JP2017003909A - Two-component developer, developer storage unit, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-component developer which has little spent toner composition on a carrier, has a stable charging ability over a long period of time, suppresses environmental variation of charging, and prevents occurrence of surface stain, in-machine contamination by toner scattering, and photoreceptor filming.SOLUTION: There is provided a two-component developer which contains a toner that contains at least a binder resin and a mold releasing agent and is prepared by externally adding inorganic fine particles, and a carrier that contains at least a core material and a resin coating layer and where a filler is contained in the resin coating layer, where in molecular weight distribution measured by GPC of a THF-soluble component of the toner, when an arbitrary molecular weight M where the molecular weight is in a range of 300 or more and 5,000 or less is selected, a difference between the maximum value and the minimum value of a peak intensity where the molecular weight M is in a range of ±300 is 30 or less, an external additive isolation rate of the toner is 30% or more and 90% or less, and the carrier has a filler exposed area rate occupied in the entire carrier surface after output of 50,000 sheets is 20% or more and 50% or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a two-component developer, a developer storage unit, and an image forming apparatus.

  Conventionally, in electrophotographic image formation, a latent image by an electrostatic charge is formed on an image carrier such as a photoconductive substance, and charged toner particles are attached to the electrostatic latent image to form a visible image. Forming. The visible image formed by the toner is finally transferred to a transfer medium such as paper, and then fixed to the transfer medium by heat, pressure, solvent gas, or the like, and becomes an output image.

  These image forming methods include a so-called two-component development method in which toner particles for charging a toner image are charged, friction charging by stirring and mixing of toner particles and carrier particles, and without using carrier particles. This is roughly divided into a so-called one-component development system in which charge is imparted to toner particles. Until now, in printers, copiers and multifunction devices based on this, where high speed and image reproducibility are required, due to demands such as toner particle charging stability, start-up stability, and long-term image quality stability, Many two-component development systems are used.

  Causes of deterioration of the two-component developer include wear and delamination of the resin coating layer on the carrier surface, crushing of the carrier particles, a decrease in charging performance due to spent toner particle components into the carrier particles, and desired electrical resistance. And the generation of debris and wear powder. Based on these factors, image quality degradation such as a decrease in image density, generation of background fogging, a decrease in resolving power, physical / electrical damage of an image carrier, charging member contamination, and other image forming systems Causes deterioration.

Therefore, conventionally, attempts have been made to extend the life and durability of the two-component developer. For example, in Patent Document 1, an acrylic resin is used for the coating layer, and the crosslinked silicone resin particles having a primary particle diameter of 0.1 to 1.0 μm are contained in the acrylic resin in an amount of 5 to 50% by mass, any of carbon black particles and silica particles. This improves the wear resistance of the carrier resin coating layer.
In Patent Document 2, the carrier core material has a coating layer containing a binder resin and conductive fine particles, and the carrier surface is provided with irregularities on the carrier surface by the conductive fine particles contained in the carrier coating layer. The spent material derived from the toner is removed by self-polishing each other to stabilize the charging.
However, in the conventional system in which the filler is only included in the carrier resin coating layer, since the filler is hard, there is a problem that the toner additive is buried when the developer is used, and toner-derived spent is likely to occur. there were.

Patent Document 3 discloses that the amount of external additive aggregates contained in the toner and the external additive carrier surface abundance ratio after outputting 20,000 images with a 20% image area are defined as the carrier spent index. Has been. In addition, a carrier having a resin coating layer on the surface of the core material is disclosed, and unevenness formed by non-conductive particles contained in the resin coating layer can prevent the carrier spent and scrape the spent attached to the carrier. It is disclosed.
However, if the amount of the external additive aggregate is large, the photoconductor filming and abnormal images are likely to occur, and the low molecular weight component contained in the toner is easily softened. Further improvement is demanded because toner particles are easily aggregated due to deterioration of properties and heat.

Furthermore, regarding the toner, in recent years, in the field of electrophotographic image forming technology, by using a toner for developing an electrostatic image having functionality, not only stably providing a high-quality image without image error, It is required to have energy saving properties such as fixing toner onto a medium at a lower temperature (low temperature fixability), and to provide a more technically advanced image forming apparatus.
As a technique relating to the toner in response to the above requirement, Patent Document 4 discloses an invention regarding a technique using a crystalline resin and an amorphous resin as a binder resin, imparting sharp melt properties to the toner, and low-temperature fixability. Is realized.
However, a toner using a crystalline resin has a problem of shortening the life as a developer because of high spent to the carrier.

  The present invention has been made in view of the above, has little spent of the toner composition on the carrier, has a stable charging ability over a long period of time, suppresses fluctuations in charging environment, and is contaminated in the machine due to background contamination and toner scattering. Another object of the present invention is to provide a two-component developer that does not cause photoconductor filming.

In order to solve the above problems, the present invention includes a toner containing at least a binder resin and a release agent and externally added with inorganic fine particles, and at least a core material and a resin coating layer. Is a two-component developer containing a carrier containing a filler, and in the molecular weight distribution measured by GPC of the THF soluble component of the toner, the molecular weight is in the range of 300 to 5,000. When M is selected, the difference between the maximum value and the minimum value of the peak intensity defined below in the range of ± 300 of the molecular weight M is 30 or less, and the external additive liberation rate of the toner is 30% or more. 90% or less, and the carrier is characterized in that the filler exposed area ratio in the entire carrier surface after outputting 50,000 sheets is 20% or more and 50% or less.
Peak intensity: Relative value obtained by plotting a molecular weight distribution curve in which the vertical axis is intensity and the horizontal axis is molecular weight by GPC measurement, and the maximum intensity value is 100 in the molecular weight range of 20000 or less.

  According to the present invention, there is little spent of the toner composition on the carrier, it has a stable charging ability over a long period of time, charging fluctuations in the environment are suppressed, surface contamination, in-machine contamination due to toner scattering, photoconductor filming, etc. A two-component developer that does not occur can be provided.

1 is a schematic explanatory diagram illustrating an example of an image forming apparatus of the present invention. It is a schematic explanatory drawing which shows the other example of the image forming apparatus of this invention. 1 is a schematic explanatory diagram illustrating an example using a tandem color image forming apparatus of an image forming apparatus of the present invention. It is a schematic explanatory drawing which shows the other example of the image forming apparatus of this invention.

  Hereinafter, a two-component developer, a developer storage unit, and an image forming apparatus according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below, and other embodiments, additions, modifications, deletions, and the like can be changed within a range that can be conceived by those skilled in the art, and any aspect is possible. As long as the functions and effects of the present invention are exhibited, the scope of the present invention is included.

  There are two problems to be solved by the present invention. Problem 1 is a decrease in charging stability due to carrier spent derived from the toner base. Problem 2 is a decrease in charging stability due to wear of the carrier resin coating layer.

  In order to achieve the first problem, it is necessary that the toner base is not brought into contact with the carrier in a state of being a two-component developer. In order to achieve Problem 2, it is necessary to improve the wear resistance of the carrier resin coating layer. As a simple technique conventionally used, there is a method of adding a filler into the resin coating layer. However, since the filler on the carrier surface is hard, when the carrier filler and the toner collide with stirring in the developing machine, the external additive on the toner surface is easily embedded in the toner.

  In other words, in the conventional technique, when a filler is added in the carrier resin coating layer in order to achieve the problem 2, the toner external additive is buried and the spent from the toner base is generated, thereby achieving the problem 1. It was difficult. Further, when the toner base contains a release agent such as wax or a crystalline resin described later, the carrier spent increases, so that it is difficult to maintain the charging stability.

As a result of intensive studies in view of the above problems, the present inventors have selected an arbitrary molecular weight M in the molecular weight range of 300 to 5000 in the molecular weight distribution measured by GPC of the THF soluble component of the toner. The difference between the maximum value and the minimum value of the peak intensity in the range of ± 300 of the molecular weight M is 30 or less, the external additive liberation rate of the toner is 30% or more and 90% or less, and after 50,000 sheets run It has been found important that the exposed area of the filler on the entire carrier surface is 20% or more and 50% or less.
By doing so, it was found that the external additive on the toner surface is hard to be buried inside even under stress in the developing machine, so that the carrier spent is small.

  In the range of the molecular weight M ± 300, when the difference between the maximum value and the minimum value of the intensity is larger than 30, the intensity difference means a peak mainly observed on the low molecular weight side. The peak seen on the low molecular weight side in the molecular weight distribution is mainly caused by low molecular weight components derived from raw materials. For example, the binder resin is derived from an unreacted residual monomer contained in the binder resin, or a dimer or trimer which is a low polymer.

  When the difference between the maximum value and the minimum value of the strength is larger than 30, that is, it indicates that there are many low molecular weight components contained in the toner, and the low molecular weight components have the characteristic of being easily melted by heat from the outside. . Therefore, it is easily softened by heat generated from the machine being used, heat during storage, and the like. Therefore, a toner having a large amount of low molecular weight components has poor heat-resistant storage stability, and toner particles are easily aggregated by heat.

In addition, since low molecular weight components are easily deformed and attached to external pressure, when a toner with a large amount of low molecular weight components is used as a developer, it can be used for a long time or under high temperature and high humidity. As a result, it adheres to the carrier or the developing member, and the chargeability over time is significantly reduced. Further, when the two-component developer is used, the external additive on the surface is easily buried in the toner base by contact with the carrier, and the surface state changes.
On the other hand, when the difference between the maximum value and the minimum value of the molecular weight is within the range of M ± 300, the external additive is difficult to be embedded in the toner, and the carrier spent hardly occurs.

  In the present invention, when an arbitrary molecular weight M in the molecular weight range of 300 to 5000 is selected in the molecular weight distribution measured by GPC of the THF soluble component of the toner, the peak intensity in the range of ± 300 of the molecular weight M is selected. The difference between the maximum value and the minimum value is 30 or less. The control method is not particularly limited, and examples thereof include a method of replacing the terminal hydrophilic group of the binder resin with a lipophilic group and a method of accelerating the reaction conditions for resin synthesis. The method for substituting the terminal hydrophilic group with a lipophilic group is not particularly limited, and examples thereof include a method of substituting the terminal hydroxyl group with phenoxyacetic acid or benzoic acid. The method for accelerating the reaction conditions for resin synthesis is not particularly limited, and examples include a method of reacting at a high temperature for a long time and increasing the degree of vacuum to remove the monomer.

The molecular weight distribution measured by GPC (gel permeation chromatography) of the THF soluble component of the toner is measured as follows.
Gel permeation chromatography (GPC) measuring device: GPC-8220GPC (manufactured by Tosoh Corporation)
Column: TSK-GEL SUPER HZ2000, TSK-GEL SUPER HZ2500, TSK-GEL SUPER HZ3000
Temperature: 40 ° C
Solvent: THF
Flow rate: 0.35 ml / min
Sample: THF sample solution adjusted to 0.15% by mass Sample pretreatment: The toner was dissolved in tetrahydrofuran THF (containing a stabilizer, manufactured by Wako Pure Chemical Industries, Ltd.) at 0.15 wt% and filtered through a 0.45 μm filter. The filtrate is used as a sample.

  The measurement is performed by injecting 10 μL to 200 μL of the THF sample solution. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts.

  As a standard polystyrene sample for preparing a calibration curve, as a standard polystyrene sample for preparing a calibration curve, a TSK standard polystyrene manufactured by Tosoh Corporation having a molecular weight of 37200, 6200, 2500, 589, molecular weights 28400, 20298, 10900, 4782, 1689, 1309 Standard polystyrene and toluene manufactured by Showa Denko are used. An RI (refractive index) detector is used as the detector.

  The GPC measurement results are plotted with a molecular weight distribution curve with the vertical axis representing the intensity and the horizontal axis representing the molecular weight, and the point where the peak intensity is maximum in the molecular weight range of 20000 or less is taken as 100 to correct the intensity of the entire molecular weight distribution curve. . The difference between the maximum and minimum intensities is calculated from the maximum value-minimum value of the intensity in an arbitrary molecular weight M ± 300 range of the obtained molecular weight distribution curve.

  In the toner of the present invention, inorganic fine particles are externally added, and the liberation rate of the external additive is 30% or more and 90% or less. Preferably, it is 40% or more and 80% or less. When the liberation rate is less than 30%, the additive is already embedded in the toner base in the external addition step, and the toner base composition tends to be carrier spent. In addition, charging stability is deteriorated. If the liberation rate exceeds 90%, the additive peels off due to stress in the developing machine, and the toner base is exposed, so that carrier spent is likely to occur or the photosensitive filming is likely to occur due to the free external additive. .

Here, the liberation rate of the external additive particles is measured as follows.
(1) A 200 mL ointment bottle was added with 100 mL of ion exchange water and 4.4 mL of a 33% by mass dry well aqueous solution (trade name: Drywell, manufactured by Fuji Film Co., Ltd.) containing a surfactant. Add 5 g of toner to the mixture, mix well with hand shaking 30 times, and let stand for 1 hour or more.
(2) Next, after stirring by hand shaking 20 times, using an ultrasonic homogenizer (trade name: homogenizer, model VCX750, CV33, manufactured by SONICS & MATERIALS), a dial was set at an output of 50%, and it exceeded 2 minutes under the following conditions. Apply sonic energy and disperse.
(Ultrasonic conditions)
・ Vibration time: 60 seconds continuous ・ Amplitude: 20 W (30%)
・ Vibration start temperature: 23 ℃ ± 1.5 ℃
(3) The obtained dispersion was suction filtered with a filter paper (trade name: qualitative filter paper (No. 2, 110 mm), manufactured by Advantech Toyo Co., Ltd.), washed again with ion-exchanged water, filtered, and freed. After removing the additive, the toner is dried.
(4) The amount of toner additive before and after removal of the external additive is calculated by mass% from the intensity (or intensity difference before and after removal of the external additive) by the calibration curve using a fluorescent X-ray analyzer (manufactured by Rigaku Corporation, ZSX-100e). Quantify by calculation to determine the free amount of external additives.

