JP3941213B2 - Toner for electrostatic image development - Google Patents

Description

をヘンシェルミキサーで充分混合し、二軸押出混練機で溶融混練後、冷却しその後、ハンマーミルで粗粉砕しジェット粉砕機で微粉砕した後、分級して体積平均粒径７．０μｍのトナー粒子Ｂｋ−１を得た。
【０１０９】
製造例 Ｂｋ−２〜９
トナーの製造例Ｂｋ−１で得られたトナー粒子を用い、Ｙ−２〜５と同様の熱処理前の流動化処理とし、熱処理の温度水準として、２７０，１７０、２２０，３２０℃と変更する以外は同様の条件で熱処理条件によりトナー粒子Ｂｋ−２〜５を得た。また、Ｙ−６〜９の製法に準じ、熱処理温度をそれぞれ、２７０、１７０、２２０、３２０℃として、となー粒子Ｂｋ−６〜９を得た。
【０１１０】
製造例 Ｂｋ−１０
スチレン６０重量部、ｎ−ブチルメタクリレート３５重量部、メタクリル酸５重量部、２−２アゾビス（２，４−ジメチルバレロニトリル）０．５重量部、低分子量ポリプロピレン（ビスコール６６０Ｐ；三洋化成工業社製）３重量部、カーボンブラック（ＭＡ＃８；三菱化学社製）８重量部およびクロム錯体（アイゼンスピロンブラックＴＲＨ；保土ヶ谷化学工業社製）をサンドスターラーにより混合して重合組成物を調整した。この重合組成物を濃度３重量％のアラビアゴム水溶液中で攪拌機ＴＫオートホモミクサー（特殊機化工業社製）を用いて回転数４３００ｒｐｍで攪拌しながら、６０℃で６時間重合反応させ、平均粒径６．０μｍの球状粒子を得た。球状粒子の濾過／水洗を３回繰り返した後、濾過物を３５℃、３０％ＲＨの環境下にて風乾し、トナー粒子Ｂｋ−１０を得た。
これらトナー粒子にＢＥＴ比表面積１４０ｍ２／ｇの疎水性シリカ微粒子（Ｒ−９７２；日本アエロジル社製）０．５重量％およびチタン酸ストロンチウム微粒子の中径（粒径：３５０ｎｍ、ＢＥＴ比表面積：９ｍ２／ｇ）０．５重量％を加えてヘンシェルミキサーにて周速４０ｍ／ｓｅｃの条件で３ｍｉｎ混合した後、目開き１０６μｍの篩で篩って評価に用いるトナーを調整した。
【０１１１】
各種物性評価方法
・樹脂のガラス転移点Ｔｇの測定法
示差走査熱量計（ＤＳＣ−２００：セイコー電子社製）を用いて、リファレンスをアルミナとし、１０ｍｇの試料を昇温速度１０℃／ｍｉｎの条件で２０〜１２０℃の間で測定し、メイン吸熱ピークのショルダー値をガラス転移点とした。
【０１１２】
・樹脂の軟化点Ｔｍの測定法
フローテスター（ＣＦＴ−５００：島津製作所社製）を用い、ダイスの細孔（径１ｍｍ、長さ１ｍｍ）、加圧２０ｋｇ／ｃｍ２、昇温速度６℃／ｍｉｎの条件下で１ｃｍ２の試料を溶融流出させたときの流出開始点から流出終了点の高さの１／２に相当する温度を軟化点とした。
・分子量はゲルパーミエーションクロマトグラフィ（８０７−ＩＴ型；日本分光工業社製）を使用し、キャリア溶媒としてテトラヒドロフランを使用して、ポリスチレン換算により分子量を求めた。
【０１１３】
酸価は、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。
【０１１４】
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化カリウムのｍｇで表した。
【０１１５】
疎水化度は、２００ｍｌのビーカーに純水５０ｍｌを入れ、０．２ｇのシリカ等の無機微粒子を添加する。ビーカーを攪拌しながら、ビューレットから無水硫酸ナトリウムで脱水したメタノールを加え、液面上にシリカ等がほぼ認められなくなった点を終点として要したメタノール量から下記式により疎水化度を算出する。
疎水化度（％）＝Ｃ／（５０＋Ｃ）×１００
式中 Ｃは、メタノール使用量（ｍｌ）を表す
【０１１６】
体積平均粒径と円形度は（相当円の周囲長／粒子投映像の周囲長）で表され、フロー式粒子像解析装置（ＦＰＩＡ−２０００：東亞医用電子社製）を用いて水分散系で測定した。
【０１１７】
スリーブ上トナー粒径の評価は、ホッパー中トナー粒径（平均粒径＆微粉成分の個数％）の違いについて、評価した。
○：１０％以内の差で収まっている
△：１０〜２０％の差が認められる
×：２０％以上の粒径選別を引き起こしている
【０１１８】
トナー性能の評価
上記の実施例および比較例で選択されたフルカラー現像用トナーを、以下に示す項目について評価した。なお、評価はＨ／Ｈ環境下（３０℃／８５％ＲＨ）およびＬ／Ｌ環境下（１０℃／１５％ＲＨ）で行った。なお、実施例５および比較例３においては、所定のプリントパターンで、他の実施例１〜４および比較例１および２同様にＨ／ＨならびにＬ／Ｌ環境下で初期評価を行った後、さらにＮ／Ｎ環境下（２５℃／５０％ＲＨ）でＢ／Ｗ比が各色６％のプリントパターンを用いて３０００枚連続複写後に評価を行った。実施例５および比較例３での３０００枚連続複写後の評価方法は、Ｎ／Ｎ環境下で評価を行ったこと、３０００枚複写後に評価を行ったこと、各色６％のプリントパターンを用いたこと以外、以下の評価方法と同様である。評価はカラー・ページ・プロＴＭＰＳ（ミノルタ株式会社製）を使用した（ただし、クリーニング方式をブラシクリーニング方式に変更した）。
【０１１９】
中抜け
上記フルカラートナー現像用ドナーを、フルカラー画像形成装置（ミノルタ株式会社製）に装填し、４色重ね刷りによりフルカラー画像（ジェネラルパターン）を複写し、１０枚複写後におけるフルカラー複写画像を、以下のランク付けに従って評価した。なお、４種類のトナーは、４つの現像装置に、中間転写ベルト上の層形成順序が下からＹ、Ｍ、Ｃ、Ｂｋとなるように装填されている。
○：複写画像上に中抜けは発生しなかった。
△：複写画像上に中抜けが若干発生しているものの、実用上問題無かった。
×：複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。
【０１２０】
飛び散り
上記フルカラー現像用トナーを、上記フルカラー画像形成装置に装填し、４色重ね刷りによりフルカラー画像（ジェネラルパターン）を複写し、１０枚複写後における複写画像を、以下のランク付けに従って評価した。なお、４種類のトナーは、４つの現像装置に、中間転写ベルト上の層形成順序が下からＹ、Ｍ、Ｃ、Ｂｋとなるように装填されている。
○：ライン複写画像のまわりにトナーの飛び散りは認められなかった。
△：ライン複写画像のまわりにトナーの飛び散りは認められるものの、実用上問題無かった。
×：複写画像のまわりにトナーの飛び散りが多く認められ、にじみとして認識され、実用上問題があった。
【０１２１】
カブリ
上記フルカラー現像用トナーを、上記フルカラー画像形成装置に装填し、４色重ね刷りによりＢ／Ｗ比３０％の文字パターン画像を連続して１０枚複写した際の複写画像を目視により観察し、以下のランク付けに従って評価した。なお、４種類のトナーは、４つの現像装置に、中間転写ベルト上の層形成順序が下からＹ、Ｍ、Ｃ、Ｂｋとなるように装填されている。
○：ほとんどカブリは認められなかった。
△：若干のカブリは認められるが、実用上問題無かった。
×：カブリが全面にわたって存在し、実用上問題があった。
【０１２２】
転写性
上記フルカラー現像用トナーを、上記フルカラー画像形成装置に装填し、単色画像のソリッドパターンを複写し、１０回目の複写工程における感光体ドラム上のトナー付着量に対する紙上の付着量の割合から、以下のランク付けに従って評価した。
○：８０％以上、
△：７０〜８０％未満
×：７０％未満
【０１２３】
ドット再現性
６００ｄｐｉで２ドット網点の画像を画出し、ルーペ（５０倍）でドットを観察し、ドットが一つづつ再現されており、ドットのばらつきの小さいものものを○、ドットとドットは分離されており、欠損は無いが、ドットの大きさにばらつきの多いものを△、２ドットの一つ一つが欠損していたり、くっついていたりし、十分にドットとして再現されていないものを×として評価した。
【０１２４】
ライン再現性
６００ｄｐｉで２ドットラインの画像を画出し、ルーペ（５０倍）で線幅の変動とライン画像周りの飛び散りトナーを観察した。
○：線幅のばらつき、飛び散りトナー共に少ないもの、
△：どちらか一方が劣るもの、
×：両方劣るもの。
【０１２５】
画像スジ：
Ｂ／Ｗ３０％で１０枚、通紙後、Ｂ／Ｗ１００％の画像をプリントアウトし、スジ状のノイズの有無を評価した。
○：画像スジなし、
△：若干の画像スジは発生したが、実用上問題ない程度のもの、
×：画像スジ発生、実用上問題あり。
【０１２６】
追随性
Ｂ／Ｗ３０％で１０枚、通紙後、Ｂ／Ｗ１００％の画像をプリントアウトし、その濃度むらを評価した
○：濃度むらなし、
△：若干の濃度むらは発生したが、実用上問題ない程度のもの、
×：濃度むら発生、実用上問題あり。
【０１２７】
スリーブ上トナー粒径：
ホッパー中のトナー粒径（平均粒径と微粉成分の個数％）の差で評価した。
○：１０％以内の差で収まっている。
△：１０〜２０％の差が認められる。
×：２０％以上の粒径選別を起こしている。
【０１２８】
トナーの特数を表１および表２に、評価結果を表３および表４に示す。
【表１】

【０１２９】
【表２】

【０１３０】
【表３】

【０１３１】
【表４】

【０１３２】
【発明の効果】
本発明トナーにおいては、トナー中の小径トナーの帯電量が下がり、現像スリーブ上への優先的な取り込みが軽減でき、また、小径トナーは従来に比べ現像スリーブから離れ易くなって粒径に係わりなく均一な現像を達成でき、更には、現像スリーブと規制部材との間を通過する際のストレスに耐え得るだけの強度を持たせることが出来た。これらの総合作用により、長期にわたって安定した画質を維持することが可能となった。
【図面の簡単な説明】
【図１】 熱風による表面改質処理用装置の概略図。
【図２】 図１の装置の試料噴射室の水平断面模式図。
【符号の説明】
１０１ 熱風発生装置
１０２、１０２’、１０２” 導入管
１０３ 試料噴射ノズル
１０４ 定量供給機
１０５ トナー粒子
１０６ 熱風噴射ノズル
１０７ 試料噴射室
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[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toner for developing an electrostatic latent image. The present invention further relates to a developer using this toner, and more particularly to a developer used in a direct recording apparatus for forming a toner image by directly landing toner on a recording medium from a toner carrier.
