JP2018054705A - Toner for electrostatic charge image development, electrostatic charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development that reduces the generation of color streaks.SOLUTION: A toner for electrostatic charge image development contains: toner particles; and complex particles that contains lubricant particles and reversed polarity particles having chargeability of a reversed polarity to that of the lubricant particles, where the reversed polarity particles adhere to the surfaces of the lubricant particles to form a complex body. In the complex particles, the number ratio (C:C) between the positively charged complex particles (C) and the negatively charged complex particles (C)is in a range of 30:70 to 70:30.SELECTED DRAWING: None

Description

  The present invention relates to an electrostatic charge image developing toner, an electrostatic charge image developer, a toner cartridge, a process cartridge, an image forming apparatus, and an image forming method.

  In electrophotographic image formation, a toner is used as an image forming material. For example, a toner containing toner particles containing a binder resin and a colorant and an external additive externally added to the toner particles is used. Many are used.

  For example, Patent Document 1 discloses that “a toner base particle containing a binder resin, a colorant and a release agent, and an external additive, the external additive containing zinc-containing particles, The number of the free zinc-containing particles is 0.2 to 1.0% by number, the number average particle size of the free zinc-containing particles is 1.0 to 3.0 μm, and the free zinc-containing particles An electrostatic charge image developing toner having an average circularity of 0.2 or more and 0.6 or less is disclosed.

  Patent Document 2 states that “a toner for developing an electrostatic charge image containing toner particles and an external additive, wherein the external additive is formed on the surface of the core material particles in supercritical carbon dioxide. An electrostatic charge image developing toner "is disclosed which is an external additive having a coating layer containing.

  Patent Document 3 discloses that “a toner base containing a binder resin having an acid value of 1 to 70 mgKOH / g, a wax having an iodine value of 25 or less and a saponification value of 30 to 300, a fatty acid and a fatty acid metal. Toner containing inorganic fine powder treated with salt "is disclosed.

  Patent Document 4 includes “colored particles containing a binder resin and a colorant, and composite particles containing lubricant particles and abrasive particles, at least a part of the abrasive particles being exposed on the surface”. An electrostatic latent image developing toner "is disclosed.

JP 2010-185999 A JP 2014-134594 A JP 2003-84486 A JP 2008-145749 A

Conventionally, when an electrostatic charge image developing toner containing toner particles and lubricant particles is used, an image in which an image portion and a non-image portion are clearly separated is continuously formed and then left in a low temperature environment. When an image is formed again, color streaks (horizontal streaks) may occur in a direction perpendicular to the recording medium conveyance direction.
Accordingly, the first problem of the present invention is that, instead of or in addition to the lubricant particles, reverse polarity particles having a chargeability opposite to that of the lubricant particles are fixed on the surface of the lubricant particles, and the composite is formed. The number ratio (C ₊ / C ₋ ) of the composite particles [C ₊ ] to the negatively charged composite particles [C ₋ ] is less than 30/70. It is an object to provide a toner for developing an electrostatic charge image in which the generation of the color streaks is suppressed as compared with the case where it exceeds 70/30.
In addition, the second problem of the present invention is that, instead of or in addition to the lubricant particles, reverse polarity particles having a chargeability opposite to that of the lubricant particles are fixed to the surface of the lubricant particles to form a composite. Composite particles [C _M ] in which the coverage of the composite particles [C _L ] is 40% or more using the composite particles formed, and the coverage of the lubricant particles by the reverse polarity particles is less than 40%. It is an object to provide a toner for developing an electrostatic image in which the generation of the color streaks is suppressed as compared with the case where the number ratio (C _L / C _M ) is less than 30/70 or more than 70/30.

  The above problem is solved by the following means. That is,

The invention according to claim 1
Toner particles,
Lubricant particles, and composite particles containing reverse polar particles having a charge opposite to that of the lubricant particles, and the reverse polar particles fixed to the surface of the lubricant particles to form a composite,
Including
Among the composite particles, the number ratio (C ₊ : C ₋ ) of the composite particles [C ₊ ] that are positively charged and the composite particles [C ₋ ] that are negatively charged is 30:70 to 70: An electrostatic charge image developing toner in the range of 30.

The invention according to claim 2
Toner particles,
Lubricant particles, and composite particles containing reverse polar particles having a charge opposite to that of the lubricant particles, and the reverse polar particles fixed to the surface of the lubricant particles to form a composite,
Including
Wherein among the composite particles, the lubricant composite particles [C _M the composite particle coating ratio is less than 40% by reverse polarity particles [C _L] and the coverage of the surface is 40% or more of the particles The toner for developing an electrostatic charge image has a number ratio (C _L : C _M ) to the range of 30:70 to 70:30.

The invention according to claim 3
The electrostatic charge image developing toner according to claim 2, wherein in the composite particles, an average coverage by the reverse polarity particles on the surface of the lubricant particles is 20% or more and 60% or less.

The invention according to claim 4
When the distribution of the number of coverages in the composite particles is graphed (horizontal axis = coverage, vertical axis = number), there is a peak in both the area where the coverage is less than 40% and the area where the coverage is 40% or more. The toner for developing an electrostatic charge image according to claim 2, which is present.

The invention according to claim 5
In the composite particles, the ratio of the composite particles satisfying the following formula (1) to the number of the toner particles is 0.006% by number or more and the composite particles satisfying the following formula (2) are satisfied. 5. The electrostatic image developing toner according to claim 1, wherein a ratio with respect to the number of the toner particles is 0.001% by number or less.
Formula (1) 1 μm ≦ R _C ≦ (0.45 × R _TN )
Formula (2) R _C <1 μm
(In the above formulas (1) and (2), R _TN represents the volume average particle size (μm) of the toner particles, and R _C represents the particle size (μm) of the composite particles.)

The invention according to claim 6
6. The electrostatic image developing toner according to claim 1, wherein the lubricant particles are zinc stearate particles, and the reverse polarity particles are silica particles. 7.

The invention according to claim 7 provides:
An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1.

The invention according to claim 8 provides:
Containing the toner for developing an electrostatic charge image according to any one of claims 1 to 6,
A toner cartridge to be attached to and detached from the image forming apparatus.

The invention according to claim 9 is:
A developing means for containing the electrostatic charge image developer according to claim 7 and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer,
A process cartridge attached to and detached from the image forming apparatus.

The invention according to claim 10 is:
An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
Development means for containing the electrostatic image developer according to claim 7 and developing the electrostatic image formed on the surface of the image carrier as a toner image by the electrostatic image developer;
Transfer means for transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
Fixing means for fixing the toner image transferred to the surface of the recording medium;
Cleaning means for cleaning the surface of the image carrier by bringing a cleaning blade into contact with the image carrier;
An image forming apparatus comprising:

The invention according to claim 11 is:
A charging step for charging the surface of the image carrier;
An electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image carrier;
A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer according to claim 7;
A transfer step of transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
A fixing step of fixing the toner image transferred to the surface of the recording medium;
A cleaning step of cleaning the surface of the image carrier by bringing a cleaning blade into contact with the image carrier;
An image forming method comprising:

According to the first or sixth aspect of the invention, the composite particles in which the toner particles and the opposite polarity particles having the opposite polarity to the lubricant particles are fixed to the surface of the lubricant particles to form a complex. And the number ratio (C ₊ / C ₋ ) of the positively chargeable composite particles [C ₊ ] to the negatively charged composite particles [C ₋ ] is less than 30/70, or 70/30 Compared to the case of exceeding, the direction perpendicular to the conveyance direction of the recording medium when an image having a clearly separated image portion and non-image portion is continuously formed and then left to stand and then formed again in a low temperature environment Thus, a toner for developing an electrostatic image in which color streaks occurring in the toner are suppressed is provided.
According to the invention according to claim 2 or 6, the composite particles in which the toner particles and the opposite polarity particles having the opposite polarity to the lubricant particles are fixed to the surface of the lubricant particles to form a complex. And the ratio of the number of the composite particles [C _L ] of the surface of the lubricant particles to the composite particles [C _M ] having a coverage ratio of less than 40% with respect to the composite particles [C _M ] of 40% or more. Compared with the case where (C _L / C _M ) is less than 30/70 or more than 70/30, an image in which the image area and the non-image area are clearly separated is continuously formed and then left to stand in a low-temperature environment. Thus, there is provided an electrostatic image developing toner that suppresses color streaks that occur in a direction perpendicular to the conveyance direction of the recording medium when an image is formed again.
According to the third aspect of the present invention, the image area and the non-image area are clearly separated compared to the case where the average coverage by the reverse polarity particles on the surface of the lubricant particles is less than 20% or more than 60%. Provided is a toner for developing an electrostatic charge image in which color streaks that occur in a direction perpendicular to the conveyance direction of a recording medium when an image is continuously formed and then left standing and then formed again in a low temperature environment are suppressed.
According to the fourth aspect of the present invention, there is only one peak when the distribution of the number of coverages by the reverse polarity particles on the surface of the lubricant particles is graphed (horizontal axis = coverage, vertical axis = number). Compared to the case, when an image with a clear separation between the image area and the non-image area is formed continuously and then left standing, the image is formed again in a low-temperature environment, and the color generated in the direction perpendicular to the conveyance direction of the recording medium Provided is a toner for developing an electrostatic image in which streaks are suppressed.
According to the fifth aspect of the present invention, compared to the case where the ratio of the composite particles satisfying the condition of the expression (1) to the number of toner particles is less than 0.006% by number, the image portion and the non-image portion are reduced. An electrostatic image developing toner that suppresses color streaks that occur in a direction perpendicular to the conveyance direction of a recording medium when a clearly separated image is continuously formed and then left standing and then formed again in a low temperature environment. Provided.

According to the invention according to claim 7, 8, 9, 10, or 11, the composite of the toner particles and the lubricant particles fixed on the surface of the lubricant particles is fixed to the opposite polarity particles having the opposite polarity to the lubricant particles. The number ratio (C ₊ / C ₋ ) of the positively chargeable composite particles [C ₊ ] to the negatively charged composite particles [C ₋ ] is 30/70. Composite particles [C _L ] having a coverage of less than 40% or more and less than 40/30, and the coverage of the lubricant particles by the reverse polarity particles being less than 40% Compared with the case where the number ratio (C _L / C _M ) to [C _M ] is less than 30/70 or more than 70/30, an image in which the image portion and the non-image portion are clearly separated is continuously formed. After that, when the image is formed again in a low temperature environment after being left standing, An electrostatic charge image developer, a toner cartridge, a process cartridge, an image forming apparatus, or an image forming method in which color streaks occurring in the intersecting direction are suppressed is provided.

It is an image which shows an example of the composite particle used for this implementation system. It is an image which shows an example of the composite particle used for this implementation system. It is the schematic for demonstrating the preferable particle size of the composite particle in this implementation type | system | group. It is a figure explaining the state of a screw about an example of a screw extruder used for manufacture of toner concerning this embodiment. 1 is a schematic configuration diagram illustrating an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows the process cartridge which concerns on this embodiment.

  Hereinafter, the present invention will be described in detail with reference to an exemplary embodiment.

<Toner for electrostatic image development>
The toner for developing an electrostatic charge image (hereinafter, also simply referred to as “toner”) according to the present embodiment includes toner particles and composite particles. The composite particle includes a lubricant particle and a reverse polarity particle having a polarity opposite to that of the lubricant particle, and the reverse polarity particle is fixed to the surface of the lubricant particle to form a composite. Make up the body.

The toner according to the first embodiment of the present embodiment includes a composite particle [C ₊ ] that is positively charged and a composite particle [C ₋ ] that is negatively charged among the composite particles. The number ratio (C ₊ : C ₋ ) is in the range of 30:70 to 70:30.

In addition, the toner according to the second embodiment of the present embodiment is a composite particle [C _L ] in which the coverage of the lubricant particles on the surface of the lubricant particle with the reverse polarity particle is less than 40%. And the number ratio (C _L : C _M ) of the composite particles [C _M ] having a coverage of 40% or more is in the range of 30:70 to 70:30.

Here, when an image in which the image portion and the non-image portion are clearly formed is continuously formed, and then left to stand, the image is formed again in a low temperature environment, and then in a direction orthogonal to the conveyance direction of the recording medium. Color streaks (horizontal streaks) may occur. However, according to the toner according to the first embodiment, the generation of the color stripe (horizontal stripe) is suppressed. In addition, according to the toner according to the second embodiment, the generation of the color stripe (horizontal stripe) is suppressed.
The reason is estimated as follows.

Conventionally, in electrophotographic image formation, a cleaning means using a cleaning blade has been used for the purpose of removing transfer residual toner on the surface of an image carrier. In addition, lubricant particles are added to the toner from the viewpoint of suppressing wear of the image carrier due to contact with the cleaning blade.
However, when toner containing toner particles and lubricant particles is used, an image in which an image portion and a non-image portion are clearly separated (for example, a solid image portion having an image density of 100% and a non-image portion having an image density of 0%) Are continuously formed (for example, 1000 images continuously), and then left (for example, left overnight), and then a low-temperature environment (for example, a winter morning) is exemplified. When an image is formed under (environment), color streaks (lateral streaks) may occur in a direction orthogonal to the recording medium conveyance direction.

  The cause of the occurrence of the color streaks (lateral streaks) is considered to be due to the chargeability of the lubricant particles. For example, when toner particles are negative (minus) charged, and positively charged particles such as fatty acid metal salts are used as the lubricant particles, the lubricant particles are supplied to the surface of the image carrier. Is supplied more to the non-image area. Further, when negatively charged particles are used as the lubricant particles, the lubricant particles are supplied more to the image portion. As a result, when an image in which the image portion and the non-image portion are clearly separated is continuously formed, the lubricant particles are present only in one of the region corresponding to the image portion of the image carrier or the region corresponding to the non-image portion. A large amount is present, and the lubricant particles are not present or only in a small amount in the other region. Then, after being left as it is, when an image is formed under a low temperature environment, that is, an environment where the hardness of the cleaning blade becomes harder and the contact pressure becomes higher, there is no lubricant particle in the other region or Since there is only a small amount, the frictional force with the cleaning blade in this region increases. As the frictional force increases, vibration of the cleaning blade called chattering (that is, a phenomenon in which the cleaning blade is repeatedly pulled in the driving direction of the image carrier by the frictional force and returns to the original position) occurs, and the cleaning blade holds the image. When the body is pulled in the driving direction, the cleaning performance is lowered, and toner or the like slips through. This slipped toner or the like is considered to be generated as a color stripe (horizontal stripe) in the image.

On the other hand, in the present embodiment, the composite particles include composite particles in which reverse-polar particles having a chargeability opposite to that of the lubricant particles are fixed to the surfaces of the lubricant particles to form a composite. In the toner according to the first embodiment, among the composite particles, the number ratio (C) of the composite particles [C ₊ ] that are positively charged and the composite particles [C ₋ ] that are negatively charged. ₊ : C ₋ ) is the above range.
The fact that the number ratio (C ₊ : C ₋ ) satisfies the above range means that composite particles that are easily supplied to the image part and composite particles that are easily supplied to the non-image part are mixed, and which composite It can be said that the particle is also an indicator that the content is not small. Therefore, even when an image in which an image portion and a non-image portion are clearly formed is continuously formed, by using the toner according to the first embodiment, an area corresponding to the image portion of the image carrier and The composite particles are easily supplied to both of the areas corresponding to the non-image portions. As a result, even when the above-mentioned images are continuously formed and left standing and then formed again in a low-temperature environment, vibration of the cleaning blade called chattering is suppressed, toner slipping is reduced, and color streaks in the image are reduced. It is considered that the occurrence of (horizontal stripes) is suppressed.

