JP4368708B2 - Developer, developing device, image forming apparatus, process cartridge - Google Patents

Description

  The present invention relates to a developer composed of a magnetic carrier and toner that develops an electrostatic latent image formed on the surface of a latent image carrier. The present invention also relates to a developing device, an image forming apparatus, and a process cartridge that use the developer.

  In recent years, as the toner used for image formation in the electrostatic copying process, the demand for higher image quality has been increasing, and therefore the particle size and the sphere have been reduced. The reproducibility of dots is improved by reducing the particle size, and the developability and transferability can be improved by making the particles spherical. In the conventional kneading and pulverization method that has been used as a toner production method, it is very difficult to produce such a toner having a small particle size and a spherical shape. Polymerized toner produced by a dispersion polymerization method or the like is being adopted.

However, when a toner having a spherical shape and a reduced particle size is used, there are some problems in cleaning the surface of the photosensitive member as a latent image carrier performed after image formation.
One of them is that it is difficult to clean the toner remaining untransferred on the surface of the photosensitive member by a generally used blade cleaning method. The cleaning blade removes toner while rubbing the surface of the photoconductor, but the edge portion of the cleaning blade is deformed due to frictional resistance with the photoconductor, so that a minute space is generated between the photoconductor and the cleaning blade. The smaller the toner particle size, the easier it is to enter this space. Since the rolling friction force is smaller as the invading toner has a shape close to a spherical shape, it starts to roll in the space between the photosensitive member and the cleaning blade, passes through the cleaning blade, and leads to poor cleaning.

  In order to improve the cleaning performance, the cleaning means side has been improved by increasing the contact pressure of the cleaning blade to the surface of the photoconductor. Sexual problems arise.

  Therefore, proposals have been made to improve the blade cleaning property by making the shape of the toner obtained by the polymerization method irregular. For example, there has been proposed a toner prepared by emulsion polymerization, suspension polymerization or the like, and flattened by applying heat and mechanical shearing force to spherical resin particles (see, for example, Patent Document 1). This toner is a flat toner having a volume average particle diameter d of 4 to 10 μm and a ratio of d to the thickness t of toner particles (d / t, flatness) of 2 to 5. By forming the toner in such a shape, it is said that even if the toner has a small particle size, it is possible to prevent the toner remaining on the surface of the photoreceptor from slipping through and the toner filming on the surface of the photoreceptor. .

  However, when the deformed toner as described above is mixed with a magnetic carrier to form a two-component developer, and an image is formed using a developing device for developing an electrostatic image, the following problems occur. For example, a background stain occurs when a high area ratio image is continuously output after a low area ratio image is output. As a result of studies by the present inventors, it was considered that this background stain was caused by the fact that the toner supply in the developing device was not normally performed.

  FIG. 3 is a schematic configuration diagram of a two-component developing device. A developing container 401 of the developing device 4 contains a developer composed of toner and a magnetic carrier. The developing container 401 is provided with an opening at a position facing the photoconductor 40, and a developing sleeve 402 having a magnetic field generating means inside is provided in the opening with a predetermined gap from the photoconductor 40. A layer thickness regulating member 406 that regulates the layer thickness of the developer carried on the developing sleeve 402 is provided above the developing sleeve 402. Further, stirring screws 403 and 404 are provided below the developing sleeve 402 of the developing container 401 so as to convey the developer to the developing sleeve 402 side while stirring.

  A toner concentration sensor 405 is provided at the bottom of the developing container 401. This toner concentration sensor 405 detects the apparent magnetic permeability of a fixed volume of developer in the vicinity of the sensor, detects the toner concentration in the developer from the change in the magnetic permeability, that is, the ratio between the toner and the magnetic carrier, Adjust the toner supply amount. For example, if the value of the magnetic permeability detected by the toner concentration sensor 405 increases, it means that the toner in the developer has decreased, and therefore, toner supply from a toner bottle (not shown) is started. Conversely, when the value of the magnetic permeability detected by the toner concentration sensor 405 is small, it means that the toner in the developer has increased, and thus the toner supply is stopped.

However, in the case of the toner concentration sensor as described above, when the bulk density of the developer in the developer container 401 changes due to some influence, the apparent magnetic permeability of the developer also changes, so the toner concentration in the developer changes. Even if it is not, a situation occurs in which the sensor output changes. For example, when the bulk density of the developer decreases, even if the toner concentration in the developer is constant, the apparent permeability of the developer increases, so that an output indicating that the toner has decreased is made and the toner is replenished Will be. As a result, the actual toner concentration in the developer becomes higher than the set value, causing an abnormal image such as a background stain.
The problems such as the background stain generated by the developer containing the deformed toner described above are considered to be caused by the fact that the toner in the developing device is not normally supplied. That is, when a low area ratio image is output as described above, the amount of toner consumed is small, and thus the residence time of the developer in the developing container 401 becomes long. For this reason, it is considered that the bulk density changes due to damage to the developer due to the stirring share in the developing container 401.

  As described above, the present inventors have revealed that the background smearing phenomenon caused by excessive toner replenishment due to the change in the bulk density of the developer is particularly remarkable when toner having a large flatness is used. It became. Therefore, it is necessary to find the relationship between the shape of the toner and the change in the bulk density of the developer and solve the above problem.

In order to accurately control the toner density in the developing device container and prevent the occurrence of abnormal images, the use of spherical toner, the use of spherical toner to which inorganic oxide fine particles having a specific shape are externally added, etc. Has been proposed (see, for example, Patent Documents 2 to 4).
However, no proposal has been made for toner that has been deformed from a spherical shape.

JP 2003-131537 A Japanese Patent Laid-Open No. 11-7189 JP 2000-47476 A Japanese Patent Laid-Open No. 11-73005

  In view of the above problems, it is an object of the present invention to provide a two-component developer that exhibits stable toner charging characteristics with little change in the bulk density of the developer even when used for a long time in a developing device. It is another object of the present invention to provide a developing device that accommodates the developer and can control the toner density more accurately. It is another object of the present invention to provide an image forming apparatus that includes the developing device and that can obtain a high-quality image without generating an abnormal image such as a background stain.

In order to solve the above problems, the present invention is characterized by the following.
1. The present invention is a developer for developing an electrostatic latent image formed on a latent image carrier, comprising a toner comprising at least a colorant and a binder resin containing a modified polyester and a magnetic carrier. The toner is obtained by deforming it by applying mechanical shearing force in the liquid, and the flatness (Dv / d) of the toner is 1.2 to 2.0 (where Dv is the volume average particle size of the toner). The diameter d is the average thickness when the toner is viewed from the direction where the projected area is maximized.) The developer has a bulk density change rate of 10% or less.

