JP2001194744A - Heat developable image recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable image recording material excellent in water resistance after development and having good performance by water- based coating less liable to adversely affect the environment. SOLUTION: The heat developable image recording material has at least one organic silver salt layer containing at least one non-photosensitive silver salt of an organic acid, a reducing agent for the silver salt and a binder on one face of the support and has an outermost protective layer containing a polymer latex having 20 to <70 deg.C glass transition temperature on the organic silver salt layer coated face or at least one face opposite to the organic silver salt layer coated face with respect to the supprot. The outermost protective layer becomes a water resistant protective layer simultaneously with heat development.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat-developable image recording material. The heat-developable image recording material of the present invention has excellent water resistance after development, and can be easily produced by aqueous coating with little adverse effect on the environment.

[0002]

2. Description of the Related Art There are many known photosensitive materials having a photosensitive layer on a support and forming an image by exposing the image. Among them, there is a technique of forming an image by thermal development as a system that contributes to environmental preservation and can simplify the image forming means. In recent years, in the field of photolithography, it has been strongly desired to reduce the amount of processing waste liquid from the viewpoint of environmental conservation and space saving. Therefore, there has been a need to develop a technology relating to a photothermographic material for photoengraving, which can be efficiently exposed by a laser scanner or a laser imagesetter and can form a clear black image having high resolution and sharpness. is needed. According to such a photothermographic material, it is possible to supply a simpler and less environmentally harmful heat development processing system to a customer, which does not require a solution processing chemical.

[0003] Among image forming materials, medical images are required to be finely described, so that high quality images having excellent sharpness and granularity are required. There is a feature that is preferred. At present, various hard copy systems using pigments and dyes, such as ink jet printers and electrophotographs, are distributed as general image forming systems, but none of them is satisfactory as a medical image output system.

A method of forming an image by thermal development is described in, for example, US Pat. Nos. 3,152,904 and 3,4,904.
57,075, and D.C. Crosta Bohr (K
"Heterically Processed Silver System (Thermal Processed)
Silver Systems) ”(Imaging
Processes and Materials (Imagin
g Processes and Material
s) Neblette Eighth Edition, Sturge
e), V.I. Walworth, A.M.
Shepp Edit, Chapter 9, pp. 279, 1
989). Such a photothermographic material includes a reducible non-photosensitive silver salt (for example, organic acid silver),
A catalytically active amount of a photocatalyst (eg, silver halide) and a silver reducing agent are usually contained in a dispersed state in an organic binder matrix. The photosensitive material is stable at normal temperature, but when heated to a high temperature (for example, 80 ° C. or higher) after exposure, silver is reduced through a redox reaction between a reducible silver salt (which functions as an oxidizing agent) and a reducing agent. Generate. This oxidation-reduction reaction is promoted by the catalytic action of the latent image formed by the exposure. The silver formed by the reaction of the reducible silver salt in the exposed areas becomes black and forms an image because it contrasts with the unexposed areas. US Patent 2,910,37
No. 7, the Japanese Patent Publication No. 43-4924, and many other documents.

Conventionally known photothermographic materials are:
In many cases, an image forming layer is formed by applying a coating solution using an organic solvent such as a ketone as a solvent. The use of an organic solvent as a solvent not only adversely affects the human body in the manufacturing process but also causes environmental problems. In addition, the cost for recovering the solvent is extremely high, and it is difficult to increase the production efficiency by simultaneous multi-layer coating, which is disadvantageous in cost. Then, a method of forming an image forming layer using a coating solution using water as a solvent has been proposed.

However, Japanese Patent Application Laid-Open No.
In a heat-developable image recording material using gelatin for a surface protective layer described in, for example, JP-A-1-119375, water resistance after heat development is not sufficient. Also, JP-A-11-28212
In a heat-developable image recording material having a surface protective layer containing a polymer latex as a main component described in JP-A No. 3
Although the water resistance after thermal development is good, the coated surface condition when high-speed simultaneous multi-layer coating is performed is not sufficient, and improvement is demanded.

[0007]

SUMMARY OF THE INVENTION Accordingly, a first object of the present invention is to provide a heat-developable image recording material having excellent water resistance after development. A second object is to provide a heat-developable image recording material having good performance by water-based coating which has little adverse effect on the environment.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventor has found that the intended effect can be obtained by forming a protective layer containing a specific material at a specific ratio on the surface. It has been found that an excellent heat-developable image recording material can be obtained, and the present invention has been provided. That is, the present invention relates to a heat-developable image recording material having at least one organic silver layer containing at least one non-photosensitive organic silver salt, a reducing agent for the organic silver salt and a binder on one surface of a support. An outermost protection containing a polymer latex having a glass transition temperature of 20 ° C. or more and less than 70 ° C. on at least one side of the organic acid silver layer-coated surface or the opposite side of the organic acid silver layer-coated surface and the support. A heat-developable image-recording material, characterized in that the heat-developable image-recording material comprises a water-resistant protective layer at the same time as heat development. In this heat-developable image recording material, the outermost protective layer preferably contains a water-soluble polymer and a polymer latex. Further, the polymer latex is preferably contained in an amount of 65 to 94% by weight based on the total binder amount of the outermost protective layer. The present invention also relates to a heat-developable image recording material having at least one non-photosensitive organic silver salt on one surface of a support, at least one organic acid silver layer containing a reducing agent for the organic silver salt and a binder. ,
An outermost protective layer containing a water-soluble polymer and a polymer latex is provided on at least one surface of the organic acid silver layer-coated surface side or the opposite side of the organic acid silver layer-coated surface and the support. Also provided is a heat-developable image recording material characterized in that it is contained in an amount of 65 to 94% by weight based on the total binder amount of the outermost protective layer. This heat-developable image recording material has a glass transition temperature of polymer latex of 20 ° C. or more and 70 ° C.
It is preferably less than. In the heat-developable image recording material of the present invention, the surface on which the outermost protective layer is formed is preferably the organic acid silver-coated surface side. At this time, it is preferable that the organic acid silver layer and the outermost protective layer are formed by simultaneous multi-layer coating. In addition, in this specification, "-" is a range including numerical values described before and after it as a minimum value and a maximum value.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the heat-developable image recording material of the present invention will be described in detail. The heat-developable image recording material of the present invention has, on one surface of a support, an organic acid silver layer containing a non-photosensitive organic silver salt, a reducing agent for the organic acid silver and a binder. The heat-developable image recording material of the present invention includes a heat-sensitive recording material in which the organic acid silver layer becomes a heat-sensitive recording layer, and a photothermographic material in which the organic acid silver layer further contains a photosensitive silver halide and becomes a photosensitive layer. .

The heat-developable image recording material of the present invention is characterized in that one or both surfaces thereof have an outermost protective layer whose water resistance is improved by heat development. The outermost protective layer specifically contains a water-soluble polymer and a polymer latex. The polymer latex contained in the outermost protective layer has a glass transition temperature of 20 ° C. or more and less than 70 ° C., and the content of the polymer latex is 65 to 94% by weight of the total binder amount of the outermost protective layer. By forming the outermost protective layer satisfying such conditions, it is possible to provide a heat-developable image recording material having improved water resistance by heat development and excellent blocking properties.

The water resistance of the outermost protective layer is evaluated by dropping water on the surface of the heat-developable image-recording material and then allowing it to stand at 25 ° C. for 1 minute to evaluate the increase in the thickness of the recording material, that is, the amount of swelling. Can be. Here, it is shown that the smaller the swelling amount, the better the water resistance. In this specification, "the outermost protective layer becomes a water-resistant protective layer simultaneously with thermal development" means that the swelling amount after thermal development is smaller than that before thermal development, and the swelling amount after thermal development is 2%.
μm or less. The swelling amount after thermal development is more preferably 1.5 μm or less, and further preferably 1 μm or less.
μm or less.

The water-soluble polymer used in the outermost protective layer of the heat-developable image recording material of the present invention includes, for example, gelatin,
Polyvinyl alcohol (PVA), polyacrylamide, a water-soluble (meth) acrylic polymer, a water-soluble saccharide polymer, and the like can be used, and PVA and a water-soluble saccharide polymer are preferably used. Examples of PVA include ordinary commercial PVA having a saponification degree of 80 to 99% and a polymerization degree of 200 to 5000, various modified polyvinyl alcohols (alkyl-modified PVA, anion-modified PVA, silane-modified PVA).
A, thiol-modified PVA, hydrophobic group-modified PVA, etc.). As the water-soluble saccharide polymer, water-soluble starch, dextran, pectin, agar, mannan, xanthan, carrageenan, pullulan, alginic acid, water-soluble cellulose derivatives (methylcellulose, hydroxycellulose, carboxymethylcellulose, hydroxypropylcellulose) and the like can be used. . In the outermost protective layer of the heat-developable image recording material of the present invention, the content of the water-soluble polymer is 6 to 5 times the total binder amount of the outermost protective layer.
It is preferably 35% by weight, more preferably 10% by weight.
３０30% by weight.

Examples of the polymer latex used in the outermost protective layer of the heat-developable image recording material of the present invention include latexes of methyl methacrylate / ethyl acrylate / methacrylic acid copolymer, methyl methacrylate / 2-ethylhexyl acrylate / styrene / acrylic acid copolymer Latex, styrene / butadiene / acrylic acid copolymer latex, styrene / butadiene / divinylbenzene / methacrylic acid copolymer latex, methyl methacrylate / vinyl chloride / acrylic acid copolymer latex, vinylidene chloride / ethyl acrylate / acrylonitrile / methacrylic acid copolymer latex Latex and the like can be mentioned.

The polymer latex used for the outermost protective layer of the heat-developable image recording material of the present invention has a glass transition temperature (T
g) is preferably from 20 ° C to less than 70 ° C, more preferably from 20 ° C to less than 60 ° C. If the Tg of the polymer latex is too low, adhesion failure tends to occur when the polymer latex is stored, and if the Tg is too high, water resistance tends to be hardly exhibited even after thermal development.

In the outermost protective layer of the heat-developable image recording material of the present invention, the content of the polymer latex is preferably 65 to 94% by weight, more preferably 70 to 90% by weight of the total binder of the outermost protective layer. %. The higher the content of the polymer latex, the better the water resistance is.However, if the content is too high, the surface tends to be skinned during the drying process, causing coating failures such as reticles, wrinkles, and cracks. Adjustment of the liquid viscosity also tends to be difficult. On the other hand, if the content of the polymer latex is too small, water resistance tends to hardly develop even after thermal development.

In the outermost protective layer of the heat-developable image recording material of the present invention, the coating amount of the water-soluble polymer and the polymer latex is 0.3 to 0.3 per outermost protective layer in total.
Is preferably 4.0 g / m ^2, more preferably from 0.3 to 2.0 g / m ^2.

The protective layer can be composed of two or more layers as required. For example, the adhesion is improved by providing two protective layers and providing a layer formed from a coating solution containing a water-soluble polymer emulsified dispersion and / or a hydrophobic polymer latex on the side close to the organic acid silver layer. be able to.
Also, lower the pH of the coating solution on the layer closer to the organic acid silver layer,
By making the pH of the coating solution of the surface side layer higher than 3.8, it is possible to achieve both image quality performance and production suitability, such as additives involved in development, a film surface pH adjuster, and a charge adjuster. By selecting an additive layer of an ultraviolet absorber, a slipping agent, and a hardening agent, it is possible to design such that both applicability, manufacturing suitability, and image quality performance are compatible.

In the present invention, a matting agent can be added to the outermost protective layer in order to improve blocking resistance and transportability. In addition, it can also be added to a layer functioning as the outermost protective layer or a layer near the outer surface. The matting agent is described in paragraph No. 0 of JP-A-11-65021.
126 to 0127. The amount of the matting agent used is preferably 1 to 400 mg / m ² , more preferably 5 to 300 mg / m ² , per 1 m ² of the recording material. The matte degree on the organic acid silver layer side may be any value as long as no stardust failure occurs, but the Beck smoothness is 30 to 2000.
Seconds, more preferably 40 to 150 seconds.
0 seconds. The matte degree of the back surface is Beck smoothness of 1
The time is preferably from 0 to 1200 seconds, more preferably from 20 to 800 seconds, and still more preferably from 40 to 500 seconds.
Seconds.

The back layer applicable to the present invention is described in paragraph No. 01 of JP-A-11-65021.
28-0130.

The non-photosensitive organic silver salt used in the present invention is:
Relatively stable to light, but forms a silver image when heated to 80 ° C. or higher in the presence of an exposed photocatalyst (such as a latent image of photosensitive silver halide) and a reducing agent It is a silver salt. The organic acid silver can be any organic material including a source of reducible silver ions. Such a non-photosensitive organic acid silver is disclosed in JP-A-10-62899.
No. 0048-0049, European Patent Publication E
P0803763A1, page 18, line 24 to
It is described on page 19, line 37. Silver salts of organic acids, especially (C10-C30, preferably 15-28
Silver salts of long chain aliphatic carboxylic acids are preferred. Preferred examples of organic acid silver include silver behenate, silver arachidate,
Examples include silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, and mixtures thereof. Organic acid silver can be used in a desired amount, preferably 0.1-5 g / m ² as silver amount, more preferably from 1 to 3 g / m ^2.

The shape of the non-photosensitive organic silver salt used in the present invention is not particularly limited, but scaly organic silver salt is preferred in the present invention. In the present specification, the flaky organic acid silver is defined as follows. The silver salt of an organic acid was observed with an electron microscope, and the shape of the silver salt of an organic acid was approximated to a rectangular parallelepiped. Then, calculation is performed using the shorter numerical values a and b, and x is obtained as follows. x = b / a x is obtained for about 200 particles in this manner,
Assuming that the average value x (average), x (average) ≧ 1.5
The one satisfying the above relationship is scaly. Preferably 30
≧ x (average) ≧ 1.5, more preferably 20 ≧ x (average) ≧ 2.0. By the way, needle shape is 1 ≦ x (average)
<1.5.

