JP2017173804A - Toner, toner storage unit, image formation apparatus, and image formation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide toner which never forms an abnormal image due to filming with external additives on a photoreceptor and also has superior cleaning properties even when repeatedly used for a long time, specially, in a low-temperature, low-humidity environment.SOLUTION: The present invention relates to toner which contains base particles and external additives sticking on the base particles, the toner satisfying conditions 1 and 2 when a number distribution D of particle sizes of powder particles B produced one base particle A is calculated from a density "a" of base particles A sticking on an adhesion place and a density "b" of the powder particles B sticking on mica after the toner is thrown in a pressure-reduced space from a throw-in opening and caused to strike on a substrate surface having the adhesion place composed of a carbon tape and the mica, the surface being arranged orthogonally to a direction connecting the center of the pressure-reduced space and the center of the throw-in opening. In the condition 1, the powder particles are particles released from the base particle, where the number distribution D has a maximum of the number of the powder particles B in a range of every 25nm of larger than 125 nm to 150 nm, larger than 150 nm to 175 nm, or larger than 175 nm to 200 nm in a graph having a lateral axis representing a range of every 25 nm in particle diameter and a longitudinal axis representing the numbers of the powder particles B. In the condition 2, the number distribution D shows 30% or less of the number of particles of 125 nm or les sin particle size.SELECTED DRAWING: None

Description

  The present invention relates to a toner, a toner storage unit, an image forming apparatus, and an image forming method.

  Conventionally, toner used for image formation such as electrophotography has externally added inorganic fine particles to toner base particles in order to ensure transportability and chargeability in the image forming apparatus.

However, if the inorganic fine particles externally added to the toner are embedded in the toner base particles due to stress with the conveying member during toner conveyance in the developing device, the toner fluidity is impaired, and toner replenishment property, Developability and chargeability deteriorate with time. Further, the image density is lowered during long-term repeated use.
In addition, if the external additive is liberated from the toner during the development, not only does the toner chargeability and flowability decrease, the image density decreases and the development becomes clogged, but the toner adheres to the developing roller and is fixed. The amount of toner drawn up at the location where the toner is fixed decreases, and an abnormal image is generated.
In addition, when the external additive is released from the toner at the time of transfer to the photosensitive member or the intermediate transfer belt, the external additive forms a film on the entire photosensitive member or the intermediate transfer belt. Optical and electrical characteristics are degraded and abnormal images are likely to be generated. The image forming apparatus is generally provided with a cleaning mechanism for removing filming substances deposited on the photosensitive member and the intermediate transfer belt. However, the cleaning function is deteriorated particularly in a low-temperature and low-humidity environment. .
On the other hand, it is difficult to completely suppress the liberation of toner external additives during image formation. In addition, when an appropriate amount of external additive is supplied onto the photoconductor or intermediate transfer belt, the supplied external additive is preferable for cleaning the surface of the photoconductor or intermediate transfer belt.

In recent years, in order to reduce the particle size and spheroidization of the toner, the toner is granulated in a liquid, including a toner produced by a suspension polymerization method, an emulsion polymerization method, a dispersion polymerization method, or the like. Many methods for manufacturing the same In particular, in the case of a toner having a small particle diameter, the surface area of the toner base particles is relatively large. Therefore, in order to ensure fluidity, it is necessary to increase the amount of the external additive added. The liberation of the external additive is likely to occur, and there is a problem that filming of the external additive increases. Therefore, there is a demand for a toner that does not release the external additive until the toner is put into the developing device, and that is released from an appropriate amount of toner when the toner is transferred to the photoreceptor or the intermediate transfer belt.
As described above, it is very important to consider how the external additive is released from the toner in order to continuously form a high-quality image. As a method for obtaining the ease of release of the external additive from the toner, for example, ultrasonic vibration is applied to the toner dispersion, and the external additive released from the weight change of the toner after the external additive released from the toner is removed. A wet method for obtaining the proportion of the additive is disclosed (for example, see Patent Documents 1 and 2).

  The present invention provides a toner that does not generate an abnormal image due to filming by an external additive on a photoreceptor and has excellent cleaning properties even when used repeatedly for a long period of time in a low temperature and low humidity environment. For the purpose.

Means for solving the above-described problems are the following toners. That is,
The toner of the present invention is a toner containing base particles and an external additive attached to the base particles,
Adhesive spot made of carbon tape, the surface of which is placed so as to be orthogonal to the direction connecting the center of the decompression space and the center of the introduction port, by introducing the toner into the decompression space from the entrance. From the density a of the base particles A adhering to the adhesive portion and the density b of the following powder particles B adhering to the mica from one of the base particles A The following conditions 1 and 2 are satisfied when the number distribution D of the particle diameters of the generated powder particles B is calculated.
Powder particles B: particles separated from the base particles Condition 1: When the number distribution D is plotted, the horizontal axis is a range of particle diameters every 25 nm and the vertical axis is the number of the powder particles B The number of the powder particles B has a maximum value in any of the ranges of 25 nm to 150 nm, 150 nm to 175 nm, and 175 nm to 200 nm.
Condition 2: In the number distribution D, the number of particles having a particle diameter of 125 nm or less is 30% or less.

  According to the present invention, there is provided a toner that does not generate an abnormal image due to filming by an external additive on a photoreceptor and has excellent cleaning properties even when used repeatedly for a long period of time in a low temperature and low humidity environment. can do.

FIG. 1 is an example of a graph for obtaining the number distribution D. FIG. 2A is an example diagram for explaining a vacuum dispersion type image analysis method in which toner collides with a substrate. FIG. 2B is an example diagram for explaining a vacuum dispersion type image analysis method in which toner collides with a substrate. FIG. 2C is an example diagram for explaining a vacuum dispersion type image analysis method in which toner collides with a substrate. FIG. 2D is an example diagram for explaining a vacuum dispersion type image analysis method in which toner collides with a substrate. FIG. 2E is an example for explaining a vacuum dispersion type image analysis method in which toner collides with a substrate. FIG. 3 is an example diagram showing a scanning electron microscope (SEM) image of the toner on the carbon tape. FIG. 4 is an example diagram showing a scanning electron microscope (SEM) image of toner on mica. FIG. 5 is a schematic configuration diagram showing an example of the image forming apparatus of the present invention. FIG. 6 is a schematic configuration diagram showing an example of the image forming apparatus of the present invention. FIG. 7 is a schematic configuration diagram showing an example of a tandem color image forming apparatus which is another image forming apparatus of the present invention. FIG. 8 is a schematic configuration diagram showing an example of a tandem type color image forming apparatus which is another image forming apparatus of the present invention. FIG. 9 is a schematic configuration diagram showing an example of a tandem type color image forming apparatus which is another image forming apparatus of the present invention.

(Toner and powder)
The toner of the present invention contains at least base particles and an external additive, and further contains other components as necessary.
The powder of the present invention contains at least base particles and an external additive, and further contains other components as necessary.
Hereinafter, the toner of the present invention will be described. However, in the following description, “toner” is replaced with “powder” to also serve as an explanation of the powder of the present invention.

The wet method disclosed in Japanese Patent No. 3129074 and Japanese Patent Application Laid-Open No. 2014-174341 can determine the ease of liberating external additives, but the measurement variation is very large. In many cases, there was no correlation with the degree of filming of the external additive on the photoreceptor due to the liberation of the external additive. In addition, since it was not known at all how the external additive was released, it was not known whether the defect was due to the release of the external additive. In fact, despite the fact that the same toner is used, it is impossible to explain that the occurrence of a problem changes simply by changing the members such as the carrier, the developing roller, the photoconductor, and the intermediate transfer belt. No stable image could be obtained.
The present invention has been made in view of such problems of the prior art.

The toner or powder is introduced into the decompression space from the inlet, and is made to collide with the surface of the substrate having the adhesive spot made of carbon tape and the mica, so that the base particles A attached to the adhesive spot When the number distribution D of the particle diameters of the powder particles B generated from one of the base particles A is calculated from the density a and the density b of the following powder particles B attached to the mica, the following conditions are satisfied. Satisfy 1 and 2.
Powder particles B: particles separated from the base particles Condition 1: When the number distribution D is plotted, the horizontal axis is a range of particle diameters every 25 nm and the vertical axis is the number of the powder particles B The number of the powder particles B has a maximum value in any of the ranges of 25 nm to 150 nm, 150 nm to 175 nm, and 175 nm to 200 nm.
Here, the surface of the substrate is arranged so as to be orthogonal to a direction connecting the center of the decompression space and the center of the inlet. The said substrate surface has a location comprised from the adhesion location comprised from the carbon tape as a location which has adhesiveness, and mica.

The present inventors have found that a toner satisfying the above conditions does not generate an abnormal image due to filming due to an external additive on the photosensitive member even when used repeatedly over a long period of time, particularly in a low temperature and low humidity environment, and cleaning is performed. It has been found that the toner is excellent in properties.
Based on the recognition that the ease of liberation of the external additive from the toner greatly contributes to the occurrence of filming and cleaning properties, the present inventors have paid particular attention to the characteristics of the external additive. Repeated. Thus, it has been found that liberation of the external additive from the toner basically occurs when the toner collides with something. Further, it has been found that the liberation of the external additive from the toner changes depending on the hardness of the substrate on which the toner collides.

  It is necessary to control the adhesion state of the external additive as part of the surface modification and surface treatment for controlling the powder mobility of the base particles. The external additive may require a function of moving in synchronism with the base particles and a function of exerting by appropriate separation, but these are contradictory properties. Controlling these conflicting characteristics is one important characteristic that is closely related to the movement of the toner powder, particularly in the electrophotographic process. To put it in an extreme way, if it is only necessary to synchronize with the base particle, it is sufficient to be completely immobilized on the surface of the base particle, and if it is easy to leave from the base particle, it is simply mixed. It may be in a state (including an attached state or an intervening state).

  The present inventors control the presence of the surface treatment agent (external additive) necessary for dry powder handling with the base particles (powder) and the stable state against disturbance, stress load, change, etc. I was looking for methods and means that could be achieved. In view of this, the inventors have found a technique that can indicate the state of adhesion of external additives in a dry process as a distribution.

  In the electrophotographic process, the development and transfer mainly consist of a mechanism in which the toner and the external additive move synchronously to the developing device, the photosensitive member, the (intermediate transfer member), and the paper. Additives are a major factor in component contamination. On the other hand, blade cleaning or the like is mainly used for cleaning. However, when cleaning toner particles, a certain amount of external additive is required to be deposited on the wedge portion between the blade and the member contact. Supply is required. In addition, since the supplied external additive tends to be an item that conflicts with member contamination, the selectivity and control of the supplied particles are also required. For that purpose, it is necessary to discriminate a state in which the particles are separated from the base particles or are easily separated, and to further quantify the distribution.

<About powder particle B>
Although the powder particle B depends on the collision condition, the external additive released from the base particle mainly occupies the combination of the present condition and the toner.
However, there is a possibility that the powder particles B may include fragments or fine powders that are partially missing the base particles. Considering their number and particle size, they often deviate more than the particle size region of the external additive, and even if the powder particles B are partially mixed with fragments or fine powder lacking the base particles, Is quite small and is unlikely to affect judgment.
Therefore, in the present invention, the powder particle B mainly refers to an external additive that is fixed or adhered to the surface of the toner base particle before being put into the reduced pressure space.
In addition, it indicates how much the powder particles B are separated from each toner on average and what kind of particle size distribution is present, whether the particles are single particles or aggregates, It can be utilized as a development and control means for obtaining desirable characteristics by obtaining information as to whether it is caused by an external additive.

