JP3817432B2 - Toner and image forming method - Google Patents

Description

〔式中、Ｍは配位中心金属を表わし、Ｓｃ、Ｔｉ、Ｖ、Ｃｒ、Ｃｏ、Ｎｉ、Ｍｎ、Ｆｅ等があげられる。Ａｒはアリール基であり、フェニル基、ナフチル基などがあげられ、置換基を有してもよい。この場合の置換基としては、ニトロ基、ハロゲン基、カルボキシル基、アニリド基および炭素数１〜１８のアルキル基、アルコキシ基などがある。Ｘ，Ｘ’、Ｙ，Ｙ’は−Ｏ−、−ＣＯ−、−ＮＨ−、−ＮＲ−（Ｒは炭素数１〜４のアルキル基）である。Ａ⁺は水素、ナトリウム、カリウム、アンモニウム、脂肪族アンモニウムあるいはなしを示す。〕
【０１２９】
特に、中心金属としてはＦｅ又はＣｒが好ましく、置換基としてはハロゲン、アルキル基、アニリド基が好ましく、カウンターイオンとしては水素、アルカリ金属アンモニウム、脂肪族アンモニウムが好ましい。またカウンターイオンの異なる錯塩の混合物も好ましく用いられる。
【０１３０】
あるいは、次の一般式（２）に示した塩基性有機酸金属錯体も負帯電性を与えるものであり、本発明に使用できる。
【０１３１】
【化２】

【０１３２】
特に、中心金属としてはＦｅ，Ｃｒ，Ｓｉ，Ｚｎ，Ａｌが好ましく、置換基としてはアルキル基、アニリド基、アリール基、ハロゲンが好ましく、カウンターイオンは水素、アンモニウム、脂肪族アンモニウムが好ましい。
【０１３３】
そのうちでも、式（１）で表されるアゾ系金属錯体がより好ましく、とりわけ、下記式（３）で表されるアゾ系鉄錯体が最も好ましい。
【０１３４】
【化３】

【０１３５】
次に、該錯体の具体例を示す。
【０１３６】
【化４】

【０１３７】
【化５】

【０１３８】
トナーを正荷電性に制御するものとして下記の物質がある。ニグロシン及び脂肪酸金属塩等による変成物；トリブチルベンジルアンモニウム−１−ヒドロキシ−４−ナフトスルフォン酸塩、テトラブチルアンモニウムテトラフルオロボレートなどの四級アンモニウム塩、及びこれらの類似体であるホスホニウム塩等のオニウム塩及びこれらのレーキ顔料、トリフェニルメタン染料及びこれらのレーキ顔料（レーキ化剤としては、りんタングステン酸、りんモリブデン酸、りんタングステンモリブデン酸、タンニン酸、ラウリン酸、没食子酸、フェリシアン化物、フェロシアン化物など）、高級脂肪酸の金属塩；ジブチルスズオキサイド、ジオクチルスズオキサイド、ジシクロヘキシルスズオキサイドなどのジオルガノスズオキサイド；ジブチルスズボレート、ジオクチルスズボレート、ジシクロヘキシルスズボレートなどのジオルガノスズボレート類；グアニジン化合物、イミダゾール化合物。これらを単独で或いは２種類以上組合せて用いることができる。これらの中でも、トリフェニルメタン化合物、カウンターイオンがハロゲンでない四級アンモニウム塩が好ましく用いられる。また、一般式（４）
【０１３９】
【化６】

〔式中、Ｒ₁はＨ又はＣＨ₃を示し、Ｒ₂及びＲ₃は置換または未置換のアルキル基（好ましくは、Ｃ１〜Ｃ４）を示す〕
で表わされるモノマーの単重合体；前述したスチレン、アクリル酸エステル、メタクリル酸エステルの如き重合性モノマーとの共重合体を正荷電性制御剤として用いることができる。この場合これらの荷電制御剤は、結着樹脂（の全部または一部）としての作用をも有する。
【０１４０】
特に下記一般式（５）で表わされる化合物が本発明の構成においては好ましい。
【０１４１】
【化７】

