JP3584141B2 - Resin composition for electrophotographic toner and toner composition containing the same - Google Patents

Description

上記表において、重合の各工程の間に、他の必要な工程を組み込むことは、何ら問題ない。
【００３７】
パターン１について具体的に示すならば、下記のようであるが、本発明が以下の方法に限定されるものではない。
（１）塊状重合；重合系内に所定のＴｇとなるように選択されたエチレン系単量体、重合開始剤を仕込み、系の温度を９０〜１２０℃にて６〜１６時間重合する。この塊状重合の重合時間の終了においては、溶剤を添加することにより重合熱を除去すると共に、連鎖移動を促進させ重合を停止させる。
【００３８】
なお本発明で使用する重合体を重合する際に使用する重合開始剤はラジカル重合で使用する公知のものが用いられ、例えばｔ−ブチルペルオキシメタクリレート、ｔ−ブチルペルオキシクロトネート、ジ（ｔ−ブチルペルオキシ）フマレート、ｔ−ブチルペルオキシアリルカーボネート、過トリメリット酸トリ−ｔ−ブチルエステル、過トリメリット酸トリ−ｔ−アミノエステル、過トリメリット酸トリ−ｔ−ヘキシルエステル、過トリメリット酸トリ−ｔ−１、１、３、３−テトラメチルブチルエステル、過トリメリット酸トリ−ｔ−クミルエステル、過トリメリット酸トリ−ｔ−（ｐ−イソプロピル）クミルエステル、過トリメシン酸トリ−ｔ−ブチルエステル、過トリメシン酸トリ−ｔ−アミノエステル、過トリメシン酸トリ−ｔ−ヘキシルエステル、過トリメシン酸トリ−ｔ−１、１、３、３−テトラメチルブチルエステル、過トリメシン酸トリ−ｔ−クミルエステル、過トリメシン酸トリ−ｔ−（ｐ−イソプロピル）クミルエステル、２、２−ビス（４、４−ジ−ｔ−ブチルパーオキシシクロヘキシル）プロパン、２、２−ビス（４、４−ジ−ｔ−ヘキシルパーオキシシクロヘキシル）プロパン、２、２−ビス（４、４−ジ−ｔ−アミルパーオキシシクロヘキシル）プロパン、２、２−ビス（４、４−ジ−ｔ−オクチルパーオキシシクロヘキシル）プロパン、２、２−ビス（４、４−ジ−α−クミルパーオキシシクロヘキシル）プロパン、２、２−ビス（４、４−ジ−ｔ−ブチルパーオキシシクロヘキシル）ブタン、２、２−ビス（４、４−ジ−ｔ−オクチルパーオキシシクロヘキシル）ブタン。
【００３９】
イソブチリルパーオキサイド、α，α’−ビス（ネオデカノイルパーオキシ）ジイソプロピルベンゼン、クミルパーオキシネオデカノエート、ジ−ｎ−プロピルパーオキシジカーボネート、ジイソプロピルパーオキシジカーボネート、１，１，３，３−テトラメチルブチルパーオキシネオデカノエート、ビス（４−ｔ−ブチルシクロヘキシル）パーオキシジカーボネート、１−シクロヘキシル−１−メチルエチルパーオキシネオデカノエート、ジー２−エトキシエチルパーオキシジカーボネート、ジ（２−エチルヘキシルパーオキシ）ジカーボネート、１−ヘキシルパーオキシネオデカノエート、ジメトキシブチルパーオキシジカーボネート、ジ（３−メチル−３−メトキシブチルパーオキシ）ジカーボネート、ｔ−ブチルパーオキシネオデカノエート、２，４−ジクロロベンゾイルパーオキサイド、１−ヘキシルパーオキシピバレート、１，１−ビス（ｔ−ブチルパーオキシ）シクロヘキサン、２，２−ビス（４，４−ジ−ｔ−ブチルパーオキシシクロヘキセニル）プロパン、１，１−ビス（ｔ−ブチルパーオキシ）シクロデカン、１−ヘキシルパーオキシイソプロピルモノカーボネート、ｔ−ブチルパーオキシマレイックアシッド、ｔ−ブチルパーオキシ−３，５，５−トリメチルヘキサノエート、ｔ−ブチルパーオキシラウレート、２，５ジメチル−２，５−ジ（ｍ−トルオイルパーオキシ）ヘキサン、ｔ−ブチルパーオキシイソプロピルモノカーボネート、ｔ−ブチルパーオキシ−２−エチルヘキシルモノカーボネート、１−ヘキシルパーオキシベンゾエート、２，５−ジ−メチル−２，５−ジ（ベンゾイルパーオキシ）ヘキサン、ｔ−ブチルパーオキシアセテート、２，２−ビス（ｔ−ブチルパーオキシ）ブタン、ｔ−ブチルパーオキシベンゾエート、ｎ−ブチル−４，４−ビス（ｔ−ブチルパーオキシ）バレレート、ｔ−ブチルパーオキシビバレート、３，３，５−トリエチルヘキサノイルパーオキシド、オクタノイルパーオキシド、ラウロイルパーオキシド、ステアロイルパーオキシド、１，１，３，３−テトラメチルブチルパーオキシ−２−エチルヘキサノエート、サクシニックパーオキシド、２，５−ジメチル−２，５−ジ（２−エチルヘキサノイルパーオキシ）ヘキサン、１−シクロヘキシル−１−メチルエチルパーオキシ−２−エチルヘキサノエート、１−ヘキシルパーオキシ−２−エチルヘキサノエート、ｔ−ブチルパーオキシ−２−エチルヘキサノエート、ｍ−トルイル アンド ベンゾイルパーオキシド、ベンゾイルパーオキシド、ｔ−ブチルパーオキシイソブチレート、
１，１−ビス（１−ヘキシルパーオキシ）−３，３，５−トリメチルシクロヘキサン、１，１−ビス（１−ヘキシルパーオキシ）シクロヘキサン、１，１−ビス（１−ブチルパーオキシ）−３，３，５−トリメチルシクロヘキサン、ジ−ｔ−ブチルパーオキシイソフタレート、α，α’−ビス（ｔ−ブチルパーオキシ）ジイソプロピルベンゼン、ジクミルパーオキシド、２，５−ジメチル−２，５−ジ（ｔ−ブチルパーオキシ）ヘキサン、ｔ−ブチルクミルパーオキシド、ジ−ｔ−ブチルパーオキサイド、ｐ−メンタンハイドロパーオキサイド、２，５−ジメチル−２，５−ジ（ｔ−ブチルパーオキシ）ヘキサン−３、ジイソプロピルベンゼンハイドロパーオキサイド、ｔ−ブチルトリメチルシリルパーオキサイド、１，１，３，３−テトラメチルブチルハイドロパーオキサイド、クメンハイドロパーオキサイド、１−ヘキシルハイドロパーオキサイド、ｔ−ブチルハイドロパーオキサイド、２，３−ジメチル−２，３−ジフェニルブタンなどを例示することが出来、これらの１種または２種以上の組み合わせで用いることができる。
【００４０】
（２）溶液重合；上記の塊状重合が終了した系にトルエンまたはキシレンなどの溶剤、Ｔｇを調整するために所定のエチレン系単量体の組成を変更した単量体および重合開始剤を１００〜１４０℃の温度で５〜１０時間かけて連続滴下する。更に好ましくは、連続滴下の工程で、時間とともに滴下物の組成を変化させる（グラジエントモノマーフィード）ことにより、特に好ましいエチレン系重合体（Ｈ）を得ることができるようになる。
【００４１】
（３）後重合；溶液重合と同じ温度または＋１０℃の温度幅にて１〜３時間熱重合させる。
【００４２】
（４）残モノマー重合；７０〜１１０℃の温度にて開始剤を加えて重合率が９７〜１００％になるように重合を完結させる。
【００４３】
Ｔｇに分布を持たせるために、重合段階でエチレン系単量体の組成を変化させ、例えばスチレン系単量体を使用する場合は塊状重合および溶液重合の各段階で使用するスチレン単量体の割合を割合（塊状重合時）＜割合（溶液重合時）とすることが好ましい。
【００４４】
所望によるが、多官能性単量体を（１）塊状重合および／または（２）溶液重合の段階で単量体として使用してもよい。その使用量としては、本発明の重合体（Ｈ）を構成する単量体総量内で０．０〜１５．０重量％、好ましくは０．１〜１０重量％、さらに好ましくは１〜７重量％である。
【００４５】
また、懸濁重合法により製造する場合に、その方法は、重合性単量体を０．１〜５０重量％の懸濁安定剤（例えば、難溶性無機分散剤）を含有する水性媒体（例えば重合温度よりも５℃以上、好ましくは１０℃以上の温度に加温されている）中に通常の撹拌機又はホモミキサー、ホモジナイザなどにより分散せしめる。その後、分散安定剤の作用によりほぼその状態が維持される様、撹拌を粒子の沈降が防止される程度に行ないながら、水性媒体の液温を重合温度まで下げる。重合温度は５０℃以上、好ましくは５５〜８０℃、特に好ましくは６０℃〜７５℃の温度に設定し、撹拌しながら実質的に非水溶性の重合開始剤を添加し重合を行なう。
【００４６】
反応終了後、生成した重合体を洗浄、ろ過、デカンテーション、遠心等の如き適当な方法により回収し乾燥する。懸濁重合法においては、通常重合性単量体１００重量部に対し水２００〜３０００重量部を水性分散媒として使用する。
【００４７】
また、適当な安定化剤、例えばポリビニルアルコール、ゼラチン、メチルセルロース、メチルハイドロプロピルセルロース、エチルセルロース、カルボキシメチルセルローズのナトリウム塩、ポリアクリル酸およびそれらの塩、デンプン、ガムアルギン酸塩、ゼイン、カゼイン、リン酸三カルシウム、タルク、硫酸バリウム、ベントナイト、水酸化アルミニウム、水酸化第２鉄、水酸化チタン、水酸化ナトリウム等のいずれか１種または混合物を水性媒体に本発明の製造方法に悪影響を与えない程度に包含されたものも使用しても良い。
【００４８】
また、前記無機分散剤の均一な分散のために、界面活性剤を本発明の製造方法に悪影響を与えない程度に使用することもよい。これは上記分散安定化剤の所期の作用を促進するためのものであり、その具体例としては、ドデシルベンゼンスルホン酸ナトリウム、テトラデシル硫酸ナトリウム、ペンタデシル硫酸ナトリウム、オクチル硫酸ナトリウム、アリル−アルキル−ポリエーテルスルホン酸ナトリウム、オレイン酸ナトリウム、ラウリン酸ナトリウム、カプリン酸ナトリウム、カプリン酸ナトリウム、カプロン酸ナトリウム、ステアリン酸カリウム、オレイン酸カルシウム、３，３−ジスルホンジフェニル尿素−４，４−ジアゾ−ビス−アミノ−８−ナフトール−６−スルホン酸ナトリウム、オルト−カルボキシベンゼン−アゾ−ジメチルアニリン、２，２，５，５−テトラメチル−トリフェニルメタン−４，４−ジアゾ−ビス−β−ナフトール−ジスルホン酸ナトリウム、その他を挙げることができる。また、水に易溶性のモノマーは水中で乳化重合を同時におこし、できた懸濁重合物を小さな乳化重合粒子で汚すので水溶性の重合禁止剤、例えば金属塩等を加えて水相での乳化重合を防ぐこともよい。又、水性媒体の粘度をまして重合時の粒子の合一を防ぐために、水にグリセリン、グリコールなどを添加する事も可能である。又、易溶性モノマーの水への溶解度減少のためにＮａＣｌ，ＫＣｌ，Ｎａ_２ＳＯ_４などの塩類または極性基のイオン性を高めるために塩酸の如きブレンステッド酸を水性媒体へ添加することも可能である。
【００４９】
使用される重合開始剤は、実質的に非水溶性のものであり、室温にて水１００ｇに対して好ましくは１ｇ以下の溶解度を有するものであり、より好ましくは水１００ｇに対して０．５ｇ以下、特に好ましくは水１００ｇに対して０．２ｇ以下の低溶解度を有するものである。水１００ｇに対して１ｇを以下の溶解度を有するものであれば、重合終了後に重合体粒子表面に残存する重合開始剤の分解生成物が、トナーとしたときの耐湿性を低下しないので好ましい。
【００５０】
