JP4284007B2 - Photothermographic material and image forming method using the photothermographic material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photothermographic material, and more particularly to a photothermographic material suitable for medical diagnosis, industrial photography, printing, and COM, and an image forming method using the photothermographic material.
[0002]
[Prior art]
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, thermal development 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 having high resolution and sharpness. There is a need for techniques relating to photosensitive materials. According to these photothermographic materials, it is possible to supply a customer with a photothermographic processing system that does not require solution processing chemicals and that is simpler and does not impair the environment.
[0003]
There are similar requirements in the field of general image forming 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.
[0004]
On the other hand, thermal imaging systems using organic silver salts are disclosed in, for example, US 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, page 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 a photosensitive 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. It is disclosed in many documents including US Pat. No. 2,910,377 and Japanese Patent Publication No. 43-4924.
[0005]
Laser light is used as an exposure light source in thermal image forming systems using organic silver salts that have been used in medical image output systems due to recent technological innovation and digitalization trends. Since the laser power can be obtained at low cost, a semiconductor laser having an infrared wavelength is often used.
[0006]
In a medical field such as an emergency hospital, a rapid output result of a medical image is required, and therefore it is desired to shorten the heat development time. Further, since it is desired that a low-power laser is used in order to enhance the stability of the laser exposure apparatus, a technique for enhancing the sensitivity of the photosensitive material is required.
[0007]
Furthermore, there is a drawback that the stability of the output image at the time of continuous output is low, and improvement is desired.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to solve the above-described problems of the prior art. More specifically, the present invention relates to a photothermographic material for use in medical images or photoengraving, etc., which is a high-sensitivity photothermographic material intended to shorten the heat development time, and uses the same. An object of the present invention is to provide an image forming method for stabilizing an output image at the time of continuous output.
[0009]
[Means for Solving the Problems]
As a result of diligent studies to solve the above-mentioned problems, the present inventor can produce a preferable photothermographic material exhibiting an expected effect by using a specific reducing agent and a specific compound in combination. As a result, the present invention has been solved.
That is, the present invention
[0010]
<1> In a photothermographic material containing at least one type of photosensitive silver halide, non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one side of the support,
Containing at least one polyphenol compound represented by the following general formula (I) as the reducing agent,
Containing at least one compound represented by the following general formula (II),
The photothermographic material is characterized in that the photosensitive silver halide is infrared sensitized.
[0011]
[Chemical 3]
[0012]
(In the general formula (I), R¹¹And R^{11 '}Each independently represents an alkyl group having 1 to 20 carbon atoms. R¹²And R^{12 '}Each independently represents a hydrogen atom or a substituent that can be substituted on the benzene ring. L is a -S- group or -CHR.¹³-Represents a group. R¹³Represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. X¹And X^{1 '}Each independently represents a hydrogen atom or a group capable of substituting for a benzene ring. )
[0013]
[Formula 4]
[0014]
(In the general formula (II), Q¹Is NHNH-R¹Combine withA pyrimidine ring or a ring in which a benzene ring or an unsaturated heterocycle is fused to a pyrimidine ringRepresents R¹IsReplaceCarbamoylGrouptableThe)
[0015]
<2>Q1 represents a quinazoline ring<2> The photothermographic material according to <1>.
[0016]
<3>AboveIn the compound represented by the general formula (II), R ¹ -CO-NH-R¹A substituted carbamoyl group represented by ′, and R¹The photothermographic material according to <1> or <2>, wherein 'represents an alkyl group having 1 to 10 carbon atoms or an aryl group.
[0017]
<4> The photothermographic material according to any one of <1> to <3>, wherein the compound represented by formula (I) has a molecular weight of 350 or less.
[0018]
<5> An image forming method, wherein the photothermographic material according to any one of <1> to <4> is exposed with a laser beam having an exposure wavelength of 750 nm to 1400 nm.
[0019]
<6> An image forming method, wherein the photothermographic material according to any one of <1> to <4> is subjected to heat development processing with a heat development processing time of 3 seconds to 15 seconds.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
The non-photosensitive organic silver salt used in the present invention will be described.
The photothermographic material of the present invention contains a non-photosensitive organic silver salt (hereinafter sometimes simply referred to as “organic silver salt”). Organic silver salts are relatively stable to light, but when heated to 80 ° C. or higher in the presence of an exposed photocatalyst (such as a latent image of photosensitive silver halide) and a reducing agent. A silver salt that forms a silver image. The organic silver salt may be any organic material containing a source capable of reducing silver ions. 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 It is described in Japanese Patent Publication No. 0968212A1, Japanese Patent Application Laid-Open No. 11-349591, Japanese Patent Application Laid-Open No. 2000-7683, Japanese Patent Application Laid-Open No. 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 organic silver salt include silver behenate, silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, and a mixture thereof. In the present invention, among these organic silver salts, it is preferable to use organic acid silver having a silver behenate content of 75 mol% or more.
[0021]
The shape of the organic silver salt that can be used in the present invention is not particularly limited, and may be a needle shape, a rod shape, a flat plate shape, or a flake shape, preferably a needle shape or flake shape, and particularly preferably a flake shape.
In the present specification, the scaly organic silver salt is defined as follows. The organic acid silver salt was observed with an electron microscope, the shape of the organic acid silver salt particle was approximated to a rectangular parallelepiped, and the sides of the rectangular parallelepiped were designated a, b, and c from the shortest side (c was the same as b). Then, the shorter numerical values a and b are calculated, and x is obtained as follows.
x = b / a
[0022]
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 20 ≧ x (average) ≧ 2.0. Incidentally, the needle shape is 1 ≦ x (average) <1.5.
[0023]
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 0.23 μm, more preferably 0.1 μm or more and 0.20 μm or less. The average of c / b is preferably 1 or more and 6 or less, more preferably 1.05 or more and 4 or less, further preferably 1.1 or more and 3 or less, and particularly preferably 1.1 or more and 2 or less.
[0024]
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.
[0025]
Known methods and the like can be applied to the production and dispersion method of the organic acid silver used in the present invention. For example, Japanese Patent Application Laid-Open No. 10-62899, European Patent Publication No. 0803763A1, European Patent Publication No. 0968212A1, Japanese Patent Application Laid-Open No. 11-349591, Japanese Patent Application Laid-Open No. 2000-7683, Japanese Patent Application No. 2000-72711, Japanese Patent Application No. 2000-72711. 11-348228-30, 11-203413, Japanese Patent Application Nos. 2000-90093, 2000-195621, 2000-191226, 2000-213813, 2000-214155, 2000-191226, etc. Can be helpful.
[0026]
In addition, when the photosensitive silver salt is allowed to coexist at the time of dispersion of the organic silver salt, the fog is increased 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 0.1 mol% or less with respect to 1 mol of the organic acid silver salt in the liquid, and positive addition of the photosensitive silver salt is performed. There is nothing.
[0027]
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 to 30 mol%, more preferably 3 to 20 mol%, particularly preferably 5 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.
[0028]
The organic silver salt of the present invention can be used in a desired amount, but the amount of silver is 0.1 to 5 g / m.²Is more preferable, and more preferably 1 to 3 g / m.²It is.
[0029]
The reducing agent for silver ions used in the present invention will be described.
The photothermographic material of the present invention contains a reducing agent for silver ions. The reducing agent for silver ions may be any substance (preferably an organic substance) that reduces silver ions to metallic silver. 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 bisphenol reducing agent, and is represented by a compound represented by the following general formula (I).
[0030]
[Chemical formula 5]
[0031]
In general formula (I), R¹¹And R^{11 '}Each independently represents an alkyl group having 1 to 20 carbon atoms. R¹²And R^{12 '}Each independently represents a hydrogen atom or a substituent that can be substituted on the benzene ring. L is a -S- group or -CHR.¹³-Represents a group. R¹³Represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. X¹And X^{1 '}Each independently represents a hydrogen atom or a group capable of substituting for a benzene ring.
[0032]
The general formula (I) will be described in detail.
R¹¹And R^{11 '}May have a substituent. The substituent is not particularly limited, but aryl group, hydroxy group, alkoxy group, aryloxy group, alkylthio group, arylthio group, acylamino group, sulfonamido group, sulfonyl group, phosphoryl group, acyl group, carbamoyl group An ester group, a halogen atom and the like are preferable.
[0033]
R¹¹And R^{11 '}Is preferably a secondary or tertiary alkyl group having 3 to 15 carbon atoms, and more preferably a tertiary alkyl group having 4 to 12 carbon atoms. Specific examples include isopropyl group, isobutyl group, t-butyl group, t-amyl group, t-octyl group, cyclohexyl group, cyclopentyl group, 1-methylcyclohexyl group, 1-methylcyclopropyl group and the like. A t-butyl group, a t-amyl group, and a 1-methylcyclohexyl group are preferable, and a t-butyl group is more preferable.
[0034]
R¹²And R^{12 '}Are each independently a hydrogen atom or a substituent that can be substituted on a benzene ring, and X¹And X^{1 '}Each independently represents a hydrogen atom or a group capable of substituting for a benzene ring. The group that can be substituted on the benzene ring is preferably an alkyl group, an aryl group, a halogen atom, an alkoxy group, or an acylamino group.
[0035]
R¹²And R^{12 '}As, a C1-C20 alkyl group is preferable. Specifically, methyl group, ethyl group, propyl group, butyl group, isopropyl group, t-butyl group, t-amyl group, cyclohexyl group, 1-methylcyclohexyl group, benzyl group, methoxymethyl group, methoxyethyl group, etc. A methyl group, an ethyl group, a propyl group, an isopropyl group, and a t-butyl group are more preferable.
X¹And X^{1 '}Is preferably a hydrogen atom, a halogen atom or an alkyl group, more preferably a hydrogen atom.
[0036]
L is a -S- group or -CHR.¹³-Represents a group, -CHR¹³-Is preferred.
R¹³Represents a hydrogen atom or an alkyl group which may have a substituent having 1 to 20 carbon atoms. Specific examples of the substituent of the alkyl group include a halogen atom, an alkoxy group, an alkylthio group, an aryloxy group, an arylthio group, an acylamino group, a sulfonamide group, a sulfonyl group, a phosphoryl group, an oxycarbonyl group, a carbamoyl group, a sulfamoyl group, and the like. Is mentioned. R¹³Specific examples of when is an alkyl group include methyl, ethyl, propyl, butyl, heptyl, undecyl, isopropyl, 1-ethylpentyl, 2,4,4-trimethylpentyl, and the like. Can be mentioned.
[0037]
R above¹³Is preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. Specifically, a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, and a 2,4,4-trimethylpentyl group are preferable, and a hydrogen atom, a methyl group, a propyl group, and an isopropyl group are more preferable.
