JP2005049511A - Electrostatic charge image developing toner and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new method for manufacturing chemical toner having a sharp particle size distribution with high yield in the method for manufacturing the chemical toner by using a polyester resin as a binder resin prepared by reacting an aliphatic alcohol compound as an alcohol component. <P>SOLUTION: The method for manufacturing electrostatic charge image developing toner includes steps of: (i) by dissolving or dispersing a polyester resin in an organic solvent to prepare a resin solution; (ii) preparing a suspension liquid having fine particles of the above resin solution suspended in an aqueous medium; (iii) producing agglomerates of the fine particles; (iv) removing the organic solvent; and (v) separating and drying the agglomerates. In this method, the polyester resin used is obtained by making (1) polybasic acids containing isophthalic acids or lower alkyl esters by ≥30 mol% of the whole acid component react with (2) aliphatic polyhydric alcohol. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００８１】
【表２】

表中の表示は以下の通り。
ＴＰＡ：テレフタル酸
ＤＥＧ：ジエチレングリコール
ＮＰＧ：ネオペンチルグリコール
ＥＧ：エチレングリコール
ＩＰＡ：イソフタル酸
ＴＭＰ：トリメチロールプロパン
カージュラｅ：シェルジャパン製アルキルグリシジルエステル（エポキシ当量：２５０）
エピクロンｎ−６９５：大日本インキ化学工業（株）製多官能型クレゾールノボラックエポキシ樹脂（エポキシ当量：２２０）
エピクロン７２０：大日本インキ化学工業（株）製アルコールエーテル型エポキシ樹脂（エポキシ当量１５０）
エピクロン８３０：大日本インキ化学工業（株）製ビスフェノールｆ型エポキシ樹脂（エポキシ当量１７０）
【００８２】
（離型剤分散液の調製例）
カルナバワックス「カルナバワックス １号」（加藤洋行輸入品）３０部とポリエステル樹脂（表１の合成例９）７０部とを加圧ニーダーで混練後、該混練物とメチルエチルケトン１８５部とをボールミルに仕込み、８時間攪拌した後取り出し、固形分含有量を３５重量％に調整し、離型剤の微分散液Ｗ１を得た。同様に下記組成の離型剤微分散液を得た。
【００８３】
【表３】
表２

【００８４】
（着色剤マスター溶液の調製例）
着色顔料とポリエステル樹脂とを有機溶剤（メチルエチルケトン）中に添加し、デェスパーにてプレ分散を行った後、モーターミルＭ−１０００（米国アイガー社製）で湿式分散を行い、各着色剤のマスター溶液を調整した。表３、４に各着色剤マスター溶液の配合、分散条件、最終的に得られたマスター溶液の固形分含有量を示した。
【００８５】
【表４】
表３．着色剤マスター溶液の配合表１
（使用ポリエステル樹脂：表１の合成例９）

【００８６】
【表５】
表４．着色剤マスター溶液の配合表２
（着色剤はカーボン）

表３、４に示した着色剤は以下の通りである。
カーボン：キャボット社製カーボンブラック「Ｅｌｆｔｅｘ−８」
黒色顔料：チタン工業社製黒色顔料「ＥＴＢ−１００」
シアン：大日本インキ化学工業（株）社製シアン顔料「Ｋｅｔ−１１１」（Ｐｉｇｍｅｎｔ Ｂｌｕｅ １５：３）
イエロー：チバスペシャリティケミカルズ社製イエロー顔料「Ｃｒｏｍｏｐｈｔａｌ Ｙｅｌｌｏｗ ３Ｇ」（Ｐｉｇｍｅｎｔ Ｙｅｌｌｏｗ ９４）
マゼンタ：大日本インキ化学工業（株）社製マゼンタ顔料「Ｍａｇｅｎｔａ Ｒ」（Ｐｉｇｍｅｎｔ Ｒｅｄ １２２）
【００８７】
（帯電制御剤分散液の調製例）
正帯電制御剤であるＮ−０４；ボントロンＮ−０４（オリエント化学製、ニグロシン染料）とメチルエチルケトンを３０／７０の重量比率で配合し、モーターミルＭ−１０００（米国アイガー社製）で分散を行い、固形分含有量を３０重量％に調整し、帯電制御剤分散液Ｅ−１を得た。
【００８８】
（ミルベースの調製）
上記離型剤分散液、着色剤マスターチップ、希釈樹脂（追加樹脂）、メチルエチルケトンを、固形分含有量が５６％、温度条件が３０〜４０℃の範囲でデスパーにより３時間の間混合し、溶解・分散を行った。得られた混合物は、固形分含有量を５５％に調整してミルベースとした。作製したミルベースの配合を表５、６に示す。
【００８９】
【表６】
表５−１．ブレンド系のミルベース配合表

【００９０】
【表７】
表５−２．ブレンド系のミルベース配合表

【００９１】
【表８】
表６．単一樹脂系のミルベース配合表

【００９２】
＜合一法によるトナーの製造＞
（実施例）
攪拌翼としてマックスブレンド翼を有する円筒型の２ＬセパラブルフラスコにミルベースＭＢ５を５４５．５部仕込み、次いで１規定アンモニア水４７．４部（カルボン酸に対する当量は１．２）を加えて、スリーワンモーターにより２１０ｒｐｍにて十分に攪拌した後、脱イオン水１３３部を加え、さらに攪拌を行い、温度を２３℃に調製した。ついで、同条件下で１３３部の脱イオン水を滴下して転相乳化により微粒子分散体を作製した。この時の攪拌翼の周速は０．７１ｍ／ｓであった。次に、脱イオン水２８０部を加えて（１規定アンモニア水と水の総量が５９３部となる量の脱イオン水量）溶剤量を調整した。
【００９３】
次いで、アニオン型乳化剤であるエマール０（花王社製）の２．８部を水３０部に希釈して添加した。その後、温度を２５℃に、また回転数を１５８ｒｐｍに調整し、５．２％の硫酸アンモニュウムの水溶液を粒径が５．５μｍに成長するまで滴下し、その後、同条件で粒径が７μｍに成長するまで攪拌を続け合一操作を終了した。この時の硫酸アンモニュウムの添加量は３００部であった。また、攪拌翼の周速は０．５４ｍ／ｓであった。なお、いずれの実施例、比較例においても７μｍのトナー母体粒子が得られるよう、適宜硫酸アンモニュウムの水溶液濃度、及び添加量を調整した。
【００９４】
＜ミルベース安定性の評価方法＞
表５−１、表５−２、６の配合で得られた各種ミルベースの安定性は、２５℃で静置した後の溶液粘度の値をＢ型粘度計で測定し、ミルベース作製から一日後の粘度が大幅に上昇している場合を×、一週間後の粘度が上昇している物を△、一週間後の粘度変化がほとんど見られない物を○とした。二週間後の粘度変化が見られない物を◎とした。
【００９５】
＜トナー性状の評価方法＞
得られたスラリーは、減圧下有機溶剤を留去した後、リスラリーによる洗浄を３回行った後、凍結乾燥機を用いて乾燥を行い、トナー母粒子を得た。次に、微量の界面活性剤を含む水の中にトナー母粒子を懸濁させることにより試料を作製する。次いでコールターカウンターマルチサイザーＴＡＩＩを用いて該母粒子の粒径、粒度分布を測定した。
【００９６】
平均円形度は、トナー粒子のＳＥＭ（走査型電子顕微鏡）写真を撮影し、それを測定し計算することによっても求めることができるが、本発明においては、東亜医用電子（株）製フロー式粒子像分析装置ＦＰＩＰ−１０００により求める。フロー式粒子像分析装置ＦＰＩＰ−１０００とは、トナー粒子等の微粒子の大きさや形状を撮像する装置であり、粒子の撮像は以下の通りに行われる。
【００９７】
まず、微量の界面活性剤を含む水の中にトナー粒子を懸濁させることにより試料を作製する。次いで、この試料をフロー式粒子像分析装置ＦＰＩＰ−１０００中に設けられた、透明且つ扁平なセル中に流下させる。このセルの片側にはパルス光を発する光源が設置されており、更に、セルを挟んで反対側にはその光源に正対するように撮像用カメラが設けられている。ＦＰＩＰ−１０００のセル中を流下する試料中のトナー粒子は、パルス光が照射されることにより、セルを夾んで光源と正対するカメラにより静止画像として捉えられる。
【００９８】
このようにして撮像されたトナー粒子の像を基にして、画像解析装置により各トナー粒子の輪郭が抽出され、トナー粒子像の投影面積や周囲長（トナー粒子投影像の周長）が算出される。更に、算出されたトナー粒子像の投影面積から、それと同等の面積を有する円の円周の長さ（トナー粒子投影面積と同じ面積の円の周長）が算出される。上記の平均円形度は、このように算出されたトナー粒子投影面積と同じ面積の円の周長をトナー粒子投影像の周長で除したものである。
【００９９】
上記装置で測定する際の条件は以下の通り。
（１）トナー粒子の懸濁液の作製
水２０ｇに対し界面活性剤（エルクリヤー（中外写真薬品（株）製））０．１ｇを添加し、更に試料であるトナー０．０４ｇを添加し、超音波分散機でトナー粒子を水中に懸濁させる。
（２）測定条件
測定温度；２５℃
測定湿度；６０％
測定トナー粒子数；５０００±２０００個
【０１００】
＜トナー転写効率の評価方法＞
実施例、比較例で得られた各母トナーに対し、疎水性シリカを、母トナー１００質量部に対し、１質量部をヘンシェルミキサーで外添した後、シリコン樹脂被覆フェライトキャリア９７部に対し、該トナー３部からなる現像剤を調整後、転写効率を比較した。転写効率は、市販の複写機を用いて、ベタ画像を現像し、感光体上のベタ画像が転写部を５０％通過したところで複写機を停止させる。その後、感光体上の未転写画像・転写後の画像をそれぞれテープにて完全に剥離し、未転写画像のトナー量と転写後のトナー量を測定し、下記式より転写効率を算出する。
転写効率（％）＝１００―転写後のトナー量／未転写画像のトナー量×１００
その結果、９５％以上の転写効率を○、９０％以上９５％未満の転写効率を△、９０％未満の転写効率を×とした。
【０１０１】
＜トナー熱特性の評価方法＞
表９における、トナー溶融粘度「Ｔ１／２温度」は、前述したように島津製作所製フローテスタ（ＣＦＴ−５００）を用いて、ノズル径１．０ｍｍΦ×１．０ｍｍ、単位面積（ｃｍ^２ ）当たりの荷重０．９８ＭＰａ、毎分６℃の昇温速度で測定した値である。また、ガラス転移温度である「Ｔｇ」（℃）は 、島津製作所製示差走査熱量計（ＤＳＣ−５０）を用い、セカンドラン法により毎分１０℃の昇温速度で測定した値である。また、耐熱保存性は、トナー母粒子１０質量部を１００ｃｃの硝子製容器に入れ、密閉した後、５０℃の環境下に１２時間静置した後、取り出して凝集性の有無を判断した。堅い凝集体のある物を×、指でほぐれる程度の凝集体がある物を△、凝集体のない物を○とした。
【０１０２】
オフセット幅、及び定着開始温度については、予め、実施例および比較例のトナー母粒子に対し疎水性シリカを外添し、ついでシリコン樹脂被覆フェライトキャリアとを混合することで現像剤を調整した。ついで市販複写機改造機にてＡ−４紙サイズの未定着画像サンプルを作製し、印刷紙を９０ｍｍ／秒のスピードで、リコーイマジオＤＡ−２５０のヒートロールに通して定着を行った。オフセット幅については、オフセットを発生しない上限値と下限値との温度範囲によって示した。また、定着開始温度は、定着後の画像に粘着テープを貼り、剥離後のＩＤ（画像濃度）が元のＩＤの９０％以上であって、かつオフセットの発生が見られないときのヒートロールの表面温度で示した。
【０１０３】
【表９】
表７−１．造粒条件

