JP4367438B2 - Toner for developing electrostatic image and image forming method - Google Patents

Description

  The present invention relates to an electrostatic image developing toner and an image forming method.

  As a method for forming a color image, the latent image formed on the latent image carrier is developed with toner, and the toner image is not directly transferred onto the image forming support, but temporarily transferred to the intermediate transfer member, Thereafter, an image forming method is known in which the image is transferred onto an image forming support and then fixed. In this method, since the transfer process is performed a plurality of times, a toner having stable chargeability is required.

  Conventionally, a toner prepared by the pulverization method has a material dispersed in the toner non-uniformly on the fracture surface, and the surface property between the toners is not easily constant, and variations in the transfer process are likely to occur. As a result, there is a problem that the color reproducibility is reduced.

  Also, there is a so-called polymerized toner prepared by a polymerization method, and among these polymerized toners, a suspension polymerization method toner can form a toner having a spherical shape and a uniform surface property. The nature is expected to be higher. However, when the shape is spherical, the adhesion to the latent image carrier increases, and there is a problem that transferability is lowered.

  Therefore, in an image forming method using an intermediate transfer member, there has been a demand for an electrostatic charge image developing toner capable of obtaining a stable image over a long period of time and an image forming method using the same.

  An object of the present invention is to provide an electrostatic charge image developing toner capable of obtaining a stable image over a long period of time and an image forming method using the same.

The above object of the present invention has been achieved by the following constitutions 1 to 5 .

1. A step of forming a latent image on the latent image carrier, a step of developing the formed latent image with a developer containing toner, a step of transferring the formed toner image onto an intermediate transfer member, and the transferred toner An electrostatic charge image developing toner used in an image forming method including a step of transferring an image onto an image forming support and a step of fixing a toner image formed on the image forming support. Toner particles containing a colorant and having no corners (in a circle C having a radius (L / 10), where the major axis of the toner particles T is L), one point inside the peripheral line of the toner particles T The ratio of the toner particles in which the circle C does not substantially protrude outside the toner T when the inner surface is rolled while being in contact with the toner) is 50% by number or more, and the number variation coefficient in the number particle size distribution is 27. % is formed from the toner particles is less, and, Serial electrostatic image developing toner, wherein the proportion of toner particles in the range of shape factor of 1.2 to 1.6, which is defined is 65 number% or more by formula.
Shape factor = ((maximum diameter / 2) ² × π) / projection area

2. The 1 Symbol mounting of the toner for electrostatic image development, wherein the number average particle size of the toner particles is 3 to 8 [mu] m.

3. 3. The toner for developing an electrostatic charge image according to 1 or 2 above, which is obtained by polymerizing a polymerizable monomer in an aqueous medium.

4). 4. The electrostatic image developing toner according to any one of 1 to 3 , wherein the toner is obtained by associating resin particles in an aqueous medium.

5). 5. A step of forming a latent image A corresponding to a yellow image on a latent image carrier using the electrostatic charge image developing toner according to any one of 1 to 4 , and developing the latent image A with yellow toner Developing with an agent, transferring the formed yellow toner image onto an intermediate transfer member, forming a latent image B corresponding to a magenta image on the latent image carrier, and applying the magenta toner to the latent image B A step of developing with the developer, a step of transferring the formed magenta toner image onto the intermediate transfer member, a step of forming a latent image C corresponding to a cyan image on the latent image carrier, A step of developing with a developer containing cyan toner, a step of transferring the formed cyan toner image onto the intermediate transfer member, a step of forming a latent image D corresponding to a black image on the latent image carrier, the latent image Develop image D with developer containing black toner A step of transferring the formed black toner image onto the intermediate transfer member, and the yellow toner image, the magenta toner image, the cyan toner image and the black toner image formed on the intermediate transfer member, In each of the image forming methods including the step of transferring onto the image forming support and the step of fixing the toner image formed on the image forming support, the shape factor (Ky) and variation of the shape factor of the yellow toner Coefficient (Kσy), number average particle size (Dy), number variation coefficient (Dσy) in the number particle size distribution, shape factor (Km) of the magenta toner, variation coefficient of shape factor (Kσm), number average particle size ( Dm), number variation coefficient (Dσm) in the number particle size distribution, shape factor (Kc) of the cyan toner, variation coefficient (Kσc) of the shape factor, number average particle size (Dc), number in the number particle size distribution The relationship among the variation coefficient (Dσc), the shape factor (Kb) of the black toner, the variation coefficient of the shape factor (Kσb), the number average particle diameter (Db), and the number variation coefficient (Dσb) in the number particle size distribution is as follows ( An image forming method represented by Formula 1) to Formula 4:

(Formula 1)
0 ≦ ((maximum value of Ky, Km, Kc, Kb) − (minimum value of Ky, Km, Kc, Kb)) / (maximum value of Ky, Km, Kc, Kb) ≦ 0.2
(Formula 2)
0 ≦ ((maximum value of Kσy to Kσb) − (minimum value of Kσy to Kσb)) / (maximum value of Kσy to Kσb) ≦ 0.30
(Formula 3)
0 ≦ ((maximum value from Dy to Db) − (minimum value from Dy to Db)) / (maximum value from Dy to Db) ≦ 0.15
(Formula 4)
0 ≦ (maximum value from Dσy to Dσb) − (minimum value from Dσy to Dσb) / (maximum value from Dσy to Dσb) ≦ 0.25

  According to the present invention, it is possible to provide an electrostatic image developing toner capable of obtaining a stable image over a long period of time and an image forming method using the same.

  In the toner for developing an electrostatic charge image according to the present invention, the toner for developing an electrostatic charge image capable of obtaining a stable image over a long period of time by having the structure according to any one of claims 1 to 5. And an image forming method using the toner can be provided.

  Hereinafter, details of each component according to the present invention will be sequentially described.

  As a result of intensive studies, the inventors of the present invention have developed an image forming method using an intermediate transfer method using toner having high releasability by adjusting physical parameters of toner particles to specific values as described below. Even in this case, it was found that the generated image can be stabilized, and the present invention has been completed.

  The electrostatic image developing toner of the present invention will be described.

  The toner for developing an electrostatic charge image of the present invention according to claim 1 is adjusted so that the ratio of toner particles having no corners is 50% by number or more and the number variation coefficient in the number particle size distribution is 27% or less. Consists of

  The “shape factor” of the toner of the present invention described above is expressed by the following formula and indicates the degree of roundness of the toner particles.

Shape factor = ((maximum diameter / 2) ² × π) / projection area Here, the maximum diameter is the distance between the parallel lines when the projected image of toner particles on a plane is sandwiched between two parallel lines. The maximum particle width. The projected area refers to the area of the projected image of the toner particles on the plane.

  In the present invention, this shape factor is obtained by taking a photograph in which the toner particles are magnified 2000 times with a scanning electron microscope, and then using “SCANNING IMAGE ANALYZER” (manufactured by JEOL Ltd.) based on this photograph. It was measured by performing analysis. At this time, the shape factor according to the present invention was measured by the above formula using 100 toner particles.

  In the toner according to the first aspect of the present invention, the ratio of the toner particles having the shape factor in the range of 1.2 to 1.6 is preferably adjusted to 65% by number or more, more preferably 70%. Number% or more.

  By adjusting the ratio of the toner particles having a shape factor in the range of 1.2 to 1.6 to 65% by number or more, the density of the toner particles in the transferred toner layer is increased, and the image forming support is provided. In retransfer, there is little change in transferability between colors, and good transferability can be maintained. Further, the toner particles are less likely to be crushed, the contamination of the charge imparting member is reduced, and the chargeability of the toner is stabilized. Therefore, there is little variation in adhesion between colors, and a color image can be stabilized.

  The method for controlling the shape factor is not particularly limited. For example, a method in which toner particles are sprayed in a hot air stream, a method in which toner particles are repeatedly applied with mechanical energy due to impact force in a gas phase, a method in which a toner is not dissolved in a solvent and a swirl flow is applied. There is a method in which toner particles having a shape factor of 1.2 to 1.6 are prepared and added to a normal toner so as to be within the range of the present invention. In addition, there is a method in which the entire shape is controlled at the stage of preparing a so-called polymerization method toner, and toner particles having a shape factor adjusted to 1.2 to 1.6 are similarly added to a normal toner for adjustment.

  Among the above methods, the polymerization toner is preferable because it is simple as a production method and has excellent surface uniformity as compared with the pulverized toner.

<Variation coefficient of toner shape factor>
The “shape coefficient variation coefficient” of the toner of the present invention is calculated from the following equation.

Coefficient of variation (%) = (S ₁ / K) × 100
In the formula, S ₁ represents the standard deviation of the shape factor of 100 toner particles, and K represents the average value of the shape factor.

  In the toner of the present invention, the variation coefficient of the shape factor is preferably 16% or less, and more preferably 14% or less. By adjusting the variation coefficient of the shape factor to 16% or less, the gap of the toner layer (powder layer) transferred to the intermediate transfer member is reduced, and the transfer property is changed even when the transfer to the image forming support is performed again. In addition, good transferability can be maintained, and the charge amount distribution becomes sharp and the image quality is improved.

  In order to uniformly control the shape factor of the toner and the variation coefficient of the shape factor without variation in lots, the resin particles (polymer particles) constituting the toner of the present invention are prepared (polymerized), and the resin particles are melted. In the process of controlling the attachment and shape, an appropriate process end time may be determined while monitoring the characteristics of the toner particles (colored particles) being formed.

  Monitoring means that a measuring device is incorporated in-line, and process conditions are controlled based on the measurement result. In other words, in the case of a polymerization method toner that is formed by incorporating measurement such as shape in-line, for example, by associating or fusing resin particles in an aqueous medium, the shape and particle size are measured while performing sequential sampling in the fusing step. The reaction is stopped when the desired shape is obtained.

