JP4137730B2 - Electrostatic latent image development carrier - Google Patents

Description

【００２０】
前記式中、Ｒ_１は水素原子、ハロゲン原子、ヒドロキシ基、メトキシ基、炭素数１〜４の低級アルキル基、またはアリール基（フェニル基、トリル基など）を示し、Ｒ_２は炭素数１〜４のアルキレン基、またはアリーレン基（フェニレン基など）を示す。
【００２１】
このような樹脂の例としては、例えばストレートシリコーン樹脂として、ＫＲ２７１、ＫＲ２７２、ＫＲ２８２、ＫＲ２５２、ＫＲ２５５、ＫＲ１５２（信越化学工業社製）、ＳＲ２４００、ＳＲ２４０６（東レダウコーニングシリコーン社製）などが例示できる。中でもメチルシリコーン樹脂は、低スペント性、帯電量の環境変動が小さいことなどの理由から好ましく用いられる。
シリコーン樹脂の分子量としては、１０００〜１０００００、好ましくは１０００〜２００００程度である。用いる樹脂の分子量が１０００００より大きい場合、塗布時に塗布液粘度が上昇しすぎ、塗膜の均一性が充分得られなかったり、硬化後に皮膜の密度が充分に上がらない場合がある。１０００より小さいと硬化後の皮膜が脆くなるなどの不具合が生じやすい。
【００２２】
他に、変性シリコーン樹脂も好ましく用いられ、例えばエポキシ変性シリコーン、アクリル変性シリコーン、フェノール変性シリコーン、ウレタン変性シリコーン、ポリエステル変性シリコーン、アルキッド変性シリコーンなどが例示される。上記変性シリコーン樹脂の具体例としては、エポキシ変性物：ＥＳ−１００１Ｎ、アクリル変性シリコーン：ＫＲ−５２０８、ポリエステル変性物：ＫＲ−５２０３、アルキッド変性物：ＫＲ−２０６、ウレタン変性物：ＫＲ−３０５（以上、信越化学工業社製）、エポキシ変性物：ＳＲ２１１５、アルキッド変性物：ＳＲ２１１０（東レダウコーニングシリコーン社製）などが挙げられる。
本発明において、（i）Ｎ−アルコキシアルキル化ポリアミドと、(ii）該Ｎ−アルコキシアルキル化ポリアミド樹脂と反応可能な樹脂としてのこれらシリコーン樹脂との使用割合は１０：９０部〜９０：１０部であることが好ましく、より好ましくは２０：８０部〜５０：５０である。
【００２３】
更に、本発明では、キャリア芯材粒子表面を被覆する樹脂として、以下に示すものを単独、または上記シリコーン樹脂と混合して使用することも可能である。
ポリスチレン、クロロポリスチレン、ポリ−α−メチルスチレン、スチレン−クロロスチレン共重合体、スチレン−プロピレン共重合体、スチレン−ブタジエン共重合体、スチレン−塩化ビニル共重合体、スチレン−酢酸ビニル共重合体、スチレン−マレイン酸共重合体、スチレン−アクリル酸エステル共重合体（スチレン−アクリル酸メチル共重合体、スチレン−アクリル酸エチル共重合体、スチレン−アクリル酸ブチル共重合体、スチレン−アクリル酸オクチル共重合体、スチレン−アクリル酸フェニル共重合体等）、スチレン−メタクリル酸エステル共重合体（スチレン−メタクリル酸メチル共重合体、スチレン−メタクリル酸エチル共重合体、スチレン−メタクリル酸ブチル共重合体、スチレン−メタクリル酸フェニル共重合体等）、スチレン−α−クロルアクリル酸メチル共重合体、スチレン−アクリロニトリル−アクリル酸エステル共重合体などのスチレン系樹脂、エポキシ樹脂、ポリエステル樹脂、ポリエチレン樹脂、ポリプロピレン樹脂、アイオノマー樹脂、ポリウレタン樹脂、ケトン樹脂、エチレン−エチルアクリレート共重合体、キシレン樹脂、ポリアミド樹脂、フェノール樹脂、ポリカーボネート樹脂、メラミン樹脂などがある。
本発明において、こらシリコーン樹脂に併用できるその余の樹脂は、該シリコーン樹脂１００重量部に対して１５０重量部以下であることが好ましく、１００重量部以下であることがより好ましい。
【００２４】
本キャリアには、帯電制御、芯材との密着性、また、ポリアミドとシリコーン樹脂との相溶性を向上する目的で、従来公知のアミノシランカップリング剤を用いることが好ましい。
【００２５】
本発明で用いられるアミノシランカップリング剤の例としては以下のようなものが挙げられる。
Ｈ_２Ｎ（ＣＨ_２）_３Ｓｉ（ＯＣＨ_３）_３……（ＭＷ：１７９．３）、
Ｈ_２Ｎ（ＣＨ_２）_３Ｓｉ（ＯＣ_２Ｈ_５）_３……（ＭＷ：２２１．４）、
Ｈ_２ＮＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）_２（ＯＣ_２Ｈ_５）……（ＭＷ：１６１．３）、
Ｈ_２ＮＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）（ＯＣ_２Ｈ_５）_２……（ＭＷ：１９１．３）、
Ｈ_２ＮＣＨ_２ＣＨ_２ＮＨＣＨ_２Ｓｉ（ＯＣＨ_３）_３……（ＭＷ：１９４．３）、
Ｈ_２ＮＣＨ_２ＣＨ_２ＮＨＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）（ＯＣＨ_３）_２……（ＭＷ：２０６．４）、
Ｈ_２ＮＣＨ_２ＣＨ_２ＮＨＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_３）_３……（ＭＷ：２２４．４）、
（ＣＨ_３）_２ＮＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）（ＯＣ_２Ｈ５）_２……（ＭＷ：２１９．４）、
（Ｃ_４Ｈ_９）_２ＮＣ_３Ｈ_６Ｓｉ（ＯＣＨ_３）_３……（ＭＷ：２９１．６）
【００２６】
また、アミノシラン化合物はその末端アミンをメトキシメチル化して用いることもできる。例えば、下記に示す構造の化合物は帯電付与性、経時帯電安定性の面から好ましく用いられる。
【００２７】
【化８】
（Ｒ_１Ｏ）_３ＳｉＲ_２ＮＨ（Ｒ_３ＯＲ_４） ……化合物Ａ
Ｒ_１：Ｃ１〜３のアルキル基
Ｒ_２：Ｃ１〜８の直鎖アルキレン鎖
Ｒ_３：Ｃ１〜２の直鎖アルキレン鎖
Ｒ_４：Ｃ１〜４のアルキル基
【００２８】
【化９】
（Ｒ_１Ｏ）_３ＳｉＲ_２ＮＨＲ_３ＮＨ（Ｒ_４ＯＲ_５） ……化合物Ｂ
Ｒ_１：Ｃ１〜３のアルキル基
Ｒ_２、Ｒ_３：Ｃ１〜８の直鎖アルキレン鎖
Ｒ_４：Ｃ１〜２の直鎖アルキレン鎖
Ｒ_５：Ｃ１〜４のアルキル基
【００２９】
上記化合物は、いずれも従来公知のアミノシラン化合物の末端アミンをアルコキシアルキル化して得られる。
【００３０】
アミノシラン化合物のアルコキシアルキル化は、例えば次のような方法を用いることができる。以下、メトキシメチル化の方法を例示する。
アミノシラン化合物をメタノール中に溶解し、この溶液に必要に応じて液性を塩基性に保ちながらホルムアルデヒド水溶液を滴下する。反応熱による温度過上昇が生じないよう、必要に応じて冷却しながら、３０℃〜６０℃で約１時間還流し、メトキシメチル化アミノシランの溶液が得られる。
一例としては、下記構造の化合物が好ましく用いられる。
【００３１】
【化１０】
（Ｈ_３ＣＯ）_３ＳｉＣ_３Ｈ_６ＮＨＣ_２Ｈ_４ＮＨ（ＣＨ_２ＯＣＨ_３）
こうした化合物の例としては、他にも例えば次のようなものが挙げられる。
【００３２】
【化１１】
ＣＨ_３ＯＣＨ_２ＨＮ（ＣＨ_２）_３Ｓｉ（ＯＣＨ_３）_３、
ＣＨ_３ＯＣＨ_２ＨＮ（ＣＨ_２）_３Ｓｉ（ＯＣ_２Ｈ_５）_３、
ＣＨ_３ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）_２（ＯＣ_２Ｈ_５）、
ＣＨ_３ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）（ＯＣ_２Ｈ_５）_２、
ＣＨ_３ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＮＨＣＨ_２Ｓｉ（ＯＣＨ_３）_３、
ＣＨ_３ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＮＨＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）（ＯＣＨ_３）_２、
ＣＨ_３ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＮＨＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_３）_３、
Ｃ_２Ｈ_５ＯＣＨ_２ＨＮ（ＣＨ_２）_３Ｓｉ（ＯＣＨ_３）_３、
Ｃ_２Ｈ_５ＯＣＨ_２ＨＮ（ＣＨ_２）_３Ｓｉ（ＯＣ_２Ｈ_５）_３、
Ｃ_２Ｈ_５ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）_２（ＯＣ_２Ｈ_５）、
Ｃ_２Ｈ_５ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）（ＯＣ_２Ｈ_５）_２、
Ｃ_２Ｈ_５ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＮＨＣＨ_２Ｓｉ（ＯＣＨ_３）_３、
Ｃ_２Ｈ_５ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＮＨＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）（ＯＣＨ_３）_２、
Ｃ_２Ｈ_５ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＮＨＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_３）_３、
Ｃ_３Ｈ_７ＯＣＨ_２ＨＮ（ＣＨ_２）_３Ｓｉ（ＯＣＨ_３）_３、
Ｃ_３Ｈ_７ＯＣＨ_２ＨＮ（ＣＨ_２）_３Ｓｉ（ＯＣ_２Ｈ_５）_３、
Ｃ_３Ｈ_７ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）_２（ＯＣ_２Ｈ_５）、
Ｃ_３Ｈ_７ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）（ＯＣ_２Ｈ_５）_２、
Ｃ_３Ｈ_７ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＮＨＣＨ_２Ｓｉ（ＯＣＨ_３）_３、
Ｃ_３Ｈ_７ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＮＨＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）（ＯＣＨ_３）_２、
Ｃ_３Ｈ_７ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＮＨＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_３）_３、
Ｃ_４Ｈ_９ＯＣＨ_２ＨＮ（ＣＨ_２）_３Ｓｉ（ＯＣＨ_３）_３、
Ｃ_４Ｈ_９ＯＣＨ_２ＨＮ（ＣＨ_２）_３Ｓｉ（ＯＣ_２Ｈ_５）_３、
Ｃ_４Ｈ_９ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）_２（ＯＣ_２Ｈ_５）、
Ｃ_４Ｈ_９ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）（ＯＣ_２Ｈ_５）_２、
Ｃ_４Ｈ_９ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＮＨＣＨ_２Ｓｉ（ＯＣＨ_３）_３、
Ｃ_４Ｈ_９ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＮＨＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＣＨ_３）（ＯＣＨ_３）_２、