使用する重合開始剤は重合性単量体に可溶であり、通常使用する量範囲（単量体１００重量部に対して重合開始剤２〜５重量部）では良好に重合性単量体に溶解する特性を有するものである。本発明に使用可能な重合開始剤として、２，２’−アゾビス−（２，４−ジメチルバレロニトリル）、２，２’−アゾビスイソブチロニトリル、１，１’−アゾビス（シクロヘキサン−１−カルボニトリル）、２，２’−アゾビス−４−メトキシ−２，４−ジメチルバレロニトリル、その他のアゾビスイソブチロニトリル（ＡＩＢＮ）の如きアゾ系またはジアゾ系重合開始剤；ベンゾイルパーオキサイド、メチルエチルケトンパーオキサイド、イソプロピルパーオキシカーボネート、キュメンハイドロパーオキサイド、２，４−ジクロリルベンゾイルパーオキサイド、ラウロイルパーオキサイドの如き過酸化物系重合開始剤が挙げられる。本発明の製造方法において、重合開始剤は重合温度（通常５０℃以上）と同等またはそれ以外の融点を有するものが好ましい。また、重合体の分子量および分子量分布を調節する目的でまたは反応時間を調節する目的等で二種類またはそれ以上の重合開始剤を混合して使用することも好ましい。
【００５１】
その場合、少なくとも１種は、重合時の水性媒体中の液温に相当する温度またはそれ以下の温度の融点を有するものを使用することが好ましい。何故ならば、重合反応時の液温で重合開始剤が油状化しているので、水性媒体へ添加後に分散されている各単量体組成物粒子へ重合開始剤または重合開始剤から生成するラジカルがより良好に付与されるからである。ちなみに、実施例で使用している２，２’−アゾビス−（２，４−ジメチルバレロニトリル）はメソ体とｄｌ体との混合物であり、該混合物は約４５℃で融解を始め約７０℃で融解が終了する。重合開始剤の使用量は、重合性単量体１００重量部に対して０．１〜２０重量部、好ましくは１〜１０重量部である。
【００５２】
懸濁重合反応は、通常重合温度５０℃以上でおこなわれ、重合開始剤の分解速度を考慮して上限温度が設定される。設定重合温度が高すぎると、重合開始剤が急激に分解されてしまうので好ましくない。本発明においては、懸濁造粒時には重合開始剤を単量体組成物中に存在させる必要がないため、造粒時の水性媒体の液温を例えば７５℃以上にして単量体組成物の溶融粘度を低下させることにより、造粒を容易におこなうことが可能である。
【００５３】
形成された単量体組成物粒子が所定粒度を有していることを確認して後に、該粒子を含む水性媒体の液温を重合温度（例えば５５〜７０℃）に下げて後に、重合開始剤を添加する。水性媒体の液温を下げることにより、単量体組成物粒子の保形性も向上し、粒子同士の合一も抑制される。重合反応時間は、重合開始剤の種類および重合温度で変動するが、通常は、２〜３０時間である。
【００５４】
また、重合体（Ｈ）の重合に際しては、どのパターンの重合方法を選択するにしても、多官能性単量体を用いることが好ましく、これは重合体（Ｈ）に適度なミクロ架橋構造を持たせることにより、結着樹脂に適度な強度を持たせ、更には結着樹脂の中に一部非相溶な部分を設けることにより、溶融流動性と適度な弾性を持たせるためである。本発明のエチレン系重合体（Ｈ）の製造法は、上記に限定されるものではない。
【００５５】
次に、本発明の電子写真トナー用樹脂を構成する重合体（Ｌ）については、Ｍｗが３，０００〜５０，０００、より好ましくは３，０００〜３５，０００、より好ましくは３，０００〜３０，０００であり、Ｔｇは４０〜８０℃、好ましくは４５〜７０℃である。
【００５６】
重合成分（Ｌ）は好ましくは連続加圧重合法により製造されるものであり、特に好ましくは該重合体の構成単位として、前記記載の単量体から酸性単量体（カルボキシル基を持つ単量体）を一部選択して、酸価（以下、ＡＶと記す）で０．５〜３５．０ｍｇＫＯＨ／ｇ持つものであるが、これに限定されるものではない。。ＡＶは、好ましくは０．５〜２５．０ｍｇＫＯＨ／ｇのものである。
【００５７】
連続加圧重合法については、特開平１−１５，７５１号公報の特許請求の範囲及び実施例に開示されている技術により製造することが出来る。具体的には、同公報に開示したように、エチレン系単量体、重合開始剤および溶媒を１９０〜２３０℃の系中に連続的に供給し、液状下で重合させるものである。
【００５８】
エチレン系単量体とキシレンおよび／またはエチルベンゼンの混合溶媒と重合開始剤を均一に溶解混合せしめた溶液を、予め該混合溶媒にて満液として温度１９０〜２３０℃に加熱された耐圧反応器内に内圧を一定に保持しつつ連続的に供給して１段または多段で重合を行う。ここで内圧を一定に保持するために重合液排出口には付近の温度は重合温度を保持するか、または溶媒の沸点以下の比較的低温まで急激に若しくは緩やかに冷却しても良く、重合温度を保持した場合は連続的に減圧下で溶媒を留去して該重合体と該混合溶媒を分離して、固形の重合体を得ることが出来、冷却した場合は該重合体が該混合溶媒に溶解された溶液として得ることが出来る。連続的に重合を行う際の反応器内の平均滞留時間は２〜２０時間で、エチレン系単量体、混合溶媒、重合触媒の混合物の供給速度と反応器内の実効容積によって決定され、エチレン系単量体の重合率が８０％以上、好ましくは９０％以上になるような条件を選択することが出来る。
【００５９】
重合体（Ｌ）の物性値については、電子写真トナーとしたときの定着性および保存性を保つために上記の範囲であることが望ましい。
【００６０】
Ｍｗが３千よりも小さいと、トナーの製造が過粉砕となり収量が低下し好ましくなく、５万より大きいと、定着性を阻害し好ましくない。
【００６１】
ＡＶ（酸価）については、０．５〜３５．０ｍｇＫＯＨ／ｇであり、０．５ｍｇＫＯＨ／ｇよりも大きいと、帯電が十分で画像がカブリがなく、３５．０ｍｇＫＯＨ／ｇより小さければ、トナーが飛散にくく好ましい。
【００６２】
また、本発明の電子写真トナー用樹脂組成物は重合体（Ｈ）と（Ｌ）の混合物であり、その割合としては両樹脂の合計に対して（Ｌ）が１０〜９０重量％、好ましくは１５〜８０重量％、特に好ましくは２０重量％以上で６０重量％未満の範囲である。
【００６３】
二つの重合体の混合割合については、重量比で１０：９０〜９０：１０であり、重合体（Ｈ）の割合が１０重量部より少ない場合には、溶融粘度が低くなりオフセットが発生し好ましくない。また、９０重量部より多いと、溶融粘度が高く成り過ぎ、定着時のエネルギーが増大し好ましくない。
【００６４】
両樹脂の混合方法としては、両樹脂の溶液から脱溶剤する方法が好ましく、例えばスプレー乾燥、特に残留揮発分を低くできる点で薄膜蒸発法によって行うことがこのましい。薄い膜蒸発方法は通常樹脂溶液から溶媒を除去する公知の方法が使用できる。
【００６５】
これは、重合体（Ｈ）および（Ｌ）を溶液状態で、予め混合する工程があるためであり、粉体混合より更に好ましく両重合体を混合することができ、そして減圧度、減圧時の温度および減圧工程の最適化により、樹脂およびそれを用いたトナーの残存揮発分量を減らすことも出来る。
【００６６】
本発明においては、重合体（Ｈ）および（Ｌ）の混合樹脂系についての条件を満たしていれば、その他にＨ１、Ｈ２またはＬとしてポリエステル樹脂（ウレタン変性ポリエステル樹脂）を含む）、スチレン系樹脂および／またはスチレン（メタ）アクリル酸エステル共重合樹脂とポリエステル樹脂の共重合体をも、本発明の効果を阻害しない範囲において併用することが出来る。
【００６７】
本発明における重合体（Ｈ）および（Ｌ）の混合樹脂のトナー組成物中の量は、通常５０〜９５重量部である。また、結着樹脂には必要に応じて本発明の効果を阻害しない範囲において、例えばポリ塩化ビニル樹脂、ポリオレフィン樹脂、ポリエステル樹脂、ポリビニルブチラール、ポリウレタン樹脂、ポリアミド樹脂、ロジン、テルペン樹脂、フェノール樹脂、エポキシ樹脂、パラフィンワックスなどを添加してもよい。
【００６８】
更に、近年の高速複写に伴い定着時に用いられる定着用ヒーターの熱量は低下しており、トナーのＴｇを低減などだけによる低温定着効果だけでは不充分で、更なるシャープメルト性を保持した低温定着性能が求められている。
【００６９】
本発明のトナーには、トナーに使用される通常着色剤を使用する。
本発明に好ましく用いられる着色剤としては，顔料または染料を挙げることができ，例えば種々のカーボンブラック，ニグロシン染料（Ｃ．Ｉ．Ｎｏ． ５０４１５），アニリンブルー（Ｃ．Ｉ．Ｎｏ． ５０４０５），カルコオイルブルー（Ｃ．Ｉ．Ｎｏ．ａｚｏｅｃ Ｂｌｕｅ ３），クロームイエロー（Ｃ．Ｉ．Ｎｏ． １４０９０），ウルトラマリンブルー（Ｃ．Ｉ．Ｎｏ． ７７１０３），デュポンオイルレッド（Ｃ．Ｉ．Ｎｏ． ２６１０５），オリエントオイルレッド＃３３０（Ｃ．Ｉ．Ｎｏ． ６０５０５），キノリンイエロー（Ｃ．Ｉ．Ｎｏ． ４７００５），メチレンブルークロライド（Ｃ．Ｉ．Ｎｏ． ５２０１５），フタロシアニンブルー（Ｃ．Ｉ．Ｎｏ． ７４１６０），マラカイトグリーンオクサレート（Ｃ．Ｉ．Ｎｏ． ４２０００），ランブブラック（Ｃ．Ｉ．Ｎｏ． ７７２６６），ローズベンガル（Ｃ．Ｉ．Ｎｏ． ４５４３５），オイルブラック，アゾオイルブラックなどを単独であるいはこれらを混合して用いることができる。これら着色剤は任意の量を用いることができるが，必要な濃度を得るためと経済的な理由のために，トナー中に約１〜３０重量％，好ましくは５〜１５重量％になるような割合で使用される。
【００７０】
顔料あるいは染料としては，重合反応系中もしくは本発明のトナー中への分散性を増加させる目的で種々の処理を施したものを使用してもよい。前記処理としては，例えばニグロシン染料（Ｃ．Ｉ．Ｎｏ． ５０４１５）をステアリン酸、マレイン酸の如き有機酸を用いての処理がある。
【００７１】
これら着色剤の中で，本発明のトナーに特に好ましいのは種々のカーボンブラック，例えば，ファーネスブラック，チヤンネルブラック，サーマルブラック，アセチレンブラック，ランプブラックなどである。さらに前記カーボンブラックは表面処理を施されていてもよい。表面処理としては，例えば酸素，オゾン，硝酸など種々の酸化剤を用いての酸化処理，ジブチルフタレート，ジオクチルフタレートなどの有機酸エステルによる表面吸着処理などがある。
【００７２】
着色剤として，カーボンブラックを使用するときは，グラフト化カーボンブラックを使用することも好ましい。
グラフト化カーボンブラックとは，カーボンブラックの存在下に，Ｈ１、Ｈ２及びＬで使用される重合性単量体を塊状重合，溶液重合等の方法により重合させて得られるものである。グラフト化カーボンブラックの重合体成分は，グラフト化カーボンブラックに対して３重量％以上、好ましくは５重量％以上で、且つ５０重量％以下が好ましく，特に３０重量％以下が好ましい。
【００７３】
グラフト化カーボンブラックは，乳化重合に際し、その分散安定性が優れるので好ましいが，重合体成分が多すぎると重合性単量体に分散させたとき粘度が高くなりすぎる傾向があり，作業性が低下する。グラフト化カーボンブラックの使用量は，カーボンブラック成分量で決定するのが好ましい。
【００７４】
