JP2006119621A - Photothermographic material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photothermographic material that has good sharpness and good image storability and provides a preferable image color tone. <P>SOLUTION: The photothermographic material has at least an image-forming layer containing a photosensitive silver halide, a non-photosensitive organic silver salt, a reducer, and a binder on at least one surface of a support, wherein (1) the photothermographic material further contains a dye having a half breadth of 100 nm or less at a maximum absorbance peak, and (2) 50 mass% or more of a binder in an outermost layer on a dye-containing surface, is a polymer latex. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a photothermographic material suitably used in the field of medical diagnostic films, the field of photoengraving films and the like.

  In recent years, in the medical diagnostic film field and the photoengraving film field, it is strongly desired to reduce the amount of processing waste liquid from the viewpoint of environmental protection and space saving. Therefore, heat as a medical diagnostic film and a photoengraving film that can be efficiently exposed by a laser image setter or a laser imager and can form a clear black image with high resolution and sharpness. There is a need for techniques relating to developed image recording materials. According to these heat-developable image recording materials, a heat-development processing system that does not require solution-based processing chemicals and that is simpler and does not impair the environment can be supplied to customers.

  There are similar demands in the field of general image recording materials, but medical diagnostic images in particular require fine depiction, so they require high image quality with excellent sharpness and graininess, and ease of diagnosis. From the viewpoint, a cool black image is preferred. At present, various hard copy systems using pigments and dyes such as inkjet printers and electrophotography are distributed as general image forming systems, but none of them are satisfactory as a medical image output system.

  On the other hand, thermal imaging systems using organic silver salts are disclosed in, for example, U.S. Pat. Nos. 3,152,904 and 3,457,075 and D.C. Klosterboer, “Thermally Processed Silver Systems” (Imaging Processes and Materials), 8th edition, J. Sturge. (Walworth, A. Shepp, Chapter 9, 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 toning agent that controls the color tone of silver. And an image forming layer dispersed in a binder matrix. The photothermographic material is heated to a high temperature (for example, 80 ° C. or higher) after image exposure, and a black silver image is formed by a redox reaction between a reducible silver salt (functioning 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 exposure area.

  Conventionally, this type of photothermographic material is known, but most of these recording materials form an image forming layer by using an organic solvent such as toluene, methyl ethyl ketone, or methanol as a solvent. The use of an organic solvent as a solvent is disadvantageous in terms of cost due not only to the influence on the human body in the manufacturing process but also to other factors such as recovery of the solvent.

  Therefore, a method of forming an image forming layer (hereinafter sometimes referred to as “aqueous image forming layer”) using a coating solution of an aqueous medium without such a concern is disclosed. For example, JP-A-49-52626 and JP-A-53-116144 disclose techniques using gelatin as a binder. Japanese Patent Laid-Open No. 50-151138 discloses a technique using polyvinyl alcohol as a binder.

  However, these techniques have a lot of fogging, and the color tone of the formed image is poor, so that it has not reached a practical level. On the other hand, Japanese Patent Application Laid-Open Nos. 10-10669 and 10-62899 disclose techniques for forming an image forming layer using a polymer latex binder and an aqueous medium.

  In a photographic light-sensitive material, a dye is usually used for the purpose of preventing halation, preventing irradiation, a filter function, or adjusting image color tone. Although there is a similar requirement in the photothermographic material, a unique function not required in the conventional wet development type photosensitive material is required. That is, all the materials necessary for image formation are previously contained in the coating film, and remain in the film as they are or as reaction products even after heat development.

  In general, dyes not only have absorption in the required wavelength range, but also have side absorptions at the wavelengths before and after that. For example, even infrared absorption dyes for infrared exposure have absorption in the visible range and coloring is visually Observed. Therefore, attempts have been made to decolorize the dyes used in the photothermographic material by a chemical reaction by heating during heat development. However, the introduction of the decoloring mechanism has problems such as an increase in film turbidity and an increase in film thickness, and it is difficult to introduce it into the image forming layer and its adjacent layers due to the influence on photographic performance. It was. Furthermore, since the decoloring reaction is slow, it is difficult to quickly decolorize.

On the other hand, attempts have been made to eliminate the decoloring mechanism by using a dye having a sharp absorption spectrum with little side absorption (see, for example, Patent Documents 1 and 2). These dyes are dyes that form aggregates and exhibit a sharp absorption spectrum, and have the feature that they act effectively in a small amount because they have the maximum absorption wavelength effectively in the required wavelength range.
However, since the photothermographic material is used in various environments, there are many demands for dyes, and they have not been sufficiently satisfied. In particular, unexpected problems that have not been recognized in the past have been newly identified for the problem that the dye, which is a special problem of photothermographic materials, remains in the film even after image formation and is stored. Improvement and new problem solving are required.
JP 2003-43628 A JP-A-2003-84395

  An object of the present invention is to provide a photothermographic material having high sharpness, a preferable image color tone, and excellent image storability.

The above problems have been solved by the following means.
<1> A photothermographic material having an image forming layer containing at least a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent and a binder on at least one surface of a support,
1) containing a dye having a full width at half maximum of 100 nm or less,
2) The photothermographic material, wherein 50% by mass or more of the outermost binder on the surface having the dye is a polymer latex.
<2> The photothermographic material according to <1>, wherein the dye is contained in a back layer on the opposite side of the support from the image forming layer.
<3> The photothermographic material according to <1>, wherein the dye is contained in a layer on the same side as the image forming layer of the support.
<4> The photothermographic material according to <3>, wherein the image forming layer contains the dye.
<5> The photothermographic material according to <4>, wherein 50% by mass or more of the binder of the image forming layer is a polymer latex.
<6> The photothermographic material according to any one of <1> to <5>, wherein the dye is a water-soluble dye.
<7> The photothermographic material according to <6>, wherein the water-soluble dye is a metal phthalocyanine dye represented by formula (PC-1):

(Wherein, M is ^{.R 1, R 4, R 5} , R 8, R 9, R 12, R 13, R 16 are each independently a hydrogen atom, a substituent represents a metal atom, R ^1, At least one of R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ¹⁶ is an electron withdrawing group R ² , R ³ , R ⁶ , R ⁷ , R ¹⁰ , R ¹¹ , R ¹⁴ and R ¹⁵ each independently represents a hydrogen atom or a substituent.)
<8> In the general formula (PC-1), at least one of R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ¹⁶ is represented by the general formula (II). The photothermographic material according to <7>, which is a group:

(In the formula, L ¹ is ^** -SO _2- ^* , ^** -SO _3- ^* , ^** -SO ₂ NR _N- ^* , ^** -SO- ^* , ^** -CO- ^* , ^** - _{^{CONR N - *, ** -COO- *}} , ** -COCO- *, ** -COCO 2 - *, or ^** -COCONR _N -. ^{*, **} denotes a bond with a phthalocyanine skeleton at this position representing the , * Indicates bonding with R ¹⁷ at this position, and R _N represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, a sulfonyl group, or a sulfamoyl group. R ¹⁷ represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group.
<9> In the general formula (PC-1), R ² , R ³ , R ⁶ , R ⁷ , R ¹⁰ , R ¹¹ , R ¹⁴ , and R ¹⁵ are hydrogen atoms, and R ¹ , R ⁴ , R ^{5, R 8, R 9,} R 12, R 13, and a photothermographic material according to <8>, wherein the at least one R ¹⁶ is a group represented by the general formula (II).
<10> In the general formula (PC-1), four or more of R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ¹⁶ are the general formula (II). The photothermographic material according to <9>, which is a group represented by
<11> The photothermographic material according to <6>, wherein the water-soluble dye is an associative dye.
<12> The photothermographic material according to <11>, wherein the associative dye is a polymethine dye.
<13> The photothermographic material according to <12>, wherein the polymethine dye is a cyanine dye or an oxonol dye.
<14> The photothermographic material according to any one of <1> to <13>, wherein the outermost polymer latex has a Tg of -20 ° C to 70 ° C.
<15> The photothermographic material according to any one of <1> to <14>, wherein the outermost layer contains a gelling agent.
<16> The photothermographic material according to any one of <3> to <15>, wherein a non-photosensitive intermediate layer is provided between the outermost layer and the image forming layer.
<17> The non-photosensitive intermediate layer includes at least two layers, and at least 50% by mass or more of the binder of the non-photosensitive intermediate layer A adjacent to the image forming layer is represented by the following general formula (M). The photothermographic material according to <16>, which is a polymer latex having a monomer component:
Formula ^{_{(M) CH 2 = CR 01}} -CR 02 = CH 2
(In the formula, R ⁰¹ and R ⁰² are groups selected from a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a halogen atom, and a cyano group).
<18> The photothermographic material according to <17>, wherein R ⁰¹ and R ^{02 in} the general formula (M) are both hydrogen atoms, or one is a hydrogen atom and the other is a methyl group.
<19> In the at least two non-photosensitive intermediate layers, the non-photosensitive intermediate layer B adjacent to the outermost layer is characterized in that 50% by mass or more of the binder is a hydrophilic polymer derived from animal protein. The photothermographic material according to <17> or <18>.
<20> The photothermographic material according to <19>, wherein the hydrophilic protein derived from animal protein is gelatin.

  According to the present invention, a photothermographic material having high sharpness, a preferable image color tone and excellent image storability can be provided.

Hereinafter, the present invention will be described in detail.
The photothermographic material of the present invention is a photothermographic material having an image forming layer containing at least a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent and a binder on at least one surface of a support. In addition, it contains a dye having a half-value width of 100 nm or less at the maximum absorbance, and 50% by mass or more of the binder in the outermost layer on the surface having the dye is a polymer latex.
The half width in the present invention means an absorption width at 1/2 of the maximum absorbance of the absorption spectrum in the visible region to the infrared region.
The layer containing the dye may be a surface-side layer having an image forming layer or a back layer.
Preferably, the dye is a water-soluble dye.
Preferably, the water-soluble dye is a metal phthalocyanine dye represented by the general formula (PC-1).
In addition, since the effect is large, it is preferable to add the layer to which the dye is added to a layer that is not the outermost layer.

In the formula, M represents a metal atom. R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ¹⁶ are each independently a hydrogen atom or a substituent, and R ¹ , R ⁴ , R ⁵ , R ⁸ , R ^At least one of ⁹ , R ¹² , R ¹³ , and R ¹⁶ is an electron withdrawing group. R ² , R ³ , R ⁶ , R ⁷ , R ¹⁰ , R ¹¹ , R ¹⁴ , and R ¹⁵ each independently represent a hydrogen atom or a substituent.
Preferably, in the general formula (PC-1), at least one of R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ¹⁶ is represented by the general formula (II). It is a group.

In the formula, L ¹ is ^** -SO _2- ^* , ^** -SO _3- ^* , ^** -SO ₂ NR _N- ^* , ^** -SO- ^* , ^**- CO- ^* , ^**- CONR. _{^{N - *, ** -COO- *,}} ** -COCO- *, ** -COCO 2 - *, or ^** -COCONR _N - ^*, representing a. ** is bonded to the phthalocyanine skeleton at this position, and * is bonded to R ¹⁷ at this position. _RN represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, a sulfonyl group, or a sulfamoyl group. R ¹⁷ represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group.
More preferably, R ² , R ³ , R ⁶ , R ⁷ , R ¹⁰ , R ¹¹ , R ¹⁴ , and R ¹⁵ are hydrogen atoms, and R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ^At least one of ¹² , R ¹³ , and R ¹⁶ is a group represented by the general formula (II), and most preferably R ² , R ³ , R ⁶ , R ⁷ , R ¹⁰ , R ¹¹ , R ¹⁴ , And R ¹⁵ are all hydrogen atoms, and four or more of R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ¹⁶ are represented by the general formula (II) It is.

Another preferred example of the water-soluble dye is an associative dye. The associative dye is preferably a polymethine dye, and more preferably a cyanine dye or an oxonol dye.
The outermost polymer latex preferably has a Tg of -20 ° C or higher and 70 ° C or lower. Furthermore, it is preferable that the outermost layer contains a gelling agent.

It is preferable to have a non-photosensitive intermediate layer between the outermost layer and the image forming layer, and more preferably, the non-photosensitive intermediate layer is composed of at least two layers and is adjacent to the image forming layer. At least 50 mass% or more of the binder of the intermediate layer A is a polymer latex having a monomer component represented by the general formula (M).
Formula ^{_{(M) CH 2 = CR 01}} -CR 02 = CH 2
In the formula, R ⁰¹ and R ⁰² are a group selected from a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a halogen atom, and a cyano group.

  Further, in the non-photosensitive intermediate layer B adjacent to the outermost layer, 50% by mass or more of the binder is preferably a hydrophilic polymer derived from animal protein, and more preferably gelatin.

  The present inventors faced an unexpected problem when a dye having a half-width at maximum absorbance of 100 nm or less was introduced into a photothermographic material. At the stage of photothermographic material production, it shows a sharp absorption spectrum with a half-width of 100 nm or less, but when measured after heat development, the absorption spectrum changes significantly broadly or the wavelength at which the absorption maximum is completely different It turns out that the problem changes. As a result of diligent analysis by the present inventors, a dye exhibiting such sharp absorption forms a unique aggregate in water, and the absorption by the aggregate is sharp, or the dye structure is flat. As a result of being rich, oriented to various solvents such as water, or oriented on various substrates, it shows sharp absorption, so the aggregates are destroyed or oriented by heating during thermal development, especially heating in the presence of a small amount of water. It has been found that the sharp absorption characteristics are lost when turbulence occurs. As a result of searching for an improvement means based on the above analysis results, it was found that the outermost layer is improved by constituting with a hydrophobic polymer latex, and the present invention has been achieved. Hydrophobic polymer latex is known for photographic use, but its effect on the specific problems of the above-mentioned photothermographic material is completely unexpected.

(Dye whose half-width at maximum absorbance is 100 nm or less)
As the dye having a half-width of 100 nm or less at the maximum absorbance in the present invention, a metal phthalocyanine dye and an aggregate-forming dye are preferable. More preferably, the metal phthalocyanine dye is a dye represented by the general formula (PC-1), Polymerine dyes, particularly cyanine dyes and oxonol dyes are preferred as the coalescence forming dye. The full width at half maximum is preferably 80 nm or less, more preferably 50 nm or less.
The maximum absorption wavelength of the antihalation dye used in the present invention is preferably close to the image exposure wavelength of the photothermographic material of the present invention from the viewpoint of absorption efficiency. Therefore, a range of ± 50 nm with respect to the image exposure wavelength is preferable. More preferably, the range is ± 20 nm, and most preferably ± 10 nm. In addition, since the photothermographic material of the present invention is most effective when image exposure is performed with a red laser, the maximum absorption wavelength of the transmission absorption spectrum is preferably 600 nm to 750 nm, more preferably 600 nm to 720 nm, More preferably, it is 620 nm to 680 nm.
These dyes are described in detail below.

1) Metal phthalocyanine compound A particularly preferable dye is a metal phthalocyanine compound represented by the following general formula (PC-1).

  In the general formula (PC-1), M represents a metal atom. In the case of representing a metal atom, any metal may be used as long as it forms a stable complex. Li, Na, K, Be, Mg, Ca, Ba, Al, Si, Cd, Hg, Cr, Fe, Co Ni, Cu, Zn, Ge, Pd, Cd, Sn, Pt, Pb, Sr, and Mn can be used. Mg, Ca, Co, Zn, Pd, and Cu are preferably used, more preferably Co, Pd, Zn, and Cu are used, and Cu is particularly preferably used.

<Description of substituents, etc.>
In the general formula (PC-1), R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ¹⁶ are each independently a hydrogen atom, a substituent, or an electron withdrawing group. And at least one of R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ¹⁶ is an electron withdrawing group.
The electron withdrawing group here is a halogen atom, a cyano group, a nitro group, -C (= O) -R, -C (= O) -C (= O) -R, -S (= O). -R, -S (= O) _2- R, -C (= NR ')-R, -S (= NR')-R, -S (= NR ') _2- R, -P (= O) R ₂ , —O—R ″, —S—R ″, —N (—R ′) — C (═O) —R, —N (—R ′) — S (═O) —R, — N (-R ')-S (= O) _2- R, -N (-R')-C (= NR-)-R, -N (-R ')-S (= NR') ₂ It is selected from the group represented by —R or —N (—R ′) — P (═O) R ₂ . Here, R is a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an amino group, an alkyloxy group, an aryloxy group, a heterocyclic oxy group, an OH group, an alkylthio group, an arylthio group, a heterocyclic thio group, or an SH group. Represents. R ′ represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an acyl group, a sulfonyl group, a sulfinyl group, or a phosphoryl group. R ″ represents a perfluoroalkyl group, a cyano group, an acyl group, a sulfonyl group, or a sulfinyl group.

  The group represented by R, R ′, and R ″ may be substituted with a substituent. Specific examples of the substituent include a halogen atom (a fluorine atom, a chloro atom, a bromine atom, or an iodine atom), an alkyl group. (Including an aralkyl group, a cycloalkyl group, or an active methine group), an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group (regardless of the position of substitution), a heterocyclic group containing a quaternized nitrogen atom (For example, pyridinio group, imidazolio group, quinolinio group, isoquinolinio group), acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, carboxy group or a salt thereof, sulfonylcarbamoyl group, acylcarbamoyl group, sulfamoylcarbamoyl group, Carbazoyl group, oxalyl group, oxamoyl group, cyano group, thiocarbamoyl , Hydroxy group, alkoxy group (including a group repeatedly containing ethyleneoxy group or propyleneoxy group unit), aryloxy group, heterocyclic oxy group, acyloxy group, (alkoxy or aryloxy) carbonyloxy group, carbamoyloxy group, sulfonyl Oxy group, amino group, (alkyl, aryl, or heterocyclic) amino group, acylamino group, sulfonamide group, ureido group, thioureido group, imide group, (alkoxy or aryloxy) carbonylamino group, sulfamoylamino group, Semicarbazide group, thiosemicarbazide group, hydrazino group, ammonio group, oxamoylamino group, (alkyl or aryl) sulfonylureido group, acylureido group, acylsulfamoylamino group, nitro group, mel group Pto group, (alkyl, aryl, or heterocyclic) thio group, (alkyl or aryl) sulfonyl group, (alkyl or aryl) sulfinyl group, sulfo group or a salt thereof, sulfamoyl group, acylsulfamoyl group, sulfonylsulfamoyl Groups or salts thereof, groups containing phosphoric acid amide or phosphate ester structures, silyloxy groups (eg trimethylsilyloxy, t-butyldimethylsilyloxy), silyl groups (eg trimethylsilyl, t-butyldimethylsilyl, phenyldimethylsilyl) These substituents may be further substituted with these substituents.

  As the electron withdrawing group in the general formula (PC-1), a group represented by the general formula (II) is preferably used.

L ¹ is ^** -SO _2- ^* , ^** -SO _3- ^* , ^** -SO ₂ NR _N- ^* , ^** -SO- ^* , ^** -CO- ^* , ^** -CONR _N- ^{* _{, ** -COO- *, ** -COCO 2}} - *, or ^** -COCONR _N - represents the ^*. ** is bonded to the phthalocyanine skeleton at this position, and * is bonded to R ¹⁷ at this position. _RN represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, a sulfonyl group, or a sulfamoyl group. R _N may be further substituted with a substituent which R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ^{16 in the} general formula (I) can take. L ¹ is preferably _{^{** -SO 2 - *, ** -SO}} 2 NR N - *, ** -CO- *, ** -CONR N - * , or ^** -COO- ^* are used, more preferably the _{^{** -SO 2 - *, ** -SO}} 2 NR N - * , or ^** -CONR _N - ^*, is used, and particularly preferably ^** -SO ₂ - ^*, or ^** -SO ₂ NR _N - ^* Is used.
R _N is preferably a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group, more preferably a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms or a carbon number of 1 to 20 And more preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms or a heterocyclic group having 1 to 10 carbon atoms, particularly preferably a hydrogen atom. Alternatively, an alkyl group having 1 to 6 carbon atoms is used.

R ¹⁷ represents a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group. When R ¹⁷ is an alkyl group, an aryl group, or a heterocyclic group, these are further represented by R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ^{16 in the} general formula (I). It may be substituted with a possible substituent. R ¹⁷ is preferably an alkyl group or an aryl group, and particularly preferably an alkyl group. R ¹⁷ has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms.

R ¹⁷ is preferably substituted with a hydrophilic group. Here, the hydrophilic group means a carboxyl group, a sulfo group, a phosphate group, a group having a quaternary salt structure of nitrogen, a group having a quaternary salt structure of phosphorus, or a polyethyleneoxy group. When the hydrophilic group is a carboxyl group, a sulfo group, or a phosphoric acid group, it may have a counter cation as necessary, and the counter cation is a group having a quaternary salt structure of a metal cation, ammonium ion, or nitrogen. A group having a quaternary salt structure of phosphorus is used.
When W is a group having a quaternary salt structure of nitrogen or a group having a quaternary salt structure of phosphorus, it may have a counter anion as necessary. Examples of the counter anion include halogen ions, sulfate ions, nitric acid Ions, phosphate ions, oxalate ions, alkane sulfonate ions, aryl sulfonate ions, alkane carboxylate ions, aryl carboxylate ions, and the like can be used. The hydrophilic group is preferably a carboxyl group, a sulfo group or a phosphoric acid group, more preferably a carboxyl group or a sulfo group. In this case, Li ⁺ , Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ or NH ₄ ⁺ is preferably used as the counter cation, and more preferably Li ⁺ , Na ⁺ , K ⁺ or NH ₄ ⁺ is used. Particularly preferably, Li ⁺ and Na ⁺ are used.

In the general formula (PC-1), when R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , R ¹⁶ are substituents, R, R ′ in the general formula (I) , R ″ may be a substituent selected from the same group as the substituent which can be taken. These substituents may be further substituted with these substituents.
The substituent is preferably a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group (regardless of the position of substitution), a heterocyclic group containing a quaternized nitrogen atom (for example, pyridinio group, imidazolio) Group, quinolinio group, isoquinolinio group), acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, carboxy group or a salt thereof, sulfonylcarbamoyl group, acylcarbamoyl group, sulfamoylcarbamoyl group, carbazoyl group, oxalyl group, Oxamoyl group, cyano group, thiocarbamoyl group, sulfonyloxy group, imide group, sulfamoylamino group, semicarbazide group, thiosemicarbazide group, nitro group, (alkyl or aryl) sulfonyl group, (alkyl or aryl) sulfur Iniru group, a sulfo group or a salt thereof, sulfamoyl group, sulfonylsulfamoyl group or a salt thereof, a group containing a phosphoric amide or phosphoric ester structure is used. More preferably, an alkyl group, aryl group, heterocyclic group, acyl group, alkoxycarbonyl group, carbamoyl group, carboxy group or a salt thereof, oxalyl group, oxamoyl group, cyano group, imide group, sulfamoylamino group, (alkyl or An aryl) sulfonyl group, an (alkyl or aryl) sulfinyl group, a sulfo group or a salt thereof, a sulfamoyl group, an acylsulfamoyl group, a sulfonylsulfamoyl group or a salt thereof is used.
More preferably, aryl group, heterocyclic group, acyl group, alkoxycarbonyl group, carbamoyl group, carboxy group or a salt thereof, (alkyl or aryl) sulfonyl group, (alkyl or aryl) sulfinyl group, sulfo group or a salt thereof, sulfamoyl group Is used.

In the compound represented by the general formula (I), preferably four or more of R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ¹⁶ are represented by the general formula (II). More preferably, at least one of the combinations of R ¹ and R ⁴ , R ⁵ and R ⁸ , R ⁹ and R ¹² , R ¹³ and R ¹⁶ is represented by the general formula (II) It is. Particularly preferably, among the combinations of R ¹ and R ⁴ , R ⁵ and R ⁸ , R ⁹ and R ¹² , R ¹³ and R ¹⁶ , one is a group represented by the general formula (II) and the other is hydrogen Is an atom. In the case where a plurality of groups represented by the general formula (II) are contained in the same molecule, they may be the same or different.

In the general formula (PC-1), R ² , R ³ , R ⁶ , R ⁷ , R ¹⁰ , R ¹¹ , R ¹⁴ , and R ¹⁵ each independently represent a hydrogen atom or a substituent. The substituents herein are selected from the same range as the substituents that R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ¹⁶ of general formula (I) can take. .
R ² , R ³ , R ⁶ , R ⁷ , R ¹⁰ , R ¹¹ , R ¹⁴ , and R ¹⁵ are preferably a hydrogen atom, a halogen atom, a carboxyl group, an alkoxycarbonyl group, an acyl group, a sulfo group, a sulfamoyl group, A sulfonyl group, an alkyl group, an aryl group, or a heterocyclic group is used. A hydrogen atom, a halogen atom, a sulfo group, a sulfamoyl group, or a sulfonyl group is more preferable, and a hydrogen atom is particularly preferable.

In the present invention, particularly preferred dyes in the general formula (PC-1) are those in which R ² , R ³ , R ⁶ , R ⁷ , R ¹⁰ , R ¹¹ , R ¹⁴ , and R ¹⁵ are hydrogen atoms, and R It is a dye in which at least one of ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ¹⁶ is a group represented by the general formula (II). More preferably, R ² , R ³ , R ⁶ , R ⁷ , R ¹⁰ , R ¹¹ , R ¹⁴ , and R ¹⁵ are hydrogen atoms, and R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ^In the dye, at least four of ¹² , R ¹³ and R ¹⁶ are groups represented by the general formula (II).

In general, a phthalocyanine compound having a plurality of substituents may have positional isomers at different positions to which the substituents are bonded.
The compound represented by the general formula (PC-1) of the present invention is no exception, and in some cases, several kinds of positional isomers can be considered. In the present invention, the phthalocyanine compound may be used as a single compound, but can also be used as a mixture of positional isomers. When used as a mixture of regioisomers, the number of regioisomers mixed, the substitution position of the substituent in each regioisomer, and the mixing ratio of regioisomers may be arbitrary.

<Specific example>
Examples of the compound represented by the general formula (PC-1) used in the present invention are shown below. However, the present invention is not limited to the following examples.
Examples of the compound represented by the general formula (PC-1) used in the present invention are shown below. However, the present invention is not limited to the following examples. In the following compound examples, the regioisomer mixture is described as one compound.

CuCl ₂ (134 mg, 1 mmol) was added to an ethylene glycol solution (10 mL) of synthetic intermediate A (1.26 g, 4 mmol) and heated to 100 ° C. DBU (1.52 g, 10 mmol) was added to the reaction mixture and heated at 100 ° C. for 10 hours. The reaction mixture was acidified with hydrochloric acid and LiCl was added to precipitate a crude product of phthalocyanine. The crude product obtained here was purified by column chromatography using Sephadex (registered trademark) G-15 as a carrier, to obtain 67 mg (yield 5%) of a mixture of Exemplified Compound 2.

2) Aggregate-forming dye The aggregate-forming dye used in the invention is present in an associated state in the photothermographic material. The associated dye forms a so-called J band and shows a sharp absorption spectrum peak. The association of dyes and the J band are described in various documents (for example, Photographic Science and engineering Vol. 18, No. 323-335 (1974)). The absorption maximum of the dye in the J-association state moves to the longer wave side than the absorption maximum of the dye in the solution state (monomer state). Therefore, whether the dye contained in the layer is in an associated state or a non-associated state can be easily determined by measuring the absorption maximum.
The associative dye is preferably a polymethine dye, and more preferably a cyanine dye or an oxonol dye.
As for the associative dye, details of paragraph Nos. 0017 to 0079 of JP-A No. 2003-43628, and Compound Nos. 1 to 82, and paragraphs 0048 to 0112 of JP-A No. 2003-84395, compound Nos. 1-82, and these descriptions and compound examples can be applied to the present invention.

