JP4143485B2 - DEVELOPMENT CARRIER MANUFACTURING METHOD, DEVELOPING DEVICE, IMAGE FORMING DEVICE, AND PROCESS CARTRIDGE HAVING DEVELOPER CARRIER PRODUCED BY THIS MANUFACTURING METHOD - Google Patents

Description

【００２０】
実施例１〜２は、使用初期時から画像の濃度低下が確認された。これは、バリがスリーブに多く発生してしまい、このバリによって、現像剤の汲み上げが邪魔され、現像剤の搬送性が十分でなくなってしまったためと考えられる。
実施例３は、現像剤の搬送性に問題はなく、使用初期時には問題がなかったが、長期使用するにつれて、画像の乱れが確認された。これは、スリーブに付着したバリが剥離して感光体を傷つけてしまったため起こったと考えられる。
実施例４は、多少のバリは見られたものの、画像に影響を及ぼすことはなかった。また、実施例５は、バリの発生はほとんどなく画像に影響を及ぼすことはなかった。
【００２１】
以上の結果から、ビッカース硬度６０を越えると、現像装置に組み込んだ場合においても、実使用上問題のないレベルのバリの発生に抑ることができる。
【００２２】
図９は、本実施形態の加工方法によって作成された現像スリーブが搭載された画像形成装置の概略図である。この画像形成装置は、複写装置本体１００、この複写機本体を載せる給紙テーブル２００、複写装置本体上に取り付けるスキャナ３００、さらにその上に取り付ける原稿自動搬送装置（ＡＤＦ）４００から主に構成されている。
複写装置本体１００には、中央に、無端ベルト状の中間転写体１０を設ける。
【００２３】
そして、図９の例では、中間転写体１０を、３つの支持ローラ１４，１５，１６に掛け回して図中時計回り方向に回転搬送可能とする。
図示の例では、３つの支持ローラのうち第２の支持ローラ１５の左側に、画像転写後に中間転写体１０上に残留する残留トナーを除去する中間転写体クリーニング装置１７を設ける。また、第１の支持ローラ１４と第２の支持ローラ１５との間に張り渡した中間転写体１０上には、その搬送方向に沿って、ブラック，イエロー，マゼンタ，シアンの４つの画像形成手段１８を横に並べて配置してタンデム画像形成装置２０を構成する。そのタンデム画像形成装置２０の上方には、図１に示すように、露光装置２１を設ける。
【００２４】
一方、中間転写体１０を挟んでタンデム画像形成装置２０と反対の側には、２次転写装置２２を備える。２次転写装置２２は、図示の例では、２つのローラ２３間に、無端ベルトである２次転写ベルト２４を掛け渡して構成し、中間転写体１０を介して第３の支持ローラ１６に押し当てて配置し、中間転写体１０上の画像をシートに転写する。
また、２次転写装置２２の横には、シート上の転写画像を定着する定着装置２５を設ける。定着装置２５は、無端ベルトである定着ベルト２６に加圧ローラ２７を押し当てて構成する。
【００２５】
上述した２次転写装置２２には、画像転写後のシートをこの定着装置２５へと搬送するシート搬送機能も備えてなる。もちろん、２次転写装置２２として、転写ローラや非接触のチャージャを配置してもよく、そのような場合は、このシート搬送機能を併せて備えることは難しくなる。
なお、図示の例では、このような２次転写装置２２および定着装置２５の下側に、上述したタンデム画像形成装置２０と平行に、シートの両面に画像を記録すべくシートを反転するシート反転装置２８を備える。
【００２６】
さて、いまこのカラー電子写真複写機を用いてコピーをとるときは、原稿自動搬送装置４００の原稿台３０上に原稿をセットする。または、原稿自動搬送装置４００を開いてスキャナ３００のコンタクトガラス３２上に原稿をセットし、原稿自動搬送装置４００を閉じてそれで押さえる。
【００２７】
そして、不図示のスタートスイッチを押すと、原稿自動搬送装置４００に原稿をセットしたときは、原稿を搬送してコンタクトガラス３２上へと移動して後、他方コンタクトガラス３２上に原稿をセットしたときは、直ちにスキャナ３００を駆動し、第１走行体３３および第２走行体３４を走行する。そして、第１走行体３３で光源から光を発射するとともに原稿面からの反射光をさらに反射して第２走行体３４に向け、第２走行体３４のミラーで反射して結像レンズ３５を通して読取りセンサ３６に入れ、原稿内容を読み取る。
【００２８】
また、不図示のスタートスイッチを押すと、不図示の駆動モータで支持ローラ１４，１５，１６の１つを回転駆動して他の２つの支持ローラを従動回転し、中間転写体１０を回転搬送する。同時に、個々の画像形成手段１８でその感光体４０を回転して各感光体４０上にそれぞれ、ブラック，イエロー，マゼンタ，シアンの単色画像を形成する。そして、中間転写体１０の搬送とともに、それらの単色画像を順次転写して中間転写体１０上に合成カラー画像を形成する。
【００２９】
一方、不図示のスタートスイッチを押すと、給紙テーブル２００の給紙ローラ４２の１つを選択回転し、ペーパーバンク４３に多段に備える給紙カセット４４の１つからシートを繰り出し、分離ローラ４５で１枚ずつ分離して給紙路４６に入れ、搬送ローラ４７で搬送して複写装置本体１００内の給紙路４８に導き、レジストローラ４９に突き当てて止める。
または、給紙ローラ５０を回転して手差しトレイ５１上のシートを繰り出し、分離ローラ５２で１枚ずつ分離して手差し給紙路５３に入れ、同じくレジストローラ４９に突き当てて止める。
【００３０】
そして、中間転写体１０上の合成カラー画像にタイミングを合わせてレジストローラ４９を回転し、中間転写体１０と２次転写装置２２との間にシートを送り込み、２次転写装置２２で転写してシート上にカラー画像を記録する。
画像転写後のシートは、２次転写装置２２で搬送して定着装置２５へと送り込み、定着装置２５で熱と圧力とを加えて転写画像を定着して後、切換爪５５で切り換えて排出ローラ５６で排出し、排紙トレイ５７上にスタックする。または、切換爪５５で切り換えてシート反転装置２８に入れ、そこで反転して再び転写位置へと導き、裏面にも画像を記録して後、排出ローラ５６で排紙トレイ５７上に排出する。
一方、画像転写後の中間転写体１０は、中間転写体クリーニング装置１７で、画像転写後に中間転写体１０上に残留する残留トナーを除去し、タンデム画像形成装置２０による再度の画像形成に備える。
【００３１】
図１０は、本実施形態に用いる現像装置を示している。この現像装置８０は、現像剤担持体としての現像ローラ６５、現像剤を収容する現像ケーシング６１、現像剤を攪拌・搬送する２つの攪拌・搬送スクリュー６８、現像ローラ６５により担持・搬送される現像剤量を規制するドクターブレード７３などで構成されている。現像ローラ６５は、マグネットローラ７２を内蔵している。
【００３２】
この現像装置８０では、現像ケーシング６１に収容する現像剤として、磁性キャリアとトナーとからなる二成分現像剤を用いている。この磁性キャリアとトナーとは、攪拌・搬送スクリュー６８の回転により、攪拌されながら現像ローラ６５に向けて搬送される。現像ローラ６５に向けて搬送された現像剤は、マグネットローラ７２の磁極の磁力とドクターブレード７３の規制作用とにより、現像ローラ６５の回転に伴ってドクターブレード７３の現像剤搬送方向上流側に滞留保持される。この滞留保持された現像剤は、現像ローラ６５の回転により更に攪拌されて、現像剤中のトナーの摩擦帯電が促進される。トナーが摩擦帯電された現像剤は、現像ローラ６５により担持・搬送され、ドクターブレード７３の先端と現像ローラ６５の表面との隙間を通過することで薄層化される。ドクターブレード７３の先端付近には磁性体が設置されている。この磁性体は、現像ローラ６５の対向磁力の方向性を均一化して、ドクターブレード７３の先端と現像ローラ６５の表面との隙間を通過する現像剤量のバラツキを抑えている。このようにして薄層化された現像剤は、現像ローラ６５の回転により、潜像担持体としての感光体ドラム４０と現像ローラ６５とが対向する現像領域に向けて担持・搬送される。この現像領域には、図示しない現像バイアス印加手段により現像ローラ６５に所定の現像バイアスが印加されることによって、所定の現像電界が形成されている。感光体ドラム４０の表面には、上述した潜像形成手段により静電潜像が形成されている。この静電潜像は、上述の現像領域に形成された現像電界の作用により、現像ローラの表面に担持されている現像剤中の帯電トナーにより可視像化される。