Ｃ_４Ｈ_９ＯＣＨ_２ＨＮＣＨ_２ＣＨ_２ＮＨＣＨ_２ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_３）_３、
【００３３】
本発明に用いるアルコキシアルキル化ポリアミドは、非架橋状態ではその電気抵抗が低いため、画像形成時に地肌汚れや現像剤の帯電量の放置低下、温湿度による帯電量の変動などの不具合があるため、シリコーン樹脂との架橋構造を形成するための加熱工程により、残留するメトキシ成分を充分に分解する必要がある。こうして得られるキャリアの電気抵抗率は５０Ｖ／ｍｍにおけるＬｏｇＲが１４以上１７以下であり、２５０Ｖ／ｍｍにおける電気抵抗率のＬｏｇＲが８以上１６以下が好ましい範囲である。５０Ｖ／ｍｍにおける電気抵抗率のＬｏｇＲが１４より小さいと放置時の帯電量低下が大きく、また、温湿度による帯電量の変動が大きい。また、２５０Ｖ／ｍｍにおける電気抵抗率のＬｏｇＲが１６より大きいと、連続印刷時にキャリアのチャージアップによる画像濃度の低下が生じ好ましくない。
【００３４】
キャリアの電気抵抗を適正にするために、キャリア皮膜中に導電性物質を含有させることが可能である。ここでいう導電性物質とは、公知の導電性材料を用いることができる。導電性物質の例としては例えば、導電性ＺｎＯ、Ａｌ等の金属粉、各種の方法で作られたＳｎＯ_２及び種々の元素をドープしたＳｎＯ_２、ホウ化物、例えばＴｌＢ_２、ＺｎＢ_２、ＭｏＢ_２、炭化ケイ素及び導電性高分子（ポリアセチレン、ポリパラフェニレン、ポリ（パラ−フェニレンスルフィド）、ポリピロール）などがあるが、最も好ましくは導電性のカーボンブラックである。
【００３５】
また、先に記述したように、皮膜の補強の目的で皮膜中に他の硬質な微粒成分を含有させることができる。これらは、０．０１〜２０μｍの粒径、好ましくは０．０１〜１０μｍの粒径を有するモース硬度２以上の微粒成分であり得る。なかでも金属酸化物、無機酸化物粒子は均一な粒子径で、かつ皮膜の成分であるポリアミドと高い親和性が得られ、著しい皮膜の補強効果を示すため、好ましく用いられる。
こうした微粒子としては、従来公知の材料を単独、もしくは、混合して用いることが可能であり、代表的にはシリカ、酸化チタン、アルミナなどがある。なかでも、トナーを負極性に帯電させるため、アルミナ粒子は好ましく用いられる。
皮膜中に含有させる硬質微粒子の含有量として５％〜７０％が好ましい。含有量は用いる微粒子の粒子径、比表面積によって、適切に選ばれるが、５％未満では皮膜の耐磨耗効果が発現しにくく、７０％を超えると、微粒子の脱離が生じやすくなる。
【００３６】
皮膜中の微粒子含有量は、皮膜材料によっても適宜選択されるが、好ましくは１〜７０ｗｔ％の範囲である。１ｗｔ％以下では、皮膜強度の向上効果が充分ではなく、７０ｗｔ％を超えると、皮膜から微粒子の脱離が生じやすくなり、耐久性に不具合を生ずる場合がある。
用いる微粒子の平均粒径は、皮膜の厚さによるが、０．０１〜０．７μｍの範囲が好ましい。皮膜の厚さに対して用いる粒子径を適宜選択される。ここでいう皮膜厚さとは、キャリアの被覆層成分のうち、該微粒子成分を含まない樹脂成分の体積をキャリア芯材の表面積で除した値である。キャリア芯材の表面積はキャリア芯材の重量平均粒子径を求め、相当する球体の表面積とした求めた計算値とし、この皮膜厚さに対して含有する微粒子の平均粒径が０．０１〜１倍の粒径の範囲が好ましい。０．０１倍より小さいと、粒子充填による皮膜強度向上の効果が認められない。１倍より大きいと皮膜から粒子の離脱が生じやすくなる。
【００３７】
本発明で使用することができる皮膜を設けるキャリア芯材としては、従来公知のものが使用できる。例えば、鉄、コバルトなどの強磁性体、マグネタイト、ヘマタイト、Ｌｉ系フェライト、Ｍｎ−Ｚｎ系フェライト、Ｃｕ−Ｚｎ系フェライト、Ｎｉ−Ｚｎ系フェライト、Ｂａ系フェライト、Ｍｎ系フェライトなどが挙げられる。
フェライトとは一般に下記式で表わされる焼結体である。
【化１２】
（ＭＯ）ｘ（ＮＯ）ｙ（Ｆｅ_２Ｏ_３）ｚ
但し、ｘ＋ｙ＋ｚ＝１００ｍｏｌ％であって、Ｍ、Ｎはそれぞれ、Ｎｉ、Ｃｕ、Ｚｎ、Ｌｉ、Ｍｇ、Ｍｎ、Ｓｒ、Ｃａなどであり、２価の金属酸化物と３価の鉄酸化物との完全混合物から構成されている。
なかでもＭｎ−Ｍｇ−Ｓｒ系フェライト、Ｍｎ系フェライトなどが挙げられる。
【００３８】
キャリア芯材としては上記の磁性粒子が一般的であるが、より小粒径の磁性粉をフェノール樹脂、アクリル樹脂、ポリエステル樹脂などの公知の樹脂中に分散した形態を持つ、いわゆる樹脂分散キャリアも好適に用いられる。
【００３９】
本発明のキャリアとともに使用されるトナーとしては、バインダー樹脂としての熱可塑性樹脂を主成分とし、着色剤、微粒子、そして帯電制御剤、離型剤等を含むものである。また、一般公知の粉砕法、重合法等の各種のトナー製法により作製されたトナーを用いることができる。
【００４０】
バインダー樹脂としては、ポリスチレン、ポリビニルトルエン等のスチレン及びその置換体の単重合体、スチレン−ｐ−クロルスチレン共重合体、スチレン−プロピレン共重合体、スチレン−ビニルトルエン共重合体、スチレン−アクリル酸メチル共重合体、スチレン−アクリル酸エチル共重合体、スチレン−アクリル酸ブチル共重合体、スチレン−メタアクリル酸メチル共重合体、スチレン−メタアクリル酸エチル共重合体、スチレン−メタアクリル酸ブチル共重合体、スチレン−ｏ−クロルアクリル酸メチル共重合体、スチレン−アクリロニトリル共重合体、スチレン−ビニルメチルエーテル共重合体、スチレン−ビニルメチルケトン共重合体、スチレン−ブタジエン共重合体、スチレン−イソブチレン共重合体、スチレン−マレイン酸共重合体、スチレン−マレイン酸エステル共重合体等のスチレン系共重合体、ポリメチルメタクリレート、ポリブチルメタクリレート、ポリ塩化ビニル、ポリ酢酸ビニル、ポリエチレン、ポリプロピレン、ポリエステル、ポリウレタン、エポキシ樹脂、ポリビニルブチラール、ポリアクリル酸樹脂、ロジン、変性ロジン、テルペン樹脂、フェノール樹脂、脂肪族または芳香族炭化水素樹脂、芳香族系石油樹脂、塩素化パラフィン、パラフィンワックスなどが単独あるいは混合して使用できる。
【００４１】
ポリエステル樹脂としては、アルコールと酸との重縮合反応によって得られ、例えばアルコールとしては、ポリエチレングリコール、ジエチルグリコール、トリエチレングリコール、１，２−プロピレングリコール、１，３−プロピレングリコール、１，４−プロピレングリコール、ネオペンチルグリコール、１，４−ブテンジオールなどのジオール類、１，４−ビス（ヒドロキシメチル）シクロヘキサン、ビスフェノールＡ、水素添加ビスフェノールＡ、ポリオキシエチレン化ビスフェノールＡ、ポリオキシプロピレン化ビスフェノールＡなどのエーテル化ビスフェノール類、これらを炭素数３〜２２の飽和もしくは不飽和の炭化水素基で置換した２価のアルコール単量体、その他の２価のアルコール単量体、ソルビトール、１，２，３，６−ヘキサンテトロール、１，４−サルビタン、ペンタエリスリトール、ジペンタエリスリトール、トリペンタエリスリトール、ショ糖、１，２，４−ブタントリオール、１，２，５−ペンタントリオール、グリセロール、２−メチルプロパントリオール、２−メチル−１，２，４−ブタントリオール、トリメチロールエタン、トリメチロールプロパン、１，３，５−トリヒドロキシメチルベンゼン等の３価以上の高級アルコール単量体を挙げることができる。また、ポリエステル樹脂を得るために用いられるカルボン酸としては、例えばパルミチン酸、ステアリン酸、オレイン酸等のモノカルボン酸、マレイン酸、フマール酸、メサコン酸、シトラコン酸、テレフタル酸、シクロヘキサンジカルボン酸、コハク酸、アジピン酸、セバチン酸、マロン酸、これらを炭素数３〜２２の飽和もしくは不飽和の炭化水素基で置換した２価の有機酸単量体、これらの酸の無水物、低級アルキルエステルとリノレイン酸からの二量体、１，２，４−ベンゼントリカルボン酸、１，２，５−ベンゼントリカルボン酸、２，５，７−ナフタレントリカルボン酸、１，２，４−ナフタレントリカルボン酸、１，２，４−ブタントリカルボン酸、１，２，５−ヘキサントリカルボン酸、１，３−ジカルボン酸−２−メチル−２−メチレンカルボキシプロパン、テトラ（メチレンカルボキシル）メタン、１，２，７，８−オクタンテトラカルボン酸エンボール三量体、これらの酸の無水物等の３価以上の多価カルボン酸単量体を挙げることができる。
【００４２】
さらにエポキシ樹脂としては、ビスフェノールＡとエピクロルヒドリンとの重縮合物等があり、例えば、エポミックＲ３６２、Ｒ３６４、Ｒ３６５、Ｒ３６６、Ｒ３６７、Ｒ３６９（以上、三井石油化学工業社製）、エポトートＹＤ−０１１、ＹＤ−０１４、ＹＤ−９０４、ＹＤ−０１７（以上、東都化成社製）、エポコート１００２、１００４、１００７（以上、シェル化学社製）等の市販のものがある。
【００４３】
着色剤としては、カーボンブラック、ランプブラック、鉄黒、群青、ニグロシン染料、アニリンブルー、フタロシアニンブルー、ハンザイエローＧ、ローダミン６Ｇレーキ、カルコオイルブルー、クロムイエロー、キナクリドン、ベンジジンイエロー、ローズベンガル、トリアリルメタン系染料、モノアゾ系、ジスアゾ系、染顔料など、従来公知の染顔料を単独あるいは混合して使用し得る。
【００４４】
また、トナーは、通常使用されるトナーと同様に摩擦帯電性を制御する目的で含有せしめる薬剤を含有していても何ら不都合はない。そうした、いわゆる極性制御剤としては、例えばモノアゾ染料の金属錯塩、ニトロフミン酸及びその塩、サリチル酸、ナフトエ酸、ジカルボン酸のＣｏ、Ｃｒ、Ｆｅ、Ｚｎ等の金属錯体等を単独または混合して用いることができるが、これらに限定されるものではない。カラートナーに使用される極性制御剤は無色であることが必要であり、極性を有するポリマー型の極性制御性物質は好ましく用いられる。
【００４５】
本発明に使用されるトナーには流動性改質剤を添加することができる。流動性改質剤の例としては、有機樹脂微粒子、金属石鹸など、ポリテトラフロロエチレン系フッ素樹脂、ステアリン酸亜鉛のごとき滑剤、或いは酸価セリウム、炭化ケイ素などの研磨剤、一般に流動性改質の目的に用いられる公知の金属酸化物、代表的には酸化ケイ素、酸化チタン、酸化アルミニウムなどの酸化金属微粒子、およびその表面を疎水化した粒子などである。これらのいずれの微粉末もその表面を疎水化することは流動性の面で優れた効果をもたらす。表面を疎水化処理するためには、例えば、シランカップリング剤やシリル化剤として一般に知られる珪素化合物を粒子表面と接触、反応させることができる。
【００４６】
疎水化剤としては例えばクロロシラン類としては代表的にトリクロロシラン、メチルジクロロシラン、ジメチルジクロロシラン、トリメチルクロロシラン、エチルジクロロシラン、ジエチルクロロシラン、トリエチルクロロシラン、プロピルジクロロシラン、ジプロピルジクロロシラン、トリプロピルクロロシランなどアルキルクロロシラン、フェニルクロロシランなど。そのフッソ置換体としてフルオロアルキルクロロシラン、パーフルオロアルキルクロロシランの類。シリルアミン類としては、代表的にヘキサメチルジシラザン、ジエチルアミノトリメチルシラン、ジエチルアミノトリメチルシランなど。シリルアミド類としては、代表的にＮ，Ｏ−ビストリメチルシリルアセトアミド、Ｎ−トリメチルシリルアセトアミド、ビストリメチルシリルトリフルオロアセトアミドなど。また、アルコキシシラン類として、メチルトリアルコキシシラン、ジメチルジアルコキシシラン、トリメチルアルコキシシラン、エチルジアルコキシシラン、ジエチルアルコキシシラン、トリエチルアルコキシシラン、プロピルトリアルコキシシラン、ジプロピルジアルコキシシラン、トリプロピルアルコキシシランなど、アルキルクロロシランや、フェニル基を有するフェニルアルコキシシランなど。また、そのフッソ置換体としてフルオロアルキルアルコキシシランの類、パーフルオロアルキルアルコキシシランの類、シリコーンオイルとして、ジメチルシリコーンオイル、およびその誘導体、フッ素置換体、ジシロキサン、ヘキサメチルジシロキサンなどシロキサンの類など、一般公知の疎水化剤として用いられる化合物が使用できる。