[0038]
R¹³Is a hydrogen atom, R¹²And R^{12 '}Is preferably an alkyl group having 2 to 5 carbon atoms, more preferably an ethyl group or a propyl group, and most preferably an ethyl group.
On the other hand, R¹³Is a primary or secondary alkyl group having 1 to 8 carbon atoms, R¹²And R¹²'Is preferably a methyl group. In this case, R¹³The primary or secondary alkyl group having 1 to 8 carbon atoms is preferably a methyl group, an ethyl group, a propyl group or an isopropyl group, and more preferably a methyl group, an ethyl group or a propyl group.
[0039]
R¹¹, R^{11 '}, R¹², R^{12 '}Are all methyl groups, R¹³Is preferably a secondary alkyl group. In this case R¹³As the secondary alkyl group, isopropyl group, isobutyl group, and 1-ethylpentyl group are preferable, and isopropyl group is more preferable.
[0040]
Specific examples of the compound represented by formula (I), which is the reducing agent of the present invention, are shown below, but the present invention is not limited thereto.
[0041]
[Chemical 6]
[0042]
[Chemical 7]
[0043]
In the present invention, the amount of the compound represented by the general formula (I) is 0.01 to 5.0 g / m.²Is preferably 0.1 to 3.0 g / m.²More preferably, it is contained in an amount of 5 to 50% by mole, more preferably 10 to 40% by mole, based on 1 mole of silver on the surface having the image forming layer.
Further, the compound represented by the general formula (I) is preferably contained in the image forming layer.
[0044]
The molecular weight of the compound represented by the general formula (I) is preferably 350 or less, more preferably 300 or less. When the molecular weight of the compound is 350 or less, the improvement in sensitivity becomes more remarkable in a short development processing time.
[0045]
The compound represented by formula (I) 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 emulsifying dispersion methods include dissolving oil using an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, or an auxiliary solvent such as ethyl acetate or cyclohexanone, and mechanically emulsifying the dispersion. The method of producing is mentioned.
[0046]
As the solid fine particle dispersion method, the powder of the compound represented by the general formula (I) is dispersed in an appropriate solvent such as water by a ball mill, a colloid mill, a vibrating ball mill, a sand mill, a jet mill, a roller mill, or an ultrasonic wave. And a method of preparing a solid dispersion. 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. The aqueous dispersion can contain a preservative (eg, benzoisothiazolinone sodium salt).
[0047]
  In the present invention, a reducing compound represented by the above general formula (II) is further contained.
  The general formula (II) will be described in detail.
  The reducing compound represented by the general formula (II) is a developing agent collectively referred to as a hydrazine developing agent. Where Q¹Is NHNH-R¹Combine withA pyrimidine ring or a ring in which a benzene ring or an unsaturated heterocycle is fused to a pyrimidine ringRepresents R¹IsReplaceCarbamoylGroupTo express.
[0049]
  Q above ¹ RepresentsThe ring may have a substituent, and when it has 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 listedThe
[0050]
R¹The carbamoyl group represented by these has preferable C1-C50, and C6-C40 is more preferable. Specifically, unsubstituted carbamoyl group, methylcarbamoyl group, N-ethylcarbamoyl group, N-propylcarbamoyl group, N-sec-butylcarbamoyl group, N-octylcarbamoyl group, N-cyclohexylcarbamoyl group, N-tert- Butylcarbamoyl group, N-dodecylcarbamoyl group, N- (3-dodecyloxypropyl) carbamoyl group, N-octadecylcarbamoyl group, N- {3- (2,4-tert-pentylphenoxy) propyl} carbamoyl group, N- (2-hexyldecyl) carbamoyl group, N-phenylcarbamoyl group, N- (4-dodecyloxyphenyl) carbamoyl group, N- (2-chloro-5-dodecyloxycarbonylphenyl) carbamoyl group, N-naphthylcarbamoyl group, N-3-pyridylka Bamoiru group, N- benzylcarbamoyl group.
[0056]
  Q ¹ TheLimidine ring, MaOrPyrimidineA ring fused with a benzene ring or an unsaturated heterocycleTheQ¹Is a quinazoline ringPreferGood. Q¹Preferably has at least one electron-withdrawing substituent. Preferred substituents include fluoroalkyl groups (for example, trifluoromethyl group, pentafluoroethyl group, 1,1-difluoroethyl group, difluoromethyl group, fluoromethyl group, heptafluoropropyl group, pentafluorophenyl group), cyano Group, halogen atom (fluoro, chloro, bromo, iodo), acyl group, alkoxycarbonyl group, carbamoyl group, alkylsulfonyl group, arylsulfonyl group, and trifluoromethyl group is particularly preferable.
[0057]
  R¹ Is preferably-CO-NH-R¹Substituted carbamoyl group represented byTheR¹'Is an alkyl or aryl group having 1 to 10 carbon atomsIs.
  Specific examples of the reducing compound represented by formula (II) are shown below, but the compounds used in the present invention are not limited to these specific examples.
[0060]
[Chemical Formula 10]
[0061]
Embedded image
[0062]
Embedded image
[0068]
[Table 1]
[0069]
[Table 2]
[0070]
[Table 3]
[0071]
[Table 4]
[0072]
Embedded image
[0074]
Synthesis of the reducing compound represented by the general formula (II) is described in JP-A Nos. 9-152702, 8-286340, 9-152700, 9-152701, 9-152703. It can implement according to the method as described in gazette and the 9-152704 gazette.
The amount of the reducing compound represented by the general formula (II) is wide, but is preferably 0.01 to 100 mol times, more preferably 0.1 to 10 mol times with respect to silver ions.
The reducing compound represented by the general formula (II) may be added to the coating solution by any method such as a solution, powder, solid fine particle dispersion, emulsion, oil protect dispersion. The solid fine particle dispersion is performed by a known finer means (for example, ball mill, vibrating ball mill, sand mill, colloid mill, jet mill, roller mill, etc.). A dispersion aid may be used when dispersing the solid fine particles.
[0075]
The compounds of the general formulas (I) and (II) are preferably contained in an image forming layer containing an organic silver salt, but one is contained in an image forming layer and the other is contained in a non-image forming layer adjacent thereto. Alternatively, both may be included in the non-image forming layer. Further, when the image forming layer is composed of a plurality of layers, they may be contained in separate layers.
[0076]
In the photothermographic material of the present invention, a phenol derivative represented by the formula (A) described in Japanese Patent Application No. 11-73951 is preferably used as a development accelerator.
[0077]
When the reducing agent in the present invention has an aromatic hydroxyl group (—OH), particularly in the case of the aforementioned bisphenols, a non-reducing compound having a group capable of forming a hydrogen bond with these groups It is preferable to use together. 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 (A).
[0078]
Embedded image
[0079]
R in the general formula (A)^{twenty one}~ R^{twenty three}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 unsubstituted or may have a substituent. R^{twenty one}~ R^{twenty three}In the case where has a substituent, the substituent is a halogen atom, alkyl group, aryl group, alkoxy group, amino group, acyl group, acylamino group, alkylthio group, arylthio group, sulfonamido group, acyloxy group, oxycarbonyl group, carbamoyl Group, sulfamoyl group, sulfonyl group, phosphoryl group and the like. Preferred as substituents are alkyl groups or aryl groups such as methyl group, ethyl group, isopropyl group, t-butyl group, t-octyl group, phenyl group, 4-alkoxyphenyl group, 4-acyloxyphenyl group, etc. are mentioned.
[0080]
R^{twenty one}~ R^{twenty three}As the alkyl group, methyl group, ethyl group, butyl group, octyl group, dodecyl group, isopropyl group, t-butyl group, t-amyl group, t-octyl group, cyclohexyl group, 1-methylcyclohexyl group, benzyl group , A phenethyl group, a 2-phenoxypropyl group, and the like.
[0081]
R^{twenty one}~ R^{twenty three}Examples of the aryl group include phenyl group, cresyl group, xylyl group, naphthyl group, 4-t-butylphenyl group, 4-t-octylphenyl group, 4-anisidyl group, 3,5-dichlorophenyl group, and the like. Group, 4-t-butylphenyl group is preferable, and 4-t-butylphenyl group is particularly preferable.
[0082]
R^{twenty one}~ R^{twenty three}As the alkoxy group, methoxy group, ethoxy group, butoxy group, octyloxy group, 2-ethylhexyloxy group, 3,5,5-trimethylhexyloxy group, dodecyloxy group, cyclohexyloxy group, 4-methylcyclohexyloxy group And benzyloxy group.
[0083]
R^{twenty one}~ R^{twenty three}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.
[0084]
R^{twenty one}~ R^{twenty three}Examples of the amino group include dimethylamino group, diethylamino group, dibutylamino group, dioctylamino group, N-methyl-N-hexylamino group, dicyclohexylamino group, diphenylamino group, N-methyl-N-phenylamino group and the like. Can be mentioned.
[0085]
R^{twenty one}~ R^{twenty three}Are preferably an alkyl group, an aryl group, an alkoxy group, or an aryloxy group. In terms of the effect of the present invention, R^{twenty one}~ R^{twenty three}Of these, at least one is preferably an alkyl group or an aryl group, and more preferably two or more are an alkyl group or an aryl group. In addition, R can be obtained at low cost.^{twenty one}~ R^{twenty three}Are preferably the same group.
[0086]
Specific examples of the hydrogen bonding compound including the compound of the general formula (A) in the present invention are shown below, but the present invention is not limited thereto.
[0087]
Embedded image
[0088]
Embedded image
[0089]
Specific examples of the hydrogen bonding compound include those described in Japanese Patent Application Nos. 2000-192191 and 2000-194411 in addition to the above.
The compound of the general formula (A) of the present invention can be used in a light-sensitive material after being contained 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. The compound of the present invention forms a hydrogen-bonding complex with a compound having a phenolic hydroxyl group or amino group in a solution state, and depending on the combination of the reducing agent and the compound of the general formula (A) of the present invention, It can be isolated in the crystalline 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 (A) of 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 (A) of the present invention is preferably used in the range of 1 to 200 mol%, more preferably in the range of 10 to 150 mol%, more preferably relative to the reducing agent. It is more preferable to use in the range of 30 to 100 mol%.
[0090]
Next, the photosensitive silver halide used in the present invention will be described.
The heat-developable recording material of the present invention contains a photosensitive silver halide. The photosensitive silver halide used in the present invention is not particularly limited as a halogen composition, and silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver iodochlorobromide can be used. Of these, silver bromide and silver iodobromide are preferred. The distribution of the halogen composition in the grains 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, more preferably 2- to 4-fold core / shell particles. A technique of localizing silver bromide on the surface of silver chloride or silver chlorobromide grains can also be preferably used.