  Although it does not specifically limit as a monitoring method, The flow type particle image analyzer FPIA-2000 (made by Toa Medical Electronics Co., Ltd.) can be used. This apparatus is suitable because the shape can be monitored by performing image processing in real time while passing the sample liquid. That is, a pump or the like is used from the reaction field and is constantly monitored to measure the shape and the like, and the reaction is stopped when the desired shape is obtained.

《Toner number variation coefficient》
The number particle size distribution and the number variation coefficient of the toner of the present invention are measured by a Coulter Counter TA- or Coulter Multisizer (manufactured by Coulter Inc.). In the present invention, a Coulter Multisizer is used, and an interface (manufactured by Nikkaki Co., Ltd.) for outputting the particle size distribution and a personal computer are connected. The aperture used in the Coulter Multisizer was 100 μm, and the volume and number of toners of 2 μm or more were measured to calculate the particle size distribution and average particle size. The number particle size distribution represents the relative frequency of the toner particles with respect to the particle size, and the number average particle size represents the median diameter in the number particle size distribution. The “number variation coefficient in the number particle size distribution” of the toner is calculated from the following equation.

Number variation coefficient (%) = (S ₂ / D _n ) × 100
In the formula, S ₂ represents the standard deviation in the number particle size distribution, and D _n represents the number average particle size (μm).

  The number variation coefficient of the toner of the present invention described in claim 1 is 27% or less, preferably 25% or less. By adjusting the number variation coefficient to 27% or less, voids in the toner layer (powder layer) transferred to the intermediate transfer member are reduced, and transferability at the time of retransfer to the image forming support is improved. In addition, the charge amount distribution becomes sharp, the transfer efficiency increases, and the image quality improves.

  The method for controlling the number variation coefficient in the toner of the present invention is not particularly limited. For example, a method of classifying toner particles by wind force can be used, but classification in a liquid is effective for reducing the number variation coefficient. As a method of classifying in this liquid, there is a method of separating and collecting toner particles according to a difference in sedimentation speed caused by a difference in toner particle diameter by using a centrifuge and controlling the rotation speed.

  In particular, when a toner is produced by a suspension polymerization method, a classification operation is indispensable in order to make the number variation coefficient in the number particle size distribution 27% or less. In the suspension polymerization method, it is necessary to disperse a polymerizable monomer in an oil droplet having a desired size as a toner in an aqueous medium before polymerization. That is, mechanical shearing with a homomixer or homogenizer is repeated for large oil droplets of a polymerizable monomer to reduce the oil droplets to the size of toner particles. In the method using shearing, the number particle size distribution of the obtained oil droplets is wide, and therefore the particle size distribution of the toner obtained by polymerizing the oil droplets is also wide. For this reason, classification operation is essential.

<Percentage of toner particles without corners>
In the toner particles constituting the toner of the present invention, the ratio of toner particles having no corners is required to be 50% by number or more, and this ratio is preferably 70% by number or more.

  In the toner of the present invention described in claim 1 and the toner particles constituting the toner of the present invention described in claim 14, the ratio of toner particles having no corners in the toner particles is preferably 50% by number or more. More preferably, it is 70% by number or more.

  By adjusting the ratio of the toner particles having no corners to 50% by number or more, voids in the toner layer (powder layer) transferred to the intermediate transfer body are reduced, and the toner image is transferred to the image forming support again. Improves transferability and stabilizes image quality. In addition, toner particles that easily wear and break and toner particles having a portion where charges are concentrated are reduced, the charge amount distribution becomes sharp, the chargeability is stable, and good image quality can be formed over a long period of time.

  In the present invention, “toner particles having no corners” means toner particles that do not substantially have a protrusion that concentrates charges or a protrusion that easily wears due to stress. The particles are called toner particles having no corners. That is, as shown in FIG. 11A, when the major axis of the toner particle T is L, a circle C having a radius (L / 10) is in contact with the peripheral line of the toner particle T at one point inside. A case where the circle C does not substantially protrude outside the toner T when the inner side is rolled is referred to as “toner particles having no corners”. “A case where the protrusion does not substantially protrude” refers to a case where the protrusion having the protruding circle is one or less. The “major diameter of toner particles” refers to the width of a particle that maximizes the interval between the parallel lines when the projected image of the toner particles on a plane is sandwiched between two parallel lines. FIGS. 11B and 11C show examples of projected images of toner particles having corners.

  The ratio of toner particles having no corners was measured as follows. First, an enlarged photograph of the toner particles is taken with a scanning electron microscope, and further enlarged to obtain a 15,000 times photographic image. The photographic image is then measured for the presence or absence of the corners. This measurement was performed on 100 toner particles.

  A method for obtaining a toner having no corners is not particularly limited. For example, as described above as a method for controlling the shape factor, a method in which toner particles are sprayed into a hot air stream, a method in which toner particles are repeatedly applied with mechanical energy by impact force in a gas phase, or a toner is dissolved. It can be obtained by adding in a solvent that does not, and applying a swirling flow.

  Further, in the polymerization toner formed by associating or fusing the resin particles, the fusing particle surface has many irregularities at the fusing stop stage, and the surface is not smooth, but the temperature in the shape control step, By making the conditions such as the number of revolutions of the stirring blade and the stirring time appropriate, a toner having no corners can be obtained. These conditions vary depending on the physical properties of the resin particles. For example, by setting the number of revolutions to be higher than the glass transition temperature of the resin particles, the surface becomes smooth and a toner having no corners can be formed.

  Further, in the present invention, it has been found that the color reproducibility is expanded by arranging the toner particles of yellow, magenta, cyan, and black as toners for forming a color image.

  That is, the shape factor (Ky) of the yellow toner, the variation coefficient (Kσy) of the shape factor, the number average particle size (Dy), the number variation coefficient (Dσy) in the number particle size distribution, the shape factor (Km) of the magenta toner, Variation coefficient of shape factor (Kσm), number average particle diameter (Dm), number variation coefficient in number particle size distribution (Dσm), shape factor of cyan toner (Kc), variation coefficient of shape factor (Kσc), number average Particle size (Dc), number variation coefficient (Dσc) in number particle size distribution, shape factor (Kb) of black toner, variation coefficient of shape factor (Kσb), number average particle size (Db), number particle size distribution When the relationship of the number variation coefficient (Dσb) is expressed by the above (formula 1) to (formula 4), good transferability to the image forming support can be maintained even after the intermediate transfer step. Image forming method I can do it.

  Further, the toner particles on each intermediate transfer member are adjusted to toner particles in which the proportion of toner particles having no corners is 50% by number or more and the number variation coefficient in the number particle size distribution is 27% or less. The transferability can be made uniform, and image defects such as dust do not occur when transferred to the image forming support, and a good image can be formed.

<Toner particle size>
The toner of the present invention preferably has a number average particle diameter of 3 to 8 μm. When the toner particles are formed by a polymerization method, this particle size is determined in the toner production method described in detail later, in the concentration of the aggregating agent, the amount of organic solvent added, or the fusing time, and further the composition of the polymer itself. Can be controlled by.

  By adjusting the number average particle diameter to 3 to 8 μm, the thickness of the toner layer formed on the intermediate transfer member does not become excessive, and the transferability to the image forming support is improved. Further, since the transfer efficiency is increased, the image quality of halftone is improved, and the image quality of fine lines and dots is improved.

  As the toner of the present invention, when the particle diameter of the toner particles is D (μm), the natural logarithm ln (D) is taken on the horizontal axis, and the horizontal axis is divided into a plurality of classes at intervals of 0.23. In the histogram showing the particle size distribution, the sum (M1) of the relative frequency (m1) of the toner particles included in the most frequent class and the relative frequency (m2) of the toner particles included in the most frequent class after the most frequent class. ) Is preferably 70% or more.

  By adjusting the sum (M) of the relative frequency (m1) and the relative frequency (m2) to be 70% or more, the dispersion of the particle size distribution of the toner particles is narrowed. Can be reliably suppressed.

  In the present invention, the histogram showing the number-based particle size distribution includes a natural logarithm ln (D) (D: particle size of individual toner particles) at a plurality of classes (0 to 0.23: 0) at intervals of 0.23. 23 to 0.46: 0.46 to 0.69: 0.69 to 0.92: 0.92 to 1.15: 1.15 to 1.38: 1.38 to 1.61: 1.61 ~ 1.84: 1.84-2.07: 2.07-2.30: 2.30-2.53: 2.53-2.76 ...) This histogram is prepared by transferring the particle size data of a sample measured by a Coulter Multisizer to a computer via an I / O unit according to the following conditions, and by the particle size distribution analysis program in the computer. It is a thing.

〔Measurement condition〕
(1) Aperture: 100 μm
(2) Sample preparation method: Electrolyte [ISOTON R-11 (manufactured by Coulter Scientific Japan)] 50-100 ml, an appropriate amount of a surfactant (neutral detergent) was added and stirred, and a measurement sample 10-20 mg was added thereto. Add This system is prepared by dispersing for 1 minute with an ultrasonic disperser.

<Comparison with conventionally known toner>
The toner of the present invention comprises (a) a ratio of toner particles having a shape factor in the range of 1.2 to 1.6 (65% by number or more in the toner of the present invention according to claim 14), and (b) a shape factor. Coefficient of variation (16% or less in the toner of the present invention according to claim 1 and toner of the present invention according to claim 8), (c) the proportion of toner particles having no angle (the present invention according to claim 8) And (d) a number variation coefficient in the number particle size distribution (the toner of the present invention according to claim 1 and 27% or less in the toner of the present invention according to claim 8). It can be clearly distinguished compared with the toner of

  Regarding the numerical values described in the above (a) to (d) related to the toner of the present invention, conventionally known numerical values of the toner will be described. This value varies depending on the manufacturing method.