［式中、Ｒ₁、Ｒ₂、Ｒ₃、Ｒ₄、Ｒ₅及びＲ₆は、各々互いに同一でも異なっていてもよい水素原子、置換もしくは未置換のアルキル基または、置換もしくは未置換のアリール基を表し、Ｒ₇、Ｒ₈及びＲ₉は、各々互いに同一でも異なっていてもよい水素原子、ハロゲン原子、アルキル基、アルコキシ基を表し、Ａ^-は、硫酸イオン、硝酸イオン、ほう酸イオン、りん酸イオン、水酸イオン、有機硫酸イオン、有機スルホン酸イオン、有機りん酸イオン、カルボン酸イオン、有機ほう酸イオン又はテトラフルオロボレートから選択される陰イオンを示す。］
【０１４２】
電荷制御剤をトナーに含有させる方法としては、トナー内部に添加する方法と外添する方法がある。これらの電荷制御剤の使用量としては、結着樹脂の種類、他の添加剤の有無、分散方法を含めたトナー製造方法によって決定されるもので、一義的に限定されるものではないが、好ましくは結着樹脂１００質量部に対して０．１〜１０質量部、より好ましくは０．１〜５質量部の範囲で用いられる。
【０１４３】
本発明のトナーにおいては、帯電安定性、現像性、流動性、耐久性向上の為、シリカ微粉末を添加することが好ましい。
【０１４４】
本発明に用いられるシリカ微粉末は、ＢＥＴ法で測定した窒素吸着による比表面積が２０ｍ²／ｇ以上（特に３０〜４００ｍ²／ｇ）の範囲内のものが良好な結果を与える。トナー１００質量部に対してシリカ微粉体０．０１〜８質量部、好ましくは０．１〜５質量部使用するのが良い。
【０１４５】
また、該シリカ微粉末は、必要に応じ、疎水化、帯電性コントロールなどの目的でシリコーンワニス、各種変性シリコーンワニス、シリコーンオイル、各種変性シリコーンオイル、シランカップリング剤、シリル化剤、その他の有機ケイ素化合物等の処理剤で、あるいは種々の処理剤で併用して処理されていることも好ましい。
【０１４６】
また、現像性や耐久性を向上させるために次の無機粉体を添加することも好ましい。マグネシウム、亜鉛、アルミニウム、セリウム、コバルト、鉄、ジルコニウム、クロム、マンガン、ストロンチウム、錫、アンチモンなどの金属酸化物、チタン酸カルシウム、チタン酸マグネシウム、チタン酸ストロンチウムなどの複合金属酸化物；炭酸カルシウム、炭酸マグネシウム、炭酸アルミニウム等の金属塩；カオリンなどの粘土鉱物；アパタイトなどリン酸化合物；炭化ケイ素、窒化ケイ素などのケイ素化合物；カーボンブラックやグラファイトなどの炭素粉末が挙げられる。なかでも、酸化亜鉛、酸化アルミニウム、酸化コバルト、二酸化マンガン、チタン酸ストロンチウム、チタン酸マグネシウムなどが好ましい。
【０１４７】
更に次のような滑剤粉末を添加することもできる。テフロン、ポリフッ化ビニルリデンなどのフッ素樹脂；フッ化カーボンなどのフッ素化合物；ステアリン酸亜鉛等の脂肪酸金属塩；脂肪酸、脂肪酸エステル等の脂肪酸誘導体；硫化モリブデン、アミノ酸およびアミノ酸誘導体が挙げられる。
【０１４８】
トナー製造装置としては、例えば混合機としては、ヘンシェルミキサー（三井鉱山社製）；スーパーミキサー（カワタ社製）；リボコーン（大川原製作所社製）；ナウターミキサー、タービュライザー、サイクロミックス（ホソカワミクロン社製）；スパイラルピンミキサー（太平洋機工社製）；レーディゲミキサー（マツボー社製）が挙げられ、混練機としては、ＫＲＣニーダー（栗本鉄工所社製）；ブス・コ・ニーダー（Ｂｕｓｓ社製）；ＴＥＭ型押し出し機（東芝機械社製）；ＴＥＸ二軸混練機（日本製鋼所社製）；ＰＣＭ混練機（池貝鉄工所社製）；三本ロールミル、ミキシングロールミル、ニーダー（井上製作所社製）；ニーデックス（三井鉱山社製）；ＭＳ式加圧ニーダー、ニダールーダー（森山製作所社製）；バンバリーミキサー（神戸製鋼所社製）が挙げられ、粉砕機としては、カウンタージェットミル、ミクロンジェット、イノマイザ（ホソカワミクロン社製）；ＩＤＳ型ミル、ＰＪＭジェット粉砕機（日本ニューマチック工業社製）；クロスジェットミル（栗本鉄工所社製）；ウルマックス（日曹エンジニアリング社製）；ＳＫジェット・オー・ミル（セイシン企業社製）；クリプトロン（川崎重工業社製）；ターボミル（ターボ工業社製）が挙げられ、分級機としては、クラッシール、マイクロンクラッシファイアー、スペディッククラシファイアー（セイシン企業社製）；ターボクラッシファイアー（日新エンジニアリング社製）；ミクロンセパレータ、ターボプレックス（ＡＴＰ）、ＴＳＰセパレータ（ホソカワミクロン社製）；エルボージェット（日鉄鉱業社製）、ディスパージョンセパレータ（日本ニューマチック工業社製）；ＹＭマイクロカット（安川商事社製）が挙げられ、粗粒などをふるい分けるために用いられる篩い装置としては、ウルトラソニック（晃栄産業社製）；レゾナシーブ、ジャイロシフター（徳寿工作所社）；バイブラソニックシステム（ダルトン社製）；ソニクリーン（新東工業社製）；ターボスクリーナー（ターボ工業社製）；ミクロシフター（槙野産業社製）；円形振動篩い等が挙げられる。
【０１４９】
本発明では、生産工程を増やさずにトナーの円形度をコントロールすることが好ましく、特に粉砕工程でトナーの円形度をコントロールすることが好ましい。
【０１５０】
結着樹脂を主とするトナー粗砕物の粉砕には、図７に示す如きジェット気流を用いたジェット気流式粉砕機、特に衝突式気流粉砕機を用いることができる。
【０１５１】
ジェット気流の如き高圧気体を用いた衝突式気流粉砕機は、ジェット気流で粉体原料を搬送し、加速管の出口より噴射し、粉体原料を加速管の出口の開口面に対向して設けた衝突部材の衝突面に衝突させ、その衝撃力により粉体原料を粉砕する。
【０１５２】
しかしながら、上記の衝突式気流粉砕機は、粉体原料を高圧気体とともに噴出して衝突部材の衝突面に衝突させ、その衝撃によって粉砕するという構成のため、粉砕されたトナーは、不定形で角張ったものとなりやすい。そのため、衝突式気流粉砕機を用いて粉砕し、同時にトナーの円形度をコントロールするためには、粉体原料を衝突部材に衝突させる際の衝撃力を小さくし、粉砕機内に滞留する時間を長くするなどして、粉砕物の凸部を丸める必要が生じる。これは粉砕処理量が低下するため、トナー生産性という点から好ましい方法ではない。
【０１５３】
以下、本発明の好ましいトナーの製造方法の実施の形態を、添付図面を参照しながら具体的に説明する。
【０１５４】
図１は、本発明のトナーの好ましい製造方法の概要を示すフローチャートの一例である。本発明の製造方法は、フローチャートに示されている様に、粉砕処理前の分級工程を必要とせず、粉砕工程及び分級工程が１パスで行われることを特徴としている。
【０１５５】
本発明のトナーの製造方法においては、結着樹脂や着色剤、ワックスなどを含有する混合物を溶融混練し、得られた混練物を冷却した後、冷却物を粉砕手段によって粉砕して得られた粗粉砕物が粉体原料として使用される。
【０１５６】
そして、先ず、所定量の粉砕原料を少なくとも中心回転軸に取り付けられた回転体からなる回転子と、該回転子表面と一定間隔を保持して回転子の周囲に配置されている固定子とを有し、且つ該間隔を保持することによって形成される環状空間が気密状態となるように構成されている機械式粉砕機に導入し、該機械式粉砕機の上記回転子を高速回転させることによって被粉砕物を微粉砕する。次に、微粉砕された粉砕原料は分級工程に導入され分級されて、好ましい粒度を有する粒子群からなるトナー原料となる分級品が得られる。この際、分級工程では、少なくとも粗粉領域、中粉領域及び微粉領域を有する多分割気流式分級機が好ましく用いられる。例えば、３分割気流式分級機を使用した場合には、粉体原料は、少なくとも微粉体、中粉体及び粗粉体の３種類に分級される。このような分級機を用いる分級工程で、好ましい粒度よりも粒径の大きな粒子群からなる粗粉体及び好ましい粒度未満の粒子群からなる微粉体は除かれ、中粉体がトナー製品としてそのまま使用されるか、又は、疎水性コロイダルシリカの如き外添剤と混合された後、トナーとして使用される。
【０１５７】
上記の分級工程で分級された好ましい粒度未満の粒子群からなる微粉体は、一般的には、粉砕工程に導入されてくるトナー材料からなる粉体原料を生成する為の溶融混練工程に供給されて再利用されるか、或いは廃棄される。また、上記微粉体より更に粒子径が小さい、粉砕工程及び分級工程で僅かに発生する超微粉体も同様に、溶融混練工程に供給されて再利用されるか、或いは廃棄される。
【０１５８】
図２に本発明のトナーの製造方法を適用した装置システムの一例を示し、これに基づいて本発明を更に具体的に説明する。この装置システムに導入されるトナー原料である粉体原料には結着樹脂や着色剤、ワックスなどを含有する着色樹脂粒子粉体が用いられるが、該粉体原料は、例えば、結着樹脂や着色剤、ワックスなどからなる混合物を溶融混練し、得られた混練物を冷却し、更に冷却物を粉砕手段によって粗粉砕したものが用いられる。
【０１５９】
この装置システムにおいて、トナー粉原料となる粉砕原料は、先ず、粉砕手段である機械式粉砕機３０１に第１定量供給機３１５を介して所定量導入される。導入された粉砕原料は、機械式粉砕機３０１で瞬間的に粉砕され、補集サイクロン２２９を介して第２定量供給機２に導入される。次いで振動フィーダー３を介し、更に原料供給ノズル１６を介して分級手段である多分割気流式分級機１内に供給される。
【０１６０】
また、この装置システムにおいて、第１定量供給機３１５から粉砕手段である機械式粉砕機３０１に導入される所定量と、第２定量供給機２から分級手段である多分割気流式分級機１に導入される所定量との関係を、第１定量供給機３１５から機械式粉砕機３０１に導入される所定量を１とした場合、第２定量供給機２から多分割気流式分級機１に導入される所定量を好ましくは０．７〜１．７、より好ましくは０．７〜１．５、更に好ましくは１．０〜１．２とすることがトナー生産性及び生産効率という点から好ましい。
【０１６１】
通常、本発明の気流式分級機は、相互の機器をパイプの如き連通手段で連結し、装置システムに組み込まれて使用される。そうした装置システムの好ましい例を図２は示している。図２に示す一体装置システムは、多分割分級装置１（図６に示される分級装置）、定量供給機２、振動フィーダー３、補集サイクロン４、補集サイクロン５、補集サイクロン６を連通手段で連結してなるものである。
【０１６２】
この装置システムにおいて、粉体は、適宜の手段により、定量供給機２に送り込まれ、次いで振動フィーダー３を介し、原料供給ノズル１６により３分割分級装置１内に導入される。導入に際しては、１０〜３５０ｍ／ｓの流速で３分割分級機１内に粉体を導入する。３分割分級機１の分級室を構成する大きさは通常［１０〜５０ｃｍ］×［１０〜５０ｃｍ］なので、粉体は０．１〜０．０１秒以下の瞬時に３種類以上の粒子群に分級し得る。そして、３分割分級機１により、大きい粒子（粗粒子）、中間の粒子、小さい粒子に分級される。その後、大きい粒子は排出導管１１ａを通って、補集サイクロン６に送られ機械式粉砕機３０１に戻される。中間の粒子は排出導管１２ａを介して系外に排出され補集サイクロン５で補集されトナーとなるべく回収される。小さい粒子は排出導管１３ａを介して系外に排出され補集サイクロン４で補集され、トナー材料からなる粉体原料を生成する為の溶融混練工程に供給されて再利用されるか、或いは廃棄される。補集サイクロン４、５、６は粉体を原料供給ノズル１６を介して分級室に吸引導入する為の吸引減圧手段としての働きをすることも可能である。また、この際分級される大きい粒子は、第１定量供給機３１５に再導入し、粉体原料中に混入させて、機械式粉砕機３０１にて再度粉砕することが好ましい。
【０１６３】
また、多分割気流式分級機１から機械式粉砕機３０１に再導入される大きい粒子（粗粒子）の再導入量は、第２定量供給機２から供給される微粉砕品の質量を基準として、０乃至１０．０質量％、更には０乃至５．０質量％とすることがトナー生産上好ましい。多分割気流式分級機１から機械式粉砕機３０１に再導入される大きい粒子（粗粒子）の再導入量が１０．０質量％を超えると、機械式粉砕機３０１内の粉塵濃度が増大し、装置自体の負荷が大きくなるのと同時に、粉砕時に過粉砕され熱によるトナーの表面変質や機内融着を起こしやすいのでトナー生産性という点から好ましくない。
【０１６４】
この装置システムにおいて、粉体原料の粒度は、１８メッシュパス（ＡＳＴＭＥ−１１−６１）が９５質量％以上であり、１００メッシュオン（ＡＳＴＭＥ−１１−６１）が９０質量％以上であることが好ましい。
【０１６５】
また、この装置システムにおいて、重量平均粒径が１０μｍ以下（更には８μｍ以下）のシャープな粒度分布を有するトナーを得る為には、機械式粉砕機で微粉砕された微粉砕物の重量平均粒径が４乃至１０μｍ、４．０μｍ以下が７０個数％以下、更には６５個数％以下、１０．１μｍ以上が２５体積％以下、更には２０体積％以下であることが好ましい。また、分級された中粉体の粒度は、重量平均粒径が５乃至１０μｍ、４．０μｍ以下が４０個数％以下、更には３５個数％以下、１０．１μｍ以上が２５体積％以下、更には２０体積％以下であることが好ましい。
【０１６６】
本発明のトナーの製造方法を適用した上記装置システムにおいては、粉砕処理前の第１分級工程を必要とせず、粉砕工程及び分級工程を１パスで行うことができる。
【０１６７】
本発明のトナーの製造方法に使用される粉砕手段として好ましく用いられる機械式粉砕機について説明する。機械式粉砕機としては、例えば、川崎重工業（株）製粉砕機ＫＴＭ、クリプトロン、ターボ工業（株）製ターボミル等を挙げることができ、これらの装置をそのまま、或いは適宜改良して使用することが好ましい。
【０１６８】
本発明においては、これらの中でも図３、図４及び図５に示したような機械式粉砕機を用いることが、粉体原料の粉砕処理を容易に行うことができるので効率向上が図られ、好ましい。
【０１６９】
以下、図３、図４及び図５に示した機械式粉砕機について説明する。図３は、本発明において使用される機械式粉砕機の一例の概略断面図を示しており、図４は図３におけるＤ−Ｄ’面での概略的断面図を示しており、図５は図３に示す回転子３１４の斜視図を示している。該装置は、図３に示されているように、ケーシング３１３、ジャケット３１６、ディストリビュータ２２０、ケーシング３１３内にあって中心回転軸３１２に取り付けられた回転体からなる高速回転する表面に多数の溝が設けられている回転子３１４、回転子３１４の外周に一定間隔を保持して配置されている表面に多数の溝が設けられている固定子３１０、更に、被処理原料を導入する為の原料投入口３１１、処理後の粉体を排出する為の原料排出口３０２とから構成されている。
【０１７０】
以上のように構成してなる機械式粉砕機での粉砕操作は、例えば次の様にして行う。即ち、図３に示した機械式粉砕機の粉体入口３１１から、所定量の粉体原料が投入されると、粒子は、粉砕処理室内に導入され、該粉砕処理室内で高速回転する表面に多数の溝が設けられている回転子３１４と、表面に多数の溝が設けられている固定子３１０との間に発生する衝撃と、この背後に生じる多数の超高速渦流、並びにこれによって発生する高周波の圧力振動によって瞬時に粉砕される。その後、原料排出口３０２を通り、排出される。トナー粒子を搬送しているエアー（空気）は粉砕処理室を経由し、原料排出口３０２、パイプ２１９、補集サイクロン２２９、バグフィルター２２２、及び吸引フィルター２２４を通って装置システムの系外に排出される。本発明においては、粉体原料の粉砕が行われる為、微粉及び粗粉を増やすことなく所望の粉砕処理を容易に行うことができる。
【０１７１】
また、粉砕原料を機械式粉砕機で粉砕する際に、冷風発生手段３２１により、粉体原料と共に、機械式粉砕機内に冷風を送風し、機械式粉砕機本体をジャケット構造３１６を有する構造とし、冷却水（好ましくはエチレングリコール等の不凍液）を通水することにより、粉砕機内の雰囲気温度を０℃以下、より好ましくは−５〜−１５℃、更に好ましくは−７〜−１２℃とすることがトナー生産性という点から好ましい。粉砕機内の渦巻室の室温を０℃以下、より好ましくは−５〜−１５℃、更に好ましくは−７〜−１２℃とすることにより、熱によるトナーの表面変質を抑えることができ、効率良く粉砕原料を粉砕することができる。粉砕機内の雰囲気温度が０℃を超える場合、粉砕時に熱によるトナーの表面変質や機内融着を起こしやすいのでトナー生産性という点から好ましくない。また、粉砕機内の雰囲気温度を−１５℃より低い温度で運転しようとすると、上記冷風発生手段３２１で使用している冷媒（代替フロン）をフロンに変更しなければならない。
【０１７２】
現在、オゾン層保護の観点からフロンの撤廃が進められている。上記冷風発生手段３２１の冷媒にフロンを使用することは地球全体の環境問題という点から好ましくない。
【０１７３】
なお、冷却水（好ましくはエチレングリコール等の不凍液）は、冷却水供給口３１７よりジャケット内部に供給され、冷却水排出口３１８より排出される。
【０１７４】
また、粉砕原料を機械式粉砕機で粉砕する際に、機械式粉砕機の渦巻室２１２の室温Ｔ１と後室３２１の室温Ｔ２の温度差ΔＴ（Ｔ２−Ｔ１）を３０〜８０℃とすることが好ましく、より好ましくは３５〜７５℃、更に好ましくは３７〜７２℃とすることにより、熱によるトナーの表面変質を抑えることができ、効率良く粉砕原料を粉砕することができる。機械式粉砕機の温度Ｔ１（入口温度）と温度Ｔ２（出口温度）とのΔＴが３０℃より小さい場合、粉砕されずにショートパスを起こしている可能性があり、トナー性能という点から好ましくない。また、８０℃より大きい場合、粉砕時に過粉砕されている可能性があり、熱によるトナーの表面変質や機内融着を起こしやすいのでトナー生産性という点から好ましくない。
【０１７５】
また、粉砕原料を機械式粉砕機で粉砕する際に機械式粉砕機の入口温度は、０℃以下であり、且つ、結着樹脂のガラス転移点（Ｔｇ）に対して６０乃至７５℃低くすることがトナー生産性という点から好ましい。機械式粉砕機の入口温度を０℃以下であり且つＴｇよりも６０乃至７５℃低くすることにより、熱によるトナーの表面変質を抑えることができ、効率良く粉砕原料を粉砕することができる。また、出口温度は、Ｔｇよりも５乃至３０℃、更には１０乃至２０℃低いことが好ましい。機械式粉砕機の出口温度をＴｇよりも５乃至３０℃低くすることにより、熱によるトナーの表面変質を抑えることができ、効率良く粉砕原料を粉砕することができる。
【０１７６】
また、回転する回転子３１４の先端周速としては、８０〜１８０ｍ／ｓであることが好ましく、より好ましくは９０〜１７０ｍ／ｓ、更に好ましくは１００〜１６０ｍ／ｓとすることがトナー生産性という点から好ましい。回転する回転子３１４の周速を８０〜１８０ｍ／ｓであることが好ましく、より好ましくは９０〜１７０ｍ／ｓ、更に好ましくは１００〜１６０ｍ／ｓとすることで、トナーの粉砕不足や過粉砕を抑えることができ、効率良く粉砕原料を粉砕することができる。回転子の周速が８０ｍ／ｓより遅い場合、粉砕されずにショートパスを起こしやすいのでトナー性能という点から好ましくない。また、回転子３１４の周速が１８０ｍ／ｓより速い場合、装置自体の負荷が大きくなるのと同時に、粉砕時に過粉砕されて熱によるトナーの表面変質や機内融着を起こしやすいのでトナー生産性という点から好ましくない。
【０１７７】
また、回転子３１４と固定子３１０との間の最小間隔は０．５〜１０．０ｍｍであることが好ましく、より好ましくは１．０〜５．０ｍｍ、更に好ましくは１．０〜３．０ｍｍとすることが好ましい。回転子３１４と固定子３１０との間の間隔を０．５〜１０．０ｍｍであることが好ましく、より好ましくは１．０〜５．０ｍｍ、更に好ましくは１．０〜３．０ｍｍとすることで、トナーの粉砕不足や過粉砕を抑えることができ、効率良く粉砕原料を粉砕することができる。回転子３１４と固定子３１０との間の間隔が１０．０ｍｍより大きい場合、粉砕されずにショートパスを起こしやすいのでトナー性能という点から好ましくない。また回転子３１４と固定子３１０との間の間隔が０．５ｍｍより小さい場合、装置自体の負荷が大きくなるのと同時に、粉砕時に過粉砕され熱によるトナーの表面変質や機内融着を起こしやすいのでトナー生産性という点から好ましくない。
【０１７８】
本発明の粉砕方法は、粉砕工程前の第１分級工程を必要としないため、トナーが微粒子化されることにより粒子間の静電凝集が高まり、本来は第２分級手段に送られるトナーが再度第１分級手段に循環されることにより過粉砕となった微粉及び超微粉が発生しない。更に、シンプルな構成に加え、粉砕原料を粉砕するのに多量のエアーを必要としないため、電力消費が低く、エネルギーコストを低く抑えることができる。
【０１７９】
次に、本発明のトナー製造方法を構成している分級手段として好ましく用いられる気流式分級機について説明する。
【０１８０】
本発明に使用される好ましい多分割気流式分級機の一例として、図６（断面図）に示す形式の装置を一具体例として例示する。
【０１８１】
