JP2006231242A - Application method of undercoat of silver halide photosensitive material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an application method of an undercoat of a silver halide photosensitive material which is capable of preventing the occurrence of a plane trouble. <P>SOLUTION: An application method of undercoat layers 2 and 3 of a photosensitive material is for forming an easily adhesive SBR undercoat layer 2 and a gelatine undercoat layer 3 on a PET support 1 and successively an image formation layer 4 further on it. In the method, the undercoat layers 2 and 3 are applied by a bar coater and the wet application amount at the time is controlled to be not lower than 7.0 ml/m<SP>2</SP>but not higher than 30 ml/m<SP>2</SP>. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for applying an undercoat layer of a silver halide photosensitive material, and more particularly to a method for applying an undercoat layer of a silver halide photosensitive material for medical diagnosis, industrial photography, printing, and COM.

  In the silver halide light-sensitive material, an undercoat layer is applied between a polyester support and a hydrophilic colloid light-sensitive layer (see Patent Document 1). When a surface failure such as a streak failure or a repelling failure occurs in the application of the undercoat layer, a problem of causing a serious failure in photographic performance occurs. For example, when a surface failure occurs in the undercoat layer on the photosensitive layer side, this surface failure also affects the photosensitive layer, the same surface failure occurs in the photosensitive layer, and the performance deteriorates. In particular, when a surface failure occurs in the application of a layer containing a solid disperse dye, it causes uneven density of the dye, resulting in a difference in the amount of cut of crossover light, and a serious increase / decrease failure in photographic sensitivity. It leads to a wonderful ending.

It has been clarified that the cause of the occurrence of such a planar failure is that agglomerates are generated due to the shearing force during bar coating. Furthermore, it has been found that contamination of the coating solution (soil) due to bacteria in the process generates shear agglomerates. In Cited Document 2, sterilization is performed by holding the coating solution at 50 to 80 ° C. for 10 minutes to 5 hours, thereby suppressing the occurrence of shearing aggregates and reducing the occurrence of planar failures.
JP-A-6-27589 JP 2003-29369 A

  However, the cited document 2 cannot completely prevent the occurrence of aggregates and cannot eliminate the surface failure. In particular, in the circulation system for circulating the coating solution, there is a problem that the sterilization treatment of the coating solution becomes insufficient and aggregates are easily generated.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method for applying an undercoat layer of a silver halide photosensitive material capable of preventing the occurrence of planar failure due to aggregates.

In order to achieve the above object, the undercoat of a silver halide photosensitive material in which an undercoat layer is formed on a support and a silver halide photosensitive layer is formed on the undercoat layer. in the coating method for applying a layer, the subbing layer as well as a bar coater, and characterized by a Wet coating amount at that time below 7.0 ml / m ² or more 30 ml / m ^2.

The inventors of the present invention have found a range of wet coating amounts that can suppress the occurrence of surface defects by adjusting the wet coating amount without changing the coating amount during drying. The present invention has been made based on these findings, since the Wet coating amount when coating by a bar coater was 7.0 ml / m ² or more 30 ml / m ² or less, to prevent the occurrence of surface failure be able to.

In the invention the invention of claim 1 of claim 2, wherein a subbing layer with a plurality of layers formed by a bar coater, the Wet coating amount at the time of application of each layer 7.0 ml / m ² or more 30 ml / m ² It is characterized by the following. By the Wet coating amount at the time each layer of the coating below 7.0 ml / m ² or more 30 ml / m ^2, the occurrence of surface failure can be prevented in each layer.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the undercoat layer contains a solid disperse dye. When the undercoat layer contains a solid disperse dye, aggregates are likely to be generated, but the present invention can prevent this. That is, the present invention is particularly effective when the undercoat layer contains a solid disperse dye.

According to subbing layer coating method of a silver halide light-sensitive material according to the present invention, since the Wet coating amount below 7.0 ml / m ² or more 30 ml / m ^2, planar faults during bar coating the subbing layer Occurrence can be prevented.

  A preferred embodiment of the method for applying the undercoat layer of the silver halide light-sensitive material according to the present invention will be described below with reference to the accompanying drawings.

  The silver halide photosensitive material of the present invention has at least one undercoat layer on a support, and a photosensitive layer is formed on the undercoat layer. In the present invention, the undercoat layer is applied with a bar coater. As shown in FIG. 1, the main configuration of the bar coater 10 includes a columnar bar 12 and a support member 14 that supports the bar 12 in an upper groove. The bar 12 is a driving means (not shown). The web 16 rotates in the running direction. The web 16 is disposed so as to contact the bar 12 at a predetermined wrap angle, and the coating liquid is supplied to the upstream side of the bar 12 with respect to the traveling direction of the web 16. The supplied coating solution is scraped off by the bar 12 and a desired amount of coating solution is applied to the web 16. The configuration of the bar coater 10 is not limited to this. For example, the bar 12 may be rotated in the direction opposite to the traveling direction of the web 16 or may be stopped. Further, as the bar 12, a flat outer peripheral surface, a wire wound, a rolled groove, and the like can be used.

In the present invention, the Wet coating amount when coating by a bar coater 7.0 ml / m ² or more 30 ml / m ² or less, preferably set to 8.0 ml / m ² or more 8.5 ml / m ² or less. If the wet coating amount is increased to 7.0 ml / m ² or more without changing the coating amount at the time of drying (that is, the proportion of the solvent (water, etc.) in the coating solution is increased), the secondary side (that is, The downstream side of the bar with respect to the direction of travel of the support) Foreign matter and bubbles are not held in the meniscus, the frequency of occurrence of streak failure is reduced, and even when it occurs, the length of the streak failure is shortened can get. Further, by increasing the amount of wet coating, thickness unevenness is leveled, and the effect of reducing the strength can be obtained. On the other hand, when the wet coating amount is increased, coating unevenness may occur. However, in the present invention, by setting the wet coating amount to 30 ml / m ² or less, the occurrence of coating unevenness can be prevented.

  Hereinafter, specific embodiments of the silver halide photosensitive material according to the present invention will be described.

  First, the undercoat layer will be described. The coating solution for the undercoat layer contains a hydrophilic colloid. Examples of the hydrophilic colloid include acylated gelatin such as gelatin, phthalated gelatin, and maleated gelatin: cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose: acrylic acid, Grafted gelatin obtained by grafting methacrylic acid or amide (such as acrylamide) onto gelatin: polyvinyl alcohol: polyhydroxyalkyl acrylate: polyvinyl pyrrolidone: vinyl pyrrolidone / vinyl acetate copolymer: gazein: agarose: albumin: sodium alginate: polysaccharide : Agar: Starch: Grafted starch: Polyacrylamide: Polyethylenimine acylated products: Synthetic or natural hydrophilic polymer compounds such as these partial hydrolysates: etc. It is below. These materials can be used alone or in combination. Among these, gelatin is preferable. In addition to the hydrophilic colloid, an acrylic resin, polyester resin, polyurethane resin, polystyrene resin, SBR, PVDC resin, or the like can be used in combination as a binder.

  The undercoat layer coating solution is preferably held at a temperature of 50 to 80 ° C. for 10 minutes to 5 hours before forming the undercoat layer, more preferably at a temperature of 60 to 70 ° C. for 30 minutes to 3 hours. Preferably, the temperature is 60 to 70 ° C. for 1 to 2 hours.

  The pH of the coating solution for the undercoat layer is preferably 4 to 8 from the viewpoint of the stability of the coating solution, more preferably 5 to 8 and even more preferably 6 to 7.

  The coating solution for the undercoat layer preferably contains a monovalent saturated alcohol having 3 or less carbon atoms from the viewpoint of suppressing repelling failure during coating. Preferable examples of the monovalent saturated alcohol include methanol, ethanol, propanol, and isopropanol. These monovalent saturated alcohols may be used alone or in combination of two or more. In addition, these monovalent saturated alcohols are intentionally added for the above-mentioned purpose. For example, they may be added also as a solvent as described later. When used as a solvent, a solvent used in the synthesis of a material, a purification process, or the like, or as a cleaning solvent for a chemical storage tank, piping, etc., it may be mixed with the coating solution. However, the alcohol content in the coating solution is preferably 20% by weight or less, more preferably 1 to 10% by weight.

