JP2006308640A - Method for manufacturing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing toner by which surface modified toner particles of a small particle size showing a sharp particle size distribution with a little fraction of fine powder and having a high circularity can be stably obtained with a high yield. <P>SOLUTION: The method for manufacturing a toner includes the steps of: melting and kneading a composition containing at least a binder resin and a colorant; cooling the obtained kneaded material; finely pulverizing the cooled solidified material; and modifying the surface of the obtained pulverized material. The step of surface modification is carried out by using a batch-type surface modifying apparatus having at least a dispersion rotor 32 for the surface modification by use of mechanical impact force and a liner 34 as a fixed body disposed in the periphery of the dispersion rotor at a specified distance from the rotor. The dispersion rotor has a surface modifying member having a dispersion hammer 33 on the upper face of the rotor; a plurality of dispersion hammers are laid on the upper face of the dispersion rotor; and each dispersion hammer has a plurality of projections and recesses on the surface of the surface modifying part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a toner used in an image forming method such as an electrophotographic method, an electrostatic recording method, an electrostatic printing method, or a toner jet recording method.

  In an image forming method such as electrophotography, a toner for developing an electrostatic image is used. The toner production method is roughly classified into a pulverization method and a polymerization method, and a simple and popular production method includes a pulverization method. As a general manufacturing method thereof, a binder resin for fixing to a transfer material, a colorant for giving a color as a toner is used, and a charge control agent for imparting electric charges to particles as necessary, Add and mix magnetic materials for imparting transportability etc. to the toner itself, additives such as mold release agents, fluidity imparting agents, etc., melt knead, cool and solidify, and then refine the kneaded material by grinding means If necessary, the toner is classified into a desired particle size distribution, or further added with a fluidizing agent or the like to provide a toner for image formation. In the case of a toner used in the two-component development method, various magnetic carriers and the above toner are mixed and then used for image formation.

  Various pulverizers are used as the pulverizing means, and a jet airflow pulverizer using a jet airflow as shown in FIG. 9, particularly a collision airflow pulverizer is often used. A collision type airflow crusher conveys powder raw material with a high-pressure gas such as a jet stream, injects it from the outlet of the acceleration tube, and collides with the collision surface of the collision member provided facing the opening surface of the outlet of the acceleration tube. The powder raw material is pulverized by the impact force.

  For example, in the collision-type airflow crusher shown in FIG. 9, a collision member 436 is provided facing the acceleration tube outlet to which the high-pressure gas supply nozzle 435 is connected, and is communicated with the middle of the acceleration tube by the high-pressure gas supplied to the acceleration tube. The powder raw material is sucked into the accelerating tube from the powder raw material supply port, and the powder raw material is jetted together with the high-pressure gas so as to collide with the collision surface of the collision member 436 and pulverized by the impact. It is discharging more.

  However, the above collision type airflow pulverizer has a configuration in which the powder raw material is jetted together with the high-pressure gas, collides with the collision surface of the collision member, and is pulverized by the impact. Requires a lot of air. Therefore, power consumption is extremely large, and there is a problem in terms of energy cost. Particularly in recent years, there has been a demand for energy saving of devices in order to cope with environmental problems.

  On the other hand, mechanical pulverizers are used as pulverizers that are energetically more efficient than jet airflow pulverizers (see, for example, Patent Document 1, Document 2, and Document 3). This mechanical pulverizer pulverizes by introducing a powder raw material into an annular space formed between a rotor rotating at high speed and a stator arranged around the rotor. According to the mechanical pulverizer, finer pulverization can be achieved with much lower energy consumption than a jet airflow pulverizer, and since it is less excessively pulverized, the generation of fine powder is reduced and the yield can be improved.

  Focusing on the shape of the toner particles pulverized by these pulverizers, the toner particles pulverized by the jet airflow pulverizer have an irregular and angular shape, and the toner particles pulverized by the mechanical pulverizer have corners. It is known that the shape is round and round. This is thought to be due to the difference in the grinding process. That is, in the pulverization method using a jet stream, most of the pulverization is performed by collision with the collision member. However, in the mechanical pulverizer, most of the pulverization is performed on the walls of the rotor and the stator that rotate at high speed. This is because the particles collide. In mechanical pulverization, heat is generated by pulverization, and the shape of the pulverized toner particles is considered to be rounded due to the effect of thermal spheroidization.

  For this reason, the toner particles pulverized by the mechanical pulverizer have a smaller specific surface area than the toner particles pulverized by the jet airflow pulverizer, so that the fluidity is good and the voids are small. It has the advantage of being excellent and having only a small amount of external additive added. In addition, there are merits in quality such as excellent chargeability and transferability. That is, according to the mechanical pulverizer, it is possible to produce toner of excellent quality with energy saving and high yield.

  However, in recent years, with higher image quality and higher definition of copiers and printers, the performance required of toner as a developer has become more severe, the particle size of the toner is small, and the particle size distribution of the toner is coarse. There is a growing demand for a sharp product that does not contain a small amount of fine powder.

  In addition, in order to achieve cleaner-less and waste toner reduction, improvement in toner transferability is required, and further spheroidization to improve the surface shape of toner particles has been required. Yes.

  For example, as a method for manufacturing the toner described above, a toner that has been spheroidized by a mechanical impact force has been proposed (see, for example, Patent Document 4). In addition to the method using the mechanical impact force described above, a method for melting the surface with hot air, a method using heat, and the like are known as methods for making the toner shape spherical (see, for example, Patent Document 5). ).

  However, in the method using a mechanical impact force, excessive pulverization is likely to occur during spheroidization, and particularly in the case of toner, the toner is pulverized due to the impact associated with spheronization, resulting in an increase in fine powder. Yes, it is not preferable in terms of toner productivity and quality. In addition, the toner has a problem that the surface composition changes due to heat. In particular, since the presence state of the wax component added as a release agent changes, the method of melting the surface by heat may not be preferable in terms of toner quality.

  Thus, since the toner requires many different properties, the properties of the toner are often influenced by the method of producing the toner in addition to the raw materials used. Particularly in recent years, it has been required to efficiently and stably produce toner surface-modified particles having a small particle size, a sharp particle size distribution with few fine powders, and a high degree of circularity.

JP 59-24855 A JP 59-105853 A Japanese Patent Publication No. 3-15489 Japanese Patent Laid-Open No. 9-85741 JP 2000-29241 A

  The object of the present invention is to eliminate such problems, and to produce toner surface modified particles having a small particle size, a sharp particle size distribution with few fine powders, and a high degree of circularity, in a high yield, An object of the present invention is to provide a toner production method that can be stably obtained.

  A further object of the present invention is to provide a toner production method for obtaining a long-life toner having good developability, transferability, cleaning property, and stable chargeability.

The present invention includes a kneading step of melt-kneading a composition containing at least a binder resin and a colorant, a cooling step of cooling the obtained kneaded product, a step of pulverizing the cooled solidified product to obtain a finely pulverized product, and A step of performing a surface modification step for modifying the surface of the obtained finely pulverized product to obtain toner particles,
The step of performing the surface modification step to obtain toner particles is performed using a batch type surface modification device,
The surface modification apparatus has at least a dispersion rotor for performing a surface modification treatment using a mechanical impact force, and a liner that is a fixed body arranged at a constant interval on the outer periphery of the dispersion rotor. And
The dispersion rotor includes a surface modifying member having a dispersion hammer on an upper surface portion thereof,
A plurality of the dispersion hammers are provided on the upper surface of the dispersion rotor, and the dispersion hammer is provided with a plurality of irregularities on the surface of the surface modification processing unit. .

As a result of intensive studies to solve the above-described problems of the prior art, the present inventor has focused on the shape of the surface modifying member in the surface modifying apparatus for performing surface modification. That is, a composition containing at least a binder resin and a colorant is melt-kneaded, the obtained kneaded product is cooled, the cooled solidified product is finely pulverized to obtain a finely pulverized product, and the obtained finely pulverized product is obtained. In surface modification equipment for surface modification,
(1) The surface modification device includes a dispersion rotor for performing a surface modification treatment using mechanical impact force, and a liner that is a fixed body arranged at a constant interval on the outer periphery of the dispersion rotor. Having at least
(2) The dispersion rotor includes a surface modifying member having a dispersion hammer on an upper surface portion thereof,
(3) A plurality of the dispersion hammers are installed on the top surface of the dispersion rotor, and the dispersion hammer is provided with a plurality of irregularities on the surface of the surface modification treatment part.
(4) The finely pulverized product (= surface modified particles) is dispersed by the dispersion hammer, and the surface of the dispersion hammer surface treatment portion (= the portion where a plurality of irregularities are provided on the surface) and the liner By repeating the surface modification process using mechanical impact force for a certain period of time at a minimum interval of
(5) Toner particles that are surface-modified particles having a high surface modification degree = sphericity degree, in which fine powder having a small particle diameter and not more than a predetermined particle diameter is removed, can be obtained in high yield. As a result, the present invention has been reached.

