JP3830059B2 - Image forming material - Google Patents

Description

【０１２０】
(写真性能の評価）
647nmKrレーザー感光計(最大出力500mW)で法線に対して30度の斜度で感光材料を露光した後、感光材料を125℃で15秒間処理(現像）し、得られた画像の評価を濃度計により行った。測定の結果は、Dmin（カブリ）、感度(Dminより1.0高い濃度を与える露光量の比の逆数）で評価した。感度については感光材料１−１の感度を100とした。
【０１２１】
また、濃度１となる領域の画像色調を下記の基準で目視にて評価した。
【０１２２】
◎・・・冷黒調。
○・・・微かに暖調であるが気にならない。
△・・・暖調であるが実用的に許容される。
×・・・著しく暖調であり不可。
【０１２３】
(強制経時保存性の評価）
それぞれの感光材料を30.5cm×25.4cmに裁断し角を内径0.5cmのラウンドコーナーとし、25℃-50%RHの条件下1日放置し、感光材料それぞれ10枚ずつを防湿材料でできた袋の中に密閉し、さらに35.1cm×26.9cm×3.0cmの化粧箱に入れ、50℃で5日間経時した(強制経時）。このようにした感光材料の写真性能と同様に現像処理し、Dminを評価した。
【０１２４】
各感光材料について上記評価を実施した結果を表1に示す。
【０１２５】
【表１】

【０１２６】
表１より、本発明の領域で感度、Dmin、色調、強制経時保存性に優れることがわかる。また、上記の感光材料について１万ｌｘ、４０℃−６０％ＲＨの条件下で３日間保存して、光画像保存性を調べたところ、感光材料１−１はＤmin部の濃度が０．７０まで上昇したのに対して、感光材料１−２〜９は０．１５以下であり、光画像保存性に優れることがわかった。
【０１２７】
実施例２
実施例１の感光材料1-3において乳剤面保護層のゼラチンをポリメタクリレート、ポリメタクリレート／ポリブチルアクリレート共重合体、カルボキシメチルセルロースに換え実施例1と同様の評価をしたところ感度は感光材料1-3に対して各々5%、8%、10%低い以外は感光材料1-3と同等の良好な性能が得られた。
【０１２８】
比較例１
実施例１の感光材料1-3において4-メチルフタル酸を除去したところ、全く像が得られなかった。
【０１２９】
実施例３
実施例１の感光材料１−３において、４−メチルフタル酸を等モルのフタル酸に置き換えたところ感度は感光材料1-3に対して5%低い以外は感光材料1-3と同等の良好な性能が得られた。
【０１３０】
参考例４
実施例１の感光材料1-3において硫酸アルミニウムを乳剤面保護層に添加せず、同量の硫酸アルミニウムを画像形成層に添加したところ感度は感光材料1-3に対して7%低く、強制経時保存性でのカブリが0.10となった以外は感光材料1-3と同等の良好な性能が得られた。
【０１３１】
実施例５
実施例１の感光材料1-1、1-3の乳剤層塗布液にN-(2-メトキシフェニル）-N'-ホルミルヒドラジンを塗布量1mg/m²となるように添加し感光材料2-1、2-2を調製した。
【０１３２】
こうして得た感光材料を647nmKrレーザー感光計(最大出力500mW)で法線に対して30度の斜度で辺が1cmの正方形を露光したときの濃度が2.5となる露光量を露光量xおよび0.5となる露光量を露光量yとしたとき、短辺100μm長辺1cmの長方形の長辺が接するように露光量xと露光量yで交互に露光し、現像温度を115℃とした以外は実施例1の写真性評価の際と同様に処理したものを遮光した条件下40℃で1月間放置した後の画像の様子を下記の基準で目視評価したところ、感光材料2-1(比較例）は×、感光材料2-2(本発明）は◎であり、本発明の領域で画像保存性に優れることがわかった。
【０１３３】
◎・・・ほとんど変化がない。
○・・・微かに画像部が拡大しているが気にならない。
△・・・画像部が5μm以上拡大しているが実用的に許容される。
×・・・画像部が20μm以上拡大しているため不可。
【０１３４】
また、本発明の感光材料２−２について、実施例１に準じて、写真性能および強制経時保存性を評価したところ、良好であることがわかった。また、γも高く硬調性も十分であった。
【０１３５】
実施例６
実施例１において乳剤層塗布液中のハロゲン化銀を添加せず、還元剤分散物の代わりに等モルの3,4-ジヒドロキシ安息香酸メチルを水溶液で添加し、画像形成層保護層には多価金属イオンの塩を添加せず、さらにバック面の塩基液ならびに染料液を添加しなかったものを感熱画像形成材料（感熱材料）とした。なお、画像形成面の層には表２のように多価金属イオンの塩を添加した。こうして得た感熱材料に対して95℃4秒で加熱したときの濃度ならびに実施例1と同様の強制経時保存をした後の95℃4秒で加熱時濃度を表２に示す。
【０１３６】
また、濃度１となる加温での画像色調を実施例１の基準で目視にて評価した。
【０１３７】
結果を表２に示す。
【０１３８】
【表２】

【０１３９】
表２より、本発明の領域で高濃度、冷黒調であり、保存性に優れることがわかる。
【０１４０】
【発明の効果】
本発明によれば、感度、カブリ、画像色調が良好で保存性の優れた画像形成材料が得られる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming material.
[0002]
[Prior art]
In recent years, computer network systems have been completed in the medical field, and image output devices have been handled in the same way as many precision machines. Conventional laser imagesetters or laser imagers are corrosive. There is concern about the deterioration of various precision instruments that have developing and fixing solutions. On the other hand, there are many problems such as environmental destruction due to waste liquids from these treatments, and inability to perform processing in the absence of water at the time of a disaster, and an image forming system without treatment liquids is strongly desired. Therefore, there is a need for a technique relating to a photothermographic image forming material for medical diagnosis and photographic technology capable of forming a black image having high resolution and sharpness, or a heat sensitive image forming material for forming an image with a heating head. ing. These thermal image forming materials can eliminate the use of solution processing chemicals and supply customers with an image forming system that is simpler and does not impair the environment.
[0003]
Although there is a similar requirement in the field of general imaging materials, medical images are required to have fine image quality because they require fine depiction. 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 generally distributed as modeling systems, but there is no satisfactory output system for medical images.
[0004]
On the other hand, thermal imaging systems using organic silver salts are disclosed in many documents including US Pat. No. 2910377 and Japanese Patent Publication No. 43-4924. Thermal image forming systems using these organic silver salts can achieve image quality and color tone that are satisfactory as medical images, but the image forming ability of the material may change before image formation, or light, heat, There is a problem that the image is altered by water or the like.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide an image forming material that is excellent in preservability and handling properties before and after image formation, and gives a high-quality, cool-black image.
[0006]
[Means for Solving the Problems]
This object has been achieved by the following means.
(1) An image forming layer containing an organic silver salt, a photosensitive silver halide and a reducing agent on one surface of the support, and any one of the surfaces having the image forming layer of the support (image forming layer) In addition, a polyvalent metal ion of a metal selected from each group of the periodic tables 3 to 12 (3A to 7A, 8, 1B, 2B) and an element of the periodic table 13 (3B) group, phthalic acid, 4 An image forming characterized in that it is a photosensitive heat-developable image forming material having a compound selected from methylphthalic acid, 4-nitrophthalic acid, tetrachlorophthalic anhydride, 2,3-dicarboxynaphthalene and metal salts thereof material.
(2) A compound selected from the polyvalent metal ions and the phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, tetrachlorophthalic anhydride, 2,3-dicarboxynaphthalene, and metal salts thereof is subtracted. The image forming material according to (1), which is contained in a layer, an intermediate layer, a protective layer, or an overcoat layer.
(3) A protective layer comprising a compound selected from the polyvalent metal ions and the phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, tetrachlorophthalic anhydride, 2,3-dicarboxynaphthalene, and metal salts thereof. Or it is contained in an overcoat layer, The image forming material as described in (1) characterized by the above-mentioned.
(4) The polyvalent metal ion is aluminum (III), chromium (III), palladium (II), zirconium (II), zinc (II) or manganese (II). The image forming material according to any one of (3).
(5) The image according to any one of (1) to (4), wherein the polyvalent metal ion is a mineral acid or an organic acid salt added as an aqueous solution to the coating solution. Forming material.
(6) The image forming material as described in any one of (1) to (5), wherein the polyvalent metal ion is sulfate, acetate or nitrate.
(7) Content of the polyvalent metal ion is 1 m ² The image forming material according to any one of (1) to (6), wherein the amount is from 10 to 1 mol per mol.
(8) The image forming material as described in any one of (1) to (7), wherein the surface having the image forming layer has a film surface pH of 4.5 or less and 1.0 or more.
(9) 100 mg / m on the uppermost layer of the surface having the image forming layer of the support ² 5 g / m or more ² The image forming material according to any one of (1) to (8), which has the following carboxylic acid residue-containing polymer.
(10) The image forming material according to any one of (1) to (9), wherein the image forming material forms a silver image.
(11) Organic silver on one side of the support Salt And any one of the surfaces having the image forming layer of the support (excluding the image forming layer), the periodic tables 3 to 12 (3A to 7A, 8, 1B, 2B) and polyvalent metal ions of metals selected from the elements of Group 13 (3B) of the periodic table, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, tetrachlorophthalic anhydride, 2,3- An image-forming material comprising a heat-sensitive image-forming material having a compound selected from dicarboxynaphthalene and a metal salt thereof.