しかしながら、本発明においては更に好ましくは、カーボンブラック１００ｇが吸収することができるジブチルフタレート（以下、ＤＢＰと記す）の量で、カーボンブラック（以下、ＣＢと記す）の分散性を表す。これは吸油量と言われるものであり、本発明においては、この吸油量が３０．０〜１１０．０ｍｌＤＢＰ／１００ｇ、好ましくは４５．０〜８５．０ｍｌＤＢＰ／１００ｇで、且つｐＨが２．０〜６．５、好ましくは３．０〜５．５であるＣＢとトナー１００重量部中に３〜１５重量部、好ましくは５〜１０重量部含有させることが好ましい。
【００７５】
吸油量が３０．０ｍｌＤＢＰ／１００ｇよりも大きなＣＢを用いた場合には、導電性が十分で、トナー飛散しにくく好ましい。また、１１０．０ｍｌＤＢＰ／１００ｇよりも小さければ、トナーの漏電量が少なく、トナーの帯電量を最適化するためには多量の帯電調整剤（ＣＣＡ）を必要とせず、トナーのコスト低下および機内汚染が発生がしにくく好ましい。
【００７６】
また、カーボンのｐＨについては２．０より大きいものの場合、結着樹脂との分散が好ましく、６．５より小さければ帯電量が適正化できる。
【００７７】
本発明の電子写真トナー用樹脂組成物を使ったトナーには、低軟化点化合物を含有することが更に好ましい。
【００７８】
詳しく述べるならば環球法で測定した軟化点が４０〜１３０ ℃、好ましくは５０〜１２０ ℃を有するものである。軟化点が４０℃未満ではトナーの耐ブロッキング性が不充分であり、１３０ ℃を超える場合は定着温度を低下させる効果が少ない。
具体的には、パラフィン、低分子量ポリオレフィン（未変性ポリオレフィンワックスまたはオレフィン成分に対して変性成分がブロック化またはグラフト化された変性ポリオレフィンワックスのいずれであってもよい）、芳香族基を有する変性ワックス、脂環基を有する炭化水素化合物、天然ワックス、炭素数１２以上の長鎖炭化水素鎖を有する長鎖カルボン酸、そのエステル等であり、現在入手可能なものとしては、パラフィンワックス（日本石油製）、パラフィンワックス（日本精蝋製）、マイクロワックス（日本石油製）、マイクロクリスタリンワックス（日本精蝋製）、硬質パラフィンワックス（日本精蝋製）、ＰＥ−１３０（ヘキスト製）、三井ハイワックス１１０Ｐ（三井石油化学製）、三井ハイワックス２２０Ｐ（三井石油化学製）、三井ハイワックス６６０Ｐ（三井石油化学製）、三井ハイワックス２１０Ｐ（三井石油化学製）、三井ハイワックス３２０Ｐ（三井石油化学製）、三井ハイワックス４１０Ｐ（三井石油化学製）、三井ハイワックス４２０Ｐ（三井石油化学製）、ハイレッツＴ−１００Ｘ（三井石油化学製）、ハイレッツＴ−２００Ｘ（三井石油化学製）、ハイレッツＴ−３００Ｘ（三井石油化学製）；ペトロジン８０（三井石油化学製）、ペトロジン１００ （三井石油化学製）、ペトロジン１２０ （三井石油化学製）、タックエースＡ−１００ （三井石油化学製）、タックエースＦ−１００ （三井石油化学製）、タックエースＢ−６０（三井石油化学製）、変性ワックスＪＣ−１１４１ （三井石油化学製）、変性ワックスＪＣ−２１３０ （三井石油化学製）、変性ワックスＪＣ−４０２０ （三井石油化学製）、変性ワックスＪＣ−１１４２ （三井石油化学製）、変性ワックスＪＣ−５０２０ （三井石油化学製）；密ロウ、カルナバワックス、モンタンワックス等を挙げることができるが、これに限定されるものではない。
【００７９】
更に、一般に使用されているポリオレフィンワックスを併用することも可能であり、「ビスコール６６０Ｐ」、「ビスコール５５０Ｐ」（以上、三洋化成製）、「ポリエチレン６Ａ」（アライドケミカル社製）、「ハイワックス４００Ｐ」、「ハイワックス１００Ｐ」、ハイワックス１０５Ｐ」、「ハイワックス３２０Ｐ」、「ハイワックス５５０Ｐ」（以上、三井石油化学社製）、「ヘキストワックスＰＥ５２０」、「ヘキストワックスＰＥ１３０」、「ヘキストワックスＰＥ１９０」（以上、ヘキストジャパン製）などの市販されているものの他、例えばメタアクリル酸メチルによりブロック共重合またはグラフト共重合せしめたポリエチレンワックス、スチレンなどによりブロック共重合またはグラフト共重合せしめたポリエチレンワックスなどを使用しても良い。
【００８０】
また、その添加量としては電子写真トナーの総量中に１〜５０重量％、好ましくは５〜３０重量％とすることが望ましい。
【００８１】
これらのポリオレフィンワックスは、通常は電子写真トナーの製造の溶融混練工程で結着樹脂と混合するが、重合体（Ｈ）の重合またはエチレン系重合体（Ｈ）および（Ｌ）の混合脱溶剤時に添加してもよい。
【００８２】
電子写真トナーには、流動性向上剤，クリーニング性向上剤などを必要に応じて用いることができる。これらは，通常製品トナーに後に外添処理される。これらの含有量としては本発明のトナーに対して各々０重量％〜３重量％が好ましい。流動性向上剤には，シラン，チタン，アルミニウム，カルシウム，マグネシウムおよびマグネシウムの酸化物もしくは前記酸化物をチタンカップリング剤あるいはシランカップリング剤で疎水化処理したものがあり，クリーニング性向上剤には，ステアリン酸亜鉛，ステアリン酸チリウムおよびラウリル酸マグネシウムの如き高級脂肪酸の金属塩あるいはペンタエリスリトールベンゾエートの如き芳香族酸エステルがあるが、これに限定されるものでない。
【００８３】
本発明においては、帯電量および帯電極性をより所望の値に調整するために本発明のトナーに所謂荷電制御剤を前記着色剤と併用して用いることもできる。
本発明に好ましく用いられる荷電制御剤としては，例えばスピロンブラックＴＲＨ，スピロンブラックＴＰＨ（保土谷化学）などのアゾ染料，例えばｐ−フルオロ安息香酸，ｐ−ニトロ安息香酸，２，４ −ジ−ｔ−ブチルサルチル酸などの芳香族酸誘導体，例えばジブチル−スズオキシド，ジオクチル−スズオキシドなどのスズ化合物などを挙げることができる。これらは，重合性単量体に対して０〜５重量％使用されるのが好ましい。
【００８４】
電子写真トナーの製造方法としては、結着樹脂、各種添加剤をヘンシェルミキサーでプレミクスした後、ニーダーなどの混練機で加熱溶融混練し、冷却後ジェット粉砕機を用いて微粉砕した後、分級機で分級し、通常８から２０μｍの範囲の粒子を集めて電子写真トナーとしても良いし、結着樹脂の製造行程でトナーに添加される各種成分を均一に分散させることにより得られる、通常重合トナーと呼ばれるものであっても良い。
【００８５】
磁性トナーとするために、磁性粉を含有させても良く、これは着色剤を兼ねることができる。好ましい磁性粉としては，例えばマグネタイトあるいはフェライトの如き鉄あるいはニッケル、コバルトなどの強磁性を示す元素の酸化物もしくは化合物がある。これら磁性粉は粒径が０．０１〜３μｍの粉末状のものが好ましく、また磁性粉の表面が樹脂，チタンカップリング剤，シランカップリング剤，高級脂肪酸金属塩などで処理されていてもよい。これら磁性体はトナーに対して１５〜８０重量％，好ましくは３５〜７０重量％を含有させることができる。これ以下の量で，着色剤として使用してもよい。
【００８６】
本発明により得られるトナーは種々の現像プロセス，例えば米国特許第２，６１８，５５２ 号に記載されているカスケード現像法，米国特許第２，８７４，０６５ 号に記載されている磁気ブラシ法，米国特許第２，２２１，７７６ 号に記載されているパウダー・クラウド法，米国特許第３，１６６，４３２ 号に記載のタッチダウン現像法，特開昭５５−１８６５６号公報に記載されている所謂ジャンピング法、キャリアとして粉砕法によつて製造された磁性トナーを用いる所謂マイクロトーニング法，磁性トナー同士の摩擦帯電によつて必要なトナー電荷を得る所謂バイポーラー・マグネチックトナー法などに用いることができるが、これに限定されるものではない。
【００８７】
また，本発明により得られるトナーは種々の定着方法，例えば所謂オイルレスおよびオイル塗布ヒートロール法，フラッシュ法，オーブン法，圧力定着法などに用いることができる。
更に、本発明のトナーは，種々のクリーニング方法，例えば，所謂ファーブラシ法、ブレード法などに用いることができる。
【００８８】
【実施例】
以下、実施例により本発明を更に詳細に説明するが、本発明はこれらの実施例により限定されるものではない。なお、以降「部」は、特に断わらない限り重量部を表す。
【００８９】
１．エチレン系重合体（Ｌ）の重合例
製造例（Ｌ−１）；実施製造例
スチレン単量体８２．０部、ｎ−ブチルアクリレート１５．０部、メタクリル酸３．０部、キシレンとエチルベンゼンからなる混合溶媒３０部に単量体１００部当たり０．５部のジ−ｔ−ブチルパ−オキサイドを均一に溶解したものを、反応器内温１９０℃、内圧６ｋｇｆ／ｃｍ２、排出口温度１００℃の条件を保持しながら、７５０ｃｃ／ｈｒで連続的に供給して重合体（Ｌ−１）を得た。
【００９０】
得られたスチレン重合体の重合率は重量で９９．５％であり、その分子量を単分散標準ポリスチレンを標準サンプルとしたゲルパーミネーションクロマトグラフィー（以下、ＧＰＣと記す）を用いてテトラハイドロフラン（以下、ＴＨＦと記す）を溶離液として測定したところＭｗは、５３００、酸価１．５ｍｇＫＯＨ／ｇ、Ｔｇは５９℃であった。
【００９１】
重合体の分子量の測定
重合体の分子量の測定は、市販の単分散標準ポリスチレンを標準とし、溶媒とＴＨＦ、検出器に屈折率計を用いたＧＰＣにより求めた。
【００９２】
検出器 ； ＳＨＯＤＥＸ ＲＩ ＳＥ−３１
溶剤 ； テトラヒドロフラン
カラム ； Ａ−８０Ｍ ｘ ２ ＋ ＫＦ−８０２
流速 ； １．２ｍｌ／分
試料 ； ０．２５％ＴＨＦ溶液
【００９３】
製造例（Ｌ−２）；実施製造例
単量体組成をスチレン単量体５６．０部、ｎ−ブチルアクリレート１９．０部、メタクリル酸２５．０部とした以外は、製造例（Ｌ−１）と同様の方法により、Ｍｗ６０００、Ｔｇ５８℃、酸価２０．４ｍｇＫＯＨ／ｇの重合体（Ｌ−４）の溶液を得た。
【００９４】
製造例（Ｌ−３）；実施製造例
５Ｌ四つ口フラスコに、冷却管、温度計、窒素導入管と撹拌装置を付し、キシレン溶剤１００部を仕込み、窒素を導入しながら還流温度まで昇温し、スチレン単量体１００．０部とｔ−ブチルペルオキシ−２−エチルヘキサノエート１０．０部を７．５時間かけて連続滴下し、後重合１時間したあと残モノマー重合を行ってＭｗ４５００、Ｔｇ６２℃、酸価０．０ｍｇＫＯＨ／ｇの重合体（Ｌ−５）の溶液を得た。
【００９５】
２．エチレン系重合体（Ｈ）の重合例
製造例（ｈ−１）；実施製造例
５Ｌ四つ口フラスコに、冷却管、温度計、窒素導入管と撹拌装置を付し、スチレン単量体２８．０部、ｎ−ブチルアクリレート１２．０部を仕込み、内温９０℃に昇温後、同温度に保ち、塊状重合を１６時間行った。次いで、キシレン７０部とジビニルベンゼン０．３部を加え、予め混合溶解しておいたジ−ｔ−ブチルパーオキシド０．３部、キシレン３０部、ジビニルベンゼン０．１部、スチレン単量体４５．０部とｎ−ブチルアクリレート１５．０部を１２５℃に保ちながら８．１時間かけて連続滴下し、その後２時間反応を継続し、残モノマー重合を終了し重合体（ｈ−１）を得た。
【００９６】
重合体（ｈ−２）〜（ｈ−１０）についても、表２、３に示した製造条件で重合体（ｈ−１）と同様にして得た。
【００９７】
【表２】

