JP2004126268A - Toner composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner composition which exhibits satisfactory fixation separability and anti-offsetting property even in an oilless fixing system and is excellent in image quality, cleanability, transferability and hot storage resistance. <P>SOLUTION: The toner composition consists essentially of a binder resin, two waxes incompatible with the binder resin and a colorant, and in the number-particle size distribution of dispersion particle diameter of each wax, the standard deviation is ≥0.4 and <2.0, the top peak is present between 1.0 and 1.5 μm, the number proportion of wax particles of ≥1.0 and <1.5 μm is ≥20 and <40%, and the number proportion of wax particles of ≥2.5 μm is <20%. <P>COPYRIGHT: (C)2004,JPO

Description

【００７０】
表中、ワックスの添加量はポリエステル樹脂およびビニル系樹脂の全モノマー使用量とワックス使用量との和に対するワックス使用量の割合を示す。
略号は以下の通りである。
ＢＰＡ−ＰＯ：　ビスフェノールＡプロピレンオキサイド付加物、
ＢＰＡ−ＥＯ：　ビスフェノールＡエチレンオキサイド付加物、
ＴＰＡ：テレフタル酸、
ＴＭＡ：トリメリット酸、
ＤＳＡ：コハク酸誘導体、
Ｓｔ：スチレン、
ＢＡ：ブチルアクリレート
【００７１】
【表２】

【００７２】
実施例中、使用したワックスを以下に示す。
【表３】

【００７３】
顔料マスターバッチの製造
以下フルカラートナーの製造に使用する顔料は、それぞれ、実施例で使用するバインダー樹脂とＣ．Ｉ．Ｐｉｇｍｅｎｔ　Ｒｅｄ　５７−１とを重量比で７：３の割合で加圧ニーダーに仕込み、１２０℃で１時間混練した。冷却後、ハンマーミルで粗粉砕し、顔料含有率３０重量％の顔料マスターバッチを得た。
【００７４】
トナーの製造例
（実施例１）
バインダー樹脂として表４に示すように樹脂１および樹脂４を６５：３５の重量比で用いた。バインダー１００重量部（内添ワックスの重量を含む）に対して、Ｃ．Ｉ．Ｐｉｇｍｅｎｔ　Ｒｅｄ　５７−１（富士色素社製）４．０重量部含有相当のマスターバッチと、１．０重量部の酸化型低分子量ポリプロピレン（１００ＴＳ：三洋化成社製）をヘンシェルミキサーで十分混合した後、２軸押し出し混練機（ＰＣＭ−６３：池貝鉄工社製）を使用して溶融混練した。混練条件は練り部比２５％、シリンダ温度１２０℃、スクリュー回転２００ｒｐｍであった。得られた混練物を冷却プレスで２ｍｍ厚に圧延し、冷却ベルトで冷却した後、フェザーミルで粗粉砕した。その後、機械式粉砕機（ＫＴＭ：川崎重工業社製）で平均粒径１０〜１２μｍまで粉砕し、さらに、ジェット粉砕機（ＩＤＳ：日本ニューマチック工業社製）で粗粉分級しながら平均粒径６．８μｍまで粉砕した後、微粉分級をロータ型分級機（ティープレックス型分級機タイプ：１００ＡＴＰ：ホソカワミクロン杜製）を使用して行い、体積平均粒径７．５μｍのマゼンタトナー粒子を得た。
【００７５】
このトナー粒子１００重量部に対して、疎水性シリカ（ＴＳ−５００：キャボジル社製）１．０重量部と、疎水性シリカ（ＡＥＲＯＳＩＬ　９０Ｇ；日本アエロジル社製）のヘキサメチレンジシラザン処理品；ＢＥＴ比表面積６５ｍ^２／ｇ、ｐＨ６．０、疎水化度６５％以上）１．０重量部を添加し、ヘンシェルミキサーで（周速４０ｍ／ｓｅｃ、６０秒間）混合処理した後、図２に示す装置により、以下の条件で熱による表面改質を行い、マゼンタトナー粒子を得た。更にこのトナー粒子１００重量部にＢＥＴ比表面積２２５ｍ^２／ｇの疎水性シリカ微粒子（ＴＳ−５００；キャボジル社製）０．５重量部及びＢＥＴ比表面積９ｍ^２／ｇのチタン酸ストロンチウム微粒子０．５重量部を加えてヘンシェルミキサーにて周速４０ｍ／ｓにて３分間混合した後、目開き１０６μｍの篩で篩ってトナーを得た。
【００７６】
（表面改質処理の条件）
現像剤供給部；テーブルフィーダー＋振動フィーダー
分散ノズル；４本（全周に対して、各９０度の対称形配置）
噴出角度；３０度
熱風風量；８００Ｌ／ｍｉｎ
分散風量；５５Ｌ／ｍｉｎ
吸引風量；−１２００Ｌ／ｍｉｎ
分散濃度；１００ｇ／ｍ^３
処理温度；１８０℃
滞留時間；０．５秒
冷却風温度；１５℃
冷却水温度；１０℃
【００７７】
（実施例２〜１１及び比較例１〜４並びに参考例）
バインダー樹脂を構成する樹脂の種類および混合比率、外添ワックスの種類および添加量、ならびに混練・冷却条件を表４に示すように変更したこと以外、実施例１と同様にしてトナーを得た。
【００７８】
【表４】

【００７９】
表中、内添ワックスの量はバインダー樹脂１００重量部（内添ワックス重量を含む）中に含有されている内添ワックスの量である。
混合樹脂のＴｍは内添ワックスを含有するバインダー樹脂のＴｍである。
外添ワックスの量はバインダー樹脂１００重量部（内添ワックス重量を含む）に対する値である。
【００８０】
評価
（耐熱性）
トナー２０ｇをガラス瓶に入れ、５５℃の高温下に２４時間放置後、そのトナーを目視で確認することにより行なった。
○：凝集トナーがなく、全く問題なし；
△：軽い軟凝集が存在するが、軽い力ですぐ解れ、実用上問題ないもの；
×：強い凝集塊が存在し、容易には解れないもので実用上問題あり。
【００８１】
（定着分離テスト）
非磁性一成分現像方式のフルカラープリンタＬＰ−３０００Ｃ（エプソン社製）を用いて、テストパターンＡ４縦通紙で先端５ｍｍに幅３６ｍｍのべた帯画像（付着量５ｇ／ｍ^２）を印字した未定着画像を作成した。この未定着画像を以下の定着装置を用いて様々な定着温度で定着させ、分離可能／非オフセット温度域を求めた。当該温度域は、加熱ローラからの紙の分離が良好に行われ、かつオフセット現象が発生しない定着温度範囲をいう。使用ペーパー及び通紙方向は、分離性に不利な６４ｇ／ｍ^２紙のＹ目の縦通紙で行った。定着装置周速は１２０ｍｍ／ｓｅｃであった。
【００８２】
定着装置は図４に示す装置であって、フッ素系表層剤構成のソフトローラタイプのものである。詳しくは、加熱ローラ１１は、外径４０ｍｍで、アルミ芯金１７上にシリコーンゴムからなる厚さ１．５ｍｍの弾性体層１８及びＰＦＡ（四フッ化エチレン−パーフルオロアルキルビニルエーテル共重合体）表層１９を有しており、アルミ芯金内部にヒーター２０を備えている。加圧ローラ１２は、外径３５ｍｍで、アルミ芯金２１上にシリコーンゴムからなる厚さ３ｍｍの弾性体層２２及びＰＦＡ表層２３を有している。加熱ローラ１１と加圧ローラ１２の圧設部には、加熱ローラ側に凸形状となるニップ（ニップ幅７ｍｍ）２４が形成されている。図４の装置は更に定着後のシートを加熱ローラ１１から分離するための分離爪１３、加熱ローラ１１表面をクリーニングするためのクリーニングウェブ１４、クリーニングウェブが巻回されたウェブローラ１５、クリーニングウェブを巻き取る巻き取りローラ１６を備えた構成としたが、定着オイルは使用せずに実験を行った。
【００８３】
○：分離可能／非オフセット温度域が５０℃以上であった；
△：分離可能／非オフセット温度域が３０℃以上５０℃未満であった；
×：分離可能／非オフセット温度域が３０℃未満であった。
【００８４】
（画像光沢度）
光沢度の測定には、光沢度計（ＧＭ−０６０；ミノルタ社製）を用いた。フルカラープリンタＬＰ−３０００Ｃ（エプソン社製）を用いて、１．５ｃｍ×１．５ｃｍのベタ画像（付着量２．０ｍｇ／ｃｍ^２）を印字した未定着画像を作成した。この未定着画像を図４の定着装置を用いて定着温度を１６０℃で定着し、それぞれの画像の光沢度を測定した。
光沢度が、３０以上のものを○、２０以上３０未満のものを△（実用上問題ない）、２０未満のものを×（実用上問題あり）とした。
【００８５】
（高温オフセット性）
フルカラープリンタＬＰ−３０００Ｃ（エプソン社製）を用いて、ハーフトーン画像を印字した未定着画像を作成した。この未定着画像を図４の定着装置を用いて、定着温度を１３０℃〜１９０℃の範囲において５℃刻みで変化させながら未定着画像の定着を行い、画像のオフセットの状態を目視で観察し、高温オフセットが発生する温度を評価した。この高温オフセット発生温度が１６０℃以上のものを○、１５５℃以上１６０℃未満のものを△（実用上問題ない）、１５５℃未満のものを×（実用上問題あり）とした。