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

The particle size (volume-weighted average diameter) of the silver salt of an organic acid can be determined, for example, by irradiating a laser beam to a dispersion of solid fine particles dispersed in a liquid and obtaining the autocorrelation function with respect to the time change of the fluctuation of the scattered light. Desired. The average particle size is preferably from 0.05 to 10.0 μm, more preferably from 0.1 to 5.0 μm, even more preferably from 0.1 to 2.0 μm.

The particle size distribution of the non-photosensitive organic silver salt is preferably monodisperse. Monodispersion means that the percentage of the value obtained by dividing the standard deviation of the lengths of the minor axis and major axis by the minor axis and major axis, respectively, is preferably 100% or less, more preferably 80% or less, and still more preferably. It is the case of 50% or less. Another method of measuring monodispersity is to determine the standard deviation of the volume-weighted average diameter of the organic acid silver, wherein the percentage (coefficient of variation) divided by the volume-weighted average diameter is preferably 100% or less, It is preferably at most 80%, more preferably at most 50%.

The non-photosensitive organic silver salt used in the present invention is
The alkali metal salts of the organic acids exemplified above (Na salt, K
Salts, Li salts, etc.) solutions or suspensions and water-soluble silver salts such as silver nitrate. The organic acid alkali metal salt is obtained by treating an organic acid with an alkali. The preparation of the silver salt of an organic acid can be carried out batchwise or continuously in any suitable vessel. The stirring in the reaction vessel can be performed by any stirring method depending on the required characteristics of the particles. Examples of the method for preparing the organic acid silver include a method in which a water-soluble silver salt aqueous solution is gradually or rapidly added to a reaction vessel containing an organic acid alkali metal salt solution or suspension, and a method in which a water-soluble silver salt aqueous solution is contained in a reaction vessel. A method of slowly or rapidly adding a previously prepared organic acid alkali metal salt solution or suspension to a reaction vessel, and simultaneously adding a previously prepared aqueous silver salt aqueous solution and an organic acid alkali metal salt solution or suspension into a reaction vessel Any of the above methods can be preferably used.

The water-soluble silver salt aqueous solution and the organic acid alkali metal salt solution or suspension may be of any concentration for controlling the particle size of the prepared organic acid silver.
It can be added at any rate. The aqueous silver salt aqueous solution and the organic acid alkali metal salt solution or suspension can be added by a method of adding at a constant addition rate, an accelerated addition method by an arbitrary time function, or a deceleration addition method. Further, it may be added to the liquid surface or may be added to the reaction solution. In the case of a method of simultaneously adding a previously prepared aqueous solution of a water-soluble silver salt and a solution or suspension of an organic acid alkali metal salt into a reaction vessel,
Either a water-soluble silver salt aqueous solution or an organic acid alkali metal salt solution or suspension can be added in advance, but it is preferable to add a water-soluble silver salt aqueous solution in advance. The leading degree is preferably 0 to 50% by volume of the total addition amount, particularly preferably 0 to 25% by volume. In addition, Japanese Patent Application Laid-Open
As described in JP-A-1227643 and the like, a method of adding while controlling the pH or silver potential of the reaction solution during the reaction can also be preferably used.

The pH of the water-soluble silver salt aqueous solution or organic acid alkali metal salt solution or suspension to be added can be adjusted according to the required characteristics of the organic acid silver. Any acid or alkali can be added for pH adjustment. Depending on the required characteristics of the particles, for example, in order to control the particle size of the prepared organic acid silver, the temperature in the reaction vessel can be arbitrarily set. The alkali metal salt solution or suspension can also be prepared at any temperature. The organic acid alkali metal salt solution or suspension is 50 wt.
It is preferable to keep the temperature above ℃.

The non-photosensitive organic silver salt used in the present invention includes:
It is preferably prepared in the presence of a tertiary alcohol.
The tertiary alcohol preferably has a total carbon number of 15 or less,
Particularly preferred is 10 or less. Examples of preferred tertiary alcohols include tert-butanol. Third
The alcohol may be added at any time during the preparation of the organic acid silver salt, but it is preferable to add the alcohol during the preparation of the organic acid alkali metal salt and dissolve the organic acid alkali metal salt before use. The amount of the tertiary alcohol can be arbitrarily used in a weight ratio of 0.01 to 10 with respect to water as a solvent at the time of preparing the silver salt of an organic acid, but is preferably in a range of 0.03 to 1.

The scaly organic silver salt preferred in the present invention is obtained by reacting a water-soluble silver salt, preferably an aqueous solution of silver nitrate, with an aqueous tertiary alcohol solution of an organic acid alkali metal salt in a reaction vessel (in the reaction vessel). Adding a tertiary alcohol aqueous solution of an organic acid alkali metal salt to the solution)
Third liquid of alkali metal salt of organic acid to be added with liquid in reaction vessel
It is preferable that the temperature difference from the alcohol aqueous solution is 20 to 85 ° C, more preferably 30 to 80 ° C.
Manufactured as In this case, the temperature of the tertiary alcohol aqueous solution of the organic acid alkali metal salt is preferably higher. The temperature of the aqueous solution of the water-soluble silver salt when it is added to the reaction vessel is preferably 0 to 50 ° C, more preferably 5 to 30 ° C, and the temperature of the aqueous solution of the water-soluble silver salt and the third temperature of the organic acid alkali metal salt.
When adding an alcohol aqueous solution simultaneously, 5-15 degreeC is the most preferable. The temperature of the aqueous tertiary alcohol solution of the organic acid alkali metal salt is preferably from 50 to 90 ° C., more preferably from 60 to 85 ° C., and still more preferably from 65 to 90 ° C. for the purpose of avoiding crystallization and solidification of the organic acid alkali metal salt. ~ 85
° C. Further, it is preferable to control the reaction temperature within the above range.

By maintaining such a temperature difference during the addition of the tertiary alcohol aqueous solution of the organic acid alkali metal salt, the high temperature tertiary alcohol aqueous solution of the organic acid alkali metal salt is rapidly cooled in the reaction vessel to form microcrystalline The rate of precipitation of the organic acid silver salt in the reaction with the water-soluble silver salt is preferably controlled, and the crystal form, crystal size, and crystal size distribution of the organic acid silver salt can be preferably controlled. At the same time, the performance as a heat-developable image recording material, in particular, a heat-developable photosensitive material can be further improved.

The liquid in the reaction vessel is preferably an aqueous solution of a water-soluble silver salt previously added. When the aqueous solution of a water-soluble silver salt and an aqueous solution of a tertiary alcohol of an organic acid alkali metal salt are simultaneously added from the beginning. Is water or a mixed solvent of water and a tertiary alcohol. When the water-soluble silver salt aqueous solution is introduced first, water or a mixed solvent of water and a tertiary alcohol may be previously introduced into the reaction vessel.

Silver nitrate is preferred as the water-soluble silver salt, and the concentration of the water-soluble silver salt in the aqueous solution is 0.03 to 6.5 mol / mol.
1 is preferable, and more preferably, 0.1 to 5 mol / l
It is. The pH of the aqueous solution is preferably from 2 to 6, and more preferably from 3.5 to 6. In aqueous solutions of water-soluble silver salts,
A tertiary alcohol having 4 to 6 carbon atoms may be contained,
In that case, the content is 70% by volume or less, preferably 50% by volume or less based on the total volume of the aqueous solution of the water-soluble silver salt.

The alkali metal of the organic acid alkali metal salt is
Specifically, they are Na and K. Organic acid alkali metal salts are
It is prepared by adding NaOH or KOH to an organic acid. At this time, it is preferable that the amount of the alkali is equal to or less than the amount of the organic acid to leave unreacted organic acid.
In this case, the amount of the residual organic acid is 3 to 1 mol of the total organic acid.
To 50 mol%, preferably 3 to 30 mol%. Also, after adding the alkali in a desired amount or more,
It may be prepared by adding an acid such as nitric acid or sulfuric acid to neutralize excess alkali.

The aqueous tertiary alcohol solution of the alkali metal salt of an organic acid is preferably made of a mixed solvent of a tertiary alcohol having 4 to 6 carbon atoms and water in order to obtain a uniform solution. If the carbon number exceeds this, there is no compatibility with water, which is not preferable. Of the tertiary alcohols having 4 to 6 carbon atoms, tert-butanol, which is most compatible with water, is most preferred. Alcohols other than the tertiary alcohol are reducing as described above, and are harmful during the formation of silver organic acid. The amount of the tertiary alcohol used in combination with the aqueous tertiary alcohol solution of the organic acid alkali metal salt is 3 to 70% by volume based on the volume of water in the tertiary alcohol aqueous solution.
And preferably 5 to 50% by volume.

The concentration of the organic acid alkali metal salt in the tertiary alcohol aqueous solution is 7 to 50.
%, Preferably 7 to 45% by weight, more preferably 10 to 40% by weight.

An aqueous solution of a water-soluble silver salt, an aqueous tertiary alcohol solution of an alkali metal salt of an organic acid, or a solution in a reaction vessel includes, for example, a compound represented by formula (1) described in JP-A-62-65035, N-heterocyclic compounds containing a water-soluble group described in JP-A-62-150240, JP-A-50-1
Inorganic peroxides described in JP-A-01019, etc.
-78319, etc .;
A disulfide compound described in JP-A-7-643 and the like, hydrogen peroxide, and the like can be added.

The silver salt of an organic acid preferably used in the present invention may be prepared by a method in which a tertiary alcohol aqueous solution of an alkali metal salt of an organic acid is single-added to an aqueous solution in which an aqueous solution of a water-soluble silver salt firstly exists in a reaction vessel. Alternatively, it is produced by a method (simultaneous addition method) in which there is a time when an aqueous solution of a water-soluble silver salt and an aqueous solution of a tertiary alcohol of an organic acid alkali metal salt are simultaneously added to a reaction vessel. In the present invention, the latter method is preferred in that the average particle size of the organic acid silver salt is controlled and the distribution is narrowed. In this case, it is preferable to simultaneously add 30% by volume or more of the total amount, more preferably 50 to 75% by volume. When either of them is added in advance, it is preferable to add an aqueous solution of a water-soluble silver salt in advance.

In any case, the liquid in the reaction vessel (the aqueous solution of the water-soluble silver salt added in advance or the aqueous solution of the water-soluble silver salt in the case where the aqueous solution of the water-soluble silver salt is not added in advance is added to the reaction vessel in advance). The temperature of the solvent is preferably 5 to 75C, more preferably 5 to 60C, most preferably 10 to 50C. It is preferable to control the temperature to a certain temperature selected from the above temperatures throughout the whole process of the reaction, but it is also preferable to control the temperature in several temperature patterns within the above temperature range.

The aqueous tertiary alcohol solution of the organic acid alkali metal, the aqueous solution of the water-soluble silver salt, or the reaction solution may contain a dispersing aid soluble in the aqueous medium. Any dispersing agent may be used as long as it can disperse the formed organic acid silver salt. A specific example is in accordance with the description of the organic silver salt dispersing agent described below.

In the preparation of the non-photosensitive organic silver salt, desalting and dehydrating steps are preferably performed after the formation of the silver salt. The method is not particularly limited, and known and commonly used means can be used. For example, known filtration methods such as centrifugal filtration, suction filtration, ultrafiltration, floc-forming water washing by a coagulation method,
Supernatant removal by centrifugal sedimentation or the like is also preferably used. The desalting / dehydration may be performed once or plural times. The addition and removal of water may be performed continuously or individually. In the desalination and dehydration, the conductivity of the finally dehydrated water is preferably 300 μS / cm or less, more preferably 100 μS / cm or less, and most preferably 60 μS / cm.
/ Cm or less. The lower limit of the conductivity in this case is not particularly limited, but is usually about 5 μS / cm.

In order to improve the coated surface condition of the heat-developable image recording material, in particular, the heat-developable photosensitive material, an aqueous dispersion of an organic acid silver salt is obtained, which is converted into a high-speed flow at a high pressure, and then subjected to a pressure drop. By doing so, it is preferable to redisperse to obtain a fine water dispersion. In this case, the dispersion medium is preferably water alone, but may contain an organic solvent as long as it is 20% by weight or less. The method of dispersing the organic acid silver particles in a fine particle is performed by a known method of finely pulverizing in the presence of a dispersing aid (for example, a high-speed mixer,
Homogenizer, high-speed impact mill, Banbury mixer,
Homo mixer, kneader, ball mill, vibrating ball mill, planetary ball mill, attritor, sand mill, bead mill, colloid mill, jet mill, roller mill,
(Tron mill, high-speed stone mill) and can be dispersed mechanically.

When a photosensitive silver salt is present at the time of dispersing the non-photosensitive organic silver salt, fog increases and the sensitivity is remarkably reduced. Therefore, it is 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 of the non-photosensitive organic acid silver salt is 0.1 to 1 mol of the organic acid silver salt.
mol% or less, and no positive addition of a photosensitive silver salt is performed. In order to obtain a uniform solid dispersion of organic silver salt with high S / N, small particle size and no aggregation, a large force is required within a range that does not cause damage or high temperature of silver organic acid particles as an image forming medium. Is preferably provided uniformly. For this purpose, a dispersion method in which an aqueous dispersion composed of an organic acid silver salt and an aqueous solution of a dispersant is converted into a high-speed stream and then the pressure is reduced is preferable.

