JP3715394B2 - Photothermographic material - Google Patents

Description

【０１１４】
【化２】

【０１１５】
（有機酸銀微結晶分散物の調製）
ベヘン酸40ｇ、ステアリン酸7.3ｇ、水500mlを温度90℃で15分間攪拌し、1NーNaOH187mlを15分間かけて添加し、1Nの硝酸水溶液61mlを添加して50℃に降温した。次に1N硝酸銀水溶液124mlを2分間かけて添加し、そのまま30分間攪拌した。その後、吸引濾過で固形分を濾別し、濾水の伝導度30μS／cmになるまで固形分を水洗した。こうして得られた固形分は、乾燥させないでウエットケーキとして取り扱い、乾燥固形分34.8ｇ相当のウエットケーキに対し、ポリビニルアルコール12ｇおよび水150ml添加し、良く混合してスラリーとした。平均直径0.5mmのジルコニアビーズを840ｇ用意してスラリーと一緒にベッセルに入れ、分散機（1／4Ｇサンドグラインダーミル：アイメックス（株）製）にて5時間分散し、電子顕微鏡観察により平均短径0.04μｍ，平均長径0.8μｍ，投影面積変動係数30％の針状粒子である有機酸銀の微結晶分散物の調製を終了した。
【０１１６】
（還元剤固体微粒子分散物1、2の調製）
下記還元剤1、2それぞれ10gに対してヒドロキシプロピルセルロース4ｇと水86g添加して良く攪拌してスラリーとして10時間放置した。その後、平均直径0.5mmのジルコニア製ビーズを168g用意し、スラリーと一緒にベッセルに入れ、有機酸銀微結晶分散物の調製に用いたものと同じ分散機で10時間分散して還元剤1、2に対し固体微粒子分散液1、2を得た。粒子径は70wt％が1.0μｍ以下0.4μm 以上であった。
【０１１７】
【化３】

【０１１８】
（還元剤固体微粒子分散物3、4の調製）
上記還元剤1、2それぞれ4.5gを酢酸エチルに添加して攪拌溶解し、ポリビニルアルコール1.6gを水に溶解した溶液を添加してホモジナイザーにて高速攪拌した。その後、エバポレーターを用いて酢酸エチルを全て揮発させて還元剤1、2の固体微粒子分散物3、4を得た。粒子径は、粒子の70wt％が1.0μｍ以下0.4μm 以上であった。
【０１１９】
（乳剤層塗布液の調製）
先に調製した有機酸銀微結晶分散物（銀1モル相当）に対し、ハロゲン化銀粒子Aをハロゲン化銀10モル％／有機酸銀相当と、以下のバインダーおよび素材を添加して乳剤塗布液とした。
【０１２０】
バインダー（表１） 430ｇ
色調剤１（メタノール溶媒として） 9.2ｇ
色調剤２（メタノール溶媒として） 6.7ｇ
トリブロモメチルフェニルスルホン 12ｇ
還元剤１ 98ｇ
（塗布試料6〜13については還元剤１の代わりに２を80g添加した。）
【０１２１】
【化４】

【０１２２】
上記において用いたバインダーのなかで、ラックスター（ＬＡＣＳＴＡＲ）3307B(大日本インキ化学工業（株）製；SBRラテックス）およびラックスター7132C（同社製；ＳＢＲラテックス）はいずれもスチレン−ブタジエン系コポリマーのポリマーラテックス（分散粒子の平均粒径はそれぞれ110nm、260nm）である。
【０１２３】
また、還元剤は、表１に示すように、溶媒を用いての添加、あるいは固体微粒子分散物による添加によった。また、色調剤は、上記のようにメタノールを用いた溶媒添加によった。
【０１２４】
（乳剤面保護層塗布液の調製）
イナートゼラチン10ｇに対し、下記界面活性剤Aを0.26g、下記界面活性剤Bを0.09g、シリカ微粒子（平均粒径サイズ2.5μｍ）0.9ｇ、１、２ー（ビスビニルスルホニルアセトアミド）エタン0.3ｇ、水64ｇ添加して表面保護層とした。
【０１２５】
【化５】

【０１２６】
（発色剤分散物の調製）
酢酸エチル３５ｇに対し、下記化合物１、２をそれぞれ２．５ｇ，７．５ｇ添加して攪拌して溶解した。その液に予め溶解したポリビニルアルコール１０重量％溶液を５０ｇ添加し、５分間ホモジナイザーで攪拌した。その後、酢酸エチルを脱溶媒で揮発させ、最後に水で希釈し、発色剤分散物を調製した。
【０１２７】
【化６】

【０１２８】
（バック面塗布液の調製）
ポリビニルアルコール３０ｇに対し、先に調製した発色剤分散物５０ｇ、下記化合物２０ｇ、水２５０ｇおよびシルデックスＨ１２１（洞海化学社製真球シリカ、平均サイズ１２μｍ）１．８ｇ添加してバック面塗布液とした。
【０１２９】
【化７】

【０１３０】
（塗布試料２〜１３の作成）
上記のように調製した乳剤層塗布液を、青色染料で色味付けした175μｍポリエチレンテレフタレート支持体上に銀の塗布量が1.9ｇ／m²となるように、そして乳剤塗布層上に乳剤面保護層塗布液をゼラチンの塗布量が1.8ｇ／m²となるように同時重層塗布した。乾燥後、乳剤層と反対の面上にバック面塗布液を660nmの光学濃度0.7となるように塗布し、熱現像感光材料である塗布試料２から１３の調製を終了した。
【０１３１】
（塗布試料１の作成）
水３００ml中にベヘン酸１０．６g を入れ９０℃に加熱溶解し、十分攪拌した状態で１Ｎの水酸化ナトリウム３１．１mlを添加し、そのままの状態で１時間放置した。その後３０℃に冷却し、１Ｎのリン酸７．０mlを添加して十分攪拌した状態でＮ−ブロモこはく酸イミド０．０１g を添加した。その後、予め調製したハロゲン化銀粒子Ａをベヘン酸に対して銀量として１０モル％となるように４０℃に加温した状態で攪拌しながら添加した。さらに１Ｎ硝酸銀水溶液２５mlを２分間かけて連続添加し、そのまま攪拌した状態で１時間放置した。その後攪拌しながらポリ酢酸ビニルの酢酸ｎ−ブチル溶液（１．２wt% ）３７g を徐々に添加して分散物のフロックを形成した。その後に水を取り除き、さらに２回の水洗を行った。次にポリビニルブチラール（分子量３０００）の２−ブタノン溶液（２．５wt% ）２０mlを添加して１０分間十分な速度で攪拌した。次にカルシウムブロマイド７０mg、２−ブタノン４０g およびポリビニルブチラール（分子量４０００）６．０g を添加して１時間十分な速度で攪拌し、有機脂肪酸銀乳剤を得た。この乳剤に塗布試料２で添加した還元剤、色調剤１、２およびトリブロモメチルフェニルスルホンをメチルエチルケトンあるいはジメチルホルムアミドに溶解して塗布試料２と同量添加し、支持体上に塗布した。その後表面保護層として下記の塗布液を調製しセルロースアセテートブチレートが２．５g/m²となるように塗布した。バック面塗布は塗布試料２と同様に行った。こうして塗布試料１を調製した。
【０１３２】
（表面保護層塗布液）
セルロースアセテートブチレート ７．５g
２−ブタノン ８０g
メタノール １０g
【０１３３】
（含水率の評価）
乳剤層に用いたポリマーの溶液（または分散液）をガラス板上に塗布して50℃で１時間乾燥し、厚さ100μｍのポリマーモデル膜を作成した（２種以上のポリマーを乳剤層にバインダーとして用いる場合、ポリマーをその比率で混合した）。その後、ポリマーモデル膜をガラス板から剥離し、25℃60％RHの条件下で３日放置し重量（Ｗ₁ ）を測定した。ついでポリマーモデル膜を真空中に３日放置し、すばやく重量のわかっている秤量瓶に入れて重量（Ｗ₀ ＝Ｗ₃ −Ｗ₂ ）を測定した。但し、Ｗ₃ はポリマーモデル膜と秤量瓶の重量、Ｗ₂ は秤量瓶の重量である。Ｗ₀ ，Ｗ₁ を用い、以下の式で含水率を求めた。
【０１３４】
平衡含水率＝｛（Ｗ₁ −Ｗ₀ ）／Ｗ₀ ｝×１００（％）
【０１３５】
（写真性能の評価）
647nmのKrレーザー感光計（最大出力500mW）で法線に対して３０度の角度で感光材料を露光した後、塗布試料を120℃で20秒間現像処理し、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.、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。感度については塗布試料2の感度を100として相対評価として表した。
【０１３６】
（自然経時保存性の評価）
それぞれの塗布試料を30.5cm×25.4cmに裁断し、角を0.5cmのラウンドコーナーとした。これらの各試料を25℃50％RHの条件下で１日放置し、感光材料をそれぞれ1枚ずつを防湿材料でできた袋の中に密封し、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）。この試料を写真性能の評価と同様に処理し、Dmin.を評価した。
【０１３７】
（面状の評価）
それぞれの塗布試料の面状を下記の観点で評価した。
○…実用的に許容される。
×…面状悪く不可。
【０１３８】
（銀色調の評価）
写真性能を評価した塗布サンプルの最高濃度部の色調を評価した。
【０１３９】
結果を表１に表した。塗布試料１に対しては還元剤含有塗布層の溶媒をメチルエチルケトンとして塗布試料を作成した。
【０１４０】
【表１】

