JP4024100B2 - Photothermographic material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photothermographic material, and more particularly to an improved photothermographic material that has a small change in color tone with respect to fluctuations in heat development temperature and heat development time, and gives a stable finish.
[0002]
[Prior art]
In recent years, in the medical field, reduction of waste processing liquid has been strongly desired from the viewpoint of environmental protection and space saving. Therefore, photosensitive heat for medical diagnosis and photographic technology that can be efficiently exposed by a laser image setter or laser imager and can form a clear black image having high resolution and sharpness. There is a need for techniques relating to developed photographic materials. These photosensitive photothermographic materials eliminate the use of solution processing chemicals and can provide customers with a simpler heat development processing system that does not damage the environment.
[0003]
Although there is a similar requirement in the field of general image forming materials, medical images are required to have high image quality with excellent sharpness and graininess because they are required to be finely drawn, and are cooled from the viewpoint of ease of diagnosis. There is a feature that a black tone 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. However, there is no satisfactory output system for medical images.
[0004]
On the other hand, thermal imaging systems using organic silver salts are disclosed in, for example, the specifications of U.S. Pat. Nos. 3,152,904 and 3,457,075 and B.I. "Thermally Processed Silver Systems" by Shely (Imaging Processes and Materials Neblette 8th Edition, Sturge, V. Walworth (Walworth, A. Shepp, edited, page 2, 1996). In particular, the photothermographic material generally contains a catalytically active amount of a photocatalyst (eg, silver halide), a reducing agent, a reducible silver salt (eg, an organic silver salt), and a color tone that controls the color tone of silver if necessary. 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 blackened by a redox reaction between silver halide or a reducible silver salt (functioning as an oxidizing agent) and a reducing agent. Form a silver image. 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. Fuji Medical Dry Imager FM-DP L has been released as a medical image forming system using a photothermographic material disclosed in many documents including US Pat. No. 2910377 and Japanese Examined Patent Publication No. 43-4924.
[0005]
In manufacturing a thermal image forming system using an organic silver salt, there are a method of manufacturing by solvent coating and a method of manufacturing by coating and drying a coating liquid containing polymer fine particles as a water dispersion as a main binder. Since the latter method does not require a process such as solvent recovery, the manufacturing equipment is simple and it is advantageous for mass production.
[0006]
In the photothermographic material, an image is formed with developed silver particles generated by heat development. It is known that the color tone of developed silver changes depending on its form and surface condition. Diagnostic images in the medical field tend to favor cold black tone, i.e., bluish silver images, due to their high diagnostic capabilities, and various studies have been conducted to control the silver tone. For example, Japanese Patent Application Laid-Open No. 2000-241927 describes a method for controlling the silver tone by adjusting the contents of ammonium ions and sodium ions in a light-sensitive material. This method makes it possible to control the color tone to some extent, but at the same time as increasing the sodium ion ratio to make it yellow, the cyan color decreases, and there is a limit to freely controlling the color tone. In addition, photographic performance such as sensitivity and maximum image density is also affected at the same time, and the practical application range is limited.
[0007]
Japanese Patent Laid-Open No. 2001-188314 discloses a method for controlling the color tone of an image by selecting the type of reducing agent. Furthermore, Japanese Patent Application Laid-Open No. 2002-169249 describes a method of controlling the color tone of an image by using a hindered phenol compound in combination. If these methods are used, the image tone can be controlled to a preferable tone, and the control range can be greatly expanded by combining the adjustment with the sodium ion and ammonium ion as described above. It can be said that.
[0008]
However, the color tone adjusted by these methods gives a desired preferable color tone under a certain development condition, but the color tone changes when the development condition changes, that is, when the development temperature or development time changes, and the preferred range. It turned out that there was a problem of deviating from. Although the development temperature and time are controlled by a thermal developing machine, some fluctuations and variations are unavoidable, and there is a high possibility of causing variations in the finished color tone in the market. There is also a problem that strict specifications are required for the heat developing machine and the cost load increases.
[0009]
[Problems to be solved by the invention]
Accordingly, a first object of the present invention is to provide a method for stably controlling the color tone of a finished image of a heat-developable photosensitive material. A second object of the present invention is to provide a photothermographic material that is less susceptible to changes in image color tone due to fluctuations in heat development temperature and heat development time, and that always enables a stable finish.
[0010]
[Means for Solving the Problems]
  The object of the present invention has been achieved by the following photothermographic materials.
1) In a photothermographic material containing photosensitive silver halide, non-photosensitive organic silver salt, a reducing agent for heat development and a binder on the same surface of the support, heat is used as a reducing agent for the heat development. Reducing agent that does not form a dye during developmentAs a compound represented by the following general formula (R1)Reducing agent that forms a pigment with at least one ofAs a compound represented by the following general formula (R2)A photothermographic material containing at least one of the following:
Formula (R1)
[0011]
[Chemical formula 5]
[0012]
(Wherein R₁₁And R₁₂Each independently represents a secondary or tertiary alkyl group, and R₁₃And R₁₄Each independently represents an alkyl group having 2 or more carbon atoms, R₁₅Represents an alkyl group. )
General formula (R2)
[0013]
[Chemical 6]
[0014]
(Wherein R_{twenty one}And R_{twenty two}Represents a secondary or tertiary alkyl group, R_{twenty three}And R_{twenty four}Each independently represents a hydrogen atom, a hydroxy group, an alkoxy group, an aryloxy group, an acyloxy group, an amino group or a heterocyclic group. R_{twenty five}Represents a hydrogen atom or an alkyl group. ).
2)  SaidThe reducing agent represented by the general formula (R2) is based on the total reducing agent.5 mol% or more40 mol% or less1)The photothermographic material described in 1.
3)  2. The photothermographic material according to 2), wherein the reducing agent represented by the general formula (R2) is from 10 mol% to 30 mol% with respect to the total reducing agent.
4) Further characterized by containing a development accelerator.1)~ 3)The photothermographic material described in 1.
5)SaidThe development accelerator is a compound represented by the following general formula (A-1) or / and (A-2)4)The photothermographic material described in 1.
    Formula (A-1)
    Q1-NHNH-Q2
(In the formula, Q1 represents an aromatic group or a heterocyclic group bonded to —NHNH—Q2 at a carbon atom, and Q2 represents a carbamoyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfonyl group, or a sulfamoyl group. Represents.)
[0015]
[Chemical 7]
[0016]
  (Wherein R₁Represents an alkyl group, an acyl group, an acylamino group, a sulfonamide group, an alkoxycarbonyl group, a carbamoyl group, and R₂Represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyloxy group, or a carbonate group. R_ThreeAnd R_FourRepresents a substitutable group on the benzene ring and may be linked to each other to form a condensed ring. )
6) Further characterized by containing a hydrogen bonding compound1)~5One ofThe photothermographic material described in 1.
7) The hydrogen bonding compound is a compound represented by the following general formula (D):6)The photothermographic material described in 1.
Formula (D)
[0017]
[Chemical 8]
[0018]
  (Wherein R^{twenty one}Or 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. )
8) It contains a compound represented by the following general formula (H)1)~7One ofThe photothermographic material described in 1.
General formula (H)
      Q- (Y) n-C (Z₁) (Z₂) X
(Wherein 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. )
9) Total coated silver amount is 1.9g / m²It is characterized by1)~8One ofThe photothermographic material described in 1.
10) The heat development time is 16 seconds or less.1)~ 9)The photothermographic material described in 1.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
(Description of reducing agent)
The present inventors have intensively studied to achieve the object of the present invention. As a result, the reducing agent represented by the following general formula (R1) does not give a coloring component in the light-sensitive material, whereas the compound represented by the following general formula (R2) is colored yellow. It was found that the image color tone can be controlled by using the reducing agent of the general formula (R1) and the reducing agent of the general formula (R2) in combination. In addition, by selecting and combining a reducing agent of the general formula (R2) having a higher activity with a reducing agent of the general formula (R1) having a lower activity, the variation in color tone with respect to the development temperature and development time is remarkably increased. It has been found that it can be reduced.
Furthermore, it has been found that the image formed in this way has a surprising effect that the change in color tone with respect to light and heat with time is remarkably reduced.
[0020]
(Reducing agent represented by the general formula (R1))
First, the reducing agent represented by the general formula (R1) of the present invention will be described in detail.
Formula (R1)
[0021]
[Chemical 9]
[0022]
In the general formula (R1), R₁₁And R₁₂Each independently represents a secondary or tertiary alkyl group, and R₁₃And R₁₄Each independently represents an alkyl group having 2 or more carbon atoms, R₁₅Represents an alkyl group.
[0023]
R₁₁And R₁₂Is preferably a secondary or tertiary alkyl group having 3 to 20 carbon atoms and may have a substituent. The substituent of the alkyl group is not particularly limited, but preferably an aryl group, a hydroxy group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acylamino group, a sulfonamido group, a sulfonyl group, a phosphoryl group, Examples thereof include an acyl group, a carbamoyl group, an ester group, a ureido group, a urethane group, and a halogen atom.
[0024]
R₁₃And R₁₄Is preferably an alkyl group having 2 to 20 carbon atoms, and R₁₁And may have the same substituent.
R₁₅Is preferably an alkyl group having 1 to 20 carbon atoms, and R₁₁And may have the same substituent.
[0025]
R₁₁And R₁₂More preferably, it is a secondary or tertiary alkyl group having 3 to 15 carbon atoms, specifically, 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. R₁₁And R₁₂More preferably a tertiary alkyl group having 4 to 12 carbon atoms, among which a t-butyl group, a t-amyl group and a 1-methylcyclohexyl group are more preferred, and a t-butyl group is most preferred.
[0026]
R₁₃And R₁₄More preferably an alkyl group having 2 to 15 carbon atoms, specifically, an ethyl group, a propyl group, a butyl group, an isopropyl group, an isobutyl group, a sec-butyl group, a t-butyl group, a t-amyl group, a cyclohexyl group. Group, 1-methylcyclohexyl group, cyclohexylmethyl group, benzyl group, methoxyethyl group, methoxybutyl group, N, N-dimethylaminoethyl group and the like. More preferred are ethyl group, propyl group, butyl group, isopropyl group and t-butyl group. Particularly preferred are ethyl and propyl, with ethyl being most preferred.
[0027]
R₁₅More preferably an alkyl group having 1 to 15 carbon atoms, specifically a methyl group, an ethyl group, a propyl group, a butyl group, a heptyl group, an undecyl group, an isopropyl group, a 1-ethylpentyl group, 2, 4, Examples include 4-trimethylpentyl group, methoxymethyl group, methoxypropyl group, butoxyethyl group, 2-acetylaminoethyl group, 2-phenylthioethyl group, 2-dodecylthioethyl group and the like. More preferably, it is an alkyl group having 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, and an isobutyl group. Among them, a methyl group, an ethyl group, and a propyl group are preferable, and a methyl group is preferable. Most preferred.
[0028]
The compound represented by the general formula (R1) of the present invention is a compound that does not form a yellow dye during heat development. Specific examples of the reducing agent of the present invention represented by the general formula (R1) of the present invention are shown below, but the present invention is not limited thereto.
[0029]
[Chemical Formula 10]
[0030]
Embedded image
[0031]
(Reducing agent represented by the general formula (R2))
Next, the reducing agent represented by the general formula (R2) of the present invention will be described in detail.
General formula (R2)
[0032]
Embedded image
[0033]
  In the general formula (R2), R_{twenty one}And R_{twenty two}Each independently represents a secondary or tertiary alkyl group, and R_{twenty three}And R_{twenty four}Each independently represents a hydrogen atom, a hydroxy group, an alkoxy group, an aryloxy group, an acyloxy group, an amino group or a heterocyclic group..R_{twenty five}Is, Hydrogen atom orRepresents an alkyl group.
[0034]
R_{twenty one}And R_{twenty two}Is preferably a secondary or tertiary alkyl group having 3 to 20 carbon atoms and may have a substituent. The substituent of the alkyl group is not particularly limited, but preferably an aryl group, a hydroxy group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acylamino group, a sulfonamido group, a sulfonyl group, a phosphoryl group, Examples thereof include an acyl group, a carbamoyl group, an ester group, a ureido group, a urethane group, and a halogen atom.
[0035]
R_{twenty three}And R_{twenty four}Is preferably a hydrogen atom, an alkyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an alkylamino group having 2 to 20 carbon atoms, or 6 to 20 carbon atoms. An anilino group, an alkylthio group having 1 to 20 carbon atoms, an arylthio group having 6 to 20 carbon layers, an acyloxy group having 1 to 20 carbon atoms, or a heterocyclic group having 3 to 20 carbon atoms, and R_{twenty one}And may have the same substituent.
R_{twenty five}Is preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and R_{twenty one}And may have the same substituent.
[0036]
R_{twenty one}And R_{twenty two}More preferably, it is a secondary or tertiary alkyl group having 3 to 15 carbon atoms, specifically, 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. R_{twenty one}And R_{twenty two}More preferably a tertiary alkyl group having 4 to 12 carbon atoms, among which a t-butyl group, a t-amyl group and a 1-methylcyclohexyl group are more preferred, and a t-butyl group is most preferred.
[0037]
R_{twenty three}And R_{twenty four}More preferably, it is an alkyl group having 1 to 15 hydrogen atoms, hydroxy group, alkoxy group, aryloxy group or amino group, specifically hydrogen atom, hydroxyl group, methoxy group, ethoxy group, butoxy group, octyl Examples thereof include an oxy group, a methoxyethoxy group, a cyclohexyloxy group, a phenoxy group, an N, N-dimethylamino group, an N, N-dibutylamino group, an N-methylanilino group, and a piperidinyl group. More preferred are a hydrogen atom, a methoxy group, and an N, N-dimethylamino group, and a hydrogen atom is most preferred.
[0038]
R_{twenty five}More 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, a butyl group, a heptyl group, an undecyl group, an isopropyl group, or 1-ethylpentyl. Group, 2,4,4-trimethylpentyl group, methoxymethyl group, methoxypropyl group, butoxyethyl group, 2-acetylaminoethyl group, 2-phenylthioethyl group, 2-dodecylthioethyl group and the like. More preferably, it is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and examples thereof include a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, and an isobutyl group, and among them, a hydrogen atom, a methyl group, and an ethyl group A propyl group is preferable, and a hydrogen atom or a methyl group is most preferable.
[0039]
The compound represented by the general formula (R2) of the present invention is a compound that forms a yellow dye during heat development, although there are some differences depending on the structure. Specific examples of the reducing agent of the present invention represented by the general formula (R2) of the present invention are shown below, but the present invention is not limited thereto.
[0040]
Embedded image
[0041]
Embedded image
[0042]
Examples of preferable reducing agents of the present invention other than those described above are compounds that fall within the definition of the present invention among the compounds described in JP-A Nos. 2001-188314, 2001-209145, 2001-350235, and 2002-156727. It is.
In the present invention, the total addition amount of the reducing agents of the general formulas (R1) and (R2) is 0.1 to 3.0 g / m.²And more preferably 0.2 to 1.5 g / m.²And more preferably 0.3 to 1.0 g / m²It is. It is preferably contained in an amount of 5 to 50% by mole, more preferably 8 to 30% by mole, and further preferably 10 to 20% by mole based on 1 mole of silver on the surface having the image forming layer. The reducing agent is preferably contained in the image forming layer.
It is preferable to use the reducing agent (R1) of the present invention in a molar amount relative to the reducing agent (R2) of the present invention. More preferably, the reducing agent (R2) is in the range of 5 to 40 mol%, more preferably in the range of 10 to 30 mol% with respect to the total amount of reducing agent.