Further, in the toner according to the second embodiment, among the composite particles, composite particles [C _L ] in which the coverage by the reverse polarity particles on the surface of the lubricant particles is less than 40% and the coverage is 40. The number ratio (C _L : C _M ) to the composite particles [C _M ] that is at least% is in the above range.
The fact that the number ratio (C _L : C _M ) satisfies the above range means that the composite particles in which the surface of the lubricant particles is covered with a relatively small amount of the reverse polarity particles and the relatively large amount of the reverse polarity particles are included. It represents that the composite particles that are covered are mixed, that is, the composite particles that are relatively positively charged and the composite particles that are negatively charged are mixed. Moreover, it can be said that both of these composite particles are an indicator that the content is not small. Therefore, even when an image in which the image portion and the non-image portion are clearly separated is continuously formed, by using the toner according to the second embodiment, an area corresponding to the image portion of the image carrier and The composite particles are easily supplied to both of the areas corresponding to the non-image portions. As a result, even when the above-mentioned images are continuously formed and left standing and then formed again in a low-temperature environment, vibration of the cleaning blade called chattering is suppressed, toner slipping is reduced, and color streaks in the image are reduced. It is considered that the occurrence of (horizontal stripes) is suppressed.

  Hereinafter, details of the toner according to the exemplary embodiment will be described.

  The toner according to the exemplary embodiment includes toner particles and composite particles.

(Composite particle)
The composite particle contains a lubricant particle and a reverse electrode particle having a chargeability opposite to that of the lubricant particle, and the reverse electrode particle is fixed to the surface of the lubricant particle to form a composite. .

Here, “adhesion” means that the opposite polarity particles are attached to the surface of the lubricant particles so that they are not easily detached. Specifically, even after the following ultrasonic treatment is performed. It represents that reverse polarity particles are present on the surface of the lubricant particles.
-Sonication-
When added in the toner, first, 4 g of the toner is added to 100 mL of a 0.2 mass% aqueous solution of Triton solution (polyoxyethylene octylphenyl ether, manufactured by Wako Pure Chemical Industries, Ltd.), under the condition of 100 rpm. Stir for 10 minutes to desorb the composite particles from the toner particles and other external additives. This is treated with a centrifuge (trade name: M201-IVD, manufactured by Sakuma Seisakusho Co., Ltd.) for 2 minutes at 3000 rpm, and the toner particles, other external additives, etc. are separated and filtered to form composite particles. Get a sample.
Next, 4 g of the composite particle sample was added to 100 mL of a 0.2 mass% aqueous solution of Triton solution (polyoxyethylene octylphenyl ether, manufactured by Wako Pure Chemical Industries, Ltd.), dispersed by stirring, and then subjected to ultrasonic waves. Using an apparatus (manufactured by Nippon Seiki Seisakusho, trade name: US-300TCVP), ultrasonic vibration with an output of 20 W and a frequency of 20 kHz is applied for 10 minutes. This was treated with a centrifuge (trade name: M201-IVD, manufactured by Sakuma Seisakusho Co., Ltd.) for 30 minutes under the condition of 10,000 rpm, and the reversed polar particles separated by ultrasonic vibration were separated and filtered to obtain a composite. Get particles.
The obtained composite particles are observed with a scanning electron microscope (SEM, manufactured by Hitachi, Ltd .: S-4100), and the reversed polar particles present on the surface of the lubricant particles are regarded as fixed reversed polar particles.

-Measurement method of coverage-
The “coverage” of the composite particles (coverage by the reversed polar particles fixed on the surface of the lubricant particles) is determined by performing a scanning electron microscope (SEM, manufactured by Hitachi, Ltd.) after performing the above ultrasonic treatment. : From the image photographed in S-4100), the area of the composite particles on the surface of the lubricant particles where the reverse polar particles are not attached and the area of the reverse polar particles attached to the lubricant particles are measured, This is done by calculating the ratio of coating from here.
The average coverage is measured by measuring the coverage of the arbitrary 100 composite particles by the above method and calculating the average value.

First embodiment / number ratio (C ₊ : C ₋ )
In the toner according to the first embodiment, among the composite particles, the number ratio (C ₊ : C) of the composite particles [C ₊ ] that are positively charged and the composite particles [C ₋ ] that are negatively charged. _- ) Is in the range of 30:70 to 70:30. When the number ratio (C ₊ : C ₋ ) is in the above range, when an image in which the image area and the non-image area are clearly separated is continuously formed and then left standing, the image is formed again in a low temperature environment In addition, color streaks (lateral streaks) that occur in a direction perpendicular to the conveyance direction of the recording medium are suppressed.
The number ratio (C ₊ : C ₋ ) is more preferably in the range of 40:60 to 60:40, and still more preferably in the range of 45:55 to 55:45.

  “Negative chargeability” and “positive chargeability” mean whether the composite particles are charged negatively (−) or positively (+) when the toner is charged in the developing device. To do.

Here, a method of calculating the number ratio (C ₊ : C ₋ ) of the composite particles [C ₊ ] having positive chargeability and the composite particles [C ₋ ] having negative chargeability will be described.
The composite particles (2.0 g) and the carrier (28.0 g) were placed in a 60 mL wide-mouth stopper bottle and stirred for 2 minutes. The contents were connected to a high voltage power source (trade name: FLUKE415B, manufactured by FLUKE) and a voltage of 200 V was applied. It passes between a pair of applied electrode plates (steel, clearance 3 mm). After removing the electrode plate and removing the carrier adhering by air blow, the surface adhering material of each of the positive electrode plate and the negative electrode plate is magnified using a scanning electron microscope (SEM, manufactured by Hitachi, Ltd .: S-4100). Taking 10 fields of view at 1000 times, counting the number of composite particles, the number of composite particles on the negative electrode plate as [C ₊ ], and the number of composite particles on the positive electrode plate as [C ₋ ] The ratio (C ₊ : C ₋ ) is calculated.

The method for controlling the number ratio (C ₊ : C ₋ ) in the composite particles to the above range is not particularly limited, but the coverage by the reverse polar particles fixed on the surface of the lubricant particles is not limited. A method of adjusting the distribution is mentioned. In other words, the surface of the lubricant particles is in a state where composite particles covered with more reverse polar particles and composite particles covered with fewer reverse polar particles are mixed, and the mixing ratio is adjusted. The number ratio (C ₊ : C ₋ ) is controlled within the above range.
In particular, the number ratio (C C) of the composite particles [C _L ] having a coverage ratio of less than 40% with the opposite polar particles on the surface of the lubricant particles to the composite particles [C _M ] having a coverage ratio of 40% or more. _By setting _L : C _M ) within the above-described range (that is, a range satisfying the requirements of the toner according to the second embodiment), the number ratio (C ₊ : C ₋ ) can be easily controlled within the above range.

Second embodiment / number ratio (C _L : C _M )
In the toner according to the second embodiment, among the composite particles, composite particles [C _L ] in which the coverage by the opposite polarity particles fixed on the surface of the lubricant particles is less than 40% and the coverage is 40% or more. The number ratio (C _L : C _M ) to the composite particles [C _M ] is in the range of 30:70 to 70:30.
For example, FIG. 1A and FIG. 1B show images of composite particles in which silica particles, which are examples of reverse polarity particles, adhere to the surface of zinc stearate, which is an example of lubricant particles, to form a composite. 1A is an image of a composite particle having a coverage of 15% by silica particles, and FIG. 1B is an image of a composite particle having a coverage of 50% by silica particles.
When the number ratio (C _L : C _M ) is in the above range, an image in which the image portion and the non-image portion are clearly separated is continuously formed and then left to stand, and then the image is formed again in a low temperature environment In addition, color streaks (lateral streaks) that occur in a direction perpendicular to the conveyance direction of the recording medium are suppressed.
The number ratio (C _L : C _M ) is more preferably in the range of 40:60 to 60:40, and still more preferably in the range of 45:55 to 55:45.

In addition, the calculation of the number ratio (C _L : C _M ) between the composite particles [C _L ] having a coverage of less than 40% and the composite particles [C _M ] having a coverage of 40% or more is arbitrary. By measuring the coverage of 100 composite particles by the method described above, the number of composite particles having a coverage of less than 40% and the number of composite particles having a coverage of 40% or more are counted. Done.

A method for controlling the number ratio (C _L : C _M ) in the composite particles within the above range will be described.
First, the method of including the composite particles having the opposite polar particles fixed on the surface of the lubricant particles as an external additive in the toner is not particularly limited. For example, the composite particles are externally added to the toner particles. The previous lubricant particles and the reverse polarity particles are mixed in advance and agitated while applying a shearing force, and fixed, and the lubricant particles (composite particles) having the reverse polarity particles fixed on the surface are adhered to the toner particles. The method of external addition is mentioned as a preferable method.

Further, the method for controlling the number ratio (C _L : C _M ) within the above range is not particularly limited, and examples thereof include the following methods (1) and (2).
(1) Method of preparing and mixing two or more composite particles having different average coverage ratio First, lubricant particles and a relatively small amount of reverse polarity particles (adjusted so that the average coverage ratio is less than 40%) Are mixed and stirred while applying a shearing force to fix the opposite polarity particles, thereby preparing composite particles having an average coverage of less than 40%. Separately, the lubricant particles are mixed with a relatively large amount (adjusted so that the average coverage is 40% or more) of the reverse pole particles, and stirred while applying a shearing force. Composite particles having an average coverage of 40% or more are prepared by fixing the particles. A method of controlling the number ratio (C _L : C _M ) within the above range by adding both of these externally to the toner particles and adjusting the ratio of the addition of the two is given.
Note that the method is not limited to preparing two types of composite particles having different average coverage ratios as described above and externally adding them to toner particles, and preparing three or more types of composite particles having different average coverage ratios. The number ratio (C _L : C _M ) may be controlled within the above range by externally adding these to the toner particles and adjusting the addition ratio.

  According to the method of (1) above, in the number distribution of coverage in the composite particles, the composite particle having two or more peaks (maximum values), that is, the number distribution of the coverage in the composite particles is plotted (horizontal). Toner to which composite particles having a peak (maximum value) are externally added in both the area where the coverage is less than 40% and the area where the coverage is 40% or more when the axis = coverage and the ordinate = number) Can be made.

  Here, the configuration in which a peak (maximum value) exists in both the area where the coverage is less than 40% and the area where the coverage is 40% or more will be described in more detail. Usually, it is not easy to precisely control the distribution of coverage by the reverse polarity particles on the surface of the lubricant particles. Therefore, the “coverage number distribution” described in this specification refers to a case where a rough number distribution of the coverage is taken. For example, “distribution when the number (total number) is collected every 10% of coverage intervals” is expressed, that is, the coverage is 0% or more, less than 10%, 10% or more, less than 20%, 20% or more, less than 30%, 30% More than 40%, 40% or more, less than 50%, 50% or more, less than 60%, 60% or more, less than 70%, 70% or more, less than 80%, 80% or more, less than 90%, or 90% or more, less than 100%. When the number of composite particles that fall within the range is calculated and plotted on a graph (horizontal axis = coverage, vertical axis = number), the area of coverage less than 40% and the area of coverage greater than 40% In any case, there is a mode in which a peak (maximum value) exists.

  By making composite particles in which peaks exist in both the area with a coverage of less than 40% and the area with a coverage of 40% or more (that is, there are at least two peaks as a whole), there is only one peak as a whole. Compared to the case of non-existing composite particles, there are more composite particles that are easily supplied to the image area and more complex particles that are easily supplied to the non-image area. As a result, when an image in which the image area and the non-image area are clearly separated is continuously formed and then left to stand, and then the image is formed again in a low-temperature environment, the color generated in the direction orthogonal to the recording medium conveyance direction It is easier to suppress streaks (lateral streaks).

(2) Method of mixing all together Lubricant particles and reverse polarity particles are mixed and agitated and fixed while applying a shearing force. At that time, for example, by adjusting the following items, the number ratio (C _L : C A method of controlling _M ) within the above-mentioned range is mentioned. Then, the toner according to the exemplary embodiment is obtained by externally adding the composite particles having the adjusted number ratio (C _L : C _M ) to the toner particles.
・ Adjust the amount of reverse polarity particles with respect to the lubricant particles ・ Adjust the shearing force and stirring time during stirring ・ Add the lubricant particles in several increments and adjust the amount and number of the agents divided Do

The average coverage of the composite particles as a whole is preferably 20% or more and 60% or less, more preferably 23% or more and 57% or less, and further preferably 26% or more and 54% or less.
The average coverage in the entire composite particle is in the above range, so that the distribution of the coverage in the composite particle can be balanced, that is, the composite particle that is easily supplied to the image portion and the composite that is easily supplied to the non-image portion. Easy to balance with particles. As a result, color streaks appear in the direction perpendicular to the recording medium conveyance direction when an image with a clear separation between the image area and the non-image area is continuously formed and then left to stand and then formed again in a low temperature environment. (Horizontal stripes) can be more easily suppressed.

-Particle size of composite particles The composite particles preferably have a particle size of 1 µm or more from the viewpoint of suppressing slipping of the composite particles with the cleaning blade.

On the other hand, in this embodiment, in order to clean the residual toner remaining without being transferred to the surface on the downstream side (downstream side in the image carrier driving direction) from the contact position of the image carrier with the transfer unit, A cleaning blade is disposed on the surface of the holding body. In the region upstream of the contact portion of the cleaning blade with the image carrier (upstream in the image carrier driving direction), deposits of toner particles (so-called toner dams) are formed. On the contact portion side between the toner and the image carrier, a deposit (so-called external additive dam) is formed by an external additive having a smaller diameter than the toner particles. Due to the formation of both deposits, the cleaning by the cleaning blade is performed well. Therefore, the particle diameter of the composite particles is preferably such that it can easily enter the inner side (contact portion side) of the toner dam to form the external additive dam.
Specifically, assuming that the contact angle α between the cleaning blade and the image carrier is 45 °, for example, as shown in FIG. 2, the particle diameter of the composite particle C that can enter the contact portion side of the toner dam (2 × r) is 0.45 times or less than the particle size (2 × R) of the toner particles TN. Therefore, the particle diameter of the composite particles is preferably not more than “0.45 × R _TN ” (R _TN : volume average particle diameter of toner particles).

From the above points, from the viewpoint of improving the cleaning property, the ratio of the composite particles satisfying the condition of the following formula (1) to the number of toner particles is preferably 0.006 number% or more, more preferably 0.00. 010 number% or more.
Further, the upper limit is preferably 0.1% by number or less, more preferably 0.08% by number or less, because if the composite particles are excessive, the cleaning blade can easily pass through.
Formula (1) 1 μm ≦ R _C ≦ (0.45 × R _TN )
(In the above formula (1), R _TN represents the volume average particle size (μm) of the toner particles, and R _C represents the particle size (μm) of the composite particles.)