【０１４１】
表１から、還元剤を固体微結晶分散物の形で添加し、バインダーの含水率が2wt％以下である塗布試料は、面状がよく、写真性能、自然経時性に優れ、かつ画像色調が黒調であることがわかる。また塗布試料１は特性上さほどの問題はないが、有機溶剤を用いているため、塗布液の取り扱いが困難であった。
【０１４２】
実施例２
（色調剤固体微粒子分散物１の調製）
上記色調剤1、2それぞれ2.9g、2.1gに対してヒドロキシプロピルセルロース2gと水93gを添加して良く攪拌して１０時間放置した。その後、平均直径0.5mmのジルコニア製ビーズを168g用意し、スラリーと一緒にベッセルにいれ、還元剤微結晶分散物の調製に用いたものと同じ分散機で10時間分散して色調剤１、２に対し固体微粒子分散物１を得た。粒子径は70wt％が1.0μｍ以下0.5μm 以上であった。
【０１４３】
（色調剤固体微粒子分散物２の調製）
上記色調剤1、2それぞれ2.9g、2.1gを酢酸エチルに添加して攪拌溶解し、ポリビニルアルコール1.6gを水に溶解した溶液を添加してホモジナイザーにて高速攪拌した。その後、酢酸エチルを全て揮発させて色調剤1、2の固体微粒子分散物２を得た。粒子径は、粒子の70wt％が1.0μｍ以下0.5μm 以上であった。
【０１４４】
（色調剤固体微粒子分散物３の調製）
上記色調剤1、2および下記構造の色調剤3をそれぞれ4.9g、3.6g、1.5gに対してヒドロキシプロピルメチルセルロース2gと水88g添加して良く攪拌し、10時間放置した。その後、平均直径0.5mmのジルコニア製ビーズを168g用意し、スラリーと一緒にベッセルにいれ、色調剤固体微粒子分散物１の調製で用いたものと同じ分散機で10時間分散し、色調剤固体微粒子分散物３を得た。粒子径は70wt％が1.0μｍ以下0.5μm 以上であった。
【０１４５】
【化８】

【０１４６】
（色調剤固体微粒子分散物４〜６の調製）
上記色調剤１，２，３をそれぞれ別々に色調剤固体微粒子分散物３と同様にして固体微粒子分散物４〜６を調製した。粒子径は分散物３と同様である。
【０１４７】
実施例１と同様にして塗布試料を作成した。ただし、色調剤は、表２に示すように、溶媒を用いての添加、あるいは固体微粒子分散物による添加によった。なお、塗布試料２４では色調剤固体微粒子分散物４〜６を混合して添加した。還元剤は還元剤固体微粒子分散物１を使用した。
【０１４８】
上記のようにして作成した塗布試料について実施例１と同様の評価を行った。結果を表２に示す。ただし、自然経時保存性に関してはＤmin.のみならず、感度についても評価を行った。感度は経時前の塗布試料１５の感度を１００とした相対値で示している。
【０１４９】
【表２】

【０１５０】
表２により、本発明において、色調剤を固体微粒子分散物として使用することによって、高感度で自然経時写真性の減感が非常に小さくなることがわかった。特に、２種以上の色調剤を同一の固体微粒子分散物として用いることが好ましいこともわかった。
【０１５１】
実施例３
実施例１で調製したハロゲン化銀粒子の調製において増感色素Ａ、Ｂの代わりに下記の増感色素Ｃ、Ｄを用いてその他はハロゲン化銀粒子Ａの調製と同様にしてハロゲン化銀粒子Bを調製しハロゲン化銀粒子Aの代わりに用いた。また、実施例１の写真性能の評価において用いた感光計の代わりに820nmのダイオードを備えたレーザー感光計を用いて写真性能および自然経時性能の評価を行った。他は全て実施例１と同様にして評価したところ、実施例１と同様の傾向を示し、還元剤を固体微粒子分散物で添加することによる本発明の効果を確認した。
【０１５２】
【化９】

