JP4032604B2 - Toner for developing electrostatic image and image forming method - Google Patents

Description

【０１９２】
【表２】

【０１９３】
次に、Ｂｋ着色粒子１／Ｙ着色粒子１／Ｍ着色粒子１／Ｃ着色粒子１〜Ｂｋ着色粒子１１／Ｙ着色粒子１１／Ｍ着色粒子１１／Ｃ着色粒子１１の各々に、外添剤を添加して対応する各トナー１〜１２を作製した。
【０１９４】
【表３】

【０１９５】
【表４】

【０１９６】
＊チタン酸スロトンチウム１：数平均一次粒子径＝３５０ｎｍ
＊チタン酸スロトンチウム２：数平均一次粒子径＝１２５ｎｍ
＊チタン酸スロトンチウム３：数平均一次粒子径＝４００ｎｍ
＊シリカ１：ジクロロジメチルシラン処理された数平均一次粒子径が１２ｎｍの疎水性シリカ（疎水化度＝６２）
〔現像剤の製造〕
Ｂｋトナー１／Ｙトナー１／Ｍトナー１／Ｃトナー１〜Ｂｋトナー１２／Ｙトナー１２／Ｍトナー１２／Ｃトナー１２の各々に、シリコーン樹脂で被覆した４５μｍフェライトキャリアとを混合し、トナー濃度が５質量％の現像剤を調製した。これら現像剤をトナーに対応して、Ｂｋ現像剤１／Ｙ現像剤１／Ｍ現像剤１／Ｃ現像剤１〜Ｂｋ現像剤１２／Ｙ現像剤１２／Ｍ現像剤１２／Ｃ現像剤１２とする。
【０１９７】
〔評価（非接触現像方式）〕
評価は、コニカ社製カラープリンター「ＫｏｎｉｃａＫＬ２０１０」を改造して使用した。条件を下記に示す。感光体としては積層型有機感光体を使用した。
【０１９８】
・感光体表面電位＝−７５０Ｖ
・ＤＣバイアス ＝−６１０Ｖ
・ＡＣバイアス ＝Ｖｐ−ｐ：２７００Ｖ
・交番電界周波数＝５０００Ｈｚ
・Ｄｓｄ ＝５７０μｍ
・押圧規制力 ＝０．１０Ｎ／ｍｍ
・押圧規制棒 ＝ＳＵＳ４１６（磁性ステンレス製）／直径３ｍｍ
・現像剤層厚 ＝１５０μｍ
・現像スリーブ ＝２０ｍｍ
定着器としては圧接方式の加熱定着器を採用した。
【０１９９】
なお、以下に実施例１〜４、６〜７、９、比較例１として現像剤の組み合わせを示す。
【０２００】
【表５】

【０２０１】
〔評価方法〕
上記した現像剤の組み合わせを使用し、前述の評価機を使用し、高温高湿環境（３０℃、８０％ＲＨ）にて画素率が全色合わせて１５％の画像を使用し２０，０００枚印字評価を実施した。下記に示す評価を初期と２０，０００枚後で実施し、変動の有無を確認した。
【０２０２】
画像として、初期と２０，０００枚後に１０％網点画像、２ドットライン、白紙、二次色画像（ＲＧＢ）を出力した。
【０２０３】
（１）１０％網点の濃度
２０ｍｍ×２０ｍｍの１０％網点画像部について、マクベス反射濃度計「ＲＤ−９１８」を用いて白地部に対する相対画像濃度を測定した。
【０２０４】
１０％網点濃度の評価は、ドットの再現性およびハーフトーンの再現性を評価するために行ったもので、濃度変化が０．１０以内であれば画質変化は少なく問題ないといえる。
【０２０５】
この評価についてはＢｋ現像剤についてのみ実施した。
（２）ライン幅
２ドットラインの画像信号に対応するライン画像のライン幅を印字評価システム「ＲＴ２０００」（ヤーマン社製）によって測定した。
【０２０６】
１枚目の形成画像のライン幅および２０，０００枚目の形成画像のライン幅の何れもが２００μｍ以下であり、かつ、ライン幅の変化が１０μｍ未満であれば、細線再現性は問題ないといえる。なお、この評価はＢｋ現像剤に限定して実施した。
【０２０７】
（３）カブリ濃度
印字されていない白紙について、マクベス反射濃度計「ＲＤ−９１８」を用いて２０ヶ所の絶対画像濃度を測定して平均し、白紙濃度とする。次に評価形成画像の白地部分について、同様に２０ヶ所の絶対画像濃度を測定して平均し、この平均濃度から白紙濃度を引いた値をカブリ濃度として評価した。
【０２０８】
カブリ濃度が０．０１０以下であれば、カブリは実用的に問題ないといえる。
（４）色差
１枚目の形成画像および２０，０００枚目の形成画像各々における二次色（レッド、ブルー、グリーン）のソリッド画像部の色を「Ｍａｃｂｅｔｈ Ｃｏｌｏｒ−Ｅｙｅ７０００」により測定し、ＣＭＣ（２：１）色差式を用いて色差を算出した。
【０２０９】
ＣＭＣ（２：１）色差式で求められた色差が５以下であれば、形成された画像の色味の変化が許容できる程度といえる。
【０２１０】
カラートナーの二次色の評価ついては、表５に示すトナーの組み合わせにより画像を形成して評価した。
【０２１１】
【表６】

