JP6825288B2 - Toner for static charge image development, static charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Description

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

In electrophotographic image formation, toner is used as an image forming material, and for example, a toner containing toner particles containing a binder resin and a colorant and an external additive added to the toner particles is used. It is widely used.

For example, Patent Document 1 states that "a toner mother particle containing a binder resin, a colorant and a mold release agent, and an external additive are provided, and the external additive contains zinc-containing particles in all the toner particles. The number of free zinc-containing particles is 0.2% by number or more and 1.0 number% or less, the average particle size of the number of free zinc-containing particles is 1.0 μm or more and 3.0 μm or less, and the free zinc-containing particles "Toner for developing an electrostatic charge image having an average circularity of 0.2 or more and 0.6 or less" is disclosed.

Further, Patent Document 2 states, "A toner for developing an electrostatic charge image containing toner particles and an external additive, which is a fatty acid metal salt in which the external additive is formed on the surface of core material particles in supercritical carbon dioxide. A toner for developing an electrostatic charge image, which is an external additive having a coating layer containing the above-mentioned substances, is disclosed.

Further, Patent Document 3 describes a toner matrix 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, and fatty acids and fatty acid metals. Toners containing salt-treated inorganic fine powders "are disclosed.

Further, Patent Document 4 includes "colored particles containing a binder resin and a colorant, and composite particles containing lubricant particles and abrasive particles and at least a part of the abrasive particles is exposed on the surface." "Toner for developing an electrostatic latent image" is disclosed.

JP-A-2010-185999 Japanese Unexamined Patent Publication No. 2014-134594 Japanese Unexamined Patent Publication No. 2003-84486 Japanese Unexamined Patent Publication No. 2008-145749

Conventionally, when a toner for static charge image development 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 to stand in a low temperature environment. When the image was formed again, color streaks (horizontal streaks) sometimes occurred in the direction orthogonal to the transport direction of the recording medium.
Therefore, the first problem of the present invention is to replace or in addition to the lubricant particles, the reverse pole particles having a chargeability opposite to that of the lubricant particles are fixed to the surface of the lubricant particles to form a composite. The number ratio (C ₊ / C ₋ ) of the positively charged complex particles [C ₊ ] to the negatively charged complex particles [C ₋ ] using the complex particles formed is less than 30/70, or It is an object of the present invention to provide a toner for static charge image development in which the generation of color streaks is suppressed as compared with the case where the amount exceeds 70/30.
A second object of the present invention is to replace or in addition to the lubricant particles, the reverse pole particles having a chargeability opposite to that of the lubricant particles are fixed to the surface of the lubricant particles to form a composite. Complex particles [ _CM ] using the complex particles formed and having a coverage of less than 40% by the reverse electrode particles on the surface of the lubricant particles, wherein the coverage of the composite particles [ _CL ] is 40% or more. number ratio _(C L / C _M) is less than 30/70 for, or compared to the case where it is beyond 70/30 is to provide a toner for developing an electrostatic image generated is suppressed of the color streaks.

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

The invention according to < 1 > is
Toner particles and
A composite particle containing a lubricant particle and a reverse pole particle having a charge opposite to that of the lubricant particle, and the reverse pole particle is fixed to the surface of the lubricant particle to form a composite.
Including
Among the complex particles, the number ratio (C ₊ : C ₋ ) of the positively charged complex particles [C ₊ ] and the negatively charged complex particles [C ₋ ] is 30:70 to 70 :. Toner for static charge image development in the range of 30.

The invention according to < 2 > is
Toner particles and
A composite particle containing a lubricant particle and a reverse pole particle having a charge opposite to that of the lubricant particle, and the reverse pole particle is fixed to the surface of the lubricant particle 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 ] and the number ratio _(C L: C _M) toner for electrostatic image development in the range of 30:70 to 70:30.

The invention according to < 3 > is
The toner for static charge image development according to < 2 > , wherein the average coverage of the composite particles by the antipolar particles on the surface of the lubricant particles is 20% or more and 60% or less.

The invention according to < 4 > is
When the number distribution of the coverage in the composite particles is graphed (horizontal axis = coverage, vertical axis = number), peaks occur in both the region with a coverage of less than 40% and the region with a coverage of 40% or more. The toner for static charge image development according to < 2 > or < 3 > that exists.

The invention according to < 5 > is
Among the composite particles, the ratio of the composite particles satisfying the condition of the following formula (1) to the number of the toner particles is 0.006% by number or more, and the composite particles satisfying the condition of the following formula (2). The toner for static charge image development according to any one of < 1 > to < 4 > , wherein the ratio to the number of the toner particles is 0.001% by number or less.
Equation (1) 1 μm ≤ _RC ≤ (0.45 × R _TN )
Equation (2) _RC <1 μm
(In the above formulas (1) and (2), R _TN represents the volume average particle diameter (μm) of the toner particles, and _RC represents the particle diameter (μm) of the composite particles.)

The invention according to < 6 > is
The toner for static charge image development according to any one of < 1 > to < 5 > , wherein the lubricant particles are zinc stearate particles and the antipolar particles are silica particles.

The invention according to < 7 > is
A static charge image developer containing the toner for static charge image development according to any one of < 1 > to < 6 > .

The invention according to < 8 > is
The toner for static charge image development according to any one of < 1 > to < 6 > is housed,
A toner cartridge that is attached to and detached from the image forming device.

The invention according to < 9 > is
A developing means for accommodating the electrostatic charge image developing agent according to < 7 > and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developing agent is provided.
A process cartridge that is attached to and detached from the image forming device.

The invention according to < 10 > is
Image holder and
A charging means for charging the surface of the image holder and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
A developing means for accommodating the electrostatic charge image developer according to < 7 > and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic image developer.
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
A cleaning means for cleaning the surface of the image holder by bringing the cleaning blade into contact with the image holder.
An image forming apparatus comprising.

The invention according to < 11 > is
The charging process that charges the surface of the image holder,
A static charge image forming step of forming a static charge image on the surface of the charged image holder, and
A developing step of developing an electrostatic charge image formed on the surface of the image holder as a toner image by using the electrostatic charge image developer according to < 7 > .
A transfer step of transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing step of fixing the toner image transferred to the surface of the recording medium, and
A cleaning step of bringing a cleaning blade into contact with the image holder to clean the surface of the image holder.
An image forming method having.

According to the invention according to < 1 > or < 6 > , the toner particles and the reverse pole particles having a chargeability opposite to that of the lubricant particles are fixed to the surface of the lubricant particles to form a composite. The number ratio (C ₊ / C ₋ ) of the positively charged complex particles [C ₊ ] to the negatively charged complex particles [C ₋ ] including the body particles is less than 30/70, or 70. Compared to the case where it exceeds / 30, when an image in which the image portion and the non-image portion are clearly separated is continuously formed, and then the image is formed again in a low temperature environment after being left to stand, it is orthogonal to the transport direction of the recording medium. Provided is a toner for static charge image development in which color streaks generated in the direction of the particles are suppressed.
According to the invention according to < 2 > or < 6 > , the toner particles and the reverse pole particles having a chargeability opposite to that of the lubricant particles are fixed to the surface of the lubricant particles to form a composite. For composite particles [C _M ] containing body particles and having a coverage of less than 40% by the reverse electrode particles on the surface of the lubricant particles, the coverage of the composite particles [ _CL ] is 40% or more. number ratio _(C L _/ C _M) is less than 30/70, or compared to the case where it is beyond 70/30, low temperature after then left image area and the non-image area is formed continuously clearly separate images Provided is a static charge image developing toner in which color streaks generated in a direction orthogonal to a transport direction of a recording medium are suppressed when an image is formed again in an environment.
According to the invention according to < 3 > , the image portion and the non-image portion are clearly separated as compared with the case where the average coverage of the lubricant particles by the antipolar particles on the surface is less than 20% or more than 60%. Provided is a static charge image developing toner in which color streaks generated in a direction orthogonal to a transport direction of a recording medium are suppressed when an image is continuously formed and then left to stand and then an image is formed again in a low temperature environment.
According to the invention according to < 4 > , there is only one peak when the number distribution of the coverage by the antipolar particles on the surface of the lubricant particles is graphed (horizontal axis = coverage, vertical axis = number). Compared to the case, 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 generated in a direction orthogonal to the transport direction of the recording medium. A toner for static charge image development in which streaks are suppressed is provided.
According to the invention according to < 5 > , the image portion and the non-image portion are different from each other as compared with the case where the ratio of the composite particles satisfying the condition (1) to the number of toner particles is less than 0.006 number%. Toner for static charge image development that suppresses color streaks that occur in the direction orthogonal to the transport direction of the recording medium when a clearly separated image is continuously formed and then left to stand and then the image is formed again in a low temperature environment. Provided.

According to the invention according to < 7 > , < 8 > , < 9 > , < 10 > , or < 11 > , the toner particles and the surface of the lubricant particles have a chargeability opposite to that of the lubricant particles. The number ratio (C ₊ ) of the positively charged complex particles [C ₊ ] to the negatively charged complex particles [C ₋ ], including the complex particles to which the inverse polar particles are fixed to form a complex. / C ₋ ) is less than 30/70 or more than 70/30, and the coverage of the composite particles [ _CL ] on the surface of the lubricant particles by the reverse electrode particles is less than 40%. 40% or more the number ratio composite particles _{[C M] (C} L / _{C M)} is less than 30/70, or compared to the case where it is beyond 70/30, an image area and the non-image area is clearly divided Static charge image developer, toner cartridge, process that suppresses color streaks that occur in the direction orthogonal to the transport direction of the recording medium when the images are continuously formed and then left to stand and then the images are formed again in a low temperature environment. Cartridges, image forming devices, or image forming methods are provided.

It is an image which shows an example of the complex particle used in this embodiment. It is an image which shows an example of the complex particle used in this embodiment. It is the schematic for demonstrating the preferable particle diameter of the composite particle in this embodiment. It is a figure explaining the state of a screw about an example of the screw extruder used for manufacturing the toner which concerns on this embodiment. It is a schematic block diagram which shows the image forming apparatus which concerns on this 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 by showing an embodiment as an example.

<Toner for static charge image development>
The toner for static charge image development according to the present embodiment (hereinafter, also simply referred to as “toner”) includes toner particles and composite particles. The composite particles contain the lubricant particles and the reverse pole particles having a chargeability opposite to that of the lubricant particles, and the reverse pole particles are fixed to the surface of the lubricant particles to form a composite. Form a body.

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

Further, the toner according to the second embodiment of the present embodiment is a composite particle [ _CL ] in which the coverage of the lubricant particles on the surface of the lubricant particles by the antipolar particles is less than 40%. and the number ratio of the coverage is 40% or more in which composite particles _{[C M] (C} L: _{C M)} 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 separated is continuously formed, and then the image is formed again in a low temperature environment after being left to stand, the direction is orthogonal to the transport 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 streaks (horizontal streaks) is suppressed. Further, according to the toner according to the second embodiment, the generation of the color streaks (horizontal streaks) is suppressed.
The reason is presumed 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 holder. Further, from the viewpoint of suppressing the wear of the image holder due to the contact with the cleaning blade, the lubricant particles are added to the toner.
However, when a toner containing toner particles and lubricant particles is used, an image in which the image portion and the 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%) is used. After forming a series of images (for example, 1000 images in a row) and then leaving the image (for example, leaving it overnight), a low temperature environment (for example, a winter morning) may be mentioned. When an image is formed under (environment), color streaks (horizontal streaks) may occur in a direction orthogonal to the transport direction of the recording medium.

It is considered that the chargeability of the lubricant particles contributes to the generation of the color streaks (horizontal streaks). For example, when the toner particles are negatively charged and positively charged particles such as fatty acid metal salt are used as the lubricant particles, the lubricant particles are supplied to the surface of the image holder. Will be supplied more to the non-image area. Further, when negatively charged particles are used as the lubricant particles, the amount of the lubricant particles supplied to the image portion is larger. 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 or the region corresponding to the non-image portion of the image holder. It is in a state where it is present in a large amount and the lubricant particles are not present or only a small amount is present in the other region. Then, when the image is formed in a low temperature environment, that is, in an environment where the hardness of the cleaning blade becomes harder and the contact pressure becomes high after being left in that state, the lubricant particles do not exist in the other region or Since only a small amount is present, the frictional force with the cleaning blade in this area increases. Then, the increase in the frictional force causes vibration of the cleaning blade called chatter (that is, the cleaning blade is repeatedly pulled in the driving direction of the image holder by the frictional force and returns to the original position again), and the cleaning blade holds the image. When the body is pulled in the driving direction, the cleanability deteriorates and the toner or the like slips through. It is considered that the toner or the like that has slipped through is generated as color streaks (horizontal streaks) in the image.