【０１５３】
実施例４
実施例２において増感色素を実施例３の増感色素Ｃ，Ｄに変更して実施例３と同様に評価したところ、実施例２と同様の傾向を示し、本発明の効果を確認した。
【０１５４】
実施例５
実施例１の塗布試料２において、色調剤１、２を、メタノールによる溶媒添加にかえ、色調剤固体微粒子分散物１による添加を行ったところ、面状および自然経時保存性が改良され、実用上許容されるレベルとなった。
【０１５５】
【発明の効果】
本発明によれば、写真性能に優れ、自然経時性、面状を改良した熱現像感光材料が得られる。また、有機溶剤を用いない塗布液の調製が可能になるため、取り扱いが容易で、作業環境上好ましい。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photothermographic material, and relates to a laser image setter or a photosensitive material for a laser imager (hereinafter referred to as an LI photosensitive material), more specifically, excellent in graininess and high sharp image quality, Therefore, the present invention relates to a photothermographic material containing an LI photosensitive material that can faithfully reproduce image information.
[0002]
[Prior art]
In recent years, in the medical field, reduction of waste processing liquid has been strongly desired from the viewpoint of environmental protection and space saving. Accordingly, the present invention relates to a photothermographic material for photothermographic use for medical diagnosis and photographic technology that can be efficiently exposed by a laser imager or a laser image setter and can form a black and white image having high resolution and sharpness. Technology is needed. These photosensitive photothermographic materials can eliminate the use of solution processing chemicals, and supply customers with a simpler heat development processing system that does not impair the environment.
[0003]
Monolithic photosensitive materials for heat treatment containing photosensitive silver halide grains have been intensively studied in such photographic fields for many years. Such a heat-treated monosheet photosensitive material is based on a photosensitive silver halide that generates silver nuclei upon light irradiation, a non-photosensitive source of reducing silver, a reducing agent for silver ions, a toning agent, and a binder. Contained.
[0004]
Many of such monosheet photosensitive materials for heat treatment are obtained by applying a photosensitive component dispersed in an organic solvent such as methyl ethyl ketone, toluene, and methanol. It has drawbacks such as difficulty in handling during drying and adverse effects on the human body during the manufacturing process. As a technique for overcoming such drawbacks, Japanese Patent Application Laid-Open No. 8-95191 discloses a technique for applying 50 wt% or more of the total binder as gelatin. However, when gelatin is used for coating, there is a problem that the water content is high and the image color tone is brown with low sensitivity. Therefore, there is a need for a technique that overcomes these problems, reduces the difficulty of handling in obtaining a photosensitive material coating, and provides a photosensitive material with high sensitivity, improved coating surface, and natural aging.
[0005]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a photothermographic material that uses a coating solution of a photosensitive component that is easy to handle, has good photographic performance, is excellent in natural aging, and has an improved surface condition.
[0006]
[Means for Solving the Problems]
The present invention has achieved the above object by the means described below.
(1) a photosensitive silver halide on a support;Silver salt of long chain fatty carboxylic acidIn the photothermographic material having a bisphenol reducing agent for silver ions, a toning agent and a binder, the reducing agent and / or the toning agent is used as a solid fine particle dispersion, and the reducing agent and / or the toning agent A photothermographic material comprising a polymer latex as a main binder of a layer containing a solid fine particle dispersion.
(2) The photothermographic material according to the above (1), wherein the polymer latex is a latex of a polymer having an equilibrium water content of 2 wt% or less at 25 ° C. and 60% RH.
(3) The thermal development according to (1) or (2) above, wherein the layer containing the reducing agent and / or the color toning agent is formed by coating and drying using a coating solution in which 30 wt% or more of the solvent is water Photosensitive material.
(4) The photothermographic material according to any one of (1) to (3), wherein at least the reducing agent is a solid fine particle dispersion.
(5) The photothermographic material according to any one of (1) to (4), wherein the reducing agent and the toning agent are solid fine particle dispersions.
(6) The photothermographic photosensitive material according to any one of the above (1) to (5), wherein a solid fine particle dispersion prepared by using two or more kinds of the above-mentioned toning agents and simultaneously converting these two or more kinds of toning agents into a solid fine particle dispersion is used. material.
(7) The photothermographic material according to any one of (1) to (6), wherein a polymer latex is used as a main binder of the layer containing the photosensitive silver halide.
(8) The photothermographic material according to the above (7), wherein the polymer latex is a latex of a polymer having an equilibrium water content of 2 wt% or less at 25 ° C. and 60% RH.
(9) The thermal development according to any one of (1) to (8), wherein the photosensitive silver halide-containing layer is formed by coating and drying using a coating solution in which 30 wt% or more of the solvent is water. Photosensitive material.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
[0008]
The photothermographic material of the present invention uses a reducing agent and / or a color toning agent as a solid fine particle dispersion, and the main binder of the layer containing such a solid fine particle dispersion is derived from a polymer latex.
[0009]
By using the polymer latex as the main binder in this manner, it is possible to apply with an aqueous application solvent, and it is possible to prevent adverse effects during application work using an organic solvent. At the same time, unlike gelatin binders and the like conventionally used for coating with an aqueous coating solvent, a high sensitivity and good black image can be obtained without lowering the sensitivity and deteriorating the image color tone. Further, by using a reducing agent and / or a color toning agent as the solid fine particle dispersion, the coated surface state is improved, the fog (Dmin.) Is small, the sensitivity is high, and the storage stability with time is excellent. In particular, it is preferable to use at least a solid fine particle dispersion of a reducing agent in order to obtain such an effect, and in addition to this, by using a toning agent as a solid fine particle dispersion, it becomes possible to achieve higher sensitivity. Sensitivity decline with time can be suppressed. In the present invention, only the color toning agent may be used as the solid fine particle dispersion, and the effect of improving the coated surface state and improving the natural aging can be obtained.
[0010]
On the other hand, when both the reducing agent and the color toning agent are added not as a solid fine particle dispersion but using a solvent, the surface state of the coating is deteriorated, and depending on the solvent used, the problem of fogging and storage over time occurs. In addition, deterioration of photographic performance and storage stability with time are also caused by the use of a gelatin binder.
[0011]
As described above, the present invention facilitates the coating operation and improves the photographic performance, storage stability with time, and surface properties.
[0012]
  Used in the present inventionSilver salt of long-chain fatty carboxylic acid (hereinafter sometimes simply referred to as “organic silver salt”)As the reducing agent, a bisphenol reducing agent that reduces silver ions to metallic silver is used, and a hindered phenol reducing agent is 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 added to a layer other than the image forming layer, it is preferably used in an amount of 10 to 50% (mole) per 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.
[0013]
  BisphenolAs a reducing agentFor example, 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.Is mentioned.
[0014]
The reducing agent that can be used in the present invention is preferably a solid fine particle dispersion using a dispersant for the purpose of obtaining fine particles having a small particle size and no aggregation. The method of dispersing the reducing agent into solid fine particles is performed by using a known finer means (for example, ball mill, vibration ball mill, planetary ball mill, sand mill, colloid mill, jet mill, roller mill) in the presence of a dispersion aid. Can be dispersed.
[0015]
When the reducing agent that can be used in the present invention is dispersed into solid fine particles using a dispersant, for example, polyacrylic acid, acrylic acid copolymer, maleic acid copolymer, maleic acid monoester copolymer, and the like. Polymers, synthetic anionic polymers such as acryloylmethylpropanesulfone copolymer, semi-synthetic polymers such as carboxymethyl starch and carboxymethylcellulose, anionic polymers such as alginic acid and pectinic acid, JP-A-52-92716, WO88 / 04794 Anionic surfactants described in No. 7, etc., compounds described in Japanese Patent Application No. 7-350753, or known anionic, nonionic, cationic surfactants, other polyvinyl alcohol, polyvinyl pyrrolidone, carboxymethyl cellulose, hydroxy Propyl cellulose, hydroxypropyl methylcellulose It is possible to select and use a well-known polymer such as gelatin or a high-molecular compound existing in nature such as gelatin.
[0016]
Dispersant is generally mixed with reducing agent powder or wet cake reducing agent before dispersion and sent to the disperser as a slurry. It is good also as a powder or wet cake of a reducing agent by giving the process by. The pH may be controlled with a suitable pH adjusting agent before or after the 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 coarse dispersion, and the organic solvent is usually removed after the formation of fine particles.
[0018]
The prepared solid fine particle dispersion is stored with stirring for the purpose of suppressing sedimentation of fine particles during storage, or is stored in a highly viscous state (for example, in a jelly 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 bacteria during storage.
[0019]
The average particle diameter of the reducing agent fine particles in the solid fine particle dispersion is preferably 0.05 to 3.0 μm, and 70 wt% or more of the whole particles is 0.1 μm or more and 1.5 μm or less, and further 0.1 μm or more. It is preferably 1.0 μm or less. The particle size can be measured by a particle size measuring device using light scattering by light or coherent light such as laser light. The shape of the particles is almost spherical.
[0020]
The photothermographic material of the present invention is characterized by containing an additive known as a “coloring agent” for improving an 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.
[0021]
In photothermographic materials using organic silver salts, a wide range of color toning agents 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, 52-99813, 53-1020, 53-76020, 54-156524, 54-156525, 61-183642, JP 4-56848, JP-B 49- No. 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); Pyrazoles, isothiuronium derivatives and certain photobleaching agents (e.g., 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-1 Derivatives such as 1,4-phthalazinedione; combinations of phthalazinone and phthalic acid derivatives (eg, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid, and tetrachlorophthalic anhydride); Gin derivatives or metal salts or derivatives such as 4- (1-naphthyl) phthalazine, 6-chlorophthalazine, 5,7-dimethoxyphthalazine and 2,3-dihydrophthalazine; phthalazine and phthalic acid derivatives (eg phthalates) Acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride, etc.); quinazolinedione, benzoxazine or naphthoxazine derivatives; for in situ silver halide generation as well as color modifiers Rhodium complexes that also function as a source of halide ions, such as ammonium hexachlororhodium (III), rhodium bromide, rhodium nitrate and potassium hexachlororhodium (III); inorganic peroxides and persulfates, such as diperoxide Ammonium sulfide and hydrogen peroxide; 1,3-benzoxazine-2,4-dione, 8-methyl Benzoxazine-2,4-diones such as 1,3-benzoxazine-2,4-dione and 6-nitro-1,3-benzoxazine-2,4-dione; pyrimidines and asymmetric-triazines (eg 2,4-dihydroxypyrimidine, 2-hydroxy-4-aminopyrimidine, etc.), azauracil, and tetraazapentalene derivatives (e.g., 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).
[0022]
The toning agent that can be used in the present invention is preferably contained in a coated sample as a solid fine particle dispersion using a dispersant for the purpose of obtaining fine particles having a small particle size and no aggregation. The same method as described in the method of dispersing the reducing agent used in the present invention into the solid fine particle dispersion can be applied to the method of dispersing the color toning agent in the form of solid fine particles. The toning agent may contain two or more types of compounds, and one type each may be used as a solid fine particle dispersion. However, in the present invention, it is preferable that two or more types are simultaneously converted into a solid fine particle dispersion. This is preferable from the viewpoint of preventing a decrease in sensitivity over time.
[0023]
The average particle diameter of the colorant fine particles in the solid fine particle dispersion is preferably 0.05 to 3.0 μm, and 70 wt% or more of the whole particles is 0.1 μm or more and 1.5 μm or less, and further 0.1 μm or more. It is preferably 1.0 μm or less. The particle size can be measured by a particle size measuring device using light scattering by light or coherent light such as laser light. The shape of the particles is almost spherical.
[0024]
The polymer latex used as the main binder of the layer containing the reducing agent and / or the color tone of the photothermographic material of the invention will be described.
[0025]
The polymer latex referred to here is a polymer in which a water-insoluble hydrophobic polymer is 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.
[0026]
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 Kobunshi Publishing Co., Ltd. (1993)), “Synthetic Latex Chemistry (written by Soichi Muroi, published by Kobunshi Publishing Co., Ltd. (1970))”, and the like.
[0027]
The average particle size of the dispersed particles is preferably 1 to 50000 nm, more preferably about 5 to 1000 nm. There is no particular limitation on the particle size distribution of the dispersed particles.
[0028]
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, and polyolefin resins.
[0029]
The polymer may be a linear polymer, a branched polymer, or a crosslinked polymer.
[0030]
The polymer may be a so-called homopolymer in which a single monomer is polymerized, or a copolymer in which two or more monomers are polymerized.
[0031]
In the case of a copolymer, it may be a random copolymer or a block copolymer.
[0032]
