JP4062086B2 - Image forming method and image forming apparatus - Google Patents

Description

【０２１４】
[静電荷像現像剤の製造]
得られたトナー粒子１〜１３各５０質量部に対し、疎水性シリカ（ＴＳ７２０：キャボット製）を０．５質量部添加し、サンプルミルにてブレンドした。
このブレンド物を、ポリメチルメタクリレート（総研化学社製）を１質量％コートした体積平均粒径が５０μｍのフエライトキャリアに対し、トナー濃度が５質量％になるように秤量し、ボールミルで５分間攪拌・混合し現像剤１〜１３を調製した。
【０２１５】
[帯電ロールの作製]
導電性支持体としてステンレス製のシャフト（直径：８ｍｍ、長さ：３５０ｍｍ）を用いて、その周囲に中抵抗の弾性体層を以下の配合及び加工方法により形成した。
【０２１６】
・ＧＥＣＯ系エピクロルヒドリン原料ゴム（エピクロマＣＧ１０２：ダイソー製、組成比：エピクロルヒドリン４０ｍｏｌ％、エチレンオキサイド５６ｍｏｌ％、アリルグリシジルエーテル４ｍｏｌ％）１００質量部
・炭酸カルシウム（タマパールＴＲ−２２２Ｈ：奥多摩工業製）３０質量部
・サブ（ネオファクチスＵ−８：天満サブ化工製） １０質量部
・テトラメチルアンモニウムクロライド（日本樹脂製：エレガンスＲ１１５）１．０質量部
・ステアリン酸（脂肪酸ＳＡ−２００：旭電化製）０．５質量部
・加硫促進剤（ノクセラＴＴ：大内新興化学製） １．０質量部
・加硫促進剤（ノクセラＤＭ：大内新興化学製） １．５質量部
・加硫促進剤（バルノックＲ：大内新興化学製） １．０質量部
・加硫剤（サルファックス：鶴見化学製） ０．２５質量部
【０２１７】
上記配合物を混練して均一な組成のコンパウンドとした後、上記ステンレス製シャフトの表面に、一次加硫（蒸気缶、４．５×１０²ｋＰａ、１５０℃×１時間）、２次加硫（１５５℃×７時間）によって、外径１４ｍｍ×長さ３１０ｍｍになるように成形して、ローラ状の中抵抗弾性体層を設けた。この中抵抗弾性体層の電気抵抗は２×１０⁷Ω・ｃｍ、ローラゴム硬度は３８度（ＪＩＳ Ａ）であった。
【０２１８】
次に、直鎖ポリエステル樹脂（バイロン３０ＳＳ：東洋紡（株）製）８０質量部、及びメラミン樹脂（スーパーベッカミンＧ−８２１−６０：大日本インキ（株）製）２０質量部に、導電性カーボン（ＦＷ２００：デグサ社製）５質量部、フッ素樹脂微粉（ルブロンＬ−５：ダイキン工業社製）１０質量部を混合し、サンドミルを用いて、混合分散させた。
【０２１９】
次いで、前記分散物をキシレンで希釈して（分散物１００質量部に対し、キシレン１５０質量部の割合）、表面層形成用塗料を調製し、粘度調整を行った。前記シャフトと弾性体層の端面とが接する部分から膜厚に相当する間隙を残してシャフトをマスキングした後、ベル型静電塗装機（ランズバーグインダストリー社製）を用い、前記中抵抗弾性体層の表面に乾燥時膜厚が３５μｍとなるように、弾性体層の全表面に表面層を形成した後、この表面層を１６０℃で、３０分間乾燥させ、帯電ロールを作製した。
【０２２０】
この帯電ロールに関し、抵抗測定セル（商品名：１６００８Ａ、ＹＨＰ社製）及び抵抗計（商品名：Ｒ８３４０Ａ、アドバンテスト社製）を用いて、印加電圧１００Ｖで体積抵抗を測定した。前記中抵抗弾性層の表面にロールと同様に表面層を設けたシート（帯電ロールの層構成に相当）の体積抵抗は、１０^5.2Ω・ｃｍを示した。また表面層の体積抵抗は１０^4.5Ω・ｃｍであり、帯電ロールと表面層の体積抵抗の差は、０．７桁であった。また、放電絶縁破壊を起こす電圧を測定したところ、２２００Ｖであった。このときの表面被覆率は９５．６％であった。なお、上記表面被覆率は、次の式を用いて算出した。
表面被覆率（％）＝〔（表面層の全表面積）／（帯電ロールの全表面積）〕×１００
【０２２１】
[転写ロールの作製]
２層構成転写ロールを、以下のように作製した。
加硫剤として、硫黄１質量部と、加硫促進剤としてテトラメチルチラウムジサルファイド０．６質量部とを含有するゴム素材（ ＥＰＤＭ ＥＰ３３：日本合成ゴム（株）製）１００質量部に、ケツチエンブラック（ライオンアグゾ（株）製、体積抵抗ρv：１０^6.3Ωｃｍ）１２質量部およびＦＴカーボン（旭カーボン（株）製）２０質量部と、発泡剤としてベンゼンスルホニルヒドラジド６質量部の組成からなる発泡ゴムコンパウンド１５質量部とを加え、ニーダーおよびロール練り機により混練した。
【０２２２】
次いで、この混練物を、押出機でチューブ形状に押出成形し、これを加硫缶内で温度１２６ ℃、 圧力１．５ｋｇ／ｃｍ²Ｇの加圧蒸気下に加熱発泡した。得られた発泡弾性体に、ステンレス製のシャフト（直径：８ｍｍ、長さ：３５０ｍｍ）を挿入し、さらに厚み０．１ｍｍのポリフッ化ビニリデン（ＰＶＤＦ）樹脂にイオン導電性ポリマーを分散してなる熱収縮チューブを、１２０℃にて被覆することにより、層厚が５ｍｍの転写ロールを得た。
【０２２３】
なお、前記発泡弾性体（下地層）の硬度は、アスカーＣ硬度で６０°であり、ロール硬度はアスカーＣ硬度で４０°であった。上記ポリフッ化ビニリデン（ＰＶＤＦ）の体積抵抗率は、１０^8.2Ωｃｍ、表面抵抗は１０^7.5Ω／□ であった。また、イオン導電性ポリマーを分散してなるＰＶＤＦチューブは、ＰＶＤＦ粉末にイオン導電性ポリマーとして、三洋化成工業（株）製のペレスタット６３２１チップを４０質量％混合し、これを二軸押出機で混練しつつペレット化し、これを一軸押出機でチューブ状に延伸しながら押し出し成形を行って得られる。
【０２２４】
＜実施例１＞
評価機として、複写機（Ｌａｓｅｒ Ｗｉｎｄ３３１０：富士ゼロックス社製）改造機を用い、前記帯電ロールを感光体に接触回転するように設置し、そのシャフト（導電性支持体）に電源から、画像形成時のみ７５０ＶのＤＣ電源と２ｋＶで２ｋＨｚのＡＣ電源とを重畳したものを印加するようにした。また、前記転写ロールも同時に設置した。
【０２２５】
上記複写機の現像器に、現像剤として前記現像剤１をセットし、２３℃、５５％ＲＨの環境下で、連続４０００枚の連続走行試験を行った。トナー帯電量維持性、画質、用紙剥離性、転写・帯電ロール汚れ、転写画質での画質欠陥（ホロキャラ、端部白抜け）等を評価した。
【０２２６】
−トナー帯電量維持性−
初期及び走行試験後のトナー帯電量を帯電量測定器ＴＢ２００（東芝社製）により測定し、以下の基準により評価した。
【０２２７】
○：走行試験後の帯電量低下が５μＣ／ｇ未満
△：走行試験後の帯電量低下が５μＣ／ｇ以上１０μＣ／ｇ未満
×：走行試験後の帯電量低下が１０μＣ／ｇ以上
【０２２８】
−画像濃度−
走行試験後の全面ベタ画像を出力し、画像濃度均一性を目視により、以下の基準により評価した。
○：全面均一で問題なし。
△：濃度ムラが見られる。
×：全体的に濃度低下している。
【０２２９】
−かぶり−
走行試験後の白地画像について、目視により以下の基準で評価した。
○：かぶりなし。
△：ややかぶりが見られる。
×：かなりかぶりが見られ品質上問題。
【０２３０】
−粒状性−
走行試験後の中間調画像を出力し、目視により以下の基準で評価した。
○：全面均一で問題なし。
△：ややざらつきが見られる。
【０２３１】
−転写効率−
初期及び走行試験後の転写効率を求め、以下の基準により評価した。なお、転写効率は、ベタ画像について、記録用紙に転写された単位面積当りのトナー量（ＴＭＡ）と、感光体表面に残る未転写の単位面積当りのトナー量（ＤＭＡ）を測定し、以下の式により算出した。
転写効率（％）＝〔（ＴＭＡ）／（ＴＭＡ＋ＤＭＡ）〕×１００
【０２３２】
○：転写効率がほとんど低下しない。
△：転写効率が５％以上１０％未満低下。
×：転写効率が１０％以上低下。
【０２３３】
−ホローキャラクター、白抜け−
走行試験後の細線（英文）画像について、目視により以下の基準で評価した。
○：良好
△：軽微に発生
×：発生
【０２３４】
−ロールの汚れ状態 −
走行試験後の帯電ロール、転写ロールを取り外し、スコッチテープにより表面に付着しているトナーを転写して、目視により以下の基準で評価した。
以上の評価結果を表２に示す。
【０２３５】
＜実施例２〜７、比較例１〜６＞
実施例１において、現像剤１の代わりに、現像剤２〜７を各々用いた以外は実施例１と同様にして実施例２〜７を行った。
また、実施例１において、現像剤１の代わりに、現像剤８〜１３を各々用いた以外は実施例１と同様にして比較例１〜６を行った。
結果をまとめて表２に示す。
【０２３６】
【表２】

【０２３７】
表２の結果に示すように、実施例の現像剤を用いた場合には、トナー帯電性、画質欠陥がほとんどなく、トナー性能として安定しているだけでなく、帯電ロールや転写ロールへの汚染が全くないことがわかった。一方、比較例の現像剤を用いた場合には、トナー性能や上記汚染等に何らかの問題が発生した。特に、粗大顔料粒子量が多い比較例３〜６では、帯電量低下によるかぶり、濃度ムラ、ロール汚染や転写効率低下、画像欠陥が発生しており、著しく劣る結果となった。
【０２３８】
【発明の効果】
本発明によれば、環境安定性や繰り返し安定性に優れ、良好な帯電性能、転写性能を有し、高画質と高信頼性とを同時に満足し得る画像形成方法、画像形成装置を提供することができる。
【図面の簡単な説明】
【図１】 本発明の画像形成装置の一例である電子写真装置を示す模式断面図である。
【符号の説明】
１ 静電潜像担持体
２ クリーニングブレード
３ 保持部材
１０ 電子写真感光体（静電潜像担持体）
１１ 帯電器（帯電手段）
１２ 電源
１３ 画像入力器（静電潜像形成手段）
１４ 現像器（現像手段）
１５ 転写器（転写手段）
１６ クリーニング器（クリーニング手段）
１７ 除電器
１８ 定着器
１９ ブレード（クリーニングブレード）
２０ 被記録体
２１ 箱体[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming method and an image forming apparatus using an electrophotographic method or an electrostatic recording method.
[0002]
[Prior art]
A method for visualizing image information through an electrostatic latent image, such as electrophotography, is currently used in various fields. In electrophotography, an electrostatic latent image is formed on the surface of a photoreceptor (electrostatic latent image carrier) by charging and exposure processes, and electrostatic charge image developing toner (hereinafter sometimes simply referred to as “toner”). The electrostatic latent image is developed with an electrostatic charge image developer (hereinafter sometimes simply referred to as “developer”), and visualized through a transfer and fixing process.
[0003]
In the charging process in this electrophotographic process, the photosensitive member is conventionally charged by corona discharge generated by applying a high voltage to a metal wire. However, in this method, ozone, NOx, etc. are generated when corona discharge occurs. In addition, the surface of the photoconductor is altered to cause image blurring and black streaks, and the charging efficiency is poor. For this reason, in recent years, many methods have been devised in which the photosensitive member is directly charged instead of such charging by corona discharge. Among them, the charging roll (charging member) is in a stable contact state with the photosensitive member, the occurrence of pinhole leakage is suppressed, and the state of forming a leaving nip is stable.
[0004]
The charging roll used for the contact charging method has a medium resistance on the outer periphery of a core metal such as conductive stainless steel or Ni-plated metal.^Four-10⁹An elastic body of Ω · cm is arranged. The reason why the elastic body is made to have a medium resistance is to improve charging efficiency and prevent a charging failure from occurring due to a voltage drop due to a charging current leak to the photoreceptor defect.
[0005]
A contact charging device using a charging roll is used in contact with a photosensitive member as a member to be charged, and a direct current voltage and an oscillating voltage are superimposed and applied from the charging device (see, for example, Patent Document 1). However, when a superimposed voltage is applied, toner fusion occurs on the surface of the photoreceptor due to electrical / mechanical vibration caused by the vibration voltage component, and wear on the surface of the photoreceptor is promoted. This causes a problem that the image quality is impaired. Furthermore, when high image quality such as color printing is required, it is necessary to carry out a static elimination process before uniformly charging the photoconductor. In this case, in particular, in a low-temperature and low-humidity environment such as winter, if the superimposed voltage of the DC voltage component and the oscillating voltage component is continuously applied to the contact charging device, the charging capability of the contact charging device is reduced, resulting in image quality defects.
[0006]
In order to solve this problem, a method has been proposed for charging means in which neither a DC voltage nor an oscillating voltage is applied to the charging roll when an image is not formed (see, for example, Patent Document 2). Therefore, the charging performance can be maintained stably for a long time without decreasing.
[0007]
On the other hand, in this type of image forming apparatus, a toner image visualized by developing an electrostatic latent image on the surface of a photosensitive member is electrostatically transferred to a recording material such as a recording paper through an intermediate transfer member. A required reproduced image is obtained by transferring. In particular, in the case of adopting a system in which the toner image formed on the electrostatic latent image carrier is primarily transferred to an intermediate transfer member, and further the toner image on the surface of the intermediate transfer member is secondarily transferred to a recording paper, a conductive bias There is known a bias roll type image forming apparatus in which a recording sheet is pressed against an intermediate transfer member using a roll and an electric field is applied to electrostatically transfer a toner image. A bias roll transfer method for electrostatic transfer while applying a transfer voltage to a conductive bias roll includes a backup roll that receives a pressing force of the bias roll and forms a passage for a transfer current.
