JP4136324B2 - Image forming method, image forming apparatus, and electrostatic image developing toner - Google Patents

Description

【表２】

【表３】

【表４】

【００８６】
【発明の効果】
以上、詳細かつ具体的な説明から明らかなように、本発明によれば、中間転写方式かつ接触（２次）転写方式を使用するフルカラー画像の形成において、イエロー、シアン、マゼンタ、ブラックである４色のトナーにおいてトナー帯電量を調整し、更に流動性付与剤の添加量、及びトナー帯電量を現像順に最適化することにより、転写チリ、転写抜け、転写ボソツキおよび地肌かぶりのない再現性の高い画像を形成しうる画像形成方法、画像形成装置及びそれに用いる静電荷像現像用トナーを提供することができる。
【図面の簡単な説明】
【図１】本発明のフルカラー画像形成装置の例の模式図である。
【図２】本発明のフルカラー画像形成装置の別の例の模式図である。
【符号の説明】
（図１）
１ａ〜１ｄ：現像器
２：感光体ドラム
３：中間転写ドラム
４：転写ローラ
５：定着ローラ
６：転写部材
（図２）
１ａ〜１ｄ：現像器
２：感光体ベルト
３：中間転写ベルト
４：転写ローラ
５：定着ローラ
６：転写部材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a full-color image forming method and an image forming apparatus using an electrophotographic system such as a printer and a copying machine, and a full-color toner used in the method, and more specifically, with an intermediate transfer member such as an intermediate transfer belt interposed, Image formation is performed through each transfer step of primary transfer in which a toner image is transferred from an electrostatic latent electrostatic latent image carrier to an intermediate transfer member and secondary transfer in which a primary transfer image on the intermediate transfer member is transferred to a transfer material. The present invention relates to an image forming method, an image forming apparatus, and an electrostatic image developing toner used in the image forming apparatus.
[0002]
[Prior art]
Conventionally, in color image forming apparatuses such as color printers and copiers that form a color image using an electrophotographic recording method, an electrostatic latent image is formed on the electrostatic latent image carrier for each color. A full-color toner image is formed by developing with color toner and electrostatically transferring the toner image on the latent electrostatic image bearing member onto a transfer member. For example, the first, second, third, and fourth color toner images formed on the electrostatic latent image carrier are sequentially transferred onto the intermediate transfer member (primary transfer), and the color toner is transferred to the intermediate transfer medium. An intermediate transfer method has been proposed in which, after an image is formed, the color toner image is collectively transferred (secondary transfer) to a recording support.
In the case of this intermediate transfer method, there are relatively many because it is easy to handle and control to prevent color misregistration, and it is easy to shorten the transfer part of the transfer member and simplify the transfer path. It has been adopted.
[0003]
However, in a color image forming apparatus using an intermediate transfer member, a pressing force is applied to the electrostatic latent image on the electrostatic latent image carrier when developing other colors, and the transfer process is further increased. A portion having a strong adhesive force is generated between the toner of the electrostatic latent image and the current electrostatic latent image carrier, and is difficult to be transferred, resulting in a problem that the image is lost (so-called transfer omission). Further, even if the transfer is not lost, uneven transfer efficiency occurs, resulting in uneven solid images. In particular, a full-color image is distorted and very unsightly (hereinafter referred to as transfer blur).
In recent years, full-color printers have become widespread, and image reproducibility has become increasingly important, and printers often use recording media with large surface irregularities, such as recycled paper and bond paper, and irregularly shaped paper. For this reason, there is a problem that the image must be transferred without causing image defects.
[0004]
Conventionally, in order to solve these problems, a means for adding a large amount of an external additive such as silica which is a fluidity imparting agent to lower the cohesive force of the toner and prevent transfer omission and transfer blur has been taken. However, when the amount of external additives such as silica is increased, the fluidity is improved to some extent with the amount added, but there is a limit. Also, silica suspended matter increases. For example, when using an intermediate transfer medium of a belt based on urethane, the silica released from the toner base is driven into the belt and scratches occur, or the silica adheres to the belt. Silica filming occurs.
Further, silica becomes a nucleus and is driven into the electrostatic latent image carrier by the pressing force of the cleaning blade, and scratches are generated. Filming in which silica or toner adheres on the electrostatic latent image carrier occurs. Silica suspended matter adheres to the solid image area and white spots are generated.
Further, in the color image forming method in which the overlapping transfer is performed, there is a problem that so-called transfer dust in which the toner scatters due to an increase in the amount of the additive causes reduction in resolution and deterioration in image quality.
[0005]
As a method for solving these problems, in Japanese Patent Laid-Open Nos. 7-181732 and 7-181733, the toner used in the intermediate transfer type image forming apparatus is formed into a spherical shape so that the transfer is lost during transfer. In addition, it is described that transfer blur and scattering are improved. However, although there was a slight improvement effect with respect to transfer omission, the effect was still insufficient, and there was almost no effect with respect to transfer dust. In particular, in the one-component development, there is a problem that by making the shape spherical, frictional charging between the blade and the blade becomes insufficient, and toner charging becomes unstable.
[0006]
Further, in the intermediate transfer system, these transfer omissions and transfer blurs are more likely to occur in the color with the earlier development order. That is, for example, the first, second, third, and fourth color toner images formed on the electrostatic latent image carrier are transferred to the intermediate transfer member, and the first, second, third, and fourth layers are transferred. When the toner layer of the first layer is formed in an overlapping manner, the first color toner on the intermediate transfer body overlaps the second and subsequent colors, regardless of whether or not the transfer is performed. If it is a color, it will pass 3 times. For this reason, when a transfer pressure is applied during the primary transfer process other than during image formation, the faster the development order, the stronger the cohesive force in the transfer toner layer, and the less transfer from the toner layer closest to the intermediate transfer body becomes. It is thought to be because.
[0007]
On the other hand, for transfer dust, if the cohesive force between the toners is relatively high and the fluidity is relatively small, the toner easily moves even with a slight repulsive force between the toners. The repulsive force due to the same polarity of the toner may act between the toner being transferred and the toner to be transferred next, and the toner is likely to be scattered.
In order to solve this problem, Japanese Patent No. 2680081 discloses that the transfer dust and transfer omission prevention can be solved by setting the order of the overlap transfer with toner in the order of the content of the fluidity improving additive. However, the transfer dust due to electrostatic repulsion is not sufficient, and in particular in a developing system in which a contact pressure such as a transfer roller is applied, transfer dust is not solved.
In order to reduce transfer dust, it may be possible to reduce the charge amount. However, if the charge amount of the toner is low and the toner of reverse polarity increases, the toner adheres to the background, and the output image on the transfer paper has a background. There is a problem that appears as a cover of the part. In particular, in the full-color development method in which the four-color development is performed, the fogging of the background portion becomes four times, so that it is easily noticeable. In addition, when the toner charge rises worse, there is a problem that the density stability is deteriorated, for example, a density difference occurs between the front and rear edges of the paper or a ghost appears.
[0008]
For these reasons, with regard to transfer dust, full color is reproduced with yellow, cyan, and magenta by image processing technology, and black is reproduced only with black. Although measures such as setting to reduce the amount of color overlap have been taken, it is still not sufficient. In addition, when creating a full color with four development colors of yellow, magenta, cyan, and black, it is easy to stand out in the order of black, magenta, cyan, and yellow, but black is less likely to overlap colors. When either or both of magenta and cyan are superposed, the transfer dust becomes very conspicuous, but when yellow is superposed later, the transfer dust is relatively inconspicuous and the image reproducibility is hardly affected.
[0009]
[Problems to be solved by the invention]
An object of the present invention is to solve the above-mentioned problems such as transfer omission and contact dust caused by toner in a full-color image forming method using an intermediate transfer system, and to achieve color balance without color unevenness and background fog. An object of the present invention is to provide an image forming method capable of obtaining excellent image quality.
Another object of the present invention is to solve the above-mentioned problems such as transfer omission and transfer dust caused by toner in an image forming apparatus of a full color image forming system using an intermediate transfer system, and color unevenness and background fogging. Another object of the present invention is to provide an image forming apparatus capable of obtaining high image quality with a good color balance.
A further object of the present invention is to provide an electrostatic charge image developing toner capable of solving the above-mentioned problems such as transfer omission and transfer dust caused by toner in toner used for image formation using an intermediate transfer method. Is to provide.
[0010]
[Means for Solving the Problems]
As a result of extensive research conducted by the present inventors, in order to output stable image quality characteristics free from transfer blur, transfer omission and transfer dust, the addition of a fluidity imparting agent for each color toner in intermediate transfer and contact transfer The inventors have found that the above object can be achieved by adjusting the amount and the toner charge amount, and further optimizing in the order of development, thereby completing the present invention.
That is, according to the present invention, yellow, cyan, magenta, and black are developed, and an electrostatic latent image is formed on the electrostatic latent image carrier for each, and developed with color toner. After the toner image on the electrostatic latent image carrier is primarily transferred to the intermediate transfer member, the toner images on the intermediate transfer member are collectively transferred to the transfer member and then transferred onto the transfer member. When fixing toner, full color reproduction is performed by superimposing three colors of yellow, cyan, and magenta, and only a black color is used in a full color image forming method.
(A) The full-color toner contains at least a binder resin, a colorant, and a fluidizing imparting agent. When the toner in the earlier development order of cyan and magenta is A, and the toner in the later development order is B, Addition amount of fluidizing agent is A> B,
(B) Absolute value of toner charge amount at this time | Q _A / M |, | Q _B / M | is | Q _A / M | >> Q _B / M |
(C) 15 μC / g <| Q _A / M | <40 μC / g,
(D) In secondary transfer, a transfer device to which a transfer bias is applied is brought into contact at 3 g / cm or more to transfer a toner image to a transfer member.
