JP3588744B2 - Electrostatic image developing toner and image forming method using the same - Google Patents

Description

【００８４】
［トナー合成例１］
低分子ラテックス表面カルボキシル基量Ａ＝２．１１×１０^−４、高分子ラテックス表面カルボキシル基量Ｂ＝２．１６×１０^−４のラテックスの組み合わせのトナー製造例。
【００８５】
低分子量成分ラテックス２を４００ｇ、高分子量成分ラテックス１を１００ｇ、顔料分散液１を６５ｇとイオン交換水３４０ｍｌを５Ｎ水酸化ナトリウム水溶液を用いてｐＨ＝９．５に調整した後、撹拌装置、冷却管、温度センサーを装着した２ｌの４頭フラスコに入れ、２５０ｒｐｍで撹拌を行った。ここに、塩化ナトリウム５９．４ｇを２６０ｍｌの蒸留水に溶解した電解質水溶液を添加し、更にイソプロピルアルコール８８ｍｌ、トリトンＸ−１００を９．０ｇを蒸留水７０ｍｌに溶解したノニオン界面活性剤水溶液を順次添加した後、内温を８５℃まで昇温し６時間反応を行った。
【００８６】
反応液を濾過後、蒸留水を加え再分散し、５Ｎの水酸化ナトリウム水溶液を用いｐＨ＝１３に調整し水洗、濾過を繰り返し、界面活性剤及び電解質を除去した後、乾燥を行った。乾燥後粒径をコールターカウンターを用い測定した。トナーの変動係数（ＣＶ）は標準偏差σを体積平均粒径ｄ_５０で割った値である。このトナーをトナー１とする。
【００８７】
［トナー合成例２］
低分子ラテックス表面カルボキシル基量Ａ＝１．０２×１０^−４、高分子ラテックス表面カルボキシル基量Ｂ＝１．１７×１０^−４のラテックスの組み合わせのトナー製造例。
【００８８】
低分子量成分ラテックス３を２６７ｇ、高分子量成分ラテックス２を１００ｇ、顔料分散液１を６５ｇとイオン交換水４７３ｍｌを５Ｎ水酸化ナトリウム水溶液を用いてｐＨ＝９．５に調整した後、撹拌装置、冷却管、温度センサーを装着した２ｌの４頭フラスコに入れ、２５０ｒｐｍで撹拌を行った。ここに、塩化ナトリウム４６．９ｇを２６０ｍｌの蒸留水に溶解した電解質水溶液を添加し、更にイソプロピルアルコール７７ｍｌ、トリトンＸ−１００を９．０ｇを蒸留水７０ｍｌに溶解したノニオン界面活性剤水溶液を順次添加した後、内温を８５℃まで昇温し６時間反応を行った。
【００８９】
反応液を濾過後、蒸留水を加え再分散し、５Ｎの水酸化ナトリウム水溶液を用いｐＨ＝１３に調整し水洗、濾過を繰り返し、界面活性剤及び電解質を除去した後、乾燥を行った。乾燥後粒径をコールターカウンターを用い測定した。このトナーをトナー２とする。
【００９０】
［トナー合成例３］
低分子ラテックス表面カルボキシル基量Ａ＝１．０２×１０^−４、高分子ラテックス表面カルボキシル基量Ｂ＝２．７８×１０^−４のラテックスの組み合わせのトナー製造例。
【００９１】
低分子量成分ラテックス３を２６７ｇ、高分子量成分ラテックス３を２００ｇ、顔料分散液１を６５ｇとイオン交換水３７３ｍｌを５Ｎ水酸化ナトリウム水溶液を用いてｐＨ＝９．５に調整した後、撹拌装置、冷却管、温度センサーを装着した２ｌの４頭フラスコに入れ、２５０ｒｐｍで撹拌を行った。ここに、塩化ナトリウム５３．２ｇを２６０ｍｌの蒸留水に溶解した電解質水溶液を添加し、更にイソプロピルアルコール８８ｍｌ、トリトンＸ−１００を９．０ｇを蒸留水７０ｍｌに溶解したノニオン界面活性剤水溶液を順次添加した後、内温を８５℃まで昇温し６時間反応を行った。
【００９２】
反応液を濾過後、蒸留水を加え再分散し、５Ｎの水酸化ナトリウム水溶液を用いｐＨ＝１３に調整し水洗、濾過を繰り返し、界面活性剤及び電解質を除去した後、乾燥を行った。乾燥後粒径をコールターカウンターを用い測定した。このトナーをトナー３とする。
【００９３】
［トナー合成例４］
低分子ラテックス表面カルボキシル基量Ａ＝２．１１×１０^−４、高分子ラテックス表面カルボキシル基量Ｂ＝２．１６×１０^−４のラテックスの組み合わせのトナー製造例。
【００９４】
低分子量成分ラテックス２を２６７ｇ、高分子量成分ラテックス１を１００ｇ、顔料分散液２を６５ｇとイオン交換水４７３ｍｌを５Ｎ水酸化ナトリウム水溶液を用いてｐＨ＝９．５に調整した後、撹拌装置、冷却管、温度センサーを装着した２ｌの４頭フラスコに入れ、２５０ｒｐｍで撹拌を行った。ここに、塩化ナトリウム６２．５ｇを２６０ｍｌの蒸留水に溶解した電解質水溶液を添加し、更にイソプロピルアルコール８０ｍｌ、トリトンＸ−１００を９．０ｇを蒸留水７０ｍｌに溶解したノニオン界面活性剤水溶液を順次添加した後、内温を８５℃まで昇温し６時間反応を行った。
【００９５】
反応液を濾過後、蒸留水を加え再分散し、５Ｎの水酸化ナトリウム水溶液を用いｐＨ＝１３に調整し水洗、濾過を繰り返し、界面活性剤及び電解質を除去した後、乾燥を行った。乾燥後粒径をコールターカウンターを用い測定した。このトナーをトナー４とする。
【００９６】
［トナー合成例５］
低分子ラテックス表面カルボキシル基量Ａ＝２．１１×１０^−４、高分子ラテックス表面カルボキシル基量Ｂ＝２．１６×１０^−４のラテックスの組み合わせのトナー製造例。
【００９７】
低分子量成分ラテックス２を２６７ｇ、高分子量成分ラテックス１を１００ｇ、顔料分散液３を６５ｇとイオン交換水４７３ｍｌを５Ｎ水酸化ナトリウム水溶液を用いてｐＨ＝９．５に調整した後、撹拌装置、冷却管、温度センサーを装着した２ｌの４頭フラスコに入れ、２５０ｒｐｍで撹拌を行った。ここに、塩化ナトリウム４３．８ｇを２６０ｍｌの蒸留水に溶解した電解質水溶液を添加し、更にイソプロピルアルコール７７ｍｌ、トリトンＸ−１００を９．０ｇを蒸留水７０ｍｌに溶解したノニオン界面活性剤水溶液を順次添加した後、内温を８５℃まで昇温し６時間反応を行った。
【００９８】
反応液を濾過後、蒸留水を加え再分散し、５Ｎの水酸化ナトリウム水溶液を用いｐＨ＝１３に調整し水洗、濾過を繰り返し、界面活性剤及び電解質を除去した後、乾燥を行った。乾燥後粒径をコールターカウンターを用い測定した。このトナーをトナー５とする。
【００９９】
［トナー合成例６］
低分子ラテックス表面カルボキシル基量Ａ＝２．１１×１０^−４、高分子ラテックス表面カルボキシル基量Ｂ＝２．１６×１０^−４のラテックスの組み合わせのトナー製造例。
【０１００】
低分子量成分ラテックス２を２６７ｇ、高分子量成分ラテックス１を１００ｇ、顔料分散液４を６５ｇとイオン交換水４７３ｍｌを５Ｎ水酸化ナトリウム水溶液を用いてｐＨ＝９．５に調整した後、撹拌装置、冷却管、温度センサーを装着した２ｌの４頭フラスコに入れ、２５０ｒｐｍで撹拌を行った。ここに、塩化ナトリウム４６．９ｇを２６０ｍｌの蒸留水に溶解した電解質水溶液を添加し、更にイソプロピルアルコール８０ｍｌ、トリトンＸ−１００を９．０ｇを蒸留水７０ｍｌに溶解したノニオン界面活性剤水溶液を順次添加した後、内温を８５℃まで昇温し６時間反応を行った。
【０１０１】
反応液を濾過後、蒸留水を加え再分散し、５Ｎの水酸化ナトリウム水溶液を用いｐＨ＝１３に調整し水洗、濾過を繰り返し、界面活性剤及び電解質を除去した後、乾燥を行った。乾燥後粒径をコールターカウンターを用い測定した。このトナーをトナー６とする。
【０１０２】
［比較トナー合成例１］
低分子ラテックス表面カルボキシル基量Ａ＝０．２６×１０^−４、高分子ラテックス表面カルボキシル基量Ｂ＝２．７８×１０^−４のラテックスの組み合わせのトナー製造例。
【０１０３】
低分子量成分ラテックス５を２６７ｇ、高分子量成分ラテックス３を２００ｇ、顔料分散液１を６５ｇとイオン交換水３７３ｍｌを５Ｎ水酸化ナトリウム水溶液を用いてｐＨ＝９．５に調整した後、撹拌装置、冷却管、温度センサーを装着した２ｌの４頭フラスコに入れ、２５０ｒｐｍで撹拌を行った。ここに、塩化ナトリウム４３．８ｇを２６０ｍｌの蒸留水に溶解した電解質水溶液を添加し、更にイソプロピルアルコール７７ｍｌ、トリトンＸ−１００を９．０ｇを蒸留水７０ｍｌに溶解したノニオン界面活性剤水溶液を順次添加した後、内温を８５℃まで昇温し６時間反応を行った。
