JP2008070577A - Toner for electrostatic charge image development, image forming method, and method for manufacturing the toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide toner showing satisfactory high picture quality and low temperature fixability of an image, free from isolation of an additive even in a long-term use and having high durability, a small particle diameter and a narrow particle size distribution, and a method for manufacturing the toner. <P>SOLUTION: The toner for electrostatic charge image development is obtained by mixing two kinds of external additive inorganic particles having different BET specific surface areas, wherein the first additive comprises hydrophobic silica having a BET specific surface area of 80 to 200 m<SP>2</SP>/g, and the second additive has a BET specific surface area smaller than that of the first additive. The toner has a number average particle diameter (Dn) of 2.5 μm to 4.5 μm and a particle size distribution index (Dv/Dn) of 1.0 to 1.3, and is obtained by preliminarily adding 50 to 100% of the whole weight of the second additive to be fed with toner base particles and mixing (first-stage mixing) it in a mixing machine, then adding the rest of the second additive and the entire amount of the first additive and mixing (second-stage mixing) it in a mixing machine. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a toner for developing an electrostatic image used for forming an electrophotographic image for developing an electrostatic latent image, and a method for producing the same.

  In general, the toner is a particle mainly composed of a binder resin and a colorant, and further containing a charge control agent and a fixing aid as necessary. Usually, the particle diameter is in the range of several to several tens of microns. This toner is generally produced by a so-called pulverization method in which a colorant such as a dye, pigment or magnetic substance is mixed and melted in a thermoplastic resin, and the colorant is uniformly dispersed in the thermoplastic resin and then pulverized and classified. Has been.

  In recent years, image forming apparatuses using electrophotography have become widely used not only as office copy machines for copying text documents but also as high-quality full-color output and high-definition output of computers. . Further, along with the generalization of computers, printers are used in the personal field, and accordingly, there has been a demand for lowering the fixing temperature in order to reduce power consumption.

  For example, LED or LBP printers have become the mainstream in the recent market for printer devices, and the direction of technology is higher resolution, that is, what was conventionally 240, 300 dpi has become 400, 600, 800 dpi. Accordingly, the development method is also required to have higher definition. In addition, copiers are also becoming more sophisticated, and therefore are moving toward digitalization. Since this method is mainly a method of forming an electrostatic charge image with a laser, it is also proceeding in the direction of high resolution, and here again, a high-resolution and high-definition developing method is required as in the case of a printer. . For this reason, the particle size of the toner has been reduced, and Patent Document 1 (Japanese Patent Laid-Open No. 1-112253), Patent Document 2 (Japanese Patent Laid-Open No. 1-191156), and Patent Document 3 (Japanese Patent Laid-Open No. 2-214156). ), Patent Document 4 (Japanese Patent Laid-Open No. 2-284158), Patent Document 5 (Japanese Patent Laid-Open No. 3-181952), Patent Document 6 (Japanese Patent Laid-Open No. 4-162048), and the like. Small toners have been proposed. Regarding the sharpness of characters, if the weight average diameter of the toner is reduced to 6.0 μm or less, the sharpness of characters is slightly improved, but the fluidity of the toner is remarkably lowered, and particularly the density of solid black images is lowered. Realize. Further, the fogging phenomenon occurs due to the development of the toner on the non-image portion as the diameter decreases.

Further, as one means for ensuring the fluidity of the toner, an inorganic fine powder subjected to a hydrophobizing treatment in Patent Document 7 (Japanese Patent Laid-Open No. 5-66608), Patent Document 8 (Japanese Patent Laid-Open No. 4-9860), or the like. After the hydrophobization treatment, inorganic fine powder treated with silicone oil or the like is added, or Patent Document 9 (Japanese Patent Laid-Open No. 61-249059), Patent Document 10 (Japanese Patent Laid-Open No. Hei 4-264453), Patent Document 11 ( JP-A-5-346682) discloses a method in which a hydrophobic treated inorganic fine powder and a silicone oil treated inorganic fine powder are used in combination.
In Patent Document 12 (Japanese Patent No. 3230046), a specific additive is combined with small-diameter toner particles, and in Patent Document 13 (Patent No. 3639714), the distribution of small-diameter toner particles of 2 μm or less is defined. The toner particles maintain good fluidity and improve the balance of character sharpness, solid black density, and character dropout, but the adhesion of additives over a long period of time is constant especially in systems using recycled toner. Durability is not improved because it is not maintained.

Japanese Patent Laid-Open No. 1-112253 JP-A-1-191156 JP-A-2-214156 JP-A-2-284158 Japanese Patent Laid-Open No. 3-181952 JP-A-4-162048 JP-A-5-66608 Japanese Patent Laid-Open No. 4-9860 JP-A 61-249059 JP-A-4-264453 JP-A-5-346682 Japanese Patent No. 3230046 Japanese Patent No. 3639714

  An object of the present invention is a toner for developing an electrostatic image having a small particle size and a narrow particle size distribution that satisfies both high image quality and low-temperature fixability at the same time. It is to provide a high toner and a manufacturing method thereof.

  In a toner having a small particle size and a narrow particle size distribution, the mixing state of the toner base particles and the additive is adjusted by combining a specific mixing mode of the toner base particles and the additive and a specific additive. By fixing the additive to the toner base particles in such a state, it has been found that the additive is not liberated in long-term use, and there is no image unevenness and white stripes in long-term use, and a highly durable toner can be obtained. It was.

That is, the present invention relates to (1) “additives that are two kinds of inorganic fine particles having different BET specific surface area values by using a mixer that uses mechanical energy to toner base particles containing at least a colorant and a binder resin. A toner for developing an electrostatic image obtained by mixing, wherein the first additive is hydrophobic silica having a BET specific surface area of 80 to 200 m ² / g, and the second additive is more than the first additive. The toner has a small BET specific surface area, and the toner has a number average particle diameter (Dn) of 2.5 μm to 4.5 μm and a particle size distribution index (Dv / Dn) of 1.0 to 1.3. 50 to 100% of the total charge part of the particles and the second additive are added first and mixed by a mixer (first stage mixing), then the remaining total amount of the second additive and the first additive The process of adding all the additives and mixing with a mixer (two steps Mixing) toner for developing electrostatic images which is characterized in that it is obtained by "
(2) “The binder resin contains a polyester resin, and the polyester resin has the following formula (1):

で示される化合物またはその酸無水物を用いて合成されたポリエステル樹脂を含有するものであることを特徴とする前記第（１）項に記載の静電荷像現像用トナー」、
（３）「前記第２の添加剤が疎水性シリカ、酸化チタン、酸化アルミナ、酸化ジルコニウムのいずれかであることを特徴とする前記第（１）項または第（２）項に記載の静電荷像現像用トナー」、
（４）「前記混合が、回転羽根を有する混合装置を用いて行うものであり、前記回転羽根の周速が一段目混合において３〜１０ｍ／ｓであり二段目混合が２０〜６０ｍ／ｓである工程により得られたことを特徴とする前記第（１）項乃至第（３）項の何れかに記載の静電荷像現像用トナー」により達成される。
また、本発明は、（５）「少なくとも着色剤と結着樹脂を含有するトナー母体粒子に、機械的なエネルギーを用いる混合機により、ＢＥＴ比表面積値の異なる２種類の添加剤を混合して静電荷像現像用トナーを得る静電荷像現像用トナーの製造方法であって、第１の添加剤はＢＥＴ比表面積が８０〜２００ｍ^２／ｇの疎水性シリカであり、第２の添加剤は第１の添加剤よりもＢＥＴ比表面積が小さく、該トナーは、個数平均粒子径（Ｄｎ）が２．５μｍ乃至４．５μｍであり、粒度分布指数（Ｄｖ／Ｄｎ）が１．０乃至１．３であり、トナー母体粒子と第２の添加剤の全投入重量部のうちの５０〜１００％とを先添加し混合機により混合し、（一段目混合）、ついで、第２の添加剤の残り全量と第１の添加剤全量を加え混合機により混合する工程（二段目混合）を含む静電荷像現像用トナーの製造方法」、
（６）「前記結着樹脂がポリエステル樹脂を含有し、該ポリエステル樹脂が、下記式（１）