An image forming method is provided.
[0011]
In addition, according to the present invention, there are four color development sections of yellow, cyan, magenta, and black, and an electrostatic latent image is formed on the electrostatic latent image carrier for each, and this is developed with color toner. After the toner image on the electrostatic latent image carrier is primarily transferred to the intermediate transfer member, the toner image on the intermediate transfer member is secondarily transferred (collectively transferred) to the transfer member and then transferred onto the transfer member. In a full color image forming method for fixing the toner of
(A) The full-color toner contains at least a binder resin, a colorant, and a fluidizing imparting agent. A toner having the fastest developing order among cyan, magenta, and black is A, a second toner is B, and a developing order is the most. When the toner having a slower speed is C, the addition amount of the fluidizing agent is A>B> C,
(B) Absolute value of toner charge amount at this time | Q _A / M |, | Q _B / M |, | Q _C / M | is | Q _A / M | >> Q _B / M | >> Q _C / M |
(C) 15 μC / g <| Q _A / M | <40 μC / g,
(D) In secondary transfer, a transfer device to which a transfer bias is applied is brought into contact at 3 g / cm or more to transfer a toner image to a transfer member.
An image forming method is provided.
[0012]
In addition, according to the present invention, there are four color development sections of yellow, cyan, magenta, and black, and an electrostatic latent image is formed on the electrostatic latent image carrier for each, and this is developed with color toner. After the toner image on the electrostatic latent image carrier is primarily transferred to the intermediate transfer member, the toner image on the intermediate transfer member is secondarily transferred (collectively transferred) to the transfer member and then transferred onto the transfer member. In a full color image forming method for fixing the toner of
(A) The full-color toner contains at least a binder resin, a colorant, and a fluidizing imparting agent. A yellow toner, a cyan toner, a magenta toner, and a black toner having the fastest development order are A, a second toner is B, 3 When the second toner is C and the toner with the slowest development order is D, the addition amount of the fluidizing agent is A>B>C> D,
(B) Absolute value of toner charge amount at this time | Q _A / M |, | Q _B / M |, | Q _C / M |, | Q _D / M | is | Q _A / M | >> Q _B / M | >> Q _C / M | >> Q _D / M |
(C) 15 μC / g <| Q _A / M | <40 μC / g,
(D) In secondary transfer, a transfer device to which a transfer bias is applied is brought into contact at 3 g / cm or more to transfer a toner image to a transfer member.
An image forming method is provided.
[0013]
In addition, according to the present invention, there are four color development sections of yellow, cyan, magenta, and black, and an electrostatic latent image is formed on the electrostatic latent image carrier for each, and this is developed with color toner. After the toner image on the electrostatic latent image carrier is primarily transferred to the intermediate transfer member, the toner images on the intermediate transfer member are collectively transferred to the transfer member and then transferred onto the transfer member. When fixing toner, full color reproduction is performed by superimposing three colors of yellow, cyan and magenta, and only black is used in a single color.
(A) The full-color toner contains at least a binder resin, a colorant, and a fluidizing imparting agent. When the toner in the earlier development order of cyan and magenta is A, and the toner in the later development order is B, Addition amount of fluidizing agent is A> B,
(B) Absolute value of toner charge amount at this time | Q _A / M |, | Q _B / M | is | Q _A / M | >> Q _B / M |
(C) 15 μC / g <| Q _A / M | <40 μC / g,
(D) In secondary transfer, a transfer device to which a transfer bias is applied is brought into contact at 3 g / cm or more to transfer a toner image to a transfer member.
An image forming apparatus is provided.
[0014]
In addition, according to the present invention, there are four color development sections of yellow, cyan, magenta, and black, and an electrostatic latent image is formed on the electrostatic latent image carrier for each, and this is developed with color toner. After the toner image on the electrostatic latent image carrier is primarily transferred to the intermediate transfer member, the toner image on the intermediate transfer member is secondarily transferred (collectively transferred) to the transfer member and then transferred onto the transfer member. In a full-color image forming apparatus of a method for fixing toner of
(A) The full-color toner contains at least a binder resin, a colorant, and a fluidizing imparting agent. A toner having the fastest developing order among cyan, magenta, and black is A, a second toner is B, and a developing order is the most. When the toner having a slower speed is C, the addition amount of the fluidizing agent is A>B> C,
(B) Absolute value of toner charge amount at this time | Q _A / M |, | Q _B / M |, | Q _C / M | is | Q _A / M | >> Q _B / M | >> Q _C / M |
(C) 15 μC / g <| Q _A / M | <40 μC / g,
(D) In secondary transfer, a transfer device to which a transfer bias is applied is brought into contact at 3 g / cm or more to transfer a toner image to a transfer member.
An image forming apparatus is provided.
[0015]
In addition, according to the present invention, there are four color development sections of yellow, cyan, magenta, and black, and an electrostatic latent image is formed on the electrostatic latent image carrier for each, and this is developed with color toner. After the toner image on the electrostatic latent image carrier is primarily transferred to the intermediate transfer member, the toner image on the intermediate transfer member is secondarily transferred (collectively transferred) to the transfer member and then transferred onto the transfer member. In a full-color image forming apparatus of a method for fixing toner of
(A) The full-color toner contains at least a binder resin, a colorant, and a fluidizing imparting agent. A yellow toner, a cyan toner, a magenta toner, and a black toner having the fastest development order are A, a second toner is B, 3 When the second toner is C and the toner with the slowest development order is D, the addition amount of the fluidizing agent is A>B>C> D,
(B) Absolute value of toner charge amount at this time | Q _A / M |, | Q _B / M |, | Q _C / M |, | Q _D / M | is | Q _A / M | >> Q _B / M | >> Q _C / M | >> Q _D / M |
(C) 15 μC / g <| Q _A / M | <40 μC / g,
(D) In secondary transfer, a transfer device to which a transfer bias is applied is brought into contact at 3 g / cm or more to transfer a toner image to a transfer member.
An image forming apparatus is provided.
[0016]
In addition, according to the present invention, there are four color development sections of yellow, cyan, magenta, and black, and an electrostatic latent image is formed on the electrostatic latent image carrier for each, and this is developed with color toner. After the toner image on the electrostatic latent image carrier is primarily transferred to the intermediate transfer member, the toner images on the intermediate transfer member are collectively transferred to the transfer member and then transferred onto the transfer member. When fixing toner, full-color reproduction is performed by superimposing three colors of yellow, cyan, and magenta. Only black is used as a single color, and the secondary transfer makes contact with a transfer device to which a transfer bias is applied at 3 g / cm or more. A toner for use in full-color image formation in which a toner image is transferred to a transfer member,
(A) The full-color toner contains at least a binder resin, a colorant, and a fluidizing imparting agent. When the toner in the earlier development order of cyan and magenta is A, and the toner in the later development order is B, Addition amount of fluidizing agent is A> B,
(B) Absolute value of toner charge amount at this time | Q _A / M |, | Q _B / M | is | Q _A / M | >> Q _B / M |
(C) 15 μC / g <| Q _A / M | <40 μC / g
There is provided a toner for developing an electrostatic charge image.
[0017]
Furthermore, according to the present invention, there are four color development portions of yellow, cyan, magenta, and black, and an electrostatic latent image is formed on the electrostatic latent image carrier, and this is developed with color toner. After the toner image on the electrostatic latent image carrier is primarily transferred to the intermediate transfer member, the toner image on the intermediate transfer member is secondarily transferred (collectively transferred) to the transfer member and then transferred onto the transfer member. The secondary transfer is a toner used in full color image formation in which a transfer device to which a transfer bias is applied is brought into contact at 3 g / cm or more to transfer a toner image to a transfer member. ,
(A) The full-color toner contains at least a binder resin, a colorant, and a fluidizing imparting agent. A toner having the fastest developing order among cyan, magenta, and black is A, a second toner is B, and a developing order is the most. When the toner having a slower speed is C, the addition amount of the fluidizing agent is A>B> C,
(B) Absolute value of toner charge amount at this time | Q _A / M |, | Q _B / M |, | Q _C / M | is | Q _A / M | >> Q _B / M | >> Q _C / M |
(C) 15 μC / g <| Q _A / M | <40 μC / g
There is provided a toner for developing an electrostatic charge image.
[0018]
Furthermore, according to the present invention, there are four color development portions of yellow, cyan, magenta, and black, and an electrostatic latent image is formed on the electrostatic latent image carrier for each, and this is developed with color toner. The toner image on the electrostatic latent image carrier is subjected to primary transfer to the intermediate transfer member, and then the toner image on the intermediate transfer member is secondarily transferred (collectively transferred) to the transfer member. The upper toner is fixed, and the secondary transfer is a toner used in full color image formation in which a transfer device to which a transfer bias is applied is brought into contact at 3 g / cm or more to transfer a toner image to a transfer member. And
(A) The full-color toner contains at least a binder resin, a colorant, and a fluidizing imparting agent. A yellow toner, a cyan toner, a magenta toner, and a black toner having the fastest development order are A, a second toner is B, 3 When the second toner is C and the toner with the slowest development order is D, the addition amount of the fluidizing agent is A>B>C> D,
(B) Absolute value of toner charge amount at this time | Q _A / M |, | Q _B / M |, | Q _C / M |, | Q _D / M | is | Q _A / M | >> Q _B / M | >> Q _C / M | >> Q _D / M |
(C) 15 μC / g <| Q _A / M | <40 μC / g
There is provided a toner for developing an electrostatic charge image.
[0019]
When generating a full-color image, it is difficult to transfer the four-color toner images uniformly. Further, when an intermediate transfer member is used, problems are likely to occur in terms of color unevenness and color balance, and a high-quality full-color image is stabilized. Output is not easy.