【００８６】
（クリーニングＢＳ（ＣＬ−ＢＳ））
フルカラープリンタＬＰ−３０００Ｃ（エプソン社製）を用いて、Ｂ／Ｗ比６％の所定のプリントパターンをＮ／Ｎ環境下（２３℃、４５％）で連続印字した。Ｎ／Ｎ環境下の２０００枚連続印字後（耐久後）に、感光体および中間転写体ベルト上を目視で観察評価した。判断基準は以下の通りである。
○：感光体上および中間転写体上にはフィルミングおよびブラックスポット（ＢＳ）の発生がなく、全く問題なかった；
△：感光体上および中間転写体上、どちらか片方でフィルミングおよびＢＳの発生が見られたが、複写画像上には見えず、実用上問題なかった；
×：感光体上および／または中間転写体上にフイルミングおよびＢＳの発生があり、画像上でも確認でき、実用上問題があった。
【００８７】
（転写中抜け）
クリーニング性の評価方法と同様に連続印字し、Ｎ／Ｎ環境下の２０００枚連続複写後（耐久後）の複写画像を目視により観察し、中抜けを評価した。判断基準は以下の通りである。なお、紙上へのトナー付着量はバイアスの設定を変えて１．０ｍｇ／ｃｍ^２（±０．１）となるように設定している。
○：画像上に中抜けの発生はなかった；
△：画像上に中抜けが発生しているものの、実用上問題なかった；
×：写画像上に中抜けが多数発生しており、実用上問題があった。
【００８８】
（クリーニング規制不良）
クリーニング性の評価方法と同様に連続複写し、Ｎ／Ｎ環境下の２０００枚連続複写後（耐久後）に現像器のスリーブの状態および複写画像を目視により観察し、評価した。判定基準は以下の通りである。
○：スリーブ上にスジ、ムラの発生はなかった；
△：スリーブ上にスジあるいはムラが若干発生しているものの、複写画像上に縦スジがなく、実用上問題なかった；
×：スリーブ上にスジあるいはムラが多数発生しており、異音、トナー固着やトナーこぼれなど実用上問題があった。
【００８９】
（ワックス粒子の個数−粒度分布）
約１０ｍｇのトナーをクロロホルムに溶解して遠心分離し、浮遊してくるワックス粒子を集め、走査型電子顕微鏡写真を用いてイメージアナライザー（ルーゼックス５０００；日本レギュレーター社製）にワックス粒子の写真画像を入力して粒度分布を測定した。なお、各ワックス粒子の粒径は、ワックス粒子が完全球形でない場合、そのワックス粒子の最大直径を測定してワックス粒子の粒径としている。
【００９０】
【表５】

【００９１】
（各種物性評価方法）
＜ガラス転移点（Ｔｇ）測定法＞
示差走査熱量計（ＤＳＣ−２００：セイコー電子社製）を用い、測定する試料１０ｍｇを精密に秤量して、これをアルミニウムパンに入れ、リファレンスとしてアルミナをアルミニウムパンに入れたものを用い、昇温速度３０℃／ｍｉｎで常温から２００℃まで昇温させた後、これを冷却し、昇温速度１０℃／ｍｉｎで２０℃〜１２０℃の間で測定を行い、この昇温過程で３０℃〜９０℃の範囲におけるメイン吸熱ピークのショルダー値をＴｇとした。
【００９２】
＜軟化点（Ｔｍ）測定法＞
フローテスター（ＣＦＴ−５００：島津製作所社製）を用い、測定する試料１．０ｇを秤量し、ｈ１．０ｍｍ×φ１．０ｍｍのダイを使用し、昇温速度３．０℃／ｍｉｎ、予熱時間１８０秒、荷重３Ｏｋｇ、測定温度範囲６０〜１４０℃の条件で測定を行い、上記の試料が１／２流出したときの温度を樹脂軟化点（Ｔｍ）とした。
【００９３】
＜酸価測定方法＞
１０ｍｇの試料をトルエン５０ｍｌに溶解し、０．１％のブロムチモールブルーとフェノールレッドの混合指示薬を用いて、予め標定されたＮ／１０水酸化カリウム／アルコール溶液で滴定し、Ｎ／１０水酸化カリウム／アルコール溶液の消費量から算出した値である。
【００９４】
＜水酸価＞
水酸価は、秤量された試料を無水酢酸で処理し、得られたアセチル化合物を加水分解し、遊離する酢酸を中和するのに必要な水酸価化カリウムｍｇで表した。
＜ＴＨＦ不溶分含有量の測定方法＞
ＴＨＦ不溶分はテトラヒドロフランを溶媒とした１０時間のソックスレー抽出により測定した。
【００９５】
【発明の効果】
本発明のトナーは混練粉砕法で製造しても、オイルレス定着システムに有効に適用され得る。すなわち広い温度領域において良好な定着分離性と耐オフセット性を発揮することができる。本発明のトナーはさらに画質性、クリーニング性、転写性および耐熱保管性にも優れている。
【図面の簡単な説明】
【図１】本発明のトナーを製造するのに適した二軸押し出し混練機および冷却器の概略構成図を示す。
【図２】瞬間的加熱処理を行なうための装置の概略構成図を示す。
【図３】図２の装置における試料噴射室の概略水平断面図を示す。
【図４】本発明のトナーに適した定着装置の概略構成図を示す。
【符号の説明】
１：二軸押し出し混練機、２：冷却器、３：シリンダー、４：モーター、１０１：熱風発生装置、１０２、１０２’、１０２”：導入管、１０３：試料噴射ノズル、１０４：滞留した粉体、１０５：トナー粒子、１０６：熱風噴射ノズル、１０７：噴射室、１０８：冷却風導入部、１０９：サイクロン、１１１：製品タンク、１１２：バグフィルター、１１３：ブロアー、１１４：コニカル部、１１５：フィダー、１１：加熱ローラ、１２：加圧ローラ、１３：分離爪、１４：クリーニングウェブ、１５：ウェブローラ、１６：巻取りローラ、１７：芯金、１８：弾性体層、１９：表層、２０：ヒーター、２１：芯金、２２：弾性体層、２３：表層、２４：ニップ、２５：記録シート、２６：トナー像。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a toner for developing an electrostatic latent image formed by an electrophotographic method, an electrostatic recording method, or the like, and particularly to a toner that does not require oil for a fixing device. The present invention also relates to a pulverized toner composition comprising at least a binder resin and a wax in which the wax is uniformly dispersed to a relatively large diameter.
[0002]
[Prior art]
Conventionally, a heating roll method has been widely used as a fixing method for toner. In the heating roll method, the toner image comes into pressure contact with the surface of the heating roll in a heated and melted state. For this reason, it has been an issue to prevent a phenomenon in which a part of the toner image adheres to and transfers to the surface of the heating roll and causes stain on the next sheet to be fixed, that is, a so-called offset phenomenon. Further, in this heating roll system, a separation mechanism such as a separation claw is provided in the roll portion to prevent a separation failure in which a sheet to be fixed such as paper is wound around the roll after passing through the roll portion. However, in the case where the stress increases due to the speeding up of the copier / printer, or in the case where there is a solid or the like at the leading end of the sheet to be fixed, there arises a problem that poor separation or separation nail scratches occur.
