JP3581551B2 - Yellow toner and method for producing the same - Google Patents

Description

【００２５】
本発明者は鋭意検討の結果、発色性および透明性に優れている本発明の着色剤に、分散剤として特定の金属化合物を用いることで、従来得られなかった優れた分散状態をトナー化した状態においても得られることを見出し、本発明に至った。
【００２６】
【発明の実施の形態】
本発明の特徴の一つは着色剤そのものの透明性・分散性が優れている着色剤化合物（Ｉ）を用いることである。
【００２７】
本発明の着色剤は一般的にＣ．Ｉ．Ｐｉｇ．Ｙｅｌｌｏｗ１６６に分類される着色剤であり、トナー結着樹脂１００重量部に対し２〜８重量部の添加で優れた着色力を発揮する。
【００２８】
また、本発明の着色剤は、色味改善のため他の従来公知の着色剤と組み合わせることが可能であるが、本発明の着色剤の透明性を損なわない範囲で添加することが好ましく、本発明の着色剤１００重量部に対して２０重量部未満であることが好ましい。
【００２９】
加えて、本発明者は、表面が完全には溶融していないトランスペアレンシー画像の透過光においてその色相角が最も変化しない条件を検討した結果、ある特定の一次粒径を有する着色剤を選択することによって、ある程度抑えることが可能なことを見出した。
【００３０】
従来このような観点で例えば特開平４−３４２２６５号公報にはキナクリドン顔料の一次粒子径が記載され、階調性を出す等の目的のための例として特開平４−２０４５４７号公報にはカーボンブラックが記載されている。
【００３１】
しかし、本発明のような表面が完全には溶融していないトランスペアレンシー画像に単純に応用した場合、従来に比べ抑えられるものの、特にイエロー透過光において色相角・色域が変化してしまう。
【００３２】
即ち本発明においては、上記の観点より顔料そのものの透明性が必須であり、透明性を有している点と微細な粒径に分散状態を制御する容易さにおいても本発明の着色剤は優れた特性を発揮する。
【００３３】
本発明において上記化合物（Ｉ）の一次粒径は０．０１〜０．７０μｍ、好ましくは０．０１〜０．４０μｍであることが良く、より好ましくは粒径個数分布の変動係数にして６０％以下であることが好ましい。
【００３４】
化合物（Ｉ）の一次粒径が０．０１μｍ未満であると、その耐光性が極端に低下するだけでなく、製造時のハンドリング性や帯電性に悪影響を及ぼす。
【００３５】
また、化合物（Ｉ）の一次粒径が０．７０μｍ、粒径個数分布の変動係数が６０％をそれぞれ超えると、着色剤の凝集が製造時に生じやすくなり、トランスペアレンシー画像の透過光の色相角・色域が紙上のものと変化してしまう。また、透過画像も暗くなってしまう。
【００３６】
なお、本発明における着色剤の粒径は以下の方法で具体的に測定される。
【００３７】
まず常温硬化性のエポキシ樹脂中にトナーを十分分散させた後、温度４０℃の雰囲気中で２日間硬化させ得られた硬化物を四三酸化ルテニウム、必要により四三酸化オスミウムを併用し染色を施した後、ダイヤモンド歯を備えたミクロトームを用い薄片状のサンプルを切り出し、透過電子顕微鏡（ＴＥＭ）を用いてトナーの断層形態を測定した。
【００３８】
そして得られたトナー断面像を１００個無作為にサンプリングし、その画像情報はインターフェースを介してニコレ社製画像解析装置（Ｌｕｚｅｘ３）に導入し、解析を行い粒度分布として得た値を着色剤の一次粒径とした。
【００３９】
本発明の別の特徴は、特定の着色剤分散剤としてサリチル酸金属化合物を用いることである。
【００４０】
本発明の着色剤はその粒径制御がしやすいことが特徴であるが、トナー結着樹脂・離型剤等の相溶性や、トナー帯電性の観点より、再凝集や帯電性の不良を生じやすい傾向にあり、トナーとした場合に必ずしも充分とは言えないものになってしまう。
【００４１】
これに対して従来分散性向上からの技術としては、例えば特開平２−１７５７７０号公報に記載されるようないわゆるフラッシング法、特開平５−２４７３７０号公報に示される様に顔料の表面処理を行なう方法等多くの手段が開示されているが、トナー帯電性を適正な範囲に制御するための汎用性や工程の簡略化等を考えると未だ不十分なものであった。
【００４２】
そこで本発明者は、本発明の着色剤に適した分散向上添加剤の作用と共に帯電性の制御も可能な物質について検討を行ない、本発明に至った。
【００４３】
本発明のサリチル酸金属化合物としては、アルミニウム、クロム、亜鉛、鉄を中心金属とした錯体および／または錯塩が好ましく、本発明の着色剤への帯電的な適応性よりアルミニウムを中心金属とした化合物が最も好ましい。
【００４４】
本発明の顔料に対してサリチル酸金属化合物を添加し、改善する手段としては、あらかじめマスターバッチ化する等の公知の手段が使用できるが、改質性／分散性／再凝集防止性等の効果を得るため、両者の添加時には顔料１００重量部に対して１０〜４００重量部の比で添加することが好ましく、１０〜１００重量部の比で添加することが、より好ましい。
【００４５】
本発明の更なる特徴としては、本発明の着色剤分散助剤の作用を有する離型剤として特定のエステルワックスを添加することである。
【００４６】
これは、本発明の構造を有する顔料の官能基にワックス中のエステル基が親和性を有するため、顔料が疎水性を有するワックスに取り入れ、トナー中に埋没してしまうために生じると考えている。
【００４７】
そのため本発明においては、エステル基を有するワックスを本発明の顔料に組み合わせることによって帯電性の向上が達成される。
【００４８】
そしてその観点より検討を行なった結果、本発明のワックスは炭素数が１５以上の長鎖のエステル部分を１個以上有することがより好ましく、１５以上３０以下であることがさらに好ましい。
【００４９】
炭素数が１５未満であると顔料の表面改質はするものの、定着機の熱量のために定着ローラー面への着色剤の移行が生じやすくなるため、定着時に紙への裏写りが生じやすくなりローラー耐久性を低下させる。
【００５０】
炭素数が３０を超えると、ワックスの樹脂への可塑効果が大きくなりすぎて定着性が低下する。また、透明性も悪化する。
【００５１】
また、近年フルカラー両面画像の必要性も増してきており、両面画像を形成せしめる際においては、最初に表面に形成された転写紙上のトナー像が次に裏面に画像を形成する時にも定着器の加熱部を再度通過する可能性があり、よりトナーの耐高温オフセット性を十分に考慮する必要がある。そのためにも本発明においては、多量のエステルワックスの添加が必要となる。
【００５２】
そのため、本発明のエステルワックスとしては顔料の改質のほかに離型性／透明性も与える必要があり、エステルワックスをトナー中に５〜３０重量％添加することが好ましい。
【００５３】
仮に５重量％未満の添加では十分な改質性を示さず、更に両面画像の定着時において裏面の画像がオフセット現象を示す傾向がある。
【００５４】
また３０重量％を超える場合は、トナーの製造時に、例えば製造において装置融着やトナーの融着が発生しやすく、ドラムに対しての耐衝撃力が低下するためフィルミングが発生しやすくなる。
【００５５】
また本発明の顔料に対してエステルワックスを添加し、改質する手段としては、あらかじめマスターバッチ化する等の公知の手段が使用できるが、改質性／分散性／再凝集性等の効果を得るため、添加時には本発明のサリチル酸金属塩および顔料の１００重量部に対してエステルワックス１００〜３０００重量部の比で添加することが好ましい。
【００５６】
本発明において、用いられるエステルワックスとしてはＡＳＴＭ Ｄ３４１８−８に準拠し測定された主体極大ピーク値が、４０〜９０℃を示す化合物が好ましい。極大ピークが４０℃未満であると低軟化点物質の自己凝集力が弱くなり、結果として耐高温オフセット性が弱くなりフルカラートナーには好ましくない。一方極大ピークが、９０℃を超えると定着温度が高くなり、定着画像表面を適度に平滑化せしめることが困難となり混色性の点から好ましくない。
【００５７】
本発明の極大ピーク値の温度の測定には、例えばパーキンエルマー社製ＤＳＣ−７を用いる。装置検出部の温度補正はインジウムと亜鉛の融点を用い、熱量の補正についてはインジウムの融解熱を用いる。サンプルはアルミニウム製パンを用い対照用に空パンをセットし、昇温速度１０℃／ｍｉｎで測定した。
【００５８】
本発明に好ましい具体的なエステルワックスの代表的化合物の構造式を以下に一般構造式▲１▼〜▲５▼として示す。
【００５９】
【化８】

（ａ及びｂは、０〜４の整数を示し、ａとｂの合計が４であり、
Ｒ_１及びＲ_２は、炭素数が１〜４０の整数を有する有機基を示し、且つＲ_１とＲ_２
との炭素数差が３以上であり、
ｍ及びｎは、０〜２５の整数を示し、ｍとｎが同時に０になることはない。）
【００６０】
【化９】

（ａ及びｂは、０〜３の整数を示し、ａとｂの合計は１乃至３であり、
Ｒ_１及びＲ_２は、炭素数が１〜４０の整数を有する有機基を示し、且つＲ_１とＲ_２
との炭素数差が３以上であり、
Ｒ_３ は、水素原子又は炭素数が１以上の有機基を示し、但し、ａとｂの合計
が２のとき、Ｒ_３ の少なくとも一方は、炭素数が１以上の有機基を
示し、
ｋは、１〜３の整数を示し、
ｍ又はｎは、０〜２５の整数を示し、ｍとｎが同時に０になることはない。）
【００６１】
【化１０】