[0002]
[Prior art]
Conventionally, toner is supplied onto a developing sleeve, and the toner is frictionally charged by passing between a regulating member arranged in a pressure-bonded manner on the sleeve, and an electrostatic latent image is developed using the formed toner thin layer. A one-component developing apparatus is known.
On the other hand, the distribution of toner used for development varies depending on the product, but it has a particle size distribution, and there are toners with a small particle size and those with a large particle size.
[0003]
When toner having a wide distribution is used in the above-described apparatus, a small-diameter toner having a high mirror image force with respect to the developing sleeve preferentially adheres to the developing sleeve and is taken in, and a toner having a large particle diameter remains as it is used. There is a problem that so-called particle size sorting occurs.
In addition, the charge amount of the small-diameter toner is higher than that of the large-diameter toner in the toner, and the electrostatic adhesion force to the developing sleeve is high, so that the toner tends to accumulate on the sleeve. There is also a problem that image quality deteriorates due to cracking and filming caused by stress when passing between the two. In particular, in recent years, it has been desired to increase the image forming speed, and the above problems become more prominent as the developing speed is increased.
[0004]
In order to solve such problems, attempts have been made to reduce the above-mentioned problems by reducing the small diameter component by sharpening the particle size distribution of the toner.
[0005]
[Problems to be solved by the invention]
In consideration of the above-described problems, an object of the present invention is to provide a toner capable of obtaining a good image over a long period of time.
[0006]
[Means for Solving the Problems]
  The present invention is obtained by an instantaneous heat treatment in which the heat treatment region is 2 seconds or less.Developing an electrostatic latent image using a thin toner layerUsed for electrostatic image developmentOne componentWhen the toner has a volume average particle diameter Dm of 4 to 9 μm, an average circularity Em of 0.96 to 1.00, and an average circularity of a toner component of Dm / 2 or less, where Es> For electrostatic image development characterized by the relationship of 1.001 EmOne componentIt relates to toner. The present invention further relates to a developer using this toner, and more particularly to a developer used in a direct recording apparatus for forming a toner image by directly landing toner on a recording medium from a toner carrier. A technique for easily producing such toner with industrial profitability is also new.
[0007]
The toner of the present invention reduces the charge amount of the small-diameter toner and can reduce the preferential uptake on the developing sleeve. Also, the small-diameter toner is more easily separated from the developing sleeve than the conventional one, and the uniform development is performed regardless of the particle diameter. Further, by increasing the circularity of the small-diameter toner, the strength sufficient to withstand the stress when passing between the developing sleeve and the regulating member can be obtained. These comprehensive actions make it possible to maintain stable image quality over a long period of time.
[0008]
In the present invention, the volume average particle diameter Dm, the average circularity Em, and the average circularity Es of the toner component having a particle diameter of Dm / 2 or less are determined by a flow type particle image analyzer (EPIA-2000: manufactured by Toa Medical Electronics Co., Ltd.). ) Using a water dispersion system. According to this measuring apparatus, it is possible to measure and convert the volume particle size of each particle, the average value for each region and the circularity and the average value of each corresponding particle, and to add or analyze this, so that Dm, Dm / 2 and Em can be determined. If this device is used, the standard deviation of circularity (standard deviation of circularity distribution) can be measured simultaneously with the average circularity. The smaller this value is, the more uniform the toner particle diameter is.
[0009]
In the present invention, the toner has a volume average particle diameter Dm of 2 to 10 μm, more preferably 4 to 9 μm. These ranges are not limited because they are selected in consideration of the toner usage target and the apparatus. However, any toner having the above volume average particle diameter is useful for achieving the object of the present invention.
[0010]
In the present invention, the circularity is:
Circularity = Perimeter of a circle equal to the projected area of the particle / Perimeter of the projected particle image
It is a value represented by That is, the closer to 1, the closer to a circle. As described above, since the circularity is obtained from “peripheral length of a circle equal to the projected area of the particle” and “peripheral length of the projected particle image”, this value is an index reflecting the shape of the toner, particularly the uneven state of the particle surface. Become.
[0011]
The average circularity Em refers to the average value of the circularity of the entire measurement toner (that is, toner having a volume average particle diameter Dm). The average circularity Em is preferably 0.94 to 1.0, more preferably 0.95 to 1.0, and particularly 0.96 to 1.0. Further, the standard deviation value of the toner having the average circularity Em is preferably 0.045 or less, more preferably 0.040 or less, and particularly preferably 0.035 or less.
[0012]
The average circularity Es is the average circularity of the particles having a volume particle diameter of Dm / 2 or less, and this value is also preferably 0.94 to 1.0, more preferably 0.95 to 1.0, particularly, similarly to Em. The standard deviation value of the toner having an average circularity Es of 0.96 to 1.0 is preferably 0.045 or less, more preferably 0.040 or less, and particularly preferably 0.035 or less.
[0013]
In the present invention, Es needs to be larger than 1.001 Em. If Es is smaller than that, the object of the present invention cannot be sufficiently achieved. More preferably, Es> 1.002Em.
[0014]
When the standard deviation value of the circularity of the toner is larger than the above range, it means that the toner shape is not uniform. Therefore, by setting the standard deviation value of the circularity of the toner within the above range, the fluidity of the toner is improved, the surface charge density of the toner becomes uniform, and the variation in the charge amount is reduced. It is possible to suppress a phenomenon in which a small component having a relatively high diameter is first supplied to and consumed by the toner carrier, and it is possible to ensure stable quality over a long period from the initial stage.
[0015]
By reducing surface homogeneity and variations in individual particles, for example, in toner, the rising characteristics of charging can be improved and the charge amount distribution can be sharpened. There is little noise and the image quality can be improved. Further, this prevents a phenomenon such as selective development (a phenomenon in which a toner having a specific particle diameter and charge amount is consumed first) and the like, and a stable toner quality can be ensured even at the time of printing. Therefore, since it becomes possible to suppress the phenomenon that the small diameter component with a high charge amount increases particularly in the initial stage, it is possible to improve the efficiency such as mobility (developability, transferability), etc. The setting condition window expands.
[0016]
Such an effect can be obtained particularly by adjusting the above-mentioned special number of the toner having a small particle diameter. In other words, good results can be obtained with a toner having an average circularity Es of 0.95 or more and a standard deviation value of Es of 0.040 or less.
In the present invention, it is preferable that the toner surface does not have irregularities, cracks, pores, etc. Therefore, D / d50 (where D = 6 (ρ · S) (where D is the shape of the toner and sphere). The converted value from the specific surface area (μm), d50 is the particle size equivalent to 50% of the relative weight distribution by particle size (μm), and ρ is the density (g / cm²), S is the BET specific surface area (m²/ G), the D / d50 is 0.50 or more, and in the case of magnetic toner, 0.20 or more, preferably 0.25 or more. This D / d50 is an index indicating that there are pores on the surface or inside of the toner particles. If the toner has the above value, the toner will be cracked around the pores, or external additives may be present in the recesses. It is possible to suppress the generation of fine powder due to embedding or the removal of the convex portion. Therefore, the toner characteristics can be maintained over a long period.
[0017]
Conventionally, toner surface modification methods by heat are known (for example, JP-A-4-226476, JP-A-6-317928 to 317933, etc.), and any of these methods generates aggregated or coalesced particles. Since it is easy, it is not suitable for obtaining a toner having the special features of the present invention.
The toner of the present invention can be easily obtained by subjecting a toner previously obtained by a conventional method to surface treatment with hot air and then classifying it.
The surface treatment with hot air is preferably performed by dispersing and spraying toner in the hot air with compressed air.
A method is known in which developer particles are dispersed and supplied in a hot air stream to melt the surface of the developer particles and instantly spheroidize the developer particles. Furthermore, it is also known that surface treatment with hydrophobic silica or the like is performed in advance for the purpose of improving the dispersion state of developer particles in hot air. However, even with these methods, sphericity and uniformity cannot be achieved in order to dramatically improve developer characteristics.
[0018]
The instantaneous heat treatment used in the present invention is a method in which toner particles are dispersed and sprayed in hot air with compressed air, so that the surface of the developer is modified by heat, and the sphericity and uniformity that cannot be achieved by the conventional method. To achieve sex.
[0019]
A schematic configuration diagram of an apparatus that performs instantaneous heat treatment will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, high-temperature and high-pressure air (hot air) prepared by the hot air generator 101 is jetted from a hot air jet nozzle 106 through an introduction pipe 102. On the other hand, the toner particles 105 are conveyed by a predetermined amount of pressurized air from a fixed amount supply device 104 through an introduction pipe 102 ′, and are sent into a sample injection chamber 107 provided around the hot air injection nozzle 106.
[0020]
As shown in FIG. 2, 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 injection chamber 107 are diffused and uniformly dispersed in the injection chamber 107, and are subsequently injected from the plurality of sample injection nozzles 103 into the hot air stream by the pressure of the air that is sent in.