For this reason, by adopting the configuration of the present invention, that is, when reproducing a full color image by color superposition, if the amount of the fluidizing agent is increased as the developing order is earlier, the transfer can be performed even in the primary transfer. Aggregation due to transfer pressure or other stress is less likely to occur, and in the case of layering on an intermediate transfer member, the layer closest to the intermediate transfer member (that is, the layer farthest from the transfer member in the case of secondary transfer) aggregates. Therefore, in the secondary transfer to which a transfer pressure and a transfer bias are applied, it is excellent in releasability from the intermediate transfer member, and transfer omission and transfer blur hardly occur.
[0020]
Further, the higher the charge in the developing order, the higher the charge, and the absolute value of the charge amount of the toner in the developing order that is the earliest in the overlapped image is adjusted to a range of 15 to 40 μC / g. Since the electrostatic repulsion is reduced and the later development during the primary transfer has a low charge, the electrostatic repulsion is less likely to occur than when the charge does not change or the charge is high. Reduction can be achieved. At this time, if the absolute value of the charge amount of the toner in the early developing order when it becomes an overlaid image exceeds 40 μC / g, even if it can be reduced by reducing the development order of dielectric repulsion, the effect becomes low, and transfer dust is reduced. I can't prevent it enough. On the other hand, if it is less than 15 μC / g, sufficient charging cannot be imparted, so that the background portion is fogged.
Furthermore, since the total amount of the fluidity-imparting agent can be reduced, it is effective in preventing white spots from being generated by silica such as silica filming.
[0021]
However, since yellow is a light color at this time, in an actual image, even if transfer dust or the like actually occurs, it is hardly noticeable, but preferably the fluidity-imparting agent and the charge amount are set according to the order of development. It is better to match. But you don't have to be caught by this.
Therefore, when reproducing a full color with three colors of yellow, cyan, and magenta except black, the relationship between magenta and cyan is magenta, cyan, and black toner when reproducing a full color with four colors. However, the faster the development order of yellow, magenta, cyan, and black toners, the more the fluidity imparting agent, and the absolute value of the charge amount of the fastest development order is 15 to 40 μC / g. Further, the faster the developing order, the higher the absolute value of the charge amount needs to be.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 and FIG. 2 show schematic diagrams of examples of image forming apparatuses adopting a full-color image forming method that can be applied in the present invention.
In these apparatuses, an electrostatic latent image is formed on the photosensitive member (electrostatic latent image carrier) (2) by a writing optical unit (not shown) that performs optical writing of image data corresponding to the original image. The optical unit is known per se and includes a laser diode, a polygon mirror, a polygon motor, an imaging lens, a reflection mirror, and the like. Although the photosensitive member (2) rotates clockwise as indicated by an arrow, a cleaning unit including a pre-cleaning static eliminator, a cleaning roller, a cleaning blade, etc., a static eliminating lamp, and a charger are not shown in the figure. A development pattern detector and the like are arranged. Each developing device (1a to 1d) supplies the developer to a developing sleeve that rotates so that the developer faces the photoreceptor in order to develop the electrostatic latent image. Here, the operation will be described below with an example in which the order of development operations (color toner formation order) is C (cyan), M (magenta), Y (yellow), and Bk (black) (however, the order is Not limited).
[0023]
When the printing operation (image formation) is started, optical writing of the C image data by laser light and latent image formation start from a predetermined timing (hereinafter referred to as C latent image. The same applies to M, Y, and Bk. ). In order to enable development from the leading edge of the C latent image, the developing sleeve starts rotating before the leading edge of the latent image reaches the developing position of the C developing device (1a), and the C latent image is changed to C toner (charge amount is reduced). Develop with minimum). Thereafter, the developing operation of the C latent image area is continued, but when the rear end portion of the C latent image passes the C developing position, the development inoperative state is set. This is completed at least before the next M image leading edge arrives.
Next, the C toner image formed on the photosensitive member (2) is transferred to the surface of the intermediate transfer member (3) (hereinafter, toner image transfer from the photosensitive member (2) to the intermediate transfer member (3) is “1”. Next transfer "). The primary transfer is performed by applying a transfer bias voltage in a state where the photosensitive member (2) and the intermediate transfer member (3) are in contact with each other. Then, the C, M, Y, and Bk toner images sequentially formed on the photosensitive member (2) are sequentially aligned on the same surface on the intermediate transfer member (3) to form a primary transfer image having four colors. Thereafter, batch transfer (secondary transfer) is performed on the transfer paper. The unit configuration and operation of the intermediate transfer member (3) will be described later.
[0024]
On the side of the photoreceptor (2), after the C process, the process proceeds to the M process using the M toner in which the addition amount and the charge amount of the fluidity imparting agent are controlled as in the above claims. An M latent image is formed by writing. The M developing device (1b) starts to rotate the developing sleeve after the rear end of the previous C latent image has passed with respect to the developing position and before the leading end of the M latent image reaches the M latent image. Develop. Thereafter, the development of the M latent image area is continued, but when the rear end portion of the latent image passes, the development non-operational state is set as in the case of the previous C developing device. This is also completed before the next Y latent image leading edge arrives. The Y and Bk processes are the same as the above-described C and M processes, except that each color toner is used, and the description thereof will be omitted. In the primary transfer, as described above, transfer pressure is applied at the time of image formation. In particular, when the order of image formation is the first color, four times of transfer pressure including its own image formation is applied. Since the cohesive force becomes strong, it is preferable to suppress the pressure as much as possible, but at this time, by using the photoreceptor (2) as a photoreceptor belt, the local pressure is released in the primary transfer. Therefore, it is preferable to use a photoreceptor belt.
[0025]
The intermediate transfer member (3) is constructed by a transfer bias roller, a drive roller, a driven roller, and the like, and is driven and controlled by a drive motor. Further, the intermediate transfer member may be constituted by a cleaning unit or the like as required, and in this case, a contact / separation operation is performed by a contact / separation mechanism. The timing of the contact / separation operation is separated from the surface of the intermediate transfer body (3) until the primary transfer of Bk (the fourth color of the final color in this example) is completed from the start of printing, and at the predetermined timing thereafter, Cleaning is performed by contacting the surface of the intermediate transfer member (3) with the contact / separation mechanism.
Also for the intermediate transfer member (3), since a local pressure can be released, a belt system is preferably used, and a combination of a photosensitive belt and an intermediate transfer belt is most preferable (FIG. 2). In addition, a small amount of zinc stearate is applied to the surface of the intermediate transfer body to reduce the surface energy of the intermediate transfer body and further improve the releasability from the toner layer, thereby further preventing transfer omission and transfer residue. It is desirable because it can improve cleaning properties.
[0026]
Secondary transfer to a transfer member such as transfer paper is composed of a transfer bias roller (4) (secondary transfer electric field forming means) and a contact / separation mechanism from an intermediate transfer member (3) (not shown). ing. The bias roller (4) is usually separated from the intermediate transfer member (3), but when the four color superimposed images formed on the surface of the intermediate transfer member (3) are collectively transferred to the transfer member (6). The timing is pressed by the contact / separation mechanism at 3 g / cm or more, and a predetermined bias voltage is applied to the roller (4) to transfer to a transfer member (6) such as transfer paper. At this time, the pressing force (linear pressure) is 3 g / cm or more. If the pressing force is less than 3 g / cm, the transfer material is liable to be displaced during secondary transfer, and the transfer material is liable to be displaced, and normal printing on the transfer material becomes impossible.
Further, the transfer member (6) on which the four-color superimposed image is collectively transferred from the surface of the intermediate transfer member (3) in this way is transported to the fixing device (5) and is transported to the fixing device (5). A full color print in which the toner image is fused and fixed by the fixing belt and the pressure roller can be obtained.
[0027]
Next, the electrostatic image developing toner of the present invention will be specifically described.
The toner for developing an electrostatic charge image of the present invention is a toner of four colors of yellow, cyan, magenta and black. These toners contain at least a binder resin, a colorant for each color, and a fluidizing agent.
As the binder resin used in the present invention, known resins can be used, and specifically, all those conventionally used as binder resins for toners are applied. Such resins include, for example, polyol resins, styrene / acrylic copolymers, styrene such as polystyrene, polychlorostyrene, and polyvinyltoluene, and homopolymers thereof, styrene / p-chlorostyrene copolymers, styrene. / Propylene copolymer, styrene / vinyl toluene copolymer, styrene / vinyl naphthalene copolymer, styrene / methyl acrylate copolymer, styrene / ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / Octyl acrylate copolymer, styrene / methyl methacrylate copolymer, styrene / ethyl methacrylate copolymer, styrene / butyl methacrylate copolymer, styrene / α-chloromethyl methacrylate copolymer, styrene / acrylonitrile Copolymer, styrene / vinyl Tyl ether copolymer, styrene / vinyl methyl ketone copolymer, styrene / butadiene copolymer, styrene / isoprene copolymer, styrene / acrylonitrile / indene copolymer, styrene / maleic acid copolymer, styrene / maleic acid ester Styrene copolymers such as copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol Examples thereof include resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, and paraffin waxes, and these are used alone or in combination of two or more.
[0028]
All known dyes and pigments can be used as the colorant.
Examples of yellow toners include naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, oil yellow, Hansa yellow (GR, A, RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anslagen Yellow BGL, Isoindolinone Yellow, etc. It is done.
[0029]
Examples of magenta toner include Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (E2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX , Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Marine, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Marine Light, Bon Marine Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigolet B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazo Nreddo, chrome vermilion, benzidine orange, perinone orange, oil orange, and the like.