【００９８】
【表３】

【００９９】
重合体（ｈ−１１）の製造例；比較製造例
５Ｌ四つ口フラスコに、冷却管、温度計、窒素導入管と撹拌装置を付し、スチレン単量体６８．０部、ｎ−ブチルアクリレート３２．０部を仕込み、内温１００℃に昇温後、同温度に保ち、塊状重合を９時間行った。次いで、キシレン７０部とジビニルベンゼン０．３部を加え、予め混合溶解しておいたジ−ｔ−ブチルパーオキシド０．３部、キシレン３０部、ジビニルベンゼン０．１部を１２５℃に保ちながら９．０時間かけて連続滴下し、その後１時間反応を継続し、残モノマー重合を終了し、Ｍｗ７８万でＴｇ４３℃の重合体（ｈ−１１）を得た。
【０１００】
重合体（ｈ−１２）の製造例；比較製造例
５Ｌ四つ口フラスコに、冷却管、温度計、窒素導入管と撹拌装置を付し、スチレン単量体６８．０部、ｎ−ブチルアクリレート３２．０部を仕込み、内温１２０℃に昇温後、同温度に保ち、塊状重合を５時間行った。次いで、キシレン７０部を加え、予め混合溶解しておいたジ−ｔ−ブチルパーオキシド０．３部、キシレン３０部を１３５℃に保ちながら９．０時間かけて連続滴下し、その後１時間反応を継続し、残モノマー重合を終了し、Ｍｗ１６万でＴｇ５１℃の重合体（ｈ−１２）を得た。
【０１０１】
（１）重合体の酸価（ＡＶ）の測定法
中和したキシレン／ｎ−ブタノール（１：１）混合溶剤に精秤した試料を溶解し、予め標定された１／１０Ｎ−水酸化ナトリウムのアルコール溶液で滴定し、その中和量から次式により算定した（単位はｍｇＫＯＨ／ｇ）。
【０１０２】
（２）電子写真トナーの製造法
Ｈ及びＬよりなる樹脂を表５記載の割合で混合された樹脂溶液を薄膜蒸発器で溶媒を蒸発して結着樹脂を得た。
結着樹脂１００重量部、離型剤（ハイワックス１０５Ｐ）６％、カーボンブラックをヘンシェルミキサーで前混合した後、二軸混練機にて溶融混合し、粗、微粉砕、分級して５．０〜１５．０μｍの粒子を得、これに外添処理（アエロジルＲ９７２、０．５％）を行ってトナーを得た。
【０１０３】
また、使用したカーボンブラック（ＣＢ）の物性を表４に、トナー組成を表５に示す。
【０１０４】
【表４】

【０１０５】
【表５】

トナー２２の製造例；比較例４用
エチレン系重合体（Ｌ−１）およびエチレン系重合体（ｈ−５）を別々に脱溶剤により固化し、それぞれ６５部、３５部とカーボンブラック Ｃを６．０部、その他は他のトナーと同様の物質および配合比と製造法により、トナー２２を得た。
【０１０６】
トナー２３の製造例；比較例５用
エチレン系重合体（Ｌ−１）、エチレン系重合体（ｈ−１１）および（ｈ−１２）を別々に脱溶剤により固化し、それぞれ６５部、２５部、１０部とカーボンブラック Ｃを６．０部、その他は他のトナーと同様の組成と製造法により、トナー２３を得た。
【０１０７】
（３）定着および高温オフセット性の評価
市販の卓上複写機を改造し、熱ローラーの温度（℃）と回転速度（ｍｍ／ｓ）をそれぞれ設定できるようにした試験機を使って実験した。
定着性の評価；熱ローラーの回転速度を４００ｍｍ／ｓに固定して、温度を様々変化させて、定着させたＩＤ １．０の画像を学振式摩耗試験機（荷重１．０ｋｇ）で擦り、その後のＩＤを測定して、それらの比をとって定着率を求め、定着率が７０％を越える最低のロール温度で評価した。
高温オフセット性の評価；熱ローラーの回転速度を４００ｍｍ／ｓに固定して、温度を様々変化させて高温オフセットする温度で示した。
【０１０８】
（４）ブロッキング性の評価
電子写真トナー１０００ｍｇをポリ瓶に入れタッピングし、５０℃で１６時間保持したあと室温に戻して、パウダーテスター（ホソカワミクロン製）にて振動し、篩上に残存したトナーの量により評価した。
【０１０９】
（５）画像品質；
上記トナーを用い、転写材としてＡ４サイズの普通紙を用いて２０，０００枚画出し耐久テストを行った。そこで、画像濃度、カブリ、フィルミングなどの有無によって評価した。評価結果を表６に示す。
【０１１０】
【表６】