For the dispersion apparatus and the technique used for carrying out the redispersion method as described above, see, for example, “Dispersion Rheology and Dispersion Technique” (Toshio Kajiuchi, Hiroki Usui)
Author, 1991, Shinzansha Publishing Co., Ltd., p357-40
3), “Progress of Chemical Engineering Vol. 24,” edited by The Society of Chemical Engineers, Tokai Branch, 1990, Maki Shoten, p184-1
85), JP-A-59-49832, U.S. Pat. No. 4,533,254, JP-A-8-137944.
JP-A-8-238848 and JP-A-2-26152
No. 5, JP-A-1-94933, etc., the redispersion method of the present invention is to pressurize an aqueous dispersion containing at least a silver salt of an organic acid with a high-pressure pump or the like and feed it into a pipe. This is a method in which fine dispersion is performed by passing through a narrow slit provided in a pipe and then causing a sharp pressure drop in the dispersion.

As for the high-pressure homogenizer, generally, (a) “shearing force” generated when the dispersoid passes through a narrow gap (about 75 μm to 350 μm) at high pressure and high speed;
It is thought that the cavitation force due to the subsequent pressure drop is further increased without changing the impact force generated when liquid-liquid collision or wall collision occurs in a narrow space with high pressure, and uniform and efficient dispersion is performed. I have. An example of this type of dispersing device is a Gaulin homogenizer. The particles collide and are emulsified and dispersed by the impact force. Examples of the liquid-liquid collision include a Y-type chamber of a microfluidizer, a spherical chamber using a spherical check valve as described in JP-A-8-103542, and the like. And a Z-type chamber of a microfluidizer. The working pressure is generally in the range of 100 to 600 kg / cm ² , and the flow rate is in the range of several m to 30 m / sec. In order to increase the dispersion efficiency, the high-speed flow section is saw-toothed to increase the number of collisions. Things have also been devised. As typical examples of such an apparatus, a Gaulin homogenizer, a microfluidizer manufactured by Microfluidics International Corporation, a microfluidizer manufactured by Mizuho Industry Co., Ltd.,
Examples include Nanomizer manufactured by Tokushu Kika Kogyo Co., Ltd.
It is also described in JP-A-8-238848, JP-A-8-103364, and U.S. Pat. No. 4,533,254.

The non-photosensitive organic silver salt can be dispersed into a desired particle size by adjusting the flow rate, the differential pressure at the time of pressure drop, and the number of processings. The pressure difference at the time of pressure drop is preferably in the range of 900 to 3000 kg / cm ² , more preferably the flow rate of 300 to 600 m / sec, and the pressure difference at the time of pressure drop is 1500 to 3000 kg / cm ² . The number of times of the distributed processing can be selected as needed. Usually, the range of 1 to 10 times is selected, but from the viewpoint of productivity, about 1 to 3 times is selected. Heating such aqueous dispersions under high pressure is
At a high temperature exceeding 90 ° C., the particle size tends to increase and fog tends to increase, which is not preferable from the viewpoint of dispersibility and photographic properties. Therefore, the high pressure, the step before converting to high-speed flow, or the step after the pressure is reduced, or both these steps include a cooling device,
The temperature of such water dispersion is 5 ° C to 90 ° C depending on the cooling step.
Is preferably maintained in the range of 5 ° C to 80 ° C, more preferably in the range of 5 ° C to 65 ° C. In particular, 1500-3000k
At the time of dispersion at a high pressure in the range of g / cm ² , it is effective to provide the above cooling step. As the cooling device, a device using a static mixer for a double tube or a triple tube, a multi-tube heat exchanger, a coiled tube heat exchanger, or the like can be appropriately selected according to the required heat exchange amount. Further, in order to increase the efficiency of heat exchange, it is only necessary to select a suitable one such as a pipe thickness, a wall thickness and a material in consideration of a working pressure. As the refrigerant used for the cooler, a refrigerant such as well water at 20 ° C., cold water at 5 to 10 ° C. treated with a refrigerator, and ethylene glycol / water at −30 ° C. as necessary are used, based on the heat exchange amount. can do.

When the non-photosensitive organic silver salt is formed into fine solid particles using a dispersant, for example, polyacrylic acid, a copolymer of acrylic acid, a maleic acid copolymer, and a maleic acid monoester copolymer may be used. Acryloylmethylpropanesulfonic acid copolymer, semi-synthetic anionic polymers such as carboxymethyl starch and carboxymethylcellulose, anionic polymers such as alginic acid and pectic acid, JP-A-52-92716, and international publication. Anionic surfactants described in WO88 / 04794 and the like, compounds described in Japanese Patent Application No. 7-350753, known anionic, nonionic and cationic surfactants, and other polyvinyl alcohols and polyvinylpyrrolidone , Carboxymethylcellulose, hydroxyp Pills cellulose, known polymers such as hydroxypropyl methylcellulose, or a polymer compound existing in nature, such as gelatin can be suitably selected and used.

The dispersing agent is generally mixed with a silver salt of an organic acid or a silver salt of an organic acid in a wet cake state before dispersion, and then sent as a slurry to a dispersing machine. The mixture may be subjected to a heat treatment or a treatment with a solvent in a state of being mixed with the mixture to obtain an organic acid silver powder or a wet cake. The pH may be controlled with a suitable pH adjuster before, during or after dispersion. Besides mechanically dispersing, coarsely dispersing in solvent by controlling pH,
Thereafter, the pH may be changed in the presence of a dispersing aid to form fine particles. At this time, an organic acid solvent may be used as a solvent used for the coarse dispersion, and the organic solvent is usually removed after completion of the fine particle formation.

The prepared dispersion may be stored with stirring for the purpose of suppressing sedimentation of fine particles during storage, or stored in a highly viscous state (for example, in a jelly state using gelatin) with a hydrophilic colloid. You can also do.
Further, a preservative can be added for the purpose of preventing the propagation of various bacteria during storage. The organic acid silver prepared by the method for preparing an organic acid silver is preferably dispersed in an aqueous solvent, mixed with an aqueous solution of a photosensitive silver salt, and supplied as a coating solution for a photosensitive image forming medium.

Prior to the dispersion operation, the raw material liquid is roughly dispersed (preliminary dispersion). As means for coarsely dispersing, known dispersing means (for example, high-speed mixer, homogenizer, high-speed impact mill, Banbury mixer, homomixer, kneader, ball mill, vibrating ball mill, planetary ball mill, attritor, sand mill, bead mill, colloid mill,
Jet mill, roller mill, tron mill, high-speed stone mill) can be used. Besides mechanically dispersing, coarsely dispersing in solvent by controlling pH,
Thereafter, the pH may be changed in the presence of a dispersing agent to form fine particles. At this time, an organic solvent may be used as a solvent used for the coarse dispersion, and the organic solvent is usually removed after the completion of the fine particle formation.

In the present invention, when a photosensitive silver salt is used, the aqueous solution of the photosensitive silver salt is mixed after the organic acid silver is finely dispersed to prepare a coating solution for a photosensitive image forming medium. When a heat-developable image recording material is prepared using such a coating solution, a heat-developable image recording material having low haze, low fog and high sensitivity can be obtained. On the other hand, when converted to a high-pressure, high-speed flow and dispersed, the presence of a photosensitive silver salt causes fog to increase and the sensitivity to decrease significantly. When an organic solvent is used instead of water as a dispersion medium, haze increases, fog increases, and sensitivity tends to decrease. On the other hand, when a conversion method for converting a part of the organic acid silver in the dispersion to the photosensitive silver salt is used instead of the method of mixing the aqueous solution of the photosensitive silver salt, the sensitivity is lowered.

In the above, the aqueous dispersion converted and converted to high pressure and high speed is substantially free of a photosensitive silver salt, and its content is based on the non-photosensitive organic acid silver salt. The content is 0.1 mol% or less, and the photosensitive silver salt is not positively added.

The organic acid silver solid fine particle dispersion preferably used in the present invention is at least composed of organic acid silver and water. Although the ratio of the organic acid silver to water is not particularly limited, the ratio of the organic acid silver to the whole is 5 to 5%.
0% by weight, especially 10 to 30% by weight
Is preferable. It is preferable to use the above-mentioned dispersing aid, but it is preferable to use the dispersing aid in a minimum amount within a range suitable for minimizing the particle size. Is preferable.

In the present invention, a photosensitive material can be produced by mixing an aqueous dispersion of an organic acid silver and an aqueous dispersion of a photosensitive silver salt. The ratio of photosensitive silver salt to organic acid silver is 1
The range is preferably from 30 to 30 mol%, more preferably from 3 to 20 mol%, particularly preferably from 5 to 15 mol%. Mixing two or more kinds of aqueous dispersions of organic acid silver and two or more kinds of aqueous dispersions of photosensitive silver salts at the time of mixing is a method preferably used for adjusting photographic characteristics.

In the heat-developable image recording material of the present invention, a reducing agent for organic acid silver is contained in the organic acid silver layer. The reducing agent for the organic acid silver is any substance that reduces silver ions to metallic silver, preferably an organic substance. Specific examples of the reducing agent are disclosed in
No. 65021, paragraphs 0043 to 0045, and European Patent Publication EP0803764A1, page 7, line 34 to page 18, line 12. In the present invention, especially bisphenol reducing agents, for example,
1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane is preferred. The addition amount of the reducing agent is preferably from 0.01~5.0g / m ^2, more preferably from 0.1 to 3.0 g / m ^2, 1 mol of silver on the side having the organic acid silver layer Is preferably 5 to 50% by mole,
More preferably, it is contained at 0 mol%.

The reducing agent may be contained in the coating solution by any method such as a solution form, an emulsified dispersion form, and a solid fine particle dispersion form, and may be contained in the heat-developable image recording material. Well-known emulsification dispersion methods include oils such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, and dissolution using an auxiliary solvent such as ethyl acetate or cyclohexanone, and mechanically dispersing the emulsified dispersion. A method for producing the same is given. Also,
As a solid fine particle dispersion method, there is a method in which a powder of a reducing agent is dispersed in a suitable solvent such as water by a ball mill, a colloid mill, a vibrating ball mill, a sand mill, a jet mill, a roller mill or ultrasonic waves to form a solid dispersion. No. In this case, a protective colloid (for example, polyvinyl alcohol) or a surfactant (for example, an anionic surfactant such as sodium triisopropylnaphthalenesulfonate (a mixture of three isopropyl groups having different substitution positions)) may be used. Good. The aqueous dispersion can contain a preservative (eg, benzoisothiazolinone sodium salt).

As the binder used in the organic acid silver layer of the heat-developable image recording material of the present invention, a polymer dispersible in an aqueous solvent is particularly preferred. Examples of the dispersed state include a latex in which fine particles of a solid polymer are dispersed, an emulsion-dispersed one, a micelle-dispersed one, and a polymer molecule, particularly a polymer molecule having a hydrophilic portion in the molecule dispersed in a molecular state. These are all preferred, but polymer latex is particularly preferred.

Preferred examples of the binder used in the present invention include hydrophobic resins such as acrylic resins, polyester resins, rubber resins (for example, SBR resins), polyurethane resins, vinyl chloride resins, vinyl acetate resins, vinylidene chloride resins, and polyolefin resins. Polymers. The polymer may be a linear polymer, a branched polymer, a crosslinked polymer, a so-called homopolymer in which a single monomer is polymerized,
A copolymer in which two or more kinds of monomers are polymerized may be used. In the case of a copolymer, it may be a random copolymer or a block copolymer. The molecular weight of the polymer is from 5,000 to 1,000,000 in number average molecular weight, preferably from 1,000 to 1,000.
0 to 200,000. If the molecular weight is too small, the mechanical strength of the organic acid silver layer is insufficient, and if it is too large, the film formability is poor, which is not preferable.

Specific examples of preferable polymer latex include the following. In the following, the raw material monomers are used, and the values in parentheses are% by weight, and the molecular weight is the number average molecular weight. P-1; -MMA (70) -EA (27) -MAA
(3) -Latex (molecular weight 37000) P-2; -MMA (70) -2EHA (20) -St
(5) Latex of -AA (5)-(molecular weight 4000
0) P-3; -St (50) -Bu (47) -MAA (3)
-Latex (molecular weight 45000) P-4; -St (68) -Bu (29) -AA (3)-
Latex (molecular weight 60000) P-5; -St (70) -Bu (27) -IA (3)-
Latex (molecular weight 120,000) P-6; -St (75) -Bu (24) -AA (1)-
Latex (molecular weight 108000) P-7; -St (60) -Bu (35) -DVB (3)
-MAA (2)-latex (molecular weight 150,000) P-8; -St (70) -Bu (25) -DVB (2)
-AA (3)-latex (molecular weight 280000) P-9; -VC (50) -MMA (20) -EA (2
Latex of 0) -AN (5) -AA (5)-(molecular weight: 80000) P-10; -VDC (85) -MMA (5) -EA
Latex of (5) -MAA (5)-(molecular weight 6700
0) Latex of P-11; -Et (90) -MAA (10)-(molecular weight 12000) P-12; -St (70) -2EHA (27) -AA
Latex of (3) (molecular weight 130000) P-13; -MMA (63) -EA (35) -AA
Latex of (2) (molecular weight 33000)

Abbreviations of 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;
C; vinyl chloride, AN; acrylonitrile, VDC; vinylidene chloride, Et; ethylene, IA; itaconic acid.

