JP4032900B2 - Electrostatic charge image dry toner composition, developer for developing electrostatic latent image, and image forming method - Google Patents

Description

【０１２５】
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。
【０１２６】
−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４．９×１０⁷Ｐａ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。
【０１２７】
−トナー形状ＳＦ１（ＭＬ²／Ａ）−
本発明において、トナーの平均形状指数SF1（ＭＬ²／Ａ）とは、下記式（５）で計算された値を意味し、真球の場合ＭＬ²／Ａ＝１００となる。
ＭＬ²／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ＭＬ²／Ａの値を求める。
【０１２８】
−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。
【０１２９】
−画像濃度（Ｓｏｌｉｄ Ａｒｅａ Ｄｅｎｓｉｔｙ）−
画像濃度は、Ｘ−Ｒｉｔｅ４０４Ａ（Ｘ−Ｒｉｔｅ）を用いて測定した。
【０１３０】
＜外添剤の調製＞
−脂肪酸金属塩被覆無機酸化物微粉末（Ａ）の調製−
酸化チタン微粉末ＭＴ−１５０Ａ（粒子形状：コメ粒状、ＢＥＴ比表面積：６７．５ｍ²／ｇ、体積平均一次粒径２０ｎｍ）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チタン微粉末に添加し、混合攪拌を行った。
【０１３１】
次に、ジンクステアレート粉末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上にジンクステアレートを付着させた後、乾燥を用いて１０５℃で６０分間加熱処理を行い、脂肪酸金属塩被覆無機酸化物微粉末（Ａ）を得た。
当該微粉末の体積平均一次粒径は２３ｎｍ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。
【０１３２】
−脂肪酸金属塩被覆無機酸化物微粉末（Ｂ）の調製−
酸化チタン微粉末ＴＡＦ−１５００（粒子形状：不定形、ＢＥＴ比表面積：５５．０ｍ²／ｇ、体積平均一次粒径２０ｎｍ、富士チタン株式会社製）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チタン微粉末に添加し、混合攪拌を行った。
【０１３３】
次に、カルシウムテアレート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表面にカルシウムテアレートを付着させた後、１０５℃で６０分間加熱処理を行い、脂肪酸金属塩被覆無機酸化物微粉末（Ｂ）を得た。
当該微粉末の体積平均一次粒径は２２ｎｍ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。
【０１３４】
−脂肪酸金属塩被覆無機酸化物微粉末（Ｃ）の調製−
酸化ケイ素微粉末Ａ２００（粒子形状：不定形、ＢＥＴ比表面積：１９０ｍ²／ｇ、体積平均一次粒径１２ｎｍ）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。
【０１３５】
次に、ジンクステアレート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ジンクステアレートを付着させた後、１０５℃で６０分間加熱処理を行い、脂肪酸金属塩被覆無機酸化物微粉末（Ｃ）を得た。
当該微粉末の体積平均一次粒径は１５ｎｍ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。
【０１３６】
−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、体積平均一次粒径が１００ｎｍ（標準偏差：４０ｎｍ）の球形単分散シリカを得た。
【０１３７】
−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、体積平均一次粒径が１２０ｎｍ（標準偏差：４０ｎｍ）の球形単分散シリカを得た。
【０１３８】
＜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
【０１３９】
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、ＭＬ²／Ａが１４８．８の黒トナーＡを得た。
【０１４０】
＜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
【０１４１】
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。
【０１４２】
−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
【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）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。
【０１４４】
−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
【０１４５】
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。
【０１４６】
−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
【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（Ｃｙａｎ顔料）粒子が分散された着色分散剤（２）を得た。
【０１４８】
−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
【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（Ｍａｇｅｎｔａ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（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
【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（Ｙｅｌｌｏｗ顔料）粒子が分散された着色分散剤（４）を得た。
【０１５２】
−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
【０１５３】
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。
【０１５４】
−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
【０１５５】
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。
【０１５６】
−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。
【０１５７】
−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ＭＬ²／Ａが１２８．５、粒径Ｄ50が５．８μｍのＫｕｒｏトナーを得た。
【０１５８】
−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ＭＬ²／Ａが１３０、粒径Ｄ50が５．６μｍのＣｙａｎトナーを得た。
【０１５９】
−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ＭＬ²／Ａが１３２．５、粒径Ｄ50が５．５μｍのＭａｇｅｎｔａトナーを得た。
【０１６０】
−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ＭＬ²／Ａが１２７、粒径Ｄ50が５．９μｍのＹｅｌｌｏｗトナーを得た。
【０１６１】
＜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
【０１６２】
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１０¹¹Ωｃｍであった。
【０１６３】
（参考例１）
前記着色粒子ＢのＫｕｒｏ、Ｃｙａｎ、Ｍａｇｅｎｔａ、Ｙｅｌｌｏｗトナーのそれぞれ１００部に、脂肪酸金属塩被覆無機酸化物微粉末（Ａ）１部、体積平均一次粒径４０ｎｍの疎水性シリカ（ＲＸ５０、日本アエロジル社製）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。
【０１６４】
上記現像剤を用い、タンデムシステムを有するＦｕｊｉ Ｘｅｒｏｘ社製複写機Ｄｏｃｕ Ｃｅｎｔｒｅ Ｃｏｌｏｒ ４００ＣＰ改造機を用いて現像性及び転写性の評価を行った。
現像性の評価はトナー濃度５質量％の現像剤をそれぞれの温度湿度環境下で一晩放置し、２ｃｍ×５ｃｍのパッチを２ヶ所有する画像をコピーし、ハードストップにおける現像量を測定した。すなわち、感光体表面の前記２個所の現像部分をそれぞれテープ上に粘着性を利用し転写して、トナー付着テープ質量を測定し、テープ質量を差し引いた後に平均化することにより現像量を求めた。
【０１６５】
目標値である４．０〜５．０ｇ／ｍ² の範囲である場合を○、範囲外を×として判定を行った。 かぶり評価は、背景部を同様にテープ上に転写し、１ｃｍ²当たりのトナー個数を数え、１００個以下を○とし、１００個から５００個までを△、それより多い場合は×とし判定を行った。
【０１６６】
転写性の評価は、転写工程終了時にハードストップを行い、２ヶ所の中間転写体表面のトナー質量を上記同様テープ上に転写し、トナー付着テープ質量を測定し、テープ質量を差し引いた後に平均化することにより、転写トナー量ａを求め、同様に感光体表面に残ったトナー量ｂを求め、下記式（６）により転写効率を求めた。
転写効率η（％）＝ａ×１００／（ａ＋ｂ） ・・・ 式（６）
【０１６７】
目標値は転写効率η≧９９％であり、これを基準に次の様に判断を行った。
・η≧９９％ ・・・ ○
・９０％≦η＜９９％ ・・・ △
・η＜９０％ ・・・ ×
以上の評価について、初期の結果を表１に、２万枚複写後の結果を表２に示す。
【０１６８】
（参考例２）
上記着色粒子ＢＫｕｒｏ１００部に、脂肪酸金属塩被覆無機酸化物微粉末（Ｂ）１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）１．４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。
【０１６９】
上記現像剤について、参考例１と同様の評価を行った。結果を表１、２に示す。
【０１７０】
（参考例３）
上記着色粒子ＢＫｕｒｏ１００部に、脂肪酸金属塩被覆無機酸化物微粉末（Ｃ）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）１．５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。
【０１７１】
上記現像剤について、参考例１と同様の評価を行った。結果を表１、２に示す。
【０１７２】
（参考例４）
上記着色粒子ＡＫｕｒｏ１００部に、脂肪酸金属塩被覆無機酸化物微粉末（Ａ）１．３部、体積平均一次粒径４０ｎｍの疎水性シリカ（ＲＸ５０、日本アエロジル社製）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。
【０１７３】
上記現像剤について、参考例１と同様の評価を行った。結果を表１、２に示す。
【０１７４】
（参考例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、脂肪酸金属塩被覆無機酸化物微粉末（Ａ）１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）１．４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。
【０１７５】
上記現像剤について、参考例１と同様の評価を行った。結果を表１、２に示す。
【０１７６】
（参考例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、脂肪酸金属塩被覆無機酸化物微粉末（Ａ）１部、体積平均一次粒径４０ｎｍの疎水性シリカ（ＲＸ５０、日本アエロジル社製）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。
【０１７７】
上記現像剤について、参考例１と同様の評価を行った。結果を表１、２に示す。
【０１７８】
（参考例７）
上記着色粒子ＢＫｕｒｏ１００部に単分散球形シリカ（Ａ）２部、脂肪酸金属塩被覆無機酸化物微粉末（Ａ）１部、体積平均一次粒径４０ｎｍの疎水性シリカ（ＲＸ５０、日本アエロジル社製）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。
【０１７９】
上記現像剤について、参考例１と同様の評価を行った。結果を表１、２に示す。
【０１８０】
（比較例１）
上記着色粒子ＢＫｕｒｏ１００部に、酸化チタン微粉末ＭＴ−１５０Ａ（粒子形状：コメ粒状、ＢＥＴ比表面積：６７．５ｍ²／ｇ、体積平均一次粒径２０ｎｍ）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４０ｎｍの疎水性シリカ（ＲＸ５０、日本アエロジル社製）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。
【０１８１】
上記現像剤について、参考例１と同様の評価を行った。結果を表１、２に示す。
【０１８２】
（比較例２）
実施例２において、平均粒子径４０ｎｍの疎水性シリカ（ＲＸ５０、日本アエロジル社製）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。
【０１８３】
上記現像剤について、参考例１と同様の評価を行った。結果を表１、２に示す。
【０１８４】
（比較例３）
実施例２において、脂肪酸金属塩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。
【０１８５】
上記現像剤について、参考例１と同様の評価を行った。結果を表１、２に示す。
【０１８６】
【表１】

【０１８７】
【表２】

【０１８８】
以上のように、本発明の、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、かつそのうちの１種が脂肪酸金属塩で表面を被覆した無機酸化物微粉末を用いたトナー組成物の現像剤は、参考例１〜７の結果のように帯電維持性が良好であり、長期繰り返し使用においても転写性が良好であった。また、各現像剤の評価において、２万枚複写後に感光体を抜き出し、表面観察を行ったところ、傷、汚染は軽微であった。
【０１８９】
一方、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たものの、脂肪酸金属塩で表面を被覆した無機酸化物微粉末を用いないトナー組成物の現像剤は、比較例１の結果のように長期繰り返し使用においてやや転写性が劣り、カブリが発生し帯電維持性が不良であった。２万枚複写後に感光体を抜き出し、表面観察を行ったところ、傷がハッキリと確認できた。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組成物の現像剤は、比較例２、３の結果のように初期から転写性が不十分であった。
【０１９０】
（参考例８）
参考例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参考例５と同様にして評価を行なった。
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。
【０１９１】
（参考例９）
参考例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参考例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。
【０１９２】
（参考例１０）
参考例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、参考例１の４色のトナーを参考例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。
【０１９３】
【発明の効果】
以上説明したように、本発明によれば、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、さらに潜像担持体の傷発生を防止できるとともに、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表面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組成物、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 一次転写ロール
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]
BACKGROUND 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 (photoconductor) 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 material and fixed with a heat roll or the like to obtain an image. On the other hand, the latent image carrier is cleaned to form an electrostatic latent image again. Is.
[0003]
The dry developer used in such electrophotography is a one-component developer that uses a toner in which a colorant or the like is blended in a binder resin, and a two-component developer in which the toner is mixed with a carrier. Broadly divided. Since the latter half of the 1980s, the market for electrophotography has been strongly demanded for miniaturization and high functionality with the key to digitization. Particularly, regarding the image quality of full-color images, high-quality quality close to high-quality printing and silver salt photography is desired.
[0004]
As means for achieving high image quality, digitization processing is indispensable, and as an effect of digitization related to such image quality, it is mentioned that complex 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 compared to the analog technology. In particular, for photographic images, gradation correction and color correction are possible, and this is advantageous compared to analog in terms of gradation characteristics, definition, sharpness, color reproduction, and graininess. However, on the other hand, it is necessary to faithfully create a latent image created by an optical system as an image output, and as a toner, an activity aiming at faithful reproduction is being accelerated as the particle size is increasingly reduced. It is difficult to stably obtain high image quality only by reducing the particle size of toner, and improvement of basic characteristics in development, transfer, and fixing characteristics is more important.