【００４７】
本発明に使用されるトナーは必要に応じて磁性粉末を含有せしめ、磁性トナーとすることも可能である。
用いられる磁性粉体としては、マグネタイト、マグヘマタイトなどの磁性酸化鉄粒子粉末、鉄以外の金属（Ｍｎ、Ｎｉ、Ｚｎ、Ｍｇ、Ｃｕ等）を一種または二種以上含有するスピネルフェライト粒子粉末、バリウムフェライト等のマグネトプランバイト型フェライト粒子粉末、表面に酸化層を有する鉄およびその合金の微粒子粉末等を用いることができる。また、ヘマタイト、ゲータイト、ウスタイトなどの非磁性酸化鉄粒子粉末を用いることもでき、場合によっては前記磁性酸化鉄粒子と混合して用いることもできる。
好ましくはマグネタイト、マグヘマタイト等の磁性酸化鉄粒子粉末または、ヘマタイト、ゲータイトなどの非磁性酸化鉄粒子粉末である。その粒子形状は、粒状、球状、針状のいずれであっても良い。前記粒子の粒子径は、０．０５〜５μｍであることが好ましく、トナー中に数％〜７０重量％含有させて、磁性トナーを得ることができる。
【００４８】
【実施例】
以下、本発明を実施例により具体的に説明する。なお、本発明はここに例示される実施例に限定されるものではない。
＜化合物１の製造例＞
メタノール１０部に下記アミノシランカップリング剤１０部を溶解した。この液を氷浴中で冷却し、液温が３０℃以下を保ちながら、ホルムアルデヒド（３７％）液４部を滴下した。混合時の発熱が終了後、２５℃で１時間攪拌し化合物１の溶液を得た。
【化１３】
ＮＨ_２Ｃ_３Ｈ_６Ｓｉ（ＯＣＨ_３）_３
【００４９】
＜化合物２の製造例＞
メタノール１０部に下記アミノシランカップリング剤１０部を溶解した。この液を氷浴中で冷却し、液温が３０℃以下を保ちながら、ホルムアルデヒド（３７％）液４部を滴下した。混合時の発熱が終了後、２５℃で１時間攪拌し化合物２の溶液を得た。
【化１４】
ＮＨ_２Ｃ_２Ｈ_４ＮＨＣ_３Ｈ_６Ｓｉ（ＯＣＨ_３）_３
【００５０】
＜製造例１＞
還流器を備えた攪拌可能なガラス容器にメトキシメチル化ポリアミド（ナガセケムテック株式会社製 ＥＦ３０Ｔ）２０部、クエン酸１部、メタノール８０部を入れ、ウォーターバスで６０℃に加熱、攪拌して、メトキシメチル化ポリアミドメタノール溶液を作成した。
この溶液にメチルシリコーン樹脂トルエン溶液（分子量１５０００、固形分２０ｗｔ％、硬化温度１２０℃）１００部、トルエン１００部、イソプロパノール１００部、カーボンブラック（ＢＰ２０００）１部を加え、ホモジナイザーで分散した。得られた分散液に、触媒としてジブチルスズジアセテート、トルエン溶液（４０ｗｔ％溶液）１部、γアミノエチルアミノプロピルトリメトキシシラン０．８部を加え、アジピン酸１部を加え、攪拌し、コート液を得た。
この液体を流動床乾燥装置にて重量平均径３８μｍ、１０００ガウスにおける磁気モーメント７８ｅｍｕ／ｇのフェライト芯材に塗布して樹脂皮膜を設けた。得られた粉体は、２１０℃にて２時間加熱乾燥し、皮膜厚さ０．５９μｍのキャリアＡを得た。このキャリアの電気抵抗率のＬｏｇＲは１３．８Ωｃｍ（５０Ｖ／ｍｍ）、１２．９Ωｃｍ（２５０Ｖ／ｍｍ）であった。
【００５１】
＜製造例２＞
製造例１においてγアミノエチルアミノプロピルトリメトキシシランに代えて、化合物１の製造例で作成した化合物１溶液を２部用いる以外は、すべて同様にしてキャリアＢを得た。
皮膜の厚さは０．６１μｍ、電気抵抗率のＬｏｇＲは１４．１Ωｃｍ（５０Ｖ／ｍｍ）、１３．８Ωｃｍ（２５０Ｖ／ｍｍ）であった。
【００５２】
＜製造例３＞
製造例２において化合物１に代えて、化合物２溶液を用いる以外は、すべて同様にしてキャリアＣを得た。
皮膜の厚さは０．６１μｍ、電気抵抗率のＬｏｇＲは１４．１Ωｃｍ（５０Ｖ／ｍｍ）、１３．８Ωｃｍ（２５０Ｖ／ｍｍ）であった。
【００５３】
＜製造例４＞
還流器を備えた攪拌可能なガラス容器にメトキシメチル化ポリアミド（ナガセケムテック株式会社製 ＥＦ３０Ｔ）２０部、クエン酸１部、メタノール８０部を入れ、ウォーターバスで６０℃に加熱、攪拌して、メトキシメチル化ポリアミドメタノール溶液を作成した。
この溶液に平均粒子径０．３μｍのアルミナ粒子８部を加え、ホモジナイザーで攪拌した。
この溶液を攪拌しながら、メチルシリコーン樹脂トルエン溶液（分子量１５０００、固形分２０ｗｔ％）１００部、トルエン１００部、イソプロパノール１００部、カーボンブラック（ＢＰ２０００）１部を徐々に加え、更にホモジナイザーで分散した。得られた分散液に、触媒としてジブチルスズジアセテート、トルエン溶液（固形分濃度４０ｗｔ％）１部、先の化合物２の溶液２部、アジピン酸１部を加え、攪拌し、コート液を得た。
この液体を流動床乾燥装置にてフェライト芯材に塗布して樹脂皮膜を設けた。
得られた粉体は、２１０℃にて２時間加熱乾燥し、皮膜厚さ０．５９μｍのキャリアＤを得た。このキャリアの電気抵抗率のＬｏｇＲは１３．８Ωｃｍ（５０Ｖ／ｍｍ）、１２．９Ωｃｍ（２５０Ｖ／ｍｍ）であった。
【００５４】
＜製造例５＞
製造例４においてアジピン酸１部をパラトルエンスルホン酸のトルエン溶液（固形分濃度４０ｗｔ％）１．２５部、安息香酸０．５部とする以外は全て同様にしてキャリアＥを得た。このキャリアの電気抵抗率のＬｏｇＲは１４．０Ωｃｍ（５０Ｖ／ｍｍ）、１３．０Ωｃｍ（２５０Ｖ／ｍｍ）であった。
【００５５】
＜製造例６＞
製造例４において、用いるアルミナ粒子を、平均粒子径０．０１μｍのアルミナ粒子８部とする以外は全て同様にしてキャリアＦを得た。
【００５６】
＜製造例７＞
製造例１においてメチルシリコーン樹脂に代えてメチルシリコーン樹脂トルエン溶液（分子量８００、固形分２０ｗｔ％、硬化温度４５℃）を用いる以外は製造例１と全て同様にして、キャリアＧを得た。
【００５７】
＜製造例８＞
製造例１においてメチルシリコーン樹脂に代えてメチルフェニルシリコーン樹脂トルエン溶液（分子量２０００、固形分２０ｗｔ％、硬化温度２２０℃）を用いる以外は製造例１と全て同様にして、キャリアＨを得た。このキャリアは焼成後ブロック状に硬化し、これを粉砕してキャリア粒子を得た。
【００５８】
実施例１
製造例１で作成したキャリアＡ９３部とＩＰＳＩＯ Ｃｏｌｏｒ８０００用マゼンタトナー７部を混合し、現像剤とし、これをＩＰＳＩＯ Ｃｏｌｏｒ８０００に装填して、画像面積率１２％、文字画像パターンを用いて１千枚の連続プリントを行なった。
現像剤の一部を取り出し、続けて１０万枚の連続プリント試験を行なった。
【００５９】
使用開始前、１千枚プリント後、連続プリント終了時のそれぞれ現像剤の帯電量を測定した。
また、１０万枚プリント終了時の画像の地肌汚れ、現像剤の帯電量を同様に評価した。
現像剤の帯電量は、現像装置のスリーブ上から少量の現像剤を採取し、ブローオフ法に基づいて行なった。
キャリアの膜厚は、キャリアを破砕し、走査型電子顕微鏡で断面像を観察して求めた。
地肌汚れの評価は目視評価で４段階の評価とした。
【００６０】
実施例２〜６及び比較例１、２
実施例１においてキャリアＡに換えてキャリアＢ〜Ｈをそれぞれ用いて、同様に現像剤とし画像評価を行なった。結果を同様に表に示す。
【００６１】
【表１】

【００６２】
【発明の効果】
以上、詳細かつ具体的な説明より明らかなように、本発明は、長期にわたり安定した帯電性を有し、皮膜耐磨耗性に優れた安定性の高いキャリアを提供することができるという優れた効果を奏する。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a carrier for developing an electrostatic latent image used in a two-component developer used in electrophotography and electrostatic recording.
[0002]
[Prior art]
In recent years, printing apparatuses using an electrophotographic method have been rapidly colorized, and the printing speed has been increased.
Conventionally, the two-component development method is suitable for high-speed printing and has been widely used in full-color image forming apparatuses because non-magnetic toner is easy to handle. However, the full-color printing apparatus needs to include a plurality of developing devices in the apparatus, and has disadvantages such as an increase in the size and weight of the apparatus as compared with a monochrome machine. In particular, the two-component developing device needs to be equipped with a developer storage volume and a stirring mechanism in addition to the toner as compared with the one-component developing device. To reduce the size of the developing unit, a small amount of developer is required. It was essential.
[0003]
The carrier in the developer is repeatedly subjected to mechanical friction and impact in the developing device by friction with toner, a rubbing member such as a sleeve and a blade, a regulating member and a stirring and conveying member such as a screw and paddle. Decreasing the amount of developer means an increase in the chance of friction between the toner and the carrier per the number of printed sheets and an increase in the frequency of the carrier passing through the developing portion. As a result, the fatigue of the carrier in the developing unit rapidly proceeds. . Combined with higher printing speed, the carrier is durable, especially with high wear resistance on the surface of the carrier layer, and prevents the carrier surface from being contaminated (spent) by toner and other components. Maintaining sex is becoming more important than ever.
