JPS60127232A - Preparation of cadmium sulfide powder for electrophotography - Google Patents

Abstract

PURPOSE:To prepare CdS powder having improved durability and good quality of image, by blending CdS containing a specific amount of Cu with a flux, calcining the prepared blend at a temperature higher than the melting point of the flux, dispersing it into water. CONSTITUTION:CdS containing 4X10<-4>-10X10<-4>mol Cu based on 1mol CdS is blended with >=20wt% flux such as CdCl2, etc. and calcined at a temperature >=50 deg.C higher than the melting point of the flux. The prepared calcined blend is dispersed into water, mixed with Cu, and a Cd salt in the case of necessity, reacted with a sulfide such as Na2S, etc. or H2S, so that one layer of CdS layer having a different Cu content is precipitated on the surface of CdS. The prepared CdS is washed, preferably calcined again, to give CdS powder for electrophotography having improved durability and good quality of image.

Description

【発明の詳細な説明】 本発明は、電子写真用硫化カドミウム粉体の製造方法に
関するもので、特には、銅を高ドープさせた硫化カドミ
ウム表面に銅を適度な量を含む硫化カドミウムを更に一
層析出させることによシ耐久性にすぐれた、画質の良好
な硫化カドミウムを製造する方法を提供するものである
。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing cadmium sulfide powder for electrophotography, and in particular, the present invention relates to a method for producing cadmium sulfide powder for electrophotography. The present invention provides a method for producing cadmium sulfide with excellent durability and good image quality by precipitation.

電子写真用感光体に用いられる硫化カドミウム粉体の製
造方法として実用化されている一方法に（１） おいては、銅等の不純物元素を含むカドミウム水溶液中
にＨ２８ガスを吹き込み硫化カドミウムを沈澱させた後
ＣｄＣｔ２などの融剤を添加し、粉体の粒成長、結晶性
の向上などを行っている。特に融剤量が該硫化カドミウ
ム粉体の２０重量ＪＲ−セント以上でアシ、かつ焼成温
度が融剤の融点よ９５０℃以上の焼成では硫化カドミウ
ム粉体の形状が著しく挙純化されかつ高結晶性のものが
得られ、これを用いた電子写真用感光体は優れた特性を
示す。In method (1), which has been put into practical use as a manufacturing method for cadmium sulfide powder used in electrophotographic photoreceptors, H28 gas is blown into a cadmium aqueous solution containing impurity elements such as copper to precipitate cadmium sulfide. After this, a fluxing agent such as CdCt2 is added to increase grain growth and improve crystallinity of the powder. In particular, when the amount of flux is 20 cents or more by weight of the cadmium sulfide powder, and the firing temperature is 950°C or higher than the melting point of the flux, the shape of the cadmium sulfide powder becomes significantly purified and highly crystalline. An electrophotographic photoreceptor using this material exhibits excellent properties.

一方、高速複写機への適用等、今まで以上の耐久性を要
求された場合は、現在のタイプの硫化カドぽラムでは要
求を満たすことができない。この対策として、粒子の抵
抗を上げることが考えられ、簡便な方法としては銅の添
加量を増すことである。On the other hand, when greater durability than ever is required, such as when applied to high-speed copying machines, the current type of cadoporum sulfide cannot meet the requirements. As a countermeasure to this problem, it is possible to increase the resistance of the particles, and a simple method is to increase the amount of copper added.

しかし添加量を増やすと、耐久性は向上するが、銅を多
量に添加した場合の特性劣化すなもち、表面電位の低下
、発生したキャリアー移動の阻害に基づく感度低下など
が現われ、画像上には画像濃度の低下、カゾリなどを生
ずる。However, when the amount of copper added increases, durability improves, but there is no deterioration in characteristics when adding a large amount of copper, a decrease in surface potential, and a decrease in sensitivity due to the inhibition of carrier movement that occurs. causes a decrease in image density, blurring, etc.

一般的に電子写真特性は、硫化カドミウム粒子（ｑ　） の表面状態、すなわち、表面近傍に存在する不純物濃度
によってｅマホ決定される。又、粒子の表面近傍よシ深
い層、すなわち、粒子のバルク（ｂ＋１ｌｋ）の抵抗が
耐久性と関連しておυ、抵抗を高くすると、耐久性は向
上する。このため、粒子のバルクの抵抗を高くし、表面
層の抵抗を適度に調節すれば、耐久性を向上させると共
に、他の特性に悪影響を及はさないことが予測される。In general, electrophotographic characteristics are determined by the surface condition of cadmium sulfide particles (q), that is, the concentration of impurities present near the surface. Furthermore, the resistance of the deep layer near the surface of the particle, that is, the bulk (b+1lk) of the particle, is related to durability, and as the resistance is increased, the durability is improved. Therefore, it is predicted that by increasing the bulk resistance of the particles and appropriately adjusting the resistance of the surface layer, durability will be improved and other properties will not be adversely affected.