【０２１２】
【表７】

【０２１３】
以上の様に、実施した画像形成によれば、本発明内のものは、画質に優れ、繰り返しの画像形成によっても画質の変化が少なく、二次色の色差も小さい。
【０２１４】
【発明の効果】
本発明により、現像性および細線再現性に優れ、高画質な画像を長期にわたって安定的に形成することができる静電荷像現像用トナーを提供することが出来る。
【０２１５】
又、現像性および細線再現性に優れ、高画質な画像を長期にわたって安定的に形成することができる画像形成方法を提供することが出来る。
【図面の簡単な説明】
【図１】攪拌翼の構成が一段の反応装置を示す説明図。
【図２】好ましく使用することのできる攪拌翼を備えた反応装置の一例を示す斜視図。
【図３】図２に示した反応装置の断面図。
【図４】好ましく使用することのできる攪拌翼を備えた反応装置の具体例を示す斜視図。
【図５】好ましく使用することのできる攪拌翼を備えた反応装置の具体例を示す斜視図。
【図６】好ましく使用することのできる攪拌翼を備えた反応装置の具体例を示す斜視図。
【図７】好ましく使用することのできる攪拌翼を備えた反応装置の具体例を示す斜視図。
【図８】好ましく使用することのできる攪拌翼を備えた反応装置の具体例を示す斜視図。
【図９】層流を形成させる場合に使用される反応装置の一例を示す斜視図。
【図１０】攪拌翼の形状の具体例を示す概略図。
【図１１】（ａ）は、角のないトナー粒子の投影像を示す説明図であり、（ｂ）および（ｃ）は、それぞれ角のあるトナー粒子の投影像を示す説明図。
【図１２】非接触現像方式による現像装置の一例を示す説明図。
【図１３】定着器の構成の一例を示す説明図。
【符号の説明】
１ 熱交換用ジャケット
２ 攪拌槽
３ 回転軸
４ 攪拌翼
４０，４１，４２，４３，４４，４５，４６ 下段に位置する攪拌翼
４１１，４２２，４３１，４４１ 折り曲げ部
４２１ スリット
４２３，４３２，４４２，５１１ フィン
５０，５１，５２，５３，５４，５６，６５ 上段に位置する攪拌翼
５５ 中段に位置する攪拌翼
５ａ，５ｂ，５ｃ，５ｄ 攪拌翼
６ｂ，６ｃ，６ｄ 中孔部
α 交差角
７３ 感光体
７４ 現像剤担持体
７５ スリーブ
７６ 磁石
７７ 二成分現像剤
７８ 現像剤層規制部材
７９ 現像領域
８０ 現像剤層
８１ 電源
８４ 加熱体
８５ アルミナ基板
８６ 抵抗材料
８７ 検温素子
８８ フィルム
８９ 駆動ローラー
９０ 従動ローラー
９１ 繰り出し軸
９２ 巻き取り軸
９３ 未定着トナー像
９４ 記録材
９５ 加圧ローラー
Ｄｓｄ 最小間隙[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrostatic charge image developing toner and an image forming method used for a copying machine, a printer, and the like.
[0002]
[Prior art]
In recent years, image forming techniques such as copying machines, printers, and facsimiles have been remarkably developed, and the most frequently used one belongs to an image forming method using an electrostatic image represented by an electrophotographic system.
[0003]
The reason is that this image method can form high-quality images at high speed, can form not only monochrome images but also color images, and has durability and stability that can withstand long-term use. I will.
[0004]
However, recently, the required level has gradually increased, and what has been considered to be sufficient in the past is now required to be further improved. In particular, there is a high demand for image quality improvement, and for this reason, the tendency to reduce the particle size of toner particles (which should actually be called colored particles but are often called toner particles) is remarkable.
[0005]
However, it is difficult to provide a sufficient charge amount with a toner having a reduced particle size. The reason for this is that since the particles are small, the surface area is large, and the van der Waals force is also large, so that the particles do not sufficiently rub against the charge imparting member. For this reason, when toner having a small particle diameter is used, problems such as toner scattering and fogging often occur. Furthermore, although the resolution is expected to be improved due to the small particle size, the resolution is often not improved as expected.
[0006]
[Problems to be solved by the invention]
The present invention has been made to solve the above problems.
[0007]
That is, an object of the present invention is to provide an electrostatic charge image developing toner that is excellent in developability and fine line reproducibility and can stably form a high-quality image over a long period of time.
[0008]
Another object of the present invention is to provide an image forming method that is excellent in developability and fine line reproducibility and can stably form a high-quality image over a long period of time.
[0009]
[Means for Solving the Problems]
The object of the present invention is the above-mentioned claims 1 to 4. 34 The electrostatic charge image developing toner according to any one of the above, or an image forming method can be used.
[0010]
As described above, the problem to be solved by the present invention is to provide a toner and an image forming method that are excellent in developability and fine line reproducibility and can form a high-quality image over a long period of time. Hereinafter, the present invention will be described in detail.
[0011]
As a result of examining the toner particles that easily contaminate the carrier, the developing sleeve, and the charge imparting member, the present inventors have found that the toner particles having irregular shapes and the toner particles having corner portions when the image forming process is repeated. Became prone to contamination. Although the reason for this is not clear, when the toner particles are uneven in shape, the toner composition is susceptible to mechanical stress due to stirring or the like inside the developing device, and a portion to which excessive stress is applied is generated. Was transferred to the contaminated material and adhered, and the chargeability of the toner was estimated to change.
[0012]
Further, the difference in how stress is applied varies depending on the particle size of the toner particles, and the smaller particle size has a higher adhesive force, so that it is likely to be contaminated when subjected to stress. When the toner particle size is large, such contamination is less likely to occur, but there is a problem that the image quality such as resolution is lowered.
[0013]
Furthermore, the initial toner charge amount distribution is also important for such contamination. When the charge amount distribution is wide, so-called selective development occurs in the image forming process, and toner particles that are difficult to develop accumulate in the developing device and developability deteriorates. By receiving the toner, contamination occurs or the surface property thereof changes to change the charging property, resulting in a problem that the image quality is deteriorated because the toner becomes weakly charged or has a reverse polarity.
[0014]
As a result of examining the toner charge amount distribution, in order to make the toner charge amount distribution extremely sharp, it is necessary to control the variation in the particle size of the toner particles to be small and the shape variation to be small. It has been found. By making the toner charge amount distribution extremely sharp, even when the toner charge amount is set low, it is possible to obtain stable chargeability over a long period of time.
[0015]
As a result of intensive studies, the present inventors have found that the object of the present invention can be achieved by using toner particles having the above specific particle shape and distribution in combination with an external additive containing a titanate compound.
[0016]
That is, the inventors have found that it is effective to add an external additive having a charge imparting ability in order to maintain chargeability with a small particle size toner, and have completed the present invention.
[0017]
As this material, a titanic acid compound is preferably used.
The reason why this compound has a large charge stabilization effect is not clear, but it is considered that it is a high dielectric material. By using a titanic acid compound that is a high dielectric material, it is presumed that the chargeability-imparting ability of a small particle toner can be expanded and the chargeability can be stabilized.
[0018]
Examples of titanate compounds include strontium titanate, barium titanate, calcium titanate, magnesium titanate and the like.
[0019]
The particle diameter of this is a number average primary particle diameter of 100 to 2000 nm, preferably 200 to 1000 nm. When this particle size is smaller than the above, the charge imparting ability is lowered, and the contribution to stabilization of chargeability may be lowered. On the other hand, when the particle size is larger than the above range, there is a problem that the toner particles are easily separated from the toner particles, the adhesion to the photoconductor is increased, and the photoconductor is easily damaged.
[0020]
The amount of this added is 0.1 to 10.0% by mass, preferably 0.3 to 5.0% by mass, more preferably 0.4 to 2.0% by mass, based on the toner. . If the addition amount is less than this range, the effect of stabilizing the charge may not occur. If the addition amount exceeds this range, a phenomenon such as desorption of the titanate compound from the toner may occur, and May cause problems such as scratches on the body.
[0021]
Other external additives may be used in combination with the external additive of the present invention. Specifically, fine particles such as inorganic fine particles and organic fine particles can be added.
[0022]
As the inorganic fine particles, inorganic oxide particles such as silica, titania, and alumina are preferably used, and these inorganic fine particles are preferably hydrophobized with a silane coupling agent or a titanium coupling agent. The degree of the hydrophobizing treatment is not particularly limited, but a methanol wettability of 40 to 95 is preferable. Methanol wettability is an evaluation of wettability to methanol. In this method, 0.2 g of inorganic fine particles to be measured is weighed and added to 50 ml of distilled water in a 200 ml beaker. Methanol is slowly added dropwise from a burette whose tip is immersed in the liquid until the whole of the inorganic fine particles become wet with slow stirring. When the amount of methanol necessary to completely wet the inorganic fine particles is a (ml), the degree of hydrophobicity is calculated by the following formula.
[0023]
Hydrophobicity = (a / (a + 50)) × 100
The addition amount of the external additive is 0.1 to 5.0% by mass, preferably 0.5 to 4.0% by mass in the toner. In addition, various external additives may be used in combination.
[0024]
On the other hand, for toner particles, the development coefficient and fine line reproduction are achieved by using toner composed of toner particles having a shape coefficient variation coefficient of 16% or less and a number variation coefficient in the number particle size distribution of 27% or less. As a result, it has been found that high quality images can be formed over a long period of time, and the first invention of the present invention (described in claims 1 to 8) has been completed.
[0025]
Furthermore, as a result of investigations by paying attention to the minute shape of each toner particle, the present inventors have changed the shape of the corner portion of the toner particle to become round inside the developing device, and the portion is contaminated. It turned out that it was letting. Although the reason for this is not clear, it is presumed that stress is easily applied to the corner portion, and the toner composition moves to and adheres to the contaminated material due to wear and breakage of this portion, thereby changing the chargeability of the toner.
[0026]
In addition, when charge is applied to the toner particles by frictional charging, it is presumed that the charge tends to concentrate particularly at the corners, and the toner particles are likely to be non-uniformly charged.
[0027]
That is, by using toner composed of toner particles in which the number of toner particles having no corners is 50% by number or more and the number variation coefficient in the number particle size distribution is controlled to 27% or less, developability and fine line reproduction are also achieved. It has been found that a high-quality image can be formed over a long period of time, and the second invention of the present invention (described in claims 9 to 15) has been completed.
[0028]
Further, it has been found that even when the toner is made to have a specific shape, the contamination by the toner composition is reduced and the charge amount distribution becomes sharp.
[0029]
That is, even when toner having a shape factor of 1.2 to 1.6 in which the proportion of toner particles is 65% by number or more and the variation coefficient of the shape factor is 16% or less, developability, fine line It has been found that an image with excellent reproducibility and high image quality can be formed over a long period of time, and the third invention of the present invention (described in claims 16 to 21) has been completed.
[0030]
In addition, there are image forming methods including a developing process in which a photoconductor and a developer are made to face each other and visualize with toner, and a multicolor image forming method in which a plurality of color toners are stacked to form an image, or a toner is ejected in a non-contact state. There is an image forming method to be performed. In color toner development, four color toners are used, and color reproducibility is measured by performing color superposition. For this reason, if there is a change in the adhesion amount of the toner itself, that is, a change in developability, a problem occurs in color reproducibility. Further, since non-contact development is an image forming method in which toner is allowed to fly in the development region, the change in charging property of the toner itself leads to the change in flight as it is, and problems such as selective development are likely to occur.
[0031]
By using the toner particles of the present invention in combination with an external additive comprising a titanate compound, as described above, the charge amount distribution is sharp and stable chargeability can be maintained over a long period of time. In the image forming method described above, it has been found that a particularly great effect is exhibited that it is excellent in developability and fine line reproducibility and can form a high-quality image over a long period of time. Item 22 to 42)).
[0032]
The “shape factor” of the toner of the present invention is represented by the following formula and indicates the degree of roundness of the toner particles.
[0033]
Shape factor = ((maximum diameter / 2) ² × π) / projection area
Here, the maximum diameter refers to the width of a particle that maximizes the interval between the parallel lines when the projected image of the toner particles on the plane is sandwiched between two parallel lines. The projected area refers to the area of the projected image of the toner particles on the plane.
[0034]
In the present invention, this shape factor is obtained by taking a photograph in which the toner particles are magnified 2000 times with a scanning electron microscope, and then using “SCANNING IMAGE ANALYZER” (manufactured by JEOL Ltd.) based on this photograph. It was measured by performing analysis. At this time, the shape factor of the present invention was measured by the above formula using 100 toner particles.
[0035]
In the toner of the present invention, the ratio of the toner particles having the shape factor in the range of 1.0 to 1.6 is preferably 65% by number or more, and more preferably 70% by number or more. More preferably, the ratio of the toner particles having the shape factor in the range of 1.2 to 1.6 is 65% by number or more, and more preferably 70% by number or more.
[0036]
When the ratio of the toner particles having the shape factor in the range of 1.0 to 1.6 is 65% by number or more, the density of toner particles in the toner layer transferred to the transfer material is increased, and the fixing property is improved. The offset is less likely to occur. In addition, the toner particles are less likely to be crushed, the contamination of the charging member is reduced, and the chargeability of the toner is stabilized.
[0037]
In the present invention, the ratio of the toner particles having the shape factor in the range of 1.2 to 1.6 needs to be 65% by number or more, and preferably 70% by number or more.
[0038]
The method for controlling the shape factor is not particularly limited. For example, a method in which toner particles are sprayed in a hot air stream, a method in which toner particles are repeatedly applied with mechanical energy due to impact force in a gas phase, a method in which a toner is not dissolved in a solvent and a swirl flow is applied. A method in which toner particles having a shape factor of 1.0 to 1.6 or 1.2 to 1.6 are prepared and added to a normal toner so as to fall within the scope of the present invention. is there. In addition, toner particles whose shape factor is adjusted to 1.0 to 1.6 or 1.2 to 1.6 are added to normal toner in the same manner by controlling the overall shape at the stage of preparing a so-called polymerization method toner. There is a way to adjust.
[0039]
Among the above methods, the polymerization toner is preferable because it is simple as a production method and has excellent surface uniformity as compared with the pulverized toner.
[0040]
The “shape coefficient variation coefficient” of the toner of the present invention is calculated from the following equation.
Coefficient of variation (%) = (S ₁ / K) × 100
Where S ₁ Indicates the standard deviation of the shape factor of 100 toner particles, and K indicates the average value of the shape factor.
[0041]
The variation coefficient of the shape factor is 16% or less, preferably 14% or less. When the variation coefficient of the shape factor is 16% or less, the charge amount distribution becomes sharp and the image quality is improved.
