JP4299929B2 - Toner for electrostatic charge development - Google Patents

Description

【００１２】
[式中、Ｒ¹は４級炭素、メチン、メチレンであり、Ｎ、Ｓ、Ｏ、Ｐのヘテロ原子を含んでもよく、Ｙは飽和結合又は不飽和結合で結ばれた環状構造を表し、Ｒ²、Ｒ³は相互に独立してアルキル基、アルケニル基、アルコキシ基、置換基を有してもよいアリール基又はアリールオキシ基又はアラルキル基又はアラルキルオキシ基、ハロゲン基、水素、水酸基、置換基を有してもよいアミノ基、カルボキシル基、カルボニル基、ニトロ基、ニトロソ基、スルホニル基、シアノ基を表し、Ｒ⁴は水素又はアルキル基を表し、ｌは０又は３から１２の整数、ｍは１から２０の整数、ｎは０から２０の整数、ｏは０から４の整数、ｐは０から４の整数、ｑは０から３の整数，ｒは１から２０の整数，ｓは０から２０の整数]
で表されるジルコニウムを含む化合物により前記欠点が改良できることを見出した。
【００１３】
又特に該トナーがクロロホルム不溶分を５〜４０％含有する事により、低温定着性を損なう事無くホットオフセット性に余裕度が高く前記欠点を解消したトナーを得る事ができることが判明した。
【００１４】
ここで、クロロホルム不溶分が４０％より多い場合は、ホットオフセット性はより改良されるが、低温定着性が悪化するという不具合が見られた。
又特に該トナーが少なくとも２種類以上の軟化点が２５℃以上異なるポリエステル樹脂を含有し、各樹脂のＴＨＦ可溶分により求められたＧＰＣによる分子量分布の値が１０００〜１００００の間に少なくとも一つのピークを有している事により前記欠点を解消しさらに低温定着化ができる事を見出した。
【００１５】
軟化点が低い方の樹脂が低温定着性，軟化点が高い方の樹脂が耐ホットオフセット性への寄与が高く、軟化点差が２５℃以上離れている事で双方の樹脂が適度に相溶し、そのため双方の樹脂が有する良好な特性が選択的に得られた様な形となり、低温定着であり尚且つ高温ホットオフセットを有するトナーを得る事ができる事を見出した。ここで軟化点差が２５℃以下の場合は、双方の樹脂の相溶性が良いために双方の樹脂の良好な部分が吸収され、低温定着性と耐オフセット性の両立を図る事は困難であった。
又特に、該トナーが有している少なくとも２種類以上の樹脂の軟化点が高い方の樹脂が、クロロホルム不溶分を５〜４０％含有する事により前記欠点を解消し低温定着でなおかつホットオフセットが良好なトナーを得る事ができる事を見出した。ここで、クロロホルム不溶分が４０％より多い場合は、ホットオフセット性はより改良されるが、低温定着性が悪化するという不具合が見られた。
【００１６】
次に本発明のトナーに用いられる材料について詳細に説明する。
本発明で用いられるポリエステル樹脂は、アルコールとカルボン酸との縮重合によって得られる。使用されるアルコールとしては、例えばエチレングリコール、ジエチレングリコール、トリエチレングリコール、プロピレングリコール等のグリコール類、１．４−ビス（ヒドロキシメチル）シクロヘキサン、及びビスフェノールＡ等のエーテル化ビスフェノール類、その他二価のアルコール単量体、三価以上の多価アルコール単量体を挙げることができる。また、カルボン酸としては、例えばマレイン酸、フマール酸、フタル酸、イソフタル酸、テレフタル酸、コハク酸、マロン酸等の二価の有機酸単量体、１，２，４−ベンゼントリカルボン酸、１，２，５−ベンゼントリカルボン酸、１，２，４−シクロヘキサントリカルボン酸、１，２，４−ナフタレントリカルボン酸、１，２，５−ヘキサントリカルボン酸、１，３−ジカルボキシル−２−メチレンカルボキシプロパン、１，２，７，８−オクタンテトラカルボン酸等の三価以上の多価カルボン酸単量体を挙げることができる。ここで、ポリエステル樹脂のガラス転位温度Ｔｇは熱保存性の関係から５５℃以上がよく、より好ましくは６０℃以上が良い。
【００１７】
本発明において、トナー中の樹脂成分として、ポリエステル樹脂以外の樹脂を、トナーの性能を損なわない範囲で、併用することもできる。この場合の使用可能な樹脂としては、例えば次のようなものが挙げられるが、これらに限定はされない。ポリスチレン、クロロポリスチレン、ポリα-メチルスチレン、スチレン／クロロスチレン共重合体、スチレン／プロピレン共重合体、スチレン／ブタジエン共重合体、スチレン／塩化ビニル共重合体、スチレン／酢酸ビニル共重合体、スチレン／マレイン酸共重合体、スチレン／アクリル酸エステル共重合体(スチレン／アクリル酸メチル共重合体、スチレン／アクリル酸エチル共重合体、スチレン／アクリル酸ブチル共重合体、スチレン／アクリル酸オクチル共重合体、スチレン／アクリル酸フェニル共重合体等)、スチレン／メタクリル酸エステル共重合体(スチレン／メタクリル酸メチル共重合体、スチレン／メタクリル酸エチル共重合体、スチレン／メタクリル酸ブチル共重合体、スチレン／メタクリル酸フェニル共重合体等)、スチレン／α-クロルアクリル酸メチル共重合体、スチレン／アクリロニトリル／アクリル酸エステル共重合体等のスチレン系樹脂(スチレン又はスチレン置換体を含む単独重合体又は共重合体)、塩化ビニル樹脂、スチレン／酢酸ビニル共重合体、ロジン変性マレイン酸樹脂、フェノール樹脂、エポキシ樹脂、ポリエチレン樹脂、ポリプロピレン樹脂、アイオノマー樹脂、ポリウレタン樹脂、シリコーン樹脂、ケトン樹脂、エチレン／エチルアクリレート共重合体、キシレン樹脂、ポリビニルブチラール樹脂等、石油系樹脂、水素添加された石油系樹脂。これらの樹脂は単独使用に限らず、二種以上併用することもできる。また、これらの製造法も特に限定されるものではなく、塊状重合、溶液重合、乳化重合、懸濁重合のいずれも利用できる。
【００１８】
