JP2010060788A - Toner - Google Patents

Abstract

An object of the present invention is to provide a toner having improved fixability, a uniform material composition between toner particles, and capable of maintaining stable developability even when a large number of sheets are printed out.
A toner having toner particles containing at least a binder resin, a colorant, and a wax component, and an inorganic fine powder, and in a micro compression test for the toner, a restoration rate Z (25) is: average value of the maximum displacement X _3, and, wherein the ratio of the toner present on the average value ± 20% in the value of the X ₃ satisfies the relational expression.
[Selection figure] None

Description

  The present invention relates to a toner used in a recording method such as an electrophotographic method, an electrostatic recording method, a magnetic recording method, and a toner jet method.

  In electrophotography, an electric latent image is formed on a photoreceptor by various means, and then the latent image is developed with toner to form a toner image. The toner image is formed on a recording material (transfer material) such as paper. After the toner is transferred, the toner image is fixed on the recording material by heat and pressure to obtain a print or a copy.

  In recent years, with the development of computers and multimedia, there is a demand for means for outputting further high-definition full-color images in a wide range of fields from offices to homes. Heavy users demand high durability that does not deteriorate image quality even when a large number of copies or prints are made. On the other hand, in small offices and homes, in addition to obtaining high-quality images, it is necessary to reduce the size of the device, reuse waste toner or eliminate waste toner (cleaner-less), and lower the fixing temperature from the viewpoint of saving space and energy. Has been.

  In order to achieve both the durability and fixability of toner particles, it is necessary to discuss the durability and fixability of each toner particle unit, and the hardness (micro compression hardness) of each toner particle unit is an effective index. . The hardness of one toner particle unit (minute compression hardness) indicates the degree of deformation (elasticity / plasticity) of the toner particles. Therefore, in a transfer process in which toner particles can be deformed by applying pressure as in contact transfer, the micro-compression hardness of the toner can be an effective index for transferability in addition to durability and fixability.

  For example, in a capsule toner composed of a heat-meltable core material (core) made of a thermoplastic resin having a low glass transition point and an outer shell (shell) mainly composed of amorphous polyester (core-shell structure), toner 1 It is disclosed that the low temperature fixability, the offset resistance, and the durability can be compatible by defining the relationship between the amount of displacement compressed when a load is applied to the particles and the load within a specific range (Patent Document 1). Patent Document 2). This capsule toner has a structure in which the core material having a low glass transition point is covered with a relatively thick shell layer, so it is effective in the heat and pressure fixing process, but in the light load fixing process, it has a low temperature fixing property and high image gloss. It is difficult to satisfy sex.

  For toner particles, the load-displacement curve of the micro-compression test has an inflection point, and by using a toner whose load at the inflection point is larger than the load received in the developing device, it has excellent durability. It is disclosed that fixing performance is satisfied by simply crushing in the fixing process (Patent Document 3). However, in these toners, the occurrence of filming (fixation) and charging uniformity may be impaired due to the presence of toners having different properties due to unevenness of materials between particles.

  As described above, in order to achieve both durability and fixability, many studies have been made in consideration of the internal structure of the toner particles. However, in the current situation where further high speed and high-definition full-color images are required, There is a need for a toner that maintains fixing properties and sufficiently satisfies high durability and high transferability.

JP-A-6-324526 JP-A-7-301947 JP-A-2005-300937

  An object of the present invention is to provide a toner having improved fixability, a uniform material composition between toner particles, and capable of maintaining stable developability even when a large number of sheets are printed out.

The present invention is a toner having toner particles containing at least a binder resin, a colorant, and a wax component, and an inorganic fine powder,
In the micro-compression test for the toner, a load was applied to the toner particles at a load temperature of 9.8 × 10 ⁻⁵ N / sec at a measurement temperature of 25 ° C., and the maximum load reached 2.94 × 10 ⁻⁴ N. The displacement amount (μm) sometimes obtained is the displacement amount X ₂ , and after reaching the maximum load, the displacement amount (μm) obtained by leaving it at the maximum load for 0.1 second is the maximum displacement amount X ₃ , 0 After leaving for 1 second, the load is reduced at an unloading speed of 9.8 × 10 ⁻⁵ N / sec, and the displacement amount (μm) obtained when the load becomes 0 N is defined as the displacement amount X ₄ , the maximum displacement amount X ₃ and the amount of displacement X ₄ is the elastic displacement amount (X ₃ -X ₄ ), and the percentage of the elastic displacement amount (X ₃ -X ₄ ) with respect to the maximum displacement amount X ₃ [{(X ₃ -X ₄ ) / X _3} × 100: when the recovery ratio] was Z (25) (%), Z (25) is, 40 ≦ Z (25) ≦ 80 of Satisfy the engagement,
The maximum displacement amount X is an average value of ₃ is 0.10 to more than 0.80μm or less, toner (X ₃ existence ratio with the maximum displacement X ₃ within ± 20% on the average value of the maximum displacement X ₃ ) Is present in an amount of 65% to 100% by number.

  According to the present invention, in a micro-compression test for toner, fixing performance is improved by having a specific load-displacement curve, and development is possible even when a large number of printouts are made because variation in the maximum displacement amount is small. A stable image can be provided.

The present invention is a toner having toner particles containing at least a binder resin, a colorant, and a wax component, and an inorganic fine powder,
In the micro-compression test for the toner, a load was applied to the toner particles at a load temperature of 9.8 × 10 ⁻⁵ N / sec at a measurement temperature of 25 ° C., and the maximum load reached 2.94 × 10 ⁻⁴ N. The displacement amount (μm) obtained sometimes is the displacement amount X ₂ , and after the maximum load is applied, the displacement amount (μm) obtained by leaving the maximum load for 0.1 second is the maximum displacement amount X ₃ , After leaving for 0.1 seconds, the load is reduced at an unloading speed of 9.8 × 10 ⁻⁵ N / sec, and the displacement (μm) obtained when the load becomes 0 N is defined as the displacement X ₄ , the maximum displacement. The difference between X ₃ and the displacement amount X ₄ is the elastic displacement amount (X ₃ −X ₄ ), and the percentage of the elastic displacement amount (X ₃ −X ₄ ) with respect to the maximum displacement amount X ₃ [{(X ₃ −X ₄ ) / X ₃ } × 100: Restoration rate] is Z (25) (%), Z (25) is
40 ≦ Z (25) ≦ 80
Satisfied with the relationship
The maximum displacement X ₃ is an average value of 0.10μm or more 0.80μm or less, toner (X ₃ existence ratio with the maximum displacement X ₃ in the maximum displacement amount average value ± 20% in the value of X ₃ ) Is present in the range of 65% to 100% by number.

The X ₃ existence ratio is preferably 70% by number or more and 98% by number or less, and more preferably 75% by number or more and 95% by number or less.

The values of Z (25) and maximum displacement amount X ₃ can satisfy the above relationship by using, for example, the following method, but are not limited thereto.
(1) When the toner particles are produced in an aqueous medium, the toner particles contain a polar resin, which will be described later, to form a shell layer made of the polar resin. Further, the polar resin is selected in consideration of compatibility with the binder resin forming the core layer.
(2) After producing core particles of toner particles in an aqueous medium, a monomer constituting a polar resin is added and seed polymerization is performed to form a shell layer.
(3) Polar resin fine particles having a volume average particle size smaller than that of the core particles are mechanically attached to the core particles. Alternatively, polar resin fine particles having a small volume average particle diameter are attached to the core particles by aggregation in an aqueous medium and fixed by heating.

  By the above-described method, the toner particles have a core-shell structure, so that a shell layer having an optimum hardness can be provided, and durability is improved. In addition, the core layer can be designed to be sufficiently soft by having a shell layer having an optimum hardness, and the fixing property at low temperature is also improved.

In addition, since the X ₃ abundance satisfies the above relationship, since there is little deviation in the material composition between the particles, toner particles having uniform properties can be obtained, and durability is improved.

In the micro-compression test for the toner in the present invention, the evaluation is performed by applying a small load to one toner particle in comparison with the conventional measurement method having a maximum load of 2.94 × 10 ⁻⁴ N. It measures the hardness, the recovery rate, and the inter-particle uniformity of the toner material.

  In other words, in the toner of the present invention, the value of Z (25) is an index indicating how much the toner surface layer returns to the original state when unloaded after applying the maximum load at a measurement temperature of 25 ° C. is there. When the value of Z (25) is less than 40, the toner is likely to be deformed by the stress received in the developing device, and the developability and transferability are likely to be lowered. Further, the vicinity of the toner surface layer becomes too soft at the time of fixing, so that the toner easily moves to the surface of the fixing roller, and the high-temperature offset resistance tends to decrease. On the other hand, if the value of Z (25) exceeds 80, the vicinity of the toner surface layer becomes difficult to deform, so that the bleedability of the wax is lowered in the fixing process, and offset on the low temperature side is likely to occur, and low temperature fixability is reduced. It is unsuitable. Also, since the toner particle surface is difficult to deform, it is difficult for the external additive to adhere to the toner particle surface, and when a large number of sheets are printed out, the external additive on the toner surface is easily released, and developability and transferability are improved. There is a tendency to decrease.

On the other hand, in the toner of the present invention, the value of the X ₃ abundance is a value within ± 20% of the total displacement of the particles when the maximum load is applied at a measurement temperature of 25 ° C. Is an index representing the uniformity of material composition among particles. That is, the toner having the maximum amount of displacement within the average value X20 of X ₃ is uniform in the ratio of various materials constituting the toner particles, so that the thickness of the shell layer and the hardness of the core layer are the same. And the difference in properties between particles becomes small. In addition, since the presence state of the colorant and the charge control agent tends to be uniform from the presence state of the polar resin near the surface from the toner surface, the charging property is also uniform.

By increasing the ratio of toner particles with the same material composition and the same properties, contamination of the members due to the adhesion of toner particles with different properties can be suppressed, and the charging uniformity after printing out a large number of sheets can be maintained. And developability can be maintained. In the toner of the present invention, when the X ₃ abundance ratio is less than 65%, since the material composition is not uniform among the toner particles, there are many toner particles having different properties, and the toner is easily fused to the toner carrier or the regulating member. Therefore, developability tends to decrease. Further, the charging uniformity is lowered, and the developability and transferability after printing out a large number of sheets tend to be lowered.

In order to further improve the durability, the X ₃ abundance is preferably 70% by number to 98% by number, and more preferably 75% by number to 95% by number. When the X ₃ abundance ratio exceeds 95% by number, there is no practical problem, but it becomes easy to selectively develop a toner having a uniform composition, the charging uniformity after printing a large number of sheets decreases, and the developability deteriorates. Tend.

The X ₃ abundance can be controlled, for example, by adjusting the mixing state of the colorant and the resin-containing monomer in the suspension polymerization toner.

Furthermore, in order to achieve both durability and fixability, the toner of the present invention requires that the average value of X ₃ is 0.10 μm or more and 0.80 μm or less.

