JP4021586B2 - Photothermographic material - Google Patents

Description

【０２３８】
【化２】

【０２３９】
【化３】

【０２４０】
（各層単膜の破断伸長度の測定）
各層の塗布液をテフロンベース上に乾燥膜厚が25.0μｍとなるように塗布した。それを30℃で乾燥後、塗布膜のみをテフロンベースから剥がし、単膜を調製した。次にこの単膜の破断伸長度を以下のように測定した。
所定の大きさ（５mm×50mm）に膜を切り、熱現像温度（120℃）に５分間調温する。
引っ張り試験器（（株）オリエンテック製：引っ張り試験装置RTM-100）にサンプルを装着し、引っ張り速度100mm/分で膜が破断するまで引っ張った。
破断伸長度は
（Ａ−Ｂ）／Ｂ×１００％
Ａ：引っ張り試験器の固定具間のサンプル長で引っ張り後、破断したときの長さ
Ｂ：引っ張り試験器の固定具間のサンプル長で引っ張る前の長さで計算した。
【０２４１】
（亀裂の評価）
作製した熱現像感光材料の試料を25℃60％RH（相対湿度）条件下で乳剤面側に先端が0.5mmの半円球となっているステンレス針にて50gの荷重をかけて1cm／秒の速度でひっかいた後、下記レーザー感光計を用い、胸部診断画像を露光した。その後、特願平９−２２９６８４号実施例の図１に記載のプレートヒータ方式の熱現像装置１０で１２０℃、２０秒の熱現像を行い、目視で評価した。但し、金属メッシュと活性炭のフィルターを使い、臭いを消した。
【０２４２】

【０２４３】
○：画像部の白抜けも、保護層及び画像形成層の亀裂もなく良好
△：画像部の白抜けはないが、保護層及び画像形成層に少し亀裂がある。
×：保護層及び画像形成層に亀裂があり、画像部に白抜けもある（問題であ
る）
【０２４４】
【表１】

【０２４５】
表１から本発明の効果は明らかである。また、本発明の試料は熱亀裂防止が良好であった。
【０２４６】
実施例２
実施例１の試料１０２と同様に、但し乳剤層をＳＢＲラテックスの代わりに以下のラテックスＬｂ１とＬｃ１（ともに平衡含水率2wt%未満）を用いて試料を作成した。
【０２４７】
（Ｌｂ１の合成）
ガラス製オートクレーブ（耐圧硝子工業（株）製TEM-V1000）にスチレン140g、蒸留水280g、界面活性剤（サンデットＢＬ（三洋化成（株）製））4.44g 、アクリル酸6gを入れ、窒素気流下で１時間撹拌した。その後2-エチルヘキシルアクリレート54g を添加し、70℃まで昇温した。次に過硫酸アンモニウム水溶液（5wt%）を20g 添加し、そのまま10時間撹拌した。その後、反応容器の温度を室温まで下げてスチレン−アクリルラテックスを得た。このラテックスに１Ｎのアンモニア水溶液を添加してｐＨを7.5に調整した。
【０２４８】
こうして平均粒径98nm、濃度42wt%のラテックス(Lb1)を得た。ポリマーの25℃60%RH下での平衡含水率は0.7wt%であった。
【０２４９】
（Ｌｃ１の合成）
ガラス製オートクレーブ（耐圧硝子工業（株）製TEM-V1000）にメチルメタクリレート126g、蒸留水280g、界面活性剤（サンデットＢＬ（三洋化成（株）製））8.2g、アクリル酸4gを入れ、窒素気流下で１時間撹拌した。その後エチルアクリレート70g を添加し、60℃まで昇温した。次に過硫酸カリウム水溶液（5wt%）を20g 添加し、そのまま10時間撹拌した。その後、反応容器の温度を室温まで下げてアクリルラテックスを得た。このラテックスに１Ｎのアンモニア水溶液を添加してｐＨを7.5に調整した。
【０２５０】
こうして平均粒径101nm、濃度44wt%のラテックス(Lc1)を得た。ポリマーの25℃60%RH下での平衡含水率は0.7wt%であった。
【０２５１】
Ｌｂ１を用いたものを試料２０１、Ｌｃ１を用いたものを試料２０２とする。これらの試料においても実施例１と同様の結果を得た。
【０２５２】
実施例３
実施例１と同様に、但し、ＳＢＲラテックスは、合成の最終工程でＮＨ₄ＯＨとＮａＯＨ（１：１（重量比)）でｐＨ＝８．０にｐＨ調整し、ＵＦ精製しないものを用いた。効果は実施例１と同様であった。
【０２５３】
【発明の効果】
本発明により、熱現像時の亀裂・白抜けの発生を防止できる。
【図面の簡単な説明】
【図１】プレートヒータ方式の熱現像部の横断面概略図である。
【図２】プレートヒータ方式の熱現像部の横断面概略図である。
【符号の説明】
１８ 熱現像部
１２０ プレートヒータ
１２２ 押えローラ
１３０ 駆動ローラ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photothermographic material.
[0002]
[Prior art]
In recent years, in the medical field, reduction of waste processing liquid has been strongly desired from the viewpoint of environmental protection and space saving. Therefore, photosensitive heat for medical diagnosis and photographic technology that can be efficiently exposed by a laser image setter or laser imager and can form a clear black image having high resolution and sharpness. There is a need for techniques relating to developed photographic materials. These photosensitive photothermographic materials eliminate the use of solution processing chemicals and can provide customers with a simpler heat development processing system that does not damage the environment.
[0003]
Although there is a similar requirement in the field of general image forming materials, medical images are required to have high image quality with excellent sharpness and graininess because they are required to be finely drawn, and are cooled from the viewpoint of ease of diagnosis. There is a feature that a black tone image is preferred. At present, various hard copy systems using pigments and dyes such as inkjet printers and electrophotography are distributed as general image forming systems. However, there is no satisfactory output system for medical images.
[0004]
On the other hand, thermal imaging systems using organic silver salts are disclosed in, for example, the specifications of U.S. Pat. Nos. 3,152,904 and 3,457,075 and B.I. "Thermally Processed Silver Systems" by Shely (Imaging Processes and Materials Neblette 8th Edition, Sturge, V. Walworth (Walworth, A. Shepp, edited, page 2, 1996). In particular, the photothermographic material generally contains a catalytically active amount of a photocatalyst (eg, silver halide), a reducing agent, a reducible silver salt (eg, an organic silver salt), and a color tone that controls the color tone of silver if necessary. And a photosensitive layer dispersed in a binder matrix. The photothermographic material is heated to a high temperature (for example, 80 ° C. or higher) after image exposure, and blackened by a redox reaction between silver halide or a reducible silver salt (functioning as an oxidizing agent) and a reducing agent. Form a silver image. The oxidation-reduction reaction is promoted by the catalytic action of the latent image of silver halide generated by exposure. Therefore, a black silver image is formed in the exposure area.
[0005]
Conventionally, an organic solvent-based photosensitive layer using polyvinyl butyral (PVB) as a binder has been used as the photothermographic material, but it can be applied with an aqueous solvent from the viewpoint of liquid preparation / coating operation and equipment. It has been desired. In order to solve such a problem, Japanese Patent Application Laid-Open No. 10-186567 proposed a method in which a photosensitive layer is coated with a styrene-butadiene polymer dispersed in water. However, when a protective layer using gelatin is used on the photosensitive layer using such a binder, cracks extending to the protective layer and the image forming layer occur particularly in the image area when heat-developed. It was found that white spots would occur.
[0006]
[Problems to be solved by the invention]
The present invention is to prevent the occurrence of cracks during heat development.
[0007]
[Means for Solving the Problems]
The present invention has been achieved by the following means.
[0010]
(1) A photosensitive layer containing at least a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on the support, and at least one non-photosensitive layer thereon A photothermographic material having a water-soluble polymer and a polymer having a glass transition temperature Tg of from 20 ° C. to 80 ° C. in the at least one non-photosensitive layerPolymer having Tg of 20 ° C or higher and 80 ° C or lowerThe photothermographic material is characterized in that the content of is not less than 5 wt% and not more than 50 wt% of the total binder of the entire non-photosensitive layer.
(2) A photosensitive layer containing at least a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on the support, and at least one non-photosensitive layer thereon. The photothermographic material according to (1), wherein the at least one non-photosensitive layer has a breaking elongation at a heat development temperature of 5% or more and 25% or less.
[0011]
(3) The non-photosensitive layer is coated with an aqueous solvent,Polymer having Tg of 20 ° C or higher and 80 ° C or lowerThe photothermographic material according to (1) or (2), wherein is contained in the aqueous solvent as a latex.
[0012]
(4) 50% by weight or more of the total binder of the photosensitive layer is a polymer having an equilibrium water content of 2% by weight or less at 25 ° C. and 60% RH, and the photosensitive layer is coated with an aqueous solvent,Polymer having Tg of 20 ° C or higher and 80 ° C or lowerThe photothermographic material according to any one of (1) to (3), wherein is contained in the aqueous solvent as a latex.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
The photothermographic material in the invention has at least one non-photosensitive layer on the photosensitive layer. If the non-photosensitive layer has a breaking elongation of 5% or more and 25% or less at the heat development temperature, the non-photosensitive layer is taken out as a single film and subjected to the following breaking elongation test under the conditions of the heat development temperature. 5% or more and 25% or less.
[0014]
(Measurement of elongation at break of each layer single film)
The coating solution for each layer was applied on a Teflon base so that the dry film thickness was 25.0 μm. After drying it at 30 ° C., only the coating film was peeled off from the Teflon base to prepare a single film. Next, the elongation at break of this single membrane was measured as follows.
(1) A film is cut into a predetermined size (5 mm × 50 mm), and the temperature is adjusted to a heat development temperature (120 ° C.) for 5 minutes.
(2) The sample was mounted on a tensile tester and pulled at a pulling speed of 100 mm / min until the membrane broke.
(3) Breaking elongation is
(AB) / B × 100%
A: Length when the sample breaks after being pulled with the sample length between the fixtures of the tensile tester
B: Length before pulling with the sample length between the fixtures of the tensile tester
Calculated with
[0015]
In the present invention, the elongation at break is preferably 10% or more and 15% or less.
[0016]
The water-soluble polymer contained in the non-photosensitive layer of the present invention (hereinafter sometimes referred to as a surface protective layer) may be any, but a polymer having a carboxylic acid residue or polyvinyl alcohol is preferred.
Polymers having a carboxyl residue include natural polymers (gelatin, alginic acid, etc.), modified natural polymers (carboxymethylcellulose, phthalated gelatin, etc.), synthetic polymers (polymethacrylate, polyacrylate, polyalkylmethacrylate / acrylate copolymer). , Polystyrene / polymethacrylate copolymer, etc.). The carboxy residue content of such polymers is 1 x 10 per 100g of polymer.^-2It is preferable that the amount is not less than mol and not more than 1.4 mol. In addition, the carboxylic acid residue may form a salt with an alkali metal ion, an alkaline earth metal ion, an organic cation or the like.
[0017]
As polyvinyl alcohol (PVA), PVA-105 of a completely saponified product [polyvinyl alcohol (PVA) content 94.0 wt% or more, saponification degree 98.5 ± 0.5 mol%, sodium acetate content 1.5 wt% or less , Volatile matter 5.0 wt% or less, viscosity (4 wt%, 20 ° C.) 5.6 ± 0.4 CPS], partially saponified PVA-205 [PVA content 94.0 wt%, saponification degree 88.0 ± 1. 5 mol%, sodium acetate content 1.0 wt%, volatile content 5.0 wt%, viscosity (4 wt%, 20 ° C.) 5.0 ± 0.4 CPS], modified polyvinyl alcohol MP-102, MP-202, MP -203, R-1130, R-2105 (above, trade names manufactured by Kuraray Co., Ltd.) and the like.
In the present invention, gelatin is particularly preferred.
[0018]
Amount of water-soluble polymer applied to the surface protective layer (per layer) (support 1m)²As per) 0.3g / m²~ 4.0g / m²Is preferred, 0.3 g / m²~ 2.0 g / m²Is more preferable.
Such a water-soluble polymer can be dissolved in an aqueous solvent and applied.
[0019]
In order to make the elongation at break at the heat development temperature of the surface protective layer 5% or more and 25% or less, the surface protective layer is adjusted by containing the water-soluble polymer and a polymer having a glass transition temperature Tg of 20 ° C to 80 ° C. can do. A preferable Tg is 40 ° C. or higher and 70 ° C.
These Tg polymers can be used for coating by containing them in an aqueous solvent as a latex.
[0020]
Specific examples of the latex of the polymer having Tg = 20 ° C. or more and 80 ° C. or less used in the present invention include the following. Below, it represents using a raw material monomer, and the numerical value in a parenthesis is weight%. The glass transition temperature (Tg) is shown in [].
E-1; Latex of -St (50) -BA (42) -AA (4) -NMAM (4)-[Tg = 21 ° C.]
Latex of E-2; -MMA (59) -2EHA (26) -St (9) -AA (1)-[Tg = 47 ° C.]
E-3; Latex of -MMA (70) -EA (27) -AA (3)-[Tg = 59 ° C.]
E-4; Latex of -MMA (70) -2EHA (20) -St (5) -AA (5)-[Tg = 59 ° C.]
E-5; Latex of -St (50) -Bu (20) -MAA (30)-[Tg = 40 ° C.]
E-6; Latex of -St (80) -Bu (17) -AA (3)-[Tg = 47 ° C]
E-7; Latex of -St (75) -Bu (24) -AA (1)-[Tg = 29 ° C]
E-8; Latex of -St (60) -Bu (30) -DVB (3) -MAA (7)-[Tg = 23 ° C.]
E-9; Latex of -St (70) -Bu (25) -DVB (2) -AA (3)-[Tg = 30 ° C.]
Latex of E-10; -VC (50) -MMA (20) -EA (20) -AN (5) -AA (5)-[Tg = 60 ° C.]
E-11; latex of VDC (35) -MMA (30) -EA (5) -MAA (30)-[Tg = 64 ° C.]
Latex of E-12; -Et (25) -MAA (75)-[Tg = 41 ° C.]
E-13; Latex of -St (70) -2EHA (27) -AA (3) [Tg = 43 ° C]
E-14; Latex of -MMA (63) -EA (35) -AA (2)-[Tg = 47 ° C.]
Latex of E-15; -MMA (59) -St (9) -2EHA (26) -HEMA (5) -AA (1)-[Tg = 47 ° C.]
E-16; Latex of -MMA (44) -St (9) -BA (40) -HEMA (5) -AA (2)-[Tg = 20 ° C.]
E-17; latex of MMA (59) -St (9) -BA (25) -HEMA (5) -AA (2)-[Tg = 47 ° C.]
E-18; Latex of -MMA (64) -St (9) -BA (20) -HEMA (5) -AA (2)-[Tg = 57 ° C.]
Latex of E-19; -MMA (69) -St (9) -BA (15) -HEMA (5) -AA (2)-[Tg = 68 ° C.]
E-20; latex of MMA (80) -St (9) -BA (10) -HEMA (5) -AA (2)-[Tg = 80 ° C.]
[0021]
On the other hand, examples of latexes other than Tg = 20 ° C. to 80 ° C. not included in the present invention include the following.
Latex of EM-1; -EA (100)-[Tg = -24 ° C.]
Latex of EM-2; -MMA (70) -MAA (23) -AA (2) -NMAM (5)-[Tg = 131 ° C.]
EM-3; Latex of -St (50) -Bu (47) -MAA (3)-[Tg = -17 ° C]
Latex of EM-4; -St (67) -Bu (30) -AA (3)-[Tg = 15 ° C.]
Latex of EM-5; -VDC (85) -MMA (5) -EA (5) -MAA (5)-[Tg = -7 ° C.]
Latex of EM-6; -Et (90) -MAA (10)-[Tg = −114 ° C.]
[0022]
The abbreviations for the above structures represent the following monomers. MMA; methyl methacrylate, EA; ethyl acrylate, MAA; methacrylic acid, 2EHA; 2 ethyl hexyl acrylate, St; styrene, Bu; butadiene, AA; acrylic acid, DVB; divinylbenzene, VC; vinyl chloride, AN; acrylonitrile, VDC; Vinylidene chloride, Et; Ethylene, IA; Itaconic acid, NMAM; N-methylolacrylamide.
[0023]
These polymers having a Tg of 20 ° C. or more and 80 ° C. or less may be used alone as a polymer latex, or two or more of them may be blended as necessary.