  According to the present invention, a surface having at least a dispersion rotor for performing surface modification treatment using mechanical impact force, and a liner that is a fixed body arranged at a constant interval on the outer periphery of the dispersion rotor. In the reforming apparatus, the dispersion rotor includes a surface modification member having a dispersion hammer on an upper surface portion thereof, and a plurality of the dispersion hammers are installed on the upper surface portion of the dispersion rotor. A plurality of irregularities are provided on the surface of the surface modification treatment part, and the finely pulverized product (= surface-modified particles) is dispersed by the dispersion hammer, and the surface of the dispersion hammer surface treatment part (= a plurality of surfaces on the surface). Fine particles having a small particle size and not more than a predetermined particle size by repeating the surface modification treatment using a mechanical impact force for a certain period of time at a minimum distance between the liner) and the liner. Body removed The, the toner particles having a high surface-modifying particles circularity can be obtained with good yield.

  Furthermore, according to the present invention, toner surface modified particles having a small particle size, a sharp particle size distribution with few fine powders, and a high degree of circularity can be stably obtained with high yield. Provides a toner production method for obtaining a long-life toner having good developability, transferability and cleaning properties, and stable chargeability.

  Hereinafter, the present invention will be described in more detail with reference to preferred embodiments.

  First, the surface modification means used in the present invention will be described in more detail using schematic diagrams.

  The batch type surface reforming apparatus shown in FIG. 1 includes a cylindrical main body casing 30, a top plate 43 installed so as to be openable and closable at the upper part of the main body casing; a fine powder discharge section 44 having a fine powder discharge casing and a fine powder discharge pipe; Cooling jacket 31 through which cooling water or antifreeze liquid can be passed; as a surface modification means, a plurality of dispersion hammers 33 are provided on the upper surface of the main body casing 30 and attached to the central rotating shaft, and are fast in a predetermined direction. Dispersing rotor 32 that is a rotating disk-shaped rotating body; liner 34 that is fixedly arranged around the dispersing rotor 32 at a constant interval and that has a large number of grooves on the surface facing the dispersing rotor 32; Classification rotor 35 for continuously removing fine powder and ultrafine powder having a predetermined particle size or less in the pulverized product; cold air inlet 46 for introducing cold air into the main body casing 30 An input pipe having a raw material input port 37 and a raw material supply port 39 formed on the side surface of the main body casing 30 for introducing finely pulverized material (raw material); discharging toner particles after the surface modification treatment to the outside of the main body casing 30 A product discharge pipe having a product discharge port 40 and a product discharge port 42 for opening and closing, and an openable raw material supply installed between the raw material input port 37 and the raw material supply port 39 so that the surface modification time can be freely adjusted Valve 38; and a product discharge valve 41 installed between the product discharge port 40 and the product extraction port 42.

  The surface of the liner 34 preferably has a groove as shown in FIGS. 6A and 6B in order to efficiently modify the surface of the toner particles.

  As shown in FIGS. 3A and 3B, the number of the dispersion hammers 33 is preferably an even number in consideration of the rotational balance.

  The classification rotor 35 shown in FIGS. 1, 2 and 7 is preferably rotated in the same direction as the rotation direction of the dispersion rotor 32 in order to increase the efficiency of classification and the efficiency of surface modification of toner particles. If the rotation directions of the dispersion rotor and the classification rotor are reversed, the load on the classification rotor increases, and normal operation cannot be performed, which is not satisfactory from the viewpoint of toner productivity.

  The fine powder discharge pipe has a fine powder discharge port 45 for discharging fine powder and ultrafine powder removed by the classification rotor 35 to the outside of the apparatus.

  The surface modification apparatus further includes a cylindrical guide ring 36 as a guide means having an axis perpendicular to the top plate 43 in the main body casing 30 as shown in FIGS. 4 (A) and 4 (B). Have. The upper end of the guide ring 36 is provided at a predetermined distance from the top plate, and the guide ring is fixed to the main body casing 30 by a support so as to cover at least a part of the classification rotor 36. The lower end of the guide ring 36 is provided at a predetermined distance from the dispersion hammer 33 of the dispersion rotor 32. In the surface modification apparatus, a space between the classification rotor 35 and the dispersion rotor 32 is guided into a first space 47 outside the guide ring 36 and a second space 48 inside the guide ring 36. Divided by 36. The first space 47 is a space for guiding the finely pulverized product and the surface-modified particles to the classification rotor 35, and the second space guides the finely pulverized product and the surface-modified particles to the dispersion rotor. It is a space for. A gap between the dispersion hammer 33 and the liner 34 disposed on the dispersion rotor 32 is a surface modification zone 49, and the classification rotor 35 and a peripheral portion of the classification rotor 35 are a classification zone 50.

  Next, an outline of a surface modification method using a batch type surface modification apparatus used in the toner production method of the present invention will be described with reference to FIG.

  As shown in FIG. 7, the batch type surface reforming apparatus configured as described above introduces the finely pulverized material introduced into the raw material hopper 380 via the quantitative feeder 315, into the raw material input port of the input pipe. 37 through the raw material supply valve 38 and supplied from the raw material supply port 39 into the apparatus. In the surface reforming apparatus, the cold air generated by the cold air generating means 319 is supplied into the main body casing from the cold air inlet 46, and further, the cold water from the cold water generating means 320 is supplied to the cold water jacket 31 to Adjust the temperature to a predetermined temperature. The supplied finely pulverized product swirls in the first space 47 outside the cylindrical guide ring 36 by the swirl flow formed by the suction air volume by the blower 364, the rotation of the dispersion rotor 32 and the rotation of the classification rotor 35. However, the classification process is performed by reaching the classification zone 50 in the vicinity of the classification rotor 35. The direction of the swirl flow formed in the main body casing 30 is the same as the rotation direction of the dispersion rotor 32 and the classification rotor 35.

  The fine powder and super fine powder to be removed by the classification rotor 35 are sucked from the slit of the classification rotor 35 (see FIG. 2) by the suction force of the blower 364 and are passed through the fine powder discharge port 45 and the cyclone inlet 359 of the fine powder discharge pipe. 369 and bug 362. The finely pulverized product from which fine powder and ultrafine powder have been removed reaches the surface modification zone 49 in the vicinity of the dispersion rotor 32 via the second space 48 and is provided in the dispersion hammer 33 and the main body casing 30 provided in the dispersion rotor 32. The surface modification treatment of the particles is performed by the liner 34 thus formed. The particles subjected to the surface modification reach the classification rotor 35 again while turning along the guide ring 36, and fine particles and ultrafine particles are removed from the surface-modified particles by the classification rotor 35 classification. . After performing the treatment for a predetermined time, the discharge valve 41 is opened, and the surface-modified toner particles from which fine powder having a predetermined particle diameter or less and ultrafine powder are removed are taken out from the surface reforming apparatus.

  The toner particles adjusted to a predetermined weight average diameter, adjusted to a predetermined particle size distribution, and further surface-modified to a predetermined circularity are transferred to the external additive adding step by the toner particle transport means 321. .

  The surface reforming apparatus used in the present invention includes a dispersion rotor 32, a finely pulverized product (raw material) input unit 39, a classification rotor 35, and a fine powder discharge unit from the lower side in the vertical direction. Therefore, normally, the drive portion (motor or the like) of the classification rotor 35 is provided further above the classification rotor 35, and the drive portion of the dispersion rotor 32 is provided further below the dispersion rotor 32. The surface reforming apparatus used in the present invention is a finely pulverized product (raw material) classified into a classification rotor, such as a TSP classifier (manufactured by Hosokawa Micron Corporation) having only a classification rotor 35 described in JP-A-2001-259451. It is difficult to supply from the vertically upward direction of 35.

  It is preferable in terms of toner productivity that the fine powder generated by the batch-type surface reforming apparatus is collected by a collecting device such as a cyclone or a bag and returned to the toner raw material mixing step and reused.

The characteristics of the toner production method of the present invention are as follows:
(1) The surface modification portion of the dispersion hammer shown in FIG. 5 = a plurality of irregularities are provided on the surface facing the liner,
(2) Further, the plurality of irregularities provided in the surface modification portion of the dispersion hammer has a corrugated shape.
(3) Further, the plurality of irregularities provided in the surface modified portion of the dispersion hammer has a plurality of convex portions and concave portions formed between the convex portions and the convex portions, By surface-modifying the finely pulverized product (= surface-modified particles) with a batch-type surface reformer in which the repetition distance between the projections is 2.0 mm or more and less than 8.0 mm. ,
(4) To obtain surface-modified particles having a small particle size and high circularity with high yield.

