JP2004109634A - Electrostatic charge image dry type toner composition, developer for developing electrostatic latent image and method for forming image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic charge image dry type toner composition capable of simultaneously satisfying toner fluidity, an electrostatic chargeability, a developability, a transferability, a cleanability, and a fixability over a long period, preventing the occurrence of flaws on a latent image carrier, eliminating a blade cleaning process which may accelerate especially the abrasion of the latent image carrier, and improving complicatedness that remaining transfer toner should be recovered simultaneously with development or toner remaining on the surface of the latent image carrier should be recovered by an electrostatic brush and to provide an electrostatic latent image developer using the toner composition. <P>SOLUTION: The electrostatic charge image dry type toner composition containing binding resin, a coloring agent and a release agent contains two sorts or more of inorganic oxide fine powder having respectively different volume average primary grain diameters and one sort is inorganic oxide fine powder formed by coating the surface of fine powder with a charge controlling agent. <P>COPYRIGHT: (C)2004,JPO

Description

【０１２７】
上記式において、分子▲１▼は、平均粒径から計算により求めた。また、分母▲２▼は、島津粉体比表面積測定装置ＳＳ−１００型を用い、ＢＥＴ比表面積より代用させた。
【０１２８】
−抵抗測定−
図２に示されるように、測定試料５３の厚みをＨとして、下部電極５４と上部電極５２とで挟持し、上方より加圧しながらダイヤルゲージで厚みを測定し測定試料５３の電気抵抗を高電圧抵抗計５５で計測した。具体的には、特定酸化チタンの試料に成形機にて４．９×１０^７Ｐａの圧力を加えて測定ディスクを作製した。次いで、ディスクの表面をハケで清掃し、セル内の上部電極５２と下部電極５４との間に挟み込み、ダイヤルゲージで厚みを測定した。次に電圧を印加し、電流値を読み取ることにより、体積固有抵抗を求めた。
また、キャリヤの試料を１００φの下部電極５４に充填し、上部電極５２をセットし、その上から３．４３ｋｇの荷重を加え、ダイヤルゲージで厚みを測定した。次に電圧を印加し、電流値を読み取ることにより、体積固有抵抗を求めた。
【０１２９】
−トナー形状ＳＦ１（ＭＬ^２／Ａ）−
本発明において、トナーの平均形状指数ＳＦ１（ＭＬ^２／Ａ）とは、下記式（５）で計算された値を意味し、真球の場合ＭＬ^２／Ａ＝１００となる。
ＭＬ^２／Ａ＝（最大長）^２×π×１００／（面積×４）　・・・　式（５）
平均形状指数を求めるための具体的な手法として、トナー画像を光学顕微鏡から画像解析装置（ＬＵＺＥＸ　ＩＩＩ、（株）ニレコ製）に取り込み、円相当径を測定して、最大長及び面積から、個々の粒子について上記式のＭＬ^２／Ａの値を求める。
【０１３０】
−帯電量測定−
高温高湿及び低温低湿における帯電量は、高温高湿（３０℃、９０％ＲＨ）、低温低湿（５℃、１０％ＲＨ）の各雰囲気下にトナー組生物、キャリヤの双方をそれぞれ２４時間放置し、蓋付きガラスビンに、トナー濃度が５質量％になるように、トナー組成物、キャリヤを採取し、それぞれの雰囲気下でターブラ攪拌を行い、攪拌された現像剤を２５℃、５５％ＲＨの条件下で東芝社製ＴＢ２００にて測定した。
なお、実機評価試験における帯電量は、現像器中のマグスリーブ上の現像剤を採取し、上記と同様２５℃、５５％ＲＨの条件下で東芝社製ＴＢ２００にて測定した。
【０１３１】
−画像濃度（Ｓｏｌｉｄ　Ａｒｅａ　Ｄｅｎｓｉｔｙ）−
画像濃度は、Ｘ−Ｒｉｔｅ４０４Ａ（Ｘ−Ｒｉｔｅ）を用いて測定した。
【０１３２】
＜外添剤の調製＞
−帯電制御剤被覆無機酸化物微粉末（Ａ）の調製−
酸化ケイ素微粉末ＲＸ２００（疎水性、粒子形状：不定形、体積平均１次粒径１２ｎｍ、日本アエロジル社製）３０００質量部をエッジランナー「ＭＰＵＶ−２型」（製品名、株式会社松本鋳造鉄工所製）に投入し、メチルトリエトキシシラン（商品名：ＴＳＬ８１２３：東芝シリコーン株式会社製）５０質量部を２００質量部のエタノールで混合希釈して得られるメチルトリエトキシシラン溶液を、エッジランナーを稼動させながら上記酸化ケイ素微粉末に添加し、混合攪拌を行った。
【０１３３】
次に、１−ナフトール−４−硫酸のベンジルトリエチルアンモニウム塩２００質量部を、エッジランナーを稼動させながら１０分間かけて添加し、混合攪拌を行い、メチルトリエトキシシラン被覆の表面に１−ナフトール−４−硫酸のベンジルトリエチルアンモニウム塩を付着させた後、乾燥を用いて１０５℃で６０分間加熱処理を行い、帯電制御剤被覆無機酸化物微粉末（Ａ）を得た。
上記微粉末の体積平均１次粒径は１５ｎｍであり、被覆状態を観察した結果、被覆厚みは１．０〜２．０ｎｍの範囲であり、微粉末表面の１００％が被覆されていた。
【０１３４】
−帯電制御剤被覆無機酸化物微粉末（Ｂ）の調製−
酸化ケイ素微粉末Ｒ８１２（疎水性、粒子形状：不定形、体積平均１次粒径８ｎｍ、日本アエロジル社製）３０００質量部をエッジランナー「ＭＰＵＶ−２型」（製品名、株式会社松本鋳造鉄工所製）に投入し、メチルトリエトキシシラン（商品名：ＴＳＬ８１２３：東芝シリコーン株式会社製）５０質量部を２００質量部のエタノールで混合希釈して得られるメチルトリエトキシシラン溶液を、エッジランナーを稼動させながら上記酸化ケイ素微粉末に添加し、混合攪拌を行った。
【０１３５】
次に、トリフェニルメタン系染料１００質量部を、エッジランナーを稼動させながら１０分間かけて添加し、混合攪拌を行い、メチルトリエトキシシラン被覆の表面にトリフェニルメタン系染料を付着させた後、乾燥を用いて１０５℃で６０分間加熱処理を行い、帯電制御剤被覆無機酸化物微粉末（Ｂ）を得た。
上記微粉末の体積平均１次粒径は１０ｎｍであり、被覆状態を観察した結果、被覆厚みは０．５〜１．５ｎｍの範囲であり、微粉末表面の１００％が被覆されていた。
【０１３６】
−帯電制御剤被覆無機酸化物微粉末（Ｃ）の調製−
酸化チタン微粉末ＭＴ−１５０Ａ（粒子形状：コメ粒状、体積平均１次粒径２０ｎｍ）１５００質量部を、エッジランナー「ＭＰＵＶ−２型」（製品名、株式会社松本鋳造鉄工所製）に投入し、メチルトリエトキシシラン（商品名：ＴＳＬ８１２３：東芝シリコーン株式会社製）５０質量部を２００質量部のエタノールで混合希釈して得られるメチルトリエトキシシラン溶液を、エッジランナーを稼動させながら上記酸化チタン微粉末に添加し、混合攪拌を行った。
【０１３７】
次に、サリチル酸亜鉛誘導体１５０質量部を、エッジランナーを稼動させながら１０分間かけて添加し、混合攪拌を行い、メチルトリエトキシシラン被覆の表面にサリチル酸亜鉛誘導体を付着させた後、乾燥を用いて１０５℃で６０分間加熱処理を行い、帯電制御剤被覆無機酸化物微粉末（Ｃ）を得た。
上記微粉末の体積平均１次粒径１３ｎｍであり、被覆状態を観察した結果、被覆厚みは０．５〜２．０ｎｍの範囲であり、微粉末表面の１００％が被覆されていた。
【０１３８】
−単分散球形シリカ（Ａ）の調製−
ゾルゲル法で得られたシリカゾルにＨＭＤＳ処理を行い、乾燥、粉砕により比重が１．５０、球形化度Ψが０．７０、体積平均１次粒径Ｄ５０が１００ｎｍ（標準偏差：４０ｎｍ）の球形単分散シリカを得た。
【０１３９】
−単分散球形シリカ（Ｂ）の調製−
ゾルゲル法で得られたシリカゾルにＨＭＤＳ処理を行い、乾燥、粉砕により比重が１．３０、球形化度Ψが０．７０、体積平均一次粒径Ｄ５０が１２０ｎｍ（標準偏差：４０ｎｍ）の球形単分散シリカを得た。
【０１４０】
＜着色粒子Ａの製造＞
・スチレン−ｎブチルアクリレート樹脂（Ｔｇ：５８℃、Ｍｎ：４０００、Ｍｗ：２５０００）：１００部
・カーボンブラック（モーガルＬ、キャボット製）：３部
【０１４１】
上記混合物をエクストルーダーで混練し、ジェットミルで粉砕した後、風力式分級機で分散してＤ５０が５．０μｍ、ＭＬ^２／Ａが１４８．８の黒トナーＡを得た。
【０１４２】
＜着色粒子Ｂの製造＞
−樹脂分散液（１）の調製−
・スチレン：３７０質量部
・ｎ−ブチルアクリレート：３０質量部
・アクリル酸：８質量部
・ドデカンチオール：２４質量部
・四臭化炭素：４質量部
【０１４３】
以上の成分を混合して溶解したものを、非イオン性界面活性剤（ノニポール４００：三洋化成（株）製）６質量部及びアニオン性界面活性剤（ネオゲンＳＣ：第一工業製薬（株）製）１０質量部をイオン交換水５５０質量部に溶解したものにフラスコ中で乳化分散させ、１０分間ゆっくり混合しながら、これに過硫酸アンモニウム４質量部を溶解したイオン交換水５０質量部を投入した。窒素置換を行った後、前記フラスコ内を攪拌しながら、内容物が７０℃になるまでオイルバスで加熱し、５時間そのまま乳化重合を継続した。
その結果、平均粒径が１５５ｎｍであり、Ｔｇが５９℃、質量平均分子量Ｍｗが１２０００の樹脂粒子が分散された樹脂分散液（１）が得られた。
【０１４４】
−樹脂分散液（２）の調製−
・スチレン：２８０質量部
・ｎ−ブチルアクリレート：１２０質量部
・アクリル酸：８質量部
【０１４５】
以上の成分を混合して溶解したものを、非イオン性界面活性剤（ノニポール４００：三洋化成（株）製）６質量部及びアニオン性界面活性剤（ネオゲンＳＣ：第一工業製薬（株）製）１２質量部をイオン交換水５５０質量部に溶解したものにフラスコ中で乳化分散させ、１０分間ゆっくり混合しながら、これに過硫酸アンモニウム３質量部を溶解したイオン交換水５０質量部を投入した。窒素置換を行った後、前記フラスコ内を攪拌しながら、内容物が７０℃になるまでオイルバスで加熱し、５時間そのまま乳化重合を継続した。
その結果、平均粒径が１０５ｎｍであり、Ｔｇが５３℃、質量平均分子量Ｍｗが５５００００の樹脂粒子が分散された樹脂分散液（２）が得られた。
【０１４６】
−着色分散液（１）の調製−
・カーボンブラック（モーガルＬ：キャボット製）：５０質量部
・ノニオン性界面活性剤（ノニポール４００：三洋化成（株）製）：５質量部
・イオン交換水：２００質量部
【０１４７】
以上の成分を混合して、溶解、ホモジナイザー（ウルトラタラックスＴ５０：ＩＫＡ社製）を用いて１０分間分散し、平均粒子径が２５０ｎｍである着色剤（カーボンブラック）粒子が分散された着色分散剤（１）を得た。
【０１４８】
−着色分散液（２）の調整−
・Ｃｙａｎ顔料（Ｐｉｇｍｅｎｔ・Ｂｌｕｅ１５：３）：７０質量部
・ノニオン性界面活性剤（ノニポール４００：三洋化成（株）製）：５質量部
・イオン交換水：２００質量部
【０１４９】
以上の成分を混合して、溶解、ホモジナイザー（ウルトラタラックスＴ５０：ＩＫＡ社製）を用いて１０分間分散し、平均粒子径が２５０ｎｍである着色剤（Ｃｙａｎ顔料）粒子が分散された着色分散剤（２）を得た。
【０１５０】
−着色分散液（３）の調製−
・Ｍａｇｅｎｔａ顔料（Ｐｉｇｍｅｎｔ・Ｒｅｄ１２２）：７０質量部
・ノニオン性界面活性剤（ノニポール４００：三洋化成（株）製）：５質量部
・イオン交換水：２００質量部
【０１５１】
以上の成分を混合して、溶解、ホモジナイザー（ウルトラタラックスＴ５０：ＩＫＡ社製）を用いて１０分間分散し、平均粒子径が２５０ｎｍである着色剤（Ｍａｇｅｎｔａ顔料）粒子が分散された着色分散剤（２）を得た。
【０１５２】
−着色分散液（４）の調製−
・Ｙｅｌｌｏｗ顔料（Ｐｉｇｍｅｎｔ・Ｙｅｌｌｏｗ１８０）：１００質量部
・ノニオン性界面活性剤（ノニポール４００：三洋化成（株）製）：５質量部
・イオン交換水：２００質量部
【０１５３】
以上の成分を混合して、溶解、ホモジナイザー（ウルトラタラックスＴ５０：ＩＫＡ社製）を用いて１０分間分散し、平均粒子径が２５０ｎｍである着色剤（Ｙｅｌｌｏｗ顔料）粒子が分散された着色分散剤（４）を得た。
【０１５４】
−離型剤分散液の調製−
・パラフィンワックス（ＨＮＰ０１９０：日本精蝋（株）製、融点８５℃）：５０質量部
・カチオン性界面活性剤：（サニゾールＢ５０：花王（株）製）：５質量部
【０１５５】
以上の成分を、丸型ステンレス鋼製フラスコ中でホモジナイザー（ウルトラタラックスＴ５０：ＩＫＡ社製）を用いて１０分間分散した後、圧力吐出型ホモジナイザーで分散処理し、平均粒径が５５０ｎｍである離型剤粒子が分散された離型剤分散液（１）を得た。
【０１５６】
−凝集粒子の調製−
・樹脂分散液（１）：１２０質量部
・樹脂分散液（２）：８０質量部
・着色剤分散液：２００質量部
・離型分散液（１）：４０質量部
・カチオン性界面活性剤（サニゾールＢ５０：花王（株）製）：１．５質量部
【０１５７】
以上の成分を、丸型ステンレス鋼鉄フラスコ中でホモジナイザー（ウルトラタラックスＴ５０：ＩＫＡ社製）を用いて混合し、分散した後、加熱用オイルバス中でフラスコ内を攪拌しながら５０℃まで加熱した。４５℃で２０分間保持した後、光学顕微鏡で確認したところ、体積平均粒径Ｄ５０が約４．３μｍである凝集粒子が形成されていることが確認された。さらに上記分散液に、樹脂含有微粒子分散液として樹脂分散液（１）を緩やかに６０質量部追加した。そして加熱用オイルバスの温度を５０℃まで上げて３０分間保持した。光学顕微鏡にて観察したところ、体積平均粒径Ｄ５０が約４．５μｍである付着粒子が形成されていることが確認された。
【０１５８】
−着色粒子Ｂの作製−
上記粒子分散液に、アニオン性界面活性剤（ネオゲンＳＣ：第一工業製薬（株）製）３質量部を追加した後、前記ステンレス鋼鉄フラスコ中を密閉し、磁力シールを用いて攪拌しながら１０５℃まで加熱し、４時間保持した。
そして、冷却後、反応生成物をろ過し、イオン交換水で充分に洗浄した後、乾燥させることにより、静電荷像現像用着色粒子を得た。
【０１５９】
−着色粒子ＫｕｒｏＢの作製−
着色剤分散液（１）を用いて、上記手法にてＭＬ^２／Ａが１２８．５、粒径Ｄ５０が５．８μｍのＫｕｒｏトナーを得た。
【０１６０】
−着色粒子ＣｙａｎＢの作製−
着色剤分散液（２）を用いて上記手法にてＭＬ^２／Ａが１３０、粒径Ｄ５０が５．６μｍのＣｙａｎトナーを得た。
【０１６１】
−着色粒子ＭａｇｅｎｔａＢの作製−