[0024]
The polymer latex of the present invention is prepared by a generally well-known emulsion polymerization method, and the preferred particle size range is 0.001 to 1.0 μm, particularly preferably 0.01 to 0.5 μm. In the oxidative polymerization method, the monomer is emulsified in water or a mixed solvent of water and water-miscible organic solvent (for example, methanol, ethanol, acetone, etc.) using at least one emulsifier, and a radical polymerization initiator is generally used. It is carried out at a temperature of 30 ° C to about 100 ° C, preferably 40 ° C to about 90 ° C. The amount of the organic solvent miscible with water is 0 to 100%, preferably 0 to 50%, by volume with respect to water. The polymerization reaction is usually carried out using 0.05 to 5% by weight of a radical polymerization initiator and optionally 0.1 to 10% by weight of an emulsifier based on the monomer to be polymerized. Examples of polymerization initiators include azobis compounds, peroxides, hydroperoxides, redox solvents such as potassium persulfate, ammonium persulfate, tert-butyl peroctoate, benzoyl peroxide, isopropyl carbonate, 2,4-dichloro. Examples include benzyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, dicumyl peroxide, 2,2′-azobisisobutyrate, 2,2′-azobis (2-amidinopropane) hydrochloride.
[0025]
Examples of the emulsifier include an anionic, cationic, amphoteric, and nonionic surfactant, and a water-soluble polymer. For example, sodium laurate, sodium dodecyl sulfate, 1-octoxycarbonylmethyl-1-octoxycarbonyl sodium methanesulfonate, sodium laurylnaphthalenesulfonate, sodium laurylbenzenesulfonate, sodium lauryl phosphate, cetyltrimethylammonium chloride, dodecyltri Examples include methyleneammonium chloride, N-2-ethylhexylpyridinium chloride, polyoxyethylene nonylphenyl ether, polyoxyethylene sorbitan lauryl ester, polyvinyl alcohol, an emulsifier described in JP-B-53-6190, and a water-soluble polymer. In emulsion polymerization, it goes without saying that the polymerization initiator, concentration, polymerization temperature, reaction time, etc. can be varied widely and easily according to the purpose. In addition, the emulsion polymerization reaction may be performed by adding the monomer surfactant and the medium in a container in advance and adding an initiator, or polymerizing while adding a part or all of each component dropwise as necessary. May be performed.
[0026]
When the surface protective layer has a multilayer structure of two or more layers (preferably 2 to 4 layers, more preferably 2 to 3 layers), a layer coated using such a polymer latex having a Tg of 20 ° C. to 80 ° C. There should be at least one layer.
[0027]
The total amount of binder in the surface protective layer is 0.5 to 10 g / m in total when the surface protective layer is two or more layers.²1-5 g / m²Is more preferable.
The polymer of the present invention is 5 wt% or more and 50 wt% or less in the total binder in the surface protective layer (in the case where there are a plurality of layers, the total includes a water-soluble polymer, a polymer having a Tg of 20 ° C to 80 ° C and other polymers) It is preferable to contain 10 wt% or more and 40 wt% or less.
[0028]
Any adhesion preventing material may be used as the surface protective layer of the present invention. Examples of anti-adhesion materials include wax, silica particles, styrene-containing elastomeric block copolymers (eg, styrene-butadiene-styrene, styrene-isoprene-styrene), cellulose acetate, cellulose acetate butyrate, cellulose propionate, and these There is a mixture. In addition, a crosslinking agent for crosslinking, a surfactant for improving coating properties, and the like may be added to the surface protective layer.
[0029]
For the image forming layer or the surface protective layer in the present invention, a light absorbing material and a filter dye as described in US Pat. Nos. 3,253,921, 2,274,782, 2,527,583 and 2,956,879 should be used. Can do. For example, a dye can be mordanted as described in US Pat. No. 3,282,699. The amount of filter dye used is preferably an absorbance at an exposure wavelength of 0.1 to 3.0, particularly preferably 0.2 to 1.5.
[0030]
The image-forming layer or surface protective layer in the present invention includes matting agents such as polymer beads including starch, titanium dioxide, zinc oxide, silica, and beads of the type described in US Pat. Nos. 2,992,101 and 2,701,245. Can be contained.
[0031]
In the present invention, a matting agent may be added to the surface protective layer for various purposes such as improving transportability. The matting agent is generally fine particles of an organic or inorganic compound that is insoluble in water. Any matting agent can be used.For example, organic matting agents described in U.S. Pat.Nos. 1,939,213, 2,701,245, 2,322,037, 3,262,782, 3,539,344, 3,767,448, etc. Those well known in the art such as the inorganic matting agents described in the respective specifications such as 1,260,772, 2,192,241, 3,257,206, 3,370,951, 3,523,022, and 3,769,020 can be used. For example, specific examples of organic compounds that can be used as matting agents include water-dispersible vinyl polymers such as polymethyl acrylate, polymethyl methacrylate, polyacrylonitrile, acrylonitrile-α-methylstyrene copolymer, polystyrene. , Styrene-divinylbenzene copolymer, polyvinyl acetate, polyethylene carbonate, polytetrafluoroethylene, etc. Examples of cellulose derivatives include methylcellulose, cellulose acetate, cellulose acetate propionate, etc. Examples of starch derivatives include carboxy starch, carboxynitrophenyl Preferably used for starch, urea-formaldehyde-starch reactants, gelatin hardened with known hardeners and hardened gelatin into cocapsulated hardened microcapsules Can be. As examples of the inorganic compound, silicon dioxide, titanium dioxide, magnesium dioxide, aluminum oxide, barium sulfate, calcium carbonate, silver chloride desensitized by a known method, silver bromide, glass, diatomaceous earth, and the like can be preferably used. The above matting agents can be used by mixing different kinds of substances as required. The size and shape of the matting agent are not particularly limited, and those having an arbitrary particle size can be used. In the practice of the present invention, those having a particle size of 0.1 μm to 30 μm are preferably used, and those having an average particle size of 2 μm to 10 μm are more preferable. Further, the particle size distribution of the matting agent may be narrow or wide. On the other hand, since the matting agent greatly affects the haze and surface gloss of the light-sensitive material, the particle size, shape, and particle size distribution can be brought into a state as required by preparing the matting agent or mixing a plurality of matting agents. preferable.
[0032]
Matting agent is photosensitive material 1m²When expressed as a coating amount per unit, preferably 1 to 400 mg / m², More preferably 5 to 300 mg / m²It is.
The emulsion surface may have any mat degree as long as no stardust failure occurs, but the Beck smoothness is preferably from 50 seconds to 10,000 seconds, and particularly preferably from 80 seconds to 10,000 seconds.
[0033]
The organic silver salt that can be used in the present invention is relatively stable to light, but is 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 that forms a silver image when heated above. The organic silver salt may be any organic material containing a source capable of reducing silver ions. Such a non-photosensitive organic silver salt is described in paragraph Nos. 0048 to 0049 of JP-A No. 10-62899, page 18, line 24 to page 19, line 37 of European Patent Publication No. 080863A1. Yes. Silver salts of organic acids, particularly silver salts of long-chain aliphatic carboxylic acids (having 10 to 30, preferably 15 to 28 carbon atoms) are preferred. The organic silver salt can preferably constitute about 5 to 70 wt% of the image forming layer. Preferred organic silver salts include silver salts of organic compounds having a carboxyl group. Examples of these include, but are not limited to, silver salts of aliphatic carboxylic acids and silver salts of aromatic carboxylic acids. Preferred examples of the aliphatic carboxylic acid silver salt include silver behenate, silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, silver maleate and fumarate. Silver acid, silver tartrate, silver linoleate, silver butyrate and silver camphor, mixtures thereof, and the like.
[0034]
Although there is no restriction | limiting in particular as a shape of the organic silver salt which can be used for this invention, In the present invention, scaly organic silver salt is preferable. In the present invention, the scaly organic silver salt is defined as follows. The organic acid silver salt was observed with an electron microscope, the shape of the organic acid silver salt particle was approximated to a rectangular parallelepiped, and the sides of the rectangular parallelepiped were designated a, b, and c from the shortest side (c was the same as b). Then, the shorter numerical values a and b are calculated, and x is obtained as follows.
x = b / a
[0035]
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.
[0036]
In the flake shaped particle, a can be regarded as a thickness of a tabular particle having a main plane with b and c as sides. The average of a is preferably 0.01 μm or more and 0.23 μm, more preferably 0.1 μm or more and 0.20 μm or less. The average of c / b is preferably 1 or more and 6 or less, more preferably 1.05 or more and 4 or less, further preferably 1.1 or more and 3 or less, and particularly preferably 1.1 or more and 2 or less.
[0037]
The particle size distribution of the organic silver salt is preferably monodispersed. Monodispersion is preferably 100% or less, more preferably 80% or less, and even more preferably 50% of the value obtained by dividing the standard deviation of the lengths of the short and long axes by the short and long axes, respectively. It is as follows. The method for measuring the shape of the organic silver salt can be determined from a transmission electron microscope image of the organic silver salt dispersion. Another method for measuring monodispersity is to obtain the standard deviation of the volume-weighted average diameter of the organic silver salt, and the percentage (coefficient of variation) of the value divided by the volume-weighted average diameter is preferably 100% or less, more Preferably it is 80% or less, more preferably 50% or less. As a measuring method, for example, it is obtained from the particle size (volume weighted average diameter) obtained by irradiating the organic silver salt dispersed in the liquid with laser light and obtaining the autocorrelation function with respect to the temporal change of the fluctuation of the scattered light. Can do.
[0038]
The organic acid silver used in the present invention is prepared by reacting a silver nitrate with a solution or suspension of an alkali metal salt (including Na salt, K salt, Li salt, etc.) of the organic acid shown above. The organic acid alkali metal salt of the present invention is obtained by subjecting the organic acid to an alkali treatment. The organic acid silver of the present invention can be run batchwise or continuously in any suitable container. Stirring in the reaction vessel can be performed by any stirring method depending on the required properties of the particles. The organic acid silver is prepared by adding a silver nitrate aqueous solution gradually or rapidly to a reaction vessel containing an organic acid alkali metal salt solution or suspension, or an organic acid prepared in advance in a reaction vessel containing a silver nitrate aqueous solution. Any of the method of adding an alkali metal salt solution or suspension gradually or rapidly, and the method of simultaneously adding an aqueous silver nitrate solution and an organic acid alkali metal salt solution or suspension to a reaction vessel are preferably used. Can do.
[0039]
The silver nitrate aqueous solution and the organic acid alkali metal salt solution or suspension can be used at any concentration for controlling the particle size of the organic acid silver to be prepared, and can be added at any addition rate. As a method for adding the silver nitrate aqueous solution and the organic acid alkali metal salt solution or suspension, it can be added by a method of adding at a constant addition rate, an accelerated addition method or a slow addition method by an arbitrary time function. Moreover, you may add to a liquid level with respect to a reaction liquid, and may add in a liquid. In the case of a method in which a silver nitrate aqueous solution and an organic acid alkali metal salt solution or suspension prepared in advance are simultaneously added to the reaction vessel, either the silver nitrate aqueous solution or the organic acid alkali metal salt solution or suspension is preceded. Although it can be added, it is preferable to add the silver nitrate aqueous solution in advance. The leading degree is preferably 0 to 50 vol%, particularly preferably 0 to 25 vol% of the total addition amount. Further, as described in JP-A-9-27643 and the like, a method of adding while controlling the pH or silver potential of the reaction solution during the reaction can be preferably used.
[0040]
The pH of the silver nitrate aqueous solution or organic acid alkali metal salt solution or suspension added can be adjusted according to the required properties of the particles. Any acid or alkali can be added to adjust the pH. Also, depending on the required properties of the particles, for example, the temperature in the reaction vessel can be arbitrarily set for controlling the particle size of the organic acid silver to be prepared, but the silver nitrate aqueous solution or organic acid alkali metal salt solution to be added Alternatively, the suspension can be prepared at any temperature. The organic acid alkali metal salt solution or suspension is preferably heated and kept at 50 ° C. or higher in order to ensure fluidity of the liquid.
[0041]
The organic acid silver used in the present invention is preferably prepared in the presence of a tertiary alcohol. The tertiary alcohol used in the present invention preferably has a total carbon number of 15 or less, particularly preferably 10 or less. Examples of preferred tertiary alcohols include tert-butanol, but the present invention is not limited thereto.
[0042]
The timing of addition of the tertiary alcohol used in the present invention may be any timing during the preparation of the organic acid silver, but it is preferably added during the preparation of the organic acid alkali metal salt to dissolve and use the organic acid alkali metal salt. . In addition, the amount of tertiary alcohol used in the present invention is H as a solvent in the preparation of organic acid silver.₂Although it can be arbitrarily used within a range of 0.01 to 10 by weight with respect to O 2, a range of 0.03 to 1 is preferred.
[0043]
In the present invention, a preferred scaly organic acid silver salt is prepared by reacting an aqueous solution containing a water-soluble silver salt and an aqueous third alcohol solution containing an organic acid alkali metal salt in a reaction vessel (the organic acid is added to the solution in the reaction vessel). A step of adding a third alcohol aqueous solution containing an alkali metal salt.) (Preferably an aqueous solution containing a water-soluble silver salt previously added or an aqueous solution containing a water-soluble silver salt) Is added at the same time as the third alcohol aqueous solution containing the organic acid alkali metal salt without preceding, water or a mixed solvent of water and the third alcohol, as described later, and contains a water-soluble silver salt. Even when the aqueous solution is put in advance, water or a mixed solvent of water and a tertiary alcohol may be put in advance.) And the tertiary alcohol water containing the organic acid alkali metal salt to be added Are preferably prepared in a way that the temperature difference between the liquid and 20 ° C. or higher 85 ° C. or less.
[0044]
By maintaining such a temperature difference during the addition of the third alcohol aqueous solution containing the organic acid alkali metal salt, the crystal form or the like of the organic acid silver salt is preferably controlled.
[0045]
The water-soluble silver salt is preferably silver nitrate, and the water-soluble silver salt concentration in the aqueous solution is preferably 0.03 mol / liter or more and 6.5 mol / liter or less, more preferably 0.1 mol / liter or more and 5 mol / liter or less. The pH of this aqueous solution is preferably 2 or more and 6 or less, more preferably pH 3.5 or more and 6 or less.
[0046]
Moreover, the C4-C6 tertiary alcohol may be contained, In that case, it is 70% or less as a volume with respect to the whole volume of the aqueous solution of water-soluble silver salt, Preferably it is 50% or less. The temperature of the aqueous solution is preferably 0 ° C. or higher and 50 ° C. or lower, more preferably 5 ° C. or higher and 30 ° C. or lower. As described later, an aqueous solution containing a water-soluble silver salt and a third alcohol aqueous solution of an organic acid alkali metal salt Is preferably 5 ° C. or more and 15 ° C. or less.
[0047]
The alkali metal of the organic acid alkali metal salt is specifically Na or K. The organic acid alkali metal salt is prepared by adding NaOH or KOH to the organic acid. At this time, it is preferable that the amount of alkali is equal to or less than the equivalent amount of organic acid to leave unreacted organic acid. In this case, the amount of residual organic acid is 3 mol% or more and 50 mol% or less, preferably 3 mol% or more and 30 mol% or less with respect to 1 mol of all organic acids. Moreover, after adding an alkali more than desired amount, you may prepare by adding acids, such as nitric acid and a sulfuric acid, and neutralizing an excess alkali content.
[0048]
Further, the pH can be adjusted according to the required properties of the organic acid silver salt. For adjusting the pH, any acid or alkali can be used.
[0049]
Furthermore, an aqueous solution containing a water-soluble silver salt, a tertiary alcohol aqueous solution of an organic acid alkali metal salt, or a reaction vessel used in the present invention is represented by, for example, general formula (1) of JP-A-62-65035. Such compounds, water-soluble group-containing N heterocyclic compounds as described in JP-A No. 62-150240, inorganic peroxides as described in JP-A No. 50-101019, JP-A No. 51-78319 Sulfur compounds as described in JP-A No. 57-643, disulfide compounds as described in JP-A-57-643, hydrogen peroxide, and the like can be added.
[0050]
The third alcohol aqueous solution of the organic acid alkali metal salt of the present invention is preferably a mixed solvent of a C4-6 tertiary alcohol and water in order to obtain liquid uniformity. If the carbon number exceeds this, there is no compatibility with water, which is not preferable. Among tertiary alcohols having 4 to 6 carbon atoms, tert-butanol that is most compatible with water is most preferable. Alcohols other than tertiary alcohols are not preferred as described above because they have reducing properties and cause harmful effects when forming organic acid silver salts. The amount of the third alcohol used in the third alcohol aqueous solution of the organic acid alkali metal salt is 3% or more and 70% or less, preferably 5% or more, as a solvent volume with respect to the volume of water in the third alcohol aqueous solution. 50% or less.
[0051]
The concentration of the organic acid alkali metal salt in the third alcohol aqueous solution of the organic acid alkali metal salt used in the present invention is 7 wt% or more and 50 wt% or less as a weight ratio, preferably 7 wt% or more and 45 wt% or less. Preferably, it is 10 wt% or more and 40 wt% or less.