3) Dye usage method <Addition method>
The dye of the present invention is preferably water-soluble, and is preferably used in the production of a photosensitive material as an aqueous solution prepared in advance using water as a medium. In the aqueous solution, the water-soluble phthalocyanine compound of the present invention is contained in an amount of 0.1 to 30% by mass, preferably 0.5 to 20% by mass, more preferably about 1 to 8% by mass. Contained. The aqueous solution may further contain a water-soluble organic solvent and auxiliary additives. The content of the water-soluble organic solvent is 0% by mass to 30% by mass, preferably 5% by mass to 30% by mass, and the auxiliary additive is 0% by mass to 5% by mass, preferably about 0% by mass to 2% by mass. .

  Specific examples of the water-soluble organic solvent that can be used in preparing the aqueous solution of the water-soluble dye of the present invention include C1 such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, and tertiary butanol. C4 alkanol, carboxylic acid amide such as N, N-dimethylformamide or N, N-dimethylacetamide, lactams such as ε-caprolactam, N-methylpyrrolidin-2-one, urea, 1,3-dimethylimidazolidine- Cyclic ureas such as 2-one or 1,3-dimethylhexahydropyrimido-2-one, acetone, methyl ethyl ketone, ketones such as 2-methyl-2-hydroxypentan-4-one, keto alcohols, tetrahydrofuran, dioxane, etc. Ether, ethylene glycol 1,2- or 1,3-propylene glycol, 1,2- or 1,4-butylene glycol, 1,6-hexylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, thiodiglycol, polyethylene glycol, polypropylene Monomers having C2-C6 alkylene units such as glycols, oligomers or polyalkylene glycols or thioglycols, polyols (triols) such as glycerin, hexane-1.2.6-triol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether , Diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl Examples thereof include C1-C4 alkyl ethers of polyhydric alcohols such as ether, γ-butyrolactone and dimethyl sulfoxide. Two or more of these water-soluble organic solvents may be used in combination.

  Of the above water-soluble organic solvents, urea, N-methylpyrrolidin-2-one, mono-, di- or trialkylene glycols having an alkylene unit having 2 to 6 carbon atoms are preferred, and mono-, di- or triethylene glycol, dipropylene are further preferred. Glycol, dimethyl sulfoxide, and the like are preferably used. In particular, use of N-methylpyrrolidin-2-one, diethylene glycol, dimethyl sulfoxide, and urea is preferable, and urea is particularly preferable. The water-soluble dye of the present invention is diluted by further mixing the aqueous solution with various chemicals at the time of preparation of the photosensitive material. Therefore, the water-soluble organic solvent is added to the content of the water-soluble dye separately from the aqueous solution. A method of containing 1 mol to 500 mol with respect to 1 mol is also preferably used.

  As auxiliary additives, for example, antiseptic / antifungal agents, pH adjusters, chelating reagents, rust inhibitors, water-soluble ultraviolet absorbers, water-soluble polymer compounds, dye solubilizers, surfactants and the like are added as necessary. .

  Examples of antiseptic / antifungal agents include sodium dehydroacetate, sodium sorbate, sodium 2-pyridinethiol-1-oxide, sodium benzoate, sodium pentachlorophenol, benzoisothiazolinone and salts thereof, parahydroxybenzoic acid esters, etc. Can be used.

  As the pH adjuster, any substance can be used as long as the pH can be controlled in the range of 4 to 11 without adversely affecting the aqueous solution to be prepared. Examples include alkanolamines such as diethanolamine and triethanolamine, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, ammonium hydroxide, and alkalis such as lithium carbonate, sodium carbonate, and potassium carbonate. Examples thereof include metal carbonates.

  Examples of the chelating reagent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uracil diacetate and the like. Examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonia thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite. Examples of the water-soluble polymer compound include polyvinyl alcohol, cellulose derivatives, polyamines and polyimines. Examples of the water-soluble ultraviolet absorber include sulfonated benzophenone and sulfonated benzotriazole. Examples of the dye solubilizer include ε-caprolactam, ethylene carbonate, urea and the like. Examples of the surfactant include known surfactants such as anionic, cationic, and nonionic surfactants. For example, acetylene glycol surfactants are also preferably used.

<Layer to be added>
The dye of the present invention is contained in at least one layer on the side on which the image forming layer is coated or at least one layer on the surface opposite to the side on which the image forming layer is coated. It is possible to coat them on both sides. At this time, an embodiment in which the polyhalogen compound is contained in at least one layer on the side where the photosensitive layer is coated is also preferable.

<Range of addition amount>
The addition amount of the dye is determined in combination with the color tone brought about by the silver color tone or other additives in order to adjust the color tone of the image after the heat development processing to blue. In general, the optical density (absorbance) when measured at the target wavelength is used in an amount not exceeding 1.5. The optical density is from 0.01 to 1.2, preferably from 0.05 to 0.10, more preferably from 0.1 to 0.8. The amount of dye used to obtain such an optical density is generally about 0.5 to 200 mg / m ² , preferably about 1 to 160 mg / m ² , and about 5 to 120 mg / m ² .

(Layer structure and components)
1) Layer constitution In the photothermographic material of the invention, as an essential layer constitution, (1) an image forming layer and (2) an outermost layer are arranged in this order from the support side. Preferably, a non-photosensitive intermediate layer is provided between the image forming layer and the outermost layer, more preferably a plurality of non-photosensitive intermediate layers, wherein the non-photosensitive intermediate layer A adjacent to the image forming layer is provided. The non-photosensitive intermediate layer B that is mainly composed of polymer latex and is adjacent to the outermost layer is a layer mainly composed of a hydrophilic polymer derived from animal protein. Each layer may be a single layer or two or more layers, and further layers may be provided.

  Usually, the role of the outermost layer is to form the outermost surface of the image forming surface of the photothermographic material, so that the transportability of the photothermographic material is improved and the surface is protected, and adhesion to other surfaces and members is prevented. It is to prevent image damage. Therefore, it is more preferable that additives such as a matting agent, a slipping agent, and a surfactant be added to the outermost layer in addition to the binder.

2) Outermost layer <polymer latex>
In the present invention, 50% by mass or more of the outermost binder is formed from a polymer latex. Preferably, the preferable content of the polymer latex is 50% by mass or more and 100% by mass or less, and more preferably 50% by mass or more and 75% by mass or less.

The polymer latex in the present invention is preferably a polymer having an equilibrium water content of 5% by mass or less at 25 ° C. and 60% RH. “Equilibrium moisture content at 25 ° C. and 60% RH” means that the following is used: Can be expressed as:
Equilibrium moisture content at 25 ° C. and 60% RH = {(W1−W0) / W0} × 100 (mass%)

  The equilibrium moisture content in the present invention is preferably 2% by mass or less, more preferably 0.01% by mass or more and 1.5% by mass or less, and further preferably 0.02% by mass or more and 1% by mass or less.

  The glass transition temperature of the polymer latex in the present invention is preferably 0 ° C. or higher and 80 ° C. or lower, more preferably 10 ° C. or higher and 70 ° C. or lower, and further preferably 15 ° C. or higher and 60 ° C. or lower.

Specific examples of the polymer latex that can be used in the present invention include polyacrylate, polyurethane, polymethacrylate, or a latex of a copolymer containing these.
The polymer latex that can be used in the present invention may be used in combination of two or more as required. Further, a glass transition temperature of 20 ° C. or higher and a glass transition temperature of less than 20 ° C. may be used in combination. When two or more kinds of polymers having different Tg are blended, the mass average Tg is preferably within the above range.

In this invention, it is preferable to apply | coat and dry using the coating liquid whose 30 mass% or more of a solvent is water, and to form a hydrophobic polymer content layer.
A preferred form is one prepared so that the ionic conductivity is 2.5 mS / cm or less, and examples of such a preparation method include a purification method using a separation functional membrane after polymer synthesis.

  The coating solvent is preferably water or a mixture of 70% by mass or less of a water-miscible organic solvent in water. Examples of the water-miscible organic solvent include alcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol, cellosolvs such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve, ethyl acetate, and dimethylformamide.

  In the present invention, a polymer dispersible in an aqueous solvent is particularly preferred. Examples of the dispersed state may be either latex in which fine particles of water-insoluble hydrophobic polymer are dispersed or polymer molecules dispersed in a molecular state or forming micelles. preferable. The average particle size of the dispersed particles is 1 nm or more and 50000 nm or less, preferably 5 nm or more and 1000 nm or less, more preferably 10 nm or more and 500 nm or less, and further preferably 50 nm or more and 200 nm or less. 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. Mixing two or more types having a monodispersed particle size distribution is also a preferable method for controlling the physical properties of the coating solution.

  Preferred embodiments of the hydrophobic polymer include acrylic polymers, poly (esters), rubbers (eg, SBR resin), poly (urethanes), poly (vinyl chloride) s, poly (vinyl acetate) s, poly (chloride chloride). Hydrophobic polymers such as vinylidene) and poly (olefin) s can be preferably used. These polymers may be linear polymers, branched polymers, crosslinked polymers, so-called homopolymers obtained by polymerizing a single monomer, or copolymers obtained by polymerizing two or more types of monomers. In the case of a copolymer, it may be a random copolymer or a block copolymer. The molecular weight of these polymers is 5,000 to 1,000,000, preferably 10,000 to 200,000 in terms of number average molecular weight. When the molecular weight is too small, the mechanical strength of the image forming layer is insufficient, and when the molecular weight is too large, the film formability is poor, which is not preferable. A crosslinkable polymer latex is particularly preferably used.

<Specific examples of latex>
Specific examples of the preferred polymer latex include the following. Below, it represents using a raw material monomer, the numerical value in a parenthesis is the mass%, and molecular weight is a number average molecular weight. When a polyfunctional monomer was used, the concept of molecular weight was not applicable because a crosslinked structure was formed, so it was described as crosslinkable and the molecular weight description was omitted. Tg represents the glass transition temperature.

NP-1; -MMA (70) -EA (27) -MAA (3)-latex (molecular weight 37000, Tg 61 ° C.)
NP-2; latex of MMA (70) -2EHA (20) -St (5) -AA (5)-(molecular weight 40000, Tg 59 ° C.)
NP-3; Latex of -St (55) -Bu (42) -MAA (3)-(crosslinkability, Tg 5 ° C.)
-NP-4; -St (68) -Bu (29) -AA (3)-latex (crosslinkable, Tg 17 ° C)
NP-5; Latex of -St (71) -Bu (26) -AA (3)-(crosslinkability, Tg 24 ° C.)
NP-6; Latex (crosslinkable) of -St (70) -Bu (27) -IA (3)-
NP-7; latex of -St (75) -Bu (24) -AA (1)-(crosslinkability, Tg 29 ° C.)
NP-8; Latex (crosslinkable) of -St (60) -Bu (35) -DVB (3) -MAA (2)-
NP-9; Latex (crosslinkability) of -St (70) -Bu (25) -DVB (2) -AA (3)-
NP-10; latex of -VC (50) -MMA (20) -EA (20) -AN (5) -AA (5)-(molecular weight 80,000)
NP-11; latex of -VDC (85) -MMA (5) -EA (5) -MAA (5)-(molecular weight 67000)
NP-12; -Et (90) -MAA (10)-latex (molecular weight 12000)
NP-13; -St (70) -2EHA (27) -AA (3) latex (molecular weight 130,000, Tg 43 ° C.)
NP-14; latex of MMA (63) -EA (35) -AA (2) (molecular weight 33,000, Tg 47 ° C.)
-NP-15; -St (70.5) -Bu (26.5) -AA (3) -latex (crosslinkability, Tg 23 ° C.)
NP-16; latex of -St (69.5) -Bu (27.5) -AA (3)-(crosslinkability, Tg 20.5 ° C)
-NP-17; latex of -St (61.3) -isoprene (35.5) -AA (3)-(crosslinkability, Tg17 ° C)
NP-18; latex of -St (67) -isoprene (28) -Bu (2) -AA (3)-(crosslinkability, Tg 27 ° C.)

  The abbreviations for the above structures represent the following monomers. MMA; Methyl methacrylate, EA; Ethyl acrylate, MAA; Methacrylic acid, 2EHA; 2-Ethylhexyl acrylate, St; Styrene, Bu; Butadiene, AA; Acrylic acid, DVB; Divinylbenzene, VC; Vinyl chloride, AN; Acrylonitrile, VDC Vinylidene chloride, Et; ethylene, IA; itaconic acid.

  The polymer latex described above is also commercially available, and the following polymers can be used. Examples of the acrylic polymer include Sebian A-4635, 4718, 4601 (manufactured by Daicel Chemical Industries, Ltd.), Nipol Lx811, 814, 821, 820, 857 (manufactured by Nippon Zeon Co., Ltd.), etc. Examples of poly (esters) include poly (urethane) such as FINETEX ES650, 611, 675, 850 (above, manufactured by Dainippon Ink Chemical Co., Ltd.), WD-size, WMS (above, manufactured by Eastman Chemical). Examples of rubbers include HYDRAN AP10, 20, 30, 40 (manufactured by Dainippon Ink Chemical Co., Ltd.), and examples of rubbers include LACSTAR 7310K, 3307B, 4700H, 7132C (above, Dainippon Ink Chemical Co., Ltd.). (Made by Co., Ltd.), Nipol Lx416, 410, 438C, 2507 (above, Nippon Zeo) As examples of poly (vinyl chloride) such as G351 and G576 (above, manufactured by Nippon Zeon Co., Ltd.), examples of poly (vinylidene chloride) such as L502, L513 (above Examples of poly (olefin) s such as Asahi Kasei Kogyo Co., Ltd. include Chemipearl S120 and SA100 (above Mitsui Petrochemical Co., Ltd.).

  These polymer latexes may be used alone or in combination of two or more as required.

  The polymer latex used in the hydrophobic polymer layer of the present invention is particularly preferably an acrylic polymer copolymer, polyester, polyurethane or the like. Moreover, it is preferable that the polymer latex used for the hydrophobic polymer layer of this invention contains 1-6 mass% of acrylic acid or methacrylic acid, More preferably, it contains 2-5 mass%. The polymer latex used in the hydrophobic polymer layer of the present invention preferably contains acrylic acid.

The application amount of the hydrophobic polymer (per 1 m ^{2 of} support) is preferably 0.1 g / m ² or more and 10 g / m ² or less, more preferably 0.3 g / m ² or more and 5 g / m ² or less.
The concentration in the coating solution is preferably adjusted so that the viscosity becomes a value suitable for simultaneous multilayer coating when added, but is not particularly limited. In general, the concentration in the liquid is 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 40% by mass or less, and particularly preferably 15% by mass or more and 30% by mass or less.

<Matting agent>
In the present invention, it is preferable to add a matting agent for improving transportability, and the matting agent is described in paragraph Nos. 0126 to 0127 of JP-A No. 11-65021. The matting agent is preferably 1 mg / m ² or more and 400 mg / m ² or less, more preferably 5 mg / m ² or more and 300 mg / m ² or less when expressed in terms of the coating amount per 1 m ² of the photosensitive material.
In the present invention, the shape of the matting agent may be either a regular shape or an irregular shape, but is preferably a regular shape, and a spherical shape is preferably used.
The volume weighted average of the equivalent sphere diameters of the matting agent used for the image forming layer surface is preferably from 0.3 μm to 10 μm, and more preferably from 0.5 μm to 7 μm. Further, the variation coefficient of the size distribution of the matting agent is preferably 5% or more and 80% or less, and more preferably 20% or more and 80% or less. Here, the coefficient of variation is a value represented by (standard deviation of particle size) / (average value of particle size) × 100. Further, two or more kinds of matting agents having different average particle sizes can be used as the matting agent on the image forming layer surface. In this case, the difference in particle size between the matting agent having the largest average particle size and the smallest matting agent is preferably 2 μm or more and 8 μm or less, and more preferably 2 μm or more and 6 μm or less.
The volume weighted average of the equivalent sphere diameters of the matting agent used for the back surface is preferably 1 μm or more and 15 μm or less, and more preferably 3 μm or more and 10 μm or less. The variation coefficient of the size distribution of the matting agent is preferably 3% or more and 50% or less, and more preferably 5% or more and 30% or less. Further, two or more kinds of matting agents having different average particle sizes can be used as the matting agent for the back surface. In that case, the difference in particle size between the matting agent having the largest average particle size and the smallest matting agent is preferably 2 μm or more and 14 μm or less, and more preferably 2 μm or more and 9 μm or less.

  The matting degree of the image forming layer surface may be any as long as no stardust failure occurs, but the Beck smoothness is preferably 30 seconds or more and 2000 seconds or less, particularly preferably 40 seconds or more and 1500 seconds or less. The Beck smoothness can be easily determined by Japanese Industrial Standard (JIS) P8119 “Smoothness test method using Beck tester for paper and paperboard” and TAPPI standard method T479.

  In the present invention, the matte degree of the back layer is preferably a Beck smoothness of 1200 seconds or less and 10 seconds or more, preferably 800 seconds or less and 20 seconds or more, and more preferably 500 seconds or less and 40 seconds or more.

  In the present invention, the matting agent is preferably contained in a layer functioning as the outermost layer or surface protective layer of the photosensitive material, or a layer close to the outermost layer.

<Slip agent>
In order to improve handling at the time of manufacture and scratch resistance at the time of heat development, it is preferable to use a sliding agent such as liquid paraffin, long chain fatty acid, fatty acid amide, fatty acid ester and the like. In particular, liquid paraffin from which low-boiling components have been removed and fatty acid esters having a branched structure and having a molecular weight of 1000 or more are preferred.

As the slip agent, compounds described in paragraph No. 0117 of JP-A No. 11-65021, JP-A No. 2000-5137, JP-A No. 2004-219794, JP-A No. 2004-21802, and JP-A No. 2004-334077 are preferable.
The amount of the slip agent used is in the range of 1 mg / m ^{2 to} 200 mg / m ² , preferably 10 mg / m ^{2 to} 150 mg / m ² , more preferably 20 mg / m ^{2 to} 100 mg / m ^2. .

  The layer to which the slip agent is added may be either an image forming layer or a non-image forming layer, but it is preferably added to the outermost layer for the purpose of improving transportability and scratch resistance.

<Surfactant>
JP-A No. 11-65021 paragraph No. 0132 for surfactants applicable to the present invention, paragraph No. 0133 for solvents, paragraph No. 0134 for supports, paragraph No. for antistatic or conductive layers The method for obtaining a color image is described in paragraph No. 0136 of the same publication, and the slip agent is described in paragraph Nos. 0061 to 0064 of JP-A No. 11-84573 and paragraph Nos. 0049 to 0062 of JP-A No. 2001-83679.
In the present invention, it is preferable to use a fluorosurfactant. Specific examples of the fluorosurfactant include compounds described in JP-A Nos. 10-197985, 2000-19680, 2000-214554 and the like. Further, a polymeric fluorine-based surfactant described in JP-A-9-281636 is also preferably used. In the photothermographic material of the present invention, it is preferable to use fluorine-based surfactants described in JP-A Nos. 2002-82411, 2003-057780, and 2003-149766. In particular, the fluorosurfactants described in JP-A-2003-057780 and JP-A-2003-149766 are preferable in terms of charge adjustment ability, stability of the coated surface, and smoothness when coating and production is performed with an aqueous coating solution. The fluorosurfactants described in JP-A No. 2003-149766 are most preferable in that they have a high charge adjusting ability and can be used in a small amount.
In the present invention, the fluorosurfactant can be used on either the image forming layer surface or the back surface, and is preferably used on both surfaces. Further, it is particularly preferable to use in combination with a conductive layer containing the above-described metal oxide. In this case, sufficient performance can be obtained even if the amount of the fluorosurfactant used on the surface having the conductive layer is reduced or removed.
The preferred amount of the fluorocarbon surfactant is an image forming layer side, the range to the back surface each ^{0.1mg / m 2 ~100mg / m 2} , more preferably 0.3mg / m ² ~30mg / m ² range, even more preferably from ^{1mg / m 2 ~10mg / m 2} . In particular JP fluorocarbon surfactant described in JP-A No. 2001-264110 is effective, and preferably in the range of ^{0.01mg / m 2 ~10mg / m 2} , more in the range of 0.1mg / m ² ~5mg / m ² preferable.

2) Non-photosensitive intermediate layer A
The non-photosensitive intermediate layer A is a layer having a film-forming binder between the image forming layer and the outermost layer. In addition to the binder, additives such as a development accelerator or inhibitor described later, dyes and contents, plasticizers and lubricants, and crosslinking agents and surfactants may be contained.

<Binder of non-photosensitive intermediate layer A>

A preferable binder for the non-photosensitive intermediate layer A is a polymer having a monomer component represented by the following general formula (M) in an amount of 10% by mass to 70% by mass.
General formula (M)
CH ₂ = CR ⁰¹ -CR ⁰² = CH ₂
In the formula, R ⁰¹ and R ⁰² are a group selected from a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a halogen atom, and a cyano group. More preferably, R ⁰¹ and R ⁰² are both hydrogen atoms, or one is a hydrogen atom and the other is a methyl group.

The preferred alkyl group for R ⁰¹ and R ^{02 is} an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 2 carbon atoms. The halogen atom for R ⁰¹ and R ⁰² is preferably a fluorine atom, a chlorine atom or a bromine atom, and more preferably a chlorine atom.
R ⁰¹ and R ⁰² are preferably both hydrogen atoms, one is a hydrogen atom and the other is a methyl group or a chlorine atom, more preferably both are hydrogen atoms, or one is a hydrogen atom and the other is a methyl group.

  Specific examples of the monomer represented by the general formula (M) of the present invention include 2-ethyl-1,3-butadiene, 2-n-propyl-1,3-butadiene, and 2,3-dimethyl-1,3. -Butadiene, 2-methyl-1,3-butadiene, 2-chloro-1,3-butadiene, 1-bromo-1,3-butadiene, 2-fluoro-1,3-butadiene, 2,3-dichloro- Examples include 1,3-butadiene and 2-cyano-1,3-butadiene.

The copolymerization ratio of the monomer represented by the general formula (M) in the present invention is 10% by mass to 70% by mass, preferably 15% by mass to 65% by mass, and more preferably 20% by mass to 60% by mass. %. When the copolymerization ratio of the monomer represented by the general formula (M) is less than 10% by mass, the fusion component of the binder decreases, and the work brittleness deteriorates.
On the other hand, when the copolymerization ratio of the monomer represented by the general formula (M) exceeds 70% by mass, the fusion component of the binder is increased and the mobility of the binder is increased, so that the image storage stability is deteriorated.

  As the acid group, carboxylic acid, sulfonic acid and phosphoric acid are preferable, and carboxylic acid is particularly preferable. The copolymerization ratio of the acid group is preferably 1% by mass to 20% by mass, and more preferably 1% by mass to 10% by mass. Specific examples of the monomer having an acid group include acrylic acid, methacrylic acid, itaconic acid, p-styrenesulfonic acid sodium salt, isoprenesulfonic acid, phosphorylethyl methacrylate and the like, and acrylic acid and methacrylic acid are preferable. Is particularly preferred.

  The binder of the present invention preferably has a glass transition temperature (Tg) in the range of −30 ° C. to 70 ° C., more preferably in the range of −10 ° C. to 50 ° C., more preferably in terms of film formability and image storage stability. Is in the range of 0 ° C to 40 ° C. It is also possible to use a blend of two or more polymers as the binder, and in this case, it is preferable that the weighted average Tg in consideration of the composition falls within the above range. Moreover, when phase-separating or having a core-shell structure, the weighted average Tg is preferably within the above range.

This glass transition temperature (Tg) can be calculated by the following formula.
1 / Tg = Σ (Xi / Tgi)
Here, it is assumed that n monomer components from i = 1 to n are copolymerized in the polymer.
Xi is the mass fraction of the i-th monomer (ΣXi = 1), and Tgi is the glass transition temperature (absolute temperature) of the homopolymer of the i-th monomer. However, Σ is the sum from i = 1 to n. The homopolymer glass transition temperature value (Tgi) of each monomer was the value of Polymer Handbook (3rd Edition) (by J. Brandrup, EH Immergut (Wiley-Interscience, 1989)).

  The polymer used for the binder of the present invention can be easily obtained by a solution polymerization method, suspension polymerization method, emulsion polymerization method, dispersion polymerization method, anionic polymerization method, cationic polymerization, etc., but the emulsion polymerization method obtained as a latex Is most preferred. In the emulsion polymerization method, for example, water or a mixed solvent of water and an organic solvent miscible with water (for example, methanol, ethanol, acetone, etc.) is used as a dispersion medium, and 5 mass% to 150 mass% with respect to the dispersion medium. The polymerization is carried out by stirring at 30 ° C. to 100 ° C., preferably 60 ° C. to 90 ° C. for 3 hours to 24 hours, using an emulsifier and a polymerization initiator with respect to the total monomer amount. Various conditions such as the dispersion medium, the monomer concentration, the initiator amount, the emulsifier amount, the dispersant amount, the reaction temperature, and the monomer addition method are appropriately set in consideration of the type of monomer used. Moreover, it is preferable to use a dispersing agent as needed.

The emulsion polymerization method can be generally performed according to the following literature. "Synthetic resin emulsion (Hiraku Okuda, Hiroshi Inagaki, published by Polymer Press (1978))", "Application of Synthetic Latex (Takaaki Sugimura, Tatsuo Kataoka, Junichi Suzuki, Keiji Kasahara, Published by Polymer Press (1993) ) ”,“ Synthetic Latex Chemistry (by Soichi Muroi, published by Kobunshi Shuppankai (1970)) ”.
In the emulsion polymerization method for synthesizing the polymer latex of the present invention, a batch polymerization method, a monomer (continuous / divided) addition method, an emulsion addition method, a seed polymerization method, and the like can be selected. A combination method, a monomer (continuous / divided) addition method, and an emulsion addition method are preferred.

  The polymerization initiator only needs to have radical generating ability, such as inorganic peroxides such as persulfate and hydrogen peroxide, peroxides described in Nippon Oil & Fats Co., Ltd. organic peroxide catalog, and Wako Pure Chemical Industries, Ltd. The azo compounds described in the azo polymerization initiator catalog can be used. Among these, water-soluble peroxides such as persulfate and water-soluble azo compounds described in the Wako Pure Chemical Industries, Ltd. Azo Polymerization Initiator Catalog are preferable. Ammonium persulfate, sodium persulfate, potassium persulfate, azobis ( 2-methylpropionamidine) hydrochloride, azobis (2-methyl-N- (2-hydroxyethyl) propionamide), azobiscyanovaleric acid is more preferable, and in particular, peroxidation such as ammonium persulfate, sodium persulfate, potassium persulfate and the like. The product is preferable from the viewpoint of image preservability, solubility, and cost.

  As the addition amount of the polymerization initiator, the polymerization initiator is preferably 0.3% by mass to 2.0% by mass, and 0.4% by mass to 1.75% by mass with respect to the total amount of monomers. Is more preferable, and 0.5% by mass to 1.5% by mass is particularly preferable. When the amount of the polymerization initiator is less than 0.3% by mass, the image storability is lowered, and when it exceeds 2.0%, the latex tends to aggregate and the coatability is lowered.

  As the polymerization emulsifier, any of an anionic surfactant, a nonionic surfactant, a cationic surfactant, and an amphoteric surfactant can be used, but the anionic surfactant has dispersibility and image storability. From the viewpoint, it is preferable to use a sulfonic acid type anionic surfactant because polymerization stability can be secured in a small amount and it has hydrolysis resistance, and long-chain alkyl diphenyl ether disulfone represented by Perex SS-H (Kao Co., Ltd.). Acid salts are more preferable, and a low electrolyte type such as Pionine A-43-S (Takemoto Yushi Co., Ltd.) is particularly preferable.