[0043]
The relative relationship of the development activity of the reducing agent of the present invention can be evaluated from the relative relationship of sensitivity when the reducing agent of the present invention is used alone in the configuration in which the reducing agent of the present invention is used. In the present invention, the logarithmic value (−LogE) of the exposure amount E that gives the density 1.5 to the reducing agent B represented by the general formula (R1) is represented by the reducing agent A represented by the general formula (R2). If it is larger than 0.02, it can be judged that the reducing agent A has higher development activity than the reducing agent B. In the present invention, the reducing agent of the general formula (R2) is preferably 0.03 or more in relative value of sensitivity than the reducing agent of the general formula (R1), more preferably 0.05 or more, still more preferably 0.08. That's big. The larger the difference in relative sensitivity, the smaller the ratio of the compound of general formula (R2) used. When the relative sensitivity difference is 0.05 or more, the ratio of the reducing agent of general formula (R2) is preferably 30 mol% or less, When the relative sensitivity difference is 0.10 or more, the ratio of the reducing agent of the general formula (R2) is preferably 20 mol% or less.
[0044]
The reducing agent of the present invention 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 dispersing the emulsified dispersion. The method of producing is mentioned.
[0045]
In addition, as a solid fine particle dispersion method, a reducing agent powder is dispersed in an appropriate solvent such as water by a ball mill, a colloid mill, a vibration ball mill, a sand mill, a jet mill, a roller mill, or an ultrasonic wave to create a solid dispersion. A method is mentioned. In this case, a protective colloid (for example, polyvinyl alcohol) or a surfactant (for example, an anionic surfactant such as sodium triisopropylnaphthalenesulfonate (a mixture of three isopropyl groups having different substitution positions)) may be used. Good. In the mills, beads such as zirconia are usually used as a dispersion medium, and Zr and the like eluted from these beads may be mixed in the dispersion. Although it depends on the dispersion conditions, it is usually in the range of 1 ppm to 1000 ppm. If the content of Zr in the light-sensitive material is 0.5 mg or less per 1 g of silver, there is no practical problem.
The aqueous dispersion preferably contains a preservative (for example, benzoisothiazolinone sodium salt).
In the present invention, the reducing agent is preferably used as a solid dispersion.
[0046]
In the present invention, conventionally known reducing agents for organic silver salts may be used in combination with the above two kinds of reducing agents. Examples of these reducing agents are described in JP-A No. 11-65021, paragraph numbers 0043 to 0045, and European Patent Publication No. 803764A1, page 7, line 34 to page 18, line 12. In particular, it is preferable to use a hindered phenol reducing agent having a locating group at the ortho position of the phenolic hydroxyl group or a bisphenol reducing agent in combination.
[0047]
(Description of organic silver salt)
1) Composition
Organic silver salts that can be used in the present invention are relatively stable to light, but when heated to 80 ° C. or higher in the presence of exposed photosensitive silver halide and reducing agent. It is a silver salt that functions as a silver ion supplier and forms a silver image. The organic silver salt may be any organic substance that can supply silver ions that can be reduced by a reducing agent. Regarding such non-photosensitive organic silver salt, paragraph numbers 0048 to 0049 of JP-A No. 10-62899, page 18 line 24 to page 19 line 37 of European Patent Publication No. 080864A1, European Patent Publication No. 0962812A1, JP-A-11-349591, JP-A-2000-7683, JP-A-2000-72711, and the like. Silver salts of organic acids, particularly silver salts of long-chain aliphatic carboxylic acids (having 10 to 30, preferably 15 to 28 carbon atoms) are preferred. Preferred examples of the fatty acid silver salt include lignoceric acid, silver behenate, silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, silver erucate and the like. Including mixtures. In the present invention, among these fatty acid silvers, the silver behenate content is preferably 50 mol% to 100 mol%, more preferably 85 mol% to 100 mol%, still more preferably 95 mol% to 100 mol%. The following fatty acid silver is preferably used. Furthermore, it is preferable to use fatty acid silver having an erucic acid content of 2 mol% or less, more preferably 1 mol% or less, and even more preferably 0.1 mol% or less.
[0048]
Moreover, it is preferable that silver stearate content rate is 1 mol% or less. By making the stearic acid content 1 mol% or less, a silver salt of an organic acid having a low Dmin, high sensitivity and excellent image storage stability can be obtained. As said stearic acid content rate, 0.5 mol% or less is preferable and it is especially preferable not to contain substantially.
[0049]
Furthermore, when silver arachidate is included as the silver salt of the organic acid, the silver arachidate content is 6 mol% or less to obtain a low Dmin and an organic acid silver salt excellent in image storability. It is preferable at a point and it is still more preferable that it is 3 mol% or less.
[0050]
2) Shape
The shape of the organic silver salt that can be used in the present invention is not particularly limited, and may be any of a needle shape, a rod shape, a flat plate shape, and a flake shape.
In the present invention, scaly organic silver salts are preferred. Also, short needle-shaped, rectangular parallelepiped, cubic or potato-shaped amorphous particles having a major axis / uniaxial length ratio of 5 or less are preferably used. These organic silver particles have a feature that there is less fog at the time of thermal development than long needle-like particles having a ratio of the major axis to the uniaxial length of 5 or more. In particular, particles having a major axis / uniaxial ratio of 3 or less are preferable because the mechanical stability of the coating film is improved. In the present specification, the scaly organic silver salt is defined as follows. The organic acid silver salt was observed with an electron microscope, 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
[0051]
In this way, x is obtained for about 200 particles, and when the average value x (average) is obtained, particles satisfying the relationship of x (average) ≧ 1.5 are defined as flakes. Preferably, 30 ≧ x (average) ≧ 1.5, more preferably 15 ≧ x (average) ≧ 1.5. Incidentally, the needle shape is 1 ≦ x (average) <1.5.
[0052]
In the flake shaped particle, a can be regarded as a thickness of a tabular particle having a main plane with b and c as sides. The average of a is preferably 0.01 μm or more and 0.3 μm or less, and more preferably 0.1 μm or more and 0.23 μm or less. The average c / b is preferably 1 or more and 9 or less, more preferably 1 or more and 6 or less, still more preferably 1 or more and 4 or less, and most preferably 1 or more and 3 or less.
[0053]
By setting the equivalent sphere diameter to 0.05 μm or more and 1 μm or less, aggregation is hardly caused in the photosensitive material, and image storability is improved. The sphere equivalent diameter is preferably 0.1 μm or more and 1 μm or less. In the present invention, the method for measuring the equivalent sphere diameter is obtained by directly photographing a sample using an electron microscope and then image-processing the negative.
In the flake shaped particles, the spherical equivalent diameter / a of the particles is defined as the aspect ratio. The aspect ratio of the flake shaped particles is preferably 1.1 or more and 30 or less, more preferably 1.1 or more and 15 or less, from the viewpoint of preventing aggregation in the photosensitive material and improving the image storage stability. .
[0054]
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, respectively. 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 of 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 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 temporal change of fluctuation of the scattered light. Can do.
[0055]
3) Preparation
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, the above-mentioned JP-A-10-62899, European Patent Publication No. 0803633A1, European Patent Publication No. 0962812A1, JP-A-11-349591, JP-A-2000-7683, JP-A-2000-72711, JP-A-2001-163889, 2001-163890, 2001-163827, 2001-33907, 2001-188313, 2001-83652, 2002-6442, 2002-49117, 2002-31870, 2002-107868 You can refer to the issue.
[0056]
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 preferably 1 mol% or less, more preferably 0.1 mol% or less, based on 1 mol of the organic acid silver salt in the liquid. More preferably, no active addition of photosensitive silver salt is performed.
[0057]
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 2 to 20 mol%, particularly preferably 3 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.
[0058]
4) Addition amount
The organic silver salt of the present invention can be used in a desired amount, but the total coated silver amount including silver halide is 0.1 to 5.0 g / m.²Is more preferable, 0.3 to 3.0 g / m2, more preferably 0.5 to 2.0 g / m2.²It is. In particular, in order to improve image storage stability, the total amount of silver applied is preferably 1.8 g / m 2 or less, more preferably 1.6 g / m 2. If the preferred reducing agent of the present invention is used, it is possible to obtain a sufficient image density even with such a low silver amount.
[0059]
(Description of development accelerator)
In the photothermographic material of the present invention, a sulfonamide phenol compound represented by the general formula (A) described in JP-A-2000-267222, JP-A-2000-330234, etc. as a development accelerator, Hindered phenol compounds represented by general formula (II) described in JP-A-2001-92075, general formula (I) described in JP-A-10-62895 and JP-A-11-15116, A hydrazine-based compound represented by general formula (D) in JP-A-2002-156727 or general formula (1) described in Japanese Patent Application No. 2001-074278, described in JP-A-2001-264929 A phenolic or naphtholic compound represented by the general formula (2) is preferably used. These development accelerators are used in the range of 0.1 to 20 mol% with respect to the reducing agent, preferably in the range of 0.5 to 10 mol%, more preferably in the range of 1 to 5 mol%. The introduction method to the light-sensitive material includes the same method as the reducing agent, but it is particularly preferable to add as a solid dispersion or an emulsified dispersion. When added as an emulsified dispersion, it is added as an emulsified dispersion dispersed using a high-boiling solvent and a low-boiling auxiliary solvent that are solid at room temperature, or as a so-called oilless emulsified dispersion that does not use a high-boiling solvent. It is preferable to add.
In the present invention, among the above development accelerators, hydrazine compounds represented by the general formula (D) described in JP-A No. 2002-156727 and those described in JP-A No. 2001-264929 A phenol-based or naphthol-based compound represented by the formula (2) is more preferable.
[0060]
Particularly preferred development accelerators of the present invention are compounds represented by the following general formulas (A-1) and (A-2).
Formula (A-1)
Q1-NHNH-Q2
(In the formula, Q1 represents an aromatic group or a heterocyclic group bonded to —NHNH—Q2 at a carbon atom, and Q2 represents a carbamoyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfonyl group, or a sulfamoyl group. Represents.)
[0061]
In the general formula (A-1), the aromatic group or heterocyclic group represented by Q1 is preferably a 5- to 7-membered unsaturated ring. Preferred examples include benzene ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, 1,2,4-triazine ring, 1,3,5-triazine ring, pyrrole ring, imidazole ring, pyrazole ring, 1,2 , 3-triazole ring, 1,2,4-triazole ring, tetrazole ring, 1,3,4-thiadiazole ring, 1,2,4-thiadiazole ring, 1,2,5-thiadiazole ring, 1,3,4 -Oxadiazole ring, 1,2,4-oxadiazole ring, 1,2,5-oxadiazole ring, thiazole ring, oxazole ring, isothiazole ring, isoxazole ring, thiophene ring, etc. are preferable, and these Also preferred are fused rings in which the rings are fused together.
[0062]
These rings may have a substituent, and when they have two or more substituents, these substituents may be the same or different. Examples of substituents include halogen atoms, alkyl groups, aryl groups, carbonamido groups, alkylsulfonamido groups, arylsulfonamido groups, alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, carbamoyl groups, sulfamoyl groups, cyano Groups, alkylsulfonyl groups, arylsulfonyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, and acyl groups. When these substituents are substitutable groups, they may further have substituents. Examples of preferred substituents include halogen atoms, alkyl groups, aryl groups, carbonamido groups, alkylsulfonamido groups, aryls. Sulfonamide group, alkoxy group, aryloxy group, alkylthio group, arylthio group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, cyano group, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, and acyloxy group Can be mentioned.
[0063]
The carbamoyl group represented by Q2 is preferably a carbamoyl group having 1 to 50 carbon atoms, more preferably 6 to 40 carbon atoms, such as unsubstituted carbamoyl, methylcarbamoyl, N-ethylcarbamoyl, N-propylcarbamoyl, N-sec-butylcarbamoyl, N-octylcarbamoyl, N-cyclohexylcarbamoyl, N-tert-butylcarbamoyl, N-dodecylcarbamoyl, N- (3-dodecyloxypropyl) carbamoyl, N-octadecylcarbamoyl, N- {3- (2,4-tert-pentylphenoxy) propyl} carbamoyl, N- (2-hexyldecyl) carbamoyl, N-phenylcarbamoyl, N- (4-dodecyloxyphenyl) carbamoyl, N- (2-chloro-5-dodecyl) Oxycarboni Ruphenyl) carbamoyl, N-naphthylcarbamoyl, N-3-pyridylcarbamoyl, N-benzylcarbamoyl.
[0064]
The acyl group represented by Q2 is preferably an acyl group having 1 to 50 carbon atoms, more preferably 6 to 40 carbon atoms. For example, formyl, acetyl, 2-methylpropanoyl, cyclohexylcarbonyl, octanoyl, 2- Examples include hexyldecanoyl, dodecanoyl, chloroacetyl, trifluoroacetyl, benzoyl, 4-dodecyloxybenzoyl, and 2-hydroxymethylbenzoyl. The alkoxycarbonyl group represented by Q2 is preferably an alkoxycarbonyl group having 2 to 50 carbon atoms, more preferably 6 to 40 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, isobutyloxycarbonyl, cyclohexyloxycarbonyl, dodecyl. Examples include oxycarbonyl and benzyloxycarbonyl.
[0065]
The aryloxycarbonyl group represented by Q2 is preferably an aryloxycarbonyl group having 7 to 50 carbon atoms, more preferably 7 to 40 carbon atoms, such as phenoxycarbonyl, 4-octyloxyphenoxycarbonyl, 2-hydroxymethyl. Phenoxycarbonyl and 4-dodecyloxyphenoxycarbonyl are mentioned. The sulfonyl group represented by Q2 is preferably a sulfonyl group having 1 to 50 carbon atoms, more preferably 6 to 40 carbon atoms, such as methylsulfonyl, butylsulfonyl, octylsulfonyl, 2-hexadecylsulfonyl, 3-dodecyl. Examples include oxypropylsulfonyl, 2-octyloxy-5-tert-octylphenylsulfonyl, and 4-dodecyloxyphenylsulfonyl.
[0066]
The sulfamoyl group represented by Q2 is preferably a sulfamoyl group having 0 to 50 carbon atoms, more preferably 6 to 40 carbon atoms, such as unsubstituted sulfamoyl, N-ethylsulfamoyl group, N- (2-ethylhexyl). ) Sulfamoyl, N-decylsulfamoyl, N-hexadecylsulfamoyl, N- {3- (2-ethylhexyloxy) propyl} sulfamoyl, N- (2-chloro-5-dodecyloxycarbonylphenyl) sulfamoyl, N -(2-tetradecyloxyphenyl) sulfamoyl is mentioned. The group represented by Q2 may further have two or more groups listed as examples of the substituent of the 5- to 7-membered unsaturated ring represented by Q1 at the substitutable position. In the case of having a substituent, these substituents may be the same or different.
[0067]
Next, a preferable range of the compound represented by formula (A-1) is described. Q1 is preferably a 5- to 6-membered unsaturated ring, such as a benzene ring, pyrimidine ring, 1,2,3-triazole ring, 1,2,4-triazole ring, tetrazole ring, 1,3,4-thiadiazole ring, 1,2,4-thiadiazole ring, 1,3,4-oxadiazole ring, 1,2,4-oxadiazole ring, thiazole ring, oxazole ring, isothiazole ring, isoxazole ring, and these rings More preferred is a ring fused with a benzene ring or an unsaturated heterocycle. Q2 is preferably a carbamoyl group, particularly preferably a carbamoyl group having a hydrogen atom on the nitrogen atom.
[0068]
Formula (A-2)
[0069]
Embedded image
[0070]
In the general formula (A-2), R₁Represents an alkyl group, an acyl group, an acylamino group, a sulfonamide group, an alkoxycarbonyl group, or a carbamoyl group. R₂Represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acyloxy group, or a carbonate group. R_Three, R_FourEach represents a group capable of substituting for the benzene ring mentioned in the example of the substituent of formula (A-1). R_ThreeAnd R_FourMay be linked together to form a condensed ring.
R₁Is preferably an alkyl group having 1 to 20 carbon atoms (eg, methyl group, ethyl group, isopropyl group, butyl group, tert-octyl group, cyclohexyl group, etc.), acylamino group (eg, acetylamino group, benzoylamino group, methylureido). Groups, 4-cyanophenylureido groups, etc.), carbamoyl groups (n-butylcarbamoyl group, N, N-diethylcarbamoyl group, phenylcarbamoyl group, 2-chlorophenylcarbamoyl group, 2,4-dichlorophenylcarbamoyl group, etc.) and acylamino groups (Including a ureido group and a urethane group) is more preferable.