[0091]
Methods for forming photosensitive silver halide are well known in the art, for example using the methods described in Research Disclosure No. 17029 of June 1978 and US Pat. No. 3,700,458. Specifically, there is used a method in which a photosensitive silver halide is prepared by adding a silver supply compound and a halogen supply compound to gelatin or another polymer solution, and then mixed with an organic silver salt. In addition, the method described in paragraph Nos. 0217 to 0224 of JP-A No. 11-119374 and the methods described in Japanese Patent Application Nos. 11-98708 and 2000-42336 are also preferable.
[0092]
The grain size of the photosensitive silver halide is preferably small for the purpose of keeping the cloudiness after image formation low, specifically 0.20 μm or less, more preferably 0.01 μm or more and 0.15 μm or less, and still more preferably. It is preferably 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).
[0093]
Examples of the shape of silver halide grains include cubes, octahedrons, tabular grains, spherical grains, rod-shaped grains, and potato-shaped 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 a T.K. based on the adsorption dependency of {111} plane and {100} plane in the adsorption of a sensitizing dye. Tani; Imaging Sci. 29, 165 (1985).
[0094]
In the present invention, silver halide grains in which a hexacyano metal complex is present on the outermost surface of the grains are preferred. As the hexacyano metal complex, [Fe (CN)₆]^Four-, [Fe (CN)₆]^3-, [Ru (CN)₆]^Four-, [Os (CN)₆]^Four-, [Co (CN)₆]^3-, [Rh (CN)₆]^3-, [Ir (CN)₆]^3-, [Cr (CN)₆]^3-, [Re (CN)₆]^3-Etc. In the present invention, a hexacyano Fe complex is preferred.
[0095]
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).
[0096]
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, amides, etc.). Can be added.
[0097]
The amount of hexacyano metal complex added is 1 × 10 5 per mole of silver.^-Five1 x 10 moles or more^-2Or less, more preferably 1 × 10^-Four1 x 10 moles or more^-3It is below the mole.
[0098]
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 aqueous silver nitrate 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.
[0099]
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.
[0100]
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. This silver salt of hexacyanoiron (II) is a less soluble salt than AgI, so that re-dissolution by fine particles can be prevented and silver halide fine particles having a small particle size can be produced. .
[0101]
The photosensitive silver halide grain of the present invention can contain a metal or metal complex of Group 8 to Group 10 of the Periodic Table (showing Groups 1 to 18). As the central metal of the group 8 to group 10 metal or metal complex of the periodic table, rhodium, ruthenium and iridium 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 1 x 10 per mole of silver.^-9From mole to 1 × 10^-3A molar range is preferred. 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. Yes.
[0102]
Further, metal atoms that can be contained in the silver halide grains used in the present invention (for example, [Fe (CN)₆]^Four-), Desalting methods and chemical sensitization methods for silver halide emulsions, paragraph numbers 0046 to 0050 of JP-A-11-84574, paragraph numbers 0025 to 0031 of JP-A-11-65021, and JP-A-11-119374. It is described in paragraph numbers 0242-0250.
[0103]
The photosensitive silver halide grain in the present invention is preferably chemically sensitized by sulfur sensitizing method, selenium sensitizing method or tellurium sensitizing method. As the compound 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), ( Compounds represented by IV) are more preferred.
[0104]
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. In particular, it is preferably performed after spectral sensitization.
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 is 10 per mol of silver halide.^-8-10^-2Moles, preferably 10^-7-10^-3Use moles. 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 to 95 ° C.
A thiosulfonic acid compound may be added to the silver halide emulsion used in the present invention by the method shown in European Patent Publication No. 293,917.
[0105]
The light-sensitive silver halide emulsion in the light-sensitive material used in the present invention may be one kind or two or more kinds (for example, those having different average grain sizes, different halogen compositions, different crystal habits, chemical increase). Those with different feeling conditions) may be used in combination. The gradation can be adjusted by using a plurality of types of photosensitive silver halides having different sensitivities. Techniques relating to these include JP-A-57-119341, 53-106125, 47-3929, 48-55730, 46-5187, 50-73627, 57-150841, and the like. Each publication is listed. The sensitivity difference is preferably 0.2 log E or more for each emulsion.
[0106]
The amount of photosensitive silver halide added is 1m of photosensitive material.²Indicated by the amount of applied silver per unit, 0.03 to 0.6 g / m²Preferably, 0.07 to 0.4 g / m²More preferably, 0.05 to 0.3 g / m²Most preferably, the photosensitive silver halide is 0.01 mol or more and 0.5 mol or less, more preferably 0.02 mol or more and 0.3 mol or less with respect to 1 mol of the organic silver salt.
[0107]
Regarding the mixing method and mixing conditions of the separately prepared photosensitive silver halide and organic silver salt, the silver halide grains and organic silver salt that were prepared respectively were mixed with a high-speed stirrer, ball mill, sand mill, colloid mill, vibration mill, homogenizer. Etc., or a method of preparing an organic silver salt by mixing photosensitive silver halide that has been prepared at any timing during the preparation of the organic silver salt, etc., but the effect of the present invention is sufficient As long as it appears in, there is no particular limitation. Moreover, 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.
[0108]
The preferred addition timing of the silver halide of the present invention to the image forming layer coating solution is from 180 minutes before coating to immediately before, preferably from 60 minutes to 10 seconds before coating. There is no particular limitation as long as the effect is 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 a desired time, and N.I. Harnby, M.M. F. Edwards, A.D. W. There is a method using a static mixer or the like described in Chapter 8 of Nienow's Koji Takahashi's “Liquid Mixing Technology” (published by Nikkan Kogyo Shimbun, 1989).
[0109]
Various gelatins can be used as the gelatin contained in the photosensitive silver halide emulsion used in the present invention. In order to maintain a good dispersion state of the photosensitive silver halide emulsion in the organic silver salt-containing coating solution, it is preferable to use low molecular weight gelatin having a molecular weight of 500 to 60,000. These low molecular weight gelatins may be used at the time of particle formation or dispersion after desalting, but are preferably used at the time of dispersion after desalting.
[0110]
The fact that the photothermographic material of the present invention is infrared sensitized means that the contained photosensitive silver halide is spectrally sensitized in the wavelength region of 750 to 1400 nm by a sensitizing dye. The sensitizing dye to be used may be a known compound. For example, sensitizing dye is spectrally sensitized with various known dyes including cyanine, merocyanine, styryl, hemicyanine, oxonol, hemioxonol and xanthene dye. be able to. Useful cyanine dyes are, for example, cyanine dyes having basic nuclei such as thiazoline nucleus, oxazoline nucleus, pyrroline nucleus, pyridine nucleus, oxazole nucleus, thiazole nucleus, selenazole nucleus, and imidazole nucleus. Useful merocyanine dyes are preferably acidic nuclei such as thiohydantoin nucleus, rhodanine nucleus, oxazolidinedione nucleus, thiazolinedione nucleus, barbituric acid nucleus, thiazolinone nucleus, malononitrile nucleus and pyrazolone nucleus in addition to the basic nuclei described above. Including. Of the above-mentioned cyanine and merocyanine dyes, those having an imino group or a carboxyl group are particularly effective. For example, U.S. Pat. Nos. 3,761,279, 3,719,495, 3,877,943, British Patents 1,466,201, 1,469,117, 1,422,057 No. 3, JP-B-3-10391, JP-A-6-52387, JP-A-5-341432, JP-A-6-194781, JP-A-6-301141 are appropriately used. You may choose.
[0111]
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 the desalting to the start of chemical ripening.
The addition amount of the sensitizing dye in the present invention can be set to a desired amount in accordance with the sensitivity and fogging performance.^-6~ 1 mol is preferred, more preferably 10^-Four-10^-1Is a mole.
[0112]
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 gazette, 10-111543 gazette, etc. are mentioned.
[0113]
The photothermographic material of the invention preferably contains at least one selected from a heteroaromatic mercapto compound or a heteroaromatic disulfide compound.
These compounds are preferably those represented by Ar-SM and Ar-SS-Ar. In the formula, M is a hydrogen atom or an alkali metal atom, and Ar is an aromatic ring or condensed aromatic ring having one or more nitrogen, sulfur, oxygen, selenium or tellurium atoms. Preferably, the heteroaromatic ring is benzimidazole, naphthimidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotelrazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, triazine, pyrimidine, pyridazine , Pyrazine, pyridine, purine, quinoline or quinazolinone.
[0114]
The heteroaromatic ring can be, for example, halogen (eg, Br and Cl), hydroxy, amino, carboxy, alkyl (eg, having one or more carbon atoms, preferably 1 to 4 carbon atoms), alkoxy ( For example, those having one or more carbon atoms, preferably those having 1 to 4 carbon atoms) and those selected from the substituent group consisting of aryl (which may have a substituent) Good.
[0115]
Heteroaromatic mercapto compounds include 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-methylbenzimidazole, 6-ethoxy-2-mercaptobenzothiazole, 2,2 ′. -Dithiobis- (benzothiazole, 3-mercapto-1,2,4-triazole, 4,5-diphenyl-2-imidazolethiol, 2-mercaptoimidazole, 1-ethyl-2-mercaptobenzimidazole, 2-mercaptoquinoline, 8-mercaptopurine, 2-mercapto-4 (3H) -quinazolinone, 7-trifluoromethyl-4-quinolinethiol, 2,3,5,6-tetrachloro-4-pyridinethiol, 4-amino-6-hydroxy -2-Mercaptopirimi Monohydrate, 2-amino-5-mercapto-1,3,4-thiadiazole, 3-amino-5-mercapto-1,2,4-triazole, 4-hydroxy-2-mercaptopyrimidine, 2-mercaptopyrimidine, 4, 6-diamino-2-mercaptopyrimidine, 2-mercapto-4-methylpyrimidine hydrochloride, 3-mercapto-5-phenyl-1,2,4-triazole, 1-phenyl-5-mercaptotetrazole, 3- (5- Mercaptotetrazole) -sodium benzenesulfonate, N-methyl-N ′-{3- (5-mercaptotetrazolyl) phenyl} urea, 2-mercapto-4-phenyloxazole, and the like. It is not limited.
[0116]
The addition amount of these mercapto compounds is preferably in the range of 0.001 to 1 mol per mol of silver in the emulsion layer, and more preferably 0.003 to 0.1 mol per mol of silver. Here, 1 mol of silver means 1 mol of silver halide.
