JP4455361B2 - Toner production method - Google Patents

Description

  The present invention relates to a toner production method, and relates to an improvement in a release agent dispersion technique for rapidly producing a toner having excellent electrophotographic characteristics in which a release agent is finely and uniformly dispersed in the toner.

  As a method for producing toner particles used in electrophotography, there has been proposed a method for producing polymerized toner particles in which a polymerizable monomer is dispersed in the form of droplets and polymerization is performed to directly obtain toner particles. For example, in the method for producing toner particles by suspension polymerization, a polymerizable monomer, a colorant, a release agent, a polymerization initiator, and a cross-linking agent, a charge control agent and other additives are uniformly added as necessary. After dissolving or dispersing to obtain a polymerizable monomer composition, this is dispersed in an aqueous medium containing a dispersion stabilizer using an appropriate stirrer, and a polymerization reaction is performed to obtain a desired particle size. A suspension of polymerized toner particles is obtained. If necessary, a suspension of the polymerized toner particles is treated with an acid or alkali to remove the dispersion stabilizer, and then the aqueous medium is separated in a solid-liquid separation step to obtain toner particles.

  Polymerized toner particles obtained by such a method have a spherical or nearly spherical shape and a uniform surface, so that fluidity and transferability are good, and good development characteristics are exhibited even after many continuous developments. The toner particles are characterized by little stress on the toner particles and little filming on the photoreceptor. Further, since the method does not include a pulverization step, the toner particles obtained can be obtained in a high yield even when a classification step is required because the particle size distribution of the obtained toner particles is sharp.

  Further, in order to improve the toner fixing property and the toner offset resistance when transferring as a toner image from a photoreceptor onto a transfer material such as paper, a release agent such as wax is added to the toner particles. Polymerized toner particles obtained by the polymerization method can be blended in a large amount, and can be encapsulated in the polymerized toner particles, so that good fixing properties and offset resistance can be obtained.

  If a wax having a low melting point is used as a release agent, the plasticity of the toner is increased even at low temperature fixing, and the fixing property in the low temperature region is improved. On the other hand, when a wax having a high melting point is used, the releasability of the toner from the fixing member at a high temperature is increased, and the fixing property at a high temperature region is improved. Further, two or more kinds of waxes having different melting points can be added in order to have both characteristics in the same toner.

  When a release agent is added to the polymerized toner particles, if the melting point of the release agent is lower than the temperature during the polymerization step, it may be mixed as it is with the raw material composition, but the melting point of the release agent is that during the polymerization step. When the temperature is higher than the temperature, since the release agent is kept in a solid state, a coarse lump of the release agent is generated, and it may be difficult to completely and uniformly encapsulate the toner particles.

  If the added release agent is not encapsulated in the toner particles and a part of the release agent is present as a lump in the state of being released from the toner particles, the fluidity of the entire toner may be lowered even if it is slight. Alternatively, it may cause toner aggregation with a release agent lump as a core, thereby causing deterioration in image quality when a toner image is formed.

  Further, even if the release agent is completely encapsulated in the toner particles, if the distribution state is not uniform, the content of the release agent is different for each toner particle, and the toner particles exhibit different properties. When the image is formed, the image quality may be deteriorated.

  In order to uniformly enclose a release agent having a melting point higher than the polymerization temperature in the toner particles, it has been proposed to use a release agent having a high melting point which is finely powdered or finely dispersed in a liquid medium.

  As a method for producing a fine dispersion of a high melting point release agent, a high melting point release agent is stirred and dispersed in an organic solvent at a temperature equal to or higher than the melting point of the release agent, and then rapidly cooled. A method for producing a fine dispersion has been proposed (see, for example, Patent Document 1).

  In another method, a fine dispersion of a release agent is obtained by ejecting a liquid mixture of a release agent having a high melting point and an organic solvent from a nozzle at high pressure and colliding with a wall surface (for example, Patent Document 2). reference).

  In yet another method, after mixing coarse particles of a high melting point release agent in an organic solvent such as a polymerizable monomer, the coarse particles in the organic solvent are finely pulverized by a stirring mill using a pulverization medium. By doing so, a fine dispersion of the release agent is obtained (for example, see Patent Document 3).

JP-A-6-130723 (page 4) Japanese Patent Laid-Open No. 10-207116 (page 7, FIG. 2, FIG. 3) Japanese Patent Laid-Open No. 6-273777 (page 3-4)

  However, in the above conventional example, the release agent may not be finely dispersed to a particle size small enough to be uniformly encapsulated in the toner particles, or the required time is too long even if finely dispersed. was there. Further, there are problems such as coarse particles of the release agent and aggregates of the release agent due to defective grinding, which adversely affect the particle size distribution of the toner particles.

  Further, there is a problem that developability is deteriorated due to a coarse release agent and an aggregate of release agents which are released without being included in the toner.

  In addition, problems such as deterioration of fixability occur due to the fact that the release agent is not uniformly encapsulated in the toner particles.

  An object of the present invention is to provide a toner manufacturing method that solves the above-described problems.