On the other hand, the present embodiment includes composite particles in which reverse pole particles having a chargeability opposite to that of the lubricant particles are fixed to the surface of the lubricant particles to form a composite. Then, in the toner according to the first embodiment, among the composite particles, the number ratio (C ₋ ) of the positively charged composite particles [C ₊ ] and the negatively charged composite particles [C ₋ ]. ₊ : C ₋ ) is the above range.
The fact that the number ratio (C ₊ : C ₋ ) satisfies the above range means that the composite particles that are easily supplied to the image portion and the composite particles that are easily supplied to the non-image portion are mixed, and either composite is used. It can be said that particles are also an indicator that their 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 first embodiment, the region corresponding to the image portion of the image holder and Complex particles are likely to be supplied to both of the regions corresponding to the non-image areas. As a result, even when the above image is continuously formed and then left to stand to form the image again in a low temperature environment, the vibration of the cleaning blade called chatter is suppressed, the slip-through of toner and the like is reduced, and the color streaks in the image are reduced. It is considered that the occurrence of (horizontal streaks) is suppressed.

Further, in the toner according to the second embodiment, among the composite particles, the composite particles [ _CL ] in which the coverage by the antipolar particles on the surface of the lubricant particles is less than 40% and the coverage is 40. the number ratio of the composite particles _{[C M]} or more percent _(C L: _{C M)} is in the above range.
The fact that the number ratio ( _CL : _CM ) satisfies the above range means that the complex particles in which the surface of the lubricant particles is covered with a relatively small amount of antipolar particles and a relatively large amount of antipolar particles are present. It means that the covering complex particles are mixed, that is, the complex particles having a relatively positive charge and the complex particles having a negative charge are mixed. Moreover, it can be said that both of these complex particles are indicators that the content thereof 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, the region corresponding to the image portion of the image holder and the region corresponding to the image portion can be obtained. Complex particles are likely to be supplied to both of the regions corresponding to the non-image areas. As a result, even when the above image is continuously formed and then left to stand to form the image again in a low temperature environment, the vibration of the cleaning blade called chatter is suppressed, the slip-through of toner and the like is reduced, and the color streaks in the image are reduced. It is considered that the occurrence of (horizontal streaks) is suppressed.

The details of the toner according to this embodiment will be described below.

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

(Complex particles)
The composite particles contain the lubricant particles and the reverse pole particles having a chargeability opposite to that of the lubricant particles, and the reverse pole particles adhere to the surface of the lubricant particles to form a composite. ..

Here, "sticking" means that the monopole particles are attached to the surface of the lubricant particles to the extent that they are difficult to separate, and specifically, even after the following ultrasonic treatment is performed. Indicates that the monopole particles are present on the surface of the lubricant particles.
-Sonication-
When added to the toner, first, 4 g of the toner is added to 100 mL of a 0.2 mass% aqueous solution of a 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 (manufactured by Sakuma Seisakusho Co., Ltd., trade name: M201-IVD) for 2 minutes at 3000 rpm to separate toner particles, other external additives, etc., and filtered to form composite particles. Get a sample.
Next, 4 g of the complex particle sample was added to 100 mL of a 0.2 mass% aqueous solution of a Triton solution (polyoxyethylene octylphenyl ether, manufactured by Wako Pure Chemical Industries, Ltd.), stirred and dispersed, and then ultrasonic waves were used. Using the device (manufactured by Nippon Seiki Seisakusho Co., Ltd., trade name: US-300TCVP), ultrasonic vibration with an output of 20 W and a frequency of 20 kHz is applied for 10 minutes. This is treated with a centrifuge (manufactured by Sakuma Seisakusho Co., Ltd., trade name: M201-IVD) for 30 minutes under the condition of 10000 rpm, and the reverse electrode particles desorbed by ultrasonic vibration are separated and filtered to form a composite. Get the particles.
The obtained composite particles are observed with a scanning electron microscope (SEM, manufactured by Hitachi, Ltd .: S-4100), and the reverse polar particles existing on the surface of the lubricant particles are regarded as fixed reverse polar particles.

-Measuring method of coverage-
The "coverage" of the composite particles (the coverage of the antipolar particles fixed on the surface of the lubricant particles) is determined by the scanning electron microscope (SEM, manufactured by Hitachi, Ltd.) after the above ultrasonic treatment. : From the image taken with S-4100), the area of the region of the composite particles where the reverse pole particles are not attached to the surface of the lubricant particles and the area of the reverse pole particles attached to the lubricant particles are measured. This is done by calculating the coverage ratio from here.
Further, the average coverage is measured by measuring the coverage of any 100 composite particles by the above method and calculating the average value thereof.

· 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 positively charged composite particles [C ₊ ] and the negatively charged composite particles [C ₋ ]. _- ) Is in the range of 30:70 to 70:30. When the number ratio (C ₊ : C ₋ ) is within the above range, an image in which the image portion and the non-image portion are clearly separated is continuously formed, and then the image is formed again in a low temperature environment after being left to stand. Color streaks (horizontal streaks) that occur in the direction orthogonal to the transport 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 further preferably in the range of 45:55 to 55:45.

The "negative chargeability" and "positive chargeability" mean whether the composite particles are negatively (-) or positively (+) charged when the toner is charged in the developing apparatus. To do.

Here, a method of calculating the number ratio (C ₊ : C ₋ ) of the positively charged complex particles [C ₊ ] and the negatively charged complex particles [C ₋ ] will be described.
2.0 g of the composite particles and 28.0 g of the carrier were placed in a 60 mL wide-mouthed stopper bottle and stirred for 2 minutes, and the contents were connected to a high-voltage power source (trade name: FLUKE415B, manufactured by FLUKE) to generate a voltage of 200 V. It is passed between a pair of applied plates (steel, clearance 3 mm). After removing the electrode plate and removing the carriers adhering to it with an air blow, the surface deposits on each of the positive electrode plate and the negative electrode plate are magnified using a scanning electron microscope (SEM, manufactured by Hitachi, Ltd .: S-4100). 10 fields of view were taken at 1000 times, the number of composite particles was counted, and the number of composite particles on the negative electrode plate was [C ₊ ] and the number of complex particles on the positive electrode plate was [C ₋ ]. Calculate the ratio (C ₊ : C ₋ ).

The method for controlling the number ratio (C ₊ : C ₋ ) of the composite particles within the above range is not particularly limited, but the coverage of the antipolar particles fixed on the surface of the lubricant particles is increased. There is a method of adjusting the distribution. That is, the surface of the lubricant particles is mixed with the complex particles coated with more antipolar particles and the complex particles coated with less antipolar particles, and the mixing ratio is adjusted. , The number ratio (C ₊ : C ₋ ) is controlled within the above range.
Incidentally, in particular the number ratio of the composite particles in coverage by the reverse polarity particles is less than 40% of composite particles [C _L] and coverage of the surface is 40% or more of the lubricant particles [C _M] (C _By setting _L : _CM ) to the above 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 ( _CL : _CM )
In the toner according to the second embodiment, among the composite particles, the composite particles [ _CL ] having a coverage of less than 40% due to the fixed opposite pole particles on the surface of the lubricant particles and the composite particles [ _CL ] have a coverage of 40% or more. the number ratio of the composite particles _{[C M]} is _(C L: _{C M)} is in the range of 30:70 to 70:30.
For example, images of composite particles in which silica particles, which are an example of antipolar particles, adhere to the surface of zinc stearate, which is an example of lubricant particles, to form a composite are shown in FIGS. 1A and 1B. Note that FIG. 1A is an image of the composite particles having a coverage of 15% by the silica particles, and FIG. 1B is an image of the composite particles having a coverage of 50% by the silica particles.
When the number ratio ( _CL : _CM ) is within the above range, an image in which the image portion and the non-image portion are clearly separated is continuously formed, and then the image is formed again in a low temperature environment after being left to stand. Color streaks (horizontal streaks) that occur in the direction orthogonal to the transport direction of the recording medium are suppressed.
Note that the number ratio _(C L: C _M) is more preferably within a range of 40:60 to 60:40, more preferably in the range of 45:55 to 55:45.

The number ratio of the composite particle coating ratio is less than 40% [C _L] complexes particle coating ratio is 40% or more [C _M]: calculated for (C L _{C M)} is any By measuring the coverage of 100 composite particles by the method described above and counting the number of composite particles having a coverage of less than 40% and the number of complex particles having a coverage of 40% or more. Will be done.

A method of controlling the number ratio ( _CL : _CM ) of the composite particles within the above range will be described.
First, the method of including the composite particles in which the inverse pole particles are fixed on the surface of the lubricant particles as an external additive in the toner is not particularly limited, but is externally added to the toner particles, for example. The previous lubricant particles and the reverse pole particles are mixed in advance and fixed by stirring while applying a shearing force, and the lubricant particles (composite particles) in which the reverse pole particles are fixed to the surface are attached to the toner particles. An external method is mentioned as a preferable method.

Further, the method of controlling the number ratio ( _CL : _CM ) 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 First, a relatively small amount of lubricant particles and a relatively small amount of antipolar particles (adjusted in an amount so that the average coverage is less than 40%). And are mixed and stirred while applying a shearing force, and the antipolar particles are fixed to prepare composite particles having an average coverage of less than 40%. Separately from this, the lubricant particles and a relatively large amount of antipolar particles (the amount of which is adjusted so that the average coverage is 40% or more) are mixed and stirred while applying a shearing force, and the antipolar particles are applied. By fixing the particles, complex particles having an average coverage of 40% or more are prepared. A method of controlling the number ratio ( _CL : _CM ) within the above range by externally adding both of them to the toner particles and adjusting the addition ratio of both of them can be mentioned.
It should be noted that the method is not limited to the method of preparing two types of composite particles having different average coverages as described above and externally adding both of them to the toner particles, and preparing three or more types of composite particles having different average coverages. The number ratio ( _CL : _CM ) may be controlled within the above range by externally adding these to the toner particles and adjusting the addition ratio thereof.

According to the method (1) above, in the number distribution of the coverage in the composite particles, the number distribution of the coverage in the composite particles having two or more peaks (maximum values), that is, the composite particles is graphed (horizontally). Toner with composite particles externalized with peaks (maximum values) in both the region with a coverage of less than 40% and the region with a coverage of 40% or more when axis = coverage, vertical axis = number) Can be produced.

Here, a configuration in which a peak (maximum value) exists in both a region having a coverage of less than 40% and a region having a coverage of 40% or more will be described in more detail. Usually, it is not easy to precisely control the distribution of the coverage by the monopole particles on the surface of the lubricant particles. Therefore, the “number distribution of coverage” described in the present specification refers to a case where a rough number distribution of coverage is taken. For example, it represents "distribution when the number (total number) is put together for each 10% interval of coverage", that is, coverage 0% or more and less than 10%, 10% or more and less than 20%, 20% or more and less than 30%, 30%. 40% or more, 40% or more and less than 50%, 50% or more and less than 60%, 60% or more and less than 70%, 70% or more and less than 80%, 80% or more and less than 90%, and 90% or more and 100% or less " When the number of complex particles that fall within the range is calculated and plotted on a graph (horizontal axis = coverage, vertical axis = number), the coverage of the region is less than 40% and the coverage is 40% or more. There is an aspect that a peak (maximum value) exists in each of them.

By making the composite particles have peaks in both the region having a coverage of less than 40% and the region having 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 with the case where the complex particles do not exist, more complex particles that are easily supplied to the image portion and more complex particles that are easily supplied to the non-image portion are more likely to exist. As a result, when 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, the color generated in the direction orthogonal to the transport direction of the recording medium. It is easier to suppress streaks (horizontal streaks).