The electrostatic charge image developing toner according to item (1), which comprises a polyester resin synthesized using a compound represented by the following formula or an acid anhydride thereof:
(3) The electrostatic charge according to item (1) or item (2), wherein the second additive is any one of hydrophobic silica, titanium oxide, alumina oxide, and zirconium oxide. Image developing toner ",
(4) “The mixing is performed using a mixing device having rotating blades, the peripheral speed of the rotating blades is 3 to 10 m / s in the first stage mixing, and the second stage mixing is 20 to 60 m / s. It is achieved by the electrostatic image developing toner according to any one of items (1) to (3), which is obtained by the process described above.
In the present invention, (5) “two types of additives having different BET specific surface area values are mixed with a toner base particle containing at least a colorant and a binder resin by a mixer using mechanical energy. A method for producing an electrostatic image developing toner for obtaining an electrostatic image developing toner, wherein the first additive is hydrophobic silica having a BET specific surface area of 80 to 200 m ² / g, and the second additive is The toner has a BET specific surface area smaller than that of the first additive, the toner has a number average particle diameter (Dn) of 2.5 μm to 4.5 μm, and a particle size distribution index (Dv / Dn) of 1.0 to 1. 3, 50 to 100% of the toner base particles and the total added weight part of the second additive are first added and mixed by a mixer (first stage mixing), and then the second additive is added. Add the entire remaining amount and the first additive and mix with a mixer. Extent method for producing a toner for developing electrostatic images comprising (second stage mixing) ",
(6) “The binder resin contains a polyester resin, and the polyester resin is represented by the following formula (1):

で示される化合物またはその酸無水物を用いて合成された非線状ポリエステル樹脂を含有するものであることを特徴とする前記第（５）項に記載の静電荷像現像用トナーの製造方法」、
（７）「第２の添加剤が疎水性シリカ、酸化チタン、酸化アルミナ、酸化ジルコニウムのいずれかであることを特徴とする前記第（５）項または第（６）項に記載の静電荷像現像用トナーの製造方法」、
（８）「前記混合が、回転羽根を有する混合装置を用いて行うものであり、前記回転羽根の周速が一段目混合において３〜１０ｍ／ｓであり二段目混合が２０〜６０ｍ／ｓであることを特徴とする前記第（５）項乃至第（７）項の何れかに記載の静電荷像現像用トナーの製造方法」により達成される。
また、本発明は、（９）「外部より帯電部材に電圧を印加し被帯電体に帯電を行う帯電工程と、帯電している被帯電体に静電荷像を形成する工程と、静電荷像を現像手段の現像スリーブからトナー画像を形成する現像工程と、外部より転写部材に電圧を印加しトナー画像を転写体上に転写する転写手段を用いた転写工程と、転写後の被帯電体表面をクリーニング部材でクリーニングするクリーニング工程と、トナー画像を加熱定着する定着工程を含む画像形成方法において、該トナーが前記第（１）項乃至第（４）項のいずれかに記載の二成分現像用トナーであることを特徴とする画像形成方法」、
（１０）「該定着工程が、前記転写体から転写されたトナー像を担持した支持体を、一対のローラの間を通過させることによってトナー像の加熱定着を行う定着装置を用いるものであり、前記トナー像支持体のトナー像支持面と接触する側の定着ローラの肉厚が１．０ｍｍ以下、該一対のローラ間に加える面圧（ローラ荷重／接触面積）が１．５×１０⁵Ｐａ以下であることを特徴とする前記第（９）項に記載の画像形成方法」、
（１１）「トナー像が転写体上に転写された後の前記被帯電体の表面をクリーニングして該被帯電体表面上のトナーを回収し、回収したトナーを該現像手段に供給して現像工程に使用するリサイクルシステムを含む前記第（９）項または前記第（１０）項に記載の画像形成方法」、
（１２）「該帯電工程が、前記帯電部材を被帯電体に接触させて外部より帯電部材に電圧を印加し、被帯電体を帯電するものであることを特徴とする前記第（９）項乃至第（１１）項の何れかに記載の画像形成方法」、
（１３）「前記被帯電体が静電潜像担持体であり、該静電潜像担持体上の静電潜像を現像剤により現像し、前記転写手段を介して該現像画像を前記転写部材へ静電転写する工程の際に、該静電潜像担持体と転写手段とが当接することを特徴とする前記第（９）項乃至第（１２）項の何れかに記載の画像形成方法」により達成される。
また、本発明は（１４）「前記第（１）項乃至第（４）項の何れかに記載のトナーが充填されたことを特徴とするトナー容器」により達成される。
また、本発明は（１５）「前記第（１）項乃至第（４）項の何れかに記載のトナー及びキャリアを含有してなることを特徴とする二成分現像剤」により達成される。
また、本発明は（１６）「前記被帯電体としての感光体と、帯電手段、現像手段、クリーニング手段より選ばれる少なくとも一つの手段を一体に支持し、画像形成装置本体に着脱自在であるプロセスカ−トリッジにおいて、前記現像手段は、トナー（現像剤）を保持し、該トナー（現像剤）は、前記第（１）項乃至第（４）項のいずれかに記載のトナーを用いることを特徴とするプロセスカートリッジ」により達成される。

The method for producing a toner for developing an electrostatic charge image according to (5) above, which comprises a non-linear polyester resin synthesized using a compound represented by the formula (1) or an acid anhydride thereof: ,
(7) The electrostatic charge image according to (5) or (6), wherein the second additive is any one of hydrophobic silica, titanium oxide, alumina oxide, and zirconium oxide. Manufacturing method of developing toner ",
(8) “The mixing is performed using a mixing device having rotating blades, the peripheral speed of the rotating blades is 3 to 10 m / s in the first stage mixing, and the second stage mixing is 20 to 60 m / s. This is achieved by the method for producing a toner for developing an electrostatic charge image according to any one of items (5) to (7).
The present invention also provides: (9) “a charging step in which a voltage is applied to the charging member from the outside to charge the member to be charged, a step of forming an electrostatic charge image on the charged member to be charged, and an electrostatic charge image” A developing process for forming a toner image from the developing sleeve of the developing means, a transfer process using a transfer means for applying a voltage to the transfer member from the outside to transfer the toner image onto the transfer body, and the surface of the charged body after transfer In the image forming method including a cleaning step of cleaning the toner image with a cleaning member and a fixing step of heat-fixing the toner image, the toner is for two-component development according to any one of (1) to (4) An image forming method characterized by being a toner ",
(10) "The fixing step uses a fixing device that heat-fixes the toner image by passing a support carrying the toner image transferred from the transfer body between a pair of rollers, The thickness of the fixing roller on the side of the toner image support that contacts the toner image support surface is 1.0 mm or less, and the surface pressure (roller load / contact area) applied between the pair of rollers is 1.5 × 10 ⁵ Pa. The image forming method according to item (9), wherein:
(11) “After the toner image is transferred onto the transfer member, the surface of the member to be charged is cleaned to collect the toner on the surface of the member to be charged, and the recovered toner is supplied to the developing means for development. The image forming method according to (9) or (10), including a recycling system used in the process ”,
(12) The item (9), wherein the charging step comprises charging the charged body by bringing the charging member into contact with the charged body and applying a voltage to the charging member from the outside. Thru | or the image forming method in any one of (11) terms,
(13) “The charged body is an electrostatic latent image carrier, the electrostatic latent image on the electrostatic latent image carrier is developed with a developer, and the developed image is transferred to the transfer unit via the transfer unit. The image forming apparatus according to any one of (9) to (12), wherein the electrostatic latent image carrier and the transfer unit abut on each other during the step of electrostatic transfer to the member. Achieved by "method".
In addition, the present invention is achieved by (14) “a toner container that is filled with the toner according to any one of (1) to (4)”.
In addition, the present invention is achieved by (15) “two-component developer comprising the toner and the carrier according to any one of items (1) to (4)”.
According to the present invention, (16) “a process in which the photosensitive member as the member to be charged and at least one unit selected from a charging unit, a developing unit, and a cleaning unit are integrally supported and detachable from the main body of the image forming apparatus. In the cartridge, the developing means holds toner (developer), and the toner (developer) uses the toner described in any one of (1) to (4). This is achieved by a "characteristic process cartridge".