[0021]
In addition, 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 so as to follow the hot air flow to some extent, and the angle formed by the flow direction of the central region of the toner jet flow and the hot air flow is 20 to 40 °, preferably 25 to 35 °. . When the angle is larger than 40 °, the jetted toner flow is jetted so as to cross the hot air flow, and the toner particles collide with the toner particles jetted from other nozzles. If it is narrow, toner particles that are not taken into the hot air are generated, and the shape of the toner particles becomes non-uniform.
[0022]
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 jet nozzles, the toner particles can be uniformly dispersed in the hot air stream, and the heat treatment for each toner particle can be performed reliably. As a state of being ejected from the sample ejection nozzle, it is desirable that it is diffused widely at the time of ejection and is dispersed throughout the hot air stream without colliding with other toner particles.
[0023]
The toner particles ejected in this manner are instantaneously brought into contact with high-temperature hot air and subjected to a uniform heat treatment. Here, “instantaneous” means a time during which necessary toner particle modification (heat treatment) is achieved and aggregation of toner particles does not occur, although it varies depending on the processing temperature and the concentration of toner particles in a hot air stream. Usually, it is 2 seconds or less, preferably 1 second or less. This instantaneous time is expressed as the residence time of the toner particles until the toner particles are ejected from the sample ejection nozzle and introduced into the introduction tube 102 ". When this residence time exceeds 2 seconds, coalesced particles are generated. It becomes easy.
[0024]
Next, the instantaneously heated toner particles are immediately cooled by the cold air introduced from the cooling air introduction unit 108 and collected by the cyclone 109 via the introduction pipe 102 "without adhering to the apparatus wall or aggregating the particles. The product air is collected in the product tank 111. The carrier air after the toner particles are collected passes through the bag filter 112, and fine powder is removed, and then is discharged to the atmosphere through the blower 113. Is preferably provided with a cooling jacket through which cooling water flows to prevent aggregation of toner particles.
[0025]
Other important conditions for performing the instantaneous heat treatment are hot air flow rate, dispersed air flow rate, dispersion concentration, processing temperature, cooling air temperature, suction air flow rate, and cooling water temperature.
[0026]
The hot air volume is the volume of hot air supplied by the hot air generator 101. Increasing the amount of hot air is preferable in terms of improving the uniformity and processing capability of the heat treatment.
[0027]
The dispersed air volume is an air volume that is sent into the introduction pipe 102 ′ by pressurized air. Although depending on other conditions, it is preferable that the amount of the dispersed air is suppressed and heat-treated for improving and stabilizing the dispersed state of the toner particles.
[0028]
The dispersion concentration refers to the dispersion concentration of toner particles in a heat treatment region (specifically, a nozzle discharge region). A suitable dispersion concentration varies depending on the specific gravity of the toner particles, and a value obtained by dividing the classification concentration by the specific gravity of each toner particle is 50 to 300 g / m 2.^Three, Preferably 50 to 200 g / m^ThreeIt is preferable to treat with.
[0029]
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 perform the treatment while reducing this temperature distribution. From the aspect of the apparatus, it is preferable to supply the wind in a stabilized laminar flow state by a stabilizer or the like. In a non-magnetic toner using a binder resin having a sharp molecular weight distribution, for example, a binder resin having a weight average molecular weight / number average molecular weight of 2 to 20, the glass transition point of the binder resin + 100 ° C. or higher to the glass transition point + 300 ° C. It is preferable to process in the peak temperature range. More preferably, the treatment is performed in the peak temperature range of the glass transition point of the binder resin + 120 ° C. or more to the glass transition point + 250 ° C. The peak temperature range refers to the maximum temperature in the region where the toner is in contact with hot air.
[0030]
In a non-magnetic toner using a binder resin having a relatively wide molecular weight distribution, for example, a binder resin having a weight average molecular weight / number average molecular weight of 30 to 100, the glass transition point of the binder resin + 100 ° C. or higher to the glass transition It is preferable to treat in the peak temperature range of point + 300 ° C. More preferably, the treatment is performed in the peak temperature range of the glass transition point of the binder resin + 150 ° C. or more to the glass transition point + 280 ° C. This is because, in order to improve the toner shape and surface uniformity, it is necessary to set a higher processing temperature so as to achieve the modification of the high molecular weight region of the binder resin. However, when the processing temperature is set high, coalesced particles are likely to be generated. Therefore, it is necessary to tune the fluidization process before heat treatment to a large value, or to set the dispersion concentration at the time of processing low. .
[0031]
When wax is added to the toner particles, coalescence particles are likely to be generated. Therefore, a large amount of fluidization treatment (particularly a fluidizing agent having a large particle size component) before heat treatment is set. Tuning such as setting a low dispersion density during processing is important in obtaining uniform toner particles with suppressed shape and shape variation. This operation becomes more important when a binder resin having a relatively wide molecular weight distribution is used, or when the processing temperature is set high to increase the sphericity.
[0032]
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 below the glass transition point by cooling air so as to be instantaneously cooled to a temperature range in which the toner particles do not aggregate or coalesce. Therefore, the cooling air is cooled at a temperature of 25 ° C. or lower, preferably 15 ° C. or lower, more preferably 10 ° C. or lower. However, if the temperature is lowered more than necessary, condensation may occur depending on the conditions, and conversely, side effects occur. In such instantaneous heat treatment, the time during which the binder resin is in a molten state is very short in combination with the cooling by the cooling water in the apparatus described below, so that the particles do not adhere to each other and to the wall of the heat treatment apparatus. As a result, the stability during continuity production is excellent, the frequency of cleaning of the manufacturing apparatus can be extremely reduced, and the yield can be stably controlled at a high level.
[0033]
The suction air volume refers to air for conveying processed toner particles to the cyclone by the blower 113. Increasing the suction air volume is preferable in terms of reducing the cohesiveness of the toner particles.
[0034]
The cooling water temperature refers to the temperature of the cooling water in the cooling jackets provided in the cyclones 109 and 114 and the introduction pipe 102 ″. The cooling water temperature is 25 ° C. or less, preferably 15 ° C. or less, more preferably 10 It is below ℃.
[0035]
The following is mentioned as an example of the concrete measure for suppressing the variation of a shape with high circularity in this invention small.
(1) The amount of toner supplied into the hot air is controlled to be constant so as not to cause pulsation or the like. For this purpose, a combination of a plurality of conventional table feeders and vibration feeders is used to improve the quantitative supply capability; after supplying the toner with compressed air, the toner particles are redispersed before being supplied into the hot air. , Increase uniformity (for example, re-dispersion with secondary air, provision of a buffer unit to make the dispersion state of toner uniform, re-dispersion with a coaxial double tube nozzle, etc.);
[0036]
(2) To optimize and uniformly control the dispersion concentration of the toner when sprayed into the hot air, to supply it to the hot air in a uniform and highly dispersed state (dispersion) When supplying from a nozzle, use a nozzle with a stabilizer or the like to improve the dispersion uniformity of the toner dispersed from each nozzle); in order to make the dispersion density of the toner in the hot air uniform, the number of nozzles is , At least 3 or more, preferably 4 or more as many as possible, and arranged symmetrically with respect to the entire circumferential direction, preferably uniformly from the slit portion provided in the 360 ° circumferential area Supply toner.
[0037]
(3) The temperature distribution of the hot air in the region where the toner is processed is uniformly controlled and the flow of the hot air is controlled in a laminar flow so that uniform energy is applied to any particle. Reduce the temperature variation of the heat source that supplies the hot air; make the straight tube part before the hot air supply as long as possible in order to make the hot air state of the toner particles uniform and stable; In addition, in the configuration of the exemplary apparatus of the present invention, since the hot air and the dispersed toner are supplied in the open state, the hot air tends to diffuse in a direction in contact with the outside air. The hot air supply port is throttled as necessary; preferably, the spray angle of the nozzle is changed so that the toner particles pass near the center of the hot air where the temperature of the hot air is stable (temperature distribution is small). Set at an acute angle in the direction (e.g., 25-35 degrees) for.
[0038]
{Circle around (4)} The toner particles are fluidized to maintain a uniformly dispersed state during the heat treatment, and for that purpose, to ensure the dispersion and fluidity of the toner, 1/20 or less of the particle size of the treated toner. Preferably, various organic / inorganic fine particle flow aids of 1/50 or less are used (particularly, the average diameter of primary particles is 20 nm or less (BET specific surface area is 100 m²/ G or more) of inorganic fine particles (particularly hydrophobic silica fine particles) subjected to a hydrophobic treatment. The addition amount is preferably 0.1 to 6 parts by weight, particularly preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of the toner particles); the mixing treatment for improving the dispersion and fluidity is preferably Is present on the toner surface in an attached state that is not uniformly and strongly fixed.
[0039]
(5) In order to maintain the spacer effect between the toner particles on the toner surface even when the toner surface is heated, particles that do not soften at the processing temperature are present on the toner surface. For this purpose, preferably in (4) Add fine particles that have a larger particle size compared to the various organic / inorganic fine particles shown and that do not soften at the processing temperature (because of the presence of the main particles on the toner particle surface, In this case, the surface of the toner particles does not become a surface of only the resin component, but a spacer effect is produced between the toner particles to prevent aggregation and coalescence of the toner particles. Among them, the addition amount of the large particle is 0.3 to 5 parts by weight, preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of the toner particles).
[0040]
{Circle around (6)} The heat treatment may be carried out by the minimum necessary instantaneous heating, and then the toner particles are immediately cooled to a temperature region in which aggregation and coalescence do not occur. For this purpose, usually, after heat treatment, the outside air is introduced into the processing apparatus to instantaneously cool the toner particles to the normal temperature level. However, depending on the physical properties of the toner, aggregation and coalescence particles are likely to occur due to the influence of the outside air temperature. Therefore, it is preferable to control the temperature of the cooling air to be introduced, and the temperature is preferably 25 ° C. or less. Is cooled at 15 ° C. or lower, more preferably 10 ° C. or lower. However, if the temperature is lowered more than necessary, condensation may occur depending on the conditions, and an undesirable result is produced.
[0041]
(7) The collection of heat-treated toner should be controlled under the condition that no heat is generated. For this purpose, the heat-treated and cooled toner is preferably cooled with a chiller in order to suppress the heat generated by the piping system (particularly the rounded portion) and the cyclone normally used for collecting the toner.
