JP2005013780A - Method and apparatus for manufacturing kneaded matter for use in manufacturing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus capable of manufacturing kneaded matter for use in manufacturing toner in a good kneaded state, high in productivity and having a merit capable of making the dispersibility of a colorant in the manufactured kneaded matter excellent, and a manufacturing method using it. <P>SOLUTION: This apparatus for manufacturing the kneaded matter is equipped with at least two rotatable open rolls each of which includes at least a heating roll and a cooling roll and constituted so that a raw material to be kneaded is supplied to the open rolls from the first ends thereof to be melted and kneaded by rotating the open rolls and the kneaded matter is discharged from the second ends of the open rolls. The distance D<SB>o</SB>between the second ends of the open rolls is large than the distance D<SB>1</SB>between the first ends of the open rolls. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００５８】
続いて、上記の混練原料を混練物製造装置により混練した。このとき利用した混練物製造装置の仕様及びその運転条件は以下のとおりである。
・混練物製造装置の仕様：
オープンロール型連続混練機 ［三井鉱山（株）製 商品名：ニーデックス］ ＭＯＳ１４０−８００型
ロール外径０．１４［ｍ］，有効ロール長０．８［ｍ］
両ロール間ギャップ ［供給側］ ０．０００１〜０．０００３［ｍ］ ［排出側］ ０．０００３［ｍ］
・運転条件：
高回転［加熱］ロール（前ロール）回転数７５回転／分
加熱媒体温度：［原料供給側］ ７５〜１３０℃ ［混練物排出側］ ６０℃
低回転［冷却］ロール（後ロール）回転数６０回転／分
冷却媒体温度：［原料供給側及び混練物排出側］ １５℃
混練原料の供給速度：７ｋｇ／時
【００５９】
上記の混練物製造装置により製造された混練物を粉砕、分級して、所望の粒度分布を有する電子写真用トナーを作製した。このトナーは、体積分布の５０％が平均粒径６．５μｍ程度の２成分現像用の非磁性マゼンタトナーであった。
【００６０】
この得られたトナーに外添剤（流動性付与剤）であるシリカを０．５３重量部の割合で混合して調製サンプルとした。この調製サンプルに平均粒径８５μｍのフェライトキャリア（パウダーテック社製）をＴ／Ｄ（デベロッパー［トナー＋キャリア］中のトナーの割合）＝４重量部で加えて混合し、実験用トナーを作製した。この実験用トナーを用いて、シャープ株式会社製デジタル複写機ＡＲ−Ｃ２８０で印字画像を作成した。
【００６１】
本実施例では、表２に示すように、オープンロールの排出側ギャップＤ_Ｏ、供給側ギャップＤ_Ｉ、加熱ロール３の供給側温度、製造トナーの処方番号１〜４を様々に設定して混練を行い、粉砕、分級の各工程を経て所望の粒度分布を有するトナーを製造した。
【００６２】
【表２】

【００６３】
表２の結着樹脂溶融温度Ｔｍについては、フローテスター［ＣＦＴ−５００，島津製作所（株）製］を用いて測定した。具体的には、ダイスの細孔の径１ｍｍ、長さ１ｍｍ、荷重２０ｋｇｆ、昇温速度６℃／分の測定条件で、１立方メートルの試料を溶融流出させた場合に、流出開始点から流出終了点の高さの１／２に相当する温度を、結着樹脂溶融温度Ｔｍとした。
表２に示す各実施例及び各比較例で得られた混練物の混練状態、並びにその混練物から製造されたトナーを用いた印字画像の状態を表３に示す。
【００６４】
【表３】

【００６５】
表３の光沢度については、日本電色工業社製のグロスメーターＶＧ−２０００を使用し、入射角７５°の条件で測定した。印字画像のトナー付着量は、０．５ｍｇ／ｃｍ^２とし、光沢度が１０以上の印字画像を良と判定した。
【００６６】
定着試験方法に関しては、トナー層の定着性は、紙への接着性とトナー層の溶融性に依存するので、印字紙上のトナー層の剥離性を測定する方法を取った。具体的には、図３に示すように、前記の複写機で作成した画像の印字面を中にして折り曲げた後、８５０ｇのローラを一定加圧になるように一往復転がすことにより荷重を与え、境界部分の折り曲げ部分を所定のはけで印字紙上のトナー層を５回こすり払い、このとき折り曲げ部分にできたライン幅ｌを目視で測定し、以下に示される４段階で判定した。
◎：幅ｌがかなり細く、また、薄く、トナー層がよく溶融し定着されている。
○：幅ｌが約０．３ｍｍ未満程度で微細線であり、切れ目がある。
△：幅ｌが約０．５ｍｍ程度で、細線がはっきりしている。
×：幅ｌがかなり乱れており、トナー層が定着されていない。
【００６７】
また、表３の総合評価については、上記の混練状態、光沢度、定着試験のそれぞれの結果を総合的に勘案して、それぞれ、○（良い）、△（普通）、×（悪い）の三段階で評価を行ったものである。
【００６８】
以下、表３に示されている結果について詳細に説明する。
表３の比較例１〜５を見ると、加熱ロール及び冷却ロール間の供給側と排出側とのギャップ比が１．２以下である場合には、予備混合物の供給量が増えたときに供給場所付近に滞留して排出側に移動せず、得られる混練物の量が減り、生産性が低下することが分かる。
【００６９】
一方、加熱ロール及び冷却ロール間の排出側におけるギャップが０．３ｍｍを越えたり、あるいは、供給側と排出側とのギャップ比が２．０以上であったりする場合には、両ロール間の隙間より落下する混合材料の量が多くなってしまい、オープンロールへ供給されたサンプルが混練されずに浪費されるため、得られる混練物の量が減り、生産性が低下することが分かる。また、結着樹脂と着色剤とが互いに十分に混練されない状態で排出側へ移動し、得られる混練物の質が低下してしまった。
【００７０】
以上より、両ロール間の排出側のギャップが０．３ｍｍ以下であり、加熱ロール及び冷却ロール間の排出側と供給側とのギャップ比が１．２〜２．０であることが望ましい。
【００７１】