【０１０４】
【表１０】
表７−２．造粒条件

ミルベースの安定性は、樹脂の全酸成分中のイソフタル酸含有量と相関があり、３０ｍｏｌ％よりも少ないと容易に粘度変化を生じ、実用上粒子を安定して製造することができないことがわかる。
【０１０５】
【表１１】
表８−１．トナーの性状

【０１０６】
【表１２】
表８−２．トナーの性状

【０１０７】
実施例８については、転相乳化後微粒子を作製した後に、通常の条件よりも薄い濃度の電解質を滴下し、粒径が５μｍとなるまで合一を進めた。その後、濃度を上げた電解質を滴下することで合一を更に進めることで、平均円形度の低い、略球形の粒子を得た。
平均円形度の高い粒子はいずれも転写効率、粉体流動性が良好である。平均円形度の低い粉砕法トナーは、いずれも転写効率、粉体流動性とも明らかに劣る。粒子形状をある一定値以上保持することは、上記結果から現像特性に有利であることがわかる。
【０１０８】
【表１３】
表９−１．熱特性評価結果

【０１０９】
【表１４】
表９−２．熱特性評価結果

【０１１０】
ポリエステル樹脂の全酸成分中のイソフタル酸含有量が３０ｍｏｌ％未満である比較例１、２、３、４、５は、表７のミルベース安定性の不安定化のみならず、表８で示したように微粒子及び粗大粒子が多量に発生し、粒度分布がブロードになる。また、同時に凝集物の発生が見られ、その結果、表９で示す熱特性、特にオフセット幅、定着開始温度も実施例のサンプルに比べ、低下することから、実用上安定して使用できないレベルにある。これに対し、実施例の各サンプルは、粒度分布、形状とも良好なレベルにある。実施例の各サンプルは、各熱特性のバランスが達成されており、特に定着開始温度は良好であることがわかる。さらに、溶融粘度の異なる架橋樹脂と直鎖状樹脂をブレンドすることにより、オフセット幅、定着開始温度が更に改善されることがわかる。
【０１１１】
【発明の効果】
以上説明したように本発明の製造方法によれば、ミルベースの安定性に優れ、粒度分布がシャープなケミカルトナーを製造することができる。また、本製造方法で得られた静電荷像現像用トナーは、球形で、かつシャープな粒度分布を有し、幅広い温度領域での耐オフセット性、及び低温定着性を達成することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a toner for developing an electrostatic charge image that is suitably used for a copying machine, a printer, a fax machine, and the like, and further used for a toner jet type printer.
[0002]
[Prior art]
Various resins can be used as the binder resin for the toner, but the main component is an alkylene oxide adduct of bisphenol A, which has excellent low-temperature fixability, a tough image after fixing, and a relatively high glass transition temperature. A polyester resin contained as a component is preferably used. However, existing polyester resins that use bisphenol A alkylene oxide adducts as the main raw material lack a balance between low-temperature fixability and offset resistance in a wide temperature range, and bisphenol A alkylene oxide adducts. There is concern that trace amounts of bisphenol A remaining during production may affect environmental hormones. Furthermore, the alkylene oxide adducts of bisphenol A are expensive, and therefore resins using such raw materials are used. The problem is that the toner used is expensive.
[0003]
In order to improve this, a novel polyester resin using an aliphatic polyhydric alcohol as a main component has been proposed (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).
[0004]
On the other hand, development of a toner (hereinafter referred to as a chemical toner) by a wet method such as an emulsification dispersion method or a polymerization method has been actively conducted. In particular, the emulsification dispersion method makes it easy to reduce the particle size and spheroidization of the toner, and in addition to the polymerization method, (1) the selection range of the binder resin is wider, and the polyester resin and the epoxy resin. (2) It is easy to reduce residual monomers and is advantageous for low VOC. (3) It is possible to arbitrarily change the concentration of the coloring agent from a low concentration to a high concentration. It has the advantage of being able to. In addition, the dispersion of pigments, etc. in the wet process eliminates molecular chains, and provides advantages such as offset resistance, low-temperature fixability in the wide area inherent to the resin, and good heat-resistant storage stability by maintaining the glass transition temperature. It is possible to make use of it.
[0005]
As a conventional technique relating to a toner production method using an emulsification dispersion method, for example, a colorant and a polyester resin that becomes an anionic self-water-dispersible resin are dispersed in an organic solvent, and then subjected to phase inversion emulsification. A method for producing particles is disclosed (for example, see Patent Document 4). In addition, the amount of the bisphenol A alkylene oxide adduct is suppressed as much as possible, and a polyester resin and a colorant, which are reacted with a polyvalent carboxylic acid and an aliphatic polyhydric alcohol as main components, are dispersed in an organic solvent. A method for producing toner particles by emulsification is disclosed (for example, see Patent Document 5). Furthermore, a method for producing a toner with a sharp particle size distribution in a high yield by dispersing a colorant and a polyester resin in an organic solvent, then performing phase inversion emulsification, and further performing a coalescing step is disclosed. (For example, refer to Patent Document 6).
[0006]
Recently, further improvements in print image quality such as improvement in resolution and gradation of a print image with toner are desired. Accordingly, in the field of chemical toners, it has become necessary to develop a method for producing a toner having a sharper particle size distribution. In particular, the development of a toner that has a sharp particle size distribution and satisfies the requirements of environmental safety, good low-temperature fixability, offset resistance in a wide temperature range, low cost, etc. is strongly desired. Yes.
[0007]
As a toner for satisfying such a requirement, there is a chemical toner using a polyester resin using an aliphatic polyhydric alcohol as a raw material in place of an alkylene oxide adduct of bisphenol A. By the way, in the production of chemical toners, the composition of the resin slightly affects the stability of the emulsified dispersion and greatly affects the particle size distribution, shape, yield and the like of the toner obtained as a product. However, in the above-described conventional technology, sufficient studies have not been made on the technology relating to the emulsion stability when producing such a chemical toner. Therefore, a chemical toner manufacturing method having a sharp particle size distribution and satisfying environmental safety, good low-temperature fixability, offset resistance in a wide temperature range, cost reduction, etc. is still satisfactory. No level technology has been found.
[0008]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-15199
[Patent Document 2]
Japanese Patent Laid-Open No. 2001-60018
[Patent Document 3]
JP 2001-272817 A
[Patent Document 4]
JP-A-8-21655
[Patent Document 5]
JP 2002-287424 A
[Patent Document 6]
JP 2003-122051 A
[0009]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and its object is to provide a sharp particle size distribution in a chemical toner manufacturing method using a polyester resin obtained by reacting an aliphatic alcohol compound as an alcohol component as a binder resin. It is to provide a novel production method for producing a high-quality chemical toner with high yield. Another object of the present invention is to solve the above-mentioned problems and satisfy a spherical shape, environmental safety, good low-temperature fixability, offset resistance in a wide temperature range, cost reduction, and the like. The object is to provide a method for producing a chemical toner. Another object of the present invention is to provide a low-cost chemical toner having a sharp particle size distribution and having environmental safety, good low-temperature fixability, and offset resistance in a wide temperature range.
[0010]
[Means for Solving the Problems]
As a result of extensive research, the present inventors have found a method for producing a toner for developing an electrostatic image that solves the above-mentioned problems, and have completed the present invention. That is, the present invention includes (i) a step of producing a resin solution by dissolving or dispersing a polyester resin having a carboxyl group in an organic solvent, and (ii) mixing the resin solution with an aqueous medium in the presence of a basic compound. (Iii) Next, an emulsifier is added, and then an electrolyte is added to form a unity of the microparticles by forming a suspension in which the microparticles of the resin solution are suspended in the aqueous medium. A process for producing a toner for developing an electrostatic charge image, comprising: (iv) a step of removing the organic solvent in the unity, and (v) a step of separating the unity from the aqueous medium and drying. As the polyester resin,
1) Polybasic acids containing 30 mol% or more of isophthalic acid or a lower alkyl ester thereof based on the total acid component, and
2) aliphatic polyhydric alcohol,
The present invention provides a method for producing a toner for developing an electrostatic charge image, which comprises using a polyester resin obtained by reacting the above.
[0011]
The present invention also includes (i) a step of producing a resin solution by dissolving or dispersing a polyester resin having a carboxyl group in an organic solvent, and (ii) mixing the resin solution with an aqueous medium in the presence of a basic compound. (Iii) Next, an emulsifier is added, and then an electrolyte is added to form a unity of the microparticles by forming a suspension in which the microparticles of the resin solution are suspended in the aqueous medium. (Iv) a toner for developing an electrostatic charge image produced by sequentially performing a step of (iv) removing the organic solvent in the unity, and (v) separating the unity from the aqueous medium and drying. The polyester resin is
1) Polybasic acids containing 30 mol% or more of isophthalic acid or a lower alkyl ester thereof based on the total acid component, and
2) aliphatic polyhydric alcohol,
The present invention provides a toner for developing an electrostatic charge image, which is a polyester resin obtained by reacting the above.
[0012]
In the toner, the binder resin occupies 80 to 90% of the constituent raw materials. Therefore, it is well known that the binder resin has a great influence on environmental safety, cost, and thermal characteristics. Furthermore, in the chemical toner manufacturing methods described in Patent Document 4, Patent Document 5, and Patent Document 6, it is possible to obtain a very sharp particle size distribution. However, according to the study by the present inventors, a chemical toner is produced by the above production method using a polyester resin containing an aliphatic alcohol compound as a main component and not using an alkylene oxide adduct of bisphenol A as a main component. Attempts to produce the product showed that not only particles with a sharp particle size distribution could be obtained, but also the viscosity change of the resin solution was so drastic that practically stable production could not be performed. As a result of diligently examining the cause, the polybasic acid compound used in the production of the polyester resin can solve the above problem by using 30 mol% or more of isophthalic acid or its lower alkyl ester with respect to the total acid component. The headline and the present invention were completed.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail. The production method of the present invention comprises the following steps.
First step: A step (i) of producing a resin solution by dissolving or dispersing a polyester resin having a carboxyl group as a raw material in an organic solvent is performed, and then an aqueous medium is added to the resin solution in the presence of a basic compound. Is added to form a suspension (fine particles) of the resin solution in the aqueous medium.
Second step: A step (iii) of forming a unity of fine particles in the suspension by sequentially adding a dispersion stabilizer and an electrolyte to the aqueous medium is performed, and then the organic solvent in the unity is removed. Step (iv) of removing is performed.
Third step: Step (V) for producing the toner by separating the union after removal of the solvent from the aqueous medium and drying it.
The above three steps.
[0014]
In the present invention, aggregating and integrating the fine particles of the resin solution containing the organic solvent generated in the step (ii) is referred to as “unification”, and the step (iii) is referred to as “unification step”. Say. Further, the particles formed by the step (iii) are referred to as “integrated”. Furthermore, a method for producing toner through a coalescence process is referred to as a “manufacturing method”.
[0015]
In the coalescence method, the particle size and particle size distribution are substantially determined in the first and second steps. In order to obtain a sharp particle size distribution through this process, it is necessary to contain 30 mol% or more of isophthalic acid or a lower alkyl ester thereof in the total acid component of the polyester resin used in the present invention. If the content of isophthalic acid or its lower alkyl ester is less than 30 mol%, the resin solution obtained in step (i) of the first step causes a viscosity change due to crystallization, so that the suspension is stable in step (ii). As a result, the particle size distribution in the second step becomes broad. In addition, since the resin particles are not uniformly coalesced, there is a problem that the particle strength is reduced by voids generated after drying. When isophthalic acid or its lower alkyl ester is contained in an amount of 30 mol% or more, crystallization in the resin solution is suppressed, so that the stability of the resin solution is improved and particles having a sharp particle size distribution can be obtained. The content of isophthalic acid or its lower alkyl ester is preferably in the range of 30 to 70 mol%. More preferably, it is the range of 30-60 mol%. An increase in the content of isophthalic acid or its lower alkyl ester is not preferable because the glass transition temperature tends to decrease.
[0016]
In the first step, a polyester resin is introduced into an organic solvent and dissolved or dispersed to prepare a resin solution containing the polyester resin and the organic solvent. In this case, a release agent, a colorant, or other additives can be used together with a polyester resin or the like as necessary, but any of them needs to be finely dispersed or dissolved below the toner particle size.
[0017]
As a means for dissolving or dispersing the polyester resin and various additives such as a release agent and a colorant which are added to the organic solvent as necessary, the following method is preferably used.
[0018]