(12) A compound selected from the polyvalent metal ions and the phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, tetrachlorophthalic anhydride, 2,3-dicarboxynaphthalene, and metal salts thereof is subtracted. The image forming material according to (11), which is contained in a layer, an intermediate layer, a protective layer, or an overcoat layer.
(13) The compound selected from the polyvalent metal ions and the phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, tetrachlorophthalic anhydride, 2,3-dicarboxynaphthalene, and metal salts thereof is a protective layer. Or it is contained in an overcoat layer, The image forming material as described in (11) characterized by the above-mentioned.
(14) The polyvalent metal ion is aluminum (III), chromium (III), palladium (II), zirconium (II), zinc (II) or manganese (II), The image forming material according to any one of (13).
(15) The image according to any one of (11) to (14), wherein the polyvalent metal ion is a mineral acid or an organic acid salt added as an aqueous solution to the coating solution. Forming material.
(16) The image forming material as described in any one of (11) to (15), wherein the polyvalent metal ion is sulfate, acetate or nitrate.
(17) The content of the polyvalent metal ion is 1 m ² The image forming material according to any one of (11) to (16), which is 10 μmol or more and 1 mol or less per unit.
(18) The image forming material as described in any one of (11) to (17), wherein a film surface pH of the surface having the image forming layer is 4.5 or less and 1.0 or more.
(19) The image forming material as described in any one of (11) to (18), wherein the image forming material forms a silver image.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in detail below.
[0008]
The image forming material of the present invention has an organic silver salt on one side of a support. , Containing photosensitive silver halide and reducing agent A photosensitive heat-developable image-forming material or heat-sensitive image-forming material having an image-forming layer, on the image-forming layer-side surface of the support Any of the layers (excluding the image-forming layer) ( Protective layer, overcoat layer, etc. as described below Specific layer of ) Of metals selected from each group of periodic table 3-12 (3A-7A, 8, 1B, 2B) and periodic table 13 (3B) group Polyvalent metal ion (Hereafter referred to as polyvalent metal ions) When, Compounds selected from phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, tetrachlorophthalic anhydride, 2,3-dicarboxynaphthalene and metal salts thereof (hereinafter referred to as phthalic acids) Have
[0009]
By using a polyvalent metal ion and phthalic acid in combination, an image having excellent photographic performance, no deterioration in photographic performance due to storage, and excellent image color tone can be obtained. On the other hand, if the polyvalent metal ions are not added, the image color tone is deteriorated and the photographic performance before and after storage is deteriorated. Further, if phthalic acids are not added, image formation cannot be seen.
[0010]
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. Silver salts of organic acids, particularly silver salts of long-chain fatty carboxylic acids (having 10 to 30, preferably 15 to 28 carbon atoms) are preferred.
. Preference is also given to organic or inorganic silver salt complexes in which the ligand has a complex stability constant in the range of 4.0 to 10.0. The silver supply material can preferably comprise about 5 to 70% by weight of the imaging 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 camphorate, mixtures thereof, and the like.
[0011]
Silver salts of compounds containing a mercapto group or a thione group and derivatives thereof can also be used. Preferred examples of these compounds include silver salt of 3-mercapto-4-phenyl-1,2,4-triazole, silver salt of 2-mercaptobenzimidazole, silver salt of 2-mercapto-5-aminothiadiazole, 2 Silver salt of thioglycolic acid such as silver salt of-(ethylglycolamide) benzothiazole, silver salt of S-alkylthioglycolic acid (wherein the alkyl group has 12 to 22 carbon atoms), silver salt of dithioacetic acid, etc. Silver salt of dithiocarboxylic acid, silver salt of thioamide, silver salt of 5-carboxyl-1-methyl-2-phenyl-4-thiopyridine, silver salt of mercaptotriazine, silver salt of 2-mercaptobenzoxazole, U.S. Patent 4,123,274 Silver salts of 1,2,4-mercaptothiazole derivatives such as silver salts of 3-amino-5-benzylthio-1,2,4-thiazole, and the like described in US Pat. No. 3,301,678. (3-carboxyethyl) -4-me Including silver salts of thione compounds such as silver salt of til-4-thiazoline-2-thione. Furthermore, a compound containing an imino group can also be used. Preferred examples of these compounds include silver salts of benzotriazole and derivatives thereof, for example, silver salts of benzotriazole such as silver methylbenzotriazole, silver salts of halogen-substituted benzotriazole such as silver 5-chlorobenzotriazole, US Patent 1,2,4-triazole or silver salt of 1-H-tetrazole as described in US Pat. No. 4,220,709, and silver salts of imidazole and imidazole derivatives. For example, various silver acetylide compounds described in US Pat. Nos. 4,761,361 and 4,775,613 can also be used.
[0012]
Although there is no restriction | limiting in particular as a shape of the organic silver salt which can be used for this invention, The acicular crystal | crystallization which has a short axis and a long axis is preferable. In the present invention, the minor axis is preferably 0.01 μm to 0.20 μm, the major axis is 0.10 μm to 5.0 μm, the minor axis is 0.01 μm to 0.15 μm, and the major axis is 0.10 μm to 4.0 μm. The particle size distribution of the organic silver salt is preferably monodispersed. Monodispersion is preferably a percentage of a value obtained by dividing the standard deviation of the lengths of the minor axis and the major axis by the minor axis and the major axis, respectively, preferably 100% or less, more preferably 80% or less, and still more preferably 50% or less. is there. 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 an organic silver salt dispersed in a liquid with a laser beam and obtaining an autocorrelation function with respect to temporal change of fluctuation of the scattered light. Can do.
[0013]
The organic silver salt that can be used in the present invention can be preferably desalted. There is no particular limitation on the method for performing desalting, and a known method can be used, but a known filtration method such as circular filtration, suction filtration, ultrafiltration, and flock-forming water washing by agglomeration method can be preferably used. .
[0014]
For the purpose of obtaining fine particles having a small particle size and no aggregation, the organic silver salt that can be used in the present invention is a method of forming a solid fine particle dispersion using a dispersant. The method of dispersing the organic silver salt in the form of solid fine particles is carried out by using known finer means (for example, ball mill, vibration ball mill, planetary ball mill, sand mill, colloid mill, jet mill, roller mill, high-pressure homogenizer) in the presence of a dispersion aid. Used and mechanically dispersible.
[0015]
When organic 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, acryloylmethylpropane sulfonic acid Synthetic anionic polymers such as copolymers, semi-synthetic anionic polymers such as carboxymethyl starch and carboxymethyl cellulose, anionic polymers such as alginic acid and pectinic acid, anions described in JP-A-52-92716, WO88 / 04794, etc. Surfactants, compounds described in Japanese Patent Application No. 7-350753, or known anionic, nonionic, cationic surfactants, and other polyvinyl alcohol, polyvinyl pyrrolidone, carboxymethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose Known polymers such as Alternatively, a polymer compound existing in nature such as gelatin can be appropriately selected and used.
[0016]
Dispersing aid is generally mixed with organic silver salt powder or wet cake organic silver salt before dispersion, and sent to the disperser as a slurry. It is good also as an organic silver salt powder or a wet cake by heat-treating and the process by a solvent. The pH may be controlled with an appropriate pH adjusting agent before or during dispersion.
[0017]
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.
[0018]
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 gelatinized state using gelatin) with a hydrophilic colloid. You can also In addition, a preservative can be added for the purpose of preventing the propagation of various germs during storage.
[0019]
The organic silver salt of the present invention can be used in the desired amount, but the material 1m ² Indicated by the coating amount per unit, 0.1-5g / m as the amount of silver ² Is preferred, more preferably 1 to 3 g / m ² It is.
[0020]
The image forming material of the present invention contains a reducing agent for organic silver salt. Mu 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 are preferred. The reducing agent is preferably contained in an amount of 5 to 50% (mole), more preferably 10 to 40% (mole), based on 1 mol 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 large 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.
[0021]
In photothermographic materials using organic silver salts, a wide range of reducing agents are disclosed in JP-A-46-6074, 47-1238, 47-33621, 49-46427, 49-115540, 50-14334, 50-36110, 50-147711, 51-32632, 51-1023721, 51-32324, 51-51933, 52-84727, 55- 108654, 56-146133, 57-82828, 57-82829, JP-A-6-3793, U.S. Patent 3,667,9586, 3,679,426, 3,751,252, 3,751,255, 3,761,270 No. 3,782,949, No. 3,839,048, No. 3,928,686, No. 5,464,738, German Patent No. 2321328, European Patent No. 692732, and the like. For example, amidooximes such as phenylamidooxime, 2-thienylamidooxime and p-phenoxyphenylamidooxime; azines such as 4-hydroxy-3,5-dimethoxybenzaldehyde azine; 2,2-bis (hydroxymethyl) propionyl- Combinations of aliphatic carboxylic acid aryl hydrazides such as β-phenylhydrazine and ascorbic acid and ascorbic acid; combinations of polyhydroxybenzene and hydroxylamine, reductone and / or hydrazine (eg hydroquinone and bis (ethoxyethyl) ) Such as a combination of hydroxylamine, piperidinohexose reductone or formyl-4-methylphenylhydrazine); such as phenylhydroxamic acid, p-hydroxyphenylhydroxamic acid and β-arininhydroxamic acid. Any hydroxamic acid; a combination of azine and sulfonamidophenol (eg, phenothiazine and 2,6-dichloro-4-benzenesulfonamidophenol); ethyl-α-cyano-2-methylphenyl acetate, ethyl-α-cyanophenyl Α-Cyanophenylacetic acid derivatives such as acetate; 2,2-dihydroxy-1,1-binaphthyl, 6,6-dibromo-2,2-dihydroxy-1,1-binaphthyl and bis (2-hydroxy-1-naphthyl) Bis-β-naphthol as exemplified by methane; a combination of bis-β-naphthol and a 1,3-dihydroxybenzene derivative (such as 2,4-dihydroxybenzophenone or 2,4-dihydroxyacetophenone); 3-methyl 5-pyrazolones such as -1-phenyl-5-pyrazolone; dimethylaminohexose reductone, anhydrodihydroaminohexose reductone And reductones as exemplified by anhydrodihydropiperidone hexose reductone; sulfonamide phenol reducing agents such as 2,6-dichloro-4-benzenesulfonamidophenol and p-benzenesulfonamidophenol; 1,3-dione and the like; 2,2-dimethyl-7-t-butyl-6-hydroxychroman and other chromans; 2,6-dimethoxy-3,5-dicarboethoxy-1,4-dihydropyridine and other 1, 4-dihydropyridine; bisphenol (eg, bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 4,4-ethylidene- Bis (2-t-butyl-6-methylphenol), 1,1, -bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane and 2,2-bis (3, 5-dimethyl-4-hydroxyphenyl) propane etc.) Ascorbic acid derivatives (eg 1-ascorbyl palmitate, ascorbyl stearate); and aldehydes and ketones such as benzyl and biacetyl; 3-pyrazolidone and certain indan-1,3-diones; chromanols (such as tocopherols) and the like is there. Particularly preferred reducing agents are bisphenol and chromanol.