2. The toner has a loose apparent density of 0.37 g / cm ³ or more.
3. The toner has a volume average particle diameter (Dv) of 3 to 8 μm and a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) of 1.0 to 1.3. It is characterized by that.
4). The toner has an average circularity of 0.930 to 0.965.

5). The toner comprises an oil phase formed by dissolving and / or dispersing a toner composition containing a toner binder component composed of a modified polyester resin capable of reacting with a compound having an active hydrogen group in an organic solvent. A toner obtained by dispersing in a water-based medium to obtain an emulsified dispersion, and subjecting the modified polyester resin to elongation and / or cross-linking reaction with a compound having an active hydrogen group in the emulsified dispersion. .

6). The present invention also relates to a developing device for developing and developing an electrostatic latent image on a latent image carrier by carrying and transporting the developer by the developer carrier and forming an electric field at a position facing the latent image carrier. The developing device uses any one of the above-described developers.
7). The developing device includes a toner concentration detecting unit that detects a change in toner concentration in the developer as a change in magnetic permeability of the developer.

8). The present invention also includes at least a latent image carrier that carries a latent image, and a developing unit that supplies toner to the electrostatic latent image formed on the surface of the latent image carrier to visualize the latent image. In the process cartridge that is supported by the image forming apparatus and is detachably formed on the main body of the image forming apparatus, the developing means is a process cartridge that is any one of the developing devices.

9. Furthermore, the present invention provides a latent image carrier for carrying a latent image, a charging means for uniformly charging the surface of the latent image carrier, and exposing the charged surface of the latent image carrier based on image data. An exposure means for writing an electrostatic latent image, a developing means for supplying toner to the electrostatic latent image formed on the surface of the latent image carrier to make it visible, and a visible image on the surface of the latent image carrier In the image forming apparatus including a transfer unit that transfers the image to the recording member and a fixing unit that fixes the visible image on the recording member, the developing unit is an image forming apparatus that is any one of the developing devices.

  According to the present invention, the change in the bulk density of the developer in the developing device can be reduced, the toner density sensor can be satisfactorily controlled by the toner density sensor, and abnormal images such as scumming due to excessive toner supply are generated. It is possible to provide a developer that is not allowed to occur. By including the toner whose shape is controlled, the blade cleaning performance in the cleaning process can be improved. Furthermore, a high-quality and high-definition image can be provided by a developing device using the developer of the present invention and an image forming apparatus equipped with the developing device.

Hereinafter, embodiments of the present invention will be described.
The developer of the present invention is a two-component developer comprising a toner and a magnetic carrier, and the toner has the following characteristics.
The toner according to the present invention can be obtained by applying a mechanical shearing force in a liquid and making it deformed. Toner particles composed of at least a colorant and a binder resin are dispersed in an aqueous medium, and the toner particles are deformed by applying a mechanical shearing force thereto. The step of deforming will be described in detail later, but may be heated as necessary.

FIG. 1 is a diagram schematically showing the shape of the toner according to the present invention obtained through the above-described deforming step. FIG. 1A is a plan view when the toner is viewed from the direction in which the projected area is maximized, and FIG. 1B is a side sectional view in that state. Thus, the toner has a shape close to a spindle shape from a spherical shape.
Here, as shown in FIG. 1B, when the average thickness of the toner is d, the ratio (Dv / d) of the volume average particle diameter of the toner separately measured to Dv is defined as the flatness of the toner. To do. The flatness (Dv / d) value of the toner according to the present invention is 1.2 to 2.0. If the flatness (Dv / d) is smaller than 1.2, the toner shape is close to a spherical shape, which is not preferable because a defect such as slipping of the cleaning blade occurs in the cleaning process during image formation. On the other hand, toner having a flatness (Dv / d) larger than 2.0 is not preferable because it easily causes a change in the bulk density of the developer.

Incidentally, the average thickness d of the toner shown in FIG. 1 (b) is obtained by using a color leather microscope VK-8500 (manufactured by Keyence Corporation) on 100 toner particles uniformly dispersed and adhered on a smooth measurement surface. The thickness was measured and calculated.
Further, the volume average particle diameter Dv of the toner was measured using a Coulter Counter TA-II (manufactured by Coulter, Inc.) as a measuring device. The measuring method is as follows. First, 0.1 to 5 ml of a surfactant (preferably alkyl benzene sulfonate) is added as a dispersant to 100 to 150 ml of an electrolytic aqueous solution. Here, the electrolytic solution was prepared by preparing approximately 1% NaCl aqueous solution using primary sodium chloride, and ISOTON R-II (manufactured by Coulter Scientific Japan) was used. Further, 2 to 20 mg of a measurement sample was added thereto, suspended in an electrolytic solution, and subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes. Using the measurement apparatus, the volume and number of toner particles in the sample were measured for each channel using a 100 μm aperture as the aperture, and the volume distribution and number distribution of the toner were calculated.
In addition, as a channel, it is 2.00-2.52 micrometer; 2.52-3.17 micrometer; 3.17-4.00 micrometer; 4.00-5.04 micrometer; 5.04-6.35 micrometer; 6.35- 8.00 to 10.08 μm; 10.08 to 12.70 μm; 12.70 to 16.00 μm; 16.00 to 20.20 μm; 20.20 to 25.40 μm; 25.40 to 32. 00 μm; 13 channels from 32.00 to 40.30 μm were used.

The developer of the present invention comprises a toner having the above shape and a magnetic 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, polyhexafluoropropylene resins , Copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinyl fluoride Fluoro such as terpolymers of isopropylidene and a non-fluorinated monomer, and silicone resins. Moreover, you may make conductive powder etc. contain 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 content ratio of the magnetic carrier to the toner in the developer is preferably 1 to 10 parts by weight of the toner with respect to 100 parts by weight of the magnetic carrier.