本発明のトナーは、必要に応じて着色剤、帯電制御剤、他の離型剤、流動性改良剤などを配合することも可能である。着色剤としては、例えばカーボンブラック、ランプブラック、鉄黒、アニリンブルー、フタロシアニンブルー、フタロシアニングリーン、ハンザイエローＧ、ローダミン６Ｃレーキ、カルコオイルブルー、クロムイエロー、キナクリドン、ベンジジンイエロー、ローズベンガル、トリアリルメタン系染料等の染顔料など、従来公知のいかなる染顔料をも単独あるいは混合して使用し得、ブラックトナーとしてもフルカラートナーとしても使用できる。これらの着色剤の使用量はトナー樹脂成分に対して、通常１〜３０重量％、好ましくは３〜２０重量％である。
【００１９】
帯電制御剤としては、ニグロシン染料、金属錯塩型染料、第四級アンモニウム塩等の従来公知のいかなる極性制御剤も、ジルコニウム系化合物と混合して使用できる。これらの極性制御剤の使用量は、トナー樹脂成分に対し、０．１〜１０重量部、好ましくは１〜５重量部である。
【００２０】
尚、本発明のジルコニウム化合物の一般的製法は、水又は／及び有機溶剤を用い、金属付与剤を用いて反応させ生成物を濾取して洗浄することによって得ることができる。本発明の化合物の製造に用いることができる金属付与剤は、４価の陽イオン体の場合はＺｒＣｌ₄、ＺｒＦ₄、ＺｒＢｒ₄，ＺｒＩ₄等のハロゲン化ジルコニウム化合物、Ｚｒ（ＯＲ）₄ （Ｒはアルキル基、アルケニル基等を示す）、又はＺｒ（ＳＯ₄）₂等の無機ジルコニウム化合物等が挙げられる。オキソ化合物の２価の陽イオン体の場合はＺｒＯＣｌ₂、ＺｒＯ（ＮＯ₃）₂、ＺｒＯ（ＣｌＯ₄）₂、Ｈ₂ＺｒＯ（ＳＯ₄）₂、ＺｒＯ（ＳＯ₄）・Ｎａ₂ＳＯ₄、ＺｒＯ（ＨＰＯ₄）₂等の無機酸ジルコニウム化合物、ＺｒＯ（ＣＯ₃）、（ＮＨ₄）₂ＺｒＯ（ＣＯ₃）₂、（ＮＨ₄）₂ＺｒＯ（Ｃ₂Ｈ₃Ｏ₂）₂、ＺｒＯ（Ｃ₂Ｈ₃₅Ｏ₂）₂、ＺｒＯ（Ｃ₁₈Ｈ₃₅Ｏ₂）₂等の有機酸ジルコニム化合物等が挙げられる。
【００２１】
又本発明においてトナーに使用される離型剤として公知のものが全て使用できるが、特に脱遊離脂肪酸型カルナウバワックス、モンタンワックス及び酸化ライスワックスを単独又は組み合わせて使用する事ができる。カルナウバワックスとしては、微結晶のものが良く、酸価が５以下であり、トナーバインダー中に分散した時の粒子径が１μｍ以下の粒径であるものが好ましい。モンタンワックスについては、一般に鉱物より精製されたモンタン系ワックスを指し、カルナウバワックス同様、微結晶であり、酸価が５〜１４であることが好ましい。酸化ライスワックスは、米ぬかワックスを空気酸化したものであり、その酸価は１０〜３０が好ましい。その他の離型剤としては、固形シリコーンワニス、高級脂肪酸高級アルコール、モンタン系エステルワックス、低分子量ポリプロピレンワックス等、従来公知のいかなる離型剤をも混合して使用できる。これらの離型剤の使用量は、トナー樹脂成分に対し、１〜２０重量部、好ましくは３〜１０重量部である。流動性改良剤としては、酸化ケイ素、酸化チタン、炭化ケイ素、酸化アルミニウム、チタン酸バリウム等、従来公知のいかなる流動性改良剤をも単独あるいは混合して使用できる。これらの流動性改良剤の使用量は、トナー重量に対し、０．１〜５重量部、好ましくは０．５〜２重量部である。
【００２２】
本発明のトナーを二成分現像剤として使用する場合に用いられるキャリアとしては、公知のものがすべて使用可能であり、例えば鉄粉、フェライト粉、ニッケル粉のごとき磁性を有する粉体、ガラスビーズ等及びこれらの表面を樹脂などで処理した物などが挙げられる。
【００２３】
本発明におけるキャリアにコーティングし得る樹脂粉末としては、スチレン−アクリル共重合体、シリコーン樹脂、マレイン酸樹脂、フッ素系樹脂、ポリエステル樹脂、エポキシ樹脂等がある。スチレン−アクリル共重合体の場合は、30〜90重量％のスチレン分を有するものが好ましい。この場合スチレン分が30重量％未満だと現像特性が低く、90重量％を越えるとコーティング膜が硬くなって剥離しやすくなり、キャリアの寿命が短くなるからである。
又本発明におけるキャリアの樹脂コーティングは、上記樹脂の他に接着付与剤、硬化剤、潤滑剤、導電材、荷電制御剤等を含有してもよい。
【００２４】
.【発明の実施の形態】
以下、本発明を下記の実施例によってさらに具体的に説明するが、本発明はこれに限定されるものではない。詳細な結果については表−１に示す。
（定着性評価）
定着ローラーとしてテフロン（商標名）ローラーを使用した（株）リコー製複写機 ＭＦ−２００の定着部を改造した装置を用いて、これにリコー製のタイプ６２００紙をセットし複写テストを行った。マクベス濃度計による画像濃度が１．２となるようなコピー画像を得、定着温度を変化させたコピー画像を砂消しゴムを装着したクロックメーターにより１０回擦り、その前後の画像濃度を測定し、下記式にて定着率を求めた。
(砂消しゴム１０回後の画像濃度)／(前の画像濃度)×１００＝定着率（％）
定着率７０％以上を達成する温度を、低温定着性の尺度となる定着下限温度とする。従来の定温定着トナーの定着下限温度は１４０〜１５０℃程度である。尚低温定着の評価条件は、紙送りの線速度を１２０〜１５０ｍｍ／ｓｅｃ、面圧１．２Ｋｇｆ／ｃｍ²、ニップ幅３ｍｍ、高温オフセットの評価条件は紙送りの線速度を５０ｍｍ／ｓｅｃ、面圧２．０Ｋｇｆ／ｃｍ²、ニップ幅４．５ｍｍと設定した。
【００２５】
コールドオフセット発生温度及び高温オフセット発生温度を以下のように求めた。
（低温定着性） 良 ◎：１３０℃未満、○：１３０〜１４０℃、□：１４０〜１５０℃、 △：１５０〜１６０℃、×：１６０℃以上 悪
（ホットオフセット）
良 ◎：２０１℃以上、○：２００〜１９１℃、□：１９０〜１８１℃、△：１８０〜１７１℃、×：１７０℃以下 悪
の５段階で行った。