[0022]
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, vibrating ball mill, sand mill, colloid mill, jet mill, roller mill, etc.). A dispersion aid may be used when dispersing the solid fine particles.
[0023]
In the present invention, the phthalic acid, i.e. Chi Taric acid and its derivatives (for example, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, tetrachlorophthalic anhydride, 2,3-dicarboxynaphthalene and the like and metal salts thereof; Alkali metals such as K, alkaline earth metals such as Ca and Mg, transition metals such as Fe and Ni, etc.) must be used.
[0024]
The phthalic acids 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, vibrating ball mill, sand mill, colloid mill, jet mill, roller mill, etc.). A dispersion aid may be used when dispersing the solid fine particles.
[0025]
The phthalic acids of the present invention are preferably contained in an amount of 0.1 to 50% (mole), more preferably 0.5 to 20% (mole) per mole of silver, in the layer on the side having the image forming layer. When the amount of phthalic acid decreases, image formation becomes difficult, and when it increases too much, the color tone tends to turn red. As will be described later, phthalic acid may be used for adjusting the film surface pH, but such phthalic acid for the purpose is excluded from the above amount range.
[0026]
The phthalic acid may be added at any time, but it is preferably added to the coating solution immediately before coating. As an added layer of phthalic acids, subbing Layer, medium Interlayer, protective layer, overcoat layer, etc. Other than the image forming layer Any layer is acceptable.
[0027]
Inclusion of an additive known as a “toning agent” that improves the image may increase the optical density. The toning agent may also be advantageous in forming a black silver image. The toning agent is preferably contained in an amount of 0.1 to 50% (mole) per mole of silver on the surface having the image forming layer, and more preferably 0.5 to 20% (mole).
The toning agent may be a so-called precursor that is derivatized so as to have an effective function only during development.
[0028]
In image forming materials using organic silver salts, a wide range of colorants are disclosed in JP-A-46-6077, 47-10282, 49-5019, 49-5020, 49-91215, 49. -91215, 50-2524, 50-32927, 50-67132, 50-67641, 50-114217, 51-3223, 51-27923, 52-14788 No., 52-99813, 53-1020, 53-76020, 54-156524, 54-156525, 61-183642, JP 4-56848, JP 49-10727 No. 54-20333, US Pat. Nos. 3,080,254, 3,446,648, 3,782,941, 4,123,282, 4,510,236, British Patent 1380795, Belgian Patent 841910, and the like. Examples of toning agents are phthalimide and N-hydroxyphthalimide; succinimide, pyrazolin-5-one, and quinazolinone, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2,4-thiazolidinedione Cyclic imides such as: naphthalimide (eg, N-hydroxy-1,8-naphthalimide); cobalt complex (eg, cobalt hexamine trifluoroacetate); 3-mercapto-1,2,4-triazole, 2,4 Mercaptans, exemplified by 2-dimercaptopyrimidine, 3-mercapto-4,5-diphenyl-1,2,4-triazole and 2,5-dimercapto-1,3,4-thiadiazole; N- (aminomethyl) aryl Dicarboximide, (eg (N, N-dimethylaminomethyl) phthalimide and N, N- (dimethylaminomethyl) -naphthalene-2,3-dicarboximide); Blocked pyrazoles, isothiuronium derivatives and certain photobleaching agents (eg, N, N'-hexamethylenebis (1-carbamoyl-3,5-dimethylpyrazole), 1,8- (3,6-diazaoctane) bis (Isothiuronium trifluoroacetate) and 2-tribromomethylsulfonyl)-(benzothiazole)); and 3-ethyl-5 [(3-ethyl-2-benzothiazolinylidene) -1-methylethylidene]- 2-thio-2,4-oxazolidinedione; phthalazinone, phthalazinone derivatives or metal salts, or 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethoxyphthalazinone and 2,3-dihydro- Derivatives such as 1,4-phthalazinedione; phthalazine, phthalazine derivatives or metal salts, or 4- (1-naphthyl) phthalazine, 6-chlorophthalazine, 5,7-dimethoxyphthalazine and Derivatives such as 2,3-dihydrophthalazine; quinazolinedione, benzoxazine or naphthoxazine derivatives; rhodium complexes that function not only as color modifiers but also as a source of halide ions for in situ silver halide formation, such as Ammonium hexachlororhodium (III), rhodium bromide, rhodium nitrate and potassium hexachlororhodium (III), etc .; inorganic peroxides and persulfates such as ammonium peroxide disulfide and hydrogen peroxide; 1,3-benz Benzoxazine-2,4- such as oxazine-2,4-dione, 8-methyl-1,3-benzoxazine-2,4-dione and 6-nitro-1,3-benzoxazine-2,4-dione Diones; pyrimidines and asymmetric-triazines such as 2,4-dihydroxypyrimidine, 2-hydroxy-4-aminopyrimidine, azauracil, and Traazapentalene derivatives (eg, 3,6-dimercapto-1,4-diphenyl-1H, 4H-2,3a, 5,6a-tetraazapentalene, and 1,4-di (o-chlorophenyl) -3 , 6-dimercapto-1H, 4H-2,3a, 5,6a-tetraazapentalene) and the like are known.
[0029]
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, vibrating ball mill, sand mill, colloid mill, jet mill, roller mill, etc.). A dispersion aid may be used when dispersing the solid fine particles.
[0030]
At least one of the image forming layers of the present invention is preferably an image forming layer using the polymer latex described below at 50 wt% or more of the total binder (hereinafter, this image forming layer is referred to as “image forming layer of the present invention”, The polymer latex used for the binder is referred to as “polymer latex of the present invention”). However, the “polymer latex” mentioned here is a water-insoluble hydrophobic polymer dispersed as fine particles in a water-soluble dispersion medium. As the dispersion state, the polymer is emulsified in a dispersion medium, the emulsion is polymerized, the micelle is dispersed, or the polymer molecule has a partially hydrophilic structure and the molecular chain itself is molecularly dispersed. Anything may be used. As for the polymer latex of the present invention, `` synthetic resin emulsion (Hiraku Okuda, Hiroshi Inagaki, published by Kobunshi Publishing (1978)) '', `` Application of synthetic latex (Takaaki Sugimura, Ikuo Kataoka, Junichi Suzuki, Keiji Kasahara, Published by Polymer Publishing Association (1993)), “chemistry of synthetic latex (written by Soichi Muroi, published by Polymer Publishing Association (1970))”, and the like. The average particle size of the dispersed particles is preferably 1 to 50000 nm, more preferably about 5 to 1000 nm. The particle size distribution of the dispersed particles is not particularly limited, and may have a wide particle size distribution or a monodispersed particle size distribution.
[0031]
The polymer latex of the present invention may be a so-called core / shell type latex other than a normal polymer latex having a uniform structure. In this case, it may be preferable to change the glass transition temperature between the core and the shell.
[0032]
The minimum film forming temperature (MFT) of the polymer latex of the present invention is preferably -30 to 90 ° C, more preferably about 0 to 70 ° C. A film-forming auxiliary may be added to control the minimum film-forming temperature. A film-forming aid, also called a plasticizer, is an organic compound (usually an organic solvent) that lowers the minimum film-forming temperature of polymer latex. For example, “Synthetic latex chemistry (written by Soichi Muroi, published by Kobunshi Shuppankai (1970) )"It is described in.
Examples of the polymer species used in the polymer latex of the present invention include acrylic resins, vinyl acetate resins, polyester resins, polyurethane resins, rubber resins, vinyl chloride resins, vinylidene chloride resins, polyolefin resins, and copolymers thereof. 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 monomers. In the case of a copolymer, it may be a random copolymer or a block copolymer. The molecular weight of the polymer is a number average molecular weight of 5,000 to 100,000, preferably about 10,000 to 100,000. When the molecular weight is too small, the mechanical strength of the image forming layer is insufficient, and when the molecular weight is too large, the film formability is poor, which is not preferable.
[0033]
The polymer latex polymer used in the present invention preferably has an equilibrium water content of 2 wt% or less, more preferably 1 wt% or less at 25 ° C. and 60% RH. The lower limit is not particularly limited, but is preferably 0.01 wt%, more preferably 0.03 wt%. For the definition and measuring method of the equilibrium moisture content, for example, “Polymer Engineering Course 14, Polymer Material Testing Method (Edited by Polymer Society, Jinshokan)” can be referred to.