From the value of the external additive amount of the toner before and after the dispersion measured by the methods (1) to (4), the liberation rate (% by mass) of the external additive is obtained by the following mathematical formula 1.
[Formula 1]
Release rate = [(mass of external additive before dispersion−mass of residual additive after dispersion) / mass of external additive before dispersion] × 100

  Further, the carrier in the two-component developer of the present invention contains a core material and a resin coating layer, and the resin coating layer contains a filler, and is applied to the entire carrier surface after outputting 50,000 sheets (after the run). The filler exposed area ratio is 20% or more and 50% or less. Preferably, it is 25% or more and 40% or less.

  By exposing the filler in the carrier quickly, it is possible to prevent further wear of the resin coating layer from proceeding, so that a decrease in charging can be suppressed. Further, since the filler is exposed, an effect of scraping each other's spent object by collision between carriers can be expected. In addition, wear of the resin coating layer causes a decrease in charge, but the decrease can be compensated for by exposure of the filler. A carrier having a certain amount of filler exposed area has a large ability to impart charge to the toner. It is important to expose the filler because it has the effect of suppressing a decrease in charge over time.

  If the exposed area ratio of the filler in the entire carrier surface after the 50,000-sheet run is less than 20%, the charge imparting ability to the toner becomes insufficient. In addition, the ability to scrape toner-derived spent is not sufficient, so that the chargeability is further reduced. If the exposed area ratio of the filler exceeds 50%, the image quality changes due to a decrease in carrier resistance and carrier adhesion occurs. In addition, since the fluidity of the developer is lowered and the pumping amount is likely to be lowered, the toner concentration in the developer is increased and toner scattering occurs.

The filler exposed area ratio occupying the entire surface of the carrier after the 50,000-sheet run is obtained as follows.
The running of 50,000 sheets is output using a character image pattern having an image area ratio of 12% using each developer.
The carrier exposed area ratio of the carrier is such that a small amount of developer is collected from the sleeve of the developing unit after running and the toner is blown to obtain the carrier after running. EDX (energy dispersive X-ray spectroscopy) is used to perform mapping of the corresponding filler element under the following measurement conditions, then to determine the area ratio of the filler with respect to the area of the carrier particles by image processing, and further to the same work to 10 particles or more It is calculated by carrying out against. The acceleration voltage is an appropriate voltage depending on the filler type.

(EDX measurement conditions)
・ Sample fixing method Carbon tape (Nisshin EM 8mm × 20m type)
・ Carbon deposition ・ Acceleration voltage: 3-10kV
・ WD 11mm
・ Aperture diameter 30μm
・ Without drift correction ・ Without high current use ・ Time constant 20-30
・ EDX measurement magnification 2000 times ・ Number of integrations 100 times ・ Count mapping or quantitative mapping or simple quantitative mapping count mapping ・ Characteristic X-ray used for mapping (L line or K line) L line

<Other toner properties>
The shape, size, etc. of the toner are not particularly limited and can be appropriately selected according to the purpose. The average circularity, volume average particle size, volume average particle size and number average particle size are as follows. (Volume average particle diameter / number average particle diameter) and the like.

  The average circularity is a value obtained by dividing the circumference of an equivalent circle having the same projected shape as the shape of the toner by the circumference of the actual particles. For example, 0.950 to 0.980 is preferable, and 0.960 to 0 is preferable. .975 is more preferred. In addition, it is preferable that the particles having an average circularity of less than 0.95 are 15% or less.

  If the average circularity is less than 0.950, a satisfactory transferability and a high-quality image free from dust may not be obtained. On the other hand, if it exceeds 0.980, in an image forming system that employs blade cleaning or the like, a cleaning failure occurs on the photosensitive member and the transfer belt, and stains on the image, for example, an image area ratio such as a photographic image In the case of high image formation, the toner on which an untransferred image has been formed due to poor paper feeding or the like may become background smudges on the image accumulated as transfer residual toner on the photoreceptor. Alternatively, the charging roller that contacts and charges the photosensitive member may be contaminated, and the original charging ability may not be exhibited.

  The average circularity is measured using a flow type particle image analyzer (“FPIA-2100”, manufactured by Sysmex Corporation) and analyzed using analysis software (FPIA-2100 Data Processing Program for FPIA version 00-10). be able to.

  As a specific example, 0.1 to 0.5 ml of 10% by weight surfactant (alkylbenzene sulfonate, Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added to a glass 100 ml beaker, and each toner 0. Add 1-0.5 g and stir with microspatel, then add 80 mL of ion exchanged water. The obtained dispersion is subjected to a dispersion treatment for 3 minutes with an ultrasonic disperser (manufactured by Honda Electronics Co., Ltd.). The shape and distribution of the toner are measured with the FPIA-2100 until the concentration of the dispersion reaches 5,000 to 15,000 / μL.

  In this measurement method, it is important that the concentration of the dispersion is 5,000 to 15,000 / μL from the viewpoint of measurement reproducibility of average circularity. In order to obtain the concentration of the dispersion, it is necessary to change the conditions of the dispersion, that is, the amount of surfactant to be added and the amount of toner. The amount of the surfactant varies depending on the hydrophobicity of the toner as in the measurement of the toner particle diameter described above. If it is added in a large amount, noise due to bubbles is generated, and if it is too small, the toner cannot be sufficiently wetted. It will be enough. The amount of toner added varies depending on the particle size, and is small when the particle size is small, and needs to be increased when the particle size is large. By adding 5 g, the dispersion concentration can be adjusted to 5,000 / μl to 15,000 / μl.

  There is no restriction | limiting in particular as a volume average particle diameter of the said toner, Although it can select suitably according to the objective, For example, 3 micrometers-10 micrometers are preferable, and 4 micrometers-7 micrometers are more preferable. When the volume average particle size is less than 3 μm, in the case of a two-component developer, the toner may be fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier may be reduced. Therefore, it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed, the variation in the toner particle size may increase.

The ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) in the toner is preferably 1.00 to 1.25, and more preferably 1.00 to 1.15.
The volume average particle diameter and the ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) are measured using a particle size measuring device (“Multisizer III”, manufactured by Beckman Coulter, Inc.). The measurement can be performed with an aperture diameter of 100 μm and the analysis can be performed with analysis software (Beckman Coulter Multisizer 3 Version 3.51).

As a specific example, 0.5 ml of 10% by weight surfactant (alkylbenzene sulfonate, Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is added to a 100 ml beaker made of glass, and 0.5 g of each toner is added. Stir with a spatula and then add 80 ml of ion-exchanged water. The obtained dispersion is subjected to a dispersion treatment for 10 minutes with an ultrasonic disperser (W-113MK-II, manufactured by Honda Electronics Co., Ltd.). The dispersion can be measured using the Multisizer III and Isoton III (manufactured by Beckman Coulter) as a measurement solution.
In the measurement, the toner sample dispersion is dropped so that the concentration indicated by the apparatus is 8 ± 2%. In this measurement method, it is important that the concentration is 8 ± 2% from the viewpoint of the reproducibility of the particle size. Within this concentration range, no error occurs in the particle size.

<Toner raw material>
In the toner of the present invention, the toner base containing at least a binder resin and a release agent can contain other components as required. In addition, inorganic fine particles are used as an external additive in the toner base.

<< Binder resin >>
There is no restriction | limiting in particular as said binder resin, According to the objective, it can select suitably. For example, polyester resin, silicone resin, styrene / acrylic resin, styrene resin, acrylic resin, epoxy resin, diene resin, phenol resin, terpene resin, coumarin resin, amidoimide resin, butyral resin, urethane resin, ethylene vinyl acetate resin, etc. Can be mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, polyester resins and resins obtained by combining polyester resins with the above other binder resins are preferable because they are excellent in low-temperature fixability and have sufficient flexibility even when the molecular weight is reduced.

-Polyester resin-
There is no restriction | limiting in particular as said polyester resin, Although it can select suitably according to the objective, An unmodified polyester resin and a modified polyester resin are preferable. These may be used individually by 1 type and may use 2 or more types together.

--Unmodified polyester resin--
There is no restriction | limiting in particular as said unmodified polyester resin, According to the objective, it can select suitably. Examples thereof include resins obtained by polyesterification of a polyol represented by the following general formula (1) and a polycarboxylic acid represented by the following general formula (2), a crystalline polyester resin, and the like.

However, in the said General formula (1), A represents the aromatic group or heterocyclic aromatic group which may have a C1-C20 alkyl group, an alkylene group, and a substituent, m is 2- Represents an integer of 4.
In the general formula (2), B represents an alkyl group having 1 to 20 carbon atoms, an alkylene group, an aromatic group that may have a substituent, or a heterocyclic aromatic group, and n represents 2 to 2 Represents an integer of 4.

  There is no restriction | limiting in particular as a polyol represented by the said General formula (1), According to the objective, it can select suitably. For example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, Pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2, -Butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, bisphenol A, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, hydrogenated bisphenol A, hydrogenated bisphenol A oxidation Examples include ethylene adducts, hydrogenated bisphenol A propylene oxide adducts, and the like. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as polycarboxylic acid represented by the said General formula (2), According to the objective, it can select suitably. For example, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenyl succinic acid, isooctyl succinic acid , Isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, n-octyl succinic acid, isooctenyl succinic acid, isooctyl succinic acid, 1,2,4-benzenetricarboxylic acid, 2, , 5,7-Naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl- 2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, te La (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empole trimer acid, etc., cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid, butanetetracarboxylic acid, diphenylsulfonetetracarboxylic acid, And ethylene glycol bis (trimellitic acid). These may be used alone or in combination of two or more.

--Modified polyester resin--
There is no restriction | limiting in particular as said modified polyester resin, According to the objective, it can select suitably. For example, an active hydrogen group-containing compound, a resin obtained by subjecting a polyester capable of reacting with the active hydrogen group-containing compound (hereinafter sometimes referred to as “polyester prepolymer”) to an extension reaction and / or a crosslinking reaction, etc. Can be mentioned. The extension reaction and / or the cross-linking reaction may be stopped by a reaction terminator (blocked monoamine such as diethylamine, dibutylamine, butylamine, laurylamine, ketimine compound, etc.) as necessary.

--- Active hydrogen group-containing compound ---
The active hydrogen group-containing compound acts as an elongation agent, a crosslinking agent or the like when the polyester prepolymer undergoes an elongation reaction, a crosslinking reaction, or the like in an aqueous phase.
The active hydrogen group-containing compound is not particularly limited as long as it has an active hydrogen group, and can be appropriately selected according to the purpose. Especially, when the said polyester prepolymer is an isocyanate group containing polyester prepolymer mentioned later, amines are preferable at the point from which high molecular weight is attained.

  There is no restriction | limiting in particular as said active hydrogen group, According to the objective, it can select suitably. For example, a hydroxyl group (alcoholic hydroxyl group or phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, etc. are mentioned. These may be contained singly or in combination of two or more.

  There is no restriction | limiting in particular as said amines which are the said active hydrogen group containing compound, According to the objective, it can select suitably. Examples thereof include diamine, trivalent or higher polyamine, amino alcohol, amino mercaptan, amino acid, and those obtained by blocking the amino group of these amines.

Examples of the diamine include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, Isophorone diamine, etc.); aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like.
Examples of the trivalent or higher polyamine include diethylenetriamine and triethylenetetramine.
Examples of the amino alcohol include ethanolamine and hydroxyethylaniline.
Examples of the amino mercaptan include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of the amino acid include aminopropionic acid and aminocaproic acid.
Examples of the blocked amino groups of these amines include, for example, any of these amines (diamine, trivalent or higher polyamine, amino alcohol, amino mercaptan, amino acid, etc.) and ketones (acetone, methyl ethyl ketone, And ketimine compounds and oxazolyzone compounds obtained from methyl isobutyl ketone and the like.

  These may be used individually by 1 type and may use 2 or more types together. Among these, the amines are particularly preferably diamine and a mixture of a diamine and a small amount of a trivalent or higher polyamine.

--- Polymer capable of reacting with active hydrogen group-containing compound ---
The polymer that can react with the active hydrogen group-containing compound is not particularly limited as long as it is a polymer having at least a group that can react with the active hydrogen group-containing compound, and can be appropriately selected according to the purpose. Above all, it has excellent fluidity and transparency when melted, it is easy to adjust the molecular weight of the polymer component, and it is excellent in oil-less low-temperature fixability and releasability in dry toners. Is preferred, and an isocyanate group-containing polyester prepolymer is more preferred.

  There is no restriction | limiting in particular as said isocyanate group containing polyester prepolymer, According to the objective, it can select suitably. Examples thereof include polycondensates of polyols and polycarboxylic acids, and those obtained by reacting active hydrogen group-containing polyester resins with polyisocyanates.

There is no restriction | limiting in particular as said polyol, According to the objective, it can select suitably. For example, 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, 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 alicyclic diol, alkylene oxide of the bisphenol Diols such as adducts (ethylene oxide, propylene oxide, butylene oxide, etc.); polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.), trivalent or higher phenols (phenol novolac) , Cresol novolac, etc.) trihydric or higher polyols such as alkylene oxide adducts of trihydric or higher polyphenols; mixtures of diols and trihydric or higher polyols.
These may be used individually by 1 type and may use 2 or more types together. Among these, the polyol is preferably the diol alone or a mixture of the diol and a small amount of the trivalent or higher polyol.

  Examples of the diol include alkylene glycols having 2 to 12 carbon atoms, alkylene oxide adducts of bisphenols (bisphenol A ethylene oxide 2 mol adduct, bisphenol A propylene oxide 2 mol adduct, bisphenol A propylene oxide 3 mol adduct, etc.) Is preferred.

  There is no restriction | limiting in particular as content in the isocyanate group containing polyester prepolymer of the said polyol, According to the objective, it can select suitably. For example, 0.5 mass%-40 mass% are preferable, 1 mass%-30 mass% are more preferable, and 2 mass%-20 mass% are especially preferable. When the content is less than 0.5% by mass, the hot offset resistance is deteriorated, and it may be difficult to achieve both the storage stability of the toner and the low-temperature fixability. Fixability may deteriorate.

  There is no restriction | limiting in particular as said polycarboxylic acid, According to the objective, it can select suitably. For example, alkylene dicarboxylic acid (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acid (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acid (terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, etc.); Examples thereof include polycarboxylic acids (such as aromatic polycarboxylic acids having 9 to 20 carbon atoms such as trimellitic acid and pyromellitic acid). These may be used individually by 1 type and may use 2 or more types together.