Further, from the viewpoint of suppressing slipping of the composite particles by the cleaning blade, the ratio of the composite particles satisfying the following formula (2) to the number of toner particles is preferably 0.001% by number or less, more The amount is preferably 0.0008% by number or less, and the smaller the amount, the more preferable.
Formula (2) R _C <1 μm
(In the above formula (2), R _C represents the particle size (μm) of the composite particles.)

The particle size of the composite particles (R _C (μm) / particle size of each composite particle) was determined by using a scanning electron microscope (SEM, ) Image taken with Hitachi, Ltd. (S-4100), this image is taken into an image analyzer (LUZEXIII, Nireco Corp.), the area of each particle is measured by image analysis of primary particles, and this area value The equivalent circle diameter is calculated from

A method for measuring the volume average particle diameter (R _TN (μm)) of the toner particles will be described later.

  The particle size of the composite particles can be controlled mainly by adjusting the particle size of the lubricant particles. It is also controlled by adjusting the particle size of the opposite polarity particles to be fixed.

  Next, the lubricant particles and the reverse polarity particles constituting the composite particles will be described.

Lubricant Particles As the composite particles, either negatively chargeable lubricant particles N or positively chargeable lubricant particles P may be used. Here, “negatively chargeable” and “positively chargeable” are negative (−) when the toner is charged in the case where the lubricant particles are present alone as a composite particle in the developing device. Means positively or positively (+).

Examples of the positively chargeable lubricant particles P include fatty acid metal salt particles. The fatty acid metal salt particle is a salt particle composed of a fatty acid and a metal.
The fatty acid may be either a saturated fatty acid or an unsaturated fatty acid. Examples of the fatty acid include fatty acids having 10 to 25 (preferably 12 to 22) carbon atoms. In addition, carbon number of a fatty acid contains carbon of a carboxy group.
Examples of the fatty acid include saturated fatty acids such as behenic acid, stearic acid, palmitic acid, myristic acid and lauric acid; and unsaturated fatty acids such as oleic acid, linoleic acid and ricinoleic acid. Among these fatty acids, stearic acid and lauric acid are preferable, and stearic acid is more preferable.
As the metal, a divalent metal is preferable. Examples of the metal include magnesium, calcium, aluminum, barium, and zinc. Among these, the metal is preferably zinc.

Examples of the fatty acid metal salt particles include aluminum stearate, calcium stearate, potassium stearate, magnesium stearate, barium stearate, lithium stearate, zinc stearate, copper stearate, lead stearate, nickel stearate, stearic acid. Metal salts of stearic acid such as strontium, cobalt stearate, sodium stearate; metal salts of palmitic acid such as zinc palmitate, cobalt palmitate, copper palmitate, magnesium palmitate, aluminum palmitate, calcium palmitate; lauric acid Metal salts of lauric acid such as zinc, manganese laurate, calcium laurate, iron laurate, magnesium laurate, aluminum laurate; zinc oleate, olei Metal salts of oleic acid such as manganese acid, iron oleate, aluminum oleate, copper oleate, magnesium oleate, calcium oleate; metal salts of linoleic acid such as zinc linoleate, cobalt linoleate, calcium linoleate; ricinol Examples of such particles include metal salts of ricinoleic acid such as zinc acid and aluminum ricinoleate.
Among the fatty acid metal salt particles, metal particles of stearic acid or metal salts of lauric acid are preferable, zinc stearate or zinc laurate particles are more preferable, and zinc stearate particles are more preferable.

The average particle size of the positively chargeable lubricant particles P is preferably from 0.5 μm to 3.0 μm, more preferably from 0.6 μm to 2.9 μm, and even more preferably from 0.7 μm to 2. 85 μm or less.
In addition, the measurement of the average particle diameter of lubricant particles is performed according to the measurement method for inorganic particles described later.

Examples of the negatively chargeable lubricant particles N include fluorine resin particles, silicon resin, inorganic particles, and wax resin particles.
Examples of the fluororesin particles include polytetrafluoroethylene (PTFE, “tetrafluoroethylene resin”), perfluoroalkoxy fluororesin, polychlorotrifluoroethylene, polyvinylidene fluoride, polydichlorodifluoroethylene, tetrafluoroethylene-per Fluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-perfluoroalkoxy Examples thereof include particles such as an ethylene copolymer.
Among these, polytetrafluoroethylene (PTFE) is preferable.

The average particle size of the negatively chargeable lubricant particles N is preferably from 0.5 μm to 3.0 μm, more preferably from 0.6 μm to 2.9 μm, still more preferably from 0.7 μm to 2. 85 μm or less.
In addition, the measurement of the average particle diameter of lubricant particles is performed according to the measurement method for inorganic particles described later.

・ Reverse Polarized Particles As the reversed polar particles, charged particles having the opposite polarity to the lubricant particles used are used.
Examples of the negatively charged reverse electrode particles include inorganic particles. As the inorganic particles, SiO ₂ (silica particles), TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO _{2, CaO · SiO 2, K} 2 O · (TiO 2) n, Al 2 O 3 · 2SiO 2, CaCO 3, MgCO 3, BaSO 4, MgSO 4 , and the like.
Among these, silica particles are more preferable.

The silica particles may be silica, that is, particles containing SiO ₂ as a main component, and may be crystalline or amorphous. The silica particles may be particles produced from a silicon compound such as water glass or alkoxysilane, or particles obtained by pulverizing quartz. Specifically, silica particles Examples thereof include sol-gel silica particles, aqueous colloidal silica particles, alcoholic silica particles, fumed silica particles obtained by a gas phase method, and fused silica particles. Among them, as the silica particles, sol-gel silica particles are preferable from the viewpoint of satisfying the following characteristics.

The silica particles are preferably monodispersed and spherical. The monodispersed spherical silica particles are dispersed in a nearly uniform state on the surface of the lubricant particles, and a stable chargeability can be obtained.
Here, the definition of monodispersion can be discussed by the standard deviation with respect to the average particle diameter including aggregates, and the standard deviation is preferably a volume average particle diameter D50 × 0.22 or less. Further, as the definition of the spherical shape, it can be discussed by the average circularity described later.

  The average particle size of the inorganic particles (particularly silica particles) is preferably 8 nm or more and 120 nm or less, more preferably 10 nm or more and 110 nm or less, and further preferably 15 nm or more and 100 nm or less.

The average particle diameter of inorganic particles (particularly silica particles) is measured by the following method.
The primary particles of the inorganic particles are observed with a scanning electron microscope SEM (Scanning Electron Microscope) device (manufactured by Hitachi, Ltd .: S-4100) to take an image, and this image is taken as an image analysis device (LUZEXIII, (stock) ) (Manufactured by Nireco), the area of each particle is measured by image analysis of primary particles, and the equivalent circle diameter is calculated from the area value. The calculation of the equivalent circle diameter is performed for 100 inorganic particles. The 50% diameter (D50) in the volume-based cumulative frequency of the obtained equivalent circle diameter is defined as the average primary particle diameter (average equivalent circle diameter D50) of the inorganic particles. Note that the magnification of the electron microscope is adjusted so that about 10 to 50 inorganic particles are captured in one field of view, and the equivalent circle diameter of the primary particles is obtained by observing a plurality of fields of view.

It is preferable that the surface of the inorganic particles mentioned as the reverse electrode particles is subjected to a hydrophobic treatment. The hydrophobic treatment is performed, for example, by immersing inorganic particles in a hydrophobic treatment agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, and aluminum coupling agents. These may be used individually by 1 type and may use 2 or more types together.
The amount of the hydrophobizing agent is usually 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic particles, for example.

Examples of the positively charged reverse polarity particles include silica particles treated with a specific surface treatment agent.
The silica particles may be silica, that is, particles containing SiO ₂ as a main component, and may be crystalline or amorphous. Moreover, as a silica particle, the particle | grains manufactured from silicon compounds, such as water glass and alkoxysilane, may be sufficient, and the particle | grains obtained by grind | pulverizing quartz may be sufficient.
Specifically, examples of the silica particles include sol-gel silica particles, aqueous colloidal silica particles, alcoholic silica particles, fumed silica particles obtained by a gas phase method, and fused silica particles. Among them, as the silica particles, sol-gel silica particles are preferable from the viewpoint of satisfying the following characteristics.

  The silica particles are preferably monodispersed and spherical. The monodispersed spherical silica particles are dispersed in a nearly uniform state on the surface of the lubricant particles, and a stable chargeability can be obtained. Here, the definition of monodispersion and the definition of sphere are as described above, and it is preferable that the volume average particle diameter D50 × 0.22 or less as a standard deviation.

Specific surface treatment agents include hexamethyldisilazane, polydimethylsiloxane, octyltriethoxysilane, and the like.
Of these, hexamethyltydrazan is more preferable.

The average particle diameter of the positively charged reverse polarity particles is preferably 8 nm or more and 120 nm or less, more preferably 10 nm or more and 110 nm or less, and further preferably 15 nm or more and 100 nm or less.
In addition, the measurement of the said average particle diameter is performed according to the measuring method in the said inorganic particle.

-Content The content of the composite particles is 0.8% by mass or more and 2.0% by mass or less based on the amount of toner particles from the viewpoint of ensuring lubricity and suppressing filming on the image carrier. It is preferably 0.9% by mass or more and 1.9% by mass or less, more preferably 1.0% by mass or more and 1.8% by mass or less.

(Toner particles)
The toner particles include, for example, a binder resin and, if necessary, a colorant, a release agent, and other additives.

-Binder resin-
Examples of the binder resin include styrenes (eg, styrene, parachlorostyrene, α-methylstyrene, etc.), (meth) acrylic acid esters (eg, methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic acid). n-butyl, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (for example, acrylonitrile, Methacrylonitrile, etc.), vinyl ethers (eg, vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (eg, ethylene, propylene, etc.) Emissions, a homopolymer of a monomer such as butadiene) and the like, or a vinyl-based resin composed of these monomers with two or more combinations copolymer.
As the binder resin, for example, epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, non-vinyl resin such as modified rosin, a mixture of these with the vinyl resin, or these Examples also include a graft polymer obtained by polymerizing a vinyl monomer in the coexistence.
These binder resins may be used alone or in combination of two or more.

A polyester resin is suitable as the binder resin.
Examples of the polyester resin include known amorphous polyester resins. A polyester resin may use a crystalline polyester resin together with an amorphous polyester resin. However, the crystalline polyester resin is preferably used in the range of 2 mass% to 40 mass% (preferably 2 mass% to 20 mass%) with respect to the total binder resin.

The “crystallinity” of the resin means that it has a clear endothermic peak in differential scanning calorimetry (DSC) rather than a stepwise endothermic amount change. Specifically, the temperature rise rate is 10 (° C. / Min) indicates that the half-value width of the endothermic peak is 10 ° C. or less.
On the other hand, “amorphous” of the resin means that the half width exceeds 10 ° C., shows a stepwise endothermic change, or does not show a clear endothermic peak.

-Amorphous polyester resin As an amorphous polyester resin, the condensation polymer of polyhydric carboxylic acid and polyhydric alcohol is mentioned, for example. In addition, as an amorphous polyester resin, a commercial item may be used and what was synthesize | combined may be used.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (eg, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid, etc.) Alicyclic dicarboxylic acids (for example, cyclohexanedicarboxylic acid), aromatic dicarboxylic acids (for example, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), their anhydrides, or lower (for example, having 1 or more carbon atoms) 5 or less) alkyl esters. Among these, as polyvalent carboxylic acid, aromatic dicarboxylic acid is preferable, for example.
The polyvalent carboxylic acid may be used in combination with a dicarboxylic acid or a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, having 1 to 5 carbon atoms) alkyl esters.
Polyvalent carboxylic acid may be used individually by 1 type, and may use 2 or more types together.

Examples of the polyhydric alcohol include aliphatic diols (for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (for example, cyclohexanediol, cyclohexanedimethanol, Hydrogenated bisphenol A, etc.) and aromatic diols (for example, ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc.). Among these, as the polyhydric alcohol, for example, aromatic diols and alicyclic diols are preferable, and aromatic diols are more preferable.
As the polyhydric alcohol, a trihydric or higher polyhydric alcohol having a crosslinked structure or a branched structure may be used together with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
A polyhydric alcohol may be used individually by 1 type, and may use 2 or more types together.

The glass transition temperature (Tg) of the amorphous polyester resin is preferably 50 ° C. or higher and 80 ° C. or lower, and more preferably 50 ° C. or higher and 65 ° C. or lower.
The glass transition temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC), and more specifically described in the method for determining the glass transition temperature in JIS K 7121-1987 “Method for Measuring Plastic Transition Temperature”. Of “extrapolated glass transition start temperature”.

The weight average molecular weight (Mw) of the amorphous polyester resin is preferably from 5,000 to 1,000,000, and more preferably from 7,000 to 500,000.
The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2000 or more and 100,000 or less.
The molecular weight distribution Mw / Mn of the amorphous polyester resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less.
The weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed with a THF solvent using a Tosoh GPC / HLC-8120GPC as a measuring device and a Tosoh column / TSKgel SuperHM-M (15 cm). The weight average molecular weight and the number average molecular weight are calculated using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample from this measurement result.

The amorphous polyester resin can be obtained by a known production method. Specifically, for example, the polymerization temperature is set to 180 ° C. or higher and 230 ° C. or lower, the pressure in the reaction system is reduced as necessary, and the reaction is performed while removing water and alcohol generated during the condensation.
In addition, when the monomer of the raw material is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added and dissolved as a solubilizing agent. In this case, the polycondensation reaction is performed while distilling off the solubilizer. If a monomer with poor compatibility is present in the copolymerization reaction, the monomer with poor compatibility and the monomer and the acid or alcohol to be polycondensed are condensed in advance and then polymerized together with the main component. It is good to condense.

  Here, examples of the polyester resin include modified polyester resins in addition to the above-described unmodified polyester resins. The modified polyester resin is a polyester resin in which a bonding group other than an ester bond is present, or a polyester resin in which a resin component different from the polyester resin component is bonded by a covalent bond or an ionic bond. Examples of the modified polyester include a resin in which a functional group such as an isocyanate group that reacts with an acid group or a hydroxyl group is introduced at the terminal, and a resin in which the terminal is modified by reacting with an active hydrogen compound.

As the modified polyester resin, a urea-modified polyester resin is particularly preferable. The content of the urea-modified polyester resin is preferably 2% by mass or more and 25% by mass or less, and more preferably 5% by mass or more and 20% by mass or less with respect to the total binder resin.
The urea-modified polyester resin is often a kind of amorphous resin, although it depends on the type of monomer used, the blending amount, and the like.

  The urea-modified polyester resin is preferably a urea-modified polyester resin obtained by a reaction between a polyester resin having an isocyanate group (polyester prepolymer) and an amine compound (at least one of a crosslinking reaction and an extension reaction). Note that the urea-modified polyester may contain a urethane bond as well as a urea bond.

  Examples of the polyester prepolymer having an isocyanate group include a polyester which is a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol, and a prepolymer obtained by reacting a polyvalent isocyanate compound with a polyester having active hydrogen. . Examples of the group having active hydrogen in the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like, and alcoholic hydroxyl groups are preferable.