[0034]
Specific examples of the polymer latex used as the binder of the image forming layer of the image forming material of the present invention include the following. Methyl methacrylate / ethyl acrylate / methacrylic acid copolymer latex, methyl methacrylate / 2-ethylhexyl acrylate / styrene / acrylic acid copolymer latex, styrene / butadiene / acrylic acid copolymer latex, styrene / butadiene / divinylbenzene / methacrylic acid copolymer latex , Latex of methyl methacrylate / vinyl chloride / acrylic acid copolymer, latex of vinylidene chloride / ethyl acrylate / acrylonitrile / methacrylic acid copolymer, and the like. Moreover, such a polymer is also marketed and the following polymers can be utilized. For example, as an example of acrylic resin, Sebian A-4635,46583, 4601 (made by Daicel Chemical Industries, Ltd.), Nipol Lx811, 814, 821, 820, 857 (made by Nippon Zeon Co., Ltd.), etc. FINETEX ES650, 611, 675, 850 (Dainippon Ink Chemical Co., Ltd.), WD-size, WMS (Eastman Chemical), and other polyurethane resins are HYDRAN AP10, 20, 30, 40 (above Rubber resins such as LACSTAR 7310K, 3307B, 4700H, 7132C (above Dainippon Ink and Chemicals), Nipol Lx416, 410, 438C, 2507, (Zeon, Japan) Etc.), vinyl chloride resin G351, G576 (made by Nippon Zeon Co., Ltd.), vinylidene chloride resin L502, L513 (made by Asahi Kasei Kogyo Co., Ltd.), etc., olefin resin, Chemipearl S120 , SA100 (Mitsui Petrochemical Co., Ltd.) Rukoto can. These polymers may be used alone or in combination of two or more as required.
[0035]
In the image forming layer of the present invention, the polymer latex is used as 50 wt% or more of the total binder, but it is preferable to use the polymer latex as 70 wt% or more of the total binder.
[0036]
If necessary, a hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose, carboxymethylcellulose, hydroxypropylmethylcellulose or the like may be added to the image forming layer of the present invention within a range of 50 wt% or less of the total binder. The amount of these hydrophilic polymers added is preferably 30 wt% or less of the total binder in the image forming layer.
[0037]
The image forming layer of the present invention is preferably prepared by applying an aqueous coating solution and then drying it. However, “aqueous” as used herein means that 30 wt% or more of the solvent (dispersion medium) of the coating solution is water. As components other than water in the coating solution, water-miscible organic solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, and ethyl acetate can be used. Specific examples of the solvent composition include the following. Water / methanol = 90/10, water / methanol = 70/30, water / ethanol = 90/10, water / isopropanol = 90/10, water / dimethylformamide = 95/5, water / methanol / dimethylformamide = 80 / 15/5, water / methanol / dimethylformamide = 90/5/5. (However, the number represents wt%.)
[0038]
The total binder amount of the image forming layer of the present invention is 0.2 to 30 g / m. ² , More preferably 1-15m ² The 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.
[0039]
The image forming material in the present invention can be provided with a surface protective layer for the purpose of preventing adhesion of the image forming layer.
[0040]
The binder for the surface protective layer (uppermost layer) of the present invention may be any polymer, but the polymer having a carboxylic acid residue is 100 mg / m. ² More than 5g / m ² It is preferable to include the following. Examples of the polymer having a carboxyl residue are 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 content of the carboxy residue in such a polymer is preferably 10 mmol or more and 1.4 mol or less per 100 g of the polymer. 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. By using such a polymer, the polyvalent ions are prevented from becoming hydroxides and oxides and function effectively.
[0041]
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.
[0042]
For the image forming layer or the protective layer of the image forming layer in the present invention, it is possible to use a light absorbing material and a filter dye as described in U.S. Pat.Nos. 3,253,921, 2,274,782, 2,527,583 and 2,956,879. it can. 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, particularly preferably 0.2 to 1.5.
[0043]
The image forming layer of the image forming layer or emulsion layer in the present invention includes a polymer bead containing a matting agent such as starch, titanium dioxide, zinc oxide, silica, beads of the type described in US Pat. Nos. 2,992,101 and 2,701,245. Etc. can be contained. The emulsion surface may have any matte degree as long as no stardust failure occurs, but the Beck smoothness is preferably 200 seconds to 10,000 seconds, and more preferably 300 seconds to 10,000 seconds.
[0044]
The image forming material of the present invention has polyvalent metal ions on the surface having the image forming layer.
[0045]
The content of such polyvalent metal ions is 1 m ² It is preferably from 10 μmol to 1 mol, more preferably from 20 μmol to 100 mmol. Particularly preferably, it is 50 μmol or more and 100 mmol or less. When the content decreases, the present invention is not effective, and when the content increases, haze may increase.
[0046]
Of the present invention Polyvalent metal ion Is It is a polyvalent metal ion among metals selected from the elements of the transfer element [periodic tables 3 to 12 (groups of 3A to 7A, 8, 1B, 2B)] and periodic table 13 (3B), such as aluminum ( III), chromium (III), palladium (II), zirconium (II), zinc (II), manganese (II) and the like, and aluminum (III) and chromium (III) are preferably used. The polyvalent metal ion may be added by any method, but it is preferable to add a mineral acid or organic acid salt as an aqueous solution to the coating solution. Examples of such materials include sulfates such as aluminum sulfate and potassium chromium sulfate, acetates such as chromium acetate, nitrates such as palladium nitrate, and the like.
[0047]
Addition of polyvalent metal ions Layer Surface having image forming layer of support Except the image forming layer Any layer can be subtracted Layer, medium The intermediate layer, the protective layer, and the image forming material can be added by applying an aqueous solution of the polyvalent metal ion or immersing in an aqueous solution of the polyvalent metal ion before the image formation.
[0048]
The surface having the image forming layer of the image forming material of the present invention preferably has a film surface pH of 4.5 or less and 1.0 or more. The measurement method of membrane surface pH is 2cm ^Three Then, 300 μl of distilled water or ion-exchanged water is added dropwise to the solution, and the mixture is allowed to stand at 25 ° C. for 2 minutes. A more preferable value of the film surface pH is 4.3 or less and 3.0 or more.
[0049]
The pH of the film surface of the present invention can be adjusted by adding an acid or an alkali during the preparation of the image forming material. The acid used here may be any organic or inorganic acid, such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, sulfurous acid, carbonic acid, boric acid, perchloric acid, citric acid, acetic acid, propionic acid, p-toluenesulfonic acid, phthalic acid, Examples thereof include tetrachlorophthalic acid, benzoic acid, polymethacrylate, polyacrylate, polystyrene sulfonic acid and the like. The alkali may be either organic or inorganic, such as sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, ammonia, tetrabutylammonium hydroxide, triethylamine, N, N-diethyl Examples include aniline and 1,8-diazabicyclo [5.4.0] undecene. Further, a salt of a weak acid and a strong base or a salt of a strong acid and a weak base may be used, and examples thereof include sodium acetate, sodium hydrogen carbonate, potassium dihydrogen phosphate, and ammonium sulfate.
[0050]
Although the acid and alkali may be added in any way according to the present invention, it is preferably added to the image forming layer coating solution or the surface protective layer coating solution immediately before application of the image forming material, and an aqueous solution, an organic solvent solution, or a dispersion addition Any method may be used. The amount of acid and alkali added may be any amount that achieves the target membrane surface pH, but 1 mg / m ² 10g / m or more ² The following is preferred.
[0051]
The photosensitive heat-developable image forming material in the present invention contains photosensitive silver halide. Mu Methods for forming photosensitive silver halide are well known in the art, and for example, the methods described in Research Disclosure No. 17029 of June 1978 and US Pat. No. 3,700,458 can be used. . Specific methods that can be used in the present invention include a method in which a part of silver of an organic silver salt is converted into photosensitive silver halide by adding a halogen-containing compound to the prepared organic silver salt, gelatin Alternatively, a method of preparing photosensitive silver halide grains by adding a silver supply compound and a halogen supply compound to another polymer solution and mixing it with an organic silver salt can be used. In the present invention, the latter method can be preferably used. The grain size of the photosensitive silver halide is preferably small for the purpose of keeping the cloudiness after image formation low, specifically 0.20 μm or less, more preferably 0.01 μm or more and 0.15 μm or less, and still more preferably. It is preferably 0.02 μm or more and 0.12 μm or less. The grain size here means the length of the edge of the silver halide grain when the silver halide grain is a so-called normal crystal of a cube or octahedron. Further, when the silver halide grain is a tabular grain, it means a diameter when converted into a circular image having the same area as the projected area of the main surface. In the case of other non-normal crystals, for example, in the case of spherical grains, rod-shaped grains, etc., it means the diameter when considering a sphere equivalent to the volume of silver halide grains.
[0052]
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. There are no particular restrictions on the surface index (Miller index) of the outer surface of the photosensitive silver halide grains, but the {100} surface occupies a high proportion of spectral sensitization efficiency when the spectral sensitizing dye is adsorbed. preferable. The ratio is preferably 50% or more, more preferably 65% or more, and still more preferably 80% or more. The ratio of the Miller index {100} plane is T.Tani; J.Imaging Sci., 29, 165 (1985) using the adsorption dependence of {111} and {100} planes in the adsorption of sensitizing dyes. It can be determined by the method described. The halogen composition of the photosensitive silver halide is not particularly limited and may be any of silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver iodochlorobromide, and silver iodide. In the present invention, silver bromide or silver iodobromide can be preferably used. Particularly preferred is silver iodobromide, and the silver iodide content is preferably from 0.1 mol% to 40 mol%, more preferably from 0.1 mol% to 20 mol%. The distribution of the halogen composition in the grain may be uniform, the halogen composition may be changed stepwise, or may be continuously changed. High silver iodobromide grains can be used. In addition, silver halide grains preferably having a core / shell structure can be used. As the structure, core / shell particles having a preferably 2- to 5-fold structure, more preferably a 2- to 4-fold structure can be used.
