JP3956657B2 - Oilless fixing toner, method for producing the toner, and oilless fixing method - Google Patents

Description

（式中、R^１、R^２、R^３およびR^４はそれぞれ独立して水素原子、ハロゲン原子、または炭素数1〜4のアルキル基、例えばメチル基、エチル基、ｎ-プロピル基、ｎ-ブチル基であり、好ましくは水素原子、塩素原子、臭素原子、またはメチル基である）で表されるスチレン系モノマーと、一般式（2）；
【化２】

（式中、R^５、R^６およびR^７はそれぞれ独立して水素原子、ハロゲン原子、または炭素数1〜6のアルキル基、例えばメチル基、エチル基、ｎ-プロピル基、ｎ-ブチル基、ｎ-ペンチル基、ｎ-ヘキシル基であり、好ましくは水素原子、塩素原子、臭素原子、またはメチル基である）で表されるインデン系モノマーが挙げられる。
【００３３】
スチレン系モノマーの具体例としては、例えば、スチレン、ビニルトルエン、α−メチルスチレン、イソプロペニルトルエン、β−メチルスチレン、１−プロペニルトルエン、ｏ−クロロスチレン、ｍ−クロロスチレン、ｐ−クロロスチレン、α−クロロスチレン、β−クロロスチレン、ｏ−ブロモスチレン、ｍ−ブロモスチレン、ｐ−ブロモスチレン、α−ブロモスチレン、β−ブロモスチレン等が挙げられ、好ましくはスチレン、ビニルトルエン、α−メチルスチレン、イソプロペニルトルエン、β−メチルスチレン、１−プロペニルトルエン、より好ましくはスチレン、ビニルトルエン、α−メチルスチレン、イソプロペニルトルエン、さらに好ましくはスチレン、α−メチルスチレン、イソプロペニルトルエンである。
インデン系モノマーの具体例としては、例えば、インデン、メチルインデン、エチルインデン等が挙げられ、これらの中でもインデンが特に好ましい。
芳香族モノマーは単独でまたは組み合わせて用いてもよい。
【００３４】
脂肪族モノマーの具体例としては、上記芳香族モノマーと重合可能であれば特に制限されず、例えば、イソプレン、ピペリレン、1,3-ブタジエン、1,3-ペンタジエン、1,5-ヘキサジエン、2,3-ジメチル-1,3-ブタジエン、クロロプレン、2-ブロモ-1,3-ブタジエン等のジオレフィン系モノマー；エチレン、プロピレン、ブチレン、イソブチレン、２−メチル−ブテン−1、2−メチルブテン−2等のモノオレフィン系モノマー；アクリル酸メチル、アクリル酸エチル、アクリル酸ｎ−プロピル、アクリル酸イソプロピル、アクリル酸ｎ−ブチル、アクリル酸イソブチル、アクリル酸ｔ−ブチル、アクリル酸ｎ−ペンチル、アクリル酸イソペンチル、アクリル酸ネオペンチル、アクリル酸３−(メチル)ブチル、アクリル酸ヘキシル、アクリル酸オクチル、アクリル酸ノニル、アクリル酸デシル、アクリル酸ウンデシル、アクリル酸ドデシル等のアクリル酸アルキルエステル系モノマー；メタクリル酸メチル、メタクリル酸エチル、メタクリル酸ｎ−プロピル、メタクリル酸イソプロピル、メタクリル酸ｎ−ブチル、メタクリル酸イソブチル、メタクリル酸ｔ−ブチル、メタクリル酸ｎ−ペンチル、メタクリル酸イソペンチル、メタクリル酸ネオペンチル、メタクリル酸３−(メチル)ブチル、メタクリル酸ヘキシル、メタクリル酸オクチル、メタクリル酸ノニル、メタクリル酸デシル、メタクリル酸ウンデシル、メタクリル酸ドデシル等のメタクリル酸アルキルエステル系モノマー；アクリル酸、メタクリル酸、イタコン酸、マレイン酸等の不飽和カルボン酸系モノマー；アクリロニトリル、マレイン酸エステル、イタコン酸エステル、塩化ビニル、酢酸ビニル、安息香酸ビニル、ビニルメチルエチルケトン、ビニルヘキシルケトン、ビニルメチルエーテル、ビニルエチルエーテルおよびビニルイソブチルエーテル等が挙げられる。好ましくはモノオレフィン系モノマーおよびジオレフィン系モノマーであり、より好ましくはイソプレン、ピペリレン、２−メチル−ブテン−1、2−メチルブテン−2、さらに好ましくはイソプレンである。
肪族モノマーは単独でまたは組み合わせて用いてもよい。
【００３５】
上記のようなモノマーからなる重合体Bの中でも、少なくともスチレンおよび/またはα−メチルスチレンを構成単位として含む重合体Bが好ましい。そのような重合体Bの具体例として、例えば、ポリスチレン、ポリ-α-メチルスチレン、スチレン-α-メチルスチレン共重合体、スチレン−イソプロペニルトルエン共重合体、α-メチルスチレン−イソプロペニルトルエン共重合体、α-メチルスチレン−イソプロペニルトルエン−イソプレン共重合体、スチレン−イソプロペニルトルエン−イソプレン共重合体等が挙げられ、より好ましくはポリ-α-メチルスチレン、ポリスチレン、α-メチルスチレン−イソプロペニルトルエン共重合体、α-メチルスチレン−イソプロペニルトルエン−イソプレン共重合体である。重合体Bにおける重合重量比は特に制限されないが、スチレンおよび/またはα−メチルスチレンの全モノマーに対する割合は25〜100重量％、好ましくは30〜100重量％であることが望ましい。
【００３６】
上記のような重合体Bはさらに、カルボキシル基を有し、かつ重合性二重結合を有する酸モノマーを付加反応させる酸変性を行って用いても良い。重合体Bを酸変性して用いることにより、重合体Bのトナー粒子からの脱離が抑制されるだけでなく、ワックスドメインのトナー粒子からの脱離も有効に抑制される。酸モノマーとしては、アクリル酸、メタクリル酸、マレイン酸、無水マレイン酸からなる群から選択される１種またはそれ以上のモノマーが使用可能である。酸変性に用いる酸モノマーの量は、変性に供される重合体Bに対して0.01〜1重量％が好適である。
【００３７】
重合体Bの使用量は、バインダー樹脂100重量部に対して0.1〜18重量部、好ましくは1〜15重量部、より好ましくは3〜10重量部が望ましい。重合体Bは2種以上組み合わせて使用されてよく、その場合はそれらの合計量が上記範囲内になればよい。
【００３８】
本発明において用いられるバインダー樹脂としては、特に制限されず、静電潜像現像用トナーの分野で公知のバインダー樹脂、例えば、ポリエステル系樹脂、（メタ）アクリル系樹脂、スチレン−（メタ）アクリル系共重合体樹脂、エポキシ系樹脂、COC（環状オレフィン樹脂（例えば、TOPAS-COC（Ticona社製）））等が挙げられる。本発明のトナーは定着時のオイル塗布を必要としない定着装置に適用されるため、特にポリエステル系樹脂が好ましく使用される。
【００３９】
本発明においてポリエステル系樹脂としては、多価アルコール成分と多価カルボン酸成分を重縮合させることにより得られたポリエステル樹脂が使用可能である。
多価アルコール成分のうち２価アルコール成分としては、例えば、ポリオキシプロピレン(2,2)−2,2−ビス(4-ヒドロキシフェニル)プロパン、ポリオキシプロピレン(3,3)−2,2−ビス(4−ヒドロキシフェニル)プロパン、ポリオキシプロピレン(6)−2,2−ビス(4−ヒドロキシフェニル)プロパン、ポリオキシエチレン(2,0)−2,2−ビス(4−ヒドロキシフェニル）プロパン等のビスフェノールＡアルキレンオキサイド付加物、エチレングリコール、ジエチレングリコール、トリエチレングリコール、1,2−プロピレングリコール、1,3−プロピレングリコール、1,4−ブタンジオール、ネオペンチルグリコール、1,4−ブテンジオール、1,5−ペンタンジオール、1,6−ヘキサンジオール、1,4−シクロヘキサンジメタノール、ジプロピレングリコール、ポリエチレングリコール、ポリテトラメチレングリコール、ビスフェノールＡ、水素添加ビスフェノールＡ等が挙げられる。
３価以上のアルコール成分としては、例えば、ソルビトール、1,2,3,6−ヘキサンテトロール、1,4−ソルビタン、ペンタエリスリトール、ジペンタエリスリトール、トリペンタエリスリトール、1,2,4−ブタントリオール、1,2,5−ペンタントリオール、グリセロール、2−メチルプロパントリオール、2−メチル−1,2,4−ブタントリオール、トリメチロールエタン、トリメチロールプロパン、1,3,5−トリヒドロキシメチルベンゼン等が挙げられる。
【００４０】
また、多価カルボン酸成分のうち２価のカルボン酸成分としては、例えば、マレイン酸、フマル酸、シトラコン酸、イタコン酸、グルタコン酸、フタル酸、イソフタル酸、テレフタル酸、シクロヘキサンジカルボン酸、コハク酸、アジピン酸、セバチン酸、アゼライン酸、マロン酸、ｎ−ドデセニルコハク酸、イソドデセニルコハク酸、ｎ−ドデシルコハク酸、イソドデシルコハク酸、ｎ−オクテニルコハク酸、イソオクテニルコハク酸、ｎ−オクチルコハク酸、イソオクチルコハク酸、これらの酸の無水物あるいは低級アルキルエステルが挙げられる。
【００４１】
３価以上のカルボン酸成分としては、例えば、1,2,4−ベンゼントリカルボン酸(トリメリット酸)、1,2,5-ベンゼントリカルボン酸、2,5,7−ナフタレントリカルボン酸，1,2,4−ナフタレントリカルボン酸、1,2,4−ブタントリカルボン酸、1,2,5−ヘキサントリカルボン酸、1,3−ジカルボキシル−2−メチル−2−メチレンカルボキシプロパン、1,2,4−シクロヘキサントリカルボン酸、テトラ(メチレンカルボキシル)メタン、1,2,7,8−オクタンテトラカルボン酸、ピロメリット酸、エンポール三量体酸、これらの酸の無水物、低級アルキルエステル等が挙げられる。
【００４２】
また、本発明においてはポリエステル系樹脂として、ポリエステル樹脂の原料モノマーと、ビニル系樹脂の原料モノマーと、両方の樹脂の原料モノマーと反応するモノマーとの混合物を用い、同一容器中でポリエステル樹脂を得る縮重合反応およびビニル系樹脂を得るラジカル重合反応を並行して行わせて得られた樹脂も好適に使用可能である。なお、両方の樹脂の原料モノマーと反応するモノマーとは、換言すれば縮重合反応およびラジカル重合反応の両反応に使用し得るモノマーである。即ち縮重合反応し得るカルボキシ基とラジカル重合反応し得るビニル基を有するモノマーであり、例えばフマル酸、マレイン酸、アクリル酸、メタクリル酸等が挙げられる。
【００４３】
ポリエステル樹脂の原料モノマーとしては上述した多価アルコール成分および多価カルボン酸成分が挙げられる。
またビニル系樹脂の原料モノマーとしては、例えば、スチレン、ｏ−メチルスチレン、ｍ−メチルスチレン、ｐ−メチルスチレン、α−メチルスチレン、ｐ−エチルスチレン、2,4-ジメチルスチレン、ｐ−tert−ブチルスチレン、ｐ−クロルスチレン等のスチレンまたはスチレン誘導体；エチレン、プロピレン、ブチレン、イソブチレン等のエチレン系不飽和モノオレフィン類；メタクリル酸メチル、メタクリル酸ｎ−プロピル、メタクリル酸イソプロピル、メタクリル酸ｎ−ブチル、メタクリル酸イソブチル、メタクリル酸ｔ−ブチル、メタクリル酸ｎ−ペンチル、メタクリル酸イソペンチル、メタクリル酸ネオペンチル、メタクリル酸３−(メチル)ブチル、メタクリル酸ヘキシル、メタクリル酸オクチル、メタクリル酸ノニル、メタクリル酸デシル、メタクリル酸ウンデシル、メタクリル酸ドデシル等のメタクリル酸アルキルエステル類；アクリル酸メチル、アクリル酸ｎ−プロピル、アクリル酸イソプロピル、アクリル酸ｎ−ブチル、アクリル酸イソブチル、アクリル酸ｔ−ブチル、アクリル酸ｎ−ペンチル、アクリル酸イソペンチル、アクリル酸ネオペンチル、アクリル酸３−(メチル)ブチル、アクリル酸ヘキシル、アクリル酸オクチル、アクリル酸ノニル、アクリル酸デシル、アクリル酸ウンデシル、アクリル酸ドデシル等のアクリル酸アルキルエステル類；アクリル酸、メタクリル酸、イタコン酸、マレイン酸等の不飽和カルボン酸；アクリロニトリル、マレイン酸エステル、イタコン酸エステル、塩化ビニル、酢酸ビニル、安息香酸ビニル、ビニルメチルエチルケトン、ビニルヘキシルケトン、ビニルメチルエーテル、ビニルエチルエーテルおよびビニルイソブチルエーテル等が挙げられる。ビニル系樹脂の原料モノマーを重合させる際の重合開始剤としては、例えば、2,2'−アゾビス(2,4−ジメチルバレロニトリル）、2,2'−アゾビスイソブチロニトリル、1,1'−アゾビス(シクロヘキサン−1−カルボニトリル)、2,2'−アゾビス−4−メトキシ−2,4−ジメチルバレロニトリル等のアゾ系またはジアゾ系重合開始剤、ベンゾイルパーオキサイド、メチルエチルケトンパーオキサイド、イソプロピルパーオキシカーボネート、ラウロイルパーオキサイド等の過酸化物系重合開始剤等が挙げられる。
【００４４】
バインダー樹脂は酸価が5〜50KOHmg/g、好ましくは10〜40KOHmg/gであることが望ましい。特に、ポリエステル系樹脂を用いる場合このような酸価を有する樹脂を用いることによって、カーボンブラックや各種着色剤等の分散性を向上させるとともに、十分な帯電量を有するトナーとすることができる。
【００４５】
本発明においては、特にオイルレス定着用トナーとしての耐オフセット性をさらに向上させるため、ポリエステル系樹脂として軟化点の異なる２種類のポリエステル系樹脂、特に軟化点が80〜120℃の第１ポリエステル系樹脂と軟化点が120〜160℃の第２ポリエステル系樹脂を使用することが好ましい。より好ましい第１ポリエステル系樹脂の軟化点は90〜115℃で、第２ポリエステル系樹脂の軟化点は125〜150℃である。また、トナーの耐熱性のさらなる向上の観点からは第１および第２ポリエステル系樹脂のガラス転移点は50〜75℃、好ましくは55〜70℃とすることが望ましい。このようにバインダー樹脂として2種類の樹脂を使用する場合においては、それらの混合樹脂の酸価が上記範囲内であればよい。
【００４６】
第１ポリエステル系樹脂としては、上述した多価アルコール成分と多価カルボン酸成分を重縮合させて得られたポリエステル樹脂、特に多価アルコール成分としてビスフェノールＡアルキレンオキサイド付加物を主成分とし、多価カルボン酸成分としてテレフタル酸、フマル酸からなる群より選択される少なくとも１種を主成分として得られたポリエステル樹脂が好ましい。第1ポリエステル系樹脂はMnが1800〜7300、好ましくは2000〜5000、Mw/Mnが1.7〜4.6、好ましくは2〜4であることが望ましい。
【００４７】
第２ポリエステル系樹脂としては、少なくとも上述した３価以上のアルコール成分および/または３価以上のカルボン酸成分を含むモノマー成分を重縮合させて得られたポリエステル樹脂、特に２価アルコール成分としてビスフェノールＡアルキレンオキサイド付加物を主成分とし、３価以上のカルボン酸成分としてトリメリット酸を用い、２価カルボン酸成分としてテレフタル酸、フマル酸、ドデセニルコハク酸からなる群より選択される少なくとも１種を主成分として得られたポリエステル樹脂が好ましい。