(1) A mixture containing various additives such as the above-mentioned polyester resin, mold release agent, colorant, etc., using a pressure kneader, a heated two-roll, two-screw extrusion kneader or the like, In addition, the mixture is heated and kneaded at a temperature lower than the thermal decomposition temperature. Thereafter, the kneaded chips obtained are dissolved or dispersed in an organic solvent by a stirrer such as a desper or a disperser using media.
Or
(2) A polyester resin and various additives such as a release agent and a colorant are mixed with an organic solvent, and this is wet-kneaded by a ball mill or the like. In this case, the release agent, the colorant, and the like may be mixed after separately preliminarily dispersing in advance to prepare the master solution.
[0019]
More specific means of the above (2) include a resin solution in which a polyester resin is dissolved in an organic solvent in advance in a mixing / dispersing machine using a medium such as a ball mill, a bead mill, a sand mill, or a continuous bead mill. Resin in which mold release agent and colorant are finely dispersed in organic solvent by adding mold agent and colorant to make master solution by stirring and dispersing, and further diluting polyester resin and additional organic solvent There are methods for producing solutions. The production method (2) as described above is preferable to the method (1) in which the polymer component (gel component) of the polyester resin is not cut and is dispersed by melt-kneading.
[0020]
Examples of the organic solvent for dissolving or dispersing the polyester resin include hydrocarbons such as pentane, hexane, heptane, benzene, toluene, xylene, cyclohexane, petroleum ether; methylene chloride, chloroform, dichloroethane, dichloroethylene, trichloroethane, trichloroethylene, Halogenated hydrocarbons such as carbon tetrachloride; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; esters such as ethyl acetate and butyl acetate are used. These solvents can be used in combination of two or more, but from the viewpoint of solvent recovery, it is preferable to use the same type of solvent alone. The organic solvent dissolves or disperses the polyester resin, preferably has a low boiling point and has a relatively low toxicity and is easy to remove the solvent in a subsequent process. As such a solvent, methyl ethyl ketone is most preferable.
[0021]
Next, the mixture containing the polyester resin and the organic solvent is emulsified in an aqueous medium. In this case, the resin solution prepared by the above method is emulsified by mixing with an aqueous medium in the presence of a basic neutralizing agent. In this step, a method of gradually adding an aqueous medium (water or a liquid medium containing water as a main component) to a resin solution obtained by neutralizing a carboxyl group of a polyester resin with a base is preferable. In that case, by adding water gradually to the organic continuous phase of the mixture, a water-in-oil discontinuous phase is formed, and by adding additional water, the oil-in-water discontinuous phase is added. To form a suspension / emulsion in which the mixture is suspended as particles (droplets) in an aqueous medium (hereinafter, this method is referred to as phase inversion emulsification).
[0022]
In phase inversion emulsification, water is added so that the ratio of water to the total amount of the organic solvent and added water is 30 to 80% by mass. More preferably, it is 35-70 mass%, and it is especially preferable that it is 40-70 mass%. The aqueous medium used is preferably water, more preferably deionized water.
[0023]
The polyester resin used in the present invention is a polyester resin having a carboxyl group, and becomes a self-dispersible polyester resin by neutralizing the carboxyl group. The acid value of the self-water dispersible polyester resin used in the present invention is preferably 1 to 30 KOHmg / g, more preferably 3 to 20 KOHmg / g. If the resin acid value is less than 1, phase inversion emulsification does not proceed smoothly and coarse particles are generated, which is not preferable. On the other hand, an acid value higher than 30 is not preferable because the charge amount under various environments is not stable. The resin having self-water dispersibility becomes an anionic type by neutralizing a carboxyl group with a basic compound. As a result, the hydrophilicity of the resin is increased, and the resin can be stably dispersed in the aqueous medium without using a dispersion stabilizer or a surfactant. Moreover, there is no restriction | limiting in particular as a basic compound for neutralization, For example, inorganic bases, such as sodium hydroxide, potassium hydroxide, ammonia, and organic bases, such as diethylamine, a triethylamine, and isopropylamine, are used. Of these, inorganic bases such as ammonia, sodium hydroxide, and potassium hydroxide are preferred. In order to disperse the polyester resin in the aqueous medium, there is a method of adding a dispersion stabilizer such as a suspension stabilizer or a surfactant. However, the suspension stabilizer or the surfactant is added and emulsified. The method requires high shear forces. As a result, the generation of coarse particles and the particle size distribution become broad, which is not preferable. Further, in the case of a highly viscous resin containing a gel content, the particle size distribution becomes more non-uniform, and there is a practical limit. Therefore, in the present invention, a self-water dispersible resin is used, and the carboxyl group of the resin is neutralized with a basic compound.
[0024]
As a method for neutralizing the carboxyl group of the polyester resin with a base, for example, (1) a mixture containing a polyester resin having a carboxyl group, an organic pigment, a release agent and an organic solvent is prepared, and then neutralized with a base. And (2) a method in which a basic neutralizing agent is mixed in advance in an aqueous medium, and the acidic group of the polyester resin contained in the mixture is neutralized when phase-inverted and emulsified.
[0025]
The usage-amount of a basic compound is an amount equivalent to 1 to 3 times the amount required in order to neutralize all the carboxyl groups of a polyester resin. Moreover, it is more preferable that it is the quantity equivalent to 1 to 2 times. Thus, by adding in excess of the amount required to neutralize the carboxyl group of the polyester resin, it is possible to prevent the formation of irregularly shaped particles, improve the sphericity of the toner, The particle size distribution can be sharpened.
[0026]
In phase inversion emulsification, homomixer (Special Machine Industries Co., Ltd.), or Thrasher (Mitsui Mining Co., Ltd.), Cavitron (Eurotech Co., Ltd.), Microfluidizer (Mizuho Industry Co., Ltd.), Menton Gorin homogenizer (Gorin Inc.) ), Nanomizer (Nanomizer Co., Ltd.), Static Mixer (Noritake Company), etc., high share emulsifying disperser, continuous emulsifying disperser and the like can be used.
[0027]
However, rather than using the above-described disperser with a high share, for example, a stirring device, an anchor blade, a turbine blade, a fiddler blade, a full zone blade, a max blend blade, a meniscal blade as disclosed in JP-A-9-114135 Etc. are preferably used. Among these, a large wing excellent in uniform mixing properties such as a Max blend wing and a full zone wing is more preferable. The peripheral speed of the stirring blade in the emulsification step (phase inversion emulsification step) for forming fine particles of the mixture in the aqueous medium is preferably 0.2 to 10 m / s, and is low as less than 0.2 to 8 m / s. A method of dropping water while stirring with a shear is more preferable. Most preferably, it is 0.2-6 m / s. When the peripheral speed of the stirring blade is faster than 10 m / s, the dispersion diameter at the time of phase inversion emulsification becomes large, which is not preferable. On the other hand, when the peripheral speed is lower than 0.2 m / s, the stirring is not uniform, phase inversion does not occur uniformly, and coarse particles tend to be generated, which is not preferable. Moreover, the temperature at the time of phase inversion emulsification is not particularly limited, but the higher the temperature, the more coarse particles are generated, which is not preferable. On the other hand, when the temperature is too low, the viscosity of the mixture containing the polyester resin and the organic solvent is increased, and the generation of coarse particles is increased. The temperature range during phase inversion emulsification is preferably 10 to 40 ° C. More preferably, it is the range of 15-30 degreeC.
[0028]
The peak volume particle size of the fine particles of the resin solution produced in the first step is more than 1 μm and not more than 5 μm, more preferably more than 1 μm and 3 μm. When it is 1 μm or less, when an organic pigment or a release agent is used, it is not preferable because it is not sufficiently encapsulated by the polyester resin, which adversely affects charging characteristics and development characteristics. If the particle size is large, the particle size of the toner to be obtained is limited. Therefore, it is necessary to make the particle size smaller than the particle size of the target toner, but if it is larger than 5 μm, coarse particles are likely to be generated. Therefore, it is not preferable. The particle size distribution of the fine particles of the colored resin solution produced in the first step is such that the volume particle size ratio of 10 μm or more is 1% or less, more preferably 0.5% or less, and the volume particle size ratio of 5 μm or more. Is 3% or less, more preferably 1% or less.
[0029]
In the second step, the fine particles of the resin solution obtained in the first step are united to form a unity of the microparticles, thereby forming toner particles having a desired particle size.
[0030]
In the coalescence method, the dispersion of fine particles obtained in the first step is diluted with water to adjust the amount of solvent. Thereafter, a dispersion stabilizer is added and coalescence is advanced by dropping an aqueous electrolyte solution in the presence of the dispersion stabilizer to obtain an aggregate having a predetermined particle diameter.
[0031]
The fine particles obtained in the first step are stably dispersed in the aqueous medium by the action of the electric double layer by the carboxylate. In the second step, the particles are destabilized by adding an electrolyte that destroys or reduces the electric double layer to the aqueous medium in which the fine particles are dispersed. Examples of the electrolyte that can be used in the present invention include acidic substances such as hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, and oxalic acid. In addition, organic and inorganic water-soluble salts such as sodium sulfate, ammonium sulfate, potassium sulfate, magnesium sulfate, sodium phosphate, sodium dihydrogen phosphate, sodium chloride, potassium chloride, ammonium chloride, calcium chloride, sodium acetate, etc. It can be used effectively as an electrolyte. These electrolytes may be used alone or in combination of two or more substances. Among them, monovalent cation sulfates such as sodium sulfate and ammonium sulfate are preferable for promoting uniform coalescence. In the production method of the present invention, the fine particles obtained in the first step are swollen by a solvent, and the electric double layer of the particles is shrunk and unstable due to the addition of an electrolyte. The coalescence easily proceeds even when the particles collide with each other by the stirring of the shear force.
[0032]
By the way, only by adding an electrolyte or the like, the dispersion stability of the fine particles in the system becomes unstable, so the coalescence becomes non-uniform and coarse particles and aggregates are generated. In order to prevent agglomerates of fine particles produced by electrolytes or acidic substances from repeating reunion and forming aggregates larger than the target particle size, before adding electrolytes etc., hydroxyapatite It is necessary to add an inorganic dispersion stabilizer such as ionic or nonionic surfactant as a dispersion stabilizer. The dispersion stabilizer to be used is required to have a property capable of maintaining dispersion stability even in the presence of an electrolyte added later. Examples of the dispersion stabilizer having such characteristics include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester. , Polyoxyethylene sorbitan fatty acid esters and the like, or various nonionic emulsifiers such as pluronics, alkyl sulfate ester type anionic emulsifiers, and quaternary ammonium salt type cationic dispersion stabilizers. Among these, even if an anion type or nonionic type dispersion stabilizer is added in a small amount, the dispersion stability of the system is effective, which is preferable. The cloud point of the nonionic surfactant is preferably 40 ° C. or higher. The surfactants described above may be used alone or in combination of two or more. In the production method of the present invention, by adding an electrolyte in the presence of a dispersion stabilizer (emulsifier), it becomes possible to prevent non-uniform coalescence, and as a result, a sharp particle size distribution is obtained. An improvement in yield is achieved.
[0033]
Further, in order to promote uniform coalescence, the temporary stirring conditions are important. The kind of stirring blade and the stirring conditions that can be preferably used in the present invention are the same as described above. Under the above conditions, coalescence proceeds only by collision of fine particles, and the coalescence does not dissociate and disperse again. In particular, in the coalescence method, coalescence proceeds preferentially from fine particles, so that generation of ultrafine particles is small and a sharp particle size distribution is achieved, so that an improvement in yield can be achieved.
[0034]