[0008]
In a transfer device that uses a metal roll as a bias roll (see, for example, Patent Document 3), the recording paper is pressed against the backup roll by the bias roll via the intermediate transfer member. Thus, the load of the pressing force by the bias roll is concentrated on the secondary transfer portion to be transferred. For this reason, the toner image aggregates and the charge density becomes high, and in some cases, a discharge occurs inside the toner layer to change the toner polarity. Due to such factors, there is a problem in the above-described conventional technique that an image quality defect of a hollow character in which a line image is missing occurs. For the hollow character, the state of the toner particles and the toner layer is also greatly related, and particularly those having a small particle size, indefinite shape, easily causing charge leakage, and those having low insulating properties are easily affected.
[0009]
In addition, the toner remaining on the intermediate transfer member is transferred to the bias roll between the time when the paper passes through the bias roll and the time when the next paper is conveyed to the bias roll, and the bias roll is contaminated. In order to solve this problem, a method of cleaning the bias roll with a cleaning blade or the like, and a method of forming an electric field between the bias roll and the image carrier in the direction in which the toner is transferred to the image carrier at the time of non-transfer However, when the hardness of the bias roll is relatively low, it is difficult to sufficiently exert the scraping action by the cleaning blade. On the other hand, when the bias roll is made of a rubber material having a large friction coefficient, it is not practical for reasons such as damage to the bias roll or an increase in rotational torque due to sliding of the blade. Further, the adhered toner is easily pressed and aggregated by the bias roll. Therefore, a high electric field is required for sufficient cleaning, which is not preferable.
[0010]
In recent years, in this type of image forming apparatus, image quality has been improved and toner diameter has been reduced as one direction for achieving higher image quality. By reducing the diameter, the reproducibility of the dots of the toner image formed on the surface of the latent image carrier can be improved.
[0011]
By the way, as for the toner manufacturing method, if the diameter of the toner is simply reduced by a pulverization method which is one of the toner manufacturing methods that have been widely used in the past, the yield at the time of toner manufacturing is deteriorated. The cost of will become high.
[0012]
Further, the shape of the toner particles produced by the conventional kneading and pulverizing method is indefinite, and the surface composition is not uniform. Although the shape and surface composition of the toner particles vary slightly depending on the pulverization properties of the materials used and the conditions of the pulverization process, it is difficult to control the shape of the intended toner and the surface composition of the toner particles. In particular, when toner particles are manufactured using a material having high pulverization property, fine powder is often generated or a shape is changed due to mechanical force or the like due to a shearing force in the developing device.
[0013]
Due to these effects, in the two-component developer, the finely divided toner particles are fixed to the carrier to accelerate the charging deterioration of the developer, and in the one-component developer, the toner particle size distribution is increased due to the expansion of the toner particle size distribution. The image quality is liable to be deteriorated due to the scattering or the decrease in developability due to the change in the shape of the toner particles.
[0014]
Further, if the toner particle shape is indefinite, the fluidity is not sufficient even when the fluidity aid is added, and the fluidity aid particles are moved into the recesses of the toner particles by mechanical force such as shear force during use. There is a problem that the toner is buried and the fluidity of the toner is lowered over time, and the developing property, the transfer property, and the cleaning property are deteriorated. Further, when such toner is collected by cleaning and returned to the developing unit for use again, image quality is likely to deteriorate. In order to prevent these phenomena, it may be possible to further increase the fluidity aid. However, in this case, there is a problem that black spots are generated on the surface of the photosensitive member or the fluidity aid is scattered. .
[0015]
On the other hand, in the case of a toner internally containing a release agent such as wax, exposure to the release agent on the surface of the toner particles often occurs in combination with a thermoplastic resin. In particular, in the case of a toner in which a resin that is given elasticity by a high molecular weight component and is not easily pulverized is combined with a brittle wax such as polyethylene, polyethylene is often exposed on the surface of the toner particles. Such toner is advantageous for releasability at the time of fixing and cleaning of untransferred toner from the photoreceptor, but the polyethylene on the surface of the toner particle is detached from the surface of the toner particle by a shearing force in the developing device. Easily shift to a developing roll, a photoreceptor, a carrier, or the like. Such contamination reduces the reliability as a developer.
[0016]
Under these circumstances, in recent years, there have been attempts to solve the above problems by intentionally controlling the shape and surface composition of the toner particles, and in particular, research on producing toner by a wet method has become active. It was. For example, a resin particle dispersion is prepared by emulsion polymerization or the like, a colorant dispersion in which a colorant is dispersed in an aqueous medium (solvent) is prepared, and both are mixed and heated to form aggregated particles corresponding to the toner particle size. Then, an emulsion polymerization aggregation method has been proposed in which a toner is manufactured by further fusing the aggregated particles by raising the temperature (see, for example, Patent Documents 5 and 6).
[0017]
In recent years, there has been an increasing demand for higher image quality, and in particular, in color image formation, a tendency to reduce the toner diameter and make the particle diameter uniform is remarkable in order to achieve a high-definition image. In general, when an image is formed using a toner having a wide particle size distribution, the toner on the fine powder side in the particle size distribution is contaminated with a developing roll, a charging roll, a charging blade, a transfer roll, an intermediate transfer member, a photosensitive member, a carrier, and the like. The problem of toner scattering has become significant, and it has been difficult to simultaneously achieve high image quality and high reliability.
In addition, a toner with a wide particle size distribution has a wide distribution of chargeability of the toner itself, and problems of fogging and scattering are likely to occur in the development process and the transfer process, and it is difficult to obtain high reliability in these processes. .
[0018]
On the other hand, the toner having a reduced particle size is liable to generate various drools particularly in the transfer process, and hinders high image quality. This is considered to be due to an increase in chemical adhesion force of the toner to the photoreceptor, for example, non-electrostatic adhesion force such as van der Waals force. In order to improve such a problem, it is necessary to appropriately control the adhesive force between the toner and the photoconductor, and for example, it is necessary to control the shape and the surface state.
[0019]
In the conventional kneading and pulverizing method, it is very difficult to produce a toner having a small particle size and a uniform particle size as described above. In principle, the shape distortion increases as the toner has a small particle size. Problems in the process cannot be avoided. Therefore, researches on emulsion polymerization aggregation methods that make it easy to produce a toner having a small diameter and a uniform particle diameter are being actively conducted among wet methods.
[0020]
However, in the case of toner particle preparation by the emulsion polymerization aggregation method, the reaction generally proceeds in the direction of making the irregular toner particles into a smoother spherical toner by heating, that is, in the direction of decreasing the surface area. Therefore, the toner has a principled aspect that the smaller the surface area, that is, the smaller the particle size toner, the higher the sphericity, and the larger the particle size toner, the higher the irregularity. On the other hand, in order to obtain all of toner shape transfer quality, transfer efficiency, toner durability, and the like, optimum design in toner particle shape and particle size distribution is required.
[0021]
On the other hand, as a problem when the contact charging device using the charging roll is used, the charging roll is in contact with the member to be charged (electrostatic latent image carrier) due to the principle of the contact charging device. Dirt and foreign matter on the surface of the body to be charged migrate to and easily accumulate into a contaminated state, and if the contamination state exceeds the allowable level, the object to be charged cannot be charged to a desired potential or uneven charging occurs. For example, the charging performance is lowered. In particular, when the toner having a small particle diameter for obtaining the high-definition color image is used, there is a problem that the charging roll is extremely contaminated and a desired uniform charge cannot be obtained.
[0022]
Even when a transfer roll is used, dirt and foreign matter on the surface of the transfer medium such as the photoconductor and intermediate transfer body migrate, and the accumulation tends to cause contamination, and transfer current leakage occurs when contamination exceeds the allowable level. However, there has been a problem that uniform transfer cannot be obtained. Also. When the toner insulating property is low and the particle size and shape distribution are wide, there is a problem that the hollow character is deteriorated.
[0023]
[Patent Document 1]
Japanese Patent Laid-Open No. 1-073364
[Patent Document 2]
JP 2000-352857 A
[Patent Document 3]
Japanese Patent Laid-Open No. 06-095521
[Patent Document 4]
Japanese Patent Laid-Open No. 06-095521
[Patent Document 5]
JP-A-63-282749
[Patent Document 6]
JP-A-6-250439
[0024]
[Problems to be solved by the invention]
The object of the present invention is to solve the above-mentioned problems of the prior art.
That is, the present invention provides an image forming method and an image forming apparatus that are excellent in environmental stability and repetitive stability, have good charging performance and transfer performance, and can simultaneously satisfy high image quality and high reliability. Objective.
[0025]
[Means for Solving the Problems]
  The above-mentioned subject is achieved by the following present invention. That is, the present invention
<1> ChargingrollThe electrostatic latent image carrying member to be charged by applying a voltage from the outside and charging, an electrostatic latent image forming step for forming an electrostatic latent image, and developing the electrostatic latent image into an electrostatic image development A toner image forming step for developing an image using an agent, wherein the electrostatic charge image developer has the following conditions (a), (b), (c), (d), And an electrostatic image developing toner satisfying (e).
[0026]
(A) The volume average particle size D50v of the toner is in the range of 3 to 10 μm, and the volume average particle size distribution index GSDv and the number average particle size distribution index GSDp are both 1.25 or less.
(B) The particle size ratio of the number particle size distribution index GSDp-under on the small particle size side is 1.27 or less and the particle size of the particle size of 3/5 or less of the number average particle size D50n is 10% by number or less, and the volume average particle size The ratio of particles having a particle size of at least twice D50v is 10% by volume or less.
(C) The average circularity is in the range of 0.940 to 0.980, and the average circularity standard deviation is 0.1 or less.
(D) The number of aggregates of pigment particles having a maximum length of 1 μm or more observed in a toner cross-sectional image observed with a transmission electron microscope is 5% by number or less in one toner, and the pigment particles in the toner The average dispersion diameter is in the range of 0.1 to 0.7 μm.
(E) Group IA elements (excluding hydrogen), Group IIA elements, Group IIIB elements, and Group IVB elements (carbon) when the total intensity ratio of elements detected by fluorescent X-ray analysis is 100% The ratio of (except for) is in the range of 0.1 to 10%.
[0027]
<2>  The image forming method according to <1>, further comprising a transfer step of transferring the toner image on the surface of the electrostatic latent image carrier to a transfer body, wherein the transfer member is a transfer roll..
<3> ChargingrollA charging means for charging by applying an external voltage to the electrostatic latent image carrier, an electrostatic latent image forming means for forming an electrostatic latent image, and developing the electrostatic latent image into an electrostatic image development An image forming apparatus comprising: a toner image forming unit that visualizes using an agent, wherein the electrostatic charge image developer has the following conditions (a), (b), (c), (d), And an electrostatic image developing toner satisfying (e).
[0028]
(A) The volume average particle size D50v of the toner is in the range of 3 to 10 μm, and the volume average particle size distribution index GSDv and the number average particle size distribution index GSDp are both 1.25 or less.
(B) The particle size ratio of the number particle size distribution index GSDp-under on the small particle size side is 1.27 or less and the particle size of the particle size of 3/5 or less of the number average particle size D50n is 10% by number or less, and the volume average particle size The ratio of particles having a particle size of at least twice D50v is 10% by volume or less.
(C) The average circularity is in the range of 0.940 to 0.980, and the average circularity standard deviation is 0.1 or less.
(D) The number of aggregates of pigment particles having a maximum length of 1 μm or more observed in a toner cross-sectional image observed with a transmission electron microscope is 5% by number or less in one toner, and the pigment particles in the toner The average dispersion diameter is in the range of 0.1 to 0.7 μm.
(E) Group IA elements (excluding hydrogen), Group IIA elements, Group IIIB elements, and Group IVB elements (carbon) when the total intensity ratio of elements detected by fluorescent X-ray analysis is 100% The ratio of (except for) is in the range of 0.1 to 10%.
[0029]
<4>  The image forming apparatus according to <3>, further comprising transfer means for transferring the toner image on the surface of the electrostatic latent image carrier to a transfer body, wherein the transfer member is a transfer roll..
  Furthermore, in the present invention,The chargingThe roll preferably has a structure in which an ion conductive elastic layer and a surface layer in which an electronic conductive material is dispersed are sequentially laminated on a conductive support. The ion conductive elastic layer is preferably formed by blending at least one quaternary ammonium salt with urethane rubber or epichlorohydrin rubber, and the film thickness of the surface layer is in the range of 2 to 500 μm. It is preferable that
[0030]
As the transfer means, a transfer roll is preferably used. The transfer roll has a structure of two or more layers, an underlayer is formed of a conductive foam layer, and a thickness of 0. 0 is formed on the outside of the conductive foam layer. It is preferable that an elastic layer of 1 to 1.0 mm is coated. In the transfer roll, it is preferable that the base layer is composed of a conductive foam layer having an Asker C hardness of 40 ° or less, and the roll hardness is 45 ° or less.
[0031]
The image forming apparatus preferably includes an intermediate transfer member carried by primary transfer and means for secondary transfer of an unfixed toner image on the intermediate transfer member to a recording medium.
[0032]
The toner for developing an electrostatic charge image is obtained by mixing a resin fine particle dispersion, a colorant dispersion, a release agent dispersion, and an inorganic fine particle dispersion, and aggregating at a temperature lower than the glass transition temperature (Tg) of the resin fine particles. A toner obtained by forming a particle dispersion and then fusing it by heating to a temperature equal to or higher than the glass transition point of the resin fine particles is preferable, and in particular, a resin fine particle dispersion, a colorant dispersion, and a release agent dispersion. When the inorganic fine particle dispersion is mixed, it is preferably performed at a temperature 25 ° C. or lower than the Tg of the resin fine particles.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
  The present invention is described in detail below.
<Image forming method>
  The image forming method of the present invention isrollThe electrostatic latent image carrying member to be charged by applying a voltage from the outside and charging, an electrostatic latent image forming step for forming an electrostatic latent image, and developing the electrostatic latent image into an electrostatic image development A toner image forming step of developing the toner image using an agent, wherein the electrostatic image developer includes a toner for developing an electrostatic image satisfying specific conditions to be described later. This is a featured image forming method.
  Below, the component of this invention is demonstrated.
[0034]
The electrostatic image developing toner used in the present invention is an electrostatic image developing toner that satisfies the following conditions (a), (b), (c), (d), and (e).
Hereinafter, each condition will be described.
[0035]
-Condition (a)-
As the first condition, the toner volume average particle diameter D50v is in the range of 3 to 10 μm, and both the volume average particle size distribution index GSDv and the number average particle size distribution index GSDp are required to be 1.25 or less.
[0036]
The volume particle size distribution index GSDv and the number particle size distribution index GSDp are obtained as follows. First, for example, based on the particle size distribution measured by a measuring instrument such as Coulter Counter TAII (manufactured by Nikka Machine Co., Ltd.), the volume and number are each subtracted from the small particle size side, and the accumulation is 16%. The particle diameter is defined as a volume D16v and a number D16p, the particle diameter corresponding to a cumulative 50% is defined as a volume D50v and a number D50p, and the particle diameter corresponding to a cumulative 84% is defined as a volume D84v and a number D84p.