The molecular weight of the polymer is 5,000 to 100,000, preferably about 10,000 to 500,000 as the number average molecular weight Mn. When the molecular weight is too small, the mechanical strength of the photosensitive layer is insufficient, and when the molecular weight is too large, the film formability is poor and is not preferable.
[0033]
The polymer latex polymer used in the present invention preferably has an equilibrium moisture content of 2 wt% or less, more preferably 1 wt% or less at 25 ° C. and 60% RH. The lower limit of the equilibrium moisture content is not particularly limited, but is preferably 0.01 wt%, more preferably 0.03 wt%. For the definition and measurement 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. Specifically, the equilibrium water content at 25 ° C. and 60% RH is the weight W of the polymer that has reached humidity control equilibrium in an atmosphere of 25 ° C. and 60% RH.₁And the weight of the polymer in an absolutely dry state at 25 ° C. W₀Can be expressed as follows.
[0034]
"Equilibrium moisture content at 25 ℃ 60% RH" = {(W₁-W₀) / W₀} × 100 (wt%)
[0035]
Actual measurement can be performed as shown in the Examples described later.
[0036]
Such polymers are also commercially available, and the following polymers can be used as the polymer latex. For example, as an example of acrylic resin, Sebian A-4635,46583, 4601 (above Daicel Chemical Industries, Ltd.), Nipol Lx811, 814, 821, 820, 857 (above made by Nippon Zeon Co., Ltd.) , FINETEX ES650, 611, 675, 850 (made by Dainippon Ink Chemical Co., Ltd.), WD-size, WMS (made by Eastman Chemical), and other polyurethane resins include HYDRAN AP10, 20, 30, 40 (more than large Nippon Ink Chemical Co., Ltd.) and other rubber resins such as LACSTAR 7310K, 3307B, 4700H, 7132C, DS206 (above Dainippon Ink and Chemicals), Nipol Lx416, 433, 410, 438C, 2507, (above Nippon Zeon Co., Ltd.), vinyl chloride resin G351, G576 (Nippon ZEON Co., Ltd.), vinylidene chloride L502, L513 (Asahi Kasei Co., Ltd.), etc. Are Chemipearl S120, SA100 (Mitsui Petrochemical Co., Ltd.) Can.
[0037]
These polymers may be used alone as a polymer latex, or may be used as a blend of two or more as required.
[0038]
The polymer latex used in the present invention is particularly preferably a styrene-butadiene copolymer latex. The weight ratio of the styrene monomer unit to the butadiene monomer unit in the styrene-butadiene copolymer is preferably 50:50 to 95: 5. The proportion of the styrene monomer unit and the butadiene monomer unit in the copolymer is preferably 50 to 99% by weight. The preferred molecular weight range is the same as described above.
[0039]
Examples of latexes of styrene-butadiene copolymer that are preferably used in the present invention include commercially available products such as LACSTAR 3307B, 7132C, DS206, Nipol Lx416, and Lx433.
[0040]
The main binder in the layer containing the reducing agent and / or toning agent of the present invention means that 50 wt% or more, more preferably 70 wt% or more of the total binder in the layer is a polymer binder derived from the polymer latex. .
[0041]
The layer containing the reducing agent and / or colorant of the present invention may contain gelatin, polyvinyl alcohol, methyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, hydroxy in an amount of 50 wt% or less of the total binder, and less than 50 wt%, if necessary. A hydrophilic polymer such as propylmethylcellulose may be added. The addition amount of these hydrophilic polymers is more preferably 30 wt% or less, further less than 30 wt%, particularly 15 wt% or less of the total binder in the layer.
[0042]
The layer containing the reducing agent and / or toning agent of the present invention can be formed by applying an aqueous coating solution and then drying, and applying it without substantially using an organic solvent (for example, methyl ethyl ketone, methanol). Therefore, it is easy to handle at the time of preparing the photosensitive component or coating and drying, and there is no adverse effect on the human body in the manufacturing process. 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.
[0043]
The reducing agent and / or toning agent may be contained in a layer containing a photosensitive silver halide and / or an organic silver salt, or may be contained in another non-photosensitive layer. Usually, the photosensitive silver halide and the organic silver salt are contained in the same photosensitive layer (emulsion layer) or organic silver salt-containing layer, and in this photosensitive layer (organic silver salt-containing layer), a reducing agent, In many cases, the composition contains a color preparation.
[0044]
As the binder of the layer containing silver halide and / or organic silver salt in the present invention, well-known natural or synthetic resins such as gelatin, polyvinyl acetal, polyvinyl chloride, polyvinyl acetate, polyolefin, polyester, polystyrene, An arbitrary one can be selected from polyacrylonitrile, polycarbonate and the like. Of course, copolymers and terpolymers are also included. Preferred polymers include polyvinyl butyral, butyl ethyl cellulose, methacrylate copolymer, maleic anhydride ester copolymer, polystyrene and butadiene-styrene copolymer. In the present invention, it is preferable to use a polymer in which a hydrophobic polymer is dispersed in an aqueous solvent. preferable. The aqueous solvent here is water or a mixture of water and 70 wt% or less of a water-miscible organic solvent. Examples of the water-miscible organic solvent include methanol, ethanol, propanol, ethyl acetate, dimethylformamide, butyl cellosolve and the like. The term “dispersed” as used herein refers to a state in which a polymer is not thermodynamically dissolved in a solvent but is dispersed in an aqueous solvent in a latex, micelle state, or molecularly dispersed state. In the present invention, those having an equilibrium water content of 2 wt% or less at 25 ° C. and 60% RH are particularly preferred. As a matter of course, when the reducing agent and / or toning agent is contained in a layer containing photosensitive silver halide and / or organic silver salt, 50% by weight or more of the binder is a binder satisfying the above-mentioned equilibrium water content. .
[0045]
The binder of the layer containing the reducing agent and / or the color tone of the present invention can be preferably used for a photosensitive layer containing silver halide.
The amount of binder in the layer containing the reducing agent and / or the color toning agent is 1 m.²0.2 to 10 g / m in terms of coating amount per unit²Is preferable, and more preferably 0.5 to 5 g / m.²It is. The binder amount of the photosensitive layer (including the case where a reducing agent and / or a color tone agent is contained) is 1 m of photosensitive material.²0.5 to 20 g / m in terms of coating amount per unit²Is preferable, and more preferably 2 to 15 g / m.², More preferably 3 to 10 g / m²It is.
[0046]
  Can be used in the present inventionSilver salt of long chain fatty carboxylic acidIs relatively stable to light, but produces a silver image when heated to 80 ° C. or higher in the presence of an exposed photocatalyst (such as a latent image of a photosensitive silver halide) and a reducing agent. A silver salt of a long-chain fatty carboxylic acid which is a silver salt to be formed and has 10 to 30 (preferably 15 to 28) carbon atomsIt is.The silver supply material can preferably constitute about 5-30% by weight of the imaging layer.Long chainPreferred examples of the fatty acid carboxylic acid silver salt include silver behenate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, silver linoleate, and mixtures thereof. .
[0048]
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. As another method for measuring monodispersity, there is a method for obtaining the standard deviation of the volume-weighted average diameter of the organic silver salt, and the percentage (variation coefficient) of the value divided by the volume-weighted average diameter is preferably 100% or less, more Preferably it is 80% or less, more preferably 50% or less. As a measuring method, for example, it is obtained from the particle size (volume load 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.
[0049]
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. .
[0050]
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. As a specific method for dispersing the organic silver salt in the form of solid fine particles, a method of making the reducing agent of the present invention into a solid fine particle dispersion can be preferably used.
[0051]
The organic silver salt of the present invention can be used in a desired amount, but is 0.1 to 5 g / m.²Is more preferable, and more preferably 1 to 3 g / m.²It is.
[0052]
The method for forming photosensitive silver halide in the present invention is 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 further preferably 0.02 μm or more. 0.12 μm or less is preferable. 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.
[0053]
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 Miller index {100} plane is calculated by T.Tani; J.Imaging Sci., 29, 165 (1985) using the adsorption dependence of {111} plane and {100} plane in sensitizing dye adsorption. 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.
[0054]
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 metal complex in the silver halide may be contained uniformly, may be contained in the core part at a high concentration, or may be contained in the shell part at a high concentration, and there is no particular limitation.
[0055]
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.
[0056]
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 in 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.
[0057]
The amount of the photosensitive silver halide used in the present invention is preferably 0.01 to 0.5 mol or less, more preferably 0.02 to 0.3 mol, and more preferably 0.03 to 0.25 mol with respect to 1 mol of the organic silver salt. Is 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.
[0058]
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. However, N-halogenoimide (N-bromosuccinimide, etc.), halogenated quaternary nitrogen compound (odor) And tetrabutylammonium bromide), and halogenated quaternary nitrogen salts and halogen molecule associations (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 rhodate, etc.) and halogen molecules (bromine, chlorine, iodine). Moreover, you may use desired organic inorganic halide together.
[0059]
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.
[0060]
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, cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, holopolar cyanine dyes, styryl dyes, hemicyanine dyes, oxonol dyes, hemioxonol dyes, and 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.
[0061]
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.
[0062]
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 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 basic nuclei described above. 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.
[0063]
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- No. 500926, dyes described in U.S. Pat.No. 5,541,054), dyes having a carboxylic acid group (for example, dyes described in JP-A Nos. 3-163440 and 6-301141, US Pat. No. 5,441,899), merocyanine dyes, 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).
[0064]
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.
[0065]
These sensitizing dyes may be used alone or in combination of two or more. A combination of sensitizing dyes is often used for the purpose of supersensitization. Along with the sensitizing dye, the emulsion itself may contain a dye having no spectral sensitizing action or a substance that does not substantially absorb visible light and exhibits supersensitization. Useful sensitizing dyes, combinations of dyes exhibiting supersensitization, and substances exhibiting supersensitization are described in Research Disclosure 176, 17643 (issued December 1978), page 23, Section J, or JP-B 49-25500. No. 43-4933, JP-A-59-19032, 59-192242 and the like.
[0066]
Two or more sensitizing dyes used in the present invention may be used in combination. In order to add sensitizing dyes to silver halide emulsions, they may be dispersed directly in the emulsion, or water, methanol, ethanol, propanol, acetone, methyl cellosolve, 2,2,3,3 -Solvent alone such as tetrafluoropropanol, 2,2,2-trifluoroethanol, 3-methoxy-1-propanol, 3-methoxy-1-butanol, 1-methoxy-2-propanol, N, N-dimethylformamide Alternatively, it may be dissolved in a mixed solvent and added to the emulsion.
[0067]
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. Add to emulsion as aqueous solution by coexistence, and add aqueous solution or colloidal dispersion in the presence of surfactant as disclosed in US Pat. Nos. 3,822,135, 4,006,025, etc. 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.
[0068]
The time when the sensitizing dye used in the present invention is added to the silver halide emulsion of the present invention may be during any step of emulsion preparation that has been found useful. For example, as disclosed in the specifications of U.S. Pat.Nos. 2,735,766, 3,628,960, 4,183,756, 4,225,666, JP-A-58-184142, 60-196749, etc., a silver halide grain forming step Or / and the time before desalting, during the 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.
[0069]
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 is 10 per mole of silver halide in the photosensitive layer.^-6~ 1 mole is preferred
10^-Four-10^-1Mole is more preferred.
[0070]
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. Polyvalent metal salts, thiuronium salts described in US Pat. No. 3,220,839, and palladium, platinum and gold salts described in US Pat. Nos. 2,566,263 and 2,597,915, halogen-substituted organic compounds described in US Pat. Nos. 4,108,665 and 4,442,202 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.
[0071]
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.
[0072]
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.
[0073]
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.
[0074]
The photothermographic material in the invention may contain benzoic acids for the purpose of increasing sensitivity and preventing fog. The benzoic acid derivatives 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. 8-512242, 8-151241, and 8-98051. And the compounds described in the above. The benzoic acids of the present invention may be added to any part of the light-sensitive material, but the addition layer is preferably added to the layer having the photosensitive layer, and more preferably added to the organic silver salt-containing layer. . 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.
[0075]
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. .
[0076]
When a mercapto compound is used in the present invention, any structure may be used, but those represented by Ar-SM and Ar-S-S-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 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 (e.g., Br and Cl), hydroxy, amino, carboxy, alkyl (e.g., having one or more carbon atoms, preferably 1 to 4 carbon atoms) and alkoxy ( For example, it may have one selected from a 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.
[0077]
The addition amount of these mercapto compounds is preferably in the range of 0.001 to 1.0 mol per mol of silver in the emulsion layer, and more preferably 0.01 to 0.3 mol per mol of silver.