【０１１１】
【発明の効果】
上記した本発明の電子写真トナーを用いることにより、従来技術では解決できなかった定着／オフセット／ブロッキング性のバランスに優れたものを得ることが出来た。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a resin composition for an electrophotographic toner used for a copying machine, a printer, a facsimile and the like using an electrophotographic method, and a toner composition containing the resin composition.
[0002]
[Prior art]
For toner installed in copiers and printers, it is possible to fix at higher speeds by shortening the fixing time due to the increase in copying speed and reducing the temperature of the fixing roller due to the demand for reducing power consumption. In order to enable fixing at a low temperature, attempts have been made to improve the fixability of toner used in a hot roll fixing method. In order to achieve this object, conventionally, the softening temperature of the toner has been lowered by lowering the molecular weight of the binder resin and lowering the glass transition temperature.
[0003]
However, lowering the molecular weight of the binder resin lowers the softening temperature, but also lowers the melt viscosity. At the same time, a fixing roller that does not apply a large amount of silicone oil causes a new problem such as an offset phenomenon to the fixing roller. Has occurred.
[0004]
In order to prevent this, a method has been adopted in which a high-molecular-weight polymer having a high melt viscosity is mixed and the melt viscosity is maintained so that no offset occurs. Alternatively, a method has been adopted in which silicone oil or wax is mixed to reduce the melt viscosity and maintain releasability.
[0005]
JP-A-7-140,708 and JP-A-7-181,730 disclose that the glass transition temperature (hereinafter, referred to as Tg) of a high molecular weight component is 0 ° C or less and the Tg of a low molecular weight component is 50 ° C or more. A technique for improving the thermophysical properties of the toner is disclosed, however, setting the Tg of the high molecular weight component to 0 ° C. or lower is not preferable because the blocking property is deteriorated.
[0006]
Japanese Patent Application Laid-Open No. Sho 60-7,434 (Hitachi Chemical) discloses a technique for producing a toner by mixing three types of polymers (each having a different Mw and Tg). According to this method, in a heat and pressure fixing system such as a heat roller, a toner having excellent offset resistance, low-temperature fixing, and a good balance of blocking resistance, stress resistance in a developing machine, and the like cannot be obtained.
[0007]
Generally, toner undergoes a mechanical frictional force due to a shearing force and an impact force received during a mechanical operation in a developing device, and deteriorates during copying of several thousand to tens of thousands of sheets. To increase. To prevent such deterioration of the toner, a tough resin having a large molecular weight that can withstand mechanical frictional force may be used. However, these resins generally have a high softening temperature, and are non-contact fixing methods such as oven fixing and infrared fixing. In the radiant fixing method, fixing is not performed sufficiently due to poor thermal efficiency.Also, in a heat pressure fixing method using a heat roller which is widely used due to good heat efficiency in a contact fixing method, a heat roller is used for sufficient fixing. It is necessary to increase the temperature, which causes not only adverse effects such as deterioration of the fixing device, curling of the paper, and increase in energy consumption, but also the use of such a resin causes poor pulverization. Efficiency drops significantly. Therefore, it is not possible to use a binder resin having a very high degree of polymerization and a very high softening temperature.
[0008]
On the other hand, the thermal pressure fixing method using a heat roller has a remarkably good thermal efficiency because the surface of the heat roller and the toner image surface of the sheet to be fixed come into pressure contact, and is widely used from a low speed to a high speed. When the image surfaces come into contact with each other, a so-called offset phenomenon in which the toner adheres to the surface of the heating roller and is transferred to the subsequent transfer paper or the like is likely to occur. In order to prevent this phenomenon, the surface of the heating roller is processed with a material having excellent releasability such as a fluorine-based resin, and the surface of the heating roller is further treated by applying a releasing agent such as silicone oil. However, the method of applying a silicone oil or the like is not preferable because not only the size of the fixing device becomes large and the cost becomes high, but also the system becomes complicated, which easily causes a trouble.
[0009]
Further, as disclosed in JP-A-50-44836, JP-A-57-37353, and JP-B-57-493, the offset phenomenon is improved by making the resin asymmetric or crosslinked. There is a method, but no improvement has been made in terms of fixability.
[0010]
In general, the minimum fixing temperature is between the low-temperature offset and the high-temperature offset, so the usable temperature range is between the minimum fixing temperature and the high-temperature offset. The usable fixing temperature can be lowered and the usable temperature range can be expanded, so that energy saving, high-speed fixing, and prevention of paper curl can be achieved. For this reason, there is a demand for a toner that always has good fixability and anti-offset properties.
[0011]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and has as its object, in a heat and pressure fixing system such as a heat roller, excellent anti-offset properties, low-temperature fusing, further anti-blocking properties, and anti-resistance in a developing machine. An object of the present invention is to provide a resin for electrophotographic toner and a toner excellent in stress property.
[0012]
[Means for Solving the Problems]
The present inventors have made intensive studies to solve the above problems, and as a result, have completed the present invention. That is, the present invention includes the following.
[0013]
{Circle around (1)} In an electrophotographic toner composition containing a binder resin composition, a colorant and a release agent as essential components, the binder resin composition contains an ethylene polymer component having a large weight average molecular weight (Mw) as shown below. H: the same applies hereinafter) to two types (the polymer component (H1) and the polymer component (H2): the same applies hereinafter) and an ethylene polymer having a small weight average molecular weight (Mw) (the polymer component (L) and The same applies hereinafter)), the weight ratio of the polymer component (H2) to the polymer component (H1) is 0.5 to 15.0, and the ethylene-based polymer (H) and the polymer component A resin composition for an electrophotographic toner, wherein the weight ratio of (L) is from 10:90 to 90:10.
Polymer component (H1): the weight average molecular weight (Mw) is 200,000 to 800,000, and the glass transition temperature (Tg1) is 45 to 55 ° C.
Polymer component (H2): a polymer component having a weight average molecular weight (Mw) of 50,000 to 400,000 and a glass transition temperature (Tg2) of 50 to 65 ° C.
(However, the weight average molecular weight of H1 is larger than the weight average molecular weight of H2)
Polymer component (L): Weight average molecular weight (Mw) is 3,000 to 50,000, and glass transition temperature (Tg3) is 40 to 80 ° C.
[0014]
(2) The resin composition for an electrophotographic toner according to (1), wherein the polymer component (H1) has a Mw of 400,000 to 800,000 and a Tg1 of more than 50 and 55 ° C. or less.
[0015]
(3) The resin composition for an electrophotographic toner according to (1) or (2), which is obtained by removing a solvent from a solution containing the polymer component H1, the polymer component H2, and the polymer component L. .
[0016]
(4) A toner composition containing the resin composition according to any one of (1) to (3).
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
The resin composition for an electrophotographic toner and the toner composition according to the present invention comprise, as essential components, a binder resin comprising three or more polymer compositions having different Mw, and a colorant and a release agent. Wherein the ethylene polymer (H) having a large Mw constituting the binder resin comprises the following polymer component (H1) and polymer component (H2), and the polymer component (H1) is based on the polymer component (H1). H2) contains an ethylene polymer (L) having a weight ratio of 0.5 to 15.0 and Mw of 3,000 to 50,000, and the polymer (H) and the polymer (L) Is a weight ratio of 10:90 to 90:10, and is made of a resin composition for an electrophotographic toner manufactured by containing both ethylene polymers.
[0018]
Polymer component (H1) Polymer component having Mw of 200,000 to 800,000 and Tg1 of 45 to 55 ° C
Polymer component (H2) A polymer component having Mw of 50,000 to 400,000 and Tg2 of 50 to 65 ° C. (However, the weight average molecular weight of H1 is larger than the weight average molecular weight of H2)
Further, if added, the composition may contain 1 to 30% by weight, preferably 2 to 25% by weight, of a component (usually called a gel) which is higher than the exclusion limit in the molecular weight measurement.
[0019]
In the present invention, the component exceeding the exclusion limit refers to a component that becomes insoluble when a 2% by weight solution of all resin components is dissolved in tetrahydrofuran at 20 ° C.
[0020]
The ethylene polymer (H) of the present invention contains both the polymers (H1) and (H2) satisfying the conditions for the polymer components (H1) and (H2). This makes it possible to assign a distribution to Tg corresponding to the molecular weight distribution.
[0021]
More specifically, the Tg of the high molecular weight component is set lower to improve the fixing property, and the Tg of the low molecular weight component is set higher to improve the blocking property. And a resin composition for electrophotographic toner having an extremely excellent balance of the above was obtained.
[0022]
The conditions of Mw, Tg and the proportion of the components under the above conditions are necessary for balancing, and the electrophotographic toner using the polymer (H) out of these conditions is not preferable because the balance is lost. .
[0023]
The method of the present invention also includes a polymer component (L) having a weight average molecular weight (Mw) of 3,000 to 50,000 and a glass transition temperature (Tg3) of 40 to 80 ° C.
[0024]
In the method of the present invention, the ethylene monomer for obtaining each polymer component is not particularly limited as long as it is appropriately selected so as to give a predetermined glass transition temperature and is (co) polymerized. If there is, it can be adjusted enough.
[0025]
For example, L. E. FIG. Nielsen, Translated by Shigeharu Onoki, "Mechanical Properties of Polymers" (Tokyo Kagaku Dojin), pages 16 to 32, the glass transition temperature of an ethylene-based polymer, and page 26, a method for calculating the glass transition temperature of a copolymer. Are described, and an ethylene monomer can be selected with reference to these.
The glass transition temperature of the (co) polymer can be measured by a known method such as differential thermal analysis.
[0026]
The ethylenic monomer used to polymerize the ethylene polymer used in the method of the present invention can be commonly used to polymerize the H1, H2 and L polymer components used in the present invention. The glass transition temperature and molecular weight of each polymer component can be appropriately adjusted as specified in the present invention.
[0027]
Examples of the monomer include, but are not limited to, the following.
[0028]
Aromatic vinyl monomers such as styrene, α-methylstyrene, halogenated styrene, vinyltoluene, 4-sulfonamidostyrene, 4-styrenesulfonic acid and the like; acrylic acid ester monomers and methacrylic acid monomers such as Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate , Lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, furfuryl (meth) acrylate, hydroxylethyl (meth) acrylate , Hydroxybutyl (meth) acrylate, (meth) Dimethylaminomethyl acrylate, dimethylaminoethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-chloroethyl (meth) acrylate and the like; itaconic esters such as dimethyl itaconate, dipropyl itaconate; Dibutyl itaconate, dioctyl itaconate, diamyl itaconate and the like; maleic esters and fumaric esters, for example, maleic esters and fumaric esters having a linear or branched alkyl group having 1 to 8 carbon atoms, diethyl maleate, Dipropyl maleate, dibutyl maleate, dipentyl maleate, dihexyl maleate, heptyl maleate, octyl maleate, ethyl butyl maleate, ethyl octyl maleate, butyl octyl maleate, male Butylhexyl inmate, pentyl octyl maleate, diethyl fumarate, dipropyl fumarate, dibutyl fumarate, dipentyl fumarate, dihexyl fumarate, heptyl fumarate, octyl fumarate, ethyl butyl fumarate, ethyl octyl fumarate, butyl fumarate Octyl, butylhexyl fumarate, pentyl octyl fumarate and the like; unsaturated carboxylic acids and unsaturated dicarboxylic acids such as (meth) acrylic acid, cinnamic acid, maleic acid, fumaric acid, itaconic acid; and others, for example, 2-vinylnaphthalene, Examples of itaconic anhydride, maleic anhydride; acrylamide alkylsulfonic acid and / or methacrylamide acrylic sulfonic acid include acrylamide alkylsulfonic acid and / or methacrylamide And acrylamide methyl sulfonic acid, acrylamide ethyl sulfonic acid, acrylamide n-propyl sulfonic acid, acrylamide isopropyl sulfonic acid, acrylamide n-butyl sulfonic acid, acrylamide s-butyl sulfonic acid, and acrylamide t-butyl sulfonic acid. Acid, acrylamidopentanesulfonic acid, acrylamidohexanesulfonic acid, acrylamidoheptanesulfonic acid, acrylamidooctanesulfonic acid, methacrylamidomethylsulfonic acid, methacrylamidoethylsulfonic acid, methacrylamido n-propylsulfonic acid, methacrylamidoisopropylsulfonic acid, methacrylamide n-butylsulfonic acid, methacrylamide-s-butylsulfonic acid, methacrylate De t- butyl sulphonic acid, methacrylamide pentanesulfonic acid, methacrylamide hexanesulfonic acid, methacrylamide heptanesulfonic acid, such as methacrylamide octanesulfonic acid.
The ethylene-based monomer is not particularly limited, but a styrene-based monomer or a (meth) acrylate-based monomer is preferably used.
[0029]
In the method of the present invention, a polyfunctional monomer can be preferably used in addition to the ethylene monomer, as described later.
[0030]
Examples of the polyfunctional monomer include styrene-based monomers such as divinylbenzene, and examples of acryl-based polyfunctional monomers such as 1,3-butylene glycol diacrylate, 1,5-pentanediol diacrylate, Pentyl glycol diolate, 1,6-hexanediol diolate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, polyethylene glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, polypropylene Diacrylate, N, N'-methylenebisacrylamide, pentaerythritol triacrylate, trimethylolpropane triacrylate, tetramethylo Examples of methacrylic polyfunctional monomers such as lepropane triacrylate and 1,4-butanediol diacrylate include, for example, diethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, and 1,5-pentanediol dimethacrylate. Acrylate, neopentyl glycol dimethacrylate, 1,6-hexanediol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polyethylene glycol # 400 Dimethacrylate, polyethylene glycol # 600 dimethacrylate, polypropylene dimethacrylate, N, N'-methylenebismethacrylamide, Examples include pentaeristol trimethacrylate, trimethylolpropane trimethacrylate, tetramethylolpropane trimethacrylate, 1,4-butanediol dimethacrylate, and 2,2-bis (4-methacryloxypolyethoxyphenyl) propane. However, the present invention is not limited to this.
[0031]
If desired, a polyfunctional monomer may be used as a monomer at this stage. The amount to be used is 0.0-15.0% by weight, preferably 0.1-10% by weight, more preferably 1-7% by weight, based on the total amount of the monomers constituting the polymer (H) of the present invention. %.
[0032]
The polymer (H) (resin containing at least the polymer components (H1) and (H2)) is produced by at least one of bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization, or a combination thereof. In view of this, in Table 1 below, the manufacturing method is preferred in the order from Pattern 1. Specifically, there are the following configurations, and particularly preferably the pattern 1 or 2.
[0033]
This is because the fixable area is wider than that obtained by another polymerization method. Although the reason is not clear, considering that the pulverizability of the resins produced by the two methods is greatly different, the resin produced by the pattern 1 or 2 has a more suitable entangled molecular chain structure, It is considered that both the fixing property at high temperature and the improvement of the high-temperature offset resistance in a high-temperature region are compatible.
[0034]
If the process cannot be obtained by using a polymer solution, in this case, the solvent is dissolved in an appropriate solvent and then the solvent is removed.
[0035]
Hereinafter, a method for producing the polymer (H) will be described in which the polymer component (H1) is produced in the polymerization stage 1 and the polymer component (H2) is produced in the polymerization stage 2. Table 1 shows an example of the manufacturing method.
[0036]
[Table 1]