  As the polymerization emulsifier, a sulfonic acid type anionic surfactant is preferably used in an amount of 0.1% by mass to 10.0% by mass with respect to the total amount of monomers, and 0.2% by mass to 7.5% by mass is used. It is more preferable that 0.3% by mass to 5.0% by mass is used. If the polymerization emulsifier is less than 0.1% by mass, stability during emulsion polymerization cannot be ensured, and if it exceeds 10.0%, the image storage stability decreases.

  In the synthesis of the polymer latex used in the present invention, it is preferable to use a chelating agent. The chelating agent is a compound capable of coordinating (chelating) multivalent ions such as metal ions such as iron ions and alkaline earth metal ions such as calcium ions. Japanese Patent Publication No. 6-8956, US Pat. -73645, JP-A-4-127145, JP-A-4-247703, JP-A-4-305572, JP-A-6-11805, JP-A-5-1773312, JP-A-5-66527, JP-A-5-67527. 158195, JP-A-6-118580, JP-A-6-110168, JP-A-6-161054, JP-A-6-175299, JP-A-6-214352, JP-A-7-114161, JP-A-7-114154 JP-A-7-120894, JP-A-7-199433, JP-A-7-306504, JP-A-9-4379 No., JP-A-8-314090, JP-A-10-182571, JP-A-10-182570, can be employed compounds described in JP-A-11-190892.

  Examples of the chelating agent include inorganic chelate compounds (sodium tripolyphosphate, sodium hexametaphosphate, sodium tetrapolyphosphate, etc.), aminopolycarboxylic acid chelate compounds (nitrilotritriacetic acid, ethylenediaminetetraacetic acid, etc.), organic phosphonic acid chelate compounds ( Research Disclosure 18170, JP-A-52-102726, 53-42730, 56-97347, 54-121127, 55-4024, 55-4025, 55-29883, 55 -126241, 55-65955, 55-65956, 57-17943, 54-61125, and West German Patent No. 1045373), polyphenol-based chelating agents, polyamine-based chelates Preferably such DOO compounds, with aminopolycarboxylic acid derivatives being particularly preferred.

  Preferable examples of the aminopolycarboxylic acid derivatives include the compounds listed in the appendix of “EDTA (-Complexane Chemistry)” (Nanedo, 1977), and some of the carboxyl groups of these compounds are sodium or potassium. Alkali metal salts and ammonium salts such as may be substituted. Particularly preferred aminocarboxylic acid derivatives include iminodiacetic acid, N-methyliminodiacetic acid, N- (2-aminoethyl) iminodiacetic acid, N- (carbamoylmethyl) iminodiacetic acid, nitrilotriacetic acid, ethylenediamine-N, N '-Diacetic acid, ethylenediamine-N, N'-di-α-propionic acid, ethylenediamine-N, N'-di-β-propionic acid, N, N'-ethylene-bis (α-o-hydroxyphenyl) glycine N, N′-di (2-hydroxybenzyl) ethylenediamine-N, N′-diacetic acid, ethylenediamine-N, N′-diacetic acid-N, N′-diacethydroxamic acid, N-hydroxyethylethylenediamine-N , N ′, N′-triacetic acid, ethylenediamine-N, N, N ′, N′-tetraacetic acid, 1,2-propylenediamine-N, N, N ′ N′-tetraacetic acid, d, l-2,3-diaminobutane-N, N, N ′, N′-tetraacetic acid, meso-2,3-diaminobutane-N, N, N ′, N′-four Acetic acid, 1-phenylethylenediamine-N, N, N ′, N′-tetraacetic acid, d, l-1,2-diphenylethylenediamine-N, N, N ′, N′-tetraacetic acid, 1,4-diaminobutane -N, N, N ', N'-tetraacetic acid, trans-cyclobutane-1,2-diamine-N, N, N', N'-tetraacetic acid, trans-cyclopentane-1,2-diamine-N, N, N ′, N′-tetraacetic acid, trans-cyclohexane-1,2-diamine-N, N, N ′, N′-tetraacetic acid, cis-cyclohexane-1,2-diamine-N, N, N ′ , N′-tetraacetic acid, cyclohexane-1,3-diamine-N, N, N ′, N′-four Acid, cyclohexane-1,4-diamine-N, N, N ′, N′-tetraacetic acid, o-phenylenediamine-N, N, N ′, N′-tetraacetic acid, cis-1,4-diaminobutene- N, N, N ′, N′-tetraacetic acid, trans-1,4-diaminobutene-N, N, N ′, N′-tetraacetic acid, α, α′-diamino-o-xylene-N, N, N ′, N′-tetraacetic acid, 2-hydroxy-1,3-propanediamine-N, N, N ′, N′-tetraacetic acid, 2,2′-oxy-bis (ethyliminodiacetic acid), 2,2 '-Ethylenedioxy-bis (ethyliminodiacetic acid), ethylenediamine-N, N'-diacetic acid-N, N'-di-α-propionic acid, ethylenediamine-N, N'-diacetic acid-N, N'- Di-β-propionic acid, ethylenediamine-N, N, N ′, N′-tetrapropionic acid Diethylenetriamine-N, N, N ′, N ″, N ″ -pentaacetic acid, triethylenetetramine-N, N, N ′, N ″, N ′ ″, N ′ ″-hexaacetic acid, 1, 2,3-triaminopropane-N, N, N ′, N ″, N ′ ″, N ′ ″-hexaacetic acid, and some of the carboxyl groups of these compounds include sodium and potassium. Substituted ones such as alkali metal salts and ammonium salts can also be mentioned.

  The addition amount of the chelating agent is preferably 0.01% by mass to 0.4% by mass, more preferably 0.02% by mass to 0.3% by mass with respect to the total amount of monomers. It is especially preferable that it is 03 mass%-0.15 mass%. When the amount of the chelating agent is less than 0.01% by mass, capture of metal ions mixed in the production process of the polymer latex becomes insufficient, stability against aggregation of the latex is lowered, and applicability is deteriorated. On the other hand, if it exceeds 0.4%, the viscosity of the latex increases and the coatability is lowered.

  A chain transfer agent is preferably used for the synthesis of the polymer latex used in the present invention. The gelation rate can be controlled by the amount of chain transfer agent added. As the chain transfer agent, those described in Polymer Handbook, 3rd edition, (Wiley-Interscience, 1989) are preferable. Sulfur compounds are more preferred because they have high chain transfer ability and can be used in small amounts. Hydrophobic mercaptan-based chain transfer agents such as tert-dodecyl mercaptan and n-dodecyl mercaptan are particularly preferred.

  The amount of the chain transfer agent is preferably 0.2% by mass to 2.0% by mass, more preferably 0.3% by mass to 1.8% by mass, and 0.4% by mass to 1.6% by mass with respect to the total amount of monomers. Mass% is particularly preferred.

  In emulsion polymerization, in addition to the above compounds, electrolytes, stabilizers, thickeners, antifoaming agents, antioxidants, vulcanizing agents, antifreezing agents, gelling agents, vulcanization accelerators, etc. are described in synthetic rubber handbooks, etc. These additives may be used.

<Specific examples of polymer>
As specific examples of the polymer used in the present invention, Table 1 shows exemplary compounds (P-1) to (P-
17), the present invention is not limited to these specific examples.

As a synthesis example of the polymer used in the present invention, a synthesis example of compound P-1 is shown.
The present invention is not limited to the synthesis methods shown here. Other exemplified compounds can be synthesized by the same synthesis method.

Add 1500g of distilled water to the polymerization kettle of the gas monomer reactor (Pressure Glass Industry Co., Ltd. TAS-2J type), heat at 90 ° C for 3 hours, and passivate to the stainless steel surface of the polymerization kettle and members of the stainless steel stirrer A film is formed. In this polymerized kettle, 582.28 g of distilled water bubbled with nitrogen gas for 1 hour, 9.49 g of surfactant (Pionin A-43-S (manufactured by Takemoto Yushi Co., Ltd.)), 1 mol / L NaOH Of ethylenediaminetetraacetic acid tetrasodium salt 0.20 g, styrene 314.99 g, isoprene 190.87 g, acrylic acid 10.43 g, tert-dodecyl mercaptan 2.09 g, and the reaction vessel was sealed and stirred at 225 rpm. The mixture was stirred and heated to an internal temperature of 65 ° C. A solution prepared by dissolving 2.61 g of ammonium persulfate in 40 mL of water was added thereto, and the mixture was stirred as it was for 2 hours. Then, it heated up to 65 degreeC of internal temperature and stirred for 4 hours. At this time, the polymerization conversion rate was 90% from the measurement of the solid content. Here, a solution in which 5.22 g of acrylic acid was dissolved in 46.98 g of water was added, 10 g of water was subsequently added, and a solution in which 1.30 g of ammonium persulfate was dissolved in 50.7 mL of water was further added. After the addition, the temperature was raised to 90 ° C. and stirred for 3 hours. After the reaction was completed, the internal temperature was lowered to room temperature, and then Na ⁺ ions: NH ₄ ⁺ ions were used with 1 mol / L NaOH and NH ₄ OH. = 1: 5.3 (molar ratio) was added and adjusted to pH 8.4. Thereafter, the mixture was filtered with a polypropylene filter having a pore size of 1.0 μm to remove foreign substances such as dust and stored, and 1248 g of isoprene latex P-1 was obtained. When the halogen ions were measured by ion chromatography, the chloride ion concentration was 3 ppm. As a result of measuring the concentration of the chelating agent by high performance liquid chromatography, it was 142 ppm. Average particle size 113 nm, Tg = 15 ° C., solid content concentration 41.3 mass%, gelation rate 50.0 mass%, ion conductivity 5.23 mS / cm (measurement of ion conductivity is made by Toa Denpa Kogyo Co., Ltd.) Conductivity meter CM-30S was used and measured at 25 ° C.) and Tg was 15 ° C.

  In the polymer latex used in the present invention, an aqueous solvent can be used as a solvent in the coating solution, but a water-miscible organic solvent may be used in combination. 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. The amount of these organic solvents added is preferably 50% or less, more preferably 30% or less of the solvent.

  The polymer latex used in the present invention preferably has a polymer concentration of 10% by mass to 70% by mass with respect to the latex liquid, more preferably 20% by mass to 60% by mass, and particularly preferably 30% to 55% by mass. Is preferred.

  The polymer latex in the present invention preferably has an equilibrium water content of 2% by mass or less at 25 ° C. and 60% RH. More preferably, the equilibrium water content is 0.01% by mass or more and 1.5% by mass or less, and further preferably 0.02% by mass or more and 1.0% by mass or less.

  The average particle size of the latex particles in the present invention is in the range of 1 nm to 50000 nm, preferably in the range of 5 nm to 1000 nm, more preferably in the range of 10 nm to 500 nm, still more preferably in the range of 50 nm to 200 nm. The particle size distribution is not particularly limited, and may have a wide particle size distribution or a monodispersed particle size distribution. Mixing two or more types having a monodispersed particle size distribution is also a preferable method for controlling the physical properties of the coating solution.

  In the present invention, a hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose, or carboxymethylcellulose may be added to the non-photosensitive intermediate layer A as necessary. The amount of these hydrophilic polymers added is preferably 50% by mass or less, more preferably 20% by mass or less, based on the total binder of the non-photosensitive intermediate layer A.

Total binder coating amount of the non-photosensitive intermediate layer A of the present invention is preferably ^{0.5g / m 2 ~3.0g / m 2} , more preferably from 1.0g / m ² ~2.0g / m ² It is.

3) Non-photosensitive intermediate layer B
In the present invention, the non-photosensitive intermediate layer B is a layer adjacent to the outermost layer and containing 50% by mass or more of a hydrophilic polymer. The preferable content rate of a hydrophilic polymer is 50 to 100 mass%, More preferably, it is 60 to 100 mass%. In the present invention, the hydrophilic polymer of the non-photosensitive intermediate layer B is preferably a hydrophilic polymer derived from animal protein. The hydrophilic polymer derived from animal protein refers to a water-soluble polymer that is naturally or chemically modified, such as glue, casein, gelatin, and egg white.
Gelatin is preferred, and acid-treated gelatin and alkali-treated gelatin (such as lime treatment) are available depending on the synthesis method, and both can be preferably used. It is preferable to use gelatin having a molecular weight of 10,000 to 1,000,000. In addition, modified gelatin modified by utilizing the amino group or carboxyl group of gelatin can be used (for example, phthalated gelatin). As gelatin, inert gelatin (for example, Nitta gelatin 750), phthalated gelatin (for example, Nitta gelatin 801), or the like can be used.
The gelatin aqueous solution becomes sol when heated to a temperature of 30 ° C. or higher, and gels and loses fluidity when lowered to a temperature lower than 30 ° C. Since such a sol-gel change occurs reversibly with temperature, the gelatin aqueous solution which is a coating solution has a set property of losing fluidity when cooled to a temperature lower than 30 ° C.

  Moreover, the following hydrophilic polymer and hydrophobic polymer which are not derived from animal protein can be used together with the hydrophilic polymer derived from animal protein.

  A crosslinking agent, a surfactant, a pH adjuster, an antiseptic, an antifungal agent, a dye, a pigment, a color tone adjuster, and the like can be added to the non-photosensitive intermediate layer B layer.

The hydrophilic polymer not derived from animal protein in the present invention is a natural polymer (polysaccharide, microbial, animal) other than animal protein such as gelatin, semi-synthetic polymer (cellulose, starch, alginic acid). ) And synthetic polymers (vinyl-based, etc.), which are synthetic polymers such as polyvinyl alcohol described below, and natural or semi-synthetic polymers made from plant-derived cellulose or the like. Polyvinyl alcohols and acrylic acid-vinyl alcohol copolymer polymers are preferable.
A hydrophilic polymer not derived from animal protein does not have setability, but when used together with a gelling agent, it has setability and good coating performance.

As the hydrophobic polymer, a polymer dispersible in an aqueous solvent is preferable.
Suitable water-dispersible polymers include synthetic resins, polymers and copolymers, and other film-forming media such as cellulose acetates, cellulose acetate butyrate, poly (methyl methacrylic acid), poly (vinyl chloride) , Poly (methacrylic acid) s, styrene-maleic anhydride copolymers, styrene-acrylonitrile copolymers, styrene-butadiene copolymers, poly (vinyl acetal) s (eg, poly (vinyl formal) and Poly (vinyl butyral)), poly (ester), poly (urethane), phenoxy resin, poly (vinylidene chloride), poly (epoxide), poly (carbonate), poly (vinyl acetate), poly ( Olefins), cellulose esters, poly (amides) Kill.
Specific examples include latex that can be used for the non-photosensitive intermediate layer A of the present invention, polyacrylate, polyurethane, polymethacrylate, or a copolymer latex containing these.

4) Auxiliary additives The intermediate layers A and B and the outermost layer can contain various auxiliary additives depending on the purpose in addition to the binder.

<Gelling agent>
The gelling agent in the present invention is a substance that causes gelation of a solution when added to a hydrophilic polymer aqueous solution or a hydrophobic polymer latex aqueous solution that is not derived from animal protein in the present invention and is cooled, or a gelation promoting substance. It is a substance that causes gelation when used in combination. By causing gelation, the fluidity is significantly reduced.

  Specific examples of the gelling agent include the following water-soluble polysaccharides. That is, agar, κ-carrageenan, ι-carrageenan, alginic acid, alginate, agarose, furceleran, gellan gum, glucono delta lactone, azotobacter vineland gum, xanthan gum, pectin, guar gum, locust bean gum, tara gum, cassia gum, gluco It is at least one selected from mannan, gum tragacanth, karaya gum, pullulan, gum arabic, arabinogalactan, dextran, carboxymethylcellulose sodium salt, methylcellulose, silium sheet gum, starch, chitin, chitosan and curdlan.

  Examples of the substance that gels by cooling after being heated and dissolved include substances such as agar, carrageenan, and julan gum.

  Among these gelling agents, κ-carrageenan (eg: K-9F, manufactured by Taisho Co., Ltd .: Nitta Gelatin Co., Ltd .: K-15: K-21-24, I— 3), iota-carrageenan and agar are mentioned, and κ-carrageenan is particularly preferred.

  The gelling agent is 0.01% by mass or more and 10.0% by mass or less, preferably 0.02% by mass or more and 5.0% by mass or less, more preferably 0.05% by mass or more and 2.% by mass or more with respect to the binder polymer. It is preferable to use 0% by mass or less.

<Geling accelerator>
The gelling agent is preferably used together with a gelling accelerator. The gelation accelerator in the present invention is a compound that promotes gelation by contact with the gelling agent, and its function is exhibited by a specific combination with the gelling agent. In the present invention, the following combinations can be used as the combination of the gelling agent and the gelation accelerator.

  ・ Alkaline metal ions such as potassium, or alkaline earth metal ions such as calcium and magnesium as gelling accelerators, and carrageenan, alginate, gellan gum, azotobacter vineland gum, pectin, carboxymethylcellulose sodium salt as gelling agents Combination of etc.

  ・ A combination of boric acid and other boron compounds as gelling accelerators and guar gum, locust bean gum, tara gum, cassia gum, etc. as gelling agents.

  -A combination of acid or alkali as a gelling accelerator and alginate, glucomannan, pectin, chitin, chitosan, curdlan, etc. as a gelling agent.

  A water-soluble polysaccharide that reacts with a gelling agent to form a gel is used as a gelation accelerator. Specifically, a combination using xanthan gum as the gelling agent, using cassia gum as the gelling agent, using carrageenan as the gelling agent, and using locust bean gum as the gelling agent can be exemplified.

The following a) -g) can be illustrated as a specific example of the combination of these gelling agents and gelation accelerators.
a) Combination of κ-carrageenan and potassium b) Combination of ι-carrageenan and calcium c) Combination of ro-methoxyl pectin and calcium d) Combination of sodium alginate and calcium e) Combination of gellan gum and calcium f) Combination of gellan gum and acid g) Combination of Locust Bingham and Xanthan Gum Such a combination may be used in combination.

  These gelation accelerators may be added to the same layer to which the gelling agent is added, but it is preferable to add them to different layers and act. More preferably, it is added to a layer not directly adjacent to the layer to which the gelling agent is added. That is, it is more preferable to have a layer containing neither a gelling agent nor a gelling accelerator between a layer containing a gelling agent and a layer containing a gelling accelerator.

  The gelling accelerator is used in an amount of 0.1 to 200% by mass, preferably 1.0 to 100% by mass, based on the gelling agent.

  In addition, additives can be appropriately added to the hydrophilic polymer-containing layer. Examples of such additives include surfactants, pH adjusters, preservatives, antifungal agents, dyes, pigments, color tone adjusters, and the like.

<Filming aid>
In order to control the minimum film forming temperature of the aqueous dispersion of the hydrophobic polymer, a film forming aid may be added. A film-forming aid, also called a plasticizer, is an organic compound (usually an organic solvent) that lowers the minimum film-forming temperature of polymer latex. For example, “Synthetic latex chemistry” (published by Soichi Muroi, published by Kobunshi Publishing Co. (1970)) Preferred film-forming aids are the following compounds, but the compounds that can be used in the present invention are not limited to the following specific examples.
Z-1: benzyl alcohol Z-2: 2,2,2,4-tetramethylpentanediol-1,3-monoisobutyrate Z-3: 2-dimethylaminoethanol Z-4: diethylene glycol

<Crosslinking agent>
In the present invention, it is preferable to incorporate a crosslinking agent in any layer on the image forming layer surface. More preferably, it is a case where it is added to the hydrophilic polymer 1-containing layer or the hydrophilic polymer 2-containing layer such as the non-photosensitive intermediate layer B. By adding a crosslinking agent, the hydrophobicity and water resistance of the non-photosensitive intermediate layer are increased, and an excellent photothermographic material is obtained.

  As a crosslinking agent, what is necessary is just to contain two or more groups which react with an amino group or a carboxyl group in a molecule | numerator, and it does not specifically limit about the kind of crosslinking agent. Examples of cross-linking agents include T.W. H. "THE THEORY OF THE PHOTOGRAPHIC PROCESS FOURTH EDITION" by James (published by McMillan Publishing Co., Inc., 1977), pages 77-87, and inorganic compound cross-linking agents (for example, chromium alum) Any of the compound crosslinking agents is preferred, but organic compound crosslinking agents are more preferred.

The crosslinking agent for the hydrophobic polymer-containing layer such as the non-photosensitive intermediate layer A of the present invention may contain a plurality of groups that react with carboxyl groups in the molecule, and the type of the crosslinking agent is not particularly limited. .
Preferred examples of the organic compound crosslinking agent include carboxylic acid derivatives, carbamic acid derivatives, sulfonic acid ester compounds, sulfonyl compounds, epoxy compounds, aziridine compounds, isocyanate compounds, carbodiimide compounds, and oxazoline compounds. More preferred are epoxy compounds, isocyanate compounds, carbodiimide compounds and oxazoline compounds. These crosslinking agents may be used alone or in combination of two or more.

  Specific examples include the following compounds, but the present invention is not limited to the following examples.

<< carbodiimide compound >>
Water-soluble or water-dispersible carbodiimide compounds are preferred. Examples include polycarbodiimides derived from isophorone diisocyanate described in JP-A-59-187029 and JP-B-5-27450, and JP-A-7-330849. Examples thereof include carbodiimide compounds derived from tetramethylxylylene diisocyanate, other branched carbodiimide compounds described in JP-A-10-30024, and carbodiimide compounds derived from dicyclohexylmethane diisocyanate described in JP-A 2000-7642.

<Oxazoline compound>
Water-soluble or water-dispersible oxazoline compounds are preferable, and examples thereof include oxazoline compounds described in JP-A No. 2001-215653.

<< Isocyanate compound >>
Since it is a compound that can react with water, a water-dispersible isocyanate compound is preferable from the viewpoint of pot life, and a compound having self-emulsifying properties is particularly preferable. Examples include JP-A-7-304841, JP-A-8-277315, JP-A-10-45866, JP-A-9-71720, JP-A-9-328654, JP-A-9-104814. And water dispersible isocyanate compounds described in JP-A Nos. 2000-194045, 2000-194237, and 2003-64149.

<< Epoxy compound >>
Water-soluble or water-dispersible epoxy compounds are preferred, and examples thereof include water-dispersible epoxy compounds described in JP-A-6-329877 and JP-A-7-309954.

  Although the more specific example of the crosslinking agent which can be used for this invention is shown below, this invention is not limited to the following examples.

-Epoxy compound Product name: Dick Fine EM-60 (Dainippon Ink Chemical Co., Ltd.)

・ Isocyanate compound Product name: Duranate WB40-100 (Asahi Kasei Corporation)
Duranate WB40-80D (Asahi Kasei Corporation)
Duranate WT20-100 (Asahi Kasei Corporation)
Duranate WT30-100 (Asahi Kasei Corporation)
CR-60N (Dainippon Ink Chemical Co., Ltd.)

・ Carbodiimide compound Product name: Carbodilite V-02 (Nisshinbo Co., Ltd.)
Carbodilite V-02-L2 (Nisshinbo Co., Ltd.)
Carbodilite V-04 (Nisshinbo Co., Ltd.)
Carbodilite V-06 (Nisshinbo Co., Ltd.)
Carbodilite E-01 (Nisshinbo Co., Ltd.)
Carbodilite E-02 (Nisshinbo Co., Ltd.)

・ Oxazoline compound Product name: Epocross K-1010E (Nippon Shokubai Co., Ltd.)
Epocross K-1020E (Nippon Shokubai Co., Ltd.)
Epocross K-1030E (Nippon Shokubai Co., Ltd.)
Epocross K-2010E (Nippon Shokubai Co., Ltd.)
Epocross K-2020E (Nippon Shokubai Co., Ltd.)
Epocross K-2030E (Nippon Shokubai Co., Ltd.)
Epocross WS-500 (Nippon Shokubai Co., Ltd.)
Epocross WS-700 (Nippon Shokubai Co., Ltd.)

  The crosslinking agent used in the present invention may be added in a state of being premixed in the binder solution, may be added at the end of the coating liquid preparation process, or may be added immediately before coating.

  As a usage-amount of the crosslinking agent used for this invention, it is preferable that it is 0.5 mass part-200 mass parts with respect to 100 mass parts of binders of the constituent layer contained, and it is 2 mass parts-100 mass parts. Is more preferable, and more preferably 3 parts by mass to 50 parts by mass.

<Thickener>
It is preferable to add a thickener to the coating solution for forming the non-photosensitive intermediate layer A. It is preferable to add a thickener since a hydrophobic layer having a uniform thickness can be formed. As the thickener, for example, an alkali metal salt of polyvinyl alcohol, hydroxyethyl cellulose, or carboxymethyl cellulose is used, but a thixotropic one is preferable in consideration of ease of handling. Therefore, hydroxyethyl cellulose, sodium hydroxymethylcarboxylate, Carboxymethyl-hydroxyethylcellulose is used.
The viscosity of the non-photosensitive intermediate layer A coating solution to which a thickener is added is preferably 1 mPa · s or more and 200 mPa · s or less at 40 ° C., and preferably 10 mPa · s or more and 100 mPa · s or less. More preferably, it is 15 mPa · s or more and 60 mPa · s or less.

(Description of organic silver salt)
1) Composition The organic silver salt that can be used in the present invention is relatively stable to light, but is heated to 80 ° C. or higher in the presence of exposed photosensitive silver halide and a reducing agent. In this case, the silver salt functions as a silver ion supplier to form a silver image. The organic silver salt may be any organic substance that can supply silver ions that can be reduced by a reducing agent. As for such non-photosensitive organic silver salt, paragraph numbers 0048 to 0049 of JP-A-10-62899, page 18 line 24 to page 19 line 37 of European Patent Publication No. 0803764A1, European Patent Publication. No. 0968212A1, JP-A-11-349591, JP-A-2000-7683, JP-A-2000-72711, and the like. Silver salts of organic acids, particularly silver salts of long-chain aliphatic carboxylic acids (having 10 to 30, preferably 15 to 28 carbon atoms) are preferred. Preferable examples of the fatty acid silver salt include silver lignocerate, silver behenate, silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, silver erucate and the like. Including a mixture of In the present invention, among these fatty acid silvers, the silver behenate content is preferably 50 mol% to 100 mol%, more preferably 85 mol% to 100 mol%, still more preferably 95 mol% to 100 mol%. The following fatty acid silver is preferably used. Furthermore, it is preferable to use fatty acid silver having a silver erucate content of 2 mol% or less, more preferably 1 mol% or less, and still more preferably 0.1 mol% or less.

  Moreover, it is preferable that silver stearate content rate is 1 mol% or less. By making the stearic acid content 1 mol% or less, a silver salt of an organic acid having a low Dmin, high sensitivity and excellent image storage stability can be obtained. As said stearic acid content rate, 0.5 mol% or less is preferable and it is especially preferable not to contain substantially.

  Furthermore, when silver arachidate is included as the silver salt of the organic acid, the silver arachidate content is 6 mol% or less to obtain a low Dmin and an organic acid silver salt excellent in image storability. It is preferable at a point and it is still more preferable that it is 3 mol% or less.