[0003]
For this reason, a method of improving the releasability of the toner during heating and melting by incorporating wax such as polypropylene and polyethylene in the toner, and a method of coating the surface of a heating roll with a resin having excellent separability such as a fluororesin. Has been proposed. However, there is a problem that wax such as polypropylene and polyethylene has poor compatibility with a polyester resin having a relatively strong polarity such as used in toner production. In order to solve such a problem, a technique for improving the compatibility between the polyester resin and the wax and improving the dispersibility of the wax by using a modified wax such as an acid value type polyolefin wax having a polar group at the molecular terminal. Has been proposed. However, with such a technique, although the dispersibility of the wax is improved, since the modified wax has a higher melt viscosity than the unmodified product, the releasability, which is the original function of the wax, is reduced, and the offset phenomenon again occurs. There are problems that arise.
[0004]
The problems with respect to offset resistance and separation property are particularly remarkable in full-color toners. That is, it is necessary for the full-color toner to have higher heat-fusibility at the time of fixing heating and lower viscosity than the black toner, and to obtain gloss, transparency, and color reproducibility. However, a full-color toner using a resin that achieves such required characteristics tends to decrease the intermolecular cohesion at the time of heat melting, so that the toner adherence to the heating roller when passing through the fixing roller increases, resulting in poor separation. Hot offset occurs. In order to prevent such poor separation and high-temperature offset, oil is applied to the fixing roller to reduce the adhesion of toner to the fixing roller. However, there are problems such as an increase in cost due to the installation of the oil application mechanism and an increase in the size of the apparatus.
[0005]
Therefore, attempts have been made to specify the dispersed particle size of the wax particles in the toner. For example, a technique of setting the numerical value of the standard deviation of wax dispersion diameter / average particle diameter × 100 to 20 to 40% (the average diameter is about 0.5 μm) (for example, Patent Document 1), particles having a wax dispersion particle diameter of 1 μm or less (For example, Patent Document 2), and a technique for making 55 to 95% or more particles having a wax dispersed particle diameter of less than 1 μm (for example, Patent Document 3).
[0006]
[Patent Document 1]
JP-A-9-197199
[Patent Document 2]
JP-A-10-161335
[Patent Document 3]
JP-A-8-328293
[0007]
[Problems to be solved by the invention]
However, the above-mentioned technology still failed to achieve sufficient offset resistance and separation properties. Furthermore, even if the amount of wax is slightly increased, the cleaning property is reduced, causing streaks, unevenness, black spots (BS) and filming on the image, and the transfer property is reduced, resulting in a dropout on the image. Or a problem with the image quality. In addition, heat storage stability was lowered, and toner aggregation easily occurred.
[0008]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a toner composition that exhibits sufficient fixing separation properties and offset resistance even in an oilless fixing system.
[0009]
The present invention also provides an electrostatic latent image developing toner composition which exhibits sufficient fixing separation properties and offset resistance even in an oilless fixing system, and is excellent in image quality, cleaning properties, transferability and heat resistant storage properties. The purpose is to provide.
[0010]
[Means for Solving the Problems]
The inventors of the present invention have conducted intensive studies on the toner composition to achieve the above object. As a result, the dispersed particle size distribution of the wax particles contained in the toner was particularly improved in the fixing separation property and the anti-offset property in an oilless fixing system. The inventors have found that the present invention has a close relationship with the properties, and have completed the present invention.
[0011]
That is, the present invention comprises at least a binder resin, two kinds of waxes incompatible with the binder resin, and a colorant, and has a standard deviation of 0.4 to 2. 0, the top peak is between 1.0 and 1.5 μm, the number ratio of wax particles having a size of 1.0 or more and less than 1.5 μm is 20% or more and less than 40%, and a wax having a size of 2.5 μm or more is used. The present invention relates to a toner composition having a particle number ratio of less than 20%.
[0012]
In the present specification, the "toner composition" refers to a toner obtained by melting and kneading toner materials such as a binder resin, a wax and a colorant, and cooling, pulverizing and classifying the kneaded material, as well as the kneaded material after cooling. Shall be used in the concept including. That is, the specific wax particle size distribution described later in the present invention is achieved not only in the toner but also in the kneaded product after cooling.
In addition, the term “toner characteristic” is used to include the fixing separation property, the offset resistance, the cleaning property, the transfer property, the image quality, and the heat-resistant storage property.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
The toner of the present invention comprises at least a binder resin, a wax and a colorant, and the wax is dispersed in the binder resin with a specific particle size distribution. Specifically, the number-particle size distribution of the dispersed particle diameter of the wax in the toner has a standard deviation of 0.4 or more and less than 2.0, preferably 0.60 or more and less than 1.90, and particularly 0.60 or more and less than 1.35. The number ratio of wax particles having a top peak of 1.0 to 1.5 μm, preferably 1.0 to 1.3 μm, particularly 1.0 to 1.1 μm, and 1.0 to less than 1.5 μm. 20% or more and less than 40%, preferably 23% or more and less than 32%, and the number ratio of wax particles having a size of 2.5 μm or more is less than 20%, particularly 1% or more and less than 17%, preferably 3% or more and 9.5%. Is less than.
[0014]
According to the present invention, by setting the dispersed particle size distribution of the wax particles as described above, excellent fixing separation properties and offset resistance can be achieved even in an oilless fixing system. In addition, it is possible to suppress wax particles in the toner surface layer or inside the toner from being exposed or projected on the toner surface. Furthermore, it is possible to prevent the wax particles from separating from the toner when the toner is stirred. For this reason, even if the amount of wax used is appropriately increased, it is possible to suppress the wax contamination on the surface of the member such as the photoreceptor, the intermediate transfer member, and the developing sleeve, and to prolong the durable life of the member, As a result, an image having excellent image quality can be provided for a long period of time.
[0015]
When the particle size is shifted to the larger diameter side from the above particle size distribution, that is, when the top peak exceeds 1.5 μm or the number ratio of wax particles of 2.5 μm or more is 20% or more, the toner is agitated in the developing device. The wax particles having a relatively large diameter are easily separated from the toner, and as a result, the wax dispersion diameter in the toner is reduced and the wax content is reduced. For this reason, it is difficult to secure the fixing separation performance in the oilless fixing system. Further, the offset resistance, the cleaning property, the transfer property, and the heat storage stability are reduced, and the image quality and the gloss of the image are deteriorated. On the other hand, if the particle size distribution is shifted to the smaller diameter side, that is, if the top peak is less than 1.0 μm, the wax cannot sufficiently exude onto the toner surface during melting because the wax dispersion diameter is too small. In addition, it becomes difficult to secure the fixing separation property in the oilless fixing system. Further, when the standard deviation is 2.0 or more or the number ratio of wax particles having a size of 1.0 to less than 1.5 μm is less than 20%, the number ratio of wax particles having a size of 2.5 μm or more becomes too large. As described above, it is difficult to secure the fixing separation performance in the oilless fixing system. Further, the offset resistance, the cleaning property, the transfer property, and the heat storage stability are reduced, and the image quality and the gloss of the image are deteriorated. If the standard deviation is less than 0.4, or if the number ratio of wax particles having a size of 1.0 to less than 1.5 μm is 40% or more, wax exposure on the toner surface increases, and the fluidity decreases. Adversely affect image quality.
[0016]
In the present invention, the number-particle size distribution of the wax particles is determined by dissolving the toner in an organic solvent that dissolves a binder resin such as chloroform and centrifuging the collected wax particles. It was measured from the image. For example, a photographic image of wax particles may be input to an image analyzer (Luzex 5000; manufactured by Nippon Regulator Co., Ltd.) using a scanning electron microscope photograph, and the particle size distribution may be measured. In the present invention, when the wax particles are not perfectly spherical, the maximum diameter of the wax particles is measured to determine the particle diameter of the wax particles.
[0017]
In the number-particle size distribution of the wax particles, each wax particle may be independently composed of only one of the two types of wax, or may be composed of two types of wax.
[0018]
Further, the number average particle diameter in the number-particle size distribution of the wax particle dispersed particle diameter in the toner is preferably 1.2 μm or more and less than 2.5 μm, and more preferably 1.2 μm or more and less than 2.0 μm. The number average dispersed particle size is a number average value of all the wax particles calculated based on the above particle size distribution.