The developer of the present invention has a bulk density change rate of 10% or less. If the bulk density change rate exceeds 10%, the developability is adversely affected. This is because, in a developing device in which a toner concentration sensor is installed in the developing container, the detection of the toner concentration is not normally performed due to the influence of the change in the bulk density of the developer, which causes a problem in the toner concentration control. Is.
Here, the change rate of the bulk density of the developer simulates the change in the bulk density caused by the share of the developer in the developing device, and is a tumbler mixer (T2F type, manufactured by Shinmaru Enterprises). Is calculated from the following equation (1) from the bulk density (ρ ₀ ) of the initial agent mixed for 2 minutes at medium speed rotation and the bulk density (ρ _a ) of the developer mixed for 30 minutes at high speed rotation: The In addition, ρ ₀ and ρ _a were measured by using a bulk specific gravity meter (manufactured by Kuramochi Scientific Instruments) and gently pouring the developer into a container having a volume of 50 cm ³ , It was determined by measuring the weight.
Bulk density change rate (%) = (| ρ ₀ −ρ _a | ÷ ρ ₀ ) × 100 Formula (1)

As described above, since the flatness (Dv / d) of the toner is 1.2 to 2.0 and the bulk density change rate of the developer is 10% or less, the toner density control in the developer can be accurately controlled. And can provide high quality images.
When the flatness (Dv / d) of the toner is large, it affects the change in the bulk density of the developer. One of the reasons is that the surface properties of the deformed toner particles are externally added to the toner. Such particles are likely to be embedded, and this is considered to be due to the decrease in toner fluidity as a result of embedding the external additive in the toner in response to the share in the developing device.

The loose apparent density of the toner according to the present invention is preferably 0.37 g / cm ³ or more. More preferably, it is in the range of 0.40 to 0.50 g / cm ³ . By setting the toner loose apparent density to 0.37 g / cm ³ or more, the fluidity of the toner can be improved, the chargeability of the toner can be made uniform, and a high-quality image with little unevenness in image density can be obtained. Can do. Further, changes in the bulk density of the developer can be suppressed. On the other hand, when the apparent loose density of the toner is less than 0.37 g / cm ³ , the fluidity of the toner becomes low, so that the toner charge amount is distributed, and the toner tends to cause transfer dust during transfer. In particular, if the apparent loose density of the toner exceeds 0.70 g / cm ³ , the toner fluidity cannot be sufficiently secured, the toner replenishment property, the toner and developer charge rising properties deteriorate, and the image has many uneven image densities. Or cause toner to scatter in the machine.

For the measurement of the apparent density of loose toner, a powder tester (PTN type: manufactured by Hosokawa Micron Corporation) was used, and the toner passed through a mesh with a mesh size of 350 μm was passed through a 100 cm ³ measuring glass cylinder with a 2 cm ³ scale. The toner was gently put in, and the toner swelled from the upper part of the glass cylinder was scraped off and measured by measuring its weight.

The toner according to the present invention has a volume average particle diameter (Dv) of 3 to 8 μm and a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) of 1.0 to 1. 3 is preferred. By using a toner having such a particle size and particle size distribution, it is excellent in heat-resistant storage stability, low-temperature fixability, and hot offset resistance, and particularly when used in a full-color copying machine, etc. Sex is obtained.
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. In addition, when the volume average particle size is smaller than the range of the present invention, the two-component developer is not preferable because the toner is fused to the surface of the magnetic carrier during a long period of stirring in the developing device and the charging ability of the magnetic carrier is lowered. .
On the contrary, when the volume average particle diameter of the toner is larger than the range of the present invention, it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed. In many cases, the variation in toner particle size becomes large.
On the other hand, if Dv / Dn exceeds 1.30, the charge amount distribution becomes wide and the resolving power decreases, which is not preferable.
The value of Dv / Dn was measured using a Coulter counter TA-II (manufactured by Coulter, Inc.) as with the volume average particle diameter (Dv).

The toner according to the present invention preferably has an average circularity in the range of 0.930 to 0.965. The circularity is represented by the following formula (2), and the closer to a true sphere, the closer to 1 is.
Circularity SR = (perimeter of a circle having the same area as the particle projection area / perimeter of the particle projection image) Equation (2)
The toner having a high average circularity is easily affected by electric lines of force on the magnetic carrier or the developing sleeve, and is faithfully developed along the electric lines of force of the electrostatic latent image. When reproducing minute latent image dots, fine line reproducibility is enhanced because it is easy to obtain a dense and uniform toner arrangement. However, if the average circularity exceeds 0.965, problems such as slipping of the cleaning blade occur in the cleaning process during image formation, which is not preferable. On the other hand, if it is less than 0.930, the dot reproducibility is deteriorated and the contact point of the toner with the photosensitive member is increased, so that the releasability is deteriorated and the transfer rate is lowered.

  The average circularity of the toner can be measured using a flow type particle image analyzer (FPIA-2000; manufactured by Sysmex Corporation). In a predetermined container, 100 to 150 mL of water from which impure solids are removed in advance is added, 0.1 to 0.5 mL of a surfactant is added as a dispersant, and about 0.1 to 9.5 g of a measurement sample is further added. The suspension in which the sample is dispersed is subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the concentration and dispersion of the dispersion are set to 3,000 to 10,000 / μL, and the shape and distribution of the toner are measured.

  In order to produce the toner according to the present invention having the above shape, resin particles obtained by a conventional kneading pulverization method are spheroidized by, for example, a spray drying method, and the spheroidized resin particles are subjected to heat and mechanical shearing. It may be deformed by giving force. However, the resin particles obtained by the kneading and pulverization method have a wide particle size distribution, an irregular shape, and a large amount of particles that are not suitable for classification operation are removed. Therefore, the toner is preferably produced using the following polymerization method.

  The toner according to the present invention is preferably produced as follows. An oil phase formed by dissolving and / or dispersing a toner composition containing a toner binder component comprising a modified polyester resin capable of reacting with a compound having an active hydrogen group in an organic solvent, in an aqueous medium containing organic resin fine particles To obtain an emulsified dispersion, which is obtained by subjecting the modified polyester resin to elongation and / or cross-linking reaction with a compound having an active hydrogen group in the emulsified dispersion. Hereinafter, examples of the constituent material and the manufacturing method of the toner will be described.

(Modified polyester)
The toner according to the present invention contains a modified polyester (i) as a binder resin. The modified polyester (i) refers to a state in which a bonding group other than an ester bond is present in the polyester resin, or resin components having different configurations are bonded to the polyester resin by a covalent bond, an ionic bond, or the like. Specifically, the polyester terminal is modified by introducing a functional group such as a carboxylic acid group or an isocyanate group that reacts with a hydroxyl group into the polyester terminal and further reacting with an active hydrogen-containing compound.