The polymer latex described above is also commercially available, and the following polymers can be used. Examples of acrylic resins include Sebian A-4635, 46
583, 4601 (all manufactured by Daicel Chemical Industries, Ltd.),
Nipol Lx811, 814, 821, 820, 8
Examples of polyester resins such as 57 (all manufactured by Nippon Zeon Co., Ltd.) include FINETEX ES650, 61
1,675,850 (Dai Nippon Ink Chemical Co., Ltd.)
Examples of polyurethane resins such as WD-size and WMS (all manufactured by Eastman Chemical) include HYD
Examples of rubber-based resins such as RAN AP10, 20, 30, 40 (all manufactured by Dainippon Ink and Chemicals, Inc.) include LA
CSTAR7310K, 3307B, 4700H, 71
32C (all manufactured by Dainippon Ink and Chemicals, Inc.), Nipol
Examples of vinyl chloride resins such as Lx416, 410, 438C, 2507 (all manufactured by Nippon Zeon Co., Ltd.) include G
Examples of vinylidene chloride resins such as 351 and G576 (all manufactured by Zeon Corporation) include L502 and L513.
Examples of the olefin resin such as (manufactured by Asahi Kasei Kogyo Co., Ltd.) include Chemipearl S120 and SA100 (manufactured by Mitsui Petrochemical Co., Ltd.).

These polymer latexes may be used alone, or may be used in combination of two or more as required. As the polymer latex used as the binder in the invention, a styrene-butadiene copolymer latex is particularly preferred. The weight ratio of the styrene monomer unit to the butadiene monomer unit in the styrene-butadiene copolymer is preferably from 40:60 to 95: 5. The ratio of the styrene monomer unit to the butadiene monomer unit in the copolymer is 60 to 99.
% By weight. The preferred molecular weight range is the same as described above. Preferred styrene-butadiene copolymer latexes include the aforementioned P-3 to P-8, commercially available LACSTAR-3307B, 7132C,
Nipol Lx416 and the like.

The amount of the binder in the organic acid silver layer is from 0.2 to
It is preferably 30 g / m ² , more preferably 1 g / m ^2.
１５15 g / m ² . The weight ratio of the binder / organic acid silver in the organic acid silver layer is preferably 1/10 to 10/1, and more preferably 1/5 to 4/1. The organic acid silver layer is usually a photosensitive layer containing a photosensitive silver halide which is a photosensitive silver salt, and in this case, the weight ratio of binder / silver halide is preferably 400 to 5, More preferably, it is 200 to 10.

In the heat-developable image recording material of the present invention,
When the organic acid silver-containing layer is formed using a coating solution in which 30% by weight or more of the solvent is water and dried, the binder of the organic acid silver-containing layer can be further added to an aqueous solvent (aqueous solvent). It is dissolvable or dispersible, especially when it consists of a latex of a polymer having an equilibrium water content of 2% by weight or less at 25 ° C. and 60% relative humidity. The most preferred form is prepared so that the ionic conductivity becomes 2.5 mS / cm or less. As such a preparation method, a method of purifying using a separation functional membrane after polymer synthesis can be mentioned.

The aqueous solvent in which the polymer is soluble or dispersible is water or a mixture of water and 70% by weight or less of a water-miscible organic solvent. Examples of the water-miscible organic solvent include alcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol; cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; ethyl acetate; and dimethylformamide. Note that the term “aqueous solvent” is used herein even in a system in which the polymer is not thermodynamically dissolved but exists in a so-called dispersed state.

The “equilibrium moisture content at 25 ° C. and 60% relative humidity” refers to the weight W1 of the polymer which is in a moisture-conditioning equilibrium in an atmosphere of 25 ° C. and 60% relative humidity, and the weight of the polymer which is in a completely dry state at 25 ° C. It can be expressed as follows using W0. Equilibrium water content at 25 ° C. and 60% relative humidity = ｛(W1-
W0) / W0] × 100 (% by weight) For the definition and measurement method of water content, for example, Polymer Engineering Course 14, Polymer Material Testing Method (Polymer Society, Jinjinshokan)
Can be referred to. The binder polymer used in the present invention preferably has an equilibrium water content at 25 ° C. and a relative humidity of 60% of 2% by weight or less, more preferably 0.01 to 1.5% by weight, and still more preferably 0.02% by weight.
2 to 1% by weight.

In the present invention, the organic acid silver layer contains 30 water.
It is preferable to prepare by applying a coating solution using an aqueous solvent containing not less than% by weight (here, for simplicity, the solvent and the dispersion medium are collectively referred to as a solvent), followed by drying after coating. The water content of the aqueous solvent in the coating liquid is preferably at least 50% by weight, more preferably at least 70% by weight. As a component other than water of the aqueous solvent, any water-miscible organic solvent such as methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, and ethyl acetate can be used. Examples of preferred solvent compositions include water / methyl alcohol = 90 /
10, water / methyl alcohol = 70/30, water / methyl alcohol / dimethylformamide = 80/15/5,
Water / methyl alcohol / ethyl cellosolve = 85/10
/ 5, water / methyl alcohol / isopropyl alcohol = 85/10/5, etc. (numerical values represent weight%).

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

Methods of forming photosensitive silver halide are well known in the art and are described, for example, in Research Disclosure No. 17029, June 1978, and US Pat. No. 3,700,458. Specifically, a photosensitive silver halide is prepared by adding a silver supply compound and a halogen supply compound to a gelatin or other polymer solution, and then mixed with an organic acid silver salt Method.

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 to 0.15 μm. More preferably 0.02-
0.12 μm. The grain size as used herein means that when the silver halide grains are cubic or octahedral so-called normal crystals, and when they are not normal crystals, for example, in the case of spherical grains, rod-like grains, etc., the volume of the silver halide grains is It refers to the diameter when considering equivalent spheres, and when the silver halide grains are tabular grains, it refers to the diameter when converted into a circular image having the same area as the projected area of the main surface.

The shape of the silver halide grains is cubic,
Octahedral, tabular particles, spherical particles, rod-like particles, potato-like particles and the like can be mentioned. In the present invention, cubic particles are particularly preferable. Grains having rounded corners of silver halide grains can also be preferably used. The surface index (mirror index) of the outer surface of the photosensitive silver halide grains is not particularly limited. However, the spectral sensitization efficiency when the spectral sensitizing dye is adsorbed is high. preferable. The ratio is preferably 50% or more, more preferably 65% or more, and still more preferably 80% or more. The ratio of the {100} plane of the Miller index is determined by the T.M. Tani; Imaging Sc
i. , 29, 165 (1985).

The photosensitive silver halide grains preferably contain a metal or a metal complex of Group 8 to Group 10 of the periodic table (showing Groups 1 to 18). Eighth of the periodic table
As a central metal of a metal or a metal complex of Group 10 to Group 10,
Preferably, they are rhodium, rhenium, ruthenium, osmium, and iridium. One type of these metal complexes may be used, or two or more types of complexes of the same metal and different metals may be used in combination. The preferred content is 1 × 10
The range is from ^-9 mol to 1 × 10 ^-3 mol. These metal complexes are described in JP-A-11-65021, paragraphs 0018 to 0024.

In the present invention, halogenated
It is preferable to include an iridium compound in the silver particles.
No. As the iridium compound, for example, hexachloro
Iridium, hexaammine iridium, trioxara
Toridium, hexacyanoiridium, pentachloro
Nitrosyl iridium and the like. These iris
Compound is dissolved in water or a suitable solvent.
To stabilize the solution of the iridium compound
Commonly used method, ie, hydrogen halide water
Solution (for example, hydrochloric acid, bromic acid, hydrofluoric acid, etc.) or halogen
Alkali halides (eg, KCl, NaCl, KBr, Na
(Br, etc.) can be used. Water soluble
Instead of using iridium, when preparing silver halide,
Another halogenation pre-doped with iridium
It is also possible to add and dissolve silver particles. these
The amount of the iridium compound added was 1 mole per silver halide.
1 × 10^-8Mol ~ 1 x 10^-3Molar ranges are preferred,
1 × 10^-7Mol ~ 5 x 10 ^-FourMolar range is more preferred
No.

The metal atoms (eg, [Fe (CN) ₆ ] ^4- ) which can be contained in the silver halide grains, the desalting method and the chemical sensitization method are described in JP-A-11-84574, paragraph number. 0046-0050, JP-A-11-65
No. 021, paragraphs 0025 to 0031.

The photosensitive silver halide emulsion used in the heat-developable image recording material of the present invention may be only one kind or two or more kinds (for example, those having different average grain sizes, those having different halogen compositions, those having different habits). Different ones, or different ones under different conditions of chemical sensitization). The gradation can be adjusted by using a plurality of photosensitive silver halides having different sensitivities. The technology relating to these is disclosed in
19341, 53-106125, 4
Nos. 7-3929, 48-55730, and 4
Nos. 6-5187, 50-73627 and 5
No. 7-150841. The difference in sensitivity is preferably 0.2 logE or more for each emulsion.

The amount of photosensitive silver halide added was 0.03, expressed as the amount of silver applied per m ² of the heat-developable image recording material.
Is preferably ~0.6g / m ^2, more preferably from 0.05 to 0.4 g / m ^2, more preferably from 0.1 to 0.4 g / m ^2. Further, the photosensitive silver halide is preferably 0.01 to 0.5 mol, more preferably 0.02 to 0.3 mol, and still more preferably 0.03 to 0 mol per mol of the organic acid silver. .25 mol.

Regarding the mixing method and mixing conditions of the separately prepared photosensitive silver halide and organic acid silver, the prepared silver halide particles and the organic acid silver are mixed with a high-speed stirrer, a ball mill, a sand mill, a colloid mill, and a vibrator. Mills, a method of mixing with a homogenizer, or the like, or a method of preparing organic acid silver by mixing photosensitive silver halide prepared at any timing during the preparation of organic acid silver, etc. There is no particular limitation as long as the effect appears sufficiently.

The timing of adding the silver halide of the present invention to the coating solution for the image forming layer is preferably from 180 minutes to immediately before coating, and preferably from 60 minutes to 10 seconds before coating. Is not particularly limited as long as the effects of the present invention are sufficiently exhibited. Specific mixing methods include a method of mixing in a tank in which the average residence time calculated from the addition flow rate and the amount of liquid sent to the coater is a desired time, Harnby, M .; F. Edwar
ds, A.D. W. There is a method using a static mixer or the like described in Chapter 8 of Nienow, "Liquid Mixing Technology" translated by Koji Takahashi (Nikkan Kogyo Shimbun, 1989).

The organic acid silver layer of the heat-developable image recording material of the present invention may optionally contain a hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose, or hydroxypropylcellulose. The addition amount of these hydrophilic polymers is 30% by weight of the total binder of the organic acid silver layer.
Or less, more preferably 20% by weight or less.

The image forming layer of the present invention may contain a crosslinking agent for crosslinking and a surfactant for improving coating properties. The surfactant applicable to the present invention is described in paragraph No. 0132 of JP-A-11-65021, and the solvent is described in paragraph No. 0133 of the same publication.

A hardener may be used for each layer such as the organic acid silver layer, protective layer and back layer of the present invention. Examples of hardeners include T.I. H. James "THE THEORY OF"
THE PHOTOGRAPHIC PROCESS
FOURTH EDITION "(Macmillan
Publishing Co. , Inc. Published, 197
The methods are described on pages 77-87, 7th edition.
Polyvalent metal ions described in US Pat. No. 4,281,
060, JP-A-6-208193, and the like, US Pat. No. 4,791,042.
Compounds described in JP-A-62-890
For example, vinyl sulfone-based compounds described in JP-A-48-48 are preferably used.

The hardener is added as a solution. The time of adding this solution to the coating solution for the outermost protective layer is from 180 minutes to immediately before coating, preferably from 60 minutes to 10 seconds before coating. The method and mixing conditions are not particularly limited as long as the effects of the present invention are sufficiently exhibited. As a specific mixing method, there is a method of mixing in a tank in which the average residence time calculated from the addition flow rate and the amount of liquid sent to the coater is set to a desired time, Harnby, M .; F. Ed
wards, A.M. W. Nienow, "Liquid Mixing Technology" translated by Koji Takahashi (Nikkan Kogyo Shimbun, 1989), 8th edition
There is a method using a static mixer or the like described in a chapter or the like.

The sensitizing dye applicable to the present invention is a sensitizing dye capable of spectrally sensitizing silver halide grains in a desired wavelength region when adsorbed on silver halide grains, and having a spectral sensitivity suitable for the spectral characteristics of an exposure light source. Can be advantageously selected. For sensitizing dyes and addition methods, see JP-A-11-65021, paragraph numbers 0103 to 0109,
JP-A-10-186572, a compound represented by the general formula (II), which is described in EP-A-0803764A1, page 19, line 38 to page 20, line 35. In the present invention, the time when the sensitizing dye is added to the silver halide emulsion is preferably after the desalting step and before coating, and more preferably after desalting and before the start of chemical ripening.

The antifoggant, stabilizer and stabilizer precursor which can be used in the present invention are described in JP-A-10-6289.
No. 9, paragraph No. 0070, European Patent Publication EP080
Patents described on page 20, line 57 to page 21, line 7 of 3764A1 are mentioned. The antifoggant preferably used in the present invention is an organic halide, and examples thereof include those disclosed in the patents described in paragraphs 0111 to 0112 of JP-A-11-65021. In particular, JP-A-10-3399
No. 34, an organic polyhalogen compound represented by the general formula (II) (specifically, tribromomethylnaphthylsulfone, tribromomethylphenylsulfone, tribromomethyl (4- (2,4,6-trimethylphenylsulfonyl) ) Phenyl) sulfone and the like) are preferred.