[0005]
In particular, in a color image, three or four color toners are superimposed to form an image. Therefore, if any one of these toners exhibits different characteristics from the initial stage at the development, transfer, and fixing stages, or performance different from that of other colors, the color reproduction deteriorates or the image quality deteriorates such as graininess and color unevenness. Will cause. In order to maintain a stable high-quality image over time 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 a one-component developer using a toner itself in which a colorant is dispersed in a binder resin and a two-component developer in which a carrier is mixed with the toner. In either case, when copying, the electrostatic latent image formed on the photoconductor is developed with these developers, the toner image on the photoconductor surface is transferred, and the toner remaining on the photoconductor surface is cleaned. To do. Therefore, the dry developer needs to satisfy various conditions in the copying process, particularly in the developing process or the cleaning process. In other words, the toner is also used for development in the form of individual particles, not as aggregates, during development, and for this purpose, the toner has sufficient fluidity and fluidity or electrical properties. It is necessary not to change over time or with the environment (temperature, humidity). Further, in the case of the two-component developer, it is necessary to prevent the so-called toner filming phenomenon in which the toner adheres to the carrier surface.
[0007]
Further, in cleaning, it is necessary to have a cleaning property such that residual toner is easily detached from the surface of the photosensitive member and that the photosensitive member is not damaged when used with a cleaning member such as a blade or a web. In order to satisfy these requirements, in a dry developer, a one-component developer or two-component developer in which inorganic fine powder such as silica, organic fine powder such as fatty acid, its metal salt and derivatives thereof, and fluorine resin fine powder are externally added to the toner. Various developers have been proposed to improve fluidity, durability or cleaning properties.
[0008]
However, in the conventionally proposed additives, inorganic compounds such as silica, titania, alumina and the like significantly improve the fluidity, but the surface layer of the photoreceptor is easily dented and scratched by the hard inorganic compound fine powder. There is a problem that toner sticks easily at the portion. In recent years, the use of recycled paper has been increasing for the purpose of resource saving. Generally, recycled paper has a problem of generating a lot of paper dust, and paper dust or the like enters between the photoreceptor and the blade. Induces poor cleaning such as black streaks.
[0009]
In order to solve these problems, a fatty acid metal salt is externally added to the toner as an additive, and a wax is externally added (see, for example, Patent Documents 1 to 3). In any of these, the particle size of the additive is as large as 3 to 20 μm, and it is necessary to add a considerable amount in order to efficiently express the effect. In addition, although effective at the beginning, film formation as a lubricant is not uniform due to filming unique to the additive (lubricant), and there arises a problem that whitening, image blur, and the like occur in an image.
[0010]
In addition, titanium oxide particles treated with fatty acid metal salts, titanium oxide fine particles surface-treated while hydrolyzing fatty acid compounds in water, inorganic compounds surface-treated with fatty acid metal salts, and surface treatment with fatty acid aluminum Thus, hydrophobized fine particle titanium oxide has been proposed (see, for example, Patent Documents 4 to 7). In this way, by using the fatty acid metal salt for the surface treatment, the above-mentioned problem derived from the size of the particle diameter of the fatty acid metal salt itself is avoided to some extent. However, in any case, no mention is made of the uniformity of the surface treatment, and scratches on the surface of the photoreceptor are insufficient.
[0011]
On the other hand, a method has been proposed in which hydrophobic hard fine powder is externally added to the toner and the photoconductor is scraped by the polishing effect of the hard fine powder to prevent toner filming (see, for example, Patent Document 8). However, although this method is effective in suppressing filming, there is a drawback that the surface of the photoconductor is worn and the life of the photoconductor is remarkably reduced. At the same time, there is a disadvantage that the cleaning blade is worn by the hard fine powder and the blade life is remarkably reduced.
[0012]
On the other hand, it has been reported that the toner is particularly agitated in the developing device, and the change in the fine structure of the toner surface easily occurs and the transferability is greatly changed (see, for example, Patent Document 9). On the other hand, in recent years, for the purpose of reducing the size of the apparatus from the viewpoint of space saving, reducing waste toner from the viewpoint of environmental protection, and extending the life of the latent image carrier, the cleaning system is omitted, and after the transfer, A cleaner-less system has been proposed in which toner remaining on the surface of the photosensitive drum is dispersed with a brush that contacts the surface of the photosensitive drum, and the dispersed toner is recovered simultaneously with development by a developing device (see, for example, Patent Document 10). ). Generally, when residual toner is collected simultaneously with development in this way, the collected toner and other toners have different charging characteristics, and the collected toner is not developed and accumulated in the developing device. Therefore, it is necessary to further increase the transfer efficiency and control the amount of collected toner to a minimum.
[0013]
In addition, in order to improve fluidity, chargeability, and transferability, it has been proposed to make the toner shape closer to a sphere (see, for example, Patent Document 11). However, by making the toner spherical, the following problems are likely to occur. 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 interval between the mag roll and the transport amount control plate. However, when a spherical toner is used, the fluidity as a developer is increased, and at the same time, it is hardened and the bulk density is increased. As a result, there is a phenomenon in which developer accumulation occurs at the conveyance regulation region and the conveyance amount becomes unstable. By controlling the surface roughness of the mag roll and reducing the gap between the control plate and the mag roll, it is possible to improve the transport amount, but the packing property 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 fine structure change on the toner surface, in particular, embedding or peeling of the external additive easily occurs, causing a problem that the developability and transferability are greatly changed from the initial one.
[0014]
In order to improve these, it has been reported that a spherical toner and a non-spherical toner can be combined to suppress packing properties and achieve high image quality (see, for example, Patent Document 12). However, these are effective in suppressing packing properties, but non-spherical toner tends to remain as a transfer residue, and high transfer efficiency cannot be achieved. Further, when collecting at the same time as the development, since the non-spherical toner that is the transfer residue is collected, the ratio of the non-spherical toner increases, which causes a problem of further decreasing the transfer efficiency.
[0015]
In order to improve the developability, transferability, and cleaning properties of the spherical toner, there are two types of particles, each having an average particle size of 5 mμ to 20 mμ and an average particle size of 20 mμ to 40 mμ. It is disclosed that inorganic fine particles are used in combination and a specific amount is added (for example, see Patent Document 13). These can initially obtain high developability, transferability, and cleaning properties, but in any case, the force applied to the toner over time cannot be reduced, so that the external additive is buried or peeled off. It occurs easily, and developability and transferability are greatly changed 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 in order to suppress the burying of external additives in the toner against such stress (for example, Patent Documents 14 to 16). reference). However, in any case, since the inorganic fine particles have a large specific gravity, if the external additive particles are enlarged, peeling of the external additive is unavoidable due to the stirring stress in the developing device. Further, since the inorganic fine particles do not have a perfect spherical shape, it is difficult to control the spike of the external additive to be constant when it is adhered to the toner surface. This causes variations in the micro-surface convex shape that functions as a spacer, and stress is selectively applied to the convex portion, so that the burying or peeling of the external additive is further accelerated, which is not sufficient.
[0017]
In addition, a technique for adding organic fine particles of 50 to 200 nm to a toner in order to effectively exhibit a spacer function is disclosed (for example, see Patent Document 17). By using spherical organic fine particles, it is possible to effectively exhibit a spacer function in the initial stage. However, although the organic fine particles are less likely to be buried or peeled off with respect to stress over time, it is difficult to stably express a high spacer function because the organic fine particles themselves are deformed. In addition, it is conceivable to obtain a spacer effect by adding a large amount of organic fine particles to the toner surface or using organic fine particles having a large particle diameter, but in this case, the characteristics of the organic fine particles are greatly reflected. In other words, the influence on the powder properties such as fluidity inhibition and thermal aggregation deterioration of the inorganic fine particle-added toner, and the organic fine particles themselves have a charge imparting ability, and the degree of control freedom from the viewpoint of charging is reduced. This will affect the charging and development.
[0018]
Recently, there is a high demand for colorization, especially on-demand printing, and there is a technique for forming a multicolor image on a transfer belt to cope with high-speed copying, transferring the multicolor image to an image fixing material at a time, and fixing it. Has been reported (for example, see Patent Document 18). If the process of transferring from the photoconductor to the transfer belt is the primary transfer, and the process of transferring from the transfer belt to the recording body is the secondary transfer, the transfer is repeated twice, and a technique for improving the transfer efficiency becomes more and more important. . In particular. In the case of secondary transfer, a multicolor image is transferred at one time, and the recording medium characteristics (for example, in the case of paper, its thickness, surface property, etc.) are variously changed. It is necessary to control the developability and transferability extremely high.
[0019]
In addition, in order to reduce power consumption, space, and obtain a high-quality image, a technique is disclosed in which each color is transferred to an intermediate transfer member and fixed to the recording member at the same time as transfer (see, for example, Patent Documents 19 and 20). ). The important point here is that the transfer belt needs to have both a transfer function and a fixing function. That is, it is necessary to improve transferability in the cooled state in the primary transfer portion and to transfer heat instantaneously in the secondary transfer simultaneous fixing portion, so that a thin layer belt having high heat resistance is used as the belt material. It will be. Here, the functions required of the toner are required to control transfer efficiency to a very high level and to adapt to low-pressure fixing because a strong pressure cannot be applied during fixing. Further, since the belt surface also has a transfer function, it is important to minimize toner contamination during fixing and scratches due to external additives as much as possible.
[0020]
On the other hand, a method has been proposed in which the volume resistivity of the carrier is controlled to faithfully reproduce high image quality, particularly halftone, solid black, and characters (see, for example, Patent Documents 21 to 23). In any of these methods, the resistance is adjusted according to the type and amount of the carrier coating layer. Initially, the target volume resistivity is obtained and high image quality is exhibited, but the carrier coating is caused by stress in the developing device. Layer peeling or the like occurs, and the volume resistivity changes greatly. Therefore, it is difficult to achieve high image quality over a long period of 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 24). Although the change in volume resistivity due to peeling of the coating layer can be suppressed by this method, the external additive or toner component added to the toner adheres to the carrier and changes the volume resistivity of the carrier. It was difficult to develop high image quality over a long period of time, as with any carrier.
[0022]
[Patent Document 1]
JP-A-60-198556
[Patent Document 2]
JP-A-61-231562
[Patent Document 3]
JP-A-61-231563
[Patent Document 4]
JP-A-4-452
[Patent Document 5]
JP-A-5-66607
[Patent Document 6]
JP-A-5-165250
[Patent Document 7]
JP-A-10-161342
[Patent Document 8]
JP-A-2-89064
[Patent Document 9]
Japanese Patent Laid-Open No. 10-312089
[Patent Document 10]
JP-A-5-94113
[Patent Document 11]
Japanese Patent Laid-Open No. 62-184469
[Patent Document 12]
JP-A-6-308759
[Patent Document 13]
Japanese Patent Laid-Open No. 3-100161
[Patent Document 14]
JP-A-7-28276
[Patent Document 15]
JP-A-9-319134
[Patent Document 16]
Japanese Patent Laid-Open No. 10-312089
[Patent Document 17]
Japanese Unexamined Patent Publication No. 6-266152
[Patent Document 18]
JP-A-8-115007
[Patent Document 19]
Japanese Patent Laid-Open No. 10-213977
[Patent Document 20]
JP-A-8-44220
[Patent Document 21]
JP 56-125751 A
[Patent Document 22]
Japanese Patent Laid-Open No. 62-267766
[Patent Document 23]
Japanese Patent Publication No. 7-120086
[Patent Document 24]
JP-A-4-40471
[0023]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances of the prior art.
That is, the object of the present invention is to satisfy the toner fluidity, charging property, developing property, transfer property, cleaning property, fixing property at the same time for a long period of time, and further prevent the latent image carrier from being scratched. An electrostatic charge image that does not have a blade cleaning process that promotes wear of the image carrier, and collects transfer residual toner at the same time as development, or uses an electrostatic brush to collect residual toner on the surface of the latent image carrier It is an object of the present invention to provide a dry toner composition and an electrostatic latent image developer using the dry toner composition. Another object of the present invention is to provide an image forming method capable of developing, transferring, and fixing in response to high image quality requirements.