（Ｒ_１及びＲ_３は、炭素数６〜３２を有する有機基を示し、Ｒ_１とＲ_３は同じもので
あってもなくても良く、
Ｒ_２は、炭素数１〜２０を有する有機基を示す。）
【００６２】
【化１１】

（Ｒ_１及びＲ_３は、炭素数６〜３２を有する有機基を示し、Ｒ_１とＲ_３は同じものであってもなくても良く、
Ｒ_２は、−ＣＨ_２ＣＨ_２ＯＣ_６Ｈ_４ＯＣＨ_２ＣＨ_２−，
−（ＣＨ（ＣＨ_３）ＣＨ_２Ｏ）_ｍ−Ｃ_６Ｈ_４Ｃ（ＣＨ_３）_２Ｃ_６Ｈ_４−
（ＯＣＨ_２ＣＨＣＨ_３）_ｍ−の変性ビスフェノール骨格を有するもの
又は、（ＣＨ_２）_ｎ−を示し、ｍは１〜１０の整数を示し、ｎは１〜
２０の整数を示す。）
【００６３】
【化１２】

（ａは、０〜４の整数を示し、ｂは、１〜４の整数を示し、ａとｂの合計は４で
あり、
Ｒ_１は、炭素数が１〜４０の整数を有する有機基を示し、
ｍ及びｎは、０〜２５の整数を示し、ｍとｎが同時に０になることはない。）
【００６４】
本発明において、トナーが含有する低軟化点物質は、上記▲１▼乃至▲５▼のいずれかで示される物質を主成分とすることが好ましい。なお、本発明において主成分とは、次に述べるガスクロマトグラフィー法（ＧＣ法）において、低軟化点物質全てのピーク面積の合計に対して、本発明の物質のピーク面積が５５％以上含まれていることを意味する。
【００６５】
ガスクロマトグラフィー法（ＧＣ法）は、ＧＣ−１７Ａ（島津製作所製）を用い測定される。試料は、予めトルエンに１重量％濃度で溶解された溶液１μｌをオンカラムインジェクターを備えたＧＣ装置に注入する。カラムは、０．５ｍｍ径×１０ｍ長のＵｌｔｒａ Ａｌｌｏｙ−１（ＨＴ）を用いる。カラムは初め４０℃から４０℃／ｍｉｎ．の昇温スピードで２００℃迄昇温させ、更に１５℃／ｍｉｎ．で３５０迄昇温させ、次に７℃／ｍｉｎ．の昇温スピードで４５０℃迄昇温させる。キャリアガスは、Ｈｅガスを５０ｋＰａの圧力条件で流す。そして、得られるピーク面積比より、求める物質の含有量を算出する。
【００６６】
本発明で好ましく用いられるエステルワックスは、硬度０．５〜５．０を有するものが好ましい。エステルワックスの硬度は、直径２０ｍｍφで、厚さが５ｍｍの円筒形状のサンプルを作製した後、例えば島津製作所製ダイナミック超微小硬度計（ＤＵＨ−２００）を用いビッカース硬度を測定した値である。測定条件は、０．５ｇの荷重で負荷速度が９．６７ｍｍ／秒の条件で１０μｍ変位させた後１５秒間保持し、得られた打痕形状を測定しビッカース硬度を求める。硬度が０．５未満のエステルワックスでは定着器の圧力依存性及びプロセススピード依存性が大きくなり、耐高温オフセット効果の発現が不十分となりやすく、他方５．０を超える場合ではトナーの保存安定性に乏しく、エステルワックス自身の自己凝集力も小さいために耐高温オフセットが不十分となりやすい。具体的化合物としては、下記化合物が挙げられる。
【００６７】
【化１３】