[0042]
In order to uniformly control the shape factor of the toner and the variation coefficient of the shape factor without variation in lots, the resin particles (polymer particles) constituting the toner of the present invention are prepared (polymerized), and the resin particles are melted. In the process of controlling the attachment and shape, an appropriate process end time may be determined while monitoring the characteristics of the toner particles (colored particles) being formed.
[0043]
Monitoring means that a measuring device is incorporated in-line, and process conditions are controlled based on the measurement result. In other words, in the case of a polymerization method toner that is formed by incorporating measurement such as shape in-line, for example, by associating or fusing resin particles in an aqueous medium, the shape and particle size are measured while performing sequential sampling in the fusing step. The reaction is stopped when the desired shape is obtained.
[0044]
Although it does not specifically limit as a monitoring method, The flow type particle image analyzer FPIA-2000 (made by Toa Medical Electronics Co., Ltd.) can be used. This apparatus is suitable because the shape can be monitored by performing image processing in real time while passing the sample liquid. That is, a pump or the like is used from the reaction field and is constantly monitored to measure the shape and the like, and the reaction is stopped when the desired shape is obtained.
[0045]
The number particle size distribution and the number variation coefficient of the toner of the present invention are measured by a Coulter Counter TA-II or Coulter Multisizer (manufactured by Coulter Inc.). In the present invention, a Coulter Multisizer is used, and an interface (manufactured by Nikkaki Co., Ltd.) that outputs a particle size distribution and a personal computer are connected. The aperture used in the Coulter Multisizer was 100 μm, and the volume and number of toners of 2 μm or more were measured to calculate the particle size distribution and average particle size. The number particle size distribution represents the relative frequency of the toner particles with respect to the particle size, and the number average particle size represents the median diameter in the number particle size distribution. The “number variation coefficient in the number particle size distribution” of the toner is calculated from the following equation.
[0046]
Number variation coefficient (%) = (S ₂ / D _n ) × 100
Where S ₂ Indicates the standard deviation in the number particle size distribution, D _n Indicates the number average particle diameter (μm).
[0047]
In the present invention, the number variation coefficient is 27% or less, preferably 25% or less. When the number variation coefficient is 27% or less, the charge amount distribution becomes sharp, the transfer efficiency is increased, and the image quality is improved.
[0048]
The method for controlling the number variation coefficient in the toner of the present invention is not particularly limited. For example, a method of classifying toner particles by wind force can be used, but classification in a liquid is effective for reducing the number variation coefficient. As a method of classifying in this liquid, there is a method of separating and collecting toner particles according to a difference in sedimentation speed caused by a difference in toner particle diameter by using a centrifuge and controlling the rotation speed.
[0049]
In particular, when a toner is produced by a suspension polymerization method, a classification operation is indispensable in order to make the number variation coefficient in the number particle size distribution 27% or less. In the suspension polymerization method, it is necessary to disperse a polymerizable monomer in an oil droplet having a desired size as a toner in an aqueous medium before polymerization. In other words, repeated mechanical shearing by a homomixer, homogenizer, etc. on large oil droplets of a polymerizable monomer reduces the oil droplets to the size of toner particles. In the method using shearing, the number particle size distribution of the obtained oil droplets is wide, and therefore the particle size distribution of the toner obtained by polymerizing the oil droplets is also wide. For this reason, classification operation is essential.
[0050]
In the toner particles constituting the toner of the present invention, the ratio of toner particles having no corners is required to be 50% by number or more, and this ratio is preferably 70% by number or more.
[0051]
When the ratio of toner particles having no corners is 50% by number or more, toner particles that are easily worn and broken and toner particles having a portion where charges are concentrated are reduced, the charge amount distribution becomes sharp, and the charge is reduced. The stability is also stable and good image quality can be formed over a long period of time.
[0052]
Here, the “toner particles having no corners” means toner particles having substantially no protrusions that concentrate electric charges or protrusions that easily wear due to stress. Specifically, the following toner particles are used. Is called toner particles having no corners. That is, as shown in FIG. 11A, when the major axis of the toner particle T is L, a circle C having a radius (L / 10) is in contact with the peripheral line of the toner particle T at one point inside. A case where the circle C does not substantially protrude outside the toner T when the inner side is rolled is referred to as “toner particles having no corners”. “A case where the protrusion does not substantially protrude” refers to a case where the protrusion having the protruding circle is one or less. The “major diameter of toner particles” refers to the width of a particle that maximizes the interval between the parallel lines when the projected image of the toner particles on a plane is sandwiched between two parallel lines. FIGS. 11B and 11C show projection images of toner particles having corners, respectively.
[0053]
The ratio of toner particles having no corners was measured as follows. First, an enlarged photograph of the toner particles is taken with a scanning electron microscope, and further enlarged to obtain a 15,000 times photographic image. The photographic image is then measured for the presence or absence of the corners. This measurement was performed on 100 toner particles.
[0054]
A method for obtaining toner having no corners is not particularly limited. For example, as described above as a method for controlling the shape factor, a method in which toner particles are sprayed into a hot air stream, a method in which toner particles are repeatedly applied with mechanical energy by impact force in a gas phase, or a toner is dissolved. It can be obtained by adding in a solvent that does not, and applying a swirling flow.
[0055]
Further, in the polymerization toner formed by associating or fusing the resin particles, the fusing particle surface has many irregularities at the fusing stop stage, and the surface is not smooth, but the temperature in the shape control step, By making the conditions such as the number of revolutions of the stirring blade and the stirring time appropriate, a toner having no corners can be obtained. These conditions vary depending on the physical properties of the resin particles. For example, by setting the rotational speed to be higher than the glass transition temperature of the resin particles, the toner can be formed with a smooth surface and no corners.
[0056]
The toner of the present invention preferably has a number average particle diameter of 3 to 8 μm. When the toner particles are formed by a polymerization method, this particle size is determined in the toner production method described in detail later, in the concentration of the aggregating agent, the amount of organic solvent added, or the fusing time, and further the composition of the polymer itself. Can be controlled by.
[0057]
When the number average particle diameter is 3 to 8 μm, the transfer efficiency is increased, the image quality of halftone is improved, and the image quality of fine lines and dots is improved.
[0058]
As the toner of the present invention, when the particle size of the toner particle is D (μm), the natural logarithm lnD is taken on the horizontal axis, and the number-based particle size distribution is divided into a plurality of classes at intervals of 0.23. In the histogram shown, the sum (M) of the relative frequency (m1) of the toner particles included in the most frequent class and the relative frequency (m2) of the toner particles included in the next most frequent class after the most frequent class is 70. % Of the toner is preferable.
[0059]
When the sum (M) of the relative frequency (m1) and the relative frequency (m2) is 70% or more, the dispersion of the particle size distribution of the toner particles becomes narrow. Therefore, selective development can be performed by using the toner in the image forming process. Can be reliably suppressed.
[0060]
In the present invention, the histogram showing the particle size distribution based on the number is a natural logarithm lnD (D: particle size of individual toner particles) having a plurality of classes (0 to 0.23: 0.23) at intervals of 0.23. 0.46: 0.46-0.69: 0.69-0.92: 0.92-1.15: 1.15-1.38: 1.38-1.61: 1.61-1. 84: 1.84 to 2.07: 2.07 to 2.30: 2.30 to 2.53: 2.53 to 2.76, and so on). This histogram was created by transferring the particle size data of the sample measured by the Coulter Multisizer to the computer via the I / O unit according to the following conditions and using the particle size distribution analysis program in the computer. is there.
[0061]
〔Measurement condition〕
(1) Aperture: 100 μm
(2) Sample preparation method: Electrolyte [ISOTON R-11 (manufactured by Coulter Scientific Japan)] 50-100 ml, an appropriate amount of a surfactant (neutral detergent) was added and stirred, and a measurement sample 10-20 mg was added thereto. Add This system is prepared by dispersing for 1 minute with an ultrasonic disperser.
[0062]
Comparison with conventionally known toner
The above-described numerical values of conventionally known toners will be described in comparison with the toner of the present invention. Needless to say, this numerical value varies depending on the manufacturing method and conditions.
[0063]
In the case of ordinary pulverized toner, the ratio of toner particles having a shape factor of 1.2 to 1.6 is about 60% by number. The variation coefficient of the shape factor of this is about 20%. Further, in the pulverization method, in order to reduce the particle size while repeating the crushing, the toner particles have more corners, and the proportion of toner particles without corners is 30% by number or less. Therefore, in order to obtain a rounded toner with uniform shapes and no corners, a process for spheroidizing with heat or the like as described above is required as a method for controlling the shape factor. In addition, the number variation coefficient in the number particle size distribution is about 30% when the classification operation after pulverization is one time, and in order to make the number variation coefficient 27% or less, it is necessary to repeat the classification operation. There is.
[0064]
In the case of a toner by suspension polymerization, since it is conventionally polymerized in a laminar flow, substantially spherical toner particles are obtained. For example, in the toner described in JP-A-56-130762, the shape factor is 1 The ratio of toner particles having a diameter of 2 to 1.6 is about 20% by number, the coefficient of variation of the shape factor is about 18%, and the ratio of toner particles without corners is about 85% by number. As described above, as a method for controlling the number variation coefficient in the number particle size distribution, mechanical shearing is repeatedly performed on large oil droplets of the polymerizable monomer to reduce the oil droplets to the size of toner particles. Therefore, the distribution of the oil droplet diameter is wide, and therefore the particle size distribution of the obtained toner is wide, the number variation coefficient is as large as about 32%, and classification operation is necessary to reduce the number variation coefficient. .
[0065]
In the polymerization method toner formed by associating or fusing resin particles, for example, in the toner described in JP-A-63-186253, the ratio of toner particles having a shape factor of 1.2 to 1.6 Is about 60% by number, the coefficient of variation of the shape factor is about 18%, and the proportion of toner particles without corners is about 44% by number. Further, the particle size distribution of the toner is wide, the number variation coefficient is 30%, and classification operation is necessary to reduce the number variation coefficient.
[0066]
Toner production method
The toner of the present invention is preferably a toner obtained by polymerizing at least a polymerizable monomer in an aqueous medium, and is preferably a toner obtained by associating at least resin particles in an aqueous medium. . Hereinafter, the method for producing the toner of the present invention will be described in detail.
[0067]
In the toner of the present invention, fine polymer particles (resin particles) are prepared by emulsion polymerization of monomers in a suspension polymerization method or in a liquid (aqueous medium) to which an emulsion of necessary additives is added. Thereafter, an organic solvent, a flocculant and the like can be added to produce the resin particles in association with each other. Here, “association” means that a plurality of the resin particles are fused, and includes cases where the resin particles and other particles (for example, colorant particles) are fused.
[0068]
An example of the method for producing the toner of the present invention is as follows. A homogenizer is prepared by adding various constituent materials such as a colorant and, if necessary, a release agent, a charge control agent, and a polymerization initiator to the polymerizable monomer. Then, various constituent materials are dissolved or dispersed in the polymerizable monomer by a sand mill, a sand grinder, an ultrasonic disperser or the like. The polymerizable monomer in which these various constituent materials are dissolved or dispersed is dispersed in oil droplets having a desired size as a toner in an aqueous medium containing a dispersion stabilizer using a homomixer or a homogenizer. Thereafter, the stirring mechanism is transferred to a reaction device (stirring device) which is a stirring blade described later, and the polymerization reaction is advanced by heating. After completion of the reaction, the dispersion stabilizer is removed, filtered, washed, and dried to prepare the toner of the present invention.
[0069]
In the present invention, the “aqueous medium” refers to a medium containing at least 50% by mass of water.
[0070]
Further, as a method for producing the toner of the present invention, a method of preparing by associating or fusing resin particles in an aqueous medium can also be mentioned. This method is not particularly limited, and examples thereof include methods described in JP-A Nos. 5-265252, 6-329947, and 9-15904. That is, a method of associating a plurality of fine particles composed of resin particles and colorants, etc., or particles composed of resin and colorant, in particular, after dispersing them in water using an emulsifier, the critical aggregation concentration The above flocculant is added for salting out, and at the same time, the formed polymer itself is heated and fused at a temperature higher than the glass transition temperature to gradually grow the particle size while forming fused particles. Then, a large amount of water is added to stop the particle size growth, and the shape is controlled by smoothing the particle surface while heating and stirring, and the particles are heated and dried in a fluid state while containing water. The toner of the invention can be formed. Here, a solvent that is infinitely soluble in water may be added simultaneously with the flocculant.
[0071]
As the polymerizable monomer constituting the resin, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decyl Styrene, styrene or styrene derivatives such as pn-dodecylstyrene, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, Methacrylic acid ester derivatives such as lauryl tacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, acrylic Isobutyl acid, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, acrylic acid ester derivatives such as phenyl acrylate, olefins such as ethylene, propylene, isobutylene, vinyl chloride, vinylidene chloride, odor Halogenated vinyls such as vinyl fluoride, vinyl fluoride, vinylidene fluoride, vinyl esters such as vinyl propionate, vinyl acetate, vinyl benzoate, vinyl methyl ether, vinyl ethyl ether Vinyl ethers such as vinyl, vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, N-vinyl compounds such as N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone, vinyl naphthalene, vinyl pyridine, etc. There are acrylic acid or methacrylic acid derivatives such as vinyl compounds, acrylonitrile, methacrylonitrile, acrylamide and the like. These vinyl monomers can be used alone or in combination.