The average value of X ₃ is the surface layer of the toner near becomes hard is less than 0.10 .mu.m, bleeding of the wax is lowered in the fixing step, it is not suitable for low-temperature fixability becomes offset the low temperature side is likely to occur. Also, since the toner particle surface is difficult to deform, it is difficult for the external additive to adhere to the toner particle surface, and when a large number of sheets are printed out, the external additive on the toner surface is easily released, and developability and transferability are improved. There is a tendency to decrease. On the other hand, when the average value of X ₃ exceeds 0.80 μm, the vicinity of the toner surface layer becomes too soft at the time of fixing, and the toner easily moves to the surface of the fixing roller, and the high-temperature offset resistance tends to be lowered.

The Z (25) and the maximum displacement amount X ₃ are, for example, in the suspension polymerization method, the glass transition temperature and the weight average molecular weight of the polar resin that forms the surface layer and the binder resin of the toner, or the polar resin and the crosslinking agent. It is possible to satisfy the above range by adjusting the amount of addition and the like.

Further, in the micro-compression test, in the load-displacement curve in which the load and the amount of displacement are plotted at the measurement temperature of 25 ° C., the slope of the load-displacement curve from the origin to the maximum load is represented by R (25) [2 .94 × 10 ⁻⁴ / displacement amount X ₂ (N / μm)], the value of R (25) is an index representing the hardness in the vicinity of the toner surface layer at a temperature of 25 ° C. When the value of R (25) is less than 0.49 × 10 ⁻³ N / μm, the toner is liable to be crushed by the stress received in the developing device, and deformed and easily developable and transferable.

On the other hand, if the value of R (25) exceeds 1.70 × 10 ⁻³ N / μm, the vicinity of the toner surface layer becomes hard and brittle, so the toner may be deformed by a slight load. As a result, the low-temperature fixability tends to decrease.

The toner of the present invention is subjected to a maximum load of 2.94 × 10 ⁻⁴ N at a load speed of 9.8 × 10 ⁻⁵ N / sec at a measurement temperature of 50 ° C. in the minute compression test. The displacement amount (μm) obtained at the end is the displacement amount X ′ ₂ , and after the maximum load is applied, the displacement amount (μm) obtained by leaving at the maximum load for 0.1 second is the maximum displacement amount X ′. _3. After leaving for 0.1 seconds, unload at the unloading speed of 9.8 × 10 ⁻⁵ N / sec. The displacement (μm) obtained when the load becomes 0 is the displacement X ′ ₄ , the maximum the difference between 'and ₃ the displacement X' displacement X ₄ and the elastic displacement (X _'3 -X' _4), a percentage of the maximum displacement amount X _'3 of the elastic displacement (X' ₃ -X _'4) When [(X ′ ₃ −X ′ ₄ ) / X ′ ₃ × 100: Restoration rate] is Z (50) (%), the relationship that Z (50) is 10 ≦ Z (50) ≦ 55 Can be satisfied Masui. By satisfying this relationship, the toner can exhibit high bleedability even with instantaneous heat in the fixing step, and the low-temperature fixability can be further improved. Moreover, it is more preferable that the Z (50) satisfies the relationship of 15 ≦ Z (50) ≦ 35.

Furthermore, in order to achieve both durability and fixability, in the toner of the present invention, X ′ ₂ is preferably 0.02 μm or more and 0.60 μm or less, and X ′ ₃ is preferably 0.05 μm or more and 0.70 μm or less. .

  For example, in the suspension polymerization method, the above R (25) and Z (50) can be obtained by adjusting the glass transition temperature, the weight average molecular weight of the polar resin or the binder resin of the toner, or the addition of a crosslinking agent. It is possible to satisfy the range.

  Next, a measurement method of the micro compression test will be described with reference to FIG.

  FIG. 1 is a profile (load-displacement curve) when the toner of the present invention is measured in a micro-compression test. The horizontal axis represents the amount of displacement of the toner and the vertical axis represents the amount of load applied to the toner.

For the micro compression test in the present invention, an ultra micro hardness tester ENT1100 manufactured by Elionix Co., Ltd. was used. The working indenter was measured using a 20 μm × 20 μm square flat indenter. 1-1 in the figure is an initial state (origin) before starting the test, and the load is applied at a load speed of 9.8 × 10 ⁻⁵ N / sec with respect to the maximum load of 2.94 × 10 ⁻⁴ N. Multiply. Immediately after reaching the maximum load, the state is 1-2, and the displacement amount at this time is X ₂ (μm). Leave it under that load for 0.1 second in the state of 1-2. The state immediately after the end of standing is 1-3, and the maximum displacement at this time is X ₃ (μm), and further, the load is applied at the unloading speed of 9.8 × 10 ⁻⁵ N / sec through the maximum load. When the load decreases to 0N, the state is 1-4. The amount of displacement at this time is X ₄ (μm).

Z (25) indicating the percentage of the elastic displacement amount (X ₃ -X ₄ ) with respect to the maximum displacement amount X ₃ (hereinafter also referred to as the restoration rate (%)) is {(X ₃ -X ₄ ) / X ₃ } × 100 As sought. [Load-displacement curve slope] R (25) from the origin to the maximum load approximates the load-displacement curve from 1-1 to 1-2 as a linear line, and the slope of the straight line is (2 .94 × 10 ⁻⁴ ) / X ₂ (N / μm). Furthermore, the value of Z (50) is the maximum displacement amount X ′ ₃ obtained in the same manner as the measurement method of Z (25), except that it is measured at a measurement temperature of 50 ° C. in a minute compression test for toner. is a value obtained from the displacement X _'4.

  The actual measurement is performed by applying toner on the ceramic cell, blowing air so that the toner is dispersed on the ceramic cell, and then setting the ceramic cell on an ultra-micro hardness meter.

  In the measurement, the ceramic cell was brought into a temperature-controllable state, and the temperature of the ceramic cell was taken as the measurement temperature. That is, R (25) and Z (25) were measured at a cell temperature of 25 ° C., and R (50) was measured at a cell temperature of 50 ° C. The temperature of the ceramic cell was adjusted by placing the ceramic cell in an ultra-micro hardness tester and allowing it to stand for 10 minutes or more after the ceramic cell reached the measurement temperature.

  For the measurement, while looking through a microscope attached to the ultra-micro hardness meter, a toner having one toner particle on the measurement screen (horizontal width: 160 μm, vertical width: 120 μm) was selected. In order to eliminate the error of the displacement amount as much as possible, a toner having a number average particle diameter D1 of ± 0.20 μm was selected and measured. An arbitrary toner is selected from the measurement screen, but the toner particle diameter measuring means on the measurement screen measures the major and minor diameters of the toner particles using the software attached to the microhardness meter ENT1100, A toner having an aspect ratio [(major axis + minor axis) / 2] calculated from them having a D1 of ± 0.20 μm was selected and measured.

Regarding the measurement data, 100 arbitrary particles were selected and measured, and the average value of Z (25), Z (50) and R (25) obtained as a measurement result was obtained. Moreover, the proportion of particles having a maximum displacement X ₃ in the maximum displacement amount average value ± 20% in the value of X ₃ was X ₃ existence ratio.

  The weight average particle diameter (D4) and number average particle diameter (D1) of the toner are calculated as follows. As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used. For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) is used. Note that the measurement is performed with 25,000 effective measurement channels.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, the dedicated software was set as follows.

  On the “Change Standard Measurement Method (SOM)” screen of the dedicated software, set the total count in the control mode to 50,000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the “aperture tube flush after measurement” is checked.

  In the “Pulse to particle size conversion setting” screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.

  The specific measurement method is as follows.

  (1) About 200 ml of the electrolytic aqueous solution is put in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rotations / second. Then, the dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.

  (2) About 30 ml of the electrolytic aqueous solution is put into a glass 100 ml flat bottom beaker. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water is added.

  (3) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikki Bios Co., Ltd.) having an electrical output of 120 W is prepared. About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminone N is added to the water tank.

  (4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.

  (5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.

  (6) To the round bottom beaker of (1) installed in the sample stand, the electrolyte solution of (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to about 5%. . The measurement is performed until the number of measured particles reaches 50,000.

  (7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) and the number average particle diameter (D1) are calculated. The “average diameter” on the “analysis / volume statistics (arithmetic average)” screen when the graph / volume% is set in the dedicated software is the weight average particle size (D4). When the number% is set, the “average diameter” on the “analysis / number statistics (arithmetic average)” screen is the number average particle diameter (D1).

  The method for producing the toner particles used in the present invention is not particularly limited, and the toner particles can be produced by a conventional toner production method. In other words, it can be prepared by a manufacturing method in which the toner is granulated in an aqueous medium, such as a pulverization method in which the toner is prepared through kneading, pulverization, and classification steps, a suspension polymerization method, an emulsion polymerization method, and a suspension granulation method It is.

  Among these, the suspension polymerization method is particularly preferable as the one that easily exhibits the effects of the present invention. In this suspension polymerization method, a polymerizable monomer is uniformly dissolved or dispersed with a wax and a colorant (and a polymerization initiator, a crosslinking agent, a charge control agent, and other additives as necessary) to achieve polymerization. A monomer composition is used. Thereafter, the polymerizable monomer composition is dispersed in an aqueous medium containing a dispersant using an appropriate stirrer, and a polymerization reaction is performed to obtain toner particles having a desired particle size. . The polymerization initiator may be added simultaneously with the addition of other additives to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. Also, a polymerization initiator dissolved in a polymerizable monomer or solvent can be added immediately after granulation and before starting the polymerization reaction. After the polymerization, the toner particles are filtered, washed and dried by a known method, and if necessary, a fluidity improver is mixed and adhered to the surface to obtain the toner of the present invention.

  Moreover, it is a preferable embodiment of the present invention that the polymerizable monomer composition is obtained by mixing with an ultrasonic oscillator. In particular, a dispersion step in which at least a colorant is dispersed in a polymerizable monomer to obtain a colorant-containing monomer, a dissolution step in which at least a resin is dissolved in the polymerizable monomer to obtain a resin-containing monomer, and the obtained colorant A toner having at least a preparation step of mixing a containing monomer and a resin-containing monomer to obtain an adjustment liquid, and a granulating step of dispersing the adjustment liquid in an aqueous dispersion to produce particles of a polymerizable monomer composition A toner obtained by a method for producing particles, wherein the adjustment step is performed using an ultrasonic oscillation device to mix the colorant-containing monomer and the resin-containing monomer to obtain an adjustment liquid Toner particles obtained by a production method characterized by the above are preferable.

  In particular, the polymerizable monomer composition is obtained by mixing a colorant-containing monomer in which at least a colorant is dispersed in a polymerizable monomer and a resin-containing monomer in which at least a resin is dissolved in the polymerizable monomer. When the mixing is performed using an ultrasonic oscillating device, the pigment shock of the colorant in the step of obtaining the polymerizable monomer composition is suppressed, and a polar resin or Various materials can be mixed uniformly, and further, the colorant can be dispersed in a fine and uniform state. Then, by carrying out the polymerization reaction using the polymerizable monomer composition thus obtained, it becomes uniform from the presence state of the polar resin near the surface of the toner to the presence state of the colorant in the internal structure. Cheap. For this reason, the durability of the toner of the present invention is improved and the contamination of the members is less likely to occur, and the charging property is likely to be uniform.