図６において、側壁２２及びＧブロック２３は分級室の一部を形成し、分級エッジブロック２４及び２５は分級エッジ１７及び１８を具備している。Ｇブロック２３は左右に設置位置をスライドさせることが可能である。また、分級エッジ１７及び１８は、軸１７ａ及び１８ａを中心にして、回動可能であり、分級エッジを回動して分級エッジ先端位置を変えることができる。各分級エッジブロック２４及び２５は左右に設置位置をスライドさせることが可能であり、それに伴ってそれぞれのナイフエッジ型の分級エッジ１７及び１８も左右にスライドする。この分級エッジ１７及び１８により、分級室３２の分級域３０は３分割されている。
【０１８２】
原料粉体を導入する為の原料供給口４０を原料供給ノズル１６の最後端部に有し、該原料供給ノズル１６の後端部に高圧エアーノズル４１と原料粉体導入ノズル４２とを有し、且つ分級室３２に開口部を有する原料供給ノズル１６を側壁２２の右側に設け、該原料供給ノズル１６の下部接線の延長方向に対して長楕円弧を描く様にコアンダブロック２６が設置されている。分級室３２の左部ブロック２７は、分級室３２の右側方向にナイフエッジ型の入気エッジ１９を具備し、更に分級室３２の左側には分級室３２に開口する入気管１４及び１５を設けてある。また、図２に示すように、入気管１４及び１５には、ダンパーの如き第１気体導入調節手段２０及び第２気体導入調節手段２１と静圧計２８及び２９を設けてある。
【０１８３】
分級エッジ１７、１８、Ｇブロック２３及び入気エッジ１９の位置は、被分級処理原料であるトナーの種類及び所望の粒径により調整される。
【０１８４】
また、分級室３２の上面にはそれぞれの分画域に対応させて、分級室内に開口する排出口１１、１２及び１３を有し、排出口１１、１２及び１３にはパイプの如き連通手段が接続されており、それぞれにバルブ手段の如き開閉手段を設けて良い。
【０１８５】
原料供給ノズル１６は直角筒部と角錘筒部とからなり、直角筒部の内径と角錘筒部の最も狭い個所の内径の比を２０：１から１：１、好ましくは１０：１から２：１に設定すると、良好な導入速度が得られる。
【０１８６】
以上の様に構成してなる多分割分級域での分級操作は、例えば次の様にして行う。即ち、排出口１１、１２及び１３の少なくとも一つを介して分級室内を減圧し、分級室内に開口部を有する原料供給ノズル１６中を該減圧によって流動する気流と高圧エアー供給ノズル４１から噴射される圧縮エアーのエゼクター効果により、好ましくは流速１０〜３５０ｍ／ｓの速度で粉体を原料供給ノズル１６を介して分級室に噴射し、分散する。
【０１８７】
分級室に導入された粉体中の粒子は、コアンダブロック２６のコアンダ効果による作用と、その際流入する空気の如き気体の作用とにより湾曲面を描いて移動し、それぞれの粒子の粒径及び慣性力の大小に応じて、大きい粒子（粗粒子）は気流の外側、すなわち分級エッジ１８の外側の第１分画、中間の粒子は分級エッジ１８と１７の間の第２分画、小さい粒子は分級エッジ１７の内側の第３分画に分級され、分級された大きい粒子は排出口１１より排出され、分級された中間の粒子は排出口１２より排出され、分級された小さい粒子は排出口１３よりそれぞれ排出される。
【０１８８】
上記の粉体の分級において、分級点は、粉体が分級室３２内へ飛び出す位置であるコアンダブロック２６の下端部分に対する分級エッジ１７及び１８のエッジ先端位置によって主に決定される。更に、分級点は、分級気流の吸引流量或いは原料供給ノズル１６からの粉体の噴出速度等の影響を受ける。
【０１８９】
また、本発明のトナーの製造方法及び製造システムにおいては、粉砕及び分級条件をコントロールすることにより、重量平均径が１０μｍ以下（特に、８μｍ以下）である粒径のシャープな粒度分布を有するトナーを効率良く生成することができる。
【０１９０】
本発明のトナーを作製するには、結着樹脂及びワックス成分を少なくとも含有する混合物が材料として用いられるが、その他、必要に応じて着色剤としての顔料または染料、磁性粉、荷電制御剤、及びその他の添加剤等が用いられる。これらの材料をヘンシェルミキサー又はボールミルの如き混合機により十分混合してから、ロール、ニーダー及びエクストルーダーの如き熱混練機を用いて溶融、捏和及び混練して樹脂類を互いに相溶せしめた中に、顔料又は染料を分散又は溶解せしめ、冷却固化後、粉砕及び分級を行ってトナーを得ることができるが、本発明においては、この粉砕工程及び分級工程に、上記で説明した構成の装置システムを用いることが好ましい。
【０１９１】
トナー製造装置としては、例えば混合機としては、ヘンシェルミキサー（三井鉱山社製）；スーパーミキサー（カワタ社製）；リボコーン（大川原製作所社製）；ナウターミキサー、タービュライザー、サイクロミックス（ホソカワミクロン社製）；スパイラルピンミキサー（太平洋機工社製）；レーディゲミキサー（マツボー社製）が挙げられ、混練機としては、ＫＲＣニーダー（栗本鉄工所社製）；ブス・コ・ニーダー（Ｂｕｓｓ社製）；ＴＥＭ型押し出し機（東芝機械社製）；ＴＥＸ二軸混練機（日本製鋼所社製）；ＰＣＭ混練機（池貝鉄工所社製）；三本ロールミル、ミキシングロールミル、ニーダー（井上製作所社製）；ニーデックス（三井鉱山社製）；ＭＳ式加圧ニーダー、ニダールーダー（森山製作所社製）；バンバリーミキサー（神戸製鋼所社製）が挙げられ、粉砕機としては、カウンタージェットミル、ミクロンジェット、イノマイザ（ホソカワミクロン社製）；ＩＤＳ型ミル、ＰＪＭジェット粉砕機（日本ニューマチック工業社製）；クロスジェットミル（栗本鉄工所社製）；ウルマックス（日曹エンジニアリング社製）；ＳＫジェット・オー・ミル（セイシン企業社製）；クリプトロン（川崎重工業社製）；ターボミル（ターボ工業社製）が挙げられ、分級機としては、クラッシール、マイクロンクラッシファイアー、スペディッククラシファイアー（セイシン企業社製）；ターボクラッシファイアー（日新エンジニアリング社製）；ミクロンセパレータ、ターボプレックス（ＡＴＰ）、ＴＳＰセパレータ（ホソカワミクロン社製）；エルボージェット（日鉄鉱業社製）、ディスパージョンセパレータ（日本ニューマチック工業社製）；ＹＭマイクロカット（安川商事社製）が挙げられ、粗粒などをふるい分けるために用いられる篩い装置としては、ウルトラソニック（晃栄産業社製）；レゾナシーブ、ジャイロシフター（徳寿工作所社）；バイブラソニックシステム（ダルトン社製）；ソニクリーン（新東工業社製）；ターボスクリーナー（ターボ工業社製）；ミクロシフター（槙野産業社製）；円形振動篩い等が挙げられる。
【０１９２】
本発明で用いられる定着装置としては、省エネルギー化（低消費電力化）と、ユーザーの操作性向上（クイックプリント）を両立させる装置として、特開昭５９−３３７８７号公報に示されるように、加熱源として高周波誘導を利用した誘導加熱方式の定着装置が使用される。
【０１９３】
この誘導加熱定着装置は、金属導体からなる中空の定着ローラーの内部にコイルが同心状に配置されており、このコイルに高周波電流を流して生じた高周波磁界により定着ローラーに誘導渦電流を発生させ、定着ローラー自体の表比抵抗によって定着ローラーそのものをジュール発熱させるようになっている。
【０１９４】
誘導加熱方式の定着装置によれば、電気−熱変換効率が極めて向上するため、ウエイト時間の短縮化が可能となる。
【０１９５】
また、コイルに磁性体からなるコア（磁界遮断部材）を組み合わすことで、高周波磁界の発生を効率的に行なうことができる。
【０１９６】
特に断面形状がＴ型のコアを用いた場合、高周波磁束の効果的な集中や、発熱部位以外への磁界の遮蔽効果により、定着装置として必要な熱量を低電力で発生させることが出来る。
【０１９７】
以下に図面を参照して、本発明に用いられる好適な定着装置の実施の形態を例示的に詳しく説明する。ただし、この実施の形態に記載されている構成部品の寸法、材質、形状その相対配置などは、特に特定的な記載が無い限りは、この発明の範囲をそれらのみに限定する趣旨のものではない。
【０１９８】
本発明の実施の形態に係る加熱装置は、複写機やプリンター等の画像形成装置に適用されるものであるが、画像形成装置については公知技術であるのでその詳細な説明は省略する。
【０１９９】
以下の実施の形態においては、電子写真式の画像形成装置に備えられる、いわゆる定着装置として加熱装置を適用した場合について説明する。
【０２００】
この場合の構成を簡単に説明すると、公知の電子写真プロセスによって、シート上に未定着のトナー画像を形成し、その後、このシートに加熱且つ加圧してトナー画像を定着させるために、定着装置が備えられるものである。図８〜１０を参照して、本発明の実施の形態に係わる加熱装置（定着装置）について説明する。
【０２０１】
図８〜１０は本発明の実施の形態に係わる定着装置の概略構成断面図である。
【０２０２】
定着ローラー５０１は、例えば、外径４０〔ｍｍ〕、厚さ０．７〔ｍｍ〕の鉄製の芯金シリンダに、表面の離型性を高めるために例えばＰＴＦＥ１０〜５０〔μｍ〕や、ＰＦＡ１０〜５０〔μｍ〕の層を設けることで構成される。
【０２０３】
加圧ローラー５０２は、中空芯金５１４と、その外周面に形成される表面離型性耐熱ゴム層である弾性層５１５とからなる。
【０２０４】
この加圧ローラー５０２の両端には軸受部が形成され、図示しない定着ユニットフレームに回転自在に取り付けられている。
【０２０５】
定着ローラー５０１と加圧ローラー５０２は回転自在に支持されていて、定着ローラー５０１のみを駆動する構成になっている。
【０２０６】
加圧ローラー５０２は定着ローラー５０１の表面に圧接していて、圧接部（ニップ部）での摩擦力で従動回転するように配置してある。
【０２０７】
また、加圧ローラー５０２は定着ローラー５０１の回転軸方向に、例えばバネなどを用いた図示しない機構によって加圧されている。
【０２０８】
加圧ローラー５０２は、例えば約２９４〔Ｎ〕で荷重されて、その場合の圧接部の幅（ニップ部）は約〔６ｍｍ〕に構成される。もちろん使用条件等を考慮して荷重を変化させてニップ幅を変えてもよい。
【０２０９】
温度センサー５０６は定着ローラー５０１の表面に当接するように配置され、温度センサー５０６の検出信号をもとに励磁手段としての励磁コイル５０３への電力供給を増減させることで、定着ローラー５０１の表面温度が所定の一定温度になるように自動制御される。
【０２１０】
搬送ガイド５０７は、未定着のトナー画像５０８を担持しながら搬送される転写材５１６を定着ローラー５０１と加圧ローラー５０２との圧接部（ニップ部）へ案内する位置に配置される。
【０２１１】
分離爪５１０は、定着ローラー５０１の表面に当接または近接して配置されて、転写材５１６が定着ローラー５０１へ巻き付いてしまうのを防止する。
【０２１２】
励磁コイル５０３は、断面Ｔ型形状の磁性体コア５０４（以下コアと称す）の中央突起部に導線を巻き、定着ローラー内周面に沿わせるような構造になるように、ＰＰＳ、ＰＥＥＫ、フェノール樹脂等の耐熱性樹脂からなるホルダー５０５の外部に配置されている。この励磁コイル５０３には１０〜１００〔ｋＨｚ〕の交流電流が印加される。
【０２１３】
交流電流によって誘導された磁界は、高透磁率を有した磁界遮蔽手段としてのコア５０４に導かれて発熱手段としての定着ローラー５０１の内面に磁束と渦電流を発生させ、さらに定着ローラー５０１の固有抵抗により、ジュール熱が発生する。
【０２１４】
この発熱を増加させるためには励磁コイル５０３の巻き数を増やしたり、コア５０４をフェライト、パーマロイといった高透磁率で残留磁束密度の低いものを用いたり、交流電流の周波数を高くするとよい。
【０２１５】
なお、コア５０４は、定着ローラー５０１の回転軸方向に延びる断面Ｔ形状に構成されており、励磁コイル５０３により励磁して発生した磁界を遮断して、加熱部に向けて磁界を集中させるようになっている。
【０２１６】
以上のような構成で定着ローラー５０１の表面温度を定着に最適な所定の１９０℃で温調させると、励磁コイルには約２００Ｗ程度の電力供給が必要である。その時の励磁コイルの温度は約２１０〔℃〕、磁性体コアの温度は約２００〔℃〕になる。
【０２１７】
また１分間に３０枚程度の速度で連続で多量に定着したときには、励磁コイルには４５０〔Ｗ〕程度の電力供給が必要で、そのとき励磁コイルの温度は約２３０〔℃〕、磁性体コアの温度は約２２０〔℃〕になる。
【０２１８】
なお、以上の説明では加熱部材として定着ローラーを用いた場合を示したが、定着ローラーのかわりに薄膜金属フィルムからなる構成を採用することももちろん可能である。
【０２１９】
【実施例】
以下、具体的実施例によって本発明を説明する。
【０２２０】
実施例及び比較例で使用したワックスを表１に示した。ワックス１のＤＳＣ測定結果を図 に示す。
【０２２１】
次に結着樹脂を以下のように調製した。
【０２２２】
［樹脂組成物の製造例１］
低分子量重合体（Ｌ−１）の合成：
４つ口フラスコ内にキシレン３００質量部を投入し、攪拌しながら容器内を充分に窒素で置換した後、昇温して還流させる。
【０２２３】
この還流下で、スチレン７５質量部、アクリル酸−ｎ−ブチル１８質量部、マレイン酸モノブチル７質量部及びジ−ｔｅｒｔ−ブチルパーオキサイド２質量部の混合液を４時間かけて滴下した後、２時間保持し重合を完了し、低分子量重合体（Ｌ−１）溶液を得た。
【０２２４】
高分子量重合体（Ｈ−１）の合成：
４つ口フラスコ内に脱気水１８０質量部とポリビニルアルコールの２質量％水溶液２０質量部を投入した後、スチレン７０質量部、アクリル酸−ｎ−ブチル２５質量部、マレイン酸モノブチル５質量部、ジビニルベンゼン０．００５質量部、及び２，２−ビス（４，４−ジ−ｔｅｒｔ−ブチルパーオキシシクロヘキシル）プロパン（半減期１０時間温度；９２℃）０．１質量部の混合液を加え、攪拌し懸濁液とした。
【０２２５】
フラスコ内を十分に窒素で置換した後、８５℃まで昇温して、重合を開始した。同温度に２４時間保持した後、ベンゾイルパーオキサイド（半減期１０時間温度；７２℃）０．１質量部を追加添加した。さらに、１２時間保持して重合を完了した。その後、該高分子量重合体を濾別し、水洗、乾燥させた。
【０２２６】
樹脂組成物（Ｉ）の製造：
４つ口フラスコ内に、キシレン１００質量部と上記高分子量重合体（Ｈ−１）２５質量部を投入し、昇温して還流下で攪拌し、予備溶解を行なう。この状態で１２時間保持し、予備溶解液（Ｙ−１）を得た。
【０２２７】
一方、別容器に上記低分子量重合体（Ｌ−１）の均一溶液３００質量部を投入し、還流させる。上記予備溶解液（Ｙ−１）と低分子量重合体（Ｌ−１）溶液を還流下で混合した後、有機溶剤を留去し、得られた樹脂を冷却、固化後粉砕してトナー用結着樹脂組成物（Ｉ）を得た。
【０２２８】
該樹脂組成物（Ｉ）を分析したところ、ＧＰＣの分子量分布におけるメインピークはＭｗ＝１４７００、サブピークがＭｗ＝１０９万、ＴＨＦ不溶分は１．１質量％、酸価は２３ｍｇＫＯＨ／ｇであった。
【０２２９】
[樹脂組成物の製造例２〜５]
低分子量重合体（Ｌ−２〜３）の合成：
樹脂組成物の製造例１と同様に、マレイン酸モノブチル、スチレン、アクリル酸ｎ−ブチル量及び開始剤量を調整し、低分子量重合体Ｌ−２〜３を得た。
【０２３０】
高分子量重合体（Ｈ−２）の合成：
高分子量重合体（Ｈ−１）の合成と同様に、マレイン酸モノブチル、スチレン、アクリル酸ｎ−ブチル量及び開始剤量を調整し、高分子量重合体（Ｈ−２）を得た。
【０２３１】
高分子量重合体Ｈ−３の合成：
４つ口フラスコにスチレン８５質量部とメタアクリル酸ブチル１５質量部を投入し、塊状重合させた後、キシレンを添加し溶媒存在下で溶液重合を完了し、高分子量重合体（Ｈ−３）を得た。
【０２３２】
樹脂組成物（ＩＩ）〜（ＩＶ）の製造：
高分子量重合体Ｈ−１〜３と低分子量重合体Ｌ−１〜３を表２に示すように組み合わせ、樹脂組成物の製造例１と同様にして樹脂組成物（ＩＩ）〜（ＩＶ）を得た。その分子量分布等の結果を表２に示す。
【０２３３】
樹脂組成物（Ｖ）の製造：
マレイン酸モノブチルを使用せず、ジビニルベンゼン及び開始剤量を調整し、低分子量重合体（Ｌ−１）の合成と同様にして分子量分布におけるピークが一つの、樹脂組成物（Ｖ）を得た。
【０２３４】
＜実施例１＞
・樹脂組成物Ｉ １００質量部
・マグネタイト（平均粒径０．２５μｍ） １００質量部
・例示のアゾ系鉄錯体化合物（１） ２質量部
・ワックス１ ３質量部
・ワックス１０ ３質量部
上記原材料をヘンシェルミキサーで予備混合した後、１２０℃に設定した二軸混練押し出し機によって混練し、得られた混練物を冷却しカッターミルで粗粉砕し、粗砕物である粉体原料Ａを得た。
【０２３５】
粉体原料Ａを図２に示す装置システムで粉砕及び分級を行った。機械式粉砕機３０１には、ターボ工業（株）製ターボミルＴ−２５０型を用い、図３に示す回転子３１４と固定子３１０の間隔を１．５ｍｍとし、回転子３１４の周速を１１５ｍ／ｓで運転した。
【０２３６】
本実施例では、テーブル式の第１定量供給機３１５にて粗粉砕物からなる粉体原料を、４０ｋｇ／ｈの割合で機械式粉砕機３０１に供給し、粉砕した。機械式粉砕機３０１で粉砕された粉体原料は、排気ファン２２４からの吸引エアーに同伴されながらサイクロン２２９にて補集され、第２定量供給機２へと導入される。なお、このとき機械式粉砕機内の入口温度は−１０℃、出口温度は４７℃、入口温度と出口温度の温度差ΔＴは５７℃であった。また、この時に機械式粉砕機３０１で粉砕されて得られた微粉砕品Ａ−１は、重量平均径が６．５μｍであり、粒径４．０μｍ以下の粒子が４２．３個数％、且つ粒径１０．１μｍ以上の粒子を３．４体積％含有するシャープな粒度分布を有していた。
【０２３７】
次に、上記の機械式粉砕機３０１で粉砕されて得られた微粉砕品Ａ−１を、第２定量供給機２に導入し、振動フィーダー３、原料供給ノズル１６を介して４４ｋｇ／ｈの割合で図６の構成を有する気流式分級機１に導入した。該気流式分級機１では、コアンダ効果を利用して、粗粉体、中粉体及び微粉体の３種の粒度に分級される。気流式分級機１への導入に際しては、排出口１１、１２及び１３の少なくとも１つを介して分級室内を減圧し、分級室内に開口部を有する原料供給ノズル１６中を該減圧によって流動する気流と、高圧エアー供給ノズル４１から噴射される圧縮エアーを利用した。導入された微粉砕品は、０．１秒以下の瞬時に、粗粉体、中粉体Ａ−２及び微粉体の３種に分級された。分級されたもののうち、粗粉体は補集サイクロン６で補集した後、先に説明した機械式粉砕機３０１に２．０ｋｇ／ｈの割合で導入し、再度粉砕工程に導入した。
【０２３８】
上記の分級工程で分級された中粉体Ａ−２（分級品）は、重量平均径が６．８μｍであり、粒径４．０μｍ以下の粒子が２０．５個数％、且つ粒径１０．１μｍ以上の粒子を２．７体積％含有するシャープな粒度分布を有していた。
【０２３９】
この中粉体Ａ−２１００質量部に対して、疎水性シリカ微粉体（ＢＥＴ１２０ｍ²／ｇ）１．０質量部と円相当径１．８μｍのチタン酸ストロンチウム０．８質量部を、ヘンシェルミキサー（ＦＭ−７５型、三井三池化工機（株）製）にて外添添加してトナー１とした。トナー１のＤＳＣ測定結果を図１２に示す。
【０２４０】
このトナー１の定着試験と尾引きの評価の結果を表４に示す。その結果、良好な定着特性が得られ、尾引きの発生もなかった。
【０２４１】
（低温定着性及び耐コールドオフセット性試験）
図１２に示した電磁誘導方式による定着装置の定着温度を任意に設定できるようにし、プロセススピードを１００ｍｍ／ｓｅｃ、加圧力を８３Ｎ、ニップが６ｍｍとなるようにした外部定着器を用いた。１５℃，１０％ＲＨ環境下で、外部定着器を１３０〜２００℃の温度範囲で５℃おきに温調し、それぞれの温度で９０ｇ／ｍ²のボンド紙に１ドット２スペースのハーフトーン画像を現像した未定着画像の定着を行い、得られた画像を４．９ｋＰａの荷重をかけたシルボン紙で５往復摺擦し、摺擦前後の画像濃度の濃度低下率が５％以下になる点を定着温度とした。この温度が低いほど低温定着性に優れたトナーである。
【０２４２】
耐コールドオフセット性については、上記定着試験で画像上にオフセット現象による汚れが発生した温度を目視で確認した。この温度が低いほど耐コールドオフセット性に優れたトナーである。
【０２４３】
（尾引き）
低温定着性及び耐コールドオフセット性試験で用いた外部定着装置を定着温度２１０℃に設定し、７５ｇ／ｍ²紙を３２．５℃，８０％ＲＨ環境下に一日放置したものを用いた。
【０２４４】
尾引きの評価方法は、上記高湿環境放置紙に４ドットの横ラインを２０ドットスペースに印字したパターンを１枚画出しし、上記設定の外部定着器に通紙し、ライン上で尾引いた数を数えた。
◎ ：発生なし
○ ：３個未満
○△：３〜７個未満
△ ：７〜１０個未満
△×：１０〜１５未満
× ：１５個以上
【０２４５】
＜実施例２〜１４、参考例１５〜１８、実施例１９及び比較例１〜２＞
樹脂組成物とワックス、トナー粒径、及び外添剤としてのチタン酸ストロンチウムの添加量を表３に示した様に変える以外は実施例１と同様にして、トナー２〜２１を得、実施例１と同様に評価を行った。トナー重量平均粒径Ｄ４（μｍ）と円形度０．９５０以上のトナー粒子の個数基準累積値（％）の関係を、図１３及び１４に示した。これらのトナーの定着試験と尾引きの評価の結果を表４に示す。
【０２４６】
【表１】