The undercoat layer coating solution may contain a crosslinking agent, a matting agent, a dye, a filler, a surfactant, and the like. As the crosslinking agent, known compounds such as epoxy, isocyanate, and melamine are used. Further, active halogen crosslinking agents described in JP-A No. 51-114120 are also preferred. The matting agent is preferably used for the purpose of improving high-speed transportability in production. As the matting agent, fine particles such as styrene, polymethyl methacrylate and silica having an average particle diameter of 0.1 to 8 μm, preferably about 0.2 to 5 μm are used. The amount of the matting agent used is preferably 1 to ²⁰⁰ mg, more preferably ^{2 to} 100 mg per 1 m ^{2 of the} photothermographic material. As the filler, colloidal silica or the like can be used. As the surfactant, an anionic, nonionic or cationic surfactant can be used. As the dye, antihalation, a color tone adjusting dye, and the like can be used.

  The undercoat layer coating solution may be either water-based or organic solvent-based, but is preferably a water-based coating solution from the viewpoint of cost and environment. Here, the “aqueous coating solution” refers to a coating solution in which 30% by mass or more, more preferably 50% by mass or more, of the solvent (dispersion medium) of the coating solution is water. Specific examples of the solvent composition include the following mixed solutions in addition to water. Water / methanol = 85/15, water / methanol = 70/30, water / methanol / dimethylformamide (DMF) = 80/15/5, water / isopropyl alcohol = 60/40, etc. To express).

The undercoat layer is formed by applying and drying the above undercoat layer coating solution. In the present invention, a bar coater is used as a coating method. As conditions for the, Wet coating amount of 7.0 ml / m ² or more 30 ml / m ² or less, it is preferably set to less than 8.0 ml / m ² or more 10 ml / m ^2. If the wet coating amount is less than 7.0 ml / m ² , surface failure will occur immediately when agglomeration occurs in the coating solution. However, if the coating amount is 7.0 ml / m ² or more, aggregation occurs. Can also prevent the occurrence of surface failure. Further, when the wet coating amount exceeds 30 ml / m ² , a surface failure such as coating unevenness occurs, but this can be prevented by setting the wet coating amount to 30 ml / m ² or less.

Only one layer of the undercoat layer may be provided, or two or more layers may be provided. However, in the case of providing a plurality of subbing layers, each subbing layer together sequentially applied by a bar coater, its Wet coating amount at the time of each coating 7.0 ml / m ² or more 30 ml / m ² or less, preferably 8.0 ml / m ² or more 10 ml / m ² set below. Thereby, the occurrence of planar failure can be prevented in each undercoat layer. The thickness of each undercoat layer is preferably 0.05 to 5 μm, more preferably about 0.1 to 3 μm per layer.

  Although the drying method after application | coating is not specifically limited, For example, what is necessary is just to be about 0.5 to 20 minutes at the temperature of about 25-200 degreeC, and it can be made to dry on these conditions.

  Next, the support will be described. As the film substrate constituting the support, polyester is preferably used. Specifically, for example, polyethylene terephthalate, polyethylene naphthalate, and a copolymer or a mixture thereof are used. The support is preferably transparent. Moreover, it is suitable for the thickness of a support body that thickness is 100-300 micrometers.

  As the support, in particular, polyester subjected to heat treatment in a temperature range of 130 to 185 ° C. in order to alleviate internal strain remaining in the film during biaxial stretching and eliminate heat shrinkage strain generated during heat development processing, In particular, polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) is preferably used. In the case of a heat-developable recording material for medical use, the transparent support may be colored with a blue dye (for example, dye-1 described in Examples of JP-A-8-240877) or may be uncolored.

  Next, the photosensitive layer in the present invention (hereinafter sometimes referred to as “image forming layer”) will be described. The photosensitive layer preferably contains a photosensitive silver halide. There is no restriction | limiting in particular as a halogen composition of this silver halide, Silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver iodochlorobromide can be used. Of these, silver bromide and silver iodobromide are preferred. The distribution of the halogen composition in the grains may be uniform, the halogen composition may be changed stepwise, or may be continuously changed. Further, silver halide grains having a core / shell structure can be preferably used. A preferable structure is a 2- to 5-fold structure, more preferably a 2- to 4-fold core / shell particle. A technique for localizing silver bromide on the surface of silver chloride or silver chlorobromide grains can also be preferably used.

  Methods for forming photosensitive silver halide are well known in the art, such as those described in Research Disclosure No. 17029, June 1978, and US Pat. No. 3,700,458. Specifically, a method in which a photosensitive silver halide is prepared by adding a silver supply compound and a halogen supply compound to gelatin or another polymer solution and then mixed with an organic silver salt is used. . Further, the method described in paragraph Nos. 0217 to 0224 of JP-A No. 11-119374 and the methods described in Japanese Patent Application No. 11-98708 and Japanese Patent Application No. 2000-42336 are also preferable.

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

  Examples of the shape of silver halide grains include cubes, octahedrons, tabular grains, spherical grains, rod-shaped grains, and potato-shaped grains. In the present invention, cubic grains are particularly preferred. Grains with rounded corners of silver halide grains can also be preferably used. The surface index (Miller index) on the outer surface of the photosensitive silver halide grain is not particularly limited, but the ratio of the {100} plane, which has high spectral sensitizing efficiency when adsorbed by the spectral sensitizing dye, is high. preferable. The ratio is preferably 50% or more, more preferably 65% or more, and still more preferably 80% or more. The ratio of the Miller index {100} plane is calculated by T.Tani; J.Imaging Sci., 29, 165 (1985) using the adsorption dependency of {111} plane and {100} plane in the adsorption of a sensitizing dye. It can obtain | require by the method of description.

In the present invention, silver halide grains in which a hexacyano metal complex is present on the outermost surface of the grains are preferred. The hexacyano metal complexes include [Fe (CN) ₆ ] ^4- , [Fe (CN) ₆ ] ^3- , [Ru (CN) ₆ ] ^4- , [Os (CN) ₆ ] ^4- , [Co ( CN) ₆ ] ^3- , [Rh (CN) ₆ ] ^3- , [Ir (CN) ₆ ] ^3- , [Cr (CN) ₆ ] ^3- , [Re (CN) ₆ ] ^3- . In the present invention, a hexacyano Fe complex is preferred.

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

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

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

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

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

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

The photosensitive silver halide grains in the invention can contain a metal or metal complex of Group 8 to Group 10 of the Periodic Table (showing Groups 1 to 18). As the central metal of the group 8 to group 10 metal or metal complex of the periodic table, rhodium, ruthenium and iridium are preferable. One kind of these metal complexes may be used, or two or more kinds of complexes of the same metal and different metals may be used in combination. The preferred content is in the range of 1 × 10 ⁻⁹ mol to 1 × 10 ⁻³ mol with ^respect to 1 mol of silver. About these heavy metals and metal complexes and their addition methods, they are described in JP-A-7-225449, JP-A-11-65021, paragraphs 0018 to 0024, and JP-A-11-119374, paragraphs 0227 to 0240. Has been.

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

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

Sensitizing dyes that can be applied to the present invention are those that can spectrally sensitize silver halide grains in the desired wavelength region when adsorbed on silver halide grains, and have a spectral sensitivity suitable for the spectral characteristics of the exposure light source. The sensitive dye can be advantageously selected. Regarding the sensitizing dye and the addition method, paragraphs 0103 to 0109 of JP-A-11-65021, compounds represented by the general formula (II) of JP-A-10-186572, and JP-A-11-119374 A dye represented by formula (I) and the dye described in Example 5 of paragraph No. 0106, US Pat. Nos. 5,510,236 and 3,871,887; No. 96131, JP-A-59-48753, dyes disclosed in European Patent Publication No. 0803764A1, page 19, line 38 to page 20, line 35, Japanese Patent Application No. 2000-86865, This is described in Japanese Patent Application Nos. 2000-102560 and 2000-205399. These sensitizing dyes may be used alone or in combination of two or more. In the present invention, the time when the sensitizing dye is added to the silver halide emulsion is preferably the time from the desalting step to the coating, and more preferably the time from the desalting to the start of chemical ripening. The addition amount of the sensitizing dye in the present invention can be set to a desired amount in accordance with sensitivity and fogging performance, but is preferably 10 ⁻⁶ to 1 mol, more preferably 1 mol per mol of silver halide in the photosensitive layer. Is 10 ⁻⁴ to 10 ⁻¹ mol.

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

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

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

  The photosensitive silver halide emulsion in the recording material used in the present invention may be only one kind, or two or more kinds (for example, those having different average grain sizes, those having different halogen compositions, those having different crystal habits, chemical increases). Those having different feeling conditions) may be used in combination. The gradation can be adjusted by using a plurality of types of photosensitive silver halides having different sensitivities. As technologies relating to these, Japanese Patent Application Laid-Open Nos. 57-119341, 53-106125, 47-3929, 48-55730, 46-5187, 50-73627, 57-150841 etc. are mentioned. The sensitivity difference is preferably 0.2 log E or more for each emulsion.