[0004]
In recent digital copying machines and printers, negative-positive development is often performed using a negatively charged photoconductor, and negatively charged toner is often used. Many examples are known in which a carrier film contains an organic compound containing nitrogen to negatively charge the toner.
Examples thereof include an example in which an aminosilane coupling agent is mixed with a silicone resin, an example in which a certain type of acid amide is internally added, and a method in which an amino compound such as melamine or guanamine or a derivative thereof is internally added.
[0005]
As an example of using such a nitrogen-containing organic material as a coating material, an example of using polyamide has been conventionally disclosed (for example, Patent Document 1).
However, polyamide resins typified by nylon are generally preferred materials for imparting negative chargeability to toners, but many of them are poor in solvent solubility, so that layers can be formed by a simple method such as applying a solution. There are also problems that it is difficult to do this, and that the wear resistance of the polyamide itself is not sufficient.
[0006]
Thus, as an example of using a polyamide solubilized in a solvent, examples in which a hydrogen atom of an amide bond is alkoxyalkylated are disclosed (for example, Patent Documents 2 to 6), and an example using a graft polymer having such a polyamide in the main chain is disclosed. (For example, see Patent Documents 7 and 8), however, a film using such a polyamide as a main component is not sufficient in the abrasion resistance of the film.
Among them, the aminosilane compound is preferably used because it gives a strong positive charge to the carrier and a stable charge amount against temperature and humidity changes, but on the other hand, due to its high reactivity and self-condensation, Depending on the film formation conditions, segregation on the surface and localization within the film are likely to occur, charging capacity fluctuations may occur within a relatively short time after the start of carrier use, and temperature and humidity during the coating process. There is a problem that the charging ability varies depending on the atmosphere.
Further, it is shown that N-methoxymethylated polyamide is used and a surface resistance of 13 Ω · cm or less is used, and the membrane resistance can be lowered by partially methoxymethylating the polyamide. Although it is shown (for example, refer to Patent Document 9), the resistance reduction of the carrier due to the residual methoxy group is caused by the high water affinity of the methoxy group, and the environmental variability of the charge amount, the developer charge amount There was a problem such as a large decrease in storage.
[0007]
[Patent Document 1]
JP-A-49-115549 (Claims on page 1, lower left column, lines 3 to 6; page 2, upper right column, line 19 to lower left column, line 16)
[Patent Document 2]
Japanese Patent Laid-Open No. 1-118150 (1st page, lower left column, line 4 to end line)
[Patent Document 3]
Japanese Patent Application Laid-Open No. 1-1118151 (claim 1 in the first page, lower left column, fourth line to upper right column, first line)
[Patent Document 4]
Japanese Patent Laid-Open No. 4-188160 (1st page, lower left column, claims 4-7), 3rd page, upper right column, 6th-12th line, 3rd page, lower right column 4th to 14th lines)
[Patent Document 5]
JP 2001-201894 A (2nd page, first column, line 1 to line 45)
[Patent Document 6]
Japanese Patent No. 3043390 (1st page, 1st column, 1st line to 9th line, claim 1, 3rd page, 5th column, 8th line to 13th line, 3rd page, 6th column, 2nd page) (Lines 8 to 8, page 3, column 6, lines 19 to 34)
[Patent Document 7]
Japanese Patent No. 2835971 (Claims on page 1, column 1, line 1 to page 2, line 11; page 3, column 5, line 41 to page 4, column 7, line 7, line 22) Eye)
[Patent Document 8]
Japanese Patent No. 2835972 (Claims on page 1, column 1, line 1 to column 2, line 10), page 3, column 6, lines 13 to 43)
[Patent Document 9]
Japanese Patent No. 0923192 (Claims on page 1, column 1, line 1 to column 2, line 9), page 2, column 4, line 42 to page 3, column 6, column 6, line 7 Eyes, page 3, column 5, line 46 to column 6, line 35)
[0008]
[Problems to be solved by the invention]
An object of the present invention is to solve the above problems. That is, an object is to provide a carrier that has a stable charge imparting ability for a long period of time, is excellent in wear resistance and durability of a film, and has stable chargeability regardless of the use atmosphere. Another object of the present invention is to provide a carrier that maintains a stable charge generation ability from the beginning of use of the developer and has excellent durability.