  As will be apparent from the following detailed and specific description, the toner of the present invention has an extremely excellent effect of being able to satisfy both high image quality and low-temperature fixability at the same time even during long-term use. .

In a toner having a small particle diameter, since the fluidity of the toner is deteriorated, it is necessary to add a large amount of hydrophobic silica which is a first additive and has a high fluidity-imparting effect. The BET specific surface area at this time is 80-200 m < ² > / g. If it is less than 80 m ² / g, the silica is agglomerated or has a large particle size, so that fluidity is not sufficiently imparted to the toner base particles, and if it exceeds 200 m ² / g, the fluidity is too high and the toner is too high. It becomes difficult to immobilize the base particles. However, when a high fluidity-imparting effect and an additive having a low fluidity-giving effect are added to the toner base particles at the same time and mixed, only the high fluidity has high agitation, Those having low fluidity are not sufficiently stirred and mixed and dispersed in an aggregated state. For this reason, it has been found that liberation from the surface of the toner base occurs during long-term use, which causes image unevenness, white stripes, and the like. In order to uniformly mix a plurality of additives having different fluidity and to fix it appropriately on the surface of the toner base, the BET specific surface area that is the first additive and has the highest fluidity-imparting effect is 80 to 200 m. Before mixing the hydrophobic silica in the range of ² / g, 50 to 100% of all the added parts by weight of the other additives are first added and mixed by a mixer (first stage mixing), then It was found that it is effective to add a step (second stage mixing) of adding the remaining total amount of the second additive and the total amount of the first additive and mixing them with a mixer. The second additive has a smaller BET specific surface area than the first additive, and thus has high cohesion, but powder torque with the toner base surface is applied by the first stage mixing (force is applied to the powder with mixing). Crush and homogenize. When mixing in the first stage, it is effective to add 50 to 100% of the total amount by weight of the second additive, and the fluidity and charge amount of the toner change depending on this ratio. Just decide. If it is less than 50% of the total weight part, the crushing effect at the first stage mixing is insufficient. Since the second additive is made uniform by the first stage mixing and the fluidity of the toner is improved, the remaining amount of the second additive and the entire first additive are added and mixed in the second stage mixing. As a result, uniform fixation on the surface of the toner base proceeds, and a toner free from the surface of the toner base can be obtained in long-term use.

  Examples of the mixing device at this time include a V-type mixer, a rocking mixer, a Ladige mixer, a Nauter mixer, a Henschel mixer, etc. In the mixing device having rotating blades, the peripheral speed of the rotating blades is In the first stage mixing, the speed is 3 to 10 m / s, and the second stage mixing is 20 to 40 m / s, so that the most effective crushing, homogenization in the first stage mixing, and the toner base in the second stage mixing. Uniform fixation proceeds. The lower speed of the first-stage mixing is advantageous for pulverizing and homogenizing the additive because the powder torque is applied, and it is preferably a low speed of 3 to 10 m / s so as not to apply a load to the toner base. When it is less than 3 m / s, it is not mixed, and when it exceeds 10 m / s, crushing and homogenization are insufficient. The second stage mixing is 20-60 m / s. Increasing the peripheral speed is more advantageous as the fixing of the additive to the toner base advances and is generally advantageous. However, if it exceeds 40 m / s, a load is applied to the toner and the toner may be fused. It cannot be over 40m / s. However, in the toner of the present invention, the surface of the toner base is coated with the additive by the first stage mixing, so that the adhesion between the toner bases is reduced, and the surface hardness is high due to the adhesion of inorganic fine particles to the surface of the base. Therefore, even if it is increased to 60 m / s, there is no occurrence of aggregation due to fusion of the toner bases. Thereby, sufficient fixation of the additive to the toner base can be achieved.

  When the second additive is any one of hydrophobic silica, titanium oxide, alumina oxide, and zirconium oxide, charging environmental stability, cleaning property, and transfer property are enhanced.

  Further, since the binder resin contains a polyester resin, the low-frequency fixability of the toner is advantageous, and the sharpness of the image is thereby increased. In particular, the following formula (1)

で示される化合物またはその酸無水物を用いて合成されたポリエステル樹脂を含有することにより耐ホットオフセット性が向上し、これにより定着温度幅が広くなるとともに、トナーの粉砕性が向上するので小粒径トナーには有利である。

And a polyester resin synthesized using the acid anhydride thereof, the hot offset resistance is improved, thereby widening the fixing temperature range and improving the pulverization property of the toner. This is advantageous for diameter toners.

  The execution of the image forming method is not limited as long as it is an apparatus for forming an image by electrophotography. For example, a copying machine or a printer is conjugated.

An example of an image forming apparatus using the toner of the present invention as a developer will be described.
FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention. In the figure, reference numeral (100) is a copying apparatus main body, (200) is a paper feed table on which the copying apparatus is placed, (300) is a scanner mounted on the copying apparatus main body (100), and (400) is an automatic document feeder mounted thereon. (ADF).
The copying apparatus main body (100) includes four image forming means (18) including various means for performing an electrophotographic process such as charging, developing, and cleaning around a photosensitive member (40) as a latent image carrier. Two parallel tandem image forming apparatuses (20) are provided. Above the tandem image forming apparatus (20), there is provided an exposure apparatus (21) that exposes the photoreceptor (40) with laser light based on image information to form a latent image. An intermediate transfer belt (10) made of an endless belt member is provided at a position facing each photoconductor (40) of the tandem type image forming apparatus (20). Primary transfer means (62) for transferring the toner images of the respective colors formed on the photoconductor (40) to the intermediate transfer belt (10) at positions facing the photoconductor (40) via the intermediate transfer belt (10). ) Is arranged.

Further, below the intermediate transfer belt (10), a secondary transfer device (for transferring the toner images superimposed on the intermediate transfer belt (10) onto transfer paper conveyed from the paper feed table (200) in a batch. 22) is arranged. The secondary transfer device (22) is configured by spanning a secondary transfer belt (24), which is an endless belt, between two rollers (23), and a support roller (16) via an intermediate transfer belt (10). The toner image on the intermediate transfer belt (10) is transferred to the transfer paper. Next to the secondary transfer device (22), a fixing device (25) for fixing the image on the transfer paper is provided. The fixing device (25) is configured by pressing a pressure roller (27) against a fixing belt (26) which is an endless belt.
The secondary transfer device (22) described above also has a sheet transport function for transporting the transfer paper after image transfer to the fixing device (25). Of course, as the secondary transfer device (22), a transfer roller or a non-contact charger may be arranged. In such a case, it is difficult to provide this sheet conveying function together.
In the illustrated example, the transfer paper is inverted under the secondary transfer device (22) and the fixing device (25) so as to record images on both sides of the transfer paper in parallel with the tandem image forming device (20). An inverting device (28) is provided.

The developer containing the toner is used for the developing device (4) of the image forming means (18).
In the developing device (4), the developer carrying member carries and conveys the developer, and an alternating electric field is applied at a position facing the photoconductor (40) to develop the latent image on the photoconductor (40). By applying the alternating electric field, the developer is activated, the charge amount distribution of the toner can be narrowed, and the developability can be improved.

  Further, the developing device (4) can be a process cartridge that is integrally supported together with the photoreceptor (40) and is detachably formed on the image forming apparatus main body. In addition, the process cartridge may include a charging unit and a cleaning unit.

The operation of the image forming apparatus is as follows.
First, the document is set on the document table (30) of the automatic document feeder (400), or the document is opened on the contact glass (32) of the scanner (300) by opening the automatic document feeder (400). Then, the automatic document feeder (400) is closed and pressed by it.
When a start switch (not shown) is pressed, when the document is set on the automatic document feeder (400), the document is transported and moved onto the contact glass (32), and then the other contact glass (32). When the document is set on the scanner, the scanner (300) is immediately driven to travel on the first traveling body (33) and the second traveling body (34). Then, the first traveling body (33) emits light from the light source, and the reflected light from the document surface is further reflected toward the second traveling body (34) and reflected by the mirror of the second traveling body (34). Then, the image is placed in the reading sensor (36) through the imaging lens (35), and the content of the original is read.