The volume particle size distribution index GSDv is (D84v / D16v)^1/2The number average particle size distribution index GSDp is calculated as (D84p / D16p)^1/2Is calculated as
[0037]
If the volume average particle diameter D50v is less than 3 μm, the chargeability is insufficient and scattering to the surroundings occurs, causing image fogging. On the other hand, if it exceeds 10 μm, the resolution of the image is lowered and it is difficult to achieve high image quality. On the other hand, when GSDv and GSDp exceed 1.25, the dispersion of the particle size distribution becomes large, and the graininess and resolution of the image may be lowered. Further, since the shape distribution also tends to widen, it is not preferable because it may affect the cleaning and transfer maintenance properties.
[0038]
-Condition (b)-
As the second condition, the particle size ratio of the small particle size side number particle size distribution index GSDp-under is 1.27 or less, and the particle ratio of the particle size of 3/5 or less of the number average particle size D50n is 10 number% or less, It is necessary that the ratio of particles having a particle size of at least twice the volume average particle size D50v is 10% by volume or less.
[0039]
The average particle size distribution index GSDp-under for the small particle size side is D16p obtained as a particle size value that is 16% cumulative from the small diameter side in the particle size distribution as described above, and 50% cumulative particle size. From D50p obtained as the particle size value, it is calculated as (D50p / D16p).
[0040]
When the GSDp-under exceeds 1.27, the ratio of the small particle size toner is increased, so that in addition to the initial performance, the reliability is extremely large. That is, as conventionally known, since the adhesion of small-diameter toner is large, electrostatic control is likely to be difficult, and when a two-component developer is used, the toner tends to remain on the carrier surface. In this case, when mechanical force is repeatedly applied, carrier contamination is caused, and as a result, deterioration of the carrier is promoted. Further, since the toner having a small particle size has a large adhesive force, the developing efficiency is also lowered, resulting in image quality defects.
[0041]
In particular, in the transfer process, among the toner developed on the surface of the photoreceptor, it is difficult to transfer a small diameter component, resulting in poor transfer efficiency, resulting in an increase in waste toner and poor image quality.
[0042]
As a result of these problems, toners that are not electrostatically controlled and reverse polarity toners increase, which contaminates the surroundings. In particular, the charging roll is not preferable because the toner that is not electrostatically controlled is accumulated through the photosensitive member or the like, and causes charging failure.
[0043]
When the ratio of the particles having a particle size of 3/5 or less of the number average particle diameter D50n exceeds 10% by number, the number of particles having a shape close to a sphere increases, and there is a problem in cleaning stability. In addition, these toner fine particles often do not sufficiently contain pigment particles or release agent particles, and cause charging failure and transfer failure when accumulated in the charging roll or transfer roll via a photoreceptor or the like. It is not preferable.
The ratio of particles having a particle size of 3/5 or less of the number average particle size D50n is more preferably 5 number% or less.
[0044]
When the ratio of particles having a particle size of twice or more of the volume average particle size D50v exceeds 10% by volume, the number of particles having a large particle size and an indeterminate shape increases, resulting in poor development, toner scattering from the developing device, and poor transfer. There are many problems such as toner destruction during cleaning, toner destruction due to rubbing with the charging roll and transfer roll, and filming. In particular, when the charging roll is contaminated, the roll resistance fluctuates and black streaks appear in the image.
In addition, it is more preferable that the ratio of particles having a particle size that is twice or more the volume average particle size D50v is 5% by volume or less.
[0045]
-Condition (c)-
As a third condition, it is necessary that the average circularity is in the range of 0.940 to 0.980, and the average circularity standard deviation is 0.1 or less.
The average toner circularity is measured by, for example, a flow type particle shape measuring instrument, an image analysis device, or the like, and the circumference of a circle having a maximum toner diameter (equivalent circumference) and the actual circumference of the toner ( (Perimeter length) and (circle equivalent perimeter / perimeter length).
[0046]
When the average circularity is less than 0.940, the ratio of irregularly shaped particles increases. Therefore, the toner scatters from the developing device, the toner transportability in the developing device is poor, the transfer is poor, the cleaning roll, the charging roll, the transfer roll, There are many problems such as film destruction due to toner destruction by rubbing. In particular, when the charging roll is contaminated, the roll resistance fluctuates and black streaks appear in the image.
[0047]
When the average circularity exceeds 0.980, the ratio of spherical particles increases, which causes cleaning failure. When a large amount of toner that has passed through the cleaner adheres to the charging roll and the transfer roll, the roll resistance fluctuates and black streaks are generated in the image.
[0048]
Further, when the average circularity standard deviation exceeds 0.1, the uniformity of the shape is deteriorated, so that the maintainability such as toner transportability, developability, transferability, cleaning property, and toner breakdown resistance is inferior. Therefore, a problem occurs in long-term use, which is not preferable.
[0049]
The toner used in the present invention is characterized by a narrow particle size distribution and a small amount of fine powder despite its small particle size, and its shape is intermediate between a spherical shape and an irregular shape. Further, by controlling the ratio of the specific element when the number of coarse aggregated particles of the pigment particles inside the toner is less than a certain value and the total detected element intensity ratio by fluorescent X-ray analysis is 100%, electrophotography Alternatively, it is possible to provide a good image forming method that satisfies the various characteristics of the development process, transfer process, cleaning process, and fixing process in the electrostatic recording method, and that does not break down the toner even after continuous running and has no toner passing through the cleaner. That is, since there is little toner adhesion to the charging roll or the transfer roll, it is possible to provide a high-quality image over a long period of time.
[0050]
-Condition (d)-
As a fourth condition, the number of aggregates of pigment particles having a maximum length of 1 μm or more observed in a toner cross-sectional image observed with a transmission electron microscope is 5% by number or less in one toner. is necessary.
[0051]
The aggregate of pigment particles in the toner is obtained by, for example, mixing the toner with an embedding agent such as an epoxy resin, cutting with a diamond cutter, and then observing the cut body with a transmission electron microscope (TEM). Can be confirmed. Then, the size of the pigment particles dispersed inside can be calculated by taking the observation image into the image analysis apparatus.
[0052]
When the number of pigment particles having a maximum length of 1 μm or more is more than 5% by number in one toner, the pigment particles are relatively likely to be present on the toner surface, the charging characteristics are lowered, and the background portion of the image is reduced. Scattering increases and image quality is impaired, which is not preferable. Even if the toner does not scatter, the low-charged toner remaining on the photoconductor is taken into the charging roll or transfer roll and fluctuates the roll resistance, which may cause problems such as black streaks or white spots in the image.
[0053]
In addition, if there are coarse particles of pigment particles, it tends to cause destruction at the interface between the pigment and the resin, which may affect the durability of the toner itself. By rubbing, the toner is liable to be destroyed, and the photosensitive member, roll, and cleaner may be contaminated.
[0054]
By limiting the coarse pigment particles to 5% by number or less, exposure of the pigment particles to the toner surface can be suppressed, and a toner excellent in durability can be provided.
The dispersion average particle diameter of the pigment particles is in the range of 0.1 to 0.7 μm, and preferably in the range of 0.2 to 0.5 μm, from the viewpoint of sufficient colorability and good dielectric properties.
[0055]
-Condition (e)-
As a fifth condition, a group IA element (excluding hydrogen), a group IIA element, a group IIIB element, and a group IVB when the total intensity ratio of elements detected by fluorescent X-ray analysis is 100%. The proportion of group elements (excluding carbon) needs to be in the range of 0.1 to 10%. The ratio is more preferably in the range of 0.1 to 5%.
[0056]
The above-mentioned Group IA elements (excluding hydrogen), Group IIA elements, Group IIIB elements, and Group IVB elements (excluding carbon) are the group numbers according to the IUPAC 1989 revised inorganic chemical nomenclature, It corresponds to a Group 1 element (excluding hydrogen), a Group 2 element, a Group 13 element, and a Group 14 element (excluding carbon), and representative elements include Li, Na, K, Rb Mg, Ca, Sr, Ba, Al, Si and the like. These elements are incorporated in the toner as an aggregating agent, an aggregation terminator, or a charge adjusting agent because they are water-soluble when used as hydroxides, chlorides, or the like, and an aqueous dispersion is obtained as a colloid. As a result, the binding of fine particles (resin, inorganic powder, etc.) constituting the toner can be controlled.
[0057]
When the ratio of Group IA elements (excluding hydrogen), Group IIA elements, Group IIIB elements, and Group IVB elements (excluding carbon) is less than 0.1%, toner durability is reduced and charging is performed. By rubbing with the roll, the cleaner, and the transfer roll, the toner is liable to be destroyed, which may cause contamination of the photoreceptor, the roll, and the cleaner.
[0058]
When the ratio of the above elements exceeds 10%, the toner durability is sufficient, but depending on the type of the remaining elements, the charging characteristics may be affected. Further, since the toner elastic modulus becomes too high, the toner may be insufficiently melted, and the strength of the fixed image may be affected. In particular, sufficient gloss may not be obtained for color images.
By limiting the proportion of Group IA elements (excluding hydrogen), Group IIA elements, Group IIIB elements, and Group IVB elements (excluding carbon) to a range of 0.1 to 10%, durability is improved. In addition, it is possible to provide a toner that can be used for both color and black, and has excellent durability of a fixed image.
[0059]
In addition, the fluorescent X-ray analysis for confirming this condition uses a fluorescent X-ray analyzer (manufactured by Shimadzu Corporation: XRF-1800) as an apparatus, an X-ray tube voltage of 40 kV, a filament current of 70 mA, and a sample molding amount of 6 g. It carried out on the conditions of +/- 0.01g.
[0060]
The toner in the present invention preferably contains a release agent from the viewpoint of obtaining oil-less fixing performance, and in this case, the release agent exposure rate on the toner surface determined by X-ray photoelectron spectroscopy (XPS) is used. Is preferably in the range of 11-40%.
[0061]
When the exposure rate of the release agent on the toner surface is less than 11%, there is a case where long-term maintainability is difficult although there is no influence on the fixing performance at the beginning. In addition, when the fixing device is deteriorated, the offset on the high temperature side and the fixed image strength on the low temperature side may be adversely affected. On the other hand, if it exceeds 40%, the fixing performance is not affected, but filming on the carrier, the developing roll, the photoreceptor, the charging roll, etc. may occur. In addition, a phenomenon such that the external additive added to impart fluidity is buried in the toner tends to occur.
The release agent exposure rate on the toner surface is more preferably in the range of 15 to 30%.
[0062]
In addition, the said mold release agent exposure rate can isolate | separate and quantify the peak resulting from resin, a pigment, and wax by measuring machines, such as a JEOL X-ray photoelectron spectrometer (XPS), for example.
[0063]
The release agent preferably has a melting point measured by a differential scanning calorimeter in the range of 70 to 130 ° C., and the content in the toner is in the range of 8 to 20% by mass. In addition, melting | fusing point of a mold release agent is measured based on ASTMD3418-8.
[0064]
When the melting point of the release agent is less than 70 ° C., offset tends to occur during fixing. On the other hand, if the temperature exceeds 130 ° C., the fixing temperature becomes high and the smoothness of the surface of the fixed image cannot be obtained, and the glossiness is impaired. When the amount of the release agent is less than 8% by mass, an offset phenomenon may occur at a high temperature. When the amount exceeds 20% by mass, the transparency on the image on the transparent film is insufficient, or the release agent. An offset may occur, which is not preferable.
[0065]
For example, DSC-7 manufactured by Perkin Elmer is used for measuring the melting point (mainly maximum peak) of the release agent. The temperature correction of the detection part of the apparatus uses the melting points of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. As the sample, an aluminum pan is used, an empty pan is set as a control, and the measurement is performed at a heating rate of 10 ° C./min.
[0066]
The toner in the present invention contains inorganic fine particles having a central particle in the range of 5 to 30 nm and inorganic fine particles having a central particle size in the range of 30 to 100 nm in a range of 0.5 to 10% by mass. From the viewpoint of durability.
[0067]
Examples of the inorganic fine particles include silica, hydrophobized silica, titanium oxide, alumina, calcium carbonate, magnesium carbonate, tricalcium phosphate, colloidal silica, cationic surface-treated colloidal silica, anion surface-treated colloidal silica, and the like. These inorganic fine particles are dispersed in advance in the presence of an ionic surfactant using an ultrasonic disperser or the like, and it is more preferable to use colloidal silica that does not require this dispersion treatment.
[0068]
When the addition amount of the inorganic fine particles is less than 0.5% by mass, the addition of the inorganic fine particles does not provide sufficient toughness at the time of melting the toner, and not only the releasability in oilless fixing can be improved, but also at the time of melting the toner. Coarse dispersion of the fine particles in the toner increases only the viscosity, and as a result, the spinnability is deteriorated, and the oilless releasability may be impaired. On the other hand, if it exceeds 10% by mass, sufficient toughness can be obtained, but the fluidity at the time of melting the toner is greatly reduced, and the image glossiness may be impaired.
[0069]
  The image forming method of the present invention isrollThe electrophotographic photosensitive member (electrostatic latent image carrier) and charging by applying a voltage from outside, an electrostatic latent image forming step for forming an electrostatic latent image, A transfer step for transferring a toner image on the surface of the electrophotographic photosensitive member to a transfer member (recording member or intermediate transfer member), and an electrophotographic photosensitive member. A cleaning step for removing residual toner on the body surface may be included.
[0070]
  In the present inventionObiThe electric roll is preferably formed by sequentially laminating an ion conductive elastic layer and a surface layer in which an electronic conductive material is dispersed on the surface of the conductive support.
[0071]
Examples of the ion conductive elastic layer include urethane rubber, epichlorohydrin rubber, polyether urethane rubber, polyester urethane rubber, chloroprene rubber, NBR, EPDM blend NBR rubber, SBR rubber, butyl rubber, and the like. It is preferable to incorporate various alkyl ammonium salts having a quaternary ammonium salt structure. As a compounding quantity or dispersion amount, the range of 0.01-20 mass% is preferable, and the range of 0.1-10 mass% is more preferable.
The volume resistance value of the ion conductive elastic layer is 10^Three-10^TenA range of Ωcm is preferable.
[0072]
Examples of the binder resin used for the surface layer include polyester, polyamide, polyurethane, melamine resin, acrylic resin such as polymethyl methacrylate (PMMA) or polymethylbutyl acrylate (PMBA), polyvinyl butyral, polyvinyl acetal, polyarylate, Polycarbonate, phenoxy resin, polyurea, polyvinyl acetate and the like can be mentioned.
[0073]
As the electroconductive substance blended in the resin, various conductive carbon blacks or metal oxides can be used, and it is preferable to adjust the resistance by dispersing them. As a compounding quantity or dispersion amount, the range of 0.01-20 mass% is preferable, and the range of 0.1-10 mass% is more preferable.
Moreover, it is preferable to form the film thickness of the said surface layer in the range of 2-500 micrometers, and it is more preferable to form in the range of 20-200 micrometers.