着色剤分散液（３）を用いて上記手法にてＭＬ^２／Ａが１３２．５、粒径Ｄ５０が５．５μｍのＭａｇｅｎｔａトナーを得た。
【０１６２】
−着色粒子ＹｅｌｌｏｗＢの作製−
着色剤分散液（４）を用いて上記手法にてＭＬ^２／Ａが１２７、粒径Ｄ５０が５．９μｍのＹｅｌｌｏｗトナーを得た。
【０１６３】
＜キャリヤの製造＞
・フェライト粒子（体積平均粒径：５０μｍ）：１００部
・トルエン：１４部
・スチレン−メタクリレート共重合体（成分比：９０／１０）：２部
・カーボンブラック（Ｒ３３０：キャボット社製）：０．２部
【０１６４】
まず、フェライト粒子を除く上記成分を１０分間スターラーで撹拌させて、分散した被覆液を調製し、次に、この被覆液とフェライト粒子とを真空脱気型ニーダーに入れて、６０℃において３０分撹拌した後、さらに加温しながら減圧して脱気し、乾燥させることによりキャリヤを得た。このキャリヤは、１０００Ｖ／ｃｍの印加電界時の体積固有抵抗値が１０^１１Ωｃｍであった。
【０１６５】
（実施例１）
前記着色粒子ＢのＫｕｒｏ、Ｃｙａｎ、Ｍａｇｅｎｔａ、Ｙｅｌｌｏｗトナーのそれぞれ１００部に、帯電制御剤被覆無機酸化物微粉末（Ａ）１部、体積平均１次粒径５０ｎｍの疎水性酸化チタン（ＴＡＦ−５００Ｓ、富士チタン社製）１．３部を加え、ヘンシェルミキサーを用い周速３２ｍ／ｓで１０分間ブレンドを行った後、４５μｍ網目のシーブを用いて粗大粒子を除去し、トナーを得た。
前記キャリヤ１００部と上記トナー５部とをＶ−ブレンダーを用い４０ｒｐｍで２０分間攪拌し、１７７μｍの網目を有するシーブで篩うことにより現像剤を得た。
【０１６６】
上記現像剤を、タンデムシステムを有するＦｕｊｉ　Ｘｅｒｏｘ社製複写機Ｄｏｃｕ　Ｃｅｎｔｒｅ　Ｃｏｌｏｒ　５００改造機に適用し、高温高湿（２８℃、８０ＲＨ％）と低温低湿（１０℃、１５ＲＨ％）にそれぞれ一昼夜放置した後、それぞれの環境下で３０分間空回して現像剤の帯電性評価を行った。また、これを２万枚コピー後の現像剤についても行った。
【０１６７】
帯電性評価法はブローオフ法によって測定した。ブローオフ法は、上部と下部に網目開き１８μｍの網を張った容量３０ｍｌの金属ゲージ内に試料を０．５ｇ入れ、３．０４×１０^５Ｐａの窒素ガス中で３０秒ブローオフし、生じた電荷を電位計（ケイスレー社製、６５１７Ａ）で測定し、下記式（６）により算出した。
帯電量＝測定電荷値／〔（ブローオフ前ゲージ重量）−（ブローオフ後ゲージ重量）〕　・・・　式（６）
【０１６８】
なお、上記帯電性評価は、以下の基準にしたがって行った。
−帯電評価基準−
○：良好
△：やや環境依存性がみられた
×：悪い
以上の結果を表１に示す。
【０１６９】
また、前記現像剤を高温高湿（２８℃、８０ＲＨ％）と低温低湿（１０℃、１５ＲＨ％）にそれぞれ一昼夜放置した後、タンデムシステムのＦｕｊｉ　Ｘｅｒｏｘ社製ＤｏｃｕＣｅｎｔｒｅ　Ｃｏｌｏｒ　４００ＣＰ改造機に適用し、それぞれの環境下で５０，０００枚画出し、１枚目の画出しサンプルと、５０，０００枚画出しサンプルの画質評価と帯電性評価を行った。
【０１７０】
なお、上記画質評価は以下の規準により行った。
−画質評価基準−
◎：非常に良好
○：良好
△：やや悪い
×：悪い
以上の結果を表２に示す。
【０１７１】
（実施例２）
上記着色粒子ＢＫｕｒｏ１００部に、帯電制御剤被覆無機酸化物微粉末（Ｂ）１部、体積平均１次粒径５０ｎｍの疎水性酸化チタン（ＴＡＦ−５００Ｓ、富士チタン社製）１．４部を加え、ヘンシェルミキサーを用い周速３２ｍ／ｓで１０分間ブレンドを行った後、４５μｍ網目のシーブを用いて粗大粒子を除去し、トナーを得た。
前記キャリヤ１００部と上記トナー５部とをＶ−ブレンダーを用い４０ｒｐｍで２０分間攪拌し、１７７μｍの網目を有するシーブで篩うことにより現像剤を得た。
【０１７２】
上記現像剤について、実施例１と同様の評価を行った。結果を表１、２に示す。
【０１７３】
（実施例３）
上記着色粒子ＢＫｕｒｏ１００部に、帯電制御剤被覆無機酸化物微粉末（Ｃ）０．７部、体積平均１次粒径４０ｎｍの疎水性シリカ（ＲＸ５０、日本アエロジル社製）１．５部を加え、ヘンシェルミキサーを用い周速３２ｍ／ｓで１０分間ブレンドを行った後、４５μｍ網目のシーブを用いて粗大粒子を除去し、トナーを得た。
前記キャリヤ１００部と上記トナー５部とをＶ−ブレンダーを用い４０ｒｐｍで２０分間攪拌し、１７７μｍの網目を有するシーブで篩うことにより現像剤を得た。
【０１７４】
上記現像剤について、実施例１と同様の評価を行った。結果を表１、２に示す。
【０１７５】
（実施例４）
上記着色粒子ＡＫｕｒｏ１００部に、帯電制御剤被覆無機酸化物微粉末（Ａ）１．３部、体積平均一次粒径５０ｎｍの疎水性酸化チタン（ＴＡＦ−５００Ｓ、富士チタン社製）１．２部を加え、ヘンシェルミキサーを用い周速３２ｍ／ｓで１０分間ブレンドを行った後、４５μｍ網目のシーブを用いて粗大粒子を除去し、トナーを得た。
前記キャリヤ１００部と上記トナー５部とをＶ−ブレンダーを用い４０ｒｐｍで２０分間攪拌し、１７７μｍの網目を有するシーブで篩うことにより現像剤を得た。
【０１７６】
上記現像剤について、実施例１と同様の評価を行った。結果を表１、２に示す。
【０１７７】
（実施例５）
上記着色粒子ＢＫｕｒｏ１００部に、単分散球形シリカ（Ａ）２部を加え、ヘンシェルミキサーを用い周速３２ｍ／ｓで１０分間ブレンドを行った後、帯電制御剤被覆無機酸化物微粉末（Ａ）１部、体積平均１次粒径５０ｎｍの疎水性酸化チタン（ＴＡＦ−５００Ｓ、富士チタン社製）１．４部を加え、周速２０ｍ／ｓで５分間ブレンドを行い、４５μｍ網目のシーブを用いて粗大粒子を除去し、トナーを得た。
前記キャリヤ１００部と上記トナー５部とをＶ−ブレンダーを用い４０ｒｐｍで２０分間攪拌し、１７７μｍの網目を有するシーブで篩うことにより現像剤を得た。
【０１７８】
上記現像剤について、実施例１と同様の評価を行った。結果を表１、２に示す。
【０１７９】
（実施例６）
上記着色粒子ＢＫｕｒｏ１００部に、単分散球形シリカ（Ｂ）１．５部を加え、ヘンシェルミキサーを用い周速３２ｍ／ｓで１０分間ブレンドを行った後、帯電制御剤被覆無機酸化物微粉末（Ａ）１部、体積平均一次粒径５０ｎｍの疎水性酸化チタン（ＴＡＦ−５００Ｓ、富士チタン社製）１．４部加え、周速２０ｍ／ｓで５分間ブレンドを行い、４５μｍ網目のシーブを用いて粗大粒子を除去し、トナーを得た。
前記キャリヤ１００部と上記トナー５部とをＶ−ブレンダーを用い４０ｒｐｍで２０分間攪拌し、１７７μｍの網目を有するシーブで篩うことにより現像剤を得た。
【０１８０】
上記現像剤について、実施例１と同様の評価を行った。結果を表１、２に示す。
【０１８１】
（実施例７）
上記着色粒子ＢＫｕｒｏ１００部に単分散球形シリカ（Ａ）２部、帯電制御剤被覆無機酸化物微粉末（Ａ）１部、体積平均１次粒径５０ｎｍの疎水性酸化チタン（ＴＡＦ−５００Ｓ、富士チタン社製）１．４部を加え、ヘンシェルミキサーを用い周速３２ｍ／ｓで１０分間ブレンドを行った後、４５μｍ網目のシーブを用いて粗大粒子を除去し、トナーを得た。
前記キャリヤ１００部と上記トナー５部とをＶ−ブレンダーを用い４０ｒｐｍで２０分間攪拌し１７７μｍの網目を有するシーブで篩うことにより現像剤を得た。
【０１８２】
上記現像剤について、実施例１と同様の評価を行った。結果を表１、２に示す。
【０１８３】
（比較例１）
上記着色粒子ＢＫｕｒｏ１００部に、酸化ケイ素微粉末ＲＸ２００（疎水性、粒子形状：不定形、体積平均１次粒径１２ｎｍ、日本アエロジル社製）を１０％デシルトリメトキシシラン処理した微粉末０．７部、体積平均１次粒径５０ｎｍの疎水性酸化チタン（ＴＡＦ−５００Ｓ、富士チタン社製）１．２部を加え、ヘンシェルミキサーを用い周速３２ｍ／ｓで１０分間ブレンドを行った後、４５μｍ網目のシーブを用いて粗大粒子を除去し、トナーを得た。
前記キャリヤ１００部と上記トナー５部とをＶ−ブレンダーを用い４０ｒｐｍで２０分間攪拌し、１７７μｍの網目を有するシーブで篩うことにより現像剤を得た。
【０１８４】
上記現像剤について、実施例１と同様の評価を行った。結果を表１、２に示す。
【０１８５】
（比較例２）
実施例２において、平均粒子径５０ｎｍの疎水性酸化チタン（ＴＡＦ−５００Ｓ、富士チタン社製）を用いなかった以外は実施例２と同様にして現像剤を得た。
【０１８６】
上記現像剤について、実施例１と同様の評価を行った。結果を表１、２に示す。
【０１８７】
（比較例３）
実施例２において、帯電制御剤被覆無機酸化物微粉末（Ｂ）１部を、平均粒子径８ｎｍの疎水性シリカ（Ｒ８１２、日本アエロジル社製）１．２部に代えた以外は実施例２と同様にして現像剤を得た。
【０１８８】
上記現像剤について、実施例１と同様の評価を行った。結果を表１、２に示す。
【０１８９】
【表１】

【０１９０】
【表２】

【０１９１】
表１の結果から明らかなように、実施例１〜７及び比較例１の現像剤は、高温高湿及び低温低湿における帯電性が非常に良好であり、環境安定性も優れていた。一方、比較例２の現像剤は、高温高湿において帯電量の減少が、低温低湿下では帯電量の増加が認められ、環境依存性に若干問題があった。比較例３の現像剤は、高温高湿における帯電量が低く環境依存性に若干問題があった。
【０１９２】
また、表２の結果から明らかなように、本発明の、体積平均一次粒径の異なる２種以上の無機酸化物微粉末が添加され、かつそのうちの１種が帯電制御剤で表面を被覆した無機酸化物微粉末を用いたトナーの現像剤は、実施例１〜７の結果のように、長時間複写を続けた時も低温低湿下と高温高湿下で帯電特性の差は小さく、また帯電維持性が良好であり、長期繰り返し使用においても画質も良好であった。
【０１９３】
一方、体積平均１次粒径の異なる２種以上の無機酸化物微粉末が添加されたものの、帯電制御剤で表面を被覆した無機酸化物微粉末を用いないトナーの現像剤は、比較例１の結果のように長時間複写を続けた時の低温低湿下と高温高湿下の帯電特性の差が大きく、また長期繰り返し使用においてカブリが発生し帯電維持性が不良であった。また、小さな粒径の無機酸化物微粉末だけを添加したトナーの現像剤は、比較例３の結果のように初期から転写性が不十分であった。
【０１９４】
（実施例８）
実施例５において、システムのクリーニングブレードを除去し、カーボンブラックを分散せしめた導電フィラーを有する繊維樹脂からなる静電ブラシを付加し、帯電装置をロール帯電装置に変更した以外は実施例５と同様にして現像及び転写性の評価を行った。
その結果、初期は勿論、２万枚コピー後も初期同様鮮明な画像を呈し、画像の問題は発生しなかった。
【０１９５】
（実施例９）
実施例５において、システムのブレード及びブラシクリーニングを一切一切用いず、スコロトロン帯電器を用いて現像装置でトナーの回収を行なった以外は実施例５と同様にして評価を行った。
その結果、初期は勿論、２万枚コピー後も初期同様鮮明な画像を呈し、画像の問題は発生しなかった。
【０１９６】
（実施例１０）
実施例５において、転写ベルトの表面材質をＰＦＡに変更し、裏面から加熱する装置を付与し、転写同時定着を行えるようにし、また、その際に、実施例１の４色のトナーを実施例５の外添剤組成に変更したものを用いて４色を作製し、色を組み合わせて検討したところ、写真画質に近い鮮明な高画質を得ることができた。
【０１９７】
【発明の効果】
以上説明したように、本発明によれば、耐環境依存性が良好で、トナー流動性、帯電性、現像性、転写性、クリーニング性、定着性を同時に、且つ長期に渡り満足でき、特に潜像担持体摩耗を促進させるブレードクリーニング工程を有さず、現像と同時に転写残トナーを回収する、あるいは静電ブラシを用い潜像担持体上の残留トナーを回収する不具合を改善した静電荷像乾式トナー、及びそれを用いた静電潜像現像用現像剤を提供することができる。さらに、高画質要求に対応する現像、転写、定着が可能な画像形成方法を提供することができる。
【図面の簡単な説明】
【図１】本発明において用いられる画像形成装置の一例を示す概略断面図である。
【図２】キャリアの体積固有抵抗値を測定する方法を説明するための概略説明図である。
【符号の説明】
１Ｙ、１Ｍ、１Ｃ、１Ｋ　感光体ドラム（潜像担持体）
３Ｙ、３Ｍ、３Ｃ、３Ｋ　潜像形成手段
４Ｙ、４Ｍ、４Ｃ、４Ｋ　現像器
５Ｙ、５Ｍ、５Ｃ、５Ｋ　１次転写ロール
６Ｙ、６Ｍ、６Ｃ、６Ｋ　クリーニング手段
１１　駆動ロール
１２　支持ロール
１３　バックアップロール
１４　二次転写ロール
１５　中間転写ベルト
１６　被転写体
１７　清掃部材
１８　定着器
２０Ｙ，２０Ｍ，２０Ｃ，２０Ｋ　帯電器（帯電手段）
４０Ｙ，４０Ｍ，４０Ｃ，４０Ｋ　現像ユニット
５２　上部電極
５３　測定試料
５４　下部電極
５５　高電圧抵抗計[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a toner, a developer, and an image forming method used for developing an electrostatic latent image in electrophotography and electrostatic recording.
[0002]
[Prior art]
In electrophotography, an electrostatic latent image formed on the surface of a latent image carrier (photoreceptor) is developed into a toner image with a toner composition containing a colorant (hereinafter sometimes simply referred to as “toner”). The obtained toner image is transferred to the surface of the recording medium and is fixed by a heat roll or the like to obtain an image. On the other hand, the latent image carrier is cleaned again to form an electrostatic latent image. Things.
[0003]
The dry developer used in such electrophotography and the like includes a one-component developer in which a toner in which a colorant or the like is mixed with a binder resin is used alone and a two-component developer in which a carrier is mixed with the toner. It is roughly divided. Since the latter half of the 1980s, the market for electrophotography has been strongly demanded for miniaturization and high functionality with the keyword of digitization. In particular, regarding the image quality of full-color images, high-quality printing close to high-grade printing and silver halide photography is desired.