  In the polyester prepolymer having an isocyanate group, examples of the polyvalent carboxylic acid and polyhydric alcohol include the same compounds as the polyvalent carboxylic acid and polyhydric alcohol described in the polyester resin.

Examples of the polyvalent isocyanate compound include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic Diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; the polyisocyanates such as phenol derivatives, oximes, caprolactam What blocked with the blocking agent is mentioned.
A polyvalent isocyanate compound may be used individually by 1 type, and may use 2 or more types together.

  The ratio of the polyvalent isocyanate compound is preferably 1/1 or more and 5/1 or less as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester prepolymer having a hydroxyl group. Preferably it is 1.2 / 1 or more and 4/1 or less, More preferably, it is 1.5 / 1 or more and 2.5 / 1 or less.

  In the polyester prepolymer having an isocyanate group, the content of the component derived from the polyvalent isocyanate compound is preferably 0.5% by mass or more and 40% by mass or less, more preferably, based on the entire polyester prepolymer having an isocyanate group. 1 mass% or more and 30 mass% or less, More preferably, they are 2 mass% or more and 20 mass% or less.

  The number of isocyanate groups contained per molecule of the polyester prepolymer having an isocyanate group is preferably 1 or more on average, more preferably 1.5 or more and 3 or less, and even more preferably 1.8 or more on average. .5 or less.

  Examples of the amine compound that reacts with the polyester prepolymer having an isocyanate group include diamine, trivalent or higher polyamine, amino alcohol, amino mercaptan, amino acid, and compounds in which these amino groups are blocked.

Examples of diamines include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, isophoronediamine, etc. ); And aliphatic diamines (ethylenediamine, tetramethylenediamine, hexamethylenediamine, etc.) and the like.
Examples of the trivalent or higher polyamine include diethylenetriamine and triethylenetetramine.
Examples of amino alcohols include ethanolamine and hydroxyethylaniline.
Examples of amino mercaptans include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of amino acids include aminopropionic acid and aminocaproic acid.
These amino group-blocked ones include ketimine compounds obtained from amine compounds such as diamines, trivalent or higher polyamines, amino alcohols, amino mercaptans, amino acids and ketone compounds (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), Examples include oxazoline compounds.
Of these amine compounds, ketimine compounds are preferred.
An amine compound may be used individually by 1 type, and may use 2 or more types together.

Note that the urea-modified polyester resin is a polyester resin having an isocyanate group (polyester prepolymer) by a stopper that stops at least one of a crosslinking reaction and an extension reaction (hereinafter also referred to as “crosslinking / extension reaction stopper”). It may be a resin in which the molecular weight after the reaction is adjusted by adjusting the reaction with the amine compound (at least one of a crosslinking reaction and an extension reaction).
Examples of the crosslinking / extension reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, and the like), and those blocked (ketimine compounds).

  The ratio of the amine compound is preferably 1/2 or more and 2 as an equivalent ratio [NCO] / [NHx] of the isocyanate group [NCO] in the polyester prepolymer having an isocyanate group and the amino group [NHx] in the amines. / 1 or less, more preferably from 1 / 1.5 to 1.5 / 1, and even more preferably from 1 / 1.2 to 1.2 / 1.

  The glass transition temperature of the urea-modified polyester resin is preferably 40 ° C. or higher and 65 ° C. or lower, and more preferably 45 ° C. or higher and 60 ° C. or lower. The number average molecular weight is preferably 2500 or more and 50000 or less, and more preferably 2500 or more and 30000 or less. The weight average molecular weight is preferably 10,000 to 500,000, more preferably 30,000 to 100,000.

Crystalline polyester resin Examples of the crystalline polyester resin include a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol. In addition, as a crystalline polyester resin, a commercial item may be used and what was synthesize | combined may be used.
Here, since the crystalline polyester resin easily forms a crystal structure, a polycondensate using a polymerizable monomer having a linear aliphatic group is preferable to a polymerizable monomer having an aromatic group.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (for example, oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid. Acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc.), aromatic dicarboxylic acid (eg phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid) Dibasic acids such as acids), anhydrides thereof, or lower (for example, having 1 to 5 carbon atoms) alkyl esters.
The polyvalent carboxylic acid may be used in combination with a dicarboxylic acid or a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent carboxylic acid include aromatic carboxylic acids (for example, 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, etc.), these Examples thereof include anhydrides and lower (for example, having 1 to 5 carbon atoms) alkyl esters thereof.
As the polyvalent carboxylic acid, a dicarboxylic acid having a sulfonic acid group or a dicarboxylic acid having an ethylenic double bond may be used in combination with these dicarboxylic acids.
Polyvalent carboxylic acid may be used individually by 1 type, and may use 2 or more types together.

Examples of the polyhydric alcohol include aliphatic diols (for example, linear aliphatic diols having a main chain portion having 7 to 20 carbon atoms). Examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8- Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18- Examples include octadecanediol and 1,14-eicosandecanediol. Among these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable as the aliphatic diol.
The polyhydric alcohol may be used in combination with a diol and a trivalent or higher alcohol having a crosslinked structure or a branched structure. Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like.
A polyhydric alcohol may be used individually by 1 type, and may use 2 or more types together.

  Here, the polyhydric alcohol may have an aliphatic diol content of 80 mol% or more, and preferably 90 mol% or more.

The melting temperature of the crystalline polyester resin is preferably 50 ° C. or higher and 100 ° C. or lower, more preferably 55 ° C. or higher and 90 ° C. or lower, and further preferably 60 ° C. or higher and 85 ° C. or lower.
The melting temperature is determined from the “melting peak temperature” described in the method for determining the melting temperature of JIS K7121-1987 “Method for measuring the transition temperature of plastic” from the DSC curve obtained by differential scanning calorimetry (DSC).

  The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 or more and 35,000 or less.

  The crystalline polyester resin can be obtained by, for example, a well-known manufacturing method, similarly to the amorphous polyester resin.

  The content of the binder resin is, for example, preferably 40% by mass to 95% by mass, more preferably 50% by mass to 90% by mass, and more preferably 60% by mass to 85% by mass with respect to the entire toner particles. Further preferred.

-Colorant-
Examples of the colorant include carbon black, chrome yellow, hansa yellow, benzidine yellow, sren yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliant carmine 3B, and brilliant. Carmine 6B, Dupont Oil Red, Pyrazolone Red, Resol Red, Rhodamine B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malachite green oxalate, or acridine, xanthene, , Benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, thiazole, and other dyes Etc.
A colorant may be used individually by 1 type and may use 2 or more types together.

  As the colorant, a surface-treated colorant may be used as necessary, or it may be used in combination with a dispersant. A plurality of colorants may be used in combination.

  The content of the colorant is, for example, preferably 1% by mass or more and 30% by mass or less, and more preferably 3% by mass or more and 15% by mass or less with respect to the entire toner particles.

-Release agent-
Examples of mold release agents include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; and ester waxes such as fatty acid esters and montanic acid esters. And so on. The release agent is not limited to this.

The melting temperature of the release agent is preferably 50 ° C. or higher and 110 ° C. or lower, and more preferably 60 ° C. or higher and 100 ° C. or lower.
Note that the melting temperature is obtained from the DSC curve obtained by differential scanning calorimetry (DSC) according to “melting peak temperature” described in JIS K 7121-1987 “Method for measuring the melting temperature of plastics”. .

  The content of the release agent is, for example, preferably 1% by mass to 20% by mass and more preferably 5% by mass to 15% by mass with respect to the entire toner particles.

-Other additives-
Examples of other additives include known additives such as a magnetic material, a charge control agent, and inorganic powder. These additives are contained in the toner particles as internal additives.

-Toner particle characteristics-
The toner particles may be toner particles having a single layer structure, or toner particles having a so-called core / shell structure composed of a core (core particle) and a coating layer (shell layer) covering the core. May be.
Here, the core / shell structure toner particles include, for example, a core portion including a binder resin and, if necessary, other additives such as a colorant and a release agent, and a binder resin. It is good to be comprised with the comprised coating layer.

  The volume average particle diameter (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, and more preferably 4 μm or more and 8 μm or less.

In addition, various average particle diameters and various particle size distribution indexes of toner particles are measured using Coulter Multisizer II (manufactured by Beckman Coulter, Inc.), and an electrolytic solution is measured using ISOTON-II (manufactured by Beckman Coulter, Inc.). The
In the measurement, 0.5 mg to 50 mg of a measurement sample is added as a dispersant to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzenesulfonate). This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolyte in which the sample is suspended is dispersed for 1 minute with an ultrasonic disperser, and the particle size distribution of particles having a particle size in the range of 2 μm to 60 μm is measured using a 100 μm aperture with a Coulter Multisizer II. taking measurement. The number of particles to be sampled is 50,000.
For the particle size range (channel) divided based on the measured particle size distribution, the cumulative distribution is drawn from the smaller diameter side to the volume and number, respectively, and the particle size to be 16% is the volume particle size D16v, the number particle size D16p, a particle size that is 50% cumulative is defined as a volume average particle size D50v, a cumulative number average particle size D50p, and a particle size that is 84% cumulative is defined as a volume particle size D84v and a number particle size D84p.
Using these, the volume particle size distribution index (GSDv) is calculated as (D84v / D16v) ^1/2 and the number particle size distribution index (GSDp) is calculated as (D84p / D16p) ^1/2 .

  The average circularity of the toner particles is preferably from 0.94 to 1.00, more preferably from 0.95 to 0.98.

The average circularity of the toner particles is obtained by (circle equivalent perimeter) / (perimeter) [(perimeter of a circle having the same projection area as the particle image) / (perimeter of the particle projected image)]. Specifically, it is a value measured by the following method.
First, the toner particles to be measured are collected by suction, a flat flow is formed, a flash image is instantaneously emitted, a particle image is captured as a still image, and the particle image is analyzed (Sysmex). FPIA-2100) manufactured by the company. The number of samplings for obtaining the average circularity is 3500.
When the toner has an external additive, the toner (developer) to be measured is dispersed in water containing a surfactant and then subjected to ultrasonic treatment to obtain toner particles from which the external additive has been removed. .

(External additive)
In the toner according to the exemplary embodiment, other external additives may be added in addition to the composite particles described above.
Examples of the external additive include inorganic particles. As the inorganic particles, SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO. _{SiO 2, K 2 O · (} TiO 2) n, Al 2 O 3 · 2SiO 2, CaCO 3, MgCO 3, BaSO 4, MgSO 4 , and the like.

The surface of the inorganic particles as an external additive is preferably subjected to a hydrophobic treatment. The hydrophobic treatment is performed, for example, by immersing inorganic particles in a hydrophobic treatment agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, and aluminum coupling agents. These may be used individually by 1 type and may use 2 or more types together.
The amount of the hydrophobizing agent is usually 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic particles, for example.

  Examples of external additives include resin particles (resin particles such as polystyrene, polymethyl methacrylate (PMMA), and melamine resin), cleaning activators (for example, metal salts of higher fatty acids typified by zinc stearate, fluorine-based high molecular weight substances). Particle) and the like.

(Toner production method)
Next, a toner manufacturing method according to this embodiment will be described.
The toner according to the exemplary embodiment can be obtained by externally adding an external additive containing the composite particles described above to the toner particles after the toner particles are manufactured.

  The toner particles may be produced by any of a dry production method (for example, a kneading and pulverizing method) and a wet production method (for example, an aggregation coalescence method, a suspension polymerization method, a dissolution suspension method, etc.). The production method of the toner particles is not particularly limited, and a known production method is adopted.

For example, the dissolution suspension method includes a particle dispersant obtained by dissolving or dispersing a raw material (binder resin, colorant, etc.) constituting toner particles in an organic solvent in which the binder resin can be dissolved. In this method, toner particles are granulated by dispersing in an aqueous solvent and then removing the organic solvent.
The aggregation coalescence method is a method of obtaining toner particles through an aggregation step of forming aggregates of raw materials (resin particles and colorants) constituting the toner particles and a fusion step of fusing the aggregates. .

[Dissolution suspension method]
Among these, toner particles containing a urea-modified polyester resin as a binder resin are preferably obtained by the following dissolution suspension method. In the following description of the dissolution suspension method, a method for obtaining toner particles containing an unmodified polyester resin and a urea-modified polyester resin as a binder resin will be described. However, only the urea-modified polyester resin is used as a binder resin. May be included.

-Oil phase liquid preparation process-
An oil phase liquid is prepared by dissolving or dispersing a toner particle material containing an unmodified polyester resin, a polyester prepolymer having an isocyanate group, an amine compound, a colorant, and a release agent in an organic solvent (oil phase liquid preparation step). . In the oil phase liquid preparation step, the toner particle material is dissolved or dispersed in an organic solvent to obtain a mixed liquid of the toner material.

  The oil phase liquid is prepared by 1) a method in which toner materials are collectively dissolved or dispersed in an organic solvent, and 2) after kneading the toner materials in advance and then dissolving or dispersing the kneaded material in an organic solvent. 3) A method of preparing an unmodified polyester resin, a polyester prepolymer having an isocyanate group, an amine compound dissolved in an organic solvent, and then dispersing a colorant and a release agent in the organic solvent, 4) A method in which a colorant and a release agent are dispersed in an organic solvent, and then an unmodified polyester resin, a polyester prepolymer having an isocyanate group, and an amine compound are dissolved in the organic solvent, and 5) an isocyanate. Dissolve toner particle materials (unmodified polyester resin, colorant, and release agent) other than polyester prepolymer having amine group and amine compound in organic solvent Is a method in which a polyester prepolymer having an isocyanate group and an amine compound are dissolved in this organic solvent, and 6) toner particle material other than the polyester prepolymer having an isocyanate group or the amine compound (unmodified polyester) Examples thereof include a method in which a resin, a colorant, and a release agent) are dissolved or dispersed in an organic solvent and then a polyester prepolymer having an isocyanate group or an amine compound is dissolved in the organic solvent. The method for preparing the oil phase liquid is not limited to these.

  Examples of the organic solvent for the oil phase liquid include ester solvents such as methyl acetate and ethyl acetate; ketone solvents such as methyl ethyl ketone and methyl isopropyl ketone; aliphatic hydrocarbon solvents such as hexane and cyclohexane; dichloromethane, chloroform, trichloroethylene, and the like Examples thereof include halogenated hydrocarbon solvents. These organic solvents are those that dissolve the binder resin, have a ratio of dissolving in water of about 0% by mass to 30% by mass, and preferably have a boiling point of 100 ° C. or less. Of these organic solvents, ethyl acetate is preferred.

-Suspension preparation process-
Next, the obtained oil phase liquid is dispersed in an aqueous phase liquid to prepare a suspension (suspension preparation step).
Then, along with the preparation of the suspension, the polyester prepolymer having an isocyanate group and the amine compound are reacted. This reaction produces a urea-modified polyester resin. This reaction is accompanied by at least one of a molecular chain crosslinking reaction and an extension reaction. In addition, you may perform reaction of the polyester prepolymer which has this isocyanate group, and an amine compound with the solvent removal process mentioned later.
Here, the reaction conditions are selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer and the amine compound. As an example, the reaction time is preferably 10 minutes to 40 hours, and more preferably 2 hours to 24 hours. The reaction temperature is preferably 0 ° C. or higher and 150 ° C., and preferably 40 ° C. or higher and 98 ° C. or lower. In addition, you may use a well-known catalyst (Dibutyltin laurate, a dioctyltin laurate, etc.) as needed for the production | generation of a urea modified polyester resin. That is, the catalyst may be added to the oil phase liquid or suspension.