  An example of the shape of the ultrasonic oscillator used in the present invention is shown in FIGS. The shape preferably used in the present invention is such that the ultrasonic irradiation portion as shown in FIG. 2 has a vibrator for irradiating ultrasonic waves having convex portions in the circumferential direction of the cylinder, and the convex portions are It is more preferable to have a shape that is a convex part that forms a concentric circle with respect to the cylinder.

  This structure has multiple ultrasonic irradiation parts, and the frequency of ultrasonic treatment increases accordingly, so the dispersion and dissolution unevenness of the processed material is very small, uniform and predetermined dispersion in a short time compared to the conventional Can reach the state.

In the step of obtaining the polymerizable monomer composition, the output per ultrasonic generator is A (W), and the ultrasonic irradiation area per ultrasonic generator is B (cm ² ). It is preferable that A ≧ 1700 and A / B is in the range of 9 ≦ A / B ≦ 65. If A is less than 1700, the scale is too small as a mass production machine, which is not preferable. And when A / B is less than 9, the acceleration of the ultrasonic wave is small and the dispersion / mixing efficiency is poor, and when it exceeds 65, the wear of the ultrasonic irradiation part is large, leading to a colorant-containing polymerizable monomer composition. This is not preferable because the contamination of the device and the consumption of the device itself are severe.

  When the colorant-containing polymerizable monomer composition to be ultrasonically treated in the step of obtaining the polymerizable monomer composition is C (kg) and the total output of the ultrasonic generator is D (kW), 20 ≦ C / D ≦ 165 is preferable. In a region where C / D exceeds 165, the irradiation energy is too small, and it is difficult to achieve a desired dispersion / mixing level. On the other hand, if it is less than 20, the dispersion state tends to be saturated and becomes excessive energy, which is not preferable for energy saving.

  The materials used in the present invention will be described below.

  Examples of the binder resin used in the present invention include styrene-acrylic copolymers, styrene-methacrylic copolymers, epoxy resins, and styrene-butadiene copolymers. Examples of the polymerizable monomer used in the production of the binder resin include vinyl polymerizable monomers capable of radical polymerization. As the vinyl polymerizable monomer, a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used.

  Examples of the polymerizable monomer include the following.

  Styrene; Styrenic monomers such as o- (m-, p-) methylstyrene, m- (p-) ethylstyrene; methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, Propyl methacrylate, butyl acrylate, butyl methacrylate, octyl acrylate, octyl methacrylate, dodecyl acrylate, dodecyl methacrylate, stearyl acrylate, stearyl methacrylate, behenyl acrylate, behenyl methacrylate, 2-ethylhexyl acrylate, Acrylic acid ester monomers such as 2-ethylhexyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate and diethylaminoethyl methacrylate, Ether-based monomers; butadiene, isoprene, cyclohexene, acrylonitrile, methacrylonitrile, acrylic acid amide, such as ene-based monomers methacrylamide.

  These may be used alone or in general by appropriately mixing monomers with reference to the theoretical glass transition temperature (Tg) described in the publication Polymer Handbook 2nd edition III-p139 to 192 (manufactured by John Wiley & Sons). Used.

  In the toner of the present invention, it is also preferable that the toner particles contain a polar resin. Furthermore, it is preferable that the glass transition temperature (Tg) measured with the differential scanning calorimetry (DSC) apparatus of the said polar resin is 80 degreeC or more and 120 degrees C or less. By setting Tg within this range, it is possible to further enhance both the durability and low-temperature fixability of the toner. In the toner of the present invention, when Tg is less than 80 ° C., the durability of the toner tends to decrease, and when Tg exceeds 120 ° C., low-temperature fixability tends to decrease.

  The above Tg was measured using a differential scanning calorimeter (DSC measuring device) Q1000 (manufactured by TA Instruments Japan) according to ASTM D3418-82 under the following method and conditions.

<Measurement conditions and method>
(1) Use modulated mode.
(2) Keep the equilibrium at a temperature of 20 ° C. for 5 minutes.
(3) Using a modulation of 1.0 ° C / min, the temperature is increased to 140 ° C at 1 ° C / min.
(4) Keep the equilibrium at a temperature of 140 ° C. for 5 minutes.
(5) The temperature is lowered to 20 ° C.

  About 3 mg of the measurement sample is accurately weighed. It is put in an aluminum pan, and an empty aluminum pan is used as a control, and measurement is performed at a temperature rising rate of 1 ° C./min between a measurement range of 20 to 140 ° C. The glass transition temperature (Tg) here is determined by the midpoint method.

  When the toner particles used in the present invention are produced by a suspension polymerization method, it is preferable to add a polar resin to the adjustment step. In that case, the presence state of the polar resin can be controlled according to the balance of polarity exhibited by the polymerizable monomer composition serving as toner particles and the aqueous dispersion medium. That is, the added polar resin can form a thin shell on the surface of the toner particles, or can exist with a gradient toward the center from the toner particle surface. In addition, the strength of the shell portion of the core-shell structure can be freely controlled by adding the polar resin. Therefore, it is possible to optimize the durability and fixability of the toner.

  The addition amount of the polar resin is preferably 1 part by mass or more and 30 parts by mass or less, more preferably 15 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the binder resin. If the amount is less than 1 part by mass, the presence state of the polar resin in the toner particles tends to be uneven, and the triboelectric charge distribution of the toner tends to be broad. On the other hand, when the amount exceeds 30 parts by mass, the thin layer of polar resin formed on the surface of the toner particles becomes thick and the fixability tends to be lowered.

  Specific examples of the polar resin used in the present invention include polyester resins, epoxy resins, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, and styrene-maleic acid copolymers. In particular, a styrene-methacrylic acid copolymer or a styrene-acrylic acid copolymer having a peak molecular weight of 3,000 or more and 50,000 or less is preferable as a polar resin because the addition amount during toner production can be freely controlled. Further, when a styrene-methacrylic acid copolymer or a styrene-acrylic copolymer is used as the polar resin, it is preferable because the compatibility of the toner with the binder resin is further improved. As a result, the toner particles tend to exist from the surface to the center with an inclination, and the adhesion between the core layer and the shell layer is increased, and the durability of the toner is improved.

  As described above, as a preferable aspect of the toner of the present invention, the toner particle has a core-shell structure, the adhesion between the core layer and the shell layer is increased, and the toner is pressed at room temperature. The toughness against external factors at the time is great, and the core component (especially wax) has bleeding properties when the toner is heated. These characteristics of the toner particles are thought to contribute to development characteristics, transfer characteristics, and fixing characteristics.

  The following are mentioned as a wax component used for this invention.

  Petroleum waxes and derivatives thereof such as paraffin wax, microcrystalline wax, petrolactam; montan wax and derivatives thereof; hydrocarbon waxes and derivatives thereof according to the Fischer-Tropsch method; polyolefin waxes and derivatives thereof such as polyethylene wax and polypropylene wax; Natural waxes such as wax and candelilla wax and derivatives thereof; higher aliphatic alcohols; fatty acids such as stearic acid and palmitic acid; acid amide waxes; ester waxes; hardened castor oil and derivatives thereof; plant waxes;

  Among these, ester wax and hydrocarbon wax are preferable from the viewpoint of excellent releasability. More preferably, a compound containing 50 to 95% by mass of a compound having the same total number of carbon atoms has high wax purity and easily develops the effects of the present invention from the viewpoint of developability.

  In the present invention, in order to increase the mechanical strength of the toner particles and to control the molecular weight of the toner binder resin, a crosslinking agent may be used when the binder resin is synthesized.

  As the crosslinking agent, a compound having two or more polymerizable double bonds is mainly used. The following aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate; divinylaniline And divinyl compounds such as divinyl ether, divinyl sulfide and divinyl sulfone; and compounds having three or more vinyl groups. These can be used alone or as a mixture. A preferable addition amount is 0.001 to 15% by mass with respect to 100 parts by mass of the binder resin.

  The following are mentioned as a polymerization initiator used for this invention.

  2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis Azo or diazo polymerization initiators such as -4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl Peroxide-based polymerization initiators such as peroxide, lauroyl peroxide, tert-butyl-peroxypivalate.

  Although the usage-amount of these polymerization initiators changes with the target degree of polymerization, generally they are 3 mass parts or more and 20 mass parts or less with respect to 100 mass parts of said polymerizable monomers. The kind of the polymerization initiator is slightly different depending on the polymerization method, but is selected with reference to the 10-hour half-life temperature and used alone or in combination.

  Examples of the colorant preferably used in the present invention include the following organic pigments or dyes and inorganic pigments.

  As the organic pigment or organic dye as the cyan colorant, a copper phthalocyanine compound and a derivative thereof, an anthraquinone compound, or a basic dye lake compound can be used.

  Specifically, the following are mentioned. C. I. Pigment blue 1, C.I. I. Pigment blue 7, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 1, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment blue 60, C.I. I. Pigment blue 62, C.I. I. Pigment Blue 66.

  Examples of the organic pigment or organic dye as the magenta colorant include the following. Condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds.

  Specifically, the following are mentioned. C. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment violet 19, C.I. I. Pigment red 23, C.I. I. Pigment red 48: 2, C.I. I. Pigment red 48: 3, C.I. I. Pigment red 48: 4, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 81: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 144, C.I. I. Pigment red 146, C.I. I. Pigment red 150, C.I. I. Pigment red 166, C.I. I. Pigment red 169, C.I. I. Pigment red 177, C.I. I. Pigment red 184, C.I. I. Pigment red 185, C.I. I. Pigment red 202, C.I. I. Pigment red 206, C.I. I. Pigment red 220, C.I. I. Pigment red 221, C.I. I. Pigment Red 254.

  As the organic pigment or organic dye as the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used.

  Specifically, the following are mentioned. C. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 62, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 83, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 95, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 109, C.I. I. Pigment yellow 110, C.I. I. Pigment yellow 111, C.I. I. Pigment yellow 120, C.I. I. Pigment yellow 127, C.I. I. Pigment yellow 128, C.I. I. Pigment yellow 129, C.I. I. Pigment yellow 147, C.I. I. Pigment yellow 151, C.I. I. Pigment yellow 154, C.I. I. Pigment yellow 155, C.I. I. Pigment yellow 168, C.I. I. Pigment yellow 174, C.I. I. Pigment yellow 175, C.I. I. Pigment yellow 176, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 181, C.I. I. Pigment yellow 191, C.I. I. Pigment Yellow 194.

  As the black colorant, carbon black and those which are toned in black using the yellow / magenta / cyan colorants are used.

  These colorants can be used alone or in combination and further in the form of a solid solution. The colorant used in the toner of the present invention is selected from the viewpoints of hue angle, saturation, brightness, light resistance, OHP transparency, and dispersibility in the toner.

  The colorant is preferably used in an amount of 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin.

  In the present invention, when a toner is obtained using a polymerization method, it is necessary to pay attention to the polymerization inhibitory property and water phase transfer property of the colorant. Therefore, it is preferable that the colorant be subjected to surface modification, for example, a hydrophobic treatment with a substance that does not inhibit polymerization. In particular, dyes and carbon blacks have many polymerization inhibiting properties, so care must be taken when using them.