[0024]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have found that the above object can be achieved by using a specific inorganic oxide fine powder in the toner, thereby completing the present invention. It came to. Ie
<1> An electrostatic charge image dry toner composition containing a binder resin, a colorant and a release agent, wherein the volume average particle diameter D50 is in the range of 2 to 8 μm, and the average shape index SF1 (ML ² / A) is in the range of 100 to 140, and the electrostatic charge image dry toner composition contains two or more inorganic oxide fine powders having different volume average primary particle sizes, and one of them. Is an inorganic oxide fine powder whose surface is coated with a fatty acid metal salt, and has a specific gravity in the range of 1.2 to 1.9, a volume average primary particle size in the range of 80 to 300 nm, and a standard deviation. (Volume average primary particle size × 0.22) An electrostatic charge image dry toner composition comprising the following monodispersed spherical silica.
[0025]
<2> Among two or more types of inorganic oxide fine powders having different volume average primary particle sizes, one type of volume average primary particle size is 5 nm or more and less than 30 nm, and the other one type of volume average primary particle size is The electrostatic image dry toner composition according to <1>, wherein the toner composition has a thickness of 30 nm or more and less than 70 nm.
[0026]
<3> The surface of the inorganic oxide fine powder whose surface is coated with the fatty acid metal salt is coated with the fatty acid metal salt in a thickness of 0.5 to 5 nm. <1> or <2> The electrostatic charge image dry toner composition described.
[0027]
<4> A developer for developing an electrostatic latent image comprising a carrier and a toner composition, the 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, Average particle size D50 is in the range of 2-8 μm, average shape index SF1 (ML ² / A) is in the range of 100 to 140, contains two or more inorganic oxide fine powders having different volume average primary particle diameters, and one of them is an inorganic whose surface is coated with a fatty acid metal salt Oxide fine powder, specific gravity range of 1.2 to 1.9, volume average primary particle size of 80 to 300 nm, standard deviation (Volume average primary particle size × 0.22) A developer for developing an electrostatic latent image, which is a toner composition containing the following monodispersed spherical silica.
[0028]
<5> The electrostatic discharge according to <4>, wherein the surface of the inorganic oxide fine powder whose surface is coated with the fatty acid metal salt is coated with the fatty acid metal salt in 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 forming an electrostatic latent image by exposing the surface of the charged latent image carrier, and forming the electrostatic latent image with a toner composition An image is formed using an image forming apparatus including a developing unit that develops a toner image using the transfer unit, a transfer unit that transfers the formed toner image to a recording material, and a fixing unit that fixes the transferred toner image on the surface of the recording material. In the image forming method, the toner composition contains a binder resin, a colorant, and a release agent, and has a volume average particle diameter D50 in the range of 2 to 8 μm, and an average shape index SF1 (ML ² / A) is in the range of 100 to 140, contains two or more inorganic oxide fine powders having different volume average primary particle diameters, and one of them is an inorganic whose surface is coated with a fatty acid metal salt Oxide fine powder, specific gravity range of 1.2 to 1.9, volume average primary particle size of 80 to 300 nm, standard deviation (Volume average primary particle size × 0.22) A toner composition containing the following monodispersed spherical silica, wherein the transfer means develops each color toner onto a latent image carrier and transfers it to an intermediate transfer body, and then each color toner onto a recording material at once. An image forming method characterized by being a transfer means for transferring.
[0030]
<7> A charging unit that uniformly charges the latent image carrier, a latent image forming unit that forms an electrostatic latent image by exposing the surface of the charged latent image carrier, and the electrostatic latent image is a toner composition. A developing unit that develops the toner image using a transfer unit; a transfer unit that transfers the formed toner image to a recording material; a cleaning unit that removes toner remaining on the surface of the latent image carrier after the transfer; and a transferred toner image on the surface of the recording material An image forming method for forming an image using an image forming apparatus including a fixing unit for fixing to a toner, wherein the toner composition contains a binder resin, a colorant, and a release agent, and has a volume average particle diameter D50. Is in the range of 2-8 μm, average shape index SF1 (ML ² / A) is in the range of 100 to 140, contains two or more inorganic oxide fine powders having different volume average primary particle diameters, and one of them is an inorganic whose surface is coated with a fatty acid metal salt Oxide fine powder, specific gravity range of 1.2 to 1.9, volume average primary particle size of 80 to 300 nm, standard deviation (Volume average primary particle size × 0.22) A toner composition containing the following monodispersed spherical silica, wherein the cleaning means collects residual toner on the surface of the latent image carrier using an electrostatic brush without rubbing the latent image carrier with a blade. This is an image forming method.
[0031]
<8> Charging means for uniformly charging the latent image carrier, latent image forming means for forming an electrostatic latent image by exposing the surface of the charged latent image carrier, and forming the electrostatic latent image with a toner composition A developing unit that develops the toner image using a transfer unit, a transfer unit that transfers the formed toner image to the recording material, a cleaning unit that removes toner remaining on the surface of the latent image carrier after the transfer, and the transferred toner image on the surface of the recording material An image forming method for forming an image using an image forming apparatus including a fixing unit for fixing to a toner, wherein the toner composition contains a binder resin, a colorant, and a release agent, and has a volume average particle diameter D50. Is in the range of 2-8 μm, average shape index SF1 (ML ² / A) is in the range of 100 to 140, contains two or more inorganic oxide fine powders having different volume average primary particle diameters, and one of them is an inorganic whose surface is coated with a fatty acid metal salt Oxide fine powder, specific gravity range of 1.2 to 1.9, volume average primary particle size of 80 to 300 nm, standard deviation (Volume average primary particle size × 0.22) A toner composition containing the following monodispersed spherical silica, wherein the cleaning means collects residual toner on the surface of the latent image carrier using a developing device without rubbing the latent image carrier with a blade. An image forming method.
[0032]
<9> Charging means for uniformly charging the latent image carrier, latent image forming means for forming an electrostatic latent image by exposing the surface of the charged latent image carrier, and forming the electrostatic latent image with a toner composition An image is formed using an image forming apparatus including a developing unit that develops a toner image using the image forming apparatus and a transfer fixing unit that transfers the formed toner image to an intermediate transfer member and transfers the toner image to a recording material and fixes the toner image at the same time. In the image forming method, the toner composition contains a binder resin, a colorant, and a release agent, and has a volume average particle diameter D50 in the range of 2 to 8 μm, an average shape index SF1 (ML ² / A) is in the range of 100 to 140, contains two or more inorganic oxide fine powders having different volume average primary particle diameters, and one of them is an inorganic whose surface is coated with a fatty acid metal salt Oxide fine powder, specific gravity range of 1.2 to 1.9, volume average primary particle size of 80 to 300 nm, standard deviation (Volume average primary particle size × 0.22) A toner composition containing the following monodispersed spherical silica, wherein the transfer fixing means develops each color toner on a latent image carrier and transfers it to an intermediate transfer body, and then each color is used as a recording material at once. An image forming method characterized by transferring and fixing at the same time.
[0033]
Furthermore, in the electrostatic charge image dry toner composition of the present invention, in the inorganic oxide fine powder whose surface is coated with the fatty acid metal salt, the surface of the inorganic oxide fine powder is formed by an organosilane compound or polysiloxane formed from alkoxysilane. It is preferable that the fatty acid metal salt adheres to the coating.
[0036]
In the developer for developing an electrostatic latent image of the present invention, among the two or more kinds of inorganic oxide fine powders having different particle diameters, one kind of volume average primary particle diameter is 5 nm or more and less than 30 nm, and the other kind of one. The volume average primary particle size is desirably 30 nm or more and less than 70 nm.
[0037]
Further, in the inorganic oxide fine powder whose surface is coated with the fatty acid metal salt, the surface of the inorganic oxide fine powder is coated with an organosilane compound or polysiloxane generated from alkoxysilane, and the fatty acid metal salt adheres to the coating. It is preferable.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
<Electrostatic charge image dry toner composition>
The electrostatic charge image dry toner composition of the present invention is an electrostatic charge image dry toner composition containing a binder resin, a colorant and a release agent, and has an average shape in a volume average particle diameter D50 in the range of 2 to 8 μm. Index SF1 (ML ² / A) is in the range of 100 to 140, and the electrostatic charge image dry toner composition contains two or more inorganic oxide fine powders having different volume average primary particle sizes, and one of them. Is an inorganic oxide fine powder whose surface is coated with a fatty acid metal salt, and has a specific gravity in the range of 1.2 to 1.9, a volume average primary particle size in the range of 80 to 300 nm, and a standard deviation. (Volume average primary particle size × 0.22) It contains the following monodispersed spherical silica
[0040]
That is, the electrostatic charge image dry toner of the present invention contains two or more inorganic oxide fine powders as an external additive, and one or more of them are inorganic oxide fine particles whose surface is uniformly coated with a fatty acid metal salt. It must be a powder.
[0041]
Since the fatty acid metal salt is a low surface energy material, not only the fluidity of the surface-treated toner but also the transferability are improved. Further, since the fatty acid metal salt is stretchable, if it is released from the toner and remains on the surface of the photoreceptor after transfer, a cleaning blade that presses against the photoreceptor or a cleaning brush that contacts the photoreceptor at a linear velocity, etc. The mechanical action of the cleaning member causes the fatty acid metal salt to coat the surface of the photoreceptor extremely thinly, and this coating layer reduces the coefficient of friction on the surface of the photoreceptor. By reducing the mechanical pressure of the cleaning member due to the coating layer and the reduction of the friction coefficient, the wear amount and scratches on the surface layer of the photoreceptor can be reduced, and the wear life of the photoreceptor can be improved. Uniform coating of the fatty acid metal salt on the surface of the inorganic oxide fine powder can effectively bring out these effects. It has been found that by adopting such a configuration, the toner fluidity, chargeability, developability, transferability, and fixability can be satisfied simultaneously and for a long time.
[0042]
In the present invention, the external additive having a smaller average particle size has a volume average primary particle size of 5 nm or more and less than 30 nm, and the external additive having a larger average particle size has a volume average primary particle size. A range of 30 nm or more and less than 70 nm is preferable. With the external additive configuration set in this range, the fluidity, chargeability, and transferability of a small particle size toner (average particle size of 8 μm or less) in the initial stage of use can be controlled in a balanced manner.
[0043]
The addition amount of the external additive having a smaller average particle diameter is preferably in the range of 0.3 to 3 parts by mass, and in the range of 0.5 to 1.5 parts by mass with respect to 100 parts by mass of the toner. It is more preferable. If the amount is less than 0.3 part by mass, sufficient fluidity cannot be obtained. The addition 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 in the range of 0.5 to 1.8 parts by mass with respect to 100 parts by mass of the toner. It is more preferable. If it is less than 0.3 parts by mass, sufficient transferability cannot be obtained, and if it is more than 4 parts by mass, deterioration of toner fluidity and deterioration of charge maintaining property cannot be avoided.
[0044]
Development and transfer are affected by the uniform developer transport, current during transfer, etc., but basically the toner particles are pulled away from the binding force of the carrier carrying the toner particles, and the object (latent image carrier) Since it is a process of adhering to a toner or a recording material, it depends on the balance between the electrostatic attraction and the adhesion between the toner particles and the charging member or the adhesion between the toner particles and the latent image carrier. Control of this balance is very difficult, but this process directly affects the image quality, and if development and transfer efficiency is improved, it is expected to improve reliability and save labor by cleaning less, etc. In the above process, 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 balance can be easily achieved.
[0045]
Development / transfer occurs when F (electrostatic attractive force)> 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 reduce the adhesion force. Increasing the transfer electric field tends to cause secondary failure such as generation of reverse polarity toner. Therefore, it is more effective to reduce the adhesive force.
[0046]
Examples of the adhesion force include van der Waals force (non-electrostatic adhesion force) and mirror image force due to the charge of the toner particles. It can be interpreted as being discussed by Van der Waals power. Van der Waals force Fv between spherical particles is represented by the following formula (1),
Fv = H · r ₁ ・ R ₂ / 6 (r ₁ + R ₂ ) ・ A ² ... Formula (1)
(H: constant, r ₁ , R ₂ : Radius of contacting particles, a: distance between particles)
In order to reduce the adhesion force, a fine powder having a very small r compared to the toner particles is interposed 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 for reducing the contact area (number of contact points) is effective, and as a means for stably maintaining the effect, a monodisperse spherical shape having a specific gravity of 1.2 to 1.9 and a volume average primary particle size of 80 to 300 nm in the present invention. It has further been found that it is effective to use silica.
[0047]
The specific gravity can be controlled to 1.9 or less to prevent peeling from the toner, and to 1.2 or more to suppress aggregation and dispersion. Further, since it is monodispersed and spherical, it can be uniformly dispersed on the toner surface and a stable spacer effect can be obtained.
