JP2004113837A - Apparatus and method for manufacturing developer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method for manufacturing developer, by which a developer that applies an electrostatic charge satisfactorily and forms an excellent image having no scatter and no stain can efficiently be manufactured stably in a short time while making the inspecting/measuring frequency as low as possible. <P>SOLUTION: This apparatus 11 for manufacturing a two-component developer 22 by mixing toner with a carrier by agitation is characterized by being provided with a horizontal and cylindrical agitating/mixing vessel 20 having a raw material feeding port 24 and a developer discharging port 25, an agitation blade 23 fixed to a shaft 14 supported on both end walls of the vessel 20 to be rotated freely for imparting agitation force to the direction parallel to that of the shaft 14, at least three sensors 26 arranged on the inner wall of the vessel 20 for detecting the apparent magnetic permeability of the developer 22 and a control means for causing the blade 23 to agitate the toner with the carrier and the sensors 26 to continue detection of the magnetic permeability on the basis of the results detected by the sensors 26 until the developer 22 has the predetermined toner concentration. <P>COPYRIGHT: (C)2004,JPO

Description

【００３５】
上記式中Ｒ１は水素原子、炭素原子１〜４のアルキル基又はフェニル基、Ｒ２及びＲ３は水素基、炭素原子数１〜４のアルコキシ基、フェニル基、フェノキシ基、炭素原子数２〜４のアリケニル基、炭素原子数２〜４のアルケニルオキシ基、ヒドロキシ基、カルボキシル基、エチレンオキシド基、グリシジル基又は下記式で示される基である。
【００３６】
【化２】

【００３７】
上記式中Ｒ４，Ｒ５はヒドロキシ基、カルボキシル基、炭素原子数１〜４のアルキル基、炭素原子数１〜４のアルコキシ基、炭素原子数２〜４のアルケニル基、炭素原子数２〜４のアルケニルオキシ基、フェニル基、フェノキシ基、ｋ，ｌ，ｍ，ｎ，ｏ，ｐは１以上の整数を示す。
上記各置換基は未置換のもののほか、例えばアミノ基、ヒドロキシ基、カルボキシル基、メルカプト基、アルキル基、フェニル基、エチレンオキサイド基、グリシジル基、ハロゲン原子のような置換基を有してもよい。
【００３８】
また本発明で用いられるキャリアは、その体積固有抵抗を制御するために被覆層中に導電性付与材料を分散しても良い。分散される導電性材付与は従来より公知の物でよく、例えば鉄、金、銅等の金属；フェライト、マグネタイト等の酸化鉄；カーボンブラック等の顔料が挙げられる。
【００３９】
この中でも特にカーボンブラックの一つであるファーネスブラックとアセチレンブラックの混合物を用いることにより、少量の導電性微粉末の添加で効果的に導電性の調整が可能で、更に被覆層の耐摩耗性に優れたキャリアを得ることが可能となった。これらの導電性微粉末は、粒径０．０１〜１０μｍ程度のものが好ましく、被覆樹脂１００重量部に対して２〜３０重量部添加されることが好ましく、さらには５〜２０重量部が好ましい。
【００４０】
また、キャリア被覆層中には核体粒子との接着性を向上させたり導電性付与剤の分散性を向上させる目的でシランカップリング剤、チタンカップリング剤等を添加しても良い。
【００４１】
本発明で用いるシランカップリング剤としては下記一般式で示される化合物である。
【００４２】
【化３】
ＹＲＳｉＸ_３
【００４３】
但し、Ｘはけい素原子に結合している加水分解基でクロル基、アルコキシ基、アセトキシ基、アルキルアミノ基、プロペノキシ基などがある。
Ｙは有機マトリックスと反応する有機官能基でビニル基、メタクリル基、エポキシ基、グリシドキシ基、アミノ基、メルカプト基などがある。
Ｒは炭素数１〜２０のアルキル基又はアルキレン基である。
【００４４】
このシランカップリング剤の中でも、特に負帯電性を有する現像剤を得るにはＹにアミノ基を有するアミノシランカップリング剤が好ましく、正帯電性を有する現像剤を得るにはＹにエポキシ基を有するエポキシシランカップリング剤が好ましい。
【００４５】
被覆層の形成法としては、従来と同様、キャリア核体粒子の表面に被覆層形成液を噴霧法、浸漬法等の手段で塗布すればよい。
被覆層の厚さは０．１〜２０μｍが好ましい。
【００４６】
【実施例】
以下本発明を実施例により具体的に説明する。
【００４７】
トナーの製造例を以下に示す。
［製造例１］
スチレン−アクリル樹脂　　　　　　　　　　　　　　　　１００重量部
カーボンブラック　　　　　　　　　　　　　　　　　　　　　５重量部
ニグロシン染料　　　　　　　　　　　　　　　　　　　　　　３重量部
上記処方の混合物をヘンシェルミキサーにて混合後、１８０℃に設定した混練押し出し機によって混練した後、冷却固化せしめ、これをカッターミルにて粗粉砕後、機械式粉砕機を使用して微粉砕し、得られた微粉砕物を、コアンダ効果を利用した多分割分級機を使用してジェットミルで粉砕し、分級して平均１６μｍの母体粒子を得た。この母体粒子１００重量部に対して、疎水化処理されたコロイダルシリカ：０．３重量部、ステアリン酸亜鉛：０．２重量部を加え、ヘンシェルミキサーにて混合しトナー粒子ａを得た。
【００４８】
［製造例２］
ポリエステル樹脂　　　　　　　　　　　　　　　　　　　１００重量部
カーボンブラック　　　　　　　　　　　　　　　　　　　　　５重量部
含クロムアゾ染料　　　　　　　　　　　　　　　　　　　　　３重量部