  Examples of a method for suppressing the polymerization inhibitory property of the dye-based colorant include a method in which a polymerizable monomer is polymerized in the presence of these dyes in advance, and the obtained colored polymer is used as a polymerizable monomer composition. Added.

  Carbon black may be treated with a material that reacts with the surface functional group of carbon black, for example, polyorganosiloxane, in addition to the same treatment as the above dye.

  In the present invention, it is preferable to use a polymer having a sulfonic acid group in the side chain mainly for charge control and stabilization of granulation in an aqueous medium. Among them, it is particularly preferable to use a polymer or copolymer containing a sulfonic acid group, a sulfonic acid group, or a sulfonic acid ester group.

  Examples of the monomer having a sulfonic acid group for producing the polymer include styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, 2-methacrylamide-2-methylpropane sulfonic acid, vinyl sulfonic acid, methacrylic acid. A sulfonic acid can be illustrated.

  The polymer containing a sulfonic acid group and the like used in the present invention may be a homopolymer of the above monomer, but is a copolymer of the above monomer and another monomer. It doesn't matter. As a monomer that forms a copolymer with the above monomer, there is a vinyl polymerizable monomer, and a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used.

  Monofunctional polymerizable monomers include the following styrene: α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn -Butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene Styrene-based polymerizable monomers such as p-phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate , N-hexyl acrylate, 2-ethylhexyl Acrylic polymerizable monomers such as polyacrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate Mer: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n -Octyl methacrylate, n-nonyl methacrylate, diethyl phosphate Methacrylic polymerizable monomers such as til methacrylate and dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid ester; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate and vinyl formate; vinyl methyl ether And vinyl ethers such as vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

  The following polyfunctional polymerizable monomers include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, Propylene glycol diacrylate, polypropylene glycol diacrylate, 2,2'-bis (4- (acryloxy-diethoxy) phenyl) propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, tri Ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol Coal dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis (4- (methacryloxy-diethoxy) phenyl) propane 2,2′-bis (4-methacryloxy-polyethoxy) phenyl) propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, divinyl ether and the like.

  The polymer having a sulfonic acid group or the like preferably contains 0.01 to 5.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer or binder resin. More preferably, it is 0.1 to 3.0 parts by mass.

  In the toner of the present invention, a charge control agent can be mixed with toner particles as necessary. By adding a charge control agent, the charge characteristics can be stabilized, and the optimum triboelectric charge amount can be controlled according to the development system.

  As the charge control agent, known ones can be used, and in particular, a charge control agent that has a high frictional charging speed and can stably maintain a constant triboelectric charge amount is preferable. Further, when the toner is produced by a direct polymerization method, a charge control agent having a low polymerization inhibitory property and substantially free from a solubilized product in an aqueous dispersion medium is particularly preferable.

  Examples of the charge control agent that control the toner to be negatively charged include organometallic compounds and chelate compounds. Examples thereof include monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids, and dicarboxylic acid-based metal compounds. Others include aromatic oxycarboxylic acids, aromatic mono and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenols. Further examples include urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarene, and resin charge control agents.

  On the other hand, examples of the charge control agent that control the toner to be positively charged include the following. Nigrosine modified products with nigrosine and fatty acid metal salts; guanidine compounds; imidazole compounds; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like Some onium salts such as phosphonium salts and lake pigments thereof; triphenylmethane dyes and lake pigments thereof. , Ferricyanides, ferrocyanides); metal salts of higher fatty acids; resin-based charge control agents.

  The toner of the present invention can contain these charge control agents alone or in combination of two or more.

  Among these charge control agents, a salicylic acid-based compound containing a metal is preferable in order to sufficiently exhibit the effects of the present invention, and the metal is particularly preferably aluminum or zirconium. The most preferred charge control agent is an aluminum 3,5-di-tert-butylsalicylate compound.

  A preferable blending amount of the charge control agent is 0.01 parts by mass or more and 20 parts by mass or less, more preferably 0.5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin. However, it is not essential to add a charge control agent to the toner of the present invention, and the toner does not necessarily contain a charge control agent by actively utilizing frictional charging with the toner layer thickness regulating member or the toner carrier. There is no need to let it.

  In the above production method by suspension polymerization, known inorganic and organic dispersants can be used as the dispersant.

  Specifically, examples of the inorganic dispersant include the following. Tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, magnesium carbonate, calcium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina .

  On the other hand, examples of the organic dispersant include the following. Polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, carboxymethyl cellulose sodium salt, starch.

  Further, commercially available nonionic, anionic and cationic surfactants can be used as the dispersant. Examples of such surfactants include the following. Sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate.

  As the dispersant, an inorganic poorly water-soluble dispersant is preferable, and it is preferable to use a poorly water-soluble inorganic dispersant that is soluble in an acid.

  In the present invention, when preparing a water-based dispersion medium using a hardly water-soluble inorganic dispersant, the amount of these dispersants used is 0.2 mass relative to 100 parts by mass of the polymerizable monomer. It is preferable that it is at least 2.0 parts by mass. In the present invention, it is preferable to prepare an aqueous dispersion medium using 300 to 3,000 parts by mass of water with respect to 100 parts by mass of the polymerizable monomer composition.

  In the present invention, when preparing an aqueous dispersion medium in which the poorly water-soluble inorganic dispersant as described above is dispersed, a commercially available dispersant may be used as it is. In order to obtain dispersant particles having a fine and uniform particle size, an aqueous dispersion medium may be prepared by generating the sparingly water-soluble inorganic dispersant in a liquid medium such as water under high-speed stirring. For example, when tricalcium phosphate is used as a dispersant, it is possible to form a tricalcium phosphate microparticle by mixing a sodium phosphate aqueous solution and a calcium chloride aqueous solution under high-speed stirring.

  In the toner of the present invention, inorganic fine powder is externally added as a fluidizing agent.

  The inorganic fine powder externally added to the toner particles of the present invention preferably contains at least silica fine powder. The number average primary particle size of the silica fine powder is preferably 4 nm or more and 80 nm or less. In the present invention, when the number average primary particle size is in the above range, the fluidity of the toner is improved and the storage stability of the toner is also improved.

  The number average primary particle size of the inorganic fine powder is measured as follows.

  The number average primary particle size is observed with a scanning electron microscope, and the particle size of 100 inorganic fine powders in the visual field is measured to determine the average particle size.

  As the inorganic fine powder, silica fine powder and fine powder of titanium oxide, alumina or their double oxide can be used in combination. As the inorganic fine powder used in combination, titanium oxide is preferable.

The silica fine powder includes both dry silica produced by vapor phase oxidation of silicon halide or dry silica called fumed silica, and wet silica produced from water glass. As the silica, dry silica is preferable because it has few silanol groups on the surface and inside of the silica, and few Na ₂ O and SO ₃ ^2- production residues. In addition, dry silica can also be used to produce composite fine powders of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the production process. Silica also includes them.

  The inorganic fine powder is added for improving the fluidity of the toner and making the frictional electrification of the toner particles uniform. Hydrophobic treatment of inorganic fine powder can provide functions such as adjustment of triboelectric charge amount of toner, improvement of environmental stability, improvement of characteristics under high humidity environment, etc. It is preferable to use inorganic fine powder. When the inorganic fine powder externally added to the toner particles absorbs moisture, the amount of triboelectric charge as the toner decreases, and the developability and transferability tend to decrease.

  Examples of the treatment agent for the hydrophobic treatment of the inorganic fine powder include the following.

  Unmodified silicone varnish, various modified silicone varnishes, unmodified silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organosilicon compounds, and organotitanium compounds. These treatment agents may be used alone or in combination.

  Among these, inorganic fine powder treated with silicone oil is preferable. More preferably, the inorganic fine powder is hydrophobized with a coupling agent at the same time or after the treatment, and the hydrophobized inorganic fine powder treated with silicone oil maintains a high triboelectric charge amount of the toner particles even in a high humidity environment. It is good for reducing selective developability.

  Next, an image forming method used in the present invention will be described with reference to FIGS.

  FIG. 4 shows the configuration of the image forming apparatus including the image forming method used in the present embodiment. The image forming apparatus shown in FIG. 4 is a laser beam printer using a transfer type electrophotographic process. In particular, FIG. 4 shows a cross-sectional view of a tandem color LBP (color laser printer).

<Process cartridge>
FIG. 4 is a schematic cross-sectional view of a process cartridge 7 (hereinafter also referred to as “cartridge”) that can be suitably used in an image forming apparatus to which the image forming method of the present invention is applied.

  The cartridge 7 includes a photosensitive drum 1, a cleaner unit 50 having a charging unit 2 and a cleaning unit 6, and a developing unit 4 </ b> A having a developing unit 4 that develops an electrostatic latent image formed on the photosensitive drum 1. Have. The photosensitive drum 1 is rotatably attached to the cleaning frame 31 constituting the cleaner unit 50 via a bearing member (not shown).

  The photosensitive drum 1 has a charging roller 2 for uniformly charging the photosensitive layer provided on the outer peripheral surface of the photosensitive drum 1, and a developer (residual toner) remaining on the photosensitive drum 1 after transfer is removed. The cleaning blade 60 for making contact is in contact. The toner (removed toner) removed from the surface of the photosensitive drum 1 by the cleaning blade 60 is stored in a removed toner storage chamber 35 provided in the cleaning frame 31.

  The developing unit 4A has a developing frame body 45 (45a, 45b, 45e) that accommodates toner, and the developing roller 40 (rotated in the direction of arrow Y) is rotatably attached to the developing frame body 45 via a bearing member. It is supported. Further, a toner supply roller 43 (rotated in the arrow Z direction) and a toner regulating member 44 are provided in contact with the developing roller 40. Further, the developing frame body 45 is provided with a toner transport mechanism 42 for stirring the toner contained therein and transporting the toner to the toner supply roller 43.

  The developing unit 4A is supported so as to be swingable with respect to the cleaner unit 50. That is, the coupling holes 47 and 48 provided at both ends of the developing device frame 45 are aligned with the support holes (not shown) provided at both ends of the cleaning frame 31 of the cleaner unit 50, and pins (not shown) are inserted from both ends of the cleaner unit 50. It is out.

  Further, the developing unit 4A is always urged by a pressure spring (not shown) so that the developing roller 40 contacts the photosensitive drum 1 with the support hole as the rotation axis.

  At the time of development, the toner stored in the toner container 41 is conveyed to the toner supply roller 43 by the toner stirring mechanism 42. The toner supply roller 43 supplies toner to the developing roller 40 by rubbing with the developing roller 40, and causes the toner to adhere on the developing roller 40. The toner adhered on the developing roller 40 reaches the toner regulating member 44 as the developing roller 40 rotates. Then, the toner regulating member 44 regulates the toner to form a predetermined toner thin layer, and gives a desired charge amount. The toner thinned on the developing roller 40 is conveyed to the developing unit in which the photosensitive drum 1 and the developing roller 40 come close as the developing roller 40 rotates. Then, in the developing unit, the latent image is developed by attaching to the electrostatic latent image formed on the surface of the photosensitive drum 1 by a developing bias applied to the developing roller 40 from a power source (not shown). The toner remaining on the surface of the developing roller 40 without contributing to the development of the electrostatic latent image is returned into the developing frame 45 as the developing roller 40 rotates. Then, it is peeled off and collected from the developing roller 40 at the rubbing portion with the toner supply roller 43. The collected toner is stirred and mixed with the remaining toner by the toner stirring mechanism 42.