[0052]
The temperature of the third alcohol aqueous solution of the organic acid alkali metal salt added to the reaction vessel of the present invention is 50 ° C. or more for the purpose of keeping the temperature necessary to avoid the crystallization and solidification of the organic acid alkali metal salt. 90 ° C or lower is preferable, more preferably 60 ° C or higher and 85 ° C or lower is more preferable, and 65 ° C or higher and 85 ° C or lower is most preferable. Further, in order to control the temperature of the reaction to be constant, it is preferably controlled to be constant at a certain temperature selected from the above range.
[0053]
The organic acid silver salt of the present invention is obtained by i) a method in which a third alcohol aqueous solution of an organic acid alkali metal salt is added to an aqueous solution in which an aqueous solution containing a water-soluble silver salt is first present in the reaction vessel, or ii) 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 produced by a method (simultaneous addition method) in which there is a time when they are simultaneously added to a reaction vessel. In the present invention, the latter method in which the average grain size of the organic acid silver salt is controlled and the distribution is narrowed is preferred in view of narrowing the distribution. In that case, it is preferable that 30 vol% or more of the total addition amount is added at the same time, and more preferably 50 to 75 vol% is added at the same time. When adding any of these in advance, it is preferable to precede the solution of the water-soluble silver salt.
[0054]
In either case, if the liquid in the reaction vessel (the aqueous solution of the water-soluble silver salt added previously as described above or the aqueous solution of the water-soluble silver salt is not added previously, as described later, The temperature of the solvent in the reaction vessel is preferably 5 ° C. or higher and 75 ° C. or lower, more preferably 5 ° C. or higher and 60 ° C. or lower, and most preferably 10 ° C. or higher and 50 ° C. or lower. The temperature is preferably controlled to a certain temperature selected from the above temperatures throughout the entire reaction process, but it is also preferable to control with several temperature patterns within the above temperature range.
[0055]
In the present invention, the temperature difference between the third alcohol aqueous solution of the organic acid alkali metal salt and the liquid in the reaction vessel is preferably 20 ° C. or higher and 85 ° C. or lower, more preferably 30 ° C. or higher and 80 ° C. or lower. In this case, it is preferable that the temperature of the tertiary alcohol aqueous solution of the organic acid alkali metal salt is higher.
[0056]
Thereby, the rate at which the third alcohol aqueous solution of the high-temperature organic acid alkali metal salt is rapidly cooled in the reaction vessel and precipitated in a fine crystal form, and the rate at which the organic acid silver salt is chlorinated by the reaction with the water-soluble silver salt are preferably controlled, 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 can be further improved as a heat-developable material, particularly as a heat-developable photosensitive material.
[0057]
The reaction vessel may contain a solvent in advance, and water is preferably used as the solvent put in advance, but a mixed solvent with the third alcohol is also preferably used.
[0058]
An aqueous medium-soluble dispersion aid can be added to the aqueous solution of the organic acid alkali metal tertiary alcohol, the aqueous solution of the water-soluble silver salt, or the reaction solution of the present invention. Any dispersing aid may be used as long as it can disperse the formed organic acid silver salt. Specific examples conform to the description of the organic acid silver salt dispersion aid described below.
[0059]
In the method for preparing an organic acid silver salt of the present invention, it is preferable to perform a desalting / dehydrating step after the formation of the silver salt. The method is not particularly limited, and well-known and conventional means can be used. For example, known filtration methods such as centrifugal filtration, suction filtration, ultrafiltration, and floc forming water washing by a coagulation method, and supernatant removal by centrifugal sedimentation are also preferably used. Desalting / dehydration may be performed once or a plurality of times. Water may be added and removed continuously or separately. Desalting / dehydration is performed to such an extent that 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 or less. The lower limit of the conductivity in this case is not particularly limited, but is usually about 5 μS / cm.
[0060]
Furthermore, in order to improve the coating surface state of the photothermographic material, particularly the photothermographic material, an organic acid silver salt aqueous dispersion is obtained, converted into a high-speed flow at a high pressure, and then the pressure is lowered. It is preferable to re-disperse to form a fine water dispersion. The dispersion medium in this case is preferably water only, but may contain an organic solvent as long as it is 20 wt% or less.
[0061]
The method for finely dispersing the organic acid silver salt is known in the presence of a dispersing aid, such as known finer means (eg, high speed mixer, homogenizer, high speed impact mill, Banbury mixer, homomixer, kneader, ball mill, vibrating ball mill, planetary planet). A ball mill, an attritor, a sand mill, a bead mill, a colloid mill, a jet mill, a roller mill, a tron mill, and a high-speed stone mill) can be used for mechanical dispersion.
[0062]
When a photosensitive silver salt is allowed to coexist at the time of dispersion, the fog increases and the sensitivity is remarkably lowered. Therefore, it is more preferable that the photosensitive silver salt is not substantially contained at the time of dispersion. In the present invention, the amount of the photosensitive silver salt in the aqueous dispersion to be dispersed is 0.1 mol% or less with respect to 1 mol of the organic acid silver salt in the liquid, and positive addition of the photosensitive silver salt is performed. There is nothing.
[0063]
In the present invention, in order to obtain a uniform organic silver salt solid dispersion having a high S / N, a small particle size, and no agglomeration, the organic silver salt particles as an image forming medium are not damaged or heated at high temperatures. It is preferable to apply a large force uniformly. For this purpose, a dispersion method is preferred in which an aqueous dispersion composed of an organic silver salt and an aqueous dispersant is converted into a high-speed flow and then the pressure is dropped.
[0064]
In the present invention, for example, “dispersion rheology and dispersion technology” (Toshio Kajiuchi, Hiroki Arai, 1991, Shinyamasha) Publishing Co., Ltd., p357-403), “Progress of Chemical Engineering, Vol. 24” (Chemical Engineering Society, Tokai Branch, 1990, Sakai Shoten, p184-185), JP 59-49832 A, US Pat. No. 4,533,254 However, the redispersion method in the present invention contains at least an organic acid silver salt, as described in JP-A-8-137004, JP-A-8-238848, JP-A-2-261525, and JP-A-1-94933. After the aqueous dispersion is pressurized with a high-pressure pump or the like and sent into the pipe, it is passed through a narrow slit provided in the pipe, and then a fine pressure drop is caused in the dispersion by causing a rapid pressure drop. It is a method to perform a proper dispersion.
[0065]
For the high-pressure homogenizer to which the present invention relates, in general, (a) “shearing force” generated when the dispersoid passes through a narrow gap (about 75 μm to 350 μm) at high pressure and high speed, and (b) in a narrow space where the pressure is increased. It is considered that the impact force generated when the liquid-liquid collision or the wall collision occurs is not changed, and the cavitation force due to the subsequent pressure drop is further increased, and uniform and efficient dispersion is performed. In the past, this type of dispersing device includes a gorin homogenizer. In this device, the liquid to be dispersed sent at a high pressure is converted into a high-speed flow through a narrow gap on the cylindrical surface, and this force is applied to the surrounding wall surface. Colliding and emulsifying / dispersing 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-8-103642, which will be described later, and the like. Includes a Z-type chamber of a microfluidizer. The working pressure is generally 100-600kg / cm²The flow velocity is in the range of several m to 30 m / sec. In order to increase the dispersion efficiency, a high-speed flow portion is sawtoothed to increase the number of collisions has been devised. Typical examples of such devices include Gorin homogenizers, microfluidizers manufactured by Microfluidics International Corporation, microfluidizers manufactured by Mizuho Industry Co., Ltd., and nanomizers manufactured by Special Machine Industries Co., Ltd. . Also described in JP-A-8-238848, JP-A-8-103642 and USP4533254.
[0066]
In the organic acid silver salt of the present invention, it can be dispersed to a desired particle size by adjusting the flow rate, the differential pressure at the time of pressure drop and the number of treatments, but from the viewpoint of photographic characteristics and particle size, the flow rate is 200 m / Second to 600m / sec, differential pressure at pressure drop is 900 to 3000kg / cm²The flow rate is preferably 300 m / sec to 600 m / sec, and the differential pressure during pressure drop is 1500 to 3000 kg / cm.²More preferably, it is the range. The number of distributed processes can be selected as necessary. Usually, a range of 1 to 10 times is selected, but about 1 to 3 times is selected from the viewpoint of productivity. Increasing the temperature of such an aqueous dispersion under high pressure is not preferable from the viewpoint of dispersibility and photographic properties, and at high temperatures exceeding 90 ° C, the particle size tends to increase and fog tends to increase. is there. Accordingly, the present invention includes a cooling device in the process before the conversion to the high pressure and high speed flow, the process after the pressure drop, or both of these processes, and the temperature of such water dispersion is 5 by the cooling process. It is preferable that the temperature is maintained in the range of from 0C to 90C, more preferably in the range of from 5C to 80C, and particularly preferably in the range of from 5C to 65C. In particular, 1500 to 3000 kg / cm²It is effective to install the above cooling process at the time of high pressure dispersion in the above range. Depending on the required heat exchange amount, a cooling device using a static mixer for a double tube or triple tube, a multi-tube heat exchanger, a serpentine heat exchanger, or the like can be appropriately selected. In addition, in order to increase the efficiency of heat exchange, a suitable tube thickness, wall thickness, material, etc. may be selected in consideration of the operating pressure. The refrigerant used for the cooler is a heat exchanger such as 20 ° C. well water, 5-10 ° C. chilled water treated with a refrigerator, or -30 ° C. ethylene glycol / water, etc. as necessary. can do.
[0067]
When organic acid silver salt is made into solid fine particles using a dispersant, for example, polyacrylic acid, acrylic acid copolymer, maleic acid copolymer, maleic acid monoester copolymer, acryloylmethylpropanesulfone Synthetic anionic polymers such as acid copolymers, semi-synthetic anionic polymers such as carboxymethyl starch and carboxymethylcellulose, anionic polymers such as alginic acid and pectic acid, and the like described in JP-A-52-92716, WO88 / 04794, etc. Anionic surfactants, compounds described in Japanese Patent Application No. 7-350753, or known anionic, nonionic, cationic surfactants, other polyvinyl alcohol, polyvinyl pyrrolidone, carboxymethyl cellulose, hydroxypropyl cellulose, hydroxypropyl Known polymers such as methylcellulose, Alternatively, a polymer compound existing in nature such as gelatin can be appropriately selected and used.
[0068]
Dispersing aid is generally mixed with organic acid silver salt powder or wet cake organic acid silver salt before dispersion, and sent to the disperser as a slurry. It is good also as an organic acid silver salt powder or a wet cake by giving the heat processing and the process by a solvent in the combined state. The pH may be controlled with an appropriate pH adjusting agent before or after the dispersion.
[0069]
In addition to mechanical dispersion, it may be coarsely dispersed in a solvent by controlling the pH, and then finely divided by changing the pH in the presence of a dispersion aid. At this time, an organic acid solvent may be used as a solvent used for rough dispersion, and the organic solvent is usually removed after the formation of fine particles.
[0070]
The prepared dispersion is 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) by a hydrophilic colloid. You can also. In addition, a preservative can be added for the purpose of preventing the propagation of various bacteria during storage.
[0071]
The organic acid silver salt prepared by the method for preparing an organic acid silver salt of the present invention is dispersed in an aqueous solvent, mixed with a photosensitive silver salt aqueous solution, and supplied as a photosensitive image forming medium coating solution. It is preferable.
[0072]
Prior to the dispersion operation, the raw material liquid is roughly dispersed (preliminary dispersion). As a means for rough dispersion, known dispersion means (for example, high speed mixer, homogenizer, high speed impact mill, Banbury mixer, homomixer, kneader, ball mill, vibration ball mill, planetary ball mill, attritor, sand mill, bead mill, colloid mill, jet mill) , Roller mill, tron mill, high-speed stone mill). In addition to mechanical dispersion, it may be coarsely dispersed in a solvent by controlling the pH, and then finely divided by changing the pH in the presence of a dispersion aid. 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 formation of fine particles.
[0073]
The photosensitive silver salt aqueous solution is finely dispersed and then mixed to produce a photosensitive image forming medium coating solution. When a photothermographic material is produced using such a coating solution, a photothermographic material having low haze and low fog and high sensitivity can be obtained. On the other hand, when the photosensitive silver salt is coexisting when converted into a high-pressure and high-speed flow and dispersed, the fog rises and the sensitivity is remarkably lowered. When an organic solvent is used instead of water as the dispersion medium, haze increases, fogging increases, and sensitivity tends to decrease. On the other hand, if the conversion method in which a part of the organic silver salt in the dispersion is converted to a photosensitive silver salt is used instead of the method of mixing the aqueous photosensitive silver salt solution, the sensitivity is lowered.
[0074]
In the above, the aqueous dispersion dispersed by being converted to high pressure and high speed is substantially free of photosensitive silver salt, and its content is 0.1 mol% relative to the non-photosensitive organic silver salt. In the following, no positive photosensitive silver salt is added.
[0075]
The particle size (volume weighted average diameter) of the organic silver salt solid fine particle dispersion of the present invention is, for example, an autocorrelation function with respect to the temporal change of fluctuation of the scattered light by irradiating the solid fine particle dispersion dispersed in the liquid with laser light Can be obtained from the particle size (volume weighted average diameter) obtained. A solid fine particle dispersion having an average particle size of 0.05 μm to 10.0 μm is preferable. More preferably, the average particle size is 0.1 μm or more and 5.0 μm or less, and still more preferably the average particle size is 0.1 μm or more and 2.0 μm or less.
[0076]
The organic silver salt solid fine particle dispersion used in the present invention comprises at least an organic silver salt and water. The ratio of the organic silver salt to water is not particularly limited, but the ratio of the organic silver salt to the whole is preferably 5 to 50 wt%, particularly preferably 10 to 30 wt%. It is preferable to use the above-mentioned dispersing aid, but it is preferable to use the minimum amount in a range suitable for minimizing the particle size, and it is in the range of 1 to 30 wt%, particularly 3 to 15 wt%, based on the organic silver salt. Is preferred.
[0077]
In the present invention, it is possible to produce a photosensitive material by mixing an organic silver salt aqueous dispersion and a photosensitive silver salt aqueous dispersion, but the mixing ratio of the organic silver salt and the photosensitive silver salt can be selected according to the purpose. The ratio of the photosensitive silver salt to the organic silver salt is preferably in the range of 1 to 30 mol%, more preferably 3 to 20 mol%, particularly preferably 5 to 15 mol%. Mixing two or more organic silver salt aqueous dispersions and two or more photosensitive silver salt aqueous dispersions when mixing is a method preferably used for adjusting photographic characteristics.
[0078]
The organic silver salt of the present invention can be used in a desired amount, but the silver amount is 0.1 to 5 g / m.²Is more preferable, and more preferably 1 to 3 g / m.²It is.
[0079]
The photothermographic material of the present invention 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. Conventional photographic developers such as phenidone, hydroquinone and catechol are useful, but hindered phenol reducing agents such as bis (2-hydroxy-3-tert-butyl-5-methylphenyl) methane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 4,4-ethylidene-bis (2-tert-butyl-6-methylphenol), 1,1-bis (2-hydroxy-3,5-dimethylphenyl)- 3,5,5-trimethylhexane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane) are preferred. Such reducing agents are described in paragraph Nos. 0052 to 0053 of JP-A No. 10-62899 and page 7 line 34 to page 18 line 12 of European Patent Publication No. 0080374A1.
[0080]
The amount of reducing agent added is 0.01 to 5.0 g / m.²Is preferably 0.1 to 3.0 g / m²More preferably, it is contained in an amount of 5 to 50% by mole, more preferably 10 to 40% by mole based on 1 mole of silver on the surface having the image forming layer. The addition layer of the reducing agent may be any layer on the surface having the image forming layer. When it is added to a layer other than the image forming layer, it is preferably used in a larger amount of 10 to 50 mol% with respect to 1 mol of silver. The reducing agent may be a so-called precursor that is derivatized so as to have an effective function only during development.
[0081]
The reducing agent of the present invention may be added by any method such as a solution, a powder, or a solid fine particle dispersion. The solid fine particle dispersion is performed by a known finer means (for example, ball mill, vibration ball mill, sand mill, colloid mill, jet mill, roller mill, etc.). A dispersion aid may be used when dispersing the solid fine particles.
[0082]
The photosensitive silver halide used in the present invention is not particularly limited as a halogen composition, and silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver iodochlorobromide can be used. The distribution of the halogen composition in the grains may be uniform, the halogen composition may be changed stepwise, or may be continuously changed. Further, silver halide grains having a core / shell structure can be preferably used. A preferable structure is a 2- to 5-fold structure, and more preferably 2- to 4-fold core / shell particles can be used. A technique of localizing silver bromide on the surface of silver chloride or silver chlorobromide grains can also be preferably used.
[0083]
Methods for forming photosensitive silver halide are well known in the art. For example, methods described in Research Disclosure No. 17029 of June 1978 and U.S. Pat.No. 3,700,458 can be used. Specifically, a method is used in which a photosensitive silver halide is prepared by adding a silver supply compound and a halogen supply compound to gelatin or another polymer solution, and then mixed with an organic silver salt.