  When a start switch (not shown) is pressed, one of the support rollers (14), (15), and (16) is driven to rotate by the drive motor (not shown), and the other two support rollers are driven to rotate. The transfer belt (10) is rotated and conveyed. At the same time, the individual image forming means (18) rotates the photoreceptor (40) to form monochrome images of black, yellow, magenta, and cyan on each photoreceptor (40). Then, along with the conveyance of the intermediate transfer belt (10), these monochrome images are sequentially transferred to form a composite color image on the intermediate transfer belt (10).

On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers (42) of the paper feed table (200) is selectively rotated, and one of paper feed cassettes (44) provided in multiple stages in the paper bank (43). The sheet is fed out from the sheet, separated one by one by a separation roller (45), put into a sheet feeding path (46), and conveyed by a conveying roller (47) to a sheet feeding path (48) in the copying machine main body (100). Guide and stop against the registration roller (49).
Alternatively, the sheet feeding roller (50) is rotated to feed out the sheets on the manual feed tray (51), separated one by one by the separation roller (52), and placed in the manual sheet feeding path (53). ) And stop.
Then, the registration roller (49) is rotated in synchronization with the composite color image on the intermediate transfer belt (10), and the sheet is fed between the intermediate transfer belt (10) and the secondary transfer device (22). The image is transferred by the next transfer device (22) and a color image is recorded on the sheet.

The sheet after the image transfer is conveyed by the secondary transfer device (22) and sent to the fixing device (25). The fixing device (25) applies heat and pressure to fix the transferred image, and then the switching claw. It is switched at (55), discharged by the discharge roller (56), and stacked on the discharge tray (57). Alternatively, it is switched by the switching claw (55) and put into the sheet reversing device (28), where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then the paper discharge tray (56) is discharged by the discharge roller (56). 57) Drain up.
On the other hand, the intermediate transfer belt (10) after the image transfer is removed by the intermediate transfer belt cleaning device (17) to remove residual toner remaining on the intermediate transfer belt (10) after the image transfer, and the tandem image forming device (20). To prepare for image formation again.

FIG. 2 shows an example of a fixing device in the image forming technique of the present invention.
As described above, the image forming method of the present invention “uses a fixing device in which the fixing step heat-fixes the toner image by passing a support carrying the toner image between two rollers”. In addition, “the thickness of the fixing roller on the side in contact with the toner image support surface is 1.0 mm or less, and the surface pressure applied between the two rollers (roller load / contact area)” is also included. The use of a fixing device (fixing means) having an A of 1.5 × 10 ⁵ Pa or less ”is included as one feature. An example of this fixing device is shown in FIG. In the figure, (1) represents a fixing roller, and (2) represents a pressure roller. The fixing roller (1) is made of RTV (vulcanized rubber at room temperature), silicon rubber, tetrafluoroethylene-par on the surface of a metal cylinder (3) made of a high thermal conductor such as aluminum, iron, stainless steel or brass. An offset prevention layer (4) such as fluoroalkyl vinyl ether (PFA) or polytetrafluoroethylene (PTFE) is coated. A heating lamp (5) is arranged inside the fixing roller (1). The metal cylinder (6) of the pressure roller (2) is often made of the same material as the fixing roller (1), and its surface is covered with an offset prevention layer (7) such as PFA or PTFA. Although not necessarily required, a heating lamp (8) is disposed inside the pressure roller (2).
Although not shown, the fixing roller (1) and the pressure roller (2) are pressed against and rotated by springs at both ends.
A fixing support (S) (transfer paper such as paper) for toner image (T) is passed between the fixing roller (1) and the pressure roller (2) for fixing. As shown in the figure, it is preferable to pass the paper with the toner adhesion surface facing the fixing roller (1).

The fixing device used in the present invention improves the temperature rise characteristic of the fixing roller by setting the thickness of the metal cylinder of the fixing roller to 1.0 mm or less, and rises to a desired temperature in a very short time. be able to.
The preferred thickness of the metal cylinder varies depending on the strength and thermal conductivity of the material used, but is preferably 0.2 to 0.7 mm.
Further, the load (surface pressure) applied between the fixing roller and the pressure roller is preferably 1.5 × 10 ⁵ Pa or less. The surface pressure is a value obtained by dividing the load applied to both ends of the roller by the roller contact area.
The roller contact area is determined by passing a sheet whose surface property greatly changes due to heating, such as OHP paper, between the rollers heated to the fixing temperature, stopping on the way, holding it for several tens of seconds, and then discharging it. Find the area of the location.
A higher roller surface pressure is advantageous for fixing a toner image. However, in the fixing device in which the thickness of the metal cylinder of the fixing roller is 1.0 mm or less, a large load is not applied because the roller is distorted. The load is 1.5 × 10 ⁵ Pa or less, preferably 0.5 to 1.0 × 10 ⁵ Pa.
Since the toner of the present invention has a small particle size and a narrow particle size distribution, the thermal conductivity is good, and the roller surface pressure is 1.5 × 10 ⁵ Pa or less, preferably 0.5 to 1.0 × 10 ⁵ Pa. Even if it exists, favorable fixability is obtained.

The toner of the present invention is particularly useful in an image forming method having a recycling system. Since the release of additives is suppressed over a long period of time, the generation rate of recycled toner is suppressed in the first place due to the low generation rate of the reverse charge amount toner, and the contamination of the carrier and developing sleeve due to the released additive is also suppressed. Therefore, the development capacity does not deteriorate, and the amount of recycled toner generated is small. Furthermore, even in the case of recycled toner, since the additive is fixed, the decrease in fluidity and the generation of aggregates are suppressed, and abnormal images such as granular background stains are not generated.
In addition, since the additive of the toner of the present invention is uniformly fixed on the toner surface, the cohesiveness between the toners is low, so that the toner adheres to and melts on the charging member or the transfer member in the contact charging method or the contact transfer method. Good image quality can be provided without wearing.

  As the resin used in the toner of the present invention, conventionally known resins are used. For example, styrene, poly-α-still styrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene -Styrene such as maleic acid copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloroacrylic acid methyl copolymer, styrene-acrylonitrile-acrylic acid ester copolymer Resin (monopolymer or copolymer containing styrene or styrene-substituted product), polyester resin, epoxy resin, vinyl chloride resin, rosin-modified maleic acid resin, phenol resin, polyethylene resin, polypropylene resin, petroleum resin, polyurethane resin, Ketone resin, ethylene-ethylene Examples thereof include a acrylate copolymer, a xylene resin, and a polyvinyl butyrate resin, and it is particularly preferable to use a polyester resin from the viewpoint of fixing characteristics.

Further, in order to obtain a toner having a small particle diameter and a narrow distribution in the present invention without deteriorating the fixing characteristics, the pulverizability is improved by containing 5-30% of styrene acrylic resin or hybrid resin. As the hybrid resin, since the condensation polymerization resin and the addition polymerization resin are chemically bonded, it is preferable to perform polymerization using a compound that can react with any of the monomers of both resins. Examples of such a bireactive monomer include compounds such as fumaric acid, acrylic acid, methacrylic acid, maleic acid, and dimethyl fumarate.
The amount of both reactive monomers used is 1 to 25 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of the raw material monomer for the addition polymerization resin. When the amount was less than 1 part by weight, the colorant and the charge control agent were poorly dispersed and the image quality such as fog was deteriorated. When the amount is more than 25 parts by weight, there is a problem that the resin is gelled.

The hybrid resin as described above does not need to proceed and complete both reactions at the same time, and can select each reaction temperature and time to complete the reaction independently.
For example, a mixture of a vinyl resin addition polymerization raw material monomer and a polymerization initiator is added dropwise to a mixture of polyester resin polycondensation raw material monomers in a reaction vessel and mixed in advance. There is a method in which a polymerization reaction comprising a polyester resin is completed by a condensation polymerization reaction by completing the polymerization reaction comprising, and then raising the reaction temperature. By this method, it is possible to effectively disperse the two kinds of resins by allowing two independent reactions to proceed in parallel in the reaction vessel. In this case, the acid value of the hybrid resin is preferably 15 to 70 mgKOH / g, preferably 20 to 50 mgKOH / g, more preferably 20 to 30 mgKOH / g, and the acid value is 15 to 70 mgKOH / g. Furthermore, the effect of dispersing the release agent was high, and the low-temperature fixability and environmental stability were excellent. It is thought that by increasing the acid value, the compatibility between the paper and the resin is improved, and further low-temperature fixing is achieved. When the acid value is less than 15 mgKOH / g, the release agent contained and dispersed in the hybrid resin is easily released from the polyester. When the acid value exceeds 70 mgKOH / g, the influence of the moisture in the air increases, and the toner charge amount is inadequate. It becomes stable.