<About the measurement method of the number distribution D>
The number distribution D is measured by the following method.
By the method described in the item <SEM observation> described later, the number density of the toner and the detached particles is determined from the SEM image in a certain region, the number of powder particles B per toner is set, and the number of the separated particles The binarization is performed from the image analysis by the image analysis by the apparatus printing software, and the individual particle size is determined to calculate the number distribution D.
In the image processing, an image of 500 to 5,000 times is preferable as the toner particles, and an image of 5,000 to 30,000 times is preferable in the detached particle portion, and may be adjusted according to the size of the particles. However, if the magnification is increased too much, it becomes difficult to obtain the count number. If the magnification is too small, the detection accuracy in image analysis tends to vary and the determination becomes difficult. More preferably, in the case of toner, the toner particles are 1,000 to 2,000 times, and the detached particles are 15,000 to 25,000 times.
For example, 10 sheets of 2,000 times are selected for toner particle analysis and 10 sheets of 2,000 times are selected for detached particle analysis, and 50 nm is set as a threshold in image analysis.
-X axis: Particle diameter of powder particle B-Y axis: Number of powder particles B per toner (piece / toner)
For example, as shown in FIG.
In FIG. 1, the plot of the particle diameter of 75 nm is the X cumulative data of 50 nm <X ≦ 75 nm.
Further, by plotting by dividing into 25 nm, the cumulative number of particles having a particle diameter of 500 nm or less is 674 and the cumulative number of particles having a particle diameter of 125 nm or less is 111 from the number at each threshold.
Therefore, the number of particles having a particle diameter of 125 nm or less is 111/674 × 100 = 16.5%. The peak top is 150 nm.
That is, the number distribution D is obtained by measuring the particle diameter of 500 nm or less with respect to the number of the powder particles B, and determining the number of the powder particles B by dividing the range by every 25 nm. It is a number distribution.

<About Condition 1>
As a result of investigations by the present inventors, it has been found that it is necessary to satisfy the above condition 1 in order to achieve both prevention of member contamination and good cleaning properties.
When there are many powder particles B with a small particle diameter (about 125 nm or less), the occurrence of member contamination, filming, and deterioration of cleaning properties (slip-through) are likely to occur.
When there are many powder particles B having a large particle size (about 200 nm or more), the polishing power of one particle increases, but it tends to be a starting point for damage, whether it is rough or damaged. In addition, it also affects the charge, such as repeated detachment and adhesion from the toner and shifting to a member or carrier. Furthermore, adhesion to members, clogging in dead zones and voids are likely to occur.

In addition, as a method for satisfy | filling the said condition 1, the following methods are mentioned, for example.
The toner is surface-modified by controlling the shape of the toner particles, applying an external additive, and the like, thereby adjusting the properties as a powder.
As the surface modification by applying the external additive, for example, there is a method of adjusting the dispersion state and the degree of immobilization of the external additive. As a method for adjusting the dispersion state and the degree of immobilization, it is preferable to select a method having both practicality and productivity. In the case of a polymerized toner prepared by dispersing toner particle materials containing an external additive in an aqueous medium, the degree of hydrophobicity and pH are adjusted while adjusting the temperature in the aqueous medium, and the external additive is applied to the surface. An immobilization method is efficient. In addition, when a solvent etc. are mixed in the said aqueous medium, it can adjust similarly. It can also be adjusted by putting dry powder in an aqueous solution or dilute solvent, but it is easier to control the dispersion state and degree of immobilization by applying heat than by swelling the toner surface with a solvent. There is.
On the other hand, in the case of pulverized toner produced by dry pulverizing the material of toner particles containing external additives, a temperature-adjustable unit is attached to the jacket cooling part of a general mixing mixer, or the shape of the deflector and blades are changed. Things (super mixer, Henschel mixer, Q mixer, etc.), hybridization, etc. may be used, and the degree of immobilization can be adjusted by adjusting the share (mechanical load) and heating / temperature. However, when giving these relatively high shares, temperature management considering the Tg of toner and the content of low-melting-point substances is particularly important, which makes a trade-off between control of the degree of fixation and productivity. Cheap. In view of this, as a method that is dry, has a degree of freedom in powder selection and a high degree of fixation, and can achieve both high productivity, for example, a heat treatment apparatus utilized as a shape control means can be mentioned. A means for fixing the external additive by adjusting the heating temperature to such an extent that the toner shape is not substantially changed is more effective, and further, the fine particles for which the degree of fixation is desired to be adjusted in the pretreatment before the heat treatment, that is, the external additive It is more preferable that the dispersion state is appropriately set, and then it is possible to obtain an arbitrary dispersion state and a high degree of immobilization using the heat treatment apparatus. Moreover, you may select suitably according to the objective, such as processing an additive further with a mixer etc. as needed, and may combine.
The range in which the number of the powder particles B in the condition 1 has the maximum value is preferably more than 125 nm and not more than 150 nm, and more preferably more than 150 nm and not more than 175 nm.

<Condition 2>
A component having a small particle diameter (about 125 nm or less) is efficient in terms of imparting fluidity and surface coating. However, when a relatively large amount of a small particle size is supplied to the wedge portion (external additive layer, packing layer) of the cleaning portion, the tip portion is rearranged in order of particle size, and packing is further performed. . Filming, member contamination, and slipping through the blade are more likely to be present at the front end of the wedge as the particle size of the external additive becomes smaller. The external additive slips more easily when it is affected by vibration, strain, rotation, etc., and also easily enters minute irregularities including minute irregularities. Further, it is preferable to suppress the addition amount as much as possible within a necessary range in order to promote filming, scratches, fixing to the photosensitive member by the load of the cleaning blade received during slipping.
From this point, in the present invention, it is necessary to satisfy the condition 2.
The particle diameter of the powder particle B includes not only primary particles but also secondary particles (aggregates). That is, in the number distribution D of the powder particles B, the secondary particles are counted as one particle.
In determining the condition 2, there is no problem in quantification of 25 nm (over 0 nm to 25 nm) and 50 nm (over 25 nm to 50 nm) as long as it can be discriminated on the basis of image analysis. In many cases, it is difficult to distinguish between and 66 nm.
That is, in the present invention, the condition 2 is defined as 66 nm <T ≦ 125 nm as a detection count and T is 30% or less.
The number in the condition 2 is 30% or less, but is preferably 3% to 25%, more preferably 3% to 20% from the viewpoint of achieving both cleaning properties and filming resistance.

<Vacuum dispersion type image analysis method>
A method of causing the toner and powder to collide with the substrate surface in the toner and powder evaluation method of the present invention will be described with reference to FIGS. 2A to 2E.
A toner sample 81 is placed on the upper part of the disperser (see FIG. 2A), the inside of the disperser is depressurized to 10 kPa (see FIG. 2B) by the vacuum pump 83 (see FIG. 2B), and then a gap is formed on the upper part of the disperser. The toner sample 81 is sucked into the disperser (see FIG. 2C). After being left for 1 minute (see FIG. 2D), the inside of the disperser is brought to normal pressure (see FIG. 2E), and the substrate (pin stub) 82 is taken out.
When evaluating the toner of the present invention, the toner is introduced together with a very small amount of air from the top of the disperser, but since the inside of the disperser is a decompression space, the air resistance in the disperser is very low, so the top of the disperser The toner hits the substrate linearly at high speed.
On the substrate on which the toner collides, there are provided at least one place having adhesiveness and one place harder than the place having adhesiveness. The toner is captured at the sticky portion. When the toner collides with a sticky part, fine particles (external additive) may be released from the toner base particle, but the toner base particle needs to be attached to the sticky part. Therefore, the material of the part having adhesiveness is not particularly limited as long as the toner base particles can be reliably attached, and can be appropriately selected according to the purpose. In consideration of observation with a scanning electron microscope (SEM), it is preferable to use a carbon tape for SEM observation that generates less gas and can reliably capture base particles.
Since the harder portion than the sticky portion is not sticky, most of the toner base particles are not fixed on the hard portion. However, the fine particles (external additive) adhering to the toner base particles remain on the hard part due to electrostatic force, intermolecular force, and the like because of their small size. As the material of the harder part than the sticky part, a material used in a part where the toner may collide in the image forming apparatus may be appropriately selected, but mica is preferably used.

When the toner is evaluated, it is preferable to use a toner sample having a number average particle diameter in the range of 0.5 μm to 200 μm as a toner sample to be put into the disperser. Moreover, it is preferably 1 μm to 100 μm, more preferably 2 μm to 50 μm. This is because when the number average particle diameter of the toner sample put into the disperser is within the above range, an accurate measurement result can be obtained in evaluating filming of the external additive.
In the decompression space in the toner evaluation method of the present invention, the inner diameter of the disperser is preferably 50 mm to 200 mm, and more preferably 70 mm to 150 mm, considering pressure resistance and the spread of particles to be introduced. The height of the decompression space is preferably 75 mm to 300 mm, and more preferably 100 mm to 260 mm. If the height of the decompression space is 75 mm or more, the dispersion of particles is uniform, and if the height is 260 mm or less, the space can be decompressed in a short time, and a large vacuum pump is not required.
In the toner evaluation method of the present invention, the degree of vacuum in the reduced pressure space is preferably 20 kPa or less, and more preferably 5 kPa to 15 kPa. When the degree of vacuum in the decompression space is 20 kPa or less, it is possible to prevent the problem that the toner particles thrown into the decompression space are subjected to air resistance and the energy colliding with the substrate is weakened.
As a disperser used for evaluating the toner of the present invention, a disperser NEBULA 1 (manufactured by Phenom-World) is preferable because of excellent handling and dispersion reproducibility.

The density (a (number / mm ² )) of toner particles per unit area of the toner collided on the substrate can be determined from the number of toner base particles adhering to the sticky portion. Even if the external additive is released from the toner adhering to the sticky part, the number average particle diameter of the external additive is overwhelmingly smaller than that of the toner as described above. Thus, only the toner can be determined.
Further, the number of external additives b / a released from one toner is calculated from the density (b (pieces / mm ² )) of the external additive adhering to a place harder than the sticky place, and b / The quality of the toner can be determined by the value of a.
Since it is difficult to measure the number of toners and external additives that are harder than the adhesive part and the adhesive part with an optical means, a scanning electron microscope (SEM) is used.

  In SEM, since the shape of each external additive is known, not only the particle diameter of the external additive but also particle diameter parameters such as circularity, convexity, and aspect ratio can be obtained.

In this invention, the location which has adhesiveness is made into a carbon tape, and a location harder than it is made into mica.
Specifically, a SEM carbon double-sided tape E3605 (EM Japan) is attached to the surface of an aluminum pin stub (EM Japan) of φ25 mm × 8 mm, and mica punched to φ10 mm is attached thereon.
This pin stub is installed in the disperser NEBULA 1 (Phenom-World), the toner is raised at the sample inlet of the disperser, the pressure inside the disperser is reduced to 10 kPa, and the Φ25 mm sample inlet is opened for about 0.1 second. Then, the toner is introduced into the disperser. By introducing the toner sample, the pressure in the disperser rises to 20 kPa. Under such conditions, the toner collides with the air flow of about 7.3 m / sec on the substrate of the pin stub. Next, after maintaining the state for 1 minute, the inside of the disperser is brought to normal pressure, and the pin stub is taken out. When normalizing the inside of the disperser, air is introduced into the disperser at a speed of about 10 kPa / 5 seconds.
Results of particle size distribution measurement with particle metric software (manufactured by PHENOM-WORLD) and particle size software (manufactured by PHENOM-WORD) Is described.