[0084]
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 further preferably 0.02 μm or more. 0.12 μm or less is preferable. The grain size referred to here is the volume of silver halide grains when the silver halide grains are cubic or octahedral so-called normal crystals, and other than normal crystals, such as spherical grains and rod-like grains. This refers to the diameter when an equivalent sphere is considered. When the silver halide grain is a tabular grain, it means the diameter when converted into a circular image having the same area as the projected area of the main surface.
[0085]
Examples of the shape of the silver halide grains include cubes, octahedrons, tabular grains, spherical grains, rod-shaped grains, and potato grains. In the present invention, cubic grains and tabular grains are particularly preferred. When tabular silver halide grains are used, the average aspect ratio is preferably 100: 1 to 2: 1, more preferably 50: 1 to 3: 1. Further, grains having rounded corners of silver halide grains can 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} surface, which has high spectral sensitizing 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 Miller index {100} plane is calculated by T.Tani; J.Imaging Sci., 29, 165 (1985) using the adsorption dependence of {111} plane and {100} plane in the adsorption of sensitizing dye. It can be determined by the method described.
[0086]
The photosensitive silver halide grain of the present invention contains 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, rhenium, ruthenium, osmium and iridium are preferable. One kind of these metal complexes may be used, or two or more kinds of complexes of the same metal and different metals may be used in combination. The preferred content is 1 x 10 per mole of silver^-9From mole to 1 × 10^-3The molar range is preferred, 1 × 10^-8From mole to 1 × 10^-FourA molar range is more preferred. As a specific metal complex structure, a metal complex having a structure described in JP-A-7-225449 can be used.
[0087]
As the rhodium compound used in the present invention, a water-soluble rhodium compound can be used. For example, a rhodium (III) halide compound or a rhodium complex salt having halogen, amines, oxalato, etc. as a ligand, for example, hexachlororhodium (III) complex salt, pentachloroacorodium (III) complex salt, tetrachlorodia Examples include a corodium (III) complex salt, a hexabromorhodium (III) complex salt, a hexaammine rhodium (III) complex salt, and a trizaratrodium (III) complex salt. These rhodium compounds are used by dissolving in water or an appropriate solvent, and are generally used in order to stabilize the rhodium compound solution, that is, an aqueous hydrogen halide solution (for example, hydrochloric acid, odorous acid, hydrofluoric acid). Etc.) or a method of adding an alkali halide (for example, KCl, NaCl, KBr, NaBr, etc.) can be used. Instead of using water-soluble rhodium, it is also possible to add another silver halide grain previously doped with rhodium and dissolve it at the time of silver halide preparation.
[0088]
The amount of these rhodium compounds added is 1 x 10 per mole of silver halide.^-8Mol ~ 5 × 10^-6The molar range is preferred, particularly preferably 5 × 10^-8Mol ~ 1 × 10^-6Is a mole.
[0089]
The addition of these compounds can be appropriately carried out at the time of production of the silver halide emulsion grains and at each stage before coating the emulsion, but it is particularly preferred that they are added during the formation of the emulsion and incorporated into the silver halide grains. .
[0090]
Rhenium, ruthenium and osmium used in the present invention are added in the form of water-soluble complex salts described in JP-A-63-2042, JP-A-1-285941, JP-A-2-20852, JP-A-2-20855, etc. The Particularly preferred is a hexacoordination complex represented by the following formula.
[ML₆]^n-
Here, M represents Ru, Re or Os, L represents a ligand, and n represents 0, 1, 2, 3 or 4.
[0091]
In this case, the counter ion has no significance and ammonium or alkali metal ions are used.
[0092]
Preferable ligands include a halide ligand, a cyanide ligand, a cyan oxide ligand, a nitrosyl ligand, a thionitrosyl ligand, and the like. Although the example of the specific complex used for this invention below is shown, this invention is not limited to this.
[0093]
[ReCl₆]^3-, [ReBr₆]^3-, [ReCl_Five(NO)]^2-, [Re (NS) Br_Five]^2-, [Re (NO) (CN)_Five]^2-, [Re (O)₂(CN)_Four]^3-, [RuCl₆]^3-, [RuCl_Four(H₂O)₂]^-, [RuCl_Five(H₂O)]^2-, [RuCl_Five(NO)]^2-, [RuBr_Five(NS)]^2-, [Ru (CO)_ThreeCl_Three]^2-, [Ru (CO) Cl_Five]^2-, [Ru (CO) Br_Five]^2-, [OsCl₆]^3-, [OsCl_Five(NO)]^2-, [Os (NO) (CN)_Five]^2-, [Os (NS) Br_Five]^2-, [Os (O)₂(CN)_Four]^Four-
[0094]
The amount of these compounds added is 1 x 10 per mole of silver halide.^-9Mol ~ 1 × 10^-FiveThe molar range is preferred, particularly preferably 1 × 10^-8Mol ~ 1 × 10^-6Is a mole.
[0095]
The addition of these compounds can be appropriately carried out at the time of production of the silver halide emulsion grains and at each stage before coating the emulsion, but it is particularly preferred that they are added during the formation of the emulsion and incorporated into the silver halide grains. .
[0096]
In order to add these compounds during silver halide grain formation and incorporate them into silver halide grains, a metal complex powder or an aqueous solution dissolved together with NaCl and KCl is used as a water-soluble salt or water-soluble solution during grain formation. A method of adding silver halide in a silver halide solution, a method of adding silver salt and a halide solution as a third solution when they are simultaneously mixed, and a method of preparing silver halide grains by a method of three-liquid simultaneous mixing, or grain formation There is a method in which a required amount of an aqueous solution of a metal complex is put into a reaction vessel. In particular, a method of adding an aqueous solution dissolved with powder or NaCl or KCl to the water-soluble halide solution is preferable.
[0097]
In order to add to the particle surface, a necessary amount of an aqueous solution of a metal complex can be added to the reaction vessel immediately after the formation of the particle, during or after the physical ripening, or at the chemical ripening.
[0098]
Various compounds can be used as the iridium compound used in the present invention, and examples thereof include hexachloroiridium, hexaammineiridium, trioxalatoiridium, hexacyanoiridium, and pentachloronitrosyliridium. These iridium compounds are used by dissolving in water or an appropriate solvent, and are generally used in order to stabilize a solution of the iridium compound, that is, an aqueous hydrogen halide solution (for example, hydrochloric acid, odorous acid, hydrofluoric acid). Or a method of adding an alkali halide (for example, KCl, NaCl, KBr, NaBr, etc.). Instead of using water-soluble iridium, it is also possible to add another silver halide grain previously doped with iridium and dissolve it at the time of silver halide preparation. The amount of these iridium compounds added is 1 × 10 5 per mole of silver halide.^-8Mol ~ 1 × 10^-3The molar range is preferred, 1 × 10^-7Mol ~ 5x10^-FourA molar range is more preferred.
[0099]
Furthermore, the silver halide grains used in the present invention may contain metal atoms such as cobalt, iron, nickel, chromium, palladium, platinum, gold, thallium, copper and lead. For cobalt, iron, chromium and ruthenium compounds, hexacyano metal complexes can be preferably used. Specific examples include, but are not limited to, ferricyanate ion, ferrocyanate ion, hexacyanocobaltate ion, hexacyanochromate ion, hexacyanoruthenate ion, and the like. The metal complex in the silver halide may be contained uniformly, may be contained in the core part at a high concentration, or may be contained in the shell part at a high concentration, and there is no particular limitation.
[0100]
The above metals are 1 x 10 per mole of silver halide^-9~ 1 × 10^-FourMole is preferred. In order to contain the above metal, it can be added in the form of a metal salt in the form of a single salt, a double salt or a complex salt at the time of particle preparation.
[0101]
The photosensitive silver halide grains can be desalted by washing with water by a method known in the art such as a noodle method or a flocculation method, but in the present invention, it may or may not be desalted.
[0102]
The silver halide emulsion of the present invention is preferably subjected to chemical sensitization. As the chemical sensitization method, known methods such as sulfur sensitization method, selenium sensitization method, tellurium sensitization method and noble metal sensitization method can be used.
A plurality of chemical sensitization methods can be used in combination, for example, sulfur sensitization method and gold sensitization method, sulfur sensitization method and selenium sensitization method or tellurium sensitization method, gold sensitization method and selenium sensitization method. Or tellurium sensitizing method, sulfur sensitizing method and selenium sensitizing method or tellurium sensitizing method and gold sensitizing method, sulfur sensitizing method and selenium sensitizing method and tellurium sensitizing method, sulfur sensitizing method and selenium sensitizing method. And tellurium sensitization method and gold sensitization method.
[0103]
The sulfur sensitization preferably used in the present invention is usually carried out by adding a sulfur sensitizer and stirring the emulsion at a high temperature of 40 ° C. or higher for a predetermined time. Known compounds can be used as the sulfur sensitizer, for example, various sulfur compounds such as thiosulfate, thioureas, thiazoles, rhodanines, etc. in addition to sulfur compounds contained in gelatin. be able to. Preferred sulfur compounds are thiosulfate and thiourea compounds. The amount of sulfur sensitizer added varies under various conditions such as pH during chemical ripening, temperature, and the size of silver halide grains, but it is 1 x 10 per mole of silver halide.^-7~ 1 × 10^-2Mol, more preferably 1 × 10^-Five~ 1 × 10^-3Is a mole.
[0104]
As the gold sensitizer used for gold sensitization to the silver halide emulsion of the present invention, the oxidation number of gold may be +1 or +3, and gold compounds usually used as gold sensitizers are used. Can be used. Typical examples include chloroauric acid, potassium chloroaurate, auric trichloride, potassium auric thiocyanate, potassium iodoaurate, tetracyanoauric acid, ammonium aurothiocyanate, pyridyltrichlorogold, and the like.
[0105]
The amount of gold sensitizer added varies depending on various conditions, but as a guideline it is 1 x 10 per mole of silver halide.^-7More than mole 1 × 10^-3Mol or less, more preferably 1 × 10^-6More than mole 5 × 10^-FourIt is below the mole.
[0106]
A known selenium compound can be used as the selenium sensitizer used in the present invention. That is, it is usually carried out by adding unstable and / or non-unstable selenium compounds and stirring the emulsion at a high temperature of 40 ° C. or higher for a predetermined time. As the unstable selenium compound, compounds described in JP-B-44-15748, JP-A-43-13489, JP-A-4-25832, JP-A-4-109240 and JP-A-4-324855 can be used. In particular, it is preferable to use compounds represented by general formulas (VIII) and (IX) in JP-A-4-324855.
[0107]
The tellurium sensitizer used in the present invention is a compound that forms silver telluride presumed to be a sensitization nucleus on the surface or inside of a silver halide grain. The rate of silver telluride formation in the silver halide emulsion can be tested by the method described in JP-A-5-313284. Examples of tellurium sensitizers include diacyl tellurides, bis (oxycarbonyl) tellurides, bis (carbamoyl) tellurides, diacyl tellurides, bis (oxycarbonyl) ditellurides, bis (carbamoyl) ditellurides, P = Te Compounds having a bond, tellurocarboxylates, Te-organyl tellurocarboxylates, di (poly) tellurides, tellurides, tellurols, telluroacetals, tellurosulfonates, compounds having a P-Te bond, Te heterocycles, tellurocarbonyl compounds, inorganic tellurium compounds, colloidal tellurium and the like can be used. Specifically, U.S. Patent Nos. 1,623,499, 3,320,069, 3,772,031, British Patent Nos. 4-204640, Japanese Patent Application Nos. 3-53693, 3-131598, 4-129787, Journal of Chemical Society, Chemical Communication (J. Chem. Soc. Chem. Commun.), 635 (1980), ibid, 1102 (1979), ibid, 645 (1979), Journal of Chemical Society Perkin Transaction 1 (J.Chem.Soc.Perkin.Trans.1), 2191 (1980), S As described in The Chemistry of Organic Serenium and Tellunium Compounds, Vol 1 (1986), Vol 2 (1987), edited by S. Patai. Compounds can be used. In particular, compounds represented by the general formulas (II), (III) and (IV) in JP-A-5-313284 are preferred.
[0108]
The amount of selenium and tellurium sensitizers used in the present invention varies depending on the silver halide grains used, chemical ripening conditions, etc., but is generally 1 × 10 6 per mole of silver halide.^-8~ 1 × 10^-2Moles, preferably 1 x 10^-7~ 1 × 10^-3Use about moles. The conditions for chemical sensitization in the present invention are not particularly limited, but the pH is 5 to 8, the pAg is 6 to 11, preferably 7 to 10, and the temperature is 40 to 95 ° C., preferably 45 to 85 ° C.
[0109]
In the silver halide emulsion used in the present invention, a cadmium salt, a sulfite salt, a lead salt, a thallium salt or the like may coexist in the process of silver halide grain formation or physical ripening.
[0110]
In the present invention, reduction sensitization can be used. As specific compounds of the reduction sensitization method, for example, stannous chloride, aminoiminomethanesulfinic acid, hydrazine derivatives, borane compounds, silane compounds, polyamine compounds, etc. can be used in addition to ascorbic acid and thiourea dioxide. . Further, reduction sensitization can be performed by ripening the emulsion while maintaining the pH at 7 or higher or pAg at 8.3 or lower. Further, reduction sensitization can be performed by introducing a single addition portion of silver ions during grain formation.
[0111]
A thiosulfonic acid compound may be added to the silver halide emulsion of the present invention by the method shown in European Patent Publication No. 293,917.
[0112]
The light-sensitive silver halide emulsion in the light-sensitive material used in the present invention may be one kind or two or more kinds (for example, those having different average grain sizes, different halogen compositions, different crystal habits, chemical increase). Those with different feeling conditions) may be used in combination. The gradation can be adjusted by using a plurality of types of photosensitive silver halides having different sensitivities. As technologies related to these, JP-A-57-119341, 53-106125, 47-3929, 48-55730, 46-5187, 50-73627, 57-150841, etc. Can be mentioned. As the sensitivity difference, it is preferable that each emulsion has a difference of 0.2 logE or more.
[0113]
The addition amount of photosensitive silver halide is 1m of sensitive material.²0.03 to 0.6 g / m²Preferably, 0.05 to 0.4 g / m²More preferably, 0.1 to 0.4 g / m²Most preferably, the photosensitive silver halide is from 0.01 mol to 0.5 mol, more preferably from 0.02 mol to 0.3 mol, and particularly preferably from 0.03 mol to 0.25 mol with respect to 1 mol of the organic silver salt. .
[0114]
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.
[0115]
The preferred addition time of the silver halide of the present invention to the image-forming layer coating solution is from 180 minutes before coating to immediately before, preferably from 60 minutes to 10 seconds before coating. There is no particular limitation as long as the effects of the invention are sufficiently exhibited. Specific mixing methods include mixing in a tank in which the average residence time calculated from the addition flow rate and the amount of liquid delivered to the coater is the desired time, and by N. Harnby, MFEdwards, AWNienow, Takahashi There is a method of using a static mixer or the like described in Chapter 8 of the translation of Koji “Liquid Mixing Technology” (published by Nikkan Kogyo Shimbun, 1989).
[0116]
In the present invention, when the organic silver salt-containing layer is formed using a coating solution in which 30 wt% or more of the solvent is water and dried, the binder of the organic silver salt-containing layer is further an aqueous solvent (water Solvent is soluble or dispersible in the solvent, and is improved particularly when it is made of a latex of a polymer having an equilibrium moisture content of 2 wt% or less at 25 ° C. and 60% RH. The most preferable form is one prepared so that the ionic conductivity is 2.5 mS / cm or less, and as such a preparation method, there is a method of purifying using a separation functional membrane after polymer synthesis.
[0117]
The aqueous solvent in which the polymer is soluble or dispersible here is a mixture of water or water with 70 wt% 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.
[0118]
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.
[0119]
“Equilibrium moisture content at 25 ° C. and 60% RH” means the weight W1 of the polymer in the humidity-controlled equilibrium under the atmosphere of 25 ° C. and 60% RH and the weight W0 of the polymer in the absolutely dry state at 25 ° C. It can be expressed as
Equilibrium moisture content at 25 ℃ 60% RH = {(W1-W0) / W0} x 100 (wt%)
[0120]
For the definition and measurement method of the moisture content, for example, Polymer Engineering Course 14, Polymer Material Testing Method (Edited by Polymer Society, Jinshokan) can be referred to.
[0121]
The equilibrium water content of the binder polymer of the present invention at 25 ° C. and 60% RH is preferably 2 wt% or less, more preferably 0.01 wt% or more and 1.5 wt% or less, and further preferably 0.02 wt% or more and 1 wt% or less. .
[0122]
In the present invention, a polymer dispersible in an aqueous solvent is particularly preferred.
[0123]
Examples of the dispersed state include latex in which fine particles of solid polymer are dispersed and polymer molecules dispersed in a molecular state or forming micelles, and all are preferable.