In the above table, there is no problem in incorporating other necessary steps between each step of the polymerization.
[0037]
The pattern 1 is specifically described as follows, but the present invention is not limited to the following method.
(1) Bulk polymerization: An ethylene monomer and a polymerization initiator selected to have a predetermined Tg are charged into a polymerization system, and polymerization is performed at a system temperature of 90 to 120 ° C for 6 to 16 hours. At the end of the polymerization time of the bulk polymerization, the heat of polymerization is removed by adding a solvent, and the chain transfer is promoted to terminate the polymerization.
[0038]
As the polymerization initiator used when polymerizing the polymer used in the present invention, known polymerization initiators used in radical polymerization are used. For example, t-butyl peroxymethacrylate, t-butyl peroxycrotonate, di (t-butyl) Peroxy) fumarate, t-butylperoxyallyl carbonate, per-trimellitic acid tri-t-butyl ester, pertrimellitic acid tri-t-amino ester, pertrimellitic acid tri-t-hexyl ester, pertrimellitic acid tri- t-1,1,3,3-tetramethylbutyl ester, tri-t-cumyl pertrimellitic acid ester, tri-t- (p-isopropyl) cumyl pertrimellitic acid, tri-t-butyl pertrimesate Ester, pertrimesic acid tri-t-amino ester, pertrimesic acid tri-t- Sil ester, per-trimesic acid tri-t-1,1,3,3-tetramethylbutyl ester, pertrimesic acid tri-t-cumyl ester, pertrimesic acid tri-t- (p-isopropyl) cumyl ester, 2, 2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 2,2-bis (4,4-di-t-hexylperoxycyclohexyl) propane, 2,2-bis (4,4- Di-t-amylperoxycyclohexyl) propane, 2,2-bis (4,4-di-t-octylperoxycyclohexyl) propane, 2,2-bis (4,4-di-α-cumylperoxycyclohexyl) ) Propane, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) butane, 2,2-bis (4,4-di-t-octylperoxycyl) Clohexyl) butane.
[0039]
Isobutyryl peroxide, α, α'-bis (neodecanylperoxy) diisopropylbenzene, cumylperoxyneodecanate, di-n-propylperoxydicarbonate, diisopropylperoxydicarbonate, 1,1,3 , 3-Tetramethylbutylperoxyneodecanoate, bis (4-t-butylcyclohexyl) peroxydicarbonate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, di-2-ethoxyethylperoxydi Carbonate, di (2-ethylhexylperoxy) dicarbonate, 1-hexylperoxyneodecanoate, dimethoxybutylperoxydicarbonate, di (3-methyl-3-methoxybutylperoxy) dicarbonate, t-butylper Oxyneodeca Ethate, 2,4-dichlorobenzoyl peroxide, 1-hexylperoxypivalate, 1,1-bis (t-butylperoxy) cyclohexane, 2,2-bis (4,4-di-t-butylperoxy) Cyclohexenyl) propane, 1,1-bis (t-butylperoxy) cyclodecane, 1-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethyl Hexanoate, t-butylperoxylaurate, 2,5 dimethyl-2,5-di (m-toluoylperoxy) hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl Monocarbonate, 1-hexylperoxybenzoate, 2,5-di- Tyl-2,5-di (benzoylperoxy) hexane, t-butylperoxyacetate, 2,2-bis (t-butylperoxy) butane, t-butylperoxybenzoate, n-butyl-4,4- Bis (t-butylperoxy) valerate, t-butylperoxybivalate, 3,3,5-triethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, 1,1,3,3 -Tetramethylbutylperoxy-2-ethylhexanoate, succinic peroxide, 2,5-dimethyl-2,5-di (2-ethylhexanoylperoxy) hexane, 1-cyclohexyl-1-methylethylperoxide Oxy-2-ethylhexanoate, 1-hexylperoxy-2-ethylhexanoe DOO, t- butyl peroxy-2-ethylhexanoate, m- tolyl and benzoyl peroxide, benzoyl peroxide, t- butyl peroxy isobutyrate,
1,1-bis (1-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (1-hexylperoxy) cyclohexane, 1,1-bis (1-butylperoxy) -3 , 3,5-trimethylcyclohexane, di-t-butylperoxyisophthalate, α, α'-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (T-butylperoxy) hexane, t-butylcumyl peroxide, di-t-butyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane -3, diisopropylbenzene hydroperoxide, t-butyltrimethylsilyl peroxide, 1,1,3,3-tetrame Butyl hydroperoxide, cumene hydroperoxide, 1-hexyl hydroperoxide, t-butyl hydroperoxide, 2,3-dimethyl-2,3-diphenylbutane and the like. Two or more types can be used in combination.
[0040]
(2) Solution polymerization: A solvent such as toluene or xylene, a monomer in which the composition of a predetermined ethylene monomer is changed in order to adjust Tg, and a polymerization initiator are added to the system after the above-mentioned bulk polymerization is completed. The solution is continuously dropped at a temperature of 140 ° C. for 5 to 10 hours. More preferably, in the step of continuous dropping, by changing the composition of the dropped substance with time (gradient monomer feed), a particularly preferable ethylene-based polymer (H) can be obtained.
[0041]
(3) Post-polymerization: Thermal polymerization is carried out for 1 to 3 hours at the same temperature as the solution polymerization or at a temperature range of + 10 ° C.
[0042]
(4) Residual monomer polymerization: The polymerization is completed by adding an initiator at a temperature of 70 to 110 ° C so that the polymerization rate becomes 97 to 100%.
[0043]
In order to have a distribution in Tg, the composition of the ethylene monomer is changed in the polymerization step. For example, when a styrene monomer is used, the styrene monomer used in each step of bulk polymerization and solution polymerization is used. It is preferable to set the ratio to the ratio (at the time of bulk polymerization) <the ratio (at the time of solution polymerization).
[0044]
If desired, a polyfunctional monomer may be used as a monomer in the stages of (1) bulk polymerization and / or (2) solution polymerization. The amount to be used is 0.0-15.0% by weight, preferably 0.1-10% by weight, more preferably 1-7% by weight, based on the total amount of the monomers constituting the polymer (H) of the present invention. %.
[0045]
In the case of producing by a suspension polymerization method, the method is based on an aqueous medium containing a polymerizable monomer in an amount of 0.1 to 50% by weight of a suspension stabilizer (for example, a poorly soluble inorganic dispersant) (for example, (It is heated to a temperature of 5 ° C. or higher, preferably 10 ° C. or higher than the polymerization temperature) using a conventional stirrer, homomixer, homogenizer or the like. Thereafter, the liquid temperature of the aqueous medium is lowered to the polymerization temperature while stirring to such an extent that the particles are prevented from settling, so that the state is substantially maintained by the action of the dispersion stabilizer. The polymerization temperature is set to 50 ° C. or higher, preferably 55 to 80 ° C., particularly preferably 60 to 75 ° C., and a substantially water-insoluble polymerization initiator is added with stirring to carry out the polymerization.
[0046]
After completion of the reaction, the produced polymer is recovered and dried by an appropriate method such as washing, filtration, decantation, centrifugation and the like. In the suspension polymerization method, usually 200 to 3000 parts by weight of water is used as an aqueous dispersion medium with respect to 100 parts by weight of a polymerizable monomer.
[0047]
Also, suitable stabilizers such as polyvinyl alcohol, gelatin, methyl cellulose, methyl hydropropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, polyacrylic acid and salts thereof, starch, gum alginate, zein, casein, phosphoric acid Any one or a mixture of tricalcium, talc, barium sulfate, bentonite, aluminum hydroxide, ferric hydroxide, titanium hydroxide, sodium hydroxide, etc. in an aqueous medium to such an extent that the production method of the present invention is not adversely affected. May be used.
[0048]
Further, for uniform dispersion of the inorganic dispersant, a surfactant may be used to such an extent that the production method of the present invention is not adversely affected. This is to promote the desired action of the dispersion stabilizer, and specific examples thereof include sodium dodecylbenzenesulfonate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, and allyl-alkyl-poly. Sodium ether sulfonate, sodium oleate, sodium laurate, sodium caprate, sodium caprate, sodium caproate, potassium stearate, calcium oleate, 3,3-disulfonediphenylurea-4,4-diazo-bis-amino Sodium-8-naphthol-6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-disulfonic acid Na Helium, mention may be made of the other. In addition, water-soluble monomers simultaneously cause emulsion polymerization in water, and the resulting suspension polymer is contaminated with small emulsion polymerization particles.Therefore, a water-soluble polymerization inhibitor, such as a metal salt, is added to emulsify in the aqueous phase. It is also possible to prevent polymerization. Further, glycerin, glycol, or the like can be added to water in order to prevent the coalescence of particles at the time of polymerization more than the viscosity of the aqueous medium. In addition, NaCl, KCl, and Na are used to reduce the solubility of easily soluble monomers in water. ₂ SO ₄ It is also possible to add a Bronsted acid such as hydrochloric acid to the aqueous medium in order to increase the ionicity of the salts or polar groups.
[0049]
The polymerization initiator used is substantially insoluble in water and has a solubility of preferably 1 g or less in 100 g of water at room temperature, more preferably 0.5 g in 100 g of water. In particular, those having a low solubility of 0.2 g or less in 100 g of water are particularly preferred. It is preferable that the solubility of 1 g per 100 g of water is not more than 1 g because decomposition products of the polymerization initiator remaining on the surface of the polymer particles after completion of the polymerization do not lower the moisture resistance of the toner.
[0050]
The polymerization initiator to be used is soluble in the polymerizable monomer, and can be satisfactorily converted to the polymerizable monomer in the amount range usually used (2 to 5 parts by weight of the polymerization initiator with respect to 100 parts by weight of the monomer). It has the property of dissolving. Examples of the polymerization initiator usable in the present invention include 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, and 1,1'-azobis (cyclohexane-1). Azo- or diazo-based polymerization initiators such as -carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile and other azobisisobutyronitriles (AIBN); benzoyl peroxide, Peroxide polymerization initiators such as methyl ethyl ketone peroxide, isopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorylbenzoyl peroxide, and lauroyl peroxide are exemplified. In the production method of the present invention, the polymerization initiator preferably has a melting point equal to or different from the polymerization temperature (normally 50 ° C. or higher). It is also preferable to use a mixture of two or more polymerization initiators for the purpose of controlling the molecular weight and molecular weight distribution of the polymer or controlling the reaction time.
[0051]
In this case, it is preferable to use at least one having a melting point at a temperature corresponding to or lower than the liquid temperature in the aqueous medium at the time of polymerization. Because the polymerization initiator becomes oily at the liquid temperature during the polymerization reaction, the polymerization initiator or a radical generated from the polymerization initiator is added to each monomer composition particle dispersed after being added to the aqueous medium. This is because it is more appropriately applied. Incidentally, 2,2′-azobis- (2,4-dimethylvaleronitrile) used in the examples is a mixture of a meso form and a dl form, and the mixture starts melting at about 45 ° C. and about 70 ° C. Melting ends with. The amount of the polymerization initiator to be used is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the polymerizable monomer.
[0052]
The suspension polymerization reaction is usually performed at a polymerization temperature of 50 ° C. or higher, and the upper limit temperature is set in consideration of the decomposition rate of the polymerization initiator. If the set polymerization temperature is too high, the polymerization initiator is undesirably rapidly decomposed. In the present invention, the polymerization initiator does not need to be present in the monomer composition at the time of suspension granulation. Granulation can be easily performed by lowering the melt viscosity.
[0053]
After confirming that the formed monomer composition particles have a predetermined particle size, the liquid temperature of the aqueous medium containing the particles is lowered to the polymerization temperature (for example, 55 to 70 ° C.), and then the polymerization is started. Add the agent. By lowering the liquid temperature of the aqueous medium, the shape retention of the monomer composition particles is also improved, and coalescence of the particles is suppressed. The polymerization reaction time varies depending on the type of the polymerization initiator and the polymerization temperature, but is usually 2 to 30 hours.
[0054]
Regarding the polymerization method of the polymer (H), it is preferable to use a polyfunctional monomer regardless of the polymerization method of the pattern, which has an appropriate micro-crosslinked structure to the polymer (H). By giving the binder resin, the binder resin has appropriate strength, and further, by providing a part of the binder resin with an incompatible portion, it is possible to have melt fluidity and appropriate elasticity. The method for producing the ethylene polymer (H) of the present invention is not limited to the above.
[0055]
Next, the polymer (L) constituting the resin for an electrophotographic toner of the present invention has a Mw of 3,000 to 50,000, preferably 3,000 to 35,000, more preferably 3,000 to 3,000. 30,000, and Tg is 40 to 80 ° C, preferably 45 to 70 ° C.
[0056]
The polymerization component (L) is preferably produced by a continuous pressure polymerization method. Particularly preferably, as a structural unit of the polymer, the monomer described above may be converted from an acidic monomer (a monomer having a carboxyl group). Is selected, and has an acid value (hereinafter, referred to as AV) of 0.5 to 35.0 mgKOH / g, but is not limited thereto. . AV is preferably 0.5 to 25.0 mg KOH / g.
[0057]
The continuous pressure polymerization method can be produced by the technology disclosed in the claims and examples of JP-A No. 1-15,751. Specifically, as disclosed in the same gazette, an ethylene-based monomer, a polymerization initiator and a solvent are continuously supplied into a system at 190 to 230 ° C. and polymerized in a liquid state.
[0058]
A solution prepared by uniformly dissolving and mixing a mixed solvent of an ethylene-based monomer and xylene and / or ethylbenzene and a polymerization initiator is filled in advance with the mixed solvent in a pressure-resistant reactor heated to 190 to 230 ° C. The polymerization is carried out in one stage or in multiple stages by continuously supplying while keeping the internal pressure constant. Here, in order to keep the internal pressure constant, the temperature near the polymerization liquid outlet may be maintained at the polymerization temperature, or may be cooled rapidly or slowly to a relatively low temperature below the boiling point of the solvent. Is maintained, the solvent is continuously distilled off under reduced pressure to separate the polymer and the mixed solvent to obtain a solid polymer, and when cooled, the polymer is mixed with the mixed solvent. Can be obtained as a solution dissolved in The average residence time in the reactor during continuous polymerization is 2 to 20 hours, and is determined by the feed rate of the mixture of the ethylene monomer, the mixed solvent and the polymerization catalyst and the effective volume in the reactor, Conditions can be selected such that the polymerization rate of the system monomer is 80% or more, preferably 90% or more.
[0059]
The physical property value of the polymer (L) is desirably within the above range in order to maintain the fixability and the storability of the electrophotographic toner.
[0060]
If the Mw is smaller than 3,000, the production of the toner is excessively pulverized and the yield is reduced, and if it is larger than 50,000, the fixability is impaired, which is not preferable.
[0061]
The AV (acid value) is 0.5 to 35.0 mgKOH / g. If it is larger than 0.5 mgKOH / g, the toner is sufficiently charged and has no fog, and if it is smaller than 35.0 mgKOH / g, the toner is Is difficult to be scattered, and is preferable.
[0062]
The resin composition for an electrophotographic toner according to the present invention is a mixture of the polymers (H) and (L). 15 to 80% by weight, particularly preferably 20% by weight or more and less than 60% by weight.