  Examples of the modified polyester (i) include urea-modified polyester obtained by a reaction between a polyester prepolymer (A) having an isocyanate group and amines (B). As the polyester prepolymer (A) having an isocyanate group, a polyester having a polycondensate of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC) and having an active hydrogen group is further added to a polyvalent isocyanate compound (PIC). And those reacted with. Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl 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.

The urea-modified polyester is produced as follows.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Examples of the dihydric alcohol (DIO) include alkylene glycols having 4 to 30 carbon atoms (for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol). , Octanediol and 2,2-diethyl-1,3-propanediol); alkylene ether glycols having a molecular weight of 50 to 10,000 (for example, diethylene glycol, triethylene glycol, polypropylene glycols having a molecular weight of 50 to 10,000, and polytetra Methylene ether glycol and the like); alicyclic diols having 6 to 24 carbon atoms (for example, 1,4-cyclohexanedimethanol and hydrogenated bisphenol A); bisphenols having 15 to 30 carbon atoms (bisphenol A and bisphenol F) Bisphenol S and the like; alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts (addition mole number 2 to 100) of the above bisphenol (for example, bisphenol A ethylene oxide 2 mol addition, bisphenol A ethylene oxide 4 mol addition) Bisphenol A propylene oxide 2 mol adduct, bisphenol A propylene oxide 3 mol adduct, bisphenol A propylene oxide 4 mol adduct, etc.).
Among these, alkylene glycol and an alkylene oxide adduct of bisphenol are preferable, and an alkylene oxide adduct of bisphenol and a mixture of this with an alkylene glycol are more preferable.

  Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) with a small amount of (TC) Mixtures are preferred. Divalent carboxylic acids (DIC) include alkane dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, alkene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms are preferable. Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).

  The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

  Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.

  The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 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 urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.

The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, 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 wt%, the low-temperature fixability deteriorates.
The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. 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.

Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acid block of B1 to B5 (B6).
Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyvalent amine compound (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.

The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). 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 urea-modified polyester is lowered, and the hot offset resistance is deteriorated.
The urea-modified polyester may contain a urethane bond together with 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.

The modified polyester (i) used in the present invention is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. The peak molecular weight at this time is preferably 1000 to 10000. When the molecular weight is less than 1000, the elongation reaction hardly occurs, the elasticity of the toner is small, and as a result, the resistance to hot offset deteriorates. On the other hand, when it exceeds 10,000, the problem in production becomes high in the deterioration of fixability, particle formation and pulverization. The number average molecular weight of the modified polyester (i) is not particularly limited when the unmodified polyester (ii) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. (I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color device are deteriorated.
In the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B) to obtain the modified polyester (i), a reaction terminator is used as necessary to adjust the molecular weight of the resulting urea-modified polyester. be able to. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).
The molecular weight of the polymer produced can be measured using gel permeation chromatography (GPC) with THF as a solvent.

(Unmodified polyester)
In the present invention, not only the modified polyester (i) is used alone, but also the unmodified polyester (ii) can be contained as a binder resin component together with the (i). By using (ii) in combination, the low-temperature fixability and the gloss when used in a full-color device are improved, which is preferable to single use. Examples of (ii) include polycondensates of polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) similar to the polyester component of (i), and preferred ones are also the same as (i). . (Ii) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, and may be modified with a urethane bond, for example. It is preferable that (i) and (ii) are at least partially compatible in terms of low-temperature fixability and hot offset resistance. Accordingly, the polyester component (i) and (ii) preferably have similar compositions. When (ii) is contained, the weight ratio of (i) to (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80. When the weight ratio of (i) is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The peak molecular weight of (ii) is usually 1000 to 10,000, preferably 2000 to 8000, and more preferably 2000 to 5000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of (ii) is preferably 1 to 5, more preferably 2 to 4. Since a high acid value wax is used as the wax, the low acid value binder leads to electrification and high volume resistance, so that it is easy to match the toner used for the two-component developer.

The glass transition point (Tg) of the binder resin is usually 35 to 70 ° C, preferably 55 to 65 ° C. If the temperature is lower than 35 ° C., the heat-resistant storage stability of the toner deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the toner of the present invention tends to have good heat storage stability even when the glass transition point is low, as compared with known polyester-based toners. Show.
The glass transition point (Tg) can be measured with a differential scanning calorimeter (DSC).

(Coloring agent)
As the colorant, 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 Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmin Min 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, Toluidine 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, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red Polyazo Red, Chrome Vermillion, 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, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russian nin 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 weight, preferably 3 to 10% by weight, based on the toner.

  The colorant can also be used as a master batch combined with a resin. As a binder resin to be kneaded with the production of the master batch or the master batch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyl toluene or the like, or a copolymer of these and a vinyl compound, Polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be mentioned, and these can be used alone or in combination.

(Charge control agent)
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, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, 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) Manufactured), copper phthalocyanine, perylene, quinacridone, azo series Fee, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.
The amount of the charge control agent used is determined 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 not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the flowability of the developer is lowered, and the image density is lowered. Invite.

(Release agent)
As a release agent, a low melting point wax having a melting point of 50 to 120 ° C. works more effectively as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface. The effect on high temperature offset is exhibited without applying a release agent such as oil. Examples of such a wax component include the following. Examples of waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, and rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, and paraffin, microcrystalline, And petroleum waxes such as 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, chlorinated hydrocarbon, and low molecular weight crystalline polymer resin, poly-n-stearyl methacrylate, poly-n- A crystalline polymer having a long alkyl group in the side chain such as a homopolymer or copolymer of polyacrylate such as lauryl methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used. .
The charge control agent and the release agent can be melt-kneaded together with the master batch and the binder resin, and of course, they may be added when dissolved and dispersed in the organic solvent.

Next, a toner manufacturing method will be described. Here, although a preferable manufacturing method is shown, it is not limited to this.
(Toner production method)
1) A toner material solution is prepared by dissolving or dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent.
The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, 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 an organic solvent is 0-300 weight part normally with respect to 100 weight part of polyester prepolymers, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part.

2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and organic resin fine particles.
The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.
The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical.

Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and organic resin fine particles is appropriately added.
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 And the like.

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- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, 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) Perful Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.
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 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), 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).