(For pulverized toner)
In the case of a conventionally known pulverized toner, the ratio of toner particles having a shape factor of 1.2 to 1.6 is about 60% by number. The variation coefficient of the shape factor of this is about 20%. Further, in the pulverization method, in order to reduce the particle size while repeating the crushing, the toner particles have more corners, and the proportion of toner particles without corners is 30% by number or less. Therefore, in order to obtain a rounded toner with uniform shapes and no corners, a process for spheroidizing with heat or the like as described above is required as a method for controlling the shape factor. In addition, the number variation coefficient in the number particle size distribution is about 30% when the classification operation after pulverization is one time, and in order to make the number variation coefficient 27% or less, it is necessary to repeat the classification operation. There is.

(Toner by suspension polymerization method)
The conventional toner is polymerized in a laminar flow, so that substantially spherical toner particles are obtained. For example, in the toner described in JP-A-56-130762, the shape factor is 1.2 to 1.6. The proportion of certain toner particles is about 20% by number, the coefficient of variation of the shape factor is about 18%, and the proportion of toner particles without corners is also about 85% by number. As described above, as a method for controlling the number variation coefficient in the number particle size distribution, mechanical shearing is repeatedly performed on large oil droplets of the polymerizable monomer to reduce the oil droplets to the size of toner particles. Therefore, the distribution of the oil droplet diameter is wide, and therefore the particle size distribution of the obtained toner is wide, the number variation coefficient is as large as about 32%, and classification operation is necessary to reduce the number variation coefficient. .

  In the polymerization toner formed by associating or fusing resin particles, for example, in the toner described in JP-A-63-186253, the proportion of toner particles having a shape factor of 1.2 to 1.6 is The variation coefficient of the shape factor is about 18%, and the proportion of toner particles without corners is about 44%. Further, the particle size distribution of the toner is wide, the number variation coefficient is 30%, and classification operation is necessary to reduce the number variation coefficient.

<Method for producing toner>
The toner of the present invention is preferably a toner obtained by polymerizing at least a polymerizable monomer in an aqueous medium, and is preferably a toner obtained by associating at least resin particles in an aqueous medium. . Hereinafter, the method for producing the toner of the present invention will be described in detail.

  In the toner of the present invention, fine polymer particles (resin particles) are prepared by emulsion polymerization of monomers in a suspension polymerization method or in a liquid (aqueous medium) to which an emulsion of necessary additives is added. Thereafter, an organic solvent, a flocculant and the like can be added to produce the resin particles in association with each other. Here, “association” means that a plurality of the resin particles are fused, and includes cases where the resin particles and other particles (for example, colorant particles) are fused.

  An example of the method for producing the toner of the present invention is as follows. A homogenizer is prepared by adding various constituent materials such as a colorant and, if necessary, a release agent, a charge control agent, and a polymerization initiator to the polymerizable monomer. Then, various constituent materials are dissolved or dispersed in the polymerizable monomer by a sand mill, a sand grinder, an ultrasonic disperser or the like. The polymerizable monomer in which these various constituent materials are dissolved or dispersed is dispersed in oil droplets having a desired size as a toner in an aqueous medium containing a dispersion stabilizer using a homomixer or a homogenizer. Thereafter, the stirring mechanism is transferred to a reaction device (stirring device) which is a stirring blade described later, and the polymerization reaction is advanced by heating. After completion of the reaction, the dispersion stabilizer is removed, filtered, washed, and dried to prepare the toner of the present invention.

  In the present invention, the “aqueous medium” refers to a medium containing at least 50% by mass of water. Further, as a method for producing the toner of the present invention, a method of preparing by associating or fusing resin particles in an aqueous medium can also be mentioned. The method is not particularly limited, and examples thereof include methods described in JP-A Nos. 5-265252, 6-329947, and 9-15904. That is, a method of associating a plurality of fine particles composed of resin particles and colorants, etc., or particles composed of resin and colorant, in particular, after dispersing them in water using an emulsifier, the critical aggregation concentration The above flocculant is added for salting out, and at the same time, the formed polymer itself is heated and fused at a temperature higher than the glass transition temperature to gradually grow the particle size while forming fused particles. Then, a large amount of water is added to stop the particle size growth, and the shape is controlled by smoothing the particle surface while heating and stirring, and the particles are heated and dried in a fluid state while containing water. The toner of the invention can be formed. Here, a solvent that is infinitely soluble in water may be added simultaneously with the flocculant.

  As the polymerizable monomer constituting the resin, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decyl Styrene, styrene or styrene derivatives such as pn-dodecylstyrene, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, Methacrylic acid ester derivatives such as lauryl tacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, acrylic Acrylates such as isobutyl acid, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate, olefins such as ethylene, propylene, isobutylene, vinyl chloride, vinylidene chloride, Halogenated vinyls such as vinyl bromide, vinyl fluoride, vinylidene fluoride, vinyl esters such as vinyl propionate, vinyl acetate, vinyl benzoate, vinyl methyl ether, vinyl ethyl ether Vinyl ethers such as tellurium, vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, N-vinyl compounds such as N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone, vinyl naphthalene, vinyl pyridine, etc. There are acrylic acid or methacrylic acid derivatives such as vinyl compounds, acrylonitrile, methacrylonitrile, acrylamide and the like. These vinyl monomers can be used alone or in combination.

  Further, it is more preferable to use a combination of monomers having an ionic dissociation group as the polymerizable monomer constituting the resin. For example, it has a substituent such as a carboxyl group, a sulfonic acid group, a phosphoric acid group as a constituent group of the monomer, specifically, acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumar Acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, styrene sulfonic acid, allyl sulfosuccinic acid, 2-acrylamido-2-methylpropane sulfonic acid, acid phosphooxyethyl methacrylate, 3-chloro-2-acid phosphooxy And propyl methacrylate.

  Furthermore, multifunctional such as divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, etc. It is also possible to use a crosslinkable resin by using a functional vinyl.

  These polymerizable monomers can be polymerized using a radical polymerization initiator. In this case, an oil-soluble polymerization initiator can be used in the suspension polymerization method. Examples of the oil-soluble polymerization initiator include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carboxyl). Nitriles), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo- or diazo-based polymerization initiators such as azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate , Cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis- (4,4- t-butylperoxycyclohexyl) propane, tris The (t-butylperoxy) triazine peroxide polymerization initiator or a peroxide, such as and the like polymeric initiator having a side chain.

  Moreover, when using an emulsion polymerization method, a water-soluble radical polymerization initiator can be used. Examples of the water-soluble polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropane acetate, azobiscyanovaleric acid and its salts, hydrogen peroxide and the like.

  Dispersion stabilizers include tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate , Bentonite, silica, alumina and the like. Furthermore, those generally used as surfactants such as polyvinyl alcohol, gelatin, methylcellulose, sodium dodecylbenzenesulfonate, ethylene oxide adduct, and higher alcohol sodium sulfate can be used as the dispersion stabilizer.

  As the resin excellent in the present invention, those having a glass transition point of 20 to 90 ° C. are preferred, and those having a softening point of 80 to 220 ° C. are preferred. The glass transition point is measured by a differential calorimetric analysis method, and the softening point can be measured by a Koka flow tester. Further, these resins preferably have a molecular weight measured by gel permeation chromatography of 1,000 to 100,000 in terms of number average molecular weight (Mn) and 2000 to 1,000,000 in terms of weight average molecular weight (Mw). Further, the molecular weight distribution is preferably such that Mw / Mn is 1.5 to 100, particularly 1.8 to 70.

  The flocculant used for associating the resin particles in an aqueous medium is not particularly limited, but those selected from metal salts are preferably used. Specifically, as a monovalent metal, for example, an alkali metal salt such as sodium, potassium or lithium, as a divalent metal, for example, an alkaline earth metal salt such as calcium or magnesium, or a divalent metal such as manganese or copper. And salts of trivalent metals such as iron and aluminum, and specific salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, etc. Can be mentioned. These may be used in combination.

  These flocculants are preferably added in an amount equal to or higher than the critical aggregation concentration. The critical flocculation concentration is an index relating to the stability of the aqueous dispersion, and indicates a concentration at which flocculation occurs when a flocculant is added. This critical aggregation concentration varies greatly depending on the emulsified components and the dispersant itself. For example, it is described in Seizo Okamura et al., “Polymer Chemistry 17, 601 (1960) edited by the Japanese Society of Polymer Science”, and the like, and can determine a detailed critical aggregation concentration. As another method, a desired salt is added to the target particle dispersion at different concentrations, the ζ (zeta) potential of the dispersion is measured, and the salt concentration at which this value changes is defined as the critical aggregation concentration. You can ask for it.

  The addition amount of the flocculant of the present invention may be not less than the critical aggregation concentration, but is preferably 1.2 times or more, more preferably 1.5 times or more the critical aggregation concentration.

  As the “solvent that dissolves infinitely in water” used together with the flocculant, a solvent that does not dissolve the formed resin is selected. Specific examples include alcohols such as methanol, ethanol, propanol, isopropanol, t-butanol, methoxyethanol, and butoxyethanol, nitriles such as acetonitrile, and ethers such as dioxane. In particular, ethanol, propanol, and isopropanol are preferable.

  The amount of the solvent that is infinitely soluble in water is preferably 1 to 100% by volume with respect to the polymer-containing dispersion added with the flocculant.

  In order to make the particle shape uniform, it is preferable to fluidly dry a slurry containing 10% by mass or more of water based on the particles after preparing and filtering colored particles. Those having a polar group therein are preferred. The reason for this is considered to be that it is particularly easy to make the shape uniform in order to exhibit the effect that the water present is somewhat swollen with respect to the polymer in which the polar group is present.

  The toner of the present invention contains at least a resin and a colorant, but may contain a release agent, a charge control agent, or the like, which is a fixability improving agent, if necessary. Further, an external additive composed of inorganic fine particles or organic fine particles may be added to the toner particles containing the resin and the colorant as main components.

