JP3595631B2

JP3595631B2 - Toner for developing electrostatic images

Info

Publication number: JP3595631B2
Application number: JP21693696A
Authority: JP
Inventors: 圭太野沢; 由紀唐木; 茂登男浦和; 寛遊佐; 一夫丸山; 雅雄高野
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 1996-07-31
Filing date: 1996-07-31
Publication date: 2004-12-02
Anticipated expiration: 2016-07-31
Also published as: JPH1048872A

Description

【０００１】
【発明の属する技術分野】
本発明は電子写真法、静電記録法、磁気記録法などを利用した記録方法に用いられるトナーに関するものである。詳しくは本発明は予め静電潜像担持体上にトナー像を形成後、転写材上に転写させて画像形成する複写機、プリンター、ファックスに用いられるトナーに関する。
【０００２】
【従来の技術】
従来、電子写真法としては多数の方法が知られているが、一般には光導電性物質を利用し、種々の手段により感光体上に電気的潜像を形成し、次いで、該潜像をトナーで現像を行って可視像化し、必要に応じて紙などの転写材にトナー像を転写した後に、熱／圧力により転写材上にトナー像を定着して最終画像を得るものである。
【０００３】
近年電子写真法を用いた複写機、プリンター、ファックスは、カラー化の需要が大きくなっている。一般にカラートナーはその色味の関係で磁性体を含有した磁性トナーを用いることが困難なため、非磁性トナーが用いられる。黒トナーに磁性トナーを用い、カラートナーに非磁性トナーを用いた場合、非磁性トナーはその最適な転写電流値が磁性トナーの最適転写電流値より高い値になる傾向がある。機器本体の転写条件を非磁性トナーに合わせた場合、磁性トナーは一旦転写材上に転写されたトナーが潜像担持体上に戻ってしまう「再転写」と呼ばれる現象がおこり、黒画像の画像濃度の低下を起こす。
【０００４】
また、近年ペーパーマテリアルのさらなる多様化が進んでいることにより、電子写真法を用いた複写機、プリンター、ファックスはそれらの多用なペーパーマテリアルに対応出来ることが要求されている。しかしながら、転写材であるペーパーマテリアルによってその最適な転写条件は異なる。例えば、厚紙やＯＨＴフィルムではその最適転写電流値は高い値になる。一方、薄い紙ではその最適転写電流値は低い値となり、機器本体の転写条件を厚紙やＯＨＴフィルムに対して最適化するとやはり「再転写」現象が起きてしまう。
【０００５】
特開平２−６６５５９号公報、特開平２−８７１５９号公報、特開平２−１４６５５７号公報、特開平２−１６７５６６号公報、特開平５−６１２５１号公報等に、トナーに機械的衝撃処理を施すことにより転写率が改善できるという提案がなされている。
【０００６】
これらに提案されている方法では、そのトナーにとって最も転写効率の良い転写条件に合わせたところでの転写率は確かに向上するが、それよりも高い転写電流値に設定したときの転写効率はほとんど改善されず、「再転写」の改善には効果がない。
【０００７】
【発明が解決しようとする課題】
本発明の目的は、上記従来技術の問題点を解決した静電荷像現像用トナーを提供することにある。
【０００８】
即ち、本発明の目的は、幅広い転写電流条件（特に高い転写電流条件において）で「再転写」を起こさず高い画像濃度が得られる静電荷像現像用トナーを提供することにある。
【０００９】
さらに、本発明の目的は、画像濃度が高く、良好な画質の画像が得られる静電荷像現像用トナーを提供することにある。
【００１０】
【課題を解決するための手段】
本発明は、結着樹脂及び着色剤を少なくとも含有するトナー粒子及び該トナー粒子に外添される無機微粒子を有する静電荷像現像用トナーにおいて、
該トナー粒子が、少なくとも結着樹脂及び着色剤を溶融混練する工程、それを粉砕する工程及び粉砕工程後機械的衝撃力を加えて球形化処理を施す工程を少なくとも経て製造されたものであり、
該無機微粒子は、平均粒径０．０５〜２．０μｍの下記式（１）
Ｍ_xＯ_y ・・・（１）
（式中、Ｍは、アルミニウム元素，チタニウム元素，亜鉛元素又はジルコニウム元素を示し、Ｏは酸素元素を示し、ｘ及びｙは０でない正の数を示す。）
で表される金属酸化物微粒子を有しており、
該トナーは、示差熱分析における吸熱ピークを１２０℃以下にひとつ以上有しており、
該トナーは、画像解析装置で測定した形状係数ＳＦ−１の値が１１０乃至１８０の範囲内であり、形状係数ＳＦ−２の値が１１０乃至１４０の範囲内であり、ＳＦ−２の値から１００を引いた値ＢとＳＦ−１の値から１００を引いた値Ａとの比Ｂ／Ａが１．０以下であることを特徴とする静電荷像現像用トナーに関する。以下において、「本発明１」は特にこの構成のトナーを意味する。
【００１１】
また本発明は、結着樹脂及び着色剤を少なくとも含有するトナー粒子及び該トナー粒子に外添される無機微粒子を有する静電荷像現像用トナーにおいて、
該トナー粒子が、少なくとも結着樹脂及び着色剤を溶融混練する工程、それを粉砕する工程及び粉砕工程後機械的衝撃力を加えて球形化処理を施す工程を少なくとも経て製造されたものであり、
該無機微粒子は、平均粒径０．１〜３．０μｍの下記式（２）又は（３）
Ｍ_xＴｉ_yＯ_z ・・・（２）
Ｍ_xＳｉ_yＯ_z ・・・（３）
（式中、Ｍは金属元素を示し、Ｔｉはチタニウム元素を示し、Ｓｉはケイ素元素を示し、Ｏは酸素元素を示し、ｘ及びｙは０でない正の数を示す。）
で表される複合金属酸化物微粒子を有しており、
該トナーは、示差熱分析における吸熱ピークを１２０℃以下にひとつ以上有しており、
該トナーは、画像解析装置で測定した形状係数ＳＦ−１の値が１１０乃至１８０の範囲内であり、形状係数ＳＦ−２の値が１１０乃至１４０の範囲内であり、ＳＦ−２の値から１００を引いた値ＢとＳＦ−１の値から１００を引いた値Ａとの比Ｂ／Ａが１．０以下であることを特徴とする静電荷像現像用トナーに関する。以下において、「本発明２」は特にこの構成のトナーを意味する。
【００１２】
また本発明は、結着樹脂及び着色剤を少なくとも含有するトナー粒子及び該トナー粒子に外添される無機微粒子を有する静電荷像現像用トナーにおいて、
該トナー粒子が、少なくとも結着樹脂及び着色剤を溶融混練する工程、それを粉砕する工程及び粉砕工程後機械的衝撃力を加えて球形化処理を施す工程を少なくとも経て製造されたものであり、
該無機微粒子は、平均粒径が０．０５〜２．０μｍの無機炭化物微粒子を有しており、
該トナーは、示差熱分析における吸熱ピークを１２０℃以下にひとつ以上有しており、
該トナーは、画像解析装置で測定した形状係数ＳＦ−１の値が１１０乃至１８０の範囲内であり、形状係数ＳＦ−２の値が１１０乃至１４０の範囲内であり、ＳＦ−２の値から１００を引いた値ＢとＳＦ−１の値から１００を引いた値Ａとの比Ｂ／Ａが１．０以下であることを特徴とする静電荷像現像用トナーに関する。以下において、「本発明３」は特にこの構成のトナーを意味する。
【００１３】
また本発明は、結着樹脂及び着色剤を少なくとも含有するトナー粒子及び該トナー粒子に外添される無機微粒子を有する静電荷像現像用トナーにおいて、
該トナー粒子が、少なくとも結着樹脂及び着色剤を溶融混練する工程、それを粉砕する工程及び粉砕工程後機械的衝撃力を加えて球形化処理を施す工程を少なくとも経て製造されたものであり、
該無機微粒子は、平均粒径０．０５〜２．０μｍの金属炭酸塩微粒子を有しており、
該トナーは、示差熱分析における吸熱ピークを１２０℃以下にひとつ以上有しており、
該トナーは、画像解析装置で測定した形状係数ＳＦ−１の値が１１０乃至１８０の範囲内であり、形状係数ＳＦ−２の値が１１０乃至１４０の範囲内であり、ＳＦ−２の値から１００を引いた値ＢとＳＦ−１の値から１００を引いた値Ａとの比Ｂ／Ａが１．０以下であることを特徴とする静電荷像現像用トナーに関する。以下において、「本発明４」は特にこの構成のトナーを意味する。
【００１４】
さらに本発明は、結着樹脂及び着色剤を少なくとも含有するトナー粒子及び該トナー粒子に外添される無機微粒子を有する静電荷像現像用トナーにおいて、
該トナー粒子が、少なくとも結着樹脂及び着色剤を溶融混練する工程、それを粉砕する工程及び粉砕工程後機械的衝撃力を加えて球形化処理を施す工程を少なくとも経て製造されたものであり、
該無機微粒子は、シリコーンオイルを含有した平均粒径０．０３〜５０μｍのケイ素酸化物微粒子又はケイ素複合酸化物微粒子を有しており、
該トナーは、示差熱分析における吸熱ピークを１２０℃以下にひとつ以上有しており、
該トナーは、画像解析装置で測定した形状係数ＳＦ−１の値が１１０乃至１８０の範囲内であり、形状係数ＳＦ−２の値が１１０乃至１４０の範囲内であり、ＳＦ−２の値から１００を引いた値ＢとＳＦ−１の値から１００を引いた値Ａとの比Ｂ／Ａが１．０以下であることを特徴とする静電荷像現像用トナーに関する。以下において、「本発明５」は特にこの構成のトナーを意味する。
【００１５】
本発明者らは、「再転写」を解決する目的で検討したところ、転写前のトナーの帯電量を大きくすることにより「再転写」が解決できることを見いだした。
【００１６】
【発明の実施の形態】
上記微粒子をトナー母粒子に外添し、且つ、示差熱分析における吸熱ピークが１２０℃以下にひとつ以上有するトナーを用いることにより、上記の転写前の静電荷潜像担持体或いは中間転写体上のトナーの帯電量を従来よりも高くすることができ、「再転写」を防止することが出来た。
【００１７】
現像時及び転写時に、上記微粒子はトナー母体から分離し、微粒子がトナー母体自体に電荷を付与し、転写前のトナーの帯電量を高めるために「再転写」が防止できるものと考えている。
【００１８】
本発明１，３及び４において微粒子の平均粒径が０．０５μｍ未満、本発明２において微粒子の平均粒径が０．１μｍ未満では、微粒子のトナー表面への付着力が大きすぎ、現像時／転写時にトナー母体からの分離が十分に起こらず、転写前のトナーの帯電量を高めることが出来ないために「再転写」防止に効果がない。
【００１９】
本発明１，３及び４において微粒子の平均粒径が２．０μｍを、本発明２において微粒子の平均粒径が３．０μｍ超えると、微粒子の表面積が小さく転写前のトナーのトリボを高める効果が小さく「再転写」防止の効果がない。また、微粒子を核にしてトナー粒子の凝集が起こり、カブリの増加を招く場合もある。
【００２０】
また、本発明５のトナーには、粒径が０．０３〜５０μｍ（好ましくは０．０４〜１μｍ）であるシリコーンオイルを含有した比較的粒径の大きいケイ素酸化物微粒子又はケイ素複合酸化物微粒子が外添されるが、シリコーンオイルを含有した上記微粒子の粒径が０．０３μｍ未満であると、シリコーンオイルを含有した上記微粒子がトナー表面に強く付着力しすぎ、現像時／転写時にトナー母体からの分離が十分に起こらず、転写前のトナーの帯電量を高めることが出来ないために「再転写」防止に効果がない。
【００２１】
シリコーンオイルを含有した上記微粒子の粒径が５０μｍを超えると、「再転写」防止の効果が十分に得られない。
【００２２】
微粒子はトナー母体に外添された形態で用いる。微粒子がトナー母体中に内添された状態及びトナー表面に強く固着された状態にあると、転写前のトナーの帯電量を高めることが出来ず、「再転写」防止に効果がない。
【００２３】
本発明１〜４において上記微粒子は、その鉄粉キャリアに対する帯電極性が、トナーと同じ極性にあるものが好ましい。微粒子の帯電極性がトナーと同じ帯電極性にある場合は、画像濃度がより高く、カブリもより抑制できる。
【００２４】
また、本発明１，２及び４において上記微粒子は、その鉄粉キャリアに対する帯電量が絶対値で｜２０｜μＣ／ｇ以下、より好ましくは｜１０｜μＣ／ｇ以下であることが好ましい。本発明３の無機炭化物である場合は、その鉄粉キャリアに対する帯電量が絶対値で｜３０｜μＣ／ｇ以下、より好ましくは｜２０｜μＣ／ｇ以下であることが好ましい。微粒子の帯電量が上記範囲にある場合は、画像濃度がより高く、カブリもより抑制できる。
【００２５】
上記微粒子のトナー中への添加量は、本発明１〜４ではトナー１００質量部に対して０．０１〜３．０質量部（より好ましくは、０．０５〜１．０質量部）であることが好ましい。本発明５ではトナー１００質量部に対して０．１〜１０質量部（より好ましくは０．１〜２．０質量部）であることが好ましい。
【００２６】
微粒子のトナー中への添加量が上記下限値を下回ると、転写前のトナーの帯電量を高める効果が不十分であり、「再転写」防止の効果が十分に得られない。微粒子のトナー中への添加量が上限値を上回ると、カブリが発生しやすくなる。
【００２７】
次に、本発明１〜５に係る各微粒子の素材について詳しく説明する。
【００２８】
本発明１のトナーに用いる化学式Ｍ_ｘＯ_ｙで表現される化合物の微粒子としては、Ｍは、アルミニウム，チタニウム，亜鉛，ジルコニウムのいずれかの元素である。
【００２９】
さらにこれらの中でも、チタニウムの酸化物が、より好ましい。チタニウムの酸化物微粒子を用いた場合、さらに画像濃度が高く、カブリもより抑制できる。
【００３０】
特に、ルチル型の結晶形を有するチタニウムの酸化物である場合に、「再転写」防止の効果がより高くなる。
【００３１】
また、１種のＭ^１ _ｘＯ_ｙ微粒子の表面に別のＭ^２ _ｘＯ_ｙが付着・被覆している形態や、２種以上のＭ_ｘＯ_ｙが混晶している形態でもかまわない。また、微粒子表面が疎水化処理されていてもかまわない。
【００３２】
本発明２のトナーに用いるＭ_ｘＴｉ_ｙＯ_ｚとしては、Ｍは、例えば、ストロンチウム，バリウム，マグネシウム，カルシウム等の元素が挙げられる。また、Ｍ_ｘＳｉ_ｙＯ_ｚとしては、Ｍは、例えば、ストロンチウム，バリウム，マグネシウム，カルシウム等の元素が挙げられる。
【００３３】
これらの中でも、Ｍがストロンチウムである場合が、特に「再転写」防止の効果が高く好ましい。
【００３４】
また、ひとつの種類のものの表面に別のものが、付着・被覆している形態や、２種以上のものが混晶している形態でもかまわない。また、微粒子表面が疎水化処理されていてもかまわない。
【００３５】
本発明３に用いる無機炭化物としては、ホウ素，ケイ素，チタニウム，バナジウム，ジルコニウム，モリブデン，タングステン等の炭化物が挙げられる。これらの中でも、ホウ素あるいはケイ素の炭化物が「再転写」防止の効果が、より高く好ましい。さらにこれらの中でも、特にケイ素の炭化物が一段と「再転写」防止の効果が、より高く好ましい。
【００３６】
本発明４に用いる金属炭酸塩微粒子としては、マグネシウム，カルシウム，ストロンチウム，バリウム等の炭酸塩を挙げることができる。これらの中でも、ストロンチウムの炭酸塩微粒子が「再転写」防止の効果が、より高く特に好ましい。また、炭酸水素塩の形態のものでもかまわない。また、表面が疎水化処理をされていてもかまわない。
【００３７】
本発明５に用いるケイ素酸化物微粒子としては、例えば、ケイ素ハロゲン化物の蒸気相酸化により生成されたいわゆる乾式法又はヒュームドシリカと称される乾式シリカ、及び水ガラス等から製造されるいわゆる湿式シリカの両者が使用可能であるが、表面及びシリカ微粉体の内部にあるシラノール基が少なく、またＮａ_２Ｏ、ＳＯ^３−等の製造残滓の少ない乾式シリカの方が好ましい。またケイ素複合酸化物微粒子としては、製造工程において例えば、塩化アルミニウム，塩化チタンの如き他の金属ハロゲン化合物をケイ素ハロゲン化合物と共に用いることによって得られる、ケイ素酸化物と他の金属酸化物との複合酸化物微粒子が挙げられ、本発明においては、それらも包含する。
【００３８】
ケイ素酸化物又は複合酸化物微粒子がシリコーンオイルを含有しない場合は、再転写防止の効果はほとんど得られない。ケイ素酸化物又は複合酸化物の比較的極性の強い表面とシリコーンオイルとの相互作用により、シリコーンオイルがある種の活性の高い状態になって、感光体上に現像するトナーの帯電量を高めることができるためと考えられる。
【００３９】
シリコーンオイルの形態としては、微粒子の表面を被覆する形態のほかに、微粒子がシリコーンオイルにより造粒された凝集体の形態をとるものも好ましく用いられる。
【００４０】
シリコーンオイルが微粒子の表面を被覆する形態の場合は、もとの微粒子のＢＥＴ比表面積は１００ｍ^２／ｇ以下、より好ましくは７０ｍ^２／ｇ以下であることが好ましい。また、微粒子がシリコーンオイルにより造粒された凝集体の形態の場合は、ＢＥＴ比表面積は１００ｍ^２／ｇ〜４００ｍ^２／ｇであることが好ましい。
【００４１】
また、ケイ素酸化物又は複合酸化物粒子は、シリコーンオイルを含有する前に予めカップリング剤等により疎水化されたものを用いても良い。
【００４２】
好ましいシリコーンオイルの粘度としては、シリコーンオイルが微粒子の表面を被覆する形態の場合は、２５℃における粘度が０．５〜１００００センチストークス、好ましくは１〜１０００センチストークス、さらに好ましくは１０〜２００センチストークスのものが用いられる。また、微粒子がシリコーンオイルにより造粒された凝集体の形態の場合は、２５℃における粘度が５０〜２０００００センチストークス、好ましくは５００〜１５００００センチストークスのものが用いられる。
【００４３】