【０２４７】
【表２】

【０２４８】
【表３】

【０２４９】
【表４】

【０２５０】
【発明の効果】
本発明によれば、前述したような構成の画像形成方法とトナーを組み合わせることで、低温環境におけるハーフトーン画像の低温定着性と耐コールドオフセット性にすぐれ、かつ高湿環境で尾引きの起こらないトナー及び画像形成方法を提供することができる。
【図面の簡単な説明】
【図１】本発明のトナーの製造方法を説明する為のフローチャートである。
【図２】本発明のトナーの製造方法を実施する為の装置システムの一具体例を示す概略図である。
【図３】本発明のトナーの粉砕工程において使用される一例の機械式粉砕機の概略断面図である。
【図４】図３におけるＤ−Ｄ’面での概略的断面図である。
【図５】図３に示す回転子の斜視図である。
【図６】本発明のトナーの分級工程に用いられる多分割気流式分級装置の概略断面図である。
【図７】従来の衝突式気流粉砕機の概略断面図である。
【図８】本発明の実施の形態に係わる定着装置の概略構成断面図である。
【図９】本発明の実施の形態に係わる定着装置の概略構成断面図である。
【図１０】本発明の実施の形態に係わる定着装置の概略構成断面図である。
【図１１】ワックス１の昇温時のＤＳＣ曲線である。
【図１２】トナー１の昇温時のＤＳＣ曲線である。
【図１３】トナー重量平均粒径Ｄ４（μｍ）と円形度０．９５０以上のトナー粒子の個数基準累積値（％）の関係を示す図である。
【図１４】トナー重量平均粒径Ｄ４（μｍ）と円形度０．９５０以上のトナー粒子の個数基準累積値（％）の関係を示す図である。
【符号の説明】
１ ：多分割分級機
２ ：第２定量供給機
３ ：振動フィーダー
４，５，６ ：補集サイクロン
１１，１２，１３ ：排出口
１１ａ，１２ａ，１３ａ ：排出導管
１４，１５ ：入気管
１６ ：原料供給ノズル
１７，１８ ：分級エッジ
１９ ：入気エッジ
２０ ：第１気体導入調節手段
２１ ：第２気体導入調節手段
２２，２３ ：側壁
２４，２５ ：分級エッジブロック
２６ ：コアンダブロック
２７ ：左部ブロック
２８，２９ ：静圧計
３０ ：分級域
３２ ：分級室
４０ ：原料供給口
４１ ：高圧エアーノズル
４２ ：原料粉体導入ノズル
６５ ：インジェクションフィーダー
１６１ ：高圧気体供給ノズル
１６２ ：加速管
１６３ ：加速管出口
１６４ ：衝突部材
１６５ ：原料供給口
１６６ ：衝突面
１６７ ：粉砕物排出口
２１２ ：渦巻室
２１９ ：パイプ
２２０ ：ディストリビュータ
２２２ ：バグフィルター
２２４ ：吸引フィルター
２２９ ：補集サイクロン
３０１ ：機械式粉砕機
３０２ ：粉体排出口
３１０ ：固定子
３１１ ：粉体投入口
３１２ ：回転軸
３１３ ：ケーシング
３１４ ：回転子
３１５ ：第１定量供給機
３１６ ：ジャケット
３１７ ：冷却水供給口
３１８ ：冷却水排出口
３２０ ：後室
３２１ ：冷風発生手段
５０１ ：回転加熱部材（定着ローラ）
５０２ ：回転加圧部材（加圧ローラ）
５０３ ：励磁コイル（磁界発生手段）
５０４ ：コア
５０５ ：ホルダー
５０６ ：温度センサー
５０７ ：搬送ガイド
５０８ ：トナー画像
５１０ ：分離爪
５１１ ：発熱層
５１２ ：離型層
５１３ ：定着画像
５１４ ：中空芯金
５１５ ：弾性層
５１６ ：転写材（記録材）
Ｎ ：ニップ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toner used in an image forming method such as electrophotography, electrostatic recording, electrostatic printing, and toner jet, and an image forming method using the toner.
[0002]
[Prior art]
Conventionally, as an electrophotographic method, many methods are known as described in US Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910, Japanese Patent Publication No. 43-24748, and the like.
[0003]
In general, a photoconductive material is used to form an electrical latent image on a photoreceptor, and then the latent image is developed with toner, and the toner image is transferred to a transfer material such as paper as necessary. After that, it is fixed by heating, pressure, heating pressure or solvent vapor to obtain a copy. The toner remaining without being transferred onto the photoreceptor is cleaned by various methods, and the above-described steps are repeated. Examples of this type of image forming apparatus include a copying machine, a printer, or a facsimile machine.
[0004]
Conventionally, various methods and apparatuses have been developed for fixing a toner image on a sheet such as paper. The most common method at present is a pressure heating method using a heat roller.
[0005]
The pressure heating method using a heating roller is a method in which fixing is performed by allowing the toner image surface of a fixing sheet to pass through the surface of a heat roller formed with a material having releasability with respect to the toner while being in contact with pressure. is there. In this method, since the surface of the heat roller and the toner image of the fixing sheet are in contact with each other under pressure, the thermal efficiency when fusing the toner image on the fixing sheet is extremely good, and the fixing can be performed quickly. This is very effective in a high-speed electrophotographic copying machine.
[0006]
However, the hot roll fixing has the following points to be improved.
(1) The wait time until the heat roller reaches the predetermined temperature (image formation operation inhibition time) is long.
(2) The heating roller is set to an appropriate temperature in order to prevent a fixing failure due to the passage of the recording material or the temperature of the heating roller due to other external factors and to prevent an offset phenomenon to the heating roller. Need to be maintained. For this purpose, it is necessary to increase the heat capacity of the heating roller or the heating body, which requires a large amount of electric power.
(3) Since the heating roller is hot and the ambient temperature is high, the recording material and the toner on the recording material are slowly cooled after the recording material passes through the heating roller. In some cases, a high-quality state is maintained, and an offset to the roller or a paper jam due to the recording material being wound around the roller may occur.
[0007]
In order to solve such problems, Japanese Patent Publication No. 7-82250, Japanese Patent Publication No. 8-12454 to 8-12461, Japanese Patent Publication No. 8-12476, Japanese Patent Publication No. 8-16804, Japanese Patent Registration No. 2660075 In Japanese Patent Registration No. 2746475, Japanese Patent Registration No. 2774536, Japanese Patent Registration No. 2774537, Japanese Patent Registration No. 282156, etc., a visible image of toner, a recording material, a heating member fixedly supported on the recording material, and a counter pressure contact with the heating body In addition, a heat fixing method and a toner used in the heat fixing method are disclosed, in which the recording material is heat-fixed by a pressure member that closely contacts the heating body via a film. However, there is a need for further energy saving and shortening of the wait time.
[0008]
In JP-A-9-204110, JP-A-9-319242, JP-A-10-48868, JP-A-10-161444, etc., a film having a conductive portion and a support member for supporting the film, Electromagnetic induction for generating an eddy current in the film by the magnetic flux generated by the magnetic flux generation means and heating the image on the recording material by the heat of the film generated by the eddy current A fixing device based on this method is disclosed.
[0009]
This fixing method saves energy, shortens the wait time, and does not cause fixing temperature unevenness in the recording material, so that there is little fixing unevenness (gross difference) of the fixed image, and high-quality or color images can be fixed.
[0010]
However, the pressure applied to the recording material is limited as compared with other fixing methods, while the performance required for the toner has become higher.
[0011]
One of the problems is that the low-temperature fixability and cold offset resistance in a halftone image are likely to deteriorate particularly in a low-temperature environment, and further, the tailing is likely to deteriorate in a high-humidity environment. Trailing is a phenomenon in which the toner image explodes at the fixing nip portion as if it explodes downstream in the transfer material conveyance direction, and is heated from the recording material such as paper by being heated at the nip portion of the rotating heating member and the rotating pressure member. It is thought that this is caused by a sudden flow of water vapor that blows away the toner.
[0012]
Both of these problems are more prominent by using an electromagnetic induction type fixing device than when other fixing methods are used.
[0013]
As a technique for imparting low-temperature fixability and offset resistance to a toner, means containing a low softening point release agent (wax) made of polyolefin or the like is known.
[0014]
For example, in JP-A-51-14333, JP-A-57-14875, JP-A-58-97056, JP-A-60-247250, JP-A-6-230600, etc. Addition of solid silicone varnish, higher fatty acid wax, higher alcohol wax, plant natural wax (carnauba wax, rice wax), montan ester wax and the like is known as an agent. In the fixing device using the induction method, the low-temperature fixing property and the cold offset resistance in the halftone image are insufficient.
[0015]
In general, when such a low softening point release agent is contained in the toner, the fluidity is lowered, so that the developability and transferability are lowered. It is also known to adversely affect charging characteristics, durability, and storage stability.
[0016]
Further, as a toner containing two or more kinds of waxes in order to exert the effect of adding wax from a low temperature region to a high temperature region, for example, Japanese Patent Laid-Open Nos. 52-3305 and 58-215659 are disclosed. Japanese Laid-Open Patent Publication Nos. 62-1000077, JP-A-4-124676, JP-A-4-299357, JP-A-4-362953, and JP-A-5-197192 are disclosed.
[0017]
However, even with these toners, not all performances can be satisfied when applied to the electromagnetic induction type fixing device used in the present invention.
[0018]
In addition, JP-A-8-278657, JP-A-8-334919, JP-A-8-334920 and the like describe two or more kinds of wax components in order to obtain a toner having excellent low-temperature fixability and offset resistance. It has been proposed to contain toner in the toner.
[0019]
However, although the range of low-temperature fixability and high-temperature offset property certainly expands with toners using these release agents, electromagnetic induction-type fixing devices have sufficient low-temperature fixability and cold offset resistance in halftone images. Not.
[0020]
Further, as a technique relating to the improvement of the binder resin of toner, for example, Japanese Patent Publication No. 51-23354 proposes a toner using a crosslinked polymer as a binder resin. According to the method, there is an effect in improving the offset resistance and the wrapping resistance, but on the other hand, the fixing temperature rises when the degree of cross-linking increases, and the fixing temperature is sufficiently low and the offset resistance and wrapping property are good. In addition, it is difficult to obtain sufficient fixing characteristics.
[0021]
In general, in order to improve the fixing property, the binder resin must be lowered in molecular weight to lower the softening point, which is contrary to the offset resistance improving treatment. In order to obtain a low softening point, the glass transition point of the resin is inevitably lowered, and an undesired phenomenon that the toner during storage is blocked occurs.
[0022]
On the other hand, Japanese Patent Application Laid-Open No. 56-158340 proposes a toner comprising a low molecular weight polymer and a high molecular weight polymer. Although this binder resin is improved in terms of fixability, it is still insufficient in terms of offset resistance, and it is difficult to highly satisfy offset resistance and fixability.
[0023]
Japanese Patent Application Laid-Open Nos. 58-203453 and 60-20411 propose a method for producing a toner and a resin composition comprising a low-temperature softening resin and a high-temperature softening resin. Although this binder resin is improved in terms of offset resistance, it is still insufficient in terms of fixability, and it is difficult to highly satisfy offset resistance and fixability.
[0024]
Further, regarding a toner blended with a low molecular weight polymer and a crosslinked polymer, for example, Japanese Patent Application Laid-Open No. 58-86558 proposes a toner having a low molecular weight polymer and an infusible high molecular weight polymer as main resin components. Yes. According to this method, the fixability and grindability tend to be improved, but the weight average molecular weight / number average molecular weight (Mw / Mn) of the low molecular weight polymer is as small as 3.5 or less and insoluble and infusible. When the content of the high molecular weight polymer is as high as 40 to 90% by mass, it is difficult to satisfy both offset resistance and grindability with high performance. In practice, it is extremely difficult to produce a toner that sufficiently satisfies fixing properties (particularly, high-speed fixing), offset resistance and pulverization properties unless the fixing device has an offset prevention liquid supply device.
[0025]
JP-A-56-16144 discloses a molecular weight distribution of 1 × 10 in GPC molecular weight distribution.^Three~ 8x10^FourAnd molecular weight 1 × 10^Five~ 2x10⁶A toner containing a binder resin component having at least one maximum value in each region has been proposed, but further improvements in low-temperature fixability and offset resistance are required.
[0026]
Japanese Patent Application Laid-Open No. 63-223661 contains 10 to 60% by mass of a THF-insoluble component based on the binder resin, and the molecular weight distribution by GPC of the THF-soluble component is weight average molecular weight / number average molecular weight (Mw / Mn). Is 5 or more, and the molecular weight is 2 × 10^Three~ 1x10^FourAnd has a molecular weight of 1.5 × 10^Four~ 1x10^FiveWith a peak or shoulder in the region of 1 and a molecular weight of 1 × 10^FourA toner containing 10 to 50% by mass of the following components in a binder resin has been proposed.
[0027]
In this case, the grindability, fixability, filming and fusion to the photoconductor, image quality, and offset resistance (especially offset resistance on the high temperature side) are excellent, but further low temperature fixability and offset resistance. Improvement is required.
[0028]
Furthermore, in JP-A-2-168264, JP-A-2-23569, JP-A-5-173363, and JP-A-5-241371, the molecular weights of the low molecular weight component and the high molecular weight component in the binder resin are as follows: Binder compositions and toners for toners have been proposed in which the mixing ratio, acid value, and ratio thereof are controlled to improve fixability, offset resistance, image characteristics and blocking resistance, charge rise characteristics, and the like. There is a demand for improved low-temperature fixability and offset resistance.
[0029]
Further, in place of these vinyl resins, a toner obtained by crosslinking a polyester resin, which is essentially superior to a vinyl resin in terms of low-temperature fixing, and further adding an offset preventing agent, is disclosed in JP This is proposed in Japanese Patent Application No. 57-208559. This is excellent in both low-temperature fixability and offset prevention to some extent, but has a problem in terms of productivity (grindability) as a toner.
[0030]
Furthermore, Japanese Patent Application Laid-Open No. 56-116043 uses a resin obtained by polymerizing a vinyl monomer in the presence of a reactive polyester and polymerizing it through a crosslinking reaction, an addition reaction, and a grafting reaction in the polymerization process. Toner has been proposed and improved in terms of pulverization, but the functions of the resins cannot be fully utilized in terms of low-temperature fixability and offset prevention.
[0031]
Japanese Patent Publication No. 1-15063 proposes a toner using a resin that is simply blended with two types of vinyl resins having a gel content different from that of a polyester resin (gelation degree of 80% or more and gelation degree of less than 10%). This is good in terms of low-temperature fixability, but is still not sufficient in terms of offset prevention and grindability. Even if the proportion of the vinyl resin having a gelation degree of 80% or more is increased for the purpose of improving the offset resistance, the offset resistance is improved, but conversely the low-temperature fixability is remarkably lowered. Moreover, sufficient pulverizability cannot be obtained simply by including a vinyl resin having a gelation degree of less than 10%.
[0032]
Japanese Patent Laid-Open No. 3-72505 discloses a vinyl toner binder having a molecular weight of 300,000 or more using a polyfunctional initiator. When such a resin is used, the fixability is excellent to some extent. There is a demand for further improvements in low-temperature fixability and offset resistance.
[0033]
[Problems to be solved by the invention]
An object of the present invention is to provide a toner that solves the above-described problems and an image forming method using the toner.
[0034]
That is, an object of the present invention is to provide a toner that exhibits good low-temperature fixability and cold offset resistance even in a halftone image and does not cause tailing in an electromagnetic induction type fixing device, and an image forming method using the toner. There is.
[0035]
[Means for Solving the Problems]
  The present invention includes (i) a magnetic field generating means, (ii) a rotary heating member having at least a heat generating layer and a release layer that generate heat by electromagnetic induction, and (iii) a rotary heating member that forms a nip with the rotary heating member. A toner applied to an image forming method for forming a fixed image on a recording material by heating and fixing a toner image on the recording material while pressing the rotary heating member through the recording material with a pressure member;
  The toner contains at least a binder resin and a wax component, and the peak top temperature (P1) of the maximum endothermic peak is in the range of 70 to 120 ° C. in the DSC curve at the time of temperature rise measured by a differential scanning calorimeter of the toner. And at least one peak top temperature (P2) of an endothermic peak exists in the range of 120 to 160 ° C.And
  In addition, in the toner having a weight average particle diameter of 5 to 12 μm and a particle of 3 μm or more of the toner, 90% or more of particles having a circularity a = 0.900 or more obtained from the following formula are accumulated based on the number. Have
      Circularity a = L ₀ / L
(Where L ₀ Indicates the perimeter of a circle having the same projected area as the particle image, and L indicates the perimeter of the particle image. )
  And,
  a) The relationship between the cut rate Z and the toner weight average diameter X is
      Cut rate Z ≦ 5.3 × X
[However, the cut rate Z is expressed by the following formula when the total number of particles is A and the number of measured particles of 3 μm or more is B..
      Z = (1-B / A) × 100]
And the relationship between the number-based cumulative value Y of particles having a circularity of 0.950 or more and the toner weight average diameter X is
  Number-based cumulative value Y ≧ exp5.51 × X of particles having a circularity of 0.950 or more ^-0.645
[However, toner weight average diameter X: 5.0 to 12.0 (μm)]
Or
  b) The relationship between the cut rate Z and the toner weight average diameter X is
      Cut rate Z> 5.3 × X
And the relationship between the number-based cumulative value Y of particles having a circularity of 0.950 or more and the toner weight average diameter X is
  Number-based cumulative value Y ≧ exp5.37 × X of particles having a circularity of 0.950 or more ^-0.545
[However, toner weight average diameter X: 5.0 to 12.0 (μm)]
SatisfyThis invention relates to a toner.
[0036]
  Furthermore, the present invention is an image forming method for forming a fixed image on a recording material by heating and fixing a toner image on the recording material by a heating and pressing unit,
  The toner forming the toner image contains at least a binder resin and a wax component, and the peak top temperature (P1) of the maximum endothermic peak in the DSC curve at the time of temperature rise measured by a differential scanning calorimeter of the toner is Exists in the range of 70 to 120 ° C., and at least one peak top temperature (P2) of the endothermic peak exists in the range of 120 to 160 ° C.,
  In addition, in the toner having a weight average particle diameter of 5 to 12 μm and a particle of 3 μm or more of the toner, 90% or more of particles having a circularity a = 0.900 or more obtained from the following formula are accumulated based on the number. Have
      Circularity a = L ₀ / L
(Where L ₀ Indicates the perimeter of a circle having the same projected area as the particle image, and L indicates the perimeter of the particle image. )
  And,
  a) The relationship between the cut rate Z and the toner weight average diameter X is
      Cut rate Z ≦ 5.3 × X
[However, the cut rate Z is expressed by the following formula, where A is the total number of particles measured by Toago Medical Electronics' flow type particle image analyzer FPIA-1000, and B is the number of particles measured 3 μm or more.
      Z = (1-B / A) × 100]
And the relationship between the number-based cumulative value Y of particles having a circularity of 0.950 or more and the toner weight average diameter X is
  Number-based cumulative value Y ≧ exp5.51 × X of particles having a circularity of 0.950 or more ^-0.645
[However, toner weight average diameter X: 5.0 to 12.0 (μm)]
Or
  b) The relationship between the cut rate Z and the toner weight average diameter X is
      Cut rate Z> 5.3 × X
And the relationship between the number-based cumulative value Y of particles having a circularity of 0.950 or more and the toner weight average diameter X is
  Number-based cumulative value Y ≧ exp5.37 × X of particles having a circularity of 0.950 or more ^-0.545
[However, toner weight average diameter X: 5.0 to 12.0 (μm)]
Satisfied,
  The heating and pressing means includes (i) a magnetic field generating means, (ii) a rotary heating member having at least a heat generating layer and a release layer that generate heat by electromagnetic induction, and (iii) forming a nip with the rotary heating member. The present invention relates to an image forming method comprising: forming a fixed image on a recording material by heating and fixing a toner image on the recording material while pressing the rotary heating member with the rotating pressure member being pressed.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
The electromagnetic induction type fixing device has a quick rise in temperature of the rotating heating member, and printing is possible in a very short preheating time compared to the heat roll fixing method. (Cold start), especially in a low temperature environment, the fixing unit is very cold, so the heat temperature cannot be sufficiently transferred to the rotating pressure member due to the short preheating time, and the surface temperature of the rotating pressure member Is hard to go up. Therefore, the amount of heat for heating the toner image developed on the recording material from the back side of the recording material is reduced, and only the toner on the surface in contact with the rotating heating member melts and adheres to the rotating heating member, and the toner peels off from the recording material. Cold offset. In particular, a halftone image or the like has a small amount of developed toner, and it is difficult to obtain an adhesive force between toner particles, so that fixability is easily deteriorated and cold offset is likely to occur. This is particularly noticeable when a thick paper such as bond paper with a non-smooth surface is used. In order to ensure sufficient fixability and cold offset resistance even in halftone images, etc., if the temperature of the rotating heating member at the cold start is set high, a water vapor flow is likely to be generated from the recording material particularly in a high humidity environment, The tail gets worse. In other words, it has been extremely difficult for the electromagnetic induction type fixing device to satisfy both the low temperature fixing property and the cold offset resistance in a low temperature environment and the tailing in a high humidity environment at the same time.
[0038]
Accordingly, as a result of intensive studies by the present inventors, the toner contains at least a binder resin and a wax component, and the maximum endothermic peak of the toner in the DSC curve at the time of temperature rise measured by a differential scanning calorimeter of the toner is shown. The peak top temperature (P1) is in the range of 70 to 120 ° C. (preferably 70 to 110 ° C., more preferably 70 to 100 ° C., further preferably 70 to 90 ° C., most preferably 70 to 80 ° C.), and 120 to 160 A toner characterized by containing a wax component such that at least one peak top temperature (P2) of an endothermic peak exists in the range of 1 ° C. (preferably 120 to 150 ° C., more preferably 130 to 150 ° C.). , It was found to be very effective in these problems.
[0039]
When printing is performed with a cold start by an electromagnetic induction type fixing device in a low temperature environment, the surface temperature of the rotary pressure member rises only to about 120 ° C. before the recording material enters, but the rotary heating member exceeds 200 ° C. Until heated. At this time, the toner having the endothermic peak in the above temperature range adheres the toner and the recording material because the wax having the endothermic peak on the low temperature side can be sufficiently melted even with a small amount of heat from the rotary pressure member side on the back side of the recording material. Demonstrate the effect. In addition, the toner in contact with the rotating heating member promotes the melting of the wax on the toner surface by melting both the wax having the endothermic peak on the low temperature side and the high temperature side, and strong separation between the rotating heating member and the toner. Exhibits mold effect and prevents offset. As described above, the wax exhibits an effect on both the low temperature side and the high temperature side, thereby improving the cold offset resistance and the low temperature fixability. Also, with regard to tailing that tends to occur in a high humidity environment, when heated at the fixing nip, wax having an endothermic peak on the low temperature side quickly melts on the toner surface, and the toner particles and the toner particles and the recording material are joined together. Since it functions to fix the toner image, even if a water vapor flow is abruptly generated from a recording material such as paper, the toner image is not easily disturbed and is not easily blown away, so that tailing can be suppressed.
[0040]
When the peak end temperature (P1) of the maximum endothermic peak is lower than 70 ° C., the viscosity of the melted wax becomes too low, the releasing effect cannot be obtained, and the cold offset resistance is deteriorated. When the temperature is higher than 120 ° C., the wax is not easily melted by a small amount of heating from the rotating pressure member side on the back surface of the recording material, and the low temperature fixing property, cold offset resistance and tailing in a halftone image are deteriorated.
[0041]
In addition, even when the peak top temperature (P2) of the endothermic peak is lower than 120 ° C., the viscosity of the melted wax becomes too low, the releasing effect cannot be obtained, and the cold offset resistance is deteriorated. When the temperature is higher than 160 ° C., the wax becomes difficult to melt at the time of fixing, and low temperature fixing property, cold offset resistance and tailing are deteriorated.
[0042]
The toner of the present invention has a peak end temperature of 70 to 120 ° C. (preferably 70 to 110 ° C., more preferably 70 to 100 ° C., and still more preferably) in the endothermic peak at the time of temperature rise measured by DSC. The peak top temperature of the maximum endothermic peak is 120 to 160 ° C. (preferably 120 to 150 ° C. in the endothermic peak at the time of temperature rise measured by DSC and wax A which is 70 to 90 ° C., most preferably 70 to 80 ° C. , More preferably 130-150 ° C.).
[0043]
Such a wax A component easily dissolves on the toner surface when the toner is heated during fixing, and enhances the effect of connecting the toner particles to each other and the toner particles and the recording material, so that tailing and cold offset occur. It is effective in easy-to-use situations and improves low-temperature fixability. Also, by including both the wax A component and the wax B component, the wax is more easily dissolved on the toner surface than when a single type of wax is present alone, and tailing, low temperature fixability, and cold offset resistance are achieved. Improved.
[0044]
When the peak end temperature of the maximum endothermic peak of the wax A component is lower than 70 ° C., the wax tends to excessively plasticize the binder resin, and the releasability from the rotating heating member is deteriorated. It is easy to get worse. When the peak top temperature of the maximum endothermic peak is higher than 120 ° C., the wax component hardly dissolves on the toner surface, and the effects on tailing, low-temperature fixability, and cold offset resistance are reduced.
[0045]
Moreover, when the peak top temperature of the maximum endothermic peak of the wax B component is lower than 120 ° C., it is difficult to obtain a releasing effect on the rotary heating member, and the cold offset resistance is likely to deteriorate. When the peak top temperature of the maximum endothermic peak is higher than 160 ° C., the wax B component is difficult to melt at the time of fixing, and there is a possibility that tailing, cold offset resistance, and low-temperature fixing property are deteriorated.
[0046]
The toner of the present invention uses a wax A component having a peak half-value width of 12 ° C. or less, preferably 10 ° C. or less, more preferably 8 ° C. or less at the endothermic peak at the time of temperature rise measured by DSC. Is good.
[0047]
Since the wax A component having this half-value width is easily dissolved on the toner surface, an excellent effect can be obtained even with a small addition amount. Further, even if the amount added is increased, the toner storage stability is not adversely affected, so that the effect can be further increased. If the full width at half maximum is greater than 12 ° C., it is difficult for the toner to dissolve on the toner surface, and tailing and low-temperature fixability may deteriorate.
[0048]
The toner of the present invention has an end point onset temperature of 50 ° C. or higher (more preferably 60 ° C. or higher) and an end point onset temperature of 100 ° C. or lower (more preferably 90 ° C.) at the endothermic peak at the time of temperature rise measured by DSC. It is preferable to use a wax A component that is equal to or lower than ° C. Since such a wax A component does not contain much low molecular weight wax component that plasticizes the binder resin component, it easily moves through the resin and easily dissolves on the toner surface. There is an effect to improve the nature.
[0049]
When the starting point onset temperature is less than 50 ° C., tailing, low-temperature fixability, and cold offset resistance are likely to deteriorate. When the end point onset temperature exceeds 100 ° C., the wax A component hardly dissolves on the toner surface, and the effect may be reduced.
[0050]
<DSC measurement method>
In the DSC measurement in the present invention, for example, DSC-7 manufactured by Perkin Elmer, DSC2920MDSC manufactured by TA Instruments, or the like can be used.
[0051]
The measurement method is performed according to ASTM D3418-82. The DSC curve used in the present invention is the DSC curve measured at the time of the second temperature increase after the temperature is increased once and the previous history is taken and then the temperature is decreased at a temperature rate of 10 ° C./min. Each temperature is defined as follows.
[0052]
・ Peak top temperature of maximum endothermic peak:
Peak top temperature of the highest peak from the baseline.
・ Half width of maximum endothermic peak:
Peak temperature range at half the height of the endothermic peak from the baseline to the peak top
・ End-point onset temperature of endothermic peak:
Temperature at the intersection of the tangent and baseline of the curve at the point where the differential value of the curve during temperature rise is maximum
・ End point onset temperature of endothermic peak:
Temperature at the intersection of the tangent line of the curve and the baseline at the point where the differential value of the curve during temperature rise is minimum
[0053]
Further, the toner of the present invention has a melt viscosity at 120 ° C. measured by an E-type viscometer of 100 mPa · s or less (preferably 1 to 50 mPa · s, more preferably 1 to 30 mPa · s, and further preferably 1 to 15 mPa · s). It is preferable to have a wax A component which is s). Such a low-viscosity wax is easy to move when the toner is heated and the wax is melted, so that the effect is easy to be exerted because the wax easily dissolves on the toner surface. When the melt viscosity is higher than 100 mPa · s, the fixing device used in the present invention is not effective because the wax does not easily dissolve on the toner surface, and is effective for tailing, low-temperature fixability, and cold offset resistance. Is difficult to obtain.
[0054]
<Measurement of viscosity of wax component>
The melt viscosity of the wax component is measured using an E-type rotational viscometer. As the viscometer, VT-500 (manufactured by HAAKE) was used. In the embodiment, VT-500 is used, the measurement temperature is adjusted to 120 ° C. with an oil bath with a temperature regulator, PK 1,0.5 ° is used for the sensor, and the share rate is 6,000 s^-1Measured with
[0055]
The following can be used for the wax used in the present invention. Examples thereof include compounds such as polyolefin wax, polyethylene wax, microcrystalline wax, carnauba wax, Fischer-Tropsch wax, paraffin wax, higher alcohol wax, ester wax, and oxides and graft modified products thereof.
[0056]