(2) Method of mixing in a batch Lubricant particles and antipolar particles are mixed and agitated while applying a shearing force to fix them. At that time, for example, by adjusting the following items, the number ratio ( _CL : C) A method of controlling _M ) to the above range can be mentioned. Then, the toner according to the present embodiment is obtained by externally adding the above-mentioned composite particles having an adjusted number ratio ( _CL : _CM ) to the toner particles.
・ Adjust the amount of reverse electrode particles with respect to the lubricant particles ・ Adjust the shearing force and stirring time during stirring ・ Divide the lubricant particles into multiple parts and add them at different times to adjust the division amount and number of divisions of the agent. To do

The average coverage of the entire composite particles 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.
When the average coverage of the entire composite particles is within the above range, the distribution of the coverage in the composite particles is balanced, that is, the composite particles that are 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, when 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, a color streak occurs in a direction orthogonal to the transport direction of the recording medium. It is easier to suppress (horizontal streaks).

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

On the other hand, in the present embodiment, in order to clean the residual toner and the like remaining without being transferred to the surface on the downstream side (downstream side in the image holder driving direction) from the contact position of the image holder with the transfer means, the image is imaged. A cleaning blade is placed on the surface of the retainer. A deposit of toner particles (so-called toner dam) is formed in the region on the upstream side (upstream side in the image holder driving direction) of the contact portion of the cleaning blade with the image holder, and further inside the toner dam, that is, the cleaning blade. On the contact portion side with the image holder, a deposit (so-called external agent dam) due to an external additive having a diameter smaller than that of the toner particles is formed. The formation of both deposits results in good cleaning with a cleaning blade. Therefore, it is preferable that the particle size of the composite particles is such that it easily penetrates inside (contact portion side) of the toner dam to form an external additive dam.
Specifically, assuming that the contact angle α between the cleaning blade and the image holder is 45 °, for example, as shown in FIG. 2, the particle size of the composite particles C that can enter the contact portion side of the toner dam. (2 × r) is 0.45 times or less with respect to the particle size (2 × R) of the toner particles TN. Therefore, the particle size of the composite particles is preferably "0.45 x R _TN " (R _TN : volume average particle size of the toner particles) or less.

From the above points, from the viewpoint of improving the cleanability, the ratio of the composite particles satisfying the condition of the following formula (1) to the number of toner particles is preferably 0.006% by number or more, more preferably 0. 010 Number% or more.
Further, the upper limit value is preferably 0.1% by number or less, more preferably 0.08% by number or less, because if the composite particles are excessive, it easily slips through the cleaning blade.
Equation (1) 1 μm ≤ _RC ≤ (0.45 × R _TN )
(In the above formula (1), R _TN represents the volume average particle diameter (μm) of the toner particles, and _RC represents the particle diameter (μm) of the composite particles.)

Further, from the viewpoint of suppressing the slip-through of the composite particles by the cleaning blade, the ratio of the composite particles satisfying the condition of the following formula (2) to the number of toner particles is preferably 0.001 by number% or less. It is preferably 0.0008 number% or less, and the smaller the amount, the more preferable.
Equation (2) _RC <1 μm
(In the above formula (2), _RC represents the particle size (μm) of the complex particles.)

The particle size of the composite particles ( _RC (μm) / particle size of the individual composite particles) is determined by scanning electron microscopy (SEM, Inc.) for the composite particles obtained by performing the above-mentioned ultrasonic treatment. ) Take an image with Hitachi, Ltd .: S-4100), take this image into an image analyzer (LUZEXIII, manufactured by Nireco Co., Ltd.), measure the area of each particle by image analysis of primary particles, and measure this area value. Calculate the equivalent circle diameter from.

The method for measuring the volume average particle size ( _RTN (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 antipolar particles to be fixed.

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

-Lubricant particles As the composite particles, either negatively charged lubricant particles N or positively charged lubricant particles P may be used. Here, "negative chargeability" and "positive chargeability" mean negative (-) when the toner is charged when the lubricant particles are not present as composite particles but alone in the developing apparatus. It means whether it is charged positively or positively (+).

Examples of the positively charged lubricant particles P include fatty acid metal salt particles and the like. Fatty acid metal salt particles are salt particles composed of fatty acid and metal.
The fatty acid may be either a saturated fatty acid or an unsaturated fatty acid. Examples of the fatty acid have 10 or more and 25 or less carbon atoms (preferably 12 or more and 22 or less). The carbon number of the fatty acid includes the carbon of the carboxy group.
Examples of the fatty acid include saturated fatty acids such as bechenic acid, stearic acid, palmitic acid, myristic acid and lauric acid; unsaturated fatty acids such as oleic acid, linoleic acid and ricinolic 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, zinc is preferable as the metal.

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, and stearic acid. Metal salts of stearic acid such as strontium, cobalt stearate, sodium stearate; metal salts of palmitate such as zinc palmitate, cobalt palmitate, copper palmitate, magnesium palmitate, aluminum palmitate, calcium palmitate; lauric acid Metal salts of laurate such as zinc, manganese laurate, calcium laurate, iron laurate, magnesium laurate, aluminum laurate; zinc oleate, manganese oleate, iron oleate, aluminum oleate, copper oleate, oleic acid Metal salts of oleic acid such as magnesium and calcium oleate; metal salts of stearic acid such as zinc linoleate, cobalt linoleate, calcium linoleate; metal salts of stearic acid such as zinc ricinolate and aluminum ricinolate; etc. Particles can be mentioned.
Among the fatty acid metal salt particles, each particle of a metal salt of stearic acid or a metal salt of lauric acid is preferable, each particle of zinc stearate or zinc laurate is more preferable, and zinc stearate particles are further preferable.

The average particle size of the positively charged lubricant particles P is preferably 0.5 μm or more and 3.0 μm or less, more preferably 0.6 μm or more and 2.9 μm or less, and further preferably 0.7 μm or more. It is 85 μm or less.
The average particle size of the lubricant particles is measured according to the method for measuring inorganic particles described later.

Examples of the negatively charged lubricant particles N include fluororesin particles, silicone resin, inorganic particles, wax resin particles, and the like.
Examples of the fluororesin particles include polytetrafluoroethylene (PTFE, “tetrafluoroethylene resin”), perfluoroalkoxyfluororesin, polychlorotrifluoroethylene, polyfluorovinylidene, polydichlorodifluoroethylene, and 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 charged lubricant particles N is preferably 0.5 μm or more and 3.0 μm or less, more preferably 0.6 μm or more and 2.9 μm or less, and further preferably 0.7 μm or more. It is 85 μm or less.
The average particle size of the lubricant particles is measured according to the method for measuring inorganic particles described later.

-Reverse pole particles For the reverse pole particles, use chargeable particles opposite to the lubricant particles used.
Examples of the negatively charged antipolar 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. Further, the silica particles may be particles produced from a silicon compound such as water glass or alkoxysilane, or may be particles obtained by crushing quartz. Specifically, silica particles. Examples thereof include solgel silica particles, aqueous colloidal silica particles, alcoholic silica particles, fumed silica particles obtained by the vapor phase method, and molten silica particles. Among them, as the silica particles, sol-gel silica particles are preferable from the viewpoint of satisfying the following characteristics.

Further, the silica particles are preferably monodisperse and spherical. The monodisperse spherical silica particles are dispersed on the surface of the lubricant particles in a nearly uniform state, and stable chargeability can be obtained.
Here, as the definition of monodisperse, the standard deviation with respect to the average particle size including the agglomerates can be discussed, and the volume average particle size D50 × 0.22 or less is preferable as the standard deviation. Further, the definition of spherical shape 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 size of the inorganic particles (particularly silica particles) is measured by the following method.
The primary particles of the inorganic particles were observed with a scanning electron microscope SEM (Scanning Electron Microscope) device (Hitachi Co., Ltd .: S-4100) to take an image, and this image was taken by an image analyzer (LUZEXIII, Co., Ltd.). ) Taken into (Nireco), measure the area of each particle by image analysis of the primary particle, and calculate the equivalent circle diameter from this area value. This circle-equivalent diameter is calculated for 100 inorganic particles. Then, the 50% diameter (D50) of the obtained volume-based cumulative frequency of the equivalent circle diameter is defined as the average primary particle diameter (average equivalent circle diameter D50) of the inorganic particles. In the electron microscope, the magnification is adjusted so that about 10 or more and 50 or less inorganic particles are captured in one field of view, and the equivalent circle diameter of the primary particles can be obtained by combining the observations of a plurality of fields of view.

The surface of the inorganic particles listed as the polar particles may be hydrophobized. The hydrophobizing treatment is performed, for example, by immersing the inorganic particles in a hydrophobizing agent. The hydrophobizing agent is not particularly limited, and examples thereof include a silane-based coupling agent, a silicone oil, a titanate-based coupling agent, and an aluminum-based coupling agent. These may be used alone or in combination of two or more.
The amount of the hydrophobizing agent is usually, for example, 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic particles.

Examples of the positively charged antipolar 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. Further, the silica particles may be particles produced from a silicon compound such as water glass or alkoxysilane, or particles obtained by pulverizing quartz.
Specifically, examples of the silica particles include solgel silica particles, aqueous colloidal silica particles, alcoholic silica particles, fumed silica particles obtained by the vapor phase method, and molten silica particles. Among them, as the silica particles, sol-gel silica particles are preferable from the viewpoint of satisfying the following characteristics.

Further, the silica particles are preferably monodisperse and spherical. The monodisperse spherical silica particles are dispersed on the surface of the lubricant particles in a nearly uniform state, and stable chargeability can be obtained. Here, the definition of monodisperse 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 examples of the surface treatment agent include hexamethyldisilazane, polydimethylsiloxane, octyltriethoxysilane and the like.
Of these, hexamethyltidirazane is more preferable.

The average particle size of the positively charged antipolar 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 size is measured according to the measuring method for the inorganic particles.

-Content The content of the composite particles is 0.8% by mass or more and 2.0% by mass or less with respect to the amount of the toner particles from the viewpoint of ensuring lubricity and suppressing filming in the image holder. It is more preferable, 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 are composed of, for example, a binder resin,, if necessary, a colorant, a mold release agent, and other additives.

-Bound resin-
Examples of the binder resin include styrenes (for example, styrene, parachlorostyrene, α-methylstyrene, etc.) and (meth) acrylic acid esters (for example, 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 (eg, acrylonitrile, Methacrylic acid, 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, butadiene, etc.), etc. Examples thereof include a homopolymer of the above-mentioned monomer and a vinyl-based resin composed of a copolymer obtained by combining two or more kinds of these monomers.
Examples of the binder resin include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosins, mixtures of these with the vinyl resins, or these. Examples thereof include a graft polymer obtained by polymerizing a vinyl-based monomer in the coexistence.
These binder resins may be used alone or in combination of two or more.

As the binder resin, a polyester resin is suitable.
Examples of the polyester resin include known amorphous polyester resins. As the polyester resin, a crystalline polyester resin may be used in combination with the amorphous polyester resin. However, the crystalline polyester resin may be used in a range in which the content is 2% by mass or more and 40% by mass or less (preferably 2% by mass or more and 20% by mass or less) with respect to the total binder resin.

The "crystallinity" of the resin means that in differential scanning calorimetry (DSC), it has a clear endothermic peak rather than a stepwise endothermic change, and specifically, the temperature rise rate is 10 (° C.). It means that the half width of the endothermic peak when measured at / min) is within 10 ° C.
On the other hand, "amorphous" of the resin means that the half width exceeds 10 ° C., shows a stepwise change in endothermic amount, or does not show a clear endothermic peak.

-Amorphous polyester resin Examples of the amorphous polyester resin include a condensed polymer of a polyvalent carboxylic acid and a polyhydric alcohol. As the amorphous polyester resin, a commercially available product may be used, or a synthetic resin may be used.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (for example, 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 acid (eg cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acid (eg, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), these anhydrides, or their lower grades (eg, 1 or more carbon atoms). (5 or less) Alkyl ester can be mentioned. Among these, as the polyvalent carboxylic acid, for example, an aromatic dicarboxylic acid is preferable.
As the polyvalent carboxylic acid, a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
The polyvalent carboxylic acid may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include aliphatic diols (eg ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (eg cyclohexanediol, cyclohexanedimethanol, etc. Hydrogenated bisphenol A, etc.), aromatic diols (for example, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, etc.) can be mentioned. Among these, as the polyhydric alcohol, for example, an aromatic diol and an alicyclic diol are preferable, and an aromatic diol is more preferable.
As the polyhydric alcohol, a trihydric or higher polyhydric alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
The polyhydric alcohol may be used alone or in combination of two or more.