[0030]
Examples of cyan toner include cobalt blue, cerulean blue, alkali blue rake, peacock blue rake, Victoria blue rake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indanthrene blue (RS, BC), indigo, Ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxazine violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridiane emerald green, pigment green B, naphthol green B, Green gold, acid green lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, Tobon and mixtures thereof and the like.
[0031]
Examples of the black toner include carbon black, nigrosine dye, iron black, and a cyan pigment as a complementary color.
The amount used is generally 0.1 to 50 parts by weight per 100 parts by weight of the binder resin for each color.
[0032]
The yellow, cyan, magenta and black toners of the present invention contain a fluidity imparting agent.
As the fluidity imparting agent, inorganic fine particles can be preferably used. The primary particle diameter of the inorganic fine particles is preferably 5 mμ to 2 μm, particularly preferably 5 mμ to 500 mμ. The specific surface area according to the BET method is 20 to 500 m. ² / G is preferable.
Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, parium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.
[0033]
In addition, polymer fine particles, such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, methacrylate esters, acrylate copolymers, polycondensation systems such as silicone, benzoguanamine, and nylon, thermosetting Examples thereof include polymer particles made of a resin.
[0034]
If necessary, the surface of the inorganic powder may be treated with a specific silane coupling agent, titanate coupling agent, silicone oil, organic acid, etc., or a specific resin may be coated to improve the hydrophobicity or charging characteristics of the surface of the inorganic powder. A method to do this has also been proposed.
Among them, silica particles obtained by reacting with an organosilicon compound such as silicone oil to replace the silanol groups on the surface of the silica particles with organic groups to make them hydrophobic are more preferred because they suppress transfer dust and improve transferability.
These fluidity-imparting agents may be different in each color toner or a plurality of imparting agents. The addition amount is preferably 0.01 to 5% by weight. More preferably 4% by weight or more. Further, it is necessary to make the addition amount and the charge amount as defined in the above claims in the order of development.
[0035]
The toner of the present invention may contain a charge control agent as necessary. Any known charge control agent can be used. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified) Quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives.
[0036]
In the present invention, the amount of charge control agent used is determined primarily by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is uniquely limited. Although it is not a thing, Preferably it is used in 0.1-10 weight part with respect to 100 weight part of binder resin. The range of 2 to 5 parts by weight is preferable. If the amount is less than 0.1 parts by weight, the toner is not practically negatively charged. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, and the density of the image is lowered due to spent or filming due to an increase in electrostatic attraction force with the carrier or the developing sleeve. Moreover, you may use a some charge control agent together as needed. Further, the addition amount may be changed depending on the developing order of each color toner.
[0037]
In order to provide the manufactured developer with releasability, a wax may be included in the manufactured developer. The wax has a melting point of preferably 40 to 120 ° C, particularly preferably 50 to 110 ° C. When the melting point of the wax is excessive, the fixing property at a low temperature may be insufficient. On the other hand, when the melting point is excessively low, the offset resistance and durability may be decreased. The melting point of the wax can be obtained by differential scanning calorimetry (DSC). That is, the melting peak value when a sample of several mg is ripened at a constant temperature increase rate, for example, (10 ° C./min) is defined as the melting point.
[0038]
Examples of the wax that can be used in the present invention include solid paraffin wax, microwax, rice wax, fatty acid amide wax, fatty acid wax, aliphatic monoketone, fatty acid metal salt wax, fatty acid ester wax, and partial kenne. Fatty acid ester wax, silicone varnish, higher alcohol, carnauba wax, and the like. Also, polyolefins such as low molecular weight polyethylene and polypropylene can be used. In particular, a polyolefin having a softening point of 70 to 150 ° C. by the ring and ball method is preferable, and a polyolefin having a softening point of 120 to 150 ° C. is more preferable.
[0039]
In the present invention, the toner alone may be used as a one-component developer to develop an electrostatic latent image, which may be developed by a so-called one-component development method, or a two-component developer obtained by mixing a toner and a carrier. It may be developed by a two-component development method that visualizes the electrostatic latent image.
Examples of the carrier used in the two-component development method include conventional ones such as iron powder, ferrite, and glass beads. These carriers may be those coated with resin. The resin used in this case is polyfluorinated carbon, polyvinyl chloride, polyvinylidene chloride, phenol resin, polyvinyl acetal, silicone resin or the like. In any case, the mixing ratio of toner and carrier is generally about 1.5 to 10.0 parts by weight of toner with respect to 100 parts by weight of carrier. These may be different depending on the developer of each color, but finally the charge amount of each color toner needs to be the charge amount as defined in the above claims.
[0040]
In producing a plurality of toners of the present invention, the constituent materials as described above are mixed in a mixer such as a Henschel mixer, and then mixed in a continuous kneader or a kneader such as a roll kneader. A method of kneading by heating and cooling and solidifying the kneaded product, followed by pulverization and classification to obtain a desired average particle diameter is preferred. Other methods include spray drying, polymerization, and microcapsule methods. Further, the toner thus obtained can be sufficiently mixed with a desired additive and a mixer such as a Henschel mixer, if necessary, to produce a toner.
[0041]
【Example】
Hereinafter, the present invention will be specifically described based on Examples and Comparative Examples, but the present invention is not limited only to these Examples. In the following examples, parts and% are based on weight unless otherwise specified.
[0042]
Example 1
<Yellow toner>
600 parts of water
C. I. Pigment yellow 180 1200 parts
Was stirred well with a flasher. To this, 1200 parts of polyester resin (acid value 3, hydroxyl value 25, Mn4500, Mw / Mn4.0, Tg 60 degrees) was added, kneaded at 150 degrees for 30 minutes, 1000 parts of xylene were added, and water and xylene were added for another hour. After removal (xylene was reduced to 100 ppm or less), it was cooled by rolling, pulverized with a pulverizer, and further passed twice with a three-roll mill to obtain a master batch pigment (MY-1).
100 parts of polyester resin
(Acid value 3, hydroxyl value 25, Mn4500, Mw / Mn4, Tg 60 degrees)
12 parts of the master batch (MY-1)
Charge control agent (E-84 manufactured by Orient Chemical Co., Ltd.) 3 parts
The above materials were mixed with a mixer, melt-kneaded with a two-roll mill, and the kneaded product was rolled and cooled. After that, a collision plate method using a jet mill (I type mill; manufactured by Nippon Pneumatic Industry Co., Ltd.) and a wind classifier using a swirling flow (DS classifier: manufactured by Nippon Pneumatic Industry Co., Ltd.) are performed. 7.5% by number of yellow colored particles were obtained.
The particle size distribution was measured with a Coulter Counter TAII manufactured by Coulter.
100 parts of the above yellow colored particles
Fluidity-imparting agent (Cabot Corporation: TS-720) 1.0 part
Were mixed with a mixer to obtain a yellow toner.
[0043]
<Magenta toner>
600 parts of water
C. I. Pigment RED 57: 1 1200 parts
Was stirred well with a flasher. To this, 1200 parts of polyester resin (acid value 3, hydroxyl value 25, Mn4500, Mw / Mn4.0, Tg 60 degrees) was added, kneaded at 150 degrees for 30 minutes, 1000 parts of xylene were added, and water and xylene were added for another hour. After removal (xylene was reduced to 100 ppm or less), rolled and cooled, pulverized with a pulverizer, and further passed twice with a three-roll mill to obtain a master batch pigment (MM-1).
100 parts of polyester resin
(Acid value 3, hydroxyl value 25, Mn4500, Mw / Mn4, Tg 60 degrees)
9 parts of the above master batch (MM-1)
Charge control agent (E-84 manufactured by Orient Chemical Co., Ltd.) 3 parts
In the same manner as the yellow colored particles, magenta colored particles having a weight average particle size of 7.0 μm and 4 μm or less having 7.5% by number were obtained.
100 parts of the magenta colored particles
Fluidity-imparting agent (Cabot Corporation: TS-720) 0.8 parts
Were mixed with a mixer to obtain a magenta toner.
[0044]
<Cyan toner>
600 parts of water
C. I. Pigment blue 55: 3 1200 parts
Was stirred well with a flasher. To this, 1200 parts of polyester resin (acid value 3, hydroxyl value 25, Mn4500, Mw / Mn4.0, Tg 60 degrees) was added, kneaded at 150 degrees for 30 minutes, 1000 parts of xylene were added, and water and xylene were added for another hour. After removal (xylene was reduced to 100 ppm or less), it was cooled by rolling, pulverized with a pulverizer, and further passed twice with a three-roll mill to obtain a master batch pigment (MC-1).
100 parts of polyester resin
(Acid value 3, hydroxyl value 25, Mn4500, Mw / Mn4, Tg 60 degrees)
9 parts of the above master batch (MC-1)
Charge control agent (E-84 manufactured by Orient Chemical Co., Ltd.) 3 parts
In the same manner as the yellow colored particles, cyan colored particles having a weight average particle diameter of 6.9 μm and 4 μm or less having 8.5 number% were obtained.
100 parts of the above-mentioned cyan colored particles
Flowability imparting agent (Cabot TS-720) 0.6 parts
Were mixed with a mixer to obtain cyan toner.
[0045]
<Black toner>
100 parts of polyester resin
(Acid value 3, hydroxyl value 25, Mn4500, Mw / Mn4, Tg 60 degrees)
7 parts of carbon black (PRINTEX70 manufactured by Cabot)
Charge control agent (E-84 manufactured by Orient Chemical Co., Ltd.) 3 parts
In the same manner as the yellow colored particles, black colored particles having a weight average particle size of 7.1 μm and 4 μm or less of 6.0 number% were obtained.
100 parts of the above black colored particles
Fluidity-imparting agent (Cabot Corporation: TS-720) 0.4 parts
Were mixed with a mixer to obtain a black toner.