本発明は以上の点を考慮して、バルクでの銅濃度を高く
保ちながら、表面層の銅濃度を最適な濃度とする方法を
提供するものである。The present invention takes the above points into consideration and provides a method for optimally adjusting the copper concentration in the surface layer while maintaining the bulk copper concentration high.

本発明の方法は、銅を高ドープさせた硫化カドミウムに
対して、２０重重量以上の融剤を添加し、融剤の融点よ
りも５０℃以上高い′温度で焼成し、該焼成物を水に分
散させ、適度な量の銅を加えた後、硫化物を添加し、該
硫化カドミウムの表面に、銅含有量の異なる層を一層析
出させるものである。In the method of the present invention, a fluxing agent of 20 weight or more is added to cadmium sulfide heavily doped with copper, and the fired product is heated at a temperature of 50°C or more higher than the melting point of the fluxing agent. After adding an appropriate amount of copper, sulfide is added to deposit a layer with a different copper content on the surface of the cadmium sulfide.

この処理は第−焼成後ばかシでなく、より特性を改善す
るために行われる第２回り降の焼成（アニールと称す）
彼でも有効に効果を生ずるが、第−焼成後に行うと焼成
後の剰余の塩化カドミウムを使用するため経済的である
他、処理後特性の安定化を図るために、アニールを行う
ことが、有利である点などを考慮して第−焼成後は処理
を行うものである。This process is not just a process after the first firing, but a second round of firing (referred to as annealing) that is carried out to further improve the properties.
However, it is economical to use the surplus cadmium chloride after the firing, and it is also advantageous to perform annealing to stabilize the properties after the treatment. The process is carried out after the first firing in consideration of the following points.

耐久性を改良するのに必要な抵抗を得るためには処理さ
れる硫化カドミウム中には、ｌ　ｍｏｌｅ　に対して、
銅が４　Ｘ　１０”　ｍｏｌｅ以上１０ＸＩＯ−’　ｍ
ｏｌｅ以下程度含まれなければならない。１ｏｘｉｏ　
ｍｏｌｅ以上鋼が含まれている場合には更に一層沈澱析
出させても表面層による効果が現われに＜＜、又銅の多
い場合の特性を示す。In order to obtain the necessary resistance to improve durability, the cadmium sulfide that is treated contains, for l mole,
Copper is 4 x 10" mole or more 10XIO-' m
It must contain about ole or less. 1oxio
If more than a mole of steel is contained, even if it is further precipitated, the effect of the surface layer will not appear<<, and the characteristics will be exhibited when there is a large amount of copper.

析出される層中に含まれる銅の量は硫化カドミウム１　
ｍｏｌｅに対して、０゜５〜２．ＯＸｌ　（１ｍｏｌｅ
　の範囲から、所望の感度、形成される硫化カドミウム
粒子の粒径などを考慮して適宜選択決定するものである
。The amount of copper contained in the deposited layer is 1 cadmium sulfide.
0°5~2. OXl (1mole
It is selected from the range as appropriate, taking into consideration the desired sensitivity, the particle size of the cadmium sulfide particles to be formed, etc.

又、第−焼成後の硫化カドミウムは牟−１かつ、かなシ
その表面に平滑さを有しているが更に一層析出させるこ
とにより平滑さは更に良好となる。Further, the cadmium sulfide after the first firing has a smooth surface, but the smoothness becomes even better by further precipitation.

従って、感光体とした場合の塗面の平滑さも更に向上す
る。Therefore, the smoothness of the coated surface when used as a photoreceptor is further improved.

本発明における第２層形成反応においては、融剤の一成
分である塩化カドミウムを利用する。析出量は析出層の
特性が現われると同時に、析出される層によって粒径の
成長が大きくなシすぎない範囲を適宜選択するものであ
る。本発明は上記の如き条件を満たす範囲として処理さ
れる硫化カドミウムに対して、残存する塩化カドミウム
が好ましくは１０〜３０　ｍｏｌｅ　ｑ６含まれる状態
にすることである。In the second layer forming reaction in the present invention, cadmium chloride, which is one component of the fluxing agent, is used. The amount of precipitation is appropriately selected within a range where the characteristics of the precipitated layer are exhibited and at the same time the grain size does not grow too large depending on the layer to be deposited. In the present invention, the remaining cadmium chloride is preferably contained in an amount of 10 to 30 mole q6 relative to the cadmium sulfide that is treated so as to satisfy the above conditions.