【００３３】
図１１は、図９の点線で囲んだ、現像スリーブを搭載した現像装置８０、感光体ドラム４０、感光体クリーニング装置６３、帯電装置６０が内包されたプロセスカートリッジの概略図である。このプロセスカートリッジ５００は、上記実施形態の画像形成装置に設けられる各画像形成ユニット１８Ｙ，１８Ｃ，１８Ｍ，１８Ｋを、画像形成装置本体に対して着脱可能に一体構成したものである。このように各画像形成ユニット１８Ｙ，１８Ｃ，１８Ｍ，１８Ｋをプロセスカートリッジ５００として構成すれば、これに収容された部品に寿命が到来したり、メンテナンスが必要になったりしたときには、そのプロセスカートリッジを交換すればよく、利便性が向上する。なお、プロセスカートリッジとして一体構成する部品は、少なくとも感光体ドラム４０と現像装置８０とが含まれていれば、そのほかにどのような部品を含ませてもよい。
【００３４】
次に、本実施形態に使用される現像剤のキャリアについて図１２を用いて説明する。
二成分現像剤のキャリアとしては、弾力性と強い接着力とを有するコート膜であって、膜厚よりも大きい径を有する粒子を表面に含有したコート膜で被覆したものを用いることが望ましい。キャリア９０の芯材としてフェライト９１を用いている。このフェライト９１の表面を、アクリル等の熱可塑性樹脂とメラミン樹脂とを架橋させた樹脂成分に、帯電調整剤を含有させたコート膜９２で被覆している。このコート膜９２は弾力性と強い接着力を有している。さらに、コート膜９２の膜厚よりも大きい径の粒子、例えばアルミナ粒子９３を表面に分散している。アルミナ粒子９３はコート膜９２の強い接着力で保持されている。従来のキャリアは硬いコート膜を徐々に削りながら長寿命を得るという思想の基で構成されていたのに対し、図示のキャリア９０はコート膜９２が弾力性を有することで衝撃を吸収して膜削れを抑制する。また、膜厚よりも大きい径を有するアルミナ粒子９３をキャリア９０表面に分散することで、コート膜９２への衝撃を阻止し、しかもスペント物のクリーニングを行なうことができる。このように、コート膜の膜削れとスペント化を抑制できるので、従来のキャリアに比べ、より長寿命化を図ることができる。これにより、長期間に渡り、トナー汲上量の安定化、すなわち品質の安定化を期待できる。
【００３５】
本実施形態に使用されるキャリア粒径の大きさは、２０μｍ以上５０μｍ以下としている。キャリアの粒径５０μｍ以下であれば、画像の粒状度が良く、高画質を経時で維持することが可能となる。ここで、上記磁性キャリアの粒径は、細かいほどよいが、現状では、最小で２０μｍが加工限界とされている。
【００３６】
次に、本実施形態に用いる現像剤のトナーについて説明する。
まず、本実施形態に用いるトナーの製造方法について説明する。
基本樹脂準備→乳化→熟成→脱溶剤→アルカリ洗浄、水洗→乾燥→外添剤処理という一連の流れが製造工程の概要である。まず、酢酸エチル等の有機溶媒に、樹脂、着色剤、ワックス、帯電制御剤等を溶解させたものを基本樹脂溶液とする。そして、界面活性剤、粘度調整剤、樹脂微粒子を含有する水系媒体に、上記基本樹脂溶液とアミン類とを加えて、せん断力により分散させて、乳化状態を生起せしめる。次いで、イソシアネート基とアミン類との作用による伸長や架橋反応を促進させるべく、反応系を加熱して熟成させる。そして、例えば、系全体を徐々に昇温して、液滴中の有機溶媒を蒸発除去するなどの方法により、脱溶剤処理を行う。次に、脱溶剤によって得られたトナー粒子表面に残存している異物（界面活性剤、粘度調整剤など）を除去すべく、アルカリ洗浄処理や水洗処理を施す。そして、濾過によってトナー粒子を回収した後、乾燥させる。更に、必要に応じて、シリカ、チタニア、アルミナ等の外添剤微粒子をミキサー等によって０．１〜５．０重量部程度の量で外添する。
【００３７】
より詳しい製造例について説明すると、例えば次のようになる。
まず、冷却管、攪拌機及び窒素導入管の付設された反応槽中にて、ビスフェノールＡエチレンオキサイド２モル付加物６９０重量部と、テレフタル酸２５６重量部とを常圧且つ２３０℃の環境下で８時間重縮合反応させる。そして、１０〜１５ｍｍＨｇまで減圧せしめて５時間反応させてから１６０℃まで冷却した後、１８重量部の無水フタル酸を加えて更に２時間反応させて変性されていないポリエステル（ａ）を得る。
【００３８】
かかるポリエステル（ａ）とは別に、ベースとなるポリマー１分子中に２以上の反応基を有するプレポリマーを準備する。具体的には、ビスフェノールＡエチレンオキサイド２モル付加物８００重量部と、イソフタル酸１８０重量部と、テレフタル酸６０重量部と、ジブチルチンオキサイド２重量部とを反応槽中に入れる。そして、常圧且つ２３０℃の環境下で８時間重縮合反応させた後、１０〜１５ｍｍＨｇまで減圧して脱水しながら５時間反応させる。次いで、１６０℃まで冷却してから、３２重量部の無水フタル酸を加えて更に２時間反応させる。そして、８０℃まで冷却して酢酸エチル中にてイソホロンジイソシアネート１７０重量部と２時間反応させて、イソシアネート基含有プレポリマー（１）を得る。
【００３９】
また、ケチミン化合物も準備する。例えば、攪拌棒及び温度計の付設された反応槽中に、イソホロンジアミン３０重量部とメチルエチルケトン７０重量部を入れて、５０［℃］で５時間反応させてケチミン化合物（２）を得る。
【００４０】
上記イソシアネート基含有プレポリマー（１）１５．４重量部と、上記ポリエステル（ａ）６０重量部と、酢酸エチル７８．６重量部とをビーカー内に入れて攪拌溶解する。そして、離型促進剤であるライスＷＡＸ（融点８３℃）１０重量部と、銅フタロシアニンブルー顔料（シアン顔料）４重量部とを入れて、ＴＫ式ホモミキサーを用いて６０℃の環境下にて１２０００ｒｐｍの速度で攪拌して、均一に溶解、分散させる。次いで、上記ケチミン化合物（２）２．７重量部を加え溶解させて、基本樹脂溶液（３）を得る。
【００４１】
イオン交換水３０６重量部と、リン酸カルシウム１０％懸濁液２６５重量部と、ドデシルベンゼンスルホン酸ナトリウム０．２重量部と、平均粒径０．２０μｍのスチレン／アクリル系樹脂微粒子とをビーカー内に入れて均一に溶解する。そして、６０℃に昇温した後、ＴＫ式ホモミキサーを用いて１２０００ｒｐｍの速度で攪拌しながら、上記基本樹脂溶液（３）を投入して１０分間攪拌する。次いで、得られた混合液を攪拌棒及び温度計の付設されたコルベンに５００ｇ移して４５℃まで昇温した後、減圧下にてウレア化反応させながら０．５時間かけて溶剤を除去する。そして、濾別、洗浄、乾燥工程を経てから風力分級して母体粒子（４）を得る。
【００４２】
上記母体粒子１００重量部と、帯電制御剤（オリエント化学社製 ボントロンＥ−８４）０．２５重量部とをＱ型ミキサー（三井鉱山社製）に入れる。そして、ミキサーのタービン型羽根の周速を５０ｍ／ｓｅｃに設定して、２分間のミキシングと１分間の休止とを５セット行う。次いで、０．５重量部の疎水性シリカ（Ｈ２０００、クラリアントジャパン社製）を添加してから、周速１５ｍ／ｓｅｃの設定で３０秒間のミキシングと１分間の休止とを５セット行って、トナー粒子を得る。そして、このトナー粒子１００重量部と、疎水性シリカ０．５重量部と、疎水化酸化チタン０．５重量部とをヘンシェルミキサーにて混合して、シアントナーを得る。上述の基本樹脂溶液の組成における銅フタロシアニンブルー顔料（シアン顔料）４重量部を次のように変更すれば、他色のトナーを得ることができる。