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

As the organic resin fine particles, any resin that can form an aqueous dispersion can be used, and it may be a thermoplastic resin or a thermosetting resin. Examples thereof include vinyl resins, polyurethane resins, epoxy resins, polyester resins, polyamide resins, polyimide resins, silicon resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonate resins. As the resin, two or more of the above resins may be used in combination.
Of these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, and combinations thereof are preferred because an aqueous dispersion of fine spherical resin particles is easily obtained. For example, vinyl resins are polymers obtained by homopolymerization or copolymerization of vinyl monomers, such as styrene- (meth) acrylic acid ester copolymers, styrene-butadiene copolymers, (meth) acrylic acid-acrylic acid esters. Examples thereof include resins such as a polymer, a styrene-acrylonitrile copolymer, a styrene-maleic anhydride copolymer, and a styrene- (meth) acrylic acid copolymer. The average particle diameter of the organic resin fine particles is 5 to 200 nm, preferably 20 to 300 nm.
In addition, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.

  As a dispersant that can be used in combination with the organic resin fine particles and the inorganic compound dispersant, 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 Such as acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Luric acid esters, 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, or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl Nitrogen compounds such as imidazole and ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, poly Xoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxy Polyoxyethylenes such as ethylene nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  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. Among these, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm. 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.

3) At the same time as the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group.
This reaction involves molecular chain crosslinking and / or elongation. The reaction time is selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. 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.

4) After completion of the reaction, a shearing force is applied to the emulsified dispersion (reactant) to deform the toner particles. The organic solvent is removed from the emulsified dispersion, washed and dried to obtain toner base particles.
The method for removing the organic solvent is not particularly limited as long as the solvent can be removed, such as atmospheric pressure desolvation by blowing a liquid phase of air or nitrogen, vacuum desolvation, etc. A solvent is preferred. When the pressure is reduced, the degree of pressure reduction is preferably 1 to 90 kPa, more preferably 5 to 50 kPa.
The temperature of solvent removal is not particularly limited, but is preferably 0 to 60 ° C., more preferably 5 to 50 ° C., particularly 10 to 40 ° C. from the viewpoint of preventing toner particle coalescence.

Spindle-shaped toner base particles can be prepared by applying strong stirring in a laminar stirring state simultaneously with and / or before and after solvent removal, and applying a shearing force to the emulsified dispersion. As the solvent is removed, the viscosity of the emulsified dispersion increases. In particular, in order to efficiently obtain spindle-shaped toner base particles, a water-soluble thickener is added to the emulsified dispersion to adjust the viscosity. It is good.
Water-soluble thickeners include polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, polyacrylate (alkali metal salts, organic amine salts, quaternary ammonium salts, etc .; weight average molecular weight 3,000 to 3,000, 000), carboxymethylcellulose, polyethylene glycol (weight average molecular weight 2,000 to 200,000), guar gum and the like.

  The viscosity of the emulsified dispersion when applying a shearing force is preferably 5,000 to 100,000 mPa · s, more preferably 6,000 to 80,000 mPa · s, and particularly preferably 6,000 to 50, 000 mPa · s. If it is 5,000 mPa · s or more, the toner particles are easily deformed and the deformation process can be shortened. If it is 100,000 mPa · s or less, toner fine powder is hardly generated, and the toner is finally removed after removing the organic solvent. The desired particle size distribution is easily obtained.

The apparatus for applying a shearing force to the emulsified dispersion is not particularly limited as long as it is commercially available as a stirrer / or a disperser.
Preferable specific examples include a stirrer having a 1-10 stage paddle stirrer, a helical ribbon stirrer, a max blend stirrer and the like. Among these, a helical ribbon stirrer and a max blend stirrer are more preferable from the viewpoint of imparting a uniform shearing force.

The temperature at which the shearing force is applied is not particularly limited, but is preferably 0 to 60 ° C., more preferably 5 to 50 ° C., particularly 10 to 40 ° C. from the viewpoint of ease of deformation of the toner particles and prevention of toner particle coalescence. It is.
The time for applying the shearing force varies depending on the apparatus for applying the shearing force and is not particularly limited. However, from the viewpoint of ease of deformation and productivity of the resin particles, the above-described stirrer (stirrer having 1 to 10 paddle type stirring blades, helical When using a ribbon stirrer or a max blend stirrer), 30 minutes to 20 hours are preferable, more preferably 1 to 16 hours, particularly 2 to 15 hours, and most preferably 3 to 10 hours. When using a machine (batch type disperser, continuous disperser, high pressure disperser, membrane disperser, vibration disperser, ultrasonic disperser, etc.), 0.01 seconds to 3 hours are preferable, more preferably It is 0.01 seconds to 30 minutes, particularly 0.01 seconds to 10 minutes, and most preferably 0.01 seconds to 5 minutes.

  The shearing force varies depending on the viscosity of the emulsified dispersion, the time for applying the shearing force, and the temperature at that time, and can be appropriately selected. From the viewpoint of ease of deformation of the resin particles and ease of particle size control, for example, In the apparatus for applying a shearing force exemplified above, the shearing force is preferably applied at a rotation speed of 20 to 10,000 rpm, more preferably 30 to 5,000 rpm, and particularly preferably 50 to 2,000 rpm.

  Further, the concentration of the organic solvent in the emulsified dispersion when applying the shearing force is preferably 2 to 10% by weight, more preferably 2.5 to 9% by weight, and particularly preferably 3 to 8% by weight. . If the amount is 2% by weight or more, the toner is easily deformed, and the deformation process can be shortened. If the amount is 10% by weight or less, restoration after the deformation hardly occurs. Cheap.

The organic solvent concentration is adjusted to a desired concentration by desolvation.
The organic solvent concentration is measured under the following conditions using gas chromatography.
[Measurement of organic solvent concentration]
Apparatus: Gas chromatograph manufactured by Shimadzu Corporation
SIMAZU GC-14A
Column: PEG 20M 20%
Chromasorb W MESH 60-80
Column temperature: 100 ° C
Injection temperature: 180 ° C
Nitrogen gas flow rate: 40 ml / min Sample solution: 5% dimethylformamide solution injection volume: 1 μL
Detector: FID
A calibration curve was prepared using n-hexane as a standard substance, and the organic solvent concentration was determined.