  Another object of the present invention is to provide a new method for producing toner which is finely and uniformly contained in toner particles in a method for producing toner particles including a step of dispersing a release agent in a liquid medium. It is in.

  Another object of the present invention is to provide a new method for producing toner particles having excellent image characteristics and fixability.

As a result of intensive studies to solve the above problems, the present inventors have found that the release agent in the liquid medium is finely dispersed with a sufficiently small and uniform particle size according to the following method. Thus, it has been found that the release agent is uniformly encapsulated in the toner particles. The present invention is characterized by the following inventions.
( 1 ) A toner production method including a release agent dispersion step, a granulation step and a polymerization step ,
The release agent dispersion step, a release agent is mixed in a polymerizable monomer, a step of crushing the release agent with a stirring device to prepare a release agent dispersion liquid having a high-speed shearing force,
The stirring device is provided with a stirring chamber formed by a high speed rotating screen around the stirring blades and the stirring拌羽roots high speed in the stirring拌羽root and backward,
The stirrer is provided in a container, and the release agent dispersion liquid is ejected from the discharge port provided in the screen into the container, and the introduction and discharge of the release agent dispersion liquid into the container are repeated. And a method for producing the toner , wherein the release agent dispersion is circulated .
(2) In the above release agent dispersion step, method for producing a toner according to (1) that the temperature of the release agent dispersion liquid is maintained at 60 ° C. or less.
( 3 ) When the peripheral speed of the stirring blade is A and the peripheral speed of the screen is B,
15 m / s ≦ A ≦ 60 m / s, 15 m / s ≦ B ≦ 60 m / s
The toner production method as described in (1) or ( 2) above, wherein
( 4 ) When the peripheral speed of the stirring blade is A and the peripheral speed of the screen is B, the relative peripheral speed “A + B” is
40 m / s ≦ A + B ≦ 80 m / s
( 3 ) The toner production method according to ( 3 ), wherein
( 5 ) In the release agent dispersion step, the release agent is pulverized to a volume-based median diameter of 250 μm or less in a liquid containing a polymerizable monomer as preliminary pulverization (1) to ( 4 ) The method for producing a toner according to any one of the above.
( 6 ) The method for producing a toner according to any one of (1) to ( 5 ), wherein the releasing agent has a melting point of 80 ° C. or higher and a penetration at 25 ° C. of 10 or lower. .
( 7 ) including a preparation step of adjusting the polymerizable monomer composition by adding at least a colorant and a polymerization initiator to the release agent dispersion obtained by the release agent dispersion step, The method for producing a toner according to any one of (1) to ( 6 ), wherein a second release agent having a melting point lower than 80 ° C. is added.

  According to the present invention, the release agent is finely dispersed with a sufficiently small and uniform particle size, so that the release agent can be uniformly encapsulated in the toner particles. Further, toner particles having an excellent particle size distribution can be produced by reducing the coarse release agent. Further, toner particles having improved fixability and image characteristics in a high temperature region can be produced in a short time and with a simple operation.

The present invention relates to polymerization in a polymerizable monomer composition containing a dispersion of a release agent finely dispersed in a liquid medium (hereinafter also referred to as “release agent dispersion”) and a polymerizable monomer. The toner particles can be produced by polymerizing the polymerizable monomer.
Further, the present invention can be constituted by a process of producing toner particles by aggregating polymer particles in the presence of a release agent finely dispersed in a liquid medium.
Further, the present invention performs granulation in an aqueous medium in the presence of a release agent dispersion and a polymerizable monomer, and polymerizes the polymerizable monomer in the generated polymerizable monomer composition. Thus, the toner particles can be produced by a process.
The present invention also includes a step of preparing a polymerizable monomer composition containing a release agent dispersion and a polymerizable monomer, and a step of granulating the polymerizable monomer composition in an aqueous medium. And a step of producing toner particles by polymerizing a polymerizable monomer in a polymerizable monomer composition dispersed in an aqueous medium.
In the present invention, the aqueous medium refers to a medium containing at least 50% by weight of water.

  A stirring device preferably used in the present invention will be described with reference to FIG. 1 and an enlarged view of the stirring device will be described with reference to FIG. A dispersion system in which the stirring device is incorporated in a circulation path will be described with reference to FIG. However, the disperser used in the present invention is not limited to this.

  1, 2, and 3, 1 is a stirring blade that rotates at high speed, 2 is a screen that rotates around the stirring blade 1 in a direction opposite to the stirring blade 1, and 3 is formed by the stirring blade 1 and the screen 2. Stirring chambers 3, 4 are dispersion vessels, 5 is a discharge port provided on the screen 2, 6 is a jacket, 7 is a holding tank, 8 is a stirring blade, 9 is a circulation pump, 10 is a dispersion vessel inlet, and 11 is a suction port. , 12 is a discharge port, 13 is a heat exchanger, 14 is a flow meter, 15 is a pressure regulating valve, 16 is a lower motor, 17 is an upper motor, 18 is a lid, 19 is a support cylinder, 20 is an upper rotating shaft, 21 Is a mechanical seal, 22 is an upper housing, 23 is a partition plate, 24 is a lower rotating shaft, 25 is a pressure gauge, and 26 is a thermometer.