また、比較例６より明らかな様に、加熱ロールの原料供給側温度が、Ｔｍ−３０℃未満（Ｔｍは、結着樹脂の溶融温度）ならば、加熱ロールの加熱による結着樹脂が十分に溶融されないため、供給サンプルの加熱ロールへの巻きつきが不良となり、その結果、印字画像の定着性が著しく悪かった。
以上より、加熱ロールの原料供給側温度が、Ｔｍ−３０℃以上で混練が行われる事が望ましい。
【００７２】
更に、比較例７より明らかな様に、少なくとも結着樹脂、着色剤を含有した混練原料に離型剤が加えられた場合（処方２）、加熱ロールの原料供給側温度が、Ｔｍ＋１０℃未満（Ｔｍは、結着樹脂の溶融温度）であると、供給サンプルが加熱ロールにうまく巻きつかず、ロール下へ滑り落ち、本実施例の条件下では、混練が不可能であった。
以上より、離型剤が加えられた場合は、加熱ロールの原料供給側温度が、Ｔｍ＋１０℃以上である事が望ましい。
【００７３】
更に、比較例８〜９より明らかな様に、ワックスは、溶融混練工程時の混練の精度より、５重量部以下にする事が望ましい（処方番号３、４）。これは、処方番号３、４の様にワックス添加量が５重量部を越えると、オープンロールの加熱ロールから供給サンプルが剥離しやすく、その結果、供給サンプルの混練の精度が著しく悪化してしまうためである。処方３、４の組成の混合物に関しては、オープンロールからの剥離が発生し、結着樹脂内での着色剤の分散性が悪かった。このため、得られた混練物によるトナーの印字画像も光沢度が低下し、良好でなかった。
【００７４】
以上、本発明のトナー製造に用いる混練物の製造装置及び製造方法について、具体的な実施の形態を示して説明したが、本発明はこれらに限定されるものではない。当業者であれば、本発明の要旨を逸脱しない範囲内において、上記各実施形態又は他の実施形態にかかる発明の構成及び機能に様々な変更・改良を加えることが可能である。
【００７５】
本発明の混練物製造装置及び製造方法は、例えば、１成分現像用のトナーや、磁性トナー等の製造にも応用可能である。また、混練物の製造に用いるオープンロール型連続混練機の型式についても、３本以上の互いに平行に並設されたロールや、ロールの一端の外径が、他端外径に比べて大きい円筒形状のロールなどを用いることもできる。
【００７６】
【発明の効果】
以上、説明したように、本発明のトナー製造に用いる混練物の製造装置及び製造方法によれば、以下に示すような効果が発揮される。
【００７７】
本発明によれば、少なくとも結着樹脂、着色剤を含有した混練原料を溶融混練する混練物製造装置及び製造方法において、溶融混練にオープンロール型連続混練機を用い、前記混合物を前記混練機へ供給し、前記混練機の互いに向かい合う各ロール間のギャップを、前記混合物の前記混練機への供給側から排出側に向かって徐々に広くなるように形成したことにより、供給された混練原料が供給側付近に滞留せずに排出側へ移動するので、前記混練機の加熱ロールに早く巻き付きやすくなり、混練原料の供給量が増加し、生産性が向上される。
【００７８】
また、本発明では、加熱ロールの排出側付近の温度を、供給側付近の温度より低くすることにより、加熱ロールに早く巻き付いた混練原料の混練時間が長くなり、混練原料がよく練れて混練状態が向上される。
【００７９】
以上のような本発明の特徴により、着色剤が微細化された状態で結着樹脂中に均一に分散し、得られた混練物によるトナーの印字画像の画質が向上するという効果が得られる。
【００８０】
また、本発明の混練物製造装置及び製造方法によれば、前記各ロール間の排出側におけるギャップをＤ_Ｏ、供給側におけるギャップをＤ_Ｉとしたとき、これらのギャップ比（Ｄ_Ｏ／Ｄ_Ｉ）が、１．２≦Ｄ_Ｏ／Ｄ_Ｉ≦２．０（ただし、Ｄ_Ｏ≦０．３ｍｍ）となるよう構成することにより、混練原料の供給量が増えても、混練原料が前記両ロールの隙間から下への落下するのを防ぎ、混練原料が混練工程に有効に利用できるため、得られる混練物が増加し、生産性が向上する。また、供給量が増えても、供給場所付近で混練原料が滞留する事なく、スムーズに排出側へ移動し、供給側と排出側とで前記両ロールによる混練原料への圧縮力の差が形成され、混練が効率よく行えるという効果が得られる。
【００８１】
また、本発明の混練物製造装置及び製造方法によれば、前記混練機の加熱ロールの原料供給側温度が、Ｔｍ−３０℃以上（Ｔｍは、結着樹脂の溶融温度）となるように調整することにより、加熱ロールの加熱で結着樹脂が溶融して加熱ロールに巻き付いた状態で混練が行われ、結着樹脂中に、着色剤が均一に分散し、光沢のある画像が得られるという効果が得られる。
【００８２】
また、本発明の混練物製造装置及び製造方法において、混練原料に離型剤を加えた場合には、前記混練機の加熱ロールの原料供給側温度が、Ｔｍ＋１０℃以上（Ｔｍは、結着樹脂の溶融温度）となるように調整することにより、加熱ロールの供給側付近で混練原料が加熱ロールから剥離するのを防ぎ、混練開始時の加熱ロールへの巻き付き不良が発生しないようにしている。また、離型剤の添加により、前記混練原料より得られた混練物は、離型性が良く、画像形成時の定着不良や、オフセットの発生を防止できるという効果が得られる。
【００８３】
また、本発明の混練物製造装置及び製造方法では、前記離型剤の添加量は前記混練原料の全体量に対して５重量％以下とすることにより、前記混練機に供給した混練原料の離型性が抑制され、原料供給側付近で、混練原料が、前記ロールから剥離しにくく、前記混練機の加熱ロールへの巻き付きも良好で長く混練できるため、混練状態が良くなる。
【００８４】
さらに、本発明の混練物製造装置及び製造方法により製造した混練物を用いて製造したトナーは、他の型式の混練機（例えば、二軸押出混練機など）により製造されたトナーと比較して、混練原料に大きな圧縮力が作用されているため、結着樹脂中で着色剤の分散性が良いトナーである。
【図面の簡単な説明】
【図１】本発明の混練物製造装置の全体構成を概略的に示す図である。
【図２】本発明の混練物製造装置のオープンロール部及びフィーダー部の上面図である。
【図３】本発明の混練物製造装置を用いて製造したトナーの定着試験を行う方法を示す図である。
【符号の説明】
１ ホッパ部
２ スクリュー部
３ 加熱ロール
４ 冷却ロール
６ ストリップカッター
７ 回収ボックス
８ 装置固定軸
９ ロール固定軸
Ｄ_Ｉ 供給側ギャップ
Ｄ_Ｏ 排出側ギャップ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and method for producing a recording toner used as a recording medium in a technique for forming an image on a recording medium by an electrophotographic process or an electrostatic printing process, and in particular, a raw material for toner production. It is related with the manufacturing apparatus and manufacturing method of kneaded material which become.