[0046]
The obtained one-component developer is set in a digital full-color printer (Ricoh Ipsio COLOR 5000) remodeling machine (photosensitive belt, intermediate transfer belt, with zinc stearate coating mechanism), and developing order of yellow, magenta, cyan and black Thus, a full-color image having a single color, two colors, three colors without black, and four colors was formed. The secondary transfer pressure was 30 g / cm. Further, when the charge amount on the developing roller and the toner adhesion amount were measured by a suction method, -22.0 [mu] C / g, -21.3 [mu] C / g, -20.1 C / g, in the order of yellow, magenta, cyan, and black, The absolute value of the charge amount decreased in the order of development at −19.7 μC / g. The thin layer property on the developing roller was uniform and good. The obtained print images were all clear from single color to four color overlap, and the image edge portion was observed with a 30 × magnifier, but the image was sharp and sharp. Also, transfer omission and transfer blur could not be confirmed even with a 30-fold loupe, and neither image unevenness nor background fogging was observed.
[0047]
Example 2
<Yellow toner>
The same yellow toner as in Example 1 was used.
<Cyan toner>
The cyan colored particles of Example 1 were used.
100 parts of the above colored particles
Fluidity-imparting agent (Cabot Corporation: TS-720) 0.8 parts
Were mixed with a mixer to obtain cyan toner.
<Magenta toner>
The magenta colored particles of Example 1 were used.
100 parts of the above colored particles
Flowability imparting agent (Cabot Corp .: TS-720) 0.6 parts
Were mixed with a mixer to obtain a magenta toner.
<Black toner>
The same black toner as in Example 1 was used.
[0048]
The obtained one-component developer is set in a digital full-color printer (Ipsio COLOR 5000 manufactured by Ricoh Co., Ltd.), and is developed in the order of development of yellow, cyan, magenta, and black. A color full-color image was formed. At this time, the secondary transfer pressure was 30 g / cm. Further, the charge amount on the developing roller and the toner adhesion amount were measured by a suction method. As a result, yellow, cyan, magenta, and black were −22.0 μC / g, −20.9 μC / g, −20.5 μC / g, The absolute value of the charge amount decreased in the order of development at −19.7 μC / g. The thin layer property on the developing roller was uniform and good. Further, the obtained print image was clear in all colors of single color to four colors, and the image edge portion was observed with a 30 × magnifier, but it was a sharp image with no dust. Also, transfer omission and transfer blur could not be confirmed even with a 30-fold loupe, and neither image unevenness nor background fogging was observed.
[0049]
Example 3
<Black toner>
100 parts of polyol resin
(Mn 3700, Mw / Mn 4.2, Tg 62 degrees)
7 parts of carbon black (Cabot: PRINTEX70)
Charge control agent (Orient: E-84) 4 parts
In the same manner as in Example 1, black colored particles having a weight average particle diameter of 6.7 μm and 4 μm or less and 9.5% by number were obtained.
100 parts of the above black colored particles
Fluidity-imparting agent (Cabot Corporation: TS-720) 1.0 part
Were mixed with a mixer to obtain a black toner.
[0050]
<Magenta toner>
600 parts of water
C. I. Pigment RED 57: 1 1200 parts
Was stirred well with a flasher. After adding 1200 parts of polyol resin (Mn3700, Mw / Mn4.2, Tg 62 degrees), kneading at 150 degrees for 30 minutes, adding 1000 parts of xylene, and further removing water and xylene for 1 hour (xylene is 100 ppm or less) And rolled and cooled, pulverized with a pulverizer, and further passed twice with a three-roll mill to obtain a master batch pigment (MM-2).
100 parts of polyol resin
(Mn 3700, Mw / Mn 4.2, Tg 62 degrees)
9 parts of the above master batch (MM-2)
Charge control agent (E-84 manufactured by Orient Chemical Co., Ltd.) 4 parts
In the same manner as in Example 1, magenta colored particles having a weight average particle size of 7.0 μm and 4 μm or less of 8.5% by number were obtained.
100 parts of the magenta colored particles
Fluidity-imparting agent (Cabot Corporation: TS-720) 0.8 parts
Were mixed with a mixer to obtain a magenta toner.
[0051]
<Yellow toner>
600 parts of water
C. I. Pigment yellow 180 1200 parts
Was stirred well with a flasher. After adding 1200 parts of polyol resin (Mn3700, Mw / Mn4.2, Tg 62 degrees), kneading at 150 degrees for 30 minutes, adding 1000 parts of xylene, and further removing water and xylene for 1 hour (xylene is 100 ppm or less) And rolled and cooled, pulverized with a pulverizer, and further passed twice with a three-roll mill to obtain a master batch pigment (MY-2).
100 parts of polyol resin
(Mn 3700, Mw / Mn 4.2, Tg 62 degrees)
12 parts of the master batch (MY-2)
Charge control agent (E-84 manufactured by Orient Chemical Co., Ltd.) 4 parts
In the same manner as in Example 1, yellow colored particles having a weight average particle size of 6.9 μm and 4 μm or less of 6.5% by number were obtained.
100 parts of the above yellow colored particles
Flowability imparting agent (Cabot Corp .: TS-720) 0.6 parts
Were mixed with a mixer to obtain a yellow toner.
[0052]
<Cyan toner>
600 parts of water
C. I. Pigment blue 55: 3 1200 parts
Was stirred well with a flasher. After adding 1200 parts of polyol resin (Mn3700, Mw / Mn4.2, Tg 62 degrees), kneading at 150 degrees for 30 minutes, adding 1000 parts of xylene, and further removing water and xylene for 1 hour (xylene is 100 ppm or less) And rolled and cooled, pulverized with a pulverizer, and further passed twice with a three-roll mill to obtain a master batch pigment (MC-2).
100 parts of polyol resin
(Mn 3700, Mw / Mn 4.2, Tg 62 degrees)
9 parts of the above master batch (MC-2)
Charge control agent (E-84 manufactured by Orient Chemical Co., Ltd.) 4 parts
In the same manner as in Example 1, cyan colored particles having a weight average particle diameter of 6.9 μm and 4 μm or less having 8.5% by number were obtained.
100 parts of the above-mentioned cyan colored particles
Fluidity-imparting agent (Cabot Corporation: TS-720) 0.4 parts
Were mixed with a mixer to obtain cyan toner.
[0053]
The obtained one-component developer is set in a digital full-color printer (Ipsio COLOR 5000 manufactured by Ricoh Co., Ltd.) and converted into black, magenta, yellow, and cyan in the order of development, one color, two colors, and three colors without black. A color full-color image was formed. At this time, the secondary transfer pressure was 30 g / cm. Further, when the charge amount on the developing roller and the toner adhesion amount were measured by a suction method, black, magenta, yellow, and cyan were in the order of −24.0 μC / g, −23.3 μC / g, −22.3 μC / g, The absolute value of the charge amount decreased to -20.9 μC / g in the order of development. The thin layer property on the developing roller was uniform and good. The obtained print images were all clear from single color to four color overlap, and the image edge portion was observed with a 30 × magnifier, but the image was sharp and sharp. Also, transfer omission and transfer blur could not be confirmed even with a 30-fold loupe, and neither image unevenness nor background fogging was observed.
[0054]
Example 4
Using the same toner as in Example 3, for each color, the ferrite particles having an average particle diameter of 50 μm are mixed with 100 parts of a carrier having a silicone resin as a surface coat, and mixed at a ratio of 5 parts by a tumbler mixer. did.
Set the resulting two-component developer on a digital full-color copy (Ricoh Pretail 650) remodeling machine (photosensitive drum, intermediate transfer belt, with zinc stearate coating mechanism), and develop black, magenta, yellow, and cyan in the order of development. Thus, a full-color image of a single color, two colors, three colors without black, and four colors was formed. The secondary transfer pressure at this time was 50 g / cm. When the charge amount of the developer was measured by the blow-off method, it was found that black, magenta, yellow, and cyan were in the order of −30.1 μC / g, −29.1 μC / g, −27.9 μC / g, and −26.5 μC / g. The absolute value of the charge amount decreased in the order of development. The obtained print images were all clear from single color to four color overlap, and the image edge portion was observed with a 30 × magnifier, but the image was sharp and sharp. Also, transfer omission and transfer blur could not be confirmed even with a 30-fold loupe, and neither image unevenness nor background fogging was observed.
[0055]
Example 5
<Black toner>
The same black toner as in Example 3 was used.
<Magenta toner>
A magenta toner similar to that in Example 3 was used.
<Yellow toner>
The same yellow colored particles as in Example 3 were used.
100 parts of the above yellow colored particles
Fluidity-imparting agent (Cabot Corporation: TS-720) 1.0 part
Were mixed with a mixer to obtain a yellow toner.
<Cyan toner>
The same cyan toner as in Example 3 was used.
[0056]
The obtained one-component developer is set in a digital full-color printer (Ricoh Ipsio COLOR 5000) remodeling machine, black, magenta, yellow, cyan in the order of development, two colors, two colors, three colors without black. A color full-color image was formed. At this time, the secondary transfer pressure was 30 g / cm. Further, when the charge amount on the developing roller and the toner adhesion amount were measured by a suction method, black, magenta, yellow, and cyan were in the order of −24.0 μC / g, −23.3 μC / g, −24.5 μC / g, With the exception of -20.9 μC / g and yellow, the absolute value of the charge amount decreased with the order of development. The thin layer property on the developing roller was uniform and good. The obtained print image was clearly visible from a single color to four colors, but when the image edge portion was observed with a 30-fold magnifier, red and magenta and yellow were superimposed, and three colors and four colors were superimposed. Chile could be confirmed in the overlap. Further, the transfer omission could not be confirmed even with a 30 × magnifying glass, and neither image unevenness nor background fogging was observed.