【００６８】
【化１４】

【００６９】
【化１５】

【００７０】
【化１６】

【００７１】
本発明においては上記ワックスが凝集阻害を生じ、且つ離型効果も及ぼすので、トナー中に５〜２５ｗｔ％含有されていることが好ましい。該ワックスの含有量が５ｗｔ％未満であると、本発明の効果が十分発揮されず、若干の着色力低下が生じる。また、該ワックスの含有量が２５ｗｔ％を超えると、顔料の凝集阻害が始まってしまい、トナー外へ顔料が飛び出すという現象が飛び出すという現象が生じる。
【００７２】
本発明の更なる特徴としては重合性単量体を媒体中直接重合してトナーを得ることである。
【００７３】
重合法は、例えば特公昭３６−１０２３１号公報、特公昭４３−１０７９９号公報及び特公昭５１−１４８９５号公報等に提案されているように、重合法においては重合性単量体・着色剤・重合開始剤更に必要に応じて架橋剤・荷電制御剤・その他添加剤を、均一に溶解または分散せしめて単量体組成物とした後、この単量体組成物を分散安定剤を含有する連続相、例えば水相中に適当な撹拌機を用いて分散し、同時に重合反応を行わせ、所望の粒径を有する現像剤を得る方法である。
【００７４】
水系媒体中直接重合すると、着色剤や帯電制御剤等は単量体へ均一に溶解した後トナーとなるため、着色剤の表面への露出が抑えられ、トナー表面においては粉砕法より均一な帯電挙動を示すようになる。
【００７５】
加えて本発明の着色剤とサリチル酸金属化合物を重合性単量体中で分散すると、他の黄色着色剤と比較して単量体中の分散が特に安定しているために、同一の着色力を得るために必要な着色剤の添加量が少なくても良く、結果として透明性により優れた、シャープな帯電を有するトナーを得られる。
【００７６】
また、粉砕法においては、コールターカウンターにより測定した粒度が９μｍ以下になるに従い、従来では問題にならなかった使用原材料の均一分散性や効率の高い粉砕性、更にはシャープな粒度分布に現像剤を分級することが極めて難しくなる傾向にあるが、本発明の着色剤とサリチル酸金属化合物を重合法に用いた場合はその点でも優れた特性を有し、更に従来の粉砕法では使用することができなかった低軟化点物質を多量に使用することができる等、材料の選択幅が広がる等の特徴を有していることからも好ましい。
【００７７】
本発明の顔料を重合法によって添加する場合、本発明の化合物（Ｉ）の重合性単量体中での解砕を容易にするために、単量体中に予め分散しておく前の顔料の粒度としてトナー中での分散粒径に近い本発明の範囲に入っていることが好ましく、具体的には化合物（Ｉ）のアルコール系有機溶媒中での粒度分布が個数平均径にして０．０１〜０．５０μｍであることが好ましく、より好ましくは０．０１〜０．３０μｍであることが良い。
【００７８】
尚、本発明におけるアルコール系有機溶媒中での粒度分布は、具体的に下記の方法で測定した。
【００７９】
測定装置としてはコールターカウンターＬＳ型（コールター社製）を用い、エタノール中へ約濃度２０〜４００ｐｐｍとなるように顔料添加溶液を調製し、超音波洗浄機（ｉａｃｈｉ製 ＶＳ−１５０）で６０秒分散後に測定して得た個数分布値を算出した。それから本発明に係る個数分布から求めた個数基準の長さ平均粒径（Ｄ１）を求めた。
【００８０】
重合法による直接トナーを得る方法においては、公知の単量体が好ましく用いられる。具体的にはスチレン，ｏ（ｍ−，ｐ−）−メチルスチレン，ｍ（ｐ−）−エチルスチレン等のスチレン系単量体；（メタ）アクリル酸メチル，（メタ）アクリル酸エチル，（メタ）アクリル酸プロピル，（メタ）アクリル酸ブチル，（メタ）アクリル酸オクチル，（メタ）アクリル酸ドデシル，（メタ）アクリル酸ステアリル，（メタ）アクリル酸ベヘニル，（メタ）アクリル酸２−エチルヘキシル，（メタ）アクリル酸ジメチルアミノエチル，（メタ）アクリル酸ジエチルアミノエチル等の（メタ）アクリル酸エステル系単量体；ブタジエン，イソプレン，シクロヘキセン，（メタ）アクリロニトリル，アクリル酸アミド等のエン系単量体が好ましく用いられる。これらは、単独または一般的には出版物ポリマーハンドブック第２版ＩＩＩ−Ｐ１３９〜１９２（Ｊｏｈｎ Ｗｉｌｅｙ＆Ｓｏｎｓ社製）に記載の理論ガラス温度（Ｔｇ）が、４０〜８５℃を示すように単量体を適宜混合し用いられる。理論ガラス転移温度が４０℃未満の場合には、トナーの保存安定性やトナーの耐久安定性の面から問題が生じ、一方８５℃を超える場合は定着点の上昇をもたらし、特にフルカラートナーの場合においては各色トナーの混色が不十分となり色再現性に乏しく、更にＯＨＰ画像の透明性を著しく低下させ高画質の面から好ましくない。
【００８１】
本発明の粉砕法を用いた場合、結着樹脂としては上記の単量体成分を組み合わせたスチレン−アクリル系樹脂やマレイン酸共重合体，ポリエステル樹脂，エポキシ樹脂等公知の材料が使用できるが、粉砕法の場合、本発明との分散性の維持や帯電性等のためにポリエステル樹脂を用いることが好ましい。
【００８２】
重合した樹脂の分子量は、ＧＰＣ（ゲルパーミエーションクロマトグラフィー）により測定される。具体的なＧＰＣの測定方法としては、予めトナーをソックスレー抽出器を用いトルエン溶剤で２０時間抽出を行った後、ロータリーエバポレーターでトルエンを留去せしめ、更に低軟化点物質は溶解するが樹脂は溶解し得ない有機溶剤例えばクロロホルム等を加え十分洗浄を行った後、ＴＨＦ（テトラヒドロフラン）に可溶した溶液をポア径が０．３μｍの耐溶剤性メンブランフィルターでろ過したサンプルをウォーターズ社製１５０Ｃを用い、カラム構成は昭和電工製Ａ−８０１、８０２、８０３、８０４、８０５、８０６、８０７を連結し標準ポリスチレン樹脂の検量線を用い分子量分布を測定し得る。得られた樹脂成分の数平均分子量（Ｍｎ）は、５０００〜１，０００，０００であり、重量平均分子量（Ｍｗ）と数平均分子量（Ｍｎ）の比（Ｍｗ／Ｍｎ）は、２〜１００を示す樹脂が本発明には好ましい。
【００８３】
本発明においては、樹脂中に低軟化点物質を内包化せしめるため単量体成分の他に更に極性樹脂を添加せしめても良い。本発明に用いられる極性樹脂としては、スチレンと（メタ）アクリル酸の共重合体，マレイン酸共重合体，飽和ポリエステル樹脂，エポキシ樹脂が好ましく用いられる。
【００８４】
本発明においては、離型作用を付与するため樹脂中に低軟化点物質を添加せしめてもよい。
【００８５】
本発明に用いられる低軟化点物質としては、ＡＳＴＭ Ｄ３４１８−８に準拠し測定された主体極大ピーク値が５０〜１８０℃を示す化合物が好ましい。極大ピーク値が５０℃未満であると低軟化点物質の自己凝集力が弱くなり、結果として耐高温オフセット性が弱くなり特にフルカラートナーには好ましくない。一方、極大ピーク値が１８０℃を超えると、現状のところ軟化点物質の結晶性・分散性が劣化するため定着性・透明性の面から好ましくない。
【００８６】
本発明の極大ピーク値の温度の測定には、例えばパーキンエルマー社製ＤＳＣ−７を用いる。装置検出部の温度補正はインジウムと亜鉛の融点を用い、熱量の補正についてはインジウムの融解熱を用いる。サンプルはアルミニウム製パンを用い対照用には空パンをセットし、昇温速度１０℃／ｍｉｎ．で測定を行う。
【００８７】
具体的にはパラフィンワックス，ポリオレフィンワックス，フィッシャートロピッシュワックス，アミドワックス，エステルワックス，高級脂肪酸及びこれらのグラフト／ブロック化合物等が利用できる。
【００８８】
本発明のサリチル酸金属化合物に加え、本発明に更に荷電制御剤を添加しても良い。荷電制御剤としては、公知のものが利用できるが、無色でトナーの帯電スピードが速く且つ一定の帯電量を安定して維持できる荷電制御剤が好ましい。更に本発明において直接重合法を用いる場合には、重合阻害性が無く水系への可溶化物の無い荷電制御剤が特に好ましい。具体的化合物としては、ネガ系としてナフトエ酸，ダイカルボン酸の金属化合物、スルホン酸、カルボン酸を側鎖に持つ高分子型化合物、ホウ素化合物、尿素化合物、ケイ素化合物、カリークスアレーン等が利用でき、ポジ系として四級アンモニウム塩、該四級アンモニウム塩を側鎖に有する高分子型化合物、グアニジン化合物、イミダゾール化合物等が好ましく用いられる。該荷電制御剤は樹脂１００重量部に対し０．５〜１０重量部が好ましい。しかしながら、本発明において荷電制御剤の添加は、すでにサリチル酸金属化合物が添加されているために必須ではなく、二成分現像方法を用いた場合においては、キャリヤーとの摩擦帯電を利用し、非磁性一成分ブレードコーティング現像方法を用いた場合においてもブレード部材やスリーブ部材との摩擦帯電を積極的に利用することでトナー中に必ずしも荷電制御剤を含む必要はない。
【００８９】
本発明に直接重合法を利用する場合には、重合開始剤として例えば、２，２’−アゾビス−（２，４−ジメチルバレロニトリル）、２，２’−アゾビスイソブチロニトリル、１，１’−アゾビス（シクロヘキサン−１−カルボニトリル）、２，２’−アゾビス−４−メトキシ−２，４−ジメチルバレロニトリル、アゾビスイソブチロニトリル等のアゾ系又はジアゾ系重合開始剤；ベンゾイルペルオキシド、メチルエチルケトンペルオキシド、ジイソプロピルペルオキシカーボネート、クメンヒドロペルオキシド、２，４−ジクロロベンゾイルペルオキシド、ラウロイルペルオキシド等の過酸化物系重合開始剤が用いられる。該重合開始剤の添加量は、目的とする重合度により変化するが一般的には単量体に対し０．５〜２０重量％添加され用いられる。重合開始剤の種類は、重合法により若干異なるが、十時間半減期温度を参考に、単独又は混合し利用される。
【００９０】
重合度を制御するため公知の架橋剤，連鎖移動剤，重合禁止剤等を更に添加し用いることも可能である。
【００９１】
本発明のトナー製造方法に用いる分散剤としては、無機化合物として、リン酸三カルシウム，リン酸マグネシウム，リン酸アルミニウム，リン酸亜鉛，炭酸カルシウム，炭酸マグネシウム，水酸化カルシウム，水酸化マグネシウム，水酸化アルミニウム，メタケイ酸カルシウム，硫酸カルシウム，硫酸バリウム，ベントナイト，シリカ，アルミナ，磁性体，フェライト等が挙げられる。有機化合物として、ポリビニルアルコール，ゼラチン，メチルセルロース，メチルヒドロキシ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スのナトリウム塩，デンプン等を水相に分散させて使用できる。これら分散剤は、重合性単量体１００重量部に対して０．２〜２．０重量部を使用することが好ましい。
【００９２】
これら分散剤は、市販のものをそのまま用いても良いが、細かい均一な粒度を有する分散粒子を得るために、分散媒中にて高速撹拌下にて該無機化合物を生成させることもできる。例えば、リン酸三カルシウムの場合、高速撹拌下において、リン酸ナトリウム水溶液と塩化カルシウム水溶液を混合することで懸濁重合法に好ましい分散剤を得ることができる。
【００９３】
また、これら分散剤の微細化の為に、０．００１〜０．１重量部の界面活性剤を併用してもよい。具体的には市販のノニオン，アニオン，カチオン型の界面活性剤が利用でき、例えば、ドデシルベンゼン硫酸ナトリウム，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，オレイン酸ナトリウム，ラウリル酸ナトリウム，ステアリン酸カリウム，オレイン酸カルシウム等が挙げられる。
【００９４】
本発明のトナー製造方法に直接重合方法を用いる場合においては、以下の如き製造方法によって具体的にトナーを製造することが可能である。
【００９５】
即ち、重合性単量体中に低軟化点物質からなる離型剤，着色剤，サリチル酸金属化合物，荷電制御剤，重合開始剤その他の添加剤を加え、ホモジナイザー，超音波分散機等によって均一に溶解又は分散せしめた単量体系を、分散安定剤を含有する水相中に通常の撹拌機またはホモミキサー，ホモジナイザー等により分散せしめる。好ましくは単量体液滴が所望の現像剤粒子のサイズを有するように撹拌速度，時間を調整し、造粒する。その後は分散安定剤の作用により、粒子状態が維持され、且つ粒子の沈降が防止される程度の撹拌を行えば良い。重合温度は４０℃以上、一般的には５０〜９０℃の温度に設定して重合を行うのが良い。また、重合反応後半に昇温しても良く、更に、現像剤定着時の臭いの原因等となる未反応の重合性単量体、副生成物等を除去するために反応後半、又は、反応終了後に一部水系媒体を留去しても良い。反応終了後、生成した現像剤粒子を洗浄・濾過により回収し、乾燥する。懸濁重合法においては、通常単量体系１００重量部に対して水３００〜３０００重量部を分散媒として使用するのが好ましい。
【００９６】
本発明のトナー製造方法に粉砕法を用いる場合においては、以下の如き製造方法によって具体的にトナーを製造することが可能である。
【００９７】
結着樹脂の一部、本発明の着色剤および本発明のサリチル酸金属化合物を予め３本ロール等により混練し、マスターバッチを得る。そしてこのマスターバッチに所定の結着樹脂、離型剤およびその他の添加剤を加えて希釈混練し、粉砕、分級工程を得た後に所望のトナー粒子を得る。
【００９８】
次に、本発明で用いたそれぞれの測定方法について述べる。
【００９９】
（１）粒度分布の測定
ここで粒度分布については、種々の方法によって測定できるが、本発明においてはコールターカウンタを用いて測定を実施した。
【０１００】
即ち測定装置としては、コールターカウンタＴＡ−ＩＩあるいはコールターマルチサイザーＩＩ（コールター社製）を用いる。電解液は、１級塩化ナトリウムを用いて、約１％ＮａＣｌ水溶液を調製する。例えば、ＩＳＯＴＯＮ−ＩＩ（コールター社製）が使用できる。
【０１０１】
測定方法としては、前記電解水溶液１００〜１５０ｍｌ中に分散剤として界面活性剤、好ましくはアルキルベンゼンスルホン酸塩を０．１〜５ｍｌ加え、更に測定試料を２〜２０ｍｇ加える。
【０１０２】
試料を懸濁した電解液は、超音波分散器で約１〜３分間分散処理を行い、前記測定装置により、アパーチャーとして１００μｍアパーチャーを用いて、トナーの体積、個数を測定して体積分布と個数分布を算出した。
【０１０３】
それから本発明に係る体積分布から求めた重量基準の重量平均粒径（Ｄ４）（各チャンネルの代表値をチャンネル毎の代表値とする）、及び変動係数を求めた。
【０１０４】
（２）低光沢画像の色彩評価方法
トナー７重量部に対し、アクリル樹脂コーティングされたフェライトキャリア９３重量部を混合し、現像剤とする。
【０１０５】
得られた現像剤を用いて、定着温度を可変とし、上下ローラー材質をフッ素系とし、定着オイル塗布機構を省くよう改造したキヤノン製フルカラー複写機ＣＬＣ５００改造機にて、潜像を転写材上に転写し、画像を得た。
【０１０６】
このとき定着条件は転写材として光沢度４の秤量９９ｇ／ｍ^２紙を用い、トナーのり量０．５〜０．７ｍｇ／ｃｍ^２の単色ベタ画像を得て、該画像を光沢度１０〜１５になるよう定着温度を調整した。
【０１０７】
また各色の濃度条件は、コダック社製のグレースケールとカラーパッチを原稿とし、フルカラーコピー画像でグレースケールがなるべく忠実に再現できるようう調整し、イエロー（Ｙ）単色コピーの最高濃度が１．１以上となるように濃度調節した。
【０１０８】
そして上記状態のキヤノン製フルカラー複写機ＣＬＣ５００改造機で、イエロー（Ｙ）・シアン（Ｃ）の重ね合わせ画像であるグリーン（Ｇ）について光沢度１５〜２０の定着条件で出し、このとき各色の最高濃度で重なり合った部分をコダック社製のカラーパッチとの色調差で評価した。
【０１０９】
評価については５段階で行い、画像の明度Ｌ^＊、彩度Ｃ^＊、色相角ｈ^＊についてＣＭＣ（１：１）の色度差式を導入し、比較例１の値を１００としたとき
【０１１０】
【数１】
ΔＥ＞１１０＝×
１００＜ΔＥ≦１１０＝△×
９０＜ΔＥ≦１００＝△
７０＜ΔＥ≦ ９０＝○△
ΔＥ≦ ７０＝○ （ΔＥ：色度差）
と評価した。
【０１１１】
ＣＭＣの式とはＪｏｕｒｎａｌ ｏｆ ｔｈｅ Ｓｏｃｉｅｔｙ ｏｆ Ｄｙｅｒｓ ａｎｄ Ｃｏｌｏｕｒｉｓｔｓ，１００ １２８（１９８４）に提案されている色度式で明度Ｌ^＊、彩度Ｃ^＊、色相角ｈ^＊に視感の補正を加えて評価するものであり、下記式で示される。
ΔＥ＝［（ΔＬ^＊／ＩＳＬ）^２＋（ΔＣ^＊／ｃＳｃ）^２＋（ΔＨ^＊／ＳＨ）^２］^１／２
（ＩＳＬ：明度ΔＬ^＊に対する補正係数、ｃＳｃ：彩度ΔＣ^＊に対する補正係数、ＳＨ：色相角ΔＨ^＊に対する補正係数）
【０１１２】
またその非画像部の反射率より、白紙を測定したときの反射率を差し引いたものをカブリ反射率としカブリ濃度として評価した。ここで反射率の測定にはＴＣ−６ＤＳ（東京電色製）を用いた。
【０１１３】
（３）トランスペアレンシー透過画像評価方法
トランスペアレンシー画像の透過率は以下の如く評価する。
【０１１４】
市販のフルカラー複写機（ＣＬＣ５００；キヤノン社製）改造機を使用して、トランスペアレンシーシート上（ＣＧ３３００：３Ｍ製）に温度２３度／湿度６５％ＲＨの環境下で、現像コントラスト３２０Ｖにて現像転写し、階調を有する未定着トナー画像を得た。得られたものを、定着ローラーの表面がフッ素系樹脂である外部定着器（オイル塗布機能なし；ローラー径４０φ）にて、定着温度１８０度、プロセススピード３０ｍｍ／ｓｅｃで、定着画像を得た。
【０１１５】
得られた定着画像の画像濃度０．４〜０．６の箇所の透過率を測定した。
【０１１６】
透過率の測定は、島津自己分光光度計ＵＶ２２００（島津製作所社製）を使用し測定した。そして、トランスペアレンシーシート単独の透過率を１００％とし、６００ｎｍでの最大吸収波長における透過率を測定した。
【０１１７】
なお、下記の基準で評価した。
○： 透過率が８０％以上
○△：透過率が６５％以上８０％未満
△ ：透過率が５０％以上６５％未満
× ：透過率が５０％未満
【０１１８】
また、透過光の色空間測定については、得られた画像をオーバーヘッドプロジェクター（ＯＨＰ：３Ｍ社製 ９５５０）にて透過画像とし、白色壁面に投影した画像を分光放射輝度計（フォトリサーチ社製 ＰＲ６５０）にて測定した。
【０１１９】
そしてその白色壁面に投影した画像の色相角ｈ^＊（ＯＨＰ）と先の紙上におけるベタ部の色相角ｈ^＊（紙）との角度差Δｈ^＊を、下記に示すように定義し５段階評価で示した。
【０１２０】
【数２】
Δｈ^＊＞３０＝×
２０＜Δｈ^＊≦３０＝△×
１０＜Δｈ^＊≦２０＝△
５＜Δｈ^＊≦１０＝○△
Δｈ^＊≦ ５＝○ （Δｈ^＊：色度差）
と評価した。
【０１２１】
【実施例】
以下実施例に基づいて、本発明を具体的に説明する。尚、以下の配合における部数は特に記載がない限り重量部である。
【０１２２】
＜実施例１＞
０．１ＭのＮａ_３ＰＯ_４水溶液と１ＭのＣａＣｌ_２水溶液を用意する。高速撹拌装置ＴＫ式ホモミキサーを備えた２リットル用四つ口フラスコ中に、イオン交換水７１０部と０．１Ｍ−Ｎａ_３ＰＯ_４水溶液５５０部を添加し、回転数を１００００ｒｐｍに調整し、６５℃に加温せしめた。ここに１ＭのＣａＣｌ_２水溶液６８部を徐々に添加し、微小な難水溶性分散剤Ｃａ_３（ＰＯ_４）_２を含む分散媒系を調製した。
【０１２３】
一方、分散質系は、
スチレン単量体 １６０部
ｎ−ブチルアクリレート単量体 ４０部
着色剤［化合物（Ｉ）；個数平均径０．０６μｍ］ ５部
飽和ポリエステル １０部
（テレフタール酸−プロピレンオキサイド変性ビスフェノールＡ
酸価８，ピーク分子量；７０００）
サリチル酸アルミ化合物 ３部
エステルワックス［化合物（４）；極大ピーク値６４．４℃］ ２０部
上記混合物をアトライターを用いて３時間分散させた後、重合開始剤である２，２’−アゾビス（２，４’−ジメチルバレロニトリル）２部を添加し分散物を分散媒体中に投入し回転数を維持しつつ８分間造粒した。その後高速撹拌器からプロペラ撹拌羽根に撹拌器を変え５０回転で撹拌しつつ内温を６０℃で４時間、その後８０℃に昇温させ４時間重合を計８時間継続させた。重合終了後スラリーを冷却し、希塩酸を添加し分散剤を除去せしめた。
【０１２４】
更に洗浄し乾燥を行うことで、コールターカウンターで測定したイエロートナーの重量平均径は６．６μｍで、個数変動係数が２４％であった。
【０１２５】
得られたトナーに疎水化処理酸化チタンを２％外添し、流動性に優れたトナーを得、このトナー７部に対し、アクリル樹脂コーティングされたフェライトキャリア９３部を混合し現像剤とし、キヤノン製フルカラー複写機ＣＬＣ５００改造機にて光沢１５の画像及びトランスペアレンシー画像を得て、その評価を行った。
【０１２６】
すると紙上の画像とトランスペアレンシー透過画像との間に色相角の変化はほとんどなく、ＯＨＰ透明性にも優れたものであった。
【０１２７】
また、顔料をＣ．Ｉ．Ｐｉｇ．Ｂ１５：３ ６部に変更した他は同様の方法でシアントナーを製造し、上記イエロートナーと共に二次色であるグリーンの再現性も確認したところ、鮮明なグリーン画像が得られた。
【０１２８】
＜比較例１＞
実施例１の処方の中で、着色剤を化合物（Ｉ）からＣ．Ｉ．Ｐｉｇ．Ｙ８３ ７部に変更した他は全て実施例１と同様にして、イエロートナーを製造した。
【０１２９】
＜実施例２＞
実施例１の処方の中で、サリチル酸アルミ化合物の処方量を３部から０．２部に変更した他は全て実施例１と同様にして、イエロートナーを製造した。
【０１３０】
＜実施例３＞
プロポキシ化ビスフェノールとフマル酸、トリメリット酸を縮合して得られたポリエステル樹脂（Ｍｎ＝２５００，Ｍｗ＝２１０００，Ｔｇ＝５９℃，酸価＝９）１００部に対して、
化合物（Ｉ） ５部
サリチル酸アルミ化合物 ２部
エステルワックス（極大ピーク値６９．４℃） ２部
を加えて溶融・混練・粉砕・分級しイエロー粒子を得た。該イエロー粒子の重量平均径は６．７μｍで個数変動係数が３８％であった。
【０１３１】
＜参考例＞
実施例１の処方の中で、着色剤を粒径０．６０μｍに伸張させた化合物（Ｉ）に変更した他は総て実施例１と同様にして、イエロートナーを製造した。
【０１３２】
＜実施例４＞
実施例１の処方の中で、サリチル酸アルミ化合物をサリチル酸亜鉛化合物に変更した他は総て実施例１と同様にして、イエロートナーを製造した。
【０１３３】
下記に各トナーの特性とその評価を示す。
【０１３４】
【表１】