Preferred waxes include polyolefins obtained by radical polymerization of olefins under high pressure; polyolefins obtained by purifying low molecular weight by-products obtained during polymerization of high molecular weight polyolefins; polymerized using catalysts such as Ziegler catalysts and metallocene catalysts under low pressures Polyolefins; polyolefins polymerized using radiation, electromagnetic waves, light, etc .; low molecular weight polyolefins obtained by thermal decomposition of high molecular weight polyolefins; paraffin wax, microcrystalline wax, Fischer-Tropsch wax; Jintole method, hydrocol method, age method Synthetic hydrocarbon waxes synthesized by, etc .; synthetic waxes using a compound having one carbon atom as a monomer, hydrocarbon waxes having functional groups such as hydroxyl groups and carboxyl groups; hydrocarbon waxes and functional groups And the like a mixture of a hydrocarbon wax that.
[0057]
In addition, these waxes have a sharp molecular weight distribution using a press perspiration method, a solvent method, a recrystallization method, a vacuum distillation method, a supercritical gas extraction method, a fused liquid crystal deposition method, etc., and low molecular weight solid fatty acids, Low molecular weight solid alcohol, low molecular weight solid compound, and other impurities are preferably used.
[0058]
Particularly preferably used as the wax A are paraffin wax, Fischer-Tropsch wax, polyethylene synthesized using a metallocene catalyst, distillation products of low molecular weight by-products obtained during the polymerization of polyethylene, and the like.
[0059]
Particularly preferably used as the wax B is Fischer-Tropsch wax, low molecular weight polyolefin wax obtained by thermally decomposing high molecular weight polyolefin, and the like.
[0060]
Also, particularly preferred combinations of wax A and wax B are Fischer-Tropsch wax and polyolefin wax, paraffin wax and polyolefin wax, and paraffin wax and Fischer-Tropsch wax.
[0061]
In the toner of the present invention, the content of these wax components is 0.1 to 20 parts by mass, preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the binder resin.
[0062]
If it is less than 0.1 part by mass, the effect of wax does not appear, and the effect on tailing, low-temperature fixability and cold offset resistance is small. On the other hand, when the amount exceeds 20 parts by mass, it becomes difficult to uniformly disperse the wax component in the toner, which affects the chargeability, increases the cohesiveness of the toner, deteriorates the developability, and further deteriorates. Fog due to electrification also increases.
[0063]
The resin component in the toner composition of the present invention has a GPC chromatogram measured by THF-soluble matter having a molecular weight of 3 × 10.^Three~ 3x10^Four(More preferably, 5 × 10^Three~ 2x10^Four) Region having a main peak and a molecular weight of 1 × 10^Five~ 3x10⁶(More preferably, 5 × 10^Five~ 1x10⁶) Having a sub-peak or shoulder is preferable in an electromagnetic induction type fixing device because it does not deteriorate cold offset resistance and low-temperature fixing property and hardly causes tailing.
[0064]
The molecular weight of the main peak is 3 × 10^ThreeIf it is smaller, the wax component tends to plasticize the resin and hardly dissolves on the toner surface, so that cold offset resistance and tailing are likely to deteriorate. The molecular weight of the main peak is 3 × 10^FourIf it is larger, when the toner is heated at the time of fixing, the melted wax is less likely to exert an effect of connecting the toner particles or between the toner particles and the recording material. Cold offset property tends to deteriorate.
[0065]
The molecular weight of the sub-peak or shoulder is 1 × 10^FiveIf it is smaller, the elasticity of the resin becomes smaller. Therefore, even if the wax melts on the toner surface, it is difficult to obtain the effect of releasing the wax from the rotating heating member, and cold offset resistance and tailing are likely to deteriorate. The molecular weight of the sub-peak or shoulder is 3 × 10⁶If it is larger, the molecular weight of the main peak is 3 × 10^FourFor the same reason as the larger case, the low-temperature fixability and the cold offset resistance in tailing and halftone images are likely to deteriorate.
[0066]
In the present invention, the molecular weight distribution of the resin composition is measured under the following conditions by GPC (gel permeation chromatography).
[0067]
<GPC measurement conditions of resin composition>
Apparatus: GPC-150C (manufactured by Waters)
Column: 7 columns of KF801-7 (manufactured by Shodex)
Temperature: 40 ° C
Solvent: THF (tetrahydrofuran)
Flow rate: 1.0 ml / min
Sample: 0.1 ml of a sample having a concentration of 0.05 to 0.6% by mass is injected.
[0068]
The binder resin used in the present invention preferably has an acid value of 0.5 to 100 (preferably 1 to 50, more preferably 1 to 30) mgKOH / g. By having an acid value within this range, the difference in polarity between the binder resin and the wax increases, and when the toner is heated during fixing, the wax component is easily dissolved on the surface of the toner. This enhances the effect of connecting the particles to the recording material, and is effective for tailing, low-temperature fixability, and cold offset resistance.
[0069]
When the acid value is less than 0.5 mg KOH / g, the wax component is difficult to dissolve on the toner surface, and depending on the wax, the effect on tailing, low-temperature fixability, and cold offset resistance may be reduced. When the acid value is greater than 100 mgKOH / g, the chargeability of the toner becomes difficult to stabilize, and the developability in a high humidity environment and the fogging in a low humidity environment may deteriorate.
[0070]
In the present invention, the acid value (JIS acid value) of the binder resin is determined by the following method.
[0071]
<Measurement of acid value (JIS acid value)>
1) Weigh precisely 0.1 to 2.0 g of the pulverized product of the sample, and let its weight be W (g).
2) Put a sample in a 20 cc Erlenmeyer flask and dissolve by adding 10 cc of a mixed solution of toluene / ethanol (2: 1).
3) Add a few drops of phenolphthalein alcohol solution as an indicator.
4) Titrate the solution in the flask with a 0.1 mol / l alcohol solution of KOH using a burette. The amount of KOH solution used at this time is S (ml). At the same time, a blank test is performed, and the amount of the KOH solution at this time is B (ml). The acid value is calculated by the following formula.
[0072]
Acid value = (SB) × f × 5.61 / W (f: factor of KOH solution)
[0073]
Examples of the monomer for adjusting the acid value of the binder resin include acrylic acid such as acrylic acid, methacrylic acid, α-ethylacrylic acid, and crotonic acid, and α- or β-alkyl derivatives thereof, fumaric acid, maleic acid, citracone. There are unsaturated dicarboxylic acids such as acids and their monoester derivatives or maleic anhydride, and the desired polymer can be prepared by copolymerizing such monomers alone or in combination with other monomers. . Among these, it is particularly preferable to use a monoester derivative of an unsaturated dicarboxylic acid in order to control the acid value.
[0074]
More specifically, for example, monomethyl maleate, monoethyl maleate, monobutyl maleate, monooctyl maleate, monoallyl maleate, monophenyl maleate, monomethyl fumarate, monoethyl fumarate, monobutyl fumarate, monophenyl fumarate Monoesters of α, β-unsaturated dicarboxylic acids such as: monobutyl n-butenyl succinate, monomethyl n-octenyl succinate, monoethyl n-butenylmalonate, monomethyl n-dodecenyl glutarate, monobutyl n-butenyl adipate Monoesters of alkenyl dicarboxylic acids such as, and the like; monoesters of aromatic dicarboxylic acids such as phthalic acid monomethyl ester, phthalic acid monoethyl ester, phthalic acid monobutyl ester, and the like.
[0075]
What is necessary is just to add 0.1-30 mass% of the above carboxyl group containing monomers with respect to all the monomers which comprise binder resin.
[0076]
The reason why the monoester monomer of dicarboxylic acid as described above is selected is that suspension polymerization is not suitable for use in the form of an acid monomer having high solubility in an aqueous suspension, and has low solubility. This is because it is preferably used in the form of an ester.
[0077]
The binder resin used in the present invention has a THF-insoluble content of preferably 0 to 10% by mass, more preferably 0 to 5% by mass, and more preferably 0 to 3% by mass based on the resin composition.
[0078]
The THF-insoluble matter in the present invention refers to the mass proportion of the polymer component (substantially crosslinked polymer) insoluble in the THF solvent in the resin composition in the toner. It can be used as a parameter indicating the degree of crosslinking. The THF-insoluble content is defined as a value measured as follows.
[0079]
A toner sample of 0.5 to 1.0 g is weighed (w1 g), put into a cylindrical filter paper (for example, No. 86R manufactured by Toyo Roshi), passed through a Soxhlet extractor, extracted with 200 ml of THF as a solvent, and extracted for 10 hours. After evaporating the soluble component, vacuum drying is performed at 100 ° C. for several hours, and the amount of the THF-soluble resin component is weighed (w2 g). The mass of components other than the resin component such as a magnetic substance or pigment in the toner is (w3 g). The THF-insoluble content can be obtained from the following formula.
THF insoluble matter (%) = [(w1- (w3 + w2)) / (w1-w3)] × 100
[0080]
If the THF-insoluble content exceeds 10% by mass, the elasticity of the binder resin becomes too high, and the effect of holding individual toner particles tends to be hindered, making it difficult to obtain an effect on tailing, cold offset resistance, and low-temperature fixability. .
[0081]
The binder resin according to the present invention has a glass transition temperature (Tg) of 50 to 70 ° C, preferably 55 to 65 ° C, from the viewpoint of storage stability. When Tg is lower than 50 ° C., the toner is likely to deteriorate in a high temperature atmosphere, and high temperature offset is likely to occur during fixing. On the other hand, when Tg exceeds 70 ° C., the low-temperature fixability tends to decrease.
[0082]
As a method for producing the binder resin according to the present invention, a solution blend method in which a high molecular weight polymer and a low molecular weight polymer are synthesized separately by a solution polymerization method and then mixed in a solution state and then desolvated, Examples thereof include a dry blend method in which melt kneading is performed using an extruder or the like. However, the dry blend method is problematic in terms of uniform dispersion and compatibility, and therefore the solution blend method is most suitable. In addition, as a method for introducing a predetermined acid value into the low molecular weight polymer, solution polymerization in which the acid value can be easily set as compared with the aqueous polymerization method is preferable.
[0083]
Examples of polymerization methods that can be used in the present invention as a method for synthesizing a high molecular weight polymer include solution polymerization, emulsion polymerization, and suspension polymerization.
[0084]
Among them, the emulsion polymerization method is a method in which a monomer (monomer) almost insoluble in water is dispersed as small particles in an aqueous phase with an emulsifier, and polymerization is performed using a water-soluble polymerization initiator. In this method, the heat of reaction can be easily adjusted, and since the phase in which the polymerization is carried out (the oil phase consisting of the polymer and the monomer) and the aqueous phase are different, the termination reaction rate is low, resulting in a high polymerization concentration. A product having a high degree of polymerization is obtained. Furthermore, since the polymerization process is relatively simple and the polymerization product is fine particles, the toner can be easily mixed with colorants, charge control agents and other additives in the production of the toner. There is an advantage as a method for producing a binder resin.
[0085]
However, due to the added emulsifier, the polymer tends to be impure, and an operation such as salting out is necessary to take out the polymer. Suspension polymerization is convenient to avoid this inconvenience.
[0086]
In suspension polymerization, it is good to carry out by 100 mass parts or less (preferably 10-90 mass parts) of monomers with respect to 100 mass parts of aqueous solvents. Examples of the dispersant that can be used include polyvinyl alcohol, partially saponified polyvinyl alcohol, calcium phosphate, and the like, and generally 0.05 to 1 part by mass with respect to 100 parts by mass of the aqueous solvent. The polymerization temperature is suitably 50 to 95 ° C., but is appropriately selected depending on the initiator used and the target polymer.
[0087]
In order to achieve the object of the present invention, the high molecular weight polymer used for the preparation of the binder resin is produced by using a polyfunctional polymerization initiator alone or in combination with a monofunctional polymerization initiator as exemplified below. It is preferable.
[0088]
Specific examples of the polyfunctional polymerization initiator having a polyfunctional structure include 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,3-bis- (t-butylperoxy Isopropyl) benzene, 2,5-dimethyl-2,5- (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di- (t-butylperoxy) hexyne-3, tris- (t -Butylperoxy) triazine, 1,1-di-t-butylperoxycyclohexane, 2,2-di-t-butylperoxybutane, 4,4-di-t-butylperoxyvaleric acid-n- Butyl ester, di-t-butylperoxyhexahydroterephthalate, di-t-butylperoxyazelate, di-t-butylperoxytrimethyladipate, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) has a polymerization initiation function such as two or more peroxide groups in one molecule such as propane, 2,2-t-butylperoxyoctane and various polymer oxides. A polyfunctional polymerization initiator having a functional group; and diallyl peroxydicarbonate, t-butylperoxymaleic acid, t-butylperoxyallylcarbonate, t-butylperoxyisopropyl fumarate, Examples thereof include polyfunctional polymerization initiators having both a functional group having a polymerization initiation function such as an oxide group and a polymerizable unsaturated group.
[0089]
Of these, more preferred are 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-t-butylperoxycyclohexane, di-t-butylperoxy. Hexahydroterephthalate, di-t-butylperoxyazelate and 2,2-bis- (4,4-di-t-butylperoxycyclohexane) propane, and t-butylperoxyallyl carbonate.
[0090]
These polyfunctional polymerization initiators are preferably used in combination with a monofunctional polymerization initiator in order to satisfy various performances required as a binder for toner. In particular, it is preferable to use in combination with a polymerization initiator having a half-life of 10 hours lower than the decomposition temperature for obtaining a half-life of 10 hours of the polyfunctional polymerization initiator.
[0091]
Specifically, benzoyl peroxide, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4-di (t-butylperoxy) valerate, dichroic Organic peroxides such as milperoxide, α, α'-bis (t-butylperoxydiisopropyl) benzene, t-butylperoxycumene, di-t-butylperoxide; azobisisobutyronitrile, diazoaminoazobenzene And azo and diazo compounds.
[0092]
These monofunctional polymerization initiators may be added to the monomer at the same time as the polyfunctional polymerization initiator, but in order to keep the efficiency of the polyfunctional polymerization initiator appropriate, in the polymerization step, It is preferably added after the half-life indicated by the polyfunctional polymerization initiator has elapsed.
[0093]
These initiators are preferably used in an amount of 0.05 to 2 parts by mass with respect to 100 parts by mass of the monomer from the viewpoint of efficiency.
[0094]
In order to satisfactorily achieve the object of the present invention, the high molecular weight polymer is preferably crosslinked with a crosslinkable monomer as exemplified below.
[0095]
As the crosslinkable monomer, a monomer having two or more polymerizable double bonds is mainly used. Aromatic divinyl compounds (eg, divinylbenzene, divinylnaphthalene, etc.); diacrylate compounds linked by alkyl chains (eg, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate) , 1,5-pentanediol acrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and acrylates of the above compounds replaced with methacrylate); di-linked by an alkyl chain containing an ether bond Acrylate compounds (eg, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate, and acrylates of the above compounds replaced with methacrylate); diacrylate compounds linked by a chain containing an aromatic group and an ether bond (eg, polyoxyethylene (2 ) -2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4-hydroxyphenyl) propane diacrylate, and acrylates of the above compounds are replaced with methacrylate. Polyester type diacrylate compounds (for example, trade name MANDA (Nippon Kayaku)). Polyfunctional crosslinkers include pentaerythritol acrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and acrylates of the above compounds to methacrylate. Alternatives: triallyl cyanurate, triallyl trimellitate and the like.
[0096]
These crosslinking agents are preferably used in an amount of 1 part by mass or less, preferably 0.001 to 0.05 parts by mass with respect to 100 parts by mass of other monomer components.
[0097]
Among these crosslinkable monomers, aromatic divinyl compounds (particularly divinylbenzene), divalent groups connected by a chain containing an aromatic group and an ether bond are preferably used from the viewpoint of toner fixing properties and offset resistance. Examples include acrylate compounds.
[0098]
A known method can be used as a method for synthesizing the low molecular weight component. However, in the bulk polymerization method, a polymer having a low molecular weight can be obtained by polymerizing at a high temperature to increase the termination reaction rate, but there is a problem that the reaction is difficult to control. In that respect, in the solution polymerization method, a low molecular weight polymer can be easily obtained under mild conditions by utilizing the difference in radical chain transfer caused by the solvent and adjusting the initiator amount and reaction temperature. It is particularly preferable for obtaining a low molecular weight substance in the resin composition. In particular, a solution polymerization method under a pressurized condition is also preferable in that the amount of the polymerization initiator used is minimized and the influence of the initiator residue is minimized.
[0099]
Examples of the monomer for obtaining the high molecular weight polymer and the monomer for obtaining the low molecular weight polymer include the following.
[0100]
For example, styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4- Dimethyl styrene, pn-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl Styrene derivatives such as styrene; Ethylene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; Unsaturated polyenes such as butadiene and isoprene; Vinyl halides such as vinyl chloride, vinyl bromide and vinyl fluoride; Acetic acid Vinyl esthetics such as vinyl, vinyl propionate and vinyl benzoate Class: Methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, methacryl Α-methylene aliphatic monocarboxylic acid esters such as dimethylaminoethyl acid, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, Acrylic esters such as dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; vinyl methyl ether, vinyl ethyl ether Ter, vinyl ethers such as vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone; N- such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone. Vinyl compounds; vinyl naphthalenes; and acrylic acid derivatives or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide. These vinyl monomers are used alone or in admixture of two or more monomers.
[0101]
Among these, a combination of monomers that becomes a styrene copolymer or a styrene acrylic copolymer is preferable.
[0102]
Further, in the present invention, in the toner having a weight average particle diameter of 5 to 12 μm and 3 μm or more of the toner, particles having a circularity a = 0.900 or more obtained from the following formula are accumulated based on the number. 90% or more
Circularity a = L₀/ L
(Where L₀Indicates the perimeter of a circle having the same projected area as the particle image, and L indicates the perimeter of the particle image. )
In addition, the relationship between the cut rate Z and the toner weight average diameter X is
Cut rate Z ≦ 5.3 × X
[However, the cut rate Z is expressed by the following formula, where A is the total number of particles and B is the number of measured particles of 3 μm or more.
Z = (1-B / A) × 100]
And the relationship between the number-based cumulative value Y of particles having a circularity of 0.950 or more and the weight average diameter X of the toner is
Number-based cumulative value Y ≧ exp5.51 × X of particles having a circularity of 0.950 or more^-0.645
[However, toner weight average diameter X: 5.0 to 12.0 μm]
Or
In the toner having a weight average particle diameter of 5 to 12 μm and particles of 3 μm or more of the toner, 90% or more of particles having a circularity a = 0.900 or more obtained from the following formula are accumulated on a number basis,
Circularity a = L₀/ L
(Where L₀Indicates the perimeter of a circle having the same projected area as the particle image, and L indicates the perimeter of the particle image. )
In addition, the relationship between the cut rate Z and the toner weight average diameter X is
Cut rate Z> 5.3 × X
And the relationship between the number-based cumulative value Y of particles having a circularity of 0.950 or more and the toner weight average diameter X is
Number-based cumulative value Y ≧ exp5.37 × X of particles having a circularity of 0.950 or more^-0.545
[However, toner weight average diameter X: 5.0 to 12.0 μm]
Is satisfied, it exhibits excellent performance with respect to tailing, and further, cold offset resistance and low-temperature fixability in a halftone image are also improved.
[0103]
The toner shape affects various characteristics of the toner, but the circularity of toner particles having an equivalent circle diameter of 3 μm or more is controlled according to the amount of fine particles having an equivalent circle diameter of less than 3 μm, such as toner fine powder and external additives. Thus, the electromagnetic induction type fixing device used in the present invention can exhibit excellent performance.
[0104]
By controlling the circularity of toner particles having an equivalent circle diameter of 3 μm or more, the toner is densely packed on the recording material (even if the toner mass developed per recording material unit area is the same, Therefore, even if a water vapor flow is suddenly generated at the fixing nip portion, the toner is hardly blown off, the image is hardly disturbed, and tailing is suppressed. Further, in such a state where the toner is tightly packed on the recording material, since the toner particles are in close contact with each other when the toner is heated at the time of fixing, the wax that keeps the toner particles and the toner particles and the recording material together. Therefore, even if the amount of toner is small, such as halftone, it is excellent in low-temperature fixability, and cold offset is less likely to occur.
[0105]
The fine powder having an equivalent circle diameter of less than 3 μm contained in the toner tends to hinder these effects. Therefore, when the toner contains many toner particles having an equivalent circle diameter of less than 3 μm, or an external additive having an equivalent circle diameter of less than 3 μm is used. When a large amount is added, it is difficult to obtain desired performance unless the circularity of toner particles having an equivalent circle diameter of 3 μm or more is increased as compared with the case where the amount is not so large.
[0106]
Cut rate Z is
Cut rate Z ≦ 5.3 × X
And
Number based cumulative value Y <exp5.51 × X of particles having a circularity of 0.950 or more^-0.645
Or
Cut rate Z> 5.3 × X
And
Number based cumulative value Y <exp5.37 × X of particles having a circularity of 0.950 or more^-0.545
In this case, since the circularity of toner particles having an equivalent circle diameter of 3 μm or more is not sufficiently high, it is difficult to obtain an effect on cold offset resistance and low-temperature fixability in tailing and halftone images.
[0107]
The circularity used in the present invention is an index of the degree of unevenness of the toner particles, and indicates 1.00 when the toner is a perfect sphere. The more complicated the surface shape, the smaller the circularity.
[0108]
A specific method for measuring the circularity of the toner is shown below. In 100 to 150 ml of water from which impurities in the container have been removed in advance, 0.1 to 0.5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant, and about 0.1 to 0.5 g of a measurement sample is further added. . The suspension in which the sample is dispersed is irradiated with ultrasonic waves (50 kHz, 120 W) for 1 to 3 minutes, the dispersion concentration is set to 1.2 to 2 million pieces / μl, and the flow type particle image measurement apparatus is used. The circularity distribution of particles having an equivalent circle diameter of 0.60 μm or more and less than 159.21 μm is measured. In addition, by setting the dispersion concentration to 1.2 to 2 million pieces / μl, it is possible to maintain a particle concentration that can maintain the accuracy of the apparatus even when the cutting rate increases.
[0109]
The outline of the measurement is described in the catalog (June 1995 edition) of FPIA-1000 published by Toa Medical Electronics Co., Ltd., the operation manual of the measuring apparatus, and JP-A-8-136439. It is.
[0110]
The sample dispersion is passed through a flow path (expanded along the flow direction) of a flat and flat flow cell (thickness: about 200 μm). The strobe and the CCD camera are mounted on the flow cell so as to be opposite to each other so as to form an optical path that passes through the thickness of the flow cell. While the sample dispersion is flowing, strobe light is irradiated at 1/30 second intervals to obtain an image of the particles flowing through the flow cell, so that each particle has a certain range parallel to the flow cell. Photographed as a two-dimensional image. From the area of the two-dimensional image of each particle, the diameter of a circle having the same area is calculated as the equivalent circle diameter. The circularity of each particle is calculated from the projected area of the two-dimensional image of each particle and the perimeter of the projected image using the above circularity calculation formula.
[0111]
In addition, “FPIA-1000”, which is a measuring apparatus used in the present invention, calculates the circularity of each particle, and then calculates the average circularity and the circularity standard deviation. A degree of 0.4 to 1.0 is divided into 61 classes, and a calculation method is used in which the average circularity and circularity standard deviation are calculated using the center value and frequency of the division points. However, the error of the average circularity and the circularity standard deviation calculated by the calculation formula using each value of the average circularity and the circularity standard deviation calculated by this calculation method and the circularity of each particle described above is In the present invention, the circularity of each particle described above is directly set for the reason of handling data such as shortening the calculation time and simplifying the calculation formula. The circularity standard deviation SD can also be used as one measure of the variation of particles having such circularity, which is partially changed by using the concept of the calculation formula to be used. In the present invention, there is no problem if the circularity standard deviation SD is 0.030 to 0.045.
[0112]
When a toner having a specific circularity is produced, the weight average diameter is preferably 5 to 12 μm, more preferably particles having a weight average diameter of 5 to 10 μm and a particle diameter of 4.0 μm or less. The toner may be 40% by number or less, and particles having a particle size of 10.1 μm or more being 25% by volume or less.
[0113]
A toner having a weight average diameter larger than 12 μm is not developed in a state where toner particles having a circle equivalent diameter of 3 μm or more have a high degree of circularity and are densely packed on the recording material even if the circularity of the toner particles is increased. Since there are many voids, it is difficult to obtain effects in tailing, cold offset resistance, and low-temperature fixability.
[0114]
When the weight average diameter is smaller than 5 μm, the average equivalent circle diameter of the toner becomes small, and the ratio of toner particles having an equivalent circle diameter of 3 μm or less becomes too large. Even if it is increased, it is difficult to obtain an effect on tailing, cold offset resistance, and low-temperature fixability.
[0115]
When the number of particles having a particle size of 4.0 μm or less exceeds 40% by number, even if the circularity of toner particles having an equivalent circle diameter of 3 μm or more is increased, the effect of inhibiting the effect is strengthened. It is difficult to obtain an effect on the property and low temperature fixability, which is not preferable.
[0116]
A case where particles having a particle size of 10.1 μm or more exceed 25% by volume is not preferable for the same reason as when the weight average diameter is larger than 12 μm.
[0117]
The toner particle size distribution was measured by the following method.
[0118]
The particle size distribution can be measured by various methods. In the present invention, the particle size distribution was performed using a multisizer of a Coulter counter.
[0119]
As a measuring device, a multisizer type II or type IIE (manufactured by Coulter Co.) of a Coulter counter is used, and an interface (manufactured by Nikkiki) that outputs number distribution and volume distribution is connected to a general personal computer, A 1% NaCl aqueous solution is prepared using special grade or first grade sodium chloride. As a measuring method, 0.1 to 5 ml of a surfactant (preferably 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 a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and measured using a Coulter counter Multisizer II type with a 100 μm aperture. The volume and number of toners are measured to calculate a volume distribution and a number distribution, and a weight-based weight average diameter obtained from the volume distribution is obtained.
[0120]
The toner of the present invention can be used as a two-component developer in combination with a carrier, and any conventionally known carrier can be used for the two-component development method. In this case, particles having an average particle diameter of 20 to 300 μm, such as surface oxidized or unoxidized metals such as iron, nickel, cobalt, manganese, chromium, rare earth, and alloys or oxides thereof are used.
[0121]
Further, those obtained by adhering or coating a substance such as a styrene resin, an acrylic resin, a silicone resin, a fluorine resin, or a polyester resin on the surface of the carrier particles are preferably used.
[0122]
The toner of the present invention may further contain a magnetic material and be used as a magnetic toner. In this case, the magnetic material can also serve as a colorant. In the present invention, the magnetic material contained in the magnetic toner includes iron oxides such as magnetite, maghemite, and ferrite; metals such as iron, cobalt, and nickel, or these metals aluminum, cobalt, copper, lead, magnesium, tin And alloys of metals such as zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, and mixtures thereof.
[0123]
These ferromagnetic materials have an average particle diameter of 2 μm or less, preferably 0.1 to 0.5 μm. The amount to be contained in the toner is about 20 to 200 parts by mass, particularly preferably 40 to 150 parts by mass with respect to 100 parts by mass of the resin component.
[0124]
The colorant that can be used in the toner of the present invention includes any appropriate pigment or dye. Examples of the toner colorant include carbon black, aniline black, acetylene black, naphthol yellow, Hansa yellow, rhodamine lake, alizarin lake, Bengala, phthalocyanine blue, and indanthrene blue as pigments. These are used in an amount necessary and sufficient to maintain the optical density of the fixed image, and an addition amount of 0.1 to 20 parts by mass, preferably 0.2 to 10 parts by mass is preferable with respect to 100 parts by mass of the resin. For the same purpose, a dye is further used. For example, there are azo dyes, anthraquinone dyes, xanthene dyes, and methine dyes, and the addition amount is 0.1 to 20 parts by weight, preferably 0.3 to 10 parts by weight, based on 100 parts by weight of the resin.
[0125]
The toner of the present invention preferably contains a charge control agent. The following substances are used for controlling the toner to be negatively charged.
[0126]
For example, organometallic complexes and chelate compounds are effective, and there are monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid 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.
[0127]
Further, an azo metal complex represented by the following general formula (1) is preferable.
[0128]
[Chemical 1]