The addition amount of the photosensitive silver halide is preferably 0.03 to 0.6 g / m ² and expressed as 0.04 to 0.4 g / m ² in terms of the amount of silver coated per 1 m ² of the recording material. More preferably, it is most preferably 0.05 to 0.3 g / m ² , and the photosensitive silver halide is 0.01 mol or more and 0.5 mol or less with respect to 1 mol of the organic silver salt. Preferably, 0.02 mol or more and 0.3 mol or less are more preferable.

  Regarding the mixing method and mixing conditions of the separately prepared photosensitive silver halide and organic silver salt, the silver halide grains and organic silver salt that were prepared respectively were mixed with a high-speed stirrer, ball mill, sand mill, colloid mill, vibration mill, homogenizer. Etc., or a method of preparing an organic silver salt by mixing photosensitive silver halide that has been prepared at any timing during the preparation of the organic silver salt, etc., but the effect of the present invention is sufficient As long as it appears in, there is no particular limitation. Moreover, mixing two or more organic silver salt aqueous dispersions and two or more photosensitive silver salt aqueous dispersions when mixing is a preferred method for adjusting photographic characteristics.

  The preferred addition time of the silver halide to the image forming layer coating solution in the present invention is from 180 minutes before coating to immediately before, preferably from 60 minutes to 10 seconds before coating. There is no particular limitation as long as the effect is sufficiently exhibited. Specific mixing methods include mixing in a tank in which the average residence time calculated from the addition flow rate and the amount of liquid delivered to the coater is the desired time, and by N. Harnby, MFEdwards, AWNienow, Takahashi There is a method using a static mixer or the like described in Chapter 8 of the translation of Koji “Liquid Mixing Technology” (published by Nikkan Kogyo Shimbun, 1989).

  The photosensitive layer may contain silver behenate or an organic silver salt other than silver behenate as a non-photosensitive organic silver salt. As the organic silver salt, a silver salt of an organic acid, particularly a silver salt of a long chain aliphatic carboxylic acid (having 10 to 30, preferably 15 to 28 carbon atoms) is preferable. Preferable examples of the organic silver salt include silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, and a mixture thereof. The shape of silver behenate and organic silver salts other than silver behenate is not particularly limited, and may be acicular, rod-like, flat, or flake shaped.

  In the present invention, scaly organic silver salts are preferred. In the present specification, the scaly organic silver salt is defined as follows. The organic silver salt is observed with an electron microscope, the shape of the organic silver salt particle is approximated to a rectangular parallelepiped, and the sides of the rectangular parallelepiped are defined as a, b, and c from the shortest side (even though c is the same as b) Good)), and calculate with the shorter numbers a and b, and find x as follows. x = b / a. In this way, x is obtained for about 200 particles, and when the average value x (average) is obtained, particles satisfying the relationship of x (average) ≧ 1.5 are defined as flakes. Preferably, 30 ≧ x (average) ≧ 1.5, more preferably 20 ≧ x (average) ≧ 2.0. Incidentally, the needle shape is 1 ≦ x (average) <1.5.

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

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

  Known methods and the like can be applied to the production and dispersion method of the organic silver salt used in the present invention. For example, JP-A-08-234358, JP-A-10-62899, European Patent Publication No. 0803763A1, European Patent Publication No. 0968212A1, JP-A-11-349591, JP-A-2000-7683, 2000-72711, 2000-53682, 2000-75437, 2000-86669, 2000-143578, 2000-178278, 2000-256254, Japanese Patent Application No. 11-348228-30, 11-203413, 11-115457, 11-180369, 11-297964, 11-157638, 11-208201, Japanese Patent Application Nos. 2000-90093, 2000-195621, 2000 -191226, 2000-213 No. 13, the same 2000-214155 Patent, each specification and the like of Nos. 2000-191226 can be referred to.

  In addition, when the photosensitive silver salt is allowed to coexist at the time of dispersion of the organic silver salt, the fog is increased and the sensitivity is remarkably lowered. Therefore, it is more preferable that the photosensitive silver salt is not substantially contained at the time of dispersion. In the present invention, the amount of the photosensitive silver salt in the aqueous dispersion to be dispersed is 0.1 mol% or less with respect to 1 mol of the organic silver salt in the liquid, and no positive addition of the photosensitive silver salt is performed. Is.

  In the present invention, it is possible to produce a recording material by mixing an organic silver salt aqueous dispersion and a photosensitive silver salt aqueous dispersion, but the mixing ratio of the organic silver salt and the photosensitive silver salt is selected according to the purpose. The ratio of the photosensitive silver salt to the organic silver salt is preferably in the range of 1 to 30 mol%, more preferably 3 to 20 mol%, and particularly preferably 5 to 15 mol%. Mixing two or more organic silver salt aqueous dispersions and two or more photosensitive silver salt aqueous dispersions when mixing is a method preferably used for adjusting photographic characteristics.

The organic silver salt in the present invention can be used in a desired amount, preferably 0.1-5 g / m ² as silver amount, more preferably from 1 to 3 g / m ^2.

  In the present invention, the heat developable recording material obtained preferably contains a reducing agent for organic silver salt. The reducing agent for the organic silver salt may be any substance (preferably an organic substance) that reduces silver ions to metallic silver. Such a reducing agent is described in paragraph Nos. 0043 to 0045 of JP-A No. 11-65021 and page 7, line 34 to page 18, line 12 of European Patent Publication No. 0803764A1. In the present invention, the reducing agent is preferably a hindered phenol reducing agent or a bisphenol reducing agent, and more preferably a compound represented by the general formula (I) described in Japanese Patent Application No. 2000-358846.

  Specific examples of the reducing agent preferably used in the present invention include those described in Japanese Patent Application No. 2000-358846.

The addition amount of the reducing agent is preferably a 0.01~5.0g / m ^2, more preferably from 0.1 to 3.0 g / m ^2, a photosensitive layer (hereinafter, "image It is preferably contained in an amount of 5 to 50 mol%, more preferably 10 to 40 mol%, relative to 1 mol of silver on the surface having a “formation layer”. The reducing agent is preferably contained in the image forming layer.

  The reducing agent may be contained in the coating liquid by any method such as a solution form, an emulsified dispersion form, or a solid fine particle dispersion form, and may be contained in the recording material. Well-known emulsifying dispersion methods include dissolving oil using an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, or an auxiliary solvent such as ethyl acetate or cyclohexanone, and mechanically dispersing the emulsified dispersion. The method of producing is mentioned.

  Further, as a solid fine particle dispersion method, a reducing agent powder is dispersed in an appropriate solvent such as water by a ball mill, a colloid mill, a vibration ball mill, a sand mill, a jet mill, a roller mill, or an ultrasonic wave to produce a solid dispersion. A method is mentioned. In this case, a protective colloid (for example, polyvinyl alcohol) or a surfactant (for example, an anionic surfactant such as sodium triisopropylnaphthalenesulfonate (a mixture of three isopropyl groups having different substitution positions)) may be used. Good. The aqueous dispersion can contain a preservative (eg, benzoisothiazolinone sodium salt).

  In the present invention, a phenol derivative represented by the formula (A) described in Japanese Patent Application No. 11-73951 is preferably used as the development accelerator in the resulting heat-developable recording material.

  When the reducing agent in the present invention has an aromatic hydroxyl group (—OH), particularly in the case of the aforementioned bisphenols, a non-reducing compound having a group capable of forming a hydrogen bond with these groups It is preferable to use together. Examples of the group that forms a hydrogen bond with a hydroxyl group or an amino group include a phosphoryl group, a sulfoxide group, a sulfonyl group, a carbonyl group, an amide group, an ester group, a urethane group, a ureido group, a tertiary amino group, and a nitrogen-containing aromatic group. Can be mentioned. Among them, preferred are a phosphoryl group, a sulfoxide group, an amide group (however, it has no> N—H group and is blocked like> N—Ra (Ra is a substituent other than H)), a urethane group. (However, it has no> N—H group and is blocked like> N—Ra (Ra is a substituent other than H)), a ureido group (however, it does not have a> N—H group, N-Ra (Ra is a substituent other than H).) In the present invention, particularly preferred hydrogen bonding compounds are compounds represented by the general formula (II) described in Japanese Patent Application No. 2000-358846.