<SEM observation>
In the SEM observation of the toner on the carbon tape, 10 SEM photographs were taken at random in a visual field area of 181 μm square. One SEM photograph taken at 181 μm square is shown in FIG. Only toner particles were observed on the carbon tape, and no liberation of external additives could be observed.
When the total number of toners for 10 SEM photographs was measured with particle metric software, it was found that toner particles were present at a density of 586 particles / mm ² .
Similarly, 10 SEM photographs were taken on a mica with a 13.5 μm square field of view. Although SEM photographs were taken at random, a place where there was no toner in the SEM pictures was selected and photographed. An example of the SEM photograph on mica is shown in FIG.
Many external additives were observed on the mica. When the total number of external additives for 10 SEM photographs was measured using particle metric software, it was found that the external additives were present at a density of 847,736 / mm ² .
As a result, in this toner, it was found that 1,446 external additives were released from one toner particle.
The liberation of the external additive is the largest where the toner collides with the mica, but the collision causes damage to the mica plate and makes it difficult to distinguish it from the liberated external additive. Further, since the toner itself is debris and it is difficult to distinguish it from the external additive, the SEM image is acquired by removing the location where the toner collides.
The density a of the toner particles per unit area of the toner collided on the substrate is preferably 300 / mm ^{2 to} 1,200 / mm ² , and 500 / mm ^{2 to} 1,200 / mm ^2. More preferred. When the density of the toner at the time of toner dispersion is 300 / mm ^{2 to} 1,200 / mm ² , the following problems can be prevented.
・ The problem is that the number of areas where toner is not dispersed becomes too large and the number of liberated external additives is reduced. ・ The problem that it is difficult to remove the part where the toner collides and to acquire the SEM image. The number of free powder particles B) is preferably 200 to 1,800, more preferably 200 to 1,500, and even more preferably 300 to 1,200 per toner particle. In the case of 200 to 1,800 or more per toner particle, the following problems can be prevented.
・ Embedded inorganic fine particles (powder particles B) in the toner base become noticeable, causing aggregation between the toners, resulting in black spots and uneven image density. The problem of white spots occurring due to filming

<Base particles>
The base particles contain, for example, a binder resin, and may further contain other components such as a colorant, a release agent, and a charge control agent as necessary.
<< Binder resin >>
The binder resin is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a styrene resin (a styrene or a homopolymer or copolymer containing a styrene substitution product), a vinyl chloride resin, and styrene. / Vinyl acetate copolymer, rosin modified maleic acid resin, phenol resin, epoxy resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene / ethyl acrylate copolymer, xylene resin, polyvinyl butyral Examples thereof include resins, petroleum resins, and hydrogenated petroleum resins.
Examples of the styrene resin (a homopolymer or copolymer containing styrene or a styrene-substituted product) include polystyrene, chloropolystyrene, poly α-methylstyrene, styrene / chlorostyrene copolymer, styrene / propylene copolymer, and styrene. / Butadiene copolymer, styrene / vinyl chloride copolymer, styrene / vinyl acetate copolymer, styrene / maleic acid copolymer, styrene / acrylic acid ester copolymer (styrene / methyl acrylate copolymer, styrene / Ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / octyl acrylate copolymer, styrene / phenyl acrylate copolymer, etc.), styrene / methacrylic acid ester copolymer (styrene / methyl methacrylate) Copolymer, styrene / ethyl methacrylate copolymer , Styrene / butyl methacrylate copolymer, a styrene / phenyl methacrylate copolymer), styrene / alpha-chloromethyl acrylate copolymer, and styrene / acrylonitrile / acrylic acid ester copolymer.
There is no restriction | limiting in particular as a manufacturing method of these resin, It can select suitably, For example, block polymerization, solution polymerization, emulsion polymerization, suspension polymerization, etc. can be utilized.
These resins are not limited to single use but can be used in combination of two or more.

The binder resin used in the present invention is more preferably a polyester resin from the viewpoint of low-temperature fixability. As the polyester resin, for example, those usually obtained by condensation polymerization of an alcohol component and a carboxylic acid component can be used.
Examples of the alcohol component include glycols, 1,4-bis (hydroxymethyl) cyclohexane, ethylated bisphenols such as bisphenol A, other dihydric alcohol monomers, and trihydric or higher polyhydric alcohol monomers. Etc.
Examples of the glycols include ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol.
Examples of the carboxylic acid component include divalent organic acid monomers and trivalent or higher polyvalent carboxylic acid monomers.
Examples of the divalent organic acid monomer include maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, and malonic acid.
Examples of the trivalent or higher polyvalent carboxylic acid monomer include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, and 1,2 1,4-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxypropane, 1,2,7,8-octanetetracarboxylic acid and the like.
In particular, the polyester resin preferably has a glass transition point Tg of 55 ° C. or higher, more preferably 60 ° C. or higher, in view of heat resistant storage stability.
The DSC measurement (endothermic peak or glass transition point Tg) in the present invention is measured by using a differential scanning calorimeter (“DSC-60”; manufactured by Shimadzu Corporation) and increasing the temperature to 20 to 150 ° C. at 10 ° C./min. .

-Combined use of crystalline polyester resin-
When crystalline polyester is contained in the binder resin, low-temperature fixability and heat-resistant storage stability can be imparted to the toner due to its sharp melt property.

The crystalline polyester resin refers to a polyester resin that has a particularly high ratio of taking a crystal structure in which the main chain is regularly oriented, and the viscosity of the resin changes greatly in the vicinity of the melting point.
Examples of the crystalline polyester resin include, as an alcohol component, a saturated aliphatic diol compound having 2 to 12 carbon atoms (particularly 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1, 10-decanediol, 1,12-dodecanediol, and derivatives thereof) and a dicarboxylic acid having 2 to 12 carbon atoms having a double bond (C = C bond) as an acid component, or 2 to 2 carbon atoms 12 saturated dicarboxylic acids (especially fumaric acid, 1,4-butanedioic acid, 1,6-hexanedioic acid, 1,8-octanedioic acid, 1,10-decanedioic acid, 1,12-dodecanedioic acid, And crystalline polyester resins synthesized using these derivatives).
Among them, in particular, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, and 1 in that the difference between the endothermic peak temperature and the endothermic shoulder temperature is further reduced. , 12-dodecanediol alcohol component, fumaric acid, 1,4-butanedioic acid, 1,6-hexanedioic acid, 1,8-octanedioic acid, 1,10-decanedioic acid, And 1,12-dodecanedioic acid, preferably only one kind of dicarboxylic acid component.
The molecular structure of the crystalline polyester resin can be confirmed by X-ray diffraction, GC / MS, LC / MS, IR measurement, etc. in addition to NMR measurement by solution or solid.

<<< Colorant >>>
Examples of the colorant used in the toner of the present invention include carbon black, lamp black, iron black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G, rhodamine 6C lake, calco oil blue, chrome yellow, quinacridone, and benzidine yellow. Conventionally known dyes and pigments such as dyes and pigments such as rose bengal and triallylmethane dyes can be used. These can be used alone or in combination, and can be used as black toner or full color toner.
The content of these colorants is preferably 1% by mass to 30% by mass and more preferably 3% by mass to 20% by mass with respect to the binder resin of the toner.

<<< release agent >>>
A conventionally well-known thing can be used as said mold release agent. For example, low molecular weight polyethylene, low molecular weight polypropylene and other low molecular weight polyolefin waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax, beeswax, carnauba wax, candelilla wax, rice wax, montan wax and other natural waxes, Examples include petroleum waxes such as paraffin wax and microcrystalline wax, higher fatty acids such as stearic acid, palmitic acid and myristic acid, metal salts of higher fatty acids, higher fatty acid amides, synthetic ester waxes, and various modified waxes thereof.
Among these release agents, carnauba wax and its modified wax, polyethylene wax, and synthetic ester wax are preferably used.
These release agents can be used alone or in combination of two or more.
The content of these release agents is preferably 2% by mass to 15% by mass, and more preferably 2.5% by mass to 10% by mass with respect to the binder resin of the toner. If it is 2% by mass or more, there is an effect of preventing hot offset, and if it is 15% by mass or less, it is possible to prevent deterioration of transferability and durability.
The melting point of the release agent is preferably 60 ° C to 150 ° C, and more preferably 65 ° C to 120 ° C. If it is 60 degreeC or more, the fall of the heat-resistant storage stability of a toner can be prevented. If it is 150 degrees C or less, the effect of releasability can be exhibited.

<<< Charge Control Agent >>>
The base particles can be blended with a charge control agent as required.
Examples of charge control agents include modified products of nigrosine and fatty acid metal salts, onium salts such as phosphonium salts and lake lakes thereof, triphenylmethane dyes and lake lake pigments, metal salts of higher fatty acids; dibutyltin oxide, dioctyltin oxide Diorganotin oxides such as dicyclohexyltin oxide; diorganotin borates such as dibutyltin borate, dioctyltin borate, dicyclohexyltin borate, organometallic complexes, chelate compounds, monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, Examples include aromatic dicarboxylic acid metal complexes, quaternary ammonium salts, and salicylic acid metal compounds. In addition, there are aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and metal salts thereof, anhydrides, esters, phenol derivatives such as bisphenol, etc., and any of these conventionally known charge control agents (polarity control agents). ) Can also be used alone or in combination.
The content of these charge control agents is 0.1% by mass to 10% by mass, preferably 1% by mass to 5% by mass with respect to the binder resin of the toner.

<External additive>
In the present invention, it is preferable to use at least two kinds of external additives. Here, the different types mean that the primary particles in the external additive have different number average particle diameters or different materials. Those having a large particle size act as a spacer for suppressing contact between the toner and the member, and those having a small particle size impart fluidity to the toner. The larger the particle size of the external additive, the easier it is to release from the toner. The fine particles used as the external additive may be inorganic fine particles or organic fine particles.
The content of the external additive contained in the toner is a total value of a plurality of types of external additives, and is preferably 0.5% by mass to 3.5% by mass with respect to the base particles.
Further, the number average particle diameter of the external additive is more preferably 0.01 μm to 0.6 μm, and further preferably 0.05 μm to 0.4 μm.

<< Inorganic fine particles >>
The inorganic fine particles are not particularly limited and can be appropriately selected according to the purpose. For example, silica, alumina, titanium oxide (titania), barium titanate, magnesium titanate, calcium titanate, strontium titanate, Fluorine compound, iron oxide, copper oxide, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, Examples thereof include barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.

<< Organic fine particles >>
Examples of the organic fine particles include polymers of styrene such as polystyrene, poly p-chlorostyrene, and polyvinyl toluene, and substituted products thereof; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene. Copolymer, Styrene-vinylnaphthalene copolymer, Styrene-methyl acrylate copolymer, Styrene-ethyl acrylate copolymer, Styrene-butyl acrylate copolymer, Styrene-octyl acrylate copolymer, Styrene- Methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer Polymer, styrene-butadiene Styrene copolymers such as polymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate , Polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic carbonization Examples thereof include hydrogen resins, aromatic petroleum resins, chlorinated paraffins and paraffin waxes, which can be used alone or in combination.