[0019]
The toner of the present invention is usually obtained by melting and kneading toner materials such as a binder resin, a wax and a colorant, and cooling, pulverizing and classifying the kneaded material. Can be controlled by appropriately selecting. For example, when kneading and cooling are performed using a biaxial extruder kneader 1 and a cooling press 2 having a pair of rollers as shown in FIG. 1, the kneading portion ratio (the sum of the kneading portion length M and the transporting portion length T). (The ratio of the length of the kneading portion M to the total length L), the temperature inside the cylinder 3, the number of rotations of the screw by the motor 4, and the press thickness (the gap length between the pair of rollers in the cooling press 2) may be appropriately selected.
[0020]
Specifically, when the kneading portion ratio is reduced, the cylinder temperature is increased, or the screw rotation speed is increased, the standard deviation and the top peak particle size generally increase, and the wax particles having a diameter of 1.0 to less than 1.5 μm are generally used. The number ratio and the number ratio of the wax particles of 2.5 μm or more increase.
If the kneading portion ratio is increased, the cylinder temperature is reduced, the screw rotation speed is reduced, or the press thickness is reduced, the standard deviation and the top peak particle size generally become smaller, and 1.0 to less than 1.5 μm. The number ratio of the wax particles and the number ratio of the wax particles of 2.5 μm or more decrease.
[0021]
The mixing ratio is usually 5 to 45%, and particularly preferably 10 to 35%.
The cylinder temperature is equal to or higher than the softening point (° C.) (hereinafter, referred to as “Bm”) of the binder resin, and particularly equal to or higher than Bm and equal to or lower than Bm + 100 ° C. Specifically, the temperature is usually 90 to 180 ° C, and particularly preferably 100 to 140 ° C. Bm is the softening point of the mixed resin when two or more resins are used as the binder resin, and when the wax is previously added to the binder resin, the softening point of the wax-added binder resin. It is. The screw rotation speed is usually 120 to 270 rpm, and preferably 150 to 250 rpm.
The press thickness is usually 0.5 to 4 mm, and particularly preferably 1 to 3 mm.
[0022]
In the present invention, two kinds of waxes incompatible with a binder resin described later are used as the wax. As such a wax, in the field of toner for developing an electrostatic latent image, a wax that can be used to impart “release and separation properties to a roller of a fixing device” to the toner can be used. Polyolefin waxes such as wax and polypropylene wax, acid-modified waxes such as oxidized polyethylene wax and oxidized polypropylene wax, natural waxes such as carnauba wax and rice wax, montan wax, Fischer-Tropsch wax, paraffin wax, and high molecular weight alcohol Wax and the like.
[0023]
The acid-modified wax can be obtained by subjecting a polyolefin such as polyethylene and polypropylene to an addition reaction with an acid monomer having a carboxyl group and having a polymerizable double bond. As the acid monomer, one or more monomers selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, and maleic anhydride can be used. The acid value of the acid-modified wax is preferably 1 to 60 KOH mg / g, and more preferably 3 to 30 KOH mg / g.
[0024]
The two types of waxes used in the present invention may be waxes of different types. Here, "different types" means that at least one of the material (substance name) and the melting point is different. Preferably, the two waxes used are incompatible with each other.
[0025]
Each of the two types of waxes is preferably a polyolefin-based wax, and it is particularly preferable to use a combination of a polyethylene wax and a polypropylene wax. This is because the toner characteristics are more effectively improved.
[0026]
The two types of waxes preferably have different melting points, and in particular, a combination of a low melting point wax having a melting point of 70 to 90 ° C and a high melting point wax having a melting point of 125 to 145 ° C is preferably used. When two kinds of waxes having different melting points are used, it is particularly preferable to use polyethylene wax as a wax having a relatively low melting point and polypropylene wax as a wax having a relatively high melting point.
[0027]
The melting point of the wax is the temperature of the peak in the DSC curve. In the present invention, the DSC curve used is one measured by a differential scanning calorimeter (DSC-200: manufactured by Seiko Instruments Inc.). However, the DSC curve cannot be measured by the above apparatus, and the DSC curve can be measured. May be measured by any device.
[0028]
The total amount of the two waxes used is 3 to 15 parts by weight, preferably 4 to 10 parts by weight, based on 100 parts by weight of the binder resin. When waxes having different melting points are used as the two kinds of waxes, it is preferable that the amount of the wax having a relatively low melting point be larger than that of the wax having a relatively high melting point. In particular, the amount of the wax having a relatively low melting point is more preferably 2.5 to 10 parts by weight, and the amount of the wax having a relatively high melting point is more preferably 0.5 to 5 parts by weight.
[0029]
The present invention does not preclude the use of three or more "different" waxes. In that case, it is sufficient that the total used amount of all the waxes is within the above range. When three or more types of waxes are used, the particle size distribution may be achieved by all the waxes used, and each wax particle may be composed of only one type of wax. It may consist of more than one type of wax.
[0030]
The two or more waxes used may be added when mixing toner materials such as a binder resin and a colorant, but one of the above “two types of waxes”, preferably a relatively large amount, is used. Is preferably added internally during the synthesis of the binder resin. This is because the wax is preliminarily dispersed in the resin, so that the wax can be highly filled.
[0031]
The binder resin used in the present invention is not particularly limited, and binder resins known in the field of electrostatic latent image developing toner, for example, polyester resins, (meth) acrylic resins, and styrene- (meth) acrylic resins Copolymer resin, epoxy resin, COC (cyclic olefin resin (for example, TOPAS-COC (manufactured by Ticona))) and the like. In the case where a fixing device which does not require oil application at the time of fixing or which fixes by applying a small amount of oil is used, a polyester resin is particularly preferably used.
[0032]
In the present invention, as the polyester resin, a polyester resin obtained by polycondensing a polyhydric alcohol component and a polycarboxylic acid component can be used.
Examples of the dihydric alcohol component among the polyhydric alcohol components include polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene (3,3) -2,2- Bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane Bisphenol A alkylene oxide adducts such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol , 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A, and the like.
Examples of the trihydric or higher alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, and 1,2,4-butanetriol. , 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene and the like Is mentioned.
[0033]
Examples of the divalent carboxylic acid component of the polycarboxylic acid component include, for example, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, and succinic acid. , Adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenylsuccinic acid, isododecenylsuccinic acid, n-dodecylsuccinic acid, isododecylsuccinic acid, n-octenylsuccinic acid, isooctenylsuccinic acid, n-octylsuccinic acid , Isooctyl succinic acid, anhydrides or lower alkyl esters of these acids.
[0034]
Examples of the trivalent or higher carboxylic acid component include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, and 1,2. , 4-Naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4- Examples thereof include cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empoletrimeric acid, anhydrides of these acids, and lower alkyl esters.
[0035]
In the present invention, as the polyester-based resin, a mixture of a raw material monomer for the polyester resin, a raw material monomer for the vinyl-based resin, and a monomer that reacts with the raw material monomers for both resins is used to obtain the polyester resin in the same container. A resin obtained by performing a polycondensation reaction and a radical polymerization reaction for obtaining a vinyl resin in parallel can also be suitably used. The monomers that react with the raw material monomers of both resins are, in other words, monomers that can be used in both the condensation polymerization reaction and the radical polymerization reaction. That is, it is a monomer having a carboxy group capable of undergoing a polycondensation reaction and a vinyl group capable of undergoing a radical polymerization reaction, and examples thereof include fumaric acid, maleic acid, acrylic acid, and methacrylic acid.
[0036]
Examples of the raw material monomer of the polyester resin include the above-mentioned polyhydric alcohol component and polycarboxylic acid component.
Further, as a raw material monomer of the vinyl resin, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert- Styrene or styrene derivatives such as butylstyrene and p-chlorostyrene; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and isobutylene; methyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, and n-butyl methacrylate , Isobutyl methacrylate, t-butyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, neopentyl methacrylate, 3- (methyl) butyl methacrylate, hexyl methacrylate, octyl methacrylate, nonyl methacrylate Alkyl methacrylates such as decyl methacrylate, undecyl methacrylate, dodecyl methacrylate; methyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, acrylic Alkyl acrylates such as n-pentyl acrylate, isopentyl acrylate, neopentyl acrylate, 3- (methyl) butyl acrylate, hexyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate Esters; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid and maleic acid; acrylonitrile, maleic acid ester, itaconic acid ester, vinyl chloride, vinyl acetate, vinyl benzoate, vinyl methyl Examples include ethyl ketone, vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether. Examples of the polymerization initiator for polymerizing the raw material monomer of the vinyl resin include 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1 Azo or diazo polymerization initiators such as' -azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl Examples include peroxide-based polymerization initiators such as peroxycarbonate and lauroyl peroxide.