[0074]
The volume resistance value of the charging roll configured as described above is 10^Three-10⁹A range of Ω is preferred. In addition, this roll volume resistance value was measured according to JIS K6991 using the circular electrode (For example, Mitsubishi Yuka Co., Ltd. product: High Lester IP HP probe) in the applied voltage of 100 V / cm.
[0075]
The transfer roll used for the transfer member in the present invention preferably has a structure in which two or more layers are provided on the surface of the conductive support. The underlayer (foamed layer) is composed of a conductive foamed layer, and an elastic layer having a thickness of 0.1 to 1.0 mm is preferably formed outside the conductive foamed layer.
[0076]
When the thickness of the elastic layer is 0.1 mm or more, the nip portion is not locally deformed in the transfer portion, so that there is a problem of peeling along the intermediate transfer member and the photosensitive member side facing the sheet. Absent. That is, the deformation of the nip portion is caused by the elastic layer being pressed by the entire surface of the nip portion due to the nip pressure. For this reason, the curvature of the nip portion is increased, and the same effect is obtained as when the transfer roll having a large outer diameter represented by the phantom line is pressed, and as a result, the sheet is peeled along the transfer roll having a large curvature. , Paper peelability is improved.
[0077]
Further, by setting the thickness of the elastic layer to 1.0 mm or less, the nip pressure applied to the elastic layer is relieved by the underlying foam layer, so that the contact pressure of the transfer member can be reduced. Therefore, since the load of the pressing force by the bias roller does not concentrate on the transfer member, there is no problem of generating image quality defects such as a hollow character in which the line image is lost.
[0078]
In the transfer roll used for the transfer member in the present invention, it is preferable that the base layer is composed of a conductive foam layer having an Asker C hardness of 40 ° or more, and the roll hardness is 45 ° or less in Asker C hardness. The synergistic action with the elastic layer avoids local deformation of the nip portion, and improves the paper peelability due to desired deformation of the nip portion.
[0079]
The resistance value of the transfer roll configured as described above is 10⁷-10¹²A range of Ω is preferred. The roll resistance value was measured by the same method as that for the charging roll.
[0080]
Further, in the toner for developing an electrostatic charge image in the present invention, a resin fine particle dispersion, a colorant dispersion, a release agent dispersion, and an inorganic fine particle dispersion are mixed, and the glass transition temperature (Tg) or less of the resin fine particles is reduced. A toner obtained by forming an aggregated particle dispersion and then heating and fusing the resin fine particles to a temperature equal to or higher than the glass transition point of the resin fine particles is preferable.
[0081]
When mixing the resin fine particle dispersion, the colorant dispersion, the release agent dispersion, and the inorganic fine particle dispersion, it is preferably performed at a temperature 25 ° C. or more lower than the Tg of the resin fine particles. If the temperature is higher than this range, the resin particles dispersion, colorant dispersion, release agent dispersion, and inorganic particles are gradually agglomerated from the less stable due to the difference in electrostatic stability. Occurs, and the toner internal structure is uneven. In particular, when the colorant particles aggregate to form a non-uniform structure, it becomes difficult to control toner particle size distribution, shape distribution control, durability, and charging performance, or the condition (d) required for the toner It becomes impossible to satisfy.
[0082]
The toner for developing an electrostatic charge image in the present invention specifically includes a resin fine particle dispersion in which at least resin particles are dispersed, a colorant dispersion, a release agent dispersion, and an inorganic fine particle dispersion. A first step (aggregation step) for forming aggregated particles and preparing an aggregated particle dispersion, and adding and mixing a fine particle dispersion in which fine particles are dispersed in the aggregated particle dispersion to attach the fine particles to the aggregated particles It is preferable to manufacture by a method including a second step (attachment step) for forming the adhered particles and a third step (fusion step) for fusing the adhered particles by heating.
[0083]
The second step is preferably performed a plurality of times. In the second step, a release agent fine particle dispersion obtained by dispersing release agent fine particles is added to and mixed with the aggregated particle dispersion, and the release agent fine particles are adhered to the aggregated particles to form attached particles. Thereafter, it is preferable to add and mix a resin-containing fine particle dispersion in which resin-containing fine particles are dispersed to further adhere the resin-containing fine particles to the adhered particles to form the adhered particles.
[0084]
In the second step, a colorant fine particle dispersion in which colorant fine particles are dispersed is added to and mixed with the resin fine particle agglomerated particle dispersion, and the colorant fine particles are adhered to the aggregated particles to adhere particles. It is preferable to add the resin-containing fine particle dispersion obtained by dispersing the resin-containing fine particles, and further adhere the resin-containing fine particles to the attached particles to form the attached particles.
[0085]
Further, in the second step, the resin-containing fine particles obtained by dispersing the resin-containing fine particles in the aggregated particle dispersion are added and mixed, and the resin-containing fine particles are adhered to the aggregated particles to form the adhered particles. The step is preferably a step of adding and mixing an inorganic fine particle dispersion in which fine particles are dispersed, and further attaching inorganic fine particles to the adhered particles to form the adhered particles.
[0086]
In the second step, the fine particle dispersion is added to and mixed with the aggregated particle dispersion prepared in the first step, and the fine particles are adhered to the aggregated particles to form adhered particles. The fine particles correspond to particles newly added to the aggregated particles when viewed from the aggregated particles, and may be referred to as “additional particles”.
[0087]
The method for adding and mixing the fine particle dispersion is not particularly limited. For example, the fine particle dispersion may be gradually and continuously performed, or may be divided into a plurality of steps and performed stepwise. Thus, by adding and mixing the fine particles (additional particles), generation of fine particles can be suppressed, and the particle size distribution of the resulting electrostatic image developing toner can be sharpened. If the addition and mixing are performed in stages divided into a plurality of times, a layer of the fine particles is layered stepwise on the surface of the aggregated particles, and the structural change or the like from the inside to the outside of the electrostatic image toner particles The composition can have a gradient, the surface hardness of the particles can be improved, and the particle size distribution can be maintained during the fusion in the third step, the fluctuation can be suppressed, and the stability during the fusion can be suppressed. It is advantageous in that the addition of a surfactant or a stabilizer such as a base or an acid is not required, and the amount of these additives can be suppressed to the minimum, and costs can be reduced and quality can be improved. It is.
[0088]
Examples of the polymer used as the thermoplastic binder resin used for the resin particles in the present invention include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, and acrylic acid n. -Esters having a vinyl group such as propyl, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; acrylonitrile, methacrylonitrile Vinyl nitriles such as vinyl methyl ether and vinyl isobutyl ether, vinyl ethers such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone; polyolefins such as ethylene, propylene and butadiene Polymers such as monomers, copolymers obtained by combining two or more of these, or mixtures thereof, as well as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyethers Examples thereof include a resin, a non-vinyl condensation resin, a mixture of these with the vinyl resin, and a graft polymer obtained when a vinyl monomer is polymerized in the presence of these. These resins may be used alone or in combination of two or more.
[0089]
Among these resins, vinyl resins are particularly preferable. In the case of a vinyl resin, it is advantageous in that a resin particle dispersion can be easily prepared by emulsion polymerization or seed polymerization using an ionic surfactant or the like.
[0090]
The method for preparing the dispersion of resin particles is not particularly limited, and a method appropriately selected according to the purpose can be adopted. For example, it can be prepared as follows.
[0091]
When the resin in the resin particles is a homopolymer or copolymer (vinyl resin) of a vinyl monomer such as the ester having a vinyl group, the vinyl nitrile, the vinyl ether, or the vinyl ketone. The vinyl monomer is subjected to emulsion polymerization, seed polymerization or the like in an ionic surfactant, thereby converting the vinyl monomer homopolymer or copolymer resin particles into an ionic surfactant. It is possible to prepare a dispersion obtained by dispersing in the above.
[0092]
When the resin in the resin particles is a resin other than the homopolymer or copolymer of the vinyl monomer, if the resin is dissolved in an oily solvent having a relatively low solubility in water, By dissolving the resin in the oily solvent, adding the dissolved material together with the ionic surfactant or polymer electrolyte in water, dispersing the particles using a disperser such as a homogenizer, and then heating or reducing the pressure. It can be prepared by evaporating the oily solvent.
[0093]
When the resin particles dispersed in the resin particle dispersion are composite particles containing components other than the resin particles, a dispersion in which these composite particles are dispersed can be prepared as follows. . For example, each component of the composite particles is dissolved and dispersed in a solvent, and then dispersed in water together with an appropriate dispersant as described above, and the solvent is removed by heating or decompression, emulsion polymerization, It can be prepared by a method of immobilizing by carrying out mechanical shearing or electroadsorption on the latex surface produced by seed polymerization.
[0094]
The average particle size of the resin particles is desirably 1 μm or less, and more desirably in the range of 0.01 to 1 μm. When the average particle diameter of the resin particles exceeds 1 μm, the particle size distribution of the finally obtained electrostatic image developing toner is broadened or free particles are generated, leading to performance and reliability deterioration. On the other hand, when the average particle diameter of the resin particles is within the above range, the above disadvantages are eliminated, uneven distribution among the toners is reduced, dispersion in the toners is improved, and variations in performance and reliability are reduced. It is advantageous. The average particle diameter of the resin particles can be measured using, for example, a microtrack.
[0095]
Examples of the colorant include carbon black, chrome yellow, hansa yellow, benzidine yellow, selenium yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliant carmine 3B, and brilliant carmine 6B. , DuPont oil red, pyrazolone red, risor red, rhodamine B rake, lake red C, rose bengal, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxalate Pigments;
[0096]
Acridine, xanthene, azo, benzoquinone, azine, anthraquinone, dioxazine, thiazine, azomethine, indico, thioindico, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane And various dyes such as thiazine series, thiazole series and xanthene series.
[0097]
These colorants may be used alone or in combination of at least two (two or more). In the latter case, the color of the toner can be arbitrarily adjusted by changing the type and mixing ratio of the colorant (pigment). The colorant dispersion can be prepared, for example, by dispersing the colorant in an aqueous medium such as the surfactant.
[0098]
The average particle diameter of the colorant particles in the present invention is desirably 0.8 μm or less, and more desirably in the range of 0.05 to 0.5 μm. When the average particle diameter of the colorant particles exceeds 0.8 μm, the particle size distribution of the finally obtained toner for developing an electrostatic charge image is broadened, or free particles are generated, leading to a decrease in performance and reliability. When the average particle diameter of the colorant particles is smaller than 0.05 μm, not only the colorability in the toner is lowered, but also the shape controllability that is one of the characteristics of the emulsion aggregation method is impaired, and the shape close to a true sphere. No toner can be obtained.
[0099]
Further, the number% of particles of 0.8 μm or more is preferably less than 10%, and substantially preferably 0%. The presence of such coarse particles impairs the stability of the agglomeration process and widens the particle size distribution as well as liberation of coarse colored particles. The number% of particles of 0.05 μm or less is preferably 5% or less. The presence of such fine particles impairs the shape controllability in the fusion process, making it impossible to obtain a smooth one. On the other hand, when the average particle diameter, coarse particles, and fine particles of the colorant particles are within the above ranges, there is no such defect, and uneven distribution between the toners is reduced, and dispersion in the toners is improved. Further, it is advantageous that the variation in reliability is reduced.
[0100]
The average particle diameter of the colorant particles can be measured using, for example, a microtrack. The amount of the colorant added is preferably set in the range of 1 to 20% by mass with respect to the toner particles.
[0101]
In the present invention, the colorant can be surface-modified with rosin, polymer, or the like.
The colorant subjected to the surface modification treatment is sufficiently stabilized in the colorant dispersion, and after the colorant is dispersed to a desired average particle size in the colorant dispersion, the resin particles are dispersed. When mixed with the liquid, the colorants are not aggregated even in the aggregation process and the like, which is advantageous in that a good dispersion state can be maintained. On the other hand, the colorant that has been subjected to an excessive surface modification treatment may be released without agglomerating with the resin particles in the aggregation process. For this reason, the said surface modification process is performed on the optimal conditions selected suitably.
[0102]
Examples of the polymer include acrylonitrile polymer and methyl methacrylate polymer.
[0103]
As the conditions for the surface modification, generally, a polymerization method in which a monomer is polymerized in the presence of a colorant (pigment), a colorant (pigment) is dispersed in a polymer solution, and the solubility of the polymer is lowered to reduce the colorant ( (Pigment) A phase separation method for depositing on the surface can be used.
[0104]
For example, when the other component is a release agent, the dispersion obtained by dispersing the release agent and other components (particles) such as an internal additive is an ionic surfactant, a polymer acid, or a polymer. Disperse in water with a polymer electrolyte such as a base. While heating this above the melting point of the release agent, it can be prepared by making the release agent fine particles by applying strong shearing using a homogenizer or a pressure discharge type disperser. When the other component (particle) is an inorganic particle or the like, it can be prepared by dispersing the inorganic particle or the like in an aqueous medium such as the surfactant.
[0105]
Examples of the release agent include low molecular weight polyolefins such as polyethylene, polypropylene and polybutene, silicones having a softening point upon heating, fatty acids such as oleic acid amide, erucic acid amide, ricinoleic acid amide, stearic acid amide and the like. Amide, carnauba wax, rice wax, candelilla wax, plant wax such as tree wax, jojoba oil, animal wax such as beeswax, montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, fisher Minerals such as Tropsch wax, petroleum-based waxes, and modified products thereof can be used. These release agents may be used alone or in combination of two or more.
[0106]
The average particle size of the other components (particles) is desirably 1 μm or less, and more desirably in the range of 0.01 to 1 μm. When the average particle size exceeds 1 μm, the particle size distribution of the finally obtained electrostatic image developing toner is broadened, or free particles are generated, leading to deterioration in performance and reliability. On the other hand, when the average particle diameter of the resin particles is within the above range, the above disadvantages are eliminated, uneven distribution among the toners is reduced, dispersion in the toners is improved, and variations in performance and reliability are reduced. It is advantageous. The average particle diameter can be measured using, for example, a microtrack.
[0107]
Examples of the dispersion medium in the dispersion obtained by dispersing the resin particle dispersion, the colorant dispersion, and the other components (particles) include an aqueous medium.
Examples of the aqueous medium include water such as distilled water and ion exchange water, and alcohols. These may be used individually by 1 type and may use 2 or more types together.
[0108]
The means for preparing the various dispersions is not particularly limited, and examples thereof include known dispersion devices such as a rotary shear type homogenizer, a ball mill having a media, a sand mill, and a dyno mill.
[0109]
In the present invention, various commonly used charge control agents such as quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments can be used as charge control agents. However, a material that is difficult to dissolve in water is preferably used from the viewpoints of controlling ionic strength that affects aggregation and temporary stability and reducing wastewater contamination.
