JP2010271606A - Toner, two-component developer, process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner, a two-component developer, a process cartridge and an image forming apparatus achieving low temperature fixability, heat-resistant storage properties, development stability and responsiveness to high-speed printing. <P>SOLUTION: The toner has a core-shell structure comprising a core and a shell layer having a thickness of 0.01 μm to 2 μm formed on the surface of the core. The core contains at least a binder resin and a colorant, while the shell layer contains at least a crystalline polyester resin as a binder resin. The softening temperature ST of the shell layer and the softening temperature CT of the inner core measured by use of a SPM probe having a built-in heater satisfy the relational expression (1):1.1≤CT/ST≤2.5. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a toner, a two-component developer, a process cartridge, and an image forming apparatus that are used for electrophotographic image formation.

In an electrophotographic apparatus or an electrostatic recording apparatus, a toner is attached to an electrostatic latent image formed on a photosensitive member, transferred to a transfer material, and then fixed to a transfer material such as paper by heat. An image is formed. Also, full-color image formation is generally performed by using four color toners of black, yellow, magenta, and cyan. Each color is developed, and each toner layer is superimposed on a transfer material. To obtain a full-color image.
However, for users who are familiar with printing and silver halide photography, the images on full-color copiers are still not satisfactory, and there is a need for higher image quality that satisfies photography, high-definition, and high resolution. Yes. Especially when using thick paper or when printing at high speed, the heat quantity at the time of fixing is not sufficiently transmitted, and the image has excellent fixing properties and high image quality (small variations in gloss, density, image sharpness, etc.). Was difficult.
In addition, the toner in such a low-temperature fixing system can be manufactured as a toner that supports low-temperature fixing by lowering the softening property of the toner. Absent. High-temperature and high-humidity and low-temperature and low-humidity environments during storage and transportation after toner production are severe conditions for the toner, and the toner does not aggregate even after storage in the environment, and charging characteristics, fluidity, transferability, and fixability Therefore, there is a demand for a toner that does not deteriorate or has an extremely low storage stability. On the other hand, it has been found that the toner spent on the developing member, carrier, etc. adversely affects the charging and developing characteristics, and an image forming apparatus that achieves both low-temperature fixing properties, heat-resistant storage properties, and development stability. There was a problem that it was difficult to obtain.

In order to improve this problem, Patent Document 1 discloses a core-shell type toner containing at least a colorant, a binder resin, and a filler, and the toner has a flow tester 1/2 outflow temperature of 60 ° C. or higher and 100 ° C. An electrostatic charge image developing toner in which the shell contains a thermoplastic resin is disclosed below.
According to Patent Document 2, a vinyl polymer resin (= island resin) formed from a vinyl polymerizable monomer containing a polyvalent carboxylic acid is dispersed in a vinyl copolymer sea resin. It has a sea-island structure, where TgA is the glass transition point of the sea resin, TgB is the glass transition point of the island resin, and TgC is the glass transition point of the shell resin. These glass transition points are TgB <TgA <TgC. An electrostatic charge image developing toner having the following relationship is disclosed.
In Patent Document 3, a toner for electrostatic charge development having a core-shell structure having a core layer composed of toner base particles containing a binder resin and a colorant, and a shell layer covering the core layer, the shell layer Contains an amorphous polymer obtained by polymerizing an alicyclic monomer having 11 to 14 carbon atoms, or a toner containing a binder resin and a colorant An electrostatic charge developing toner having a core-shell structure having a core layer made of mother particles and a shell layer covering the core layer, wherein the shell layer is an electrostatic charge image developing toner containing an acrylic silicone resin. It is disclosed.

However, even with these disclosed techniques, it has been difficult to obtain a toner that is fixed at low temperature and has both heat-resistant storage characteristics.
Accordingly, the present invention has been made in view of the above-mentioned problems, and its problems are a toner, a two-component developer, a process cartridge, and a toner that ensure low-temperature fixability, heat-resistant storage stability, development stability, and high-speed printing compatibility. An image forming apparatus is provided.

The features of the present invention, which is a means for solving the above problems, are listed below.
Thus, according to the present invention, the following (1) to (14) are provided.
1. The toner of the present invention is a core-shell structure toner having a core and a shell layer having a thickness of 0.01 μm to 2 μm on the surface of the core, and the core contains at least a binder resin, a colorant and the like. The shell layer contains at least a crystalline polyester resin as a binder resin, and the softening temperature ST of the shell layer and the softening temperature CT of the inner core measured by an SPM probe with a built-in heater are 1.1. <= CT / ST <= 2.5 ... It has the relational expression (1) by Formula (1), It is characterized by the above-mentioned.
2. The toner of the present invention is further characterized by having a shell layer coated in layers after covering the toner surface with resin fine particles containing at least crystalline polyester.
3. The toner of the present invention is further characterized in that the binder resin of the toner core contains at least a polyester resin.
4). The toner of the present invention further includes at least a modified polyester resin.
5). Further, the toner of the present invention is further characterized in that an organic solvent oil droplet in which a toner composition containing a prepolymer is dissolved is dispersed in an aqueous medium, and is formed by an extension reaction and / or a crosslinking reaction. .
6). The toner of the present invention further comprises a toner composition containing at least a polymer capable of reacting with a compound having an active hydrogen group, a polyester, a colorant, and a release agent in the presence of resin fine particles in an aqueous medium. Under the crosslinking and / or elongation reaction, it is characterized by the following.
7). The toner of the present invention is further characterized in that the average circularity E of the toner is from 0.93 to 0.99.
8). The toner of the present invention is further characterized in that the toner has a circularity SF-1 value of 100 to 150 and a circularity SF-2 value of 100 to 140.
9. The toner of the present invention further has a weight average particle diameter D4 of 2 to 7 μm and a ratio D4 / Dn of the weight average particle diameter D4 to the number average particle diameter Dn of 1.25 or less. Features.

10. The two-component developer of the present invention has a magnetic carrier and toner, and in the two-component developer used in the image forming apparatus, the toner is the toner according to claim 1. It is characterized by.
11. The process cartridge of the present invention is a process cartridge which integrally supports an image carrier and at least a developing device and is detachable from an image forming apparatus main body, wherein the developing device uses the toner according to any one of claims 1 to 9. It is characterized by using.
12 . The image forming apparatus of the present invention is an image forming apparatus including a fixing device having a fixing medium that fixes a visible image formed with toner on a recording medium by heat and pressure. The image forming apparatus includes at least four or more image forming apparatuses. in tandem developing system of arranging the different developing device color in series, and the system speed is 500~2500mm / sec, pressing surface pressure of the fixing ^medium, that is 5N / cm ² ~90N / cm 2 Features.

  According to the present invention which is a means for solving the above problems, it is possible to provide a toner, a developer, a process cartridge, and an image forming apparatus that ensure low-temperature fixability, heat-resistant storage stability, development stability and high-speed printing compatibility.

It is a figure for demonstrating the outline | summary of the measurement of the softening temperature of the shell layer and core by nano-TA. 1 is a schematic diagram illustrating a configuration of an image forming apparatus including a process cartridge according to the present invention. 1 is a schematic diagram illustrating a configuration of a main part of a direct transfer type tandem color image forming apparatus. 1 is a schematic diagram illustrating a configuration of a main part of a tandem color image forming apparatus having an indirect transfer type intermediate transfer belt. 1 illustrates an embodiment of the present invention and is a tandem indirect transfer type image forming apparatus. 1 is a diagram illustrating a configuration of a fixing device used in an image forming apparatus of the present invention.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Note that it is easy for a person skilled in the art to make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.

The toner of the present invention is a core-shell toner having a core and a shell layer having a thickness of 0.01 μm to 2 μm on the surface of the core. A toner having a stable and uniform core-shell structure and a structure in which the softening temperature is different between the shell layer and the core can be stably provided, which is more preferable. In particular, the toner has a core-shell structure having a shell layer of 0.01 μm to 2 μm, more preferably 0.4 μm to 1.5 μm outside the toner. By using this toner, it is possible to obtain a toner that ensures low-temperature fixability, heat-resistant storage stability, development stability, and high-speed printing compatibility. In particular, the toner core contains a binder resin that is advantageous for achieving both low-temperature fixability and heat-resistant storage stability, and the toner shell layer ensures low-temperature fixability and heat-resistant storage stability. Further, the shell layer protects against wax, pigment, and poorly charged components that adversely affect the charging characteristics inside the toner, the carrier, and spent on the developing member. If the thickness of the shell layer is less than 0.01 μm, the effect as a layer is not sufficient, which is not preferable. On the other hand, if the thickness exceeds 2 μm, the shell layer is too thick, and the color developability by the colorant inside the core and the oozing property of the wax deteriorate, which is not preferable. Further, it is not preferable because the low-temperature fixability of the shell layer cannot be sufficiently secured.
In the toner of the present invention, the shell layer is preferably formed in a layered state after covering the toner surface with resin fine particles. Thereby, a strong and stable shell layer can be formed.

Such a toner can be manufactured using a wet granulation method in an aqueous medium. When the toner is produced by a wet granulation method in an aqueous medium, the crystalline polyester resin as a highly polar resin segregates on the surface of the toner, thereby suppressing the exposure of the colorant and the release agent to the surface. Since this crystalline polyester resin easily moves to the O / W interface due to its high polarity, a shell layer is formed around the binder resin containing the core colorant and release agent.
As described above, the toner of the present invention is characterized in that a resin layer containing at least crystalline polyester is used to cover the surface of the toner, and then a shell layer is formed in a layered state. By containing at least a crystalline polyester resin as a binder resin in the shell layer, a toner that achieves sharp melting with respect to the heating temperature while maintaining sufficient heat-resistant storage stability on the toner surface is more preferable. In general, when the softening temperature of the shell layer is lowered in the core-shell structure, a problem occurs in the heat-resistant storage stability, but sufficient heat-resistant storage stability can be imparted by utilizing the sharp melting characteristics of the crystalline polyester.
This crystalline polyester will be described later.

Further, in the toner of the present invention, the relationship between the softening temperature ST of the shell layer and the softening temperature CT of the inner core measured by an SPM probe with a built-in heater satisfies 1.1 ≦ CT / ST ≦ 2.5. The expression (1) is satisfied.
When heat is applied to the toner, heat is first transferred to the shell layer side to start melting of the shell layer having a low softening temperature, and the melting of the inner core is accelerated by the plastic effect of the crystalline polyester of the shell layer. As a toner melted at a lower temperature, sharp melt characteristics can be achieved. Here, when CT / ST (hereinafter referred to as “softening temperature ratio”) is less than 1.1, the shell layer has a high softening temperature and cannot function as a low-temperature fixing. Furthermore, when the softening temperature ratio exceeds 2.5, the softening temperature of the shell layer is too low, which causes carrier spent and the like, which is not preferable from the viewpoint of development stability. Also, the softening temperature of the core layer is too high, and low temperature fixability cannot be achieved.

The toner of the present invention is further characterized in that the core contains at least a polyester resin. By using a polyester resin capable of sharpening, the softening temperature ST of the shell layer and the softening temperature CT of the inner core satisfy the relational expression (1), and the thermal properties and viscoelastic properties of the resin The design range is broader and more preferable.
Further, the toner of the present invention is a toner comprising particles formed by extending an organic solvent oil droplet in which a prepolymer-containing toner composition is dissolved in an aqueous medium and then performing an elongation reaction and / or a crosslinking reaction. It is characterized by that. As described above, the oil phase containing the toner composition containing the prepolymer that becomes the core portion of the toner and the aqueous phase containing the resin raw material and the toner raw material that becomes the shell layer are mixed and emulsified, and the oil phase component Oil droplets are formed in an aqueous medium to undergo an extension reaction and / or a crosslinking reaction, resin fine particles adhere to the periphery, and a shell layer is formed around the periphery to form toner droplets.
The toner of the present invention further comprises a toner composition containing at least a polymer capable of reacting with a compound having an active hydrogen group, a polyester, a colorant, and a release agent in the presence of resin fine particles in an aqueous medium. It is a toner that undergoes crosslinking and / or elongation reaction underneath. As a result, a core-shell structure can be formed by these, and a polyester resin can be contained in both the core and the shell. Therefore, it is more preferable that a toner having appropriate softening characteristics can be formed by the shell layer and the core.