  Among these, the polycarboxylic acid is preferably an alkenylene dicarboxylic acid having 4 to 20 carbon atoms and an aromatic dicarboxylic acid having 8 to 20 carbon atoms. In place of the polycarboxylic acid, an anhydride of polycarboxylic acid, a lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) may be used.

  There is no restriction | limiting in particular as a mixing ratio of the said polyol and the said polycarboxylic acid, According to the objective, it can select suitably. The equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] of the polyol and the carboxyl group [COOH] of the polycarboxylic acid is preferably 2/1 to 1/1, and 1.5 / 1 to 1/1. Is more preferable, and 1.3 / 1 to 1.02 / 1 is particularly preferable.

  There is no restriction | limiting in particular as said polyisocyanate, According to the objective, it can select suitably. For example, aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, tetramethylhexane Diisocyanates, etc.); cycloaliphatic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, diphenylene-4,4′-diisocyanate, 4,4 '-Diisocyanato-3,3'-dimethyldiphenyl, 3-methyl Diphenylmethane-4,4′-diisocyanate, diphenyl ether-4,4′-diisocyanate, etc.); araliphatic diisocyanate (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates (Tris-isocyanate) Natoalkyl-isocyanurate, triisocyanatocycloalkyl-isocyanurate, etc.); these phenol derivatives; those blocked with oxime, caprolactam and the like. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as a mixing ratio of the said polyisocyanate and the said active hydrogen group containing polyester resin (hydroxyl group containing polyester resin), According to the objective, it can select suitably. The equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] of the polyisocyanate and the hydroxyl group [OH] of the hydroxyl group-containing polyester resin is preferably 5/1 to 1/1, and 4/1 to 1.2. / 1 is more preferable, and 3/1 to 1.5 / 1 is particularly preferable. When the equivalent ratio [NCO] / [OH] is less than 1/1, the offset resistance may be deteriorated, and when it exceeds 5/1, the low-temperature fixability may be deteriorated.

  There is no restriction | limiting in particular as content of the said polyisocyanate in the said isocyanate group containing polyester prepolymer, According to the objective, it can select suitably. 0.5 mass%-40 mass% are preferable, 1 mass%-30 mass% are more preferable, 2 mass%-20 mass% are especially preferable. When the content is less than 0.5% by mass, the hot offset resistance is deteriorated, and it may be difficult to achieve both storage stability and low-temperature fixability. May get worse.

  The average number of isocyanate groups contained in one molecule of the isocyanate group-containing polyester prepolymer is preferably 1 or more, more preferably 1.2 to 5, and more preferably 1.5 to 4. When the average number is less than 1, the molecular weight of the polyester resin (RMPE) modified with a urea bond-forming group is lowered, and the hot offset resistance may be deteriorated.

  There is no restriction | limiting in particular as a mixing ratio of the said isocyanate group containing polyester prepolymer and the said amines, According to the objective, it can select suitably. The mixing equivalent ratio [NCO] / [NHx] of the isocyanate group [NCO] in the isocyanate group-containing polyester prepolymer and the amino group [NHx] in the amines is preferably 1/3 to 3/1. / 2 to 2/1 is more preferable, and 1 / 1.5 to 1.5 / 1 is particularly preferable. If the mixing equivalent ratio ([NCO] / [NHx]) is less than 1/3, the low-temperature fixability may be reduced. If it exceeds 3/1, the molecular weight of the urea-modified polyester resin is reduced. Hot offset resistance may deteriorate.

--- Method for synthesizing polymer capable of reacting with active hydrogen group-containing compound ---
There is no restriction | limiting in particular as a synthesis method of the polymer which can react with the said active hydrogen group containing compound, According to the objective, it can select suitably. For example, in the case of the isocyanate group-containing polyester prepolymer, the polyol and the polycarboxylic acid are heated to 150 ° C. to 280 ° C. in the presence of a known esterification catalyst (titanium tetrabutoxide, dibutyltin oxide, etc.). And a method of synthesizing by reacting the polyisocyanate with the hydroxyl group-containing polyester at 40 ° C. to 140 ° C. after the water is distilled off to obtain the hydroxyl group-containing polyester. .

  There is no restriction | limiting in particular as a weight average molecular weight (Mw) of the polymer which can react with the said active hydrogen group containing compound, According to the objective, it can select suitably. The molecular weight distribution by GPC (gel permeation chromatography) of the soluble portion of tetrahydrofuran (THF) is preferably 3,000 to 40,000, more preferably 4,000 to 30,000. When the weight average molecular weight (Mw) is less than 3,000, the storage stability may be deteriorated, and when it exceeds 40,000, the low temperature fixability may be deteriorated.

The weight average molecular weight (Mw) can be measured, for example, as follows. First, the column was stabilized in a 40 ° C. heat chamber, and at this temperature, tetrahydrofuran (THF) as a column solvent was flowed at a flow rate of 1 mL / min, and the sample concentration was adjusted to 0.05 to 0.6% by mass. Measurement is performed by injecting 50 μL to 200 μL of a tetrahydrofuran sample solution. In measuring the molecular weight of the sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of the calibration curve prepared by several monodisperse polystyrene standard samples and the number of counts.
As a standard polystyrene sample for preparing a calibration curve, Pressure Chemical Co. Or the molecular weight made by Toyo Soda Industry Co., Ltd. is 6 × 10, 2.1 × 10 ² , 4 × 10 ² , 1.75 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8.6 × It is preferable to use 10 ⁵ , 2 × 10 ⁶ , and 4.48 × 10 ⁶ , and use at least about 10 standard polystyrene samples. An RI (refractive index) detector can be used as the detector.

--- Crystalline resin--
Further, the binder resin contained in the toner in the present invention preferably contains a crystalline resin, and the melting point of the crystalline resin is preferably in the range of 50 ° C. or higher and 65 ° C. or lower. Since the crystalline resin exhibits a sharp melt property, the low-temperature fixability is improved. The crystalline resin is preferably present in the vicinity of the toner surface in order to increase the effect of low-temperature fixing. However, since the crystalline resin has a property of being easily spent on the carrier, the chargeability is likely to deteriorate with time.

  On the other hand, in the molecular weight distribution measured by GPC of the THF soluble component of the toner, when an arbitrary molecular weight M in the range of 300 to 5000 is selected, the peak intensity in the range of ± 300 of the molecular weight M is selected. By combining the toner in which the difference between the maximum value and the minimum value is 30 or less and the above resin in the present invention, the spent from the crystalline resin can be greatly suppressed, so that low temperature fixability in addition to charging stability Can be improved.

The melting point of the crystalline resin is measured by DSC. For example, it can be measured under the following measurement conditions using TA-60WS and DSC-60 manufactured by Shimadzu Corporation.
(Measurement condition)
Sample container: Aluminum sample pan (with lid)
Sample amount: 5mg
Reference: Aluminum sample pan (alumina 10mg)
Atmosphere: Nitrogen (flow rate 50 mL / min)
Temperature conditions 1st. Temperature rise Start temperature: 20 ° C., Temperature rise rate: 10 ° C./min, End temperature: 150 ° C., Holding time: None 1st. Temperature drop Temperature drop: 10 ° C./min, end temperature: 20 ° C., retention time: none 2nd. Temperature rise Temperature rise rate: 10 ° C / min, end temperature: 150 ° C
The measurement results are analyzed using data analysis software (TA-60, version 1.52) manufactured by Shimadzu Corporation.
The melting point is 2nd. The temperature at the top of the endothermic peak measured at elevated temperature is used.

In order to satisfy the above, it is preferable to contain a crystalline polyester resin as a binder resin.
Examples of the crystalline polyester resin include saturated aliphatic diol compounds having 2 to 12 carbon atoms as alcohol components, particularly 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,10- Decanediol, 1,12-dodecandiol and derivatives thereof, and a dicarboxylic acid having 2 to 12 carbon atoms or a saturated dicarboxylic acid having 2 to 12 carbon atoms having at least a double bond (C═C bond) as an acidic component Especially using fumaric acid, 1,4-butanedioic acid, 1,6-hexanedioic acid, 1,8-octanedioic acid, 1,10-decanedioic acid, 1,12 dodecanedioic acid and their derivatives Synthesized crystalline polyester is preferred.

  Among them, one kind of aliphatic alcohol component such as 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, in particular, in terms of reducing the difference between the endothermic peak temperature and the endothermic shoulder temperature, It is preferably composed of only one kind of aliphatic dicarboxylic acid component such as sebacic acid or 1,12-dodecanedioic acid.

  Further, as a method for controlling the crystallinity and softening point of the crystalline polyester resin, a trivalent or higher polyhydric alcohol such as glycerin as an alcohol component and a trivalent or higher polyvalent such as trimellitic anhydride as an acid component can be used during polyester synthesis. Examples thereof include a method of designing and using a non-linear polyester that has been subjected to condensation polymerization by adding a polyvalent carboxylic acid.

The molecular structure of the crystalline polyester resin of the present invention can be confirmed by X-ray diffraction, GC / MS, LC / MS, IR measurement, etc. in addition to NMR measurement by solution or solid.
The content of the crystalline polyester resin in the toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 3% by weight to 15% by weight, and more preferably 5% by weight to 10% by weight. preferable. When the content is 3% by weight or more, an effect on low-temperature fixability is sufficiently obtained, and when it is 15% by weight or less, heat resistance storage stability is hardly deteriorated, which is preferable.

  “Crystallinity” in the present invention is the ratio of the softening temperature measured by the Koka flow tester to the maximum peak temperature (melting point) of the heat of fusion measured by a differential scanning calorimeter (DSC) (softening temperature / The maximum melting temperature (melting heat) is 0.80 to 1.55, and is a property that softens sharply with heat. A polyester resin having this property is referred to as a “crystalline polyester resin”.

  The softening temperature of the resin and toner can be measured using a Koka flow tester (for example, CFT-500D (manufactured by Shimadzu Corporation)). While heating 1 g of resin as a sample at a heating rate of 6 ° C./min, a load of 1.96 MPa was applied by a plunger and extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. Plot, and let the temperature at which half of the sample flowed out be the softening temperature.

<< Releasing agent >>
There is no restriction | limiting in particular as said mold release agent, According to the objective, it can select suitably. For example, plant wax (carnauba wax, cotton wax, wood wax, rice wax, etc.), animal wax (beeswax, lanolin, etc.), mineral wax (ozokerite, cercin etc.), petroleum wax (paraffin, microcrystalline, petrolatum, etc.) ) Waxes and waxes; synthetic hydrocarbon waxes (Fischer-Tropsch wax, polyethylene wax, etc.), synthetic waxes other than natural waxes (esters, ketones, ethers, etc.); 1,2-hydroxystearic acid amide, Fatty acid amides such as stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbons; homopolymers or copolymers of polyacrylates such as poly (n-stearyl methacrylate) and poly (n-lauryl methacrylate) which are low molecular weight crystalline polymers ( Acrylic acid n- Crystalline polymer having a stearyl over long chain alkyl group in the side chain of ethyl methacrylate copolymer, etc.) and the like; and the like.

  Among these, Fischer-Tropsch wax, paraffin wax, microcrystalline wax, monoester wax, and rice wax are preferable because less unnecessary volatile organic compounds are generated during fixing.

  A commercial item can be used for the mold release agent. Examples of the microcrystalline wax include “HI-MIC-1045”, “HI-MIC-1070”, “HI-MIC-1080”, “HI-MIC-1090” manufactured by Nippon Seiki Co., Ltd. “Bsquare 180 White”, “Bsquare 195” manufactured by WAX Petrolife, “CAREVALAC WN-1442” manufactured by Cray Valley, and the like.

There is no restriction | limiting in particular as melting | fusing point of the said mold release agent, Although it can select suitably according to the objective, 60 to 100 degreeC is preferable and 65 to 90 degreeC is more preferable. When the melting point is 60 ° C. or more, even when stored at a high temperature of about 30 to 50 ° C., it is possible to suppress the exudation of the release agent from the toner base material and maintain good heat-resistant storage stability. When the temperature is 100 ° C. or lower, it is preferable because cold offset hardly occurs during fixing at a low temperature.
The melting point of the release agent is measured under the same DSC conditions as the melting point of the crystalline resin.

  The release agent is preferably present in a dispersed state in the toner base particles, and for this purpose, the release agent and the binder resin are preferably incompatible with each other. The method for finely dispersing the release agent in the toner base particles is not particularly limited and may be appropriately selected depending on the purpose. For example, the release agent is dispersed by applying a kneading shear force during toner production. The method etc. are mentioned.

  The dispersion state of the release agent can be confirmed by observing a thin film slice of toner particles with a transmission electron microscope (TEM). The dispersion diameter of the release agent is preferably small, but if it is too small, there are cases where bleeding during fixing is insufficient. Therefore, if the release agent can be confirmed at a magnification of 10,000, the release agent is present in a dispersed state. When the release agent cannot be confirmed at 10,000 times, even when finely dispersed, the dyeing at the time of fixing becomes insufficient.

  There is no restriction | limiting in particular as content in the said toner of the said mold release agent, Although it can select suitably according to the objective, 3 mass%-15 mass% are preferable, and 5 mass%-10 mass% are more preferable. . When the content is less than 3% by mass, the hot offset resistance may be deteriorated, which is not preferable. When the content exceeds 15% by mass, the exudation amount of the release agent during fixing tends to be excessive. This is not preferable because the heat-resistant storage stability tends to deteriorate.

<< Other ingredients >>
-Colorant-
There is no restriction | limiting in particular as a coloring agent used for the said toner, According to the objective, it can select suitably from a well-known coloring agent.
There is no restriction | limiting in particular as a color of the colorant of the said toner, According to the objective, it can select suitably. The toner can be at least one selected from black toner, cyan toner, magenta toner, and yellow toner, and each color toner can be obtained by appropriately selecting the type of colorant. preferable.

  Examples of black products include carbon blacks (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, copper, iron (CI pigment black 11), titanium oxide, and the like. And organic pigments such as aniline black (CI Pigment Black 1).

  Examples of the magenta color pigment include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 48: 1, 49, 50, 51, 52, 53, 53: 1, 54, 55, 57, 57: 1, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 150, 163, 177, 179, 184, 202, 206, 207, 209, 211, 269; I. Pigment violet 19; C.I. I. Bat red 1, 2, 10, 13, 15, 23, 29, 35, etc. are mentioned.