[0042]
The conditions for surface treatment modification are preferably as follows.
The toner supply unit is provided with a table feeder and a vibration feeder. It is important for the feeder to provide a highly accurate and quantitative supply. It is preferable that a large amount of toner particles can be supplied to the heat treatment process online as it is in the dispersed state in the fine pulverization or classification process.
[0043]
The ejection angle is about 30 degrees, and it is preferable to introduce and treat the toner particles at an angle along the flow of the central region where the hot air temperature and the uniformity of the hot air are high as much as possible.
The amount of hot air is preferably 800 L / min or more. Increasing the amount of hot air is preferable in terms of improving the uniformity and processing capability of the heat treatment.
The dispersion air volume is appropriately about 55 L / min although it depends on other conditions. It is preferable that the amount of dispersed air is suppressed and heat treated because the dispersed state of the toner is improved and stabilized. It is usually preferable that the suction air volume be about 1200 L / min or more. Increasing the suction air volume is preferable in terms of reducing the cohesiveness of the toner particles.
[0044]
The dispersion density varies depending on the specific gravity of the toner, and the value divided by the specific gravity of each toner is 50 to 300 g / m.^Three, Preferably 50 to 200 g / m^ThreeIt is preferable to treat with.
[0045]
The treatment temperature refers to the temperature range 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 perform the treatment while reducing this temperature distribution. From the surface of the apparatus, it is preferable to supply the wind in a stabilized laminar flow state by a stabilizer or the like. In the case of the present invention, particularly in the case of a non-magnetic toner, it is preferable that the binder resin used has a sharp melting temperature. It is preferable to process in the above peak temperature range, and it is preferable to process especially in the peak temperature range of 120 to 250 degreeC or more of glass transition temperature. In a non-magnetic toner using a binder resin with a relatively wide molecular weight distribution used for oilless, it is preferable to treat in a peak temperature range of 100 ° C. to 300 ° C. or more of the glass transition temperature of the binder resin, In particular, it is preferable to perform the treatment in a peak temperature range of 150 ° C. to 280 ° C. or more of the glass transition temperature. This is because in order to improve the toner shape and surface uniformity, it is necessary to set a higher processing temperature so as to achieve the modification of the high molecular weight region of the binder resin. However, when the processing temperature is set high, coalesced particles are likely to be generated. Therefore, it is necessary to tune the fluidization process before heat treatment to a large value, or to set the dispersion concentration at the time of processing low. . The peak temperature range refers to the maximum temperature in the region where the toner contacts hot air.
[0046]
If wax is added for the purpose of improving the fixability and durability, coalesced particles are likely to be generated. To increase the sphericity, if the processing temperature is set high, coalesced particles are likely to be produced. Tuning, such as setting a large amount of fluidization treatment (particularly a fluidizing agent having a large particle size component) and setting a low dispersion concentration during processing, can provide a uniform toner that suppresses variation in shape and shape. Is important.
The residence time of the toner in the heat treatment region is set to 2 seconds or less, preferably 1 second or less. When the residence time exceeds 2 seconds, coalesced particles are likely to be generated. Moreover, it is also preferable to process several times in order to improve uniformity.
[0047]
Cooling air temperature: It is not preferable that the toner obtained by instantaneous heat treatment stays for 2 seconds or more under a temperature condition equal to or higher than the glass transition temperature of the binder resin being used. It is preferable to return to an atmosphere below the transition temperature. Therefore, the cooling air is cooled at a temperature of 25 ° C. or lower, preferably 15 ° C. or lower, more preferably 10 ° C. or lower. However, if the temperature is lowered more than necessary, condensation may occur depending on conditions, and conversely, an undesirable result is produced. Accordingly, when the instantaneous heat treatment and the cooling with cooling water in the apparatus are used in combination, the melting time of the binder resin can be shortened so that the particles do not adhere to each other and to the wall of the heat treatment apparatus. As a result, the stability during continuous production is excellent, the frequency of cleaning the manufacturing apparatus can be extremely reduced, and the yield can be stably controlled at a high level.
The cooling water temperature is preferably 25 ° C. or lower, more preferably 15 ° C. or lower, and further preferably 10 ° C. or lower.
[0048]
In order to obtain a toner having the physical properties shown in the present invention, it is preferable to carry out the above-mentioned measures alone or in combination.
[0049]
In the kneading and pulverizing method, the toner is manufactured through a raw material mixing step, a melt kneading step, a pulverizing step, and a classification step. The classification step may be performed after the instantaneous heat treatment in the present invention. At this time, it is preferable to use a pulverizer that can spheroidize particles as a pulverizer used in the pulverization step, because it becomes easy to control instantaneous heat treatment to be performed later. Examples of such an apparatus include an inomizer system (manufactured by Hosokawa Micron Corporation), a kryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), and the like. Further, by using a classification device that can spheroidize the particles to be processed as a classification device used in the classification step, it is easy to control the circularity and the like. An example of such a classifier is a teaplex classifier (manufactured by Hosokawa).
[0050]
Further, in combination with the instantaneous heat treatment, various treatments in various toner surface modification apparatuses may be combined. As these surface modification devices, surface modification using high-speed air current impact method such as hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron cosmos series (manufactured by Kawasaki Heavy Industries, Ltd.), inomizer system (manufactured by Hosokawa Micron), etc. Surface reformer using dry mechanochemical method such as equipment, mechano-fusion system (made by Hosokawa Micron), mechano mill (made by Okada Seiko Co., Ltd.), Disper Coat (made by Nisshin Engineering) Coat Mizer (made by Freund Sangyo) A surface modification apparatus using a wet coating method can be used in appropriate combination.
The toner fine particles surface-treated by heat are preferably adjusted in particle size by classification.
[0051]
As described above, when the toner particles are dispersed and sprayed in hot air and subjected to instantaneous heat treatment, the surface properties of the color toner and the oilless fixing toner are represented by the following formula [I]:
D / d50 ≧ 0.40 where D = 6 / (ρ · S) [I]
(Where D is the particle size (μ) converted from the BET specific surface area assuming that the toner shape is a sphere; d50 is the particle size equivalent to 50% of the relative weight distribution by particle size (μm); ρ is the true density (g / cm^Three); S is the BET specific surface area (m²/ G) respectively. )
The one that satisfies is obtained. Preferably, D / d50 is 0.50 or more.
[0052]
In the case of the magnetic toner, since the magnetic powder is contained inside the particle, the lower limit value of D / d50 is smaller than that without the magnetic powder, and a D / d50 ≧ 0.20 is obtained. Preferably, D / d50 is 0.25 or more.
[0053]
This D / d50 is an index indicating the presence or absence of pores on the surface or inside of the toner particles. If the toner has the above value, the toner breaks around the pores or is added as an external additive to the recesses. There is no inconvenience that silica or the like, which is a fluidizing agent, is embedded, or that convex portions are shaved and fine powder is generated.
[0054]
The BET specific surface area uses a value measured with a Flowsorb 2300 type (manufactured by Shimadzu Corporation). However, if the BET specific surface area is measured by the same measurement principle and method, it means that it must be measured by the above apparatus. do not do.
[0055]
The relative weight distribution by particle size (d50) uses the value measured by Coulter Multisizer II; manufactured by Coulter Counter, but if it is measured by the same measurement principle and method, it is measured by the above apparatus. Does not mean that it must be done.
[0056]
True density (ρ) refers to the true density of particles before adding an external additive such as silica, and is based on an air-comparing hydrometer; a value measured by Beckman, but the same measurement principle, If measured by a method, it does not mean that it must be measured by the device.
[0057]
The toner obtained as described above is provided as a developer by externally adding a fluidizing agent such as silica.
[0058]
The binder resin used in the present invention is not particularly limited, and any resin used for toner can be used in appropriate combination. Specifically, polyester resin, vinyl resin (styrene resin, acrylic resin, olefin resin, etc.), diene resin, polyester resin, epoxy resin, polyamide resin, silicone resin, phenol resin, petroleum resin, urethane resin, etc. Either resin or natural resin can be used. In particular, in order to obtain a substantially spherical toner having a uniform particle size distribution by the method of the present invention, in the case of a color toner (including black), for example, at least a glass transition temperature of 50 to 75 ° C. and a softening point of 80 to 120. In the case of an oilless fixing toner, at least a glass transition temperature of 50 to 75 ° C., a softening point of 80 to 150 ° C., and a number average molecular weight of 1000 It is preferable to use a binder resin having a weight average molecular weight / number average molecular weight of 30 to 100.
[0059]
As the polyester resin, a polyester resin having an acid value of 2 to 50 KOHmg / g, preferably 3 to 40 KOHmg / g is preferable. By using a polyester resin having such an acid value, the dispersibility of various pigments including carbon black and a charge control agent can be improved, and a toner having a sufficient charge amount can be obtained. When the acid value is less than 2 KOHmg / g, the above-described effect is reduced, and when the acid value is more than 50 KOHmg / g, the stability of the toner charge amount against environmental fluctuations, particularly humidity fluctuations, is impaired.
In the present invention, as the polyester-based resin, a polyester resin obtained by polycondensation of a polyhydric alcohol component and a polyvalent carboxylic acid component can be used.
[0060]
Among the polyhydric alcohol components, examples of the dihydric alcohol component include polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, 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, etc. Bisphenol A alkylene oxide adduct, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, , 5-pentanediol, 1,6-hexanediol 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A, and the like.
[0061]
Examples of the trivalent or higher alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol. 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. Is mentioned.
[0062]
Among the polyvalent carboxylic acid components, examples of the divalent carboxylic acid component include 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-dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, isooctenyl succinic acid, n-octyl succinic acid , Isooctyl succinic acid, anhydrides or lower alkyl esters of these acids.
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-hexanenetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4 -Cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empole trimer acid, anhydrides of these acids, lower alkyl esters and the like.