（耐熱保存性評価）
トナー試料２０ｇを２０ｍｌのガラス瓶に入れ、５０回程度ガラス瓶をタッピングし試料を密に固めた後、５０℃の高温槽に２４時間放置し、その後針入度試験器を用いて針入度を以下のように求めた。
（良）◎：貫通、○：〜２５ｍｍ、□２５〜２０ｍｍ、△：２０〜１５ｍｍ，×：１５ｍｍ以下（悪）
（帯電の立上がり性評価）
トナー試料０．１５ｇとシリコーンコートキャリア６ｇをステンレス製の円柱容器内に詰め、ボールミル架台を用いて１分と１０分間混合後の帯電量をブローオフ法により測定し、以下の式により、１分混合後の帯電量と１０分混合後の帯電量との変動率として、以下のように求めた。
【００２６】
【数１】

【００２７】
（良）◎：〜２０％、○：２０〜４０％、□４０〜６０％、△：６０〜８０ｍｍ，×：８０％以上（悪）
（帯電の環境安定性評価）
１０℃、２０％相対湿度（ＲＨ）の低温低湿室及び３０℃、９０％ＲＨの高温高湿室において前記複写機を用いて各々の１万枚の複写テストを行い、１万枚後のトナー濃度をほぼ２.５％とした時の帯電量の値をブローオフ法により測定し、以下の式により、低温低湿帯電量と高温高湿帯電量との変動率とし、以下のように求めた。
【００２８】
【数２】

【００２９】
（良）◎：〜２０％、○：２０〜４０％、□４０〜６０％、△：６０〜８０％，×：８０％以上（悪）
次に、本実施例等に用いるシリコーン樹脂を被覆層に有するキャリアの製造例を示す。これは公知の手段により行うことができる。
ジルコニア系化合物１
３、５−ジ−ｔ−ブチルサリチル酸とジルコニウム化合物との反応により得られたジルコニア系化合物をジルコニア系化合物１とする。
ジルコニア系化合物２〜３
同様にして得られたジルコニア系化合物の例を以下に示すが、これらに限定はされるものではない。
【００３０】
【表１】

【００３１】
キャリア製造例１
被覆層形成液の組成
シリコン樹脂溶液（ＳＲ２１００ 東レシリコーン社製）
１００部
カーボンブラック（＃４４ 三菱化成工業社製）
４部
トルエン １００部
上記処方をホモミキサーで３０分間分散して被覆層形成液を調製した。この被覆層形成液を平均粒径１００μｍの球状フェライト１０００重量部の表面に流動床型塗布装置を用いて被覆層を形成したキャリアＡを得た。
参考例１
ポリエステル樹脂 １００部
（重量平均分子量 ５,９００、Ｔｇ ６３℃、クロロホルム不溶分２５％）
低分子量ポリプロピレン ５部
（ビスコール５５０Ｐ：三洋化成社製）
カーボンブラック １０部
（＃４４：三菱化成社製）
ジルコニア系化合物１ ２部
上記組成の混合物をヘンシェルミキサー中で十分撹拌混合した後、ロールミルで１３０〜１４０℃の温度で約３０分間加熱溶融し、室温まで冷却後、得られた混練物をジェットミル又は機械式粉砕機，風力分級機で粉砕分級しトナー母体を
得た。得られたトナー母体に疎水性シリカ０．５ｗｔ％添加混合し、最終的なトナーとした。
比較例１
参考例１のポリエステル樹脂を、以下の様なものに変更した以外は参考例１と同様なトナーを得た。
【００３２】
ポリエステル樹脂 １００部
（重量平均分子量 １０５,０００、Ｔｇ ６７℃、クロロホルム不溶分３％、分子量ピーク１４,５００）
比較例２
参考例１の荷電制御剤をジルコニア系化合物から含サリチル酸亜鉛に変更した以外は参考例１と同様なトナーを得た。
参考例２
ポリエステル樹脂 １００部
（重量平均分子量 ５,９００、Ｔｇ ６３℃、クロロホルム不溶分７％）
酸化ライスワックス ５部
カーボンブラック １０部
（＃４４：三菱化成社製）
ジルコニア系化合物２ ２部
上記組成の混合物をヘンシェルミキサー中で十分撹拌混合した後、ロールミルで１３０〜１４０℃の温度で約３０分間加熱溶融し、室温まで冷却後、得られた混練物をジェットミル又は機械式粉砕機，風力分級機で粉砕分級しトナー母体を得た。得られたトナー母体に疎水性シリカ０．５ｗｔ％添加混合し、最終的なトナーとした。
実施例３
下記の現像剤を用いた
ポリエステル樹脂（Ａ） ５０部
（重量平均分子量 ４,９００、Ｔｇ ６３℃、ＴＨＦ不溶分 ０％，軟化点１４７℃，分子量ピーク４,１００）
ポリエステル樹脂（Ｂ） ５０部
（重量平均分子量 ６,２００、Ｔｇ ６２℃、クロロホルム不溶分１０％，軟化点１０３℃，分子量ピーク３,７００）
脱遊離脂肪酸型カルナウバワックス ５部
カーボンブラック １０部
（＃４４：三菱化成社製）
ジルコニア系化合物３ ２部
上記組成の混合物をヘンシェルミキサー中で十分撹拌混合した後、ロールミルで１３０〜１４０℃の温度で約３０分間加熱溶融し、室温まで冷却後、得られた混練物をジェットミル又は機械式粉砕機，風力分級機で粉砕分級しトナー母体を得た。得られたトナー母体に疎水性シリカ０．５ｗｔ％添加混合し、最終的なトナーとした。
実施例４
実施例３のポリエステル樹脂（Ｂ）を、以下の様なものに変更した以外は実施例３と同様なトナーを得た。
【００３３】
ポリエステル樹脂（Ｂ） ５０部
（重量平均分子量 ６,２００、Ｔｇ ６２℃、クロロホルム不溶分３５％，軟化点１０１℃，分子量ピーク３,５００）
参考例５
下記の現像剤を用いた
ポリエステル樹脂（Ａ） ４５部
（重量平均分子量 ５,０００、Ｔｇ ６３℃、ＴＨＦ不溶分 ０％，軟化点１４３℃，分子量ピーク４,２００）
ポリエステル樹脂（Ｂ） ４５部
（重量平均分子量 ５,８００、Ｔｇ ６２℃、クロロホルム不溶分２０％，軟化点９９℃，分子量ピーク３,６００）
スチレン・アクリル樹脂 １５部
（重量平均分子量 ２６,０００、Ｔｇ ６６℃、クロロホルム不溶分４％，軟化点１４３℃，分子量ピーク４,３００）
脱遊離脂肪酸型カルナウバワックス ５部
カーボンブラック １０部
（＃４４：三菱化成社製）
ジルコニア系化合物１ １部