[0009]
[Means for Solving the Problems]
  The above-described problems are solved by (1) “a form having a film on the surface of fine powder having magnetism, (i) N-alkoxyalkylated polyamide, and (ii) the N-alkoxyalkylated polyamide. A crosslinked product obtained from a mixture of resins capable of reacting with the resin, wherein the reactable resin of (ii) has at least a silanol group and / or a hydrolyzable group, and a gelling temperature of 60 ° C. or higher ,170(2) “The silicone resin is a methyl silicone compound having a molecular weight of 1,000 to 100,000”. The carrier for developing an electrostatic latent image according to item (1), (3) “the film contains an aminosilane compound and / or a condensate thereof,” (1) or (2 The electrostatic latent image developing carrier according to item (4), (4) "Static film according to item (1) or (2), wherein the film contains a compound A having the following structure: Carrier for developing electrostatic latent image;
[Formula 4]
(R₁O)₃SiR₂NH (R₃OR₄) Compound A
R₁: C1-3 alkyl group
R₂: C1-8 linear alkylene chain
R₃: C1-2 linear alkylene chain
R₄: C1-4 alkyl group ", (5)" For electrostatic latent image development according to item (1) or (2), wherein the film contains compound B having the following structure " Career;
[Chemical formula 5]
(R₁O)₃SiR₂NHR₃NH (R₄OR₅) …… Compound B
R₁: C1-3 alkyl group
R₂, R₃: C1-8 linear alkylene chain
R₄: C1-2 linear alkylene chain
R₅: C1-4 alkyl group ", (6)" The electrostatic latent image developing carrier according to item (5), wherein the compound B is a compound having the following structure;
[Chemical 6]
(H₃CO)₃SiC₃H₆NHC₂H₄NH (CH₂OCH₃) ", (7)" The electrostatic latent image developing carrier according to (1) above, wherein the polyamide is an N-methoxymethylated polyamide having a methoxylation rate of 20% to 70% ", (8) The electrostatic latent image developing carrier according to any one of (1) to (5) above, wherein the coating contains a solid organic acid having a boiling point of 100 ° C. or higher. (9) “LogR of electrical resistivity at an applied electric field of 50 V / mm is 14 or more, and LogR of electrical resistivity at 250 V / mm is 16 or less. The carrier for developing an electrostatic latent image according to any one of items (8), (10), and a volume resistivity of 10 in the film.^-2Ω · cm to 10⁸The electrostatic latent image developing carrier according to any one of (1) to (9) above, which contains a low resistance substance of Ω · cm ”, (11)“ in the coating The carrier for developing an electrostatic latent image according to any one of items (1) to (10), comprising oxide fine particles of any one of Si, Ti and Al ”, (12) The carrier for developing an electrostatic latent image according to item (11), wherein the content of oxide fine particles in the film is in the range of 5% to 70% by weight of the amount of the film resin. (13) The electrostatic latent image developing carrier according to item (11), wherein the oxide fine particles are alumina fine particles.", (14) “(13) wherein the alumina fine particles have an average particle diameter of 0.01 μm to 0.7 μm.In termsThis is achieved by the "electrostatic latent image developing carrier" described.
[0010]
That is, the carrier for electrostatic latent image development of the present invention can impart excellent positive charging property of polyamide and strength of the coating to the carrier coating. In addition, by appropriately selecting the curing temperature of the silicone resin used in combination with the polyamide, it prevents the separation of the coating during coating and the thermal decomposition of the polyamide during coating curing, providing a more uniform and stable charge carrier over time. Obtainable. In addition, when the methyl silicone resin is used in combination with methoxymethylated polyamide, the compatibility between the resins is poor, so the film strength may be reduced, but by using an aminosilane compound, the compatibility between the resins, The film strength is improved. Furthermore, by using a compound having a structure in which the primary amine at the terminal of aminosilane is methoxymethylated, the charge generation ability is high, but the reactivity is high, but the amount of primary amine is controlled appropriately and Charging stability can be improved while incorporating a secondary amine and suppressing the carrier surface from being deteriorated by a toner or a chemical substance derived from the use atmosphere.
[0011]
  Hereinafter, embodiments of the present invention will be described.
  The carrier of the present invention has a resin layer on the surface, and the resin layer contains a polycondensate obtained from a mixture of at least two kinds of resins.
  The resin constituting the resin layer is (1) a solvent-solubilized polyamide obtained by alkoxyalkylating a hydrogen atom of an amide bond in the main chain, and (2) a gelation temperature of 60 ° C. as another type of resin. more than,170Contains a silicone resin at a temperature of ℃ or less.
  The silicone resin has hydrolyzable groups such as silanol or various alkoxy and oximes, and has a crosslinked structure between itself and the alkoxide of polyamide or active hydrogen of amide bond by the generated hydroxyl group. It is possible to form. A resin layer in which at least the resin containing polyamide and silicone is mixed is formed on the surface of the magnetic powder and heated to form a cured film of a polycondensate between the resins. At this time, since the alkoxyalkylated polyamide to be used is applied and dried as a lower alcohol solution, if the silicone resin gels below the boiling point of the alcohol used as the coating solvent, the silicone and the polyamide are separated at the time of film formation, and the film is uneven. Tends to occur. That is, the gelation temperature of the silicone resin is preferably higher than the vicinity of the boiling point of methanol, which is a good solvent for the polyamide, and preferably 60 ° C. or higher. On the other hand, when the gelation temperature exceeds 250 ° C., the thermal decomposition of the polyamide is unavoidable during the gelation, which is not preferable. It is more preferable that the softening temperature of a typical polyamide is about 170 ° C., and the gelation reaction of silicone proceeds at 170 ° C. or lower. The gelation temperature as used herein refers to a silicone glass solid content of 1 g dropped on a glass slide set on a hot plate set at a predetermined temperature, heated, and after 60 seconds from dropping, the glass slide is tilted to 45 °, The temperature at which the resin does not flow down.
[0012]
Examples of the polyamide used in the present invention include solvent-solubilized polyamides in which the hydrogen atom of the amide bond of the main chain is alkoxyalkylated. Using this, a lower alcohol solution of the polyamide and a silanol-condensable silicone resin are used. A coating liquid is prepared by mixing and dissolving one or a plurality of resins having reactivity with polyamide and, if necessary, a catalyst for promoting cross-linking, and coating, drying, and heat-curing on a magnetic carrier core material. To form a film. The term “polyamide” as used herein refers to a general polyamide obtained from a dicarboxylic acid and a diamine, or a polyamide formed by ring-opening condensation polymerization of various lactams.
These polyamide main chains and polyamides that are partially alkoxyalkylated with NH bond active hydrogen atoms to give alcohol solubility and thermosetting properties are used. For example, a method for N-methoxymethylating polyamide is performed by dissolving polyamide such as formic acid and reacting with formalin in an acidic atmosphere in the presence of a lower alcohol such as methanol.
[0013]
Since the methoxymethylated polyamide thus obtained has improved solubility in lower alcohols such as methanol according to the reaction ratio, it is easy to form a film by applying a solution to the carrier surface. In addition, the polyamide exhibits rubber elasticity in an uncrosslinked state, and is heated in the presence of an appropriate acid catalyst to condense between the self methoxy group and the active hydrogen of the amide bond of the main chain, Crosslink and increase hardness. This is mixed with silanol-condensable silicone, applied as a carrier film, and heated in the presence of an acid catalyst to form a film having a cross-linked structure between silicone and polyamide.
[0014]
The alkylalkoxylation treatment for solubilizing the polyamide constituting the film is preferably about 20 to 70 mol% in terms of the substitution rate of active hydrogen of the amide bond. If the amount is less than this, the alcohol solubility is poor, and there are problems such as precipitation during film formation and segregation after film formation. If it exceeds 70%, the film density decreases and the wear resistance deteriorates. The same applies to the case where metal oxide particles are added.
[0015]
In order to sufficiently cure the film, it is preferable to heat under acidic conditions, but as the acid catalyst to be used, it is preferable to contain an organic solid acid in the coating agent solution. When the boiling point of the catalyst is less than 100 ° C., the catalyst evaporates during drying of the film, and the film cannot be sufficiently cured by the additional heat for forming a crosslink.
Examples of acid catalysts include lactic acid, lauric acid, crotonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, oxalic acid, succinic acid, glycolic acid, malonic acid, maleic acid, itaconic acid , Representative organic acids such as tartaric acid, benzoic acid, phthalic acid, trimellitic acid, benzyl sulfonic acid, toluene sulfonic acid, inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, hypophosphorous acid, etc. Although it can be used, in order to appropriately advance the crosslinking reaction, it is sufficient to select one having at least one acid catalyst having a boiling point of 100 ° C. or higher. Of these, polybasic carboxylic acid compounds having a dibasic acid or higher are preferably used.
[0016]
In the present invention, the coating strength is further increased by mixing metal oxide particles in the coating. For example, the metal oxide particles are introduced into the film as follows.
The solubilized polyamide is dissolved in methanol with heating as necessary.
Metal oxide particles are mixed in the dissolved solution and uniformly dispersed using a dispersing device such as a homogenizer.
The dispersion solution is mixed with a separately prepared non-aqueous solvent solution of silanol condensable silicone, and similarly stirred with a homogenizer, and a charge adjusting agent and a resistance adjusting agent are appropriately mixed and applied to the carrier core material.