【０１０４】
反応液を濾過後、蒸留水を加え再分散し、５Ｎの水酸化ナトリウム水溶液を用いｐＨ＝１３に調整し水洗、濾過を繰り返し、界面活性剤及び電解質を除去した後、乾燥を行った。乾燥後粒径をコールターカウンターを用い測定した。このトナーを比較トナー１とする。
【０１０５】
［比較トナー合成例２］
低分子ラテックス表面カルボキシル基量Ａ＝２．１１×１０^−４、高分子ラテックス表面カルボキシル基量Ｂ＝０．３７×１０^−４のラテックスの組み合わせのトナー製造例。
【０１０６】
低分子量成分ラテックス２を４００ｇ、高分子量成分ラテックス４を１００ｇ、顔料分散液１を６５ｇとイオン交換水３４０ｍｌを５Ｎ水酸化ナトリウム水溶液を用いてｐＨ＝９．５に調整した後、撹拌装置、冷却管、温度センサーを装着した２ｌの４頭フラスコに入れ、２５０ｒｐｍで撹拌を行った。ここに、塩化ナトリウム４２．５ｇを２６０ｍｌの蒸留水に溶解した電解質水溶液を添加し、更にイソプロピルアルコール７７ｍｌ、トリトンＸ−１００を９．０ｇを蒸留水７０ｍｌに溶解したノニオン界面活性剤水溶液を順次添加した後、内温を８５℃まで昇温し６時間反応を行った。
【０１０７】
反応液を濾過後、蒸留水を加え再分散し、５Ｎの水酸化ナトリウム水溶液を用いｐＨ＝１３に調整し水洗、濾過を繰り返し、界面活性剤及び電解質を除去した後、乾燥を行った。乾燥後粒径をコールターカウンターを用い測定した。トナーの変動係数（ＣＶ）は標準偏差σを体積平均粒径ｄ_５０で割った値である。このトナーを比較トナー２とする。
【０１０８】
［比較トナー合成例３］
低分子ラテックス表面カルボキシル基量Ａ＝１．８４×１０^−４、高分子ラテックス表面カルボキシル基量Ｂ＝０．３７×１０^−４のラテックスの組み合わせのトナー製造例。
【０１０９】
低分子量成分ラテックス１を４００ｇ、高分子量成分ラテックス４を１００ｇ、顔料分散液１を６５ｇとイオン交換水３４０ｍｌを５Ｎ水酸化ナトリウム水溶液を用いてｐＨ＝９．５に調整した後、撹拌装置、冷却管、温度センサーを装着した２ｌの４頭フラスコに入れ、２５０ｒｐｍで撹拌を行った。ここに、塩化ナトリウム３８．８ｇを２６０ｍｌの蒸留水に溶解した電解質水溶液を添加し、更にイソプロピルアルコール７７ｍｌ、トリトンＸ−１００を９．０ｇを蒸留水７０ｍｌに溶解したノニオン界面活性剤水溶液を順次添加した後、内温を８５℃まで昇温し６時間反応を行った。
【０１１０】
反応液を濾過後、蒸留水を加え再分散し、５Ｎの水酸化ナトリウム水溶液を用いｐＨ＝１３に調整し水洗、濾過を繰り返し、界面活性剤及び電解質を除去した後、乾燥を行った。乾燥後粒径をコールターカウンターを用い測定した。このトナーを比較トナー３とする。
【０１１１】
［比較トナー合成例４］
低分子ラテックス表面カルボキシル基量Ａ＝０．２６×１０^−４、高分子ラテックス表面カルボキシル基量Ｂ＝０．３７×１０^−４のラテックスの組み合わせのトナー製造例。
【０１１２】
高分子量成分ラテックス５を２６７ｇ、低分子量成分ラテックス４を１００ｇ、顔料分散液１を６５ｇとイオン交換水４７３ｍｌを５Ｎ水酸化ナトリウム水溶液を用いてｐＨ＝９．５に調整した後、撹拌装置、冷却管、温度センサーを装着した１ｌの４頭フラスコに入れ、２５０ｒｐｍで撹拌を行った。ここに、塩化ナトリウム２５．０ｇを２６０ｍｌの蒸留水に溶解した電解質水溶液を添加し、更にイソプロピルアルコール５７ｍｌ、トリトンＸ−１００ ９．０ｇを蒸留水７０ｍｌに溶解したノニオン界面活性剤水溶液を順次添加した後、内温を８５℃まで昇温し６時間反応を行った。
【０１１３】
反応液を濾過後、蒸留水を加え再分散し、５Ｎの水酸化ナトリウム水溶液を用いｐＨ＝１３に調整し水洗、濾過を繰り返し、界面活性剤及び電解質を除去した後、乾燥を行った。乾燥後粒径をコールターカウンターを用い測定した。このトナーを比較トナー４とする。
【０１１４】
［比較トナー合成例５］
低分子ラテックス表面カルボキシル基量Ａ＝４．２５×１０^−４、高分子ラテックス表面カルボキシル基量Ｂ＝４．３１×１０^−４のラテックスの組み合わせのトナー製造例。
【０１１５】
低分子量成分ラテックス４を６００ｇ、高分子量成分ラテックス５を１５０ｇ、顔料分散液１を２５ｇとイオン交換水９０ｍｌを５Ｎ水酸化ナトリウム水溶液を用いてｐＨ＝９．５に調整した後、撹拌装置、冷却管、温度センサーを装着した１ｌの４頭フラスコに入れ、２５０ｒｐｍで撹拌を行った。ここに、塩化ナトリウム７９．４ｇを２６０ｍｌの蒸留水に溶解した電解質水溶液を添加し、更にイソプロピルアルコール９３ｍｌ、トリトンＸ−１００ ９．０ｇを蒸留水７０ｍｌに溶解したノニオン界面活性剤水溶液を順次添加した後、内温を８５℃まで昇温し６時間反応を行った。
【０１１６】
反応液を濾過後、蒸留水を加え再分散し、５Ｎの水酸化ナトリウム水溶液を用いｐＨ＝１３に調整し水洗、濾過を繰り返し、界面活性剤及び電解質を除去した後、乾燥を行った。乾燥後粒径をコールターカウンターを用い測定した。このトナーを比較トナー５とする。
【０１１７】
【表２】

【０１１８】
評価１
本発明のトナー１〜６及び比較トナー１〜５を用い、これら１００重量部に対して疎水性シリカ２重量部、酸化チタン１重量部を添加混合し、この外添処理トナー５重量部とメタクリル酸メチル／スチレン共重合体（ＭＡＡ／Ｓｔ＝７／３重量比）で表面被覆したフェライト粒子（キャリア、平均粒径６０μｍ）９５重量部を混合し、本発明の現像剤１〜３及び比較現像剤１〜４とした。この現像剤を振とう機で６０分振とうした時の帯電量をブローオフ法を用いて測定した。測定は低温低湿（ＬＬ）、高温高湿（ＨＨ）で行い、ＬＬとＨＨの帯電量差を環境差とした。
【０１１９】
測定結果を表３に示した。
【０１２０】
【表３】

【０１２１】
この結果、低分子量成分ラテックスの表面カルボキシル基量が０．６×１０^−４以上、３．５×１０^−４以下、高分子量成分ラテックスの表面カルボキシル基量が０．８×１０^−４以上、４×１０^−４以下で｜Ａ−Ｂ｜が発明規定内のトナーの帯電量は、環境差が非常に少ない。
【０１２２】
評価２
定着ローラー温度を１８０℃へ固定したものを用い、上記現像剤を使用し、コニカ製カラー複写機９０２８を改造してロングランを実施した。条件は下記に示す条件である。感光体としては積層型有機感光体を使用した。
【０１２３】
感光体表面電位＝−５５０Ｖ
ＤＣバイアス＝−２５０Ｖ
ＡＣバイアス＝Ｖｐ−ｐ：−５０〜−４５０Ｖ
交番電界周波数＝１８００Ｈｚ
Ｄｓｄ＝３００μｍ
押圧規制力＝１０ｇｆ／ｍｍ
押圧規制棒＝ＳＵＳ４１６（磁性ステンレス製）／直径３ｍｍ
現像剤層厚＝１５０μｍ
現像スリーブ＝２０ｍｍ
環境条件は高温高湿（３３℃／８０％ＲＨ）にて実施し、５０００枚毎にべた黒画像をプリントしながら、連続で画素率が１％の画像を１０万枚の印字をし、画像汚れの発生の有無を比較した。
【０１２４】
画像汚れとは、トナーが現像器等に付着し、べた黒画像に白すじ等が発生する程度を評価した。
【０１２５】
測定結果を表４に示した。
【０１２６】
【表４】

【０１２７】
この結果から、本発明内のトナー１〜６に比して比較トナー１，２は、画像汚れが多いことが明白である。
【０１２８】
【発明の効果】
本発明により、トナーにおいて分子量の異なる樹脂粒子をトナー粒子中で局在化させて、トナー粒子の機械的強度を改善することが出来る。また、小粒径で粒度分布の狭いトナー粒子を提供することが出来る。
【図面の簡単な説明】
【図１】本発明に係わる画像形成方法を説明する概要断面図。
【符号の説明】
１ レーザー光源
４ 感光体ドラム
５ 帯電ユニット
６ 現像ユニット
７ 転写極
１１ クリーニング装置
１３ 弾性体ゴムブレード[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electrostatic image developing toner used in a copying machine, a printer, and the like, and an image forming method using the same.