  Examples of the color pigment for cyan include C.I. I. Pigment Blue 2, 3, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 60; I. Bat Blue 6; C.I. I. Acid Blue 45 and copper phthalocyanine pigments having 1 to 5 phthalimidomethyl groups substituted on the phthalocyanine skeleton, Green 7, Green 36, and the like.

  Examples of the color pigment for yellow include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 55, 65, 73, 74, 83, 97, 110, 139, 151, 154, 155, 180, 185; I. Bat yellow 1, 3, 20, orange 36 and the like.

  The content of the colorant in the toner is preferably 1% by mass to 15% by mass, and more preferably 3% by mass to 10% by mass. When the content is less than 1% by mass, the coloring power of the toner may be reduced. When the content is more than 15% by mass, poor dispersion of the pigment in the toner may occur. The characteristics may be degraded.

  The colorant may be used as a master batch combined with a resin. Such a resin is not particularly limited, but it is preferable to use a binder resin or a resin having a structure similar to the binder resin from the viewpoint of compatibility with the binder resin.

  The masterbatch can be produced by applying a high shear force and mixing or kneading the resin and the colorant. At this time, it is preferable to add an organic solvent in order to enhance the interaction between the colorant and the resin. Also, the so-called flushing method is preferable in that the wet cake of the colorant can be used as it is, and there is no need to dry it. The flushing method is a method in which an aqueous paste containing water of a colorant is mixed or kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove water and the organic solvent. For mixing or kneading, for example, a high shear dispersion device such as a three-roll mill can be used.

-Charge control agent-
Further, in order to impart an appropriate charging ability to the toner, a charge control agent can be contained in the toner as necessary.
Any known charge control agent can be used as the charge control agent. Since the color tone may change when a colored material is used, a colorless or nearly white material is preferable. For example, a triphenylmethane dye, a molybdate chelate pigment, a rhodamine dye, an alkoxyamine, a quaternary ammonium salt (fluorine) Modified quaternary ammonium salts), alkylamides, phosphorus alone or compounds thereof, tungsten alone or compounds thereof, fluorine-based activators, metal salts of salicylic acid, metal salts of salicylic acid derivatives, and the like. These may be used individually by 1 type and may use 2 or more types together.

  The content of the charge control agent is determined by the toner production method including the type of the binder resin and the dispersion method, and is not uniquely limited. 01 mass%-5 mass% are preferable, and 0.02 mass%-2 mass% are more preferable. When the addition amount exceeds 5% by mass, 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 developer fluidity is reduced, and the image The density may be lowered, and if it is less than 0.01% by mass, the charge start-up property and the charge amount are not sufficient, and the toner image may be easily affected.

<< External additive >>
As the external additive, inorganic fine particles are used, and there is no particular limitation, and it can be appropriately selected from known ones according to the purpose. For example, silica fine particles, hydrophobized silica fine particles, metal oxides (for example, titania, alumina, tin oxide, antimony oxide, etc.) or their hydrophobized products, fluoropolymers and the like can be mentioned. Among these, hydrophobized silica fine particles, titania particles, and hydrophobized titania fine particles are preferable.
A fatty acid metal salt (for example, zinc stearate, aluminum stearate, etc.) can be used together with the inorganic fine particles.

  Examples of the hydrophobized silica fine particles include HDK H2000T, HDK H2000 / 4, HDK H2050EP, HVK21, HDK H1303VP (all manufactured by Clariant Japan); R972, R974, RX200, RY200, R202, R805, R812, NX90G (all manufactured by Nippon Aerosil Co., Ltd.) and the like.

  Examples of the titania fine particles include P-25 (manufactured by Nippon Aerosil Co., Ltd.); STT-30, STT-65C-S (both manufactured by Titanium Industry Co., Ltd.); TAF-140 (manufactured by Fuji Titanium Industry Co., Ltd.); MT-150W. , MT-500B, MT-600B, MT-150A (all of which are manufactured by Teica).

  Examples of the hydrophobized titanium oxide fine particles include T-805 (manufactured by Nippon Aerosil Co., Ltd.); STT-30A, STT-65S-S (both manufactured by Titanium Industry Co., Ltd.); TAF-500T, TAF-1500T (any Also, manufactured by Fuji Titanium Industry Co., Ltd.); MT-100S, MT-100T (both manufactured by Teika); IT-S (produced by Ishihara Sangyo Co., Ltd.).

There is no restriction | limiting in particular as content of the said external additive, Although it can select suitably according to the objective, 0.3 mass part-3.0 mass parts are preferable with respect to 100 mass parts of toner base particles. 0.5 parts by mass to 2.0 parts by mass is more preferable.
The total coverage of the external additive with respect to the toner base particles is not particularly limited, but is preferably 50% to 90%, and more preferably 60% to 80%.

<Toner production method>
The toner production method and materials in the present invention can be any known ones as long as they satisfy the conditions, and are not particularly limited. For example, the toner particles may be mixed in a kneading and pulverization method or an aqueous medium. There is a so-called chemical method of granulating.

  Examples of the chemical method include a suspension polymerization method, an emulsion polymerization method, a seed polymerization method, a dispersion polymerization method, etc., in which a monomer is used as a starting material; a resin or a resin precursor is dissolved in an organic solvent and the like in an aqueous medium. Dispersing or emulsifying dissolution suspension method; in the dissolution suspension method, an oil phase composition containing a resin precursor (reactive group-containing prepolymer) having a functional group capable of reacting with an active hydrogen group is contained in resin fine particles. A method of emulsifying or dispersing in an aqueous medium and reacting an active hydrogen group-containing compound and the reactive group-containing prepolymer in the aqueous medium (ester elongation method); from a resin or resin precursor and an appropriate emulsifier Phase inversion emulsification method in which water is added to the resulting solution for phase inversion; aggregation in which resin particles obtained by these methods are dispersed in an aqueous medium and granulated into particles of a desired size by heating and melting And the like. Among these, the toner obtained by the dissolution suspension method, the ester elongation method, and the aggregation method is preferable from the viewpoint of granulation properties (particle size distribution control, particle shape control, etc.), and the toner obtained by the ester elongation method is preferable. More preferred.

In the following, a detailed description of these production methods will be given.
The kneading and pulverizing method is, for example, a method of producing the toner base particles by pulverizing and classifying a toner material having at least a colorant, a binder resin, and a release agent melted and kneaded.
In the melt kneading, the toner materials are mixed, and the mixture is charged into a melt kneader and melt kneaded. As the melt kneader, for example, a uniaxial or biaxial continuous kneader or a batch kneader using a roll mill can be used. For example, a KTK type twin screw extruder manufactured by Kobe Steel, a TEM type extruder manufactured by Toshiba Machine Co., Ltd., a twin screw extruder manufactured by Casey Kay, a PCM type twin screw extruder manufactured by Ikegai Iron Works, and a Kneader manufactured by Buss Co., Ltd. are suitable. Used. This melt-kneading is preferably performed under appropriate conditions so as not to cause the molecular chains of the binder resin to be broken. Specifically, the melt kneading temperature is determined with reference to the softening point of the binder resin. If the temperature is too high, the cutting may be severe, and if the temperature is too low, the dispersion may not proceed.

In the pulverization, the kneaded product obtained by the kneading is pulverized. In this pulverization, it is preferable that the kneaded material is first coarsely pulverized and then finely pulverized. At this time, a method of pulverizing by colliding with a collision plate in a jet stream, pulverizing particles by colliding with each other in a jet stream, or pulverizing with a narrow gap between a mechanically rotating rotor and a stator is preferably used.
In the classification, the pulverized product obtained by the pulverization is classified and adjusted to particles having a predetermined particle diameter. The classification can be performed, for example, by removing the fine particle portion with a cyclone, a decanter, a centrifuge, or the like.
After the pulverization and classification are completed, the pulverized product is classified into an air stream by centrifugal force or the like, and toner base particles having a predetermined particle diameter can be produced.

In the dissolution suspension method, for example, an oil phase composition in which a toner composition containing a binder resin or a resin precursor, a colorant, and a release agent is dissolved or dispersed in an organic solvent is used as an aqueous medium. In this method, toner base particles are produced by dispersing or emulsifying the toner.
The toner used in the present invention includes a step of forming an oil phase composition containing at least a binder resin precursor made of a modified polyester resin, and the oil phase composition is dispersed in an aqueous medium to which a fine particle dispersant is added. And the step of forming an emulsified dispersion liquid and the step of removing the organic solvent from the emulsified dispersion liquid.

The organic solvent used for dissolving or dispersing the toner composition is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal of the solvent later.
Examples of the organic solvent include ester solvents such as ethyl acetate, butyl acetate, methoxybutyl acetate, methyl cellosolve acetate, ethyl cellosolve acetate, diethyl ether, tetrahydrofuran, dioxane, ethyl cellosolve, butyl cellosolve, and propylene glycol monomethyl. Ether solvents such as ether, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, di-n-butyl ketone, cyclohexanone, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, 2 -Alcohol solvents, such as ethyl hexyl alcohol and benzyl alcohol, and these 2 or more types of mixed solvents are mentioned.

In the dissolution suspension method, when the oil phase composition is dispersed or emulsified in an aqueous medium, an emulsifier or a dispersant may be used as necessary.
As the emulsifier or dispersant, known surfactants, water-soluble polymers and the like can be used. The surfactant is not particularly limited, and is an anionic surfactant (alkyl benzene sulfonic acid, phosphate ester, etc.), a cationic surfactant (quaternary ammonium salt type, amine salt type, etc.), an amphoteric surfactant (carbon carboxyl). Acid salt type, sulfate ester type, sulfonate salt type, phosphate ester salt type, etc.), nonionic surfactants (AO addition type, polyhydric alcohol type, etc.) and the like. One surfactant may be used alone, or two or more surfactants may be used in combination.

Examples of the water-soluble polymer include cellulose compounds (for example, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose and saponified products thereof), gelatin, starch, dextrin, gum arabic, chitin, chitosan. , Polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, polyethyleneimine, polyacrylamide, acrylic acid (salt) -containing polymer (sodium polyacrylate, potassium polyacrylate, ammonium polyacrylate, partially neutralized sodium hydroxide of polyacrylic acid) , Sodium acrylate-acrylic acid ester copolymer), sodium hydroxide of styrene-maleic anhydride copolymer ( Min) neutralized product water-soluble polyurethane (polyethylene glycol, reaction products of polycaprolactone diol with polyisocyanate and the like) and the like.
Moreover, said organic solvent, a plasticizer, etc. can also be used together as an auxiliary | assistant of emulsification or dispersion | distribution.

  The toner according to the present invention includes at least a binder resin, a binder resin precursor having a functional group capable of reacting with an active hydrogen group (reactive group-containing prepolymer), a colorant, and a release agent in a dissolution suspension method. The oil phase composition is dispersed or emulsified in an aqueous medium containing resin fine particles, the active hydrogen group-containing compound contained in the oil phase composition and / or the aqueous medium, and the reactive group-containing prepolymer, It is preferable that the toner base particles are granulated by a method of reacting the above (ester elongation method).

The resin fine particles can be formed using a known polymerization method, but is preferably obtained as an aqueous dispersion of resin fine particles. Examples of the method for preparing an aqueous dispersion of resin fine particles include the methods shown in the following (a) to (h).
(A) A method in which an aqueous dispersion of resin fine particles is directly prepared from a vinyl monomer as a starting material by any one of a suspension polymerization method, an emulsion polymerization method, a seed polymerization method and a dispersion polymerization method.
(B) After dispersing a precursor of polyaddition or condensation resin such as polyester resin, polyurethane resin, epoxy resin (monomer, oligomer, etc.) or a solvent solution thereof in an aqueous medium in an aqueous medium, A method of preparing an aqueous dispersion of resin fine particles by heating or adding a curing agent to cure.
(C) Polyaddition or condensation resin precursors (monomers, oligomers, etc.) such as polyester resins, polyurethane resins, and epoxy resins, or solvent solutions thereof (preferably liquids, which may be liquefied by heating). A method for preparing an aqueous dispersion of resin fine particles by dissolving a suitable emulsifier in the mixture and then adding water to effect phase inversion emulsification.
(D) A resin synthesized in advance by a polymerization reaction (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) is pulverized and classified using a mechanical rotary type or jet type fine pulverizer. A method of preparing an aqueous dispersion of resin fine particles by obtaining resin fine particles and then dispersing in water in the presence of an appropriate dispersant.
(E) Fine resin particles are formed by spraying a resin solution in which a resin synthesized in advance by a polymerization reaction (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) is dissolved in a solvent. Then, resin fine particles are dispersed in water in the presence of a suitable dispersant to prepare an aqueous dispersion of resin fine particles.
(F) A poor solvent is added to a resin solution prepared by previously dissolving a resin synthesized by a polymerization reaction (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent, or heated to a solvent in advance. By cooling the dissolved resin solution, the resin fine particles are precipitated, the solvent is removed to form the resin fine particles, and then the resin fine particles are dispersed in water in the presence of an appropriate dispersant to disperse the resin fine particles in water. A method for preparing a liquid.
(G) A resin solution obtained by dissolving a resin previously synthesized by a polymerization reaction (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent in the presence of an appropriate dispersant. A method of preparing an aqueous dispersion of resin fine particles by dispersing in a solvent and then removing the solvent by heating, decompression or the like.
(H) A suitable emulsifier is dissolved in a resin solution prepared by previously dissolving a resin synthesized by a polymerization reaction (for example, addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent, and then water To prepare an aqueous dispersion of resin fine particles by phase inversion emulsification.

  The volume average particle diameter of the resin fine particles is preferably 10 nm or more and 300 nm or less, and more preferably 30 nm or more and 120 nm or less. When the volume average particle size of the resin fine particles is less than 10 nm or more than 300 nm, the particle size distribution of the toner may be deteriorated.

The solid content concentration of the oil phase is preferably about 40 to 80%. If the concentration is too high, dissolution or dispersion becomes difficult, and the viscosity becomes high and difficult to handle. If the concentration is too low, the productivity of the toner decreases.
The toner composition other than the binder resin such as the colorant and the release agent, and the masterbatch thereof are individually dissolved or dispersed in an organic solvent, and then mixed with the binder resin solution or dispersion. May be.