[0110]
When the charge control agent or the flocculant is added as described above, the condition (e) in the present invention is a group IA element (excluding hydrogen) or group IIA in fluorescent X-ray analysis. It is necessary to control the amount of addition so that the ratio of the elements, Group IIIB elements, and Group IVB elements (excluding carbon) is in the range of 0.1 to 10%.
[0111]
In the present invention, it is preferable to add and mix a surfactant in the aqueous medium. Examples of the surfactant include anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene Preferable examples include nonionic surfactants such as glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, an ionic surfactant is preferable, and an anionic surfactant and a cationic surfactant are more preferable.
[0112]
The nonionic surfactant is preferably used in combination with the anionic surfactant or the cationic surfactant. The said surfactant may be used individually by 1 type, and may use 2 or more types together.
[0113]
Specific examples of the anionic surfactant include fatty acid soaps such as potassium laurate, sodium oleate and sodium castor oil; sulfates such as octyl sulfate, lauryl sulfate, lauryl ether sulfate and nonylphenyl ether sulfate; lauryl sulfonate , Dodecyl sulfonate, dodecyl benzene sulfonate, triisopropyl naphthalene sulfonate, dibutyl naphthalene sulfonate, etc. Sulfonates such as lauryl phosphate, isopropyl phosphate Phosphoric acid esters such as nonyl phenyl ether phosphate; dialkyl sodium sulfosuccinates, such as sodium dioctyl sulfosuccinate, sodium lauryl sulfosuccinate 2, polyoxyethylene sulfo sulfosuccinate salts such as succinic acid lauryl disodium; and the like.
[0114]
Specific examples of the cationic surfactant include laurylamine hydrochloride, stearylamine hydrochloride, oleylamine acetate, stearylamine acetate, stearylaminopropylamine acetate, and other amine salts; lauryltrimethylammonium chloride, dilauryldimethylammonium Chloride, distearyl ammonium chloride, distearyl dimethyl ammonium chloride, lauryl dihydroxyethyl methyl ammonium chloride, oleyl bis polyoxyethylene methyl ammonium chloride, lauroyl aminopropyl dimethyl ethyl ammonium etosulphate, lauroyl aminopropyl dimethyl hydroxyethyl ammonium perchlorate, alkylbenzene dimethyl Ammonium chloride, alkylto Quaternary ammonium salts such as ammonium chloride; and the like.
[0115]
Specific examples of the nonionic surfactant include polyoxyethylene octyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether and other alkyl ethers; Alkylphenyl ethers such as oxyethylene nonylphenyl ether; alkyl esters such as polyoxyethylene laurate, polyoxyethylene stearate, polyoxyethylene oleate; polyoxyethylene lauryl amino ether, polyoxyethylene stearyl amino ether, polyoxy Alkylamines such as ethylene oleyl amino ether, polyoxyethylene soybean amino ether, polyoxyethylene beef tallow amino ether; Alkyl amides such as xylethylene lauric acid amide, polyoxyethylene stearic acid amide, polyoxyethylene oleic acid amide; vegetable oil ethers such as polyoxyethylene castor oil ether, polyoxyethylene rapeseed oil ether; lauric acid diethanolamide, stearin Alkanolamides such as acid diethanolamide and oleic acid diethanolamide; sorbitan ester ethers such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate And the like.
[0116]
In the present invention, a dispersion in which particles containing at least resin particles are dispersed is prepared by adding and mixing the resin particle dispersion or a dispersion composed of the colorant dispersion or other components to room temperature to By heating in the range of the glass transition temperature of the resin, the resin particles and the colorant are aggregated to form aggregate particles. The volume average particle diameter of the aggregate fine particles is preferably in the range of 3 to 10 μm.
[0117]
When the resin particle dispersion and the colorant dispersion are mixed, the content of the resin particles may be 40% by mass or less, and is preferably in the range of 2 to 20% by mass. Moreover, as content of the said coloring agent, it should just be 50 mass% or less, and it is preferable that it is about the range of 2-40 mass%. Furthermore, the content of the other components (particles) may be a level that does not hinder the object of the present invention, and is generally very small, specifically 0.01 to 5% by mass. The range is about 0.5 to 2% by mass.
[0118]
In the electrostatic image developing toner used in the present invention, when the adhesion step is performed, the aggregated particles are used as mother particles, and a coating layer of the fine particles (additional particles) is formed on the surface of the mother particles. It has the structure which becomes. The layer of the fine particles (additional particles) may be one layer or two or more layers. Generally, the number of layers is the adhesion in the method for producing an electrostatic charge image developing toner of the present invention. It is the same as the number of times the process was performed.
[0119]
Next, the mixed liquid containing aggregate particles is heat-treated at a temperature equal to or higher than the softening point of the resin, generally in the range of 70 to 120 ° C., and the aggregate particles are fused to form a toner particle-containing liquid (toner particle dispersion). Obtainable.
[0120]
The obtained toner particle dispersion is separated into toner particles by centrifugation or suction filtration, and washed 1 to 3 times with ion exchange water. Thereafter, the toner particles are separated by filtration, washed 1 to 3 times with ion-exchanged water, and dried to obtain the electrostatic image developing toner used in the present invention.
[0121]
Further, the electrostatic charge image developing toner in the present invention preferably has an absolute value of the charge amount in the range of 20 to 50 μC / g, more preferably in the range of 25 to 40 μC / g. If the charge amount is less than 20 μC / g, background stains tend to occur, and if it exceeds 50 μC / g, the image density tends to decrease. The ratio of the charge amount in summer and the charge amount in winter (summer charge amount / winter charge amount) of this electrostatic charge image developing toner is more preferably in the range of 0.7 to 1.3. When the ratio is out of the preferable range, the toner environment dependency is strong, charging stability is lacking, and it may be practically undesirable.
[0122]
In the electrostatic charge image developing toner used in the present invention, the molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured using gel permeation chromatography is: The range of 2-30 is preferable and the range of 3-20 is more preferable. When the molecular weight distribution represented by the ratio (Mw / Mn) exceeds 30, light transmittance and colorability are not sufficient, and in particular, when an electrostatic charge image developing toner is developed or fixed on a film, An image projected by transmission becomes a sharp and dark image or a projection image which does not transmit and does not develop color, and if it is less than 2, the viscosity of the toner at the time of high-temperature fixing is remarkably lowered, and offset tends to occur. On the other hand, when the molecular weight distribution represented by the ratio (Mw / Mn) is within the above numerical range, the light transmittance and colorability are sufficient, and the viscosity of the toner for developing an electrostatic charge image during high-temperature fixing is reduced. Can be prevented, and the occurrence of offset can be effectively suppressed.
[0123]
The toner for developing an electrostatic image in the present invention is excellent in various properties such as charging property, developing property, transfer property, fixing property, cleaning property, and cleaning property over a long period of time. In addition, since the various performances are stably exhibited and maintained without being affected by environmental conditions, the reliability is high. In addition, since the toner for developing an electrostatic charge image in the present invention is manufactured by the above-described toner manufacturing method, the average particle size is small and the particle size distribution is sharp unlike the case of manufacturing by the kneading and pulverizing method. It is.
[0124]
Furthermore, the pigment particles in the toner do not have coarse aggregates, and ions and fine particles are firmly bonded to the extent that they do not interfere with the melting characteristics at the time of fixing. It will not be polluted or damaged.
[0125]
The electrostatic image developing toner finally heated as described above contains inorganic particles such as silica, alumina, titania and calcium carbonate, and resin fine particles such as vinyl resin, polyester and silicone. It can be applied to the surface by applying a shearing force in a dry state and used as a fluidity aid or a cleaning aid. Examples of the inorganic particles include all particles usually used as external additives on the toner surface, such as silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, and cerium oxide.
[0126]
Examples of the organic particles include all particles usually used as external additives on the toner surface, such as vinyl resins, polyester resins, and silicone resins. These inorganic particles and organic particles can be used as fluidity aids, cleaning aids, and the like. Examples of the lubricant include fatty acid amides such as ethylene bisstearylamide and oleic acid amide, and fatty acid metal salts such as zinc stearate and calcium stearate.
[0127]
The electrostatic image developer in the present invention is not particularly limited except that it contains the toner for developing an electrostatic image, and can have an appropriate component composition depending on the purpose. For example, as the electrostatic charge image developer in the present invention, the electrostatic charge image developing toner may be used alone to prepare a one-component electrostatic charge image developer, or used in combination with a carrier. It may be prepared as a component electrostatic image developer.
[0128]
The carrier is not particularly limited, and examples thereof include known carriers. For example, known carriers such as resin-coated carriers described in JP-A Nos. 62-39879 and 56-11461 are known. Carrier can be used. The mixing ratio of the electrostatic image developing toner of the present invention and the carrier in the electrostatic image developer is not particularly limited and may be appropriately selected depending on the intended purpose.
[0129]
The image forming method of the present invention includes a charging step, an electrostatic latent image forming step, and a toner image forming step, and may include a transfer step and a cleaning step. Each of the above steps is a general step per se, and is described in, for example, JP-A-56-40868 and JP-A-49-91231.
[0130]
The image forming method of the present invention can be carried out by using a known image forming apparatus such as a copying machine or a facsimile machine. In the image forming method of the present invention, the charging roll, the transfer roll, By combining the toner, the following effects with high image quality and excellent maintainability can be expected.
[0131]
That is, the toner according to the present invention is a toner having a small particle size distribution such that the volume average particle diameter D50v is a small particle diameter in the range of 3 to 10 μm, but the particle size distribution is narrow and the electrostatic characteristics cannot be controlled. Therefore, even after image formation over a long period of time, contamination of the charging roll is small and the charging property of the charging roll can be maintained over a long period. Furthermore, in addition to a portion where the charging roll has good environmental resistance and stability and in combination with a toner, a high-quality image can be maintained over a long period of time.
[0132]
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the surface of the electrostatic latent image carrier. The toner image forming step is a step of developing the electrostatic latent image with a developer layer on a developer carrier to form a toner image. The developer layer is not particularly limited as long as it contains the electrostatic image developing toner of the present invention. The transfer step is a step of transferring the toner image to the surface of the transfer body. The cleaning step is a step of removing the electrostatic charge image developer remaining on the electrostatic latent image carrier.
[0133]
<Image forming apparatus>
  Next, the image forming apparatus of the present invention will be described.
  The image forming apparatus of the present invention is chargedrollA charging means for charging by applying an external voltage to the electrostatic latent image carrier, an electrostatic latent image forming means for forming an electrostatic latent image, and developing the electrostatic latent image into an electrostatic image development An image forming apparatus comprising: a toner image forming unit that develops an image using an agent, wherein the electrostatic image developer includes a toner for developing an electrostatic image that satisfies a specific condition described later. The image forming apparatus is characterized.
[0134]
FIG. 1 is a schematic cross-sectional view showing an electrophotographic apparatus which is an example of the image forming apparatus of the present invention. The electrophotographic apparatus shown in FIG. 1 includes an electrophotographic photosensitive member (electrostatic latent image carrier) 10, a charger (charging means) 11 that charges the surface of the electrophotographic photosensitive member 10, and a voltage applied to the charger 11. Power supply 12, an image input device (electrostatic latent image forming means) 13 that forms a latent image on the surface of the electrophotographic photosensitive member 10, and an electrostatic charge image developer. A developing unit (developing unit) 14 that develops the electrostatic latent image to obtain a toner image, a transfer unit (transfer unit) 15 that transfers the formed toner image to the surface of the recording medium 20, and a specific cleaning blade. A cleaning device (cleaning means) 16 that removes residual toner and the like on the surface of the electrophotographic photosensitive member 10 with a certain blade 19, a static eliminator 17 that removes a residual potential on the surface of the electrophotographic photosensitive member 10, and transfer to the surface of the recording material 20. Toner The image has a fixing device 18 for fixing by heat and / or pressure, etc., the.
[0135]
  The electrophotographic photosensitive member 10 in FIG.IsA contact charging type charger 11 is arranged, and the charger 11 is operated by a voltage supplied from a power source 12. In this example, the transfer device 15 uses a contact transfer method such as a transfer roll, but in the present invention, the contact transfer method or the non-contact transfer method is not limited.
  The cleaning device 16 is configured such that a blade 19 which is a cleaning blade of the present invention is provided in an opening of the box body 21, and residual toner and the like removed from the surface of the electrophotographic photosensitive member 10 are accommodated in the box body 21. It has a structure.
[0136]
In addition, the configurations of the image input device (electrostatic latent image forming unit) 13, the developing unit (developing unit) 14, the transfer unit (transfer unit) 15, the static eliminator 17, and the fixing unit 18 are particularly limited in the present invention. Instead, any configuration conventionally known in the electrophotographic field can be applied as it is. In the case of the configuration using the contact charging type charger 11 as in this example, the static eliminator 17 is not necessarily provided.
[0137]
In the image forming apparatus, by using the developer containing the toner of the present invention as the electrostatic charge image developer, various characteristics such as chargeability, developability, transferability, fixability, and cleanability are maintained over a long period of time. can do. In addition, since the various performances are stably exhibited and maintained without being affected by environmental conditions, the reliability is high. In addition, the pigment particles in the toner do not have coarse aggregates, and ions, fine particles, etc. are firmly bonded to the extent that they do not interfere with melting during fixing. Therefore, it is possible to stably form a high-quality image without causing damage.
[0138]
【Example】
Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.
First, toners, charging rolls, transfer rolls and the like used in Examples and Comparative Examples will be described.
[0139]
[Production of toner]
Various dispersions were prepared and toners were prepared as described below. The physical properties of resin fine particles, toner and the like were measured by the following method.
-Measurement of molecular weight and molecular weight distribution-
The molecular weight and molecular weight distribution were measured by gel permeation chromatography (GPC) using HLC-8120GPC and SC-8020 (manufactured by Tosoh Corporation) as measuring devices.
[0140]
-Particle size of dispersed fine particles-
Number average particle diameter D50n of resin fine particles with a laser diffraction particle size distribution analyzer (LA-700, manufactured by HORIBA, Ltd.) Was measured.
[0141]
-Glass transition temperature-
It measured with the temperature increase rate of 10 degree-C / min using the differential scanning calorimeter (Shimadzu Corporation company make: DSC-50).
[0142]
<Preparation of various dispersions>
(Resin fine particle dispersion)
・ Styrene (made by Wako Pure Chemical Industries) 340 parts by mass
・ N-Butyl acrylate (Wako Pure Chemical Industries) 60 parts by mass
・ 9 parts by mass of β-carboxyethyl acrylate (manufactured by Rhodia Nikka)
-1.2 'part by mass of 1'10-decanediol diacrylate (manufactured by Shin-Nakamura Chemical)
・ Dodecanethiol (manufactured by Kao) 2.7 parts by mass
[0143]
The above materials were mixed and dissolved. This was added to a solution obtained by dissolving 4 parts by weight of an anionic surfactant (manufactured by Dow Chemical: Dow Fax) in 550 parts by weight of ion-exchanged water, dispersed and emulsified by mechanical stirring in a flask, and slowly stirred for 10 minutes. While stirring and mixing, 50 parts by mass of ion-exchanged water in which 6 parts by mass of ammonium persulfate was dissolved was added. Then, after sufficiently replacing the nitrogen in the system sufficiently, the flask was heated with an oil bath while stirring until the system reached 70 ° C., and emulsion polymerization was continued for 5 hours.