2) Shape The shape of the organic silver salt that can be used in the present invention is not particularly limited, and may be any of a needle shape, a rod shape, a flat plate shape, and a flake shape.
In the present invention, scaly organic silver salts are preferred. In addition, short needle-shaped, rectangular parallelepiped, cubic or potato-shaped irregular particles having a major axis / uniaxial length ratio of less than 5 are also preferably used. These organic silver particles have a feature that the fog at the time of heat development is less than that of long needle-like particles in which the ratio of the length of the major axis to the uniaxial axis is 5 or more. In particular, particles having a major axis / uniaxial ratio of 3 or less are preferable because the mechanical stability of the coating film is improved. In the present specification, the scaly organic silver salt is defined as follows. The organic acid silver salt was observed with an electron microscope, and the shape of the organic acid silver salt particle was approximated to a rectangular parallelepiped. Then, the shorter numerical values a and b are calculated, and x is obtained as follows.
x = b / a

  In this way, x is obtained for about 200 particles, and when the average value x (average) is obtained, particles satisfying the relationship of x (average) ≧ 1.5 are defined as flakes. Preferably, 30 ≧ x (average) ≧ 1.5, more preferably 15 ≧ x (average) ≧ 1.5. Incidentally, the needle shape is 1 ≦ x (average) <1.5.

  In the flake shaped particle, a can be regarded as a thickness of a tabular particle having a main plane with b and c as sides. The average of a is preferably 0.01 μm or more and 0.3 μm or less, and more preferably 0.1 μm or more and 0.23 μm or less. The average c / b is preferably 1 or more and 9 or less, more preferably 1 or more and 6 or less, still more preferably 1 or more and 4 or less, and most preferably 1 or more and 3 or less.

By setting the equivalent sphere diameter to 0.05 μm or more and 1 μm or less, aggregation is hardly caused in the photosensitive material, and image storability is improved. The sphere equivalent diameter is preferably 0.1 μm or more and 1 μm or less. In the present invention, the method for measuring the equivalent sphere diameter is obtained by directly photographing a sample using an electron microscope and then image-processing the negative.
In the flake shaped particles, the spherical equivalent diameter / a of the particles is defined as the aspect ratio. The aspect ratio of the flake-like particles is preferably 1.1 or more and 30 or less, more preferably 1.1 or more and 15 or less, from the viewpoint of preventing aggregation in the photosensitive material and improving the image storage stability. .

  The particle size distribution of the organic silver salt is preferably monodispersed. Monodispersion is preferably 100% or less, more preferably 80% or less, and even more preferably 50% of the value obtained by dividing the standard deviation of the lengths of the short and long axes by the short and long axes. It is as follows. The method for measuring the shape of the organic silver salt can be determined from a transmission electron microscope image of the organic silver salt dispersion. As another method for measuring monodispersity, there is a method for obtaining the standard deviation of the volume weighted average diameter of the organic silver salt, and the percentage (variation coefficient) of the value divided by the volume weighted average diameter is preferably 100% or less, more Preferably it is 80% or less, More preferably, it is 50% or less. As a measuring method, for example, it is obtained from the particle size (volume weighted average diameter) obtained by irradiating an organic silver salt dispersed in a liquid with laser light and obtaining an autocorrelation function with respect to the temporal change of the fluctuation of the scattered light. Can do.

3) Preparation Known methods and the like can be applied to the production and dispersion method of organic acid silver used in the present invention. For example, the above-mentioned JP-A-10-62899, European Patent Publication No. 0803763A1, European Patent Publication No. 0968212A1, JP-A-11-349591, JP-A-2000-7683, JP-A-2000-72711, JP-A-2001-163889, 2001-163890, 2001-163825, 2001-33907, 2001-188313, 2001-83651, 2002-6442, 2002-49117, 2002-31870, 2002-107868 You can refer to the issue.

  In addition, when the photosensitive silver salt is allowed to coexist at the time of dispersion of the organic silver salt, the fog rises and the sensitivity is remarkably lowered. 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 preferably 1 mol% or less, more preferably 0.1 mol% or less with respect to 1 mol of the organic acid silver salt in the liquid. Further, it is more preferable that no positive photosensitive silver salt is added.

  In the present invention, it is possible to produce a photosensitive material by mixing an organic silver salt aqueous dispersion and a photosensitive silver salt aqueous dispersion, but the mixing ratio of the organic silver salt and the photosensitive silver salt can be selected according to the purpose. The ratio of the photosensitive silver salt to the organic silver salt is preferably in the range of 1 mol% to 30 mol%, more preferably 2 mol% to 20 mol%, particularly preferably 3 mol% to 15 mol%. Mixing two or more organic silver salt aqueous dispersions and two or more photosensitive silver salt aqueous dispersions when mixing is a method preferably used for adjusting photographic characteristics.

4) Addition amount Although the organic silver salt in the present invention can be used in a desired amount, the total coating silver amount including silver halide is preferably 0.1 g / m ² or more and 5.0 g / m ² or less, more preferably. It is 0.3 g / m ² or more and 3.0 g / m ² or less, more preferably 0.5 g / m ² or more and 2.0 g / m ² or less.
In particular, in order to improve image storability, the total coated silver amount is preferably 1.8 g / m ² or less, more preferably 1.6 g / m ² or less. If the preferred reducing agent in the present invention is used, a sufficient image density can be obtained even with such a low silver amount.

(Description of reducing agent)
The photothermographic material of the present invention preferably contains a heat developer which is a reducing agent for the organic silver salt. The reducing agent for the organic silver salt may be any substance (preferably an organic substance) that reduces silver ions to metallic silver. Examples of such reducing agents are described in JP-A No. 11-65021, paragraphs 0043 to 0045, and European Patent Publication No. 0803764A1, page 7, line 34 to page 18, line 12.
In the present invention, the reducing agent is preferably a so-called hindered phenol-based reducing agent or bisphenol-based reducing agent having a substituent at the ortho position of the phenolic hydroxyl group, and more preferably a compound represented by the following general formula (R).

In the general formula (R), R ¹¹ and R ¹¹ ′ each independently represents an alkyl group having 1 to 20 carbon atoms. R ¹² and R ¹² ′ each independently represent a hydrogen atom or a substituent that can be substituted on a benzene ring. L represents a —S— group or a —CHR ¹³ — group. R ¹³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. X ¹ and X ¹ ′ each independently represent a hydrogen atom or a group that can be substituted on a benzene ring.

The general formula (R) will be described in detail.
When referred to as an alkyl group in the following, a cycloalkyl group is also included in this unless otherwise specified.
1) R ¹¹ and R ¹¹ '
R ¹¹ and R ¹¹ ′ are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. The substituent of the alkyl group is not particularly limited, but preferably an aryl group, a hydroxy group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acylamino group, a sulfonamido group, a sulfonyl group, a phosphoryl group, Examples thereof include an acyl group, a carbamoyl group, an ester group, a ureido group, a urethane group, and a halogen atom.

2) R ¹² and R ¹² ', X ¹ and X ¹ '
R ¹² and R ¹² ′ each independently represent a hydrogen atom or a substituent that can be substituted on a benzene ring, and X ¹ and X ¹ ′ each independently represent a hydrogen atom or a group that can be substituted on a benzene ring. Preferred examples of the group that can be substituted on the benzene ring include an alkyl group, an aryl group, a halogen atom, an alkoxy group, and an acylamino group.

3) L
L represents an —S— group or a —CHR ¹³ — group. R ¹³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and the alkyl group may have a substituent. Specific examples of the unsubstituted alkyl group of R ¹³ are methyl group, ethyl group, propyl group, butyl group, heptyl group, undecyl group, isopropyl group, 1-ethylpentyl group, 2,4,4-trimethylpentyl group, cyclohexyl. Group, 2,4-dimethyl-3-cyclohexenyl group, 3,5-dimethyl-3-cyclohexenyl group and the like. Examples of the substituent of the alkyl group are the same as the substituent of R ¹¹ , and are a halogen atom, alkoxy group, alkylthio group, aryloxy group, arylthio group, acylamino group, sulfonamido group, sulfonyl group, phosphoryl group, oxycarbonyl group, A carbamoyl group, a sulfamoyl group, etc. are mentioned.

4) Preferred substituents R ¹¹ and R ¹¹ ′ are preferably primary, secondary or tertiary alkyl groups having 1 to 15 carbon atoms, specifically methyl, isopropyl, t-butyl, t -Amyl group, t-octyl group, cyclohexyl group, cyclopentyl group, 1-methylcyclohexyl group, 1-methylcyclopropyl group and the like can be mentioned. R ¹¹ and R ¹¹ ′ are more preferably an alkyl group having 1 to 4 carbon atoms, and among them, a methyl group, a t-butyl group, a t-amyl group, or a 1-methylcyclohexyl group is more preferable, and a methyl group, t- A butyl group is most preferred.

R ¹² and R ¹² ′ are preferably an alkyl group having 1 to 20 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a t-butyl group, a t-amyl group, a cyclohexyl group. Group, 1-methylcyclohexyl group, benzyl group, methoxymethyl group, methoxyethyl group and the like. More preferred are a methyl group, an ethyl group, a propyl group, an isopropyl group, or a t-butyl group, and particularly preferred are a methyl group and an ethyl group.
X ¹ and X ¹ ′ are preferably a hydrogen atom, a halogen atom or an alkyl group, and more preferably a hydrogen atom.

L is preferably a —CHR ¹³ — group.
R ¹³ is preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. As the alkyl group, a cyclic alkyl group is also preferably used in addition to a chain alkyl group. Moreover, what has a C = C bond in these alkyl groups can also be used preferably. Examples of the alkyl group include a methyl group, ethyl group, propyl group, isopropyl group, 2,4,4-trimethylpentyl group, cyclohexyl group, 2,4-dimethyl-3-cyclohexenyl group, or 3,5-dimethyl-3. -A cyclohexenyl group and the like are preferable. R ¹³ is particularly preferably a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, or a 2,4-dimethyl-3-cyclohexenyl group.

When R ¹¹ and R ¹¹ ′ are tertiary alkyl groups and R ¹² and R ¹² ′ are methyl groups, R ¹³ is a primary or secondary alkyl group having 1 to 8 carbon atoms (methyl group, ethyl group, propyl group). Group, isopropyl group, or 2,4-dimethyl-3-cyclohexenyl group).
When R ¹¹ and R ¹¹ ′ are tertiary alkyl groups and R ¹² and R ¹² ′ are alkyl groups other than methyl groups, R ¹³ is preferably a hydrogen atom.
When R ¹¹ and R ¹¹ ′ are not a tertiary alkyl group, R ¹³ is preferably a hydrogen atom or a secondary alkyl group, and particularly preferably a secondary alkyl group. Preferred groups as the secondary alkyl group for R ¹³ are isopropyl group and 2,4-dimethyl-3-cyclohexenyl group.
The reducing agent has different heat developability, developed silver color tone and the like depending on the combination of R ¹¹ , R ¹¹ ′, R ¹² , R ¹² ′ and R ¹³ . Since these can be prepared by combining two or more reducing agents, it is preferable to use two or more in combination depending on the purpose.

  Although the specific example of the reducing agent in this invention including the compound represented by general formula (R) below is shown, this invention is not limited to these.

Examples of preferable reducing agents in the present invention other than the above are the compounds described in JP-A Nos. 2001-188314, 2001-209145, 2001-350235, 2002-156727, and EP1278101A2.
In the present invention, the addition amount of the reducing agent is preferably 0.1 g / m ² or more and 3.0 g / m ² or less, more preferably 0.2 g / m ² or more and 2.0 g / m ² or less, and still more preferably. Is 0.3 g / m ² or more and 1.0 g / m ² or less. 5 mol% or more and 50 mol% or less is preferably contained with respect to 1 mol of silver on the surface having the image forming layer, more preferably 8 mol% or more and 30 mol% or less, and 10 mol% or more and 20 mol% or less. More preferably, it is contained. 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, or a solid fine particle dispersion form, and may be contained in the photosensitive material.
Well-known emulsification and dispersion methods include oils such as dibutyl phthalate, tricresyl phosphate, dioctyl sebacate or tri (2-ethylhexyl) phosphate, and dissolution using an auxiliary solvent such as ethyl acetate or cyclohexanone, and dodecylbenzene. Examples thereof include a method of mechanically preparing an emulsified dispersion by adding a surfactant such as sodium sulfonate, oleoyl-N-methyl taurate, sodium di (2-ethylhexyl) sulfosuccinate. At this time, it is also preferable to add a polymer such as α-methylstyrene oligomer or poly (t-butylacrylamide) for the purpose of adjusting the viscosity and refractive index of the oil droplets.

Further, as a solid fine particle dispersion method, a reducing agent powder is dispersed in an appropriate solvent such as water by a ball mill, a colloid mill, a vibration ball mill, a sand mill, a jet mill, a roller mill, or an ultrasonic wave to produce a solid dispersion. A method is mentioned. In this case, a protective colloid (for example, polyvinyl alcohol) or 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. In the mills, beads such as zirconia are usually used as a dispersion medium, and Zr and the like eluted from these beads may be mixed in the dispersion. Although it depends on the dispersion conditions, it is usually in the range of 1 ppm to 1000 ppm. If the content of Zr in the light-sensitive material is 0.5 mg or less per 1 g of silver, there is no practical problem.
The aqueous dispersion preferably contains a preservative (for example, benzoisothiazolinone sodium salt).
Particularly preferred is a solid particle dispersion method of a reducing agent, in which fine particles having an average particle size of 0.01 μm to 10 μm, preferably 0.05 μm to 5 μm, more preferably 0.1 μm to 2 μm are added. Is preferred. In the present application, it is preferable to use other solid dispersions dispersed in a particle size within this range.

(Description of development accelerator)
In the photothermographic material of the present invention, a sulfonamide phenol compound represented by the general formula (A) described in JP-A-2000-267222, JP-A-2000-330234, or the like as a development accelerator, Hindered phenol compounds represented by general formula (II) described in JP-A No. 2001-92075, general formula (I) described in JP-A Nos. 10-62895 and 11-15116, A hydrazine-based compound represented by the general formula (D) of JP-A No. 2002-156727 or the general formula (1) described in JP-A No. 2002-278017, and described in the specification of JP-A No. 2001-264929 Phenol-based or naphthol-based compounds represented by the general formula (2) are preferably used. Moreover, the phenol type compound described in Unexamined-Japanese-Patent No. 2002-311533 and Unexamined-Japanese-Patent No. 2002-341484 is also preferable. In particular, naphthol compounds described in JP-A No. 2003-66558 are preferable. These development accelerators are used in the range of 0.1 mol% or more and 20 mol% or less, preferably 0.5 mol% or more and 10 mol% or less, more preferably 1 mol% or more with respect to the reducing agent. The range is 5 mol% or less. The introduction method to the light-sensitive material includes the same method as the reducing agent, but it is particularly preferable to add as a solid dispersion or an emulsified dispersion. When added as an emulsified dispersion, it is added as an emulsified dispersion dispersed using a high-boiling solvent and a low-boiling auxiliary solvent that are solid at room temperature, or as a so-called oilless emulsified dispersion that does not use a high-boiling solvent. It is preferable to add.
In the present invention, among the above development accelerators, hydrazine compounds described in JP-A Nos. 2002-156727 and 2002-278017 and naphthol compounds described in JP-A No. 2003-66558 are used. Is more preferable.

Particularly preferred development accelerators in the invention are compounds represented by the following general formulas (A-1) and (A-2).
Formula (A-1)
Q ₁ -NHNH-Q ₂
In the formula, Q ₁ represents an aromatic group or a heterocyclic group bonded to —NHNH—Q ₂ at a carbon atom, and Q ₂ represents a carbamoyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfonyl group, or Represents a sulfamoyl group.

In the general formula (A-1), the aromatic group or heterocyclic group represented by Q ₁ is preferably a 5- to 7-membered unsaturated ring. Preferred examples include benzene ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, 1,2,4-triazine ring, 1,3,5-triazine ring, pyrrole ring, imidazole ring, pyrazole ring, 1,2 , 3-triazole ring, 1,2,4-triazole ring, tetrazole ring, 1,3,4-thiadiazole ring, 1,2,4-thiadiazole ring, 1,2,5-thiadiazole ring, 1,3,4 -Oxadiazole ring, 1,2,4-oxadiazole ring, 1,2,5-oxadiazole ring, thiazole ring, oxazole ring, isothiazole ring, isoxazole ring, thiophene ring, etc. are preferable, and these Also preferred are fused rings in which the rings are fused together.

  These rings may have a substituent, and when they have two or more substituents, these substituents may be the same or different. Examples of substituents include halogen atoms, alkyl groups, aryl groups, carbonamido groups, alkylsulfonamido groups, arylsulfonamido groups, alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, carbamoyl groups, sulfamoyl groups, cyano Groups, alkylsulfonyl groups, arylsulfonyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, and acyl groups. When these substituents are substitutable groups, they may further have substituents. Examples of preferred substituents include halogen atoms, alkyl groups, aryl groups, carbonamido groups, alkylsulfonamido groups, aryls. Sulfonamide group, alkoxy group, aryloxy group, alkylthio group, arylthio group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, cyano group, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, and acyloxy group Can be mentioned.

The carbamoyl group represented by Q ₂ is preferably a carbamoyl group having 1 to 50 carbon atoms, more preferably 6 to 40 carbon atoms. For example, unsubstituted carbamoyl, methylcarbamoyl, N-ethylcarbamoyl, N-propylcarbamoyl N-sec-butylcarbamoyl, N-octylcarbamoyl, N-cyclohexylcarbamoyl, N-tert-butylcarbamoyl, N-dodecylcarbamoyl, N- (3-dodecyloxypropyl) carbamoyl, N-octadecylcarbamoyl, N- {3 -(2,4-tert-pentylphenoxy) propyl} carbamoyl, N- (2-hexyldecyl) carbamoyl, N-phenylcarbamoyl, N- (4-dodecyloxyphenyl) carbamoyl, N- (2-chloro-5 Dodecyloxycarbo Butylphenyl) carbamoyl, N- naphthylcarbamoyl, N-3- pyridylcarbamoyl include N- benzylcarbamoyl.

The acyl group represented by Q ₂ is preferably an acyl group having 1 to 50 carbon atoms, more preferably 6 to 40 carbon atoms, such as formyl, acetyl, 2-methylpropanoyl, cyclohexylcarbonyl, octanoyl, 2 -Hexyldecanoyl, dodecanoyl, chloroacetyl, trifluoroacetyl, benzoyl, 4-dodecyloxybenzoyl, 2-hydroxymethylbenzoyl. The alkoxycarbonyl group represented by Q ₂ is preferably an alkoxycarbonyl group having 2 to 50 carbon atoms, more preferably 6 to 40 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, isobutyloxycarbonyl, cyclohexyloxycarbonyl, Examples include dodecyloxycarbonyl and benzyloxycarbonyl.

The aryloxycarbonyl group represented by Q ₂ is preferably an aryloxycarbonyl group having 7 to 50 carbon atoms, more preferably 7 to 40 carbon atoms, such as phenoxycarbonyl, 4-octyloxyphenoxycarbonyl, 2-hydroxy Examples thereof include methylphenoxycarbonyl and 4-dodecyloxyphenoxycarbonyl. The sulfonyl group represented by Q ₂ is preferably a sulfonyl group having 1 to 50 carbon atoms, more preferably 6 to 40 carbon atoms, such as methylsulfonyl, butylsulfonyl, octylsulfonyl, 2-hexadecylsulfonyl, 3- Examples include dodecyloxypropylsulfonyl, 2-octyloxy-5-tert-octylphenylsulfonyl, and 4-dodecyloxyphenylsulfonyl.

The sulfamoyl group represented by Q ₂ is preferably a sulfamoyl group having 0 to 50 carbon atoms, more preferably 6 to 40 carbon atoms, such as an unsubstituted sulfamoyl group, an N-ethylsulfamoyl group, N- (2- Ethylhexyl) sulfamoyl, N-decylsulfamoyl, N-hexadecylsulfamoyl, N- {3- (2-ethylhexyloxy) propyl} sulfamoyl, N- (2-chloro-5-dodecyloxycarbonylphenyl) sulfamoyl, N- (2-tetradecyloxyphenyl) sulfamoyl is mentioned. The group represented by Q ₂ may further have a group listed as an example of the substituent of the 5-membered to 7-membered unsaturated ring represented by Q ₁ at a substitutable position, When it has two or more substituents, these substituents may be the same or different.

Next, preferred range for the compound represented by formula (A-1) is to be described. Q ₁ is preferably a 5- to 6-membered unsaturated ring, such as a benzene ring, pyrimidine ring, 1,2,3-triazole ring, 1,2,4-triazole ring, tetrazole ring, 1,3,4-thiadiazole. Ring, 1,2,4-thiadiazole ring, 1,3,4-oxadiazole ring, 1,2,4-oxadiazole ring, thiazole ring, oxazole ring, isothiazole ring, isoxazole ring, and these More preferred are rings in which the ring is fused with a benzene ring or an unsaturated heterocycle. Q ₂ is preferably a carbamoyl group, particularly preferably a carbamoyl group having a hydrogen atom on a nitrogen atom.

In the general formula (A-2), R ₁ represents an alkyl group, an acyl group, an acylamino group, a sulfonamide group, an alkoxycarbonyl group, or a carbamoyl group. R ₂ represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyloxy group, or a carbonate ester group. R ₃ and R ₄ each represents a group that can be substituted on the benzene ring mentioned in the example of the substituent of formula (A-1). R ₃ and R ₄ may be connected to each other to form a condensed ring.
R ₁ is preferably an alkyl group having 1 to 20 carbon atoms (for example, a methyl group, an ethyl group, an isopropyl group, a butyl group, a tert-octyl group, a cyclohexyl group, etc.), an acylamino group (for example, an acetylamino group, a benzoylamino group, a methyl group). Ureido group, 4-cyanophenylureido group, etc.), carbamoyl group (n-butylcarbamoyl group, N, N-diethylcarbamoyl group, phenylcarbamoyl group, 2-chlorophenylcarbamoyl group, 2,4-dichlorophenylcarbamoyl group, etc.) acylamino Groups (including ureido groups and urethane groups) are more preferred. R ₂ is preferably a halogen atom (more preferably a chlorine atom or a bromine atom), an alkoxy group (for example, methoxy group, butoxy group, n-hexyloxy group, n-decyloxy group, cyclohexyloxy group, benzyloxy group, etc.), aryl An oxy group (phenoxy group, naphthoxy group, etc.).
R ₃ is preferably a hydrogen atom, a halogen atom, or an alkyl group having 1 to 20 carbon atoms, and most preferably a halogen atom. R ₄ is preferably a hydrogen atom, an alkyl group or an acylamino group, more preferably an alkyl group or an acylamino group. Examples of these preferable substituents are the same as those for R ₁ . When R ₄ is an acylamino group, R ₄ is preferably linked to R ₃ to form a carbostyryl ring.

In the general formula (A-2), when R ₃ and R ₄ are connected to each other to form a condensed ring, a naphthalene ring is particularly preferable as the condensed ring. The same substituent as the example of a substituent quoted by general formula (A-1) may couple | bond with the naphthalene ring. When general formula (A-2) is a naphthol-based compound, R ₁ is preferably a carbamoyl group. Of these, a benzoyl group is particularly preferable. R ₂ is preferably an alkoxy group or an aryloxy group, and particularly preferably an alkoxy group.

  Hereinafter, preferred specific examples of the development accelerator in the present invention will be given. The present invention is not limited to these.

(Description of hydrogen bonding compounds)
When the reducing agent in the present invention has an aromatic hydroxyl group (—OH) or amino group (—NHR, R is a hydrogen atom or an alkyl group), particularly in the case of the aforementioned bisphenols, these groups and hydrogen bonds It is preferable to use together a non-reducing compound having a group capable of forming.
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, a urethane group, a ureido group, a tertiary amino group, and a nitrogen-containing aromatic group. Can be mentioned. Among them, preferred are a phosphoryl group, a sulfoxide group, an amide group (however, it has no> N—H group and is blocked like> N—Ra (Ra is a substituent other than H)), a urethane group. (However, it has no> N—H group and is blocked like> N—Ra (Ra is a substituent other than H)), a ureido group (however, it has no> N—H group,> N-Ra (Ra 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 (D).

In the general formula (D), R ²¹ to R ²³ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group or a heterocyclic group, and these groups may be substituted even if they are unsubstituted. You may have.
When R ²¹ to R ²³ 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, Examples thereof include an oxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, and a phosphoryl group. Preferred examples of the substituent include an alkyl group or an aryl group such as a methyl group, an ethyl group, an isopropyl group, a t-butyl group, a t-butyl group. Examples include an octyl group, a phenyl group, a 4-alkoxyphenyl group, and a 4-acyloxyphenyl group.
Specific examples of the alkyl group represented by R ²¹ to R ²³ include a methyl group, an ethyl group, a butyl group, an octyl group, a dodecyl group, an isopropyl group, a t-butyl group, a t-amyl group, a t-octyl group, a cyclohexyl group, Examples include 1-methylcyclohexyl group, benzyl group, phenethyl group, and 2-phenoxypropyl group.
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, and a 3,5-dichlorophenyl group.
Alkoxy groups include methoxy, ethoxy, butoxy, octyloxy, 2-ethylhexyloxy, 3,5,5-trimethylhexyloxy, dodecyloxy, cyclohexyloxy, 4-methylcyclohexyloxy, and A benzyloxy group etc. are mentioned.
Examples of the aryloxy group include a phenoxy group, a cresyloxy group, an isopropylphenoxy group, a 4-t-butylphenoxy group, a naphthoxy group, and a biphenyloxy group.
Examples of the amino group include 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 an N-methyl-N-phenylamino group. It is done.

R ²¹ to R ²³ are preferably an alkyl group, an aryl group, an alkoxy group, or an aryloxy group. In view of the effects of the present invention, at least one of R ²¹ to R ²³ is preferably an alkyl group or an aryl group, and more preferably two or more are an alkyl group or an aryl group. Further, it is preferable that R ²¹ to R ²³ are the same group in that they can be obtained at low cost.
Specific examples of the hydrogen bonding compound including the compound of the general formula (D) in the present invention are shown below, but the present invention is not limited thereto.

Specific examples of the hydrogen bonding compound include those described in European Patent No. 1096310, JP-A No. 2002-156727, and JP-A No. 2002-318431 in addition to the above.
The compound of the general formula (D) in the present invention can be used in a light-sensitive material by being incorporated in a coating solution in the form of a solution, an emulsified dispersion, or a solid dispersion fine particle dispersion in the same manner as the reducing agent. It is preferable to use it as a product. These compounds form a hydrogen-bonding complex with a compound having a phenolic hydroxyl group or an amino group in a solution state. It can be isolated in the state.
The use of the crystal powder isolated in this way as a solid dispersed fine particle dispersion is particularly preferable for obtaining stable performance. Further, a method in which the reducing agent and the compound of the general formula (D) in the present invention are mixed in a powder and complexed at the time of dispersion with a sand grinder mill or the like using an appropriate dispersant can be preferably used.
The compound of the general formula (D) in the present invention is preferably used in the range of 1 mol% to 200 mol%, more preferably in the range of 10 mol% to 150 mol%, based on the reducing agent. More preferably, it is the range of 20 mol% or more and 100 mol%.

(Image forming layer binder)
Any polymer may be used as the binder of the image-forming layer in the present invention. Suitable binders are transparent or translucent and generally colorless, and are natural resins, polymers and copolymers, synthetic resins, polymers and copolymers, and other films. Forming media such as gelatins, gums, poly (vinyl alcohol) s, hydroxyethyl celluloses, cellulose acetates, cellulose acetate butyrates, poly (vinyl pyrrolidone) s, casein, starch, poly (acrylic acid) , Poly (methyl methacrylic acid) s, 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 acetal) (Formal) and poly (vinyl butyral)), poly (esters), poly (urethane) s, phenoxy resins, poly (vinylidene chloride) s, poly (epoxides), poly (carbonates), poly (vinyl acetate) s , Poly (olefin) s, cellulose esters, and poly (amides). The binder may be formed from water, an organic solvent or an emulsion.