[0124]
In a preferred embodiment of the present invention, a hydrophobic polymer such as an acrylic resin, a polyester resin, a rubber-based resin (for example, an SBR resin), a polyurethane resin, a vinyl chloride resin, a vinyl acetate resin, a vinylidene chloride resin, or a polyolefin resin is preferably used. it can. The polymer may be a linear polymer, a branched polymer, or a crosslinked polymer. The polymer may be a so-called homopolymer obtained by polymerizing a single monomer, or a copolymer obtained by polymerizing two or more types of monomers. In the case of a copolymer, it may be a random copolymer or a block copolymer. The molecular weight of the polymer is 5,000 to 100,000, preferably 10,000 to 200,000 in terms of number average molecular weight. When the molecular weight is too small, the mechanical strength of the emulsion layer is insufficient, and when the molecular weight is too large, the film formability is poor, which is not preferable.
[0125]
The “aqueous solvent” refers to a dispersion medium in which 30% by weight or more of the composition is water. The dispersion state may be any one such as an emulsified dispersion, a micelle-dispersed, or a polymer having a hydrophilic portion in the molecule dispersed in the molecular state, and among these, latex is particularly preferable. .
[0126]
Specific examples of preferable polymer latex include the following. Below, it represents using a raw material monomer, the numerical value in a parenthesis is wt%, and molecular weight is a number average molecular weight.
[0127]
Latex of P-1; -MMA (70) -EA (27) -MAA (3)-(molecular weight 37000)
P-2; -MMA (70) -2EHA (20) -St (5) -AA (5)-latex (molecular weight 40000)
Latex of P-3; -St (50) -Bu (47) -MAA (3)-(molecular weight 45000)
Latex of P-4; -St (68) -Bu (29) -AA (3)-(molecular weight 60000)
P-5; -St (70) -Bu (27) -IA (3)-latex (molecular weight 120,000)
Latex of P-6; -St (75) -Bu (24) -AA (1)-(molecular weight 108000)
Latex of P-7; -St (60) -Bu (35) -DVB (3) -MAA (2)-(molecular weight 150000)
P-8; -St (70) -Bu (25) -DVB (2) -AA (3)-latex (molecular weight 280000)
P-9; -VC (50) -MMA (20) -EA (20) -AN (5) -AA (5)-latex (molecular weight 80000)
Latex of P-10; -VDC (85) -MMA (5) -EA (5) -MAA (5)-(molecular weight 67000)
Latex of P-11; -Et (90) -MAA (10)-(molecular weight 12000)
P-12; -St (70) -2EHA (27) -AA (3) latex (molecular weight 130000)
P-13; -MMA (63) -EA (35)-AA (2) latex (molecular weight 33000)
[0128]
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.
[0129]
The polymer latex described above is also commercially available, and the following polymers can be used. Examples of acrylic resin include polyester resins such as Sebian A-4635, 46583, 4601 (manufactured by Daicel Chemical Industries, Ltd.), Nipol Lx811, 814, 821, 820, 857 (manufactured by Nippon Zeon Co., Ltd.). Examples of polyurethane resins include FINETEX ES650, 611, 675, 850 (Dainippon Ink Chemical Co., Ltd.), WD-size, WMS (Eastman Chemical), HYDRAN AP10, 20, Examples of rubber resins such as 30, 40 (above Dainippon Ink Chemical Co., Ltd.) include LACSTAR 7310K, 3307B, 4700H, 7132C (above Dainippon Ink Chemical Co., Ltd.), Nipol Lx416, 410, 438C , 2507 (manufactured by Nippon Zeon Co., Ltd.), etc., examples of vinyl chloride resins are G351, G576 (manufactured by Nippon Zeon Co., Ltd.), etc. Examples of olefin resins such as Chemipearl S120, SA100 (above Mitsui Petrochemical Co., Ltd.) ), And the like.
[0130]
These polymer latexes may be used alone or in combination of two or more as required.
[0131]
The polymer latex used in the present invention is particularly preferably a styrene-butadiene copolymer latex. The weight ratio of the styrene monomer unit to the butadiene monomer unit in the styrene-butadiene copolymer is preferably 40:60 to 95: 5. The proportion of the styrene monomer unit and the butadiene monomer unit in the copolymer is preferably 60 to 99 wt%. The preferred molecular weight range is the same as described above.
[0132]
Examples of the latex of styrene-butadiene copolymer that is preferably used in the present invention include the above-mentioned P-3 to P-8, commercially available products LACSTAR-3307B, 7132C, Nipol Lx416, and the like.
[0133]
If necessary, a hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose, or hydroxypropylcellulose may be added to the organic silver salt-containing layer of the light-sensitive material of the present invention. The addition amount of these hydrophilic polymers is preferably 30 wt% or less, more preferably 20 wt% or less of the total binder of the organic silver salt-containing layer.
[0134]
The organic silver salt-containing layer (that is, the image forming layer) of the present invention is formed using a polymer latex, and the amount of the binder in the organic silver salt-containing layer is the weight of the total binder / organic silver salt. The ratio is preferably in the range of 1/10 to 10/1, more preferably 1/5 to 4/1.
[0135]
Further, such an organic silver salt-containing layer is usually a photosensitive layer (emulsion layer) containing a photosensitive silver halide which is a photosensitive silver salt. The weight ratio of silver is preferably 400-5, more preferably 200-10.
[0136]
The total binder amount of the image forming layer of the present invention is 0.2 to 30 g / m.², More preferably 1-15 g / m²The range of is preferable. The image forming layer of the present invention may contain a crosslinking agent for crosslinking, a surfactant for improving coating properties, and the like.
[0137]
In the present invention, the solvent of the coating solution for the organic silver salt-containing layer of the photosensitive material (here, for simplicity, the solvent and the dispersion medium are collectively referred to as a solvent) is an aqueous solvent containing 30 wt% 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 wt% or more, more preferably 70 wt% or more. Examples of preferred solvent compositions include water, water / methyl alcohol = 90/10, water / methyl alcohol = 70/30, water / methyl alcohol / dimethylformamide = 80/15/5, water / methyl alcohol / There are ethyl cellosolve = 85/10/5, water / methyl alcohol / isopropyl alcohol = 85/10/5, etc. (value is wt%).
[0138]
As the sensitizing dye in the present invention, any sensitizing dye may be used as long as it can spectrally sensitize the silver halide grains in a desired wavelength region when adsorbed on the silver halide grains. As the sensitizing dye, a cyanine dye, a merocyanine dye, a complex cyanine dye, a complex merocyanine dye, a hoholor cyanine dye, a styryl dye, a hemicyanine dye, an oxonol dye, a hemioxonol dye, or the like can be used. Useful sensitizing dyes used in the present invention are described in, for example, the references described or cited in RESEARCH DISCLOSURE Item 17643IV-A (December 1978 p.23), Item1831X (August 1979 p.437) Has been. In particular, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of the light sources of various laser imagers, scanners, image setters and plate-making cameras can be advantageously selected.
[0139]
Sensitizing dyes include compounds represented by paragraphs 0056 to 0066 of JP-A-10-62899, general formula (II) of JP-A-10-186572, page 19, lines 38 to 38 of EP 080364A1. 20 pages, line 35. Examples of the sensitizing dye include dyes having a carboxylic acid group (for example, dyes described in JP-A Nos. 3-163440 and 6-301141 and US Pat. No. 5,441,899), merocyanine dyes, polynuclear merocyanine dyes and polynuclear cyanine dyes ( JP-A-47-6329, 49-105524, 51-127719, 52-80829, 54-61517, 59-214846, 60-6750, 63-159841, JP-A-6-35109, JP-A-6-59381, JP-A-7-65537, JP-A-7-65537, JP-A-5-550111, British Patent 1,467,638, US Pat. No. 5,281,515), and Dyes that form J-band (the dyes described in Example 5 of US Pat. Nos. 5,510,236 and 3,871,887, JP-A-2-96131 and JP-A-59-48753) can be preferably used in the present invention.
[0140]
These sensitizing dyes may be used alone or in combination of two or more. A combination of sensitizing dyes is often used for the purpose of supersensitization. Along with the sensitizing dye, the emulsion itself may contain a dye having no spectral sensitizing action or a substance that does not substantially absorb visible light and exhibits supersensitization. Useful sensitizing dyes, combinations of dyes exhibiting supersensitization, and substances exhibiting supersensitization are listed in Research Disclosure 176, 17643 (issued in December 1978), page 23, Section J, or Japanese Patent Publication No. 49-25500. No. 43-4933, JP-A-59-19032, 59-192242 and the like.
[0141]
To add sensitizing dyes to the silver halide emulsion, they may be dispersed directly in the emulsion, or water, methanol, ethanol, propanol, acetone, methyl cellosolve, 2,2,3,3- Solvents such as tetrafluoropropanol, 2,2,2-trifluoroethanol, 3-methoxy-1-propanol, 3-methoxy-1-butanol, 1-methoxy-2-propanol, N, N-dimethylformamide alone or It may be dissolved in a mixed solvent and added to the emulsion.
[0142]
Further, as disclosed in US Pat. No. 3,469,987, etc., a dye is dissolved in a volatile organic solvent, this solution is dispersed in water or a hydrophilic colloid, and this dispersion is added to the emulsion. Method, as disclosed in Japanese Patent Publication Nos. 44-23389, 44-27555, 57-22091, etc., a dye is dissolved in an acid, and this solution is added to an emulsion, or an acid or a base is added. A method of adding it into an emulsion as an aqueous solution, as disclosed in US Pat. Nos. 3,822,135, 4,006,025, etc., and adding an aqueous solution or colloidal dispersion in the emulsion as a surfactant coexists As disclosed in JP-A-53-102733 and JP-A-58-105141, a method in which a dye is directly dispersed in a hydrophilic colloid, and the dispersion is added to an emulsion. As disclosed in US Pat. No. 74624, colors can be obtained using red-shifting compounds. Was dissolved, the solution can also be used a method of adding to the emulsion. In addition, ultrasonic waves can be used for dissolution.
[0143]
The time when the sensitizing dye used in the present invention is added to the silver halide emulsion of the present invention may be during any step of emulsion preparation that has been found useful. For example, as disclosed in the specifications of U.S. Pat.Nos. 2,735,766, 3,628,960, 4,183,756, 4,225,666, JP-A-58-184142, 60-196749, etc., a silver halide grain forming step Or / and the time before desalting, during the desalting step and / or after the desalting and before the start of chemical ripening, as disclosed in the specification of JP-A-58-113920, etc. It may be added in the process at any time as long as it is before or during the process, after chemical ripening and before the emulsion is coated. Further, as disclosed in the specifications of US Pat. No. 4,225,666 and Japanese Patent Application Laid-Open No. 58-7629, the same compound can be used alone or in combination with a compound of a different structure, for example, during the particle formation process. It may be added separately during the ripening process or after chemical ripening, divided before or during chemical ripening, or after completion of the process, etc. You may change and add. Preferably, it is the time from the desalting step to application, more preferably the time from desalting to before the start of chemical ripening.
[0144]
The amount of the sensitizing dye used in the present invention may be a desired amount according to the performance such as sensitivity and fog, but it is 10 per mol of silver halide in the photosensitive layer.^-6~ 1 mole is preferred, 10^-Four~Ten^-1Mole is more preferred.
[0145]
The silver halide emulsions and / or organic silver salts in the present invention are further protected against the formation of additional fog by antifoggants, stabilizers and stabilizer precursors, and against reduced sensitivity during inventory storage. Can be stabilized. Suitable antifoggants, stabilizers and stabilizer precursors that can be used alone or in combination are disclosed in paragraph No. 0070 of JP-A-10-62899, page 20, lines 57 to 57 of European Patent Publication 080364A1. Patents described on page 21, line 7 can be mentioned.
[0146]
Antifoggants preferably used in the present invention are organic halides, such as JP-A-50-119624, 50-120328, 51-121332, 54-58022, 56-70543, 56-99335, 59-90842, 61-129642, 62-129845, JP-A-6-208191, 7-5621, 7-2781, 8-15809, And compounds disclosed in US Pat. Nos. 10,339,934, US Pat. Nos. 5,340,712, 5,536,000 and 5,464,737. In particular, compounds represented by the general formula (II) of JP-A-10-339934 (specifically, tribromomethylnaphthylsulfone, tribromomethylphenylsulfone, tribromomethyl (4- (2,4,6-trimethylphenyl) Sulfonyl) phenyl) sulfone and the like are preferred.
[0147]
The antifoggant of the present invention may be added by any method such as a solution, powder or solid fine particle dispersion. The solid fine particle dispersion is performed by a known finer means (for example, ball mill, vibration ball mill, sand mill, colloid mill, jet mill, roller mill, etc.). In addition, when dispersing the solid fine particles, a dispersion aid such as an anionic surfactant (for example, sodium triisopropyl naphthalenesulfonate (a mixture of three different isopropyl group substitution positions)) may be used.
[0148]
Although not necessary to practice the present invention, it may be advantageous to add mercury (II) salts to the emulsion layers as antifoggants. Preferred mercury (II) salts for this purpose are mercury acetate and mercury bromide. The amount of mercury used in the present invention is preferably 1 × 10 5 per mole of silver applied.^-9Mol ~ 1 × 10^-3Mole, more preferably 1 × 10^-9Mol ~ 1 × 10^-FourThe range of moles.
[0149]
The photothermographic material in the invention may contain an azolium salt or a benzoic acid for the purpose of increasing sensitivity and preventing fogging. Examples of the azolium salt include compounds represented by general formula (XI) described in JP-A-59-193447, compounds described in JP-B-55-12581, and general formula (II) described in JP-A-60-153039. And the compounds represented. The benzoic acid compound may be any benzoic acid derivative, but examples of preferred structures include those described in U.S. Pat. Compounds. An azolium salt or benzoic acid may be added to any part of the photosensitive material, but the additive layer is preferably added to the layer having the photosensitive layer, and more preferably added to the organic silver salt-containing layer. . The azolium salt and benzoic acid may be added at any step in the coating solution preparation. When added to the organic silver salt-containing layer, any step from the preparation of the organic silver salt to the preparation of the coating solution may be used. It is preferable that the salt is prepared and immediately before coating. The azolium salt or benzoic acid may be added by any method such as powder, solution, or fine particle dispersion. Moreover, you may add as a solution mixed with other additives, such as a sensitizing dye, a reducing agent, and a color toning agent. In the present invention, the azolium salt and benzoic acid may be added in any amount, but 1 × 10 10 per mole of silver.^-6Preferred is 1 mol or more and 2 mol or less.^-3More preferably, it is more than mol and less than 0.5 mol.
[0150]
In the present invention, a mercapto compound, a disulfide compound, and a thione compound can 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. .
[0151]
Examples of such mercapto compounds, disulfide compounds, and thione compounds include paragraph numbers 0067 to 0069 of JP-A-10-62899, compounds represented by general formula (I) of JP-A-10-186572, and paragraph numbers as specific examples thereof. 0033 to 0052, and on page 20, lines 36 to 56 of European Patent Publication No. 0803684A1. Among these, mercapto-substituted heteroaromatic compounds are preferable, such as 2-mercaptobenzimidazole, 2-mercapto-5-methylbenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-methylbenzimidazole, 6- Ethoxy-2-mercaptobenzothiazole, 2,2'-dithiobis- (benzothiazole, 3-mercapto-1,2,4-triazole, 4,5-diphenyl-2-imidazolethiol, 2-mercaptoimidazole, 1-ethyl 2-mercaptobenzimidazole, 2-mercaptoquinoline, 8-mercaptopurine, 2-mercapto-4 (3H) -quinazolinone, 7-trifluoromethyl-4-quinolinethiol, 2,3,5,6-tetrachloro- 4-pyridinethiol, 4-amino-6-hydroxy-2-mercaptopyrimidine monohydrate, 2-amino-5-mercapto-1,3,4-thiadiazole, 3-amino-5-mercapto-1,2,4-triazole, 4-hydroxy-2-mercaptopyrimidine, 2-mercaptopyrimidine, 4,6-diamino-2-mercaptopyrimidine, 2-mercapto-4-methylpyrimidine hydro Chloride, 3-mercapto-5-phenyl-1,2,4-triazole, 2-mercapto-4-phenyloxazole, 3-mercapto-4-phenyl-5-heptyl-1,2-4-triazole, etc. It is done.
[0152]
The addition amount of these mercapto compounds is preferably in the range of 0.001 to 1.0 mol per mol of silver in the emulsion layer, and more preferably 0.01 to 0.3 mol per mol of silver.
[0153]
When an additive known as a “toning agent” for improving an image is included, the optical density may be increased, and in the present invention, the addition of a toning agent is preferable. The toning agent may also be advantageous in forming a black silver image. The color toning agent is preferably contained in the surface having the image forming layer in an amount of 0.1 to 50 mol%, more preferably 0.5 to 20 mol% per 1 mol of silver. The toning agent may be a so-called precursor that is derivatized so as to have an effective function only during development.