[0053]
The photosensitive silver halide grain of the present invention preferably contains at least one metal complex selected from rhodium, rhenium, ruthenium, osnium, iridium, cobalt, mercury or iron. One kind of these metal complexes may be used, or two or more kinds of complexes of the same metal and different metals may be used in combination. The preferred content is in the range of 1 nmol to 10 mmol, and more preferably in the range of 10 nmol to 100 μmol, with respect to 1 mol of silver. As a specific metal complex structure, a metal complex having a structure described in JP-A-7-225449 can be used. For cobalt and iron compounds, hexacyano metal complexes can be preferably used. Specific examples include, but are not limited to, ferricyanate ions, ferrocyanate ions, hexacyanocobaltate ions, and the like. The content of the metal complex in the silver halide may be uniform, may be contained in the core part at a high concentration, or may be contained in the shell part at a high concentration, and is not particularly limited.
[0054]
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.
[0055]
The photosensitive silver halide grains in the present invention are preferably chemically sensitized. As a preferable chemical sensitization method, a sulfur sensitization method, a selenium sensitization method and a tellurium sensitization method can be used as is well known in the art. Further, noble metal sensitization methods such as gold compounds, platinum, palladium, iridium compounds and reduction sensitization methods can be used. As the compound preferably used in the sulfur sensitization method, selenium sensitization method and tellurium sensitization method, known compounds can be used, but compounds described in JP-A-7-128768 and the like can be used. 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. As the compound preferably used for the noble metal sensitization method, for example, chloroauric acid, potassium chloroaurate, potassium aurithiocyanate, gold sulfide, gold selenide, or compounds described in US Pat. No. 2,448,060, British Patent 618,061, etc. are preferable. 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.
[0056]
The amount of the photosensitive silver halide of the present invention is preferably 0.01 to 0.5 mol, more preferably 0.02 to 0.3 mol, more preferably 0.03 to 0.25 mol, per mol of the organic silver salt. The following are particularly preferred: Regarding the mixing method and mixing conditions of photosensitive silver halide and organic silver salt prepared separately, the silver halide grains and organic silver salt that have been prepared respectively are 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. There is no particular limitation as long as it appears.
[0057]
As the silver halide preparation method of the present invention, a so-called hydration method in which a part of silver of the organic silver salt is halogenated with an organic or inorganic halide is also preferably used. Any organic halide may be used as long as it is a compound that reacts with an organic silver salt to produce silver halide, but N-halogenoimide (N-bromosuccinimide, etc.), halogenated quaternary nitrogen compound (odor) And tetrabutylammonium bromide) and halogenated quaternary nitrogen salts and halogen molecule aggregates (pyridinium perbromide). The inorganic halogen compound may be any compound as long as it is a compound that reacts with an organic silver salt to produce silver halide, but alkali metal halide or ammonium (sodium chloride, lithium bromide, potassium iodide, ammonium bromide, etc. ), Alkaline earth metal halides (calcium bromide, magnesium chloride, etc.), transition metal halides (ferric chloride, cupric bromide, etc.), metal complexes with halogen ligands (sodium iridate bromide) , Ammonium chloride rhodate), and halogen molecules (bromine, chlorine, iodine). Moreover, you may use desired organic inorganic halide together.
[0058]
In the present invention, the amount of halide added during the halide is preferably 1 to 500 mmol, more preferably 10 to 250 mmol, as a halogen atom per mol of the organic silver salt.
[0059]
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.
[0060]
As an example of spectral sensitization to red light, a so-called red light source such as a He-Ne laser, a red semiconductor laser, or an LED is disclosed in I-1 to I-38 described in JP-A-54-18726. Compounds, compounds of I-1 to I-35 described in JP-A-6-75322, compounds of I-1 to I-34 described in JP-A-7-287338, and dyes described in JP-B-55-39818 From 1 to 20, compounds of I-1 to I-37 described in JP-A-62-284343 and compounds of I-1 to I-34 described in JP-A-7-287338 are advantageously selected.
[0061]
For semiconductor laser light sources in the 750-1400 nm wavelength range, various known dyes including cyanine, merocyanine, styryl, hemicyanine, oxonol, hemioxonol and xanthene dyes can be spectrally sensitized. it can. Useful cyanine dyes are, for example, cyanine dyes having basic nuclei such as thiazoline nucleus, oxazoline nucleus, pyrroline nucleus, pyridine nucleus, oxazole nucleus, thiazole nucleus, selenazole nucleus and imidazole nucleus. Useful merocyanine dyes are preferably acidic nuclei such as thiohydantoin nucleus, rhodanine nucleus, oxazolidinedione nucleus, thiazolinedione nucleus, barbituric acid nucleus, thiazolinone nucleus, malononitrile nucleus and pyrazolone nucleus in addition to the above basic nucleus. Including. Of the above-mentioned cyanine and merocyanine dyes, those having an imino group or a carboxyl group are particularly effective. For example, U.S. Pat.Nos. -194781 and 6-301141 may be appropriately selected from known dyes.
[0062]
Particularly preferred as the structure of the dye used in the present invention is a cyanine dye having a thioether bond-containing substituent (for example, JP-A Nos. 62-58239, 3-138638, 3-138642, and 4- No. 255840, No. 5-72659, No. 5-72661, No. 6-222491, No. 2-230506, No. 6-258757, No. 6-317868, No. 6-324425, and No. 7- 500926, a dye described in US Pat. No. 5,541,054), a dye having a carboxylic acid group (for example, dyes described in JP-A Nos. 3-163440 and 6-301141, US Pat. No. 5,441,899), a merocyanine dye, Multinuclear merocyanine dyes and polynuclear cyanine dyes (JP-A-47-6329, 49-105524, 51-127719, 52-80829, 54-61517, 59-214846, 60-6750) No. 63-159841, JP-A-6-35109, JP-A-6-59381, JP-A-7-65537, JP-A-7-65537, JP-T 55-50111, British Patent 1,467,638, US Patent 5,281,515 Dyes described in 1)
[0063]
Further, as dyes forming J-band, U.S. Pat.Nos. 5,510,236 and 3,871,887 described in Example 5, JP-A-2-96131 and JP-A-59-48753 are disclosed, which are preferable in the present invention. Can be used.
[0064]
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 that exhibit supersensitization, and substances that exhibit supersensitization are listed in Research Disclosure 176, 17643 (issued in December 1978), page 23, Section IV, or Japanese Examined Patent Publication 49-25500 No. 43-4933, JP-A-59-19032, 59-192242 and the like.
[0065]
Two or more sensitizing dyes used in the present invention may be used in combination. 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.
[0066]
Further, as disclosed in US Pat. No. 3,469,987, etc., the 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. Was dissolved, the solution can also be used a method of adding to the emulsion. In addition, ultrasonic waves can be used for dissolution.
[0067]
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. Or / and the time before desalting, during the desilvering step and / or after desalting to before the start of chemical ripening, as disclosed in the specification of JP-A-58-113920, etc. The emulsion may be added at any time just before or during the process, after chemical ripening and before the emulsion is coated before the coating. 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.
[0068]
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 ^-1 Mole is more preferred.
[0069]
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 thiazonium salts described in U.S. Pat.Nos. 2,131,038 and 2,694,716, azaindenes described in U.S. Pat.Nos. 2,886,437 and 2,444,605. Mercury salts described in U.S. Pat.No. 2,728,663, urazole described in U.S. Pat.No. 3,287,135, sulfocatechol described in U.S. Pat.No. 3,235,652, oxime described in U.K. Polyvalent metal salts, thiuronium salts described in U.S. Pat.No. 3,220,839, and palladium, platinum and gold salts described in U.S. Pat. The triazines described in U.S. Pat.Nos. 4,128,557 and 4,137,079, 4,138,365 and 4,459,350 And phosphorus compounds described in US Pat. No. 4,411,985.
[0070]
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, US Examples thereof include compounds disclosed in Patents 5340712, 5369000, and 5464737.
[0071]
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, vibrating ball mill, sand mill, colloid mill, jet mill, roller mill, etc.). A dispersion aid may be used when dispersing the solid fine particles.
[0072]
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 in the range of 1 nmol to 1 mmol, more preferably 10 nmol to 100 μmol, per mol of applied silver.
[0073]
The photosensitive heat-developable image forming material in the present invention may contain benzoic acids for the purpose of increasing sensitivity and preventing fogging. The benzoic acid of the present invention may be any benzoic acid derivative. Examples of preferred structures include U.S. Pat. Nos. 4,784,939, 4,152,160, Japanese Patent Application Nos. 8-151422, 8-151411, and 8-98051. And the compounds described in. The benzoic acids of the present invention may be added to any part of the image forming material. However, the additive layer is preferably added to the layer having the photosensitive layer as the image forming layer, and is added to the organic silver salt-containing layer. More preferably, it is added. The benzoic acid of the present invention may be added at any step of preparing the coating solution, and when added to the organic silver salt-containing layer, any step from the preparation of the organic silver salt to the preparation of the coating solution may be used. It is preferable that the salt is prepared and immediately before coating. As a method for adding the benzoic acid of the present invention, any method such as powder, solution, fine particle dispersion and the like may be used. Moreover, you may add as a solution mixed with other additives, such as a sensitizing dye, a reducing agent, and a color toning agent. The addition amount of the benzoic acid of the present invention may be any amount, but it is preferably 1 μmol or more and 2 mol or less, more preferably 1 mmol or more and 0.5 mol or less per 1 mol of silver.