[0002]
[Prior art]
Conventionally, a toner for developing an electrostatic image generally used is appropriately dry-mixed with a polymer obtained by various polymerization methods, a coloring agent such as carbon black, a charge controlling agent and / or a magnetic material. It is manufactured by melt-kneading, etc., followed by pulverization and classification.
[0003]
As another method, a method of directly manufacturing a toner by a suspension polymerization method or the like has been proposed. A method using particles produced by an emulsion polymerization method has also been proposed (JP-A-60-220358 and JP-A-4-284461).
[0004]
However, the toner obtained by the above-described melt-kneading and pulverizing method has a limitation in controlling the toner particle size, and it is difficult to produce a toner having a small particle size with high yield. In addition, there is a disadvantage that the components forming the toner are not uniformly dispersed and the charge amount distribution tends to be broad.
[0005]
Further, the direct production method by the suspension polymerization method has a disadvantage that not only is it difficult to reduce the particle size, but also the particle size distribution becomes wide. Furthermore, the toner produced by this method is basically spherical, and has a disadvantage that it is difficult to clean the residual toner during the image forming process.
[0006]
On the other hand, according to the methods disclosed in JP-A-60-220358 and JP-A-4-284461, it is possible to obtain non-spherical particles having irregularities on the surface instead of spherical toner as described above. It is difficult to control the particle size and particle size distribution, and it is necessary to perform classification after the reaction is completed to obtain the desired particle size and particle size distribution.
[0007]
Further, in the method disclosed in JP-A-4-284461, it is necessary to finely adjust the zeta potential of the colorant and the polymer particles. This not only makes it difficult to improve the productivity, but also makes it easy for the coloring agent and the like to be localized in the generated toner particles, and when resin particles having different molecular weights are used, they are uniformly mixed in the toner particles. It has the disadvantage that the resulting toner particles cannot have sufficient mechanical strength.
[0008]
[Problems to be solved by the invention]
It is an object of the present invention to improve the mechanical strength of toner particles by localizing resins having different molecular weights in the toner particles in the toner particles. Another object of the present invention is to provide toner particles having a small particle size and a narrow particle size distribution.
[0009]
[Means for Solving the Problems]
The object of the present invention is achieved by adopting the following configuration.
[0010]
(1) Heavy weight in molecular weight distribution measurement by GPCQuantityLow molecular weight component resin latex having a peak molecular weight between 1,000 and 50,000,QuantityIn a toner for developing an electrostatic image, which is produced by mixing a high molecular weight component resin latex having a peak between 80,000 and 700,000, a colorant and a fixing improver, and coagulating and fusing, When the amount of carboxyl groups present on the surface of the low molecular weight resin latex is A [mol / g] and the amount of carboxyl groups present on the surface of the high molecular weight resin latex is B [mol / g], the following formula (1) A) a toner for developing an electrostatic image.
[0011]
0.6 × 10^-Four≦ A ≦ 3.5 × 10^-Four
0.8 × 10^-Four≦ B ≦ 4 × 10^-Four
1 × 10^-6≦ | AB | ≦ 2 × 10^-Four                    Equation (1)
(2) Weight was measured by molecular weight distribution measurement using GPC.QuantityLow molecular weight component resin latex having a peak molecular weight between 1,000 and 50,000,QuantityIn a toner for developing an electrostatic image, which is produced by mixing a high molecular weight component resin latex having a peak between 80,000 and 700,000, a colorant and a fixing improver, and coagulating and fusing, When the amount of carboxyl groups present on the surface of the low molecular weight component resin latex is A [mol / g] and the amount of carboxyl groups present on the surface of the high molecular weight component resin latex is B [mol / g], the following formula (2) A) a toner for developing an electrostatic image.
[0012]
0.6 × 10^-4≦ A ≦ 3.5 × 10^-4
0.8 × 10^-4≦ B ≦ 4 × 10^-4
1 × 10^-6≦ BA ≦ 2 × 10^-4                        Equation (2)
(3) The toner for developing an electrostatic image according to (1) or (2), wherein the low molecular weight resin latex and the high molecular weight resin latex contain an ionic monomer unit having a carboxyl group.
[0013]
(4) In an image forming method for visualizing an electrostatic latent image formed on a photoreceptor to form a toner image, the toner is the electrostatic image developing toner according to (1) or (2). Image forming method.
[0014]
(5) An image forming method for transferring a toner image formed on a photoreceptor, wherein the toner is the toner for developing an electrostatic image according to (1) or (2).
[0015]
(6) In an image forming method for transferring a toner image formed on a photoreceptor onto a transfer material and then cleaning the toner remaining on the photoreceptor, the toner according to (1) or (2), An image forming method, being a toner for developing a charge image.
[0016]
The reason why the effects of the present invention can be obtained by the above configuration is considered as follows.
[0017]
By adjusting the amount of surface carboxyl groups of the low molecular weight resin latex (A) and the high molecular weight resin latex (B), the positions of A and B in the particles (toner particles) obtained by aggregating the latex particles can be controlled. . That is, when the amount of carboxyl groups on the surface of the latex is increased, the latex is hardly aggregated, so that the latex is easily collected on the surface of the toner particles. On the other hand, when the amount of carboxyl groups on the surface is small, it tends to be easily collected inside the toner particles. By changing the amount of surface carboxyl groups in this way, it is possible to localize in the toner particles.
[0018]
Utilizing the above properties, for example, when the surface carboxyl group content of the high molecular weight latex is larger than the surface carboxyl group content of the low molecular weight latex, the high molecular weight component is localized on the toner particle surface, so that the mechanical strength of the toner is improved. . On the other hand, when the difference in the amount of carboxyl groups on the surface between latexes A and B increases, the difference in cohesiveness also increases, causing the particle size distribution of the toner particles to widen. It is presumed that the best balance among these is the configuration of the present invention described above.
[0019]
In the present invention, the peak of the molecular weight refers to the peak of the voltage detected by the detector when the molecular weight distribution is measured by GPC. The monomer unit is obtained by polymerizing the latex of the present invention in a monomer unit, and indicates the monomer unit.
[0020]
(Amount of carboxyl group on latex surface)
The carboxyl group content on the surface of the low molecular weight resin latex is 0.6 × 10^-4mol / g, the amount of carboxyl groups on the surface of the high molecular weight component resin latex is 0.8 × 10^-4If it is less than mol / g, the particle size distribution is narrow, and it becomes difficult to produce a toner having a small particle size. Further, the toner cannot have mechanical strength. Further, the amount of each surface carboxyl group is 3.5 × 10^-4mol / g or 4 × 10^-4If it exceeds mol / g, the hydrophilicity of the toner particles becomes strong and the charge amount becomes unstable.
[0021]
The absolute value of the difference between the surface carboxyl groups of the low molecular weight component resin latex and the high molecular weight component resin latex is 1 × 10^-6≦ | AB | ≦ 2 × 10^-4The toner particles having a narrow particle size distribution can be generated by adjusting the particle size to the range described above.