  Examples of the divalent acid component constituting the polyester resin that is preferably used in the present invention include, for example, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, diphenyl-P · P′-dicarboxylic acid, naphthalene- 2,7-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, diphenylmethane-P, P'-dicarboxylic acid, benzophenone-4,4'-dicarboxylic acid, 1,2-diphenoxyethane-P, P'-dicarboxylic Acids can be used, and other acids include maleic acid, fumaric acid, glutaric acid, cyclohexanedicarboxylic acid, succinic acid, malonic acid, adipic acid, mesaconic acid, itaconic acid, citraconic acid, sebacic acid, Anhydrides and lower alkyl esters can be used. Examples of the divalent alcohol include polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane, Examples include polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene (13) -2,2-bis (4-hydroxyphenyl) propane.

  Examples of other divalent alcohols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, and 1,4-butenediol. And diols such as 1,4-bis (hydroxymethyl) cyclohexane, bisphenol A, and hydrogenated bisphenol A.

で示される化合物またはその酸無水物の具体的な化合物としてはトリメリット酸、１，２，４−トリカルボン酸トリｎ−エチル、１，２，４−トリカルボン酸トリｎ−ブチル、１，２，４−トリカルボン酸トリｎ−ヘキシル、１，２，４−ベンゼントリカルボン酸トリイソブチル、１，２，４−ベンゼントリカルボン酸トリｎ−オクチル、１，２，４−ベンゼントリカルボン酸トリ２−エチルヘキシルが使用できる。但し何らこれに制限されるものではない。本発明のポリエステル樹脂においては、例えばｎ−ドデセニル基、イソドデセニル基、ｎ−ドデシル基、イソドデシル基、イソオクチル基、を有したマレイン酸、フマル酸、グルタル酸、コハク酸、マロン酸、アジピン酸の如きアルキルもしくはアルケニル置換基を有する酸及び／又は、エチレングリコール、１，３−プロピレンジオール、テトラメチレングリコール、１，４−ブチレンジオール、１，５−ペンチルジオールの如きアルコールを含んでいても良い。

Specific examples of the compound represented by the above formula or an acid anhydride thereof include trimellitic acid, tri-n-ethyl 1,2,4-tricarboxylate, tri-n-butyl 1,2,4-tricarboxylate, 1,2, Uses tri-n-hexyl 4-tricarboxylate, triisobutyl 1,2,4-benzenetricarboxylate, tri-n-octyl 1,2,4-benzenetricarboxylate, tri-2-ethylhexyl 1,2,4-benzenetricarboxylate it can. However, it is not limited to this. In the polyester resin of the present invention, for example, maleic acid, fumaric acid, glutaric acid, succinic acid, malonic acid, adipic acid having n-dodecenyl group, isododecenyl group, n-dodecyl group, isododecyl group, isooctyl group, etc. An acid having an alkyl or alkenyl substituent and / or an alcohol such as ethylene glycol, 1,3-propylene diol, tetramethylene glycol, 1,4-butylene diol, or 1,5-pentyl diol may be included.

  In addition, as a carrier to be used as a two-component developer by mixing the toner of the present invention, a powder having a particle size of about 30 to 1000 μm mainly composed of glass, iron, ferrite, nickel, zircon, silica, or the like, or The powder can be appropriately selected from those coated with a styrene-acrylic resin, a silicon resin, a polyamide resin, a polyvinylidene fluoride resin, etc. as a core material. 80 μm is preferable.

  In the toner of the present invention, polarity control can be blended in order to control polarity. Examples of the polarity control agent in this case include nigrosine dyes, quaternary ammonium salts, amino group-containing polymers, metal-containing azo dyes, salicylic acid complex compounds, and phenol compounds.

  As the release agent used in the toner of the present invention, known ones can be used, and in particular, the effect of dispersing the hybrid resin can be obtained by using a liberated fatty acid type carnauba wax, montan wax, and oxidized rice wax alone or in combination. Will increase. The carnauba wax is preferably a microcrystalline one, having an acid value of 5 or less and a particle size of 1 μm or less when dispersed in a toner binder. The montan wax generally refers to a montan wax refined from minerals, and like a carnauba wax, it is microcrystalline and preferably has an acid value of 5 to 14. The oxidized rice wax is obtained by air-oxidizing rice bran wax, and the acid value thereof is preferably 10-30. As other mold release agents, any conventionally known mold release agents such as solid silicone varnish, higher fatty acid higher alcohol, montan ester wax, and low molecular weight polypropylene wax can be mixed and used. The volume average particle size of the release agent before being dispersed in the toner binder is preferably 10 to 800 μm.

(Method for producing toner base particles)
The production method of the present invention includes a step of mechanically mixing developer components including at least a binder resin, a main charge control agent, and a pigment, a step of melt-kneading, a step of pulverizing, and a step of classifying. A toner manufacturing method can be applied. In addition, in the mechanical mixing step and the melt-kneading step, a production method is also included in which powder other than the particles obtained as a product obtained in the pulverization or classification step is returned and reused.
The powders (sub-products) other than the particles used as the product referred to here are fine particles and coarse particles other than the components used as the product having a desired particle size obtained in the pulverization step after the melt-kneading step, and a subsequent classification step. It means fine particles or coarse particles other than the components that are produced as products having a desired particle size. It is preferable that such a by-product is mixed in the weight ratio of the other raw material 50 to the raw material and preferably from the other raw material 99 to the sub-product 50 in the mixing step or the melt-kneading step.
The mixing step of mechanically mixing at least a binder resin, a main charge control agent and a pigment, and a developer component including a by-product may be performed under normal conditions using a normal mixer with a rotating wing, There is no particular limitation.
When the above mixing process is completed, the mixture is then charged into a kneader and melt-kneaded. As the melt kneader, a uniaxial or biaxial continuous kneader or a batch kneader using a roll mill can be used.
It is important that this melt-kneading is performed under appropriate conditions that do not cause the molecular chains of the binder resin to be broken. Specifically, the melt kneading temperature should be performed with reference to the softening point of the binder resin. If the temperature is too low than the softening point, cutting is severe, and if the temperature is too high, dispersion does not proceed.
When the above melt-kneading process is completed, the kneaded product is then pulverized. In this pulverization step, it is preferable to first coarsely pulverize and then finely pulverize. At this time, a method of pulverizing by colliding with a collision plate in a jet stream or pulverizing with a narrow gap between a rotor and a stator that rotate mechanically is preferably used.
After the pulverization step is completed, the pulverized product is classified in an air stream by centrifugal force or the like, thereby producing toner base particles having a predetermined particle size.

[Measurement of THF-insoluble matter]
1.0 g of sample is weighed (W5 g), cylindrical filter paper (for example, No. 86R manufactured by Toyo Roshi Kaisha Co., Ltd.) is put in, subjected to a Soxhlet extractor, extracted for 10 hours using 200 ml of THF as a solvent, and soluble components extracted by the solvent After evaporation of the solution, it is vacuum-dried at 100 ° C. for several hours, and the amount of THF-soluble resin component is weighed (W6 g). The THF-insoluble content of the binder resin can be obtained from the following formula.
In the present invention, the molecular weight distribution of a chromatogram by GPC (gel permeation chromatography) using THF as the solvent for the resin component tetrahydrofuran (THF) is measured under the following conditions.

The measurement sample is prepared as follows.
The sample and THF are mixed at a concentration of about 0.5 to 5 mg / ml (for example, about 5 mg / ml) and left at room temperature for several hours (for example, 5 to 6 hours). Are mixed well (until the sample is no longer united), and then allowed to stand at room temperature for 12 hours or longer (for example, 24 hours). At this time, the time from the start of mixing the sample and THF to the end of standing is set to 24 hours or longer. Then, GPC was passed through a sample processing filter (pore size 0.45 to 0.5 μm, for example, Mysori Disc H-25-2 manufactured by Tosoh Corp., Excro Disc 25CR manufactured by Gelman Science Japan Co., Ltd.). This sample. The sample concentration is adjusted so that the resin component is 0.5 to 5 mg / ml.