[0074]
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. .
[0075]
When a mercapto compound is used in the present invention, any structure may be used, but those represented by Ar-SM and Ar-SS-Ar are preferred. In the formula, M is a hydrogen atom or an alkali metal atom, and Ar is an aromatic ring group or a condensed aromatic ring group having one or more nitrogen, sulfur, oxygen, selenium or tellurium atoms. Preferably, the heteroaromatic ring in these groups is benzimidazole, naphthimidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotelrazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, triazine , Pyrimidine, pyridazine, pyrazine, pyridine, purine, quinoline or quinazolinone. The heteroaromatic ring can be, for example, halogen (eg, Br and Cl), hydroxy, amino, carboxy, alkyl (eg, having one or more carbon atoms, preferably 1 to 4 carbon atoms) and alkoxy ( For example, it may have one selected from the substituent group consisting of one or more carbon atoms, preferably one having 1 to 4 carbon atoms. Mercapto-substituted heteroaromatic compounds include 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-methylbenzimidazole, 6-ethoxy-2-mercaptobenzothiazole, 2, 2'-dithiobis-benzothiazole, 3-mercapto-1,2,4-triazole, 4,5-diphenyl-2-imidazolethiol, 2-mercaptoimidazole, 1-ethyl-2-mercaptobenzimidazole, 2-mercaptoquinoline , 8-mercaptopurine, 2-mercapto-4 (3H) -quinazolinone, 7-trifluoromethyl-4-quinolinethiol, 2,3,5,6-tetrachloro-4-pyridinethiol, 4-amino-6- Hydroxy-2-mercaptopyrimidine monohydrate, 2-amino-5-mercapto-1,3,4-thiadiazole, 3-amino-5-mercapto-1,2,4-triazole, 4-hydrido Ci-2-mercaptopyrimidine, 2-mercaptopyrimidine, 4,6-diamino-2-mercaptopyrimidine, 2-mercapto-4-methylpyrimidine hydrochloride, 3-mercapto-5-phenyl-1,2,4-triazole, Examples include 2-mercapto-4-phenyloxazole, but the present invention is not limited to these.
[0076]
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 as the image forming layer, and more preferably 0.01 to 0.3 mol per mol of silver.
[0077]
In the image-forming layer of the present invention, a polyhydric alcohol (for example, glycerol and diol of the kind described in US Pat. No. 2,960,404), a fatty acid or an ester described in US Pat. Nos. 2,588,765 and 3,121,060 are used as a plasticizer and a lubricant. The silicone resin described in British Patent 955,061 can be used.
[0078]
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, 8-148 No. 156378, No. 8-148111, No. 8-148116, or a compound having a quaternary nitrogen atom described in Japanese Patent Application No. 8-83566 and acrylonitrile described in US Pat. No. 5,545,515 Compounds can be used. Specific examples of the compound include compounds 1 to 10 of the aforementioned U.S. 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, and 8-130842. H-1 to H-62, 1-18-121 of 8-148113, 1-50 of 8-148111, 1-40 of 8-148116, 8-83566 P-1 to P-26, T-1 to T-18, CN-1 to CN-13 of US Pat. No. 5,545,515, and the like.
[0079]
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, described in 5,545,507 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. Hei 8-32836. -Mu salts, specifically, A-1 to A-42, B-1 to B-27, C-1 to C-14, and the like can be used.
[0080]
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.
[0081]
The heat-developable photographic emulsion used for the photosensitive heat-developable forming material which is one embodiment of the present invention is contained in 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 contain an organic silver salt and silver halide in the first emulsion layer (usually the layer adjacent to the support) and some other ingredients 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 may include all components in a single layer as described in US Pat. No. 4,708,928. Good. In the case of multi-dye multi-color photothermographic materials, each emulsion layer is generally functional or non-functional between each emulsion layer (photosensitive layer) as described in US Pat. No. 4,460,681. By using barrier layers, they are kept distinct from each other.
[0082]
In the photosensitive layer of the photosensitive heat-developable image forming material of the present invention, various dyes and pigments can be used from the viewpoint of improving the color tone and preventing irradiation. Any dyes and pigments may be used for the photosensitive layer of the present invention, for example, there are pigments and dyes described in the color index, specifically pyrazoloazole dyes, anthraquinone dyes, azo dyes, azomethine dyes, oxonol dyes, Examples thereof include carbocyanine dyes, styryl dyes, triphenylmethane dyes, indoaniline dyes, indophenol dyes, organic pigments such as phthalocyanine, and inorganic pigments. Preferred dyes used in the present invention include anthraquinone dyes (for example, compounds 1 to 9 described in JP-A-5-341441, compounds 3-6 to 18 and 3-23 to 38 described in JP-A-5-165147), azomethine Dyes (such as compounds 17 to 47 described in JP-A-5-341441), indoaniline dyes (for example, compounds 11 to 19 described in JP-A-5-289227, compound 47 described in JP-A-5-341441, JP-A-5-341) And compounds 2-10 to 11 described in JP-A No. 165147) and azo dyes (compounds 10 to 16 described in JP-A-5-341441). As a method for adding these dyes, 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 desired amount of absorption, but generally 1m ² It is preferably used in the range of 1 μg or more and 1 g or less.
[0083]
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 a 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 0.3 or less.
[0084]
When antihalation dyes are used in the present invention, such dyes have the desired absorption in the wavelength range, and have a sufficiently low absorption in the visible region after processing, so that any desired absorbance spectrum shape of the antihalation layer can be obtained. 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, left lower column to page 16, right lower column, there are compounds described in Japanese Patent Application Laid-Open No. 52- 139136, 53-132334, 56-501480, 57-16060, 57-68831, 57-101835, 59-182436, JP-A-7-36145, 7-199409 No. 48, No. 48-33692, No. 50-16648, No. 2-41734, No. 4,088,497, No. 4,283,487, No. 4,548,896, No. 5,187,049.
[0085]
The image forming material of the present invention has an image forming layer such as a photosensitive layer containing at least one silver halide emulsion on one side of a support and a back layer (backing layer) on the other side. A so-called single-sided image forming material is preferable.
[0086]
In the present invention, a matting agent may be added to improve 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, the 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., 1,260,772 No. 2,192,241, No. 3,257,206, No. 3,370,951, No. 3,523,022, No. 3,769,020, and other inorganic matting agents well known in the art 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. There are no particular limitations on the size and shape of the matting agent, and those having an arbitrary particle size can be used. In the practice of the present invention, it is preferable to use one having a particle size of 0.1 μm to 30 μm. 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 coating film, the particle size, shape, and particle size distribution can be brought into a state as needed during preparation of the matting agent or by mixing a plurality of matting agents. preferable.
[0087]
In the present invention, the matte degree of the back layer is preferably Beck smoothness of 250 seconds or less and 10 seconds or more, more preferably 180 seconds or less and 50 seconds or more.
[0088]
In the present invention, the matting agent is preferably contained in the outermost surface layer of the image forming material, the layer functioning as the outermost surface layer, or a layer close to the outer surface, and also contained in a layer acting as a so-called protective layer. Is preferred.
[0089]
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), poly (vinyl butyral)), poly (esters), poly (urethane ), Phenoxy resin, poly ( Vinylidene chloride), poly (epoxides), poly (carbonates), poly (vinyl acetate), cellulose esters, poly (amides). The binder may be formed from water, an organic solvent or an emulsion.
[0090]
In the present invention, the back layer of the photosensitive heat-developable image forming material preferably has a maximum absorption in the exposure wavelength range of 0.2 or more, more preferably 0.3 or more and 2.0 or less, particularly preferably 0.5 or more and 2.0 or less. Absorption is preferably reduced to 0.1 or less under heat development image forming conditions.
As dyes to be decolored by treatment, JP-A-52-139136, 53-132334, 56-501480, 57-16060, 57-68831, 57-101835, 59-182436 JP, 7-36145, JP 7-199409, JP-B 48-33692, JP 50-16648, JP-B 2-41734, U.S. Patents 4,088,497, 4,283,487, 4,548,896, 5,187,049 There is a number. In particular, a combination of a decoloring dye and a decoloring agent described in Japanese Patent Application No. 8-304012 is preferably used for the heat decoloring layer.
[0091]
Backside resistive heating layers such as those shown in U.S. Pat. Nos. 4,460,681 and 4,374,921 can also be used in photosensitive photothermographic image systems.
[0092]
A hardener may be used in each layer such as the image forming layer, protective layer, and back layer of the present invention. Examples of hardeners include polyisocyanates described in US Pat. No. 4,281,060, JP-A-6-208193, epoxy compounds described in US Pat. No. 4,791,042, and JP-A 62-89048. The vinyl sulfone compounds described in the above are used.
[0093]
In the present invention, a surfactant may be used for the purpose of improving coating properties 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.
[0094]
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.
[0095]
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.
[0096]
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, especially baryta paper, and partially acetylated α-olefin polymers, especially polymers with 2-10 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.
[0097]
The imaging material of the present invention may comprise an antistatic or conductive layer, such as a soluble salt (eg, 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 US You may have a layer containing the insoluble inorganic salt etc. as described in patent 3,428,451.