[0022]
Further, the low molecular weight component resin latex was used to reduce the surface carboxyl group content of the high molecular weight resin latex to 1 × 10^-6≦ BA ≦ 2 × 10^-4By adjusting the ratio to the range described above, the high molecular weight component is localized on the surface of the toner particles, so that the toner can have mechanical strength.
[0023]
(Method of adjusting the amount of carboxyl groups on the surface of latex)
The amount of the carboxyl group on the latex surface can be adjusted by changing the ratio of the monomer having a carboxyl group in the monomer added at the time of polymerization. It is also possible to change the amount of monomer and the amount of water added during polymerization.
[0024]
The ratio of the monomer having a carboxyl group in the monomer is preferably 1 to 12 parts by weight, more preferably 2 to 10 parts by weight.
[0025]
The amount of monomer added / the amount of water added can be arbitrarily changed, but if the amount of monomer added is larger than the amount of water added, polymerization does not proceed. The preferred range is 40/60 to 3/97 in weight ratio, and the more preferred range is preferably changed in the range of 35/65 to 5/95.
[0026]
(Measurement of carboxyl group content on latex surface)
The amount of carboxyl groups on the surface of the latex particles can be measured by titration. In the titration method, a strong base solution, for example, an aqueous sodium hydroxide solution is used as a titration reagent, and electrical properties, for example, conductivity, pH, etc., are measured, and the titration is determined from a titration curve. The amount of carboxyl groups on the surface of latex particles is expressed as a value obtained by dividing the amount of carboxyl groups determined by titration by the weight of latex particles, that is, the amount of carboxyl groups per unit latex weight.
[0027]
(Monomer having a carboxyl group)
Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, tetrahydroterephthalic acid, α-alkyl-substituted acrylic acid (substituted alkyl has 1 to 4 carbon atoms), monoalkylitacon Examples thereof include an acid (substituted alkyl has 1 to 4 carbon atoms) and monoalkylmaleic acid (substituted alkyl has 1 to 4 carbon atoms).
[0028]
(Resin latex)
The resin latex can be generally prepared by an emulsion polymerization method, a suspension polymerization method, a dispersion polymerization method, a precipitation polymerization method, an interfacial polymerization method, a pulverized fine powder of a synthetic resin, or the like. Resin latex is used.
[0029]
In order to compound the solid component according to the present invention (a component other than the binder resin necessary for the toner for developing an electrostatic image) with a resin latex, the solid component according to the present invention must be dispersed in a desired monomer. Alternatively, if the solid component can be dissolved, it can be synthesized by dissolving in a monomer, then dispersing in a dispersion, and polymerizing.
[0030]
Particularly preferably, the resin latex according to the present invention disperses the solid component according to the present invention in the presence of a surfactant having a concentration equal to or higher than the critical micelle formation concentration (CMC), It is obtained by diluting the agent so as to have a CMC or less, adding a radical polymerizable monomer and a radical polymerization initiator, and performing polymerization at a predetermined temperature.
[0031]
Any particle size of these resin latexes can be used as long as it is equal to or less than the target non-spherical particle size, but the particle size of the resin latex generally used is 0.01 to 10 μm. Are preferred.
[0032]
(Monomer)
In order to obtain the resin latex of the present invention, a hydrophobic monomer is used.
[0033]
Examples of the hydrophobic monomer of the present invention include styrene derivatives such as styrene, p-methylstyrene, o-methylstyrene, p-chlorostyrene, o-chlorostyrene, p-methoxystyrene, o-methoxystyrene and p-methylstyrene. -Ethoxystyrene, p-butoxystyrene, 2,4-dimethylstyrene, 2,4-dichlorostyrene, p-chloromethylstyrene, o-chloromethylstyrene, p-hydroxystyrene, o-hydroxystyrene and the like. In addition, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, dodecyl (meth) acrylate and the like ( Also included are (meth) acrylates. Further, nitrile monomers such as acrylonitrile and methacrylonitrile, vinyl ether monomers such as vinyl methyl ether and vinyl ethyl ether, vinyl ester monomers such as vinyl acetate and vinyl butyrate, and olefins such as ethylene, propylene and isobutylene. Conjugated dienes such as system monomers, butadiene, isoprene, chloroprene, and dimethylbutadiene. These may be used alone or in combination of two or more as necessary.
[0034]
These various monomers are selected according to the purpose, for example, according to a desired glass transition temperature, melting temperature and the like.
[0035]
(Radical polymerization initiator)
When synthesizing the resin latex of the present invention, a radical polymerization initiator is selected according to the polymerization method. That is, in the case of the suspension polymerization method, an oil-soluble radical polymerization initiator is used, and in the case of the emulsion polymerization method, a water-soluble radical polymerization initiator is used. Furthermore, in the case of dispersion polymerization, it is appropriately selected depending on the dispersion medium used, but when using a non-aqueous solvent and when using a mixed solvent of water-miscible organic solvent and water, it is possible to use a water-soluble radical polymerization initiator. It is possible.
[0036]
Examples of water-soluble radical polymerization initiators include persulfates, such as potassium persulfate and ammonium persulfate, and water-soluble azo compounds, such as azobisaminodipropane acetate, azobiscyanovaleric acid and salts thereof, and the like, For example, hydrogen peroxide and the like can be mentioned.
[0037]
Examples of the oil-soluble radical polymerization initiator include oil-soluble peroxides such as benzoyl peroxide and lauroyl peroxide. Examples of the oil-soluble azo polymerization initiator include azobisisobutyronitrile, azobisvaleronitrile and the like. The addition amount of these can be determined according to the molecular weight of the target resin latex and the like. Further, if necessary, a molecular weight regulator, for example, a chain transfer agent represented by a thiol compound, for example, dodecanethiol, octylthiol and the like can be used.
[0038]
The resin latex according to the present invention may have a Tg in the range of -10 to 120C, more preferably 0 to 90C. The softening point is in the range of 80 to 220 ° C. The monomer composition of the resin latex satisfies this range, and it is sufficient that the resin latex contains a polymer unit having a dissociable group in an amount of 0.1 to 20% by weight based on the weight of the polymer. The type and composition of the polymerization monomer are not limited.
[0039]
The molecular weight distribution of the resin latex according to the present invention is 1.5 to 100, preferably 1.8 to 50 in terms of the ratio of the weight average molecular weight to the number average molecular weight (abbreviated as Mw / Mn).
[0040]
(Solid component)
The resin latex according to the present invention can be combined with a solid component as described above. Commonly used solid components include pigments and dyes as colorants. Other examples include a fixing property improving agent (release agent) and a charge control agent. These can be used alone or in combination.
[0041]
Examples of the pigment include an inorganic pigment and an organic pigment. Inorganic pigments include carbon pigments such as carbon black, grafted carbon, furnace black, and thermatomic carbon, magnetite, ferrite, red iron oxide, titanium oxide, zinc oxide, silica, chromium oxide, cobalt blue, ultramarine, cerulean blue, and mineral. Metal oxide pigments such as violet and trilead tetroxide; metal powder pigments such as zinc powder, iron powder, and copper powder; sulfide pigments such as zinc sulfide, cadmium red, mercury sulfide, selenium red, and cadmium yellow; Examples thereof include chromate pigments such as molybdenum red, barium yellow, stylonium yellow, and chromium yellow, and ferrocyanide pigments such as milori blue.
[0042]
In particular, carbon black, furnace black and the like are preferable as the inorganic pigment.
[0043]
Examples of the organic pigment include compounds described in Color Index and the like. For example, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.
[0044]
C. as magenta or red pigments; I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 7, C.I. I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 53: 1, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 139, C.I. I. Pigment Red 144, C.I. I. Pigment Red 149, C.I. I. Pigment Red 166, C.I. I. Pigment Red 178, C.I. I. Pigment Red 222 and the like.
[0045]
Yellow or orange pigments include C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I. Pigment yellow 138, C.I. I. Pigment Yellow 180 and the like.
[0046]
Generally, C.I. I. Pigment Blue 15: 3 is known as copper-phthalocyanine, and magenta organic pigments such as C.I. I. Dimethylquinacridone known as CI Pigment Red 122 is C.I. I. Disazo yellow known as CI Pigment Yellow 17 is used.
[0047]
Further, for example, low-molecular-weight polyethylene, low-molecular-weight polypropylene, oxidized polyethylene, oxidized polypropylene, acid-modified polyethylene, acid-modified polypropylene, polyolefin-based wax (for example, Hitec manufactured by Toho Chemical Industry Co., Ltd.) ) Can be used.
[0048]
Use a positive charge control agent such as a nigrosine dye, a quaternary ammonium salt, or an alkylamide, or a negative charge control agent such as an azo metal complex, chlorinated paraffin, chlorinated polyester, or sulfonylamine of copper phthalocyanine. Can be done.