  In addition, the toner of the present invention is further characterized in that it is a toner having an average circularity E of 0.93 to 0.99. A core-shell structure can be secured with a shape close to a sphere appropriately, which is more preferable. The toner of the present invention is further characterized in that the value of circularity SF-1 is 100 to 150 and the value of circularity SF-2 is 100 to 140. A core-shell structure can be secured with a shape close to a sphere appropriately, which is more preferable. It is more preferable that toner particles having a uniform core-shell structure can be formed while securing the charge developing property, transfer property and fixing property of the toner. Further, the toner of the present invention has a weight average particle diameter D4 of 2 to 7 μm, more preferably 2 to 5 μm, and a ratio D4 / Dn of the weight average particle diameter D4 to the number average particle diameter Dn of 1.25 is more preferable. Is 1.15 or less. It is more preferable that toner particles having a uniform core-shell structure can be formed while securing the charge developing property, transfer property and fixing property of the toner.

Hereinafter, a method for evaluating the characteristics of the toner of the present invention will be described in detail.
(Evaluation of crystallinity)
The presence or absence of crystallinity in the present invention was evaluated by the presence or absence of a crystalline peak by X-ray diffraction.
The equipment and conditions are shown below.
XRD: manufactured by Rigaku Corporation RIN / T-TTRIII type wide angle X-ray diffractometer X-ray source; CuKα ray tube voltage-tube current; 50 kV-300 mA
Step width: 0.02 deg
Measurement range: 2 ° -60 °
Measurement speed: 5 deg./min.
Slit system; 0.5 deg. -0.15 mm-0.5 deg.
Diffraction line crystal monochromator

(Evaluation of toner shell layer thickness)
The thickness of the shell layer of the toner in the present invention is preferably evaluated by the following method, but any other means may be used if it can be evaluated by other means. The thickness of the shell layer was randomly measured at 10 particles and evaluated by the average value.
1) Evaluation by TEM (Transmission Electron Microscope) The toner is embedded in an epoxy resin about a full spatula and cured. The shell layer and the inside of the core are differentially stained by exposing the sample to gas with ruthenium tetroxide for 5 minutes. The cross section is cut out with a knife, and an ultrathin section (200 nm thickness) of toner is prepared with an ultramicrotome (ULTRACUT UCT manufactured by Leica, using a diamond knife). Thereafter, observation is performed with a TEM (transmission electron microscope; H7000; manufactured by Hitachi High-Tech) at an acceleration voltage of 10 kV.
2) Evaluation by FE-SEM (Scanning Electron Microscope) The toner is embedded in an epoxy resin about one full spatula and cured. The shell layer and the inside of the core are differentially stained by exposing the sample to gas with ruthenium tetroxide for 5 minutes. Create a cross-section with a knife and create a cross-section of the toner with an ultramicrotome (Leica ULTRACUT UCT, using diamond knife). Thereafter, a reflected electron image is observed with an FE-SEM (scanning electron microscope; Ultra 55; manufactured by Zeiss) at an acceleration voltage of 0.8 kV.
3) Evaluation by SPM The toner is embedded in an epoxy resin about one full of a spatula and cured. Create a cross-section with a knife and create a cross-section of the toner with an ultramicrotome (Leica ULTRACUT UCT, using diamond knife). Thereafter, a layer image due to a difference in viscoelasticity and adhesion is observed with a phase image in a tapping mode with an SPM (scanning probe microscope; MMAFM type multi-mode SPM unit; manufactured by Veeco).

(Evaluation of softening temperature of shell layer and core)
The softening temperature evaluation of the shell layer and the core by nano-TA of the present invention is preferably performed by the following method, but may be performed as long as it can be evaluated by other means.
The nano-TA unit was evaluated by installing a TMA (thermomechanical analysis) unit manufactured by Nano Thermal Analysis System in SPM. The SPM used was a scanning probe microscope manufactured by Veeco; MMMAM type multimode SPM unit.
FIG. 1 is a diagram for explaining an outline of measurement of the softening temperature of the shell layer and the core by nano-TA.
nano-TA is a technique for evaluating the softening characteristics (TMA) and thermal characteristics of a sample using an SPM probe with a built-in heater.
As shown in (1), the probe (hereinafter referred to as “cantilever”) is moved to the measurement position of the sample, and the tip of the cantilever is heated. The sample then undergoes a slight thermal expansion, resulting in a cantilever deflection. As shown in (2), as the temperature rises, the deviation increases monotonously. Next, as shown in (3), the shell layer or the core is softened and the cantilever sinks due to the temperature rise. By evaluating the deflection position of this cantilever, the sinking with respect to temperature is evaluated. Here, the deflection inflection point is evaluated as the softening temperature. As shown in FIG. 1, the nano-TA system can evaluate the softening characteristic (TMA characteristic) of a target place with a resolution of 20 nm using a sensitive dedicated cantilever equivalent to an atomic force microscope. Measurement positioning can be performed in contact mode or tapping mode as a normal atomic force microscope, and the shell layer of the target toner cross section and the softening characteristics inside the core can be individually evaluated. In consideration of measurement variation, it is preferable to evaluate the average softening temperature of five toner particles. The heating rate of the cantilever was 5 ° C./sec. The softening temperature of the apparatus is calibrated using three standard resins whose softening temperatures are known in advance.

(Average circularity E)
The average circularity E of the toner is defined by the circularity E = (peripheral length of a circle having the same area as the particle projection area / perimeter length of the particle projection image) × 100%. Measurement was performed using a flow type particle image analyzer (FPIA-2100; manufactured by Sysmex Corporation), and analysis was performed using analysis software (FPIA-2100 Data Processing for Program for FPIA version 00-10). Specifically, 0.1 to 0.5 mL of 10 wt% surfactant (alkylbenzene sulfonate Neogen SC-A; Daiichi Kogyo Seiyaku) is added to a glass 100 mL beaker, and each toner 0.1 to 0 is added. 0.5 g was added and stirred with a microspatel, and then 80 mL of ion-exchanged water was added. The obtained dispersion was 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 were measured using the FPIA-2100 until the concentration of 5000 to 15000 / μL was obtained. In this measurement method, it is important that the concentration of the dispersion is 5000 to 15000 / μL from the viewpoint of measurement reproducibility of the average circularity. In order to obtain the dispersion concentration, it is necessary to change the conditions of the dispersion, that is, the amount of surfactant to be added and the amount of toner. Similar to the measurement of the toner particle size described above, the required amount of the surfactant varies depending on the hydrophobicity of the toner. If it is added in a large amount, noise due to bubbles is generated. It will be enough. Further, the toner addition amount differs from 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 0.5 g, the dispersion concentration can be adjusted to 5000 to 15000 / μL.

(Circularity SF-1, SF-2)
The shape factors SF-1 and SF-2, which are the circularity applied to the present invention, are 300 random FE-SEM images of toner obtained by measurement with Hitachi FE-SEM (S-4200). The image information was introduced into an image analyzer (Luzex AP) manufactured by Nireco through an interface and analyzed, and the values obtained from the following equations were defined as SF-1 and SF-2. The values of SF-1 and SF-2 are preferably values obtained by Luzex, but are not particularly limited to the FE-SEM device and the image analysis device as long as similar analysis results can be obtained.
SF-1 = (L ² / A) × (π / 4) × 100
SF-2 = (P ² / A) × (1 / 4π) × 100
Here, the absolute maximum length of the toner is L, the projected area of the toner is A, and the maximum peripheral length of the toner is P.
In the case of a true sphere, all become 100, and from a spherical shape to an indefinite shape as the value becomes larger than 100. In particular, SF-1 represents the shape of the entire toner (ellipse, sphere, etc.), and SF-2 is a shape factor indicating the degree of surface irregularities.

(Weight average particle diameter, D4 / Dn (ratio of weight average particle diameter / number average particle diameter))
The weight average particle diameter (D4), number average particle diameter (Dn), and ratio (D4 / Dn) of the toner can be measured by the following method. The average particle size and particle size distribution of the toner can be measured using a Coulter Counter TA-II, Coulter Multisizer II (both manufactured by Coulter, Inc.) and the like. In particular, Coulter Multisizer II is used in the present invention. The measurement method is described below.
First, 0.1 to 5 mL of a surfactant (preferably polyoxyethylene alkyl ether (nonionic surfactant)) is added as a dispersant to 100 to 150 mL of the electrolytic aqueous solution. Here, the electrolytic solution is a solution prepared by preparing a 1% NaCl aqueous solution using first grade sodium chloride. For example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the measurement device is used to measure the volume and number of toner particles or toner using a 100 μm aperture as an aperture. Volume distribution and number distribution are calculated. From the obtained distribution, the weight average particle diameter (D4) and the number average particle diameter of the toner can be obtained.
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 .35 to less than 8.00 μm; 8.00 to less than 10.08 μm; 10.08 to less than 12.70 μm; 12.70 to less than 16.00 μm; 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm.

(System speed)
In the present invention, the system linear velocity was measured as follows. When A4 paper, longitudinal paper passage (length of paper passing paper is 297 mm), continuous 100 sheets, output by the corresponding image forming apparatus, the output time from the start to the end is A second, and the system speed is B, The system speed was calculated by the following formula.
B (mm / sec) = 100 sheets × 297 (mm) ÷ A (sec)

(Fixing pressure surface pressure)
The fixing pressure surface pressure in the present invention can be evaluated by using a general pressure sensor. Further, the pressure can be measured by passing the paper whose color changes depending on the pressure through the fixing device. Either method may be used.

(Process cartridge)
FIG. 2 is a schematic diagram showing a configuration of an image forming apparatus including the process cartridge of the present invention. In FIG. 2, the entire process cartridge 2 is shown, and includes a photoreceptor 3, a charging device 10, a developing device 40, and a cleaning device 20.
In the present invention, among the constituent elements such as the photosensitive member 3, the charging device 10, the developing device 40, and the cleaning device 20, at least the photosensitive member 3 and the developing device 40 are integrally coupled as the process cartridge 2, and this process is performed. The cartridge 2 is configured to be detachable from the main body of the image forming apparatus 1 such as a copying machine or a printer.

(Molecular weight distribution; Mn, Mw)
The number average molecular weight Mn and the weight average molecular weight Mw of the toner can be measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC was performed with a THF solvent using a Tosoh GPC HLC-8120 as a measuring device and a Tosoh column TSKgel SuperHM-M (15 cm). Each average molecular weight is calculated from the measurement result using a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample.

(Glass transition point; Tg)
The glass transition point (Tg) was measured using a TG-DSC system TAS-100 manufactured by Rigaku Corporation.
About 10 mg of a sample is put in an aluminum sample container, which is placed on a holder unit and set in an electric furnace. Next, after heating from room temperature to 150 ° C. at a heating rate of 10 ° C./min, the sample is allowed to stand at 150 ° C. for 10 minutes, and then the sample is cooled to room temperature and left for 10 minutes. Further, the DSC measurement is performed by heating again to 150 ° C. at a heating rate of 10 ° C./min under a nitrogen atmosphere. Tg is calculated from the contact point between the tangent line and the base line of the endothermic curve near Tg, using the analysis system in the TAS-100 system.

(Resin fine particles containing at least crystalline polyester)
The toner preferably uses fine resin particles containing at least crystalline polyester. The resin fine particles used must have a glass transition point (Tg) in the range of 40 to 100 ° C, more preferably in the range of 55 to 90 ° C, and in the range of 60 to 85 ° C. Is more desirable. The weight average molecular weight is more preferably 2,000 to 300,000. As described above, when the glass transition point (Tg) is less than 40 ° C. and / or the weight average molecular weight is less than 2,000, the storage stability of the toner is deteriorated and stored. In addition, blocking occurs in the developing machine. When the glass transition point (Tg) exceeds 100 ° C. and / or the weight average molecular weight exceeds 300,000, the resin fine particles inhibit the adhesion to the fixing paper, and the fixing minimum temperature becomes high.
In the present invention, “crystalline polyester resin” means a polymer (copolymer) obtained by polymerizing a component constituting a polyester and another component in addition to a polymer having a 100% polyester structure as a constituent component. To do. However, in the latter case, the component other than the polyester constituting the polymer (copolymer) is 50% by mass or less.