上記処方の混合物をヘンシェルミキサーにて混合後、１５０℃に設定した混練押し出し機によって混練した後、冷却固化せしめ、これをハンマーミルにて粗粉砕後、機械式粉砕機を使用して微粉砕し、得られた微粉砕物をコアンダ効果を利用した多分割分級機を使用してジェットミルで粉砕し、分級して平均８μｍの母体粒子を得た。この母体粒子１００重量部に対して、疎水化処理されたコロイダルシリカ：０．３重量部、疎水化処理された酸化チタン：０．２重量部を加え、ヘンシェルミキサーにて混合しトナー粒子ａを得た。
【００４９】
キャリアの製造例を以下に示す。
［キャリア製造例１］
湿式法により作成したマグネタイト１００重量部に対してポリビニルアルコール２重量部、水６０重量部をボールミルに入れ１２時間混合してマグネタイトのスラリーを調整した。このスラリーをスプレードライヤーにて噴霧造粒し、平均粒径５４μｍの球形粒子とした。
この粒子を窒素雰囲気中で１０００℃の温度で３時間焼成後冷却し核体粒子１を得た。
シリコーン樹脂溶液　　　　　　　　　　　　　　　　　　１００重量部
トルエン　　　　　　　　　　　　　　　　　　　　　　　１００重量部
メチルトリメトキシシラン　　　　　　　　　　　　　　　　　６重量部
カーボンブラック　　　　　　　　　　　　　　　　　　　　１０重量部
上記混合物をホモミキサーで２０分間分散し、被覆層形成液１を調整した。
この被覆層形成液を流動床型コーティング装置を用いて核体粒子１を１０００重量部の表面にコーティングして、シリコーン樹脂被覆キャリアＡを得た。
このキャリア粒子の特性は以下の通りであった。
平均粒子径　：５８μｍ
飽和磁化　　：６５ｅｍｕ／ｇ
【００５０】
［キャリア製造例２］
ＣｕＯ：２４ｍｏｌ％、ＺｎＯ：２５ｍｏｌ％、Ｆｅ_２Ｏ_３：５１ｍｏｌ％に水を加え、湿式ボールミルにて１２時間粉砕混合し、スラリーを得た。このスラリーを乾燥し粉砕した後１０００℃の温度で仮焼成を行った。仮焼成後さらに湿式ボールミルにて１０時間粉砕し、分散剤及びバインダーを加えて、次いでスプレードライヤーにより造粒、乾燥し、電気炉にて１１００℃で３時間焼成した後、粉砕し、さらに分級して、平均粒径５１μｍの核体粒子２を得た。この核体粒子に対して、製造例１４と同様の方法で被覆層を形成し、キャリアＢを得た。
このキャリア粒子の特性は以下の通りであった。
平均粒子径　：５５μｍ
飽和磁化　　：５１ｅｍｕ／ｇ
【００５１】
［キャリア製造例３］
軟鋼屑を一次粉砕した後，油焼，選鉱等の工程を経た後，窒化処理して脆い一次粒子を形成する。この一次粒子を粉砕処理した後，分級して平均粒径が５３μｍの核体粒子３を得た。この核体粒子に対して、製造例１４と同様の方法で被覆層を形成し、キャリアＣを得た。
このキャリア粒子の特性は以下の通りであった。
平均粒子径　：５５μｍ
飽和磁化　　：１１７ｅｍｕ／ｇ
【００５２】
［実施例１］
製造例で作成されたキャリアＡ：１００重量部に対してトナーａ：４重量部をそれぞれ加え、図１に示す構成のレーディゲミキサーで攪拌／混合を繰り返し、前記したような制御を行い、二成分現像剤を得た。センサー電圧とトナー濃度の関係を図６及び表１に示す。
図６は、実際にサンプリングし計測したトナー濃度とセンサー制御によって得られたトナー濃度の比較グラフを示す。グラフ及び表１からわかるように、センサー制御によって制御されたトナー濃度と実測トナー濃度とほぼ同等のトナー濃度が達成できている。
【００５３】
【表１】

【００５４】
［実施例２］
製造例で作成されたキャリアＡ：１００重量部に対してトナーａを２重量部に変えた他は全て実施例１と同様にして、現像剤を得た。その結果を図７及び表２に示す。
グラフ及び表２からわかるように、トナー濃度設定値を２．０％に変更した条件も同様に実測濃度とほぼ同等レベルのトナー濃度を得ている。安定するまでの時間としては、１２〜１５分までの時間で安定している。高濃度設定条件に比べると、若干であるが早く安定化している。
【００５５】
【表２】

【００５６】
［比較例１］
製造例で作成されたキャリアＡ：１００重量部に対してトナーａを４重量部に変えセンサー検知をさせないで、通常のサンプリング方法でサンプリング／計測した他は全て同じ方法でそれぞれ加え、レーディゲミキサーで攪拌／混合を繰り返し現像剤を得た。
【００５７】
［比較例２］
製造例で作成されたキャリアＡ：１００重量部に対してトナーａを４重量部に変えセンサー検知をさせないで、通常のサンプリング方法でサンプリング／計測した他は全て同じ方法でそれぞれ加え、レーディゲミキサーで攪拌／混合を繰り返し現像剤を得た。
【００５８】
次に上記実施例で作成した現像剤を用いて（株）リコー製のＦＴ２２００に組み込み、画像出し試験を行い、画像濃度、地肌汚れ、キャリア現像、中間調再現性、画像濃度制御性を評価した。その結果を表３に示す。
【００５９】
【表３】

【００６０】
［試験］
（画像濃度、地肌汚れ）
画像の上部、中部、下部からそれぞれ３カ所、計９カ所の位置の画像濃度及び地肌汚れをマクベス反射濃度計で測定した。
（中間調再現性）
コダック社グレースケール（Ｎｏ．Ｑ−１３）を複写して階調可能な数を評価した。
評価基準は次の通りとした。
◎：１３以上
○：１０〜１２
△：　６〜　９
×：　５以下
（画像濃度制御性）
原稿濃度が１．６の１００％ソリッド画像を２０枚連続複写し、画像濃度の変化を評価した。
評価基準は次の通りとした。
◎：画像濃度差が０．１未満
○：　　　　　　０．１以上０．２未満
△：　　　　　　０．２以上０．５未満
×：　　　　　　０．５以上
【００６１】
【発明の効果】
本発明によれば、前記構成及び手法を採用したので、トナー濃度のばらつきがない安定した二成分現像剤が得られる。また、本発明によれば、攪拌混合容器内のトナー濃度を逐次センサーによって検知しているので、検査／計測頻度が減り、生産効率が上がる。
【図面の簡単な説明】
【図１】本発明による現像剤製造装置の一構成例を示す正面断面図である。
【図２】図１の装置の側面断面図及び正面断面図である。
【図３】センサー回路図である。
【図４】センサー電圧とトナー濃度の関係を示す図である。
【図５】センサー拡大図である。
【図６】実施例１におけるトナー濃度と混合時間の関係を示すグラフである。
【図７】実施例２におけるトナー濃度と混合時間の関係を示すグラフである。
【符号の説明】
１１　現像剤製造装置
１２　基台
１３（１３ａ、１３ｂ）　支持部
１４　シャフト
１５　プーリー
１６　攪拌翼駆動モーター
１７　駆動軸
１８　プーリー
１９　回転ベルト
２０　攪拌混合容器
２１　両端面
２２　現像剤
２３（２３ａ、２３ｂ）　攪拌翼
２４　原料投入口
２５　排出口
２６（２６ａ、２６ｂ、２６ｃ）　センサー
２７　センサー保護エアーホース[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus and a method for manufacturing a developer used in an image forming method and apparatus using an electrophotographic method such as a copying machine, a printer, and a facsimile, and an electrostatic printing method.