上記組成の混合物をヘンシェルミキサー中で十分撹拌混合した後、ロールミルで１３０〜１４０℃の温度で約３０分間加熱溶融し、室温まで冷却後、得られた混練物をジェットミル又は機械式粉砕機，風力分級機で粉砕分級しトナー母体を
得た。得られたトナー母体に疎水性シリカ０．５ｗｔ％添加混合し、最終的なトナーとした。
【００３４】
【表２】

【００３５】
【発明の効果】
上記の通り、本発明により、低温定着性と熱保存性及び帯電安定性の全てを満足した静電荷像現像用トナーを提供する事ができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming toner used for developing an electrostatic latent image such as an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and the like. The present invention relates to an image forming toner for securing a temperature range and stabilizing charging with time.
[0002]
[Prior art]
Conventionally, various electrophotographic methods have been described in US Pat. No. 2,297,691, Japanese Patent Publication No. 49-23910, Japanese Patent Publication No. 43-24748, etc. Using an electroconductive substance, an electric latent image is formed on the photoconductor by various means, and then the latent image is developed with toner, and the toner powder image is transferred to paper or the like as necessary. The image is fixed by heating, pressurization or solvent vapor to obtain a copy image.
[0003]
Methods for developing electrical latent images can be broadly divided into a liquid development method using a developer in which various pigments and dyes are finely dispersed in an insulating organic liquid, a cascade method, a magnetic brush method, and a powder cloud method. As described above, there is a dry development method using a toner in which a colorant such as carbon black is dispersed in a natural or synthetic resin, and the dry development method has been widely used in recent years.
[0004]
In order to visualize the electrostatic latent image, it is necessary to apply a charge to the toner by frictional charging. Generally, a method in which a charge control agent is contained in the toner is used. Some charge control agents have the effect of imparting positive chargeability and negative chargeability. Examples of charge control agents that impart negative chargeability include nigrosine dyes, azine dyes, metal complexes of monoazo dyes, metal complexes of salicylic acid, and copper phthalocyanine pigments. In particular, metal complex salts of monoazo dyes are widely used for black toners because of their high charge imparting ability. However, with regard to the special resin configuration of the low temperature fixing type such as this time, the charge control agent as used in the past has insufficient dispersibility of the charge control agent in the resin, and in terms of charging stability. There was a problem.