  Here, an elastic roller is used as the developing roller 40, and a method of bringing the roller into contact with the surface of the photosensitive drum 1 can be used. In general, in a developing method in which a toner carrier and a photoreceptor are in contact with each other, toner is easily damaged or deformed. However, when the toner described in the present invention is used, such a change can be effectively suppressed. preferable.

In the developing method in which the toner carrying member and the photosensitive member are in contact with each other, development is performed by an electric field acting between the photosensitive member and the elastic roller facing the surface of the photosensitive member through the toner. Therefore, the surface of the elastic roller or the vicinity of the surface has a potential, and it is necessary to have an electric field in a narrow gap between the surface of the photosensitive member and the surface of the toner carrying member. Therefore, it is possible to use a method in which the elastic rubber of the elastic roller is resistance-controlled in the middle resistance region to keep the electric field while preventing conduction with the surface of the photoreceptor, or a method of providing a thin insulating layer on the surface layer of the conductive roller. . Further, a conductive resin sleeve in which the side facing the surface of the photoconductor is coated with an insulating material on the conductive roller, or a conductive layer is provided on the side not facing the photoconductor with an insulating sleeve is also possible. . Further, it is possible to employ a configuration in which a rigid roller is used as the toner carrying member and the photosensitive member is a flexible material such as a belt. The resistance value of the roller as the toner carrier is preferably in the range of 10 ^{2 to} 10 ⁹ Ω · cm.

  As the surface shape of the toner carrier, when the surface roughness Ra (μm) is set to 0.1 to 3.0, both high image quality and high durability can be achieved. The surface roughness Ra correlates with the toner conveying ability and the toner charging ability. When the surface roughness Ra of the toner carrier exceeds 3.0, it is difficult not only to make the toner layer on the toner carrier thin, but also the chargeability of the toner is not improved, so that improvement in image quality cannot be expected. . Since the toner carrying ability on the surface of the toner carrier is suppressed by setting it to 3.0 or less, the toner layer on the toner carrier is thinned, and the number of contact between the toner carrier and the toner increases. Since the chargeability of the toner is also improved, the image quality is synergistically improved. On the other hand, when the surface roughness Ra is smaller than 0.1, it becomes difficult to control the toner coat amount.

  In the present invention, the surface roughness Ra of the toner carrier is in accordance with Japanese Industrial Standard (JIS) B06014.2.1 (revision date January 20, 2001, confirmation date July 20, 2005). Arithmetic mean roughness determined. In the present invention, a surface roughness measuring device (Surfcoder SE3500 manufactured by Kosaka Laboratory Co., Ltd.) was used to measure from an arbitrary point on the surface of the toner carrier in a direction parallel to the rotation axis of the toner carrier. The cut-off value was 0.8 mm, the measurement length was 2.5 mm, and the measurement speed was 0.1 mm / second.

  In the image forming method of FIG. 4, the toner carrying member rotates in the same direction as the peripheral speed of the photosensitive member, but may rotate in the opposite direction. When the rotation is in the same direction, it is preferable to set the peripheral speed of the toner carrying member to be 1.05 to 3.0 times the peripheral speed of the photosensitive member.

  When the peripheral speed of the toner carrier is less than 1.05 times the peripheral speed of the photoreceptor, the stirring effect received by the toner on the photoreceptor is insufficient, and good image quality cannot be expected. On the other hand, when the peripheral speed ratio exceeds 3.0 times, toner deterioration due to mechanical stress and toner adhesion to the toner carrier are generated and promoted, which is not preferable.

  When the toner carrier is an elastic roller, a structure having an elastic layer on the surface is preferably used. The hardness of the material of the elastic layer used for the elastic roller is preferably 30 to 60 degrees (ASKER-C / load 1 kg).

  Further, the toner coating amount is controlled by the toner regulating member 44, and the toner regulating member 44 is in contact with the developing roller 40 through the toner layer. At this time, the contact pressure between the toner regulating member 44 and the developing roller 40 is preferably in a range of 0.05 N / cm to 0.5 N / cm as a linear pressure.

  The linear pressure is a load applied per length of the toner regulating member. For example, when a 1.2 N load is applied to the toner regulating member having a contact length of 1 m and brought into contact with the developing roller. The linear pressure is 1.2 N / m. If the linear pressure is less than 0.05 N / cm, it is difficult to control the toner coating amount and uniform triboelectric charging, resulting in fogging. On the other hand, if the linear pressure is higher than 0.5 N / cm, the toner particles are subjected to an excessive load, and therefore, deformation of the particles and adhesion of the toner to the toner regulating member or the developing roller are likely to occur.

  The free end portion of the toner regulating member 44 may have any shape. For example, in addition to a linear cross-sectional shape, an L-shape that is bent near the tip, or a shape that bulges in the vicinity of the tip. Etc. are preferably used.

  As the toner regulating member, a material in which a metal elastic body such as stainless steel, steel, phosphor bronze or the like is used as a base material and a resin is adhered or coated on a portion that contacts the sleeve contact portion is preferably used.

  Furthermore, by applying a DC electric field and / or an AC electric field to the toner regulating member, the uniform thin layer coating property and the uniform charging property are further improved due to the loosening action on the toner, and sufficient image density is achieved. A good quality image can be obtained.

<Image forming apparatus>
FIG. 5 is a schematic cross-sectional view showing an example of an image forming apparatus to which the image forming method of the present invention is applied. The image forming apparatus 100 has four image forming stations Pa, Pb, Pc, and Pd arranged in parallel in the vertical direction. The process cartridges 7 (7a, 7b, 7c, 7d) are detachably attached to the image forming stations Pa, Pb, Pc, Pd by attachment means (not shown). The magenta, cyan, yellow, and black cartridges 7a, 7b, 7c, and 7d have the same configuration.

  In this schematic diagram, the image forming stations Pa, Pb, Pc, and Pd are arranged side by side with a slight inclination in the vertical direction, but they may be arranged in the vertical direction without being inclined. Further, the process cartridge 7 may be the same as that illustrated in FIG. 4 or may be different.

  Each cartridge 7 (7a, 7b, 7c, 7d) includes a photosensitive drum 1 (1a, 1b, 1c, 1d). The photosensitive drum 1 is driven to rotate counterclockwise in the drawing by a driving means (not shown). Around the photosensitive drum 1, the following means are provided in order according to the rotation direction. (A) Charging means 2 (2a, 2b, 2c, 2d) for uniformly charging the surface of the photosensitive drum 1. (B) A scanner unit 3 (3a, 3b, 3c, 3d) that irradiates a laser beam based on image information to form an electrostatic latent image on the photosensitive drum 1. (C) Developing means 4 (4a, 4b, 4c, 4d) for developing a toner image by attaching a developer (hereinafter referred to as “toner”) to the electrostatic latent image. (D) A transfer device 5 that transfers the toner image on the photosensitive drum 1 to the recording medium S. (E) Cleaning means 6 (6a, 6b, 6c, 6d) for removing the toner remaining on the surface of the photosensitive drum 1 after transfer.

  Here, the photosensitive drum 1 and the charging means 2, the developing means 4, and the cleaning means 6, which are process means, are integrally constituted by a cartridge frame to form a cartridge to constitute a cartridge 7.

  The photosensitive drum 1 (1a, 1b, 1c, 1d) is configured by providing a photosensitive layer on the outer peripheral surface of a cylinder. Both ends of the photosensitive drum 1 are rotatably supported by support members. Then, when a driving force from a driving motor (not shown) is transmitted to one end portion, it is rotationally driven counterclockwise.

As the photoconductor, a photoconductor drum having a photoconductive insulating material layer such as a-Se, CdS, ZnO ₂ , OPC, or a-Si is preferably used. Further, the binder resin of the organic photosensitive layer in the OPC photoreceptor is not particularly limited. Among them, polycarbonate resin, polyester resin, and acrylic resin are particularly preferable because they are excellent in transferability and hardly cause toner fusion to the photoreceptor and filming of external additives.

  As the charging means 2 (2a, 2b, 2c, 2d), a contact charging type is used. The charging means 2 is a conductive roller formed in a roller shape. The roller is brought into contact with the surface of the photosensitive drum 1 and a charging bias voltage is applied to the roller. As a result, the surface of the photosensitive drum 1 is uniformly charged.

  As a preferable process condition when the charging roller is used, the contact pressure of the roller is 0.05 to 5 N / cm as a linear pressure. As the applied voltage, a DC voltage or a DC voltage superimposed with an AC voltage is preferably used. When a DC voltage superimposed with an AC voltage is used, it is preferable that AC voltage = 0.5 to 5 dVpp, AC frequency = 50 Hz to 5 kHz, and DC voltage = ± 0.2 to ± 1.5 kV. When a DC voltage is used, the DC voltage is preferably ± 0.2 to ± 5 kV.

  As charging means other than the charging roller, there are a method using a charging blade and a method using a conductive brush. These contact charging means have an effect that a high voltage is unnecessary and generation of ozone is reduced as compared with non-contact corona charging. The material of the charging roller and charging blade as the contact charging means is preferably conductive rubber, and a release coating may be provided on the surface thereof. As the releasable coating, nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride), and the like are applicable.

  In the scanner unit 3 (3a, 3b, 3c, 3d), a laser diode (not shown) passes image light corresponding to an image signal through a polygon mirror (not shown) and an imaging lens (not shown) rotated at high speed. Then, the surface of the charged photosensitive drum 1 is exposed according to image information. As a result, an electrostatic latent image is formed on the photosensitive drum.

  The developing means 4 (4a, 4b, 4c, 4d) is composed of a toner container 41 that stores magenta, cyan, yellow, and black toners, respectively, and feeds toner in the toner container 41. To the toner supply roller 43.

  The toner supply roller 43 rotates in the clockwise direction in the figure, and supplies toner to the developing roller 40 as a toner carrying member and does not contribute to the development of the electrostatic latent image. Perform stripping.

  The toner supplied to the developing roller 40 is applied to the outer periphery of the developing roller 40 (rotated clockwise) by the toner regulating member 44 pressed against the outer periphery of the developing roller 40, and is given an electric charge. Then, a developing bias is applied to the developing roller 40 facing the photosensitive drum 1 on which the latent image is formed. Then, toner development is performed on the photosensitive drum 1 in accordance with the latent image.

  The transfer device 5 is provided with an electrostatic transfer belt 11 that circulates and moves so as to face and contact all the photosensitive drums 1 (1a, 1b, 1c, 1d). The transfer belt 11 is stretched around a driving roller 13, driven rollers 14a and 14b, and a tension roller 15, and electrostatically attracts the recording medium S to the outer peripheral surface on the left side in the drawing. The transfer belt 11 circulates so that the recording medium S is brought into contact with the photosensitive drum 1. As a result, the recording medium S is conveyed to the transfer position by the transfer belt 11 and the toner image on the photosensitive drum 1 is transferred.