R₂Is preferably a halogen atom (more preferably a chlorine atom or a bromine atom), an alkoxy group (for example, a methoxy group, a butoxy group, an n-hexyloxy group, an n-decyloxy group, a cyclohexyloxy group, a benzyloxy group), an aryloxy group (Phenoxy group, naphthoxy group, etc.).
R_ThreeIs preferably a hydrogen atom, a halogen atom, or an alkyl group having 1 to 20 carbon atoms, and most preferably a halogen atom. R_FourIs preferably a hydrogen atom, an alkyl group or an acylamino group, more preferably an alkyl group or an acylamino group. Examples of these preferred substituents are R₁It is the same. R_FourR is an acylamino group_FourIs R_ThreeIt is also preferred to form a carbostyryl ring by linking with.
[0071]
In the general formula (A-2), R_ThreeAnd R_FourAre connected to each other to form a condensed ring, the naphthalene ring is particularly preferable as the condensed ring. The same substituent as the example of a substituent quoted by general formula (A-1) may couple | bond with the naphthalene ring. When general formula (A-2) is a naphtholic compound, R₁Is preferably a carbamoyl group. Of these, a benzoyl group is particularly preferable. R₂Is preferably an alkoxy group or an aryloxy group, particularly preferably an alkoxy group.
[0072]
Hereinafter, preferred specific examples of the development accelerator of the present invention will be given. The present invention is not limited to these.
[0073]
Embedded image
[0074]
(Description of hydrogen bonding compound)
When the reducing agent in the present invention has an aromatic hydroxyl group (—OH) or amino group (—NHR, R is a hydrogen atom or an alkyl group), particularly in the case of the aforementioned bisphenols, these groups and hydrogen bonds It is preferable to use together a non-reducing compound having a group capable of forming.
Examples of the group that forms a hydrogen bond with a hydroxyl group or an amino group include a phosphoryl group, a sulfoxide group, a sulfonyl group, a carbonyl group, an amide group, an ester group, a urethane group, a ureido group, a tertiary amino group, and a nitrogen-containing aromatic group. Can be mentioned. Among them, preferred are a phosphoryl group, a sulfoxide group, an amide group (however, it does not have a> 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 (but does not have a> N—H group,> N-Ra (Ra is a substituent other than H).)
In the present invention, a particularly preferred hydrogen bonding compound is a compound represented by the following general formula (D).
Formula (D)
[0075]
Embedded image
[0076]
R in general formula (D)^{twenty one}Or 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}Or 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 and the like can be mentioned.
R^{twenty one}Or R^{twenty three}Specific examples of the alkyl group include methyl group, ethyl group, butyl group, octyl group, dodecyl group, isopropyl group, t-butyl group, t-amyl group, t-octyl group, cyclohexyl group, and 1-methylcyclohexyl group. Benzyl group, phenethyl group, 2-phenoxypropyl group, and the like.
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, and 3,5-dichlorophenyl group.
Alkoxy groups include methoxy, ethoxy, butoxy, octyloxy, 2-ethylhexyloxy, 3,5,5-trimethylhexyloxy, dodecyloxy, cyclohexyloxy, 4-methylcyclohexyloxy, benzyl An oxy group etc. are mentioned.
Examples of the aryloxy group include a phenoxy group, a cresyloxy group, an isopropylphenoxy group, a 4-t-butylphenoxy group, a naphthoxy group, and a biphenyloxy group.
Examples of the amino group include a dimethylamino group, a diethylamino group, a dibutylamino group, a dioctylamino group, an N-methyl-N-hexylamino group, a dicyclohexylamino group, a diphenylamino group, and an N-methyl-N-phenylamino group. .
[0077]
R^{twenty one}Or 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}Or 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}Or R^{twenty three}Are preferably the same group.
Specific examples of the hydrogen bonding compound including the compound of the general formula (D) in the present invention are shown below, but the present invention is not limited thereto.
[0078]
Embedded image
[0079]
Specific examples of the hydrogen bonding compound include those described in European Patent No. 1096310, Japanese Patent Application Laid-Open No. 2002-156727, and Japanese Patent Application No. 2001-124796 in addition to the above.
The compound of the general formula (D) of the present invention can be used in a light-sensitive material by being incorporated in a coating solution in the form of a solution, an emulsified dispersion, or a solid dispersion fine particle dispersion in the same manner as the reducing agent. It is preferable to use it as a product. The compound of the present invention forms a hydrogen-bonding complex with a compound having a phenolic hydroxyl group or an amino group in a solution state, and depending on the combination of the reducing agent and the compound of the general formula (D) 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 (D) of the present invention are mixed as a powder and complexed at the time of dispersion with a sand grinder mill or the like using an appropriate dispersant can be preferably used.
The compound of the general formula (D) 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%, still more preferably 20 to 100 mol, based on the reducing agent. % Range.
[0080]
(Description of silver halide)
1) Halogen composition
The photosensitive silver halide used in the present invention is not particularly limited as a halogen composition, and silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver iodochlorobromide, and silver iodide can be used. it can. Of these, silver bromide, silver iodobromide and silver iodide 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, and more preferably 2- to 4-fold core / shell particles can be used. A technique for localizing silver bromide or silver iodide on the surface of silver chloride, silver bromide or silver chlorobromide grains can also be preferably used.
[0081]
2) Particle formation method
Methods for forming photosensitive silver halide are well known in the art, for example, the methods described in Research Disclosure June 1978, No. 17029, and U.S. Pat.No. 3,700,458 can be used, Specifically, a method is used 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 JP-A Nos. 11-352627 and 2000-347335 are also preferable.
[0082]
3) Particle size
The grain size of the photosensitive silver halide is preferably small for the purpose of suppressing white turbidity after image formation, specifically 0.20 μm or less, more preferably 0.01 μm or more and 0.15 μm or less, and further preferably 0.02 μm or more. 0.12 μm or less is preferable. 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).
[0083]
4) Particle shape
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 grains is not particularly limited, but the proportion of the [100] surface that has high spectral sensitization efficiency when adsorbed by the spectral sensitizing dye 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 calculated by T. Tani; J. Imaging Sci., 29, 165 (1985), which uses the adsorption dependence of [111] plane and [100] plane in the adsorption of sensitizing dyes. It can be determined by the method described.
[0084]
5) Heavy metal
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.
[0085]
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 hexacyano metal complexes, [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.
[0086]
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 ion, tetraethylammonium ion, tetrapropylammonium ion, and tetra (n-butyl) ammonium ion).
[0087]
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.
[0088]
The amount of hexacyano metal complex added is 1 x 10 per mole of silver.^-FiveMore than mole 1 × 10^-2Or less, more preferably 1 × 10^-FourMore than mole 1 × 10^-3It is below the mole.
[0089]
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.
[0090]
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.
[0091]
When these hexacyanometal complexes are added after the addition of the aqueous silver nitrate solution just before the completion of grain formation, they can be adsorbed on the outermost surface of the silver halide grains, and most of them form slightly soluble salts with silver ions on the grain surface. To do. Since this silver salt of hexacyanoiron (II) is a less soluble salt than AgI, it is possible to prevent re-dissolution by fine particles and to produce silver halide fine particles having a small particle size. .
[0092]
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, paragraph number 0242 of JP-A-11-119374 ~ 0250.
[0093]
6) Gelatin
Various gelatins can be used as the gelatin contained in the photosensitive silver halide emulsion used in the present invention. It is necessary to maintain the dispersion state of the photosensitive silver halide emulsion in the organic silver salt-containing coating solution, and gelatin having a molecular weight of 10,000 to 1,000,000 is preferably used. It is also preferable to phthalate the gelatin substituent. These gelatins may be used at the time of grain formation or at the time of dispersion after desalting, but are preferably used at the time of grain formation.
[0094]
7) Sensitizing dye
As a sensitizing dye that can be applied to the present invention, it can spectrally sensitize silver halide grains in a desired wavelength region when adsorbed on silver halide grains, and has a spectral sensitivity suitable for the spectral characteristics of the exposure light source. The dye can be advantageously selected. As for the sensitizing dye and the addition method, paragraphs 0103 to 0109 of JP-A-11-65021, compounds represented by general formula (II) of JP-A-10-186572, and general formulas (I) of JP-A-11-119374 ) And the dyes described in paragraph No. 0106, U.S. Pat.Nos. 5,510,236 and 3,871,887 in Example 5, the dyes disclosed in JP-A-2-96131 and JP-A-59-48753, European Patent Publication No. 0808364A1 describes page 19 line 38 to page 20 line 35, JP-A-2001-272747, JP-A-2001-290238, JP-A-2002-23306, and the like. These sensitizing dyes may be used alone or in combination of two or more. In the present invention, the time when the sensitizing dye is added to the silver halide emulsion is preferably the time from the desalting step to the coating, and more preferably the time from desalting to the end of chemical ripening.
The addition amount of the sensitizing dye in the present invention can be set to a desired amount in accordance with the sensitivity and fogging performance, but is 10 per mol of silver halide in the photosensitive layer.^-6~ 1 mol is preferred, more preferably 10^-Four~Ten^-1Is a mole.
[0095]
In the present invention, a supersensitizer can be used to improve spectral sensitization efficiency. Examples of supersensitizers used in the present invention include European Patent Publication No. 587,338, U.S. Pat. And the compounds described.
[0096]
8) Chemical sensitization
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, for example, compounds described in JP-A-7-128768 and the like can be used. In the present invention, tellurium sensitization is particularly preferred, and the compounds described in the literature described in paragraph No. 0030 of JP-A-11-65021, the general formulas (II), (III), (IV) in JP-A-5-313284 The compound shown by is more preferable.
[0097]
The photosensitive silver halide grains in the present invention are preferably chemically sensitized by gold sensitization alone or in combination with the chalcogen sensitization described above. As the gold sensitizer, the valence of gold is preferably +1 or +3, and the gold sensitizer is preferably a commonly used gold compound. Typical examples are chloroauric acid, bromoauric acid, potassium chloroaurate, potassium bromoaurate, auric trichloride, potassium auric thiocyanate, potassium iodoaurate, tetracyanoauric acid, ammonium aurothiocyanate, pyridyltrichlorogold. Etc. are preferable. Further, gold sensitizers described in US Pat. No. 5,858,637 and Japanese Patent Application No. 2001-79450 are also preferably used.
[0098]
In the present invention, chemical sensitization is possible at any time after particle formation and before coating, and after desalting, (1) before spectral sensitization, (2) simultaneously with spectral sensitization, (3) spectral sensitization After sensitization, there may be (4) just before application.
The amount of sulfur, selenium and tellurium sensitizers used in the present invention varies depending on the silver halide grains used, chemical ripening conditions, etc., but is 10 per mol of silver halide.^-8-10^-2Moles, preferably 10^-7-10^-3Use about moles.
The amount of gold sensitizer added varies depending on various conditions, but as a guideline it is 10 per mole of silver halide.^-7From mole 10^-3Mole, more preferably 10^-6Mol ~ 5 × 10^-FourIs a mole.
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 described in European Patent Publication No. 293,917.
[0099]
A reducing agent is preferably used for the photosensitive silver halide grains in the present invention. As specific compounds for the reduction sensitization, ascorbic acid and thiourea dioxide are preferable, and in addition, stannous chloride, aminoiminomethanesulfinic acid, hydrazine derivatives, borane compounds, silane compounds, polyamine compounds, and the like are preferably used. . The reduction sensitizer may be added at any stage in the photosensitive emulsion production process from crystal growth to the preparation process immediately before coating. Further, reduction sensitization is preferred by ripening while maintaining the pH of the emulsion at 7 or higher or pAg at 8.3 or lower, and reduction sensitization is achieved by introducing a single addition portion of silver ions during grain formation. It is also preferable to do.
[0100]
The photosensitive silver halide emulsion in the invention preferably contains an FED sensitizer (Fragmentable electron donating sensitizer) as a compound that generates two electrons by one photon. As the FED sensitizer, compounds described in US Pat. Nos. 5,747,235, 5747236, 6054260, 599941, and Japanese Patent Application No. 2001-86161 are preferable. As the step of adding the FED sensitizer, any process of the photosensitive emulsion production process from crystal growth to the preparation process immediately before coating is preferable. The amount added varies depending on various conditions, but as a guideline, it is 10 per silver halide.^-7From mole 10^-1Mole, more preferably 10^-6Mol ~ 5 × 10^-2Is a mole.
[0101]
9) Combined use of multiple silver halides
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. As technologies related to these, JP-A-57-119341, 53-106125, 47-3929, 48-55730, 46-5187, 50-73627, 57-150841, etc. Can be mentioned. As the sensitivity difference, it is preferable that each emulsion has a difference of 0.2 logE or more.
[0102]
10) Application amount
The amount of photosensitive silver halide added is 1m of photosensitive material.²0.03 to 0.6 g / m²Preferably, 0.05 to 0.4 g / m²More preferably, 0.07 to 0.3 g / m²The photosensitive silver halide is preferably 0.01 mol or more and 0.5 mol or less, more preferably 0.02 mol or more and 0.3 mol or less, still more preferably 0.03 mol or more and 0.2 mol per 1 mol of the organic silver salt. It is as follows.
[0103]
11) Mixing of photosensitive silver halide and organic silver salt
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.
[0104]
12) Mixing silver halide into coating solution
The preferred addition time 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 of 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 delivered to the coater is the desired time, and by N. Harnby, MFEdwards, AWNienow, Takahashi There is a method of using a static mixer or the like described in Chapter 8 of the translation of Koji “Liquid Mixing Technology” (Nikkan Kogyo Shimbun, 1989).
[0105]
(Description of binder)
1) Binder type
Any polymer may be used as the binder of the organic silver salt-containing layer of the present invention, and suitable binders are transparent or translucent and generally colorless, and include natural resins, polymers and copolymers, synthetic resins, polymers and copolymers, etc. Film forming media such as gelatins, gums, poly (vinyl alcohol) s, hydroxyethyl celluloses, cellulose acetates, cellulose acetate butyrates, poly (vinyl pyrrolidone) s, casein, starch, poly (acrylic acid) ), Poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid), styrene-maleic anhydride copolymers, styrene-acrylonitrile copolymers, styrene-butadiene copolymers , Poly (vinyl acetal) s (eg, poly (vinyl Lumar) 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.
[0106]
2) Tg of binder
In the present invention, the glass transition temperature of the binder that can be used in combination with the layer containing the organic silver salt is preferably 0 ° C. or higher and 80 ° C. or lower (hereinafter sometimes referred to as a high Tg binder), and preferably 10 ° C. to 70 ° C. Is more preferable, and it is still more preferable that it is 15 degreeC or more and 60 degrees C or less.
[0107]
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 weight 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) (J. Brandrup, E.H. Immergut (Wiley-Interscience, 1989)).
[0108]
Two or more binders may be used in combination as required. Further, a glass transition temperature of 20 ° C. or higher and a glass transition temperature of less than 20 ° C. may be used in combination. When two or more kinds of polymers having different Tg are blended, the weight average Tg is preferably within the above range.
[0109]
3) Aqueous application
In the present invention, the organic silver salt-containing layer is preferably applied and dried using a coating solution in which 30% by mass or more of the solvent is water to form a film.
In the present invention, when the 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 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 purifying using a separation functional membrane after polymer synthesis.
[0110]
The aqueous solvent in which the polymer is soluble or dispersible here is a mixture of water or water with 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.
[0111]
“Equilibrium moisture content at 25 ° C. and 60% RH” means the weight W1 of the polymer in the humidity-controlled equilibrium under the atmosphere of 25 ° C. and 60% RH and the weight W0 of the polymer in the absolutely dry state at 25 ° C. It can be expressed as
Equilibrium moisture content at 25 ℃ 60% RH = [(W1-W0) / W0] x 100 (mass%)
[0112]
For the definition and measurement method of the moisture content, for example, Polymer Engineering Course 14, Polymer Material Testing Method (Edited by Polymer Society, Jinshokan) can be referred to.
[0113]
The equilibrium water content of the binder polymer of the present invention at 25 ° C. and 60% RH is preferably 2% by mass or less, more preferably 0.01% by mass or more and 1.5% by mass or less, and further preferably 0.02% by mass or more and 1% by mass or less. Is desirable.