[0078]
In the photosensitive layer in the present invention, a polyhydric alcohol (for example, glycerin and diol of the kind described in US Pat. No. 2,960,404), a fatty acid or an ester described in US Pat. Nos. 2,588,765 and 3,121,060, as a plasticizer and a lubricant, Silicone resin described in British Patent 955,061 can be used
.
[0079]
The photosensitive material in the present invention can be provided with a surface protective layer for the purpose of preventing adhesion of the image forming layer. Any adhesion preventing material may be used as the surface protective layer. Examples of anti-adhesive materials include wax, silica particles, styrene-containing elastomeric block copolymers (e.g., styrene-butadiene-styrene, styrene-isoprene-styrene), cellulose acetate, cellulose acetate butyrate, cellulose propionate, and these There is a mixture.
[0080]
For the emulsion layer or the protective layer of the emulsion layer in the present invention, light absorbing materials and filter dyes described in U.S. Pat.Nos. 3,253,921, 2,274,782, 2,527,583, and 2,956,879 can be used. . 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.
[0081]
In the emulsion layer or the protective layer of the emulsion layer in the present invention, a matting agent such as starch, titanium dioxide, zinc oxide, silica, polymer beads including beads of the type described in US Pat. Nos. 2,992,101 and 2,701,245, etc. Can be contained. The matte degree of the emulsion surface may be any value as long as no stardust failure occurs, but the Beck smoothness is preferably 200 seconds or more and 10,000 seconds or less, and particularly preferably 300 seconds or more and 10,000 seconds or less.
[0082]
The heat-developable photographic emulsion 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 configuration must contain an organic silver salt and silver halide in the first emulsion layer (usually the layer adjacent to the support) and some other components in the second or both layers. Don't be. However, a two-layer configuration comprising a single emulsion layer containing all components and a protective topcoat is also conceivable. The construction of a multicolor photosensitive photothermographic material may include a combination of these two layers for each color, and 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 photosensitive layer (emulsion layer) is generally a functional or non-functional barrier between each photosensitive layer as described in US Pat. No. 4,460,681. By using layers, they are kept distinct from each other.
[0083]
Various dyes can be used in the photosensitive layer of the present invention from the viewpoint of improving the color tone and preventing irradiation. Any dye may be used for the photosensitive layer of the present invention, for example, pyrazoloazole dye, anthraquinone dye, azo dye, azomethine dye, oxonol dye, carbocyanine dye, styryl dye, triphenylmethane dye, indoaniline dye And indophenol dyes. 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, compounds 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 1m²It is preferably used in the range of 1 μg or more and 1 g or less.
[0084]
In the present invention, the antihalation layer can be provided on the side farther from the light source than 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 less than 0.3.
When antihalation dyes are used in the present invention, such dyes have the desired absorption in the wavelength range, and the absorption in the visible region is sufficiently small after processing, so that the preferred absorbance spectrum shape of the antihalation layer can be obtained. Any compound may be used. For example, the following is disclosed, but the present invention is not limited to this. As a single dye, JP-A-59-56458, JP-A-2-216140, JP-A-7-13295, JP-A-111432, U.S. Pat.No. 5,380,635, JP-A-2-68539, page 13, lower left column From line 1 to page 14, lower left column, line 9, line 3-24539, page 14, lower left column to page 16, lower right column, the 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, JP-B-48-33692, JP-B-50-16648, JP-B-2-41734, US Patents 4,088,497, 4,283,487, 4,548,896, and 5,187,049.
[0085]
The photothermographic material of the present invention is a so-called single-sided photosensitive material having a photosensitive layer containing at least one silver halide emulsion on one side of a support and a back layer (backing layer) on the other side. Preferably there is.
[0086]
In the present invention, a matte agent may be added to the single-sided photosensitive material for improving transportability. The matting agent is generally fine particles of an organic or inorganic compound that is insoluble in water. Any matting agent can be used.For example, organic matting agents described in U.S. Pat.Nos. 1,939,213, 2,701,245, 2,322,037, 3,262,782, 3,539,344, 3,767,448, etc., 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. The size and shape of the matting agent are not particularly limited, and those having an arbitrary particle size can be used. In the practice of the present invention, it is preferable to use one having a particle size of 0.1 μm to 30 μm. The particle size distribution of the matting agent may be narrow or wide. On the other hand, since the matting agent greatly affects the haze and surface gloss of the light-sensitive material, the particle size, shape, and particle size distribution can be brought into a state as required by preparing the matting agent or mixing a plurality of matting agents. preferable.
[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 photosensitive material, the layer functioning as the outermost surface layer, or a layer close to the outer surface, and is contained in a layer acting as a so-called protective layer. It is preferable.
[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 (e.g., poly (vinyl formal) and poly (vinyl butyral)), poly (esters), poly (urethanes) ), Phenoxy resin, poly (vinylidene chloride) Poly (epoxides), poly (carbonates), poly (vinyl acetate), cellulose esters, and polyamides. The binder may be formed from water or an organic solvent or emulsion.
[0090]
In the present invention, the back layer preferably has a maximum absorption of 0.3 or more and 2 or less in a desired wavelength range, more preferably 0.5 or more and 2 or less, and an absorption in the visible region after processing of 0.001 or more. It is preferably less than 0.5, more preferably a layer having an optical density of 0.001 or more and less than 0.3. Examples of the antihalation dye used for the back layer are the same as those of the antihalation layer described above.
[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 such as the present invention.
[0092]
A hardener may be used in each layer such as the photosensitive 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]
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 partially acetylated or baryta and / or α-olefin polymers, especially polymers of α-olefins of 2 to 10 carbon atoms such as polyethylene, polypropylene, ethylene-butene copolymers A printed paper support is typically used. The support may be transparent or opaque, but is preferably transparent.
[0095]
The light-sensitive material in the present invention is an antistatic or conductive layer, for example, a soluble salt (for example, chloride, nitrate, etc.), a deposited metal layer, an ionic polymer as described in US Pat. Nos. 2,861,056 and 3,206,312 or a US You may have a layer containing the insoluble inorganic salt etc. as described in patent 3,428,451.
[0096]
As a method for obtaining a color image using the photothermographic material in the invention, there is a method described in JP-A-7-13295, page 10, left column, line 43 to 11, left column, line 40. Color dye image stabilizers are exemplified in British Patent 1,326,889, U.S. Patent 3,432,300, 3,698,909, 3,574,627, 3,573,050, 3,764,337 and 4,042,394.
[0097]
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 No. 837,095.
[0098]
Additional layers in the photothermographic material of the present invention, such as a dye-receiving layer for receiving a moving dye image, an opacifying layer when reflective printing is desired, a protective topcoat layer, and a primer known in the photothermographic art Layers can be included. The light-sensitive material of the present invention can preferably form an image with only one light-sensitive material, and it is preferable that a functional layer necessary for image formation such as an image receiving layer does not become another light-sensitive material.
[0099]
The photosensitive 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.
[0100]
The light-sensitive material of the present invention may be exposed by any method, but laser light is preferred as the exposure light source. As the laser 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.
[0101]
The photosensitive material of the present invention has a low haze upon exposure and tends to generate interference fringes. As this interference fringe generation prevention technique, a laser beam disclosed in Japanese Patent Laid-Open No. 5-11548 etc. is incident obliquely on the photosensitive material, and a multimode laser disclosed in WO95 / 31754 There are known methods of using these, and it is preferable to use these techniques.
[0102]
In order to expose the light-sensitive material of the present invention, exposure is performed so that laser beams overlap as disclosed in SPIE vol. 169 Laser Printing, pages 116-128 (1979), JP-A-4-51043, WO95 / 31754, etc. However, it is preferable to prevent the scanning lines from being seen.
[0103]
In the present invention, a hydrazine derivative may be used. When a hydrazine derivative is used in the present invention, a compound of the general formula (I) described in Japanese Patent Application No. 6-47961 is used. Specifically, compounds represented by I-1 to I-53 described in the same specification are used.
[0104]
The following hydrazine derivatives are also preferably used.
[0105]
A compound represented by (Chemical formula 1) described in JP-B-6-77138, specifically, compounds described on pages 3 and 4 of the publication. A compound represented by the general formula (I) described in JP-B-6-93082, specifically, compounds 1 to 38 described on pages 8 to 18 of the publication. Compounds represented by general formula (4), general formula (5) and general formula (6) described in JP-A-6-230497, specifically, compound 4- 1 to Compound 4-10, Compounds 5-1 to 5-42 described on pages 28 to 36, and Compounds 6-1 to 6-7 described on pages 39 and 40. Compounds represented by the general formula (1) and general formula (2) described in JP-A-62-289520, specifically, compounds 1-1) to 1-17 described on pages 5 to 7 of the publication ) And 2-1). Compounds represented by (Chemical Formula 2) and (Chemical Formula 3) described in JP-A-6-313936, specifically, compounds described on pages 6 to 19 of the publication. A compound represented by (Chemical formula 1) described in JP-A-6-313951, specifically, a compound described on pages 3 to 5 of the publication. Compounds represented by general formula (I) described in JP-A-7-5610, specifically, compounds I-1 to I-38 described on pages 5 to 10 of the publication. A compound represented by the general formula (II) described in JP-A-7-77783, specifically, compounds II-1 to II-102 described on pages 10 to 27 of the same publication. Compounds represented by general formula (H) and general formula (Ha) described in JP-A-7-104426, specifically, compounds H-1 to H-44 described on pages 8 to 15 of the publication. A compound having an anionic group or a nonionic group that forms an intramolecular hydrogen bond with a hydrogen atom of hydrazine in the vicinity of the hydrazine group described in Japanese Patent Application No. 7-191007, and particularly represented by the general formula (A) A compound represented by the general formula (B), the general formula (C), the general formula (D), the general formula (E), or the general formula (F), specifically, the compound N- 1 to N-30. Compounds represented by the general formula (1) described in Japanese Patent Application No. 7-191007, specifically, compounds D-1 to D-55 described in the same specification.
[0106]
When a hydrazine nucleating agent is used in the present invention, a suitable water-miscible organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone), dimethylformamide, dimethyl sulfoxide And dissolved in methyl cellosolve.
[0107]
In addition, using a well-known emulsification dispersion method, it is dissolved using an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, or an auxiliary solvent such as ethyl acetate or cyclohexanone, and mechanically emulsified and dispersed An object can be made and used. Alternatively, a hydrazine derivative powder can be dispersed in water by a ball mill, a colloid mill, or ultrasonic waves by a method known as a solid dispersion method.
[0108]
When a hydrazine nucleating agent is used in the present invention, it may be added to any layer of the silver halide emulsion layer or other hydrophilic colloid layer on the side of the silver halide emulsion layer relative to the support. It is preferably added to the silver halide emulsion layer or the hydrophilic colloid layer adjacent thereto.
[0109]
The addition amount of the nucleating agent of the present invention is preferably 1 μm to 10 mmol, more preferably 10 μm to 5 mmol, and most preferably 20 μm to 5 mmol, per 1 mol of silver halide.
[0110]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.
[0111]
Example 1
(Preparation of silver halide grains A)
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 40 ° C., then add 159 ml of an aqueous solution containing 18.6 g of silver nitrate, and 92: 8 moles of potassium bromide and potassium iodide. The aqueous solution contained in a ratio was added over 10 minutes by the controlled double jet method while maintaining pAg 7.7. Next, 476 ml of an aqueous solution containing 55.4 g of silver nitrate and an aqueous solution containing 8 μmol / liter of hexapotassium iridium dichloride and 1 mol / liter of potassium bromide were added over 30 minutes by the controlled double jet method while maintaining pAg7.7. did. Thereafter, the pH was lowered to cause coagulation sedimentation, followed by desalting, and 0.1 g phenoxyethanol was added to adjust the pH to 5.9 and pAg 8.0. Cubic grains having a silver iodide content core of 8 mol%, an average of 2 mol%, a grain size of 0.07 μm, a coefficient of variation of projected area diameter of 8%, and a (100) plane ratio of 86%.
[0112]
The obtained silver halide grains were heated to 60 ° C., and 85 μmol of sodium thiosulfate and 11 μm of 2,3,4,5,6-pentafluorophenyldiphenylphosphine selenide per mol of silver. Mole, 2 μmol of the following tellurium compound 1, 3.3 μmol of chloroauric acid, and 230 μmol of thiocyanic acid were added and aged for 120 minutes. Thereafter, the temperature was changed to 50 ° C. and the following sensitizing dye A was added at 5 × 10 5 to 1 mol of silver halide.^-FourMol, 2 × 10 of the following sensitizing dye B^-FourAdded with molar stirring. Further, 3.5 mol% of potassium iodide was added to the silver, stirred for 30 minutes, and rapidly cooled to 30 ° C. to complete the preparation of silver halide grains A.
[0113]
[Chemical 1]