[0057]
Example 6
<Yellow toner>
The same yellow colored particles as in Example 1 were used.
100 parts of the above yellow colored particles
Fluidity-imparting agent (made by Nippon Aerosil Co., Ltd .: RY-50) 2.0 parts
Were mixed with a mixer to obtain a yellow toner.
<Magenta toner>
The same magenta colored particles as in Example 1 were used.
100 parts of the magenta colored particles
Fluidity imparting agent (manufactured by Nippon Aerosil Co., Ltd .; RY-50) 2.0 parts
Were mixed with a mixer to obtain a magenta toner.
<Cyan toner>
The same cyan colored particles as in Example 1 were used.
100 parts of the above-mentioned cyan colored particles
Fluidity-imparting agent (manufactured by Nippon Aerosil Co., Ltd .: RY-50) 1.8 parts
Were mixed with a mixer to obtain cyan toner.
<Black toner>
The same black colored particles as in Example 1 were used.
100 parts of the above black colored particles
1.6 parts fluidity-imparting agent (Nippon Aerosil Co., Ltd .: RY-50)
Were mixed with a mixer to obtain a black toner.
[0058]
The obtained one-component developer is set in a digital full-color printer (Ricoh Ipsio COLOR 5000) remodeled machine, and in the order of development of yellow, magenta, cyan, and black, one color, two colors, three colors without black, A color full-color image was formed. At this time, the secondary transfer pressure was 30 g / cm. Further, when the charge amount on the developing roller and the toner adhesion amount were measured by the suction method, yellow, magenta, cyan, and black were −22.0 μC / g, −22.0 μC / g, −20.5 μC / g, It was −19.9 μC / g. The thin layer property on the developing roller was uniform and good. The obtained print image was clearly visible from a single color to four colors, but when the image edge portion was observed with a 30-fold magnifier, red and magenta and yellow were superimposed, and three colors and four colors were superimposed. Chile could be confirmed in the overlap. Further, the transfer omission could not be confirmed even with a 30 × magnifying glass, and neither image unevenness nor background fogging was observed.
[0059]
Example 7
<Yellow toner>
The same yellow colored particles as in Example 1 were used.
100 parts of the above yellow colored particles
Fluidity-imparting agent (manufactured by Wacker: H2000) 1.0 part
Were mixed with a mixer to obtain a yellow toner.
<Magenta toner>
The same magenta colored particles as in Example 1 were used.
100 parts of the magenta colored particles
Fluidity-imparting agent (manufactured by Wacker: H2000) 0.8 part
Were mixed with a mixer to obtain a magenta toner.
<Cyan toner>
The same cyan toner as in Example 1 was used.
<Black toner>
The same black toner as in Example 1 was used.
[0060]
The obtained one-component developer is set in a digital full-color printer (Ricoh Ipsio COLOR 5000) remodeled machine, and in the order of development of yellow, magenta, cyan, and black, one color, two colors, three colors without black, A color full-color image was formed. At this time, the secondary transfer pressure was 30 g / cm. Further, the charge amount on the developing roller and the toner adhesion amount were measured by a suction method. As a result, yellow, magenta, cyan, and black were in the order of −24.0 μC / g, −22.8 μC / g, −20.2 μC / g, -19.7 μC / g. The thin layer property on the developing roller was uniform and good. The obtained print image was clearly visible from a single color to four colors, but when the image edge portion was observed with a 30-fold magnifier, red and magenta and yellow were superimposed, and three colors and four colors were superimposed. Chile could be confirmed in the overlap. Further, the transfer omission could not be confirmed even with a 30 × magnifying glass, and neither image unevenness nor background fogging was observed.
[0061]
Example 8
<Yellow toner>
The same yellow toner as in Example 7 was used.
<Magenta toner>
The same magenta colored particles as in Example 1 were used.
100 parts of the magenta colored particles
Flowability imparting agent (Nippon Aerosil Co., Ltd .: R972) 0.8 parts
Were mixed with a mixer to obtain a magenta toner.
<Cyan toner>
The same cyan toner as in Example 1 was used.
<Black toner>
The same black colored particles as in Example 1 were used.
100 parts of the above black colored particles
Fluidity imparting agent (Nippon Aerosil Co., Ltd .: R972) 0.4 parts
Were mixed with a mixer to obtain a black toner.
[0062]
The obtained one-component developer is set in a digital full-color printer (Ricoh Ipsio COLOR 5000) remodeling machine, and in the order of development of yellow, magenta, cyan, and black, one color, two colors are superimposed, and three colors are superimposed without black. A color full-color image was formed. At this time, the secondary transfer pressure was 30 g / cm. Further, the charge amount on the developing roller and the toner adhesion amount were measured by a suction method. As a result, yellow, magenta, cyan, and black were −24.0 μC / g, −21.1 μC / g, −20.2 μC / g, -19.0 μC / g. The thin layer property on the developing roller was uniform and good. The obtained print images were all clear from single color to four color overlap, and the image edge portion was observed with a 30 × magnifier, but the image was sharp and sharp. Although transfer omissions could not be confirmed by visual observation, with a 30x magnifier, yellow and magenta overlapped with some red omissions, and some omissions were observed with 4 color overlays, but there were no image irregularities and background fogging. There was not.
[0063]
Example 9
Using the same toner as in Example 1, 5 parts of a carrier having a silicone resin surface-coated on ferrite particles having an average particle diameter of 50 μm for each color was mixed in a turbuler mixer at a ratio of 5 parts. did.
The obtained two-component developer is set in the order of development of yellow, magenta, cyan, and black using the image forming machine shown in FIG. 1 (photosensitive drum, intermediate transfer drum, and zinc stearate coating mechanism), and is monochromatic. A full-color image of two colors, three colors without black, and four colors was formed. The secondary transfer pressure at this time was 50 g / cm. Further, when the charge amount of the developer was measured by the blow-off method, yellow, magenta, cyan, and black in the order of −24.0 μC / g, −22.8 μC / g, −22.4 μC / g, and −21.5 μC / g. The absolute value of the charge amount decreased in the order of development. The obtained print images were all clear from single color to four color overlap, and the image edge portion was observed with a 30-fold loupe, but there was no dust and there was no background fogging. However, although transfer omissions could not be confirmed by visual observation, a slight omission of transfer was confirmed as a whole including a single color with a 30 × magnifier.
[0064]
Example 10
<Yellow toner>
The same yellow toner of Example 7 was used.
<Magenta toner>
The same magenta toner as in Example 7 was used.
<Cyan toner>
The same cyan colored particles as in Example 1 were used.
100 parts of the above-mentioned cyan colored particles
Flowability imparting agent (manufactured by Wacker: H2000) 0.6 part
Were mixed with a mixer to obtain a cyan toner.
<Black toner>
The same black colored particles as in Example 1 were used.
100 parts of the above black colored particles
Fluidity-imparting agent (manufactured by Wacker: H2000)
Were mixed with a mixer to obtain a black toner.
[0065]
Set the resulting one-component developer on a digital full-color printer (Ricoh Ipsio COLOR 5000) remodeled machine, set it in the order of development of yellow, magenta, cyan, and black, and then overlay one color, two colors, and three colors without black A full-color image of four colors was formed. The secondary transfer pressure at this time was 50 g / cm. Further, the charge amount on the developing roller and the toner adhesion amount were measured by a suction method. As a result, yellow, magenta, cyan, and black were −24.0 μC / g, −22.8 μC / g, −22.4 μC / g, The absolute value of the charge amount decreased in the order of −21.5 μC / g. The obtained print images were all clear from single color to four color overlay, and the image edge portion was observed with a 30 × magnifier, but there was no dust and there was no background fogging. However, although transfer omissions could not be visually confirmed, with the 30 × magnifier, some transfer omissions were confirmed on the whole except for the black single color.
[0066]
Example 11
<Yellow toner>
The same yellow colored particles as in Example 1 were used.
100 parts of the above yellow colored particles
1.4 parts of fluidity-imparting agent (manufactured by Wacker: H2000)
Were mixed with a mixer to obtain a yellow toner.
<Magenta toner>
The same magenta colored particles as in Example 1 were used.
100 parts of the magenta colored particles
1.2 parts of fluidity-imparting agent (manufactured by Wacker: H2000)
Were mixed with a mixer to obtain a magenta toner.
<Cyan toner>
The same cyan colored particles as in Example 1 were used.
100 parts of the above-mentioned cyan colored particles
Fluidity-imparting agent (manufactured by Wacker: H2000) 1.0 part
Were mixed with a mixer to obtain a cyan toner.
<Black toner>
The same black colored particles as in Example 1 were used.
100 parts of the above black colored particles
Fluidity-imparting agent (manufactured by Wacker: H2000) 0.8 part
Were mixed with a mixer to obtain a black toner.
[0067]
The obtained one-component developer is set in a digital full-color printer (Ricoh Ipsio COLOR 5000) remodeling machine, and in the order of development of yellow, magenta, cyan, and black, one color, two colors are superimposed, and three colors are superimposed without black. A color full-color image was formed. At this time, the secondary transfer pressure was 30 g / cm. Further, the charge amount on the developing roller and the toner adhesion amount were measured by a suction method. As a result, yellow, magenta, cyan, and black were −28.0 μC / g, −26.3 μC / g, −23.8 μC / g, -23.0 μC / g. The thin layer property on the developing roller was uniform and good. Further, the obtained print image was clearly visible from a single color to four colors superimposed, but when the image edge portion was observed with a 30-fold magnifier, dust was confirmed in all of the superimposed images excluding the single color. Further, the transfer omission could not be confirmed even with a 30 × magnifying glass, and neither image unevenness nor background fogging was observed.