[0005]
In addition, as a fixing method in the electrophotographic method, a heating heat roller method is widely used because of its energy efficiency. Further, as in recent low-temperature fixing and high-speed copying for energy saving, the thermal energy given to the toner at the time of fixing tends to be small. In general, attempts have been made to improve the low-temperature fixability of the toner used for such low-temperature fixing by using a resin or wax having a low softening point. However, such a low-temperature fixing toner is known to cause so-called blocking because it is thermally weak and hardens due to the heat of the machine being used or heat during storage. In addition, it is difficult to secure a sufficient fixing temperature range, and even if a polyester resin, which is said to have relatively good heat storage for good low-temperature fixability, a toner that still solves this problem can be obtained. Not.
[0006]
In order to solve these problems, several methods using two types of polyester resins having different characteristics have been proposed. For example, a method of mixing a non-linear polyester resin and a linear polyester resin (Japanese Patent Laid-Open No. 60-90344), a crosslinked polyester resin having a Tg of 50 ° C. or more and a softening point of 200 ° C. or less and a softening point of 150 ° C. or less MW 3,000 to Method of mixing 50,000 linear polyester resin (Japanese Patent Laid-Open No. 64-15755), MW 5,000 or more, non-linear polymer polyester resin having a dispersion ratio of 20 or more and MW 1,000 to 5,000, dispersion A method of containing a non-linear polyester resin having a ratio of 4 or less (JP-A-2-82267), an organometallic compound comprising a linear polyester resin having an acid value of 5 to 60 and a non-linear polyester resin having an acid value of less than 5 Method of containing (Japanese Patent Laid-Open No. 3-229264), saturated polyester resin and different polyester resins having an acid value ratio of 1.5 or more Mixing method for it is (JP-A-3-41470 JP) or the like. However, in recent years, low-temperature fixing has been increasingly progressed, and further constant-temperature fixing has been demanded. In combination with downsizing of the device, securing low-temperature fixing property and fixing temperature range when using a low-load fixing device and heat storage It is becoming difficult to achieve both.
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide an image forming toner satisfying all of low-temperature fixability, heat storage stability and charging stability.
[0008]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors have found that a toner containing at least a polyester resin, a colorant, and a wax as a binder resin has a molecular weight distribution value of 1000 to 10,000 as determined by the THF soluble content of the toner. It was found that the above-mentioned drawbacks can be eliminated by containing a zirconium-based compound having at least one peak in between and having a half-value width of 15,000 or less in the distribution and further having the following structure.
[0009]
Here, when the peak of the molecular weight distribution by GPC is less than 1000, there is a problem especially in hot offset property, and there is a problem in coexistence with low temperature fixability. Also, when there was a peak at a portion greater than 10,000, there was a problem with low-temperature fixability.
[0010]
In particular, when the half-value width of the distribution is larger than 15,000, the low-temperature fixability is inferior, and particularly when the thick paper is used, the fixability is remarkably deteriorated.
In particular, as a charge control agent, an aromatic oxycarboxylic acid or a salt thereof and a zirconium-based compound obtained from a compound containing zirconium or oxyzirconium react with a highly reactive part of the resin and wax to form a lightly crosslinked structure. In addition to improving hot offset resistance, the dispersion in the low-temperature fixing type resin is appropriately performed, so that the rising of the charge in frictional charging is fast and a stable charge amount can be obtained over time. found. The amount of the polarity control agent used is 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on the toner resin component.
In particular, the compound has the following structural formula:
[Chemical formula 2]

[0012]
[Wherein R ¹ is quaternary carbon, methine, methylene, and may contain a heteroatom of N, S, O, P, Y represents a cyclic structure connected by a saturated bond or an unsaturated bond, and R ² and R ³ are each independently an alkyl group, an alkenyl group, an alkoxy group, an aryl group or an aryloxy group or an aralkyl group or an aralkyloxy group which may have a substituent, a halogen group, hydrogen, a hydroxyl group or a substituent. Represents an amino group, a carboxyl group, a carbonyl group, a nitro group, a nitroso group, a sulfonyl group, or a cyano group, R ⁴ represents hydrogen or an alkyl group, l is 0 or an integer of 3 to 12, m Is an integer from 1 to 20, n is an integer from 0 to 20, o is an integer from 0 to 4, p is an integer from 0 to 4, q is an integer from 0 to 3, r is an integer from 1 to 20, and s is 0 To an integer from 20]
It has been found that the above-mentioned defects can be improved by a compound containing zirconium represented by
[0013]
In particular, it has been found that when the toner contains 5 to 40% of a chloroform-insoluble matter, a toner having a high margin in hot offset property can be obtained without impairing the low-temperature fixability.
[0014]
Here, when the amount of insoluble chloroform was more than 40%, the hot offset property was further improved, but there was a problem that the low-temperature fixability deteriorated.
In particular, the toner contains at least two types of polyester resins having different softening points of 25 ° C. or more, and at least one of the molecular weight distribution values by GPC determined by the THF-soluble content of each resin is between 1000 and 10,000. It has been found that having the peak eliminates the above-described drawbacks and further enables low-temperature fixing.
[0015]
The resin with the lower softening point contributes to the low temperature fixability, the resin with the higher softening point contributes to hot offset resistance, and the difference between the softening points is 25 ° C or more, so both resins are compatible with each other. For this reason, the present inventors have found that good characteristics possessed by both resins can be selectively obtained, and a toner having a low temperature fixing and a high temperature hot offset can be obtained. Here, when the difference in softening point is 25 ° C. or less, the compatibility of both resins is good, so that a good portion of both resins is absorbed, and it is difficult to achieve both low temperature fixability and offset resistance. .
In particular, the resin having the higher softening point of at least two kinds of resins contained in the toner contains 5 to 40% of chloroform insoluble matter, thereby eliminating the above-mentioned disadvantages and performing low temperature fixing and hot offset. It has been found that a good toner can be obtained. Here, when the amount of insoluble chloroform was more than 40%, the hot offset property was further improved, but there was a problem that the low-temperature fixability deteriorated.