[0002]
[Prior art]
Conventionally, as a method of developing an electrostatic latent image using toner, a two-component developing method represented by a magnetic brush developing method (see US Pat. No. 2,870,063 (Patent Document 1)) and a one-component developing method are known. It has been known.
[0003]
The dry two-component developer used in the two-component development method has fine toner particles on the surface of relatively large carrier particles, which are held by electric force generated by friction between the two particles. Then, the attraction force in the latent image direction on the toner particles due to the electric field formed by the electrostatic latent image overcomes the bonding force between the toner particles and the carrier particles, and the toner particles are attracted to and adhered to the electrostatic latent image and become electrostatically charged. The latent image is to be visualized. The developer is used repeatedly while replenishing the toner consumed by the development.
[0004]
Therefore, in this two-component developing method, it is necessary to keep the mixture ratio of toner and carrier (toner density) constant in order to obtain a stable image density, and it is necessary to mount a toner replenishing mechanism and a complicated toner density sensor for that purpose. For this reason, there is a disadvantage that the developing device becomes large in size and the operation mechanism becomes complicated.
[0005]
Further, in a developer manufacturing apparatus, the amount of toner taken in is different between a portion where the developer is active and a portion where the developer is not active, or a portion where the amount of the developer is large and a portion where the amount of the developer is small. As a result, the developer having a constant toner concentration cannot be supplied stably.
Therefore, at the time of production, it is necessary to frequently perform sampling from each part in the mixer and continue stirring / mixing until the toner concentration in the developer in each part becomes constant.
When such an operation is repeated, there is a problem that the production efficiency / inspection efficiency becomes very poor until the toner concentration in the developer is stabilized.
Therefore, a method capable of accurately measuring the mixed state has been proposed. For example, Japanese Patent Laying-Open No. 6-331542 (Patent Document 2) proposes a method of detecting the degree of the amount of light reflected by an optical fiber as a degree of mixing. However, in such a method, there is a problem that the measuring device is expensive and complicated, and the maintenance is difficult.
[0006]
[Patent Document 1]
U.S. Pat. No. 2,870,063
[Patent Document 2]
JP-A-6-331542
[0007]
[Problems to be solved by the invention]
The first object of the present invention is to solve the above-mentioned drawbacks. The first object of the present invention is to sufficiently charge the toner and obtain a good image free from toner scattering, background stain, and streak-like stain. An object of the present invention is to provide a developer manufacturing apparatus and a manufacturing method capable of manufacturing a developer that can be manufactured.
It is a second object of the present invention to provide a developer manufacturing apparatus and a manufacturing method capable of efficiently and stably manufacturing the developer.
Further, a third object of the present invention is to provide a developer manufacturing apparatus and a manufacturing method which enable manufacturing in a short time by minimizing inspection / measurement frequency.
[0008]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, completed the present invention.
That is, according to the present invention, the above problems are solved by the following technical means.
(1) In a developer producing apparatus for producing a two-component developer by stirring and mixing a toner and a carrier,
A stirring and mixing container having a material input port and a developer discharge port, having a tubular shape extending horizontally and having both ends closed, and for accommodating the toner and the carrier for stirring and mixing,
A stirring blade fixed to a shaft rotatably supported on both end walls of the stirring and mixing container, and applying a stirring force to the toner and the carrier in a direction parallel to the shaft;
At least three sensors installed on the inner wall surface of the stirring and mixing container and detecting an apparent magnetic permeability of the two-component developer being mixed;
Control means for repeating the stirring by the stirring blade and the detection by the sensor until the two-component developer being mixed reaches the set toner concentration based on the detection results of the three sensors. manufacturing device.
(2) The sensor is spaced apart in a direction parallel to the shaft so as to always contact the two-component developer being mixed, and further converts an apparent magnetic permeability detected by the sensor into a voltage value. The developer manufacturing apparatus according to the above (1), further comprising a detection unit.
(3) Air supply means for supplying air to the detection section of the sensor to protect the sensor when measurement is not performed, and the control means sets the reference voltage of the set toner concentration T0 to V0 and sets the reference voltage at each stirring / mixing time. The developer producing apparatus according to (1) or (2), wherein when the measured voltage of the sampled measured toner concentration T1 is V1, the stirring / mixing / stopping cycle is repeated in the following relationship.