In order to control the flatness (Dv / d) of the toner in the present invention in the range of 1.2 to 2.0, the above-mentioned stirring rotation speed, stirring time, emulsion dispersion viscosity when applying shear, and shearing are used. The organic solvent concentration in the emulsified dispersion when applying force is appropriately set.
When the flatness (Dv / d) of the toner is less than 1.2, it can be increased to 1.2 or more by increasing the shearing force. Specific measures include 1) increasing the number of rotations of stirring, 2) extending the stirring time, and 3) increasing the viscosity of the emulsified dispersion by additionally adding a thickener or the like.
When the flatness (Dv / d) of the toner is likely to exceed 2.0, it can be controlled by reducing the shearing force. Specific measures include 1) lowering the number of stirring revolutions, and 2) lowering the viscosity of the emulsified dispersion by additionally adding water or the like. Further, the ethyl acetate in the emulsified dispersion may be further removed to remove the ethyl acetate from the oil droplets containing the toner base particles, thereby increasing the viscosity of the particles.

  If necessary, a charge control agent is injected into the toner base particles obtained above, and then inorganic fine particles such as silica fine particles and titania fine particles are externally added to obtain toner. The injection of the charge control agent and the external addition of the inorganic fine particles are performed by a known method using a mixer or the like.

An image forming apparatus using the toner of the present invention as a developer will be described.
FIG. 2 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention. In the figure, reference numeral 100 is a copying apparatus main body, 200 is a paper feed table on which the copying apparatus is placed, 300 is a scanner mounted on the copying apparatus main body 100, and 400 is an automatic document feeder (ADF) mounted thereon.
The copying apparatus main body 100 has a tandem type in which four image forming units 18 each having various units for performing an electrophotographic process such as charging, developing, and cleaning are arranged in parallel around a photosensitive member 40 as a latent image carrier. An image forming apparatus 20 is provided. Above the tandem image forming apparatus 20, there is provided an exposure apparatus 21 that exposes the photoreceptor 40 with laser light based on image information to form a latent image. Further, an intermediate transfer belt 10 made of an endless belt member is provided at a position facing each photoconductor 40 of the tandem type image forming apparatus 20. A primary transfer unit 62 for transferring the toner images of the respective colors formed on the photoconductor 40 to the intermediate transfer belt 10 is disposed at a position facing the photoconductor 40 via the intermediate transfer belt 10.
A secondary transfer device 22 that collectively transfers the toner images superimposed on the intermediate transfer belt 10 onto transfer paper conveyed from the paper feed table 200 is disposed below the intermediate transfer belt 10. The secondary transfer device 22 is configured by spanning a secondary transfer belt 24 that is an endless belt between two rollers 23, and is disposed by pressing against the support roller 16 via the intermediate transfer belt 10. The toner image on 10 is transferred onto a transfer sheet. A fixing device 25 for fixing the image on the transfer paper is provided beside the secondary transfer device 22. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt.
The secondary transfer device 22 described above also has a sheet transport function for transporting the transfer paper after image transfer to the fixing device 25. Of course, a transfer roller or a non-contact charger may be arranged as the secondary transfer device 22, and in such a case, it is difficult to provide this sheet conveyance function together.
In the illustrated example, a reversing device 28 for reversing the transfer paper so as to record images on both sides of the transfer paper is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20 described above. .

The developing device 4 of the image forming unit 18 uses a developer containing toner according to the present invention. The developing device 4 can be, for example, a developing device having the configuration shown in FIG. The developing container 401 is provided with an opening at a position facing the photoconductor 40, and a developing sleeve 402 having a magnetic field generating means inside is provided in the opening with a predetermined gap from the photoconductor 40. A layer thickness regulating member 406 that regulates the layer thickness of the developer carried on the developing sleeve 402 is provided above the developing sleeve 402. In addition, stirring screws 403 and 404 are provided below the developing sleeve 402 of the developing container 401 so that the developer of the present invention is conveyed to the developing sleeve 402 side while stirring.
Further, a toner concentration sensor 405 is provided at the bottom of the developing container 401. The toner concentration sensor 405 detects the apparent magnetic permeability of a fixed volume of developer in the vicinity and detects the toner concentration in the developer from the change in the magnetic permeability. Yes. By using the developer of the present invention, since the change in the bulk density of the developer is small, the toner density detection by the toner density sensor 405 is not hindered, and the toner can be replenished normally over time. . As a result, abnormal images such as dirt are not generated.

  The developing device 4 can be a process cartridge that is integrally supported with the photoconductor 40 and is detachably formed on the main body of the image forming apparatus. In addition, the process cartridge may include a charging unit and a cleaning unit. Thereby, exchangeability and convenience can be achieved, and maintenance of the image forming apparatus can be facilitated.

The operation of the image forming apparatus is as follows.
First, a document is set on the document table 30 of the automatic document feeder 400, or the automatic document feeder 400 is opened and a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed. Hold it down.
When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. At that time, the scanner 300 is immediately driven to travel the first traveling body 33 and the second traveling body 34. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34 and reflects by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.

  When a start switch (not shown) is pressed, one of the support rollers 14, 15 and 16 is rotationally driven by a drive motor (not shown), the other two support rollers are driven to rotate, and the intermediate transfer belt 10 is rotated and conveyed. To do. At the same time, the individual image forming means 18 rotates the photoconductor 40 to form black, yellow, magenta, and cyan monochrome images on each photoconductor 40. Then, along with the conveyance of the intermediate transfer belt 10, the monochrome images are sequentially transferred to form a composite color image on the intermediate transfer belt 10.

On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, and the sheet is fed out from one of the paper feed cassettes 44 provided in multiple stages in the paper bank 43, and the separation roller 45. Then, the sheets are separated one by one into the paper feed path 46, transported by the transport roller 47, guided to the paper feed path 48 in the copying machine main body 100, and abutted against the registration roller 49 and stopped.
Alternatively, the sheet feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped.
Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer belt 10, the sheet is fed between the intermediate transfer belt 10 and the secondary transfer device 22, and is transferred by the secondary transfer device 22. A color image is recorded on the sheet.

The image-transferred sheet is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the switching roller 55 is used to switch the discharge image. The paper is discharged at 56 and stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.
On the other hand, the intermediate transfer belt 10 after the image transfer is removed by the intermediate transfer belt cleaning device 17 to remove residual toner remaining on the intermediate transfer belt 10 after the image transfer, so that the tandem image forming apparatus 20 can prepare for the image formation again.

  Hereinafter, the present invention will be described more specifically with reference to examples. “Part” means part by weight.