[0002]
[Prior art]
Conventionally, a pulverization method, a suspension polymerization method, an emulsion polymerization method and the like are well known as methods for producing a recording toner for electrophotography (hereinafter simply referred to as “toner”). Various methods have been devised, disclosed and implemented.
[0003]
As an example of a toner manufacturing method using a pulverization method, a method of manufacturing toner using an open roll type continuous kneader is known. In this method, generally, a binder resin (thermoplastic resin), a colorant (pigment), etc. are preliminarily mixed in advance using a mixer such as a mixer, and the raw material mixture obtained by this mixing is mixed. After melt kneading with an open roll, the kneaded product obtained there is pulverized and classified to obtain a toner having a desired particle size distribution.
Patent Document 1 discloses an open roll type continuous kneader used for producing a kneaded product for toner production.
[0004]
This open roll type continuous kneader is provided with a pair of open rolls, each open roll having a cylindrical shape, and facing each other so that gaps extending at regular intervals in the axial direction are provided between the open rolls. Thus, both ends of the bearing are rotatably supported by the bearings while extending in parallel.
[0005]
Each open roll is formed in a hollow shape, is formed so as to be able to supply a heat medium (refrigerant) such as water and oil, and is configured so that the outer surface temperature of each open roll can be arbitrarily adjusted. A feeder is installed above one end side of the open roll, and the raw material can be supplied from the feeder to one end of the open roll.
[0006]
In order to produce toner using this open roll type continuous kneader, first, a predetermined amount of each of binder resin, pigment and additive is weighed and then fed into the feeder, and the raw material is opened from the feeder feed port. Supply between one end of roll. Then, the raw material stays between one end supply sides of both open rolls to form a bank, and the raw material is swallowed into the bank by the rotation of the open roll in the bank to form convection.
[0007]
Further, in the bank, the binder resin swallowed by the convection is melted by heat generated by heating or kneading the open roll to become a fluid. The melted binder resin winds around the surface of the open roll, and the pigment and additive adhere to the binder resin, and is further kneaded into the binder resin while being transferred to the other end of the open roll. A kneaded product is prepared. The kneaded product is discharged from the other end discharge side of the open roll. The kneaded product is cooled and solidified, and then the kneaded product is pulverized, classified, and externally added to produce toner.
[0008]
With reference to FIGS. 1 to 4 of Patent Document 1, in this open roll type kneader, the gap width between both rolls arranged facing each other gradually becomes narrower from the supply side of the raw material mixture toward the discharge side. It is formed as follows. By forming the gap in this way, the compressive force acting on the raw material mixture from the roll increases from the supply side to the discharge side, and the dispersibility of the colorant and the like of the obtained kneaded product is improved. is there.
[0009]
[Patent Document 1]
JP 2002-229256 A
[Patent Document 2]
JP 2000-75548 A
[0010]
[Problems to be solved by the invention]
However, as in the open roll type continuous kneader described in Patent Document 1 above, when the gap width between both rolls arranged to face each other is gradually narrowed from the supply side of the raw material mixture toward the discharge side, Although the compressive force with respect to the raw material mixture is increased, there is a problem that when the supply amount of the raw material mixture is increased, the raw material mixture is retained in the vicinity of the supply side, and as a result, the productivity is lowered.
[0011]
The present invention has been made in view of the above problems, and is a kneaded product manufacturing apparatus and manufacturing method for toner production, which can manufacture a kneaded product in a good kneaded state, has high productivity, In addition, an object of the present invention is to provide a production apparatus and a production method having an advantage that the dispersibility of the colorant in the produced kneaded product is excellent.
[0012]
[Means for Solving the Problems]
As a result of diligent research in view of the above problems, the present inventor has found that in an open roll type continuous kneader used for toner production, the gap between the two rolls facing each other is relatively small on the supply side of the kneaded raw material, By making it relatively large on the discharge side, the kneading raw material stays in the vicinity of the roll supply side to improve productivity, and the dispersibility of the colorant in the binder resin and the kneading state of the entire kneading raw material I was able to improve.
[0013]
That is, the present invention includes two or more rotatable open rolls including at least a heating roll and a cooling roll, supplies a kneading raw material from the first end of the open roll, and melts and kneads it by rotation of the open roll. , A kneaded material manufacturing apparatus for discharging a kneaded material from the second end of the open roll, wherein a distance D between the second ends of the open rolls _O Is the distance D between the first ends of each open roll. _I The present invention provides a kneaded product manufacturing apparatus characterized by being larger than the above.
[0014]
Thus, the gap between the rolls facing each other of the open roll is formed so as to gradually widen from the supply side end of the kneading material toward the discharge side end, so that the supplied kneading material is near the supply side. Therefore, it is easy to wind around the heating roll quickly, the amount of the kneaded raw material is increased, and the productivity is improved.
[0015]
In the kneaded material manufacturing apparatus of the present invention, the distance D between the second ends of the open rolls _O And a distance D between the first ends of the open rolls _I Ratio D _O / D _I Is characterized by being 1.2 or more and 2.0 or less.
[0016]
By setting the gap ratio between the open rolls on the mixed raw material supply side and the kneaded product discharge side within the above range, even if the supply amount of the kneaded raw material increases, the kneaded raw material falls down from the gap between the two rolls. Therefore, the kneaded material can be effectively used in the kneading step, so that the obtained kneaded material is increased and the productivity is improved. Further, even if the supply amount of the kneaded material increases, the kneaded material moves smoothly to the discharge side without staying in the vicinity of the supply place, and the compressive force to the kneaded material by the both rolls on the supply side and the discharge side is increased. A difference is formed, and the effect that kneading can be performed efficiently is obtained.