[0154]
Such toning agents include phthalazinone, phthalazinone derivatives, or the toning agents described in paragraphs 0054 to 0055 of JP-A No. 10-62899, page 21, lines 23 to 48 of European Patent Publication No. 0803684A1. Metal salts or derivatives such as 4- (1-naphthyl) phthalazinone, 6-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, and tetrachlorophthalic anhydride); phthalazines (phthalazine, phthalazine derivatives or metal salts, or 4- (1-naphthyl) phthalazine, 6- Derivatives such as isopropyl phthalazine, 6-t-butyl phthalazine, 6-chlorophthalazine, 5,7-dimethoxyphthalazine and 2,3-dihydrophthalazine) Phthalazine and phthalic acid derivatives (e.g., phthalic acid, 4-nitrophthalic such acid and tetrachlorophthalic anhydride) are preferred combination of, in particular combinations of phthalazine and phthalic acid derivatives.
[0155]
The toning agent of the present invention may be added by any method such as a solution, a powder, or a solid fine particle dispersion. The solid fine particle dispersion is performed by a known finer means (for example, ball mill, vibration ball mill, sand mill, colloid mill, jet mill, roller mill, etc.). A dispersion aid may be used when dispersing the solid fine particles.
[0156]
In the photosensitive layer of the present invention, a polyhydric alcohol (for example, glycerin and diol of the type described in US Pat. No. 2,960,404), a plasticizer and a lubricant described in US Pat. Nos. 2,588,765 and 3,121,060 are used. Fatty acids or esters, silicone resins described in British Patent No. 955,061 and the like can be used.
[0157]
In the present invention, an ultrahigh contrast agent can be used to form an ultrahigh contrast image. For example, U.S. Patent Nos. 5,464,738, 5,496,695, 6,512,411, 5,536,622, Japanese Patent Application Nos. 7-228627, 8-215822, 8-130842, 8-148113, 8-156378 Hydrazine derivatives described in JP-A-8-148111 and 8-148116, compounds having a quaternary nitrogen atom described in Japanese Patent Application No. 8-83566, and acrylonitrile compounds described in US Pat. No. 5,545,515. Can be used. Specific examples of the compound include compounds 1 to 10 of the aforementioned US Pat. No. 5,464,738, H-1 to H-28 of 5,496,695, I-1 to I-86 of Japanese Patent Application No. 8-215822, 8- 130842 H-1 to H-62, 8-148113 1-1 to 1-21, 8-148111 1-50, 8-148116 1-40, 8-83566 P-1 to P-26, and T-1 to T-18, CN-1 to CN-13 of US Pat. No. 5,545,515, and the like.
[0158]
Further, in the present invention, in order to form a super high contrast image, a high contrast accelerator can be used in combination with the super high contrast agent. For example, amine compounds described in U.S. Pat.No. 5,545,505, specifically, AM-1 to AM-5, hydroxamic acids described in 5,545,507, specifically HA-1 to HA-11, and 5,545,507 Described acrylonitriles, specifically CN-1 to CN-13, hydrazine compounds described in US Pat. No. 5,558,983, specifically CA-1 to CA-6, and ones described in Japanese Patent Application No. 8-132836 Salt, specifically A-1 to A-42, B-1 to B-27, C-1 to C-14, and the like can be used.
[0159]
The synthesis method, the addition method, the addition amount, and the like of these super-high contrast agents and high-contrast accelerators can be performed as described in the respective cited patents.
[0160]
The preparation temperature of the image forming layer coating solution of the present invention is preferably from 30 ° C. to 65 ° C., more preferably from 35 ° C. to less than 60 ° C., and more preferably from 35 ° C. to 55 ° C. Further, it is preferable that the temperature of the image forming layer coating solution immediately after the addition of the polymer latex is maintained at 30 ° C. or more and 65 ° C. or less. Moreover, it is preferable that the reducing agent and the organic silver salt are mixed before adding the polymer latex.
[0161]
The organic silver salt-containing fluid or the thermal image forming layer coating solution in the present invention is preferably a so-called thixotropic fluid. Thixotropy refers to the property that the viscosity decreases as the shear rate increases. Although any apparatus 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 measured at 25 ° C. Here, the organic silver salt-containing fluid or the thermal image forming layer coating liquid in the present invention has a shear rate of 0.1 S.^-1The viscosity 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. Also, shear rate 1000S^-1Is preferably from 1 mPa · s to 200 mPa · s, more preferably from 5 mPa · s to 80 mPa · s.
[0162]
Various systems that exhibit thixotropic properties are known, and are described in “Lectures / Rheology” edited by Polymer Publishing Co., “Polymer Latex” (published by Polymer Publishing Co., Ltd.) co-authored by Muroi and Morino. In order for the fluid to exhibit thixotropy, it is necessary to contain a large amount of solid fine particles. In order to enhance the thixotropy, it is effective to contain a thickening linear polymer, increase the aspect ratio in the anisotropic shape of the contained solid fine particles, increase the alkali viscosity, and use a surfactant.
[0163]
The heat-developable photographic emulsion of the present invention is composed of one or more layers on a support. One layer composition must contain organic silver salts, silver halides, developers and binders, and optional additional materials such as toning agents, coating aids and other aids. The two-layer construction must include an organic silver salt and silver halide in the first emulsion layer (usually the layer adjacent to the support) and some other components in the second or both layers. Don't be. However, a two-layer configuration comprising a single emulsion layer containing all components and a protective topcoat is also conceivable. The construction of a multicolor photosensitive photothermographic material may include a combination of these two layers for each color and includes all components in a single layer as described in US Pat. No. 4,708,928. Also good. In the case of a multi-dye multicolor photosensitive photothermographic material, each emulsion layer generally has a functional or non-functional barrier layer between each photosensitive layer as described in U.S. Pat.No. 4,460,681. By using, they are kept distinguished from each other.
[0164]
Various dyes and pigments can be used for the photosensitive layer of the present invention from the viewpoints of color tone improvement, interference fringe generation prevention during laser exposure, and irradiation prevention. These are described in detail in WO98 / 36322. Preferred dyes and pigments used in the photosensitive layer of the present invention include anthraquinone dyes, azomethine dyes, indoaniline dyes, azo dyes, anthraquinone-based indanthrone pigments (such as CI Pigment Blue 60), and phthalocyanine pigments (such as CI Pigment Blue 15). Copper phthalocyanine, metal free phthalocyanine such as CI Pigment Blue 16), dyed lake pigment type triarylcarbonyl pigment, indigo, inorganic pigment (ultraviolet, cobalt blue, etc.). As a method for adding these dyes and pigments, any method such as a solution, an emulsion, a solid fine particle dispersion, or a state mordanted in a polymer mordant may be used. The amount of these compounds used is determined by the target absorption amount, but generally 1 m of photosensitive material.²It is preferably used in the range of 1 μg or more and 1 g or less.
[0165]
In the present invention, the antihalation layer can be provided on the side far from the light source with respect to the photosensitive layer. The antihalation layer preferably has a maximum absorption in the desired wavelength range of 0.3 or more and 2 or less, more preferably an absorption of an exposure wavelength of 0.5 or more and 2 or less, and an absorption in the visible region after processing of 0.001 or more. It is preferably less than 0.5, more preferably a layer having an optical density of 0.001 or more and less than 0.3.
[0166]
When an antihalation dye is used in the present invention, the dye has a desired absorption in the wavelength range, has a sufficiently small absorption in the visible region after the treatment, and can obtain any desired absorbance spectrum shape of the antihalation layer. It may be a compound. For example, the following is disclosed, but the present invention is not limited to this. As a single dye, JP-A-59-56458, JP-A-2-216140, JP-A-7-13295, JP-A-111432, U.S. Pat.No. 5,380,635, JP-A-2-68539, page 13, lower left column From line 1 to page 14, lower left column, line 9, line 3-24539, page 14, lower left column to page 16, lower right column, there are compounds. 52-139136, 53-132334, 56-501480, 57-16060, 57-68831, 57-101835, 59-182436, JP-A-7-36145, 7 -199409, JP-B-48-33692, JP-B-50-16648, JP-B-2-41734, US Patents 4,088,497, 4,283,487, 4,548,896, and 5,187,049.
[0167]
In the present invention, it is preferable to add a decoloring dye and a base precursor to the non-photosensitive layer of the photothermographic material so that the non-photosensitive layer functions as a filter layer or an antihalation layer. The photothermographic material generally has a non-photosensitive layer in addition to the photosensitive layer. The non-photosensitive layer includes (1) a protective layer provided on the photosensitive layer (on the side farther from the support), and (2) a plurality of photosensitive layers or between the photosensitive layer and the protective layer. (3) an undercoat layer provided between the photosensitive layer and the support, and (4) a back layer provided on the opposite side of the photosensitive layer. The filter layer is provided on the photosensitive material as the layer (1) or (2). The antihalation layer is provided on the photosensitive material as the layer (3) or (4).
[0168]
The decolorizing dye and the base precursor are preferably added to the same non-photosensitive layer. However, it may be added separately to two adjacent non-photosensitive layers. A barrier layer may be provided between the two non-photosensitive layers.
[0169]
As a method of adding the decoloring dye to the non-photosensitive layer, a method of adding a solution, an emulsion, a solid fine particle dispersion, or a polymer impregnated product to the coating solution for the non-photosensitive layer can be employed. Moreover, you may add dye to a non-photosensitive layer using a polymer mordant. These addition methods are the same as the method of adding a dye to a normal photothermographic material. The latex used for the polymer impregnation is described in U.S. Pat. No. 4,199,363, West German Patent Publication Nos. 25141274, 2541230, European Patent Publication No. 0291104, and Japanese Patent Publication No. 53-41091. An emulsification method in which a dye is added to a solution in which a polymer is dissolved is described in International Publication No. 88/00723.
[0170]
The amount of decoloring dye added is determined by the use of the dye. In general, the optical density (absorbance) measured at the target wavelength is used in an amount exceeding 0.1. The optical density is preferably 0.2 to 2. The amount of dye used to obtain such an optical density is generally 0.001 to 1 g / m.²Degree. Preferably, 0.005 to 0.8 g / m²And particularly preferably 0.01 to 0.2 g / m.²Degree.
[0171]
If the dye is decolored in this way, the optical density can be reduced to 0.1 or less. Two or more kinds of decoloring dyes may be used in combination in a heat decoloring type recording material or a photothermographic material. Similarly, two or more kinds of base precursors may be used in combination.
[0172]
The photothermographic material in the invention is a so-called single-sided photosensitive material having a photosensitive layer containing at least one silver halide emulsion on one side of a support and a back layer on the other side. preferable.
[0173]
In the present invention, the matte degree of the back layer is preferably a Beck smoothness of 1200 seconds or less and 10 seconds or more, preferably 700 seconds or less and 30 seconds or more, and more preferably 500 seconds or less and 50 seconds or more.
[0174]
In the present invention, the matting agent is preferably contained in the outermost surface layer of the photosensitive material, the layer functioning as the outermost surface layer, or a layer close to the outer surface, and is contained in a layer acting as a so-called protective layer. It is preferable.
[0175]
In the present invention, a suitable binder for the back layer is transparent or translucent and generally colorless, and is a natural polymer synthetic resin, polymer and copolymer, and other media for forming a film, such as gelatin, gum arabic, poly (vinyl alcohol), Hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, poly (vinyl pyrrolidone), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid), copoly (styrene- Maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (esters), poly (urethane ), Phenoxy resin, poly ( Fluoride), poly (epoxides), poly (carbonates), poly (vinyl acetate), cellulose esters, and polyamides. The binder may be coated from water or an organic solvent or emulsion.
[0176]
In the present invention, the back layer preferably has a maximum absorption in a desired wavelength range of 0.3 or more and 2 or less, more preferably 0.5 or more and 2 or less, and an absorption in the visible region after treatment of 0.001 or more. It is preferably less than 0.5, more preferably a layer having an optical density of 0.001 or more and less than 0.3. Examples of the antihalation dye used for the back layer are the same as those of the antihalation layer described above.
[0177]
In the photothermographic material of the present invention, a backside resistive heating layer as shown in U.S. Pat. Nos. 4,460,681 and 4,374,921 can also be used.
[0178]
A hardener may be used for each layer such as the photosensitive layer, protective layer, and back layer of the present invention. Examples of hardeners include “THE THEORY OF THE PHOTOGRAPHIC PROCESS FOURTH EDITION” written by THJames (Macmillan Publishing Co., Inc., published in 1977), pages 77 to 87. Preferred are polyvalent metal ions, polyisocyanates such as US Pat. No. 4,281,060, JP-A-6-208193, epoxy compounds such as US Pat. No. 4,791,042, and vinyl sulfone compounds such as JP-A 62-89048. Used.
[0179]
The hardener is added as a solution, and the addition time of this solution into the protective layer coating solution is from 180 minutes before to immediately before application, preferably from 60 minutes to 10 seconds before application. As long as the effects of the present invention are sufficiently exhibited, there is no particular limitation. Specific mixing methods include mixing in a tank in which the average residence time calculated from the addition flow rate and the amount of liquid delivered to the coater is the desired time, and by N. Harnby, MFEdwards, AWNienow, Takahashi There is a method of using a static mixer or the like described in Chapter 8 of the translation of Koji “Liquid Mixing Technology” (published by Nikkan Kogyo Shimbun, 1989).
[0180]
In the present invention, a surfactant may be used for the purpose of improving the coating property of each layer and charging. As an example of the surfactant, any nonionic, anionic, cationic, or fluorine-based one can be used as appropriate. Specifically, fluorine-based polymer surfactants described in JP-A-62-170950, US Pat. No. 5,380,644, etc., fluorine-based surfactants described in JP-A-60-244945, JP-A-63-188135, etc. Surfactants, polysiloxy acid surfactants described in U.S. Pat. No. 3,885,965, polyalkylene oxides and anionic surfactants described in JP-A-6-301140 and the like can be mentioned.
[0181]
Examples of the solvent used in the present invention include New Edition Solvent Pocket Book (Ohm, published in 1994), but the present invention is not limited thereto. The boiling point of the solvent used in the present invention is preferably 40 ° C. or higher and 180 ° C. or lower.
[0182]
Examples of the solvent of the present invention include hexane, cyclohexane, toluene, methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, ethyl acetate, 1,1,1-trichloroethane, tetrahydrofuran, triethylamine, thiophene, trifluoroethanol, perfluoropentane, xylene. , N-butanol, phenol, methyl isobutyl ketone, cyclohexanone, butyl acetate, diethyl carbonate, chlorobenzene, dibutyl ether, anisole, ethylene glycol diethyl ether, N, N-dimethylformamide, morpholine, propane sultone, perfluorotributylamine, water, etc. Is mentioned.
[0183]
The photographic emulsion for heat development in the present invention can be coated on various supports. Typical supports are polyester film, primed polyester film, poly (ethylene terephthalate) film, polyethylene naphthalate film, cellulose nitrate film, cellulose ester film, poly (vinyl acetal) film, polycarbonate film and related or resinous Including materials, as well as glass, paper, metal and the like. Coated with flexible substrates, in particular baryta and / or partially acetylated α-olefin polymers, in particular polymers of α-olefins having 2 to 10 carbon atoms such as polyethylene, polypropylene, ethylene-butene copolymers. A paper support is typically used. Such a support may be transparent or opaque, but is preferably transparent. The transparent support may be colored with a blue dye (for example, dye-1 described in Examples of JP-A-8-240877).
[0184]
The light-sensitive material in the present invention is an antistatic or conductive layer, for example, a soluble salt (for example, chloride, nitrate, etc.), a vapor-deposited metal layer, an ionic polymer as described in US Pat. Nos. 2,861,056 and 3,206,312 or A layer containing an insoluble inorganic salt as described in US Pat. No. 3,428,451 may be included.
[0185]
The photothermographic material is preferably a mono-sheet type (a type capable of forming an image on the photothermographic material without using another sheet such as an image receiving material).
[0186]
An antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, or a coating aid may be further added to the photothermographic material. Various additives are added to either the photosensitive layer or the non-photosensitive layer. With respect to these, the respective specifications such as WO98 / 36322, EP803764A1, JP-A-10-186567, and 10-18568 can be referred to.
[0187]
In the photosensitive layer in the present invention, a polyhydric alcohol (for example, glycerin and diol of the kind described in US Pat. No. 2,960,404), a plasticizer and a lubricant described in US Pat. Nos. 2,588,765 and 3,121,060 are used. Fatty acids or esters, silicone resins described in British Patent No. 955,061, and the like can be used.
[0188]
As a method for obtaining a color image using the photothermographic material in the invention, there is a method described in JP-A-7-13295, page 10, left column, line 43 to 11, left column, line 40. Examples of color dye image stabilizers include British Patent 1,326,889, U.S. Patent 3,432,300, 3,698,909, 3,574,627, 3,573,050, 3,764,337, and 4,042,394. Yes.