好ましいシリコーンオイルの種類としては、例えばジメチルシリコーンオイル、メチルフェニルシリコーンオイル、α−メチルスチレン変性シリコーンオイル、クロルフェニルシリコーンオイル、フッ素変性シリコーンオイル、アミノ変性シリコーンオイル等を挙げることができる。
【００４４】
シリコーンオイル処理の方法としては、例えばシランカップリング剤で処理されたシリカ微粉体とシリコーンオイルとをヘンシェルミキサー等の混合機を用いて直接混合してもよいし、ベースとなるシリカ微粉体にシリコーンオイルを噴霧する方法を用いてもよい。あるいは適当な溶剤にシリコーンオイルを溶解あるいは分散せしめた後、シリカ微粉体を加え混合し溶剤を除去する方法でもよい。
【００４５】
また、処理後に無機微粉体を不活性ガス中で２００℃以上（より好ましくは２５０℃以上）に加熱し、表面のコートを安定化させることがより好ましい。
【００４６】
本発明のこれらのトナーはその示差熱分析における吸熱ピークが１２０℃以下に（好ましくは１１０℃以下に）ひとつ以上ある。
【００４７】
示差熱分析における吸熱ピークが１２０℃以下にない場合は、本発明の微粒子を外添することによる「再転写」防止の効果が十分に得られない。
【００４８】
示差熱分析における吸熱ピークが１２０℃以下にあるトナーは、その製造における溶融混練工程においてバインダー樹脂中の磁性体／荷電制御剤等の分散の状態が、吸熱ピークが１２０℃以下に有しないトナーとは異なるある特異な状態になるものと推測される。そのある特定の状態が、本発明の特定の微粒子の「再転写」防止の効果が働きやすい状態にするものと考えている。
【００４９】
示差熱分析における吸熱ピークが１２０℃以下に少なくともひとつあれば効果はあり、さらに吸熱ピークが１２０℃を超えるところにあっても構わない。但し、示差熱分析における吸熱ピークは６０℃以下（好ましくは７０℃以下）に存在しないものが好ましい。示差熱分析における吸熱ピークは６０℃以下に存在する場合は、画像濃度が低くなる傾向がある。また、保存性も不安定になる傾向にある。
【００５０】
示差熱分析における吸熱ピークを１２０℃以下に有する形態にする手段としては、トナー中に示差熱分析における吸熱ピークを１２０℃以下に有する化合物を内添させる方法が好ましい。
【００５１】
示差熱分析における吸熱ピークを１２０℃以下にひとつ以上有する物質としては、樹脂あるいはワックスを挙げることができる。
【００５２】
樹脂としては、結晶性を有するポリエステル樹脂、シリコーン樹脂等を挙げることができる。
【００５３】
ワックスとしては、パラフィンワックス、マイクロクリスタリンワックス、ペトロラクタム等の石油系ワックス及びその誘導体、モンタンワックス及びその誘導体、フィシャートロプシュ法による炭化水素ワックス及びその誘導体、ポリエチレンに代表されるポリオレフィンワックス及びその誘導体、カルナバワックス、キャンデリラワックス等、天然ワックス及びそれらの誘導体等で、誘導体には酸化物や、ビニルモノマーとのブロック共重合物、グラフト変性物も含む。高級脂肪族アルコール等のアルコール；ステアリン酸、パルミチン酸等の脂肪酸或いはその化合物；酸アミド、エステル、ケトン、硬化ヒマシ油及びその誘導体、植物ワックス、動物ワックス等、示差熱分析における吸熱ピークを１２０℃以下に有しているものであればどれも用いることが可能である。
【００５４】
これらの中でも、示差熱分析における吸熱ピークを１２０℃以下に有する化合物が、ポリオレフィンもしくはフィッシャートロプシュ法による炭化水素ワックスもしくは石油系ワックスもしくは高級アルコールである場合、さらには、ポリオレフィンもしくはフィッシャートロプシュ法による炭化水素ワックスもしくは石油系ワックスである場合が本発明のトナーにおいては特に好ましい。
【００５５】
上記のある特定の化合物を用いた場合、「再転写」防止の効果がさらに高くなる。
【００５６】
これらの化合物は比較的それ自身の極性が低く、トナー母体の帯電を安定させるものと考えられる。そのことが本発明の微粒子の「再転写」防止の効果をさらに働きやすくするものと考えている。
【００５７】
また、これらの中でも、示差熱分析における吸熱ピークを１２０℃以下に有する化合物が、ポリオレフィンもしくはフィッシャートロプシュ法による炭化水素ワックスもしくは石油系ワックスもしくは高級アルコールは、そのＧＰＣ測定での重量平均分子量（Ｍｗ）と個数平均分子量（Ｍｎ）の比（Ｍｗ／Ｍｎ）が１．０〜２．０である場合、「再転写」防止の効果がさらに高くなる。（Ｍｗ／Ｍｎ）が１．０〜２．０である分子量分布がかなリシャープな上記ワックスをトナー中に含有させることにより、トナーの製造における溶融混練工程においてバインダー樹脂中の磁性体，荷電制御剤等の分散の状態が本発明にとってより好ましい状態になるためと考えている。
【００５８】
本発明の１乃至５のトナーは、「再転写」防止の効果を高くするために、トナー粒子の画像解析装置で測定した形状係数ＳＦ−１の値が１１０＜ＳＦ−１≦１８０（さらに好ましくは、１２０＜ＳＦ−１≦１６０）、形状係数ＳＦ−２の値が１１０＜ＳＦ−２≦１４０（さらに好ましくは、１１５＜ＳＦ−２≦１４０）であり、かつＳＦ−２の値から１００を引いた値ＢとＳＦ−１の値から１００を引いた値Ａとの比Ｂ／Ａが１．０以下である必要がある。上記の範囲にある形状は、比較的トナー表面が滑らかで凹凸の少ない形状である。このような形状の場合は、トナーに外添された微粒子がより効果的に働き、「再転写」防止効果を高めるものと考えられる。
【００５９】
ＳＦ−１が１１０以下である場合、ＳＦ−２が１１０以下である場合、及びＢ／Ａが１．０未満である場合、潜像担持体上に残った転写残トナーのクリーニングが難しくなり、クリーニング不良が発生しやすい。ＳＦ−１が１８０を超える場合、及び、ＳＦ−２が１４０を超える場合は、「再転写」防止効果のさらなる向上が十分に得られない。
【００６１】
本発明のトナーの形状を上記の範囲にするためには、以下の方法が挙げられる。
【００６２】
機械衝撃式の微粉砕装置を用いて微粉砕をする方法やジェット式の粉砕において、その粉砕圧を通常より下げて循環回数を増して微粉砕する方法が挙げられる。また、微粉砕された或いはさらに分級されたトナー粒子を水中に分散させ加熱する湯浴法、熱気流中を通過させる熱処理法、機械的エネルギーを付与して処理する機械的衝撃法などが挙げられる。
【００６３】
これらの中でも、機械的衝撃力による処理を加える方法が好ましい。機械的衝撃力を加える処理としては、例えば、川崎重工社製のクリプトロンシステムやターボ工業社製のターボミル等の機械衝撃式の粉砕機によリトナーに機械的衝撃力を加える方法の他、ホソカワミクロン社製のメカノフュージョンシステムや奈良機械製作所社製のハイブリダイゼーションシステム等の装置の様に、高速回転する羽根によりトナーをケーシングの内側に遠心力により押し付け、圧縮力，摩擦力等の力によりトナーに機械的衝撃力を加える方法が挙げられる。
【００６４】
機械的衝撃力を加える処理は、トナーの微粉砕工程の後、或いは、さらに分級工程を経た後に行う場合、「再転写」防止の効果がさらに高まり特に好ましい。また、機械衝撃処理を施すことにより、トナー表面が本発明の微粒子の作用がより働きやすい「ある特異な表面状態」になるためと考えている。
【００６５】
本発明に用いうる結着樹脂としては、以下のようなものが挙げられる。加熱定着用トナーの場合は、例えば、ポリスチレン、ポリ−ｐ−クロルスチレン、ポリビニルトルエン等のスチレン及びその置換体の単重合体；スチレン−ビニルナフタリン共重合体、スチレン−アクリル酸エステル共重合体、スチレン−メタクリル酸エステル共重合体、スチレン−マレイン酸エステル共重合体、スチレン−アクリル酸共重合体、スチレン−メタクリル酸共重合体、スチレン−マレイン酸共重合体、スチレン−α−クロルメタクリル酸メチル共重合体、スチレン−アクリロニトリル共重合体、スチレン−ビニルメチルエーテル共重合体、スチレン−ビニルエチルエーテル共重合体、スチレン−ビニルメチルケトン共重合体、スチレン−ブタジエン共重合体、スチレン−イソプレン共重合体、スチレン−アクリロニトリルインデン共重合体等のスチレン系共重合体；ポリ塩化ビニル、フェノール樹脂、天然変性フェノール樹脂、天然樹脂変性マレイン酸樹脂、アクリル樹脂、メタクリル樹脂、ポリ酢酸ビニル、シリコーン樹脂、ポリエステル樹脂、ポリウレタン、ポリアミド樹脂、フラン樹脂、エポキシ樹脂、キシレン樹脂、ポリビニルブチラール、テンペン樹脂、クマロンインデン樹脂、石油系樹脂などが使用できる。
【００６６】
これらの中でも、スチレン系共重合体が、「再転写」防止の効果をさらに高くし、特に好ましい。
【００６７】
スチレン系共重合体は比較的それ自身の主鎖の極性が低く、トナー母体の帯電を安定させるものと考えられる。そのことが本発明の微粒子の「再転写」防止の効果をさらに働きやすくするものと考えている。
【００６８】
スチレン系共重合体のスチレンモノマーに対するコモノマーとしては、例えば、アクリル酸、アクリル酸メチル、アクリル酸エチル、アクリル酸ブチル、アクリル酸ドデシル、アクリル酸オクチル、アクリル酸−２−エチルヘキシル、アクリル酸フェニル、メタクリル酸、メタクリル酸メチル、メタクリル酸エチル、メタクリル酸ブチル、メタクリル酸オクチル、アクリロニトリル、メタクリロニトリル、アクリルアミド等のような二重結合を有するモノカルボン酸、もしくはその置換体；アクリル酸、メタクリル酸、α−エチルアクリル酸、クロトン酸、などのアクリル酸及びそのα−或いはβ−アルキル誘導体、フマル酸、マレイン酸、シトラコン酸などの不飽和ジカルボン酸及びそのモノエステル誘導体または無水マレイン酸などがあり、このようなモノマーを単独、或いは混合して、他のモノマーと共重合させることにより所望の重合体を作ることができる。
【００６９】
この中でも、特に不飽和ジカルボン酸のモノエステル誘導体を用いることが好ましい。より具体的には、例えば、マレイン酸モノメチル、マレイン酸モノエチル、マレイン酸モノブチル、マレイン酸モノオクチル、マレイン酸モノアリル、マレイン酸モノフェニル、フマル酸モノメチル、フマル酸モノエチル、フマル酸モノブチル、フマル酸モノフェニルなどのようなα−、β−不飽和ジカルボン酸のモノエステル類；ｎ−ブテニルコハク酸モノブチル、ｎ−オクテニルコハク酸モノメチル、ｎ−ブテニルマロン酸モノエチル、ｎ−ドデセニルグルタル酸モノメチル、ｎ−ブテニルアジピン酸モノブチルなどのようなアルケニルジカルボン酸のモノエステル類；フタル酸モノメチルエステル、フタル酸モノエチルエステル、フタル酸モノブチルエステルなどのような芳香族ジカルボン酸のモノエステル類；例えば、塩化ビニル、酢酸ビニル、安息香酸ビニル等のようなビニルエステル類、例えばエチレン、プロピレン、ブチレン等のようなエチレン系オレフィン類；例えば、ビニルメチルケトン、ビニルヘキシルケトン等のようなビニルケトン類；例えば、ビニルメチルエーテル、ビニルエチルエーテル、ビニルイソブチルエーテル等のようなビニルエーテル類；等のビニル単量体が単独もしくは組み合わせて用いられる。
【００７０】
ここで架橋剤としては、主として２個以上の重合可能な二重結合を有する化合物が用いられ、例えば、ジビニルベンゼン、ジビニルナフタレン等のような芳香族ジビニル化合物、；例えば、エチレングリコールジアクリレート、エチレングリコールジメタクリレート、１，３−ブタンジオールジメタクリレート等のような二重結合を２個有するカルボン酸エステル；ジビニルアニリン、ジビニルエーテル、ジビニルスルフィド、ジビニルスルホン等のジビニル化合物、及び３個以上のビニル基を有する化合物が単独もしくは混合物として使用できる。
【００７１】
本発明のトナーはトナー中に磁性体が含有されている磁性トナーの場合に、特に効果が大きい。
【００７２】
本発明のトナーに含有させる磁性体としては、強磁性の元素を含む合金又は化合物の粉末が好ましい。例えば、マグネタイト、マグヘマイト、フェライト等、鉄、コバルト、ニッケル、マンガン、亜鉛等の合金や化合物、その他の強磁性合金等、従来より磁性材料として知られているもの等を挙げることができる。
【００７３】
磁性粉の窒素ガス吸着法によるＢＥＴ比表面積としては、１〜４０ｍ^２／ｇ、さらには２〜３０ｍ^２／ｇのものが好ましい。
【００７４】
磁性粉の平均粒径としては、０．０５〜ｌμｍ、好ましくは０．１〜０．６μｍのものが好ましい。
【００７５】
また、磁性体はトナー中に結着樹脂１００質量部に対して、６０質量部〜２００質量部、さらに好ましくは８０質量部〜１５０質量部含有させることが好ましい。
【００７６】
また、本発明のトナーにおいては、形状がほぼ球形の磁性体を含有する場合において、特に好ましい。その製造における溶融混練工程においてバインダー樹脂中の磁性体の分散の状態が磁性体の形状がほぼ球形以外のものを用いた場合とは異なり、ある特異な表面状態がさらに好ましい形態になり、本発明の微粒子の「再転写」防止の効果がさらに働きやすくするものと考えている。磁性体の形状が「ほぼ球形」とは、磁性体の電子顕微鏡写真を用いて、それぞれの粒子（１００個以上を測定）の長径と短径の比（長径／短径）の平均が１．０〜１．２のものをさす。
【００７７】
本発明のトナーには荷電制御剤をトナー粒子に配合（内添）、又はトナー粒子と混合（外添）して用いることができ好ましい。荷電制御剤によって、現像システムに応じた最適の荷電量コントロールが可能となり、特に本発明では粒度分布と荷電量とのバランスを更に安定したものとすることが可能である。トナーを負荷電性に制御するものとして、例えば、下記物質がある。
【００７８】
例えば有機金属錯体、キレート化合物が有効であり、モノアゾ金属錯体、アセチルアセトン金属錯体、芳香族ハイドロキシカルボン酸、芳香族ダイカルボン酸系の金属錯体がある。他には、芳香族ハイドロキシカルボン酸、芳香族モノ及びポリカルボン酸及びその金属塩、無水物、エステル類、ビスフェノール等のフェノール誘導体類等がある。
【００７９】
また、本発明のトナーでは、トナーに流動性を付加する目的で、現像剤中に第２の無機微粉体が外添されている形態が好ましい。本発明５では、第２の無機微粉体の平均粒径を０．０３μｍ以下とする。
【００８０】
第２の無機微粉体は現像剤とヘンシェルミキサー等の混合器により攪拌、混合することにより含有される形態が好ましい。
【００８１】
本発明に用いられる第２無機微粉体としては、ケイ酸微粉体、酸化チタン、酸化アルミニウム等の無機微粉体が好ましく、特にケイ酸微粉体が好ましい。例えば、かかるケイ酸微粉体はケイ素ハロゲン化物の蒸気相酸化により生成されたいわゆる乾式法又はヒュームドシリカと称される乾式シリカ、及び水ガラス等から製造されるいわゆる湿式シリカの両者が使用可能であるが、表面及びシリカ微粉体の内部にあるシラノール基が少なく、またＮａ_２Ｏ、ＳＯ_３ ^２−等の製造残滓の少ない乾式シリカの方が好ましい。また乾式シリカにおいては、製造工程において例えば、塩化アルミニウム、塩化チタン等、他の金属ハロゲン化合物をケイ素ハロゲン化合物と共に用いることによって、シリカと他の金属酸化物の複合微粉体を得ることも可能でありそれらも包含する。
【００８２】
また表面を有機化合物により予め疎水化したものを用いてもよい。このような有機処理方法としては、前記無機微粉体と反応あるいは物理吸着するシランカップリング剤、チタンカップリング剤等の有機金属化合物で処理する方法；もしくはシランカップリング剤で処理した後、あるいはシランカップリング剤で処理すると同時にシリコーンオイルの如き有機ケイ素化合物で処理する方法が挙げられる。
【００８３】
本発明に用いられる第２の無機微粉体はＢＥＴ法で測定した窒素吸着による比表面積が３０ｍ^２／ｇ以上、特に５０〜４００ｍ^２／ｇの範囲のものが好ましい。
【００８４】
トナーの重量平均粒径は１０．０μｍ（好ましくは８．０μｍ）以下であることが好ましい。トナーの重量平均粒径は１０．０μｍ以下であるとき、「再転写」防止の効果がさらに高まる。トナーの重量平均粒径は１０．０μｍ以下であるとき、転写前の静電荷潜像担持体或いは中間転写体上のトナーの帯電量がさらに高くなるためと考えられる。
【００８５】
また、本発明のトナーの製造方法としては、以下のような方法が挙げられる。本発明に係るトナーを製造するにあたっては、上述したような構成材料をヘンシェルミキサー、ボールミル、Ｖ型ミキサー他の混合器を用いた混合工程、熱ロールニーダー、エクストルーダーのごとき熱混練機を用いた混練工程、混練物を冷却固化後、ジェットミル等の粉砕機を用いた粉砕工程、上記工程を少なくとも有する製造工程を経て製造されることが好ましい。さらに必要により、粉砕物の分級工程を経ることも好ましい。
【００８６】
これらの中でも、その製造工程に少なくとも結着樹脂とその他組成物を溶融混練する工程とそれを微粉砕する粉砕工程とを有する製造方法が特に好ましい。
【００８７】
溶融混練工程において、示差熱分析における吸熱ピークが１２０℃以下にある場合、結着樹脂中の磁性体，荷電制御剤の分散状態が本発明にとって好ましい状態になり、それを粉砕することにより、そのある特異な状態がそのままトナー表面に露出し、本発明のトナーの「再転写」防止の効果を発現するためである。
【００８８】
本発明において、形状係数を示すＳＦ−１、ＳＦ−２とは、例えば日立製作所製ＦＥ−ＳＥＭ（Ｓ−８００）を用い、１０００倍に拡大した２μｍ以上のトナー像を１００個無作為にサンプリングし、その画像情報はインターフェースを介して、例えばニコレ社製画像解析装置（ＬｕｚｅｘＩＩＩ）に導入し解析を行い、下式より算出し得られた値を形状係数ＳＦ−１、ＳＦ−２と定義する。
【００８９】
【数１】