[0017]
In the kneaded material manufacturing apparatus of the present invention, the heating roll is heated by a heating medium, and the cooling roll is cooled by a cooling medium.
In the kneaded material manufacturing apparatus according to the present invention, the heating roll has different temperatures near the first end and near the second end.
[0018]
In the kneaded material manufacturing apparatus of the present invention, the temperature near the first end of the heating roll is higher than the temperature near the second end of the heating roll.
[0019]
By setting the temperature in the vicinity of the discharge side of the heating roll lower than the temperature in the vicinity of the supply side, the kneading time of the kneading material wound around the heating roll becomes longer, the kneading material is well kneaded and the kneading state is improved. .
[0020]
In the kneaded material manufacturing apparatus of the present invention, when the melting temperature of the binder resin contained in the kneaded raw material is Tm, the temperature in the vicinity of the first end of the heating roll is (Tm-30) ° C. or higher. It is said.
[0021]
By setting the temperature in the vicinity of the raw material supply side of the heating roll to the above range, kneading is performed in a state where the binder resin is melted and heated around the previous roll by heating the heating roll, so that the obtained kneaded product is bonded. A colorant is uniformly dispersed in the resin, and a glossy image can be obtained by using a toner produced from this kneaded product.
[0022]
In the kneaded product manufacturing apparatus of the present invention, when the melting temperature of the binder resin contained in the mixed raw material containing the release agent is Tm, the temperature in the vicinity of the first end of the heating roll is (Tm + 10) ° C. or more. It is characterized by being.
[0023]
By adjusting the temperature near the raw material supply side of the heating roll to the above range, the kneading raw material is prevented from peeling off from the heating roll in the vicinity of the heating roll supply side, and the winding failure around the heating roll at the start of kneading is prevented. It does not occur. In addition, by adding a release agent, the kneaded material obtained from the kneading raw material has good releasability, and the effect of preventing poor fixing during image formation and occurrence of offset can be obtained.
[0024]
The kneaded material manufacturing apparatus of the present invention is characterized in that a spiral groove is formed on the surface of each open roll.
The present invention also relates to a method for producing a kneaded product using an open roll kneader equipped with at least a heating roll and a cooling roll, and a premixing step of mixing a kneading raw material containing at least a binder resin and a colorant; A kneading step of supplying the mixed kneading raw material to the first end of the open roll, rotating the open roll to knead, and discharging from the second end of the open roll as a kneaded product, Distance D between second ends _O Is the distance D between the first ends of each open roll. _I The present invention provides a method for producing a kneaded product characterized by being larger than the above.
[0025]
In this way, the gap between the rolls facing each other of the open roll is formed so as to gradually widen from the supply side end of the kneading raw material toward the discharge side end, so that the supplied kneading raw material is near the supply side. Therefore, it is easy to wind around the heating roll quickly, the amount of the kneaded raw material is increased, and the productivity is improved.
[0026]
In the method for producing a kneaded product of the present invention, the distance D between the second ends of the open rolls _O And a distance D between the first ends of the open rolls _I Ratio D _O / D _I Is characterized by being 1.2 or more and 2.0 or less.
[0027]
By setting the gap ratio between the open rolls on the mixed raw material supply side and the kneaded product discharge side within the above range, even if the supply amount of the kneaded raw material increases, the kneaded raw material falls down from the gap between the two rolls. Therefore, the kneaded material can be effectively used in the kneading step, so that the obtained kneaded material is increased and the productivity is improved. Further, even if the supply amount of the kneaded material increases, the kneaded material moves smoothly to the discharge side without staying in the vicinity of the supply place, and the compressive force to the kneaded material by the both rolls on the supply side and the discharge side is increased. A difference is formed, and the effect that kneading can be performed efficiently is obtained.
[0028]
In the method for producing a kneaded product of the present invention, the heating roll is heated by a heating medium, and the cooling roll is cooled by a cooling medium.
In the method for producing a kneaded product of the present invention, the heating roll is characterized in that it has different temperatures near the first end and near the second end.
[0029]
In the kneaded material manufacturing method of the present invention, the temperature in the vicinity of the first end of the heating roll is higher than the temperature in the vicinity of the second end of the heating roll.
[0030]
By setting the temperature in the vicinity of the discharge side of the heating roll lower than the temperature in the vicinity of the supply side, the kneading time of the kneading material wound around the heating roll becomes longer, the kneading material is well kneaded and the kneading state is improved. .
[0031]
In the method for producing a kneaded product of the present invention, when the melting temperature of the binder resin contained in the kneaded material is Tm, the temperature in the vicinity of the first end of the heating roll is (Tm-30) ° C. or higher. It is a feature.
[0032]
By setting the temperature in the vicinity of the raw material supply side of the heating roll to the above range, kneading is performed in a state where the binder resin is melted and heated around the previous roll by heating the heating roll. The colorant is uniformly dispersed in the resin, and a glossy image can be obtained by using the toner produced from this kneaded product.
[0033]
The method for producing a kneaded product of the present invention is characterized in that, in the preliminary mixing step, a kneading raw material contains 5% by weight or less of a release agent.
By making the amount of the release agent added to the kneading raw material 5% by weight or less with respect to the total amount of the kneading raw material, the releasability of the kneading raw material supplied to the open roll is suppressed, and the kneading raw material is supplied to the raw material. In the vicinity of the side, it is difficult to peel off from the roll, and the winding around the heating roll of the kneader is good and can be kneaded for a long time, so that the kneading state is improved.
[0034]
In the method for producing a kneaded product of the present invention, when the melting temperature of the binder resin contained in the mixed raw material containing the release agent is Tm, the temperature near the first end of the heating roll is (Tm + 10) ° C. It is characterized by the above.
[0035]
By adjusting the temperature near the raw material supply side of the heating roll to the above range, the kneading raw material is prevented from peeling off from the heating roll in the vicinity of the heating roll supply side, and the winding failure around the heating roll at the start of kneading is prevented. It does not occur. In addition, by adding a release agent, the kneaded material obtained from the kneading raw material has good releasability, and the effect of preventing poor fixing during image formation and occurrence of offset can be obtained.