  Examples of the aqueous phase liquid include an aqueous phase liquid in which a particle dispersant such as an organic particle dispersant and an inorganic particle dispersant is dispersed in an aqueous solvent. Examples of the aqueous phase liquid include an aqueous phase liquid in which the particle dispersant is dispersed in an aqueous solvent and the polymer dispersant is dissolved in the aqueous solvent. In addition, you may add well-known additives, such as surfactant, to an aqueous phase liquid.

  Examples of the aqueous solvent include water (for example, usually ion-exchanged water, distilled water, and pure water). An aqueous solvent is a solvent containing water and an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methylcellosolve, etc.), and lower ketones (acetone, methyl ethyl ketone, etc.). There may be.

  Examples of the organic particle dispersant include hydrophilic organic particle dispersants. Examples of the organic particle dispersant include particles of poly (meth) acrylic acid alkyl ester resin (for example, polymethyl methacrylate resin), polystyrene resin, poly (styrene-acrylonitrile) resin, and the like. Examples of the organic particle dispersant include styrene acrylic resin particles.

  Examples of the inorganic particle dispersant include hydrophilic inorganic particle dispersants. Specific examples of the inorganic particle dispersant include particles of silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, clay, diatomaceous earth, bentonite, and the like, and calcium carbonate particles are preferable. An inorganic particle dispersing agent may be used individually by 1 type, and may use 2 or more types together.

The particle dispersant may be surface-treated with a polymer having a carboxyl group on the surface.
Examples of the polymer having a carboxyl group include a carboxyl group of an α, β-monoethylenically unsaturated carboxylic acid or an α, β-monoethylenically unsaturated carboxylic acid formed by an alkali metal, an alkaline earth metal, ammonia, an amine, or the like. And a copolymer of at least one selected from neutralized salts (alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts, etc.) and α, β-monoethylenically unsaturated carboxylic acid esters. It is done. As the polymer having a carboxyl group, the carboxyl group of a copolymer of an α, β-monoethylenically unsaturated carboxylic acid and an α, β-monoethylenically unsaturated carboxylic acid ester is an alkali metal or an alkaline earth metal. And salts neutralized with ammonia, amines, etc. (alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts, etc.). The said polymer which has a carboxyl group may be used individually by 1 type, and may use 2 or more types together.

  Typical α, β-monoethylenically unsaturated carboxylic acids include α, β-unsaturated monocarboxylic acids (acrylic acid, methacrylic acid, crotonic acid, etc.), α, β-unsaturated dicarboxylic acids (maleic acid). Acid, fumaric acid, itaconic acid, etc.). Representative examples of α, β-monoethylenically unsaturated carboxylic acid esters include alkyl esters of (meth) acrylic acid, (meth) acrylates having an alkoxy group, (meth) acrylates having a cyclohexyl group, Examples include (meth) acrylate having a hydroxy group, polyalkylene glycol mono (meth) acrylate, and the like.

  Examples of the polymer dispersant include hydrophilic polymer dispersants. Specifically, as the polymer dispersant, a polymer dispersant having a carboxyl group and having no lipophilic group (hydroxypropoxy group, methoxy group, etc.) (for example, water-soluble carboxymethyl cellulose, carboxyethyl cellulose, etc.) ).

-Solvent removal step-
Next, the organic solvent is removed from the obtained suspension to obtain a toner particle dispersion (solvent removal step). This solvent removal step is a step of generating toner particles by removing the organic solvent contained in the droplets of the aqueous phase liquid dispersed in the suspension. The removal of the organic solvent from the suspension may be performed immediately after the suspension preparation step, or may be performed after 1 minute or more has elapsed after completion of the suspension preparation step.
In the solvent removal step, the organic solvent is preferably removed from the suspension by cooling or heating the obtained suspension in a range of, for example, 0 ° C. or more and 100 ° C. or less.

Specific methods for removing the organic solvent include the following methods.
(1) A method of forcibly renewing the gas phase on the surface of the suspension by blowing an air stream on the suspension. In this case, gas may be blown into the suspension.
(2) A method of reducing the pressure. In this case, the gas phase on the surface of the suspension may be forcibly updated by filling with gas, or gas may be blown into the suspension.

Through the above steps, toner particles are obtained.
Here, after completion of the solvent removal step, the toner particles formed in the toner particle dispersion are obtained as toner particles in a dried state through a known washing step, solid-liquid separation step, and drying step.
In the washing step, it is preferable to sufficiently carry out substitution washing with ion-exchanged water from the viewpoint of chargeability.
The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, etc. are preferably performed from the viewpoint of productivity. In addition, the drying process is not particularly limited, but from the viewpoint of productivity, freeze drying, airflow drying, fluidized drying, vibration fluidized drying, or the like is preferably performed.

The toner according to the exemplary embodiment is manufactured, for example, by adding the external additive containing the composite particles described above to the obtained dry toner particles and mixing them.
Mixing is preferably performed by, for example, a V blender, a Henschel mixer, a Laedige mixer, or the like.
Further, if necessary, coarse toner particles may be removed using a vibration sieving machine, a wind sieving machine, or the like.

[Kneading and grinding method]
In the kneading and pulverization method, after mixing each material such as a colorant, the above materials are melt-kneaded using a kneader, an extruder, etc., and the resulting melt-kneaded material is roughly pulverized and then pulverized with a jet mill or the like. In this method, toner particles having a target particle size are obtained using an air classifier.
More specifically, the kneading and pulverizing method is divided into a kneading step for kneading a toner forming material containing a colorant and a binder resin, and a pulverizing step for pulverizing the kneaded product. As needed, you may have other processes, such as a cooling process of cooling the kneaded material formed by the kneading process.

Each step related to the kneading and pulverizing method will be described in detail.
-Kneading process-
In the kneading step, a toner forming material containing a colorant and a binder resin is kneaded.
In the kneading step, it is desirable to add 0.5 to 5 parts by mass of an aqueous medium (for example, water such as distilled water or ion exchange water, alcohols, etc.) to 100 parts by mass of the toner forming material. .

  Examples of the kneader used in the kneading step include a single screw extruder, a twin screw extruder, and the like. Hereinafter, as an example of a kneader, a kneader having a feed screw portion and two kneading portions will be described with reference to the drawings, but the present invention is not limited to this.

FIG. 3 is a diagram illustrating the state of a screw in an example of a screw extruder used in a kneading step in the toner manufacturing method according to the present embodiment.
The screw extruder 11 includes a barrel 12 having a screw (not shown), an inlet 14 for injecting a toner forming material as a raw material of the toner into the barrel 12, and an aqueous medium added to the toner forming material in the barrel 12. A liquid addition port 16 for discharging the toner, and a discharge port 18 for discharging the kneaded material formed by kneading the toner forming material in the barrel 12.

  The barrel 12 is a feed screw portion SA that transports the toner forming material injected from the injection port 14 to the kneading portion NA in order from the side closer to the injection port 14, and melt-kneading the toner forming material in the first kneading step. The kneading part NA, the feed screw part SB for transporting the toner forming material melted and kneaded in the kneading part NA to the kneading part NB, and the knee for melting and kneading the toner forming material in the second kneading step to form a kneaded product. It is divided into a ding part NB and a feed screw part SC that transports the formed kneaded material to the discharge port 18.

  The barrel 12 is provided with temperature control means (not shown) that is different for each block. That is, the temperature may be controlled at different temperatures from the block 12A to the block 12J. FIG. 3 shows a state in which the temperatures of the block 12A and the block 12B are controlled to t0 ° C., the temperatures of the blocks 12C to 12E are controlled to t1 ° C., and the temperatures of the blocks 12F to 12J are controlled to t2 ° C. Yes. Therefore, the toner forming material of the kneading part NA is heated to t1 ° C., and the toner forming material of the kneading part NB is heated to t2 ° C.

  When a toner forming material including a binder resin, a colorant, and a release agent as necessary is supplied from the injection port 14 to the barrel 12, the toner forming material is sent to the kneading portion NA by the feed screw portion SA. At this time, since the temperature of the block 12C is set to t1 ° C., the toner forming material is fed into the kneading portion NA in a state of being heated and changed into a molten state. Since the temperatures of the block 12D and the block 12E are also set to t1 ° C., the toner forming material is melt-kneaded at the temperature of t1 ° C. in the kneading portion NA. The binder resin and the release agent are in a molten state at the kneading portion NA and are subjected to shearing by the screw.

Next, the toner forming material that has been kneaded in the kneading part NA is sent to the kneading part NB by the feed screw part SB.
Next, the aqueous medium is added to the toner forming material by injecting the aqueous medium into the barrel 12 from the liquid addition port 16 in the feed screw portion SB. FIG. 3 shows a mode in which the aqueous medium is injected in the feed screw part SB. However, the present invention is not limited to this, and the aqueous medium may be injected in the kneading part NB. In both cases, an aqueous medium may be injected. That is, the position and the injection location for injecting the aqueous medium are selected as necessary.

As described above, when the aqueous medium is injected into the barrel 12 from the liquid addition port 16, the toner forming material and the aqueous medium in the barrel 12 are mixed, and the toner forming material is cooled by the latent heat of vaporization of the aqueous medium, The temperature of the toner forming material is maintained.
Finally, the kneaded material formed by being melt-kneaded by the kneading part NB is transported to the discharge port 18 by the feed screw part SC and discharged from the discharge port 18.
As described above, the kneading step using the screw extruder 11 shown in FIG. 3 is performed.

-Cooling process-
The cooling step is a step of cooling the kneaded product formed in the kneading step. In the cooling step, cooling is performed from the temperature of the kneaded product at the end of the kneading step to 40 ° C. or lower at an average temperature decrease rate of 4 ° C./sec or higher. It is preferable to do. When the cooling rate of the kneaded product is slow, a mixture finely dispersed in the binder resin in the kneading step (a mixture of a colorant and an internal additive such as a release agent that is internally added to the toner particles as necessary) ) May recrystallize and the dispersion diameter may increase. On the other hand, quenching at the above average temperature drop rate is preferable because the dispersion state immediately after the end of the kneading process is maintained as it is. The average temperature decreasing rate refers to the average value of the temperature decreasing rate from the temperature of the kneaded product at the end of the kneading step (for example, t2 ° C. when using the screw extruder 11 in FIG. 3) to 40 ° C.
Specific examples of the cooling method in the cooling step include a method using a rolling roll in which cold water or brine is circulated, a sandwiching cooling belt, and the like. When cooling is performed by the above method, the cooling rate is determined by the speed of the rolling roll, the flow rate of brine, the supply amount of the kneaded material, the slab thickness at the time of rolling the kneaded material, and the like. The slab thickness is preferably 1 mm or more and 3 mm or less.

-Crushing process-
The kneaded product cooled in the cooling step is pulverized in the pulverization step, and particles are formed. In the pulverization step, for example, a mechanical pulverizer or a jet pulverizer is used.

-Classification process-
The particles obtained by the pulverization step may be classified by a classification step in order to obtain toner particles having a volume average particle diameter in a target range, if necessary. In the classification process, conventionally used centrifugal classifiers, inertia classifiers, etc. are used, and fine powder (particles smaller than the target particle size) and coarse powder (target particle size). Larger particles) are removed.

-External addition process-
The composite particles described above are externally added to the obtained toner particles. Further, for the purpose of adjusting the charge, imparting fluidity, imparting charge exchange, etc., external additives such as inorganic particles represented by silica, titania and aluminum oxide may be added and adhered. These are performed by, for example, a V-type blender, a Henschel mixer, a Redige mixer, or the like, and may be attached in stages.

-Sieving process-
You may provide a sieving process after the said external addition process as needed. Specific examples of the sieving method include a gyro shifter, a vibration sieving machine, and a wind sieving machine. By sieving, coarse particles of the external additive and the like are removed, and generation of streaks on the photosensitive member and scumming in the apparatus are suppressed.

[Aggregating coalescence method]
In this embodiment, an aggregation coalescence method may be used in which the shape of the toner particles and the particle diameter of the toner particles can be easily controlled, and the control range of the toner particle structure such as a core-shell structure is wide. Hereinafter, a method for producing toner particles by the aggregation coalescence method will be described in detail.

Specifically, for example, when toner particles are produced by an aggregation coalescence method,
A step of preparing a resin particle dispersion in which resin particles to be a binder resin are dispersed (resin particle dispersion preparation step), and a resin particle dispersion (after mixing other particle dispersions as necessary) In the dispersion), the resin particles (other particles as necessary) are aggregated to form aggregated particles (aggregated particle formation step), and the aggregated particle dispersion in which the aggregated particles are dispersed is heated. Then, toner particles are manufactured through a process of fusing and coalescing the aggregated particles to form toner particles (fusing and coalescing process).

Details of each step will be described below.
In the following description, a method of obtaining toner particles containing a colorant and a release agent will be described. However, the colorant and the release agent are used as necessary. Of course, you may use other additives other than a coloring agent and a mold release agent.

-Preparation step of resin particle dispersion-
First, together with a resin particle dispersion in which resin particles serving as a binder resin are dispersed, for example, a colorant particle dispersion in which colorant particles are dispersed and a release agent particle dispersion in which release agent particles are dispersed are prepared. To do.

  Here, the resin particle dispersion is prepared, for example, by dispersing resin particles in a dispersion medium using a surfactant.

Examples of the dispersion medium used for the resin particle dispersion include an aqueous medium.
Examples of the aqueous medium include water such as distilled water and ion exchange water, and alcohols. These may be used individually by 1 type and may use 2 or more types together.

Examples of the surfactant include anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol And nonionic surfactants such as polyphenols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, an anionic surfactant and a cationic surfactant are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
Surfactant may be used individually by 1 type and may use 2 or more types together.

Examples of the method for dispersing the resin particles in the dispersion medium in the resin particle dispersion include a general dispersion method such as a rotary shear homogenizer, a ball mill having media, a sand mill, and a dyno mill. Depending on the type of resin particles, the resin particles may be dispersed in the resin particle dispersion using, for example, a phase inversion emulsification method.
The phase inversion emulsification method is a method in which a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, and a base is added to the organic continuous phase (O phase) to neutralize the aqueous medium. (W phase) is added to convert the resin from W / O to O / W (so-called phase inversion) to form a discontinuous phase and disperse the resin in an aqueous medium in the form of particles. It is.

The volume average particle size of the resin particles dispersed in the resin particle dispersion is, for example, preferably 0.01 μm to 1 μm, more preferably 0.08 μm to 0.8 μm, and further preferably 0.1 μm to 0.6 μm. preferable.
In addition, the volume average particle diameter of the resin particles is based on the particle size range (channel) divided by using the particle size distribution obtained by measurement with a laser diffraction particle size distribution measuring apparatus (for example, LA-700 manufactured by Horiba, Ltd.). The cumulative distribution is subtracted from the small particle diameter side with respect to the volume, and the particle diameter that becomes 50% cumulative with respect to all particles is measured as the volume average particle diameter D50v. The volume average particle size of particles in other dispersions is also measured in the same manner.