【００９０】
（式中、ＭＸＬＮＧは粒子の絶対最大長、ＰＥＲＩＭＥは粒子の周囲長、ＡＲＥＡは粒子の投影面積を示す。）
【００９１】
形状係数ＳＦ−１はトナー粒子の丸さの度合いを示し、形状係数ＳＦ−２はトナー粒子の凹凸の度合いを示している。
【００９２】
本発明に係わる示差熱分析における吸熱ピークは、高精度の内熱式入力補償型の示差走査熱量計で測定する。たとえば、パーキンエルマー社製のＤＳＣ−７が使用できる。測定方法は、ＡＳＴＭＤ３４１８−８２に準じて行う。本発明に用いられるＤＳＣ曲線は、１回昇温させ前履歴をとった後、温度速度１０℃／ｍｉｎ、温度０〜２００℃の範囲で降温、昇温させたときに測定されるＤＳＣ曲線を用いる。吸熱ピーク温度とは、ＤＳＣ曲線において、プラスの方向のピーク温度のことであり、即ち、ピーク曲線の微分値が正から負にかわる際の０になる点を言う。
【００９３】
本発明のトナーの重量平均粒径の測定はコールターカウンターＴＡ−ＩＩ型あるいはコールターマルチサイザー（コールター社製）を用いる。電解液は１級塩化ナトリウムを用いて１％ＮａＣｌ水溶液を調製する。たとえば、ＩＳＯＴＯＮＲ−ＩＩ（コールターサイエンティフィックジャパン社製）が使用できる。測定法としては、前記電解水溶液１００〜１５０ｍｌ中に分散剤として界面活性剤、好ましくはアルキルベンゼンスルフォン酸塩を０．１〜５ｍｌ加え、更に測定試料を２〜２０ｍｇ加える。試料を懸濁した電解液は超音波分散器で約１〜３分間分散処理を行ない前記測定装置によリアパーチャーとして１００μｍアパーチャーを用いて、２μｍ以上のトナーの体積、個数を測定して体積分布と個数分布とを算出した。それから、本発明に係る体積分布から求めた重量基準の重量平均粒径Ｄ４（各チャンネルの中央値をチャンネル毎の代表値とする）を求めた。
【００９４】
本発明の微粒子の帯電量の測定方法としては、温度：２３℃、湿度：６０％のの環境下で、キャリアとしてＥＦＶ２００／３００（パウダーデック社製）を用い、キャリア１０．０ｇと微粒子０．２ｇを容量が５０ｍｌのポリエチレン製の容器に入れ、手で９０回震盪する。次いで、図１に示すような底に５００メッシュのスクリーン３のある金属製の測定容器２に前記混合物を約１ｇを入れ、金属製のフタ４をする。このときの測定容器２全体の重量を測りＷ１（ｇ）とする。次に吸引機（測定容器２と接する部分は絶縁体）に置き、吸引口７から圧力２４５０Ｐａ（２５０ｍｍＡｑ）で吸引し、この状態で２分間吸引を行い微粒子を吸引除去する。このときの電位計９の電位をＶ（ボルト）とする。ここで、８はコンデンサーであり容量をＣ（ｍＦ）とする。吸引後の測定容器２全体の重量を測定しそれをＷ２（ｇ）とする。微粒子の帯電量Ｔ（ｍＣ／ｋｇ）は
帯電量Ｔ（ｍＣ／ｋｇ）＝Ｃ×Ｖ／（Ｗ１−Ｗ２）
の上記計算式により求める。
【００９５】
【実施例】
以下、本発明を実施例により具体的に説明するが、これは本発明を何ら限定するものではない。
【００９６】

上記材料を予備混合した後に、１３０℃に設定した二軸混練押し出し機によって溶融混練を行なった。混練物を冷却後、粗粉砕をしジェット気流を用いた粉砕機によって微粉砕をし、さらに風力分級機を用いて分級した。さらに、機械的衝撃力により表面処理し黒色粉体（トナー粒子）Ａを得た。
【００９７】
上記トナー粒子Ａ：１００質量部に対して、金属酸化物微粒子（微粒子１）として酸化チタン微粒子（結晶形：ルチル型，平均粒径：０．３μｍ、帯電量：−２．８ｍＣ／ｋｇ）：０．５質量部、ヘキサメチルジシラザン／ジメチルシリコーンオイル処理乾式シリカ：１．２質量部とをヘンシェルミキサー１０Ｂにて３２００ｒｐｍで２分間攪拌混合しトナーを得た。
【００９８】
得られたトナーの重量平均粒径は６．９μｍ、ＳＦ−１は１４４、ＳＦ−２は１２６であった。また、示差熱分析における吸熱ピークは１０２℃にあった。
【００９９】
また、電子顕微鏡でトナー表面を観察したところ、微粒子１はトナー粒子表面にそのままの形状で付着した状態で、表面に埋め込まれてはいなかった。
【０１００】
（実施例２〜６及び比較例１〜４）
実施例１において添加する微粒子を、表１に示す微粒子２〜７及び微粒子９〜１１にする以外は、実施例１と同様にして表６に示すトナーを得た。
【０１０１】
（実施例７，８）
実施例１において添加する微粒子１の添加量を表６に示す量にする以外は実施例１と同様にして表６に示すトナーを得た。
【０１０２】
（実施例９〜１５）
実施例１において添加した低分子量ポリエチレンのかわりに表５に示した物質を添加する以外は実施例１と同様にしてトナー粒子Ｂ〜Ｈを得、それ以外は実施例１と同様にして表６に示すトナーを得た。
【０１０３】
（比較例５及び実施例１６，１７）
実施例１において行った機械衝撃処理をしない、及び、機械衝撃処理の条件を調節することにより、表５に示した形状に調整した以外は実施例１と同様にしてトナー粒子Ｉ〜Ｋを得、それ以外は実施例１と同様にして表６に示すトナーを得た。
【０１０４】
（実施例１８〜２１及び比較例６）
スチレン−アクリル酸ブチル共重合体１００質量部
マグネタイト（形状：球形、平均粒径：０．２μｍ）８０質量部
トリフェニルメタン系染料（正帯電性制御剤）２質量部
低分子量ポリエチレン（示差熱分析吸熱ピーク：１０２℃、
Ｍｗ／Ｍｎ：１．３）４質量部
上記材料を予備混合した後に、１３０℃に設定した二軸混練押し出し機によって溶融混練を行なった。混練物を冷却後、粗粉砕をしジェット気流を用いた粉砕機によって微粉砕をし、さらに風力分級機を用いて分級をした。
【０１０５】
さらに、機械的衝撃力により表面処理し黒色粉体（トナー粒子）Ｌを得た。
【０１０６】
上記トナー粒子Ｌ：１００質量部に対して、微粉体１，３，４，６，８それぞれ０．５質量部と、アミノ変性シリコーンオイル処理乾式シリカ：０．８質量部とをヘンシェルミキサー１０Ｂにて３２００ｒｐｍで２分間攪拌混合しトナーを得た。
【０１０７】
得られたトナーの重量平均粒径は７．６μｍ、ＳＦ−１は１４６、ＳＦ−２は１２４、比Ｂ／Ａは０．５２であった。また、示差熱分析における吸熱ピークは１０２℃にあった。
【０１０８】
（実施例２２〜２６）
実施例１において添加する微粒子を、表２に示すチタン酸金属微粒子あるいはケイ酸金属微粒子１２〜１６にする以外は、実施例１と同様にしてトナーを得た。
【０１０９】
（実施例２７，２８）
実施例２５において添加する微粒子１５の添加量を表７に示す量にする以外は、実施例２５と同様にしてトナーを得た。
【０１１０】
（実施例２９〜３５）
表５に示したトナー粒子Ｂ〜Ｈに微粒子１５を添加する以外は実施例１と同様にして表７に示すトナーを得た。
【０１１１】
（実施例３６，３７）
表５に示したトナー粒子Ｊ，Ｋに微粒子１５を添加する以外は実施例１と同様にして表７に示すトナーを得た。
【０１１２】
（実施例３８）
実施例１８で用いた微粒子のかわりに微粒子１５を用いる以外は、実施例１８と同様にしてトナーを得た。
【０１１３】
（実施例３９〜４１）
実施例１において添加する微粒子を、表３に示す金属炭化物微粒子１７〜１９にする以外は、実施例１と同様にしてトナーを得た。
【０１１４】
（実施例４２，４３）
実施例３９において添加する微粒子１７の添加量を表８に示す量にする以外は、実施例３９と同様にしてトナーを得た。
【０１１５】
（実施例４４〜５０）
表５に示したトナー粒子Ｂ〜Ｈに微粒子１７を添加する以外は実施例１と同様にして表８に示すトナーを得た。
【０１１６】
（比較例７及び実施例５１，５２）
表５に示したトナー粒子Ｉ〜Ｋに微粒子１７を添加する以外は実施例１と同様にして表８に示すトナーを得た。
【０１１７】
（実施例５３）
実施例１８で用いた微粒子のかわりに微粒子１７を用いる以外は、実施例１８と同様にしてトナーを得た。
【０１１８】
（実施例５４〜５６）
実施例１において添加する微粒子を、表４に示す金属炭酸塩微粒子２０〜２２にする以外は、実施例１と同様にしてトナーを得た。
【０１１９】
（実施例５７，５８）
実施例５４において添加する微粒子２０の添加量を表９に示す量にする以外は、実施例５４と同様にしてトナーを得た。
【０１２０】
（実施例５９〜６５）
表５に示したトナー粒子Ｂ〜Ｈに微粒子２０を添加する以外は実施例１と同様にして表９に示すトナーを得た。
【０１２１】
（比較例８及び実施例６６，６７）
表５に示したトナー粒子Ｉ〜Ｋに微粒子２０を添加する以外は実施例１と同様にして表９に示すトナーを得た。
【０１２２】
（実施例６８）
実施例１８で用いた微粒子のかわりに微粒子２０を用いる以外は、実施例１８と同様にしてトナーを得た。
【０１２３】