[0037]
It is desirable that the binder resin has an acid value of 5 to 50 KOH mg / g, preferably 10 to 40 KOH mg / g. In particular, when a polyester resin is used, by using a resin having such an acid value, the dispersibility of carbon black, various colorants, and the like can be improved, and a toner having a sufficient charge amount can be obtained.
[0038]
In the present invention, two types of polyester resins having different softening points, particularly a softening point of 80 to 110 ° C., are used as the polyester resin in order to further improve the fixing separation property and the offset resistance as an oilless fixing toner. It is preferable to use a first polyester resin and a second polyester resin having a softening point of 110 to 160 ° C. More preferably, the softening point of the first polyester resin is 90 to 105 ° C, and the softening point of the second polyester resin is 115 to 150 ° C. Further, from the viewpoint of further improving the heat resistance of the toner, the glass transition point of the first and second polyester-based resins is desirably 50 to 75 ° C, preferably 55 to 70 ° C. When two kinds of resins are used as the binder resin as described above, the acid value of the mixed resin may be within the above range.
[0039]
As the first polyester resin, a polyester resin obtained by polycondensation of the above-mentioned polyhydric alcohol component and polyhydric carboxylic acid component, particularly, a polyhydric alcohol component containing a bisphenol A alkylene oxide adduct as a main component, As the carboxylic acid component, a polyester resin obtained by using at least one selected from the group consisting of terephthalic acid and fumaric acid as a main component is preferable.
[0040]
As the second polyester resin, a polyester resin obtained by polycondensing at least the above-mentioned monomer component containing a trivalent or higher alcohol component and / or a trivalent or higher carboxylic acid component, particularly bisphenol A as a dihydric alcohol component Alkylene oxide adduct is used as a main component, trimellitic acid is used as a trivalent or higher carboxylic acid component, and at least one selected from the group consisting of terephthalic acid, fumaric acid and dodecenyl succinic acid is used as a divalent carboxylic acid component. Is preferred.
[0041]
In addition, as the second polyester resin, a mixture of a raw material monomer of the polyester resin, a raw material monomer of the vinyl resin, and a bi-reactive monomer that reacts with the raw material monomers of both resins is used. It is preferable to use a polyester-based resin obtained by performing a polycondensation reaction for obtaining a vinyl resin and a radical polymerization reaction for obtaining a vinyl-based resin in parallel. Such a resin is preferable from the viewpoint of improving the dispersibility of the wax, the toughness, the fixability, and the offset resistance of the toner. In this case, the content of the vinyl resin in the second polyester resin is preferably 5 to 30% by weight, and more preferably 10 to 25% by weight.
[0042]
It is preferable to include a component insoluble in tetrahydrofuran (THF) in the second polyester resin as described above from the viewpoint of high-temperature offset resistance. From such a viewpoint, it is preferable to use the first and second polyester resins so that the content of the THF-insoluble component in the binder resin is 0.1 to 30% by weight, preferably 0.4 to 10% by weight. preferable.
[0043]
Further, from the viewpoint of further improving the fixing separation property and the offset resistance, the weight ratio of the first polyester resin to the second polyester resin is 65:35 to 30:70 when the obtained toner is used as a full-color toner. The ratio is preferably 60:40 to 35:65, and when used as a monochrome toner, the ratio is preferably 20:80 to 50:50, and more preferably 25:75 to 40:60.
[0044]
In order to internally add one of the two types of wax to the binder resin in advance, when synthesizing the binder resin, one of the two types of wax is added to a monomer for synthesizing the binder resin. What is necessary is just to synthesize a binder resin. In particular, when the first polyester resin (low molecular weight resin) and the second polyester resin (high molecular weight resin) are used together as the binder resin, the second polyester resin is the first polyester resin. It is preferable to add one of the two types of wax during the synthesis of the second polyester-based resin because the wax is harder to disperse than that of the second polyester-based resin. Specifically, a polycondensation reaction (and a radical polymerization reaction, if desired) may be carried out in a state where a wax is added to an acid monomer and an alcohol monomer constituting the polyester resin (and a raw material monomer of a vinyl resin used as desired). good.
[0045]
As the colorant used in the present invention, known pigments and dyes conventionally used as colorants for toners for developing electrostatic latent images can be used. For example, carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, Dupont oil red, quinoline yellow, methylene blue chloride, copper phthalocyanine, malachite green oxalate, lamp black, rose bengal, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 184, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 17, C.I. I. Solvent Yellow 162, C.I. I. Pigment Yellow 180, C.I. I. Pigment Yellow 185, C.I. I. Pigment Blue 15: 1, C.I. I. Pigment Blue 15: 3. The amount of the colorant used is preferably in the range of 2 to 15 parts by weight based on 100 parts by weight of the binder resin (including the weight of the wax added when the wax is previously added to the binder resin).
[0046]
The colorant is preferably used in the form of a master batch obtained by melt-kneading with the binder resin to be used, cooling and pulverizing, from the viewpoint of the dispersibility of the colorant in the toner. When the colorant is used in the form of a masterbatch, the amount of the masterbatch used may be such that the amount of the colorant contained in the masterbatch falls within the above-mentioned range of the used amount of the colorant.
[0047]
The toner of the present invention may contain additives such as a charge control agent and magnetic powder.
As the charge control agent, a known charge control agent conventionally added for controlling the chargeability in the field of toner for developing an electrostatic latent image can be used. For example, fluorine-based surfactants, salicylic acid metal complexes, metal-containing dyes such as azo-based metal compounds, polymer acids such as copolymers containing maleic acid as a monomer component, calixarene compounds, organic boron compounds, and the like. Can be used.
[0048]
The toner of the present invention can be obtained by melt-kneading a binder resin, a wax, a colorant, and other desired additives, cooling, and then pulverizing and classifying. At this time, the above-mentioned wax dispersion particle size distribution of the toner is achieved by appropriately selecting the kneading conditions and the cooling conditions as described above. The two kinds of waxes may be used to be mixed simultaneously with the toner material such as the binder resin and the colorant, or may be used so that one of them is added in advance at the time of synthesizing the binder resin as described above.
The volume average particle diameter of the toner is 4 to 10 μm, preferably 5 to 8 μm.
[0049]
In the present invention, it is preferable that the obtained toner particles are further subjected to a mixing treatment of inorganic fine particles and then subjected to an instantaneous heating treatment (surface modification treatment). Since the detachment (release) of the wax particles is effectively prevented in the toner of the present invention, the toner particles are subjected to instantaneous heat treatment, whereby the toner particles are effectively made spherical with almost no generation of coalesced particles. As a result, a high-definition image can be effectively provided.
[0050]
By mixing the inorganic particles with the toner particles before the instantaneous heat treatment (hereinafter abbreviated as pretreatment of the inorganic particles), the fluidity of the toner particles is improved, and the uniform dispersibility during the instantaneous heat treatment is improved. I do. Further, it is possible to prevent the toner particles from aggregating during the heat treatment.
[0051]
Examples of the inorganic fine particles include various carbides such as silicon carbide, boron carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, tantalum carbide, niobium carbide, tungsten carbide, chromium carbide, molybdenum carbide, calcium carbide, and diamond carbon lactam. , Boron nitride, titanium nitride, various nitrides such as zirconium nitride, borides such as zirconium boride, oxides, titanium oxide, calcium oxide, magnesium oxide, zinc oxide, copper oxide, aluminum oxide, silica, colloidal silica, etc. Various oxides, various titanate compounds such as calcium titanate, magnesium titanate, strontium titanate, sulfides such as molybdenum disulfide, fluorides such as magnesium fluoride and carbon fluoride, aluminum stearate, and calcium stearate May be used zinc stearate, various metal soaps such as magnesium stearate, talc, various non-magnetic inorganic fine particles of bentonite alone or in combination. Such inorganic fine particles have a BET specific surface area of 10 to 350 m.²/ G can be used.
[0052]
The instantaneous heat treatment is performed by dispersing and spraying toner particles in compressed air with hot air.
An example of a schematic configuration diagram of an apparatus for performing an instantaneous heat treatment will be briefly described with reference to FIGS.
