JPS5967528A - Manufacture of photographic silver halide emulsion - Google Patents

Abstract

PURPOSE:To accelerate the reaction of silver halide emulsion particles with a coagulant and to prevent a reaction product after finishing the reaction from breaking by carrying out rapid stirring when the coagulant is added to the silver halide emulsion in a vessel and slow stirring during the coagulation of particles. CONSTITUTION:When a silver halide emulsion is desalted, the emulsion is mixed with a coagulant added to the emulsion in a mixing vessel by rapid stirring with a stirrer capable of applying uniform force to the emulsion all over the inside of the mixing vessel. The reaction of the coagulant with emulsion particles is accelerated. When particles of a reaction product are coagulated by collisin with one another after finishing the reaction, slow stirring is carried out so as to prevent the reaction product having weak bonding strength from breaking. Thus, an improved precipitated state is obtd. without increasing the amount of the coagulant harmful to photographic performance.

Description

【発明の詳細な説明】 この発明はハロゲン化銀写真乳剤の製造方法に係り、特
に脱塩工程における攪拌操作に特徴を有するものである
。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a silver halide photographic emulsion, and is particularly characterized by the stirring operation in the desalting step.

・・ロゲン化銀写真乳剤を製造するには調液とハロゲン
化アルカリ液をゼラチンの存在下で反応させてノ・ロゲ
ン化銀乳剤粒子を生成した後、その反応によって生じた
余分な塩を除去するという重要な工程かある。この脱塩
工程には一般にフロキュレーション法が採られている。To produce a silver halide photographic emulsion, a prepared solution and an alkali halide solution are reacted in the presence of gelatin to produce silver halide emulsion grains, and then excess salt produced by the reaction is removed. There is an important process of doing so. A flocculation method is generally adopted for this desalting step.

このフロキュレーション法はノ・ロゲン化銀乳剤中に適
当な凝集剤を添加し、ノ・ロケン化銀乳剤粒子をゼラチ
ンと共に凝集沈澱させ、塩を含む上澄液と分離するもの
である。しかして凝集剤添加時には凝集剤と乳剤粒子と
の反応促進のため、また添加終了後も反応生成物相互の
衝突による凝集を促進するために攪拌混合を行っている
。In this flocculation method, a suitable flocculant is added to a silver emulsion to coagulate and precipitate the silver emulsion grains together with gelatin, and the resulting grains are separated from a supernatant liquid containing salt. When the flocculant is added, stirring and mixing are performed to promote the reaction between the flocculant and the emulsion particles, and also after the addition is complete to promote aggregation due to mutual collision of the reaction products.

従来では上記攪拌混合は混合槽内に設けた一つの攪拌機
によシ行っていたが、乳剤粒子と凝集剤との反応は速く
、しかも乳剤粒子は凝集剤との反応基を多数持っている
ので、均一な反応を生じさせるためには攪拌様を急速に
回転させる必要かあった。このために、槽内の乳剤に与
える力のほとんどが攪拌機の近傍に集中したはかりでな
く、攪拌混合は前述の反応、凝集という過程の相違があ
るにも拘らず常に同−条件即ち同一の攪拌速度にて行わ
れていたので反応終了後、結合力の弱い反応生成物は攪
拌機の近傍において破壊され、凝集沈澱を速やかに行わ
せることかできないという問題があった。Conventionally, the above-mentioned stirring and mixing was performed using a single stirrer installed in the mixing tank, but the reaction between emulsion particles and flocculant is fast, and emulsion particles have many groups that react with the flocculant. However, it was necessary to rotate the stirrer rapidly in order to produce a homogeneous reaction. For this reason, most of the force applied to the emulsion in the tank is not concentrated near the stirrer, and stirring and mixing is always done under the same conditions, that is, under the same stirring conditions, despite the differences in the processes of reaction and aggregation mentioned above. Since the reaction was carried out at a high speed, after the reaction was completed, the reaction products with weak bonding strength were destroyed in the vicinity of the stirrer, and there was a problem that coagulation and precipitation could not be carried out quickly.

この発明は上記の問題を解消するためのもので、槽内の
ハロゲン化銀乳剤中に凝集剤を添加するに際し、その添
加時には急速攪拌を行い、粒子凝集時には緩速攪拌を行
うようにすることによって、乳剤粒子と凝集剤の反応を
促進するとともに、反応終了後の反応生成物を破壊させ
ることの々いノ・ロゲン化銀写真乳剤の製造方法を提供
することを目的としている。This invention is aimed at solving the above-mentioned problem.When adding a flocculant to a silver halide emulsion in a tank, rapid stirring is performed at the time of addition, and slow stirring is performed at the time of grain agglomeration. It is an object of the present invention to provide a method for producing a silver halogenide photographic emulsion, which promotes the reaction between emulsion grains and a flocculant, and which does not destroy the reaction product after the reaction is completed.

次に、この発明を実施例にもとづいて説明する。Next, the present invention will be explained based on examples.