[0072]
Further, it is more preferable to use a combination of monomers having an ionic dissociation group as the polymerizable monomer constituting the resin. For example, it has a substituent such as a carboxyl group, a sulfonic acid group, a phosphoric acid group as a constituent group of the monomer, specifically, acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumar Acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, styrene sulfonic acid, allyl sulfosuccinic acid, 2-acrylamido-2-methylpropane sulfonic acid, acid phosphooxyethyl methacrylate, 3-chloro-2-acid phosphooxy And propyl methacrylate.
[0073]
Furthermore, polyfunctionality such as divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, etc. It is also possible to use a crosslinkable resin by using a functional vinyl.
[0074]
These polymerizable monomers can be polymerized using a radical polymerization initiator. In this case, an oil-soluble polymerization initiator can be used in the suspension polymerization method. Examples of the oil-soluble polymerization initiator include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carboxyl). Nitriles), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo- or diazo-based polymerization initiators such as azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate , Cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis- (4,4- t-butylperoxycyclohexyl) propane, tris The (t-butylperoxy) triazine peroxide polymerization initiator or a peroxide, such as and the like polymeric initiator having a side chain.
[0075]
Moreover, when using an emulsion polymerization method, a water-soluble radical polymerization initiator can be used. Examples of the water-soluble radical polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropane acetate, azobiscyanovaleric acid and its salts, hydrogen peroxide, and the like.
[0076]
Dispersion stabilizers include tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate , Bentonite, silica, alumina and the like. Furthermore, those generally used as surfactants such as polyvinyl alcohol, gelatin, methylcellulose, sodium dodecylbenzenesulfonate, ethylene oxide adduct, and higher alcohol sodium sulfate can be used as the dispersion stabilizer.
[0077]
As the resin excellent in the present invention, those having a glass transition point of 20 to 90 ° C. are preferred, and those having a softening point of 80 to 220 ° C. are preferred. The glass transition point is measured by a differential calorimetric analysis method, and the softening point can be measured by a Koka flow tester. Further, these resins preferably have a molecular weight measured by gel permeation chromatography of 1,000 to 100,000 in terms of number average molecular weight (Mn) and 2000 to 1,000,000 in terms of weight average molecular weight (Mw). Further, the molecular weight distribution is preferably such that Mw / Mn is 1.5 to 100, particularly 1.8 to 70.
[0078]
The flocculant used for associating the resin particles in an aqueous medium is not particularly limited, but those selected from metal salts are preferably used. Specifically, as a monovalent metal, for example, an alkali metal salt such as sodium, potassium or lithium, as a divalent metal, for example, an alkaline earth metal salt such as calcium or magnesium, or a divalent metal such as manganese or copper. And salts of trivalent metals such as iron and aluminum, and specific salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, etc. Can be mentioned. These may be used in combination.
[0079]
These flocculants are preferably added in an amount equal to or higher than the critical aggregation concentration. The critical flocculation concentration is an index relating to the stability of the aqueous dispersion, and indicates a concentration at which flocculation occurs when a flocculant is added. This critical aggregation concentration varies greatly depending on the emulsified components and the dispersant itself. For example, it is described in Seizo Okamura et al., “Polymer Chemistry 17, 601 (1960) edited by the Japanese Society of Polymer Science”, and the like, and a detailed critical aggregation concentration can be obtained. As another method, a desired salt is added to the target particle dispersion at different concentrations, the ζ (zeta) potential of the dispersion is measured, and the salt concentration at which this value changes is defined as the critical aggregation concentration. You can ask for it.
[0080]
The addition amount of the flocculant of the present invention may be not less than the critical aggregation concentration, but is preferably 1.2 times or more, more preferably 1.5 times or more the critical aggregation concentration.
[0081]
As the “solvent that dissolves infinitely in water” used together with the flocculant, a solvent that does not dissolve the formed resin is selected. Specific examples include alcohols such as methanol, ethanol, propanol, isopropanol, t-butanol, methoxyethanol, and butoxyethanol, nitriles such as acetonitrile, and ethers such as dioxane. In particular, ethanol, propanol, and isopropanol are preferable.
[0082]
The amount of the solvent that is infinitely soluble in water is preferably 1 to 100% by volume with respect to the polymer-containing dispersion added with the flocculant.
[0083]
In order to make the particle shape uniform, it is preferable to fluidly dry a slurry containing 10% by mass or more of water based on the particle after preparing and filtering the toner particle. Those having a polar group therein are preferred. The reason for this is considered to be that it is particularly easy to make the shape uniform in order to exhibit the effect that the water present is somewhat swollen with respect to the polymer in which the polar group is present.
[0084]
The toner of the present invention contains at least a resin and a colorant, but may contain a release agent, a charge control agent, or the like, which is a fixability improving agent, if necessary. Further, an external additive composed of inorganic fine particles or organic fine particles may be added to the toner particles containing the resin and the colorant as main components.
[0085]
As the colorant used in the toner of the present invention, carbon black, a magnetic material, a dye, a pigment, and the like can be arbitrarily used. Examples of the carbon black include channel black, furnace black, acetylene black, thermal black, and lamp black. used. Magnetic materials include ferromagnetic metals such as iron, nickel and cobalt, alloys containing these metals, compounds of ferromagnetic metals such as ferrite and magnetite, alloys that do not contain ferromagnetic metals but exhibit ferromagnetism by heat treatment, For example, a kind of alloy called Heusler alloy such as manganese-copper-aluminum, manganese-copper-tin, chromium dioxide, or the like can be used.
[0086]
As the dye, C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95 etc. can be used, and a mixture thereof can also be used. Examples of the pigment include C.I. I. Pigment Red 5, 48: 1, 53: 1, 57: 1, 122, 139, 144, 149, 166, 177, 178, 222, C.I. I. Pigment Orange 31 and 43, C.I. I. Pigment Yellow 14, 17, 93, 94, 138, 155, 156, 180, 185, C.I. I. Pigment green 7, C.I. I. Pigment Blue 15: 3, 60, etc. can be used, and a mixture thereof can also be used. The number average primary particle diameter varies depending on the type, but is preferably about 10 to 200 nm.
[0087]
As a method for adding the colorant, the polymer particles prepared by the emulsion polymerization method are added at the stage of agglomerating by adding an aggregating agent, and the polymer is colored, or at the stage of polymerizing the monomer. The method of adding and polymerizing the toner particles to obtain toner particles can be used. In addition, when adding a coloring agent in the step which prepares a polymer, it is preferable to use it, treating the surface with a coupling agent etc. so that radical polymerization property may not be inhibited.
[0088]
Further, a low molecular weight polypropylene (number average molecular weight = 1500 to 9000), a low molecular weight polyethylene, or the like as a fixing property improving agent may be added.
[0089]
Similarly, various known charge control agents and those that can be dispersed in water can be used. Specific examples include nigrosine dyes, naphthenic acid or higher fatty acid metal salts, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, salicylic acid metal salts or metal complexes thereof.
[0090]
In addition, it is preferable that the number average primary particle diameter of these charge control agent and fixability improving agent particles is about 10 to 500 nm in a dispersed state.
[0091]
In the toner of the present invention, an external additive other than the titanic acid compound may be used as an external additive. Specifically, fine particles such as inorganic fine particles and organic fine particles can be added.
[0092]
As the inorganic fine particles, inorganic oxide particles such as silica, titania, and alumina are preferably used, and these inorganic fine particles are preferably hydrophobized with a silane coupling agent or a titanium coupling agent. The degree of the hydrophobizing treatment is not particularly limited, but a methanol wettability of 40 to 95 is preferable. Methanol wettability is an evaluation of wettability to methanol. In this method, 0.2 g of inorganic fine particles to be measured is weighed and added to 50 ml of distilled water in a 200 ml beaker. Methanol is slowly added dropwise from a burette whose tip is immersed in the liquid until the whole of the inorganic fine particles become wet with slow stirring. When the amount of methanol necessary to completely wet the inorganic fine particles is a (ml), the degree of hydrophobicity is calculated by the following formula.
[0093]
Hydrophobicity = (a / (a + 50)) × 100
The addition amount of the external additive is 0.1 to 5.0% by mass, preferably 0.5 to 4.0% by mass in the toner. In addition, various external additives may be used in combination.
[0094]
In a suspension polymerization method toner in which a toner component obtained by dispersing or dissolving a toner component such as a colorant in a so-called polymerizable monomer is suspended in an aqueous medium and then polymerized. The shape of the toner particles can be controlled by controlling the flow of the medium. That is, when a large amount of toner particles having a shape factor of 1.2 or more are formed, the flow of the medium in the reaction vessel is turbulent and the polymerization proceeds to exist in an aqueous medium in a suspended state. When the oil droplets gradually become polymerized, the oil droplets become soft particles. By colliding the particles, particle coalescence is promoted, and particles with an irregular shape are obtained. . In the case of forming substantially spherical toner particles having a shape factor of less than 1.2, substantially spherical particles can be obtained by using a laminar flow of the medium in the reaction vessel to avoid particle collision. By this method, the toner shape distribution can be controlled within the scope of the present invention.
[0095]
Reactor
FIG. 1 is an explanatory view showing a reaction device (stirring device) having a generally used stirrer blade structure, wherein 2 is a stirrer tank, 3 is a rotating shaft, 4 is a stirrer blade, and 9 is a turbulent flow It is a forming member.
[0096]
In the suspension polymerization method, a turbulent flow can be formed by using a specific stirring blade, and the shape can be easily controlled. Although it is not clear as this reason, when the structure of the stirring blade 4 as shown in FIG. 1 is one stage, the flow of the medium formed in the stirring tank 2 is a wall surface from the lower part to the upper part of the stirring tank 2. It becomes only the flow that moves along. Therefore, conventionally, a turbulent flow is generally formed by arranging a turbulent flow forming member 9 such as a wall surface of the stirring tank 2 to increase the efficiency of stirring. However, in such an apparatus configuration, although the turbulent flow is partially formed, the fluid flow acts in the direction of stagnation due to the presence of the turbulent flow. I can't control it.
[0097]
A reactor equipped with a stirring blade that can be preferably used in the suspension polymerization method will be described with reference to the drawings.
[0098]
2 and 3 are a perspective view and a cross-sectional view showing an example of such a reaction apparatus, respectively. In the reaction apparatus shown in FIGS. 2 and 3, a rotating shaft 3 is vertically suspended at the center of a vertical cylindrical stirring tank 2 in which a jacket 1 for heat exchange is mounted on the outer periphery, and stirring is performed on the rotating shaft 3. A lower stirrer blade 40 disposed close to the bottom surface of the tank 2 and a stirrer blade 50 disposed further upward are provided. The upper agitating blade 50 is disposed with a crossing angle α preceding the agitating blade 40 located in the lower stage in the rotational direction. In the production of the toner of the present invention, the crossing angle α is preferably less than 90 degrees (°). The lower limit of the intersection angle α is not particularly limited, but is preferably about 5 degrees or more, and more preferably 10 degrees or more. When a three-stage stirring blade is provided, the crossing angle between adjacent stirring blades is preferably less than 90 degrees.
[0099]
By setting it as such a structure, a medium is first stirred by the stirring blade 50 arrange | positioned in the upper stage, and the flow to the lower side is formed. Next, the flow formed by the upper stirring blade 50 is further accelerated downward by the stirring blade 40 disposed in the lower stage, and a downward flow is also separately formed in the stirring blade 50 itself, and the flow as a whole is increased. Presumed to be accelerated and proceed. As a result, a flow area having a large shear stress formed as a turbulent flow is formed, and it is estimated that the shape of the obtained toner particles can be controlled.
[0100]
2 and 3, arrows indicate the rotation direction, 7 is an upper material inlet, 8 is a lower material inlet, and 9 is a turbulent flow forming member for making stirring effective.
[0101]
Here, the shape of the stirring blade is not particularly limited, but it may be a rectangular plate, a notch in a part of the blade, one or more holes in the center, and a so-called slit. Can be used. Specific examples of these are shown in FIG. The stirring blade 5a shown in FIG. 10 (a) has no medium hole, the stirring blade 5b shown in FIG. 10 (b) has a large middle hole 6b in the center, and the stirring blade 5c shown in FIG. 10 (c). Has a horizontally elongated hole 6c (slit), and the stirring blade 5d shown in FIG. 4D has a vertically elongated hole 6d (slit). In addition, when a three-stage stirring blade is provided, the middle hole formed in the upper stirring blade and the middle hole formed in the lower stirring blade may be the same, even if they are different. There may be.
[0102]
4 to 8 are perspective views showing specific examples of a reactor equipped with a stirring blade that can be preferably used. In FIGS. 4 to 8, 1 is a jacket for heat exchange, and 2 is a stirring device. A tank, 3 is a rotating shaft, 7 is an upper material inlet, 8 is a lower material inlet, and 9 is a turbulent flow forming member.
[0103]
In the reaction apparatus shown in FIG. 4, a bent portion 411 is formed on the stirring blade 41, and a fin (projection) 511 is formed on the stirring blade 51.
[0104]
In addition, when the bending part is formed in the stirring blade, it is preferable that a bending angle is 5-45 degrees.
[0105]
In the stirring blade 42 constituting the reaction apparatus shown in FIG. 5, a slit 421 is formed, and a bent portion 422 and fins 423 are formed.
[0106]
In addition, the stirring blade 52 which comprises the said reaction apparatus has a shape similar to the stirring blade 50 which comprises the reaction apparatus shown in FIG.
[0107]
Bending portions 431 and fins 432 are formed on the stirring blade 43 constituting the reaction apparatus shown in FIG.
[0108]
In addition, the stirring blade 53 which comprises the said reaction apparatus has the shape similar to the stirring blade 50 which comprises the reaction apparatus shown in FIG.