(Example 1)
~ Synthesis of organic resin fine particle emulsion ~
In a reaction vessel equipped with a stir bar and a thermometer, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 80 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate, 12 parts of butyl thioglycolate and 1 part of ammonium persulfate were added and stirred for 15 minutes at 400 rpm, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours. A dispersion was obtained. This is designated as [fine particle dispersion 1]. The volume average particle diameter of this [fine particle dispersion 1] measured by a laser diffraction particle size distribution analyzer (LA-920, manufactured by Shimadzu Corp.) was 120 nm. A portion of [Fine Particle Dispersion 1] was dried to isolate the resin component. The Tg of the resin was 72 ° C., and the weight average molecular weight was 30,000.

-Adjustment of aqueous phase-
990 parts of water, 83 parts of [fine particle dispersion 1], 37 parts of a 48.5% aqueous solution of dodecyl diphenyl ether disulfonate (Eleminol MON-7: manufactured by Sanyo Chemical Industries) and 90 parts of ethyl acetate are mixed and stirred to give a milky white liquid. Got. This is designated as [Aqueous Phase 1].

~ Synthesis of low molecular weight polyester ~
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts terephthalic acid, 46 parts adipic acid and dibutyl Add 2 parts of tin oxide, react for 8 hours at 230 ° C. under normal pressure, and further react for 5 hours under reduced pressure of 10 to 15 mmHg, then add 44 parts of trimellitic anhydride to the reaction vessel, and leave for 2 hours at 180 ° C. and normal pressure. Reacted to obtain a polyester. This is referred to as [low molecular polyester 1]. This [low molecular polyester 1] had a number average molecular weight of 2500, a weight average molecular weight of 6700, a Tg of 43 ° C., and an acid value of 25.

~ Synthesis of intermediate polyester ~
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 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, trimellitic anhydride 22 And 2 parts of dibutyltin oxide were added, reacted at 230 ° C. under normal pressure for 8 hours, and further reacted at reduced pressure of 10 to 15 mmHg for 5 hours to obtain a polyester. This is referred to as [intermediate polyester 1]. This [Intermediate polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, Tg of 55 ° C., an acid value of 0.5, and a hydroxyl value of 51.
Next, 410 parts of [Intermediate polyester 1], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, and reacted at 100 ° C. for 5 hours. I got a thing. This is designated as [Prepolymer 1]. This [Prepolymer 1] had a free isocyanate weight percentage of 1.53%.

~ Synthesis of ketimine ~
In a reaction vessel equipped with a stirrer and a thermometer, 170 parts of isophoronediamine and 150 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain a ketimine compound. This is referred to as [ketimine compound 1]. The amine value of [ketimine compound 1] was 418.

~ Master batch synthesis ~
Add 1200 parts of water, 540 parts of carbon black (Printex35: manufactured by Dexa) (DBP oil absorption = 42 ml / 100 mg, pH = 9.5), 1200 parts of polyester resin (RS801: manufactured by Sanyo Chemical), and Henschel mixer (Mitsui Mining Co., Ltd.) The mixture was kneaded at 150 ° C. for 30 minutes using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain a master batch. This is referred to as [master batch 1].

~ Preparation of oil phase ~
In a container equipped with a stir bar and a thermometer, 378 parts of [Low molecular weight polyester 1], 110 parts of Carnauba WAX, and 947 parts of ethyl acetate were charged, heated to 80 ° C. with stirring, and kept at 80 ° C. for 5 hours. Cooled to 30 ° C. in 1 hour. Next, 500 parts of [Masterbatch 1] and 500 parts of ethyl acetate were charged in a container and mixed for 1 hour to obtain a mixed solution. This is referred to as [Raw material solution 1].

  [Raw material solution 1] 1324 parts were transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads were 80% by volume. Carbon black and WAX were dispersed under conditions of filling and 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of [low molecular weight polyester 1] was added, and one pass was performed with a bead mill under the above conditions to obtain a dispersion. This is designated as [Pigment / WAX Dispersion 1]. The solid content concentration of the [Pigment / WAX Dispersion 1] (solid content after drying at 130 ° C. for 90 minutes) was 50%.

~ Emulsification, solvent removal, toner particle deformation ~
120 parts of [Pigment / WAX Dispersion 1], 20 parts of [Prepolymer 1] and 1.2 parts of [Ketimine Compound 1] were mixed to prepare [Resin and Colorant Adjustment Liquid 1] having a solid content concentration of 50%. Obtained. After adding 150 parts of [resin and colorant adjustment solution 1] to 200 parts of [aqueous phase 1], a TK homomixer (manufactured by Koki Kogyo Co., Ltd.) is used, and the rotational speed is 12,000 rpm at 25 ° C. for 1 minute. Mixing was performed to obtain an emulsified dispersion (1).
100 parts of this emulsified dispersion (1) was transferred to a stainless steel Kolben equipped with a helical ribbon type three-stage stirring blade, and stirred at a rotational speed of 60 rpm, under reduced pressure (10 kPa) at 25 ° C. for 6 hours in the emulsion. Ethyl acetate was removed from the solution until the concentration of the solution became 5% to obtain an emulsified dispersion (Y-1).
To this emulsified dispersion (Y-1), 3.1 parts of carboxymethylcellulose (Serogen HH, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added and thickened. (10 kPa), the ethyl acetate was removed from the emulsion until the ethyl acetate concentration in the emulsion reached 3%, the rotational speed was reduced to 60 rpm, and then the solvent was removed until the ethyl acetate concentration reached 1% [dispersed slurry. 1] was obtained. The viscosity of the emulsion after thickening was 25,000 mPa · s.

~ Washing, drying ~
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
(1): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(2): 100 parts of a 0.1% aqueous sodium hydroxide solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure.
(3): 100 parts of 0.1% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(4): Add 300 parts of ion-exchanged water to the filter cake of (3), mix with a TK homomixer (10 minutes at 12,000 rpm), and then filter twice to obtain [filter cake 1]. It was.
[Filter cake 1] was dried at 45 ° C. for 48 hours in a circulating dryer. Thereafter, the resultant was sieved with a 75 μm mesh to obtain toner base particles having a volume average particle size of 5.0 μm and a fine powder content of 14% by number of 3.17 μm or less. This is designated as [toner base particle 1].

~ External additive treatment ~
To 100 parts of [Toner Base Particle 1] obtained above, 0.7 part of hydrophobic silica and 0.3 part of hydrophobic titanium oxide as external additives were mixed with a Henschel mixer, and [Toner 1 ] Was obtained.