The crystalline polyester resin used in the toner of the present invention is synthesized from, for example, a polyvalent carboxylic acid component and a polyhydric alcohol component. In this embodiment, a commercially available product may be used as the crystalline polyester resin, or a synthesized product may be used.
Examples of the polyvalent carboxylic acid component include oxalic acid, succinic acid, glutaric acid, adipic acid, peric acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12 -Aliphatic dicarboxylic acids such as dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid; phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, mesaconic acid Aromatic dicarboxylic acids such as dibasic acids such as, and the like, and anhydrides and lower alkyl esters thereof are also included, but not limited thereto.
Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like, and anhydrides thereof. And lower alkyl esters. These may be used individually by 1 type and may use 2 or more types together.

Moreover, as an acid component, the dicarboxylic acid component which has a sulfonic acid group other than the said aliphatic dicarboxylic acid and aromatic dicarboxylic acid may be contained. Furthermore, in addition to the aliphatic dicarboxylic acid and aromatic dicarboxylic acid, a dicarboxylic acid component having a double bond may be contained.
As the polyhydric alcohol component, an aliphatic diol is preferable, and a linear aliphatic diol having 7 to 20 carbon atoms in the main chain portion is more preferable. If the aliphatic diol is branched, the crystallinity of the polyester resin is lowered, and the melting point may be lowered. Further, when the main chain portion has less than 7 carbon atoms, when polycondensation with an aromatic dicarboxylic acid, the melting temperature becomes high and fixing at low temperature may be difficult, while the main chain portion has 20 carbon atoms. Exceeding the above range makes it difficult to obtain practical materials. The number of carbon atoms in the main chain portion is more preferably 14 or less.

Specific examples of the aliphatic diol suitably used for the synthesis of the crystalline polyester used in the toner of the present invention include ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,5. -Pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12- Examples include dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,14-eicosandecanediol, and the like, but are not limited thereto. Among these, considering availability, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are desirable.
Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like. These may be used individually by 1 type and may use 2 or more types together.
Among the polyhydric alcohol components, the content of the aliphatic diol is preferably 80 mol% or more, and more preferably 90% or more. If the content of the aliphatic diol is less than 80 mol%, the crystallinity of the polyester resin is lowered and the melting temperature is lowered, so that toner blocking resistance, image storage stability, and low-temperature fixability may be deteriorated. .

If necessary, a polycarboxylic acid or a polyhydric alcohol may be added at the final stage of the synthesis for the purpose of adjusting the acid value or the hydroxyl value. Examples of polycarboxylic acids include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalenedicarboxylic acid; maleic anhydride, fumaric acid, succinic acid, alkenyl Aliphatic carboxylic acids such as succinic anhydride and adipic acid; and alicyclic carboxylic acids such as cyclohexanedicarboxylic acid.
Examples of polyhydric alcohols include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin; cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, etc. And aromatic diols such as bisphenol A ethylene oxide adduct and bisphenol A propylene oxide adduct.

The crystalline polyester resin can be produced at a polymerization temperature of 180 to 230 ° C., and the reaction system is depressurized as necessary, and the reaction is carried out while removing water and alcohol generated during the condensation.
When the polymerizable monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution auxiliary solvent is distilled off. If there is a polymerizable monomer having poor compatibility in the copolymerization reaction, the polymerizable monomer having poor compatibility and the polymerizable monomer and the acid or alcohol to be polycondensed are condensed in advance. And then polycondensation with the main component.

Catalysts usable in the production of the polyester resin include alkali metal compounds such as sodium and lithium; alkaline earth metal compounds such as magnesium and calcium; zinc, manganese, antimony, titanium, tin, zirconium, germanium and the like Metal compounds; phosphorous acid compounds; phosphoric acid compounds; and amine compounds.
Specifically, sodium acetate, sodium carbonate, lithium acetate, lithium carbonate, calcium acetate, calcium stearate, magnesium acetate, zinc acetate, zinc stearate, zinc naphthenate, zinc chloride, manganese acetate, manganese naphthenate, titanium tetraethoxy , Titanium tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, antimony trioxide, triphenylantimony, tributylantimony, tin formate, tin oxalate, tetraphenyltin, dibutyltin dichloride, dibutyltin oxide, diphenyltin oxide, zirconium tetra Butoxide, zirconium naphthenate, zirconyl carbonate, zirconyl acetate, zirconyl stearate, zirconyl octylate, germanium oxide, trif Alkenyl phosphite, tris (2,4-di -t- butyl-phenyl) phosphite, ethyltriphenylphosphonium bromide, triethylamine, compounds such as triphenyl amine.

The acid value of the crystalline polyester resin used in the present invention (mg number of KOH required to neutralize 1 g of resin) is desirably in the range of 3.0 to 30.0 mgKOH / g, and 6.0 to 25 More desirably, it is in the range of 0.0 mgKOH / g, and more desirably in the range of 8.0 to 20.0 mgKOH / g.
When the acid value is less than 3.0 mgKOH / g, the dispersibility in water is lowered, and thus it may be very difficult to produce particles by a wet manufacturing method. In addition, since stability as polymerized particles during aggregation is significantly reduced, it may be difficult to produce an efficient toner. On the other hand, when the acid value exceeds 30.0 mgKOH / g, the hygroscopicity as a toner increases and it may be easily affected by the environment as a toner.

  The crystalline resin containing the above crystalline polyester resin is preferably composed mainly of a crystalline polyester resin synthesized using an aliphatic polymerizable monomer (50% by mass or more). Furthermore, in this case, the composition ratio of the aliphatic polymerizable monomer constituting the crystalline polyester resin synthesized using the aliphatic polymerizable monomer is desirably 60 mol% or more, and 90 mol% or more. It is more desirable. As the aliphatic polymerizable monomer, the above-mentioned aliphatic diols and dicarboxylic acids can be suitably used.

The following emulsification step is preferably used as a method for producing resin fine particles containing at least a crystalline polyester resin of the present invention. In particular, when a toner shell layer is formed, it is more preferably used in the state of an emulsified dispersion.
-Emulsification process-
In the emulsification step of the present invention, one or more types of crystalline resins and, if necessary, one or more types of non-crystalline polyester resins are used for the organic solvent used at a temperature higher than the melting point of the resin or the glass transition temperature. After heating and dissolving to a temperature below the boiling point to make a uniform solution, a basic aqueous solution is added as a neutralizing agent, and then the phase is changed by adding stirring water while maintaining pure pH 7-9 while adding pure water. An O / W emulsion (emulsion) of resin is obtained. Next, the obtained emulsion is distilled under reduced pressure to remove the solvent and obtain a resin particle emulsion.
The pH after neutralization is 7 to 9, preferably 7 to 8. As the basic aqueous solution, for example, an alkali metal hydroxide such as an aqueous ammonium solution, sodium hydroxide, or potassium hydroxide may be used. When the pH is less than 7, there is a problem that coarse particles are likely to be generated in the emulsion, and when the pH is more than 9, there is a problem that the agglomerated particle size is expanded due to aggregation in the next step.
By using particles in which the crystalline polyester resin and the non-crystalline polyester resin are compatible as described above, the release agent particles have a lower acid value, and the resin particle portions are likely to agglomerate. A toner having the structure can be obtained.

<Emulsified dispersion>
The average particle size of the resin particles is usually 1000 nm or less, preferably 10 nm to 1000 nm. More preferably, it is 10 nm-800 nm, More preferably, it is 100-500 nm. The particle size was evaluated using a laser diffraction / scattering particle size distribution measuring device (LA-920, manufactured by Horiba, Ltd.).
When the average particle size of the resin particles exceeds 1000 nm, the particle size distribution of the finally obtained toner cannot be stably controlled, and free particles are generated, resulting in a decrease in performance and reliability. If the thickness is less than 10 nm, toner particles cannot be formed, which is not preferable.
Examples of the dispersion medium in the dispersion include an aqueous medium and an organic solvent. Examples of the aqueous medium include water such as distilled water and ion-exchanged water, alcohols, acetate esters, ketones, and mixtures thereof. These may be used singly or in combination of two or more.
In the present invention, a surfactant may be added to and mixed with the aqueous medium. Although it does not specifically limit as surfactant, For example, anionic surfactants, such as sulfate ester type, sulfonate type, phosphate ester type, soap type; amine salt type, quaternary ammonium salt type, etc. Nonionic surfactants such as polyethylene glycol-based, alkylphenol ethylene oxide adduct-based, polyhydric alcohol-based, and the like. Among these, anionic surfactants and cationic surfactants are preferable. The nonionic surfactant is preferably used in combination with the anionic surfactant or the cationic surfactant. Surfactant may be used individually by 1 type and may use 2 or more types together.

Specific examples of the anionic surfactant include sodium dodecylbenzenesulfonate, sodium dodecylsulfate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate and the like. Specific examples of the cationic surfactant include alkylbenzene dimethyl ammonium chloride, alkyl trimethyl ammonium chloride, distearyl ammonium chloride and the like. Among these, ionic surfactants such as anionic surfactants and cationic surfactants are preferable.
As the organic solvent, for example, an alcohol such as ethyl acetate, methyl ethyl ketone, acetone, toluene and isopropyl alcohol can be used, and the organic solvent is appropriately selected according to the binder resin.
When the resin particle is a crystalline polyester or an amorphous polyester resin, it has a self-water dispersibility containing a functional group that can be anionic by neutralization, and a part or all of the functional group that can be hydrophilic is a base. A neutralized, stable aqueous dispersion can be formed under the action of an aqueous medium. In the crystalline polyester and the non-crystalline polyester resin, the functional group that can become a hydrophilic group by neutralization is an acidic group such as a carboxyl group or a sulfone group, and examples of the neutralizing agent include sodium hydroxide, potassium hydroxide, Examples thereof include inorganic bases such as lithium hydroxide, calcium hydroxide, sodium carbonate and ammonia, and organic bases such as diethylamine, triethylamine and isopropylamine.

  When a polyester resin that does not disperse in water, that is, does not have self-water dispersibility, is used as a binder resin, the resin solution and / or an aqueous medium mixed with the resin solution as described later will be ionic. Disperse with polymer electrolytes such as surfactants, polymer acids, polymer bases, etc., heat above melting point, and process with a homogenizer or pressure discharge type disperser that can apply a strong shearing force. Of particles. When this ionic surfactant or polymer electrolyte is used, the concentration in the aqueous medium may be about 0.5 to 5% by weight.

(Polyester resin)
In the present invention, the following polyester resin is preferably used as the binder resin for the toner. In particular, it is preferable to use a polyester resin as a binder resin for the core.
Examples of the polyester resin include a modified polyester resin and an unmodified polyester resin, and it is more preferable to contain both.
(Modified polyester resin)
In the present invention, the following modified polyester resins can be used as the polyester resin. For example, a polyester prepolymer having an isocyanate group can be used. Examples of the polyester prepolymer (A) having an isocyanate group include a product obtained by further reacting a polyester having an active hydrogen group with a polyisocyanate (3), which is a polycondensate of polyol (1) and polycarboxylic acid (2). Can be mentioned. Examples of the active hydrogen group possessed by the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like. Among these, alcoholic hydroxyl groups are preferred.
Examples of the polyol (1) include a diol (1-1) and a tri- or higher valent polyol (1-2). (1-1) alone or (1-1) and a small amount of (1-2) Mixtures are preferred. Diol (1-1) includes alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) ), Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide Nord acids (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyol (1-2) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polycarboxylic acid include dicarboxylic acid and trivalent or higher polycarboxylic acid, and dicarboxylic acid alone or a mixture of dicarboxylic acid and a small amount of polycarboxylic acid is preferable. Dicarboxylic acids include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, etc.) ) And the like. Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher valent polycarboxylic acid include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polycarboxylic acid, you may make it react with a polyol using the acid anhydride or lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) of the above-mentioned thing.