[0017]
Here, examples of polyamides used in the present invention include, for example, 1,6-hexanediamine, 1,8-octadiamine, linear alkyldiamine such as 1,2-propanediamine, branched alkyldiamine, Examples of aromatic diamines such as m-phenylenediamine, P-phenylenediamine, o-phenylenediamine, toluene-2,5-diamine, N-phenyl-p-phenyldiamine, and 4,4-diaminodiphenylamine, and carboxylic acids include , Maleic acid, fumaric acid, mesaconic acid, citraconic acid, terephthalic acid, isophthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, dodecanoic acid, malonic acid and other polyhydric fatty acids, aromatic dicarboxylic acids, various A condensation polymer such as an amino acid, Styrenesulfonate, also amino self condensation polymer such as a ring-opening polycondensation or aminoundecanoic acid various caprolactam, and the like thereof mutual copolymers.
[0018]
As the silicone resin used in combination with polyamide, a conventionally known resin composition can be used. A silicone resin containing a repeating unit represented by the following formula can be preferably used.
[0019]
[Chemical 7]

[0020]
In the above formula, R₁Represents a hydrogen atom, a halogen atom, a hydroxy group, a methoxy group, a lower alkyl group having 1 to 4 carbon atoms, or an aryl group (phenyl group, tolyl group, etc.), and R₂Represents an alkylene group having 1 to 4 carbon atoms or an arylene group (such as a phenylene group).
[0021]
Examples of such resins include, for example, KR271, KR272, KR282, KR252, KR255, KR152 (manufactured by Shin-Etsu Chemical Co., Ltd.), SR2400, SR2406 (manufactured by Toray Dow Corning Silicone) and the like as straight silicone resins. Among them, methyl silicone resin is preferably used for reasons such as low spent property and small environmental fluctuation of charge amount.
The molecular weight of the silicone resin is about 1,000 to 100,000, preferably about 1,000 to 20,000. When the molecular weight of the resin used is greater than 100,000, the coating solution viscosity increases excessively during coating, and the coating film uniformity may not be sufficiently obtained, or the coating density may not sufficiently increase after curing. If it is less than 1000, defects such as brittleness of the cured film tend to occur.
[0022]
In addition, modified silicone resins are also preferably used, and examples thereof include epoxy-modified silicone, acrylic-modified silicone, phenol-modified silicone, urethane-modified silicone, polyester-modified silicone, and alkyd-modified silicone. Specific examples of the modified silicone resin include epoxy modified product: ES-1001N, acrylic modified silicone: KR-5208, polyester modified product: KR-5203, alkyd modified product: KR-206, urethane modified product: KR-305 ( As mentioned above, Shin-Etsu Chemical Co., Ltd.), epoxy-modified product: SR2115, alkyd-modified product: SR2110 (manufactured by Toray Dow Corning Silicone), and the like.
In the present invention, the use ratio of (i) N-alkoxyalkylated polyamide and (ii) these silicone resins as a resin capable of reacting with the N-alkoxyalkylated polyamide resin is 10:90 parts to 90:10 parts. And more preferably 20:80 parts to 50:50.
[0023]
Furthermore, in the present invention, as the resin for coating the surface of the carrier core particles, the following can be used alone or mixed with the silicone resin.
Polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, Styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer) Polymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylate copolymer (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, Styrene-phenyl methacrylate copolymer, etc.) Styrene resins such as styrene-α-chloromethyl acrylate copolymer, styrene-acrylonitrile-acrylate copolymer, epoxy resin, polyester resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, ketone resin, ethylene -Ethyl acrylate copolymer, xylene resin, polyamide resin, phenol resin, polycarbonate resin, melamine resin and the like.
In the present invention, the remaining resin that can be used in combination with the silicone resin is preferably 150 parts by weight or less, more preferably 100 parts by weight or less, relative to 100 parts by weight of the silicone resin.
[0024]
For this carrier, it is preferable to use a conventionally known aminosilane coupling agent in order to improve charge control, adhesion to the core material, and compatibility between polyamide and silicone resin.
[0025]
Examples of the aminosilane coupling agent used in the present invention include the following.
H₂N (CH₂)₃Si (OCH₃)₃...... (MW: 179.3),
H₂N (CH₂)₃Si (OC₂H₅)₃...... (MW: 221.4),
H₂NCH₂CH₂CH₂Si (CH₃)₂(OC₂H₅) …… (MW: 161.3),
H₂NCH₂CH₂CH₂Si (CH₃) (OC₂H₅)₂...... (MW: 191.3),
H₂NCH₂CH₂NHCH₂Si (OCH₃)₃...... (MW: 194.3),
H₂NCH₂CH₂NHCH₂CH₂CH₂Si (CH₃) (OCH₃)₂(MW: 206.4),
H₂NCH₂CH₂NHCH₂CH₂CH₂Si (OCH₃)₃...... (MW: 224.4),
(CH₃)₂NCH₂CH₂CH₂Si (CH₃) (OC₂H5)₂...... (MW: 219.4),
(C₄H₉)₂NC₃H₆Si (OCH₃)₃...... (MW: 291.6)
[0026]
An aminosilane compound can also be used after methoxymethylating its terminal amine. For example, a compound having the structure shown below is preferably used from the viewpoint of charge imparting property and charging stability with time.
[0027]
[Chemical 8]
(R₁O)₃SiR₂NH (R₃OR₄) Compound A
R₁: C1-3 alkyl group
R₂: C1-8 linear alkylene chain
R₃: C1-2 linear alkylene chain
R₄: C1-4 alkyl group
[0028]
[Chemical 9]
(R₁O)₃SiR₂NHR₃NH (R₄OR₅) …… Compound B
R₁: C1-3 alkyl group
R₂, R₃: C1-8 linear alkylene chain
R₄: C1-2 linear alkylene chain
R₅: C1-4 alkyl group
[0029]
Any of the above compounds can be obtained by alkoxyalkylating a terminal amine of a conventionally known aminosilane compound.
[0030]
For example, the following method can be used for alkoxyalkylation of the aminosilane compound. Hereinafter, the method of methoxymethylation is illustrated.
An aminosilane compound is dissolved in methanol, and an aqueous formaldehyde solution is dropped into this solution while keeping the liquidity basic as necessary. The solution is refluxed at 30 ° C. to 60 ° C. for about 1 hour with cooling as necessary so as not to cause an excessive increase in temperature due to heat of reaction, whereby a solution of methoxymethylated aminosilane is obtained.
As an example, a compound having the following structure is preferably used.
[0031]
[Chemical Formula 10]
(H₃CO)₃SiC₃H₆NHC₂H₄NH (CH₂OCH₃)
Other examples of such compounds include the following.
[0032]
Embedded image
CH₃OCH₂HN (CH₂)₃Si (OCH₃)₃,
CH₃OCH₂HN (CH₂)₃Si (OC₂H₅)₃,
CH₃OCH₂HNCH₂CH₂CH₂Si (CH₃)₂(OC₂H₅),
CH₃OCH₂HNCH₂CH₂CH₂Si (CH₃) (OC₂H₅)₂,
CH₃OCH₂HNCH₂CH₂NHCH₂Si (OCH₃)₃,
CH₃OCH₂HNCH₂CH₂NHCH₂CH₂CH₂Si (CH₃) (OCH₃)₂,
CH₃OCH₂HNCH₂CH₂NHCH₂CH₂CH₂Si (OCH₃)₃,
C₂H₅OCH₂HN (CH₂)₃Si (OCH₃)₃,
C₂H₅OCH₂HN (CH₂)₃Si (OC₂H₅)₃,
C₂H₅OCH₂HNCH₂CH₂CH₂Si (CH₃)₂(OC₂H₅),
C₂H₅OCH₂HNCH₂CH₂CH₂Si (CH₃) (OC₂H₅)₂,
C₂H₅OCH₂HNCH₂CH₂NHCH₂Si (OCH₃)₃,
C₂H₅OCH₂HNCH₂CH₂NHCH₂CH₂CH₂Si (CH₃) (OCH₃)₂,
C₂H₅OCH₂HNCH₂CH₂NHCH₂CH₂CH₂Si (OCH₃)₃,
C₃H₇OCH₂HN (CH₂)₃Si (OCH₃)₃,
C₃H₇OCH₂HN (CH₂)₃Si (OC₂H₅)₃,
C₃H₇OCH₂HNCH₂CH₂CH₂Si (CH₃)₂(OC₂H₅),
C₃H₇OCH₂HNCH₂CH₂CH₂Si (CH₃) (OC₂H₅)₂,
C₃H₇OCH₂HNCH₂CH₂NHCH₂Si (OCH₃)₃,
C₃H₇OCH₂HNCH₂CH₂NHCH₂CH₂CH₂Si (CH₃) (OCH₃)₂,
C₃H₇OCH₂HNCH₂CH₂NHCH₂CH₂CH₂Si (OCH₃)₃,
C₄H₉OCH₂HN (CH₂)₃Si (OCH₃)₃,
C₄H₉OCH₂HN (CH₂)₃Si (OC₂H₅)₃,
C₄H₉OCH₂HNCH₂CH₂CH₂Si (CH₃)₂(OC₂H₅),
C₄H₉OCH₂HNCH₂CH₂CH₂Si (CH₃) (OC₂H₅)₂,
C₄H₉OCH₂HNCH₂CH₂NHCH₂Si (OCH₃)₃,
C₄H₉OCH₂HNCH₂CH₂NHCH₂CH₂CH₂Si (CH₃) (OCH₃)₂,
C₄H₉OCH₂HNCH₂CH₂NHCH₂CH₂CH₂Si (OCH₃)₃,
[0033]
Since the alkoxyalkylated polyamide used in the present invention has a low electrical resistance in the non-crosslinked state, there are problems such as background stains during image formation and a decrease in the charge amount of the developer, and a change in the charge amount due to temperature and humidity. It is necessary to sufficiently decompose the remaining methoxy component by a heating step for forming a crosslinked structure with the silicone resin. The electrical resistivity of the carrier thus obtained is such that LogR at 50 V / mm is 14 or more and 17 or less, and LogR of electrical resistivity at 250 V / mm is 8 or more and 16 or less. If the LogR of electrical resistivity at 50 V / mm is smaller than 14, the charge amount during standing is greatly reduced, and the change in charge amount due to temperature and humidity is large. On the other hand, if the LogR of electrical resistivity at 250 V / mm is larger than 16, image density is lowered due to charge-up of the carrier during continuous printing, which is not preferable.