上記材料を予備混合した後に、１３０℃に設定した二軸混練押し出し機によって溶融混練を行なった。混練物を冷却後、粗粉砕をしジェット気流を用いた粉砕機によって微粉砕をし、さらに風力分級機を用いて分級し、黒色粉体（トナー粒子）Ｍを得た。
【０１２４】
上記トナー粒子Ｍ：１００質量部に対して、ヘキサメチルジシラザン／ジメチルシリコーンオイル処理乾式シリカ：０．４質量部をヘンシェルミキサー１０Ｂにて３２００ｒｐｍで２分間攪拌混合しトナーを得た。
【０１２５】
得られたトナーの重量平均粒径は１１．３μｍ、ＳＦ−１は１６０、ＳＦ−２は１５４であった。また、示差熱分析における吸熱ピークは１４５℃にあった。
【０１２６】
＜評価＞
上記の実施例及び比較例のトナーをそれぞれ下記の方法で評価をした。その結果は表６〜１０に示した。
【０１２７】
１）転写性の評価
キヤノン製レーザービームプリンターＬＢＰ−１２６０を改造し可変の転写バイアス電源を取付けた装置を用い、２３℃／６０％ＲＨの環境でベタ黒画像を現像し、７５ｇ／ｍ^２の転写紙上に転写させ、感光体上に残った転写残画像を透明なポリエステル製粘着テープではくりさせ白紙上に貼り、その反射濃度をマクベス反射濃度計にて測定し、標準としてテープのみを白紙上に貼った部分の濃度をそこから差し引いた値をもって評価した。転写電圧は１．０〜３．０ｋＶまで０．５ｋＶ刻みで評価した。
【０１２８】
２）画像濃度／カブリの評価
キヤノン製レーザービームプリンターＬＢＰ−１２６０とキヤノン製複写機ＰＣ３３０を用いて、３２℃／８０％の環境にて１，０００枚画出しした後に２日間放置した後、ベタ黒画像をプリントし、その画像濃度をマクベス反射濃度計にて測定し評価した。
【０１２９】
また、同時にベタ白画像をプリントし、リフレクトメーター（東京電色（株）製）により測定した未使用の転写紙上の白色度とベタ白をプリントした後の転写紙の白色度の差からカブリを評価した。
【０１３０】
【表１】

【０１３１】
【表２】

【０１３２】
【表３】

【０１３３】
【表４】

【０１３４】
【表５】

【０１３５】
【表６】

【０１３６】
【表７】

【０１３７】
【表８】

【０１３８】
【表９】

【０１３９】
【表１０】

【０１４０】
（シリコーンオイルを含有したケイ素の酸化物微粒子の製造例１）
乾式法で合成されたシリカ微粉体（比表面積：５２ｍ^２／ｇ）を８０℃に加熱された密閉型ヘンシェルミキサー中に入れ、該シリカ微粉体１００質量部に対して、１０質量部になるようにキシレンで希釈したジメチルシリコーンオイル（２５℃における粘度：５０ｃＳｔ）を噴霧しながら高速で撹拌し、その後、溶媒を揮発させ、シリコーンオイルを含有したシリカ（ケイ素酸化物）微粒子ａを得た。
【０１４１】
（シリコーンオイルを含有したケイ素の酸化物微粒子の製造例２）
乾式法で合成されたシリカ微粉体（比表面積：１５ｍ^２／ｇ）を８０℃に加熱された密閉型ヘンシェルミキサー中に入れ、該シリカ微粉体１００質量部に対して、８．５質量部になるようにキシレンで希釈したジメチルシリコーンオイル（２５℃における粘度：５０ｃＳｔ）と、１．５質量部になるようにキシレンで希釈したアミノ変性シリコーンオイル（２５℃における粘度：５０ｃＳｔ）を噴霧しながら高速で撹拌し、その後、溶媒を揮発させ、シリコーンオイルを含有したシリカ（ケイ素酸化物）微粒子ｂを得た。
【０１４２】
（シリコーンオイルを含有したケイ素の酸化物微粒子の製造例３）
もとのシリカ微粉体として、ヘキサメチルジシラザンで表面処理されたもの（比表面積：４７ｍ^２／ｇ）を用いる以外は、製造例１と同様にしてシリコーンオイルを含有したシリカ（ケイ素酸化物）微粒子ｃを得た。
【０１４３】
（シリコーンオイルを含有したケイ素の酸化物微粒子の製造例４）
もとのシリカ微粉体として、比表面積が１００ｍ^２／ｇであるものを用いる以外は、製造例１と同様にしてシリコーンオイルを含有したシリカ（ケイ素酸化物）微粒子ｄを得た。
【０１４４】
（シリコーンオイルを含有したケイ素の酸化物微粒子の製造例５）
乾式法で合成されたシリカ微粉体（比表面積：２００ｍ^２／ｇ）を８０℃に加熱された密閉型ヘンシェルミキサー中に入れ、該シリカ微粉体１００質量部に対して、１００質量部になるようにキシレンで希釈したジメチルシリコーンオイル（２５℃における粘度：１００００ｃＳｔ）を噴霧しながら高速で撹拌し、その後、溶媒を揮発させ、シリコーンオイルを含有したシリカ（ケイ素酸化物）微粒子ｅを得た。
【０１４５】
（シリコーンオイルを含有したケイ素の酸化物微粒子の製造例６）
乾式法で合成されたシリカ微粉体（比表面積：２００ｍ^２／ｇ）を８０℃に加熱された密閉型ヘンシェルミキサー中に入れ、該シリカ微粉体１００質量部に対して、８５質量部になるようにキシレンで希釈したジメチルシリコーンオイル（２５℃における粘度：１００００ｃＳｔ）と、１５質量部になるようきキシレンで希釈したアミノ変性シリコーンオイルを噴霧しながら高速で撹拌し、その後、溶媒を揮発させ、シリコーンオイルを含有したシリカ（ケイ素酸化物）微粒子ｆを得た。
【０１４６】
（シリコーンオイルを含有したケイ素の複合酸化物微粒子の製造例７）
アルミ元素を１％含有したケイ素−アルミニウム複合酸化物（比表面積：４５ｍ^２／ｇ）を８０℃に加熱された密閉型ヘンシェルミキサー中に入れ、該シリカ微粉体１００質量部に対して、１０質量部になるようにキシレンで希釈したジメチルシリコーンオイル（２５℃における粘度：５０ｃＳｔ）を噴霧しながら高速で撹拌し、その後、溶媒を揮発させ、シリコーンオイルを含有したケイ素−アルミニウム複合酸化物（ケイ素複合酸化物）微粒子ｇを得た。
【０１４７】
上記の得られたケイ素酸化物又はケイ素複合酸化物の微粒子ａ〜ｇの各種物性値を表１１に示す。
【０１４８】
【表１１】

【０１４９】

上記材料を予備混合した後に、１３０℃に設定した二軸混練押し出し機によって溶融混練を行なった。混練物を冷却後、粗粉砕をしジェット気流を用いた粉砕機によって微粉砕をし、さらに風力分級機を用いて分級した。さらに、機械的衝撃力により表面処理し黒色粉体（トナー粒子）Ｎを得た。
【０１５０】
上記トナー粒子Ｎ：１００質量部に対して、ジメチルシリコーンオイルで表面処理された微粒子ａ：０．５質量部、ヘキサメチルジシラザン／ジメチルシリコーンオイル処理乾式シリカ（平均粒径：０．０１μｍ）：１．２質量部とをヘンシェルミキサー１０Ｂにて３２００ｒｐｍで２分間攪拌混合しトナーを得た。
【０１５１】
得られたトナーの重量平均粒径は６．９μｍ、ＳＦ−１は１４４、ＳＦ−２は１２６であった。また、示差熱分析における吸熱ピークは１０２℃にあった。
【０１５２】
また、電子顕微鏡でトナー表面を観察したところ、ジメチルシリコーンオイルで表面処理された微粒子ａの平均粒径は０．０４μｍで、トナー粒子表面に付着した状態で、トナー表面に埋め込まれてはいなかった。
【０１５３】
（実施例７０〜７４及び比較例１０）
実施例６９において添加する微粒子を、表１１に示す微粒子ｂ〜ｇを用いることを除いては、実施例６９と同様にしてトナーを得た。
【０１５４】
（実施例７５〜７７）
実施例６９において添加する微粒子ａの添加量を表１３に示す量にする以外は実施例６９と同様にしてトナーを得た。
【０１５５】
（実施例７８〜８４）
実施例６９において添加した低分子量ポリエチレンのかわりに表１２に示した物質を添加する以外は実施例６９と同様にしてトナー粒子Ｏ〜Ｕを得、それ以外は実施例６９と同様にしてトナーを得た。
【０１５６】
（実施例８５，８６）
実施例６９において行った機械衝撃処理の条件を調節することにより、表１２に示した形状に調整した以外は実施例６９と同様にしてトナー粒子Ｖ及びＷを得、それ以外は実施例６９と同様にしてトナーを得た。
【０１５７】

上記材料を予備混合した後に、１３０℃に設定した二軸混練押し出し機によって溶融混練を行なった。混練物を冷却後、粗粉砕をしジェット気流を用いた粉砕機によって微粉砕をし、さらに風力分級機を用いて分級をし表１２に示す黒色微粉体（トナー粒子）Ｘを得た。また示差熱分析における吸熱ピークは１４５℃にあった。
【０１５８】
上記トナー粒子Ｘ：１００質量部に対して、ヘキサメチルジシラザン／ジメチルシリコーンオイル処理乾式シリカ（平均粒径０．０１μｍ）：０．４質量部をヘンシェルミキサー１０Ｂにて３２００ｒｐｍで２分間攪拌混合しトナーを得た。
【０１５９】
得られたトナーの重量平均粒径は１１．３μｍ、ＳＦ−１は１６０、ＳＦ−２は１５４であった。
【０１６０】
＜評価＞
上記の実施例６９〜８６及び比較例１０，１１のトナーをそれぞれ下記の方法で評価をした。その結果を表１３及び１４に示した。
【０１６１】
１）転写性の評価
実施例１〜６８と同様に行った。
【０１６２】
２）画像濃度／カブリの評価
画出し枚数を２，０００枚にした他は、実施例１〜６８と同様に行った。
【０１６３】
【表１２】