  That is, as a result of examination by the present inventor, the surface modification portion of the dispersion hammer shown in FIG. 5 is provided with a plurality of irregularities on the surface facing the liner and provided on the surface modification portion of the dispersion hammer. The plurality of projections and depressions are configured so as to have a corrugated shape, and the plurality of projections and depressions provided on the surface modification portion of the dispersion hammer include a plurality of projections, the projections, and the projections. A batch-type surface reforming apparatus having a concave portion formed between the convex portion and the convex portion, the repetition distance between the convex portion and the convex portion being 2.0 mm or more and less than 8.0 mm, and incorporating the dispersion hammer Is operated in an appropriate state, surface-modified particles having a sharp particle size distribution and a high circularity can be obtained with high yield. Further, the surface state of the toner can be arbitrarily controlled, and a long-life toner having good developability, transferability, cleaning property, and stable chargeability can be obtained.

  For the above reason, it is considered that the surface shape state of the surface modified particles depends on the motion state of the surface modified particles in the surface modifying apparatus. In order to obtain a higher yield, it is considered important to control the motion state of the surface modified particles in the surface modifying apparatus. In the present invention, the surface modification device used in the surface modification step is a batch type surface modification device as shown in FIG. 1, whereby surface modified particles can be obtained efficiently. By making the shape of the dispersion hammer in the surface modification device of the type shown in FIG. 5 described above, the dispersion state of the surface modified particles in the surface modification zone in the batch surface modification device is further improved. I think it will be good. That is, by providing a plurality of irregularities in the surface modification portion of the dispersion hammer, an air flow is generated in the recess, and this air flow improves the dispersion state of the surface modified particles, and the surface modification It is thought that surface modification in the zone is performed smoothly. In addition, by setting and controlling the relationship between each device configuration of the batch type surface reforming apparatus and the operating conditions in the surface reforming zone to an appropriate state, a sharp particle size from which fine particles of a predetermined particle size or less have been removed is removed. Surface-modified particles having a distribution and high circularity can be obtained with higher yield.

  As a result of the study by the present inventors, when the minimum distance between the dispersion hammer and the liner is the same, the projections and the projections provided in the surface modification portion of the dispersion hammer When the repeating distance and the depth of the recess are less than 2.0 mm, surface-modified particles having a desired average circularity cannot be obtained, which is not satisfactory from the viewpoint of toner productivity. This is because the repetition distance between the convex portion and the convex portion of the surface modification portion of the dispersion hammer is narrow and the depth of the concave portion is shallow, so that the amount of air flow in the concave portion is reduced, and the surface modification It is considered that the momentum of the surface modified particles decreases due to the weak dispersion of the surface modified particles in the zone. In addition, the repetition distance between the convex portions and the convex portions and the depth of the concave portions are 8 If the thickness exceeds 0.0 mm, surface-modified particles having a desired average circularity cannot be obtained, which is also not satisfactory from the viewpoint of toner productivity. This is because the repetitive distance between the convex portion and the convex portion of the surface modified portion of the dispersion hammer is wide and the depth of the concave portion is deep, and as a result, there is a gap between the dispersion hammer and the liner. This is because the minimum distance becomes wide and the momentum of the surface modified particles in the surface modification zone decreases.

  Therefore, it is preferable that the repetition distance between the convex portion provided on the surface modified portion of the dispersing hammer and the convex portion is 2.0 mm or more and 8.0 mm or less, and the depth h of the concave portion is 2. It is preferable that the particle size is 0 mm or more and 8.0 mm or less in order to obtain surface-modified particles having a sharp particle size distribution from which fine powder having a predetermined particle size or less is removed and having a high degree of circularity with higher yield.

  Furthermore, in the toner production method of the present invention, it is preferable that the surface of the dispersing hammer and / or liner is coated with a chromium alloy plating containing at least chromium carbide.

As the base material of the dispersing hammer and / or liner, carbon steel such as S45C or chromium molybdenum steel such as SCM material is often used. By coating the surface of these base materials with a chromium alloy, the surface hardness is increased, the wear resistance is increased, and a long-life dispersion hammer or liner is obtained. Here, chromium carbide (Cr ₂₃ C ₆ ) present in the chromium alloy having a strong intermolecular bonding force exists from the surface layer to a certain depth or more, specifically, to a depth of 5 μm or more. It is possible to improve the adhesion of the film and to reduce the frequency of occurrence of phenomena such as peeling and cracking as much as possible.

  In the present invention, the coating of the chromium alloy containing chromium carbide on the base material surface is processed by “plating”, and the surface can be finished uniformly and smoothly, and the friction coefficient can be reduced to improve the wear resistance. Become. An example of such a plating process is a dicron process (Chiyoda Daiichi Kogyo Co., Ltd.).

  Furthermore, in the toner production method of the present invention, it is preferable that the finely pulverized product (raw material) supplied to the raw material inlet 37 of the surface reforming device has a specific particle size distribution. Furthermore, it is preferable that the amount of ultra fine powder of toner particles (surface modified particles) after being processed by the surface modifying device is controlled to a predetermined amount.

  In the present invention, the weight average particle diameter of the finely pulverized product is 3.5 to 9.0 μm, and the ratio of particles having a particle diameter of 4.00 μm or less is 50 to 80% by number. The ratio of particles (fine powder) having an average particle diameter of 4.5 to 9.0 μm and a particle diameter of 4.00 μm or less is 5 to 40% by number, and further measured with a flow particle image measuring device for toner particles. In the particle diameter distribution based on the number of particles having an equivalent circle diameter of 0.6 μm or more and 400 μm or less, the ratio of toner particles having an equivalent circle diameter of 0.6 μm or more and less than 2 μm (ultra fine powder) is 0 to 10% by number. Is preferred.

  The particle size distribution of the finely pulverized product affects the classification efficiency. When there are many fine particles in the finely pulverized product, the classification time becomes long, and even particles that do not need to be classified and removed are removed by classification, which may cause a reduction in classification yield. Furthermore, the cohesiveness of the finely pulverized product becomes high when classification is performed, and it may be difficult to remove the ultrafine powder that should be removed from the toner particles, and the resulting toner is likely to be fogged.

  Therefore, when the weight average particle size of the finely pulverized product is smaller than 3.5 μm, the cohesiveness between the particles becomes high and efficient classification may be difficult. On the other hand, when the weight average particle size of the finely pulverized product is larger than 9.0 μm, it is not preferable for the obtained toner to form a clear image quality. On the other hand, when the ratio of particles having a particle diameter of 4.00 μm or less is less than 50% by number, it is difficult to form a clear image with the obtained toner. On the other hand, when the proportion of particles having a particle size of 4.00 μm or less is more than 80% by number, the cohesiveness of the finely pulverized product becomes high and it is difficult to obtain a good classification yield. Furthermore, when the ratio of particles having a particle size of 4.00 μm or less is more than 80% by number, the ultra fine powder in the finely pulverized product tends to increase, which is not preferable. The proportion of particles having a particle size of 4.00 μm or less in the finely pulverized product is preferably 55 to 75% by number.

  The particle size distribution can be measured by various methods, but in the present invention, a Coulter counter multisizer was used.

  As a measuring device, a multisizer type II or type IIe (manufactured by Coulter Co.) of a Coulter counter is used, and an interface (manufactured by Nikkiki) that outputs number distribution and volume distribution is connected to a general personal computer. A 1% NaCl aqueous solution is prepared using special grade or first grade sodium chloride. As a measuring method, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and measured using a Coulter counter Multisizer II type with a 100 μm aperture. The volume and number of toners are measured to calculate a volume distribution and a number distribution, and a weight-based weight average diameter obtained from the volume distribution is obtained.

  Further, in the particle size distribution based on the number of particles having an equivalent circle diameter of 0.6 μm or more and 400 μm or less, which is measured by a flow type particle image measuring apparatus for toner particles processed by the surface modification device of the present invention, It is preferable to control the ratio of toner particles (ultrafine powder) having an equivalent diameter of 0.6 μm or more and less than 2 μm to a range of 0 to 10% by number. When the proportion of toner particles having an equivalent circle diameter of 0.6 μm or more and less than 2 μm is more than 10% by number, the obtained toner is not preferable because fog phenomenon easily occurs. The ratio of toner particles having an equivalent circle diameter of 0.6 μm or more and less than 2 μm is more preferably 8% by number or less.

  Further, the average circularity a measured by the flow type particle image measuring apparatus for the toner particles processed by the surface modifying apparatus of the present invention is preferably 0.935 to 0.980.

  As a result of studies by the present inventors, the average circularity a is 0.935 or more, preferably 0.940 or more, more preferably 0.945 or more, thereby improving transfer efficiency without impairing developability. It was found that the dot reproducibility was improved. Moreover, it turned out that the effect of the fluidity | liquidity provision by an external additive becomes large.

  When the average circularity is less than 0.935, the fluidity imparting effect by the external additive is reduced, so that the toner fluidity is lowered, the toner charge amount varies, the transfer efficiency is lowered, and the dot A decrease in reproducibility tends to occur.