・イエロートナー：ベンジジンイエロー顔料６重量部
・マゼンタトナー：ローダミンレーキ顔料６重量部
・ブラックトナー：カーボンブラック１０重量部
【００４３】
本実施形態によれば、現像スリーブは、外周に軸方向にのびる溝を備えている。よって、現像スリーブの外周をサンドブラスト加工によって荒らしたものよりも、現像剤の搬送能力が長期間に渡り維持することができる。
また、本実施形態の現像スリーブの製造方法によれば、熱間押出し製造されたアルミニウムの素管は、冷間引き抜き加工による溝の形成前に研削加工によって現像スリーブの振れを３０μｍ以下にしている。これにより、現像スリーブの一周回転におけるドクターギャップや現像ギャップの変動が抑えられる。この結果、これらのギャップ変動によって引き起こされる画像の乱れを防止することができる。また、溝形成前に振れ精度を向上させる加工を施しているので、溝の深さ偏差も３０μｍ以下に抑えることができる。この結果、トナーの搬送能力が周方向および軸方向で均一となり、高画質の画像を得ることができる。
また、本実施形態の現像スリーブの製造方法によれば、冷間引き抜き加工では、溝のみを形成するようにしている。本実施形態によれば、溝加工前に外周の振れ精度が十分高められているので、溝の加工と同時にスリーブの外径寸法精度を上げる加工を施こす必要が無い。よって、従来の引き抜き加工では、スリーブ全体に応力がかかっていたが、本実施形態では、溝のみの加工で済むので、引き抜き加工時に現像スリーブにかかる応力が溝の形成時にかかる応力のみに抑えることができる。この結果、振れ精度を高める加工後に、引き抜き加工しても振れ精度悪化することがない。
また、本実施形態の現像スリーブの製造方法によれば、仕上げ加工を施している。これにより、現像スリーブの振れ精度を２０μｍ以下とすることができ、現像ギャップを狭めても、スリーブの振れによる画質の乱れがない。この結果、より高画質の画像を得ることができる。
また、本実施形態の現像スリーブの製造方法によれば、仕上げ加工として切削加工を用いている。これにより、研削加工のように削りカスが溝に溜まることがない。この結果、現像剤担持能力を発揮する溝深さが確保され、現像ローラを高速回転させても、確実に現像剤を担持することができる。
また、本実施形態の現像スリーブの製造方法によれば、現像スリーブの材料をビッカース硬度６０以上のアルミニウムとしている。これにより、切削加工時に発生するバリが抑えられ、装置作動中にバリが剥がれて、画像形成装置の画像に悪影響を与えることがなくなる。また、硬度が高いため、磨耗しにくくなり、現像剤等との磨耗による溝深さの減りが遅くなり、長期にわたり、トナー搬送能力を維持することができる。
また、本実施形態の現像装置によれば、振れがほとんど無く溝を有した現像スリーブの採用により、高速・高画質のトナー像形成に適応できる現像装置とすることができる。
また、本実施形態の現像装置によれば、二成分現像剤の磁性キャリアは、平均粒径は２０μｍ以上５０μｍ以下のものである。このような範囲の粒径の磁性キャリアを用いることにより、画像の粒状度が向上し、高品質の画像を得ることができる。また、この磁性キャリアは、磁性体の芯材に対して樹脂コート膜を有するものであって、該樹脂コート膜が、アクリル等の熱可塑性樹脂とメラニン樹脂とを架橋させた樹脂成分に帯電調整剤を含有させたものである。この磁性キャリアを用いることにより、衝撃を吸収して削れを抑制し、強い接着力により大粒子を保持できる効果と、コート膜への衝撃阻止およびスペント物のクリーニングという効果とをバランス良く得ることができる。従って、現像剤の長寿命すなわち膜削れとスペント化を防止できる。
また、本実施形態の現像装置によれば、現像剤のトナーは、少なくとも、プレポリマー、着色剤、離型剤からなるトナー組成物を、水系媒体中で樹脂微粒子の存在下で分散させ、該トナー組成物を重付加反応させて得られた重合トナーを用いる。このようなトナーを用いることにより、粉砕工程がなく、小資源化を図ることができ、粒径分布および帯電分布がシャ−プにでき、円形度を変える形状制御が容易にできる等の効果を得ることができる。
また、本実施形態の画像形成装置は、上述のキャリアを用いた現像剤と、上述の現像スリーブを備えるので、高速・高画質の画像形成装置とすることができる。
【００４４】
【発明の効果】
請求項１乃至３の現像担持体の製造方法によれば、現像スリーブの振れが抑えられ、ドクターギャップや現像ギャップの変動によって引き起こされる画像の乱れを防止することができるという優れた効果がある。
【図面の簡単な説明】
【図１】実施形態に係る現像ローラの概略図。
【図２】実施形態に係る画像形成装置の要部説明図。
【図３】実施形態に係る現像スリーブの振れ精度加工である研削加工を示す図。
【図４】実施形態に係る現像スリーブの溝形成加工である引き抜き加工を示す図。
【図５】実施形態に係る現像スリーブの溝形成加工である引き抜き加工前と加工後の振れ精度の分布を示す図。
【図６】実施形態に係る現像スリーブの溝形成加工である引き抜き加工前と仕上げ加工後の振れ精度の分布を示す図。
【図７】実施形態に係る現像スリーブの仕上げ加工の一例を示す図。
【図８】実施形態に係る現像スリーブの仕上げ加工の他の例を示す図。
【図９】実施形態に係る画像形成装置の概略図。
【図１０】実施形態に係る現像装置の該略図。
【図１１】実施形態に係るプロセスカートリッジの概略図
【図１２】実施形態に係る磁性キャリアの概略図。
【符号の説明】
１８ 画像形成部
２０ タンデム画像形成部
４０ 感光体ドラム
６０ 帯電装置
８０ 現像装置
６２ 一次転写装置
６３ 感光体クリーニング装置
６５ 現像ローラ（現像剤担持体）
７３ ドクターブレード
９０ 磁性キャリア
６５０ 現像スリーブ
６５２ａ、６５２ｂ フランジ
７１１ ダイス[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a developer carrier used in an image forming apparatus such as a copying machine, a printer, and a facsimile machine. The present invention also relates to a developing device, an image forming apparatus, and a process cartridge provided with a developer carrier manufactured by this manufacturing method.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a developing device for forming a toner image by supplying toner to the surface of a photosensitive member as a latent image carrier on which a latent image is formed is transferred to a sheet-like transfer material such as paper. An image forming apparatus configured as described above is known.