[0114]
In the present invention, a polymer dispersible in an aqueous solvent is particularly preferred. Examples of the dispersed state may be either latex in which fine particles of a water-insoluble hydrophobic polymer are dispersed or polymer molecules dispersed in a molecular state or a micelle form. preferable. The average particle size of the dispersed particles is 1 to 50000 nm, preferably 5 to 1000 nm, more preferably 10 to 500 nm, and still more preferably 50 to 200 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. Mixing two or more types having a monodispersed particle size distribution is also a preferable method for controlling the physical properties of the coating solution.
[0115]
In the present invention, preferred embodiments of the polymer that can be dispersed in an aqueous solvent include acrylic polymers, poly (esters), rubbers (eg, SBR resin), poly (urethanes), poly (vinyl chloride) s, poly (acetic acid). Hydrophobic polymers such as vinyl), poly (vinylidene chloride) and poly (olefin) can be preferably used. These polymers may be linear polymers, branched polymers, crosslinked polymers, so-called homopolymers obtained by polymerizing a single monomer, or copolymers obtained by polymerizing two or more types of monomers. In the case of a copolymer, it may be a random copolymer or a block copolymer. The molecular weight of these polymers is 5,000 to 100,000, preferably 10,000 to 200,000 in number average molecular weight. When the molecular weight is too small, the mechanical strength of the image forming layer is insufficient, and when the molecular weight is too large, the film formability is poor, which is not preferable. A crosslinkable polymer latex is particularly preferably used.
[0116]
4) Specific examples of latex
Specific examples of preferable polymer latex include the following. Below, it represents using a raw material monomer, the numerical value in a parenthesis is 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 crosslinkability, and the description of molecular weight was omitted. Tg represents the glass transition temperature.
[0117]
Latex of P-1; -MMA (70) -EA (27) -MAA (3)-(molecular weight 37000, Tg61 ℃)
Latex of P-2; -MMA (70) -2EHA (20) -St (5) -AA (5)-(molecular weight 40000, Tg59 ° C)
Latex of P-3; -St (50) -Bu (47) -MAA (3)-(crosslinkability, Tg-17 ° C)
Latex of P-4; -St (68) -Bu (29) -AA (3)-(crosslinkability, Tg17 ° C)
Latex of P-5; -St (71) -Bu (26) -AA (3)-(crosslinkability, Tg24 ℃)
Latex of P-6; -St (70) -Bu (27) -IA (3)-(crosslinkability)
Latex of P-7; -St (75) -Bu (24) -AA (1)-(crosslinkability, Tg29 ° C)
Latex of P-8; -St (60) -Bu (35) -DVB (3) -MAA (2)-(crosslinkability)
P-9; -St (70) -Bu (25) -DVB (2) -AA (3)-latex (crosslinkable)
Latex of P-10; -VC (50) -MMA (20) -EA (20) -AN (5) -AA (5)-(molecular weight 80000)
P-11; -VDC (85) -MMA (5) -EA (5) -MAA (5)-latex (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, Tg43 ℃)
P-14; -MMA (63) -EA (35)-AA (2) latex (molecular weight 33000, Tg47 ℃)
Latex of P-15; -St (70.5) -Bu (26.5) -AA (3)-(crosslinkability, Tg23 ° C)
Latex of P-16; -St (69.5) -Bu (27.5) -AA (3)-(crosslinkability, Tg20.5 ℃)
[0118]
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; Vinylidene chloride, Et; ethylene, IA; itaconic acid.
[0119]
The polymer latex described above is also commercially available, and the following polymers can be used. Examples of acrylic polymers 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 polynet (urethanes) such as FINETEX ES650, 611, 675, 850 (Dainippon Ink Chemical Co., Ltd.), WD-size, WMS (Eastman Chemical). Are HYDRAN AP10, 20, 30, 40 (above Dainippon Ink Chemical Co., Ltd.) and examples of rubbers include LACSTAR 7310K, 3307B, 4700H, 7132C (above Dainippon Ink Chemical Co., Ltd.) , Nipol Lx416, 410, 438C, 2507 (made by Nippon Zeon Co., Ltd.) and other examples of poly (vinyl chloride) such as G351, G576 (made by Nippon Zeon Co., Ltd.), poly (vinylidene chloride) Examples of such products include L502, L513 (above Asahi Kasei Kogyo Co., Ltd.), and examples of poly (olefins) include Chemipearl S120, SA100 (above Mitsui Petrochemical ( And the like).
[0120]
These polymer latexes may be used alone or in combination of two or more as required.
[0121]
5) Preferred latex
The polymer latex used in the present invention is particularly preferably a styrene-butadiene copolymer latex. The weight 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. Moreover, it is preferable that the polymer latex of this invention contains 1-6 mass% of acrylic acid or methacrylic acid with respect to the sum of styrene and butadiene, More preferably, it contains 2-5 mass%. The polymer latex of the present invention preferably contains acrylic acid. The preferred molecular weight range is the same as described above.
[0122]
Examples of the latex of styrene-butadiene acid copolymer preferably used in the present invention include P-3 to P-8,15 described above, LACSTAR-3307B, 7132C, and Nipol Lx416, which are commercially available products.
[0123]
6) Preferred solvent for coating solution
In the present invention, the solvent of the organic silver salt-containing layer coating solution of the light-sensitive material (here, for simplicity, the solvent and the dispersion medium are collectively referred to as a solvent) is preferably an aqueous solvent containing 30% by mass or more of water. As a component other than water, any water-miscible organic solvent such as methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, and ethyl acetate may be used. The water content of the solvent of the coating solution is preferably 50% by mass or more, more preferably 70% by mass or more. Examples of preferred solvent compositions include water, water / methyl alcohol = 90/10, water / methyl alcohol = 70/30, water / methyl alcohol / dimethylformamide = 80/15/5, water / methyl alcohol / There are ethyl cellosolve = 85/10/5, water / methyl alcohol / isopropyl alcohol = 85/10/5, etc. (value is mass%).
[0124]
7) Other
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.
[0125]
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 binder in the organic silver salt-containing layer is such that the weight ratio of the total binder / organic silver salt is 1/110 to 10/1, more preferably 1/3 to 5/1, and even more preferably 1/1 to 3. The range is / 1.
[0126]
Further, such an organic silver salt-containing layer is usually a photosensitive layer (emulsion layer) containing a photosensitive silver halide which is a photosensitive silver salt. The weight ratio of silver is 400-5, more preferably 200-10.
[0127]
The total binder amount of the image forming layer of the present invention is preferably 0.2 to 30 g / m.², More preferably 1-15 g / m²More preferably 2-10 g / m²Range. The image forming layer of the present invention may contain a crosslinking agent for crosslinking, a surfactant for improving coating properties, and the like.
[0128]
(Description of antifogging agent)
Antifoggants, stabilizers and stabilizer precursors which can be used in the present invention are disclosed in paragraph No. 0070 of JP-A-10-62899, page 20 line 57 to page 21 line 7 of EP 080364A1. And the compounds described in JP-A-9-281637 and 9-329864, US Pat. Nos. 6,083,681, 6,083,681, and EP 1048975. Antifoggants preferably used in the present invention are organic halides, 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 JP-A-2000-284399, an organic polyhalogen compound represented by formula (II) in JP-A-10-339934, JP-A-2001-31644, and JP-A-2001-31644 The organic polyhalogen compounds described in 2001-33911 are preferred.
[0129]
1) Polyhalogen compounds
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 (H).
General formula (H)
Q- (Y) n-C (Z₁) (Z₂) X
In the general formula (H), 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.
In general formula (H), Q is preferably an aryl group or a heterocyclic group.
In the general formula (H), when Q is a heterocyclic group, a nitrogen-containing heterocyclic group containing 1 to 2 nitrogen atoms is preferable, and a 2-pyridyl group and a 2-quinolyl group are particularly preferable.
In the general formula (H), when Q is an aryl group, Q preferably represents a phenyl group substituted with an electron-withdrawing group in which Hammett's substituent constant σp takes a positive value. Regarding the Hammett's substituent constant, 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.
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.
[0130]
Specific examples of the compound of the general formula (H) of the present invention are shown below.
[0131]
Embedded image
[0132]
Other preferred polyhalogen compounds of the invention include those described in JP-A Nos. 2001-31644, 2001-56526, and 2001-209145.
The compound represented by the general formula (H) of the present invention is 10 per mole 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 ~ 0.5 mol, more preferably 1 × 10^-2It is preferable to use in the range of ~ 0.2 mol.
In the present invention, the antifoggant is added to the light-sensitive material by the method described in the method for containing a reducing agent, and the organic polyhalogen compound is also preferably added as a solid fine particle dispersion.
[0133]
2) Other antifogging agents
Examples of other antifoggants include mercury (II) salts described in JP-A No. 11-65021, paragraph No. 0113, benzoic acids listed in paragraph No. 0114, salicylic acid derivatives of JP-A No. 2000-206642, and formulas of JP-A No. 2000-221634. A formalin scavenger compound represented by (S), a triazine compound according to claim 9 of JP-A-11-352624, a compound represented by formula (III) of JP-A-61-11791, 4-hydroxy-6- And methyl-1,3,3a, 7-tetrazaindene.
[0134]
The photothermographic material in the invention may contain an azolium salt for the purpose of fog prevention. Examples of the azolium salt include compounds represented by general formula (XI) described in JP-A-59-193447, compounds described in JP-B-55-12581, and general formula (II) described in JP-A-60-153039. And the compounds represented. The azolium salt may be added to any part of the 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 powder, solution, fine particle dispersion. Moreover, you may add as a solution mixed with other additives, such as a sensitizing dye, a reducing agent, and a color toning agent. In the present invention, the addition amount of the azolium salt may be any amount, but is 1 × 10 10 per mole of silver.^-6Moles to 2 moles, preferably 1 × 10^-3More preferably, it is more than mol and less than 0.5 mol.
[0135]
(Other additives)
1) Mercapto, disulfide, and thiones
In the present invention, a mercapto compound, a disulfide compound, and a thione compound can be contained in order to suppress or promote development to control development, to improve spectral sensitization efficiency, and to improve storage stability before and after development. JP-A-10-62899, paragraphs 0067 to 0069, JP-A-10-186572, the compound represented by the general formula (I) and specific examples thereof, paragraphs 0033 to 0052, and EP 080364A1. 20 pages, lines 36-56. Of these, mercapto-substituted heteroaromatic compounds described in JP-A-9-297367, JP-A-9-304875, JP-A-2001-100358, Japanese Patent Application 2001-104213, Japanese Patent Application 2001-104214, and the like are preferable.
[0136]
2) Color preparation
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-10-62899, page 21 lines 23 to 48 of European Patent Publication No. 0803684A1, No. 2000-356317 and JP-A 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; eg 4- (1-naphthyl) phthalazine, 6-isopropyl (Thalazine, 6-t-butyl phthalazine, 6-chlorophthalazine, 5,7-dimethoxyphthalazine and 2,3-dihydrophthalazine); a combination of phthalazines and phthalic acids is preferred, especially phthalazines and phthalic acids The combination of is preferable. Of these, a particularly preferred combination is a combination of 6-isopropylphthalazine and phthalic acid or 4-methylphthalic acid.
[0137]
3) Plasticizer, lubricant
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 ultrahigh contrast agent for ultrahigh contrast image formation, and the addition method and amount thereof are the same. Paragraph No. 0118, Japanese Patent Application Laid-Open No. 11-223898, Paragraph Nos. 0136 to 0193, Japanese Patent Application Laid-Open No. 2000-284399, compounds of Formula (H), Formulas (1) to (3), Formulas (A) and (B), and Japanese Patent Application JP-A-11-65021, paragraph No. 0102, JP-A-11-65021, compounds of general formulas (III) to (V) described in JP-A-11-91652 (specific compounds: Chemical formulas 21 to 24), No. 223898, paragraph numbers 0194 to 0195.
[0138]
4) Dyes and pigments
Various dyes and pigments (for example, CIPigment Blue 60, CIPigment Blue 64, and CIPigment Blue 15: 6) are used for the photosensitive layer of the present invention from the viewpoints of improving color tone, preventing interference fringes during laser exposure, and preventing irradiation. Can be used. These are described in detail in WO98 / 36322, JP-A-10-268465, JP-A-11-338098 and the like.
[0139]
5) Ultra-high contrast agent
In order to form an ultrahigh contrast image suitable for printing plate making applications, it is preferable to add an ultrahigh contrast agent to the image forming layer. As for the ultra-high contrast agent and its addition method and addition amount, the formula (H) and the formula in paragraph No. 0118 of the same publication, paragraph Nos. 0136 to 0193 of JP-A No. 11-223898, and the specification of Japanese Patent Application No. 11-87297 (1) to (3), compounds of formulas (A) and (B), compounds of general formulas (III) to (V) described in Japanese Patent Application No. 11-91652 (specific compounds: embedded image 24), the contrast enhancement accelerator is described in paragraph No. 0102 of JP-A No. 11-65021 and paragraph Nos. 0194 to 0195 of JP-A No. 11-223898.
[0140]
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.
[0141]
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, and ammonium hexametaphosphate.
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 0.1 to 500 mg / m²Is preferred, 0.5-100 mg / m²Is more preferable.
The reducing agent, hydrogen bonding compound, development accelerator and polyhalogen compound of the present invention are preferably used as solid dispersions, and a preferred method for producing these solid dispersions is described in JP-A-2002-55405. .
[0142]
(Preparation and application of coating solution)
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. Further, it is preferable that the temperature of the image forming layer coating solution immediately after the addition of the polymer latex is maintained at 30 ° C. or more and 65 ° C. or less.
[0143]
(Layer structure and components)
The image forming layer of the present invention is composed of one or more layers on a support. In the case of a single 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 toning agents, coating aids and other auxiliary agents. In the case of two or more layers, the first image forming layer (usually the layer adjacent to the support) contains an organic silver salt and a light-sensitive silver halide, and some of the second image forming layer or both layers include Must contain other ingredients. The construction of a multicolor photosensitive photothermographic material may include a combination of these two layers for each color and includes all components in a single layer as described in US Pat. No. 4,708,928. Also good. In the case of a multi-dye multicolor photosensitive photothermographic material, each emulsion layer generally has a functional or non-functional barrier layer between each photosensitive layer as described in U.S. Pat.No. 4,460,681. By using, they are kept distinguished from each other.
The photothermographic material of the present invention can have a non-photosensitive layer in addition to the image forming layer. The non-photosensitive layer consists of (a) a surface protective layer provided on the image forming layer (on the side farther from the support), (b) between the plurality of image forming layers, An intermediate layer provided between them, (c) an undercoat layer provided between the image forming layer and the support, and (d) a back layer provided on the opposite side of the image forming layer.
[0144]
In addition, although a layer acting as an optical filter can be provided, it is provided as the layer (a) or (b). The antihalation layer is provided on the photosensitive material as the layer (c) or (d).
[0145]
1) Surface protective layer
In the photothermographic material of the invention, a surface protective layer can be provided 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 JP-A 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), and 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- Preferred is 203 (trade name, manufactured by Kuraray Co., Ltd.). Polyvinyl alcohol coating amount of protective layer (per layer) (support 1m²As per) 0.3-4.0g / m²Is preferably 0.3 to 2.0 g / m²Is more preferable.
[0146]
Total binder (including water-soluble polymer and latex polymer) coating amount of surface protective layer (per layer) (support 1m²As per) 0.3-5.0g / m²Is preferably 0.3 to 2.0 g / m²Is more preferable.
[0147]
2) Antihalation layer
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.
[0148]
For the antihalation layer, paragraphs 0123 to 0124 of JP-A-11-65021, JP-A-11-223898, 9-230531, 10-36695, 10-104779, 11-231457, 11 -352625, 11-352626, etc.
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 and the like.
[0149]
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 0.15 to 2, and more preferably 0.2 to 1. The amount of dye used to obtain such an optical density is generally 0.001 to 1 g / m.²Degree.