  As the colorant used in the toner of the present invention, carbon black, a magnetic material, a dye, a pigment, and the like can be arbitrarily used. Examples of the carbon black include channel black, furnace black, acetylene black, thermal black, and lamp black. used. Magnetic materials include ferromagnetic metals such as iron, nickel and cobalt, alloys containing these metals, compounds of ferromagnetic metals such as ferrite and magnetite, alloys that do not contain ferromagnetic metals but exhibit ferromagnetism by heat treatment, For example, a kind of alloy called Heusler alloy such as manganese-copper-aluminum, manganese-copper-tin, chromium dioxide, or the like can be used.

  As the dye, C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95 etc. can be used, and a mixture thereof can also be used. Examples of the pigment include C.I. I. Pigment Red 5, 48: 1, 53: 1, 57: 1, 122, 139, 144, 149, 166, 177, 178, 222, C.I. I. Pigment Orange 31 and 43, C.I. I. Pigment Yellow 14, 17, 93, 94, 138, 155, 156, 180, 185, C.I. I. Pigment green 7, C.I. I. Pigment Blue 15: 3, 60, etc. can be used, and a mixture thereof can also be used. The number average primary particle size varies depending on the type, but is preferably about 10 to 200 nm.

  As a method for adding the colorant, the polymer particles prepared by the emulsion polymerization method are added at the stage of agglomerating by adding an aggregating agent, and the polymer is colored, or at the stage of polymerizing the monomer. The method of adding, polymerizing, and making it a colored particle etc. can be used. In addition, when adding a coloring agent in the step which prepares a polymer, it is preferable to use it, treating the surface with a coupling agent etc. so that radical polymerization property may not be inhibited.

  Further, a low molecular weight polypropylene (number average molecular weight = 1500 to 9000), a low molecular weight polyethylene, or the like as a fixing property improving agent may be added. Further, an ester wax can be used as a fixing improving material. Examples of the ester-based wax include carnauba wax, and can include candelilla wax and microcrystalline wax.

  The method for adding this fixability improver to the toner is not particularly limited. For example, the method for salting out / fusing the resin particles in the same manner as the colorant particles, and the fixability in the monomer for preparing the resin particles. There is also a method of preparing a resin particle by dissolving the improver and then polymerizing it.

  Similarly, various known charge control agents and those that can be dispersed in water can be used. Specific examples include nigrosine dyes, naphthenic acid or higher fatty acid metal salts, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, salicylic acid metal salts or metal complexes thereof.

  In addition, it is preferable that the number average primary particle diameter of these charge control agent and fixability improving agent particles is about 10 to 500 nm in a dispersed state.

  In the toner of the present invention, the effect can be further exhibited by adding and using fine particles such as inorganic fine particles and organic fine particles as external additives. The reason for this is presumed that the effect can be conspicuous because the burying and detachment of the external additive can be effectively suppressed.

  As the inorganic fine particles, inorganic oxide particles such as silica, titania, and alumina are preferably used, and these inorganic fine particles are preferably hydrophobized with a silane coupling agent or a titanium coupling agent. The degree of the hydrophobizing treatment is not particularly limited, but a methanol wettability of 40 to 95 is preferable. Methanol wettability is an evaluation of wettability to methanol. In this method, 0.2 g of inorganic fine particles to be measured is weighed and added to 50 ml of distilled water in a 200 ml beaker. Methanol is slowly added dropwise from a burette whose tip is immersed in the liquid until the whole of the inorganic fine particles become wet with slow stirring. When the amount of methanol necessary to completely wet the inorganic fine particles is a (ml), the degree of hydrophobicity is calculated by the following formula.

Hydrophobicity = (a / (a + 50)) × 100
The addition amount of the external additive is 0.1 to 5.0% by mass, preferably 0.5 to 4.0% by mass in the toner. In addition, various external additives may be used in combination.

  In a suspension polymerization method toner in which a toner component obtained by dispersing or dissolving a toner component such as a colorant in a so-called polymerizable monomer is suspended in an aqueous medium and then polymerized. The shape of the toner particles can be controlled by controlling the flow of the medium. That is, when a large amount of toner particles having a shape factor of 1.2 or more are formed, the flow of the medium in the reaction vessel is turbulent and the polymerization proceeds to exist in an aqueous medium in a suspended state. When the oil droplets gradually become polymerized, the oil droplets become soft particles. By colliding the particles, particle coalescence is promoted, and particles with an irregular shape are obtained. . In the case of forming substantially spherical toner particles having a shape factor of less than 1.2, substantially spherical particles can be obtained by using a laminar flow of the medium in the reaction vessel to avoid particle collision. By this method, the toner shape distribution can be controlled within the scope of the present invention.

<Reactor>
FIG. 1 is an explanatory view showing a reaction device (stirring device) having a generally used stirrer blade structure, wherein 2 is a stirrer tank, 3 is a rotating shaft, 4 is a stirrer blade, and 9 is a turbulent flow It is a forming member.

  In the suspension polymerization method, a turbulent flow can be formed by using a specific stirring blade, and the shape can be easily controlled. Although it is not clear as this reason, when the structure of the stirring blade 4 as shown in FIG. 1 is one stage, the flow of the medium formed in the stirring tank 2 is a wall surface from the lower part to the upper part of the stirring tank 2. It becomes only the flow that moves along. Therefore, conventionally, a turbulent flow is generally formed by arranging a turbulent flow forming member 9 such as a wall surface of the stirring tank 2 to increase the efficiency of stirring. However, in such an apparatus configuration, although the turbulent flow is partially formed, the fluid flow acts in the direction of stagnation due to the presence of the turbulent flow. I can't control it.

  A reactor equipped with a stirring blade that can be preferably used in the suspension polymerization method will be described with reference to the drawings.

  2 and 3 are a perspective view and a cross-sectional view showing an example of such a reaction apparatus, respectively. In the reaction apparatus shown in FIGS. 2 and 3, a rotating shaft 3 is vertically suspended at the center of a vertical cylindrical stirring tank 2 in which a jacket 1 for heat exchange is mounted on the outer periphery, and stirring is performed on the rotating shaft 3. A lower stirrer blade 40 disposed close to the bottom surface of the tank 2 and a stirrer blade 50 disposed further upward are provided. The upper agitating blade 50 is disposed with a crossing angle α preceding the agitating blade 40 located in the lower stage in the rotational direction. In the production of the toner of the present invention, the crossing angle α is preferably less than 90 degrees (°). The lower limit of the intersection angle α is not particularly limited, but is preferably about 5 ° or more, and more preferably 10 ° or more. When a three-stage stirring blade is provided, the crossing angle between adjacent stirring blades is preferably less than 90 degrees.

  By setting it as such a structure, a medium is first stirred by the stirring blade 50 arrange | positioned in the upper stage, and the flow to the lower side is formed. Next, the flow formed by the upper stirring blade 50 is further accelerated downward by the stirring blade 40 disposed in the lower stage, and a downward flow is separately formed in the stirring blade 50 itself, and the flow as a whole is increased. Presumed to be accelerated and proceed. As a result, a flow area having a large shear stress formed as a turbulent flow is formed, and it is estimated that the shape of the obtained toner particles can be controlled.

  2 and 3, arrows indicate the rotation direction, 7 is an upper material inlet, 8 is a lower material inlet, and 9 is a turbulent flow forming member for making stirring effective.

  Here, the shape of the stirring blade is not particularly limited, but it may be a rectangular plate, a notch in a part of the blade, one or more holes in the center, and a so-called slit. Can be used. Specific examples of these are shown in FIG. The stirring blade 5a shown in FIG. 10 (a) has no medium hole, the stirring blade 5b shown in FIG. 10 (b) has a large middle hole 6b in the center, and the stirring blade 5c shown in FIG. 10 (c). Has a horizontally elongated hole 6c (slit), and the stirring blade 5d shown in FIG. 4D has a vertically elongated hole 6d (slit). In addition, when a three-stage stirring blade is provided, the middle hole formed in the upper stirring blade and the middle hole formed in the lower stirring blade may be the same, even if they are different. There may be.

  4 to 8 are perspective views showing specific examples of a reactor equipped with a stirring blade that can be preferably used. In FIGS. 4 to 8, 1 is a jacket for heat exchange, and 2 is a stirring device. A tank, 3 is a rotating shaft, 7 is an upper material inlet, 8 is a lower material inlet, and 9 is a turbulent flow forming member.

  In the reaction apparatus shown in FIG. 4, a bent portion 411 is formed on the stirring blade 41, and a fin (projection) 511 is formed on the stirring blade 51.

  In addition, when the bending part is formed in the stirring blade, it is preferable that a bending angle is 5-45 degrees.

  In the stirring blade 42 constituting the reaction apparatus shown in FIG. 5, a slit 421 is formed, and a bent portion 422 and fins 423 are formed.

  In addition, the stirring blade 52 which comprises the said reaction apparatus has a shape similar to the stirring blade 50 which comprises the reaction apparatus shown in FIG.

  Bending portions 431 and fins 432 are formed on the stirring blade 43 constituting the reaction apparatus shown in FIG.

  In addition, the stirring blade 53 which comprises the said reaction apparatus has the shape similar to the stirring blade 50 which comprises the reaction apparatus shown in FIG.

  Bending portions 441 and fins 442 are formed on the stirring blade 44 constituting the reaction apparatus shown in FIG.

  In addition, the stirring blade 54 constituting the reaction apparatus has a middle hole portion 541 formed at the center.

  The reaction apparatus shown in FIG. 8 is provided with a three-stage stirring blade including a stirring blade 45 (lower stage), a stirring blade 55 (middle stage), and a stirring blade 65.

  A stirring blade having a structure having these bent portions and protrusions (fins) to the upper or lower portion effectively generates turbulent flow.