V0 ≧ V1 攪拌 (stirring / mixing operation)
V0 = {V1 (stirring / mixing stop)
(4) In a developer manufacturing method of manufacturing a two-component developer by stirring and mixing a toner and a carrier,
A stirring and mixing container having a raw material input port and a developer discharge port and having a tubular shape extending in the horizontal direction and having both ends closed is charged for stirring and mixing the toner and the carrier,
With a stirring blade fixed to a shaft rotatably supported on both end walls of the stirring and mixing container, the toner and the carrier are subjected to stirring and mixing by applying a stirring force in a direction parallel to the shaft,
At least three sensors installed on the inner wall surface of the stirring and mixing container detect an apparent magnetic permeability of the two-component developer being mixed,
Developing the developer by repeating agitation by the agitating blade and detection by the sensor based on the detection results of the three sensors until the two-component developer being mixed reaches a set toner concentration; Production method.
(5) The sensor is spaced apart in a direction parallel to the shaft so as to always contact the two-component developer being mixed, and the apparent magnetic permeability detected by the sensor is converted into a voltage and controlled. The method for producing a developer according to the above (4), wherein the method is information.
(6) When the sensor is not measured, the sensor is protected by supplying air from its surroundings to the detection unit. When the reference voltage of the set toner concentration T0 is V0, the measured toner concentration sampled at each stirring / mixing time. The method for producing a developer according to the above (4) or (5), wherein when the measured voltage of T1 is V1, the stirring / mixing / stopping cycle is repeated in the following relationship.
V0 ≧ V1 攪拌 (stirring / mixing operation)
V0 = {V1 (stirring / mixing stop)
(7) The method for producing a developer according to any one of the above (4) to (6), wherein a developer having a magnetization of a carrier in a magnetic field of 1000 Oe: σc of 30 to 120 emu / g is produced. .
(8) The developer according to any one of (4) to (7) above, wherein a developer having a weight average particle diameter of the carrier of 20 to 100 μm and a volume average particle diameter of the toner of 5 to 15 μm is produced. Developer manufacturing method.
(9) The method for producing a developer according to any one of (4) to (8), wherein the developer has a weight ratio of the toner to the carrier of 1:99 to 20:80.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a front sectional view showing the structure of a developer manufacturing apparatus according to the present invention. Reference numeral 11 denotes a developer manufacturing apparatus having one configuration example according to the present invention. In the developer manufacturing apparatus 11, a pair of support portions 13a and 13b are spaced apart from each other on a base 12, and a through-hole (not shown) is provided at an appropriate upper portion thereof, and the through-hole is provided in the through-hole. A shaft 14 is rotatably mounted between the two support portions 13a and 13b by a well-known rotation assisting member such as a bearing mechanism. A pulley 15 is fixed to a shaft portion protruding leftward in the figure from the support portion 13a. Further, a drive shaft 17 of a stirring blade drive motor 16 protrudes through a through hole at an appropriate place below the support portion 13a, and a pulley 18 is fixedly provided at a tip end thereof. A rotating belt 19 is stretched between the pulley 15 and the pulley 18, and the driving force of the stirring blade drive motor 16 is transmitted through these, so that the shaft 14 can be driven to rotate.
[0010]
The stirring and mixing container 20 is turned upside down, and both end faces 21a and 21b have a closed shape, and a closed space for mixing and stirring the developer (toner and carrier) 22 is formed (FIG. 2). Through holes are formed in the center of both side surfaces 21a and 21b of the stirring and mixing container 20, and the shaft 14 passes through them. As illustrated, stirring blades 23a and 23b for mixing and stirring the developer 22 are attached to the shaft 14. As the stirring blades 23a and 23b, conventionally known various shapes can be adopted for efficient mixing and stirring of the developer 22. A raw material inlet 24 for supplying a raw material including toner and carrier to be mixed is provided on the upper side of the stirring and mixing container 20, and the manufactured developer 22 is discharged on the lower side of the stirring and mixing container 20. Outlet 25 is provided.
[0011]
As shown in FIGS. 1 and 2, three sensors 26a, 26b, and 26c are provided along the direction parallel to the shaft 14 on the inner wall of the cylindrical portion of the stirring and mixing vessel 20 at three positions, left, center, and right in the figure. It is installed at a distance. Of course, the number of sensors 26 may be four or more. The sensor 26 detects the toner concentration of the developer 22 via apparent magnetic permeability. Specifically, the toner density is converted into an apparent magnetic permeability by a sensor circuit as shown in FIG. 3 and converted into a voltage. Based on the detection signal, a control unit (using a personal computer or the like) based on the detection signal transmits the toner density. The control of repeating the stirring / mixing by the sensor 26 and the detection / measurement by the sensor 26 is performed. The sensor circuit has a configuration as shown in FIG. 3 and applies a magnetic field to the developer 22 in the stirring and mixing container 20 to detect an apparent magnetic permeability.
[0012]
Here, an example of the relationship between the detection voltage of the sensor 26 and the toner density is shown in FIG. The desired toner density differs depending on the model / process of the image forming apparatus, and a desired set toner density (= sensor reference voltage) for each model is set. In the example of FIG. 4, a relationship represented by the following equation is established.
(Equation 1)
Y = -0.6078X + 5.2192
(R = 0.9943)
For example, when the set value of the toner density is 4.0 ± 0.05%, the sensor voltage is controlled in a range of 1.92V to 2.10V.
The number of sensors 26 is provided at least at three points on the left, center, and right in order to suppress the dispersion of measured values in the stirring and mixing container 20, and until each sensor 26 reaches a desired toner concentration (reference voltage). Then, the stirring / mixing by the stirring blade 23 and the detection / measurement by the sensor 26 are repeated. The detection unit of the sensor 26 is protected by air supplied from the sensor protection air hose 27 during non-measurement to eliminate a detection error, and the air supply is stopped during detection. This is shown in FIG.
[0013]
Next, the operation of the developer manufacturing apparatus of this configuration example will be described.