[0016]
Next, materials used for the toner of the present invention will be described in detail.
The polyester resin used in the present invention is obtained by condensation polymerization of alcohol and carboxylic acid. Examples of the alcohol used include glycols such as ethylene glycol, diethylene glycol, triethylene glycol and propylene glycol, etherified bisphenols such as 1.4-bis (hydroxymethyl) cyclohexane and bisphenol A, and other dihydric alcohols. Mention may be made of monomers and trihydric or higher polyhydric alcohol monomers. Examples of carboxylic acids include divalent organic acid monomers such as maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, and malonic acid, 1,2,4-benzenetricarboxylic acid, 1 , 2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxy Mention may be made of trivalent or higher polyvalent carboxylic acid monomers such as propane and 1,2,7,8-octanetetracarboxylic acid. Here, the glass transition temperature Tg of the polyester resin is preferably 55 ° C. or higher, more preferably 60 ° C. or higher, from the viewpoint of heat preservation.
[0017]
In the present invention, as the resin component in the toner, a resin other than the polyester resin can be used in combination as long as the performance of the toner is not impaired. Examples of usable resins in this case include the following, but are not limited thereto. Polystyrene, chloropolystyrene, poly α-methylstyrene, styrene / chlorostyrene copolymer, styrene / propylene copolymer, styrene / butadiene copolymer, styrene / vinyl chloride copolymer, styrene / vinyl acetate copolymer, styrene / Maleic acid copolymer, styrene / acrylic acid ester copolymer (styrene / methyl acrylate copolymer, styrene / ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / octyl acrylate copolymer) Styrene / phenyl acrylate copolymer, etc.), styrene / methacrylic acid ester copolymer (styrene / methyl methacrylate copolymer, styrene / ethyl methacrylate copolymer, styrene / butyl methacrylate copolymer, styrene) / Phenyl methacrylate copolymer, etc.), styrene / Α-chloromethyl acrylate copolymer, styrene resin such as styrene / acrylonitrile / acrylate ester copolymer (homopolymer or copolymer containing styrene or styrene substitution product), vinyl chloride resin, styrene / acetic acid Vinyl copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene / ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, etc. Petroleum resin, hydrogenated petroleum resin. These resins are not limited to single use but can be used in combination of two or more. Also, these production methods are not particularly limited, and any of bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization can be used.
[0018]
The toner of the present invention can be blended with a colorant, a charge control agent, another releasing agent, a fluidity improving agent, and the like as required. Examples of the colorant include carbon black, lamp black, iron black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G, rhodamine 6C lake, calco oil blue, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane. Any conventionally known dyes and pigments such as dyes such as dyes can be used alone or as a mixture, and can be used as a black toner or a full color toner. The amount of these colorants to be used is usually 1 to 30% by weight, preferably 3 to 20% by weight, based on the toner resin component.
[0019]
As the charge control agent, any conventionally known polarity control agent such as a nigrosine dye, a metal complex dye, or a quaternary ammonium salt can be used by mixing with a zirconium compound. The amount of these polar control agents used is 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on the toner resin component.
[0020]
In addition, the general manufacturing method of the zirconium compound of this invention can be obtained by using water or / and an organic solvent, making it react with a metal provision agent, filtering and wash | cleaning a product. In the case of a tetravalent cation, the metal imparting agent that can be used for the production of the compound of the present invention is a zirconium halide compound such as ZrCl ₄ , ZrF ₄ , ZrBr ₄ , ZrI ₄ , Zr (OR) ₄ (R Represents an alkyl group, an alkenyl group, or the like), or an inorganic zirconium compound such as Zr (SO ₄ ) ₂ . In the case of a divalent cation of an oxo compound, ZrOCl ₂ , ZrO (NO ₃ ) ₂ , ZrO (ClO ₄ ) ₂ , H ₂ ZrO (SO ₄ ) ₂ , ZrO (SO ₄ ) · Na ₂ SO ₄ , ZrO Inorganic acid zirconium compounds such as (HPO ₄ ) ₂ , ZrO (CO ₃ ), (NH ₄ ) ₂ ZrO (CO ₃ ) ₂ , (NH ₄ ) ₂ ZrO (C ₂ H ₃ O ₂ ) ₂ , ZrO (C ₂ And organic acid zirconium compounds such as H ₃₅ O ₂ ) ₂ and ZrO (C ₁₈ H ₃₅ O ₂ ) ₂ .
[0021]
In the present invention, all known release agents for use in the toner can be used, and in particular, de-free fatty acid type carnauba wax, montan wax and oxidized rice wax can be used alone or in combination. The carnauba wax is preferably a microcrystalline one, having an acid value of 5 or less and a particle size of 1 μm or less when dispersed in a toner binder. The montan wax generally refers to a montan wax refined from minerals, and like a carnauba wax, it is microcrystalline and preferably has an acid value of 5 to 14. The oxidized rice wax is obtained by air-oxidizing rice bran wax, and the acid value is preferably 10-30. As other mold release agents, any conventionally known mold release agents such as solid silicone varnish, higher fatty acid higher alcohol, montan ester wax, and low molecular weight polypropylene wax can be mixed and used. The amount of these release agents used is 1 to 20 parts by weight, preferably 3 to 10 parts by weight, based on the toner resin component. As the fluidity improver, any conventionally known fluidity improver such as silicon oxide, titanium oxide, silicon carbide, aluminum oxide, and barium titanate can be used alone or in combination. The amount of these fluidity improvers used is 0.1 to 5 parts by weight, preferably 0.5 to 2 parts by weight, based on the toner weight.
[0022]
As the carrier used when the toner of the present invention is used as a two-component developer, any known carrier can be used, for example, magnetic powder such as iron powder, ferrite powder, nickel powder, glass beads, etc. And those whose surfaces are treated with a resin or the like.