As the aqueous medium, water alone may be used, but a solvent miscible with water may be used in combination. Examples of miscible solvents include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.) and the like.
The dispersion or emulsification method in the aqueous medium is not particularly limited, and known equipment such as a low-speed shearing type, a high-speed shearing type, a friction type, a high-pressure jet type, and an ultrasonic wave can be applied. Among these, the high-speed shearing method is preferable from the viewpoint of reducing the particle size of the particles. 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 temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 20 to 80 ° C.

  In order to remove the organic solvent from the obtained emulsified dispersion, there is no particular limitation, and a known method can be used. For example, the entire system is gradually raised while stirring the whole system under normal pressure or reduced pressure. A method of warming and completely evaporating and removing the organic solvent in the droplets can be employed.

  As a method of washing and drying the toner base particles dispersed in the aqueous medium, a known technique is used. That is, after solid-liquid separation with a centrifuge, a filter press, etc., the obtained toner cake is redispersed in ion-exchanged water at room temperature to about 40 ° C., and after pH adjustment with acid or alkali as necessary, After removing the impurities and surfactants by repeating the process of solid-liquid separation again and again, the toner powder is obtained by drying with an air dryer, circulating dryer, vacuum dryer, vibration fluid dryer, etc. . At this time, the fine particle component of the toner may be removed by centrifugation or the like, and a desired particle size distribution can be obtained using a known classifier after drying, if necessary.

  In the agglomeration method, for example, a toner base particle is produced by mixing and aggregating a resin fine particle dispersion comprising at least a binder resin, a colorant particle dispersion, and a release agent particle dispersion as necessary. is there. The resin fine particle dispersion is obtained by a known method such as emulsion polymerization, seed polymerization, phase inversion emulsification, and the like. The colorant particle dispersion and the release agent particle dispersion are obtained by a known wet dispersion method. It can be obtained by dispersing a colorant or a release agent in an aqueous medium.

For the control of the aggregation state, methods such as applying heat, adding a metal salt, and adjusting pH are preferably used.
There is no restriction | limiting in particular as said metal salt, The monovalent metal which comprises salts, such as sodium and potassium; The bivalent metal which comprises salts, such as calcium and magnesium; The trivalent metal which comprises salts, such as aluminum, etc. Is mentioned.

  Examples of the anion constituting the salt include chloride ion, bromide ion, iodide ion, carbonate ion, and sulfate ion. Among these, magnesium chloride, aluminum chloride, and complexes and multimers thereof are preferable. .

Also, heating between the agglomeration and after completion of the agglomeration can promote fusion between the resin fine particles, which is preferable from the viewpoint of toner uniformity. Furthermore, the shape of the toner can be controlled by heating. Normally, the toner becomes more spherical when heated further.
As the method for washing and drying the toner base particles dispersed in the aqueous medium, the above-described method and the like can be used.
Further, in order to improve the fluidity, storage stability, developability, and transferability of the toner, the coalesced particles are added to and mixed with the toner base particles produced as described above. Inorganic fine particles may be added and mixed.

  For mixing the additives, a general powder mixer is used, but it is preferable to equip a jacket or the like to adjust the internal temperature. In order to change the load history applied to the additive, the additive may be added midway or gradually. 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. Next, the toner is obtained by passing through a sieve of 250 mesh or more to remove coarse particles and aggregated particles.

(Developer)
The two-component developer of the present invention contains the toner, and at least a core material and a resin coating layer, and the resin coating layer includes a carrier containing a filler. According to the present invention, toner agglomeration is less likely to occur over time against agitation stress or the like by the developing means, and the occurrence of abnormal images is suppressed, and image density stability and transferability are favorably maintained. Thus, good and stable image quality can be obtained.

<Career>
As described above, the carrier in the present invention contains at least a core material and a resin coating layer, and the resin coating layer contains a filler. Details will be described below.

<< Core material (core particles) >>
The core material (hereinafter sometimes referred to as core particle) is not particularly limited as long as it is a core particle having magnetism, and can be appropriately selected according to the purpose. Examples thereof include ferromagnetic metals such as iron and cobalt; iron oxides such as magnetite, hematite and ferrite; and resin particles in which magnetic materials such as various alloys and compounds are dispersed in the resin. Among these, Mn-based ferrite, Mn-Mg-based ferrite, Mn-Mg-Sr-based ferrite and the like are preferable from the viewpoint of environmental considerations.

-Weight average particle diameter Dw of core particles-
The weight average particle diameter Dw of the core particles refers to the particle diameter at an integrated value of 50% in the particle size distribution of the core particles obtained by a laser diffraction or scattering method. There is no restriction | limiting in particular as the weight average particle diameter Dw of the said core particle, Although it can select suitably according to the objective, 10 micrometers-80 micrometers are preferable, and 20 micrometers-65 micrometers are more preferable.

The weight average particle diameter Dw of the core particles is measured by using a microtrac particle size distribution meter (HRA9320-X100, manufactured by Honeywell) as a particle diameter distribution (relationship between number frequency and particle diameter) of particles measured on a number basis. And measured under the conditions described below, and calculated using the following formula (I). Each channel represents a length for dividing the particle size range in the particle size distribution chart into measurement width units, and the lower limit value of the particle size stored in each channel is adopted as the representative particle size.
Dw = {1 / Σ (nD ₃ )} × {Σ (nD ₄ )} (I)
However, in said formula (I), D represents the representative particle size (micrometer) of the core particle which exists in each channel, and n represents the total number of the core particle which exists in each channel.

[Measurement condition]
[1] Particle size range: 100 μm to 8 μm
[2] Channel length (channel width): 2 μm
[3] Number of channels: 46
[4] Refractive index: 2.42

<< Resin coating layer >>
The resin coating layer (hereinafter sometimes referred to as a coating layer) contains at least a resin and contains other components such as a filler.

-Resin-
There is no restriction | limiting in particular as resin for forming the coating layer of a carrier, According to the objective, it can select suitably. For example, a crosslinkable copolymer containing polyolefin (for example, polyethylene, polypropylene, etc.) or a modified product thereof, polystyrene, acrylic resin, acrylonitrile, vinyl acetate, vinyl alcohol, vinyl chloride, vinyl carbazole, vinyl ether, etc .; consisting of an organosiloxane bond Silicone resins or modified products thereof (for example, modified products by alkyd resin, polyester resin, epoxy resin, polyurethane, polyimide, etc.); polyamide; polyester; polyurethane; polycarbonate; urea resin; melamine resin; benzoguanamine resin; Examples thereof include polyimide resins and derivatives thereof. These may be used individually by 1 type and may use 2 or more types together. Among these, a silicone resin is preferable.

  There is no restriction | limiting in particular as said silicone resin, According to the objective from the generally known silicone resin, it can select suitably, For example, straight silicone resin which consists only of organosiloxane bonds, alkyd, polyester , Silicone resins modified with epoxy, acrylic, urethane and the like.

  Examples of the straight silicone resin include KR271, KR272, KR282, KR252, KR255, KR152 (manufactured by Shin-Etsu Chemical Co., Ltd.), SR2400, SR2405, SR2406 (manufactured by Toray Dow Corning Silicone).

  Specific examples of the modified silicone resin include epoxy-modified product: ES-1001N, acrylic-modified silicone: KR-5208, polyester-modified product: KR-5203, alkyd-modified product: KR-206, and urethane-modified product: KR-. 305 (manufactured by Shin-Etsu Chemical Co., Ltd.), epoxy-modified product: SR2115, alkyd-modified product: SR2110 (manufactured by Toray Dow Corning Silicone), and the like.

  The silicone resin can be used alone, but a crosslinking reactive component, a charge amount adjusting component, and the like can be used at the same time. Examples of the crosslinking reactive component include a silane coupling agent. Examples of the silane coupling agent include methyltrimethoxysilane, methyltriethoxysilane, octyltrimethoxysilane, aminosilane coupling agent, and the like.

-Filler-
There is no restriction | limiting in particular as said filler, According to the objective, it can select suitably, For example, a conductive filler, a nonelectroconductive filler, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, it is preferable to contain a conductive filler and a non-conductive filler in the coating layer.

The conductive filler refers to a filler having a powder specific resistance value of 100 Ω · cm or less.
The said nonelectroconductive filler points out the filler whose powder specific resistance value exceeds 100 ohm * cm.
The powder specific resistance value of the filler is measured by a powder resistance measurement system (MCP-PD51, manufactured by Dia Instruments) and a resistivity meter (4-terminal 4-probe system, Loresta GP, manufactured by Mitsubishi Chemical Analytech). Can be measured under the conditions of a sample of 1.0 g, an electrode interval of 3 mm, a sample radius of 10.0 mm, and a load of 20 kN.

--Conductive filler--
There is no restriction | limiting in particular as said electroconductive filler, According to the objective, it can select suitably. For example, a conductive filler formed as a layer of tin dioxide or indium oxide on a substrate such as aluminum oxide, titanium oxide, zinc oxide, barium sulfate, silicon oxide, zirconium oxide, etc .; a conductive filler formed using carbon black, etc. It is done. Among these, a conductive filler containing aluminum oxide, titanium oxide, and barium sulfate is preferable. More preferred is aluminum oxide.

--Non-conductive filler--
There is no restriction | limiting in particular as said nonelectroconductive filler, According to the objective, it can select suitably. For example, a non-conductive filler formed using aluminum oxide, titanium oxide, barium sulfate, zinc oxide, silicon dioxide, zirconium oxide, or the like can be given. Among these, non-conductive fillers containing aluminum oxide, titanium oxide, and barium sulfate are preferable. More preferred is aluminum oxide.

<Carrier manufacturing method>
There is no restriction | limiting in particular as a manufacturing method of the said carrier, Although it can select suitably according to the objective, The said resin and the said filler are contained in the surface of the said core particle using a fluid bed type coating apparatus. The method of manufacturing by apply | coating a coating layer forming solution is preferable. In addition, when apply | coating the said coating layer forming solution, you may advance condensation of the resin contained in the said coating layer, and after apply | coating the said coating layer forming solution, condensation of the resin contained in the said coating layer You may proceed.
There is no restriction | limiting in particular as the condensation method of the said resin, According to the objective, it can select suitably, For example, the method etc. which give a heat | fever, light, etc. to the said coating layer formation solution, etc. are mentioned. .

-Weight average particle diameter Dw of carrier-
The weight average particle diameter Dw of the carrier refers to the particle diameter at an integrated value of 50% in the particle size distribution of the core particles obtained by a laser diffraction / scattering method. There is no restriction | limiting in particular as the weight average particle diameter Dw of the said carrier, Although it can select suitably according to the objective, 10 micrometers-80 micrometers are preferable, and 20 micrometers-65 micrometers are more preferable.

For the measurement of the weight average particle diameter Dw of the carrier, the particle size distribution (relationship between the number frequency and the particle diameter) of the particles measured on the basis of the number is used using a Microtrac particle size distribution meter (HRA9320-X100, manufactured by Honeywell). Measured under the conditions described below and calculated using the following formula (II). Each channel represents a length for dividing the particle size range in the particle size distribution chart into measurement width units, and the lower limit value of the particle size stored in each channel is adopted as the representative particle size.
Dw = {1 / Σ (nD ₃ )} × {Σ (nD ₄ )} (II)
However, in said formula (II), D represents the representative particle size (micrometer) of the carrier which exists in each channel, and n represents the total number of the carriers which exist in each channel.

〔Measurement condition〕
[1] Particle size range: 100 μm to 8 μm
[2] Channel length (channel width): 2 μm
[3] Number of channels: 46
[4] Refractive index: 2.42

  When the developer is a two-component developer, the mixing ratio of the toner and the carrier in the two-component developer is preferably such that the mass ratio of the toner to the carrier is 2.0 to 12.0% by mass, More preferably, it is 2.5-10.0 mass%.

(Developer storage unit)
The developer accommodating unit in the present invention refers to a unit in which a developer is accommodated in a unit having a function of accommodating a developer.
Here, as an aspect of the developer accommodating unit, there are a container containing a developer, a developing device, and a process cartridge.
A container containing a developer means a container containing a developer.
The developing unit is a unit having a means for containing and developing a developer.
The process cartridge is a cartridge in which at least the image carrier and the developing unit are integrated and detachable from the image forming apparatus. At least one of the charging unit, the exposure unit, and the cleaning unit, and the image carrier and the developing unit may be integrated.

(Image forming method and image forming apparatus)
The image forming method according to the present invention can be performed by developing an electrostatic latent image using the developer of the present invention and an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier. A development step for forming a visual image, a transfer step for transferring the visible image onto a recording medium, and a fixing step for fixing the transfer image transferred onto the recording medium. Furthermore, it has other processes suitably selected as necessary, for example, a static elimination process, a cleaning process, a recycling process, a control process, and the like.

  An image forming apparatus according to the present invention includes an electrostatic latent image bearing member, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image bearing member, and the developer according to the present invention. Developing means for developing a latent image by developing an electrostatic latent image, transfer means for transferring the visible image onto a recording medium, and fixing means for fixing the transferred image transferred onto the recording medium Have. Furthermore, other means appropriately selected as necessary, for example, a static elimination means, a cleaning means, a recycling means, a control means and the like are provided. Details will be described below.

-Electrostatic latent image forming step and electrostatic latent image forming means-
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier.
The electrostatic latent image carrier (sometimes referred to as “electrophotographic photosensitive member” or “photosensitive member”) is not particularly limited in terms of material, shape, structure, size, etc. Although it can be selected as appropriate, the shape thereof is preferably a drum shape, and examples of the material thereof include inorganic photoreceptors such as amorphous silicon and selenium, organic photoreceptors (OPC) such as polysilane and phthalopolymethine, and the like. Is mentioned. Among these, an organic photoreceptor (OPC) is preferable in that a higher definition image can be obtained.

The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then performing imagewise exposure, and is performed by electrostatic latent image forming means. Can do.
The electrostatic latent image forming unit includes, for example, a charging unit (charger) that uniformly charges the surface of the electrostatic latent image carrier, and an exposure that exposes the surface of the electrostatic latent image carrier imagewise. Means (exposure unit).