  The gap between the upper and lower stirring blades having the above-described configuration is not particularly limited, but it is preferable to have a gap at least between the stirring blades. Although the reason for this is not clear, it is considered that the stirring efficiency is improved because a medium flow is formed through the gap. However, the gap has a width of 0.5 to 50%, preferably 1 to 30%, with respect to the liquid surface height in the stationary state.

  Further, the size of the stirring blade is not particularly limited, but the total height of all the stirring blades is 50% to 100%, preferably 60% to 95% of the liquid surface height in the stationary state. is there.

  FIG. 9 shows an example of a reaction apparatus used when a laminar flow is formed in the suspension polymerization method. This reaction apparatus is characterized in that a turbulent flow forming member (an obstacle such as a baffle plate) is not provided.

  The agitating blade 46 and the agitating blade 56 constituting the reaction apparatus shown in FIG. 9 have the same shape and crossing angle α as the agitating blade 40 and the agitating blade 50 constituting the reaction apparatus shown in FIG. . In FIG. 9, 1 is a heat exchange jacket, 2 is a stirring tank, 3 is a rotating shaft, 7 is an upper material inlet, and 8 is a lower material inlet.

  In addition, as a reaction apparatus used when forming a laminar flow, it is not limited to what is shown by FIG.

  In addition, the shape of the stirring blades constituting such a reactor is not particularly limited as long as it does not form turbulent flow, but is preferably formed by a continuous surface such as a rectangular plate, and has a curved surface. You may do it.

  On the other hand, in a polymerization method toner that associates or fuses resin particles in an aqueous medium, by controlling the flow and temperature distribution of the medium in the reaction vessel at the fusing stage, and further in the shape control step after fusing. By controlling the heating temperature, the number of rotations of stirring, and the time, the shape distribution and shape of the entire toner can be arbitrarily changed.

  That is, in the polymerization method toner that associates or fuses the resin particles, the flow in the reaction apparatus is made into a laminar flow, and the agitation step and the agitation tank that can make the internal temperature distribution uniform are used. By controlling the temperature, the number of rotations, and the time in the shape control step, it is possible to form a toner having a desired shape factor and uniform shape distribution. The reason for this is that if the laminar flow is fused in the place where the laminar flow is formed, the particles that are agglomerated and fused (aggregated or agglomerated particles) are not subjected to strong stress, and the laminar flow in which the flow is accelerated It is estimated that this is because the shape distribution of the fused particles becomes uniform as a result of the uniform temperature distribution in the stirring tank. Further, the fused particles gradually become spherical by heating and stirring in the subsequent shape control step, and the shape of the toner particles can be arbitrarily controlled.

  As the stirring blade and the stirring tank used in the production of the polymerization toner for associating or fusing the resin particles, those similar to the case of forming a laminar flow in the suspension polymerization method described above can be used. 9 can be used. It is characterized in that no obstacle such as a baffle plate that forms a turbulent flow is provided in the stirring tank. As for the configuration of the stirring blade, like the stirring blade used in the above-described suspension polymerization method, the upper stirring blade is disposed with a crossing angle α preceding the lower stirring blade in the rotational direction. In addition, a multistage configuration is preferable.

  The shape of the stirring blade is not particularly limited as long as it does not form a turbulent flow as long as it does not form a turbulent flow as in the case of forming a laminar flow in the above-described suspension polymerization method. Those formed by a continuous surface, such as a rectangular plate shape, are preferable, and may have a curved surface.

  The toner of the present invention may be used, for example, as a one-component magnetic toner containing a magnetic material, used as a two-component developer mixed with a so-called carrier, or a non-magnetic toner alone. However, in the present invention, it is preferably used as a two-component developer used by mixing with a carrier.

  The developing method in which the toner of the present invention can be used is not particularly limited.

  The volume average particle diameter of the carrier that can be used as the two-component developer is preferably 15 to 100 μm, and more preferably 25 to 60 μm. The volume average particle diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.

  The carrier is preferably further coated with a resin, or a so-called resin dispersion type carrier in which magnetic particles are dispersed in the resin. The resin composition for coating is not particularly limited, and for example, olefin resin, styrene resin, styrene / acrylic resin, silicone resin, ester resin, or fluorine-containing polymer resin is used. The resin for constituting the resin-dispersed carrier is not particularly limited, and known resins can be used. For example, a styrene acrylic resin, a polyester resin, a fluorine resin, a phenol resin, or the like can be used. it can.

  Next, the image forming method of the present invention and the image forming apparatus used therefor will be described with reference to FIG.

In the apparatus system shown in FIG. 12, a developer having cyan toner, a developer having magenta toner, a developer having yellow toner, and black are respectively added to the developers 14-1, 14-2, 14-3, and 14-4. A developer having toner is introduced, and the electrostatic image formed on the photoconductor 11 is developed by a magnetic brush development method or a non-magnetic one-component development method, and each color toner image is formed on the photoconductor 11. The photoreceptor 11 is a photosensitive drum or a photosensitive belt having a photoconductive insulating material layer such as a-Se, CdS, ZnO ₂ , OPC, or a-Si. The photoreceptor 11 is rotated in the direction of the arrow by a driving device (not shown).

  As the photoreceptor 11, an amorphous silicon photosensitive layer or a photoreceptor having an organic photosensitive layer is preferably used. The organic photosensitive layer may be a single layer type in which the photosensitive layer contains a charge generation material and a material having charge transport performance in the same layer, or a function-separated type photosensitive layer comprising the charge transport layer and the charge generation layer as components. It may be. A laminated photosensitive layer having a structure in which a charge generation layer and then a charge transport layer are laminated in this order on a conductive substrate is one preferred example.

  The binder resin for the organic photosensitive layer is particularly a polycarbonate resin, a polyester resin, or an acrylic resin, and has good transferability and cleaning properties, and poor cleaning, toner fusion to the photoreceptor, and filming of external additives are unlikely to occur.

  In the charging process according to the image forming method of the present invention, there are a non-contact method with the photoconductor 11 using a corona charger and a contact type method using a roller or the like. For efficient uniform charging, simplification, and low ozone generation, a contact type as shown in FIG. 12 is preferably used.

  The charging roller 12 is basically composed of a conductive elastic layer 12a that forms an outer periphery with a central core 12b. The charging roller 12 is pressed against the surface of the photoconductor 11 with a pressing force, and is driven to rotate as the photoconductor 11 rotates.

  Preferred process conditions when using a charging roller include a roller contact pressure of 4.9 to 490 N / m (5 to 500 g / cm), and a DC voltage superimposed with an AC voltage. Voltage = 0.5-5 kVpp, AC frequency = 50 Hz-5 kHz, DC voltage = ± 0.2- ± 1.5 kV, and DC voltage = ± 0.2- ± 5 kV when DC voltage is used.

  Other charging means include a method using a charging blade and a method using a conductive brush. These contact charging means are effective in that a high voltage is unnecessary and generation of ozone is reduced. As the charging roller and charging blade material as the contact charging means, conductive rubber is preferable, 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.

  The toner image on the photosensitive member is transferred to the intermediate transfer member 15 to which a voltage (for example, ± 0.1 to ± 5 kV) is applied.

The intermediate transfer member 15 includes a pipe-shaped conductive core 15b and a medium-resistance elastic layer 15a formed on the outer peripheral surface thereof. The core 15b may be a plastic pipe with conductive plating. Medium resistance elastic layer 15a is made of elastic material such as silicone rubber, Teflon (registered trademark) rubber, chloroprene rubber, urethane rubber, EPDM (ethylene propylene diene terpolymer), carbon black, zinc oxide, oxidized It is a solid or foamed meat layer in which conductivity imparting materials such as tin and silicon carbide are mixed and dispersed to adjust the electric resistance value (volume resistivity) to a medium resistance of 10 ⁵ to 10 ¹¹ Ω · cm.

  The intermediate transfer member 15 is disposed in parallel with the photosensitive member 11 and is in contact with the lower surface portion of the photosensitive member 11, and rotates in the counterclockwise direction indicated by an arrow at the same peripheral speed as the photosensitive member 11. The toner image of the first color formed and supported on the surface of the photoconductor 11 passes through the transfer nip where the photoconductor 11 and the intermediate transfer body 15 are in contact with each other, and is formed in the transfer nip area with an applied transfer bias to the intermediate transfer body 15 The intermediate transfer is sequentially performed on the outer surface of the intermediate transfer member 15 by the applied electric field. If necessary, the surface of the intermediate transfer member 15 is cleaned by the removable cleaning unit 110 after the transfer of the toner image onto the transfer material. When the toner image is present on the intermediate transfer member 15, the cleaning unit 110 is separated from the surface of the intermediate transfer member so as not to disturb the toner image.

  The transfer means is disposed in parallel with the intermediate transfer body 15 and brought into contact with the lower surface portion of the intermediate transfer body 15. The transfer means is, for example, a transfer roller 17, and has the same peripheral speed as that of the intermediate transfer body 15. Rotate clockwise as shown. The transfer roller 17 may be disposed so as to be in direct contact with the intermediate transfer member 15, or a belt or the like may be disposed between the intermediate transfer member 15 and the transfer roller 17. The transfer roller 17 is basically composed of a central cored bar 17b and a conductive elastic layer 17a formed on the outer periphery thereof.

  As the intermediate transfer member and the transfer roller used in the present invention, general materials can be used. In the present invention, the voltage applied to the transfer roller can be reduced by setting the volume specific resistance value of the elastic layer of the transfer roller smaller than the volume specific resistance value of the elastic layer of the intermediate transfer member. A toner image can be formed and winding of the transfer material around the intermediate transfer member can be prevented.