【０１６４】
【表１３】

【０１６５】
【表１４】

【０１６６】
【発明の効果】
本発明によれば、高い転写電流条件においても「再転写」を起こさず、画像濃度の高い良好な画質の画像を得ることができる。
【図面の簡単な説明】
【図１】本発明トナーの帯電量を測定する装置の説明図である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a toner used in a recording method using an electrophotographic method, an electrostatic recording method, a magnetic recording method, or the like. More specifically, the present invention relates to a toner used in a copying machine, a printer, and a facsimile, which forms an image by forming a toner image on an electrostatic latent image carrier in advance and transferring the image on a transfer material.
[0002]
[Prior art]
Conventionally, a number of methods are known as electrophotography. Generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means. And a toner image is transferred to a transfer material such as paper if necessary, and then the toner image is fixed on the transfer material by heat / pressure to obtain a final image.
[0003]
In recent years, the demand for color copying machines, printers, and fax machines using electrophotography has been increasing. Generally, it is difficult to use a magnetic toner containing a magnetic material because of the color of the color toner, so a non-magnetic toner is used. When a magnetic toner is used for the black toner and a non-magnetic toner is used for the color toner, the optimum transfer current value of the non-magnetic toner tends to be higher than the optimum transfer current value of the magnetic toner. When the transfer condition of the device body is adjusted to the non-magnetic toner, a phenomenon called “re-transfer” occurs in which the magnetic toner once transferred onto the transfer material returns to the latent image carrier, resulting in a black image. Causes a decrease in concentration.
[0004]
In recent years, further diversification of paper materials has been progressing, and it is required that copiers, printers, and fax machines using electrophotography can cope with such versatile paper materials. However, the optimum transfer conditions differ depending on the paper material as the transfer material. For example, in the case of a thick paper or an OHT film, the optimum transfer current value becomes a high value. On the other hand, for thin paper, the optimum transfer current value is low, and if the transfer conditions of the apparatus main body are optimized for thick paper or an OHT film, the “retransfer” phenomenon also occurs.
[0005]
JP-A-2-66559, JP-A-2-87159, JP-A-2-146557, JP-A-2-167566, JP-A-5-61251, etc. apply a mechanical impact treatment to the toner. It has been proposed that the transfer rate can be improved thereby.
[0006]
The proposed methods certainly improve the transfer rate when the transfer condition is adjusted to the best transfer efficiency for the toner, but the transfer efficiency when the transfer current value is set higher than that is almost improved. It is not effective in improving "retransfer".
[0007]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a toner for developing an electrostatic image, which solves the above-mentioned problems of the prior art.
[0008]
That is, an object of the present invention is to provide a toner for developing an electrostatic image capable of obtaining a high image density without causing "retransfer" under a wide range of transfer current conditions (particularly under a high transfer current condition).
[0009]
It is a further object of the present invention to provide a toner for developing an electrostatic image capable of obtaining an image with high image density and good image quality.
[0010]
[Means for Solving the Problems]
The present invention relates to a toner for developing an electrostatic image having toner particles containing at least a binder resin and a colorant and inorganic fine particles externally added to the toner particles,
A step of melting and kneading the toner particles with at least a binder resin and a colorant;,The process of crushing itAnd applying a mechanical impact force after the crushing process to perform spheroidizing treatmentManufactured at least through
The inorganic fine particles have an average particle size of 0.05 to 2.0 μm and have the following formula (1)
M_xO_y            ... (1)
(In the formula, M represents an aluminum element, a titanium element, a zinc element or a zirconium element, O represents an oxygen element, and x and y represent positive numbers other than 0.)
Having metal oxide fine particles represented by
The toner has one or more endothermic peaks at 120 ° C. or lower in differential thermal analysis,
The toner has a shape factor SF-1 value measured by an image analyzer within a range of 110 to 180, a shape factor SF-2 value within a range of 110 to 140, and a value of SF-2. The present invention relates to a toner for developing an electrostatic image, wherein a ratio B / A of a value B obtained by subtracting 100 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less. Hereinafter, “Invention 1” particularly refers to a toner having this configuration.
[0011]
Further, the present invention provides a toner for electrostatic image development having toner particles containing at least a binder resin and a colorant and inorganic fine particles externally added to the toner particles,
A step of melting and kneading the toner particles with at least a binder resin and a colorant;,The process of crushing itAnd applying a mechanical impact force after the crushing process to perform spheroidizing treatmentManufactured at least through
The inorganic fine particles have the following formula (2) or (3) having an average particle size of 0.1 to 3.0 μm.
M_xTi_yO_z            ... (2)
M_xSi_yO_z            ... (3)
(In the formula, M indicates a metal element, Ti indicates a titanium element, Si indicates a silicon element, O indicates an oxygen element, and x and y indicate non-zero positive numbers.)
Having composite metal oxide fine particles represented by
The toner has one or more endothermic peaks at 120 ° C. or lower in differential thermal analysis,
The toner has a shape factor SF-1 value measured by an image analyzer within a range of 110 to 180, a shape factor SF-2 value within a range of 110 to 140, and a value of SF-2. The present invention relates to a toner for developing an electrostatic image, wherein a ratio B / A of a value B obtained by subtracting 100 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less. Hereinafter, the “present invention 2” particularly means a toner having this configuration.
[0012]
Further, the present invention provides a toner for electrostatic image development having toner particles containing at least a binder resin and a colorant and inorganic fine particles externally added to the toner particles,
A step of melting and kneading the toner particles with at least a binder resin and a colorant;,The process of crushing itAnd applying a mechanical impact force after the crushing process to perform spheroidizing treatmentManufactured at least through
The inorganic fine particles have an average particle diameter of 0.05 to 2.0 μm inorganic carbide fine particles,
The toner has one or more endothermic peaks at 120 ° C. or lower in differential thermal analysis,
The toner has a shape factor SF-1 value measured by an image analyzer within a range of 110 to 180, a shape factor SF-2 value within a range of 110 to 140, and a value of SF-2. The present invention relates to a toner for developing an electrostatic image, wherein a ratio B / A of a value B obtained by subtracting 100 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less. Hereinafter, the “present invention 3” particularly refers to a toner having this configuration.
[0013]
Further, the present invention provides a toner for electrostatic image development having toner particles containing at least a binder resin and a colorant and inorganic fine particles externally added to the toner particles,
A step of melting and kneading the toner particles with at least a binder resin and a colorant;,The process of crushing itAnd applying a mechanical impact force after the crushing process to perform spheroidizing treatmentManufactured at least through
The inorganic fine particles have metal carbonate fine particles having an average particle size of 0.05 to 2.0 μm,
The toner has one or more endothermic peaks at 120 ° C. or lower in differential thermal analysis,
The toner has a shape factor SF-1 value measured by an image analyzer within a range of 110 to 180, a shape factor SF-2 value within a range of 110 to 140, and a value of SF-2. The present invention relates to a toner for developing an electrostatic image, wherein a ratio B / A of a value B obtained by subtracting 100 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less. Hereinafter, the “present invention 4” particularly means a toner having this configuration.
[0014]
Further, the present invention provides a toner for developing an electrostatic image having toner particles containing at least a binder resin and a colorant and inorganic fine particles externally added to the toner particles.
A step of melting and kneading the toner particles with at least a binder resin and a colorant;,The process of crushing itAnd applying a mechanical impact force after the crushing process to perform spheroidizing treatmentManufactured at least through
The inorganic fine particles have silicon oxide fine particles or silicon composite oxide fine particles containing silicone oil and having an average particle size of 0.03 to 50 μm,
The toner has one or more endothermic peaks at 120 ° C. or lower in differential thermal analysis,
The toner has a shape factor SF-1 value measured by an image analyzer within a range of 110 to 180, a shape factor SF-2 value within a range of 110 to 140, and a value of SF-2. The present invention relates to a toner for developing an electrostatic image, wherein a ratio B / A of a value B obtained by subtracting 100 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less. Hereinafter, the “present invention 5” particularly means a toner having this configuration.
[0015]
The present inventors have studied for the purpose of solving "retransfer" and found that "retransfer" can be solved by increasing the charge amount of the toner before transfer.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
By externally adding the fine particles to the toner base particles and using a toner having one or more endothermic peaks at 120 ° C. or lower in the differential thermal analysis, the electrostatic latent image carrier or the intermediate transfer body before the transfer is used. The charge amount of the toner could be made higher than before, and "retransfer" could be prevented.
[0017]
At the time of development and transfer, the fine particles are separated from the toner matrix, and the fine particles impart a charge to the toner matrix itself, so that "retransfer" can be prevented because the amount of charge of the toner before transfer is increased.
[0018]
If the average particle diameter of the fine particles in the inventions 1, 3 and 4 is less than 0.05 μm, and if the average particle diameter of the fine particles in the invention 2 is less than 0.1 μm, the adhesion of the fine particles to the toner surface is too large, At the time of transfer, the toner is not sufficiently separated from the mother toner, and the amount of charge of the toner before transfer cannot be increased.
[0019]
When the average particle diameter of the fine particles exceeds 2.0 μm in the present inventions 1, 3 and 4, and the average particle diameter of the fine particles exceeds 3.0 μm in the present invention 2, the effect of increasing the tribo of the toner before transfer is small because the surface area of the fine particles is small. There is no effect of preventing "re-transfer". Further, aggregation of toner particles may occur with the fine particles as nuclei, which may cause an increase in fog.
[0020]
In addition, the toner of the present invention 5 contains silicon oxide fine particles or silicon composite oxide fine particles having a relatively large particle diameter containing silicone oil having a particle diameter of 0.03 to 50 μm (preferably 0.04 to 1 μm). When the particle size of the fine particles containing silicone oil is less than 0.03 μm, the fine particles containing silicone oil adhere too strongly to the toner surface, and the toner base material during development / transfer Separation from the toner does not sufficiently occur, and the amount of charge of the toner before transfer cannot be increased.
[0021]
If the particle size of the fine particles containing silicone oil exceeds 50 μm, the effect of preventing “retransfer” cannot be sufficiently obtained.
[0022]
The fine particles are used in a form externally added to the toner base. If the fine particles are in the state of being internally added to the toner matrix and in the state of being firmly fixed to the toner surface, the charge amount of the toner before transfer cannot be increased, and there is no effect in preventing “retransfer”.
[0023]
In the inventions 1 to 4, it is preferable that the fine particles have the same charge polarity as the toner to the iron powder carrier. When the charged polarity of the fine particles is the same as the charged polarity of the toner, the image density is higher and fog can be further suppressed.
[0024]
Further, in the present invention 1, 2, and 4, it is preferable that the fine particles have an absolute value of | 20 | μC / g or less, and more preferably | 10 | μC / g or less, in terms of absolute value. In the case of the inorganic carbide according to the third aspect of the present invention, the charge amount of the iron powder carrier with respect to the absolute value of the absolute value is preferably | 30 | μC / g or less, more preferably | 20 | μC / g or less. When the charge amount of the fine particles is in the above range, the image density is higher and fog can be further suppressed.
[0025]
In the inventions 1 to 4, the amount of the fine particles added to the toner is 0.01 to 3.0 parts by mass (more preferably 0.05 to 1.0 parts by mass) based on 100 parts by mass of the toner. Is preferred. In the fifth aspect of the invention, the amount is preferably 0.1 to 10 parts by mass (more preferably 0.1 to 2.0 parts by mass) based on 100 parts by mass of the toner.
[0026]
If the amount of the fine particles added to the toner falls below the lower limit, the effect of increasing the charge amount of the toner before transfer is insufficient, and the effect of preventing "retransfer" cannot be sufficiently obtained. If the amount of the fine particles added to the toner exceeds the upper limit, fogging is likely to occur.
[0027]
Next, the material of each fine particle according to the present invention 1 to 5 will be described in detail.
[0028]
Chemical Formula M Used for Toner of Present Invention 1_xO_yM is any one of aluminum, titanium, zinc, and zirconium in the fine particles of the compound represented by
[0029]
Further, among these, titanium oxide is more preferable. When titanium oxide fine particles are used, the image density is further increased and fog can be further suppressed.
[0030]
In particular, in the case of a titanium oxide having a rutile-type crystal form, the effect of preventing "retransfer" is further enhanced.
[0031]
Also, one type of M¹  _xO_yAnother M on the surface of the fine particles²  _xO_yIs attached or coated, or two or more types of M_xO_yMay be in a mixed crystal form. Further, the surface of the fine particles may be subjected to a hydrophobic treatment.
[0032]
M used in the toner of the present invention 2_xTi_yO_zExamples of M include elements such as strontium, barium, magnesium, and calcium. Also, M_xSi_yO_zExamples of M include elements such as strontium, barium, magnesium, and calcium.
[0033]
Among these, the case where M is strontium is particularly preferred because the effect of preventing "retransfer" is high.
[0034]
In addition, a form in which another substance is adhered or coated on the surface of one kind or a form in which two or more kinds are mixed crystals may be used. Further, the surface of the fine particles may be subjected to a hydrophobic treatment.
[0035]
Examples of the inorganic carbide used in the present invention 3 include carbides such as boron, silicon, titanium, vanadium, zirconium, molybdenum, and tungsten. Of these, carbides of boron or silicon are more preferred because of the effect of preventing "retransfer". Further, among these, silicon carbide is particularly preferable because the effect of preventing "retransfer" is further enhanced.
[0036]
Examples of the metal carbonate fine particles used in the present invention 4 include carbonates such as magnesium, calcium, strontium, and barium. Among them, strontium carbonate fine particles are more preferable because they have a higher effect of preventing "retransfer". It may be in the form of a bicarbonate. Further, the surface may be subjected to a hydrophobic treatment.
[0037]
Examples of the silicon oxide fine particles used in the present invention 5 include, for example, a so-called dry method produced by a vapor phase oxidation of a silicon halide or a dry silica called a fumed silica, and a so-called wet silica produced from water glass or the like. Can be used, but there are few silanol groups on the surface and inside the silica fine powder, and Na₂O, SO^3-Dry silica with less production residue such as is preferred. Further, as the silicon composite oxide fine particles, in the production process, for example, a composite oxide of silicon oxide and another metal oxide obtained by using another metal halide such as aluminum chloride and titanium chloride together with the silicon halide is used. Substance fine particles, which are also included in the present invention.
[0038]
When the silicon oxide or composite oxide fine particles do not contain silicone oil, the effect of preventing retransfer is hardly obtained. The interaction between the relatively strong surface of the silicon oxide or composite oxide and the silicone oil causes the silicone oil to have a certain high activity state, thereby increasing the charge amount of the toner developed on the photoreceptor. It is thought that it is possible.
[0039]
As the form of the silicone oil, in addition to the form of coating the surface of the fine particles, a form in which the fine particles take the form of an aggregate formed by granulating with the silicone oil is preferably used.
[0040]
When the silicone oil covers the surface of the fine particles, the BET specific surface area of the original fine particles is 100 m.²/ G or less, more preferably 70 m²/ G or less. When the fine particles are in the form of an aggregate formed by granulation with silicone oil, the BET specific surface area is 100 m.²/ G ~ 400m²/ G.
[0041]
Further, as the silicon oxide or composite oxide particles, those which have been made hydrophobic by a coupling agent or the like before containing silicone oil may be used.
[0042]
As a preferred viscosity of the silicone oil, when the silicone oil covers the surface of the fine particles, the viscosity at 25 ° C. is 0.5 to 10,000 centistokes, preferably 1 to 1,000 centistokes, more preferably 10 to 200 centistokes. Stokes ones are used. When the fine particles are in the form of an aggregate formed by granulation with silicone oil, those having a viscosity at 25 ° C. of 50 to 200,000 centistokes, preferably 500 to 150,000 centistokes are used.
[0043]
Preferred types of silicone oil include, for example, dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, fluorine-modified silicone oil, amino-modified silicone oil, and the like.
[0044]
As a method of treating the silicone oil, for example, silica fine powder treated with a silane coupling agent and silicone oil may be directly mixed using a mixer such as a Henschel mixer, or silicone A method of spraying oil may be used. Alternatively, a method of dissolving or dispersing a silicone oil in an appropriate solvent, adding a silica fine powder, mixing and removing the solvent may be employed.
[0045]
After the treatment, it is more preferable to heat the inorganic fine powder to 200 ° C. or higher (more preferably 250 ° C. or higher) in an inert gas to stabilize the surface coat.
[0046]
These toners of the present invention have one or more endothermic peaks in differential thermal analysis at 120 ° C. or lower (preferably 110 ° C. or lower).
[0047]
If the endothermic peak in the differential thermal analysis is not at 120 ° C. or lower, the effect of preventing “retransfer” by externally adding the fine particles of the present invention cannot be sufficiently obtained.
[0048]
The toner having an endothermic peak of 120 ° C. or lower in the differential thermal analysis is the same as the toner in which the dispersion state of the magnetic substance / charge control agent in the binder resin in the melt-kneading step in the production thereof does not have the endothermic peak of 120 ° C. or lower. Is presumed to be a different and unique state. It is considered that the specific state makes the effect of preventing the "retransfer" of the specific fine particles of the present invention easy to work.
[0049]
If at least one endothermic peak in the differential thermal analysis is at 120 ° C. or lower, the effect is obtained, and the endothermic peak may be at a place exceeding 120 ° C. However, it is preferable that the endothermic peak in the differential thermal analysis does not exist at 60 ° C. or lower (preferably 70 ° C. or lower). When the endothermic peak in the differential thermal analysis exists below 60 ° C., the image density tends to be low. Further, the storage stability tends to be unstable.
[0050]
As a means for forming an endothermic peak at 120 ° C. or lower in differential thermal analysis, a method in which a compound having an endothermic peak in differential thermal analysis at 120 ° C. or lower is preferably added to the toner.
[0051]
Examples of the substance having one or more endothermic peaks at 120 ° C. or lower in the differential thermal analysis include a resin and a wax.
[0052]
Examples of the resin include a crystalline polyester resin and a silicone resin.
[0053]
As the wax, paraffin wax, microcrystalline wax, petroleum wax such as petrolactam and its derivatives, montan wax and its derivatives, hydrocarbon wax and its derivatives by Fischer-Tropsch method, polyolefin wax represented by polyethylene and its derivatives, Natural waxes such as carnauba wax and candelilla wax and derivatives thereof, and the like. The derivatives also include oxides, block copolymers with vinyl monomers, and graft-modified products. Alcohols such as higher aliphatic alcohols; fatty acids such as stearic acid and palmitic acid or compounds thereof; acid amides, esters, ketones, hydrogenated castor oil and derivatives thereof, vegetable waxes, animal waxes, etc .; Any of the following can be used.
[0054]
Among them, when the compound having an endothermic peak at 120 ° C. or lower in the differential thermal analysis is a polyolefin or a hydrocarbon wax or a petroleum-based wax or a higher alcohol by a Fischer-Tropsch method, further, a polyolefin or a hydrocarbon by a Fischer-Tropsch method A wax or a petroleum wax is particularly preferred in the toner of the present invention.
[0055]
When the above specific compound is used, the effect of preventing “retransfer” is further enhanced.
[0056]
These compounds have relatively low polarities and are considered to stabilize the charge of the toner matrix. It is believed that this further facilitates the effect of preventing "retransfer" of the fine particles of the present invention.
[0057]
Among these, compounds having an endothermic peak at 120 ° C. or lower in differential thermal analysis are polyolefins, hydrocarbon waxes or petroleum waxes by Fischer-Tropsch method or higher alcohols, and their weight average molecular weights (Mw) by GPC measurement. When the ratio (Mw / Mn) of the number average molecular weight (Mn) is 1.0 to 2.0, the effect of preventing "retransfer" is further enhanced. By adding the wax having a sharp molecular weight distribution (Mw / Mn) of 1.0 to 2.0 to the toner, the magnetic material in the binder resin and charge control in the melt-kneading step in the production of the toner. It is considered that the state of dispersion of the agent and the like is more preferable for the present invention.
[0058]
The present invention1 toThe toner of No. 5 has a shape factor SF-1 value of 110 <SF-1 ≦ 180 (more preferably 120 <SF) measured with an image analyzer for toner particles in order to enhance the effect of preventing “retransfer”. −1 ≦ 160), the value of the shape factor SF-2 is 110 <SF−2 ≦ 140 (more preferably, 115 <SF−2 ≦ 140), and a value B obtained by subtracting 100 from the value of SF−2 The ratio B / A between the value of SF-1 and the value A obtained by subtracting 100 from the value of SF-1 needs to be 1.0 or less. The shape in the above range is a shape in which the toner surface is relatively smooth and has few irregularities. In the case of such a shape, it is considered that the fine particles externally added to the toner work more effectively, and the effect of preventing “retransfer” is enhanced.
[0059]
When SF-1 is 110 or less, when SF-2 is 110 or less, and when B / A is less than 1.0, it is difficult to clean transfer residual toner remaining on the latent image carrier, Cleaning failure is likely to occur. When SF-1 exceeds 180 and SF-2 exceeds 140, the effect of preventing "retransfer" cannot be sufficiently improved.
[0061]
The following method can be used to make the shape of the toner of the present invention within the above range.
[0062]
In the method of pulverization using a mechanical impact type pulverizer or the method of jet pulverization, a method of lowering the pulverization pressure than usual and increasing the number of circulations to perform pulverization is exemplified. In addition, a hot water bath method in which finely pulverized or further classified toner particles are dispersed in water and heated, a heat treatment method in which the toner particles are passed through a hot air flow, a mechanical impact method in which mechanical energy is applied and treated, and the like are exemplified. .
[0063]
Among these, a method of adding a treatment by a mechanical impact force is preferable. Examples of the process of applying a mechanical impact force include, for example, a method of applying a mechanical impact force to a toner by a mechanical impact type pulverizer such as a Kryptron system manufactured by Kawasaki Heavy Industries, Ltd. or a turbo mill manufactured by Turbo Industries, Ltd., and Hosokawa Micron. Like high-speed rotating blades, the toner is pressed against the inside of the casing by centrifugal force, as in devices such as Mechanofusion system manufactured by Nara Corporation and hybridization system manufactured by Nara Machinery Co., Ltd. There is a method of applying a mechanical impact force.
[0064]
When the treatment for applying a mechanical impact force is performed after the fine pulverizing step of the toner or after the classification step, the effect of preventing “retransfer” is further enhanced, which is particularly preferable. It is also considered that the mechanical impact treatment causes the toner surface to have a “certain unique surface state” in which the action of the fine particles of the present invention is more likely to work.
[0065]
Examples of the binder resin usable in the present invention include the following. In the case of the heat fixing toner, for example, polystyrene, poly-p-chlorostyrene, a homopolymer of styrene such as polyvinyltoluene and a substituted product thereof; a styrene-vinylnaphthalene copolymer, a styrene-acrylate copolymer, Styrene-methacrylic acid ester copolymer, styrene-maleic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-maleic acid copolymer, styrene-α-chloromethyl methacrylate Copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer Coalescence, styrene-acrylonitrile in Styrene copolymers such as copolymers; polyvinyl chloride, phenolic resin, natural modified phenolic resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide Resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, tempen resin, cumarone indene resin, petroleum resin and the like can be used.
[0066]
Among these, a styrene copolymer is particularly preferred because it further enhances the effect of preventing "retransfer".
[0067]
The styrenic copolymer has a relatively low polarity of its own main chain, and is considered to stabilize the charge of the toner matrix. It is believed that this further facilitates the effect of preventing "retransfer" of the fine particles of the present invention.
[0068]
Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, and methacryl. Acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, monocarboxylic acid having a double bond such as acrylamide, or a substitute thereof; acrylic acid, methacrylic acid, α -Acrylic acid such as ethylacrylic acid, crotonic acid and its α- or β-alkyl derivatives, fumaric acid, maleic acid, unsaturated dicarboxylic acids such as citraconic acid and its monoester derivatives, maleic anhydride, etc. Such monomers alone or in combination, can make the desired polymer by copolymerization with other monomers.
[0069]
Among these, it is particularly preferable to use a monoester derivative of an unsaturated dicarboxylic acid. More specifically, for example, monomethyl maleate, monoethyl maleate, monobutyl maleate, monooctyl maleate, monoallyl maleate, monophenyl maleate, monomethyl fumarate, monoethyl fumarate, monoethyl fumarate, monobutyl fumarate Monoesters of α-, β-unsaturated dicarboxylic acids such as monobutyl n-butenylsuccinate, monomethyl n-octenylsuccinate, monoethyl n-butenylmalonate, monomethyl n-dodecenylglutarate, n-butenyladipate Monoesters of alkenyldicarboxylic acids such as monobutyl; monoesters of aromatic dicarboxylic acids such as monomethyl phthalate, monoethyl phthalate, monobutyl phthalate; and the like, for example, vinyl chloride, vinegar Vinyl esters such as vinyl acrylate, vinyl benzoate, etc., for example, ethylene olefins such as ethylene, propylene, butylene, etc .; for example, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, etc .; for example, vinyl methyl ether And vinyl monomers such as vinyl ethyl ether and vinyl isobutyl ether; and the like.
[0070]
Here, as the cross-linking agent, compounds having two or more polymerizable double bonds are mainly used, for example, aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, etc .; for example, ethylene glycol diacrylate, ethylene Carboxylic acid esters having two double bonds such as glycol dimethacrylate and 1,3-butanediol dimethacrylate; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone, and three or more vinyl groups Can be used alone or as a mixture.
[0071]
The toner of the present invention is particularly effective when the toner contains a magnetic substance.
[0072]
As the magnetic substance contained in the toner of the present invention, an alloy or compound powder containing a ferromagnetic element is preferable. Examples of such materials include magnetite, maghemite, ferrite, and the like, and alloys and compounds such as iron, cobalt, nickel, manganese, and zinc, and other ferromagnetic alloys.
[0073]
The magnetic powder has a BET specific surface area of 1 to 40 m as measured by a nitrogen gas adsorption method.²/ G, and 2-30m²/ G is preferred.
[0074]
The average particle size of the magnetic powder is preferably 0.05 to 1 μm, and more preferably 0.1 to 0.6 μm.
[0075]
The magnetic material is preferably contained in the toner in an amount of 60 to 200 parts by mass, more preferably 80 to 150 parts by mass, based on 100 parts by mass of the binder resin.
[0076]
The toner of the present invention is particularly preferable when the toner contains a magnetic substance having a substantially spherical shape. In the melt-kneading step in the production, the state of dispersion of the magnetic substance in the binder resin is different from the case where the magnetic substance has a shape other than substantially spherical, and a specific surface state is more preferable. It is believed that the effect of preventing "retransfer" of the fine particles further works. When the shape of the magnetic material is “substantially spherical”, the average of the ratio of the major axis to the minor axis (major axis / minor axis) of each particle (100 or more particles measured) is 1. 0 to 1.2.
[0077]
In the toner of the present invention, a charge control agent can be used by mixing (internal addition) with the toner particles or by mixing (externally adding) with the toner particles. The charge control agent makes it possible to control the amount of charge optimally according to the development system. In particular, in the present invention, the balance between the particle size distribution and the amount of charge can be further stabilized. For example, the following substances control the toner to be negatively charged.
[0078]
For example, organic metal complexes and chelate compounds are effective, and examples thereof include monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid-based metal complexes. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.
[0079]
Further, in the toner of the present invention, it is preferable that the second inorganic fine powder is externally added to the developer for the purpose of adding fluidity to the toner. In the present invention 5, the average particle diameter of the second inorganic fine powder is 0.03 μm or less.
[0080]
It is preferable that the second inorganic fine powder is contained by stirring and mixing with a developer and a mixer such as a Henschel mixer.
[0081]
As the second inorganic fine powder used in the present invention, inorganic fine powder such as silica fine powder, titanium oxide, and aluminum oxide are preferable, and silica fine powder is particularly preferable. For example, as the silicic acid fine powder, both a so-called dry method produced by vapor phase oxidation of a silicon halide or a so-called fumed silica, and a so-called wet silica produced from water glass can be used. However, there are few silanol groups on the surface and inside the silica fine powder.₂O, SO₃  ^2-Dry silica with less production residue such as is preferred. In the case of fumed silica, it is also possible to obtain a composite fine powder of silica and another metal oxide by using another metal halide such as aluminum chloride and titanium chloride together with a silicon halide in the production process. They are also included.
[0082]
Further, a material whose surface has been previously rendered hydrophobic with an organic compound may be used. As such an organic treatment method, a method of treating with an organic metal compound such as a silane coupling agent or a titanium coupling agent that reacts or physically adsorbs with the inorganic fine powder; A method of treating with a coupling agent and treating with an organosilicon compound such as silicone oil at the same time.
[0083]
The second inorganic fine powder used in the present invention has a specific surface area of 30 m by nitrogen adsorption measured by the BET method.²/ G or more, especially 50 to 400 m²/ G is preferred.
[0084]
The weight average particle diameter of the toner is preferably 10.0 μm (preferably 8.0 μm) or less. When the weight average particle diameter of the toner is 10.0 μm or less, the effect of preventing “retransfer” is further enhanced. It is considered that when the weight average particle diameter of the toner is 10.0 μm or less, the charge amount of the toner on the latent electrostatic image bearing member or the intermediate transfer member before transfer is further increased.
[0085]
In addition, examples of the method for producing the toner of the present invention include the following methods. In producing the toner according to the present invention, the above-described constituent materials were mixed using a Henschel mixer, a ball mill, a V-type mixer or other mixer, and a hot kneader such as a hot roll kneader or an extruder. It is preferable that the kneading step is performed through a kneading step, a cooling step of solidifying the kneaded material, a pulverizing step using a pulverizer such as a jet mill, and a manufacturing step having at least the above steps. Further, if necessary, it is preferable to go through a classifying step of the pulverized material.
[0086]
Among them, a production method having at least a step of melt-kneading a binder resin and another composition and a pulverization step of finely pulverizing the same is particularly preferable.
[0087]
In the melt-kneading step, when the endothermic peak in the differential thermal analysis is 120 ° C. or less, the dispersion state of the magnetic substance and the charge control agent in the binder resin becomes a preferable state for the present invention. This is because a certain unusual state is exposed as it is on the toner surface, and the effect of preventing "retransfer" of the toner of the present invention is exhibited.
[0088]
In the present invention, SF-1 and SF-2 indicating the shape factor are, for example, randomly sampled 100 toner images of 2 μm or more that have been enlarged 1000 times using FE-SEM (S-800) manufactured by Hitachi, Ltd. Then, the image information is introduced into, for example, an image analysis device (LuzexIII) manufactured by Nicole via an interface, analyzed, and values obtained by the following equation are defined as shape factors SF-1 and SF-2. .
[0089]
(Equation 1)