  In the present invention, the glass transition temperature of the binder that can be used in combination with the layer containing the organic silver salt is preferably 0 ° C. or higher and 80 ° C. or lower (hereinafter sometimes referred to as a high Tg binder), and preferably 10 ° C. to 70 ° C. Is more preferable, and it is still more preferable that it is 15 degreeC or more and 60 degrees C or less.

  Two or more binders may be used in combination as required. Further, a glass transition temperature of 20 ° C. or higher and a glass transition temperature of less than 20 ° C. may be used in combination. When two or more types of polymers having different Tg are blended, the mass average Tg is preferably within the above range.

In the present invention, it is preferable that the image forming layer is coated and dried using a coating solution in which 30% by mass or more of the solvent is water to form a film.
In the present invention, when the image forming layer is formed using a coating solution in which 30% by mass or more of the solvent is water and dried, the binder of the image forming layer is further added to an aqueous solvent (aqueous solvent). When it is soluble or dispersible, the performance is improved particularly when it is made of a latex of a polymer having an equilibrium water content of 2 mass% or less at 25 ° C. and 60% RH. The most preferable form is one prepared so that the ionic conductivity is 2.5 mS / cm or less, and as such a preparation method, there is a method of purifying using a separation functional membrane after polymer synthesis.

  The aqueous solvent in which the polymer is soluble or dispersible here is a mixture of water or 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, cellosolvs such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve, ethyl acetate, and dimethylformamide.

  The equilibrium water content at 25 ° C. and 60% RH of the binder polymer in the present invention is preferably 2% by mass or less, more preferably 0.01% by mass or more and 1.5% by mass or less, and still more preferably 0.02%. Desirably, the content is from 1% by mass to 1% by mass.

  In the present invention, a polymer dispersible in an aqueous solvent is particularly preferred. Examples of the dispersed state may be either latex in which fine particles of water-insoluble hydrophobic polymer are dispersed or polymer molecules dispersed in a molecular state or forming micelles. preferable. The average particle size of the dispersed particles is 1 nm or more and 50000 nm or less, preferably 5 nm or more and 1000 nm or less, more preferably 10 nm or more and 500 nm or less, and further preferably 50 nm or more and 200 nm or less. 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. Mixing two or more types having a monodispersed particle size distribution is also a preferable method for controlling the physical properties of the coating solution.

  In the present invention, preferred embodiments of the polymer that can be dispersed in an aqueous solvent include acrylic polymers, poly (esters), rubbers (eg, SBR resin), poly (urethanes), poly (vinyl chloride) s, poly (acetic acid). Hydrophobic polymers such as vinyl), poly (vinylidene chloride) and poly (olefin) can be preferably used. These polymers may be linear polymers, branched polymers, crosslinked polymers, so-called homopolymers obtained by polymerizing a single monomer, or copolymers obtained by polymerizing two or more types of monomers. In the case of a copolymer, it may be a random copolymer or a block copolymer. The molecular weight of these polymers is 5,000 to 1,000,000, preferably 10,000 to 200,000 in terms of number average molecular weight. When the molecular weight is too small, the mechanical strength of the image forming layer is insufficient, and when the molecular weight is too large, the film formability is poor, which is not preferable. A crosslinkable polymer latex is particularly preferably used.

(Specific examples of latex)
Specific examples of the preferred polymer latex include the following. Below, it represents using a raw material monomer, the numerical value in a parenthesis is the mass%, and molecular weight is a number average molecular weight. When a polyfunctional monomer was used, the concept of molecular weight was not applicable because a crosslinked structure was formed, so it was described as crosslinkable and the molecular weight description was omitted. Tg represents the glass transition temperature.

-P-1; latex of -MMA (70) -EA (27) -MAA (3)-(molecular weight 37000, Tg 61 ° C.)
-Latex of P-2; -MMA (70) -2EHA (20) -St (5) -AA (5)-(molecular weight 40000, Tg 59 ° C.)
-P-3; Latex of -St (50) -Bu (47) -MAA (3)-(crosslinkability, Tg-17 ° C)
-P-4; Latex of -St (68) -Bu (29) -AA (3)-(crosslinkability, Tg 17 ° C)
-P-5; Latex of -St (71) -Bu (26) -AA (3)-(crosslinkability, Tg 24 ° C)
-P-6; -St (70) -Bu (27) -IA (3)-latex (crosslinkable)
-P-7; Latex of -St (75) -Bu (24) -AA (1)-(crosslinkability, Tg 29 ° C.)
-P-8; Latex (crosslinkability) of -St (60) -Bu (35) -DVB (3) -MAA (2)-
-Latex (crosslinkable) of P-9; -St (70) -Bu (25) -DVB (2) -AA (3)-
-Latex (molecular weight 80000) of P-10; -VC (50) -MMA (20) -EA (20) -AN (5) -AA (5)-
-Latex of P-11; -VDC (85) -MMA (5) -EA (5) -MAA (5)-(molecular weight 67000)
-P-12; -Et (90) -MAA (10)-latex (molecular weight 12000)
-P-13; -St (70) -2EHA (27) -AA (3) latex (molecular weight 130000, Tg 43 ° C)
-P-14; -MMA (63) -EA (35) -AA (2) latex (molecular weight 33000, Tg 47 ° C.)
-P-15; Latex of -St (70.5) -Bu (26.5) -AA (3)-(crosslinkability, Tg 23 ° C.)
-P-16; Latex of -St (69.5) -Bu (27.5) -AA (3)-(crosslinkability, Tg 20.5 ° C)
・ P-17; Latex of -St (61.3) -isoprene (35.5) -AA (3)-(crosslinkability, Tg17 ° C)
・ P-18; -St (67) -Isoprene (28) -Bu (2) -AA (3)-

  The abbreviations for the above structures represent the following monomers. MMA; Methyl methacrylate, EA; Ethyl acrylate, MAA; Methacrylic acid, 2EHA; 2-Ethylhexyl acrylate, St; Styrene, Bu; Butadiene, AA; Acrylic acid, DVB; Divinylbenzene, VC; Vinyl chloride, AN; Acrylonitrile, VDC Vinylidene chloride, Et; ethylene, IA; itaconic acid.

  The polymer latex described above is also commercially available, and the following polymers can be used. Examples of the acrylic polymer include Sebian A-4635, 4718, 4601 (manufactured by Daicel Chemical Industries, Ltd.), Nipol Lx811, 814, 821, 820, 857 (manufactured by Nippon Zeon Co., Ltd.), etc. Examples of poly (esters) include poly (urethane) such as FINETEX ES650, 611, 675, 850 (above, manufactured by Dainippon Ink Chemical Co., Ltd.), WD-size, WMS (above, manufactured by Eastman Chemical). Examples of rubbers include HYDRAN AP10, 20, 30, 40 (manufactured by Dainippon Ink Chemical Co., Ltd.), and examples of rubbers include LACSTAR 7310K, 3307B, 4700H, 7132C (above, Dainippon Ink Chemical Co., Ltd.). (Made by Co., Ltd.), Nipol Lx416, 410, 438C, 2507 (above, Nippon Zeo) As examples of poly (vinyl chloride) such as G351 and G576 (above, manufactured by Nippon Zeon Co., Ltd.), examples of poly (vinylidene chloride) such as L502, L513 (above Examples of poly (olefin) s such as Asahi Kasei Kogyo Co., Ltd. include Chemipearl S120 and SA100 (above Mitsui Petrochemical Co., Ltd.).

  These polymer latexes may be used alone or in combination of two or more as required.

(Preferred latex)
As the polymer latex used in the present invention, a styrene-butadiene copolymer latex is particularly preferable. The mass ratio of the styrene monomer unit to the butadiene monomer unit in the styrene-butadiene copolymer is preferably 40:60 to 95: 5. The proportion of the styrene monomer unit and the butadiene monomer unit in the copolymer is preferably 60% by mass to 99% by mass. Moreover, it is preferable that the polymer latex in this invention contains acrylic acid or methacrylic acid 1 mass%-6 mass% with respect to the sum of styrene and butadiene, More preferably, it contains 2 mass%-5 mass%. The polymer latex in the present invention preferably contains acrylic acid. The preferred molecular weight range is the same as described above.

  Examples of latexes of styrene-butadiene acid copolymer that are preferably used in the present invention include the above-mentioned P-3 to P-8,15, commercially available products LACSTAR-3307B, 7132C, Nipol Lx416, and the like.

  The organic silver salt-containing layer (that is, the image forming layer) in the present invention is preferably formed using a polymer latex. The amount of binder in the image forming layer is such that the total binder / organic silver salt mass ratio is 1/10 to 10/1, more preferably 1/3 to 5/1, and still more preferably 1/1 to 3/1. Range.

  In addition, such an organic silver salt-containing layer is usually an image forming layer (image forming layer) containing a photosensitive silver halide that is a photosensitive silver salt. The mass ratio of silver halide is 400-5, more preferably 200-10.

The total binder amount of the image forming layer in the present invention is preferably 0.2 g / m ² or more and 30 g / m ² or less, more preferably 1 g / m ² or more and 15 g / m ² or less, and further preferably 2 g / m ² or more and 10 g. / M ² or less. In the image forming layer of the present invention, a crosslinking agent for crosslinking, a surfactant for improving coating properties, and the like may be added.

(Preferable solvent for coating solution)
In the present invention, the solvent of the image forming layer coating solution of the light-sensitive material (here, for simplicity, the solvent and the dispersion medium are collectively referred to as a solvent) is preferably an aqueous solvent containing 30% by mass or more of water. 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 of the coating solution is preferably 50% by mass or more, more preferably 70% by mass or more. Examples of preferred solvent compositions include water, water / methyl alcohol = 90/10, water / methyl alcohol = 70/30, water / methyl alcohol / dimethylformamide = 80/15/5, water / methyl alcohol / There are ethyl cellosolve = 85/10/5, water / methyl alcohol / isopropyl alcohol = 85/10/5, etc. (numerical value is mass%).

  If necessary, a hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose, carboxymethylcellulose may be added to the image forming layer of the light-sensitive material of the present invention. The amount of these hydrophilic polymers added is preferably 30% by mass or less, more preferably 20% by mass or less, based on the total binder of the image forming layer.

  The organic silver salt-containing layer (that is, the image forming layer) in the present invention is preferably formed using a polymer latex. The amount of binder in the image forming layer is such that the total binder / organic silver salt mass ratio is 1/10 to 10/1, more preferably 1/3 to 5/1, and still more preferably 1/1 to 3/1. Range.

  In addition, such an organic silver salt-containing layer is usually an image forming layer (image forming layer) containing a photosensitive silver halide that is a photosensitive silver salt. The mass ratio of silver halide is 400-5, more preferably 200-10.

The total binder amount of the image forming layer in the present invention is preferably 0.2 g / m ² or more and 30 g / m ² or less, more preferably 1 g / m ² or more and 15 g / m ² or less, and further preferably 2 g / m ² or more and 10 g. / M ² or less. In the image forming layer of the present invention, a crosslinking agent for crosslinking, a surfactant for improving coating properties, and the like may be added.

(Description of silver halide)
1) Halogen composition The photosensitive silver halide used in the present invention is not particularly limited as a halogen composition, and is silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver iodochlorobromide, silver iodide. Can be used. Of these, silver bromide, silver iodobromide and silver iodide are preferred. The distribution of the halogen composition in the grain may be uniform, the halogen composition may be changed stepwise, or may be continuously changed. Further, silver halide grains having a core / shell structure can be preferably used. A preferable structure is a 2- to 5-fold structure, and more preferably 2- to 4-fold core / shell particles can be used. A technique for localizing silver bromide or silver iodide on the surface of silver chloride, silver bromide or silver chlorobromide grains can also be preferably used.

2) Grain Forming Methods Methods for forming photosensitive silver halide are well known in the art and are described, for example, in Research Disclosure No. 17029, June 1978, and US Pat. No. 3,700,458. In particular, a photosensitive silver halide is prepared by adding a silver supply compound and a halogen supply compound in gelatin or other polymer solution, and then mixed with an organic silver salt. Use the method. Further, the method described in paragraph Nos. 0217 to 0224 of JP-A No. 11-119374, and the methods described in JP-A Nos. 11-352627 and 2000-347335 are also preferable.

3) Grain size The grain size of the photosensitive silver halide is preferably small for the purpose of reducing the cloudiness after image formation, specifically 0.20 μm or less, more preferably 0.01 μm or more and 0.15 μm or less. More preferably, it is 0.02 μm or more and 0.12 μm or less. The grain size here means the diameter when converted into a circular image having the same area as the projected area of silver halide grains (in the case of tabular grains, the projected area of the main plane).

4) Grain shape Examples of the shape of silver halide grains include cubes, octahedrons, tabular grains, spherical grains, rod-like grains, and potato grains. In the present invention, cubic grains are particularly preferred. Grains with rounded corners of silver halide grains can also be preferably used. The surface index (Miller index) of the outer surface of the photosensitive silver halide grain is not particularly limited, but the ratio of the {100} plane having high spectral sensitization efficiency when the spectral sensitizing dye is adsorbed is high. preferable. The ratio is preferably 50% or more, more preferably 65% or more, and still more preferably 80% or more. The ratio of the Miller index {100} plane is determined by T.T. Tani; Imaging Sci. 29, 165 (1985).

5) Heavy Metal The photosensitive silver halide grain of the present invention can contain a metal or metal complex of Group 8 to Group 13 of the Periodic Table (showing Groups 1 to 18). More preferably, a metal or metal complex of Group 8 to Group 10 can be contained. As the central metal of the group 8 to group 10 metal or metal complex of the periodic table, rhodium, ruthenium, iridium, and iron are preferable. 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 with ^respect to 1 mol of silver. These heavy metals and metal complexes and methods for adding them are described in JP-A-7-225449, JP-A-11-65021, paragraphs 0018 to 0024, and JP-A-11-119374, paragraphs 0227 to 0240.

In the present invention, silver halide grains in which a hexacyano metal complex is present on the outermost surface of the grains are preferred. The 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 (CN) ₆ ] ³⁻ , [Ir (CN) ₆ ] ³⁻ , [Cr (CN) ₆ ] ³⁻ , and [Re (CN) ₆ ] ^3−. It is done. In the present invention, a hexacyano Fe complex is preferred.

  The hexacyano metal complex is present in the form of ions in aqueous solution, so the counter cation is not important, but it is easy to mix with water and is suitable for precipitation of silver halide emulsions. Sodium ion, potassium ion, rubidium It is preferable to use alkali metal ions such as ions, cesium ions, and lithium ions, ammonium ions, and alkylammonium ions (for example, tetramethylammonium ions, tetraethylammonium ions, tetrapropylammonium ions, tetra (n-butyl) ammonium ions).

  In addition to water, the hexacyano metal complex is miscible with a mixed solvent or gelatin with an appropriate organic solvent miscible with water (for example, alcohols, ethers, glycols, ketones, esters, or amides). Can be added.

The addition amount of the hexacyano metal complex is preferably 1 × 10 ⁻⁵ mol or more and 1 × 10 ⁻² mol or less, more preferably 1 × 10 ⁻⁴ mol or more and 1 × 10 ⁻³ mol or less per mol of silver.

  In order for the hexacyano metal complex to be present on the outermost surface of the silver halide grain, the chalcogen sensitization of sulfur sensitization, selenium sensitization and tellurium sensitization is completed after the addition of the silver nitrate aqueous solution used for grain formation. It is added directly before the completion of the preparation step before the chemical sensitization step for performing noble metal sensitization such as sensitization and gold sensitization, during the washing step, during the dispersion step, or before the chemical sensitization step. In order to prevent the silver halide fine grains from growing, it is preferable to add the hexacyano metal complex immediately after the grain formation, and it is preferable to add it before the completion of the preparation step.

  The addition of the hexacyano metal complex may be started after adding 96% by mass of the total amount of silver nitrate to be added to form grains, more preferably starting after adding 98% by mass, The addition of 99% by mass is particularly preferable.

  When these hexacyanometal complexes are added after the addition of the aqueous silver nitrate solution just before the completion of grain formation, they can be adsorbed on the outermost surface of the silver halide grains, and most of them form slightly soluble salts with silver ions on the grain surface. To do. Since this silver salt of hexacyanoiron (II) is a less soluble salt than AgI, it is possible to prevent re-dissolution by fine particles and to produce silver halide fine particles having a small particle size. .

Further, regarding a metal atom (for example, [Fe (CN) ₆ ] ⁴⁻ ), a silver halide emulsion desalting method and a chemical sensitization method that can be contained in the silver halide grains used in the present invention, JP-A-11-11 No. 84574, paragraph numbers 0046 to 0050, JP-A No. 11-65021, paragraph numbers 0025 to 0031, and JP-A No. 11-119374, paragraph numbers 0242 to 0250.

6) Gelatin As the gelatin contained in the photosensitive silver halide emulsion used in the present invention, various gelatins can be used. It is necessary to maintain a good dispersion state of the photosensitive silver halide emulsion in the coating solution containing an organic silver salt, and gelatin having a molecular weight of 10,000 to 1,000,000 is preferably used. It is also preferable to phthalate the gelatin substituent. These 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 grain formation.

7) Sensitizing Dye Sensitizing dyes applicable to the present invention are those that can spectrally sensitize silver halide grains in a desired wavelength region when adsorbed on silver halide grains, and are suitable for the spectral characteristics of the exposure light source. Sensitizing dyes with sensitivity can be advantageously selected. Regarding the sensitizing dye and the addition method, paragraphs 0103 to 0109 of JP-A No. 11-65021, compounds represented by formula (II) of JP-A No. 10-186572, and formulas (I of JP-A No. 11-119374) ) And the dye described in Example 5 of U.S. Pat. Nos. 5,510,236 and 3,871,887, JP-A-2-96131, JP-A-59-48753. No. 19, page 38 to line 20, page 35 of European Patent Publication No. 0803764A1, JP 2001-272747, JP 2001-290238, JP 2002-23306, etc. It is described in. 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 the time from the desalting step to the coating, and more preferably the time from desalting to the end of chemical ripening.
The addition amount of the sensitizing dye in the present invention, can be a desired amount depending on the property of sensitivity and fogging, silver halide in the image forming layer 1 mole per 10 ^-6 to 1 mol are preferred, Preferably it is 10 < ^-4 > mol mol-10 < ^-1 > mol.

  In the present invention, a supersensitizer can be used to improve spectral sensitization efficiency. As the supersensitizer used in the present invention, European Patent Publication No. 587,338, US Pat. Nos. 3,877,943, 4,873,184, JP-A-5-341432, 11- 109547, 10-111543, etc. are mentioned.

8) Chemical Sensitization The photosensitive silver halide grain in the invention is preferably chemically sensitized by sulfur sensitizing method, selenium sensitizing method or tellurium sensitizing method. As compounds that are preferably used in the sulfur sensitization method, selenium sensitization method, and tellurium sensitization method, known compounds such as compounds described in JP-A-7-128768 can be used. In the present invention, tellurium sensitization is particularly preferred. The compounds described in the literature described in paragraph No. 0030 of JP-A-11-65021, and the general formulas (II), (III), (IV) described in JP-A-5-313284 The compound shown by is more preferable.

  The photosensitive silver halide grains in the present invention are preferably chemically sensitized by gold sensitization alone or in combination with the chalcogen sensitization described above. As the gold sensitizer, the valence of gold is preferably +1 or +3, and the gold sensitizer is preferably a commonly used gold compound. Typical examples are chloroauric acid, bromoauric acid, potassium chloroaurate, potassium bromoaurate, auric trichloride, potassium auric thiocyanate, potassium iodoaurate, tetracyanoauric acid, ammonium aurothiocyanate, pyridyltrichlorogold. Etc. are preferable. Further, gold sensitizers described in US Pat. No. 5,858,637 and JP-A No. 2002-278016 are also preferably used.

In the present invention, chemical sensitization can be performed at any time after particle formation and before coating. After desalting, (1) before spectral sensitization, (2) simultaneously with spectral sensitization, (3) spectral After sensitization, there may be (4) immediately before application.
The amount of sulfur, selenium and tellurium sensitizers used in the present invention varies depending on the silver halide grains used, chemical ripening conditions, etc., but from 10 ⁻⁸ mol to 10 ⁻² mol per mol of silver halide, Preferably, about 10 ⁻⁷ mol to 10 ⁻³ mol is used.
The amount of the gold sensitizer added varies depending on various conditions, but as a guideline, it is 10 ⁻⁷ mol or more and 10 ⁻³ mol or less, more preferably 10 ⁻⁶ mol or more and 5 × 10 ⁻⁴ mol or less per mol of silver halide. It is.
The conditions for chemical sensitization in the present invention are not particularly limited, but the pH is 5 to 8, the pAg is 6 to 11, and the temperature is about 40 ° C to 95 ° C.
A thiosulfonic acid compound may be added to the silver halide emulsion used in the present invention by the method described in European Patent Publication No. 293,917.

  A reducing agent is preferably used for the photosensitive silver halide grains in the present invention. As specific compounds for the reduction sensitization, ascorbic acid and aminoiminomethanesulfinic acid are preferable, and in addition, it is preferable to use stannous chloride, hydrazine derivatives, borane compounds, silane compounds, polyamine compounds, and the like. The reduction sensitizer may be added at any stage in the photosensitive emulsion production process from crystal growth to the preparation process immediately before coating. Further, reduction sensitization is preferable by ripening while maintaining the pH of the emulsion at 7 or more or pAg at 8.3 or less, and reduction sensitization is achieved by introducing a single addition portion of silver ions during grain formation. It is also preferable to do.

9) Compound in which 1-electron oxidant produced by 1-electron oxidation can emit 1 electron or more electrons In the photothermographic material of the present invention, 1-electron oxidant produced by 1-electron oxidation is 1 electron or 1 electron or more. It is preferable to contain a compound capable of emitting more electrons. The compound can be used alone or in combination with the above-described various chemical sensitizers, and can increase the sensitivity of silver halide.

The one-electron oxidant formed by one-electron oxidation contained in the silver halide photographic light-sensitive material of the present invention is a compound selected from the following types 1 and 2 as the compound capable of emitting one electron or more. It is.
(Type 1)
A compound in which a one-electron oxidant produced by one-electron oxidation can further emit one or more electrons with a subsequent bond cleavage reaction.
(Type 2)
A compound capable of emitting one or more electrons after a one-electron oxidant produced by one-electron oxidation undergoes a subsequent bond formation reaction.

First, the compound of type 1 will be described.
JP-A-9-211769 (specific example: page 28) is a compound of type 1 that can be further released by one-electron oxidant produced by one-electron oxidation with subsequent bond cleavage reaction. Compounds PMT-1 to S-37 described in Table E and Table F on page 32), JP-A-9-211774, JP-A-11-95355 (specific examples: compounds INV1-36), JP-T 2001-500996 No. (specific examples: compounds 1 to 74, 80 to 87, 92 to 122), US Pat. No. 5,747,235, US Pat. No. 5,747,236, European Patent No. 786692A1 (specific examples: compounds INV 1 to 35) European Patent 893732A1, US Pat. No. 6,054,260, US Pat. No. 5,994,051, etc. Compound called donor sensitizer "and the like. The preferred ranges of these compounds are the same as the preferred ranges described in the cited patent specifications.

  Further, as a compound of type 1 that can be emitted by one-electron oxidant formed by one-electron oxidation and further undergoing bond cleavage reaction, one or more electrons can be emitted from the general formula (1) ( General formula (1) described in JP-A-2003-114487), general formula (2) (synonymous with general formula (2) described in JP-A-2003-114487), general formula (3) (JP-A-2003-114487) General formula (1) described in 2003-114488), general formula (4) (synonymous with general formula (2) described in Japanese Patent Application Laid-Open No. 2003-114488), and general formula (5) (Japanese Patent Application Laid-Open No. 2003-114488). 114488 (synonymous with general formula (3)), general formula (6) (synonymous with general formula (1) described in JP-A-2003-75950), and general formula (7) (JP-A-2003-75950). In the general formula (2)), the general formula (8) (Synonymous with general formula (1) described in JP-A-2004-239943) or chemical reaction formula (1) (synonymous with chemical reaction formula (1) described in JP-A-2004-245929) Among these compounds, compounds represented by the general formula (9) (synonymous with the general formula (3) described in JP-A No. 2004-245929) can be given. The preferred ranges of these compounds are the same as the preferred ranges described in the cited patent specifications.

In the general formulas (1) and (2), RED ₁ and RED ₂ represent a reducing group. R ₁ is a non-metallic atomic group capable of forming a cyclic structure corresponding to a tetrahydro form of a 5- or 6-membered aromatic ring (including an aromatic heterocycle) or a hexahydro form together with carbon atom (C) and RED _1. To express. R ₂ , R ₃ , and R ₄ represent a hydrogen atom or a substituent. Lv ₁ and Lv ₂ represent a leaving group. ED represents an electron donating group.

In the general formulas (3), (4) and (5), Z ₁ represents an atomic group capable of forming a 6-membered ring together with the nitrogen atom and the two carbon atoms of the benzene ring. R ₅ , R ₆ , R ₇ , R ₉ , R ₁₀ , R ₁₁ , R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ , R ₁₇ , R ₁₈ , and R ₁₉ represent a hydrogen atom or a substituent. R ₂₀ represents a hydrogen atom or a substituent. When R ₂₀ represents a group other than an aryl group, R ₁₆ and R ₁₇ are bonded to each other to form an aromatic ring or an aromatic heterocycle. R ₈ and R ₁₂ represent a substituent that can be substituted on the benzene ring, m1 represents an integer of 0 to 3, and m2 represents an integer of 0 to 4. Lv ₃ , Lv ₄ and Lv ₅ represent a leaving group.

In general formulas (6) and (7), RED ₃ and RED ₄ represent a reducing group. R _{21 to} R ₃₀ represent a hydrogen atom or a substituent. Z ₂ represents —CR ₁₁₁ R ₁₁₂ —, —NR ₁₁₃ —, or —O—. R ₁₁₁ and R ₁₁₂ each independently represents a hydrogen atom or a substituent. _R113 represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group.

In the general formula (8), RED ₅ is a reducing group and represents an arylamino group or a heterocyclic amino group. R ₃₁ represents a hydrogen atom or a substituent. X represents an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, an alkylamino group, an arylamino group, or a heterocyclic amino group. Lv ₆ is a leaving group and represents a carboxy group or a salt thereof or a hydrogen atom.

The compound represented by the general formula (9) is a compound that undergoes a bond formation reaction represented by the chemical reaction formula (1) by further oxidation after two-electron oxidation accompanied by decarboxylation. In the chemical reaction formula (1), R ₃₂ and R ₃₃ represent a hydrogen atom or a substituent. Z ₃ represents a group which forms a 5-membered or 6-membered heterocycle with C═C. Z ₄ represents a group which forms a 5- or 6-membered aryl group or heterocyclic group with C═C. M represents a radical, a radical cation, or a cation. In the general formula (9), R ₃₂ , R ₃₃ and Z ₃ have the same meaning as in the chemical reaction formula (1). Z ₅ represents a group which forms a 5- or 6-membered cyclic aliphatic hydrocarbon group or heterocyclic group together with C—C.

Next, the type 2 compound will be described.
As a compound in which a one-electron oxidant produced by one-electron oxidation with a type 2 compound can further emit one or more electrons with a subsequent bond formation reaction, a compound represented by the general formula (10) A compound capable of causing a reaction represented by the general formula (1) described in 2003-140287) and the chemical reaction formula (1) (synonymous with the chemical reaction formula (1) described in JP-A-2004-245929). And a compound represented by the general formula (11) (synonymous with the general formula (2) described in JP-A No. 2004-245929). The preferred ranges of these compounds are the same as the preferred ranges described in the cited patent specifications.