  In particular, the volume specific resistance value of the elastic layer of the intermediate transfer member is particularly preferably 10 times or more than the volume specific resistance value of the elastic layer of the transfer roller. The hardness of the intermediate transfer member and the transfer roller is measured according to JIS K-6301. The intermediate transfer member used in the present invention is preferably composed of an elastic layer belonging to a range of 10 to 40 degrees. On the other hand, the hardness of the elastic layer of the transfer roller is harder than the hardness of the elastic layer of the intermediate transfer member. Those having a value of ˜80 degrees are preferable for preventing the transfer material from being wound around the intermediate transfer member. When the hardness of the intermediate transfer member and the transfer roller are reversed, a recess is formed on the transfer roller side, and the transfer material is likely to be wound around the intermediate transfer member.

  The transfer roller 17 is rotated with a difference in speed or peripheral speed from the intermediate transfer body 15. The transfer material 16 is conveyed between the intermediate transfer member 15 and the transfer roller 17 and at the same time, a bias having a polarity opposite to the frictional charge of the toner is applied to the transfer roller 17 from the transfer bias unit. The toner image is transferred to the surface side of the transfer material 16. As the material of the transfer rotator, the same material as that of the charging roller can be used. As a preferable transfer process condition, the contact pressure of the roller is 4.9 to 490 N / m (5 to 500 g / cm). The DC voltage is ± 0.2 to ± 10 kV.

For example, the conductive elastic layer 17b of the transfer roller 17 is made of an elastic body having a volume resistance of about 10 ⁶ to 10 ¹⁰ Ωcm such as a terpolymer (EPDM) such as carbon. A polyurethane or ethylene-propylene-diene system in which a bias conductive material is dispersed by a constant voltage power source is added to the core metal 17a. The bias condition is preferably ± 0.2 to ± 10 kV.

  Subsequently, the transfer material 16 is conveyed to a fixing device 111 having a heating roller incorporating a heating element such as a halogen heater and an elastic pressure roller pressed against the heating roller by a pressing force. By passing between the pressure rollers, the toner image is heated and pressure-fixed on the transfer material. A method of fixing with a heater through a film may be used.

  A preferred fixing method used in the present invention is a so-called contact heating method. In particular, examples of the contact heating method include a heat pressure fixing method, a heat roll fixing method, and a pressure heating fixing method in which fixing is performed by a rotating pressure member including a fixedly arranged heating body.

  FIG. 13 is a cross-sectional view showing an example of a fixing device used in the present invention. The fixing device shown in FIG. 13 includes a heating roller 1000 and a pressure roller 2000 in contact with the heating roller 1000. In FIG. 13, T is a toner image formed on a recording material (also called an image support, which is a typical transfer paper).

  The heating roller 1000 has a coating layer 1200 made of silicone rubber formed on the surface of a core metal 1100 and includes a heating member 1300 made of a linear heater. Furthermore, it is preferable that the surface is coated with tetrafluoroethylene, polytetrafluoroethylene-perfluoroalkoxy vinyl ether copolymers, or the like, or with a tube of these materials. The thickness of this coating is 10 to 500 μm, preferably 20 to 200 μm.

  The core metal 1100 is made of a metal or an alloy thereof, and has an inner diameter of 10 to 70 mm. Although it does not specifically limit as a metal core, For example, metals, such as iron, aluminum, copper, or these alloys can be mention | raise | lifted.

  The thickness of the core metal 1100 is preferably 0.1 to 2 mm, and is determined in consideration of the balance between the energy saving requirement (thinning) and the strength (depending on the constituent materials). For example, in order to maintain the same strength as a core metal made of iron of 0.57 mm with a core metal made of aluminum, it is preferable to adjust the thickness to 0.8 mm.

  Examples of the silicone rubber constituting the coating layer 1200 include LTV, RTV, and HTV silicone rubbers or sponges.

  The thickness of the coating layer 1200 is preferably adjusted to 0.1 to 30 mm, more preferably 0.1 to 20 mm. If the thickness is less than 0.1 mm, the fixing nip cannot be increased, and the effect of soft fixing is not sufficient.

  As the heating member 1300, a halogen heater can be preferably used. In addition, as shown in FIG. 14, it is good also as a structure which can include a some heating member and can change a heat distribution area | region according to the size (width) of the paper to pass through, as shown in FIG. . A heating roller 1500 shown in FIG. 14 is provided with a halogen heater 1600A for heating the central region of the roller surface, a halogen heater 1600B for heating the end region of the roller surface, and a halogen heater 1600C. .

  According to the heating roller 1500 as shown in FIG. 14, when a narrow paper is passed, only the halogen heater 1600A is energized, and when a wide paper is passed, a halogen heater 1600B and a halogen heater 1600C are further provided. Also energize.

  Returning to FIG. 13, the pressure roller 2000 is formed by forming a coating layer 2200 made of rubber on the surface of the core metal 2100. The rubber of the coating layer is not particularly limited, and urethane rubber, silicone rubber, and the like can be used, but heat resistant silicone rubber is more preferable. As the silicone rubber, the same material as the coating layer 12 can be used.

  Although it does not specifically limit as a material which comprises the metal core 2100, Metals, such as aluminum, iron, copper, or those alloys can be mention | raise | lifted.

  The thickness of the coating layer 2200 is 0.1 to 30 mm, preferably 0.1 to 20 mm. If the thickness is less than 1 mm, the fixing nip cannot be increased, and the effect of soft fixing is not sufficient.

  The Asker C hardness of the silicone rubber or rubber constituting the coating layers 1200 and 2200 is preferably less than 70 °, more preferably less than 60 °, and silicone sponge rubber is preferred.

  The contact load (total load) between the heating roller 1000 and the pressure roller 2000 is usually 40 to 350 N, preferably 50 to 300 N, and more preferably 50 to 250 N. This contact load is defined in consideration of the strength of the heating roller 1000 (the thickness of the core metal 1100). For example, in a heating roller having a core metal made of 0.3 mm iron, the contact load should be 250 N or less. Is preferred.

From the viewpoint of offset resistance and fixability, the nip width is preferably 4 to 10 mm, and the surface pressure of the nip is preferably 0.6 to 1.5 × 10 ⁵ Pa.

  If an example of the fixing conditions by the fixing device shown in FIG. 13 is shown, the fixing temperature (surface temperature of the heating roller 1000) is 150 to 210 ° C., and the fixing linear velocity is 80 to 640 mm / sec.

  The fixing device used in the present invention may be provided with a fixing unit cleaning mechanism as required. In this case, as a method of supplying silicone oil to the upper roller of the fixing unit, a method of supplying and cleaning with a pad, roller, web or the like impregnated with silicone oil can be used.

  As the silicone oil, one having high heat resistance is used, and polydimethyl silicone, polyphenylmethyl silicone, polydiphenyl silicone and the like are used. Since a low-viscosity thing will have a large outflow at the time of use, those having a viscosity at 20 ° C. of 1 to 100 Pa · s are preferably used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.

(Toner Production Example 1: Example of emulsion polymerization association method)
0.90 kg of sodium n-dodecyl sulfate and 10.0 liters of pure water were added and dissolved by stirring. To this solution, 1.20 kg of Legal 330R (Cabot carbon black) was gradually added and stirred well for 1 hour, followed by continuous dispersion for 20 hours using a sand grinder (medium disperser). This is referred to as “colorant dispersion 1”. A solution composed of 0.055 kg of sodium dodecylbenzenesulfonate and 4.0 liters of ion-exchanged water is referred to as “anionic surfactant solution A”.

  A solution composed of 0.014 kg of nonylphenol polyethylene oxide 10 mol adduct and 4.0 liters of ion-exchanged water is referred to as “nonionic surfactant solution B”. A solution obtained by dissolving 238 g of potassium persulfate in 12.0 liters of ion-exchanged water is referred to as “initiator solution C”.

  A GL (glass lining) reaction kettle with a volume of 100 liters equipped with a temperature sensor, a cooling pipe, and a nitrogen introducing device was added to a WAX emulsion (a polypropylene emulsion having a number average molecular weight of 3000: number average primary particle size = 120 nm / solid content concentration = 29. 9%) 3.41 kg, the total amount of “anionic surfactant solution A” and the total amount of “nonionic surfactant solution B” were added, and stirring was started. Subsequently, 44.0 liters of ion exchange water was added.

  Heating was started and when the liquid temperature reached 75 ° C., the entire amount of “Initiator Solution C” was added dropwise. Thereafter, while controlling the liquid temperature at 75 ° C. ± 1 ° C., a solution consisting of 12.1 kg of styrene, 2.70 kg of n-butyl acrylate, 1.14 kg of methacrylic acid, and 550 g of t-dodecyl mercaptan was added dropwise. . After completion of the dropwise addition, the liquid temperature was raised to 80 ° C. ± 1 ° C. and stirring was performed for 6 hours. Next, the liquid temperature was cooled to 40 ° C. or less, stirring was stopped, and filtration was performed with a pole filter to obtain a latex. This is designated as “Latex-A”.

  The glass transition temperature of the resin particles in Latex-A was 58 ° C., the softening point was 119 ° C., the molecular weight distribution was weight average molecular weight = 13,000, and the weight average particle size was 115 nm.

  A solution prepared by dissolving 0.055 kg of sodium dodecylbenzenesulfonate in 4.0 liters of ion-exchanged pure water is referred to as “anionic surfactant solution D”.

  Further, a solution obtained by dissolving 0.014 kg of nonylphenol polyethylene oxide 10 mol adduct in 4.0 liters of ion-exchanged water is referred to as “nonionic surfactant solution E”.

  A solution obtained by dissolving 200 g of potassium persulfate (manufactured by Kanto Chemical Co., Ltd.) in 12.0 liters of ion-exchanged water is referred to as “initiator solution F”.

  A WAX emulsion (a polypropylene emulsion with a number average molecular weight of 3000: number average primary particle size = 120 nm / solid content concentration of 29.9%) is added to a 100 liter GL reaction kettle equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device and a comb baffle. 3.41 kg, the total amount of “anionic surfactant solution D” and the total amount of “nonionic surfactant solution E” were added, and stirring was started.