In the case of producing a unity, it is preferable to further dilute the fine particle dispersion obtained by phase inversion emulsification in the first step with water. Thereafter, a dispersion stabilizer and an electrolyte are sequentially added to perform coalescence. Alternatively, it is preferable to adjust the amount of the solvent in the dispersion by adding an aqueous solution of a dispersion stabilizer and / or an electrolyte to obtain particles having a predetermined particle diameter. The amount of the solvent contained in the system before adding the electrolyte is preferably in the range of 15 to 45% by mass. Moreover, the inside of the range of 18-30 mass% is more preferable, and especially the inside of the range of 20-25 mass% is preferable. When the amount of the solvent is less than 15% by mass, the electrolytic mass required for coalescence is increased, which is not preferable. On the other hand, if the amount of the solvent is more than 45% by mass, the generation of aggregates due to non-uniform coalescence increases, and the amount of dispersion stabilizer added increases, which is not preferable.
[0035]
The amount of the dispersion stabilizer used is preferably in the range of 0.1 to 3.0% by mass with respect to the solid content of the fine particles, for example. The inside of the range of 0.3-2.0 mass% is more preferable, and the inside of the range of 0.3-1.5 mass% is especially preferable. If the amount is less than 0.1% by mass, the desired effect of preventing the generation of coarse particles cannot be obtained. On the other hand, if the amount is more than 3.0% by mass, coalescence does not proceed sufficiently even if the amount of the electrolyte is increased, and particles having a predetermined particle diameter cannot be obtained. As a result, fine particles remain and yield. Is not preferable.
[0036]
Moreover, it is preferable that the quantity of the electrolyte to be used exists in the range of 0.5-15 mass% with respect to solid content content of microparticles | fine-particles. It is more preferably within a range of 1 to 12% by mass, and particularly preferably within a range of 1 to 10% by mass. When the amount of the electrolyte is less than 0.5% by mass, the coalescence does not proceed sufficiently, which is not preferable. On the other hand, when the amount of the electrolyte is more than 15% by mass, the coalescence becomes non-uniform, which is not preferable because aggregates and coarse particles are generated and the yield is lowered.
[0037]
The temporary temperature is preferably in the range of 10 to 50 ° C. More preferably, it exists in the range of 20-40 degreeC, and it is especially preferable that it is 20-35 degreeC. When the temperature is lower than 10 ° C., it is difficult to perform coalescence, which is not preferable. On the other hand, when the temperature is higher than 50 ° C., the coalescence speed is increased, and aggregates and coarse particles are easily generated, which is not preferable. In the production method of the present invention, it is possible to produce a unity by unity under a low temperature condition such as 20 to 40 ° C.
[0038]
By the way, in order to maintain the frictional charging performance satisfactorily, it is effective to prevent the colorant and the like from being exposed on the surface of the toner particles, that is, to have a toner structure in which the colorant and the like are included in the toner particles. The deterioration of the chargeability accompanying the reduction in the toner particle size is caused by the fact that a part of the contained colorant and other additives (usually a release agent) is exposed on the toner particle surface. That is, even when the content (% by mass) of the colorant and the like is the same, the surface area of the toner particles increases due to the reduction in the particle size, and the ratio of the colorant and the release agent exposed on the toner particle surface increases. As a result, the composition of the toner particle surface changes greatly, and the frictional charging performance of the toner particles changes greatly, making it difficult to obtain an appropriate chargeability.
[0039]
The toner particles produced according to the present invention are characterized in that a colorant, a release agent and the like are encapsulated in a polyester resin. Whether the colorant, the release agent or the like is not exposed on the toner particle surface can be easily determined by observing the cross section of the particle with a TEM (transmission electron microscope), for example. More specifically, a cross section obtained by embedding the toner particles with a resin and cutting with a microtome is dyed with ruthenium oxide or the like if necessary, and when observed with a TEM, a colorant or a release agent is included in the particles. It can be confirmed that the particles are dispersed almost uniformly.
[0040]
The unitary shape obtained in the second step can be changed from an indeterminate shape to a spherical shape depending on the degree of unity. For example, it can be changed from 0.94 to 0.99 in terms of average circularity. However, since the present invention proposes a method for producing a toner having a higher sphericity, the production method of the present invention has a higher sphericity in order to exhibit such characteristics. It is preferably used as a method for producing a toner. The average circularity can also be obtained by taking a SEM (scanning electron microscope) photograph of the finally obtained toner particles, measuring and calculating it, and the like, manufactured by Toa Medical Electronics Co., Ltd. Since it can be easily obtained by using the flow type particle image analyzer FPIP-1000, in the present invention, the value measured by this apparatus is used as the average circularity.
[0041]
The toner particles preferably have an average circularity of 0.96 or more. More preferably, a substantially spherical or spherical shape of 0.97 or more improves powder fluidity and transfer efficiency, and when used as a toner, the above range is preferable. In particular, as the particle size decreases, the difference in terms of powder flowability, transfer efficiency, and toner consumption increases between spherical and irregular shapes.
[0042]
After coalescing the fine particles of the colored resin solution, the solvent is removed. The method for removing the solvent is not limited at all, and it is carried out under normal pressure or reduced pressure. In order to remove the solvent quickly under a low temperature condition, it is preferably carried out under reduced pressure.
[0043]
In the third step, the unity obtained in the second step is separated from the aqueous medium and dried. Separation from the aqueous medium can be performed by a known and commonly used means such as a centrifugal separator, a filter press, a belt filter or the like. Subsequently, the toner particles can be obtained by drying the particles. Toner particles produced using an emulsifier or a dispersion stabilizer are preferably washed more thoroughly.
[0044]
As the drying method, any known and commonly used method can be employed. For example, a method in which the toner particles are dried at normal or reduced pressure at a temperature at which the toner particles are not thermally fused or agglomerated, a method of freeze-drying, and the like. It is done. Another example is a method of simultaneously separating and drying toner particles from an aqueous medium using a spray dryer or the like. In particular, a method in which powder is stirred and dried under reduced pressure while heating at a temperature at which toner particles are not thermally fused or agglomerated, or a flash jet drier that instantly dries using a heated and dried air stream (Seishin Corporation) Etc.) is efficient and preferable.
[0045]
Regarding the particle size distribution of the toner obtained by the production method of the present invention, 50% volume particle size / 50% number particle size is 1.25 or less as measured by Multisizer TAII type (aperture tube diameter: 100 μm) manufactured by Coulter. It is preferable that there is, and more preferably 1.20 or less. It is preferable that it is 1.25 or less because good images can be easily obtained. Moreover, GSD is preferably 1.30 or less, and more preferably 1.25 or less. The GSD is a value obtained from the square root of (16% volume particle size / 84% volume particle size) as measured by a multisizer TAII type manufactured by Coulter. The smaller the GSD value, the sharper the particle size distribution and the better the image.
[0046]
The toner obtained by the production method of the present invention preferably has a volume average particle size in the range of 1 to 13 μm from the viewpoint of image quality to be obtained, and about 3 to 10 μm is matched with the current machine. It is more preferable because it is easy to obtain. For a color toner, a range in which the volume average particle diameter is 3 to 8 μm is preferable. When the volume average particle size is reduced, not only the resolution and gradation are improved, but also the effect that the thickness of the toner layer for forming the printed image is reduced and the toner consumption per page is reduced is preferable.
[0047]
The binder resin used in the present invention is a polyester resin, and can be obtained by reacting a compound selected from the following raw materials.
[0048]
The polyester resin used in the present invention is
1) Polybasic acids containing 30 mol% or more of isophthalic acid or a lower alkyl ester thereof based on the total acid component, and
2) aliphatic polyhydric alcohol,
It is a polyester resin obtained by reacting.
[0049]
As the acid component used in producing the polyester resin used in the present invention, the following polybasic acids can be used in addition to isophthalic acid or its lower alkyl ester. For example, divalent polybasic acid compounds include phthalic anhydride, terephthalic acid, orthophthalic acid, adipic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, hexahydrophthalic anhydride, tetrahydrophthalic anhydride Dicarboxylic acid such as cyclohexanedicarboxylic acid, succinic acid, malonic acid, glutaric acid, azelaic acid, sebacic acid, or a derivative thereof or an esterified product thereof, for example, as a crosslinking agent for obtaining a crosslinked resin, trimellitic acid, anhydrous Examples thereof include tri- or higher functional polycarboxylic acids such as trimellitic acid, pyromellitic acid, pyromellitic anhydride, derivatives thereof, and esterified products thereof.
[0050]
Moreover, the following aliphatic polyhydric alcohol can be used as an alcohol component used when manufacturing the polyester resin used by this invention. Examples of the divalent aliphatic alcohol include 1,4-cyclohexanedimethanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, neopentyl glycol, butanediol, pentanediol, and hexanediol. Diols such as polyethylene glycol, polypropylene glycol, ethylene oxide-propylene oxide random copolymer diol, ethylene oxide-propylene oxide block copolymer diol, ethylene oxide-tetrahydrofuran copolymer diol, polycaprocactone diol, Further, for example, sorbitol, 1,2,3,6-hexanetetraol as a crosslinking agent for obtaining a crosslinked resin 1,4-sorbitan, pentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylol Trifunctional or higher polyhydric alcohols such as ethane, trimethylolpropane, 1,3,5-trimethylolbenzene and the like can be mentioned.
[0051]
In the present invention, the use of an aliphatic polyhydric alcohol improves the compatibility of the polyester resin with the wax and improves the offset resistance. Moreover, fixing property at low temperature is improved by softening the polyester main chain.
[0052]
When the crosslinked polyester resin is produced, a polyvalent epoxy compound can also be used as a crosslinking agent. Examples of such compounds include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, ethylene glycol diglycidyl ether, hydroquinone diglycidyl ether, N, N-diglycidyl aniline, glycerin triglycidyl ether. , Trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether, pentaerythritol tetraglycidyl ether, tetrakis 1,1,2,2 (p-hydroxyphenyl) ethane tetraglycidyl ether, cresol novolac type epoxy resin, phenol novolac type epoxy Resin, polymer or copolymer of an epoxy group-containing vinyl compound, epoxidized resorcinol-acetone condensate, partial energy Carboxymethyl polybutadiene, polymers of vinyl compounds having an epoxy group, or a copolymer, semi-drying or drying fatty acid ester epoxy compound, and the like.
[0053]
The polyester resin used in the present invention is preferably a crosslinked resin, and particularly preferably a crosslinked resin using a polyvalent epoxy compound as a crosslinking agent. As the epoxy compound used as the crosslinking agent, among the above compounds, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, glycerin triglycidyl ether , Trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether, and pentaerythritol tetraglycidyl ether are more preferably used.
[0054]
Specifically, as an example of bisphenol A type epoxy resin, Dainippon Ink Chemical Industries, Ltd. Epicron 850, Epicron 1050, Epicron 2055, Epicron 3050, etc., are examples of bisphenol F type epoxy resin. Epicron 830, Epicron 520, etc. manufactured by Dainippon Ink & Chemicals, Inc. as examples of orthocresol novolak type epoxy resins are N-660, N-665, N-667, N-670, N-673. N-680, N-690, N-695, and the like, and examples of phenol novolac type epoxy resins include Epicron N-740, N-770, N-775, N-865 and the like manufactured by Dainippon Ink & Chemicals, Inc. Can be mentioned. Examples of the polymer or copolymer of a vinyl compound having an epoxy group include a homopolymer of glycidyl (meth) acrylate, an acrylic copolymer, and a copolymer with styrene.
[0055]
Moreover, the said epoxy compound can also be used in combination of 2 or more types, Furthermore, the mono epoxy compound described below can also be used together as a modifier | denaturant of resin. Examples of the monoepoxy compound that can be used simultaneously include phenyl glycidyl ether, alkylphenyl glycidyl ether, alkyl glycidyl ether, alkyl glycidyl ester, glycidyl ether of alkylphenol alkylene oxide adduct, α-olefin oxide, monoepoxy fatty acid alkyl ester, and the like. It is done.
[0056]