[0049]
These can each be contained in the polymer in an amount of 0.1 to 25% by weight.
[0050]
(Aggregation / fusion)
Aggregation and fusion are performed using the resin latex generated in the polymerization step to produce a toner. Various methods for fusing and associating include, for example, JP-A-60-220358 and JP-A-4-284664. However, it is quite difficult to control the desired particle size and particle size distribution. Therefore, the present inventors have produced a toner by using the method described in JP-A-5-115572, that is, a method in which a coagulant having a critical coagulation concentration of a resin latex or more and an organic solvent infinitely soluble in water are added.
[0051]
Next, although not limited thereto, FIG. 1 shows an example of a digital copying machine, and an image forming method according to the present invention will be described.
[0052]
As described above, the image forming process according to the present invention is particularly effective in an image forming method including reversal development such as a printer and a digital copying machine.
[0053]
In the image forming apparatus of FIG. 1, although not shown in the figure, light from a light source is applied to a document, reflected light is converted into an electric signal by an image reading unit, and this image data is transmitted to the image writing units 1 to 3. (1 is a laser light source, 2 is a polygon mirror, and 3 is an fθ lens).
[0054]
On the other hand, the photoreceptor drum 4 responsible for image formation is uniformly charged by corona discharge in the charging unit 5, and subsequently, image exposure light is irradiated onto the photoreceptor drum 4 from the laser light source 1 in the image writing unit. Then, the image is reverse-developed by the next developing unit 6 and transferred to a recording paper (transfer material) 8 by a transfer pole 7. The recording paper 8 is separated from the photosensitive drum by the separation pole 9 and is fixed by the fixing device 10. On the other hand, the photosensitive drum 4 is cleaned by the cleaning device 11. Reference numeral 12 denotes a pre-charging exposure lamp, which may be provided after the separation pole 9 and before the cleaning device 11.
[0055]
After transferring the toner image to the transfer material, the toner remaining on the photoconductor is removed by cleaning, and the photoconductor is repeatedly used in the next image forming process.
[0056]
The cleaning mechanism is preferably a blade cleaning method using a so-called elastic rubber blade. Reference numeral 13 denotes an elastic rubber blade.
[0057]
As a material constituting the elastic rubber blade 13, an elastic material such as silicone rubber or urethane rubber can be used.
[0058]
In the above, the process using a single color has been described. However, in some cases, an image in a plurality of colors such as two colors may be used. The process of charging, laser light exposure, and developing the corresponding color toner is repeated for the signals for each separated color that has been color-separated at the time of image reading, and the four color toners of yellow, magenta, cyan, and black toners are repeated. An image may be formed on a photoreceptor and transferred collectively to recording paper.
[0059]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples, but embodiments of the present invention are not limited thereto.
[0060]
[Production of emulsified dispersion of fixability improver]
According to a conventional method, 120 g of low molecular weight polypropylene (number average molecular weight = 3300, molecular weight distribution (Mw / Mn) = 4.5) was modified with 5.7 g of maleic anhydride, and the melt viscosity was measured. The improver was added to 280 g of an aqueous solution of nonylphenoxyethanol (mol number of added ethoxy units = 20, HLB = 16.0) in which hydrochloric acid was dissolved, the pH was adjusted to 9 with potassium hydroxide, and the pressure was increased to increase the temperature. Emulsified and dispersed above the softening point of polypropylene. The modified polypropylene dispersed particle diameter was measured by a light scattering electric permanent particle diameter measuring apparatus (ELS-800: manufactured by Otsuka Electronics Co., Ltd.), and as a result, was 182 nm. This emulsified dispersion of fixability improver is referred to as emulsified dispersion of fixer.
[0061]
[Production of pigment dispersion 1]
36.78 g of sodium dodecyl sulfate was added to 530 ml of ion-exchanged water, and 80.0 g of carbon black (Regal 330R, manufactured by Cabot) was dispersed using an ultrasonic homogenizer and a pressure type disperser. The average particle size of the carbon black in the dispersion was measured by a light scattering electric permanent particle size analyzer (ELS-800: manufactured by Otsuka Electronics Co., Ltd.), and as a result, was 95 nm.
[0062]
[Production of pigment dispersions 2, 3, 4]
Instead of carbon black in the production example of Pigment Dispersion Liquid 1, C.I. I. Pigment Yellow 17, C.I. I. Pigment Red 122, C.I. I. Pigment Blue 15: 3, except that Pigment Blue 15: 3 was used. The average particle size of the pigment in the dispersion was measured with a light scattering electric permanent particle size analyzer (ELS-800: manufactured by Otsuka Electronics Co., Ltd.), and the results were 148 nm, 133 nm, and 105 nm, respectively.
[0063]
[High molecular weight componentresinExample of synthesis of latex 1]
1080 ml of distilled water was added to a 2-liter four-necked flask equipped with a cooling tube, a thermometer, a stirrer, and a nitrogen inlet tube, and 246.4 g of styrene, 48 g of n-butyl acrylate, 25.6 g of methacrylic acid, and tert- 0.30 g of dodecyl mercaptan and further 64 g of the emulsifying dispersion of the fixing improver were added, and the mixture was stirred at a stirring speed of 250 rpm and heated to 70 ° C. while flowing nitrogen while flowing nitrogen. While maintaining the internal temperature at 70 ° C., an aqueous solution of a polymerization initiator obtained by dissolving 3.28 g of potassium persulfate in 200 ml of pure water was added. Was done. After the polymerization was completed, the internal temperature was lowered to room temperature, a part was taken out, and the molecular weight was measured using gel permeation chromatography (hereinafter abbreviated as GPC).
In addition, the high molecular weight component latex may be abbreviated to the high molecular weight component latex within a range that does not cause misunderstanding.
[0064]
The surface carboxyl group content of the high molecular weight component latex was measured by conductivity titration.
[0065]
Conductivity titration is performed by diluting the above latex to a solid concentration of 5% by weight, adding a 0.05 N aqueous solution of sodium hydroxide dropwise at an interval of 15 seconds in 0.5 ml portions, and using the conductivity and the amount of the aqueous sodium hydroxide solution added. Create a titration curve. The inflection point was determined from the titration curve to determine the amount of carboxyl groups on the surface of the latex.
[0066]
[Synthesis example of high molecular weight component latex 2]
A high-molecular-weight component latex 1 was prepared in the same manner as in Synthesis Example 1 except that the amount of added monomer was changed to 259.2 g of styrene, 48 g of n-butyl acrylate, and 12.8 g of methacrylic acid.
[0067]
[Synthesis example of high molecular weight component latex 3]
1240 ml of distilled water was added to a 2 liter four-necked flask equipped with a cooling tube, a thermometer, a stirrer, and a nitrogen inlet tube, and 123.2 g of styrene, 24 g of n-butyl acrylate, 12.8 g of methacrylic acid, tert- 0.15 g of dodecyl mercaptan and further 32 g of an emulsifying dispersion of a fixing improver were added, and the mixture was stirred at a stirring speed of 350 rpm and heated to 70 ° C. while flowing nitrogen while flowing nitrogen. While maintaining the internal temperature at 70 ° C., an aqueous solution of a polymerization initiator in which 1.64 g of potassium persulfate was dissolved in 100 ml of pure water was added, and polymerization was performed for 6 hours while maintaining the internal temperature at 70 ° C. and the stirring speed at 250 rpm under a nitrogen stream. Was done.
[0068]
The molecular weight and the amount of carboxyl groups on the latex surface were measured in the same manner as in the synthesis example of the high molecular weight component latex 1.
[0069]
[Synthesis example of high molecular weight component latex 4]
1080 ml of distilled water was added to a 2 l four-necked flask equipped with a cooling tube, a thermometer, a stirrer, and a nitrogen inlet tube, and 270.4 g of styrene, 48 g of n-butyl acrylate, 1.6 g of methacrylic acid, tert- 0.30 g of dodecyl mercaptan and further 64 g of the emulsifying dispersion of the fixing improver were added, and the mixture was stirred at a stirring speed of 350 rpm and heated to 70 ° C. while flowing nitrogen while flowing nitrogen. While maintaining the internal temperature at 70 ° C., an aqueous solution of a polymerization initiator obtained by dissolving 3.23 g of potassium persulfate in 100 ml of pure water was added. Was done.
[0070]
The molecular weight and the amount of carboxyl groups on the latex surface were measured in the same manner as in the synthesis example of the high molecular weight component latex 1.