[0036]
In the method for producing a kneaded product of the present invention, a spiral groove is formed on the surface of each open roll.
The present invention also includes a premixing step of mixing a kneading raw material containing at least a binder resin and a colorant, and an open roll kneading machine having an open roll having at least a heating roll and a cooling roll. Each open roll comprising: a kneading step of supplying to the first end, rotating and kneading the open roll, and discharging as a kneaded product from the second end of the open roll; and crushing and classifying the kneaded product The distance D between the second ends of _O Is the distance D between the first ends of each open roll. _I The present invention provides a method for producing a toner characterized by being larger than the above.
[0037]
The toner produced in this way has a greater compressive force applied to the kneaded material as compared with toner produced by other types of kneaders (for example, a twin screw extrusion kneader). A toner having good dispersibility of a colorant in a resin.
[0038]
According to the characteristics of the present invention as described above, an effect is obtained that the colorant is uniformly dispersed in the binder resin in a finely divided state, and the image quality of the printed image of the toner by the obtained kneaded material is improved.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
1 to 3 are diagrams illustrating embodiments of the present invention. In these drawings, the same reference numerals denote the same components, and the basic configuration and operation are the same. To do. Moreover, about what is not described among the components shown in FIGS. 1-3, it shall be the same as that of the conventional open roll type continuous kneading machine currently disclosed by patent document 1 and 2. FIG.
[0040]
FIG. 1 is a diagram schematically showing the overall configuration of the kneaded product production apparatus of the present invention.
The kneaded material manufacturing apparatus shown in FIG. 1 is an open roll type continuous kneader (hereinafter, abbreviated as “open roll”) having a pair of open rolls 3 and 4 facing each other. , A heating roll 3, a cooling roll 4, a strip cutter 6, and a collection box 7.
[0041]
The hopper unit 1 is for containing the raw material to be kneaded by this apparatus, and constitutes a table feeder (raw material supply mechanism) together with the screw unit 2.
Inside the screw part 2, a screw (not shown) extending spirally from the hopper part 1 side to the heating roll 3 and cooling roll 4 side is rotatably provided. The screw portion 2 communicates with the inside of the hopper portion 1 at one end, and the other end is disposed above the supply side ends (left side in FIG. 1) of the pair of heating rolls 3 and cooling rolls 4.
[0042]
The heating roll 3 and the cooling roll 4 are cylindrical rolls arranged close to each other in parallel, and spiral grooves a and b are formed on the respective surfaces. The heating roll 3 and the cooling roll 4 are configured to rotate in the directions indicated by the two arrows 5, that is, in directions opposite to each other.
[0043]
In addition, a heating medium such as oil can be passed through the heating roll 3, and a cooling medium such as water can be passed through the cooling roll 4, and the temperature of each roll surface can be adjusted. It is like that. This temperature adjustment function can be further adjusted so that the temperature is changed between the kneading raw material supply side and the kneaded material discharge side for each of the heating roll 3 and the cooling roll 4. The present invention is characterized in that the temperature of the heating roll 3 is relatively high on the kneaded material supply side and relatively low on the kneaded material discharge side.
[0044]
The strip cutter 6 is a disk-shaped metal strip cutter, is disposed near the end of the heating roll 3 on the kneaded product discharge side, and cuts the kneaded product wound around the heating roll 3.
The collection box 7 is a container for collecting the kneaded material cut by the strip cutter 6.
[0045]
FIG. 2 is a top view of the open roll part and the feeder part of the kneaded product manufacturing apparatus of the present invention.
In FIG. 2, a metal roll fixing shaft 9 penetrates the heating roll 3 and the cooling roll 4 in the length direction, and each roll fixing shaft 9 is made of a metal device fixing shaft at both ends. 8 is supported by a bearing. Each roll fixing shaft 9 is rotationally driven by a motor or the like (not shown), whereby the heating roll 3 and the cooling roll 4 are rotated in the inner direction (the direction indicated by the arrow 5 in FIG. 1). Will be able to.
[0046]
Here, the pair of roll fixing shafts 9 are arranged so as to be substantially V-shaped in a plane. Thereby, the gap (gap) between the heating roll 3 and the cooling roll 4 is configured to be small on the kneading raw material supply side and gradually increase toward the kneaded product discharge side. In FIG. 2, the gap on the kneading raw material supply side is D _I , The gap on the discharge side end of the kneaded material is D _O It is represented by
[0047]
Next, the process for producing a kneaded product from the kneaded material in the above-described kneaded product producing apparatus of the present invention will be described.
First, a predetermined amount of a binder resin, a colorant, and the like as kneading raw materials are weighed and put into a mixer such as a Q-type mixer or a Henschel mixer, and premixed under predetermined operating conditions. The obtained preliminary mixture is supplied to the hopper portion 1 of the table feeder as a kneading raw material.
[0048]
A kneading raw material made of a binder resin, a colorant, and the like housed in the hopper 1 is sent to the screw part 2, and the tip (close to the heating roll 3 and the cooling roll 4) by rotation of the helical screw in the screw part 2. Transported to the end) side. The kneading raw material that has reached the tip of the screw part 2 falls near the supply ends of the heating roll 3 and the cooling roll 4 located below, as indicated by an arrow 2-a in FIG.
[0049]
The kneading raw material supplied on the heating roll 3 and the cooling roll 4 temporarily stays in the vicinity of the dropping point, and then kneaded sequentially by the rotation of the rolls 3 and 4, and the surface temperature and kneading of the heating roll 3. It is heated and melted by friction or the like and wound around the heating roll 3. When the kneading raw material wound around the heating roll 3 is pressurized by both the rolls 3 and 4, the colorant is kneaded into the binder resin and kneaded.
[0050]
By continuously supplying the kneaded raw material on the supply side of the heating roll 3 and the cooling roll 4, the kneaded raw material wound around the heating roll 3 is sequentially pushed out toward the discharge side. When reaching the vicinity of the discharge side ends of the heating roll 3 and the cooling roll 4, the kneaded raw material wound around the heating roll 3 is cut by a disk-shaped metal strip cutter 6 and is indicated by an arrow 6-a in FIG. It is discharged in the direction and collected in the collection box 7 as a kneaded product.