[0004]
As means for achieving high image quality, digitization processing is indispensable. As an effect of digitization regarding such image quality, it is mentioned that complicated image processing can be performed at high speed. This makes it possible to control the character image and the photographic image separately, and the reproducibility of the quality of both images is greatly improved as compared with the analog technology. In particular, with respect to photographic images, gradation correction and color correction have become possible, which is more advantageous than analog in terms of gradation characteristics, definition, sharpness, color reproduction, and graininess. However, on the other hand, as the image output, it is necessary to faithfully form a latent image created by an optical system, and as a toner, the activity of aiming for faithful reproduction has been accelerated as the particle size has been further reduced, but simply It is difficult to stably obtain high image quality only by reducing the particle size of the toner, and it is more important to improve basic characteristics in development, transfer, and fixing characteristics.
[0005]
Particularly, in the case of a color image, an image is formed by superimposing three or four color toners. Therefore, if any one of these toners exhibits characteristics different from those at the initial stage or different performances from other colors in the development, transfer, and fixing stages, the color reproduction is reduced, or the granularity is deteriorated, and the image quality is deteriorated such as color unevenness. Will cause it. In order to maintain a stable high-quality image over time as well as in the initial stage, it is important how to stably control the characteristics of each toner.
[0006]
Dry developers can be broadly classified into one-component developers that use a toner itself in which a colorant is dispersed in a binder resin, and two-component developers in which a carrier is mixed with the toner. In any case, when copying, the electrostatic latent image formed on the photoreceptor is developed with these developers, the toner image on the photoreceptor surface is transferred, and the toner remaining on the photoreceptor surface is cleaned. Is what you do. Therefore, it is necessary that the dry developer satisfies various conditions in the copying process, particularly in the developing process or the cleaning process. In other words, the toner is subjected to development in the form of particles, not as agglomerates, during the development. For this purpose, the toner has sufficient fluidity and the fluidity or electrical properties are not sufficient. It is necessary that the temperature does not change over time or due to the environment (temperature, humidity). In the case of a two-component developer, it is necessary to prevent the toner from sticking to the carrier surface, that is, a so-called toner filming phenomenon.
[0007]
Further, at the time of cleaning, it is necessary to have a cleaning property such that the residual toner is easily separated from the surface of the photoconductor and that the photoconductor is not damaged when used with a cleaning member such as a blade or a web. In order to satisfy these requirements, a dry developer is a one-component developer or a two-component developer in which inorganic fine powder such as silica, organic fine powder such as a fatty acid, a metal salt thereof and a derivative thereof, and fluorine resin fine powder are externally added to a toner. Various developers have been proposed to improve fluidity, durability, and cleaning properties.
[0008]
However, among the conventionally proposed additives, inorganic compounds such as silica, titania, and alumina significantly improve fluidity, but have a great effect on toner charging. For example, in the case of a commonly used silica-based fine powder, the negative polarity is strong, and in particular, the chargeability of the negatively chargeable toner is excessively increased under a low temperature and a low humidity. There is a problem that the chargeability is reduced by taking in, so that a large difference is caused between the two. As a result, this may cause poor density reproduction and background fog. In addition, the dispersibility of the inorganic fine powder also greatly affects the toner characteristics. If the dispersibility is non-uniform, desired characteristics cannot be obtained in fluidity and anti-caking properties, or cleaning becomes insufficient. In some cases, toner sticking occurs on the surface of the photoreceptor, which may cause black spot image defects.
[0009]
For the purpose of improving these points, it has been proposed to use a surface-treated inorganic fine powder, for example, a silica fine particle whose surface is subjected to a hydrophobic treatment (for example, see Patent Documents 1 to 3). However, a sufficient effect is not necessarily obtained only by using these inorganic fine powders. Further, as a method for relaxing the negative chargeability of the toner particles, a method of externally adding silica fine particles surface-treated with an amino-modified silicone oil (for example, see Patent Document 4), a method using aminosilane and / or amino-modified silicone oil A method of externally adding treated silica fine particles (for example, see Patent Document 5) is known. However, although treatment with these amino compounds can suppress an excessive rise in charge of the negatively chargeable toner, it cannot sufficiently improve the environmental dependency of the silica fine powder itself. In other words, although it is possible to slightly suppress the excessive negative chargeability of the silica fine powder after long-term use under low temperature and low humidity, similar charge neutralization occurs even during long-time use under high temperature and high humidity, As always, environmental dependency is not improved. Further, when silicone oil is used as a treating agent, there is a disadvantage that silica is agglomerated during the treatment due to its high viscosity, and powder fluidity is deteriorated.
[0010]
As a method for improving the triboelectric charging property, storage stability and fluidity of a toner, for example, an amino group such as dimethylaminoethyl acrylate having a triboelectric property different from that of the outer shell polymer of the toner particles is used. A method has been known in which silica fine particles coated with a polymer having a monomer having a heavy bond as a component are externally added to toner particles (for example, see Patent Document 6). However, this method aims at imparting triboelectrification, and cannot sufficiently improve the environmental dependency, similarly to the amino compound described above.
[0011]
Further, surface-treated silica fine particles obtained by treating hydrophobic silica fine particles having a hydrophobicity of 80% or more with a quaternary ammonium salt compound or a polymer having a quaternary ammonium salt as a functional group are used as toner particles. (For example, see Patent Document 7), (1) silica fine particles having a hydrophobicity of 80% or more treated with an amphoteric surfactant, and (2) silica fine particles having a hydrophobicity of 80% or more. A silica particle treated with a quaternary ammonium salt or a polymer having a quaternary ammonium group, and adding two types of silica fine particles to toner particles (for example, see Patent Document 8), a hydrocarbon surfactant A method of externally adding silica fine particles treated with a fluorine-modified quaternary ammonium salt or a fluorine-modified alkyl betaine to toner particles (for example, see Patent Document 9) Although a known, the processing method thereof, wherein the silica particle surface treatment are uneven, improvement of environmental dependence is insufficient.
[0012]
On the other hand, particularly, it has been reported that the toner is agitated in the developing device, the microstructure of the toner surface easily changes, and the transferability is largely changed (for example, see Patent Document 10). On the other hand, in recent years, the cleaning system has been omitted from the purpose of reducing the amount of waste toner from the viewpoint of environmental protection, reducing the waste toner from the viewpoint of environmental protection, and extending the life of the latent image carrier. A cleaner-less system has been proposed in which toner remaining on the surface of a photosensitive drum is dispersed by a brush in contact with the surface of the photosensitive drum, and the dispersed toner is collected simultaneously with development by a developing device (for example, see Patent Document 11). ). In general, if the residual toner is collected at the same time as the development, the collected toner and other toners have different charging characteristics, and the collected toner is accumulated in the developing device without being developed. Therefore, it is necessary to further increase the transfer efficiency and control the amount of collected toner to a minimum.
[0013]
Further, in order to improve fluidity, chargeability and transferability, it has been proposed to make the toner shape close to a spherical shape (for example, see Patent Document 12). However, spheroidizing the toner tends to cause the following problems. The developing device is provided with a transport amount control plate for controlling the developer transport amount to be constant, and the developer transport amount can be controlled by changing the distance between the mag roll and the transport amount control plate. However, when the spherical toner is used, the fluidity as a developer increases, and at the same time, the bulk density increases. As a result, a phenomenon occurs in which the developer accumulation occurs at the conveyance regulating portion, and the conveyance amount becomes unstable. By controlling the surface roughness of the mag roll and reducing the distance between the control plate and the mag roll, it is possible to improve the transport amount, but the packing performance due to the developer pool becomes stronger and the stress applied to the toner accordingly Also become stronger. As a result, it has been confirmed that a change in the fine structure of the toner surface, in particular, burying or peeling of the external additive easily occurs, causing a problem that the developing property and the transfer property are largely changed from the initial state.
[0014]
In order to improve these, it has been reported that a combination of spherical toner and non-spherical toner can suppress the packing property and achieve high image quality (for example, see Patent Document 13). However, although these are effective in suppressing the packing property, non-spherical toner tends to remain as transfer residue, and high transfer efficiency cannot be achieved. In the case of collecting the toner at the same time as the development, since the non-spherical toner remaining after the transfer is collected, the ratio of the non-spherical toner increases, causing a problem of further decreasing the transfer efficiency.
[0015]
Further, in order to improve the developability, transferability and cleaning property of the spherical toner, two types of particles having different average particle diameters of particles having an average particle diameter of 5 μm or more and less than 20 μm and particles having an average particle diameter of 20 μm or more and 40 μm or less are used. It is disclosed that inorganic fine particles are used in combination and are added in a specific amount (for example, see Patent Document 14). These can initially obtain high developability, transferability, and cleaning properties, but in any case, since the force applied to the toner over time cannot be reduced, burying or peeling of the external additive may occur. It occurs easily and greatly changes the developing property and the transfer property from the initial stage.
[0016]
On the other hand, it is disclosed that it is effective to use inorganic fine particles having a large particle diameter to suppress the embedding of the external additive in the toner against such stress (for example, Patent Documents 15 to 17). reference). However, since the specific gravity of the inorganic fine particles is large in any case, if the external additive particles are enlarged, the external additive is unavoidably peeled off due to the stirring stress in the developing device. In addition, since the inorganic fine particles do not have a perfect spherical shape, it is difficult to control the spikes of the external additives when they are attached to the toner surface. As a result, variations occur in the micro-surface convex shape functioning as a spacer, and stress is selectively applied to the convex portion, so that burying or peeling of the external additive is further accelerated, which is not sufficient.
[0017]
Also, a technique of adding 50 to 200 nm of organic fine particles to a toner to effectively exhibit a spacer function is disclosed (for example, see Patent Document 18). By using the spherical organic fine particles, it is possible to effectively express the spacer function initially. However, although the organic fine particles are less likely to be buried or peeled by the temporal stress, it is difficult to stably exhibit a high spacer function because the organic fine particles themselves are deformed. It is also conceivable to obtain a spacer effect by attaching a large amount of organic fine particles to the toner surface or by using organic fine particles having a large particle diameter. However, in this case, the characteristics of the organic fine particles are largely reflected. That is, the influence on the powder properties such as the fluidity inhibition and the deterioration of the thermal aggregation of the inorganic fine particle-added toner, and the organic fine particles themselves have the charge-imparting ability, and the degree of freedom of control from the viewpoint of charging is reduced. Charging, which affects the development.
[0018]
In recent years, there has been a high demand for colorization, especially on-demand printing, and a method of forming a multicolor image on a transfer belt for high-speed copying, transferring the multicolor image to an image fixing material at a time, and fixing the image. It has been reported (for example, see Patent Document 19). If the step of transferring from the photoreceptor to the transfer belt is the primary transfer, and the step of transferring from the transfer belt to the recording medium is the secondary transfer, the transfer is repeated twice, and the technology for improving the transfer efficiency becomes more and more important. . In particular. In the case of the secondary transfer, the multicolor image is transferred at a time, and the characteristics of the recording material (for example, in the case of paper, its thickness, surface properties, etc.) are variously changed. It is necessary to control developability and transferability extremely high.
[0019]
Further, in order to reduce power consumption, space, and obtain a high-quality image, there is disclosed a technique in which each color is transferred to an intermediate transfer member and fixed to the recording member simultaneously with transfer (see, for example, Patent Documents 20 and 21). ). The important point here is that the transfer belt must have both the transfer function and the fixing function. That is, since the primary transfer portion needs to improve the transferability in a cooled state and the secondary transfer simultaneous fixing portion needs to transmit heat instantaneously, a thin layer belt having high heat resistance is used as the belt material. It will be. Here, the functions required for the toner include controlling the transfer efficiency to be extremely high, and adapting to low-pressure fixing because strong pressure cannot be applied during fixing. In addition, since the belt surface also has a transfer function, it is important to minimize toner contamination during fixing and flaws due to external additives and the like.
[0020]
On the other hand, there has been proposed a method of faithfully reproducing high image quality, particularly halftone, solid black, and characters by controlling the volume resistivity of the carrier (for example, see Patent Documents 22 to 24). In each of these methods, the resistance is adjusted according to the type and amount of the carrier coating layer, and although the target volume specific resistance is initially obtained and high image quality is exhibited, the carrier coating is performed by the stress in the developing device. Peeling of the layer occurs, and the volume resistivity greatly changes. Therefore, it is difficult to exhibit high image quality for a long time.
[0021]
On the other hand, a method of adjusting the volume resistivity by adding carbon black to the carrier coating layer has been proposed (for example, see Patent Document 25). Although the change in volume resistivity due to the peeling of the coating layer is suppressed by this method, the external additive or the toner component added to the toner adheres to the carrier and changes the volume resistivity of the carrier. It was difficult to achieve high image quality over a long period of time as with the carrier No.
[0022]
[Patent Document 1]
JP-A-46-5782
[Patent Document 2]
JP-A-48-47345
[Patent Document 3]
JP-A-48-47346
[Patent Document 4]
JP-A-64-73354
[Patent Document 5]
JP-A-1-237561
[Patent Document 6]
JP-A-64-6964
[Patent Document 7]
JP-A-5-100471
[Patent Document 8]
JP-A-9-166888
[Patent Document 9]
Japanese Patent Application Laid-Open No. 9-152738
[Patent Document 10]
JP-A-10-312089
[Patent Document 11]
JP-A-5-94113
[Patent Document 12]
JP-A-62-184469
[Patent Document 13]
JP-A-6-308759
[Patent Document 14]
JP-A-3-100661
[Patent Document 15]
JP-A-7-28276
[Patent Document 16]
JP-A-9-319134
[Patent Document 17]
JP-A-10-312089
[Patent Document 18]
Reference JP-A-6-266152
[Patent Document 19]
JP-A-8-115007
[Patent Document 20]
JP-A-10-213977
[Patent Document 21]
JP-A-8-44220
[Patent Document 22]
JP-A-56-125751
[Patent Document 23]
JP-A-62-267766
[Patent Document 24]
Japanese Patent Publication No. 7-120080
[Patent Document 25]
JP-A-4-40471
[0023]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described circumstances of the related art.
That is, an object of the present invention is to provide a blade cleaning step that simultaneously satisfies toner fluidity, chargeability, developability, transferability, cleaning properties, and fixability over a long period of time, and particularly promotes abrasion of a latent image carrier. In addition, an electrostatic image dry toner composition that has improved the problem of recovering transfer residual toner simultaneously with development or recovering residual toner on the surface of a latent image carrier using an electrostatic brush, and an electrostatic latent image using the same It is to provide a developer. Another object of the present invention is to provide an image forming method capable of developing, transferring, and fixing to meet a demand for high image quality.
[0024]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that the above object can be achieved by using a specific inorganic oxide fine powder for a toner, thereby completing the present invention. Reached. Ie
<1> An electrostatic image dry toner composition containing a binder resin, a colorant, and a release agent, wherein the electrostatic image dry toner composition has two or more inorganic particles having different volume average primary particle diameters. An electrostatic image dry toner composition containing an oxide fine powder, one of which is an inorganic oxide fine powder whose surface is coated with a charge controlling agent.
[0025]
<2> Among the two or more inorganic oxide fine powders having different volume average primary particle sizes, one type has a volume average primary particle size of 5 nm or more and less than 30 nm, and the other type has a volume average primary particle size. Is less than 70 nm and less than 70 nm.
[0026]
<3> The method according to <1> or <2>, wherein the surface of the inorganic oxide fine powder whose surface is coated with the charge control agent is coated with the charge control agent to a thickness of 0.5 to 5 nm. An electrostatic image dry toner composition as described above.
[0027]
<4> A developer for developing an electrostatic latent image comprising a carrier and a toner composition, wherein the carrier has, on a surface of a core material, a resin coating layer in which a conductive material is dispersed and contained in a matrix resin, and The toner composition contains a binder resin, a colorant, and a release agent, and further contains two or more kinds of inorganic oxide fine powders having different volume average primary particle diameters, and one of them. Is a developer for developing an electrostatic latent image, which is a toner composition which is an inorganic oxide fine powder whose surface is coated with a charge controlling agent.