The toner and the carrier, which are the raw materials of the two-component developer, are introduced into the mixing container 20 through the raw material introduction port 24. When the required amount is input, the drive motor 16 is operated, and its rotational force is transmitted to the shaft 17, the pulley 18, the belt 19, the pulley 15, and the shaft 14, and the stirring blade 23 is rotated to stir the developer 22. Mixing is performed. A control unit (not shown) controls the operation of the drive motor 16 and the measurement operation by the sensor 26. The sensor 26 measures the apparent magnetic permeability of the developer 22 at a predetermined mixing time, and the measured value is converted into a voltage value. You. When the sensor 26 detects, the supply of air from the sensor protection air hose 27 is stopped. When the voltage value of each sensor 26 reaches the reference voltage corresponding to the set toner concentration, the control unit (not shown) stops the operation of the drive motor 16 and thereby stops the stirring and mixing. On the other hand, when the voltage value of each sensor 26 does not reach the reference voltage corresponding to the set toner concentration, the drive motor 16 is operated to perform stirring and mixing. With the above operation, the two-component developer 22 having the set toner concentration can be stably obtained.
[0014]
Next, a preferred two-component developer produced by the developer producing apparatus or method of the present invention, and a carrier and a toner as raw materials thereof will be described.
[0015]
As the toner used in the present invention, a toner manufactured by a conventionally known method can be used. Specifically, after a mixture composed of a binder resin, a magnetic substance, a polarity control agent, and optional additives is melted and kneaded with a hot roll mill, the mixture is cooled and solidified, and the resulting mixture is pulverized and classified. It is obtained by mixing an external additive.
[0016]
As the binder resin, all known resins can be used. For example, a homopolymer of styrene such as polystyrene, poly-p-chlorostyrene and polyvinyltoluene and a substituted product thereof; a styrene-p-chlorostyrene copolymer, a styrene-vinyltoluene copolymer, and a styrene-vinylnaphthalene copolymer Styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, stalene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl Styrenes such as ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-isoprene copolymer, styrene-acrylonitrile-indene copolymer Shared weight Body: polyvinyl chloride, phenolic resin, natural modified phenolic resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin , Polyvinyl butyral, rosin, modified rosin, terpene resin, coumaroindene resin, aliphatic or aliphatic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax and the like can be used alone or in combination.
[0017]
In particular, in the heat and pressure fixing method, by using a polyester resin as the binder resin, a toner having excellent PVC mat fusion resistance and excellent resistance to offset to a hot roll can be obtained.
[0018]
When the pressure fixing method is used, for example, polyethylene, polypropylene, polymethylene, polyurethane elastomer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, ionomer resin, styrene-butadiene copolymer, styrene-isoprene copolymer Examples include polymers, linear saturated polyesters, and paraffin.
[0019]
It is preferable that the charge control agent is added to the toner particles internally or externally added to the toner particles. The charge control agent makes it possible to control the amount of charge optimally according to the development system.
[0020]
The polarity control agent used in the toner may be a conventionally known one, and the positive polarity control agent may be a modified product of nigrosine and a fatty acid metal salt; tributylbenzylammonium-1-hydroxy-4-naphthosulfonate; Quaternary ammonium salts such as butylammonium tetrafluoroborate; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide and dicyclohexyltin oxide; diorganotin borates such as dibutyltin borate, dioctyltin borate and dicyclohexyltin borate, alone or in combination of two types These can be used in combination. Among these, a polarity controlling agent such as a nigrosine compound or an organic quaternary ammonium salt is particularly preferably used.
[0021]
As the negative control agent, for example, an organic metal compound and a chelate compound are effective. Examples thereof include aluminum acetylacetonate, iron (II) acetylacetonate, and chromium 3,5-di-tert-butylsalicylate. Particularly, acetylacetone metal complexes, monoazo metal complexes, naphthoic acid or salicylic acid-based metal complexes, Salts are preferred, and salicylic acid metal complexes, monoazo metal complexes or salicylic acid metal salts are particularly preferred.
[0022]
The polarity controlling agent is preferably used in the form of fine particles, and specifically, a number average particle size of 3 μm or less.
[0023]
The amount of the polarity control agent used in the toner is determined by the type of the binder resin, the presence or absence of additives used as necessary, and the toner manufacturing method including the dispersion method, and is uniquely limited. However, it is preferably used in an amount of 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight, based on 100 parts by weight of the binder. If the amount is less than 0.1 part by weight, the amount of charge of the toner is insufficient, which is not practical. On the other hand, when the amount exceeds 20 parts by weight, the charge amount of the toner is too large, and the electrostatic attraction with the carrier is increased, so that the fluidity of the developer is reduced and the image density is reduced.
[0024]
Further, a colorant such as a pigment or a dye may be added to the toner used in the present invention as needed. As the pigment, for example, carbon black, aniline black, furnace black, lamp black and the like can be used as a black colorant. As a cyan coloring agent, for example, phthalocyanine blue, methylene blue, Victoria blue, methyl violet, aniline blue, ultramarine blue, and the like can be used. As the magenta coloring agent, for example, rhodamine 6G lake, dimethylquinacridone, watching red, rose bengal, rhodamine B, alizarin lake and the like can be used. As a yellow colorant, for example, chrome yellow, benzidine yellow, Hansa yellow, naphthol yellow, molybdenum orange, quinoline yellow, tartrazine, etc., the amount of use is 0.1 to 20 parts by weight per 100 parts by weight of the resin, Preferably, the addition amount is 2 to 10 parts by weight. Examples of the dye include azo dyes, anthraquinone dyes, xanthene dyes, methine dyes and the like, and 0.05 to 10 parts by weight, preferably 0.1 to 3 parts by weight, per 100 parts by weight of the resin. Amount is good.
[0025]
Further, it is preferable to use an additive in the toner used in the present invention in order to improve charge stability, developability, fluidity and durability. These additives include, for example, metal oxides such as cerium oxide, zirconium oxide, silicon oxide, titanium oxide, aluminum oxide, zinc oxide, antimony oxide, and tin oxide, and fine powders such as silicon carbide and silicon nitride. And cleaning aids such as resin fine particles such as fluorine resin fine particles, silicone resin fine particles, and acrylic resin fine particles, and metal soap-based lubricants such as zinc stearate, calcium stearate, aluminum stearate, and magnesium stearate. Can be Among these, silicon oxide and titanium oxide are preferable as the fluidity improver, and zinc stearate is preferable as the cleaning aid.