[Wherein M represents a coordination center metal, and examples thereof include Sc, Ti, V, Cr, Co, Ni, Mn, and Fe. Ar is an aryl group, and examples thereof include a phenyl group and a naphthyl group, which may have a substituent. Examples of the substituent in this case include a nitro group, a halogen group, a carboxyl group, an anilide group, an alkyl group having 1 to 18 carbon atoms, and an alkoxy group. X, X ', Y, and Y' are -O-, -CO-, -NH-, and -NR- (R is an alkyl group having 1 to 4 carbon atoms). A⁺Represents hydrogen, sodium, potassium, ammonium, aliphatic ammonium or none. ]
[0129]
In particular, the central metal is preferably Fe or Cr, the substituent is preferably a halogen, an alkyl group, or an anilide group, and the counter ion is preferably hydrogen, alkali metal ammonium, or aliphatic ammonium. A mixture of complex salts having different counter ions is also preferably used.
[0130]
Alternatively, the basic organic acid metal complex represented by the following general formula (2) also gives negative chargeability and can be used in the present invention.
[0131]
[Chemical 2]

[0132]
In particular, the central metal is preferably Fe, Cr, Si, Zn, or Al, the substituent is preferably an alkyl group, anilide group, aryl group, or halogen, and the counter ion is preferably hydrogen, ammonium, or aliphatic ammonium.
[0133]
Among them, the azo metal complex represented by the formula (1) is more preferable, and the azo iron complex represented by the following formula (3) is most preferable.
[0134]
[Chemical Formula 3]

[0135]
Next, specific examples of the complex are shown.
[0136]
[Formula 4]

[0137]
[Chemical formula 5]

[0138]
The following substances are used for controlling the toner to be positively charged. Modified products with nigrosine and fatty acid metal salts, etc .; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and analogs such as oniums such as phosphonium salts Salts and their lake pigments, triphenylmethane dyes and their lake pigments (the rake agents include phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, Russian compounds, metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate, dioctyltin borate, dicyclohexyl Diorgano tin borate such as Suzuboreto; guanidine compounds, imidazole compounds. These can be used alone or in combination of two or more. Among these, triphenylmethane compounds and quaternary ammonium salts whose counter ions are not halogen are preferably used. Further, the general formula (4)
[0139]
[Chemical 6]

[In the formula, R₁Is H or CH_ThreeR₂And R_ThreeRepresents a substituted or unsubstituted alkyl group (preferably C1-C4)]
A homopolymer of a monomer represented by the following: A copolymer with a polymerizable monomer such as styrene, acrylic acid ester or methacrylic acid ester described above can be used as a positive charge control agent. In this case, these charge control agents also have an action as a binder resin (all or a part thereof).
[0140]
In particular, a compound represented by the following general formula (5) is preferable in the constitution of the present invention.
[0141]
[Chemical 7]