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 obtained from the DSC curve obtained by differential scanning calorimetry (DSC), and more specifically described in JIS K 7121-1987 "Method for measuring transition temperature of plastics". It is obtained by the "external glass transition start temperature" of.

The weight average molecular weight (Mw) of the amorphous polyester resin is preferably 5000 or more and 1,000,000 or less, and more preferably 7,000 or more and 500,000 or less.
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 carried out by using Tosoh's GPC / HLC-8120GPC as a measuring device, using Tosoh's column / TSKgel SuperHM-M (15 cm), and using a THF solvent. The weight average molecular weight and the number average molecular weight are calculated from this measurement result using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

Amorphous polyester resin is obtained by a well-known manufacturing method. Specifically, for example, the polymerization temperature is set to 180 ° C. or higher and 230 ° C. or lower, the pressure inside the reaction system is reduced as necessary, and the reaction is carried out while removing water and alcohol generated during condensation.
When the raw material monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a dissolution aid to dissolve the monomer. In this case, the polycondensation reaction is carried out while distilling off the dissolution aid. If a monomer with poor compatibility is present in the copolymerization reaction, the monomer with poor compatibility, the monomer, and the acid or alcohol to be polycondensed are condensed in advance, and then weighted 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-mentioned unmodified polyester resins. The modified polyester resin is a polyester resin having a bonding group other than an ester bond, 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 polyester 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 one of the amorphous resins, 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 reacting a polyester resin having an isocyanate group (polyester prepolymer) with an amine compound (at least one reaction of a cross-linking reaction and an extension reaction). 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 polyester having active hydrogen with a polyhydric isocyanate compound. .. Examples of the group having active hydrogen contained 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 the polyhydric alcohol include compounds similar to the polyvalent carboxylic acid and the polyhydric alcohol described in the polyester resin.

Polyisocyanate compounds include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethyl caproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatics. Diisocyanate (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); aromatic aliphatic diisocyanate (α, α, α', α'-tetramethylxylylene diisocyanate, etc.); isocyanurates; Examples include those blocked with a blocking agent.
The polyisocyanate compound may be used alone or in combination of two or more.

The ratio of the polyisocyanate compound is preferably 1/1 or more and 5/1 or less, as the equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester prepolymer having a hydroxyl group. It is preferably 1.2 / 1 or more and 4/1 or less, and more preferably 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 polyhydric isocyanate compound is preferably 0.5% by mass or more and 40% by mass or less, more preferably, with respect to the entire polyester prepolymer having an isocyanate group. It is 1% by mass or more and 30% by mass or less, more preferably 2% by mass or more and 20% by mass or less.

The number of isocyanate groups contained in one 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 on average, and still more preferably 1.8 or more on average 2. .5 or less.

Examples of the amine compound that reacts with the polyester prepolymer having an isocyanate group include diamines, trivalent or higher polyamines, amino alcohols, amino mercaptans, amino acids, and compounds in which these amino groups are blocked.

Examples of the diamine 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 triamine or higher polyamine include diethylenetriamine and triethylenetetramine.
Examples of the amino alcohol include ethanolamine and hydroxyethylaniline.
Examples of the amino mercaptan include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of amino acids include aminopropionic acid and aminocaproic acid.
Blocking these amino groups includes amine compounds such as diamines, trivalent or higher polyamines, aminoalcohols, aminomercaptans, and amino acids, and ketimine compounds obtained from ketone compounds (acetones, methyl ethyl ketones, methyl isobutyl ketones, etc.). Examples include oxazoline compounds.
Of these amine compounds, ketimine compounds are preferred.
The amine compound may be used alone or in combination of two or more.

The urea-modified polyester resin is a polyester resin (polyester prepolymer) having an isocyanate group by a terminator that terminates at least one of the crosslinking reaction and the elongation reaction (hereinafter, also referred to as “crosslinking / elongation reaction terminator”). The resin may have an adjusted molecular weight after the reaction by adjusting the reaction with the amine compound (at least one of the cross-linking reaction and the extension reaction).
Examples of the cross-linking / extension reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.) and those that block them (ketimine compounds).

The ratio of the amine compound is preferably 1/2 or more as the 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. It is 1/1 or less, more preferably 1 / 1.5 or more and 1.5 / 1 or less, and further preferably 1 / 1.2 or more and 1.2 / 1 or less.

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 50,000 or less, and more preferably 2500 or more and 30,000 or less. The weight average molecular weight is preferably 10,000 or more and 500,000 or less, and more preferably 30,000 or more and 100,000 or less.

-Crystalline polyester resin Examples of the crystalline polyester resin include a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol. As the crystalline polyester resin, a commercially available product may be used, or a synthetic resin may be used.
Here, since the crystalline polyester resin easily forms a crystal structure, a polycondensate using a polymerizable monomer having a linear aliphatic is preferable to a polymerizable monomer having an aromatic.

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-nonandicarboxylic acid, and 1,10-decandicarboxylic acid. Acids, 1,12-dodecanedicarboxylic acids, 1,14-tetradecandicarboxylic acids, 1,18-octadecanedicarboxylic acids, etc., aromatic dicarboxylic acids (eg, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid) Examples thereof include dibasic acids such as acids), anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
As the polyvalent carboxylic acid, a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. 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.). Anhydrides or lower (for example, 1 to 5 carbon atoms) alkyl esters thereof can be mentioned.
As the polyvalent carboxylic acid, a dicarboxylic acid having a sulfonic acid group and a dicarboxylic acid having an ethylenic double bond may be used in combination with these dicarboxylic acids.
The polyvalent carboxylic acid may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include an aliphatic diol (for example, a linear aliphatic diol having 7 or more and 20 or less carbon atoms in the main chain portion). Examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and 1,8-. Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18- Examples thereof include octadecanediol and 1,14-eicosanedecanediol. Among these, as the aliphatic diol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable.
As the polyhydric alcohol, a trihydric or higher alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like.
The polyhydric alcohol may be used alone or in combination of two or more.

Here, the polyhydric alcohol preferably has an aliphatic diol content of 80 mol% or more, 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 DSC curve obtained by differential scanning calorimetry (DSC) by the "melting peak temperature" described in the method for determining the melting temperature in JIS K7121-1987 "Method for measuring transition temperature of plastics".

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 a well-known manufacturing method, like the amorphous polyester resin, for example.

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

-Colorant-
Colorants include, for example, carbon black, chrome yellow, Hansa yellow, benzine yellow, slene yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliant carmine 3B, brilliant. Carmin 6B, Dupont Oil Red, Pyrazolon Red, Resole Red, Rhodamin B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultra Marine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malachite green oxalate, or aclysine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black Examples thereof include various dyes such as system, polymethine type, triphenylmethane type, diphenylmethane type and thiazole type.
One type of colorant may be used alone, or two or more types may be used in combination.

As the colorant, a surface-treated colorant may be used if necessary, or may be used in combination with a dispersant. Further, a plurality of kinds 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 the release agent include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; 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.
The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) by the "melting peak temperature" described in the method for determining the melting temperature in JIS K 7121-1987 "Method for measuring transition temperature of plastics". ..

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

-Other additives-
Examples of other additives include well-known additives such as magnetic materials, charge control agents, and inorganic powders. These additives are contained in the toner particles as an internal additive.

-Characteristics of toner particles, etc.-
The toner particles may be toner particles having a single layer structure, or are toner particles having a so-called core-shell structure composed of a core portion (core particles) and a coating layer (shell layer) that covers the core portion. You may.
Here, the toner particles having a core-shell structure include, for example, a core portion composed of a binder resin and, if necessary, other additives such as a colorant and a mold release agent, and a binder resin. It is preferably composed of a composed coating layer.

The volume average particle size (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.

The various average particle sizes and various particle size distribution indexes of the toner particles were measured using Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolytic solution was measured using ISOTON-II (manufactured by Beckman Coulter). Toner.
At the time of measurement, 0.5 mg or more and 50 mg or less of the measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant. This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolytic solution 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 or more and 60 μm or less is obtained by using an aperture with an aperture diameter of 100 μm by Coulter Multisizer II. Measure. The number of particles to be sampled is 50,000.
Cumulative distribution of volume and number is drawn from the small diameter side for each particle size range (channel) divided based on the measured particle size distribution, and the cumulative 16% particle size is volume particle size D16v and number particle size. The particle size with D16p and cumulative 50% is defined as volume average particle size D50v and cumulative number average particle size D50p, and the particle size with cumulative 84% is defined as volume particle size D84v and 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 0.94 or more and 1.00 or less, and more preferably 0.95 or more and 0.98 or less.

The average circularity of the toner particles is obtained by (circumferential peripheral length) / (circumferential length) [(circular length of a circle having the same projected area as the particle image) / (peripheral length of the particle projected image)]. Specifically, it is a value measured by the following method.
First, a flow-type particle image analyzer (Cysmex) that captures a particle image as a still image by sucking and collecting toner particles to be measured, forming a flat flow, and instantly causing strobe light emission to analyze the particle image. Obtained by FPIA-2100) manufactured by the company. Then, the number of samplings when calculating the average circularity is set to 3500.
When the toner has an external additive, the toner (developer) to be measured is dispersed in water containing a surfactant, and then ultrasonic treatment is performed to obtain toner particles from which the external additive has been removed. ..

(External agent)
In the toner according to the present embodiment, other external additives may be added in addition to the above-mentioned composite particles.
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 should be hydrophobized. The hydrophobizing treatment is performed, for example, by immersing the inorganic particles in a hydrophobizing agent. The hydrophobizing agent is not particularly limited, and examples thereof include a silane-based coupling agent, a silicone oil, a titanate-based coupling agent, and an aluminum-based coupling agent. These may be used alone or in combination of two or more.
The amount of the hydrophobizing agent is usually, for example, 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic particles.

Examples of the external additive include resin particles (resin particles such as polystyrene, polymethylmethacrylate (PMMA), and melamine resin), cleaning activators (for example, metal salts of higher fatty acids typified by zinc stearate, fluoropolymers). Particles) and the like.

(Toner manufacturing method)
Next, a method for producing toner according to this embodiment will be described.
The toner according to the present embodiment can be obtained by externally adding an external additive containing the above-mentioned composite particles to the toner particles after producing the toner particles.

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

For example, in the dissolution / suspension method, a liquid in which raw materials (binding resin, coloring agent, etc.) constituting toner particles are dissolved or dispersed in an organic solvent in which the binding resin can be dissolved is contained as a particle dispersant. This is a method obtained by granulating toner particles by dispersing the particles in an aqueous solvent and then removing the organic solvent.
Further, the aggregation and coalescence method is a method of obtaining toner particles through an aggregation step of forming aggregates of raw materials (resin particles, colorants, etc.) 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 may be obtained by the following dissolution / suspension method. In the following description of the dissolution / suspension method, a method of obtaining toner particles containing an unmodified polyester resin and a urea-modified polyester resin as the binder resin will be described, but only the urea-modified polyester resin is used as the binder resin. It may be included.

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

The oil phase liquid is prepared by 1) a method of preparing by dissolving or dispersing the toner material in an organic solvent all at once, and 2) kneading the toner material in advance and then dissolving or dispersing this kneaded compound in an organic solvent. 3) A method of preparing by dissolving an unmodified polyester resin, a polyester prepolymer having an isocyanate group, and an amine compound in an organic solvent, and then dispersing a colorant and a mold release agent in the organic solvent. 4) A method of preparing by dissolving an unmodified polyester resin, a polyester prepolymer having an isocyanate group, and an amine compound in an organic solvent after dispersing a colorant and a mold release agent in an organic solvent. Toner particle materials (unmodified polyester resin, colorant, and mold release agent) other than the polyester prepolymer having a group and the amine compound are dissolved or dispersed in an organic solvent, and then the polyester pre having an isocyanate group is dissolved in this organic solvent. Method of dissolving and preparing polymer and amine compound, 6) Dissolve or disperse toner particle material (unmodified polyester resin, colorant, and mold release agent) other than polyester prepolymer or amine compound having isocyanate group in organic solvent. Then, a method for preparing by dissolving a polyester prepolymer having an isocyanate group or an amine compound in this organic solvent can be mentioned. The method for preparing the oil phase liquid is not limited to these.