  Specific examples of the hydrogen bonding compound preferably used in the present invention include those described in Japanese Patent Application No. 2000-358846.

  Specific examples of the hydrogen bonding compound include those described in the specifications of Japanese Patent Application Nos. 2000-192191 and 2000-19481 in addition to the above. The compound of the general formula (II) described in Japanese Patent Application No. 2000-358846 used in the present invention is contained in a coating solution in the form of a solution, an emulsified dispersion, and a solid dispersed fine particle dispersion, similarly to the reducing agent. It can be used in recording materials. The compound forms a hydrogen-bonding complex with a compound having a phenolic hydroxyl group or amino group in a solution state, and depending on the combination of the reducing agent and the compound of the general formula (II), It can be isolated. The use of the crystal powder isolated in this way as a solid dispersed fine particle dispersion is particularly preferable for obtaining stable performance. Further, a method in which a reducing agent and the compound of the general formula (II) are mixed as a powder and complexed at the time of dispersion with a sand grinder mill or the like using an appropriate dispersant can be preferably used. The compound of the general formula (II) is preferably used in an amount of 1 to 200 mol%, more preferably 10 to 150 mol%, still more preferably 30 to 100 mol%, based on the reducing agent. It is a range.

  The binder of the organic silver salt-containing layer in the present invention may be any polymer, and suitable binders are transparent or translucent and generally colorless, natural resins and polymers and copolymers, synthetic resins and polymers and copolymers, etc. Film-forming media such as gelatins, rubbers, poly (vinyl alcohol) s, hydroxyethyl celluloses, cellulose acetates, cellulose acetate butyrates, poly (vinyl pyrrolidone) s, casein, starch, poly (acrylic acid) ), Poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid), styrene-maleic anhydride copolymers, styrene-acrylonitrile copolymers, styrene-butadiene copolymers , Poly (vinyl acetals) (e.g., poly (vinyl Nylformal) and poly (vinyl butyral)), poly (esters), poly (urethanes), phenoxy resins, poly (vinylidene chloride) s, poly (epoxides), poly (carbonates), poly (vinyl acetate) , Poly (olefin) s, cellulose esters, and poly (amides). The binder may be formed from water or an organic solvent or an emulsion.

  The glass transition temperature of the binder of the layer containing the organic silver salt is preferably 10 ° C. or higher and 80 ° C. or lower (hereinafter sometimes referred to as a high Tg binder), more preferably 20 ° C. or higher and 70 ° C. or lower, More preferably, it is 23 degreeC or more and 65 degrees C or less.

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

  The polymer used as a binder may be used alone or in combination of two or more as required. Further, a glass transition temperature of 20 ° C. or higher and a glass transition temperature of less than 20 ° C. may be used in combination. When two or more kinds of polymers having different Tg are blended and used, the weight average Tg is preferably within the above range.

  For example, when the organic silver salt-containing layer is formed using a coating solution in which 30% by mass or more of the solvent is water and dried, the binder of the organic silver salt-containing layer is further converted into an aqueous solvent (aqueous solvent). When it is soluble or dispersible, the performance is improved particularly when it is made of a latex of a polymer having an equilibrium water content of 2% by mass or less at 25 ° C. and 60% RH. The most preferable form is one prepared so that the ionic conductivity is 2.5 mS / cm or less, and as such a preparation method, there is a method of performing purification treatment using a separation functional membrane after polymer synthesis.

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

  In the case of a system in which the polymer is not dissolved thermodynamically and exists in a so-called dispersed state, the term aqueous solvent is used here.

  The “equilibrium moisture content at 25 ° C. and 60% RH” is the following using the weight W1 of the polymer in the humidity-controlled equilibrium under the atmosphere of 25 ° C. and 60% RH and the weight W0 of the polymer in the absolutely dry state at 25 ° C. It can be expressed as: Equilibrium moisture content at 25 ° C. and 60% RH = {(W1−W0) / W0} × 100 (mass%). For the definition and measurement method of moisture content, for example, Polymer Engineering Course 14, Polymer Material Testing Method (Edited by Society of Polymer Sciences, Jinshokan) can be referred to.

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

  In the present invention, a polymer dispersible in an aqueous solvent is particularly preferred. Examples of the dispersed state include latex in which fine particles of a water-insoluble hydrophobic polymer are dispersed and polymer molecules in which a molecular state or micelle is dispersed, and all are preferable. The average particle size of the dispersed particles is in the range of about 1 to 50000 nm, more preferably about 5 to 1000 nm. The particle size distribution of the dispersed particles is not particularly limited, and may have a wide particle size distribution or a monodispersed particle size distribution.

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

Specific examples of the preferred polymer latex include the following. Below, it represents using a raw material monomer, the numerical value in a parenthesis is the mass%, and molecular weight is a number average molecular weight. When a polyfunctional monomer was used, the concept of molecular weight was not applicable because a crosslinked structure was formed, so it was described as crosslinkable and the molecular weight description was omitted. Tg represents the glass transition temperature.
P-1; -MMA (70) -EA (27) -MAA (3)-latex (molecular weight 37000) P-2; -MMA (70) -2EHA (20) -St (5) -AA (5) -Latex (molecular weight 40000) P-3; -St (50) -Bu (47) -MAA (3)-Latex (crosslinkable) P-4; -St (68) -Bu (29) -AA ( 3) -Latex (crosslinkable) P-5; -St (71) -Bu (26) -AA (3) -Latex (crosslinkable, Tg24 ° C) P-6; -St (70) -Bu ( 27) -IA (3)-Latex (crosslinkable) P-7; -St (75) -Bu (24) -AA (1)-Latex (crosslinkable) P-8; -St (60)- Latex of Bu (35) -DVB (3) -MAA (2)-(crosslinkable) P-9; Latex of -St (70) -Bu (25) -DVB (2) -AA (3)-(crosslinked) P-10; -VC (50) -MMA (20) -EA (20) -AN (5) -AA (5)-latex (molecular weight 80000) P-11; -VDC (85) -MMA ( 5) -EA (5) -MAA (5)-latex (molecular weight 67000) P-12; -Et (90) -MAA (10)-latex (molecular weight 12000) P-13; -St (70)- 2EHA (27) -AA (3) latex (molecular weight 130000) P-14; -MMA (63) -EA (35)-AA (2) latex (molecular weight 33000) P-15; -St (70.5)- Latex of Bu (26.5) -AA (3)-(crosslinkable, Tg23 ℃) P-16; Latex of -St (69.5) -Bu (27.5) -AA (3)-(crosslinkable , Tg20.5 ℃)
The abbreviations for the above structures represent the following monomers. MMA; Methyl methacrylate, EA; Ethyl acrylate, MAA; Methacrylic acid, 2EHA; 2-Ethylhexyl acrylate, St; Styrene, Bu; Butadiene, AA; Acrylic acid, DVB; Divinylbenzene, VC; Vinyl chloride, AN; Acrylonitrile, VDC Vinylidene chloride, Et; ethylene, IA; itaconic acid.

  The polymer latex described above is also commercially available, and the following polymers can be used. Examples of acrylic polymers include poly (esters) such as Sebian A-4635, 4718, 4601 (manufactured by Daicel Chemical Industries, Ltd.), Nipol Lx811, 814, 821, 820, 857 (manufactured by Nippon Zeon Co., Ltd.). Examples of poly (urethanes) such as FINITEXES650, 611, 675, and 850 (manufactured by Dainippon Ink Chemical Co., Ltd.), WD-size, and WMS (manufactured by Eastman Chemical) Examples of rubbers such as HYDRANAP10, 20, 30, 40 (manufactured by Dainippon Ink Chemical Co., Ltd.) include LACSTAR 7310K, 3307B, 4700H, 7132C (manufactured by Dainippon Ink Chemical Co., Ltd.), Nipol Lx416, 410, Such as 438C, 2507 (manufactured by Nippon Zeon Co., Ltd.) Examples of (vinyl chloride) include G351 and G576 (manufactured by Nippon Zeon Co., Ltd.), and examples of poly (vinylidene chloride) include L502, L513 (manufactured by Asahi Kasei Kogyo Co., Ltd.) and other poly Examples of (olefin) s include Chemipearl S120 and SA100 (all manufactured by Mitsui Petrochemical Co., Ltd.).

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

  As the polymer latex used in the present invention, a styrene-butadiene copolymer latex is particularly preferable. The weight ratio of the styrene monomer unit to the butadiene monomer unit in the styrene-butadiene copolymer is preferably 40:60 to 95: 5. The proportion of the styrene monomer unit and the butadiene monomer unit in the copolymer is preferably 60 to 99% by mass. The preferred molecular weight range is the same as described above.