As a method for incorporating the antifoggant into the heat-developable image recording material, the method described in the above-mentioned method for containing the reducing agent can be mentioned, and the organic polyhalogen compound is preferably added in the form of a solid fine particle dispersion. Other antifoggants include mercury (II) salt of paragraph No. 0113 of JP-A-11-65021 and paragraph No. 011 of the same publication.
4 benzoic acids.

The heat-developable image recording material of the present invention may contain an azolium salt for the purpose of preventing fog. Examples of the azolium salt include compounds represented by the general formula (XI) described in JP-A-59-193449, and JP-B-55-12.
No. 581, JP-A-60-15303
No. 9 discloses a compound represented by the general formula (II). The azolium salt may be added to any part of the recording material. However, it is preferable to add the azolium salt to the layer having the organic acid silver layer, and it is more preferable to add the azolium salt to the organic acid silver layer. The azolium salt may be added at any time during the preparation of the coating solution, and when the azolium salt is added to the organic acid silver layer, it may be at any time during the preparation of the coating solution from the preparation of the organic acid silver. To just before application. Powders, solutions,
Any method such as a fine particle dispersion may be used. Also,
It may be added as a solution mixed with other additives such as a sensitizing dye, a reducing agent and a color tone agent. In the present invention, the azolium salt may be added in any amount, but is preferably 1 × 10 ⁻⁶ to 2 mol per mol of silver, and preferably 1 × 10 ^{−3 to} 0.5 mol.
Mole is more preferred.

In the present invention, a mercapto compound, a disulfide compound, and a thione compound are contained to control development by suppressing or accelerating development, to improve spectral sensitization efficiency, and to improve storage stability before and after development. Can be done. A specific example is disclosed in JP-A-10-6289.
No. 9, paragraphs 0067 to 0069;
186572, a compound represented by the general formula (I),
It is described on page 20, lines 36-56 of EP 0803764A1. Among them, mercapto-substituted heteroaromatic compounds are preferred.

In the present invention, it is preferable to add a color toning agent. For the color toning agent, paragraphs [0054] to [0055] of JP-A-10-62899, and European Patent Publication EP080376.
No. 4A1, page 21, lines 23 to 48, particularly, phthalazinone, phthalazinone derivatives or metal salts, or 4- (1-naphthyl) phthalazinone,
Derivatives such as -chlorophthalazinone, 5,7-dimethoxyphthalazinone and 2,3-dihydro-1,4-phthalazinedione; phthalazinone and phthalic acid derivatives (for example, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid) Acid and tetrachlorophthalic anhydride, etc.);
Phthalazines (phthalazine, phthalazine derivative or metal salt, or 4- (1-naphthyl) phthalazine, 6-
Derivatives such as isopropylphthalazine, 6-tert-butylfuratazine, 6-chlorophthalazine, 5,7-dimethoxyphthalazine and 2,3-dihydrophthalazine); phthalazines and phthalic acid derivatives (for example, phthalic acid, Combinations with 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride are preferred,
Particularly, a combination of phthalazines and a phthalic acid derivative is preferable. The color toning agent can be contained in the outermost protective layer on the side of the organic acid silver layer, a layer thereunder, the organic acid silver layer, and the like.

The plasticizers and lubricants that can be used in the organic acid silver layer of the present invention are described in JP-A-11-6502.
Paragraph No. 0117 of JP-A No. 1 and a super-high contrast agent for forming an ultra-high contrast image are described in paragraphs 0118 of the same gazette and Japanese Patent Application No. 11-91652, which are represented by general formulas (III) to (V).
(Specific compounds: Chemical formulas 21 to 24) and a contrast enhancement accelerator are described in paragraph No. 0102 of JP-A-11-65021.

In the present invention, various dyes and pigments can be used in the organic acid silver layer from the viewpoints of improving color tone, preventing interference fringes during laser exposure, and preventing irradiation. These are described in detail in International Publication WO98 / 36322. Preferred dyes and pigments include anthraquinone dyes, azomethine dyes, indoaniline dyes, azo dyes, and anthraquinone-based indanthrone pigments (CI Pigment Blue 60).
Phthalocyanine pigments (CI Pigment)
Copper phthalocyanine such as Blue 15, C.I. I. Pig
metal-free phthalocyanine such as Ment Blue 16), triarylcarbonyl pigments based on dyeing lake pigments, indigo, inorganic pigments (ultramarine, cobalt blue, etc.)
Is mentioned. As a method of adding these dyes and pigments,
Any method such as a solution, an emulsion, a solid fine particle dispersion, and a state in which it is mordanted with a polymer mordant may be used. The amount of these compounds to be used is determined depending on the desired absorption amount, but it is generally preferable to use them in the range of 1 μg to 1 g per 1 m ² of the recording material.

In the present invention, the antihalation layer can be provided on the side farther from the light source than the organic acid silver layer. For the antihalation layer, see JP-A-11-65.
No. 021, paragraphs 0123 to 0124. In the invention, a decolorizable dye and a base precursor are added to the non-photosensitive layer of the heat-developable image recording material, so that the non-photosensitive layer can function as a filter layer or an antihalation layer. A photothermographic material generally has a non-photosensitive layer in addition to a photosensitive layer. The non-photosensitive layer is composed of (1) an outermost protective layer provided on the photosensitive layer (on the side farther than the support) from its disposition, and (2) an outermost protective layer between a plurality of photosensitive layers or with the photosensitive layer. It can be classified into an intermediate layer provided between the protective layers, (3) an undercoat layer provided between the photosensitive layer and the support, and (4) a back layer provided on the opposite side of the photosensitive layer. The filter layer is provided on the photosensitive material as the layer (1) or (2). The antihalation layer is (3) or (4)
Is provided on the photosensitive material.

When a decoloring dye and a base precursor are used, they are preferably added to the same non-photosensitive layer. However, they may be separately added to two adjacent non-photosensitive layers. Further, a barrier layer may be provided between the two non-photosensitive layers. As a method of adding the decolorable dye to the non-photosensitive layer, a method of adding a solution, an emulsion, a solid fine particle dispersion, or a polymer impregnated substance to the coating solution of the non-photosensitive layer can be adopted. Further, a dye may be added to the non-photosensitive layer using a polymer mordant. These addition methods are the same as the method of adding a dye to a usual heat-developable image recording material. Latexes used in polymer impregnations are described in U.S. Pat. No. 4,199,363 and West German Patent Publication No. 2514127.
No. 4,254,230, European Patent Publication EP
No. 029104 and JP-B-53-41091. Regarding an emulsification method for adding a dye to a solution in which a polymer is dissolved, see International Publication WO 88 /
No. 00723.

The amount of the decolorizable dye is determined depending on the use of the dye. Generally, the optical density (absorbance) measured at the desired wavelength is used in an amount exceeding 0.1. The optical density is preferably from 0.2 to 2. The amount of the dye used to obtain such an optical density is generally 0.00
About 1 to 1 g / m ² , and particularly preferably 0.01 to 1 g / m ^2.
About 0.2 g / m ² . When the dye is decolored in this manner, the optical density can be reduced to 0.1 or less. Two or more decolorizable dyes may be used in combination in a heat-decolorable recording material or a photothermographic material. Similarly, two or more base precursors may be used in combination.

The heat-developable image recording material of the present invention may further contain an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber or a coating aid. Various additives are added to either the photosensitive layer or the non-photosensitive layer. Regarding them, International Publication WO98 / 36322, European Patent Publication EP803376A1, JP-A-10-18
Reference can be made to JP-A-6567 and JP-A-10-18568.

For the support applicable to the present invention, paragraph No. 0134 of JP-A-11-65021, for the antistatic or conductive layer, paragraph No. 0135 of the same publication, and for the method of obtaining a color image, paragraph No. 0136 of the same publication
It is described in. When the support is transparent, it may be colored with a blue dye (for example, Dye-1 described in Examples of JP-A-8-240877) or may be uncolored. Japanese Patent Application Laid-Open No. H11-84
No. 574, No. 10-186565, and the like. For the antistatic layer or the undercoat, JP-A-56-143430 and JP-A-56-143.
No. 431, No. 58-62646, No. 56-1
The technology disclosed in Japanese Patent Publication No. 20519 can also be applied.

The heat-developable image recording material of the present invention comprises one or more layers on a support. One layer configuration must include optional organic silver salts, developers and binders, and optional additional materials such as silver halide, toning agents, coating aids and other auxiliaries. The two-layer configuration is
The first organic acid silver layer (usually the layer adjacent to the support) must contain the organic acid silver and silver halide and the second layer or both layers must contain some other components. But,
A two-layer configuration comprising a single organic acid silver layer containing all components and a protective topcoat is also contemplated. The construction of a multicolor photothermographic material may include a combination of these two layers for each color, and US Pat. No. 4,708,92.
All components may be contained in a single layer as described in US Pat. In the case of a multi-dye, multi-color photosensitive heat-developable photographic material, each organic acid silver layer generally comprises
The use of a functional or non-functional barrier layer between each organic acid silver layer keeps them distinct from each other, as described in US Pat.

The heat-developable image recording material of the present invention is a so-called single-sided light-sensitive material having at least one light-sensitive layer containing a silver halide emulsion on one side of a support and a back layer on the other side. It is preferred that The heat-developable image recording material of the present invention is preferably of a mono-sheet type (a type capable of forming an image on a photothermographic material without using another sheet such as an image receiving material).

The preparation temperature of the organic acid silver layer coating solution of the present invention is 2
The temperature is preferably from 5 to 65 ° C, more preferably from 30 to 60 ° C, and still more preferably from 30 to 55 ° C. The temperature of the coating solution of the organic acid silver layer immediately after the addition of the polymer latex is preferably maintained at 30 to 65 ° C. Further, it is preferable that the reducing agent and the organic acid silver are mixed before the addition of the polymer latex.

The fluid containing the organic acid silver or the coating solution for the thermal image forming layer in the present invention is preferably a so-called thixotropic fluid. The thixotropic property refers to a property in which the viscosity decreases as the shear rate increases. Although any device may be used for the viscosity measurement of the present invention, an RFS fluid spectrometer manufactured by Rheometrics Far East Co., Ltd. is preferably used, and the viscosity is measured at 25 ° C.
Here, the viscosity at a shear rate of 0.1 S ^-1 is preferably 300 to 100,000 mPa · s, more preferably 400 to 20,000 mPa · s, in the organic acid silver-containing fluid or the coating solution for thermal image forming layer in the present invention. It is. In addition, at a shear rate of 1000 S ⁻¹ , ¹ to 200 mPa
S is preferable, and more preferably 5 to 80 mPa · s.

Various systems exhibiting thixotropic properties are known, and are described in, for example, "Koza Rheology", edited by Kobunshi Kankokai, "Polymer Latex", co-authored by Muroi and Morino (published by Kobunshi Kankokai). In order for a fluid to exhibit thixotropic properties, it is necessary to contain a large amount of solid fine particles. In order to enhance the thixotropic property, it is effective to include a thickened linear polymer, to increase the aspect ratio of the contained solid fine particles in an anisotropic shape, to increase the alkali thickening, and to use a surfactant.

In the preparation of the heat-developable image recording material of the present invention, the coating solution for each layer may be applied by any method.
Specifically, various coatings including extrusion coating, slide coating, curtain coating, dip coating, knife coating, flow coating, or extrusion coating using a hopper of the type described in U.S. Pat. No. 2,681,294. A coating operation was used, and Stephen F. et al. Kis
tler, Peter M.S. "LIQUID FILM COATING" by Schweizer (CHA
PMAN & HALL, 1997) 399-53
Extrusion coating or slide coating described on page 6 is preferably used, and particularly preferably slide coating is used. For examples of slide coater shapes used for slide coating, see Ibid.
Figure 11b. 1. If desired, two or more layers are simultaneously coated by the method described in the same book, pages 399 to 536, the method described in U.S. Pat. No. 2,761,791 and British Patent No. 837,095. be able to. In the present invention, it is preferable that the organic acid silver layer and the outermost protective layer on the side of the organic acid silver layer are simultaneously coated in multiple layers.

The technology that can be used in the heat-developable image recording material of the present invention includes European Patent Publication EP803376.
A1 and JP883022A1, International Publication WO
JP-A-98 / 36322, JP-A-56-62648, JP-A-58-62644, and JP-A-9-28163.
No. 7, No. 9-297367, No. 9-3048
Nos. 69, 9-31405 and 9-329
No. 865, No. 10-10669, No. 10-6
Nos. 2899, 10-69023, 10-
186568, 10-90823, 1
Nos. 0-171063, 10-186565, 10-186567, and 10-18656
Nos. 9 to 10-186572, 10-1979
No. 74, 10-197982, 10-1
No. 97983, No. 10-197985 to No. 10-
197987, 10-207001, 10-207004, 10-221807, 10-282601, 10-28882
No. 3, No. 10-288824, No. 10-30
No. 7365, No. 10-312038, No. 10
-339934, 11-11100, 1
No. 1-15105, No. 11-24200, No. 11-24201, No. 11-30832,
JP-A-11-84574, JP-A-11-65021, JP-A-11-125880, and JP-A-11-12962.
No. 9, JP-A-11-133536 to JP-A-11-13335
Nos. 39, 11-133542 and 11-1
No. 33543 is also cited.

The heat-developable image recording material of the present invention may be developed by any method. Usually, the heat-developable image recording material exposed imagewise is heated and developed. The preferred development temperature is 80 to 250 ° C, more preferably 100 to 140 ° C. The development time is 1 to
180 seconds is preferable, 10 to 90 seconds is more preferable,
Particularly preferred is 10 to 40 seconds.