[0109]
Bending portions 441 and fins 442 are formed on the stirring blade 44 constituting the reaction apparatus shown in FIG.
[0110]
In addition, the stirring blade 54 constituting the reaction apparatus has a middle hole portion 541 formed at the center.
[0111]
The reaction apparatus shown in FIG. 8 is provided with a three-stage stirring blade including a stirring blade 45 (lower stage), a stirring blade 55 (middle stage), and a stirring blade 65.
[0112]
A stirring blade having a structure having these bent portions and protrusions (fins) to the upper or lower portion effectively generates turbulent flow.
[0113]
The gap between the upper and lower stirring blades having the above-described configuration is not particularly limited, but it is preferable to have a gap at least between the stirring blades. Although the reason for this is not clear, it is considered that the stirring efficiency is improved because a medium flow is formed through the gap. However, the gap has a width of 0.5 to 50%, preferably 1 to 30%, with respect to the liquid surface height in the stationary state.
[0114]
Further, the size of the stirring blade is not particularly limited, but the total height of all the stirring blades is 50% to 100%, preferably 60% to 95% of the liquid surface height in the stationary state. is there.
[0115]
FIG. 9 shows an example of a reaction apparatus used when a laminar flow is formed in the suspension polymerization method. This reaction apparatus is characterized in that a turbulent flow forming member (an obstacle such as a baffle plate) is not provided.
[0116]
The agitating blade 46 and the agitating blade 56 constituting the reaction apparatus shown in FIG. 9 have the same shape and crossing angle α as the agitating blade 40 and the agitating blade 50 constituting the reaction apparatus shown in FIG. . In FIG. 9, 1 is a heat exchange jacket, 2 is a stirring tank, 3 is a rotating shaft, 7 is an upper material inlet, and 8 is a lower material inlet.
[0117]
In addition, as a reaction apparatus used when forming a laminar flow, it is not limited to what is shown by FIG.
[0118]
Further, the shape of the stirring blade constituting the reaction apparatus is not particularly limited as long as it does not form a turbulent flow, but is preferably formed by a continuous surface such as a rectangular plate shape, and has a curved surface. You may do it.
[0119]
On the other hand, in a polymerization method toner that associates or fuses resin particles in an aqueous medium, by controlling the flow and temperature distribution of the medium in the reaction vessel at the fusing stage, and further in the shape control step after fusing. By controlling the heating temperature, the number of rotations of stirring, and the time, the shape distribution and shape of the entire toner can be arbitrarily changed.
[0120]
That is, in the polymerization method toner that associates or fuses the resin particles, the flow in the reaction apparatus is made into a laminar flow, and the agitation step and the agitation tank that can make the internal temperature distribution uniform are used. By controlling the temperature, the number of rotations, and the time in the shape control step, it is possible to form a toner having a desired shape factor and uniform shape distribution. The reason for this is that if the laminar flow is fused in a place where the laminar flow is formed, strong stress is not applied to the particles (aggregation or agglomerated particles) in which aggregation and fusion proceed, and in laminar flow where the flow is accelerated It is estimated that this is because the shape distribution of the fused particles becomes uniform as a result of the uniform temperature distribution in the stirring tank. Further, the fused particles gradually become spherical by heating and stirring in the subsequent shape control step, and the shape of the toner particles can be arbitrarily controlled.
[0121]
As the stirring blade and the stirring tank used in the production of the polymerization toner for associating or fusing the resin particles, those similar to the case of forming a laminar flow in the suspension polymerization method described above can be used. 9 can be used. It is characterized in that no obstacle such as a baffle plate that forms a turbulent flow is provided in the stirring tank. As for the configuration of the stirring blade, like the stirring blade used in the above-described suspension polymerization method, the upper stirring blade is disposed with a crossing angle α preceding the lower stirring blade in the rotational direction. In addition, a multistage configuration is preferable.
[0122]
The shape of the stirring blade is not particularly limited as long as it does not form a turbulent flow as long as it does not form a turbulent flow as in the case of forming a laminar flow in the above-described suspension polymerization method. Those formed by a continuous surface, such as a rectangular plate shape, are preferable, and may have a curved surface.
[0123]
The toner of the present invention may be used, for example, as a one-component magnetic toner containing a magnetic material, used as a two-component developer mixed with a so-called carrier, or a non-magnetic toner alone. However, in the present invention, it is preferably used as a two-component developer used by mixing with a carrier.
[0124]
Development method
As described above, in the toner of the present invention, by using a titanate compound as an external additive, the charge amount distribution becomes sharp and the charge imparting ability of the toner itself is improved. The effect can be exhibited by applying to the contact development method.
[0125]
As described above, the amount of adhesion required for color toners can be maintained over a long period, that is, charging can be maintained over a long period of time, and the charge amount distribution required for non-contact development can be kept sharp. Is something that can be done.
[0126]
Here, the developing process by the non-contact developing method will be described.
The non-contact development method is a method in which the developer layer formed on the developer carrying member (developer conveying member) and the photoconductor do not contact each other, and the developer layer is a thin layer in order to constitute this development method. Is preferably formed. In this method, a developer layer having a thickness of 20 to 500 μm is formed in the developing region on the surface of the developer carrying member, and the gap between the photosensitive member and the developer carrying member is larger than the developer layer. The thin layer is formed by a magnetic blade using magnetic force, a method of pressing a developer layer regulating rod on the surface of the developer carrying member, or the like. Further, there is a method of regulating the developer layer by bringing a urethane blade, a phosphor bronze plate or the like into contact with the surface of the developer carrying member. The pressing force of the pressing restricting member is preferably 0.01 to 0.15 N / mm. When the pressing force is small, the regulation force is insufficient, and thus the conveyance is likely to be unstable. On the other hand, when the pressing force is large, the stress on the developer is increased, and the durability of the developer is likely to be lowered. A preferred range is 0.03 to 0.10 N / mm. The gap between the developer carrying member and the photoreceptor surface must be larger than the developer layer. Further, when a developing bias is applied during development, either a method of applying only a DC component or a method of applying an AC bias may be used.
[0127]
In the present invention, it is preferable to apply an alternating electric field between the developer carrying member (developer conveying member) and the electrostatic latent image holding member (photosensitive member). By applying this alternating electric field, it is possible to fly the toner effectively. The conditions for this alternating electric field are preferably that the AC frequency f is 200 to 8000 Hz and the AC voltage Vp-p is 500 to 3000 V. When this alternating electric field is used, it is necessary that the toner has a uniform charging property. That is, when there is a distribution of chargeability between toners, the effect of pulling back weakly chargeable toner or the like due to the alternating electric field is offset, and as a result, the effect of improving image quality is reduced.
[0128]
As the developer carrying member used in the present invention, a member having a magnet built in the carrying member is often used, and the developer carrying surface (sleeve) rotates to convey the developer to the developing area. To do. The sleeve is made of aluminum, aluminum whose surface is oxidized, or stainless steel.
[0129]
The developer carrying member preferably has a diameter of 10 to 40 mm. When the diameter is small, mixing of the developer is insufficient, making it difficult to ensure sufficient mixing to impart sufficient charge to the toner, and when the diameter is large, the centrifugal force on the developer increases. Prone to toner scattering problem.
[0130]
When the toner of the present invention is used in a non-contact developing system, it can be mixed with a carrier and used as a two-component developer, but a magnetic toner containing magnetic powder can be used as a one-component developer. it can.
[0131]
As the carrier constituting the two-component developer, magnetic particles made of conventionally known materials such as metals such as iron, ferrite, and magnetite, and alloys of these metals with metals such as aluminum and lead can be used. Ferrite particles are particularly preferable. The magnetic particles preferably have a volume average particle diameter of 15 to 100 μm, more preferably 25 to 60 μm. The volume average particle diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.
[0132]
The carrier is preferably further coated with a resin, or a so-called resin dispersion type carrier in which magnetic particles are dispersed in the resin. The resin composition for coating is not particularly limited, and for example, olefin resin, styrene resin, styrene / acrylic resin, silicone resin, ester resin, or fluorine-containing polymer resin is used. The resin for constituting the resin-dispersed carrier is not particularly limited, and known resins can be used. For example, a styrene acrylic resin, a polyester resin, a fluorine resin, a phenol resin, or the like can be used. it can.
[0133]
Hereinafter, an example of the non-contact development method will be described with reference to FIG.
FIG. 12 is a schematic view of a non-contact developing type developing unit that can be suitably used in the image forming method of the present invention, wherein 73 is a photosensitive member, 74 is a developer carrier, 75 is a sleeve, 76 is a magnet, and 77 is A two-component developer containing the toner of the present invention, 78 is a developer layer regulating member, 79 is a development region, 80 is a developer layer, and 81 is a power source for forming an alternating electric field.
[0134]
The two-component developer 77 containing the toner of the present invention is carried by the magnetic force of a developer carrier 74 having a magnet 76 therein, and is conveyed to the development region 79 by the movement of the sleeve 75. During the conveyance, the thickness of the developer layer 80 is regulated by the developer layer regulating member 78 so that the developer layer 80 does not come into contact with the photoreceptor 73 in the development region 79.
[0135]
The minimum gap (Dsd) of the development region 79 is larger than the thickness of the developer layer 80 transported to that region (preferably transported by a layer of about 50 to 300 μm), for example, 100 to 1000 μm (preferably 100 to 100 μm). About 500 μm).
[0136]
The power source 81 is a power source for forming an alternating electric field, and preferably an alternating current having a frequency of 200 to 8000 Hz and a voltage of 500 to 3000 Vp-p. The power supply 81 may have a configuration in which direct current is added in series with alternating current as necessary. In that case, the DC voltage is preferably 300 to 800V.
[0137]
When the toner of the present invention is used in contact development, the layer thickness of the developer having the toner of the present invention is 0.1 to 8 mm, particularly 0.4 to 5 mm in the development region. It is preferable. The gap between the photosensitive member and the developer carrying member is preferably 0.15 to 7 mm, particularly preferably 0.2 to 4 mm.
[0138]
Fixing method
A preferred fixing method used in the present invention is a so-called contact heating method. In particular, examples of the contact heating method include a heat pressure fixing method, a heat roller fixing method, and a pressure heating fixing method in which fixing is performed by a rotating pressure member including a fixedly arranged heating body.
[0139]
In the heat roller fixing method, in many cases, an upper roller having a heat source inside a metal cylinder composed of iron, aluminum or the like whose surface is coated with tetrafluoroethylene or polytetrafluoroethylene-perfluoroalkoxy vinyl ether copolymers, etc. And a lower roller made of silicone rubber or the like. A typical example of the heat source is one having a linear heater and heating the surface temperature of the upper roller to about 120 to 200 ° C. In the fixing unit, pressure is applied between the upper roller and the lower roller, and the lower roller is deformed to form a so-called nip. The nip width is 1 to 10 mm, preferably 1.5 to 7 mm. The fixing linear velocity is preferably 40 mm / sec to 600 mm / sec. If the nip is narrow, heat cannot be uniformly applied to the toner, and uneven fixing occurs. On the other hand, when the nip width is wide, the melting of the resin is promoted, and the problem of excessive fixing offset occurs.
[0140]
A fixing cleaning mechanism may be provided for use. As this method, a method of supplying silicone oil to the upper roller or film for fixing, or a method of cleaning with a pad, roller, web or the like impregnated with silicone oil can be used.
[0141]
Next, a method for fixing by a rotating pressure member including a fixedly arranged heating body used in the present invention will be described.
[0142]
This fixing method is a method in which pressure fixing is performed by a fixedly arranged heating body and a pressure member that is in pressure-contact with the heating body and that closely contacts the recording material with the heating body through a film.
[0143]
In this press-contact fixing device, the heating body has a smaller heat capacity than a conventional heating roller, and has a line-shaped heating section in a direction perpendicular to the passing direction of the recording material. 300 ° C.
[0144]
Note that pressure contact fixing is a method in which an unfixed toner image is pressed against a heating source and fixed, such as a method in which a recording material with unfixed toner is passed between a heating member and a pressure member as is usually used. is there. In this way, since heating is performed quickly, the fixing speed can be increased. However, temperature control is difficult, and the toner remains attached to a portion directly pressed against unfixed toner such as a surface portion of the heating source. There are also problems that toner offset is likely to occur, and that the recording material is likely to break down such as winding around the fixing device.
[0145]
In this fixing method, the low-heat capacity line-shaped heating element fixedly supported by the apparatus has a thickness of 0.2 to 5.0 mm, more preferably 0.5 to 3.5 mm, a width of 10 to 15 mm, and a longitudinal length. A 240-400 mm alumina substrate is coated with a resistance material at 1.0-2.5 mm and is energized from both ends.
[0146]
The energization is a pulse waveform with a period of 15 to 25 msec with a DC of 100 V, and is changed to a pulse width corresponding to the temperature / energy release amount controlled by the temperature sensor. In the low heat capacity line-shaped heating element, when the temperature T1 is detected by the temperature sensor, the surface temperature T2 of the film facing the resistance material is lower than T1. Here, T1 is preferably 120 to 220 ° C, and the temperature of T2 is preferably 0.5 to 10 ° C lower than the temperature of T1. Further, the film material surface temperature T3 at the portion where the film peels from the toner surface is substantially equal to T2. The film moves in the direction of the center arrow in FIG. 13 (a) in contact with the heating body whose energy and temperature are controlled in this way. What is used as these fixing films is a heat-resistant film having a thickness of 10 to 35 μm, such as polyester, polyperfluoroalkoxy vinyl ether, polyimide, polyetherimide, and in many cases, a conductive material is added to fluororesin such as Teflon. It is an endless film in which a release agent layer is coated by 5 to 15 μm.