By using these monoepoxy compounds in combination, fixability and resistance to offset at high temperatures are improved. Among these, alkyl glycidyl esters are particularly preferably used. Specific examples include neodecanoic acid glycidyl ester (Cardura E; manufactured by Shell Japan).
[0057]
The polyester resin used in the present invention can be obtained, for example, by performing a dehydration condensation reaction or a transesterification reaction in the presence of a catalyst using the above raw material components. The reaction temperature and reaction time at this time are not particularly limited, but are usually 150 to 300 ° C. and 2 to 24 hours.
[0058]
As a catalyst for performing the above reaction, for example, tetrabutyl titanate, zinc oxide, stannous oxide, dibutyltin oxide, dibutyltin dilaurate, paratoluenesulfonic acid, and the like can be used as appropriate.
[0059]
The glass transition temperature (Tg) of the polyester resin used in the present invention is preferably 50 to 85 ° C., among which the Tg of 55 to 75 ° C. is particularly preferable. When the Tg is lower than 50 ° C., a blocking phenomenon (thermal aggregation) tends to occur when the toner is stored, transported, or exposed to a high temperature inside the developing device of the machine. If it is higher than 85 ° C., the low-temperature fixability is lowered, which is not preferable.
[0060]
Moreover, as a softening point of the polyester resin used for this invention, the thing of the range of 90 degreeC or more, especially 90 degreeC-180 degreeC is preferable, More preferably, it is the range of 95 degreeC-160 degreeC. When the softening point is less than 90 ° C., the toner tends to cause an agglomeration phenomenon, which tends to cause troubles during storage and printing, and when it exceeds 180 ° C., the fixability often deteriorates.
[0061]
The polyester resin used in the present invention is preferably a blend of a plurality of resins having different softening points. By blending a plurality of resins having different softening points, it is possible to obtain a balance between offset resistance in a wide temperature range and good low-temperature fixability as compared with a single resin. The resin having a high softening point is preferably a crosslinked resin, and the softening point is preferably in the range of 150 to 230 ° C, and preferably 160 to 200 ° C. On the other hand, a linear resin is preferable as the low softening point resin, and the softening point is in the range of 80 to 130 ° C, preferably 90 to 120 ° C. The use ratio (mass ratio) of the high softening point resin and the low softening point resin is in the range of 20/80 to 70/30, preferably 30/70 to 60/40.
[0062]
When blending a plurality of resins having different softening points, it is preferable to use a polyester resin crosslinked with a polyvalent epoxy compound as the high softening point resin. Each resin to be blended is preferably a resin produced using polybasic acids containing 30 mol% or more of isophthalic acid or a lower alkyl ester thereof with respect to the total acid component.
[0063]
The softening point of the resin in the present invention is defined by a T1 / 2 temperature measured using a flow tester CFT-500 manufactured by Shimadzu Corporation, which is a constant load extrusion type capillary rheometer. The measurement condition with a flow tester is a piston cross-sectional area of 1 cm. ² The cylinder pressure was 0.98 MPa, the die length was 1 mm, the die hole diameter was 1 mm, the measurement start temperature was 50 ° C., the temperature increase rate was 6 ° C./min, and the sample mass was 1.5 g.
[0064]
In the production method of the present invention, a release agent can be used. In this case, the release agent is selected from the group of hydrocarbon waxes such as polypropylene wax, polyethylene wax and Fiescher-Tropsch wax, and natural ester waxes such as synthetic ester wax, carnauba wax and rice wax. The mold release agent used is used. Of these, natural ester waxes such as carnauba wax and rice wax, synthetic ester waxes obtained from polyhydric alcohols and long-chain monocarboxylic acids, and hydrocarbon waxes such as Fischer-Tropsch wax are preferably used. As the synthetic ester wax, for example, WEP-5 (manufactured by NOF Corporation) is preferably used. If the content of the release agent is less than 1% by mass, the releasability is likely to be insufficient, and if it exceeds 40% by mass, the wax is likely to be exposed on the toner particle surface, and the chargeability and storage stability are reduced. Since it becomes easy, the inside of the range of 1-40 mass% is preferable.
[0065]
In the production method of the present invention, a charge control agent can be used. The positively chargeable charge control agent is not particularly limited, and known and commonly used nigrosine compounds, quaternary ammonium compounds, onium compounds, triphenylmethane compounds, and the like can be used for toner. A basic group-containing compound such as an amino group, an imino group, or an N-heterocycle, such as a tertiary amino group-containing styrene acrylic resin, can also be used in combination with the nigrosine dye as a positively chargeable charge control agent. Depending on the application, a small amount of a negative charge control agent such as an azo dye metal complex or a salicylic acid derivative metal complex salt may be used in combination. Negative charge control agents include trimethylethane dyes, metal complexes of salicylic acid, metal complexes of benzylic acid, copper phthalocyanine, perylene, quinacridone, azo pigments, metal complex azo dyes, azochrome complexes Examples thereof include dyes, calixarene-type phenol condensates, cyclic polysaccharides, resins containing carboxyl groups and / or sulfonyl groups, and the like.
[0066]
The content of the charge control agent is preferably 0.01 to 10% by mass. It is especially preferable that it is 0.1-6 mass%.
[0067]
There is no restriction | limiting in particular about the coloring agent used for the manufacturing method of this invention, A well-known and usual thing is used. For example, black colorants that can be used in the toner of the present invention include carbon blacks such as furnace black, channel black, acetylene black, thermal black, and lamp black classified by the production method, or C.I. I. Pigment Black 11 and other iron oxide pigments, C.I. I. Pigment Black 12 and other iron-titanium complex oxide pigments and blue colorants include phthalocyanine C.I. I. Pigment Blue 1, 2, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 15, 16, 17: 1, 27, 28, 29, 56, 60, 63, and the like. The blue colorant is preferably C.I. I. Pigment Blue 15: 3, 15, 16, 60, and most preferably C.I. I. Pigment Blue 15: 3,60.
[0068]
Examples of yellow colorants include C.I. I. Pigment Yellow 1, 3, 4, 5, 6, 12, 13, 14, 15, 16, 17, 18, 24, 55, 65, 73, 74, 81, 83, 87, 93, 94, 95, 97, 98, 100, 101, 104, 108, 109, 110, 113, 116, 117, 120, 123, 128, 129, 133, 138, 139, 147, 151, 153, 154, 155, 156, 168, 169, 170, 171, 172, 173, 180, 185 and the like. Preferably, C.I. I. Pigment Yellow 17, 74, 93, 97, 110, 155, and 180, and more preferably C.I. I. Pigment Yellow 74, 93, 97, 180, and C.I. I. Pigment Yellow 93, 97, 180 is preferable.
[0069]
Further, examples of red colorants include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 17, 18, 22, 23, 31, 37, 38, 41, 42, 48: 1 48: 2, 48: 3, 48: 4, 49: 1, 49: 2, 50: 1, 52: 1, 52: 2, 53: 1, 54, 57: 1, 58: 4, 60: 1 63: 1, 63: 2, 64: 1, 65, 66, 67, 68, 81, 83, 88, 90, 90: 1, 112, 114, 115, 122, 123, 133, 144, 146, 147, 149,150,151,166,168,170,171,172,174,175,176,177,178,179,185,187,188,189,190,193,194,202,208,209,214, 216, 220, 221, 224, 2 2,243,243: 1,245,246,247, and the like. Preferably, C.I. I. Pigment Red 48: 1, 48: 2, 48: 3, 48: 4, 53: 1, 57: 1, 122 and 209, most preferably C.I. I. Pigment Red 57: 1, 122 and 209.
[0070]
The content of these colorants is preferably 1 to 20% by mass with respect to the whole toner. Especially, it is more preferable that it is 2-18 mass%, and it is especially preferable that it is 2-15 mass%. These colorants can be used alone or in combination of two or more.
[0071]
The dried toner particles can be used as a developer as they are, but it is preferable to add known external additives such as inorganic oxide fine particles and organic polymer fine particles to the toner particle surfaces as external additives for toner. . Hydrophobic silica, inorganic fine particles such as titanium oxide, or organic fine particles are externally added to toner particles to improve physical properties such as fluidity and chargeability when used as a dry developer by electrostatic printing. effective. As the type of external additive, hydrophobic silica treated with various silicone oils is preferably used. Examples thereof include hydrophobic silica treated with dimethyl silicone oil, alkyl-modified silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, fluorine-modified silicone oil, and olefin-modified silicone oil. The external addition method is processed using a known and commonly used model.
[0072]
By mixing a carrier with the toner particles, an electrostatic charge image developer can be obtained. The electrostatic charge image developer comprises a toner produced by the production method of the present invention and a magnetic carrier, preferably a magnetic carrier whose surface is coated with a resin.
[0073]
Iron powder, magnetite, ferrite, etc. used in the usual two-component development system can be used as the carrier core agent (magnetic carrier) used in the electrostatic image developer, but the true specific gravity is low, the resistance is high, and the environment Ferrite or magnetite that is excellent in stability and easy to be spherical and has good fluidity is preferably used. The shape of the core agent can be used without any problem, such as a spherical shape or an indefinite shape. The average particle size is generally 10 to 200 μm, but 30 to 110 μm is preferable for printing a high resolution image.
[0074]
Examples of coating resins for coating these core agents include polyethylene, polypropylene, polystyrene, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether polyvinyl ketone, vinyl chloride / vinyl acetate. Copolymers, styrene / acrylic copolymers, straight silicone resins composed of organosiloxane bonds or modified products thereof, fluorine resins, (meth) acrylic resins, polyesters, polyurethanes, polycarbonates, phenol resins, amino resins, melamine resins, benzoguanamine resins Urea resin, amide resin, epoxy resin and the like can be used.
[0075]
Among these, silicon resin and (meth) acrylic resin are particularly excellent in charging stability and coating strength, and can be used more suitably. Further, the charging characteristics of a developer composed of toner particles and a carrier can be adjusted by adjusting the coating amount of a coating agent such as silicon, adding a charge control agent, or adding a conductive material typified by carbon. That is, the resin-coated carrier used in the present invention is a resin-coated magnetic carrier coated with one or more resins selected from silicon resin and (meth) acrylic resin using ferrite or magnetite as a core agent. It is preferable to adjust the charging characteristics by adding a charge control agent, carbon or the like during coating.
[0076]
Further, the toner produced by the production method of the present invention can be used in a normal non-magnetic one-component developing type printing apparatus, a two-component developing type printing apparatus, a magnetic one-component developing type printing apparatus, or the like. Further, on a flexible printed circuit board having an electrode having a function of adjusting the amount of toner passing through a powder toner that has been frictionally charged using a non-magnetic one-component developing device having a developer carrying roll and a layer regulating member. Therefore, it can be suitably used for a so-called toner jet type printer in which an image is formed by spraying directly on the paper on the back electrode through the hole. The toner produced by the production method of the present invention forms an electrostatic image on the latent image carrier, and develops the obtained electrostatic image using a developer carried on the developer carrier, Printing can be performed by an image forming method in which the toner image formed on the cargo image carrier is transferred onto a transfer material such as paper or film, and the toner image on the transfer material is thermally fixed by a heat roll.
[0077]
【Example】
EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In Examples and Comparative Examples, unless otherwise indicated, “part” means “mass part” and “water” means deionized water. A synthesis example of the binder resin used for preparing the toner first is shown below.
[0078]
(Resin synthesis example 1)
330 parts by weight of terephthalic acid
Epicron N-695 7 parts by mass
Epiklon 720 10 parts by mass
3 parts by weight of Cardura E
21 parts by mass of diethylene glycol
104 parts by weight of neopentyl glycol
50 parts by mass of ethylene glycol
Tetrabutyl titanate 2.5 parts by mass
* Epiclon N-695 (manufactured by Dainippon Ink & Chemicals, Inc.); the number of epoxy groups in one molecule is distributed, the number of epoxy groups in one molecule is 2 or more, and the average is 5 Multifunctional cresol novolac type epoxy resin
Epoxy equivalent 220 (g / eq)
Epicron 720 (manufactured by Dainippon Ink & Chemicals, Inc.); an alcohol ether type epoxy compound with neopentyl glycol as the basic skeleton
Epoxy equivalent 150 (g / eq)
* Cardura E (Shell Japan alkyl glycidyl ester); epoxy equivalent 250 (g / eq)
[0079]
Put the above raw materials in a 2L glass four-necked flask, attach a thermometer, stir bar and nitrogen inlet tube, react in an electric heating mantle heater at 240 ° C for 10 hours under normal pressure nitrogen flow, and then depressurize sequentially. The reaction was continued at 10 mmHg. The reaction was followed by a softening point according to ASTM E28-517, and the reaction was terminated when the softening point reached 163 ° C.
Thereafter, the resins shown in Table 1-1 and Table 1-2 were produced in the same manner.
[0080]
[Table 1]