Examples of the organic solvent of 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; and dichloromethane, chloroform, trichloroethylene and the like. Examples thereof include halogenated hydrocarbon solvents. It is preferable that these organic solvents dissolve the binder resin, dissolve in water at a rate of 0% by mass or more and 30% by mass or less, and have a boiling point of 100 ° C. or less. Among these organic solvents, ethyl acetate is preferable.

-Suspension preparation process-
Next, the obtained oil phase liquid is dispersed in the aqueous phase liquid to prepare a suspension (suspension preparation step).
Then, along with the preparation of the suspension, the reaction between the polyester prepolymer having an isocyanate group and the amine compound is carried out. Then, a urea-modified polyester resin is produced by this reaction. This reaction involves at least one of a molecular chain cross-linking reaction and an extension reaction. The reaction between the polyester prepolymer having an isocyanate group and the amine compound may be carried out together with the solvent removing step described later.
Here, the reaction conditions are selected based on the reactivity of the isocyanate group structure of the polyester prepolymer with the amine compound. As an example, the reaction time is preferably 10 minutes or more and 40 hours or less, and preferably 2 hours or more and 24 hours or less. The reaction temperature is preferably 0 ° C. or higher and 150 ° C., and preferably 40 ° C. or higher and 98 ° C. or lower. A known catalyst (dibutyltin laurate, dioctyltin laurate, etc.) may be used to produce the urea-modified polyester resin, if necessary. 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. Further, as the aqueous phase liquid, an aqueous phase liquid in which a particle dispersant is dispersed in an aqueous solvent and a polymer dispersant is dissolved in an aqueous solvent can also be mentioned. A well-known additive such as a surfactant may be added to the aqueous phase liquid.

Examples of the aqueous solvent include water (usually ion-exchanged water, distilled water, pure water). The aqueous solvent is a solvent containing water and an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellsolves (methylcellsolve, etc.), lower ketones (acetone, methylethylketone, etc.). There may be.

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

Examples of the inorganic particle dispersant include a hydrophilic inorganic particle dispersant. Specific examples of the inorganic particle dispersant include particles such as silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, clay, diatomaceous earth, and bentonite, and calcium carbonate particles are preferable. As the inorganic particle dispersant, one type may be used alone, or two or more types may be used in combination.

The surface of the particle dispersant may be surface-treated with a polymer having a carboxyl group.
As the polymer having a carboxyl group, the carboxyl group of α, β-monoethylene unsaturated carboxylic acid or α, β-monoethylene unsaturated carboxylic acid is composed of alkali metal, alkaline earth metal, ammonia, amine or the like. Examples include 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-monoethylene unsaturated carboxylic acid esters. Be done. As the polymer having a carboxyl group, the carboxyl group of the copolymer of α, β-monoethylene unsaturated carboxylic acid and α, β-monoethylene unsaturated carboxylic acid ester is an alkali metal or an alkaline earth metal. , Alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts, etc., which are neutralized with ammonia, amines, etc. As the polymer having a carboxyl group, one type may be used alone, or two or more types may be used in combination.

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

Examples of the polymer dispersant include hydrophilic polymer dispersants. Specific examples of the polymer dispersant include water-soluble polymer dispersants (for example, carboxymethyl cellulose, carboxyethyl cellulose, etc.) having a carboxyl group and no parent oil group (hydroxypropoxy group, methoxy group, etc.). Sexual cellulose ether).

-Solvent removal process-
Next, the organic solvent is removed from the obtained suspension to obtain a toner particle dispersion (solvent removal step). This solvent removing step is a step of removing the organic solvent contained in the droplets of the aqueous phase liquid dispersed in the suspension to generate toner particles. The removal of the organic solvent from the suspension may be carried out immediately after the suspension preparation step, or may be carried out one minute or more after the completion of the suspension preparation step.
In the solvent removing step, it is preferable to remove the organic solvent from the suspension by cooling or heating the obtained suspension to, for example, 0 ° C. or higher and 100 ° C. or lower.

Specific methods for removing the organic solvent include the following methods.
(1) A method of forcibly updating the gas phase on the suspension surface by blowing an air flow 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 suspension surface may be forcibly updated by filling with gas, or gas may be blown into the suspension.

Toner particles are obtained through the above steps.
Here, after the solvent removal step is completed, the toner particles formed in the toner particle dispersion liquid are obtained as dried toner particles through a known washing step, solid-liquid separation step, and drying step.
In the cleaning step, it is preferable to sufficiently perform replacement cleaning with ion-exchanged water from the viewpoint of chargeability.
The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration and the like may be performed from the viewpoint of productivity. The drying step is also not particularly limited, but from the viewpoint of productivity, freeze-drying, air-flow drying, fluid drying, vibration-type fluid drying and the like may be performed.

Then, the toner according to the present embodiment is produced, for example, by adding an external additive containing the above-mentioned composite particles to the obtained dry toner particles and mixing them.
The mixing may be carried out by, for example, a V blender, a Henschel mixer, a Ladyge mixer or the like.
Further, if necessary, coarse particles of toner may be removed by using a vibration sieving machine, a wind sieving machine or the like.

[Kneading and crushing method]
In the kneading and crushing method, after mixing each material such as a colorant, the above materials are melt-kneaded using a kneader, an extruder, etc., the obtained melt-kneaded product is roughly pulverized, and then pulverized by a jet mill or the like. , A method of obtaining toner particles having a target particle size by a wind power classifier.
More specifically, the kneading and pulverizing method is divided into a kneading step of kneading a toner forming material containing a colorant and a binder resin and a pulverizing step of pulverizing the kneaded product. If necessary, it may have other steps such as a cooling step of cooling the kneaded product formed by the kneading step.

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

Examples of the kneading machine used in the kneading step include a single-screw extruder and a twin-screw extruder. Hereinafter, as an example of the 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 a screw state with respect to 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 adds an aqueous medium to the barrel 12 provided with a screw (not shown), the injection port 14 for injecting the toner forming material which is the raw material of the toner into the barrel 12, and the toner forming material in the barrel 12. It is composed of a liquid addition port 16 for discharging the kneaded material formed by kneading the toner forming material in the barrel 12 and a discharge port 18 for discharging the kneaded material.

The barrel 12 has 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 closest to the injection port 14, and the toner forming material is melt-kneaded by the first kneading step. Knees for forming a kneaded product by melting and kneading the feed screw portion SB and the toner forming material for transporting the toner forming material melt-kneaded in the kneading portion NA and the kneading portion NA to the kneading portion NB by the second kneading step. It is divided into a ding portion NB and a feed screw portion SC that transports the formed kneaded material to the discharge port 18.

Further, inside the barrel 12, different temperature control means (not shown) are provided for each block. That is, the temperature may be controlled differently from the block 12A to the block 12J. FIG. 3 shows a state in which the temperatures of the blocks 12A and 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. There is. Therefore, the toner forming material of the kneading portion NA is heated to t1 ° C., and the toner forming material of the kneading portion NB is heated to t2 ° C.

When the toner forming material containing the binder resin, the colorant, and if necessary, the mold release agent and the like is supplied from the injection port 14 to the barrel 12, the toner forming material is sent from the feed screw portion SA to the kneading portion NA. At this time, since the temperature of the block 12C is set to t1 ° C., the toner forming material is sent to the kneading section NA in a state of being heated and changed to a molten state. Since the temperatures of the blocks 12D and 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 mold release agent are in a molten state at the kneading portion NA and are sheared by the screw.

Next, the toner forming material that has undergone kneading in the kneading portion NA is sent to the kneading portion NB by the feed screw portion SB.
Then, in the feed screw portion SB, the water-based medium is added to the toner-forming material by injecting the water-based medium from the liquid addition port 16 into the barrel 12. Further, FIG. 3 shows a form in which the water-based medium is injected into the feed screw portion SB, but the present invention is not limited to this, and the water-based medium may be injected into the kneading portion NB, and the feed screw portion SB and the kneading portion NB may be injected. An aqueous medium may be injected in both. That is, the position and the injection location for injecting the aqueous medium are selected as necessary.

As described above, when the water-based medium is injected into the barrel 12 from the liquid addition port 16, the toner-forming material in the barrel 12 and the water-based medium are mixed, and the toner-forming material is cooled by the latent heat of vaporization of the water-based medium. The temperature of the toner forming material is maintained.
Finally, the kneaded product formed by melt-kneading by the kneading section NB is transported to the discharge port 18 by the feed screw section 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, and in the cooling step, the temperature of the kneaded product at the end of the kneading step is cooled to 40 ° C. or lower at an average temperature lowering rate of 4 ° C./sec or more. It is preferable to do so. When the cooling rate of the kneaded product is slow, a mixture of a mixture finely dispersed in the binder resin (colorant and, if necessary, an internal additive such as a release agent added to the toner particles) in the kneading process. ) May recrystallize and the dispersion diameter may increase. On the other hand, quenching at the above average temperature lowering rate is preferable because the dispersed state immediately after the completion of the kneading step is maintained as it is. The average temperature lowering rate is the average value of the rate at which the temperature of the kneaded product is lowered from the temperature of the kneaded product (for example, t2 ° C. when the screw extruder 11 in FIG. 3 is used) to 40 ° C. at the end of the kneading step.
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 type 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 product, the slab thickness at the time of rolling the kneaded product, and the like. The slab thickness is preferably as thin as 1 mm or more and 3 mm or less.

-Crushing process-
The kneaded product cooled by the cooling step is crushed by the crushing step to form particles. In the crushing step, for example, a mechanical crusher, a jet crusher, or the like is used.

-Classification process-
The particles obtained in 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, inertial classifiers, etc. are used, and fine powder (particles smaller than the target particle size) and coarse powder (particle size in the target range) are used. Larger particles) are removed.

-External process-
The obtained toner particles are externally supplemented with the above-mentioned composite particles. Further, an external agent such as inorganic particles typified by silica, titania, or aluminum oxide may be added and adhered for the purpose of adjusting charge, imparting fluidity, imparting charge exchange property, and the like. These are performed by, for example, a V-type blender, a Henschel mixer, a Ladyge mixer, or the like, and may be attached in stages.

-Sieve process-
After the external addition step, a sieving step may be provided if necessary. Specific examples of the sieving method include a gyro shifter, a vibration sieving machine, and a wind sieving machine. By sieving, coarse powder of the external additive is removed, and streaks on the photoconductor and spilled stains in the apparatus are suppressed.

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

Specifically, for example, when the toner particles are produced by the aggregation and coalescence method,
A step of preparing a resin particle dispersion liquid in which resin particles to be a binder resin are dispersed (resin particle dispersion liquid preparation step) and a step of preparing the resin particle dispersion liquid (after mixing other particle dispersion liquids as necessary). (In the dispersion), resin particles (other particles if necessary) are agglomerated to form agglomerated particles (aggregated particle forming step), and the agglomerated particle dispersion in which the agglomerated particles are dispersed is heated. , Agglomerated particles are fused and coalesced to form toner particles (fusion and coalescence step), and toner particles are manufactured.

The details of each step will be described below.
In the following description, a method for obtaining toner particles containing a colorant and a release agent will be described, but the colorant and the release agent are used as needed. Of course, other additives other than colorants and mold release agents may be used.

-Resin particle dispersion liquid preparation process-
First, together with the resin particle dispersion liquid in which the resin particles to be the binder resin are dispersed, for example, a colorant particle dispersion liquid in which the colorant particles are dispersed and a release agent particle dispersion liquid in which the release agent particles are dispersed are prepared. To do.

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

Examples of the dispersion medium used in the resin particle dispersion liquid include an aqueous medium.
Examples of the aqueous medium include distilled water, water such as ion-exchanged water, alcohols, and the like. These may be used alone or in combination of two or more.