[0028]
<5> The electrostatic material according to <4>, wherein the surface of the inorganic oxide fine powder whose surface is coated with the charge control agent is coated with the charge control agent to a thickness of 0.5 to 5 nm. It is a developer for developing a latent image.
[0029]
<6> charging means for uniformly charging the latent image carrier, latent image forming means for exposing the charged latent image carrier surface to form an electrostatic latent image, and applying the electrostatic latent image to the toner composition Forming an image using an image forming apparatus including developing means for developing a toner image by using the toner image, transferring means for transferring the formed toner image to a recording material, and fixing means for fixing the transferred toner image to the surface of the recording material An image forming method, wherein the toner composition contains a binder resin, a colorant, and a release agent, and further contains two or more types of inorganic oxide fine powders having different volume average primary particle diameters. One of which is a toner composition which is an inorganic oxide fine powder whose surface is coated with a charge controlling agent, wherein the transfer means develops each color toner on the latent image carrier, After transferring to the body, apply each color toner to recording material at once An image forming method, which is a transfer unit for transferring.
[0030]
<7> charging means for uniformly charging the latent image carrier, latent image forming means for exposing the charged latent image carrier to form an electrostatic latent image, and applying the electrostatic latent image to the toner composition. Developing means for developing a toner image by using the toner image, transferring means for transferring the formed toner image to a recording material, cleaning means for removing toner remaining on the surface of the latent image carrier after transfer, and transferring the transferred toner image to the recording material surface An image forming method for forming an image using an image forming apparatus including a fixing unit for fixing a toner, wherein the toner composition contains a binder resin, a colorant, and a release agent, and has a volume average of It contains two or more inorganic oxide fine powders having different particle diameters, and one of them is an inorganic oxide fine powder whose surface is coated with a charge controlling agent, and has a shape factor SF1 (ML ² / A) is a toner composition having a shape of 100 to 140, wherein the cleaning means uses an electrostatic brush to rub the surface of the latent image carrier without rubbing the latent image carrier with a blade. An image forming method characterized by collecting residual toner.
[0031]
<8> charging means for uniformly charging the latent image carrier, latent image forming means for exposing the charged latent image carrier surface to form an electrostatic latent image, and applying the electrostatic latent image to the toner composition Developing means for developing a toner image by using the toner image, transferring means for transferring the formed toner image to a recording material, cleaning means for removing toner remaining on the surface of the latent image carrier after transfer, and transferring the transferred toner image to the recording material surface An image forming method for forming an image using an image forming apparatus including a fixing unit for fixing a toner, wherein the toner composition contains a binder resin, a colorant, and a release agent, and has a volume average primary It contains two or more inorganic oxide fine powders having different particle diameters, and one of them is an inorganic oxide fine powder whose surface is coated with a charge controlling agent, and has a shape factor SF1 (ML ² / A) is a toner composition having a shape of 100 to 140, wherein the cleaning means uses a developing device without rubbing the latent image carrier with a blade, and the residual on the surface of the latent image carrier. An image forming method comprising collecting toner.
[0032]
<9> charging means for uniformly charging the latent image carrier, latent image forming means for exposing the charged latent image carrier surface to form an electrostatic latent image, and applying the electrostatic latent image to a toner composition. Using an image forming apparatus that includes a transfer fixing unit that transfers the formed toner image to an intermediate transfer body, and simultaneously transfers and fixes the toner image to a recording material. An image forming method for forming, wherein the toner composition contains a binder resin, a colorant, and a release agent, and contains two or more inorganic oxide fine powders having different volume average primary particle diameters. And one of them is a toner composition which is an inorganic oxide fine powder whose surface is coated with a charge controlling agent, wherein the transfer fixing unit develops each color toner on a latent image carrier, After transferring to the intermediate transfer member, each color is recorded on the recording member at once. An image forming method characterized by transferring and fixing at the same time.
[0033]
Further, in the electrostatic image dry toner composition of the present invention, in the inorganic oxide fine powder coated on the surface with the charge control agent, the inorganic oxide fine powder surface is formed by an organosilane compound or polysiloxane generated from alkoxysilane. It is preferable that the coating is coated and a charge control agent is attached to the coating.
[0034]
At least one of the two or more inorganic oxide fine powders having different particle diameters is spherical silica having a specific gravity of 1.2 to 1.9 and a volume average primary particle diameter of 80 to 300 nm. Is preferred.
[0035]
Further, the shape factor SF1 (ML) of the toner composition ² / A) is preferably in the range of 100 to 140.
[0036]
In the developer for developing an electrostatic latent image of the present invention, among the two or more inorganic oxide fine powders having different particle diameters, one kind has a volume average primary particle diameter of 5 nm or more and less than 30 nm, and the other one of It is desirable that the volume average primary particle size is 30 nm or more and less than 70 nm.
[0037]
Further, in the inorganic oxide fine powder whose surface is coated with the charge control agent, the surface of the inorganic oxide fine powder is coated with an organosilane compound or polysiloxane generated from alkoxysilane, and the charge control agent adheres to the coating. Preferably.
[0038]
Further, the shape factor SF1 (ML) of the toner composition used in the developer for developing an electrostatic latent image ² / A) is preferably a toner having a shape of 100 to 140.
[0039]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
<Electrostatic image dry toner>
The electrostatic image dry toner composition of the present invention is an electrostatic image dry toner composition containing a binder resin, a colorant and a release agent, wherein the electrostatic image dry toner composition has a volume average primary It is characterized in that it contains two or more kinds of inorganic oxide fine powders having different particle diameters, and one of them is an inorganic oxide fine powder whose surface is coated with a charge controlling agent.
[0040]
That is, the electrostatic image dry toner of the present invention contains two or more types of inorganic oxide fine powders as external additives, and at least one type of the inorganic oxide fine powders whose surfaces are uniformly coated with a charge control agent. It must be a powder.
[0041]
By treating the inorganic oxide fine powder with the charge control agent, an excessive increase in charge due to the inorganic oxide fine powder such as silica can be suppressed, and the charge level can be controlled to be low. Further, the charge level of the toner can be reduced, for example, the charge level of the negatively chargeable toner containing fine powder of inorganic oxide such as alumina can be increased.
[0042]
That is, it is possible to eliminate the possibility that the inorganic oxide fine powder imparts triboelectricity to the toner as much as possible, and to improve the environmental dependency of the toner without giving an adverse effect of reducing the triboelectricity of the toner. Coating the surface of the inorganic oxide fine powder with the charge controlling agent can effectively bring out these effects.
[0043]
In the present invention, the external additive having a smaller average particle diameter has a volume average primary particle diameter of 5 nm or more and less than 30 nm, and the external additive having a larger average particle diameter has a volume average primary particle diameter of It is preferably in the range of 30 nm or more and less than 70 nm. With the external additive composition set in this range, the fluidity, chargeability and transferability of the small particle size toner (average particle size of 8 μm or less) in the initial stage of use can be controlled in a well-balanced manner.
[0044]
The amount of the external additive having the smaller average particle diameter is preferably in the range of 0.3 to 3 parts by mass, and more preferably in the range of 0.5 to 1.5 parts by mass with respect to 100 parts by mass of the toner. Is more preferable. If the amount is less than 0.3 part by mass, sufficient fluidity cannot be obtained. If the amount is more than 3 parts by mass, the charge retention of the toner decreases. The amount of the external additive having the larger average particle diameter is preferably in the range of 0.3 to 4 parts by mass, and more preferably in the range of 0.5 to 1.8 parts by mass with respect to 100 parts by mass of the toner. Is more preferable. If the amount is less than 0.3 part by mass, sufficient transferability cannot be obtained. If the amount is more than 4 parts by mass, deterioration in toner fluidity and deterioration in charge retention cannot be avoided.
[0045]
The development and transfer are affected by the uniform transportability of the developer, the current at the time of transfer, and the like. However, basically, the toner particles are separated from the binding force of the carrier carrying the toner particles, and the object (latent image carrying) is removed. This is a process of attaching the toner particles to a toner or a recording material), and thus depends on the balance between the electrostatic attraction and the adhesive force between the toner particles and the charging member or between the toner particles and the latent image carrier. It is very difficult to control this balance, but this process directly affects the image quality, and if the efficiency of development / transfer is improved, improvement in reliability and labor saving by cleaning-less etc. are expected. In the above steps, higher developability and transferability are required. In the present invention, since the inorganic fine particles are uniformly coated with the resin, there is little variation in the adhesion to the toner particles, and the above-described balance can be easily obtained.
[0046]
Development / transfer occurs when F (electrostatic attraction)> F (adhesive force). Therefore, in order to improve the efficiency of development / transfer, it is sufficient to increase the electrostatic attractive force (increase the development / transfer force) or to control the adhesion force in a direction to decrease it. If the transfer electric field is increased, the secondary polarity is likely to occur, such as generation of reverse polarity toner. Therefore, it is more effective to lower the adhesive force.
[0047]
Examples of the adhesive force include a Van der Waals force (non-electrostatic adhesive force) and a mirror image force due to the electric charge of the toner particles. It can be interpreted as being discussed with van der Waals' power. The Van der Waals force Fv between spherical particles is represented by the following equation (1).
Fv = H · r ₁ ・ R ₂ / 6 (r ₁ + R ₂ ) ・ A ² ... Equation (1)
(H: constant, r ₁ , R ₂ : Radius of contacting particles, a: distance between particles)
In order to reduce the adhesive force, a fine powder having a very small r as compared with the toner particles is provided between the toner particles and the surface of the latent image carrier or the surface of the charging member, so that each has a distance a. A method of reducing the contact area (the number of contact points) is effective, and as means for stably maintaining the effect, monodisperse spherical particles having a specific gravity of 1.2 to 1.9 and a volume average primary particle diameter of 80 to 300 nm in the present invention are used. It has further been found that it is effective to use silica.
[0048]
With respect to the above specific gravity, peeling from the toner can be suppressed by controlling the specific gravity to 1.9 or less, and aggregation and dispersion can be suppressed by controlling the specific gravity to 1.2 or more. Further, since the particles are monodisperse and spherical, they can be uniformly dispersed on the toner surface, and a stable spacer effect can be obtained.
[0049]
The definition of the monodispersion can be discussed by the standard deviation with respect to the average particle size including the aggregates, and the volume average particle size D50 is desirably D50 × 0.22 or less as the standard deviation. The definition of the spherical shape can be discussed in terms of Wadell's sphericity, and the sphericity is preferably 0.6 or more, and more preferably 0.8 or more. In addition, the reason for limiting to silica is that the refractive index is around 1.5, and even if the particle size is increased, the transparency is reduced due to light scattering. In particular, the PE value at the time of collecting an image on an OHP (index of light transmittance) Etc. are not affected. Therefore, it is desirable to use it as a color toner.
[0050]
General fumed silica has a specific gravity of 2.2, and the maximum particle size is limited to 50 nm in terms of production. Although the particle size can be increased as an aggregate, uniform dispersion and a stable spacer effect cannot be obtained. On the other hand, other typical inorganic fine particles include titanium oxide (specific gravity 4.2, refractive index 2.6), alumina (specific gravity 4.0, refractive index 1.8), and zinc oxide (specific gravity 5.6, refractive index). Rate of 2.0), but all have a high specific gravity, and if the particle diameter is larger than 80 nm, which effectively exerts the spacer effect, peeling from the toner is likely to occur, and the peeled particles are charged to the charging member or latent member. Transfer to an image carrier or the like is likely to occur, causing a reduction in charge or image quality defects. Also, because of its high refractive index, the use of a large particle size inorganic material is not very suitable for forming a color image.
[0051]
In the present invention, the inorganic oxide fine powder is added to the toner particles and mixed. The mixing can be performed by a known mixer such as a V-type blender, a Henschel mixer, a Loedige mixer, or the like.
[0052]
At this time, various additives may be added as needed. Examples of these additives include other fluidizing agents, cleaning aids and transfer aids such as polystyrene fine particles, polymethyl methacrylate fine particles, and polyvinylidene fluoride fine particles.
[0053]
The amount of the monodisperse spherical silica having a specific gravity of 1.2 to 1.9 and a volume average primary particle size of 80 to 300 nm is in the range of 0.5 to 5 parts by mass with respect to 100 parts by mass of the toner. And more preferably in the range of 1 to 3 parts by mass. If the amount is less than 0.5 part by mass, sufficient transferability cannot be obtained. If the amount is more than 5 parts by mass, deterioration in toner fluidity and deterioration in chargeability cannot be avoided.
[0054]
As a method of external addition to the toner, two or more types of inorganic oxide fine powder and monodispersed spherical silica having a specific gravity of 1.2 to 1.9 and a volume average primary particle size of 80 to 300 nm are simultaneously added and mixed. You may.
Various addition methods were examined, and monodispersed spherical silica having a specific gravity of 1.2 to 1.9 and a volume average primary particle size of 80 to 300 nm was first mixed, and other inorganic oxides were weakly sheared. By adding the substance fine powder, the effect of the present invention could be obtained high. In addition, it does not matter if the sieving process is performed after the external addition and mixing.
[0055]
Further, when spherical toner is used, the packing property is inevitably increased at the transfer regulating portion in the developing device, and accordingly, a strong force is applied not only to the toner surface but also to the carrier. Therefore, by dispersing and containing the conductive material in the resin coating layer of the carrier, even if the resin coating layer peels off, it is possible to maintain high image quality for a long period of time without largely changing the volume resistivity. Was found.
[0056]
Further, the blade cleaning method is generally used because of its high performance stability, but by using the toner of the present invention, it is possible to collect the residual toner on the surface of the latent image carrier using an electrostatic brush. Thus, the wear life of the latent image carrier can be greatly extended.
[0057]
Further, by using the toner of the present invention, without providing a cleaning system on the surface of the latent image carrier, even when the residual toner is collected again in the developing device, the specific toner is not selectively accumulated, It has become possible to obtain stable development, transfer and fixing performance.
[0058]
Furthermore, by using the toner of the present invention, each color is developed on a latent image carrier, and after being transferred to a transfer belt, each color is simultaneously transferred to a recording body and fixed at the same time, thereby obtaining a high-quality image. I got it. In addition, it was also confirmed at the same time that it did not affect the PE value or the like, which is an index of the transparency when the image was collected on the OHP surface.
[0059]
Hereinafter, a method for producing an inorganic oxide fine powder whose surface is coated with the charge control agent according to the present invention will be described.
The inorganic oxide fine powder whose surface is coated with the charge control agent according to the present invention is obtained by mixing the inorganic oxide fine powder and the alkoxysilane or polysiloxane, and then coating the surface of the inorganic oxide fine powder with alkoxysilane or polysiloxane. It can be obtained by coating and then mixing the inorganic oxide fine powder coated with alkoxysilane or polysiloxane with a charge control agent.
[0060]
The surface of the inorganic oxide fine powder is coated with alkoxysilane or polysiloxane by mechanically mixing and stirring the inorganic oxide fine powder and the alkoxysilane or polysiloxane, or spraying the inorganic oxide fine powder with the alkoxysilane or polysiloxane. What is necessary is just to mix and stir mechanically while doing. Almost all of the added alkoxysilane or polysiloxane is coated on the particle surface of the inorganic oxide fine powder.
[0061]
In addition, the coated alkoxysilane may be coated as an organosilane compound generated from the alkoxysilane, a part of which is generated through a coating process. Even in this case, there is no influence on the subsequent adhesion of the charge control agent.
[0062]
Mixing and stirring of inorganic oxide fine powder and alkoxysilane or polysiloxane, or mixing and stirring of the charge control agent and inorganic oxide fine powder having a particle surface coated with an organosilane compound or polysiloxane formed from alkoxysilane. As a device for performing, a device capable of applying a shearing force to the powder layer is preferable, particularly, a device capable of simultaneously performing shearing, spatula and compression, for example, a wheel-type kneader, a ball-type kneader, A blade type kneader or a roll type kneader can be used. In practicing the present invention, a wheel-type kneader can be used more effectively.
[0063]
Specific examples of the wheel type kneader include edge runners (synonyms for “mix muller”, “simpson mill”, and “sand mill”), multi-mul, stots mill, wet pan mill, conner mill, ring muller, and the like. Preferred are edge runners, multiples, Stotts mills, wet pan mills, and ring mullers, and more preferred are edge runners. Examples of the ball-type kneader include a vibration mill and the like. Specific examples of the blade type kneader include a Henschel mixer, a planetary mixer, and a Nauta mixer. Specific examples of the roll-type kneader include an extruder.