[0034]
In order to make the electric resistance of the carrier appropriate, it is possible to contain a conductive substance in the carrier film. As the conductive substance here, a known conductive material can be used. Examples of the conductive material include, for example, conductive ZnO, metal powder such as Al, SnO made by various methods.₂And SnO doped with various elements₂Borides such as TlB₂ZnB₂, MoB₂, Silicon carbide and conductive polymers (polyacetylene, polyparaphenylene, poly (para-phenylene sulfide), polypyrrole), etc., and most preferably conductive carbon black.
[0035]
  Further, as described above, other hard fine particle components can be contained in the film for the purpose of reinforcing the film. These may be fine particle components having a Mohs hardness of 2 or more having a particle size of 0.01 to 20 μm, preferably 0.01 to 10 μm. Among these, metal oxide and inorganic oxide particles are preferably used because they have a uniform particle size, high affinity with polyamide as a component of the film, and a remarkable effect of reinforcing the film.
  As such fine particles, conventionally known materials can be used alone or in combination, and typically include silica, titanium oxide, alumina and the like. Among these, alumina particles are preferably used in order to charge the toner negatively.
  The content of hard fine particles contained in the film is preferably 5% to 70%.Yes. IncludingThe amount is appropriately selected depending on the particle diameter and specific surface area of the fine particles to be used, but if it is less than 5%, the wear resistance effect of the film is hardly exhibited, and if it exceeds 70%, the particles are likely to be detached.
[0036]
The fine particle content in the film is appropriately selected depending on the film material, but is preferably in the range of 1 to 70 wt%. If it is 1 wt% or less, the effect of improving the film strength is not sufficient, and if it exceeds 70 wt%, fine particles are likely to be detached from the film, which may cause problems in durability.
The average particle diameter of the fine particles used depends on the thickness of the film, but is preferably in the range of 0.01 to 0.7 μm. The particle diameter used for the thickness of the coating is appropriately selected. The film thickness referred to here is a value obtained by dividing the volume of the resin component not containing the fine particle component among the coating layer components of the carrier by the surface area of the carrier core material. The surface area of the carrier core material is obtained by calculating the weight average particle diameter of the carrier core material and calculating the surface area of the corresponding sphere, and the average particle diameter of the fine particles contained with respect to the film thickness is 0.01 to 1. A double particle size range is preferred. If it is less than 0.01 times, the effect of improving the film strength by filling the particles is not recognized. When it is larger than 1 time, particles are likely to be detached from the film.
[0037]
A conventionally well-known thing can be used as a carrier core material which provides the membrane | film | coat which can be used by this invention. For example, ferromagnetic materials such as iron and cobalt, magnetite, hematite, Li ferrite, Mn—Zn ferrite, Cu—Zn ferrite, Ni—Zn ferrite, Ba ferrite, and Mn ferrite can be used.
Ferrite is a sintered body generally represented by the following formula.
Embedded image
(MO) x (NO) y (Fe₂O₃Z
However, x + y + z = 100 mol%, and M and N are Ni, Cu, Zn, Li, Mg, Mn, Sr, Ca, etc., respectively, and the divalent metal oxide and the trivalent iron oxide Consists of a complete mixture.
Among these, Mn—Mg—Sr ferrite, Mn ferrite and the like can be mentioned.
[0038]
As the carrier core material, the above-mentioned magnetic particles are generally used, but so-called resin-dispersed carriers having a form in which a magnetic powder having a smaller particle diameter is dispersed in a known resin such as a phenol resin, an acrylic resin, or a polyester resin are also available Preferably used.
[0039]
The toner used together with the carrier of the present invention is mainly composed of a thermoplastic resin as a binder resin, and contains a colorant, fine particles, a charge control agent, a release agent and the like. In addition, toners produced by various toner production methods such as generally known pulverization methods and polymerization methods can be used.
[0040]
As binder resin, styrene such as polystyrene and polyvinyltoluene and homopolymers thereof, styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-acrylic acid Methyl copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer Polymer, styrene-o-chloromethyl acrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isobutylene Copolymer, styrene-maleic acid Polymer, styrene copolymer such as styrene-maleic acid ester copolymer, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, epoxy resin, polyvinyl butyral, poly Acrylic resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or aromatic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax and the like can be used alone or in combination.
[0041]
The polyester resin is obtained by a polycondensation reaction between an alcohol and an acid. Examples of the alcohol include polyethylene glycol, diethyl glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4- Diols such as propylene glycol, neopentyl glycol, 1,4-butenediol, 1,4-bis (hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropylenated bisphenol A Etherified bisphenols such as these, divalent alcohol monomers in which these are substituted with a saturated or unsaturated hydrocarbon group having 3 to 22 carbon atoms, other divalent alcohol monomers, sorbitol, 1, 2, 3, -Hexanetetrol, 1,4-sarbitane, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol And trihydric or higher alcohol monomers such as 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane and 1,3,5-trihydroxymethylbenzene. Examples of the carboxylic acid used to obtain the polyester resin include monocarboxylic acids such as palmitic acid, stearic acid, and oleic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, terephthalic acid, cyclohexanedicarboxylic acid, and succinic acid. Acids, adipic acid, sebacic acid, malonic acid, divalent organic acid monomers in which these are substituted with saturated or unsaturated hydrocarbon groups having 3 to 22 carbon atoms, anhydrides of these acids, lower alkyl esters and Dimer from linolenic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1, 2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxylic acid-2-methyl A trivalent or higher polyvalent carboxylic acid monomer such as 2-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid embol trimer, and anhydrides of these acids; Can be mentioned.
[0042]
Further, examples of the epoxy resin include a polycondensate of bisphenol A and epichlorohydrin. For example, Epomic R362, R364, R365, R366, R367, R369 (above, manufactured by Mitsui Petrochemical Co., Ltd.), Epototo YD-011, YD There are commercially available products such as -014, YD-904, YD-017 (above, manufactured by Tohto Kasei Co., Ltd.), Epocoat 1002, 1004, 1007 (above, manufactured by Shell Chemical Co., Ltd.).
[0043]
Colorants include carbon black, lamp black, iron black, ultramarine, nigrosine dye, aniline blue, phthalocyanine blue, Hansa Yellow G, rhodamine 6G lake, calco oil blue, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallyl. Conventional dyes and pigments such as methane dyes, monoazo dyes, disazo dyes, and dyes can be used alone or in combination.
[0044]
Further, the toner does not have any inconvenience even if it contains a drug to be contained for the purpose of controlling the triboelectric chargeability as in the case of the toner that is usually used. As such so-called polarity control agents, for example, metal complexes of monoazo dyes, nitrohumic acid and its salts, metal complexes of salicylic acid, naphthoic acid, dicarboxylic acid such as Co, Cr, Fe, Zn, etc. may be used alone or in combination. However, it is not limited to these. The polarity control agent used in the color toner needs to be colorless, and a polymer type polarity control substance having polarity is preferably used.
[0045]
A fluidity modifier can be added to the toner used in the present invention. Examples of fluidity modifiers include organic resin fine particles, metal soaps, polytetrafluoroethylene fluororesins, lubricants such as zinc stearate, or abrasives such as acid value cerium and silicon carbide, generally fluidity modifiers Known metal oxides used for the above-mentioned purposes, typically metal oxide fine particles such as silicon oxide, titanium oxide, and aluminum oxide, and particles whose surfaces are hydrophobized. Hydrophobizing the surface of any of these fine powders has an excellent effect in terms of fluidity. In order to hydrophobize the surface, for example, a silicon compound generally known as a silane coupling agent or silylating agent can be brought into contact with and reacted with the particle surface.
[0046]
As the hydrophobizing agent, for example, chlorosilanes typically include trichlorosilane, methyldichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, ethyldichlorosilane, diethylchlorosilane, triethylchlorosilane, propyldichlorosilane, dipropyldichlorosilane, tripropylchlorosilane, etc. Alkylchlorosilane, phenylchlorosilane, etc. Fluoroalkyl chlorosilanes and perfluoroalkyl chlorosilanes as the fluoro-substituted product. Typical examples of silylamines include hexamethyldisilazane, diethylaminotrimethylsilane, and diethylaminotrimethylsilane. Typical examples of silylamides include N, O-bistrimethylsilylacetamide, N-trimethylsilylacetamide, bistrimethylsilyltrifluoroacetamide, and the like. Examples of alkoxysilanes include methyltrialkoxysilane, dimethyldialkoxysilane, trimethylalkoxysilane, ethyldialkoxysilane, diethylalkoxysilane, triethylalkoxysilane, propyltrialkoxysilane, dipropyldialkoxysilane, and tripropylalkoxysilane. Alkylchlorosilane and phenylalkoxysilane having a phenyl group. In addition, fluoroalkyl alkoxysilanes, perfluoroalkylalkoxysilanes as fluorine-substituted products, dimethylsilicone oil and derivatives thereof as silicone oils, fluorine-substituted products, siloxanes such as disiloxane, hexamethyldisiloxane, etc. The compounds used as generally known hydrophobizing agents can be used.
[0047]
The toner used in the present invention can be made into a magnetic toner by containing a magnetic powder as required.
Magnetic powder used includes magnetic iron oxide particles such as magnetite and maghemite, spinel ferrite particles containing one or more metals other than iron (Mn, Ni, Zn, Mg, Cu, etc.), barium Magnetoplumbite type ferrite particle powder such as ferrite, fine particle powder of iron and its alloy having an oxide layer on the surface, and the like can be used. Moreover, nonmagnetic iron oxide particle powders such as hematite, goethite, and wustite can also be used, and in some cases, they can be used by mixing with the magnetic iron oxide particles.