[0051]
Thus, the kneaded material manufacturing apparatus of the present invention melts and kneads the kneaded raw material supplied to the supply side ends of the pair of open rolls by rotating the open rolls, and discharges them as a kneaded product from the discharge side ends. is there.
[0052]
In the kneaded product production apparatus of the present invention, as shown in FIG. 2, by making the gap between the heating roll 3 and the cooling roll 4 relatively small on the kneaded material supply side and relatively large on the kneaded material discharge side, The mixed raw material supplied on both rolls 3 and 4 moves to the discharge side without stagnation in the vicinity of the drop point, and wraps around the heating roll 3 quickly, so compared with the conventional open roll type kneader, The kneading capacity and productivity are improved.
[0053]
In the kneaded material manufacturing apparatus of the present invention, the temperature of the heating roll 3 is relatively high on the kneaded material supply side and relatively low on the kneaded material discharge side, so that the kneaded material wound around the heating roll 3 can be obtained. The kneading time becomes long, and the kneaded raw material is well kneaded to obtain a kneaded product in a good kneaded state. That is, a kneaded product is produced in which the colorant is finely dispersed and uniformly dispersed in the binder resin.
Thus, by using the kneaded material manufactured by the kneaded material manufacturing apparatus of the present invention, a toner with improved image quality of the printed image is manufactured.
[0054]
The gap D between the heating roll 3 and the cooling roll 4 on the kneading material supply side and the kneaded material discharge side, respectively. _I And D _O And the temperature of the heating roll 3 on each of the kneaded material supply side and the kneaded product discharge side is set to an appropriate value with reference to the examples shown below, thereby exhibiting the advantages of the present invention described above. Can do.
[0055]
【Example】
According to the above-described embodiment of the kneaded product production apparatus of the present invention, a mixture was produced, and a toner was produced using the mixture. The implementation method and results are shown below.
[0056]
First, as preliminary mixing, a predetermined amount of a binder resin and a colorant were weighed and introduced into a Q-type mixer, and preliminary mixing was performed to prepare a kneaded material.
The specifications and operating conditions of the Q-type mixer are as follows.
Q type mixer [Mitsui Mine Co., Ltd.] Q-20A / I (effective capacity: 20 liters)
・ Operating conditions: blade rotation speed 2000 rpm
・ Preliminary mixing time: 10 minutes
-Raw material input for premixing: 5.5kg
Here, four types of mixtures were used as kneading materials. Table 1 shows the composition of each mixture as formulations 1-4.
[0057]
[Table 1]

[0058]
Subsequently, the kneading raw material was kneaded with a kneaded material manufacturing apparatus. The specifications and operating conditions of the kneaded product manufacturing apparatus used at this time are as follows.
・ Specifications of the kneaded product manufacturing equipment:
Open roll type continuous kneader [Mitsui Mining Co., Ltd., trade name: Kneedex] MOS140-800 type
Roll outer diameter 0.14 [m], effective roll length 0.8 [m]
Gap between both rolls [supply side] 0.0001 to 0.0003 [m] [discharge side] 0.0003 [m]
・ Operating conditions:
High rotation [heating] roll (previous roll) rotational speed 75 rpm
Heating medium temperature: [Raw material supply side] 75 to 130 ° C. [Kneaded product discharge side] 60 ° C.
Low rotation [cooling] roll (rear roll) 60 rpm
Cooling medium temperature: [Raw material supply side and kneaded product discharge side] 15 ° C.
Feeding speed of kneaded raw material: 7 kg / hour
[0059]
The kneaded product produced by the kneaded product production apparatus was pulverized and classified to produce an electrophotographic toner having a desired particle size distribution. This toner was a non-magnetic magenta toner for two-component development in which 50% of the volume distribution had an average particle diameter of about 6.5 μm.
[0060]
The obtained toner was mixed with silica as an external additive (fluidity imparting agent) at a ratio of 0.53 parts by weight to prepare a prepared sample. To this prepared sample, a ferrite carrier (manufactured by Powdertech) having an average particle diameter of 85 μm was added and mixed at T / D (ratio of toner in developer [toner + carrier]) = 4 parts by weight to prepare an experimental toner. . Using this experimental toner, a printed image was created with a digital copier AR-C280 manufactured by Sharp Corporation.
[0061]
In this embodiment, as shown in Table 2, the discharge side gap D of the open roll _O , Supply side gap D _I Then, the supply temperature of the heating roll 3 and the prescription numbers 1 to 4 of the manufactured toner were variously set and kneaded, and a toner having a desired particle size distribution was manufactured through each step of pulverization and classification.
[0062]
[Table 2]

[0063]
The binder resin melting temperature Tm in Table 2 was measured using a flow tester [CFT-500, manufactured by Shimadzu Corporation]. Specifically, when a sample of 1 cubic meter is melted and flowed out under the measurement conditions of a 1 mm diameter, a length of 1 mm, a load of 20 kgf, and a heating rate of 6 ° C./min, the outflow ends from the outflow start point. A temperature corresponding to half the height of the point was defined as a binder resin melting temperature Tm.
Table 3 shows the kneaded state of the kneaded product obtained in each Example and each Comparative Example shown in Table 2, and the state of the printed image using the toner produced from the kneaded product.
[0064]
[Table 3]

[0065]
The glossiness in Table 3 was measured using a gloss meter VG-2000 manufactured by Nippon Denshoku Industries Co., Ltd. under an incident angle of 75 °. The toner adhesion amount of the printed image is 0.5 mg / cm ² A printed image having a glossiness of 10 or more was determined to be good.
[0066]
Regarding the fixing test method, since the fixability of the toner layer depends on the adhesiveness to paper and the meltability of the toner layer, a method of measuring the peelability of the toner layer on the printing paper was taken. Specifically, as shown in FIG. 3, after bending the printing surface of an image created by the above-mentioned copying machine, the load is applied by rolling the 850 g roller one reciprocally so as to be a constant pressure. Then, the toner layer on the printing paper was scraped off five times with a predetermined brush at the bent portion of the boundary portion, and the line width 1 formed at the bent portion at this time was visually measured and judged in the following four steps.