  “Surface modification” in the present invention means smoothing the unevenness of the particle surface, and means that the appearance shape of the particle is close to a sphere. As an indicator of the degree of surface modification of the surface modified particles of the present invention, the average circularity is used as an index in the present invention.

  The average circularity in the present invention is measured using a flow type particle image measuring device “FPIA-2100 type” (manufactured by Sysmex Corporation), and is calculated using the following equation.

  Here, “particle projection area” is the area of the binarized particle image, and “perimeter of the particle projection image” is defined as the length of the contour line obtained by connecting the edge points of the particle image. . The measurement uses the perimeter of the particle image when image processing is performed at an image processing resolution of 512 × 512 (pixels of 0.3 μm × 0.3 μm).

  In the present invention, the circularity is an index indicating the degree of unevenness of the particles, and is 1.000 when the particles are perfectly spherical. The more complicated the surface shape, the smaller the circularity.

  The average circularity C, which means the average value of the circularity frequency distribution, is calculated from the following equation, where ci is the circularity (center value) at the dividing point i of the particle size distribution and m is the number of measured particles.

  The circularity standard deviation SD is calculated from the following equation where the average circularity C, the circularity ci of each particle, and the number of measured particles are m.

  “FPIA-2100”, which is a measuring device used in the present invention, calculates the circularity of each particle, and then calculates the average circularity and the circularity standard deviation. .4 to 1.0 are divided into classes equally divided every 0.01, and the average circularity and the circularity standard deviation are calculated using the center value of the division points and the number of measured particles.

  As a specific measuring method, 10 ml of ion-exchanged water from which impure solids have been removed in advance is prepared in a container, and after adding a surfactant (preferably alkylbenzene sulfonate) as a dispersant, Add 0.02 g of the measurement sample and disperse it uniformly. As a means for dispersion, an ultrasonic disperser “Tetora 150 type” (manufactured by Nikka Ki Bios Co., Ltd.) is used, and dispersion treatment is performed for 2 minutes to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of this dispersion may not be 40 degreeC or more. In order to suppress variation in circularity, the installation environment of the apparatus is controlled at 23 ° C. ± 0.5 ° C. so that the temperature inside the flow type particle image analyzer FPIA-2100 is 26 to 27 ° C. Preferably, autofocus is performed using 2 μm latex particles every 2 hours.

Dispersion condition device by ultrasonic oscillator : UH-150 (manufactured by SMT Co., Ltd.)
OUTPUT level: 5
Constant mode

  For the measurement of the circularity of the particles, the flow type particle image measuring device is used, the concentration of the dispersion is readjusted so that the toner particle concentration at the time of measurement is 3000 to 10,000 / μl, and 1000 or more particles are obtained. measure. After the measurement, using this data, data having an equivalent circle diameter of less than 2 μm is cut to determine the average circularity of the particles.

  Furthermore, the measurement device “FPIA-2100” used in the present invention improves the magnification of the processed particle image as compared with “FPIA-1000” used to calculate the shape of the toner or toner particles. By improving the processing resolution of the captured image (256 × 256 → 512 × 512), the accuracy of particle shape measurement is improved, thereby achieving more reliable capture of fine particles. Therefore, the FPIA 2100 is more useful when the shape needs to be measured more accurately as in the present invention.

  The outline of the measurement in the present invention is as follows.

  The sample dispersion is passed through a flow path (expanded along the flow direction) of a flat and flat flow cell (thickness: about 200 μm). The strobe and the CCD camera are mounted on the flow cell so as to be opposite to each other so as to form an optical path that passes through the thickness of the flow cell. While the sample dispersion is flowing, strobe light is irradiated at 1/30 second intervals to obtain an image of the particles flowing through the flow cell, so that each particle has a certain range parallel to the flow cell. Photographed as a two-dimensional image. From the area of the two-dimensional image of each particle, the diameter of a circle having the same area is calculated as the equivalent circle diameter. The circularity of each particle is calculated from the projected area of the two-dimensional image of each particle and the perimeter of the projected image using the above circularity calculation formula.

  Further, in the present invention, in the particle size distribution based on the number of toner particles (after the surface modification treatment) having a circle equivalent diameter of 0.6 μm or more and 400 μm or less, which is measured by a flow type particle image measuring device, it is equivalent to a circle. The proportion of toner particles having a diameter of 0.6 μm or more and less than 2 μm is preferably 0 to 10% by number. The ratio of toner particles having such an equivalent circle diameter is preferably 0 to 10% by number, more preferably 0 to 8% by number, and further preferably 0 to less than 5% by number. Toner particles having an equivalent circle diameter of 0.6 μm or more and less than 2 μm have a great influence on the developability of the toner, in particular, the fog characteristics. Such a fine particle toner has an excessively high chargeability, is easily developed excessively at the time of developing the toner, and appears as fog on the image. However, in the present invention, the fog can be reduced by the small proportion of the fine particle toner.

  Further, the amount of ultrafine powder in the toner particles can be used as an evaluation standard that is preferably used in the present invention. This is because it is recognized that the amount of ultrafine powder has a correlation with the fog in the toner image. The amount of ultrafine powder is determined by the number% of particles having an equivalent circle diameter of 2.0 μm or less in the particle size distribution measured by FPIA-2100. The abundance of particles having an equivalent circle diameter of 2.0 μm or less is preferably 10% by number or less in order to maintain a good fog level in image evaluation.

  Further, in the present invention, the transmittance (%) of the toner particles, which are the surface modified particles obtained by the batch type surface modifying apparatus, in a 45 volume% methanol aqueous solution is in the range of 20% or more and less than 70%. It is preferable that it exists in.

  Since the toner of the present invention contains a wax in the toner, at least the wax is present on the surface of the toner particles. When the wax on the toner surface is small, the releasing effect at the time of fixing hardly appears, and the low temperature fixing effect desired from the viewpoint of energy saving decreases. In addition, when there is a lot of wax on the toner surface, the charge imparting member is contaminated with wax, and, for example, the resistance is increased by fusing on the developing sleeve, and the effectiveness of the actual development bias for development is reduced. In some cases, the image density decreases and the development durability deteriorates. As described above, when the wax is contained in the toner, it is important to control the amount of wax on the toner surface.

  As a result of the study by the present inventors, when the transmittance (%) of the toner particles as surface modified particles in a 45 volume% methanol aqueous solution is smaller than 20%, a binder resin and a hydrophilic colorant, for example, on the toner surface, for example, Dyes and C.I. Since B and the like are biased, it is considered that the difference in charging environment is large. This makes it impossible to obtain a sufficient contrast of the photosensitive drum, so that the image density fluctuation is likely to be large and the gradation is poor. Therefore, in a full-color image, color reproducibility is very poor. . Conversely, when the transmittance (%) in a 45% by volume methanol aqueous solution is greater than 70%, there are many release agents such as organic pigments and wax on the toner surface, so that insulating substances gather together. However, it is considered that the charging ability of the toner is broadened because the charging ability is quite different. This is because there is little transfer of charge between toners during continuous copying, so the difference in charge level opens, and eventually fogging and toner scattering occur.

  That is, by making the transmittance (%) of toner particles as surface modified particles in a 45 volume% methanol aqueous solution in a range of 20% or more and less than 70%, various materials can be present on the toner surface in a balanced manner. Thus, a long-life toner having good developability, transferability, cleaning property, and stable chargeability can be obtained.

  The amount of wax on the toner surface can be measured easily and with high accuracy by measuring the transmittance (%) in a 45% by volume aqueous solution of methanol.

  In this measurement method, toner particles are forcibly dispersed once in a methanol / water mixture solvent to easily reveal the characteristics of the surface wax amount of each toner particle, and then the transmittance after a certain time is measured. The amount of wax on the toner surface can be accurately grasped.

  In this invention, the transmittance | permeability in 45 volume% methanol aqueous solution was measured in the following procedures.

(1) Preparation of toner dispersion An aqueous solution having a volume mixing ratio of methanol: water of 45:55 is prepared. 10 ml of this aqueous solution is placed in a 30 ml sample bottle (Nippon Denka Glass: SV-30), and 20 mg of toner is impregnated on the liquid surface to cover the bottle. Then, it is made to shake at 2.5S-1 for 5 seconds with a Yayoi type shaker (model: YS-LD). At this time, the angle of shaking is such that the shaking column moves 15 degrees forward and 20 degrees backward, assuming that the vertical (vertical) of the shaker is 0 degree. The sample bottle is fixed to a fixing holder (with the sample bottle lid fixed on the extension at the center of the column) attached to the tip of the column. After removing the sample bottle, the dispersion after 30 seconds is used as a dispersion for measurement.