[0064]
The conditions during mixing and stirring are such that the linear load is in the range of 19.6 to 1960 N / cm (2 to 200 kg / cm) so that the surface of the particles of the inorganic oxide fine powder is coated with the alkoxysilane or polysiloxane as uniformly as possible. , Preferably in the range of 98 to 1470 N / cm (10 to 150 kg / cm), more preferably in the range of 147 to 980 N / cm (15 to 100 kg / cm), and the treatment time is in the range of 5 to 120 minutes, preferably May be appropriately adjusted within the range of 10 to 90 minutes. The processing conditions may be appropriately adjusted within the range of 2 to 2000 rpm, preferably 5 to 1000 rpm, more preferably 10 to 800 rpm.
[0065]
The addition amount of the alkoxysilane or polysiloxane is preferably in the range of 0.15 to 45 parts by mass based on 100 parts by mass of the inorganic oxide fine powder. If the amount is less than 0.15 parts by mass, it is difficult to attach a charge control agent that is sufficient to obtain an inorganic oxide fine powder whose surface is uniformly coated with the target charge control agent. Further, the charge control agent can be attached to 3 to 30 parts by mass with respect to 100 parts by mass of the inorganic oxide fine powder by the addition amount of 0.15 to 45 parts by mass, so that the amount exceeds 45 parts by mass more than necessary. There is no point in adding.
[0066]
Next, a charge control agent is added to the inorganic oxide fine powder coated with the alkoxysilane or polysiloxane, and the mixture is stirred to adhere a fatty acid metal salt to the coated alkoxysilane or polysiloxane. If necessary, drying or heat treatment may be further performed.
[0067]
The charge control agent is preferably added little by little over time, especially over about 5 to 60 minutes. The conditions at the time of mixing and stirring are such that the line load is in the range of 19.6 to 1960 N / cm (2 to 200 Kg / cm), preferably 98 to 1470 N / cm (10 to 150 Kg / cm) so that the charge control agent is uniformly attached. cm), more preferably in the range of 147 to 980 N / cm (15 to 100 kg / cm), and the processing time is appropriately adjusted in the range of 5 to 120 minutes, preferably 10 to 90 minutes. Good. The processing conditions may be appropriately adjusted within the range of 2 to 2000 rpm, preferably 5 to 1000 rpm, more preferably 10 to 800 rpm.
[0068]
The addition amount of the charge control agent is preferably in the range of 3 to 30 parts by mass, more preferably 3 to 15 parts by mass, per 100 parts by mass of the inorganic oxide fine powder. If the amount of the charge control agent is outside the above range, an inorganic oxide fine powder whose surface is uniformly coated with the target charge control agent cannot be obtained.
[0069]
Further, it is desirable that the surface of the inorganic oxide fine powder coated with the charge control agent is coated with the charge control agent in a thickness of 0.5 to 5 nm so that the effect can be stably exhibited. Further, it is preferable that the entire surface be covered.
[0070]
The heating temperature in the drying or heating step is usually preferably in the range of 40 to 150 ° C, more preferably in the range of 60 to 120 ° C. The treatment time is preferably in the range of 10 minutes to 12 hours, more preferably in the range of 30 minutes to 3 hours.
[0071]
Through these steps, the alkoxysilane used for coating the inorganic oxide fine powder is finally coated as an organosilane compound generated from the alkoxysilane.
[0072]
Examples of the inorganic oxide fine powder used in the present invention include SiO 2 ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO ・ SiO ₂ , K ₂ O ・ (TiO ₂ ) _n , Al ₂ O ₃ ・ 2SiO ₂ , CaCO ₃ , MgCO ₃ , BaSO ₄ , MgSO ₄ And other known materials can be used. Further, a material subjected to a hydrophobic treatment as necessary can be used. As an inorganic oxide fine powder whose surface is coated with a charge controlling agent, SiO ₂ Is preferred because it is most effective.
[0073]
Examples of the hydrophobizing agent that can be used for the hydrophobizing treatment include, for example, methyltrichlorosilane, octyltrichlorosilane, alkylchlorosilanes such as dimethyldichlorosilane, dimethyldimethoxysilane, alkylmethoxysilanes such as octyltrimethoxysilane, Hexamethyldisilazane, silicone oil and the like.
[0074]
As the charge control agent for coating the inorganic oxide fine powder, conventionally known charge control agents can be used. For example, as a positive charge control agent, a nigrosine dye, a triphenylmethane dye, a quaternary ammonium salt, a quaternary ammonium group and / or Amino group-containing resins are used as negative charge control agents, such as trimethylethane dyes, metal complex salts of salicylic acid, metal complex salts of benzylic acid, copper phthalocyanine, perylene, quinacridone, azo pigments, metal complex salt azo dyes, and azochrome complexes. Heavy metal-containing acid dyes, calixarene type phenolic condensates, cyclic polysaccharides, resins containing a carboxyl group and / or a sulfonyl group, and the like. It is preferable to use these depending on the charging characteristics of the inorganic oxide fine powder to be treated.
[0075]
The monodisperse spherical silica having a specific gravity of 1.3 to 1.9 and a volume average primary particle size of 80 to 300 nm of the present invention can be obtained by a sol-gel method which is a wet method. Since the specific gravity is produced by a wet method and without firing, it can be controlled to be lower than that of the vapor phase oxidation method. Further, it can be further adjusted by controlling the type of the hydrophobizing agent or the amount of the hydrophobizing agent in the hydrophobizing process. The particle size can be freely controlled by the weight ratio of alkoxysilane, ammonia, alcohol, and water in the hydrolysis and condensation polymerization steps of the sol-gel method, the reaction temperature, the stirring speed, and the supply speed.
[0076]
Monodisperse and spherical shapes can also be achieved by making them by this method. Specifically, tetramethoxysilane is added dropwise and stirred in the presence of water and alcohol while applying a temperature using ammonia water as a catalyst. Next, the silica sol suspension produced by the reaction is centrifuged to separate into wet silica gel, alcohol and aqueous ammonia. A solvent is added to the wet silica gel to make it into a silica sol state again, and a hydrophobizing agent is added to hydrophobize the silica surface. As the hydrophobizing agent, a general silane compound can be used. Next, the target monodispersed silica can be obtained by removing the solvent from the hydrophobized silica sol, drying and sieving. Further, the silica thus obtained may be treated again.
[0077]
As the silane compound, a water-soluble one can be used. As such a silane compound, the chemical structural formula R _a Six _4-a (In the formula, a is an integer of 0 to 3, R represents a hydrogen atom, an organic group such as an alkyl group and an alkenyl group, and X represents a hydrolyzable group such as a chlorine atom, a methoxy group and an ethoxy group. ) Can be used, and any type of chlorosilane, alkoxysilane, silazane, and special silylating agent can be used. Specifically, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyl Triethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane, hexamethyldisilazane, N, O- (bistrimethylsilyl) acetamide, N, N-bis ( Trimethylsilyl) urea, tert-butyldimethylchlorosilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxy Orchid, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercapto Propyltrimethoxysilane and γ-chloropropyltrimethoxysilane can be exemplified as typical examples. The treatment agent in the present invention is particularly preferably dimethyldimethoxysilane, hexamethyldisilazane, methyltrimethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane, or the like.
[0078]
The electrostatic image dry toner of the present invention comprises a binder resin, a colorant and a release agent, and preferably has a volume average particle diameter D50 in the range of 2 to 8 μm.
The average shape index SF1 (ML of the toner) ² By using the toner having the ratio (A) of from 100 to 140, it is possible to obtain an image having high development, transferability and high image quality. The toner used in the present invention is not particularly limited by a manufacturing method as long as it satisfies the above-mentioned shape index and particle diameter, and a known method can be used.
[0079]
The shape factor SF1 is obtained by taking an optical microscope image of a magnetic substance dispersed type core scattered on the surface of a slide glass into a Luzex image analyzer through a video camera, and obtaining a maximum length (ML) for 100 or more spherical cores. Measure the projected area (A) and ML ² / A.
[0080]
The production of the toner includes, for example, kneading, pulverizing and classifying a binder resin, a colorant, a release agent, and further, if necessary, a charge controlling agent, etc. A method of changing the shape by impact force or thermal energy, emulsion polymerization of the polymerizable monomer of the binder resin, and a formed dispersion, a colorant, a release agent, and if necessary, a charge control agent, etc. Emulsion polymerization aggregation method to obtain toner particles by mixing and aggregating and heat fusing with dispersion liquid, polymerizable monomer to obtain binder resin, colorant, release agent, and, if necessary, charge control A method of suspending and polymerizing a solution of an agent or the like in an aqueous solvent to form a polymer by suspending a solution of a binder resin, a colorant, a release agent, and, if necessary, a charge control agent in the aqueous solvent. A dissolution suspension method of granulating can be used. Alternatively, a production method may be performed in which the toner obtained by the above method is used as a core, and aggregated particles are further adhered and fused to form a core-shell structure. Among the above, particularly preferred are wet-processed toners from which a spherical toner can be easily obtained, and further, toner particles obtained by an emulsion polymerization aggregation method are preferably used in that toner particles having a sharp distribution can be obtained. The effect is stabilized by combining with these toner particles.
[0081]
Examples of the binder resin used include styrenes such as styrene and chlorostyrene; monoolefins such as ethylene, propylene, butylene and isoprene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl butyrate; Α-methylene aliphatic monocarboxylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate And vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone; and homopolymers and copolymers. Particularly typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, and styrene-anhydride. Maleic acid copolymer, polyethylene, polypropylene and the like can be mentioned. Furthermore, polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like can be mentioned.
[0082]
Examples of toner colorants include magnetic powders such as magnetite and ferrite, carbon black, aniline blue, caryl blue, chrome yellow, ultramarine blue, Dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, and malachite green oxalate. Rate, lamp black, rose bengal, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 17, C.I. I. Pigment Blue 15: 1, C.I. I. Pigment Blue 15: 3 and the like can be exemplified as typical ones.
[0083]
Typical examples of the release agent include low molecular polyethylene, low molecular polypropylene, Fischer-Tropish wax, montan wax, carnauba wax, rice wax, candelilla wax and the like.
[0084]
Further, a charge control agent may be added to the electrostatic image dry toner of the present invention as needed. As the charge control agent, known ones can be used, and an azo metal complex compound, a metal complex compound of salicylic acid, a resin type charge control agent containing a polar group, and the like can be used. When the toner is manufactured by a wet manufacturing method, it is preferable to use a material that is hardly dissolved in water in terms of controlling ionic strength and reducing wastewater contamination. The toner in the present invention may be either a magnetic toner containing a magnetic material or a non-magnetic toner containing no magnetic material.
[0085]
<Electrostatic latent image developing developer>
The developer for developing an electrostatic latent image of the present invention is a developer for developing an electrostatic latent image comprising a carrier and a toner composition, wherein the carrier has a core material surface and a conductive material dispersedly contained in a matrix resin. And the toner composition contains a binder resin, a colorant, and a release agent, and further contains two or more inorganic oxide fine powders having different volume average primary particle diameters. One of which is a toner composition which is an inorganic oxide fine powder whose surface is coated with a charge controlling agent.
[0086]
The toner composition is the aforementioned electrostatic image dry toner composition of the present invention. On the other hand, as the carrier, a resin-coated carrier having a resin coating layer in which a conductive material is dispersed and contained in a matrix resin on the surface of a core material is used.
As the matrix resin, polyethylene, polypropylene, polystyrene, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic acid Examples include copolymers, straight silicone resins comprising organosiloxane bonds or modified products thereof, fluororesins, polyesters, polyurethanes, polycarbonates, phenolic resins, amino resins, melamine resins, benzoguanamine resins, urea resins, amide resins, epoxy resins and the like. However, the present invention is not limited to these.
[0087]
Examples of the conductive material include metals such as gold, silver, and copper, and titanium oxide, zinc oxide, barium sulfate, aluminum borate, potassium titanate, tin oxide, and carbon black, but are not limited thereto. It is not done.
The content of the conductive material is preferably in the range of 1 to 50 parts by mass, more preferably 3 to 20 parts by mass, per 100 parts by mass of the matrix resin.
[0088]
The core material of the carrier includes magnetic metals such as iron, nickel, and cobalt; magnetic oxides such as ferrite and magnetite; and glass beads. However, in order to adjust the volume resistivity using a magnetic brush method, a magnetic material is used. It is preferable that
The average particle size of the core material is generally in the range of 10 to 500 μm, preferably 30 to 100 μm in terms of volume average particle size.
[0089]
The method for forming the resin coating layer on the surface of the carrier core material includes a dipping method in which the carrier core material is dipped in a coating layer forming solution containing a matrix resin, a conductive material and a solvent; Spray method for spraying on the surface of the core material, fluidized bed method for spraying the coating layer forming solution in a state where the carrier core material is suspended by flowing air, mixing the carrier core material and the coating layer forming solution in a kneader coater, A kneader coater method for removing the solvent may be used.
[0090]
The solvent used in the coating layer forming solution is not particularly limited as long as it dissolves the matrix resin, and examples thereof include aromatic hydrocarbons such as toluene and xylene, and ketones such as acetone and methyl ethyl ketone. And ethers such as tetrahydrofuran and dioxane.
The average film thickness of the resin coating layer is usually in the range of 0.1 to 10 μm, but in the present invention, it is in the range of 0.5 to 3 μm in order to exhibit a stable volume resistivity of the carrier over time. Is preferred.
[0091]
In order to achieve high image quality, the volume resistivity of the carrier formed as described above is equal to the upper and lower limits of a normal developing contrast potential. ³ -10 ⁴ In the range of V / cm, 10 ⁶ -10 ¹⁴ It is preferably in the range of Ωcm. Carrier volume resistivity is 10 ⁶ If it is less than Ωcm, reproducibility of fine lines is poor, and toner fogging on the background due to injection of electric charge is likely to occur. In addition, the volume resistivity of the carrier is 10 ¹⁴ If it is larger than Ωcm, reproduction of solid black and halftone becomes poor. Further, the amount of carriers transferred to the photoconductor increases, and the photoconductor may be easily damaged. As the electrostatic brush, a resin containing a conductive filler such as carbon black or metal oxide or a fibrous substance coated on the surface can be used, but is not limited thereto.
[0092]
The developer for developing an electrostatic latent image of the present invention is manufactured by mixing the above-described toner and carrier. The mixing ratio (mass ratio) of the toner and the carrier in the developer is preferably in the range of toner: carrier = 1: 100 to 20: 100, and more preferably in the range of 3: 100 to 12: 100. Is more preferable.
[0093]
<Image forming method>
The image forming method according to the present invention includes a charging unit for uniformly charging the latent image carrier, a latent image forming unit for exposing the charged latent image carrier surface to form an electrostatic latent image, and the electrostatic latent image. Means for developing a toner image using a toner composition, a transfer means for transferring the formed toner image to a recording material, and a fixing means for fixing the transferred toner image to the recording material surface. An image forming method for forming an image using the toner composition, wherein the toner composition contains a binder resin, a colorant, and a release agent, and further includes two or more inorganic oxides having different volume average primary particle sizes. A toner composition comprising a fine powder, one of which is an inorganic oxide fine powder whose surface is coated with a charge controlling agent, wherein the transfer means transfers each color toner to the latent image carrier; After developing and transferring to the intermediate transfer member, each color toner Characterized in that the a transfer means for transferring to the recording material at a time.
[0094]
That is, in the image forming method of the present invention, a latent image carrier, a charging unit for charging the surface of the latent image carrier, and a latent image on the surface of the charged latent image carrier are provided as an image forming apparatus for forming an image. An image forming apparatus including: a latent image forming unit that forms an image; a developing unit that develops the electrostatic latent image using a toner composition; and a transfer unit that transfers the toner image to a recording material. As the toner composition, the above-described toner composition of the present invention is used. In particular, in the full-color image formation in the image forming method of the present invention, from the viewpoint of paper versatility and high image quality, a color toner image of each color is temporarily transferred to an intermediate transfer belt or an intermediate transfer drum surface as an intermediate transfer body. After stacking, the stacked color toner images are transferred at once to the surface of a recording material such as paper.