[0117]
The binder used in the present invention will be described.
The binder of the organic silver salt-containing layer of the present invention may be any polymer, suitable binders are transparent or translucent and generally colorless, natural resins, polymers and copolymers, synthetic resins, polymers and copolymers, other films Forming media such as gelatins, rubbers, 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 (eg, poly (vinyl acetal) Marl) 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 coated from water or an organic solvent or emulsion.
[0118]
In the present invention, the glass transition temperature of the binder of the layer containing the organic silver salt is preferably 10 ° C. or higher and 80 ° C. or lower (hereinafter sometimes referred to as a high Tg binder), and more preferably 20 ° C. to 70 ° C. Preferably, it is 23 degreeC or more and 65 degrees C or less.
[0119]
In this specification, Tg was 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 (Tgi) of each monomer was the value of Polymer Handbook (3rd Edition) (by J. Brandrup, EH Immergut (Wiley-Interscience, 1989)).
[0120]
The polymer used as the binder may be used alone or 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 types of polymers having different Tg are blended, the mass average Tg is preferably within the above range.
[0121]
In the present invention, when the organic silver salt-containing 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 organic silver salt-containing layer is further added to an aqueous solvent ( When it is soluble or dispersible in an aqueous solvent), the performance is improved particularly when it is made of a latex of a polymer having an equilibrium water content of 2% by 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 performing purification treatment using a separation functional membrane after polymer synthesis.
[0122]
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.
[0123]
In the case of a system in which the polymer is not dissolved thermodynamically and exists in a so-called dispersed state, the term aqueous solvent is used here.
[0124]
In addition, “equilibrium moisture content at 25 ° C. and 60% RH” refers to the mass W1 of the polymer in a humidity-controlled equilibrium under an atmosphere of 25 ° C. and 60% RH and the mass W0 of the polymer in an absolutely dry state at 25 ° C. Can be expressed as follows.
Equilibrium moisture content at 25 ° C. and 60% RH = {(W1−W0) / W0} × 100 (mass%)
[0125]
For the definition and measurement method of moisture content, for example, Polymer Engineering Course 14, Polymer Material Testing Method (Edited by Society of Polymer Sciences, Jinshokan) can be referred to.
[0126]
The equilibrium moisture content at 25 ° C. and 60% RH of the binder polymer of 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. % To 1% by mass is desirable.
[0127]
In the present invention, a polymer dispersible in an aqueous solvent is particularly preferred. Examples of the dispersed state include latex in which fine particles of a water-insoluble hydrophobic polymer are dispersed and polymer molecules dispersed in a molecular state or forming micelles, and all are preferable. The average particle size of the dispersed particles is preferably 1 to 50000 nm, more preferably about 5 to 1000 nm. 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.
[0128]
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. These polymers have a number average molecular weight of 5,000 to 1,000,000, preferably 10,000 to 200,000. When the molecular weight is too small, the mechanical strength of the emulsion layer is insufficient, and when the molecular weight is too large, the film formability is poor, which is not preferable.
[0129]
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.
[0130]
Latex (molecular weight 37000) of P-1; -MMA (70) -EA (27) -MAA (3)-
Latex of P-2; -MMA (70) -2EHA (20) -St (5) -AA (5)-(molecular weight 40000)
Latex of P-3; -St (50) -Bu (47) -MAA (3)-(crosslinkability)
Latex of P-4; -St (68) -Bu (29) -AA (3)-(crosslinkability)
Latex of P-5; -St (71) -Bu (26) -AA (3)-(crosslinkability, Tg 24 ° C.)
Latex of P-6; -St (70) -Bu (27) -IA (3)-(crosslinkability)
Latex of P-7; -St (75) -Bu (24) -AA (1)-(crosslinkability)
P-8; Latex (crosslinkable) of -St (60) -Bu (35) -DVB (3) -MAA (2)-
Latex (crosslinkability) of P-9; -St (70) -Bu (25) -DVB (2) -AA (3)-
P-10; Latex (molecular weight 80000) of -VC (50) -MMA (20) -EA (20) -AN (5) -AA (5)-
P-11; latex of VDC (85) -MMA (5) -EA (5) -MAA (5)-(molecular weight 67000)
Latex of P-12; -Et (90) -MAA (10)-(molecular weight 12000)
P-13; -St (70) -2EHA (27) -AA (3) latex (molecular weight 130000)
P-14; latex of MMA (63) -EA (35) -AA (2) (molecular weight 33000)
Latex of P-15; -St (70.5) -Bu (26.5) -AA (3)-(crosslinkability, Tg 23 ° C.)
Latex of P-16; -St (69.5) -Bu (27.5) -AA (3)-(crosslinkability, Tg 20.5 ° C)
[0131]
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.
[0132]
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.), poly ( Examples of esters) include: FINETEX ES650, 611, 675, 850 (above made by Dainippon Ink Chemical Co., Ltd.), WD-size, WMS (more made by Eastman Chemical), etc. Examples of rubbers such as HYDRAN AP10, 20, 30, 40 (above made by Dainippon Ink Chemical Co., Ltd.) include LACSTAR 7310K, 3307B, 4700H, 7132C (made by Dainippon Ink Chemical Co., Ltd.) , Nipol Lx416, 410, 438C, 2507 (manufactured by Nippon Zeon Co., Ltd.), etc. Examples of (vinyl chloride) s include G351 and G576 (manufactured by ZEON CORPORATION), and examples of poly (vinylidene chloride) include L502, L513 (manufactured by Asahi Kasei Kogyo Co., Ltd.), and the like. Examples of (olefins) include Chemipearl S120, SA100 (manufactured by Mitsui Petrochemical Co., Ltd.) and the like.
[0133]
These polymer latexes may be used alone or in combination of two or more as required.
[0134]
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 to 99% by mass. The preferred molecular weight range is the same as described above.
[0135]
Examples of the latex of styrene-butadiene copolymer that is preferably used in the present invention include the aforementioned P-3 to P-8, 14, and 15, commercially available LACSTAR-3307B and 7132C, and Nipol Lx416.
[0136]
If necessary, a hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose, carboxymethylcellulose may be added to the organic silver salt-containing 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 organic silver salt-containing layer.
[0137]
The organic silver salt-containing layer (that is, the image forming layer) of the present invention is preferably formed using a polymer latex. The amount of the binder in the organic silver salt-containing layer is preferably such that the mass ratio of all binders / organic silver salt is 1/10 to 10/1, more preferably 1/5 to 4/1.
[0138]
In addition, such an organic silver salt-containing layer is usually a photosensitive layer (emulsion layer) containing a photosensitive silver halide which is a photosensitive silver salt. The mass ratio of silver is preferably 400-5, more preferably 200-10.
[0139]
The total binder amount of the image forming layer of the present invention is 0.2 to 30 g / m.², More preferably 1 to 15 g / m²The range of is preferable. The image forming layer of the present invention may contain a crosslinking agent for crosslinking, a surfactant for improving coating properties, and the like.
[0140]
Other components that can be used in the photothermographic material of the invention will be described.
In the present invention, the solvent of the organic silver salt-containing layer coating solution of the photosensitive material (here, for simplicity, the solvent and the dispersion medium are collectively referred to as a solvent) may be an aqueous solvent containing 30% by mass or more of water. As components other than water, any water-miscible organic solvent such as methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, 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%).
[0141]
Antifoggant, stabilizer and stabilizer precursor that can be used in the present invention, paragraph No. 0070 of JP-A-10-62899, page 20 line 57 to page 21 line 7 of European Patent Publication No. 0803764A1 And the compounds described in JP-A-9-281737 and 9-329864. Further, the antifoggant preferably used in the present invention is an organic halide, and examples thereof include those disclosed in Japanese Patent Application Laid-Open No. 11-65021, paragraphs 0111 to 0112. In particular, an organic halogen compound represented by formula (P) in Japanese Patent Application No. 11-87297, an organic polyhalogen compound represented by general formula (II) in Japanese Patent Application Laid-Open No. 10-339934, and Japanese Patent Application No. 11-205330. The organic polyhalogen compounds described in 1) are preferred.
[0142]
Hereinafter, the organic polyhalogen compound preferable in the present invention will be specifically described. A preferred polyhalogen compound of the present invention is a compound represented by the following general formula (P).
General formula (P)
Q- (Y) n-C (Z₁) (Z₂) X
In the general formula (P), Q represents an alkyl group, an aryl group or a heterocyclic group, Y represents a divalent linking group, n represents 0 or 1, Z₁And Z₂Represents a halogen atom, and X represents a hydrogen atom or an electron-withdrawing group.
[0143]
In the general formula (P), Q preferably represents a phenyl group substituted with an electron-withdrawing 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 electron-withdrawing groups include halogen atoms (fluorine atoms (σp value: 0.06), chlorine atoms (σp value: 0.23), bromine atoms (σp value: 0.23), iodine atoms ( σp value: 0.18)), trihalomethyl group (tribromomethyl (σp value: 0.29), trichloromethyl (σp value: 0.33), trifluoromethyl (σp value: 0.54)), cyano Group (σp value: 0.66), nitro group (σp value: 0.78), aliphatic / aryl or heterocyclic sulfonyl group (for example, methanesulfonyl (σp value: 0.72)), aliphatic / aryl or Heterocyclic acyl groups (for example, acetyl (σp value: 0.50), benzoyl (σp value: 0.43)), alkynyl groups (for example, C≡CH (σp value: 0.23)), aliphatic / aryl Or heterocyclic oxycarbo Group (for example, methoxycarbonyl (σp value: 0.45), phenoxycarbonyl (σp value: 0.44)), carbamoyl group (σp value: 0.36), sulfamoyl group (σp value: 0.57), Examples thereof include a sulfoxide group, a heterocyclic group, and a phosphoryl group. The σp value is preferably in the range of 0.2 to 2.0, more preferably in the range of 0.4 to 1.0. Particularly preferred as an electron-withdrawing group is a carbamoyl group, an alkoxycarbonyl group, an alkylsulfonyl group, or an alkylphosphoryl group, with a carbamoyl group being most preferred.
[0144]
X is preferably an electron-withdrawing group, more preferably a halogen atom, aliphatic / aryl or heterocyclic sulfonyl group, aliphatic / aryl or heterocyclic acyl group, aliphatic / aryl or heterocyclic oxycarbonyl group, carbamoyl A sulfamoyl group, particularly preferably a halogen atom. Among the halogen atoms, a chlorine atom, a bromine atom and an iodine atom are preferable, a chlorine atom and a bromine atom are more preferable, and a bromine atom is particularly preferable.