[0023]
Examples of the resin powder that can be coated on the carrier in the present invention include a styrene-acrylic copolymer, a silicone resin, a maleic acid resin, a fluorine resin, a polyester resin, and an epoxy resin. In the case of a styrene-acrylic copolymer, those having a styrene content of 30 to 90% by weight are preferred. In this case, if the styrene content is less than 30% by weight, the developing characteristics are low, and if it exceeds 90% by weight, the coating film becomes hard and easily peeled, and the life of the carrier is shortened.
Moreover, the resin coating of the carrier in the present invention may contain an adhesion-imparting agent, a curing agent, a lubricant, a conductive material, a charge control agent, and the like in addition to the above resin.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto. Detailed results are shown in Table-1.
(Fixability evaluation)
Using a device in which the fixing unit of the Ricoh Co., Ltd. MF-200, which uses a Teflon (trade name) roller as a fixing roller, was modified, Ricoh type 6200 paper was set on this and a copying test was performed. A copy image having an image density of 1.2 with a Macbeth densitometer was obtained, and the copy image with the fixing temperature changed was rubbed 10 times with a clock meter equipped with a sand eraser, and the image density before and after that was measured. The fixing rate was determined by the formula.
(Image density after 10 times of sand eraser) / (Previous image density) × 100 = Fixing rate (%)
The temperature at which a fixing rate of 70% or more is achieved is defined as a lower limit fixing temperature that is a measure of low-temperature fixability. The fixing minimum temperature of the conventional constant temperature fixing toner is about 140 to 150 ° C. The evaluation conditions for low-temperature fixing are as follows: the paper feed linear velocity is 120 to 150 mm / sec, the surface pressure is 1.2 Kgf / cm ² , the nip width is 3 mm, and the high temperature offset is the evaluation condition for the paper feed linear velocity is 50 mm / sec. The pressure was set to 2.0 kgf / cm ² and the nip width was 4.5 mm.
[0025]
The cold offset occurrence temperature and the high temperature offset occurrence temperature were determined as follows.
(Low-temperature fixability) Good ◎: Less than 130 ° C, ○: 130-140 ° C, □: 140-150 ° C, △: 150-160 ° C, x: 160 ° C or more Poor (hot offset)
Good: 201 ° C. or higher, ○: 200 to 191 ° C., □: 190 to 181 ° C., Δ: 180 to 171 ° C., x: 170 ° C. or lower.
(Heat resistant storage stability evaluation)
20g of toner sample is put in a 20ml glass bottle, and the glass bottle is tapped about 50 times to harden the sample tightly, and then left in a high temperature bath at 50 ° C for 24 hours. I asked for it.
(Good) ◎: penetration, ○: ~ 25 mm, □ 25-20 mm, Δ: 20-15 mm, x: 15 mm or less (bad)
(Evaluation of rising characteristics of electrification)
0.15 g of toner sample and 6 g of silicone coated carrier are packed in a stainless steel cylindrical container, and the charge amount after mixing for 1 minute and 10 minutes using a ball mill stand is measured by the blow-off method. The variation rate between the subsequent charge amount and the charge amount after mixing for 10 minutes was determined as follows.
[0026]
[Expression 1]

[0027]
(Good) ◎: 20%, ○: 20-40%, □ 40-60%, Δ: 60-80 mm, x: 80% or more (bad)
(Evaluation of environmental stability of charging)
Each of the 10,000 copies was tested using the copying machine in a low-temperature and low-humidity chamber at 10 ° C. and 20% relative humidity (RH) and a high-temperature and high-humidity chamber at 30 ° C. and 90% RH. The value of the charge amount when the concentration was approximately 2.5% was measured by the blow-off method, and the variation rate between the low-temperature and low-humidity charge amount and the high-temperature and high-humidity charge amount was obtained by the following formula, and was obtained as follows.
[0028]
[Expression 2]

[0029]
(Good) ◎: 20%, ○: 20-40%, □ 40-60%, Δ: 60-80%, x: 80% or more (bad)
Next, the manufacture example of the carrier which has the silicone resin used for a present Example etc. in a coating layer is shown. This can be done by known means.
Zirconia compound 1
A zirconia compound obtained by the reaction of 3,5-di-t-butylsalicylic acid and a zirconium compound is referred to as a zirconia compound 1.
Zirconia compounds 2-3
Examples of zirconia compounds obtained in the same manner are shown below, but are not limited thereto.
[0030]
[Table 1]

[0031]
Carrier production example 1
Composition of coating layer forming solution Silicone resin solution (SR2100, manufactured by Toray Silicone Co., Ltd.)
100 parts carbon black (# 44 made by Mitsubishi Chemical Industries)
4 parts Toluene 100 parts The above formulation was dispersed with a homomixer for 30 minutes to prepare a coating layer forming solution. A carrier A in which the coating layer was formed on the surface of 1000 parts by weight of spherical ferrite having an average particle diameter of 100 μm by using a fluidized bed coating apparatus was obtained from this coating layer forming liquid.
Reference example 1
100 parts of polyester resin (weight average molecular weight 5,900, Tg 63 ° C., chloroform insoluble content 25%)
Low molecular weight polypropylene 5 parts (Biscol 550P: manufactured by Sanyo Chemical Industries)
10 parts of carbon black (# 44: manufactured by Mitsubishi Kasei)
2 parts of zirconia compound 1 A mixture of the above composition was sufficiently stirred and mixed in a Henschel mixer, heated and melted at a temperature of 130 to 140 ° C. for about 30 minutes with a roll mill, cooled to room temperature, and the resulting kneaded product was jet milled Alternatively, a toner base was obtained by pulverization and classification using a mechanical pulverizer or an air classifier. The obtained toner base was mixed with 0.5 wt% of hydrophobic silica to obtain a final toner.