[0150]
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 decoloration 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-11-352626). 4-Chlorophenyl (phenyl) sulfone), 2-naphthyl benzoate and the like are preferably used in view of thermal decoloring properties.
[0151]
3) Back layer
The back layer applicable to the present invention is described in paragraph numbers 0128 to 0130 of JP-A No. 11-65021.
[0152]
In the present invention, a colorant having an absorption maximum at 300 to 450 nm can be added for the purpose of improving silver tone and aging of the image. Such colorants are disclosed in JP-A Nos. 62-210458, 63-104046, 63-103235, 63-208846, 63-306436, 63-314535, and JP-A-01-61745. No. 1, JP-A-2001-100363 and the like. Such colorants are usually 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.
In order to adjust the base color tone, it is preferable to use a dye having an absorption peak at 580 to 680 nm. As the dye for this purpose, an azomethine oil-soluble dye described in JP-A-4-359967 and JP-A-4-359968 having a small absorption intensity on the short wavelength side, and a phthalocyanine water-soluble dye described in Japanese Patent Application No. 2002-96797 are preferable. The dye for this purpose may be added to any layer, but is more preferably added to the non-photosensitive layer on the emulsion surface side or the back surface side.
[0153]
The photothermographic material of the present invention is a so-called single-sided photosensitive material having a photosensitive layer containing at least one silver halide emulsion on one side of the support and a back layer on the other side. preferable.
[0154]
4) Matting agent
In the present invention, it is preferable to add a matting agent for improving transportability, and the matting agent is described in paragraph Nos. 0126 to 0127 of JP-A No. 11-65021. Matting agent is photosensitive material 1m²When expressed in terms of coating amount per unit, preferably 1 to 400 mg / m², More preferably 5 to 300 mg / m²It is.
In the present invention, the shape of the matting agent may be either a regular shape or an irregular shape, but is preferably a regular shape, and a spherical shape is preferably used. The average particle size is preferably 0.5 to 10 μm, more preferably 1.0 to 8.0 μm, and still more preferably 2.0 to 6.0 μm. The variation coefficient of the size distribution is preferably 50% or less, more preferably 40% or less, and still more preferably 30% or less. Here, the coefficient of variation is a value represented by (standard deviation of particle size) / (average value of particle size) × 100. It is also preferable to use two types of matting agents having a small variation coefficient and having an average particle size ratio larger than 3.
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, 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.
[0155]
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, more preferably 500 seconds or less and 40 seconds or more.
[0156]
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.
[0157]
5) Polymer latex
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 (1978))”, “Application of synthetic latex (Takaaki Sugimura, Ikuo Kataoka, Junichi Suzuki, Keiji Kasahara, Takashi Published in Molecular Publications (1993)) and “Synthetic Latex Chemistry (Muroichi Muroi, Published by High Polymers Publication (1970))”, specifically, methyl methacrylate (33.5% by mass) / ethyl Latex of acrylate (50% by weight) / methacrylic acid (16.5% by weight) copolymer, latex of methyl methacrylate (47.5% by weight) / butadiene (47.5% by weight) / itaconic acid (5% by weight) copolymer, ethyl acrylate / methacrylic acid Copolymer latex, methyl methacrylate (58.9% by mass) / 2-ethylhexyl acrylate (25.4% by mass) / styrene (8.6% by mass) / 2-hydro Latex of methyl methacrylate (5.1 mass%) / acrylic acid (2.0 mass%) copolymer, 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 and the like. Further, as a binder for the surface protective layer, a combination of polymer latex described in Japanese Patent Application No. 11-6872 and the technique described in Paragraph Nos. 0021 to 0025 of Japanese Patent Application Laid-Open No. 2000-267226, Japanese Patent Application No. 11-6872 The technology described in paragraph numbers 0027 to 0028 of the specification and the technology described in paragraph numbers 0023 to 0041 of JP 2000-19678 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.
[0158]
6) Membrane pH
The photothermographic material of the present invention preferably has a film surface pH of 7.0 or less, more preferably 6.6 or less before heat development. The lower limit is not particularly limited, but is about 3. The most preferred pH range is in the range of 4 to 6.2. The film surface pH is preferably adjusted using an organic acid such as a phthalic acid derivative, a non-volatile acid such as sulfuric acid, or a volatile base such as ammonia from the viewpoint of reducing the film surface pH. In particular, ammonia is volatile and is preferable for achieving a low film surface pH because it can be removed before the coating process or heat development.
In addition, it is also preferable to use ammonia in combination with a nonvolatile base such as sodium hydroxide, potassium hydroxide, or lithium hydroxide. A method for measuring the film surface pH is described in paragraph No. 0123 of JP-A-2000-284399.
[0159]
7) Hardener
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 are THJames' “THE THEORY OF THE PHOTOGRAPHIC PROCESS FOURTH EDITION” (Macmillan Publishing Co., Inc., published in 1977), each of the methods described on pages 77 to 87. , 4-Dichloro-6-hydroxy-s-triazine sodium salt, N, N-ethylenebis (vinylsulfoneacetamide), N, N-propylenebis (vinylsulfoneacetamide) and polyvalent metals described on page 78 Ions, polyisocyanates such as US Pat. No. 4,281,060 and 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.
[0160]
The hardener 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 delivered to the coater is the desired time, and by N. Harnby, MFEdwards, AWNienow, Takahashi There is a method of using a static mixer or the like described in Chapter 8 of the translation of Koji “Liquid Mixing Technology” (Nikkan Kogyo Shimbun, 1989).
[0161]
8) Surfactant
JP-A-11-65021 paragraph number 0132 for surfactants applicable to the present invention, paragraph number 0133 for solvents, paragraph number 0134 for supports, paragraph number for antistatic or conductive layers The method for obtaining a color image is described in paragraph No. 0136 of the same publication, and the slip agent is described in paragraph Nos. 0061 to 0064 of JP-A No. 11-84573 and paragraph Nos. 0049 to 0062 of Japanese Patent Application No. 11-106881.
In the present invention, it is preferable to use a fluorosurfactant. Specific examples of the fluorosurfactant include compounds described in JP-A-10-197985, JP-A-2000-19680, JP-A-2000-214554, and the like. In addition, polymeric fluorine-based surfactants described in JP-A-9-281636 are also preferably used. In the photothermographic material of the present invention, it is preferable to use a fluorosurfactant described in JP-A No. 2002-82411, Japanese Patent Application Nos. 2001-242357 and 2001-264110. In particular, the fluorosurfactants described in Japanese Patent Application Nos. 2001-242357 and 2001-264110 are preferable in terms of charge adjustment ability, stability of the coated surface, and smoothness when coating and manufacturing with an aqueous coating solution. The fluorine-based surfactant described in Japanese Patent Application No. 2001-264110 is most preferable in that it has a high charge control capability and requires a small amount of use.
In the present invention, the fluorosurfactant can be used on either the emulsion surface or the back surface, and is preferably used on both surfaces. Further, it is particularly preferable to use in combination with a conductive layer containing the above-described metal oxide. In this case, sufficient performance can be obtained even if the amount of the fluorosurfactant used on the surface having the conductive layer is reduced or removed.
The preferred use amount of the fluorosurfactant is in the range of 0.1 mg / m2 to 100 mg / m2, more preferably in the range of 0.3 mg / m2 to 30 mg / m2, more preferably 1 mg / m2 to the emulsion surface and the back surface, respectively. It is in the range of 10 mg / m2. In particular, the fluorosurfactant described in Japanese Patent Application No. 2001-264110 is highly effective, preferably in the range of 0.01 to 10 mg / m2, and more preferably in the range of 0.1 to 5 mg / m2.
[0162]
9) Antistatic agent
In the present invention, it is preferable to have a conductive layer containing a metal oxide or a conductive polymer. The antistatic layer may serve as an undercoat layer, a back layer surface protective layer, or the like, or may be provided separately. As the conductive material for the antistatic layer, a metal oxide in which conductivity is improved by introducing oxygen defects or different metal atoms into the metal oxide is preferably used. Examples of metal oxides are ZnO, TiO₂, SnO₂And for ZnO, addition of Al and In, SnO₂For Sb, Nb, P, halogen elements, etc., TiO₂In contrast, addition of Nb, Ta or the like is preferable. Especially SnO with Sb added₂Is preferred. The amount of different atoms added is preferably in the range of 0.01 to 30 mol%, more preferably in the range of 0.1 to 10 mol%. The shape of the metal oxide may be spherical, needle-like, or plate-like, but needle-like particles having a long axis / uniaxial ratio of 2.0 or more, preferably 3.0 to 50 are preferable from the viewpoint of providing conductivity. The amount of metal oxide used is preferably 1 mg / m²~ 1000mg / m²In the range, more preferably 10 mg / m²~ 500mg / m²Range, more preferably 20 mg / m²~ 200mg / m²Range. The antistatic layer of the present invention may be disposed on either the emulsion surface side or the back surface side, but is preferably disposed between the support and the back layer. Specific examples of the antistatic layer of the present invention include paragraph No. 0135 of JP-A-11-65021, JP-A-56-143430, JP-A-56-143431, JP-A-58-62646, JP-A-56-120519, JP-A-11- No. 84573, paragraph numbers 0040 to 0051, US Pat. No. 5,575,957, and JP-A No. 11-223898, paragraph numbers 0078 to 0084.
[0163]
10) Support
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. Examples of the support include water-soluble polyesters disclosed in JP-A-11-84574, styrene-butadiene copolymers described in JP-A-10-186565, and vinylidene chloride described in JP-A-2000-39684 and JP-A-11-106881, paragraphs 0063 to 0080. It is preferable to apply an undercoating technique such as a copolymer.
[0164]
11) Other additives
An antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, or a coating aid may be further added to the photothermographic material. Various additives are added to either the photosensitive layer or the non-photosensitive layer. For these, reference can be made to WO98 / 36322, EP803764A1, JP-A-10-186567, 10-18568 and the like.
[0165]
12) Application method
The photothermographic material in the invention may be applied by any method. Specifically, various coating operations are used, including extrusion coating, slide coating, curtain coating, dip coating, knife coating, flow coating, or extrusion coating using a hopper of the type described in U.S. Pat. Stephen F. Kistler and Petert M. Schweizer “LIQUID FILM COATING” (CHAPMAN & HALL, 1997) pages 399 to 536, preferably used for extrusion coating or slide coating, particularly preferably for slide coating It is done. An example of the shape of the slide coater used for slide coating is shown in Figure 11b.1 on page 427 of the same book. If desired, two or more layers can be simultaneously coated by the method described in pages 399 to 536 of the same document, the method described in US Pat. No. 2,761,791 and British Patent No. 837,095. Particularly preferred coating methods in the present invention are those described in JP-A Nos. 2001-194748, 2002-153808, 2002-153803, and 2002-182333.
[0166]
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 1 mPa · s or more and 200 mPa · s or less, and more preferably 5 mPa · s or more and 80 mPa · s or less.
[0167]
In the case of preparing the coating liquid of the present invention, a known in-line mixer or implant mixer is preferably used when mixing two kinds of liquids. A preferred in-line mixer of the present invention is described in JP-A-2002-85948, and an implant mixer is described in JP-A-2002-90940.
The coating solution in the present invention is preferably subjected to defoaming treatment in order to keep the coated surface state good. A preferred defoaming treatment method of the present invention is the method described in JP-A-2002-66431.
When applying the coating solution of the present invention, it is preferable to perform static elimination in order to prevent adhesion of dust, dust, and the like due to electric resistance of the support. An example of a preferable static elimination method in the present invention is described in JP-A-2002-143747.
In the present invention, it is important to precisely control the drying air and the drying temperature in order to dry the non-setting image forming layer coating solution. The preferred drying method of the present invention is described in detail in JP-A Nos. 2001-194749 and 2002-139814.
The photothermographic material of the present invention is preferably subjected to a heat treatment immediately after coating and drying in order to improve film formability. The temperature of the heat treatment is preferably in the range of 60 ° C. to 100 ° C. as the film surface temperature, and the heating time is preferably in the range of 1 second to 60 seconds. A more preferable range is a film surface temperature of 70 to 90 ° C. and a heating time of 2 to 10 seconds. A preferred heat treatment method of the present invention is described in JP-A No. 2002-107872.
In order to stably and continuously produce the photothermographic material of the present invention, the production methods described in JP-A Nos. 2002-156728 and 2002-182333 are preferably used.
[0168]
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).
[0169]
13) Packaging materials
The light-sensitive material of the present invention is preferably packaged with a packaging material having a low oxygen permeability and / or moisture permeability in order to suppress fluctuations in photographic performance during raw storage or to improve curling, curling, etc. Oxygen permeability is 50ml / atm ・ m at 25 ℃²・ It is preferably less than day, more preferably 10 ml / atm · m²・ Day or less, more preferably 1.0ml / atm ・ m²・ It is less than day. Moisture permeability is 10g / atm · m²・ It is preferably less than day, more preferably 5g / atm · m²・ Day or less, more preferably 1g / atm ・ m²・ It is less than day.
Specific examples of the packaging material having a low oxygen permeability and / or moisture permeability are disclosed in, for example, JP-A-8-254793. This is a packaging material described in JP-A-2000-206653.
[0170]
14) Other available technologies
Techniques that can be used for the photothermographic material of the present invention include EP803764A1, EP883022A1, WO98 / 36322, JP 56-62648, 58-62644, JP 9-43766, and 9- 281637, 9-297367, 9-304869, 9-311405, 9-329865, 10-10669, 10-62899, 10-69023, 10-186568, 10-90823, 10-171063, 10-186565, 10-186567, 10-186569 to 10-186572, 10-197974, 10-197982, 10 -197983, 10-197985 to 10-197987, 10-207001, 10-207004, 10-221807, 10-282601, 10-288823, 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 to 11-133539, 11-133542, 11 -133543, 11-223898, 11-352627, 11-305377, 11-305378, 11-305384, 11-305380, 11-316435, 11-327076, 11-338096, 11-338098, 11-338099, 11- 343420, JP 2000-187298, 2000-10229, 2000-47345, 2000-206642, 2000-98530, 2000-98531, 2000-112059, 2000-112060 No., 2000-112104, 2000-112064, 2000-171936.
[0171]
In the case of a multicolor color photothermographic material, each emulsion layer generally uses a functional or non-functional barrier layer between each photosensitive layer, as described in US Pat. No. 4,460,681. Thus, they are kept distinguished from each other.
The construction in the case of a multicolor color photothermographic material may include a combination of these two layers for each color, and includes all components in a single layer as described in US Pat. No. 4,708,928. May be.
[0172]
(Image forming method)
1) Exposure
Red to infrared emitting He-Ne laser, red semiconductor laser, or blue to green emitting Ar⁺, He—Ne, He—Cd laser, blue semiconductor laser. Preferred is a red to infrared semiconductor laser, and the peak wavelength of the laser light is 600 nm to 900 nm, preferably 620 nm to 850 nm. On the other hand, in particular, in particular, a module in which an SHG (Second Harmonic Generator) element and a semiconductor laser are integrated and a blue semiconductor laser have been developed, and a laser output device in a short wavelength region has been closed up. The blue semiconductor laser is expected to increase in demand in the future because high-definition image recording is possible, the recording density is increased, and a stable output is obtained with a long lifetime. The peak wavelength of the blue laser light is preferably 300 nm to 500 nm, particularly preferably 400 nm to 500 nm.
It is also preferable that the laser light is oscillated in a vertical multi by a method such as high frequency superposition.
[0173]
2) Thermal development
The photothermographic material of the present invention may be developed by any method, but is usually developed by raising the temperature of the photothermographic material exposed imagewise. A preferred development temperature is 80 to 250 ° C, preferably 100 to 140 ° C, more preferably 110 to 130 ° C. The development time is preferably 1 to 60 seconds, more preferably 3 to 30 seconds, still more preferably 5 to 25 seconds, and 7 to 15 seconds.