粒径、および、不純物のドープを完全にするために、反
応は、カドミウム塩が完全に反応し終るまで行うことが
必要である。In order to perfect the particle size and impurity doping, it is necessary to carry out the reaction until the cadmium salt has completely reacted.

反応は、硫化水素を反応液中に吹き込むか、あるいは硫
化ナトリウム、硫化カリウム等を添加して行う。The reaction is carried out by blowing hydrogen sulfide into the reaction solution, or by adding sodium sulfide, potassium sulfide, etc.

反応温度は硫化カドイウムの表面に硫化カドミウム沈澱
を析出させる反応であるため、一般の反応相、厳密にコ
ントロールする必要はないが、再（５） 溶解反応を起させないため、および、硫化カドミウムが
均一に析出するために、４０〜６０℃の範囲で行うこと
が効果的である。Since the reaction temperature is a reaction that precipitates cadmium sulfide on the surface of cadmium sulfide, it is not necessary to strictly control the general reaction phase. It is effective to carry out the precipitation in the range of 40 to 60°C.

上記反応で得られた硫化カドミウムは洗浄した後、更に
再焼成を行うことで、特性は更に改良される。The properties of the cadmium sulfide obtained in the above reaction are further improved by washing and re-firing.

以下、本発明を実施例によって詳細に説明する。Hereinafter, the present invention will be explained in detail with reference to Examples.

実施例１ 銅をモル比６　Ｘ　１０”モル含む硫化カドミウム１０
０　ｇｒにＣｄＣｌ２を２０ｇとＮａ　Ｃ１を３０ｇ添
加し、よく混合した上で石英ルッダに充填し、５３０℃
で３０分焼成した。（なお、ＣｄＣｌ２とＮａＣｔの混
合融剤の融点は、状態図から、Ｃｄ　ＣＺ　２　”　２
Ｎａ　ＣＺの融点の４２６℃に相当する）この様にして
得られたＣｄＳの六方度は、１００ｅｓであシ、１万倍
の電子顕微鏡写真によれば粒子表面は非常に滑らかで、
六方晶形特有の形状を持ち、各粒子は、２〜５μの径の
一一粒子となっているのが認められた。焼成後、硫化カ
ドミウム塩に純水を加え、攪拌解体し該水溶液を反応容
器に移す。１．１　ＸＩ　０−”ｍｏｌｅ／ｌ／ｇＮ 硫酸銅水溶液を１０　ｍＡ加えた後純水を加えて反応溶
液を１ｔとする。この溶液を５０℃に保ち、０、１　ｍ
ｏｌｅ／ｌの硫化ナトリウム溶液を２０　ｍｔ／ｍｉｎ
の流量で５５分間滴下反応を終了させた。反応後、上澄
み液の電導度が１０μｓ／α以下となるまで水洗を繰シ
返した後、６０℃で１晩乾燥した。乾燥後、４５０℃で
６０分間再焼成を行い、更に、洗浄液の上澄みが２０μ
ｓ／ｃｔｎ以下となるまで水洗を繰り返した後イオン交
換樹脂による残留イオン除去、乾燥した。とのＣｄＳを
塩化ビニル／酢酸ビニル共重合体中に分散させた後アル
ミニウム基板上に４０μの厚さに塗布乾燥させて得た感
光板に１５μ厚のぼりエステルフィルムをはルつけ三層
構成の感光体を得たところ、表面が非常に平滑であった
。Example 1 Cadmium 10 sulfide containing 6 x 10” moles of copper
Add 20g of CdCl2 and 30g of NaCl to 0gr, mix well, fill in quartz Rudda, and heat at 530℃.
Baked for 30 minutes. (In addition, from the phase diagram, the melting point of the mixed flux of CdCl2 and NaCt is Cd CZ 2 '' 2
The hexagonal degree of the CdS obtained in this way was 100 es (corresponding to the melting point of NaCZ at 426°C), and according to an electron micrograph at 10,000 times the particle surface was very smooth.
It was observed that the particles had a unique hexagonal crystal shape, and each particle was 11 particles with a diameter of 2 to 5 μm. After firing, pure water is added to the cadmium sulfide salt, the mixture is stirred and dissolved, and the aqueous solution is transferred to a reaction vessel. 1.1 XI 0-"mole/l/gN After adding 10 mA of copper sulfate aqueous solution, add pure water to make the reaction solution 1 t. Keep this solution at 50°C,
ole/l sodium sulfide solution at 20 mt/min
The dropping reaction was completed at a flow rate of 55 minutes. After the reaction, water washing was repeated until the conductivity of the supernatant became 10 μs/α or less, and then dried at 60° C. overnight. After drying, re-baking at 450℃ for 60 minutes, and further remove the supernatant of the cleaning solution by 20 μm.
After repeated washing with water until the temperature became s/ctn or less, residual ions were removed using an ion exchange resin, and the sample was dried. After dispersing CdS in a vinyl chloride/vinyl acetate copolymer, it was coated on an aluminum substrate to a thickness of 40 μm and dried, and then a 15 μm thick ester film was pasted on the resulting photosensitive plate to create a three-layered photosensitive plate. When the body was obtained, the surface was very smooth.