[0068]
Example 12
For each color, the same toner as in Example 1 was used.
The obtained one-component developer is set in a digital full-color printer (Ricoh Ipsio COLOR 5000) remodeling machine, and in the order of development of yellow, magenta, cyan, and black, one color, two colors are superimposed, and three colors are superimposed without black. A color full-color image was formed. At this time, the secondary transfer pressure was 30 g / cm. Further, the zinc stearate coating mechanism on the intermediate transfer member was removed and used. When the charge amount on the developing roller and the toner adhesion amount were measured by the suction method, the same results as in Example 1 were obtained in the order of yellow, magenta, cyan, and black, with −22.0 μC / g, −21.3 μC / g, -20.1 µC / g and -19.7 µC / g. The thin layer property on the developing roller was uniform and good. The obtained print images were all clear from single color to four color overlap, and the image edge portion was observed with a 30-fold loupe, but there was no dust and there was no background fogging. However, although transfer omissions could not be visually confirmed, with the 30 × magnifier, some transfer omissions were confirmed on the whole except for the black single color.
[0069]
Example 13
<Yellow toner>
The same yellow colored particles as in Example 1 were used.
100 parts of the above yellow colored particles
Fluidity-imparting agent (manufactured by Nippon Aerosil Co., Ltd .: TS-720) 1.4 parts
Were mixed with a mixer to obtain a yellow toner.
<Magenta toner>
The same magenta colored particles as in Example 1 were used.
100 parts of the magenta colored particles
1.2 parts of fluidity-imparting agent (manufactured by Nippon Aerosil Co., Ltd .; TS-720)
Were mixed with a mixer to obtain a magenta toner.
<Cyan toner>
The same cyan colored particles as in Example 1 were used.
100 parts of the above-mentioned cyan colored particles
Fluidity-imparting agent (Nippon Aerosil Co., Ltd .: TS-720) 1.0 part
Were mixed with a mixer to obtain a cyan toner.
<Black toner>
The same black colored particles as in Example 1 were used.
100 parts of the above black colored particles
Flowability imparting agent (Nippon Aerosil Co., Ltd .: TS-720) 0.8 parts
Were mixed with a mixer to obtain a black toner.
[0070]
The obtained one-component developer is set in a digital full-color printer (Ricoh Ipsio COLOR 5000) remodeling machine, and in the order of development of yellow, magenta, cyan, and black, one color, two colors are superimposed, and three colors are superimposed without black. A color full-color image was formed. At this time, the secondary transfer pressure was 30 g / cm 2. Further, the charge amount on the developing roller and the toner adhesion amount were measured by a suction method. As a result, black, magenta, yellow, and cyan were −30.0 μC / g, −27.3 μC / g, −24.3 μC / g, The absolute value of the charge amount decreased in the order of development at −23.2 μC / g. The thin layer property on the developing roller was uniform and good. The obtained print images were all clear from single color to four color overlap, and the image edge portion was observed with a 30 × magnifier, but the image was sharp and sharp. Also, transfer omission and transfer blur could not be confirmed even with a 30-fold loupe, and neither image unevenness nor background fogging was observed.
[0071]
Comparative Example 1
For yellow, magenta, and cyan, the same toner as in Example 1 was used. <Black toner>
The same black colored particles as in Example 1 were used.
100 parts of the above black colored particles
1.2 parts of fluidity-imparting agent (Cabot Corporation: TS-720)
Were mixed with a mixer to obtain a black toner.
[0072]
The obtained one-component developer is set in a digital full-color printer (Ricoh Ipsio COLOR 5000) remodeling machine, and in the order of development of yellow, magenta, cyan, and black, one color, two colors are superimposed, and three colors are superimposed without black. A color full-color image was formed. At this time, the secondary transfer pressure was 30 g / cm. Further, the zinc stearate coating mechanism on the intermediate transfer member was removed and used. When the charge amount on the developing roller and the toner adhesion amount were measured by a suction method, yellow, magenta, cyan, and black were −22.0 μC / g, −21.3 μC / g, −20.1 μC / g, − It was 23.5 μC / g. The thin layer property on the developing roller was uniform and good. Further, the obtained print image was clear from single color to three color superposition not containing black, and the image edge portion was observed with a 30 × magnifier, but it was a sharp image with no dust. However, all of the superimposed images containing black were so bad that the dust could be visually confirmed and could not be used. Further, the transfer omission could not be confirmed even with a 30 × magnifying glass, and neither image unevenness nor background fogging was observed.
[0073]
Comparative Example 2
<Yellow toner>
The same yellow toner as in Example 7 was used.
<Magenta toner>
The same magenta colored particles as in Example 1 were used.
100 parts of the magenta colored particles
Fluidity-imparting agent (manufactured by Wacker: H2000) 1.0 part
Were mixed with a mixer to obtain a magenta toner.
<Cyan toner>
The same cyan toner as in Example 11 was used.
<Black toner>
The same black colored particles as in Example 1 were used.
100 parts of the above-mentioned cyan colored particles
Fluidity-imparting agent (manufactured by Wacker: H2000) 1.0 part
Were mixed with a mixer to obtain a black toner.
[0074]
The obtained one-component developer is set in a digital full-color printer (Ricoh Ipsio COLOR 5000) remodeling machine, and in the order of development of yellow, magenta, cyan, and black, one color, two colors are superimposed, and three colors are superimposed without black. A color full-color image was formed. At this time, the secondary transfer pressure was 30 g / cm. Further, the charge amount on the developing roller and the toner adhesion amount were measured by a suction method. As a result, yellow, magenta, cyan, and black in the order of −24.0 μC / g, −24.2 μC / g, −23.8 μC / g, It was −23.9 μC / g. The thin layer property on the developing roller was uniform and good. Further, the obtained print image was good with respect to the background fogging, but in the superimposed images other than the single color, all the dust was severe, and the four-color overlap was not particularly durable. In addition, regarding the omission of transfer, the overlaid image was also visually observed as omission of transfer, and the magenta color transfer unevenness was particularly severe.
[0075]
Comparative Example 3
<Yellow toner>
The same yellow colored particles as in Example 3 were used.
100 parts of the above yellow colored particles
Fluidity-imparting agent (manufactured by Wacker: H2000) 1.0 part
Were mixed with a mixer to obtain a yellow toner.
<Magenta toner>
The same magenta colored particles as in Example 3 were used.
100 parts of the magenta colored particles
Fluidity-imparting agent (manufactured by Wacker: H2000) 0.8 part
Were mixed with a mixer to obtain a magenta toner.
<Cyan toner>
The same cyan colored particles as in Example 3 were used.
100 parts of the above-mentioned cyan colored particles
Fluidity-imparting agent (Cabot Corporation: TS-720) 0.8 parts
Were mixed with a mixer to obtain a cyan toner.
<Black toner>
The same black colored particles as in Example 3 were used.
100 parts of the above black colored particles
Flowability imparting agent (Cabot Corp .: TS-720) 0.6 parts
Were mixed with a mixer to obtain a black toner.
[0076]
The obtained one-component developer is set in a digital full-color printer (Ricoh Ipsio COLOR 5000) remodeling machine, and in the order of development of yellow, magenta, cyan, and black, one color, two colors are superimposed, and three colors are superimposed without black. A color full-color image was formed. At this time, the secondary transfer pressure was 30 g / cm. Further, the charge amount on the developing roller and the toner adhesion amount were measured by a suction method. As a result, yellow, magenta, cyan, and black were −26.0 μC / g, −25.3 μC / g, −23.1 μC / g, It was −22.4 μC / g. The thin layer property on the developing roller was uniform and good. Also, the obtained print image was all clear from single color to 4 color overlay, and there was no background fogging, but when the image edge part was observed with a 30x magnifier, there was some dust on the part where magenta and cyan overlapped, but the whole The image was sharp. However, with regard to transfer omission, there was an omission of transfer that can be visually confirmed in the blue where cyan and magenta overlap.
[0077]
Comparative Example 4
<Yellow toner>
The same yellow toner of Example 1 was used.
<Magenta toner>
100 parts of polyester resin
(Acid value 3, hydroxyl value 25, Mn4500, Mw / Mn4, Tg 60 degrees)
Magenta masterbatch (MM-1) 9 parts
Charge control agent (E-84 manufactured by Orient Chemical Co., Ltd.) 2 parts
In the same manner as the yellow colored particles described in Example 1, magenta colored particles having a weight average particle size of 7.0 μm and 4 μm or less having 8.0% by number were obtained.
100 parts of the magenta colored particles
Fluidity-imparting agent (Cabot Corporation: TS-720) 0.8 parts
Were mixed with a mixer to obtain a magenta toner.
<Cyan toner>
The same cyan toner as in Example 1 was used.
<Black toner>
The same black toner as in Example 1 was used.
[0078]
The obtained one-component developer is set in a digital full-color printer (Ricoh Ipsio COLOR 5000) remodeling machine, and in the order of development of yellow, magenta, cyan, and black, one color, two colors are superimposed, and three colors are superimposed without black. A color full-color image was formed. At this time, the secondary transfer pressure was 30 g / cm. Further, when the charge amount on the developing roller and the toner adhesion amount were measured by a suction method, -22.0 [mu] C / g, -18.0 [mu] C / g, -20.2 [mu] C / g, yellow, magenta, cyan, and black in this order. -19.5 μC / g. The thin layer property on the developing roller was uniform and good. Further, the obtained print image was particularly blue with magenta and cyan overlapping, and the transfer dust was so bad that it could not be used. However, the transfer omission could not be confirmed even with a 30 × magnifier, and neither image unevenness nor background fogging was observed.
[0079]
Comparative Example 5
<Yellow toner>
The same yellow colored particles as in Example 1 were used.