In the GPC measurement apparatus, the column is stabilized in a heat chamber at 40 ° C., THF is flowed through the column at this temperature as a solvent at a flow rate of 1 ml / min, and about 100 μl of the THF sample solution is injected and measured. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, for example, one having a molecular weight of about 10 ² to 10 ⁷ manufactured by Tosoh Corporation or Showa Denko is used, and at least about 10 standard polystyrene samples are suitably used. . An RI (refractive index) detector is used as the detector. As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, a combination of shodex GPC KF-801, 802, 803, 804, 805, 806, 807, 800P manufactured by Showa Denko, A combination of TSKgel G1000H (HXL), G2000H (HXL), G3000H (HXL), G4000H (HXL), G5000H (HXL), G6000H (HXL), G7000H (HXL), and TSKguardcolumn can be given.
In general, in the measurement of the GPC chromatogram, the high molecular weight side starts from the baseline when the chromatogram rises, and the low molecular weight side measures up to a molecular weight of about 400.

Volume average particle size (Dv), number average particle size (Dn), particle size distribution index (Dv / Dn) calculation method As a measuring device for particle size distribution of toner particles by the Coulter counter method, Coulter counter TA-II or Coulter multisizer II (both manufactured by Coulter). The measurement method is described below.
First, 0.1 to 5 ml of a surfactant (preferably polyoxyethylene alkyl ether) is added as a dispersant to 100 to 150 ml of an aqueous electrolytic solution. Here, the electrolytic solution is a solution prepared by preparing a 1% NaCl aqueous solution using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the measurement device is used to measure the volume and number of toner particles or toner using a 100 μm aperture as an aperture Volume distribution and number distribution are calculated. From the obtained distribution, the weight average particle diameter (D4) and the number average particle diameter of the toner can be obtained.

  As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm. From this, a volume average particle size (Dv), a number average particle size (Dn), and a particle size distribution index (Dv / Dn) are calculated.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these Examples. In the following, “parts” represents mass% unless otherwise specified.

(Synthesis example of polyester resin used in Examples 1 to 3)
Polyester resin (1)
In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen introducing tank, 3 mol of trimethylolpropane, 1 mol of fumaric acid, 1 mol of isophthalic acid, and 0.2 mol of tin (II) octylate were added, and a nitrogen stream at 230 ° C. The reaction was carried out for 2 hours while distilling off the water produced below. Next, 0.5 mol of trimellitic anhydride (reacted for 1 hour under reduced pressure of 5 to 20 mmHg) was added, the reaction was taken out for 2 hours under sealed at normal pressure, taken out, cooled to room temperature, pulverized, and nonlinear polyester resin (1) Got.
Resin (1) contained 20% of THF-insoluble matter, and the peak top molecular weight was 8,200.

Polyester resin (2)
In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen inlet, 1 mol of propylene oxide adduct of bisphenol A, 1 mol of ethylene oxide adduct of bisphenol A, 1.5 mol of adipic acid, cyclohexanedicarboxylic acid 0. 5 mol and 1 mol of tin (II) dilaurate were added and reacted at 230 ° C. for 2 hours while distilling off the water produced under a nitrogen stream. Next, the mixture was reacted for 3 hours under reduced pressure of 5 to 20 mmHg, cooled to room temperature, and then pulverized to obtain a linear polyester resin (2).
Resin (2) contained no THF-insoluble matter and had a peak top molecular weight of 4,500.

Polyester resin (3)
1 mol (455 g) of phenol novolak resin A having a nucleus number of 4.4 (average number of phenol nuclei in one molecule) and a softening point of 81 ° C. was placed in the autoclave, and the air in the reaction vessel was replaced with nitrogen. . Next, 1 mol of titanium dihydroxybistriethanolaminate was added, and 3 mol of ethylene glycol was gradually injected while maintaining the temperature at 120 ° C. to complete the reaction. Volatile substances were removed to obtain an oxyalkylene ether (NE1) of a novolac type phenol resin. 2.1 mol (735 g) of polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) in a reaction vessel equipped with a thermometer, a stirrer equipped with a torque detector, a cooler and a nitrogen introduction tube ), NE1 (0.9 mol) and terephthalic acid (3 mol) were added and reacted at 230 ° C. under a nitrogen stream. The reaction temperature was lowered to 200 ° C. from the time when the reaction product became transparent, and the polyesterification reaction proceeded under reduced pressure. The reaction was stopped when the viscosity of the reaction product gradually increased and the torque of the stirring rod showed a predetermined value, and the reaction product was taken out and rapidly cooled to obtain the polyester resin ((3)) of the present invention. Polyester resin (3) had a THF insoluble content of 28% and a peak top molecular weight of 5200.

Hybrid resin (4)
20 mol of styrene as an addition polymerization monomer, 5 mol of n-butyl methacrylate, and 1 mol of t-butyl hydroperoxide as a polymerization initiator are placed in a dropping funnel, phthalic acid: 30 mol as an addition polymerization and polycondensation reactive monomer, and as a condensation polymerization reaction monomer. Trimellitic anhydride: 10 mol, bisphenol A (2,2) propylene oxide: 10 mol, bisphenol A (2,2) ethylene oxide: 10 mol, 8 mol of distearoxytin (II) as an esterification catalyst, stainless steel stirring rod, flow-down type The mixture was placed in a flask equipped with a condenser, a nitrogen gas inlet tube and a thermometer, and a mixture prepared by previously adding an addition polymerization material from a dropping funnel was added dropwise over 5 hours while stirring at 150 ° C. in a nitrogen atmosphere. After completion, the mixture was aged for 5 hours while maintaining at 150 ° C., and then reacted by raising the temperature to 230 ° C. to obtain a hybrid resin (4).
The hybrid resin (4) contained no THF-insoluble matter and had a peak top molecular weight of 9,500.

Styrene acrylic resin (5)
A flask equipped with a cooling tube, a stirrer, a gas introduction tube and a thermometer, 2000 g of ion exchange water, 500 g of styrene as a monomer, 100 g of glycidyl acrylate, 50 g of benzoyl peroxide as a radical initiator, and dodecenyl as a dispersant Charge 10 g of sodium benzenesulfonate. The mixture was heated while stirring with nitrogen substitution, heated to 90 ° C., and reacted for 12 hours. The obtained polymer was washed with water and dried at a room temperature of 10 torr to obtain a powdery powder having a volatile content of 1% or less.
Styrene acrylic resin (5) contained no THF-insoluble matter and had a peak top molecular weight of 4000.

Toner base particle TB1 preparation method Polyester resin (1) 50 parts Polyester resin (2) 30 parts Orient Chemical Co., Ltd. E-84 (zinc salicylate (III) complex) 5 parts Carnauba wax (acid value: 5 mg KOH / g, Mw: 1600) 5 parts carbon black (REGAL330R Cabot) 10 parts After pre-mixing the materials with the above formulation using a Henschel mixer [FM10B made by Mitsui Miike Chemicals Co., Ltd.], a biaxial kneader [made by Ikegai Co., Ltd.] PCM-30]. Then, after finely pulverizing using a supersonic jet pulverizer, Labo Jet [manufactured by Nippon Pneumatic Industry Co., Ltd.], it is classified by an airflow classifier [MDS-I manufactured by Nippon Pneumatic Industry Co., Ltd.] and the number average particle diameter ( Toner base particles TB1 having a Dn) of 4.0 μm and a particle size distribution index (Dv / Dn) of 1.3 were prepared.

Toner base particle TB2 production method Polyester resin (3) 80 parts Styrene acrylic resin (5) 10 parts Orient Chemical Industries, Ltd. X-11 (zirconium salicylate complex) 2 parts WEP-1 (Nippon Yushi Fatty Ester Wax) 8 parts Carbon black (REGAL330R Cabot Corp.) 10 parts After pre-mixing the material with the above formulation using a Henschel mixer [FM10B made by Mitsui Miike Chemical Co., Ltd.], kneading using a biaxial kneader [PCM-30 made by Ikegai Co., Ltd.] did. Then, after finely pulverizing using a supersonic jet pulverizer, Labo Jet [manufactured by Nippon Pneumatic Industry Co., Ltd.], it is classified by an airflow classifier [MDS-I manufactured by Nippon Pneumatic Industry Co., Ltd.] and the number average particle diameter ( Toner base particles TB2 having a Dn) of 4.5 μm and a particle size distribution index (Dv / Dn) of 1.0 were prepared.