[0026]
The fluidity improver used in the present invention may be, if necessary, a silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, a silane coupling agent, a silane coupling agent having a functional group, and other organosilicon compounds. Or a combination of various treating agents.
[0027]
The toner used in the present invention may contain a release agent for the purpose of improving the releasability at the time of fixing. As the release agent, known products can be used. For example, low-molecular-weight polyethylene, low-molecular-weight polypropylene, microcrystalline wax, carnauba wax, sasol wax, paraffin wax, etc. are used in an amount of 0.1 to 10% by weight based on 100% by weight of the binder resin. Is preferably added to the magnetic toner.
[0028]
The carrier used in the present invention preferably has a saturation magnetization in a magnetic field of 1000 [Oe] of 30 to 120 [emu / g], more preferably 40 to 100 [emu / g]. In such a range, the developer can efficiently take in the toner at the time of taking in the toner, so that the image density can be prevented from lowering even when an image with a large amount of toner consumption is repeatedly copied. Further, since the magnetic binding force of the developer to the developing sleeve in the developing area is increased, the development of the carrier on the photoconductor is effectively prevented, and a good image is obtained.
[0029]
Further, the weight average particle diameter of the carrier is preferably 20 to 100 μm, more preferably 20 to 80 μm, and the volume average particle diameter of the toner is preferably 5 to 15 μm. Within such a range, when the developer is taken into the image forming apparatus, the developer can be prevented from detaching from the developing sleeve and adhering to the photoreceptor, and furthermore, the developer contributing to the development can be prevented. Since the toner holding ratio can be increased by reducing the particle size of the constituting carrier, sufficient image density and fine line reproducibility can be achieved even in a high-speed copying machine.
[0030]
Further, the weight ratio of the carrier to the toner is preferably from 1:99 to 20:80. Within such a range, the amount of toner contributing to the development in the development area is large, and the toner holding ratio can be increased, so that sufficient image density and fine line reproducibility can be achieved even in a high-speed copying machine.
[0031]
As the core particles of the carrier, conventionally known particles may be used, for example, ferromagnetic metals such as iron, cobalt, and nickel; alloys and compounds such as magnetite, hematite, and ferrite; composites of the ferromagnetic particles and a resin; Is mentioned.
[0032]
It is preferable that the surface of the carrier used in the present invention is coated with a resin for the purpose of further increasing the durability.
Examples of the resin forming the coating layer include polyolefin resins such as polyethylene, polypropylene, chlorinated polyethylene, and chlorosulfonated polyethylene; polystyrene, acrylic (eg, polymethyl methacrylate), polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, Polyvinyl and polyvinylidene resins such as polyvinyl chloride, polyvinyl carbazole, polyvinyl ether, and polybiliketone; vinyl chloride-vinyl acetate copolymers; silicone resins comprising organosiloxane bonds or modified products thereof (for example, alkyd resins, polyester resins, epoxy resins) Modified products by resin, polyurethane, etc.); polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroe Polyamides; polyesters; fluoroplastic Len and polyurethane; polycarbonates; - urea amino resins such as formaldehyde resins, epoxy resins and the like. Among these, silicone resins or modified products thereof, and fluorine resins, particularly silicone resins or modified products thereof are preferable in terms of preventing toner spent.
[0033]
As the silicone resin, any conventionally known silicone resin may be used, and examples thereof include straight silicone comprising only an organosiloxane bond represented by the following formula and silicone resins modified with alkyd, polyester, epoxy, urethane, and the like. Can be
[0034]
Embedded image

[0035]
In the above formula, R1 is a hydrogen atom, an alkyl group or a phenyl group having 1 to 4 carbon atoms, R2 and R3 are a hydrogen group, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, a phenoxy group, and a C2-4 It is an alkenyl group, an alkenyloxy group having 2 to 4 carbon atoms, a hydroxy group, a carboxyl group, an ethylene oxide group, a glycidyl group or a group represented by the following formula.
[0036]
Embedded image

[0037]
In the above formula, R4 and R5 are a hydroxy group, a carboxyl group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, An alkenyloxy group, a phenyl group, a phenoxy group, k, l, m, n, o, and p represent an integer of 1 or more.
Each of the above substituents may have a substituent such as an amino group, a hydroxy group, a carboxyl group, a mercapto group, an alkyl group, a phenyl group, an ethylene oxide group, a glycidyl group, and a halogen atom, in addition to unsubstituted ones. .
[0038]
In the carrier used in the present invention, a conductivity-imparting material may be dispersed in the coating layer to control its volume resistivity. The conductive material to be dispersed may be a conventionally known material, and examples thereof include metals such as iron, gold, and copper; iron oxides such as ferrite and magnetite; and pigments such as carbon black.
[0039]
Among them, in particular, by using a mixture of furnace black and acetylene black, which are one of carbon blacks, it is possible to effectively adjust the conductivity by adding a small amount of conductive fine powder, and further improve the wear resistance of the coating layer. It has become possible to obtain an excellent career. These conductive fine powders preferably have a particle size of about 0.01 to 10 μm, and are preferably added in an amount of 2 to 30 parts by weight, more preferably 5 to 20 parts by weight, based on 100 parts by weight of the coating resin. .
[0040]
In addition, a silane coupling agent, a titanium coupling agent, or the like may be added to the carrier coating layer for the purpose of improving the adhesion to the core particles or improving the dispersibility of the conductivity-imparting agent.
[0041]
The silane coupling agent used in the present invention is a compound represented by the following general formula.
[0042]
Embedded image
YRSix₃
[0043]
Here, X is a hydrolyzing group bonded to a silicon atom, and includes a chloro group, an alkoxy group, an acetoxy group, an alkylamino group, a propenoxy group and the like.
Y is an organic functional group that reacts with the organic matrix, such as a vinyl group, a methacryl group, an epoxy group, a glycidoxy group, an amino group, and a mercapto group.