100 parts of the above yellow colored particles
Fluidity-imparting agent (Nippon Aerosil Co., Ltd .: RY-50) 1.0 part
Were mixed with a mixer to obtain a yellow toner.
<Magenta toner>
The same magenta colored particles as in Example 1 were used.
100 parts of the magenta colored particles
Fluidity imparting agent (manufactured by Nippon Aerosil Co., Ltd .; RY-50) 0.8 parts
Were mixed with a mixer to obtain a magenta toner.
<Cyan toner>
The same cyan colored particles as in Example 1 were used.
100 parts of the above-mentioned cyan colored particles
Flowability imparting agent (Nippon Aerosil Co., Ltd .: RY-50) 0.6 parts
Were mixed with a mixer to obtain a cyan toner.
<Black toner>
The same black colored particles as in Example 1 were used.
100 parts of the above black colored particles
Fluidity imparting agent (Nippon Aerosil Co., Ltd .: RY-50) 0.4 parts
Were mixed with a mixer to obtain a black toner.
[0080]
The obtained one-component developer is set in a digital full-color printer (Ricoh Ipsio COLOR 5000) remodeling machine, and in the order of development of yellow, magenta, cyan, and black, one color, two colors are superimposed, and three colors are superimposed without black. A color full-color image was formed. At this time, the secondary transfer pressure was 30 g / cm. Further, when the charge amount on the developing roller and the toner adhesion amount were measured by the suction method, -14.5 μC / g, −14.0 μC / g, −13.2 μC / g, It was −11.8 μC / g. The thin layer property on the developing roller was uniform and good. The obtained print images were all clear from single color to four color overlap, and the image edge portion was observed with a 30 × magnifier, but the image was sharp and sharp. Further, the transfer omission could not be confirmed with a 30-fold magnifier, and no unevenness of the image was observed, but the image with a noticeable fog on the background surface was observed.
[0081]
Comparative Example 6
<Yellow toner>
The same yellow toner as in Example 13 was used.
<Magenta toner>
The same magenta toner as in Example 13 was used.
<Cyan toner>
The same cyan toner as in Example 13 was used.
<Black toner>
The same black toner as in Example 13 was used.
[0082]
The toner of each color obtained was used, and for each color, ferrite particles having an average particle diameter of 50 μm and 100 parts of a carrier having a silicone resin as a surface coat were mixed at a ratio of 5 parts by a tumbler mixer to obtain a developer. .
[0083]
Set the resulting two-component developer on a digital full-color copy (Ricoh Pretail 650) remodeling machine (photosensitive drum, intermediate transfer belt, with zinc stearate coating mechanism), and develop black, magenta, yellow, and cyan in the order of development. Thus, a full-color image of a single color, two colors, three colors without black, and four colors was formed. The secondary transfer pressure at this time was 50 g / cm. Further, when the charge amount of the developer was measured by the blow-off method, it was −42.0 μC / g, −40.7 μC / g, −37.8 μC / g, and −35.4 μC / g in the order of yellow, magenta, cyan, and black. The absolute value of the charge amount decreased in the order of development. The obtained print image was clear for a single color, and was also clear for the superimposed image of cyan and black, but the two- to four-color superimposed image using yellow and magenta was also transferred visually. Chile was terrible. Neither transfer omission nor transfer blur could be confirmed even with a 30-fold magnifier, and neither image unevenness nor background fogging was observed.
[0084]
Tables 1 to 4 show a summary of Examples 1 to 13 and Comparative Examples 1 to 6.
[0085]
[Table 1]

[Table 2]

[Table 3]

[Table 4]

[0086]
【The invention's effect】
As described above, as is clear from the detailed and specific description, according to the present invention, yellow, cyan, magenta, and black are used in the formation of a full-color image using the intermediate transfer method and the contact (secondary) transfer method. By adjusting the toner charge amount in the color toner, and further optimizing the addition amount of the fluidity imparting agent and the toner charge amount in the order of development, high reproducibility without transfer dust, transfer omission, transfer blur and background fogging An image forming method capable of forming an image, an image forming apparatus, and an electrostatic image developing toner used therefor can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of an example of a full-color image forming apparatus of the present invention.
FIG. 2 is a schematic view of another example of the full-color image forming apparatus of the present invention.
[Explanation of symbols]
(Figure 1)
1a-1d: Developer
2: Photosensitive drum
3: Intermediate transfer drum
4: Transfer roller
5: Fixing roller
6: Transfer member
(Figure 2)
1a-1d: Developer
2: Photoconductor belt
3: Intermediate transfer belt
4: Transfer roller
5: Fixing roller
6: Transfer member

Claims (10)

There are four color development sections of yellow, cyan, magenta, and black, and each of them forms an electrostatic latent image on the electrostatic latent image carrier, which is developed with color toner, and the electrostatic latent image carrier After the primary transfer of the upper toner image to the intermediate transfer member, the toner image on the intermediate transfer member is secondarily transferred (collectively transferred) to the transfer member and then the toner on the transfer member is fixed. In the method, (a) the full-color toner contains at least a binder resin, a colorant, and a fluidizing imparting agent, and the cyan, magenta, and black toner having the earliest development order is A, the second toner is B, When the toner with the slowest development order is C, the addition amount of the fluidizing agent is A> B> C, and (b) the absolute value of the toner charge amount at this time | Q _A / M |, | Q _B / M |, | Q _C / M | is | Q _A / M | >> Q _B / M | >> Q _C / M |, (c) 15 μC / g <| Q _A / D | <40 μC / g, and (d) secondary transfer is performed by transferring a toner image to a transfer member by bringing a transfer device to which a transfer bias is applied into contact at 3 g / cm or more. Forming method. It has four color development sections of yellow, cyan, magenta, and black, each of which forms an electrostatic latent image on the electrostatic latent image carrier, which is developed with color toner, and the electrostatic latent image carrier After the primary transfer of the upper toner image to the intermediate transfer member, the toner image on the intermediate transfer member is secondarily transferred (collectively transferred) to the transfer member, and then the toner on the transfer member is fixed. In the method, (a) the full-color toner contains at least a binder resin, a coloring material, and a fluidizing agent, and the yellow toner, the cyan toner, the magenta toner, and the black toner having the fastest developing order are A and the second toner is used. B, where C is the third toner, and D is the toner with the slowest development order, the addition amount of the fluidizing agent is A> B> C> D, and (b) the absolute toner charge amount at this time Value | Q _A / M |, | Q _B / M |, | Q _C / M |, | Q _D / M | is | Q _A / M | >> Q _B / M | >> Q _C / M | >> Q _D / M |, (c) 15 μC / g <| Q _A / D | <40 μC / g, and (d) secondary transfer is performed by transferring a toner image to a transfer member by bringing a transfer device to which a transfer bias is applied into contact at 3 g / cm or more. Forming method. The image forming method according to claim 1, wherein the intermediate transfer member is an intermediate transfer belt. The image forming method according to claim 1, wherein the electrostatic latent image carrier is a photosensitive belt. The image forming method according to claim 1, wherein the intermediate transfer member is obtained by applying a small amount of zinc stearate. It has four color development sections of yellow, cyan, magenta, and black, each of which forms an electrostatic latent image on the electrostatic latent image carrier, which is developed with color toner, and the electrostatic latent image carrier A full color system in which the toner image on the intermediate transfer member is subjected to primary transfer to the intermediate transfer member, then the toner image on the intermediate transfer member is secondarily transferred (collectively transferred) to the transfer member, and then the toner on the transfer member is fixed. In the image forming apparatus, (a) the full-color toner contains at least a binder resin, a colorant, and a fluidizing imparting agent. Among the cyan, magenta, and black, the toner with the fastest development order is A, and the second toner is used. B, where C represents the toner with the slowest development order, the amount of fluidizing agent added is A> B> C, and (b) the absolute value of the toner charge amount at this time | Q _A / M |, | Q _B / M |, | Q _C / M | is | Q _A / M | >> Q _B / M | >> Q _C / M |, (c) 15 μC / g <| Q _A / M | <40 μC / g, and (d) secondary transfer is a system in which a transfer device to which a transfer bias is applied is brought into contact at 3 g / cm or more to transfer a toner image to a transfer member. An image forming apparatus. It has four color development sections of yellow, cyan, magenta, and black, each of which forms an electrostatic latent image on the electrostatic latent image carrier, which is developed with color toner, and the electrostatic latent image carrier A full color system in which the toner image on the intermediate transfer member is subjected to primary transfer to the intermediate transfer member, then the toner image on the intermediate transfer member is secondarily transferred (collectively transferred) to the transfer member, and then the toner on the transfer member is fixed. In the image forming apparatus, (a) the full-color toner contains at least a binder resin, a colorant, and a fluidizing imparting agent. Among yellow, cyan, magenta, and black, the toner with the earliest development order is A and the second one. When the toner is B, the third toner is C, and the toner with the slowest development order is D, the addition amount of the fluidizing agent is A> B> C> D, and (b) the toner charge amount at this time Extinction Counter value | Q _A / M |, | Q _B / M |, | Q _C / M |, | Q _D / M | is | Q _A / M | >> Q _B / M | >> Q _C / M | >> Q _D / M |, (c) 15 μC / g <| Q _A / M | <40 μC / g, and (d) secondary transfer is a system in which a transfer device to which a transfer bias is applied is brought into contact at 3 g / cm or more to transfer a toner image to a transfer member. An image forming apparatus. The image forming apparatus according to claim 6, wherein the intermediate transfer member is an intermediate transfer belt. The image forming apparatus according to claim 6, wherein the electrostatic latent image carrier is a photosensitive belt. The image forming apparatus according to claim 6, wherein the intermediate transfer member is obtained by applying a small amount of zinc stearate.

Images