A: The width l is very thin and thin, and the toner layer is well melted and fixed.
○: The width l is less than about 0.3 mm, it is a fine line, and there is a break.
Δ: The width l is about 0.5 mm, and the fine line is clear.
X: The width l is considerably disturbed and the toner layer is not fixed.
[0067]
For the comprehensive evaluation in Table 3, the results of the kneading state, glossiness, and fixing test were comprehensively taken into consideration, and each of ◯ (good), △ (normal), and × (bad) was used. It was evaluated in stages.
[0068]
Hereinafter, the results shown in Table 3 will be described in detail.
Looking at Comparative Examples 1 to 5 in Table 3, when the gap ratio between the supply side and the discharge side between the heating roll and the cooling roll is 1.2 or less, the supply is made when the supply amount of the preliminary mixture is increased. It turns out that it stays in the vicinity of the place and does not move to the discharge side, the amount of the kneaded material obtained is reduced, and the productivity is lowered.
[0069]
On the other hand, when the gap on the discharge side between the heating roll and the cooling roll exceeds 0.3 mm, or the gap ratio between the supply side and the discharge side is 2.0 or more, the gap between both rolls It can be seen that the amount of the mixed material falling further increases, and the sample supplied to the open roll is wasted without being kneaded, so that the amount of the kneaded material obtained is reduced and the productivity is lowered. In addition, the binder resin and the colorant move to the discharge side in a state where they are not sufficiently kneaded with each other, and the quality of the obtained kneaded product has deteriorated.
[0070]
From the above, it is desirable that the gap on the discharge side between both rolls is 0.3 mm or less, and the gap ratio between the discharge side and the supply side between the heating roll and the cooling roll is 1.2 to 2.0.
[0071]
Further, as is clear from Comparative Example 6, if the temperature of the heating roll on the raw material supply side is less than Tm−30 ° C. (Tm is the melting temperature of the binder resin), the binder resin by heating of the heating roll is sufficient. Since it was not melted, the supply sample was not properly wound around the heating roll, and as a result, the fixability of the printed image was extremely poor.
From the above, it is desirable that the kneading is performed at a raw material supply side temperature of the heating roll of Tm-30 ° C or higher.
[0072]
Furthermore, as apparent from Comparative Example 7, when a release agent is added to the kneaded raw material containing at least a binder resin and a colorant (prescription 2), the raw material supply side temperature of the heating roll is less than Tm + 10 ° C. ( When Tm is the melting temperature of the binder resin), the supplied sample did not wind well around the heating roll, slipped down under the roll, and kneading was impossible under the conditions of this example.
As mentioned above, when a mold release agent is added, it is desirable that the raw material supply side temperature of a heating roll is Tm + 10 degreeC or more.
[0073]
Furthermore, as is clear from Comparative Examples 8 to 9, it is desirable that the wax be 5 parts by weight or less (prescription numbers 3 and 4) from the accuracy of kneading in the melt-kneading step. This is because when the added amount of wax exceeds 5 parts by weight as in the prescription numbers 3 and 4, the supply sample is easily peeled from the heating roll of the open roll, and as a result, the accuracy of the kneading of the supply sample is significantly deteriorated. Because. Regarding the mixture having the composition of Formulas 3 and 4, peeling from the open roll occurred, and the dispersibility of the colorant in the binder resin was poor. For this reason, the printed image of the toner with the obtained kneaded material was not good because the glossiness was lowered.
[0074]
As mentioned above, although the specific embodiment was shown and demonstrated about the manufacturing apparatus and manufacturing method of the kneaded material used for toner manufacture of this invention, this invention is not limited to these. A person skilled in the art can make various changes and improvements to the configurations and functions of the invention according to the above-described embodiments or other embodiments without departing from the gist of the present invention.
[0075]
The kneaded material production apparatus and production method of the present invention can be applied to the production of, for example, a toner for single component development and a magnetic toner. Also, for the type of open roll type continuous kneader used for the manufacture of the kneaded product, three or more rolls arranged in parallel with each other, or a cylinder in which the outer diameter of one end of the roll is larger than the outer diameter of the other end A shape roll or the like can also be used.
[0076]
【The invention's effect】
As described above, according to the kneaded product manufacturing apparatus and manufacturing method used for manufacturing the toner of the present invention, the following effects are exhibited.
[0077]
According to the present invention, in a kneaded material manufacturing apparatus and manufacturing method for melting and kneading a kneading raw material containing at least a binder resin and a colorant, an open roll continuous kneader is used for melt kneading, and the mixture is transferred to the kneader. The gap between the rolls facing each other of the kneading machine is formed so as to gradually widen from the supply side to the kneading machine of the mixture toward the discharge side, so that the supplied kneading raw material is supplied. Since it moves to the discharge side without staying in the vicinity of the side, it becomes easy to quickly wind around the heating roll of the kneading machine, the supply amount of the kneading material is increased, and the productivity is improved.
[0078]
Further, in the present invention, the temperature near the discharge side of the heating roll is lower than the temperature near the supply side, so that the kneading time of the kneading raw material wound around the heating roll becomes longer, and the kneading raw material is well kneaded and kneaded. Is improved.
[0079]
According to the characteristics of the present invention as described above, an effect is obtained that the colorant is uniformly dispersed in the binder resin in a finely divided state, and the image quality of the printed image of the toner by the obtained kneaded material is improved.
[0080]
Moreover, according to the kneaded material manufacturing apparatus and manufacturing method of the present invention, the gap on the discharge side between the rolls is set to D. _O , D on the supply side gap _I The gap ratio (D _O / D _I ) 1.2 ≦ D _O / D _I ≦ 2.0 (however, D _O ≦ 0.3 mm) prevents the kneading raw material from falling down from the gap between the two rolls even if the supply amount of the kneading raw material increases, and the kneading raw material is effectively used in the kneading process. Therefore, the obtained kneaded material increases and productivity improves. In addition, even if the supply amount increases, the kneaded raw material does not stay near the supply location, it moves smoothly to the discharge side, and a difference in compressive force on the kneaded raw material between the two rolls is formed on the supply side and discharge side Thus, the effect that kneading can be performed efficiently is obtained.