R is an alkyl group or alkylene group having 1 to 20 carbon atoms.
[0044]
Among these silane coupling agents, an aminosilane coupling agent having an amino group in Y is preferable for obtaining a developer having a negative charge property, and an epoxy group is preferably used for obtaining a developer having a positive charge property. Epoxy silane coupling agents are preferred.
[0045]
As a method for forming the coating layer, a coating layer forming liquid may be applied to the surface of the carrier core particles by a method such as a spraying method and an immersion method, as in the related art.
The thickness of the coating layer is preferably from 0.1 to 20 μm.
[0046]
【Example】
Hereinafter, the present invention will be described specifically with reference to examples.
[0047]
An example of the production of a toner is shown below.
[Production Example 1]
Styrene-acrylic resin 100 parts by weight
5 parts by weight of carbon black
Nigrosine dye: 3 parts by weight
After mixing the mixture of the above formulation with a Henschel mixer, kneading with a kneading extruder set at 180 ° C., solidifying by cooling, coarsely pulverizing with a cutter mill, and finely pulverizing using a mechanical pulverizer. The obtained finely pulverized product was pulverized by a jet mill using a multi-part classifier utilizing the Coanda effect, and classified to obtain base particles having an average of 16 μm. To 100 parts by weight of the base particles, 0.3 parts by weight of hydrophobized colloidal silica and 0.2 parts by weight of zinc stearate were added and mixed with a Henschel mixer to obtain toner particles a.
[0048]
[Production Example 2]
100 parts by weight of polyester resin
5 parts by weight of carbon black
Chromium-containing azo dye 3 parts by weight
After mixing the mixture of the above formulation with a Henschel mixer, kneading with a kneading extruder set at 150 ° C., solidifying by cooling, coarsely pulverizing with a hammer mill, and finely pulverizing using a mechanical pulverizer. The obtained finely pulverized product was pulverized with a jet mill using a multi-part classifier utilizing the Coanda effect, and classified to obtain base particles having an average of 8 μm. 0.3 parts by weight of hydrophobized colloidal silica and 0.2 parts by weight of hydrophobized titanium oxide are added to 100 parts by weight of the base particles, and mixed with a Henschel mixer to form toner particles a. Obtained.
[0049]
An example of manufacturing a carrier is shown below.
[Carrier Production Example 1]
2 parts by weight of polyvinyl alcohol and 60 parts by weight of water were added to a ball mill with 100 parts by weight of magnetite prepared by a wet method and mixed for 12 hours to prepare a magnetite slurry. The slurry was spray-granulated with a spray dryer to obtain spherical particles having an average particle size of 54 μm.
The particles were fired in a nitrogen atmosphere at a temperature of 1000 ° C. for 3 hours and then cooled to obtain core particles 1.
Silicone resin solution 100 parts by weight
100 parts by weight of toluene
Methyltrimethoxysilane 6 parts by weight
Carbon black 10 parts by weight
The mixture was dispersed with a homomixer for 20 minutes to prepare a coating layer forming liquid 1.
The core layer particles 1 were coated on the surface of 1,000 parts by weight of the coating layer forming liquid using a fluidized bed type coating apparatus to obtain a silicone resin-coated carrier A.
The characteristics of the carrier particles were as follows.
Average particle size: 58 μm
Saturation magnetization: 65 emu / g
[0050]
[Carrier Production Example 2]
CuO: 24 mol%, ZnO: 25 mol%, Fe₂O₃: Water was added to 51 mol%, and the mixture was pulverized and mixed in a wet ball mill for 12 hours to obtain a slurry. The slurry was dried and pulverized, and then calcined at a temperature of 1000 ° C. After the calcination, the mixture was further pulverized by a wet ball mill for 10 hours, a dispersant and a binder were added, and the mixture was granulated and dried by a spray drier. Thus, core particles 2 having an average particle size of 51 μm were obtained. A coating layer was formed on the core particles in the same manner as in Production Example 14 to obtain Carrier B.
The characteristics of the carrier particles were as follows.
Average particle size: 55 μm
Saturation magnetization: 51 emu / g
[0051]
[Carrier Production Example 3]
After the mild steel scrap is first pulverized, it undergoes oil baking, beneficiation, and other processes, and is then subjected to nitriding treatment to form brittle primary particles. The primary particles were pulverized and classified to obtain core particles 3 having an average particle diameter of 53 μm. A coating layer was formed on the core particles in the same manner as in Production Example 14 to obtain Carrier C.
The characteristics of the carrier particles were as follows.
Average particle size: 55 μm
Saturation magnetization: 117 emu / g
[0052]
[Example 1]
4 parts by weight of the toner a was added to 100 parts by weight of the carrier A prepared in the production example, and the mixture was repeatedly stirred / mixed with a Loedige mixer having the configuration shown in FIG. A two-component developer was obtained. FIG. 6 and Table 1 show the relationship between the sensor voltage and the toner concentration.
FIG. 6 shows a comparison graph of the toner density actually sampled and measured and the toner density obtained by sensor control. As can be seen from the graph and Table 1, a toner density controlled by the sensor control and a toner density substantially equal to the measured toner density can be achieved.
[0053]
[Table 1]

[0054]
[Example 2]
A developer was obtained in the same manner as in Example 1 except that the toner a was changed to 2 parts by weight with respect to 100 parts by weight of the carrier A prepared in the production example. The results are shown in FIG.
As can be seen from the graph and Table 2, under the condition that the toner density set value was changed to 2.0%, a toner density substantially equal to the actually measured density was similarly obtained. The time until stabilization is stable in a time from 12 to 15 minutes. Compared to the high-concentration setting condition, it is stabilized slightly, but quickly.
[0055]
[Table 2]

[0056]
[Comparative Example 1]
Carrier A prepared in the production example: toner 100 was added to 100 parts by weight, toner a was changed to 4 parts by weight, and sensor detection was not performed. Stirring / mixing was repeated with a mixer to obtain a developer.