The ratio between the polyol and the polycarboxylic acid is usually 2/1 to 1/1, preferably 1.5 / 1 to 1/1 / as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. 1, more preferably 1.3 / 1 to 1.02 / 1.
Polyisocyanates include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic diisocyanates ( Tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; the polyisocyanates blocked with phenol derivatives, oximes, caprolactam, etc. And combinations of two or more of these.
The ratio of the polyisocyanate is usually 5/1 to 1/1, preferably 4/1 to 1 as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. .2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. If the molar ratio of [NCO] is less than 1, the urea content in the modified polyester will be low, and the hot offset resistance will deteriorate. The content of the polyisocyanate component in the prepolymer having an isocyanate group at the terminal is usually 0.5 to 40% by weight, preferably 1 to 30% by weight, and more preferably 2 to 20% by weight. If it is less than 0.5% by weight, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40% by weight, the low-temperature fixability deteriorates.
The number of isocyanate groups contained per molecule in the prepolymer having isocyanate groups is usually 1 or more, preferably 1.5 to 3 on average, and more preferably 1.8 to 2.5 on average. If it is less than 1 per molecule, the molecular weight of the modified polyester after crosslinking and / or elongation becomes low, and the hot offset resistance deteriorates.

(Crosslinking agent and extender)
In the present invention, amines can be used as a crosslinking agent and / or an extender. Examples of the amines include diamines, trivalent or higher polyamines, amino alcohols, amino mercaptans, amino acids, and those obtained by blocking the amino groups 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, isophoronediamine, etc. ); And aliphatic diamines (ethylenediamine, tetramethylenediamine, hexamethylenediamine, etc.) and the like.
Examples of the trivalent or higher polyamine include diethylenetriamine and triethylenetetramine. Examples of amino alcohols include ethanolamine and hydroxyethylaniline. Examples of amino mercaptans include aminoethyl mercaptan and aminopropyl mercaptan. Examples of amino acids include aminopropionic acid and aminocaproic acid. Examples of these amines in which the amino group is blocked include ketimine compounds and oxazoline compounds obtained from amines of these amines and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines, preferred are diamine and a mixture of a diamine and a small amount of a triamine or higher polyamine.

Furthermore, if necessary, the molecular weight of the modified polyester after completion of the reaction can be adjusted by using a terminator for crosslinking and / or elongation. Examples of the terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those blocked (ketimine compounds).
The ratio of amines is usually 1/2 to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the prepolymer having isocyanate groups and amino groups [NHx] in amines (B). 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. If [NCO] / [NHx] is greater than 2 or less than 1/2, the molecular weight of the urea-modified polyester (i) becomes low and the hot offset resistance deteriorates.

(Unmodified polyester)
In the present invention, not only the above-mentioned modified polyester prepolymer having an isocyanate group (hereinafter referred to as “modified polyester”) is used alone, but also the polyester prepolymer and an unmodified polyester (hereinafter referred to as “unmodified”). It is important to include the polyester as a toner binder component. By using the unmodified polyester together, the low temperature fixability and the glossiness and gloss uniformity when used in a full color apparatus are improved. Examples of the unmodified polyester include polycondensates of polyols and polycarboxylic acids similar to the polyester component of the modified polyester prepolymer, and preferred ones are also the same as those of the polyester prepolymer. The unmodified polyester is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, and may be modified with a urethane bond, for example. It is preferable that the modified polyester and the unmodified polyester are at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Accordingly, the polyester component of the modified polyester and the unmodified polyester are preferably similar in composition. When the modified polyester is contained, the weight ratio of the modified polyester to the unmodified polyester is usually 5/95 to 75/25, preferably 10/90 to 25/75, more preferably 12/88 to 25/75, particularly preferably. Is 12 / 88-22 / 78. If the weight ratio of the modified polyester is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.
The peak molecular weight of the unmodified polyester is usually 1000 to 30000, preferably 1500 to 10000, and more preferably 2000 to 8000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of the unmodified polyester is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of the unmodified polyester is usually 0.5 to 40, preferably 5 to 35. By having an acid value, it tends to be negatively charged. In addition, those having an acid value and a hydroxyl value exceeding these ranges are easily affected by the environment under high temperature and high humidity and low temperature and low humidity, and are liable to cause image deterioration.

In the present invention, the glass transition point (Tg) of the toner is usually 40 to 70 ° C., preferably 45 to 55 ° C. If it is less than 40 ° C., the heat-resistant storage stability of the toner deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Due to the coexistence of the cross-linked and / or elongated polyester resin, the toner of the present invention exhibits good storage stability even when the glass transition point is low, as compared with known polyester-based toners. As the storage elastic modulus of the toner, the temperature (TG ′) at which the measurement frequency is 20 Hz is 10000 dyn / cm ² is usually 100 ° C. or higher, preferably 110 to 200 ° C. If it is less than 100 ° C., the resistance to hot offset deteriorates. As the viscosity of the toner, the temperature (Tη) at which 1000 poise at a measurement frequency of 20 Hz is usually 180 ° C. or less, preferably 90 to 160 ° C. If it exceeds 180 ° C., the low-temperature fixability deteriorates. That is, from the viewpoint of achieving both low temperature fixability and hot offset resistance, TG ′ is preferably higher than Tη. In other words, the difference between TG ′ and Tη (TG′−Tη) is preferably 0 ° C. or higher. More preferably, it is 10 degreeC or more, Most preferably, it is 20 degreeC or more. The upper limit of the difference is not particularly limited. Further, from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability, the difference between Tη and Tg is preferably 0 to 100 ° C. More preferably, it is 10-90 degreeC, Most preferably, it is 20-80 degreeC.

(Coloring agent)
As the colorant of the present invention, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide , Ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa Yellow (GR, A, RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow ( 5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red , Fais red, parachlorol Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake , Thioindigo red B, thioindigo maroon, oil red, quinacridone red, pyrazolone , Polyazo red, chrome vermillion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue rake, peacock blue rake, Victoria blue rake, metal free phthalocyanine blue, phthalocyanine blue, fast sky blue, in Dunslen Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake Phthalocyanine green, anthraquinone green, titanium oxide, zinc white, lithobon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

The colorant used in the present invention can also be used as a master batch combined with a resin.
As the binder resin to be kneaded together with the production of the masterbatch or the masterbatch, in addition to the modified and unmodified polyester resins mentioned above, styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene, and polymers of substituted products thereof; Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α- Chloromethyl methacrylate copolymer, Tylene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid Styrene copolymers such as acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, poly Acrylic resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. can be used alone or in combination. The
This master batch can be obtained by mixing and kneading a resin for a master batch and a colorant under a high shear force to obtain a master batch. At this time, an organic solvent can be used to enhance the interaction between the colorant and the resin. In addition, a so-called flushing method, which is a wet cake of a coloring agent, is a method of mixing and kneading an aqueous paste containing water of a coloring agent together with a resin and an organic solvent, transferring the coloring agent to the resin side, and removing moisture and organic solvent components. Can be used as it is, so that it is not necessary to dry and is preferably used. For mixing and kneading, a high shear dispersion device such as a three-roll mill is preferably used.

(Release agent)
Further, a wax may be contained together with the toner binder and the colorant. Known waxes can be used as the wax of the present invention, such as polyolefin wax (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbon (paraffin wax, sasol wax, etc.); carbonyl group-containing wax, etc. It is done. Of these, carbonyl group-containing waxes are preferred. Carbonyl group-containing waxes include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18. -Octadecanediol distearate, etc.); polyalkanol esters (trimellitic acid tristearyl, distearyl maleate, etc.); polyalkanoic acid amides (ethylenediamine dibehenyl amide, etc.); polyalkylamides (trimellitic acid tristearyl amide, etc.) And dialkyl ketones (such as distearyl ketone). Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred. The melting point of the wax of the present invention is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C. A wax having a melting point of less than 40 ° C. has an adverse effect on heat resistant storage stability, and a wax having a melting point of more than 160 ° C. tends to cause a cold offset when fixing at a low temperature. Further, the melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps have poor effects for improving hot offset resistance and low-temperature fixability. The content of the wax in the toner is usually 0 to 40% by weight, preferably 3 to 30% by weight.

(Charge control agent)
The toner of the present invention may contain a charge control agent as necessary. All known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified). Quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Nitronine-based dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, oxynaphthoic acid metal complex E-82, salicylic acid metal complex E- 84, E-89 of phenol-based condensate (above, manufactured by Orient Chemical Industries), TP-302, TP-415 of quaternary ammonium salt molybdenum complex (above, manufactured by Hodogaya Chemical Co., Ltd.), quaternary ammonium Copy charge PSY VP2038 of salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit Co., Ltd.), copper phthalocyanine, perylene, quinacridone Azo pigments, sulfonate group, carboxyl group, and polymer compounds having a functional group such as a quaternary ammonium salt.
In the present invention, the amount of charge control agent used is determined by the toner production method including the type of binder resin, the presence or absence of additives used as necessary, and the dispersion method, and is uniquely limited. However, it is preferably used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the main charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the flowability of the developer is reduced, and the image density is reduced. Incurs a decline. These charge control agents can be dissolved and dispersed after being melt-kneaded with a masterbatch and resin, and of course, they can be added directly when dissolved and dispersed in an organic solvent, or fixed on the toner surface after preparation of toner particles. May be.

(External additive)
As an external additive for assisting fluidity, developability and chargeability of the colored particles obtained in the present invention, in addition to oxide fine particles, inorganic fine particles and hydrophobized inorganic fine particles are used in combination as external additives. It is more desirable that the primary particles subjected to the hydrophobization treatment contain at least one kind of inorganic fine particles having an average particle diameter of 1 to 100 nm, more preferably 5 nm to 70 nm. Further, it is more preferable that the hydrophobized primary particles contain at least one kind of inorganic fine particles having an average particle diameter of 20 nm or less and at least one kind of inorganic fine particles of 30 nm or more. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g.
Any of them can be used as long as the conditions are satisfied. For example, silica fine particles, hydrophobic silica, fatty acid metal salts (such as zinc stearate and aluminum stearate), metal oxides (such as titania, alumina, tin oxide, and antimony oxide), fluoropolymers, and the like may be contained.
Particularly suitable additives include hydrophobized silica, titania, titanium oxide, and alumina fine particles. Silica fine particles include HDK H 2000, HDK H 2000/4, HDK H 2050EP, HVK21, HDK H 1303 (above Hoechst) and R972, R974, RX200, RY200, R202, R805, and R812 (above Nippon Aerosil). Further, as titania fine particles, P-25 (Nippon Aerosil), STT-30, STT-65C-S (above Titanium Industry), TAF-140 (Fuji Titanium Industry), MT-150W, MT-500B, MT-600B MT-150A (taker above). In particular, as hydrophobized titanium oxide fine particles, T-805 (Nippon Aerosil), STT-30A, STT-65S-S (above Titanium Industry), TAF-500T, TAF-1500T (above Fuji Titanium Industry), MT -100S, MT-100T (above Taka), IT-S (Ishihara Sangyo), etc.

In order to obtain hydrophobized oxide particles, silica particles, titania particles, and alumina particles, hydrophilic particles are treated with a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane, or octyltrimethoxysilane. Can be obtained. In addition, silicone oil-treated oxide fine particles and inorganic fine particles obtained by treating silicone oil with heat if necessary to treat it with inorganic fine particles are also suitable.
Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, chlorophenyl silicone oil, methyl hydrogen silicone oil, alkyl-modified silicone oil, fluorine-modified silicone oil, polyether-modified silicone oil, alcohol-modified silicone oil, and amino-modified silicone. Oil, epoxy-modified silicone oil, epoxy-polyether-modified silicone oil, phenol-modified silicone oil, carboxyl-modified silicone oil, mercapto-modified silicone oil, acrylic, methacryl-modified silicone oil, α-methylstyrene-modified silicone oil and the like can be used. Examples of the inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, iron oxide, copper oxide, zinc oxide, tin oxide, silica sand, clay, mica, silica ash Examples thereof include stone, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, parium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Of these, silica and titanium dioxide are particularly preferred.
The addition amount can be 0.1 to 5% by weight, preferably 0.3 to 3% by weight, based on the toner. The average particle size of the primary particles of the inorganic fine particles is 100 nm or less, preferably 3 nm or more and 70 nm or less. If it is smaller than this range, the inorganic fine particles are buried in the toner, and the function is hardly exhibited effectively. On the other hand, if it is larger than this range, the surface of the photoreceptor is undesirably damaged.
In addition, polymer fine particles such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, polycondensation systems such as methacrylic acid ester and acrylic acid ester copolymer, silicone, benzoguanamine, and nylon, thermosetting Examples thereof include polymer particles made of a resin.