Examples of the surfactant include anionic surfactants such as sulfate ester salt type, sulfonate type, phosphoric acid ester type and soap type; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol. Examples thereof include nonionic surfactants such as systems, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
The surfactant may be used alone or in combination of two or more.

Examples of the method for dispersing the resin particles in the dispersion medium in the resin particle dispersion liquid include general dispersion methods such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, and a dyno mill. Further, depending on the type of resin particles, the resin particles may be dispersed in the resin particle dispersion liquid by, for example, a phase inversion emulsification method.
In the phase inversion emulsification method, the 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 resin, and then the aqueous medium is used. A method in which the (W phase) is charged to convert the resin from W / O to O / W (so-called phase inversion) to discontinue the phase, and the resin is dispersed in an aqueous medium in the form of particles. Is.

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

The content of the resin particles contained in the resin particle dispersion is, for example, preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

In the same manner as the resin particle dispersion, for example, a colorant particle dispersion and a release agent particle dispersion are also prepared. That is, regarding the volume average particle size, dispersion medium, dispersion method, and particle content of the particles in the resin particle dispersion, the colorant particles dispersed in the colorant particle dispersion and the release agent particle dispersion are used. The same applies to the disperse of the release agent particles.

-Agglomerated 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, the resin particles, the colorant particles, and the release agent particles are heteroaggregated to form the resin particles, the colorant particles, and the release agent particles having a diameter close to the diameter of the target toner particles. Form agglomerated particles containing.

Specifically, for example, a flocculant is added to the mixed dispersion, 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 particles are heated to a temperature of the glass transition temperature of the resin particles (specifically, for example, the glass transition temperature of the resin particles is -30 ° C or higher and the glass transition temperature is -10 ° C or lower), and the particles dispersed in the mixed dispersion are aggregated. , Form agglomerated particles.
In the agglomerated particle forming step, for example, the mixed dispersion is stirred with a rotary shear type homogenizer, the above-mentioned flocculant is added at room temperature (for example, 25 ° C.), and the pH of the mixed dispersion is acidic (for example, pH is 2 or more and 5 or less). ), And if necessary, a dispersion stabilizer may be added, and then the above heating may be performed.

Examples of the flocculant include a surfactant used as a dispersant added to the mixed dispersion, a surfactant having the opposite polarity, an inorganic metal salt, and a divalent or higher 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.
Additives that form a complex or similar bond with the metal ions of the flocculant may be used as needed. As this additive, a chelating agent is preferably used.

Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride and aluminum sulfate, and inorganics such as polyaluminum chloride, polyaluminum hydroxide and calcium polysulfide. Examples include metal salt polymers.
As the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids such as tartrate acid, citric acid and gluconic acid, iminodic acid (IDA), nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA).
The amount of the chelating agent added is, for example, preferably 0.01 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.1 parts by mass or more and less than 3.0 parts by mass with respect to 100 parts by mass of the resin particles.

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

Toner particles are obtained through the above steps.
After obtaining the agglomerated particle dispersion liquid in which the agglomerated particles are dispersed, the agglomerated 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 agglomerated particles. The step of aggregating so as to adhere to form the second agglomerated particles and the second agglomerated particle dispersion liquid in which the second agglomerated particles are dispersed are heated to fuse and unite the second agglomerated particles. , Toner particles may be produced through the steps of forming toner particles having a core / shell structure.

Here, after the fusion / coalescence step is completed, the toner particles formed in the solution are subjected to a known washing step, solid-liquid separation step, and drying step to obtain toner particles in a dried state.
In the cleaning step, it is preferable to sufficiently perform replacement cleaning with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration and the like may be performed from the viewpoint of productivity. The drying step is also not particularly limited, but from the viewpoint of productivity, freeze-drying, air-flow drying, fluid drying, vibration-type fluid drying and the like may be performed.

Then, the toner according to the present embodiment is produced, for example, by adding an external additive containing the above-mentioned composite particles to the obtained dry toner particles and mixing them. The mixing may be carried out by, for example, a V blender, a Henschel mixer, a Ladyge mixer or the like. Further, if necessary, coarse particles of toner may be removed by using a vibration sieving machine, a wind sieving machine or the like.

<Static charge image developer>
The electrostatic charge image developer according to the present embodiment contains at least the toner according to the present embodiment.
The electrostatic charge image developer according to the present embodiment may be a one-component developer containing only the toner according to the present embodiment, or a two-component developer mixed with the toner and a carrier.

The carrier is not particularly limited, and examples thereof include known carriers. Examples of the carrier include a coating carrier in which the surface of a core material made of magnetic powder is coated with a coating resin; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and blended in a matrix resin; and a porous magnetic powder impregnated with resin. Resin-impregnated carrier; etc.
The magnetic powder dispersion type carrier and the resin impregnation type carrier may be carriers in which the constituent particles of the carrier are used as a core material and 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 matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, and styrene-acrylic acid ester. Examples thereof include a copolymer, a straight silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polypropylene, a phenol resin, an epoxy resin and the like.
The coating resin and the matrix resin may contain other additives such as conductive particles.
Examples of the conductive particles include metals such as gold, silver and copper, and particles such as 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 resin and, if necessary, a coating layer forming solution in which various additives are dissolved in an appropriate solvent can 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 a coating layer forming solution, a spray method in which the coating layer forming solution is sprayed on the core material surface, and a state in which the core material is suspended by flowing air. Examples thereof include a fluidized bed method in which a solution for forming a coating layer is sprayed, a kneader coater method in which a core material of a carrier and a solution for forming a coating layer are mixed in a kneader coater, and a 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 device / 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 holder, a charging means for charging the surface of the image holder, a static charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and an electrostatic charge. A developing means that accommodates an image developer and develops an electrostatic charge image formed on the surface of the image holder as a toner image by the static charge image developer, and a recording medium that records the toner image formed on the surface of the image holder. It is provided with a transfer means for transferring to the surface of the recording medium and a fixing means for fixing the toner image transferred to the surface of the recording medium. Then, as the electrostatic charge image developer, the electrostatic charge image developer according to the present embodiment is applied.

In the image forming apparatus according to the present embodiment, a charging step of charging the surface of the image holder, a static charge image forming step of forming an electrostatic charge image on the surface of the charged image holder, and an electrostatic charge according to the present embodiment. A development step of developing an electrostatic charge image formed on the surface of an image holder as a toner image with an image developer, and a transfer step of transferring a toner image formed on the surface of the image holder to the surface of a recording medium. An image forming method (image forming method according to the present embodiment) having a fixing step of fixing a toner image transferred to the surface of a recording medium is carried out.

The image forming apparatus according to the present embodiment is a direct transfer type apparatus that directly transfers the toner image formed on the surface of the image holder to the recording medium; the toner image formed on the surface of the image holder is transferred to the intermediate transfer body. An intermediate transfer type device that first transfers the toner image to the surface and then secondarily transfers the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium; after transferring the toner image, cleans the surface of the image holder before charging. A device provided with a cleaning means; a well-known image forming device such as a device provided with a static elimination means for irradiating the surface of an image holder with static elimination light after transfer of a toner image and before charging is applied.
In the case of an intermediate transfer type apparatus, the transfer means is, for example, an intermediate transfer body in which a toner image is transferred to the surface and a primary transfer in which a toner image formed on the surface of an image holder is primarily transferred to the surface of the intermediate transfer body. A configuration comprising means and secondary transfer means for secondary transfer of the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium is applied.

In the image forming apparatus according to the present embodiment, for example, the portion including the developing means may have a cartridge structure (process cartridge) that is attached to and detached from the image forming apparatus. As the process cartridge, for example, a process cartridge including a developing means 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 shown, but the present invention is not limited thereto. The main parts shown in the figure will be described, and the other parts will be omitted.

FIG. 4 is a schematic configuration diagram showing an image forming apparatus according to the present embodiment.
The image forming apparatus shown in FIG. 4 is an electrophotographic first to output an image of each color of yellow (Y), magenta (M), cyan (C), and black (K) based on color-separated image data. A fourth image forming unit 10Y, 10M, 10C, 10K (image forming means) is provided. These image forming units (hereinafter, may be simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged side by side at a predetermined distance from each other in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are attached to and detached from the image forming apparatus.

An intermediate transfer belt 20 as an intermediate transfer body extends through each unit above the drawings of each unit 10Y, 10M, 10C, and 10K. The intermediate transfer belt 20 is provided by being wound around a drive roll 22 arranged apart from each other from the left to the right in the drawing and a support roll 24 in contact with the inner surface of the intermediate transfer belt 20, and the first unit 10Y to the fourth unit 10Y to the fourth. It is designed to run in the direction toward the unit 10K. A force is applied to the support roll 24 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. Further, an intermediate transfer body cleaning device 30 is provided on the side surface of the image holder of the intermediate transfer belt 20 so as to face the drive roll 22.
Further, the developing devices (development means) 4Y, 4M, 4C, and 4K of each unit 10Y, 10M, 10C, and 10K each have yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K. Toner containing the four colors of toner is supplied.

Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration, here, the first unit forming a yellow image arranged on the upstream side in the traveling direction of the intermediate transfer belt. 10Y will be described as a representative. In addition, the second to fourth units are provided with reference numerals having magenta (M), cyan (C), and black (K) instead of yellow (Y) in the portion equivalent to the first unit 10Y. The description of the units 10M, 10C, and 10K of the above is omitted.

The first unit 10Y has a photoconductor 1Y that acts as an image holder. Around the photoconductor 1Y, a charging roll (an example of charging means) 2Y that charges the surface of the photoconductor 1Y to a predetermined potential, and a laser beam 3Y based on a color-separated image signal expose the charged surface. An exposure device (an example of a static charge image forming means) 3 for forming an electrostatic charge image, and a developing device (an example of a developing means) 4Y for developing a static charge image by supplying charged toner to the static charge image. A primary transfer roll 5Y (an example of a primary transfer means) that transfers a toner image onto an intermediate transfer belt 20, and a photoconductor cleaning device (an example of a cleaning means) 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 arranged inside the intermediate transfer belt 20 and is provided at a position facing the photoconductor 1Y. Further, a bias power supply (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 supply changes the transfer bias applied to each primary transfer roll by control by a control unit (not shown).

Hereinafter, the operation of forming a yellow image in the first unit 10Y will be described.
First, prior to the operation, the surface of the photoconductor 1Y is charged to a potential of −600V to −800V by the charging roll 2Y.
The photoconductor 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 resistivity (resistance of a general resin), but has a property that when the laser beam 3Y is irradiated, the specific resistance of the portion irradiated with the laser beam changes. Therefore, the laser beam 3Y is output to the surface of the charged photoconductor 1Y via the exposure apparatus 3 according to the image data for yellow sent from the control unit (not shown). The laser beam 3Y irradiates the photosensitive layer on the surface of the photoconductor 1Y, whereby an electrostatic charge image of a yellow image pattern is formed on the surface of the photoconductor 1Y.

The static charge image is an image formed on the surface of the photoconductor 1Y by charging. The laser beam 3Y reduces the specific resistance of the irradiated portion of the photosensitizer layer, and the charged charge on the surface of the photoconductor 1Y flows. On the other hand, it is a so-called negative latent image formed by the residual charge of the portion not irradiated with the laser beam 3Y.
The electrostatic charge image formed on the photoconductor 1Y is rotated to a predetermined development position as the photoconductor 1Y travels. Then, at this developing position, the electrostatic charge image on the photoconductor 1Y is converted into a visible image (developed image) as a toner image by the developing device 4Y.

In the developing apparatus 4Y, for example, a static charge image developing agent containing at least yellow toner and a carrier is housed. The yellow toner is triboelectrically charged by being agitated inside the developing apparatus 4Y, and has a charge having the same polarity (negative electrode property) as the charged charge on the photoconductor 1Y, and is a developer roll (developing agent holder). Example) It is held on. Then, as the surface of the photoconductor 1Y passes through the developing device 4Y, the yellow toner is electrostatically adhered to the statically eliminated latent image portion on the surface of the photoconductor 1Y, and the latent image is developed by the yellow toner. .. The photoconductor 1Y on which the yellow toner image is formed is continuously traveled at a predetermined speed, and the toner image developed on the photoconductor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoconductor 1Y is transferred to the primary transfer, a primary transfer bias is applied to the primary transfer roll 5Y, and an electrostatic force from the photoconductor 1Y toward the primary transfer roll 5Y is applied to the toner image to act on the photoconductor. 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 that 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 photoconductor 1Y is removed by the photoconductor cleaning device 6Y and recovered.