The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roll, brush, film, rubber blade, etc. And non-contact chargers utilizing corona discharge such as corotrons and corotrons.
The charger is preferably one that is arranged in contact or non-contact with the electrostatic latent image carrier and charges the surface of the electrostatic latent image carrier by applying a direct current and an alternating voltage.
Further, the charger is a charging roller disposed in a non-contact proximity to the electrostatic latent image carrier via a gap tape, and the electrostatic latent image is carried by applying a direct current and an alternating voltage to the charging roller. Those that charge the body surface are preferred.

The exposure can be performed, for example, by exposing the surface of the latent electrostatic image bearing member imagewise using the exposure device.
The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger so as to form an image to be formed, and is appropriately selected according to the purpose. For example, 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.
In the present invention, a back light system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier may be employed.

-Development process and development means-
The developing step is a step of developing the electrostatic latent image with the toner to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner, and can be performed by the developing unit.
The developing unit preferably includes, for example, at least a developing unit that accommodates the toner and can apply the toner to the electrostatic latent image in a contact or non-contact manner, and includes a toner-containing container. Etc. are more preferable.

The developing device may be a monochromatic developing device or a multi-color developing device, and has, for example, an agitator that frictionally agitates and charges the toner and a rotatable magnet roller. A thing etc. are mentioned suitably.
In the developing device, for example, 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 electrostatic latent image carrier (photoconductor), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted. It moves to the surface of the electrostatic latent image carrier (photoconductor) by force. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrostatic latent image carrier (photoconductor).

-Transfer process and transfer means-
The transfer step is a step of transferring the visible image onto a recording medium. After the primary transfer of the visible image onto the intermediate transfer member using an intermediate transfer member, the visible image is transferred onto the recording medium. A primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably full color toner as the toner, and a composite transfer image; A mode including a secondary transfer step of transferring the transfer image onto the recording medium is more preferable.
The transfer can be performed, for example, by charging the latent electrostatic image bearing member (photoconductor) of the visible image using a transfer charger, and can be performed by the transfer unit. The transfer means includes 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. Embodiments are preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.

The transfer means (the primary transfer means and the secondary transfer means) is a transfer for peeling and charging the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. It is preferable to have at least a vessel. The number of the transfer means may be one, or two or more.
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 is not particularly limited and can be appropriately selected from known recording media (recording paper).

-Fixing process and fixing means-
The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed each time the developer of each color is transferred to the recording medium, or the developer of each color. On the other hand, it may be carried out at the same time in a state where these are laminated.
There is no restriction | limiting in particular as said fixing device, Although it can select suitably according to the objective, A well-known heating-pressing means is suitable. Examples of the heating and pressing means include a combination of a heating roller and a pressing roller, a combination of a heating roller, a pressing roller, and an endless belt.
The fixing device includes a heating body including a heating element, a film in contact with the heating body, and a pressure member in pressure contact with the heating body through the film, and the film and the pressure member It is preferably a unit that heats and fixes a recording medium on which an unfixed image is formed. The heating in the heating and pressing means is usually preferably 80 ° C to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

-Other processes and other means-
The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrostatic latent image carrier, and can be suitably performed by a neutralization unit.
The neutralization means is not particularly limited, and may be appropriately selected from known neutralizers as long as it can apply a neutralization bias to the electrostatic latent image carrier. Preferably mentioned.

The cleaning step is a step of removing the toner remaining on the electrostatic latent image carrier and can be suitably performed by a cleaning unit.
The cleaning means is not particularly limited, and may be appropriately selected from known cleaners as long as the toner remaining on the electrostatic latent image carrier can be removed. For example, a magnetic brush cleaner Suitable examples include electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.
The recycling step is a step of recycling the toner removed by the cleaning step to the developing unit, and can be suitably performed by the recycling unit. There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

The control step is a step of controlling each step, and each step can be suitably performed by a control means.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

  FIG. 1 shows a first example of an image forming apparatus of the present invention. The image forming apparatus 100 </ b> A includes a photosensitive drum 10, a charging roller 20, an exposure device, a developing device 40, an intermediate transfer belt 50, a cleaning device 60 having a cleaning blade, and a static elimination lamp 70.

  The intermediate transfer belt 50 is an endless belt stretched by three rollers 51 arranged on the inner side, and can move in the direction of the arrow in the figure. A part of the three rollers 51 also functions as a transfer bias roller that can apply a transfer bias (primary transfer bias) to the intermediate transfer belt 50. Further, a cleaning device 90 having a cleaning blade is disposed in the vicinity of the intermediate transfer belt 50. Further, a transfer roller 80 capable of applying a transfer bias (secondary transfer bias) for transferring the toner image to the transfer paper 95 is disposed opposite to the intermediate transfer belt 50.

  Further, around the intermediate transfer belt 50, a corona charging device 58 for applying a charge to the toner image transferred to the intermediate transfer belt 50 is connected to the photosensitive drum 10 with respect to the rotation direction of the intermediate transfer belt 50. It is disposed between the contact portion of the intermediate transfer belt 50 and the contact portion of the intermediate transfer belt 50 and the transfer paper 95.

  The developing device 40 includes a developing belt 41 and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C provided around the developing belt 41. Each color developing unit 45 includes a developer container 42, a developer supply roller 43, and a developing roller (developer carrier) 44. The developing belt 41 is an endless belt stretched by a plurality of belt rollers, and can move in the direction of the arrow in the figure. Further, a part of the developing belt 41 is in contact with the photosensitive drum 10.

  Next, a method for forming an image using the image forming apparatus 100A will be described. First, the charging roller 20 is used to uniformly charge the surface of the photosensitive drum 10, and then the exposure light L is exposed to the photosensitive drum 10 using an exposure device (not shown) to form an electrostatic latent image. Form. Next, the electrostatic latent image formed on the photosensitive drum 10 is developed with the toner supplied from the developing device 40 to form a toner image. Further, after the toner image formed on the photosensitive drum 10 is transferred (primary transfer) onto the intermediate transfer belt 50 by the transfer bias applied from the roller 51, the transfer bias applied from the transfer roller 80 is used. Then, it is transferred (secondary transfer) onto the transfer paper 95. On the other hand, the photosensitive drum 10 on which the toner image is transferred to the intermediate transfer belt 50 is discharged by the discharging lamp 70 after the toner remaining on the surface is removed by the cleaning device 60.

  FIG. 2 shows a second example of the image forming apparatus used in the present invention. In the image forming apparatus 100B, the black developing unit 45K, the yellow developing unit 45Y, the magenta developing unit 45M, and the cyan developing unit 45C are arranged directly facing each other around the photosensitive drum 10 without providing the developing belt 41. Other than that, the configuration is the same as that of the image forming apparatus 100A.

  FIG. 3 shows a third example of the image forming apparatus used in the present invention. The image forming apparatus 100 </ b> C is a tandem type color image forming apparatus, and includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.

  The intermediate transfer belt 50 provided at the center of the copying apparatus main body 150 is an endless belt stretched around three rollers 14, 15 and 16, and can move in the direction of the arrow in the figure. In the vicinity of the roller 15, a cleaning device 17 having a cleaning blade for removing toner remaining on the intermediate transfer belt 50 on which the toner image has been transferred onto the recording paper is disposed. The image forming units 120Y, 120C, 120M, and 120K for yellow, cyan, magenta, and black are juxtaposed along the conveying direction while facing the intermediate transfer belt 50 stretched by the rollers 14 and 15.

  An exposure device 21 is disposed in the vicinity of the image forming unit 120. Further, the secondary transfer belt 24 is disposed on the side of the intermediate transfer belt 50 opposite to the side on which the image forming unit 120 is disposed. The secondary transfer belt 24 is an endless belt stretched around a pair of rollers 23, and the recording paper and the intermediate transfer belt 50 conveyed on the secondary transfer belt 24 are between the rollers 16 and 23. Can touch.

  Further, in the vicinity of the secondary transfer belt 24, a fixing device 25 is provided with a fixing belt 26 that is an endless belt stretched between a pair of rollers, and a pressure roller 27 that is arranged to be pressed against the fixing belt 26. Is arranged. A sheet reversing device 28 for reversing the recording paper when an image is formed on both sides of the recording paper is disposed in the vicinity of the secondary transfer belt 24 and the fixing device 25.

  Next, a method for forming a full-color image using the image forming apparatus 100C will be described. First, a color document is set on the document table 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and a color document is set on the contact glass 32 of the scanner 300 to automatically convey the document. The device 400 is closed. When the start switch is pressed, when an original is set on the automatic document feeder 400, after the original is conveyed and moved onto the contact glass 32, on the other hand, when the original is set on the contact glass 32, Immediately, the scanner 300 is driven, and the first traveling body 33 including the light source and the second traveling body 34 including the mirror travel. At this time, the reflected light from the original surface of the light irradiated from the first traveling body 33 is reflected by the second traveling body 34 and then received by the reading sensor 36 via the imaging lens 35, whereby the original is received. It is read and image information of black, yellow, magenta and cyan is obtained.

  The image information for each color is transmitted to the image forming unit 120 for each color, and a toner image for each color is formed. As shown in FIG. 4, each color image forming unit 120 includes a photosensitive drum 10, a charging roller 160 that uniformly charges the photosensitive drum 10, and the image information of each color, respectively. An exposure device that exposes the exposure light L to form an electrostatic latent image of each color; a developing device 61 that develops the electrostatic latent image with a developer of each color to form a toner image of each color; A transfer roller 62 for transferring onto the transfer belt 50, a cleaning device 63 having a cleaning blade, and a static elimination lamp 64 are provided.

  The toner images of the respective colors formed by the image forming units 120 of the respective colors are sequentially transferred (primary transfer) onto the intermediate transfer body 50 that is stretched and moved by the rollers 14, 15, and 16, and superimposed to form a composite toner image. It is formed.

  On the other hand, in the paper feed table 200, one of the paper feed rollers 142 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 145. 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 is rotated to feed out the recording paper on the manual feed tray 54, separated one by one by the separation roller 52, guided to the manual paper 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 in order to remove paper dust from the recording paper. Next, by rotating the registration roller 49 in synchronization with the composite toner image formed on the intermediate transfer belt 50, the recording paper is sent between the intermediate transfer belt 50 and the secondary transfer belt 24, and the composite toner image is sent. The toner image is transferred onto the recording paper (secondary transfer). The toner remaining on the intermediate transfer belt 50 to which the composite toner image has been transferred is removed by the cleaning device 17.

  The recording paper on which the composite toner image has been transferred is conveyed by the secondary transfer belt 24 and then the composite toner image is fixed by the fixing device 25. Next, the conveyance path of the recording paper is switched by the switching claw 55, and the recording paper is discharged onto the paper discharge tray 57 by the discharge roller 56. Alternatively, the recording path of the recording paper is switched by the switching claw 55, reversed by the sheet reversing device 28, an image is similarly formed on the back side, and then discharged onto the discharge tray 57 by the discharge roller 56. .

  According to the image forming method and the image forming apparatus of the present invention, high-quality images can be provided over a long period of time.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to the following Example. In the description in the examples, [%] represents% by weight, and “part” represents “part by mass”.

(Synthesis Example A-1)
-Synthesis of polyester resin A-1-
In a reaction vessel equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, bisphenol A propylene oxide 2 mol adduct and bisphenol A propylene oxide 3 mol adduct in a molar ratio of 80/20, isophthalic acid and adipine The acid was adjusted to a molar ratio of 70/30, OH / COOH = 1.33, and reacted with 500 ppm of titanium tetraisopropoxide at 230 ° C. for 10 hours at normal pressure. Next, 26 parts of benzoic acid was added to the reaction vessel and reacted at a reduced pressure of 10 mmHg to 15 mmHg for 5 hours. Then, 11 parts of trimellitic anhydride was added to the reaction vessel and reacted at 180 ° C. and normal pressure for 3 hours. -1] was obtained.

(Synthesis Example A-2)
-Synthesis of polyester resin A-2-
[Polyester resin A-2] was obtained in the same manner as in Synthesis Example 1 except that the molar ratio of isophthalic acid to adipic acid was changed from 70/30 to 50/50 in Synthesis Example 1.

(Synthesis Example A-3)
-Synthesis of polyester resin A-3-
In Synthesis Example 1, [Polyester Resin A-3] was obtained in the same manner as in Synthesis Example 1 except that the amount of benzoic acid charged was changed from 26 parts to 21 parts.

(Synthesis Example A-4)
-Synthesis of polyester resin A-4-
In Synthesis Example 1, [Polyester Resin A-4] was obtained in the same manner as in Synthesis Example 1 except that the amount of benzoic acid charged was changed from 26 parts to 16 parts.

(Synthesis Example A-5)
-Synthesis of polyester resin A-5-
In a reaction vessel equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, bisphenol A propylene oxide 2 mol adduct and bisphenol A propylene oxide 3 mol adduct in a molar ratio of 90/10, isophthalic acid and adipine The acid was adjusted to a molar ratio of 90/10, OH / COOH = 1.33, and reacted with 500 ppm of titanium tetraisopropoxide at 230 ° C. for 10 hours at normal pressure. Subsequently, after reacting under reduced pressure of 10 mmHg to 15 mmHg for 5 hours, 11 parts of trimellitic anhydride was added to the reaction vessel, and reacted at 180 ° C. and normal pressure for 3 hours to obtain [Polyester Resin A-5].

(Synthesis Example B)
-Synthesis of polyester resin B-
A reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe was charged with sebacic acid, adipic acid and 1,4-butanediol at a molar ratio of 40/9/51, and titanium dihydroxybis (triethanol as a condensation catalyst). 0.25 parts of (aminate) was added to 100 parts of the monomer component and reacted for 4 hours while distilling off the water produced at 180 ° C. under a nitrogen stream. Next, while gradually raising the temperature to 225 ° C., the reaction was carried out for 2.5 hours while distilling off the generated water and 1,4-butanediol in a nitrogen stream, and then the weight average molecular weight was further reduced under a reduced pressure of 5 to 20 mmHg. The reaction was continued until (Mw) reached about 1000.
218 parts of the obtained crystalline resin was transferred into a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, and 250 parts of ethyl acetate, 40 parts of hexamethylene diisocyanate (HDI) and 25 parts of maleic anhydride were added, The reaction was carried out at 80 ° C. for 5 hours under a nitrogen stream. Subsequently, ethyl acetate was distilled off under reduced pressure to obtain [Polyester Resin B]. The melting point of the obtained polyester resin B was 55 ° C.