Y is preferably -C (= O)-, -SO- or -SO.₂  -, More preferably -C (= O)-, -SO₂  -, Particularly preferably -SO₂  -. n represents 0 or 1, and is preferably 1.
[0145]
Specific examples of the compound represented by formula (P) according to the present invention are shown below.
[0146]
Embedded image
[0147]
Embedded image
[0148]
The compound represented by the general formula (P) of the present invention is 10 per mol of the non-photosensitive silver salt of the image forming layer.^-FourIt is preferably used in the range of ˜1 mol, more preferably 10^-3In the range of ~ 0.8 mol, more preferably 5 × 10^-3It is preferable to use in the range of ˜0.5 mol.
In the present invention, examples of the method for adding the antifoggant to the photosensitive material include the methods described in the method for containing a reducing agent.
[0149]
As other antifoggants, mercury (II) salt of paragraph No. 0113 of JP-A No. 11-65021, benzoic acid of paragraph No. 0114 of the same publication, salicylic acid derivative of JP-A No. 2000-206642, JP-A No. 2000-221634 Formalin scavenger compound represented by the formula (S) in JP-A No. 11-352624, a triazine compound according to claim 9 of JP-A-11-352624, a compound represented by formula (III) in JP-A-6-11791, 4 -Hydroxy-6-methyl-1,3,3a, 7-tetrazaindene and the like.
[0150]
The photothermographic material in the invention may contain an azolium salt for the purpose of fog prevention. As the azolium salt, a compound represented by the general formula (XI) described in JP-A-59-193447, a compound described in JP-B-55-12581, a general formula described in JP-A-60-153039 ( And a compound represented by II). The azolium salt may be added to any part of the photosensitive material, but the addition layer is preferably added to the layer having the photosensitive layer, and more preferably to the organic silver salt-containing layer. The azolium salt may be added at any step in the coating solution preparation. When added to the organic silver salt-containing layer, any step from the preparation of the organic silver salt to the preparation of the coating solution may be used. To immediately before coating. The azolium salt may be added by any method such as a powder, a solution, or a 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, any amount of the azolium salt may be added, but 1 × 10 10 per silver mole.^-6Preferred is 1 mol or more and 2 mol or less.^-3More preferably, it is more than mol and less than 0.5 mol.
[0151]
In the photothermographic material of the present invention, it is preferable to add a color toning agent. For the color toning agent, paragraph numbers 0054 to 0055 of JP-A No. 10-62899, page 21, lines 23 to 48 of European Patent Publication No. 0803764A1, JP-A-2000-356317 and Japanese Patent Application No. 2000-187298, 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 Phthalazines (phthalazine, phthalazine derivatives or metal salts; for example, 4- (1-naphthyl) phthalazine, 6-isopropylphthalazine, 6-t-butylphthalazine, 6-chlorophthalazine, 5,7-dimethoxy Phthalazine and 2,3-dihydrophthalazine); a combination of phthalazines and phthalic acids is preferred, and a combination of phthalazines and phthalic acids is particularly preferred.
[0152]
Regarding the plasticizer and lubricant that can be used in the photosensitive layer of the present invention, paragraph No. 0117 of JP-A No. 11-65021, the super-high contrast agent for forming a super-high contrast image, and the addition method and amount thereof are the same. Paragraph No. 0118, Japanese Patent Laid-Open No. 11-223898, Paragraph Nos. 0136 to 0193, Japanese Patent Application No. 11-87297, formulas (H), formulas (1) to (3), formulas (A) and (B) Regarding compounds, compounds of general formulas (III) to (V) described in Japanese Patent Application No. 11-91652 (specific compounds: Chemical Formula 21 to Chemical Formula 24), and contrast accelerators, paragraph No. 0102 of JP-A No. 11-65021 JP-A-11-223898, paragraph numbers 0194 to 0195.
[0153]
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.
[0154]
When the ultrahigh contrast 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, ammonium hexametaphosphate and the like.
Amount of acid or salt thereof formed by hydration of diphosphorus pentoxide (1m photosensitive material)²The coating amount per unit) may be a desired amount according to the performance such as sensitivity and fog, but is 0.1 to 500 mg / m.²Is preferably 0.5 to 100 mg / m²Is more preferable.
[0155]
The photothermographic material of the present invention can be provided with a surface protective layer for the purpose of preventing adhesion of the image forming layer. The surface protective layer may be a single layer or a plurality of layers. The surface protective layer is described in JP-A No. 11-65021, paragraph numbers 0119 to 0120 and Japanese Patent Application No. 2000-171936.
As the binder for the surface protective layer of the present invention, gelatin is preferable, but it is also preferable to use polyvinyl alcohol (PVA) or a combination thereof. As gelatin, inert gelatin (for example, Nitta gelatin 750), phthalated gelatin (for example, Nitta gelatin 801), or the like can be used. Examples of PVA include those described in paragraph Nos. 0009 to 0020 of JP-A No. 2000-171936. Completely saponified PVA-105, partially saponified PVA-205, PVA-335, and modified polyvinyl alcohol MP- 203 (trade name, manufactured by Kuraray Co., Ltd.) and the like are preferable. Polyvinyl alcohol coating amount of protective layer (per layer) (support 1m²Per unit) as 0.3 to 4.0 g / m²Is preferable, 0.3 to 2.0 g / m²Is more preferable.
[0156]
In particular, when the photothermographic material of the present invention is used for printing applications in which dimensional change is a problem, it is preferable to use a polymer latex for the surface protective layer or the back layer. For such polymer latex, “Synthetic resin emulsion (Hiraku Okuda, Hiroshi Inagaki, published by Kobunshi Publishing Co., Ltd. (1978))”, “Application of synthetic latex (Takaaki Sugimura, Ikuo Kataoka, Junichi Suzuki, Keiji Kasahara, Takashi Kasahara) "Molecular Publication (1993))", "Synthetic Latex Chemistry (Muroichi Muroi, published by High Polymer Publication (1970))", etc., specifically methyl methacrylate (33.5% by mass) / Ethyl acrylate (50 wt%) / methacrylic acid (16.5 wt%) copolymer latex, methyl methacrylate (47.5 wt%) / butadiene (47.5 wt%) / itaconic acid (5 wt%) copolymer Latex, latex of copolymer of ethyl acrylate / methacrylic acid, methyl methacrylate (58.9% by mass) / 2-ethyl Silicate (25.4% by weight) / styrene (8.6% by weight) / 2-hydroxyethyl methacrylate (5.1% by weight) / acrylic acid (2.0% by weight) copolymer latex, methyl methacrylate (64. 0 mass%) / styrene (9.0 mass%) / butyl acrylate (20.0 mass%) / 2-hydroxyethyl methacrylate (5.0 mass%) / acrylic acid (2.0 mass%) copolymer latex, etc. Is mentioned. Further, as a binder for the surface protective layer, a combination of polymer latex described in Japanese Patent Application No. 11-6872, the technique described in Paragraph Nos. 0021 to 0025 of Japanese Patent Application No. 11-143058, Japanese Patent Application No. 11- The technique described in paragraph Nos. 0027 to 0028 of No. 6872 and the technique described in paragraph Nos. 0023 to 0041 of Japanese Patent Application No. 10-199626 may be applied. The ratio of the polymer latex in the surface protective layer is preferably 10% by mass or more and 90% by mass or less, and particularly preferably 20% by mass or more and 80% by mass or less of the total binder.
Total binder (including water-soluble polymer and latex polymer) coating amount of surface protective layer (per layer) (support 1m)²As per) 0.3 to 5.0 g / m²Is preferable, 0.3 to 2.0 g / m²Is more preferable.
[0157]
The preparation temperature of the image forming layer coating solution of the present 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.
[0158]
The image forming layer of the present invention is composed of one or more layers on a support. When it is composed of one layer, it consists of an organic silver salt, a photosensitive silver halide, a reducing agent and a binder, and optionally contains additional materials such as a colorant, a coating aid and other auxiliary agents. In the case of two or more layers, an organic silver salt and a light-sensitive silver halide are contained in the first image forming layer (usually a layer adjacent to the support), and some in the second image forming layer or both layers. Must contain other ingredients. The construction of a multicolor photosensitive photothermographic material may include a combination of these two layers for each color and all components in a single layer as described in US Pat. No. 4,708,928. May be included. In the case of multi-dye multicolor photosensitive photothermographic materials, each emulsion layer is generally functional or non-functional between each photosensitive layer as described in US Pat. No. 4,460,681. By using different barrier layers, they are distinguished from each other and held.
[0159]
In the photosensitive layer of the present invention, various dyes and pigments (for example, CI Pigment Blue 60, CI Pigment Blue 64, C.I. Pigment Blue 64, C.I. I. 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.
[0160]
In the photothermographic material of the present invention, the antihalation layer can be provided on the side far from the light source with respect to the photosensitive layer.
[0161]
The photothermographic material generally has a non-photosensitive layer in addition to the photosensitive layer. The non-photosensitive layer includes (1) a protective layer provided on the photosensitive layer (on the side farther from the support), and (2) a plurality of photosensitive layers or between the photosensitive layer and the protective layer. (3) an undercoat layer provided between the photosensitive layer and the support, and (4) a back layer provided on the opposite side of the photosensitive layer. The filter layer is provided on the photosensitive material as the layer (1) or (2). The antihalation layer is provided on the photosensitive material as the layer (3) or (4).
[0162]
As for the antihalation layer, paragraph numbers 0123 to 0124 of JP-A No. 11-65021, JP-A Nos. 11-223898, 9-230531, 10-36695, 10-104779, 11- 231457, 11-352625, 11-352626 and the like.
The antihalation layer contains an antihalation dye having absorption at the exposure wavelength. When the exposure wavelength is in the infrared region, an infrared absorbing dye may be used, and in that case, a dye having no absorption in the visible region is preferable.
When antihalation is performed using a dye having absorption in the visible range, it is preferable that substantially no dye color remains after image formation, and a means for decoloring by the heat of heat development is used. In particular, it is preferable to add a thermally decolorable dye and a base precursor to the non-photosensitive layer to function as an antihalation layer. These techniques are described in JP-A-11-231457.
[0163]
The amount of decoloring dye added is determined by the use of the dye. In general, the optical density (absorbance) measured at the target wavelength is used in an amount exceeding 0.1. The optical density is preferably 0.2-2. The amount of dye used to obtain such an optical density is generally 0.001 to 1 g / m.²Degree.
[0164]
When the dye is decolored in this way, the optical density after heat development can be reduced to 0.1 or less. Two or more kinds of decoloring dyes may be used in combination in a heat decoloring type recording material or a photothermographic material. Similarly, two or more kinds of base precursors may be used in combination.