Further, the primary transfer bias applied to the primary transfer rolls 5M, 5C, and 5K after the second unit 10M is also controlled according to the first unit.
In this way, the intermediate transfer belt 20 to which the yellow toner image is transferred in the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of each color are superimposed and multiple transferred. Toner.

The intermediate transfer belt 20 on which four color toner images are multiplex-transferred through the first to fourth units is arranged on the image holding surface side of the intermediate transfer belt 20, the support roll 24 in contact with the inner surface of the intermediate transfer belt, and the intermediate transfer belt 20. It leads to a secondary transfer unit composed of the secondary transfer roll (an example of the secondary transfer means) 26. On the other hand, the recording paper (an example of the recording medium) P is fed to the gap where the secondary transfer roll 26 and the intermediate transfer belt 20 are in contact with each other via the supply mechanism at a predetermined timing, and the secondary transfer bias is supported by the support roll. It is applied to 24. The transfer bias applied at this time has a (-) polarity that is the same 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, and the transfer bias is applied on the intermediate transfer belt 20. The toner image of is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by the resistance detecting means (not shown) for detecting the resistance of the secondary transfer unit, and is voltage controlled.

After that, the recording paper P is sent to the pressure contact portion (nip portion) of the pair of fixing rolls in the fixing device (an example of the fixing means) 28, and the toner image is fixed on the recording paper P to form the fixing image.

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

The recording paper P for which the color image has been fixed is carried out toward the ejection 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 contains the electrostatic charge image developer according to the present embodiment, and is a developing means for developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developer. It is a process cartridge that is attached to and detached from the image forming apparatus.

The process cartridge according to the present embodiment is not limited to the above configuration, and includes a developing device and other means such as an image holder, a charging means, an electrostatic charge image forming means, and a transfer means, if necessary. It may be configured to include at least one selected from.

Hereinafter, an example of the process cartridge according to the present embodiment will be shown, but the present invention is not limited to this. The main parts shown in the figure will be described, and the other parts will be omitted.

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 photoconductor 107 (an example of an image holder) and the photoconductor 107 by, for example, a housing 117 provided with a mounting rail 116 and an opening 118 for exposure. The charged roll 108 (an example of the charging means), the developing device 111 (an example of the developing means), and the photoconductor cleaning device 113 (an example of the cleaning means) are integrally combined and held and configured to form a cartridge. There is.
In FIG. 5, 109 is an exposure device (an example of an electrostatic charge image forming means), 112 is a transfer device (an example of a transfer means), 115 is a fixing device (an example of a fixing means), and 300 is a recording paper (an example of a recording medium). An example) is shown.

Next, the toner cartridge according to this embodiment will be described.
The toner cartridge according to the present embodiment is a toner cartridge that houses the toner according to the present embodiment and is attached to and detached from the image forming apparatus. The toner cartridge accommodates a replenishing toner for supplying 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 structure in which the toner cartridges 8Y, 8M, 8C, and 8K are attached and detached, and the developing apparatus 4Y, 4M, 4C, and 4K are each developing apparatus (color). ) Is connected to a toner cartridge (not shown). Further, when the amount of toner contained in the toner cartridge is low, the toner cartridge is replaced.

Hereinafter, the present embodiment will be described in more detail with reference to Examples and Comparative Examples, but the present embodiment is not limited to these Examples. In addition, "part" and "%" are based on mass unless otherwise specified.

(Preparation of complex particles)
-Preparation of complex particle 1-
・ Lubricant particles (positively charged)
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
・ Monopole particles (negative charge)
Silica particles, trade name: RY50, manufactured by Nippon Aerosil Co., Ltd., average particle size = 40 nm
100 parts of the above lubricant particles (zinc stearate) and 6.0 parts of reverse electrode particles (silica particles) are mixed, and a powder processing device (Nobilta NOB130, manufactured by Hosokawa Micron) has a clearance of 3 mm and a peripheral speed of 1500 rpm. After blending for 10 minutes while running cooling water through the jacket, coarse particles were removed using a sieve having a 45 μm opening to obtain composite particles having a low coverage.
On the other hand, composite particles having a high coverage were obtained in the same manner as the composite particles having a low coverage except that the amount of reverse polar particles (silica particles) was changed to 9.5 parts.
Next, the low-coverage composite particles and the high-coverage composite particles were mixed at a ratio of 50:50 to obtain composite particles 1.

After performing the above-mentioned sonication on the composite particles 1, the coverage of each composite particle is obtained from an image taken by a scanning electron microscope (SEM), and the "number ratio ( _CL : _CM )" is obtained. Was calculated. Further, the particle size of each composite particle is obtained from the image obtained by the scanning electron microscope (SEM), and the composite particle satisfying the formula (1) (1 μm ≦ _RC ≦ (0.45 × _RTN )). And the ratio of the composite particles satisfying the formula (2) ( _RC <1 μm) to the toner particles was determined by the above-mentioned method.
Further, "number ratio _(C +: _{C -)"} by the above-described method were determined.

-Preparation of complex particles 2-4-
In the preparation of the composite particles 1, the "number ratio ( _CL : _CM )" is shown in Table 1 or Table 2 below by changing the mixing ratio of the composite particles having a low coverage and the composite particles having a high coverage. Complex particles were obtained in the same manner as in Complex Particle 1 except that the values were adjusted to be as described.

-Preparation of complex particles 5-6-
In the preparation of the composite particles 1 or 2, the lubricant particles (zinc stearate) used were changed to the following particles having a smaller diameter, and the amount of the antipolar particles in the composite particles having a low coverage was 9.0. Complex particles were obtained in the same manner as in complex particles 1 or 2 except that the amount of antipolar particles in the complex particles having a high coverage was changed to 14.2 parts.
・ Lubricant particles (positively charged)
Fatty acid metal salt particles, zinc stearate particles, trade name: Nissan Elector MZ-2, manufactured by Nissan Oil Co., Ltd., average particle size = 1.0 μm

-Preparation of complex particles 7-
In the preparation of the composite particles 1, the antipolar particles (silica) used were changed to the following, and the amount of the antipolar particles in the composite particles having a low coverage was 4.5 parts, and the composite with a high coverage was used. Complex particles were obtained in the same manner as in complex particles 1 except that the amount of antipolar particles in the body particles was changed to 7.1 parts.
・ Monopole particles (negative charge)
Titanium oxide particles, trade name: MT150AW, manufactured by TAYCA CORPORATION, average particle size = 20 nm

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

-Preparation of complex particles 9-
In the preparation of the composite particles 1, the lubricant particles (zinc stearate) and the inverse polar particles (silica) are prepared by the following method without preparing the composite particles having a low coverage and the composite particles having a high coverage. The mixture was mixed and stirred all at once.
That is, 50 parts of lubricant particles (zinc stearate) and 7.8 parts of reverse electrode particles (silica particles) are mixed, and a powder processing device (Nobilta NOB130, manufactured by Hosokawa Micron) has 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 equipment was temporarily stopped, 50 parts of lubricant particles (zinc stearate) were additionally added, and the cooling water was again added to the jacket at a clearance of 3 mm and a peripheral speed of 1500 rpm. The mixture was blended for 5 minutes while flowing. Then, coarse particles were removed using a sieve having a mesh size of 45 μm to obtain composite particles.

-Preparation of complex particles 10 to 11 (complex particles for comparative examples)-
In the preparation of the composite particles 1, the "number ratio ( _CL : _CM )" is shown in Table 1 or Table 2 below by changing the mixing ratio of the composite particles having a low coverage and the composite particles having a high coverage. Complex particles were obtained in the same manner as in Complex Particle 1 except that the values were adjusted to be as described.

(Preparation of toner particles)
-Preparation of toner particles 1-
[Preparation of amorphous polyester resin particle dispersion]
-Bisphenol A ethylene oxide 2.2 mol additive: 40 mol parts-Bisphenol A propylene oxide 2.2 mol additive: 60 mol part-Telephthalic acid: 47 mol part-Fumaric acid: 40 mol part-Dodecenyl succinic anhydride: 15 mol parts ・ Trimellitic acid anhydride: 3 mol parts In a reaction vessel equipped with a stirrer, a thermometer, a condenser and a nitrogen gas introduction tube, other than fumaric acid and trimellitic anhydride among the above monomer components were put into the reaction vessel. And 0.25 part of tin dioctanoate was added to a total of 100 parts 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 above fumaric acid and trimellitic acid anhydride were added and reacted for 1 hour. The temperature was further raised to 220 ° C. over 4 hours and polymerized under a pressure of 10 kPa until the required molecular weight was obtained to obtain a pale yellow transparent amorphous polyester resin 1.
The obtained amorphous polyester resin 1 has a glass transition temperature Tg of 59 ° C. by DSC, a weight average molecular weight Mw of 25,000 by GPC, a number average molecular weight Mn of 7,000, and a softening temperature of 107 ° C. by a flow tester. The acid value AV was 13 mgKOH / g.

A 3-liter reaction tank with a jacket (manufactured by Tokyo Rika Kikai Co., Ltd .: BJ-30N) equipped with a condenser, a thermometer, a water dripping device, and an anchor wing is maintained at 40 ° C. in a water circulation type constant temperature bath. A mixed solvent of 160 parts of ethyl acetate and 100 parts of isopropyl alcohol was added to the mixture, 300 parts of the amorphous polyester resin 1 was added thereto, and the mixture was stirred at 150 rpm using a three-one motor to dissolve the oil phase. Obtained. 14 parts of a 10% aqueous ammonia solution was added dropwise to the stirred oil phase at a dropping time of 5 minutes, and after mixing for 10 minutes, 900 parts of ion-exchanged water was further added dropwise at a rate of 7 parts per minute to invert the phase. 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 (manufactured by Tokyo Rika Kikai Co., Ltd.) equipped with a vacuum control unit via a trap ball. .. While rotating the eggplant flask, it was heated in a hot water bath at 60 ° C., and the pressure was reduced to 7 kPa while paying attention to sudden boiling to remove the solvent. When the amount of solvent recovered reached 1,100 parts, the pressure was returned to normal pressure, and the eggplant flask was water-cooled to obtain a dispersion. The obtained dispersion had no solvent odor.
The volume average particle diameter D50v of the resin particles in this dispersion was 130 nm. Then, ion-exchanged water was added to prepare the solid content concentration to 20%, which was used as an amorphous polyester resin particle dispersion.

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

In a 3-liter reaction tank with a jacket (manufactured by Tokyo Rika Kikai Co., Ltd .: BJ-30N) equipped with a condenser, a thermometer, a water dropping device, and an anchor wing, 300 parts of the crystalline polyester resin 1 and methyl ethyl ketone (solvent) are added. 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 circulation type constant temperature bath (dissolution solution preparation step). After that, the stirring rotation speed was set to 150 rpm, the water circulation type constant temperature bath 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. was added. A total of 900 parts were added dropwise at a rate of / min to invert the phase 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, it was heated in a hot water bath at 60 ° C., and the pressure was reduced to 7 kPa while paying attention to sudden boiling to remove the solvent. When the amount of solvent recovered reached 1,100 parts, the pressure was returned to normal pressure, and the eggplant flask was water-cooled to obtain a dispersion. The obtained dispersion had no solvent odor.
The volume average particle diameter D50v of the resin particles in this dispersion was 130 nm. Then, ion-exchanged water was added to prepare a solid content concentration of 20%, which was used as a crystalline polyester resin particle dispersion.