In the general formula (10), RED ₆ represents a reducing group that is one-electron oxidized. Y reacts with a one-electron oxidant formed by one-electron oxidation of RED ₆ to form a new bond, a carbon-carbon double bond site, a carbon-carbon triple bond site, an aromatic group site, or Reactive group containing a non-aromatic heterocyclic moiety of a benzo-fused ring. Q represents a linking group linking RED ₆ and Y.

The compound represented by the general formula (11) is a compound that causes a bond formation reaction represented by the chemical reaction formula (1) by being oxidized. In the chemical reaction formula (1), R ₃₂ and R ₃₃ represent a hydrogen atom or a substituent. Z ₃ represents a group which forms a 5-membered or 6-membered heterocycle with C═C. Z ₄ represents a group which forms a 5- or 6-membered aryl group or heterocyclic group with C═C. Z ₅ represents a group which forms a 5- or 6-membered cyclic aliphatic hydrocarbon group or heterocyclic group together with C—C. M represents a radical, a radical cation, or a cation. In the general formula (11), R ₃₂ , R ₃₃ , Z ₃ and Z ₄ have the same meanings as those in the chemical reaction formula (1).

Of the compounds of types 1 and 2, “a compound having an adsorptive group to silver halide in the molecule” or “a compound having a partial structure of a spectral sensitizing dye in the molecule” is preferable.
Typical examples of the adsorptive group to silver halide are those described in JP-A No. 2003-156823, page 16, right line 1 to page 17, right line 12. The partial structure of the spectral sensitizing dye is a structure described on page 17, right line 34 to page 18, left line 6 of the same specification.

  More preferably, the compound of type 1 or 2 is “a compound having at least one adsorptive group to silver halide in the molecule”. More preferred is “a compound having two or more adsorptive groups to silver halide in the same molecule”. When two or more adsorptive groups are present in a single molecule, these adsorptive groups may be the same or different.

  The adsorptive group is preferably a mercapto-substituted nitrogen-containing heterocyclic group (for example, 2-mercaptothiadiazole group, 3-mercapto-1,2,4-triazole group, 5-mercaptotetrazole group, 2-mercapto-1,3,4). -Oxadiazole group, 2-mercaptobenzoxazole group, 2-mercaptobenzthiazole group, 1,5-dimethyl-1,2,4-triazolium-3-thiolate group, etc.) or imino silver (> NAg) And a nitrogen-containing heterocyclic group having a —NH— group as a heterocyclic partial structure (for example, a benzotriazole group, a benzimidazole group, an indazole group, etc.). Particularly preferred are 5-mercaptotetrazole group, 3-mercapto-1,2,4-triazole group, and benzotriazole group, most preferred are 3-mercapto-1,2,4-triazole group, and 5 -Mercaptotetrazole group.

  It is also particularly preferred that the adsorptive group has two or more mercapto groups as a partial structure in the molecule. Here, the mercapto group (—SH) may be a thione group if it can be tautomerized. Preferred examples of the adsorptive group having two or more mercapto groups as a partial structure (such as a dimercapto-substituted nitrogen-containing heterocyclic group) include 2,4-dimercaptopyrimidine group, 2,4-dimercaptotriazine group, and 3 , 5-dimercapto-1,2,4-triazole group.

  A quaternary salt structure of nitrogen or phosphorus is also preferably used as the adsorptive group. Specific examples of the quaternary salt structure of nitrogen include an ammonio group (such as a trialkylammonio group, a dialkylaryl (or heteroaryl) ammonio group, an alkyldiaryl (or heteroaryl) ammonio group) or a quaternized nitrogen atom. A group containing a nitrogen-containing heterocyclic group containing The quaternary salt structure of phosphorus includes a phosphonio group (such as a trialkylphosphonio group, a dialkylaryl (or heteroaryl) phosphonio group, an alkyldiaryl (or heteroaryl) phosphonio group, and a triaryl (or heteroaryl) phosphonio group). Is mentioned. More preferably, a quaternary salt structure of nitrogen is used, and more preferably a 5-membered or 6-membered nitrogen-containing aromatic heterocyclic group containing a quaternized nitrogen atom is used. Particularly preferably, a pyridinio group, a quinolinio group, or an isoquinolinio group is used. These nitrogen-containing heterocyclic groups containing a quaternized nitrogen atom may have an arbitrary substituent.

Examples of quaternary salt counter anions include halogen ions, carboxylate ions, sulfonate ions, sulfate ions, perchlorate ions, carbonate ions, nitrate ions, BF ₄ ⁻ , PF ₆ ⁻ and Ph ₄ B ^{− and the} like. Can be mentioned. When a group having a negative charge in the carboxylate group or the like is present in the molecule, an inner salt may be formed together with the group. As the counter anion not present in the molecule, a chlorine ion, a bromo ion or a methanesulfonate ion is particularly preferable.

  A preferred structure of the compound represented by type 1 or 2 having a quaternary salt structure of nitrogen or phosphorus as the adsorptive group is represented by the general formula (X).

In general formula (X), P and R each independently represent a quaternary salt structure of nitrogen or phosphorus that is not a partial structure of a sensitizing dye. Q ₁ and Q ₂ each independently represent a linking group, specifically a single bond, an alkylene group, an arylene group, a heterocyclic group, —O—, —S—, —NR _N —, —C (═O ) —, —SO ₂ —, —SO—, —P (═O) — each independently or a combination of these groups. Here, _RN represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group. S is a residue obtained by removing one atom from a compound represented by type (1) or (2). i and j are integers of 1 or more, and i + j is selected from the range of 2-6. Preferably, i is 1 to 3, and j is 1 to 2, more preferably i is 1 or 2, and j is 1, and particularly preferably i is 1 and j is 1. The compound represented by the general formula (X) preferably has a total carbon number of 10 to 100. More preferably, it is 10-70, More preferably, it is 11-60, Most preferably, it is 12-50.

  The compounds of type 1 and type 2 in the present invention may be used at any time during the preparation of the photosensitive silver halide emulsion and during the process of producing the photothermographic material. For example, at the time of photosensitive silver halide grain formation, desalting step, chemical sensitization, before coating. Moreover, it can also add in several steps in these processes. The addition position is preferably from the end of formation of the photosensitive silver halide grains to before the desalting step, at the time of chemical sensitization (immediately after the start of chemical sensitization to immediately after completion), and before coating, more preferably from the time of chemical sensitization Until before mixing with the non-photosensitive organic silver salt.

  The compounds of type 1 and type 2 in the present invention are preferably added after being dissolved in water, a water-soluble solvent such as methanol or ethanol, or a mixed solvent thereof. When the compound is dissolved in water, the compound having higher solubility when the pH is raised or lowered may be dissolved at a higher or lower pH and added.

The compounds of type 1 and type 2 in the present invention are preferably used in an image forming layer containing a photosensitive silver halide and a non-photosensitive organic silver salt, but the photosensitive silver halide and the non-photosensitive organic silver salt are used. It may be added to the protective layer and the intermediate layer together with the image forming layer containing, and diffused during coating. The addition timing of these compounds is preferably 1 × 10 ⁻⁹ mol to 5 × 10 ⁻¹ mol, more preferably 1 × 10 ⁻⁸ mol, per mol of silver halide, regardless of before and after the sensitizing dye. It is contained in a silver halide emulsion layer (image forming layer) at a ratio of ˜5 × 10 ⁻² mol.

10) Adsorbing redox compound having an adsorbing group and a reducing group In the present invention, it is preferable to contain an adsorbing redox compound having an adsorbing group and a reducing group for silver halide in the molecule. The adsorptive redox compound is preferably a compound represented by the following formula (I).

Formula (I) A- (W) n-B
In the formula (I), A represents a group capable of adsorbing to silver halide (hereinafter referred to as an adsorbing group), W represents a divalent linking group, n represents 0 or 1, and B represents a reducing group. To express.

  In the formula (I), the adsorption group represented by A is a group that directly adsorbs to silver halide, or a group that promotes adsorption to silver halide, and specifically, a mercapto group (or a salt thereof). , A thione group (—C (═S) —), a heterocyclic group, a sulfide group, a disulfide group, a cationic group, or an ethynyl group containing at least one atom selected from a nitrogen atom, a sulfur atom, a selenium atom, and a tellurium atom Etc.

The mercapto group (or salt thereof) as the adsorptive group means the mercapto group (or salt thereof) itself, and more preferably a heterocyclic group or aryl group substituted with at least one mercapto group (or salt thereof) or Represents an alkyl group. Here, the heterocyclic group is at least a 5- to 7-membered monocyclic or condensed aromatic or non-aromatic heterocyclic group such as an imidazole ring group, a thiazole ring group, an oxazole ring group, or a benzimidazole ring. Group, benzothiazole ring group, benzoxazole ring group, triazole ring group, thiadiazole ring group, oxadiazole ring group, tetrazole ring group, purine ring group, pyridine ring group, quinoline ring group, isoquinoline ring group, pyrimidine ring group, And triazine ring group. Moreover, the heterocyclic group containing the quaternized nitrogen atom may be sufficient, and in this case, the substituted mercapto group may dissociate and it may become a meso ion. When the mercapto group forms a salt, the counter ion is a cation such as alkali metal, alkaline earth metal, or heavy metal (such as Li ⁺ , Na ⁺ , K ⁺ , Mg ²⁺ , Ag ⁺ , or Zn ²⁺ ), ammonium Examples thereof include an ion, a heterocyclic group containing a quaternized nitrogen atom, and a phosphonium ion.
Further, the mercapto group as the adsorptive group may be tautomerized into a thione group.
The thione group as an adsorptive group includes a chain or cyclic thioamide group, thioureido group, thiourethane group, or dithiocarbamate group.
A heterocyclic group containing at least one atom selected from a nitrogen atom, a sulfur atom, a selenium atom and a tellurium atom as an adsorptive group is a -NH- group capable of forming imino silver (> NAg) as a partial structure of the heterocyclic ring. A nitrogen-containing heterocyclic group, or a “—S—” group, a “—Se—” group, a “—Te—” group, or a “═N—” group that can be coordinated to a silver ion by a coordination bond. The former examples include benzotriazole groups, triazole groups, indazole groups, pyrazole groups, tetrazole groups, benzimidazole groups, imidazole groups, or purine groups, and the latter examples include thiophene groups. Group, thiazole group, oxazole group, benzothiophene group, benzothiazole group, benzoxazole group, thiadiazole group, oxadiazole group Triazine group, seleno azole group, benzoselenazole group, tellurium azole group, and the like benzo tellurium azole group.
Examples of the sulfide group or disulfide group as the adsorptive group include all groups having a partial structure of -S- or -SS-.
The cationic group as the adsorptive group means a group containing a quaternized nitrogen atom, specifically, an ammonio group or a group containing a nitrogen-containing heterocyclic group containing a quaternized nitrogen atom. Examples of the nitrogen-containing heterocyclic group containing a quaternized nitrogen atom include a pyridinio group, a quinolinio group, an isoquinolinio group, and an imidazolio group.
An ethynyl group as an adsorbing group means a —C≡CH group, and the hydrogen atom may be substituted.
The adsorbing group may have an arbitrary substituent.

  Further, specific examples of the adsorbing group are further described in JP-A-11-95355, p. 4-p. 7 are mentioned.

  In the formula (I), preferred as the adsorptive group represented by A is a mercapto-substituted heterocyclic group (for example, 2-mercaptothiadiazole group, 2-mercapto-5-aminothiadiazole group, 3-mercapto-1,2,4). -Triazole group, 5-mercaptotetrazole group, 2-mercapto-1,3,4-oxadiazole group, 2-mercaptobenzimidazole group, 1,5-dimethyl-1,2,4-triazolium-3-thiolate group 2,4-dimercaptopyrimidine group, 2,4-dimercaptotriazine group, 3,5-dimercapto-1,2,4-triazole group, or 2,5-dimercapto-1,3-thiazole group), Alternatively, a nitrogen-containing heterocyclic group having a —NH— group that can form imino silver (> NAg) as a heterocyclic partial structure (for example, benzoto Azole group, benzimidazole group, an indazole group), more preferable as an adsorptive group is a 2-mercaptobenzimidazole group, a 3,5-dimercapto-1,2,4-triazole group.

In formula (I), W represents a divalent linking group. Any linking group may be used as long as it does not adversely affect photographic properties. For example, a divalent linking group composed of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, or a sulfur atom can be used. Specifically, an alkylene group having 1 to 20 carbon atoms (for example, a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, etc.), an alkenylene group having 2 to 20 carbon atoms, and an alkynylene group having 2 to 20 carbon atoms. , An arylene group having 6 to 20 carbon atoms (eg, phenylene group, naphthylene group, etc.), —CO—, —SO ₂ —, —O—, —S—, —NR ₁ —, combinations of these linking groups, and the like. It is done. Here, R ₁ represents a hydrogen atom, an alkyl group, a heterocyclic group, or an aryl group.
The linking group represented by W may have an arbitrary substituent.

  In formula (I), the reducing group represented by B represents a group capable of reducing silver ions. For example, a triple bond group such as formyl group, amino group, acetylene group or propargyl group, mercapto group, hydroxylamines. Hydroxamic acids, hydroxyureas, hydroxyurethanes, hydroxysemicarbazides, reductones (including reductone derivatives), anilines, phenols (chroman-6-ols, 2,3-dihydrobenzofuran-5-ols, (Including aminophenols, sulfonamidophenols, and hydroquinones, catechols, resorcinols, polyphenols such as benzenetriols, bisphenols), acylhydrazines, carbamoylhydrazines, 3-pyrazolidones, etc. Residue with one removed And the like. Of course, these may have an arbitrary substituent.

In the formula (I), the reducing group represented by B shows its oxidation potential, Akira Fujishima “Electrochemical Measurement Method” (pages 150-208, published by Gihodo) or the Chemical Society of Japan “Experimental Chemistry Course” 4th edition. It can be measured using the measurement method described in (Vol. 9, pages 282 to 344, Maruzen). For example, by rotating disk voltammetry, specifically, a sample is dissolved in a solution of methanol: pH 6.5, Briton-Robinson buffer (Britton-Robinson buffer) = 10%: 90% (volume%), and nitrogen is added for 10 minutes. After aeration of gas, a rotating disc electrode (RDE) made of glassy carbon is used as a working electrode, a platinum wire is used as a counter electrode, a saturated calomel electrode is used as a reference electrode, 25 ° C., 1000 rev / min, 20 mV / sec. It can be measured at the sweep speed. A half-wave potential (E1 / 2) can be obtained from the obtained voltammogram.
In the present invention, the reducing group represented by B preferably has an oxidation potential in the range of about -0.3 V to about 1.0 V when measured by the above measurement method. More preferably, it is in the range of about -0.1V to about 0.8V, and particularly preferably in the range of about 0V to about 0.7V.

  In the formula (I), the reducing group represented by B is preferably selected from hydroxylamines, hydroxamic acids, hydroxyureas, hydroxysemicarbazides, reductones, phenols, acylhydrazines, carbamoylhydrazines, and 3-pyrazolidones. A residue obtained by removing one hydrogen atom.

  The compound of the formula (I) in the present invention may be one in which a ballast group or polymer chain commonly used in an immobile photographic additive such as a coupler is incorporated. Examples of the polymer include those described in JP-A-1-100530.

  The compound of the formula (I) in the present invention may be a bis form or a tris form. The molecular weight of the compound of formula (I) in the present invention is preferably between 100 and 10000, more preferably between 120 and 1000, particularly preferably between 150 and 500.

  Examples of the compound of formula (I) in the present invention are shown below, but the present invention is not limited thereto.

  Furthermore, specific compounds 1 to 30 and 1 ″ -1 to 1 ″ -77 described in European Patent No. 1308776A2 p73 to p87 are also preferable examples of the compound having an adsorbing group and a reducing group in the present invention.

  These compounds can be easily synthesized according to known methods. As the compound of the formula (I) in the present invention, one kind of compound may be used alone, but it is also preferred to use two or more kinds of compounds at the same time. When two or more kinds of compounds are used, they may be added in the same layer or in different layers, and the addition method may be different.

The compound of formula (I) in the present invention is preferably added to the silver halide image forming layer, and more preferably added during the preparation of the emulsion. When added at the time of emulsion preparation, it can be added at any time during the process. For example, silver halide grain formation process, before desalting process start, desalting process, chemical ripening Examples include a step before starting, a chemical ripening step, and a step before preparing a finished emulsion. Moreover, it can also add in several steps in these processes. Although it is preferably used for the image forming layer, it may be added to the adjacent protective layer or intermediate layer together with the image forming layer and diffused during coating.
The preferred addition amount largely depends on the above-mentioned addition method and the kind of the compound to be added, but generally 1 × 10 ⁻⁶ mol to 1 mol, preferably 1 × 10 ⁻⁵ mol per mol of photosensitive silver halide. The amount is 5 × 10 ⁻¹ mol or less, more preferably 1 × 10 ⁻⁴ mol or more and 1 × 10 ⁻¹ mol or less.

  The compound of the formula (I) in the present invention can be added after being dissolved in water, a water-soluble solvent such as methanol or ethanol, or a mixed solvent thereof. At this time, the pH may be appropriately adjusted with an acid or a base, and a surfactant may be allowed to coexist. Furthermore, it can also be dissolved in a high boiling point organic solvent and added as an emulsified dispersion. It can also be added as a solid dispersion.

11) Multiple silver halides in combination The photosensitive silver halide emulsion in the light-sensitive material used in the present invention may be only one kind, or two or more kinds (for example, those having different average grain sizes, those having different halogen compositions, Those having different crystal habits and different chemical sensitization conditions may be used in combination. The gradation can be adjusted by using a plurality of types of photosensitive silver halides having different sensitivities. As techniques relating to these, there are JP-A-57-119341, 53-106125, 47-3929, 48-55730, 46-5187, 50-73627, 57-150841, and the like. Can be mentioned. The sensitivity difference is preferably 0.2 log E or more for each emulsion.

12) Coating amount The addition amount of the photosensitive silver halide is preferably 0.03 g / m ² or more and 0.6 g / m ² or less, expressed as the coating silver amount per 1 m ² of the light-sensitive material. / M ² or more and 0.4 g / m ² or less is more preferable, and 0.07 g / m ² or more and 0.3 g / m ² or less is most preferable. The functional silver halide is preferably from 0.01 mol to 0.5 mol, more preferably from 0.02 mol to 0.3 mol, and still more preferably from 0.03 mol to 0.2 mol.

13) Mixing of photosensitive silver halide and organic silver salt Regarding the mixing method and mixing conditions of separately prepared photosensitive silver halide and organic silver salt, the silver halide grains and the organic silver salt that were prepared are respectively stirred at high speed. Prepare an organic silver salt by mixing with a machine, ball mill, sand mill, colloid mill, vibration mill, homogenizer, etc., or by mixing photosensitive silver halide that has been prepared at any time during the preparation of the organic silver salt However, there is no particular limitation as long as the effects of the present invention are sufficiently exhibited. In addition, mixing two or more organic silver salt aqueous dispersions and two or more photosensitive silver salt aqueous dispersions when mixing is a preferred method for adjusting photographic characteristics.

14) Mixing of silver halide into coating solution The preferred addition time of silver halide into the image forming layer coating solution is from 180 minutes before application, preferably from 60 minutes to 10 seconds before application. The method and mixing conditions are not particularly limited as long as the effects of the present invention are sufficiently exhibited. Specific mixing methods include mixing in a tank in which the average residence time calculated from the addition flow rate and the amount of liquid fed to the coater is the desired time, and N.I. Harnby, M.M. F. Edwards, A.D. W. There is a method using a static mixer described in Chapter 8 of Nienow's "Liquid Mixing Technology" (Nikkan Kogyo Shimbun, 1989), translated by Koji Takahashi.

(Description of antifogging agent)
Antifogging agents, stabilizers and stabilizer precursors that can be used in the present invention are paragraph No. 0070 of JP-A No. 10-62899, European Patent Publication No. 0803764A, page 20, line 57 to page 21, line 7. And the compounds described in JP-A-9-281737 and JP-A-9-329864, and the compounds described in US Pat. No. 6,083,681 and European Patent 1048875.

1) Organic polyhalogen compound Hereinafter, preferred organic polyhalogen compounds that can be used in the present invention will be described in detail. A preferred polyhalogen compound in the present invention is a compound represented by the following general formula (H).
General formula (H)
Q- (Y) n-C (Z ₁ ) (Z ₂ ) X
In General Formula (H), Q represents an alkyl group, an aryl group, or a heterocyclic group, Y represents a divalent linking group, n represents 0 to ₁ , Z ₁ and Z ₂ represent a halogen atom, X represents a hydrogen atom or an electron withdrawing group.
In the general formula (H), Q is preferably an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a heterocyclic group containing at least one nitrogen atom (pyridine, quinoline group, etc.).
In the general formula (H), when Q is an aryl group, Q preferably represents a phenyl group substituted with an electron-attracting group having a positive Hammett's substituent constant σp. For Hammett's substituent constants, see Journal of Medicinal Chemistry, 1973, Vol. 16, no. 11, 1207-1216 etc. can be referred to.
Examples of such an electron withdrawing group include a halogen atom, an alkyl group substituted with an electron withdrawing group, an aryl group substituted with an electron withdrawing group, a heterocyclic group, an alkyl or arylsulfonyl group, acyl Group, alkoxycarbonyl group, carbamoyl group, sulfamoyl group and the like. Particularly preferred as the electron withdrawing group are a halogen atom, a carbamoyl group and an arylsulfonyl group, and a carbamoyl group is particularly preferred.
X is preferably an electron withdrawing group. Preferred electron withdrawing groups are halogen atoms, aliphatic / aryl or heterocyclic sulfonyl groups, aliphatic / aryl or heterocyclic acyl groups, aliphatic / aryl or heterocyclic oxycarbonyl groups, carbamoyl groups, sulfamoyl groups, More preferred are a halogen atom and a carbamoyl group, and particularly preferred is a bromine atom.
Z ₁ and Z ₂ are preferably a bromine atom or an iodine atom, and more preferably a bromine atom.
Y preferably represents -C (= O) -, - SO -, - SO 2 -, - C (= O) N (R) -, or -SO ₂ N (R) -, more preferably -C (═O) —, —SO ₂ —, —C (═O) N (R) —, particularly preferably —SO ₂ —, —C (═O) N (R) —. R here represents a hydrogen atom, an aryl group or an alkyl group, more preferably a hydrogen atom or an alkyl group, and particularly preferably a hydrogen atom.
n represents 0 or 1, and is preferably 1.
In General Formula (H), when Q is an alkyl group, preferred Y is —C (═O) N (R) —, and when Q is an aryl group or a heterocyclic group, preferred Y is —SO ₂ —. is there.
In the general formula (H), a form in which residues obtained by removing a hydrogen atom from the compound are bonded to each other (generally referred to as bis type, tris type, tetrakis type) can also be preferably used.
In the general formula (H), a dissociable group (for example, a COOH group or a salt thereof, a SO ₃ H group or a salt thereof, a PO ₃ H group or a salt thereof), a group containing a quaternary nitrogen cation (for example, an ammonium group or a pyridinium group) Etc.), those having a polyethyleneoxy group, a hydroxyl group or the like as a substituent are also preferred.

  Specific examples of the compound represented by formula (H) in the present invention are shown below.

  Polyhalogen compounds that can be used in the present invention other than those described above include US Pat. No. 3,874,946, US Pat. No. 4,756,999, US Pat. No. 5,340,712, US Pat. No. 5,346,737, US Pat. No. 5,466,537, JP-A-50-137126, US Pat. 119624, 59-57234, JP-A-7-2781, 7-5621, 9-160164, 9-244177, 9-244178, 9-160167, 9- 319022, 9-258367, 9-265150, 9-319022, 10-197988, 10-197989, 11-242304, JP 2000-2963, JP 2000-11270 , JP2000-284410, JP2 The compounds listed as exemplary compounds of the invention in 00-284212, JP-A-2001-33911, JP-A-2001-31644, JP-A-2001-312027, and JP-A-2003-50441 are preferably used. In particular, compounds specifically exemplified in JP-A-7-2781, JP-A-2001-33911, and JP-A-2001-312027 are preferred.

The compound represented by formula (H) in the present invention is preferably used in the range of 10 ⁻⁴ mol to 1 mol, more preferably 10 ⁻³ , per mol of the non-photosensitive silver salt in the image forming layer. It is preferable to use in the range of not less than 0.5 mol and not more than 0.5 mol, more preferably not less than 1 × 10 ⁻² mol and not more than 0.2 mol.
In the present invention, examples of the method for incorporating the antifoggant into the light-sensitive material include the methods described in the method for containing a reducing agent, and the organic polyhalogen compound is also preferably added as a solid fine particle dispersion.

2) Other antifoggants Other antifoggants include mercury (II) salts described in paragraph No. 0113 of JP-A No. 11-65021, benzoic acids described in paragraph No. 0114 of the same, salicylic acid derivatives of JP-A No. 2000-206642, A formalin scavenger compound represented by the formula (S) in JP-A-2000-221634, a triazine compound according to claim 9 in JP-A-11-352624, and a compound represented by the general formula (III) in JP-A-6-11791 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene and the like.

The photothermographic material in the invention may contain an azolium salt for the purpose of preventing fogging. Examples of the azolium salt include compounds represented by general formula (XI) described in JP-A-59-193447, compounds described in JP-B-55-12581, and general formula (II) described in JP-A-60-153039. And the compounds represented. The azolium salt may be added to any part of the light-sensitive material, but the addition layer is preferably added to the layer having the image forming layer, and more preferably added to the image forming layer. The azolium salt may be added at any step during the preparation of the coating solution, and when added to the image forming layer, any step from the preparation of the organic silver salt to the preparation of the coating solution may be used. Immediately before is preferable. The azolium salt may be added by any method such as powder, solution, or fine particle dispersion. Moreover, you may add as a solution mixed with other additives, such as a sensitizing dye, a reducing agent, and a color toning agent. In the present invention, the azolium salt may be added in any amount, but it is preferably 1 × 10 ⁻⁶ mol or more and 2 mol or less, and more preferably 1 × 10 ⁻³ mol or more and 0.5 mol or less per 1 mol of silver.

(Other additives)
1) Mercapto, disulfide, and thiones In the present invention, mercapto compounds and disulfide compounds are used for the purpose of controlling development by suppressing or promoting development, improving spectral sensitization efficiency, and improving storage stability before and after development. And thione compounds, paragraphs 0067 to 0069 of JP-A-10-62899, compounds represented by formula (I) of JP-A-10-186572, and specific examples thereof include paragraph numbers 0033 to 0052. , European Patent Publication No. 0803764A1, page 20, lines 36-56. Of these, mercapto-substituted heteroaromatic compounds described in JP-A-9-297367, JP-A-9-304875, JP-A-2001-100388, JP-A-2002-303954, JP-A-2002-303951, and the like are preferable. .