In the thermal decolorization using such decoloring dye and base precursor, a substance (for example, diphenylsulfone, which lowers the melting point by 3 ° C. (deg) or more when mixed with a base precursor as described in JP-A No. 11-352626). 4-Chlorophenyl (phenyl) sulfone) is preferably used in view of thermal decoloring properties and the like.
[0165]
In the present invention, a colorant having an absorption maximum at 300 to 450 nm can be added for the purpose of improving the silver color tone and the temporal change of the image. Such colorants are disclosed in JP-A-62-210458, JP-A-63-104046, JP-A-63-103235, JP-A-63-208846, JP-A-63-306436, and JP-A-63-1314535. Japanese Patent Application Laid-Open No. 01-61745, Japanese Patent Application No. 11-276751, and the like.
Such colorants are typically 0.1 mg / m²~ 1g / m²The back layer provided on the opposite side of the photosensitive layer is preferable as the layer to be added in the range of.
[0166]
The photothermographic material in the invention is a so-called single-sided photosensitive material having a photosensitive layer containing at least one silver halide emulsion on one side of a support and a back layer on the other side. preferable.
[0167]
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. Matting agent is photosensitive material 1m²When expressed in a coating amount per unit, preferably 1 to 400 mg / m², More preferably 5 to 300 mg / m²It is.
The emulsion surface may have any matte degree as long as no stardust failure occurs, but the Beck smoothness is preferably 30 seconds or more and 2000 seconds or less, and particularly preferably 40 seconds or more and 1500 seconds or less. The Beck smoothness can be easily obtained by Japanese Industrial Standard (JIS) P8119 “Smoothness test method using Beck tester for paper and paperboard” and TAPPI standard method T479.
[0168]
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.
[0169]
In the present invention, the matting agent is preferably contained in the outermost surface layer of the photosensitive material, the layer functioning as the outermost surface layer, or a layer close to the outer surface, and is contained in a layer acting as a so-called protective layer. It is preferable.
[0170]
The back layer applicable to the present invention is described in paragraph numbers 0128 to 0130 of JP-A No. 11-65021.
[0171]
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 membrane surface pH is preferably adjusted from the viewpoint of reducing the membrane surface pH by 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. 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. The method for measuring the film surface pH is described in paragraph No. 0123 of Japanese Patent Application No. 11-87297.
[0172]
A hardener may be used for each layer such as the photosensitive layer, protective layer, and back layer of the present invention. Examples of hardeners include T.W. H. There are various methods described in "THE THEORY OF THE PHOTOGRAPHIC PROCESS FOURTH EDITION" by James (published by Macmillan Publishing Co., Inc., published in 1977), pages 77 to 87. Chrome Alum, 2,4-Dichloro 6-hydroxy -S-triazine sodium salt, N, N-ethylenebis (vinylsulfonacetamide), N, N-propylenebis (vinylsulfonacetamide), polyvalent metal ions described on page 78 of the same, U.S. Pat. No. 4,281, Polyisocyanates such as 060, JP-A-6-208193, epoxy compounds such as US Pat. No. 4,791,042, and vinyl sulfone compounds such as JP-A-62-89048 are preferably used. It is.
[0173]
The hardening agent is added as a solution, and the addition time of this solution into the protective layer coating solution is from 180 minutes before to immediately before application, preferably from 60 minutes to 10 seconds before application. As long as the effects of the present invention are sufficiently exhibited, there is no particular limitation. 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 a desired time, and N.I. Harnby, M.M. F. Edwards, A.D. W. There is a method using a static mixer or the like described in Chapter 8 of Nienow's Koji Takahashi's “Liquid Mixing Technology” (published by Nikkan Kogyo Shimbun, 1989).
[0174]
Regarding the surfactant applicable to the present invention, paragraph No. 0132 of JP-A No. 11-65021, paragraph No. 0133 of the solvent, paragraph No. 0134 of the support, and paragraph of the antistatic or conductive layer are the same paragraph. No. 0135, a method for obtaining a color image is described in paragraph No. 0136 of the same publication, and a slip agent is described in JP-A No. 11-84573, paragraph Nos. 0061 to 0064 and Japanese Patent Application No. 11-106881, paragraph Nos. 0049 to 0062. .
[0175]
The transparent support is a polyester, particularly polyethylene, which has been heat-treated in a temperature range of 130 to 185 ° C. in order to relieve internal strain remaining in the film during biaxial stretching and to eliminate thermal shrinkage strain generated during heat development. 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. The support includes a water-soluble polyester of JP-A-11-84574, a styrene-butadiene copolymer of JP-A-10-186565, paragraphs 0063 to 0080 of JP-A No. 2000-39684 and Japanese Patent Application No. 11-106881. It is preferable to apply an undercoating technique such as a vinylidene chloride copolymer. In addition, regarding the antistatic layer or the undercoat, paragraph numbers 0040 to of JP-A-56-143430, JP-A-56-143431, JP-A-58-62646, JP-A-56-120519, JP-A-11-84573. The techniques described in paragraph Nos. 0078 to 0084 of 0051, US Pat. No. 5,575,957 and JP-A-11-223898 can be applied.
[0176]
The photothermographic material is preferably a mono-sheet type (a type capable of forming an image on the photothermographic material without using another sheet such as an image receiving material).
[0177]
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 photosensitive layer or the non-photosensitive layer. Regarding these, reference can be made to WO 98/36322, EP 803764A1, JP-A-10-186567, 10-18568, and the like.
[0178]
The photothermographic material in the invention may be applied by any method. Specifically, various coating operations including extrusion coating, slide coating, curtain coating, dip coating, knife coating, flow coating, or extrusion coating using a hopper of the type described in US Pat. No. 2,681,294. And Stephen F. Kistler, Peter M. et al. Extrusion coating or slide coating described in pages 399 to 536 of “LIQUID FILM COATING” (CHAPMAN & HALL, 1997) by Schweizer is preferably used, and slide coating is particularly preferably used. An example of the shape of a slide coater used for slide coating is shown in FIG. 11b. 1 If desired, two or more layers can be simultaneously coated by the method described on pages 399 to 536 of the same document, the method described in US Pat. No. 2,761,791 and British Patent No. 837,095. .
[0179]
The organic silver salt-containing layer coating solution in the present invention is preferably a so-called thixotropic fluid. Regarding this technique, JP-A-11-52509 can be referred to. The organic silver salt-containing layer coating solution in the present invention has a shear rate of 0.1 S.^-1The viscosity in is preferably 400 mPa · s or more and 100,000 mPa · s or less, and more preferably 500 mPa · s or more and 20,000 mPa · s or less. Also, shear rate 1000S^-1Is preferably from 1 mPa · s to 200 mPa · s, more preferably from 5 mPa · s to 80 mPa · s.
[0180]
Techniques that can be used for the photothermographic material of the present invention include EP80364A1, EP883022A1, WO98 / 36322, JP56-62648, 58-62644, and JP9-43766. No. 9-281737, No. 9-297367, No. 9-304869, No. 9-31405, No. 9-329865, No. 10-10669, No. 10-62899, JP-A-10-69023, JP-A-10-186568, JP-A-10-90823, JP-A-10-171063, JP-A-10-186565, JP-A-10-186567, and JP-A-10-186669 No. 10-186572, No. 10-197974, No. 10-197982 10-197983, 10-197985 to 10-197987, 10-207001, 10-207004, 10-221807, 10-282601, 10-288823, 10-288824, 10-307365, 10-312038, 10-339934, 11-7100, 11-15105, 11-24200, 11-24201, 11-30832, 11-84574, 11-65021, 11-109547, 11-125880, 11 -129629, 11-133536-11-133539, 11 No. 133542, No. 11-133543, No. 11-223898, No. 11-352627, No. 11-305377, No. 11-305378, No. 11-305384, No. 11-305380 Publication No. 11-316435 Publication No. 11-327076 Publication No. 11-338096 Publication No. 11-338098 Publication No. 11-338099 Publication No. 11-343420 Publication No. 11-343420 Publication No. 2000-187298 , 2000-10229, 2000-47345, 2000-206642, 2000-98530, 2000-98531, 2000-112059, 2000-112060, 2000-112104, 2000-121204, 200 No. 0-171936 is also mentioned.
[0181]
The photothermographic material of the present invention may be heat-developed by any method. Usually, the photothermographic material exposed imagewise is heat-developed. A preferable heat development processing temperature is 80 to 250 ° C, and more preferably 100 to 140 ° C. The heat development time is preferably 1 to 60 seconds, more preferably 3 to 30 seconds, and particularly preferably 5 to 20 seconds. Most preferably, it is 10 to 15 seconds. When the heat development processing time is 1 to 60 seconds, the sensitivity is higher than that in the case where a conventional photothermographic material is subjected to heat development processing.
[0182]
A plate heater method is preferred as the heat development method. The plate heater type heat development method is preferably a method described in JP-A No. 11-133572, and a visible image is obtained by bringing a photothermographic material having a latent image formed thereon into contact with a heating means in a heat development part. 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 heat development apparatus characterized in that heat development is performed by passing a photothermographic material. It is preferable to divide the plate heater into 2 to 6 stages and lower the temperature about 1 to 10 ° C. at the tip. 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 can be rapidly exposed to photothermographic material. A change in the shape of the support of the photothermographic material due to the heating of the material can also be suppressed.
[0183]
The light-sensitive material of the present invention may be exposed by any method, but laser light is preferred as the exposure light source. As the laser beam according to the present invention, a gas laser, a YAG laser, a dye laser, a semiconductor laser and the like are preferable. Also, a semiconductor laser and a second harmonic generation element can be used. Particularly preferred is an infrared-emitting semiconductor laser.
[0184]
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.
[0185]
【Example】
EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.
[0186]
Example 1
<< Preparation of PET support >>
PET having an intrinsic viscosity of IV = 0.66 (measured in phenol / tetrachloroethane = 6/4 (weight ratio) at 25 ° C.) was obtained using terephthalic acid and ethylene glycol according to a conventional method. This was pelletized, dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die, and rapidly cooled to produce an unstretched film having a thickness of 175 μm after heat setting.
[0187]
This was longitudinally stretched 3.3 times using rolls having different peripheral speeds and then stretched 4.5 times with a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively. Then, after heat setting at 240 ° C. for 20 seconds, the film was relaxed by 4% in the lateral direction at the same temperature. After this, after slitting the chuck part of the tenter, knurling is performed on both ends and 4 kg / cm.²(4x10^FourPa) to obtain a roll having a thickness of 175 μm.