[0147]
For driving the film, a driving force and tension are applied by a driving roller and a driven roller, and the film is transported in the direction of the arrow without wrinkles or twists. The linear velocity as the fixing device is preferably 40 to 600 mm / sec.
[0148]
The pressure roller has a rubber elastic layer having high releasability, such as silicone rubber, and is pressure-bonded to the heating body via a film material with a total pressure of 2 to 30 kg, and rotates by pressure.
[0149]
Moreover, although the example using an endless film was demonstrated above, as shown in FIG.13 (b), you may use the film material of a end using the delivery axis | shaft and take-up axis | shaft of a film sheet. Furthermore, it may be a simple cylinder having no driving roller or the like inside.
[0150]
The fixing device may be used with a cleaning mechanism. As a cleaning method, a method of supplying various silicone oils to the fixing film, or a method of cleaning with a pad, roller, web or the like impregnated with various silicone oils is used.
[0151]
As the silicone oil, polydimethylsiloxane, polymethylphenylsiloxane, polydiphenylsiloxane, or the like can be used. Furthermore, siloxane containing fluorine can also be suitably used.
[0152]
Next, FIG. 13 shows an example of a sectional view of the fixing device.
In FIG. 13 (a), 84 is a low heat capacity line-shaped heating element fixedly supported by the apparatus. As an example, a resistance material 86 is applied to an alumina substrate 85 having a height of 1.0 mm, a width of 10 mm, and a longitudinal length of 240 mm. Is applied to a width of 1.0 mm and is energized from both ends in the longitudinal direction.
[0153]
The energization is, for example, DC100V and is usually a pulse waveform with a cycle of 20 msec, and is controlled by a signal from the temperature measuring element 87 and kept at a predetermined temperature. For this reason, the pulse width is changed according to the amount of energy released, and the range is, for example, 0.5 to 5 msec.
[0154]
The recording material 94 carrying the unfixed toner image 93 is brought into contact with the heating body 84 controlled in this way through the film 88 to thermally fix the toner.
[0155]
The film 88 used here moves without wrinkles while being tensioned by the driving roller 89 and the driven roller 90. Reference numeral 95 denotes a pressure roller having a rubber elastic layer formed of silicone rubber or the like, and pressurizes the heating body through a film with a total pressure of 40 to 200 N. The unfixed toner image 93 on the recording material 94 is guided to the fixing unit by the entrance guide 96, and a fixed image is obtained by the heating described above.
[0156]
The endless belt has been described above. However, as shown in FIG. 13B, the film sheet feeding shaft 91 and the take-up shaft 92 are used, and the fixing film may be a terminal film.
[0157]
【Example】
Next, embodiments of the present invention will be described more specifically with reference to examples. However, the embodiment of the present invention is not limited to this.
[0158]
(Colored particle production example 1: Example of emulsion polymerization association method)
0.90 kg of sodium n-dodecyl sulfate and 10.0 liters of pure water were added and dissolved by stirring. To this solution, 1.20 kg of Legal 330R (Cabot Black Carbon Black) was gradually added and stirred well for 1 hour, followed by continuous dispersion for 20 hours using a sand grinder (medium disperser). This is referred to as “colorant dispersion 1”.
[0159]
A solution composed of 0.055 kg of sodium dodecylbenzenesulfonate and 4.0 liters of ion-exchanged water is referred to as “anionic surfactant solution A”.
[0160]
A solution composed of 0.014 kg of nonylphenol polyethylene oxide 10 mol adduct and 4.0 liters of ion-exchanged water is referred to as “nonionic surfactant solution B”.
[0161]
A solution obtained by dissolving 223.8 g of potassium persulfate in 12.0 liters of ion-exchanged water is referred to as “initiator solution C”.
[0162]
A GL (glass lining) reaction kettle with a volume of 100 liters equipped with a temperature sensor, a condenser tube, and a nitrogen introducing device was added to a WAX emulsion (a polypropylene emulsion having a number average molecular weight of 3000: number average primary particle size = 120 nm / solid content concentration = 29. 9%) 3.41 kg, the total amount of “anionic surfactant solution A” and the total amount of “nonionic surfactant solution B” were added, and stirring was started. Subsequently, 44.0 liters of ion exchange water was added.
[0163]
Heating was started, and when the liquid temperature reached 75 ° C., the entire amount of “initiator solution C” was added dropwise. Thereafter, while controlling the liquid temperature at 75 ° C. ± 1 ° C., 12.1 kg of styrene, 2.88 kg of n-butyl acrylate, 1.04 kg of methacrylic acid, and 548 g of t-dodecyl mercaptan were added dropwise. After completion of the dropwise addition, the liquid temperature was raised to 80 ° C. ± 1 ° C. and stirring was performed for 6 hours. Subsequently, the liquid temperature was cooled to 40 ° C. or less, stirring was stopped, and filtration was performed with a pole filter to obtain a latex. This is designated as “Latex-A”.
[0164]
In addition, the glass transition temperature of the resin particles in Latex-A was 57 ° C., the softening point was 121 ° C., the molecular weight distribution was weight average molecular weight = 12,000, and the mass average particle size was 120 nm.
[0165]
A solution obtained by dissolving 0.055 kg of sodium dodecylbenzenesulfonate in 4.0 liters of ion-exchanged pure water is referred to as “anionic surfactant solution D”.
[0166]
Further, a solution obtained by dissolving 0.014 kg of nonylphenol polyethylene oxide 10 mol adduct in 4.0 liters of ion-exchanged water is referred to as “nonionic surfactant solution E”.
[0167]
A solution obtained by dissolving 200.7 g of potassium persulfate (manufactured by Kanto Chemical Co., Ltd.) in 12.0 liters of ion-exchanged water is referred to as “initiator solution F”.
[0168]
A 100-liter GL reaction kettle equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a comb-shaped baffle was added to a WAX emulsion (a polypropylene emulsion having a number average molecular weight of 3000: number average primary particle size = 120 nm / solid content concentration = 29.9%). ) 3.41 kg, the total amount of “anionic surfactant solution D” and the total amount of “nonionic surfactant solution E” were added, and stirring was started.
[0169]
Next, 44.0 liters of ion exchange water was added. Heating was started, and when the liquid temperature reached 70 ° C., “initiator solution F” was added. Subsequently, a solution prepared by previously mixing 11.0 kg of styrene, 4.00 kg of n-butyl acrylate, 1.04 kg of methacrylic acid, and 9.02 g of t-dodecyl mercaptan was dropped. After completion of the dropwise addition, the liquid temperature was controlled at 72 ° C. ± 2 ° C., and the mixture was heated and stirred for 6 hours. Furthermore, the liquid temperature was raised to 80 ° C. ± 2 ° C., and the mixture was heated and stirred for 12 hours. The liquid temperature was cooled to 40 ° C. or lower and stirring was stopped. The filtrate is filtered through a pole filter, and this filtrate is designated as “Latex-B”.
[0170]
The glass transition temperature of the resin particles in Latex-B was 58 ° C., the softening point was 132 ° C., the molecular weight distribution was weight average molecular weight = 245,000, and the mass average particle size was 110 nm.
[0171]
A solution obtained by dissolving 5.36 kg of sodium chloride as a salting-out agent in 20.0 liters of ion exchange water is referred to as “sodium chloride solution G”.
[0172]
A solution obtained by dissolving 1.00 g of a fluorine-based nonionic surfactant in 1.00 liter of ion-exchanged water is referred to as “nonionic surfactant solution H”.
[0173]
A 100-liter SUS reaction kettle equipped with a temperature sensor, a cooling pipe, a nitrogen introduction device, a particle size and shape monitoring device (reaction device having the configuration shown in FIG. 9, crossing angle α is 25 °) was prepared as described above. 20.0 kg of Latex-A, 5.2 kg of Latex-B, 0.4 kg of Colorant Dispersion 1 and 20.0 kg of ion-exchanged water were added and stirred. Next, the mixture was heated to 40 ° C., and sodium chloride solution G, isopropanol (manufactured by Kanto Chemical Co.) 6.00 kg, and nonionic surfactant solution H were added in this order. Then, after standing for 10 minutes, the temperature rise was started, the temperature was raised to a liquid temperature of 85 ° C. in 60 minutes, and the particles were heated and stirred at 85 ± 2 ° C. for 0.5 to 3 hours while salting out / fusion. Diameter growth. Next, 2.1 liters of pure water was added to stop the particle size growth.
[0174]
The fused particle dispersion prepared above was placed in a 5-liter reaction vessel (reaction apparatus having the configuration shown in FIG. 9, crossing angle α is 20 °) equipped with a temperature sensor, a cooling pipe, and a particle size and shape monitoring device. 5.0 kg was added, and the shape was controlled by heating and stirring at a liquid temperature of 85 ° C. ± 2 ° C. for 0.5 to 15 hours. Then, it cooled to 40 degrees C or less, and stopped stirring. Next, using a centrifugal separator, classification is performed in the liquid by a centrifugal sedimentation method, followed by filtration through a sieve having an opening of 45 μm, and this filtrate is used as an association liquid. Next, using a Nutsche, non-spherical particles in the form of wet cake were collected from the associated liquid by filtration. Thereafter, it was washed with ion exchange water. The non-spherical particles were dried at an intake air temperature of 60 ° C. using a flash jet dryer, and then dried at a temperature of 60 ° C. using a fluidized bed dryer to obtain colored particles.
[0175]
In the monitoring of the salting-out / fusion stage and the shape control process, by controlling the number of revolutions of stirring and the heating time, the coefficient of variation of the shape and the shape factor is controlled, and further the particle size and particle size distribution by subclassification in the liquid. The Bk colored particles 1 to 5 having the shape characteristics and particle size distribution characteristics shown in Table 2 were obtained.
[0176]
(Colored particle production example 2: Example of emulsion polymerization association method)
In Colored Particle Production Example 1, the colorant was replaced by C.I. I. Y colored particles 1 to 5 were obtained in the same manner except that 1.05 kg of Solvent Yellow 93 was used.
[0177]
(Colored particle production example 3: Example of emulsion polymerization association method)
In Colored Particle Production Example 1, the colorant was replaced by C.I. I. M colored particles 1 to 5 were obtained in the same manner except that 1.20 kg of Pigment Red 122 was used.
[0178]
(Colored particle production example 4: Example of emulsion polymerization association method)
In Colored Particle Production Example 1, the colorant was replaced by C.I. I. C colored particles 1 to 5 were obtained in the same manner except that 0.60 kg of CI Pigment Blue 15: 3 was used.
[0179]
(Colored particle production example 5: Example of suspension polymerization method)
Styrene = 165 g, n-butyl acrylate = 35 g, carbon black = 15 g, di-t-butyl salicylic acid metal compound = 2 g, styrene-methacrylic acid copolymer = 8 g, paraffin wax (mp = 70 ° C.) = 20 g at 60 ° C. And stirred with a sand grinder to obtain a mixture. To this was added 2,2′-azobis (2,4-valeronitrile) = 10 g as a polymerization initiator and dissolved therein to prepare a polymerizable monomer composition. Next, 450 g of 0.1 M sodium phosphate aqueous solution was added to 710 g of ion exchange water, and 68 g of 1.0 M calcium chloride was gradually added while stirring at 13,000 rpm with a TK homomixer to prepare a suspension in which tricalcium phosphate was dispersed. did. The polymerizable monomer composition was added to this suspension, and stirred at 10,000 rpm for 20 minutes with a TK homomixer to granulate the polymerizable monomer composition. Then, the reaction apparatus (crossing angle (alpha) is 45 degrees) of the structure as shown in FIG. 2 was made to react at 75-95 degreeC for 5 to 15 hours. Tricalcium phosphate was dissolved and removed with hydrochloric acid, and then classified in the liquid by centrifugal sedimentation using a centrifugal separator, and then filtered, washed and dried to obtain colored particles.
[0180]
Monitoring is performed during the polymerization, and the variation coefficient of the shape and shape factor is controlled by controlling the liquid temperature, the number of rotations of stirring, and the heating time. Furthermore, the variation coefficient of the particle size and particle size distribution is arbitrarily determined by classification in the liquid. To obtain Bk colored particles 6 to 8 having specific shape characteristics and particle size distribution characteristics.
[0181]
(Colored particle production example 6: Example of suspension polymerization method)
In Colored Particle Production Example 5, the colorant is C.I. I. Y colored particles 6 to 8 were obtained in the same manner except that 13 g of Solvent Yellow 162 was used.
[0182]
(Colored Particle Production Example 7: Example of Suspension Polymerization Method)
In Colored Particle Production Example 5, the colorant is C.I. I. M colored particles 6 to 8 were obtained in the same manner except that 18 g of Pigment Red 122 was used.
[0183]
(Colored particle production example 8: Example of suspension polymerization method)
In Colored Particle Production Example 5, the colorant is C.I. I. C colored particles 6 to 8 were obtained in the same manner except that 15 g of Pigment Blue 15: 3 was used.
[0184]
(Colored particle production example 9: Example of suspension polymerization method)
In the colored particle production examples 5 to 8, the reaction apparatus having the configuration as shown in FIG. 9 (crossing angle α is 15 °) was used, and the classification in liquid using a centrifuge was not performed. Similarly, Bk colored particles 9, Y colored particles 9, M colored particles 9 and C colored particles 9 having specific shape characteristics and particle size distribution characteristics were obtained.
[0185]
(Colored particle production example 10: Example of pulverization method)
A toner raw material consisting of 100 parts by mass of styrene-nbutyl acrylate copolymer resin, 10 parts by mass of carbon black and 4 parts by mass of polypropylene is premixed with a Henschel mixer, melted and kneaded with a twin screw extruder, and placed in a hammer mill. The resulting powder was dispersed in a hot air stream of a spray dryer (at 200 to 300 ° C. for 0.05 seconds) to obtain particles whose shape was adjusted. The particles were repeatedly classified with an air classifier until the desired particle size distribution was obtained, to obtain colored particles.
[0186]
In this manner, Bk colored particles 10 to 11 having specific shape characteristics and particle size distribution characteristics, in which the variation coefficient of the shape and the shape factor was controlled and the variation coefficient of the particle size and the particle size distribution were adjusted, were obtained.
[0187]
(Colored particle production example 11: Example of pulverization method)
In the colored particle production example 10, the colorant is C.I. I. Y colored particles 10 to 11 were obtained in the same manner except that 5 parts by mass of Solvent Yellow 93 was used.
[0188]
(Colored Particle Production Example 12: Example of Grinding Method)
In the colored particle production example 10, the colorant is C.I. I. M colored particles 10 to 11 were obtained in the same manner except that 8 parts by mass of Pigment Red 122 was used.
[0189]
(Colored particle production example 13: Example of grinding method)
In Colored Particle Production Example 5, the colorant is C.I. I. C colored particles 10 to 11 were obtained in the same manner except that 8 parts by mass of Pigment Blue 15: 3 was used.
[0190]
Shape factor of each colored particle of Bk colored particles 1 / Y colored particles 1 / M colored particles 1 / C colored particles 1 to Bk colored particles 11 / Y colored particles 11 / M colored particles 11 / C colored particles 11 produced above. Etc. are shown in Tables 1 and 2 below.
[0191]
[Table 1]