  Next, 44.0 liters of ion exchange water was added. Heating was started, and when the liquid temperature reached 70 ° C., “initiator solution F” was added. Subsequently, a solution prepared by previously mixing 11.0 kg of styrene, 4.00 kg of n-butyl acrylate, 1.04 kg of methacrylic acid, and 9.0 g of t-dodecyl mercaptan was dropped. After completion of the dropwise addition, the liquid temperature was controlled at 72 ° C. ± 2 ° C., and the mixture was heated and stirred for 6 hours. Furthermore, the liquid temperature was raised to 80 ° C. ± 2 ° C., and the mixture was heated and stirred for 12 hours. The liquid temperature was cooled to 40 ° C. or lower, and stirring was stopped. The filtrate is filtered through a pole filter, and this filtrate is designated as “Latex-B”.

  The glass transition temperature of the resin particles in Latex-B was 59 ° C., the softening point was 133 ° C., the molecular weight distribution was weight average molecular weight = 24,000, and the weight average particle size was 110 nm.

  A solution obtained by dissolving 5.36 kg of sodium chloride as a salting-out agent in 20.0 liters of ion-exchanged water is referred to as “sodium chloride solution G”.

  A solution obtained by dissolving 1.00 g of a fluorine-based nonionic surfactant in 1.00 liter of ion-exchanged water is referred to as “nonionic surfactant solution H”.

  A 100-liter SUS reaction kettle equipped with a temperature sensor, a cooling pipe, a nitrogen introduction device, a particle size and shape monitoring device (reaction device having the configuration shown in FIG. 9, crossing angle α is 25 °) was prepared as described above. Latex-A = 20.0 kg, latex-B = 5.2 kg, colorant dispersion 1 = 0.4 kg and ion-exchanged water 20.0 kg were added and stirred. Next, the mixture was heated to 40 ° C., and sodium chloride solution G, 6.00 kg of isopropanol (manufactured by Kanto Chemical Co., Inc.) and nonionic surfactant solution H were added in this order. Then, after standing for 10 minutes, the temperature rise was started, the temperature was raised to a liquid temperature of 85 ° C. in 60 minutes, and the particles were heated and stirred at 85 ± 2 ° C. for 0.5 to 3 hours while being salted out / fused. Diameter growth. Next, 2.1 liters of pure water was added to stop the particle size growth.

  The fused particle dispersion prepared above was placed in a 5-liter reaction vessel (reaction apparatus having the configuration shown in FIG. 9, crossing angle α is 20 °) equipped with a temperature sensor, a cooling pipe, and a particle size and shape monitoring device. 5.0 kg was added, and the shape was controlled by heating and stirring for 0.5 to 15 hours at a liquid temperature of 85 ° C. ± 2 ° C. Then, it cooled to 40 degrees C or less, and stopped stirring. Next, using a centrifugal separator, classification is performed in the liquid by a centrifugal sedimentation method, followed by filtration through a sieve having an opening of 45 μm, and this filtrate is used as an association liquid. Subsequently, wet cake-like non-spherical particles were collected by filtration from the associating liquid using Nutsche. Thereafter, it was washed with ion exchange water. The non-spherical particles were dried at a suction air temperature of 60 ° C. using a flash jet dryer and then dried at a temperature of 60 ° C. using a fluidized bed dryer. To 100 parts by mass of the obtained colored particles, 1 part by mass of silica fine particles was externally added and mixed with a Henschel mixer to obtain a black toner by an emulsion polymerization association method.

  In the monitoring of the salting-out / fusion stage and the shape control process, by controlling the number of revolutions of stirring and the heating time, the coefficient of variation of the shape and the shape factor is controlled, and further the particle size and particle size distribution by subclassification in the liquid. Were arbitrarily adjusted to obtain black toners (Bk toners) 1 to 5 composed of toner particles having specific shape characteristics and particle size distribution characteristics.

(Toner production example 2: Example of emulsion polymerization association method)
In Toner Production Example 1, the colorant is C.I. I. Yellow toners (Y toners) 1 to 5 having specific shape characteristics and particle size distribution characteristics were obtained in the same manner except that 1.05 kg of Pigment Yellow 180 was used.

(Toner production example 3: Example of emulsion polymerization association method)
Toner having specific shape characteristics and particle size distribution characteristics in the same manner as in Toner Production Example 1 except that 1.20 kg of quinacridone magenta pigment (CI Pigment Red 122) was used instead of carbon black as a colorant. Magenta toners (M toners) 1 to 5 comprising particles were obtained.

(Toner Production Example 4: Example of Emulsion Polymerization Association Method)
In Toner Production Example 1, specific shape characteristics and particle size distribution characteristics were similarly obtained except that 0.60 kg of phthalocyanine-based cyan pigment (CI Pigment Blue 15: 3) was used instead of carbon black as a colorant. Cyan toners (C toners) 1 to 5 comprising toner particles having the above were obtained.

(Toner Production Example 5: Example of suspension polymerization method)
Styrene = 165 g, n-butyl acrylate = 35 g, carbon black = 10 g, di-t-butyl salicylic acid metal compound = 2 g, styrene-methacrylic acid copolymer = 8 g, paraffin wax (mp = 70 ° C.) = 20 g at 60 ° C. And uniformly dissolved and dispersed at 12000 rpm with a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). To this was added 2,2′-azobis (2,4-valeronitrile) = 10 g as a polymerization initiator and dissolved therein to prepare a polymerizable monomer composition. Next, 450 g of 0.1 M sodium phosphate aqueous solution was added to 710 g of ion exchange water, and 68 g of 1.0 M calcium chloride was gradually added while stirring at 13,000 rpm with a TK homomixer to prepare a suspension in which tricalcium phosphate was dispersed. did. The polymerizable monomer composition was added to this suspension, and stirred at 10,000 rpm for 20 minutes with a TK homomixer to granulate the polymerizable monomer composition. Then, the reaction apparatus (crossing angle (alpha) is 45 degrees) of the structure as shown in FIG. 2 was used, and it was made to react for 5 to 15 hours at 75-95 degreeC. The tricalcium phosphate was dissolved and removed with hydrochloric acid, and then classified in the liquid by centrifugal sedimentation using a centrifugal separator, and then filtered, washed and dried. To 100 parts by mass of the obtained colored particles, 1 part by mass of silica fine particles was externally added and mixed with a Henschel mixer to obtain a toner by a suspension polymerization method.

  Monitoring is performed during the polymerization, and the variation coefficient of the shape and shape factor is controlled by controlling the liquid temperature, the number of rotations of stirring, and the heating time. Furthermore, the variation coefficient of the particle size and particle size distribution is arbitrarily determined by classification in the liquid. Thus, black toners (Bk toners) 6 to 8 made of toner particles having specific shape characteristics and particle size distribution characteristics were obtained.

(Toner Production Example 6: Example of suspension polymerization method)
In Toner Production Example 5, the colorant is C.I. I. Yellow toners (Y toners) 6 to 8 having specific shape characteristics and particle size distribution characteristics were obtained in the same manner except that 1.05 kg of Pigment Yellow 180 was used.

(Toner Production Example 7: Example of suspension polymerization method)
A toner having specific shape characteristics and particle size distribution characteristics in the same manner as in toner production example 5 except that 1.20 kg of quinacridone magenta pigment (CI Pigment Red 122) was used instead of carbon black as a colorant. Magenta toner (M toner) 6 to 8 comprising particles was obtained.

(Toner Production Example 8: Example of suspension polymerization method)
In Toner Production Example 5, specific shape characteristics and particle size distribution characteristics were similarly obtained except that 0.60 kg of phthalocyanine-based cyan pigment (CI Pigment Blue 15: 3) was used instead of carbon black as a colorant. Cyan toners (C toners) 6 to 8 composed of toner particles having toner particles were obtained.

(Toner Production Example 9: Example of suspension polymerization method)
In Toner Production Example 5, the reaction apparatus having the configuration shown in FIG. 9 (crossing angle α is 15 °) was used, and the classification in liquid using a centrifuge was not performed. Thus, a black toner (Bk toner) 9 made of toner particles having specific shape characteristics and particle size distribution characteristics was obtained.

(Toner Production Example 10: Example of suspension polymerization method)
In Toner Production Example 9, the colorant is C.I. I. A yellow toner (Y toner) 9 having specific shape characteristics and particle size distribution characteristics was obtained in the same manner except that 1.05 kg of Pigment Yellow 180 was used.

(Toner Production Example 11: Example of Suspension Polymerization Method)
A toner having specific shape characteristics and particle size distribution characteristics in the same manner as in Toner Production Example 9, except that 1.20 kg of quinacridone magenta pigment (CI Pigment Red 122) was used instead of carbon black as the colorant. A magenta toner (M toner) 9 composed of particles was obtained.

(Toner Production Example 12: Example of suspension polymerization method)
In Toner Production Example 9, specific shape characteristics and particle size distribution characteristics were similarly obtained except that 0.60 kg of phthalocyanine cyan pigment (CI Pigment Blue 15: 3) was used instead of carbon black as a colorant. Cyan toner (C toner) 9 made of toner particles having the toner particles was obtained.

(Toner Production Example 13: Example of grinding method)
A toner raw material consisting of 100 kg of styrene-nbutyl acrylate copolymer resin, 10 kg of carbon black, and 4 parts by mass of polypropylene is premixed with a Henschel mixer, melt kneaded with a twin screw extruder, and coarsely pulverized with a hammer mill. The resulting powder was pulverized by a jet pulverizer, and the resulting powder was dispersed in a hot air stream of a spray dryer (at 200 to 300 ° C. for 0.05 seconds) to obtain particles whose shape was adjusted. These particles were repeatedly classified with an air classifier until the desired particle size distribution was obtained. To 100 parts by mass of the obtained colored particles, 1 part by mass of silica fine particles was externally added and mixed with a Henschel mixer to obtain a toner by a pulverization method.