[0098]
As a method for obtaining a color image using the photosensitive heat-developable image forming material in the present invention, there is a method described in JP-A-7-13295, page 10, left column, line 43 to 11, left column, line 40. Color dye image stabilizers are exemplified in British Patent 1,326,889, US Patent 3,432,300, 3,698,909, 3,574,627, 3,573,050, 3,764,337 and 4,042,394.
[0099]
The photothermographic emulsion in the present invention can be coated by various coating operations including dip coating, air knife coating, flow coating or extrusion coating using a hopper of the type described in US Pat. No. 2,681,294. If desired, two or more layers can be coated simultaneously by the methods described in US Pat. No. 2,761,791 and British Patent 837,095.
[0100]
Additional layers in the imaging material of the present invention, such as dye receiving layers for receiving mobile dye images, opacifying layers when reflective printing is desired, protective topcoat layers and primer layers known in the photothermographic art Etc. can be included. The image forming material of the present invention can preferably form an image with only one material, and it is preferable that a functional layer necessary for image formation such as an image receiving layer does not become another material.
[0101]
The image forming material of the present invention may be developed by any method, but is usually developed by raising the temperature of the photosensitive material exposed imagewise. The preferred development temperature is 80 to 250 ° C, more preferably 100 to 140 ° C. The development time is preferably 1 to 180 seconds, and more preferably 10 to 90 seconds.
[0102]
The photosensitive heat-developable image forming material of the present invention may be exposed by any method, but a laser beam is preferable as an exposure light source. As the laser beam according to the present invention, a gas laser, a YAG laser, a dye laser, a semiconductor laser and the like are preferable. A semiconductor laser and a second harmonic generation element can also be used.
[0103]
The photosensitive heat-developable image forming material of the present invention has a low haze at the time of exposure and tends to generate interference fringes. As this interference fringe generation prevention technology, there is a technology for obliquely entering a laser beam disclosed in Japanese Patent Laid-Open No. 5-11548 etc. with respect to an image forming material, a multimode disclosed in WO95 / 31754, etc. Known to use lasers
These techniques are preferably used.
[0104]
To expose the photosensitive heat-developable image forming material of the present invention, laser light as disclosed in SPIE vol. 169 Laser Printing, pages 116-128 (1979), JP-A-4-51043, WO95 / 31754, etc. Are preferably exposed so that the scanning lines are not visible.
[0105]
【Example】
The effect of this invention is demonstrated with an Example below.
[0106]
Example 1
<< Preparation of silver halide grains >>
Dissolve 22 g of phthalated gelatin and 30 mg of potassium bromide in 700 ml of water, adjust the pH to 5.0 at a temperature of 35 ° C., and then add 159 ml of an aqueous solution containing 18.6 g of silver nitrate and 0.9 g of ammonium nitrate and 92 ml of potassium bromide and potassium iodide. An aqueous solution containing a molar ratio of: 8 was added over 10 minutes by the control double jet method while maintaining pAg of 7.7. Next, 476 ml of an aqueous solution containing 55.4 g of silver nitrate and 2 g of ammonium nitrate and an aqueous solution pAg7.7 containing 10 μmol / liter of dipotassium hexachloroiridate and 1 mol / liter of potassium bromide for 30 minutes by the control double jet method. After that, 1 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added, and the pH was further lowered to cause aggregation and sedimentation, followed by desalting. Thereafter, 0.1 g of phenoxyethanol was added to adjust the pH to 5.9, pAg 8.2, and silver iodobromide grains (iodine content core 8 mol%, average 2 mol%, average size 0.05 μm, projected area variation coefficient 8%, (100 ) Preparation of cubic particles having a surface ratio of 88%.
[0107]
The silver halide grains thus obtained were heated to 60 ° C. and 85 μmol of sodium thiosulfate and 11 μmol, 15 μmol of 2,3,4,5,6-pentafluorophenyldiphenylphosphine selenide per mol of silver. Tellurium compound, 1 μmol of chloroauric acid, 270 μmol of thiocyanic acid, ripen for 120 minutes, rapidly cool to 40 ° C., add 100 μmol of dye, 500 μmol of 2-mercapto-5-methylbenzimidazole A silver halide emulsion was obtained by rapid cooling to 0 ° C.
[0108]
<< Preparation of organic acid silver dispersion >>
Stirric acid 4g, arachidic acid 6g, behenic acid 36g, distilled water 850ml with vigorous stirring at 90 ° C, 1N-NaOH aqueous solution 187ml was added and reacted for 120 minutes, 1N-nitric acid 65ml was added and then the temperature was lowered to 50 ° C . Next, 125 ml of an aqueous solution of 21 g of silver nitrate was added over 100 seconds while stirring more vigorously, and left as it was for 20 minutes. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the filtrate had a conductivity of 30 μS / cm. 100 g of a 10 wt% hydroxypropylmethylcellulose aqueous solution was added to the solid content thus obtained, and water was further added to a total weight of 270 g, followed by rough dispersion in an automatic mortar to obtain a crude organic acid silver dispersion. This organic acid silver crude dispersion was subjected to a collision of 1000 kg / cm using a nanomizer (manufactured by Nanomizer). ^Three To obtain an organic acid silver dispersion. The organic acid silver particles contained in the organic acid silver dispersion thus obtained were needle-like particles having an average minor axis of 0.04 μm, an average major axis of 0.8 μm, and a coefficient of variation of 30%.
[0109]
<< Preparation of reducing agent dispersion >>
To 100 g of 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane and 50 g of hydroxypropylcellulose, 850 g of water was added and mixed well to obtain a slurry. 840 g of zirconia beads having an average diameter of 0.5 mm were prepared, put into a vessel together with the slurry, and dispersed for 5 hours with a disperser (1/4 G sand grinder mill: manufactured by IMEX Co., Ltd.) to obtain a reducing agent dispersion.
[0110]
<< Preparation of organic polyhalide dispersion >>
940 g of water was added to 50 g of tribromomethylphenylsulfone and 10 g of hydroxypropylmethylcellulose and mixed well to prepare a slurry. 840 g of zirconia beads having an average diameter of 0.5 mm were prepared, placed in a vessel together with the slurry, and dispersed for 5 hours with a disperser (1/4 G sand grinder mill: manufactured by IMEX Co., Ltd.) to obtain an organic polyhalide dispersion. .
[0111]
<Preparation of emulsion layer coating solution>
100 g organic acid dispersion obtained above, 20 g reducing agent dispersion, 15 g organic polyhalide dispersion, LACSTAR 3307B (manufactured by Dainippon Ink & Chemicals, Inc .; SBR latex), silver halide Emulsion layer coating solution was prepared by thoroughly mixing 20 g of emulsion and 100 g of water. The Luck Star 3307B is a latex of a styrene-butadiene copolymer having an equilibrium water content of 0.6 wt%, and the average particle size of dispersed particles in the latex is about 0.1 to 0.15 μm.
[0112]
<Preparation of emulsion surface protective layer coating solution>
270 mg of N-perfluorooctylsulfonyl-N-propylalanine potassium salt, 100 mg of sodium dodecylbenzenesulfonate, 9 g of polymethyl methacrylate fine particles (average particle size 2.5 μm), phthalazine 350 mg, 4-methylphthalic acid to 100 g of inert gelatin A sulfuric acid in an amount of 600 mg and a pH of the membrane surface of 4.0 and a salt of polyvalent metal ions in an amount shown in Table 1 were added, and water was added to a total amount of 160 ml to obtain a surface protective layer coating solution.
[0113]
<Back layer coating solution>
Solid base N, N, N ″, N ″ -tetraethylguanidine and 4-carboxysulfonyl-phenylsulfone molar ratio 10g salt 10g polyvinyl alcohol 10g, water 88g and 1 / 16G sand grinder mill ( Dispersed with Imex Co., Ltd. to obtain a base solution
.
[0114]
An organic solvent phase in which 2.1 g of basic dye precursor, 7.9 g of acidic substance, 0.1 g of dye and 10 g of ethyl acetate are mixed and dissolved is mixed in an aqueous phase consisting of 10 g of polyvinyl alcohol and 80 g of water, and emulsified and dispersed at room temperature. (Average particle size 2.5 μm) was obtained.
[0115]
39 g of base solution thus obtained, 26 g of dye solution, 36 g of polyvinyl alcohol 10 wt% aqueous solution
A back surface coating solution was obtained by mixing.
[0116]
<Back surface protective layer coating solution>
Gelatin 20g, polymethylmethacrylate (average particle size 7μm) 0.6g, sodium dodecylbenzenesulfonate 0.4g, X-22-2809 (Shin-Etsu Silicone Co., Ltd. silicone compound) 1g was dissolved in 480g of water and a back surface protective layer was applied. A liquid was obtained.
[0117]
<< Preparation of photosensitive heat-developable image forming material (photosensitive material) >>
SBR and gelatin-coated 175 μm polyethylene terephthalate support with back layer coating solution in an amount such that the optical density at 647 nm is 0.7 and back surface protective layer coating solution at 50 g / m ² After simultaneous multi-layer coating, emulsion layer coating solution is coated on the opposite side of the back surface. ² Emulsion surface protective layer coating solution, gelatin amount 1.5g / m ² It applied so that it might become. The smoothness of the light-sensitive material thus obtained (the Beck smoothness was investigated using the Oken type smoothness measurement described in J. TAPPI paper pulp test method No. 5) was 1000 seconds for the emulsion surface and 80 seconds for the back surface. .
[0118]
In addition, the structural formula of the compound used in the above is as follows.