[Wherein R₁, R₂, R_Three, R_Four, R_FiveAnd R₆Each represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, which may be the same as or different from each other, and R₇, R₈And R₉Represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, which may be the same or different from each other, and A^-Is an anion selected from sulfate ion, nitrate ion, borate ion, phosphate ion, hydroxide ion, organic sulfate ion, organic sulfonate ion, organic phosphate ion, carboxylate ion, organic borate ion or tetrafluoroborate Indicates. ]
[0142]
As a method for adding the charge control agent to the toner, there are a method of adding the charge control agent inside the toner and a method of adding the charge control agent externally. The amount of use of these charge control agents is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the binder resin.
[0143]
In the toner of the present invention, it is preferable to add silica fine powder in order to improve charging stability, developability, fluidity and durability.
[0144]
The silica fine powder used in the present invention has a specific surface area of 20 m by nitrogen adsorption measured by the BET method.²/ G or more (especially 30 to 400 m²/ G) gives good results. The silica fine powder is used in an amount of 0.01 to 8 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the toner.
[0145]
In addition, the silica fine powder may be used for silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane coupling agents, silylating agents, and other organic substances for the purpose of hydrophobization and chargeability control, as necessary. It is also preferable to treat with a treating agent such as a silicon compound or with various treating agents.
[0146]
Moreover, it is also preferable to add the following inorganic powder in order to improve developability and durability. Magnesium, zinc, aluminum, cerium, cobalt, iron, zirconium, chromium, manganese, strontium, tin, antimony and other metal oxides, calcium titanate, magnesium titanate, strontium titanate and other complex metal oxides; calcium carbonate, Metal salts such as magnesium carbonate and aluminum carbonate; clay minerals such as kaolin; phosphate compounds such as apatite; silicon compounds such as silicon carbide and silicon nitride; and carbon powders such as carbon black and graphite. Of these, zinc oxide, aluminum oxide, cobalt oxide, manganese dioxide, strontium titanate, magnesium titanate and the like are preferable.
[0147]
Further, the following lubricant powder can be added. Fluorine resins such as Teflon and polyvinylidene fluoride; Fluorine compounds such as carbon fluoride; Fatty acid metal salts such as zinc stearate; Fatty acid derivatives such as fatty acids and fatty acid esters; Molybdenum sulfide, amino acids and amino acid derivatives.
[0148]
As a toner production apparatus, for example, as a mixer, a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.); a super mixer (manufactured by Kawata Corporation); a ribocorn (manufactured by Okawara Seisakusho Co., Ltd.); a nauter mixer, a turbulizer, a cyclomix (Hosokawa Micron Corporation) Spiral pin mixer (manufactured by Taiheiyo Kiko Co., Ltd.); Ladige mixer (manufactured by Matsubo Co., Ltd.), and KRC kneader (manufactured by Kurimoto Iron Works Co.); Bus co-kneader (manufactured by Buss) ); TEM type extruder (manufactured by Toshiba Machine Co., Ltd.); TEX twin-screw kneader (manufactured by Nippon Steel Works); PCM kneader (manufactured by Ikekai Iron Works Co., Ltd.); three roll mill, mixing roll mill, kneader (manufactured by Inoue Seisakusho Co., Ltd.) ); Needex (Mitsui Mining Co., Ltd.); MS pressure kneader, Nider Ruder (Moriyama Seisakusho); Banbury Miki -(Made by Kobe Steel Co., Ltd.), and the pulverizers include counter jet mill, micron jet, inomizer (manufactured by Hosokawa Micron); IDS type mill, PJM jet pulverizer (manufactured by Nippon Pneumatic Industrial Co., Ltd.); cross jet Mill (manufactured by Kurimoto Iron Works); Urmax (manufactured by Nisso Engineering Co., Ltd.); SK Jet O Mill (manufactured by Seishin Enterprise Co., Ltd.); Kryptron (manufactured by Kawasaki Heavy Industries, Ltd.); Classifiers include: Classy, Micron Classifier, Spedic Classifier (manufactured by Seishin Enterprise); Turbo Classifier (manufactured by Nisshin Engineering); Micron Separator, Turboplex (ATP), TSP Separator (Hosokawa Micron) Elbow Jet (Sun) Mining Co., Ltd.), Dispersion Separator (manufactured by Nippon Pneumatic Industrial Co., Ltd.); YM Micro Cut (manufactured by Yaskawa Shoji Co., Ltd.), and Ultrasonic (Sakae) used as a sieving device for sieving coarse particles Resona sieve, gyro shifter (Tokuju Kogakusha); Vibrasonic system (Dalton); Soniclean (Shinto Kogyo); Turbo screener (Turbo Kogyo); Micro shifter (Ogino Sangyo) A circular vibration sieve, etc.
[0149]
In the present invention, it is preferable to control the circularity of the toner without increasing the production process, and it is particularly preferable to control the circularity of the toner in the pulverization process.
[0150]
For the pulverization of the coarsely pulverized toner mainly composed of the binder resin, a jet airflow pulverizer using a jet airflow as shown in FIG. 7, particularly a collision airflow pulverizer can be used.
[0151]
A collision-type airflow crusher using a high-pressure gas such as a jet stream transports the powder raw material by a jet stream and injects it from the exit of the acceleration tube, and the powder material is provided facing the opening surface of the exit of the acceleration tube. The powder raw material is crushed by the impact force of the collision member.
[0152]
However, the collision type airflow pulverizer is configured such that the powder raw material is jetted together with the high-pressure gas, collides with the collision surface of the collision member, and is pulverized by the impact, so the pulverized toner is irregular and angular. It is easy to become a thing. Therefore, in order to pulverize using a collision-type airflow pulverizer and control the circularity of the toner at the same time, the impact force when the powder raw material collides with the collision member is reduced, and the residence time in the pulverizer is increased. For example, it is necessary to round the convex portion of the pulverized product. This is not a preferable method from the viewpoint of toner productivity because the pulverization amount decreases.
[0153]
Hereinafter, preferred embodiments of a toner production method of the present invention will be described in detail with reference to the accompanying drawings.
[0154]
FIG. 1 is an example of a flowchart showing an outline of a preferable method for producing the toner of the present invention. As shown in the flowchart, the production method of the present invention does not require a classification step before the pulverization process, and is characterized in that the pulverization step and the classification step are performed in one pass.
[0155]
The toner production method of the present invention was obtained by melt-kneading a mixture containing a binder resin, a colorant, wax and the like, cooling the obtained kneaded product, and then pulverizing the cooled product by a pulverizing means. A coarsely pulverized product is used as a powder raw material.
[0156]
First, a rotor composed of a rotating body having at least a predetermined amount of pulverized raw material attached to a central rotating shaft, and a stator disposed around the rotor with a predetermined distance from the rotor surface. The annular space formed by holding the gap is introduced into a mechanical pulverizer configured to be in an airtight state, and the rotor of the mechanical pulverizer is rotated at high speed Finely pulverize the material to be crushed. Next, the finely pulverized pulverized raw material is introduced into a classification step and classified to obtain a classified product as a toner raw material including particles having a preferable particle size. At this time, in the classification step, a multi-split airflow classifier having at least a coarse powder region, a medium powder region, and a fine powder region is preferably used. For example, when a three-part airflow classifier is used, the powder raw material is classified into at least three types of fine powder, medium powder, and coarse powder. In the classification process using such a classifier, the coarse powder composed of particles larger than the preferred particle size and the fine powder composed of particles smaller than the preferred particle size are removed, and the intermediate powder is used as a toner product as it is. Or mixed with an external additive such as hydrophobic colloidal silica and then used as a toner.
[0157]
The fine powder composed of particles having a particle size less than the preferred particle size classified in the classification step is generally supplied to a melt-kneading step for producing a powder raw material composed of a toner material introduced into the pulverization step. Can be reused or discarded. Similarly, the ultra fine powder slightly smaller in the pulverization process and classification process than the fine powder is supplied to the melt-kneading process and reused or discarded.
[0158]
FIG. 2 shows an example of an apparatus system to which the toner manufacturing method of the present invention is applied, and the present invention will be described more specifically based on this. Colored resin particle powders containing a binder resin, a colorant, a wax, and the like are used for the powder material that is a toner material to be introduced into the apparatus system. A mixture composed of a colorant, wax and the like is melt-kneaded, the obtained kneaded product is cooled, and the cooled product is coarsely pulverized by a pulverizing means.
[0159]
In this apparatus system, a pulverized raw material serving as a toner powder raw material is first introduced into a mechanical pulverizer 301 serving as a pulverizing unit via a first fixed amount feeder 315. The introduced pulverized raw material is instantaneously pulverized by the mechanical pulverizer 301 and is introduced into the second fixed amount feeder 2 through the collecting cyclone 229. Subsequently, it is supplied into the multi-division airflow classifier 1 which is a classification means through the vibration feeder 3 and further through the raw material supply nozzle 16.
[0160]
Further, in this apparatus system, a predetermined amount introduced from the first fixed amount feeder 315 to the mechanical pulverizer 301 as the pulverizing means, and the multi-division airflow classifier 1 as the classification means from the second constant amount feeder 2 When the predetermined amount introduced from the first fixed amount feeder 315 to the mechanical crusher 301 is 1, the relationship from the introduced predetermined amount is introduced from the second constant amount feeder 2 to the multi-split airflow classifier 1 The predetermined amount is preferably 0.7 to 1.7, more preferably 0.7 to 1.5, and still more preferably 1.0 to 1.2 from the viewpoint of toner productivity and production efficiency. .
[0161]
In general, the airflow classifier of the present invention is used by connecting devices to each other by a communication means such as a pipe, and being incorporated in an apparatus system. A preferred example of such a device system is shown in FIG. The integrated apparatus system shown in FIG. 2 communicates the multi-division classifying apparatus 1 (classifying apparatus shown in FIG. 6), the quantitative feeder 2, the vibration feeder 3, the collecting cyclone 4, the collecting cyclone 5, and the collecting cyclone 6. It is connected by.
[0162]
In this apparatus system, the powder is fed to the fixed quantity feeder 2 by an appropriate means, and then introduced into the three-division classifier 1 through the vibration feeder 3 by the raw material supply nozzle 16. At the time of introduction, the powder is introduced into the three-class classifier 1 at a flow rate of 10 to 350 m / s. Since the size of the classification chamber of the three-division classifier 1 is usually [10 to 50 cm] × [10 to 50 cm], the powder is instantaneously divided into three or more types of particles in 0.1 to 0.01 seconds or less. Can be classified. Then, the three-class classifier 1 classifies the particles into large particles (coarse particles), intermediate particles, and small particles. Thereafter, the large particles are sent to the collecting cyclone 6 through the discharge conduit 11 a and returned to the mechanical crusher 301. The intermediate particles are discharged out of the system through the discharge conduit 12a, collected by the collecting cyclone 5, and collected as toner. The small particles are discharged out of the system through the discharge conduit 13a and collected by the collecting cyclone 4 and supplied to the melt-kneading process for producing the powder raw material made of the toner material for reuse or disposal. Is done. The collecting cyclones 4, 5, 6 can also serve as a suction pressure reducing means for sucking and introducing the powder into the classification chamber via the raw material supply nozzle 16. In addition, it is preferable that the large particles classified at this time are reintroduced into the first constant supply machine 315, mixed into the powder raw material, and pulverized again by the mechanical pulverizer 301.
[0163]
Further, the reintroduction amount of large particles (coarse particles) reintroduced from the multi-split airflow classifier 1 into the mechanical pulverizer 301 is based on the mass of the finely pulverized product supplied from the second fixed amount supply device 2. From 0 to 10.0% by mass, more preferably from 0 to 5.0% by mass, is preferable for toner production. When the reintroduction amount of large particles (coarse particles) reintroduced from the multi-split air classifier 1 into the mechanical pulverizer 301 exceeds 10.0% by mass, the dust concentration in the mechanical pulverizer 301 increases. In addition, the load on the apparatus itself is increased, and at the same time, the toner is excessively pulverized during pulverization and is liable to cause toner surface deterioration and in-machine fusion, which is not preferable from the viewpoint of toner productivity.
[0164]
In this apparatus system, the particle size of the powder raw material is preferably 95 mass% or more for 18 mesh pass (ASTME-11-61) and 90 mass% or more for 100 meshon (ASTME-11-61). .
[0165]
Further, in this apparatus system, in order to obtain a toner having a sharp particle size distribution with a weight average particle size of 10 μm or less (more preferably 8 μm or less), the weight average particle of the finely pulverized product finely pulverized by a mechanical pulverizer is used. The diameter is 4 to 10 μm, 4.0 μm or less is preferably 70% by number or less, more preferably 65% by number or less, and 10.1 μm or more is 25% by volume or less, and further preferably 20% by volume or less. The classified medium powder has a weight average particle size of 5 to 10 μm, 4.0 μm or less of 40 number%, further 35 number% or less, 10.1 μm or more of 25 volume% or less, It is preferable that it is 20 volume% or less.
[0166]
In the apparatus system to which the toner manufacturing method of the present invention is applied, the first classification step before the pulverization process is not required, and the pulverization step and the classification step can be performed in one pass.
[0167]
A mechanical pulverizer that is preferably used as the pulverizing means used in the toner production method of the present invention will be described. Examples of the mechanical pulverizer include a pulverizer KTM, a kryptron manufactured by Kawasaki Heavy Industries, Ltd., and a turbo mill manufactured by Turbo Kogyo Co., Ltd., and these apparatuses may be used as they are or after being appropriately modified. preferable.
[0168]
In the present invention, among these, using a mechanical pulverizer as shown in FIG. 3, FIG. 4 and FIG. 5 facilitates the pulverization treatment of the powder raw material, thereby improving the efficiency. preferable.
[0169]
The mechanical pulverizer shown in FIGS. 3, 4 and 5 will be described below. 3 shows a schematic cross-sectional view of an example of a mechanical pulverizer used in the present invention, FIG. 4 shows a schematic cross-sectional view taken along the line DD ′ in FIG. 3, and FIG. FIG. 4 shows a perspective view of the rotor 314 shown in FIG. 3. As shown in FIG. 3, the apparatus includes a casing 313, a jacket 316, a distributor 220, and a plurality of grooves on a surface that rotates in a high speed rotating body that is formed in a casing 313 and attached to a central rotating shaft 312. The provided rotor 314, the stator 310 provided with a large number of grooves on the outer periphery of the rotor 314, which are arranged at regular intervals, and the raw material input for introducing the raw material to be treated It comprises a port 311 and a raw material discharge port 302 for discharging the processed powder.
[0170]
The pulverization operation in the mechanical pulverizer configured as described above is performed, for example, as follows. That is, when a predetermined amount of powder raw material is introduced from the powder inlet 311 of the mechanical pulverizer shown in FIG. 3, the particles are introduced into the pulverization chamber and are rotated on the surface rotating at high speed in the pulverization chamber. The impact generated between the rotor 314 provided with a large number of grooves and the stator 310 provided with a large number of grooves on the surface, a large number of ultrahigh-speed vortices generated behind the rotor 314, and the generated It is crushed instantly by high-frequency pressure vibration. Thereafter, the material passes through the material discharge port 302 and is discharged. The air carrying the toner particles passes through the pulverization chamber and is discharged out of the apparatus system through the material discharge port 302, the pipe 219, the collecting cyclone 229, the bag filter 222, and the suction filter 224. Is done. In the present invention, since the powder raw material is pulverized, a desired pulverization treatment can be easily performed without increasing fine powder and coarse powder.
[0171]
Further, when the pulverized raw material is pulverized with a mechanical pulverizer, the cold air generating means 321 blows cold air into the mechanical pulverizer together with the powder raw material, and the mechanical pulverizer body has a structure having a jacket structure 316, By passing cooling water (preferably an antifreeze such as ethylene glycol), the atmospheric temperature in the pulverizer is 0 ° C. or lower, more preferably −5 to −15 ° C., and further preferably −7 to −12 ° C. Is preferable from the viewpoint of toner productivity. By setting the room temperature of the spiral chamber in the pulverizer to 0 ° C. or less, more preferably −5 to −15 ° C., and still more preferably −7 to −12 ° C., the surface modification of the toner due to heat can be suppressed, and the efficiency can be improved. The pulverized raw material can be pulverized. When the atmospheric temperature in the pulverizer exceeds 0 ° C., it is not preferable from the viewpoint of toner productivity because the surface of the toner is easily deteriorated by heat during the pulverization or in-machine fusion. Further, if the atmospheric temperature in the pulverizer is to be operated at a temperature lower than −15 ° C., the refrigerant (alternative chlorofluorocarbon) used in the cold air generating means 321 must be changed to chlorofluorocarbon.
[0172]
Currently, chlorofluorocarbons are being eliminated from the viewpoint of protecting the ozone layer. Use of chlorofluorocarbon as the refrigerant of the cold air generating means 321 is not preferable from the viewpoint of global environmental problems.
[0173]
The cooling water (preferably an antifreeze such as ethylene glycol) is supplied into the jacket from the cooling water supply port 317 and discharged from the cooling water discharge port 318.
[0174]
Further, when the pulverized raw material is pulverized by a mechanical pulverizer, the temperature difference ΔT (T2−T1) between the room temperature T1 of the spiral chamber 212 and the room temperature T2 of the rear chamber 321 is set to 30 to 80 ° C. More preferably, by setting the temperature to 35 to 75 ° C., and more preferably 37 to 72 ° C., the surface deterioration of the toner due to heat can be suppressed, and the pulverized raw material can be efficiently pulverized. When ΔT between the temperature T1 (inlet temperature) and the temperature T2 (outlet temperature) of the mechanical pulverizer is smaller than 30 ° C., there is a possibility that a short pass is caused without being pulverized, which is not preferable from the viewpoint of toner performance. . On the other hand, when the temperature is higher than 80 ° C., the toner may be excessively pulverized at the time of pulverization, and it is not preferable from the viewpoint of toner productivity because the surface of the toner is easily deteriorated or melted in the machine.
[0175]
Further, when the pulverized raw material is pulverized by a mechanical pulverizer, the inlet temperature of the mechanical pulverizer is 0 ° C. or lower, and is lowered by 60 to 75 ° C. with respect to the glass transition point (Tg) of the binder resin. Is preferable from the viewpoint of toner productivity. By setting the inlet temperature of the mechanical pulverizer to 0 ° C. or lower and lower by 60 to 75 ° C. than Tg, toner surface deterioration due to heat can be suppressed, and the pulverized raw material can be efficiently pulverized. The outlet temperature is preferably 5 to 30 ° C., more preferably 10 to 20 ° C. lower than Tg. By setting the outlet temperature of the mechanical pulverizer to be 5 to 30 ° C. lower than Tg, it is possible to suppress the toner surface deterioration due to heat and to efficiently pulverize the pulverized raw material.
[0176]
Further, the peripheral speed of the tip of the rotating rotor 314 is preferably 80 to 180 m / s, more preferably 90 to 170 m / s, and still more preferably 100 to 160 m / s. It is preferable from the point. The peripheral speed of the rotating rotor 314 is preferably 80 to 180 m / s, more preferably 90 to 170 m / s, and still more preferably 100 to 160 m / s, so that the toner is insufficiently pulverized or excessively pulverized. Therefore, the pulverized raw material can be efficiently pulverized. When the peripheral speed of the rotor is lower than 80 m / s, a short pass is easily caused without being pulverized, which is not preferable from the viewpoint of toner performance. Further, when the peripheral speed of the rotor 314 is higher than 180 m / s, the load on the apparatus itself increases, and at the same time, the toner is excessively pulverized at the time of pulverization, and the toner surface is easily deteriorated and fused in the machine. That is not preferable.
[0177]
The minimum distance between the rotor 314 and the stator 310 is preferably 0.5 to 10.0 mm, more preferably 1.0 to 5.0 mm, and still more preferably 1.0 to 3.0 mm. It is preferable that The distance between the rotor 314 and the stator 310 is preferably 0.5 to 10.0 mm, more preferably 1.0 to 5.0 mm, and still more preferably 1.0 to 3.0 mm. Thus, insufficient pulverization and excessive pulverization of the toner can be suppressed, and the pulverized raw material can be efficiently pulverized. If the distance between the rotor 314 and the stator 310 is larger than 10.0 mm, it is not preferable from the viewpoint of toner performance because a short pass is likely to occur without being pulverized. Further, when the distance between the rotor 314 and the stator 310 is smaller than 0.5 mm, the load on the apparatus itself increases, and at the same time, the toner is excessively pulverized during pulverization and is liable to cause toner surface alteration and in-machine fusion. Therefore, it is not preferable from the viewpoint of toner productivity.
[0178]
Since the pulverization method of the present invention does not require the first classification step before the pulverization step, electrostatic aggregation between particles is increased by making the toner into fine particles, so that the toner originally sent to the second classification means is again used. Fine powder and super fine powder which are excessively pulverized by being circulated to the first classifying means are not generated. Furthermore, in addition to a simple configuration, since a large amount of air is not required to pulverize the pulverized raw material, the power consumption is low and the energy cost can be kept low.
[0179]
Next, an airflow classifier that is preferably used as a classifying means constituting the toner manufacturing method of the present invention will be described.
[0180]
As an example of a preferable multi-division airflow classifier used in the present invention, an apparatus of the type shown in FIG. 6 (cross-sectional view) is illustrated as a specific example.
[0181]
In FIG. 6, the side wall 22 and the G block 23 form a part of the classification chamber, and the classification edge blocks 24 and 25 include the classification edges 17 and 18. The installation position of the G block 23 can be slid left and right. Further, the classification edges 17 and 18 can be rotated around the shafts 17a and 18a, and the classification edge tip position can be changed by rotating the classification edge. The classification edge blocks 24 and 25 can be slid left and right, and accordingly the knife edge type classification edges 17 and 18 also slide to the left and right. By the classification edges 17 and 18, the classification area 30 of the classification chamber 32 is divided into three.
[0182]
A raw material supply port 40 for introducing the raw material powder is provided at the rearmost end portion of the raw material supply nozzle 16, and a high pressure air nozzle 41 and a raw material powder introduction nozzle 42 are provided at the rear end portion of the raw material supply nozzle 16. The raw material supply nozzle 16 having an opening in the classification chamber 32 is provided on the right side of the side wall 22, and the Coanda block 26 is installed so as to draw an elliptical arc in the extending direction of the lower tangent of the raw material supply nozzle 16. . The left block 27 of the classification chamber 32 includes a knife-edge type inlet edge 19 on the right side of the classification chamber 32, and inlet tubes 14 and 15 that open to the classification chamber 32 are provided on the left side of the classification chamber 32. It is. In addition, as shown in FIG. 2, the inlet pipes 14 and 15 are provided with a first gas introduction adjusting means 20 and a second gas introduction adjusting means 21 such as a damper, and static pressure gauges 28 and 29.
[0183]
The positions of the classification edges 17 and 18, the G block 23, and the inlet edge 19 are adjusted according to the type of toner that is the classification processing raw material and the desired particle size.
[0184]
In addition, the upper surface of the classification chamber 32 has discharge ports 11, 12, and 13 that open to the classification chamber in correspondence with the respective classification areas, and the discharge ports 11, 12, and 13 have communication means such as pipes. It is connected, and each may be provided with opening / closing means such as valve means.
[0185]
The raw material supply nozzle 16 includes a right-angle cylinder part and a pyramidal cylinder part, and the ratio of the inner diameter of the right-angle cylinder part to the inner diameter of the narrowest part of the pyramid cylinder part is 20: 1 to 1: 1, preferably 10: 1. When it is set to 2: 1, a good introduction speed can be obtained.
[0186]
For example, the classification operation in the multi-division classification area configured as described above is performed as follows. That is, the classification chamber is depressurized through at least one of the discharge ports 11, 12, and 13, and the air current flowing by the depressurization and the high-pressure air supply nozzle 41 are injected through the raw material supply nozzle 16 having an opening in the classification chamber. Due to the ejector effect of compressed air, the powder is preferably sprayed into the classification chamber through the raw material supply nozzle 16 and dispersed at a flow rate of 10 to 350 m / s.
[0187]
The particles in the powder introduced into the classification chamber move along a curved surface due to the action of the Coanda effect of the Coanda block 26 and the action of a gas such as air flowing at that time. Depending on the magnitude of the inertial force, large particles (coarse particles) are the first fraction outside the air flow, ie outside the classification edge 18, intermediate particles are the second fraction between the classification edges 18 and 17, small particles Is classified into a third fraction inside the classification edge 17, the classified large particles are discharged from the discharge port 11, the classified intermediate particles are discharged from the discharge port 12, and the classified small particles are discharged from the discharge port 13, respectively.
[0188]
In the above powder classification, the classification point is mainly determined by the edge tip positions of the classification edges 17 and 18 with respect to the lower end portion of the Coanda block 26 where the powder jumps into the classification chamber 32. Furthermore, the classification point is affected by the suction flow rate of the classification airflow or the ejection speed of the powder from the raw material supply nozzle 16.
[0189]
In the toner production method and production system of the present invention, a toner having a sharp particle size distribution with a weight average diameter of 10 μm or less (particularly 8 μm or less) is obtained by controlling the pulverization and classification conditions. It can be generated efficiently.
[0190]
In order to produce the toner of the present invention, a mixture containing at least a binder resin and a wax component is used as a material. In addition, a pigment or dye as a colorant, a magnetic powder, a charge control agent, and Other additives are used. These materials are mixed thoroughly by a mixer such as a Henschel mixer or a ball mill, and then melted, kneaded and kneaded using a heat kneader such as a roll, a kneader and an extruder to make the resins compatible with each other. In addition, a toner can be obtained by dispersing or dissolving a pigment or dye, cooling and solidifying, and then performing pulverization and classification. In the present invention, an apparatus system having the above-described configuration is included in the pulverization process and classification process. Is preferably used.
[0191]
As a toner production apparatus, for example, as a mixer, a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.); a super mixer (manufactured by Kawata Corporation); a ribocorn (manufactured by Okawara Seisakusho Co., Ltd.); a nauter mixer, a turbulizer, a cyclomix (Hosokawa Micron Corporation) Spiral pin mixer (manufactured by Taiheiyo Kiko Co., Ltd.); Ladige mixer (manufactured by Matsubo Co., Ltd.), and KRC kneader (manufactured by Kurimoto Iron Works Co.); Bus co-kneader (manufactured by Buss) ); TEM type extruder (manufactured by Toshiba Machine Co., Ltd.); TEX twin-screw kneader (manufactured by Nippon Steel Works); PCM kneader (manufactured by Ikekai Iron Works Co., Ltd.); three roll mill, mixing roll mill, kneader (manufactured by Inoue Seisakusho Co., Ltd.) ); Needex (Mitsui Mining Co., Ltd.); MS pressure kneader, Nider Ruder (Moriyama Seisakusho); Banbury Miki -(Made by Kobe Steel Co., Ltd.), and the pulverizers include counter jet mill, micron jet, inomizer (manufactured by Hosokawa Micron); IDS type mill, PJM jet pulverizer (manufactured by Nippon Pneumatic Industrial Co., Ltd.); cross jet Mill (manufactured by Kurimoto Iron Works); Urmax (manufactured by Nisso Engineering Co., Ltd.); SK Jet O Mill (manufactured by Seishin Enterprise Co., Ltd.); Kryptron (manufactured by Kawasaki Heavy Industries, Ltd.); Classifiers include: Classy, Micron Classifier, Spedic Classifier (manufactured by Seishin Enterprise); Turbo Classifier (manufactured by Nisshin Engineering); Micron Separator, Turboplex (ATP), TSP Separator (Hosokawa Micron) Elbow Jet (Sun) Mining Co., Ltd.), Dispersion Separator (manufactured by Nippon Pneumatic Industrial Co., Ltd.); YM Micro Cut (manufactured by Yaskawa Shoji Co., Ltd.), and Ultrasonic (Sakae) used as a sieving device for sieving coarse particles Resona sieve, gyro shifter (Tokuju Kogakusha); Vibrasonic system (Dalton); Soniclean (Shinto Kogyo); Turbo screener (Turbo Kogyo); Micro shifter (Ogino Sangyo) A circular vibration sieve, etc.
[0192]
As a fixing device used in the present invention, as disclosed in Japanese Patent Application Laid-Open No. 59-33787, a device that achieves both energy saving (low power consumption) and improvement of user operability (quick print) is disclosed. As a source, an induction heating type fixing device using high frequency induction is used.
[0193]
In this induction heating fixing device, a coil is concentrically arranged inside a hollow fixing roller made of a metal conductor, and an induction eddy current is generated in the fixing roller by a high frequency magnetic field generated by flowing a high frequency current through the coil. The fixing roller itself generates Joule heat by the surface specific resistance of the fixing roller itself.
[0194]
According to the induction heating type fixing device, since the electric-heat conversion efficiency is extremely improved, the wait time can be shortened.
[0195]
Further, by combining the coil with a core (magnetic field blocking member) made of a magnetic material, a high-frequency magnetic field can be generated efficiently.
[0196]
In particular, when a T-shaped core is used, the amount of heat necessary for the fixing device can be generated with low power due to the effective concentration of high-frequency magnetic flux and the shielding effect of the magnetic field outside the heat generating part.
[0197]
Exemplary embodiments of a fixing device used in the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. .
[0198]
The heating device according to the embodiment of the present invention is applied to an image forming apparatus such as a copying machine or a printer. However, since the image forming apparatus is a known technique, a detailed description thereof will be omitted.
[0199]
In the following embodiments, a case where a heating device is applied as a so-called fixing device provided in an electrophotographic image forming apparatus will be described.
[0200]
The configuration in this case will be briefly described. A fixing device is used to form an unfixed toner image on a sheet by a known electrophotographic process, and then heat and press the sheet to fix the toner image. It is provided. A heating device (fixing device) according to an embodiment of the present invention will be described with reference to FIGS.
[0201]
8 to 10 are schematic sectional views of the fixing device according to the embodiment of the present invention.
[0202]
The fixing roller 501 is, for example, an iron cored bar cylinder having an outer diameter of 40 [mm] and a thickness of 0.7 [mm], for example, PTFE 10 to 50 [μm] or PFA 10 to improve surface releasability. It is configured by providing a layer of 50 [μm].
[0203]
The pressure roller 502 includes a hollow cored bar 514 and an elastic layer 515 that is a surface releasable heat-resistant rubber layer formed on the outer peripheral surface thereof.
[0204]
Bearing parts are formed at both ends of the pressure roller 502 and are rotatably attached to a fixing unit frame (not shown).
[0205]
The fixing roller 501 and the pressure roller 502 are rotatably supported, and are configured to drive only the fixing roller 501.
[0206]
The pressure roller 502 is in pressure contact with the surface of the fixing roller 501 and is arranged so as to be driven and rotated by the frictional force at the pressure contact portion (nip portion).
[0207]
The pressure roller 502 is pressed in the direction of the rotation axis of the fixing roller 501 by a mechanism (not shown) using, for example, a spring.
[0208]
The pressure roller 502 is loaded with, for example, about 294 [N], and the width (nip portion) of the pressure contact portion in that case is configured to be about [6 mm]. Of course, the nip width may be changed by changing the load in consideration of the use conditions and the like.
[0209]
The temperature sensor 506 is disposed so as to contact the surface of the fixing roller 501, and the surface temperature of the fixing roller 501 is increased or decreased by increasing or decreasing the power supply to the exciting coil 503 as the exciting means based on the detection signal of the temperature sensor 506. Is automatically controlled to be at a predetermined constant temperature.
[0210]
The conveyance guide 507 is disposed at a position for guiding the transfer material 516 conveyed while carrying the unfixed toner image 508 to the pressure contact portion (nip portion) between the fixing roller 501 and the pressure roller 502.
[0211]
The separation claw 510 is disposed in contact with or close to the surface of the fixing roller 501 to prevent the transfer material 516 from being wound around the fixing roller 501.
[0212]
The exciting coil 503 has a structure in which a lead wire is wound around a central protrusion of a magnetic core 504 having a T-shaped cross section (hereinafter referred to as a core) so that it can be placed along the inner peripheral surface of the fixing roller. It is arranged outside the holder 505 made of a heat resistant resin such as resin. An alternating current of 10 to 100 [kHz] is applied to the exciting coil 503.
[0213]
The magnetic field induced by the alternating current is guided to a core 504 as a magnetic field shielding means having a high magnetic permeability to generate magnetic flux and eddy current on the inner surface of the fixing roller 501 as a heat generating means. Joule heat is generated by the resistance.
[0214]
In order to increase the heat generation, it is preferable to increase the number of turns of the exciting coil 503, use a core 504 having a high magnetic permeability such as ferrite or permalloy and a low residual magnetic flux density, or increase the frequency of the alternating current.
[0215]
The core 504 has a T-shaped cross section extending in the direction of the rotation axis of the fixing roller 501 and blocks the magnetic field generated by excitation by the excitation coil 503 so as to concentrate the magnetic field toward the heating unit. It has become.
[0216]
When the surface temperature of the fixing roller 501 is adjusted to a predetermined temperature of 190 ° C. optimum for fixing with the above configuration, the exciting coil needs to be supplied with electric power of about 200 W. At this time, the temperature of the exciting coil is about 210 [° C.], and the temperature of the magnetic core is about 200 [° C.].
[0217]
In addition, when fixing a large amount continuously at a speed of about 30 sheets per minute, it is necessary to supply about 450 [W] to the exciting coil. At that time, the temperature of the exciting coil is about 230 [° C.], and the magnetic core The temperature is about 220 [° C.].
[0218]
In the above description, the fixing roller is used as the heating member. However, it is of course possible to adopt a configuration made of a thin metal film instead of the fixing roller.
[0219]
【Example】
Hereinafter, the present invention will be described with reference to specific examples.
[0220]
The waxes used in the examples and comparative examples are shown in Table 1. The DSC measurement results of wax 1 are shown in the figure.
[0221]
Next, a binder resin was prepared as follows.
[0222]
[Production Example 1 of Resin Composition]
Synthesis of low molecular weight polymer (L-1):
Into a four-necked flask, 300 parts by mass of xylene is added, and the inside of the container is sufficiently replaced with nitrogen while stirring, and then heated to reflux.
[0223]
Under this reflux, a mixture of 75 parts by mass of styrene, 18 parts by mass of acrylate-n-butyl, 7 parts by mass of monobutyl maleate and 2 parts by mass of di-tert-butyl peroxide was added dropwise over 4 hours. The polymerization was completed by maintaining the time, and a low molecular weight polymer (L-1) solution was obtained.
[0224]
Synthesis of high molecular weight polymer (H-1):
Into a four-necked flask, 180 parts by mass of degassed water and 20 parts by mass of a 2% by weight aqueous solution of polyvinyl alcohol were added, then 70 parts by mass of styrene, 25 parts by mass of acrylic acid-n-butyl, 5 parts by mass of monobutyl maleate, Add 0.005 parts by mass of divinylbenzene and 0.1 part by mass of 2,2-bis (4,4-di-tert-butylperoxycyclohexyl) propane (half-life 10 hours temperature; 92 ° C.), Stir to make a suspension.
[0225]
After sufficiently replacing the inside of the flask with nitrogen, the temperature was raised to 85 ° C. to initiate polymerization. After maintaining at the same temperature for 24 hours, 0.1 part by mass of benzoyl peroxide (temperature of 10 hours half-life; 72 ° C.) was additionally added. Furthermore, the polymerization was completed by maintaining for 12 hours. Thereafter, the high molecular weight polymer was filtered off, washed with water and dried.
[0226]
Production of resin composition (I):
In a four-necked flask, 100 parts by mass of xylene and 25 parts by mass of the high molecular weight polymer (H-1) are added, and the mixture is heated and stirred under reflux to perform preliminary dissolution. This state was maintained for 12 hours to obtain a preliminary solution (Y-1).
[0227]
On the other hand, 300 parts by mass of the homogeneous solution of the low molecular weight polymer (L-1) is charged into another container and refluxed. After the preliminary solution (Y-1) and the low molecular weight polymer (L-1) solution were mixed under reflux, the organic solvent was distilled off, and the resulting resin was cooled, solidified, pulverized, and then combined with toner. A resin composition (I) was obtained.
[0228]
When the resin composition (I) was analyzed, the main peak in the molecular weight distribution of GPC was Mw = 14700, the sub peak was Mw = 1.09 million, the THF-insoluble matter was 1.1% by mass, and the acid value was 23 mgKOH / g. .
[0229]
[Production Examples 2-5 of resin composition]
Synthesis of low molecular weight polymer (L-2-3):
Similarly to Production Example 1 of the resin composition, the amount of monobutyl maleate, styrene, n-butyl acrylate and the amount of initiator were adjusted to obtain low molecular weight polymers L-2 to L-3.
[0230]
Synthesis of high molecular weight polymer (H-2):
Similarly to the synthesis of the high molecular weight polymer (H-1), the amount of monobutyl maleate, styrene, n-butyl acrylate and the amount of initiator were adjusted to obtain a high molecular weight polymer (H-2).
[0231]
Synthesis of high molecular weight polymer H-3:
A 4-necked flask was charged with 85 parts by mass of styrene and 15 parts by mass of butyl methacrylate, and after bulk polymerization, solution polymerization was completed in the presence of a solvent by adding xylene, and a high molecular weight polymer (H-3) Got.
[0232]
Production of resin compositions (II) to (IV):
The high molecular weight polymers H-1 to H-3 and the low molecular weight polymers L-1 to L-3 are combined as shown in Table 2, and the resin compositions (II) to (IV) are prepared in the same manner as in Production Example 1 of the resin composition. Obtained. The results of molecular weight distribution and the like are shown in Table 2.
[0233]
Production of resin composition (V):
Without using monobutyl maleate, the amount of divinylbenzene and the initiator was adjusted, and the resin composition (V) having one peak in the molecular weight distribution was obtained in the same manner as the synthesis of the low molecular weight polymer (L-1). .
[0234]
<Example 1>
-Resin composition I 100 parts by mass
・ Magnetite (average particle size 0.25 μm) 100 parts by mass
-Illustrative azo-based iron complex compound (1) 2 parts by mass
・ 3 parts by weight of wax 1
・ 3 parts by weight of wax 10
The above raw materials are premixed with a Henschel mixer and then kneaded with a biaxial kneading extruder set at 120 ° C., and the resulting kneaded product is cooled and coarsely pulverized with a cutter mill to obtain a powder raw material A which is a coarsely pulverized product. It was.
[0235]
The powder raw material A was pulverized and classified by the apparatus system shown in FIG. A turbo mill T-250 type manufactured by Turbo Industry Co., Ltd. is used as the mechanical pulverizer 301. The distance between the rotor 314 and the stator 310 shown in FIG. 3 is 1.5 mm, and the peripheral speed of the rotor 314 is 115 m / d.
[0236]
In the present example, the powder raw material made of coarsely pulverized material was supplied to the mechanical pulverizer 301 at a rate of 40 kg / h by the table-type first fixed quantity supply device 315 and pulverized. The powder raw material pulverized by the mechanical pulverizer 301 is collected by the cyclone 229 while being entrained by the suction air from the exhaust fan 224, and is introduced into the second metering feeder 2. At this time, the inlet temperature in the mechanical pulverizer was −10 ° C., the outlet temperature was 47 ° C., and the temperature difference ΔT between the inlet temperature and the outlet temperature was 57 ° C. At this time, the finely pulverized product A-1 obtained by pulverization by the mechanical pulverizer 301 has a weight average diameter of 6.5 μm, particles having a particle diameter of 4.0 μm or less, 42.3% by number, and It had a sharp particle size distribution containing 3.4% by volume of particles having a particle size of 10.1 μm or more.
[0237]
Next, the finely pulverized product A-1 obtained by pulverization by the mechanical pulverizer 301 is introduced into the second fixed amount feeder 2, and 44 kg / h is passed through the vibration feeder 3 and the raw material supply nozzle 16. It introduced into the airflow classifier 1 which has the structure of FIG. In the airflow classifier 1, the Coanda effect is used to classify into three types of particle sizes: coarse powder, medium powder, and fine powder. When introduced into the airflow classifier 1, the classification chamber is depressurized via at least one of the discharge ports 11, 12, and 13, and the airflow flowing through the raw material supply nozzle 16 having an opening in the classification chamber by the depressurization. Compressed air injected from the high pressure air supply nozzle 41 was used. The introduced finely pulverized product was classified into three types of coarse powder, medium powder A-2 and fine powder in an instant of 0.1 seconds or less. Of the classified materials, the coarse powder was collected by the collecting cyclone 6 and then introduced into the mechanical pulverizer 301 described above at a rate of 2.0 kg / h and again introduced into the pulverization step.
[0238]
The intermediate powder A-2 (classified product) classified in the above classification step has a weight average diameter of 6.8 μm, 20.5% by number of particles having a particle size of 4.0 μm or less, and a particle size of 10.5. It had a sharp particle size distribution containing 2.7% by volume of particles of 1 μm or more.
[0239]
Hydrophobic silica fine powder (BET120m) with respect to 100 parts by mass of the medium powder A-2100²/ G) Externally added 1.0 part by mass and 0.8 part by mass of strontium titanate with an equivalent circle diameter of 1.8 μm using a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.). Toner 1 was obtained. The DSC measurement result of Toner 1 is shown in FIG.
[0240]
Table 4 shows the results of the toner 1 fixing test and tailing evaluation. As a result, good fixing characteristics were obtained and no tailing occurred.
[0241]
(Low temperature fixability and cold offset resistance test)
The fixing device of the electromagnetic induction type fixing device shown in FIG. 12 can be arbitrarily set, and an external fixing device having a process speed of 100 mm / sec, a pressing force of 83 N, and a nip of 6 mm was used. Under an environment of 15 ° C. and 10% RH, the external fixing device is temperature-regulated every 5 ° C. within a temperature range of 130 to 200 ° C., and 90 g / m at each temperature.²A non-fixed image obtained by developing a halftone image of 1 dot and 2 spaces was fixed on a bond paper of 5 mm, and the obtained image was rubbed back and forth 5 times with sylbon paper applied with a load of 4.9 kPa. The point at which the density reduction rate of density is 5% or less was defined as the fixing temperature. The lower this temperature, the better the low-temperature fixability.
[0242]
With respect to the cold offset resistance, the temperature at which the stain due to the offset phenomenon occurred on the image in the fixing test was visually confirmed. The lower this temperature, the better the cold offset resistance.
[0243]
(Tailing)
The external fixing device used in the low-temperature fixing property and cold offset resistance test was set at a fixing temperature of 210 ° C., and 75 g / m.²The paper used was left at 32.5 ° C. and 80% RH for one day.
[0244]
The evaluation method for tailing is to print out a pattern of 4 dots horizontal lines printed in 20-dot space on the high-humidity environment paper, and pass it through the external fixing device set as above. I counted the number I subtracted.
: No occurrence
○: Less than 3
○ △: Less than 3-7
Δ: Less than 7-10
Δ ×: less than 10-15
×: 15 or more
[0245]
  <Example 214, Reference Examples 15-18, Example 19And Comparative Examples 1-2>
  In the same manner as in Example 1, except that the resin composition, the wax, the toner particle size, and the addition amount of strontium titanate as an external additive are changed as shown in Table 3,21And evaluated in the same manner as in Example 1. The relationship between the toner weight average particle diameter D4 (μm) and the number-based cumulative value (%) of toner particles having a circularity of 0.950 or more is shown in FIGS. Table 4 shows the results of fixing tests and tailing evaluation of these toners.
[0246]
[Table 1]