【０１３５】
【発明の効果】
本発明によれば、光沢度の低い画像上で鮮明な色彩が得られ、かつバランスの取れた色相及び優れたトランスペアレンシー透過性を有している画像を得ることができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a yellow toner for developing an electrostatic image formed in an electrophotographic method, an electrostatic printing method, and the like, and a method for manufacturing the same. More specifically, the present invention relates to a yellow toner obtained by polymerizing a monomer composition containing at least a yellow colorant, and a method for producing the same.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, digital full-color copying machines and printers have been put to practical use, and high-quality images excellent in color reproducibility without color unevenness as well as in resolving power and gradation can be obtained.
[0003]
In a digital full-color copying machine, a color image original is color-separated by B (blue), G (green), and R (red) color filters, and then a latent image having a dot diameter of 20 μm to 70 μm corresponding to the original image is formed. Developing using the subtractive color mixing action using Y (yellow), M (magenta), C (cyan), and B (black) color developers, but a larger amount of developer is transferred from the photoreceptor compared to a black and white copying machine In order to cope with the necessity of transferring to a material and to achieve higher image quality in the future, a demand for a finer particle size of a developer corresponding to finer dots is expected.
[0004]
However, if the particle size of the toner is reduced in accordance with the demand for higher image quality, the resolution and the sharpness of a full-color image will certainly be in a satisfactory direction, but it has been found that there are various effects as the particle size decreases.
[0005]
In addition, the smaller the toner particle size, the more the colorant is unevenly distributed, which causes a problem that the charging characteristics are easily affected.
[0006]
Therefore, there is a demand for a toner having better dispersion of each color of the color toner than before and having well-balanced hue and spectral reflection characteristics and sufficient saturation.
[0007]
Further, when the toner particle diameter is reduced, light becomes more liable to be scattered, so that the chromaticity, lightness, density, and the like of the image change, which causes a problem that a color configuration different from that of the related art is required. come.
[0008]
This becomes remarkable when an image is obtained in accordance with a new user orientation accompanying the spread of printers in recent years, that is, a tendency to prefer an image similar to other matte printed matter such as photoengraving printing.
[0009]
That is, according to the conventional technology, it is necessary that the fixed toner is in a state close to almost complete melting so that the shape of the toner particles cannot be discriminated so that the fixed toner does not irregularly reflect light and hinder color reproduction. In a color image in which different types of toner layers are superimposed, the upper toner layer needs to have transparency that does not interfere with the lower toner layer.
[0010]
Based on this idea, it is disclosed in JP-A-59-26557, JP-A-63-70271, JP-A-230072, JP-A-2-293860, JP-A-6-11898 and the like. Various configurations of yellow / magenta / cyan / black and others have been proposed.
[0011]
However, in order to obtain an image having no difference in gloss from other printed matter such as photoengraving printing, it is necessary to fix the gloss to a value close to the glossiness of the paper. Therefore, the influence of the scattered light of the fine particle toner becomes remarkable, and the color space configuration of the above-mentioned invention has become insufficient.
[0012]
Further, if the resin of the toner is designed such that the toner particles are not completely melted, the transmitted light is scattered because the toner particles cannot be completely melted even on the transparency film, and the color reproduction area is reduced. It turned out to be smaller.
[0013]
Further, it has been found that the hue angle also changes, so that it becomes impossible to obtain a desired color.
[0014]
In particular, for yellow, human sensitivity to a change in hue angle is remarkable, so that a change in color angle of transmitted light is not preferred.
[0015]
In the printer market, there are many machines that output images containing mixed black characters.However, in the conventional technology, there is a difference in the amount of toner applied between the black characters and the color image, resulting in a difference in gloss. As a result, a color image with high glossiness appears to "emerge".
[0016]
Further, it has been found that fog becomes noticeable when the coloring power of the toner is increased as a countermeasure because the light on the image surface is scattered and the image density is reduced.
[0017]
That is, since the portion where the toner is scattered at the time of fixing is given a relatively sufficient amount of heat, the glossiness of the image is increased, and as a result, the image density of the scattered portion is increased. And this makes the fog noticeable.
[0018]
As described above, at present, there is no color toner that can satisfy all of the various problems necessary for obtaining a glossless printed matter.
[0019]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a yellow toner capable of solving the above-mentioned disadvantages and obtaining a very clear color on an image having a low glossiness, and a method for producing the same.
[0020]
That is, an object of the present invention is to provide a toner having a well-balanced hue at a low gloss level and excellent transparency and a method for producing the same.
[0021]
It is another object of the present invention to provide a yellow toner used for a full-color image having a uniform image quality without any discomfort even in an image including black characters, and a method of manufacturing the same.
[0022]
Another object of the present invention is to provide a yellow toner having excellent chargeability and a method for producing the same.
[0023]
[Means for Solving the Problems]
The present inventionAt least a yellow colorant represented by the following structural formula, by polymerizing a polymerizable monomer system containing a metal salicylate compound and a polymerizable monomer, obtained by directly producing toner particles,
The yellow colorant before being contained in the polymerizable monomer system shows a particle size distribution in which the number average diameter is 0.01 to 0.50 μm in the alcoholic organic solvent, and the number average diameter of the colorant in the toner particles Is 0.01 to 0.70 μm,
Binder resin,Contains at least a yellow colorant and a metal salicylate compoundWith toner particlesAnd a yellow toner.
[0024]
Embedded image