Such a fluidizing agent can be surface-treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. .
Examples of the cleaning property improver for removing the developer after transfer remaining on the photoreceptor or the primary transfer medium include, for example, zinc stearate, calcium stearate, fatty acid metal salts such as stearic acid, such as polymethyl methacrylate fine particles, polystyrene fine particles, etc. And polymer fine particles produced by soap-free emulsion polymerization. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.

(Production method)
The toner binder can be produced by the following method. Polyester having a hydroxyl group by heating the polyol and polycarboxylic acid to 150-280 ° C. in the presence of a known esterification catalyst such as tetrabutoxy titanate, dibutyltin oxide, etc. Get. Next, this is reacted with polyisocyanate at 40 to 140 ° C. to obtain a modified polyester having an isocyanate group.
The dry toner of the present invention can be produced by the following method, but is not limited thereto.

(Toner production method in aqueous medium)
The aqueous phase used in the present invention is used by adding resin fine particles in advance. The water used for the aqueous phase may be water alone, or a solvent miscible with water may be used in combination. Examples of the miscible solvent include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methylcellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.) and the like.
The toner particles are obtained by forming a dispersion made of a modified polyester, which is a polyester prepolymer having an isocyanate group dissolved or dispersed in an organic solvent in an aqueous phase, by reacting with amines. Examples of a method for stably forming a dispersion composed of a modified polyester in an aqueous phase include a method in which a composition of a toner raw material composed of a modified polyester dissolved or dispersed in an organic solvent is added to an aqueous phase and dispersed by shearing force. Is mentioned. A modified polyester dissolved or dispersed in an organic solvent and another toner composition (hereinafter referred to as “toner raw material”). Colorant, colorant masterbatch, release agent, charge control agent, unmodified The polyester resin or the like may be mixed when forming the dispersion in the aqueous phase, but after the toner raw material is mixed in advance and dissolved or dispersed in an organic solvent, the mixture is added to the aqueous phase and dispersed. Is more preferable. In the present invention, other toner raw materials such as a colorant, a release agent, and a charge control agent do not necessarily have to be mixed when forming particles in the aqueous phase. It may be added. For example, after forming particles containing no colorant, the colorant can be added by a known dyeing method.

The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. In order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing type is preferable. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C. Higher temperatures are preferable in that the dispersion made of the modified polyester has a low viscosity and is easily dispersed.
The amount of the aqueous phase used is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight, based on 100 parts of the toner composition containing the modified polyester. If the amount is less than 50 parts by weight, the dispersion state of the toner composition is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical. Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.

Anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino acids as dispersants for emulsifying and dispersing the oily phase in which the toner composition is dispersed in the aqueous phase Alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, quaternary ammonium such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride Nonionic surfactants such as salt-type cationic surfactants, fatty acid amide derivatives, polyhydric alcohol derivatives, such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N - Amphoteric surfactants such as chill ammonium betaine.
Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Examples of the anionic surfactant having a fluoroalkyl group preferably used include fluoroalkylcarboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [omega-fluoroalkyl (C6-C11). ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [omega-fluoroalkanoyl (C6-C8) -N-ethylamino] -sodium propanesulfonate, fluoroalkyl (C11-C20) carboxylic acid and Metal salt, perfluoroalkylcarboxylic acid (C7 to C13) and its metal salt, perfluoroalkyl (C4 to C12) sulfonic acid and its metal salt, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- (2 hydroxyethyl ) Par Luooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned,
Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Taikin Kogyo Co., Ltd.), Mega-Fac F-ll0, F-120, F-113, F-191, F-812, F-833 (Dainippon Ink Co., Ltd.), Xtop EF- 102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fagento F-100, F150 (manufactured by Neos).

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

  Further, tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite and the like can be used as an inorganic compound dispersant which is hardly soluble in water. The resin that forms resin fine particles as the dispersant is not particularly limited as long as it is a resin that can form an aqueous dispersion in addition to the crystalline polyester described above, and any one of a thermoplastic resin and a thermosetting resin can be used. But it can also be used. In addition, when an acid such as calcium phosphate salt or an alkali-soluble substance is used as the dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. To do. It can also be removed by operations such as enzymatic degradation. When a dispersant is used, the dispersant may remain on the surface of the toner particles, but it is preferable from the charged surface of the toner that the dispersant is washed and removed after the elongation and / or crosslinking reaction.

The elongation and / or cross-linking reaction time is selected depending on the reactivity depending on the combination of the isocyanate group structure of the modified polyester and amines, and is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.
In order to remove the organic solvent from the obtained emulsified dispersion, a method can be employed in which the temperature of the entire system is gradually raised and the organic solvent in the droplets is completely evaporated and removed. Alternatively, it is also possible to spray the emulsified dispersion in a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and to evaporate and remove the aqueous dispersant together. . As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, in particular, various air streams heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used are generally used. Sufficient quality can be obtained with a short treatment such as spray dryer, belt dryer or rotary kiln.
Further, as a method for removing the organic solvent, air can be blown away by a rotary evaporator or the like.
Thereafter, rough separation is performed by centrifugal separation, the emulsified dispersion is washed in a washing tank, and the drying process is repeated in a hot air dryer, and the solvent is removed and dried to obtain a toner base.
Thereafter, a ripening step is further performed, so that the hollow state inside the toner can be controlled, which is more preferable. It is preferably 30 to 55 ° C. (more preferably 40 to 50 ° C.), and more preferably aging for 5 to 36 hours (more preferably 10 to 24 hours).

When the particle size distribution at the time of emulsification dispersion is wide, and washing and drying processes are performed while maintaining the particle size distribution, the particle size distribution can be adjusted by classification into a desired particle size distribution.
In the classification operation, the fine particle portion can be removed in the liquid by a cyclone, a decanter, centrifugation, or the like. Of course, the classification operation may be performed after obtaining the powder as a powder after drying. The unnecessary fine particles or coarse particles obtained can be returned to the kneading step and used for the formation of particles. At that time, fine particles or coarse particles may be wet.
The dispersant used is preferably removed from the obtained dispersion as much as possible, but it is preferable to carry out it simultaneously with the classification operation described above.
Mixing or giving mechanical impact force to the powder mixture after drying with different types of particles such as release agent fine particles, charge control fine particles, fluidizing agent fine particles, and colorant fine particles By immobilizing and fusing on the surface, it is possible to prevent detachment of foreign particles from the surface of the resulting composite particle.
Specific means include a method of applying an impact force to the mixture by blades rotating at high speed, a method of injecting and accelerating the mixture in a high-speed air stream, and causing particles or composite particles to collide with an appropriate collision plate, etc. is there. As equipment, Ong mill (manufactured by Hosokawa Micron Co., Ltd.), I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) has been modified to reduce the pulverization air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), automatic mortar, etc.
Finally, an external additive such as inorganic fine particles and a toner are mixed with a Henschel mixer or the like, and coarse particles are removed with an ultrasonic sieve or the like to obtain a final toner.

(Carrier for two components)
When the toner of the present invention is used for a two-component developer, it may be used by mixing with a magnetic carrier, and the content ratio of the carrier and the toner in the developer is 1 to 10 wt. Part is preferred. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used. Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene acrylic copolymer resins, Halogenated olefin resins such as vinyl, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoro Propylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride And fluoro such as terpolymers of non-fluoride monomers including, and silicone resins. Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance.
In addition, the developer of the present invention uses a core-shell toner, so that it is possible to ensure a sufficient rise in charge potential of the toner by friction charging in a short time, and a sufficiently sharp charge amount distribution is obtained. It is more preferable because it can be maintained.
The toner of the present invention can also be used as a one-component magnetic toner that does not use a carrier or a non-magnetic toner.