[0071]
[Synthesis example of high molecular weight component latex 5]
1320 ml of distilled water was added to a 2 l four-necked flask equipped with a cooling tube, a thermometer, a stirrer, and a nitrogen inlet tube, and 63.2 g of styrene, 12 g of n-butyl acrylate, 4.8 g of methacrylic acid, tert- To the mixture, 0.08 g of dodecyl mercaptan and 16 g of an emulsified dispersion of a fixing improver were added, and the mixture was stirred at a stirring speed of 250 rpm and heated to 70 ° C. while flowing nitrogen gas. While maintaining the internal temperature at 70 ° C., an aqueous solution of a polymerization initiator in which 0.82 g of potassium persulfate was dissolved in 100 ml of pure water was added, and polymerization was carried out for 6 hours while maintaining an internal temperature of 70 ° C. and a stirring speed of 250 rpm in a nitrogen stream. Was done.
[0072]
The molecular weight and the amount of carboxyl groups on the latex surface were measured in the same manner as in the synthesis example of the high molecular weight component latex 1.
[0073]
[Low molecular weight componentresinExample of synthesis of latex 1]
1080 ml of distilled water was added to a 2 l four-necked flask equipped with a cooling tube, a thermometer, a stirrer, and a nitrogen inlet tube, and 256.0 g of styrene, 48 g of n-butyl acrylate, 16.0 g of methacrylic acid, tert- 11.0 g of dodecyl mercaptan and 64 g of a fixing improver emulsified dispersion were added, and the mixture was stirred at a stirring speed of 350 rpm and heated to 70 ° C. while flowing nitrogen while flowing nitrogen. While maintaining the internal temperature at 70 ° C., an aqueous solution of a polymerization initiator obtained by dissolving 3.26 g of potassium persulfate in 100 ml of pure water was added, and polymerization was performed for 6 hours while maintaining the internal temperature at 70 ° C. and the stirring speed at 350 rpm in a nitrogen stream. Was done.
In addition, the low molecular weight component resin latex may be abbreviated as a low molecular weight component latex to the extent that misunderstanding does not occur.
[0074]
The molecular weight and the amount of carboxyl groups on the latex surface were measured in the same manner as in the synthesis example of the high molecular weight component latex 1.
[0075]
[Synthesis example of low molecular weight component latex 2]
A low molecular weight component latex 1 was prepared in the same manner as in Synthesis Example 1 except that the amount of added monomer was changed to 249.6 g of styrene, 48 g of n-butyl acrylate, and 22.4 g of methacrylic acid.
[0076]
The molecular weight and the amount of carboxyl groups on the latex surface were measured in the same manner as in the synthesis example of the high molecular weight component latex 1.
[0077]
[Synthesis example of low molecular weight component latex 3]
920 ml of distilled water was added to a 1 l four-necked flask equipped with a cooling tube, a thermometer, a stirrer, and a nitrogen introducing tube, and 384.0 g of styrene, 72 g of n-butyl acrylate, 24.0 g of methacrylic acid, and tert- 16.5 g of dodecyl mercaptan and 96 g of a fixing improver emulsified dispersion were added, and the mixture was stirred until the inside temperature of the flask reached 70 ° C. while stirring at a stirring speed of 250 rpm and flowing nitrogen. While maintaining the internal temperature at 70 ° C., an aqueous solution of a polymerization initiator in which 4.90 g of potassium persulfate was dissolved in 100 ml of pure water was added, and polymerization was performed for 6 hours while maintaining an internal temperature of 70 ° C. and a stirring speed of 250 rpm in a nitrogen stream. Was done.
[0078]
The molecular weight and the amount of carboxyl groups on the latex surface were measured in the same manner as in the synthesis example of the high molecular weight component latex 1.
[0079]
[Synthesis example of low molecular weight component latex 4]
1320 ml of distilled water was added to a 1 l four-necked flask equipped with a cooling tube, a thermometer, a stirrer, and a nitrogen inlet tube, and 64.8 g of styrene, 12 g of n-butyl acrylate, 3.2 g of methacrylic acid, and tert- 2.74 g of dodecyl mercaptan and 16 g of the emulsified dispersion of the fixing improver were added, and the mixture was stirred at a stirring speed of 250 rpm and heated to 70 ° C. while flowing nitrogen while flowing nitrogen. While maintaining the internal temperature at 70 ° C., an aqueous solution of a polymerization initiator in which 0.81 g of potassium persulfate was dissolved in 100 ml of pure water was added, and polymerization was performed for 6 hours while maintaining the internal temperature at 70 ° C. and stirring speed at 350 rpm under a nitrogen stream. Was done.
[0080]
The molecular weight and the amount of carboxyl groups on the latex surface were measured in the same manner as in the synthesis example of the high molecular weight component latex 1.
[0081]
[Synthesis example of low molecular weight component latex 5]
920 ml of distilled water was added to a 1 l four-headed flask equipped with a cooling tube, a thermometer, a stirrer, and a nitrogen inlet tube, and 405.6 g of styrene, 72 g of n-butyl acrylate, 2.4 g of methacrylic acid, tert- 16.3 g of dodecyl mercaptan and 96 g of an emulsifying dispersion of a fixing improver were added, and the mixture was stirred at a stirring speed of 250 rpm and heated to 70 ° C. while flowing nitrogen while flowing nitrogen. While maintaining the internal temperature at 70 ° C., an aqueous solution of a polymerization initiator in which 4.85 g of potassium persulfate was dissolved in 100 ml of pure water was added, and polymerization was performed for 6 hours while maintaining the internal temperature at 70 ° C. and the stirring speed at 350 rpm under a nitrogen stream. Was done.
[0082]
The molecular weight and the amount of carboxyl groups on the latex surface were measured in the same manner as in the synthesis example of the high molecular weight component latex 1.
[0083]
[Table 1]

[0084]
[Toner Synthesis Example 1]
Low-molecular latex surface carboxyl group content A = 2.11 × 10^-4, The amount of carboxyl groups on the surface of the polymer latex B = 2.16 × 10^-4Example of toner production using a combination of latexes.
[0085]
400 g of the low molecular weight component latex 2, 100 g of the high molecular weight component latex 1, 65 g of the pigment dispersion 1 and 340 ml of ion-exchanged water were adjusted to pH = 9.5 using a 5N aqueous sodium hydroxide solution. The mixture was placed in a 2 l 4-head flask equipped with a tube and a temperature sensor, and stirred at 250 rpm. To this, an aqueous electrolyte solution in which 59.4 g of sodium chloride was dissolved in 260 ml of distilled water was added, and further, an aqueous nonionic surfactant solution in which 88 ml of isopropyl alcohol and 9.0 g of Triton X-100 were dissolved in 70 ml of distilled water was sequentially added. After that, the internal temperature was raised to 85 ° C., and the reaction was carried out for 6 hours.
[0086]
After filtration, the reaction solution was re-dispersed by adding distilled water, adjusted to pH = 13 using a 5N aqueous sodium hydroxide solution, washed with water and filtered repeatedly to remove the surfactant and the electrolyte, and then dried. After drying, the particle size was measured using a Coulter counter. The coefficient of variation (CV) of the toner is expressed as follows:₅₀Divided by. This toner is referred to as toner 1.
[0087]
[Toner Synthesis Example 2]
Low-molecular latex surface carboxyl group content A = 1.02 × 10^-4, Amount of carboxyl groups on the surface of the polymer latex B = 1.17 × 10^-4Example of toner production using a combination of latexes.
[0088]
After adjusting 267 g of the low molecular weight component latex 3, 100 g of the high molecular weight component latex 2, 65 g of the pigment dispersion 1 and 473 ml of ion-exchanged water to pH = 9.5 using a 5N aqueous sodium hydroxide solution, a stirrer and cooling were performed. The mixture was placed in a 2 l 4-head flask equipped with a tube and a temperature sensor, and stirred at 250 rpm. To this, an aqueous electrolyte solution in which 46.9 g of sodium chloride was dissolved in 260 ml of distilled water was added, followed by 77 ml of isopropyl alcohol and an aqueous nonionic surfactant solution in which 9.0 g of Triton X-100 was dissolved in 70 ml of distilled water. After that, the internal temperature was raised to 85 ° C., and the reaction was carried out for 6 hours.
[0089]
After filtration, the reaction solution was re-dispersed by adding distilled water, adjusted to pH = 13 using a 5N aqueous sodium hydroxide solution, washed with water and filtered repeatedly to remove the surfactant and the electrolyte, and then dried. After drying, the particle size was measured using a Coulter counter. This toner is referred to as toner 2.
[0090]
[Toner Synthesis Example 3]
Low-molecular latex surface carboxyl group content A = 1.02 × 10^-4, The amount of carboxyl groups on the surface of the polymer latex B = 2.78 × 10^-4Example of toner production using a combination of latexes.