2) Toning agent In the photothermographic material of the invention, it is preferable to add a toning agent. For the toning agent, paragraph numbers 0054 to 0055 of JP-A-10-62899, page 21 to 23 of European Patent Publication No. 0803764A1. Line 48, described in JP-A No. 2000-356317 and JP-A No. 2000-187298, and in particular, phthalazinones (phthalazinone, phthalazinone derivatives or metal salts; for example, 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone. 5,7-dimethoxyphthalazinone and 2,3-dihydro-1,4-phthalazinedione); phthalazinones and phthalic acids (eg, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, diammonium phthalate) , Sodium phthalate, potassium phthalate and tetrachlorophthalic anhydride) Combinations; phthalazines (phthalazine, phthalazine derivatives or metal salts; for example, 4- (1-naphthyl) phthalazine, 6-isopropylphthalazine, 6-t-butylphthalazine, 6-chlorophthalazine, 5,7-dimethoxyphthalazine And 2,3-dihydrophthalazine); a combination of phthalazines and phthalic acids is preferable, and a combination of phthalazines and phthalic acids is particularly preferable. Among them, a particularly preferable combination is a combination of 6-isopropylphthalazine and phthalic acid or 4-methylphthalic acid.

3) Plasticizers and lubricants In the present invention, known plasticizers and lubricants can be used to improve film physical properties. In particular, it is preferable to use a lubricant such as liquid paraffin, long chain fatty acid, fatty acid amide, fatty acid ester, etc., in order to improve handling at the time of manufacture and scratch resistance at the time of heat development. In particular, liquid paraffin from which low-boiling components have been removed and fatty acid esters having a branched structure and having a molecular weight of 1000 or more are preferred.
Regarding the plasticizer and lubricant that can be used in the image forming layer and the non-photosensitive layer, JP-A No. 11-65021, paragraph No. 0117, JP-A No. 2000-5137, JP-A No. 2004-219794, JP-A No. 2004-21802, The compounds described in JP-A-2004-334077 are preferred.

4) Dye and Pigment In the image forming layer of the present invention, various dyes and pigments (for example, CI Pigment Blue 60, C.I. Pigment Blue 64, CI Pigment Blue 15: 6) can be used. These are described in detail in WO98 / 36322, JP-A-10-268465, JP-A-11-338098 and the like.

5) Nucleating Agent In the photothermographic material of the invention, it is preferable to add a nucleating agent to the image forming layer. Regarding the nucleating agent, the addition method and the addition amount thereof, paragraph No. 0118 of JP-A No. 11-65021, paragraph Nos. 0136 to 0193 of JP-A No. 11-223898, and formula (H) of JP-A No. 2000-284399. , Compounds of formulas (1) to (3), formulas (A) and (B), compounds of general formulas (III) to (V) described in JP-A 2000-347345 (specific compounds: The nucleation promoter is described in paragraph No. 0102 of JP-A No. 11-65021 and paragraph Nos. 0194 to 0195 of JP-A No. 11-223898.

  In order to use formic acid or formate as a strong fogging substance, it is preferably contained in an amount of 5 mmol or less, more preferably 1 mmol or less per mol of silver on the side having an image forming layer containing photosensitive silver halide.

When a nucleating agent is used in the photothermographic material of the present invention, it is preferable to use an acid formed by hydrating 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), hexametalin An acid (salt) etc. can be mentioned. Examples of the acid or salt thereof formed by hydrating diphosphorus pentoxide particularly preferably include orthophosphoric acid (salt) and hexametaphosphoric acid (salt). Specific examples of the salt include sodium orthophosphate, sodium dihydrogen orthophosphate, sodium hexametaphosphate, and ammonium hexametaphosphate.
The amount of acid or salt thereof formed by hydration of diphosphorus pentoxide (the coating amount per 1 m ^{2 of the} photosensitive material) may be a desired amount according to the performance such as sensitivity and fogging, but is 0.1 mg / m ^2. It is preferably 500 mg / m ² or less, more preferably 0.5 mg / m ² or more and 100 mg / m ² or less.

(Preparation and application of coating solution)
The preparation temperature of the image forming layer coating solution in the invention is preferably from 30 ° C. to 65 ° C., more preferably from 35 ° C. to less than 60 ° C., and more preferably from 35 ° C. to 55 ° C. Moreover, it is preferable that the temperature of the image forming layer coating liquid immediately after the addition of the polymer latex is maintained at 30 ° C. or higher and 65 ° C. or lower.

(Membrane surface pH)
The photothermographic material of the present invention preferably has a film surface pH of 7.0 or less, more preferably 6.6 or less before heat development. The lower limit is not particularly limited, but is about 3. The most preferred pH range is in the range of 4 to 6.2. The film surface pH is preferably adjusted using an organic acid such as a phthalic acid derivative, a non-volatile 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 volatile and is preferable for achieving a low film surface pH because it can be removed before the coating process or heat development.
In addition, it is also preferable to use ammonia in combination with a nonvolatile base such as sodium hydroxide, potassium hydroxide, or lithium hydroxide. A method for measuring the film surface pH is described in paragraph No. 0123 of JP-A No. 2000-284399.

(Antistatic agent)
In the present invention, it is preferable to have a conductive layer containing a metal oxide or a conductive polymer. The antistatic layer may serve as an undercoat layer, a back layer surface protective layer, or the like, or may be provided separately. As the conductive material for the antistatic layer, a metal oxide in which conductivity is improved by introducing oxygen defects or different metal atoms into the metal oxide is preferably used. Examples of metal oxides are preferably ZnO, TiO ₂ and SnO _2. Addition of Al and In to ZnO, addition of Sb, Nb, P and halogen elements to SnO ₂ , and addition to TiO _2. For example, addition of Nb, Ta or the like is preferable.
In particular, SnO ₂ added with Sb is preferable. The amount of different atoms added is preferably in the range of 0.01 mol% to 30 mol%, and more preferably in the range of 0.1 mol% to 10 mol%. The shape of the metal oxide may be spherical, needle-like, or plate-like, but the long axis / uniaxial ratio is 2.0 or more, preferably 3.0 to 50 in terms of the effect of imparting conductivity. Good. Range amount preferably of 1mg / m ² ~1000mg / m ² of metal oxide, more preferably 10mg / m ² ~500mg / m ² range, more preferably at 20mg / m ² ~200mg / m ² It is a range.
The antistatic layer in the present invention may be disposed on either the image forming layer surface side or the back surface side, but is preferably disposed between the support and the back layer. Specific examples of the antistatic layer are disclosed in paragraph No. 0135 of JP-A No. 11-65021, JP-A Nos. 56-143430, 56-143431, 58-62646, No. 56-120519 and JP-A No. 11-84573. Paragraph Nos. 0040 to 0051, US Pat. No. 5,575,957, and JP-A-11-223898, paragraph Nos. 0078 to 0084.

(Support)
The transparent support is a polyester subjected to heat treatment in a temperature range of 130 ° C. to 185 ° C. in order to alleviate internal strain remaining in the film during biaxial stretching and eliminate heat shrinkage strain generated during heat development processing, particularly Polyethylene terephthalate is preferably used. In the case of a photothermographic material for medical use, the transparent support may be colored with a blue dye (for example, dye-1 described in Examples of JP-A-8-240877) or may be uncolored. Examples of the support include water-soluble polyesters disclosed in JP-A-11-84574, styrene-butadiene copolymers described in JP-A-10-186565, and vinylidene chloride described in JP-A-2000-39684 and Japanese Patent Application No. 11-106881, paragraph numbers 0063 to 0080. It is preferable to apply an undercoating technique such as a copolymer. When the image forming layer or the back layer is applied to the support, the water content of the support is preferably 0.5 wt% or less.

(Other additives)
An antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, or a coating aid may be further added to the photothermographic material. Various additives are added to either the image forming layer or the non-image forming layer. With respect to these, WO 98/36322, EP 803764A1, JP-A-10-186567, 10-18568 and the like can be referred to.

(Other available technologies)
Techniques that can be used in the photothermographic material of the present invention include EP80364A1, EP883022A1, WO98 / 36322, JP56-62648, 58-62644, JP9-43766, and 9-. 281637, 9-297367, 9-304869, 9-311405, 9-329865, 10-10669, 10-62899, 10-69023, 10-186568, 10-90823, 10-1106103, 10-186565, 10-186567, 10-186567 to 10-186572, 10-197974, 10-197982, 10 -197983, 10-197985 to 10-197987, 10- 07001, 10-207004, 10-221807, 10-282601, 10-288823, 10-288824, 10-307365, 10-312038, 10-339934 11-7100, 11-15105, 11-24200, 11-24201, 11-30201, 11-30832, 11-84574, 11-65021, 11-109547, 11-125880, 11-129629, 11-133536 to 11-133539, 11-133542, 11-133543, 11-223898, 11-352627, 11- 305377, 11-305378, 11-305384, 11-30538 11-316435, 11-327076, 11-338096, 11-338098, 11-338099, 11-343420, 2001-200414, 2001-234635, 2002-020699, 2001-275471, 2001-275461, 2000-313204, 2001-292844, 2000-324888, 2001-293864, 2001-348546, JP No. 2000-187298 is also mentioned.

(Image forming method)
1) Exposure The photothermographic material of the present invention may be image-exposed by any method, but a laser beam is preferred as the exposure light source. As the laser beam that can be used in the present invention, a gas laser (Ar ⁺ , He—Ne), a YAG laser, a dye laser, a semiconductor laser, and the like are preferable. Also, a semiconductor laser and a second high frequency generator can be used.
Preferably, it is a red to infrared emission gas or a semiconductor laser, and the peak wavelength of the laser beam is 600 nm to 900 nm, preferably 620 nm to 680 nm.

2) Photothermographic development The photothermographic material of the present invention may be developed by any method, but is usually developed by raising the temperature of the photothermographic material exposed imagewise. A preferred development temperature is 80 ° C to 250 ° C, preferably 100 ° C to 140 ° C, and more preferably 110 ° C to 130 ° C. The development time is preferably 1 second to 15 seconds, more preferably 1 second to 10 seconds, and further preferably 2 seconds to 8 seconds. By using the photothermographic material of the present invention, rapid thermal development can be achieved.

  Either a drum type heater or a plate type heater may be used as the thermal development method, but the plate type heater method is more preferable. The thermal development method using the plate heater method is preferably the method described in JP-A-11-133572, and a visible image is obtained by bringing the photothermographic material having a latent image formed thereon into contact with the heating means in the thermal development unit. In the heat development apparatus, the heating unit includes a plate heater, and a plurality of press rollers are disposed to face each other along one surface of the plate heater, and the press roller is disposed between the press roller and the plate heater. A photothermographic apparatus for carrying out heat development by passing a photothermographic material. It is preferable to divide the plate heater into 2 to 6 stages and lower the temperature about 1 ° C. to 10 ° C. at the tip. For example, there are examples in which four sets of plate heaters that can be independently controlled are used and controlled to 112 ° C., 119 ° C., 121 ° C., and 120 ° C., respectively. Such a method is also described in JP-A No. 54-30032, which can exclude moisture and organic solvents contained in the photothermographic material out of the system, and rapidly develop the photothermographic material. It is also possible to suppress the change in the shape of the support of the photothermographic material due to the heating.

  In order to reduce the size of the heat developing machine and shorten the heat development time, it is preferable to be able to control the heater more stably. In addition, the exposure of one sheet of photosensitive material is started from the top and the exposure is finished to the back end. It is desirable to start the heat development before the time. Imagers capable of rapid processing preferable for the present invention are described in, for example, JP-A Nos. 2002-289804 and 2003-285455. If this imager is used, for example, heat development can be performed in 14 seconds with a three-stage plate heater controlled at 107 ° C.-121 ° C.-121 ° C. The output time of the first sheet is shortened to about 60 seconds. be able to.

3) System As a medical laser imager provided with an exposure part and a heat development part, Fuji Medical Dry Laser Imager FM-DPL and DRYPIX7000 can be exemplified. Regarding FM-DPL, Fuji Medical Review No. 8, pages 39 to 55, and it goes without saying that these techniques are applied as a laser imager of the photothermographic material of the present invention. Further, it can also be applied as a photothermographic material for a laser imager in “AD network” proposed by Fuji Film Medical Co., Ltd. as a network system adapted to the DICOM standard.

(Use of the present invention)
The photothermographic material of the present invention forms a black and white image by a silver image, and is used as a photothermographic material for medical diagnosis, a photothermographic material for industrial photography, a photothermographic material for printing, and a photothermographic material for COM. It is preferably used. In particular, it is preferably used as a photothermographic material for medical diagnosis.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

First, the measurement results of the maximum absorption wavelength and the half value width of the absorption spectrum of the dye in the present invention are shown together with the comparative dye.
1. Preparation of sample 1) Preparation of coating solution 30 g of gelatin and 3 mg of benzoisothiazolinone were dissolved in 850 mL of water, and 180 g of styrene-butadiene copolymer latex (solid content 40 mass%, styrene / butadiene mass ratio = 68/32) 60 g of 10% by weight aqueous solution of the present invention or comparative dye or comparative pigment and dye dispersion (shown in Table 2), 40 g of 10% by weight emulsion of dipentaerythrityl hexaisostearate, fluorine-based surfactant (F-1 ) 5.5%, 1% by weight aqueous solution of fluorosurfactant (F-2) 5.5mL, 28% by weight 5% aqueous solution of di (2-ethylhexyl) sodium sulfosuccinate, poly 4 g of methyl methacrylate fine particles (average particle size 0.7 μm, volume weighted average distribution 30%), and polymethyl 21 g of methacrylate fine particles (average particle size 3.6 μm, volume weighted average distribution 60%) were mixed.

  The following β-substituted phthalocyanine compound was used as a comparative dye-1.

  As comparative dye dispersions, the following comparative pigment-1 dispersion and dispersion 101 described in JP-A No. 2003-43628 and dispersions 102, 103, 106, 107, and 109 described in JP-A No. 2003-84395 are described. Used

<< Preparation of Comparative Pigment-1 Dispersion >>
C. I. Pigment Blue 60 (64 g) and Kao Corp. Demol N (6.4 g) were added to 250 g of water and mixed well to obtain a slurry. Prepare 800 g of zirconia beads having an average diameter of 0.5 mm, put them in a vessel together with the slurry, and disperse with a disperser (1/4 G sand grinder mill: manufactured by IMEX Co., Ltd.) for 25 hours. A pigment-1 dispersion was obtained by adjusting the concentration to 5% by mass. The pigment particles contained in the pigment dispersion thus obtained had an average particle size of 0.21 μm.

2) Application | coating The said coating liquid was apply | coated so that it might become 8.3 mL / m < ² > on the 175 micrometers PET support body which gave the undercoat.

2. Measurement of absorption spectrum With a spectrophotometer (U-3500, manufactured by Hitachi, Ltd.), a transmission spectral absorption spectrum in the range of 400 nm to 900 nm was measured for the coated sample. Table 2 shows the results of measuring the maximum absorption wavelength and the half width at that wavelength.

Example 1
(Preparation of PET support)
1) Film formation Using terephthalic acid and ethylene glycol, PET having an intrinsic viscosity of IV = 0.66 (measured at 25 ° C. in phenol / tetrachloroethane = 6/4 (mass ratio)) is obtained according to a conventional method. It was. This was pelletized, dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die, and rapidly cooled to prepare an unstretched film.

This was longitudinally stretched 3.3 times using rolls with different peripheral speeds, and then stretched 4.5 times with a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively. Thereafter, the film was heat-fixed at 240 ° C. for 20 seconds and relaxed by 4% in the lateral direction at the same temperature. Thereafter, the chuck portion of the tenter was slit and then knurled at both ends, and wound at 4 kg / cm ² to obtain a roll having a thickness of 175 μm.

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

3) Undercoat <Preparation of undercoat layer coating solution>
Formula (1) (for image forming layer side undercoat layer)
・ Pesresin A-520 (30% by mass solution) manufactured by Takamatsu Yushi Co., Ltd. 46.8 g
・ Toyobo Co., Ltd. Bironal MD-1200 10.4 g
Polyethylene glycol monononyl phenyl ether (average ethylene oxide number = 8.5) 1% by mass solution 11.0 g
・ MP-1000 (PMMA polymer fine particles, average particle size 0.4 μm) manufactured by Soken Chemical Co., Ltd.
0.91g
・ Distilled water 931mL

Formula (2) (for back layer 1st layer)
・ Styrene-butadiene copolymer latex 130.8 g
(Solid content 40% by mass, styrene / butadiene mass ratio = 68/32)
2,4-dichloro-6-hydroxy-S-triazine sodium salt (8% by mass aqueous solution)
5.2g
・ 10 mL of 1% by weight aqueous solution of sodium laurylbenzenesulfonate
・ Polystyrene particle dispersion (average particle size 2 μm, 20 mass%) 0.5 g
-854 mL of distilled water

Formula (3) (for back side second layer)
SnO ₂ / SbO (9/1 mass ratio, average particle size 0.5 μm, 17 mass% dispersion)
84g
・ Gelatin 7.9g
・ Shin-Etsu Chemical Co., Ltd. Metros TC-5 (2 mass% aqueous solution) 10g
・ 10% 1% aqueous solution of sodium dodecylbenzenesulfonate
・ NaOH (1% by mass) 7 g
・ Proxel (Abyssia) 0.5g
・ 881mL distilled water

After both surfaces of the biaxially stretched polyethylene terephthalate support having a thickness of 175 μm are subjected to the corona discharge treatment, the undercoat coating solution formulation (1) is applied on one side (image forming layer surface) with a wire bar with a wet coating amount of 6. .6mL / m ² was applied (per one side) and dried for 5 minutes at 180 ° C., then the amount of wet coating the coating solution for the undercoat was coated (2) by a wire bar on the rear surface (back surface) 5. was applied so as to 7 mL / m ² and dried 5 minutes at 180 ° C., wet coating amount is 8.4 mL / m ² further backside (the back face) the coating solution for the undercoat was coated (3) with a wire bar It was applied as described above and dried at 180 ° C. for 6 minutes to prepare an undercoat support.

(Back layer)
1) Preparation of back layer coating solution (preparation of solid fine particle dispersion (a) of base precursor)
Add 2.5 kg of Base Precursor Compound 1 and 300 g of a surfactant (trade name: Demol N, manufactured by Kao Corporation), 800 g of diphenylsulfone, 1.0 g of benzoisothiazolinone sodium salt and distilled water to make a total amount. The mixture was mixed to 8.0 kg, and the mixed solution was dispersed with beads using a horizontal sand mill (UVM-2: manufactured by Imex Corporation). In the dispersion method, the mixed solution was fed to UVM-2 filled with zirconia beads having an average diameter of 0.5 mm by a diaphragm pump, and dispersed in a state where the internal pressure was 50 hPa or more until a desired average particle size was obtained.
The dispersion was subjected to spectral absorption measurement, and the ratio of the absorbance at 450 nm to the absorbance at 650 nm (D ₄₅₀ / D ₆₅₀ ) in the spectral absorption of the dispersion was dispersed to 3.0. The obtained dispersion was diluted with distilled water so that the concentration of the base precursor was 25% by mass, and was filtered for removal of dust (polypropylene filter having an average pore size of 3 μm) for practical use.

2) Preparation of Dye Solid Fine Particle Dispersion 6.0 kg of cyanine dye compound-1 and 3.0 kg of sodium p-dodecylbenzenesulfonate, 0.6 kg of surfactant Demol SNB manufactured by Kao Corporation, and antifoaming agent (product) Name: Surfynol 104E, manufactured by Nissin Chemical Co., Ltd.) 0.15 kg was mixed with distilled water to make a total liquid volume of 60 kg. The mixed solution was dispersed with 0.5 mm zirconia beads using a horizontal sand mill (UVM-2: manufactured by Imex Corporation).
The dispersion was dispersed until the ratio of the absorbance at 650 nm to the absorbance at 750 nm (D ₆₅₀ / D ₇₅₀ ) in the spectral absorption of the dispersion was 5.0 or more. The obtained dispersion was diluted with distilled water so that the concentration of the cyanine dye was 6% by mass, and was subjected to filter filtration (average pore diameter: 1 μm) for removal of dust and put to practical use.

3) Preparation of antihalation layer coating solution Keep the container at 40 ° C., add 37 g of gelatin with an isoelectric point of 6.6 (ABA gelatin manufactured by Nippi Co., Ltd.), 0.1 g of benzoisothiazolinone and water to add gelatin. Dissolved. Furthermore, 36 g of the dye solid fine particle dispersion, 73 g of the solid fine particle dispersion (a) of the base precursor, 43 mL SBR latex of 3% by weight aqueous sodium polystyrenesulfonate (styrene / butadiene / acrylic acid copolymer; mass ratio 68.3 / 28.7 / 3.0) 82 g of a 10% by mass solution was mixed to prepare an antihalation layer coating solution having a finished solution amount of 773 mL. The pH value of the finished liquid was 6.3.

4) Preparation of back surface protective layer coating solution Keep the container at 40 ° C., add 43 g of gelatin with an isoelectric point of 4.8 (PZ gelatin made by Miyagi Chemical Co., Ltd.), 0.21 g of benzoisothiazolinone and water. The gelatin was dissolved. Furthermore, 8.1 mL of 1 mol / L sodium acetate aqueous solution, 0.93 g of monodisperse poly (ethylene glycol dimethacrylate-co-methyl methacrylate) fine particles (average particle size 7.7 μm, particle size standard deviation 0.3 μm), liquid paraffin 5 g of 10 mass% emulsion, 10 g of 10 mass% emulsion of dipentaerythritol hexaisostearate, 10 mL of 5% aqueous solution of di (2-ethylhexyl) sodium sulfosuccinate, 17 mL of 3% aqueous sodium polystyrenesulfonate solution, 2.4 mL of a 2% by mass solution of a fluorosurfactant (F-1), 2.4 mL of a 2% by mass solution of a fluorosurfactant (F-2), an ethyl acrylate / acrylic acid copolymer (copolymerization mass) Ratio 96.4 / 3.6) A latex 20% by mass solution 30 mL was mixed. Immediately before coating, 50 mL of a 4% by weight aqueous solution of N, N-ethylenebis (vinylsulfone acetamide) was mixed to prepare a back surface protective layer coating solution having a finished liquid amount of 855 mL. The pH value of the finished liquid was 6.2.

5) Application of back layer On the back surface side of the undercoat support, the coating amount of the antihalation layer coating solution is 0.54 g / m ^2, and the coating amount of the back surface protective layer coating solution is 1 A simultaneous multi-layer coating was applied so as to be .85 g / m ² , followed by drying to prepare a back layer.

(Image forming layer, intermediate layer, and surface protective layer)
1. Preparation of coating materials 1) Silver halide emulsion << Preparation of silver halide emulsion 1 >>
To a solution of 1421 mL of distilled water, 3.1 mL of a 1% by mass potassium bromide solution was added, and a solution containing 3.5 mL of 0.5 mol / L sulfuric acid and 31.7 g of phthalated gelatin was stirred in a stainless steel reaction vessel. While maintaining the liquid temperature at 30 ° C., the solution A diluted with 92.2 mL of distilled water added to 22.22 g of silver nitrate, 15.3 g of potassium bromide and 0.8 g of potassium iodide in a distilled water volume of 97.4 mL The whole amount of the solution B diluted to 1 was added at a constant flow rate over 45 seconds. Thereafter, 10 mL of a 3.5% by mass aqueous hydrogen peroxide solution was added, and 10.8 mL of a 10% by mass aqueous solution of benzimidazole was further added. Further, a solution C in which distilled water was added to 51.86 g of silver nitrate and diluted to 317.5 mL, a solution D in which 44.2 g of potassium bromide and 2.2 g of potassium iodide were diluted with distilled water to a volume of 400 mL were added to solution C. Was added at a constant flow rate over 20 minutes, and solution D was added by the controlled double jet method while maintaining pAg at 8.1. The total amount of potassium hexachloroiridium (III) was added 10 minutes after the start of the addition of the solution C and the solution D so as to be 1 × 10 ⁻⁴ mol per mol of silver. Further, 5 seconds after the completion of the addition of the solution C, an aqueous solution of potassium iron (II) hexacyanide was added in an amount of 3 × 10 ⁻⁴ mol per mol of silver. The pH was adjusted to 3.8 using 0.5 mol / L sulfuric acid, 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.

The silver halide dispersion was maintained at 38 ° C. with stirring, 5 mL of a 0.34 mass% 1,2-benzisothiazolin-3-one methanol solution was added, and the temperature was raised to 47 ° C. after 40 minutes. 20 minutes after the temperature increase, sodium benzenethiosulfonate was added in a methanol solution to 7.6 × 10 ⁻⁵ mol per 1 mol of silver, and 5 minutes later, tellurium sensitizer C was added in a methanol solution to a ratio of 2. 9 × 10 ⁻⁴ mol was added and aged for 91 minutes. Thereafter, a methanol solution having a molar ratio of the spectral sensitizing dye A and the sensitizing dye B of 3: 1 was added in an amount of 1.2 × 10 ⁻³ mol as a total of the sensitizing dyes A and B per mol of silver. , N′-dihydroxy-N ″ -diethylmelamine in 1.3 mL of a 0.8 wt% methanol solution was added, and after an additional 4 minutes, 5-methyl-2-mercaptobenzimidazole was added to the methanol solution at a rate of 4.8 per mole of silver. × 10 ⁻³ mol, 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole in methanol solution to 5.4 × 10 ⁻³ mol and 1- (3-methyl) with respect to 1 mol of silver A silver halide emulsion 1 was prepared by adding 8.5 × 10 ⁻³ mol of ureidophenyl) -5-mercaptotetrazole in an aqueous solution to 1 mol of silver.

  The grains in the prepared silver halide emulsion were silver iodobromide grains containing 3.5 mol% of iodine having an average sphere equivalent diameter of 0.042 μm and a sphere equivalent diameter variation coefficient of 20%. The particle size and the like were determined from an average of 1000 particles using an electron microscope. The {100} face ratio of the particles was determined to be 80% using the Kubelka-Munk method.

<< Preparation of silver halide emulsion 2 >>
In the preparation of silver halide emulsion 1, the liquid temperature 30 ° C. at the time of grain formation was changed to 47 ° C., and solution B was changed to diluting 15.9 g of potassium bromide to a volume of 97.4 mL with distilled water, Solution D was changed to diluting 45.8 g of potassium bromide with distilled water to a volume of 400 mL, and the addition time of solution C was changed to 30 minutes to remove potassium hexacyanoiron (II) in the same manner. A silver halide emulsion 2 was prepared. Precipitation / desalting / washing / dispersion was carried out in the same manner as silver halide emulsion 1. Furthermore, the addition amount of tellurium sensitizer C is 1.1 × 10 ⁻⁴ mol per mol of silver, and the addition amount of methanol solution of 3: 1 in the molar ratio of spectral sensitizing dye A and spectral sensitizing dye B is silver. The total of sensitizing dye A and sensitizing dye B per mole is 7.0 × 10 ⁻⁴ mole, and 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole is added to 1 mole of silver. Same as Emulsion 1 except that 3.3 × 10 ⁻³ mol and 1- (3-methylureidophenyl) -5-mercaptotetrazole were changed to 4.7 × 10 ⁻³ mol added to 1 mol of silver. Spectral sensitization, chemical sensitization, and addition of 5-methyl-2-mercaptobenzimidazole and 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole were carried out to obtain silver halide emulsion 2. . The emulsion grains of the silver halide emulsion 2 were pure silver bromide cubic grains having an average sphere equivalent diameter of 0.080 μm and a sphere equivalent diameter variation coefficient of 20%.