[0025]
As a result of intensive studies, the present inventor has made a toner into an excellent dispersion state that has not been obtained conventionally by using a specific metal compound as a dispersant for the colorant of the present invention having excellent color developing properties and transparency. They have found that they can be obtained even in the state, and have reached the present invention.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
One of the features of the present invention is to use the colorant compound (I) which has excellent transparency and dispersibility of the colorant itself.
[0027]
The coloring agent of the present invention is generally C.I. I. Pig. It is a colorant classified as Yellow166, and exhibits excellent coloring power when added in an amount of 2 to 8 parts by weight based on 100 parts by weight of the toner binder resin.
[0028]
In addition, the coloring agent of the present invention can be combined with other conventionally known coloring agents for improving tint, but is preferably added within a range that does not impair the transparency of the coloring agent of the present invention. It is preferably less than 20 parts by weight based on 100 parts by weight of the coloring agent of the present invention.
[0029]
In addition, the present inventor has studied conditions under which the hue angle does not change most in transmitted light of a transparency image whose surface is not completely melted, and as a result, selects a colorant having a certain primary particle size. It has been found that it can be suppressed to some extent.
[0030]
Conventionally, from this viewpoint, for example, JP-A-4-342265 describes the primary particle size of a quinacridone pigment, and JP-A-4-204547 discloses a carbon black as an example for the purpose of giving gradation. Is described.
[0031]
However, when the present invention is simply applied to a transparency image whose surface is not completely melted as in the present invention, the hue angle and color gamut are changed, particularly in yellow transmitted light, although it is suppressed as compared with the related art.
[0032]
That is, in the present invention, the transparency of the pigment itself is indispensable from the above viewpoint, and the colorant of the present invention is also excellent in that the pigment has transparency and that the dispersion state is easily controlled to a fine particle size. Demonstrate the characteristics.
[0033]
In the present invention, the primary particle size of the compound (I) is preferably 0.01 to 0.70 μm, preferably 0.01 to 0.40 μm, and more preferably 60% as a variation coefficient of the particle size distribution. The following is preferred.
[0034]
When the primary particle size of the compound (I) is less than 0.01 μm, not only the light resistance of the compound (I) is extremely lowered, but also the handling property and the charging property during production are adversely affected.
[0035]
If the primary particle size of the compound (I) is 0.70 μm and the variation coefficient of the particle size distribution exceeds 60%, aggregation of the colorant is likely to occur at the time of production, and the hue angle of the transmitted light of the transparency image. -The color gamut changes from that on paper. Also, the transmitted image becomes dark.
[0036]
In addition, the particle size of the colorant in the present invention is specifically measured by the following method.
[0037]
First, after sufficiently dispersing the toner in a room-temperature curable epoxy resin, the cured product is cured in an atmosphere at a temperature of 40 ° C. for 2 days, and the cured product is dyed using ruthenium tetroxide and, if necessary, osmium tetroxide in combination. After the application, a flaky sample was cut out using a microtome provided with diamond teeth, and the tomographic morphology of the toner was measured using a transmission electron microscope (TEM).
[0038]
Then, 100 obtained toner cross-sectional images were randomly sampled, and the image information was introduced into an image analyzer (Luzex3) manufactured by Nicole via an interface, analyzed, and the value obtained as the particle size distribution was used as the colorant value. The primary particle size was used.
[0039]
Another feature of the present invention is the use of a metal salicylate compound as a specific colorant dispersant.
[0040]
The colorant of the present invention is characterized in that its particle size can be easily controlled.However, from the viewpoint of compatibility of the toner binder resin and the release agent, and the chargeability of the toner, it causes re-aggregation and poor chargeability. This tends to be insufficient and is not always sufficient when used as toner.
[0041]
On the other hand, as a conventional technique for improving dispersibility, for example, a so-called flushing method described in JP-A-2-175770, and a surface treatment of a pigment as disclosed in JP-A-5-247370 are performed. Many methods and methods have been disclosed, but these methods are still insufficient in view of versatility for controlling the toner charging property to an appropriate range, simplification of the process, and the like.
[0042]
Then, the present inventor studied a substance capable of controlling the chargeability together with the action of the dispersion improving additive suitable for the colorant of the present invention, and reached the present invention.
[0043]
As the metal salicylate compound of the present invention, a complex and / or a complex salt containing aluminum, chromium, zinc, and iron as a central metal is preferable. Most preferred.
[0044]
As a means for adding and improving the salicylic acid metal compound to the pigment of the present invention, known means such as forming a master batch in advance can be used. In order to obtain both, it is preferable to add them in a ratio of 10 to 400 parts by weight, more preferably 10 to 100 parts by weight, based on 100 parts by weight of the pigment.
[0045]
As a further feature of the present invention, a specific ester wax is added as a release agent having the function of the colorant dispersing aid of the present invention.
[0046]
This is thought to be caused by the fact that the ester group in the wax has an affinity for the functional group of the pigment having the structure of the present invention, so that the pigment is incorporated into the hydrophobic wax and buried in the toner. .
[0047]
Therefore, in the present invention, an improvement in chargeability is achieved by combining a wax having an ester group with the pigment of the present invention.
[0048]
As a result of examination from that viewpoint, the wax of the present invention preferably has one or more long-chain ester moieties having 15 or more carbon atoms, and more preferably 15 to 30 carbon atoms.
[0049]
If the number of carbon atoms is less than 15, the surface of the pigment is modified, but the colorant is easily transferred to the surface of the fixing roller due to the calorific value of the fixing device. Decreases roller durability.
[0050]
When the number of carbon atoms exceeds 30, the plasticizing effect of the wax on the resin becomes too large, and the fixability decreases. Also, the transparency deteriorates.
[0051]
In recent years, the necessity of full-color double-sided images has been increasing, and when forming a double-sided image, the toner image on the transfer paper formed first on the front side is also used for forming the image on the rear side. There is a possibility that the toner passes through the heating section again, and it is necessary to sufficiently consider the high-temperature offset resistance of the toner. Therefore, in the present invention, it is necessary to add a large amount of ester wax.
[0052]
For this reason, the ester wax of the present invention needs to impart releasability / transparency in addition to modifying the pigment, and it is preferable to add 5 to 30% by weight of the ester wax to the toner.
[0053]
If the addition is less than 5% by weight, sufficient reforming property is not exhibited, and the image on the back side tends to show an offset phenomenon at the time of fixing a double-sided image.
[0054]
On the other hand, when the content exceeds 30% by weight, in the production of the toner, for example, in the production, fusion of the device and fusion of the toner are apt to occur, and the impact resistance to the drum is reduced, so that filming is liable to occur.
[0055]
As a means for adding and modifying the ester wax to the pigment of the present invention, known means such as forming a master batch in advance can be used. Therefore, it is preferable to add the ester wax at a ratio of 100 to 3000 parts by weight to 100 parts by weight of the metal salicylate and the pigment of the present invention at the time of addition.
[0056]
In the present invention, as the ester wax to be used, a compound having a main maximum peak value of 40 to 90 ° C. measured according to ASTM D3418-8 is preferable. If the maximum peak is less than 40 ° C., the self-cohesive force of the low softening point substance becomes weak, and as a result, the high temperature offset resistance becomes weak, which is not preferable for a full color toner. On the other hand, when the maximum peak exceeds 90 ° C., the fixing temperature becomes high, and it becomes difficult to appropriately smooth the surface of the fixed image, which is not preferable from the viewpoint of color mixing.
[0057]
For the measurement of the temperature of the maximum peak value of the present invention, for example, DSC-7 manufactured by Perkin Elmer Co., Ltd. is used. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of the calorific value uses the heat of fusion of indium. As a sample, an aluminum pan was used, an empty pan was set as a control, and measurement was performed at a heating rate of 10 ° C./min.
[0058]
The structural formulas of typical compounds of the specific ester waxes preferred for the present invention are shown below as general structural formulas (1) to (5).
[0059]
Embedded image