As a method of thermal development, a plate heater method is preferable. The heat development method using a plate heater method is described in Japanese Patent Application Nos. 9-229684 and 10-17.
No. 7610, preferably a heat developing apparatus for obtaining a visible image by bringing a heat-developable image recording material having a latent image formed thereon into contact with a heating means in a heat developing section, wherein the heating means comprises a plate. A plurality of pressing rollers are provided opposite each other along one surface of the plate heater, and the heat development image recording material is passed between the pressing roller and the plate heater to perform heat development. And a heat developing device. Plate heater 2
It is preferable to lower the temperature of the tip portion by about 1 to 10 ° C. in six stages. Such a method is disclosed in JP-A-54-3
No. 0032, it is also possible to exclude water and organic solvents contained in the heat-developable image recording material out of the system, and that the heat-developable image recording material is rapidly heated. Changes in the shape of the support of the heat-developable image recording material can also be suppressed.

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

The laser light is preferably a single mode laser.
Although it can be used, the paragraph number of JP-A-11-65021
The technique described in No. 0140 can be used. laser
The output is preferably 1 mW or more, and 10 mW
The above ones are more preferable, and those with high output of 40 mW or more
Is more preferred. At that time, multiple lasers are combined.
You may. The diameter of the laser beam is the Gaussian beam
1 / e ^TwoThe spot size should be about 30-200μm
be able to. Laser with exposure unit and heat development unit
Fuji Medical Dry Laser I as an imager
Major FM-DPL can be mentioned.

The heat-developable image recording material of the present invention forms a black-and-white image by a silver image, and is a heat-developable photosensitive material for medical diagnosis.
Photothermographic materials for industrial photography, photothermographic materials for printing, C
It is preferably used as a heat development image recording material for OM. In these uses, based on the formed black-and-white image, a duplicate image is formed on a duplication film MI-Dup manufactured by Fuji Photo Film Co., Ltd. for medical diagnosis, or Fuji Photo Film Co., Ltd. is used for printing. Needless to say, it can be used as a mask for forming an image on a return film DO-175, PDO-100 or offset printing plate manufactured by the Company.

[0107]

The present invention will be described more specifically with reference to the following examples. Materials, reagents, ratios, operations, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.

Example 1 << Polyethylene terephthalate having an undercoat layer (PE
T) Preparation of Support >> (1) Preparation of PET Support According to a conventional method using terephthalic acid and ethylene glycol, the intrinsic viscosity IV = 0.66 (phenol / tetrachloroethane = 6/4 (weight) Ratio (measured at 25 ° C.) in polyethylene terephthalate (PET). After pelletizing this, it is dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die and quenched to produce an unstretched film having a thickness of 175 μm after heat setting. did. This was performed at 110 ° C. using rolls having different peripheral speeds.
The film was longitudinally stretched three times and then transversely stretched 4.5 times at 130 ° C. using a tenter. Thereafter, after heat-setting at 240 ° C. for 20 seconds, it was relaxed by 4% in the lateral direction at the same temperature. Then, after slitting the chuck portion of the tenter, knurling is performed on both ends, the film is wound at 4.8 kg / cm ² , and the thickness is 175 mm.
A μm-roll PET support was obtained.

(2) Surface Corona Treatment Both surfaces of the PET support obtained in the above (1) were treated at room temperature at 20 m / min using a solid state corona treatment machine 6KVA model manufactured by Pillar Co., Ltd. The current at this time,
From the voltage reading, the support showed 0.375 kV · A
-It turned out that processing of minute / m < ² > was performed. The processing frequency at this time was 9.6 kHz, and the gap clearance between the electrode and the dielectric roll was 1.6 mm.

(3) Preparation of Undercoat Layer Coating Solution (Formulation 1) For undercoat layer on the side of organic acid silver layer Pesresin A-515GB (30% by weight solution) manufactured by Takamatsu Oil & Fat Co., Ltd. 234 g polyethylene glycol monononyl phenyl ether (average) Ethylene oxide number = 8.5) 10 wt% solution 21.5 g Soken Chemical Co., Ltd. MP-1000 (polymer fine particles, average particle diameter 0.4 μm) 0.91 g distilled water 744 ml

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

(Formulation 3) SnO ₂ / SbO for back surface side second layer (9/1 weight ratio, average particle size 0.038 μm, 17% by weight dispersion) 168 g Gelatin (10% aqueous solution) 89.2 g Shin-Etsu Chemical 8.6 g Metrolose TC-5 (2% aqueous solution) manufactured by Soken Chemical Co., Ltd. MP-1000 (polymer fine particles) 0.01 g 1 wt% aqueous solution of sodium dodecylbenzenesulfonate 10 ml NaOH (1%) 6 ml Proxel (Made by ICI) 1ml distilled water 721ml

(4) Preparation of PET support having undercoat layer On one side of the PET support subjected to corona discharge obtained in (2) above, the undercoat layer coating liquid formulation 1 obtained in (3) was applied. It was applied with a wire bar so that the wet application amount was 6.6 ml / m ² , and dried at 180 ° C. for 5 minutes. Next, the undercoat layer coating liquid formulation 2 was applied to the back surface (back surface) with a wire bar so that the wet coating amount was 5.7 ml / m ² , and dried at 180 ° C. for 5 minutes. On the back surface, the undercoating coating liquid formulation 3 was coated with a wire bar so that the wet coating amount was 7.7 ml / m ² , and 180
After drying at 6 ° C. for 6 minutes, a PET support having an undercoat layer was prepared.

<< Preparation of Back Surface Coating Solution >> (1) Preparation of Anti-Halation Layer Coating Solution (1-1) Preparation of Solid Fine Particle Dispersion Solution of Base Precursor 64 g of base precursor compound 11, 28 g of diphenyl sulfone, and Kao ( Surfactant Demol N (10 g) was mixed with 220 ml of distilled water, and the mixture was dispersed in beads using a sand mill (1/4 Gallon sand grinder mill, manufactured by Imex Co., Ltd.) to have an average particle diameter of 0.2 μm. The solid precursor dispersion liquid of the base precursor was obtained.

(1-2) Preparation of Dye Solid Fine Particle Dispersion A solution of 9.6 g of cyanine dye compound 13 and 5.8 g of sodium P-dodecylbenzenesulfonate in distilled water 30 was prepared.
5 ml and mix the mixture with a sand mill (1 / 4Gall
on sand grinder mill, manufactured by Imex Co., Ltd.)
To obtain a dispersion of solid dye fine particles having an average particle diameter of 0.2 μm.

(1-3) Preparation of Coating Solution for Antihalation Layer: 17 g of gelatin, 9.6 g of polyacrylamide, and a solid fine particle dispersion 70 of the base precursor obtained in the above (1)
g, 56 g of the dye solid fine particle dispersion obtained in (2) above, and polymethyl methacrylate fine particles (average particle size of 6.5).
μm) 1.5 g, benzoisothiazolinone 0.03 g,
2.2 g of sodium polyethylene sulfonate, 0.2 g of blue dye compound 14 and 844 ml of water were mixed to prepare a coating solution for an antihalation layer.

(2) Preparation of Coating Solution for Back Surface Protective Layer (2-1) Preparation of Coating Solution 1 for Back Surface Protective Layer A container was kept warm at 40 ° C., gelatin 50 g, sodium polystyrene sulfonate 0.2 g, N , N-ethylenebis (vinylsulfoneacetamide) 2.4 g, tert-
Sodium octylphenoxyethoxyethanesulfonate 1 g, benzoisothiazolinone 30 mg, N-perfluorooctylsulfonyl-N-propylalanine potassium salt 37 mg, polyethylene glycol mono (N-
Perfluorooctylsulfonyl-N-propyl-2-
Aminoethyl) ether [ethylene oxide average polymerization degree 15] 0.15 g, the _{C 8 F 17 SO 3 K 32mg} , C 8
_{F 1 7 SO 2 N (C} 3 H 7) (CH 2 CH 2 O) 4 (CH 2) 4 -
64 mg of SO ₃ Na, 8.8 g of an acrylic acid / ethyl acrylate copolymer (copolymerization weight ratio 5/95) as a polymer latex, 0.6 g of aerosol OT (manufactured by American Cyanamid Co.), liquid paraffin emulsion Was mixed with 1.8 g of liquid paraffin and 950 ml of water to obtain a back surface protective layer coating solution 1.

(2-2) Preparation of Coating Solution 2 for Back Surface Surface Protective Layer Polyvinyl alcohol PVA-235 (Kuraray Co., Ltd.)
G) of a 5% by weight aqueous solution of methyl methacrylate / styrene / 2-ethylhexyl methacrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymerization weight ratio 59/9/25/5/2, particle size 70n)
m, glass transition temperature 57 ° C) 22% by weight latex liquid 4
91 g, N-perfluorooctylsulfonyl-N-
6 ml of a 5% by weight solution of propylalanine potassium salt,
2% by weight of polyethylene glycol mono (N-perfluorooctylsulfonyl-N-propyl-2-aminoethyl) ether [average degree of polymerization of ethylene oxide = 15]
32 ml of an aqueous solution, 6 ml of a 5% by weight aqueous solution of aerosol OT (manufactured by American Cyanamid), 6.1 g of a 10% by weight aqueous dispersion of carnauba wax, and water were added so that the total amount was 1160 g. A back surface protective layer coating solution 2 was obtained.

(2-3) Preparation of Coating Solution 3 for Back Surface Surface Protective Layer In the above (2-2), polyvinyl alcohol PVA was used.
-235 instead of hydroxypropylcellulose L
A back surface protective layer coating solution 3 was obtained in the same manner except that (Nippon Soda Co., Ltd.) (240 g of a 5% by weight aqueous solution) was used.

<Preparation of Organic Acid Silver Layer Coating Solutions 1 and 2><Preparation of Silver Halide Mixed Emulsion> (1) Preparation of Silver Halide Emulsion 1 Distilled water 142 was placed in a titanium-coated stainless steel reaction pot.
1 ml, 8.0 ml of a 1% by weight potassium bromide solution, 8.2 ml of 1N nitric acid and 20 g of phthalated gelatin were added,
While stirring, the liquid temperature was maintained at 37 ° C. Silver nitrate 37.0
A solution A in which 4 g was diluted to 159 ml with distilled water and a solution B in which 32.6 g of potassium bromide was diluted to 200 ml with distilled water were prepared. PA by control double jet method
The total amount of solution A was added at a constant flow rate over 1 minute while maintaining g at 8.1. Solution B was added by a controlled double jet method. Thereafter, 30 ml of a 3.5% by weight aqueous hydrogen peroxide solution was added, and 36 ml of a 3% by weight aqueous solution of benzimidazole were further added. Thereafter, the solution A2 was again diluted with distilled water to 317.5 ml.
And 1 × 10 ⁻⁴ mol of 6 per mol of silver with respect to solution B
Dissolve the tri-potassium iridium chloride salt and add 40 ml of distilled water.
Using the solution B2 diluted to 0 ml, the entire amount of the solution A2 was added at a constant flow rate over 10 minutes by a controlled double jet method while maintaining the pAg at 8.1. Solution B2 was added by a controlled double jet method. Thereafter, 50 ml of a 0.5% by weight methanol solution of 5-methyl-2-mercaptobenzimidazole was added, the pAg was further increased to 7.5 with silver nitrate, and the pH was adjusted to 3.8 with 1N sulfuric acid. Stop stirring, perform sedimentation / desalting / washing steps, add 3.5 g of deionized gelatin, add 1N
PH 6.0, pAg
Prepared at 8.2 to obtain a silver halide dispersion.

The grains in the obtained silver halide dispersion were:
Average sphere equivalent diameter 0.053 μm, sphere equivalent diameter variation coefficient 18
% Pure silver bromide particles. The particle size and the like were determined from the average of 1000 particles using an electron microscope. The [100] plane ratio of these particles was 85% by the Kubelka-Munk method. The above dispersion was stirred at 38 ° C., and 0.035 g of benzoisothiazolinone (added with a 3.5% by weight methanol solution) was added. After 40 minutes, a solid dispersion of the spectral sensitizing dye A (aqueous gelatin solution) Is 5 × 10
^-3 mols, the temperature was raised to 47 ° C. After 1 min, 3 × sodium benzenethiosulfonate per mole of silver after 20 minutes
10 ^-5 mol was added, and two minutes later, tellurium sensitizer B was added with silver 1
5 × 10 ⁻⁵ mol per mol was added and the mixture was aged for 90 minutes. Immediately before the completion of ripening, 5 ml of a 0.5% by weight methanol solution of N, N′-dihydroxy-N ″ -diethylmelamine was added, the temperature was lowered to 31 ° C., and phenoxyethanol was added.
5 ml of a 5% by weight methanol solution and 5-methyl-2-mercaptobenzimidazole were added in an amount of 7 × 10 ⁻³ per mol of silver.
Mol and 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole were added in an amount of 6.4 × 10 ⁻³ mol per mol of silver to prepare a silver halide emulsion 1.

(2) Preparation of silver halide emulsion 2 In the preparation of silver halide emulsion 1 in the above (1), except that the liquid temperature at the time of grain formation was changed from 37 ° C to 50 ° C, an average sphere equivalent was prepared. A pure silver bromide cubic grain emulsion having a diameter of 0.08 μm and a coefficient of variation in equivalent sphere diameter of 15% was prepared. Precipitation / desalting / water washing / dispersion was performed in the same manner as (1). Further, a silver halide emulsion 2 was prepared in the same manner as in (1) except that the amount of the spectral sensitizing dye A was changed to 4.5 × 10 ^-3 mol per mol of silver.