[0174]
Either a drum type heater or a plate type heater may be used as the thermal development method, but the plate type heater method is more preferable. The plate-type heater-based heat development method is preferably the method described in JP-A-11-133572, and a visible image is obtained by bringing the heat-developable photosensitive material on which the latent image has been formed into contact with the heating means in the heat developing section. 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. For example, there are examples in which four sets of plate heaters that can be independently controlled are used and controlled so as to be 112 ° C., 119 ° C., 121 ° C., and 120 ° C., respectively. Such a method is also described in JP-A-54-30032, which can exclude moisture and organic solvents contained in the photothermographic material out of the system, and can be rapidly developed in the photothermographic material. It is also possible to suppress a change in the shape of the support of the photothermographic material due to the heating.
[0175]
In order to reduce the size of the heat developing machine and shorten the heat development time, it is preferable to be able to control the heater more stably. In addition, the exposure of one sheet of photosensitive material is started from the top and the exposure is finished to the rear end. It is desirable to start the heat development before the time. Imagers capable of rapid processing preferred in the present invention are described in, for example, Japanese Patent Application Nos. 2001-088832 and 091114. If this imager is used, for example, heat development can be performed in 14 seconds with a three-stage plate heater controlled at 107 ° C.-121 ° C.-121 ° C., and the output time of the first sheet is reduced to about 60 seconds. be able to. For such rapid development processing, it is preferable to use the photothermographic material-2 of the present invention in combination with high sensitivity and less susceptible to environmental temperature.
[0176]
3) System
An example of a medical laser imager provided with an exposure unit and a heat development unit is Fuji Medical Dry Laser Imager FM-DPL. FM-DP L is described in Fuji Medical Review No. 8, pages 39 to 55, and it goes without saying that those techniques are applied as a laser imager of the photothermographic material of the present invention. It can also be applied as a photothermographic material for a laser imager of the “AD network” proposed by Fuji Film Medical System Co., Ltd. as a network system adapted to the DICOM standard.
[0177]
(Use of the present invention)
The photothermographic material of the present invention forms a black and white image by a silver image, and is used as a photothermographic material for medical diagnosis, a photothermographic material for industrial photography, a photothermographic material for printing, and a photothermographic material for COM. It is preferably used.
[0178]
【Example】
EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.
(Basic composition of photothermographic material)
[0179]
(PET support creation)
Using terephthalic acid and ethylene glycol, PET having an intrinsic viscosity of IV = 0.66 (measured in phenol / tetrachloroethane = 6/4 (weight ratio) at 25 ° C.) was obtained according to a conventional method. This was pelletized, dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-type die, and rapidly cooled to prepare an unstretched film having a thickness of 175 μm after heat setting.
[0180]
This was longitudinally stretched 3.3 times using rolls with different peripheral speeds and then stretched 4.5 times with a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively. Thereafter, the film was heat-fixed at 240 ° C. for 20 seconds and relaxed by 4% in the lateral direction at the same temperature. After slitting the chuck part of the tenter, knurling is performed on both ends, and 4kg / cm²And a roll having a thickness of 175 μm was obtained.
[0181]
(Surface corona treatment)
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 / m²It 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.
[0182]
(Creation of undercoat support)
(1) Preparation of undercoat layer coating solution
[0183]
[0184]
[0185]
After both surfaces of the biaxially stretched polyethylene terephthalate support having a thickness of 175 μm are subjected to the corona discharge treatment, the undercoat coating liquid formulation {circle around (1)} is applied to one surface (photosensitive layer surface) with a wire bar at a wet coating amount of 6.6 ml / m²(Per side) and dry at 180 ° C. for 5 minutes, and then apply the undercoat coating solution formulation (2) on the back side (back side) with a wire bar at a wet coating amount of 5.7 ml / m.²And then dry at 180 ° C. for 5 minutes, and further apply the above undercoat coating liquid formulation (3) on the back surface (back surface) with a wire bar at a wet coating amount of 7.7 ml / m.²And then dried at 180 ° C. for 6 minutes to prepare an undercoat support.
[0186]
(Preparation of back surface coating solution)
(Preparation of solid fine particle dispersion (a) of base precursor)
Add 2.5 kg of base precursor compound 1, 300 g of surfactant (trade name: Demol N, manufactured by Kao Corporation), 800 g of diphenylsulfone, 1.0 g of benzoisothiazolinone sodium salt and distilled water, and add a total amount of 8.0 kg. The mixed solution was bead-dispersed using a horizontal sand mill (UVM-2: manufactured by IMEX Co., Ltd.). In the dispersion method, the mixed solution was fed to UVM-2 filled with zirconia beads having an average diameter of 0.5 mm with a diaphragm pump, and dispersed at an internal pressure of 50 hPa or more until a desired average particle size was obtained.
The dispersion was subjected to spectral absorption measurement, and the ratio of absorbance at 450 nm to absorbance at 650 nm (D450 / D650) in the spectral absorption of the dispersion was dispersed to 3.0. The obtained dispersion was diluted with distilled water so that the concentration of the base precursor was 25% by weight, and was filtered for removal of dust (filter made of polypropylene having an average pore size of 3 μm) for practical use.
[0187]
(Preparation of dye solid fine particle dispersion)
6.0 kg of cyanine dye compound-1 and 3.0 kg of sodium p-dodecylbenzenesulfonate, 0.6 kg of surfactant Demol SNB manufactured by Kao Corporation, and antifoaming agent (trade names: Surfynol 104E, Nisshin Chemical Co., Ltd.) (Manufactured) 0.15 kg was mixed with distilled water to make a total liquid volume of 60 kg. The mixed solution was dispersed with 0.5 mm zirconia beads using a horizontal sand mill (UVM-2: manufactured by Imex Corporation).
The dispersion was subjected to spectral absorption measurement and dispersed until the ratio of the absorbance at 650 nm to the absorbance at 750 nm (D650 / D750) in the spectral absorption of the dispersion was 5.0 or more. The obtained dispersion was diluted with distilled water so that the concentration of the cyanine dye was 6% by mass, and subjected to filter filtration (average pore diameter: 1 μm) for removing dust.
[0188]
(Preparation of antihalation layer coating solution)
The container was kept at 40 ° C., and gelatin was dissolved by adding 40 g of gelatin, 20 g of monodisperse polymethyl methacrylate fine particles (average particle size 8 μm, particle size standard deviation 0.4), 0.1 g of benzoisothiazolinone, and 490 ml of water. Further, 2.3 ml of 1 mol / l sodium hydroxide aqueous solution, 40 g of the above dye solid fine particle dispersion, 90 g of the solid fine particle dispersion (a) of the above base precursor, 12 ml of 3% aqueous solution of sodium polystyrenesulfonate, 180 g of SBR latex 10% , Were mixed. Immediately before coating, 80 ml of a 4% aqueous solution of N, N-ethylenebis (vinylsulfonacetamide) was mixed to prepare a coating solution for the antihalation layer.
[0189]
(Preparation of back surface protective layer coating solution)
The container was kept at 40 ° C. and gelatin was dissolved by adding 40 g of gelatin, 35 mg of benzoisothiazolinone and 840 ml of water. In addition, 5.8 ml of 1 mol / l sodium hydroxide aqueous solution, 1.5 g of liquid paraffin emulsion as liquid paraffin, 10 ml of 5% aqueous solution of di (2-ethylhexyl) sodium sulfosuccinate, 20 ml of 3% aqueous solution of sodium polystyrene sulfonate, fluorine-based interface 2.4 ml of 2% solution of activator (F-1), 2.4 ml of 2% solution of fluorosurfactant (F-2), methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer) Polymerization weight ratio 57/8/28/5/2) 32 g of 19% by weight latex was mixed. Immediately before coating, 25 ml of a 4% aqueous solution of N, N-ethylenebis (vinylsulfonacetamide) was mixed to prepare a coating solution for the back surface protective layer.
[0190]
(Preparation of silver halide emulsion)
<< Preparation of silver halide emulsion 1 >>
Add 3 ml of 1% by weight potassium bromide solution to 1421 ml of distilled water, and then add 3.5 ml of 0.5 mol / L sulfuric acid and 31.7 g of phthalated gelatin while stirring in a stainless steel reaction vessel at 30 ° C. Maintaining the liquid temperature, the solution A diluted with 22.22 g of silver nitrate with distilled water diluted to 95.4 ml, and the solution B diluted with potassium bromide 15.3 g and potassium iodide 0.8 g with distilled water to a volume of 97.4 ml at a constant flow rate The whole amount was added over 45 seconds. Thereafter, 10 ml of a 3.5 mass% aqueous hydrogen peroxide solution was added, and 10.8 ml of a 10 mass% aqueous solution of benzimidazole was further added. Further, Solution C obtained by adding distilled water to 517.56 g of silver nitrate and diluted to 317.5 ml, Solution D obtained by diluting 44.2 g of potassium bromide and 2.2 g of potassium iodide to a capacity of 400 ml with distilled water, and Solution C at a constant flow rate. The entire amount was added over 20 minutes, and Solution D was added by the controlled double jet method while maintaining pAg at 8.1.
[0191]
1 x 10 per mole of silver^-FourThe total amount of iridium (III) hexachloride potassium salt was added to a molar ratio 10 minutes after the start of addition of Solution C and Solution D. Further, 5 seconds after the completion of the addition of the solution C, an aqueous solution of potassium iron (II) hexacyanide was added at 3 × 10 3 per mol of silver.^-FourThe whole molar amount was added. The pH was adjusted to 3.8 using 0.5 mol / L sulfuric acid, stirring was stopped, and precipitation / desalting / water washing steps were performed. The pH was adjusted to 5.9 with 1 mol / L sodium hydroxide to prepare a silver halide dispersion having a pAg of 8.0.
[0192]
The silver halide dispersion was maintained at 38 ° C. with stirring, 5 ml of a 0.34 mass% 1,2-benzoisothiazolin-3-one methanol solution was added, and the temperature was raised to 47 ° C. after 40 minutes. After 20 minutes of temperature increase, sodium benzenethiosulfonate in methanol solution was 7.6 x 10 for 1 mol of silver.^-Five5 minutes later, tellurium sensitizer C was added with methanol solution to give 2.9 x 10 per mole of silver.^-FourMole was added and aged for 91 minutes. Thereafter, a methanol solution having a molar ratio of the spectral sensitizing dye A and the sensitizing dye B of 3: 1 is 1.2 × 10 6 as the sum of the sensitizing dyes A and B per mole of silver.^-3After 1 minute, 1.3 ml of a 0.8% by weight methanol solution of N, N'-dihydroxy-N "-diethylmelamine was added. After another 4 minutes, 5-methyl-2-mercaptobenzimidazole was added with 1 mole of silver in a methanol solution. 4.8 × 10^-3Mole, 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole in methanol solution to 5.4 × 10^-3Mole and 1- (3-Methylureido) -5-mercaptotetrazole sodium salt in aqueous solution 8.5 × 10 5 per mole of silver^-3A silver halide emulsion 1 was prepared by adding a molar amount.
[0193]
Grains in the prepared silver halide emulsion were silver iodobromide grains containing 3.5 mol% of iodine with an average sphere equivalent diameter of 0.042 μm and a sphere equivalent diameter variation coefficient of 20%. The particle size and the like were determined from an average of 1000 particles using an electron microscope. The [100] face ratio of the particles was determined to be 80% using the Kubelka-Munk method.
[0194]
<< Preparation of silver halide emulsion 2 >>
In the preparation of silver halide emulsion 1, the solution temperature at the time of grain formation was changed from 30 ° C. to 47 ° C., and solution B was changed to diluting 15.9 g of potassium bromide with distilled water to a volume of 97.4 ml. Was changed to dilute 45.8 g of potassium bromide with distilled water to a volume of 400 ml, the addition time of solution C was changed to 30 minutes, and potassium hexacyanoferrate (II) was removed in the same manner. Silver emulsion 2 was prepared. Precipitation / desalting / washing / dispersion was carried out in the same manner as silver halide emulsion 1. Furthermore, the amount of tellurium sensitizer C added was 1.1 × 10 6 per silver mole.^-FourMole, the addition amount of a 3: 1 methanol solution in the molar ratio of spectral sensitizing dye A and spectral sensitizing dye B is 7.0 × 10 as the total of sensitizing dye A and sensitizing dye B per mole of silver.^-FourMole, 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole, 3.3 × 10 3 moles per mole of silver^-3Mole and 1- (3-Methylureido) -5-mercaptotetrazole sodium salt is 4.7 × 10 4 per mol of silver.^-3Spectral sensitization, chemical sensitization, and 5-methyl-2-mercaptobenzimidazole, 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole as in Emulsion 1 except that the molar addition was changed Was added to obtain a silver halide emulsion 2. The emulsion grains of the silver halide emulsion 2 were pure silver bromide cubic grains having an average sphere equivalent diameter of 0.080 μm and a sphere equivalent diameter variation coefficient of 20%.
[0195]
<< Preparation of silver halide emulsion 3 >>
In the preparation of silver halide emulsion 1, silver halide emulsion 3 was prepared in the same manner except that the liquid temperature at the time of grain formation was changed from 30 ° C. to 27 ° C. Further, precipitation / desalting / washing / dispersion was performed in the same manner as silver halide emulsion 1. The molar ratio of spectral sensitizing dye A and spectral sensitizing dye B is 1: 1 as a solid dispersion (gelatin aqueous solution), and the addition amount is 6 × 10 6 as the total of sensitizing dye A and sensitizing dye B per mole of silver.^-3Mol, tellurium sensitizer C added to 5.2 x 10 per mole of silver^-Four3 minutes after adding the tellurium sensitizer, 5 × 10^-FourMoles and potassium thiocyanate 2 x 10 per mole of silver^-3A silver halide emulsion 3 was obtained in the same manner as Emulsion 1 except that a mole was added. Emulsion grains of the silver halide emulsion 3 were silver iodobromide grains containing 3.5 mol% of iodine having an average equivalent sphere diameter of 0.034 μm and a variation coefficient of 20% of the equivalent sphere diameter.
[0196]
<Preparation of mixed emulsion A for coating solution>
70% by weight of silver halide emulsion 1, 15% by weight of silver halide emulsion 2 and 15% by weight of silver halide emulsion 3 are dissolved in a 1% by weight aqueous solution of benzothiazolium iodide. × 10^-3Mole was added. Further, water is added so that the silver halide content per kg of the mixed emulsion for coating solution is 38.2 g as silver, and 1- (3-methylureido) -5--5 is obtained so that the amount is 0.34 g per kg of the mixed emulsion for coating solution. Mercaptotetrazole sodium salt was added.
[0197]
<< Preparation of fatty acid silver dispersion A >>
Henkel behenic acid (product name Edenor C22-85R) 87.6 kg, distilled water 423 L, 5 mol / L NaOH aqueous solution 49.2 L, t-butyl alcohol 120 L are mixed, stirred at 75 ° C. for 1 hour, reacted. Sodium behenate solution A was obtained. Separately, 206.2 L (pH 4.0) of an aqueous solution of 40.4 kg of silver nitrate was prepared and kept warm at 10 ° C. Keep the reaction vessel containing 635L of distilled water and 30L of t-butyl alcohol at 30 ° C, and with sufficient agitation, the total amount of the previous sodium behenate solution A and the total amount of silver nitrate aqueous solution is 93 minutes each at a constant flow rate. Added over seconds and 90 minutes. At this time, only the silver nitrate aqueous solution is added for 11 minutes after the start of the addition of the silver nitrate aqueous solution, and then the addition of the sodium behenate solution A is started, and after the addition of the silver nitrate aqueous solution, only the sodium behenate solution A is added for 14 minutes and 15 seconds. Was added. At this time, the temperature in the reaction vessel was 30 ° C., and the external temperature was controlled so that the liquid temperature was constant. The piping of the addition system for the sodium behenate solution A was prepared by circulating warm water outside the double tube so that the liquid temperature at the outlet of the addition nozzle tip was 75 ° C. Moreover, the piping of the addition system of the silver nitrate aqueous solution was kept warm by circulating cold water outside the double pipe. The addition position of the sodium behenate solution A and the addition position of the silver nitrate aqueous solution were symmetrically arranged around the stirring axis, and were adjusted so as not to contact the reaction solution.