(A and b each represent an integer of 0 to 4; the sum of a and b is 4;
R₁And R₂Represents an organic group having an integer of 1 to 40 carbon atoms, and R₁And R₂
Has a carbon number difference of 3 or more,
m and n each represent an integer of 0 to 25, and m and n do not become 0 at the same time. )
[0060]
Embedded image

(A and b each represent an integer of 0 to 3, and the sum of a and b is 1 to 3,
R₁And R₂Represents an organic group having an integer of 1 to 40 carbon atoms, and R₁And R₂
Has a carbon number difference of 3 or more,
R₃Represents a hydrogen atom or an organic group having 1 or more carbon atoms, provided that the sum of a and b
Is 2, R₃At least one of them has an organic group having 1 or more carbon atoms.
Show,
k represents an integer of 1 to 3,
m or n represents an integer of 0 to 25, and m and n do not become 0 at the same time. )
[0061]
Embedded image

(R₁And R₃Represents an organic group having 6 to 32 carbon atoms;₁And R₃Are the same
With or without
R₂Represents an organic group having 1 to 20 carbon atoms. )
[0062]
Embedded image

(R₁And R₃Represents an organic group having 6 to 32 carbon atoms;₁And R₃May or may not be the same,
R₂Is -CH₂CH₂OC₆H₄OCH₂CH₂−,
-(CH (CH₃) CH₂O)_m-C₆H₄C (CH₃)₂C₆H₄−
(OCH₂CHCH₃)_mHaving a modified bisphenol skeleton of-
Or (CH₂)_nRepresents-, m represents an integer of 1 to 10, n is 1 to
Indicates an integer of 20. )
[0063]
Embedded image

(A represents an integer of 0 to 4, b represents an integer of 1 to 4, and the sum of a and b is 4
Yes,
R₁Represents an organic group having an integer of 1 to 40 carbon atoms,
m and n each represent an integer of 0 to 25, and m and n do not become 0 at the same time. )
[0064]
In the present invention, the low softening point substance contained in the toner preferably contains, as a main component, a substance represented by any of the above (1) to (5). In the present invention, the term “main component” means that the peak area of the substance of the present invention is 55% or more of the total peak area of all the low softening point substances in the gas chromatography method (GC method) described below. Means that.
[0065]
The gas chromatography method (GC method) is measured using GC-17A (manufactured by Shimadzu Corporation). As a sample, 1 μl of a solution previously dissolved in toluene at a concentration of 1% by weight is injected into a GC device equipped with an on-column injector. The column uses Ultra Alloy-1 (HT) having a diameter of 0.5 mm and a length of 10 m. The column is initially 40 ° C to 40 ° C / min. At a heating rate of 200 ° C., and further at 15 ° C./min. At 350 ° C. and then at 7 ° C./min. The temperature is increased up to 450 ° C. at a temperature increasing speed. As the carrier gas, He gas flows under a pressure condition of 50 kPa. Then, the content of the substance to be obtained is calculated from the obtained peak area ratio.
[0066]
The ester wax preferably used in the present invention preferably has a hardness of 0.5 to 5.0. The hardness of the ester wax is a value obtained by preparing a cylindrical sample having a diameter of 20 mm and a thickness of 5 mm, and then measuring the Vickers hardness using, for example, a dynamic ultra-micro hardness meter (DUH-200) manufactured by Shimadzu Corporation. The measurement conditions are as follows. After a displacement of 10 μm at a load speed of 9.67 mm / sec under a load of 0.5 g and holding for 15 seconds, the resulting dent shape is measured to determine the Vickers hardness. When the ester wax has a hardness of less than 0.5, the pressure dependency and the process speed dependency of the fixing device become large, and the high-temperature offset effect is likely to be insufficiently developed. And the self-cohesive force of the ester wax itself is small, so that the high-temperature offset resistance tends to be insufficient. Specific compounds include the following compounds.
[0067]
Embedded image