  Examples of latexes of styrene-butadiene copolymer that are preferably used in the present invention include the aforementioned P-3 to P-8, 14, and 15, commercially available LACSTAR-3307B, 7132C, and NipolLx416.

  In the present invention, a hydrophilic polymer such as gelatin, polyvinyl alcohol, methyl cellulose, hydroxypropyl cellulose, or carboxymethyl cellulose may be added to the organic silver salt-containing layer as necessary. The addition amount of these hydrophilic polymers is 30% by mass or less, more preferably 20% by mass or less, based on the total binder of the organic silver salt-containing layer.

  The organic silver salt-containing layer (that is, the image forming layer) in the present invention is preferably formed using a polymer latex. The amount of the binder in the organic silver salt-containing layer is preferably such that the weight ratio of total binder / organic silver salt is 1/10 to 10/1, more preferably 1/5 to 4/1.

  Further, such an organic silver salt-containing layer is usually a photosensitive layer (emulsion layer) containing a photosensitive silver halide which is a photosensitive silver salt. The weight ratio of silver halide is preferably 400-5, more preferably 200-10.

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

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

  Antifoggants, stabilizers and stabilizer precursors that can be used in the present invention are described in paragraph No. 0070 of JP-A-10-62899, page 20, line 57 to page 21 of European Patent Publication No. 0803764A1. The compounds described in the patents described in the seventh row, and the compounds described in JP-A-9-281737 and JP-A-9-329864 are exemplified. Further, the antifoggant preferably used in the present invention is an organic halide, and examples thereof include those disclosed in Japanese Patent Application Laid-Open No. 11-65021, paragraphs 0111 to 0112. In particular, an organic halogen compound represented by formula (P) in Japanese Patent Application No. 11-87297, an organic polyhalogen compound represented by general formula (II) in Japanese Patent Application Laid-Open No. 10-339934, and Japanese Patent Application No. 11-205330. The organic polyhalogen compounds described in the publication No. are preferred. Furthermore, the organic polyhalogen compound preferably used in the present invention is a compound represented by the general formula (III) described in Japanese Patent Application No. 2000-358846, and specific examples thereof are those described in the specification. Is mentioned.

In the present invention, the compound represented by the general formula (III) described in Japanese Patent Application No. 2000-358846 is used in the range of 10 ⁻⁴ to 1 mol per mol of the non-photosensitive organic silver salt of the image forming layer. It is preferable to use in the range of 10 ^{−3 to} 0.8 mol, and it is particularly preferable to use in the range of 5 × 10 ^{−3 to} 0.5 mol. In the present invention, examples of the method for incorporating the antifoggant into the recording material include the method described in the method for containing the reducing agent, and it is preferable to add the organic polyhalogen compound as a solid fine particle dispersion.

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

In the present invention, an azolium salt may be contained for the purpose of fog prevention. Examples of the azolium salt include compounds represented by the general formula (XI) described in JP-A-59-193447, compounds described in JP-B-55-12581, and compounds described in JP-A-60-153039. The compound represented by general formula (II) is mentioned. The azolium salt may be added to any part of the recording material, but the addition layer is preferably added to the layer having the photosensitive layer, and more preferably to the organic silver salt-containing layer. The azolium salt may be added at any step of preparing the coating solution, and when added to the organic silver salt-containing layer, any step from the preparation of the organic silver salt to the preparation of the coating solution may be used. It is preferable immediately after application after preparation. As an addition method of the azolium salt, any method such as a powder, a solution, or a fine particle dispersion may be used. Moreover, you may add as a solution mixed with other additives, such as a sensitizing dye, a reducing agent, and a color toning agent. In the present invention, the azolium salt may be added in any amount, but preferably 1 × 10 ⁻⁶ mol to 2 mol, and more preferably 1 × 10 ⁻³ mol to 0.5 mol, per mol of silver.

  In the present invention, a mercapto compound, a disulfide compound, and a thione compound may be contained in order to suppress or promote development and control development, to improve spectral sensitization efficiency, and to improve storage stability before and after development. JP-A-10-62899, paragraphs 0067 to 0069, JP-A-10-186572, general formula (I), and specific examples thereof include paragraphs 0033 to 0052, European Patent Publication No. 0803764A1. No. 20 page 36-56, Japanese Patent Application No. 11-273670, and the like. Of these, mercapto-substituted heteroaromatic compounds are preferred.

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

  Regarding the plasticizer and lubricant that can be used in the photosensitive layer in the present invention, paragraph No. 0117 of JP-A No. 11-65021, a super-high contrast agent for forming a super-high contrast image, and its addition method and amount Paragraph No. 0118, Paragraph Nos. 0136 to 0193 of JP-A-11-223898, Formula (H), Formulas (1) to (3), Formula (A) of Japanese Patent Application No. 11-87297, Regarding compounds of (B), compounds of general formulas (III) to (V) described in Japanese Patent Application No. 11-91652 (specific compounds: Chemical Formula 21 to Chemical Formula 24), and high contrast accelerators, JP-A-11 -65021, paragraph number 0102, and JP-A-11-223898, paragraph numbers 0194 to 0195.

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

In the present invention, when using a super-high contrast agent, it is preferable to use an acid formed by hydrating diphosphorus pentoxide or a salt thereof in combination. Acids or salts thereof formed by hydration of diphosphorus pentoxide include metaphosphoric acid (salt), pyrophosphoric acid (salt), orthophosphoric acid (salt), triphosphoric acid (salt), tetraphosphoric acid (salt), hexametalin An acid (salt) etc. can be mentioned. Examples of the acid or salt thereof formed by hydrating diphosphorus pentoxide particularly preferably include orthophosphoric acid (salt) and hexametaphosphoric acid (salt). Specific examples of the salt include sodium orthophosphate, sodium dihydrogen orthophosphate, sodium hexametaphosphate, and ammonium hexametaphosphate. The amount of acid or salt thereof formed by hydrating diphosphorus pentoxide (the coating amount per 1 m @ 2 of recording material) may be a desired amount according to the performance such as sensitivity and fog, but is 0.1 to 500 mg / m ² is preferable, and 0.5 to 100 mg / m ² is more preferable.

In the present invention, a surface protective layer can be provided for the purpose of preventing adhesion of the image forming layer. The surface protective layer may be a single layer or a plurality of layers. The surface protective layer is described in JP-A No. 11-65021, paragraphs 0119 to 0120 and Japanese Patent Application No. 2000-171936. As the binder for the surface protective layer in the present invention, gelatin is preferable, but polyvinyl alcohol (PVA) is preferably used or used in combination. As gelatin, inert gelatin (for example, Nitta gelatin 750), phthalated gelatin (for example, Nitta gelatin 801), or the like can be used. Examples of PVA include those described in paragraph Nos. 0009 to 0020 of JP-A No. 2000-171936. Completely saponified PVA-105, partially saponified PVA-205, PVA-335, and modified polyvinyl alcohol MP. Preferred is -203 (trade name, manufactured by Kuraray Co., Ltd.). Preferably 0.3 to 4.0 g / m ² of polyvinyl alcohol coating amount as (per support 1 m ²⁾ is the protective layer (per one layer), 0.3 to 2.0 g / m ² is more preferable.

In the present invention, it is preferable to use a polymer latex for the surface protective layer or the back layer, particularly when a heat-developable recording material is used for printing applications in which dimensional change is a problem. For such polymer latex, “Synthetic Resin Emulsion (Hiraku Okuda, Hiroshi Inagaki, Published by Polymer Press (1978))”, “Application of Synthetic Latex (Takaaki Sugimura, Ikuo Kataoka, Junichi Suzuki, Keiji Kasahara, Published by Kobunshi Shuppankai (1993)) and “Synthetic Latex Chemistry (Muroichi Muroi, published by Seikatsu Shuppankai (1970))”, specifically, methyl methacrylate (33.5% by mass). ) / Ethyl acrylate (50% by weight) / methacrylic acid (16.5% by weight) copolymer latex, methyl methacrylate (47.5% by weight) / butadiene (47.5% by weight) / itaconic acid (5% by weight) copolymer Latex of ethyl acrylate / methacrylic acid copolymer, methyl methacrylate (58.9% by weight) / 2-ethyl Latex of hexyl acrylate (25.4% by weight) / styrene (8.6% by weight) / 2-hydroxyethyl methacrylate (5.1% by weight) / acrylic acid (2.0% by weight) copolymer, methyl methacrylate (64. 0 mass%) / styrene (9.0 mass%) / butyl acrylate (20.0 mass%) / 2-hydroxyethyl methacrylate (5.0 mass%) / acrylic acid (2.0 mass%) copolymer latex, etc. Is mentioned. Further, as a binder for the surface protective layer, a combination of polymer latex described in Japanese Patent Application No. 11-6872, the technique described in paragraph Nos. 0021 to 0025 of Japanese Patent Application No. 11-143058, and Japanese Patent Application No. 11- The technique described in paragraph Nos. 0027 to 0028 of No. 6872 and the technique described in paragraph Nos. 0023 to 0041 of Japanese Patent Application No. 10-199626 may be applied. The ratio of the polymer latex in the surface protective layer is preferably 10% by mass or more and 90% by mass or less, and particularly preferably 20% by mass or more and 80% by mass or less of the total binder. Total binder (including water-soluble polymer and latex polymer) preferably 0.3 to 5.0 g / m ² as a coating amount (per support 1 m ²⁾ of the surface protective layer (per one layer), 0.3-2 0.0 g / m ² is more preferable.