(2) Transmittance measurement The dispersion obtained in (1) was placed in a 1 cm square quartz cell, and the transmittance at a wavelength of 600 nm of the dispersion after 10 minutes using a spectrophotometer MPS2000 (manufactured by Shimadzu Corporation) ( %).
Transmittance (%) = I / I0 × 100 I: incident light flux, I0: transmitted light flux

  In the toner production method of the present invention, the surface modification time in the batch type surface modification apparatus is 5 seconds or more and 180 seconds or less, more preferably 15 seconds or more and 150 seconds or less, and further preferably 15 seconds or more and 120 seconds. It is preferable that it is below second. When the surface modification time is less than 5 seconds, since the surface modification time is too short, surface modified particles having a desired circularity and average surface roughness cannot be obtained, which is not preferable in terms of toner quality. In addition, when the surface modification time exceeds 180 seconds, the surface modification time is too long, so it causes surface deterioration due to heat generated during surface modification, occurrence of in-machine fusion, and reduction in processing capacity. This is not satisfactory from the viewpoint of toner productivity.

  Further, in the toner production method of the present invention, the cold air temperature T1 introduced into the batch type surface reforming apparatus is preferably 5 ° C. or less, more preferably 0 ° C. or less, and further preferably −5 ° C. or less. . By setting the cold air temperature T1 introduced into the batch type surface reforming apparatus to 5 ° C. or less, preferably 0 ° C. or less, more preferably −5 ° C. or less, surface alteration due to heat generated during surface modification, Fusion can be prevented. If the cold air temperature T1 introduced into the batch-type surface reforming apparatus exceeds 5 ° C. or more, surface modification due to heat generated during the surface modification or in-machine fusion is likely to occur. It is not satisfactory enough.

  In addition, as a refrigerant used in the cold air generator introduced into the batch type surface reforming apparatus, an alternative chlorofluorocarbon is preferable from the viewpoint of environmental problems of the entire earth.

  Alternative CFCs include R134A, R404A, R407C, R410A, R507A, R717, etc. Among them, R404A is particularly preferable from the viewpoint of energy saving and safety.

  The cold air introduced into the batch type surface reforming apparatus is preferably dehumidified from the viewpoint of preventing condensation in the apparatus from the viewpoint of toner productivity. A well-known thing can be used as a dehumidifier. The supply air dew point temperature is preferably −15 ° C. or lower, and more preferably −20 ° C. or lower.

  Further, in the toner production method of the present invention, the batch type surface reforming apparatus is provided with a jacket for cooling inside the apparatus, and a refrigerant (preferably cooling water, more preferably ethylene glycol or the like) is provided in the jacket. The surface-modified particles are preferably subjected to a surface modification treatment while passing through an antifreeze solution. In-machine cooling by the jacket can prevent surface alteration and in-machine fusion due to heat during surface modification.

  The temperature of the refrigerant passed through the jacket of the batch type surface reformer is preferably 5 ° C. or less, more preferably 0 ° C. or less, and further preferably −5 ° C. or less. By changing the temperature of the refrigerant passed through the jacket in the batch type surface reforming apparatus to 5 ° C. or less, more preferably 0 ° C. or less, and further preferably −5 ° C. or less, surface alteration due to heat generated during the surface modification In addition, in-machine fusion can be prevented. If the temperature of the refrigerant introduced into the cooling jacket exceeds 5 ° C., surface deterioration due to heat generated during surface modification and in-machine fusion are likely to occur. Absent.

  Furthermore, in the method for producing the toner of the present invention, the temperature T2 in the fine powder outlet located behind the classification rotor in the batch type surface reforming apparatus is 60 ° C. or less, more preferably 55 ° C. or less, and further preferably 50 ° C. The following is preferable. The temperature T2 in the fine powder outlet located behind the classification rotor in the batch type surface reforming apparatus is 60 ° C. or less, more preferably 55 ° C. or less, and even more preferably 50 ° C. or less. It can prevent surface deterioration due to heat and in-machine fusion. If the temperature T2 in the fine powder outlet located behind the classifying rotor in the batch type surface reforming apparatus exceeds 60 ° C, it is assumed that the temperature above the surface reforming zone has an effect. However, it is not satisfactory from the viewpoint of toner productivity because it easily causes surface deterioration due to heat generated during surface modification and in-machine fusion.

  Furthermore, in the method for producing the toner of the present invention, the temperature T2 in the fine powder outlet located behind the classification rotor in the batch type surface reformer and the cold air temperature T1 introduced into the batch type surface reformer. The temperature difference ΔT (T2−T1) is preferably 100 ° C. or less, more preferably 90 ° C. or less, and still more preferably 80 ° C. or less. The temperature difference ΔT (T2−T1) between the temperature T2 in the fine powder outlet located behind the classification rotor in the batch type surface reformer and the cold air temperature T1 introduced into the batch type surface reformer is 100 ° C. or less. More preferably, the temperature is set to 90 ° C. or less, and more preferably 80 ° C. or less, so that surface deterioration due to heat generated during surface modification and in-machine fusion can be prevented. A temperature difference ΔT (T2−T1) between the temperature T2 in the fine powder outlet located behind the classification rotor in the batch type surface reformer and the cold air temperature T1 introduced into the batch type surface reformer is 100 ° C. In the surface modification zone, it is presumed that a higher temperature has an effect on the surface modification zone, and it is easy to cause surface deterioration due to heat generated during surface modification and in-machine fusion. It is not satisfactory from the point of view.

  Furthermore, in the toner production method of the present invention, it is preferable that the minimum distance between the dispersion hammer on the dispersion rotor and the liner in the batch type surface modification device is 0.5 mm to 15.0 mm. Furthermore, it is preferable to set it as 1.5 mm thru | or 10.0 mm.

  In the present invention, it is preferable that the tip peripheral speed of the classification rotor 35 having the largest diameter is 30 to 120 m / sec. The tip circumferential speed of the classification rotor is more preferably 50 to 115 m / sec, and further preferably 70 to 110 m / sec. If it is slower than 30 m / sec, the classification yield tends to decrease, and the amount of ultrafine powder tends to increase in the toner particles. If it is faster than 120 m / sec, the problem of increased vibration of the device is likely to occur.

  Furthermore, it is preferable that the tip peripheral speed of the portion with the largest diameter of the dispersion rotor 32 is 20 to 150 m / sec. The tip peripheral speed of the dispersion rotor 32 is more preferably 40 to 140 m / sec, and further preferably 50 to 130 m / sec. When it is slower than 20 m / sec, it is difficult to obtain surface-modified particles having sufficient circularity, which is not preferable. When the speed is higher than 150 m / sec, particles are likely to be fixed inside the apparatus due to the temperature rise inside the apparatus, and the classification yield of the toner particles is likely to be lowered. By setting the tip peripheral speeds of the classification rotor 35 and the dispersion rotor 32 in the above range, the classification yield of the toner particles can be improved and the surface modification of the particles can be performed efficiently.

  Furthermore, it is preferable that the minimum distance between the guide ring in the batch type surface reforming apparatus and the inner wall of the apparatus is 20.0 mm to 60.0 mm, and more preferably 25.0 mm to 55.0 mm. It is preferable.

  Furthermore, the minimum distance between the upper part of the dispersing hammer installed on the upper surface of the dispersing rotor in the batch type surface reforming apparatus and the lower part of the cylindrical guide ring may be 2.0 mm to 50.0 mm. More preferably, it is preferably 5.0 mm to 45.0 mm.

  As a result of the study by the present inventors, when the minimum distance between the dispersion rotor and the liner in the batch type surface reforming apparatus is less than 0.5 mm, the load on the apparatus itself is increased, and at the same time during the surface modification. Since it is excessively pulverized and easily undergoes surface alteration and in-machine fusion due to heat, it is not satisfactory from the viewpoint of toner productivity. If the minimum distance between the dispersion rotor and the liner exceeds 15.0 mm, the processing capacity must be reduced to obtain surface-modified particles having a desired average circularity. This is not satisfactory in terms of toner productivity.

  Further, if the rotational peripheral speed of the dispersion rotor in the batch type surface reforming apparatus is less than 30 m / sec, the processing capacity must be lowered to obtain a predetermined circularity, which is sufficiently satisfactory in terms of toner productivity. It is not a thing. Further, if the rotational speed of the dispersion rotor exceeds 175 m / sec, the load on the apparatus itself increases, and at the same time, the surface-modified particles are excessively pulverized during the surface modification, and at the same time, the surface is altered by heat. This is also not satisfactory from the standpoint of toner productivity.

  Further, if the minimum distance between the guide ring in the batch type surface reforming apparatus and the inner wall of the apparatus is less than 20.0 mm, the residence time in the second space outside the guide ring is shortened, and the surface modification is performed. There is a possibility that the fine particles may flow out to the first space inside the guide ring in a state where the surface is not sufficiently modified, which is not satisfactory in terms of toner productivity. Further, if the minimum distance between the guide ring in the batch type surface modification apparatus and the inner wall of the apparatus exceeds 60.0 mm, the residence time of the surface modification particles in the vicinity of the dispersion rotor becomes long, It may be excessively pulverized during surface modification and may cause surface deterioration due to heat or in-machine fusion, which is not satisfactory from the viewpoint of toner productivity.