【００４８】
また、第２ポリエステル系樹脂としては、ポリエステル樹脂の原料モノマーと、ビニル系樹脂の原料モノマーと、両方の樹脂の原料モノマーと反応する両反応性モノマーとの混合物を用い、同一容器中でポリエステル樹脂を得る縮重合反応およびビニル系樹脂を得るラジカル重合反応を並行して行わせて得られたポリエステル系樹脂を用いることが好ましい。このような樹脂は、トナーの強靭性、定着性、耐オフセット性を向上させる観点から好ましい。この場合、第２ポリエステル系樹脂中のビニル系樹脂の含有量は10〜30重量％、好ましくは15〜25重量％が望ましい。
【００４９】
第2ポリエステル系樹脂はMnが2000〜8500、好ましくは2400〜6000、Mw/Mnが8〜40、好ましくは15〜40であることが望ましい。
上記のような第2ポリエステル系樹脂には、テトラヒドロフラン（THF）に不溶な成分を含有させることが、耐高温オフセット性の観点から好ましい。このような観点から、バインダー樹脂中でのTHF不溶成分含有量が0.5〜30重量％、好ましくは5〜20重量％となるように第1および第2ポリエステル系樹脂を用いることが好ましい。
【００５０】
また、耐オフセット性のさらなる向上の観点からは、第１ポリエステル系樹脂と第２ポリエステル系樹脂との重量比は得られるトナーをフルカラートナーとして用いる場合で65：35〜30：70、好ましくは60：40〜35：65とし、モノクロトナーとして用いる場合で20：80〜50：50、好ましくは25：75〜40：60とすることが望ましい。
【００５１】
バインダー樹脂に第1ワックスおよび第2ワックスの少なくとも一方を予め内添するには、バインダー樹脂を合成する際に、バインダー樹脂を合成するためのモノマー中に第1ワックスおよび第2ワックスの少なくとも一方を添加した状態でバインダー樹脂の合成を行えば良い。特に、バインダー樹脂として上記したような第1ポリエステル系樹脂（低分子量体樹脂）と第2ポリエステル系樹脂（高分子量体樹脂）を併用する場合においては、第2ポリエステル系樹脂は第1ポリエステル系樹脂に比べてワックスが入りにくいため、予め第2ポリエステル系樹脂の合成時に第1ワックスおよび第2ワックスの少なくとも一方を添加しておくことが好ましい。具体的には、ポリエステル系樹脂を構成する酸モノマーおよびアルコールモノマー（ならびに所望により用いられるビニル系樹脂の原料モノマー）にワックスを添加した状態で縮重合反応（および所望によりラジカル重合反応）を行えば良い。
【００５２】
本発明で使用される着色剤としては、従来から静電潜像現像用トナーの着色剤として使用されている公知の顔料及び染料が使用可能である。例えば、カーボンブラック、アニリンブルー、カルコイルブルー、クロムイエロー、ウルトラマリンブルー、デュポンオイルレッド、キノリンイエロー、メチレンブルークロリド、銅フタロシアニン、マラカイトグリーンオキサレート、ランプブラック、ローズベンガル、C.I.ピグメント・レッド48：1、C.I.ピグメント・レッド122、C.I.ピグメント・レッド57：1、C.I.ピグメント・レッド184、C.I.ピグメント・イエロー97、C.I.ピグメント・イエロー12、C.I.ピグメント・イエロー17、C.I.ソルベント・イエロー162、C.I.ピグメント・イエロー180、C.I.ピグメント・イエロー185、C.I.ピグメント・ブルー15：1、C.I.ピグメント・ブルー15：3等を挙げることができる。着色剤の含有量としてはバインダー樹脂100重量部に対し2〜15重量部の範囲が好ましい。
【００５３】
本発明のトナーにはワックス分散助剤を含有させてもよい。ワックス分散助剤を添加することによりバインダー樹脂に対するワックスドメインの接着性を向上させることができ、ワックスドメインの遊離（離脱）を防止する効果が向上する。
【００５４】
ワックス分散助剤は、ポリオレフィンにビニル系モノマーがグラフトしたグラフト重合体であって、詳しくは、主鎖としてのポリオレフィンに、側鎖としてのビニル系モノマーからなるビニル系ポリマー鎖を有するものである。
【００５５】
そのようなグラフト重合体は公知の方法によって合成可能である。例えば、オートクレーブ反応槽中でポリオレフィンを適当な有機溶媒に溶解し、窒素置換した後、加熱しながら、そこにビニル系モノマーと適当な重合開始剤との混合溶液を滴下することによって重合し、脱溶すればよい。
【００５６】
ポリオレフィンとしては、パラフィンワックス、パラフィンラテックス、マイクロクリスタリンワックス等のワックス類を好ましく使用することができ、特に、ポリエチレンワックスおよびポリプロピレンワックスを好ましく使用することができる。これらは、1種単独で使用してもよく、2種以上を併用してもよい。ポリオレフィンの前記グラフト重合体における含有量は10〜60重量％が好ましく、10〜40重量％がより好ましい。
【００５７】
ビニル系モノマーとしては、スチレンおよびアルキルスチレン（例えばα−メチルスチレン、p−メチルスチレン等）等のスチレン系モノマー、メチル（メタ）アクリレート、エチル（メタ）アクリレート、ブチル（メタ）アクリレート、2−エチルヘキシル（メタ）アクリレート、ラウリル（メタ）アクリレート、ステアリル（メタ）アクリレート等のアルキル基の炭素数が1〜18のアルキル（メタ）アクリレート、ヒドロキシル（メタ）アクリレート、ヒドロキシプロピル（メタ）アクリレート等のヒドロキシル基含有（メタ）アクリレート、ジエチルアミノエチル（メタ）アクリレート等のアミノ基含有（メタ）アクリレートおよび（メタ）アクリル酸等の（メタ）アクリル系モノマー、アクリロニトリル、メタクリロニトリルモノ−、またはジ−アルキルマレエート等が挙げられる。これらは、1種単独で使用してもよく、2種以上を併用してもよい。
【００５８】
バインダー樹脂がポリエステル系樹脂の場合、グラフト重合体を構成するビニル系モノマーとしてアクリロニトリルを使用することがポリエステル系樹脂に対するワックスドメインの接着性向上の観点からより好ましい。また、バインダー樹脂として、高分子量体樹脂と低分子量体樹脂を併用したバインダー樹脂を使用する場合は、高分子量体樹脂は低分子量体樹脂に比べてワックスドメインの接着性が低いためグラフト重合体を添加することが好ましい。
グラフト重合体は、バインダー樹脂100重量部に対して0.1〜15重量部添加することが好ましい。
【００５９】
本発明のトナーには帯電制御剤や磁性粉等の添加剤を含有させてもよい。
帯電制御剤としては、従来から静電潜像現像用トナーの分野で帯電性を制御するために添加されている公知の帯電制御剤が使用可能である。例えば、フッ素系界面活性剤、サリチル酸金属錯体、アゾ系金属化合物のような含金属染料、マレイン酸を単量体成分として含む共重合体の如き高分子酸、カリックスアレーン化合物、有機ホウ素化合物等を使用することができる。
【００６０】
本発明のトナーは、バインダー樹脂、着色剤、第1ワックス、第2ワックスおよび重合体B、ならびにその他所望の添加剤を溶融混練して冷却した後、粉砕および分級するオイルレス定着用トナーの製造方法において、混練温度をバインダー樹脂の軟化点（℃)(以下、「Bm」と表わすことがある）＋30℃以上、好ましくはBm＋30℃以上、Bm＋120℃以下、より好ましくはBm＋40℃以上、Bm＋100℃以下とすることによって得ることができる。また、混練温度は160〜220℃、好ましくは170〜210℃であることが望ましい。第1ワックスおよび／または第2ワックスは前述したようにバインダー樹脂や着色剤等のトナー材料と同時に混合されるべく用いられても、または予めバインダー樹脂の合成時に添加されるべく用いられてもよい。バインダー樹脂として２種類以上の樹脂を混合して用いる場合においては、それらの混合樹脂の軟化点を「バインダー樹脂の軟化点」とする。
【００６１】
通常、トナーの製造技術においては、混練物中のバインダー樹脂がある程度高い粘度を有している状態で溶融混練することにより、バインダー樹脂に剪断力を作用させて溶融バインダー樹脂によって溶融ワックスを引き千切るようにして、ワックスの分散性を向上させている。このためワックス粒子はバインダー樹脂中に平均分散径が0.5μm以下程度に微分散される。混練温度としては、一般的にはバインダー樹脂の軟化点より20℃程度高い温度、通常140℃程度である。
【００６２】
本発明においては、上記のように混練温度を比較的高く設定し、溶融混練時にバインダー樹脂に剪断力が作用しないように混練物中のバインダー樹脂が低粘度化した条件で溶融混練を行う。このような条件で溶融混練を行うと、トナー粒子中にワックスを高添加することが可能になるとともに複数種類のワックスが一体となった比較的平均分散粒径の大きいドメインが形成される。これは混練物（溶融されたバインダー樹脂）が低粘度化しているため、混練物中で各溶融ワックスが流動しやすくなって、各溶融ワックスが凝集し一体化したドメインが形成されるとともに、剪断力が作用しないためドメインが比較的大粒径化するものと推測される。
【００６３】
本発明においては、混練温度やワックスの合計添加量を変化させることによってトナー粒子中でのワックスドメインの分散粒径を制御することができる。混練温度を上げるまたは合計添加量を多くすると、得られるトナー粒子中でのワックスドメインの分散粒径は一般に大きくなる。一方、混練温度を下げるまたは合計添加量を少なくすると、トナー粒子中でのワックスドメインの分散粒径は一般に小さくなる。
また、トナー粒子中での重合体Bの分散粒径は重合体Bの添加量を変化させることによって制御することができる。当該添加量を多くすると、一般に重合体Bの分散粒径は大きくなる。一方、当該添加量を少なくすると、一般に重合体Bの分散粒径は小さくなる。
トナーの体積平均粒径は4〜10μm、好ましくは5〜8μmが好適である。
【００６４】
以上のような本発明のトナーからなるトナー像を定着させるに際しては、加熱部材および該加熱部材に圧接して配置された加圧部材または加圧加熱部材のいずれにも定着オイルを塗布または含浸させることなく、加熱部材と加圧部材または加圧加熱部材との圧接部に、トナー像を担持した記録シート（例えば、用紙）を通過させることを含むオイルレス定着方法を採用することが好適であり、特に加熱部材からの用紙の分離を有効に達成する観点から圧接部のニップ構成が上に凸となっていることが好ましい。さらに加熱部材は用紙と加熱部材との分離性のさらなる向上の観点から、表面がフッ素系樹脂、例えばPFA（四フッ化エチレン−パーフルオロアルキルビニルエーテル共重合体）、ポリ四フッ化エチレン、ポリフッ化ビニリデン等から形成されていることが好ましい。
【００６５】
そのような定着方法を採用した定着装置として、例えば図1に概略的に示す定着装置を好ましく用いることができる。図1の定着装置は加熱部材として加熱ローラ11、加圧部材として加圧ローラ12を用いている。詳しくは、加熱ローラ11、加熱ローラに圧接される加圧ローラ12、定着後のシートを加熱ローラから分離するための分離爪13、加熱ローラ表面をクリーニングするためのクリーニングウェブ14、クリーニングウェブが巻回されたウェブローラ15、クリーニングウェブを巻き取る巻取りローラ16を備えている。加熱ローラ11は、通常アルミ芯金17上に弾性体層18および表層19を有しており、アルミ芯金内部にヒーター20を備えている。加圧ローラ12は、通常、アルミ芯金21上に弾性体層22および表層23を有している。弾性体層（18,22）の材質は特に制限されないが、好ましくはシリコーンゴムである。表層（19,23）の材質は特に制限されないが、好ましくはフッ素系樹脂、特にPFAである。
図1において加熱ローラ11と加圧ローラ12の圧接部には、加熱ローラ側（上側）に凸形状となるニップ24が形成されている。当該圧接部に、トナー像26を担持した記録シート25を図中右から左に通過させることによって定着が行われる。
【００６６】
【実施例】
（樹脂1、2、4〜8、11および12（St/Ac複合ワックス内添ポリエステル樹脂）の製造例）
ビニル系樹脂の単量体としてスチレンおよびブチルアクリレート（StAcモノマー）および重合開始剤としてジクミルパーオキサイドを表1に示すモル比で滴下ロートに入れた。次に、ポリエステルの単量体（PESモノマー）として表1に示すモル比でアルコール成分および酸成分、さらには酸成分の中でも両反応性化合物としてフマル酸を追加し、エステル化触媒としてジブチルパーオキシドおよび表1に示したワックスを表1に示す添加量（仕込モノマーに対する重量％）で、温度計、ステンレス製撹拌棒、流下式コンデンサー、および窒素導入管を取り付けたガラス製4つ口フラスコに入れ、マントルヒーター中で窒素雰囲気下160℃に加熱撹拌しつつ、滴下ロートより予め作製しておいたビニル系樹脂の単量体および重合開始剤を滴下した。その後、一定の温度160℃に保持したまま付加重合反応を熟成させた後、230℃に昇温して縮重合反応を行わせた。そして、この反応の進行は、酸価もしくは軟化点を測定することにより追跡した。所定の酸価もしくは軟化点に達した時点でそれぞれ反応を終了させて室温まで冷却し、ポリエステル樹脂を得た。各樹脂におけるPESモノマーとStAcモノマーとの重量比率は表1に示す通りであった。
BPA-PO：ビスフェノールAプロピレンオキサイド付加物
BPA-EO：ビスフェノールAエチレンオキサイド付加物
TPA：テレフタル酸
TMA：トリメリット酸
DSA：ドデセニルコハク酸
St：スチレン
BA：ブチルアクリレート
【００６７】
（樹脂3、9および10（ワックス未添加樹脂）の製造例）
温度計、ステンレス製撹拌棒、流下式コンデンサー、および窒素導入管を取り付けたガラス製4つ口フラスコに、表1に示すモル比でアルコール成分および酸成分を重合開始剤（ジブチル錫オキシド）とともに入れた。これをマントルヒーター中において窒素気流下にて、撹拌加熱しながら加熱することにより反応させた。そして、この反応の進行は、酸価もしくは軟化点を測定することにより追跡した。所定の酸価もしくは軟化点に達した時点でそれぞれ反応を終了させて室温まで冷却し、ポリエステル樹脂を得た。
【００６８】
上記製造方法で得られた樹脂1〜12のモノマー比率および物性を表1および表2に示す。各ポリエステル樹脂は1mm以下に粗砕して以下のトナーの製造で用いた。
【００６９】
【表１】