[0063]
In the present invention, as a polyester resin, a polyester resin raw material monomer, a vinyl resin raw material monomer, and a mixture of monomers that react with both resin raw material monomers are used to obtain a polyester resin in the same container. A resin obtained by performing a condensation polymerization reaction and a radical polymerization reaction for obtaining a styrene resin in parallel can also be suitably used. In addition, the monomer which reacts with the raw material monomers of both resins is, in other words, a monomer that can be used for both the condensation polymerization reaction and the radical polymerization reaction. That is, it is a monomer having a carboxy group that can undergo a condensation polymerization reaction and a vinyl group that can undergo a radical polymerization reaction, and examples thereof include fumaric acid, maleic acid, acrylic acid, and methacrylic acid.
Examples of the raw material monomer for the polyester resin include the aforementioned polyhydric alcohol component and polyvalent carboxylic acid component.
[0064]
Examples of the raw material monomer for the vinyl resin include 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, 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 Methacrylic acid alkyl esters 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 acid, isopentyl acrylate, neopentyl acrylate, 3- (methyl) butyl acrylate, hexyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, and dodecyl acrylate Esters; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid; acrylonitrile, maleic acid ester, itaconic acid ester, vinyl chloride, vinyl acetate, vinyl benzoate, vinylmethyl 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 vinyl resin include 2,2′-azobis (2,4-dimethylvaleronitrile, 2,2′-azobisisobutyronitrile, 1,1′-azobis). (Cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile and other azo or diazo polymerization initiators, benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxycarbonate, Examples thereof include peroxide-based polymerization initiators such as lauroyl peroxide.
[0065]
In the present invention, a polyester-based resin is particularly used to improve fixability and offset resistance as an oilless fixing toner, or to control glossiness of an image in a full-color toner requiring translucency. It is preferable to use two types of polyester resins having different softening points. A first polyester resin having a softening point of 95 to 120 ° C. is used to improve fixability in an oilless fixing toner, and a second polyester system having a softening point of 130 to 160 ° C. is used to improve offset resistance. Use resin. In this case, when the softening point of the first polyester resin is lower than 95 ° C., the offset resistance is lowered or the reproducibility of dots is lowered, and when it is higher than 120 ° C., the effect of improving the fixing property is insufficient. Further, if the softening point of the second polyester resin is lower than 130 ° C., the effect of improving the offset resistance is insufficient, and if it is higher than 160 ° C., the fixing property is lowered. From such a viewpoint, the softening point of the first polyester resin is more preferably 100 to 115 ° C, and the softening point of the second polyester resin is 135 to 155 ° C. The glass transition point of the first and second polyester resins is 50 to 75 ° C., preferably 55 to 70 ° C. This is because if the glass transition point is low, the heat resistance of the toner is insufficient, and if it is too high, the grindability during production is lowered and the production efficiency is lowered.
[0066]
As the first polyester-based resin, a polyester resin obtained by polycondensation of the above-described polyhydric alcohol component and polyvalent carboxylic acid component, particularly a bisphenol A alkylene oxide adduct as a main component as a polyhydric alcohol component, A polyester resin obtained by using, as a main component, at least one selected from the group consisting of terephthalic acid, fumaric acid, dodecenyl succinic acid, and Bencentricarboxylic acid as the carboxylic acid component is preferred.
[0067]
In addition, as the second polyester-based resin, a mixture of a raw material monomer for polyester resin, a raw material monomer for vinyl resin, and a bireactive monomer that reacts with the raw material monomers for both resins is used. A polyester resin obtained by performing a condensation polymerization reaction for obtaining a vinyl resin and a radical polymerization reaction for obtaining a vinyl resin in parallel is preferable from the viewpoint of improving wax dispersibility, toner toughness, fixing property, and offset resistance. . The content of the vinyl resin in the second polyester resin is 5 to 40% by weight, preferably 10 to 35% by weight. This is because if the vinyl resin content is lower than 5% by weight, the fixing strength of the toner is lowered, and if it exceeds 40% by weight, the offset resistance, the toughness of the toner is lowered, and the negative charge level is likely to be lowered. Become. When the toner contains wax, if the vinyl resin content is less than 5% by weight, the dispersibility of the polyethylene wax decreases, and if it exceeds 40% by weight, the dispersibility of the polypropylene wax tends to decrease. is there.
[0068]
The weight ratio of the first polyester resin to the second polyester resin is preferably 7: 3 to 2: 8, more preferably 6: 4 to 3: 7. By using the first polyester resin and the second polyester resin in such a range, the toner has a small spread due to crushing at the time of fixing, and has excellent dot reproducibility, and also has excellent low temperature fixability and low speed and high speed. In such an image forming apparatus, excellent fixability can be secured. In addition, excellent dot reproducibility can be maintained even during double-sided image formation (when passing through the fixing machine twice). When the ratio of the first polyester resin is less than the above range, the low-temperature fixability becomes insufficient and a wide fixability cannot be secured. Further, when the ratio of the second polyester resin is less than the above range, the offset resistance is lowered, and the toner is crushed at the time of fixing, and the dot reproducibility tends to be lowered.
[0069]
For full color, which requires translucency, a sharp melt type resin having a sharp molecular weight distribution has been used, and a glossy pictorial image was reproduced by using such a resin. However, in recent years, there are cases in which images with reduced glossiness are required for normal office colors and the like. Such a requirement can be achieved, for example, by expanding the molecular weight distribution of the resin to the polymer side. Mata, one of its specific measures, can be achieved by using a combination of two or more resins having different tocite molecular weights. The final resin properties are a glass transition temperature of 50 to 75 ° C., a softening point of 80 to 120. It can be suitably used as long as it has a weight average molecular weight / number average molecular weight of 2-20. When the glossiness is lowered, the value of weight average molecular weight / number average molecular weight is set to 4 or more, and the melt viscosity curve can be tilted to widen the gloss control area with respect to the fixing temperature. .
[0070]
In addition, epoxy resins can also be preferably used particularly in full-color toners. As the epoxy resin used in the present invention, a polycondensate of bisphenol A and epichlorohydrin can be suitably used. For example, Epomic R362, R364, R365, R367, R369 (manufactured by Mitsui Petrochemical Industry Co., Ltd.), Epotot YD-011, YD-012, YD-014, YD-904, YD-017 (manufactured by Toto Kasei Co., Ltd.), Commercially available products such as Epicoat 1002, 1004 and 1007 (manufactured by Shell Chemical Co., Ltd.) can also be used.
[0071]
In the present invention, the softening point of the resin is a flow tester (CFT-500: manufactured by Shimadzu Corporation), the pores of the die (diameter 1 mm, length 1 mm), and pressure 20 kg / cm.²1cm under the condition of heating rate 6 ℃ / min^ThreeThe temperature corresponding to ½ of the height of the outflow end point from the outflow start point when the sample was melted out was taken as the softening point. The glass transition point was measured between 20 and 120 ° C. using a differential scanning calorimeter (DSC-200: manufactured by Seiko Electronics Co., Ltd.) with a reference of alumina and a 10 mg sample at a heating rate of 10 ° C./min. The shoulder value of the main endothermic peak was taken as the glass transition point. The acid value was determined by dissolving a 10 mg sample in 50 ml of toluene and titrating with a standardized N / 10 potassium hydroxide / alcohol solution using a 0.1% mixed indicator of bromthymol blue and phenol red. / 10 A value calculated from consumption of potassium hydroxide / alcohol solution. Further, the molecular weight (number average molecular weight, weight average molecular weight) is a value calculated in terms of styrene using a gel permeation chromatography (GPC) method.
[0072]
Furthermore, the toner of the present invention may contain a wax in order to improve characteristics such as offset resistance. Examples of such wax include polyethylene wax, polypropylene wax, carnauba wax, rice wax, sazol wax, montan ester wax, and Fischer-Tropsch wax. Thus, when the wax is contained in the toner, the content can be adjusted to 0.5 to 5 parts by weight with respect to 100 parts by weight of the binder resin in order to obtain the effect of addition without causing problems such as filming. Is preferable.
[0073]
From the viewpoint of improving the offset resistance, it is preferable to contain polypropylene wax, and smearing (the image is rubbed with a roller when feeding paper with an image already formed on one side during automatic document feeding or duplex copying). From the viewpoint of improving the phenomenon of image quality deterioration such as bleeding and smudges in the image, it is preferable to contain polyethylene wax. Particularly preferred polypropylene waxes from the above viewpoint are polypropylene waxes having a melt viscosity at 160 ° C. of 50 to 300 cps, a softening point of 130 to 160 ° C. and an acid value of 1 to 20 KOH mg / g, and particularly preferred polyethylene waxes are 160 A polyethylene wax having a melt viscosity of 1000 to 8000 cps and a softening point of 130 to 150 ° C. That is, the polypropylene wax having the melt viscosity, softening point, and acid value has excellent dispersibility in the binder resin, and can improve the offset resistance without causing a problem due to the free wax. In particular, when a polyester resin is used as the binder resin, it is preferable to use an oxidized wax.
[0074]
Examples of the oxidized wax include polyolefin-based oxidized wax, carnauba wax, monta wax, rice wax, and Fischer-Tropsch wax.
[0075]
Polypropylene wax, which is a polyolefin wax, has a defect that lowers the fluidity of the toner due to low hardness of low molecular weight polypropylene. To improve this defect, it is modified with carboxylic acid or acid anhydride. Is preferred. In particular, a modified polypropylene resin obtained by modifying a low molecular weight polypropylene resin with one or more acid monomers selected from the group consisting of (meth) acrylic acid, maleic acid, and maleic anhydride can be suitably used. The modified polypropylene is, for example, grafted or added to a polypropylene resin with one or more acid monomers selected from the group consisting of (meth) acrylic acid, maleic acid and maleic anhydride in the presence or absence of a peroxide catalyst. Can be obtained. When a modified polypropylene is used, the acid value is 0.5 to 30 KOH mg / g, preferably 1 to 20 KOH mg / g.
[0076]
As the above-mentioned oxidized polypropylene wax, commercially available products include biscol 200TS (softening point 140 ° C., acid value 3.5), biscol 100TS (softening point 140 ° C., acid value 3.5) manufactured by Sanyo Chemical Industries, Ltd. Viscol 110TS (softening point 140 ° C., acid value 3.5) can be used.
