OH Na ⁺ ion: NH ₄ ⁺ ion = 1: was added to a 2.3 (molar ratio) was adjusted to pH 8.4. The latex concentration at this time was 40% by mass. (SBR latex: -St (68) -Bu (29) -AA (3)-latex, Tg = 17 ° C) Average particle size 0.1 μm, concentration 45 mass%, equilibrium water content 0.6 at 25 ° C and 60% relative humidity Mass%, ion conductivity 4.2 mS / cm (Ion conductivity was measured using a conductivity meter CM-30S manufactured by Toa Denpa Kogyo Co., Ltd., and a latex stock solution (40 mass%) was measured at 25 ° C.), pH 8. Two

(Preparation of Coating Solution for Emulsion Layer (Photosensitive Layer)) 1.1 g of a 20% by mass dispersion of the pigment obtained above and a fatty acid silver dispersion 10
3 g, 20 of polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.)
5 g of an aqueous solution of 5% by mass, 25 g of a 25% dispersion of a reducing agent, 25 g of an organic polyhalogen compound dispersion-1, -2, -3 at a ratio of 5: 1: 3 (mass ratio) of 16.3 g, 10 mass% of a mercapto compound 6.2 g of dispersion, ultrafiltration (UF) purified and pH adjusted SBR latex (Tg: 17
C) 40% by mass of 106 g, 5% by mass solution of phthalazine compound 1
8 ml was added, and immediately before coating, 10 g of silver halide mixed emulsion A was added.
The emulsion layer coating solution, which had been well mixed, was fed as it was to a coating die at 70 ml / m ² and coated. The viscosity of the above emulsion layer coating solution was measured with a B-type viscometer of Tokyo Keiki Co., Ltd.
It was 85 [mPa · s] at ° C (No. 1 rotor, 60 rpm). The viscosity of the coating solution at 25 ° C. using an RFS Fluid Spectrometer manufactured by Rheometrics Far East Co., Ltd. was 1,500, 220, 70, 40, at a shear rate of 0.1, 1, 10, 100, and 1000 [1 / sec], respectively. It was 20 [mPa · s].

(Preparation of Emulsion Surface Intermediate Layer Coating Solution) A 10% by weight aqueous solution 772 of polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.)
g, 20% by weight dispersion of pigment 5.3 g, methyl methacrylate /
Styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer mass ratio 64/9/20/5 /
2) 2 ml of a latex 27.5 mass% solution, 2 ml of a 5 mass% aqueous solution of aerosol OT (manufactured by American Cyanamid Co.), 10.5 ml of a 20 mass% aqueous solution of diammonium phthalate, total amount
Add water to 880 g and NaOH to pH 7.5
And adjusted to 10 ml / m ² to the coating die. The viscosity of the coating solution is a B-type viscometer4
At 0 ° C. (No. 1 rotor, 60 rpm), the value was 21 [mPa · s].

(Preparation of Coating Solution for First Layer of Emulsion Surface Protecting Layer) 64 g of inert gelatin was dissolved in water, and methyl methacrylate was dissolved.
/ Styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer mass ratio 64/9/20
/ 5/2) 80 g of latex 27.5 mass% liquid, 23 ml of 10 mass% methanol solution of phthalic acid, 10 mass% of 4-methylphthalic acid
23 ml of aqueous solution, 28 ml of 0.5 mol / L sulfuric acid, aerosol
5m 5% aqueous solution of OT (American Cyanamid)
l, 0.5 g of phenoxyethanol and 0.1 g of benzoisothiazolinone were added to make a coating solution by adding water to a total amount of 750 g. / m ² to the coating die. The viscosity of the coating solution was 17 mPa · s using a B-type viscometer at 40 ° C. (No. 1 rotor, 60 rpm).