[0095]
Further, as the image forming apparatus, in particular, the latent image carrier, a charging unit for charging the surface of the latent image carrier, and a latent image forming unit for forming a latent image on the charged surface of the latent image carrier. Preferably, a device having a plurality of developing means for developing the electrostatic latent image using a toner composition and transfer means for transferring the toner image to an intermediate transfer member, that is, a tandem type image forming apparatus is preferably used.
[0096]
Hereinafter, the image forming apparatus used in the present invention will be described by way of an example.
FIG. 1 is a schematic sectional view showing an example of an image forming apparatus used in the present invention. In this image forming apparatus, as shown in FIG. 1, four developing units 40Y, 40M, 40C, and 40K for forming images of yellow, magenta, cyan, and black, respectively, are arranged in parallel at a predetermined interval. (In tandem). Here, since the developing units 40Y, 40M, 40C, and 40K have basically the same configuration except for the color of the toner in the contained developer, the yellow developing unit 40Y will be represented below. explain.
[0097]
The yellow developing unit 40Y includes a photoconductor drum (latent image carrier) 1Y as an image carrier, and the photoconductor drum 1Y has an axis in a direction perpendicular to the paper surface of FIG. Then, it is rotationally driven at a predetermined process speed by a driving means (not shown) along the direction of arrow A shown in the figure. As the photoconductor drum 1Y, for example, an organic photoconductor having sensitivity in an infrared region is used.
The process speed may be switched automatically or manually according to predetermined conditions. The image forming method of the present invention can realize high-quality image formation and maintainability of the developer even in an apparatus in which the process speed is switched halfway. Here, "automatically under predetermined conditions" means, for example, when image information including a high-definition image portion such as a photographic image is input, in order to obtain a high-quality image, automatically switch from the normal mode to the low-speed mode. Switching is possible.
[0098]
A roll charging type charger (charging means) 20Y is provided above the photosensitive drum 1Y in FIG. 1, and a predetermined voltage is applied to the charger 20Y by a power supply (not shown). The surface of 1Y is charged to a predetermined potential (the same applies to chargers 20M, 20C, 20K and photosensitive drums 1M, 1C, 1K).
[0099]
A latent image forming unit that forms an electrostatic latent image by performing image exposure on the surface of the photosensitive drum 1Y on the periphery of the photosensitive drum 1Y, downstream of the charger 20Y in the rotation direction of the photosensitive drum 1Y. 3Y is arranged. Here, as the latent image forming means 3Y, an LED array which can be downsized due to space limitations is used, but the present invention is not limited to this, and other latent image forming means using a laser beam or the like may be used. Of course, there is no problem.
[0100]
Around the photosensitive drum 1Y, a yellow developing unit 4Y is disposed downstream of the latent image forming unit 3Y in the rotation direction of the photosensitive drum 1Y, and is formed on the surface of the photosensitive drum 1Y. The electrostatic latent image is visualized by yellow toner, and a toner image is formed on the surface of the photosensitive drum 1Y.
[0101]
An intermediate transfer belt 15 that primarily transfers a toner image formed on the surface of the photosensitive drum 1Y under the photosensitive drum 1Y in FIG. 1 extends below the four photosensitive drums 1Y, 1M, 1C, and 1K. The intermediate transfer belt 15 is pressed against the surface of the photosensitive drum 1Y by the primary transfer roll 5Y. Further, the intermediate transfer belt 15 is stretched by driving means including three rolls of a driving roll 11, a support roll 12, and a backup roll 13, and is circumferentially moved in the direction of arrow B at a moving speed equal to the process speed of the photosensitive drum 1Y. It is being moved. Then, in addition to the yellow toner image primarily transferred as described above, magenta, cyan, and black toner images are sequentially primary-transferred and stacked on the surface of the intermediate transfer belt 15.
[0102]
Further, around the photosensitive drum 1Y, the toner remaining on the surface of the photosensitive drum 1Y and the re-transferred toner are cleaned downstream of the primary transfer roller 5Y in the rotation direction (the direction of the arrow A) of the photosensitive drum 1Y. A cleaning means 6Y composed of a cleaning blade for cleaning is provided, and the cleaning blade in the cleaning means 6Y is attached to the surface of the photosensitive drum 1Y so as to abut in the counter direction.
[0103]
A secondary transfer roll 14 is pressed against the backup roll 13 that stretches the intermediate transfer belt 15 via the intermediate transfer belt 15 to back up the toner image that has been primarily transferred and stacked on the surface of the intermediate transfer belt 15. It is configured to electrostatically transfer to a nip portion between the roll 13 and the secondary transfer roll 14 on the surface of the transfer receiving body 16 fed from a paper cassette (not shown).
[0104]
Further, on the outer periphery of the intermediate transfer belt 15, a cleaning member 17 for the intermediate transfer belt is disposed at a position substantially corresponding to the surface of the drive roll 11 so as to contact the surface of the intermediate transfer belt 15.
[0105]
In addition, below the drive roll 11 of the intermediate transfer belt 15 in FIG. 1, the toner image multiplex-transferred onto the transfer target 16 is transferred to the surface of the transfer target 16 by heat and pressure to form a permanent image. Fixing device 18 is disposed.
[0106]
Next, an operation of each of the developing units 40Y, 40M, 40C, and 40K configured to form images of each color of yellow, magenta, cyan, and black configured as described above will be described. Since the operations of the developing units 40Y, 40M, 40C, and 40K are the same, the operation of the yellow developing unit 40Y will be described as a representative here.
[0107]
In the yellow developing unit 40Y, the photosensitive drum 1Y is rotating at a predetermined process speed in the direction of arrow A, and a predetermined voltage is applied to the surface of the photosensitive drum 1Y to the charger 20Y by a power supply (not shown). As a result, the battery is negatively charged to a predetermined potential by the discharge generated in the minute gap between the charger 20Y and the photosensitive drum 1Y or the injection of electric charge. Thereafter, image exposure is performed on the surface of the photosensitive drum 1Y by the latent image forming unit 3Y, and an electrostatic latent image corresponding to image information is formed. Subsequently, in the electrostatic latent image formed on the surface of the photoreceptor drum 1Y, the toner negatively charged by the developing device 4Y is reversely developed, and a visible image is formed on the surface of the photoreceptor drum 1Y to form a toner image. You. Thereafter, the toner image on the surface of the photosensitive drum 1Y is primarily transferred to the surface of the intermediate transfer belt 15 by the primary transfer roll 5Y. After the primary transfer, the toner and the like remaining on the surface of the photoreceptor drum 1Y are scraped off by the cleaning blade of the cleaning unit 6Y, and the photoreceptor drum 1Y is prepared for the next image forming step.
[0108]
The above operation is performed in each of the developing units 40Y, 40M, 40C, and 40K, and the toner images visualized on the surfaces of the photosensitive drums 1Y, 1M, 1C, and 1K are multiplexed on the surface of the intermediate transfer belt 15 one after another. It is transcribed. In the full-color mode, the toner images of each color are multiplex-transferred in the order of yellow, magenta, cyan, and black.However, in the same order in the single-color, two-color, and three-color modes, only the necessary color toner images are transferred. It will be singly or multiply transcribed. Thereafter, the toner image transferred singly or multiplely onto the surface of the intermediate transfer belt 15 is secondarily transferred by the secondary transfer roll 14 onto the surface of the transfer receiving body 16 carried from a paper cassette (not shown). At 18, fixing is performed by heating and pressing. The toner remaining on the surface of the intermediate transfer belt 15 after the secondary transfer is cleaned by a cleaning member 17 which is a cleaning blade for the intermediate transfer belt 15.
[0109]
In the image forming apparatus used in the image forming method of the present invention, each constituent member is not particularly limited, other than those defined in the present invention. For example, any known components such as a latent image carrier, an intermediate transfer member (an intermediate transfer belt or an intermediate transfer drum), and a charger can be adopted.
However, it is preferable that the charging means is a roll-charging type charging device in that it can realize environmental preservation and the like by reducing ozone generation at a high level.
[0110]
As the cleaning means 6Y, a blade cleaning type is generally preferably used because of its excellent performance stability, and is also used in the above-described example. It is desired to optimize the physical property control and contact conditions of the blade in order to enable cleaning of a toner having a shape close to a sphere. However, the developer defined in the present invention, particularly the monodisperse spherical silica described above, is desired. By using a developer containing a toner to which an external additive in combination with an abrasive and a lubricant has been added, it is possible to stably clean the residual toner on the surface of the latent image carrier, and to improve the resistance of the latent image carrier. The life due to abrasion can be greatly extended.
[0111]
The image forming method according to the present invention is also the above image forming method, wherein the toner composition contains a binder resin, a colorant, and a release agent, and has a different volume average primary particle size. One or more kinds of inorganic oxide fine powders, and one of them is an inorganic oxide fine powder whose surface is coated with a charge controlling agent, and has a shape factor SF1 (ML ² / A) is a toner composition having a shape of 100 to 140, wherein the cleaning means uses a developing device without rubbing the latent image carrier with a blade, and the residual on the surface of the latent image carrier. It is characterized in that the toner is collected.
[0112]
That is, when the above-described toner composition of the present invention is used, an electrostatic brush can be used as the cleaning means without rubbing the latent image carrier with a blade. The blade cleaning method is generally used because of high performance stability, but by using the toner of the present invention, it becomes possible to collect the residual toner on the surface of the latent image carrier using an electrostatic brush, The wear life (life) of the latent image carrier can be greatly extended.
[0113]
As the electrostatic brush, a carbon fiber, a fibrous substance made of a resin containing a conductive filler such as a metal oxide, or a fibrous substance coated on the surface with the conductive filler can be used. However, the present invention is not limited to these.
[0114]
The image forming method according to the present invention is the image forming method as described above, wherein the toner composition contains a binder resin, a colorant, and a release agent, and has different volume average primary particle diameters. One or more kinds of inorganic oxide fine powders, and one of them is an inorganic oxide fine powder whose surface is coated with a charge controlling agent, and has a shape factor SF1 (ML ² / A) is a toner composition having a shape of 100 to 140, wherein the cleaning means uses a developing device without rubbing the latent image carrier with a blade, and the residual on the surface of the latent image carrier. It is characterized in that the toner is collected.
[0115]
That is, when the toner composition of the present invention described above is used, the residual toner on the surface of the latent image carrier is collected by using a developing device without rubbing the latent image carrier with a blade as the cleaning unit. It is possible to do.
In this way, even when the residual toner is collected again in the developing device, stable development, transfer and fixing performance can be obtained without specific toner being selectively accumulated.
[0116]
As described above, the image forming method of the present invention has been described with reference to the drawings of an example of the image forming apparatus used in the image forming method of the present invention. However, the present invention is not limited to the above. Regarding the element, any change or modification can be made based on known knowledge, and is not limited.
[0117]
The present invention further provides a charging unit for uniformly charging the latent image carrier, a latent image forming unit for exposing the surface of the charged latent image carrier to form an electrostatic latent image, and a toner composition for forming the electrostatic latent image. Developing means for developing a toner image by using a material, an image forming apparatus including a transfer and fixing means for transferring the formed toner image to an intermediate transfer member, and simultaneously transferring the toner image to a recording material and fixing the image; An image forming method for forming, wherein the toner composition contains a binder resin, a colorant, and a release agent, and contains two or more inorganic oxide fine powders having different volume average primary particle diameters. And one of them is a toner composition which is an inorganic oxide fine powder whose surface is coated with a charge controlling agent, wherein the transfer fixing unit develops each color toner on a latent image carrier, Each color is recorded at once after transfer to the intermediate transfer body Transferred to, characterized by simultaneously fixed.
[0118]
That is, when the toner composition of the present invention described above is used, even when an image is formed using an image forming apparatus having the transfer and fixing unit, a high-quality image can be obtained particularly in a full-color image. it can.
[0119]
In the image forming method of the present invention, the intermediate transfer member in the transfer step is to convey to a predetermined toner image transfer fixing position while holding the unfixed toner image, and specifically, the base layer and the surface layer It is preferable to use a two-layer structure having the following structure. As the base layer, a resin film containing a conductive filler such as carbon black or metal oxide can be used to control the resistance to be low. For the surface layer, it is preferable to use a film made of a material having a low surface energy in order to increase the releasability of the toner. It is important that all of the materials are heat-resistant films, and films of PFA (copolymer of tetrafluoroethylene / perfluoroalkylvinyl ether), PTFE (polytetrafluoroethylene), polyimide, silicone, and the like can be used. it can. However, it is not limited to these.
[0120]
In the image forming method of the present invention, the transfer and fixing in the transfer and fixing unit is performed at least by heating, but is preferably performed by heating and pressing. Specifically, for example, a predetermined recording material is overlapped so as to sandwich the toner image on the intermediate transfer body, and heating and pressing are performed with the overlapped intermediate transfer body, toner image, and recording material sandwiched therebetween. It is preferable to use a pair of heating and pressing members. As the heating and pressurizing member, a roll in which a heat-resistant elastic layer such as silicone rubber is formed on the surface of a metal roll of iron, stainless steel, copper, aluminum, or the like, in which a heat source such as a halogen lamp is included can be used. The heating and pressurizing member is not limited to a roll, and may be of any configuration as long as it can uniformly pressurize without causing lifting or displacement between the intermediate transfer member and the recording material. May be. For example, a combination of one heating / pressing roll and one fixing pad, or a set of fixing pads may be used.
[0121]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited thereto. In the description of the toner composition and the carrier, all “parts” mean “parts by mass” unless otherwise specified.
In the production of the toner composition, the carrier, and the electrostatic latent image developer, each measurement was performed by the following methods.
[0122]
<Measurement method for each sample>
-Measurement of coating uniformity of inorganic oxide fine powder-
The sample particles were dispersed in a two-part mixed epoxy liquid, and left standing for one day to solidify. Then, a 100-nm-thick section was prepared with a microtome. The section was placed on a copper mesh surface, set on a high-resolution electron microscope JEM-2010 (manufactured by JEOL Ltd.), photographed at 500,000 times at an applied voltage of 200 kV, and the negative was extended to 3 to 10 times. Printed.
By the printing according to the above procedure, the surface of the particle having a cross section of 10 particles was arbitrarily observed, the surface coating state on the entire surface of the particle was evaluated, and the coverage was determined by the following equation (2).
Coverage = cover length / total surface length of particles × 100 (%) Equation (2)
[0123]
-Specific gravity measurement of external additives-
The specific gravity of the external additive was measured using a Le Chatelier specific gravity bottle in accordance with JIS-K-0061 5-2-1. The operation was performed as follows.
(1) About 250 ml of ethyl alcohol is placed in a Le Chatelier pycnometer, and adjusted so that the meniscus is positioned at the scale.
(2) The pycnometer is immersed in a constant temperature water bath, and when the liquid temperature reaches 20.0 ± 0.2 ° C., the position of the meniscus is accurately read on the scale of the pycnometer (accuracy 0.025 ml).
(3) Approximately 100.000 g of a sample is weighed, and the weight is W.
(4) Place the weighed sample in a pycnometer to remove bubbles.
(5) The pycnometer is immersed in a thermostatic water bath, and when the liquid temperature reaches 20.0 ± 0.2 ° C., the position of the meniscus is accurately read on the scale of the pycnometer (accuracy 0.025 ml).
(6) The specific gravity is calculated by the following equations (3) and (4).
D = W / (L2−L1) Equation (3)
S = D / 0.9982 Expression (4)
In the formula, D is the density of the sample (20 ° C.) (g / cm ³ ), S is the specific gravity of the sample (20 ° C.), W is the apparent mass of the sample (g), L1 is the meniscus reading (20 ° C.) (ml) before putting the sample into the pycnometer, L2 is the sample. The meniscus reading (20 ° C) (ml) after being placed in the pycnometer, 0.9982 is the density of water at 20 ° C (g / cm) ³ ).
[0124]
-Measurement of primary particle size and standard deviation of external additives-
A laser diffraction / scattering particle size distribution analyzer (HORIBA LA-910) was used.
[0125]
−sphericity−
The true sphericity of Wadell was adopted as the sphericity, and the sphericity was determined by the following equation.
[0126]
(Equation 1)

[0127]
In the above formula, the molecule (1) was obtained by calculation from the average particle size. In the denominator (2), a BET specific surface area was used instead of a Shimadzu powder specific surface area measuring device SS-100.