As the developing device, for example, a developer composed of toner and a carrier is supplied to the surface of the photosensitive member by a developing roller as a developer carrying member having a built-in magnet that is rotatably supported in the developing device. One that forms a toner image on the surface of a body is known.
The developing device is provided with a doctor blade disposed in the axial direction of the developing roller at a predetermined interval from the developing sleeve in order to regulate the amount of developer adsorbed on the developing sleeve.
Even if the developing roller rotates at high speed, the developing sleeve is roughened by applying groove processing or sandblasting so that the developer slips at the cylindrical portion of the developing roller (hereinafter referred to as the developing sleeve) and does not stagnate near the doctor blade. What is known is also known (for example, Patent Document 1).
[0003]
This developing sleeve is processed as follows. First, aluminum is extruded hot to form a cylindrical shape. As the material of the developing sleeve, brass, stainless steel, conductive resin, etc. can be used in addition to aluminum, but aluminum alloy (JIS standard A6063-T5) is often used from the viewpoint of cost and accuracy.
Next, grooving or sandblasting is applied to the outer peripheral surface of the sleeve. Groove machining is performed as follows. A groove extending in the axial direction is formed on the outer periphery of the sleeve by cold-drawing the cylindrical aluminum from the inner peripheral surface of the die having a trapezoidal, V-shaped or U-shaped convex portion formed on the inner peripheral surface. The The groove of the sleeve has a depth of 0.02 mm and the number is about 50 to 100. The groove may be formed at the time of hot extrusion production of aluminum.
On the other hand, sandblasting is performed by spraying abrasive grains cold on the sleeve. The surface roughness of the sleeve is about Rz 5 to 15 [μm].
Then, the developer carrier is formed by fixing the flange by press-fitting or adhering it to both ends of the sleeve.
[0004]
The developing device is provided with a doctor blade disposed in the axial direction of the developing roller at a predetermined interval from the developing sleeve in order to regulate the amount of developer adsorbed on the developing sleeve. The distance between the developing sleeve and the doctor blade (hereinafter referred to as a doctor gap) must be set to a tight tolerance accuracy in order to make the amount of the developer supplied to the photosensitive member uniform. Similarly, the gap between the photosensitive member and the developing sleeve (hereinafter referred to as a developing gap) is strictly tolerance accuracy in order to make the electric field for electrostatically moving the toner carried on the developing sleeve to the photosensitive member constant. Must be set to
[0005]
[Patent Document 1]
Japanese Utility Model Publication No. 7-16943
[Patent Document 2]
JP-A-8-74839
[0006]
[Problems to be solved by the invention]
However, if the developing sleeve is shaken, the doctor gap and the developing gap change during one rotation of the developing sleeve. When the doctor gap fluctuates, the toner is not uniformly supplied to the surface of the photoreceptor, and unevenness in image density occurs. Further, if the development gap changes, the electric field changes, and the amount of toner transferred to the photoconductor changes, resulting in uneven density of the image density.
In order to suppress such a phenomenon, it is necessary to increase the runout accuracy of the developing sleeve. However, it has been difficult to obtain a runout accuracy of 30 μm or less with the above-described processing method.
Therefore, in Patent Document 2, in order to suppress the shake of the developing sleeve, the developing sleeve and the shaft member are subjected to cutting or grinding to improve the shake accuracy, and then subjected to sand blasting. However, when the sandblasting is performed, there is a case where the developer conveying ability is deteriorated because fine irregularities disappear due to wear with the developer while the developing sleeve is used over time. In order to maintain the developer conveying capability over time, a method of forming grooves is effective.
[0007]
When performing grooving, various methods such as cutting are conceivable, but drawing with a die is advantageous in terms of manufacturing cost and the like. The inner diameter of the die is made slightly smaller than the outer diameter of the sleeve, and the processing for increasing the outer diameter dimensional accuracy of the sleeve is performed at the same time as the groove processing. After this drawing process, it may be possible to increase the runout accuracy by cutting or grinding, but on the contrary, a deviation occurs in the groove depth, and the toner conveyance capability is uniform in the circumferential direction and the axial direction. It disappeared, causing unevenness of shading in the image.
[0008]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a high-quality image while suppressing the shake of the developer carrier.
[0009]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the invention of claim 1 is arranged so as to be rotatable in opposition to a latent image carrier having a latent image formed on the surface thereof, and to form the latent image into a toner image. Developer carrier for supplying developer to Manufacturing method In The developer carrier has a cylindrical portion, and the cylindrical portion is aluminum having a Vickers hardness of 60 or more, and after increasing the runout accuracy by grinding, only the grooves are formed by drawing, After the groove is formed by drawing, the outer periphery of the developer carrying member is subjected to cutting for improving the runout accuracy. It is characterized by this.
Further, the invention of claim 2 is claimed in claim 1's In the method for producing a developer carrier, Above The runout of the developer carrying member is 30 μm or less.
Further, the invention of claim 3 is the invention of claim 1. Or 2 In the method for producing a developer carrier of Above The depth deviation of the groove is 30 μm or less.
Further, the invention of claim 4 is the invention of claim 1, 2 or 3 The developer carrying body formed by the method for producing a developer carrying body is provided.
Further, the invention of claim 5 is claimed in claim 4 In this developing apparatus, the developer used in the developing apparatus is a two-component developer having a toner and a magnetic carrier, and the particle size of the magnetic carrier is 20 μm or more and 50 μm or less.
Further, the invention of claim 6 is a claim. 4 or 5 In this developing apparatus, the magnetic carrier is formed by coating the surface of a core made of a magnetic material with a resin coat film, and the resin coat film is charged with a resin component obtained by crosslinking a thermoplastic resin and a melamine resin. It is characterized by containing a regulator.
The invention of claim 7 is a 4, 5 or 6 In the developing apparatus, a toner composition comprising at least a prepolymer, a colorant, and a release agent may be dispersed in an aqueous medium in the presence of resin fine particles, and the toner composition may be subjected to a polyaddition reaction. In this case, the toner is a produced toner.
The invention of claim 8 is a Item 4, 5, 6 or 7 The developing device is provided.
Further, the invention of claim 9 is a claim. 4, 5, 6, 7 Development device or claim 8 The process cartridge is provided.