  As content of the resin particle contained in a resin particle dispersion liquid, 5 to 50 mass% is preferable, for example, and 10 to 40 mass% is more preferable.

  For example, a colorant particle dispersion and a release agent particle dispersion are also prepared in the same manner as the resin particle dispersion. In other words, regarding the volume average particle diameter of the particles in the resin particle dispersion, the dispersion medium, the dispersion method, and the content of the particles, the colorant particles dispersed in the colorant particle dispersion and the release agent particle dispersion The same applies to the release agent particles to be dispersed.

-Aggregated particle formation process-
Next, the colorant particle dispersion and the release agent particle dispersion are mixed together with the resin particle dispersion.
Then, in the mixed dispersion, resin particles, colorant particles, and release agent particles are hetero-aggregated to have resin particles, colorant particles, and release agent particles having a diameter close to the diameter of the target toner particles. Aggregated particles are formed.

Specifically, for example, the flocculant is added to the mixed dispersion, and the pH of the mixed dispersion is adjusted to acidic (for example, the pH is 2 or more and 5 or less), and a dispersion stabilizer is added as necessary. The resin particles are heated to a glass transition temperature (specifically, for example, the glass transition temperature of the resin particles −30 ° C. or more and the glass transition temperature −10 ° C. or less), and the particles dispersed in the mixed dispersion liquid are aggregated. , Forming aggregated particles.
In the agglomerated particle forming step, for example, the aggregating agent is added at room temperature (for example, 25 ° C.) while stirring the mixed dispersion with a rotary shearing homogenizer, and the pH of the mixed dispersion is acidic (for example, the pH is 2 or more and 5 or less). ), And after adding a dispersion stabilizer as necessary, the heating may be performed.

Examples of the flocculant include a surfactant having a polarity opposite to that of the surfactant used as the dispersant added to the mixed dispersion, an inorganic metal salt, and a divalent or higher-valent metal complex. In particular, when a metal complex is used as the flocculant, the amount of the surfactant used is reduced, and the charging characteristics are improved.
If necessary, an additive that forms a complex or a similar bond with the metal ion of the flocculant may be used. As this additive, a chelating agent is preferably used.

Examples of inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and inorganic substances such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include metal salt polymers.
A water-soluble chelating agent may be used as the chelating agent. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid, iminodiacid (IDA), nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), and the like.
As addition amount of a chelating agent, 0.01 mass part or more and 5.0 mass part or less are preferable with respect to 100 mass parts of resin particles, for example, and 0.1 mass part or more and less than 3.0 mass parts are more preferable.

-Fusion / unification process-
Next, the aggregated particle dispersion in which the aggregated particles are dispersed is heated to, for example, a glass transition temperature or higher of the resin particles (for example, a temperature of 10 to 30 ° C. higher than the glass transition temperature of the resin particles). Are fused and united to form toner particles.

Through the above steps, toner particles are obtained.
In addition, after obtaining the aggregated particle dispersion liquid in which the aggregated particles are dispersed, the aggregated particle dispersion liquid and the resin particle dispersion liquid in which the resin particles are dispersed are further mixed, and the resin particles are further added to the surface of the aggregated particles. A process of aggregating to adhere to form second aggregated particles, and heating the second aggregated particle dispersion in which the second aggregated particles are dispersed to fuse and coalesce the second aggregated particles. The toner particles may be manufactured through a step of forming toner particles having a core / shell structure.

Here, after completion of the fusion / unification process, toner particles formed in the solution are dried through a known washing process, solid-liquid separation process, and drying process to obtain toner particles.
In the washing step, it is preferable to sufficiently carry out substitution washing with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, etc. are preferably performed from the viewpoint of productivity. In addition, the drying process is not particularly limited, but from the viewpoint of productivity, freeze drying, airflow drying, fluidized drying, vibration fluidized drying, or the like is preferably performed.

  The toner according to the exemplary embodiment is manufactured, for example, by adding the external additive containing the composite particles described above to the obtained dry toner particles and mixing them. Mixing may be performed by, for example, a V blender, a Henschel mixer, a Laedige mixer, or the like. Further, if necessary, coarse toner particles may be removed using a vibration sieving machine, a wind sieving machine, or the like.

<Electrostatic image developer>
The electrostatic charge image developer according to the exemplary embodiment includes at least the toner according to the exemplary embodiment.
The electrostatic image developer according to this embodiment may be a one-component developer including only the toner according to this embodiment, or may be a two-component developer mixed with the toner and a carrier.

There is no restriction | limiting in particular as a carrier, A well-known carrier is mentioned. As a carrier, for example, a coated carrier in which the surface of a core made of magnetic powder is coated with a coating resin; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and mixed in a matrix resin; a porous magnetic powder is impregnated with a resin Resin impregnated type carriers; and the like.
The magnetic powder-dispersed carrier and the resin-impregnated carrier may be a carrier in which the constituent particles of the carrier are used as a core material and this is coated with a coating resin.

  Examples of the magnetic powder include magnetic metals such as iron, nickel, and cobalt, and magnetic oxides such as ferrite and magnetite.

Examples of the coating resin and the matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic acid ester. Examples thereof include a straight silicone resin comprising a copolymer, an organosiloxane bond, or a modified product thereof, a fluororesin, a polyester, a polycarbonate, a phenol resin, and an epoxy resin.
The coating resin and matrix resin may contain other additives such as conductive particles.
Examples of the conductive particles include particles of metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

Here, in order to coat the surface of the core material with the coating resin, a method of coating with a coating layer forming solution obtained by dissolving the coating resin and, if necessary, various additives in an appropriate solvent may be mentioned. The solvent is not particularly limited, and may be selected in consideration of the coating resin to be used, coating suitability, and the like.
Specific resin coating methods include a dipping method in which the core material is immersed in the coating layer forming solution, a spray method in which the coating layer forming solution is sprayed on the surface of the core material, and a state in which the core material is suspended by flowing air. Examples thereof include a fluidized bed method in which a coating layer forming solution is sprayed, a kneader coater method in which a carrier core material and a coating layer forming solution are mixed in a kneader coater, and the solvent is removed.

  The mixing ratio (mass ratio) of the toner and the carrier in the two-component developer is preferably toner: carrier = 1: 100 to 30: 100, and more preferably 3: 100 to 20: 100.

<Image Forming Apparatus / Image Forming Method>
The image forming apparatus / image forming method according to the present embodiment will be described.
The image forming apparatus according to the present embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, an electrostatic image forming unit that forms an electrostatic image on the surface of the charged image carrier, and an electrostatic charge. Development means for containing an image developer and developing the electrostatic image formed on the surface of the image carrier as a toner image with the electrostatic image developer, and the toner image formed on the surface of the image carrier as a recording medium Transfer means for transferring to the surface of the recording medium, and fixing means for fixing the toner image transferred to the surface of the recording medium. The electrostatic charge image developer according to this embodiment is applied as the electrostatic charge image developer.

  In the image forming apparatus according to this embodiment, a charging process for charging the surface of the image carrier, an electrostatic charge image forming process for forming an electrostatic image on the surface of the charged image carrier, and an electrostatic charge according to this embodiment. A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image with an image developer; a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of the recording medium; An image forming method (an image forming method according to the present embodiment) including a fixing step of fixing the toner image transferred onto the surface of the recording medium is performed.

The image forming apparatus according to the present embodiment is a direct transfer type apparatus that directly transfers a toner image formed on the surface of an image carrier to a recording medium; the toner image formed on the surface of the image carrier is transferred to an intermediate transfer member An intermediate transfer type apparatus that primarily transfers the toner image transferred to the surface of the intermediate transfer body and then secondary transfer the toner image to the surface of the recording medium; after the toner image is transferred, the surface of the image carrier before charging is cleaned. An apparatus provided with a cleaning unit; a known image forming apparatus such as an apparatus provided with a charge removing unit that discharges the surface of an image holding member by irradiating a discharge light after charging a toner image and before charging is applied.
In the case of an intermediate transfer type apparatus, the transfer means includes, for example, an intermediate transfer body on which a toner image is transferred to the surface, and a primary transfer that primarily transfers the toner image formed on the surface of the image holding body to the surface of the intermediate transfer body. And a secondary transfer unit that secondarily transfers the toner image transferred onto the surface of the intermediate transfer member onto the surface of the recording medium.

  In the image forming apparatus according to the present embodiment, for example, the part including the developing unit may have a cartridge structure (process cartridge) that is detachable from the image forming apparatus. As the process cartridge, for example, a process cartridge including a developing unit containing the electrostatic charge image developer according to the present embodiment is preferably used.

  Hereinafter, an example of the image forming apparatus according to the present embodiment will be described, but the present invention is not limited thereto. In addition, the main part shown to a figure is demonstrated and the description is abbreviate | omitted about others.

FIG. 4 is a schematic configuration diagram illustrating the image forming apparatus according to the present embodiment.
The image forming apparatus shown in FIG. 4 is a first to first electrophotographic method that outputs yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. Fourth image forming units 10Y, 10M, 10C, and 10K (image forming means) are provided. These image forming units (hereinafter sometimes simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged in parallel at a predetermined distance from each other in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from the image forming apparatus.

Above each of the units 10Y, 10M, 10C, and 10K, an intermediate transfer belt 20 as an intermediate transfer member is extended through each unit. The intermediate transfer belt 20 is provided by being wound around a drive roll 22 and a support roll 24 that are in contact with the inner surface of the intermediate transfer belt 20 that are spaced apart from each other in the left to right direction in the drawing. The vehicle travels in the direction toward the unit 10K. The support roll 24 is applied with a force in a direction away from the drive roll 22 by a spring or the like (not shown), and tension is applied to the intermediate transfer belt 20 wound around the support roll 24. An intermediate transfer member cleaning device 30 is provided on the side of the image carrier of the intermediate transfer belt 20 so as to face the drive roll 22.
Further, each of the developing devices (developing means) 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K has yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K. The toner including the four color toners is supplied.

  Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration, here, the first unit that forms a yellow image disposed on the upstream side in the intermediate transfer belt traveling direction. 10Y will be described as a representative. It should be noted that reference numerals with magenta (M), cyan (C), and black (K) are attached to the same parts as those of the first unit 10Y instead of yellow (Y). Description of the units 10M, 10C, and 10K will be omitted.

The first unit 10Y includes a photoreceptor 1Y that functions as an image holding member. Around the photoreceptor 1Y, a charging roll (an example of a charging unit) 2Y that charges the surface of the photoreceptor 1Y to a predetermined potential, and the charged surface is exposed by a laser beam 3Y based on the color-separated image signal. Then, an exposure device (an example of an electrostatic image forming unit) 3 that forms an electrostatic image, and a developing device (an example of a developing unit) 4Y that develops the electrostatic image by supplying toner charged to the electrostatic image, developed A primary transfer roll 5Y (an example of a primary transfer unit) that transfers a toner image onto the intermediate transfer belt 20, and a photoconductor cleaning device (an example of a cleaning unit) 6Y that removes toner remaining on the surface of the photoconductor 1Y after the primary transfer. Are arranged in order.
The primary transfer roll 5Y is disposed inside the intermediate transfer belt 20, and is provided at a position facing the photoreceptor 1Y. Further, a bias power source (not shown) for applying a primary transfer bias is connected to each of the primary transfer rolls 5Y, 5M, 5C, and 5K. Each bias power source varies the transfer bias applied to each primary transfer roll under the control of a control unit (not shown).

Hereinafter, an operation of forming a yellow image in the first unit 10Y will be described.
First, prior to operation, the surface of the photoreceptor 1Y is charged to a potential of −600V to −800V by the charging roll 2Y.
The photoreceptor 1Y is formed by laminating a photosensitive layer on a conductive substrate (for example, volume resistivity at 20 ° C .: 1 × 10 ⁻⁶ Ωcm or less). This photosensitive layer usually has a high resistance (general resin resistance), but has a property that the specific resistance of the portion irradiated with the laser beam changes when irradiated with the laser beam 3Y. Therefore, a laser beam 3Y is output to the surface of the charged photoreceptor 1Y via the exposure device 3 in accordance with yellow image data sent from a control unit (not shown). The laser beam 3Y is applied to the photosensitive layer on the surface of the photoreceptor 1Y, whereby an electrostatic charge image having a yellow image pattern is formed on the surface of the photoreceptor 1Y.

The electrostatic charge image is an image formed on the surface of the photoreceptor 1Y by charging, and the specific resistance of the irradiated portion of the photosensitive layer is lowered by the laser beam 3Y, and the charged charge on the surface of the photoreceptor 1Y flows. On the other hand, this is a so-called negative latent image formed by the charge remaining in the portion not irradiated with the laser beam 3Y.
The electrostatic charge image formed on the photoreceptor 1Y is rotated to a predetermined development position as the photoreceptor 1Y travels. At this development position, the electrostatic charge image on the photoreceptor 1Y is visualized (developed image) as a toner image by the developing device 4Y.

  In the developing device 4Y, for example, an electrostatic charge image developer containing at least yellow toner and a carrier is accommodated. The yellow toner is triboelectrically charged by being agitated inside the developing device 4Y, and has a charge of the same polarity (negative polarity) as the charged electric charge on the photoreceptor 1Y, and has a developer roll (a developer holding member). Example) is held on. As the surface of the photoreceptor 1Y passes through the developing device 4Y, the yellow toner is electrostatically attached to the latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed with the yellow toner. . The photoreceptor 1Y on which the yellow toner image is formed continues to run at a predetermined speed, and the toner image developed on the photoreceptor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoreceptor 1Y is conveyed to the primary transfer, a primary transfer bias is applied to the primary transfer roll 5Y, and an electrostatic force from the photoreceptor 1Y toward the primary transfer roll 5Y is applied to the toner image, so that the photoreceptor is exposed. The toner image on 1Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time has a (+) polarity opposite to the polarity (−) of the toner, and is controlled to +10 μA by the control unit (not shown) in the first unit 10Y, for example.
On the other hand, the toner remaining on the photoreceptor 1Y is removed and collected by the photoreceptor cleaning device 6Y.

Further, the primary transfer bias applied to the primary transfer rolls 5M, 5C, and 5K after the second unit 10M is also controlled in accordance with the first unit.
Thus, the intermediate transfer belt 20 onto which the yellow toner image has been transferred by the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of the respective colors are superimposed and transferred in a multiple manner. The

  The intermediate transfer belt 20 on which the four color toner images are transferred in multiple ways through the first to fourth units is disposed on the image transfer surface side of the intermediate transfer belt 20, the support roll 24 in contact with the inner surface of the intermediate transfer belt 20. The secondary transfer roll (an example of a secondary transfer unit) 26 is formed to a secondary transfer portion configured. On the other hand, a recording paper (an example of a recording medium) P is fed at a predetermined timing into a gap where the secondary transfer roll 26 and the intermediate transfer belt 20 are in contact via a supply mechanism, and the secondary transfer bias is supplied to the support roll. 24. The transfer bias applied at this time is a (−) polarity that is the same polarity as the polarity (−) of the toner, and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P is applied to the toner image, so The toner image is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by a resistance detection means (not shown) for detecting the resistance of the secondary transfer portion, and is voltage-controlled.