(Tandem color image forming device)
The present invention can also be used as a color image forming apparatus of a tandem development system in which at least four development units having different development colors are arranged in series. An example of an embodiment of a tandem type color image forming apparatus will be described. FIG. 3 is a schematic diagram showing the configuration of the main part of the direct transfer tandem color image forming apparatus. FIG. 4 is a schematic diagram showing a configuration of a main part of a tandem color image forming apparatus having an indirect transfer type intermediate transfer belt.
In the tandem type color image forming apparatus 1, as shown in FIG. 3, the images on the photoconductors 3Y, 3C, 3M, and 3K are sequentially transferred by the transfer device 50 to the recording member 9 that is conveyed by the recording and conveying belt 56. As shown in FIG. 4, the images on the photoreceptors 3Y, 3C, 3M, and 3K are sequentially transferred to an intermediate transfer belt 51, which is an intermediate transfer member, by a primary transfer roller 52 as shown in FIG. Thereafter, there is an indirect transfer type in which images on the intermediate transfer belt 51 are collectively transferred to a recording member 9 by a secondary transfer roller 54.
Comparing the direct transfer type with the indirect transfer type, the former is a paper feed device 60 on the upstream side of the tandem type image forming apparatus in which the photoreceptors 3Y, 3C, 3M, and 3K are arranged, and the downstream side. The fixing device 70 must be disposed, and there is a disadvantage that the fixing device 70 is increased in size in the conveyance direction of the recording member 9. On the other hand, the latter can set the secondary transfer position relatively freely. The paper feeding device 60 and the fixing device 70 can be arranged so as to overlap with the tandem type image forming apparatus, which is advantageous in that the size can be reduced.
In the former, in order not to increase the size of the recording member 9 in the conveying direction, the fixing device 70 is disposed close to the tandem type image forming apparatus. Therefore, the fixing device 70 cannot be disposed with a sufficient margin that the recording member 9 can bend, and an impact when the leading end of the recording member 9 enters the fixing device (particularly with the thick recording member 9). In addition, there is a drawback that the fixing device 70 is liable to affect the image formation on the upstream side due to the speed difference between the conveyance speed of the recording member 9 when passing the fixing device 70 and the conveyance speed of the recording member 9 by the conveyance belt 56. is there. On the other hand, in the latter case, since the fixing device 70 can be disposed with a sufficient margin that the recording member 9 can bend, the fixing device 70 can hardly affect the image formation.
In view of the above, recently, an indirect transfer type of tandem type electrophotographic apparatus has attracted attention.
In this type of color electrophotographic apparatus, as shown in FIG. 4, the transfer residual toner remaining on the photoconductor 3 after the primary transfer is removed by the photoconductor cleaning device 20 to clean the surface of the photoconductor 3. In preparation for image formation again. Further, the transfer residual toner remaining on the intermediate transfer belt 51 after the secondary transfer is removed by a transfer body cleaning device while not shown in the middle to clean the surface of the intermediate transfer belt 51 and prepare for another image formation.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 5 shows an embodiment of the present invention, which is a tandem indirect transfer type image forming apparatus. The image forming apparatus 1 is provided with a paper feeding section 7 on which the image forming section 6 is placed. In addition, a scanner reading section 4 mounted on the image forming apparatus 1 and an automatic document feeder (ADF) mounted thereon. 5. The copying apparatus main body is provided with an intermediate transfer belt 51 which is an endless belt-like intermediate transfer member at the center.
In the tandem type image forming apparatus 1, the process cartridge 2 serving as individual image forming means is more specifically shown in FIG. 2, for example, around a drum-shaped photoreceptor 3, a charging device 10, a developing device 40, 1. The image forming apparatus includes a transfer device 50 having a next transfer roller 52, a photoconductor cleaning device 20, a static elimination device (not shown), and the like. Then, as shown in FIG. 5, in the illustrated example, it is wound around three support rollers 531, 532, and 533 so as to be able to rotate and convey clockwise in the drawing.
In this illustrated example, it is preferable to provide an intermediate transfer member cleaning device for removing residual toner remaining on the intermediate transfer belt 51 after image transfer, to the left of the second support roller among the three.
In addition, on the intermediate transfer belt 51 stretched between the first support roller 531 and the second support roller 532 among the three, yellow, cyan, magenta, and black 4 are arranged along the transport direction. The tandem type image forming apparatus 1 is configured by horizontally arranging two image forming units.
An exposure device 80 is further provided on the tandem type image forming apparatus 1 as shown in FIG. On the other hand, a secondary transfer roller 54 is provided with the intermediate transfer belt 51 interposed therebetween. The secondary transfer roller 54 is disposed by being pressed against the third support roller 533 via the intermediate transfer belt 51, and transfers the image on the intermediate transfer belt 51 to the recording member 9.
A fixing device 70 for fixing the transfer image on the recording member 9 is provided beside the secondary transfer roller 54. In the illustrated example, the recording member 9 is reversed under the secondary transfer roller 54 and the fixing device 70 so as to record images on both surfaces of the recording member 9 in parallel with the tandem image forming apparatus described above. A member reversing device 69 is provided.
Now, when making a copy using this full-color image forming apparatus, the original is set on the original table of the automatic original feeder 5. Alternatively, the automatic document feeder 5 is opened, a document is set on the contact glass 403 of the scanner 4, and the automatic document feeder 5 is closed and pressed by it.
When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 5, the document is transported and moved onto the contact glass 403, and then the document is set on the other contact glass. At that time, the scanner 4 is immediately driven and the first traveling body 405 and the second traveling body 407 travel. Then, the first traveling body 405 emits light from the light source 404 and the reflected light from the document surface is input to the reading sensor 410 through the imaging lens 409 to read the content of the document.
When a start switch (not shown) is pressed, one of the support rollers is rotationally driven by a drive motor (not shown), the other two support rollers are driven to rotate, and the intermediate transfer belt 51 is rotated and conveyed. At the same time, the individual image forming units 6 rotate the photoconductor 3 with the process cartridge 2 of the image forming unit, and monochrome images of black, yellow, magenta, and cyan are respectively formed on the photoconductors 3Y, 3C, 3M, and 3K. Form. As the intermediate transfer belt 51 is conveyed, the single color images are sequentially transferred to form a composite color image on the intermediate transfer belt 51.
On the other hand, when a start switch (not shown) is pressed, one of the paper feeding rollers 62 of the paper feeding cassette 61 is selectively rotated, and the recording member 9 is fed out from one of the paper feeding cassettes 61 provided in multiple stages. Each sheet is separated and put into a paper feed path, transported by a transport roller 63, guided to a paper feed path in the image forming apparatus 1, and abutted against a registration roller 64 and stopped.
Alternatively, the sheet feeding roller 63 is rotated to feed out the recording member 9 on the manual feed tray 68, separated one by one by the separation roller 65, put into the manual feed path, and abutted against the registration roller 64 and stopped.
Then, the registration roller 64 is rotated in synchronization with the composite color image on the intermediate transfer belt 51, the recording member 9 is fed between the intermediate transfer belt 51 and the secondary transfer roller 54, and transferred by the secondary transfer roller 54. Then, a color image is recorded on the recording member 9.
After the image transfer, the recording member 9 is conveyed by the conveying belt 56 and sent to the fixing device 70. The fixing device 70 applies heat and pressure to fix the transferred image, and then the recording member 9 is switched by a switching claw (not shown) and discharged. The paper is discharged by a roller 93 and stacked on a paper discharge tray 91. Alternatively, it is switched by a switching claw (not shown) and put into the recording member reversing device 69, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then ejected onto the paper ejection tray 91 by the ejection roller 93. .
On the other hand, the intermediate transfer belt 51 after the image transfer is removed by an intermediate transfer body cleaning device to remove residual toner remaining on the intermediate transfer belt 51 after the image transfer, so that the tandem type image forming apparatus 1 can prepare for another image formation. Here, the registration roller 64 is generally used while being grounded, but it is also possible to apply a bias in order to remove paper dust from the recording member 9.

The image forming apparatus 1 of the present invention further includes a fixing device 70 that fixes the visible image on the recording medium 9 by heat and pressure.
FIG. 6 is a diagram showing a configuration of a fixing device used in the image forming apparatus of the present invention.
Here, a heating roller is shown as the fixing member.
In the fixing device 70 of the present invention, as shown in FIG. 6, the fixing roller 71 is formed of, for example, foamed silicone rubber in order to form a nip with the pressure roller 72 on the outer periphery of a metal core such as stainless steel or aluminum. And an elastic layer formed into a ring shape with a heat-resistant elastic material such as liquid silicone rubber. A surface layer is provided on the surface layer of the elastic layer in order to improve the releasability of transfer paper and toner. For the surface layer, a material having heat resistance and low surface energy is used.
A heat source such as a halogen heater for accelerating the temperature rise of the fixing roller 71 is disposed in the core of the fixing roller 71.
The pressure roller 72 includes an elastic layer made of a heat-resistant elastic material such as fluorine-based rubber or silicone rubber with an appropriate thickness on the outer periphery of a metal core such as stainless steel or aluminum. A surface layer made of a resin or the like is provided in order to impart the properties. The pressure roller 72 is pressed against the fixing roller 71 by a pressure member such as a spring (not shown), and pressurizes the toner with the fixing roller 71 for a certain period of time by elastically deforming the elastic layer. -Form a nip that can be heated. Further, a temperature sensor such as a thermistor may be provided to detect the temperature of each member in order to control the heaters of the members in the fixing device 70 such as the fixing roller 71 and the pressure roller 72.
Here, a description will be given particularly in relation to the pressure applied by the fixing device 70 and the fixing roller 71 and the like. Unfixed toner on the recording medium 9 is melted by the heat and pressure on the fixing roller 71 and fixed on the recording medium 9 such as paper or an OHP resin film.
As a toner, a toner having a core-shell structure having a core and a shell layer having a thickness of 0.01 μm to 2 μm on the surface of the core, the softening temperature ST of the shell layer and the softening temperature CT of the inner core are 1 .Ltoreq.CT / ST.ltoreq.2.5 When the relational expression (1) of the expression (1) is satisfied, the system speed of the fixing device 70 such as the fixing roller 71 is 500 to 2500 mm / sec, and the fixing roller. 71, pressing surface pressure of the fixing medium pressure roller 72 ^{is 5N / cm 2 ~90N / cm 2} .
If the system speed is less than 500 mm / sec, hot offset may occur, and the image after fixing may be smudged. When the system speed exceeds 2500 mm / sec, fixing failure occurs, and the image after fixing may peel off. On the other hand, when the pressing surface pressure is less than 5 N / cm ² , hot offset occurs, and the image after fixing may be stained. When the pressing surface pressure exceeds 90 N / cm ² , fixing failure occurs, and the image after fixing may peel off. Therefore, sufficient fixability can be obtained even in the image forming apparatus 1 having a high system speed.
As the fixing device 70, a fixing means using a roller provided with a heating device, a fixing means using a belt provided with a heating device, or the like can be used. Here, an oilless fixing unit using a fixing roller 71 and a pressure roller 72 that do not require oil application to the fixing member is preferable. It is possible to meet the demand for low-temperature fixing in high-speed printing, and it is possible to obtain an image having a sufficiently strong fixing strength even in a situation where the supplied fixing heat quantity is insufficient.

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto. Hereinafter, a part shows a weight part.
(Evaluation machine)
As an evaluation machine, the developing part and fixing part of imagio MP C6000 were modified and used. The modified contents were used with the development gap of 1.26 mm, the doctor blade gap of 1.6 mm, and the reflective photosensor function turned off so that the linear velocity was 1700 mm / sec. The fixing unit of the fixing unit had a fixing surface pressure of 39 N / cm ² and a fixing nip width of 10 mm. The surface of the fixing medium was coated with tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA), molded, and surface-adjusted. The actual temperature regions of the image carrier, the developing device, and the transfer device unit were controlled to be 30 to 45 ° C. The heating temperature of the fixing roller was set to 150 ° C.

(Evaluation of two-component developer)
When evaluating an image with a two-component developer, a ferrite carrier having an average particle diameter of 35 μm coated with a silicone resin with an average thickness of 0.5 μm is used as follows. The developer was prepared by uniformly mixing and charging parts by weight using a type of tumbler mixer in which the container was rolled and stirred.
(Carrier production)
・ Core material: Mn ferrite particles (weight average diameter: 35 μm) 5000 parts ・ Coating material Toluene: 450 parts Silicone resin SR2400: 450 parts (made by Toray Dow Corning Silicone, nonvolatile content 50%)
Aminosilane SH6020: 10 parts (made by Toray Dow Corning Silicone)
Carbon black: 10 parts The above coating material is dispersed with a stirrer for 10 minutes to prepare a coating solution, and this coating solution and core material are coated while forming a swirling flow in which a rotating bottom plate disk and stirring blades are provided in a fluidized bed. The coating solution was applied to the core material. The obtained coated product was baked in an electric furnace at 250 ° C. for 2 hours to obtain the carrier.

Example 1
-Synthesis of resin particles 1-
Production Example 1
[Synthesis of resin materials]
-Synthesis of crystalline polyester resin 1-
To a heat-dried three-necked flask, 120.0 parts by weight of 1,10-decanediol, 80.0 parts by weight of sodium dimethyl 5-sulfoisophthalate, 4 parts by weight of dimethyl sulfoxide, and 0.02 of dibutyltin oxide as a catalyst Then, the air in the container was brought into an inert atmosphere with nitrogen gas by a depressurization operation, and stirred at 180 ° C. for 3 hours by mechanical stirring. Dimethyl sulfoxide was distilled off under reduced pressure, 23.0 parts by weight of dimethyl dodecanedioic acid was added under a nitrogen stream, and the mixture was stirred at 160 ° C. for 45 minutes.
Thereafter, the temperature was gradually raised to 220 ° C. under reduced pressure, and the mixture was stirred for 30 minutes. When it became viscous, it was cooled with air, the reaction was stopped, and a crystalline polyester resin 1 was synthesized.
The polyester resin had a glass transition temperature of 70 ° C. The number average molecular weight was 4,200 and the weight average molecular weight was 18,000. Moreover, the acid value by KOH titration of this resin was 10 mgKOH / g.

-Synthesis of non-crystalline polyester resin 1-
In a heat-dried three-necked flask, 112 parts by weight of dimethyl naphthalenedicarboxylate, 97 parts by weight of dimethyl terephthalate, 221 parts by weight of bisphenol A-ethylene oxide 2 mol adduct, 80 parts by weight of ethylene glycol, 0.07 parts by weight of tetrabutoxy titanate Were transesterified by heating at 170-220 ° C. for 180 minutes. Subsequently, as a result of continuing reaction for 45 minutes at 220 degreeC and the system pressure of 1-10 mmHg, the amorphous polyester resin 1 was obtained. The polyester resin had a glass transition temperature of 64 ° C. The number average molecular weight was 3200 and the weight average molecular weight was 17,000. Moreover, the acid value by KOH titration of this resin was 10 mgKOH / g.

-Preparation of resin fine particle dispersion 1-
The above-mentioned crystalline polyester resin 1 was coarsely pulverized with a hammer mill to prepare a resin particle dispersion.
50 parts by weight of ethyl acetate and 110 parts by weight of IPA were added to a 2 L separable flask equipped with an anchor blade that gives stirring power, a reflux device, and a decompression device using a vacuum pump, and N2 was accelerated at a rate of 0.2 L / m. to replace the air in the system with N _2. Next, 200 parts by weight of the crystalline polyester resin 1 was slowly added while being heated to 60 ° C. by an in-system oil bath device, and dissolved while stirring. Next, 20 parts by weight of 10% ammonia water was added thereto, and then 460 parts by weight of ion-exchanged water was added thereto at a rate of 9.6 g / m while stirring using a metering pump. Emulsification was completed when the emulsification system was milky white and the stirring viscosity was reduced.
Next, the pressure was reduced to -700 Torr, and the mixture was stirred for 40 minutes while stirring. Further, 50 parts by weight of pure water at 60 ° C. was added thereto, and stirring was continued for 20 minutes under reduced pressure. When the reflux amount reached 210 parts by weight, this was taken as the end point, and overheating was stopped and the mixture was cooled to room temperature while stirring. The particle size of the obtained resin particles was measured using a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.). The average particle size of the obtained resin fine particles was 294 nm.