[0188]
Using a solid state corona treatment machine 6KVA model manufactured by Pillar, both surfaces of the support were treated at room temperature at 20 m / min. From the current and voltage readings at this time, the support is 0.375 kV · A · min / m.²It was found that the process was done. 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.
[0189]
<< Preparation of silver halide emulsion >>
Dissolve 22 g of phthalated gelatin and 30 mg of potassium bromide in 700 ml of distilled water, adjust the pH to 5.0 at a temperature of 35 ° C., and then add bromide to 159 ml of an aqueous solution containing 18.6 g of silver nitrate and 0.9 g of ammonium nitrate. An aqueous solution containing potassium and potassium iodide at a molar ratio of 92: 8 was added over 10 minutes by the control double jet method while maintaining pAg 7.7. Subsequently, 476 ml of an aqueous solution containing 55.4 g of silver nitrate and 2 g of ammonium nitrate and an aqueous solution pAg of 7.7 ml of dipotassium hexachloroiridate and 1 mol / liter of potassium bromide were maintained for 30 minutes by the control double jet method. After the addition, 1 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added, and the pH was lowered to cause aggregation and sedimentation, followed by desalting.
Thereafter, 0.1 g of phenoxyethanol was added to adjust to pH 5.9 and pAg 8.2 to prepare silver iodobromide grains (iodine content core 8 mol%, average 2 mol%, average size 0.05 μm, projected area variation coefficient 8%, (100 ) Preparation of (cubic particles having an area ratio of 88%) was completed.
The silver halide grains thus obtained were heated to 60 ° C. and 85 μmol of sodium thiosulfate and 11 μmol, 15 μmol of tellurium compound A of 2,3,4,5,6-pentafluorophenyldiphenylphosphine selenide per mol of silver, Chloroauric acid (3.4 μmol) and thiocyanic acid (200 μmol) were added, ripened for 120 minutes, and then rapidly cooled to 30 ° C. to obtain a silver halide emulsion.
[0190]
<< Preparation of organic acid silver emulsion >>
7 g of stearic acid, 4 g of arachidic acid, 36 g of behenic acid and 850 ml of distilled water were stirred at 90 ° C. while adding 187 ml of 1N NaOH aqueous solution and reacted for 60 minutes. After adding 65 ml of 1N nitric acid, the temperature was lowered to 50 ° C. . Next, 0.6 g of N-bromosuccinimide was added while stirring more vigorously, and after 10 minutes, silver halide grains prepared in advance were added so that the amount of silver halide was 6.2 mmol. Further, 125 ml of an aqueous solution of 21 g of silver nitrate was added over 100 seconds, and the stirring was continued for 10 minutes. Then, 0.6 g of N-bromosuccinimide was added and left for another 10 minutes. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtrate reached 30 μS / cm. After adding 150 g of a 0.6 mass% butyl acetate solution of polyvinyl acetate to the solid content thus obtained and stirring, the stirring was stopped and the mixture was left to separate into an oil layer and an aqueous layer. Obtained. Next, 80 g of a 2.5 mass% 2-butanone solution of polyvinyl butyral (Denka Butyral # 3000-K manufactured by Denki Kagaku Kogyo Co., Ltd.) was added to the oil layer and stirred. Further, after adding 0.1 mmol of pyridinium perbromide bromide and 0.1 mmol of calcium bromide dihydrate together with 0.7 g of methanol, 200 g of 2-butanone and polyvinyl butyral (BUTVAR manufactured by Monsanto)^TM  59 g of B-76) was added and dispersed with a homogenizer to obtain an organic acid silver salt emulsion (acicular grains having an average minor axis of 0.04 μm, an average major axis of 1 μm, and a variation coefficient of 30%).
[0191]
<Preparation of emulsion layer coating solution>
Each chemical was added to the organic acid silver emulsion obtained above so as to have the following amount per 1 mol of silver. Sodium phenylthiosulfonate 10 mg at 25 ° C., 80 mg of dye A, heteroaromatic mercapto compound (amount and type are listed in Table 5), compound of general formula (II) of the present invention (amount and type are listed in Table 5) ), 12 g of 4-chlorobenzophenone-2-carboxylic acid, 10 g of monobutyl phthalate, 580 g of 2-butanone, and 220 g of dimethylformamide were added with stirring. Subsequently, 3 g of 5-tribromomethylsulfonyl-2-methylthiadiazole, 3 g of tribromomethylnaphthylsulfone, 6 g of tribromomethylphenylsulfone, 5 g of 4,6-ditrichloromethyl-2-phenyltriazine, the general formula (I ) Compound (amount and type are listed in Table 5), 12 g of dye A, Megafax F-176P (fluorine surfactant manufactured by Dainippon Ink & Chemicals, Inc.) 1.1 g, methyl ethyl ketone (MEK) 590 g 10 g of methyl isobutyl ketone (MIBK) was added with stirring to obtain an emulsion layer coating solution.
[0192]
<Emulsion surface protective layer coating solution>
CAB171-15S (Eastman Chemical Co., Ltd. cellulose acetate butyrate) 75 g, 4-methylphthalic acid 5.7 g, tetrachlorophthalic anhydride 1.5 g, phthalazine 12.5 g, tetrachlorophthalic acid 5.1 g, 0.1 g. 3 g of Megafax F-176P, 2 g of Sildex H31 (manufactured by Dokai Chemical Co., Ltd., true spherical silica average size 3 μm) and 7 g of sumidur N3500 (polyisocyanate made by Sumitomo Bayer Urethane Co., Ltd.) were dissolved in 3070 g of MEK and 30 g of ethyl acetate. Things were prepared.
[0193]
《Back surface application》
6 g of polyvinyl butyral (Denka Butyral # 4000-2 manufactured by Denki Kagaku Kogyo Co., Ltd.), 0.2 g of Sildex H121 (True spherical silica average size 12 μm manufactured by Dokai Chemical Co., Ltd.), Sildex H51 (True spherical manufactured by Dokai Chemical Co., Ltd.) 0.2 g of silica (average size of 5 μm) and 0.1 g of Megafax F-176P were added to 64 g of 2-propanol with stirring and dissolved and mixed. Further, a solution of 420 mg of dye A in 10 g of methanol and 20 g of acetone and a solution of 7 g of ethyl acetate in 1 g of 3-isocyanatomethyl-3,5,5-trimethylhexyl isocyanate were prepared.
The back surface coating solution was applied on a polyethylene terephthalate film comprising a moisture-proof undercoat containing vinylidene chloride on both sides so that the optical density of 810 nm was 0.4. Further, the smoothness of the back surface (the Beck smoothness was examined using the Oken type smoothness measurement described in J. TAPPI paper pulp test method No. 5) was 80 seconds.
[0194]
<< Preparation of photosensitive material >>
The emulsion layer and the emulsion surface protective layer were coated on the 175 μm polyethylene terephthalate support having the back surface previously coated as described above, and the emulsion layer coating solution was 2.3 g / m of silver.²The emulsion surface protective layer coating solution was coated on the emulsion surface to a dry thickness of 2 μm. Further, when the residual amount of the solvent on the coated surface of the emulsion layer in the coated sample was measured by gas chromatography, 40 to 200 ppm of MEK, 10 to 100 ppm of MIBK, and 40 to 120 ppm of butyl acetate were detected on the basis of the coating substance amount.
[0195]
The structural formulas of the compounds used in the preparation of the photothermographic material of Example 1 are shown below.
[0196]
Embedded image
[0197]
<Evaluation of photographic performance>
After exposing the photographic material with a laser sensitometer equipped with a 810 nm diode, the photographic material was processed (developed) at 120 ° C. for 24 seconds and 12 seconds, and the obtained image was evaluated with a densitometer. The sensitivity was evaluated by the reciprocal of the ratio of the exposure amount that gives a density 1.0 higher than Dmin. Larger numbers are more sensitive and desirable performance.
[0198]
[Table 5]
[0199]
The results in Table 5 indicate that the examples having the constituent features of the present invention have higher sensitivity than the comparative examples. In particular, this effect is remarkable when the developing time is 12 seconds.
[0200]
(Example 2)
<< Preparation of photosensitive silver halide emulsion >>
To 5429 ml of distilled water, 88.3 g of phenylcarbamoyl gelatin, PAO compound (HO (CH₂CH₂O) n- (CH (CH_Three) CH₂O)₁₇-(CH₂CH₂10) 10% methanol aqueous solution of O) m-H; m + n = 5 to 7) and 0.32 g of potassium bromide were added and dissolved. Furthermore, 659 ml of a 0.67 mol / l silver nitrate aqueous solution and a solution in which 0.703 mol of KBr and 0.013 mol of KI were dissolved per liter were dissolved in Japanese Patent Publication No. 58-58288. Using a mixing stirrer disclosed in Japanese Patent Publication No. 58-58289, nucleation was carried out by adding 2 minutes 45 seconds by the simultaneous mixing method while controlling to pAg 8.09. After 1 minute, 20 ml of a 0.63N potassium hydroxide solution was added. After 6 minutes, 1976 ml of a 0.67 mol / l silver nitrate aqueous solution and a solution in which 0.657 mol of KBr, 0.013 mol of potassium iodide and 30 μmol of dipotassium hexachloroiridate were dissolved at a temperature of 45 ° C. The mixture was added over 14 minutes and 15 seconds by the simultaneous mixing method while controlling at pAg of 8.09. After stirring for 5 minutes, the temperature was lowered to 40 ° C.
[0201]
To this was added 18 ml of a 56% aqueous acetic acid solution to precipitate the silver halide emulsion. The supernatant was removed, leaving 2 liters of sediment, 10 liters of water was added, and after stirring, the silver halide emulsion was sedimented again. Furthermore, 1.5 liters of the sedimented portion was left, the supernatant was removed, 10 liters were further added, and after stirring, the silver halide emulsion was sedimented. After leaving 1.5 liter of sedimented portion and removing the supernatant, a solution of 1.72 g of anhydrous sodium carbonate dissolved in 151 ml of water was added, and the temperature was raised to 60 ° C. The mixture was further stirred for 120 minutes. Finally, the pH was adjusted to 5.0, and water was added to 1161 g per 1 mol of silver.
This emulsion was monodispersed cubic silver iodobromide grains having an average grain size of 0.03 μm, a grain size variation coefficient of 12%, and a [100] face ratio of 92%.