[0091]
After adjusting 267 g of the low molecular weight component latex 3, 200 g of the high molecular weight component latex 3, 65 g of the pigment dispersion 1 and 373 ml of ion-exchanged water to pH = 9.5 using a 5N aqueous sodium hydroxide solution, a stirrer and cooling were performed. The mixture was placed in a 2 l 4-head flask equipped with a tube and a temperature sensor, and stirred at 250 rpm. An aqueous electrolyte solution obtained by dissolving 53.2 g of sodium chloride in 260 ml of distilled water is added thereto, and an aqueous nonionic surfactant solution obtained by dissolving 88 ml of isopropyl alcohol and 9.0 g of Triton X-100 in 70 ml of distilled water is sequentially added. After that, the internal temperature was raised to 85 ° C., and the reaction was carried out for 6 hours.
[0092]
After filtration, the reaction solution was re-dispersed by adding distilled water, adjusted to pH = 13 using a 5N aqueous sodium hydroxide solution, washed with water and filtered repeatedly to remove the surfactant and the electrolyte, and then dried. After drying, the particle size was measured using a Coulter counter. This toner is referred to as toner 3.
[0093]
[Toner Synthesis Example 4]
Low-molecular latex surface carboxyl group content A = 2.11 × 10^-4, The amount of carboxyl groups on the surface of the polymer latex B = 2.16 × 10^-4Example of toner production using a combination of latexes.
[0094]
After adjusting 267 g of the low molecular weight component latex 2, 100 g of the high molecular weight component latex 1, 65 g of the pigment dispersion 2 and 473 ml of ion-exchanged water to pH = 9.5 using a 5N aqueous sodium hydroxide solution, a stirring device and cooling were performed. The mixture was placed in a 2 l 4-head flask equipped with a tube and a temperature sensor, and stirred at 250 rpm. To this, an aqueous electrolyte solution obtained by dissolving 62.5 g of sodium chloride in 260 ml of distilled water was added, and further, an aqueous nonionic surfactant solution obtained by dissolving 80 ml of isopropyl alcohol and 9.0 g of Triton X-100 in 70 ml of distilled water was sequentially added. After that, the internal temperature was raised to 85 ° C., and the reaction was carried out for 6 hours.
[0095]
After filtration, the reaction solution was re-dispersed by adding distilled water, adjusted to pH = 13 using a 5N aqueous sodium hydroxide solution, washed with water and filtered repeatedly to remove the surfactant and the electrolyte, and then dried. After drying, the particle size was measured using a Coulter counter. This toner is referred to as toner 4.
[0096]
[Toner Synthesis Example 5]
Low-molecular latex surface carboxyl group content A = 2.11 × 10^-4, The amount of carboxyl groups on the surface of the polymer latex B = 2.16 × 10^-4Example of toner production using a combination of latexes.
[0097]
After adjusting 267 g of the low molecular weight component latex 2, 100 g of the high molecular weight component latex 1, 65 g of the pigment dispersion 3 and 473 ml of ion-exchanged water to pH = 9.5 using a 5N aqueous sodium hydroxide solution, a stirrer and cooling The mixture was placed in a 2 l 4-head flask equipped with a tube and a temperature sensor, and stirred at 250 rpm. An aqueous electrolyte solution obtained by dissolving 43.8 g of sodium chloride in 260 ml of distilled water is added thereto, and an aqueous nonionic surfactant solution obtained by dissolving 77 ml of isopropyl alcohol and 9.0 g of Triton X-100 in 70 ml of distilled water is sequentially added. After that, the internal temperature was raised to 85 ° C., and the reaction was carried out for 6 hours.
[0098]
After filtration, the reaction solution was re-dispersed by adding distilled water, adjusted to pH = 13 using a 5N aqueous sodium hydroxide solution, washed with water and filtered repeatedly to remove the surfactant and the electrolyte, and then dried. After drying, the particle size was measured using a Coulter counter. This toner is referred to as toner 5.
[0099]
[Toner Synthesis Example 6]
Low-molecular latex surface carboxyl group content A = 2.11 × 10^-4, The amount of carboxyl groups on the surface of the polymer latex B = 2.16 × 10^-4Example of toner production using a combination of latexes.
[0100]
After adjusting 267 g of the low molecular weight component latex 2, 100 g of the high molecular weight component latex 1, 65 g of the pigment dispersion 4 and 473 ml of ion-exchanged water to pH = 9.5 using a 5N aqueous sodium hydroxide solution, a stirring device and a cooling device were used. The mixture was placed in a 2 l 4-head flask equipped with a tube and a temperature sensor, and stirred at 250 rpm. An aqueous electrolyte solution obtained by dissolving 46.9 g of sodium chloride in 260 ml of distilled water is added thereto, and an aqueous nonionic surfactant solution obtained by dissolving 80 ml of isopropyl alcohol and 9.0 g of Triton X-100 in 70 ml of distilled water is sequentially added. After that, the internal temperature was raised to 85 ° C., and the reaction was carried out for 6 hours.
[0101]
After filtration, the reaction solution was re-dispersed by adding distilled water, adjusted to pH = 13 using a 5N aqueous sodium hydroxide solution, washed with water and filtered repeatedly to remove the surfactant and the electrolyte, and then dried. After drying, the particle size was measured using a Coulter counter. This toner is referred to as toner 6.
[0102]
[Comparative Toner Synthesis Example 1]
Low-molecular latex surface carboxyl group content A = 0.26 × 10^-4, The amount of carboxyl groups on the surface of the polymer latex B = 2.78 × 10^-4Example of toner production using a combination of latexes.
[0103]
After adjusting 267 g of the low molecular weight component latex 5, 200 g of the high molecular weight component latex 3, 65 g of the pigment dispersion 1 and 373 ml of ion-exchanged water to pH = 9.5 using a 5N aqueous sodium hydroxide solution, a stirrer and cooling were performed. The mixture was placed in a 2 l 4-head flask equipped with a tube and a temperature sensor, and stirred at 250 rpm. An aqueous electrolyte solution obtained by dissolving 43.8 g of sodium chloride in 260 ml of distilled water is added thereto, and an aqueous nonionic surfactant solution obtained by dissolving 77 ml of isopropyl alcohol and 9.0 g of Triton X-100 in 70 ml of distilled water is sequentially added. After that, the internal temperature was raised to 85 ° C., and the reaction was carried out for 6 hours.
[0104]
After filtration, the reaction solution was re-dispersed by adding distilled water, adjusted to pH = 13 using a 5N aqueous sodium hydroxide solution, washed with water and filtered repeatedly to remove the surfactant and the electrolyte, and then dried. After drying, the particle size was measured using a Coulter counter. This toner is referred to as comparative toner 1.
[0105]
[Comparative Toner Synthesis Example 2]
Low-molecular latex surface carboxyl group content A = 2.11 × 10^-4, The amount of carboxyl groups on the surface of the polymer latex B = 0.37 × 10^-4Example of toner production using a combination of latexes.
[0106]
400 g of the low molecular weight component latex 2, 100 g of the high molecular weight component latex 4, 65 g of the pigment dispersion 1 and 340 ml of ion-exchanged water were adjusted to pH = 9.5 using a 5N aqueous solution of sodium hydroxide. The mixture was placed in a 2 l 4-head flask equipped with a tube and a temperature sensor, and stirred at 250 rpm. An aqueous electrolyte solution obtained by dissolving 42.5 g of sodium chloride in 260 ml of distilled water is added thereto, and an aqueous nonionic surfactant solution obtained by dissolving 77 ml of isopropyl alcohol and 9.0 g of Triton X-100 in 70 ml of distilled water is sequentially added. After that, the internal temperature was raised to 85 ° C., and the reaction was carried out for 6 hours.
[0107]
After filtration, the reaction solution was re-dispersed by adding distilled water, adjusted to pH = 13 using a 5N aqueous sodium hydroxide solution, washed with water and filtered repeatedly to remove the surfactant and the electrolyte, and then dried. After drying, the particle size was measured using a Coulter counter. The coefficient of variation (CV) of the toner is expressed as follows:₅₀Divided by. This toner is referred to as Comparative Toner 2.
[0108]
[Comparative Toner Synthesis Example 3]
Low-molecular latex surface carboxyl group content A = 1.84 × 10^-4, The amount of carboxyl groups on the surface of the polymer latex B = 0.37 × 10^-4Example of toner production using a combination of latexes.
[0109]
400 g of the low molecular weight component latex 1, 100 g of the high molecular weight component latex 4, 65 g of the pigment dispersion 1 and 340 ml of ion-exchanged water were adjusted to pH = 9.5 using a 5N aqueous sodium hydroxide solution. The mixture was placed in a 2 l 4-head flask equipped with a tube and a temperature sensor, and stirred at 250 rpm. An aqueous electrolyte solution obtained by dissolving 38.8 g of sodium chloride in 260 ml of distilled water was added thereto, and an aqueous nonionic surfactant solution obtained by dissolving 77 ml of isopropyl alcohol and 9.0 g of Triton X-100 in 70 ml of distilled water was sequentially added. After that, the internal temperature was raised to 85 ° C., and the reaction was carried out for 6 hours.