[0077]
Among those commercially available as oxidized polyethylene, Sanwa Kasei Kogyo Sun Wax E300 (softening point 103.5 ° C., acid value 22), Sun Wax E250P (softening point 103.5 ° C., acid value 19.5) High wax 4053E (softening point 145 ° C., acid value 25), 405 MP (softening point 128 ° C., acid value 1.0), 310 MP (softening point 122 ° C., acid value 1.0), manufactured by Mitsui Petrochemical Industries, Ltd. 320MP (softening point 114 ° C, acid value 1.0), 210MP (softening point 118 ° C, acid value 1.0), 220MP (softening point 113 ° C, acid value 1.0), 220MP (softening point 113 ° C, acid 1.0), 4051E (softening point 120 ° C, acid value 12), 4052E (softening point 115 ° C, acid value 20), 4202E (softening point 107 ° C, acid value 17), 2203A (softening point 111 ° C, acid 30) can be used.
[0078]
When carnauba wax is used, it is preferably microcrystalline and has an acid value of 0.5 to 10 KOH mg / g, preferably 1 to 6 KOH mg / g.
[0079]
The montan wax generally refers to a montan ester wax purified from a mineral and is microcrystalline like the carnauba wax, and has an acid value of 1 to 20, preferably 3 to 15.
[0080]
Rice wax is obtained by air-oxidizing rice bran wax and preferably has an acid value of 5 to 30 KOH mg / g.
[0081]
Fier-Tropsch wax is a wax produced as a by-product when synthetic petroleum is produced from coal by a hydrocarbon synthesis method, and is commercially available, for example, under the trade name “Sazol Wax” manufactured by Sazol. In addition to this, Fischer-Tropsch wax using natural gas as a starting material can be suitably used because it has few low molecular weight components and is excellent in heat resistance when used in toners.
[0082]
The acid value of Fischer-Tropsch wax can be 0.5 to 30 KOH mg / g, and among the sazol waxes, particularly those of the oxidation type having an acid value of 3 to 30 KOH mg / g (trade name, Sac. Zole wax A1, A2, etc.) can be preferably used. The polyethylene wax having the above-mentioned melt viscosity and softening point is also excellent in dispersibility in the binder resin, and achieves improved smearing by reducing the coefficient of friction on the surface of the fixed image without causing problems due to free wax. Can do. The melt viscosity of the wax was measured with a Brookfield viscometer.
[0083]
Also, known pigments and dyes are used as colorants for full-color toners. 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. And CI Pigment Blue 15: 3. Further, in the black toner, in addition to various carbon blacks, activated carbon, and titanium black, a part or all of the colorant can be replaced with a magnetic material. As such a magnetic material, for example, known magnetic fine particles such as ferrite, magnetite, and iron can be used. The average particle diameter of the magnetic particles is preferably 1 μm or less, particularly preferably 0.5 μm or less in order to obtain dispersibility during production. When added from the viewpoint of preventing scattering while having the characteristics as a non-magnetic toner, the addition amount is 0.5 to 10 parts by weight, preferably 0.5 to 8 parts by weight based on 100 parts by weight of the binder resin. Part by weight, more preferably 1 to 5 parts by weight. When the addition amount exceeds 10 parts by weight, the magnetic restraint force of the developer carrying member (built-in magnet roller) with respect to the toner becomes strong, and the developability deteriorates.
[0084]
When used as a magnetic toner, the magnetic material is preferably 20 to 60 parts by weight with respect to 100 parts by weight of the binder resin. When the addition amount is 20 parts by weight or less, toner scattering tends to increase. When the addition amount exceeds 60 parts by weight, the toner charge amount cannot be secured stably, and the image quality is deteriorated.
[0085]
In the toner of the present invention, additives such as a charge control agent and a release agent may be added to the binder resin depending on the purpose. For example, the charge control agent may be a fluorine-based surfactant, a salicylic acid metal complex, a metal-containing dye such as an azo metal compound, a polymer acid such as a copolymer containing maleic acid as a monomer component, or a quaternary. An ammonium salt, an azine dye such as nigrosine, carbon black or the like can be added. Magnetic powder or the like may be added to the toner of the present invention as necessary.
[0086]
Furthermore, it is preferable that various organic / inorganic fine particles are added to the toner of the present invention as a fluidity adjusting agent before surface modification and / or after toner particles are adjusted. As inorganic fine particles, 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, diamond carbon lactam, etc. Various nitrides such as boron nitride, titanium nitride and 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, calcium stearate Zinc stearate, various metal soaps such as magnesium stearate, talc, various non-magnetic inorganic fine particles of bentonite can be used alone or in combination. Especially for inorganic fine particles such as silica, titanium oxide, alumina, and zinc oxide, conventionally used hydrophobizing agents such as silane coupling agents, titanate coupling agents, silicone oils, and silicone varnishes, and fluorine-based ones. It is preferable that the surface treatment is carried out by a known method with a treatment agent such as a silane coupling agent, a fluorine-based silicone oil, a coupling agent having an amino group or a quaternary aluminum base, or a modified silicone oil.
[0087]
As organic fine particles, granulated by wet polymerization methods such as emulsion polymerization method, soap-free emulsion polymerization method, non-aqueous dispersion polymerization method, gas phase method, etc., styrene, (meth) acrylic, benzoguanamine, melamine, Teflon, silicon Various organic fine particles such as polyethylene and polypropylene can also be used. The organic fine particles also have a function as a cleaning aid.
[0088]
The relatively large diameter inorganic fine particles such as metal titanate and various organic fine particles may or may not be hydrophobized. The amount of the fluidizing agent added is 0.1 to 6 parts by weight, preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the developer particles as the amount added before the heat treatment. Further, the external addition treatment after the heat treatment is added in an amount of 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of the developer particles. It is preferable to use after adjusting the addition amount.
[0089]
The toner of the present invention is obtained by mixing, kneading, pulverizing, and classifying the above-described binder resin, colorant, and other desired additives by conventional methods to obtain particles having a desired particle size. The particles thus obtained are subjected to instantaneous heat treatment.
[0090]
The particle size is 4 to 10 μm, preferably 5 to 9 μm. The particle size distribution of the particles obtained at this stage hardly changes even after the instantaneous heat treatment.
[0091]
The classification step may be performed after the instantaneous heat treatment in the present invention. At this time, it is preferable to use a pulverizer that can spheroidize particles as a pulverizer used in the pulverization step, because it becomes easy to control instantaneous heat treatment to be performed later. Examples of such an apparatus include an inomizer system (manufactured by Hosokawa Micron), a kryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), and the like. Further, by using a classification device that can spheroidize the particles to be processed as a classification device used in the classification step, it is easy to control the circularity and the like. An example of such a classifier is a teaplex type classifier (manufactured by Hosokawa Micron).
[0092]
Further, in combination with the instantaneous heat treatment shown in the present invention, it may be combined with various treatments in various developer surface modifying apparatuses. These surface modification devices include surface modification using a high-speed air current impact method such as a hybridization system (manufactured by Nara Machinery Co., Ltd.), a kryptron cosmos system (manufactured by Kawasaki Heavy Industries, Ltd.), an inomizer system (manufactured by Hosokawa Micron). Surface reformer using a dry mechanochemical method such as a mechanical device, mechano-fusion system (made by Hosokawa Micron), mechano-mill (made by Okada Seiko Co., Ltd.), Disper Coat (made by Nisshin Engineering), Coat Mizer (made by Freund Sangyo Co., Ltd.) The surface modification apparatus to which the wet coating method is applied can be used in appropriate combination.
[0093]
According to the present invention, by performing an instantaneous heat treatment, the shape of the toner particles obtained by the kneading-pulverization method is controlled to a spherical and uniform shape, and furthermore, the pores on the surface of the toner are reduced, Smoothness can be increased. As a result, the uniformity of charging and the image performance are excellent, and the specific particle size and shape component in the developer, and the selective development such that the toner having a specific charge amount is consumed first does not occur, A toner that achieves stable image performance over a long period of time can be provided.
[0094]
In addition, the toner according to the present invention is mainly composed of a binder resin having a low softening point suitable for recent high demands for high image quality, low consumption (high color material filling type), and an energy saving fixing method, and high color material number filling. Even in the small particle size toner, the adhesion to the toner carrier (carrier, developing sleeve, developing roller, etc.), the photosensitive member, and the transfer member is optimized, and the mobility is excellent. Furthermore, it has excellent fluidity, improved charging uniformity, and stable durability characteristics over a long period of time. In addition, in the magnetic toner, by performing such instantaneous heat treatment, the binder resin of the magnetic particles is melted and spheroidized, the magnetic powder exposed on the surface disappears, and the free fine powder is removed from the surface of the magnetic particles. To be fixed.
[0095]
【Example】
Examples of resin production
Production example of polyester resin A
4.0 mol of polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as “PO”), polyoxyethylene (2,0) -2,2-bis (4- Hydroxyphenyl) propane (hereinafter referred to as “EO”) 6.0 mol, terephthalic acid (hereinafter referred to as “TPA”) 9.0 mol and dibutyltin oxide as a catalyst were placed in a glass four-necked flask, and a thermometer, A stainless stir bar, a flow-down condenser, and a nitrogen introduction tube were attached, and the reaction was carried out while stirring and heating in a nitrogen stream in a mantle heater. The progress of this reaction was followed by measuring the acid value. When the predetermined acid value was reached, the reaction was terminated and cooled to room temperature to obtain polyester resin A. The obtained polyester resin was roughly crushed to 1 mm or less and used in the production of the following toner.
In addition, the physical property of the polyester resin obtained here is number average molecular weight (Mn): 3300, weight average molecular weight (Mw) / number average molecular weight (Mn): 4.2, glass transition temperature (Tg): 4.2. ° C., softening point (Tm): 110.3 ° C., acid value: 3.3, and hydroxyl value: 28.1.
[0096]
Production example of polyester resin H (L)
A glass four-necked flask equipped with a thermometer, a stirrer, a flow-down condenser and a nitrogen inlet tube was charged with polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2 , 2) -2,2-bis (4-hydroxyphenyl) propane, isododecenyl succinic anhydride, terephthalic acid and fumaric acid adjusted to a weight ratio of 82: 77: 16: 32: 30, dibutyltin oxide as a polymerization initiator Put together. This was reacted in a mantle heater with stirring at 220 ° C. in a nitrogen atmosphere. The obtained polyester resin L had a softening point of 110 ° C., a glass transition point of 60 ° C., and an acid value of 17.5 KOH mg / g.