[0048]
The definition of the above monodispersion can be discussed in terms of the standard deviation with respect to the average particle size including aggregates, and the volume average Primary particle size As standard deviation (Volume average primary particle size × 0.22) It is as follows. The definition of the sphere can be discussed in terms of Wadell's sphericity, and the degree of sphericity is 0.6 or more, preferably 0.8 or more. Further, 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 decreases due to light scattering, especially the PE value when taking an image on OHP (light transmission index) And so on. Therefore, it is desirable to use it as a color toner.
[0049]
General fumed silica has a specific gravity of 2.2, and a maximum particle size of 50 nm is a limit from the viewpoint of production. Moreover, although the particle diameter can be increased as an aggregate, uniform dispersion and a stable spacer effect cannot be obtained. On the other hand, as other typical inorganic fine particles, titanium oxide (specific gravity 4.2, refractive index 2.6), alumina (specific gravity 4.0, refractive index 1.8), zinc oxide (specific gravity 5.6, refractive). 2.0), both of which have a high specific gravity, and when the particle diameter is larger than 80 nm that effectively expresses the spacer effect, the toner tends to be peeled off, and the peeled particles are separated from the charge imparting member or the latent member. It becomes easy to shift to an image carrier or the like, causing a decrease in charge or an image quality defect. Also, since the refractive index is high, it is not very suitable for color image formation to use an inorganic substance having a large particle diameter.
[0050]
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, or a Redige mixer.
[0051]
At this time, various additives may be added as necessary. Examples of these additives include other fluidizing agents, cleaning aids such as polystyrene fine particles, polymethyl methacrylate fine particles, and polyvinylidene fluoride fine particles, or transfer aids.
[0052]
The amount of the monodispersed spherical silica having a specific gravity in the range of 1.2 to 1.9 and a volume average primary particle size in the range 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. Is preferable, and the range of 1 to 3 parts by mass is more preferable. If the amount is less than 0.5 parts by mass, sufficient transferability cannot be improved. If the amount is more than 5 parts by mass, toner fluidity and chargeability are inevitably deteriorated.
[0053]
Further, as an external addition method to the toner, two or more kinds of inorganic oxide fine powder and monodispersed spherical silica having a specific gravity in the range of 1.2 to 1.9 and a volume average primary particle size in the range of 80 to 300 nm are simultaneously added and mixed. You can do it.
In addition, when various addition methods were examined, monodispersed spherical silica having a specific gravity in the range of 1.2 to 1.9 and a volume average primary particle size in the range of 80 to 300 nm was first mixed, and other inorganic oxides with a smaller share. By adding a fine powder, the effect of the present invention could be obtained. Moreover, it does not matter even if it goes through a sieving process after external addition mixing.
[0054]
In addition, when spherical toner is used, the packing property is inevitably improved at the conveyance restriction 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 a conductive material in the resin coating layer of the carrier, even if the resin coating layer is peeled off, it is possible to maintain high image quality over the long term without greatly changing the volume resistivity. I found.
[0055]
Furthermore, 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 residual toner on the surface of the latent image carrier using an electrostatic brush. As a result, the wear life of the latent image carrier can be greatly extended.
[0056]
Further, by using the toner of the present invention, a specific toner is not selectively accumulated even when the residual toner is collected again in the developing unit without providing a cleaning system on the surface of the latent image carrier. Stable development, transfer and fixing performance can be obtained.
[0057]
Furthermore, by using the toner of the present invention, each color is developed on a latent image carrier, transferred to a transfer belt, and then fixed at the same time as transferring each color onto a recording body, thereby obtaining a high-quality image. I was able to get it. In addition, it was confirmed at the same time that it does not affect the PE value, which is an index of permeability when taking an image on the OHP surface.
[0058]
Hereafter, the manufacturing method of the inorganic oxide fine powder which coat | covered the surface with the fatty-acid metal salt which concerns on this invention is described.
The inorganic oxide fine powder whose surface is coated with the fatty acid metal salt according to the present invention is prepared by mixing the inorganic oxide fine powder with alkoxysilane or polysiloxane, and the particle 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 the fatty acid metal salt.
[0059]
The inorganic oxide fine powder surface is coated with alkoxysilane or polysiloxane by mechanically mixing and stirring the inorganic oxide fine powder and alkoxysilane or polysiloxane, or spraying the inorganic oxide fine powder with alkoxysilane or polysiloxane. However, mixing and stirring may be performed mechanically. Almost all of the added alkoxysilane or polysiloxane is coated on the particle surface of the inorganic oxide fine powder.
[0060]
In addition, the coated alkoxysilane may be coated as an organosilane compound generated from an alkoxysilane, a part of which is generated through a coating process. Even in this case, the subsequent adhesion of the fatty acid metal salt is not affected.
[0061]
Mixing and stirring of inorganic oxide fine powder and alkoxysilane or polysiloxane, and mixing and stirring of fatty acid metal salt and inorganic oxide fine powder coated with organosilane compound or polysiloxane generated from alkoxysilane on the particle surface As an apparatus for carrying out the process, an apparatus capable of applying a shearing force to the powder layer is preferable, and in particular, an apparatus capable of simultaneously performing shearing, spatula and compression, such as a wheel-type kneader, a ball-type kneader, A blade-type kneader or a roll-type kneader can be used. In carrying out the present invention, a wheel-type kneader can be used more effectively.
[0062]
Specific examples of the wheel type kneader include edge runners (synonymous with “mix muller”, “simpson mill”, “sand mill”), multi-mal, stotz mill, wet pan mill, conner mill, ring muller, and the like. , Preferably an edge runner, multi-mal, Stots mill, wet pan mill, and ring muller, and more preferably an edge runner. Specific examples of the ball kneader include a vibration mill. 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.
[0063]
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 as uniformly as possible with alkoxysilane or polysiloxane. , Preferably in the range of 98-1470 N / cm (10-150 Kg / cm), more preferably in the range of 147-980 N / cm (15-100 Kg / cm), and the treatment time is in the range of 5-120 minutes, preferably May be adjusted appropriately within the range of 10 to 90 minutes. In addition, what is necessary is just to adjust process conditions suitably in the range of 2-2000 rpm, Preferably it is the range of 5-1000 rpm, More preferably, it is the range of 10-800 rpm.
[0064]
The addition amount of alkoxysilane or polysiloxane is preferably in the range of 0.15 to 45 parts by mass with respect to 100 parts by mass of the inorganic oxide fine powder. When the amount is less than 0.15 parts by mass, it is difficult to attach a fatty acid metal salt sufficient to obtain an inorganic oxide fine powder whose surface is uniformly coated with the target fatty acid metal salt. Moreover, since the addition amount of 0.15-45 mass parts can adhere 3-30 mass parts of fatty acid metal salt with respect to 100 mass parts of inorganic oxide fine powder, it exceeds 45 mass parts and is more than necessary. There is no point in adding.
[0065]
Next, the fatty acid metal salt is added to the inorganic oxide fine powder coated with alkoxysilane or polysiloxane, and mixed and stirred to adhere the fatty acid metal salt to the coated alkoxysilane or polysiloxane. If necessary, drying or heat treatment may be further performed.
[0066]
The fatty acid metal salt is preferably added in small portions over time, particularly over about 5 to 60 minutes. The conditions at the time of 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), preferably 98 to 1470 N / cm (10 to 150 Kg / cm) so that the fatty acid metal salt is uniformly attached. cm), more preferably in the range of 147 to 980 N / cm (15 to 100 Kg / cm) and the treatment time in the range of 5 to 120 minutes, preferably in the range of 10 to 90 minutes. Good. In addition, what is necessary is just to adjust process conditions suitably in the range of 2-2000 rpm, Preferably it is the range of 5-1000 rpm, More preferably, it is the range of 10-800 rpm.
[0067]
The addition amount of the fatty acid metal salt is preferably in the range of 3 to 30 parts by mass and more preferably in the range of 3 to 15 parts by mass with respect to 100 parts by mass of the inorganic oxide fine powder. When the addition amount of the fatty acid metal salt is outside the above range, an inorganic oxide fine powder whose surface is uniformly coated with the target fatty acid metal salt cannot be obtained.
[0068]
Furthermore, it is desirable that the surface of the inorganic oxide fine powder whose surface is coated with the fatty acid metal salt is coated with the fatty acid metal salt with a thickness of 0.5 to 5 nm, since the above effects can be stably exhibited. Furthermore, the coverage is preferably 95% or more.
[0069]
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, and more preferably in the range of 30 minutes to 3 hours.
[0070]
The alkoxysilane used for coating the inorganic oxide fine powder is finally coated as an organosilane compound generated from the alkoxysilane through these steps.
[0071]
Examples of the inorganic oxide fine powder used in the present invention include SiO. ₂ TiO ₂ , Al ₂ O _Three , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O _Three , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO / SiO ₂ , K ₂ O. (TiO ₂ ) _n , Al ₂ O _Three ・ 2SiO ₂ , CaCO _Three , MgCO _Three , BaSO _Four , MgSO _Four Etc., and other known ones can be used. Moreover, what performed the hydrophobization process as needed can be used. As the inorganic oxide fine powder whose surface is coated with a fatty acid metal salt, TiO having a relatively low electric resistance is used. ₂ Is preferable because it is most effective.
[0072]
As the fatty acid metal salt for coating the inorganic oxide fine powder, conventionally known fatty acid salts can be used, such as aluminum stearate, calcium laurate, calcium myristate, calcium stearate, zinc clarate, zinc myristate, zinc stearate. Examples thereof include rate and magnesium stearate.
[0073]
The monodispersed spherical silica having a specific gravity in the range of 1.3 to 1.9 and a volume average primary particle size in the range of 80 to 300 nm 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, the specific gravity can be controlled to be lower than that of the vapor phase oxidation method. Further, it is possible to further adjust by controlling the type of hydrophobizing agent in the hydrophobizing step or the amount of treatment. The particle size can be freely controlled by the hydrolysis of the sol-gel method, the weight ratio of alkoxysilane, ammonia, alcohol, water in the condensation polymerization step, the reaction temperature, the stirring rate, and the supply rate.
[0074]
Monodisperse and spherical shapes can also be achieved by making this method. Specifically, tetramethoxysilane is dropped and stirred in the presence of water and alcohol while applying temperature using ammonia water as a catalyst. Next, the silica sol suspension prepared by the reaction is centrifuged to separate it into wet silica gel, alcohol and aqueous ammonia. A solvent is added to wet silica gel to form a silica sol again, and a hydrophobizing agent is added to hydrophobize the silica surface. A general silane compound can be used as the hydrophobizing agent. Next, the target monodispersed silica can be obtained by removing the solvent from the hydrophobized silica sol, drying, and sieve. Further, the silica thus obtained may be treated again.
[0075]
The said silane compound can use what is water-soluble. Such silane compounds include chemical structural formula R _a SiX _4-a (In formula, a is an integer of 0-3, R represents organic groups, such as a hydrogen atom, an alkyl group, and an alkenyl group, X represents hydrolysable groups, such as a chlorine atom, a methoxy group, and an ethoxy group. ), 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 Lan, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercapto Representative examples include propyltrimethoxysilane and γ-chloropropyltrimethoxysilane. The treatment agent in the present invention is particularly preferably dimethyldimethoxysilane, hexamethyldisilazane, methyltrimethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane or the like.
[0076]
The electrostatic charge image dry toner of the present invention comprises a binder resin, a colorant and a release agent, and has a volume average particle diameter D50 in the range of 2 to 8 μm. Is .
Further, the average shape index SF1 of the toner (ML ² / A) 100 to 140 can be used to obtain images with high development, transferability and high image quality. The toner used in the present invention is not particularly limited by the production method as long as it satisfies the above shape index and particle size, and a known method can be used.
[0077]
The shape factor SF1 is obtained by taking an optical microscope image of the magnetic material dispersed core dispersed on the surface of the slide glass into a Luzex image analyzer via a video camera, and obtaining a maximum length (ML) of 100 or more spherical cores. Measure the projected area (A), ML ² It is obtained as an average value of / A.