[0063]
The mixing ratio of the two polymers is 10:90 to 90:10 in weight ratio, and when the ratio of the polymer (H) is less than 10 parts by weight, the melt viscosity becomes low and offset occurs, which is preferable. Absent. On the other hand, if it is more than 90 parts by weight, the melt viscosity becomes too high, and the energy at the time of fixing increases, which is not preferable.
[0064]
As a method of mixing the two resins, a method of removing the solvent from the solution of the two resins is preferable. For example, it is preferable to carry out the spray drying, particularly by the thin film evaporation method in that the residual volatile matter can be reduced. As the thin film evaporation method, a known method for removing a solvent from a resin solution can be generally used.
[0065]
This is because there is a step of preliminarily mixing the polymers (H) and (L) in a solution state, and it is possible to mix both polymers more preferably than powder mixing. By optimizing the temperature and the pressure reduction step, the amount of residual volatile components of the resin and the toner using the same can be reduced.
[0066]
In the present invention, a polyester resin (including a urethane-modified polyester resin) as H1, H2 or L, and a styrene-based resin, provided that the conditions for the mixed resin system of the polymers (H) and (L) are satisfied. And / or a copolymer of a styrene (meth) acrylate copolymer resin and a polyester resin can be used in combination as long as the effects of the present invention are not impaired.
[0067]
The amount of the mixed resin of the polymers (H) and (L) in the present invention in the toner composition is usually 50 to 95 parts by weight. Further, as long as the effect of the present invention is not impaired as necessary, for example, polyvinyl chloride resin, polyolefin resin, polyester resin, polyvinyl butyral, polyurethane resin, polyamide resin, rosin, terpene resin, phenol resin, Epoxy resin, paraffin wax and the like may be added.
[0068]
In addition, the amount of heat of the fixing heater used for fixing has been reduced due to recent high-speed copying, and the low-temperature fixing effect only by reducing the Tg of the toner is not sufficient, and the low-temperature fixing that further maintains the sharp melt property. Performance is required.
[0069]
For the toner of the present invention, a colorant usually used for a toner is used.
Examples of the coloring agent preferably used in the present invention include pigments and dyes, for example, various carbon blacks, nigrosine dyes (CI No. 50415), aniline blue (CI No. 50405), Calco Oil Blue (CI No. azoec Blue 3), Chrome Yellow (CI No. 14090), Ultramarine Blue (CI. No. 77103), DuPont Oil Red (CI. No. 77103). 26105), Orient Oil Red # 330 (CI No. 60505), Quinoline Yellow (CI. No. 47005), Methylene Blue Chloride (CI. No. 52015), Phthalocyanine Blue (CI. No. 52015). 74160), malachite green oxalate (CI No. 42) 00), Ranbu black (C.I.No. 77266), rose bengal (C.I.No. 45435), oil black, the azo oil black can be used singly or as a mixture thereof. These colorants can be used in any amount, but for the purpose of obtaining the required concentration and for economical reasons, the colorant is used in an amount of about 1 to 30% by weight, preferably 5 to 15% by weight in the toner. Used in proportions.
[0070]
As the pigment or dye, those subjected to various treatments for the purpose of increasing dispersibility in the polymerization reaction system or the toner of the present invention may be used. The treatment includes, for example, treatment of a nigrosine dye (CI No. 50415) with an organic acid such as stearic acid or maleic acid.
[0071]
Among these colorants, particularly preferred for the toner of the present invention are various carbon blacks such as furnace black, channel black, thermal black, acetylene black, lamp black and the like. Further, the carbon black may be subjected to a surface treatment. Examples of the surface treatment include an oxidation treatment using various oxidizing agents such as oxygen, ozone, and nitric acid, and a surface adsorption treatment with an organic acid ester such as dibutyl phthalate and dioctyl phthalate.
[0072]
When carbon black is used as the coloring agent, it is also preferable to use grafted carbon black.
The grafted carbon black is obtained by polymerizing the polymerizable monomers used in H1, H2 and L in the presence of carbon black by a method such as bulk polymerization or solution polymerization. The polymer component of the grafted carbon black is at least 3% by weight, preferably at least 5% by weight, and preferably at most 50% by weight, particularly preferably at most 30% by weight, based on the grafted carbon black.
[0073]
Grafted carbon black is preferred because of its excellent dispersion stability during emulsion polymerization, but if the amount of the polymer component is too large, the viscosity tends to be too high when dispersed in a polymerizable monomer, resulting in poor workability. I do. The amount of the grafted carbon black is preferably determined by the amount of the carbon black component.
[0074]
However, in the present invention, the dispersibility of carbon black (hereinafter, referred to as CB) is more preferably represented by the amount of dibutyl phthalate (hereinafter, referred to as DBP) that can be absorbed by 100 g of carbon black. This is called an oil absorption. In the present invention, the oil absorption is 30.0 to 110.0 ml DBP / 100 g, preferably 45.0 to 85.0 ml DBP / 100 g, and the pH is 2.0 to It is preferable that CB having a weight ratio of 6.5, preferably 3.0 to 5.5, and 3 to 15 parts by weight, preferably 5 to 10 parts by weight, are contained in 100 parts by weight of the toner.
[0075]
When CB having an oil absorption of more than 30.0 ml DBP / 100 g is used, the conductivity is sufficient and the toner is not easily scattered, which is preferable. On the other hand, if it is smaller than 110.0 ml DBP / 100 g, the amount of leakage of the toner is small, and a large amount of charge control agent (CCA) is not required for optimizing the charge amount of the toner. Is less likely to occur.
[0076]
When the pH of carbon is higher than 2.0, the dispersion with the binder resin is preferable, and when the pH is lower than 6.5, the charge amount can be optimized.
[0077]
It is more preferable that the toner using the resin composition for an electrophotographic toner of the present invention contains a low softening point compound.
[0078]
More specifically, it has a softening point measured by the ring and ball method of 40 to 130 ° C, preferably 50 to 120 ° C. If the softening point is less than 40 ° C, the blocking resistance of the toner is insufficient, and if it exceeds 130 ° C, the effect of lowering the fixing temperature is small.
Specifically, paraffin, low molecular weight polyolefin (which may be an unmodified polyolefin wax or a modified polyolefin wax in which a modified component is blocked or grafted to an olefin component), a modified wax having an aromatic group , A hydrocarbon compound having an alicyclic group, a natural wax, a long-chain carboxylic acid having a long-chain hydrocarbon chain having 12 or more carbon atoms, an ester thereof, and the like. ), Paraffin wax (manufactured by Nippon Seiwa), micro wax (manufactured by Nippon Oil), microcrystalline wax (manufactured by Nippon Seiwa), hard paraffin wax (manufactured by Nippon Seiwa), PE-130 (manufactured by Hoechst), Mitsui High Wax 110P (Mitsui Petrochemical), Mitsui High Wax 220P (Mitsui Petrochemical) Mitsui High Wax 660P (Mitsui Petrochemical), Mitsui High Wax 210P (Mitsui Petrochemical), Mitsui High Wax 320P (Mitsui Petrochemical), Mitsui High Wax 410P (Mitsui Petrochemical), Mitsui High Wax 420P (Mitsui Petrochemical), Heylets T-100X (Mitsui Petrochemical), Heylets T-200X (Mitsui Petrochemical), Heylets T-300X (Mitsui Petrochemical); Petrozine 80 (Mitsui Petrochemical), Petrozine 100 (Mitsui Petrochemical), Petrozine 120 (Mitsui Petrochemical), Tack Ace A-100 (Mitsui Petrochemical), Tack Ace F-100 (Mitsui Petrochemical), Tack Ace B-60 (Mitsui Oil) Modified wax JC-1141 (Mitsui Petrochemical), modified wax JC-2130 (Mitsui) Modified wax JC-4020 (Mitsui Petrochemical), Modified wax JC-1142 (Mitsui Petrochemical), Modified wax JC-5020 (Mitsui Petrochemical); beeswax, carnauba wax, montan wax, etc. However, the present invention is not limited to this.
[0079]
Further, commonly used polyolefin waxes can also be used in combination, such as “Viscol 660P”, “Viscol 550P” (manufactured by Sanyo Chemical), “Polyethylene 6A” (manufactured by Allied Chemical), and “High Wax 400P”. , "High Wax 100P", "High Wax 105P", "High Wax 320P", "High Wax 550P" (Mitsui Petrochemical Co., Ltd.), "Hoechst Wax PE520", "Hoechst Wax PE130", "Hoechst Wax PE190" (Hereinafter, manufactured by Hoechst Japan Co., Ltd.) and the like, as well as polyethylene wax obtained by block copolymerization or graft copolymerization with methacrylate and block copolymerization or graft copolymerization with methyl methacrylate. It may be used, such as box.
[0080]
It is desirable that the addition amount is 1 to 50% by weight, preferably 5 to 30% by weight based on the total amount of the electrophotographic toner.
[0081]
These polyolefin waxes are usually mixed with a binder resin in the melt-kneading step of the production of an electrophotographic toner, but when the polymer (H) is polymerized or the ethylene-based polymers (H) and (L) are mixed and desolvated. It may be added.
[0082]
In the electrophotographic toner, a fluidity improver, a cleaning property improver, and the like can be used as needed. These are usually externally added to the product toner later. The content of each of these is preferably 0% by weight to 3% by weight based on the toner of the present invention. Fluidity improvers include silane, titanium, aluminum, calcium, magnesium and magnesium oxides or those obtained by subjecting the oxides to a hydrophobic treatment with a titanium coupling agent or a silane coupling agent. Metal salts of higher fatty acids such as, but not limited to, zinc stearate, thylium stearate and magnesium laurate, or aromatic acid esters such as pentaerythritol benzoate.
[0083]
In the present invention, a so-called charge control agent can be used in combination with the colorant in the toner of the present invention in order to adjust the charge amount and the charge polarity to more desirable values.
Examples of the charge control agent preferably used in the present invention include azo dyes such as Spiron Black TRH and Spiron Black TPH (Hodogaya Chemical), for example, p-fluorobenzoic acid, p-nitrobenzoic acid, 2,4-di- Aromatic acid derivatives such as -t-butylsalicylic acid and the like, and tin compounds such as dibutyl-tin oxide and dioctyl-tin oxide can be exemplified. These are preferably used in an amount of 0 to 5% by weight based on the polymerizable monomer.
[0084]
As a method for producing an electrophotographic toner, a binder resin and various additives are premixed by a Henschel mixer, then heated and melted and kneaded by a kneader such as a kneader, cooled, finely pulverized by a jet pulverizer, and then classified by a classifier. The particles are usually classified into 8 to 20 μm, and may be used as an electrophotographic toner. Alternatively, the polymerized toner may be obtained by uniformly dispersing various components added to the toner in the process of producing the binder resin. It may be what is called.
[0085]
In order to obtain a magnetic toner, a magnetic powder may be contained, which can also serve as a colorant. Preferable examples of the magnetic powder include oxides or compounds of ferromagnetic elements such as iron such as magnetite or ferrite or nickel or cobalt. These magnetic powders are preferably in the form of powder having a particle size of 0.01 to 3 μm, and the surface of the magnetic powder may be treated with a resin, a titanium coupling agent, a silane coupling agent, a higher fatty acid metal salt, or the like. . These magnetic substances can be contained in the toner in an amount of 15 to 80% by weight, preferably 35 to 70% by weight. Lesser amounts may be used as colorants.
[0086]
The toner obtained according to the present invention can be prepared by various developing processes, such as the cascade developing method described in U.S. Pat. No. 2,618,552, the magnetic brushing method described in U.S. Pat. The powder cloud method described in Japanese Patent No. 2,221,776, the touch-down developing method described in US Pat. No. 3,166,432, and the so-called jumping method described in Japanese Patent Application Laid-Open No. 55-18656. Method, a so-called microtoning method using a magnetic toner produced by a pulverization method as a carrier, and a so-called bipolar magnetic toner method for obtaining a necessary toner charge by frictional charging between magnetic toners. However, the present invention is not limited to this.
[0087]
Further, the toner obtained by the present invention can be used in various fixing methods, for example, so-called oilless and oil-coated heat roll method, flash method, oven method, pressure fixing method and the like.
Further, the toner of the present invention can be used in various cleaning methods, for example, a so-called fur brush method, a blade method, and the like.
[0088]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Hereinafter, “parts” indicates parts by weight unless otherwise specified.
[0089]
1. Example of polymerization of ethylene polymer (L)
Production example (L-1);
82.0 parts of styrene monomer, 15.0 parts of n-butyl acrylate, 3.0 parts of methacrylic acid, 30 parts of a mixed solvent composed of xylene and ethylbenzene, 0.5 part of di-t- per 100 parts of monomer. A solution obtained by uniformly dissolving butyl peroxide was continuously supplied at 750 cc / hr while maintaining the conditions of a reactor internal temperature of 190 ° C., an internal pressure of 6 kgf / cm 2, and an outlet temperature of 100 ° C. to obtain a polymer (L- 1) was obtained.
[0090]
The polymerization rate of the obtained styrene polymer is 99.5% by weight, and its molecular weight is determined by using gel permeation chromatography (hereinafter referred to as GPC) using monodispersed standard polystyrene as a standard sample. Mw was 5,300, the acid value was 1.5 mg KOH / g, and Tg was 59 ° C.
[0091]
Measurement of molecular weight of polymer
The molecular weight of the polymer was measured by GPC using a commercially available monodispersed standard polystyrene as a standard, a solvent and THF, and a refractometer as a detector.
[0092]
Detector; SHODEX RI SE-31
Solvent: tetrahydrofuran
Column; A-80M x2 + KF-802
Flow rate: 1.2 ml / min
Sample: 0.25% THF solution
[0093]
Production example (L-2);
Except that the monomer composition was changed to 56.0 parts of a styrene monomer, 19.0 parts of n-butyl acrylate, and 25.0 parts of methacrylic acid, Mw 6000 and Tg 58 were obtained in the same manner as in Production Example (L-1). A solution of the polymer (L-4) having an acid value of 20.4 mgKOH / g was obtained.
[0094]
Production Example (L-3);
A 5 L four-necked flask was equipped with a cooling tube, a thermometer, a nitrogen introduction tube and a stirrer, charged with 100 parts of a xylene solvent, and heated to a reflux temperature while introducing nitrogen. And 10.0 parts of t-butylperoxy-2-ethylhexanoate were continuously dropped over 7.5 hours, and after 1 hour of post-polymerization, the remaining monomer was polymerized to obtain Mw 4500, Tg 62 ° C, and an acid value of 0.0 mg KOH / g of a solution of the polymer (L-5) was obtained.
[0095]
2. Example of polymerization of ethylene polymer (H)
Production example (h-1);
A 5 L four-necked flask was equipped with a cooling tube, a thermometer, a nitrogen inlet tube and a stirrer, charged with 28.0 parts of a styrene monomer and 12.0 parts of n-butyl acrylate, and heated to an internal temperature of 90 ° C. Thereafter, while maintaining the same temperature, bulk polymerization was performed for 16 hours. Next, 70 parts of xylene and 0.3 parts of divinylbenzene were added, and 0.3 parts of di-t-butyl peroxide, 30 parts of xylene, 0.1 part of divinylbenzene, and 45 parts of styrene monomer, which were mixed and dissolved in advance, were added. 2.0 parts and 15.0 parts of n-butyl acrylate were continuously dropped over 8.1 hours while maintaining the temperature at 125 ° C., and then the reaction was continued for 2 hours to terminate the polymerization of the remaining monomers and to prepare the polymer (h-1). Obtained.
[0096]
Polymers (h-2) to (h-10) were obtained in the same manner as polymer (h-1) under the production conditions shown in Tables 2 and 3.
[0097]
[Table 2]