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

  The image forming layer in the invention is composed of one or more layers on a support. In the case of a single layer, it consists of an organic silver salt, a photosensitive silver halide, a reducing agent and a binder, and optionally contains additional materials such as toning agents, coating aids and other auxiliary agents. In the case of two or more layers, the first image forming layer (usually a layer adjacent to the support) contains an organic silver salt and a photosensitive silver halide, and some of the second image forming layer or both layers include Must contain other ingredients. The construction of a multicolor photosensitive photothermographic material may include a combination of these two layers for each color, and all within a single layer as described in US Pat. No. 4,708,928. May be included. In the case of multi-dye multicolor photosensitive photothermographic materials, each emulsion layer is generally functional or non-functional between each photosensitive layer as described in U.S. Pat. No. 4,460,681. By using functional barrier layers, they are kept separate from each other.

  The photosensitive layer in the present invention has various dyes and pigments (for example, CIPigment Blue 60, CIPigment Blue 64, and CIPigment Blue 15: 6) from the viewpoints of color tone improvement, interference fringe generation prevention during laser exposure, and irradiation prevention. Can be used. These are described in detail in WO98 / 36322, JP-A-10-268465, JP-A-11-338098, and the like.

  In the present invention, the antihalation layer can be provided on the side farther from the light source than the photosensitive layer.

  In the present invention, in general, in addition to the photosensitive layer, it has a non-photosensitive layer. The non-photosensitive layer is composed of (1) a protective layer provided on the photosensitive layer (on the side farther from the support), and (2) a plurality of photosensitive layers or between the photosensitive layer and the protective layer. An intermediate layer provided between them, (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 recording material as the layer (1) or (2). The antihalation layer is provided on the recording material as the layer (3) or (4).

  Regarding the antihalation layer, paragraphs 0123 to 0124 of JP-A-11-65021, JP-A-11-223898, JP-A-9-230531, JP-A-10-36695, JP-A-10-104797, -231457, 11-352625, 11-352626 and the like. The antihalation layer contains an antihalation dye having absorption at the exposure wavelength. When the exposure wavelength is in the infrared region, an infrared absorbing dye may be used, and in that case, a dye having no absorption in the visible region is preferable. When antihalation is performed using a dye having absorption in the visible range, it is preferable that substantially no dye color remains after image formation, and a means for decoloring by the heat of heat development is used. In particular, it is preferable to add a thermally decolorable dye and a base precursor to the non-photosensitive layer to function as an antihalation layer. These techniques are described in JP-A-11-231457.

The amount of decoloring dye added is determined by the use of the dye. In general, the optical density (absorbance) when measured at the target wavelength is used in an amount exceeding 0.1. The optical density is preferably 0.2-2. The amount of dye used to obtain such an optical density is generally about 0.001 to 1 g / m ² .

  When the dye is decolored in this way, the optical density after heat development can be reduced to 0.1 or less. Two or more kinds of decoloring dyes may be used in combination in a heat decoloring type recording material or a heat development recording material. Similarly, two or more kinds of base precursors may be used in combination. In the thermal decolorization using such decoloring dye and base precursor, a substance (for example, diphenylsulfone, which lowers the melting point by 3 ° C. (deg) or more when mixed with a base precursor as described in JP-A No. 11-352626). 4-Chlorophenyl (phenyl) sulfone) is preferably used in view of thermal decoloring properties and the like.

In the present invention, a colorant having an absorption maximum at 300 to 450 nm can be added for the purpose of improving the silver color tone and the temporal change of the image. Such colorants are disclosed in JP-A-62-210458, JP-A-63-104046, JP-A-63-103235, JP-A-63-208846, JP-A-63-306436, JP-A-63-141435, and JP-A-01-61745. No. 11-276751 and the like. Such a colorant is usually added in the range of 0.1 mg / m ^{2 to 1} g / m ² , and the back layer provided on the opposite side of the photosensitive layer is preferable as the layer to be added.

  In the present invention, the heat-developable recording material obtained is a so-called single-sided recording material having a photosensitive layer containing at least one silver halide emulsion on one side of the support and a back layer on the other side. Preferably there is.

In the present invention, it is preferable to add a matting agent for improving transportability, and the matting agent is described in paragraph numbers 0126 to 0127 of JP-A No. 11-65021. The matting agent is preferably 1 to 400 mg / m ² , more preferably 5 to 300 mg / m ² in terms of the coating amount per 1 m ² of the recording material. The matte degree of the emulsion surface may be any as long as no stardust failure occurs, but the Beck smoothness is preferably 30 seconds or more and 2000 seconds or less, and particularly preferably 40 seconds or more and 1500 seconds or less. The Beck smoothness can be easily determined according to Japanese Industrial Standard (JIS) P8119 “Smoothness test method using Beck tester for paper and paperboard” and TAPPI standard method T479.

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

  In the present invention, the matting agent is preferably contained in the outermost surface layer of the recording material, the layer functioning as the outermost surface layer, or a layer close to the outer surface, and is contained in a layer acting as a so-called protective layer. It is preferable.

  The back layer which can be applied to the present invention is described in paragraph numbers 0128 to 0130 of JP-A No. 11-65021.

  In the present invention, the obtained heat-sensitive recording material preferably has a film surface pH of 7.0 or less, more preferably 6.6 or less before heat development. The lower limit is not particularly limited, but is about 3. The most preferred pH range is in the range of 4 to 6.2. For adjusting the film surface pH, it is preferable to use an organic acid such as a phthalic acid derivative, a non-volatile acid such as sulfuric acid, or a volatile base such as ammonia from the viewpoint of reducing the film surface pH. In particular, ammonia is volatile and is preferable for achieving a low film surface pH because it can be removed before the coating process or thermal development. In addition, it is also preferable to use ammonia in combination with a nonvolatile base such as sodium hydroxide, potassium hydroxide, or lithium hydroxide. The method for measuring the film surface pH is described in paragraph No. 0123 of Japanese Patent Application No. 11-87297.

  A hardener may be used for each layer such as the photosensitive layer, protective layer, and back layer in the present invention. Examples of hardeners include TH THEMEYS “THE THEORY OF THE PHOTOGRAPHIC PROCESS FOURTH EDITION” (published by Macmillan Publishing Co., Inc., 1977), pages 77 to 87. In addition to 4-dichloro-6-hydroxy-s-triazine sodium salt, N, N-ethylenebis (vinylsulfonacetamide), N, N-propylenebis (vinylsulfonacetamide), polyvalent metals described on page 78 of the same book Ion, polyisocyanates such as US Pat. No. 4,281,060, JP-A-6-208193, epoxy compounds such as US Pat. No. 4,791,042, JP-A 62-89048 Vinyl sulfone compounds such as are preferably used.

  The hardening agent is added as a solution, and the addition time of this solution into the protective layer coating solution is from 180 minutes before to immediately before application, preferably from 60 minutes to 10 seconds before application. Is not particularly limited as long as the effects of the present invention are sufficiently exhibited. As a specific mixing method, a method of mixing in a tank in which the average residence time calculated from the addition flow rate and the amount of liquid fed to the coater becomes a desired time, or by N. Harnby, MFEdwards, AWNienow, There is a method of using a static mixer described in Chapter 8 of Koji Takahashi's “Liquid Mixing Technology” (Nikkan Kogyo Shimbun, 1989).