[0078]
The toner can be produced, for example, by mechanically mixing particles obtained by a kneading and pulverizing method in which a binder resin, a colorant, a release agent, and, if necessary, a charge control agent are kneaded, pulverized, and classified, and a kneading and pulverizing method. A method of changing the shape by impact force or thermal energy, emulsion polymerization of a polymerizable monomer of a binder resin, formation of a dispersion, a colorant, a release agent, and a charge control agent as required Emulsion polymerization aggregation method to obtain toner particles by mixing and aggregating and heat-fusing with dispersion, polymerizable monomer, colorant, release agent for obtaining binder resin, and charge control if necessary Suspension polymerization in which a solution such as an agent is suspended in an aqueous solvent for polymerization, a binder resin, a colorant, a release agent, and if necessary, a solution such as a charge control agent is suspended in an aqueous solvent. A granulating dissolution suspension method or the like can be used. In addition, a manufacturing method may be performed in which the toner obtained by the above method is used as a core, and agglomerated particles are further adhered and heat-fused to give a core-shell structure. Among the above, a wet process toner that can easily obtain a spherical toner is preferably used, and toner particles obtained by an emulsion polymerization aggregation method are preferably used in that toner particles having a sharp distribution can be obtained. By combining with these toner particles, the effect becomes stable.
[0079]
Binder resins 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 acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Homopolymers and copolymers such as vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl butyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropenyl ketone; In particular, typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, and styrene-anhydrous. Mention may be made of maleic acid copolymers, polyethylene, polypropylene and the like. Further examples include polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like.
[0080]
In addition, 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 oxa. 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 can be exemplified as a representative one.
[0081]
Typical examples of the release agent include low molecular weight polyethylene, low molecular weight polypropylene, Fischer tropic wax, montan wax, carnauba wax, rice wax, and candelilla wax.
[0082]
In addition, a charge control agent may be added to the electrostatic charge image dry toner of the present invention as necessary. As the charge control agent, known ones can be used, and azo metal complex compounds, metal complex compounds of salicylic acid, resin type charge control agents containing polar groups, 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 difficult to dissolve 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.
[0083]
<Developer for developing electrostatic latent image>
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, and the carrier is dispersed on the surface of the core material and the conductive material is dispersed in the matrix resin. And the toner composition contains a binder resin, a colorant, and a release agent, and has a volume average particle diameter D50 in the range of 2 to 8 μm, an average shape index SF1 (ML ² / A) is in the range of 100 to 140, contains two or more inorganic oxide fine powders having different volume average primary particle diameters, and one of them is an inorganic whose surface is coated with a fatty acid metal salt Oxide fine powder, specific gravity range of 1.2 to 1.9, volume average primary particle size of 80 to 300 nm, standard deviation (Volume average primary particle size × 0.22) It is a toner composition containing the following monodispersed spherical silica.
[0084]
The toner composition is the aforementioned electrostatic charge 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 is used on the surface of the core material.
Examples of the matrix resin include 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 composed of organosiloxane bonds or modified products thereof, fluororesins, polyesters, polyurethanes, polycarbonates, phenol resins, amino resins, melamine resins, benzoguanamine resins, urea resins, amide resins, epoxy resins, etc. However, it is not limited to these.
[0085]
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. Is not to be done.
The content of the conductive material is preferably in the range of 1 to 50 parts by mass and more preferably in the range of 3 to 20 parts by mass with respect to 100 parts by mass of the matrix resin.
[0086]
Examples of the core material of the carrier include 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 the magnetic brush method, a magnetic material is used. It is preferable that
The average particle diameter of the core material is generally in the range of 10 to 500 μm, preferably in the range of 30 to 100 μm, in terms of volume average particle diameter.
[0087]
As a method for forming a resin coating layer on the surface of the carrier core material, a dipping method in which the carrier core material is immersed in a coating layer forming solution containing a matrix resin, a conductive material and a solvent, or a coating layer forming solution is used as the carrier. 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 floated 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 mentioned.
[0088]
The solvent used in the coating layer forming solution is not particularly limited as long as it dissolves the matrix resin. For example, aromatic hydrocarbons such as toluene and xylene, and ketones such as acetone and methyl ethyl ketone. , Ethers such as tetrahydrofuran and dioxane can be used.
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 develop a stable volume resistivity of the carrier over time. It is preferable.
[0089]
The volume resistivity of the carrier formed as described above corresponds to the upper and lower limits of a normal development contrast potential in order to achieve high image quality. ^Three -10 ^Four In the range of V / cm, 10 ⁶ -10 ¹⁴ A range of Ωcm is preferable. The volume resistivity of the carrier is 10 ⁶ If it is less than Ωcm, the reproducibility of fine lines is poor, and toner fogging on the background due to charge injection tends to occur. The volume resistivity of the carrier is 10 ¹⁴ If it is larger than Ωcm, black solid and halftone reproduction will be worse. In addition, the amount of carrier transferred to the photoconductor increases, and the photoconductor may be easily damaged. Further, as the electrostatic brush, a resin containing a conductive filler such as carbon black or a metal oxide or a fibrous substance coated on the surface can be used, but it is not limited thereto.
[0090]
The developer for developing an electrostatic latent image of the present invention is produced by mixing the toner and the carrier described above. 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, preferably in the range of 3: 100 to 12: 100. It is more preferable.
[0091]
<Image forming method>
The image forming method of the present invention comprises a charging means for uniformly charging a latent image carrier, a latent image forming means for forming an electrostatic latent image by exposing the surface of the charged latent image carrier, and the electrostatic latent image. An image forming apparatus including a developing unit that develops a toner image using a toner composition, a transfer unit that transfers the formed toner image to a recording material, and a fixing unit that fixes the transferred toner image on the surface of the recording material. 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 has a volume average particle diameter D50 in the range of 2 to 8 μm and an average shape index SF1. (ML ² / A) is in the range of 100 to 140, contains two or more inorganic oxide fine powders having different volume average primary particle diameters, and one of them is an inorganic whose surface is coated with a fatty acid metal salt Oxide fine powder, specific gravity range of 1.2 to 1.9, volume average primary particle size of 80 to 300 nm, standard deviation (Volume average primary particle size × 0.22) A toner composition containing the following monodispersed spherical silica, wherein the transfer means develops each color toner onto a latent image carrier and transfers it to an intermediate transfer body, and then each color toner onto a recording material at once. It is a transfer means for transferring.
[0092]
That is, in the image forming method of the present invention, as an image forming apparatus for forming an image, 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. 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 onto a recording material is used. As the toner composition, the above-described toner composition of the present invention is used. In particular, in full-color image formation in the image forming method of the present invention, from the viewpoint of paper versatility and high image quality, each color toner image is temporarily transferred to the surface of an intermediate transfer belt or intermediate transfer drum as an intermediate transfer member. Then, the laminated color toner images are transferred onto the surface of a recording material such as paper at a time.
[0093]
The image forming apparatus includes, in particular, the latent image carrier, charging means for charging the surface of the latent image carrier, and latent image forming means for forming a latent image on the surface of the charged latent image carrier. A tandem type image forming apparatus preferably includes a plurality of developing means for developing the electrostatic latent image using a toner composition and a transfer means for transferring the toner image to an intermediate transfer member.
[0094]
Hereinafter, an example of the image forming apparatus used in the present invention will be described.
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 that respectively form yellow, magenta, cyan, and black images are arranged in parallel at predetermined intervals. (In tandem). Here, the developing units 40Y, 40M, 40C, and 40K are basically configured in the same manner except for the color of the toner in the stored developer. Therefore, the yellow developing unit 40Y will be represented below. explain.
[0095]
The yellow developing unit 40Y includes a photosensitive drum (latent image carrier) 1Y as an image carrier, and the photosensitive drum 1Y has an axis in a direction perpendicular to the paper on which FIG. 1 is drawn. And it is rotationally driven at a predetermined process speed by a driving means (not shown) along the direction of the arrow A shown. As the photoreceptor drum 1Y, for example, an organic photoreceptor having sensitivity in the infrared region is used.
It should be noted that the process speed may be switched automatically or manually according to a predetermined condition. The image forming method of the present invention can realize high-quality image formation and developer maintainability even in such an apparatus in which the process speed is switched in the middle. Here, “automatically according to a predetermined condition” means that, for example, when image information including a high-definition image portion such as a photographic image is input, the normal mode is automatically switched to the low-speed mode in order to obtain a high-quality image. The case where it switches is mentioned.
[0096]
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 source (not shown). The surface of 1Y is charged to a predetermined potential (the same applies to the chargers 20M, 20C, and 20K and the photosensitive drums 1M, 1C, and 1K).
[0097]
Around the photosensitive drum 1Y, latent image forming means for forming an electrostatic latent image by performing image exposure on the surface of the photosensitive drum 1Y on the downstream side 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 that can be miniaturized is used because of space, but the present invention is not limited to this, and other latent image forming means using a laser beam or the like is used. Of course there is no problem.
[0098]
Further, around the photosensitive drum 1Y, a yellow developing device 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 with yellow toner, and a toner image is formed on the surface of the photosensitive drum 1Y.
[0099]
An intermediate transfer belt 15 that primarily transfers a toner image formed on the surface of the photosensitive drum 1Y extends below the four photosensitive drums 1Y, 1M, 1C, and 1K below the photosensitive drum 1Y in FIG. The intermediate transfer belt 15 is pressed against the surface of the photosensitive drum 1Y by the primary transfer roll 5Y. In addition, the intermediate transfer belt 15 is stretched by driving means including three rolls of a drive roll 11, a support roll 12, and a backup roll 13, and moves in the arrow B direction at a moving speed equal to the process speed of the photosensitive drum 1Y. It comes to be moved. In addition to the yellow toner image primarily transferred as described above, magenta, cyan, and black toner images are sequentially primarily transferred and stacked on the surface of the intermediate transfer belt 15.
[0100]
Further, around the photosensitive drum 1Y, the toner remaining on the surface of the photosensitive drum 1Y and the retransferred toner are cleaned downstream of the primary transfer roll 5Y in the rotation direction (arrow A direction) of the photosensitive drum 1Y. A cleaning means 6Y composed of a cleaning blade is disposed, and the cleaning blade in the cleaning means 6Y is attached so as to come into contact with the surface of the photosensitive drum 1Y in the counter direction.
[0101]
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, and the toner image that is primarily transferred and laminated on the surface of the intermediate transfer belt 15 is transferred to the backup roll. 13 and the secondary transfer roll 14 are configured to electrostatically transfer to the surface of the transfer medium 16 fed from a paper cassette (not shown).
[0102]
Further, a cleaning member 17 for the intermediate transfer belt is disposed on the outer periphery of the intermediate transfer belt 15 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.
[0103]
In addition, below the drive roll 11 of the intermediate transfer belt 15 in FIG. 1, the toner image that has been multiplex-transferred on the transfer target 16 is transferred to the transfer target 16 surface by heat and pressure to form a permanent image. A fixing device 18 is disposed for this purpose.
[0104]
Next, the operation of each of the developing units 40Y, 40M, 40C, and 40K that forms an image 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.
[0105]
In the yellow developing unit 40Y, the photosensitive drum 1Y rotates 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 by a power source (not shown) to the charger 20Y. As a result, the charge is negatively charged to a predetermined potential by a discharge generated in a minute gap between the charger 20Y and the photosensitive drum 1Y or by injection of charges. Thereafter, the surface of the photosensitive drum 1Y is subjected to image exposure by the latent image forming unit 3Y, and an electrostatic latent image corresponding to the image information is formed. Subsequently, the electrostatic latent image formed on the surface of the photosensitive drum 1Y is reversely developed with the negatively charged toner by the developing device 4Y, and is visualized on the surface of the photosensitive drum 1Y to form a toner image. The Thereafter, the toner image on the surface of the photosensitive drum 1Y is primarily transferred onto the surface of the intermediate transfer belt 15 by the primary transfer roll 5Y. After the primary transfer, the photosensitive drum 1Y has toner remaining on the surface thereof scraped off and cleaned by a cleaning blade of the cleaning unit 6Y to prepare for the next image forming process.
[0106]
The above operations are performed by 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 sequentially multiplexed on the surface of the intermediate transfer belt 15. It will be transcribed. In full color mode, toner images of each color are transferred in multiple order in the order of yellow, magenta, cyan, and black, but only the toner images of the required colors are also in the same order in the single color, two color, and three color modes. Single or multiple transcription is performed. Thereafter, the toner image that has been individually or multiply transferred onto the surface of the intermediate transfer belt 15 is secondarily transferred onto the surface of the transfer medium 16 conveyed from a paper cassette (not shown) by the secondary transfer roll 14, and then the fixing device. 18 is fixed by being heated and pressurized. The toner remaining on the surface of the intermediate transfer belt 15 after the secondary transfer is cleaned by a cleaning member 17 that is a cleaning blade for the intermediate transfer belt 15.