[0090]
(Where MXLNG is the absolute maximum length of the particle, PERIME is the perimeter of the particle, and AREA is the projected area of the particle.)
[0091]
The shape factor SF-1 indicates the degree of roundness of the toner particles, and the shape coefficient SF-2 indicates the degree of unevenness of the toner particles.
[0092]
The endothermic peak in the differential thermal analysis according to the present invention is measured by a highly accurate internal heating type input compensation type differential scanning calorimeter. For example, DSC-7 manufactured by PerkinElmer can be used. The measurement method is performed according to ASTM D3418-82. The DSC curve used in the present invention uses a DSC curve measured when the temperature is raised once, a pre-history is taken, and then the temperature is decreased and raised at a temperature rate of 10 ° C./min and a temperature range of 0 to 200 ° C. . The endothermic peak temperature is a peak temperature in the positive direction in the DSC curve, that is, a point at which the differential value of the peak curve becomes zero when the value changes from positive to negative.
[0093]
The weight average particle diameter of the toner of the present invention is measured using a Coulter Counter TA-II or a Coulter Multisizer (manufactured by Coulter Inc.). As the electrolyte, a 1% NaCl aqueous solution is prepared using primary sodium chloride. For example, ISOTONR-II (manufactured by Coulter Scientific Japan) can be used. As a measurement method, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the aqueous electrolytic solution, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and the volume and the number of toner particles having a size of 2 μm or more are measured by using the measuring device using a 100 μm aperture as a rear aperture. And the number distribution were calculated. Then, the weight-based weight average particle diameter D4 (the median value of each channel is set as a representative value for each channel) obtained from the volume distribution according to the present invention was obtained.
[0094]
The method for measuring the charge amount of the fine particles of the present invention is as follows. In an environment of a temperature of 23 ° C. and a humidity of 60%, EFV200 / 300 (manufactured by Powder Deck) is used as a carrier, and 10.0 g of the carrier and 0. 2 g is placed in a 50 ml polyethylene container and shaken by hand 90 times. Next, about 1 g of the mixture is put in a metal measuring container 2 having a 500-mesh screen 3 at the bottom as shown in FIG. At this time, the weight of the entire measurement container 2 is measured and defined as W1 (g). Next, it is placed on a suction machine (the part in contact with the measurement container 2 is an insulator), suction is performed from the suction port 7 at a pressure of 2450 Pa (250 mmAq), and suction is performed for 2 minutes in this state to remove fine particles. The potential of the electrometer 9 at this time is set to V (volt). Here, reference numeral 8 denotes a capacitor, whose capacity is C (mF). The weight of the whole measuring container 2 after suction is measured, and it is defined as W2 (g). The charge amount T (mC / kg) of the fine particles is
Charge amount T (mC / kg) = C × V / (W1-W2)
Is calculated by the above equation.
[0095]
【Example】
Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.
[0096]

After preliminarily mixing the above materials, melt kneading was performed by a biaxial kneading extruder set at 130 ° C. After cooling the kneaded material, it was roughly pulverized, finely pulverized by a pulverizer using a jet stream, and further classified using an air classifier. Further, surface treatment was performed by mechanical impact force to obtain black powder (toner particles) A.
[0097]
Titanium oxide fine particles (crystal form: rutile type, average particle diameter: 0.3 μm, charge amount: -2.8 mC / kg) as metal oxide fine particles (fine particles 1) with respect to 100 parts by mass of the toner particles A: 0.5 parts by mass and 1.2 parts by mass of dry silica treated with hexamethyldisilazane / dimethylsilicone oil: 1.2 parts by mass with a Henschel mixer 10B under stirring at 3200 rpm for 2 minutes to obtain a toner.
[0098]
The weight average particle diameter of the obtained toner was 6.9 μm, SF-1 was 144, and SF-2 was 126. The endothermic peak in the differential thermal analysis was at 102 ° C.
[0099]
When the surface of the toner was observed with an electron microscope, it was found that the fine particles 1 were attached to the surface of the toner particles as they were and were not embedded in the surface.
[0100]
(Example 26And Comparative Example 1~ 4)
Toners shown in Table 6 were obtained in the same manner as in Example 1, except that the fine particles added in Example 1 were fine particles 2 to 7 and fine particles 9 to 11 shown in Table 1.
[0101]
(Example7,8)
A toner shown in Table 6 was obtained in the same manner as in Example 1 except that the amount of the fine particles 1 added in Example 1 was changed to the amount shown in Table 6.
[0102]
(Example9~Fifteen)
Toner particles B to H were obtained in the same manner as in Example 1 except that the substances shown in Table 5 were added instead of the low-molecular-weight polyethylene added in Example 1, and otherwise, Table 6 was obtained in the same manner as in Example 1. Was obtained.
[0103]
(Comparative Example 5 andExample16,17)
Toner particles I to K were obtained in the same manner as in Example 1 except that the mechanical impact treatment performed in Example 1 was not performed, and the shape shown in Table 5 was adjusted by adjusting the conditions of the mechanical impact treatment. Other than that, the toner shown in Table 6 was obtained in the same manner as in Example 1.
[0104]
(Example18~21 and Comparative Example 6)
Styrene-butyl acrylate copolymer 100 parts by mass
Magnetite (shape: spherical, average particle size: 0.2 μm) 80 parts by mass
Triphenylmethane dye (positive charge control agent) 2 parts by mass
Low molecular weight polyethylene (Differential thermal analysis endothermic peak: 102 ° C,
Mw / Mn: 1.3) 4 parts by mass
After preliminarily mixing the above materials, melt kneading was performed by a biaxial kneading extruder set at 130 ° C. After cooling the kneaded material, the mixture was roughly pulverized, finely pulverized by a pulverizer using a jet stream, and further classified using an air classifier.
[0105]
Further, the surface was treated by mechanical impact to obtain a black powder (toner particles) L.
[0106]
0.5 parts by mass of