Among these, it is preferable that the external additive contains at least one of silica, titania, alumina, a fluorine compound, and resin fine particles because good fluidity is obtained.
Examples of the fluorine compound include PTFE particles. Although it does not specifically limit as said PTFE particle, It is preferable that it is a low molecular type PTFE particle. Examples of commercially available PTFE particles include “KTL-500F” (manufactured by Kitamura, average particle size 0.5 μm), “Lublon L2” (manufactured by Daikin Industries, average particle size 300 nm), “Lublon L5, L5F”. (Daikin Kogyo Co., Ltd., average particle size 200 nm), TLP10F-1 (Mitsui / DuPont Fluorochemical Co., Ltd.), Fluon PTFE Lubricant-169J, L170J, L173J (Asahi Glass Co., Ltd.) and the like.

Examples of the silica fine particles include dry silica or fumed silica produced by vapor phase oxidation of silicon halide, wet silica produced from water glass, sol-gel silica produced by a sol-gel method, and the like. As the external additive, dry silica having less silanol groups on the surface and inside the silica fine particles and less Na ₂ O and SO ₃ ²⁻ is preferable. The dry silica may be composite fine particles of silica and another metal oxide produced by using a metal halogen compound such as aluminum chloride or titanium chloride together with a silicon halogen compound in the production process.

The surface of the external additive is preferably hydrophobized from the viewpoints of adjusting the charge amount of the toner, improving environmental stability, improving characteristics in a high humidity environment, and the like. This is because, if the external additive added to the toner absorbs moisture, the charge amount as the toner is lowered, the developing property and the transfer property are easily lowered, and the durability tends to be lowered.
Examples of the method for hydrophobizing the external additive include a method of chemically treating with an organosilicon compound that reacts or physically adsorbs with fine particles. In the present invention, inorganic fine particles that have been subjected to a hydrophobic treatment or not subjected to a hydrophobic treatment may be treated with a silicone oil.
Examples of the hydrophobizing agent to be surface-treated include unmodified silicone varnish, various modified silicone varnishes, unmodified silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organosilicon compounds, or organotitanium. Compounds. These treatment agents may be used alone or in combination.

A preferred example of the treatment of silica fine particles preferably used in the toner of the present invention will be described.
In the present invention, the silica fine particles are preferably silica fine particles obtained by treating the raw silica fine particles with silicone oil and then treating with the silane or silazane compound. By doing so, transferability, charging stability in a high temperature and high humidity environment, and fluidity after high temperature storage can be achieved at a higher level.
The silica fine particles are more preferably those obtained by crushing the raw silica fine particles after treating them with silicone oil. By performing the crushing treatment, the fluidity of the toner is further enhanced.

Furthermore, in the present invention, the silica fine particle is preferably 0.50% by mass or less, and 0.10% by mass or less, in the silica fine particle surface-treated with silicone oil, using hexane. More preferably. In this case, reduction of free oil in high-temperature storage can be expected, fluidity after high-temperature storage is good, and solid image followability is good.
The amount of the extracted silicone oil can be appropriately controlled according to the amount of treatment and the treatment temperature when the raw silica fine particles are treated with the silicone oil.

Furthermore, in the present invention, the hydrophobicity of the silica fine particles is preferably 95% or more and 100% or less, and more preferably 97% or more and 100% or less. When the hydrophobization rate of the silica fine particles is 95% or more, the charging stability during storage in a high temperature and high humidity environment is further improved. The hydrophobization rate of the silica fine particles can be controlled by the treatment amount and treatment conditions of the silane or silazane compound.
As the silicone oil used for the treatment of the silica fine particles of the present invention, a known silicone oil can be used without particular limitation, but straight silicone is particularly preferable.
More specifically, for example, dimethyl silicone oil, alkyl-modified silicone oil, α-methylstyrene-modified silicone oil, fluorine-modified silicone oil, or methylhydrogen silicone oil can be used.
The method for treating the silicone oil may be, for example, by directly mixing silica fine particles and silicone oil using a mixer such as a Henschel mixer, or by stirring while spraying the silicone oil on the raw silica fine particles. . Alternatively, it may be prepared by dissolving or dispersing silicone oil in an appropriate solvent (preferably adjusted to pH 4 with an organic acid or the like), mixing with the raw silica fine particles, and then removing the solvent. In addition, put the silica fine particles into the reaction vessel, add alcohol water while stirring under a nitrogen atmosphere, introduce a silicone oil treatment liquid into the reaction vessel to perform surface treatment, and then heat and stir to remove the solvent. You may take the method to do.

As the silane or silazane compound used for the treatment of the silica fine particles of the present invention, a known silane or silazane compound can be used without particular limitation.
Specifically, hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchloro. Silane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilyl mercaptan, trimethylsilyl mercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, or diphenyl Examples include diethoxysilane. Among these, hexamethyldisilazane is preferably used from the viewpoint of processing uniformity and coupling bond reliability. Silane compounds or silazane compounds can be used alone or in combination of two or more.

The treatment with at least one of the silane or silazane compound necessary for obtaining the silica fine particles of the present invention is a dry treatment in which the vaporized silane or silazane compound is reacted with the raw silica fine particles made into a cloud by stirring, or the raw material It can be processed by a generally known method such as a wet method in which silica fine particles are dispersed in a solvent and a silane or silazane compound is dropped.
In this invention, when processing with a silane compound or a silazane compound, it is good to use 1 mass part or more and 50 mass parts or less of a silane compound or a silazane compound with respect to 100 mass parts of original silica fine particles.
In addition, it can replace with a silica fine particle and can perform a hydrophobization process by the method similar to the above-mentioned method.

  The number average particle size of the external additive is preferably 1/5 or less, more preferably 1/10 or less, of the number average particle size of the base particles.

  In the present invention, it is preferable to add a plurality of types of external additives. In addition to the external additive having a number average particle diameter of 50 nm to 200 nm, an external additive having a number average particle diameter of 2 nm to 30 nm is also added. It is preferable to add an external additive of 2 nm to 20 nm. Those having a large particle size act as a spacer for suppressing contact between the toner and the member, and those having a small particle size impart fluidity to the toner. The number average particle size of the external additive refers to the average primary particle size, not the aggregated particle size.

An external additive having a number average particle diameter of 2 nm to 30 nm is preferable because it can be easily dispersed and fixed in the toner, is effective for coating the toner surface, and easily imparts fluidity to the toner. If the number average particle diameter is 2 nm or more, the fluidity is good, and if the number average particle diameter is 30 nm or less, the problem that the fluidity function is not sufficiently exhibited by adhering to the toner surface and reducing the contact area is effective Can be prevented.
On the other hand, embedding of the external additive into the toner base particles is likely to occur over time due to stress in the development process, increasing the non-electrostatic adhesion of the toner particles and deteriorating filming on the photoreceptor. Likely to happen. Further, since the frictional force between the toners tends to decrease, toner scattering and toner packing (pressurization, standing, etc.) tend to occur.
Therefore, by appropriately using together with an external additive of 50 nm to 200 nm, embedding of the small particle size external additive can be eased, and further, the toner transferability is improved by reducing the contact point and area with the member due to the spacer effect. And adjustment to increase the frictional force between powders (fluidity is lowered) and adjustment to relax packing properties are possible, so it is preferable to use them together while adjusting as necessary.

-Particle size measurement of external additives-
In the present invention, the particle size of the external additive can be measured as follows. External additives were observed with a TEM (transmission electron microscope, H-9000NAR manufactured by Hitachi), 100 particles were selected at random, and the particle size was calculated with image processing software (Nicore Image Analyzer Luzex AP). The number average particle diameter is determined.

<Characteristics of toner and powder>
<< Average particle size of toner and powder >>
In the toner and powder of the present invention, the number average particle diameter is preferably 3.0 μm or more.
In order to obtain a high image quality excellent in fine line reproducibility and the like, the number volume average particle diameter is more preferably 4.0 μm to 10 μm.
When the thickness is 3.0 μm or more, the image quality can be maintained satisfactorily without impairing the cleaning performance in the development process and the transfer efficiency in the transfer process. If it is 10 μm or less, the fine line reproducibility of the image can be kept good.

-Number average particle size of toner and powder-
The number volume average particle diameter of the toner and powder can be measured by various methods. For example, Coulter Multisizer III manufactured by Coulter Electronics, USA can be used.

<< Average circularity >>
In the toner or powder of the present invention, the average circularity of particles of 3.0 μm or more is preferably 0.910 to 0.975 from the following viewpoints.
From the viewpoint of handling the powder that comes into contact with the member, if the shape is too irregular, the variation in the contact point and the contact area will increase, resulting in a larger variation in the movement of the powder and an increase in the selection of particles, thereby hindering uniformity. It is easy to be moved and obstructs movement when packed. If it is too close to a sphere, the fluidity will be too high and it will be difficult to control the powder handling due to the flushing phenomenon, etc., the contact area will increase due to the relationship with the member roughness, and the toner will easily roll in the device. As a result, poor cleaning is likely to occur.

-Average circularity-
The average circularity can be measured by a flow type particle image analyzer FPIA-3000 (manufactured by Toa Medical Electronics Co., Ltd.). As a specific measurement method, a surfactant, preferably alkylbenzene sulfonate, is added in an amount of 0.1 mL to 0.5 mL as a dispersant in 100 mL to 150 mL of water from which impure solids have been removed in advance, and a measurement sample is further added. About 0.1 to 0.5 g. The suspension in which the sample is dispersed is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the concentration and dispersion of the toner are adjusted by the above apparatus with the dispersion concentration being 3,000 / μL to 10,000 / μL. Obtained by measuring.
The average circularity of particles of 3.0 μm or more is limited to the particle diameter in the analysis condition setting after measurement; 3.033 ≦ equivalent circle diameter (number basis) <400
It shows the average circularity obtained in.

<< Ru staining >>
When the toner or the powder is observed through a cross section of the toner by Ru dyeing, the toner or the powder has a shell structure having a different composition due to a contrast difference, and the average thickness of the shell structure is the toner or the powder. The diameter is preferably 1/60 to 1/10 of the diameter of the powder.
For example, when Ru dyeing is performed on a toner having a diameter of 6 μm, shell layers having different contrasts are observed on the surface with an average thickness of 100 nm to 600 nm.

Specifically, the average thickness of the shell structure can be measured as follows.
After the toner is embedded in an epoxy resin and cured, the cross section is cut out with a knife, and an ultrathin section of toner having a thickness of 80 nm is prepared using an ultramicrotome ULTRACUT UCT (manufactured by Leica). Next, the ultrathin section is gas-exposed with ruthenium tetroxide for 5 minutes to distinguish and stain the shell and the core. Further, using a TEM (transmission electron microscope) H7000 (manufactured by Hitachi High-Tech), an ultrathin section of the toner is observed at an acceleration voltage of 100 kV, and the thickness of the shell is measured. At this time, the thickness of the shell of the toner 10 particles is measured, and the average value is calculated.

<Method for producing toner and powder>
The toner and powder of the present invention can be obtained by externally adding the external additive to the base particles.
The base particles can be obtained by various production methods such as a pulverization method and a polymerization method (suspension polymerization, emulsion polymerization, dispersion polymerization, emulsion aggregation, emulsion association, etc.).
The toner of the present invention is preferably a toner having a small particle size and a nearly spherical shape so as to output a high-quality and high-definition image. Therefore, the toner production method is preferably a suspension polymerization method, an emulsion polymerization method, a polymer suspension method, or the like, in which an oil phase is emulsified, suspended or aggregated in an aqueous medium to form toner base particles.