[0081]
[Table 2]

The display in the table is as follows.
TPA: terephthalic acid
DEG: Diethylene glycol
NPG: Neopentyl glycol
EG: Ethylene glycol
IPA: Isophthalic acid
TMP: Trimethylolpropane
Cardura e: Alkyl glycidyl ester manufactured by Shell Japan (epoxy equivalent: 250)
Epicron n-695: Dai Nippon Ink Chemical Co., Ltd. polyfunctional cresol novolac epoxy resin (epoxy equivalent: 220)
Epicron 720: Alcohol ether type epoxy resin (epoxy equivalent 150) manufactured by Dainippon Ink & Chemicals, Inc.
Epicron 830: Dainippon Ink & Chemicals, Inc. bisphenol f type epoxy resin (epoxy equivalent 170)
[0082]
(Example of preparation of mold release agent dispersion)
Carnauba wax “Carnauba Wax No. 1” (imported by Yoko Kato) 30 parts and 70 parts of a polyester resin (Synthesis Example 9 in Table 1) were kneaded with a pressure kneader, and the kneaded product and 185 parts of methyl ethyl ketone were charged into a ball mill. After stirring for 8 hours, the product was taken out and the solid content was adjusted to 35% by weight to obtain a release agent fine dispersion W1. Similarly, a release agent fine dispersion having the following composition was obtained.
[0083]
[Table 3]
Table 2