Comparative Example 1
A toner similar to that of Reference Example 1 was obtained except that the polyester resin of Reference Example 1 was changed to the following.
[0032]
100 parts of polyester resin (weight average molecular weight 105,000, Tg 67 ° C., chloroform insoluble content 3%, molecular weight peak 14,500)
Comparative Example 2
A toner similar to that of Reference Example 1 was obtained except that the charge control agent of Reference Example 1 was changed from a zirconia-based compound to zinc-containing salicylate.
Reference example 2
100 parts of polyester resin (weight average molecular weight 5,900, Tg 63 ° C., chloroform insoluble content 7%)
Oxidized rice wax 5 parts Carbon black 10 parts (# 44: manufactured by Mitsubishi Kasei)
2 parts of zirconia compound 2 A mixture of the above composition was sufficiently stirred and mixed in a Henschel mixer, heated and melted at a temperature of 130 to 140 ° C. for about 30 minutes with a roll mill, cooled to room temperature, and the resulting kneaded product was jet milled Alternatively, a toner base was obtained by pulverization and classification using a mechanical pulverizer or an air classifier. The obtained toner base was mixed with 0.5 wt% of hydrophobic silica to obtain a final toner.
Example 3
50 parts of polyester resin (A) using the following developer (weight average molecular weight 4,900, Tg 63 ° C., THF insoluble content 0%, softening point 147 ° C., molecular weight peak 4,100)
50 parts of polyester resin (B) (weight average molecular weight 6,200, Tg 62 ° C., chloroform insoluble content 10%, softening point 103 ° C., molecular weight peak 3,700)
De-free fatty acid type carnauba wax 5 parts Carbon black 10 parts (# 44: manufactured by Mitsubishi Kasei)
Zirconia compound 3 2 parts A mixture of the above composition was sufficiently stirred and mixed in a Henschel mixer, heated and melted at a temperature of 130 to 140 ° C. for about 30 minutes with a roll mill, cooled to room temperature, and the resulting kneaded product was jet milled Alternatively, a toner base was obtained by pulverization and classification using a mechanical pulverizer or an air classifier. The obtained toner base was mixed with 0.5 wt% of hydrophobic silica to obtain a final toner.
Example 4
A toner similar to that of Example 3 was obtained except that the polyester resin (B) of Example 3 was changed to the following.
[0033]
50 parts of polyester resin (B) (weight average molecular weight 6,200, Tg 62 ° C., chloroform insoluble content 35%, softening point 101 ° C., molecular weight peak 3,500)
Reference Example 5
45 parts of polyester resin (A) using the following developer (weight average molecular weight 5,000, Tg 63 ° C., THF insoluble content 0%, softening point 143 ° C., molecular weight peak 4,200)
45 parts of polyester resin (B) (weight average molecular weight 5,800, Tg 62 ° C., chloroform insoluble content 20%, softening point 99 ° C., molecular weight peak 3,600)
Styrene / acrylic resin 15 parts (weight average molecular weight 26,000, Tg 66 ° C., chloroform insoluble content 4%, softening point 143 ° C., molecular weight peak 4,300)
De-free fatty acid type carnauba wax 5 parts Carbon black 10 parts (# 44: manufactured by Mitsubishi Kasei)
1 part of zirconia compound 1 A mixture of the above composition was sufficiently stirred and mixed in a Henschel mixer, heated and melted at a temperature of 130 to 140 ° C. for about 30 minutes with a roll mill, cooled to room temperature, and the resulting kneaded product was jet milled Alternatively, a toner base was obtained by pulverization and classification using a mechanical pulverizer or an air classifier. The obtained toner base was mixed with 0.5 wt% of hydrophobic silica to obtain a final toner.
[0034]
[Table 2]

[0035]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a toner for developing an electrostatic image satisfying all of low-temperature fixability, thermal storage stability, and charging stability.

Claims (2)

In a toner mainly containing at least a polyester resin, a colorant, and a wax as a binder resin, the toner contains 5 to 40% of a chloroform-insoluble component, and the molecular weight by GPC determined from the THF-soluble component of the toner. The distribution value has at least one main peak between 1000 and 10000, the half width of the distribution is 15,000 or less in molecular weight, and further contains an aromatic oxycarboxylic acid or a salt thereof and zirconium or oxyzirconium. An electrostatic charge developing toner comprising a zirconium-based compound represented by the following structural formula obtained from a compound.

[Wherein R ¹ is quaternary carbon, methine, methylene, and may contain a heteroatom of N, S, O, P, Y represents a cyclic structure connected by a saturated bond or an unsaturated bond, and R ² and R ³ are each independently an alkyl group, an alkenyl group, an alkoxy group, an aryl group or an aryloxy group or an aralkyl group or an aralkyloxy group which may have a substituent, a halogen group, hydrogen, a hydroxyl group or a substituent. Represents an amino group, a carboxyl group, a carbonyl group, a nitro group, a nitroso group, a sulfonyl group, or a cyano group, R ⁴ represents hydrogen or an alkyl group, l is 0 or an integer of 3 to 12, m Is an integer from 1 to 20, n is an integer from 0 to 20, o is an integer from 0 to 4, p is an integer from 0 to 4, q is an integer from 0 to 3, r is an integer from 1 to 20, and s is 0 To an integer from 20] The toner contains at least two types of polyester resins having different softening points of 25 ° C. or more, and at least one main peak between GPC molecular weight distribution values of 1000 to 10,000 determined by the THF soluble content of each resin. The electrostatic charge developing toner according to claim 1, wherein