[0098]
[Table 3]

[0099]
Production Example of Polymer (h-11); Comparative Production Example
A 5 L four-necked flask was equipped with a cooling tube, a thermometer, a nitrogen inlet tube and a stirrer, charged with 68.0 parts of a styrene monomer and 32.0 parts of n-butyl acrylate, and heated to an internal temperature of 100 ° C. Thereafter, the same temperature was maintained and bulk polymerization was performed for 9 hours. Next, 70 parts of xylene and 0.3 parts of divinylbenzene were added, and 0.3 parts of di-t-butyl peroxide, 30 parts of xylene, and 0.1 part of divinylbenzene, which had been mixed and dissolved in advance, were kept at 125 ° C. The mixture was continuously added dropwise over 9.0 hours, and then the reaction was continued for 1 hour to complete the polymerization of the remaining monomers. Thus, a polymer (h-11) having an Mw of 780,000 and a Tg of 43 ° C. was obtained.
[0100]
Production Example of Polymer (h-12); Comparative Production Example
A 5 L four-necked flask was equipped with a cooling tube, a thermometer, a nitrogen inlet tube and a stirrer, charged with 68.0 parts of a styrene monomer and 32.0 parts of n-butyl acrylate, and heated to an internal temperature of 120 ° C. Thereafter, the same temperature was maintained and bulk polymerization was performed for 5 hours. Next, 70 parts of xylene was added, and 0.3 parts of di-t-butyl peroxide and 30 parts of xylene, which had been mixed and dissolved in advance, were continuously added dropwise over a period of 9.0 hours while maintaining the temperature at 135 ° C. And the polymerization of the remaining monomers was terminated to obtain a polymer (h-12) having a Mw of 160,000 and a Tg of 51 ° C.
[0101]
(1) Method for measuring acid value (AV) of polymer
A precisely weighed sample is dissolved in a neutralized xylene / n-butanol (1: 1) mixed solvent, titrated with a previously standardized 1 / 10N-sodium hydroxide alcohol solution, and the amount of neutralization is calculated by the following equation. It was calculated (unit is mgKOH / g).
[0102]
(2) Manufacturing method of electrophotographic toner
The resin solution in which the resin consisting of H and L was mixed at the ratio shown in Table 5 was evaporated by a thin film evaporator to obtain a binder resin.
100 parts by weight of a binder resin, 6% of a release agent (high wax 105P) and carbon black were pre-mixed with a Henschel mixer, then melt-mixed with a twin-screw kneader, coarsely, finely pulverized, and classified to 5.0. Particles having a particle size of about 15.0 μm were obtained and subjected to an external addition treatment (Aerosil R972, 0.5%) to obtain a toner.
[0103]
Table 4 shows the physical properties of the carbon black (CB) used, and Table 5 shows the toner composition.
[0104]
[Table 4]

[0105]
[Table 5]

Production Example of Toner 22; Comparative Example 4
The ethylene-based polymer (L-1) and the ethylene-based polymer (h-5) were separately solidified by desolvation, and 65 parts and 35 parts, respectively, 6.0 parts of carbon black C, and the other were mixed with other toner. Toner 22 was obtained using the same substances, the same compounding ratio, and the same manufacturing method.
[0106]
Production Example of Toner 23; for Comparative Example 5
5. Ethylene-based polymer (L-1), ethylene-based polymers (h-11) and (h-12) were separately solidified by desolvation, and 65 parts, 25 parts, and 10 parts of carbon black C, respectively. Toner 23 was obtained according to the same composition and manufacturing method as the other toners except for 0 part.
[0107]
(3) Evaluation of fixing and high-temperature offset properties
A commercially available desktop copying machine was modified, and an experiment was performed using a testing machine capable of setting the temperature (° C.) and the rotation speed (mm / s) of the heat roller.
Evaluation of fixability: Fixing the fixed image of ID 1.0 with a Gakushin abrasion tester (load: 1.0 kg) while fixing the rotation speed of the heat roller at 400 mm / s and changing the temperature variously. After that, the ID was measured, and the ratio was determined to determine the fixing rate. The fixing rate was evaluated at the lowest roll temperature at which the fixing rate exceeded 70%.
Evaluation of high-temperature offset property: The rotation speed of the heat roller was fixed at 400 mm / s, and the temperature was variously changed to indicate the temperature at which high-temperature offset was performed.
[0108]
(4) Evaluation of blocking property
1000 mg of the electrophotographic toner was placed in a plastic bottle, tapped, kept at 50 ° C. for 16 hours, returned to room temperature, vibrated with a powder tester (manufactured by Hosokawa Micron), and evaluated based on the amount of toner remaining on the sieve.
[0109]
(5) image quality;
Using the toner described above, a 20,000 sheet image endurance test was performed using A4 size plain paper as a transfer material. Therefore, evaluation was made based on the presence or absence of image density, fog, filming, and the like. Table 6 shows the evaluation results.
[0110]
[Table 6]

[0111]
【The invention's effect】
By using the above-described electrophotographic toner of the present invention, a toner having an excellent balance of fixing / offset / blocking properties, which could not be solved by the prior art, could be obtained.

Claims (4)

In an electrophotographic toner composition containing a binder resin composition, a colorant, and a release agent as essential components, the binder resin composition has the following ethylene polymer component having a large weight average molecular weight (Mw) (H: The same applies to two types (polymer component (H1) and polymer component (H2): the same applies hereinafter) and an ethylene polymer having a small weight average molecular weight (Mw) (polymer component (L): The same as above), the weight ratio of the polymer component (H2) to the polymer component (H1) is 0.5 to 15.0, and the ethylene-based polymer (H) and the polymer component (L) A resin composition for an electrophotographic toner having a weight ratio of 10:90 to 90:10.
Polymer component (H1): a weight average molecular weight (Mw) of 200,000 to 800,000 and a glass transition temperature (Tg1) of 45 to 55 ° C
Polymer component (H2) having a weight average molecular weight (Mw) of 50,000 to 400,000 and a glass transition temperature (Tg2) of 50 to 65 ° C. (however, the weight average molecular weight of H1 is larger than the weight average molecular weight of H2) )
The polymer component (L) has a weight average molecular weight (Mw) of 3,000 to 50,000 and a glass transition temperature (Tg3) of 40 to 80 ° C. The resin composition for an electrophotographic toner according to claim 1, wherein the polymer component (H1) has a Mw of 400,000 to 800,000 and a Tg1 of more than 50C and 55C or less. 3. The resin composition for an electrophotographic toner according to claim 1, wherein the resin composition is obtained by removing a solvent from a solution containing the polymer component H1, the polymer component H2, and the polymer component L. A toner composition comprising the resin composition according to claim 1.