[0084]
(Example of preparation of colorant master solution)
A coloring pigment and a polyester resin are added to an organic solvent (methyl ethyl ketone), pre-dispersed with a desper, and then wet-dispersed with a motor mill M-1000 (manufactured by Eiger, USA) to obtain a master solution for each colorant. Adjusted. Tables 3 and 4 show the composition of each colorant master solution, the dispersion conditions, and the solid content of the finally obtained master solution.
[0085]
[Table 4]
Table 3. Colorant master solution recipe 1
(Polyester resin used: Synthesis example 9 in Table 1)

[0086]
[Table 5]
Table 4. Colorant master solution recipe 2
(The colorant is carbon)

The colorants shown in Tables 3 and 4 are as follows.
Carbon: Carbon black "Elftex-8" manufactured by Cabot
Black pigment: Black pigment “ETB-100” manufactured by Titanium Industry Co., Ltd.
Cyan: Cyan pigment “Ket-111” (Pigment Blue 15: 3) manufactured by Dainippon Ink and Chemicals, Inc.
Yellow: Yellow pigment “Cromophtal Yellow 3G” (Pigment Yellow 94) manufactured by Ciba Specialty Chemicals
Magenta: Magenta pigment “Magenta R” (Pigment Red 122) manufactured by Dainippon Ink & Chemicals, Inc.
[0087]
(Preparation example of charge control agent dispersion)
N-04 as a positive charge control agent; Bontron N-04 (produced by Orient Chemical Co., Nigrosine Dye) and methyl ethyl ketone are blended at a weight ratio of 30/70, and dispersed with a motor mill M-1000 (produced by Eiger, USA). The solid content was adjusted to 30% by weight to obtain a charge control agent dispersion E-1.
[0088]
(Preparation of mill base)
The above release agent dispersion, colorant master chip, dilution resin (additional resin), and methyl ethyl ketone are mixed and dissolved for 3 hours with a desper at a solid content of 56% and a temperature condition of 30-40 ° C.・ Dispersed. The obtained mixture was adjusted to a solid content of 55% to make a mill base. Tables 5 and 6 show the formulation of the produced mill base.
[0089]
[Table 6]
Table 5-1. Blend-based mill base recipe