As shown in FIG. 2, the high-temperature high-pressure air (hot air) prepared by the hot air generator 101 is injected from a hot air injection nozzle 106 through an introduction pipe 102. On the other hand, the toner particles 105 are conveyed from the fixed amount supply device 104 by a predetermined amount of pressurized air through the introduction pipe 102 ′, and are sent to the sample ejection chamber 107 provided around the hot air ejection nozzle 106.
[0053]
As shown in FIG. 3, the sample ejection chamber 107 has a hollow donut shape, and a plurality of sample ejection nozzles 103 are arranged at equal intervals on the inner wall thereof. The toner particles sent into the sample ejecting chamber 107 are diffused and uniformly dispersed in the ejecting chamber 107, and are ejected from the plurality of sample ejecting nozzles 103 into the hot air stream by the pressure of the subsequently sent air.
[0054]
Further, it is preferable to provide the sample injection nozzle 103 with a required inclination so that the jet flow of the sample injection nozzle 103 does not cross the hot air flow. Specifically, it is preferable that the toner jet flow is jetted along the hot air flow to some extent, and the angle between the toner jet flow and the flow direction of the central region of the hot air flow is 20 to 40 °, preferably 25 to 35 °. .
[0055]
Further, a plurality of sample injection nozzles 103 are required, and at least three or more and four or more are preferable. By using a plurality of sample injection nozzles, it is possible to uniformly disperse the toner particles in the hot air stream, and it is possible to reliably perform the heat treatment for each toner particle. As for the state of being ejected from the sample ejection nozzle, it is desirable that the material is widely diffused at the time of ejection and is dispersed throughout the hot air stream without colliding with other toner particles.
[0056]
The toner particles ejected in this way are instantaneously brought into contact with high-temperature hot air and uniformly heated. Here, the term “instantaneous” refers to the time during which the necessary modification (heating treatment) of the toner particles is achieved and the aggregation of the toner particles does not occur, depending on the processing temperature and the concentration of the toner particles in the hot air stream. , Usually 2 seconds or less, preferably 1 second or less. This instantaneous time is expressed as a residence time of the toner particles until the toner particles are ejected from the sample ejection nozzle and introduced into the introduction pipe 102 ". When the residence time exceeds 2 seconds, coalesced particles are generated. It will be easier.
[0057]
Next, the instantaneously heated toner particles are immediately cooled by the cold air introduced from the cooling air introduction unit 108, and are collected by the cyclone 109 via the introduction pipe 102 "without adhering to the device wall or agglomerating the particles. The toner particles are collected and stored in a product tank 111. The transport air after the toner particles are collected further passes through a bag filter 112 to remove fine powder, and is then discharged to the atmosphere via a blower 113. The cyclone 109 It is preferable to provide a cooling jacket through which cooling water flows to prevent aggregation of toner particles.
[0058]
Other important conditions for performing the instantaneous heat treatment include the amount of hot air, the amount of dispersed air, the dispersed concentration, the processing temperature, the temperature of cooling air, the amount of suction air, and the temperature of cooling water.
The hot air flow is the amount of hot air supplied by the hot air generator 101. It is preferable to increase the amount of hot air in order to improve the uniformity of heat treatment and the processing capacity.
The dispersed air volume is an air volume sent into the introduction pipe 102 'by pressurized air. Although depending on other conditions, it is preferable that the amount of the dispersed air be reduced and heat-treated because the dispersed state of the toner particles is improved and stabilized.
The dispersion concentration refers to the dispersion concentration of the toner particles in the heat treatment region (specifically, the nozzle discharge region). The preferred dispersion concentration depends on the specific gravity of the toner particles, and the value obtained by dividing the classification concentration by the specific gravity of each toner particle is 50 to 300 g / m2.³, Preferably 50 to 200 g / m³It is preferred to treat with.
[0059]
The processing temperature refers to the temperature in the heat treatment region. In the heat treatment region, a temperature gradient actually exists from the center to the outside, but it is preferable to reduce the temperature distribution for the treatment. From the device side, it is preferable to supply the wind in a stabilized laminar flow state by a stabilizer or the like.
The cooling air temperature is the temperature of the cooling air introduced from the cooling air introduction unit 108. After the instantaneous heat treatment, the toner particles are preferably returned to an atmosphere having a temperature equal to or lower than the glass transition point by cooling air in order to instantly cool the toner particles to a temperature range where aggregation or coalescence of the toner particles does not occur.
The suction air volume means air for conveying the toner particles processed by the blower 113 to the cyclone. It is preferable to increase the amount of the suction air from the viewpoint of reducing the cohesiveness of the toner particles.
The cooling water temperature refers to the temperature of the cooling water in the cooling jacket provided in the cyclones 109 and 114 and the introduction pipe 102 ″.
[0060]
An external additive is added to the toner particles subjected to the instantaneous heat treatment. As an external additive, at least a BET specific surface area of 100 to 300 m²/ G, preferably 150 to 250 m²/ G of first inorganic fine particles having a BET specific surface area of 5 to 30 m²/ G, preferably 5 to 20 m²/ G of second inorganic fine particles. By externally adding the first inorganic fine particles, the fluidity of the toner is improved, and the uniformity of charging is improved, so that stable durability characteristics are exhibited over a long period of time. When the second inorganic fine particles are externally added, the particles exist as spacers between the toner particles, and the aggregation of the toner particles is prevented, so that the heat-resistant storage property is further improved.
[0061]
As the material of the first inorganic fine particles and the second inorganic fine particles, the same material as the inorganic fine particles described above can be used, but it is preferable to use silica as the first inorganic fine particles. As the second inorganic fine particles, it is preferable to use a titanate compound, particularly strontium titanate.
[0062]
The amount of the first inorganic fine particles is preferably 0.3 to 3.0% by weight based on the toner particles. The added amount of the second inorganic fine particles is preferably 0.3 to 3.0% by weight based on the toner particles.
[0063]
When fixing the toner image composed of the toner of the present invention as described above, the toner image was carried on a heating member and a pressure member disposed in pressure contact with the heating member or a pressure contact portion of the pressure heating member. It is preferable to employ an oilless fixing method that does not require a fixing oil, including passing a recording sheet (for example, paper). In particular, from the viewpoint of effectively achieving separation of the paper from the heating member, the press contact portion is used. Is preferably convex upward. Further, the surface of the heating member is made of a fluororesin, for example, PFA (ethylene tetrafluoride-perfluoroalkylvinyl ether copolymer), polytetrafluoroethylene, polyfluorinated from the viewpoint of further improving the separation property between the paper and the heating member. It is preferably formed from vinylidene.
[0064]
As an oilless fixing device employing such a fixing method, for example, a fixing device schematically shown in FIG. 4 can be preferably used. The fixing device in FIG. 4 uses a heating roller 11 as a heating member and a pressure roller 12 as a pressure member. Specifically, the heating roller 11, a pressure roller 12 pressed against the heating roller, a separation claw 13 for separating the sheet after fixing from the heating roller, a cleaning web 14 for cleaning the surface of the heating roller, and a cleaning web The apparatus includes a web roller 15 that is turned, and a winding roller 16 that winds up the cleaning web. The heating roller 11 usually has an elastic layer 18 and a surface layer 19 on an aluminum core 17 and a heater 20 inside the aluminum core. The pressure roller 12 generally has an elastic layer 22 and a surface layer 23 on an aluminum core 21. The material of the elastic layer (18, 22) is not particularly limited, but is preferably silicone rubber. The material of the surface layer (19, 23) is not particularly limited, but is preferably a fluororesin, particularly PFA.
In FIG. 4, a nip 24 having a convex shape on the heating roller side (upper side) is formed at a pressure contact portion between the heating roller 11 and the pressure roller 12. The fixing is performed by passing the recording sheet 25 carrying the toner image 26 from the right to the left in the drawing in the pressing portion.
[0065]
【Example】
(Production Example of Polyester Resin (Resin 1 to 3) with Internal Wax)
Styrene, butyl acrylate as a monomer of the vinyl-based resin, and dicumyl peroxide as a polymerization initiator were put into a funnel. Next, as a monomer of the polyester, fumaric acid was added as a bi-reactive compound among the alcohol component and the acid component, and further among the acid components, in the ratios shown in Table 1, and dibutyl peroxide was used as an esterification catalyst. The wax was added in the amount shown in Table 1 to a glass four-necked flask equipped with a thermometer, a stainless steel stirring rod, a falling condenser, and a nitrogen inlet tube, and heated and stirred in a mantle heater under a nitrogen atmosphere. Meanwhile, the vinyl-based resin monomer and the polymerization initiator prepared in advance were removed from the removal funnel over time. Thereafter, the addition polymerization reaction was aged while being kept at a constant temperature, and then the temperature was raised again to cause a condensation polymerization reaction. The progress of the reaction was followed by measuring the acid value or the softening point. The reaction was terminated when a predetermined acid value or softening point was reached, and the mixture was cooled to room temperature to obtain a composite polyester resin.