fine powders

1, 3, 4, 6, and 8, and 0.8 parts by mass of dry silica modified with amino-modified silicone oil are added to Henschel mixer 10B with respect to 100 parts by mass of toner particles L described above. And stirred and mixed at 3200 rpm for 2 minutes to obtain a toner.
[0107]
The weight average particle size of the obtained toner was 7.6 μm, SF-1 was 146, SF-2 was 124, and the ratio B / A was 0.52. The endothermic peak in the differential thermal analysis was at 102 ° C.
[0108]
(Example22~26)
A toner was obtained in the same manner as in Example 1 except that the fine particles to be added were changed to fine metal titanate particles or fine metal silicate particles 12 to 16 shown in Table 2.
[0109]
(Example27,28)
Example25Except that the addition amount of the fine particles 15 to be added in the step is set to the amount shown in Table 7,25A toner was obtained in the same manner as described above.
[0110]
(Example29~35)
A toner shown in Table 7 was obtained in the same manner as in Example 1 except that the fine particles 15 were added to the toner particles B to H shown in Table 5.
[0111]
(Example36,37)
A toner shown in Table 7 was obtained in the same manner as in Example 1 except that the fine particles 15 were added to the toner particles J and K shown in Table 5.
[0112]
(Example38)
Example18Example 1 except that the fine particles 15 were used instead of the fine particles used in18A toner was obtained in the same manner as described above.
[0113]
(Example39~41)
A toner was obtained in the same manner as in Example 1, except that the fine particles added in Example 1 were metal carbide fine particles 17 to 19 shown in Table 3.
[0114]
(Example42,43)
Example39Example 8 except that the addition amount of the fine particles 17 to be added in the step was set to the amount shown in Table 8.39A toner was obtained in the same manner as described above.
[0115]
(Example44~50)
A toner shown in Table 8 was obtained in the same manner as in Example 1 except that the fine particles 17 were added to the toner particles B to H shown in Table 5.
[0116]
(Comparative Example 7 andExample51, 52)
A toner shown in Table 8 was obtained in the same manner as in Example 1 except that the fine particles 17 were added to the toner particles I to K shown in Table 5.
[0117]
(Example53)
Example18Example except that the fine particles 17 were used instead of the fine particles used in Example18A toner was obtained in the same manner as described above.
[0118]
(Example54~56)
A toner was obtained in the same manner as in Example 1, except that the fine particles added in Example 1 were metal carbonate fine particles 20 to 22 shown in Table 4.
[0119]
(Example57,58)
Example54Except that the amount of the fine particles 20 to be added in the step was changed to the amount shown in Table 9,54A toner was obtained in the same manner as described above.
[0120]
(Example59~65)
A toner shown in Table 9 was obtained in the same manner as in Example 1 except that the fine particles 20 were added to the toner particles B to H shown in Table 5.
[0121]
(Comparative Example 8 andExample66,67)
Toners shown in Table 9 were obtained in the same manner as in Example 1 except that the fine particles 20 were added to the toner particles I to K shown in Table 5.
[0122]
(Example68)
Example18Example 1 except that the fine particles 20 were used instead of the fine particles used in18A toner was obtained in the same manner as described above.
[0123]

After preliminarily mixing the above materials, melt kneading was performed by a biaxial kneading extruder set at 130 ° C. After cooling the kneaded material, the mixture was roughly pulverized, finely pulverized by a pulverizer using a jet stream, and further classified using an air classifier to obtain black powder (toner particles) M.
[0124]
To 100 parts by weight of the toner particles M, 0.4 parts by weight of dry silica treated with hexamethyldisilazane / dimethylsilicone oil was stirred and mixed at 3200 rpm for 2 minutes using a Henschel mixer 10B to obtain a toner.
[0125]
The weight average particle diameter of the obtained toner was 11.3 μm, SF-1 was 160, and SF-2 was 154. The endothermic peak in differential thermal analysis was at 145 ° C.
[0126]
<Evaluation>
The toners of the above Examples and Comparative Examples were evaluated by the following methods. The results are shown in Tables 6 to 10.
[0127]
1) Evaluation of transferability
Using a laser beam printer LBP-1260 modified by Canon and equipped with a variable transfer bias power supply, a solid black image was developed in an environment of 23 ° C./60% RH, and 75 g / m 2.²The transfer residual image left on the photoreceptor is cut off with a transparent polyester adhesive tape and pasted on white paper, and its reflection density is measured with a Macbeth reflection densitometer. The density of the portion stuck on the top was evaluated by subtracting the density therefrom. The transfer voltage was evaluated in increments of 0.5 kV from 1.0 to 3.0 kV.
[0128]
2) Evaluation of image density / fog
Using a Canon laser beam printer LBP-1260 and a Canon copier PC330, after printing 1,000 sheets in an environment of 32 ° C./80%, the apparatus was left for 2 days, and then a solid black image was printed. The image density was measured and evaluated with a Macbeth reflection densitometer.
[0129]
At the same time, a solid white image is printed. evaluated.
[0130]
[Table 1]

[0131]
[Table 2]

[0132]
[Table 3]

[0133]
[Table 4]

[0134]
[Table 5]

[0135]
[Table 6]

[0136]
[Table 7]

[0137]
[Table 8]

[0138]
[Table 9]

[0139]
[Table 10]

[0140]
(Production Example 1 of Silicon Oxide Fine Particles Containing Silicone Oil)
Silica fine powder synthesized by a dry method (specific surface area: 52 m²/ G) in a closed Henschel mixer heated to 80 ° C., and dimethyl silicone oil diluted with xylene to 10 parts by mass with respect to 100 parts by mass of the silica fine powder (viscosity at 25 ° C .: 50 cSt) ) Was stirred at high speed while spraying, and then the solvent was volatilized to obtain silica (silicon oxide) fine particles a containing silicone oil.
[0141]
(Production Example 2 of Silicon Oxide Fine Particles Containing Silicone Oil)
Silica fine powder synthesized by a dry method (specific surface area: 15 m²/ G) in a closed Henschel mixer heated to 80 ° C., and dimethyl silicone oil (viscosity at 25 ° C.) diluted with xylene to 8.5 parts by mass with respect to 100 parts by mass of the silica fine powder. : 50 cSt) and high-speed stirring while spraying an amino-modified silicone oil (viscosity at 25 ° C: 50 cSt) diluted with xylene to 1.5 parts by mass, then volatilize the solvent and contain the silicone oil Silica (silicon oxide) fine particles b were obtained.
[0142]
(Production Example 3 of Silicon Oxide Fine Particles Containing Silicone Oil)
The original silica fine powder which has been surface-treated with hexamethyldisilazane (specific surface area: 47 m²/ G), to obtain silica (silicon oxide) fine particles c containing silicone oil in the same manner as in Production Example 1.
[0143]
(Production Example 4 of Silicon Oxide Fine Particles Containing Silicone Oil)
Specific surface area is 100m as original silica fine powder²/ G of silica (silicon oxide) fine particles containing silicone oil in the same manner as in Production Example 1 except that the silica / silicon oxide was used.
[0144]
(Production Example 5 of Silicon Oxide Fine Particles Containing Silicone Oil)
Silica fine powder synthesized by a dry method (specific surface area: 200 m²/ G) into a sealed Henschel mixer heated to 80 ° C., and dimethyl silicone oil diluted with xylene to 100 parts by mass with respect to 100 parts by mass of the silica fine powder (viscosity at 25 ° C .: 10,000 cSt) ) Was stirred at high speed while spraying, and then the solvent was volatilized to obtain silica (silicon oxide) fine particles e containing silicone oil.
[0145]
(Production Example 6 of Silicon Oxide Fine Particles Containing Silicone Oil)
Silica fine powder synthesized by a dry method (specific surface area: 200 m²/ G) in a closed Henschel mixer heated to 80 ° C., and dimethyl silicone oil diluted with xylene to 85 parts by mass with respect to 100 parts by mass of the silica fine powder (viscosity at 25 ° C .: 10,000 cSt) ) And an amino-modified silicone oil diluted with xylene so as to have a mass of 15 parts by mass while stirring at a high speed, and thereafter, the solvent is volatilized to obtain silica (silicon oxide) fine particles f containing the silicone oil. .
[0146]
(Production Example 7 of silicon composite oxide fine particles containing silicone oil)
Silicon-aluminum composite oxide containing 1% aluminum element (specific surface area: 45 m²/ G) in a sealed Henschel mixer heated to 80 ° C., and dimethyl silicone oil diluted with xylene to 10 parts by mass with respect to 100 parts by mass of the silica fine powder (viscosity at 25 ° C .: 50 cSt) ) Was stirred at high speed while spraying, and then the solvent was volatilized to obtain silicon-aluminum composite oxide (silicon composite oxide) fine particles g containing silicone oil.
[0147]
Table 11 shows various physical property values of the obtained fine particles a to g of the silicon oxide or silicon composite oxide.
[0148]
[Table 11]

[0149]

After preliminarily mixing the above materials, melt kneading was performed by a biaxial kneading extruder set at 130 ° C. After cooling the kneaded material, it was roughly pulverized, finely pulverized by a pulverizer using a jet stream, and further classified using an air classifier. Further, the surface was treated by mechanical impact to obtain black powder (toner particles) N.
[0150]
Fine particles a surface-treated with dimethyl silicone oil: 0.5 parts by mass, dry silica treated with hexamethyldisilazane / dimethyl silicone oil (average particle size: 0.01 μm): 100 parts by mass of toner particles N: 1.2 parts by mass were stirred and mixed with a Henschel mixer 10B at 3200 rpm for 2 minutes to obtain a toner.
[0151]
The weight average particle diameter of the obtained toner was 6.9 μm, SF-1 was 144, and SF-2 was 126. The endothermic peak in the differential thermal analysis was at 102 ° C.
[0152]
When the surface of the toner was observed with an electron microscope, the average particle size of the fine particles a surface-treated with dimethyl silicone oil was 0.04 μm, and the fine particles a were not embedded in the toner surface while adhering to the toner particle surfaces. .
[0153]
(Example70~74And comparative examples10)
Example69In Examples, except that fine particles b to g shown in Table 11 were used as fine particles added in69A toner was obtained in the same manner as described above.
[0154]
(Example75~77)
Example69Examples except that the addition amount of the fine particles a to be added in the step was adjusted to the amount shown in Table69A toner was obtained in the same manner as described above.
[0155]
(Example78~84)
Example69Examples except that the substances shown in Table 12 were added instead of the low molecular weight polyethylene added in69In the same manner as in Example 1, toner particles OU were obtained.69A toner was obtained in the same manner as described above.
[0156]
(Example85,86)
Example69Machines performed inMachineThe example was the same as the example except that the shape was adjusted to the shape shown in Table 12 by adjusting the conditions of the shock treatment.69In the same manner as in Example 1, toner particles V and W were obtained.69A toner was obtained in the same manner as described above.
[0157]

After preliminarily mixing the above materials, melt kneading was performed by a biaxial kneading extruder set at 130 ° C. After cooling the kneaded material, the mixture was roughly pulverized, finely pulverized by a pulverizer using a jet stream, and further classified using an air classifier to obtain black fine powder (toner particles) X shown in Table 12. The endothermic peak in differential thermal analysis was at 145 ° C.
[0158]
0.4 parts by mass of dry silica (average particle size: 0.01 μm) treated with hexamethyldisilazane / dimethylsilicone oil is mixed with 100 parts by mass of the toner particles X at 3200 rpm for 2 minutes with a Henschel mixer 10B. A toner was obtained.
[0159]
The weight average particle diameter of the obtained toner was 11.3 μm, SF-1 was 160, and SF-2 was 154.
[0160]
<Evaluation>
The above embodiment69~86And comparative examples10,11Were evaluated by the following methods. The results are shown in Tables 13 and 14.
[0161]
1) Evaluation of transferability
Example 168The same procedure was followed.
[0162]
2) Evaluation of image density / fog
Except that the number of images was set to 2,000,68The same procedure was followed.
[0163]
[Table 12]

[0164]
[Table 13]

[0165]
[Table 14]

[0166]
【The invention's effect】
According to the present invention, "retransfer" does not occur even under a high transfer current condition, and an image with high image density and good image quality can be obtained.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of an apparatus for measuring a charge amount of a toner of the present invention.

Claims

In a toner for electrostatic image development having toner particles containing at least a binder resin and a colorant and inorganic fine particles externally added to the toner particles,
The toner particles, which are at least a binder resin and a step of melting and kneading a colorant, at least through to produce a step of performing spheroidizing process adding step and grinding step after mechanical impact grinding it,
The inorganic fine particles have an average particle size of 0.05 to 2.0 μm and have the following formula (1)
M _x O _y ... (1)
(In the formula, M represents an aluminum element, a titanium element, a zinc element or a zirconium element, O represents an oxygen element, and x and y represent positive numbers other than 0.)
Having metal oxide fine particles represented by
The toner has one or more endothermic peaks at 120 ° C. or lower in differential thermal analysis,
The toner has a shape factor SF-1 value measured by an image analyzer within a range of 110 to 180, a shape factor SF-2 value within a range of 110 to 140, and a value of SF-2. A toner for developing electrostatic images, wherein a ratio B / A of a value B obtained by subtracting 100 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less.

2. The toner according to claim 1, wherein the metal oxide fine particles have an average particle diameter in a range of 0.1 to 1.0 [mu] m.

3. The electrostatic image developing toner according to claim 1, wherein the charged polarity of the metal oxide fine particles to the iron powder carrier is the same as the charged polarity of the toner particles to the iron powder carrier.

4. The electrostatic image developing toner according to claim 1, wherein the charged polarity of the metal oxide fine particles with respect to the iron powder carrier is | 20 | .mu.C / g or less.

The toner for developing an electrostatic image according to any one of claims 1 to 4, wherein the metal oxide fine particles have an electrification polarity with respect to an iron powder carrier of | 10 | µC / g or less.

6. The electrostatic image developing toner according to claim 1, wherein M in the formula of the metal oxide fine particles is a titanium element.

6. The electrostatic image developing toner according to claim 1, wherein the metal oxide fine particles are rutile-type titanium oxide.

The electrostatic image developing toner according to any one of claims 1 to 7, wherein the toner has one or more endothermic peaks in differential thermal analysis in a range of 60C to 120C.

9. The toner according to claim 8, wherein the toner has one or more endothermic peaks in differential thermal analysis in a region of 70 [deg.] C. or higher.

The toner according to claim 8, wherein the toner has one or more endothermic peaks in differential thermal analysis in a region of 110 ° C. or lower.

11. The toner according to claim 1, wherein the toner particles contain at least one wax component selected from the group consisting of polyolefin wax, hydrocarbon wax obtained by Fischer-Tropsch method, petroleum wax and higher alcohol. The toner for developing an electrostatic charge image according to any of the above items.

11. The toner according to claim 1, wherein the toner particles contain at least one wax component selected from the group consisting of polyolefin wax, hydrocarbon wax obtained by Fischer-Tropsch method, and petroleum wax. For developing electrostatic images.

13. The electrostatic charge according to claim 11, wherein the wax component has a Mw / Mn in the range of 1.0 to 2.0 in a molecular weight distribution measured by gel permeation chromatography (GPC). Image developing toner.

The toner has a shape factor SF-1 value measured by an image analyzer within a range of 120 to 160, a shape factor SF-2 value of 115 to 140, and a value of SF-2. 14. The electrostatic charge according to claim 1, wherein a ratio B / A of a value B obtained by subtracting 100 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less. Image developing toner.

15. The electrostatic image developing toner according to claim 1, wherein a styrene copolymer is used as the binder resin.

16. The toner for developing an electrostatic image according to claim 1, wherein a magnetic material is contained in the toner particles as the colorant.

17. The toner according to claim 16, wherein the magnetic material is a magnetic iron oxide having a substantially spherical shape.

18. The electrostatic image developing toner according to claim 1, wherein the toner has a weight average particle diameter of 10.0 [mu] m or less.