(3) Preparation of silver halide emulsion 3 In the preparation of silver halide emulsion 1 in the above (1), except that the liquid temperature 37 ° C. during grain formation was changed to 27 ° C. A pure silver bromide cubic grain emulsion having a diameter of 0.038 μm and a coefficient of variation in sphere equivalent diameter of 20% was prepared. (1)
Precipitation / desalting / water washing / dispersion was carried out in the same manner as described above. Further, silver halide emulsion 3 was prepared in the same manner as in (1) except that the amount of spectral sensitizing dye A was changed to 6 × 10 ^-3 mol per mol of silver.
Was prepared.

(4) Preparation of a mixed silver halide emulsion The silver halide emulsion 1 obtained in the above (1) to (3) was prepared by mixing 70
% Of the silver halide emulsion 2 and 15% by weight of the silver halide emulsion 3 were mixed at a ratio of 7 × 1 per mole of silver with a 1% by weight aqueous solution of benzothiazolium iodide.
0 ^-3 mole was added to prepare a mixed emulsion.

<Preparation of Organic Acid Silver Dispersion> Behenic acid manufactured by Henkel (product name: Edenor C22-85R) 87.6.
g, distilled water 423 ml, 5N-NaOH aqueous solution 49.2
and tert-butanol (120 ml).
The reaction was carried out by stirring at 1 ° C. for 1 hour to obtain a sodium behenate solution. Separately, 206.2 m of an aqueous solution of 40.4 g of silver nitrate
1 (pH 4.0) was prepared and kept at 10 ° C. Distilled water 6
The reaction vessel containing 35 ml and 30 ml of tert-butanol was kept at 30 ° C., and the total amount of the sodium behenate solution and the total amount of the silver nitrate aqueous solution were maintained at a constant flow rate while stirring.
The addition was performed over 62 minutes, 10 seconds and 60 minutes, respectively. At this time, only the aqueous solution of silver nitrate was added for 7 minutes and 20 seconds after the addition of the aqueous solution of silver nitrate, and then the addition of the sodium behenate solution was started. Was added. At this time, the temperature inside the reaction vessel was 30 ° C.
The external temperature was controlled so that the liquid temperature became constant. The piping of the addition system of the sodium behenate solution was kept warm by steam tracing, and the steam opening was adjusted so that the liquid temperature at the outlet at the tip of the addition nozzle became 75 ° C. The piping of the silver nitrate aqueous solution addition system was kept warm by circulating cold water outside the double pipe. The addition position of the sodium behenate solution and the addition position of the aqueous silver nitrate solution were arranged symmetrically with respect to the stirring axis, and were adjusted to a height such that they did not come into contact with the reaction solution.

After the completion of the addition of the sodium behenate solution, the mixture was allowed to stir at the same temperature for 20 minutes, and the temperature was lowered to 25 ° C. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtered water became 30 μS / cm. Thus, an organic acid silver 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 microscopic photographing, a = 0.14 μm, b = 0.4 μm, and c = 0.6 in average.
μm, average aspect ratio 5.2, average sphere equivalent diameter 0.52
It was a scaly crystal having a diameter of μm and a coefficient of variation of the equivalent sphere diameter of 15%. (A, b, c are defined in the text)

A wet cake having a dry solid content of 100 g was added to polyvinyl alcohol (trade name: PVA-21).
7) 7.4 g and water were added to make the total amount 385 g, which was pre-dispersed with a homomixer. Subsequently, the pre-dispersion liquid was dispersed in a dispersing machine (trade name: Microfluidizer M-1).
The pressure of 10S-EH, manufactured by Microfluidics International Corporation, using a G10Z interaction chamber) was adjusted to 1750 kg / cm ² , and the mixture was treated three times to prepare a dispersion of silver organic acid (silver behenate). In the cooling operation, a coiled heat exchanger was mounted before and after the interaction chamber, and the dispersion temperature was set at 18 ° C. by adjusting the temperature of the refrigerant.

<Preparation of 25% by weight dispersion of reducing agent>
10 kg of 1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane, modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., Poval MP)
203) 10 kg of a 20% by weight aqueous solution and 16 kg of water
Was mixed well to form a slurry. This slurry was sent by a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 3 hours and 30 minutes, and then sodium benzoisothiazolinone sodium salt 0 By adding 0.2 g and water, the concentration of the reducing agent was adjusted to 25% by weight to obtain a 25% by weight dispersion of the reducing agent. The reducing agent particles in the dispersion had a median diameter of 0.42 μm and a maximum particle diameter of 2.0 μm or less. The obtained reducing agent dispersion was filtered through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust, and stored.

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

<Preparation of Organic Polyhalogen Compound Dispersion 1> 5 kg of tribromomethylnaphthyl sulfone, modified polyvinyl alcohol (Poval MP20 manufactured by Kuraray Co., Ltd.)
2.5 kg of a 20% by weight aqueous solution of 3) and a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate 2
13 g and 10 kg of water were mixed well to form a slurry. The slurry was fed by a diaphragm pump and dispersed for 5 hours by a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm.
2 g and water were added to adjust the concentration of the organic polyhalogen compound to 20% by weight to obtain Organic Polyhalogen Compound Dispersion 1. The organic polyhalogen compound particles in the dispersion had a median diameter of 0.36 μm and a maximum particle diameter of 2.0 μm.
m or less. The obtained organic polyhalogen compound dispersion 1 was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<Preparation of Organic Polyhalogen Compound Dispersion 2> In the preparation of the organic polyhalogen compound dispersion 1, tribromomethyl (4- (2,4,6-trimethyl) was used instead of 5 kg of tribromomethylnaphthyl sulfone. 5 kg of phenylsulfonyl) phenyl) sulfone was similarly dispersed, and the organic polyhalogen compound was adjusted to 25% by weight to obtain an organic polyhalogen compound dispersion 2. The organic polyhalogen compound particles in the dispersion had a median diameter of 0.38 μm and a maximum particle diameter of 2.0 μm or less. Obtained organic polyhalogen compound dispersion 2
Was filtered and stored in the same manner as in the above organic polyhalogen compound dispersion 1.

<Preparation of Organic Polyhalogen Compound Dispersion 3> In the preparation of the above organic polyhalogen compound dispersion 1, 5 kg of tribromomethylphenylsulfone was used in place of 5 kg of tribromomethylnaphthylsulfone.
The dispersion was carried out in the same manner except that the amount of the 0% by weight MP203 aqueous solution was changed to 5 kg.
Thus, an organic polyhalogen compound dispersion 3 was obtained. Organic polyhalogen compound particles in the dispersion,
The median diameter was 0.41 μm and the maximum particle diameter was 2.0 μm or less. The resulting organic polyhalogen compound dispersion 3 is
Filtration was carried out in the same manner as in the above-mentioned organic polyhalogen compound dispersion 1, and stored. After storage, it was stored at 10 ° C. or lower until use.

<Preparation of 5% by weight solution of phthalazine compound> 8 kg of denatured polyvinyl alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.) was dissolved in 174.57 kg of water, and then a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate. 15 kg and 14.28 kg of a 70% by weight aqueous solution of 6-isopropylphthalazine were added to prepare a 5% by weight solution of 6-isopropylphthalazine.

<Preparation of 20% by weight dispersion of pigment>
I. Pigment Blue 60, 6.4 g of Demol N manufactured by Kao Corporation, and 250 g of water were mixed well to form a slurry. This slurry was put in a vessel together with 800 g of zirconia beads having an average diameter of 0.5 mm in a vessel, and a disperser (１ ／ G sand grinder mill:
Disperse for 25 hours with IMEX Co., Ltd.
A weight percent dispersion was prepared. The pigment particles in the obtained dispersion had an average particle size of 0.21 μm.

<Preparation of 40% by weight aqueous solution of SBR latex 1> The following SBR latex diluted 10 times with distilled water was subjected to ultrafiltration (UF) purification module FS.
03-FC-FUY03A1 (Daisen Membrane
Ion conductivity of 1.5 mS /
cm, and Sandet-BL manufactured by Sanyo Kasei Co., Ltd. was added to a concentration of 0.22% by weight. Further with NaOH and NH ₄ OH Na ⁺ ion: NH ₄ ⁺ ion = 1: 2.3 was added to a (molar ratio), pH
Adjusting to 8.4, a 40% by weight aqueous solution of SBR latex 1 was prepared. (SBR latex: -St (68) -Bu (29)-
AA (3) -latex) Equilibrium water content at an average particle size of 0.1 μm, a concentration of 45%, and a relative humidity of 60% at 25 ° C. and 60%.
6% by weight, ion conductivity 4.2 mS / cm (Ion conductivity is measured by a conductivity meter CM-30S manufactured by Toa Denpa Kogyo Co., Ltd.)
Using a latex stock solution (40%) measured at 25 ° C.), pH 8.2

<Preparation of 40% by weight aqueous solution of SBR latex 2> Purification of UF was carried out in the same manner as in the preparation of the above 40% by weight aqueous solution of SBR latex 1 to reduce Sandet-BL manufactured by Sanyo Chemical Co., Ltd. to 0.22% by weight. The SBR latex 2 was used as it was as a 40% by weight aqueous solution of SBR latex 2. pH was 7.2.

<Preparation of Organic Acid Silver Layer Coating Solution 1> 10 g of the silver halide mixed emulsion and the organic acid silver dispersion 10 obtained above were obtained.
A mixture obtained by mixing 3 g, 25 g of a 25% dispersion of a reducing agent, 6.2 g of a 10 wt% dispersion of a mercapto compound, and organic polyhalogen compound dispersions 1, 2 and 3 at a weight ratio of 15: 1: 3. 16.3 g, 18 ml of a 5% by weight solution of a phthalazine compound, 1.1 g of a 20% by weight dispersion of a pigment,
106 g of a 40% by weight aqueous solution of SBR latex 1 and polyvinyl alcohol PVA-205 (Kuraray Co., Ltd.)
5g of a 20% by weight aqueous solution of the organic acid silver layer was prepared, and a coating liquid 1 for the organic acid silver layer was prepared.
The solution was sent to 1 / m ² .

The viscosity of the obtained coating liquid 1 for an organic acid silver layer was 85 mPa · s at 40 ° C. (No. 1 rotor, 60 rpm) as measured by a B-type viscometer of Tokyo Keiki. Also, RFS manufactured by Rheometrics Far East Co., Ltd.
The viscosity of the organic acid silver layer coating solution 1 at 25 ° C. using a fluid spectrometer is such that the shear rate is 0.1, 1, 1
1 each at 0, 100, and 1000 [1 / sec]
500, 220, 70, 40, and 20 [mPa · s].

<Preparation of Organic Acid Silver Layer Coating Solution 2> In the preparation of the organic acid silver layer coating solution 1, a 40 wt% aqueous solution of the SBR latex 1 was used instead of the 40 wt% aqueous solution of the SBR latex 1.
Using a 10% by weight aqueous solution (106 g) instead of a 5% by weight solution of the phthalazine compound,
A coating solution 2 of the organic acid silver layer was prepared in the same manner except that 16 ml of the methanol solution was used, and the solution was directly sent to the coating die at 70 ml / m ² .

<< Preparation of Coating Solution for Intermediate Layer on the Organic Acid Silver Layer Side >> 772 g of a 10% by weight aqueous solution of polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.), 5.3 g of a 20% by weight dispersion of pigment, methyl methacrylate / styrene / Butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymerization weight ratio 64/9/20/5/2)
226 g of latex 27.5% by weight liquid, Aerosol O
5% by weight aqueous solution of T (manufactured by American Cyanamid) 2
ml, 20% by weight aqueous solution of diammonium phthalate 1
0.5 ml and water were added to make a total amount of 880 g, and a coating solution for the intermediate layer was prepared and sent to the coating die so as to be 10 ml / m ² . The viscosity of the coating solution for the intermediate layer was determined to be 21 by a B-type viscometer at 40 ° C. (No. 1 rotor, 60 rpm).
[MPa · s].

<< Preparation of Coating Solution 1 for Organic Acid Silver Layer Side Surface Protective Layer >> Inert gelatin (64 g) was dissolved in water, and methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer weight ratio: 64) / 9/20/5/2, glass transition temperature 58
C) 116 g of latex 19% by weight liquid, 10% of phthalic acid
23 ml of a methanol solution by weight, 23 ml of a 10% by weight aqueous solution of 4-methylphthalic acid, 28 ml of 1N sulfuric acid, 5% by weight of aerosol OT (manufactured by American Cyanamid)
An aqueous solution (5 ml), phenoxyethanol (0.5 g), benzoisothiazolinone (0.1 g) and water were added to make a total amount of 7%.
The surface protective layer coating solution 1 was prepared at 50 g. Immediately before coating, 26 ml of 4% by weight chromium alum was mixed with a static mixer, and the mixture was fed to a coating die at 18.6 ml / m ² . The viscosity of the surface protective layer coating solution 1 was measured using a B-type viscometer at 40 ° C. (No. 1 rotor, 60 rpm).
m) was 17 [mPa · s].

<< Preparation of Coating Solution 2 for Organic Acid Silver Layer-Side Surface Protective Layer >> 1200 g of a 10% by weight aqueous solution of polyvinyl alcohol PVA-217 (manufactured by Kuraray Co., Ltd.), potassium N-perfluorooctylsulfonyl-N-propylalanine salt 6 ml of a 5% by weight solution, 32 ml of a 2% by weight aqueous solution of polyethylene glycol mono (N-perfluorooctylsulfonyl-N-propyl-2-aminoethyl) ether [average degree of polymerization of ethylene oxide = 15], Aerosol OT (American Siana) 5% by weight
6 ml of an aqueous solution, 52 ml of a 16.6 g / vol% methanol solution of phthalic acid, 1.6 g of polymethyl methacrylate fine particles (particle size: 5.0 μm), 6.1 g of a 10% by weight aqueous dispersion of carnauba wax, and water were added to the total amount. 1350
g, prepare a surface protective layer coating solution 2 and add 33 ml / m
^The solution was fed to the coating die so as to be ² . The viscosity of the surface protective layer coating solution 2 was 108 [mPa · s] using a B-type viscometer at 40 ° C. (No. 2 rotor, 60 rpm).