[0198]
After completion of the addition of the sodium behenate solution A, the mixture was left stirring for 20 minutes at the same temperature, heated to 35 ° C. over 30 minutes, and then aged for 210 minutes. Immediately after completion of aging, the solid content was separated by centrifugal filtration, and the solid content was washed with water until the conductivity of filtered water reached 30 μS / cm. Thus, a fatty acid silver salt was obtained. The obtained solid content was stored as a wet cake without drying.
[0199]
When the morphology of the obtained silver behenate particles was evaluated by electron micrograph, the average value was a = 0.14 μm, b = 0.4 μm, c = 0.6 μm, average aspect ratio 5.2, average sphere equivalent diameter 0.52 μm, sphere equivalent It was a flake-like crystal with a diameter variation coefficient of 15%. (A, b, and c are the provisions of the text)
[0200]
Add 19.3 kg of polyvinyl alcohol (trade name: PVA-217) and water to a wet cake with a dry solid content of 260 kg, make the total amount 1000 kg, and then slurry with a dissolver blade. Pipeline mixer (manufactured by Mizuho Kogyo Co., Ltd .: PM-10 type).
[0201]
Next, the pre-dispersed stock solution is subjected to a disperser (trade name: Microfluidizer M-610, manufactured by Microfluidics International Corporation, using a Z-type interaction chamber) at a pressure of 1260 kg / cm²And was treated three times to obtain a silver behenate dispersion. The cooling operation was set to a dispersion temperature of 18 ° C. by installing a serpentine heat exchanger before and after the interaction chamber and adjusting the temperature of the refrigerant.
[0202]
<< Preparation of fatty acid silver dispersion B >>
<Preparation of recrystallized behenic acid>
100 kg of behenic acid (product name Edenor C22-85R) manufactured by Henkel was mixed in 1200 kg of isopropyl alcohol, dissolved at 50 ° C., filtered through a 10 μm filter, cooled to 30 ° C., and recrystallized. The cooling speed during recrystallization was controlled at 3 ° C / hour. The obtained crystals were centrifugally filtered, washed with 100 kg of isopropyl alcohol, and then dried. When the obtained crystals were esterified and subjected to GC-FID measurement, the behenic acid content was 96%, and in addition, 2% lignoceric acid, 2% arachidic acid, and 0.001% erucic acid were contained.
[0203]
<Preparation of fatty acid silver dispersion B>
Recrystallized behenic acid 88 kg, distilled water 422 L, 5 mol / L NaOH aqueous solution 49.2 L and t-butyl alcohol 120 L were mixed and stirred at 75 ° C. for 1 hour to react to obtain sodium behenate solution B. Separately, 206.2 L (pH 4.0) of an aqueous solution of 40.4 kg of silver nitrate was prepared and kept warm at 10 ° C. Keep the reaction vessel containing 635L of distilled water and 30L of t-butyl alcohol at 30 ° C, and with sufficient agitation, the total amount of the previous sodium behenate solution B and the total amount of silver nitrate aqueous solution are each 93 minutes at a constant flow rate. Added over seconds and 90 minutes. At this time, only the silver nitrate aqueous solution was added for 11 minutes after the start of the addition of the aqueous silver nitrate solution, and then the addition of the sodium behenate solution B was started. After the addition of the aqueous silver nitrate solution was completed, only the sodium behenate solution B was added for 14 minutes and 15 seconds. Was added. At this time, the temperature in the reaction vessel was 30 ° C., and the external temperature was controlled so that the liquid temperature was constant. The pipe of the addition system for the sodium behenate solution B was kept warm by circulating hot water outside the double pipe, and the liquid temperature at the outlet of the addition nozzle tip was adjusted to 75 ° C. Moreover, the piping of the addition system of the silver nitrate aqueous solution was kept warm by circulating cold water outside the double pipe. The addition position of the sodium behenate solution B and the addition position of the aqueous silver nitrate solution were symmetrically arranged around the stirring axis, and were adjusted so as not to contact the reaction solution.
[0204]
After completion of the addition of the sodium behenate solution B, the mixture was left stirring for 20 minutes at the same temperature, heated to 35 ° C. over 30 minutes, and then aged for 210 minutes. Immediately after completion of aging, the solid content was separated by centrifugal filtration, and the solid content was washed with water until the conductivity of filtered water reached 30 μS / cm. Thus, a fatty acid silver salt was obtained. The obtained solid content was stored as a wet cake without drying.
When the morphology of the obtained silver behenate particles was evaluated by electron microscope photography, the average value was a = 0.21 μm, b = 0.4 μm, c = 0.4 μm, the average aspect ratio 2.1, and the coefficient of variation of the equivalent sphere diameter was 11%. It was a crystal. (A, b, and c are the provisions of the text)
[0205]
Add 19.3 kg of polyvinyl alcohol (trade name: PVA-217) and water to a wet cake with a dry solid content of 260 kg, make the total amount 1000 kg, and then slurry with a dissolver blade. Pipeline mixer (manufactured by Mizuho Kogyo Co., Ltd .: PM-10 type).
[0206]
Next, the pre-dispersed stock solution is subjected to a disperser (trade name: Microfluidizer M-610, manufactured by Microfluidics International Corporation, using a Z-type interaction chamber) at a pressure of 1150 kg / cm²And was treated three times to obtain a silver behenate dispersion. The cooling operation was set to a dispersion temperature of 18 ° C. by installing a serpentine heat exchanger before and after the interaction chamber and adjusting the temperature of the refrigerant.
[0207]
(Preparation of reducing agent dispersion)
<< Preparation of Reducing Agent-1 Dispersion >>
Reducing agent-1 (2,2'-methylenebis- (4-ethyl-6-tert-butylphenol)) 10kg and denatured polyvinyl alcohol (Kuraray Co., Ltd., POVAL MP203) 10% by weight aqueous solution 16kg, 10kg water Add and mix well to make a slurry. This slurry was fed with a diaphragm pump, dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 3 hours, and 0.2 g of benzoisothiazolinone sodium salt Water was added to prepare a reducing agent concentration of 25% by mass. This dispersion was heat-treated at 60 ° C. for 5 hours to obtain a reducing agent-1 dispersion. The reducing agent particles contained in the reducing agent dispersion thus obtained had a median diameter of 0.40 μm and a maximum particle diameter of 1.4 μm or less. The obtained reducing agent dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust and stored.
[0208]
<< Preparation of Reducing Agent-2 Dispersion >>
10 mass of reducing agent-1 (6,6'-di-t-butyl-4,4'-dimethyl-2,2'-butylidenediphenol) and modified polyvinyl alcohol (Kuraray Co., Ltd., Poval MP203) 10 kg of water was added to 16 kg of% aqueous solution and mixed well to obtain a slurry. This slurry was fed with a diaphragm pump and dispersed for 3 hours 30 minutes in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm, and then benzoisothiazolinone sodium salt 0.2 g and water were added to prepare a reducing agent concentration of 25% by mass. This dispersion was heated at 40 ° C. for 1 hour, and then further heated at 80 ° C. for 1 hour to obtain a reducing agent-2 dispersion. The reducing agent particles contained in the reducing agent dispersion thus obtained had a median diameter of 0.50 μm and a maximum particle diameter of 1.6 μm or less. The obtained reducing agent dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust and stored.
[0209]
<< Preparation of hydrogen bonding compound-1 dispersion >>
Add 10 kg of water to 10 kg of 10% aqueous solution of hydrogen bonding compound-1 (tri (4-t-butylphenyl) phosphine oxide) and modified polyvinyl alcohol (Kuraray Co., Ltd., Poval MP203). Mix to make a slurry. This slurry was fed with a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 4 hours, and then 0.2 g of benzoisothiazolinone sodium salt Water was added to prepare a hydrogen bonding compound concentration of 25% by mass. This dispersion was heated at 40 ° C. for 1 hour and then further heated at 80 ° C. for 1 hour to obtain a hydrogen bonding compound-1 dispersion. The hydrogen bonding compound particles contained in the hydrogen bonding compound dispersion thus obtained had a median diameter of 0.45 μm and a maximum particle diameter of 1.3 μm or less. The obtained hydrogen bonding compound dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust and stored.
[0210]
<< Preparation of Development Accelerator-1 Dispersion >>
10 kg of water was added to 10 kg of a development accelerator-1 and 20 kg of a 10% by weight aqueous solution of modified polyvinyl alcohol (Kuraray Co., Ltd., Poval MP203) and mixed well to obtain a slurry. This slurry was fed with a diaphragm pump and dispersed for 3 hours 30 minutes in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm, and then benzoisothiazolinone sodium salt 0.2 g and water were added so that the concentration of the development accelerator was 20% by mass to obtain a development accelerator-1 dispersion. The development accelerator particles contained in the development accelerator dispersion thus obtained had a median diameter of 0.48 μm and a maximum particle diameter of 1.4 μm or less. The obtained development accelerator dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust and stored.
[0211]
(Preparation of solid dispersion of development accelerator-2 and color tone modifier-1)
The solid dispersions of the development accelerator-2 and the color tone modifier-1 were also dispersed by the same method as the development accelerator-1, and 20% by mass and 15% by mass of dispersions were obtained, respectively.
[0212]
(Preparation of polyhalogen compound)
<< Preparation of organic polyhalogen compound-1 dispersion >>
10 kg of organic polyhalogen compound-1 (tribromomethanesulfonylbenzene), 10 kg of a 20% by weight aqueous solution of modified polyvinyl alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.), 0.4 kg of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate, 14 kg of water was added and mixed well to make a slurry. This slurry was fed with a diaphragm pump and dispersed for 5 hours in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm. Then, 0.2 g of benzoisothiazolinone sodium salt Water was added to prepare an organic polyhalogen compound concentration of 26% by mass to obtain an organic polyhalogen compound-1 dispersion. The organic polyhalogen compound particles contained in the polyhalogen compound dispersion thus obtained had a median diameter of 0.41 μm and a maximum particle diameter of 2.0 μm or less. The obtained organic polyhalogen compound dispersion was filtered through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust and stored.
[0213]
<< Preparation of organic polyhalogen compound-2 dispersion >>
10 kg of organic polyhalogen compound-2 (N-butyl-3-tribromomethanesulfonylbenzoamide), 20 kg of 10% by weight aqueous solution of modified polyvinyl alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.), and 20 of sodium triisopropylnaphthalenesulfonate 0.4 kg of a mass% aqueous solution was added and mixed well to obtain a slurry. This slurry was fed with a diaphragm pump and dispersed for 5 hours in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm. Then, 0.2 g of benzoisothiazolinone sodium salt Water was added to adjust the concentration of the organic polyhalogen compound to 30% by mass. This dispersion was heated at 40 ° C. for 5 hours to obtain an organic polyhalogen compound-2 dispersion. The organic polyhalogen compound particles contained in the polyhalogen compound dispersion thus obtained had a median diameter of 0.40 μm and a maximum particle diameter of 1.3 μm or less. The obtained organic polyhalogen compound dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust and stored.
[0214]
<< Preparation of Phthalazine Compound-1 Solution >>
8 kg of Kuraray's modified polyvinyl alcohol MP203 is dissolved in 174.57 kg of water, then 3.15 kg of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate and a 70% by weight aqueous solution of phthalazine compound-1 (6-isopropylphthalazine). 14.28 kg was added to prepare a 5 mass% solution of phthalazine compound-1.
[0215]
(Preparation of mercapto compound)
<< Preparation of Mercapto Compound-1 Aqueous Solution >>
7 g of mercapto compound-1 (1- (3-sulfophenyl) -5-mercaptotetrazole sodium salt) was dissolved in 993 g of water to obtain a 0.7% by mass aqueous solution.
<< Preparation of Mercapto Compound-2 Aqueous Solution >>
20 g of mercapto compound-2 (1- (3-methylureido) -5-mercaptotetrazole sodium salt) was dissolved in 980 g of water to obtain a 2.0 mass% aqueous solution.
[0216]
<< Preparation of Pigment-1 Dispersion >>
C.I. Pigment Blue 60 (64 g) and Kao Co., Ltd. (Demol N) 6.4 g were mixed with 250 g of water and mixed well to form a slurry. Prepare 800 g of zirconia beads with an average diameter of 0.5 mm, put them in a vessel together with the slurry, disperse with a disperser (1 / 4G sand grinder mill: manufactured by IMEX Co., Ltd.) for 25 hours, add water to add pigment concentration Was prepared so as to be 5% by mass to obtain a pigment-1 dispersion. The pigment particles contained in the pigment dispersion thus obtained had an average particle size of 0.21 μm.
[0217]
<Preparation of SBR latex solution>
The SBR latex was prepared as follows.
In a polymerization kettle of a gas monomer reactor (TAS-2J type manufactured by Pressure Glass Industrial Co., Ltd.), 287 g of distilled water and a surfactant (Pionin A-43-S (manufactured by Takemoto Yushi Co., Ltd.)): solid content 48.5 %) 7.73 g, 1 mol / liter NaOH 14.06 ml, ethylenediaminetetraacetic acid tetrasodium salt 0.15 g, styrene 255 g, acrylic acid 11.25 g, tert-dodecyl mercaptan 3.0 g, the reaction vessel was sealed and the stirring speed was 200 rpm. Stir with. After degassing with a vacuum pump and repeating nitrogen gas replacement several times, 108.75 g of 1,3-butadiene was injected to raise the internal temperature to 60 ° C. A solution obtained by dissolving 1.875 g of ammonium persulfate in 50 ml of water was added thereto, and the mixture was stirred as it was for 5 hours. The mixture was further heated to 90 ° C. and stirred for 3 hours. After the reaction was completed, the internal temperature was lowered to room temperature, and then 1 mol / liter NaOH and NH._FourNa + ion: NH using OH_FourAddition treatment was performed so that + ion = 1: 5.3 (molar ratio), and the pH was adjusted to 8.4. Thereafter, the mixture was filtered through a polypropylene filter having a pore size of 1.0 μm to remove foreign substances such as dust and stored to obtain 774.7 g of SBR latex. When the halogen ions were measured by ion chromatography, the chloride ion concentration was 3 ppm. As a result of measuring the concentration of the chelating agent by high performance liquid chromatography, it was 145 ppm.
[0218]
The latex has an average particle size of 90 nm, Tg = 17 ° C., solid content concentration of 44% by mass, equilibrium water content of 0.6% by mass at 25 ° C. and 60% RH, and ionic conductivity of 4.80 mS / cm. A latex stock solution (44% by mass) was measured at 25 ° C. using a conductivity meter CM-30S manufactured by Kogyo Co., Ltd.).
SBR latexes having different Tg can be adjusted by the same method by appropriately changing the ratio of styrene and butadiene.
[0219]
<< Preparation of emulsion layer (photosensitive layer) coating solution-1 >>
Fatty acid silver dispersion A 1000 g obtained above, water 135 ml, pigment-1 dispersion 35 g, organic polyhalogen compound-1 dispersion 19 g, organic polyhalogen compound-2 dispersion 58 g, phthalazine compound-1 solution 162 g, SBR latex ( (Tg: 17 ° C.) Liquid 1060 g, reducing agent-1 dispersion 75 g, reducing agent-2 dispersion 75 g, hydrogen bonding compound-1 dispersion 106 g, development accelerator-1 dispersion 4.8 g, mercapto compound-1 aqueous solution 9 ml Then, 27 ml of mercapto compound-2 aqueous solution was sequentially added, and 118 g of silver halide mixed emulsion A 118 g was added and mixed well immediately before coating, and the emulsion layer coating solution was directly fed to the coating die and coated.
[0220]
The viscosity of the emulsion layer coating solution was 25 [mPa · s] at 40 ° C. (No. 1 rotor, 60 rpm) as measured with a B-type viscometer of Tokyo Keiki.
The viscosity of the coating solution at 38 ° C. using a Haake RheoStress RS150 is 32, 35, 33, 26, 17 [mPa · s] at shear rates of 0.1, 1, 10, 100, and 1000 [1 / sec], respectively. Met.
[0221]
The amount of zirconium in the coating solution was 0.32 mg per 1 g of silver.