  Further, when the minimum distance between the upper part of the dispersing hammer installed on the upper surface of the dispersing rotor in the batch type surface reforming apparatus and the lower part of the cylindrical guide ring is less than 2.0 mm, the load on the apparatus itself is reduced. At the same time, the residence time in the first space inside the guide ring becomes longer, and it is sufficiently satisfied from the viewpoint of toner productivity because it is over-pulverized during surface modification and is likely to cause surface alteration and in-machine fusion due to heat. It is not possible. Further, if the minimum distance between the upper part of the dispersing hammer installed on the upper surface of the dispersing rotor and the lower part of the cylindrical guide ring exceeds 50.0 mm, the surface modified particles are sufficiently surface-modified. There is a possibility of causing a short path of flowing out into the second space outside the guide ring in an unfinished state, which is also not satisfactory in terms of toner productivity.

  As a result of the study by the present inventors, by controlling the surface modification conditions of the batch surface modification device within the above range, an increase in fine powder during the surface modification is prevented, and the influence of heat during the surface modification. Thus, the surface state of the surface-modified particles can be controlled to a desired level, and a long-life toner having good developability, transferability, cleaning property, and stable chargeability can be obtained.

  That is, according to the toner manufacturing method of the present invention, the surface state of the surface modified particles can be controlled to a desired one. As described above, this is because the surface reforming time from the closing of the raw material supply valve to the opening of the product discharge valve, the cold air temperature T1, the cooling water temperature, the fine powder outlet temperature T2, the fine powder outlet temperature T2 ΔT with cold air temperature T1, shape of dispersion hammer on dispersion rotor, minimum distance between dispersion hammer and liner, rotational peripheral speed of dispersion rotor, minimum distance between guide ring and device inner wall, installed on top of dispersion rotor This is because the surface state of the toner can be arbitrarily controlled by controlling the minimum distance between the upper portion of the dispersing hammer and the lower portion of the cylindrical guide ring to an appropriate state.

  Next, the method for producing the toner of the present invention will be outlined. In order to produce the toner in the present invention, for example, a binder resin, a colorant and a wax, and further, if necessary, a charge control agent and other additives are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill and then heated. A kneaded product is obtained by melting or kneading using a heat kneader such as a roll, kneader or extruder to disperse or dissolve the colorant and wax in the binder resin. The obtained kneaded product is cooled and solidified, and the solidified product is roughly pulverized, and then finely pulverized by an air impact pulverizer such as a jet mill or a mechanical impact pulverizer to obtain a finely pulverized product. As an air-type impact pulverizer, an I-DS type pulverizer (manufactured by Nippon Pneumatic Co., Ltd.), a collision-type airflow pulverizer using jet air described in FIG. 1 of JP-A No. 2003-262981, A method of obtaining a finely pulverized product using a classifier described in FIG. 7 of Kaihei 2003-262981 is mentioned. Examples of the mechanical pulverizer include a turbo mill manufactured by Turbo Industry Co., Ltd., a kryptron manufactured by Kawasaki Heavy Industries, Ltd., an inomizer manufactured by Hosokawa Micron Co., Ltd., and a super rotor manufactured by Nisshin Engineering Co., Ltd. Thereafter, by performing the classification of finely pulverized product and the surface treatment of the particles simultaneously using the batch type surface treatment apparatus described above, toner particles having a desired shape and a desired particle size distribution are obtained as surface modified particles. Can do. The toner in the present invention is preferably toner particles obtained by externally adding an external additive to toner particles and having an external additive.

  Next, the constituent material of the toner particles containing the binder resin, wax and colorant according to the present invention will be described. In the present invention, various known toner particle materials can be used.

  As the binder resin constituting the toner particles, a resin usually used for toner can be used. The following are listed.

  Examples of the binder resin used in the present invention include polystyrene; a styrene-substituted homopolymer such as poly-p-chlorostyrene and polyvinyltoluene; a styrene-p-chlorostyrene copolymer and a styrene-vinyltoluene copolymer. Styrene-vinyl naphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinylmethyl Styrene copolymers such as ether copolymers, styrene-vinyl ethyl ether copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers. Polymer; polyvinyl chloride, pheno Resin, natural modified phenolic resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin , Coumarone indene resin and petroleum resin. In the present invention, a crosslinked styrene resin and a crosslinked polyester resin are preferred binder resins for surface modification of the particles.

  As a comonomer for the styrene monomer of the styrenic copolymer, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, Monocarboxylic acid having a double bond such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide or a derivative thereof; maleic acid, butyl maleate, methyl maleate, malee Dicarboxylic acids having a double bond such as dimethyl acid or derivatives thereof; vinyl esters such as vinyl chloride, vinyl acetate and vinyl benzoate; ethylene-based olefins such as ethylene, propylene and butylene; Rumechiruketon, vinyl ketones such as vinyl hexyl ketone; and the like; vinyl methyl ether, vinyl ethyl ether, vinyl ether such as vinyl isobutyl ether. These vinyl monomers are used alone or in combination of two or more.

  Examples of the crosslinking agent mainly include compounds having two or more polymerizable double bonds. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate and 1,3-butanediol dimethacrylate; divinylaniline; And divinyl ether, divinyl sulfide and divinyl sulfone divinyl compounds; and compounds having three or more vinyl groups. These can be used alone or in admixture of two or more.

  Among the physical properties of the toner, those resulting from the binder resin include a molecular weight distribution measured by gel permeation chromatography (GPC) soluble in tetrahydrofuran (THF) in a molecular weight range of 2,000 to 50,000. More preferably, 50 to 90% of the component having at least one peak and having a molecular weight of 1000 to 30000 is present.

  In the present invention, the following wax is used as the material for the toner particles from the viewpoint of improving the releasability from the fixing member during fixing and improving the fixing property. Examples of the wax include paraffin wax and derivatives thereof, microcrystalline wax and derivatives thereof, Fischer-Tropsch wax and derivatives thereof, polyolefin wax and derivatives thereof, and carnauba wax and derivatives thereof. Derivatives of these waxes include oxides, block copolymers with vinyl monomers, and graft modified products. Examples of the wax include alcohol, fatty acid, acid amide, ester, ketone, hydrogenated castor oil and derivatives thereof, plant wax, animal wax, mineral wax, and petrolactam.

  In the present invention, a charge control agent is preferably blended (internally added) into toner particles or mixed (externally added) with toner particles as a material for toner particles. The charge control agent makes it possible to control the optimum charge amount according to the development system, and in particular, it is possible to produce a toner with a more stable balance between the particle size distribution and the charge amount.

  As the negative charge control agent for controlling the toner to be negatively charged, organometallic complexes and chelate compounds are effective. Examples of the organometallic complex include a monoazo metal complex, an acetylacetone metal complex, an aromatic hydroxycarboxylic acid metal complex, and an aromatic dicarboxylic acid metal complex. Further, the negative charge control agent includes aromatic hydroxycarboxylic acid, aromatic monocarboxylic acid and aromatic polycarboxylic acid and metal salts thereof; anhydrous hydroxycarboxylic acid, aromatic monocarboxylic acid and aromatic polycarboxylic acid anhydride. Products; ester compounds of aromatic hydroxycarboxylic acids, aromatic monocarboxylic acids and aromatic polycarboxylic acids, and phenol derivatives such as bisphenol.

  Examples of positive charge control agents for controlling the toner to be positively charged include nigrosine and fatty acid metal salts modified from nigrosine; tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate Quaternary ammonium salts and their lake pigments; phosphonium salts such as tributylbenzylphosphonium-1-hydroxy-4-naphthosulfonate and tetrabutylphosphonium tetrafluoroborate and lake pigments thereof; triphenylmethane dyes and lakes thereof Pigment (Phosphotungstic acid, phosphomolybdic acid, phosphotungstic molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.); metal salt of higher fatty acid; dibutyls Oxide, dioctyltin oxide, such as diorganotin oxide dicyclohexyl tin oxide; dibutyl tin borate, dioctyl tin borate, include such diorgano tin borate dicyclohexyl tin borate. These charge control agents can be used alone or in combination of two or more.

  The charge control agent described above is preferably used in the form of fine particles. In this case, the number average particle diameter of these charge control agents is more preferably 4 μm or less, and particularly preferably 3 μm or less. When these charge control agents are internally added to the toner particles, it is preferable to add 0.1 to 20 parts by weight, particularly 0.2 to 10 parts by weight, to 100 parts by weight of the binder resin.