[0128]
−Resistance measurement−
As shown in FIG. 2, when the thickness of the measurement sample 53 is H, the thickness of the measurement sample 53 is measured by a dial gauge while being pressed between the lower electrode 54 and the upper electrode 52, and the electric resistance of the measurement sample 53 is set to a high voltage. It was measured with a resistance meter 55. Specifically, 4.9 × 10 ⁷ A measurement disc was prepared by applying a pressure of Pa. Next, the surface of the disk was cleaned with a brush, sandwiched between the upper electrode 52 and the lower electrode 54 in the cell, and the thickness was measured with a dial gauge. Next, a voltage was applied and the current value was read to determine the volume resistivity.
The carrier sample was filled in a lower electrode 54 of 100φ, the upper electrode 52 was set, a load of 3.43 kg was applied from above, and the thickness was measured with a dial gauge. Next, a voltage was applied and the current value was read to determine the volume resistivity.
[0129]
-Toner shape SF1 (ML ² / A)-
In the present invention, the toner has an average shape index SF1 (ML ² / A) means a value calculated by the following equation (5). ² / A = 100.
ML ² / A = (maximum length) ² × π × 100 / (area × 4) Equation (5)
As a specific method for obtaining the average shape index, a toner image is taken from an optical microscope into an image analyzer (LUZEX III, manufactured by Nireco Co., Ltd.), and the equivalent circle diameter is measured. Of the above formula for the particles of ² Find the value of / A.
[0130]
−Charge amount measurement−
The charge amount at high temperature and high humidity and low temperature and low humidity is as follows. Both the toner assembly and the carrier are allowed to stand for 24 hours in each of high temperature and high humidity (30 ° C., 90% RH) and low temperature and low humidity (5 ° C., 10% RH) Then, the toner composition and the carrier are collected in a glass bottle with a lid so that the toner concentration becomes 5% by mass, and turbuler stirring is performed in each atmosphere, and the stirred developer is heated at 25 ° C. and 55% RH. It measured with TB200 by Toshiba under conditions.
The charge amount in the evaluation test of the actual machine was measured using a TB200 manufactured by Toshiba Corporation under the conditions of 25 ° C. and 55% RH in the same manner as described above, by collecting the developer on the mag sleeve in the developing device.
[0131]
-Image area density (Solid Area Density)-
The image density was measured using X-Rite404A (X-Rite).
[0132]
<Preparation of external additives>
-Preparation of charge control agent-coated inorganic oxide fine powder (A)-
3000 parts by mass of silicon oxide fine powder RX200 (hydrophobic, particle shape: amorphous, volume average primary particle size: 12 nm, manufactured by Nippon Aerosil Co., Ltd.) was used as an edge runner “MPUV-2 type” (product name, Matsumoto Foundry Co., Ltd.) ), And 50% by mass of methyltriethoxysilane (trade name: TSL8123: manufactured by Toshiba Silicone Co., Ltd.) is mixed and diluted with 200 parts by mass of ethanol. While adding to the above silicon oxide fine powder, mixing and stirring were performed.
[0133]
Next, 200 parts by mass of benzyltriethylammonium salt of 1-naphthol-4-sulfuric acid was added over 10 minutes while operating the edge runner, and the mixture was stirred. The surface of the methyltriethoxysilane coating was coated with 1-naphthol-sulfuric acid. After attaching the benzyltriethylammonium salt of 4-sulfuric acid, a heat treatment was performed at 105 ° C. for 60 minutes using drying to obtain a charge control agent-coated inorganic oxide fine powder (A).
The volume average primary particle size of the fine powder was 15 nm, and as a result of observing the coating state, the coating thickness was in the range of 1.0 to 2.0 nm, and 100% of the surface of the fine powder was coated.
[0134]
-Preparation of charge control agent-coated inorganic oxide fine powder (B)-
3000 parts by mass of silicon oxide fine powder R812 (hydrophobic, particle shape: amorphous, volume average primary particle size 8 nm, manufactured by Nippon Aerosil Co., Ltd.) was used as an edge runner “MPUV-2 type” (product name, Matsumoto Foundry Co., Ltd.) ), And 50% by mass of methyltriethoxysilane (trade name: TSL8123: manufactured by Toshiba Silicone Co., Ltd.) is mixed and diluted with 200 parts by mass of ethanol. While adding to the above silicon oxide fine powder, mixing and stirring were performed.
[0135]
Next, 100 parts by mass of triphenylmethane-based dye was added over 10 minutes while operating the edge runner, and the mixture was stirred. After the triphenylmethane-based dye was adhered to the surface of the methyltriethoxysilane coating, Heat treatment was performed at 105 ° C. for 60 minutes using drying to obtain a charge control agent-coated inorganic oxide fine powder (B).
The volume average primary particle size of the fine powder was 10 nm, and as a result of observing the coating state, the coating thickness was in the range of 0.5 to 1.5 nm, and 100% of the surface of the fine powder was coated.
[0136]
-Preparation of charge control agent-coated inorganic oxide fine powder (C)-
1500 parts by mass of titanium oxide fine powder MT-150A (particle shape: rice grain, volume average primary particle size 20 nm) is put into an edge runner “MPUV-2 type” (product name, manufactured by Matsumoto Cast Iron Works). The methyltriethoxysilane solution obtained by mixing and diluting 50 parts by mass of methyltriethoxysilane (trade name: TSL8123: manufactured by Toshiba Silicone Co., Ltd.) with 200 parts by mass of ethanol was mixed with the above titanium oxide fine powder while operating an edge runner. It was added to the powder and mixed and stirred.
[0137]
Next, 150 parts by mass of the zinc salicylate derivative was added over 10 minutes while operating the edge runner, and the mixture was stirred. The zinc salicylate derivative was attached to the surface of the methyltriethoxysilane coating, and then dried. Heat treatment was performed at 105 ° C. for 60 minutes to obtain a charge control agent-coated inorganic oxide fine powder (C).
The volume average primary particle diameter of the fine powder was 13 nm, and as a result of observing the coating state, the coating thickness was in the range of 0.5 to 2.0 nm, and 100% of the surface of the fine powder was coated.
[0138]
-Preparation of monodispersed spherical silica (A)-
The silica sol obtained by the sol-gel method is subjected to HMDS treatment, and dried and pulverized to form a spherical single particle having a specific gravity of 1.50, a sphericity of 0.70, and a volume average primary particle diameter D50 of 100 nm (standard deviation: 40 nm). Dispersed silica was obtained.
[0139]
-Preparation of monodispersed spherical silica (B)-
The silica sol obtained by the sol-gel method is subjected to HMDS treatment, and dried and pulverized to obtain a spherical monodisperse having a specific gravity of 1.30, a sphericity of 0.70, and a volume average primary particle size D50 of 120 nm (standard deviation: 40 nm). Silica was obtained.
[0140]
<Production of colored particles A>
・ Styrene-n-butyl acrylate resin (Tg: 58 ° C., Mn: 4000, Mw: 25000): 100 parts
・ Carbon black (Mogal L, manufactured by Cabot): 3 parts
[0141]
The mixture was kneaded with an extruder, pulverized by a jet mill, and then dispersed by an air classifier to have a D50 of 5.0 μm and a ML of 50 μm. ² / A was 148.8.
[0142]
<Production of colored particles B>
-Preparation of resin dispersion (1)-
・ Styrene: 370 parts by mass
-N-butyl acrylate: 30 parts by mass
・ Acrylic acid: 8 parts by mass
・ Dodecanethiol: 24 parts by mass
・ Carbon tetrabromide: 4 parts by mass
[0143]
6 parts by mass of a nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.) and an anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) ) 10 parts by mass of a solution obtained by dissolving 10 parts by mass in 550 parts by mass of ion-exchanged water were emulsified and dispersed in a flask, and while slowly mixing for 10 minutes, 50 parts by mass of ion-exchanged water in which 4 parts by mass of ammonium persulfate was dissolved was added. After purging with nitrogen, while stirring the inside of the flask, the content was heated in an oil bath until the content reached 70 ° C., and emulsion polymerization was continued for 5 hours.
As a result, a resin dispersion (1) in which resin particles having an average particle size of 155 nm, a Tg of 59 ° C., and a weight average molecular weight Mw of 12,000 were dispersed was obtained.
[0144]
-Preparation of resin dispersion (2)-
・ Styrene: 280 parts by mass
-N-butyl acrylate: 120 parts by mass
・ Acrylic acid: 8 parts by mass
[0145]
6 parts by mass of a nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.) and an anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) A) 12 parts by mass of a solution prepared by dissolving 12 parts by mass in 550 parts by mass of ion-exchanged water, emulsified and dispersed in a flask, and slowly mixed for 10 minutes; 50 parts by mass of ion-exchanged water in which 3 parts by mass of ammonium persulfate was dissolved; After purging with nitrogen, while stirring the inside of the flask, the content was heated in an oil bath until the content reached 70 ° C., and emulsion polymerization was continued for 5 hours.
As a result, a resin dispersion (2) in which resin particles having an average particle size of 105 nm, a Tg of 53 ° C., and a weight average molecular weight Mw of 550,000 were dispersed was obtained.
[0146]
-Preparation of colored dispersion liquid (1)-
・ Carbon black (Mogal L: manufactured by Cabot): 50 parts by mass
-Nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.): 5 parts by mass
・ Ion exchange water: 200 parts by mass
[0147]
The above components are mixed, dissolved, and dispersed for 10 minutes using a homogenizer (Ultra Turrax T50: manufactured by IKA), and a color dispersant in which colorant (carbon black) particles having an average particle size of 250 nm are dispersed. (1) was obtained.
[0148]
-Preparation of colored dispersion liquid (2)-
Cyan pigment (Pigment Blue 15: 3): 70 parts by mass
-Nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.): 5 parts by mass
・ Ion exchange water: 200 parts by mass
[0149]
The above components are mixed, dissolved and dispersed for 10 minutes using a homogenizer (Ultra Turrax T50: manufactured by IKA), and a color dispersant in which colorant (Cyan pigment) particles having an average particle size of 250 nm are dispersed. (2) was obtained.
[0150]
-Preparation of colored dispersion (3)-
・ Magenta pigment (Pigment Red122): 70 parts by mass
-Nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.): 5 parts by mass
・ Ion exchange water: 200 parts by mass
[0151]
The above components are mixed, dissolved and dispersed for 10 minutes using a homogenizer (Ultra Turrax T50: manufactured by IKA), and a color dispersant in which colorant (Magenta pigment) particles having an average particle size of 250 nm are dispersed. (2) was obtained.
[0152]
-Preparation of colored dispersion liquid (4)-
-Yellow pigment (Pigment-Yellow 180): 100 parts by mass
-Nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.): 5 parts by mass
・ Ion exchange water: 200 parts by mass
[0153]
The above components are mixed, dissolved and dispersed using a homogenizer (Ultra Turrax T50: manufactured by IKA) for 10 minutes, and a color dispersant in which colorant (Yellow pigment) particles having an average particle size of 250 nm are dispersed. (4) was obtained.
[0154]
-Preparation of release agent dispersion-
-Paraffin wax (HNP0190: manufactured by Nippon Seiro Co., Ltd., melting point: 85 ° C): 50 parts by mass
-Cationic surfactant: (Sanisol B50: manufactured by Kao Corporation): 5 parts by mass
[0155]
The above components were dispersed in a round stainless steel flask using a homogenizer (Ultra Turrax T50: manufactured by IKA) for 10 minutes, and then dispersed using a pressure discharge type homogenizer. A release agent dispersion liquid (1) in which the mold particles were dispersed was obtained.
[0156]
-Preparation of aggregated particles-
-Resin dispersion liquid (1): 120 parts by mass
-Resin dispersion liquid (2): 80 parts by mass
・ Colorant dispersion: 200 parts by mass
-Release dispersion liquid (1): 40 parts by mass
-Cationic surfactant (Sanisol B50: manufactured by Kao Corporation): 1.5 parts by mass
[0157]
The above components were mixed and dispersed in a round stainless steel flask using a homogenizer (Ultra Turrax T50: manufactured by IKA), and then heated to 50 ° C. while stirring the inside of the flask in a heating oil bath. . After holding at 45 ° C. for 20 minutes, it was confirmed by an optical microscope that aggregated particles having a volume average particle diameter D50 of about 4.3 μm were formed. Further, 60 parts by mass of the resin dispersion (1) was slowly added to the above dispersion as a resin-containing fine particle dispersion. Then, the temperature of the heating oil bath was raised to 50 ° C. and maintained for 30 minutes. Observation with an optical microscope confirmed that adhered particles having a volume average particle diameter D50 of about 4.5 μm were formed.
[0158]
-Preparation of colored particles B-
After adding 3 parts by mass of an anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) to the above particle dispersion, the inside of the stainless steel flask is closed, and the mixture is stirred with a magnetic seal for 105 minutes. C. and held for 4 hours.
After cooling, the reaction product was filtered, sufficiently washed with ion-exchanged water, and dried to obtain colored particles for developing an electrostatic image.
[0159]
-Preparation of colored particles KuroB-
Using the colorant dispersion liquid (1), ² A Kuro toner having an A / A of 128.5 and a particle size D50 of 5.8 μm was obtained.
[0160]
-Preparation of colored particles CyanB-
ML using the colorant dispersion liquid (2) by the above method ² A cyan toner having an A / A of 130 and a particle size D50 of 5.6 μm was obtained.
[0161]
-Preparation of colored particles MagentaB-
ML using the colorant dispersion liquid (3) by the above method ² Magenta toner having an A / A of 132.5 and a particle size D50 of 5.5 μm was obtained.
[0162]
-Production of colored particles YellowB-
ML using the colorant dispersion liquid (4) by the above method ² A yellow toner having an A / A of 127 and a particle size D50 of 5.9 μm was obtained.
[0163]
<Manufacture of carrier>
・ Ferrite particles (volume average particle size: 50 μm): 100 parts
・ Toluene: 14 parts
・ Styrene-methacrylate copolymer (component ratio: 90/10): 2 parts
・ Carbon black (R330: manufactured by Cabot): 0.2 parts
[0164]
First, the above-mentioned components excluding the ferrite particles were stirred with a stirrer for 10 minutes to prepare a dispersed coating solution. Next, the coating solution and the ferrite particles were placed in a vacuum degassing type kneader, and were placed at 60 ° C. for 30 minutes. After stirring, the carrier was degassed under reduced pressure while further heating, and dried to obtain a carrier. This carrier has a volume resistivity of 10 at an applied electric field of 1000 V / cm. ¹¹ Ωcm.
[0165]
(Example 1)
100 parts of each of the Kuro, Cyan, Magenta, and Yellow toners of the colored particles B, 1 part of a charge control agent-coated inorganic oxide fine powder (A), and a hydrophobic titanium oxide (TAF-500S) having a volume average primary particle diameter of 50 nm. (Trade name, manufactured by Fuji Titanium Co., Ltd.) and blended at a peripheral speed of 32 m / s for 10 minutes using a Henschel mixer. Then, coarse particles were removed using a sieve having a mesh of 45 μm to obtain a toner.
100 parts of the carrier and 5 parts of the toner were stirred with a V-blender at 40 rpm for 20 minutes, and sieved with a sieve having a mesh of 177 μm to obtain a developer.
[0166]
The above-mentioned developer was applied to a modified copy machine Docu Center Color 500 manufactured by Fuji Xerox Co., Ltd. having a tandem system, and left overnight at high temperature and high humidity (28 ° C., 80 RH%) and low temperature and low humidity (10 ° C., 15 RH%). Thereafter, the developer was idled under each environment for 30 minutes to evaluate the chargeability of the developer. This was also performed on the developer after 20,000 copies.
[0167]
The chargeability evaluation method was measured by a blow-off method. In the blow-off method, 0.5 g of a sample is placed in a metal gauge having a capacity of 30 ml in which a mesh having a mesh size of 18 μm is provided on the upper and lower portions. ⁵ Blow-off was performed for 30 seconds in a nitrogen gas of Pa, and the generated charge was measured with an electrometer (manufactured by Keithley Co., Ltd., 6517A), and calculated by the following equation (6).
Charge amount = Measured charge value / [(Gauge weight before blow-off) − (Gauge weight after blow-off)] Equation (6)
[0168]
The chargeability evaluation was performed according to the following criteria.