[0119]
[Chemical 1]

[0120]
(Evaluation of photographic performance)
After exposing the photosensitive material at an inclination of 30 degrees with respect to the normal line with a 647 nm Kr laser sensitometer (maximum output 500 mW), the photosensitive material is processed (developed) at 125 ° C. for 15 seconds, and the resulting image is evaluated for density The total was done. The measurement results were evaluated by Dmin (fogging) and sensitivity (the reciprocal of the ratio of exposure amount giving a density 1.0 higher than Dmin). Regarding the sensitivity, the sensitivity of the photosensitive material 1-1 was set to 100.
[0121]
In addition, the image color tone of the region where the density was 1 was visually evaluated according to the following criteria.
[0122]
◎ ・ ・ ・ Cool black tone.
○ ・ ・ ・ It is slightly warm, but I don't mind.
Δ: Warm tone but practically acceptable.
X: Remarkably warm, not possible.
[0123]
(Evaluation of forced storage over time)
Each photosensitive material is cut into 30.5cm x 25.4cm, rounded corners with an inner diameter of 0.5cm, left at 25 ° C-50% RH for one day, and 10 photosensitive materials each in a bag made of moisture-proof material The product was sealed in a box, and further placed in a 35.1 cm × 26.9 cm × 3.0 cm cosmetic box and aged for 5 days at 50 ° C. (forced aging). Development was performed in the same manner as the photographic performance of the light-sensitive material thus obtained, and Dmin was evaluated.
[0124]
Table 1 shows the results of the above evaluation for each photosensitive material.
[0125]
[Table 1]

[0126]
From Table 1, it can be seen that the sensitivity, Dmin, color tone, and forced storage stability are excellent in the region of the present invention. Further, the above photosensitive material was stored for 3 days under the conditions of 10,000 lx and 40 ° C.-60% RH, and the optical image storage stability was examined. As a result, the photosensitive material 1-1 had a Dmin density of 0.70. In contrast, the photosensitive materials 1-2 to 9 were 0.15 or less, and it was found that the optical image storage stability was excellent.
[0127]
Example 2
In the photosensitive material 1-3 of Example 1, the emulsion surface protective layer gelatin was replaced with polymethacrylate, polymethacrylate / polybutylacrylate copolymer, and carboxymethylcellulose. Good performance equivalent to that of the photosensitive material 1-3 was obtained except that the values were 3%, 8%, and 10% lower than 3, respectively.
[0128]
Comparative Example 1
When 4-methylphthalic acid was removed from the light-sensitive material 1-3 of Example 1, no image was obtained.
[0129]
Example 3
In the photosensitive material 1-3 of Example 1, when 4-methylphthalic acid was replaced with an equimolar amount of phthalic acid, the sensitivity was as good as the photosensitive material 1-3 except that the sensitivity was 5% lower than that of the photosensitive material 1-3. Performance was obtained.
[0130]
reference Example 4
In the photosensitive material 1-3 of Example 1, when aluminum sulfate was not added to the emulsion surface protective layer and the same amount of aluminum sulfate was added to the image forming layer, the sensitivity was 7% lower than that of the photosensitive material 1-3. Good performance equivalent to that of the photosensitive material 1-3 was obtained except that the fog in storage stability with time was 0.10.
[0131]
Example 5
The coating amount of N- (2-methoxyphenyl) -N′-formylhydrazine was 1 mg / m in the emulsion layer coating solutions of the light-sensitive materials 1-1 and 1-3 of Example 1. ² Photosensitive materials 2-1 and 2-2 were prepared by adding so that
[0132]
The photosensitive material thus obtained was exposed to x and 0.5 as the exposure amount at which the density was 2.5 when a square with an inclination of 30 degrees with respect to the normal and a 1 cm side was exposed with a 647 nm Kr laser sensitometer (maximum output 500 mW). Except that the exposure amount is set to the exposure amount y, the exposure is performed alternately with the exposure amount x and the exposure amount y so that the long side of the rectangle with a short side of 100 μm and a long side of 1 cm touches, and the development temperature is set to 115 ° C. Photosensitive material 2-1 (comparative example) was visually evaluated according to the following criteria after standing for 1 month at 40 ° C under light-shielded conditions processed in the same manner as in photographic evaluation in Example 1. X, Photosensitive material 2-2 (invention) is ◎, and it was found that the image storage stability was excellent in the region of the invention.
[0133]
◎ ・ ・ ・ There is almost no change.
○ The image part is slightly enlarged, but I don't care.
Δ: The image portion is enlarged by 5 μm or more, but is practically acceptable.
×: Not possible because the image area is enlarged by 20 μm or more.
[0134]
The photographic material 2-2 of the present invention was evaluated in terms of photographic performance and forced storage stability according to Example 1, and was found to be good. Moreover, γ was high and the tonality was sufficient.
[0135]
Example 6
In Example 1, silver halide in the emulsion layer coating solution was not added, but equimolar methyl 3,4-dihydroxybenzoate was added as an aqueous solution instead of the reducing agent dispersion, and the protective layer for the image forming layer contained a large amount. A heat-sensitive image forming material (heat-sensitive material) was obtained by adding no salt of a valent metal ion and further adding no base solution or dye solution on the back surface. As shown in Table 2, a salt of polyvalent metal ions was added to the image forming layer. Table 2 shows the concentration when the heat-sensitive material thus obtained was heated at 95 ° C. for 4 seconds and the concentration at the time of heating at 95 ° C. for 4 seconds after the same forced aging storage as in Example 1.
[0136]
In addition, the image color tone with heating at a density of 1 was visually evaluated according to the criteria of Example 1.
[0137]
The results are shown in Table 2.
[0138]
[Table 2]

[0139]
From Table 2, it can be seen that the region of the present invention has a high density and a cool black tone, and is excellent in storage stability.
[0140]
【The invention's effect】
According to the present invention, it is possible to obtain an image forming material having good sensitivity, fogging, image color tone and excellent storage stability.

Claims (19)

One side of the support has an image forming layer containing an organic silver salt, a photosensitive silver halide and a reducing agent, and any layer on the side of the support having the image forming layer (excluding the image forming layer) In addition, a polyvalent metal ion of a metal selected from each group of the periodic tables 3 to 12 (3A to 7A, 8, 1B, 2B) and an element of the periodic table 13 (3B) group, phthalic acid, and 4-methylphthalic acid An image-forming material comprising a photosensitive heat-developable image-forming material having a compound selected from 4-nitrophthalic acid, tetrachlorophthalic anhydride, 2,3-dicarboxynaphthalene, and metal salts thereof. A compound selected from the polyvalent metal ion and the phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, tetrachlorophthalic anhydride, 2,3-dicarboxynaphthalene and a metal salt thereof is an undercoat layer, an intermediate layer The image forming material according to claim 1, wherein the image forming material is contained in a layer, a protective layer, or an overcoat layer. A compound selected from the polyvalent metal ions and the phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, tetrachlorophthalic anhydride, 2,3-dicarboxynaphthalene, and metal salts thereof is a protective layer or an overcoat. The image forming material according to claim 1, wherein the image forming material is contained in a layer. The multivalent metal ion is aluminum (III), chromium (III), palladium (II), zirconium (II), zinc (II) or manganese (II), 2. The image forming material according to item 1. The image forming material according to claim 1, wherein the polyvalent metal ion is a mineral acid or an organic acid salt added as an aqueous solution to the coating solution. The image forming material according to claim 1, wherein the polyvalent metal ion is sulfate, acetate, or nitrate. The image forming material according to claim 1, wherein the content of the polyvalent metal ion is 10 μmol or more and 1 mol or less per 1 m ² . The image forming material according to claim 1, wherein a film surface pH of the surface having the image forming layer is 4.5 or less and 1.0 or more. The carboxylic acid residue-containing polymer of 100 mg / m ² or more and 5 g / m ² or less is provided on the uppermost layer of the surface having the image forming layer of the support, according to any one of claims 1 to 8. Imaging material. The image forming material according to claim 1, wherein the image forming material forms a silver image. And an image forming layer containing organic silver salt Contact and reducing agent on one surface of the support, any layer of the surface having the image forming layer of the support (excluding the image-forming layer), the periodic table 3 To 12 (3A to 7A, 8, 1B, 2B) and polyvalent metal ions of metals selected from the elements of Group 13 (3B) of the periodic table, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid An image-forming material, which is a heat-sensitive image-forming material having a compound selected from tetrachlorophthalic anhydride, 2,3-dicarboxynaphthalene, and metal salts thereof. A compound selected from the polyvalent metal ion and the phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, tetrachlorophthalic anhydride, 2,3-dicarboxynaphthalene and a metal salt thereof is an undercoat layer, an intermediate layer The image forming material according to claim 11, wherein the image forming material is contained in a layer, a protective layer, or an overcoat layer. A compound selected from the polyvalent metal ions and the phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, tetrachlorophthalic anhydride, 2,3-dicarboxynaphthalene, and metal salts thereof is a protective layer or an overcoat. The image forming material according to claim 11, wherein the image forming material is contained in a layer. The multivalent metal ion is aluminum (III), chromium (III), palladium (II), zirconium (II), zinc (II) or manganese (II), 2. The image forming material according to item 1. The image forming material according to claim 11, wherein the polyvalent metal ion is a mineral acid or an organic acid salt added as an aqueous solution to the coating solution. The image forming material according to claim 11, wherein the polyvalent metal ion is sulfate, acetate, or nitrate. 17. The image forming material according to claim 11, wherein the content of the polyvalent metal ions is 10 μmol or more and 1 mol or less per 1 m ² . The image forming material according to claim 11, wherein a film surface pH of the surface having the image forming layer is 4.5 or less and 1.0 or more. The image forming material according to claim 11, wherein the image forming material forms a silver image.