<< Suspension polymerization method >>
Disperse a colorant, a release agent, a charge control agent, etc. in an oil-soluble polymerization initiator or polymerizable monomer, and emulsify and disperse it in an aqueous medium containing a surfactant, other solid dispersant, etc. . At this time, the particle size of the release agent is controlled by conditions such as the stirring speed and temperature for dispersing the release agent. Then, after carrying out a polymerization reaction to form particles, a wet treatment for attaching inorganic fine particles to the surface of the base particles in the present invention may be performed. At that time, it is preferable to treat the toner particles from which excess surfactant and the like are removed by washing.
Examples of the polymerizable monomer include acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride, and other acids, acrylamide, methacrylamide, di Functional groups are introduced on the surface of toner particles by using a part of acetone acrylamide or these methylol compounds, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethyleneimine, acrylates and methacrylates with amino groups such as dimethylaminoethyl methacrylate. it can.
Further, by selecting a dispersant having an acid group or a basic group as a dispersant to be used, the dispersant can be adsorbed and left on the particle surface to introduce a functional group.

<< Emulsion polymerization aggregation method >>
A water-soluble polymerization initiator and a polymerizable monomer are emulsified in water using a surfactant, and a latex is synthesized by an ordinary emulsion polymerization technique. Separately, a dispersion in which a colorant, a release agent having a controlled particle size, a charge control agent, and the like are dispersed in an aqueous medium is prepared, and after mixing, the toner particles are aggregated and heat-fused to obtain base particles. . Thereafter, wet processing of the inorganic fine particles may be performed. A functional group can be introduced on the surface of the toner particles by using a latex similar to the monomer that can be used in the suspension polymerization method.

<< Polymer suspension method >>
The aqueous medium used in the present invention may be water alone, or a solvent miscible with water may be used in combination. Examples of the miscible solvent include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), and the like. In the oil phase of the toner composition, a binder, a prepolymer, a colorant such as a pigment, a release agent with a controlled particle size, a charge control agent, and the like are dissolved or dispersed in a volatile solvent.
An oil phase composed of a toner composition is dispersed in an aqueous medium in the presence of a surfactant, a solid dispersant and the like, and a prepolymer is reacted to form particles. Thereafter, wet processing of the inorganic fine particles may be performed.

<< Dry grinding method >>
As an example of the pulverization system, a step of mechanically dry-mixing raw materials including at least a binder resin, a colorant, a charge control agent and a release agent, a step of melt-kneading, a step of pulverizing, and a step of classifying A method for producing a toner having the above can be applied. Further, in order to improve the dispersibility of the colorant, the colorant may be mixed with other raw materials after the masterbatch treatment and processed to the next step.
The toner by the pulverization method is preferable because the peak ratio C / R can be controlled.
The mixing step for mechanical mixing may be performed under normal conditions using a normal mixer using rotating wings, and is not particularly limited. When the above mixing process is completed, the mixture is then charged into a kneader and melt-kneaded. As the melt kneader, a uniaxial or biaxial continuous kneader or a batch kneader using a roll mill can be used. Specific apparatuses for kneading the toner include batch type two rolls, a Banbury mixer and a continuous type twin screw extruder, for example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type 2 manufactured by Toshiba Machine Co., Ltd. Screw extruder, KCK twin screw extruder, Ikegai Iron Works PCM type twin screw extruder, Kurimoto Iron Works KEX type twin screw extruder, continuous single screw kneader, such as Bus -Kneader etc. are used suitably. The melt-kneaded product obtained as described above is cooled and then pulverized. For pulverization, for example, coarsely pulverized using a hammer mill, a funnel plex, etc. A machine can be used. The pulverization is desirably performed so that the number average particle diameter is 3 μm to 10 μm.
Further, the pulverized product is adjusted in particle size to 2.5 μm to 20 μm by a wind classifier or the like.
In the pulverization method, the thickness of the kneaded product is preferably 2.5 mm or more and more preferably 2.5 mm or more and 8 mm or less in the cooling step after melt-kneading the raw materials.

  Next, external additives are added to the base particles. By mixing and stirring the base particles and the external additive using a mixer, the external additive is coated on the base particle surface while being crushed.

(Developer)
The developer of the present invention contains at least the toner and, if necessary, other components such as a carrier as appropriate.
For this reason, it is excellent in transferability, chargeability, etc., and a high quality image can be formed stably. The developer may be a one-component developer or a two-component developer. However, when used in a high-speed printer or the like that supports an increase in information processing speed in recent years, the lifetime is shortened. A two-component developer is preferred because it improves.

<Career>
There is no restriction | limiting in particular as said carrier, What is necessary is just to select suitably according to the objective, For example, a magnetic carrier and a resin carrier are mentioned. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used. The content ratio of the carrier and the toner in the developer is preferably 1 part by mass to 10 parts by mass of the toner with respect to 100 parts by mass of the carrier.
The carrier preferably has a core material and a resin layer covering the core material.

(Toner storage unit)
The toner storage unit in the present invention refers to a unit in which toner is stored in a unit having a function of storing toner. Here, examples of the toner storage unit include a toner storage container, a developing device, and a process cartridge.
The toner container is a container that contains toner.
The developing device is a unit having a means for containing and developing toner.
The process cartridge is a cartridge in which at least an electrostatic latent image carrier (also referred to as an image carrier) and a developing unit are integrated, accommodates toner, and is detachable from the image forming apparatus. The process cartridge may further include at least one selected from a charging unit, an exposure unit, and a cleaning unit.
By mounting the toner storage unit of the present invention on an image forming apparatus to form an image, the toner storage unit is excellent in low temperature fixing property, paper discharge blocking resistance, and releasability, and can be stressed in a developing machine for a long time. Taking advantage of the characteristics of the toner that does not cause crushing, it is possible to form a high-quality, high-definition image having long-term image stability.

(Image forming apparatus and image forming method)
The image forming apparatus of the present invention includes at least an electrostatic latent image carrier, an electrostatic latent image forming unit, and a developing unit, and further includes other units as necessary.
The image forming method of the present invention includes at least an electrostatic latent image forming step and a developing step, and further includes other steps as necessary.
The image forming method can be preferably performed by the image forming apparatus, the electrostatic latent image forming step can be preferably performed by the electrostatic latent image forming unit, and the developing step can be performed by the developing unit. The other steps can be preferably performed by the other means.
More preferably, the image forming apparatus of the present invention is an electrostatic latent image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image carrier. The electrostatic latent image formed on the body is developed with toner to form a toner image, and a developing means including toner, and the toner image formed on the electrostatic latent image carrier are transferred to a recording medium Transfer means for transferring to the surface, and fixing means for fixing the toner image transferred to the surface of the recording medium.
In the image forming method of the present invention, more preferably, an electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier and the electrostatic latent image carrier formed on the electrostatic latent image carrier. A developing process for developing the electrostatic latent image with toner to form a toner image, a transfer process for transferring the toner image formed on the electrostatic latent image carrier onto the surface of the recording medium, and the recording A fixing step of fixing the toner image transferred onto the surface of the medium.
The toner is used in the developing unit and the developing step. Preferably, the toner image may be formed by using a developer containing the toner and further containing other components such as a carrier as necessary.

<Electrostatic latent image carrier>
The material, structure, and size of the electrostatic latent image carrier are not particularly limited and may be appropriately selected from known materials. Examples of the material include inorganic photoreceptors such as amorphous silicon and selenium. And organic photoreceptors such as polysilane and phthalopolymethine.

<Electrostatic latent image forming means>
The electrostatic latent image forming means is not particularly limited as long as it is a means for forming an electrostatic latent image on the electrostatic latent image carrier, and can be appropriately selected according to the purpose. Examples thereof include at least a charging member that charges the surface of the electrostatic latent image carrier and an exposure member that exposes the surface of the electrostatic latent image carrier imagewise.

<Developing means>
The developing unit is not particularly limited as long as it is a developing unit including toner that develops the electrostatic latent image formed on the electrostatic latent image carrier to form a visible image. Can be selected as appropriate.

<Other means>
Examples of the other means include a transfer means, a fixing means, a cleaning means, a static elimination means, a recycling means, and a control means.

Next, one mode for carrying out the method of forming an image by the image forming apparatus of the present invention will be described with reference to FIG.
FIG. 5 is a schematic configuration diagram of an example of the image forming apparatus. Around a photosensitive drum 110 (hereinafter referred to as a photosensitive member) 110 as an image carrier, a charging roller 120 as a charging device, an exposure device 130, a cleaning device 160 having a cleaning blade, a static elimination lamp 170 as a static elimination device, and development. An apparatus 140 and an intermediate transfer member 150 as an intermediate transfer member are provided. The intermediate transfer member 150 is suspended by a plurality of suspension rollers 151 and is configured to run endlessly in the direction of the arrow by a driving unit such as a motor (not shown). A part of the suspension roller 151 also serves as a transfer bias roller for supplying a transfer bias to the intermediate transfer member, and a predetermined transfer bias voltage is applied from a power source (not shown). A cleaning device 190 having a cleaning blade for the intermediate transfer member 150 is also provided. Further, a transfer roller 180 is provided as a transfer means for transferring the developed image onto the transfer sheet 1100 as the final transfer material, facing the intermediate transfer body 150. The transfer roller 180 is applied with a transfer bias by a power supply device (not shown). Supplied. Around the intermediate transfer member 150, a corona charger 152 as a charge applying unit is provided.

The developing device 140 includes a developing belt 141 as a developer carrying member, a black (hereinafter referred to as “Bk”) developing unit 145K, a yellow (hereinafter referred to as “Y”) developing unit 145Y, and a magenta (hereinafter referred to as “below”). M) developing unit 145M and cyan (hereinafter referred to as C) developing unit 145C. The developing belt 141 is stretched between a plurality of belt rollers, and is configured to run endlessly in a direction indicated by an arrow by a driving unit such as a motor (not shown). Move at almost the same speed.
Since the configuration of each developing unit is common, the following description will be made only for the Bk developing unit 45K, and the other developing units 145Y, 145M, and 145C will be described in the parts corresponding to those in the Bk developing unit 145K in the drawing. Y, M, and C are appended to the numbers given to those in the unit, and the description is omitted. The Bk developing unit 145K is disposed so as to immerse the developing tank 142K containing a high-viscosity, high-concentration liquid developer containing toner particles and a carrier liquid component, and the lower part in the liquid developer in the developing tank 142K. And a coating roller 144K that thins the developer pumped from the pumping roller 143K and applies it to the developing belt 141. The application roller 144K has conductivity, and a predetermined bias is applied from a power source (not shown).
In addition to the apparatus configuration as shown in FIG. 5, the apparatus configuration of the copying machine according to the present embodiment is an apparatus configuration in which development units 145 for each color are provided around the photoconductor 110 as shown in FIG. It may be.