[0068]
Embedded image

[0069]
Embedded image

[0070]
Embedded image

[0071]
In the present invention, since the above-mentioned wax causes aggregation inhibition and also exerts a releasing effect, it is preferable that the wax contains 5 to 25% by weight. When the content of the wax is less than 5% by weight, the effect of the present invention is not sufficiently exhibited, and the coloring power is slightly reduced. On the other hand, if the content of the wax exceeds 25 wt%, the aggregation of the pigment starts to be inhibited, and the phenomenon that the pigment jumps out of the toner occurs.
[0072]
A further feature of the present invention is to obtain a toner by directly polymerizing a polymerizable monomer in a medium.
[0073]
The polymerization method is, for example, as proposed in JP-B-36-10231, JP-B-43-10799, and JP-B-51-14895, and the like. A polymerization initiator and, if necessary, a crosslinking agent, a charge control agent, and other additives are uniformly dissolved or dispersed into a monomer composition, and then the monomer composition is continuously mixed with a dispersion stabilizer. This is a method in which a developer having a desired particle size is obtained by dispersing in a phase, for example, an aqueous phase using a suitable stirrer and simultaneously performing a polymerization reaction.
[0074]
When polymerized directly in an aqueous medium, the colorant and charge control agent are uniformly dissolved in the monomer to form a toner, so that exposure of the colorant to the surface is suppressed. Behaves.
[0075]
In addition, when the colorant of the present invention and the metal salicylate compound are dispersed in a polymerizable monomer, the dispersion in the monomer is particularly stable as compared with other yellow colorants, so that the same coloring power is obtained. The amount of the colorant required to obtain the toner may be small, and as a result, a toner having excellent transparency and sharp charge can be obtained.
[0076]
Further, in the pulverization method, as the particle size measured by a Coulter counter becomes 9 μm or less, the developer is dispersed in a uniform particle size and a highly efficient pulverization property, which has not been a problem in the past, and further, a sharp particle size distribution. Although it tends to be extremely difficult to classify, when the colorant of the present invention and the metal salicylate compound are used in the polymerization method, they have excellent properties in that respect, and can be used in the conventional pulverization method. It is also preferable because it has features such as the ability to use a large amount of a low softening point substance that has not been obtained, and a wide selection range of materials.
[0077]
When the pigment of the present invention is added by a polymerization method, in order to facilitate the disintegration of the compound (I) of the present invention in the polymerizable monomer, the pigment before it is previously dispersed in the monomer is used. It is preferable that the particle size of the compound (I) falls within the range of the present invention, which is close to the particle size of the dispersion in the toner. It is preferably from 0.01 to 0.50 μm, more preferably from 0.01 to 0.30 μm.
[0078]
The particle size distribution in the alcohol-based organic solvent in the present invention was specifically measured by the following method.
[0079]
Using a Coulter counter LS type (manufactured by Coulter) as a measuring device, a pigment-added solution was prepared in ethanol so as to have a concentration of about 20 to 400 ppm, and dispersed in an ultrasonic cleaner (VS-150 manufactured by Iachi) for 60 seconds. The number distribution value obtained by the subsequent measurement was calculated. Then, the number-based length average particle diameter (D1) determined from the number distribution according to the present invention was determined.
[0080]
In a method of directly obtaining a toner by a polymerization method, a known monomer is preferably used. Specifically, styrene monomers such as styrene, o (m-, p-)-methylstyrene, m (p-)-ethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, (meth) ) Propyl acrylate, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ( (Meth) acrylate monomers such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate; and ene monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile, and acrylamide. It is preferably used. These monomers are used alone or generally so that the theoretical glass temperature (Tg) described in the published Polymer Handbook, 2nd edition, III-P139-192 (manufactured by John Wiley & Sons) is 40 to 85 ° C. It is used by being appropriately mixed. If the theoretical glass transition temperature is lower than 40 ° C., problems arise in terms of the storage stability of the toner and the durability stability of the toner. In this case, the color mixture of each color toner is insufficient and the color reproducibility is poor, and the transparency of the OHP image is remarkably reduced, which is not preferable from the viewpoint of high image quality.
[0081]
When the pulverization method of the present invention is used, known materials such as a styrene-acrylic resin, a maleic acid copolymer, a polyester resin, and an epoxy resin combining the above monomer components can be used as the binder resin. In the case of the pulverization method, it is preferable to use a polyester resin in order to maintain dispersibility with the present invention, chargeability, and the like.
[0082]
The molecular weight of the polymerized resin is measured by GPC (gel permeation chromatography). As a specific GPC measurement method, the toner is extracted in advance with a toluene solvent using a Soxhlet extractor for 20 hours, and then toluene is distilled off with a rotary evaporator. An organic solvent that cannot be obtained, such as chloroform, was added thereto, washed sufficiently, and a solution obtained by filtering a solution dissolved in THF (tetrahydrofuran) through a solvent-resistant membrane filter having a pore diameter of 0.3 μm was used with a 150C manufactured by Waters Corporation. The column configuration is such that A-801, 802, 803, 804, 805, 806, 807 manufactured by Showa Denko are connected, and the molecular weight distribution can be measured using a standard polystyrene resin calibration curve. The number average molecular weight (Mn) of the obtained resin component is 5,000 to 1,000,000, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2 to 100. The resins shown are preferred for the present invention.
[0083]
In the present invention, a polar resin may be further added in addition to the monomer component in order to incorporate a low softening point substance into the resin. As the polar resin used in the present invention, a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a saturated polyester resin, and an epoxy resin are preferably used.
[0084]
In the present invention, a low softening point substance may be added to the resin in order to impart a releasing effect.
[0085]
As the low softening point substance used in the present invention, a compound having a main maximum peak value of 50 to 180 ° C measured according to ASTM D3418-8 is preferable. When the maximum peak value is less than 50 ° C., the self-cohesive force of the low softening point substance becomes weak, and as a result, the high-temperature offset resistance becomes weak, which is not preferable for a full-color toner. On the other hand, if the maximum peak value exceeds 180 ° C., the crystallinity and dispersibility of the softening point substance are deteriorated at present, which is not preferable in terms of fixability and transparency.
[0086]
For the measurement of the temperature of the maximum peak value of the present invention, for example, DSC-7 manufactured by Perkin Elmer Co., Ltd. is used. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of the calorific value uses the heat of fusion of indium. An aluminum pan was used as a sample, an empty pan was set as a control, and the temperature was raised at a rate of 10 ° C./min. Perform the measurement with.
[0087]
Specifically, paraffin wax, polyolefin wax, Fischer-Tropsch wax, amide wax, ester wax, higher fatty acid, and graft / block compounds thereof can be used.
[0088]
In addition to the metal salicylate compound of the present invention, a charge control agent may be further added to the present invention. As the charge control agent, a known charge control agent can be used, but a charge control agent that is colorless, has a high toner charging speed, and can stably maintain a constant charge amount is preferable. Furthermore, when a direct polymerization method is used in the present invention, a charge control agent having no polymerization inhibition and having no solubilized substance in an aqueous system is particularly preferable. Specific examples of the negative compound include metal compounds of naphthoic acid and dicarboxylic acid, sulfonic acid, polymer compounds having a carboxylic acid in the side chain, boron compounds, urea compounds, silicon compounds, and carricks arenes as negative compounds. A quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in a side chain, a guanidine compound, an imidazole compound, or the like is preferably used as a positive compound. The charge control agent is preferably used in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the resin. However, in the present invention, the addition of the charge control agent is not essential because the metal salicylate compound has already been added. In the case of using the two-component developing method, triboelectric charging with the carrier is used, and non-magnetic particles are added. Even when the component blade coating and developing method is used, it is not always necessary to include a charge control agent in the toner by actively utilizing the triboelectric charging with the blade member and the sleeve member.
[0089]
When the direct polymerization method is used in the present invention, for example, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, Azo or diazo polymerization initiators such as 1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile; benzoyl A peroxide polymerization initiator such as peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, and lauroyl peroxide is used. The amount of the polymerization initiator varies depending on the desired degree of polymerization, but is generally used in an amount of 0.5 to 20% by weight based on the monomer. The type of the polymerization initiator varies slightly depending on the polymerization method, but is used alone or in combination with reference to the 10-hour half-life temperature.
[0090]
In order to control the degree of polymerization, a known crosslinking agent, chain transfer agent, polymerization inhibitor or the like may be further added and used.
[0091]
As the dispersant used in the toner production method of the present invention, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, hydroxide Examples include aluminum, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina, a magnetic substance, and ferrite. As the organic compound, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch and the like can be used by dispersing them in an aqueous phase. It is preferable to use 0.2 to 2.0 parts by weight of these dispersants based on 100 parts by weight of the polymerizable monomer.
[0092]
As these dispersants, commercially available ones may be used as they are, but in order to obtain finely dispersed particles having a uniform particle size, the inorganic compound can also be generated in a dispersion medium under high-speed stirring. For example, in the case of tricalcium phosphate, a dispersant suitable for suspension polymerization can be obtained by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring.
[0093]
Further, in order to make these dispersants finer, a surfactant of 0.001 to 0.1 part by weight may be used in combination. Specifically, commercially available nonionic, anionic, and cationic surfactants can be used, and examples thereof include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, and potassium stearate. , Calcium oleate and the like.
[0094]
When the direct polymerization method is used in the toner production method of the present invention, it is possible to specifically produce the toner by the following production method.
[0095]
That is, a releasing agent comprising a low softening point substance, a coloring agent, a metal salicylate compound, a charge control agent, a polymerization initiator, and other additives are added to the polymerizable monomer, and the mixture is uniformly mixed with a homogenizer, an ultrasonic disperser or the like. The dissolved or dispersed monomer system is dispersed in an aqueous phase containing a dispersion stabilizer using a conventional stirrer, homomixer, homogenizer, or the like. Preferably, the agitation speed and time are adjusted so that the monomer droplets have the desired developer particle size, and granulation is performed. After that, by the action of the dispersion stabilizer, the stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented. The polymerization is preferably performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. Further, the temperature may be raised in the latter half of the polymerization reaction, and further, in order to remove unreacted polymerizable monomers and by-products which cause odor at the time of fixing the developer, the second half of the reaction, or After completion, a part of the aqueous medium may be distilled off. After completion of the reaction, the generated developer particles are collected by washing and filtration, and dried. In the suspension polymerization method, it is generally preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer system.
[0096]
When the pulverization method is used in the toner production method of the present invention, the toner can be specifically produced by the following production method.
[0097]
A part of the binder resin, the colorant of the present invention and the metal salicylate compound of the present invention are kneaded in advance with a three-roll mill or the like to obtain a master batch. Then, a predetermined binder resin, a release agent and other additives are added to the master batch, and the mixture is diluted and kneaded, and after pulverization and classification steps are performed, desired toner particles are obtained.
[0098]
Next, each measurement method used in the present invention will be described.
[0099]
(1) Measurement of particle size distribution
Here, the particle size distribution can be measured by various methods, but in the present invention, the measurement was performed using a Coulter counter.
[0100]
That is, a Coulter Counter TA-II or Coulter Multisizer II (manufactured by Coulter Inc.) is used as a measuring device. As the electrolyte, about 1% NaCl aqueous solution is prepared using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter Inc.) can be used.
[0101]
As a measuring method, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the aqueous electrolytic solution, and 2 to 20 mg of a measurement sample is further added.
[0102]
The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes using an ultrasonic disperser, and the volume and number of the toner are measured by using the measuring device using a 100 μm aperture as an aperture. The distribution was calculated.
[0103]
Then, the weight-based weight average particle diameter (D4) obtained from the volume distribution according to the present invention (the representative value of each channel is taken as the representative value of each channel), and the coefficient of variation were obtained.
[0104]
(2) Color evaluation method for low gloss images
A developer is prepared by mixing 93 parts by weight of an acrylic resin-coated ferrite carrier with 7 parts by weight of the toner.
[0105]
Using the obtained developer, the fixing temperature was made variable, the upper and lower roller materials were made of fluorine, and the latent image was transferred onto the transfer material using a modified Canon full-color copying machine CLC500 modified to eliminate the fixing oil application mechanism. Transfer was performed to obtain an image.
[0106]
At this time, the fixing conditions were as follows.²Using paper, toner amount 0.5 to 0.7 mg / cm²Was obtained, and the fixing temperature was adjusted so that the image had a glossiness of 10 to 15.
[0107]
The density condition of each color is adjusted so that a gray scale and a color patch manufactured by Kodak Co., Ltd. are used as a document and the gray scale is reproduced as faithfully as possible in a full-color copy image. The concentration was adjusted as described above.
[0108]
Then, using a modified full-color copier CLC500 manufactured by Canon in the above state, green (G), which is a superimposed image of yellow (Y) and cyan (C), was output under fixing conditions of glossiness 15 to 20, and the maximum The portions overlapping in density were evaluated by the difference in color tone from a color patch manufactured by Kodak Company.
[0109]
The evaluation was performed in five stages, and the brightness L of the image was^*, Saturation C^*, Hue angle h^*When the chromaticity difference formula of CMC (1: 1) is introduced, and the value of Comparative Example 1 is set to 100,
[0110]
(Equation 1)
ΔE> 110 = ×
100 <ΔE ≦ 110 = △ ×
90 <ΔE ≦ 100 = △
70 <ΔE ≦ 90 = ○ △
ΔE ≦ 70 = ○ (ΔE: chromaticity difference)
Was evaluated.
[0111]
The CMC formula is a chromaticity formula proposed in Journal of the Society of Dyers and Colorists, 100 128 (1984), and the lightness L^*, Saturation C^*, Hue angle h^*Is evaluated by correcting the sensation, and is expressed by the following equation.
ΔE = [(ΔL^*/ ISL)²+ (ΔC^*/ CSc)²+ (ΔH^*/ SH)²]^1/2
(ISL: Lightness ΔL^*Correction coefficient for cSc: saturation ΔC^*Correction coefficient SH: Hue angle ΔH^*Correction factor for
[0112]
Further, a value obtained by subtracting the reflectance at the time of measuring white paper from the reflectance of the non-image portion was evaluated as a fog reflectance and evaluated as a fog density. Here, TC-6DS (manufactured by Tokyo Denshoku) was used for measuring the reflectance.
[0113]
(3) Transparency transmission image evaluation method
The transmittance of the transparency image is evaluated as follows.
[0114]
Using a commercially available full-color copier (CLC500; manufactured by Canon Inc.), a transfer machine is developed and transferred on a transparency sheet (CG3300: 3M) at a development contrast of 320 V under an environment of a temperature of 23 ° C. and a humidity of 65% RH. Thus, an unfixed toner image having a gradation was obtained. A fixed image was obtained from the obtained product using an external fixing device (no oil coating function; roller diameter 40φ) in which the surface of the fixing roller was a fluororesin at a fixing temperature of 180 ° and a process speed of 30 mm / sec.
[0115]
The transmittance of the obtained fixed image at a portion where the image density was 0.4 to 0.6 was measured.
[0116]
The transmittance was measured using a Shimadzu self-spectrophotometer UV2200 (manufactured by Shimadzu Corporation). The transmittance of the transparency sheet alone was set to 100%, and the transmittance at the maximum absorption wavelength at 600 nm was measured.
[0117]
In addition, it evaluated based on the following criteria.
：: transmittance is 80% or more
○ △: transmittance is 65% or more and less than 80%
Δ: transmittance is 50% or more and less than 65%
×: transmittance is less than 50%
[0118]
Regarding the color space measurement of the transmitted light, the obtained image was used as a transmission image by an overhead projector (OHP: 9550 manufactured by 3M), and the image projected on the white wall surface was measured by a spectral radiance meter (PR650 manufactured by Photo Research). Was measured.
[0119]
And the hue angle h of the image projected on the white wall surface^*(OHP) and the hue angle h of the solid portion on the previous paper^*(Paper) angle difference Δh^*Was defined as shown below and indicated by a five-point scale.
[0120]
(Equation 2)
Δh^*> 30 = ×
20 <Δh^*≦ 30 = △ ×
10 <Δh^*≦ 20 = △
5 <Δh^*≦ 10 = ○ △
Δh^*≤ 5 = ○ (Δh^*: Chromaticity difference)
Was evaluated.
[0121]
【Example】
Hereinafter, the present invention will be specifically described based on examples. The parts in the following formulations are parts by weight unless otherwise specified.
[0122]
<Example 1>
0.1 M Na₃PO₄Aqueous solution and 1M CaCl₂Prepare an aqueous solution. In a 2-liter four-necked flask equipped with a high-speed stirrer TK homomixer, 710 parts of ion-exchanged water and 0.1 M₃PO₄550 parts of an aqueous solution was added, the number of revolutions was adjusted to 10,000 rpm, and the mixture was heated to 65 ° C. Here, 1M CaCl₂68 parts of an aqueous solution is gradually added, and a minute poorly water-soluble dispersant Ca is added.₃(PO₄)₂Was prepared.
[0123]
On the other hand, the dispersoid system
Styrene monomer 160 parts
40 parts of n-butyl acrylate monomer
Coloring agent [compound (I);Number average diameter0.06 μm] 5 parts
10 parts of saturated polyester
(Terephthalic acid-propylene oxide modified bisphenol A
(Acid value 8, peak molecular weight; 7000)
Aluminum salicylate compound 3 parts
Ester wax [Compound (4); maximum peak value 64.4 ° C] 20 parts
After the above mixture was dispersed for 3 hours using an attritor, 2 parts of 2,2′-azobis (2,4′-dimethylvaleronitrile) as a polymerization initiator was added, and the dispersion was charged into a dispersion medium. Granulation was performed for 8 minutes while maintaining the rotation speed. Thereafter, the stirring was changed from a high-speed stirring machine to a propeller stirring blade, and while stirring at 50 rotations, the internal temperature was raised to 60 ° C. for 4 hours, then the temperature was raised to 80 ° C., and polymerization was continued for 4 hours for a total of 8 hours. After the polymerization was completed, the slurry was cooled, and diluted hydrochloric acid was added to remove the dispersant.
[0124]
By further washing and drying, the weight average diameter of the yellow toner measured by a Coulter counter was 6.6 μm, and the number variation coefficient was 24%.
[0125]
Hydrophobized titanium oxide was externally added to the obtained toner by 2% to obtain a toner having excellent fluidity, and 7 parts of this toner was mixed with 93 parts of an acrylic resin-coated ferrite carrier to prepare a developer. A glossy 15 image and a transparency image were obtained with a modified full-color copying machine CLC500, and the evaluation was performed.
[0126]
As a result, there was almost no change in the hue angle between the image on paper and the transparency transmission image, and the OHP transparency was excellent.
[0127]
In addition, C.I. I. Pig. B15: A cyan toner was produced in the same manner except that the amount was changed to 36 parts, and the reproducibility of the secondary color green was also confirmed together with the yellow toner. As a result, a clear green image was obtained.
[0128]
<Comparative Example 1>
In the formulation of Example 1, the coloring agent was changed from compound (I) to C.I. I. Pig. A yellow toner was produced in the same manner as in Example 1 except that Y83 was changed to 7 parts.
[0129]
<Example 2>
A yellow toner was produced in the same manner as in Example 1 except that the amount of the aluminum salicylate compound was changed from 3 parts to 0.2 part in the formulation of Example 1.
[0130]
<Example 3>
For 100 parts of a polyester resin (Mn = 2500, Mw = 21000, Tg = 59 ° C., acid value = 9) obtained by condensing propoxylated bisphenol with fumaric acid and trimellitic acid,
Compound (I) 5 parts
Aluminum salicylate 2 parts
Ester wax (maximum peak value 69.4 ° C) 2 parts
Was added, and the mixture was melted, kneaded, crushed and classified to obtain yellow particles. The weight average diameter of the yellow particles was 6.7 μm, and the number variation coefficient was 38%.
[0131]
<Reference example>
A yellow toner was manufactured in the same manner as in Example 1 except that the coloring agent was changed to the compound (I) in which the colorant was expanded to 0.60 μm in the formulation of Example 1.
[0132]
<Example4>
A yellow toner was manufactured in the same manner as in Example 1 except that the aluminum salicylate compound was changed to the zinc salicylate compound in the formulation of Example 1.
[0133]
The characteristics of each toner and the evaluation thereof are shown below.
[0134]
[Table 1]