[0110]
After filtration, the reaction solution was re-dispersed by adding distilled water, adjusted to pH = 13 using a 5N aqueous sodium hydroxide solution, washed with water and filtered repeatedly to remove the surfactant and the electrolyte, and then dried. After drying, the particle size was measured using a Coulter counter. This toner is referred to as comparative toner 3.
[0111]
[Comparative Toner Synthesis Example 4]
Low-molecular latex surface carboxyl group content A = 0.26 × 10^-4, The amount of carboxyl groups on the surface of the polymer latex B = 0.37 × 10^-4Example of toner production using a combination of latexes.
[0112]
After adjusting 267 g of the high molecular weight component latex 5, 100 g of the low molecular weight component latex 4, 65 g of the pigment dispersion liquid 1 and 473 ml of ion exchange water to pH = 9.5 using a 5N aqueous sodium hydroxide solution, a stirring device and cooling were performed. The mixture was placed in a 1-liter four-necked flask equipped with a tube and a temperature sensor, and stirred at 250 rpm. To this, an aqueous electrolyte solution in which 25.0 g of sodium chloride was dissolved in 260 ml of distilled water was added, and further, an aqueous nonionic surfactant solution in which 57 ml of isopropyl alcohol and 9.0 g of Triton X-100 were dissolved in 70 ml of distilled water was sequentially added. Thereafter, the internal temperature was raised to 85 ° C., and the reaction was carried out for 6 hours.
[0113]
After filtration, the reaction solution was re-dispersed by adding distilled water, adjusted to pH = 13 using a 5N aqueous sodium hydroxide solution, washed with water and filtered repeatedly to remove the surfactant and the electrolyte, and then dried. After drying, the particle size was measured using a Coulter counter. This toner is referred to as comparative toner 4.
[0114]
[Comparative Toner Synthesis Example 5]
Low molecular latex surface carboxyl group content A = 4.25 × 10^-4, The amount of carboxyl groups on the surface of the polymer latex B = 4.31 × 10^-4Example of toner production using a combination of latexes.
[0115]
The low molecular weight component latex 4 was adjusted to 600 g, the high molecular weight component latex 5 to 150 g, the pigment dispersion 1 to 25 g, and 90 ml of ion exchanged water to pH = 9.5 using a 5N aqueous sodium hydroxide solution. The mixture was placed in a 1-liter four-necked flask equipped with a tube and a temperature sensor, and stirred at 250 rpm. An aqueous electrolyte solution in which 79.4 g of sodium chloride was dissolved in 260 ml of distilled water was added thereto, and an aqueous nonionic surfactant solution in which 93 ml of isopropyl alcohol and 9.0 g of Triton X-100 were dissolved in 70 ml of distilled water was sequentially added. Thereafter, the internal temperature was raised to 85 ° C., and the reaction was carried out for 6 hours.
[0116]
After filtration, the reaction solution was re-dispersed by adding distilled water, adjusted to pH = 13 using a 5N aqueous sodium hydroxide solution, washed with water and filtered repeatedly to remove the surfactant and the electrolyte, and then dried. After drying, the particle size was measured using a Coulter counter. This toner is referred to as comparative toner 5.
[0117]
[Table 2]

[0118]
Evaluation 1
Using toners 1 to 6 of the present invention and comparative toners 1 to 5, 2 parts by weight of hydrophobic silica and 1 part by weight of titanium oxide were added to and mixed with 100 parts by weight of the toner. 95 parts by weight of ferrite particles (carrier, average particle diameter 60 μm) surface-coated with a methyl acid / styrene copolymer (MAA / St = 7/3 weight ratio) are mixed, and the developing agents 1 to 3 of the present invention and comparative development Agents 1-4. The charge amount when this developer was shaken with a shaker for 60 minutes was measured by a blow-off method. The measurement was carried out at low temperature and low humidity (LL) and at high temperature and high humidity (HH), and the difference in charge amount between LL and HH was defined as the environmental difference.
[0119]
Table 3 shows the measurement results.
[0120]
[Table 3]

[0121]
As a result, the surface carboxyl group content of the low molecular weight component latex was 0.6 × 10^-4Above 3.5 × 10^-4Hereinafter, the surface carboxyl group content of the high molecular weight component latex is 0.8 × 10^-44 × 10 or more^-4In the following, the amount of charge of the toner in which | AB |
[0122]
Evaluation 2
Using a fixing roller having a temperature of 180 ° C. and using the above developer, a Konica color copier 9028 was modified and a long run was performed. The conditions are as shown below. A laminated organic photoreceptor was used as the photoreceptor.
[0123]
Photoconductor surface potential = -550V
DC bias = -250V
AC bias = Vp-p: -50 to -450V
Alternating electric field frequency = 1800Hz
Dsd = 300 μm
Press regulating force = 10 gf / mm
Pressing control rod = SUS416 (made of magnetic stainless steel) / 3 mm in diameter
Developer layer thickness = 150 μm
Developing sleeve = 20mm
Environmental conditions were high-temperature and high-humidity (33 ° C / 80% RH). While printing a solid black image every 5,000 sheets, an image with a pixel rate of 1% was continuously printed on 100,000 sheets. The presence or absence of dirt was compared.
[0124]
The image stain was evaluated by the degree to which toner adheres to a developing device or the like and white streaks or the like occur in a solid black image.
[0125]
Table 4 shows the measurement results.
[0126]
[Table 4]

[0127]
From this result, it is clear that the comparative toners 1 and 2 have more image stains than the toners 1 to 6 in the present invention.
[0128]
【The invention's effect】
According to the present invention, the resin particles having different molecular weights in the toner can be localized in the toner particles to improve the mechanical strength of the toner particles. Further, toner particles having a small particle size and a narrow particle size distribution can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view illustrating an image forming method according to the present invention.
[Explanation of symbols]
1 Laser light source
4 Photoconductor drum
5 Charging unit
6 Developing unit
7 Transfer pole
11 Cleaning device
13 Elastic rubber blade

Claims (6)

Low molecular weight component resin latex Weight fraction molecular weight on a molecular weight distribution measurement by GPC has a peak between 1,000 to 50,000, is Weight fraction molecular weight having a peak between 80,000～700,000 In a toner for developing an electrostatic image formed by mixing a high molecular weight component resin latex, a colorant and a fixing improver, and coagulating and fusing, the amount of carboxyl groups present on the surface of the low molecular weight component resin latex is represented by A [ mol / g], and the following formula (1) is satisfied when the amount of carboxyl groups present on the surface of the high molecular weight resin latex is B [mol / g].
0.6 × 10 ⁻⁴ ≦ A ≦ 3.5 × 10 ⁻⁴
0.8 × 10 ⁻⁴ ≦ B ≦ 4 × 10 ⁻⁴
1 × 10 ⁻⁶ ≦ | A−B | ≦ 2 × 10 ⁻⁴ Equation (1) Low molecular weight component resin latex Weight fraction molecular weight on a molecular weight distribution measurement by GPC has a peak between 1,000 to 50,000, is Weight fraction molecular weight having a peak between 80,000～700,000 In a toner for developing an electrostatic image, which is produced by mixing a high molecular weight component resin latex, a colorant and a fixing improver and aggregating and fusing, the amount of carboxyl groups present on the surface of the low molecular weight component resin latex is represented by A [ mol / g], and the following formula (2) is satisfied when the amount of carboxyl groups present on the surface of the high molecular weight resin latex is B [mol / g].
0.6 × 10 ⁻⁴ ≦ A ≦ 3.5 × 10 ⁻⁴
0.8 × 10 ⁻⁴ ≦ B ≦ 4 × 10 ⁻⁴
1 × 10 ⁻⁶ ≦ ^BA ≦ 2 × 10 ⁻⁴ Formula (2) 3. The electrostatic image developing toner according to claim 1, wherein the low molecular weight resin latex and the high molecular weight resin latex contain an ionic monomer unit having a carboxyl group. 3. An image forming method for visualizing an electrostatic latent image formed on a photoreceptor to form a toner image, wherein the toner is the toner for developing an electrostatic image according to claim 1 or 2. . 3. An image forming method for transferring a toner image formed on a photoreceptor, wherein the toner is the toner for developing an electrostatic image according to claim 1 or 2. 3. The electrostatic image developing toner according to claim 1, wherein the toner image formed on the photoconductor is transferred onto a transfer material, and then the toner remaining on the photoconductor is cleaned. An image forming method, characterized in that:

Images