Subsequently, the operation of the image forming apparatus according to the present embodiment will be described. In FIG. 5, the photosensitive member 110 is uniformly charged by the charging roller 120 while being driven to rotate in the direction of the arrow, and then the reflected light from the original is imaged and projected onto the photosensitive member 110 by the optical system (not shown) by the exposure device 130. An electrostatic latent image is formed. This electrostatic latent image is developed by the developing device 140 to form a toner image as a visible image. The developer layer on the developing belt 141 is peeled off from the developing belt 141 in a thin layer state by contact with the photoconductor in the developing region, and moves to a portion where a latent image is formed on the photoconductor 110. The toner image developed by the developing device 140 is transferred to the surface of the intermediate transfer member 150 at the contact portion (primary transfer region) between the photosensitive member 110 and the intermediate transfer member 150 moving at a constant speed (primary transfer). Transcription). When transferring three or four colors to be superimposed, this process is repeated for each color to form a color image on the intermediate transfer member 150.
A corona charger 152 for applying a charge to the superimposed toner image on the intermediate transfer member is provided downstream of the contact facing portion between the photosensitive member 110 and the intermediate transfer member 150 in the rotation direction of the intermediate transfer member 150, and It is installed at a position upstream of the contact facing portion between the intermediate transfer member 150 and the transfer paper 1100. The corona charger 152 gives the toner image a true charge having the same polarity as the charge polarity of the toner particles forming the toner image, and the charge is sufficient for good transfer to the transfer paper 1100. To the toner image. The toner image is charged by a corona charger 152 and then transferred to a transfer paper 1100 conveyed in the direction of an arrow from a paper supply unit (not shown) by a transfer bias from a transfer roller 180 (secondary transfer). . Thereafter, the transfer paper 1100 onto which the toner image has been transferred is separated from the photoreceptor 110 by a separation device (not shown), and after being subjected to a fixing process by a fixing device (not shown), is discharged from the device. On the other hand, the untransferred toner is collected and removed by the cleaning device 160 on the photosensitive member 110 after the transfer, and the residual charge is discharged by the discharging lamp 170 in preparation for the next charging. A color image is usually formed with four colored toners. On one color image, toner layers of 1 to 4 layers are formed. The toner layer passes through primary transfer (transfer from the photosensitive member to the intermediate transfer belt) and secondary transfer (transfer from the intermediate transfer belt to the sheet).

-Tandem type color image forming device-
The image forming apparatus according to the present invention can also be used as a tandem color image forming apparatus. An example of an embodiment of a tandem type color image forming apparatus will be described. As shown in FIG. 7, the tandem type electrophotographic apparatus includes a direct transfer system in which an image on each photoconductor 1 is sequentially transferred onto a sheet conveyed by a sheet conveying belt 3 by a transfer apparatus 2, and FIG. As shown in FIG. 4, the images on the respective photosensitive members 1 are once transferred sequentially to the intermediate transfer member 4 by the primary transfer device 2, and then the images on the intermediate transfer member 4 are collectively transferred to the sheet s by the secondary transfer device 5. There are indirect transfer systems that transfer. The secondary transfer device 5 is a transfer conveyance belt, but there is also a roller shape method.
Comparing the direct transfer type and the indirect transfer type, the former arranges the sheet feeding device 6 on the upstream side of the tandem image forming apparatus T on which the photoconductors 1 are arranged, and the fixing device 7 on the downstream side. There is a drawback in that the size increases in the sheet conveying direction. On the other hand, the latter can set the secondary transfer position relatively freely. The paper feeding device 6 and the fixing device 7 can be disposed so as to overlap the tandem type image forming apparatus T, and there is an advantage that downsizing is possible.
In the former, in order not to increase the size in the sheet conveying direction, the fixing device 7 is disposed close to the tandem type image forming apparatus T. For this reason, the fixing device 7 cannot be disposed with a sufficient margin that allows the sheet s to bend, and an impact when the leading edge of the sheet s enters the fixing device 7 (particularly with a thick sheet) or fixing. There is a drawback that the fixing device 7 tends to affect image formation on the upstream side due to the difference in speed between the sheet conveyance speed when passing through the apparatus 7 and the sheet conveyance speed by the transfer conveyance belt.

On the other hand, in the latter case, the fixing device 7 can be disposed with a sufficient margin that the sheet can be bent, so that the fixing device 7 can hardly affect the image formation.
In view of the above, recently, an indirect transfer type of tandem type electrophotographic apparatus has attracted attention.
In this type of color electrophotographic apparatus, as shown in FIG. 8, the transfer residual toner remaining on the photoreceptor 1 after the primary transfer is removed by the photoreceptor cleaning apparatus 8 to clean the surface of the photoreceptor 1. In preparation for another image formation. Further, the transfer residual toner remaining on the intermediate transfer body 4 after the secondary transfer is removed by the intermediate transfer body cleaning device 9 to clean the surface of the intermediate transfer body 4 to prepare for image formation again.

FIG. 9 shows an embodiment of the present invention, which is a tandem indirect transfer type electrophotographic apparatus. In the figure, reference numeral 100 is a copying apparatus main body, reference numeral 200 is a paper feed table on which the copying apparatus is placed, reference numeral 300 is a scanner mounted on the copying apparatus main body 100, and reference numeral 400 is an automatic document feeder (ADF) mounted thereon. ). The copying machine main body 100 is provided with an endless belt-shaped intermediate transfer member 10 at the center.
Then, as shown in FIG. 9, in the illustrated example, it is wound around three support rollers 14, 15, and 16 so that it can be rotated and conveyed clockwise in the figure.
In this illustrated example, an intermediate transfer body cleaning device 17 for removing residual toner remaining on the intermediate transfer body 10 after image transfer is provided on the left of the second support roller 15 among the three.
Further, among the three images, four images of yellow, cyan, magenta, and black are arranged on the intermediate transfer member 10 stretched between the first support roller 14 and the second support roller 15 along the conveyance direction. The tandem image forming apparatus 20 is configured by arranging the forming units 18 side by side.
An exposure device 21 is further provided on the tandem image forming apparatus 20 as shown in FIG. On the other hand, a secondary transfer device 22 is provided on the side opposite to the tandem image forming apparatus 20 with the intermediate transfer body 10 interposed therebetween. In the illustrated example, the secondary transfer device 22 is configured by spanning a secondary transfer belt 24, which is an endless belt, between two rollers 23, and is pressed against the third support roller 16 via the intermediate transfer body 10. The image on the intermediate transfer body 10 is transferred to a sheet.
A fixing device 25 for fixing the transfer image on the sheet is provided beside the secondary transfer device 22. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt.
The secondary transfer device 22 described above is also provided with a sheet transport function for transporting the image-transferred sheet to the fixing device 25. Of course, a transfer roller or a non-contact charger may be arranged as the secondary transfer device 22, and in such a case, it is difficult to provide this sheet conveying function together.
In the illustrated example, a sheet reversing device 28 for reversing the sheet so as to record images on both sides of the sheet is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20 described above. Is provided.

Now, when making a copy using this color electrophotographic apparatus, a document is set on the document table 30 of the automatic document feeder 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed and pressed by it.
When a start switch (not shown) is pressed, when a document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. Immediately drives the scanner 300 and travels through the first traveling body 33 and the second traveling body 34. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34, and is reflected by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.
When a start switch (not shown) is pressed, one of the support rollers 14, 15, and 16 is driven to rotate by a drive motor (not shown), and the other two support rollers are driven to rotate to convey the intermediate transfer member 10. To do. At the same time, the individual image forming means 18 rotates the photoconductor 40 to form black, yellow, magenta, and cyan monochrome images on each photoconductor 40. Then, along with the conveyance of the intermediate transfer member 10, the single color images are sequentially transferred to form a composite color image on the intermediate transfer member 10.

On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, and the sheet is fed out from one of the paper feed cassettes 44 provided in multiple stages in the paper bank 43, and the separation roller 45. Are separated one by one into the paper feed path 46, transported by the transport roller 47, guided to the paper feed path 48 in the copying apparatus main body 100, and abutted against the registration roller 49 and stopped.
Alternatively, the sheet feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped.
Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer member 10, the sheet is fed between the intermediate transfer member 10 and the secondary transfer device 22, and transferred by the secondary transfer device 22. A color image is recorded on the sheet.
The image-transferred sheet is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the switching roller 55 is used to switch the discharge roller. The paper is discharged at 56 and stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.
On the other hand, the intermediate transfer body 10 after the image transfer is removed by the intermediate transfer body cleaning device 17 to remove residual toner remaining on the intermediate transfer body 10 after the image transfer, so that the tandem image forming apparatus 20 can prepare for another image formation.
Here, the registration roller 49 is generally used while being grounded, but it is also possible to apply a bias for removing paper dust from the sheet.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples. “Part” represents “part by mass” unless otherwise specified. “%” Represents “% by mass” unless otherwise specified.

(Production Example 1)
<Manufacture of toner base particles 1>
<< Production of First Amorphous Resin (Resin H1) >>
As a vinyl monomer, 580 g of styrene, 115 g of butyl acrylate, 33 g of acrylic acid, and 30 g of dicumyl peroxide as a polymerization initiator were placed in a dropping funnel. Among polyester monomers, as polyol, 1090 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.2) -2,2-bis (4 -Hydroxyphenyl) propane 400 g, isododecenyl succinic anhydride 230 g, terephthalic acid 330 g, 1,2,4-benzenetricarboxylic anhydride 180 g and dibutyltin oxide 7 g as esterification catalyst, thermometer, stainless steel stirrer, falling condenser and nitrogen Place in a 5 liter four-necked flask equipped with an inlet tube and stir at a temperature of 175 ° C. in a mantle heater under a nitrogen atmosphere, and mix the mixture of vinyl monomer resin and polymerization initiator from the dropping funnel over an hour. And dripped. The addition polymerization reaction was aged for 2 hours while maintaining the temperature at 175 ° C., and then the temperature was raised to 230 ° C. to perform the condensation polymerization reaction. The degree of polymerization was tracked by the softening point measured using a constant load extrusion capillary rheometer, and when the desired softening point was reached, the reaction was terminated to obtain Resin H1. The resin softening point was 128 ° C.

<< Production of Second Amorphous Resin (Resin L1) >>
As a polyol, 2260 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 820 g of terephthalic acid, 180 g of 1,2,4-benzenetricarboxylic anhydride, and dibutyltin oxide 0 as an esterification catalyst .6 g was put into a 5 liter four-necked flask equipped with a thermometer, a stainless steel stirrer, a flow-down condenser and a nitrogen introduction tube, and the temperature was raised to 230 ° C. in a nitrogen atmosphere in a mantle heater to conduct the condensation polymerization reaction It was. The degree of polymerization was monitored by the softening point measured using a constant load extrusion capillary rheometer, and when the desired softening point was reached, the reaction was terminated to obtain Resin L1. The resin softening point was 110 ° C.

<Crushed toner production example 1>
Resin H 1:30 parts, Resin H 2 70 parts, Colorant: Carbon Black (Cabot Corporation, Regal 400R) 6.8 parts, Mold Release Agent: Carnauba Wax (melting point: 81 ° C.) 4.0 parts, and charge 1.2 parts of the control agent “Bontron E-84” (manufactured by Orient Chemical Co., Ltd.) is mixed at 1200 rpm using a Henschel mixer 20B (manufactured by Mitsui Miike Chemical Co., Ltd.), and the resulting mixture is a continuous kneader. Bus co-kneader type MDK45 (manufactured by Buss) [feed amount: 10 kg / hr, screw rotation speed: 80 rpm, screw temperature: 40 ° C., set temperature (Z1 temperature: 100 ° C., Z2, 3 temperature: 80 ° C.) The kneaded product was obtained by kneading.
Next, the obtained kneaded product was cooled in the air and then coarsely pulverized with a Rotoplex (manufactured by Albaine) to obtain a coarsely pulverized product having a volume-median particle size (D50v) of 800 μm.
Further, toner base particles 1 having a volume average particle diameter of 7.5 μm and an average circularity of 0.926 were obtained using an IDS-2 type pulverizer (manufactured by Nippon Pneumatic Co., Ltd.) and an elbow jet classifier.
The Tg of toner base particles 1 was measured and found to be 61.5 ° C.