[Preparation of colorant particle dispersion]
・ Cyan pigment [PigmentBlue 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 The components of the above were mixed and dispersed for 1 hour with a high-pressure impact disperser Ultimizer [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 mold release agent particle dispersion]
-Paraffin wax [HNP9, manufactured by Nippon Seiko Co., Ltd.]: 50 parts-Anionic surfactant [Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.]: 2 parts-Ion-exchanged water: 200 parts Heat the above components to 120 ° C. , IKA's Ultratarax T50 was sufficiently mixed and dispersed, 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 particles 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 Put the above components in a 3 liter reaction vessel equipped with a thermometer, pH meter and stirrer, and add 1.0% nitric acid at a temperature of 25 ° C to bring the pH to 3.0. After that, 130 parts of an aqueous aluminum sulfate solution was added and dispersed for 6 minutes while dispersing at 5,000 rpm with a homogenizer (manufactured by IKA Japan Co., Ltd .: Ultratarax T50).
After that, a stirrer and a mantle heater are installed in the reaction vessel, and while adjusting the rotation speed of the stirrer so that the slurry is sufficiently agitated, the temperature rise rate is 0.2 ° C./min up to a temperature of 40 ° C., 40. After the temperature exceeded ° C., the temperature was raised at a heating 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). The temperature was maintained when the volume average particle size reached 5.0 μm, and 50 parts of the amorphous polyester resin particle dispersion was charged over 5 minutes.
After holding for 30 minutes, the pH was adjusted to 9.0 using a 1% aqueous sodium hydroxide solution. Then, while adjusting the pH to 9.0 at every 5 ° C., the temperature was raised to 90 ° C. at a heating rate of 1 ° C./min and maintained at 98 ° C. When the particle shape and surface properties were observed with an optical microscope and a scanning electron microscope (FE-SEM), the coalescence of the particles was confirmed at 10.0 hours, so the container was heated to 30 ° C. for 5 minutes with cooling water. It was cooled over.

The cooled toner slurry was passed through a nylon mesh having an opening of 15 μm to remove coarse powder, and the toner slurry that had 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 at a temperature of 30 ° C., which was 10 times the amount of the toner, and stirred and mixed for 30 minutes. Subsequently, the mixture is vacuum-filtered with an ejector, the toner slurry remaining on the filter paper is crushed by hand as finely as possible, poured into ion-exchanged water at a temperature of 30 ° C., which is 10 times the amount of the toner, stirred and mixed for 30 minutes, and then again with an ejector. The filtrate was filtered under reduced pressure, and the electrical conductivity of the filtrate was measured. This operation was repeated until the electrical conductivity of the filtrate became 10 μS / cm or less, and the toner slurry was washed.
The washed toner slurry was finely crushed 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 coefficient 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 problems such as protrusion of the release agent and peeling of the surface layer were observed.

-Preparation of toner particles 2-
In the production of the toner particles 1, the volume average particle size was 4.0 μm, not when the volume average particle size was 5.0 μm, when the “acrystalline polyester resin particle dispersion: 50 parts” was added. Toner particles 2 were produced in the same manner as the toner particles 1 except that the time point was changed.

<Example 1>
(Preparation of toner and developer)
To 1: 100 parts of toner particles, 1: 1.5 parts of composite particles and 1.5 parts of colloidal silica R972 (manufactured by Aerosil Japan) are added and mixed with a Henshell mixer at a peripheral speed of 22 m / s for 3 minutes. Then, toner 1 was obtained.

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

The carrier used was prepared as follows.
-Ferrite particles (volume average particle diameter: 50 μm): 100 parts-Toluene: 14 parts-Stylene-methylmethacrylate 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 were stirred with a stirrer for 10 minutes to prepare a dispersed coating liquid, and then this coating liquid and ferrite particles were mixed. The particles were placed in a vacuum degassing type kneader, stirred at 60 ° C. for 30 minutes, degassed under reduced pressure while further heating, and dried to obtain carriers.

<Examples 2 to 12>
Toners and developing agents 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 (without external addition of lubricant particles) 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 with a Henschel mixer. Mixing for 3 minutes gave toner.
A developer was obtained in the same manner as in Example 1 except that this toner was used.

<Comparative Examples 2-3>
Toners and developing agents 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 lubricant particles and the silica particles were externally added to obtain toner without adding the composite particles 1.
Specifically, 1.5 parts of zinc stearate particles (trade name: zinc stearate, 1.5 μm, manufactured by Wako Pure Chemical Industries, Ltd., average particle size = 1.5 μm) in 1: 100 parts of toner particles. , And 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 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]
400 g of titanium oxide and 750 g of strontium carbonate were mixed wet with a ball mill for 5 hours, and then a dry mixture was formed and calcined at 1300 ° C. for 7 hours. This was mechanically pulverized and classified to obtain strontium titanate particles 1. The volume average particle size was 4.3 nm, and the shape coefficient (SF2) was 370.

The above-mentioned toner particles 1:20 parts, 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 for the composite particles 1, and a composite. 2.5 parts by mass of the silica particles used in the particles 1 were added and mixed with a Henschel mixer at 2000 rpm for 3 minutes to obtain 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 in which the image part and the non-image part are clearly separated is continuously formed, and then the image is formed again in a low temperature environment after being left unattended, abnormal noise caused by vibration of the cleaning blade called chattering occurs. The presence or absence of occurrence was evaluated.
Specifically, the developing agents of each example were housed in the developing apparatus of the image forming apparatus "DocuCenter-III C7600 (manufactured by Fuji Xerox Co., Ltd.)". Using this image forming apparatus, 1000 images in which the right half is solid and the left half is non-image are continuously output on A4 paper as an image in which the image part and the non-image part are clearly separated, and then left overnight. .. The next morning, when 10 solid images are 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 rotating drive photoconductor (image holder) is as follows. It was evaluated according to the evaluation criteria.
・ Evaluation Criteria A (◎): No abnormal noise (inaudible)
B + (○ +): Very slight noise is generated at the start and stop of rotation B (○): Minor noise is generated at the start of rotation, and very slight noise is generated at low speed rotation and stop B- (○-): Minor noise is generated at the start and stop of rotation, and very slight noise is generated at low speed rotation C (△): Minor noise is generated at start, stop and low speed rotation D (×): At start of rotation, low speed Abnormal noise is generated both when rotating and when stopped

-Evaluation of color streaks-
When 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, color streaks (color streaks) are formed in a direction orthogonal to the transport direction of the recording medium. The presence or absence of horizontal streaks) was evaluated.
Specifically, with respect to the image finally formed in the abnormal noise generation evaluation, the presence or absence of color streaks (horizontal streaks) in the direction orthogonal to the transport direction of the recording medium was evaluated according to the following evaluation criteria.
-Evaluation criteria A (◎): No color streaks are confirmed in the image B (○): Very slight color streaks are confirmed in the image, but tolerable C (△): Minor color streaks are confirmed in the image However, acceptable degree D (x): Clear color streaks are confirmed in the image, which is unacceptable.

-Evaluation of difference in lubricant amount between image and non-image areas-
In the abnormal noise generation evaluation, the surface of the photoconductor (image holder) after being left overnight was observed, and the difference in the abundance of lubricant particles between the part corresponding to the image part and the part corresponding to the non-image part. Was evaluated according to the following evaluation criteria.
The part corresponding to the image part and the part corresponding to the non-image part of the blade nip part on the surface of the photoconductor are tape-transferred, respectively, and a scanning electron microscope (SEM, manufactured by Hitachi, Ltd .: S-4100) is used at a magnification of 1000 times. The number of lubricant particles was counted, and the number of lubricant particles was compared between the portion corresponding to the image portion and the portion corresponding to the non-image portion.
-Evaluation Criteria A (◎): The number of lubricant particles in the area corresponding to the image area is within ± 10% of the number of lubricant particles in the area corresponding to the non-image area B (○): The area corresponding to the image area The number of lubricant particles in the above is 70% or more and less than 90%, or more than 110% and 130% or less of the number of lubricant particles in the non-image area C (Δ): Lubricant in the image area. 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 , Less than 50% or more than 150% of the number of lubricant particles in the area corresponding to the non-image area

In the above table, the formula (1) refers to “1 μm ≦ _RC ≦ (0.45 × R _TN )”, and the formula (2) refers to “ _RC <1 μm”.

From the above results, in this example, as compared with the comparative example, when an image in which the image portion and the non-image portion are clearly separated is continuously formed, and then the image is formed again in a low temperature environment after being left to stand. , It can be seen that the occurrence of color streaks (horizontal streaks) is suppressed.

1Y, 1M, 1C, 1K photoconductor (example of image holder)
2Y, 2M, 2C, 2K charging roll (example of charging means)
3 Exposure device (an example of static charge image forming means)
3Y, 3M, 3C, 3K laser beam 4Y, 4M, 4C, 4K developing device (example of developing means)
5Y, 5M, 5C, 5K primary transfer roll (example of primary transfer means)
6Y, 6M, 6C, 6K Photoreceptor 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 Injection Port 16 Liquid Addition Port 18 Discharge Port 20 Intermediate Transfer Belt (Example of Intermediate Transfer Belt)
22 Drive roll 24 Support roll 26 Secondary transfer roll (an example of secondary transfer means)
30 Intermediate transfer member cleaning device 107 Photoreceptor (example of image holder)
108 Charging roll (an example of charging means)
109 Exposure device (an example of static charge image forming means)
111 Developing equipment (an example of developing means)
112 Transfer device (an example of transfer means)
113 Photoreceptor cleaning device (an example of cleaning means)
115 Fixing device (an example of fixing means)
116 Mounting rail 118 Opening for exposure 117 Housing 200 Process cartridge 300 Recording paper (an example of recording medium)
P Recording paper (an example of recording medium)
TN Toner Particle C Composite Particle

Claims (11)

Toner particles and
A composite particle containing a lubricant particle and a reverse pole particle having a charge opposite to that of the lubricant particle, and the reverse pole particle is fixed to the surface of the lubricant particle to form a composite.
Including
Among the complex particles, the number ratio (C ₊ : C ₋ ) of the positively charged complex particles [C ₊ ] and the negatively charged complex particles [C ₋ ] is 30:70 to 70 :. Toner for static charge image development in the range of 30. Among previous SL composite particles, the lubricant composite particles [C 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 number ratio of _{M] (C} L: C _M) is an electrostatic image developing toner according to claim 1 in the range of 30:70 to 70:30. The toner for static charge image development according to claim 2, wherein in the composite particles, the average coverage of the lubricant particles on the surface by the antipolar particles is 20% or more and 60% or less. When the number distribution of the coverage in the composite particles is graphed (horizontal axis = coverage, vertical axis = number), peaks occur in both the region with a coverage of less than 40% and the region with a coverage of 40% or more. The static charge image developing toner according to claim 2 or 3, which is present. Among the composite particles, the ratio of the composite particles satisfying the condition of the following formula (1) to the number of the toner particles is 0.006% by number or more, and the composite particles satisfying the condition of the following formula (2). The toner for static charge image development according to any one of claims 1 to 4, wherein the ratio to the number of toner particles is 0.001% by number or less.
Equation (1) 1 μm ≤ _RC ≤ (0.45 × R _TN )
Equation (2) _RC <1 μm
(In the above formulas (1) and (2), R _TN represents the volume average particle diameter (μm) of the toner particles, and _RC represents the particle diameter (μm) of the composite particles.) The toner for static charge image development according to any one of claims 1 to 5, wherein the lubricant particles are zinc stearate particles and the reverse electrode particles are silica particles. A static charge image developer containing the toner for static charge image development according to any one of claims 1 to 6. The toner for developing an electrostatic charge image according to any one of claims 1 to 6 is accommodated.
A toner cartridge that is attached to and detached from the image forming device. A developing means for accommodating the electrostatic charge image developing agent according to claim 7 and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic charge image developing agent is provided.
A process cartridge that is attached to and detached from the image forming device. Image holder and
A charging means for charging the surface of the image holder and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
A developing means for accommodating the electrostatic charge image developer according to claim 7 and developing the electrostatic charge image formed on the surface of the image holder as a toner image by the electrostatic image developer.
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
A cleaning means for cleaning the surface of the image holder by bringing the cleaning blade into contact with the image holder.
An image forming apparatus comprising. The charging process that charges the surface of the image holder,
A static charge image forming step of forming a static charge image on the surface of the charged image holder, and
A developing step of developing an electrostatic charge image formed on the surface of the image holder as a toner image by using the electrostatic charge image developer according to claim 7.
A transfer step of transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A fixing step of fixing the toner image transferred to the surface of the recording medium, and
A cleaning step of bringing a cleaning blade into contact with the image holder to clean the surface of the image holder.
An image forming method having.