【００７０】
【表２】

【００７１】
（ワックス）
本実施例で用いたワックスを表3に示す。
【表３】

【００７２】
（重合体B1の製造例）
α−メチルスチレン（純度99.8％）500gおよびトルエン500gを三つ口フラスコに入れ、撹拌下に三弗素ホウ素フェノール錯体を少量ずつ添加し、ドライアイス・アセトン浴で冷却しながら20℃で3時間反応させた。次いで、アルカリを添加して触媒を失活させて除去し、溶媒と未反応モノマーとを追い出すために濃縮し、α−メチルスチレン単一重合体を得た。これを重合体B1とする。
【００７３】
（重合体B2の製造例）
スチレン（純度99.9％）500gおよびトルエン500gを三つ口フラスコに入れ、撹拌下に三弗素ホウ素フェノール錯体を少量ずつ添加し、ドライアイス・アセトン浴で冷却しながら20℃で3時間反応させた。次いで、アルカリを添加して触媒を失活させて除去し、溶媒と未反応モノマーとを追い出すために濃縮し、スチレン単一重合体を得た。これを重合体B2とする。
【００７４】
（重合体B3の製造例）
イソプロペニルトルエン（純度98％）250g、α−メチルスチレン（純度99.8％）250g、およびトルエン500gを三つ口フラスコに入れ、撹拌下に三弗素ホウ素フェノール錯体を少量ずつ添加し、ドライアイス・アセトン浴で冷却しながら、3時間反応させた。次にNaOH水溶液を添加し、激しく撹拌して触媒を分解した後、水相を分離して油状の重合物を得た。さらに油状の重合物を中性になるまで水洗した後、未反応油および溶媒を加熱減圧留去し、白色塊状の重合体を得た。この重合体に無水マレイン酸0.5gおよびジ−tert−ブチルペルオキシド0.5gを添加し、180〜210℃に加熱し、撹拌下に3時間反応させて、更に200℃で15〜30分、20mmHgで減圧処理し、上記重合体B3を得た。
【００７５】
（重合体B4の製造例）
イソプロペニルトルエン（純度99.8％）200g、α−メチルスチレン（純度99.8％）200g、石油ナフサの熱分解によって得られるC5系石油留分（イソプレン）120g、およびトルエン500gを三つ口フラスコに入れ、撹拌下に三弗素ホウ素フェノール錯体を少量ずつ添加し、ドライアイス・アセトン浴で冷却しながら、3時間反応させた。次にNaOH水溶液を添加し、激しく撹拌して触媒を分解した後、水相を分離して油状の重合物を得た。さらに油状の重合物を中性になるまで水洗した後、未反応油および溶媒を加熱減圧留去し、白色塊状の共重合体を得た。この重合体に無水マレイン酸0.5gおよびジ−tert−ブチルペルオキシド0.5gを添加し、180〜210℃に加熱し、撹拌下に3時間反応させて、更に200℃で15〜30分、20mmHgで減圧処理し、上記共重合体B4を得た。
【００７６】
（重合体B5の製造例）
反応時間を2時間とした以外は、重合体B2と同じ製法で重合体B5を得た。
（重合体B6の製造例）
反応時間を4.5時間とした以外は、重合体B1と同じ製法で重合体B6を得た。
【００７７】
上記製造方法で得られた重合体B1およびB2の物性を表4に示す。
【表４】

【００７８】
実施例1
トナーを製造するにあたって、使用する樹脂は、樹脂1と樹脂3を重量比64.5：40で、ヘンシェルミキサーにてドライブレンドしたものを使用した。このブレンドした樹脂とマゼンタ顔料（C.I.ピグメントレッド184）とを樹脂（樹脂がワックス成分を含有するときは樹脂成分のみ）：顔料が7：3の重量比になるように加圧ニーダに仕込み混練した。得られた混練物を冷却後フェザーミルにより粉砕し顔料マスターバッチを得た。上記樹脂と上記顔料マスターバッチを、樹脂（樹脂がワックス成分を含有するときは樹脂成分のみ）：顔料が100：4の重量比になるように用い、これらに樹脂（樹脂がワックス成分を含有するときは樹脂成分のみ）100重量部に対して表5に示すWAX2を1.0重量部、重合体B1を4.0重量部添加し、ヘンシェルミキサーで混合した後、混合物を二軸混練装置（TEM50、東芝機械社製）混練温度180℃で混練した。得られた混練物を冷却した後、フェザーミルで粗粉砕後、機械式粉砕機A（クリプトロン粉砕機、川崎重工業社製）にて粉砕後、更に循環式粉砕機B（ジェットミル粉砕機、日本ニューマチック工業社製）で微粉砕し、機械式分級機C（ATP分級機、アルピネ社製）にて分級し、更にもう一度同様に分級し、体積平均粒径約7μmのトナーを得た。そして、このトナー粒子に対して、外添剤として疎水性シリカ（ヘキストジャパン社製；H2000）を0.9重量％、疎水性チタニア（チタン工業社製；STT30A）を0.9重量％、チタン酸ストロンチウム2.5重量％の割合で加え、これらをヘンシェルミキサーにより混合して添加処理を行い、マゼンタトナーを得た。
【００７９】
実施例2〜26および比較例1〜9
表5または6に示すようなトナー組成となるように各種材料を用いたこと、および混練温度を表5または6に示す値に設定したこと以外、実施例1と同様の方法により、トナーを得た。
【００８０】
【表５】