(Synthesis Example C)
-Synthesis of polyester prepolymer-
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen insertion tube, 720 parts by mass of bisphenol A ethylene oxide 2 mol adduct, 90 parts by mass of bisphenol A propylene oxide 2 mol adduct, 290 parts by mass of terephthalic acid, and tetrabutoxy titanate 1 A mass part was added, and the reaction was carried out for 8 hours while distilling off the generated water at 230 ° C. and normal pressure under a nitrogen stream. Subsequently, it was made to react under reduced pressure of 10-15 mmHg for 7 hours, and [intermediate polyester] was obtained. [Intermediate polyester] had a weight average molecular weight (Mw) of 9,300.
Next, put 400 parts by mass of the obtained [intermediate polyester], 95 parts by mass of isophorone diisocyanate, and 500 parts by mass of ethyl acetate in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen insertion pipe. The mixture was reacted at 80 ° C. for 8 hours to obtain a 50% by mass ethyl acetate solution of [polyester prepolymer] having an isocyanate group at the terminal. [Polyester prepolymer] had a free isocyanate mass% of 1.47%.

-Preparation of masterbatch (MB)-
Add 1,200 parts of water, 540 parts of carbon black (Printex35, manufactured by Dexa, DBP oil absorption = 42 mL / 100 mg, pH = 9.5), and 1,200 parts of [Polyester resin A-1], and add Henschel mixer ( (Mitsui Mining Co., Ltd.), and the mixture was kneaded at 150 ° C. for 30 minutes using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain [Masterbatch 1].

Example 1
<Preparation of toner>
-Raw material composition-
Binder resin 1: [Polyester resin A-1] 94 parts Binder resin 2: [Polyester resin B] 0 part Colorant: [Masterbatch 1] 7 parts Charge control agent: Bontron E-84 (made by Orient Chemical Industries, Ltd.) ) 1 part Release agent: Carnauba wax (WA-05, manufactured by Celalica Noda) 6 parts

  The toner powder raw material was thoroughly mixed with a super mixer (SMV-200, manufactured by Kawata) to obtain a toner powder raw material mixture. This toner powder raw material mixture was supplied to a raw material supply hopper of a Busco kneader (TCS-100, manufactured by Buss Co.), and kneaded at a supply amount of 120 kg / h. The obtained kneaded product is rolled and cooled with a double belt cooler, coarsely pulverized with a hammer mill, finely pulverized with a jet airflow pulverizer (I-20 jet mill, manufactured by Nippon Pneumatic Co., Ltd.), and a wind classifier. Fine powder classification was performed using a DS-20 / DS-10 classifier (manufactured by Nippon Pneumatic Co., Ltd.) to prepare [Toner Base Particle 1].

-Mixed-
Hydrophobic silica (HDK-2000, manufactured by Wacker Chemie) is added to 100 parts of the base particles based on [Toner Base Particle 1], and a 20 L Henschel mixer (Mitsui Mining Co., Ltd.) is used. Mixing was performed at a peripheral speed of 33 m / s for 5 minutes. The above was air sieved with a 500 mesh sieve to obtain [Toner 1].

(Example 2)
In Example 1, [Toner 2] was obtained in the same manner as in Example 1 except that mixing was performed at a peripheral speed of 20 m / s for 3 minutes.

Example 3
[Toner 3] is the same as Example 1 except that [Polyester resin A-2] is used as binder resin 1 in Example 1 and the mixing conditions are mixed for 3 minutes at a peripheral speed of 20 m / s. Got.

Example 4
In Example 1, except that [Polyester resin A-2] was used as binder resin 1, the number of parts added to hydrophobic silica was 2.3 parts, and the mixing conditions were mixed for 10 minutes at a peripheral speed of 33 m / s. Obtained [Toner 4] in the same manner as in Example 1.

(Example 5)
[Toner 5] is the same as Example 1 except that [Polyester resin A-3] is used as binder resin 1 in Example 1 and mixing is performed at a peripheral speed of 33 m / s for 10 minutes. Got.

(Example 6)
[Toner 6] was obtained in the same manner as in Example 1, except that [Polyester Resin A-3] was used as Binder Resin 1 and the number of added parts of hydrophobic silica was 1.3 parts. It was.

(Example 7)
[Toner 7] was obtained in the same manner as in Example 1 except that [Polyester Resin A-4] was used as Binder Resin 1 in Example 1.

(Example 8)
[Toner 8] is the same as Example 1 except that 87 parts of [Polyester resin A-1] is used as binder resin 1 and 7 parts of [Polyester resin B] is used as binder resin 2 in Example 1. Got.

Example 9
In Example 1, 87 parts of [Polyester resin A-4] is used as binder resin 1 and 7 parts of [Polyester resin B] is used as binder resin 2 and mixed at a peripheral speed of 40 m / s for 10 minutes. Except that, [Toner 9] was obtained in the same manner as in Example 1.

(Example 10)
-Preparation of release agent dispersion-
70 parts by weight of Carnauba wax (WA-05, manufactured by Celerica Noda), 140 parts by weight of [Polyester Resin A-1], and 290 parts by weight of ethyl acetate are placed in a container equipped with a stirring bar and a thermometer. The temperature was raised to 75 ° C. and held at 75 ° C. for 1.5 hours, then cooled to 30 ° C. in 1 hour, and using a bead mill (Ultra Visco Mill, manufactured by IMEX), the liquid feeding speed was 5 kg / hr, the disk circumference Dispersion was carried out under the conditions of a filling rate of 6 m / sec, 0.5% zirconia beads at 80% by volume, and 3 passes to obtain [release agent dispersion].

-Production of oil phase 1-
In a container equipped with a thermometer and a stirrer, 113 parts by weight of [Polyester Resin A-1], 88 parts by weight of [Mold Release Agent Dispersion], 42 parts by weight of [Masterbatch 1], and 150 parts by weight of ethyl acetate are put. After pre-dispersing with a stirrer, the mixture was stirred with a TK homomixer (manufactured by Tokushu Kika Co., Ltd.) at a rotational speed of 5,000 rpm, and uniformly dissolved and dispersed to obtain [Oil Phase 1].

-Production of aqueous dispersion of resin fine particles-
In a reaction vessel equipped with a stirrer and a thermometer, 600 parts by mass of water, 120 parts by mass of styrene, 100 parts by mass of methacrylic acid, 45 parts by mass of butyl acrylate, sodium salt of alkylallylsulfosuccinate (Eleminol JS-2, Sanyo Chemical Industries) 10 parts by mass) and 1 part by mass of ammonium persulfate were charged and stirred for 20 minutes at 400 rpm, and a white emulsion was obtained. This emulsion was heated to raise the system temperature to 75 ° C. and reacted for 6 hours. Further, 30 parts by mass of a 1% ammonium persulfate aqueous solution was added and aged at 75 ° C. for 6 hours to obtain [Aqueous dispersion of resin fine particles]. The volume average particle diameter of the particles contained in this [resin fine particle aqueous dispersion] was 60 nm, the weight average molecular weight of the resin component was 140,000, and Tg was 73 ° C.

-Preparation of aqueous phase-
990 parts by mass of water, 83 parts by mass of an aqueous dispersion of resin fine particles, 37 parts by mass of a 48.5% by mass aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries), and 90 parts by mass of ethyl acetate Parts were mixed and stirred to obtain [Aqueous phase].

-Emulsification or dispersion-
To 393 parts by mass of [Oil Phase 1], 58 parts by mass of an ethyl acetate solution of [Polyester Prepolymer] and 3.5 parts by mass of a 50% by mass ethyl acetate solution of isophoronediamine were added, and a TK homomixer (specialized mechanized) The product was stirred at a rotational speed of 5,000 rpm and uniformly dissolved and dispersed to obtain [Oil Phase 1 ′]. Next, 550 parts by mass of [Aqueous Phase] is put in another container in which a stirrer and a thermometer are set, and while stirring at 11,000 rpm with a TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.), [Oil Phase] 1 '] was added and emulsified for 1 minute to obtain [Emulsified slurry 1].

-Solvent removal-Washing-Drying-
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and the solvent was removed at 30 ° C. for 8 hours to obtain [Slurry 1]. The obtained [Slurry 1] was kept at 40 ° C. for 4 hours, then filtered under reduced pressure, and the following washing treatment was performed.
(1) 100 parts by mass of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (5 minutes at a rotation speed of 6,000 rpm), and then filtered.
(2) After adding 100 parts by mass of ion-exchanged water to the filter cake of (1) and mixing with a TK homomixer (5 minutes at a rotation speed of 6,000 rpm), 1% by mass hydrochloric acid is about pH 3.3 with stirring. The mixture was added until the mixture was stirred, and stirring was continued for 1 hour in that state, followed by filtration.
(3) Add 300 parts by mass of ion-exchanged water to the filter cake of (2) above, mix with a TK homomixer (5 minutes at 6,000 rpm) and then filter twice to obtain filter cake 1 It was.
The obtained filter cake 1 was dried at 40 ° C. for 48 hours in a circulating dryer. Thereafter, the mixture was sieved with a 75 μm mesh to produce [Toner Base Particles 10].
The obtained [Toner Base Particle 10] was mixed and air sieved under the same conditions as in Example 1 to obtain [Toner 10].

(Example 11)
In Example 10, [Toner 11] was obtained in the same manner as in Example 10 except that mixing was performed at a peripheral speed of 20 m / s for 3 minutes.

(Example 12)
[Toner 12] was obtained in the same manner as in Example 1 except that [Polyester resin A-4] was used as binder resin 1 in Example 10.

(Example 13)
-Preparation of crystalline polyester dispersion-
100 parts by mass of [Polyester resin B] and 400 parts by mass of ethyl acetate were taken in a metal 2 L container, heated and dissolved at 70 ° C., and then cooled to 20 ° C. at a rate of 20 ° C./min in an ice water bath. When the cooling liquid was observed, it was confirmed that the crystalline polyester was recrystallized. After cooling, 100 parts by mass of [Polyester resin A-1] is dissolved in the dispersion, and using a bead mill (Ultra Visco Mill, manufactured by IMEX Co., Ltd.), the liquid feeding speed is 10 kg / hr, the disk peripheral speed is 6 m / sec, and 0.5 mm. Zirconia beads were filled at 80% by volume and dispersed under conditions of 5 passes to obtain [Crystalline Polyester Dispersion].

-Production of oil phase 2-
In a container equipped with a thermometer and a stirrer, 100 parts by weight of [Polyester Resin A-1], 88 parts by weight of [Releasing Agent Dispersion], 20 parts by weight of [Crystalline Polyester Dispersion], [Masterbatch 1] 42 Part by weight, 150 parts by weight of ethyl acetate, pre-dispersed with a stirrer, then stirred with a TK homomixer (manufactured by Tokushu Kika Co., Ltd.) at a rotational speed of 5,000 rpm, and uniformly dissolved and dispersed [Oil phase 2] was obtained.
Otherwise, [Toner 13] was obtained in the same manner as in Example 10.

(Example 14)
[Toner 14] was obtained in the same manner as in Example 13 except that [Polyester resin A-4] was used in Example 13 and mixing was performed at a wind speed of 40 m / s for 10 minutes.

(Comparative Example 1)
[Toner 15] was obtained in the same manner as in Example 1 except that [Polyester resin A-5] was used as binder resin 1 in Example 1.

(Comparative Example 2)
In [Example 1], [Toner 16] was obtained in the same manner as in Example 1 except that the number of parts added to the hydrophobic silica was 2.3 and the mixing conditions were mixed at a peripheral speed of 20 m / s for 3 minutes.

(Comparative Example 3)
In [Example 1], [Toner 17] was obtained in the same manner as in Example 1 except that the number of parts added to the hydrophobic silica was 2.3 and mixing was performed for 10 minutes at a peripheral speed of 40 m / s.

(Comparative Example 4)
In [Example 1], [Toner 18] was obtained in the same manner as in Example 1 except that the number of parts added to the hydrophobic silica was 2.3 and the mixing conditions were mixed at a peripheral speed of 20 m / s for 3 minutes.

(Comparative Example 5)
In [Example 1], [Toner 19] was obtained in the same manner as Example 1 except that the number of parts added to hydrophobic silica was 1.3 and the mixing condition was mixed at a peripheral speed of 20 m / s for 3 minutes.

(Comparative Example 6)
[Toner 20] was obtained in the same manner as in Example 10, except that [Polyester Resin A-5] was used as the binder resin in Example 10.

(Measurement)
<Preparation of carrier core material 1>
MnCO ₃ and Fe ₂ O ₃ powder as magnetic materials were weighed and mixed so as to be 35:65. 25 parts by weight of SiO ₂ was added to 100 parts by weight of the mixed powder as a volatile component, and a dispersant, a binder resin, an antifoaming agent, and water were added and mixed to obtain a slurry having a solid content concentration of 60%. This slurry was centrifugally sprayed and dried to obtain a granulated product having a particle size of 10 to 200 μm. This granulated product was classified to an average particle size of 40 μm and then fired in a nitrogen atmosphere at 1250 ° C. for 6 hours. The obtained fired product was pulverized with a pulverizer, and the particle size was adjusted by sieving to obtain spherical particles having a volume average particle size of about 35 μm. The spherical particles were subjected to surface oxidation treatment at 400 ° C. for 3 hours to prepare [Carrier Core Material 1].

<Preparation of filler particle 1>
100 g of aluminum oxide fine powder having a number average particle size of 0.3 μm was dispersed in 1 L of water to form a suspension, and this suspension was heated to 70 ° C. A solution obtained by dissolving 11.6 g of stannic chloride in 1 L of 2N hydrochloric acid and 12% aqueous ammonia are added dropwise to the heated suspension over 40 minutes so that the pH of the suspension becomes 7-8. did. Subsequently, a solution in which 36.7 g of indium chloride and 5.4 g of stannic chloride are dissolved in 450 mL of 2N hydrochloric acid and 12% aqueous ammonia are added over 1 hour so that the pH of the suspension becomes 7-8. It was dripped. After dropping, the suspension was filtered and washed, and the resulting cake was dried at 110 ° C. Next, this dry powder was treated in a nitrogen stream at 500 ° C. for 1 hour to obtain [Filler particles 1].