[0135]
【The invention's effect】
According to the present invention, a clear color can be obtained on an image having a low gloss level, and an image having a well-balanced hue and excellent transparency transparency can be obtained.

Claims (5)

At least a yellow colorant represented by the following structural formula, by polymerizing a polymerizable monomer system containing a metal salicylate compound and a polymerizable monomer, obtained by directly producing toner particles,
The yellow colorant before being contained in the polymerizable monomer system shows a particle size distribution in which the number average diameter is 0.01 to 0.50 μm in the alcoholic organic solvent, and the number average diameter of the colorant in the toner particles Is 0.01 to 0.70 μm,
Yellow toner and having a toner particle containing at least a binder resin, the yellow colorant and salicylic acid metal compound.

2. The yellow toner according to claim 1, wherein the salicylic acid metal compound is contained in an amount of 10 to 400 parts by weight based on 100 parts by weight of the yellow colorant. 3. The yellow toner according to claim 1, wherein the metal salicylate compound is an aluminum compound. The toner contains a low softening point substance , the low softening point substance is an ester wax having at least one long-chain ester moiety having 15 or more carbon atoms , and a main endothermic peak value of 40 to 90. The yellow toner according to any one of claims 1 to 3 , wherein the temperature is ° C. At least a yellow colorant represented by the following structural formula, a method for producing a yellow toner by directly polymerizing a polymerizable monomer system containing a salicylic acid metal compound and a polymerizable monomer to obtain toner particles,
A colorant having a number average particle size distribution of 0.01 to 0.50 μm in an alcoholic organic solvent is polymerized after being contained in a polymerizable monomer , and the yellow color in the toner particles is polymerized. A method for producing a yellow toner, comprising: obtaining toner particles having a number average particle diameter of 0.01 to 0.70 μm and containing at least a binder resin, the yellow colorant, and a metal salicylate compound .