[0192]
[Table 2]

[0193]
Next, an external additive is added to each of Bk colored particles 1 / Y colored particles 1 / M colored particles 1 / C colored particles 1 to Bk colored particles 11 / Y colored particles 11 / M colored particles 11 / C colored particles 11. The corresponding toners 1 to 12 were prepared by addition.
[0194]
[Table 3]

[0195]
[Table 4]

[0196]
* Srotonium titanate 1: number average primary particle size = 350 nm
* Srotonium titanate 2: Number average primary particle size = 125 nm
* Slototium titanate 3: number average primary particle size = 400 nm
* Silica 1: hydrophobic silica treated with dichlorodimethylsilane and having a number average primary particle size of 12 nm (hydrophobic degree = 62)
[Manufacture of developer]
Each of Bk toner 1 / Y toner 1 / M toner 1 / C toner 1 to Bk toner 12 / Y toner 12 / M toner 12 / C toner 12 is mixed with a 45 μm ferrite carrier coated with a silicone resin, and the toner density is mixed. 5% by mass of a developer was prepared. Corresponding to the toner, these developers are Bk developer 1 / Y developer 1 / M developer 1 / C developer 1 to Bk developer 12 / Y developer 12 / M developer 12 / C developer 12 and To do.
[0197]
[Evaluation (Non-contact development method)]
For the evaluation, a color printer “Konica KL2010” manufactured by Konica Corporation was modified and used. The conditions are shown below. As the photoconductor, a laminated organic photoconductor was used.
[0198]
-Photoconductor surface potential = -750V
・ DC bias = -610V
AC bias = Vp-p: 2700V
・ Alternating electric field frequency = 5000 Hz
・ Dsd = 570 μm
・ Pressure regulation force = 0.10 N / mm
・ Pressing restriction bar = SUS416 (made of magnetic stainless steel) / diameter 3mm
・ Developer layer thickness = 150μm
・ Development sleeve = 20mm
A pressure contact type heat fixing device was adopted as the fixing device.
[0199]
In the following, Examples 1 to 4, 6-7, 9 As a comparative example 1, a developer combination is shown.
[0200]
[Table 5]

[0201]
〔Evaluation methods〕
Using the developer combination described above, using the above-described evaluation machine, using an image with a pixel ratio of 15% in all colors in a high temperature and high humidity environment (30 ° C., 80% RH), 20,000 sheets Printing evaluation was performed. The evaluation shown below was performed at the initial stage and after 20,000 sheets, and the presence or absence of fluctuation was confirmed.
[0202]
As an image, a 10% halftone image, 2 dot lines, white paper, and a secondary color image (RGB) were output after the initial and 20,000 sheets.
[0203]
(1) 10% dot density
For a 10% halftone dot image portion of 20 mm × 20 mm, the relative image density with respect to the white background portion was measured using a Macbeth reflection densitometer “RD-918”.
[0204]
The evaluation of the 10% halftone dot density is performed for evaluating dot reproducibility and halftone reproducibility. If the density change is within 0.10, the change in image quality is small and there is no problem.
[0205]
This evaluation was performed only for the Bk developer.
(2) Line width
The line width of the line image corresponding to the image signal of 2 dot lines was measured by a print evaluation system “RT2000” (manufactured by Yarman).
[0206]
If the line width of the first formed image and the line width of the 20,000th formed image are both 200 μm or less and the change in the line width is less than 10 μm, fine line reproducibility is not a problem. I can say that. This evaluation was performed only for the Bk developer.
[0207]
(3) fog density
About the blank paper which is not printed, the absolute image density of 20 places is measured using the Macbeth reflection densitometer “RD-918”, and averaged to obtain the blank paper density. Next, the absolute image density at 20 locations was similarly measured and averaged for the white background portion of the evaluation formed image, and the value obtained by subtracting the white paper density from this average density was evaluated as the fog density.
[0208]
If the fog concentration is 0.010 or less, it can be said that fog is practically no problem.
(4) Color difference
The color of the solid image portion of the secondary color (red, blue, green) in each of the first formed image and the 20,000th formed image was measured by “Macbeth Color-Eye 7000”, and CMC (2: 1) The color difference was calculated using the color difference formula.
[0209]
If the color difference obtained by the CMC (2: 1) color difference formula is 5 or less, it can be said that the change in the color of the formed image is acceptable.
[0210]
The secondary color of the color toner was evaluated by forming an image with the combination of toners shown in Table 5.
[0211]
[Table 6]

[0212]
[Table 7]