[0010]
Claims 1 to 3 In the developer carrying member manufacturing method, after the deflection accuracy of the developer carrying member is increased by the processing for improving the shaking accuracy of the developer carrying member, the groove is formed by drawing. Since the runout accuracy of the developer carrier is improved by the cutting process, fluctuations in the doctor gap and the development gap in one rotation of the developer carrier are eliminated. Also, when the runout accuracy is improved after the groove formation, the depth deviation of the groove may fluctuate and the depth deviation of the groove may vary, but processing is performed to improve the runout accuracy before the groove formation. Therefore, the depth deviation of the groove does not shake greatly.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic view of a developing roller as a developer carrying member prepared by applying the processing method of the present invention. On the outer periphery of the developing roller 65, a cylindrical developing sleeve 650 formed with a plurality of axially extending grooves and flanges 652a and 652b fixed to both ends thereof are provided. In the center of the left flange 652a in the drawing, a hole is provided in which a shaft extending from a magnet 72 as a magnetic field generating means provided in the developing sleeve 650 is inserted. A boss portion 651a extending outward in the axial direction is formed around the hole, and this boss portion is a journal portion of the developing sleeve. A developing sleeve journal 651b extending outward in the axial direction is provided at the center of the flange 652b on the other side (right side in the figure). The doctor blade 73 extends in the axial direction of the developing roller 65 with a predetermined distance from the developing sleeve 650. The doctor blade 73 is screwed to the case of the developing device.
Further, in the center of the right flange 652b in the drawing, a sleeve journal portion 651b is further provided with a developing roller journal portion 651c extending outward in the axial direction. The journal portion 651 d of the other developing roller is constituted by a shaft extending from the magnet 72. These journal portions 651c and 651d of the developing roller are rotatably supported by bearings press-fitted into a developing device described later.
[0012]
FIG. 2 is a schematic view of a developing device incorporated in the image forming apparatus. The developing device is provided with the developing roller 65 shown in FIG. In the developing device 80, as shown in FIG. 2, a developing roller 65 is provided at a position facing the photosensitive drum 40 with a gap from the photosensitive drum. The developing roller 65 is incorporated into the developing device 80 by supporting the journal portion 651 of the developing roller within the developing device. The developing roller 65 is rotated counterclockwise in the drawing by a driving unit (not shown). The magnet 72 inside the developing roller 65 generates magnetic lines of force as shown by dotted lines in the figure. A stirring roller 68 is disposed in the developing device so as to be adjacent to the developing roller 65. The stirring roller 68 is also rotated counterclockwise in the drawing by a driving means (not shown). The developing device contains a two-component developer containing toner and a magnetic carrier.
[0013]
Hereinafter, an embodiment of a developing sleeve manufacturing method using the present invention will be described. First, an aluminum cylindrical tube is formed by hot extrusion. Next, the flange 652a is press-fitted and fixed to one side of the raw tube. Grinding is performed on the outer periphery of the developing sleeve in such a state. The state is shown in FIG. One holding portion 780 of the grinding apparatus holds the boss portion 651a, and the other holding portion 780 holds the end portion of the sleeve. The boss portion 651a is supported as a journal portion of the sleeve so that the doctor blade is rotatable, and is supported by a shaft of a magnet that is a journal portion of the developing roller. Therefore, by grinding with the boss portion 651a as a reference, high runout accuracy is maintained even when incorporated in the developing device. Then, the sleeve is rotated by rotating the holding portion 780. Then, the grindstone 710a is slid in the axial direction of the developing sleeve 650, and grinding is performed until the outer peripheral runout of the developing sleeve 650 becomes 20 μm or less. At the same time, the outer periphery of the boss portion 651a as the journal portion of the sleeve is also ground with another grindstone 710b to increase the deflection accuracy of the boss portion 651a as the journal portion of the sleeve. Thereby, the gap fluctuation between the doctor blade and the sleeve and the gap fluctuation between the photosensitive member and the sleeve can be suppressed.
[0014]
The ground developing sleeve forms only a groove by drawing. The state of the processing is shown in FIG. The inner diameter of the die 711 is formed to be the same as or slightly larger than the outer diameter of the developing sleeve 650, and convex portions 712 such as a V shape, a trapezoidal shape, and a U shape are formed on the inner periphery at equal intervals in the circumferential direction. Is provided. The boss portion 651a is gripped by a gripping member 713 extending from a drawing device main body (not shown) having the same center line as the center of the inner diameter of the die. Then, the gripping member 713 is moved to the left (drawing direction) in the drawing. As a result, the developing sleeve 650 is pulled out from the inner periphery of the die 711, and only a groove extending in the axial direction is formed in the developing sleeve. The groove of the sleeve is formed so that the groove depth is 5 to 10% of the thickness of the sleeve and the groove pitch is 7 degrees or less. Since only the grooves are manufactured by drawing, the developing sleeve is not subjected to stress that affects the runout.
[0015]
By performing the above-described processing, the shake accuracy can be suppressed to 30 μm or less and high image quality can be obtained. However, recent image forming apparatuses tend to narrow the development gap in order to obtain a more accurate image. It is in. When the development gap is narrowed, image density unevenness due to shake tends to appear, and it is preferable to have a shake accuracy of 20 μm or less. Even when the runout accuracy distribution was set to 20 μm or less by grinding, stress was applied to the sleeve when the grooves were formed by drawing, and the runout accuracy distribution was deteriorated to 25 μm (see FIG. 5). However, by performing the finishing process shown below, the distribution of runout accuracy can be suppressed to 20 μm or less (see FIG. 6).
[0016]
This finishing process is performed on the outer periphery of the developing sleeve. This is because when grinding is performed, even if the type of grinding wheel and grinding conditions are changed, scraps accumulate in the grooves and become clogged. The processed state is shown in FIG. The boss portion 651a is held by the holding portion 781 of the cutting device. The other end of the sleeve 650 is held by the other holding portion 781 of the cutting device. The holding portion 781 is rotated to rotate the sleeve 650. Then, the tool 715 is slid in the axial direction of the developing sleeve 650 to further improve the deflection accuracy of the developing sleeve 650. At the same time, the outer periphery of the boss portion 651a is cut to increase the deflection accuracy of the boss portion 651a. After finishing, a magnet 72 as a magnetic field generating means is inserted, and a flange 652b is press-fitted and fixed to the other end of the sleeve 650 to obtain a developing roller 65 shown in FIG.
[0017]
In the above description, cutting is performed after the flange 652a is press-fitted and fixed only to one end of the sleeve, but this is not a limitation. Cutting may be performed after the flanges 652a and 652b are press-fitted and fixed to both ends of the sleeve. In this case, after fixing the flange 652a to one side of the sleeve, the magnet 72 is inserted, and the other flange is press-fitted into the sleeve. The boss portion 651a and the sleeve journal portion 651b, which are the journal portions of the sleeve, are held by the holding portion 781 of the turning device. Then, the holding portion 781 is rotated to rotate the sleeve 650. The cutting tool 715 is slid in the axial direction of the developing sleeve 650 to finish the developing sleeve 650.
[0018]
When cutting is applied to the finishing process, burrs may occur depending on the material. If the developing sleeve is incorporated in the image forming apparatus with the burrs attached, the burrs may be peeled off from the developing sleeve during use, and the image may be disturbed or the surface of the photoreceptor may be damaged.
Therefore, the hardness of the material was changed to investigate how the occurrence of burrs affects the image.
Examples 1 to 5 are sleeves manufactured by the above-described manufacturing method. The material is an aluminum alloy (JIS standard A6063), and a hardness difference is obtained by post-processing.