[0090]
[Table 7]
Table 5-2. Blend-based mill base recipe

[0091]
[Table 8]
Table 6. Single resin mill base recipe

[0092]
<Manufacturing toner by the unification method>
(Example)
Three-One Motor was charged with 545.5 parts of Millbase MB5 in a cylindrical 2 L separable flask having a Max Blend blade as a stirring blade, and then 47.4 parts of 1N aqueous ammonia (equivalent to carboxylic acid was 1.2). After sufficiently stirring at 210 rpm, 133 parts of deionized water was added and further stirred to adjust the temperature to 23 ° C. Subsequently, 133 parts of deionized water was added dropwise under the same conditions to prepare a fine particle dispersion by phase inversion emulsification. The peripheral speed of the stirring blade at this time was 0.71 m / s. Next, 280 parts of deionized water was added (amount of deionized water such that the total amount of 1N ammonia water and water was 593 parts) to adjust the amount of solvent.
[0093]
Subsequently, 2.8 parts of Emar 0 (manufactured by Kao Corporation) which is an anionic emulsifier was diluted with 30 parts of water and added. Thereafter, the temperature is adjusted to 25 ° C. and the rotation speed is adjusted to 158 rpm, and an aqueous solution of 5.2% ammonium sulfate is dropped until the particle size grows to 5.5 μm. Thereafter, the particle size is adjusted to 7 μm under the same conditions. Stirring was continued until growth and the coalescence operation was completed. At this time, the amount of ammonium sulfate added was 300 parts. The peripheral speed of the stirring blade was 0.54 m / s. In each of the examples and comparative examples, the aqueous solution concentration and addition amount of ammonium sulfate were appropriately adjusted so that toner base particles of 7 μm were obtained.
[0094]
<Millbase stability evaluation method>
The stability of various mill bases obtained by blending Tables 5-1, 5-2, and 6 was measured one day after the mill base was prepared by measuring the value of the solution viscosity after standing at 25 ° C. with a B-type viscometer. The case where the viscosity of was significantly increased was rated as x, the case where the viscosity increased after one week was indicated as △, and the case where the viscosity change after one week was hardly observed was indicated as ◯. A product in which no change in viscosity was observed after 2 weeks was marked with ◎.
[0095]
<Evaluation method of toner properties>
The obtained slurry was subjected to distilling off the organic solvent under reduced pressure, washed with reslurry three times, and then dried using a freeze dryer to obtain toner mother particles. Next, a sample is prepared by suspending toner base particles in water containing a small amount of a surfactant. Next, the particle size and particle size distribution of the mother particles were measured using a Coulter Counter Multisizer TAII.
[0096]
The average circularity can be obtained by taking a SEM (scanning electron microscope) photograph of the toner particles, and measuring and calculating the photograph. In the present invention, however, the flow type particles manufactured by Toa Medical Electronics Co., Ltd. It calculates | requires with the image analyzer FPIP-1000. The flow-type particle image analyzer FPIP-1000 is an apparatus that captures the size and shape of fine particles such as toner particles, and particle imaging is performed as follows.
[0097]
First, a sample is prepared by suspending toner particles in water containing a small amount of a surfactant. Next, this sample is allowed to flow down into a transparent and flat cell provided in the flow type particle image analyzer FPIP-1000. A light source that emits pulsed light is installed on one side of the cell, and an imaging camera is provided on the opposite side of the cell so as to face the light source. The toner particles in the sample flowing down in the cell of the FPIP-1000 are captured as a still image by a camera facing the light source while holding the cell when irradiated with pulsed light.
[0098]
Based on the image of the toner particle thus captured, the contour of each toner particle is extracted by the image analysis device, and the projected area and peripheral length of the toner particle image (peripheral length of the toner particle projected image) are calculated. The Further, from the calculated projected area of the toner particle image, the circumference of a circle having the same area (the circumference of the circle having the same area as the toner particle projected area) is calculated. The average circularity is obtained by dividing the circumference of the circle having the same area as the toner particle projection area calculated in this way by the circumference of the toner particle projection image.
[0099]
The conditions when measuring with the above apparatus are as follows.
(1) Preparation of toner particle suspension
0.1 g of surfactant (ELCLEAR (manufactured by Chugai Photo Chemical Co., Ltd.)) is added to 20 g of water, 0.04 g of toner as a sample is further added, and the toner particles are suspended in water with an ultrasonic disperser. Make it cloudy.
(2) Measurement conditions
Measurement temperature: 25 ° C
Measuring humidity: 60%
Number of measured toner particles: 5000 ± 2000
[0100]
<Evaluation method of toner transfer efficiency>
For each mother toner obtained in Examples and Comparative Examples, hydrophobic silica was added to 100 parts by weight of the mother toner, and 1 part by weight was externally added with a Henschel mixer. After adjusting the developer composed of 3 parts of the toner, the transfer efficiency was compared. As for the transfer efficiency, a solid image is developed using a commercially available copying machine, and the copying machine is stopped when the solid image on the photoreceptor passes 50% of the transfer portion. Thereafter, the untransferred image and the transferred image on the photosensitive member are completely peeled off with a tape, respectively, the toner amount of the untransferred image and the toner amount after transfer are measured, and the transfer efficiency is calculated from the following equation.
Transfer efficiency (%) = 100−toner amount after transfer / toner amount of untransferred image × 100
As a result, a transfer efficiency of 95% or more was evaluated as “◯”, a transfer efficiency of 90% or more and less than 95% as “Δ”, and a transfer efficiency of less than 90% as “×”.
[0101]
<Method for evaluating toner thermal characteristics>
In Table 9, the toner melt viscosity “T1 / 2 temperature” was measured using a flow tester (CFT-500) manufactured by Shimadzu Corporation as described above, with a nozzle diameter of 1.0 mmΦ × 1.0 mm and a unit area (cm). ² ) Is a value measured at a heating rate of 0.98 MPa and a heating rate of 6 ° C. per minute. Further, “Tg” (° C.) which is a glass transition temperature is a value measured at a rate of temperature increase of 10 ° C. per minute by a second run method using a differential scanning calorimeter (DSC-50) manufactured by Shimadzu Corporation. In addition, the heat-resistant storage stability was determined by putting 10 parts by mass of toner base particles into a 100 cc glass container, sealing the container, and allowing it to stand in an environment of 50 ° C. for 12 hours, and then removing it to determine the presence or absence of agglomeration. The thing with a hard aggregate was set to x, the thing with the aggregate of the grade which can be loosened with a finger was set to (triangle | delta), and the thing without an aggregate was set to (circle).
[0102]
As for the offset width and the fixing start temperature, the developer was adjusted in advance by externally adding hydrophobic silica to the toner base particles of Examples and Comparative Examples, and then mixing with the silicon resin-coated ferrite carrier. Next, an unfixed image sample of A-4 paper size was prepared with a commercially available copying machine remodeling machine, and the printing paper was fixed at a speed of 90 mm / second through a Ricoh Imagio DA-250 heat roll. The offset width is indicated by a temperature range between an upper limit value and a lower limit value at which no offset occurs. The fixing start temperature is that of the heat roll when an adhesive tape is applied to the image after fixing, the ID (image density) after peeling is 90% or more of the original ID, and no occurrence of offset is observed. Indicated by surface temperature.
[0103]
[Table 9]
Table 7-1. Granulation conditions

[0104]
[Table 10]
Table 7-2. Granulation conditions

The stability of the mill base correlates with the content of isophthalic acid in the total acid component of the resin, and if it is less than 30 mol%, the viscosity easily changes, and it can be understood that the particles cannot be stably produced practically. .
[0105]
[Table 11]
Table 8-1. Toner properties

[0106]
[Table 12]
Table 8-2. Toner properties

[0107]
For Example 8, after preparing the fine particles after phase inversion emulsification, an electrolyte having a concentration lower than the normal condition was dropped, and coalescence was advanced until the particle size became 5 μm. Thereafter, the coalescence was further advanced by dropping an electrolyte having a higher concentration to obtain substantially spherical particles having a low average circularity.
The particles having a high average circularity have good transfer efficiency and powder flowability. All of the pulverized toners having a low average circularity are clearly inferior in both transfer efficiency and powder flowability. From the above results, it can be seen that maintaining the particle shape above a certain value is advantageous for development characteristics.
[0108]
[Table 13]
Table 9-1. Thermal property evaluation results

[0109]
[Table 14]
Table 9-2. Thermal property evaluation results

[0110]
Comparative Examples 1, 2, 3, 4, and 5 in which the content of isophthalic acid in the total acid component of the polyester resin is less than 30 mol% are shown in Table 8 as well as instability of mill base stability in Table 7. Thus, a large amount of fine particles and coarse particles are generated, and the particle size distribution becomes broad. At the same time, the generation of agglomerates was observed. As a result, the thermal characteristics shown in Table 9, particularly the offset width and fixing start temperature, were lower than those of the samples of the examples, so that they could not be used stably in practice. is there. On the other hand, each sample of the example is at a good level in both particle size distribution and shape. It can be seen that each sample of the example achieves a balance of thermal characteristics, and in particular, the fixing start temperature is good. Furthermore, it can be seen that the offset width and the fixing start temperature are further improved by blending a cross-linked resin and a linear resin having different melt viscosities.
[0111]
【The invention's effect】
As described above, according to the production method of the present invention, a chemical toner having excellent millbase stability and a sharp particle size distribution can be produced. Further, the electrostatic image developing toner obtained by this production method has a spherical and sharp particle size distribution, and can achieve offset resistance and low-temperature fixability in a wide temperature range.

Claims (3)

(I) a step of producing a resin solution by dissolving or dispersing a polyester resin having a carboxyl group in an organic solvent, and (ii) mixing the resin solution with an aqueous medium in the presence of a basic compound, thereby A step of producing a suspension in which fine particles of the resin solution are suspended in a medium, (iii) a step of adding an emulsifier and then adding an electrolyte, thereby forming a unity of the fine particles, (iv) A step of removing the organic solvent in the unity, and (v) a method for producing a toner for developing an electrostatic charge image in which the united unit is separated from the aqueous medium and dried.
1) polybasic acids containing 30 mol% or more of isophthalic acid or a lower alkyl ester thereof based on the total acid component, and 2) an aliphatic polyhydric alcohol,
A method for producing a toner for developing an electrostatic charge image, which comprises using a polyester resin obtained by reacting the above. The polyester resin is
1) polybasic acids containing 30 to 60 mol% of isophthalic acid or a lower alkyl ester thereof based on the total acid component, and 2) an aliphatic polyhydric alcohol,
The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the toner is a polyester resin obtained by reacting. (I) a step of producing a resin solution by dissolving or dispersing a polyester resin having a carboxyl group in an organic solvent, and (ii) mixing the resin solution with an aqueous medium in the presence of a basic compound, thereby A step of producing a suspension in which fine particles of the resin solution are suspended in a medium, (iii) a step of adding an emulsifier and then adding an electrolyte, thereby forming a unity of the fine particles, (iv) (V) a toner for developing an electrostatic charge image produced by sequentially performing a step of removing the organic solvent in the unity, and (v) separating the united unit from the aqueous medium and drying. ,
1) polybasic acids containing 30 mol% or more of isophthalic acid or a lower alkyl ester thereof based on the total acid component, and 2) an aliphatic polyhydric alcohol,
A toner for developing an electrostatic charge image, which is a polyester resin obtained by reacting the above.