[0097]
Example of production of polyester resin I (H)
Styrene and 2-ethylhexyl acrylate were adjusted to a weight ratio of 17: 3.2, and placed in a dropping funnel together with digamyl peroxide as a polymerization initiator. On the other hand, a glass four-necked flask equipped with a thermometer, a stirrer, a flow-down condenser, and a nitrogen inlet tube was added to polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene. (2,2) -2,2-bis (4-hydroxyphenyl) propane, isododecenyl succinic anhydride, terephthalic acid, 1,2,4-benzenetricarboxylic anhydride and acrylic acid in a weight ratio of 42: 11: 11: 11 It adjusted to 8: 1 and it put with the dibutyltin oxide which is a polymerization initiator. While stirring this at 135 ° C. in a mantle heater in a nitrogen atmosphere, styrene or the like was dropped from the dropping funnel, and then the temperature was raised and reacted at 230 ° C. The obtained polyester resin H had a softening point of 150 ° C., a glass transition point of 62 ° C., and an acid value of 24.5 KOH mg / g.
[0098]
Manufacture of pigment masterbatch
The pigments used for the production of full color toners below are the thermoplastic resin used in the examples and C.I. I. Pigment Yellow 180 (manufactured by Clariant), C.I. I. Pigment Blue 15-3 (Dainippon Ink Chemical Co., Ltd.), C.I. I. Pigment Red184 (manufactured by Dainippon Ink & Chemicals, Inc.) 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 yellow, cyan, and magenta pigment master batches having a pigment content of 30 wt%.
[0099]
Example of toner production
Full color toner
Production Examples Y-1 to Y-2
1. 93.3 parts by weight of the polyester resin A obtained in the resin production example, 13.3 parts by weight of a yellow masterbatch and a zinc complex of salicylic acid as a charge control agent (E-84: manufactured by Orient Chemical Industries) 0 parts by weight, oxidized low molecular weight polypropylene (100TS: manufactured by Sanyo Kasei Co., Ltd .; softening point 140 ° C., acid value 3.5) was sufficiently mixed with a Henschel mixer, and then a twin-screw extrusion kneader (PCM-30: Ikekai Tekko Co., Ltd.) The product from which the discharge part was removed was melt-kneaded and then cooled. The obtained kneaded material was rolled to a thickness of 2 mm with a cooling press roller, cooled with a cooling belt, and then roughly pulverized with a feather mill. Thereafter, the mixture is pulverized to an average particle size of 10 to 12 μm with a mechanical pulverizer (KTM: Kawasaki Heavy Industries, Ltd.) and further crushed to an average particle size of 6.8 μm with a jet pulverizer (IDS: manufactured by Nippon Pneumatic Industrial Co., Ltd.) After powder classification, fine powder classification is performed using a rotor type classifier (Teplex type classifier type: 100ATP: manufactured by Hosokawa Micron Co., Ltd.). Volume average particle diameter is 7.2 μm, twice volume average particle diameter (D) (2D ) Yellow toner particles (Y-1) having a weight percentage of 0.1% and a volume percentage of 1/3 (D / 3) or less of the volume average particle size of 12.1% were obtained. In addition, the average circularity of the toner particles (Y-1) is 0.946, and the standard deviation of the circularity is 0.043.
With respect to 100 parts by weight of the toner particles (Y-1), 0.5 part by weight of hydrophobic silica (TS-500: manufactured by Cabozil) and hexamethylene di of hydrophobic silica (AEROSIL 90G; manufactured by Nippon Aerosil Co., Ltd.) Silazane-treated product: 1.0 part by weight of BET specific surface area 65 m2 / g, pH 6.0, hydrophobization degree 95%) was added and mixed with a Henschel mixer (peripheral speed 40 m / sec, 60 seconds), and then FIG. And the surface modification by heat was performed under the following conditions using the apparatus shown in FIG. 2 to obtain yellow toner particles (Y-2).
[0100]
Conditions for surface modification treatment
Developer supply unit; table feeder + vibration feeder
Dispersing nozzles: 4 (symmetrical arrangement of 90 degrees for each circumference)
Ejection angle: 30 degrees
Hot air flow rate: 800L / min
Dispersed air volume: 55 L / min
Suction air volume: -1200L / min
Dispersion concentration: 100 g / m3
Processing temperature: 250 ° C
Residence time: 0.5 seconds
Cooling air temperature: 15 ° C
Cooling water temperature: 10 ° C
[0101]
Production Examples C-1 and M-2
Toner particles C-1 and M-2 and M-1 and M-2 were obtained by the same composition method as Y-1 and 2, respectively, except that the pigment master batches were changed to those of cyan and magenta pigments, respectively.
[0102]
Production Examples Y-3 to Y-5
In Toner Production Example Y-2, yellow toner particles (Y-3 to Y-5) were obtained by the same method and composition except that the temperature condition of the heat treatment was changed to 150, 200 ° C. and 300 ° C.
[0103]
Production example C-3~ 5, M-3~ 5
In the production of toner particles (Y-3 to 5), toner particles (C-3 to 5, M-3) were prepared by the same composition and method except that the master batch of the pigment was changed from yellow to cyan and magenta. To 5).
[0104]
Production example Y-6
To 100 parts by weight of the toner particles (Y-1), 1.0 part by weight of hydrophobic silica (RX200; manufactured by Nippon Aerosil Co., Ltd .; BET specific surface area 140 m 2 / g, pH 7.0) is added and ( After the mixing treatment (peripheral speed: 40 m / sec, 180 seconds), surface modification by heat was performed under the following conditions using the apparatus shown in FIGS. 1 and 2 to obtain yellow toner particles (Y-6).
Conditions for surface modification treatment
Developer supply section; table feeder
Dispersion nozzle: 2 (symmetrical arrangement with respect to the entire circumference)
Ejection angle: 45 degrees
Hot air flow rate: 620 L / min
Dispersed air volume: 68 L / min
Suction air volume: -900 L / min
Dispersion concentration: 150 g / m3
Processing temperature: 250 ° C
Residence time: 0.5 seconds
Cooling air temperature: 30 ° C
Cooling water temperature: 20 ° C
[0105]
Production Examples Y-7 to Y-9
In toner production example Y-6, yellow toner particles (Y-7 to Y-9) were obtained by the same method and composition except that the temperature condition of the heat treatment was changed to 150, 200 ° C., and 300 ° C.
[0106]
Production example Y-10
With respect to 100 parts by weight of the resin A, 15 parts by weight of the pigment, 1 part by weight of the boron compound represented by Compound 1 and 400 parts by weight of toluene are mixed and dissolved and dispersed for 30 minutes using an ultrasonic homogenizer (output 400 μA). Thus, a colored resin solution was prepared.
On the other hand, an aqueous dispersion was prepared by dissolving 0.1 part by weight of sodium lauryl sulfate (manufactured by Wako Pure Chemical Industries, Ltd.) in 1000 parts by weight of an aqueous solution containing 4% by weight of calcium hydroxide phosphate as a dispersion stabilizer. While 100 parts by weight of the aqueous dispersion is being stirred at 4200 rpm by a TK auto homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), 50 parts by weight of the colored resin solution is dropped, and the droplets of the colored resin solution are dispersed in water. It was suspended in the liquid. This suspension was allowed to stand for 5 hours under conditions of 60 ° C. and 100 mmHg to remove toluene from the droplets and precipitate colored resin particles. Next, calcium hydroxide phosphate was dissolved with concentrated sulfuric acid, and then filtration and washing were repeated. Thereafter, the colorant particles were dried at 80 ° C. with a slurry drying apparatus (Dispercoat: manufactured by Nissin Engineering Co., Ltd.) to obtain a yellow toner (Y-10).
[0107]
Production Examples C-6 and M-6
In the Y-6 toner, C-6 and M-6 toners were obtained in the same manner as in the Y-6 toner production method except that the pigment master batch was changed from yellow to cyan and magenta, respectively.
Production Examples C-7-9 and M-7-9
Toner particles C-7 to 9 and M-7 to 9 were obtained by the same composition method as in toner production examples Y-7 to 9 except that the pigment master batches were changed to those of cyan and magenta pigments, respectively.
Production Examples C-10 and M-10
C-10 and M-10 were obtained in the same manner as in Y-10 except that cyan and magenta were used in place of Pigment Yellow 180, respectively.
[0108]
Black toner for oilless fixing
Production Example Bk-1
40 parts by weight of polyester resin H (L form), 60 parts by weight of polyester resin I (H form), polyethylene wax (800P; manufactured by Mitsui Petrochemical Co., Ltd .; melt viscosity at 160 ° C .: 5400 cps; softening point: 140 ° C.) 2 parts by weight, polypropylene wax (TS-200; manufactured by Sanyo Chemical Industries Co., Ltd .; melt viscosity at 160 ° C. 120 cps; softening point 145 ° C .; acid value 3.5 KOH mg / g), acidic carbon black (Mogal L; Cabot Corporation) PH 2.5; average primary particle size 24 nm) 8 parts by weight and negative charge control agent represented by the following formula: 2 parts by weight;
[Chemical 1]

Are mixed thoroughly with a Henschel mixer, melt-kneaded with a twin-screw extruder kneader, cooled, coarsely pulverized with a hammer mill, finely pulverized with a jet pulverizer, classified, and toner particles having a volume average particle size of 7.0 μm Bk-1 was obtained.
[0109]
Production Example Bk-2 ~ 9
The toner particles obtained in Toner Production Example Bk-1 were used and fluidized before heat treatment as in Y-2 to 5, and the temperature level of heat treatment was changed to 270, 170, 220, 320 ° C. Obtained toner particles Bk-2 to 5 under the same heat treatment conditions. Moreover, according to the manufacturing method of Y-6-9, the heat processing temperature was set to 270, 170, 220, and 320 degreeC, respectively, and particle | grains Bk-6-9 were obtained.