[0066]
(Production Example of Polyester Resin (Resin 5) with Internal Wax)
In a glass four-necked flask equipped with a thermometer, a stainless steel stirring rod, a falling condenser, and a nitrogen inlet tube, the alcohol component and the acid component were added at the ratio shown in Table 1 to the polymerization initiator (dibutyltin oxide) and Placed with the indicated wax. This was reacted by heating while stirring and heating in a mantle heater under a nitrogen stream. The progress of the reaction was followed by measuring the acid value. When the acid value reached a predetermined value, each reaction was terminated and cooled to room temperature to obtain a polyester resin.
[0067]
(Production Example of Polyester Resin (Resin 4) Without Adding Wax)
A polyester resin was obtained in the same manner as in the production example of Resin 5, except that no wax was used and the alcohol component and the acid component of the polyester resin were used in the ratios shown in Table 1.
[0068]
Each of the obtained polyester resins was roughly crushed to 1 mm or less and used in the production of the following toner. Table 2 shows the physical property values of each polyester resin.
[0069]
[Table 1]

[0070]
In the table, the amount of wax added indicates the ratio of the amount of wax used to the sum of the amount of wax used and the total amount of monomers used for the polyester resin and vinyl resin.
Abbreviations are as follows.
BPA-PO: bisphenol A propylene oxide adduct,
BPA-EO: bisphenol A ethylene oxide adduct,
TPA: terephthalic acid,
TMA: trimellitic acid,
DSA: succinic acid derivative,
St: styrene,
BA: butyl acrylate
[0071]
[Table 2]

[0072]
The wax used in the examples is shown below.
[Table 3]

[0073]
Manufacture of pigment masterbatch
The pigments used in the production of the full-color toner below are the binder resin used in the examples and the C.I. I. Pigment Red 57-1 was charged into a pressure kneader at a weight ratio of 7: 3 and kneaded at 120 ° C. for 1 hour. After cooling, the mixture was coarsely pulverized with a hammer mill to obtain a pigment master batch having a pigment content of 30% by weight.
[0074]
Example of toner production
(Example 1)
As shown in Table 4, Resin 1 and Resin 4 were used in a weight ratio of 65:35 as the binder resin. With respect to 100 parts by weight of the binder (including the weight of the internally added wax), C.I. I. Pigment Red 57-1 (manufactured by Fuji Dye Co., Ltd.) after sufficiently mixing 4.0 parts by weight of a master batch and 1.0 part by weight of oxidized low molecular weight polypropylene (100TS: manufactured by Sanyo Chemical Co., Ltd.) using a Henschel mixer. The mixture was melt-kneaded using a twin-screw extruder (PCM-63: manufactured by Ikegai Iron Works). The kneading conditions were a kneading portion ratio of 25%, a cylinder temperature of 120 ° C., and a screw rotation of 200 rpm. The obtained kneaded material was rolled to a thickness of 2 mm by a cooling press, cooled by a cooling belt, and coarsely pulverized by a feather mill. Thereafter, the mixture is pulverized by a mechanical pulverizer (KTM: manufactured by Kawasaki Heavy Industries, Ltd.) to an average particle diameter of 10 to 12 μm, and further classified by a jet pulverizer (IDS: manufactured by Nippon Pneumatic Industries, Ltd.) to obtain an average particle diameter of 6 μm. After pulverizing to 0.8 μm, fine powder classification was performed using a rotor type classifier (Tiplex type classifier type: 100 ATP: manufactured by Hosokawa Micron Corporation) to obtain magenta toner particles having a volume average particle size of 7.5 μm.
[0075]
With respect to 100 parts by weight of the toner particles, 1.0 part by weight of hydrophobic silica (TS-500: manufactured by Cabosil) and hexamethylene disilazane-treated hydrophobic silica (AEROSIL @ 90G; manufactured by Nippon Aerosil); BET Specific surface area 65m²/ G, pH 6.0, hydrophobicity of 65% or more), and mixed by a Henschel mixer (peripheral speed: 40 m / sec, 60 seconds). The surface was modified by heat under the conditions to obtain magenta toner particles. Further, a BET specific surface area of 225 m²/ G hydrophobic silica fine particles (TS-500; manufactured by Cabosil Co., Ltd.) 0.5 part by weight and BET specific surface area 9 m²/ G of strontium titanate fine particles at a peripheral speed of 40 m / s for 3 minutes with a Henschel mixer, followed by sieving with a sieve having openings of 106 μm to obtain a toner.
[0076]
(Conditions for surface modification treatment)
Developer supply unit; table feeder + vibratory feeder
Dispersion nozzles: 4 (Symmetrical arrangement of 90 degrees each for the entire circumference)
Spout angle: 30 degrees
Hot air flow: 800 L / min
Dispersed air volume: 55 L / min
Suction air volume: -1200 L / min
Dispersion concentration: 100 g / m³
Processing temperature: 180 ° C
Residence time: 0.5 seconds
Cooling air temperature: 15 ° C
Cooling water temperature; 10 ° C
[0077]
(Examples 2 to 11, Comparative Examples 1 to 4, and Reference Examples)
A toner was obtained in the same manner as in Example 1, except that the type and mixing ratio of the resin constituting the binder resin, the type and amount of the externally added wax, and the kneading and cooling conditions were changed as shown in Table 4.
[0078]
[Table 4]

[0079]
In the table, the amount of the internally added wax is the amount of the internally added wax contained in 100 parts by weight of the binder resin (including the weight of the internally added wax).
The Tm of the mixed resin is the Tm of the binder resin containing the internally added wax.
The amount of the externally added wax is a value based on 100 parts by weight of the binder resin (including the weight of the internally added wax).
[0080]
Evaluation
(Heat-resistant)
20 g of the toner was placed in a glass bottle, left at a high temperature of 55 ° C. for 24 hours, and the toner was visually checked.
：: no aggregation toner, no problem;
Δ: Light soft agglomeration is present, but it can be easily released with a light force and has no practical problem;
X: There is a strong agglomerate, which cannot be easily understood, and has a practical problem.
[0081]
(Fusing separation test)
Using a full-color printer LP-3000C (manufactured by Epson Corporation) of a non-magnetic one-component developing method, a solid image having a width of 36 mm and a width of 36 mm at the leading end with a test pattern A4 lengthwise paper (adhesion amount 5 g / m2)²) To form an unfixed image. This unfixed image was fixed at various fixing temperatures using the following fixing device, and a separable / non-offset temperature range was obtained. The temperature range refers to a fixing temperature range in which the separation of the paper from the heating roller is performed well and the offset phenomenon does not occur. The paper used and the paper passing direction are 64 g / m, which is disadvantageous for separation.²The test was performed by passing the Y-th piece of paper vertically. The peripheral speed of the fixing device was 120 mm / sec.
[0082]
The fixing device is a device shown in FIG. 4, and is a soft roller type having a fluorine surface layer composition. Specifically, the heating roller 11 has an outer diameter of 40 mm, an elastic layer 18 of 1.5 mm thick made of silicone rubber on an aluminum core 17 and a PFA (ethylene tetrafluoride-perfluoroalkyl vinyl ether copolymer) surface layer. And a heater 20 inside the aluminum core. The pressure roller 12 has an outer diameter of 35 mm, an elastic core layer 22 made of silicone rubber and a PFA surface layer 23 made of silicone rubber on an aluminum core 21. A nip (nip width: 7 mm) 24 having a convex shape on the side of the heating roller is formed in the pressure portion between the heating roller 11 and the pressure roller 12. 4 further includes a separation claw 13 for separating the sheet after fixing from the heating roller 11, a cleaning web 14 for cleaning the surface of the heating roller 11, a web roller 15 around which the cleaning web is wound, and a cleaning web. The configuration was such that the take-up roller 16 was provided, but the experiment was performed without using the fixing oil.