These developing sleeves were incorporated into an image forming apparatus, and the state of the image was evaluated. The results are shown below.
[0019]
[Table 1]

[0020]
In Examples 1 and 2, a decrease in image density was confirmed from the initial use. This is presumably because a lot of burrs are generated in the sleeve, and the burrs hinder the pumping of the developer, and the transportability of the developer is not sufficient.
In Example 3, there was no problem in the developer transportability, and there was no problem in the initial stage of use. However, as the image was used for a long time, image distortion was confirmed. This is considered to have occurred because the burrs adhering to the sleeve peeled off and damaged the photoreceptor.
In Example 4, although some burr was observed, the image was not affected. In Example 5, there was almost no burrs and the image was not affected.
[0021]
From the above results, when the Vickers hardness exceeds 60, even when incorporated in a developing device, it is possible to suppress the occurrence of burrs at a level that does not cause a problem in actual use.
[0022]
FIG. 9 is a schematic view of an image forming apparatus on which a developing sleeve created by the processing method of the present embodiment is mounted. The image forming apparatus mainly includes a copying machine main body 100, a paper feed table 200 on which the copying machine main body is placed, a scanner 300 mounted on the copying apparatus main body, and an automatic document feeder (ADF) 400 mounted thereon. Yes.
The copying machine main body 100 is provided with an endless belt-shaped intermediate transfer member 10 at the center.
[0023]
In the example of FIG. 9, the intermediate transfer member 10 is wound around three support rollers 14, 15, and 16 so as to be able to rotate and convey in the clockwise direction in the drawing.
In the illustrated example, an intermediate transfer body cleaning device 17 that removes residual toner remaining on the intermediate transfer body 10 after image transfer is provided on the left side of the second support roller 15 among the three support rollers. On the intermediate transfer member 10 stretched between the first support roller 14 and the second support roller 15, four image forming units of black, yellow, magenta, and cyan are arranged along the transport direction. The tandem image forming apparatus 20 is configured by arranging 18 horizontally. An exposure device 21 is provided above the tandem image forming apparatus 20 as shown in FIG.
[0024]
On the other hand, a secondary transfer device 22 is provided on the side opposite to the tandem image forming apparatus 20 with the intermediate transfer body 10 interposed therebetween. In the illustrated example, the secondary transfer device 22 is configured by spanning a secondary transfer belt 24, which is an endless belt, between two rollers 23, and is pressed against the third support roller 16 via the intermediate transfer body 10. The image on the intermediate transfer body 10 is transferred to a sheet.
A fixing device 25 for fixing the transferred image on the sheet is provided beside the secondary transfer device 22. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt.
[0025]
The secondary transfer device 22 described above is also provided with a sheet transport function for transporting the image-transferred sheet to the fixing device 25. Of course, a transfer roller or a non-contact charger may be arranged as the secondary transfer device 22, and in such a case, it is difficult to provide this sheet conveying function together.
In the illustrated example, the sheet reversal that reverses the sheet so as to record images on both sides of the sheet is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20 described above. A device 28 is provided.
[0026]
Now, when making a copy using this color electrophotographic copying machine, a document is set on the document table 30 of the automatic document feeder 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed and pressed by it.
[0027]
When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. At that time, the scanner 300 is immediately driven to travel the first traveling body 33 and the second traveling body 34. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34, and is reflected by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.
[0028]
When a start switch (not shown) is pressed, one of the support rollers 14, 15 and 16 is rotationally driven by a drive motor (not shown), the other two support rollers are driven to rotate, and the intermediate transfer body 10 is rotated and conveyed. To do. At the same time, the individual image forming means 18 rotates the photoconductor 40 to form black, yellow, magenta, and cyan monochrome images on each photoconductor 40. Then, along with the conveyance of the intermediate transfer member 10, the single color images are sequentially transferred to form a composite color image on the intermediate transfer member 10.
[0029]
On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, and the sheet is fed out from one of the paper feed cassettes 44 provided in multiple stages in the paper bank 43, and the separation roller 45. Are separated one by one into the paper feed path 46, transported by the transport roller 47, guided to the paper feed path 48 in the copying apparatus main body 100, and abutted against the registration roller 49 and stopped.
Alternatively, the sheet feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped.
[0030]
Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer member 10, the sheet is fed between the intermediate transfer member 10 and the secondary transfer device 22, and transferred by the secondary transfer device 22. A color image is recorded on the sheet.
The image-transferred sheet is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the switching roller 55 is used to switch the discharge roller. The paper is discharged at 56 and stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.
On the other hand, the intermediate transfer body 10 after the image transfer is removed by the intermediate transfer body cleaning device 17 to remove residual toner remaining on the intermediate transfer body 10 after the image transfer, so that the tandem image forming apparatus 20 can prepare for another image formation.
[0031]
FIG. 10 shows a developing device used in this embodiment. The developing device 80 includes a developing roller 65 as a developer carrying member, a developing casing 61 that contains the developer, two agitating / conveying screws 68 that agitate and convey the developer, and a development carried and conveyed by the developing roller 65. It is composed of a doctor blade 73 that regulates the amount of the agent. The developing roller 65 has a built-in magnet roller 72.
[0032]
In the developing device 80, a two-component developer composed of a magnetic carrier and toner is used as the developer accommodated in the developing casing 61. The magnetic carrier and the toner are conveyed toward the developing roller 65 while being agitated by the rotation of the agitating / conveying screw 68. The developer conveyed toward the developing roller 65 stays on the upstream side in the developer conveying direction of the doctor blade 73 as the developing roller 65 rotates due to the magnetic force of the magnetic pole of the magnet roller 72 and the regulating action of the doctor blade 73. Retained. The retained developer is further agitated by the rotation of the developing roller 65, and the frictional charging of the toner in the developer is promoted. The developer to which the toner is frictionally charged is carried and conveyed by the developing roller 65, and is thinned by passing through the gap between the tip of the doctor blade 73 and the surface of the developing roller 65. A magnetic body is installed near the tip of the doctor blade 73. This magnetic material makes the direction of the opposing magnetic force of the developing roller 65 uniform, and suppresses variations in the amount of developer passing through the gap between the tip of the doctor blade 73 and the surface of the developing roller 65. The developer thus thinned is carried and conveyed toward the developing region where the photosensitive drum 40 as the latent image carrier and the developing roller 65 face each other by the rotation of the developing roller 65. A predetermined developing electric field is formed in the developing region by applying a predetermined developing bias to the developing roller 65 by a developing bias applying means (not shown). An electrostatic latent image is formed on the surface of the photosensitive drum 40 by the above-described latent image forming unit. This electrostatic latent image is visualized by the charged toner in the developer carried on the surface of the developing roller by the action of the developing electric field formed in the developing area.
[0033]
FIG. 11 is a schematic view of a process cartridge enclosed by a dotted line in FIG. 9 and including a developing device 80 equipped with a developing sleeve, a photosensitive drum 40, a photosensitive member cleaning device 63, and a charging device 60. In the process cartridge 500, the image forming units 18Y, 18C, 18M, and 18K provided in the image forming apparatus according to the above-described embodiment are integrally configured to be detachable from the image forming apparatus main body. If each of the image forming units 18Y, 18C, 18M, and 18K is configured as the process cartridge 500 as described above, the process cartridge can be replaced when the components accommodated therein reach the end of their life or require maintenance. This will improve convenience. In addition, as long as at least the photosensitive drum 40 and the developing device 80 are included, the components integrally configured as the process cartridge may include any other components.