[0110]
Production example Bk-10
Styrene 60 parts by weight, n-butyl methacrylate 35 parts by weight, methacrylic acid 5 parts by weight, 2-2 azobis (2,4-dimethylvaleronitrile) 0.5 part by weight, low molecular weight polypropylene (Biscol 660P; manufactured by Sanyo Chemical Industries) 3 parts by weight, 8 parts by weight of carbon black (MA # 8; manufactured by Mitsubishi Chemical Corporation) and chromium complex (Eisenspiron Black TRH; manufactured by Hodogaya Chemical Co., Ltd.) were mixed with a sand stirrer to prepare a polymerization composition. This polymerization composition was subjected to a polymerization reaction at 60 ° C. for 6 hours while stirring at a rotation speed of 4300 rpm using a stirrer TK auto homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) in an aqueous gum arabic solution having a concentration of 3% by weight. Spherical particles having a diameter of 6.0 μm were obtained. Filtration / washing of the spherical particles was repeated three times, and then the filtrate was air-dried in an environment of 35 ° C. and 30% RH to obtain toner particles Bk-10.
To these toner particles, 0.5% by weight of hydrophobic silica fine particles having a BET specific surface area of 140 m 2 / g (R-972; manufactured by Nippon Aerosil Co., Ltd.) and medium diameter of strontium titanate fine particles (particle size: 350 nm, BET specific surface area: 9 m 2 / g) 0.5% by weight was added and mixed with a Henschel mixer for 3 minutes at a peripheral speed of 40 m / sec, and then sieved with a sieve having an aperture of 106 μm to prepare a toner for evaluation.
[0111]
Various physical property evaluation methods
・ Measuring method of glass transition point Tg of resin
Using a differential scanning calorimeter (DSC-200: manufactured by Seiko Electronics Co., Ltd.), the reference is alumina, and a 10 mg sample is measured between 20 and 120 ° C. at a temperature increase rate of 10 ° C./min. Was the glass transition point.
[0112]
・ Measurement method of softening point Tm of resin
Using a flow tester (CFT-500: manufactured by Shimadzu Corporation), a 1 cm 2 sample was melted under the conditions of a fine pore of the die (diameter 1 mm, length 1 mm), pressurization 20 kg / cm 2, and heating rate 6 ° C./min. The temperature corresponding to ½ of the height of the outflow end point from the outflow start point at the time of outflow was taken as the softening point.
The molecular weight was determined by polystyrene conversion using gel permeation chromatography (807-IT type; manufactured by JASCO Corporation) using tetrahydrofuran as a carrier solvent.
[0113]
The acid value was determined by dissolving a 10 mg sample in 50 ml of toluene and titrating with a pre-standardized N / 10 potassium hydroxide / alcohol solution using 0.1% mixed indicator of bromthymol blue and phenol red. / 10 A value calculated from consumption of potassium hydroxide / alcohol solution.
[0114]
The hydroxy acid value was expressed in mg of potassium hydroxide required for treating a weighed sample with acetic anhydride, hydrolyzing the obtained acetyl compound, and neutralizing liberated acetic acid.
[0115]
The degree of hydrophobicity is obtained by adding 50 ml of pure water to a 200 ml beaker and adding 0.2 g of inorganic fine particles such as silica. While stirring the beaker, methanol dehydrated with anhydrous sodium sulfate is added from the burette, and the degree of hydrophobicity is calculated from the amount of methanol required using the point where silica or the like is almost not observed on the liquid surface as the end point, using the following formula.
Hydrophobicity (%) = C / (50 + C) × 100
In the formula, C represents the amount of methanol used (ml).
[0116]
The volume average particle diameter and circularity are expressed as (peripheral length of equivalent circle / perimeter of particle projection image), and using a flow type particle image analyzer (FPIA-2000: manufactured by Toago Medical Electronics Co., Ltd.) It was measured.
[0117]
The evaluation of the toner particle diameter on the sleeve was made by evaluating the difference in the toner particle diameter (average particle diameter & number% of fine powder component) in the hopper.
○: Within 10% difference
Δ: A difference of 10 to 20% is observed.
X: Causes particle size selection of 20% or more
[0118]
Toner performance evaluation
The following items were evaluated for the full-color developing toners selected in the above-mentioned examples and comparative examples. The evaluation was performed under an H / H environment (30 ° C./85% RH) and an L / L environment (10 ° C./15% RH). In Example 5 and Comparative Example 3, after performing an initial evaluation in a predetermined print pattern under H / H and L / L environments as in Examples 1 to 4 and Comparative Examples 1 and 2, Furthermore, the evaluation was performed after continuous copying of 3000 sheets using a print pattern having a B / W ratio of 6% for each color under an N / N environment (25 ° C./50% RH). In the evaluation method after continuous copying of 3000 sheets in Example 5 and Comparative Example 3, the evaluation was performed in an N / N environment, the evaluation was performed after copying 3000 sheets, and a print pattern of 6% for each color was used. Except this, it is the same as the following evaluation method. For evaluation, Color Page Pro TMPS (manufactured by Minolta Co., Ltd.) was used (however, the cleaning method was changed to the brush cleaning method).
[0119]
Hollow
The above donor for full color toner development is loaded into a full color image forming apparatus (manufactured by Minolta Co., Ltd.), a full color image (general pattern) is copied by overprinting four colors, and a full color copy image after copying 10 sheets is ranked as follows. Evaluation was made according to the attachment. The four types of toner are loaded in the four developing devices so that the layer formation order on the intermediate transfer belt is Y, M, C, and Bk from the bottom.
○: No void occurred on the copied image.
Δ: Slight hollowing occurred on the copied image, but there was no practical problem.
X: Many hollows occurred on the copied image, and there was a problem in practical use.
[0120]
Spatter
The full-color developing toner was loaded into the full-color image forming apparatus, a full-color image (general pattern) was copied by four-color overprinting, and the copied images after 10 copies were evaluated according to the following ranking. The four types of toner are loaded in the four developing devices so that the layer formation order on the intermediate transfer belt is Y, M, C, and Bk from the bottom.
○: No toner scattering was observed around the line copy image.
Δ: Toner scattering was recognized around the line copy image, but there was no practical problem.
X: A lot of toner scattering was recognized around the copied image, which was recognized as blurring and had a problem in practical use.
[0121]
Fog
The full-color developing toner is loaded into the full-color image forming apparatus, and 10 copies of a character pattern image having a B / W ratio of 30% are continuously copied by four-color overprinting. Was evaluated according to the ranking. The four types of toner are loaded in the four developing devices so that the layer formation order on the intermediate transfer belt is Y, M, C, and Bk from the bottom.
○: Fog was hardly recognized.
Δ: Some fogging was observed, but there was no practical problem.
X: The fog was present over the entire surface, and there was a problem in practical use.
[0122]
Transcription
The full-color developing toner is loaded into the full-color image forming apparatus, a solid pattern of a single color image is copied, and from the ratio of the adhesion amount on the paper to the toner adhesion amount on the photosensitive drum in the tenth copying process, Evaluation was made according to the ranking.
○: 80% or more
Δ: 70 to less than 80%
X: Less than 70%
[0123]
Dot reproducibility
A 2-dot halftone image is drawn at 600 dpi, and the dots are observed one by one with a magnifying glass (50x). The dots are reproduced one by one. Evaluated as x when there is a lot of variation in the size of the dots, and when each of the 2 dots is missing or stuck, and is not fully reproduced as a dot did.
[0124]
Line reproducibility
A 2-dot line image was drawn at 600 dpi, and the fluctuation of the line width and the scattered toner around the line image were observed with a magnifying glass (50 times).
○: Line width variation and scattering toner are both small,
Δ: Either one is inferior,
X: Both are inferior.
[0125]
Image lines:
After passing 10 sheets at B / W of 30%, an image of B / W of 100% was printed out, and the presence or absence of streak noise was evaluated.
○: No image streak
Δ: Some image streaks occurred, but no problem in practical use.
X: Image streak generation, practically problematic.
[0126]
Followability
10 sheets with B / W of 30%, after passing through, printed out an image of 100% B / W and evaluated the density unevenness.
○: No concentration unevenness
Δ: Some unevenness in density occurred, but no problem in practical use.
X: Concentration unevenness occurs, and there are practical problems.
[0127]
Toner particle size on sleeve:
Evaluation was based on the difference in the toner particle size (average particle size and number% of fine powder component) in the hopper.
○: The difference is within 10%.
(Triangle | delta): The difference of 10-20% is recognized.
X: Particle size selection of 20% or more occurred.
[0128]
The characteristic numbers of the toner are shown in Tables 1 and 2, and the evaluation results are shown in Tables 3 and 4.
[Table 1]

[0129]
[Table 2]

[0130]
[Table 3]

[0131]
[Table 4]

[0132]
【The invention's effect】
In the toner of the present invention, the charge amount of the small-diameter toner in the toner decreases, preferential uptake on the developing sleeve can be reduced, and the small-diameter toner is more easily separated from the developing sleeve than the conventional one, regardless of the particle size. Uniform development could be achieved, and furthermore, strength sufficient to withstand stress when passing between the developing sleeve and the regulating member could be provided. These comprehensive actions make it possible to maintain stable image quality over a long period of time.
[Brief description of the drawings]
FIG. 1 is a schematic view of an apparatus for surface modification treatment with hot air.
FIG. 2 is a schematic horizontal sectional view of a sample injection chamber of the apparatus of FIG.
[Explanation of symbols]
101 Hot air generator
102, 102 ', 102 "inlet tube
103 Sample injection nozzle
104 Metering machine
105 Toner particles
106 Hot air injection nozzle
107 Sample injection chamber
108 Cooling air introduction part
109 Cyclone
111 Product tank
112 Bug Filter
113 Blower

Claims (2)

A one-component toner used for electrostatic image development that develops an electrostatic latent image using a toner thin layer obtained by instantaneous heat treatment in which the heat treatment area is 2 seconds or less, and the toner has a volume average particle diameter Dm of 4 An electrostatic charge image having a relationship of Es> 1.001 Em, where Es is an average circularity of a toner component having an average circularity Em of 0.96 to 1.00 and Dm / 2 or less. One component toner for development.   The electrostatic image developing toner according to claim 1, wherein a standard deviation is 0.040 or less.

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