  For the surfactant applicable to the present invention, paragraph No. 0132 of JP-A No. 11-65021, for the solvent, paragraph No. 0133 of the publication, for the support, paragraph No. 0134 of the publication, antistatic or conductive For the layer, paragraph number 0135 of the same publication, for the method of obtaining a color image, paragraph number 0136 of the publication, for the slip agent, paragraph numbers 0061 to 0064 of Japanese Patent Application Laid-Open No. 11-84573 and Japanese Patent Application No. 11- It is described in paragraph Nos. 0049 to 0062 of No. 106881 specification.

  In the present invention, the heat-developable recording material obtained is preferably a mono-sheet type (a type capable of forming an image on the heat-developable recording material without using another sheet such as an image receiving material).

  In the present invention, an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber or a coating aid may be further added to either the photosensitive layer or the non-photosensitive layer. Regarding these, reference can be made to WO98 / 36322, EP803764A1, JP-A-10-186567, and 10-18568.

  In the present invention, each of the above layers may be applied by any method. Specifically, various coating operations including extrusion coating, slide coating, curtain coating, dip coating, knife coating, flow coating, or extrusion coating using a hopper of the type described in US Pat. No. 2,681,294. The extrusion coating or slide coating described in pages 399 to 536 of “LIQUID FILM COATING” (CHAPMAN & HALL, 1997) by Stephen F. Kistler and Petert M. Schweizer is preferably used. Slide coating is used. An example of the shape of the slide coater used for the slide coating is shown in FIG. 11b. 1 If desired, two or more layers may be simultaneously coated by the method described on pages 399 to 536 of the same document, the method described in US Pat. No. 2,761,791 and British Patent No. 837,095. can do.

  The organic silver salt-containing layer coating solution in the present invention is preferably a so-called thixotropic fluid. Regarding this technique, JP-A-11-52509 can be referred to. In the organic silver salt-containing layer coating solution of the present invention, the viscosity at a shear rate of 0.1S-1 is preferably 400 mPa · s or more and 100,000 mPa · s or less, more preferably 500 mPa · s or more and 20,000 mPa · s or less. . Further, at a shear rate of 1000S-1, it is preferably 1 mPa · s or more and 200 mPa · s or less, more preferably 5 mPa · s or more and 80 mPa · s or less.

  In the present invention, the technologies that can be used include EP80364A1, EP883022A1, WO98 / 36322, JP-A-56-62648, JP-A-58-62644, JP-A-9-43766, JP-A-9-281737, -297367, 9-304869, 9-31405, 9-329865, 10-10669, 10-62899, 10-69023, 10-186568, 10-90823 No. 10-1107103, No. 10-186565, No. 10-186567, No. 10-186567 to No. 10-186572, No. 10-197974, No. 10-197982, No. 10-197983, 10-197985 to 10-197987, 10-2070 No. 1, No. 10-207004, No. 10-221807, No. 10-282601, No. 10-288823, No. 10-288824, No. 10-307365, No. 10-312038, No. 10-339934 11-7100, 11-15105, 11-24200, 11-24201, 11-30201, 11-30832, 11-84574, 11-65021, 11-109547, 11-125880, 11-129629, 11-133536 to 11-133539, 11-133542, 11-133543, 11-223898, 11-352627, 11- 305377, 11-305378, 11-305384, 11-305380, 1-316435, 11-327076, 11-338096, 11-338098, 11-338099, 11-343420, Japanese Patent Application Nos. 2000-187298, 2000-10229, 2000 -47345, 2000-206642, 2000-98530, 2000-98531, 2000-112059, 2000-1112060, 2000-112104, 2000-1112064, 2000-171936 There are also publications of each issue.

  In the present invention, the heat-developable recording material obtained may be developed by any method, but is usually developed by raising the temperature of the heat-developable recording material exposed imagewise. The preferred development temperature is 80 to 250 ° C, more preferably 100 to 140 ° C. The development time is preferably 1 to 60 seconds, more preferably 5 to 30 seconds, and particularly preferably 10 to 20 seconds.

  A plate heater method is preferred as the heat development method. The plate heater type heat development method is preferably the method described in JP-A-11-133572, and a visible image is obtained by bringing the heat development recording material on which the latent image has been formed into contact with the heating means in the heat development section. In the heat development apparatus, the heating unit includes a plate heater, and a plurality of press rollers are disposed to face each other along one surface of the plate heater, and the press roller is disposed between the press roller and the plate heater. A thermal development apparatus that performs thermal development by passing a thermal development recording material. It is preferable to divide the plate heater into 2 to 6 stages and lower the temperature about 1 to 10 ° C. at the tip. Such a method is also described in Japanese Patent Application Laid-Open No. 54-30032, which can exclude moisture and organic solvent contained in the heat-developable recording material out of the system, and rapidly heat-developable recording. A change in the shape of the support of the heat-developable recording material due to the heating of the material can also be suppressed.

  In the present invention, the heat-developable recording material obtained may be exposed by any method, but a laser beam is preferred as the exposure light source. As the laser beam according to the present invention, a gas laser (Ar +, He—Ne), a YAG laser, a dye laser, a semiconductor laser and the like are preferable. A semiconductor laser and a second harmonic generation element can also be used. Red to infrared emission gas or semiconductor laser is preferable.

  As a medical laser imager provided with the exposure part and the heat development part, Fuji Medical Dry Laser Imager FM-DPL can be mentioned. Regarding FM-DPL, Fuji Medical Review No. 8, pages 39 to 55, and it goes without saying that these techniques are applied as a laser imager for heat-developable recording materials. Further, as a network system adapted to the DICOM standard, it can be applied as a heat development recording material for a laser imager in “ADnetwork” proposed by Fuji Medical System.

  In the present invention, the heat-developable recording material obtained forms a black-and-white image with a silver image, and is a heat-developable recording material for medical diagnosis, a heat-developable recording material for industrial photography, a heat-developable recording material for printing, and a heat developable for COM. It is preferably used as a recording material.

  (1) Preparation of PET support: PET having intrinsic viscosity IV = 0.66 was obtained using terephthalic acid and ethylene glycol according to a conventional method. After pelletizing this, after crystallization at 110-130 ° C. for 1 hour and 180 ° C. for 3.5 hours dehydration step, it is melted in a mixed state with blue dye, extruded from a T-die, and rapidly cooled. A stretched film was prepared. This was stretched longitudinally by 3.2 times using rolls having different peripheral speeds, and then stretched by 3.3 times with a tenter to obtain a support having a thickness of 175 μm.

(2) Undercoat layer coating: The obtained support was handled at a speed of 110 m / min, subjected to corona discharge treatment, coated on both sides with a wire bar coater, and then applied at 195 ° C. in a PAC drying zone. The first layer of the undercoat layer was provided so as to be dried for 2 seconds and to have the following dry coating amount per side. Table 1 shows the amount of wet coating.
-Styrene-butadiene copolymer latex 239.0 mg / m ²
2,4-dichloro-6-hydroxy -s- triazine sodium salt ^{5.8mg / m 2 · NaCl 1.6mg /} m 2
Next, after the corona discharge treatment is performed again on the coating layer, both sides are coated with a wire bar coater, and then dried at 185 ° C. for 20 seconds. Two layers were provided. Table 1 shows the amount of wet coating.
Gelatin (alkali treatment) 82.0mg / m ²
Dye (compound 1 below) 8.2 mg / m ²
Latex (the following compound 2) 20.4 mg / m ²
Surfactant (Compound 3 below) 3.7 mg / m ²
PMMA matting agent (average particle size 2.8 μm) 14.0 mg / m ²
Preservative (Compound 4 below) 0.2 mg / m ²
・ Acetic acid 0.6mg / m ²