  Thereafter, the recording paper P is fed into the pressure contact portions (nip portions) of a pair of fixing rolls in a fixing device (an example of a fixing unit) 28, and the toner image is fixed on the recording paper P to form a fixed image.

Examples of the recording paper P to which the toner image is transferred include plain paper used in electrophotographic copying machines, printers, and the like. In addition to the recording paper P, the recording medium may be an OHP sheet.
In order to further improve the smoothness of the image surface after fixing, the surface of the recording paper P is also preferably smooth. For example, coated paper with the surface of plain paper coated with resin, art paper for printing, etc. are preferably used. Is done.

  The recording paper P on which the color image has been fixed is carried out toward the discharge unit, and a series of color image forming operations is completed.

<Process cartridge / toner cartridge>
The process cartridge according to this embodiment will be described.
The process cartridge according to the present embodiment accommodates the electrostatic charge image developer according to the present embodiment, and develops the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer. And a process cartridge that can be attached to and detached from the image forming apparatus.

  Note that the process cartridge according to the present embodiment is not limited to the above-described configuration, and other means such as a developing device and other units such as an image carrier, a charging unit, an electrostatic charge image forming unit, and a transfer unit, if necessary. And at least one selected from the above.

  Hereinafter, an example of the process cartridge according to the present embodiment will be shown, but the present invention is not limited to this. In addition, the main part shown to a figure is demonstrated and the description is abbreviate | omitted about others.

FIG. 5 is a schematic configuration diagram showing a process cartridge according to the present embodiment.
The process cartridge 200 shown in FIG. 5 is provided around the photosensitive member 107 and the photosensitive member 107 by, for example, a housing 117 provided with an attachment rail 116 and an opening 118 for exposure. A charging roller 108 (an example of a charging unit), a developing device 111 (an example of a developing unit), and a photoconductor cleaning device 113 (an example of a cleaning unit) are integrally combined and held to form a cartridge. Yes.
In FIG. 5, 109 is an exposure device (an example of an electrostatic charge image forming unit), 112 is a transfer device (an example of a transfer unit), 115 is a fixing device (an example of a fixing unit), and 300 is a recording paper (a recording medium). An example).

Next, the toner cartridge according to this embodiment will be described.
The toner cartridge according to the present exemplary embodiment is a toner cartridge that accommodates the toner according to the present exemplary embodiment and is detachable from the image forming apparatus. The toner cartridge contains toner for replenishment to be supplied to the developing means provided in the image forming apparatus.

  The image forming apparatus shown in FIG. 4 is an image forming apparatus having a configuration in which the toner cartridges 8Y, 8M, 8C, and 8K are attached to and detached from each other. The developing devices 4Y, 4M, 4C, and 4K are the developing devices (colors). And a toner supply pipe (not shown). Further, when the amount of toner stored in the toner cartridge becomes low, the toner cartridge is replaced.

  Hereinafter, although an Example and a comparative example are given and this embodiment is described in detail in detail, this embodiment is not limited to these Examples at all. “Parts” and “%” are based on mass unless otherwise specified.

(Production of composite particles)
-Preparation of composite particle 1-
・ Lubricant particles (positive charging)
Fatty acid metal salt particles, zinc stearate particles, trade name: zinc stearate, 1.5 μm, manufactured by Wako Pure Chemical Industries, Ltd., average particle size = 1.5 μm
・ Reverse polar particles (negatively charged)
Silica particles, trade name: RY50, manufactured by Nippon Aerosil Co., Ltd., average particle size = 40 nm
100 parts of the above-mentioned lubricant particles (zinc stearate) and 6.0 parts of reverse polarity particles (silica particles) are mixed, and a powder processing apparatus (Nobilta NOB130, manufactured by Hosokawa Micron Corporation) at a clearance of 3 mm and a peripheral speed of 1500 rpm. After blending for 10 minutes while flowing cooling water through the jacket, coarse particles were removed using a sieve having an opening of 45 μm to obtain composite particles having a low coverage.
On the other hand, high-coverage composite particles were obtained in the same manner as the low-coverage composite particles except that the amount of the reverse electrode particles (silica particles) was changed to 9.5 parts.
Next, the composite particles 1 having low coverage and the composite particles having high coverage were mixed at a ratio of 50:50.

After subjecting the composite particles 1 to the above-described ultrasonic treatment, the coverage of each composite particle is determined from an image taken with a scanning electron microscope (SEM), and the “number ratio (C _L : C _M )” is obtained. Was calculated. Moreover, the particle diameter of each composite particle is determined from the image obtained by this scanning electron microscope (SEM), and the composite particle satisfying the formula (1) (1 μm ≦ R _C ≦ (0.45 × R _TN )), The ratio of the composite particles satisfying the formula (2) (R _C <1 μm) to the toner particles was determined by the method described above.
Furthermore, the “number ratio (C ₊ : C ₋ )” was determined by the method described above.

-Preparation of composite particles 2-4-
In the preparation of the composite particles 1, the mixing ratio of the composite particles having a low coverage and the composite particles having a high coverage is changed, and the “number ratio (C _L : C _M )” is shown in Table 1 or Table 2 below. Composite particles were obtained in the same manner as the composite particles 1 except that the values were adjusted to the values described.

-Preparation of composite particles 5-6-
In the preparation of the composite particles 1 or 2, the lubricant particles (zinc stearate) used were changed to the following ones having a smaller diameter, and the amount of the reverse polar particles in the composite particles having a low coverage was 9.0. The composite particles were obtained in the same manner as for the composite particles 1 or 2 except that the amount of the reverse polarity particles in the high coverage composite particles was changed to 14.2 parts.
・ Lubricant particles (positive charging)
Fatty acid metal salt particles, zinc stearate particles, trade name: Nissan Electol MZ-2, manufactured by NOF Corporation, average particle size = 1.0 μm

-Preparation of composite particles 7-
In the preparation of the composite particles 1, the reverse electrode particles (silica) used were changed to the following, and the amount of the reverse electrode particles in the composite particles with a low coverage was 4.5 parts, and the composite with a high coverage was used. A composite particle was obtained in the same manner as the composite particle 1 except that the amount of the reverse electrode particle in the body particle was changed to 7.1 parts.
・ Reverse polar particles (negatively charged)
Titanium oxide particles, trade name: MT150AW, manufactured by Teika Co., Ltd., average particle size = 20 nm

-Preparation of composite particles 8-
In the preparation of the composite particles 1, the lubricant particles (zinc stearate) used were changed to the following, and the reverse polarity particles (silica) were changed to the following, and the composite particles having a low coverage were used. A composite particle was obtained in the same manner as the composite particle 1 except that the amount of the reverse electrode particle was changed to 9.5 parts and the amount of the reverse electrode particle in the high coverage composite particle was changed to 15.3 parts. .
・ Lubricant particles (negatively charged)
Polytetrafluoroethylene (PTFE) particles, trade name: L173JE, manufactured by Asahi Glass Co., Ltd., average particle size = 0.7 μm
・ Reverse polar particles (positive charging)
Surface-treated silica particles, trade name: NA50Y, manufactured by Nippon Aerosil Co., Ltd., average particle size = 30 nm

-Preparation of composite particles 9-
In the preparation of the composite particles 1, the lubricant particles (zinc stearate) and the reverse polarity particles (silica) are prepared by the following method without preparing composite particles with a low coverage and composite particles with a high coverage. The mixture was mixed and stirred.
That is, 50 parts of lubricant particles (zinc stearate) and 7.8 parts of reverse polarity particles (silica particles) are mixed, and a powder processing apparatus (Nobilta NOB130, manufactured by Hosokawa Micron Corporation) at a clearance of 3 mm and a peripheral speed of 1500 rpm. After blending for 5 minutes while flowing cooling water through the jacket, the powder processing apparatus is temporarily stopped, 50 parts of lubricant particles (zinc stearate) are added again, and cooling water is supplied to the jacket again at a clearance of 3 mm and a peripheral speed of 1500 rpm. For 5 minutes. Thereafter, coarse particles were removed using a sieve having an opening of 45 μm to obtain composite particles.

-Preparation of composite particles 10-11 (composite particles for comparative example)-
In the preparation of the composite particles 1, the mixing ratio of the composite particles having a low coverage and the composite particles having a high coverage is changed, and the “number ratio (C _L : C _M )” is shown in Table 1 or Table 2 below. Composite particles were obtained in the same manner as the composite particles 1 except that the values were adjusted to the values described.

(Production of toner particles)
-Production of toner particles 1-
(Preparation of amorphous polyester resin particle dispersion)
-Bisphenol A ethylene oxide 2.2 mol adduct: 40 mol parts-Bisphenol A propylene oxide 2.2 mol adduct: 60 mol parts-Terephthalic acid: 47 mol parts-Fumaric acid: 40 mol parts-Dodecenyl succinic anhydride: 15 mol parts / trimellitic anhydride: 3 mol parts Into the reaction vessel equipped with a stirrer, thermometer, condenser and nitrogen gas introduction pipe, other than fumaric acid and trimellitic acid anhydride among the above monomer components were added, In addition, 0.25 parts of tin dioctanoate was added to 100 parts in total of the above monomer components. After reacting at 235 ° C. for 6 hours under a nitrogen gas stream, the temperature was lowered to 200 ° C., and the fumaric acid and trimellitic anhydride were added and reacted for 1 hour. The temperature was further raised to 220 ° C. over 4 hours, and polymerization was performed until the molecular weight was obtained under a pressure of 10 kPa, thereby obtaining a light yellow transparent amorphous polyester resin 1.
The obtained amorphous polyester resin 1 has a glass transition temperature Tg by DSC of 59 ° C., a weight average molecular weight Mw by GPC of 25,000, a number average molecular weight Mn of 7,000, and a softening temperature by a flow tester of 107 ° C. The acid value AV was 13 mgKOH / g.

While maintaining a jacketed 3 liter reaction tank (manufactured by Tokyo Rika Kikai Co., Ltd .: BJ-30N) equipped with a condenser, a thermometer, a water dropping device, and an anchor wing at 40 ° C. in a water circulation thermostat, the reaction tank Into this, a mixed solvent of 160 parts of ethyl acetate and 100 parts of isopropyl alcohol was added, and 300 parts of the amorphous polyester resin 1 was added thereto, and stirred at 150 rpm using a three-one motor to dissolve the oil phase. Obtained. To this stirred oil phase, 14 parts of a 10% aqueous ammonia solution was added dropwise for 5 minutes, mixed for 10 minutes, and 900 parts of ion-exchanged water was further added dropwise at a rate of 7 parts per minute to cause phase inversion. Thus, an emulsion was obtained.
Immediately, 800 parts of the obtained emulsion and 700 parts of ion-exchanged water were put into a 2-liter eggplant flask and set in an evaporator (manufactured by Tokyo Rika Kikai Co., Ltd.) equipped with a vacuum control unit via a trap ball. . While rotating the eggplant flask, the mixture was heated in a hot water bath at 60 ° C., and the solvent was removed by reducing the pressure to 7 kPa while paying attention to bumping. When the solvent recovery amount reached 1,100 parts, the pressure was returned to normal pressure, and the eggplant flask was cooled with water to obtain a dispersion. There was no solvent odor in the obtained dispersion.
The volume average particle diameter D50v of the resin particles in this dispersion was 130 nm. Thereafter, ion exchange water was added to prepare a solid content concentration of 20%, and this was used as an amorphous polyester resin particle dispersion.

(Preparation of crystalline polyester resin particle dispersion)
-1,10-dodecanedioic acid: 50 mol parts-1,9-nonanediol: 50 mol parts The above monomer components are placed in a reaction vessel equipped with a stirrer, thermometer, condenser and nitrogen gas introduction tube. Was replaced with dry nitrogen gas, and 0.25 parts of titanium tetrabutoxide (reagent) was added to 100 parts of the monomer component. After stirring and reacting at 170 ° C. for 3 hours under a nitrogen gas stream, the temperature was further raised to 210 ° C. over 1 hour, the pressure inside the reaction vessel was reduced to 3 kPa, and the stirring reaction was performed for 13 hours under reduced pressure to produce crystals. -Soluble polyester resin 1 was obtained.
The obtained crystalline polyester resin 1 has a melting temperature by DSC of 73.6 ° C., a weight average molecular weight Mw by GPC of 25,000, a number average molecular weight Mn of 10,500, and an acid value AV of 10.1 mgKOH / g. there were.

300 parts of the crystalline polyester resin 1 and methyl ethyl ketone (solvent) in a jacketed 3 liter reaction vessel (Tokyo Rika Kikai Co., Ltd .: BJ-30N) equipped with a condenser, thermometer, water dropping device and anchor blade 160 parts and 100 parts of isopropyl alcohol (solvent) were added, and the resin was dissolved while stirring and mixing at 100 rpm while maintaining the temperature at 70 ° C. in a water circulating thermostat (dissolution preparation step). Thereafter, the stirring speed was set to 150 rpm, the water circulating thermostat was set to 66 ° C., 17 parts of 10% ammonia water (reagent) was added over 10 minutes, and then 7 parts of ion-exchanged water kept at 66 ° C. A total of 900 parts was dropped at a rate of / min to cause phase inversion to obtain an emulsion.
Immediately, 800 parts of the obtained emulsion and 700 parts of ion-exchanged water were placed in a 2-liter eggplant flask, and set in an evaporator (Tokyo Rika Kikai Co., Ltd.) equipped with a vacuum control unit via a trap ball. While rotating the eggplant flask, the mixture was heated in a hot water bath at 60 ° C., and the solvent was removed by reducing the pressure to 7 kPa while paying attention to bumping. When the solvent recovery amount reached 1,100 parts, the pressure was returned to normal pressure, and the eggplant flask was cooled with water to obtain a dispersion. There was no solvent odor in the obtained dispersion.
The volume average particle diameter D50v of the resin particles in this dispersion was 130 nm. Thereafter, ion exchange water was added to prepare a solid content concentration of 20%, and this was used as a crystalline polyester resin particle dispersion.

(Preparation of colorant particle dispersion)
-Cyan pigment (Pigment Blue 15: 3, manufactured by Dainichi Seika Kogyo Co., Ltd.): 10 parts-Anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 2 parts-Ion-exchanged water: 80 parts These components were mixed and dispersed for 1 hour with a high-pressure impact disperser Ultimateizer [HJP30006, manufactured by Sugino Machine Co., Ltd.] to obtain a colorant particle dispersion having a volume average particle size of 180 nm and a solid content of 20%.

(Preparation of release agent particle dispersion)
Paraffin wax (HNP9, manufactured by Nippon Seiki Co., Ltd.): 50 parts Anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku): 2 parts Ion-exchanged water: 200 parts The above ingredients are heated to 120 ° C. The mixture was sufficiently mixed and dispersed with an Ultra Turrax T50 manufactured by IKA, and then dispersed with a pressure discharge homogenizer to obtain a release agent particle dispersion having a volume average particle size of 200 nm and a solid content of 20%.