[0222]
<< Preparation of emulsion layer (photosensitive layer) coating liquid-2 >>
Fatty acid silver dispersion B 1000 g obtained above, water 135 ml, pigment-1 dispersion 36 g, organic polyhalogen compound-1 dispersion 25 g, organic polyhalogen compound-2 dispersion 39 g, phthalazine compound-1 solution 171 g, SBR latex ( (Tg: 17 ° C.) Liquid 1060 g, reducing agent-2 dispersion 153 g, hydrogen bonding compound-1 dispersion 55 g, development accelerator-1 dispersion 4.8 g, development accelerator-2 dispersion 5.2 g, color tone adjuster- 2.1 g of 1 dispersion and 8 ml of the mercapto compound-2 aqueous solution were sequentially added, and the emulsion layer coating solution, in which 140 g of silver halide mixed emulsion A was added and mixed well immediately before coating, was directly fed to the coating die and coated.
The viscosity of the emulsion layer coating solution was 40 [mPa · s] at 40 ° C. (No. 1 rotor, 60 rpm) as measured with a B-type viscometer of Tokyo Keiki.
The viscosity of the coating solution at 38 ° C. using a Haake RheoStress RS150 is 30, 43, 41, 28, 20 [mPa · s] at shear rates of 0.1, 1, 10, 100, and 1000 [1 / sec], respectively. Met.
[0223]
The amount of zirconium in the coating solution was 0.30 mg per 1 g of silver.
[0224]
<Preparation of emulsion surface intermediate layer coating solution>
Polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.) 1000 g, pigment-1 dispersion 163 g, blue dye compound-1 (manufactured by Nippon Kayaku Co., Ltd .: Kayafect Turquoise RN Liquid 150) aqueous solution 33 g, sulfosuccinic acid di ( 2-ethylhexyl) sodium salt 5% aqueous solution 27ml, methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymerization weight ratio 57/8/28/5/2) latex 19 mass% solution 4200ml 27 ml of 5% by mass aqueous solution of Aerosol OT (American Cyanamid Co., Ltd.), 135 ml of 20% by mass aqueous solution of diammonium phthalate, and water so that the total amount becomes 10000 g, NaOH so that the pH is 7.5 8.9ml / m as an intermediate layer coating solution²Then, the solution was fed to the coating die.
The viscosity of the coating solution was 58 [mPa · s] when measured with a B-type viscometer at 40 ° C. (No. 1 rotor, 60 rpm).
[0225]
<< Preparation of emulsion surface protective layer first layer coating solution >>
Dissolve 100 g of inert gelatin and 10 mg of benzoisothiazolinone in 840 ml of water to obtain a methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymerization weight ratio 57/8/28/5/2) latex 19 180% by weight solution, 46ml of 15% by weight methanol solution of phthalic acid, and 5.4ml of 5% by weight aqueous solution of di (2-ethylhexyl) sulfosuccinate sodium salt are mixed together, and 40ml of 4% by weight chromium alum just before coating The amount of coating solution is 26.1ml / m.²Then, the solution was fed to the coating die.
The viscosity of the coating solution was 20 [mPa · s] at a B-type viscometer of 40 ° C. (No. 1 rotor, 60 rpm).
[0226]
<< Preparation of emulsion surface protective layer second layer coating solution >>
Inert gelatin (100 g) and benzoisothiazolinone (10 mg) are dissolved in water (800 ml). Methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymerization weight ratio 57/8/28/5/2) Latex 19 180% by weight liquid, 40 ml of 15% by weight phthalic acid methanol solution, 5.5 ml of 1% by weight solution of fluorosurfactant (F-1), 5.5% of 1% by weight aqueous solution of fluorosurfactant (F-2) ml, 28 ml of 5% by mass aqueous solution of di (2-ethylhexyl) sodium salt of sulfosuccinate, 4 g of polymethyl methacrylate fine particles (average particle size 0.7 μm), and 21 g of polymethyl methacrylate fine particles (average particle size 4.5 μm) 8.3ml / m as surface protective layer coating solution²Then, the solution was fed to the coating die.
The viscosity of the coating solution was 19 [mPa · s] at a B-type viscometer of 40 ° C. (No. 1 rotor, 60 rpm).
[0227]
<< Preparation of photothermographic material-1 >>
On the back side of the undercoat support, an antihalation layer coating solution is applied at a gelatin coating amount of 0.52 g / m.²In addition, the coating amount of the back surface protective layer is 1.7 g / m.²Then, a simultaneous multilayer coating was applied and dried to form a back layer.
[0228]
A photothermographic material sample was prepared on the surface opposite to the back surface by simultaneous multilayer coating by the slide bead coating method in the order of the emulsion layer, intermediate layer, protective layer first layer, and protective layer second layer from the undercoat surface. . At this time, the emulsion layer and the intermediate layer were adjusted to 31 ° C., the protective layer first layer was adjusted to 36 ° C., and the protective layer second layer was adjusted to 37 ° C.
Coating amount of each compound in the emulsion layer (g / m²) Is as follows.
[0229]
Silver behenate 5.42
Pigment (C.I.Pigment Blue 60) 0.036
Polyhalogen compound-1 0.12
Polyhalogen compound-2 0.25
Phthalazine Compound-1 0.18
SBR latex 9.70
Reducing agent-1 0.40
Reducing agent-2 0.40
Hydrogen bonding compound-1 0.58
Development accelerator-1 0.02
Mercapto Compound-1 0.002
Mercapto compound-2 0.012
Silver halide (as Ag) 0.10
[0230]
The coating and drying conditions are as follows.
The coating was performed at a speed of 160 m / min, the gap between the coating die tip and the support was set to 0.10 to 0.30 mm, and the pressure in the decompression chamber was set to 196 to 882 Pa lower than the atmospheric pressure. The support was neutralized with an ion wind before coating.
In the subsequent chilling zone, after cooling the coating liquid with wind at a dry bulb temperature of 10 to 20 ° C., it is transported in a non-contact type, and in a helical contactless dryer, the dry bulb temperature is 23 to 45 ° C., It dried with the dry wind of the wet bulb temperature 15-21 degreeC.
After drying, the humidity was adjusted at 25 ° C. and a humidity of 40-60% RH, and then the film surface was heated to 70-90 ° C. After heating, the film surface was cooled to 25 ° C.
The photothermographic material thus prepared had a Beck smoothness of 550 seconds on the photosensitive layer surface side and 130 seconds on the back surface. Further, the pH of the film surface on the photosensitive layer surface side was measured and found to be 6.0.
[0231]
<< Preparation of photothermographic material-2 >>
Photothermographic material-2 was produced in the same manner as photothermographic material-1, except that emulsion layer coating solution-1 was changed to emulsion layer coating solution-2 for photothermographic material-1.
The coating amount of each compound in the emulsion layer (g / m²) Is as follows.
[0232]
Silver behenate 5.27
Pigment (C.I.Pigment Blue 60) 0.036
Polyhalogen compound-1 0.14
Polyhalogen compound-2 0.28
Phthalazine Compound-1 0.18
SBR latex 9.43
Reducing agent-2 0.77
Hydrogen bonding compound-1 0.28
Development accelerator-1 0.019
Development accelerator-2 0.016
Color tone adjusting agent-1 0.006
Mercapto compound-2 0.003
Silver halide (as Ag) 0.13
[0233]
The chemical structures of the compounds used in the examples of the present invention are shown below.
[0234]
Embedded image
[0235]
Embedded image
[0236]
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[0237]
Embedded image
[0238]
(Evaluation of photographic performance)
The obtained samples were cut into half-cut sizes, packaged in the following packaging materials in an environment of 25 ° C. and 50%, stored at room temperature for 2 weeks, and then evaluated as follows.
(Packaging material)
PET 10μ / PE 12μ / Aluminum foil 9μ / Ny 15μ / Polyethylene 50% containing 3% carbon
Oxygen permeability: 0.02ml / atm · m²・ 25 ℃ ・ day, moisture permeability: 0.10g / atm ・ m²・ 25 ℃ ・ day
[0239]
Samples were exposed and heat-developed by Fuji Medical Dry Laser Imager FM-DP L (with a 660 nm semiconductor laser with a maximum output of 60 mW (IIIB)) (four panels set at 112 ° C-119 ° C-121 ° C-121 ° C) The heat-developable photosensitive material-1 was 24 seconds in total and the heat-developable photosensitive material-2 was 14 seconds in total) with a heater, and the obtained image was evaluated with a densitometer.
The two types of photothermographic materials produced as described above are subjected to heat development processing by the method described above, and it is confirmed that the heat development processor can be stably operated by comparing with the management data. The experiment shown in FIG.
[0240]
Example 1
With respect to the photothermographic material-1, the reducing agent-1 and the reducing agent-2 are excluded, but instead the comparative reducing agents shown in Table 1, the reducing agent of the general formula (R1) of the present invention, and the general formula ( Samples 001 to 020 using the reducing agent of R2) were prepared. The amount of the reducing agent used instead is shown in Table 1 as a relative ratio of the total number of moles of reducing agent-1 and reducing agent-2. That is, 100% means that the number of moles equal to the total number of moles of reducing agent-1 and reducing agent-2 is added, and 70% means the number of moles equivalent to 70% of the total number of moles. Means that
[0241]
Comparative reducing agent
Embedded image
[0242]
These samples were imagewise exposed using an FM-DPL laser imager, and each of the four heat-development plate temperatures of 112 ° C.-119 ° C.-121 ° C.-121 ° C. for 6 seconds each, 24 seconds in total as standard The heat development processing was performed as conditions. The relative sensitivity ΔS1.5 was determined from the logarithmic value of the exposure amount giving a density of 1.5.
Next, a practical image processed by standard development conditions was prepared by outputting images of CR lung field photographs and MR tomographic photographs, and the practical images were visually evaluated with a char-casten. Evaluation is evaluated by 10 observers, ◎ when 9 or more are determined to be preferable colors, ○ when 7 to 8 are determined to be preferable colors, and ○ when 4 to 6 persons are determined to be preferable colors When the number of people judged to be a preferable color was 3 or less, it was marked as x. In the following evaluations, it was evaluated in which direction the color tone was shifted.
[0243]
Furthermore, with respect to the standard conditions, (1) When the temperature of each plate is changed by ± 2 ° C, (2) When the total development time is changed by ± 2 seconds, (3) Each plate temperature is the total of + 1 ° C development time +1 second change, (4) each plate temperature changed by -1 ° C total development time by -1 second, (5) each plate temperature + 2 ° C total development time changed by -2 seconds, {Circle around (6)} The same heat development treatment was performed for each plate temperature when the total development time of −2 ° C. was changed by +2 seconds. The development time was changed so that the time of each plate was changed uniformly by changing the conveyance speed. In each sample, a * and b * values were measured at a concentration of 1.5 and plotted on a * b * coordinates. The distance r = {((Δa *) for the two points that are the most distant from each other²+ (Δb *)²) Square root} was calculated and the stability of the color tone was evaluated based on this value. Δa * and Δb * represent the difference between the a * value and the b * value at the two points that are the farthest apart. The smaller the r value, the smaller the color tone difference depending on the development conditions, which is preferable. The a * value and b * value were calculated for the FLF5 light source in accordance with the CIE 1976 standard.
[0244]
The evaluation results were expressed in four stages: ◎ when the r value was less than 0.5, ◯ when it was 0.5 or more and less than 1.0, Δ when it was 1.0 or more and less than 2.0, and 2.0 or more. This result was in good agreement with the result of visual sensory test.
[0245]
[Table 1]
[0246]
From Table 1, it can be seen that Samples 008 to 020, which are combinations of the present invention, are excellent in photothermographic materials with excellent color tone during standard development and small variations in color tone depending on development conditions.
[0247]
(Example 2)
Samples using the comparative reducing agent shown in Table 2 instead of reducing agent-2, the reducing agent of general formula (R1) of the present invention, and general formula (R2) instead of reducing agent-2 for photothermographic material-2 101-120 were produced. The addition amount is shown in Table 2 as a relative ratio to the addition amount of reducing agent-2.
These samples were also evaluated in the same manner as in Example 1. However, the laser imager used was a prototype of the apparatus described in Japanese Patent Application Nos. 2002-88832 and 2002-91114. The exposure part used a 50 mW semiconductor laser (660 nm), and the heat current part was a plate type heater controlled at 107 ° C.-121 ° C.-121 ° C. for 4.7 seconds each for a total heat development time of 14 seconds.
The obtained results are shown in Table 2.
[0248]
[Table 2]
[0249]
From Table 2, it can be seen that Samples 108 to 120, which are combinations of the present invention, have excellent color tone at the time of standard development, and are excellent photothermographic materials with little variation in color tone depending on development conditions.
From the above results, it can be seen that the combination of the reducing agents of the present invention can not only control the finished color tone to a preferable color tone, but also can significantly reduce fluctuations in the image color tone depending on the development conditions.
[0250]
【The invention's effect】
According to the present invention, a photothermographic material having a stable performance capable of always obtaining a constant color tone even when the heat development temperature or time varies is obtained.

Claims (10)

In a photothermographic material containing a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for heat development and a binder on the same surface of the support, as a reducing agent for the heat development, during heat development It contains at least one compound represented by the following general formula (R1) as a reducing agent that does not form a dye and at least one compound represented by the following general formula (R2) as a reducing agent that forms a dye. Photothermographic material characterized by:
Formula (R1)
(Wherein R ₁₁ and R ₁₂ each independently represents a secondary or tertiary alkyl group, R ₁₃ and R ₁₄ each independently represents an alkyl group having 2 or more carbon atoms, and R ₁₅ represents an alkyl group) .);
General formula (R2)
(Wherein R ₂₁ and R ₂₂ represent a secondary or tertiary alkyl group, and R ₂₃ and R ₂₄ each independently represent a hydrogen atom, a hydroxy group, an alkoxy group, an aryloxy group, an acyloxy group, an amino group, or a hetero group. R ₂₅ represents a hydrogen atom or an alkyl group . 2. The photothermographic material according to claim 1 , wherein the reducing agent represented by the general formula (R2) is from 5 mol% to 40 mol% with respect to the total reducing agent. 3. The photothermographic material according to claim 2, wherein the reducing agent represented by the general formula (R2) is 10 mol% or more and 30 mol% or less with respect to the total reducing agent. The photothermographic material according to any one of claims 1 to 3, further comprising a development accelerator. 5. The photothermographic material according to claim 4, wherein the development accelerator is a compound represented by the following general formula (A-1) or / and (A-2).
Formula (A-1)
Q1-NHNH-Q2
(In the formula, Q1 represents an aromatic group or a heterocyclic group bonded to —NHNH—Q2 at a carbon atom, and Q2 represents a carbamoyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfonyl group, or a sulfamoyl group. Represents.)
Formula (A-2)
(In the formula, R ₁ represents an alkyl group, an acyl group, an acylamino group, a sulfonamide group, an alkoxycarbonyl group, or a carbamoyl group, and R ₂ represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryloxy group, or an alkylthio group. Represents an arylthio group, an acyloxy group, or a carbonic acid ester group, and R ₃ and R ₄ each represents a substitutable group on the benzene ring and may be linked to each other to form a condensed ring. The photothermographic material according to any one of claims 1 to 5, further characterized by containing a hydrogen bonding compound. 7. The photothermographic material according to claim 6, wherein the hydrogen bonding compound is a compound represented by the following general formula (D).
Formula (D)
(Wherein R ²¹ to R ²³ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group or a heterocyclic group) The photothermographic material according to any one of claims 1 to 7, characterized by containing a compound represented by the following general formula (H).
General formula (H)
Q- (Y) n-C (Z ₁ ) (Z ₂ ) X
(Wherein Q represents an alkyl group, aryl group or heterocyclic group, Y represents a divalent linking group, n represents 0 or 1, Z ₁ and Z ₂ represent a halogen atom, and X represents hydrogen. Represents an atomic or electron withdrawing group.) The photothermographic material according to any one of claims 1 to 8, the total amount of coated silver is characterized in that it is 1.9 g / m ² or less. The photothermographic material according to any one of claims 1 to 9 , wherein the heat development time is 16 seconds or less.