[0189]
The photothermographic material in the invention may be applied by any method. Specifically, various coating operations are used, including extrusion coating, slide coating, curtain coating, dip coating, knife coating, flow coating, or extrusion coating using a hopper of the type described in U.S. Pat. Stephen F. Kistler, Petert M. Schweizer “LIQUID FILM COATING” (CHAPMAN & HALL, 1997) pages 399 to 536, preferably used for extrusion coating or slide coating, particularly preferably used for slide coating It is done. An example of the shape of the slide coater used for slide coating is shown in Figure 11b.1 on page 427 of the same book. If desired, two or more layers can be simultaneously coated by the method described in pages 399 to 536 of the same document, the method described in US Pat. No. 2,761,791 and British Patent No. 837,095.
[0190]
Additional layers in the photothermographic material of the present invention, such as a dye-receiving layer for receiving a moving dye image, an opacifying layer when reflective printing is desired, a protective topcoat layer, and a primer known in the photothermographic art Layers can be included. It is preferable that the photothermographic material of the present invention can form an image with only one photosensitive material, and it is preferable that a functional layer necessary for image formation such as an image receiving layer does not become another photosensitive material.
[0191]
Techniques that can be used for the photothermographic material of the present invention include EP803764A1, EP883022A1, WO98 / 36322, JP-A-9-281637, 9-297367, 9-304869, and 9-311405. 9-329865, 10-10669, 10-62899, 10-69023, 10-186568, 10-90823, 10-171063, 10-186565, 10-186567, 10-186569, 10-186570, 10-186571, 10-186572, 10-197974, 10-197982, 10-197983, 10-18683 197985, 10-197986, 10-197987, 10-207001, 10-207004, 10-221807, 10-282601, 10-288823, 10-288824, 10-288824 10-307365, 10-312038, 10-339934, 11-7100, 11-15105, 11-24200, 11-24201, 11-30832 It is done.
[0192]
The photothermographic material of the present invention may be developed by any method, but is usually developed by raising the temperature of the photothermographic material exposed imagewise. The preferred heat development temperature is 80 to 250 ° C, more preferably 100 to 140 ° C. The heat development time is preferably 1 to 180 seconds, more preferably 10 to 90 seconds, and particularly preferably 10 to 40 seconds.
[0193]
A plate heater method is preferred as the heat development method. The heat development method using the plate heater method is preferably the method described in Japanese Patent Application No. 9-229684 and Japanese Patent Application No. 10-177610, in which the photothermographic material on which the latent image is formed is brought into contact with the heating means in the heat developing unit. A heat developing device that obtains a visible image by causing the heating means to be a plate heater, and a plurality of pressing rollers are arranged to face each other along one surface of the plate heater; The photothermographic apparatus performs thermal development by passing the photothermographic material between the plate heater and the plate heater. It is preferable to divide the plate heater into 2 to 6 stages and lower the temperature about 1 to 10 ° C. at the tip. Such a method is also described in JP-A-54-30032, which can exclude moisture and organic solvents contained in the photothermographic material out of the system, and can be rapidly developed in the photothermographic material. It is also possible to suppress changes in the shape of the support of the photothermographic material due to heating of the photothermographic material.
[0194]
The light-sensitive material of the present invention may be exposed by any method, but laser light is preferred as the exposure light source. As the laser light according to the present invention, a gas laser (Ar⁺, He-Ne), YAG laser, dye laser, 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.
[0195]
As the laser beam, a single mode laser can be used. However, the photothermographic material as in the present invention has a low haze at the time of exposure and tends to generate interference fringes. -113548 etc. are known to illuminate the photosensitive material obliquely with respect to the photosensitive material, and a method using a multimode laser disclosed in WO95 / 31754 etc. is known. Can be used.
[0196]
To expose the photothermographic material of the present invention, exposure is performed so that laser beams overlap as disclosed in SPIE vol. 169 Laser Printing, pages 116-128 (1979), JP-A-4-51043, WO95 / 31754, etc. However, it is preferable to prevent the scanning lines from being seen.
The laser output is preferably 1 mW or more, more preferably 10 mW or more, and even more preferably 40 mW or more. At that time, a plurality of lasers may be combined. Laser beam diameter is 1 / e of Gaussian beam²The spot size can be about 30 to 200 μm.
[0197]
The photothermographic material of the present invention forms a black and white image by a silver image, and is used as a photothermographic material for medical diagnosis, a photothermographic material for industrial photography, a photothermographic material for printing, and a photothermographic material for COM. It is preferably used. In these uses, based on the black-and-white image formed, a duplicate image is formed on a copy film MI-Dup manufactured by Fuji Photo Film Co., Ltd. for medical diagnosis, and Fuji Photo Film Co., Ltd. is used for printing. It goes without saying that it can be used as a mask for forming an image on the return film DO-175, PDO-100 or offset printing plate.
[0198]
【Example】
Hereinafter, the present invention will be specifically described by way of examples.
Example 1
(PET support creation)
Using terephthalic acid and ethylene glycol, PET having an intrinsic viscosity of IV = 0.66 (measured in phenol / tetrachloroethane = 6/4 (weight ratio) at 25 ° C.) was obtained according to a conventional method. This was pelletized, dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die and quenched, and an unstretched film having a thickness of 175 μm after heat setting was prepared.
[0199]
This was stretched 3.3 times longitudinally using rolls with different peripheral speeds and then stretched 4.5 times with a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively. Thereafter, the film was heat-fixed at 240 ° C. for 20 seconds and relaxed by 4% in the lateral direction at the same temperature. After slitting the chuck part of the tenter, knurling is performed on both ends, and 4kg / cm²And a roll having a thickness of 175 μm was obtained.
[0200]
(Surface corona treatment)
Using a solid state corona treatment machine 6KVA model manufactured by Pillar, both surfaces of the support were treated at room temperature at 20 m / min. From the current and voltage readings at this time, the support is 0.375 kV · A · min / m²It was found that the process was done. The treatment frequency at this time was 9.6 kHz, and the gap clearance between the electrode and the dielectric roll was 1.6 mm.
[0201]
(Creation of undercoat support)
(1) Preparation of undercoat layer coating solution
Formulation (1) (for the undercoat layer on the photosensitive layer side)
Takamatsu Oil & Fats Co., Ltd. Pes Resin A-515GB (30wt% solution) 234g
Polyethylene glycol monononyl phenyl ether
(Average number of ethylene oxide = 8.5) 10wt% solution 21.5g
MP11000 made by Soken Chemical Co., Ltd. (polymer fine particles, average particle size 0.4μm) 0.91g
Distilled water 744ml
[0202]
Formulation (2) (for back layer 1st layer)
Butadiene-styrene copolymer latex 131g
(Solid content 40wt%, butadiene / styrene weight ratio = 32/68)
2,4-dichloro-6-hydroxy-s-
Triazine sodium salt 8wt% aqueous solution 5.1g
10% 1wt% aqueous solution of sodium laurylbenzenesulfonate
Distilled water 854ml
[0203]
Formula (3) (Back side 2nd layer)
SnO₂/ SbO (9/1 weight ratio, average particle size 0.038μm, 17wt% dispersion) 62g
Latin (10% aqueous solution) 65.7g Shin
METRO'S TC-5 (2% aqueous solution) 6.3g made by Koshi Chemical Co., Ltd.
MP-1000 (Polymer fine particles) manufactured by Ken Chemical Co., Ltd. 0.01g
10 ml of 1 wt% aqueous solution of sodium decylbenzenesulfonate
LOXEL (ICI) 1ml steam
Retained water 856ml
[0204]
(Preparation of undercoat support)
After applying the above corona discharge treatment to both sides of the 175 μm thick biaxially stretched polyethylene terephthalate support, undercoating liquid formulation (1) is applied to one side (photosensitive layer surface) with a wire bar at a wet coating amount of 6.6 ml. / m²(Per side) and dry at 180 ° C. for 5 minutes, then apply the undercoat coating solution formulation (2) on the back (back side) with a wire bar at a wet coating amount of 5.7 ml / m²And then dried at 180 ° C. for 5 minutes, and on the back side (back side), the undercoat coating liquid formulation (3) is applied with a wire bar to a wet coating amount of 5.7 ml / m.²And then dried at 180 ° C. for 6 minutes to prepare an undercoat support.
[0205]
(Preparation of back surface coating solution)
(Preparation of solid fine particle dispersion (a) of base precursor)
64 g of the base precursor compound 11, 28 g of the diphenylsulfone compound 12 and 10 g of the surfactant Demol N made by Kao Corporation were mixed with 220 ml of distilled water, and the mixture was mixed with a sand mill (1/4 Gallon Sand Grinder Mill, Imex Co., Ltd.) To obtain a solid fine particle dispersion (a) of a base precursor compound having an average particle size of 0.2 μm.
[0206]
(Preparation of dye solid fine particle dispersion)
9.6 g of cyanine dye compound 13 and 5.8 g of sodium P-dodecylbenzenesulfonate are mixed with 305 ml of distilled water, and the mixture is bead-dispersed using a sand mill (1/4 Gallon sand grinder mill, manufactured by IMEX Co., Ltd.). Thus, a dye solid fine particle dispersion having an average particle size of 0.2 μm was obtained.
[0207]
(Preparation of antihalation layer coating solution)
Gelatin 17 g, polyacrylamide 9.6 g, solid fine particle dispersion (a) 70 g of the above basic precursor, 56 g of the above dye solid fine particle dispersion 1.5 g of polymethyl methacrylate fine particles (average particle size 6.5 μm), 2.2 g of sodium polyethylene sulfonate, Blue dye compound 14 0.2g, H₂844 ml of O was mixed to prepare an antihalation layer coating solution.
[0208]
(Preparation of back surface protective layer coating solution)
The container was kept at 40 ° C., 50 g of gelatin, 0.2 g of sodium polystyrenesulfonate, 2.4 g of N, N-ethylenebis (vinylsulfonacetamide), 1 g of sodium t-octylphenoxyethoxyethanesulfonate, 30 mg of compound 4, C₈F₁₇SO_ThreeK 32mg, C₈F₁₇SO₂N (C_ThreeH₇) (CH₂CH₂O)_Four(CH₂)_Four-SO_ThreeNa 64mg, acrylic acid / ethyl acrylate copolymer (copolymerization weight ratio 5/95) 8.8g, H₂950 ml of O was mixed to prepare a coating solution for the back surface protective layer.
[0209]
<< Preparation of silver halide grains 1 >>
Add 18.0% potassium bromide solution (8.0cc) to distilled water (1421cc), then add 1cc nitric acid (8.2cc) and phthalated gelatin (20g). Keeping solution A prepared by adding distilled water to 37.04 g of silver nitrate and diluting to 159 cc, and preparing solution B by diluting 32.6 g of potassium bromide to 200 cc with distilled water, while maintaining pAg at 8.1 by the control double jet method The total amount of solution A was added at a constant flow rate over 1 minute. Solution B was added by the controlled double jet method. Thereafter, 30 cc of a 3.5 wt% aqueous hydrogen peroxide solution was added, and 36 cc of a 3 wt% aqueous solution of Compound 1 was further added. After that, again solution A2 diluted with distilled water to 317.5 cc, and solution B, finally 1 × 10 5 per silver mole^-FourDissolve compound 2 to a molar ratio and use solution B2 diluted with distilled water to 400 cc, twice the amount of solution B, and maintain a constant pAg of 8.1 by the controlled double jet method. Solution A2 was added in total over 10 minutes at the flow rate. Solution B2 was added by the controlled double jet method. After that, 50cc of 0.5wt% methanol solution of Compound 3 was added, and after increasing the pAg to 7.5 with silver nitrate, the pH was adjusted to 3.8 with 1N sulfuric acid, stirring was stopped, and precipitation / desalting / water washing steps were performed. Then, 3.5 g of deionized gelatin was added, and 1N sodium hydroxide was added to adjust the pH to 6.0 and pAg 8.2 to prepare a silver halide dispersion.
[0210]
Grains in the resulting silver halide emulsion were pure silver bromide grains having an average sphere equivalent diameter of 0.053 μm and a sphere equivalent diameter variation coefficient of 18%. The particle size and the like were determined from an average of 1000 particles using an electron microscope. The {100} face ratio of the grains was determined to be 85% using the Kubelka-Munk method.
[0211]
While maintaining the above emulsion at 38 ° C. with stirring, 0.035 g of compound 4 (added in 3.5 wt% methanol solution) was added, and after 40 minutes, a solid dispersion of spectral sensitizing dye A (gelatin aqueous solution) per mole of silver 5 × 10^-3Mole was added, and after 1 minute, the temperature was raised to 47 ° C., and after 20 minutes, compound 5 was 3 × 10 3 mol per mole of silver^-Five2 minutes later, tellurium sensitizer B was added 5 x 10 per mole of silver.^-FiveMole was added and aged for 90 minutes. At the end of ripening, 5 cc of a 0.5 wt% methanol solution of Compound 6 was added and the temperature was lowered to 31 ° C., 5 cc of a 3.5 wt% methanol solution of Compound 7, Compound 7 was 7 × 10 5 per mole of silver.^-3Mole 6.4 × 10 mol of compound 8 per mole of silver^-3Mole was added to make silver halide emulsion 1.
[0212]
<< Preparation of silver halide grains 2 >>
In the preparation of silver halide emulsion 1, pure silver bromide cubic grains with an average equivalent sphere diameter of 0.08μm and a variation coefficient of 15% of the equivalent sphere diameter were the same except that the liquid temperature at the time of grain formation was changed to 37 ° C. An emulsion was prepared. Precipitation / desalting / washing / dispersion was carried out in the same manner as silver halide emulsion 1. Furthermore, the amount of spectral sensitizing dye A added is 4.5 x 10 per mole of silver.^-3A silver halide emulsion 2 was obtained by carrying out spectral sensitization, chemical sensitization and addition of compound 3 and compound 8 in the same manner as emulsion 1 except that the molar ratio was changed.
[0213]
<< Preparation of silver halide grains 3 >>
In the preparation of silver halide emulsion 1, pure silver bromide cubic grains having an average equivalent sphere diameter of 0.038μm and a variation coefficient of 20% of the equivalent sphere diameter were the same except that the liquid temperature at the time of grain formation was changed to 37 ° C. An emulsion was prepared. Precipitation / desalting / washing / dispersion was carried out in the same manner as silver halide emulsion 1. Furthermore, the addition amount of spectral sensitizing dye A is 6 × 10 6 per mol of silver.^-3A silver halide emulsion 3 was obtained by carrying out spectral sensitization, chemical sensitization and addition of compound 3 and compound 8 in the same manner as emulsion 1 except that the molar ratio was changed.
<Preparation of mixed emulsion A for coating solution>
70% by weight of silver halide emulsion 1, 15% by weight of silver halide emulsion 2 and 15% by weight of silver halide emulsion 3 were dissolved, and compound 9 was dissolved in a 1% by weight aqueous solution at 7 × 10 5 per mole of silver.^-3Mole was added.
[0214]
<< Preparation of flake fatty acid silver salt >>
Henkel behenic acid (product name Edenor C22-85R) 87.6g, distilled water 423ml, 5N-NaOH aqueous solution 49.2ml, tert-butanol 120ml was mixed and stirred at 75 ° C for 1 hour to react with sodium behenate solution. Obtained. Separately, 206.2 ml (pH 4.0) of an aqueous solution of 40.4 g of silver nitrate was prepared and kept warm at 10 ° C. A reaction vessel containing 635 ml of distilled water and 30 ml of tert-butanol is kept at 30 ° C., and while stirring, the total amount of the previous sodium behenate solution and the total amount of silver nitrate aqueous solution are 62 minutes 10 seconds and 60 minutes, respectively, at a constant flow rate. Added over time. At this time, only the silver nitrate aqueous solution is added for 7 minutes and 20 seconds after the start of the addition of the silver nitrate aqueous solution, and then the addition of the sodium behenate solution is started. After the addition of the silver nitrate aqueous solution, only the sodium behenate solution is added for 9 minutes and 30 seconds Was added. At this time, the temperature in the reaction vessel was 30 ° C., and the external temperature was controlled so that the liquid temperature was constant. Further, the pipe of the addition system of the sodium behenate solution was kept warm by steam tracing, and the steam opening degree was adjusted so that the liquid temperature at the outlet of the addition nozzle tip was 75 ° C. Moreover, the piping of the addition system of the silver nitrate aqueous solution was kept warm by circulating cold water outside the double pipe. The addition position of the sodium behenate solution and the addition position of the aqueous silver nitrate solution were arranged symmetrically around the stirring axis, and were adjusted so as not to contact the reaction solution.
[0215]
After completion of the addition of the sodium behenate solution, the mixture was left stirring for 20 minutes at the same temperature, 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 reached 30 μS / cm. Thus, a fatty acid silver salt was obtained. The obtained solid content was stored as a wet cake without drying.