(Production Example 2)
<Manufacture of toner base particles 2>
<< Preparation of polyester resin dispersion 1 >>
・ 57 parts of terephthalic acid ・ 134 parts of fumaric acid ・ 38 parts of bisphenol A ethylene oxide adduct 339 parts of bisphenol A propylene oxide adduct The above monomer was charged into the flask, and the temperature was raised to 210 ° C. over 1 hour. After confirming that the reaction system was stirred, 1 part of titanium tetraethoxide was added.
Further, while distilling off the generated water, it took 1 hour from the same temperature to increase the temperature to 230 ° C., and continued the dehydration condensation reaction at 230 ° C. for another 1 hour. An amorphous polyester resin 1 of 16000 was obtained.

  Next, the obtained amorphous polyester resin 1 was transferred in a molten state to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) at a rate of 120 g / min. In a separately prepared aqueous medium tank, 0.4% concentration dilute ammonia water obtained by diluting reagent ammonia water with ion-exchanged water is placed, and the above amorphous is heated at 105 ° C. with a heat exchanger at 0.1 L / min. The melt was transferred to Cavitron CD1010 at the same time as the molten polyester resin melt. Thereafter, the pH in the system was adjusted to 8.0 with a 0.5 mol / l sodium hydroxide aqueous solution and treated at 45 ° C. for 3 hours, then the pH was adjusted to 7.0 with a nitric acid aqueous solution and the solid content was adjusted. A polyester resin dispersion 1 comprising polyester resin fine particles having an average particle size of 180 nm and a solid content of 30% by mass was obtained.

<< Preparation of Colorant Particle Dispersion >>
45 parts of carbon black (Regal 330 Cabot), 5 parts of ionic surfactant Neogen R (Daiichi Kogyo Seiyaku) and 200 parts of ion-exchanged water are mixed and dissolved, and dispersed for 10 minutes with a homogenizer (IKA Ultra Tarrax). Then, a dispersion treatment was performed using an optimizer to obtain a colorant particle dispersion having a central particle size of 240 nm and a solid content of 21%.

<< Preparation of release agent dispersion >>
-Paraffin wax HNP9 (melting temperature 75 ° C: Nippon Seiki Co., Ltd.) 45 parts-Cationic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts-Ion-exchanged water 200 parts Then, after dispersion with IKA Ultra Turrax T50, dispersion treatment was performed with a pressure discharge type gorin homogenizer to obtain a release agent dispersion having a center diameter of 190 nm and a solid content of 20.0% by mass.

<< Production of Toner Particles >>
-Polyester resin dispersion 1; 280 parts-Colorant particle dispersion; 27 parts-Release agent dispersion: 30 parts The above components were mixed and dispersed in a round stainless steel flask using Ultra Turrax T50. Next, 5 parts of polyaluminum hydroxide (manufactured by Asada Chemical Co., Ltd., Paho2S) was added, and the dispersion operation was continued with an ultra turrax. The flask was heated to 50 ° C. with stirring in an oil bath for heating. After holding at 50 ° C. for 90 minutes, an additional 65.0 parts of resin dispersion 1 was added.
Thereafter, the pH of the system was adjusted to 8.6 with a 0.5 mol / l sodium hydroxide aqueous solution, and then the stainless steel flask was sealed, and heated to 80 ° C. while continuing to stir using a magnetic seal for 5 hours. Retained.
After completion of the reaction, the reaction mixture was cooled and then filtered, washed with ion exchange water, and solid-liquid separation was performed by Nutsche suction filtration. This was further redispersed in 1 L of ion exchanged water at 35 ° C., and stirred and washed 5 times at 250 rpm for 10 minutes, and then the electric conductivity of the filtrate was 4.5 μS / cmt. Solid-liquid separation was performed by Nutsche suction filtration, followed by vacuum drying for 12 hours to obtain toner base particles 2 having a volume average particle size of 6.0 μm and an average circularity of 0.960.
The Tg of toner base particles 1 was measured and found to be 59.3 ° C.
In addition, the average thickness of the shell layer was about 230 nm from the measurement result of the cross section SEM of the toner.

(Preparation Example 1)
<Preparation of silica 1>
A silica fine particle substrate (A1; AEROSIL 300, manufactured by Nippon Aerosil Co., Ltd., hydrophilic untreated product) having a primary particle number average particle diameter (D1) of 7 nm is charged into an autoclave equipped with a stirrer, and then fluidized by stirring. Then, the substrate 1 was heated to 200 ° C.
10 parts by weight of dimethyl silicone oil (viscosity = 50 cs) is sprayed on 100 parts by weight of the substrate 1 while stirring in the reaction vessel. After stirring for 30 minutes, the temperature is increased to 300 ° C. while stirring. And allowed to stir for an additional 2 hours. Then, it took out and crushed using the pin type crushing apparatus.
Next, the inside of the reactor was replaced with nitrogen gas, and the reactor was sealed. Further, 10 parts by mass of hexamethyldisilazane was sprayed on the inside of 100 parts by mass of the substrate 1 to perform the silane compound treatment. .
This reaction was continued for 60 minutes, and then the reaction was terminated.
After completion of the reaction, the autoclave is depressurized, washed with a nitrogen gas stream to remove excess hexamethyldisilazane and by-products, and then subjected to 1 pass crushing treatment with a pulverizer (manufactured by Hosokawa Micron) to obtain silica fine particles 1 It was.

(Preparation Example 2)
<Preparation of silica 2>
In Preparation Example 1, the silica fine particle substrate was changed to a silica fine particle substrate (A2; AEROSIL 200, manufactured by Nippon Aerosil Co., Ltd.) having a primary particle number average particle diameter (D1) of 12 nm. Silica 2 fine particles were obtained.

(Preparation Example 3)
<Preparation of silica 3>
In Preparation Example 1, the silica fine particle substrate was changed to a silica fine particle substrate (A3; AEROSIL 90, manufactured by Nippon Aerosil Co., Ltd.) having a primary particle number average particle diameter (D1) of 23 nm. Silica 3 fine particles were obtained.

(Preparation Example 4)
<Preparation of silica 5>
In Preparation Example 1, the silica fine particle substrate was changed to a silica fine particle substrate (A5; UFP-30 untreated product, manufactured by DENKA Corporation), which is spherical silica having a sharp distribution with a primary particle number average particle diameter (D1) of 98 nm. Except for the above, silica fine particles were obtained in the same manner as in Preparation Example 1.

(Preparation Example 5)
<Preparation of titania 1>
As a first treatment step, 10 parts of isobutyltrimethoxysilane are added to 100 parts of acicular rutile-type titanium oxide fine particles (MT-150 untreated product, manufactured by Teica) having a number average particle diameter of 15.0 nm of primary particles. It sprayed and the process by the silane compound was performed in the state which the titanium oxide microparticles fluidized. This reaction was continued for 60 minutes, and then the reaction was terminated.
As a second treatment step, 10 parts of dimethyl silicone oil was sprayed on the titanium oxide fine particles produced in the first treatment step, and stirring was continued for 30 minutes. Thereafter, the temperature was raised to 190 ° C. with stirring, and the mixture was further stirred for 3 hours, whereby dimethyl silicone oil was baked on the surface of the titanium oxide fine particles, and the reaction was completed. Thereafter, the pulverizer (manufactured by Hosokawa Micron Corporation) was repeatedly pulverized until the aggregates of the titanium oxide fine particles disappeared to obtain titanium oxide fine particles 1 (titania 1) having a primary particle number average particle diameter of 15 nm.

(Examples 1-12, 14-17, and Comparative Examples 1-12)
As shown in Table 1, the external additive was fixed to the toner base particles under the following pre-pulverization conditions and fixing conditions. Subsequently, as shown in Table 2, an external additive was added and an external addition process was performed to obtain toners 1 to 12 and 14 to 29.
When the particle size and circularity of the toner 1 were measured, there was no particular change in the particle size: 7.5 μm and the circularity of 0.925.

[Preliminary crushing conditions]
The pre-crushing conditions for pre-crushing each silica before mixing with the toner base particles are as follows.
100 g to 300 g of raw material silica was charged into a 20 L Q mixer, and pulverized for 1 min at a peripheral speed of 50 m / s.
The preliminary crushing is a pretreatment for eliminating the difference in the degree of aggregation in securing the history reset and uniformity due to the difference in storage conditions.
As the crushing, it is preferable that the collision energy is high to some extent, the peripheral speed is preferably 40 m / s or more, and practically 40 m / s to 60 m / s is preferable. Further, the present invention is not limited to the Q mixer, and a general Henschel mixer can be set with the same setting.

[Immobilization conditions]
After mixing the toner base particles and the external additive, the fixation of fixing the external additive to the toner base particles was performed under the following conditions.

<Immobilization condition No. 1 (Normal setting)>
To a 20 L Henschel mixer, 2 kg of toner base particles and an external additive in the amount shown in Table 1 are added, and water at 15 ° C. is used as jacket cooling water, and mixed at the peripheral speed and time shown in Table 1. The immobilization was performed.

<Immobilization condition No. 2>
Immobilization condition no. 1 except that the jacket cooling water was connected to a temperature controller and the temperature was changed to 30 ° C. Immobilization was carried out in the same manner as in 1.
The solidification condition 2 is intended to promote fixation with the aid of a temperature load by heating. If the temperature is too high at the time of fixation, the toner aggregates due to the influence of heat from the toner Tg and stirring. Preferably it is 40 degrees C or less, More preferably, it is 30 degreeC +/- 5 degreeC.

<Immobilization condition No. 3>
To a 20 L Henschel mixer, 2 kg of toner base particles and an external additive in the amount shown in Table 1 were added, and 15 ° C. water was used as jacket cooling water, and mixed for 1 min at a peripheral speed of 30 m / s.
Subsequently, surface modification by heat was performed under the following conditions using a surface modification apparatus: a surfing system (manufactured by Nippon Pneumatic Industry Co., Ltd.)
・ Dispersing nozzles: 4 (90 degree symmetrical arrangement)
・ Blowing angle: 30 degrees ・ Hot air flow rate = 4 m ³ / min
・ Injection air flow rate = 0.7m ³ / min
・ Blower air volume = 10 m ³ / min
・ Hot air temperature = 135 ℃
Feed amount (sample supply amount): 2 kg / h
・ Cold air temperature = 15 ℃
・ Cooling water temperature = 5 ℃
And fixed.

<Immobilization condition No. 4 (Wet treatment 2 of pulverized toner)>
Into a 20 L Henschel mixer, 2 kg of toner base particles and an external additive in the amount shown in Table 1 were added, 15 ° C. water was used as jacket cooling water, and premixed for 1 min at a peripheral speed of 40 m / s. A premixed toner was obtained.
Next, 900 parts of ion-exchanged water and 8 parts of a cationic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.) are placed in a container equipped with a stirrer and an ultrasonic homogenizer (US-150T) and gradually stirred. Premixed toner: 300 parts were added and ultrasonically dispersed at 200 μA for 5 minutes with an ultrasonic homogenizer. Then, transfer to a container equipped with a stirrer, temperature sensor, and water temperature control unit, gradually warm while stirring, confirm that the temperature rose to 45 ℃, adjust the pH to 8.5, The mixture was stirred for 4 hours while maintaining at 45 ° C, cooled to 25 ° C to 30 ° C, and filtered. It was thoroughly washed with ion exchange water.