[0114]
[Chemical 2]

[0115]
(Preparation of organic acid silver microcrystal dispersion)
40 g of behenic acid, 7.3 g of stearic acid, and 500 ml of water were stirred at a temperature of 90 ° C. for 15 minutes, 187 ml of 1N-NaOH was added over 15 minutes, 61 ml of 1N nitric acid aqueous solution was added, and the temperature was lowered to 50 ° C. Next, 124 ml of 1N silver nitrate aqueous solution was added over 2 minutes, and the mixture was stirred as it was for 30 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. The solid content thus obtained was handled as a wet cake without being dried, and 12 g of polyvinyl alcohol and 150 ml of water were added to the wet cake corresponding to 34.8 g of the dry solid content and mixed well to obtain a slurry. Prepare 840g of zirconia beads with an average diameter of 0.5mm, put them in a vessel together with the slurry, disperse for 5 hours with a disperser (1 / 4G sand grinder mill: manufactured by IMEX Co., Ltd.), and observe the average short diameter by electron microscope observation Preparation of a fine crystal dispersion of organic acid silver, which is needle-like particles having a 0.04 μm, average major axis of 0.8 μm, and a projected area variation coefficient of 30%, was completed.
[0116]
(Preparation of reducing agent solid fine particle dispersions 1 and 2)
4 g of hydroxypropyl cellulose and 86 g of water were added to 10 g of each of the following reducing agents 1 and 2, and the mixture was stirred well and left as a slurry for 10 hours. Thereafter, 168 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 10 hours with the same disperser used for the preparation of the organic acid silver microcrystal dispersion. Solid fine particle dispersions 1 and 2 were obtained for 2. As for the particle size, 70 wt% was 1.0 μm or less and 0.4 μm or more.
[0117]
[Chemical 3]