Preferred are magnetic iron oxide particles such as magnetite and maghematite, or nonmagnetic iron oxide particles such as hematite and goethite. The particle shape may be any of granular, spherical and acicular. The particle diameter of the particles is preferably 0.05 to 5 μm, and a magnetic toner can be obtained by adding several to 70% by weight in the toner.
[0048]
【Example】
Hereinafter, the present invention will be specifically described by way of examples. In addition, this invention is not limited to the Example illustrated here.
<Production Example of Compound 1>
10 parts of the following aminosilane coupling agent was dissolved in 10 parts of methanol. This solution was cooled in an ice bath, and 4 parts of formaldehyde (37%) solution was added dropwise while maintaining the solution temperature at 30 ° C. or lower. After completion of heat generation during mixing, the mixture was stirred at 25 ° C. for 1 hour to obtain a compound 1 solution.
Embedded image
NH₂C₃H₆Si (OCH₃)₃
[0049]
<Production Example of Compound 2>
10 parts of the following aminosilane coupling agent was dissolved in 10 parts of methanol. This solution was cooled in an ice bath, and 4 parts of formaldehyde (37%) solution was added dropwise while maintaining the solution temperature at 30 ° C. or lower. After completion of heat generation during mixing, the mixture was stirred at 25 ° C. for 1 hour to obtain a compound 2 solution.
Embedded image
NH₂C₂H₄NHC₃H₆Si (OCH₃)₃
[0050]
<Production Example 1>
Put 20 parts of methoxymethylated polyamide (EF30T, manufactured by Nagase Chemtech Co., Ltd.), 1 part of citric acid, and 80 parts of methanol in a stirrable glass container equipped with a refluxer. A methoxymethylated polyamide methanol solution was prepared.
To this solution, 100 parts of a methyl silicone resin toluene solution (molecular weight 15000, solid content 20 wt%, curing temperature 120 ° C.), 100 parts of toluene, 100 parts of isopropanol, and 1 part of carbon black (BP2000) were added and dispersed with a homogenizer. Dibutyltin diacetate as a catalyst, 1 part of a toluene solution (40 wt% solution), 0.8 part of γ-aminoethylaminopropyltrimethoxysilane are added to the resulting dispersion, 1 part of adipic acid is added, and the mixture is stirred. Got.
This liquid was applied to a ferrite core material having a weight average diameter of 38 μm and a magnetic moment of 78 emu / g at 1000 gauss using a fluidized bed dryer to provide a resin film. The obtained powder was heat-dried at 210 ° C. for 2 hours to obtain Carrier A having a film thickness of 0.59 μm. LogR of the electrical resistivity of this carrier was 13.8 Ωcm (50 V / mm) and 12.9 Ωcm (250 V / mm).
[0051]
<Production Example 2>
Carrier B was obtained in the same manner as in Production Example 1 except that 2 parts of Compound 1 solution prepared in Production Example of Compound 1 was used in place of γ-aminoethylaminopropyltrimethoxysilane.
The thickness of the film was 0.61 μm, and the LogR of electrical resistivity was 14.1 Ωcm (50 V / mm) and 13.8 Ωcm (250 V / mm).
[0052]
<Production Example 3>
Carrier C was obtained in the same manner except that Compound 2 solution was used instead of Compound 1 in Production Example 2.
The thickness of the film was 0.61 μm, and the LogR of electrical resistivity was 14.1 Ωcm (50 V / mm) and 13.8 Ωcm (250 V / mm).
[0053]
<Production Example 4>
Put 20 parts of methoxymethylated polyamide (EF30T, manufactured by Nagase Chemtech Co., Ltd.), 1 part of citric acid, and 80 parts of methanol in a stirrable glass container equipped with a refluxer. A methoxymethylated polyamide methanol solution was prepared.
To this solution, 8 parts of alumina particles having an average particle diameter of 0.3 μm were added and stirred with a homogenizer.
While stirring this solution, 100 parts of a methyl silicone resin toluene solution (molecular weight 15000, solid content 20 wt%), 100 parts of toluene, 100 parts of isopropanol, and 1 part of carbon black (BP2000) were gradually added and further dispersed with a homogenizer. Dibutyltin diacetate as a catalyst, 1 part of a toluene solution (solid content concentration: 40 wt%), 2 parts of the above compound 2 solution and 1 part of adipic acid were added to the dispersion and stirred to obtain a coating solution.
This liquid was applied to the ferrite core material with a fluid bed dryer to provide a resin film.
The obtained powder was heat-dried at 210 ° C. for 2 hours to obtain a carrier D having a film thickness of 0.59 μm. LogR of the electrical resistivity of this carrier was 13.8 Ωcm (50 V / mm) and 12.9 Ωcm (250 V / mm).
[0054]
<Production Example 5>
Carrier E was obtained in the same manner as in Production Example 4 except that 1 part of adipic acid was changed to 1.25 parts of a toluene solution of paratoluenesulfonic acid (solid concentration 40 wt%) and 0.5 part of benzoic acid. LogR of the electrical resistivity of this carrier was 14.0 Ωcm (50 V / mm) and 13.0 Ωcm (250 V / mm).
[0055]
<Production Example 6>
Carrier F was obtained in the same manner as in Production Example 4 except that the alumina particles used were 8 parts of alumina particles having an average particle diameter of 0.01 μm.
[0056]
<Production Example 7>
Carrier G was obtained in the same manner as in Production Example 1 except that a methyl silicone resin toluene solution (molecular weight 800, solid content 20 wt%, curing temperature 45 ° C.) was used instead of methyl silicone resin in Production Example 1.
[0057]
<Production Example 8>
Carrier H was obtained in the same manner as in Production Example 1 except that a methyl phenyl silicone resin toluene solution (molecular weight 2000, solid content 20 wt%, curing temperature 220 ° C.) was used instead of methyl silicone resin in Production Example 1. This carrier was cured into a block after firing, and pulverized to obtain carrier particles.
[0058]
Example 1
93 parts of carrier A 93 prepared in Production Example 1 and 7 parts of magenta toner for IPSIO Color 8000 are mixed and used as a developer. This is loaded into IPSIO Color 8000, and the image area ratio is 12%. Continuous printing was performed.
A part of the developer was taken out, and then a continuous print test of 100,000 sheets was performed.
[0059]
Before the start of use, the charge amount of the developer was measured at the end of continuous printing after printing 1,000 sheets.
Further, the background stain of the image at the end of printing 100,000 sheets and the charge amount of the developer were similarly evaluated.
The charge amount of the developer was determined based on the blow-off method by collecting a small amount of developer from the sleeve of the developing device.
The thickness of the carrier was determined by crushing the carrier and observing a cross-sectional image with a scanning electron microscope.
The evaluation of the background stain was a four-level evaluation by visual evaluation.
[0060]
Examples 2 to 6 and Comparative Examples 1 and 2
In Example 1, each of the carriers B to H was used in place of the carrier A, and image evaluation was similarly performed using the developer. The results are also shown in the table.
[0061]
[Table 1]

[0062]
【The invention's effect】
As described above, as is clear from the detailed and specific description, the present invention is excellent in that it can provide a highly stable carrier having stable charging properties over a long period of time and excellent film abrasion resistance. There is an effect.

Claims (14)

It has a form having a film on the surface of magnetic fine powder, and the film is obtained from a mixture of (i) N-alkoxyalkylated polyamide and (ii) a resin capable of reacting with the N-alkoxyalkylated polyamide resin. A room temperature liquid silicone resin containing a cross-linked product, wherein the reactive resin (ii) has at least a silanol group and / or a hydrolyzable group, and has a gelling temperature of 60 ° C. or higher and 170 ° C. or lower. A carrier for developing an electrostatic latent image.   The carrier for developing an electrostatic latent image according to claim 1, wherein the silicone resin is a methyl silicone compound having a molecular weight of 1,000 to 100,000.   3. The electrostatic latent image developing carrier according to claim 1, wherein the film contains an aminosilane compound and / or a condensate thereof. 3. The electrostatic latent image developing carrier according to claim 1, wherein the film contains a compound A having the following structure.

R ₁ : C1-3 alkyl group R ₂ : C1-8 linear alkylene chain R ₃ : C1-2 linear alkylene chain R ₄ : C1-4 alkyl group 3. The electrostatic latent image developing carrier according to claim 1, wherein the film contains a compound B having the following structure.

R ₁ : C 1-3 alkyl group R ₂ , R ₃ : C 1-8 linear alkylene chain R ₄ : C 1-2 linear alkylene chain R ₅ : C 1-4 alkyl group 6. The electrostatic latent image developing carrier according to claim 5, wherein the compound B is a compound having the following structure.

  2. The electrostatic latent image developing carrier according to claim 1, wherein the polyamide is an N-methoxymethylated polyamide having a methoxylation rate of 20% to 70%.   The electrostatic latent image developing carrier according to claim 1, wherein the coating contains a solid organic acid having a boiling point of 100 ° C. or more.   9. The electrostatic latent voltage according to claim 1, wherein LogR of electrical resistivity at an applied electric field of 50 V / mm is 14 or more, and LogR of electrical resistivity at 250 V / mm is 16 or less. Image development carrier. 10. The electrostatic latent image developing carrier according to claim 1, wherein the film contains a low-resistance substance having a volume resistivity of 10 ⁻² Ω · cm to 10 ⁸ Ω · cm. .   11. The electrostatic latent image developing carrier according to claim 1, wherein the coating contains oxide fine particles of any one of Si, Ti, and Al.   12. The electrostatic latent image developing carrier according to claim 11, wherein the content of the oxide fine particles in the film is in the range of 5% by weight to 70% by weight of the film resin amount.   The carrier for developing an electrostatic latent image according to claim 11, wherein the oxide fine particles are alumina fine particles. 14. The electrostatic latent image developing carrier according to claim 13, wherein the alumina fine particles have an average particle diameter of 0.01 μm to 0.7 μm.