Preparation method of toner base particle TB3 Polyester resin (1) 40 parts Polyester resin (2) 30 parts Hybrid resin (4) 10 parts X-11 (zirconium salicylate complex) manufactured by Orient Chemical Industry Co., Ltd. 2 parts WEP-5 (Ester made from NOF) Wax) 8 parts Carbon black (REGAL330R Cabot) 10 parts After pre-mixing the materials with the above formulation using a Henschel mixer [FM10B made by Mitsui Miike Kako Co., Ltd.], a biaxial kneader [made by Ikegai Co., Ltd.] PCM-30]. Then, after finely pulverizing using a supersonic jet pulverizer, Labo Jet [manufactured by Nippon Pneumatic Industry Co., Ltd.], it is classified by an airflow classifier [MDS-I manufactured by Nippon Pneumatic Industry Co., Ltd.] and the number average particle diameter ( Toner base particles TB3 having a Dn) of 2.5 μm and a particle size distribution index (Dv / Dn) of 1.2 were prepared.

Example 1
Mixed formulation Toner base particle TB1 100 parts Titanium dioxide T805 (Nippon Aerosil: BET specific surface area 50 m ² / g) 1.2 parts Hydrophobic silica R202 (Nippon Aerosil: BET specific surface area 80 m ² / g) 2.0 parts Additive mixing Use a 20L supermixer, flow cooling water, and mix 100 parts of toner base particle TB1 and 1.2 parts of titanium dioxide T805 as the first stage mixing, and mix for 2 minutes at a rotational speed of 8 m / s. did. Thereafter, 2.0 parts of hydrophobic silica R202 was added as the second-stage mixing, and mixed for 3 minutes at a rotational speed of 60 m / s to obtain the toner of Example 1.

Example 2
In Example 1, the toner of Example 2 was obtained by the same formulation and method as Example 1 except that the rotation speed of the first stage mixing was changed to 2 m / s.

Example 3
In Example 1, the toner of Example 3 was obtained by the same formulation and method as Example 1 except that the rotation speed of the first stage mixing was changed to 15 m / s.

Example 4
In Example 1, the toner of Example 4 was obtained by the same formulation and method as in Example 1 except that the rotation speed of the second stage mixing was changed to 18 m / s.

Example 5
In Example 1, the toner of Example 5 was obtained by the same formulation and method as in Example 1 except that the rotation speed of the second stage mixing was changed to 65 m / s.

Example 6
Mixed formulation Toner base particle TB1 100 parts Aluminum oxide C (Nippon Aerosil: BET specific surface area 100 m ² / g) 1.0 part Hydrophobic silica H3004 (Wacker: BET specific surface area 200 m ² / g) 1.5 parts Additive mixing Use a 20L supermixer, flow cooling water, and as the first stage mixing, add 100 parts of toner base particles TB1 and 0.8 part of aluminum oxide C, and mix for 2 minutes at a rotational speed of 3 m / s. did. Thereafter, 0.2 parts of aluminum oxide C and 1.5 parts of hydrophobic silica H3004 were added as the second stage mixing and mixed for 3 minutes at a rotational speed of 55 m / s to obtain the toner of Example 6.

Example 7
Mixed formulation Toner base particle TB2 100 parts Hydrophobic silica OX50 (Nippon Aerosil: BET specific surface area 60 m ² / g) 0.8 part Hydrophobic silica R972 (Nippon Aerosil: BET specific surface area 130 m ² / g) 2.5 parts Additive For mixing, a 20 L supermixer was used, cooling water was flowed, and 100 parts of toner base particle TB2 and 0.4 part of hydrophobic silica OX50 were added as the first stage mixing, and 2 at a rotational speed of 10 m / s. Mixed for minutes. Thereafter, 0.2 part of aluminum oxide C and 2.5 parts of hydrophobic silica R972 were added as the second stage mixing and mixed for 3 minutes at a rotational speed of 20 m / s to obtain the toner of Example 7.

Example 8
Mixed formulation Toner base particle TB3 100 parts Titanium dioxide P25 (Nippon Aerosil: BET specific surface area 40 m ² / g) 1.8 parts Hydrophobic silica R805 (Nippon Aerosil: BET specific surface area 160 m ² / g) 3.0 parts Additive mixing Use a 20L supermixer, flow cooling water, and mix 100 parts of toner base particle TB3 and 1.0 part of titanium dioxide P25 as the first stage mixing, and mix for 2 minutes at a rotational speed of 7 m / s. did. Thereafter, 0.8 parts of titanium dioxide P25 and 3.0 parts of hydrophobic silica R805 were added as the second stage mixing, and mixed for 3 minutes at a rotational speed of 40 m / s to obtain the toner of Example 8.

Comparative Example 1
Toner base particle TB1 100 parts Titanium dioxide T805 (Nippon Aerosil: BET specific surface area 50 m ² / g) 1.2 parts Hydrophobic silica R202 (Nippon Aerosil: BET specific surface area 80 m ² / g) 2.0 parts Additive mixing Using a 20 L super mixer, cooling water was poured, and the above formulation was added all at once and mixed for 3 minutes at a rotational speed of 60 m / s to obtain the toner of Comparative Example 1. The toner was partially fused around the rotation axis.

Toner base particle TB4, 5, preparation method Polyester resin (1) 50 parts Polyester resin (2) 30 parts Orient Chemical Co., Ltd. E-84 (zinc (III) salicylate complex) 5 parts Carnauba wax (acid value: 5 mg KOH / g, Mw: 1600) 5 parts Carbon black (REGAL330R Cabot) 10 parts After pre-mixing the materials with the above formulation using a Henschel mixer [FM10B, Mitsui Miike Chemical Co., Ltd.], then a twin screw kneader [Co., Ltd.] Kneaded with Ikegai PCM-30]. Then, after finely pulverizing using a supersonic jet pulverizer, Labo Jet [manufactured by Nippon Pneumatic Industry Co., Ltd.], it is classified by an airflow classifier [MDS-I manufactured by Nippon Pneumatic Industry Co., Ltd.] and the number average particle diameter ( Toner base particle TB4 having a Dn) of 5.0 μm and a particle size distribution index (Dv / Dn) of 1.1, a number average particle diameter (Dn) of 3.0 μm, and a particle size distribution index (Dv / Dn) of 1.5. Toner base particles TB5 were obtained.

Comparative Example 2
Mixed formulation Toner base particle TB4 100 parts Titanium dioxide P25 (Nippon Aerosil: BET specific surface area 50 m ² / g) 0.5 part Hydrophobic silica H30 (Wacker: BET specific surface area 280 m ² / g) 1.0 part Additive mixing Used a 20 L supermixer, poured cooling water, charged all at once according to the above formulation, and mixed for 3 minutes at a rotational speed of 40 m / s to obtain a toner of Comparative Example 2.

Comparative Example 3
Mixed formulation Toner base particle TB5 100 parts Titanium dioxide P25 (Nippon Aerosil: BET specific surface area 50 m ² / g) 0.5 part Hydrophobic silica H30 (Wacker: BET specific surface area 280 m ² / g) 1.0 part Additive mixing Used a 20 L supermixer, flowing cooling water, and as a first stage mixing, 100 parts of toner base particle TB5 and 0.1 part of titanium dioxide P25 were added and mixed at a rotational speed of 10 m / s for 2 minutes. . Thereafter, 0.4 part of titanium dioxide P25 and 1.0 part of hydrophobic silica H30 were added as the second stage mixing and mixed for 3 minutes at a rotational speed of 60 m / s to obtain a toner of Comparative Example 3.