<Preparation of carrier 1>
100 parts of a silicone resin solution (SR2411, solid content 20% by weight manufactured by Toray Dow Corning), 40 parts of [Filler particles 1], titanium diisopropoxybis (ethylacetoacetate) (TC-750, manufactured by Matsumoto Fine Chemical Co., Ltd.) as a catalyst 4 parts and 0.20 part of aminosilane (SH6020, manufactured by Toray Dow Corning) were mixed and then diluted with toluene to obtain a resin solution having a solid content of 10%.
On the surface of [Carrier Core 1], the temperature in the fluidized tank is controlled at 70 ° C. using a fluidized bed coating apparatus so that the average thickness of the carrier resin coating layer is 0.30 μm. Applied and dried. Subsequently, it was baked in an electric furnace at 180 ° C. for 2 hours, cooled to room temperature (about 25 ° C.), and then crushed using a sieve having an aperture of 63 μm to obtain [Carrier 1]. The film thickness of the carrier resin coating layer was measured by the following method.

<Measurement of film thickness>
Using a FIB / STEM apparatus (manufactured by Hitachi High-Technologies Corporation, HD-2000), a carrier thin film sample obtained by vapor deposition of molybdenum and carbon is prepared using a focused ion beam (FIB) method, and then a transmission type. Sample observation was performed with an electron microscope. The observation magnification was 50,000 times, and the acceleration voltage was 200 kV. The observation image was taken into an image analysis apparatus (manufactured by Nireco Corporation, Luzex AP) and analyzed, and the average thickness of the coating layer on the carrier surface was calculated.

<Production of developer>
A two-component developer was prepared for the obtained toner as follows. 7 parts by mass of toner with respect to 93 parts by mass of the above [Carrier 1] using a type of tumbler mixer (manufactured by Willy et Bacofen (WAB)) in which the container rolls and stirs for 5 minutes at 67 rpm. Uniform mixing and charging were performed to prepare a two-component developer.

<GPC measurement>
The molecular weight distribution measured by GPC (gel permeation chromatography) of the THF soluble component of the toner was measured as follows.
Gel permeation chromatography (GPC) measuring device: GPC-8220GPC (manufactured by Tosoh Corporation)
Column: TSK-GEL SUPER HZ2000, TSK-GEL SUPER HZ2500, TSK-GEL SUPER HZ3000
Temperature: 40 ° C
Solvent: THF
Flow rate: 0.35 ml / min
Sample: THF sample solution adjusted to 0.15% by mass Sample pretreatment: The toner was dissolved in tetrahydrofuran THF (containing a stabilizer, manufactured by Wako Pure Chemical Industries, Ltd.) at 0.15 wt% and filtered through a 0.45 μm filter. The filtrate was used as a sample.

  The measurement is performed by injecting 10 μL to 200 μL of the THF sample solution. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts.

  As a standard polystyrene sample for preparing a calibration curve, as a standard polystyrene sample for preparing a calibration curve, TSK standard polystyrene manufactured by Tosoh Corporation having a molecular weight of 37200, 6200, 2500, 589, molecular weights 28400, 20298, 10900, 4782, 1689, 1309 Standard polystyrene and toluene manufactured by Showa Denko are used. An RI (refractive index) detector was used as the detector.

  The GPC measurement results are plotted with a molecular weight distribution curve with the vertical axis representing the intensity and the horizontal axis representing the molecular weight, and the point having the maximum peak intensity in the range where the molecular weight is 20000 or less is taken as 100 to correct the intensity of the entire molecular weight distribution curve. It was. The difference between the maximum and minimum intensities was calculated from the maximum value−the minimum value of the intensity in an arbitrary molecular weight M ± 300 range of the obtained molecular weight distribution curve. In addition, the GPC peak intensity difference in the following table | surface shows the maximum value in the value of the said obtained difference.

<External additive release rate>
The liberation rate of the external additive particles was measured as follows.
(1) A 200 mL ointment bottle was added with 100 mL of ion exchange water and 4.4 mL of a 33% by mass dry well aqueous solution (trade name: Drywell, manufactured by Fuji Film Co., Ltd.) containing a surfactant. To the mixed solution, 5 g of toner was added and mixed well by hand shaking 30 times and allowed to stand for 1 hour or longer.
(2) Next, after stirring by hand shaking 20 times, using an ultrasonic homogenizer (trade name: homogenizer, model VCX750, CV33, manufactured by SONICS & MATERIALS), a dial was set at an output of 50%, and it exceeded 2 minutes under the following conditions. Sonic energy was applied and dispersed.
[Ultrasonic conditions]
・ Vibration time: 60 seconds continuous ・ Amplitude: 20 W (30%)
・ Vibration start temperature: 23 ℃ ± 1.5 ℃
(3) The obtained dispersion was suction filtered with a filter paper (trade name: qualitative filter paper (No. 2, 110 mm), manufactured by Advantech Toyo Co., Ltd.), washed again with ion-exchanged water, filtered, and freed. After removing the additive, the toner was dried.
(4) The amount of toner additive before and after removal of the external additive is calculated by mass% from the intensity (or intensity difference before and after removal of the external additive) by the calibration curve using a fluorescent X-ray analyzer (manufactured by Rigaku Corporation, ZSX-100e). The amount of the external additive released was determined by calculation.

From the value of the external additive amount of the toner before and after the dispersion measured by the methods (1) to (4), the liberation rate (% by mass) of the external additive was determined by the following mathematical formula 1.
[Formula 1]
Release rate = [(mass of external additive before dispersion−mass of residual additive after dispersion) / mass of external additive before dispersion] × 100

<Filler exposed area ratio>
For the filler exposed area ratio, first, 50,000 sheets were output (running) in a character image pattern with an image area ratio of 12% using each developer. The carrier exposed area ratio of the carrier was obtained by collecting a small amount of developer from the sleeve of the developing unit after running and blowing the toner to obtain a carrier after running. EDX (energy dispersive X-ray spectroscopy) is used to perform mapping of the corresponding filler element under the following measurement conditions, then to determine the area ratio of the filler with respect to the area of the carrier particles by image processing, and further to the same work to 10 particles or more It was calculated by carrying out against. The acceleration voltage was set to an appropriate voltage depending on the filler type.

[EDX measurement conditions]
・ Sample fixing method Carbon tape (Nisshin EM 8mm × 20m type)
・ Carbon deposition ・ Acceleration voltage: 3-10kV
・ WD 11mm
・ Aperture diameter 30μm
・ Without drift correction ・ Without high current use ・ Time constant 20-30
・ EDX measurement magnification 2000 times ・ Number of integrations 100 times ・ Count mapping or quantitative mapping or simple quantitative mapping count mapping ・ Characteristic X-ray used for mapping (L line or K line) L line

(Evaluation)
The following evaluation was performed about the developer obtained by the said Example and the comparative example.

<Charging stability>
Using each developer, an endurance test for outputting 100,000 sheets continuously was performed using a character image pattern with an image area ratio of 12%, and the change in charge amount at that time was evaluated. A small amount of developer was collected from the sleeve, the change in charge amount was determined by the blow-off method, and evaluated according to the following criteria.
[Evaluation criteria]
A: Change in charge amount is less than 3 μc / g ○: Change in charge amount is 3 μc / g or more and less than 6 μc / g Δ: Change in charge amount is 6 μc / g or more and less than 10 μc / g ×: Change in charge amount is 10 μc / g greater than g

<Toner scattering>
An image forming apparatus (“IPSIO Color 8100”; manufactured by Ricoh Co., Ltd.) was modified to an oil-less fixing method and tuned, and an image area ratio was measured using each developer in an environment of a temperature of 40 ° C. and a humidity of 90%. After conducting a 5% chart continuous 100,000 sheet output durability test, the toner contamination state in the copying machine was visually observed and evaluated based on the following criteria.
[Evaluation criteria]
◎: Toner stains are not observed at all and are in a good state. ○: Slightly stains are not a problem. △: Slight stains are observed. There is a problem

<Photoconductor shaving and photoconductor contamination (photoconductor filming)>
Image formation was performed under the following conditions using an apparatus modified so that the linear velocity of the developing roller in the developing machine of the image forming apparatus (Ricoh MP C305SP, manufactured by Ricoh Co., Ltd.) could be changed. Unless otherwise noted, the agent capacity was 110 g, and the linear velocity of the developing roller in the developing machine was 266 mm / sec.
0% to less than 10,000 sheets at 23 ° C, 50% RH, 10,000 sheets to less than 20,000 sheets at 28 ° C, 85% RH, 20,000 sheets to less than 30,000 sheets at 15 ° C The image area ratio 5% image and the image area ratio 20% image were alternately output every 1,000 sheets under the condition of 30% RH. Up to 90,000 images were created in three sets for this actual machine.
After the completion of the 90,000 image formation, the photoreceptor was observed and the occurrence of an abnormal image in the dot image was confirmed and evaluated according to the following criteria.
Photoreceptor scraping means a state in which the photoconductor is scratched by toner or the like, and if it is severe, the circumferential direction of the photoconductor is shaved.
[Evaluation criteria]
◎: No photoconductor shaving and no photoconductor contamination ○: Photoconductor contamination is slightly observed but not detected in dot image △: Photoconductor shaving has occurred, but a difference is detected in the dot image No: The photoconductor is scratched and a difference is clearly detected in the dot image

<Low temperature fixability>
The image is a cardboard ("copy printing paper <135>"; manufactured by NBS Ricoh Co., Ltd.) using an evaluation machine that was tuned by modifying the image forming apparatus ("IPSIO Color 8100"; manufactured by Ricoh Co., Ltd.) to an oilless fixing system. Was adjusted so that 1.0 ± 0.1 mg / cm ² of toner was developed with a solid image. The fixing roll temperature at which the residual ratio of the image density after rubbing the obtained fixed image with a pad was 70% or more was determined as the minimum fixing temperature.
[Evaluation criteria]
A: The lower limit fixing temperature is less than 110 ° C. The lower limit fixing temperature is 110 ° C. or more and less than 125 Δ: The minimum fixing temperature is 125 ° C. or more and less than 150 ×: The minimum fixing temperature is 150 ° C. or more.

  The obtained evaluation results are shown in Table 1.

  As can be seen from Table 1, the developer using toners 1 to 14 prepared according to the present invention gave good results in charge stability, toner scattering, and photoreceptor filming. Further, the toners 8, 9, 13, and 14 using the crystalline resin also have low-temperature fixability. On the other hand, the toners 15 to 20 have practically problematic levels in charge stability and toner scattering.

10 Electrostatic latent image carrier (photosensitive drum)
10K Black electrostatic latent image carrier 10Y Yellow electrostatic latent image carrier 10M Magenta electrostatic latent image carrier 10C Cyan electrostatic latent image carrier 14 Support roller 15 Support roller 16 Support roller 17 Intermediate transfer 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 roller 28 Sheet reversing 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 Developer container 42Y Developer container 42M Developer container 42C Developer container 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer Supply roller 44K Developing roller 44Y Developing roller 44M Developing row 44C Development roller 45K Black development unit 45Y Yellow development unit 45M Magenta development unit 45C Cyan development unit 49 Registration roller 50 Intermediate transfer belt 51 Roller 52 Separation roller 53 Manual feed path 54 Manual feed tray 55 Switching claw 56 Discharge roller 57 Discharge tray 58 Corona Charging device 60 Cleaning device 61 Developing device 62 Transfer roller 63 Photoconductor cleaning device 64 Static discharge lamp 70 Static discharge lamp 80 Transfer roller 90 Cleaning device 95 Transfer paper 100A, 100B, 100C Image forming device 120 Image forming unit 130 Document base 142 Paper feed roller 143 Paper bank 144 Paper cassette 145 Separation roller 146 Paper feed path 147 Transport roller 148 Paper feed path 150 Copying device main body 160 Charging device 200 Paper feed tray Le 300 Scanner 400 automatic document feeder (ADF)

JP 2010-102167 A Japanese Patent No. 4879145 Japanese Patent No. 4762812 Japanese Patent No. 4984913

Claims (7)

A toner containing at least a binder resin and a release agent and externally added with inorganic fine particles;
A two-component developer comprising at least a core material and a resin coating layer, wherein the resin coating layer includes a carrier containing a filler,
In the molecular weight distribution measured by GPC of the THF soluble component of the toner, when an arbitrary molecular weight M in the range of 300 to 5000 is selected, the peak defined below in the range of ± 300 of the molecular weight M is selected. The difference between the maximum value and the minimum value of the strength is 30 or less, and the external additive liberation rate of the toner is 30% or more and 90% or less,
The two-component developer, wherein the carrier has an exposed area ratio of filler of 20% to 50% of the entire carrier surface after outputting 50,000 sheets.
Peak intensity: Relative value obtained by plotting a molecular weight distribution curve in which the vertical axis is intensity and the horizontal axis is molecular weight by GPC measurement, and the maximum intensity value is 100 in the molecular weight range of 20000 or less.   The two-component developer according to claim 1, wherein the external additive liberation rate of the toner is 40% or more and 80% or less.   3. The two-component developer according to claim 1, wherein the carrier has an exposed area ratio of filler of 25% or more and 40% or less on the entire carrier surface after outputting 50,000 sheets.   The two-component developer according to claim 1, wherein the binder resin contains a crystalline resin, and the melting point of the crystalline resin is in the range of 50 ° C. or more and 65 ° C. or less. .   The toner includes an oil phase composition including a binder resin precursor made of at least a modified polyester resin, and the oil phase composition is emulsified and dispersed in an aqueous medium to which a fine particle dispersant is added. The two-component developer according to any one of claims 1 to 4, wherein the two-component developer is prepared by a step of forming a liquid and a step of removing an organic solvent from the emulsion dispersion.   A developer containing unit containing the two-component developer according to claim 1. An electrostatic latent image carrier;
Electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier;
Using the two-component developer according to claim 1, developing means for developing the electrostatic latent image to form a visible image;
Transfer means for transferring the visible image onto a recording medium;
An image forming apparatus comprising: fixing means for fixing the transferred image transferred onto the recording medium.

Images