-Adjustment of aqueous phase-
Production Example 2
500 parts of water, 83 parts of [resin fine particle dispersion 1], 23 parts of a 48.3% aqueous solution of dodecyl diphenyl ether disulfonate (Eleminol MON / -7: manufactured by Sanyo Chemical Industries) and 50 parts of ethyl acetate are mixed. Agitation gave a milky white liquid. This is designated as [Aqueous Phase 1].

~ Synthesis of amorphous low molecular weight polyester ~
Production Example 3
229 parts of bisphenol A ethylene oxide 2-mole adduct, 329 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts of terephthalic acid, 80 parts of adipic acid and dibutyl 2 parts of tin oxide was added, reacted at 230 ° C. for 7 hours at normal pressure, and further reacted for 5 hours at a reduced pressure of 10-15 mmHg /, and then 35 parts of trimellitic anhydride was added to the reaction vessel at 180 ° C., normal pressure To give [Amorphous low molecular weight polyester 1]. [Amorphous low molecular weight polyester 1] had a number average molecular weight of 2000, a weight average molecular weight of 3800, Tg / 40 ° C., and an acid value of 25.

~ Synthesis of non-crystalline intermediate polyester ~
Production Example 4
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 Part and 2 parts of dibutyltin oxide were added, reacted at 230 ° C. for 7 hours at normal pressure, and further reacted for 5 hours at a reduced pressure of 10 to 15 mmHg / to obtain [Amorphous Intermediate Polyester 1]. [Amorphous Intermediate Polyester 1] had a number average molecular weight of 2200, a weight average molecular weight of 9700, Tg / 54 ° C., an acid value of 0.5 and a hydroxyl value of 52.
Next, 410 parts of [Amorphous Intermediate Polyester 1], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe and reacted at 100 ° C. for 5 hours. [Prepolymer 1] was obtained. [Prepolymer 1] had a free isocyanate weight percentage of 1.53%.

~ Synthesis of ketimine ~
Production Example 5
In a reaction vessel equipped with a stirrer and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 4 and a half hours to obtain [ketimine compound 1]. The amine value of [ketimine compound 1] was 417.

~ Synthesis of master batch (MB) ~
Production Example 6
Add 1200 parts of water, 540 parts of carbon black (manufactured by Printex 35 Dexa) [DBP oil absorption = 42 mL / 100 mg, pH = 9.5], 1200 parts of polyester resin, and mix with a Henschel mixer (Mitsui Mining Co., Ltd.). After kneading at 110 ° C. for 1 hour using two rolls, rolling and cooling and pulverizing with a pulverizer, [Masterbatch 1] was obtained.

~ Creation of oil phase ~
Production Example 7
378 parts of [Non-crystalline low molecular weight polyester 1], 100 parts of Carnauba WAX, and 947 parts of ethyl acetate are charged in a container equipped with a stir bar and a thermometer. The temperature is raised to 80 ° C. with stirring and the temperature is kept at 80 ° C. for 5 hours. After holding, it was cooled to 30 ° C. at 1 hour. Next, 500 parts of [Masterbatch 1] and 500 parts of ethyl acetate were placed in a container and mixed for 1 hour to obtain [Raw material solution 1].
[Raw Material Solution 1] 1324 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), liquid feeding speed is 1 kg / hr, disk peripheral speed is 6 m / sec, and 0.5% zirconia beads are 80% by volume. Carbon black and WAX were dispersed under conditions of filling and 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of [Non-crystalline low molecular weight polyester 1] was added, followed by two passes with a bead mill under the above conditions to obtain [Pigment / WAX Dispersion 1]. The solid content concentration of [Pigment / WAX Dispersion 1] (130 ° C., 30 minutes) was 50%.

~ Emulsification⇒Desolvation ~
Production Example 8
[Pigment / WAX Dispersion 1] 749 parts, [Prepolymer 1] 115 parts, [Ketimine Compound 1] 2.9 parts in a container and TK homomixer (manufactured by Tokushu Kika) for 2 minutes at 5,000 rpm After mixing, 1200 parts of [Aqueous Phase 1] was added to the container, and mixed with a TK homomixer at 13,000 rpm for 25 minutes to obtain [Emulsion Slurry 1].
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C for 8 hours, aging was performed at 40 ° C for 24 hours to obtain [Dispersion slurry 1].

~ Washing⇒Drying ~
Production Example 9
[Dispersion Slurry 1] After filtering 100 parts under reduced pressure,
(1): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(2): 1OO parts of 10% aqueous sodium hydroxide solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure.
(3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(4): 300 parts of ion-exchanged water was added to the filter cake of (3), mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered twice to obtain [filter cake 1]. It was.
[Filter cake 1] was dried at 45 ° C. for 48 hours in a circulating drier. Thereafter, sieved with a mesh of 75 μm, [toner base particle 1] was obtained.
Thereafter, 100 parts of [toner base particle 1] and 1 part of hydrophobized silica having a particle diameter of 13 nm were mixed with a Henschel mixer to obtain a toner. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.

(Example 2)
A toner was obtained in the same manner as in Example 1 except that the resin fine particle dispersion 1 used in Example 1 was changed to the following. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.
-Adjustment of resin fine particle dispersion 2-
The above-mentioned crystalline polyester resin 1 was coarsely pulverized with a hammer mill to prepare a resin particle dispersion. 50 parts by weight of ethyl acetate and 110 parts by weight of IPA were added to a 2 L separable flask equipped with an anchor blade that gives stirring power, a reflux device, and a decompression device using a vacuum pump, and N2 was accelerated at a rate of 0.2 L / m. to replace the air in the system with N _2. Next, the crystalline polyester resin 1 while being heated to 60 ° C. by the internal oil bath device
200 parts by weight were slowly added and dissolved with stirring. Next, 20 parts by weight of 5% ammonia water was added thereto, and then 460 parts by weight of ion-exchanged water was added thereto at a rate of 4.0 g / m with stirring using a metering pump. Emulsification was completed when the emulsification system was milky white and the stirring viscosity was reduced.
Next, the pressure was reduced to -700 Torr, and the mixture was stirred for 40 minutes while stirring. Further, 50 parts by weight of pure water at 60 ° C. was added thereto, and stirring was continued for 20 minutes under reduced pressure. When the reflux amount reached 210 parts by weight, this was taken as the end point, and overheating was stopped and the mixture was cooled to room temperature while stirring. The particle size of the obtained resin particles was measured using a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.). The average particle size of the obtained resin fine particles was 834 nm.

(Example 3)
A toner was obtained in the same manner as in Example 1 except that the resin fine particle dispersion 1 used in Example 1 was changed to the following. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.
-Adjustment of resin fine particle dispersion 3-
The above-mentioned crystalline polyester resin 1 and amorphous polyester resin 1 were coarsely pulverized with a hammer mill to prepare a resin particle dispersion. 50 parts by weight of ethyl acetate and 110 parts by weight of IPA were added to a ₂ L separable flask equipped with an anchor blade that gives stirring power, a reflux device, and a vacuum pump decompression device. and to replace the air in the system with N _2. Next, 150 parts by weight of crystalline polyester resin 1 and 50 parts by weight of amorphous polyester resin 1 were slowly added while being heated to 60 ° C. by an in-system oil bath apparatus, and dissolved while stirring. Next, 20 parts by weight of 5% ammonia water was added thereto, and then 460 parts by weight of ion-exchanged water was added thereto at a rate of 4.0 g / m with stirring using a metering pump. Emulsification was completed when the emulsification system was milky white and the stirring viscosity was reduced.
Next, the pressure was reduced to -700 Torr, and the mixture was stirred for 40 minutes while stirring. Further, 50 parts by weight of pure water at 60 ° C. was added thereto, and stirring was continued for 20 minutes under reduced pressure. When the reflux amount reached 210 parts by weight, this was taken as the end point, and overheating was stopped and the mixture was cooled to room temperature while stirring. The particle size of the obtained resin particles was measured using a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.). The average particle size of the obtained resin fine particles was 1020 nm.

Example 4
A toner was obtained in the same manner as in Example 1 except that the resin fine particle dispersion 1 used in Example 1 was changed to the following. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.
-Preparation of resin fine particle dispersion 4-
The above-mentioned crystalline polyester resin 1 and amorphous polyester resin 1 were coarsely pulverized with a hammer mill to prepare a resin particle dispersion.
50 parts by weight of ethyl acetate and 110 parts by weight of IPA were added to a ₂ L separable flask equipped with an anchor blade that gives stirring power, a reflux device, and a vacuum pump decompression device. and to replace the air in the system with N _2. Next, 100 parts by weight of the crystalline polyester resin 1 and 100 parts by weight of the amorphous polyester resin 1 were slowly added while being heated to 60 ° C. by an in-system oil bath apparatus, and dissolved while stirring. Next, 20 parts by weight of 10% ammonia water was added thereto, and then 460 parts by weight of ion-exchanged water was added thereto at a rate of 9.6 g / m while stirring using a metering pump. Emulsification was completed when the emulsification system was milky white and the stirring viscosity was reduced.
Next, the pressure was reduced to -700 Torr, and the mixture was stirred for 40 minutes while stirring. Further, 50 parts by weight of pure water at 60 ° C. was added thereto, and stirring was continued for 20 minutes under reduced pressure. When the reflux amount reached 210 parts by weight, this was taken as the end point, and overheating was stopped and the mixture was cooled to room temperature while stirring. The particle size of the obtained resin particles was measured using a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.). The average particle size of the obtained resin fine particles was 182 nm.

(Comparative Example 1)
A toner was obtained in the same manner as in Example 1 except that the organic fine particle emulsion used in Example 1 was changed to the following. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.
-Adjustment of resin fine particle dispersion 5-
The aforementioned amorphous polyester resin 1 was coarsely pulverized with a hammer mill to prepare a resin particle dispersion. 50 parts by weight of ethyl acetate and 110 parts by weight of IPA were added to a ₂ L separable flask equipped with an anchor blade that gives stirring power, a reflux device, and a vacuum pump decompression device. and to replace the air in the system with N _2. Next, 200 parts by weight of the crystalline polyester resin 1 was slowly added while being heated to 60 ° C. by an in-system oil bath device, and dissolved while stirring. Next, 20 parts by weight of 10% ammonia water was added thereto, and then 460 parts by weight of ion-exchanged water was added thereto at a rate of 20.0 g / m with stirring using a metering pump. Emulsification was completed when the emulsification system was milky white and the stirring viscosity was reduced.
Next, the pressure was reduced to -700 Torr, and the mixture was stirred for 40 minutes while stirring. Further, 50 parts by weight of pure water at 60 ° C. was added thereto, and stirring was continued for 20 minutes under reduced pressure. When the reflux amount reached 210 parts by weight, this was taken as the end point, and overheating was stopped and the mixture was cooled to room temperature while stirring. The particle size of the obtained resin particles was measured using a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.). The average particle size of the obtained resin fine particles was 53 nm.