（３）ハロゲン化銀感光層塗布
乳剤層塗布液の調製：水１リットル中に臭化カリ５ｇ、沃化カリ０．０５ｇ、ゼラチン３０ｇ、チオエーテルＨＯ（ＣＨ₂ ) ₂ Ｓ（ＣＨ₂ ) ₂ Ｓ（ＣＨ₂ ) ₂ ＯＨの５％水溶液２．５ccを添加し７３℃に保った溶液中へ、攪拌しながら硝酸銀８．３３ｇの水溶液と、臭化カリ５．９４ｇ、沃化カリ０．７２６ｇを含む水溶液とをダブルジェット法により４５秒間で添加した。続いて臭化カリ２．５ｇを添加したのち、硝酸銀量８．３３ｇを含む水溶液を７分３０秒かけて、添加終了時の流量が添加開始時の２倍となるように添加した。引き続いて硝酸銀１５３．３４ｇの水溶液と臭化カリと沃化カリの混合水溶液を、電位をｐＡｇ８．１に保ちながらコントロールダブルジェット法で２５分間で添加した。この時の流量は添加終了時の流量が、添加開始時の流量の８倍となるように加速した。添加終了後２Ｎのチオシアン酸カリウム溶液１５ccを添加し、さらに１％の沃化カリ水溶液５０ccを３０秒かけて添加した。このあと温度を３５℃に下げ、沈降法により可溶性塩類を除去したのち、４０℃に昇温してゼラチン６８ｇとフェノール２ｇ、トリメチロールプロパン７．５ｇを添加し、可性ソーダと臭化カリによりｐＨ６．５５、ｐＡｇ８．１０に調整した。温度を５６℃に昇温したのち、４−ヒドロキシ−６−メチル−１，３，３ａ，７−テトラザインデン１７５mgと下記の化学式５の増感色素を６２５mg添加した。１０分後にチオ硫酸ナトリウム５水和物５．５mgチオシアン酸カリ１６３mg、塩化金酸３．６mgを添加し、５分後に急冷して固化させた。得られた乳剤は全粒子の投影面積の総和の８０％が平均アスペクト比５以上の粒子からなっていた。

(3) Silver halide photosensitive layer coating Preparation of emulsion layer coating solution: 5 g of potassium bromide, 0.05 g of potassium iodide, 30 g of gelatin, thioether HO (CH ₂ ) ₂ S (CH ₂ ) ₂ S in 1 liter of water While stirring, an aqueous solution of 8.33 g of silver nitrate, 5.94 g of potassium bromide, and 0.726 g of potassium iodide were added to a solution maintained at 73 ° C. by adding _2.5 cc of a 5% aqueous solution of (CH ₂ ) ₂ OH. The aqueous solution was added in 45 seconds by the double jet method. Then, after adding 2.5 g of potassium bromide, an aqueous solution containing 8.33 g of silver nitrate was added over 7 minutes and 30 seconds so that the flow rate at the end of addition was twice that at the start of addition. Subsequently, an aqueous solution of 153.34 g of silver nitrate and a mixed aqueous solution of potassium bromide and potassium iodide were added over 25 minutes by the control double jet method while maintaining the potential at pAg 8.1. The flow rate at this time was accelerated so that the flow rate at the end of addition was 8 times the flow rate at the start of addition. After the addition, 15 cc of 2N potassium thiocyanate solution was added, and 50 cc of 1% potassium iodide aqueous solution was added over 30 seconds. After this, the temperature is lowered to 35 ° C., and soluble salts are removed by the precipitation method. Then, the temperature is raised to 40 ° C., 68 g of gelatin, 2 g of phenol, and 7.5 g of trimethylolpropane are added. The pH was adjusted to 6.55 and pAg 8.10. After raising the temperature to 56 ° C., 175 mg of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene and 625 mg of a sensitizing dye of the following chemical formula 5 were added. Ten minutes later, sodium thiosulfate pentahydrate 5.5 mg potassium thiocyanate 163 mg and chloroauric acid 3.6 mg were added, and after 5 minutes, the mixture was quenched and solidified. The obtained emulsion was composed of grains having an average aspect ratio of 5 or more in 80% of the total projected area of all grains.

The following chemicals were added to this emulsion per mole of silver halide to prepare a coating solution.
2,80-mg 2,6-bis (hydroxyamino) -4-diethylamino-1,3,5-triazine
・ Sodium polyacrylate (average molecular weight 41,000) 4.0g
20.0 g of copolymerized plasticizer having a composition ratio of ethyl acrylate / acrylic acid / methacrylic acid = 95/2/3
・ The following chemical formula 6 9.7 g
・ Nitron 50mg

（４）写真材料の作成：上記の乳剤層塗布液を前記の下塗塗布物の両面に同じように塗布し写真材料を得た。このようにして得られた写真材料の断面図を図２に示す。同図に示すように、ＰＥＴ支持体１の両面に易接着ＳＢＲ下塗層（下塗層の第１層）２、２が形成され、その両表面にゼラチン下塗層（下塗層の第２層）３、３が形成され、さらにその両表面にハロゲン化銀感光層として画像形成層４、４が形成される。

(4) Preparation of photographic material: The above emulsion layer coating solution was applied to both sides of the above-mentioned undercoat coating material in the same manner to obtain a photographic material. A sectional view of the photographic material thus obtained is shown in FIG. As shown in the figure, easy-adhesion SBR undercoat layers (first undercoat layer) 2 and 2 are formed on both surfaces of a PET support 1, and gelatin undercoat layers (undercoat layer first layers) are formed on both surfaces thereof. 2 layers) 3 and 3 are formed, and image forming layers 4 and 4 are formed as silver halide photosensitive layers on both surfaces thereof.

  (5) Evaluation of planar failure: The photographic material prepared as described above was evaluated for streak failure and repelling failure.

The evaluation of streak failure (failure that causes unevenness in the thickness of the wet film by incorporating bubbles or foreign matter into the secondary meniscus of the bar coating) was made by observation and classified as follows.
“×”: When the strength of the streak failure is at a level where the product is not possible, the length of the streak failure is 1000 m or more, or the occurrence frequency is high “△”… When the strength satisfies the product limit level, the length of occurrence of streak failure is about 100 to 1000 m, or the occurrence frequency is frequent, “○ △”… “x” “△” If the product acceptable level, or the occurrence length of streak failure is 100 m or less, or the occurrence frequency is sporadic, “◯”: the strength of streak failure is the product acceptable level, and the occurrence length of streak failure is 100 m or less, When satisfying almost no occurrence, repellency failures (failures caused by an increase in the surface tension of the coating solution) were evaluated by observation and classified as follows.
“○”: Almost no cissing that affects photographic performance.
“△”… Repelling that affects photographic performance is observed (several locations / 1000 m ² )
“×”… Repels frequently affecting photographic performance (several locations / 10 m ² )
The results of evaluation as described above are shown in Table 1.

表１から分かるように、乾燥時の塗工量を変えないでWet 塗布量を増加させると、スジ故障の面で塗布性能が向上する。これは、Wet 塗布量を増加させることによって、二次側メニスカス中の泡や異物が保持されなくなり、発生頻度が低下し、発生長が短くなるためである。そして、スジ故障の面では、Wet 塗布量が７．０ｍｌ／ｍ² 以上が好ましく、８．０ｍｌ／ｍ² 以上が好ましいという結果が得られた。

As can be seen from Table 1, increasing the wet coating amount without changing the coating amount during drying improves the coating performance in terms of streak failure. This is because by increasing the wet coating amount, bubbles and foreign matter in the secondary meniscus are not retained, the frequency of occurrence is reduced, and the generation length is shortened. In terms of streak failure, the result was that the wet coating amount was preferably 7.0 ml / m ² or more, and preferably 8.0 ml / m ² or more.

  On the other hand, when the wet coating amount increased, the coating performance decreased in terms of repelling failure. However, repelling failure was improved by increasing the amount of surfactant added to the undercoat layer coating solution.

Further, although not shown in Table 1, coating unevenness occurred by increasing the wet coating amount. Specifically, when the amount of wet coating exceeds 10 ml / m ² , coating unevenness acceptable to the product occurs, and when the amount of wet coating exceeds 30 ml / m ² , the product is unacceptable. Level uneven coating occurred.

From the above results, Wet coating amount is preferably from 7.0 ml / m ² or more 30 ml / m ² or ^{less, 8.0ml / m 2 10ml / m} 2 or less results in a more preferred are obtained.

Schematic diagram showing the configuration of a bar coater to which the present invention is applied. The figure which shows the cross section of the photosensitive material obtained in the Example

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... PET support body 2 ... Easily-adhesive SBR subbing layer 3 ... Gelatin subbing layer 4 ... Image forming layer

Claims (3)

In the coating method of forming the undercoat layer on the support and applying the undercoat layer of the silver halide photosensitive material to form the silver halide photosensitive layer on the undercoat layer,
The subbing layer as well as a bar coater, a method of coating a subbing layer of the silver halide light-sensitive material, characterized by a Wet coating amount at that time below 7.0 ml / m ² or more 30 ml / m ² . The subbing layer with a plurality of layers formed by a bar coater, a halogen according to claim 1, characterized in that the Wet coating amount of time the application of each layer below 7.0 ml / m ² or more 30 ml / m ² A method for applying an undercoat layer of a silver halide light-sensitive material.   3. The method of applying an undercoat layer of a silver halide photosensitive material according to claim 1, wherein the undercoat layer contains a solid disperse dye.

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