<< Preparation of Coating Solution 3 for Organic Acid Silver Layer Side Surface Protective Layer >> In the preparation of the coating liquid 2 for organic acid silver layer side surface protective layer, polyvinyl alcohol PVA-235 (Kuraray) was used instead of polyvinyl alcohol PVA-217. (stock)
Using a 960 g of a 5% by weight aqueous solution of methacrylate / styrene / 2-ethylhexyl methacrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymerization weight ratio 59/9/25/5/2, particle size 70 nm, Glass transition temperature 57 ° C) Latex 2
330 g of a 2% by weight liquid was added, and water was added to make the total amount 1400.
A surface protective layer coating solution 3 was prepared in the same manner except that the amount was changed to g, and fed to a coating die at 34 ml / m ² . The viscosity of the surface protective layer coating solution 3 is measured using a B-type viscometer 40.
96 [mPa ·] at ℃ (No. 2 rotor, 60 rpm)
s].

<< Preparation of Coating Solution 4 for Organic Acid Silver Layer Side Surface Protective Layer >> In the preparation of the coating solution 3 for organic acid silver layer side, 5% by weight of polyvinyl alcohol PVA-235 was used.
A surface protective layer coating solution 4 was prepared in the same manner except that the amount of the aqueous solution was 720 g, the amount of the latex 22% by weight solution was 382 g, and water was added to make the total amount 1230 g.
The solution was fed to the coating die so as to be 0 ml / m ² . The viscosity of the surface protective layer coating solution 4 is a B-type viscometer of 40 ° C.
(No. 2 rotor, 60 rpm) at 125 [mPa
s].

<< Preparation of Coating Solutions 5 to 7 for Organic Acid Silver Layer Side Surface Protection Layer >> In the preparation of the coating solution 3 for the organic acid silver layer side surface protection layer, the ratio of polyvinyl alcohol / latex was changed to 2
Similarly, except that / 8, 1/9 and 5/95 were used.
Coating solutions 5, 6, and 7 for the surface protective layer were respectively prepared and provided for coating. The viscosities of the surface protective layer coating liquids 5 to 7 were 140, 159 and 72 [mPa · s], respectively, with a B-type viscometer at 40 ° C. (No. 2 rotor, 60 rpm).

<< Preparation of Coating Solution 8 for Organic Acid Silver Layer Side Surface Protective Layer >> In the preparation of the above coating liquid 3 for organic acid silver layer side surface protective layer, 5% by weight of polyvinyl alcohol PVA-235 was used.
The amount of the aqueous solution was 240 g, and methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer weight ratio 64/9/20/5/2, glass transition temperature 58 ° C.) as polymer latex 19 Using 570 g of a weight% liquid,
Same as above except that water was added to make the total amount 1160 g.
A surface protective layer coating solution 8 was prepared and sent to a coating die at a concentration of 28 ml / m ² . Surface protective layer coating solution 8
Is 40 ° C. using a B-type viscometer (No. 2 rotor, 60
rpm) was 125 [mPa · s].

<< Coating Solutions for Organic Acid Silver Layer Side Surface Protection Layer 9-13 >>
Preparation >> In the above-mentioned preparation of the organic acid silver layer side surface protective layer coating solution 8, each of latex and surface protective layer coating solution 9: ethyl acrylate / acrylic acid copolymer (copolymer weight ratio 99/1, glass transition Temperature-2
8 ° C) 540 g of latex 20% by weight liquid; Surface protective layer coating liquid 10: methyl methacrylate / 2-ethylhexyl acrylate / acrylic acid copolymer (copolymer weight ratio 55/40/5, glass transition temperature 23 ° C) 20 weight of latex % Liquid: 540 g; surface protective layer coating liquid 11: methyl methacrylate / ethyl acrylate / acrylic acid copolymer (copolymerization weight ratio: 60
/ 35/5, glass transition temperature 45 ° C.) 540 g of latex 20% by weight solution; coating solution for surface protective layer 12: methyl methacrylate / ethyl acrylate / acrylic acid copolymer (copolymer weight ratio 75)
/ 20/5, glass transition temperature 70 ° C) 540 g of latex 20% by weight liquid; and surface protective layer coating liquid 13: methyl methacrylate / acrylic acid copolymer (copolymer weight ratio 95/5, glass transition temperature 105 ° C) latex In the same manner except that 540 g of a 20% by weight liquid was used, surface protective layer coating liquids 9 to 13 were prepared.
The solution was sent in the same manner.

<< Preparation of Organic Acid Silver Layer-Side Surface Protective Layer Coating Solution 14 >> In the preparation of the organic acid silver layer-side surface protective layer coating solution 3, hydroxypropyl cellulose L (Nippon Soda Co., Ltd.) was used instead of polyvinyl alcohol. Co., Ltd. was prepared in the same manner except that 240 g of a 5% by weight aqueous solution of
The solution was fed to the coating die so as to be 8 ml / m ² .

<< Preparation of Coating Solution 15 for Organic Acid Silver Layer Side Surface Protective Layer >> In the preparation of the above coating solution 14 for organic acid silver layer side surface protective layer, instead of the phthalic acid 16.6 g / vol.% Methanol solution, 20 g / vol% of diammonium phthalate
A surface protective layer coating solution 15 was prepared in the same manner except that an aqueous solution (52 ml) was used, and was sent in the same manner.

<< Preparation of Coating Solution for Second Layer of Surface Protective Layer on Organic Acid Silver Layer >> 80 g of inert gelatin was dissolved in water, and methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer weight) was used. Ratio 64/9/20/5/2) latex 27.5
102 g of a 5% by weight solution, 3.2 ml of a 5% by weight solution of potassium N-perfluorooctylsulfonyl-N-propylalanine, polyethylene glycol mono (N-perfluorooctylsulfonyl-N-propyl-2-aminoethyl) ether [ethylene oxide Average degree of polymerization = 1
32] of a 2% by weight aqueous solution of 5], 23 ml of a 5% by weight solution of aerosol OT (manufactured by American Cyanamid),
Polymethyl methacrylate fine particles (average particle size 0.7μ
m) 4 g, 21 g of polymethyl methacrylate fine particles (average particle size: 6.4 μm), 1.6 g of 4-methylphthalic acid, 4.8 g of phthalic acid, 44 ml of 1N sulfuric acid, 10 mg of benzoisothiazolinone, and water to add a total amount of 650 g Chromium alum 4% by weight and phthalic acid 0.67
Immediately before coating, 445 ml of an aqueous solution containing 4% by weight was mixed with a static mixer to prepare a coating solution for the second layer of the surface protective layer, and the solution was fed to a coating die at 8.3 ml / m ² . The viscosity of the coating solution for the second layer of the surface protective layer was 9 m with a B-type viscometer at 40 ° C. (No. 1 rotor, 60 rpm).
Pa · s].

<< Preparation of heat-developable image recording material >>
On the back side of the PET support having the undercoat layer
The antihalation layer coating solution prepared in
0.04 g / m solid coating amount ^TwoSo that
And the back surface protective layer coating solution shown in Table 1 as a binder
The application amount is 1.7 g / m^TwoAt the same time so that
After drying, an antihalation back layer was prepared. Bag
As shown in Table 1, the organic acid
Silver layer coating solution (silver halide coated silver amount 0.14 g /
m^Two), Organic acid silver layer side intermediate layer coating solution, organic acid silver layer side surface
Coating solution for protective layer second layer, organic acid silver layer side surface protective layer coating solution
, In this order, using the slide bead coating method
Cloth was applied to prepare heat-developable image recording materials 101 to 121.

The coating was performed at a speed of 160 m / min, and the distance between the tip of the coating die and the support was 0.14 to 0.2.
The width of the application liquid was adjusted to be 8 mm, and the width of the application liquid was widened by 0.5 mm on both the left and right sides with respect to the width of the slit of the application liquid. that time,
The handling and the temperature and humidity were controlled so that the support was not charged, and the charge was removed by ion wind just before coating. In the subsequent chilling zone, a dry-bulb temperature of 18 ° C. and a wet-bulb temperature of 12 ° C. were blown for 30 seconds to cool the coating solution.
Dry-bulb-type drying zone with a dry-bulb temperature of 30
℃, wet bulb temperature is blown dry air of 18 ℃ for 200 seconds,
Subsequently, after passing through a drying zone of 70 ° C. for 20 seconds, 90 ° C.
Was passed through the drying zone for 10 seconds, and then cooled to 25 ° C. to evaporate the solvent in the coating solution. The average wind speed of the wind blowing on the coating liquid film surface in the chilling zone and the drying zone was 7 m / sec. The structure of the compound used in this example is shown below.

[0153]

Embedded image

<< Evaluation >> (1) Surface state The surface states of the heat-developable image recording materials 101 to 121 produced above were observed. Among them, the recording material 107 having a water-soluble polymer / polymer latex ratio of 5/95.
Had cracks and poor surface condition. The surface condition of the other recording materials was good. If the ratio of the polymer latex is too high, drying of the surface proceeds, and it can be seen that a uniform film cannot be formed. (2) Photographic properties The heat-developable image recording materials 101 to 121 were used with Fuji Medical Dry Laser Imager FM-DPL (maximum 60 m).
Exposure and thermal development (approximately 120 ° C.) with a W (IIIB) output 660 nm semiconductor laser). Recording material 1 with poor surface condition
With the exception of 07, Dmin was low and good photographic performance was exhibited.

(3) Water Resistance For the heat-developable image recording materials 101 to 121, water was dropped before and after the heat development, and the thickness after one minute was measured. The measurement was performed at 25 ° C., and after the heat development, water was dropped on the maximum density portion of the recording material. The increase in thickness due to water was taken as the swelling amount, and the results are shown in Table 1. After the heat development, 0.02 ml of water was applied to the surface of the recording material. One minute later, the surface of the recording material was gently wiped off with a tissue paper and dried, and the damage on the film surface was visually evaluated in five steps. Table 1 shows the results.
5: No traces 4: Slight traces 3: Scratch on film but hardly noticeable by transmitted light 2: Clear scratch on film 1: Film peeling

It was confirmed that the heat-developable image recording material of the present invention had a reduced amount of swelling due to heat development, improved water resistance, and was excellent in handleability of a sample after image formation.

(4) Blocking resistance The heat-developable image recording materials 101 to 121 were cut into two pieces of 3.5 cm square at the maximum density and conditioned at 25 ° C. and 80% relative humidity for 2 hours. And so that the back surface is aligned, put a weight of 500g and 5
It was left at 0 ° C. for 24 hours. Thereafter, the recording material was peeled off, and the blocking property was evaluated. Table 1 shows the results. 5: Peeling without blocking marks 4: Peeling although there is gloss unevenness due to blocking 3: Peeling failure of unevenness due to blocking 2: Destruction of film slightly when peeled 1: Film It came off.

It can be seen that even when a water-soluble polymer and a polymer latex are used in combination, blocking failure occurs when the latex has a low glass transition temperature, whereas the heat-developable image recording material of the present invention hardly causes blocking.

[0159]

[Table 1]

[0160]

The heat-developable image recording material of the present invention has good photographic properties and surface properties, good film physical properties such as water resistance and blocking resistance, and is excellent in image handling. In addition, the heat-developable image recording material of the present invention can be obtained by a simple process in a production process having little adverse effect on the environment.

Claims (7)

[Claims] A heat-developable image recording material having at least one non-photosensitive organic silver salt on one side of a support, at least one organic silver layer containing a reducing agent for the organic silver salt and a binder. An outermost protection containing a polymer latex having a glass transition temperature of 20 ° C. or more and less than 70 ° C. on at least one side of the organic acid silver layer-coated surface or the opposite side of the organic acid silver layer-coated surface and the support. A heat-developable image recording material comprising a layer, wherein the outermost protective layer becomes a water-resistant protective layer simultaneously with thermal development. 2. The heat-developable image recording material according to claim 1, wherein the outermost protective layer contains a water-soluble polymer and a polymer latex. 3. The heat-developable image recording material according to claim 2, wherein the polymer latex is contained in an amount of 65 to 94% by weight based on the total binder amount of the outermost protective layer. 4. A heat-developable image recording material comprising at least one non-photosensitive organic silver salt on one side of a support, at least one organic silver layer containing a reducing agent for the organic silver salt and a binder. An outermost protective layer containing a water-soluble polymer and a polymer latex on at least one surface of the organic acid silver layer-coated side or at least one side opposite to the organic acid silver layer-coated surface and the support; Is 65 to 94% by weight based on the total binder amount of the outermost protective layer. 5. The heat-developable image recording material according to claim 4, wherein the glass transition temperature of the polymer latex is 20 ° C. or more and less than 70 ° C. 6. The surface on which the outermost protective layer is formed,
2. The method according to claim 1, wherein the organic acid silver-coated surface is on the side coated with the organic acid silver.
6. The heat-developable image recording material according to any one of items 1 to 5, 7. The heat-developable image recording material according to claim 6, wherein the heat-developable image recording material is formed by simultaneously coating the organic acid silver layer and the outermost protective layer.