[0118]
(Preparation of reducing agent solid fine particle dispersion 3, 4)
4.5 g of each of the reducing agents 1 and 2 was added to ethyl acetate and dissolved by stirring. A solution prepared by dissolving 1.6 g of polyvinyl alcohol in water was added, and the mixture was stirred at high speed with a homogenizer. Thereafter, all of ethyl acetate was volatilized using an evaporator to obtain solid fine particle dispersions 3 and 4 of reducing agents 1 and 2. As for the particle diameter, 70 wt% of the particles were 1.0 μm or less and 0.4 μm or more.
[0119]
(Preparation of emulsion layer coating solution)
Emulsion coating by adding silver halide grains A to 10 mol% of silver halide / corresponding to organic acid silver, and the following binders and materials to the organic acid silver microcrystal dispersion prepared earlier (equivalent to 1 mol of silver) Liquid.
[0120]
Binder (Table 1) 430g
Coloring agent 1 (as methanol solvent) 9.2g
Coloring agent 2 (as methanol solvent) 6.7g
12g tribromomethylphenylsulfone
Reducing agent 1 98g
(For coated samples 6 to 13, 80 g of 2 was added instead of reducing agent 1.)
[0121]
[Formula 4]

[0122]
Among the binders used in the above, LACSTAR 3307B (manufactured by Dainippon Ink & Chemicals, Inc .; SBR latex) and LUXSTAR 7132C (manufactured by the same company; SBR latex) are both polymers of styrene-butadiene copolymers. Latex (the average particle diameter of the dispersed particles is 110 nm and 260 nm, respectively).
[0123]
Further, as shown in Table 1, the reducing agent was added by using a solvent or by addition with a solid fine particle dispersion. The colorant was based on the addition of a solvent using methanol as described above.
[0124]
(Preparation of emulsion surface protective layer coating solution)
10 g of inert gelatin, 0.26 g of the following surfactant A, 0.09 g of the following surfactant B, 0.9 g of silica fine particles (average particle size 2.5 μm), 0.3 g of 1,2- (bisvinylsulfonylacetamide) ethane Then, 64 g of water was added to form a surface protective layer.
[0125]
[Chemical formula 5]

[0126]
(Preparation of color former dispersion)
2.5 g and 7.5 g of the following compounds 1 and 2 were added to 35 g of ethyl acetate and dissolved by stirring. 50 g of a 10% by weight solution of polyvinyl alcohol previously dissolved in the solution was added and stirred for 5 minutes with a homogenizer. Thereafter, ethyl acetate was volatilized by removing the solvent, and finally diluted with water to prepare a color former dispersion.
[0127]
[Chemical 6]

[0128]
(Preparation of back surface coating solution)
50 g of the previously prepared color former dispersion, 20 g of the following compound, 250 g of water, and 1.8 g of Sildex H121 (Doukai Chemical Co., Ltd. true spherical silica, average size 12 μm) are added to 30 g of polyvinyl alcohol, and the back surface coating solution It was.
[0129]
[Chemical 7]

[0130]
(Preparation of coated samples 2 to 13)
The emulsion layer coating solution prepared as described above was coated with a silver coating amount of 1.9 g / m on a 175 μm polyethylene terephthalate support tinted with a blue dye.²And an emulsion surface protective layer coating solution on the emulsion coating layer with a gelatin coating amount of 1.8 g / m 2.²Simultaneous multilayer coating was applied so that After drying, a back surface coating solution was coated on the surface opposite to the emulsion layer so that the optical density at 660 nm was 0.7, and preparation of coated samples 2 to 13 as photothermographic materials was completed.
[0131]
(Preparation of coated sample 1)
10.6 g of behenic acid was placed in 300 ml of water, dissolved by heating at 90 ° C., 31.1 ml of 1N sodium hydroxide was added with sufficient stirring, and the mixture was left as it was for 1 hour. After cooling to 30 ° C., 7.0 g of 1N phosphoric acid was added and 0.01 g of N-bromosuccinimide was added with sufficient stirring. Thereafter, silver halide grains A prepared in advance were added with stirring in a state heated to 40 ° C. so that the amount of silver was 10 mol% with respect to behenic acid. Further, 25 ml of 1N silver nitrate aqueous solution was continuously added over 2 minutes, and the mixture was left for 1 hour with stirring. Thereafter, 37 g of a polyvinyl acetate n-butyl acetate solution (1.2 wt%) was gradually added with stirring to form a floc of the dispersion. Thereafter, the water was removed, and washing was further performed twice. Next, 20 ml of a 2-butanone solution (2.5 wt%) of polyvinyl butyral (molecular weight 3000) was added and stirred at a sufficient speed for 10 minutes. Next, 70 mg of calcium bromide, 40 g of 2-butanone and 6.0 g of polyvinyl butyral (molecular weight 4000) were added and stirred at a sufficient speed for 1 hour to obtain an organic fatty acid silver emulsion. To this emulsion, the reducing agent, colorant 1 and 2, and tribromomethylphenylsulfone added in coating sample 2 were dissolved in methyl ethyl ketone or dimethylformamide and added in the same amount as in coating sample 2, and coated on the support. Thereafter, the following coating solution was prepared as a surface protective layer, and the cellulose acetate butyrate was 2.5 g / m.²It applied so that it might become. The back surface application was performed in the same manner as application sample 2. Thus, a coated sample 1 was prepared.
[0132]
(Surface protective layer coating solution)
Cellulose acetate butyrate 7.5g
2-butanone 80g
Methanol 10g
[0133]
(Evaluation of moisture content)
The polymer solution (or dispersion) used in the emulsion layer was coated on a glass plate and dried at 50 ° C. for 1 hour to prepare a polymer model film having a thickness of 100 μm (two or more kinds of polymers were bonded to the emulsion layer). The polymer was mixed in that ratio). After that, the polymer model film is peeled off from the glass plate and left for 3 days under the condition of 25 ° C. and 60% RH.₁ ) Was measured. Next, the polymer model membrane is left in a vacuum for 3 days and then quickly put into a weighing bottle with a known weight (W₀ = W_Three -W₂ ) Was measured. However, W_Three Is the weight of the polymer model membrane and weighing bottle, W₂ Is the weight of the weighing bottle. W₀ , W₁ The water content was calculated by the following formula.
[0134]
Equilibrium moisture content = {(W₁ -W₀ ) / W₀ } × 100 (%)
[0135]
(Evaluation of photographic performance)
 After exposing the photosensitive material at an angle of 30 degrees to the normal line with a 647 nm Kr laser sensitometer (maximum output 500 mW), the coated sample is developed at 120 ° C. for 20 seconds, and the resulting image is evaluated by a densitometer It went by. The measurement results were evaluated by Dmin. And sensitivity (the reciprocal of the ratio of the exposure amount giving a density 1.0 higher than Dmin.). The sensitivity was expressed as a relative evaluation with the sensitivity of the coated sample 2 as 100.
[0136]
(Evaluation of natural storage stability)
Each coated sample was cut into 30.5 cm × 25.4 cm, and the corner was a 0.5 cm round corner. Each of these samples is allowed to stand at 25 ° C and 50% RH for one day, and each photosensitive material is sealed in a bag made of moisture-proof material, and further 35.1cm x 26.9cm x 3.0cm makeup. It was put in a box and aged for 5 days at 50 ° C. (forced aging). This sample was processed in the same manner as the evaluation of photographic performance, and Dmin. Was evaluated.
[0137]
(Surface evaluation)
The surface condition of each coated sample was evaluated from the following viewpoints.
○: Practically acceptable.
X: The surface condition is not good.
[0138]
(Silver tone evaluation)
The color tone of the highest density portion of the coated sample evaluated for photographic performance was evaluated.
[0139]
The results are shown in Table 1. For coating sample 1, a coating sample was prepared using methyl ethyl ketone as the solvent for the reducing agent-containing coating layer.
[0140]
[Table 1]