[0107]
In the image forming apparatus used in the image forming method of the present invention, each component 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 (intermediate transfer belt or intermediate transfer drum), and a charger can be used.
However, the charging means is preferably a roll charging type charger in that environmental conservation due to the reduction of ozone generation can be realized at a high level.
[0108]
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 example. In order to enable near-spherical toner cleaning, it is desirable to optimize the physical property control and contact conditions of the blade, and at the same time, the developer defined in the present invention, particularly the monodispersed spherical silica described above. By using a developer containing a toner to which an external additive combined with an abrasive and a lubricant is added, residual toner on the surface of the latent image carrier can be stably cleaned. The life due to wear can be greatly extended.
[0109]
The image forming method of 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 volume average particle diameter D50 of 2 to 8 μm. Range, average shape index SF1 (ML ² / A) is in the range of 100 to 140, contains two or more inorganic oxide fine powders having different volume average primary particle diameters, and one of them is an inorganic whose surface is coated with a fatty acid metal salt Oxide fine powder, specific gravity range of 1.2 to 1.9, volume average primary particle size of 80 to 300 nm, standard deviation (Volume average primary particle size × 0.22) A toner composition containing the following monodispersed spherical silica, wherein the cleaning means collects residual toner on the surface of the latent image carrier using a developing device without rubbing the latent image carrier with a blade. Characterized by
[0110]
That is, when the toner composition of the present invention described above 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 its high performance stability, but by using the toner of the present invention, it becomes possible to collect residual toner on the surface of the latent image carrier using an electrostatic brush, The wear life (lifetime) of the latent image carrier can be greatly extended.
[0111]
As the electrostatic brush, a fibrous substance made of a resin containing a conductive filler such as carbon black or a metal oxide, or a fibrous substance coated on the surface with the conductive filler can be used. However, it is not limited to these.
[0112]
The image forming method of the present invention is the above image forming method, wherein the toner composition contains a binder resin, a colorant, and a release agent, and has a volume average particle diameter D50 of 2 to 8 μm. Range, average shape index SF1 (ML ² / A) is in the range of 100 to 140, contains two or more inorganic oxide fine powders having different volume average primary particle diameters, and one of them is an inorganic whose surface is coated with a fatty acid metal salt Oxide fine powder, specific gravity range of 1.2 to 1.9, volume average primary particle size of 80 to 300 nm, standard deviation (Volume average primary particle size × 0.22) A toner composition containing the following monodispersed spherical silica, wherein the cleaning means collects residual toner on the surface of the latent image carrier using a developing device without rubbing the latent image carrier with a blade. It is characterized by.
[0113]
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 as the cleaning means by using a developing device without rubbing the latent image carrier with a blade. It becomes possible to do.
In this way, even when the residual toner is collected again in the developing device, specific toner is not selectively accumulated, and stable development, transfer, and fixing performance can be obtained.
[0114]
The image forming method of the present invention has been described above 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 this as long as the configuration of the present invention is provided. The element can be changed or modified in any manner based on known knowledge, and is not limited.
[0115]
The present invention further includes charging means for uniformly charging the latent image carrier, latent image forming means for forming an electrostatic latent image by exposing the surface of the charged latent image carrier, and forming the electrostatic latent image into a toner composition. An image is formed using an image forming apparatus including a developing unit that develops a toner image using an object and a transfer fixing unit that transfers the formed toner image to an intermediate transfer member and transfers the toner image to a recording material and fixes the toner image at the same time. In the image forming method to be formed, the toner composition contains a binder resin, a colorant, and a release agent, and has a volume average particle diameter D50 in the range of 2 to 8 μm, an average shape index SF1 (ML ² / A) is in the range of 100 to 140, contains two or more inorganic oxide fine powders having different volume average primary particle diameters, and one of them is an inorganic whose surface is coated with a fatty acid metal salt Oxide fine powder, specific gravity range of 1.2 to 1.9, volume average primary particle size of 80 to 300 nm, standard deviation (Volume average primary particle size × 0.22) A toner composition containing the following monodispersed spherical silica, wherein the transfer fixing unit develops each color toner on a latent image carrier and transfers it to an intermediate transfer body, and then each color is used as a recording material at once. It is characterized by transferring and fixing at the same time.
[0116]
That is, when the above-described toner composition of the present invention is used, a high-quality image can be obtained particularly in a full-color image even when image formation is performed using the image forming apparatus having the transfer fixing unit. it can.
[0117]
In the image forming method of the present invention, the intermediate transfer body in the transfer step is transported to a predetermined toner image transfer fixing position while holding an unfixed toner image. Specifically, a base layer, a surface layer, It is preferable to use a two-layer structure comprising: 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 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 any material is a heat-resistant film, and PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer), PTFE (polytetrafluoroethylene), polyimide, silicone film, etc. may be used. it can. However, it is not limited to these.
[0118]
In the image forming method of the present invention, the transfer fixing in the transfer 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 member, and the superimposed intermediate transfer member, toner image, and recording material are sandwiched and heated and pressed. It is preferable to use a pair of heating and pressing members. As the heating and pressing member, a roll in which a heat-resistant elastic layer such as silicone rubber is formed on the surface of a metal roll such as iron, stainless steel, copper, or aluminum, and a heat source such as a halogen lamp included can be used. The heating / pressurizing member is not limited to a roll, and may be of any configuration as long as it can uniformly pressurize without causing floating or displacement between the intermediate transfer member and the recording material. But you can. For example, a combination of one heating and pressing roll and one fixed pad, or a set of fixed pads may be used.
[0119]
【Example】
EXAMPLES 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, “part” means “part by mass” unless otherwise specified.
In the production of the toner composition, carrier, and electrostatic latent image developer, each measurement was performed by the following method.
[0120]
<Measurement method for each sample>
-Measurement of coating uniformity of inorganic oxide fine powder-
The sample particles were dispersed in a two-component mixed epoxy solution and left to stand for one day to solidify. Next, a section having a thickness of 100 nm was prepared with a microtome. Place the slice on the surface of a copper mesh, set it on a high-resolution electron microscope JEM-2010 (manufactured by JEOL Ltd.), take a picture at an applied voltage of 200 kV at a magnification of 500,000, and spread the negative 3 times to 10 times. Printed.
The surface of the particle having a cross section of 10 particles was arbitrarily observed by printing according to the above procedure, the surface covering state on the entire surface of the particle was evaluated, and the coverage was determined by the following formula (2).
Coverage = coating length / particle total surface length × 100 (%) (2)
[0121]
-Specific gravity measurement of external additives-
The specific gravity of the external additive was measured in accordance with JIS-K-0061 5-2-1 using a Le Chatelier specific gravity bottle. The operation was performed as follows.
(1) About 250 ml of ethyl alcohol is put into a Lechatelier specific gravity bottle and adjusted so that the meniscus is at the position of the scale.
(2) The specific gravity bottle 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 with the scale of the specific gravity bottle (accuracy is 0.025 ml).
(3) About 100.000 g of a sample is weighed and its mass is defined as W.
(4) Put the weighed sample in a specific gravity bottle to remove bubbles.
(5) The specific gravity bottle 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 with the scale of the specific gravity bottle (accuracy is 0.025 ml).
(6) The specific gravity is calculated by the following formulas (3) and (4).
D = W / (L2-L1) Formula (3)
S = D / 0.9982 Formula (4)
Where D is the density of the sample (20 ° C) (g / cm ^Three ), 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 placing the sample in the specific gravity bottle, and L2 is the sample Meniscus reading (20 ° C) (ml) after being placed in a density bottle, 0.9982 is the density of water at 20 ° C (g / cm ^Three ).
[0122]
-Measurement of primary particle size and standard deviation of external additives-
A laser diffraction / scattering particle size distribution analyzer (HORIBA LA-910) was used.
[0123]
-Sphericality-
As the sphericity, Wadell's true sphericity was adopted, and the sphericity was obtained from the following equation.
[0124]
[Expression 1]

[0125]
In the above formula, the molecule (1) was obtained from the average particle size by calculation. The denominator (2) was replaced with a BET specific surface area using a Shimadzu powder specific surface area measuring device SS-100 type.
[0126]
-Resistance measurement-
As shown in FIG. 2, the thickness of the measurement sample 53 is set to H. The measurement sample 53 is sandwiched between the lower electrode 54 and the upper electrode 52, and the thickness is measured with a dial gauge while applying pressure from above. The resistance meter 55 was used for measurement. Specifically, a specific titanium oxide sample was 4.9 × 10 4 on a molding machine. ⁷ A measurement disk 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.
Also, a carrier sample was filled in a 100φ lower electrode 54, 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.
[0127]
-Toner shape SF1 (ML ² / A)-
In the present invention, the average shape index SF1 (ML ² / A) means the value calculated by the following formula (5). ² / A = 100.
ML ² / A = (maximum length) ² × π × 100 / (area × 4) (5)
As a specific method for determining the average shape index, a toner image is taken from an optical microscope into an image analyzer (LUZEX III, manufactured by Nireco Corporation), the equivalent circle diameter is measured, and the maximum length and area are individually measured. ML of the above formula for the particles of ² Find the value of / A.
[0128]
-Measurement of charge amount-
The amount of charge at high temperature and high humidity and low temperature and low humidity is such that both toner assembly and carrier are left for 24 hours in high temperature and high humidity (30 ° C, 90% RH) and low temperature and low humidity (5 ° C, 10% RH), respectively. Then, a toner composition and a carrier are collected in a glass bottle with a lid so that the toner concentration becomes 5% by mass, and stirred by a tumbler in each atmosphere. The stirred developer is 25 ° C. and 55% RH. Measurement was performed with a TB200 manufactured by Toshiba under the conditions.
The charge amount in the actual machine evaluation test was measured with a TB200 manufactured by Toshiba under the conditions of 25 ° C. and 55% RH as described above, by collecting the developer on the mag sleeve in the developing device.
[0129]
-Image density (Solid Area Density)-
The image density was measured using X-Rite 404A (X-Rite).
[0130]
<Preparation of external additive>
-Preparation of fatty acid metal salt-coated inorganic oxide fine powder (A)-
Titanium oxide fine powder MT-150A (particle shape: rice granular, BET specific surface area: 67.5 m ² / G, volume average primary particle size 20 nm) 3000 parts by mass are introduced into an edge runner “MPUV-2 type” (product name, manufactured by Matsumoto Foundry Co., Ltd.) and methyltriethoxysilane (trade name: TSL8123: Toshiba) A methyltriethoxysilane solution obtained by mixing and diluting 50 parts by mass with 200 parts by mass of ethanol was added to the titanium oxide fine powder while operating the edge runner, and mixed and stirred.
[0131]
Next, 200 parts by mass of zinc stearate powder was added over 10 minutes while operating the edge runner, mixed and stirred, and zinc stearate was deposited on the methyltriethoxysilane coating, followed by drying. Then, heat treatment was performed at 105 ° C. for 60 minutes to obtain a fatty acid metal salt-coated inorganic oxide fine powder (A).
The volume average primary particle size of the fine powder was 23 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.
[0132]
-Preparation of fatty acid metal salt-coated inorganic oxide fine powder (B)-
Titanium oxide fine powder TAF-1500 (particle shape: irregular, BET specific surface area: 55.0 m ² / G, volume average primary particle size 20 nm, manufactured by Fuji Titanium Co., Ltd. (3000 parts by mass) was introduced into an edge runner “MPUV-2 type” (product name, manufactured by Matsumoto Casting Co., Ltd.), and methyltriethoxysilane ( (Product name: TSL8123: manufactured by Toshiba Silicone Co., Ltd.) Methyltriethoxysilane solution obtained by mixing and diluting 50 parts by mass with 200 parts by mass of ethanol was added to the above titanium oxide fine powder while operating the edge runner, and mixed. Stirring was performed.
[0133]
Next, 100 parts by weight of calcium tearate was added over 10 minutes while operating the edge runner, mixed and stirred to attach calcium tearate to the methyltriethoxysilane-coated surface, and then at 105 ° C. for 60 minutes. Heat treatment was performed to obtain a fatty acid metal salt-coated inorganic oxide fine powder (B).
The volume average primary particle size of the fine powder was 22 nm. 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.