[0213]
As described above, according to the image formation performed, those in the present invention have excellent image quality, little change in image quality even with repeated image formation, and a small secondary color difference.
[0214]
【The invention's effect】
According to the present invention, it is possible to provide a toner for developing an electrostatic charge image that is excellent in developability and fine line reproducibility and can stably form a high-quality image over a long period of time.
[0215]
In addition, it is possible to provide an image forming method that is excellent in developability and fine line reproducibility and can stably form a high-quality image over a long period of time.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory view showing a reaction apparatus having a single-stage stirring blade.
FIG. 2 is a perspective view showing an example of a reaction apparatus equipped with a stirring blade that can be preferably used.
FIG. 3 is a cross-sectional view of the reaction apparatus shown in FIG.
FIG. 4 is a perspective view showing a specific example of a reactor equipped with a stirring blade that can be preferably used.
FIG. 5 is a perspective view showing a specific example of a reactor equipped with a stirring blade that can be preferably used.
FIG. 6 is a perspective view showing a specific example of a reactor equipped with a stirring blade that can be preferably used.
FIG. 7 is a perspective view showing a specific example of a reactor equipped with a stirring blade that can be preferably used.
FIG. 8 is a perspective view showing a specific example of a reactor equipped with a stirring blade that can be preferably used.
FIG. 9 is a perspective view showing an example of a reaction apparatus used when a laminar flow is formed.
FIG. 10 is a schematic view showing a specific example of the shape of a stirring blade.
FIGS. 11A and 11B are explanatory diagrams showing projected images of toner particles having no corners, and FIGS. 11B and 11C are explanatory diagrams showing projected images of toner particles having corners, respectively. FIGS.
FIG. 12 is an explanatory diagram illustrating an example of a developing device using a non-contact developing method.
FIG. 13 is an explanatory diagram illustrating an example of a configuration of a fixing device.
[Explanation of symbols]
1 Heat exchange jacket
2 Mixing tank
3 Rotating shaft
4 Stirring blade
40, 41, 42, 43, 44, 45, 46 Stirrer blades located in the lower stage
411, 422, 431, 441 Bending part
421 slit
423,432,442,511 fins
50, 51, 52, 53, 54, 56, 65 Stirrer blades located in the upper stage
55 Stirring blades located in the middle
5a, 5b, 5c, 5d stirring blade
6b, 6c, 6d
α crossing angle
73 photoconductor
74 Developer carrier
75 sleeve
76 magnet
77 Two-component developer
78 Developer layer regulating member
79 Development Area
80 Developer layer
81 power supply
84 Heating body
85 Alumina substrate
86 Resistance material
87 Thermometer
88 films
89 Driving roller
90 Followed roller
91 Feed axis
92 Winding shaft
93 Unfixed toner image
94 Recording material
95 Pressure roller
Dsd minimum gap

Claims (34)

In an electrostatic charge image developing toner containing at least toner particles composed of a resin and a colorant and an external additive, the variation coefficient of the shape factor of the toner particles is 16% or less, and the number variation in the number particle size distribution Titanium having a coefficient of 27% or less, a ratio of toner particles having a shape factor in the range of 1.2 to 1.6 is 65% by number or more, and the external additive has a number average primary particle size of 100 to 2000 nm. An electrostatic charge image developing toner comprising an acid compound in an amount of 0.3 to 5.0% by mass based on the toner. 2. The electrostatic image developing toner according to claim 1, wherein the proportion of toner particles having no corners is 50% by number or more. 3. The electrostatic image developing toner according to claim 1, wherein the number average particle diameter of the toner particles is 3 to 8 [mu] m. When the particle size of the toner particles is D (μm), the natural logarithm lnD is taken on the horizontal axis, and the horizontal axis is divided into a plurality of classes at intervals of 0.23 to the most frequent class in the histogram showing the number-based particle size distribution. The sum (M) of the relative frequency (m1) of the toner particles contained and the relative frequency (m2) of the toner particles contained in the next most frequent class is 70% or more. The toner for developing an electrostatic charge image according to any one of claims 1 to 3. 5. The electrostatic image developing toner according to claim 1, wherein the toner is obtained by polymerizing at least a polymerizable monomer in an aqueous medium. The toner for developing an electrostatic charge image according to any one of claims 1 to 5, wherein the toner is obtained by associating at least resin particles in an aqueous medium. In the electrostatic image developing toner comprising at least toner particles composed of a resin and a colorant and an external additive, the ratio of the toner particles having no corners of the toner particles is 50% by number or more, and the number variation coefficient in the number particle size distribution Is 27% or less, the proportion of toner particles having a shape factor in the range of 1.2 to 1.6 is 65% by number or more, and the external additive has a number average primary particle size of 100 to 2000 nm. A toner for developing an electrostatic charge image, comprising 0.3 to 5.0% by mass of a compound based on the toner. The toner for developing an electrostatic charge image according to claim 7, wherein the number average particle diameter of the toner particles is 3 to 8 μm. When the particle size of the toner particles is D (μm), the natural logarithm lnD is taken on the horizontal axis, and the horizontal axis is divided into a plurality of classes at intervals of 0.23 to the most frequent class in the histogram showing the number-based particle size distribution. The sum (M) of the relative frequency (m1) of the toner particles contained and the relative frequency (m2) of the toner particles contained in the next most frequent class is 70% or more. The toner for developing an electrostatic charge image according to claim 7 or 8. 10. The electrostatic image developing toner according to claim 7, wherein the toner is obtained by polymerizing at least a polymerizable monomer in an aqueous medium. The toner for developing an electrostatic charge image according to any one of claims 7 to 10, wherein the toner is obtained by associating at least resin particles in an aqueous medium. In the electrostatic image developing toner comprising at least toner particles composed of a resin and a colorant and an external additive, the ratio of the toner particles having a shape factor in the range of 1.2 to 1.6 is 65% by number or more. The toner particles have a coefficient of variation of 16% or less, and the external additive contains a titanic acid compound having a number average primary particle size of 100 to 2000 nm in an amount of 0.3 to 5.0% by mass based on the toner. A toner for developing an electrostatic charge image. The electrostatic image developing toner according to claim 12, wherein the proportion of toner particles having no corners is 50% by number or more. The electrostatic charge image developing toner according to claim 12, wherein the toner particles have a number average particle diameter of 3 to 8 μm. When the particle size of the toner particles is D (μm), the natural logarithm lnD is taken on the horizontal axis, and the horizontal axis is divided into a plurality of classes at intervals of 0.23 to the most frequent class in the histogram showing the number-based particle size distribution. The sum (M) of the relative frequency (m1) of the toner particles contained and the relative frequency (m2) of the toner particles contained in the next most frequent class is 70% or more. The toner for developing an electrostatic charge image according to claim 12, wherein the toner is for developing an electrostatic image. 16. The electrostatic image developing toner according to claim 12, wherein the toner is obtained by polymerizing at least a polymerizable monomer in an aqueous medium. The toner for developing an electrostatic charge image according to any one of claims 12 to 16, wherein the toner is obtained by associating at least resin particles in an aqueous medium. The electrostatic latent image formed on the photosensitive member is opposed to the developer layer formed on the developer conveying member, and the electrostatic image is developed with toner particles composed of at least a resin and a colorant and an external additive. In the image forming method including the developing step of developing with the toner for toner, the toner is a magnetic toner particle having a variation coefficient of shape factor of 16% or less and a number variation coefficient of 27% or less in the number particle size distribution. The ratio of toner particles having a shape factor in the range of 1.2 to 1.6 is 65% by number or more, and the external additive has a number average primary particle size of 100 to 2000 nm as a titanate compound with respect to the toner. And an image forming method characterized in that the toner image is visualized by flying the toner. The image forming method according to claim 18, wherein the image is formed by flying toner having a ratio of toner particles having no corners of 50% by number or more. 20. The image forming method according to claim 18 or 19, wherein the toner particles are visualized by flying a toner having a number average particle diameter of 3 to 8 [mu] m. When the particle size of the toner particles is D (μm), the natural logarithm lnD is taken on the horizontal axis, and the horizontal axis is divided into a plurality of classes at intervals of 0.23 to the most frequent class in the histogram showing the number-based particle size distribution. The toner having a sum (M) of 70% or more of the relative frequency (m1) of the toner particles contained and the relative frequency (m2) of the toner particles contained in the second most frequent class after the most frequent class is allowed to fly. The image forming method according to any one of claims 18 to 20, wherein the image is made visible. The image forming method according to any one of claims 18 to 21, wherein the toner is visualized by flying a toner obtained by polymerizing at least a polymerizable monomer in an aqueous medium. 23. The image forming method according to any one of claims 18 to 22, wherein at least the toner obtained by associating resin particles in an aqueous medium is made to fly and visualized. For electrostatic image development comprising at least toner particles comprising a resin and a colorant and an external additive such that the electrostatic latent image formed on the photoreceptor is opposed to the developer layer formed on the developer conveying member. In an image forming method including a developing step for visualizing with toner, the toner is a toner particle in which the proportion of toner particles having no corners is 50% by number or more and the number variation coefficient in the number particle size distribution is 27% or less. A toner having a toner having a ratio of toner particles having a shape factor in the range of 1.2 to 1.6 of 65% by number or more and the external additive having a number average primary particle size of 100 to 2000 nm. And an image forming method characterized by containing 0.3 to 5.0% by mass and making the toner fly to make a visible image. 25. The image forming method according to claim 24, wherein the toner particles are visualized by flying a toner having a number average particle diameter of 3 to 8 [mu] m. When the particle size of the toner particles is D (μm), the natural logarithm lnD is taken on the horizontal axis, and the horizontal axis is divided into a plurality of classes at intervals of 0.23 to the most frequent class in the histogram showing the number-based particle size distribution. The toner having a sum (M) of 70% or more of the relative frequency (m1) of the toner particles contained and the relative frequency (m2) of the toner particles contained in the second most frequent class after the most frequent class is allowed to fly. 26. The image forming method according to claim 24 or 25, wherein the image is made visible. 27. The image forming method according to any one of claims 24 to 26, wherein at least a polymerizable monomer is polymerized in an aqueous medium to make a toner image visible. 28. The image forming method according to any one of claims 24 to 27, wherein a toner obtained by associating at least resin particles in an aqueous medium is made to fly and visualized. Law. The electrostatic latent image formed on the photosensitive member is opposed to the developer layer formed on the developer conveying member, and the electrostatic image is developed with toner particles composed of at least a resin and a colorant and an external additive. In the image forming method including the developing step of developing with the toner for toner, the toner has a ratio of toner particles having a shape factor in the range of 1.2 to 1.6 of 65% by number or more, and the variation in the shape factor Toner particles having a coefficient of 16% or less, and the external additive contains a titanic acid compound having a number average primary particle size of 100 to 2000 nm with respect to the toner in an amount of 0.3 to 5.0% by mass. An image forming method. 30. The image forming method according to claim 29, wherein the image is formed by flying a toner having a ratio of toner particles having no corners of 50% by number or more. 30. The image forming method according to claim 29, wherein the toner particles are visualized by flying a toner having a number average particle diameter of 3 to 8 [mu] m. When the particle size of the toner particles is D (μm), the natural logarithm lnD is taken on the horizontal axis, and the horizontal axis is divided into a plurality of classes at intervals of 0.23 to the most frequent class in the histogram showing the number-based particle size distribution. The toner having a sum (M) of 70% or more of the relative frequency (m1) of the toner particles contained and the relative frequency (m2) of the toner particles contained in the second most frequent class after the most frequent class is allowed to fly. 32. The image forming method according to claim 29, wherein the image is made visible. 33. The image forming method according to any one of claims 29 to 32, wherein a toner obtained by polymerizing at least a polymerizable monomer in an aqueous medium is made to fly and visualized. 34. The image forming method according to any one of claims 29 to 33, wherein a magnetic toner obtained by associating at least resin particles in an aqueous medium is made to fly and visualized.

Images