  The transfer roller 12 (12a, 12b, 12c, 12d) is arranged in parallel at a position in contact with the inside of the transfer belt 11 and facing the four photosensitive drums 1 (1a, 1b, 1c, 1d). A bias is applied to the transfer rollers 12 at the time of transfer, and an electric charge is applied to the recording medium S via the electrostatic transfer belt 11. The toner image on the photosensitive drum 1 is transferred to the recording medium S in contact with the photosensitive drum 1 by the electric field generated at this time.

  The feeding unit 16 feeds and transports the recording medium S to the image forming stations Pa, Pb, Pc, and Pd. A plurality of recording media S are stored in the cassette 17 in the feeding unit 16. At the time of image formation, the feeding roller 18 (half-moon roller) and the registration roller 19 are driven and rotated according to the image forming operation. The feeding roller 18 separates and feeds the recording medium S in the cassette 17 one by one, and then stops the recording medium S by abutting against the registration roller 19. Thereafter, the registration roller 19 feeds the recording medium S to the electrostatic transfer belt 11 in synchronization with the rotation of the transfer belt 11 and the image writing position.

  The fixing unit 20 fixes the toner images of a plurality of colors transferred to the recording medium S. The fixing unit 20 includes a heating roller 21a and a pressure roller 21b that presses against the heating roller 21a and applies heat and pressure to the recording medium S. That is, the recording medium S to which the toner image formed on the photosensitive drum 1 has been transferred is conveyed by the pressure roller 21b and applied with heat and pressure by the heating roller 21a when passing through the fixing unit 20. As a result, a plurality of color toner images are fixed on the surface of the recording medium S.

  As an image forming operation, the cartridges 7 (7a, 7b, 7c, 7d) are sequentially driven in accordance with the image forming timing. In response to the driving, the photosensitive drums 1a, 1b, 1c, and 1d are rotationally driven in the counterclockwise direction. Then, the scanner units 3 corresponding to the respective cartridges 7 are sequentially driven. By this driving, the charging roller 2 applies a uniform charge to the peripheral surface of the photosensitive drum 1. The scanner unit 3 exposes the circumferential surface of the photosensitive drum in accordance with the image signal to form an electrostatic latent image on the circumferential surface of the photosensitive drum. The developing roller 40 in the developing unit 4 forms (develops) a toner image on the circumferential surface of the photosensitive drum 1 by transferring the toner to the low potential portion of the electrostatic latent image.

  At the timing when the leading edge of the toner image formed on the circumferential surface of the most upstream photosensitive drum 1 is rotated and conveyed to the point facing the transfer belt 11, the print start position of the recording medium S coincides with the point facing the transfer belt 11. Thus, the registration roller 19 rotates to feed the recording medium S to the transfer belt 11.

  The recording medium S is pressed against the outer periphery of the transfer belt 11 so as to be sandwiched between the suction roller 22 and the transfer belt 11. A voltage is applied between the transfer belt 11 and the suction roller 22. Electric charges are induced in the recording medium S that is a dielectric and the dielectric layer of the transfer belt 11, and the recording medium S is electrostatically adsorbed on the outer periphery of the transfer belt 11. Thereby, the recording medium S is stably adsorbed to the electrostatic transfer belt 11 and conveyed to the most downstream transfer unit.

  While being conveyed in this manner, the toner image on each photosensitive drum 1 is sequentially transferred to the recording medium S by an electric field formed between each photosensitive drum 1 and the transfer roller 12.

  The recording medium S to which the four color toner images are transferred is separated from the electrostatic transfer belt 11 by the curvature of the belt driving roller 13 and is carried into the fixing unit 20. After the toner image is heat-fixed by the fixing unit 20, the recording medium S is discharged out of the main body by the paper discharge roller 23 with the image surface facing down from the paper discharge unit 24.

  The present invention will be specifically described with reference to the following examples. However, this does not limit the present invention in any way. A method for producing toner particles will be described below. Unless otherwise specified, all parts and% in the examples and comparative examples are based on mass.

Example 1
To 900 parts of ion-exchanged water heated to 60 ° C., 9 parts of tricalcium phosphate and 11 parts of 10% hydrochloric acid are added, and the mixture is stirred at 10,000 rpm using a TK homomixer (manufactured by Special Machine Industries). An aqueous medium having a pH of 5.2 was prepared.

Further, the following materials were uniformly dissolved and mixed at 100 r / min with a propeller type stirring device to prepare a resin-containing monomer.
Styrene 30 parts n-Butyl acrylate 31 parts Polar resin 1: Styrene-methacrylic acid-methyl methacrylate copolymer (copolymerization ratio = 95.6: 1.7: 2.7, Mp = 69000, Mw = 68000, Tg = 102 ° C, acid value = 12.0 mg KOH / g, Mw / Mn = 2.1) 20.0 parts

In addition, the following formulation was dispersed with an attritor to obtain a colorant-containing monomer.
-Styrene 39.0 parts-C.I. I. Pigment Blue 15: 3 6.5 parts, charge control agent Bontron E-88 (manufactured by Orient Chemical Co., Ltd.) 1.0 part

Next, after the colorant-containing monomer and the resin pigment monomer are mixed to obtain an adjustment liquid, the adjustment liquid is heated to 60 ° C., and a hydrocarbon wax (melting point 77 ° C.) HNP-51, manufactured by Nippon Seiwa Co., Ltd.): 8 parts were added. Next, an ultrasonic oscillator as shown in FIG. 1 was introduced into the adjustment liquid, and dispersion and mixing were performed while irradiating ultrasonic waves from the ultrasonic irradiation unit into the adjustment liquid for 30 minutes. When the ultrasonic wave is oscillated, the ultrasonic output A is set to 5.2 kW, and the A / B is set to 65.0 W / cm ² where the ultrasonic output is A and the ultrasonic irradiation area is B. Further, when the colorant-containing polymerizable monomer composition to be ultrasonically treated is C (kg) and the total output of the ultrasonic generator is D (kW), C / D is set to 60 kg / kW and dispersed. -Mixing was performed.

  In this, 8.0 parts of a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition. The polymerizable monomer composition was put into the aqueous medium and stirred at 60 ° C. using a TK homomixer at 10,000 r / min for 30 minutes for granulation.

  Thereafter, the mixture was transferred to a propeller type agitator and reacted at 70 ° C. for 5 hours while stirring at 100 r / min, then heated to 80 ° C. and further reacted for 5 hours to produce toner particles. After completion of the polymerization reaction, the slurry containing the particles was cooled to room temperature (25 ° C.), and hydrochloric acid was added to the suspension to dissolve the calcium phosphate salt, followed by filtration and washing to obtain wet colored particles.

  Next, the particles were dried at a temperature of 40 ° C. for 12 hours to obtain colored particles, and the colored particles were classified by wind classification to obtain toner particles 1.

And the toner particles 100 parts of a BET value as an external additive is 170m ² / g, mixed with a Henschel mixer primary particle size hydrophobic silica fine powder 2.0 parts of 10 nm (Mitsui Miike Engineering Corporation) Thus, toner (A) was obtained. Table 1 shows the physical properties of Toner (A).

(Example 2)
In Example 1, toner (B) was obtained by the same method except that C / D was set to 30 kg / kW for the condition of ultrasonic wave irradiation, and dispersion and mixing were performed by irradiation for 15 minutes. Table 1 shows the physical properties of Toner (B).

(Example 3)
A toner (C) was obtained in the same manner as in Example 1 except that the ultrasonic wave was applied for 15 minutes to perform dispersion and mixing. Table 1 shows the physical properties of Toner (C).

Example 4
In Example 1, toner (D) was obtained by the same method except that C / D was set to 100 kg / kW for the condition of ultrasonic wave irradiation, and dispersion and mixing were performed by irradiation for 15 minutes. Table 1 shows the physical properties of Toner (D).

(Example 5)
In Example 1, toner (E) was obtained by the same method except that C / D was set to 30 kg / kW under the condition of ultrasonic wave irradiation and dispersion / mixing was performed. Table 1 shows the physical properties of Toner (E).

(Example 6)
In Example 1, toner (F) was obtained by the same method except that C / D was set to 30 kg / kW for the conditions of ultrasonic wave irradiation, and dispersion and mixing were performed by irradiation for 60 minutes. Table 1 shows the physical properties of Toner (F).

(Example 7)
In Example 1, toner (G) was obtained by the same method except that C / D was set to 160 kg / kW for the condition of ultrasonic wave irradiation, and the dispersion and mixing were performed by irradiation for 15 minutes. Table 1 shows the physical properties of Toner (G).

(Example 8)
In Example 1, an ultrasonic oscillator as shown in FIG. 2 was introduced, the ultrasonic output A was set to 5.2 kW, A / B to 305.9 W / cm ² , and C / D to 60 kg / kW, A toner (H) was obtained by the same method except that the dispersion and mixing were performed by irradiation for 30 minutes. Table 1 shows the physical properties of Toner (H).

Example 9
In Example 1, a styrene-α-methylstyrene-methacrylic acid-methyl methacrylate copolymer having a Tg of 122 ° C. as a polar resin (styrene / α-methylstyrene / methacrylic acid / methyl methacrylate = 65.60 / 30.00 / Toner (I) was obtained in the same manner except that 20.0 parts of 1.70 / 2.70) were added. Table 1 shows the physical properties of Toner (I).

(Example 10)
In Example 1, a styrene-α-methylstyrene-methacrylic acid-methyl methacrylate copolymer having a Tg of 122 ° C. as a polar resin (styrene / α-methylstyrene / methacrylic acid / methyl methacrylate = 65.60 / 30.00 / Toner (J) was obtained in the same manner except that 30.0 parts of 1.70 / 2.70) were added. Table 1 shows the physical properties of Toner (J).

(Example 11)
In Example 1, a styrene-methacrylic acid-methyl methacrylate-butyl acrylate copolymer (styrene / methacrylic acid / methyl methacrylate / butyl acrylate = 83.85 / 2.50 / 1. Toner toner (K) was obtained in the same manner except that 20.0 parts of 65 / 12.00) was added. Table 1 shows the physical properties of Toner (K).

Example 12
In Example 1, a styrene-methacrylic acid-methyl methacrylate-butyl acrylate copolymer (styrene / methacrylic acid / methyl methacrylate / butyl acrylate = 83.85 / 2.50 / 1. Toner (L) was obtained in the same manner except that 10.0 parts of 65 / 12.00) was added. Table 1 shows the physical properties of Toner (L).

(Example 13)
In Example 1, a styrene-α-methylstyrene-methacrylic acid-methyl methacrylate copolymer having a Tg of 132 ° C. as a polar resin (styrene / α-methylstyrene / methacrylic acid / methyl methacrylate = 55.60 / 40.00 / Toner (M) was obtained in the same manner except that 30.0 parts of 1.70 / 2.70) were added. Table 1 shows the physical properties of Toner (M).