[0202]
<Preparation of powdered organic silver salt>
After dissolving 130.8 g of behenic acid, 67.7 g of arachidic acid, 43.6 g of stearic acid and 2.3 g of palmitic acid in 4720 ml of distilled water at 80 ° C., 540.2 ml of 1.5N sodium hydroxide aqueous solution was added, After adding 6.9 ml of concentrated nitric acid, the mixture was cooled to 55 ° C. to obtain an organic acid sodium solution. While maintaining the temperature of the organic acid sodium solution at 55 ° C., 45.3 g of the silver halide emulsion and 450 ml of pure water were added, and 13200 rpm (mechanical vibration frequency) by a homogenizer (ULTRA-TURRAX-25) manufactured by IKA JAPAN. As 21.1 KHz) for 5 minutes. Next, 702.6 ml of a 1 mol / l silver nitrate solution was added over 2 minutes and stirred for 10 minutes to obtain an organic silver salt dispersion. Thereafter, the obtained organic silver salt dispersion was transferred to a water-washing container, deionized water was added and stirred, and then allowed to stand to float and separate the organic silver salt dispersion, thereby removing the lower water-soluble salts. Thereafter, washing with deionized water and drainage are repeated until the conductivity of the drainage reaches 2 μS / cm, and after centrifugal dehydration, drying is performed with a hot air circulating dryer until there is no mass loss at 40 ° C. A powdered organic silver salt was obtained.
[0203]
<Preparation of photosensitive emulsion dispersion>
Dissolve 14.57 g of polyvinyl butyral powder (Monsant Butvar B-79) in 1457 g of methyl ethyl ketone (MEK), and gradually add 500 g of powdered organic silver salt while stirring with VMA-GETZMANN type dissolver DISPERMAT CA-40M. And mixed well to form a slurry. A photosensitive emulsion dispersion was prepared by dispersing the slurry in two baths with a GM-2 pressure homogenizer manufactured by SMT. At this time, the processing pressure for one bath is 280 kg / cm.²The processing pressure during 2 baths is 560 kg / cm²It was.
[0204]
<Adjustment of photosensitive layer coating solution>
15.1 g of MEK was added to the photosensitive emulsion dispersion (50 g), and the mixture was kept at 21 ° C. while stirring at 1000 rpm with a dissolver type homogenizer, and 2 molecules of N, N-dimethylacetamide / 1 molecule of bromic acid / 1 molecule of bromine. 390 μl of a 10% by mass methanol solution of the aggregate was added and stirred for 1 hour. Further, 494 μl of a 10 mass% methanol solution of calcium bromide was added and stirred for 20 minutes. Subsequently, after adding 167 mg of a methanol solution containing 15.9% by mass of dibenzo-18-crown-6 and 4.9% by mass of potassium acetate and stirring for 10 minutes, 0.24% by mass of dye B, 18 Add 2.6 g of MEK solution of 3% by mass of 2-chlorobenzoic acid, 34.2% by mass of salicylic acid-p-toluenesulfonate and a heteroaromatic mercapto compound (type and amount are listed in Table 6). Stir for hours. Thereafter, the temperature was lowered to 13 ° C., and the mixture was further stirred for 30 minutes. While maintaining the temperature at 13 ° C., 13.31 g of polyvinyl butyral (Monsant Butvar B-79) was added and stirred for 30 minutes, and then 1.08 g of a 9.4 mass% tetrachlorophthalic acid solution was added for 15 minutes. Stir. While continuing to stir, the compound of general formula (I) of the present invention (type and amount are listed in Table 6), the compound of general formula (II) of the present invention (type and amount are listed in Table 6), 1.1 12.4 g of MEK solution of 4% by weight of 4-methylphthalic acid and Dye 1 are added, 1.5 g of 10% by weight of Desmodur N3300 (Mobay Aliphatic Isocyanate) are continuously added, and another 7.4% by weight of Trik. A photosensitive layer coating solution was obtained by adding 4.27 g of MEK solution of bromomethyl-2-azaphenylsulfone and 7.2% by mass of phthalazine.
[0205]
<Adjustment of surface protective layer coating solution>
While stirring MEK865g, 96 g of cellulose acetate butyrate (Eastman Chemical, CAB171-15), 4.5 g of polymethylmethacrylic acid (Rohm & Haas, Paraloid A-21), 1,3-di (vinylsulfonyl)- After adding and dissolving 1.5 g of 2-propanol, 1.0 g of benzotriazole and 1.0 g of a fluorine-based activator (Asahi Glass Co., Surflon KH40), 13.6% by mass of cellulose acetate butyrate (Eastman Chemical Co., CAB171) -15) and 9% by mass of calcium carbonate (Speciality Minerals, Super-Pflex 200) dispersed in MEK for 30 minutes at 8000 rpm with a dissolver type homogenizer, 30 g was added and stirred. The protective layer coating solution was prepared.
[0206]
<Production of support>
Concentration of 0.170 (Konica Densitometer PDA-65) colored blue, 8 W / m on both sides of a 175 μm thick PET film²-Minona corona discharge treatment was applied.
[0207]
<Back side application>
While stirring 830 g of MEK, 84.2 g of cellulose acetate butyrate (Eastman Chemical, CAB381-20) and 4.5 g of a polyester resin (Bostic, VitelPE2200B) were added and dissolved. To this dissolved liquid, 0.30 g of dye B was added, and 4.5 g of a fluorine-based activator (Asahi Glass Co., Surflon KH40) dissolved in 43.2 g of methanol and a fluorine-based activator (Dainippon Ink, Megafag F120K). ) 2.3g was added and stirred well until dissolved. Finally, 75 g of silica (WR Grace, Syloid 64X6000) dispersed in methyl ethyl ketone at a concentration of 1% by mass with a dissolver type homogenizer was added and stirred to prepare a coating solution for the back surface.
The back surface coating solution thus adjusted was applied and dried by an extrusion coater so that the dry film thickness was 3.5 μm. It dried for 5 minutes using the drying air with a drying temperature of 100 degreeC, and the outdoor temperature of 10 degreeC.
[0208]
<< Preparation of photosensitive material >>
The photosensitive layer coating solution and the surface protective layer coating solution were extruded and simultaneously coated on a support on which the back surface was coated with a coater to prepare a photosensitive material. For coating, the photosensitive layer has a coated silver amount of 1.9 g / m.²The surface protective layer was formed so as to have a dry film thickness of 2.5 μm. Then, it dried for 10 minutes using the drying air with a drying temperature of 75 degreeC and a dew point temperature of 10 degreeC.
The sum of MEK and methanol content obtained for the photosensitive material thus obtained under the following conditions was defined as the solvent content. 46.3cm as film area²Was cut into 5 mm pieces, stored in a special vial, sealed with a septum and an aluminum cap, and then set in a head space sampler HP7694 type gas chromatography (GC) 5971 manufactured by Hewlett-Packard Company. A GC ion detector (FID) was used as a GC detector, and DB-624 manufactured by J & W was used as a column. As main measurement conditions, the headspace sampler heating conditions were 120 ° C. and 20 minutes, and the GC introduction temperature was 150 ° C. and 8 ° C./min. The calibration curve was prepared using the peak area of the chromatogram obtained by measuring in the same manner as described above after storing a fixed amount of the butanol-diluted solution of each solvent in a dedicated vial. The solvent content of the photosensitive material is 40 mg / m²Met.
Photosensitive material 100cm²And the photosensitive layer was peeled off in MEK. Sulfuric acid was decomposed with Microdigest A300 type microwave digestion apparatus manufactured by Prolaboratory, and analyzed by the calibration curve method with PQ-Ω type ICP-MS (Inductively Coupled Plasma Mass Spectrometer) manufactured by VG Elemental. The Zr content in the photosensitive material was 10 μg or less per 1 mg of Ag.
[0209]
Embedded image
[0210]
<< Exposure and development process >>
An exposure machine using a semiconductor laser having a longitudinal multimode wavelength of 800 nm to 820 nm by high frequency superposition as an exposure source was prototyped, and exposure by laser scanning was performed from the emulsion surface side of the photosensitive material produced as described above. Gave. At this time, an image was recorded by setting the incident angle of the scanning laser beam to the exposure surface of the photosensitive material as 75 degrees. Thereafter, an automatic heat developing machine having a heat drum was used so that the protective layer of the photosensitive material and the drum surface were in contact with each other, and heat development was performed at 123 ° C. for 14 seconds, and the obtained image was evaluated with a densitometer. At that time, the exposed and developed room was 23 ° C. and 50% RH.
[0211]
<Continuous output evaluation>
The photographic properties of the first sheet and the 100th sheet when 100 samples are passed through are evaluated, and the density value of the 100th sheet sample is measured with an exposure amount giving density = 1.2 on the first sheet. The density difference from the first sheet was evaluated. The smaller the density difference, the better the processing stability and the preferred direction.
[0212]
[Table 6]
[0213]
The results in Table 6 indicate that the photothermographic material of the present invention has better processing stability during continuous output than the comparative example.
[0214]
【The invention's effect】
According to the present invention, it is possible to provide a high-sensitivity photothermographic material aimed at shortening the heat development time and an image forming method for stabilizing an output image at the time of continuous output using the same.

Claims (6)

In the photothermographic material containing at least one type of photosensitive silver halide, non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one side of the support,
Containing at least one polyphenol compound represented by the following general formula (I) as the reducing agent,
Containing at least one compound represented by the following general formula (II),
A photothermographic material wherein the photosensitive silver halide is infrared sensitized.
(In General Formula (I), R ¹¹ and R ¹¹ ′ each independently represent an alkyl group having 1 to 20 carbon atoms. R ¹² and R ¹² ′ are each independently a substituent capable of substituting for a hydrogen atom or a benzene ring. the representative .L -S- group or a -CHR ¹³ - group ^{.R 13} is a hydrogen atom or a benzene ring .X ¹ and ^{X 1} 'each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms Represents a substitutable group.)
(In the general formula (II), ^{Q 1} is a pyrimidine ring binds to ^{NHNH-R 1,} or represents a benzene ring or unsaturated hetero ring to the pyrimidine ring is fused rings, ^{R 1} is to display the substituted carbamoyl group.) 2. The photothermographic material according to claim 1, wherein Q1 represents a quinazoline ring. In the compound represented by the general formula (II) , R ¹ is a substituted carbamoyl group represented by —CO—NH—R ¹ ′, and R ¹ ′ is an alkyl group having 1 to 10 carbon atoms or aryl The photothermographic material according to claim 1 , wherein the photothermographic material represents a group. The photothermographic material according to any one of claims 1 to 3 in which the molecular weight of the compound represented by the general formula (I) is characterized in that 350 or less. An image forming method, wherein the photothermographic material according to claim 1 is exposed with a laser beam having an exposure wavelength of 750 nm to 1400 nm. An image forming method, wherein the photothermographic material according to any one of claims 1 to 4 is subjected to heat development processing with a heat development processing time of 10 seconds to 15 seconds.