-Production of developer-
To 5 parts of the above [Toner 1], 95 parts of [Magnetic Carrier 1] according to the following formulation were mixed with a Turbula mixer to obtain [Developer 1].
(Magnetic carrier)
A rotating disk type fluidized bed coating apparatus is prepared by dissolving 5 parts of a ferrite carrier and 500 parts of silicone resin SR2411 (Toray Dow Corning) in 1200 parts of toluene and adding 10 parts of carbon black to disperse. The coating was carried out at a drying temperature of 90 ° C. during carrier coating. Thereafter, the film was aged by heating at 250 ° C. for 2 hours to obtain [Magnetic Carrier 1]. [Magnetic carrier 1] had a volume average particle diameter of 56 μm, a volume resistance of 10 ¹⁴ Ω · cm, and a saturation magnetization of 65 emu / g.

(Examples 2-4, Comparative Examples 1-4)
In the toner production example of Example 1, the degree of irregularity of the toner shape is changed by sequentially changing the stirring rotation speed of the disperser, the stirring time, and the viscosity of the emulsified dispersion when applying the shear, and the flatness and looseness of the toner are changed. [Toner 2] to [Toner 8] having different apparent densities were obtained.
Next, in the same manner as in Example 1, 95 parts of [Magnetic Carrier 1] was mixed with 5 parts of each of the above toners using a tumbler mixer to obtain [Developer 2] to [Developer 8].

  Table 1 summarizes the physical properties of the toners and developers obtained in Examples 1 to 4 and Comparative Examples 1 to 4, and the results of image evaluation using these developers.

(Evaluation item)
1) Image quality Image quality was determined comprehensively from transfer failure and image quality deterioration (specifically, generation of a soiled image). Regarding the transfer failure, 50K sheets were passed through imagio NEO450 manufactured by Ricoh Co., Ltd., and then a solid black image was passed through, and the transfer failure level of the image was visually judged. Also, for background stain images, 50K sheets are passed through the Ricoh Co., Ltd. imagio NEO450, and then the blank image is stopped during development, and the developer on the photoconductor after development is transferred to the tape. Then, the difference from the image density of the untransferred tape was measured with a spectrodensitometer (manufactured by X-Rite) and quantitatively evaluated. Evaluation was made with “◯” for images with good image quality and “×” for images with poor image quality.
2) Cleaning property Cleaning property was evaluated by performing a copying test using an imagio NEO450 manufactured by Ricoh Co., Ltd. Transfer the residual toner on the photoconductor that has passed through the cleaning process to a white paper with a scotch tape (manufactured by Sumitomo 3M Limited), and measure it with a Macbeth reflection densitometer RD514 type. : The number of sheets where 0.2 or more occurred was evaluated. Evaluation was made with “◯” indicating that the image was not generated on 100K sheets and “X” indicating that the image was generated on 100K sheets.

As can be seen from Table 1, in Examples 1 to 4 using the developer according to the present invention, it was found that the charging characteristics of the toner did not deteriorate over time and the image quality was excellent. Also, the cleaning property on the photoreceptor after the transfer process was good.
On the other hand, in Comparative Examples 1 to 3, deterioration in image quality such as transfer failure and background staining was observed. In Comparative Example 4, although the image quality was good, the results were poor in cleaning properties.

FIG. 3 is a diagram schematically illustrating the shape of a toner according to the present invention. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention. FIG. 2 is a schematic configuration diagram of a two-component developing device.

Explanation of symbols

4 Developing device 10 Intermediate transfer belt (intermediate transfer member)
18 Image forming means 21 Exposure device 25 Fixing device 40 Photosensitive member (latent image carrier)
22 Secondary transfer device 62 Primary transfer means 100 Copier main body 200 Paper feed table 300 Scanner 400 Automatic document feeder

Claims (9)

A toner composed of at least a colorant and a binder resin containing a modified polyester and a magnetic carrier;
A developer for developing an electrostatic latent image formed on a latent image carrier,
The toner is obtained by deforming by applying mechanical shear force in the liquid,
The flatness (Dv / d) of the toner is 1.2 to 2.0 (where Dv is the volume average particle diameter of the toner, and d is the average thickness when the toner is viewed from the direction where the projected area is maximized). is there.),
The developer having a bulk density change rate of 10% or less. The developer according to claim 1, wherein the toner has a loose apparent density of 0.37 g / cm ³ or more.   The developer according to claim 1, wherein the toner has a volume average particle diameter (Dv) of 3 to 8 μm and a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn). Is 1.0-1.3. The developing agent characterized by the above-mentioned.   The developer according to any one of claims 1 to 3, wherein the toner has an average circularity of 0.930 to 0.965.   5. The developer according to claim 1, wherein the toner dissolves a toner composition including a toner binder component made of a modified polyester resin capable of reacting with a compound having an active hydrogen group in an organic solvent. An oil phase formed by dispersing is dispersed in an aqueous medium containing organic resin fine particles to obtain an emulsified dispersion. In the emulsified dispersion, the modified polyester resin is elongated with a compound having an active hydrogen group and / or Or a toner obtained by a crosslinking reaction. A developing device for carrying and transporting a developer by a developer carrying member, forming an electric field at a position facing the latent image carrying member, and developing an electrostatic latent image on the latent image carrying member,
A developing device using the developer according to any one of claims 1 to 5.   The developing device according to claim 6, wherein the developing device includes a toner concentration detecting unit that detects a change in toner concentration in the developer as a change in magnetic permeability of the developer. A latent image carrier that carries the latent image and a developing unit that supplies toner to the electrostatic latent image formed on the surface of the latent image carrier to visualize the latent image are integrally supported to form an image. In the process cartridge formed detachably in the apparatus main body,
The developing device according to claim 6 or 7, wherein the developing means is a developing device. A latent image carrier that carries a latent image, a charging unit that uniformly charges the surface of the latent image carrier, and the surface of the charged latent image carrier is exposed based on image data, whereby an electrostatic latent image is obtained. An exposure unit for writing, a developing unit for supplying toner to the electrostatic latent image formed on the surface of the latent image carrier, and a visible image on the surface of the latent image carrier are transferred to a recording member. In an image forming apparatus including a transfer unit and a fixing unit that fixes a visible image on a recording member.
The image forming apparatus, wherein the developing unit is the developing device according to claim 6 or 7.

Images