【００８１】
【表６】

【００８２】
得られたトナーを以下の項目について評価し、結果を表7および8に示した。
＜ワックスドメイン径および重合体Bのドメイン径＞
トナー粒子をミクロトームによりスライスした後、TEM（透過型電子顕微鏡）にて10000倍の写真を撮影し、この写真画像をイメージアナライザー（ルーゼックス5000；日本レギュレータ社製）に取り込んで各ドメイン径の粒度分布を測定した。ドメインが完全球形で無い場合は、そのドメインの断面積の円相当粒径で算出した。
【００８３】
＜耐熱性＞
トナー10gを50℃の高温下に24時間放置後、そのトナーを目視で確認することにより行なった。
○：凝集トナーがなく、全く問題なし；
△：軽い軟凝集が存在するが、軽い力ですぐ解れ、実用上問題ないもの；
×：強い凝集塊が存在し、容易には解れないもので実用上問題あり。
【００８４】
＜分離性・耐オフセット性能＞
テストパターンは、3色重ね時のトナー付着量を想定して、A4縦通紙で先端5mmに幅36mmのベタ帯画像（付着量12g/m²）を印字した未定着画像を作成した。この未定着画像を以下の定着装置1および2を用いて様々な定着温度で定着させ、分離可能／非オフセット温度域を求めた。当該温度域は、加熱ローラからの紙の分離が良好に行われ、かつオフセット現象が発生しない定着温度範囲をいう。
【００８５】
定着装置1は図1に示す装置であって、フッ素系表層剤構成のソフトローラタイプのものである。詳しくは、加熱ローラ11は、外径40mmで、アルミ芯金17上にシリコーンゴムからなる厚さ1.5mmの弾性体層18およびPFA（四フッ化エチレン−パーフルオロアルキルビニルエーテル共重合体）表層19を有しており、アルミ芯金内部にヒーター20を備えている。加圧ローラ12は、外径35mmで、アルミ芯金21上にシリコーンゴムからなる厚さ3mmの弾性体層22およびPFA表層23を有している。加熱ローラ11と加圧ローラ12の圧接部には、加熱ローラ側に凸形状となるニップ（ニップ幅7mm）24が形成されている。
【００８６】
定着装置2は、デジタル複写機Di350（ミノルタ社製）の定着装置であって、テフロンハードローラ方式で分離爪ありのタイプのものである。
いずれの装置も定着ローラのクリーニング用のウェーブローラを配した構成としたが定着オイルは使用せずに実験を行った。使用ペーパー及び通紙方向は、分離性に不利な64g/m²紙のY目の縦通紙で行った。定着温度範囲120〜220℃で評価した。定着装置周速120mm/sec。
○：分離可能／非オフセット温度域が50℃以上であった；
△：分離可能／非オフセット温度域が30℃以上50℃未満であった；
×：分離可能／非オフセット温度域が30℃未満であった。
【００８７】
＜10k実機ランニング＞
現像剤は、各評価トナーとキャリア（シリコーン−アクリル樹脂でコートしたフェライトキャリア35μm）をトナー混合比8wt％になるように調合し、架台にて混合時間30分スターターを作成し、カラー複写機CF-900（ミノルタ社製）で1万枚ランニングを行い、画像上のフィルミングに関する実用上の不具合を確認した。
○：フィルミングの発生なし；
△：若干フィルミングが生じるが、実用上問題なし；
×：実用上問題点があった。
【００８８】
＜製造性＞
トナーを製造するにあたり、各装置に付着した平均トナー量を投入量と回収量から算出した。
○：付着量は投入量の5％未満であった；
△：付着量は投入量の5％以上、10％未満であった；
×：付着量は投入量の10％以上であった。
【００８９】
【表７】