[0247]
[Table 2]

[0248]
[Table 3]

[0249]
[Table 4]

[0250]
【The invention's effect】
According to the present invention, by combining the image forming method having the above-described configuration and toner, the low-temperature fixing property and cold offset resistance of a halftone image in a low-temperature environment are excellent, and no tailing occurs in a high-humidity environment. A toner and an image forming method can be provided.
[Brief description of the drawings]
FIG. 1 is a flowchart for explaining a toner production method of the present invention.
FIG. 2 is a schematic view showing a specific example of an apparatus system for carrying out the toner manufacturing method of the present invention.
FIG. 3 is a schematic cross-sectional view of an example of a mechanical pulverizer used in the toner pulverization step of the present invention.
4 is a schematic cross-sectional view taken along a D-D ′ plane in FIG. 3;
5 is a perspective view of the rotor shown in FIG. 3. FIG.
FIG. 6 is a schematic cross-sectional view of a multi-split airflow classifier used in the toner classification process of the present invention.
FIG. 7 is a schematic sectional view of a conventional collision-type airflow crusher.
FIG. 8 is a schematic cross-sectional view of a fixing device according to an embodiment of the present invention.
FIG. 9 is a schematic sectional view of a fixing device according to an embodiment of the present invention.
FIG. 10 is a schematic cross-sectional view of a fixing device according to an embodiment of the present invention.
FIG. 11 is a DSC curve when the temperature of the wax 1 is raised.
FIG. 12 is a DSC curve when toner 1 is heated.
FIG. 13 is a graph showing the relationship between the toner weight average particle diameter D4 (μm) and the number-based cumulative value (%) of toner particles having a circularity of 0.950 or more.
FIG. 14 is a diagram illustrating a relationship between a toner weight average particle diameter D4 (μm) and a number-based cumulative value (%) of toner particles having a circularity of 0.950 or more.
[Explanation of symbols]
1: Multi-division classifier
2: Second metering machine
3: Vibration feeder
4,5,6: Collection cyclone
11, 12, 13: discharge port
11a, 12a, 13a: discharge conduit
14, 15: Intake tube
16: Raw material supply nozzle
17, 18: Classification edge
19: Inlet edge
20: First gas introduction adjusting means
21: Second gas introduction adjusting means
22, 23: Side wall
24, 25: Classification edge block
26: Coanda block
27: Left block
28, 29: Static pressure gauge
30: Classification area
32: Classification room
40: Raw material supply port
41: High-pressure air nozzle
42: Raw material powder introduction nozzle
65: Injection feeder
161: High-pressure gas supply nozzle
162: Accelerating tube
163: Acceleration tube exit
164: Colliding member
165: Raw material supply port
166: Colliding surface
167: Ground product outlet
212: Swirl chamber
219: Pipe
220: Distributor
222: Bug filter
224: Suction filter
229: Supplementary cyclone
301: Mechanical crusher
302: Powder outlet
310: Stator
311: Powder inlet
312: Rotating shaft
313: Casing
314: Rotor
315: First metering feeder
316: Jacket
317: Cooling water supply port
318: Cooling water outlet
320: rear room
321: Cold air generating means
501: Rotating heating member (fixing roller)
502: Rotating pressure member (pressure roller)
503: Excitation coil (magnetic field generating means)
504: Core
505: Holder
506: Temperature sensor
507: Transport guide
508: Toner image
510: separation nail
511: Heat generation layer
512: Release layer
513: Fixed image
514: Hollow cored bar
515: elastic layer
516: Transfer material (recording material)
N: Nip

Claims (30)

(Ii) a magnetic field generating means; (ii) a rotary heating member having at least a heat generating layer and a release layer that generate heat by electromagnetic induction; and (iii) a rotary pressure member that forms a nip with the rotary heating member. A toner applied to an image forming method for forming a fixed image on a recording material by heating and fixing the toner image on the recording material while pressing the rotary heating member through the recording material;
The toner contains at least a binder resin and a wax component, and the peak top temperature (P1) of the maximum endothermic peak is in the range of 70 to 120 ° C. in the DSC curve at the time of temperature rise measured by a differential scanning calorimeter of the toner. And at least one peak top temperature (P2) of an endothermic peak exists in the range of 120 to 160 ° C. ,
In addition, in the toner having a weight average particle diameter of 5 to 12 μm and a particle of 3 μm or more of the toner, 90% or more of particles having a circularity a = 0.900 or more obtained from the following formula are accumulated based on the number. Have
Circularity a = L ₀ / L
(In the formula, L ₀ represents the circumference of a circle having the same projected area as the particle image, and L represents the circumference of the particle image.)
And,
a) The relationship between the cut rate Z and the toner weight average diameter X is
Cut rate Z ≦ 5.3 × X
[However, the cut rate Z is expressed by the following formula, where A is the total number of particles and B is the number of measured particles of 3 μm or more .
Z = (1-B / A) × 100]
And the relationship between the number-based cumulative value Y of particles having a circularity of 0.950 or more and the toner weight average diameter X is
Number-based cumulative value Y ≧ exp5.51 × X ^−0.645 of particles having a circularity of 0.950 or more
[However, toner weight average diameter X: 5.0 to 12.0 (μm)]
Or
b) The relationship between the cut rate Z and the toner weight average diameter X is
Cut rate Z> 5.3 × X
And the relationship between the number-based cumulative value Y of particles having a circularity of 0.950 or more and the toner weight average diameter X is
Number-based cumulative value of particles having a circularity of 0.950 or more Y ≧ exp5.37 × X ^−0.545
[However, toner weight average diameter X: 5.0 to 12.0 (μm)]
A toner characterized by satisfying   The DSC curve at the time of temperature rise measured by a differential scanning calorimeter of the toner has a peak top temperature (P1) of a maximum endothermic peak in a range of 70 to 80 ° C. toner. In the DSC curve at the time of Atsushi Nobori measured by a differential scanning calorimeter of the toner, according to claim 1 or, characterized in that the endothermic peak of the peak top temperature (P2) is at least one existing in the range of 130 to 150 ° C. 2. The toner according to 2 . The toner has a maximum endothermic peak at 70 ° C. to 120 ° C. at the endothermic peak at the temperature rise measured by DSC and a maximum endothermic peak at the endothermic peak at the temperature rise measured by DSC. the toner according to any one of claims 1 to 3 peak top temperature is characterized by containing a wax B is 120 to 160 ° C.. The toner according to claim 4 , wherein the wax A has a peak top temperature of a maximum endothermic peak of 70 to 80 ° C. at an endothermic peak at a temperature rise measured by DSC. 6. The toner according to claim 4 , wherein the wax A has a peak half-value width of 12 ° C. or less at the maximum endothermic peak of the endothermic peak at the time of temperature rise measured by DSC. 6. The toner according to claim 4 , wherein the wax A has a peak half-value width of 8 ° C. or less at the maximum endothermic peak of the endothermic peak at the time of temperature rise measured by DSC. Of the wax A, starting onset temperature at an endothermic peak during heating as measured by DSC is not less 50 ° C. or more, more of claims 4 to 7 endpoint onset temperature is equal to or is 100 ° C. or less Toner according to the above. Of the wax A, starting onset temperature at an endothermic peak during heating as measured by DSC is at 60 ° C. or more, more of claims 4 to 7 endpoint onset temperature is equal to or is 90 ° C. or less Toner according to. The wax A, the toner according to any one of claims 4 to 9 melt viscosity at 120 ° C. as measured by E-type viscometer is equal to or less than 100 mPa · s. The wax A, the toner according to any one of claims 4 to 9 melt viscosity at 120 ° C. as measured by E-type viscometer, characterized in that a 1 to 50 mPa · s. The toner according to claim 4 , wherein the wax B has a peak top temperature of a maximum endothermic peak of 130 to 150 ° C. in an endothermic peak at a temperature rise measured by DSC. The toner according to claim 4 , wherein the wax B is a polyolefin wax or a Fischer-Tropsch wax. The combination of the waxes A and B is selected from any of a combination of Fischer-Tropsch wax and polyolefin wax, a combination of paraffin wax and polyolefin wax, or a combination of paraffin wax and Fischer-Tropsch wax. The toner according to any one of 4 to 13 . The toner resin component has a main peak in the molecular weight region of 3 × 10 ^{3 to} 3 × 10 ⁴ and a molecular weight region of 1 × 10 ^{5 to} 3 × 10 ⁶ in the GPC chromatogram of the THF soluble component. the toner according to any one of claims 1 to 14, characterized in that it has a sub-peak or shoulder in. An image forming method for forming a fixed image on a recording material by heating and fixing a toner image on the recording material by a heating and pressing unit
The toner forming the toner image contains at least a binder resin and a wax component, and the peak top temperature (P1) of the maximum endothermic peak in the DSC curve at the time of temperature rise measured by the differential scanning calorimeter of the toner is Exists in the range of 70 to 120 ° C., and at least one peak top temperature (P2) of the endothermic peak exists in the range of 120 to 160 ° C.,
In addition, in the toner having a weight average particle diameter of 5 to 12 μm and a particle of 3 μm or more of the toner, 90% or more of particles having a circularity a = 0.900 or more obtained from the following formula are accumulated based on the number. Have
Circularity a = L ₀ / L
(In the formula, L ₀ represents the circumference of a circle having the same projected area as the particle image, and L represents the circumference of the particle image.)
And,
a) The relationship between the cut rate Z and the toner weight average diameter X is
Cut rate Z ≦ 5.3 × X
[However, the cut rate Z is expressed by the following formula, where A is the total number of particles measured by Toago Medical Electronics' flow type particle image analyzer FPIA-1000, and B is the number of particles measured 3 μm or more.
Z = (1-B / A) × 100]
And the relationship between the number-based cumulative value Y of particles having a circularity of 0.950 or more and the toner weight average diameter X is
Number-based cumulative value Y ≧ exp5.51 × X ^−0.645 of particles having a circularity of 0.950 or more
[However, toner weight average diameter X: 5.0 to 12.0 (μm)]
Or
b) The relationship between the cut rate Z and the toner weight average diameter X is
Cut rate Z> 5.3 × X
And the relationship between the number-based cumulative value Y of particles having a circularity of 0.950 or more and the toner weight average diameter X is
Number-based cumulative value of particles having a circularity of 0.950 or more Y ≧ exp5.37 × X ^−0.545
[However, toner weight average diameter X: 5.0 to 12.0 (μm)]
Satisfied,
The heating and pressing means includes (i) a magnetic field generating means, (ii) a rotary heating member having at least a heat generating layer and a release layer that generate heat by electromagnetic induction, and (iii) forming a nip with the rotary heating member. An image forming method comprising: forming a fixed image on a recording material by heating and fixing a toner image on the recording material while pressing the rotary heating member through the recording material with the rotating pressure member. In the DSC curve at the time of Atsushi Nobori measured by a differential scanning calorimeter of the toner, according to claim 16, the maximum endothermic peak of the peak top temperature (P1) is characterized by the presence in the range of 70 to 80 ° C. Image forming method. In the DSC curve at the time of Atsushi Nobori measured by a differential scanning calorimeter of the toner, according to claim 16 or, characterized in that the endothermic peak of the peak top temperature (P2) is at least one existing in the range of 130 to 150 ° C. The image forming method according to 17 . The toner has a maximum endothermic peak of 70 to 120 ° C. at the endothermic peak at the time of temperature rise measured by DSC, and a maximum endothermic peak at the endothermic peak at the time of temperature rise measured by DSC. The image forming method according to claim 16 , comprising wax B having a peak top temperature of 120 to 160 ° C. 20. The image forming method according to claim 19 , wherein the wax A has a peak top temperature of 70 to 80 [deg.] C. at the endothermic peak at the time of temperature rise measured by DSC. 21. The image forming method according to claim 19 , wherein the wax A has a peak half-value width of 12 ° C. or less at the maximum endothermic peak of the endothermic peak at the time of temperature rise measured by DSC. 21. The image forming method according to claim 19 , wherein the wax A has a peak half-value width of 8 ° C. or less at the maximum endothermic peak of the endothermic peak at the time of temperature rise measured by DSC. Of the wax A, starting onset temperature at an endothermic peak during heating as measured by DSC is not less 50 ° C. or more, any of claims 19 to 22 end point onset temperature is equal to or is 100 ° C. or less An image forming method according to claim 1. Of the wax A, starting onset temperature at an endothermic peak during heating as measured by DSC is at 60 ° C. or more, any of claims 19 to 22 end point onset temperature is equal to or is 90 ° C. or less An image forming method according to claim 1. The wax A, an image forming method according to any one of claims 19 to 24 melt viscosity at 120 ° C. as measured by E-type viscometer is equal to or less than 100 mPa · s. The wax A, an image forming method according to any one of claims 19 to 24 melt viscosity at 120 ° C. as measured by E-type viscometer, characterized in that a 1 to 50 mPa · s. The image forming method according to claim 19 , wherein the wax B has a peak top temperature of a maximum endothermic peak of 130 to 150 ° C in an endothermic peak at the time of temperature rise measured by DSC. The image forming method according to any one of claims 19 to 27 , wherein the wax B is a polyolefin wax or a Fischer-Tropsch wax. The combination of the waxes A and B is selected from a combination of Fischer-Tropsch wax and polyolefin wax, a combination of paraffin wax and polyolefin wax, or a combination of paraffin wax and Fischer-Tropsch wax. 29. The image forming method according to any one of 19 to 28 . The toner resin component has a main peak in the molecular weight region of 3 × 10 ^{3 to} 3 × 10 ⁴ and a molecular weight region of 1 × 10 ^{5 to} 3 × 10 ⁶ in the GPC chromatogram of the THF soluble component. the image forming method according to any one of claims 19 to 29, characterized in that it has a sub-peak or shoulder in.

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