18. The toner according to claim 1, wherein the toner has a weight average particle diameter of 8.0 [mu] m or less.

20. The electrostatic image developing toner according to claim 1, wherein the toner particles have been subjected to at least a spheroidizing treatment for applying a mechanical impact force.

In a toner for electrostatic image development having toner particles containing at least a binder resin and a colorant and inorganic fine particles externally added to the toner particles,
The toner particles, which are at least a binder resin and a step of melting and kneading a colorant, at least through to produce a step of performing spheroidizing process adding step and grinding step after mechanical impact grinding it,
The inorganic fine particles have the following formula (2) or (3) having an average particle size of 0.1 to 3.0 μm.
M _x Ti _y O _z (2)
M _x Si _y O _z (3)
(In the formula, M indicates a metal element, Ti indicates a titanium element, Si indicates a silicon element, O indicates an oxygen element, and x and y indicate non-zero positive numbers.)
Having composite metal oxide fine particles represented by
The toner has one or more endothermic peaks at 120 ° C. or lower in differential thermal analysis,
The toner has a shape factor SF-1 value measured by an image analyzer within a range of 110 to 180, a shape factor SF-2 value within a range of 110 to 140, and a value of SF-2. A toner for developing electrostatic images, wherein a ratio B / A of a value B obtained by subtracting 100 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less.

22. The electrostatic image developing toner according to claim 21 , wherein the composite metal oxide fine particles have an average particle diameter in a range of 0.2 to 2.0 [mu] m.

The charge polarity to iron powder carrier of composite metal oxide particles, toner according to claim 21 or 22, characterized in that it has a charge with the same polarity to iron powder carrier of the toner particles.

The charge polarity to iron powder carrier of composite metal oxide particles, | 20 | toner according to any one of claims 21 to 23, characterized in that [mu] C / g or less.

The charge polarity to iron powder carrier of composite metal oxide particles, | 10 | toner according to any one of claims 21 to 23, characterized in that [mu] C / g or less.

The composite metal oxide fine particles, an electrostatic charge image developing toner according to any one of claims 21 to 25, characterized in that a strontium titanate or strontium silicate.

The composite metal oxide fine particles, an electrostatic charge image developing toner according to any one of claims 21 to 25, characterized in that a mixed crystal of strontium titanate and strontium silicate.

The toner is the electrostatic image developing toner according to any one of claims 21 to 27, characterized in that it has more than one endothermic peak in differential thermal analysis in the region of 60 ° C. to 120 ° C..

29. The electrostatic image developing toner according to claim 28 , wherein the toner has one or more endothermic peaks in differential thermal analysis in a region of 70 ° C. or higher.

The toner is the electrostatic image developing toner according to claim 28 or 29, characterized in that it has more than one of the following areas 110 ° C. The endothermic peak in differential thermal analysis.

Said toner particles are polyolefin waxes, hydrocarbon waxes by the Fischer-Tropsch process, more of claims 21 to 30, characterized in that it contains one or more wax components selected from the group consisting of petroleum waxes and higher alcohols The toner for developing an electrostatic image according to any one of the above items.

The toner particles according to any one of claims 21 to 30, characterized in that it contains one or more wax components selected from the group consisting of polyolefin waxes, hydrocarbon waxes and petroleum waxes according to the Fischer-Tropsch process For developing electrostatic images.

The wax component, in molecular weight distribution by gel permeation chromatography (GPC) measurement, Mw / Mn is, the static charges of claim 31 or 32, characterized in that in the range of 1.0 to 2.0 Image developing toner.

The toner has a shape factor SF-1 value measured by an image analyzer within a range of 120 to 160, a shape factor SF-2 value of 115 to 140, and a value of SF-2. The electrostatic charge according to any one of claims 21 to 33 , wherein a ratio B / A of a value B obtained by subtracting 100 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less. Image developing toner.

As the binder resin, toner according to any one of claims 21 to 34, characterized by using a styrene copolymer.

The toner for developing an electrostatic image according to any one of claims 21 to 35 , wherein a magnetic material is contained in the toner particles as the colorant.

37. The toner according to claim 36 , wherein the magnetic material is a magnetic iron oxide having a substantially spherical shape.

The electrostatic image developing toner according to any one of claims 21 to 37 , wherein the toner has a weight average particle diameter of 10.0 µm or less.

The electrostatic image developing toner according to any one of claims 21 to 37 , wherein the toner has a weight average particle diameter of 8.0 µm or less.

The electrostatic image developing toner according to any one of claims 21 to 39 , wherein the toner particles have been subjected to a spheroidizing treatment for applying at least a mechanical impact force.

In a toner for electrostatic image development having toner particles containing at least a binder resin and a colorant and inorganic fine particles externally added to the toner particles,
The toner particles, which are at least a binder resin and a step of melting and kneading a colorant, at least through to produce a step of performing spheroidizing process adding step and grinding step after mechanical impact grinding it,
The inorganic fine particles have an average particle diameter of 0.05 to 2.0 μm inorganic carbide fine particles,
The toner has one or more endothermic peaks at 120 ° C. or lower in differential thermal analysis,
The toner has a shape factor SF-1 value measured by an image analyzer within a range of 110 to 180, a shape factor SF-2 value within a range of 110 to 140, and a value of SF-2. A toner for developing electrostatic images, wherein a ratio B / A of a value B obtained by subtracting 100 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less.

42. The toner according to claim 41 , wherein the inorganic carbide fine particles have an average particle diameter in a range of 0.1 to 1.0 [mu] m.

Charge polarity to iron powder carrier of the inorganic carbide particles, toner according to claim 41 or 42, characterized in that it has a charge with the same polarity to iron powder carrier of the toner particles.

The electrostatic image developing toner according to any one of claims 41 to 43 , wherein a charging polarity of the inorganic carbide fine particles with respect to the iron powder carrier is | 30 | µC / g or less.

The electrostatic image developing toner according to any one of claims 41 to 43 , wherein a charging polarity of the inorganic carbide fine particles with respect to the iron powder carrier is | 20 | C / g or less.

The electrostatic image developing toner according to any one of claims 41 to 45 , wherein the inorganic carbide fine particles are silicon carbide.

The toner is the electrostatic image developing toner according to any one of claims 41 to 46, characterized in that it has more than one endothermic peak in differential thermal analysis in the region of 60 ° C. to 120 ° C..

48. The toner for developing an electrostatic image according to claim 47 , wherein the toner has one or more endothermic peaks in differential thermal analysis in a region of 70 ° C or higher.

The toner is the electrostatic image developing toner according to claim 47 or 48, characterized in that it has more than one of the following areas 110 ° C. The endothermic peak in differential thermal analysis.

Said toner particles are polyolefin waxes, hydrocarbon waxes by the Fischer-Tropsch process, more of claims 41 to 49, characterized in that it contains one or more wax components selected from the group consisting of petroleum waxes and higher alcohols The toner for developing an electrostatic image according to any one of the above items.

The toner particles according to any of the polyolefin wax, claims 41 to 49, characterized in that it contains one or more wax components selected from the group consisting of hydrocarbon waxes and petroleum waxes according to the Fischer-Tropsch process For developing electrostatic images.

The wax component, in molecular weight distribution by gel permeation chromatography (GPC) measurement, Mw / Mn is, the static charges of claim 50 or 51, characterized in that in the range of 1.0 to 2.0 Image developing toner.

The toner has a shape factor SF-1 value measured by an image analyzer within a range of 120 to 160, a shape factor SF-2 value of 115 to 140, and a value of SF-2. 53. The electrostatic charge according to claim 41 , wherein a ratio B / A of a value B obtained by subtracting 100 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less. Image developing toner.

As the binder resin, toner according to any one of claims 41 to 53, characterized by using a styrene copolymer.

The toner for developing an electrostatic image according to any one of claims 41 to 54 , wherein the toner particles contain a magnetic material as the colorant.

56. The toner according to claim 55 , wherein the magnetic material is a magnetic iron oxide having a substantially spherical shape.

The toner is the electrostatic image developing toner according to any one of claims 41 to 56, wherein the weight average particle diameter is less than 10.0 [mu] m.

The toner is the electrostatic image developing toner according to any one of claims 41 to 56, wherein the weight average particle diameter is less than 8.0 .mu.m.

The electrostatic image developing toner according to any one of claims 41 to 58 , wherein the toner particles have been subjected to a spheroidizing treatment for applying at least a mechanical impact force.

In a toner for electrostatic image development having toner particles containing at least a binder resin and a colorant and inorganic fine particles externally added to the toner particles,
The toner particles, which are at least a binder resin and a step of melting and kneading a colorant, at least through to produce a step of performing spheroidizing process adding step and grinding step after mechanical impact grinding it,
The inorganic fine particles have metal carbonate fine particles having an average particle size of 0.05 to 2.0 μm,
The toner has one or more endothermic peaks at 120 ° C. or lower in differential thermal analysis,
The toner has a shape factor SF-1 value measured by an image analyzer within a range of 110 to 180, a shape factor SF-2 value within a range of 110 to 140, and a value of SF-2. A toner for developing electrostatic images, wherein a ratio B / A of a value B obtained by subtracting 100 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less.

61. The electrostatic image developing toner according to claim 60 , wherein the metal carbonate fine particles have an average particle diameter in a range of 0.1 to 1.0 [mu] m.

62. The electrostatic image developing toner according to claim 60 , wherein the charged polarity of the metal carbonate fine particles with respect to the iron powder carrier has the same polarity as the charged polarity of the toner particles with respect to the iron powder carrier.

The electrostatic image developing toner according to any one of claims 60 to 62 , wherein the charged polarity of the metal carbonate fine particles to the iron powder carrier is | 20 | µC / g or less.

Charge polarity to iron powder carrier of the metal carbonate particles, | 10 | μC / g toner according to any one of claims 60 to 62, characterized in that less.

The toner according to any one of claims 60 to 64, characterized in that the metal carbonate particles are strontium carbonate.

The toner for developing an electrostatic image according to any one of claims 60 to 65 , wherein the toner has one or more endothermic peaks in a differential thermal analysis in a range of 60 ° C to 120 ° C.

67. The toner for developing an electrostatic image according to claim 66 , wherein the toner has one or more endothermic peaks in differential thermal analysis in a region of 70C or higher.

68. The electrostatic image developing toner according to claim 66 , wherein the toner has one or more endothermic peaks in differential thermal analysis in a region of 110 ° C. or lower.

Said toner particles are polyolefin waxes, hydrocarbon waxes by the Fischer-Tropsch process, more of claims 60 to 68, characterized in that it contains one or more wax components selected from the group consisting of petroleum waxes and higher alcohols The toner for developing an electrostatic image according to any one of the above items.

The toner particles described polyolefin wax, claim 60 or 68, characterized in that it contains one or more wax components selected from the group consisting of hydrocarbon waxes and petroleum waxes according to the Fischer-Tropsch process For developing electrostatic images.

The wax component in the molecular weight distribution by gel permeation chromatography (GPC) measurement, Mw / Mn is, electrostatic charge according to claim 69 or 70, characterized in that in the range of 1.0 to 2.0 Image developing toner.

The toner has a shape factor SF-1 value measured by an image analyzer within a range of 120 to 160, a shape factor SF-2 value of 115 to 140, and a value of SF-2. 72. The electrostatic charge according to any one of claims 60 to 71 , wherein a ratio B / A of a value B obtained by subtracting 100 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less. Image developing toner.

The electrostatic image developing toner according to any one of claims 60 to 72 , wherein a styrene copolymer is used as the binder resin.

The toner according to any one of claims 60 to 73, characterized in that the magnetic material is contained as a colorant in the toner particles.

75. The toner according to claim 74 , wherein the magnetic material is a magnetic iron oxide having a substantially spherical shape.

The electrostatic image developing toner according to any one of claims 60 to 75 , wherein the toner has a weight average particle diameter of 10.0 µm or less.

The electrostatic image developing toner according to any one of claims 60 to 75 , wherein the toner has a weight average particle diameter of 8.0 µm or less.

The electrostatic image developing toner according to any one of claims 60 to 77 , wherein the toner particles are subjected to at least a spheroidizing treatment for applying a mechanical impact force.

In a toner for electrostatic image development having toner particles containing at least a binder resin and a colorant and inorganic fine particles externally added to the toner particles,
The toner particles, which are at least a binder resin and a step of melting and kneading a colorant, at least through to produce a step of performing spheroidizing process adding step and grinding step after mechanical impact grinding it,
The inorganic fine particles have silicon oxide fine particles or silicon composite oxide fine particles containing silicone oil and having an average particle size of 0.03 to 50 μm,
The toner has one or more endothermic peaks at 120 ° C. or lower in differential thermal analysis,
The toner has a shape factor SF-1 value measured by an image analyzer within a range of 110 to 180, a shape factor SF-2 value within a range of 110 to 140, and a value of SF-2. A toner for developing electrostatic images, wherein a ratio B / A of a value B obtained by subtracting 100 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less.

80. The toner according to claim 79 , wherein the silicon oxide fine particles or the silicon composite oxide fine particles have an average particle diameter in a range of 0.04 to 1.0 m.

81. The electrostatic image developing toner according to claim 79 , wherein the toner further has fine particles having an average particle diameter of less than 0.03 [mu] m as an external additive.

The toner according to claim 81 , wherein the fine particles having an average particle diameter of less than 0.03 µm include silicon oxide fine particles or silicon composite oxide fine particles.

The average particle size of less than 0.03μm particles, toner according to claim 81 or 82, characterized in that it contains a silicone oil.

84. The toner for developing an electrostatic image according to any one of claims 79 to 83 , wherein the toner has one or more endothermic peaks in a differential thermal analysis in a range of 60C to 120C.

85. The toner for developing an electrostatic image according to claim 84 , wherein the toner has one or more endothermic peaks in differential thermal analysis in a region of 70 ° C or higher.

The toner is the electrostatic image developing toner according to claim 84 or 85, characterized in that it has more than one of the following areas 110 ° C. The endothermic peak in differential thermal analysis.

Said toner particles are polyolefin waxes, hydrocarbon waxes by the Fischer-Tropsch process, more of claims 79 to 86, characterized in that it contains one or more wax components selected from the group consisting of petroleum waxes and higher alcohols The toner for developing an electrostatic image according to any one of the above items.

The toner particles according to any one of claims 79 to 86, characterized in that it contains one or more wax components selected from the group consisting of polyolefin waxes, hydrocarbon waxes and petroleum waxes according to the Fischer-Tropsch process For developing electrostatic images.

The electrostatic charge according to claim 87 or 88 , wherein the wax component has a Mw / Mn in a range of 1.0 to 2.0 in a molecular weight distribution measured by gel permeation chromatography (GPC). Image developing toner.

The toner has a shape factor SF-1 value measured by an image analyzer within a range of 120 to 160, a shape factor SF-2 value of 115 to 140, and a value of SF-2. The electrostatic charge according to any one of claims 79 to 89 , wherein a ratio B / A of a value B obtained by subtracting 100 and a value A obtained by subtracting 100 from the value of SF-1 is 1.0 or less. Image developing toner.

The electrostatic image developing toner according to any one of claims 79 to 90 , wherein a styrene copolymer is used as the binder resin.

The electrostatic image developing toner according to any one of claims 79 to 91 , wherein a magnetic material is contained as the colorant in the toner particles.

The toner according to claim 92 , wherein the magnetic material is a magnetic iron oxide having a substantially spherical shape.

The electrostatic image developing toner according to any one of claims 79 to 93 , wherein the toner has a weight average particle diameter of 10.0 µm or less.

The toner according to any one of claims 79 to 93 , wherein the toner has a weight average particle size of 8.0 µm or less.

The electrostatic image developing toner according to any one of claims 79 to 95 , wherein the toner particles have been subjected to a spheroidizing treatment for applying at least a mechanical impact force.