[0034]
Next, the developer carrier used in this embodiment will be described with reference to FIG.
As the carrier for the two-component developer, it is desirable to use a coat film having elasticity and strong adhesive force and coated with a coat film containing particles having a diameter larger than the film thickness on the surface. Ferrite 91 is used as the core material of the carrier 90. The surface of the ferrite 91 is covered with a coat film 92 containing a charge adjusting agent in a resin component obtained by crosslinking a thermoplastic resin such as acrylic and a melamine resin. The coat film 92 has elasticity and strong adhesive force. Further, particles having a diameter larger than the film thickness of the coat film 92, for example, alumina particles 93 are dispersed on the surface. The alumina particles 93 are held with a strong adhesive force of the coating film 92. Whereas the conventional carrier is configured on the basis of the idea of obtaining a long life while gradually scraping a hard coat film, the carrier 90 shown in the figure absorbs an impact because the coat film 92 has elasticity, and absorbs the impact. Suppress cutting. Further, by dispersing alumina particles 93 having a diameter larger than the film thickness on the surface of the carrier 90, it is possible to prevent the impact on the coating film 92 and to clean the spent object. As described above, since the coating film can be prevented from being scraped and spent, it is possible to achieve a longer life than conventional carriers. Accordingly, it is possible to expect stabilization of the toner pumping amount, that is, stabilization of quality over a long period of time.
[0035]
The size of the carrier particle size used in the present embodiment is 20 μm or more and 50 μm or less. If the particle size of the carrier is 50 μm or less, the granularity of the image is good and high image quality can be maintained over time. Here, the finer the particle size of the magnetic carrier, the better. However, at present, the minimum processing limit is 20 μm.
[0036]
Next, the developer toner used in this embodiment will be described.
First, a method for producing a toner used in this embodiment will be described.
A series of flow of preparation of basic resin → emulsification → ripening → solvent removal → alkaline washing, water washing → drying → external additive treatment is an outline of the manufacturing process. First, a basic resin solution is prepared by dissolving a resin, a colorant, a wax, a charge control agent and the like in an organic solvent such as ethyl acetate. Then, the basic resin solution and amines are added to an aqueous medium containing a surfactant, a viscosity modifier, and resin fine particles, and dispersed by shearing force to cause an emulsified state. Next, the reaction system is heated and aged in order to promote elongation and crosslinking reaction due to the action of isocyanate groups and amines. Then, the solvent removal treatment is performed by, for example, a method of gradually raising the temperature of the entire system and evaporating and removing the organic solvent in the droplets. Next, in order to remove foreign matters (surfactant, viscosity modifier, etc.) remaining on the surface of the toner particles obtained by solvent removal, an alkali washing treatment or a water washing treatment is performed. The toner particles are collected by filtration and then dried. Further, if necessary, external additive fine particles such as silica, titania and alumina are externally added in an amount of about 0.1 to 5.0 parts by weight with a mixer or the like.
[0037]
A more detailed manufacturing example will be described as follows, for example.
First, 690 parts by weight of bisphenol A ethylene oxide 2-mol adduct and 256 parts by weight of terephthalic acid in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe were added at a normal pressure and 230 ° C. in an environment of 8 Allow time polycondensation reaction. Then, the pressure is reduced to 10 to 15 mmHg and reacted for 5 hours, and then cooled to 160 ° C. Then, 18 parts by weight of phthalic anhydride is added and further reacted for 2 hours to obtain unmodified polyester (a).
[0038]
Apart from the polyester (a), a prepolymer having two or more reactive groups in one molecule of the base polymer is prepared. Specifically, 800 parts by weight of bisphenol A ethylene oxide 2-mole adduct, 180 parts by weight of isophthalic acid, 60 parts by weight of terephthalic acid, and 2 parts by weight of dibutyltin oxide are placed in a reaction vessel. And after carrying out polycondensation reaction for 8 hours under the environment of normal pressure and 230 degreeC, it is made to react for 5 hours, depressurizing to 10-15 mmHg and dehydrating. Next, after cooling to 160 ° C., 32 parts by weight of phthalic anhydride is added and reacted for another 2 hours. And it cools to 80 degreeC and is made to react with 170 weight part of isophorone diisocyanate in ethyl acetate for 2 hours, and an isocyanate group containing prepolymer (1) is obtained.
[0039]
A ketimine compound is also prepared. For example, 30 parts by weight of isophoronediamine and 70 parts by weight of methyl ethyl ketone are placed in a reaction vessel equipped with a stirrer and a thermometer, and reacted at 50 [° C.] for 5 hours to obtain a ketimine compound (2).
[0040]
15.4 parts by weight of the isocyanate group-containing prepolymer (1), 60 parts by weight of the polyester (a) and 78.6 parts by weight of ethyl acetate are placed in a beaker and dissolved by stirring. Then, 10 parts by weight of rice WAX (melting point: 83 ° C.), which is a mold release accelerator, and 4 parts by weight of copper phthalocyanine blue pigment (cyan pigment) are put in an environment of 60 ° C. using a TK homomixer. Stir at a speed of 12000 rpm to uniformly dissolve and disperse. Next, 2.7 parts by weight of the ketimine compound (2) is added and dissolved to obtain a basic resin solution (3).
[0041]
306 parts by weight of ion-exchanged water, 265 parts by weight of a 10% calcium phosphate suspension, 0.2 parts by weight of sodium dodecylbenzenesulfonate, and styrene / acrylic resin fine particles having an average particle diameter of 0.20 μm are placed in a beaker. And dissolve evenly. Then, after raising the temperature to 60 ° C., the basic resin solution (3) is added and stirred for 10 minutes while stirring at a speed of 12000 rpm using a TK homomixer. Next, 500 g of the obtained mixed solution is transferred to a Kolben equipped with a stirrer and a thermometer, and the temperature is raised to 45 ° C., and then the solvent is removed over 0.5 hours while making a urea reaction under reduced pressure. Then, after passing through filtration, washing, and drying steps, air classification is performed to obtain base particles (4).
[0042]
100 parts by weight of the base particles and 0.25 parts by weight of a charge control agent (Bontron E-84 manufactured by Orient Chemical Co., Ltd.) are placed in a Q-type mixer (Mitsui Mining Co., Ltd.). Then, the peripheral speed of the turbine blades of the mixer is set to 50 m / sec, and 5 sets of 2 minutes of mixing and 1 minute of rest are performed. Next, after adding 0.5 part by weight of hydrophobic silica (H2000, manufactured by Clariant Japan), 5 sets of 30 seconds of mixing and 1 minute of rest were performed at a peripheral speed of 15 m / sec. Get particles. Then, 100 parts by weight of the toner particles, 0.5 parts by weight of hydrophobic silica, and 0.5 parts by weight of hydrophobic titanium oxide are mixed with a Henschel mixer to obtain a cyan toner. If 4 parts by weight of the copper phthalocyanine blue pigment (cyan pigment) in the composition of the basic resin solution is changed as follows, a toner of another color can be obtained.
-Yellow toner: 6 parts by weight of benzidine yellow pigment
・ Magenta toner: Rhodamine lake pigment 6 parts by weight
・ Black toner: 10 parts by weight of carbon black
[0043]
According to the present embodiment, the developing sleeve includes a groove extending in the axial direction on the outer periphery. Therefore, the developer conveying ability can be maintained for a long period of time compared to the case where the outer periphery of the developing sleeve is roughened by sandblasting.