(Preparation of Coating Solution for Emulsion Surface Protective Layer Second Layer) Inert gelatin (80 g) was dissolved in water, and methyl methacrylate was dissolved in water.
/ Styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer mass ratio 64/9/20
/ 5/2) 102 g of latex 27.5% by mass liquid, 5% of N-perfluorooctylsulfonyl-N-propylalanine potassium salt
3.2 ml of a 2% by mass solution of polyethylene glycol mono (N-perfluorooctylsulfonyl-N-propyl-2-aminoethyl) ether [average degree of polymerization of ethylene oxide = 15] is 32 ml, and Aerosol OT (American 23 ml of a 5% by mass solution of Ianamid Co., Ltd., 4 g of polymethyl methacrylate fine particles (average particle size 0.7 μm), 21 g of polymethyl methacrylate fine particles (average particle size 6.4 μm), 1.6 g of 4-methylphthalic acid, 4.8 g of phthalic acid, Water was added to a total of 650 g to 44 ml of 0.5 mol / L sulfuric acid and 10 mg of benzoisothiazolinone. 8.3m
The solution was sent to the coating die so as to be l / m ² . The viscosity of the coating solution was 9 mPa with a B-type viscometer at 40 ° C (No. 1 rotor, 60 rpm).
[S].

(Preparation of Photothermographic Material) On the back surface side of the undercoat support, a coating solution for the antihalation layer was applied so that the coating amount of the solid fine particle dye was 0.04 g / m ² and the back surface was protected. The layer coating solution was simultaneously layer-coated so that the coated amount of gelatin was 1.7 g / m ^2, and dried to form a back layer. Emulsion layer (silver halide coated silver amount 0.14 g / m ² ), intermediate layer, first protective layer,
The protective layer second layer was simultaneously coated in the order of the slide bead coating method in the order of the second layer, and a sample of the photothermographic material (N shown in Table 1)
o. 1, 2, 2b, 2c, 2d, 3 to 20). The coating and drying conditions are as follows. The coating was performed at a speed of 160 m / min, the gap between the coating die tip and the support was set to 0.10 to 0.30 mm, and the pressure in the decompression chamber was set to be 196 to 882 Pa lower than the atmospheric pressure. The support was neutralized with ion wind before coating. Dry-bulb temperature in subsequent chilling zone
After cooling the coating liquid with a wind of 10 to 20 ° C, it is transported in a non-contact type, and a dry bulb temperature of 23 to 45 is provided by a helix type non-contact drying device.
It dried with the dry wind of 15 degreeC, and a wet bulb temperature of 15-21 degreeC. After drying,
After humidity control at 25 ° C and relative humidity of 40-60%, the film surface is 70-90 ° C.
Was heated to become. After heating, the film surface was cooled to 25 ° C. The matte degree of the produced photothermographic material was 550 seconds on the photosensitive layer side and 130 seconds on the back side in Bekk smoothness.
Further, the pH of the film surface on the photosensitive layer surface side was measured and found to be 6.0.

(Evaluation) (Evaluation of photographic performance) Exposure and thermal development (approximately 120) ° C), the obtained image was evaluated by a densitometer, and Dmin (fog) and Dmax were measured. The sensitivity was determined from the reciprocal of the ratio of the exposure amount giving a density higher than Dmin by 1.0, and expressed as a relative value with the photothermographic material 1 being 100.

(Evaluation of Dependence on System Environment) The Fuji Medical Dry Laser Imager FM-DPL was installed in a constant temperature and humidity room, and was subjected to 70% relative humidity at 32 ° C., 10% relative humidity at 32 ° C., and 70% relative humidity at 13 ° C. , 13 ° C relative humidity 25
The photographic material was exposed and thermally developed under the four conditions of%, and the obtained image was evaluated with a densitometer. The density actually obtained for a certain exposure amount giving a density of around 1.0 was measured, and the difference between the maximum value and the minimum value among the output densities under the four conditions was compared. The results of the above evaluations are summarized in Table 1 below.