(Example 14)
In Example 1, a styrene-methacrylic acid-methyl methacrylate-butyl acrylate copolymer (styrene / methacrylic acid / methyl methacrylate / butyl acrylate = 72.35 / 2.50 / 1. Toner (N) was obtained in the same manner except that 20.0 parts of 65 / 23.50) was added. Table 1 shows the physical properties of Toner (N).

(Example 15)
In Example 1, toner (O) was prepared in the same manner except that dispersion and mixing were performed using CLEA SS5 manufactured by M Technique Co., Ltd. shown in FIGS. 6 to 8 in place of the ultrasonic oscillator in the adjustment step. Got. Table 1 shows the physical properties of Toner (O).

  FIG. 6 is a partial cross-sectional view of the dispersing apparatus used in Example 15. FIG. 7 is a schematic cross-sectional view of the main part of the disperser or granulator shown in FIG. As shown in FIGS. 6 and 7, the disperser or the granulator includes the first holder 11 together with the first holder 11 and the second holder 21 and the second holder 21 arranged in front of (above) the first holder 11. , A supply mechanism P such as a pump for supplying a mixed liquid or a granulated liquid to the apparatus, and a contact pressure applying mechanism 4. The first holder 11 is provided with a first processing ring 10 and a rotation shaft 50. The first processing ring 10 (mating ring) is a metal annular body (shown in FIG. 8) and has a first processing surface 1 that is mirror-finished. The rotary shaft 50 is fixed to a fixing tool 51 such as a bolt at the center of the first holder 11, and an end thereof is connected to a rotary drive device 5 (rotary drive mechanism) such as an electric motor. The force is transmitted to the first holder 11 to rotate the first holder 11. The first processing ring 10 is attached to the front (upper part) of the first holder 11 concentrically with the rotation shaft 50, and rotates integrally with the first holder 11 by the rotation of the rotation shaft 50. The first processing surface 1 is exposed from the first holder 11 and faces the second holder 21 side. The case 3 is a bottomed container having a discharge part 32, and the first holder 11 is accommodated in the internal space 30.

  The second holder 21 is provided with a second processing ring 20, a mixed liquid or granulated liquid introducing portion 22, and a contact pressure applying mechanism 4. The second processing ring 20 (compression ring) is a metal annular body, is fixed, is mirror-finished second processing surface 2, and is positioned inside the second processing surface 2, and the second processing surface 2. A pressure receiving surface 23 (hereinafter referred to as a separation adjusting surface 23) adjacent to the surface 2 is provided. As shown in the figure, the separation adjusting surface 23 is formed as an inclined surface. The mirror surface processing applied to the second processing surface 2 employs the same method as that for the first processing surface 1. In addition, the same material as that of the first processing ring 10 is used for the material of the second processing ring 20. The separation adjusting surface 23 is adjacent to the inner peripheral surface of the annular second processing ring 20.

  The contact surface pressure imparting mechanism 4 presses the second treatment surface 2 against the first treatment surface 1 in a pressure contact state or a close state, and fluid pressure (mixed liquid produced by a supply mechanism such as a pump, A thin fluid film is generated by the balance with the force separating the two processing surfaces 1 and 2 by the pressure on the granular liquid. In other words, the thin fluid film keeps the distance between the processing surfaces 1 and 2 at a very small distance.

  Specifically, in this embodiment, the contact surface pressure applying mechanism 4 includes an accommodating portion 41, a spring receiving portion 42 provided on the deepest portion of the accommodating portion 41, a spring 43, and an air introducing portion 44. It is composed of.

  The housing part 41 is provided with the second processing ring 20 so that the position of the second processing ring 20 in the housing part 41 can be displaced deeply or shallowly (up and down). One end of the spring 43 is in contact with the back of the spring receiving portion 42, and the other end of the spring 43 is in contact with the front portion (upper portion) of the second processing ring 20 in the housing portion 42.

  In FIG. 6, as described above, a pressurized gas such as pressurized air is introduced from the air introduction portion 44 into the housing portion 41. By introducing such a pressurized gas such as air, a pressure chamber can be provided between the accommodating portion 41 and the second processing ring 20 and air pressure can be applied to the second processing ring 20 as a pressing force together with the spring 43. .

  The contact surface pressure imparting mechanism 4 supplies and adjusts a part of the pressing force (contact surface pressure), and also serves as a displacement adjustment mechanism and a buffer mechanism. Specifically, the contact surface pressure applying mechanism 4 is a displacement adjusting mechanism, and can follow the axial displacement due to the elongation or wear in the axial direction during starting or during operation by adjusting the air pressure, and can maintain the initial pressing force. Further, as described above, the contact surface pressure applying mechanism 4 also functions as a buffer mechanism for fine vibration and rotational alignment by adopting a floating mechanism that holds the second processing ring 20 in a displaceable manner.

  Further, even if there is a margin between the upper portion of the second processing ring 20 and the uppermost portion of the housing portion 41 in the housing portion 41, the contact surface pressure applying mechanism 4 has the spring 43 and the first processing surface 1. 2 The upper limit of the width of the gap between the processing surface 2 is defined. The contact surface pressure imparting mechanism 4 functions as a separation inhibiting unit that inhibits separation exceeding the regulation of the first processing surface 1 and the second processing surface 2.

  Even if the first processing surface 1 and the second processing surface 2 are not in contact with each other, the spring 43 defines the lower limit of the width of the gap between the first processing surface 1 and the second processing surface 2. It functions as a proximity deterring unit that deters the proximity of the first processing surface 1 and the second processing surface 2 that is less than the specified range.

  Using this dispersing apparatus, the rotational speed of the first processing ring is set to 8000 rpm, and 600 kPa of compressed air is introduced into the air introduction unit 44 to thereby obtain a surface pressure between the first processing ring 10 and the second processing ring 20. Then, the first mixed liquid is introduced from the container through the introducing portion 22 into the disperser at a flow rate of 200 g / min (12 kg / hr) using the supply mechanism P (tube pump) and dispersed for 30 minutes. Carried out. The finally obtained toner is defined as toner (O).

(Comparative Example 1)
A toner (a) was obtained in the same manner as in Example 1 except that the ultrasonic wave was not applied and dispersed and mixed. Table 1 shows the physical properties of Toner (a).

(Comparative Example 2)
A toner (b) was obtained in the same manner as in Example 1 except that 2.0 parts of divinylbenzene was added for polymerization. Table 1 shows the physical properties of Toner (b).

(Comparative Example 3)
Toner (c) was prepared in the same manner as in Example 1 except that the resin-containing monomer was obtained by changing the addition amount of styrene to 15.0 parts and the addition amount of n-butyl acrylate to 46.0 parts. Got. Table 1 shows the physical properties of Toner (c).

(Comparative Example 4)
Toner (d) was prepared in the same manner as in Example 1 except that the resin-containing monomer was obtained by changing the addition amount of styrene to 12.0 parts and the addition amount of n-butyl acrylate to 49.0 parts. Got. Table 1 shows the physical properties of Toner (d).

(Comparative Example 5)
In Example 1, toner (e) was prepared in the same manner except that the resin-containing monomer was obtained by changing the addition amount of styrene to 43.0 parts and the addition amount of n-butyl acrylate to 18.0 parts. Obtained. Table 1 shows the physical properties of Toner (e).

  The evaluation method and evaluation criteria of the present invention will be described below.

  As the image forming apparatus, a remodeled machine of LBP-5400 (manufactured by Canon), which is a commercially available laser printer (which performs light load fixing using a fixing film), was used.

  The remodeling points of the evaluation machine are as follows.

  (1) The process speed was set to 190 mm / sec by changing the gear and software of the evaluation machine main body.

  The cartridge used for evaluation was a cyan cartridge. That is, the product toner was extracted from a commercially available cyan cartridge, the inside was cleaned by air blow, and then the toner according to the present invention was filled for evaluation. In addition, the product toner was extracted from each of the magenta, yellow, and black stations, and evaluation was performed by inserting magenta, yellow, and black cartridges in which the toner remaining amount detection mechanism was disabled.

<Evaluation on fixability>
(Low-temperature fixability / high-temperature offset / rollability)
In a modified machine of LBP-5400 (manufactured by Canon Inc.), the developer is filled with 85 g of the toner described in the examples and comparative examples, and is placed in a room temperature and normal humidity (temperature 23.5 ° C., humidity 60% RH) environment. Leave for 24 hours. At this time, the transfer paper is also left as it is. Thereafter, an unfixed image was output at a process speed of 190 mm / s in the cyan single color mode in an environment of normal temperature and normal humidity (temperature 23.5 ° C., humidity 60% RH).

(Low temperature fixability)
As a transfer material, plain paper for copying machines (64 g / m ² paper) was used, and an unfixed image on which a solid image with a toner paste amount of 0.6 mg / cm ² was formed was obtained. This was fixed at a process speed of 200 mm / s using a fixing machine of IRC3200 (manufactured by Canon Inc.). The fixing temperature was in the range of 130 to 200 ° C. at intervals of 5 ° C. The image was reciprocated five times with sylbon paper applied with a load of 4.9 kPa, and the temperature at which the density reduction rate was 20% or more was evaluated as the minimum fixing temperature. A, B, and C are levels that do not cause a problem in use, while D is a level that causes a problem in use.

Evaluation criteria A: Lower fixing temperature is less than 145 ° C. B: Lower fixing temperature is 145 ° C. or more and less than 155 ° C. C: Lower fixing temperature is 155 ° C. or more and less than 165 ° C. D: Lower fixing temperature is 165 ° C. or more and 175 ° C. Less than

(High temperature offset resistance)
Xerox 4200 (manufactured by Xerox Co., Ltd.) (75 g / m ² paper) is used as the transfer material, the amount of toner in the solid image portion of the unfixed image is 0.6 mg / cm ² , and the entire area of 5 cm from the front end is placed on A4 sideways. Is a solid image portion, and an unfixed image having a solid white is obtained. This was fixed using a fixing machine of IRC3200 at a fixing temperature set within a temperature range of 170 to 200 ° C. at intervals of 5 ° C. Fixing was performed at a process speed of 50 mm / s. The level of the offset appearing on the white background was visually confirmed. A, B, and C are levels that do not cause a problem in use, while D is a level that causes a problem in use.

Evaluation criteria A: No offset was generated at all. B: A slight offset was generated at the end other than the portion where the paper was passed in A4 portrait orientation at a fixing temperature of 200.degree.
C: An offset occurred in the entire longitudinal direction at a fixing temperature of 200 ° C.
D: An offset occurred at the end portion other than the portion where the paper was passed in the A4 portrait orientation at a fixing temperature of 190 ° C.

(Winding property to fixing roller)
Evaluation was carried out using plain paper for copying machines (64 g / m ² paper) as a transfer material. A solid image with a toner paste amount of 1.1 mg / cm ² was placed from a position 1 mm from the leading edge of the transfer paper to obtain an unfixed image. This was fixed at a process speed of 150 mm using an IRC3200 fixing machine. At this time, when the fixing temperature was lowered by 5 ° C. from 175 ° C., the temperature at which the transfer paper was wound around the fixing roller was defined as the fixing roller winding temperature. A, B, and C are levels that do not cause a problem in use, while D is a level that causes a problem in use.