【００９０】
【表８】

【００９１】
本発明において用いられた他の測定方法を以下に示す。
＜ガラス転移点（Tg）測定法＞
示差走査熱量計（DSC-200：セイコー電子社製）を用い、測定する試料10mgを精密に秤量して、これをアルミニウムパンに入れ、リファレンスとしてアルミナをアルミニウムパンに入れたものを用い、昇温速度30℃/minで常温から200℃まで昇温させた後、これを冷却し、昇温速度10℃/minで20〜120℃の間で測定を行い、この昇温過程で30〜90℃の範囲におけるメイン吸熱ピークのショルダー値をTgとした。
【００９２】
＜ワックスピーク測定法＞
示差走査熱量計（DSC-200：セイコー電子社製）を用い、測定する試料10mgを精密に秤量して、これをアルミニウムパンに入れ、リファレンスとしてアルミナをアルミニウムパンに入れたものを用い、昇温速度30℃/minで常温から200℃まで昇温させた後、これを冷却し、昇温速度10℃/minで20〜185℃の間で測定を行い、この昇温過程でワックスに起因する吸熱カーブのピークの温度を、それぞれのWAXDSCピーク温度とした。
【００９３】
＜樹脂／トナー軟化点（Tm）測定法＞
フローテスター（CFT-500；島津製作所製）を用い、測定する試料1.5gを秤量し、h1.0mm×φ1.0mmのダイを使用し、昇温速度3.0℃/min、予熱時間180秒、荷重30kg、測定温度範囲80〜140℃の条件で測定を行い、上記の試料が1/2流出したときの温度を軟化点とした。
【００９４】
＜Mn、Mw測定方法＞
ゲルパーミエーションクロマトグラフィー（807-IT型；日本分光工業社製）を用いて測定した。カラムを40℃に保ちながら、キャリア溶液としてテトラヒドロフランを1kg/cm²で流し、測定する試料30mgをテトラヒドロフラン20mlに溶解し、この溶液0.5mgを上記のキャリア溶媒と共に装置内に導入して、ポリスチレン換算により求めた。
【００９５】
＜酸価測定方法＞
10mgの試料をトルエン50mlに溶解し、0.1％のブロムチモールブルーとフェノールレッドの混合指示薬を用いて、予め標定されたN/10水酸化カリウム／アルコール溶液で滴定し、N/10水酸化カリウム／アルコール溶液の消費量から算出した値である。
【００９６】
＜水酸価＞
水酸価は、秤量された試料を無水酢酸で処理し、得られたアセチル化合物を加水分解し、遊離する酢酸を中和するために必要な水酸価化カリウムmgで表した。
【００９７】
＜THF不溶分含有量の測定方法＞
THF不溶分含有量はテトラヒドロフランを溶媒とした10時間のソックスレー抽出により測定した。
【００９８】
【発明の効果】
本発明によりワックスを比較的多量で含有するトナーを提供できる。当該トナーはワックスの添加によるトナー特性、すなわち耐オフセット性、分離性の向上が顕著であり、耐熱保管性、耐フィルミング性、および製造性にも優れている。
【図面の簡単な説明】
【図１】 本発明の定着方法を採用した定着装置の一例の概略構成図を示す。
【符号の説明】
11：加熱ローラ、12：加圧ローラ、13：分離爪、14：クリーニングウェブ、15：ウェブローラ、16：巻取りローラ、17：芯金、18：弾性体層、19：表層、20：ヒーター、21：芯金、22：弾性体層、23：表層、24：ニップ、25：記録シート、26：トナー像。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrostatic latent image developing toner, particularly an oilless fixing toner suitable for being applied to an oilless fixing device in which a fixing member such as a heating member or a pressure member does not require fixing oil. The present invention relates to a manufacturing method and a fixing method.
[0002]
[Prior art]
Conventionally, a contact heating fixing method such as a heat roll fixing method has been widely adopted as a toner fixing method. A fixing device used for a heat roll fixing method includes a heating roll and a pressure roll, and passes a recording sheet carrying a toner image through a pressure contact portion (nip portion) between the heating roll and the pressure roll. As a result, the toner image is melted and fixed on the recording sheet.
[0003]
As described above, in the contact heating fixing method represented by the heat roll fixing method, the surface of the heating member (for example, a heating roll) of the contact heating fixing device is brought into contact with the toner image on the recording sheet for fixing. It is necessary to prevent an offset phenomenon in which a part of the toner image adheres and is transferred to the next recording sheet and becomes dirty.
[0004]
In order to prevent the offset phenomenon, a technique for applying or impregnating a fixing oil such as silicone oil to a heating roll or a pressure roll of a fixing device is known, but in a monochrome image forming apparatus, the fixing device can be downsized. From the viewpoint of cost reduction, an oilless fixing device in which a fixing oil applying mechanism is omitted and a fixing device in which the amount of fixing oil applied is reduced are employed. When such a fixing device is employed, wax as an anti-offset agent is added to the toner.
[0005]
In addition to normal offset prevention wax, different types of toner can be used to prevent toner smearing and smearing due to rubbing during double-sided copying, or to improve the function of toner, such as improving low-temperature fixability. A technique for adding the wax is also known. Thus, in order to further improve the offset resistance and other functions, it is effective to increase the content of various waxes in the toner particles.
[0006]
On the other hand, in an image forming apparatus that forms a full color image using a plurality of color toners, conventionally, a heating roll or a pressure roll is coated or impregnated with a fixing oil such as silicone oil, thereby preventing an offset phenomenon and a heating roll. And / or separation of the recording sheet from the pressure roll has been ensured. Oil-less fixing of full color toners used in such full color image forming apparatuses is also being studied. In the case of normal monochrome image reproduction toner, since a resin having high viscoelasticity can be used as a binder resin, the intermolecular cohesive force at the time of toner melting (fixing) is high, and the wax content is small. In addition, separation from the fixing roller and offset resistance can be secured. However, in the case of a full color toner, if a binder resin having high viscoelasticity is used, the translucency, glossiness, and color reproducibility become insufficient. For this reason, in a full-color toner, the proportion of offset resistance and separability depending on the wax is high, and it is necessary to increase the wax content.
[0007]
[Problems to be solved by the invention]
However, the wax is generally incompatible with the binder resin, and even if the wax content is increased in an attempt to increase the wax content, the toner is used in the process of pulverizing the kneaded product at the time of toner production. The amount of the wax released from the particles increased, and the amount of the wax actually contained in the toner particles was reduced from that at the time of blending the raw materials, and the wax could not be effectively contained in the toner particles. For this reason, the present situation is that the effect of improving the toner characteristics (offset resistance, separation between the fixing member (heating member and / or pressure member) and the recording sheet) due to the addition of wax cannot be sufficiently exhibited. Further, when the amount of free wax increases, the heat resistant storage property of the toner decreases and filming occurs on the image. Further, when the amount of the wax is increased, the amount of toner adhering to the apparatus during the toner manufacturing process increases, resulting in a problem that the manufacturing efficiency (manufacturability) decreases.
[0008]
In order to prevent the generation of free wax, attempts have been made to disperse the wax in the toner particles with a relatively small particle size in order to suppress the exposure of the wax to the toner particle surface. The effect of improving the toner characteristics by the addition could not be sufficiently exhibited.
[0009]
The present invention has been made in view of the above circumstances, and is an oilless fixing toner that can sufficiently exhibit the effect of improving the toner characteristics by the addition of wax and that is excellent in manufacturability, a method for producing the toner, and the toner. It is an object of the present invention to provide a fixing method.
That is, the present invention is an oil having sufficiently excellent offset resistance, separation between the fixing member (heating member and / or pressure member) and the recording sheet, heat resistant storage property, filming resistance, and excellent manufacturability. An object of the present invention is to provide a toner for less fixing, a method for producing the toner, and a fixing method using the toner.
[0010]
[Means for Solving the Problems]
In the present invention, at least a binder resin, a colorant, a first wax, a second wax of a type different from the first wax, a weight average molecular weight of 1000 to 3000, and a weight average molecular weight / number average molecular weight of 1.0 to 2.0. An oil-less fixing toner obtained by melt-kneading polymer B and then pulverizing, wherein the domain in which the first wax and the second wax are integrated in the toner particles and the polymer B are dispersed, Average dispersed particle size d of the domain ₁ (Μm) and the average dispersed particle diameter d of the polymer B ₂ (Μm) and the following relationship:
0.01 <d ₂ <0.5 <d ₁ <3.0
The present invention relates to an oilless fixing toner characterized by satisfying
[0011]
The present invention also includes at least a binder resin, a colorant, a first wax, a second wax of a different type from the first wax, and a weight average molecular weight of 1000 to 3000 and a weight average molecular weight / number average molecular weight of 1.0 to 2.0. A method for producing an oilless fixing toner in which a polymer B is melt-kneaded, cooled, pulverized and classified, and the kneading temperature is set to be a softening point of the binder resin + 30 ° C. or higher and a softening point of the binder resin + 120 ° C. or lower. The present invention relates to a method for producing an oilless fixing toner.
[0012]
The present invention also provides a heating member having a fluororesin surface and a pressure member disposed in pressure contact with the heating member or a pressure heating member without applying or impregnating fixing oil. An oilless fixing method for fixing by passing a paper carrying a toner image through a pressure contact portion with a pressure member or a pressure heating member, wherein the toner image is formed from the oilless fixing toner, and the pressure contact portion The present invention relates to an oilless fixing method characterized in that the nip configuration is convex upward.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The toner particles constituting the oil-less fixing toner of the present invention comprise at least a binder resin, a colorant, a first wax, a second wax, and a specific polymer B. Among the toner particles, the first wax and the second wax And the polymer B are dispersed. That is, in the present invention, the toner particles have a sea-island structure, and the domain and the polymer B in which the first wax and the second wax are integrated in the binder resin as the main component (sea component) of the toner particles. It is decentralized.
[0014]
In the present invention, the average dispersed particle size d of the wax domain ₁ (Μm) and average dispersion particle diameter d of polymer B ₂ (Μm) and the following relationship;
0.01 <d ₂ <0.5 <d ₁ <3.0
Satisfied. Preferably d ₁ Is not less than 0.75 μm and not more than 2.0 μm, and d ₂ Is 0.05 μm or more and 0.3 μm or less.
[0015]
In the present invention, the toner particles in which such a wax domain and polymer B domain are formed can contain a relatively large amount of wax, contain almost no free wax, and further contain the wax domain by mixing in the actual machine. Since the separation (release) from the toner particles is remarkably suppressed, the toner has an effect of improving the toner characteristics by adding wax, that is, offset resistance, fixing member (heating member and / or pressure member) and recording sheet. It is considered that excellent heat storage stability and filming resistance can be ensured while sufficiently exhibiting the effect of improving the separation property. At the time of fixing the toner image, in the conventional toner particles in which the wax fine particles are finely dispersed, a relatively large number of the wax fine particles need to be individually moved to the surface of the toner particles. Since it is dispersed with a relatively large particle size, it can be efficiently and instantaneously moved to the toner particle surface. This is also considered to be one of the reasons that the effect of improving the toner characteristics by adding the wax can be sufficiently exhibited.
[0016]
It is considered that the release (release) of the wax domains from the toner particles is remarkably suppressed by the addition of the polymer B. That is, when the polymer B described later is used, the polymer B constitutes a pulverization interface in the production process, and as a result is exposed on the surface of the toner particles, it is considered that the detachment of the wax domain can be more effectively reduced. In addition, the use of the polymer B not only further improves the heat resistance storage property and filming resistance of the toner, but also reduces the adhesion of the toner to the apparatus during the toner production, thereby improving the toner production efficiency (manufacturability). The effect of improving is also acquired.
[0017]
d ₁ When the thickness is 3.0 μm or more, the wax domain is remarkably detached, so that not only the heat resistant storage property and filming resistance are lowered, but also the offset resistance performance, separation property, and manufacturability are also lowered. d ₁ When the particle size is 0.5 μm or less, the domain particle size is too small, and the wax cannot efficiently and instantaneously move to the toner particle surface at the time of fixing. d ₂ If it is 0.5 μm or more, the dispersion state of the polymer B in the binder resin becomes non-uniform, so that the heat resistant storage property, the filming resistance, the offset resistance property, the separation property and the manufacturability are lowered. d ₂ If it is 0.01 μm or less, it becomes difficult to form a pulverization interface at the time of production, and the productivity is particularly lowered. In addition, the effect of reducing the desorption of the wax domain is lowered, and the heat resistant storage property, filming resistance, offset resistance and separation property are lowered.
[0018]
In this specification, the average dispersed particle diameter of the wax domain and the average dispersed particle diameter of the polymer B are obtained by slicing the toner particles with a microtome and then taking a 10000 times photograph with a TEM (transmission electron microscope). The value obtained by taking a photographic image into an image analyzer (Luzex 5000; manufactured by Nippon Regulator Co., Ltd.) and measuring the particle size distribution of each dispersed particle size is used, but it does not have to be measured by the above method. Any method may be adopted as long as the average dispersed particle size of each dispersed particle in the toner particles can be obtained. In the above method, when the dispersed particles are not completely spherical, the calculation is performed by the equivalent circle diameter of the cross-sectional area of the particles. In the photographic image obtained by the above method, the dispersed particles of the wax domain and the dispersed particles of the polymer B can be easily distinguished from each other by controlling the dyeing treatment conditions.
[0019]
The formation of a domain in which multiple types of wax are integrated means that after slicing the toner particles with a microtome, a 10000-times photograph is taken with a TEM, and each wax domain has a difference in the type of wax. Thus, it can be confirmed by observing that it is composed of a plurality of regions having different crystal structures.
[0020]
The first wax used in the present invention is a wax that is incompatible with the binder resin and is known in the field of toner for developing electrostatic latent images. For example, a polyolefin wax such as polyethylene wax and polypropylene wax, Examples thereof include acid-modified waxes such as oxidized polyethylene wax and oxidized polypropylene wax, natural waxes such as carnauba wax and rice wax, montan wax, Fischer-Tropsch wax, paraffin wax, and polymer alcohol wax. Preferred are polyethylene wax, oxidized polyethylene wax, paraffin wax, carnauba wax, rice wax, montan wax, Fischer-Tropsch wax, polymeric alcohol wax, and more preferred is polyethylene wax.
[0021]
The acid-modified wax can be obtained by subjecting a polyolefin such as polyethylene and polypropylene to an addition reaction of an acid monomer having a carboxyl group and a polymerizable double bond. As the acid monomer, one or more monomers selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, and maleic anhydride can be used. The acid value of the acid-modified wax is 1 to 60 KOHmg / g, preferably 3 to 30 KOHmg / g.
[0022]
The first wax preferably has a DSC peak temperature of 65 to 105 ° C, preferably 70 to 100 ° C. As such first wax, commercially available PW400 (polyethylene wax; manufactured by Toyo Petrolite Co., Ltd.), PW500 (polyethylene wax; manufactured by Toyo Petrolite Co., Ltd.), and PW655 (polyethylene wax; manufactured by Toyo Petrolite Co., Ltd.) can be used.
[0023]
The second wax is a known wax that is incompatible with the binder resin, and is a different type of wax from the first wax used together. Here, “different types” means different materials (substance names). The second wax is preferably incompatible with the first wax. Specific examples include the same waxes as the first wax. Preferred are polyethylene wax, oxidized polyethylene wax, polypropylene wax, oxidized polypropylene wax and the like, and more preferred is polypropylene wax.
[0024]
The second wax has a DSC peak temperature of 110 to 150 ° C, preferably 130 to 145 ° C. As such second wax, commercially available 100TS (oxidized polypropylene wax; manufactured by Sanyo Chemical Industries), 550P (polypropylene wax; manufactured by Sanyo Chemical Industries), and 660P (polypropylene wax; manufactured by Sanyo Chemical Industries) can be used. is there.
[0025]
At least one of the first wax and the second wax is preferably an acid-modified wax (oxidized polypropylene wax or oxidized polyethylene wax). By using the acid-modified wax, it is possible to effectively prevent the separation of the wax domain, and it is possible to effectively obtain the effect of improving the toner characteristics by adding the wax without reducing the productivity.
[0026]
The first wax and / or the second wax may be added when the toner material such as the binder resin or the colorant is mixed, but at least one of the first wax and the second wax should be added when the binder resin is synthesized. Is preferred. By adding at least one of the first wax and the second wax to the binder resin in advance, a domain having a uniform diameter can be easily formed, and the effect of improving the toner characteristics by adding the wax can be obtained more effectively. it can.
[0027]
The total addition amount of the first wax and the second wax is 3 to 15 parts by weight, preferably 4 to 12 parts by weight, based on 100 parts by weight of the binder resin. More preferably, the addition amount of the first wax is 2.5 to 10 parts by weight, and the addition amount of the second wax is 0.5 to 5 parts by weight. In particular, when the first wax and the second wax are highly filled, that is, when the total addition amount of these waxes is 5 parts by weight or more with respect to 100 parts by weight of the binder resin, the first wax as described above. It is preferable that at least one of the second wax and the second wax is added during the synthesis of the binder resin. The present invention does not prevent the toner particles from containing three or more kinds of waxes, and in this case, the total addition amount of all the waxes may be within the above range. In that case, the wax domain may be formed by integrating the three or more kinds of waxes, and the average dispersed particle size (d of the domain (d ₁ ') D ₁ D instead of ₂ And satisfy the above relationship.
[0028]
The polymer B used in the present invention has a weight average molecular weight (Mw) of 1000 to 3000, preferably 1000 to 2800, and a weight average molecular weight / number average molecular weight (Mw / Mn) of 2.0 or less, preferably 1.0 to 2.0. It is a polymer. When Mw exceeds 3000, the dispersibility of the polymer B in the binder resin is lowered, so that the polymer B becomes difficult to be exposed on the toner particle surface, and the desorption of the wax domain cannot be suppressed. , Filming resistance, offset resistance performance, separability and manufacturability are reduced. When Mw is less than 1000, the glass transition point of the polymer B is lowered, and the heat-resistant storage property is lowered.
[0029]
As a result, the polymer B is incompatible with the first wax, the second wax, and the binder resin described below. Therefore, in the toner of the present invention, in the binder resin as the sea component, the polymer B is dispersed as an island component independently of the wax domain in which the first wax and the second wax are integrated.
[0030]
The glass transition point (Tg) of the polymer B is 50 ° C. or higher, preferably 55 to 85 ° C., more preferably 60 to 80 ° C. The softening point of the polymer B is 110 to 150 ° C, preferably 120 to 145 ° C.
[0031]
As a kind of the polymer B, even if the polymer B is melt-kneaded with the first wax, the second wax, and the binder resin described later, they are not compatible with any material and have the above-described Mw and Mw / Mn. As long as it is not particularly limited, for example, a known homopolymer or copolymer of an aromatic monomer and / or an aliphatic monomer can be used.
[0032]
As an aromatic monomer, general formula (1);
[Chemical 1]

(Where R ¹ , R ² , R ³ And R ⁴ Each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, or an n-butyl group, preferably a hydrogen atom, a chlorine atom, or a bromine atom. Or a methyl group) and a general formula (2);
[Chemical 2]

