JP6107484B2 - Image forming apparatus and process cartridge - Google Patents

Description

  The present invention relates to an image forming apparatus and a process cartridge.

  A method for visualizing image information through an electrostatic charge image by electrophotography or the like is currently used in various fields. In electrophotography, image information is formed as an electrostatic charge image on the surface of an image carrier (photoreceptor) by charging and exposure processes, and a toner image is developed on the surface of the photoreceptor using a developer containing toner. The toner image is visualized as an image through a transfer process for transferring the toner image to a recording medium such as paper and a fixing process for fixing the toner image on the surface of the recording medium.

  For example, Patent Document 1 states that “as an external additive, 0.05 to 2.0 parts by weight of a hydrophobic silica A having a number average particle diameter of 5 to 20 nm and a number average of 100 parts by weight of toner base particles. 0.05 to 2.0 parts by weight of hydrophobic titania having a particle diameter of 5 to 40 nm, 1.0 to 5.0 parts by weight of hydrophobic silica B having a number average particle diameter of more than 20 nm and 70 nm or less 0.1 to 1.0 parts by weight of strontium titanate having an average particle size of 30 to 75 nm and 0.01 to 0.1 parts by weight of zinc stearate having a volume median particle size of 1.5 to 12 μm A two-component developer ”is disclosed.

JP 2010-44113 A

  An object of the present invention is to provide an image forming apparatus that suppresses the occurrence of white streaks in an image in a low-temperature and low-humidity environment and a high-temperature and high-humidity environment.

The above problem is solved by the following means.
The invention according to claim 1
An image carrier,
A charging means having a charging member of a contact charging method for charging the surface of the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
Toner particles having a volume average particle size of 3.0 μm or more and 9.0 μm or less, lubricant particles, abrasive particles, and silica having a number average particle size of 80 nm to 200 nm and a shape factor SF2 of 130 to 180 Developing means for containing an electrostatic charge image developer containing toner having an external additive containing particles and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer When,
Transfer means for transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
Cleaning means having a cleaning blade for cleaning the surface of the image carrier;
Fixing means for fixing the toner image transferred to the surface of the recording medium;
Equipped with a,
The mass ratio of the silica particles to the lubricant particles (the silica particles / the lubricant particles) is 5 or more and 200 or less,
The mass ratio of the silica particles to the abrasive particles (the silica particles / the abrasive particles) is 3 or more and 20 or less,
The mass ratio of the lubricant particles and said abrasive particles (the lubricant particles / the abrasive particles) 1/15 to 2 der Ru image forming apparatus.

The invention according to claim 2
The image forming apparatus according to claim 1, wherein a contact pressure of the contact charging method charging unit with respect to the image holding member is 2N or more and 10N or less.

The invention according to claim 3,

The image forming apparatus according to claim 1, wherein the lubricant particles are zinc stearate particles.

The invention according to claim 4
The image forming apparatus according to claim 1 , wherein the abrasive particles are strontium titanate particles.

The invention according to claim 5
An image carrier,
A charging means having a charging member of a contact charging method for charging the surface of the image carrier;
Toner particles having a volume average particle size of 3.0 μm or more and 9.0 μm or less, lubricant particles, abrasive particles, and silica having a number average particle size of 80 nm to 200 nm and a shape factor SF2 of 130 to 180 Development in which an electrostatic charge image developer containing toner having an external additive containing particles is contained, and the electrostatic charge image formed on the surface of the image carrier is developed as a toner image by the electrostatic charge image developer. Means,
Cleaning means having a cleaning blade for cleaning the surface of the image carrier;
With
The mass ratio of the silica particles to the lubricant particles (the silica particles / the lubricant particles) is 5 or more and 200 or less,
The mass ratio of the silica particles to the abrasive particles (the silica particles / the abrasive particles) is 3 or more and 20 or less,
The mass ratio of the lubricant particles to the abrasive particles (the lubricant particles / the abrasive particles) is 1/15 or more and 2 or less,
A process cartridge attached to and detached from the image forming apparatus.

  According to the first aspect of the present invention, in an image forming apparatus including a contact charging type charging unit and a cleaning unit having a cleaning blade, a lubricant particle or an abrasive particle is used together with the silica particle as an external additive of the toner. An image forming apparatus that suppresses the occurrence of white stripes in an image in a low temperature and low humidity environment and a high temperature and high humidity environment is provided.

  According to the second aspect of the present invention, in the image forming apparatus including the contact charging type charging unit and the cleaning unit having the cleaning blade, the silica particles and the lubricant particles or the abrasive particles are used together as the external additive of the toner. Image formation that suppresses the generation of white streaks in low-temperature and low-humidity environments and high-temperature and high-humidity environments even when the contact pressure of the charging means of the contact charging method with respect to the image carrier is within the above range compared to An apparatus is provided.

According to the first aspect of the present invention, there is provided an image forming apparatus that suppresses generation of white streaks in an image in a low temperature and low humidity environment and in a high temperature and high humidity environment as compared with a case where the mass ratio of each particle is outside the above range. Provided.

According to the third aspect of the present invention, in an image forming apparatus including a charging unit having a contact charging type charging member and a cleaning unit having a cleaning blade, lubricant particles or polishing particles are used together with the silica particles as an external additive of the toner. Compared to the case where no agent particles are used in combination, an image forming apparatus is provided that suppresses the generation of white streaks in a low-temperature, low-humidity environment and a high-temperature, high-humidity environment even when zinc stearate particles are applied as lubricant particles. The

According to the fourth aspect of the present invention, in an image forming apparatus comprising a charging unit having a contact charging type charging member and a cleaning unit having a cleaning blade, lubricant particles or polishing particles are used together with the silica particles as an external additive of the toner. Compared to the case where no agent particles are used in combination, an image forming apparatus is provided that suppresses the generation of white streaks in images in a low temperature and low humidity environment and in a high temperature and high humidity environment even when strontium titanate particles are applied as abrasive particles. The

According to the invention of claim 5 , in a process cartridge comprising a charging means having a contact charging type charging member and a cleaning means having a cleaning blade, a lubricant particle or an abrasive together with the silica particles as an external additive of toner. A process cartridge that suppresses the occurrence of white streaks in an image in a low-temperature and low-humidity environment and a high-temperature and high-humidity environment is provided as compared with a case where particles are not used together.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows an example of the process cartridge which concerns on this embodiment.

  Hereinafter, an embodiment which is an example of the present invention will be described in detail.

The image forming apparatus according to the present embodiment forms an electrostatic charge image on the surface of the image holding member, a charging unit having a contact charging method charging member that charges the surface of the image holding member, and the charged image holding member. An electrostatic charge image forming means, a developing means for containing an electrostatic charge image developer, and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer, and the image Transfer means for transferring the toner image formed on the surface of the holding member to the surface of the recording medium; Cleaning means having a cleaning blade for cleaning the surface of the image holding member; and Toner image transferred to the surface of the recording medium And fixing means for fixing.
The electrostatic charge image developer has toner particles having a volume average particle size of 3.0 μm or more and 9.0 μm or less, lubricant particles, abrasive particles, and number average particle size of 80 nm or more and 200 nm or less, and a shape factor SF2. And an external additive containing silica particles having a particle size of 130 or more and 180 or less.

  Here, if the toner includes large-diameter and irregularly shaped silica particles having the particle diameter and shape factor in the above ranges as external additives (hereinafter referred to as “deformed silica particles”), the irregularly shaped silica particles are embedded in the toner particle surface. In addition, since it is difficult for the deformed silica particles to migrate to the concave portions on the surface of the toner particles, the toner transfer maintenance property and heat storage property are improved.

  However, when externally added irregularly shaped silica particles having a particle size in the above range, the irregularly shaped silica particles are easily released from the toner particles in a low temperature and low humidity environment (for example, 10 ° C., 10% RH). In some cases, streaks are generated on the image at an early stage due to the silica particles slipping through the cleaning blade and the contact charger is contaminated. In addition, the surface of the image carrier may be coated with silica (hereinafter sometimes referred to as “silica filming”) by pressing with a cleaning blade or a contact charger. When silica filming partially occurs on the surface of the image carrier, the surface potential of the image carrier changes, and white streaks of the image may occur.

  Therefore, when the toner particles include lubricant particles together with irregular-shaped silica particles as external additives, the lubricant particles are crushed at the contact portion between the image carrier and the cleaning blade, and a lubricant film is formed on the surface of the image carrier. As a result, the stability of the cleaning blade is increased, and slipping of the irregular shaped silica particles from the cleaning blade is reduced even under a low temperature and low humidity environment, thereby suppressing the occurrence of white streaks.

  On the other hand, when the toner particles include lubricant particles together with irregular-shaped silica particles as external additives, the irregular-shaped silica particles released from the toner particles function as an abrasive, and lubrication by the lubricant particles on the surface of the image carrier. Appropriately scrapes the agent film to suppress the formation of an excessive lubricant film. This phenomenon of excessive formation of a lubricant film may be referred to as “lubricant filming”.

  However, when externally shaped irregularly shaped silica particles having a particle size in the above range are externally added, the irregularly shaped silica particles are hardly released from the surface of the toner particles under a high temperature and high humidity environment (for example, in an environment of 30 ° C. and 80% RH). The function as an agent becomes difficult to be exhibited. As a result, the contact charging type charging means is contaminated by the lubricant and streaks are generated. In addition, lubricant filming (formation of an excessive lubricant film) may occur on the surface of the image carrier. When lubricant filming partially occurs on the surface of the image carrier, the surface potential of the image carrier changes, and white streaks of the image may occur.

  Therefore, if abrasive particles are included together with irregular shaped silica particles and lubricant particles as external additives in the toner, even if the irregular shaped silica particles are hardly released from the surface of the toner particles in a high temperature and high humidity environment. The film of the lubricant is polished by the abrasive particles, and the lubricant filming is suppressed.

  As described above, in the image forming apparatus according to the present embodiment, in the image forming apparatus including the contact charging type charging unit and the cleaning unit having the cleaning blade, the image forming apparatus has a low temperature and low humidity environment (for example, 10 ° C., 10% RH) and a high temperature. The occurrence of white streaks in the image under a high humidity environment (for example, at 30 ° C. and 80% RH environment) is suppressed.

In particular, when externally added relatively small deformed silica particles having a number average particle size of 80 nm or more and 110 nm or less are added to toner particles having a volume average particle size of 3.0 μm or more and less than 5.0, the external additive is used in a high temperature and high humidity environment. Is easily buried and lubricant filming is likely to occur.
When toner particles having a volume average particle diameter of 5.0 μm or more and 9.0 μm or less are externally added with relatively large irregular silica particles having a number average particle diameter of 120 nm or more and 200 nm or less, the irregular silica particles are formed under a low temperature and low humidity environment. The toner particles are easily separated from the toner particles and silica filming is likely to occur. For this reason, the surface potential of the image carrier changes, and white streaks of the image are likely to occur. However, even in this case, in the image forming apparatus according to the present embodiment, the occurrence of white stripes in the image under both the low temperature and low humidity environment and the high temperature and high humidity environment is suppressed.

  Further, when the contact pressure of a charging means (for example, a charging roll) of a contact charging method with respect to the image carrier is 2N or more and 10N or less (preferably 3N or more and 7N or less), silica filming and lubricant on the surface of the image carrier The surface potential of the image carrier changes due to filming, and white streaks of the image are likely to occur. However, even when the contact charging method charging means is provided at the contact pressure, the image forming apparatus according to the present embodiment generates white streaks in the image under the low temperature and low humidity environment and the high temperature and high humidity environment. It is suppressed.

  Note that in the image forming apparatus according to the present embodiment, a charging step of charging the surface of the image holding member by a contact charging type charging unit, and an electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image holding member. And a developing step of developing the electrostatic image formed on the surface of the image carrier as a toner image by the electrostatic image developer according to the present embodiment, and the toner image formed on the surface of the image carrier as a recording medium An image forming method including a transfer step of transferring to the surface of the recording medium, a cleaning step of cleaning the surface of the image carrier with a cleaning blade, and a fixing step of fixing the toner image transferred to the surface of the recording medium is performed. .

The image forming apparatus according to the present embodiment is a direct transfer type apparatus that directly transfers a toner image formed on the surface of an image carrier to a recording medium; the toner image formed on the surface of the image carrier is transferred to an intermediate transfer member Intermediate transfer system device that primarily transfers the toner image transferred to the surface of the intermediate transfer body to the surface of the intermediate transfer body; then neutralizes the image on the surface of the image carrier after the toner image is transferred and before charging. A well-known image forming apparatus such as an apparatus provided with a neutralizing unit that performs neutralization by irradiating is applied.
In the case of an intermediate transfer type apparatus, the transfer means includes, for example, an intermediate transfer body on which a toner image is transferred to the surface, and a primary transfer that primarily transfers the toner image formed on the surface of the image holding body to the surface of the intermediate transfer body. And a secondary transfer unit that secondarily transfers the toner image transferred onto the surface of the intermediate transfer member onto the surface of the recording medium.

  In the image forming apparatus according to the present embodiment, for example, a part including a charging unit, a developing unit, and a cleaning unit may be a cartridge structure (process cartridge) that is detachable from the image forming apparatus.

  Hereinafter, an example of the image forming apparatus according to the present embodiment will be described, but the present invention is not limited thereto. The main parts shown in the figure will be described, and the description of the other parts will be omitted.

FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to the present embodiment.
The image forming apparatus shown in FIG. 1 is a first to first electrophotographic method that outputs yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. Fourth image forming units 10Y, 10M, 10C, and 10K (image forming means) are provided. These image forming units (hereinafter sometimes simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged in parallel at a predetermined distance from each other in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from the image forming apparatus.

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

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

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

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

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

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

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

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

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

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

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

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

  Next, the electrostatic charge image developer (hereinafter, the electrostatic charge image developer according to this embodiment) applied to the image forming apparatus according to this embodiment will be described in detail.

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

[toner]
The toner according to the exemplary embodiment includes toner particles and an external additive.

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

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

A polyester resin is suitable as the binder resin.
Examples of the polyester resin include known polyester resins.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  The volume average particle diameter (D50v) of the toner particles is 3.0 μm or more and 9.0 μm or less, but preferably 4 μm or more and 8 μm or less.

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

  The shape factor SF1 of the toner particles is preferably 110 or more and 150 or less, and more preferably 120 or more and 140 or less.

The shape factor SF1 is obtained by the following formula.
Formula: SF1 = (ML ² / A) × (π / 4) × 100
In the above formula, ML represents the absolute maximum length of the toner, and A represents the projected area of the toner.
Specifically, the shape factor SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and is calculated as follows. That is, by capturing an optical microscope image of particles dispersed on the surface of a slide glass into a Luzex image analyzer using a video camera, obtaining the maximum length and projected area of 100 particles, calculating by the above formula, and obtaining the average value can get.

(External additive)
As the external additive, deformed silica particles, lubricant particles, and abrasive particles are applied.

-Deformed silica particles-
The irregular shaped silica particles are silica particles having a number average particle diameter of 80 nm to 200 nm and a shape factor SF2 of 130 to 180.

The number average particle diameter of the irregular shaped silica particles is from 80 nm to 200 nm, preferably from 90 nm to 160 nm, and more preferably from 100 nm to 140 nm.
When the average particle size of the irregular shaped silica particles is 80 nm or more, the embedding in the toner particles is suppressed, and the function as an external additive (spacer function) is easily secured. On the other hand, when the average particle size of the irregular shaped silica particles is 200 nm or less, the toner particles are excessive from the toner particles in a low temperature and low humidity environment (for example, 10 ° C., 10% RH environment) and a normal temperature and normal humidity environment (for example, 25 ° C., 55% RH). The amount of external addition to the toner particles is maintained, and the function as an external additive (spacer function) is easily secured.

  The volume average particle diameter of the irregular-shaped silica particles is determined by observing 100 primary particles of irregular-shaped silica particles after externally adding (dispersing) the irregular-shaped silica particles to the toner particles with a SEM (Scanning Electron Microscope) apparatus. By analysis, the longest diameter and the shortest diameter of each particle are measured, and the sphere equivalent diameter is measured from the intermediate value. The 50% diameter (D50p) in the number-based cumulative frequency of the obtained equivalent sphere diameter is defined as the average particle diameter of the irregular shaped silica particles (that is, the number average particle diameter).

The shape factor SF2 of the irregular-shaped silica particles is 130 or more and 180 or less, preferably 135 or more and 170 or less, and more preferably 140 or more and 160 or less.
When the shape factor SF2 of the irregular-shaped silica particles is 130 or more, uneven distribution of the surface of the toner particles over time in the recesses is suppressed, and a function as an external additive (spacer function) is easily secured. On the other hand, when the shape factor SF2 of the irregular shaped silica particles is 180 or less, the irregular shaped silica particles are hardly lost even when a mechanical load is applied.

The shape factor SF2 of the irregular-shaped silica particles is determined by observing 100 primary particles of irregular-shaped silica particles after externally adding (dispersing) the irregular-shaped silica particles to the toner particles with a SEM (Scanning Electron Microscope) apparatus. Thus, SF2 is calculated by the following formula, and the average value is obtained.
Formula: Shape factor SF2 = “PM ² / (4 · A · π)” × 100
Here, in the formula, PM indicates the perimeter of the irregular shaped silica particle. A shows the projected area of deformed silica particles. π represents a circumference ratio.

As long as the irregular shaped silica particles satisfy the number average particle diameter and the shape factor SF2, silica, that is, particles containing SiO ₂ as a main component, may be crystalline or amorphous. The irregular shaped silica particles may be particles produced from a silicon compound such as water glass or alkoxysilane, or particles obtained by pulverizing quartz.
Specifically, the irregular-shaped silica particles include sol-gel silica particles, aqueous colloidal silica particles, alcoholic silica particles, famed silica particles obtained by a gas phase method, and fused silica particles. Among these, sol-gel silica particles are Good. The sol-gel silica particles as the deformed silica particles are obtained, for example, according to the method for producing silica particles described in JP 2012-006781 A.

  It is preferable that the surface of the irregular shaped silica particles is subjected to a hydrophobic treatment with a hydrophobic treatment agent. Examples of the hydrophobizing agent include known organosilicon compounds having an alkyl group (eg, methyl group, ethyl group, propyl group, butyl group). Specific examples include, for example, silazane compounds (eg, methyl trimethyl compound). Silane compounds such as methoxysilane, dimethyldimethoxysilane, trimethylchlorosilane, and trimethylmethoxysilane, hexamethyldisilazane, tetramethyldisilazane, and the like. The hydrophobizing agent may be used alone or in combination. Among these hydrophobizing agents, organosilicon compounds having a trimethyl group such as trimethylmethoxysilane and hexamethyldisilazane are suitable.

  The external addition amount of the external additive is, for example, preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.01% by mass or more and 4.5% by mass or less, based on the toner particles. More preferably, it is at least 4.0% by mass.

-Lubricant particles-
Examples of the lubricant particles include well-known solid lubricant particles. Specific examples include particles of fatty acid metal salts, fluororesins, polyolefins, and the like.

  Examples of the fatty acid metal salt particles include, for example, fatty acid metal salts such as zinc stearate, cadmium, barium, lead, iron, nickel, cobalt, copper, aluminum, magnesium, and other metal salts, dibasic lead stearate, Metal salts of zinc oleate, magnesium, iron, cobalt, copper, lead, calcium, metal salts of palmitic acid and aluminum, calcium, lead caprylate, lead caproate, zinc linoleate, cobalt linoleate, ricinoleic acid Examples thereof include particles of metal salts such as calcium, ricinoleic acid and zinc, cadmium, and mixtures thereof.

  Examples of the fluororesin particles include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and polyvinylidene fluoride. (PVDF), tetrafluoroethylene-ethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyvinyl fluoride (PVF), fluoroolefin-vinyl ether Examples thereof include particles of a polymer, a vinylidene fluoride-tetrafluoroethylene copolymer, a vinylidene fluoride-hexafluoropropylene copolymer, and the like.

  Examples of the polyolefin particles include particles of waxes such as paraffin wax, paraffin latex, and microcrystalline wax.

  Among these, as the lubricant particles, zinc stearate particles are preferable from the viewpoint of the function as a lubricant, availability, and cost.

The number average particle diameter of the lubricant particles is, for example, preferably 0.1 μm or more and 10 μm or less, preferably 0.3 μm or more and 6 μm or less, more preferably 4 μm or more and 6 μm from the viewpoint of exhibiting the function as a lubricant. It is as follows.
The number average particle diameter of the lubricant particles is measured by the same method as the number average particle diameter of the irregular shaped silica particles.

  The external addition amount of the lubricant particles is, for example, preferably 0.01% by mass or more and 0.20% by mass or less, more preferably 0.015% by mass or more and 0.18% by mass or less with respect to the toner particles. More preferably, it is 02 mass% or more and 0.15 mass% or less.

-Abrasive particles-
Examples of the abrasive include known abrasive particles. Specifically, for example, cerium oxide, strontium titanate, magnesium oxide, alumina, silicon carbide, zinc oxide, silica, titanium oxide, boron nitride, calcium pyrophosphate. , Inorganic particles such as zirconia, barium titanate, calcium titanate, calcium carbonate, strontium titanate and the like.
Note that the abrasive particles may be subjected to a hydrophobizing treatment on the surface with a hydrophobizing agent, similarly to the irregular shaped silica particles.

  Among these abrasive particles, strontium titanate particles are preferred from the standpoint of function as an abrasive, availability, and cost.

The number average particle diameter of the abrasive particles is preferably, for example, from 0.1 μm to 3 μm, and preferably from 0.3 μm to 1 μm from the viewpoint of exhibiting the function as an abrasive.
The number average particle size of the abrasive particles is measured by the same method as the number average particle size of the irregular shaped silica particles.

  The external addition amount of the abrasive particles is preferably, for example, from 0.10% by mass to 0.30% by mass with respect to the toner particles.

-Others-
The mass ratio of irregular-shaped silica particles to lubricant particles (irregular-shaped silica particles / lubricant particles) is 5 because it makes it easier to suppress the occurrence of white streaks in images under low-temperature and low-humidity environments and high-temperature and high-humidity environments. It is preferably 200 or more, preferably 10 or more and 150 or less, more preferably 15 or more and 100 or less.
The mass ratio of irregular-shaped silica particles to abrasive particles (irregular-shaped silica particles / abrasive particles) is 3 or more and 20 or less (preferably from the viewpoint of facilitating the generation of white streaks in an image in a high temperature and high humidity environment. Is from 5 to 18, more preferably from 7 to 16.
The mass ratio of the lubricant particles to the abrasive particles (lubricant particles / abrasive particles) is 1/15 or more and 2 or less from the viewpoint of more easily suppressing the occurrence of white streaks in the image in a high-temperature and high-humidity environment. (Preferably 2/15 or more and 3/2 or less, more preferably 3/15 or more and 1 or less.

  As the external additive, other well-known external additives other than irregular-shaped silica particles, lubricant particles and abrasive particles may be used in combination.

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

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

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

  The toner according to the exemplary embodiment is manufactured, for example, by adding an external additive to the obtained dry toner particles and mixing them. Mixing may be performed, for example, with a V blender, a Henschel mixer, a Ladyge mixer, or the like. Furthermore, if necessary, coarse toner particles may be removed using a vibration classifier, a wind classifier, or the like.

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

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

  Examples of the conductive particles include particles of metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

Examples of the coating resin and matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic acid copolymer. Examples thereof include a polymer, a straight silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polycarbonate, a phenol resin, and an epoxy resin.
Note that the coating resin and the matrix resin may contain other additives such as a conductive material.

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

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

  Hereinafter, although an Example and a comparative example are given and this embodiment is described in detail in detail, this embodiment is not limited to these Examples at all. The “part” means “part by mass” unless otherwise specified.

[Production of toner particles]
(Production of toner particles (ta1))
-Preparation of polyester resin dispersion-
・ Terephthalic acid 30mol%
・ Fumaric acid 70mol%
・ Bisphenol A ethylene oxide 2 mol adduct 20 mol%
-Bisphenol A propylene oxide 2 mol adduct 80 mol%
Charge the above monomer into a 5 liter flask equipped with a stirrer, nitrogen inlet tube, temperature sensor, and rectifying column, and increase the temperature to 190 ° C over 1 hour, confirming that the reaction system is being stirred. Then, 1.2 mol% of dibutyltin oxide was added.
Further, while distilling off the water produced, it took 6 hours from the same temperature to increase the temperature to 240 ° C., and continued the dehydration condensation reaction at 240 ° C. for another 3 hours. The acid value was 12.0 mg / KOH, and the weight average molecular weight. An amorphous polyester resin of 9700 was obtained.

Subsequently, this was transferred in a molten state to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) at a rate of 100 g / min.
Separately prepared aqueous medium tank is filled with 0.37 wt% diluted ammonia water diluted with ion-exchanged water with reagent-exchanged water, and heated at 120 ° C with a heat exchanger at a rate of 0.1 liter per minute. The amorphous polyester resin 1 melt was transferred to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.).
The Cavitron was operated under conditions of a rotor rotation speed of 60 Hz and a pressure of 5 kg / cm ² to obtain a resin dispersion composed of a polyester resin having an average particle size of 0.16 μm and a solid content of 30% by mass.

-Preparation of colorant dispersion-
・ Cyan pigment (copper phthalocyanine B15: 3: manufactured by Dainichi Seika Co., Ltd.) 45 parts ・ Ionic surfactant Neogen RK (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts ・ Ion-exchanged water 200 parts The above ingredients are mixed and dissolved, and homogenizer (IKA Ultra Turrax) was dispersed for 10 minutes to obtain a colorant dispersion having a center particle size of 168 nm and a solid content of 22.0% by mass.

-Preparation of release agent dispersion-
・ Paraffin wax HNP9 (melting temperature 75 ° C .: manufactured by Nippon Seiki Co., Ltd.) 45 parts ・ Cationic surfactant Neogen RK (produced by 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 200 nm and a solid content of 20.0% by mass.

-Production of toner particles-
-Polyester resin dispersion 278.9 parts-Colorant dispersion 27.3 parts-Release agent dispersion 35 parts

The above components were mixed and dispersed with Ultra Turrax T50 in a round stainless steel flask. Next, 0.20 part of polyaluminum chloride was added thereto, and the dispersion operation was continued with an ultra turrax. The flask was heated to 48 ° C. with stirring in an oil bath for heating. After holding at 48 ° C. for 60 minutes, 70.0 parts of the resin dispersion was added thereto.
Thereafter, the pH of the system was adjusted to 9.0 with a 0.5 mol / l sodium hydroxide aqueous solution, and then the stainless steel flask was sealed and heated to 96 ° C. while continuing to stir using a magnetic seal for 5 hours. Retained.
After completion of the reaction, the mixture was cooled, filtered, washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 1 L of ion exchange water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes.
This was repeated five more times, and when the pH of the filtrate became 7.5 and the electric conductivity was 7.0 μS / cmt, solid-liquid separation was performed using No5A filter paper by Nutsche suction filtration. Vacuum drying was then continued for 12 hours.

  Through the above steps, toner particles (ta1) were obtained. The volume average particle diameter D50v of the toner particles (ta1) is 4.8 μm.

(Production of toner particles (tb1))
Toner particles having a volume average particle diameter D50v of 6.0 μm are the same as those of the toner particles (ta1) except that the temperature in the heating oil bath is changed from 48 ° C. to 50 ° C. in the production of the toner particles (ta1). (Tb1) was produced.

[Preparation of silica particles]
(Preparation of silica particles (SA1))
-Alkali catalyst solution preparation step [Preparation of alkali catalyst solution (1)]-
300 parts of methanol and 48.2 parts of 10% ammonia water were placed in a 3 L glass reaction vessel having a metal stirring bar, dropping nozzle (Teflon (registered trademark) micro tube pump) and thermometer, and stirred. By mixing, an alkali catalyst solution (1) was obtained. At this time, the ammonia catalyst amount of the alkali catalyst solution (1): NH ₃ amount (NH ₃ [mol] / (ammonia water + methanol) [L]) was 0.73 mol / L.

-Particle generation step [Preparation of sol-gel silica dispersion (1)]-
Next, the temperature of the alkali catalyst solution (1) was adjusted to 25 ° C., and the alkali catalyst solution (1) was replaced with nitrogen. Thereafter, while stirring the alkali catalyst solution (1), 450 parts of tetramethoxysilane (TMOS) was supplied at a feed rate of 5.67 parts / min, and 270 parts of aqueous ammonia having a catalyst (NH ₃ ) concentration of 4.44% was added. Dropping was simultaneously started at a supply rate of 3.40 parts / min to obtain a sol-gel silica dispersion (sol-gel silica dispersion (1)).

-Hydrophobization of sol-gel silica-
Hydrophobic treatment was performed by adding 5.59 parts of trimethylsilane to 200 parts of sol-gel silica dispersion (1) (solid content: 13.985%). Then, the hydrophobic sol-gel silica (1) was produced | generated by heating at 65 degreeC using a hotplate and making it dry.
The obtained hydrophobic sol-gel silica (1) was used as silica particles (SA1).

(Preparation of silica particles (SA2) to (SA8))
According to Table 1, except that the conditions of the alkali catalyst solution preparation step and the particle generation step were changed, hydrophobic sol-gel silica was generated in the same manner as the silica particles (SA1), and these were converted into silica particles (SA2) to (SA8). ).

(Preparation of silica particles (SB1) to (SB7))
According to Table 1, except that the conditions of the alkali catalyst solution preparation step and the particle generation step were changed, hydrophobic sol-gel silica was generated in the same manner as the silica particles (SA1), and these were converted into silica particles (SB1) to (SB7). ).

[Production of toner]
(Production of toner (TA1))
The amount of silica particles (SA1) is 1.5% by mass (vs. toner particles), the amount of zinc stearate particles (number average particle size 6.0 μm) as lubricant particles is 0.10% by mass (vs. toner particles), Each particle was added to the toner particles (ta1) so that the amount of strontium titanate particles (number average particle size 0.4 μm) as abrasive particles was 0.15% by mass (vs. toner particles). After mixing for 15 minutes at a peripheral speed of 30 m / s using a mixer, coarse particles were removed using a sieve having an opening of 45 μm to prepare a toner (TA1).

(Production of Toners (TA2) to (TA24))
Toners (TA2) to (TA24) are the same as toner (TA1) except that the types of toner particles, the types and amounts of silica particles, and the amounts of lubricant particles and abrasive particles are changed according to Table 2. Was made.

(Production of Toners (TB1) to (TB19))
According to Table 3, the toner (TB1) to (TB19) are the same as the toner (TA1) except that the type of toner particles, the type and amount of silica particles, and the amounts of lubricant particles and abrasive particles are changed. Was made.

[Production of developer]
(Production of developer (DA1))
4 parts of toner (TA1) and 96 parts of carrier were stirred for 20 minutes at 40 rpm using a V-blender, and sieved with a sieve having an opening of 250 μm to prepare developer (DA1). However, the following carrier 1 was used as a carrier.

-Production of carrier 1-
Ferrite particles (average particle size: 50 μm): 100 parts Toluene: 14 parts Styrene-methyl methacrylate copolymer (component ratio: 90/10): 2 parts Carbon black (R330: manufactured by Cabot Corporation): 0. Part 2 First, the above components other than the ferrite particles are stirred with a stirrer for 10 minutes to prepare a dispersed coating solution. Next, the coating solution and ferrite particles are placed in a vacuum degassing kneader and stirred at 60 ° C. for 30 minutes. After that, the carrier 1 was produced by further depressurizing while heating and degassing and drying.

(Production of developers (DA2) to (DA24))
Developers (DA2) to (DA24) were produced in the same manner as the developer (DA1) except that the type of toner was changed according to Table 2.

(Production of developers (DB1) to (DB19))
Developers (DB1) to (DB19) were produced in the same manner as the developer (DA1) except that the type of toner was changed according to Table 3.

[Examples (A1) to (A20), Comparative Examples (A1) to (A4)]
Each developer shown in Table 2 was modified from an image forming apparatus “700 Digital Color Press” manufactured by Fuji Xerox Co., Ltd. (equipment equipped with a charging roll arranged at a contact pressure of 5 N and a cleaning blade for cleaning the photosensitive member) ) Developing device.
The following evaluation was performed using this image forming apparatus.

[Examples (B1) to (B18), Comparative Example (B1)]
Each developer shown in Table 3 was modified from an image forming apparatus “700 Digital Color Press” manufactured by Fuji Xerox Co., Ltd. (equipment equipped with a charging roll arranged with a contact pressure of 6 N and a cleaning device equipped with a cleaning blade) ) Developing device.
The following evaluation was performed using this image forming apparatus.

[Evaluation]
(Evaluation of lubricant filming)
With the image forming apparatus of each example, an image having an overall image density of 10% (an image having 90% and 0% image density in the process direction) in a high temperature and high humidity environment (30 ° C., 80% RH) is A4. After 10,000 sheets were output on paper, a halftone image was output on A4 paper, and the occurrence of white streaks in the image was visually observed to evaluate lubricant filming. The results are shown in Tables 2 to 3.
The evaluation criteria are as follows.
A: White stripes not generated B: White stripes generated

(Evaluation of silica filming)
The image forming apparatus of each example continuously outputs 10,000 half-tone images with an image density of 10% on A4 paper in a low-temperature and low-humidity environment (10 ° C., 10% RH). The image was output to A4 paper, and the occurrence of white streaks in the image was visually observed to evaluate silica filming.
The evaluation criteria are as follows.
A: White stripes not generated B: White stripes generated

(Evaluation of charging roll dirt)
In a high-temperature and high-humidity environment (30 ° C., 80% RH), an image with a total image density of 20% (images with 90% and 0% image density in the process direction) was output continuously on A4 paper. Thereafter, the photoconductor was newly replaced, and the potential difference between 90% of the image area and 0% of the non-image area was measured to evaluate the charging roll stain.
The evaluation criteria are as follows. A is no problem, B is minor and has no problem in practical use, and C is problematic.
A: Potential difference of less than 5 V B: Potential difference of less than 10 V C: Potential difference of 10 V or more

(Evaluation of transfer maintenance)
The image forming apparatus of each example continuously outputs 10,000 half-tone images with an image density of 1% on A4 paper, and then the image density of the first and 10,000th sheets is set to X-Rite 404 (manufactured by X-Rite). ) And measured 5 points each to obtain an average value. By calculating the ratio (%) of the average value of the image density of 10,000 sheets to the average value of the image density of the single side. The transfer maintenance was evaluated.