Further, according to the developing sleeve manufacturing method of the present embodiment, the aluminum extruded tube manufactured by hot extrusion has a developing sleeve run-out of 30 μm or less by grinding before forming a groove by cold drawing. . Thereby, the fluctuation | variation of the doctor gap and developing gap in one rotation of a developing sleeve is suppressed. As a result, image disturbance caused by these gap fluctuations can be prevented. In addition, since the processing for improving the runout accuracy is performed before the groove formation, the depth deviation of the groove can be suppressed to 30 μm or less. As a result, the toner conveyance capability is uniform in the circumferential direction and the axial direction, and a high-quality image can be obtained.
Further, according to the developing sleeve manufacturing method of the present embodiment, only the grooves are formed in the cold drawing process. According to this embodiment, since the deflection accuracy of the outer periphery is sufficiently increased before the groove processing, it is not necessary to perform a process for increasing the outer diameter dimensional accuracy of the sleeve simultaneously with the groove processing. Therefore, in the conventional drawing process, stress is applied to the entire sleeve. However, in this embodiment, since only the groove is processed, the stress applied to the developing sleeve during the drawing process is limited to only the stress applied when forming the groove. Can do. As a result, even if the drawing process is performed after the process for improving the runout accuracy, the runout accuracy does not deteriorate.
Further, according to the developing sleeve manufacturing method of this embodiment, finishing is performed. Thereby, the shake accuracy of the developing sleeve can be set to 20 μm or less, and even if the developing gap is narrowed, the image quality is not disturbed by the shake of the sleeve. As a result, a higher quality image can be obtained.
Further, according to the developing sleeve manufacturing method of the present embodiment, cutting is used as finishing. As a result, the scrap does not accumulate in the groove unlike the grinding process. As a result, a groove depth that exhibits the developer carrying ability is secured, and the developer can be carried reliably even when the developing roller is rotated at a high speed.
Further, according to the developing sleeve manufacturing method of the present embodiment, the material of the developing sleeve is aluminum having a Vickers hardness of 60 or more. As a result, burrs generated during the cutting process are suppressed, and burrs are removed during operation of the apparatus, so that the image of the image forming apparatus is not adversely affected. Further, since the hardness is high, it becomes difficult to wear, and the reduction of the groove depth due to wear with the developer or the like becomes slow, so that the toner conveying ability can be maintained over a long period of time.
In addition, according to the developing device of the present embodiment, the developing device can be adapted to high-speed and high-quality toner image formation by adopting a developing sleeve having almost no shake and having a groove.
Further, according to the developing device of this embodiment, the magnetic carrier of the two-component developer has an average particle diameter of 20 μm or more and 50 μm or less. By using a magnetic carrier having a particle size in such a range, the granularity of the image is improved, and a high-quality image can be obtained. In addition, this magnetic carrier has a resin coat film on the magnetic core material, and the resin coat film is charged with a resin component obtained by crosslinking a thermoplastic resin such as acrylic and a melanin resin. It contains an agent. By using this magnetic carrier, it is possible to obtain a good balance between the effect of absorbing impact and suppressing scraping and holding large particles with a strong adhesive force, and the effect of preventing impact on the coating film and cleaning spent materials. it can. Therefore, it is possible to prevent the developer from having a long life, that is, film scraping and spent.
Further, according to the developing device of the present embodiment, the toner of the developer is prepared by dispersing a toner composition including at least a prepolymer, a colorant, and a release agent in an aqueous medium in the presence of resin fine particles. A polymerized toner obtained by polyaddition reaction of the toner composition is used. By using such a toner, there is no pulverization step, resource can be reduced, particle size distribution and charge distribution can be sharpened, and shape control that changes the circularity can be easily performed. Obtainable.
In addition, since the image forming apparatus of the present embodiment includes the developer using the above-described carrier and the above-described developing sleeve, the image forming apparatus can be a high-speed and high-quality image forming apparatus.
[0044]
【The invention's effect】
Claims 1 to 3 According to this developing carrier manufacturing method, there is an excellent effect that the fluctuation of the developing sleeve can be suppressed and the disturbance of the image caused by the fluctuation of the doctor gap or the developing gap can be prevented.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a developing roller according to an embodiment.
FIG. 2 is an explanatory diagram of a main part of the image forming apparatus according to the embodiment.
FIG. 3 is a view showing grinding processing which is runout accuracy processing of the developing sleeve according to the embodiment.
FIG. 4 is a view showing a drawing process which is a groove forming process of the developing sleeve according to the embodiment.
FIG. 5 is a view showing a distribution of runout accuracy before and after the drawing process, which is a groove forming process of the developing sleeve according to the embodiment.
FIG. 6 is a view showing a distribution of runout accuracy before a drawing process and after a finishing process, which is a groove forming process of the developing sleeve according to the embodiment.
FIG. 7 is a view showing an example of a finishing process of the developing sleeve according to the embodiment.
FIG. 8 is a view showing another example of the finishing process of the developing sleeve according to the embodiment.
FIG. 9 is a schematic diagram of an image forming apparatus according to an embodiment.
FIG. 10 is a schematic diagram of a developing device according to an embodiment.
FIG. 11 is a schematic view of a process cartridge according to the embodiment.
FIG. 12 is a schematic diagram of a magnetic carrier according to an embodiment.
[Explanation of symbols]
18 Image forming unit
20 Tandem image forming section
40 Photosensitive drum
60 Charging device
80 Developer
62 Primary transfer device
63 Photoconductor cleaning device
65 Development roller (developer carrier)
73 Doctor Blade
90 Magnetic carrier
650 Development sleeve
652a, 652b Flange
711 Dice

Claims (9)

In a method for producing a developer carrier, which is rotatably arranged opposite to a latent image carrier having a latent image formed on the surface thereof, and supplies the developer to the latent image carrier to form the latent image as a toner image.
The developer carrying member has a cylindrical portion, and the cylindrical portion is aluminum having a Vickers hardness of 60 or more,
After increasing the runout accuracy by grinding, only the grooves are formed by drawing, and cutting for increasing the runout accuracy is performed on the outer periphery of the developer carrying body on which the grooves are formed by the drawing. A method for producing a developer carrier. In the manufacturing method of the developer carrier according to claim 1 ,
A method for producing a developer carrying member, wherein a deflection of the developer carrying member is 30 μm or less. In the manufacturing method of the developer carrier of Claim 1 or 2 ,
A method for producing a developer carrying member, wherein the groove has a depth deviation of 30 μm or less. A developing device comprising the developer carrying member formed by the method for producing a developer carrying member according to claim 1, 2 or 3 . The developing device according to claim 4 .
The developer used in the developing device is a two-component developer having a toner and a magnetic carrier, and the magnetic carrier has a particle size of 20 μm or more and 50 μm or less. 6. The developing device according to claim 4 , wherein the magnetic carrier is formed by coating a resin coating film on a surface of a core material made of a magnetic material, and the resin coating film crosslinks a thermoplastic resin and a melamine resin. A developing device comprising a resin component containing a charge control agent. 7. The developing device according to claim 4 , wherein the toner comprises a toner composition comprising at least a prepolymer, a colorant, and a release agent in an aqueous medium in the presence of resin fine particles. A developing device comprising a toner obtained by polyaddition reaction of a product. A process cartridge comprising the developing device according to claim 4, 5, 6 or 7 . An image forming apparatus comprising the developing device according to claim 4 , or the process cartridge according to claim 8 .

Images