(Comparative Example 2)
A toner was obtained in the same manner as in Example 1 except that the resin fine particle dispersion 1 used in Example 1 was changed to the following. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.
-Adjustment of resin fine particle dispersion 6-
The above-mentioned crystalline polyester resin 1 and amorphous polyester resin 1 were coarsely pulverized with a hammer mill to prepare a resin particle dispersion. 50 parts by weight of ethyl acetate and 110 parts by weight of IPA were added to a ₂ L separable flask equipped with an anchor blade that gives stirring power, a reflux device, and a vacuum pump decompression device. and to replace the air in the system with N _2. Next, the crystalline polyester resin 1 while being heated to 60 ° C. by the internal oil bath device
150 parts by weight and 50 parts by weight of amorphous polyester resin 1 were slowly added and dissolved with stirring. Next, 20 parts by weight of 1% aqueous ammonia was added thereto, and then 460 parts by weight of ion-exchanged water was added thereto at a rate of 2.0 g / m with stirring using a metering pump. Emulsification was completed when the emulsification system was milky white and the stirring viscosity was reduced.
Next, the pressure was reduced to -700 Torr, and the mixture was stirred for 40 minutes while stirring. Further, 50 parts by weight of pure water at 60 ° C. was added thereto, and stirring was continued for 20 minutes under reduced pressure. When the reflux amount reached 210 parts by weight, this was taken as the end point, and overheating was stopped and the mixture was cooled to room temperature while stirring. The particle size of the obtained resin particles was measured using a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.). The average particle size of the obtained resin fine particles was 1520 nm.

(Comparative Example 3)
A toner was obtained in the same manner as in Example 1 except that the resin fine particle dispersion 1 used in Example 1 was changed to the following. The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.
-Preparation of resin fine particle dispersion 7-
The above-mentioned crystalline polyester resin 1 and non-crystalline polyester resin 1 were coarsely pulverized with a hammer mill to prepare a resin particle dispersion. 50 parts by weight of ethyl acetate and 110 parts by weight of IPA were added to a ₂ L separable flask equipped with an anchor blade that gives stirring power, a reflux device, and a vacuum pump decompression device. and to replace the air in the system with N _2. Next, the crystalline polyester resin 1 while being heated to 60 ° C. by the internal oil bath device
10 parts by weight and 190 parts by weight of amorphous polyester resin 1 were slowly added and dissolved with stirring. Next, 20 parts by weight of 10% ammonia water was added thereto, and then 460 parts by weight of ion-exchanged water was added thereto at a rate of 9.6 g / m while stirring using a metering pump. Emulsification was completed when the emulsification system was milky white and the stirring viscosity was reduced.
Next, the pressure was reduced to -700 Torr, and the mixture was stirred for 40 minutes while stirring. Further, 50 parts by weight of pure water at 60 ° C. was added thereto, and stirring was continued for 20 minutes under reduced pressure. When the reflux amount reached 210 parts by weight, this was taken as the end point, and overheating was stopped and the mixture was cooled to room temperature while stirring. The particle size of the obtained resin particles was measured using a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.). The average particle size of the obtained resin fine particles was 270 nm.

(Comparative Example 4)
In Example 1, a toner was obtained in the same manner as in Example 1 except that the resin fine particle dispersion 1 used was changed to the following resin fine particle dispersion 8 and the desolvation process from emulsification of the toner was changed to the following. . The physical properties of the obtained toner are shown in Table 1, and the evaluation results are shown in Table 2.
-Preparation of resin fine particle dispersion 8-
The above-mentioned crystalline polyester resin 1 and amorphous polyester resin 1 were coarsely pulverized with a hammer mill to prepare a resin particle dispersion. 50 parts by weight of ethyl acetate and 110 parts by weight of IPA were added to a ₂ L separable flask equipped with an anchor blade that gives stirring power, a reflux device, and a vacuum pump decompression device. and to replace the air in the system with N _2. Next, 100 parts by weight of the crystalline polyester resin 1 and 100 parts by weight of the amorphous polyester resin 1 were slowly added while being heated to 60 ° C. by an in-system oil bath apparatus, and dissolved while stirring. Next, 20 parts by weight of 10% ammonia water was added thereto, and then 460 parts by weight of ion-exchanged water was added thereto at a rate of 9.6 g / m while stirring using a metering pump. Emulsification was completed when the emulsification system was milky white and the stirring viscosity was reduced.
Next, the pressure was reduced to -700 Torr, and the mixture was stirred for 40 minutes while stirring. Further, 50 parts by weight of pure water at 60 ° C. was added thereto, and stirring was continued for 20 minutes under reduced pressure. When the reflux amount reached 210 parts by weight, this was taken as the end point, and overheating was stopped and the mixture was cooled to room temperature while stirring. The particle size of the obtained resin particles was measured using a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.). The average particle size of the obtained resin fine particles was 182 nm.

~ Emulsification⇒Desolvation ~
[Pigment / WAX Dispersion 1] 749 parts, [Prepolymer 1] 115 parts, [Ketimine Compound 1] 2.9 parts in a container and TK homomixer (manufactured by Tokushu Kika) for 2 minutes at 5,000 rpm After mixing, 1200 parts of [Aqueous Phase 1] was added to the container, and mixed with a TK homomixer at 13,000 rpm for 60 minutes to obtain [Emulsified Slurry 2].
[Emulsion slurry 2] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 40 ° C. for 12 hours, aging was carried out at 45 ° C. for 72 hours to obtain [Dispersion slurry 2]. Thereafter, the toner was similarly manufactured and evaluated using [Dispersion Slurry 2] instead of [Dispersion Slurry 1].

(Evaluation item)
(1) Low-temperature fixability After outputting 10,000 sheets of 5% image area chart using the obtained two-component developer and an evaluation machine, the temperature of the fixing unit is changed by 5 ° C., and the image is output and fixed. Sex was measured. Ricoh full color PPC paper type 6200 was used as the transfer paper.
The fixing temperature of the fixing unit was changed, and a printed image having an image density of 1.2 by X-Rite 938 was obtained. The copy image at each temperature was rubbed 50 times with a clock meter equipped with a sand eraser, the image density before and after that was measured, and the fixing rate was determined by the following formula.
Fixing rate (%) = [(image density after 10 times of sand eraser) / (previous image density)] × 100
The temperature at which a fixing rate of 70% or more was achieved was defined as the minimum fixing temperature. The criteria for determining low temperature fixability are as follows.
The evaluation results are shown as follows.
A: Fixing starts at a very low temperature, the fixing minimum temperature is low, and the fixing property is very low.
○: considerably excellent in low-temperature fixability
(Triangle | delta): Low temperature fixability is superior to the conventional system.
×: Lower fixing limit is inferior to the conventional system (imagio MP C6000 unmodified product).
(2) Heat-resistant storage stability The toner was weighed 10 g at a time, put into a 20 mL glass container, and the glass bottle was tapped 100 times with a tapping machine, and then left in a constant temperature bath set at a temperature of 55 ° C. and a humidity of 80% for 72 hours. Then, the penetration was measured with a penetration tester (conditions described in the Nikka Engineering Manual). The toner stored in a low-temperature and low-humidity (10 ° C., 15%) environment was similarly evaluated for penetration, and the value with the lower penetration was employed in a high-temperature and high-humidity and low-temperature and low-humidity environment. From the favorable ones, ◎: 20 mm or more, ◯: 15 mm or more and less than 20 mm, Δ: 10 mm or more to less than 15 mm, x: less than 10 mm.
(3) Development stability Using the obtained two-component developer and an evaluator, an image area ratio 5% chart continuous 10,000 sheet output durability test was conducted, and the change in charge amount at that time was evaluated. 1 g of developer was weighed and the change in charge amount was determined by the blow-off method. Similarly, a continuous 10,000 sheet output durability test with a 50% image area ratio chart was performed, and the change in charge amount at that time was evaluated. 1 g of developer was weighed and the change in charge amount was determined by the blow-off method. The value with the larger charge amount difference between the two is adopted. When the change in charge amount is 5 μc / g / or less, it is judged as ◯, when it is less than 10 μc / g /, Δ when it exceeds 10 μc / g /. did.
(Blow-off method)
The developer was placed in a cylindrical Faraday cage with wire mesh at both ends, and the toner was removed from the developer with high-pressure air, and the amount of charge remaining was measured with an electrometer. The toner weight in the developer was obtained from the difference in weight of the Faraday cage before and after blow-off.

表２から明らかなように、実施例１ないし４では、低温定着性、耐熱保存性、現像安定性のいずれも、実用上の問題は発生しなかった。それに対して、比較例１ないし４では、低温定着性、耐熱保存性、現像安定性のうち、少なくとも１つには実用上の問題が発生した。

As is clear from Table 2, in Examples 1 to 4, no practical problems occurred in any of low-temperature fixability, heat-resistant storage stability, and development stability. On the other hand, in Comparative Examples 1 to 4, practical problems occurred in at least one of low-temperature fixability, heat-resistant storage stability, and development stability.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Process cartridge 3 Image carrier / photosensitive body 4 Reading apparatus 5 Automatic document feeder (ADF)
6 Image forming unit 7 Paper feeding unit 9 Recording member 10 Charging device 11 Charging roller 20 Cleaning device 21 Cleaning blade 22 Waste toner recovery coil 30 Lubricant coating device 31 Brush roller 32 Lubricant 33 Pressure spring 34 Lubricant coating blade 40 Development Device 41 Developing sleeve 42 Restricting member 43, 44 Agitating / conveying screw 50 Transfer device 51 Intermediate transfer belt 52 Primary transfer roller 531, 532, 533, 534 Support roller 54 Secondary transfer roller 55 Intermediate transfer belt cleaning device 56 Conveying belt 60 Supply Paper device 61 Paper feed unit 62 Paper feed roller 63 Transport roller 64 Registration roller 65 Separation roller 68 Manual feed cassette 69 Reversing device 70 Fixing device 71 Fixing roller 72 Pressure roller 80 Exposure device 90 Paper discharge device 91 Paper discharge tray 92 Paper exit 93 Paper delivery roller

JP 2006-267231 A JP2008-180938 JP2007-093637

Claims (12)

A core-shell toner having a core and a shell layer having a thickness of 0.01 μm to 2 μm on the surface of the core,
The core contains at least a binder resin, a colorant, and the shell layer contains at least a crystalline polyester resin as a binder resin;
The softening temperature ST of the shell layer measured by the SPM probe with a built-in heater and the softening temperature CT of the inner core have the following relational expression (1).
1.1 ≦ CT / ST ≦ 2.5 (1)
Toner characterized by the above. The toner according to claim 1.
The toner has a shell layer coated in a layer form after covering the toner surface with resin fine particles containing at least crystalline polyester. The toner according to claim 1 or 2,
The toner, wherein the binder resin of the core of the toner contains at least a polyester resin. The toner according to any one of claims 1 to 3,
A toner characterized in that the toner contains at least a modified polyester resin. In the toner according to any one of claims 1 to 4,
A toner characterized in that the toner is formed by dispersing an oil droplet of an organic solvent in which a toner composition containing a prepolymer is dissolved in an aqueous medium and performing an extension reaction and / or a crosslinking reaction. The toner according to any one of claims 1 to 5,
In the toner, a toner composition containing at least a polymer capable of reacting with a compound having an active hydrogen group, a polyester, a colorant, and a release agent is crosslinked and / or in the presence of resin fine particles in an aqueous medium. A toner characterized by an extension reaction. The toner according to any one of claims 1 to 6,
An average circularity E of the toner is 0.93 to 0.99. The toner according to any one of claims 1 to 7,
The toner has a circularity SF-1 value of 100 to 150 and a circularity SF-2 value of 100 to 140. The toner according to any one of claims 1 to 8,
The toner has a weight average particle diameter D4 of 2 to 7 μm and a ratio D4 / Dn of the weight average particle diameter D4 to the number average particle diameter Dn of 1.25 or less. In a two-component developer used in an image forming apparatus having a magnetic carrier and toner,
The two-component developer, wherein the toner is the toner according to any one of claims 1 to 9. In the process cartridge that integrally supports the image carrier and at least the developing device and is detachable from the image forming apparatus main body,
A process cartridge using the toner according to claim 1 in the developing device. In an image forming apparatus including a fixing device having a fixing medium for fixing a visible image formed with toner on a recording medium by heat and pressure,
The image forming apparatus is a tandem developing system in which at least four or more developing devices of different colors are arranged in series, the system speed is 500 to 2500 mm / sec, and the pressing surface pressure of the fixing medium is 5 N / The image forming apparatus, wherein the image forming apparatus is cm ^{2 to} 90 N / cm ² .

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