  In the present invention, various conventionally known colorants can be used as the toner particle material. The colorant used in the present invention is adjusted to black by a chromatic colorant such as carbon black or a magnetic material, a yellow colorant, a magenta colorant, and a cyan colorant shown below as a black colorant. A combination is used.

  As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 168, 174, 176, 180, 181 and 191.

  As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48; 2, 48; 3, 48; 4, 57; 1, 81; 1, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254.

  As the cyan colorant, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds are used. Specifically, C.I. I. Pigment blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66.

  These colorants can be used alone or in combination and further in the form of a solid solution. In the present invention, the colorant is selected in consideration of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. These chromatic non-magnetic colorants are contained in the toner particles in a total amount of 1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

  Furthermore, in order to improve fluidity, transferability and the like, a toner can be obtained by externally adding an external additive such as a known inorganic fine powder to the toner particles and passing through a known sieving step.

  Hereinafter, the present invention will be described more specifically with specific toner production methods, examples, and comparative examples, but the present invention is not limited to these examples.

<Example 1>
Unsaturated polyester resin [polyoxypropylene (2,2) -2,2 bis (4-hydroxyphenyl) propane / polyoxyethylene (2,2) -2,2 bis (4-hydroxyphenyl) propane / terephthalic acid / Unsaturated polyester resin consisting of trimellitic anhydride / fumaric acid, Mw: 17000, Mw / Mn: 4.5, Tg: 60 ° C.]: 100 parts by mass Copper phthalocyanine pigment (CI Pigment Blue 15: 3): 4 Part by mass Paraffin wax (maximum endothermic peak 73 ° C.): 5 parts by mass Charge control agent (salicylic acid metal complex E-88 (manufactured by Orient)): 4 parts by mass Henschel mixer (FM-75 type, Mitsui Miike Chemical) Machine), and then mixed at a temperature of 110 ° C. (PCM-30 type, Ikekai Tekko Co., Ltd.) ) Was kneaded in. The obtained kneaded material was cooled and coarsely pulverized to 1 mm or less with a hammer mill to obtain a coarsely pulverized material.

  Using the jet mill (IDS-5 type pulverizer, manufactured by Nippon Pneumatic Co., Ltd.) using jet air, the obtained coarsely crushed product is fed at a feed rate of 3 kg / hr and an air pressure of 0.6 MPa. By finely pulverizing under conditions, a finely pulverized product was obtained. The finely pulverized product had a weight average diameter D4 of 5.0 μm, a ratio of particles having a particle diameter of 4.00 μm or less was 75% by number, and an average circularity of 0.925.

The obtained finely pulverized product was put into a batch type surface modification treatment apparatus shown in FIGS. 1 and 7, and the finely pulverized product was classified and surface-modified at the same time. At this time, in this embodiment, the outer diameter D of the dispersion rotor 32 shown in FIG. 3A is 400 mm, and twelve dispersion hammers 33 shown in FIGS. installed. 8B, the repetition distance C between the protrusions of the surface modification portion of the dispersion hammer 33 is 3.0 mm, and the depth h of the recess of the surface modification portion of the dispersion hammer 33 is 3. The L / W / H of the dispersion hammer 33 was 40 mm / 20 mm / 30 mm, respectively. The rotational peripheral speed of the dispersion rotor 32 that rotates counterclockwise when viewed from above is 121 m / sec. The inner diameter d of the cylindrical guide ring 36 shown in FIGS. 4A and 4B is set to 350 mm, and the dispersion hammer 33 at the lower part of the guide ring 36 and the upper end of the dispersion rotor 32 shown in FIG. The distance A from the upper part was 5 mm, and the distance B between the apex of the triangular tooth of the dispersing hammer 33 and the apex of the triangular tooth of the liner 34 shown in FIG. 8B was 2 mm. Further, the inner diameter D of the liner 34 was set to 406 mm. 2A and 2B, the blade diameter D of the classification rotor 35 is 240 mm, the blade length L of the classification rotor 35 is 130 mm, and the rotation speed of the classification rotor 35 rotating counterclockwise as viewed from above Was 81 m / sec. The height H of the liner 34 shown in FIGS. 8A and 8B was 80 mm. The time for one cycle of classification and surface treatment of finely pulverized product is 60 sec (input time: 10 sec, treatment time: 30 sec, discharge time 20 sec), and the feed amount of the finely pulverized product is 65 / hr (accordingly, charging per cycle) The amount was about 1.08). The suction air volume of the blower 364 was 22 m ³ / min, the cold air temperature T1 was −20 ° C., and the temperature of the cold water passed through the cooling jacket was −10 ° C.

  As a result of operating for 12 minutes in this state, the temperature T2 in the fine powder discharge pipe behind the classification rotor 35 was stable at 35 ° C. ΔT (T2−T1) was 55 ° C. The classification yield was 72%.

As a result of measuring the particle size distribution and the circularity of the obtained surface-modified toner particles, the toner particles have a weight average diameter D ₄ of 5.8 μm and a ratio of 26 particles having a particle diameter of 4.00 μm or less. The ratio of particles having an equivalent circle diameter of 0.6 μm or more and less than 2 μm was 1.5% by number. The average circularity of the surface-modified toner particles was 0.954.

  To 100 parts by mass of the obtained surface-modified toner particles, 1.2 parts by mass of hydrophobic silica fine powder was externally added and mixed to obtain a toner. 5 parts by mass of the obtained toner and 95 parts by mass of an acrylic resin-coated magnetic ferrite carrier were mixed to prepare a two-component developer. Using this two-component developer, 10,000 sheets of durable images were printed using a modified machine of Canon full color copier CLC1000 (with the oil application mechanism of the fixing unit removed). The fog level after 10,000 durable images were printed was evaluated according to the following evaluation criteria. The evaluation results are shown in Table 2.

  The fog evaluation was performed according to the following procedure. The average reflectance Dr (%) of plain paper before image printing was measured with a reflectometer (TC-6DS manufactured by Tokyo Denshoku Co., Ltd.). On the other hand, a solid white image (Vback: 150 V) was drawn on plain paper, and then the reflectance Ds (%) of the solid white image was measured to calculate Dr-Ds. The obtained Dr-Ds value was taken as the fog value and evaluated according to the following evaluation criteria.

Evaluation criteria A: very good level (less than 0.3%)
B: Good level (0.3% or more and less than 1.0%)
C: No problem level (1.0% or more and less than 2.0%)
D: Acceptable level (2.0% or more and less than 3.0%)
E: Bad level (3.5% or more)

<Reference example>
Toner particles were produced in the same manner as in Example 1 except that the surface modification portion of the dispersion hammer 33 = a flat surface without providing a plurality of irregularities on the surface facing the liner. Using the obtained toner particles, a two-component developer was prepared in the same manner as in Example 1, and image output was evaluated. The results are shown in Table 2.

<Example 2>
Toner particles were prepared in the same manner as in Example 1 except that the distance between the convex portions of the dispersing hammer 33 was 5.0 mm and the depth h of the concave portions was 5.0 mm. Using the obtained toner particles, a two-component developer was prepared in the same manner as in Example 1, and image output was evaluated. The results are shown in Table 4.

<Example 3>
Toner particles were prepared in the same manner as in Example 1 except that the repetition distance between the convex portions of the dispersing hammer 33 was 7.0 mm and the concave depth h was 7.0 mm. Using the obtained toner particles, a two-component developer was prepared in the same manner as in Example 1, and image output was evaluated. The results are shown in Table 4.

<Example 4>
Toner particles were prepared in the same manner as in Example 1 except that the repetition distance between the convex portions of the dispersing hammer 33 was 9.0 mm and the concave depth h was 9.0 mm. Using the obtained toner particles, a two-component developer was prepared in the same manner as in Example 1, and image output was evaluated. The results are shown in Table 4.

<Comparative example>
The finely pulverized product used in Example 1 was classified by a multi-division airflow classifier and introduced into the surface modification apparatus shown in FIG. 10 to perform surface modification.

  In FIG. 10, 151 is a main body casing, 158 is a stator, 177 is a stator jacket, 163 is a recycling pipe, 159 is a discharge valve, 219 is a discharge chute, and 164 is a raw material charging chute.

  In the apparatus, the powder particles and other fine solid particles supplied from the raw material charging chute 164 are instantaneously generated by a plurality of rotor blades 155 disposed in a rotating rotor 162 that rotates mainly at high speed in the impact chamber 168. In addition, the fine particles collide with the surrounding stator 158 and are dispersed in the system while loosening the agglomeration of the powder particles or other fine solid particles, and at the same time, other fine solid particles on the powder particle surface. Is attached by electrostatic force, van der Waals force or the like, or in the case of powder particles only, the particles are rounded or spheroidized. This state advances as the particles fly and collide. That is, the particles are processed by passing through a recycle pipe 163 a plurality of times along with the flow of the air flow generated by the rotation of the rotor blade 155. Further, when the particles are repeatedly hit from the rotor blade 155 and the stator 158, other fine solid particles are uniformly dispersed and fixed on the surface of the powder particles or in the vicinity thereof, or the powder particles only The shape of the particles becomes spherical.