(Where R ⁵ , R ⁶ And R ⁷ Are each independently a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, or an n-hexyl group, Preferably, it is a hydrogen atom, a chlorine atom, a bromine atom, or a methyl group).
[0033]
Specific examples of the styrenic monomer include, for example, styrene, vinyl toluene, α-methyl styrene, isopropenyl toluene, β-methyl styrene, 1-propenyl toluene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, α-chlorostyrene, β-chlorostyrene, o-bromostyrene, m-bromostyrene, p-bromostyrene, α-bromostyrene, β-bromostyrene, and the like, preferably styrene, vinyltoluene, α-methylstyrene , Isopropenyltoluene, β-methylstyrene, 1-propenyltoluene, more preferably styrene, vinyltoluene, α-methylstyrene, isopropenyltoluene, and still more preferably styrene, α-methylstyrene, isopropenyltoluene.
Specific examples of the indene monomer include indene, methylindene, ethylindene and the like, and among these, indene is particularly preferable.
Aromatic monomers may be used alone or in combination.
[0034]
Specific examples of the aliphatic monomer are not particularly limited as long as they can be polymerized with the aromatic monomer. For example, isoprene, piperylene, 1,3-butadiene, 1,3-pentadiene, 1,5-hexadiene, 2, Diolefin monomers such as 3-dimethyl-1,3-butadiene, chloroprene, 2-bromo-1,3-butadiene; ethylene, propylene, butylene, isobutylene, 2-methyl-butene-1, 2-methylbutene-2, etc. Monoolefin monomers of: methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-pentyl acrylate, isopentyl acrylate, Neopentyl acrylate, 3- (methyl) butyl acrylate, hexyl acrylate, octyl acrylate, acrylic Acrylic acid alkyl ester monomers such as acid nonyl, decyl acrylate, undecyl acrylate, dodecyl acrylate; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate , T-butyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, neopentyl methacrylate, 3- (methyl) butyl methacrylate, hexyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, undecyl methacrylate, Methacrylic acid alkyl ester monomers such as dodecyl methacrylate; unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid; acrylonitrile, maleic acid Examples include stealth, itaconic acid ester, vinyl chloride, vinyl acetate, vinyl benzoate, vinyl methyl ethyl ketone, vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether. Monoolefin monomers and diolefin monomers are preferred, isoprene, piperylene, 2-methyl-butene-1, 2-methylbutene-2, and more preferred isoprene.
Aliphatic monomers may be used alone or in combination.
[0035]
Among the polymers B composed of the above monomers, a polymer B containing at least styrene and / or α-methylstyrene as a constituent unit is preferable. Specific examples of such a polymer B include, for example, polystyrene, poly-α-methylstyrene, styrene-α-methylstyrene copolymer, styrene-isopropenyltoluene copolymer, α-methylstyrene-isopropenyltoluene copolymer. Polymer, α-methylstyrene-isopropenyltoluene-isoprene copolymer, styrene-isopropenyltoluene-isoprene copolymer, and the like, more preferably poly-α-methylstyrene, polystyrene, α-methylstyrene-iso A propenyltoluene copolymer and an α-methylstyrene-isopropenyltoluene-isoprene copolymer. The polymerization weight ratio in the polymer B is not particularly limited, but the ratio of styrene and / or α-methylstyrene to the total monomer is 25 to 100% by weight, preferably 30 to 100% by weight.
[0036]
The polymer B as described above may further be used after acid modification by addition reaction of an acid monomer having a carboxyl group and having a polymerizable double bond. By using the polymer B after acid modification, not only the release of the polymer B from the toner particles is suppressed, but also the release of the wax domain from the toner particles is effectively suppressed. As the acid monomer, one or more monomers selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, and maleic anhydride can be used. The amount of the acid monomer used for the acid modification is preferably 0.01 to 1% by weight with respect to the polymer B subjected to the modification.
[0037]
The amount of the polymer B used is 0.1 to 18 parts by weight, preferably 1 to 15 parts by weight, and more preferably 3 to 10 parts by weight with respect to 100 parts by weight of the binder resin. Two or more kinds of the polymers B may be used in combination, and in that case, the total amount thereof may be within the above range.
[0038]
The binder resin used in the present invention is not particularly limited, and is a binder resin known in the field of electrostatic latent image developing toner, for example, polyester resin, (meth) acrylic resin, styrene- (meth) acrylic resin. Copolymer resin, epoxy resin, COC (cyclic olefin resin (for example, TOPAS-COC (manufactured by Ticona))) and the like. Since the toner of the present invention is applied to a fixing device that does not require oil application during fixing, a polyester resin is particularly preferably used.
[0039]
In the present invention, a polyester resin obtained by polycondensation of a polyhydric alcohol component and a polycarboxylic acid component can be used as the polyester resin.
Among the polyhydric alcohol components, examples of the dihydric alcohol component include polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene (3,3) -2,2- Bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane Bisphenol A alkylene oxide adducts such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol , Polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A, and the like.
Examples of trihydric or higher alcohol components include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol. 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. Is mentioned.
[0040]
Among the polyvalent carboxylic acid components, examples of the divalent carboxylic acid component include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, and succinic acid. , Adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, isooctenyl succinic acid, n-octyl succinic acid , Isooctyl succinic acid, anhydrides or lower alkyl esters of these acids.
[0041]
Examples of the trivalent or higher carboxylic acid component include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2 , 4-Naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4- Examples include cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, emporic trimer acid, anhydrides of these acids, and lower alkyl esters.
[0042]
In the present invention, as a polyester resin, a polyester resin raw material monomer, a vinyl resin raw material monomer, and a mixture of monomers that react with both resin raw material monomers are used to obtain a polyester resin in the same container. A resin obtained by performing a condensation polymerization reaction and a radical polymerization reaction for obtaining a vinyl resin in parallel can also be suitably used. In addition, the monomer which reacts with the raw material monomers of both resins is, in other words, a monomer that can be used for both the condensation polymerization reaction and the radical polymerization reaction. That is, it is a monomer having a carboxy group that can undergo a condensation polymerization reaction and a vinyl group that can undergo a radical polymerization reaction, and examples thereof include fumaric acid, maleic acid, acrylic acid, and methacrylic acid.
[0043]
Examples of the raw material monomer for the polyester resin include the aforementioned polyhydric alcohol component and polyvalent carboxylic acid component.
Examples of the raw material monomer for the vinyl resin include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, p-tert- Styrene or styrene derivatives such as butylstyrene and p-chlorostyrene; Ethylene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; methyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate , Isobutyl methacrylate, t-butyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, neopentyl methacrylate, 3- (methyl) butyl methacrylate, hexyl methacrylate, octyl methacrylate, nonyl methacrylate, methacrylic acid Silyl, alkyl methacrylates such as undecyl methacrylate, dodecyl methacrylate; methyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n acrylate -Acrylic alkyl esters such as pentyl, isopentyl acrylate, neopentyl acrylate, 3- (methyl) butyl acrylate, hexyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate, etc. Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid; acrylonitrile, maleic acid ester, itaconic acid ester, vinyl chloride, vinyl acetate, vinyl benzoate, vinyl methyl ethyl ketone, vinyl Examples thereof include nilhexyl ketone, vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether. Examples of the polymerization initiator for polymerizing the raw material monomer of the vinyl resin include 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1 Azo or diazo polymerization initiators such as' -azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl Examples thereof include peroxide polymerization initiators such as peroxycarbonate and lauroyl peroxide.
[0044]
The binder resin has an acid value of 5 to 50 KOHmg / g, preferably 10 to 40 KOHmg / g. In particular, when a polyester-based resin is used, by using a resin having such an acid value, the dispersibility of carbon black and various colorants can be improved, and a toner having a sufficient charge amount can be obtained.
[0045]
In the present invention, in order to further improve the offset resistance particularly as an oilless fixing toner, two types of polyester resins having different softening points as polyester resins, particularly the first polyester type having a softening point of 80 to 120 ° C. It is preferable to use a resin and a second polyester resin having a softening point of 120 to 160 ° C. More preferably, the softening point of the first polyester resin is 90 to 115 ° C, and the softening point of the second polyester resin is 125 to 150 ° C. Further, from the viewpoint of further improving the heat resistance of the toner, the glass transition point of the first and second polyester resins is desirably 50 to 75 ° C., and preferably 55 to 70 ° C. As described above, when two types of resins are used as the binder resin, the acid value of the mixed resin may be within the above range.
[0046]
As the first polyester-based resin, a polyester resin obtained by polycondensation of the above-described polyhydric alcohol component and polyvalent carboxylic acid component, particularly a bisphenol A alkylene oxide adduct as a main component as a polyhydric alcohol component, A polyester resin obtained using as a main component at least one selected from the group consisting of terephthalic acid and fumaric acid as the carboxylic acid component is preferred. The first polyester resin desirably has an Mn of 1800 to 7300, preferably 2000 to 5000, and Mw / Mn of 1.7 to 4.6, preferably 2 to 4.
[0047]
As the second polyester resin, a polyester resin obtained by polycondensation of at least the above-described trivalent or higher alcohol component and / or a monomer component containing a trivalent or higher carboxylic acid component, particularly bisphenol A as a dihydric alcohol component. Main component is at least one selected from the group consisting of terephthalic acid, fumaric acid and dodecenyl succinic acid as a divalent carboxylic acid component, using trimellitic acid as a trivalent or higher carboxylic acid component, using an alkylene oxide adduct as a main component. The polyester resin obtained as is preferred.
[0048]
In addition, as the second polyester-based resin, a mixture of a raw material monomer for polyester resin, a raw material monomer for vinyl resin, and a bireactive monomer that reacts with the raw material monomers for both resins is used. It is preferable to use a polyester-based resin obtained by performing a polycondensation reaction for obtaining a polymer and a radical polymerization reaction for obtaining a vinyl-based resin in parallel. Such a resin is preferable from the viewpoint of improving the toughness, fixability, and offset resistance of the toner. In this case, the content of the vinyl resin in the second polyester resin is 10 to 30% by weight, preferably 15 to 25% by weight.
[0049]
The second polyester resin desirably has an Mn of 2000 to 8500, preferably 2400 to 6000, and Mw / Mn of 8 to 40, preferably 15 to 40.
The second polyester resin as described above preferably contains a component insoluble in tetrahydrofuran (THF) from the viewpoint of high-temperature offset resistance. From such a viewpoint, it is preferable to use the first and second polyester-based resins so that the content of the THF-insoluble component in the binder resin is 0.5 to 30% by weight, preferably 5 to 20% by weight.
[0050]
From the viewpoint of further improving the offset resistance, the weight ratio of the first polyester resin to the second polyester resin is 65:35 to 30:70, preferably 60 when the obtained toner is used as a full color toner. : 40 to 35:65, and 20:80 to 50:50, preferably 25:75 to 40:60 when used as a monochrome toner.
[0051]
In order to previously add at least one of the first wax and the second wax to the binder resin, when synthesizing the binder resin, at least one of the first wax and the second wax is added to the monomer for synthesizing the binder resin. The binder resin may be synthesized in the added state. In particular, when the first polyester resin (low molecular weight resin) and the second polyester resin (high molecular weight resin) are used in combination as the binder resin, the second polyester resin is the first polyester resin. Therefore, it is preferable to add at least one of the first wax and the second wax in advance when synthesizing the second polyester resin. Specifically, if a polycondensation reaction (and a radical polymerization reaction if desired) is performed in a state where wax is added to the acid monomer and alcohol monomer (and the raw material monomer of the vinyl resin that is optionally used) constituting the polyester resin, good.
[0052]
As the colorant used in the present invention, known pigments and dyes conventionally used as a colorant for electrostatic latent image developing toners can be used. For example, carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, dupont oil red, quinoline yellow, methylene blue chloride, copper phthalocyanine, malachite green oxalate, lamp black, rose bengal, CI pigment red 48: 1 CI Pigment Red 122, CI Pigment Red 57: 1, CI Pigment Red 184, CI Pigment Yellow 97, CI Pigment Yellow 12, CI Pigment Yellow 17, CI Solvent Yellow 162, CI Pigment Yellow 180 CI pigment yellow 185, CI pigment blue 15: 1, CI pigment blue 15: 3, and the like. The content of the colorant is preferably in the range of 2 to 15 parts by weight with respect to 100 parts by weight of the binder resin.
[0053]
The toner of the present invention may contain a wax dispersion aid. By adding the wax dispersion aid, the adhesion of the wax domain to the binder resin can be improved, and the effect of preventing the release (detachment) of the wax domain is improved.
[0054]
The wax dispersion aid is a graft polymer in which a vinyl monomer is grafted on a polyolefin, and specifically, has a vinyl polymer chain composed of a vinyl monomer as a side chain on a polyolefin as a main chain.
[0055]
Such a graft polymer can be synthesized by a known method. For example, a polyolefin is dissolved in a suitable organic solvent in an autoclave reaction vessel, purged with nitrogen, and then polymerized by dropping a mixed solution of a vinyl monomer and a suitable polymerization initiator while heating. Just melt.
[0056]
As the polyolefin, waxes such as paraffin wax, paraffin latex and microcrystalline wax can be preferably used, and in particular, polyethylene wax and polypropylene wax can be preferably used. These may be used alone or in combination of two or more. The content of the polyolefin in the graft polymer is preferably 10 to 60% by weight, more preferably 10 to 40% by weight.
[0057]
Examples of vinyl monomers include styrene monomers such as styrene and alkylstyrene (for example, α-methylstyrene, p-methylstyrene, etc.), methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl. Hydroxyl groups such as alkyl (meth) acrylates having 1 to 18 carbon atoms such as (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, hydroxyl (meth) acrylate, hydroxypropyl (meth) acrylate Amino group-containing (meth) acrylates such as (meth) acrylate, diethylaminoethyl (meth) acrylate, and (meth) acrylic monomers such as (meth) acrylic acid, acrylonitrile, methacrylonitrile mono-, Includes di-alkyl maleate. These may be used alone or in combination of two or more.
[0058]
When the binder resin is a polyester resin, it is more preferable to use acrylonitrile as a vinyl monomer constituting the graft polymer from the viewpoint of improving the adhesion of the wax domain to the polyester resin. In addition, when a binder resin in which a high molecular weight resin and a low molecular weight resin are used in combination is used as the binder resin, since the high molecular weight resin has a lower wax domain adhesion than the low molecular weight resin, a graft polymer is used. It is preferable to add.
The graft polymer is preferably added in an amount of 0.1 to 15 parts by weight with respect to 100 parts by weight of the binder resin.
[0059]
The toner of the present invention may contain additives such as a charge control agent and magnetic powder.
As the charge control agent, a known charge control agent that has been added to control the chargeability in the field of electrostatic latent image developing toner can be used. For example, fluorine-containing surfactants, salicylic acid metal complexes, metal-containing dyes such as azo-based metal compounds, polymer acids such as copolymers containing maleic acid as a monomer component, calixarene compounds, organoboron compounds, etc. Can be used.
[0060]
The toner of the present invention is a production of an oilless fixing toner in which a binder resin, a colorant, a first wax, a second wax, a polymer B, and other desired additives are melt-kneaded and cooled, and then pulverized and classified. In the method, the kneading temperature is the softening point (° C.) of the binder resin (hereinafter sometimes referred to as “Bm”) + 30 ° C. or higher, preferably Bm + 30 ° C. or higher, Bm + 120 ° C. or lower, more preferably Bm + 40 ° C. or higher, Bm + 100 ° C. or lower. Can be obtained. The kneading temperature is 160 to 220 ° C, preferably 170 to 210 ° C. The first wax and / or the second wax may be used to be mixed simultaneously with the toner material such as the binder resin and the colorant as described above, or may be used to be added in advance during the synthesis of the binder resin. . In the case where two or more kinds of resins are mixed and used as the binder resin, the softening point of these mixed resins is defined as “the softening point of the binder resin”.
[0061]
In general, in the toner manufacturing technology, the binder resin in the kneaded product is melt-kneaded in a state where the binder resin has a certain degree of viscosity, whereby a shearing force is applied to the binder resin to draw the molten wax by the molten binder resin. The wax dispersibility is improved by cutting. Therefore, the wax particles are finely dispersed in the binder resin so that the average dispersion diameter is about 0.5 μm or less. The kneading temperature is generally about 20 ° C. higher than the softening point of the binder resin, usually about 140 ° C.
[0062]
In the present invention, the kneading temperature is set relatively high as described above, and the melt kneading is performed under the condition that the binder resin in the kneaded product has a low viscosity so that no shearing force acts on the binder resin during melt kneading. When melt-kneading is performed under such conditions, it becomes possible to add a high amount of wax to the toner particles and to form a domain having a relatively large average dispersed particle diameter in which a plurality of types of waxes are integrated. This is because the kneaded material (melted binder resin) has a low viscosity, so that each molten wax easily flows in the kneaded material, and each molten wax aggregates to form an integrated domain, and shearing is performed. It is presumed that the domain has a relatively large particle size because no force acts.
[0063]
In the present invention, the dispersed particle size of the wax domains in the toner particles can be controlled by changing the kneading temperature and the total amount of added wax. Increasing the kneading temperature or increasing the total addition amount generally increases the dispersed particle size of the wax domains in the toner particles obtained. On the other hand, when the kneading temperature is lowered or the total addition amount is reduced, the dispersed particle diameter of the wax domains in the toner particles is generally reduced.
Further, the dispersed particle diameter of the polymer B in the toner particles can be controlled by changing the amount of the polymer B added. Increasing the amount added generally increases the dispersed particle size of polymer B. On the other hand, when the addition amount is reduced, the dispersed particle size of the polymer B is generally reduced.
The volume average particle diameter of the toner is 4 to 10 μm, preferably 5 to 8 μm.
[0064]
When fixing the toner image composed of the toner of the present invention as described above, the fixing oil is applied or impregnated to either the heating member or the pressure member disposed in pressure contact with the heating member. It is preferable to employ an oilless fixing method including passing a recording sheet (for example, paper) carrying a toner image through a pressure contact portion between the heating member and the pressure member or the pressure heating member. In particular, from the viewpoint of effectively achieving separation of the sheet from the heating member, it is preferable that the nip configuration of the pressure contact portion is convex upward. Furthermore, the heating member has a surface with a fluorine-based resin such as PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), polytetrafluoroethylene, polyfluoride from the viewpoint of further improving the separation between the paper and the heating member. It is preferably formed from vinylidene or the like.
[0065]
As a fixing device employing such a fixing method, for example, a fixing device schematically shown in FIG. 1 can be preferably used. The fixing device shown in FIG. 1 uses a heating roller 11 as a heating member and a pressure roller 12 as a pressure member. Specifically, the heating roller 11, the pressure roller 12 pressed against the heating roller, the separation claw 13 for separating the fixed sheet from the heating roller, the cleaning web 14 for cleaning the surface of the heating roller, and the cleaning web are wound. A rotated web roller 15 and a winding roller 16 for winding the cleaning web are provided. The heating roller 11 usually has an elastic body layer 18 and a surface layer 19 on an aluminum cored bar 17 and a heater 20 inside the aluminum cored bar. The pressure roller 12 usually has an elastic layer 22 and a surface layer 23 on an aluminum cored bar 21. The material of the elastic layer (18, 22) is not particularly limited, but is preferably silicone rubber. The material of the surface layers (19, 23) is not particularly limited, but is preferably a fluororesin, particularly PFA.
In FIG. 1, a nip 24 having a convex shape on the heating roller side (upper side) is formed at the pressure contact portion between the heating roller 11 and the pressure roller 12. Fixing is performed by passing the recording sheet 25 carrying the toner image 26 from the right to the left in the drawing through the pressure contact portion.
[0066]
【Example】
(Production examples of resins 1, 2, 4-8, 11 and 12 (St / Ac compound wax-added polyester resin))
Styrene and butyl acrylate (StAc monomer) as monomers for the vinyl resin and dicumyl peroxide as a polymerization initiator were placed in the dropping funnel in the molar ratio shown in Table 1. Next, as a polyester monomer (PES monomer), an alcohol component and an acid component are added in the molar ratio shown in Table 1, and fumaric acid is added as a bireactive compound among the acid components, and dibutyl peroxide is used as an esterification catalyst. Add the wax shown in Table 1 to the glass four-necked flask equipped with a thermometer, stainless steel stir bar, flow-down condenser, and nitrogen inlet tube at the addition amount shown in Table 1 (% by weight based on the charged monomer). Then, a vinyl resin monomer and a polymerization initiator prepared in advance from a dropping funnel were dropped while heating and stirring in a mantle heater at 160 ° C. in a nitrogen atmosphere. Thereafter, the addition polymerization reaction was aged while maintaining a constant temperature of 160 ° C., and then the temperature was raised to 230 ° C. to perform a condensation polymerization reaction. The progress of this reaction was followed by measuring the acid value or softening point. When a predetermined acid value or softening point was reached, the reaction was terminated and cooled to room temperature to obtain a polyester resin. The weight ratio of PES monomer to StAc monomer in each resin is as shown in Table 1.
BPA-PO: Bisphenol A propylene oxide adduct
BPA-EO: Bisphenol A ethylene oxide adduct
TPA: terephthalic acid
TMA: trimellitic acid
DSA: Dodecenyl succinic acid
St: Styrene
BA: Butyl acrylate
[0067]
(Production examples of resins 3, 9 and 10 (resin-free resin))
Place the alcohol and acid components together with the polymerization initiator (dibutyltin oxide) in the molar ratio shown in Table 1 in a glass four-necked flask equipped with a thermometer, stainless steel stir bar, flow-down condenser, and nitrogen inlet tube. It was. This was reacted in a mantle heater by heating with stirring and heating under a nitrogen stream. The progress of this reaction was followed by measuring the acid value or softening point. When a predetermined acid value or softening point was reached, the reaction was terminated and cooled to room temperature to obtain a polyester resin.
[0068]
Tables 1 and 2 show the monomer ratios and physical properties of the resins 1 to 12 obtained by the above production method. Each polyester resin was coarsely crushed to 1 mm or less and used in the following toner production.
[0069]
[Table 1]