[0222]

Embedded image

[0223]

Embedded image

[0224]

Embedded image

[0225]

[Table 1]

From the light-sensitive materials Nos. 1 to 18 in Table 1, the sensitizing dye of the general formula (I) used in the present invention has higher sensitivity, less fog and higher density than the comparative dye. It turns out that it is excellent in storage stability. Among the sensitizing dyes used in the present invention, a comparison between a dye having no aromatic ring and a dye having an aromatic ring ((60) and (63b), (63c))
(63d), (63), (62) or (61); or (15) and (17) or (16); or (10
3) and (105)), it can be seen that the dye having an aromatic ring is superior. Further, from Nos. 1 and 4 and 19 and 20, it can be seen that the average equivalent circle diameter of the silver halide emulsion used in the present invention is more preferably 42 nm than 80 nm.

As described above, in the present invention, it has been found that a sensitizing dye having a specific structure is specifically excellent. It was also found that the effect was particularly remarkable when the average equivalent circle diameter of the halogenated emulsion was 10 to 50 nm.

Example 2 The same comparison as in Example 1 was made as follows. JP 200
In the system of the photothermographic material of Example 5 of JP-A-122206, evaluation was performed in exactly the same manner except that SS-3, (16) of Example 1 of the present invention was used instead of Comparative Dye A. . As a result, when SS-3 was used, sensitivity = 1.
00 (based on reference), Dmin = 0.14, sensitivity after aging = 90, and Dmin = 0.18, (16)
, Sensitivity = 152, Dmin = 0.1
0, sensitivity after aging = 150 and Dmin = 0.11 were found to be excellent.

Example 3 Preparation of Photothermographic Material-2 The photothermographic material No. 2 described in Example 1 was prepared. The photothermographic material-2 was prepared in the same manner as in No. 3 except that the emulsion layer coating solution was changed as follows. When evaluated in the same manner as in Example 1,
Similar effects were confirmed.

<< Preparation of Emulsion Layer (Photosensitive Layer) Coating Solution >> 1.1 g of a 20% by mass dispersion of the pigment obtained above, and a fatty acid silver dispersion 10
3 g, 20 of polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.)
5 g of a 25% by mass aqueous solution of the above reducing agent complex 26
g, organic polyhalogen compound dispersion-3, -4, 1: 3 (mass ratio), total amount 8.2 g, mercapto compound 10 mass% dispersion 6.2
g, ultrafiltration (UF) purified and pH adjusted SBR latex (Tg:
(23 ° C.) 106 g of 40% by mass and 18 ml of a 5% by mass solution of a phthalazine compound were added.
The emulsion layer coating solution in which 0 g was well mixed was directly sent to a coating die at 70 ml / m ² and coated.

[0231]

According to the present invention, it has become possible to provide a photothermographic material having high storability which can provide high sensitivity, low fog and high density.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomoyuki Ozeki 210 Nakanuma, Minamiashigara, Kanagawa Prefecture Inside Fuji Photo Film Co., Ltd. In-house F-term (reference) 2H123 AB00 AB03 AB06 AB18 AB23 AB28 BB00 BB23 CB00 CB03

Claims (5)