-Electrification evaluation criteria-
：: good
△: Some environmental dependence was observed
×: Bad
Table 1 shows the above results.
[0169]
Also, after leaving the developer at high temperature and high humidity (28 ° C., 80 RH%) and low temperature and low humidity (10 ° C., 15 RH%) each day and night, it was applied to a DocuCenter Color 400CP remodeling machine manufactured by Fuji Xerox of tandem system. The image quality evaluation and the chargeability evaluation of the 50,000 sheets of the first sample and the 50,000 sheets of the sample were performed under the environment described above.
[0170]
The image quality evaluation was performed according to the following criteria.
-Image quality evaluation criteria-
◎: Very good
：: good
△: Somewhat bad
×: Bad
Table 2 shows the above results.
[0171]
(Example 2)
To 100 parts of the colored particles BKuro, 1 part of a charge control agent-coated inorganic oxide fine powder (B) and 1.4 parts of hydrophobic titanium oxide (TAF-500S, manufactured by Fuji Titanium Co., Ltd.) having a volume average primary particle size of 50 nm were added. After blending at a peripheral speed of 32 m / s for 10 minutes using a Henschel mixer, coarse particles were removed using a sieve of a 45 μm mesh to obtain a toner.
100 parts of the carrier and 5 parts of the toner were stirred with a V-blender at 40 rpm for 20 minutes, and sieved with a sieve having a mesh of 177 μm to obtain a developer.
[0172]
The same evaluation as in Example 1 was performed for the developer. The results are shown in Tables 1 and 2.
[0173]
(Example 3)
To 100 parts of the colored particles BKuro, 0.7 part of a charge control agent-coated inorganic oxide fine powder (C) and 1.5 parts of hydrophobic silica (RX50, manufactured by Nippon Aerosil Co., Ltd.) having a volume average primary particle size of 40 nm were added. After blending for 10 minutes at a peripheral speed of 32 m / s using a Henschel mixer, coarse particles were removed using a sieve having a mesh of 45 μm to obtain a toner.
100 parts of the carrier and 5 parts of the toner were stirred with a V-blender at 40 rpm for 20 minutes, and sieved with a sieve having a mesh of 177 μm to obtain a developer.
[0174]
The same evaluation as in Example 1 was performed for the developer. The results are shown in Tables 1 and 2.
[0175]
(Example 4)
1.3 parts of the charge control agent-coated inorganic oxide fine powder (A) and 1.2 parts of hydrophobic titanium oxide (TAF-500S, manufactured by Fuji Titanium Co., Ltd.) having a volume average primary particle diameter of 50 nm were added to 100 parts of the colored particles AKuro. In addition, blending was performed for 10 minutes at a peripheral speed of 32 m / s using a Henschel mixer, and then coarse particles were removed using a sieve having a mesh of 45 μm to obtain a toner.
100 parts of the carrier and 5 parts of the toner were stirred with a V-blender at 40 rpm for 20 minutes, and sieved with a sieve having a mesh of 177 μm to obtain a developer.
[0176]
The same evaluation as in Example 1 was performed for the developer. The results are shown in Tables 1 and 2.
[0177]
(Example 5)
To 100 parts of the colored particles BKuro, 2 parts of monodispersed spherical silica (A) was added, and the mixture was blended at a peripheral speed of 32 m / s for 10 minutes using a Henschel mixer. Then, the charge control agent-coated inorganic oxide fine powder (A) 1 Parts, 1.4 parts of hydrophobic titanium oxide (TAF-500S, manufactured by Fuji Titanium Co., Ltd.) having a volume average primary particle size of 50 nm was added, and the mixture was blended at a peripheral speed of 20 m / s for 5 minutes, using a 45 μm mesh sieve. Coarse particles were removed to obtain a toner.
100 parts of the carrier and 5 parts of the toner were stirred with a V-blender at 40 rpm for 20 minutes, and sieved with a sieve having a mesh of 177 μm to obtain a developer.
[0178]
The same evaluation as in Example 1 was performed for the developer. The results are shown in Tables 1 and 2.
[0179]
(Example 6)
To 100 parts of the colored particles BKuro, 1.5 parts of monodispersed spherical silica (B) was added, and the mixture was blended at a peripheral speed of 32 m / s for 10 minutes using a Henschel mixer. Then, the charge control agent-coated inorganic oxide fine powder (A ) 1 part, 1.4 parts of hydrophobic titanium oxide (TAF-500S, manufactured by Fuji Titanium Co., Ltd.) having a volume average primary particle size of 50 nm, blending is performed at a peripheral speed of 20 m / s for 5 minutes, and using a 45 μm mesh sieve. Coarse particles were removed to obtain a toner.
100 parts of the carrier and 5 parts of the toner were stirred with a V-blender at 40 rpm for 20 minutes, and sieved with a sieve having a mesh of 177 μm to obtain a developer.
[0180]
The same evaluation as in Example 1 was performed for the developer. The results are shown in Tables 1 and 2.
[0181]
(Example 7)
100 parts of the colored particles BKuro, 2 parts of monodispersed spherical silica (A), 1 part of a charge control agent-coated inorganic oxide fine powder (A), and a hydrophobic titanium oxide (TAF-500S, Fuji Titanium) having a volume average primary particle diameter of 50 nm. After mixing for 10 minutes at a peripheral speed of 32 m / s using a Henschel mixer, coarse particles were removed using a sieve having a mesh of 45 μm to obtain a toner.
A developer was obtained by stirring 100 parts of the carrier and 5 parts of the toner at 40 rpm for 20 minutes using a V-blender and sieving through a sieve having a network of 177 μm.
[0182]
The same evaluation as in Example 1 was performed for the developer. The results are shown in Tables 1 and 2.
[0183]
(Comparative Example 1)
0.7 parts of fine powder obtained by treating 10% decyltrimethoxysilane with 10% of silicon oxide fine powder RX200 (hydrophobic, particle shape: amorphous, volume average primary particle size: 12 nm, manufactured by Nippon Aerosil Co., Ltd.) in 100 parts of the colored particles BKuro , 1.2 parts of hydrophobic titanium oxide (TAF-500S, manufactured by Fuji Titanium Co., Ltd.) having a volume average primary particle size of 50 nm was added, and the mixture was blended at a peripheral speed of 32 m / s for 10 minutes using a Henschel mixer. The coarse particles were removed using a sieve of No. 1 to obtain a toner.
100 parts of the carrier and 5 parts of the toner were stirred with a V-blender at 40 rpm for 20 minutes, and sieved with a sieve having a mesh of 177 μm to obtain a developer.
[0184]
The same evaluation as in Example 1 was performed for the developer. The results are shown in Tables 1 and 2.
[0185]
(Comparative Example 2)
A developer was obtained in the same manner as in Example 2 except that hydrophobic titanium oxide (TAF-500S, manufactured by Fuji Titanium Co., Ltd.) having an average particle diameter of 50 nm was not used.
[0186]
The same evaluation as in Example 1 was performed for the developer. The results are shown in Tables 1 and 2.
[0187]
(Comparative Example 3)
Example 2 was the same as Example 2 except that 1 part of the charge controlling agent-coated inorganic oxide fine powder (B) was replaced with 1.2 parts of hydrophobic silica (R812, manufactured by Nippon Aerosil Co., Ltd.) having an average particle diameter of 8 nm. A developer was obtained in the same manner.
[0188]
The same evaluation as in Example 1 was performed for the developer. The results are shown in Tables 1 and 2.
[0189]
[Table 1]

[0190]
[Table 2]

[0191]
As is clear from the results in Table 1, the developers of Examples 1 to 7 and Comparative Example 1 had very good chargeability at high temperature and high humidity and low temperature and low humidity, and also had excellent environmental stability. On the other hand, the developer of Comparative Example 2 showed a decrease in the charge amount at high temperature and high humidity, and an increase in charge amount at low temperature and low humidity. The developer of Comparative Example 3 had a small amount of charge at high temperature and high humidity, and had some problems in environmental dependency.
[0192]
As is clear from the results in Table 2, two or more inorganic oxide fine powders of the present invention having different volume average primary particle diameters were added, and one of them was coated on the surface with a charge controlling agent. As shown in the results of Examples 1 to 7, the developer of the toner using the inorganic oxide fine powder has a small difference in charging characteristics between low temperature and low humidity and high temperature and high humidity even when copying is continued for a long time. The charge retention was good, and the image quality was good even after long-term repeated use.
[0193]
On the other hand, the developer of the toner to which two or more kinds of inorganic oxide fine powders having different volume average primary particle diameters were added but not using the inorganic oxide fine powder coated on the surface with the charge controlling agent was used. As shown in the above results, the difference in charging characteristics between low-temperature and low-humidity conditions and high-temperature and high-humidity conditions when copying was continued for a long time was large, and fog occurred during repeated use over a long period of time, resulting in poor charge retention. Further, the developer of the toner to which only the inorganic oxide fine powder having a small particle diameter was added had insufficient transferability from the initial stage as in the result of Comparative Example 3.
[0194]
(Example 8)
Same as Example 5 except that the cleaning blade of the system was removed, an electrostatic brush made of fiber resin having a conductive filler in which carbon black was dispersed was added, and the charging device was changed to a roll charging device. The evaluation of development and transferability was performed.
As a result, a clear image was displayed as in the initial stage, not only at the initial stage, but also after copying 20,000 sheets, and no image problem occurred.
[0195]
(Example 9)
The evaluation was performed in the same manner as in Example 5 except that toner was collected by a developing device using a scorotron charger without using any blade or brush cleaning of the system.
As a result, a clear image was displayed as in the initial stage, not only at the initial stage, but also after copying 20,000 sheets, and no image problem occurred.
[0196]
(Example 10)
In Example 5, the surface material of the transfer belt was changed to PFA, and a device for heating from the back side was provided so that simultaneous transfer and fixing could be performed. In this case, the four color toners of Example 1 were used. When four colors were produced using the composition changed to the external additive composition of No. 5, and examined by combining the colors, a clear high image quality close to the photographic image quality could be obtained.
[0197]
【The invention's effect】
As described above, according to the present invention, the toner has good environmental resistance, and can satisfy toner fluidity, charging property, developing property, transfer property, cleaning property, and fixing property simultaneously and for a long time. An electrostatic image dry type that has no blade cleaning process to promote wear of the image carrier, and recovers transfer residual toner at the same time as development or recovers residual toner on the latent image carrier using an electrostatic brush. A toner and a developer for developing an electrostatic latent image using the toner can be provided. Further, it is possible to provide an image forming method capable of developing, transferring, and fixing corresponding to a demand for high image quality.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing an example of an image forming apparatus used in the present invention.
FIG. 2 is a schematic explanatory view for explaining a method of measuring a volume specific resistance value of a carrier.
[Explanation of symbols]
1Y, 1M, 1C, 1K Photoconductor drum (latent image carrier)
3Y, 3M, 3C, 3K latent image forming means
4Y, 4M, 4C, 4K developing unit
5Y, 5M, 5C, 5K primary transfer roll
6Y, 6M, 6C, 6K cleaning means
11 Drive roll
12 Support roll
13 Backup Roll
14 Secondary transfer roll
15 Intermediate transfer belt
16 Transfer object
17 Cleaning member
18 Fixing unit
20Y, 20M, 20C, 20K Charger (charging means)
40Y, 40M, 40C, 40K developing unit
52 Upper electrode
53 Measurement sample
54 Lower electrode
55 High Voltage Resistance Meter

Claims (9)

An electrostatic image dry toner composition containing a binder resin, a colorant and a release agent, wherein the electrostatic image dry toner composition has two or more inorganic oxide fine particles having different volume average primary particle diameters. An electrostatic image dry toner composition containing a powder, one of which is a fine inorganic oxide powder whose surface is coated with a charge controlling agent. Among the two or more inorganic oxide fine powders having different volume average primary particle sizes, one type has a volume average primary particle size of 5 nm or more and less than 30 nm, and the other has a volume average primary particle size of 30 nm or more and 70 nm. 2. The electrostatic image dry toner composition according to claim 1, wherein the dry toner composition is less than 0.1. 3. The electrostatic charge image according to claim 1, wherein the surface of the inorganic oxide fine powder coated with the charge control agent is coated with the charge control agent to a thickness of 0.5 to 5 nm. Dry toner composition. A developer for developing an electrostatic latent image comprising a carrier and a toner composition, wherein the carrier has, on a core material surface, a resin coating layer in which a conductive material is dispersed and contained in a matrix resin, and the toner composition The product contains a binder resin, a colorant, and a release agent, and further contains two or more kinds of inorganic oxide fine powders having different volume average primary particle sizes, and one of them contains a charge control. A developer for developing an electrostatic latent image, which is a toner composition which is an inorganic oxide fine powder whose surface is coated with an agent. The electrostatic latent image development according to claim 4, wherein the surface of the inorganic oxide fine powder whose surface is coated with the charge control agent is coated with the charge control agent to a thickness of 0.5 to 5 nm. Developer. Charging means for uniformly charging the latent image carrier, latent image forming means for exposing the charged latent image carrier surface to form an electrostatic latent image, and toner using the toner composition for the electrostatic latent image Image formation using an image forming apparatus including a developing unit for developing an image, a transfer unit for transferring the formed toner image to a recording material, and a fixing unit for fixing the transferred toner image to the surface of the recording material The method,
The toner composition contains a binder resin, a colorant, and a release agent, and further contains two or more inorganic oxide fine powders having different volume average primary particle diameters, and one of them. Is a toner composition that is an inorganic oxide fine powder whose surface is coated with a charge controlling agent, wherein the transfer unit develops each color toner on a latent image carrier, transfers the toner to an intermediate transfer body, An image forming method, which is a transfer unit that transfers toner to a recording material at one time. A charging unit for uniformly charging the latent image carrier, a latent image forming unit for exposing the charged latent image carrier to form an electrostatic latent image, and a toner using the toner composition for the electrostatic latent image. Developing means for developing an image, transfer means for transferring the formed toner image to a recording material, cleaning means for removing toner remaining on the surface of the latent image carrier after transfer, and fixing the transferred toner image on the recording material surface An image forming method for forming an image using an image forming apparatus including a fixing unit,
The toner composition contains a binder resin, a colorant, and a release agent, and contains two or more inorganic oxide fine powders having different volume average primary particle diameters, and one of them. Is a toner composition having an inorganic oxide fine powder whose surface is coated with a charge controlling agent, and having a shape having a shape factor SF1 (ML ² / A) of 100 to 140, wherein the cleaning means comprises: An image forming method, wherein an electrostatic brush is used to collect residual toner on the latent image carrier without rubbing the latent image carrier with a blade. Charging means for uniformly charging the latent image carrier, latent image forming means for exposing the charged latent image carrier surface to form an electrostatic latent image, and toner using the toner composition for the electrostatic latent image Developing means for developing the image, transfer means for transferring the formed toner image to the recording material, cleaning means for removing toner remaining on the surface of the latent image carrier after transfer, and fixing the transferred toner image on the recording material surface An image forming method for forming an image using an image forming apparatus including a fixing unit,
The toner composition contains a binder resin, a colorant, and a release agent, and contains two or more inorganic oxide fine powders having different volume average primary particle diameters, and one of them. Is an inorganic oxide fine powder whose surface is coated with a charge controlling agent, and is a toner composition having a shape having a shape factor SF1 (ML ² / A) of 100 to 140, wherein the cleaning means comprises: An image forming method, comprising collecting a residual toner on the surface of a latent image carrier using a developing device without rubbing the latent image carrier with a blade. Charging means for uniformly charging the latent image carrier, latent image forming means for exposing the charged latent image carrier surface to form an electrostatic latent image, and toner using the toner composition for the electrostatic latent image An image forming apparatus that includes an image forming apparatus including a developing unit that develops an image, a transfer fixing unit that transfers the formed toner image to an intermediate transfer member, and simultaneously transfers and fixes the toner image to a recording material; A forming method,
The toner composition contains a binder resin, a colorant, and a release agent, and contains two or more inorganic oxide fine powders having different volume average primary particle diameters, and one of them. Is a toner composition that is an inorganic oxide fine powder coated on the surface with a charge control agent, wherein the transfer and fixing unit develops each color toner on the latent image carrier, and after transferring to the intermediate transfer body, An image forming method, wherein each color is transferred to a recording medium at a time and fixed at the same time.

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