<< Preparation of silver halide emulsion 3 >>
In the preparation of silver halide emulsion 1, silver halide emulsion 3 was prepared in the same manner except that the liquid temperature at the time of grain formation was changed from 30 ° C. to 27 ° C. Further, precipitation / desalting / washing / dispersion was performed in the same manner as silver halide emulsion 1. The molar ratio of spectral sensitizing dye A and spectral sensitizing dye B is 1: 1 as a solid dispersion (gelatin aqueous solution), and the addition amount is 6 × 10 ⁻ as the total of sensitizing dye A and sensitizing dye B per mole of silver. ³ moles, the amount of tellurium sensitizer C added was changed to 5.2 × 10 ⁻⁴ moles per mole of silver, and bromoauric acid was changed to 5 × 10 ⁻⁴ moles of silver 3 minutes after the addition of tellurium sensitizers. A silver halide emulsion 3 was obtained in the same manner as Emulsion 1 except that 2 × 10 ⁻³ mol of mol and potassium thiocyanate were added per mol of silver. The emulsion grains of the silver halide emulsion 3 were silver iodobromide grains containing 3.5 mol% of iodine having an average sphere equivalent diameter of 0.034 μm and a sphere equivalent diameter variation coefficient of 20%.

<< Preparation of mixed emulsion A for coating solution >>
70% by weight of silver halide emulsion 1, 15% by weight of silver halide emulsion 2 and 15% by weight of silver halide emulsion 3 were dissolved, and 7% by mole of silver in a 1% by weight aqueous solution of benzothiazolium iodide. × 10 ^-3 mol was added.
Furthermore, the amount of the one-electron oxidant produced by one-electron oxidation is 2 × 10 ⁻³ moles per mole of silver halide of each compound 1, 2, and 3 capable of emitting one electron or more. Added.
Adsorbing redox compounds 1 and 2 having an adsorbing group and a reducing group were added in an amount of 5 × 10 ⁻³ mol per mol of silver halide.

  Further, water was added so that the content of silver halide per 1 kg of the mixed emulsion for coating solution was 38.2 g as silver. 1- (3-Methylureidophenyl) -5-mercaptotetrazole was added so as to give 0.34 g per kg of the mixed emulsion for coating solution.

2) Preparation of fatty acid silver dispersion <Preparation of fatty acid silver dispersion>
Recrystallized behenic acid 88 kg, distilled water 422 L, 5 mol / L NaOH aqueous solution 49.2 L and t-butyl alcohol 120 L were mixed and stirred at 75 ° C. for 1 hour to react to obtain sodium behenate solution B. Separately, 206.2 L (pH 4.0) of an aqueous solution containing 40.4 kg of silver nitrate was prepared and kept warm at 10 ° C. A reaction vessel containing 635 L of distilled water and 30 L of t-butyl alcohol was kept at 30 ° C., and with sufficient stirring, the total amount of the previous sodium behenate solution B and the total amount of silver nitrate aqueous solution were kept at a constant flow rate for 93 minutes 15 Added over seconds and 90 minutes. At this time, only the silver nitrate aqueous solution is added for 11 minutes after the start of the addition of the aqueous silver nitrate solution, and then the addition of the sodium behenate solution B is started. After the addition of the aqueous silver nitrate solution is completed, only the sodium behenate solution B is added for 14 minutes and 15 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. The piping of the addition system of the sodium behenate solution B was prepared by keeping warm water by circulating hot water outside the double pipe so that the liquid temperature at the outlet of the addition nozzle tip was 75 ° C. Moreover, the piping of the addition system of the silver nitrate aqueous solution was kept warm by circulating cold water outside the double pipe. The addition position of the sodium behenate solution B and the addition position of the aqueous silver nitrate solution were arranged symmetrically with respect to the stirring axis, and were adjusted so as not to contact the reaction solution.

After completion of the addition of the sodium behenate solution B, the mixture was left stirring for 20 minutes at the same temperature, heated to 35 ° C. over 30 minutes, and then aged for 210 minutes. Immediately after completion of aging, the solid content was separated by centrifugal filtration, and the solid content was washed with water until the conductivity of filtered water reached 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 microscope photography, the average values were a = 0.21 μm, b = 0.4 μm, c = 0.4 μm, average aspect ratio 2.1, and equivalent sphere diameter. It was a crystal with a variation coefficient of 11% (a, b, and c are defined in the text).

  19.3 kg of polyvinyl alcohol (trade name: PVA-217) and water are added to a wet cake corresponding to a dry solid content of 260 kg to make a total amount of 1000 kg, and then slurried with a dissolver blade, and a pipeline mixer (manufactured by Mizuho Kogyo Co., Ltd.). : PM-10 type).

Next, the pre-dispersed stock solution is adjusted to a pressure of 1150 kg / cm ² in a disperser (trade name: Microfluidizer M-610, manufactured by Microfluidics International Corporation, using a Z-type interaction chamber) three times. Treatment gave a silver behenate dispersion. The cooling operation was carried out by installing a serpentine heat exchanger before and after the interaction chamber, and adjusting the temperature of the refrigerant to a dispersion temperature of 18 ° C.

3) Preparation of reducing agent dispersion << Preparation of reducing agent-1 dispersion >>
10 kg of water was added to 16 kg of a 10% by weight aqueous solution of reducing agent-1 (2,2′-methylenebis- (4-ethyl-6-tert-butylphenol)) and denatured polyvinyl alcohol (Kuraray Co., Ltd., Poval MP203). Add and mix well to make a slurry. This slurry was fed with a diaphragm pump, dispersed for 3 hours in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm, and then benzoisothiazolinone sodium salt 0. 2 g and water were added to prepare a reducing agent concentration of 25% by mass. This dispersion was heat-treated at 60 ° C. for 5 hours to obtain a reducing agent-1 dispersion. The reducing agent particles contained in the reducing agent dispersion thus obtained had a median diameter of 0.40 μm and a maximum particle diameter of 1.4 μm or less. The obtained reducing agent dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust and stored.

<< Preparation of Reducing Agent-2 Dispersion >>
10 masses of reducing agent-2 (6,6′-di-t-butyl-4,4′-dimethyl-2,2′-butylidenediphenol) and modified polyvinyl alcohol (Kuraray Co., Ltd., Poval MP203) 10 kg of water was added to 16 kg of% aqueous solution and mixed well to obtain a slurry. This slurry was fed with a diaphragm pump and dispersed for 3 hours 30 minutes in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm, and then benzoisothiazolinone sodium salt 0.2 g and water were added to prepare a reducing agent concentration of 25% by mass. This dispersion was heated at 40 ° C. for 1 hour, and then further heated at 80 ° C. for 1 hour to obtain a reducing agent-2 dispersion. The reducing agent particles contained in the reducing agent dispersion thus obtained had a median diameter of 0.50 μm and a maximum particle diameter of 1.6 μm or less. The obtained reducing agent dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust and stored.

4) Preparation of hydrogen bonding compound-1 dispersion 10 kg of hydrogen bonding compound-1 (tri (4-t-butylphenyl) phosphine oxide) and modified polyvinyl alcohol (Kuraray Co., Ltd., Poval MP203) 10 kg of water was added to 16 kg of the aqueous solution and mixed well to obtain a slurry. This slurry was fed with a diaphragm pump, and dispersed for 4 hours in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm. 2 g and water were added to prepare a hydrogen bonding compound concentration of 25% by mass. The dispersion was heated at 40 ° C. for 1 hour and then further heated at 80 ° C. for 1 hour to obtain a hydrogen bonding compound-1 dispersion. The hydrogen bonding compound particles contained in the hydrogen bonding compound dispersion thus obtained had a median diameter of 0.45 μm and a maximum particle diameter of 1.3 μm or less. The obtained hydrogen bonding compound dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust and stored.

5) Preparation of Development Accelerator-1 Dispersion 10 kg of Development Accelerator-1 and 20 kg of 10% by weight aqueous solution of modified polyvinyl alcohol (Kuraray Co., Ltd., Poval MP203) were added with 10 kg of water and mixed well. To make a slurry. This slurry was fed with a diaphragm pump and dispersed for 3 hours 30 minutes in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm, and then benzoisothiazolinone sodium salt 0.2 g and water were added to adjust the concentration of the development accelerator to 20% by mass to obtain a development accelerator-1 dispersion. The development accelerator particles contained in the development accelerator dispersion thus obtained had a median diameter of 0.48 μm and a maximum particle diameter of 1.4 μm or less. The obtained development accelerator dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust and stored.
6) Preparation of Dispersion of Development Accelerator-2 and Color Adjuster-1 The solid dispersion of Development Accelerator-2 and Color Adjuster-1 was also dispersed by the same method as Development Accelerator-1, each having 20 mass. %, 15% by mass of a dispersion liquid was obtained.

7) Preparation of polyhalogen compound << Preparation of organic polyhalogen compound-1 dispersion >>
10 kg of organic polyhalogen compound-1 (tribromomethanesulfonylbenzene), 10 kg of 20 wt% aqueous solution of modified polyvinyl alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.), 0.4 kg of 20 wt% aqueous solution of sodium triisopropylnaphthalenesulfonate, Then, 14 kg of water was added and mixed well to obtain a slurry. This slurry was fed with a diaphragm pump and dispersed for 5 hours in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm. 2 g and water were added to prepare an organic polyhalogen compound concentration of 26% by mass to obtain an organic polyhalogen compound-1 dispersion. The organic polyhalogen compound particles contained in the 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 through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust and stored.

<< Preparation of organic polyhalogen compound-2 dispersion >>
10 kg of an organic polyhalogen compound-2 (N-butyl-3-tribromomethanesulfonylbenzoamide), 20 kg of a 10% by weight aqueous solution of modified polyvinyl alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.), and 20 of sodium triisopropylnaphthalenesulfonate 0.4 kg of a mass% aqueous solution was added and mixed well to obtain a slurry. This slurry was fed with a diaphragm pump and dispersed for 5 hours in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm. 2 g and water were added to prepare an organic polyhalogen compound concentration of 30% by mass. This dispersion was heated at 40 ° C. for 5 hours to obtain an organic polyhalogen compound-2 dispersion. The organic polyhalogen compound particles contained in the polyhalogen compound dispersion thus obtained had a median diameter of 0.40 μm and a maximum particle diameter of 1.3 μm or less. The obtained organic polyhalogen compound dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust and stored.

8) Preparation of phthalazine compound-1 solution 8 kg of modified polyvinyl alcohol MP203 manufactured by Kuraray Co., Ltd. was dissolved in 174.57 kg of water, and then 3.15 kg of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate and phthalazine compound-1 ( 14.28 kg of a 70% by weight aqueous solution of 6-isopropylphthalazine) was added to prepare a 5% by weight solution of phthalazine compound-1.

9) Preparation of mercapto compound)
<< Preparation of Mercapto Compound-1 Aqueous Solution >>
7 g of mercapto compound-1 (1- (3-sulfophenyl) -5-mercaptotetrazole sodium salt) was dissolved in 993 g of water to obtain a 0.7% by mass aqueous solution.

<< Preparation of Mercapto Compound-2 Aqueous Solution >>
20 g of mercapto compound-2 (1- (3-methylureidophenyl) -5-mercaptotetrazole) was dissolved in 980 g of water to obtain a 2.0 mass% aqueous solution.

10) Preparation of SBR latex liquid In a polymerization kettle of a gas monomer reactor (TAS-2J type manufactured by Pressure Glass Industrial Co., Ltd.), 287 g of distilled water and a surfactant (Pionin A-43-S (manufactured by Takemoto Yushi Co., Ltd.)) ): Solid content 48.5% by mass) 7.73 g, 1 mol / L, NaOH 14.06 mL, ethylenediaminetetraacetic acid tetrasodium salt 0.15 g, styrene 255 g, acrylic acid 11.25 g, tert-dodecyl mercaptan 3.0 g The reaction vessel was sealed and stirred at a stirring speed of 200 rpm. After degassing with a vacuum pump and repeating nitrogen gas replacement several times, 108.75 g of 1,3-butadiene was injected and the internal temperature was raised to 60 ° C. A solution prepared by dissolving 1.875 g of ammonium persulfate in 50 mL of water was added thereto and stirred as it was for 5 hours. The temperature was further raised to 90 ° C., and the mixture was stirred for 3 hours. After completion of the reaction, the internal temperature was lowered to room temperature, and then Na ⁺ ion: NH ₄ ⁺ ion = 1: 1 using 1 mol / L NaOH and NH ₄ OH. Addition treatment was performed so that the molar ratio was 5.3 (molar ratio), and the pH was adjusted to 8.4. Thereafter, the mixture was filtered through a polypropylene filter having a pore size of 1.0 μm to remove foreign substances such as dust and stored, and 774.7 g of SBR latex TP-1 was obtained. When the halogen ions were measured by ion chromatography, the chloride ion concentration was 3 ppm. As a result of measuring the concentration of the chelating agent by high performance liquid chromatography, it was 145 ppm.

  The latex has a gelation rate of 73% by mass, an average particle size of 90 nm, Tg = 17 ° C., a solid content concentration of 44% by mass, an equilibrium water content of 0.6% by mass at 25 ° C. and 60% RH, and an ionic conductivity of 4.80 mS / cm (Ion conductivity was measured at 25 ° C. using a conductivity meter CM-30S manufactured by Toa Radio Industry Co., Ltd.).

2. Preparation of coating solution

1) Preparation of Image Forming Layer Coating Liquids 1 to 5 1000 g of the fatty acid silver dispersion obtained above, 135 mL of water, dye (the present invention and comparative dye and pigment were added as shown in Table 3), organic poly 25 g of halogen compound-1 dispersion, 39 g of organic polyhalogen compound-2 dispersion, 171 g of phthalazine compound-1 solution, 1060 g of SBR latex liquid, 77 g of reducing agent-1 dispersion, 77 g of reducing agent-2 dispersion, hydrogen bonding compound -1 dispersion 22g, development accelerator-1 dispersion 4.8g, development accelerator-2 dispersion 5.2g, color tone modifier-1 dispersion 2.1g, mercapto compound-2 aqueous solution 8mL, Immediately before coating, 140 g of silver halide mixed emulsion A was added and mixed well, and the image forming layer coating solution was directly fed to the coating die and coated.
The viscosity of the image forming layer coating solution was 35 [mPa · s] at 40 ° C. (No. 1 rotor, 60 rpm) as measured with a B-type viscometer of Tokyo Keiki.
The viscosity of the coating solution at 38 ° C. using a Haake RheoStress RS150 is 38, 49, 48, 34, 25 [mPa · s] at shear rates of 0.1, 1, 10, 100, 1000 [1 / second], respectively. s].

  The amount of zirconium in the coating solution was 0.30 mg per 1 g of silver.

2) Preparation of intermediate layer A coating solution 1000 g of polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.), 27 mL of 5% by weight aqueous solution of di (2-ethylhexyl) sodium sulfosuccinate, methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / Acrylic acid copolymer (copolymerization mass ratio 57/8/28/5/2) 19 mass% latex 4200 mL and 27% 5 wt% aqueous solution of aerosol OT (American Cyanamid Co., Ltd.) Water was added to 135 mL of a 20% by mass aqueous solution of ammonium salt to a total amount of 10000 g, and adjusted with NaOH to a pH of 7.5 to obtain an intermediate layer coating solution, so as to be 8.9 mL / m ^2. The solution was fed to the coating die.
The viscosity of the coating solution was 58 [mPa · s] at a B-type viscometer of 40 ° C. (No. 1 rotor, 60 rpm).

3) Preparation of intermediate layer B coating solution 100 g of inert gelatin and 10 mg of benzoisothiazolinone were dissolved in 840 mL of water, and a methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer mass ratio 57/8). / 28/5/2) Latex 19% liquid 180g, phthalic acid 15% methanol solution 46mL, sulfosuccinic acid di (2-ethylhexyl) sodium salt 5% aqueous solution 5.4mL was added and mixed, Immediately before coating, 40 mL of 4% by mass chromium alum mixed with a static mixer was fed to the coating die so that the amount of the coating solution was 26.1 mL / m ² .
The viscosity of the coating solution was 20 [mPa · s] at a B-type viscometer of 40 ° C. (No. 1 rotor, 60 rpm).

4) Preparation of outermost layer coating solution << Preparation of outermost layer coating solution-1 >>
100 g of inert gelatin and 10 mg of benzoisothiazolinone are dissolved in 800 mL of water, 40 g of a 10% by weight emulsion of liquid paraffin, 40 g of a 10% by weight emulsion of dipentaerythrityl hexaisostearate, methyl methacrylate / styrene / butyl acrylate / hydroxyethyl Methacrylate / acrylic acid copolymer (copolymerization mass ratio 57/8/28/5/2) Latex 19% by weight solution 180g, phthalic acid 15% by weight methanol solution 40mL, Fluorosurfactant (F-1) 1 5.5 mL of mass% solution, 5.5 mL of 1 mass% aqueous solution of fluorosurfactant (F-2), 28 mL of 5 mass% aqueous solution of di (2-ethylhexyl) sodium sulfosuccinate, polymethyl methacrylate fine particles (Average particle size 0.7μm, volume weighted average 30%) 4g, polymethyl methacrylate fine particles (mean particle size 3.6 [mu] m, a mixture of distribution 60%) 21g of the volume weighted average surface protective layer coating solution, a coating die so that 8.3 mL / m ² The solution was sent to.
The viscosity of the coating solution was 19 [mPa · s] at a B-type viscometer of 40 ° C. (No. 1 rotor, 60 rpm).

<< Preparation of Outermost Layer Coating Solution-2-5 >>
In the preparation of the outermost layer coating solution-1, inert gelatin and methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymerization mass ratio 57/8/28/5/2) latex were used. Was changed to the latex polymer shown in Table 3 to prepare outermost layer coating solutions -2 to 5.

3. Preparation of photothermographic material 1) Preparation of photothermographic materials 1 to 17 The image forming layer coating solution, the intermediate layer A coating solution, the intermediate layer B coating solution, and the outermost layer coating solution are formed on the surface opposite to the back surface from the undercoat. Samples of the photothermographic material were prepared in the order of simultaneous multilayer coating by the slide bead coating method. At this time, the image forming layer and the intermediate layer coating solution A were adjusted to 31 ° C., the intermediate layer coating solution B was adjusted to 36 ° C., and the outermost layer coating solution was adjusted to 37 ° C.
Table 3 shows combinations of coating solutions for each layer.
The coating amount (g / m ² ) of each compound in the image forming layer at this time is as follows.

Organic silver salt 4.88
Pigment (CI Pigment Blue 60) 0.0324
Polyhalogen compound-1 0.108
Polyhalogen compound-2 0.225
Phthalazine Compound-1 0.161
SBR latex 8.73
Reducing agent-1 0.36
Reducing agent-2 0.36
Hydrogen bonding compound-1 0.522
Development accelerator-1 0.019
Development accelerator-2 0.016
Color tone adjusting agent-1 0.006
Mercapto Compound-1 0.0018
Mercapto compound-2 0.0108
Silver halide (as Ag) 0.09

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 mm to 0.30 mm, and the pressure in the decompression chamber was set to be 196 Pa to 882 Pa lower than the atmospheric pressure. The support was neutralized with an ion wind before coating.
In the subsequent chilling zone, the coating liquid is cooled with a wind at a dry bulb temperature of 10 ° C. to 20 ° C., then transported in a non-contact manner, and dried at a dry bulb temperature of 23 ° C. to 45 ° C. It dried with the drying wind of 15 degreeC and the wet-bulb temperature of 15 to 21 degreeC.
After drying, the humidity was adjusted at 25 ° C. and humidity of 40% RH to 60% RH, and then the film surface was heated to 70 ° C. to 90 ° C. After heating, the film surface was cooled to 25 ° C.
The photothermographic material thus prepared had a Beck smoothness of 550 seconds on the image forming layer surface side and 130 seconds on the back surface. Further, the pH of the film surface on the image forming layer surface side was measured and found to be 6.0.

  The chemical structures of the compounds used in the examples of the present invention are shown below.

4). Evaluation of photographic performance 1) Preparation Each sample was cut into half-cut size (43 cm length x 35 cm width), packaged in the following packaging materials in an environment of 25 ° C. and 50% RH, stored at room temperature for 2 weeks, and then Was evaluated.
Laminate film in which PET 10 μm / PE 12 μm / aluminum foil 9 μm / Ny 15 μm / polyethylene 50 μm containing 3% by mass of carbon is laminated:
Oxygen permeability: 0.02 mL / atm · m ² · 25 ° C · day;
Moisture permeability: 0.10 g / atm · m ² · 25 ° C · day.

2) Exposure of photosensitive material and thermal development Each sample was exposed and thermally developed (107 ° C-121 ° C) with a dry laser imager DRYPIX7000 (mounted with a 660 nm semiconductor laser with a maximum output of 50 mW (IIIB)). A total of 14 seconds with three panel heaters set to −121 ° C.), and the obtained image was evaluated with a densitometer.

3) Evaluation items (spectral absorption spectrum)
The absorption spectrum of the unexposed part sample was measured with a spectrophotometer, and each absorption at 550 nm and 660 nm was read.
(Color tone)
The unexposed part after heat development was subjected to sensory evaluation by 10 evaluators. The evaluation criteria are shown below. The score with the most votes among the 10 evaluation results was taken as the score of the sample.
A: Low density, high clearness, and preferable as a transmission photographic material.
B: Although there is some color, it is at a level that does not cause a problem as a transmission photographic material.
C: Strongly tinted and at a level causing problems as a transmission photographic material.

(Sharpness)
In the same manner as the exposure process described above, however, a rectangular wave pattern was exposed and heat development was performed in the same manner. The value obtained by dividing the density difference of the rectangular wave pattern with a spatial frequency of 5 lines / mm by the density difference of 0.01 lines / mm is A, and the value A of the sample 1 is used as a reference to the relative value (% ) And defined as sharpness. The higher the numerical value of sharpness, the better.

(Image preservation)
The unexposed sample after heat development was stored for one week as a bare sample in a temperature and humidity environment of 40 ° C. and 90% RH as a compulsory condition assuming storage in a high-humidity heat environment.
Before and after storage in an environment of 40 ° C. and 90% RH, the transmitted color of the sample film was measured according to the method described in JIS Z8722: 2000. Here, L ^* , a ^* , and b ^* in the CIELAB color space were calculated based on the F5 fluorescent light source as the observation light source.
Each change of a ^* and b ^* values before and after storage under high humidity heat was set as Δa ^* and Δb ^* , and the following D values were obtained.
D = (Δa ^{* 2} + Δb ^{* 2} ) ^1/2
This numerical value D represents the degree of change in color tone before and after storage under high humidity heat, and it can be said that the smaller this value, the better the image storability.

4) Evaluation results The results obtained are shown in Table 4.
The sample of the present invention has good color tone and improved sharpness. Furthermore, there was little change in color tone and good image storage stability when stored under high heat and humidity.

Example 2
In sample 10 of Example 1, compound No. 1 of general formula (PC-1) was used. 11 No. 28,
No. 92, no. 116, and no. Instead of 137, samples 21 to 24 were produced.
As a result of evaluation in the same manner as in Example 1, all the samples of the present invention showed good results as in Example 1.

Example 3
<Examples of aggregate dyes>
In Sample 15 of Example 1, Dispersion 101, which is an aggregate dye described in JP-A No. 2003-43628, was used as Dispersion 102, Dispersion 103, and JP-A No. 2003 described in JP-A No. 2003-43628. Samples 31 to 34 were prepared in place of the associated dye dispersion 107 and dispersion 109 described in No. -84395.
When any known associative dye was used, as in Example 1, the image storage stability was good by using 50% or more of latex in the outermost layer.

Example 4
In the sample 10 of Example 1, the gelling agent κ-carrageenan was added to the outermost layer so as to be 0.1 g / m ² , thereby preparing the sample 41. The coated surface has been improved. Further, as a result of evaluating the photographic performance in the same manner as in Example 1, the image storability was as good as that of Sample 10.

Claims (20)

A photothermographic material having an image forming layer containing at least a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent and a binder on at least one surface of a support,
1) containing a dye having a full width at half maximum of 100 nm or less,
2) The photothermographic material, wherein 50% by mass or more of the outermost binder on the surface having the dye is a polymer latex.   2. The photothermographic material according to claim 1, wherein the dye is contained in a back layer on a surface opposite to the image forming layer of the support.   2. The photothermographic material according to claim 1, wherein the dye is contained in a layer on the same side as the image forming layer of the support.   4. The photothermographic material according to claim 3, wherein the image forming layer contains the dye.   5. The photothermographic material according to claim 4, wherein 50% by mass or more of the binder of the image forming layer is a polymer latex.   The photothermographic material according to claim 1, wherein the dye is a water-soluble dye. The photothermographic material according to claim 6, wherein the water-soluble dye is a metal phthalocyanine dye represented by the general formula (PC-1):

(Wherein, M is ^{.R 1, R 4, R 5} , R 8, R 9, R 12, R 13, and R ¹⁶ are each independently a hydrogen atom, a substituent represents a metal atom, R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ¹⁶ are electron withdrawing groups R ² , R ³ , R ⁶ , R ⁷ , R ¹⁰ , R ¹¹ , R ¹⁴ , and R ¹⁵ each independently represents a hydrogen atom or a substituent. In the general formula (PC-1), at least one of R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ¹⁶ is a group represented by the general formula (II). The photothermographic material according to claim 7, wherein:

(In the formula, L ¹ is ^** -SO _2- ^* , ^** -SO _3- ^* , ^** -SO ₂ NR _N- ^* , ^** -SO- ^* , ^** -CO- ^* , ^** - _{^{CONR N - *, ** -COO- *}} , ** -COCO- *, ** -COCO 2 - *, or ^** -COCONR _N -. ^{*, **} denotes a bond with a phthalocyanine skeleton at this position representing the , * Indicates bonding with R ¹⁷ at this position, and R _N represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, a sulfonyl group, or a sulfamoyl group. R ¹⁷ represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group. In the general formula (PC-1), R ² , R ³ , R ⁶ , R ⁷ , R ¹⁰ , R ¹¹ , R ¹⁴ , and R ¹⁵ are hydrogen atoms, and R ¹ , R ⁴ , R ⁵ , R ^{8, R 9, R 12,} R 13, photothermographic material according to claim 8, wherein at least one R ¹⁶ is a group represented by the general formula (II). In the general formula (PC-1), four or more of R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ , and R ¹⁶ are represented by the general formula (II). 10. The photothermographic material according to claim 9, wherein the photothermographic material is a group.   7. The photothermographic material according to claim 6, wherein the water-soluble dye is an associative dye.   12. The photothermographic material according to claim 11, wherein the associative dye is a polymethine dye.   13. The photothermographic material according to claim 12, wherein the polymethine dye is a cyanine dye or an oxonol dye.   13. The photothermographic material according to claim 1, wherein the outermost polymer latex has a Tg of −20 ° C. or more and 70 ° C. or less.   The photothermographic material according to claim 1, wherein the outermost layer contains a gelling agent.   The photothermographic material according to claim 3, further comprising a non-photosensitive intermediate layer between the outermost layer and the image forming layer. The non-photosensitive intermediate layer comprises at least two layers, and at least 50% by mass or more of the binder of the non-photosensitive intermediate layer A adjacent to the image forming layer is a monomer component represented by the following general formula (M). The photothermographic material according to claim 16, wherein the photothermographic material is a polymer latex having:
Formula ^{_{(M) CH 2 = CR 01}} -CR 02 = CH 2
(In the formula, R ⁰¹ and R ⁰² are groups selected from a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a halogen atom, and a cyano group). 18. The photothermographic material according to claim 17, wherein R ⁰¹ and R ^{02 in} the general formula (M) are both hydrogen atoms, or one is a hydrogen atom and the other is a methyl group.   The non-photosensitive intermediate layer B adjacent to the outermost layer in the at least two non-photosensitive intermediate layers is characterized in that 50% by mass or more of the binder is a hydrophilic polymer derived from animal protein. The photothermographic material according to claim 18.   The photothermographic material according to claim 19, wherein the hydrophilic protein derived from animal protein is gelatin.