As a result, an anionic resin dispersion having a center diameter of 210 nm, a solid content of 43% by mass, a glass transition point of 51.0 ° C., and an Mw of 35000 was obtained.
[0144]
(Colorant particle dispersion)
-Colorant particle dispersion (1)-
・ Phthalocyanine pigment (manufactured by Dainichi Seika Co., Ltd .: PVFASTBLUE) 50 parts by mass
Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 10 parts by mass
・ 240 parts by mass of ion exchange water
[0145]
Each of the above materials is mixed and dispersed for 10 minutes using a homogenizer (IKA: Ultra Turrax 750), and then applied to a circulating ultrasonic disperser (manufactured by Nippon Seiki Seisakusho: RUS-600TCVP). (1) was prepared. The average particle size of the colorant in the obtained colorant dispersion (1) was 150 nm, particles having a particle size of 0.03 μm or less were 3.0% by number, and particles having a particle size of 0.5 μm or more were 0.2% by number. .
[0146]
-Colorant particle dispersion (2)-
・ 50 parts by mass of carbon black (CABOT: R330)
Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 10 parts by mass
・ 240 parts by mass of ion exchange water
[0147]
The above materials were mixed, and a colorant particle dispersion (2) was prepared under the same conditions as the colorant particle dispersion (1). The average particle diameter of the colorant in the obtained colorant dispersion (2) was 155 nm, particles having a particle size of 0.03 μm or less were 4.0% by number, and particles having a particle size of 0.5 μm or more were 0.4% by number. .
[0148]
-Colorant particle dispersion (3)-
・ C. I. Pigment Red 122 (manufactured by Dainichi Chemical Co., Ltd .: ECR-185) 50 parts by mass
Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 10 parts by mass
・ 240 parts by mass of ion exchange water
[0149]
The above materials were mixed to prepare a colorant particle dispersion (3) under the same conditions as those for the colorant particle dispersion (1). The average particle diameter of the colorant in the obtained colorant dispersion (3) was 165 nm, particles having a particle size of 0.03 μm or less were 5.0% by number, and particles having a particle size of 0.5 μm or more were 0.4% by number. .
[0150]
-Colorant particle dispersion (4)-
・ C. I. Pigment Red 185 (manufactured by Clariant) 50 parts by mass
Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 10 parts by mass
・ 240 parts by mass of ion exchange water
[0151]
The above materials were mixed, and a colorant particle dispersion (4) was prepared under the same conditions as the colorant particle dispersion (1). The average particle size of the colorant in the obtained colorant dispersion (4) was 170 nm, particles having a particle size of 0.03 μm or less were 6.0% by number, and particles having a particle size of 0.5 μm or more were 0.3% by number. .
[0152]
-Colorant particle dispersion (5)-
・ C. I. Pigment Yellow 74 (manufactured by Clariant) 50 parts by mass
Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 10 parts by mass
・ 240 parts by mass of ion exchange water
[0153]
The respective materials described above were mixed, and a colorant particle dispersion (5) was prepared under the same conditions as in the colorant particle dispersion (1). The average particle size of the colorant in the obtained colorant dispersion (5) was 175 nm, particles having a particle size of 0.03 μm or less were 5.0% by number, and particles having a particle size of 0.5 μm or more were 0.3% by number. .
[0154]
(Preparation of release agent dispersion)
・ 50 parts by mass of polyethylene wax (Toyo Petrolite Co., Ltd .: PW725, melting point: 104 ° C.)
・ Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 5 parts by mass
・ 240 parts by mass of ion exchange water
[0155]
Each of the above materials was mixed and dispersed for 10 minutes using a homogenizer (IKA Corp .: Ultra Turrax 750), and then dispersed with a pressure discharge homogenizer to obtain a release agent dispersion having a center particle size of 200 nm. .
[0156]
<Preparation of toner particles>
(Toner particle 1)
・ Ion-exchanged water 500 parts by mass
・ 200 parts by mass of resin fine particle dispersion
Colorant particle dispersion (1) 70 parts by weight
・ 70 parts by weight of release agent dispersion
・ Inorganic fine particle dispersion (Nissan Chemical Co., Ltd .: Snowtex OL) 10 parts by mass
・ Inorganic fine particle dispersion (Nissan Chemical Co., Ltd .: Snowtex OS) 10 parts by mass
・ Metal salt flocculant (Asada Chemical Co., Ltd .: polyaluminum chloride) 2.0 parts by mass
[0157]
-Aggregation process-
The above materials were mixed and dispersed in a round stainless steel flask using a homogenizer (manufactured by IKA: Ultra Tarrax T50). At the time of mixing, the liquid temperature was controlled at 25 ° C., and the resin particle dispersion, the colorant dispersion, and the release agent dispersion were divided into three steps. Thereafter, the flask was gently heated to 40 ° C. with stirring in an oil bath for heating and held for 60 minutes. Thereafter, it was heated to 50 ° C. After holding at 50 ° C. for 60 minutes, the particle size was measured with a Coulter counter (manufactured by Coulter Inc .: Multisizer 2), and it was confirmed that aggregated particles having a volume average particle diameter D50v of 4.5 μm were formed. . Further, the temperature of the heating oil bath was raised and held at 52 ° C. for 1 hour. When the particle size was measured, it was confirmed that aggregated particles having D50v of 5.0 μm were formed.
[0158]
-Adhesion process-
60 parts by mass of the resin fine particle dispersion was gently added to the obtained dispersion containing aggregated particles, and the temperature of the heating oil bath was raised and maintained at 54 ° C. for 1 hour. The obtained adhered particles were measured for particle size, and D50v was 5.6 μm.
[0159]
-Fusion process-
After adding a 1 mol / L sodium hydroxide aqueous solution to the obtained liquid containing adhered particles so that the pH becomes 6.0, the stainless steel flask was sealed, and stirring was continued using a magnetic seal while continuing 85. The mixture was gently heated to 0 ° C. and held for 60 minutes, then heated to 96 ° C., and a 1 mol / L nitric acid aqueous solution was added until pH 5.0 and held for 5 hours.
Thereafter, the mixture was cooled, filtered, washed 5 times with ion-exchanged water, and then dried using a vacuum dryer to obtain toner particles 1.
[0160]
(Toner particle 2)
The materials used were the same as those for the toner particles 1 except that the colorant dispersion (1) in the preparation of the toner particles 1 was changed to 60 parts by mass of the colorant dispersion (2).
[0161]
-Aggregation process-
The above materials were mixed and dispersed in a round stainless steel flask with a homogenizer (manufactured by IKA: Ultra Turrax T50) in the same manner as in the case of toner particles 1 while controlling the liquid temperature at 25 ° C. The flask was gently heated to 40 ° C. with stirring for 60 minutes. Thereafter, it was heated to 50 ° C. After holding at 50 ° C. for 60 minutes, the particle size was measured with a Coulter counter (manufactured by Coulter Inc .: Multisizer 2), and it was confirmed that aggregated particles having a D50v of 4.8 μm were formed. Further, the temperature of the heating oil bath was raised and held at 52 ° C. for 1 hour. When the particle size was measured, it was confirmed that aggregated particles having D50v of 5.2 μm were formed.
[0162]
-Adhesion process-
60 parts by mass of the resin fine particle dispersion was gently added to the obtained dispersion containing aggregated particles, and the temperature of the heating oil bath was raised and maintained at 54 ° C. for 1 hour. When the particle size of the obtained adhered particles was measured, D50v was 5.8 μm.
[0163]
-Fusion process-
After adding a 1 mol / L sodium hydroxide aqueous solution to the liquid containing the attached particles until the pH reaches 6.0, the stainless steel flask is sealed and gently stirred up to 85 ° C. while continuing stirring using a magnetic seal. And heated to 96 ° C., 1 mol / L aqueous nitric acid solution was added until pH 5.0 and held for 5 hours. Thereafter, the mixture was cooled, filtered, washed 5 times with ion exchange water, and then dried using a vacuum dryer to obtain toner particles 2.
[0164]
(Toner particle 3)
The materials used were toner particles, except that the colorant dispersion (1) in preparation of the toner particles 1 was changed to 40 parts by weight of the colorant dispersion (3) and 20 parts by weight of the colorant dispersion (4). 1 was the same as the production of 1.
[0165]
-Aggregation process-
The above materials were mixed and dispersed in a round stainless steel flask with a homogenizer (manufactured by IKA: Ultra Turrax T50) in the same manner as in the case of toner particles 1 while controlling the liquid temperature at 25 ° C. While stirring the flask in a bath, it was gently heated to 40 ° C. and held for 60 minutes. Then, it heated to 50 degreeC. After maintaining at 50 ° C. for 60 minutes, the particle size was measured with a Coulter counter (manufactured by Coulter Inc .: Multisizer 2), and it was confirmed that aggregated particles having a D50v of 4.7 μm were formed. Further, the temperature of the heating oil bath was raised and held at 52 ° C. for 1 hour. When the particle size was measured, it was confirmed that aggregated particles having D50v of 4.9 μm were formed.
[0166]
-Adhesion process-
To the obtained dispersion containing aggregated particles, 60 parts by mass of the resin particle dispersion was slowly added, and the temperature of the heating oil bath was raised and maintained at 54 ° C. for 1 hour. When the particle size of the resulting adhered particles was measured, D50v was 5.4 μm.
[0167]
-Fusion process-
After adding a 1 mol / L sodium hydroxide aqueous solution to the liquid containing the adhered particles obtained until the pH reached 6.0, the stainless steel flask was sealed, and stirring was continued using a magnetic seal at 85 ° C. The solution was gently heated to 60 minutes, then heated to 96 ° C., a 1 mol / L nitric acid aqueous solution was added until pH 5.0, and then held for 5 hours. Thereafter, the mixture was cooled, filtered, washed 5 times with ion exchange water, and then dried using a vacuum dryer to obtain toner particles 3.
[0168]
(Toner particle 4)
The materials used were the same as those for toner particles 1 except that the colorant dispersion (1) in the preparation of toner particles 1 was changed to 60 parts by weight of the colorant dispersion (5).
[0169]
-Aggregation process-
The above materials were mixed and dispersed in a round stainless steel flask with a homogenizer (manufactured by IKA: Ultra Turrax T50) in the same manner as in the case of toner particles 1 while controlling the liquid temperature at 25 ° C. While stirring the flask in a bath, it was gently heated to 40 ° C. and held for 60 minutes. Then, it heated to 50 degreeC. After holding at 50 ° C. for 60 minutes, the particle size was measured with a Coulter counter (manufactured by Coulter Co., Ltd .: Multisizer 2), and it was confirmed that aggregated particles having a D50v of 4.5 μm were formed. Further, the temperature of the heating oil bath was raised and held at 52 ° C. for 1 hour. When the particle size was measured, it was confirmed that aggregated particles having a D50v of 4.9 μm were formed.
[0170]
-Adhesion process-
To the obtained dispersion containing aggregated particles, 60 parts by mass of the resin particle dispersion was slowly added, and the temperature of the heating oil bath was raised and maintained at 54 ° C. for 1 hour. The obtained adhered particles were measured for particle size, and D50v was 5.3 μm.
[0171]
-Fusion process-
After adding a 1 mol / L sodium hydroxide aqueous solution to the liquid containing the attached particles until the pH reaches 6.0, the stainless steel flask is sealed and gently stirred up to 85 ° C. while continuing stirring using a magnetic seal. Then, 1 mol / L aqueous nitric acid solution was added until pH 5.0, heated to 96 ° C., and held for 5 hours. Thereafter, the mixture was cooled, filtered, washed 5 times with ion-exchanged water, and then dried using a vacuum dryer to obtain toner particles 4.
[0172]
(Toner particle 5)
In the production of toner particles 1, toner particles 5 were produced in the same manner as in the production of toner particles 1 except that the fusing process was changed as follows.
[0173]
-Aggregation process-
In the case of toner particles 1 using a homogenizer (IKA Corp .: Ultra Turrax T50) while controlling the liquid temperature at 25 ° C. in a round stainless steel flask, using the same materials as those used in the production of toner particles 1 After mixing and dispersing in the same manner as above, the flask was gently heated to 40 ° C. with stirring in an oil bath for heating and held for 60 minutes. Then, it heated to 50 degreeC. After maintaining at 50 ° C. for 60 minutes, the particle size was measured with a Coulter counter (manufactured by Coulter Inc .: Multisizer 2), and it was confirmed that aggregated particles having a D50v of 4.6 μm were formed. Further, the temperature of the heating oil bath was raised and held at 52 ° C. for 1 hour. When the particle size was measured, it was confirmed that aggregated particles having a D50v of 5.1 μm were produced.
[0174]
-Adhesion process-
60 parts by mass of the resin fine particle dispersion was gently added to the obtained dispersion containing aggregated particles, and the temperature of the heating oil bath was raised and maintained at 54 ° C. for 1 hour. When the particle size of the obtained adhered particles was measured, D50v was 5.6 μm.
[0175]
-Fusion process-
After adding a 1 mol / L sodium hydroxide aqueous solution to the obtained liquid containing adhered particles until pH 7.0 is reached, the stainless steel flask is sealed and gently stirred up to 85 ° C. while continuing to stir using a magnetic seal. Heated and held for 60 minutes, then heated to 96 ° C. and held for 5 hours. Thereafter, the mixture was cooled, filtered, washed 5 times with ion-exchanged water, and then dried using a vacuum dryer to obtain toner particles 5.
[0176]
(Toner particle 6)
In the production of toner particles 1, toner particles 6 were produced in the same manner as in the production of toner particles 1 except that the fusing process was changed as follows.
[0177]
-Aggregation process-
In the case of toner particles 1 using a homogenizer (IKA Corp .: Ultra Turrax T50) while controlling the liquid temperature at 25 ° C. in a round stainless steel flask, using the same materials used for the production of toner particles 1 After mixing and dispersing in the same manner as above, the flask was gently heated to 40 ° C. with stirring in an oil bath for heating and held for 60 minutes. Then, it heated to 50 degreeC. After maintaining at 50 ° C. for 60 minutes, the particle size was measured with a Coulter counter (manufactured by Coulter Inc .: Multisizer 2), and it was confirmed that aggregated particles having a D50v of 4.4 μm were formed. Further, the temperature of the heating oil bath was raised and held at 52 ° C. for 1 hour. When the particle size was measured, it was confirmed that aggregated particles with D50v of 5.0 μm were produced.