[0134]
-Preparation of fatty acid metal salt-coated inorganic oxide fine powder (C)-
Silicon oxide fine powder A200 (particle shape: amorphous, BET specific surface area: 190 m ² / G, 1500 parts by mass of the volume average primary particle size 12 nm) are introduced into an edge runner “MPUV-2 type” (product name, manufactured by Matsumoto Foundry Co., Ltd.) and methyltriethoxysilane (trade name: TSL8123: Toshiba). A methyltriethoxysilane solution obtained by mixing and diluting 50 parts by mass with 200 parts by mass of ethanol was added to the titanium oxide fine powder while operating the edge runner, and mixed and stirred.
[0135]
Next, 150 parts by mass of zinc stearate was added over 10 minutes while the edge runner was operated, mixed and stirred, and zinc stearate was attached to the surface of the methyltriethoxysilane coating, and then at 60 ° C. at 60 ° C. Heat treatment was performed for a minute to obtain a fatty acid metal salt-coated inorganic oxide fine powder (C).
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 0.5 to 2.0 nm, and 100% of the surface of the fine powder was coated.
[0136]
-Preparation of monodispersed spherical silica (A)-
The silica sol obtained by the sol-gel method is subjected to HMDS treatment, dried and pulverized to have a specific gravity of 1.50, a sphericity Ψ of 0.70, and a volume average primary particle. Diameter A spherical monodispersed silica of 100 nm (standard deviation: 40 nm) was obtained.
[0137]
-Preparation of monodispersed spherical silica (B)-
Silica sol obtained by the sol-gel method is subjected to HMDS treatment, dried and pulverized to have a specific gravity of 1.30, a sphericity Ψ of 0.70, and a volume average primary particle. Diameter A spherical monodispersed silica having a thickness of 120 nm (standard deviation: 40 nm) was obtained.
[0138]
<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
[0139]
The above mixture is kneaded with an extruder, pulverized with a jet mill, and then dispersed with a wind classifier. D50 is 5.0 μm, ML ² A black toner A having / A of 148.8 was obtained.
[0140]
<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
[0141]
6 parts by mass of nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.) and anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were prepared by mixing and dissolving the above components. ) 10 parts by mass dissolved in 550 parts by mass of ion-exchanged water was 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 had been dissolved was added thereto. After carrying out nitrogen substitution, while stirring the inside of the flask, it was heated in an oil bath until the contents 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 diameter of 155 nm, a Tg of 59 ° C., and a mass average molecular weight Mw of 12000 was dispersed was obtained.
[0142]
-Preparation of resin dispersion (2)-
・ Styrene: 280 parts by mass
N-butyl acrylate: 120 parts by mass
-Acrylic acid: 8 parts by mass
[0143]
6 parts by mass of nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.) and anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were prepared by mixing and dissolving the above components. ) 12 parts by mass dissolved in 550 parts by mass of ion-exchanged water was emulsified and dispersed in a flask. While slowly mixing for 10 minutes, 50 parts by mass of ion-exchanged water in which 3 parts by mass of ammonium persulfate was dissolved was added thereto. After carrying out nitrogen substitution, while stirring the inside of the flask, it was heated in an oil bath until the contents 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 diameter of 105 nm, a Tg of 53 ° C., and a mass average molecular weight Mw of 550000 was dispersed was obtained.
[0144]
-Preparation of colored dispersion (1)-
・ Carbon black (Mogal L: 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
[0145]
A colored dispersant in which the above components are mixed, dissolved and dispersed for 10 minutes using a homogenizer (Ultra Turrax T50: manufactured by IKA), and colorant (carbon black) particles having an average particle size of 250 nm are dispersed. (1) was obtained.
[0146]
-Adjustment of colored dispersion (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
[0147]
A coloring dispersant in which the above components are mixed, dissolved, and dispersed for 10 minutes using a homogenizer (Ultra Turrax T50: manufactured by IKA) to disperse colorant (Cyan pigment) particles having an average particle diameter of 250 nm. (2) was obtained.
[0148]
-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
[0149]
A color dispersant in which the above components are mixed, dissolved, and dispersed for 10 minutes using a homogenizer (Ultra Turrax T50: manufactured by IKA) to disperse colorant (Magenta pigment) particles having an average particle diameter of 250 nm. (2) was obtained.
[0150]
-Preparation of colored dispersion (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
[0151]
A coloring dispersant in which the above components are mixed, dissolved and dispersed for 10 minutes using a homogenizer (Ultra Turrax T50: manufactured by IKA), and colorant (Yellow pigment) particles having an average particle size of 250 nm are dispersed. (4) was obtained.
[0152]
-Preparation of release agent dispersion-
Paraffin wax: (HNP0190: Nippon Seiwa Co., Ltd., melting point 85 ° C.): 50 parts by mass
Cationic surfactant: (Sanisol B50: manufactured by Kao Corporation): 5 parts by mass
[0153]
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 with a pressure discharge type homogenizer, and the average particle size was 550 nm. A release agent dispersion liquid (1) in which the mold agent particles were dispersed was obtained.
[0154]
-Preparation of aggregated particles-
-Resin dispersion (1): 120 parts by mass
-Resin dispersion (2): 80 parts by mass
-Colorant dispersion: 200 parts by mass
-Mold release dispersion (1): 40 parts by mass
Cationic surfactant (Sanisol B50: manufactured by Kao Corporation): 1.5 parts by mass
[0155]
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 an oil bath for heating. . After maintaining at 45 ° C. for 20 minutes, it was confirmed with an optical microscope that it was confirmed 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) as a resin-containing fine particle dispersion was gently added to the dispersion. The temperature of the heating oil bath was raised to 50 ° C. and held for 30 minutes. When observed with an optical microscope, it was confirmed that adhered particles having a volume average particle diameter D50 of about 4.5 μm were formed.
[0156]
-Production 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 particle dispersion, the stainless steel flask was sealed and stirred using a magnetic seal. Heat to 0 ° C. and hold for 4 hours.
Then, after cooling, the reaction product was filtered, washed thoroughly with ion-exchanged water, and dried to obtain colored particles for electrostatic image development.
[0157]
-Production of colored particles KuroB-
Using the colorant dispersion (1), ML ² A Kuro toner having a / A of 128.5 and a particle size D50 of 5.8 μm was obtained.
[0158]
-Production of colored particles CyanB-
ML by the above method using the colorant dispersion (2) ² A cyan toner having a / A of 130 and a particle size D50 of 5.6 μm was obtained.
[0159]
-Production of colored particles Magenta B-
ML by the above method using the colorant dispersion (3) ² A Magenta toner having a / A of 132.5 and a particle size D50 of 5.5 μm was obtained.
[0160]
-Production of colored particles YellowB-
ML by the above method using the colorant dispersion (4) ² A yellow toner having a / A of 127 and a particle size D50 of 5.9 μm was obtained.
[0161]
<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 part
[0162]
First, the above components excluding ferrite particles are stirred with a stirrer for 10 minutes to prepare a dispersed coating solution. Next, the coating solution and ferrite particles are placed in a vacuum degassing type kneader and heated at 60 ° C. for 30 minutes. After stirring, the carrier was obtained by further degassing by depressurization while heating and drying. This carrier has a volume resistivity of 10 at the time of an applied electric field of 1000 V / cm. ¹¹ It was Ωcm.
[0163]
( reference Example 1)
100 parts of each of Kuro, Cyan, Magenta and Yellow toner of the colored particles B, 1 part of fatty acid metal salt-coated inorganic oxide fine powder (A), hydrophobic silica having a volume average primary particle size of 40 nm (RX50, Nippon Aerosil Co., Ltd.) (Product) 1.3 parts were added, blended for 10 minutes at a peripheral speed of 32 m / s using a Henschel mixer, and then coarse particles were removed using a sieve of 45 μm mesh to obtain a toner.
100 parts of the carrier and 5 parts of the toner were stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain a developer.
[0164]
Using the developer described above, development property and transferability were evaluated using a copy machine Docu Center Color 400CP manufactured by Fuji Xerox having a tandem system.
Evaluation of developability was carried out by allowing a developer having a toner concentration of 5% by mass to stand overnight in each temperature and humidity environment, copying an image having two 2 cm × 5 cm patches, and measuring the development amount at a hard stop. That is, the developed portions at the two locations on the surface of the photosensitive member were each transferred onto the tape using adhesiveness, the toner adhering tape mass was measured, and the developed amount was obtained by subtracting the tape mass and averaging. .
[0165]
A target value of 4.0 to 5.0 g / m ² In the case of the range, the determination was made as ◯, and the outside of the range as x. For the fogging evaluation, the background part is transferred onto the tape in the same manner, and 1 cm is applied. ² The number of hit toners was counted, and 100 or less was evaluated as ◯, 100 to 500 was evaluated as △, and more than that was evaluated as ×.
[0166]
The transferability is evaluated by performing a hard stop at the end of the transfer process, transferring the toner mass on the surface of the two intermediate transfer members onto the tape in the same manner as described above, measuring the toner adhering tape mass, and subtracting the tape mass and averaging. Thus, the transfer toner amount a was obtained, and similarly, the toner amount b remaining on the surface of the photoreceptor was obtained, and the transfer efficiency was obtained by the following formula (6).
Transfer efficiency η (%) = a × 100 / (a + b) (6)
[0167]
The target value is transfer efficiency η ≧ 99%. Based on this, the determination was made as follows.
・ Η ≧ 99% ・ ・ ・ ○
・ 90% ≦ η <99% ・ ・ ・ △
・ Η <90% ... ×
Regarding the above evaluation, the initial results are shown in Table 1, and the results after 20,000 copies are shown in Table 2.
[0168]
( reference Example 2)
1 part of fatty acid metal salt-coated inorganic oxide fine powder (B) and 1.4 parts of hydrophobic silica having a volume average primary particle size of 40 nm (RX50, manufactured by Nippon Aerosil Co., Ltd.) are added to 100 parts of the above colored particles BKuro, and a Henschel mixer is added. Was used for 10 minutes at a peripheral speed of 32 m / s, and then coarse particles were removed using a 45 μm mesh sieve to obtain a toner.
100 parts of the carrier and 5 parts of the toner were stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain a developer.
[0169]
About the developer reference Evaluation similar to Example 1 was performed. The results are shown in Tables 1 and 2.
[0170]
( reference Example 3)
Fatty acid metal salt-coated inorganic oxide fine powder (C) 0.7 part, volume average primary particle size 50 nm hydrophobic titanium oxide (TAF-500S, manufactured by Fuji Titanium Co., Ltd.) 1.5 part to 100 parts of the above colored particles BKuro After blending for 10 minutes at a peripheral speed of 32 m / s using a Henschel mixer, coarse particles were removed using a sieve of 45 μm mesh to obtain a toner.
100 parts of the carrier and 5 parts of the toner were stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain a developer.
[0171]
About the developer reference Evaluation similar to Example 1 was performed. The results are shown in Tables 1 and 2.
[0172]
( reference Example 4)
1.3 parts of fatty acid metal salt-coated inorganic oxide fine powder (A) and 1.2 parts of hydrophobic silica having a volume average primary particle size of 40 nm (RX50, manufactured by Nippon Aerosil Co., Ltd.) are added to 100 parts of the colored particles AKuro, and Henschel is added. After blending for 10 minutes at a peripheral speed of 32 m / s using a mixer, coarse particles were removed using a sieve of 45 μm mesh to obtain a toner.
100 parts of the carrier and 5 parts of the toner were stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain a developer.
[0173]
About the developer reference Evaluation similar to Example 1 was performed. The results are shown in Tables 1 and 2.
[0174]
( Reference Example 5 )
2 parts of monodispersed spherical silica (A) is added to 100 parts of the colored particles BKuro, blended for 10 minutes at a peripheral speed of 32 m / s using a Henschel mixer, and then the fatty acid metal salt-coated inorganic oxide fine powder (A) 1 1.4 parts of hydrophobic silica (RX50, manufactured by Nippon Aerosil Co., Ltd.) having a volume average primary particle size of 40 nm is added, blended for 5 minutes at a peripheral speed of 20 m / s, and coarse particles are obtained using a sieve of 45 μm mesh. The toner was obtained by removing.
100 parts of the carrier and 5 parts of the toner were stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain a developer.
[0175]
About the developer reference Evaluation similar to Example 1 was performed. The results are shown in Tables 1 and 2.
[0176]
( Reference Example 6 )
After adding 1.5 parts of monodispersed spherical silica (B) to 100 parts of the above colored particles BKuro and blending for 10 minutes at a peripheral speed of 32 m / s using a Henschel mixer, the fatty acid metal salt-coated inorganic oxide fine powder (A ) 1 part, 1.4 parts of hydrophobic silica (RX50, manufactured by Nippon Aerosil Co., Ltd.) having a volume average primary particle size of 40 nm is added, blended for 5 minutes at a peripheral speed of 20 m / s, and coarse particles are obtained using a sieve of 45 μm mesh. The toner was obtained by removing.