[0057]
[Comparative Example 2]
Carrier A prepared in the production example: toner 100 was added to 100 parts by weight, toner a was changed to 4 parts by weight, and sensor detection was not performed. Stirring / mixing was repeated with a mixer to obtain a developer.
[0058]
Next, the developer prepared in the above example was incorporated into an FT2200 manufactured by Ricoh Co., Ltd., and an image output test was performed to evaluate image density, background contamination, carrier development, halftone reproducibility, and image density controllability. . Table 3 shows the results.
[0059]
[Table 3]

[0060]
[test]
(Image density, background stain)
Image densities and background stains were measured at a total of 9 locations at three locations from the top, middle, and bottom of the image, respectively, using a Macbeth reflection densitometer.
(Halftone reproducibility)
A Kodak gray scale (No. Q-13) was copied to evaluate the number of possible gradations.
The evaluation criteria were as follows.
◎: 13 or more
：: 10 to 12
△: △ 6 ～ 9
×: less than $ 5
(Image density controllability)
Twenty sheets of a 100% solid image having an original density of 1.6 were continuously copied, and the change in image density was evaluated.
The evaluation criteria were as follows.
A: Image density difference is less than 0.1
: 0.1 or more and less than 0.2
Δ: Δ0.2 or more and less than 0.5
×: 0.5 or more
[0061]
【The invention's effect】
According to the present invention, since the above-described configuration and method are employed, a stable two-component developer having no variation in toner density can be obtained. Further, according to the present invention, since the toner concentration in the stirring and mixing container is sequentially detected by the sensor, the frequency of inspection / measurement is reduced, and the production efficiency is increased.
[Brief description of the drawings]
FIG. 1 is a front cross-sectional view showing one configuration example of a developer manufacturing apparatus according to the present invention.
FIG. 2 is a side sectional view and a front sectional view of the apparatus of FIG. 1;
FIG. 3 is a sensor circuit diagram.
FIG. 4 is a diagram illustrating a relationship between a sensor voltage and a toner density.
FIG. 5 is an enlarged view of a sensor.
FIG. 6 is a graph showing the relationship between toner concentration and mixing time in Example 1.
FIG. 7 is a graph showing the relationship between toner concentration and mixing time in Example 2.
[Explanation of symbols]
11 Developer manufacturing equipment
12 base
13 (13a, 13b) Support
14 shaft
15 pulley
16 stirring blade drive motor
17 drive shaft
18 pulley
19 rotating belt
20 mixing container
21mm both end faces
22 developer
23 (23a, 23b) stirring blade
24 material inlet
25mm outlet
26 (26a, 26b, 26c) Sensor
27 Sensor protection air hose

Claims (9)

In a developer manufacturing apparatus that manufactures a two-component developer by stirring and mixing a toner and a carrier,
A stirring and mixing container having a material input port and a developer discharge port, having a tubular shape extending horizontally and having both ends closed, and for accommodating the toner and the carrier for stirring and mixing,
A stirring blade fixed to a shaft rotatably supported on both end walls of the stirring and mixing container, and applying a stirring force to the toner and the carrier in a direction parallel to the shaft;
At least three sensors installed on the inner wall surface of the stirring and mixing container and detecting an apparent magnetic permeability of the two-component developer being mixed;
Control means for repeating the stirring by the stirring blade and the detection by the sensor until the two-component developer being mixed reaches the set toner concentration based on the detection results of the three sensors. manufacturing device. The sensor is spaced apart in a direction parallel to the shaft so as to always contact the two-component developer being mixed, and further includes measuring means for converting an apparent magnetic permeability detected by the sensor into a voltage value. The developer manufacturing apparatus according to claim 1, further comprising: Air supply means for supplying air to the detection unit of the sensor to protect it during non-measurement, wherein the control means performs sampling and measurement at each stirring / mixing time when the reference voltage of the set toner concentration T0 is V0. 3. The developer manufacturing apparatus according to claim 1, wherein when the measured voltage of the toner concentration T1 is V1, the stirring / mixing / stopping cycle is repeated in the following relationship.
V0 ≧ V1 (stirring / mixing operation)
V0 = V1 (stirring / mixing stopped) In a developer producing method for producing a two-component developer by stirring and mixing a toner and a carrier,
A stirring and mixing container having a raw material input port and a developer discharge port and having a tubular shape extending in the horizontal direction and having both ends closed is charged for stirring and mixing the toner and the carrier,
With a stirring blade fixed to a shaft rotatably supported on both end walls of the stirring and mixing container, the toner and the carrier are subjected to stirring and mixing by applying a stirring force in a direction parallel to the shaft,
At least three sensors installed on the inner wall surface of the stirring and mixing container detect the apparent magnetic permeability of the two-component developer being mixed,
Developing the developer by repeating agitation by the agitating blade and detection by the sensor based on the detection results of the three sensors until the two-component developer being mixed reaches a set toner concentration; Production method. The sensor is spaced apart in a direction parallel to the shaft so as to always contact the two-component developer being mixed, and converts the apparent magnetic permeability detected by the sensor into a voltage value to control information and The method for producing a developer according to claim 4, wherein: When the sensor is not measured, the sensor is protected by supplying air from its surroundings to the detection unit. When the reference voltage of the set toner concentration T0 is set to V0, the measured toner concentration T1 sampled at each stirring / mixing time is measured. 6. The method according to claim 4, wherein when the voltage is V1, the stirring / mixing / stopping cycle is repeated in the following relationship.
V0 ≧ V1 (stirring / mixing operation)
V0 = V1 (stirring / mixing stopped) The developer production method according to any one of claims 4 to 6, wherein the developer is produced in which the carrier has a magnetization σc of 30 to 120 emu / g in a magnetic field of 1000 Oe. 8. The method according to claim 4, wherein the developer has a weight average particle size of the carrier of 20 to 100 [mu] m and a volume average particle size of the toner of 5 to 15 [mu] m. The method according to any one of claims 4 to 8, wherein a developer having a weight ratio of the toner to the carrier of 1:99 to 20:80 is manufactured.

Images