Evaluation Methods of Examples 1 to 8 and Comparative Examples 1 to 3 Image Evaluation Method The obtained toner was put into Imagio neo453 manufactured by Ricoh, and evaluation was performed according to the following image evaluation method. This apparatus is a toner recycling system. The results are shown in Table 1.
The evaluation of image quality was performed after 100,000 sheets in a normal temperature / humidity environment (25 ° C., 60%).
Character sharpness: About 2 mm square “Den” characters were enlarged about 30 times and judged according to the evaluation criteria of FIG. Ranks 2 and 4 are intermediate levels of ranks 1, 3, 3 and 5, respectively.
Image density: The density of a solid black circle with a diameter of 3 cm was measured with a Macbeth densitometer at 10 points, and the average value was obtained.
Image density unevenness: The density of a solid solid circle with a diameter of 3 cm is measured at 10 points with a Macbeth densitometer, and the difference between the maximum value and the minimum value is obtained.
Cover A: No cover.
B: Slight fogging occurs but there is no practical problem.
C: Bad. It is terrible.

Fixing evaluation method Copying is performed by changing the heater temperature with a Ricoh Imagio neo 453 to obtain a fixed image. Evaluation was made by adjusting the thickness of the fixing roller to 0.5 mm and adjusting the surface pressure (roller load / contact area) applied between the two rollers to 1.0 × 10 ⁵ Pa.
A fixing tape (manufactured by 3M) is applied to the fixed image (toner adhesion amount: 0.85 ± 0.05 mg / cm ² ), and after applying a certain pressure (2 kg), it is slowly peeled off. The image density before and after that is measured with a Macbeth densitometer, and the fixing rate is calculated by the following equation. The temperature of the fixing roller is lowered step by step, and the temperature at which the fixing rate represented by the following formula becomes 80% or less is defined as the fixing temperature. (Image density = before tape attachment)

粉砕フィード：各トナーの粒度分布を得たときの粉砕フィード。

Grinding feed: Grinding feed when the particle size distribution of each toner is obtained.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention. 1 is a diagram illustrating an example of a fixing device used in the present invention. It is a figure showing the rank of the character sharpness used in the Example of this invention.

Explanation of symbols

(Figure 1)
4 Developing Device 10 Intermediate Transfer Belt 14 Support Roller 15 Support Roller 16 Support Roller 17 Intermediate Transfer Belt Cleaning Device 18 Image Forming Unit 20 Tandem Image Forming Device 21 Laser Exposure Device 22 Secondary Transfer Device 23 Roller 24 Endless Secondary Transfer Belt 25 Fixing device 26 Fixing belt 27 Pressure roller 25 Fixing device 28 Sheet reversing device 30 Document table 32 Contact glass 33 First traveling member 34 Second traveling member 35 Imaging lens 36 Reading sensor 40 Photosensitive member 42 Feeding roller 43 Paper bank 44 Paper feed cassette 45 Separator roller 46 Paper feed path 47 Transport roller 48 Paper feed path 49 Registration roller 50 Paper feed roller 51 Manual feed tray 52 Separation roller 53 Manual feed path 54 Registration roller 55 Switching claw 56 Ejection roller 57 Ejection tray 62 Primary Transfer means 100 Body,
200 Paper feed table 300 Scanner 400 Automatic document feeder (ADF)

(Figure 2)
DESCRIPTION OF SYMBOLS 1 Fixing roller 2 Pressure roller 3 Metal cylinder 4 Offset prevention layer 5 Heating lamp 6 Metal cylinder 7 Offset prevention layer 8 Heating lamp T Toner image S Adhesive support

Claims (16)

Electrostatic charge image development obtained by mixing toner base particles containing at least a colorant and a binder resin with two types of inorganic fine particles having different BET specific surface area values by a mixer using mechanical energy The first additive is a hydrophobic silica having a BET specific surface area of 80 to 200 m ² / g, and the second additive has a BET specific surface area smaller than that of the first additive. Has a number average particle diameter (Dn) of 2.5 μm to 4.5 μm, a particle size distribution index (Dv / Dn) of 1.0 to 1.3, and all of the toner base particles and the second additive Add 50 to 100% of the added weight part first and mix with a mixer (first stage mixing), then add the remaining amount of the second additive and the first additive all together and mix with the mixer To be obtained by the process (second stage mixing) The toner for developing electrostatic images which is characterized. The binder resin contains a polyester resin, and the polyester resin is represented by the following formula (1):

The toner for developing an electrostatic charge image according to claim 1, comprising a polyester resin synthesized using a compound represented by the formula (1) or an acid anhydride thereof. The electrostatic charge image developing toner according to claim 1, wherein the second additive is any one of hydrophobic silica, titanium oxide, alumina oxide, and zirconium oxide. The mixing is performed using a mixing device having rotating blades, and the peripheral speed of the rotating blades is 3 to 10 m / s in the first stage mixing and the second stage mixing is 20 to 60 m / s. 4. The electrostatic image developing toner according to claim 1, wherein the toner is for electrostatic image development. An electrostatic charge image toner is obtained by mixing two types of additives having different BET specific surface area values with a mixer using mechanical energy into a toner base particle containing at least a colorant and a binder resin. A method for producing a toner for image development, wherein the first additive is hydrophobic silica having a BET specific surface area of 80 to 200 m ² / g, and the second additive has a BET specific surface area larger than that of the first additive. The toner has a number average particle diameter (Dn) of 2.5 μm to 4.5 μm, a particle size distribution index (Dv / Dn) of 1.0 to 1.3, and the toner base particles and the second toner. First, add 50 to 100% of the total added weight part of the additive, and mix with a mixer (first stage mixing), and then add the remaining amount of the second additive and the total amount of the first additive. In addition, it includes a process of mixing with a mixer (second stage mixing) Method for producing a toner for developing electrostatic images. The binder resin contains a polyester resin, and the polyester resin is represented by the following formula (1):

6. The method for producing a toner for developing an electrostatic charge image according to claim 5, wherein the toner comprises a non-linear polyester resin synthesized using a compound represented by formula (1) or an acid anhydride thereof. 7. The method for producing a toner for developing an electrostatic charge image according to claim 5, wherein the second additive is any one of hydrophobic silica, titanium oxide, alumina oxide and zirconium oxide. The mixing is performed using a mixing apparatus having rotating blades, and the peripheral speed of the rotating blades is 3 to 10 m / s in the first stage mixing and the second stage mixing is 20 to 60 m / s. The method for producing a toner for developing an electrostatic charge image according to any one of claims 5 to 7. A charging step of applying a voltage to the charging member from the outside to charge the charged member, a step of forming an electrostatic charge image on the charged charged member, and a toner image from the developing sleeve of the developing means. A developing step for forming, a transfer step using a transfer means for applying a voltage to the transfer member from the outside and transferring the toner image onto the transfer member, a cleaning step for cleaning the surface of the charged member after transfer with a cleaning member, 5. An image forming method comprising a fixing step of heat-fixing a toner image, wherein the toner is the two-component developing toner according to any one of claims 1 to 4. The fixing step uses a fixing device that heats and fixes a toner image by passing a support carrying a toner image transferred from the transfer body between a pair of rollers. The thickness of the fixing roller on the side contacting the toner image support surface of the body is 1.0 mm or less, and the surface pressure (roller load / contact area) applied between the pair of rollers is 1.5 × 10 ⁵ Pa or less. The image forming method according to claim 9. After the toner image is transferred onto the transfer member, the surface of the member to be charged is cleaned to collect the toner on the surface of the member to be charged, and the collected toner is supplied to the developing means for use in the developing process. The image forming method according to claim 9 or 10, comprising a recycling system. 12. The charging process according to claim 9, wherein the charging step comprises charging the charged body by bringing the charging member into contact with the charged body and applying a voltage to the charging member from outside. Image forming method. The object to be charged is an electrostatic latent image carrier, the electrostatic latent image on the electrostatic latent image carrier is developed with a developer, and the developed image is electrostatically transferred to the transfer member via the transfer unit. 13. The image forming method according to claim 9, wherein the electrostatic latent image carrier and the transfer unit abut on each other during the transferring step. A toner container filled with the toner according to claim 1. A two-component developer comprising the toner and carrier according to any one of claims 1 to 4. In a process cartridge that integrally supports at least one member selected from a photosensitive member as a member to be charged and a charging unit, a developing unit, and a cleaning unit, and is detachable from an image forming apparatus main body, the developing unit includes: 5. A process cartridge that holds toner (developer) and uses the toner according to claim 1 as the toner (developer).

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