Evaluation criteria A: 155 ° C. or lower B: 160 ° C.
C: 165 ° C
D: 170 ° C

<Evaluation for developability>
In a modified machine of LBP-5400 (manufactured by Canon Inc.), a developing device filled with 200 g of the toner described in the examples and comparative examples is made and placed under normal temperature and normal humidity (temperature 23.5 ° C., humidity 60% RH) environment. Leave for 24 hours. At this time, the transfer paper is also left as it is. In the evaluation regarding developability, Xerox 4200 (manufactured by Xerox Co., Ltd.) (75 g / m ² paper) was used as the transfer paper. Then, in a normal temperature and humidity environment (temperature 23.5 ° C., humidity 60% RH), up to 25000 sheets of images with a printing ratio of 1% are in the intermittent mode (that is, the developer is put on for 10 seconds each time one sheet is printed out). The printer was printed out in a mode in which it was paused and toner development was promoted by preliminary operation of the developing device at the time of restart. At that time, image evaluation was performed on the items described below at the initial stage, after endurance of 10,000 sheets, and after endurance of 25,000 sheets.

(Image density)
The image density was measured by using a “Macbeth reflection densitometer RD918” (manufactured by Macbeth) to measure a relative density with respect to an image of a white background portion having a document density of 0.00. A, B, and C are levels that do not cause a problem in use, while D is a level that causes a problem in use.

Evaluation criteria A: 1.40 or more B: 1.30 or more and less than 1.40 C: 1.20 or more and less than 1.30 D: 1.10 or more and less than 1.20

(Fog)
The fog evaluation method outputs an image having a white background portion, and the whiteness (reflectance Ds (%)) of the white background portion of the printout image measured by “REFLECTMETER MODEL TC-6DS” (manufactured by Tokyo Denshoku) and the transfer paper The fog density (%) (= Dr (%) − Ds (%)) was calculated from the difference in whiteness (average reflectance Dr (%)), and the image fog at the end of the durability evaluation was evaluated. An amberlite filter was used as the filter. A, B, and C are levels that do not cause a problem in use, while D is a level that causes a problem in use.

Evaluation criteria A: Less than 0.5% B: 0.5% or more and less than 1.0% C: 1.0% or more and less than 1.5% D: 1.5% or more and less than 5.0%

(Transferability)
Evaluation of transferability was performed by measuring transfer efficiency after initial, initial, and after 10,000 sheets and after initial and after 25,000 sheets. The transfer efficiency is determined by tapering the transfer residual toner on the photoconductor after the solid black image transfer with a Mylar tape and pasting it on the paper. The Macbeth density value is C, and the Mylar is applied on the paper with the toner after the fixing before the transfer. The Macbeth density of the tape with the tape applied was E, and the Macbeth density of the Mylar tape affixed on the unused paper was D, and approximately calculated by the following formula.

  The transfer efficiency was determined based on the transfer efficiency determined above based on the following criteria.

Evaluation criteria A: Very good (over 97%)
B: Good (less than 94 to 97%)
C: Practical use possible (less than 90-94%)
D: Not practical (less than 90%)

  If the transfer efficiency is 90% or more, there is no problem.

(Charge uniformity)
The charging uniformity was evaluated as follows.

That is, the particle size distribution of the toner in the cartridge after the initial and 10,000 sheets and after the initial and 25,000 sheets is measured in accordance with the above-described measuring method of the weight average particle diameter (D4). ) Based on the following formula, the particle size change rate was calculated and evaluated based on the following criteria.
Initial weight average particle diameter (D4) / weight average particle diameter after 10000 sheets (or after 25,000 sheets) (D4) × 100 = particle size change rate (%)

Evaluation criteria A: 95 ≦ particle size change rate (%) ≦ 100
B: 85 ≦ particle size change rate (%) <95
C: 75 ≦ particle size change rate (%) <85
D: Particle size change rate (%) <75
A is the best and D is the worst.

(Parts contamination)
The member contamination was evaluated based on the following criteria by visually observing the state of toner and external additives adhering to the surface of the developer carrying member and the effect on the obtained image.

Evaluation criteria A: Not generated (no sticking)
B: Although sticking occurs slightly, the influence on the image is small. C: Sticking occurs, and image unevenness is slightly caused by this, but there are few problems in practical use.
D: There is a large amount of fixation, resulting in image unevenness. There are also practical problems.

(Evaluation tests 1 to 15 and Comparative evaluation tests 1 to 5)
Table 2 shows the results of the evaluation performed on the toners (A) to (O) of Examples 1 to 15 and the toners (a) to (e) of Comparative Examples 1 to 3.

It is a load-displacement curve in a toner microcompression test. It is an expanded sectional view of one embodiment of the ultrasonic oscillation device by the present invention. It is an expanded sectional view of one embodiment of the ultrasonic oscillation device by the present invention. 2 is a cross-sectional view of an electrophotographic apparatus used for evaluating the toner of the present invention. FIG. It is an enlarged view of the developing unit of the electrophotographic apparatus. FIG. 6 is a partial cross-sectional view of a dispersing device used in a toner manufacturing adjustment process. It is a principal part schematic sectional drawing of the apparatus shown in FIG. It is explanatory drawing of the 1st process ring of the apparatus shown in FIG.

Explanation of symbols

Pa, Pb, Pc, Pd Image forming station 1 (1a to 1d) Photosensitive drum (image carrier)
2 (2a to 2d) Charging means 3 (3a to 3d) Scanner unit 4 (4a to 4d) Developing means 4A Developing unit 5 Electrostatic transfer device 6 (6a to 6d) Cleaning means 7 (7a to 7d) Process cartridge 11 Static Electrotransfer belt 12 (12a to 12d) Transfer roller 13 Belt drive rollers 14a and 14b Driven roller 15 Tension roller 16 Feeding unit 17 Cassette 18 Feeding roller 19 Registration roller 20 Fixing unit 21a Heating roller 21b Pressure roller 22 Adsorption roller 23 Paper discharge roller 24 Paper discharge unit 31 Cleaning frame (cartridge frame)
35 Removal toner storage chamber 40 Developing roller (toner carrier)
41 Toner container (developer storage part)
42 Toner transport mechanism 43 Toner supply roller 44 Toner regulating member (blade)
45 (45a, 45b, 45e) Development frame (cartridge frame)
47, 48 Bonding hole 50 Cleaner unit 60 Cleaning blade 62 Support roller (rotating body)
63 Belt support 64c Surface protective layer 100 Image forming apparatus main body S Recording medium (recording material sheet)

Claims (7)

A toner having toner particles containing at least a binder resin, a colorant, and a wax component, and an inorganic fine powder,
Obtained when a maximum load of 2.94 × 10 ⁻⁴ N is reached at a measurement temperature of 25 ° C. and a load speed of 9.8 × 10 ⁻⁵ N / sec in the minute compression test for the toner. Displacement amount (μm) is displacement amount X ₂ , and after reaching the maximum load, the displacement amount (μm) obtained by leaving the maximum load for 0.1 second is left as maximum displacement amount X ₃ for 0.1 second. Thereafter, the load is reduced at an unloading speed of 9.8 × 10 ⁻⁵ N / sec, and the displacement amount (μm) obtained when the load becomes 0 N is defined as the displacement amount X ₄ , the maximum displacement amount X ₃ and the displacement amount. The difference from X ₄ is the elastic displacement amount (X ₃ −X ₄ ), and the percentage of the elastic displacement amount (X ₃ −X ₄ ) with respect to the maximum displacement amount X ₃ [{(X ₃ −X ₄ ) / X ₃ } × 100: Restoration rate] is Z (25) (%), Z (25) is
40 ≦ Z (25) ≦ 80
Satisfied with the relationship
Wherein not more than the maximum displacement of the average value of X ₃ is 0.10μm or more 0.80 .mu.m, the toner having the maximum displacement X ₃ within ± 20% of the average value of the maximum displacement X ₃ (X ₃ existence ratio) The toner is present in an amount of 65% to 100% by number. In microscopic compression test on the toner particles, wherein the maximum toner having the maximum displacement X ₃ within the average value ± 20% of the displacement amount X ₃ in (X ₃ existence ratio) that is present at 70% by number to 98% by number or less The toner according to claim 1. In microscopic compression test on the toner particles, wherein the maximum toner having the maximum displacement X ₃ within the average value ± 20% of the displacement amount X ₃ in (X ₃ existence ratio) that is present at 95% by number or less 75% by number or more The toner according to claim 1, wherein: In the load-displacement curve in which the load and the amount of displacement in the micro-compression test for the toner are plotted, the slope of the load-displacement curve from the origin to the maximum load is represented by R (25) [2.94 × 10 ⁻⁴ / Displacement amount X ₂ (N / μm)], R (25) is
0.49 × 10 ⁻³ ≦ R (25) ≦ 1.70 × 10 ⁻³
The toner according to claim 1, wherein the toner satisfies the following relationship. In a micro-compression test for the toner, a load was applied to the toner particle at a load speed of 9.8 × 10 ⁻⁵ N / sec at a measurement temperature of 50 ° C., and a maximum load of 2.94 × 10 ⁻⁴ N was reached. The displacement amount (μm) obtained sometimes is the displacement amount X ′ ₂ , and after reaching the maximum load, the displacement amount (μm) obtained by leaving it at the maximum load for 0.1 second is the maximum displacement amount X ′ ₃ , After leaving for 0.1 seconds, the load is reduced at an unloading speed of 9.8 × 10 ⁻⁵ N / sec, and the displacement amount (μm) obtained when the load becomes 0 N is defined as the displacement amount X ′ ₄ , the maximum The difference between the displacement amount X ′ ₃ and the displacement amount X ′ ₄ is defined as an elastic displacement amount (X ′ ₃ −X ′ ₄ ), and the maximum displacement amount X ′ _{3 of the} elastic displacement amount (X ′ ₃ −X ′ ₄ ). When the percentage [{(X ′ ₃ −X ′ ₄ ) / X ′ ₃ } × 100: restoration rate] to Z (50) (%) is Z (50),
10 ≦ Z (50) ≦ 55
The toner according to claim 1, wherein the toner satisfies the following relationship.   Dispersing step of dispersing at least a colorant in a polymerizable monomer to obtain a colorant-containing monomer, dissolving step of obtaining a resin-containing monomer by dissolving at least a resin in the polymerizable monomer, and containing the obtained colorant Toner particles having at least a preparation step of mixing a monomer and a resin-containing monomer to obtain an adjustment liquid, and a granulation step of dispersing the adjustment liquid in an aqueous dispersion to produce particles of a polymerizable monomer composition A toner obtained by the production method of claim 1, wherein the adjustment step mixes the colorant-containing monomer and the resin-containing monomer with an ultrasonic generator to obtain an adjustment liquid. The toner according to claim 1, which has toner particles obtained by the above process.   The ultrasonic generator has a vibrator for irradiating ultrasonic waves having convex portions in the circumferential direction of a cylinder, and the convex portions are convex portions that form concentric circles with respect to the cylinder, 7. The toner according to claim 6, wherein the toner is obtained by mixing the colorant-containing monomer and the resin-containing monomer by vibrating the vibrator.

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