[0178]
-Adhesion process-
60 parts by mass of the resin fine particle dispersion was gently added to the obtained dispersion containing aggregated particles, and the temperature of the heating oil bath was raised and maintained at 54 ° C. for 1 hour. When the particle size of the obtained adhered particles was measured, D50v was 5.6 μm.
[0179]
-Fusion process-
After adding a 1 mol / L sodium hydroxide aqueous solution to the liquid containing the attached particles until the pH reaches 6.0, the stainless steel flask is sealed and gently stirred up to 85 ° C. while continuing stirring using a magnetic seal. Then, 1 mol / L aqueous nitric acid solution was added until pH 4.0, heated to 96 ° C., and held for 5 hours. Thereafter, the mixture was cooled, filtered, washed 5 times with ion-exchanged water, and then dried using a vacuum dryer to obtain toner particles 6.
[0180]
(Toner particle 7)
Toner particles 7 were produced in the same manner as in the production of toner particles 1 except that the metal salt flocculant was changed as follows in the production of toner particles 1.
[0181]
-Aggregation process-
Among the materials used for the production of the toner particles 1, the metal salt flocculant is composed of 2.0 parts by mass of magnesium chloride (hexahydrate, manufactured by Shonan Wako Pure Chemical Industries, Ltd .: special grade), aluminum sulfate (14-18 hydrate). , Shonan Wako Pure Chemicals Co., Ltd .: special grade) 1.0 part by mass, each material in a round stainless steel flask, while controlling the liquid temperature at 25 ℃, with a homogenizer (IKA company: Ultra Turrax T50) After mixing and dispersing as in the case of toner particles 1, the flask was gently heated to 40 ° C. with stirring in an oil bath for heating and held for 60 minutes. Then, it heated to 50 degreeC. After maintaining at 50 ° C. for 60 minutes, the particle size was measured with a Coulter counter (Multisizer 2 manufactured by Coulter, Inc.), and it was confirmed that aggregated particles having a D50v of 4.4 μm were formed. Further, the temperature of the heating oil bath was raised and held at 52 ° C. for 1 hour. When the particle size was measured, it was confirmed that aggregated particles with D50v of 5.0 μm were produced.
[0182]
-Adhesion process-
To the obtained dispersion containing aggregated particles, 60 parts by mass of the resin particle dispersion was slowly added, and the temperature of the heating oil bath was raised and maintained at 54 ° C. for 1 hour. When the particle size of the obtained adhered particles was measured, D50v was 5.6 μm.
[0183]
-Fusion process-
After adding a 1 mol / L sodium hydroxide aqueous solution to the liquid containing the attached particles until the pH reaches 6.0, the stainless steel flask is sealed and gently stirred up to 85 ° C. while continuing stirring using a magnetic seal. Then, 1 mol / L aqueous nitric acid solution was added until pH 4.0, heated to 96 ° C., and held for 5 hours. Thereafter, the mixture was cooled, filtered, washed 5 times with ion exchange water, and then dried using a vacuum dryer to obtain toner particles 7.
[0184]
(Toner particle 8)
Toner particles 8 were prepared in the same manner as toner particles 1 except that the mixing and aggregating steps were changed as follows in the preparation of toner particles 1.
[0185]
-Aggregation process-
A material similar to that used in the production of toner particles 1 was mixed and dispersed in a round stainless steel flask while controlling the liquid temperature at 25 ° C. with a homogenizer (manufactured by IKA: Ultra Turrax T50), and then heated. The flask was gently heated to 45 ° C. with stirring in an oil bath for 60 minutes. Then, it heated to 55 degreeC. After maintaining at 55 ° C. for 2 hours, the particle size was measured with a Coulter counter (manufactured by Coulter Inc .: Multisizer 2), and it was confirmed that aggregated particles having a D50v of 7.5 μm were formed. Further, the temperature of the heating oil bath was raised and maintained at 56 ° C. for 1 hour. When the particle size was measured, it was confirmed that aggregated particles having D50v of 8.5 μm were formed.
[0186]
-Adhesion process-
To the dispersion containing the aggregated particles, 60 parts by mass of the resin fine particle dispersion (1) was slowly added, and the temperature of the heating oil bath was raised and maintained at 57 ° C. for 1 hour. When the particle size of the resulting adhered particles was measured, D50v was 10.5 μm.
[0187]
-Fusion process-
After adding a 1 mol / L sodium hydroxide aqueous solution to the liquid containing the attached particles until the pH reaches 6.0, the stainless steel flask is sealed and gently stirred up to 85 ° C. while continuing stirring using a magnetic seal. Then, 1 mol / L aqueous nitric acid solution was added until pH 5.0, heated to 96 ° C., and held for 5 hours. Thereafter, the mixture was cooled, filtered, washed 5 times with ion exchange water, and then dried using a vacuum drier to obtain toner particles 8.
[0188]
(Toner particle 9)
In the production of the toner particles 1, the ion exchange water is changed to 800 parts by mass, and the flocculant is changed to 0.5 parts by mass of a cationic surfactant (manufactured by Kao: Sanizol B50) instead of the metal salt flocculant. A toner particle 9 was produced in the same manner as in the production of the toner particle 1 except for the above changes.
[0189]
-Aggregation process-
The above materials were mixed and dispersed in a round stainless steel flask with a homogenizer (manufactured by IKA: Ultra Turrax T50) in the same manner as in the case of toner particles 1 while controlling the liquid temperature at 30 ° C. While stirring the flask in a bath, it was gently heated to 40 ° C. and held for 60 minutes. Then, it heated to 52 degreeC. After holding at 52 ° C. for 60 minutes, the particle size was measured with a Coulter counter (manufactured by Coulter Inc .: Multisizer 2), and it was confirmed that aggregated particles having a D50v of 4.5 μm were formed. Further, the temperature of the heating oil bath was raised and held at 54 ° C. for 1 hour. When the particle size was measured, it was confirmed that aggregated particles having a D50v of 4.9 μm were generated.
[0190]
-Adhesion process-
To the obtained dispersion containing aggregated particles, 60 parts by mass of the resin fine particle dispersion was slowly added, and the temperature of the heating oil bath was raised and maintained at 55 ° C. for 1 hour. When the particle size of the obtained adhered particles was measured, D50v was 5.5 μm.
[0191]
-Fusion process-
After adding a 1 mol / L sodium hydroxide aqueous solution to the obtained liquid containing adhered particles until pH 6.0 is reached, the stainless steel flask is sealed and heated to 96 ° C. while continuing stirring using a magnetic seal. 1 mol / L nitric acid was added until pH 5.0 and held for 5 hours. Thereafter, the mixture was cooled, filtered, washed 5 times with ion exchange water, and then dried using a vacuum dryer to obtain toner particles 9.
[0192]
(Toner particle 10)
In the production of toner particles 1, toner particles 10 were produced in the same manner as in the production of toner particles 1 except that the pH in the fusion process was changed as follows.
[0193]
-Aggregation process-
In the case of toner particles 1 using a homogenizer (manufactured by IKA: Ultra Turrax T50) while controlling the liquid temperature at 30 ° C. in a round stainless steel flask, using the same material as that used in the production of toner particles 1 After mixing and dispersing in the same manner as above, the flask was gently heated to 40 ° C. with stirring in an oil bath for heating and held for 60 minutes. Then, it heated to 50 degreeC. After maintaining at 50 ° C. for 60 minutes, the particle size was measured with a Coulter counter (manufactured by Coulter Inc .: Multisizer 2), and it was confirmed that aggregated particles having a D50v of 4.7 μm were formed. Further, the temperature of the heating oil bath was raised and held at 52 ° C. for 1 hour. When the particle size was measured, it was confirmed that aggregated particles with D50v of 5.0 μm were produced.
[0194]
-Adhesion process-
To the obtained dispersion containing aggregated particles, 60 parts by mass of the resin particle dispersion was gently added, and the temperature of the heating oil bath was raised and maintained at 54 ° C. for 1 hour. When the particle size of the obtained adhered particles was measured, D50v was 5.7 μm.
[0195]
-Fusion process-
After adding a 1 mol / L sodium hydroxide aqueous solution to the obtained liquid containing adhered particles until pH 8.0 is reached, the stainless steel flask is sealed and heated to 96 ° C. while continuing stirring using a magnetic seal. The solution was held for 5 hours without adjusting the pH. Thereafter, the mixture was cooled, filtered, washed 5 times with ion exchange water, and then dried using a vacuum dryer to obtain toner particles 10.
[0196]
(Toner particles 11)
In the production of toner particles 1, toner particles 11 were produced in the same manner as in the production of toner particles 1 except that the pH in the fusion process was changed as follows.
[0197]
-Aggregation process-
In the case of toner particles 1 using a homogenizer (IKA Corp .: Ultra Turrax T50) while controlling the liquid temperature at 30 ° C. in a round stainless steel flask, the same material as that used for the production of toner particles 1 is used. After mixing and dispersing in the same manner, the flask was gently heated to 40 ° C. with stirring in an oil bath for heating and held for 60 minutes. Then, it heated to 50 degreeC. After maintaining at 50 ° C. for 60 minutes, the particle size was measured with a Coulter counter (manufactured by Coulter Inc .: Multisizer 2), and it was confirmed that aggregated particles having a D50v of 4.7 μm were formed. Further, the temperature of the heating oil bath was raised and held at 52 ° C. for 1 hour. When the particle size was measured, it was confirmed that aggregated particles having D50v of 5.0 μm were formed.
[0198]
-Adhesion process-
To the obtained dispersion containing aggregated particles, 60 parts by mass of the resin fine particle dispersion was gently added, and the temperature of the heating oil bath was raised and maintained at 54 ° C. for 1 hour. When the particle size of the obtained adhered particles was measured, D50v was 5.6 μm.
[0199]
-Fusion process-
After adding a 1 mol / L sodium hydroxide aqueous solution to the liquid containing the attached particles until the pH reaches 6.0, the stainless steel flask is sealed, and the stirring is continued using a magnetic seal up to 96 ° C. Heated, 1 mol / L nitric acid was added until pH 3.5 and held for 5 hours. Thereafter, the mixture was cooled, filtered, washed 5 times with ion-exchanged water, and then dried using a vacuum dryer to obtain toner particles 11.
[0200]
(Toner particles 12)
In the production of the toner particles 1, the ion exchange water is changed to 800 parts by mass, and the flocculant is changed to 0.5 parts by mass of a cationic surfactant (manufactured by Kao: Sanizol B50) instead of the metal salt flocculant. Toner particles 12 were prepared in the same manner as toner particles 1 except that the steps were changed as follows.
[0201]
-Aggregation process-
The above materials were mixed and dispersed in a round stainless steel flask with a homogenizer (manufactured by IKA: Ultra Turrax T50) in the same manner as in the case of toner particles 1 while controlling the liquid temperature at 30 ° C. The flask was rapidly heated to 50 ° C. while stirring at a rapid speed in a bath and held for 60 minutes. Then, it heated to 52 degreeC. After maintaining at 54 ° C. for 30 minutes, the particle size was measured with a Coulter counter (manufactured by Coulter Inc .: Multisizer 2), and it was confirmed that aggregated particles having a D50v of 4.5 μm were formed. Further, the temperature of the heating oil bath was raised and maintained at 56 ° C. for 30 minutes. When the particle size was measured, it was confirmed that aggregated particles having a D50v of 4.9 μm were generated.
[0202]
-Adhesion process-
To the obtained dispersion containing aggregated particles, 60 parts by mass of the resin fine particle dispersion was slowly added, and the temperature of the heating oil bath was raised and maintained at 55 ° C. for 1 hour. When the particle size of the obtained adhered particles was measured, D50v was 5.5 μm.
[0203]
-Fusion process-
After adding a 1 mol / L sodium hydroxide aqueous solution to the obtained liquid containing adhered particles until pH 6.0 is reached, the stainless steel flask is sealed and heated to 96 ° C. while continuing stirring using a magnetic seal. 1 mol / L nitric acid was added until pH 5.0 and held for 5 hours. Thereafter, the mixture was cooled, filtered, washed 5 times with ion-exchanged water, and then dried using a vacuum dryer to obtain toner particles 12.
[0204]
(Toner particles 13)
In the production of the toner particles 1, the ion exchange water is changed to 800 parts by mass, and the flocculant is changed to 0.5 parts by mass of a cationic surfactant (manufactured by Kao: Sanizol B50) instead of the metal salt flocculant. Toner particles 13 were prepared in the same manner as toner particles 1 except that the steps were changed as follows and the attaching step was omitted.
[0205]
-Aggregation process-
The above materials were mixed and dispersed in a round stainless steel flask using a homogenizer (manufactured by IKA: Ultra Turrax T50) in the same manner as in the case of toner particles 1 while controlling the liquid temperature at 40 ° C. The flask was rapidly heated to 50 ° C. while stirring at a rapid speed in a bath and held for 60 minutes. Then, it heated to 52 degreeC. After holding at 54 ° C. for 60 minutes, the particle size was measured with a Coulter counter (manufactured by Coulter Inc .: Multisizer 2), and it was confirmed that aggregated particles having a D50v of 5.2 μm were formed. Further, the temperature of the heating oil bath was raised and maintained at 56 ° C. for 60 minutes. When the particle size was measured, it was confirmed that aggregated particles having a D50v of 5.7 μm were produced.
[0206]
-Fusion process-
After adding a 1 mol / L sodium hydroxide aqueous solution to the obtained liquid containing adhered particles until pH 6.0 is reached, the stainless steel flask is sealed and heated to 96 ° C. while continuing stirring using a magnetic seal. 1 mol / L nitric acid was added until pH 5.0 and held for 5 hours. Thereafter, the mixture was cooled, filtered, washed 5 times with ion exchange water, and then dried using a vacuum dryer to obtain toner particles 13.
[0207]
[Evaluation of toner characteristics for electrostatic image development]
The following characteristics evaluation was performed on the toner particles after drying obtained as described above.
[0208]
-Toner particle size, GSDv, GSDp-
The particle size (D50v) of the agglomerated particles and toner was confirmed with a Coulter counter (manufactured by Nikka Kikai Co., Ltd .: TAII). Moreover, GSDv, GSDp, etc. were calculated | required as mentioned above from the obtained volume particle size distribution and number particle size distribution. Furthermore, the ratio of the particle | grains more than twice D50v in a volume particle size distribution and the ratio of 3/5 or less of D50n in a number particle size distribution were calculated | required.
[0209]
-Average circularity, average circularity standard deviation-
An average circularity (equivalent circumference per circle / perimeter) and a circularity standard deviation were determined by a flow type particle shape measuring instrument (FPIA-2000: manufactured by Sysmec Corporation).
[0210]
-Ratio of coarse pigment particles in toner-
Take a cross-sectional photograph of the toner (transmission electron microscope, 5000 times) into a Luzex image analyzer (Luzex FT: manufactured by Nireco), and analyze the number% of pigment particle aggregates with a maximum length of 1 μm or more in one toner. Was obtained as an average value for 100 or more toners.