[Preparation of Toner Particle 1]
Amorphous polyester resin particle dispersion: 700 parts Crystalline polyester resin particle dispersion: 50 parts Colorant particle dispersion: 133 parts Release agent particle dispersion: 100 parts

-Ion-exchanged water: 350 parts The above components are put into a 3 liter reaction vessel equipped with a thermometer, pH meter, and stirrer, and at a temperature of 25 ° C, 1.0% nitric acid is added to adjust the pH to 3.0. Then, 130 parts of an aluminum sulfate aqueous solution was added and dispersed for 6 minutes while dispersing at 5,000 rpm with a homogenizer (IKA Japan Co., Ltd .: Ultra Tarax T50).
Thereafter, a stirrer and a mantle heater are installed in the reaction vessel, and the temperature increase rate is 0.2 ° C./min up to a temperature of 40 ° C. while adjusting the rotation speed of the stirrer so that the slurry is sufficiently stirred. After exceeding the temperature, the temperature was increased at a temperature increase rate of 0.05 ° C./min, and the particle size was measured every 10 minutes with a Coulter Multisizer II (aperture diameter: 50 μm, manufactured by Beckman Coulter, Inc.). When the volume average particle diameter reached 5.0 μm, the temperature was maintained, and 50 parts of amorphous polyester resin particle dispersion liquid was added over 5 minutes.
After maintaining for 30 minutes, the pH was adjusted to 9.0 with 1% aqueous sodium hydroxide solution. Thereafter, the temperature was raised to 90 ° C. at a rate of temperature rise of 1 ° C./min while maintaining the temperature at 98 ° C. while adjusting the pH to 9.0 at every 5 ° C. in the same manner. When the particle shape and surface properties were observed with an optical microscope and a scanning electron microscope (FE-SEM), coalescence of the particles was confirmed at 10.0 hours, and the container was cooled to 30 ° C. for 5 minutes with cooling water. And cooled.

The cooled toner slurry was passed through a nylon mesh having a mesh size of 15 μm to remove coarse powder, and the toner slurry passed through the mesh was filtered under reduced pressure with an aspirator. The toner slurry remaining on the filter paper was crushed as finely as possible by hand, poured into ion-exchanged water 10 times the amount of toner at a temperature of 30 ° C., and stirred and mixed for 30 minutes. Subsequently, it is filtered under reduced pressure with an aspirator, and the toner slurry remaining on the filter paper is crushed as finely as possible by hand, and is poured into ion-exchanged water of 10 times the amount of toner at a temperature of 30 ° C. After stirring and mixing for 30 minutes, The filtrate was filtered under reduced pressure, and the electrical conductivity of the filtrate was measured. This operation was repeated until the electric conductivity of the filtrate reached 10 μS / cm or less, and the toner slurry was washed.
The washed toner slurry was finely pulverized with a wet dry granulator (Comil) and then vacuum dried in an oven at 35 ° C. for 36 hours to obtain toner particles.

  The obtained toner particles had a volume average particle diameter D50 of 5.8 μm and a shape factor of 0.960 (manufactured by Sysmex Corporation, FPIA-3000). When the SEM image of the toner was observed, it had a smooth surface and no defects such as protrusion of the release agent and peeling of the surface layer were observed.

-Production of toner particles 2-
In the production of toner particles 1, the addition of “amorphous polyester resin particle dispersion: 50 parts” was not performed when the volume average particle diameter became 5.0 μm, but the volume average particle diameter became 4.0 μm. Toner particles 2 were produced in the same manner as toner particles 1 except that the time was changed.

<Example 1>
(Production of toner and developer)
Add 1: 1.5 parts of composite particles and 1.5 parts of colloidal silica R972 (manufactured by Nippon Aerosil Co., Ltd.): 1.5 parts of toner particles 1: 100 parts, and mix for 3 minutes at a peripheral speed of 22 m / s using a Henschel mixer. As a result, Toner 1 was obtained.

  The obtained toner 1 and a carrier prepared by the following method were put in a V blender at a ratio of toner: carrier = 5: 95 (mass ratio) and stirred for 20 minutes to obtain developer 1.

In addition, the carrier produced as follows was used.
Ferrite particles (volume average particle size: 50 μm): 100 parts Toluene: 14 parts Styrene-methyl methacrylate copolymer: 2 parts (component ratio: 90/10, Mw = 80000)
Carbon black (R330: manufactured by Cabot Corporation): 0.2 part First, the above components excluding ferrite particles are stirred with a stirrer for 10 minutes to prepare a dispersed coating solution, and then this coating solution and ferrite particles are combined. After putting in a vacuum degassing type kneader and stirring at 60 ° C. for 30 minutes, the carrier was obtained by further depressurizing while heating and degassing and drying.

<Examples 2 to 12>
A toner and a developer were obtained in the same manner as in Example 1 except that the toner particles and composite particles used in Example 1 were changed to those shown in Table 1 below.

<Comparative Example 1>
In Example 1, the composite particles 1 were not added, and only silica particles were externally added (no lubricant particles were externally added) to obtain a toner.
Specifically, 3.0 parts of silica particles (trade name: RY50, manufactured by Nippon Aerosil Co., Ltd., average particle size = 40 nm) are added to 1: 100 parts of toner particles, and the peripheral speed is 22 m / sec using a Henschel mixer. The mixture was mixed for 3 minutes to obtain a toner.
A developer was obtained in the same manner as in Example 1 except that this toner was used.

<Comparative Examples 2-3>
A toner and a developer were obtained in the same manner as in Example 1, except that the composite particles used in Example 1 were changed to those shown in Table 2 below.

<Comparative Example 4>
In Example 1, the toner was obtained by externally adding the lubricant particles and silica particles without adding the composite particles 1.
Specifically, zinc stearate particles (trade name: zinc stearate, 1.5 μm, manufactured by Wako Pure Chemical Industries Ltd., average particle size = 1.5 μm) are added to 1: 100 parts of toner particles. In addition, 1.5 parts of silica particles (trade name: RY50, manufactured by Nippon Aerosil Co., Ltd., average particle size = 40 nm) were added, and mixed with a Henschel mixer at a peripheral speed of 22 m / sec for 3 minutes to obtain a toner.
A developer was obtained in the same manner as in Example 1 except that this toner was used.

<Comparative Example 5>
[Preparation of strontium titanate particles]
After 400 g of titanium oxide and 750 g of strontium carbonate were wet mixed in a ball mill for 5 hours, the dried mixture was molded and fired at 1300 ° C. for 7 hours. This was mechanically pulverized and classified to obtain strontium titanate particles 1. The volume average particle diameter was 4.3 nm, and the shape factor (SF2) was 370.

To 20 parts of the toner particles described above, 0.4 parts by mass of strontium titanate particles as an external additive, 0.2 parts by mass of lubricant particles (zinc stearate particles) used in the composite particles 1, and a composite 2.5 parts by mass of silica particles used for particles 1 were added and mixed for 3 minutes at 2000 rpm with a Henschel mixer to obtain a toner.
A developer was obtained in the same manner as in Example 1 except that this toner was used.

<Evaluation>
−Evaluation of abnormal noise generation−
When an image with a clear separation between the image area and the non-image area is continuously formed and then left to stand, and then the image is formed again in a low temperature environment, abnormal noise caused by vibration of the cleaning blade called chatter The occurrence was evaluated.
Specifically, the developer of each example was accommodated in a developing device of an image forming apparatus “DocuCentre-III C7600 (manufactured by Fuji Xerox)”. Using this image forming apparatus, an image in which the right half is solid and the left half is a non-image part is output continuously on A4 paper as an image in which the image part and the non-image part are clearly separated, and then left overnight. . The following morning, when 10 sheets of solid images were output on A4 paper in a low temperature (10 ° C.) environment, the presence or absence of abnormal noise due to friction between the cleaning blade and the rotationally driven photoconductor (image carrier) was determined as follows. Evaluation was performed according to the evaluation criteria.
・ Evaluation criteria A (◎): No abnormal noise (cannot be heard)
B + (◯ +): Generation of very slight abnormal noise at the start and stop of rotation B (◯): Generation of slight abnormal noise at the start of rotation, and generation of slight abnormal noise at the time of low speed rotation and stop B- (○ −): Minor noise generation at the start and stop of rotation, extremely slight noise generation at low-speed rotation C (△): Minor noise generation at rotation start, stop and low-speed rotation D (x): Low speed at the start of rotation Abnormal noise occurs during both rotation and stop

-Color streak generation evaluation-
When an image in which an image portion and a non-image portion are clearly separated is continuously formed and then left to stand, and then an image is formed again in a low temperature environment, a color streak in a direction perpendicular to the conveyance direction of the recording medium ( The presence or absence of horizontal stripes was evaluated.
Specifically, the presence or absence of color streaks (lateral streaks) in the direction perpendicular to the recording medium conveyance direction was evaluated according to the following evaluation criteria for the image formed last in the abnormal sound generation evaluation.
Evaluation criteria A (◎): No color streaks are confirmed in the image B (◯): Very slight color streaks are confirmed in the image, but acceptable C (△): Minor color streaks are confirmed in the image However, it is acceptable D (x): a clear color streak is confirmed in the image, which is not acceptable

-Image area / non-image area lubricant amount difference evaluation-
In the evaluation of abnormal noise generation, the surface of the photoconductor (image carrier) after being left overnight is observed, and the difference in the amount of lubricant particles in the portion corresponding to the image portion and the portion corresponding to the non-image portion is observed. Were evaluated according to the following evaluation criteria.
The portion corresponding to the image portion and the portion corresponding to the non-image portion of the blade nip portion on the surface of the photoreceptor are respectively tape-transferred, and the magnification is 1000 times using a scanning electron microscope (SEM, manufactured by Hitachi, Ltd .: S-4100). 10 fields of view were observed, the number of lubricant particles was counted, and the number of lubricant particles was compared between a location corresponding to the image area and a location corresponding to the non-image area.
Evaluation criteria A (◎): The range where the number of lubricant particles corresponding to the image portion is ± 10% of the number of lubricant particles corresponding to the non-image portion B (◯): Location corresponding to the image portion The number of lubricant particles is 70% or more and less than 90% of the number of lubricant particles in the portion corresponding to the non-image portion, or more than 110% and 130% or less. C (Δ): lubricant in the portion corresponding to the image portion The number of particles is 50% or more and less than 70%, or more than 130% and 150% or less of the number of lubricant particles in the portion corresponding to the non-image portion. D (x): The number of lubricant particles in the portion corresponding to the image portion is , Less than 50% or more than 150% of the number of lubricant particles in the portion corresponding to the non-image area

In the above table, Formula (1) indicates “1 μm ≦ R _C ≦ (0.45 × R _TN )”, and Formula (2) indicates “R _C <1 μm”.

  From the above results, compared to the comparative example, the present embodiment continuously forms an image in which the image portion and the non-image portion are clearly separated, and after that, when the image is formed again in a low temperature environment. It can be seen that the generation of color stripes (horizontal stripes) is suppressed.

1Y, 1M, 1C, 1K photoconductor (an example of an image carrier)
2Y, 2M, 2C, 2K charging roll (an example of charging means)
3. Exposure device (an example of electrostatic charge image forming means)
3Y, 3M, 3C, 3K Laser beams 4Y, 4M, 4C, 4K Developing device (an example of developing means)
5Y, 5M, 5C, 5K primary transfer roll (an example of primary transfer means)
6Y, 6M, 6C, 6K Photoconductor cleaning device (an example of cleaning means)
8Y, 8M, 8C, 8K Toner cartridge 10Y, 10M, 10C, 10K Image forming unit 11 Screw extruder 12 Barrel 14 Inlet 16 Liquid inlet 18 Outlet 20 Intermediate transfer belt (an example of an intermediate transfer member)
22 Drive roll 24 Support roll 26 Secondary transfer roll (an example of secondary transfer means)
30 Intermediate transfer member cleaning device 107 Photosensitive member (an example of an image holding member)
108 Charging roll (an example of charging means)
109 Exposure apparatus (an example of electrostatic charge image forming means)
111 Developing device (an example of developing means)
112 Transfer device (an example of transfer means)
113 photoconductor cleaning device (an example of cleaning means)
115 Fixing device (an example of fixing means)
116 Attachment rail 118 Opening 117 for exposure 117 Case 200 Process cartridge 300 Recording paper (an example of recording medium)
P Recording paper (an example of a recording medium)
TN toner particle C composite particle

Claims (11)

Toner particles,
Lubricant particles, and composite particles containing reverse polar particles having a charge opposite to that of the lubricant particles, and the reverse polar particles fixed to the surface of the lubricant particles to form a composite,
Including
Among the composite particles, the number ratio (C ₊ : C ₋ ) of the composite particles [C ₊ ] that are positively charged and the composite particles [C ₋ ] that are negatively charged is 30:70 to 70: An electrostatic charge image developing toner in the range of 30. Toner particles,
Lubricant particles, and composite particles containing reverse polar particles having a charge opposite to that of the lubricant particles, and the reverse polar particles fixed to the surface of the lubricant particles to form a composite,
Including
Wherein among the composite particles, the lubricant composite particles [C _M the composite particle coating ratio is less than 40% by reverse polarity particles [C _L] and the coverage of the surface is 40% or more of the particles The toner for developing an electrostatic charge image has a number ratio (C _L : C _M ) to the range of 30:70 to 70:30.   The electrostatic charge image developing toner according to claim 2, wherein in the composite particles, an average coverage by the reverse polarity particles on the surface of the lubricant particles is 20% or more and 60% or less.   When the distribution of the number of coverages in the composite particles is graphed (horizontal axis = coverage, vertical axis = number), there is a peak in both the area where the coverage is less than 40% and the area where the coverage is 40% or more. The toner for developing an electrostatic charge image according to claim 2, which is present. In the composite particles, the ratio of the composite particles satisfying the following formula (1) to the number of the toner particles is 0.006% by number or more and the composite particles satisfying the following formula (2) are satisfied. 5. The electrostatic image developing toner according to claim 1, wherein a ratio with respect to the number of the toner particles is 0.001% by number or less.
Formula (1) 1 μm ≦ R _C ≦ (0.45 × R _TN )
Formula (2) R _C <1 μm
(In the above formulas (1) and (2), R _TN represents the volume average particle size (μm) of the toner particles, and R _C represents the particle size (μm) of the composite particles.)   6. The electrostatic image developing toner according to claim 1, wherein the lubricant particles are zinc stearate particles, and the reverse polarity particles are silica particles. 7.   An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1. Containing the toner for developing an electrostatic charge image according to any one of claims 1 to 6,
A toner cartridge to be attached to and detached from the image forming apparatus. A developing means for containing the electrostatic charge image developer according to claim 7 and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer,
A process cartridge attached to and detached from the image forming apparatus. An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
Development means for containing the electrostatic image developer according to claim 7 and developing the electrostatic image formed on the surface of the image carrier as a toner image by the electrostatic image developer;
Transfer means for transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
Fixing means for fixing the toner image transferred to the surface of the recording medium;
Cleaning means for cleaning the surface of the image carrier by bringing a cleaning blade into contact with the image carrier;
An image forming apparatus comprising: A charging step for charging the surface of the image carrier;
An electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image carrier;
A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer according to claim 7;
A transfer step of transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
A fixing step of fixing the toner image transferred to the surface of the recording medium;
A cleaning step of cleaning the surface of the image carrier by bringing a cleaning blade into contact with the image carrier;
An image forming method comprising: