JP2010097201A - Toner and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner and an image forming method which suppress problematic filming and provide an image with high image quality and temporal stability, even in an image forming apparatus with a two-component development system adopting a non-contact AC roller charging system excellent in charge uniformity and charge controllability. <P>SOLUTION: The toner is obtained by externally adding an external additive to a base toner comprising at least a resin and a colorant, wherein the toner contains composite fine particles comprising at least inorganic fine particles and a lubricant. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a toner used as a developer and an image forming method using the toner when developing an electrostatic charge image formed by electrophotography, electrostatic recording, or the like.

  The image forming apparatus includes a charging step for uniformly charging an image forming area on the surface of the image carrier, an exposure step for writing on the image carrier, a developing step for forming an image with toner frictionally charged on the image carrier, The image is fixed on the printing paper after a transfer process in which the image on the image carrier is transferred directly to the printing paper or indirectly via an intermediate transfer body. Further, the untransferred toner remaining without being transferred onto the image carrier is scraped off from the image carrier by the cleaning process, and enters the next image forming process.

Conventional charging systems are mainly divided into two types depending on the bias system to be applied. DC charging with a bias applied to the contact charging member as DC, and AC charging with AC superimposed on DC.
AC charging is widely used in low- to medium-speed electrophotographic apparatuses because it is excellent in charging uniformity and charge potential controllability. As the charging member, a charging roller is mainly used (hereinafter, AC roller charging). Among these, the non-contact proximity charging method in which a minute gap is provided between the charging roller and the photosensitive member is widely used in machines that place great importance on durability because the charging roller is less contaminated than the contact method. In AC roller charging, it is necessary to discharge a certain number of times per unit length in the sub-scanning direction of an image in order to ensure charging uniformity, and the AC frequency is generally 6.0-7. .About 3 cycle / mm.

On the other hand, since AC charging repeats positive and negative discharges several times in the vicinity of the photoconductor, the hazard of discharge given to the photoconductor is larger than in the DC roller charging and corona charging methods, and the photoconductor thickness reduction and photoconductor There is a feature that it is easy to promote adhesion of foreign matter (hereinafter, filming) adhering to the surface.
These drawbacks are particularly prominent in wide machines such as high-speed machines, A3 machines, and A3 Nobi compatible machines. Since the span becomes longer, the mechanical accuracy of the roller is required, and the outer diameter of the roller is generally larger than that of a low-speed machine, so that the dischargeable area is expanded, and in particular, the influence of the AC charging hazard cannot be ignored. Further, in order to further improve the image quality and to ensure sufficient charging uniformity, an AC frequency of about 7.5 to 8.0 cycle / mm is required.

For these reasons, there are few machines that adopt the AC roller charging method in high-speed machines with a linear speed of 250 mm / s or higher.
Among them, there are machines that adopt the AC roller charging method even though they are high-speed machines. The non-contact method is adopted to realize the miniaturization of the main body, the resistance against the dirt of the roller is increased, and a certain long life is achieved. On the other hand, the widening of the gap also increases the AC charging hazard. There is a high possibility of ming. This has been dealt with by sufficiently applying a lubricant (such as zinc stearate) for protecting the photoreceptor. Therefore, in order to achieve a certain unit life, a large-sized lubricant must be loaded, and the amount of the loaded lubricant is rate-limiting.

In general, the toner used is a kneading and pulverizing method in which a resin, a pigment, a charge control agent, and a release agent are melt-kneaded, cooled and then pulverized and classified, but the particle size and shape are not uniform. These are difficult to control.
Under such circumstances, recently, there has been an attempt to control the particle size of toner particles intentionally to solve the above-mentioned problems, and polymerized toner methods such as emulsion polymerization method and dissolution suspension method as aqueous granulation. Became popular.

Furthermore, for the purpose of improving the flow characteristics, charging characteristics, etc. of the toner, it is common to use fine toner particles having an average particle diameter of 5 to 25 nm added and mixed as external additives. . For example, an invention in which silica, titanium dioxide or the like is externally added to improve fluidity is known. In addition, in order to improve the hydrophobicity and charging characteristics of the surface, an invention using an external additive surface-treated with an organosilicon compound such as silane or silicone oil is known. Inventions using titanium oxide or the like having low resistance are also known.
However, when these additives are added externally, for example, when used for a long time due to stress with the carrier of the two-component developer, the external additives on the toner surface are embedded in the toner, resulting in a decrease in toner fluidity. There is a problem that the desired fluidity cannot be maintained.

In recent years, in order to reduce embedding of the external additive, a method using a large particle size external additive is effective, and therefore, there is a tendency to add a large particle size external additive. The agent is easily separated from the toner, the large particle size external additive is selectively discharged from the developer, the small particle size external additive is embedded, the fluidity is lowered, and the image density is lowered, Alternatively, problems such as accumulation of large particle size external additives in the developer, development characteristics change, and background stains tend to occur.
Further, it is known that the charge imparting property of the carrier is reduced by the external additive being detached and attached to the carrier. This is largely related to the type of external additive, and it is known that the external additive having a lower resistance value has a stronger tendency to inhibit the carrier charge imparting property.

On the other hand, it is known that an external additive having a large particle size easily forms a film on the photosensitive drum, and the filmed photosensitive member causes image blur in a high temperature and high humidity environment.
Moreover, although filming is suppressed by performing sufficient lubricant application using the above-mentioned large-sized lubricant application process, the loading amount of the lubricant has become rate-limiting. Moreover, the effect is not sufficient.
Therefore, various improvements have been made so far in order to prevent the large particle size external additive from being detached from the toner. For example, when the external additive having a large particle size is resin particles, a method of immobilizing by physical force by treating for 2 minutes at 12000 rpm using a hybridization system has been proposed (Patent Document 1). However, this technique has a problem in that the charging performance of the base toner is deteriorated by the fixing process, and is difficult to employ.

On the other hand, it is known that lubricant particles are mixed with toner, but usually used lubricant particles have a particle size of about 3 μm, and it is difficult to supply a sufficient amount of lubricant. For this reason, when a large amount of lubricant is mixed, a phenomenon occurs in which the lubricant subjected to physical stress forms a film on the surface of the base toner, and problems such as a decrease in charge are observed.
In recent years, finely divided lubricant particles have attracted attention. Conversely, submicron-class lubricant particles have good adhesion to toner, making it difficult to sufficiently supply the lubricant.

  In Patent Document 2, in a toner in which an external additive is externally added to a base toner composed of at least a resin, a colorant, and a polarity control agent, the external additive is at least hydrophobized and has a hydrophobicity of 30 or more. A technique using a combination of inorganic oxide particles and a solid lubricant is disclosed. However, there is no mention of the particle size of the solid lubricant that affects the adhesion between the base toner and the solid lubricant, and it is difficult to control the adhesion due to the quantitative relationship between the solid lubricant and the inorganic fine particles. It is difficult to cause the solid lubricant to be present in an appropriate state in the toner only by simultaneously adding the solid lubricant and inorganic fine particles as described in the examples to the base material.

The subject of this invention is as follows.
Even in two-component development image forming devices that employ a non-contact AC roller charging system with excellent charging uniformity and charge controllability, the occurrence of filming, which is a problem, is suppressed, and the image quality is improved over time. A toner and an image forming method capable of obtaining a stable image are provided.

The present inventors have completed the present invention to solve the above-described problems.
As described above, the occurrence of filming is caused by a large particle size external additive (BET specific surface area of 20 to 40 m ² / g) externally added to the toner surface. Filming was suppressed by applying sufficient lubricant. However, the present inventors have found that by using a toner having composite fine particles composed of inorganic fine particles and a lubricant in the toner, filming can be suppressed without providing a large-size lubricant application mechanism.
That is, according to the present invention, a toner and an image forming method having the following characteristics are provided.

(1) A toner in which an external additive is externally added to a base toner comprising at least a resin and a colorant, wherein the toner contains at least composite fine particles comprising inorganic fine particles and a lubricant.
(2) The toner according to (1), wherein the composite fine particles are obtained by dispersing or fixing inorganic fine particles on the surface of a lubricant.
(3) The above (1) or (2), wherein the composite fine particles are formed by externally mixing inorganic fine particles with a lubricant, and the composite fine particles are externally added to the base toner. Toner.
(4) The toner according to any one of (1) to (3), wherein a primary particle size of the lubricant is 80 nm to 500 nm.
(5) The toner according to any one of (1) to (4), wherein the inorganic fine particles have a hydrophobicity of 50 to 90% and a BET specific surface area of 100 to 300 m ² / g.

(6) The toner according to any one of (1) to (5), wherein the toner includes a layered inorganic mineral obtained by modifying at least part of ions between layers of the layered inorganic mineral with organic ions.
(7) The base toner is obtained by dispersing and / or emulsifying an oil phase containing a toner composition containing at least a binder resin and / or a binder resin precursor and a colorant in an aqueous medium, and granulating it. The toner according to (6), wherein the toner composition comprises a layered inorganic mineral obtained by modifying at least part of ions between layers of the layered inorganic mineral with organic ions.

(8) An image carrier, a charging step for charging the surface of the image carrier, an exposure step for writing a latent image by exposing the image carrier, and developing a toner on the latent image written on the image carrier. Development process for forming a visible image, a transfer process for transferring the visible image to a recording medium or an intermediate transfer member, a fixing process for fixing the transferred image transferred to the recording medium, and the transfer process was not completed. In an image forming method having at least a cleaning step of cleaning transfer residual toner on an image carrier,
In the charging step, the image carrier is charged by non-contact AC charging,
The AC has an AC frequency of 6.5 to 8.5 cycles / mm,
The cleaning step is performed with a blade-shaped cleaning member,
A toner used for image formation is the toner described in any one of (1) to (7) above.
(9) In a process cartridge that integrally supports an image carrier and at least one unit selected from a charging unit, a developing unit, and a cleaning unit and is detachable from the main body of the image forming apparatus, the developing unit includes: A process cartridge which holds toner and is the toner according to any one of (1) to (7).

  According to the present invention, it is possible to obtain a toner that suppresses the occurrence of filming and obtains a high-quality and stable image over time, and employs a non-contact AC roller charging method that is excellent in charge uniformity and charge controllability. Also in the image forming method of the two-component development system, the occurrence of filming, which is a problem, is suppressed, and an image with high image quality and stable over time can be obtained.

1 is a schematic diagram illustrating a configuration of an image forming apparatus according to the present invention. It is the schematic which shows the structure of the other example of the image forming apparatus which concerns on this invention. It is the schematic which shows the structure of the other example of the image forming apparatus which concerns on this invention. 1 is a schematic diagram illustrating a configuration of a main part of an image forming apparatus according to the present invention. It is the chart figure which put the belt | band used for the image evaluation of an Example. It is the schematic which shows the structure of the process cartridge which concerns on this invention.

By using a toner having composite fine particles composed of inorganic fine particles and a lubricant, filming can be suppressed without providing a large lubricant application mechanism.
Composite fine particles composed of inorganic fine particles and a lubricant can be contained in the base toner, but by externally adding to the base toner, the adhesive force between the lubricant and the base toner is appropriately controlled, and the lubricant behaves in synchronization with the base toner. It is considered that the filming can be further suppressed by supplying the lubricant to the photoreceptor when developed.
In the present invention, the toner before the external additive is externally added is called a base toner, and the toner obtained by externally adding the external additive to the base toner is called a toner.

The lubricant is not particularly limited and may be appropriately selected depending on the intended purpose.For example, zinc stearate, calcium stearate, magnesium stearate, aluminum stearate, zinc oleate, zinc palmitate, magnesium palmitate, Examples thereof include zinc myristate, zinc laurate, and zinc behenate. Among these, zinc stearate is particularly preferable because sufficient environmental stability and chargeability can be obtained.
The primary particle size of the lubricant fine particles is preferably 80 nm to 500 nm. If it is smaller than 80 nm, the effect of suppressing the occurrence of photoconductor filming is small, and if it is larger than 500 nm, the adhesion to the toner becomes extremely weak and the toner is separated from the surface of the toner. The inorganic fine particles used for the composite fine particles are used for the purpose of controlling the adhesion of the lubricant particles to the toner.
The primary particle diameter of the lubricant fine particles can be measured by, for example, a particle size distribution measuring device Microtrac UPA (Nikkiso Co., Ltd.).

  The inorganic fine particles are not particularly limited and can be appropriately selected from known ones according to the purpose. For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate , Zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide , Silicon nitride, and the like. Among them, silica, alumina, and titanium oxide are particularly preferable as adhesion control.

The inorganic fine particles preferably have a BET specific surface area of 100 to 300 m ² / g. When the particle size is less than 100 m ² / g, the adhesion of the lubricant particles to the toner is insufficiently controlled. Further, those larger than 300 m ² / g are buried in the lubricant particles when dispersed and fixed in the lubricant particles, and the function becomes insufficient.
The BET surface area can be measured according to ASTM D3037-73.
The inorganic fine particles are preferably surface-treated from the viewpoint of chargeability. Surface treatment agent means a material that can be surface-treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, fluorination agents Examples thereof include silane coupling agents having an alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils. The inorganic fine particles are particularly preferably subjected to surface treatment with such a fluidity improver and used as hydrophobic inorganic fine particles having a hydrophobization degree of 50 to 90%.

The degree of hydrophobicity can be measured as follows.
--Method of measuring degree of hydrophobicity--
Add 50 ml of water to a 200 ml beaker and add 0.2 g of fine silica powder. Then, while gently stirring with a magnetic stirrer, add methanol from the burette where the tip was immersed in water at the time of dropping, and the floating silica fine powder began to sink. The following equation is used.
Hydrophobicity (%)
= (Ml of methanol dropped / (50 + ml of methanol dropped)) × 100
In this case, methanol acts as a surfactant, and as the silica fine powder that floats is dispersed in water via methanol as the methanol is dropped, the hydrophobicity of the silica fine powder increases as the value of the degree of hydrophobicity increases. The degree of conversion is high.

The composite fine particles comprising inorganic fine particles and a lubricant are preferably those in which inorganic fine particles are dispersed and fixed on the surface of the fine lubricant particles. As a method for dispersing and fixing the inorganic fine particles, the inorganic fine particles are dry-added and mixed into the lubricant. The dispersion method is preferable, but it is particularly preferable that the composite fine particles are prepared using a Q-type mixer or a hybridization system capable of giving a high share. In addition, after mixing the hydrophobic inorganic fine particles with a mixer such as a Henschel mixer, the inorganic fine particles are dispersed on the surface of the fine lubricant particles by passing the lubricant fine particles and the inorganic fine particles through a high-temperature airflow using a safffusion system or spray dryer. It can also be fixed.
The composite fine particles preferably contain 3 to 20 parts by mass of inorganic fine particles with respect to 100 parts by mass of the lubricant fine particles.

The composite fine particles are preferably externally added to the base toner, and the external addition method of the composite fine particles to the base toner is not particularly limited, and a general powder mixer is used, but equipped with a jacket, It is preferable that the internal temperature can be adjusted. In this case, you may change the rotation speed, rolling speed, time, temperature, etc. of a mixer. Also, a strong load may be given first, then a relatively weak load, or vice versa. Examples of the mixing equipment that can be used include a V-type mixer, a rocking mixer, a Ladige mixer, a Nauter mixer, and a Henschel mixer.
When composite fine particles are used in combination with an external additive, the composite fine particles may be attached before or after the external additive is attached to the base toner, or may be attached simultaneously.
The composite fine particles contained in the toner is preferably 0.1 to 5% by mass in the toner.

  Further, in the AC roller charging method, when the AC frequency is 8.5 cycles / mm or more, the number of discharges is large and charging hazard is likely to cause filming, but charging uniformity is increased. However, when the AC frequency is about 6.0 to 6.5 cycles / mm, the charging hazard is small, but the image quality is deteriorated. Therefore, by reducing the AC frequency to the limit range where image quality does not deteriorate to 6.5 to 8.5 cycles / mm, image quality is reduced by AC frequency reduction and image quality is reduced by filming caused by charging hazard. Both are suppressed and high image quality can be obtained.

  The base toner of the present invention is preferably prepared by aqueous granulation, and an oil phase containing at least a binder resin and / or a toner composition containing a binder resin precursor and a colorant is dispersed in an aqueous medium. The toner composition (hereinafter also referred to as toner material) preferably has a layered inorganic mineral obtained by modifying at least part of ions between layers of the layered inorganic mineral with organic ions. . The toner of the present invention is a toner obtained by externally adding composite fine particles composed of inorganic fine particles and a lubricant to the base toner, and more preferably at least three kinds or more of external additives (external additives) are adhered to the surface. Hereinafter, the constituent material and the manufacturing method of the toner will be described.

The modified layered inorganic mineral obtained by modifying at least part of interlayer ions in the layered inorganic mineral used in the present invention with organic ions will be described.
A layered inorganic mineral refers to an inorganic mineral formed by overlapping layers having a thickness of several nanometers, and modifying with organic ions means introducing organic ions into ions existing between the layers. Specifically, it is described in JP-T 2003-515795, JP-T 2006-500605, JP-T 2006-503313, and the like. This is called intercalation in a broad sense. As the layered inorganic mineral, smectite group (montmorillonite, saponite, etc.), kaolin group (kaolinite, etc.), magadiite, and kanemite are known. The modified layered inorganic mineral is highly hydrophilic due to its modified layered structure. Therefore, when used in toners that are dispersed in an aqueous medium and granulated without modifying the layered inorganic mineral, the layered inorganic mineral migrates into the aqueous medium and the toner cannot be deformed. By doing so, the hydrophilicity becomes high, and such a modified inorganic mineral becomes finer and deformed during the production of the toner, and particularly present on the surface portion of the toner particle, and it functions as a charge control and contributes to low-temperature fixing. To do. At this time, the content of the modified layered inorganic mineral in the toner material is preferably 0.05 to 10% by mass, and more preferably 0.05 to 5% by mass.

  The modified layered inorganic mineral used in the present invention is preferably one having a smectite basic crystal structure modified with an organic cation. Moreover, a metal anion can be introduce | transduced by substituting a part of bivalent metal of a layered inorganic mineral for a trivalent metal. However, since a hydrophilic property is high when a metal anion is introduced, a layered inorganic compound in which at least a part of the metal anion is modified with an organic anion is desirable.

  Examples of the organic ion modifier of the layered inorganic mineral obtained by modifying at least part of the ions of the layered inorganic mineral with organic ions include quaternary alkyl ammonium salts, phosphonium salts and imidazolium salts. A quaternary alkyl ammonium salt is desirable. Examples of the quaternary alkylammonium include trimethylstearylammonium, dimethylstearylbenzylammonium, dimethyloctadecylammonium, oleylbis (2-hydroxyethyl) methylammonium and the like.

  Examples of the organic ion modifier include branched, unbranched or cyclic alkyl (C1-C44), alkenyl (C1-C22), alkoxy (C8-C32), hydroxyalkyl (C2-C22), ethylene oxide, propylene oxide, and the like. Sulfates, sulfonates, carboxylates, or phosphates having A carboxylic acid having an ethylene oxide skeleton is desirable.

By modifying at least part of the layered inorganic mineral with organic ions, it has moderate hydrophobicity, the oil phase containing the toner composition and / or toner composition precursor has non-Nutnian viscosity, and the toner is deformed Can be At this time, the content of the layered inorganic mineral obtained by modifying a part of the toner material with organic ions is preferably 0.05 to 10% by mass, and more preferably 0.05 to 5% by mass.
The layered inorganic mineral partially modified with organic ions can be appropriately selected, and examples thereof include montmorillonite, bentonite, hectorite, attapulgite, sepiolite, and mixtures thereof. Among these, organically modified montmorillonite or bentonite is preferable because the viscosity can be easily adjusted without affecting the toner characteristics and the addition amount can be reduced.

  Commercially available layered inorganic minerals partially modified with an organic cation include Bentone 3, Bentone 38, Bentone 38V (above, manufactured by Leox), Thixogel VP (manufactured by United catalyst), Kraton 34, Kraton 40, Kraton XL Quartium 18 bentonite such as (made by Southern Clay), and stearalkonium bentonite such as Bentone 27 (made by Leox), Thixogel LG (made by United catalyst), Clayton AF, Clayton APA (made by Southern Clay) Quaternium 18 / benzalkonium bentonite such as Clayton HT and Clayton PS (manufactured by Southern Clay). Particularly preferred are Clayton AF and Clayton APA.

Moreover, as a layered inorganic mineral partially modified with an organic anion, a material obtained by modifying DHT-4A (manufactured by Kyowa Chemical Industry Co., Ltd.) with an organic anion represented by the following general formula (1) is particularly preferable. The following general formula (1) is, for example, Hytenol 330T (Daiichi Kogyo Seiyaku Co., Ltd.).
General formula (1)
R ¹ (OR ² ) nOSO ₃ M
[Wherein, R ¹ represents an alkyl group having 13 carbon atoms, and R ² represents an alkylene group having 2 to 6 carbon atoms. n represents an integer of 2 to 10, and M represents a monovalent metal element]

  By using the modified layered inorganic mineral, it has moderate hydrophobicity, and the oil phase containing the toner composition has a non-Newtonian viscosity in the production process of the toner having this, and the toner can be deformed.

As the external additive (external additive), inorganic fine particles can be used. The inorganic fine particles can be used as an external additive for imparting fluidity, developability, chargeability and the like to the toner particles.
The inorganic fine particles are not particularly limited and may be appropriately selected from known ones according to the purpose. For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, titanate Strontium, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, carbonized Examples include silicon and silicon nitride. In particular it is preferable to add three or more external additives, the kind is hydrophobic silica fine particles of 20 to 40 m ² / g BET specific surface area, yet another one is a BET specific surface area 40 to 80 m ² / It is preferable that the hydrophobic titanium oxide fine particles are g, and the other is hydrophobic silica fine particles having a BET specific surface area value of 130 to 300 m ² / g. Further, three or more kinds of external additives may be added as a function.
The content of the inorganic fine particles in the toner is preferably 0.01 to 5.0% by mass, and more preferably 0.01 to 2.0% by mass.

  The inorganic fine particles may be surface-treated with a fluidity improver in order to improve fluidity. The fluidity improver means a material that can be surface treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, a silane coupling agent, a silylating agent, a fluoride. Silane coupling agents having an alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils, and the like. It is particularly preferable that the silica and the titanium oxide are surface-treated with such a fluidity improver and used as hydrophobic silica and hydrophobic titanium oxide.

  As the external additive, a cleaning property improving agent may be used. The cleaning improver is added to the toner in order to remove the developer after transfer remaining on the photoreceptor or the primary transfer medium, and includes, for example, fatty acid metal salts such as zinc stearate, calcium stearate, stearic acid, and the like. Examples thereof include polymer fine particles produced by soap-free emulsion polymerization such as methyl methacrylate fine particles and polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution, and those having a volume average particle size of 0.01 to 1 μm are suitable.

  Organic fine particles can also be added as an external additive. The organic fine particles are not particularly limited and can be appropriately selected depending on the purpose. For example, polystyrene, methacrylic acid ester or acrylic acid ester copolymer obtained by soap-free emulsion polymerization, suspension polymerization, or dispersion polymerization can be used. Examples thereof include polycondensation systems such as silicone, benzoguanamine, and nylon, and polymer particles made of a thermosetting resin.

-External additive addition process-
The external additive adding step is performed by first dispersing and fixing inorganic fine particles in the lubricant particles to prepare composite fine particles, and then externally adding the composite fine particles and the external additive to the base toner. By passing through the above sieve, coarse particles and aggregated particles are removed, and a toner is obtained.

  The average circularity of the toner of the present invention is preferably from 0.925 to 0.970, more preferably from 0.945 to 0.965. The circularity is a value obtained by dividing the circumference of a circle having an area equal to the projected area of the sample by the circumference of the sample. The content of particles having a circularity of less than 0.925 in the toner is preferably 15% or less. If the average circularity is less than 0.925, satisfactory transferability and a high-quality image free from dust may not be obtained. If it exceeds 0.970, an image forming apparatus employing blade cleaning or the like may not be used. In addition, poor cleaning of the photosensitive member and the transfer belt may occur, and stains on the image may occur. For example, when forming an image with a high image area ratio, such as a photographic image, toner that has formed an untransferred image due to poor paper feed or the like accumulates on the photoconductor, causing image smudges or touching the photoconductor The charging roller or the like to be charged may be contaminated and the original charging ability may not be exhibited.

  The average circularity can be measured by an optical detection band method in which a suspension containing toner is passed through an imaging unit detection band on a flat plate, a particle image is optically detected by a CCD camera, and analyzed. It can be measured using a flow type particle image analyzer FPIA-2100 (manufactured by Sysmex Corporation).

  In the toner of the present invention, the ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is preferably 1.00 to 1.30, which is high resolution and high image quality. It is possible to obtain the toner. Furthermore, in the case of a two-component developer, even if a long-term balance of the toner is performed, fluctuations in the particle size of the toner in the developer are reduced, and good and stable developability even with long-term stirring in the developing device. Is possible. If Dv / Dn exceeds 1.30, the variation in particle size of individual toner particles is large, and the behavior of the toner varies during development and the like, and the reproducibility of minute dots is impaired. Therefore, a high-quality image cannot be obtained. More preferably, Dv / Dn is in the range of 1.00 to 1.20, and a better image can be obtained.

  In the toner of the present invention, the volume average particle diameter (Dv) is preferably 3.0 to 7.0 μm. In general, it is said that the smaller the particle size of the toner, the more advantageous it is to obtain a high-resolution and high-quality image, but it is disadvantageous for transferability and cleaning properties. is there. When the volume average particle diameter is smaller than the above range, in the case of a two-component developer, the toner is fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier is reduced. When it is used, toner filming on the developing roller and toner fusion to a member such as a blade for thinning the toner are likely to occur. These phenomena are greatly related to the content of fine powders. In particular, when the number of particles having a particle size of 2 μm or less exceeds 20% by number, it becomes a hindrance in the case where adhesion to a carrier or charging stability at a high level is achieved. Conversely, when the toner particle size is larger than the above range, it becomes difficult to obtain a high-resolution and high-quality image, and the toner particle size when the balance of the toner in the developer is performed. In many cases, fluctuations of It was also clarified that the same applies when the volume average particle diameter / number average particle diameter is larger than 1.30.

  As described above, a toner having a small particle size and a uniform particle size has difficulty in cleaning properties. Therefore, it is preferable that 20-80% of the toner particles have a circularity of 0.950 or less.

  First, the relationship between toner shape and transferability will be described. When using a full-color copier that transfers images with multi-color development, the amount of toner on the photoconductor increases compared to the case of one-color black toner used in black-and-white copiers. It is difficult to improve transfer efficiency. In addition, when ordinary irregular toner is used, a shearing force or friction between the photosensitive member and the cleaning member, between the intermediate transfer member and the cleaning member, and / or between the photosensitive member and the intermediate transfer member. Due to the force, toner fusing or filming occurs on the surface of the photoreceptor or the intermediate transfer member, and transfer efficiency tends to deteriorate. When generating a full-color image, it is difficult to transfer the four-color toner images uniformly. Furthermore, when an intermediate transfer member is used, problems are likely to occur in terms of color unevenness and color balance, and high-quality full-color images are stabilized. Output is not easy.

  From the viewpoint of a balance between blade cleaning and transfer efficiency, particles having a toner circularity of 0.950 or less are 20 to 80% of the total toner particles, thereby achieving both cleaning and transferability. Cleaning and transferability are greatly related to the material of the blade and how to apply the blade, and transfer also varies depending on the process conditions, so that the design according to the process can be performed within the above range. However, if the toner circularity is 0.950 or less than 20% of all toner particles, cleaning with a blade becomes difficult. On the other hand, when the particles having a circularity of 0.950 or less exceed 80% of the total toner particles, the above-described transferability is deteriorated. This phenomenon is caused by excessively deformed toner shape, so that toner movement during transfer (photosensitive member surface to transfer paper, photosensitive member surface to intermediate transfer belt, first intermediate transfer belt to second intermediate transfer belt) , Etc.) are not smooth, and the toner particles vary in behavior, so that uniform and high transfer efficiency cannot be obtained. In addition, unstable charging and brittleness of particles begin to appear. Furthermore, it becomes a pulverization phenomenon in the developer, which causes a decrease in the durability of the developer.

Hereafter, the measuring method regarding the property of the toner of this invention is shown.
(Particle ratio of particle size of 2 μm or less, circularity)
The particle ratio of 2 μm or less, the circularity and the average circularity of the toner of the present invention can be measured by a flow type particle image analyzer FPIA-2000 (manufactured by Toa Medical Electronics Co., Ltd.). As a specific measuring method, 0.1 to 0.5 ml of a surfactant, preferably alkylbenzene sulfonate is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance, and further measurement is performed. Add about 0.1-0.5g of sample. The suspension in which the sample is dispersed is obtained by performing dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and measuring the shape and distribution of the toner with the above apparatus at a dispersion concentration of 3000 to 10,000 / μl. .

(Toner particle size)
The average particle size and particle size distribution of the toner are determined by the Carcoulter counter method. Examples of the measuring device for the particle size distribution of the toner particles include Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). In the present invention, measurement was performed using a Coulter Counter TA-II type connected to an interface (Nichiken Giken) that outputs number distribution and volume distribution and a PC9801 personal computer (manufactured by NEC).

The measurement method is described below.
First, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of an aqueous electrolytic solution. Here, the electrolytic solution is a solution prepared by preparing a 1% NaCl aqueous solution using primary sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the measurement device is used to measure the volume and number of toner particles or toner using a 100 μm aperture as an aperture. Volume distribution and number distribution are calculated.

  As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm. The volume-based volume average particle diameter (Dv) obtained from the volume distribution according to the present invention and the number average particle diameter (Dn) obtained from the number distribution and the ratio Dv / Dn were obtained.

  The toner of the present invention is preferably obtained by dispersing and / or emulsifying an oil phase containing a toner material containing at least the modified layered inorganic mineral in an aqueous medium, and at least in an organic solvent. Dissolving or dispersing a first binder resin, a binder resin precursor, a compound that extends or crosslinks with the binder resin precursor, a colorant, a release agent, and the modified layered inorganic mineral, A solution or dispersion (oil phase) is preferably obtained by a crosslinking reaction and / or elongation reaction in an aqueous medium and removing the solvent from the obtained dispersion.

  The binder resin precursor used in the present invention is preferably a reactive modified polyester resin (RMPE) capable of reacting with active hydrogen, and examples thereof include a polyester prepolymer (A) having an isocyanate group. Examples of the prepolymer (A) include a polycondensate of a polyol (PO) and a polycarboxylic acid (PC) and a polyester having active hydrogen further reacted with a polyisocyanate (PIC). Examples of the group containing active hydrogen in the polyester include a hydroxyl group (alcoholic hydrogen group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable.

An amine is used as a crosslinking agent for the reactive modified polyester resin, and a diisocyanate compound (diphenylmethane diisocyanate or the like) is used as an extender. The amines described in detail later act as a crosslinking agent and an extender for the modified polyester capable of reacting with active hydrogen.
Modified polyester such as urea-modified polyester obtained by reacting the polyester prepolymer (A) having an isocyanate group with an amine (B) can easily adjust the molecular weight of the polymer component, and is a dry toner, particularly oilless low-temperature fixing. It is convenient to ensure the characteristics (wide releasability and fixability without a release oil application mechanism to the fixing heating medium). Particularly, a polyester prepolymer whose end is modified with urea can suppress adhesion to a heating medium for fixing while maintaining high fluidity and transparency in the fixing temperature range of the unmodified polyester resin itself.

  A preferred polyester prepolymer used in the present invention is a polyester having an active hydrogen group such as an acid group or a hydroxyl group at the terminal, and a functional group such as an isocyanate group that reacts with the active hydrogen. A modified polyester (MPE) such as urea-modified polyester can be derived from this prepolymer, but in the case of the present invention, a preferred modified polyester used as a toner binder is a polyester prepolymer (A) having an isocyanate group. It is a urea-modified polyester obtained by reacting amines (B) as a crosslinking agent and / or an extender. The polyester prepolymer (A) having an isocyanate group is obtained by further reacting a polyester having an active hydrogen group, which is a polycondensate of a polyol (PO) and a polycarboxylic acid (PC), with a polyisocyanate (PIC). Can do. Examples of the active hydrogen group possessed by the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like. Among these, alcoholic hydroxyl groups are preferred.

  Examples of the polyol (PO) include a diol (DIO) and a trivalent or higher polyol (TO), and (DIO) alone or a mixture of (DIO) and a small amount of (TO) is preferable. Diol (DIO) includes alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol, triethylene glycol, Ethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol F, Bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide phenol compound (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. Trivalent or higher polyols (TO) include 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trivalent or higher phenols (Tris) Phenol PA, phenol novolak, cresol novolak, etc.); alkylene oxide adducts of the above trivalent or more polyphenols.

  Examples of the polycarboxylic acid (PC) include dicarboxylic acid (DIC) and trivalent or higher polycarboxylic acid (TC), and DIC alone or a mixture of DIC and a small amount of (TC) is preferable. Dicarboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid, naphthalene) Dicarboxylic acid and the like). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polycarboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polycarboxylic acid (PC), you may make it react with a polyol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.). The ratio of the polyol (PO) and the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably 1 as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. 5/1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

  As polyisocyanate (PIC), aliphatic polyisocyanate (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanate (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic Diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; polyisocyanates such as phenol derivatives, oximes, caprolactams, etc. And a combination of two or more of these.

  The ratio of the polyisocyanate (PIC) is usually 5/1 to 1/1, preferably 4 /, as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a modified polyester is used, the urea content in the ester becomes low and the hot offset resistance deteriorates. The content of the polyisocyanate (3) component in the prepolymer (A) having an isocyanate group at the terminal is usually 0.5 to 40% by mass, preferably 1 to 30% by mass, more preferably 2 to 20% by mass. It is. If it is less than 0.5% by mass, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40% by mass, the low-temperature fixability deteriorates.

  The number of isocyanate groups contained per molecule in the prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2.5 on average. It is. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

  As amines (B), diamine (B1), trivalent or higher polyamine (B2), aminoalcohol (B3), aminomercaptan (B4), amino acid (B5), and amino acids B1-B5 blocked (B6) etc. are mentioned. Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, Isophorone diamine etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine etc.) and the like. Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of the compound (B6) obtained by blocking the amino group of B1 to B5 include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

  Furthermore, if necessary, the molecular weight of the polyester can be adjusted using an elongation terminator. Examples of the elongation terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

  The ratio of amines (B) is the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). The ratio is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the polyester is lowered and the hot offset resistance is deteriorated.

  In the present invention, the polyester resin (polyester) that is preferably used as a toner binder is urea-modified polyester (UMPE), but this polyester may contain a urethane bond as well as a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

  Modified polyester such as urea-modified polyester (UMPE) is produced by a one-shot method or the like. The weight average molecular weight of the modified polyester such as urea-modified polyester (UMPE) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of a modified polyester such as a urea-modified polyester is not particularly limited when an unmodified polyester (PE) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. In the case of a modified polyester such as UMPE alone, the number average molecular weight is usually 2000-15000, preferably 2000-10000, and more preferably 2000-8000. If it exceeds 15000, the low-temperature fixability and the gloss when used in a full-color device are deteriorated.

  In the present invention, the above modified polyester such as polyester modified with urea bond (UMPE) is not only used alone, but can also contain unmodified polyester (PE) as a binder resin component. . The combined use of PE improves low-temperature fixability and gloss when used in a full-color device, and is preferable to single use. Examples of PE include polycondensates of polyol PO and polycarboxylic acid PC similar to the polyester component of UMPE, and preferred ones are also the same as in UMPE. The weight average molecular weight (Mw) of PE is 10,000 to 300,000, preferably 14,000 to 200,000. Its Mn (number average molecular weight) is 1000 to 10000, preferably 1500 to 6000. For UMPE, not only unmodified polyesters but also those modified with chemical bonds other than urea bonds, such as those modified with urethane bonds, can be used in combination. UMPE and PE are preferably at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Therefore, the polyester component of UMPE and PE are preferably similar in composition. The mass ratio of UMPE to PE when PE is contained is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, and particularly preferably 7/93. ~ 20/80. If the mass ratio of UMPE is less than 5%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

The hydroxyl value (mgKOH / g) of PE is preferably 5 or more.
In addition, by setting the acid value of the polyester resin as the first binder resin to 1.0 to 50.0 (mgKOH / g), particle size control by adding a base compound, low temperature fixability, high temperature offset resistance, Toner properties such as heat-resistant storage stability and charging stability can be improved. That is, when the acid value exceeds 50.0 (mgKOH / g), the elongation or cross-linking reaction of the binder resin precursor becomes insufficient, affecting the high-temperature offset resistance, and 1.0 (mgKOH / g If it is less than), the dispersion stabilizing effect due to the base compound at the time of production cannot be obtained, and the elongation or crosslinking reaction of the binder resin precursor tends to proceed, resulting in problems in production stability.

(Method for measuring acid value of resin)
Measurement is performed under the following conditions in accordance with the measurement method described in JIS K0070-1992.
Sample preparation: 0.5 g of polyester is added to 120 ml of THF and dissolved by stirring at room temperature (23 ° C.) for about 10 hours. Further, 30 ml of ethanol is added to prepare a sample solution.
The measurement can be calculated by the apparatus described below. Specifically, it is calculated as follows.
Titrate with a pre-standardized N / 10 caustic potash to alcohol solution, and determine the acid value from the consumption of the alcohol potash solution by the following calculation.
Acid value = KOH (ml) x N x 56.1 / sample mass (where N is a factor of N / 10 KOH)

The detail of the measuring method of the acid value of the polyester resin of this invention is based on the following method based on JISK0070. THF is used as the solvent.
The acid value is specifically determined by the following procedure.
Measuring device: Potentiometric automatic titrator DL-53 Titrator (Metler Toledo)
Electrode used: DG113-SC (manufactured by METTLER TOLEDO)
Analysis software: LabX Light Version 1.00.000
Calibration of the apparatus: Use a mixed solvent of 120 ml of toluene and 30 ml of ethanol.
Measurement temperature: 23 ° C

The measurement conditions are as follows.
Stir
Speed [%] 25
Time [s] 15
EQP titration
Titrant / Sensor
TitrantCH3ONa
Concentration [mol / L] 0.1
Sensor DG115
Unit of measurement mV
Predispensing to volume
Volume [mL] 1.0
Wait time [s] 0
Titrant addition Dynamic
dE (set) [mV] 8.0
dV (min) [mL] 0.03
dV (max) [mL] 0.5
Measure mode Equilibrium controlled
dE [mV] 0.5
dt [s] 1.0
t (min) [s] 2.0
t (max) [s] 20.0
Recognition
Threshold 100.0
Steepest jump onlyNo
Range No
Tendency None
Termination
at maximum volume [mL] 10.0
at potential No
at slope No
after number EQPs Yes
n = 1
comb. termination conditions No
Evaluation
Procedure Standard
Potential 1 No
Potential 2 No
Stop for reevaluation No

(Measurement method of hydroxyl value)
The conditions of the measuring apparatus are the same as those in the above acid value measurement.
Weigh accurately 0.5 g of sample into a 100 ml volumetric flask and add 5 ml of acetylating reagent correctly. Then, it is immersed in a bath at 100 ° C. ± 5 ° C. and heated. After 1-2 hours, the flask is removed from the bath, allowed to cool, water is added and shaken to decompose acetic anhydride. Furthermore, in order to complete the decomposition, the flask is again heated in a bath for 10 minutes or more and allowed to cool, and then the wall of the flask is thoroughly washed with an organic solvent. This solution is subjected to potentiometric titration with an N / 2 potassium hydroxide ethyl alcohol solution using the electrode to determine the OH value (according to JISK0070-1966).

  According to a further study of the present invention, it becomes a prepolymer precursor to effectively exhibit low-temperature fixability while maintaining heat-resistant storage stability and to impart offset resistance after modification with a prepolymer. It is preferable that the weight-average molecular weight of the THF-soluble component of the polyester resin is 1,000 to 30,000. This is because when the amount is less than 1,000, the oligomer component increases, the heat-resistant storage stability is deteriorated, and when it exceeds 30,000, the modification with the prepolymer is insufficient due to steric hindrance and the offset resistance is deteriorated.

The molecular weight of the resin according to the present invention is measured by GPC (gel permeation chromatography) as follows. The column was stabilized in a heat chamber at 40 ° C., and THF was added to the column at this temperature as a solvent at a flow rate of 1 ml / min. Is measured by injecting 50 to 200 μl. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of the prepared calibration curve and the count using several types of monodisperse polystyrene standard samples. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical Co. Alternatively, the molecular weights of Toyo Soda Kogyo Co., Ltd. are 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9. It is appropriate to use x10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

  In the present invention, the heat-resistant storage performance of the main component of the polyester resin after modification, that is, the binder resin depends on the glass transition point of the polyester resin before modification, so the glass transition point of the first polyester resin is 35 ° C. to 35 ° C. It is preferable to design at 65 ° C. That is, if it is less than 35 ° C., the heat-resistant storage stability is insufficient, and if it exceeds 65 ° C., it adversely affects low-temperature fixing.

The glass transition point of the present invention is measured with a Rigaku THRMOFLEX TG8110 manufactured by Rigaku Corporation at a temperature increase rate of 10 ° C./min.
A method for measuring Tg will be outlined. As an apparatus for measuring Tg, a TG-DSC system TAS-100 manufactured by Rigaku Corporation was used.
First, about 10 mg of a sample is placed in an aluminum sample container, which is placed on a holder unit and set in an electric furnace. First, after heating from room temperature to 150 ° C. at a temperature rising rate of 10 ° C./min, the sample was allowed to stand at 150 ° C. for 10 min, the sample was cooled to room temperature and left for 10 min, and the temperature rising rate was again increased to 150 ° C. under a nitrogen atmosphere. DSC measurement was performed by heating at min. Tg was calculated from the tangent of the endothermic curve near the Tg and the base line using the analysis system in the TAS-100 system.

  According to a further study of the present invention, the prepolymer to be a modified polyester resin is an important binder resin component for realizing low-temperature fixability and high-temperature offset resistance, and its weight average molecular weight is 3,000 to 20, 000 is preferred. That is, when the weight average molecular weight is less than 3,000, it becomes difficult to control the reaction rate, and problems in production stability begin to occur. On the other hand, when the weight average molecular weight exceeds 20,000, sufficient modified polyester cannot be obtained and the offset resistance starts to be affected.

  Further examination of the present invention revealed that the toner acid value is a more important index than the binder resin acid value for low-temperature fixability and high-temperature offset resistance. The toner acid value of the present invention is derived from the terminal carboxyl group of the unmodified polyester. In order to control low-temperature fixability (fixing lower limit temperature, hot offset occurrence temperature, etc.) as a toner, it is preferable that the acid value of the toner be 0.5 to 40.0 (mgKOH / g). That is, when the toner acid value exceeds 40.0 (mgKOH / g), the extension or crosslinking reaction of the modified polyester becomes insufficient, and the high temperature offset resistance is affected, and less than 0.5 (mgKOH / g). In this case, the dispersion stabilizing effect due to the base compound at the time of production cannot be obtained, and the extension or crosslinking reaction of the modified polyester tends to proceed, resulting in a problem in production stability.

Specifically, the acid value of the toner is determined in accordance with the method for measuring the acid value of the polyester resin. When there is THF-insoluble matter, the acid value of the toner refers to the acid value when the acid value is measured using THF as a solvent.
(Method for measuring acid value of toner)
Measurement is performed under the following conditions in accordance with the measurement method described in JIS K0070-1992. Sample preparation: 0.5 g of toner (0.3 g for ethyl acetate-soluble component) was used in place of the polyester.

  In the present invention, the glass transition point (Tg) of the toner is usually 40 to 70 ° C., preferably 40 to 60 ° C., in order to obtain heat resistant storage stability and high durability. If the temperature is lower than 40 ° C., the heat resistance of the toner is deteriorated, and blocking in the developing machine and filming on the photosensitive member are liable to occur. If the temperature is higher than 70 ° C., the low-temperature fixability is insufficient. Due to the coexistence of a modified polyester such as a urea-modified polyester resin, the dry toner of the present invention tends to have good heat-resistant storage stability even when the glass transition point is low, as compared with a known polyester-based toner.

(Release agent)
As the release agent (wax) used for the toner of the present invention, a low melting point wax having a melting point of 50 to 120 ° C. is more effectively used as a release agent in the dispersion with the binder resin. Thus, it exhibits an effect on high temperature offset resistance without applying a release agent such as oil to the fixing roller.
The melting point of the wax in the present invention was the maximum endothermic peak measured by a differential scanning calorimeter (DSC).

  The following materials can be used as the wax component that functions as a release agent that can be used in the present invention. That is, as specific examples, waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, And petroleum waxes such as paraffin, microcrystalline, and petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones and ethers can be used. Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, and chlorinated hydrocarbon, and poly n-stearyl methacrylate and poly n-lauryl methacrylate which are low molecular weight crystalline polymer resins A crystalline polymer having a long alkyl group in the side chain, such as a polyacrylate homopolymer or copolymer (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used.

(Coloring agent)
As the colorant used in the present invention, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow Iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Tan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R , Para red, phissa red, parac Luort Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carnmin BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pi Zoron Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indance Ren Blue (RS, BC), Indigo, Ultramarine Blue, Bituminous Blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian, Emerald Green , Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Gree Lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by mass, preferably 3 to 10% by mass with respect to the toner.

The colorant used in the present invention can also be used as a master batch combined with a resin.
As the binder resin to be kneaded together with the production of the masterbatch or the masterbatch, in addition to the above-mentioned modified and unmodified polyester resins, styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene, and polymers of substitution products thereof. Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer Polymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α -Methyl chloromethacrylate copolymer, styrene -Acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid Styrenic copolymers such as ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacryl Acid resins, rosins, modified rosins, terpene resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be used, and these can be used alone or in combination.

  The master batch can be obtained by mixing and kneading a resin for a master batch and a colorant under a high shear force to obtain a master batch. In this case, an organic solvent can be used in order to enhance the interaction between the colorant and the resin. Also, a so-called flushing method called watering paste containing water of a colorant is mixed and kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove moisture and organic solvent components. Since it can be used as it is, it does not need to be dried and is preferably used. For mixing and kneading, a high shear dispersion device such as a three-roll mill is preferably used.

  The toner of the present invention may contain a charge control agent as necessary. Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salts or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Nitronine-based dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, oxynaphthoic acid metal complex E-82, salicylic acid metal complex E- 84, E-89 of a phenol-based condensate (manufactured by Orient Chemical Industry Co., Ltd.), TP-302 of a quaternary ammonium salt molybdenum complex, TP-415 (manufactured by Hodogaya Chemical Industry Co., Ltd.), quaternary ammonium Copy charge PSY VP2038 of salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit), copper phthalocyanine, perylene, quinaclide And azo pigments, and other high molecular compounds having a functional group such as a sulfonic acid group, a carboxyl group, and a quaternary ammonium salt.

  In the present invention, the amount of charge control agent used is determined uniquely by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is uniquely limited. Although it is not a thing, Preferably it is used in 0.1-10 mass parts with respect to 100 mass parts of binder resin. Preferably, the range of 0.2-5 mass parts is good. When the amount exceeds 10 parts by mass, the chargeability of the toner is too high, the effect of the main charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the flowability of the developer is reduced, and the image density Incurs a decline. These charge control agents and mold release agents can be melt-kneaded together with the masterbatch and resin, and of course, they may be added when dissolved and dispersed in an organic solvent.

  The binder resin can be produced by the following method. Polyol (PO) and polycarboxylic acid (PC) are heated to 150-280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate, dibutyltin oxide, etc., and the generated water is distilled off as necessary. Thus, a polyester having a hydroxyl group is obtained. Next, this is reacted with polyisocyanate (PIC) at 40 to 140 ° C. to obtain a polyester prepolymer (A) having an isocyanate group. Further, this A is reacted with amines (B) at 0 to 140 ° C. to obtain a polyester (UMPE) modified with a urea bond. The number average molecular weight of this modified polyester is 1000 to 10000, preferably 1500 to 6000. When reacting PIC and when reacting A and B, a solvent can be used if necessary. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to isocyanates (PIC), such as tetrahydrofuran (such as tetrahydrofuran). When polyester (PE) that is not modified with a urea bond is used in combination, PE is produced in the same manner as the polyester having a hydroxyl group, and this is dissolved in the solution after completion of the UMPE reaction and mixed.

The dry toner of the present invention can be produced by the following method, but is not limited thereto.
(Toner production method in aqueous medium)
As the aqueous medium used in the present invention, water alone may be used, but 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 (methylcellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.) and the like.

  In the present invention, a urea-modified polyester (UMPE) or the like can be obtained by reacting a reactive modified polyester such as a polyester prepolymer (A) having an isocyanate group with an amine (B) in an aqueous medium. As a method for stably forming a dispersion comprising a modified polyester such as urea-modified polyester or a reactive modified polyester such as prepolymer (A) in an aqueous medium, a modified polyester such as urea-modified polyester or a pre-polymer can be used in an aqueous medium. Examples thereof include a method in which an oil phase containing a component of a toner material containing a reactive modified polyester such as polymer (A) is added and dispersed by shearing force. Reactive modified polyester such as prepolymer (A) and other toner components such as colorant, colorant masterbatch, release agent, charge control agent, unmodified polyester resin, etc. form a dispersion in an aqueous medium. However, it is more preferable to mix the toner material in advance and then add and disperse the mixture in the aqueous medium. In the present invention, other toner materials such as a colorant, a release agent, and a charge control agent do not necessarily have to be mixed when forming particles in an aqueous medium, but after the particles are formed. , May be added. For example, after forming particles containing no colorant, the colorant can be added by a known dyeing method.

  The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. In order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing type is preferable. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C. Higher temperatures are preferred in that the dispersion made of urea-modified polyester or prepolymer (A) has a low viscosity and is easily dispersed.

  The amount of the aqueous medium used is usually 50 to 2000 parts by mass, preferably 100 to 1000 parts by mass with respect to 100 parts by mass of the toner composition containing polyester such as urea-modified polyester and prepolymer (A). If the amount is less than 50 parts by mass, the dispersion state of the toner composition is poor, and toner particles having a predetermined particle size cannot be obtained. If it exceeds 20000 parts by mass, it is not economical. Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.

Various dispersing agents for emulsifying and dispersing are used in the aqueous medium in which the oil phase in which the toner composition is dispersed is dispersed and / or emulsified. Such a dispersant includes a surfactant, an inorganic fine particle dispersant, a polymer fine particle dispersant and the like.
As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, polyhydric alcohol Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine. It is.

  Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [omega-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [omega-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts thereof, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- (2-hydroxyethyl ) Perfluorooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate Etc.

  Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (Daikin Kogyo Co., Ltd.), MegaFuck F-110, F-120, F-113, F-191, F-812, F-833 (Dainippon Ink Co., Ltd.), Xtop EF-102 , 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  Examples of the cationic surfactant include aliphatic primary, secondary or tertiary amine acids having a fluoroalkyl group, aliphatic quaternary ammonium salts such as perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, benza Luconium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass), Florard FC-135 (Sumitomo 3M), Unidyne DS-202 (Daikin Industries) Megafac F-150, F-824 (manufactured by Dainippon Ink, Inc.), Xtop EF-132 (manufactured by Tochem Products), and Footgent F-300 (manufactured by Neos).

In addition, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite and the like can be used as an inorganic compound dispersant that is hardly soluble in water.
Further, the same effect as that of the inorganic dispersant was confirmed for the polymer fine particles. For example, MMA polymer fine particles 1 μm and 3 μm, styrene fine particles 0.5 μm and 2 μm, styrene-acrylonitrile fine particle polymer 1 μm, (PB-200H (Kao) SGP (Soken), Technopolymer SB (Sekisui Plastics), SGP-3G (Soken) Micropearl (Sekisui Fine Chemical)).

  In addition, as a dispersant that can be used in combination with the above inorganic dispersant and fine particle polymer, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-acrylate Chloro-2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N -Methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, etc., or esters of compounds containing vinyl alcohol and carboxyl groups, such as Pinyl acetate, pinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, pinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethylene imine, etc. Homopolymers or copolymers such as those having nitrogen atoms or heterocyclic rings thereof, polyoxyethylene, polyoxypropylene, polymers Oxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonylphenyl Polyoxyethylenes such as esters, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

In order to produce coalesced particles by stirring and converging the obtained emulsified dispersion (reactant) in a certain temperature range lower than the resin glass transition temperature and the organic solvent concentration range, The shaped toner particles can be produced by gradually raising the temperature in a laminar stirring state and removing the solvent. In addition, when an acid such as calcium phosphate salt or an alkali-soluble substance is used as the dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. To do. It can also be removed by operations such as enzymatic degradation.
When a dispersant is used, the dispersant can remain on the toner particle surface.

Furthermore, in order to lower the viscosity of the oil phase containing the toner composition, a solvent in which a polyester such as urea-modified polyester or prepolymer (A) is soluble can be used. The use of a solvent is preferable in that the particle size distribution becomes sharp.
The solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal. Examples of the solvent include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, Methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable. The usage-amount of the solvent with respect to 100 parts of prepolymers (A) is 0-300 parts normally, Preferably it is 0-100 parts, More preferably, it is 25-70 parts. When a solvent is used, the solvent (solvent) is removed from the resultant reaction product under normal pressure or reduced pressure after the extension and / or crosslinking reaction of the modified polyester (prepolymer) with an amine.

  The elongation and / or cross-linking reaction time is selected, for example, depending on the reactivity of the isocyanate group structure of the prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. It's time. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate. In addition, as an extender and / or a crosslinking agent, the above-described amines (B) are used.

  In the present invention, prior to desolvation from the dispersion (reaction liquid) after the elongation and / or cross-linking reaction, the dispersion is stirred and converged in a certain temperature range lower than the resin glass transition temperature and in the organic solvent concentration range. It is preferable to remove the solvent at 10 to 50 ° C. after preparing the coalesced particles and confirming the shape. The toner is deformed by liquid agitation before the removal of the solvent. Since this condition is not an absolute condition, it is necessary to appropriately select the condition. When the concentration of the organic solvent contained in the granulation is high, the viscosity of the emulsion is lowered, and when the droplets are united, the particle shape tends to be spherical. Further, when the concentration of the organic solvent contained in the granulation is low, when the droplets coalesce, the viscosity of the droplets is high and the particles do not become complete particles but come off. For this reason, it is necessary to set an optimum condition, and the toner shape can be appropriately adjusted by selecting a condition. Further, the shape can be adjusted by the content of the organically modified inorganic mineral. The organically modified inorganic mineral is preferably contained in an amount of 0.05 to 10% by mass, and more preferably 0.05 to 5% by mass in the solid content in the solution or dispersion. If it is less than 0.05% by mass, the target oil phase viscosity cannot be obtained, and the target shape cannot be obtained. Since the droplet viscosity is low, even if the droplets coalesce during the stirring and converging, the target coalesced particles cannot be obtained, resulting in a spherical shape. If it exceeds 10% by mass, the manufacturability deteriorates, the droplet viscosity becomes too high, the particles do not become coalesced particles, and the fixing performance further deteriorates.

  On the other hand, the ratio Dv / Dn between the volume average particle diameter (Dv) and the number average diameter (Dn) of the toner mainly adjusts, for example, the water phase viscosity, the oil phase viscosity, the characteristics of the resin fine particles, and the addition amount. Can be controlled. Further, Dv and Dn can be controlled by adjusting, for example, characteristics of resin fine particles, addition amount, and the like.

  The toner of the present invention can be used as a two-component developer. In this case, it may be used by mixing with a magnetic carrier, and the content ratio of the carrier and the toner in the developer is preferably 1 to 10 parts by weight of toner with respect to 100 parts by weight of the carrier. 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. Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene acrylic copolymer resins, Halogenated olefin resins such as vinyl, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoro Propylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride And fluoro such as terpolymers of non-fluoride monomers including, and silicone resins. Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance.

The image forming method of the present invention includes an electrostatic latent image forming process (charging process and exposure process), a developing process, a transfer process, a fixing process, and a cleaning process. You may further have processes, such as a process and a control process.
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the image carrier. The material, shape, structure, size and the like of the image carrier can be appropriately selected from known ones. Examples of the material include inorganic substances such as amorphous silicon and selenium, and organic substances such as polysilane and phthalopolymethine. Amorphous silicon is preferable because of its long life. Further, the shape is preferably a drum shape. The electrostatic latent image can be formed by uniformly charging the surface of the image carrier and then exposing it imagewise, and can be performed by an electrostatic latent image forming unit. The electrostatic latent image forming unit preferably has a charger (charging unit) that uniformly charges the surface of the image carrier and an exposure unit (exposure unit) that exposes the surface of the image carrier.

Charging can be performed by applying a voltage to the surface of the image carrier using a charger. The charger can be appropriately selected according to the purpose, but a known contact charger equipped with a conductive or semiconductive roll, brush, film, rubber blade, etc., or corona discharge such as corotron or scorotron is used. Non-contact chargers and the like.
The exposure can be performed by exposing the surface of the image carrier using an exposure device. The exposure device can be appropriately selected according to the purpose, but various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used. It should be noted that an optical back side system in which exposure is performed from the back side of the image carrier may be adopted.

  The development step is a step of forming a visible image by developing the electrostatic latent image using the toner of the present invention. The visible image can be formed using a developing unit. The developing means can be appropriately selected from known ones, and preferably has a developing unit that accommodates the toner of the present invention and can apply the toner to the electrostatic latent image in a contact or non-contact manner. The developing device may be a dry development system or a wet development system. Further, it may be a single color developer or a multicolor developer. Specifically, a stirrer for charging the developer by friction stirring and a developer having a rotatable magnet roller can be used. The developer accommodated in the developing device is a developer using the toner of the present invention, but may be a one-component developer or a two-component developer.

  In a developing device having a two-component developer, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the image carrier, a part of the toner constituting the magnetic brush formed on the surface of the magnet roller moves to the surface of the image carrier by an electric attractive force. As a result, the electrostatic latent image is developed with toner, and a visible image is formed with toner on the surface of the image carrier.

The transfer step is a step of transferring a visible image to a recording medium. The intermediate transfer member is used to primarily transfer the visible image onto the intermediate transfer member, and then the secondary transfer of the visible image onto the recording medium. It is preferable. At this time, the toner used is usually two or more colors, and it is preferable to use a full-color toner. For this reason, it is more preferable to have a primary transfer process in which a visible image is transferred onto an intermediate transfer member to form a composite transfer image, and a secondary transfer process in which the composite transfer image is transferred onto a recording medium.
The transfer can be performed by charging the image carrier using a transfer unit. The transfer means preferably has a primary transfer means for transferring a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium. The intermediate transfer member can be appropriately selected from known transfer members according to the purpose, and a transfer belt or the like can be used.

  The transfer means preferably has a transfer device that peels and charges the visible image formed on the image carrier to the recording medium side. There may be one transfer means or a plurality of transfer means. Specific examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device. The recording medium can be appropriately selected from known recording media, and recording paper or the like can be used.

  The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing unit, and may be fixed each time the toner of each color is transferred to the recording medium, or each color toner is laminated. You may fix at once in the state. The fixing unit can be appropriately selected according to the purpose, but a known heating and pressing unit can be used. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt. The heating in the heating and pressurizing means is usually preferably 80 ° C to 200 ° C. A known optical fixing device may be used together with or instead of the fixing unit depending on the purpose.

The neutralization step is a step of neutralizing by applying a neutralization bias to the image carrier, and can be performed using a neutralization unit. The neutralization means can be appropriately selected from known neutralizers, and a neutralization lamp or the like can be used.
The cleaning step is a step of removing toner remaining on the image carrier, and can be performed using a cleaning unit. The cleaning means can be appropriately selected from known cleaners, and a magnetic brush cleaner, electrostatic brush cleaner, magnetic roller cleaner, blade cleaner, brush cleaner, web cleaner, or the like can be used. It is preferable to use a blade cleaner.

The recycling process is a process in which the toner removed in the cleaning process is recycled by the developing unit, and can be performed using the recycling unit. The recycling means can be appropriately selected according to the purpose, and a known conveying means or the like can be used.
A control process is a process of controlling each process, and can be performed using a control means. The control means can be appropriately selected according to the purpose, and devices such as a sequencer and a computer can be used.

  The process cartridge of the present invention is used in the image forming apparatus of the present invention, and integrally supports an image carrier and at least one unit selected from a charging unit, a developing unit, and a cleaning unit to form the image of the present invention. It is detachable from the main body.

  FIG. 1 shows an example of an image forming apparatus using the image forming method of the present invention. The image forming apparatus 100A includes a drum-shaped photosensitive member 10 as an image carrier, a charging roller 20 as a charging unit, an exposure device 30 as an exposure unit, a developing device 40 as a developing unit, and an intermediate transfer member 50. And a cleaning device 60 as a cleaning means and a static elimination lamp 70 as a static elimination means.

  The intermediate transfer member 50 is an endless belt, and is stretched by three rollers 51 so as to be movable in the direction of the arrow. Part of the three rollers 51 also functions as a transfer bias roller that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer member 50. A cleaning device 90 having a cleaning blade is disposed in the vicinity of the intermediate transfer member 50. In addition, a transfer roller 80 serving as a transfer unit capable of applying a transfer bias for transferring (secondary transfer) a visible image (toner image) to a recording sheet 95 serving as a recording medium is disposed to face the recording paper 95. . Around the intermediate transfer member 50, a corona charger 58 for applying a charge to the toner image on the intermediate transfer member 50 is in contact with the photosensitive member 10 and the intermediate transfer member 50 in the rotation direction of the intermediate transfer member 50. And the contact portion between the intermediate transfer member 50 and the recording paper 95.

  The developing device 40 includes a developing belt 41 as a developer carrying member, and a black developing device 45K, a yellow developing device 45Y, a magenta developing device 45M, and a cyan developing device 45C provided around the developing belt 41. The black developing device 45K includes a developer accommodating portion 42K, a developer supplying roller 43K, and a developing roller 44K. The yellow developing device 45Y includes a developer accommodating portion 42Y, a developer supplying roller 43Y, and a developing roller 44Y. The magenta developer 45M includes a developer container 42M, a developer supply roller 43M, and a developer roller 44M. The cyan developer 45C includes a developer container 42C, the developer supply roller 43C, and a developer. A roller 44C is provided. The developing belt 41 is an endless belt, is stretched by a plurality of belt rollers so as to be movable in the direction of the arrow, and a part of the developing belt 41 is in contact with the photoreceptor 10.

  In the image forming apparatus 100A, the charging roller 20 uniformly charges the photoconductor 10, and then exposes the photoconductor 10 using the exposure device 30 to form an electrostatic latent image. Next, the electrostatic latent image formed on the photoreceptor 10 is developed by supplying a developer from the developing device 40 to form a toner image. Further, the toner image is transferred (primary transfer) onto the intermediate transfer member 50 by the voltage applied by the roller 51, and further transferred (secondary transfer) onto the recording paper 95. As a result, a transfer image is formed on the recording paper 95. The toner remaining on the photoconductor 10 is removed by a cleaning device 60 having a cleaning blade, and the charged charge on the photoconductor 10 is removed by a static elimination lamp 70.

  FIG. 2 shows another example of the image forming apparatus used in the present invention. The image forming apparatus 100B does not include the developing belt 41, except that a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C are arranged around the photoconductor 10 so as to face each other. It has the same configuration as that of the image forming apparatus 100A and exhibits the same function and effect.

  FIG. 3 shows another example of the image forming apparatus used in the present invention. The image forming apparatus 100C is a tandem color image forming apparatus. The image forming apparatus 100 </ b> C includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder 400. The copying apparatus main body 150 is provided with an endless belt-like intermediate transfer member 50 at the center. The intermediate transfer member 50 is stretched around the support rollers 14, 15 and 16 so as to be able to move clockwise in the drawing. An intermediate transfer body cleaning device 17 for removing toner remaining on the intermediate transfer body 50 is disposed in the vicinity of the support roller 15. The intermediate transfer member 50 stretched by the support rollers 14 and 15 is provided with a tandem developing device in which image forming means 18 of four colors of yellow, cyan, magenta, and black are opposed to each other along the conveying direction. 120 is arranged. An exposure device 21 is disposed in the vicinity of the tandem developing device 120. A secondary transfer device 22 is disposed on the side of the intermediate transfer member 50 opposite to the side on which the tandem developing device 120 is disposed. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched around a pair of rollers 23, and the recording paper conveyed on the secondary transfer belt 24 and the intermediate transfer member 50 can contact each other. It is. A fixing device 25 is disposed in the vicinity of the secondary transfer device 22. The fixing device 25 includes a fixing belt 26 that is an endless belt, and a pressure roller 27 that is pressed against the fixing belt 26.

  In the image forming apparatus 100C, a sheet reversing device 28 for reversing the transfer paper is disposed in the vicinity of the secondary transfer device 22 and the fixing device 25. Thereby, images can be formed on both sides of the recording paper.

  Next, formation of a full-color image (color copy) using the tandem developing device 120 will be described. First, a document is set on the document table 130 of the automatic document feeder 400, or the automatic document feeder 400 is opened to set a document on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed.

  When a start switch (not shown) is pressed, when an original is set on the automatic document feeder 400, after the original is conveyed onto the contact glass 32, on the other hand, when an original is set on the contact glass 32, Immediately, the scanner 300 is driven, and the first traveling body 33 and the second traveling body 34 travel. At this time, the reflected light from the original surface of the light irradiated by the first traveling body 33 is reflected by the mirror in the second traveling body 34 and is received by the reading sensor 36 through the imaging lens 35. As a result, a color original (color image) is read and used as image information for each color of black, yellow, magenta, and cyan. The image information of each color is transmitted to the image forming means 18 of each color in the tandem developing device 120, and a toner image of each color is formed.

  The toner image on the black photoconductor 10K, the toner image on the yellow photoconductor 10Y, the toner image on the magenta photoconductor 10M, and the toner image on the cyan photoconductor 10C are sequentially transferred onto the intermediate transfer member 50. (Primary transfer). Then, the toner images of the respective colors are superimposed on the intermediate transfer member 50 to form a composite color image (color transfer image).

  As shown in FIG. 4, the image forming means 18 for each color in the tandem developing device 120 includes a photosensitive member 10, a charger 59 for uniformly charging the photosensitive member 10, and a photosensitive device based on image information of each color. By exposing the body 10 (L in the figure), an exposure device 21 that forms an electrostatic latent image on the photoreceptor 10, and developing the electrostatic latent image using toner of each color, the photoreceptor 10 A developing device 61 that forms toner images of the respective colors, a transfer charger 62 that transfers the toner images of the respective colors onto the intermediate transfer member 50, a photoconductor cleaning device 63, and a static eliminator 64 are provided.

  On the other hand, in the paper feed table 200, one of the paper feed rollers 142a is selectively rotated to feed recording paper from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143, and one sheet at a time by the separation roller 145a. The paper is separated and sent to the paper feed path 146, transported by the transport roller 147, guided to the paper feed path 148 in the copying machine main body 150, and abutted against the registration roller 49 to stop. Alternatively, the paper feed roller 142b is rotated to feed out the recording paper on the manual feed tray 52, separated one by one by the separation roller 145b, put into the manual feed path 53, and abutted against the registration roller 49 and stopped. The registration roller 49 is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet.

  Then, the registration roller 49 is rotated in time with the color transfer image formed on the intermediate transfer member 50, and the recording paper is fed between the intermediate transfer member 50 and the secondary transfer device 22, thereby being recorded on the recording paper. A color transfer image is formed. The toner remaining on the intermediate transfer member 50 after the transfer is cleaned by the intermediate transfer member cleaning device 17.

  The recording paper on which the color transfer image is formed is conveyed to the fixing device 25 by the secondary transfer device 22, and the color transfer image is fixed on the recording paper by heat and pressure. Thereafter, the recording paper is switched by the switching claw 55 and discharged by the discharge roller 56 and is stacked on the discharge tray 57. Alternatively, the sheet is switched by the switching claw 55, reversed by the sheet reversing device 28, led to the transfer position again, and after the image is formed on the back surface, the sheet is discharged by the discharge roller 56 and stacked on the discharge tray 57.

The process cartridge of the present invention is used in the image forming apparatus of the present invention, and integrally supports an image carrier and at least one means selected from a charging device, a developing device, and a cleaning device, and is attached to the image forming apparatus main body. It is detachable.
FIG. 6 shows a schematic configuration of a process cartridge having the toner of the present invention.
In FIG. 6, 1 indicates the entire process cartridge, 2 indicates a photosensitive member, 3 indicates a charging unit, 4 indicates a developing unit, and 5 indicates a cleaning unit.
In the present invention, a plurality of components such as the photosensitive member 2, the charging device unit 3, the developing unit 4, the cleaning unit 5 and the like described above are integrally coupled as a process cartridge. The process cartridge is configured to be detachable from the image forming apparatus main body such as a copying machine or a printer.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to this. In the following description, parts indicate parts by mass.

The following lubricant particles were used.
A zinc stearate with a primary particle size of 100 nm B zinc stearate with a primary particle size of 300 nm C zinc stearate with a primary particle size of 500 nm

The inorganic fine particles dispersed and fixed in the lubricant particles were hydrophobic silica fine particles having a BET specific surface area of 140 m ² / g and a hydrophobization degree of 71%.

The following external additives were used.
Hydrophobic silica fine particles having a BET specific surface area of 140 m ² / g and a hydrophobization degree of 71%
II Hydrophobic titanium oxide fine particles with a BET specific surface area of 68 m ² / g and a hydrophobization degree of 61%
III Hydrophobic silica fine particles with a BET specific surface area of 35 m ² / g and a hydrophobization degree of 76%

[Example 1]
A method for producing the toner used in this example will be described.
(Synthesis of unmodified polyester resin)
229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propion oxide 3-mole adduct, 208 parts of terephthalic acid, 46 parts of adipic acid and dibutyltin oxide 2 parts were added and reacted at 230 ° C. under normal pressure for 8 hours. Next, after reacting under reduced pressure of 10 to 15 mmHg for 5 hours, 44 parts of trimellitic anhydride was added to the reaction vessel, and reacted at 180 ° C. for 2 hours under normal pressure to obtain an unmodified polyester resin (1). Was synthesized.
The obtained unmodified polyester resin had a number average molecular weight of 2500, a weight average molecular weight of 6700, a glass transition temperature of 43 ° C., and an acid value of 25 mgKOH / g.

(Master batch manufacturing method)
1200 parts of water, 540 parts of carbon black Printex 35 (manufactured by Dexa; DBP oil absorption = 42 ml / 100 mg, pH = 9.5) and 1200 parts of unmodified polyester resin (1) were used using a Henschel mixer (manufactured by Mitsui Mining). And mixed. The resulting mixture was kneaded at 150 ° C. for 30 minutes using two rolls, then rolled and cooled, and pulverized with a pulverizer (manufactured by Hosokawa Micron Corporation) to prepare a master batch (1).

(Preparation of wax dispersion)
In a reaction vessel equipped with a stirring bar and a thermometer, 378 parts of unmodified polyester resin (1), 110 parts of carnauba wax, 22 parts of salicylic acid metal complex E-84 (manufactured by Orient Chemical Co., Ltd.) and 947 parts of ethyl acetate are charged. The mixture was heated to 80 ° C. with stirring, held at 80 ° C. for 5 hours, and then cooled to 30 ° C. over 1 hour. Next, 500 parts of master batch (1) and 500 parts of ethyl acetate were charged into the reaction vessel and mixed for 1 hour to obtain a raw material solution (1).
1324 parts of the obtained raw material solution (1) was transferred to a reaction vessel, filled with 80% by volume of 0.5 mm zirconia beads using an ultra visco mill (manufactured by Imex Co., Ltd.), a bead mill, and the liquid feeding speed was 1 kg / hour. The carnauba wax was dispersed in three passes under the condition of the disk peripheral speed of 6 m / sec to obtain a wax dispersion (1).

(Preparation of toner material dispersion)
Next, 1324 parts of a 65 mass% ethyl acetate solution of the unmodified polyester resin (1) was added to the wax dispersion (1). A layered inorganic mineral montmorillonite (Clayton APA Southern Clay modified at least partly with a quaternary ammonium salt having a benzyl group) was added to 200 parts of a dispersion obtained by one pass using Ultraviscomyl under the same conditions as above. (Products) 1.0 part was added. K. Using a homodisper (manufactured by Tokushu Kika Kogyo Co., Ltd.), the mixture was stirred for 30 minutes to obtain a toner material dispersion (1).

(Synthesis of intermediate polyester resin)
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, 22 parts of trimellitic anhydride And 2 parts of dibutyltin oxide were added and reacted at 230 ° C. for 8 hours under normal pressure. Next, it was made to react under reduced pressure of 10-15mHg for 5 hours, and the intermediate polyester resin was synthesize | combined.
The obtained intermediate polyester resin had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, a glass transition temperature of 55 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl value of 51 mgKOH / g.

(Prepolymer synthesis)
Next, 410 parts of the intermediate polyester resin, 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are charged into a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. (1) was synthesized. The free isocyanate content of the obtained prepolymer was 1.53% by mass.

(Preparation of oil phase mixture)
In a reaction vessel equipped with a stir bar and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to synthesize a ketimine compound. The amine value of the obtained ketimine compound was 418 mgKOH / g.
In a reaction container, 749 parts of a dispersion of toner material (1), 115 parts of prepolymer (1) and 2.9 parts of a ketimine compound are charged, and a TK homomixer (manufactured by Tokushu Kika) is used at 5000 rpm for 1 minute. By mixing, an oil phase liquid mixture (1) was obtained.

(Polymerization of resin particle dispersion)
In a reaction vessel equipped with a stirring bar and a thermometer, 683 parts of water, 11 parts of reactive emulsifier (sodium salt of sulfuric acid ester of methacrylic acid ethylene oxide adduct), Eleminol RS-30 (manufactured by Sanyo Chemical Industries), styrene 83 Parts, 83 parts of methacrylic acid, 110 parts of butyl acrylate and 1 part of ammonium persulfate were stirred at 400 rpm for 15 minutes to obtain an emulsion. The emulsion was heated, heated to 75 ° C. and reacted for 5 hours. Next, 30 parts of a 1% by mass ammonium persulfate aqueous solution was added and aged at 75 ° C. for 5 hours to prepare a resin particle dispersion.

(Preparation of emulsified slurry)
990 parts of water, 83 parts of resin particle dispersion, 37 parts of 48.5% by weight aqueous solution of dodecyl diphenyl ether disulfonate, Eleminol MON-7 (manufactured by Sanyo Chemical Industries), 1% by weight aqueous solution of sodium carboxymethylcellulose polymer dispersant 135 parts of BS-H-3 (Daiichi Kogyo Seiyaku Co., Ltd.) and 90 parts of ethyl acetate were mixed and stirred to obtain an aqueous medium.
To 1200 parts of the aqueous medium, 867 parts of the oil phase mixed liquid (1) was added and mixed at 13000 rpm for 20 minutes using a TK homomixer to prepare a dispersion (emulsion slurry (1)).
Next, the emulsified slurry (1) is charged into a reaction vessel equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging is performed at 45 ° C. for 4 hours to obtain a dispersed slurry (1). It was.

The volume average particle diameter (Dv) and the number average particle diameter (Dn) of the toner of the present invention are measured with a particle size measuring device (“Multisizer III”, manufactured by Beckman Coulter, Inc.) at an aperture diameter of 100 μm, and analysis software ( The analysis was performed with a Beckman Coulter Multisizer 3 Version 3.51). Specifically, 0.5 ml of 10 wt% surfactant (alkylbenzene sulfonate Neogen SC-A; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added to a glass 100 ml beaker, 0.5 g of each toner was added, and the mixture was stirred with a micropartel. Subsequently, 80 ml of ion-exchanged water was added. The obtained dispersion was subjected to a dispersion treatment for 10 minutes with an ultrasonic disperser (W-113MK-II, manufactured by Honda Electronics Co., Ltd.). The dispersion was measured using the Multisizer III and Isoton III (manufactured by Beckman Coulter) as the measurement solution. In the measurement, the toner sample dispersion was dropped so that the concentration indicated by the apparatus was 8 ± 2%. In this measurement method, it is important to adjust the concentration to 8 ± 2% from the viewpoint of the reproducibility of the particle size. Within this concentration range, no error occurs in the particle size.
The volume average particle diameter (Dv) and number average particle diameter (Dn) of the toner can be measured using the above-mentioned Coulter Counter TA-II or Coulter Multisizer II. It is preferable to measure.

After 100 parts by mass of the dispersion slurry was filtered under reduced pressure, 100 parts of ion-exchanged water was added to the filter cake, mixed at 12000 rpm for 10 minutes using a TK homomixer, and then filtered.
To the obtained filter cake, 10% by mass hydrochloric acid was added to adjust the pH to 2.8, and the mixture was mixed for 10 minutes at 12,000 rpm using a TK homomixer, followed by filtration.
Furthermore, 300 parts of ion-exchanged water was added to the obtained filter cake, mixed for 10 minutes at 12000 rpm using a TK homomixer, and then filtered twice to obtain a final filter cake.
The obtained final filter cake was dried at 45 ° C. for 48 hours using an air circulation dryer, and sieved with an opening of 75 μm mesh to obtain a base toner.

Next, 100 parts by mass of the lubricant particles A, 10 parts by mass of hydrophobic silica fine particles having a BET specific surface area of 140 m ² / g and a hydrophobization degree of 71% were added to a multipurpose mixer MP5 type (Mitsui Mining Co., Ltd.) and Q type (spherical type). In a device equipped with a tank, mixing was performed at a feather speed of 5000 rpm for 1 minute to obtain composite fine particles composed of inorganic fine particles and a lubricant.
Next, 100 parts by mass of the base toner and 2 parts by mass of the composite fine particles were mixed with a 2 L Henschel mixer for 2 minutes at a peripheral speed of 20 m / s, and then external additives I, II, and III were each added in an amount of 1 part by mass. Mixed for 4 minutes at a speed of 33 m / s. The above was air sieved with a 500 mesh sieve to obtain a toner.

The image of the produced toner was evaluated by the following method.
Image evaluation All toners and devices used for evaluation are left in an environment room at 25 ° C. and 50% for one day.
2. All the toner on the PCU of the image forming apparatus A (non-contact AC charging, charging AC frequency 7.3 cycle / mm, photosensitive member linear velocity 250 mm / sec, blade-shaped cleaning member) is removed, and only the carrier remains in the developing device. .
3. 28 g of black toner serving as a sample is put into a developing device having only a carrier, and 400 g of a developer having a toner concentration of 7% is prepared.
4). The developing device is mounted on the image forming apparatus main body, and only the developing device is idled for 5 minutes at a developing sleeve linear velocity of 300 mm / s.
5). Both the developing sleeve and the photoconductor were rotated by trailing at a target linear velocity, and the charging potential and the developing bias were adjusted so that the toner on the photoconductor was 0.6 ± 0.05 mg / cm ² .
6). The cleaning blade was only one cleaning blade mounted on a commercially available Imagio neo C600 PCU, its elastic modulus was 70%, the thickness was 2 mm, and the contact angle with the image carrier at the counter was 20 °.
7). Under the above development conditions, the transfer current is adjusted so that the transfer rate is 96 ± 2%.
8). Using the above set values, 1000 charts (FIG. 5) with a 4 cm band in the sheet passing direction and a 25 cm band in the sheet passing width direction were output.
9. The 10th and 1000th images were ranked by visual evaluation.

[Example 2]
A toner was prepared and evaluated in the same manner as in Example 1 except that the composite fine particle lubricant particle A in Example 1 was changed to the lubricant particle B.
[Example 3]
A toner was prepared and evaluated in the same manner as in Example 1 except that the composite fine particle lubricant particle A in Example 1 was changed to the lubricant particle C.
[Example 4]
In Example 1, except that 100 parts by mass of the base toner, 2 parts by mass of the composite fine particles and 1 part by mass of the external additives I, II, and III were simultaneously added and mixed at a peripheral speed of 33 m / s for 4 minutes. A toner was prepared in the same manner as in Example 1.
[Example 5]
In Example 1, 100 parts by weight of the base toner and 1 part by weight of each of the external additives I, II, and III were simultaneously added and mixed at a peripheral speed of 33 m / s for 4 minutes. A toner was prepared in the same manner as in Example 1 except that the mixing was performed at a speed of 20 m / s for 2 minutes.
[Example 6]
In Example 1, 100 parts by mass of the lubricant particles A, 10 parts by mass of hydrophobic silica fine particles having a BET specific surface area of 140 m ² / g and a hydrophobization degree of 71% were added to a blade peripheral speed with a 2 L Henschel mixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). A toner was prepared in the same manner as in Example 1 except that composite fine particles composed of inorganic fine particles and a lubricant were obtained by mixing at 5425 rpm for 2 minutes.

[Comparative Example 1]
A toner was prepared and evaluated in the same manner as in Example 1 except that the composite fine particles in Example 1 were only the hydrophobic silica fine particles without using the lubricant particles A.
[Comparative Example 2]
In Comparative Example 1, evaluation was performed in the same manner as in Comparative Example 1 except that the image forming apparatus was changed to Image Forming Apparatus B (charging AC frequency 9.1 cycle / mm, photosensitive member linear velocity 230 mm / sec).
[Comparative Example 3]
In Example 1, 1 part by mass of each of external additives I, II, III and lubricant particles A was added to the base toner particles, mixed at a peripheral speed of 33 m / s for 4 minutes, and then air sieved through a 500 mesh sieve. A toner was prepared and evaluated in the same manner as in Example 1 except that the toner was prepared.

[Example 7]
-Preparation of toner base particles-
After adding 80 parts by mass of the unmodified polyester resin (1), 5 parts of paraffin wax (HNP-9 melting point 75 ° C. by Nippon Seiki Co., Ltd.) and 10 parts of the master batch (1), the mixture is sufficiently stirred and mixed in a Henschel mixer. The mixture was heated and melted at 130 ° C. for 30 minutes using a roll mill, further cooled to room temperature, and the obtained kneaded material was coarsely pulverized to 200 to 400 μm using a hammer mill. Next, a finely pulverized apparatus that directly pulverizes the coarsely pulverized product against the impingement plate using a jet stream, and a finely pulverized powder obtained by the finely pulverized apparatus forms a swirl flow in the classification chamber, and Crushing and classification were performed using an IDS-2 type pulverizing and classifying apparatus (manufactured by Nippon Pneumatic Industry Co., Ltd.) integrally having an air classifier that was separated by centrifugation, and toner base particles were obtained after classification.
Next, 100 parts by mass of the lubricant particles A, 10 parts by mass of hydrophobic silica fine particles having a BET specific surface area of 140 m ² / g and a hydrophobization degree of 71% were added to a multipurpose mixer MP5 type (Mitsui Mining Co., Ltd.) and Q type (spherical type). In a device equipped with a tank, mixing was performed at a feather speed of 5000 rpm for 1 minute to obtain composite fine particles composed of inorganic fine particles and a lubricant.
Next, 100 parts by mass of the base toner and 2 parts by mass of the composite fine particles were mixed with a 2 L Henschel mixer for 2 minutes at a peripheral speed of 20 m / s, and then external additives I, II, and III were each added in an amount of 1 part by mass. Mixed for 4 minutes at a speed of 33 m / s. The above was air sieved with a 500 mesh sieve to obtain a toner. Evaluation was performed in the same manner as in Example 1.

Table 1 shows the results obtained from the image evaluation.
The image quality is expressed in the order of ◎, ○, △, and ×.
The image quality is based on the following.
A: There is no image unevenness, blur, or vertical stripe at all, and the image is good.
○: Some image unevenness, blurring, and vertical stripes are observed, but there are few problems.
Δ: Image unevenness, blurring, and vertical stripes are relatively large, which causes a problem as an image.
×: Image unevenness, blurring, and vertical stripes are very large, which causes a problem as an image.

DESCRIPTION OF SYMBOLS 1 Process cartridge 2 Photoconductor 3 Charging means 4 Developing means 5 Cleaning means 10 Photoconductor (image carrier)
10K black photoconductor 10Y yellow photoconductor 10M magenta photoconductor 10C cyan photoconductor 14, 15, 16 support roller 17 intermediate transfer body cleaning device 18 image forming means 20 charging roller 21 exposure device 22 secondary transfer device 23 roller 24 secondary transfer belt 25 fixing device 26 fixing belt 27 pressure belt 28 sheet reversing device 30 exposure device 32 contact glass 33 first traveling body 34 second traveling body 35 imaging lens 36 reading sensor 40 developing device 41 developing belt 42K, 42Y, 42M, 42C Developer container 43K, 43Y, 43M, 43C Developer supply roller 44K, 44Y, 44M, 44C Developer roller 45K Black developer 45Y Yellow developer 45M Magenta developer 45C Cyan developer 49 Les Stroller 50 the intermediate transfer member 51 roller 52 bypass tray 53 Bypass paper feed path 55 switching claw 56 discharge rollers 57 discharge tray 58 corona charger 59 charger 60 the cleaning device (cleaning blade)
61 Developing Device 62 Transfer Charging Device 63 Photoconductor Cleaning Device 64 Static Eliminator 70 Static Eliminating Lamp 80 Transfer Roller 90 Cleaning Device 95 Recording Paper 100A, 100B, 100C Image Forming Device 110 Belt Type Fixing Device 120 Tandem Type Developer 130 Document Base 142a, 142b paper feed roller 143 paper bank 144 paper feed cassette 145a, 145b separation roller 146 paper feed path 147 transport roller 148 paper feed path 150 copying apparatus main body 200 paper feed table 300 scanner 400 automatic document transport apparatus

Japanese Patent Laid-Open No. 2004-246057 JP 2006-221077 A

Claims (9)

  A toner obtained by externally adding an external additive to a base toner comprising at least a resin and a colorant, wherein the toner contains at least composite fine particles comprising inorganic fine particles and a lubricant.   The toner according to claim 1, wherein the composite fine particles are obtained by dispersing or fixing inorganic fine particles on a lubricant surface.   The toner according to claim 1, wherein the composite fine particles are formed by externally mixing inorganic fine particles with a lubricant, and the composite fine particles are externally added to the base toner.   The toner according to claim 1, wherein a primary particle diameter of the lubricant is 80 nm to 500 nm. The toner according to claim 1, wherein the inorganic fine particles have a hydrophobicity of 50 to 90% and a BET specific surface area of 100 to 300 m ² / g.   The toner according to claim 1, wherein the toner has a layered inorganic mineral obtained by modifying at least a part of ions between layers of the layered inorganic mineral with an organic ion.   The base toner is obtained by dispersing and / or emulsifying an oil phase containing a toner composition containing at least a binder resin and / or a binder resin precursor and a colorant in an aqueous medium, and granulating it. 7. The toner according to claim 6, wherein the toner composition comprises a layered inorganic mineral obtained by modifying at least a part of ions between layers of the layered inorganic mineral with organic ions. An image carrier, a charging step for charging the surface of the image carrier, an exposure step for writing a latent image by exposure on the image carrier, and developing the latent image written on the image carrier by developing toner. A developing step for forming a visual image, a transferring step for transferring the visible image to a recording medium or an intermediate transfer member, a fixing step for fixing the transferred image transferred to the recording medium, and an image carrier that has not been transferred completely In the image forming method having at least a cleaning step of cleaning the transfer residual toner above,
In the charging step, the image carrier is charged by non-contact AC charging,
The AC has an AC frequency of 6.5 to 8.5 cycles / mm,
The cleaning step is performed with a blade-shaped cleaning member,
An image forming method, wherein the toner used for image formation is the toner according to claim 1.   In a process cartridge that integrally supports an image carrier and at least one unit selected from a charging unit, a developing unit, and a cleaning unit, and is detachable from the main body of the image forming apparatus, the developing unit uses toner. A process cartridge, wherein the toner is the toner according to claim 1.

Images