  In this way, the black toner (Bk toner) 10 composed of toner particles having specific shape characteristics and particle size distribution characteristics, in which the shape and shape coefficient variation coefficients are controlled and the particle diameter and particle size distribution variation coefficients are adjusted. ~ 11 was obtained.

(Toner Production Example 14: Example of grinding method)
In Toner Production Example 13, the colorant is C.I. I. Yellow toner (Y toner) 10 to 11 having specific shape characteristics and particle size distribution characteristics was obtained in the same manner except that 1.05 kg of Pigment Yellow 180 was used.

(Toner Production Example 15: Example of grinding method)
Toner having specific shape characteristics and particle size distribution characteristics in the same manner as in Toner Production Example 13 except that 1.20 kg of quinacridone magenta pigment (CI Pigment Red 122) was used instead of carbon black as a colorant. Magenta toners (M toners) 10 to 11 made of particles were obtained.

(Toner Production Example 16: Example of grinding method)
In Toner Production Example 13, specific shape characteristics and particle size distribution characteristics were similarly obtained except that 0.60 kg of a phthalocyanine cyan pigment (CI Pigment Blue 15: 3) was used instead of carbon black as a colorant. Cyan toners (C toners) 10 to 11 made of toner particles having the above were obtained.

  The shape characteristics and the like of the toner described above are shown in Table 1 below.

  Each of the above toners was mixed with a ferrite carrier having a volume average particle diameter of 60 μm coated with a silicone resin to prepare a developer having a toner concentration of 6%. These are designated as “Developer 1” to “Developer 15” corresponding to the toner.

  Table 2 shows properties of the obtained developers 1 to 15.

  The developer prepared here was used, and the digital color copying machine shown in FIG. 12 was used, except that the fixing device was configured using a pressure contact type heat fixing device as shown in FIG. The specific configuration of the heat fixing device was set as follows.

  An aluminum alloy with an inner diameter of 30 mm and a total width of 310 mm, coated with sponge-like silicone rubber (Asker C hardness = 30: thickness 8 mm) and having a heater built in the center, with a thickness of 1.0 mm, is a heating roller (upper roller) And a pressure roller (lower roller) having an iron cored bar with an inner diameter of 40 mm and an inner diameter of 40 mm, which is similarly composed of a sponge-like silicone rubber (Asker C hardness = 30: thickness 2 mm). is doing. The nip width was 5.8 mm. Using this fixing device, the linear velocity of printing was set to 180 mm / sec. The nip width is 6.6 mm. The surface of the heating roller is covered with a PFA tube (50 μm).

  Further, a web-type supply system impregnated with polydiphenyl silicone (having a viscosity of 10 Pa · s at 20 ° C.) was used as a cleaning mechanism of the fixing device.

  The fixing temperature was controlled by the surface temperature of the upper roll, and was set to a set temperature of 175 ° C. The amount of silicone oil applied was 0.6 mg / A4.

  Under the above conditions, 100,000 sheets of images were formed, and color differences were evaluated for the first image and the 100,000th image. The color difference was evaluated by the following method.

  That is, the color of the solid image portion of the secondary color (red, blue, green) in each of the first formed image and the 100,000th formed image is measured by “Macbeth Color-Eye 7000”, and CMC (2: 1 ) The color difference was calculated using the color difference formula.

  If the color difference obtained by the CMC (2: 1) color difference formula is 5 or less, it can be said that the change in the color of the formed image is acceptable.

  Further, in order to evaluate the image arrangement at the time of transfer and fixing, the resolutions of line drawings in which four colors of toner are composed of dots are compared. The resolution itself was “lines / mm”, and whether or not the line could be identified with a magnifier of 10 times was determined from the horizontal line (the horizontal direction with respect to the developing direction).

  The obtained results are shown in Table 3.

  From Table 3, the sample of the present invention has little color difference even at the initial stage and the 100,000th sheet, and the fine line reproducibility is good at the initial stage and the 100,000th sheet. Obviously, the secondary color difference is small.

It is explanatory drawing which shows the reactor with the structure of a stirring blade. It is a perspective view which shows an example of the reaction apparatus provided with the stirring blade which can be used preferably. It is sectional drawing of the reaction apparatus shown in FIG. It is a perspective view which shows the specific example of the reaction apparatus provided with the stirring blade which can be used preferably. It is a perspective view which shows the specific example of the reaction apparatus provided with the stirring blade which can be used preferably. It is a perspective view which shows the specific example of the reaction apparatus provided with the stirring blade which can be used preferably. It is a perspective view which shows the specific example of the reaction apparatus provided with the stirring blade which can be used preferably. It is a perspective view which shows the specific example of the reaction apparatus provided with the stirring blade which can be used preferably. It is a perspective view which shows an example of the reaction apparatus used when forming a laminar flow. It is the schematic which shows the specific example of the shape of a stirring blade. (A) is explanatory drawing which shows the projection image of a toner particle without an angle | corner, (b) and (c) are explanatory drawings which show the projection image of a toner particle with an angle | corner, respectively. It is explanatory drawing which shows an example of the image development apparatus by a non-contact image development system. FIG. 3 is a cross-sectional view illustrating an example of a fixing device used in the present invention. FIG. 3 is an explanatory diagram showing an example of a heat distribution pattern of a heating roller that constitutes a fixing device used in the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat exchange jacket 2 Stirrer tank 3 Rotating shaft 4 Stirrer blades 40, 41, 42, 43, 44, 45, 46 Lower stirrer blades 411, 422, 431, 441 Bending parts 421 Slits 423, 432, 442 Fins 50, 51, 52, 53, 54, 56, 65 Stirring blades 511 Fin 541 located in the upper stage 55 Stirring blades 5a, 5b, 5c, 5d located in the middle stage 6b, 6c, 6d Middle hole part 7 Upper material inlet 8 Lower material inlet 9 Turbulent flow forming member α Crossing angle 13 Exposure direction 18 Blade 19 Cleaning device

Claims (5)

A step of forming a latent image on the latent image carrier, a step of developing the formed latent image with a developer containing toner, a step of transferring the formed toner image onto an intermediate transfer member, and the transferred toner An electrostatic charge image developing toner used in an image forming method including a step of transferring an image onto an image forming support and a step of fixing a toner image formed on the image forming support. Toner particles containing a colorant and having no corners (in a circle C having a radius (L / 10), where the major axis of the toner particles T is L), one point inside the peripheral line of the toner particles T The ratio of the toner particles in which the circle C does not substantially protrude outside the toner T when the inner surface is rolled while being in contact with the toner) is 50% by number or more, and the number variation coefficient in the number particle size distribution is 27. % is formed from the toner particles is less, and, Serial electrostatic image developing toner, wherein the proportion of toner particles in the range of shape factor of 1.2 to 1.6, which is defined is 65 number% or more by formula.
Shape factor = ((maximum diameter / 2) ² × π) / projection area 2. The electrostatic image developing toner according to claim 1, wherein the toner particles have a number average particle diameter of 3 to 8 [mu] m. 3. The electrostatic image developing toner according to claim 1, wherein the toner is obtained by polymerizing a polymerizable monomer in an aqueous medium. 4. The electrostatic image developing toner according to claim 1, wherein the toner is obtained by associating resin particles in an aqueous medium. A process of forming a latent image A corresponding to a yellow image on a latent image carrier using the electrostatic charge image developing toner according to claim 1, wherein the latent image A includes yellow toner. A step of developing with a developer, a step of transferring the formed yellow toner image onto an intermediate transfer member, a step of forming a latent image B corresponding to a magenta image on the latent image carrier, and the latent image B to magenta toner A step of developing with a developer containing the toner, a step of transferring the formed magenta toner image onto the intermediate transfer member, a step of forming a latent image C corresponding to a cyan image on the latent image carrier, and the latent image C. Developing with a developer containing cyan toner, transferring the formed cyan toner image onto the intermediate transfer member, forming a latent image D corresponding to a black image on the latent image carrier, Develop latent image D with developer containing black toner A step of transferring the formed black toner image onto the intermediate transfer member, and the yellow toner image, the magenta toner image, the cyan toner image and the black toner image formed on the intermediate transfer member, In each of the image forming methods including the step of transferring onto the image forming support and the step of fixing the toner image formed on the image forming support, the shape factor (Ky) and variation of the shape factor of the yellow toner Coefficient (Kσy), number average particle size (Dy), number variation coefficient (Dσy) in the number particle size distribution, shape factor (Km) of the magenta toner, variation coefficient of shape factor (Kσm), number average particle size ( Dm), the number variation coefficient (Dσm) in the number particle size distribution, the shape factor (Kc) of the cyan toner, the variation coefficient of the shape factor (Kσc), the number average particle size (Dc), and the number in the number particle size distribution. The relationship among the variation coefficient (Dσc), the shape factor (Kb) of the black toner, the variation coefficient of the shape factor (Kσb), the number average particle diameter (Db), and the number variation coefficient (Dσb) in the number particle size distribution is as follows ( An image forming method represented by Formula 1) to Formula 4:
  (Formula 1)
      0 ≦ ((maximum value of Ky, Km, Kc, Kb) − (minimum value of Ky, Km, Kc, Kb)) / (maximum value of Ky, Km, Kc, Kb) ≦ 0.2
  (Formula 2)
      0 ≦ ((maximum value of Kσy to Kσb) − (minimum value of Kσy to Kσb)) / (maximum value of Kσy to Kσb) ≦ 0.30
  (Formula 3)
      0 ≦ ((maximum value from Dy to Db) − (minimum value from Dy to Db)) / (maximum value from Dy to Db) ≦ 0.15
  (Formula 4)
      0 ≦ (maximum value from Dσy to Dσb) − (minimum value from Dσy to Dσb) / (maximum value from Dσy to Dσb) ≦ 0.25

Images