[0081]
Moreover, according to the kneaded material manufacturing apparatus and manufacturing method of this invention, it adjusts so that the raw material supply side temperature of the heating roll of the said kneader may be Tm-30 degreeC or more (Tm is the melting temperature of binder resin). By doing so, kneading is performed in a state where the binder resin is melted by the heating roll and wound around the heating roll, and the colorant is uniformly dispersed in the binder resin, so that a glossy image is obtained. An effect is obtained.
[0082]
In the kneaded product manufacturing apparatus and manufacturing method of the present invention, when a release agent is added to the kneaded raw material, the temperature of the raw material supply side of the heating roll of the kneader is Tm + 10 ° C. or higher (Tm is a binder resin) Is adjusted so that the kneading raw material is not peeled off from the heating roll in the vicinity of the supply side of the heating roll, and the winding failure around the heating roll at the start of kneading is prevented from occurring. In addition, by adding a release agent, the kneaded material obtained from the kneading raw material has good releasability, and the effect of preventing poor fixing during image formation and occurrence of offset can be obtained.
[0083]
Further, in the kneaded material production apparatus and method of the present invention, the amount of the release agent added is 5% by weight or less with respect to the total amount of the kneaded material, so that the kneaded material supplied to the kneader is separated. The moldability is suppressed, and the kneaded raw material is hardly peeled off from the roll in the vicinity of the raw material supply side, and the kneading around the heating roll of the kneader is good and can be kneaded for a long time.
[0084]
Furthermore, the toner manufactured using the kneaded product manufactured by the kneaded product manufacturing apparatus and manufacturing method of the present invention is compared with the toner manufactured by another type of kneader (for example, a twin screw extruder kneader). Since the kneading raw material is subjected to a large compressive force, the toner has good dispersibility of the colorant in the binder resin.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing the overall configuration of a kneaded product production apparatus of the present invention.
FIG. 2 is a top view of an open roll part and a feeder part of the kneaded product manufacturing apparatus of the present invention.
FIG. 3 is a diagram illustrating a method for performing a fixing test of a toner manufactured using the kneaded material manufacturing apparatus of the present invention.
[Explanation of symbols]
1 Hopper section
2 Screw part
3 Heating roll
4 Cooling roll
6 Strip cutter
7 Collection box
8 Equipment fixed shaft
9 Roll fixed shaft
D _I Supply side gap
D _O Discharge gap

Claims (18)

Comprising two or more rotatable open rolls including at least a heating roll and a cooling roll;
A kneaded material manufacturing apparatus for supplying a kneaded raw material from a first end of the open roll, melting and kneading by rotation of the open roll, and discharging a kneaded material from the second end of the open roll,
The kneaded material manufacturing apparatus, wherein a distance D _O between the second ends of the open rolls is greater than a distance D _I between the first ends of the open rolls. The ratio D _O / D _I between the distance D _O between the second ends of the open rolls and the distance D _I between the first ends of the open rolls is 1.2 or more and 2.0 or less. The kneaded material manufacturing apparatus according to claim 1. The kneaded product manufacturing apparatus according to claim 1 or 2, wherein the heating roll is heated by a heating medium, and the cooling roll is cooled by a cooling medium. The kneaded product manufacturing apparatus according to claim 3, wherein the heating roll has different temperatures in the vicinity of the first end and in the vicinity of the second end. The kneaded product manufacturing apparatus according to claim 4, wherein a temperature in the vicinity of the first end of the heating roll is higher than a temperature in the vicinity of the second end of the heating roll. The kneading according to claim 5, wherein when the melting temperature of the binder resin contained in the kneading raw material is Tm, the temperature in the vicinity of the first end of the heating roll is (Tm-30) ° C or higher. Product manufacturing equipment. When the melting temperature of the binder resin contained in the mixed raw material containing the release agent is Tm,
The kneaded product manufacturing apparatus according to claim 5, wherein the temperature in the vicinity of the first end of the heating roll is (Tm + 10) ° C or higher. The kneaded product manufacturing apparatus according to any one of claims 1 to 7, wherein a spiral groove is formed on each open roll surface. A method for producing a kneaded product using an open roll kneader equipped with at least a heating roll and a cooling roll,
A premixing step of mixing a kneading raw material containing at least a binder resin and a colorant;
A kneading step of supplying the mixed kneaded raw material to the first end of the open roll, rotating the open roll to knead, and discharging the kneaded material from the second end of the open roll;
The method for producing a kneaded product, wherein a distance D _O between the second ends of the open rolls is greater than a distance D _I between the first ends of the open rolls. The ratio D _O / D _I between the distance D _O between the second ends of the open rolls and the distance D _I between the first ends of the open rolls is 1.2 or more and 2.0 or less. The method for producing a kneaded product according to claim 9. The method for producing a kneaded product according to claim 9 or 10, wherein the heating roll is heated by a heating medium, and the cooling roll is cooled by a cooling medium. The method for producing a kneaded product according to claim 11, wherein the heating roll has different temperatures in the vicinity of the first end and in the vicinity of the second end. The method for producing a kneaded product according to claim 12, wherein the temperature in the vicinity of the first end of the heating roll is higher than the temperature in the vicinity of the second end of the heating roll. When the melting temperature of the binder resin contained in the kneaded raw material is Tm,
The temperature in the vicinity of the first end of the heating roll is (Tm-30) ° C. or higher, The method for producing a kneaded product according to claim 13. 14. The method for producing a kneaded product according to claim 13, wherein in the preliminary mixing step, 5% by weight or less of a release agent is included in the kneaded raw material. When the melting temperature of the binder resin contained in the mixed raw material containing the release agent is Tm,
The method for producing a kneaded product according to claim 15, wherein the temperature in the vicinity of the first end of the heating roll is (Tm + 10) ° C or higher. The method for producing a kneaded product according to any one of claims 9 to 16, wherein a spiral groove is formed on each open roll surface. A premixing step of mixing a kneading raw material containing at least a binder resin and a colorant;
The mixed kneading raw material is supplied to the first end of an open roll of an open roll kneading machine provided with at least a heating roll and a cooling roll, and the open roll is rotated and kneaded. A kneading step for discharging, and a step of pulverizing and classifying the kneaded product,
The toner manufacturing method, wherein a distance D _O between the second ends of the open rolls is larger than a distance D _I between the first ends of the open rolls.

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