[0141]
From Table 1, the coated sample in which the reducing agent is added in the form of a solid microcrystalline dispersion and the water content of the binder is 2 wt% or less has a good surface shape, excellent photographic performance, natural aging, and image color tone. It turns out that it is black. Moreover, although the coating sample 1 does not have the problem so much on the characteristic, since the organic solvent was used, it was difficult to handle a coating liquid.
[0142]
Example 2
(Preparation of colorant solid fine particle dispersion 1)
2 g of hydroxypropylcellulose and 93 g of water were added to 2.9 g and 2.1 g of the above color toning agents 1 and 2, respectively, and the mixture was well stirred and left for 10 hours. Thereafter, 168 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 10 hours with the same disperser used for the preparation of the reducing agent microcrystal dispersion. A solid fine particle dispersion 1 was obtained. As for the particle size, 70 wt% was 1.0 μm or less and 0.5 μm or more.
[0143]
(Preparation of colorant solid fine particle dispersion 2)
2.9 g and 2.1 g of the above color toning agents 1 and 2 were added to ethyl acetate and dissolved by stirring. A solution prepared by dissolving 1.6 g of polyvinyl alcohol in water was added, and the mixture was stirred at high speed with a homogenizer. Thereafter, all ethyl acetate was volatilized to obtain a solid fine particle dispersion 2 of the colorants 1 and 2. As for the particle size, 70 wt% of the particles were 1.0 μm or less and 0.5 μm or more.
[0144]
(Preparation of colorant solid fine particle dispersion 3)
2 g of hydroxypropylmethylcellulose and 88 g of water were added to 4.9 g, 3.6 g, and 1.5 g of the above color toning agent 1 and 2, and the color toning agent 3 having the following structure, respectively, and stirred well, and allowed to stand for 10 hours. Then, prepare 168g of zirconia beads with an average diameter of 0.5mm, put them in a vessel together with the slurry, and disperse for 10 hours with the same disperser used in the preparation of the colorant solid fine particle dispersion 1. Dispersion 3 was obtained. As for the particle size, 70 wt% was 1.0 μm or less and 0.5 μm or more.
[0145]
[Chemical 8]

[0146]
(Preparation of colorant solid fine particle dispersions 4 to 6)
Solid color particle dispersions 4 to 6 were prepared in the same manner as the color toner solid fine particle dispersion 3 separately from the above color toning agents 1, 2, and 3. The particle diameter is the same as that of dispersion 3.
[0147]
A coated sample was prepared in the same manner as in Example 1. However, as shown in Table 2, the color toning agent was added by using a solvent or by adding a solid fine particle dispersion. In the coated sample 24, the colorant solid fine particle dispersions 4 to 6 were mixed and added. As the reducing agent, reducing agent solid fine particle dispersion 1 was used.
[0148]
Evaluation similar to Example 1 was performed about the coating sample produced as mentioned above. The results are shown in Table 2. However, not only Dmin. But also the sensitivity was evaluated for the natural aging storage stability. The sensitivity is shown as a relative value with the sensitivity of the coated sample 15 before time taken as 100.
[0149]
[Table 2]

[0150]
From Table 2, it was found that, in the present invention, the use of the color toning agent as a solid fine particle dispersion has a high sensitivity and a very low desensitization of photographic properties over time. In particular, it has also been found that it is preferable to use two or more colorants as the same solid fine particle dispersion.
[0151]
Example 3
In the preparation of the silver halide grains prepared in Example 1, the following sensitizing dyes C and D were used in place of the sensitizing dyes A and B. Other than that, the silver halide grains were prepared in the same manner as in the preparation of the silver halide grains A. B was prepared and used in place of silver halide grain A. In addition, the photographic performance and the natural aging performance were evaluated using a laser sensitometer having a 820 nm diode instead of the sensitometer used in the evaluation of the photographic performance of Example 1. All others were evaluated in the same manner as in Example 1. As a result, the same tendency as in Example 1 was shown, and the effect of the present invention by adding the reducing agent as a solid fine particle dispersion was confirmed.
[0152]
[Chemical 9]

[0153]
Example 4
In Example 2, the sensitizing dye was changed to the sensitizing dyes C and D of Example 3, and evaluated in the same manner as in Example 3. As a result, the same tendency as in Example 2 was shown, and the effect of the present invention was confirmed.
[0154]
Example 5
In the coating sample 2 of Example 1, the colorants 1 and 2 were replaced with the solvent addition with methanol and added with the colorant solid fine particle dispersion 1. As a result, the surface condition and natural aging preservability were improved. It became an acceptable level.
[0155]
【The invention's effect】
According to the present invention, a photothermographic material which is excellent in photographic performance, improved in natural aging property and surface condition can be obtained. Moreover, since it becomes possible to prepare a coating solution that does not use an organic solvent, it is easy to handle and is preferable in terms of the working environment.

Claims (9)

In the photothermographic material having a photosensitive silver halide , a silver salt of a long-chain fatty carboxylic acid, a bisphenol reducing agent for silver ions, a colorant and a binder on a support, the reducing agent and / or the colorant A photothermographic material, wherein a polymer latex is used as a main binder of a layer containing a solid fine particle dispersion of the reducing agent and / or the toning agent as a solid fine particle dispersion.  2. The photothermographic material according to claim 1, wherein the polymer latex is a latex of a polymer having an equilibrium water content of 2 wt% or less at 25 ° C. and 60% RH.  3. The photothermographic material according to claim 1, wherein the layer containing the reducing agent and / or the color tone is formed by coating and drying using a coating solution in which 30 wt% or more of the solvent is water.  4. The photothermographic material according to claim 1, wherein at least the reducing agent is a solid fine particle dispersion.  The photothermographic material according to claim 1, wherein the reducing agent and the color toning agent are solid fine particle dispersions.  The photothermographic material according to claim 1, wherein a solid fine particle dispersion prepared by using two or more of the color tones and simultaneously forming two or more color tones into a solid fine particle dispersion is used.  The photothermographic material according to claim 1, wherein a polymer latex is used as a main binder of the layer containing the photosensitive silver halide.  8. The photothermographic material according to claim 7, wherein the polymer latex is a polymer latex having an equilibrium water content of 2 wt% or less at 25 ° C. and 60% RH.  9. The photothermographic material according to claim 1, wherein the layer containing the photosensitive silver halide is formed by coating and drying using a coating solution in which 30 wt% or more of the solvent is water.