<Immobilization condition No. 5 (Wet treatment 2 of pulverized toner)>
Immobilization condition no. 4, the container equipped with a stirrer and an ultrasonic homogenizer (US-150T) was changed to a TK type homomixer, and the conditions were fixed except that the treatment was performed for 10 minutes while adjusting the rotational speed to 3500 rpm and the temperature to 40 ° C. No. Immobilization was carried out in the same manner as in No. 4.

  In Tables 1 and 2, the addition amount of the external additive is the addition amount (parts by mass) with respect to 100 parts by mass of the toner base particles.

(Example 13)
Immobilization was performed as follows.
Heating to 80 ° C. while continuing stirring using the magnetic seal at the time of preparation of the toner base particles 2, holding for 4.5 hours, cooling to 55 ° C., and adding the following dispersion to 100 parts by weight of toner base particles On the other hand, the addition amount of the external additive was added so that silica 3 was 0.6 parts by mass, silica 5 was 1.0 parts by mass, and titania 1 was 0.5 parts by mass, and kept at 55 ° C. Stir for 2 h, cool to 25-30 ° C. and filter. It was thoroughly washed with ion-exchanged water and immobilized. Further, an external additive was added under the conditions shown in Table 2 to obtain “toner”.

<Adjustment of external additive dispersion>
Here, each of the dispersion of silica 3, the dispersion of silica 5, and the dispersion of titania 1 is placed in a container equipped with a stirrer and an ultrasonic homogenizer (US-150T).
・ Ion-exchanged water 500 parts ・ Cationic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.) 3 parts ・ External additive 100 parts,
And ultrasonically disperse with an ultrasonic homogenizer at 200 μA for 10 minutes, and then transferred to a container equipped with a TK mixer agitator, a temperature sensor, and a water temperature control unit, and treated at 12000 rpm for 10 minutes without deposits. Each thing was confirmed and it was set as each dispersion liquid.

<Measurement of number distribution D>
For the toner obtained above, the density a of the toner base particles on the carbon tape and the density b of the particles (powder particles B) detached from the toner base particles adhering to the mica by the following vacuum dispersion type image analysis method Was measured. In the present embodiment, the powder particle B refers to an external additive.
A carbon double-sided tape E3605 for SEM (manufactured by EM Japan) was attached to the surface of an aluminum pin stub (manufactured by EM Japan) having a diameter of 25 mm × 8 mm, and mica punched to 10 mm was affixed thereon.
This pin stub is installed in the disperser NEBULA 1 (Phenom-World), the toner is raised at the sample inlet of the disperser, the pressure in the disperser is reduced to 10 kPa, and the sample inlet is opened for about 0.1 second. Toner was introduced into the disperser. With the introduction of the toner sample, the pressure in the disperser increased to 20 kPa. After maintaining this state for 1 minute, the inside of the disperser was brought to normal pressure, and the pin stub was taken out. When normalizing the inside of the disperser, air was introduced into the disperser at a speed of about 10 kPa / 5 seconds.
The density (a and b) of the toner base particles on the carbon tape on the pin stub surface and the powder particles B on the mica were calculated by SEM observation with a desktop SEM proX PREMIUM (manufactured by PHENOM-WORLD), and particle metric software ( The particle size distribution was measured with PHENOM-WORLD.
In the toner base particle analysis, 10 sheets of 2,000 times are selected, and 10 sheets of 2,000 times are selected in the detached particle analysis, and 50 nm is set as a threshold in image analysis.
-X axis: Particle diameter of powder particle B-Y axis: Number of powder particles B per toner (piece / toner)
As shown in FIG. 1, the number distribution obtained by measuring the particle diameter of the powder particles B in a measurement range of 500 nm or less and determining the number of the powder particles B divided by a range of every 25 nm, as shown in FIG. Graphed.

<Evaluation>
<< Evaluation method >>
In this invention, it evaluated using the following evaluation machines.
Evaluation was carried out using an evaluation machine that tuned a part of a full color copier imagio MP C4503 manufactured by Ricoh Co., Ltd., which has a four-color non-magnetic two-component developing unit and a four-color photoreceptor. The printing speed was evaluated by high-speed printing (45 sheets / min / A4).
1) Evaluation of cleanability in a low temperature and low humidity environment In a temperature and humidity environment with a temperature of 10 ° C. and a relative humidity of 15%, after outputting 10,000 5% image area density charts, 5,000 1% image area density charts are output. Then, after outputting 10,000 sheets of 10% image area density chart, the transfer residual toner on the photoconductor passed through the cleaning process is transferred to a scotch tape (manufactured by Sumitomo 3M Co., Ltd.) and pasted on a blank sheet. I attached. The image density of the obtained tape was measured by X-Rite 938 (manufactured by X-Rite), and the difference from blank paper was calculated and evaluated according to the following evaluation criteria.
〔Evaluation criteria〕
◎: Difference from blank (blank) less than 0.005 ○: Difference from blank (blank) from 0.005 to less than 0.010 Δ: Difference from blank (blank) from 0.010 to less than 0.020 X: The difference from the blank (blank paper) is 0.020 or more. In addition, what is evaluated as Δ or more is a level having no practical problem in terms of cleaning properties.

2) Filming property in a low-temperature and low-humidity environment After printing 10,000 sheets of a 5% image area density chart in a temperature and humidity environment of a temperature of 10 ° C. and a relative humidity of 15%, a 1% image area density chart is printed by 5,000. Thereafter, the amount of adhering components adhering to the photoreceptor after outputting 10,000 sheets of 10% image area density chart was visually evaluated according to the following evaluation criteria.
〔Evaluation criteria〕
◎: Good with no adhesion ○: Slightly cloudy traces are observed △: Cloudy streaks can be confirmed ×: Many cloudy areas are observed Note that those evaluated as △ or more are practical in terms of filming properties There is no problem level.

The “external additive liberation number” in the above table refers to the external additive liberation number per toner.

Aspects of the present invention are as follows, for example.
<1> A toner containing base particles and an external additive attached to the base particles,
Adhesive spot made of carbon tape, the surface of which is placed so as to be orthogonal to the direction connecting the center of the decompression space and the center of the introduction port, by introducing the toner into the decompression space from the entrance. From the density a of the base particles A adhering to the adhesive portion and the density b of the following powder particles B adhering to the mica from one of the base particles A A toner that satisfies the following conditions 1 and 2 when the number distribution D of the particle diameters of the generated powder particles B is calculated.
Powder particles B: particles separated from the base particles Condition 1: When the number distribution D is plotted, the horizontal axis is a range of particle diameters every 25 nm and the vertical axis is the number of the powder particles B The number of the powder particles B has a maximum value in any of the ranges of 25 nm to 150 nm, 150 nm to 175 nm, and 175 nm to 200 nm.
Condition 2: In the number distribution D, the number of particles having a particle diameter of 125 nm or less is 30% or less.
<2> The toner according to <1>, wherein the external additive is at least one of silica, titania, alumina, a fluorine compound, and resin fine particles.
<3> A powder containing base particles and an external additive attached to the base particles,
The pressure-sensitive adhesive made of carbon tape, the powder being charged into the decompression space from the inlet and having a surface arranged perpendicular to the direction connecting the center of the decompression space and the center of the inlet. One of the base particles A from the density a of the base particles A adhering to the adhesive location and the density b of the following powder particles B adhering to the mica by colliding with the substrate surface having the location and mica The powder satisfying the following conditions 1 and 2 when calculating the number distribution D of the particle diameters of the powder particles B generated from the powder:
Powder particles B: particles separated from the base particles Condition 1: When the number distribution D is plotted, the horizontal axis is a range of particle diameters every 25 nm and the vertical axis is the number of the powder particles B The number of the powder particles B has a maximum value in any of the ranges of 25 nm to 150 nm, 150 nm to 175 nm, and 175 nm to 200 nm.
Condition 2: In the number distribution D, the number of particles having a particle diameter of 125 nm or less is 30% or less.
<4> A two-component developer comprising a carrier and the toner according to any one of <1> to <2>.
<5> A toner storage unit that stores the toner according to any one of <1> to <2>.
<6> an electrostatic latent image carrier, and electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier;
Developing means comprising toner for developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image;
Transfer means for transferring the toner image formed on the electrostatic latent image carrier onto the surface of a recording medium;
Fixing means for fixing the toner image transferred to the surface of the recording medium,
The toner is the toner according to any one of <1> to <2>.
<7> an electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier;
A developing step of developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image;
A transfer step of transferring a toner image formed on the electrostatic latent image carrier onto the surface of a recording medium;
Fixing the toner image transferred to the surface of the recording medium,
An image forming method, wherein the toner is the toner according to any one of <1> to <2>.

  According to the present invention, the above-described problems can be solved, and abnormal images due to filming due to external additives on the photoreceptor are generated even when used repeatedly over a long period of time particularly in a low temperature and low humidity environment. In addition, it is possible to provide a toner that is excellent in cleaning properties.

Japanese Patent No. 3129074 JP 2014-174341 A

Claims (7)

A toner containing base particles and an external additive attached to the base particles,
Adhesive spot made of carbon tape, the surface of which is placed so as to be orthogonal to the direction connecting the center of the decompression space and the center of the introduction port, by introducing the toner into the decompression space from the entrance. From the density a of the base particles A adhering to the adhesive portion and the density b of the following powder particles B adhering to the mica from one of the base particles A A toner that satisfies the following conditions 1 and 2 when the number distribution D of the particle diameters of the generated powder particles B is calculated.
Powder particles B: particles separated from the base particles Condition 1: When the number distribution D is plotted, the horizontal axis is a range of particle diameters every 25 nm and the vertical axis is the number of the powder particles B The number of the powder particles B has a maximum value in any of the ranges of 25 nm to 150 nm, 150 nm to 175 nm, and 175 nm to 200 nm.
Condition 2: In the number distribution D, the number of particles having a particle diameter of 125 nm or less is 30% or less.   The toner according to claim 1, wherein the external additive is at least one of silica, titania, alumina, a fluorine compound, and resin fine particles. A powder containing base particles and an external additive attached to the base particles,
The pressure-sensitive adhesive made of carbon tape, the powder being charged into the decompression space from the inlet and having a surface arranged perpendicular to the direction connecting the center of the decompression space and the center of the inlet. One of the base particles A from the density a of the base particles A adhering to the adhesive location and the density b of the following powder particles B adhering to the mica by colliding with the substrate surface having the location and mica The powder satisfying the following conditions 1 and 2 when calculating the number distribution D of the particle diameters of the powder particles B generated from the powder:
Powder particles B: particles separated from the base particles Condition 1: When the number distribution D is plotted, the horizontal axis is a range of particle diameters every 25 nm and the vertical axis is the number of the powder particles B The number of the powder particles B has a maximum value in any of the ranges of 25 nm to 150 nm, 150 nm to 175 nm, and 175 nm to 200 nm.
Condition 2: In the number distribution D, the number of particles having a particle diameter of 125 nm or less is 30% or less.   A two-component developer comprising a carrier and the toner according to claim 1.   A toner containing unit containing the toner according to claim 1. An electrostatic latent image carrier, and electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier;
Developing means comprising toner for developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image;
Transfer means for transferring the toner image formed on the electrostatic latent image carrier onto the surface of a recording medium;
Fixing means for fixing the toner image transferred to the surface of the recording medium,
The image forming apparatus according to claim 1, wherein the toner is the toner according to claim 1. An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier;
A developing step of developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image;
A transfer step of transferring a toner image formed on the electrostatic latent image carrier onto the surface of a recording medium;
Fixing the toner image transferred to the surface of the recording medium,
The image forming method according to claim 1, wherein the toner is the toner according to claim 1.