[Claims] 1. A photothermographic material comprising at least one photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one side of a support, A photothermographic material comprising a compound of the following general formula (I): Embedded image (Wherein, dye ¹ represents a dye; M ¹ represents a charge-balancing counter ion; m ¹ represents a number required to neutralize the charge of a molecule; q represents an integer of 1 or more; R ¹ Is R represented by
^1a , R ^1b , R ^1c or R ^1d . Embedded image ^{Wherein, R a, R b, R} c, and R ^d each independently represent an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, heterocyclyloxy group, or an amino group, Q ^a, Q ^b , Q ^c and Q ^d represent a linking group. r, s,
t and u are 0 or 1. ) 2. The compound of the general formula (I), wherein at least one of Q ^a and R ^a , at least one of Q ^b and R ^b , at least one of Q ^c and R ^c , Q ^d and 2. The photothermographic material according to claim 1, wherein at least one of R ^d is a group containing an aromatic ring. 3. A compound of the formula (I) wherein R ^a ,
The photothermographic material according to claim 1, wherein ^Rb , ^Rc , and ^Rd are represented by the following formulas. Embedded image (In the formula, La represents ^a linking group. H is 0 or 1. A ¹
Represents an aromatic group. ) 4. Dye¹Are represented by the following general formulas (X) and (X)
Claims selected from I) or (XII)
Item 4. The photothermographic material according to any one of Items 1 to 3. Embedded image(In the formula (X), L¹¹, L¹², L¹³, L¹⁴, L^Fifteen,
L¹⁶, And L¹⁷Each independently represents a methine group. p¹¹as well as
p¹²Each independently represents 0 or 1. n¹¹Is 0, 1,
Represents 2, 3 or 4. Z¹¹And Z¹²Are independently nitrogen-containing
A group of atoms necessary to form an elementary heterocyclic ring.
The ring may be fused. M¹Represents a charge-balancing counterion
Represents, m¹Represents the number required to neutralize the molecular charge.
You. R¹¹And R¹²Are each independently an alkyl group, an aryl
Represents a group or a heterocyclic group. Where L¹¹, L¹², L¹³, L
¹⁴, L^Fifteen, L¹⁶, L¹⁷, Z¹¹, Z¹², R¹¹And R ¹²To
Is at least one R¹The group represented by
You. )(In the formula (XI), L¹⁸, L¹⁹, L²⁰, And L^{twenty one}Are each
Independently represents a methine group. p¹³Represents 0 or 1. q¹¹Is
Represents 0 or 1. n¹²Represents 0, 1, 2, 3 or 4
You. Z¹³Is a group of atoms necessary to form a nitrogen-containing heterocycle
Represents Z¹⁴And Z¹⁴′ Are each independently (N—R¹⁴) Q¹¹When
Together form a heterocyclic or acyclic acidic end group
Represents the group of atoms necessary for Where Z¹³, And Z
¹⁴And Z¹⁴'May have a condensed ring. M¹Is the charge balance
Represents a counter ion, m¹Is required to neutralize the molecular charge
Represents a number. R¹³Is an alkyl group, an aryl group, or a hetero group
Represents a ring group. R¹⁴Is hydrogen atom, alkyl group, aryl
Represents a group or a heterocyclic group. Where L¹⁸, L¹⁹, L²⁰,
L^{twenty one}, Z¹³, Z¹⁴, Z¹⁴’, R¹³And R¹⁴Has less
And one R¹Is substituted. )(In the formula (XII), L^{twenty two}, L^{twenty three}, L^{twenty four}, L^{twenty five}, L²⁶,
L²⁷, L²⁸, L²⁹, And L³⁰Each independently represent a methine group
You. p¹⁴And p^FifteenEach independently represents 0 or 1. q¹²Is
Represents 0 or 1. n¹³And n¹⁴Are independently 0, 1,
Represents 2, 3 or 4. Z^FifteenAnd Z¹⁷Are independently nitrogen-containing
Represents an atom group necessary for forming a heterocyclic ring. Z¹⁶When
Z¹⁶′ Are each independently (N—R¹⁶) Q¹²Together with
Represents the group of atoms necessary to form a ring. However,
Z^Fifteen, Z¹⁶And Z¹⁶’And Z¹⁷May be fused
No. M¹Represents a charge-balancing counter ion, m¹Is the charge of the molecule
Indicates the number required for neutralization. R^Fifteen, And R¹⁷Is German
Stands for an alkyl group, an aryl group, or a heterocyclic group.
R¹⁶Is a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic ring
Represents a group. Where L^{twenty two}, L^{twenty three}, L^{twenty four}, L^{twenty five}, L²⁶, L
²⁷, L²⁸, L²⁹, L³⁰, Z^Fifteen, Z ¹⁶, Z¹⁶’, Z¹⁷,
R^Fifteen, R¹⁶Or R¹⁷Has at least one R¹In table
Group is substituted. ) 5. The photothermographic material according to claim 1, wherein the photosensitive silver halide has an average equivalent circle diameter of 10 to 50 nm.