[0070]
[Table 2]

[0071]
(wax)
Table 3 shows the waxes used in this example.
[Table 3]

[0072]
(Production example of polymer B1)
Add 500 g of α-methylstyrene (purity 99.8%) and 500 g of toluene to a three-necked flask, add a small amount of boron trifluoride phenol complex while stirring, and react at 20 ° C for 3 hours while cooling in a dry ice / acetone bath. I let you. Next, alkali was added to deactivate and remove the catalyst, and the mixture was concentrated to drive off the solvent and unreacted monomers to obtain an α-methylstyrene monopolymer. This is designated as Polymer B1.
[0073]
(Production example of polymer B2)
500 g of styrene (purity 99.9%) and 500 g of toluene were placed in a three-necked flask, and a boron trifluoride phenol complex was added little by little with stirring. The mixture was reacted at 20 ° C. for 3 hours while cooling in a dry ice / acetone bath. Subsequently, alkali was added to deactivate and remove the catalyst, and the mixture was concentrated to drive off the solvent and unreacted monomers to obtain a styrene monopolymer. This is designated as Polymer B2.
[0074]
(Production example of polymer B3)
Add 250 g of isopropenyltoluene (purity 98%), 250 g of α-methylstyrene (purity 99.8%), and 500 g of toluene to a three-necked flask. The reaction was allowed to proceed for 3 hours while cooling in a bath. Next, an aqueous NaOH solution was added, and the mixture was vigorously stirred to decompose the catalyst. Then, the aqueous phase was separated to obtain an oily polymer. Further, the oily polymer was washed with water until neutrality, and then the unreacted oil and the solvent were distilled off under reduced pressure under heating to obtain a white block polymer. To this polymer, 0.5 g of maleic anhydride and 0.5 g of di-tert-butyl peroxide were added, heated to 180 to 210 ° C., reacted for 3 hours with stirring, and further at 200 ° C. for 15 to 30 minutes, at 20 mmHg. The polymer B3 was obtained by performing a reduced pressure treatment.
[0075]
(Production example of polymer B4)
200 g of isopropenyltoluene (purity 99.8%), 200 g of α-methylstyrene (purity 99.8%), 120 g of C5 petroleum fraction (isoprene) obtained by pyrolysis of petroleum naphtha, and 500 g of toluene are placed in a three-necked flask. While stirring, boron trifluoride phenol complex was added little by little and reacted for 3 hours while cooling in a dry ice / acetone bath. Next, an aqueous NaOH solution was added, and the mixture was vigorously stirred to decompose the catalyst. Then, the aqueous phase was separated to obtain an oily polymer. Further, the oily polymer was washed with water until neutral, and then the unreacted oil and the solvent were distilled off under reduced pressure by heating to obtain a white block copolymer. To this polymer, 0.5 g of maleic anhydride and 0.5 g of di-tert-butyl peroxide were added, heated to 180 to 210 ° C., reacted for 3 hours with stirring, and further at 200 ° C. for 15 to 30 minutes, at 20 mmHg. The copolymer B4 was obtained by performing a reduced pressure treatment.
[0076]
(Production example of polymer B5)
A polymer B5 was obtained by the same production method as the polymer B2, except that the reaction time was 2 hours.
(Production example of polymer B6)
A polymer B6 was obtained by the same production method as the polymer B1, except that the reaction time was 4.5 hours.
[0077]
Table 4 shows the physical properties of the polymers B1 and B2 obtained by the above production method.
[Table 4]