実施例２ 銅をモル比８×１０　モル含む硫化カドミウム１００　
ｇｒに、ＣａＣｌ２を４２　ｇｒ　、　Ｎ＆Ｃｔを８　
ｇｒ　添加し、実施例１と同様の方法で焼成を行った。Example 2 Cadmium sulfide 100 containing copper at a molar ratio of 8 x 10 moles
gr, 42 gr of CaCl2, 8 gr of N&Ct
gr was added, and firing was performed in the same manner as in Example 1.

焼成後の硫化カドオウム塊は、解体した後１．１Ｘ１０
ｍｏ　１　ｅ／ｌ　の硫酸銅水溶液を２１　ｍｌ加え、
更に純水を加えて１ｔとした後５５℃に温度を保ち、０
２Ｌ／ｍｌｎの流量で硫化水素を２６分間吹き込む。実
施例１と同様の方法で反応後の洗浄、再焼成を行い、硫
化カドミウムを作成し、更に実施例１と同様の方法で感
光体を作成した。After firing, the sulfurized Cadoum lump is 1.1X10 after being dismantled.
Add 21 ml of mo 1 e/l copper sulfate aqueous solution,
After adding pure water to make 1t, the temperature was maintained at 55℃ and the temperature was 0.
Hydrogen sulfide is blown in at a flow rate of 2 L/ml for 26 minutes. After the reaction, washing and re-baking were performed in the same manner as in Example 1 to produce cadmium sulfide, and a photoreceptor was further produced in the same manner as in Example 1.

比較例 銅をモル比１ＸＩＯ含む硫化カドミウム１００ｇｒにＣ
ａＣｌ２を４２　ｇｒ　、　ＮａＣ１を８ｇｒ添加、実
施例１と同様の方法で、焼成を行った。焼成後、硫化カ
ドオウムを水洗し、更に実施例１と同様の方法で再焼成
を行った。作成された硫化カドミウムは実施例１と同様
の方法で感光体とした。Comparative Example C: 100 gr of cadmium sulfide containing copper in molar ratio 1XIO
Firing was performed in the same manner as in Example 1, adding 42 gr of aCl2 and 8 gr of NaCl. After firing, the sulfurized kadoum was washed with water and further fired again in the same manner as in Example 1. The produced cadmium sulfide was used as a photoreceptor in the same manner as in Example 1.

実施例１．２および比較例の感光体を一次帯電、ＡＣ除
電同時露光、全面露光を基本プロセスとする複写機に適
用した所、下記のような特性が得られた。When the photoreceptors of Example 1.2 and Comparative Example were applied to a copying machine whose basic processes were primary charging, simultaneous exposure with AC static elimination, and full-surface exposure, the following characteristics were obtained.

更に１０万回プロセスを繰り返したところ、初期のコン
トラストに対してそれぞれ表のような保持率を示した。When the process was repeated 100,000 times, the retention rates shown in the table were obtained for each initial contrast.

すなわち、実施例１，２は初期特性が殆んど比較例と変
らないにもかかわらず、耐久性においては改良されてい
ることがわかる。That is, it can be seen that although the initial characteristics of Examples 1 and 2 are almost the same as those of the comparative example, the durability is improved.

（９）(9)

Claims (1)

【特許請求の範囲】[Claims] 硫化カドミウム１　ｍｏｌｅに対して銅を４×１０　〜
１０　Ｘ　１０−’　ｍｏｌｅ含む硫化カドミウムに２
０重量％以上の融剤を添加し、融剤の融点よ９５０℃以
上高い温度で焼成した後、該混合物を水に分散させ、銅
および必要に応じてカドミウム塩を加えた後、硫化物と
反応させることを特徴とする、硫化カドミウム粉体の製
造方法。4×10 ~ copper for 1 mole of cadmium sulfide
10 x 10-' mole of cadmium sulfide containing 2
After adding 0% by weight or more of a fluxing agent and firing at a temperature 950°C or more higher than the melting point of the fluxing agent, the mixture is dispersed in water, copper and optionally a cadmium salt are added, and then sulfide and cadmium salts are added. A method for producing cadmium sulfide powder, the method comprising reacting it.