[0083]
：: Separable / non-offset temperature range was 50 ° C. or higher;
Δ: Separable / non-offset temperature range was 30 ° C. or more and less than 50 ° C .;
X: The separable / non-offset temperature range was less than 30 ° C.
[0084]
(Image gloss)
The gloss was measured using a gloss meter (GM-060; manufactured by Minolta). Using a full-color printer LP-3000C (manufactured by Epson Corporation), a 1.5 cm × 1.5 cm solid image (adhesion amount: 2.0 mg / cm²) To form an unfixed image. This unfixed image was fixed at a fixing temperature of 160 ° C. using the fixing device of FIG. 4, and the glossiness of each image was measured.
A glossiness of 30 or more was rated as ○, a glossiness of 20 or more and less than 30 was rated as Δ (no practical problem), and a glossiness less than 20 was rated as x (practical problem).
[0085]
(High temperature offset property)
Using a full-color printer LP-3000C (manufactured by Epson Corporation), an unfixed image on which a halftone image was printed was created. The unfixed image is fixed using the fixing device of FIG. 4 while changing the fixing temperature in a range of 130 ° C. to 190 ° C. in steps of 5 ° C., and the state of offset of the image is visually observed. The temperature at which high-temperature offset occurs was evaluated. A sample having a high-temperature offset temperature of 160 ° C. or higher was evaluated as ○, and a sample having a temperature of 155 ° C. or higher but lower than 160 ° C. was evaluated as Δ (no practical problem).
[0086]
(Cleaning BS (CL-BS))
Using a full-color printer LP-3000C (manufactured by Epson Corporation), a predetermined print pattern having a B / W ratio of 6% was continuously printed in an N / N environment (23 ° C., 45%). After continuous printing of 2000 sheets (after endurance) in an N / N environment, the photosensitive member and the intermediate transfer belt were visually observed and evaluated. The criteria are as follows.
：: No filming or black spot (BS) occurred on the photoreceptor and the intermediate transfer member, and there was no problem at all;
Δ: Filming and BS were observed on one of the photoreceptor and the intermediate transfer member, but were not visible on the copied image, and there was no practical problem;
X: Filming and BS occurred on the photoreceptor and / or the intermediate transfer member, which could be confirmed on the image, and had a practical problem.
[0087]
(Omission during transfer)
Continuous printing was performed in the same manner as in the evaluation method of the cleaning property, and a copied image after continuous copying of 2000 sheets (after endurance) under an N / N environment was visually observed to evaluate the hollow portion. The criteria are as follows. The amount of toner adhered on paper was changed to 1.0 mg / cm by changing the bias setting.²(± 0.1).
：: no void was found on the image;
Δ: Defects occurred on the image, but there was no practical problem;
X: Many hollows occurred on the photographed image, and there was a practical problem.
[0088]
(Insufficient cleaning regulation)
Continuous copying was performed in the same manner as in the evaluation method of the cleaning property. After continuous copying of 2000 sheets (after endurance) in an N / N environment, the state of the sleeve of the developing device and the copied image were visually observed and evaluated. The criteria are as follows.
：: No streak or unevenness occurred on the sleeve;
Δ: Although some streaks or unevenness occurred on the sleeve, there were no vertical streaks on the copied image, and there was no practical problem;
×: Many streaks or unevenness occurred on the sleeve, and there were practical problems such as abnormal noise, toner sticking and toner spilling.
[0089]
(Number of wax particles-particle size distribution)
About 10 mg of the toner is dissolved in chloroform and centrifuged, and the floating wax particles are collected. A photographic image of the wax particles is input to an image analyzer (Luzex 5000; manufactured by Nippon Regulator Co., Ltd.) using a scanning electron micrograph. The particle size distribution was measured. In the case where the wax particles are not perfectly spherical, the maximum diameter of the wax particles is measured to determine the particle diameter of each wax particle.
[0090]
[Table 5]

[0091]
(Various physical property evaluation methods)
<Glass transition point (Tg) measurement method>
Using a differential scanning calorimeter (DSC-200: manufactured by Seiko Denshi), precisely weigh 10 mg of the sample to be measured, put it in an aluminum pan, and use an aluminum pan in which aluminum was used as a reference to raise the temperature. After the temperature was raised from room temperature to 200 ° C. at a rate of 30 ° C./min, it was cooled and measured at a rate of 10 ° C./min between 20 ° C. and 120 ° C. The shoulder value of the main endothermic peak in the range of 90 ° C. was defined as Tg.
[0092]
<Softening point (Tm) measurement method>
Using a flow tester (CFT-500: manufactured by Shimadzu Corporation), 1.0 g of a sample to be measured is weighed, and a die having a size of 1.0 mm × φ1.0 mm is used. The measurement was performed under the conditions of 180 seconds, a load of 30 kg, and a measurement temperature range of 60 to 140 ° C., and the temperature at which the sample flowed out by １ ／ was defined as the resin softening point (Tm).
[0093]
<Acid value measurement method>
A 10 mg sample was dissolved in 50 ml of toluene, and titrated with a pre-standardized N / 10 potassium hydroxide / alcohol solution using a mixed indicator of 0.1% bromthymol blue and phenol red. This is a value calculated from the consumption of the potassium / alcohol solution.
[0094]
<Hydroxy value>
The hydroxyl value was expressed in mg of potassium hydroxide required to treat a weighed sample with acetic anhydride, hydrolyze the obtained acetyl compound, and neutralize liberated acetic acid.
<Method of measuring THF insoluble content>
The THF-insoluble content was measured by Soxhlet extraction for 10 hours using tetrahydrofuran as a solvent.
[0095]
【The invention's effect】
Even when the toner of the present invention is manufactured by a kneading and pulverizing method, it can be effectively applied to an oilless fixing system. That is, good fixing separation properties and offset resistance can be exhibited in a wide temperature range. The toner of the present invention is further excellent in image quality, cleaning properties, transfer properties, and heat storage stability.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a twin-screw extruder and a cooler suitable for producing the toner of the present invention.
FIG. 2 shows a schematic configuration diagram of an apparatus for performing an instantaneous heat treatment.
3 shows a schematic horizontal sectional view of a sample ejection chamber in the apparatus of FIG.
FIG. 4 is a schematic configuration diagram of a fixing device suitable for the toner of the present invention.
[Explanation of symbols]
1: twin screw extruder kneader, 2: cooler, 3: cylinder, 4: motor, 101: hot air generator, 102, 102 ', 102 ": introduction pipe, 103: sample injection nozzle, 104: retained powder , 105: toner particles, 106: hot air injection nozzle, 107: injection chamber, 108: cooling air introduction part, 109: cyclone, 111: product tank, 112: bag filter, 113: blower, 114: conical part, 115: feeder , 11: heating roller, 12: pressure roller, 13: separation claw, 14: cleaning web, 15: web roller, 16: winding roller, 17: core metal, 18: elastic layer, 19: surface layer, 20: Heater, 21: core metal, 22: elastic layer, 23: surface layer, 24: nip, 25: recording sheet, 26: toner image.

Claims (7)

It is composed of at least a binder resin, two types of waxes incompatible with the binder resin, and a colorant, and has a standard deviation of 0.4 to less than 2.0 in the number-particle size distribution of dispersed particle diameters of the wax. The peak is between 1.0 and 1.5 μm, the number ratio of wax particles of 1.0 to less than 1.5 μm is 20% or more and less than 40%, and the number ratio of wax particles of 2.5 μm or more is 20% or less. % Toner composition. In the number-particle size distribution of the dispersed particle diameter of the wax, the number ratio of the wax particles having a size of 1.0 to less than 1.5 μm is 23% or more and less than 32%, and the number ratio of the wax particles having a size of 2.5 μm or more is 1% or more. The toner composition according to claim 1, which is less than 17%. The toner composition according to claim 1, wherein the number average particle diameter in the number-particle size distribution of the dispersed particle diameter of the wax is 1.2 μm or more and less than 2.5 μm. 4. The toner composition according to claim 1, wherein the two waxes are polyolefins. The toner composition according to claim 1, wherein the two types of wax are polypropylene and polyethylene. The toner composition according to claim 1, wherein the two types of waxes have different melting points, and the amount of the wax having a relatively low melting point is larger than that of the wax having a relatively high melting point. The toner composition according to any one of claims 1 to 6, wherein one of the two waxes is internally added during the synthesis of the binder resin.

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