100 parts of the carrier and 5 parts of the toner were stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain a developer.
[0177]
About the developer reference Evaluation similar to Example 1 was performed. The results are shown in Tables 1 and 2.
[0178]
( Reference Example 7 )
1 part of monodispersed spherical silica (A), 1 part of fatty acid metal salt-coated inorganic oxide fine powder (A), hydrophobic silica having a volume average primary particle size of 40 nm (RX50, manufactured by Nippon Aerosil Co., Ltd.) 1 4 parts were added, blended for 10 minutes at a peripheral speed of 32 m / s using a Henschel mixer, and then coarse particles were removed using a sieve of 45 μm mesh to obtain a toner.
100 parts of the carrier and 5 parts of the toner were stirred at 40 rpm for 20 minutes using a V-blender and sieved through a sieve having a 177 μm mesh to obtain a developer.
[0179]
About the developer reference Evaluation similar to Example 1 was performed. The results are shown in Tables 1 and 2.
[0180]
(Comparative Example 1)
To 100 parts of the above colored particles BKuro, fine titanium oxide powder MT-150A (particle shape: rice granular, BET specific surface area: 67.5 m) ² / G, 0.7 parts fine powder treated with 10% decyltrimethoxysilane on a volume average primary particle size of 20 nm), 1.2 parts of hydrophobic silica (RX50, manufactured by Nippon Aerosil Co., Ltd.) having a volume average primary particle size of 40 nm. In addition, after blending for 10 minutes at a peripheral speed of 32 m / s using a Henschel mixer, coarse particles were removed using a sieve of 45 μm mesh to obtain a toner.
100 parts of the carrier and 5 parts of the toner were stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having a 177 μm mesh to obtain a developer.
[0181]
About the developer reference Evaluation similar to Example 1 was performed. The results are shown in Tables 1 and 2.
[0182]
(Comparative Example 2)
A developer was obtained in the same manner as in Example 2 except that hydrophobic silica (RX50, manufactured by Nippon Aerosil Co., Ltd.) having an average particle diameter of 40 nm was not used.
[0183]
About the developer reference Evaluation similar to Example 1 was performed. The results are shown in Tables 1 and 2.
[0184]
(Comparative Example 3)
Example 2 is the same as Example 2 except that 1 part of fatty acid metal salt-coated inorganic oxide fine powder (B) is 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.
[0185]
About the developer reference Evaluation similar to Example 1 was performed. The results are shown in Tables 1 and 2.
[0186]
[Table 1]

[0187]
[Table 2]

[0188]
As described above, the inorganic oxide fine powder of the present invention is added with two or more inorganic oxide fine powders having different volume average primary particle sizes, and one of them is coated with a fatty acid metal salt. The developer of the toner composition used is from Reference Examples 1 to 1. 7's As shown in the results, the charge maintaining property was good, and the transfer property was good even in repeated use over a long period of time. In the evaluation of each developer, the photoconductor was extracted after copying 20,000 sheets, and the surface was observed. As a result, scratches and contamination were slight.
[0189]
On the other hand, a developer of a toner composition in which two or more kinds of inorganic oxide fine powders having different volume average primary particle diameters are added but the inorganic oxide fine powder whose surface is coated with a fatty acid metal salt is not used is a comparative example. As in the result of 1, the transferability was slightly inferior in long-term repeated use, fogging was generated, and the charge retention was poor. When the photoconductor was extracted after copying 20,000 sheets and the surface was observed, it was confirmed that the scratch was clear. Further, the developer of the toner composition to which only a small particle size inorganic oxide fine powder was added had insufficient transferability from the beginning as in the results of Comparative Examples 2 and 3.
[0190]
( Reference Example 8 )
Reference Example 5 Except that the cleaning blade of the system was removed, an electrostatic brush made of a 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. Reference Example 5 Evaluation was performed in the same manner as above.
As a result, a clear image was displayed as well as the initial image after copying 20,000 sheets, and no image problems occurred.
[0191]
( Reference Example 9 )
Reference Example 5 In the above, except that the system blade and brush cleaning are not used at all, and the toner is collected by the developing device using a scorotron charger. Reference Example 5 Evaluation was performed in the same manner as above.
As a result, a clear image was displayed as well as the initial image after copying 20,000 sheets, and no image problems occurred.
[0192]
( Reference Example 10 )
Reference Example 5 In this example, the surface material of the transfer belt is changed to PFA, and a device for heating from the back side is provided so that the simultaneous transfer and fixing can be performed. Reference Example 5 When four colors were produced using the modified external additive composition and examined by combining the colors, a clear image quality close to the photographic image quality could be obtained.
[0193]
【The invention's effect】
As described above, according to the present invention, the toner fluidity, charging property, developing property, transfer property, cleaning property, and fixing property can be satisfied at the same time for a long time, and further, the occurrence of scratches on the latent image carrier is prevented. In addition, it does not have a blade cleaning process that promotes wear of the latent image carrier and improves the problem of collecting residual toner at the same time as development or collecting residual toner on the surface of the latent image carrier using an electrostatic brush. An electrostatic charge image dry toner composition and a developer for developing an electrostatic latent image using the same can be provided. Furthermore, it is possible to provide an image forming method capable of developing, transferring, and fixing corresponding to high image quality requirements.
[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 diagram for explaining a method of measuring a volume specific resistance value of a carrier.
[Explanation of symbols]
1Y, 1M, 1C, 1K Photosensitive drum (latent image carrier)
3Y, 3M, 3C, 3K latent image forming means
4Y, 4M, 4C, 4K Developer
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 Transferee
17 Cleaning member
18 Fixing device
20Y, 20M, 20C, 20K charger (charging means)
40Y, 40M, 40C, 40K Development unit
52 Upper electrode
53 Sample to be measured
54 Lower electrode
55 High Voltage Resistance Meter

Claims (9)

An electrostatic charge image dry toner composition containing a binder resin, a colorant and a release agent,
The volume average particle diameter D50 is in the range of ² to 8 μm, the average shape index SF1 (ML ² / A) is in the range of 100 to 140,
The electrostatic charge image dry toner composition contains two or more inorganic oxide fine powders having different volume average primary particle diameters, and one of them is an inorganic material whose surface is coated with a fatty acid metal salt. Oxide fine powder,
Further, it contains monodispersed spherical silica having a specific gravity in the range of 1.2 to 1.9, a volume average primary particle size of 80 to 300 nm, and a standard deviation of (volume average primary particle size × 0.22) or less. An electrostatic charge image dry toner composition.   Among the two or more types of inorganic oxide fine powders having different volume average primary particle sizes, one type of volume average primary particle size is 5 nm or more and less than 30 nm, and the other one type of volume average primary particle size is 30 nm or more and 70 nm. The electrostatic charge image dry toner composition according to claim 1, wherein   The electrostatic charge image according to claim 1 or 2, wherein the surface of the inorganic oxide fine powder whose surface is coated with the fatty acid metal salt is coated with a fatty acid metal salt in 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 a resin coating layer in which a conductive material is dispersed and contained in a matrix resin on the surface of the core material, and the toner composition The product contains a binder resin, a colorant, and a release agent, the volume average particle diameter D50 is in the range of ² to 8 μm, the average shape index SF1 (ML ² / A) is in the range of 100 to 140, and the volume Two or more inorganic oxide fine powders having different average primary particle diameters are contained, and one of them is an inorganic oxide fine powder whose surface is coated with a fatty acid metal salt, and has a specific gravity of 1.2 to A toner composition containing monodispersed spherical silica having a range of 1.9, a volume average primary particle size of 80 to 300 nm, and a standard deviation of (volume average primary particle size × 0.22) or less. A developer for developing an electrostatic latent image.   5. The electrostatic latent image development according to claim 4, wherein the surface of the inorganic oxide fine powder whose surface is coated with the fatty acid metal salt is coated with a fatty acid metal salt in a thickness of 0.5 to 5 nm. Developer. A charging means for uniformly charging the latent image carrier, a latent image forming means for forming an electrostatic latent image by exposing the surface of the charged latent image carrier, and a toner using the electrostatic latent image as a toner composition Image formation that forms an image using an image forming apparatus that includes a developing unit that develops the image, a transfer unit that transfers the formed toner image to a recording material, and a fixing unit that fixes the transferred toner image on the surface of the recording material A method,
The toner composition contains a binder resin, a colorant, and a release agent, and has a volume average particle diameter D50 in the range of ² to 8 μm and an average shape index SF1 (ML ² / A) in the range of 100 to 140. And containing two or more kinds of inorganic oxide fine powders having different volume average primary particle diameters, and one of them is an inorganic oxide fine powder having a surface coated with a fatty acid metal salt, and a specific gravity of 1 A toner composition containing monodispersed spherical silica having a range of 2 to 1.9, a volume average primary particle size of 80 to 300 nm, and a standard deviation of (volume average primary particle size × 0.22) or less. And
An image forming method, wherein the transfer means is a transfer means for developing each color toner on a latent image carrier and transferring it to an intermediate transfer body, and then transferring each color toner to a recording material at once. A charging means for uniformly charging the latent image carrier, a latent image forming means for exposing the charged latent image carrier to form an electrostatic latent image, and a toner using the electrostatic latent image as a toner composition Developing means for developing the image, transfer means for transferring the formed toner image to the recording material, cleaning means for removing the toner remaining on the surface of the latent image carrier after the transfer, and fixing the transferred toner image on the surface of the recording material 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 has a volume average particle diameter D50 in the range of ² to 8 μm and an average shape index SF1 (ML ² / A) in the range of 100 to 140. And containing two or more kinds of inorganic oxide fine powders having different volume average primary particle diameters, and one of them is an inorganic oxide fine powder having a surface coated with a fatty acid metal salt, and a specific gravity of 1 A toner composition containing monodispersed spherical silica having a range of 2 to 1.9, a volume average primary particle size of 80 to 300 nm, and a standard deviation of (volume average primary particle size × 0.22) or less. And
An image forming method, wherein the cleaning means collects residual toner on the surface of the latent image carrier using an electrostatic brush without rubbing the latent image carrier with a blade. A charging means for uniformly charging the latent image carrier, a latent image forming means for forming an electrostatic latent image by exposing the surface of the charged latent image carrier, and a toner using the electrostatic latent image as a toner composition 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 the transfer, and fixing the transferred toner image on the surface of the recording material 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 has a volume average particle diameter D50 in the range of ² to 8 μm and an average shape index SF1 (ML ² / A) in the range of 100 to 140. And containing two or more kinds of inorganic oxide fine powders having different volume average primary particle diameters, and one of them is an inorganic oxide fine powder having a surface coated with a fatty acid metal salt, and a specific gravity of 1 A toner composition containing monodispersed spherical silica having a range of 2 to 1.9, a volume average primary particle size of 80 to 300 nm, and a standard deviation of (volume average primary particle size × 0.22) or less. And
An image forming method, wherein the cleaning means collects residual toner on the surface of the latent image carrier using a developing device without rubbing the latent image carrier with a blade. A charging means for uniformly charging the latent image carrier, a latent image forming means for forming an electrostatic latent image by exposing the surface of the charged latent image carrier, and a toner using the electrostatic latent image as a toner composition An image forming method for forming an image using an image forming apparatus including a developing unit that develops an image and a transfer fixing unit that transfers the formed toner image to an intermediate transfer member and fixes the toner image to a recording material at the same time Because
The toner composition contains a binder resin, a colorant, and a release agent, and has a volume average particle diameter D50 in the range of ² to 8 μm and an average shape index SF1 (ML ² / A) in the range of 100 to 140. And containing two or more kinds of inorganic oxide fine powders having different volume average primary particle diameters, and one of them is an inorganic oxide fine powder having a surface coated with a fatty acid metal salt, and a specific gravity of 1 A toner composition containing monodispersed spherical silica having a range of 2 to 1.9, a volume average primary particle size of 80 to 300 nm, and a standard deviation of (volume average primary particle size × 0.22) or less. And
An image forming method, wherein the transfer and fixing means develops each color toner on a latent image carrier and transfers it to an intermediate transfer body, and thereafter, transfers each color to a recording material at a time and fixes it simultaneously.

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