[0078]
Example 1
In the production of the toner, the resin used was a dry blend of Resin 1 and Resin 3 in a weight ratio of 64.5: 40 using a Henschel mixer. This blended resin and magenta pigment (CI Pigment Red 184) were charged and kneaded into a pressure kneader so that the weight ratio of the resin was 7: 3 (resin component only when the resin contains a wax component). . The obtained kneaded product was cooled and pulverized by a feather mill to obtain a pigment master batch. The resin and the pigment master batch are used so that the weight ratio of resin (only the resin component when the resin contains a wax component): pigment is 100: 4, and the resin (the resin contains the wax component) (When the resin component only) Add 100 parts by weight of WAX2 shown in Table 5 and 4.0 parts by weight of polymer B1 with respect to 100 parts by weight. After mixing with a Henschel mixer, mix the mixture with a twin-screw kneader (TEM50, Toshiba Machine) Kneaded at a kneading temperature of 180 ° C. After cooling the obtained kneaded product, coarsely pulverized with a feather mill, pulverized with a mechanical pulverizer A (kryptron pulverizer, manufactured by Kawasaki Heavy Industries, Ltd.), and further a circulating pulverizer B (jet mill pulverizer, Finely pulverized by Nippon Pneumatic Kogyo Co., Ltd., classified by mechanical classifier C (ATP classifier, manufactured by Alpine Co.), and further classified in the same manner to obtain a toner having a volume average particle size of about 7 μm. The toner particles are 0.9% by weight of hydrophobic silica (manufactured by Hoechst Japan; H2000), 0.9% by weight of hydrophobic titania (manufactured by Titanium Industry Co., Ltd .; STT30A), and 2.5% by weight of strontium titanate. %, And these were mixed by a Henschel mixer and added to obtain a magenta toner.
[0079]
Examples 2 to 26 and Comparative Examples 1 to 9
A toner was obtained in the same manner as in Example 1 except that various materials were used so that the toner composition shown in Table 5 or 6 was obtained, and that the kneading temperature was set to the values shown in Table 5 or 6. It was.
[0080]
[Table 5]

[0081]
[Table 6]

[0082]
The obtained toner was evaluated for the following items, and the results are shown in Tables 7 and 8.
<Wax domain diameter and domain diameter of polymer B>
After slicing the toner particles with a microtome, a TEM (Transmission Electron Microscope) photographed at a magnification of 10,000 times, this photographic image was taken into an image analyzer (Luzex 5000; manufactured by Nippon Regulator Co., Ltd.), and the particle size distribution of each domain diameter Was measured. When the domain was not completely spherical, it was calculated by the equivalent circle diameter of the cross-sectional area of the domain.
[0083]
<Heat resistance>
After 10 g of toner was left at a high temperature of 50 ° C. for 24 hours, the toner was visually confirmed.
○: No aggregation toner, no problem at all;
△: Light soft agglomeration exists, but can be solved easily with a light force and has no practical problem;
X: Strong agglomerates exist, which cannot be easily solved, and have practical problems.
[0084]
<Separability and anti-offset performance>
The test pattern is a solid band image with a width of 36 mm and a tip of 5 mm on A4 vertical paper, assuming the toner adhesion amount when three colors are superimposed (attachment amount 12 g / m ² ) Was printed. The unfixed image was fixed at various fixing temperatures using the following fixing devices 1 and 2, and a separable / non-offset temperature range was determined. The temperature range is a fixing temperature range in which the paper is satisfactorily separated from the heating roller and no offset phenomenon occurs.
[0085]
The fixing device 1 is a device shown in FIG. 1 and is of a soft roller type having a fluorine-based surface layer composition. Specifically, the heating roller 11 has an outer diameter of 40 mm, an aluminum core 17 and a 1.5 mm-thick elastic body layer 18 made of silicone rubber and a PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) surface layer 19. The heater 20 is provided inside the aluminum cored bar. The pressure roller 12 has an outer diameter of 35 mm, and has an elastic body layer 22 made of silicone rubber and a PFA surface layer 23 made of silicone rubber on an aluminum core bar 21. A nip (nip width 7 mm) 24 having a convex shape on the heating roller side is formed at the pressure contact portion between the heating roller 11 and the pressure roller 12.
[0086]
The fixing device 2 is a fixing device of a digital copying machine Di350 (manufactured by Minolta Co., Ltd.), and is a type having a separation claw with a Teflon hard roller system.
Each apparatus was configured with a wave roller for cleaning the fixing roller, but the experiment was conducted without using fixing oil. The paper used and the paper passing direction are 64g / m, which is disadvantageous for separability ² The paper was run through the Y-thru of the paper. The fixing temperature range was 120 to 220 ° C. Fixing device peripheral speed 120mm / sec.
○: Separable / non-offset temperature range was 50 ° C or higher;
Δ: Separable / non-offset temperature range was 30 ° C or higher and lower than 50 ° C;
X: The separable / non-offset temperature range was less than 30 ° C.
[0087]
<10k actual machine running>
The developer is prepared by mixing each evaluation toner and carrier (ferrite carrier coated with silicone-acrylic resin 35μm) so that the toner mixing ratio is 8wt%, creating a starter with mixing time of 30 minutes on the stand, and color copier CF -900 (Minolta Co., Ltd.) ran 10,000 sheets and confirmed practical problems related to filming on the image.
○: No filming occurred;
Δ: Filming occurs slightly, but there is no practical problem;
X: There was a problem in practical use.
[0088]
<Manufacturability>
In producing the toner, the average amount of toner adhering to each apparatus was calculated from the input amount and the recovered amount.
○: Adhesion amount was less than 5% of the input amount;
Δ: The adhesion amount was 5% or more and less than 10% of the input amount;
X: The adhesion amount was 10% or more of the input amount.
[0089]
[Table 7]

[0090]
[Table 8]

[0091]
Other measurement methods used in the present invention are shown below.
<Method of measuring glass transition point (Tg)>
Using a differential scanning calorimeter (DSC-200: manufactured by Seiko Electronics Co., Ltd.), accurately weigh 10 mg of the sample to be measured, place it in an aluminum pan, and heat up using a sample in which alumina is placed in an aluminum pan as a reference. After raising the temperature from room temperature to 200 ° C at a rate of 30 ° C / min, this is cooled and measured between 20-120 ° C at a rate of temperature increase of 10 ° C / min. The shoulder value of the main endothermic peak in the range was defined as Tg.
[0092]
<Wax peak measurement method>
Using a differential scanning calorimeter (DSC-200: manufactured by Seiko Electronics Co., Ltd.), accurately weigh 10 mg of the sample to be measured, place it in an aluminum pan, and heat up using a sample in which alumina is placed in an aluminum pan as a reference. After raising the temperature from room temperature to 200 ° C at a rate of 30 ° C / min, this is cooled and measured between 20 and 185 ° C at a rate of temperature increase of 10 ° C / min. The temperature at the peak of the endothermic curve was taken as the respective WAXDSC peak temperature.
[0093]
<Method of measuring resin / toner softening point (Tm)>
Using a flow tester (CFT-500; manufactured by Shimadzu Corporation), weigh 1.5 g of the sample to be measured, use a h1.0 mm x φ1.0 mm die, heat-up rate 3.0 ° C / min, preheating time 180 seconds, load Measurement was performed under the conditions of 30 kg and a measurement temperature range of 80 to 140 ° C., and the temperature at which the above sample flowed out 1/2 was taken as the softening point.
[0094]
<Mn, Mw measurement method>
It measured using gel permeation chromatography (807-IT type; manufactured by JASCO Corporation). While maintaining the column at 40 ° C, tetrahydrofuran as a carrier solution was 1 kg / cm. ² Then, 30 mg of a sample to be measured was dissolved in 20 ml of tetrahydrofuran, 0.5 mg of this solution was introduced into the apparatus together with the above carrier solvent, and determined by polystyrene conversion.
[0095]
<Method for measuring acid value>
A 10 mg sample is dissolved in 50 ml of toluene and titrated with a pre-standardized N / 10 potassium hydroxide / alcohol solution using a mixed indicator of 0.1% bromothymol blue and phenol red. It is a value calculated from the consumption of the alcohol solution.
[0096]
<Hydroxy acid value>
The hydroxy value was expressed in terms of mg of potassium hydroxide which is necessary for treating a weighed sample with acetic anhydride, hydrolyzing the obtained acetyl compound, and neutralizing free acetic acid.
[0097]
<Measurement method of THF insoluble content>
The THF-insoluble content was measured by Soxhlet extraction for 10 hours using tetrahydrofuran as a solvent.
[0098]
【The invention's effect】
According to the present invention, a toner containing a relatively large amount of wax can be provided. The toner is remarkably improved in toner characteristics by adding a wax, that is, offset resistance and separability, and excellent in heat-resistant storage, filming resistance, and manufacturability.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an example of a fixing device employing a fixing method of the present invention.
[Explanation of symbols]
11: heating roller, 12: pressure roller, 13: separation claw, 14: cleaning web, 15: web roller, 16: winding roller, 17: cored bar, 18: elastic body layer, 19: surface layer, 20: heater , 21: cored bar, 22: elastic layer, 23: surface layer, 24: nip, 25: recording sheet, 26: toner image.

Claims (8)

At least a binder resin, a colorant, a first wax, a second wax of a different type from the first wax, and a polymer B having a weight average molecular weight of 1000 to 3000 and a weight average molecular weight / number average molecular weight of 1.0 to 2.0 An oilless fixing toner that is pulverized after melt-kneading, wherein the domains in which the first wax and the second wax are integrated in the toner particles and the polymer B are dispersed, and the average of the domains The following relationship is established between the dispersed particle diameter d ₁ (μm) and the average dispersed particle diameter d ₂ (μm) of the polymer B;
0.01 <d ₂ <0.5 <d ₁ <3.0
An oil-less fixing toner characterized by satisfying Oilless fixing toner according to claim 1, wherein the average dispersed particle diameter d ₁ of the domains is characterized by a 0.75～2.0Myuemu. Oilless fixing toner according to claim 1 or 2, wherein the average dispersed particle diameter d ₂ of the polymer B is 0.05 to 0.3 m. 4. The oilless fixing toner according to claim 1, wherein a total content of the first wax and the second wax is 3 to 15 parts by weight with respect to 100 parts by weight of the binder resin. . 5. The oilless fixing toner according to claim 1, wherein at least one of the first wax and the second wax is internally added during the synthesis of the binder resin. 6. The oilless fixing toner according to claim 1, wherein the DSC peak temperature of the first wax is 65 to 105 ° C. and the DSC peak temperature of the second wax is 110 to 150 ° C. 6. At least a binder resin, a colorant, a first wax, a second wax of a different type from the first wax, and a polymer B having a weight average molecular weight of 1000 to 3000 and a weight average molecular weight / number average molecular weight of 1.0 to 2.0 A method for producing an oilless fixing toner which is melt kneaded and cooled, and then pulverized and classified, wherein the kneading temperature is set to a softening point of the binder resin + 30 ° C. or higher and a softening point of the binder resin + 120 ° C. or lower. A method for producing an oilless fixing toner. Without applying or impregnating the fixing oil to either the heating member having a fluororesin surface and the pressure member or the pressure heating member disposed in pressure contact with the heating member, the heating member and the pressure member or pressure are applied. 7. An oilless fixing method in which fixing is performed by passing a sheet carrying a toner image through a pressure contact portion with a heating member, wherein the toner image is formed from the oilless fixing toner according to any one of claims 1 to 6. An oil-less fixing method, wherein the nip configuration of the pressure contact portion is convex upward.

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