(Ghost evaluation)
After outputting 10 images in which the image density in the process direction exceeds 90% and the image in which the image density in the process direction is 0%, 10 half-tone images are output, the process direction image density is 90%. A ghost (a phenomenon in which a density change occurs due to the history of the previous image forming cycle) was evaluated based on the brightness difference when the brightness of a 30% halftone image corresponding to a place where the image density in the process direction was 0% was measured.
The evaluation criteria are as follows.
A: Lightness difference less than 0.5 B: Lightness difference less than 1 C: Lightness difference of 1 or more

(Evaluation of photoconductor scratches)
Under the conditions of low temperature and low humidity (10 ° C., 10% RH) and high temperature and high humidity (30 ° C., 80% RH), 100,000 images were flown at a density of 5%, and a total of 200,000 images were flowed. The surface roughness at the time was confirmed. The 10-point average roughness (Rz) was measured with a surface roughness meter (Surfcom 1400A manufactured by Tokyo Seimitsu Co., Ltd.) to evaluate the photoconductor scratches.
The evaluation criteria are as follows.
A: Rz is less than 1.5 μm B: Rz is 1.5 or more and less than 2.5 C: Rz is 2.5 or more

  Tables 1 to 3 below list the details of each example, the evaluation results, and the characteristics of the silica particles measured by the method described above.

  From the above results, in this example in which irregular-shaped silica particles, lubricant particles, and abrasive particles were applied as external additives for the toner, compared to Comparative Examples A2 and A4 in which no lubricant particles or abrasive particles were applied, the charging roll stains , Transferability maintenance, ghosting, photoconductor scratches are evaluated well, and silica filming and lubricant filming are evaluated well, that is, white streaks of images under low temperature and low humidity environment and high temperature and high humidity environment. It turns out that generation | occurrence | production of is suppressed.

1Y, 1M, 1C, 1K, photoconductor (an example of an image carrier)
2Y, 2M, 2C, 2K, charging roll (an example of charging means)
3. Exposure device (an example of electrostatic charge image forming means)
3Y, 3M, 3C, 3K Laser beams 4Y, 4M, 4C, 4K Developing device (an example of developing means)
5Y, 5M, 5C, 5K primary transfer roll (an example of primary transfer means)
6Y, 6M, 6C, 6K Photoconductor cleaning device (an example of cleaning means)
6Y-1, 6M-1, 6C-1, 6K-1 Cleaning blades 8Y, 8M, 8C, 8K Toner cartridges 10Y, 10M, 10C, 10K Image forming unit 20 Intermediate transfer belt (an example of an intermediate transfer member)
22 Drive roll 24 Support roll 26 Secondary transfer roll (an example of secondary transfer means)
30 Intermediate transfer member cleaning device 107 Photosensitive member (an example of an image holding member)
108 Charging roll (an example of charging means)
109 Exposure apparatus (an example of electrostatic charge image forming means)
111 Developing device (an example of developing means)
112 Transfer device (an example of transfer means)
113 photoconductor cleaning device (an example of cleaning means)
113-1 clean blade 115 fixing device (an example of fixing means)
116 Mounting rail 117 Housing 118 Opening 200 for exposure Process cartridge 300 Recording paper (an example of a recording medium)
P Recording paper (an example of a recording medium)

Claims (5)

An image carrier,
A charging means having a charging member of a contact charging method for charging the surface of the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
Toner particles having a volume average particle size of 3.0 μm or more and 9.0 μm or less, lubricant particles, abrasive particles, and silica having a number average particle size of 80 nm to 200 nm and a shape factor SF2 of 130 to 180 Developing means for containing an electrostatic charge image developer containing toner having an external additive containing particles and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer When,
Transfer means for transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
Cleaning means having a cleaning blade for cleaning the surface of the image carrier;
Fixing means for fixing the toner image transferred to the surface of the recording medium;
Equipped with a,
The mass ratio of the silica particles to the lubricant particles (the silica particles / the lubricant particles) is 5 or more and 200 or less,
The mass ratio of the silica particles to the abrasive particles (the silica particles / the abrasive particles) is 3 or more and 20 or less,
The mass ratio of the lubricant particles and said abrasive particles (the lubricant particles / the abrasive particles) 1/15 to 2 der Ru image forming apparatus.   The image forming apparatus according to claim 1, wherein a contact pressure of the contact charging method charging unit with respect to the image holding member is 2N or more and 10N or less. The image forming apparatus according to claim 1, wherein the lubricant particles are zinc stearate particles. The image forming apparatus according to claim 1 , wherein the abrasive particles are strontium titanate particles. An image carrier,
A charging means having a charging member of a contact charging method for charging the surface of the image carrier;
Toner particles having a volume average particle size of 3.0 μm or more and 9.0 μm or less, lubricant particles, abrasive particles, and silica having a number average particle size of 80 nm to 200 nm and a shape factor SF2 of 130 to 180 Development in which an electrostatic charge image developer containing toner having an external additive containing particles is contained, and the electrostatic charge image formed on the surface of the image carrier is developed as a toner image by the electrostatic charge image developer. Means,
Cleaning means having a cleaning blade for cleaning the surface of the image carrier;
With
The mass ratio of the silica particles to the lubricant particles (the silica particles / the lubricant particles) is 5 or more and 200 or less,
The mass ratio of the silica particles to the abrasive particles (the silica particles / the abrasive particles) is 3 or more and 20 or less,
The mass ratio of the lubricant particles to the abrasive particles (the lubricant particles / the abrasive particles) is 1/15 or more and 2 or less,
A process cartridge attached to and detached from the image forming apparatus.

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