ハロゲン化銀乳剤中よυ脱塩する場合、ます、混合槽内
の乳剤に凝集剤を添加する。この添加は従来同様、乳剤
の液表面にて行ってもよいか、望ましくは乳剤の深層部
、中層部９表層部の至るところに均等に分配する如くす
るとよい。乳剤とこれに添加された凝集剤との攪拌混合
は混合槽内の至るところで乳剤に与える力か均一にでき
る攪拌機例えは槽内の複数個所に撹拌機を分散設滌する
とか、翼径／槽径が０３〜０．９（従来の攪拌機は０３
未満である）の攪拌機を用いることが望ましいといえる
が、従来同様槽内に設けた一つの撹拌様にて攪拌混合す
るものであってもよい。When desalting a silver halide emulsion, a coagulant is added to the emulsion in a mixing tank. This addition may be carried out at the surface of the emulsion as in the past, or preferably it may be distributed evenly throughout the deep layer, middle layer 9 surface layer of the emulsion. Stirring and mixing of the emulsion and the flocculant added to it can be done using a stirrer that can uniformly apply force to the emulsion throughout the mixing tank. The diameter is 03 to 0.9 (the conventional stirrer is 03
It can be said that it is desirable to use a stirrer of less than 100 ml, but it is also possible to use a stirrer provided in the tank as in the conventional method for stirring and mixing.

この発明の特徴は前記凝集剤の添加時には乳剤を急速に
攪拌し、これによって凝集剤と乳剤粒子との反応を促進
する一方反応終了後、反応生成物相互の衝突による凝集
時には緩速に攪拌し、結合力の弱い反応生成物を破壊し
ないようにした点にある。The feature of this invention is that the emulsion is rapidly stirred when the flocculant is added, thereby promoting the reaction between the flocculant and the emulsion particles, while the emulsion is slowly stirred after the reaction is completed when the reaction products are flocculated due to mutual collision. , the point is that reaction products with weak bonding strength are not destroyed.

実施例 いま、この発明方法を実施した場合と従来法を実施した
場合において、凝集沈澱開始１０分後の上澄液乳剤濃度
を測定したところ次表の結果を得た。なお、次・表には
従来法を実施する際に凝集剤を４０係増量した場合をも
含めて比較している。EXAMPLE The concentration of the supernatant emulsion 10 minutes after the start of coagulation and precipitation was measured in the case where the method of this invention was carried out and in the case where the conventional method was carried out, and the results shown in the following table were obtained. In addition, the following table includes a comparison in which the amount of flocculant is increased by 40 times when implementing the conventional method.

上表のように、この発明方法によれは、従来法に比して
沈澱速度か速いものである。ところで沈澱しにくい乳剤
に対しては凝集剤を増量することで沈澱を生じさせるこ
とか可能であるが、従来法（攪拌速度一定）の場合でも
凝集剤を４０係増量すると上表の如く沈澱状態はかなシ
良くなる。ところか、本発明を適用すれは本来、写真性
能上有害である凝集剤を増量することなく、よシよい沈
澱状態が得られるというすぐわだ効果を奏する。As shown in the table above, the method of this invention has a faster precipitation rate than the conventional method. By the way, for emulsions that are difficult to precipitate, it is possible to cause precipitation by increasing the amount of flocculant, but even in the case of the conventional method (stirring speed is constant), if the amount of flocculant is increased by 40 parts, the precipitate state will occur as shown in the table above. It's fleeting and it gets better. On the other hand, the application of the present invention has the immediate effect that a good precipitation state can be obtained without increasing the amount of flocculant, which is originally harmful to photographic performance.

なお、この発明におりる掲′拌速度を単位体積当シの消
費動力で記すと、急速攪拌速度の場合は１．５Ｘ１０−
３〜２．　Ｏｘ　１０−”　（Ｋｇ・確・Ｓ　−１・１
−３）　　ｌ緩速攪拌速度の場合は５．０ｘｌＯ−５〜
５、ＯＸ　１０−’（Ｋｇ−ｃｎｔ　−Ｓ−”ＣＩｒＬ
−３）が好ましい操作範囲で、上表の結果はこの操作範
囲にて得られたものである。In addition, when the stirring speed mentioned in this invention is expressed in power consumption per unit volume, in the case of rapid stirring speed, it is 1.5X10-
3-2. Ox 10-” (Kg・Accurate・S-1・1
-3) 5.0xlO-5 for l slow stirring speed
5, OX 10-'(Kg-cnt-S-"CIrL
-3) is the preferred operating range, and the results in the table above were obtained within this operating range.

Claims (1)

【特許請求の範囲】[Claims] 槽内の７・ロゲン化銀乳剤中に凝集剤を添加するに際し
、その添加時には急速攪拌を行い、粒子凝集時には緩速
攪拌を行うことを特徴とするハロゲン化銀写真乳剤の製
造方法。7. A method for producing a silver halide photographic emulsion, which is characterized in that when adding a flocculant to a silver halide emulsion in a tank, rapid stirring is performed during the addition, and slow stirring is performed during grain aggregation.