[0211]
-Quantitative elemental analysis in toner-
Using a fluorescent X-ray analyzer (XRF1800: manufactured by Shimadzu Corporation), the total detected elements in the toner are set to 100% by fluorescent X-ray analysis (XRF), and the Group IA elements (excluding hydrogen) in all measured elements ), Group IIA elements, group IIIB elements, and group IVB elements (excluding carbon).
[0212]
-Surface wax exposure-
The amount of surface wax was quantified by C1S peak separation by X-ray photoelectron spectroscopy (XPS) using X-ray photoelectron spectroscopy (JPS-9000: manufactured by JEOL Ltd.).
The results measured for each toner particle are shown in Table 1.
[0213]
[Table 1]

[0214]
[Manufacture of electrostatic image developer]
0.5 parts by mass of hydrophobic silica (TS720: manufactured by Cabot) was added to 50 parts by mass of each of the obtained toner particles 1 to 13, and blended by a sample mill.
This blend was weighed so that the toner concentration was 5% by mass with respect to a ferrite carrier having a volume average particle size of 50 μm coated with 1% by mass of polymethyl methacrylate (manufactured by Soken Chemical Co., Ltd.), and stirred for 5 minutes with a ball mill. -Developers 1 to 13 were prepared by mixing.
[0215]
[Preparation of charging roll]
A stainless steel shaft (diameter: 8 mm, length: 350 mm) was used as the conductive support, and an intermediate resistance elastic layer was formed around the shaft by the following blending and processing method.
[0216]
-GECO-based epichlorohydrin raw rubber (Epichroma CG102: manufactured by Daiso, composition ratio: epichlorohydrin 40 mol%, ethylene oxide 56 mol%, allyl glycidyl ether 4 mol%) 100 parts by mass
・ 30 parts by mass of calcium carbonate (Tama Pearl TR-222H: manufactured by Okutama Kogyo)
・ Sub (Neo factis U-8: manufactured by Tenma Sub Chemical) 10 parts by mass
・ 1.0 part by mass of tetramethylammonium chloride (Nippon Resin: Elegance R115)
・ 0.5 parts by mass of stearic acid (fatty acid SA-200: manufactured by Asahi Denka)
・ Vulcanization accelerator (Noxera TT: Ouchi Shinsei Chemical) 1.0 parts by mass
・ Vulcanization accelerator (Noxera DM: Ouchi Shinsei Chemical) 1.5 parts by mass
・ Vulcanization accelerator (Barnock R: manufactured by Ouchi Shinsei Chemical) 1.0 parts by mass
・ Vulcanizing agent (Sulfax: Tsurumi Chemical) 0.25 parts by mass
[0217]
After kneading the compound to obtain a compound having a uniform composition, the surface of the stainless steel shaft is subjected to primary vulcanization (steam can, 4.5 × 10²kPa, 150 ° C. × 1 hour) and secondary vulcanization (155 ° C. × 7 hours) to form an outer diameter of 14 mm × length of 310 mm to provide a roller-like medium resistance elastic layer. The middle resistance elastic layer has an electric resistance of 2 × 10.⁷The Ω · cm and the roller rubber hardness were 38 degrees (JIS A).
[0218]
Next, 80 parts by mass of linear polyester resin (Byron 30SS: manufactured by Toyobo Co., Ltd.) and 20 parts by mass of melamine resin (Super Becamine G-821-60: manufactured by Dainippon Ink Co., Ltd.) (FW200: manufactured by Degussa) 5 parts by mass and fluororesin fine powder (Lublon L-5: manufactured by Daikin Industries, Ltd.) 10 parts by mass were mixed and dispersed using a sand mill.
[0219]
Next, the dispersion was diluted with xylene (a ratio of 150 parts by mass of xylene with respect to 100 parts by mass of the dispersion) to prepare a coating material for forming a surface layer, and the viscosity was adjusted. After masking the shaft leaving a gap corresponding to the film thickness from the portion where the shaft and the end surface of the elastic layer are in contact, the medium resistance elastic layer is formed using a bell-type electrostatic coating machine (manufactured by Landsburg Industry). After forming a surface layer on the entire surface of the elastic layer so that the film thickness upon drying was 35 μm, the surface layer was dried at 160 ° C. for 30 minutes to prepare a charging roll.
[0220]
With respect to this charging roll, the volume resistance was measured at an applied voltage of 100 V using a resistance measurement cell (trade name: 16008A, manufactured by YHP) and a resistance meter (trade name: R8340A, manufactured by Advantest). The volume resistance of a sheet (corresponding to the layer structure of the charging roll) in which the surface layer is provided on the surface of the medium resistance elastic layer in the same manner as the roll is 10^5.2Ω · cm was indicated. The volume resistivity of the surface layer is 10^4.5The difference in volume resistance between the charging roll and the surface layer was 0.7 digits. Moreover, it was 2200V when the voltage which causes a discharge dielectric breakdown was measured. At this time, the surface coverage was 95.6%. The surface coverage was calculated using the following formula.
Surface coverage (%) = [(total surface area of surface layer) / (total surface area of charging roll)] × 100
[0221]
[Preparation of transfer roll]
A two-layer structure transfer roll was produced as follows.
To 100 parts by mass of a rubber material (EPDM EP33: manufactured by Nippon Synthetic Rubber Co., Ltd.) containing 1 part by mass of sulfur as a vulcanizing agent and 0.6 parts by mass of tetramethyltylium disulfide as a vulcanization accelerator, Ketchien Black (Lion Aguso Co., Ltd., volume resistance ρv: 10^6.3Ωcm) 12 parts by mass and FT carbon (manufactured by Asahi Carbon Co., Ltd.) 20 parts by mass, and as a foaming agent, 15 parts by mass of a foamed rubber compound having a composition of 6 parts by mass of benzenesulfonyl hydrazide were added. Kneaded.
[0222]
Next, this kneaded product was extruded into a tube shape by an extruder, and this was extruded in a vulcanizing can at a temperature of 126 ° C. and a pressure of 1.5 kg / cm.²The foam was heated and foamed under the pressurized steam of G. A heat formed by inserting a stainless steel shaft (diameter: 8 mm, length: 350 mm) into the obtained foamed elastic body and further dispersing an ion conductive polymer in polyvinylidene fluoride (PVDF) resin having a thickness of 0.1 mm. By covering the shrinkable tube at 120 ° C., a transfer roll having a layer thickness of 5 mm was obtained.
[0223]
The foamed elastic body (underlying layer) had an Asker C hardness of 60 ° and a roll hardness of 40 ° Asker C hardness. The volume resistivity of the polyvinylidene fluoride (PVDF) is 10^8.2Ωcm, surface resistance is 10^7.5Ω / □. Moreover, the PVDF tube which disperse | distributes an ion conductive polymer mixes 40 mass% of Pelestat 6321 chip | tip made from Sanyo Chemical Industries, Ltd. as an ion conductive polymer to PVDF powder, and knead | mixes this with a twin-screw extruder. Then, it is pelletized and obtained by extruding while stretching it into a tube shape with a single screw extruder.
[0224]
<Example 1>
A copying machine (Laser Wind 3310: manufactured by Fuji Xerox Co., Ltd.) was used as an evaluation machine, and the charging roll was installed so as to rotate in contact with the photosensitive member. Only a DC power supply of 750 V and a 2 kHz AC power supply of 2 kHz were applied. The transfer roll was also installed at the same time.
[0225]
The developer 1 was set as a developer in the developing unit of the copying machine, and a continuous running test for 4000 continuous sheets was performed in an environment of 23 ° C. and 55% RH. The toner charge amount maintainability, image quality, paper peelability, transfer / charge roll contamination, image quality defects (hollow character, white spots at the edges), etc., were evaluated.
[0226]
-Toner charge maintenance-
The toner charge amount at the initial stage and after the running test was measured by a charge amount measuring device TB200 (manufactured by Toshiba Corporation) and evaluated according to the following criteria.
[0227]
◯: Charge amount decrease after running test is less than 5 μC / g
Δ: Decrease in charge after running test is 5 μC / g or more and less than 10 μC / g
X: Charge amount decrease after running test is 10 μC / g or more
[0228]
-Image density-
A solid image was output after the running test, and the image density uniformity was visually evaluated according to the following criteria.
○: The entire surface is uniform and there is no problem.
Δ: Density unevenness is observed.
X: The density is decreased as a whole.
[0229]
-Cover-
The white background image after the running test was evaluated visually according to the following criteria.
○: No fogging.
Δ: Slight fogging is observed.
X: A considerable amount of fog is seen and there is a problem in quality.
[0230]
-Granularity-
A halftone image after the running test was output and visually evaluated according to the following criteria.
○: The entire surface is uniform and there is no problem.
Δ: Slight roughness is observed.
[0231]
-Transfer efficiency-
The transfer efficiency after the initial test and the running test was obtained and evaluated according to the following criteria. The transfer efficiency was determined by measuring the amount of toner (TMA) per unit area transferred to the recording paper and the amount of toner (DMA) per unit area not yet transferred remaining on the surface of the photoconductor for a solid image. Calculated by the formula.
Transfer efficiency (%) = [(TMA) / (TMA + DMA)] × 100
[0232]
○: Transfer efficiency hardly decreases.
Δ: Transfer efficiency decreased by 5% or more and less than 10%.
X: Transfer efficiency decreased by 10% or more.
[0233]
-Hollow characters, white spots-
The thin line (English) image after the running test was evaluated visually according to the following criteria.
○: Good
Δ: Minor occurrence
×: Occurrence
[0234]
−Dirty condition of roll−
After the running test, the charging roll and the transfer roll were removed, and the toner adhering to the surface was transferred with a scotch tape, and visually evaluated according to the following criteria.
The above evaluation results are shown in Table 2.
[0235]
<Examples 2-7, Comparative Examples 1-6>
In Example 1, Examples 2 to 7 were carried out in the same manner as Example 1 except that Developers 2 to 7 were used instead of Developer 1, respectively.
Further, in Examples 1, Comparative Examples 1 to 6 were performed in the same manner as Example 1 except that Developers 8 to 13 were used instead of Developer 1, respectively.
The results are summarized in Table 2.
[0236]
[Table 2]

[0237]
As shown in the results of Table 2, when the developer of the example is used, there are almost no toner chargeability and image quality defects, and the toner performance is not only stable, but also contamination of the charging roll and transfer roll. It turns out that there is no. On the other hand, when the developer of the comparative example was used, some problem occurred in the toner performance and the contamination. In particular, in Comparative Examples 3 to 6 having a large amount of coarse pigment particles, fogging due to a decrease in charge amount, density unevenness, roll contamination, a decrease in transfer efficiency, and image defects occurred, resulting in extremely poor results.
[0238]
【The invention's effect】
According to the present invention, there are provided an image forming method and an image forming apparatus that are excellent in environmental stability and repetitive stability, have good charging performance and transfer performance, and can simultaneously satisfy high image quality and high reliability. Can do.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an electrophotographic apparatus which is an example of an image forming apparatus of the present invention.
[Explanation of symbols]
1 Electrostatic latent image carrier
2 Cleaning blade
3 Holding members
10 Electrophotographic photoreceptor (electrostatic latent image carrier)
11 Charger (charging means)
12 Power supply
13 Image input device (electrostatic latent image forming means)
14 Developer (Developing means)
15 Transfer device (transfer means)
16 Cleaning device (cleaning means)
17 Static eliminator
18 Fixing device
19 Blade (cleaning blade)
20 Recorded object
21 box

Claims (4)

A charging process in which a charging roll is brought into contact with the electrostatic latent image carrier and a voltage is applied from the outside for charging, an electrostatic latent image forming process for forming an electrostatic latent image, and the electrostatic latent image is electrostatically charged. A toner image forming step of developing the image using an image developer, and an image forming method comprising:
The electrostatic charge image developer contains an electrostatic charge image developing toner satisfying the following conditions (a), (b), (c), (d), and (e): Method.
(A) The volume average particle size D50v of the toner is in the range of 3 to 10 μm, and the volume average particle size distribution index GSDv and the number average particle size distribution index GSDp are both 1.25 or less.
(B) The particle size ratio of the number particle size distribution index GSDp-under on the small particle size side is 1.27 or less and the particle size of the particle size of 3/5 or less of the number average particle size D50n is 10% by number or less, and the volume average particle size The ratio of particles having a particle size of at least twice D50v is 10% by volume or less.
(C) The average circularity is in the range of 0.940 to 0.980, and the average circularity standard deviation is 0.1 or less.
(D) The number of aggregates of pigment particles having a maximum length of 1 μm or more observed in a toner cross-sectional image observed with a transmission electron microscope is 5% by number or less in one toner, and the pigment particles in the toner The average dispersion diameter is in the range of 0.1 to 0.7 μm.
(E) Group IA elements (excluding hydrogen), Group IIA elements, Group IIIB elements, and Group IVB elements (carbon) when the total intensity ratio of elements detected by fluorescent X-ray analysis is 100% The ratio of (except for) is in the range of 0.1 to 10%. The image forming method according to claim 1, further comprising a transfer step of transferring the toner image on the surface of the electrostatic latent image carrier to a transfer body, wherein the transfer member is a transfer roll . A charging unit that makes a charging roll come into contact with the electrostatic latent image carrier and applies a voltage from the outside to perform charging; an electrostatic latent image forming unit that forms an electrostatic latent image; and An image forming apparatus comprising: a toner image forming unit that visualizes an image using an image developer;
The electrostatic charge image developer contains an electrostatic charge image developing toner satisfying the following conditions (a), (b), (c), (d), and (e): Equipment .
(A ) The volume average particle size D50v of the toner is in the range of 3 to 10 μm, and the volume average particle size distribution index GSDv and the number average particle size distribution index GSDp are both 1.25 or less .
( B) The number average particle size distribution index GSDp- under is 1.27 or less, and the particle ratio of the particle size of 3/5 or less of the number average particle size D50n is 10% by number or less, and the volume average particle size The ratio of particles having a particle size of at least twice D50v is 10% by volume or less .
( C) The average circularity is in the range of 0.940 to 0.980, and the average circularity standard deviation is 0.1 or less .
( D) The number of aggregates of pigment particles having a maximum length of 1 μm or more observed in a toner cross-sectional image observed with a transmission electron microscope is 5% by number or less in one toner, and the pigment particles in the toner The average dispersion diameter is in the range of 0.1 to 0.7 μm .
( E) Group IA element (excluding hydrogen), Group II A element, Group III B element, and Group IV B group when the total intensity ratio of elements detected by fluorescent X-ray analysis is 100% The ratio of elements (excluding carbon) is in the range of 0.1 to 10% . 4. The image forming apparatus according to claim 3, further comprising transfer means for transferring the toner image on the surface of the electrostatic latent image carrier to a transfer body, wherein the transfer member is a transfer roll .

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