[0216]
When the morphology of the obtained silver behenate particles was evaluated by electron micrograph, the average values were a = 0.14 μm, b = 0.4 μm, c = 0.6 μm, average aspect ratio 5.2, average sphere equivalent diameter 0.52 μm, equivalent to sphere It was a flake-like crystal with a diameter variation coefficient of 15%. (A, b, and c are the provisions of the text)
[0217]
7.4 g of polyvinyl alcohol (trade name: PVA-205) and water were added to the wet cake equivalent to 100 g of the dry solid content to make the total amount 385 g, and then pre-dispersed with a homomixer.
[0218]
Next, the pre-dispersed stock solution is subjected to a pressure of 1750 kg / cm of the disperser (trade name: Microfluidizer M-110S-EH, manufactured by Microfluidics International Corporation, G10Z interaction chamber).²And was treated three times to obtain a silver behenate dispersion. The cooling operation was set to a dispersion temperature of 18 ° C. by installing a serpentine heat exchanger before and after the interaction chamber and adjusting the temperature of the refrigerant.
[0219]
<Preparation of 25 wt% dispersion of reducing agent>
10 kg of 20% aqueous solution of 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane and modified polyvinyl alcohol (Kuraray Co., Ltd., Poval MP203), 16 kg of water Was added and mixed well to obtain a slurry. This slurry was fed with a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 3 hours and 30 minutes. The concentration was adjusted to 25 wt% to obtain a reducing agent dispersion. The reducing agent particles contained in the reducing agent dispersion thus obtained 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.
[0220]
<Preparation of 10 wt% dispersion of mercapto compound>
8.3 kg of water was added to 5 kg of an aqueous solution of 5 kg of Compound 8 and 20 wt% aqueous solution of modified polyvinyl alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.) and mixed well to prepare a slurry. This slurry is fed with a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 6 hours, and then water is added to increase the concentration of the mercapto compound. A mercapto dispersion was obtained by adjusting to 10 wt%. The mercapto compound particles contained in the mercapto compound dispersion thus obtained had a median diameter of 0.40 μm and a maximum particle diameter of 2.0 μm or less. The obtained 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.
[0221]
<< Preparation of Organic Polyhalogen Compound 20wt% Dispersion-1 >>
5 kg of tribromomethylnaphthyl sulfone, 2.5 kg of 20 wt% aqueous solution of modified polyvinyl alcohol (Kuraray Co., Ltd., POVAL MP203), 213 g of 20 wt% aqueous solution of sodium triisopropylnaphthalene sulfonate, 0.2 g of compound 10 and 10 kg of water Add and mix well to make a slurry. This slurry was fed with a diaphragm pump and dispersed for 5 hours in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm. Then, water was added to the organic polyhalogen compound. The concentration was adjusted to 20 wt% to obtain an organic polyhalogen compound dispersion. The organic polyhalogen compound particles contained in the polyhalogen compound dispersion thus obtained had a median diameter of 0.36 μm and a maximum particle diameter of 2.0 μm or less. The obtained organic polyhalogen compound dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust and stored.
[0222]
<< Preparation of Organic Polyhalogen Compound 20wt% Dispersion-2 >>
Similar to 20 wt% dispersion-1 of organic polyhalogen compound, except that 5 kg of tribromomethyl (4- (2,4,6-trimethylphenylsulfonyl) phenyl) sulfone is used instead of 5 kg of tribromomethylnaphthylsulfone, Dispersion and filtration were performed. The organic polyhalogen compound particles contained in the organic polyhalogen compound dispersion thus obtained had a median diameter of 0.38 μm and a maximum particle diameter of 2.0 μm or less. The obtained organic polyhalogen compound dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust and stored.
[0223]
<< Preparation of 20 wt% Dispersion-3 of Organic Polyhalogen Compound >>
Dispersion and filtration were performed in the same manner as 20 wt% dispersion-1 of organic polyhalogen compound, except that 5 kg of tribromomethylphenylsulfone was used instead of 5 kg of tribromomethylnaphthylsulfone. The organic polyhalogen compound particles contained in the organic polyhalogen compound dispersion thus obtained had a median diameter of 0.41 μm and a maximum particle diameter of 2.0 μm or less. The obtained organic polyhalogen compound dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust and stored.
[0224]
<< Preparation of 10wt% methanol solution of phthalazine compound >>
10 g of 6-isopropylphthalazine was dissolved in 90 g of methanol and used.
[0225]
<< Preparation of 20wt% dispersion of pigment >>
C.I. Pigment Blue 60 (64 g) and Kao Corp. demole N (6.4 g) were added to 6.4 g of water (250 g) and mixed well to form a slurry. 800 g of zirconia beads having an average diameter of 0.5 mm were prepared and placed in a vessel together with the slurry, and dispersed for 25 hours with a disperser (1/4 G sand grinder mill: manufactured by IMEX Co., Ltd.) to obtain a pigment dispersion. The pigment particles contained in the pigment dispersion thus obtained had an average particle size of 0.21 μm.
[0226]
<< Preparation of SBR Latex 40wt% >>
The ultrafiltration (UF) purified SBR latex was obtained as follows.
The following SBR latex diluted 10 times with distilled water is diluted with UF-Purification Module FS03-FC-FUY03A1 (Daisen Membrane System Co., Ltd.) until the ionic conductivity reaches 1.5mS / cm. The purified product was used. The latex concentration at this time was 40 wt%.
(SBR latex: Latex of -St (68) -Bu (29) -AA (3)-)
[0227]
Average particle size 0.1μm, concentration 45%, equilibrium water content 0.6wt% at 25 ° C 60% RH, ion conductivity 4.2mS / cm (Ion conductivity is measured by Toa Radio Industry Co., Ltd. conductivity meter CM-30S Use latex stock solution (40%) measured at 25 ° C), pH 8.2
[0228]
<< Preparation of emulsion layer (photosensitive layer) coating solution >>
1.1 g of 20 wt% aqueous dispersion of the pigment obtained above, 103 g of organic acid silver dispersion, 5 g of 20 wt% aqueous solution of polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.), 25 g of 25 wt% reducing agent dispersion, organic Polyhalogen compound 20wt% Dispersion-1, -2, -3 5: 1: 3 (weight ratio) 11.5g in total, Mercapto compound 10% dispersion 6.2g, ultrafiltration (UF) purified SBR latex 40wt 106 g of 10%, 16 ml of 10 wt% methanol solution of phthalazine compound, and 10 g of silver halide mixed emulsion A were mixed well to prepare an emulsion layer coating solution.²Then, the solution was fed and applied.
[0229]
The viscosity of the emulsion layer coating solution was 85 [mPa · s] at 40 ° C. (No. 1 rotor) as measured with a B-type viscometer of Tokyo Keiki.
[0230]
The viscosity of the coating solution at 25 ° C using an RFS fluid spectrometer manufactured by Rheometrics Far East Co., Ltd. is 0.1, 1, 10, 100, 1000 [1 / sec] at a shear rate.
Respectively, 1500, 220, 70, 40, and 20 [mPa · s].
[0231]
<Preparation of emulsion surface intermediate layer coating solution>
Add 77g of 20wt% dispersion of pigment and 2ml of 5wt% aqueous solution of Aerosol OT (American Cyanamid) to 772g of 10wt% aqueous solution of polyvinyl alcohol PVA-205 (Kuraray Co., Ltd.) to make a total amount of 1000g Add water to make the intermediate layer coating solution, 5 ml / m²Then, the solution was fed to the coating die.
The viscosity of the coating solution was 21 [mPa · s] at a B-type viscometer of 40 ° C. (No. 1 rotor).
[0232]
<< Preparation of emulsion surface protective layer first layer coating solution >>
64 g of inert gelatin is dissolved in water, latex (described in Table 1), 64 ml of 10 wt% methanol solution of phthalic acid, 74 ml of 10 wt% aqueous solution of 4-methylphthalic acid, 28 ml of 1N sulfuric acid, aerosol OT (American Cyana) 5 ml of 5 wt% aqueous solution (Mido) and 1 g of phenoxyethanol, add water to a total volume of 1000 g to make the coating solution, 10 ml / m²Then, the solution was fed to the coating die.
The viscosity of the coating solution was 17 [mPa · s] at 40 ° C. (No. 1 rotor) with a B-type viscometer.
[0233]
<< Preparation of emulsion surface protective layer second layer coating solution >>
80 g of inert gelatin is dissolved in water, latex (described in Table 1), 20 ml of a 5 wt% solution of N-perfluorooctylsulfonyl-N-propylalanine potassium salt, polyethylene glycol mono (N-perfluorooctylsulfonyl-N- 50 ml of 2 wt% aqueous solution of propyl-2-aminoethyl) ether [ethylene oxide average polymerization degree = 15], 16 ml of 5 wt% solution of aerosol OT (American Cyanamid Co., Ltd.), polymethyl methacrylate fine particles (average particle size 0.7 μm) 4 g, polymethyl methacrylate fine particles (average particle size 6.4 μm) 21 g, 4-methylphthalic acid 1.6 g, phthalic acid 8.1 g, 1N sulfuric acid 44 ml, benzoisothiazolinone 10 mg and water added to a total amount of 1555 g Then, 445 ml of an aqueous solution containing 4 wt% chromium alum and 0.67 wt% phthalic acid was mixed with a static mixer immediately before coating to form a surface protective layer coating solution, 10 ml / m²Then, the solution was fed to the coating die.
The viscosity of the coating solution was 9 [mPa · s] at 40 ° C. (No. 1 rotor) with a B-type viscometer.
[0234]
<Creation of photothermographic material>
On the back surface side of the undercoat support, the antihalation layer coating solution has a solid content of solid particulate dye of 0.04 g / m.²In addition, the coating amount of the back surface protective layer is 1 g / m for the gelatin coating amount.²Then, simultaneous multilayer coating was applied and dried to prepare an antihalation back layer.
[0235]
Emulsion layer from the undercoat surface to the surface opposite the back surface (silver halide coating silver amount 0.14 g / m²), An intermediate layer, a protective layer first layer, and a protective layer second layer were simultaneously applied in the order of a slide bead coating method to prepare a photothermographic material sample.
[0236]
Application is performed at a speed of 160 m / min, the distance between the coating die tip and the support is 0.18 mm, and the application width is adjusted to be 0.5 mm wider on both the left and right sides of the discharge slit width of the coating solution. Was set to 392 Pa lower than the atmospheric pressure. At that time, handling and temperature / humidity were controlled so that the support was not charged. In the subsequent chilling zone, air with a dry bulb temperature of 18 ° C and a wet bulb temperature of 12 ° C was blown for 30 seconds to cool the coating solution, and then the dry bulb temperature was changed in the suspension-type floating drying zone. After blowing dry air of 30 ° C. and wet bulb temperature of 18 ° C. for 200 seconds, passing through a 70 ° C. drying zone for 30 seconds and then cooling to 25 ° C., the solvent in the coating solution was volatilized. The average wind speed of the wind sprayed on the coating liquid film surface in the chilling zone and the drying zone was 7 m / sec.
[0237]
[Chemical 1]

[0238]
[Chemical 2]

[0239]
[Chemical 3]

[0240]
(Measurement of elongation at break of each layer single film)
The coating solution for each layer was applied on a Teflon base so that the dry film thickness was 25.0 μm. After drying it at 30 ° C., only the coating film was peeled off from the Teflon base to prepare a single film. Next, the elongation at break of this single membrane was measured as follows.
The film is cut to a predetermined size (5 mm × 50 mm), and the temperature is adjusted to the heat development temperature (120 ° C.) for 5 minutes.
The sample was attached to a tensile tester (Orientec Co., Ltd .: tensile tester RTM-100) and pulled at a pulling rate of 100 mm / min until the membrane broke.
The elongation at break is
(AB) / B × 100%
A: Length when the sample breaks after being pulled with the sample length between the fixtures of the tensile tester
B: Calculated by the length before pulling by the sample length between the fixtures of the tensile tester.
[0241]
(Evaluation of cracks)
A sample of the photothermographic material thus prepared was subjected to a load of 50 g with a stainless needle with a 0.5 mm tip on the emulsion surface side at 25 ° C. and 60% RH (relative humidity). Then, the chest diagnostic image was exposed using the following laser sensitometer. Thereafter, thermal development was performed at 120 ° C. for 20 seconds with the plate heater type thermal development apparatus 10 shown in FIG. 1 of Example No. 9-229684, and visually evaluated. However, the odor was extinguished using a metal mesh and activated carbon filter.
[0242]

[0243]
○: No white spots in the image area, no cracks in the protective layer and the image forming layer, and good
Δ: There are no white spots in the image area, but there are some cracks in the protective layer and the image forming layer.
X: There are cracks in the protective layer and the image forming layer, and there are white spots in the image area (this is a problem.
)
[0244]
[Table 1]

[0245]
From Table 1, the effect of the present invention is clear. Further, the sample of the present invention was excellent in preventing thermal cracking.
[0246]
Example 2
Similar to Sample 102 of Example 1, except that the emulsion layer was prepared using the following latexes Lb1 and Lc1 (both having an equilibrium water content of less than 2 wt%) instead of SBR latex.
[0247]
(Synthesis of Lb1)
In a glass autoclave (TEM-V1000 manufactured by Pressure Glass Industrial Co., Ltd.), 140 g of styrene, 280 g of distilled water, 4.44 g of a surfactant (Sandet BL (manufactured by Sanyo Kasei Co., Ltd.)), 6 g of acrylic acid, and under nitrogen flow For 1 hour. Thereafter, 54 g of 2-ethylhexyl acrylate was added, and the temperature was raised to 70 ° C. Next, 20 g of an aqueous ammonium persulfate solution (5 wt%) was added, and the mixture was stirred for 10 hours. Thereafter, the temperature of the reaction vessel was lowered to room temperature to obtain a styrene-acrylic latex. A 1N aqueous ammonia solution was added to the latex to adjust the pH to 7.5.
[0248]
Thus, latex (Lb1) having an average particle size of 98 nm and a concentration of 42 wt% was obtained. The equilibrium water content of the polymer at 25 ° C and 60% RH was 0.7wt%.
[0249]
(Synthesis of Lc1)
A glass autoclave (TEM-V1000 manufactured by Pressure Glass Industry Co., Ltd.) is charged with 126 g of methyl methacrylate, 280 g of distilled water, 8.2 g of a surfactant (Sandet BL (manufactured by Sanyo Kasei Co., Ltd.)), 4 g of acrylic acid, and a nitrogen stream. Stir for 1 hour under. Thereafter, 70 g of ethyl acrylate was added, and the temperature was raised to 60 ° C. Next, 20 g of an aqueous potassium persulfate solution (5 wt%) was added and stirred as it was for 10 hours. Thereafter, the temperature of the reaction vessel was lowered to room temperature to obtain an acrylic latex. A 1N aqueous ammonia solution was added to the latex to adjust the pH to 7.5.
[0250]
Thus, latex (Lc1) having an average particle diameter of 101 nm and a concentration of 44 wt% was obtained. The equilibrium water content of the polymer at 25 ° C and 60% RH was 0.7wt%.
[0251]
A sample using Lb1 is a sample 201, and a sample using Lc1 is a sample 202. In these samples, the same results as in Example 1 were obtained.
[0252]
Example 3
As in Example 1, except that SBR latex is NH in the final synthesis step._FourThe pH was adjusted to 8.0 with OH and NaOH (1: 1 (weight ratio)), and the UF purified product was not used. The effect was the same as in Example 1.
[0253]
【The invention's effect】
According to the present invention, generation of cracks and white spots during heat development can be prevented.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a plate heater type heat development section.
FIG. 2 is a schematic cross-sectional view of a plate heater type heat development unit.
[Explanation of symbols]
18 Thermal development section
120 plate heater
122 Presser roller
130 Driving roller

Claims (4)

A heat having a photosensitive layer containing at least a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on the support, and at least one non-photosensitive layer thereon. In the development photosensitive material, the at least one non-photosensitive layer contains a water-soluble polymer and a polymer having a glass transition temperature Tg of 20 ° C. or more and 80 ° C. or less, and the content of Tg is 20 ° C. or more and 80 ° C. or less. A photothermographic material characterized by being 5 wt% or more and 50 wt% or less of the total binder of the total non-photosensitive layer.   A heat having a photosensitive layer containing at least a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on the support, and at least one non-photosensitive layer thereon. 2. The photothermographic material according to claim 1, wherein the at least one non-photosensitive layer has a breaking elongation at a heat development temperature of 5% or more and 25% or less. 3. The photothermographic material according to claim 1, wherein the non-photosensitive layer is coated with an aqueous solvent, and a polymer having a Tg of 20 ° C. or more and 80 ° C. or less is contained in the aqueous solvent as a latex. . 50% by weight or more of the total binder of the photosensitive layer is a polymer having an equilibrium water content of 2% by weight or less at 25 ° C. and 60% RH, the photosensitive layer is coated with an aqueous solvent, and Tg is 20 ° C. 4. The photothermographic material according to claim 1, wherein a polymer having a temperature of 80 ° C. or lower is contained in the aqueous solvent as a latex.

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