  The particles that have been fixed are collected by the bag filter 362 that passes through the discharge chute 219 and communicates with the suction blower 364 by opening the discharge valve 159 by the discharge valve control device 128.

  In this comparative example, a rotating rotor 162 having a rotor blade 155 having a longest diameter of 242 mm was used, and the rotating peripheral speed of the rotating rotor 162 was set to 100 m / sec. The amount of finely pulverized product was 150 g and the processing time was 180 seconds. This was repeated about 10 times to obtain surface modified particles.

As a result of measuring the particle size distribution and the circularity of the resulting surface-modified toner particles, the toner particles have a weight average diameter D ₄ of 5.7 μm and a ratio of 32 particles having a particle diameter of 4.00 μm or less. The ratio of particles having an equivalent circle diameter of 0.6 μm or more and less than 2 μm was 6.2% by number. The average circularity of the surface-modified toner particles was 0.948.

  Next, using the obtained toner particles, a two-component developer was prepared in the same manner as in Example 1, and image output evaluation was performed. Although a result is shown in Table 6, it became a result inferior compared with an Example.

In the toner production method of the present invention, the finely pulverized product is classified and surface-modified, and the surface is preferably used in a process for obtaining surface-modified toner particles having a suitable particle size distribution. Schematic cross section of an example of reformer (A) Schematic horizontal projection of the classification rotor, and (B) Schematic sectional view of the classification rotor. (A) Horizontal projection view of distributed rotor and (B) Schematic vertical projection view of distributed rotor (A) The figure for demonstrating the diameter of a guide ring, (B) The perspective view of the support body of a guide ring and a guide ring (A) Schematic horizontal projection of the dispersion hammer, and (B) Schematic vertical projection of the dispersion hammer. (A) Schematic horizontal projection of liner, (B) Partial explanatory diagram of liner FIG. 7 is a partial flowchart for explaining the toner production method of the present invention. (A) The figure for demonstrating the clearance of a guide link and a dispersion | distribution hammer, (B) The clearance between a dispersion | distribution hammer and a liner, and the convex part provided in the surface modification part of a dispersion | distribution hammer, and a convex part Illustration for explaining the repeat distance Schematic sectional view of an example impinging airflow type pulverizer used in Reference Example of the present invention Schematic cross-sectional view of an example surface modification device used in the surface modification process of the comparative example

Explanation of symbols

30 Main body casing 31 Cooling jacket 32 Dispersion rotor 33 Dispersion hammer 34 Liner 35 Classification rotor 36 Guide ring 37 Material input port 38 Material supply valve 39 Material supply port 40 Product discharge port 41 Product discharge valve 42 Product extraction port 43 Top plate 44 Fine powder discharge Portion 45 Fine powder outlet 46 Cold air inlet 47 First space 48 Second space 49 Surface modification zone 50 Classification zone 151 Main body casing 155 Rotor blade 158 Stator 159 Discharge valve 163 Recycle pipe 164 Material input chute 168 Impact chamber 177 Stator Jacket 315 Constant supply unit 319 Cold air generation means 320 Cold water generation means 321 Toner particle transport means 359 Cyclone 362 Bug 364 Blower 369 Cyclone 380 Raw material hopper 431 Crusher 432 Classifier 4 33 Raw material supply machine 434 Transport pipe 435 Nozzle 436 Collision plate 437 Grinding chamber 438 Collector 439 Main body hopper 440 Center core 441 Separate core 442 Discharge pipe 443 Secondary air supply port

Claims (9)

A kneading step of melt-kneading a composition containing at least a binder resin and a colorant, a cooling step of cooling the obtained kneaded product, a step of pulverizing the cooled solidified product to obtain a finely pulverized product, and the obtained fine A step of performing a surface modification step for modifying the surface of the pulverized product to obtain toner particles,
The step of performing the surface modification step to obtain toner particles is performed using a batch type surface modification device,
The surface modification apparatus has at least a dispersion rotor for performing a surface modification treatment using a mechanical impact force, and a liner that is a fixed body arranged at a constant interval on the outer periphery of the dispersion rotor. And
The dispersion rotor has a dispersion hammer which is a surface-modified particle dispersion member on the upper surface portion thereof,
A plurality of the dispersion hammers are provided on the upper surface of the dispersion rotor, and the dispersion hammer is provided with a plurality of irregularities on the surface facing the liner. . The surface modification step includes a surface modification step for performing surface modification of particles contained in the obtained finely pulverized product, and a classification for removing fine powder and ultrafine powder contained in the obtained finely pulverized product. And a step of obtaining toner particles by simultaneously performing a classification step of performing
The step of simultaneously performing the surface modification step and the classification step to obtain toner particles is performed using a batch type surface modification device,
The surface reforming apparatus includes a cylindrical main body casing, a charging unit for charging the finely pulverized material into the main body casing, and fine powder and ultrafine powder having a predetermined particle size or less from the finely pulverized material charged into the main body casing. Classifying means having a classification rotor that rotates in a predetermined direction for continuous removal to the outside, a fine powder discharger for discharging the fine powder and super fine powder removed by the classification means to the outside of the main body casing, the fine powder, and the super A dispersion rotor that rotates in the same direction as the rotation direction of the classification rotor for surface modification treatment using mechanical impact force on particles contained in the finely pulverized product from which fine powder has been removed, and an outer periphery of the dispersion rotor A surface modifying means having a liner which is a fixed body which is arranged at a constant interval and has a large number of grooves on the surface, and forms a first space and a second space in the main body casing To do Guiding means having a cylindrical shape, and the toner particles surface modification treatment is performed by the dispersing rotor has at least a toner particle discharging portion for discharging outside the main casing,
The first space provided between the inner wall of the main body casing and the outer wall of the cylindrical guide means is a space for guiding the finely pulverized product and the surface-modified particles to the classification rotor. And the second space is a space for treating the finely pulverized product from which the fine powder and the ultrafine powder have been removed and the surface-modified particles with a dispersion rotor,
In the surface reforming apparatus, the finely pulverized material charged into the main body casing from the charging portion is introduced into the first space, and the classification means removes fine powder and ultrafine powder having a predetermined particle size or less to remove the fine powder. The finely pulverized product from which fine powder and ultrafine powder have been removed while being continuously discharged is moved to the second space, and the surface of the finely pulverized product is subjected to surface modification treatment by the dispersion rotor. The classification and the surface modification treatment are repeated by circulating the finely pulverized product containing the surface-modified particles to the first space and the second space, whereby fine powder and ultrafine powder having a predetermined particle size or less are obtained. 2. The toner production method according to claim 1, wherein the toner particles are removed in a predetermined amount or less and surface-modified.   3. The toner manufacturing method according to claim 1, wherein the plurality of unevenness provided on the surface of the dispersing hammer facing the liner has a corrugated shape. 4.   The toner manufacturing method according to claim 3, wherein the plurality of unevenness provided on the surface of the dispersing hammer facing the liner has a triangular shape.   The surface of the dispersion hammer facing the liner has a plurality of convex portions and concave portions formed between the convex portions and the convex portions, and the convex portions and the convex portions 5. The toner according to claim 1, wherein a repetitive distance is 2.0 mm or more and 8.0 mm or less, and a depth h of the concave portion is 2.0 mm or more and 8.0 mm or less. Production method.   6. The method for producing a toner according to claim 1, wherein the surface of the dispersing hammer and / or liner is coated with a chromium alloy plating containing at least chromium carbide. The surface-modified toner particles have a weight average particle diameter D4 of 3.5 to 9.0 μm and a ratio of particles having a particle diameter of 4.00 μm or less of 5 to 40% by number,
The surface-modified toner particles have a circle equivalent diameter of 0.6 μm or more and 2 μm in the number-based particle size distribution of the circle equivalent diameter of 0.6 μm or more and 400 μm or less measured by a flow type particle image measuring apparatus. The method for producing a toner according to any one of claims 1 to 6, wherein the proportion of the toner particles less than 0 is 0 to 10% by number. In the toner particles of 2 μm or more of the toner particles that are the surface modified particles obtained by the batch type surface modifying apparatus, the following formula (1)
Average circularity a = L ₀ / L (1)
[In the formula, L ₀ represents the perimeter of a circle having the same projected area as the particle image, and L represents a particle image when image processing is performed at an image processing resolution of 512 × 512 (pixels of 0.3 μm × 0.3 μm). The perimeter of is shown. The method for producing a toner according to any one of claims 1 to 7, wherein the average circularity a obtained from the formula is 0.935 to 0.980.   9. The method for producing toner according to claim 8, wherein the surface-modified toner particles have an average circularity a of 0.940 to 0.980.

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