(About the stirring device of FIGS. 1 and 2)
The release agent mixed liquid (liquid in which the release agent is mixed in the liquid medium) charged into the dispersion container 4 is placed inside the portion of the stirring chamber 3 where the discharge port 5 is provided. By rotating at high speed, a shearing force is received in a minute gap between the inner wall of this part and the blade tip, and the release agent is minutely pulverized. Further, every time the discharge port 5 of the stirring chamber 3 rotating in the reverse direction through the minute gap between the blade tips passes in front of the blade tips, the release agent dispersion liquid is sheared between them. Done.

  And since this discharge port 5 rotates in the direction opposite to the rotation direction of the stirring blade 1, the relative rotational speed of both can be increased, and the shearing force applied to the release agent dispersion can be increased. it can. Thereby, it is possible to pulverize the mold release agent more finely than before.

  Furthermore, since the portion provided with the discharge port 5 in the stirring chamber 3 rotates in the direction opposite to the rotation direction of the stirring blade 1, the fluid discharge position changes with the rotation, and in the dispersion container 4. The release agent dispersion circulates well. Further, since the diameter of the portion provided at the discharge port in the stirring chamber 3 becomes smaller as it goes downward, the peripheral speed of rotation is large in the upper portion having a larger diameter, and the rotation is performed in the lower lower portion. The peripheral speed is small. As a result, when the fluid is discharged from the discharge port 5, the circumferential speed given to the fluid is different in the upper and lower directions, and the circulation of the release agent dispersion is further promoted by the flow having different speed differences. .

  In addition, since this flow is added to the discharge flow caused by the rotation of the stirring blade 1 that rotates with a small gap from the discharge port 5, a faster discharge flow can be obtained, and the entire circulation is further promoted. . By such good circulation, the opportunity for the release agent dispersion liquid to pass through the above-mentioned minute gaps increases, the pulverization unevenness decreases, and the release agent can be uniformly pulverized.

  In addition, the dispersion container 4 has a jacket structure. By flowing a cooling medium in the jacket 6, the temperature of the release agent dispersion that has risen due to shear inside the dispersion container can be lowered.

(About the distributed system in Fig. 3)
The release agent dispersion liquid charged in the holding tank 7 and mixed by the stirring blades 8 installed in the holding tank 7 is supplied from the dispersion container inlet 10 through the circulation pump 9 and introduced into the suction port 11. . Next, the release agent dispersion introduced from the suction port 11 passes through the above-described minute gap and is discharged from the discharge port 5. The discharged release agent dispersion liquid circulates in the dispersion container 4, is then discharged from the discharge port 12, and returns to the holding tank 7 via the heat exchanger 13. The circulation in which the release agent dispersion liquid returned to the holding tank 7 is again introduced into the dispersion container inlet 10 is repeated. By repeating the circulation of the cycle between the disperser and the holding tank 7, the release agent is crushed uniformly and efficiently.

  The processing flow rate is measured by a flow meter 14 installed in the circulation path. Further, it is possible to apply a back pressure by the pressure adjusting valve 15. By applying the back pressure, it becomes possible to suppress the occurrence of cavitation due to the rotation of the stirring blade 1 and the screen 2, and it is possible to further apply a shearing force to the treatment liquid. As a result, the release agent can be more finely and uniformly crushed, and therefore, back pressure can be suitably applied in the present invention.

  When the circulation path is used, since the circulation of the cycle between the disperser and the holding tank is added to the above-described good circulation in the dispersion vessel 4, the release agent can be crushed more uniformly and efficiently. It can be used preferably in the present invention.

  As the above-mentioned disperser, for example, Creamix W-Motion (manufactured by M Technique Co., Ltd.) can be preferably used, but not limited thereto.

  In the present invention, the temperature of the release agent dispersion is preferably 60 ° C. or lower. When deviating from this range, as the temperature rises, the release agent begins to dissolve (especially preferentially dissolves from low molecular weight components), and the release agent precipitates in a later manufacturing process, resulting in very cohesive properties. High mold release agent may be generated. Further, a release agent having high cohesiveness serves as a nucleus, and even a release agent that has not been dissolved and has been refined is not preferable because it may improve the cohesiveness.

  As means for keeping the release agent dispersion at 60 ° C. or lower, a cooling medium can be flowed into the jacket 6 of the dispersion vessel 4 and the heat exchanger 13 shown in FIG. 3 can be used. Absent.

The peripheral speed of the stirring blade and the screen of the dispersion apparatus in the present invention is the peripheral speed of the maximum diameter of the stirring blade and the screen.
Further, when the peripheral speed of the stirring blade of the dispersing device described above is A and the peripheral speed of the screen is B, the release agent is within the range of 15 m / s ≦ A ≦ 60 m / s and 15 m / s ≦ B ≦ 60 m / s. It is preferable to perform crushing. When the peripheral speed of each of the stirring blade 1 and the screen 2 is smaller than 15 m / s, it cannot be finely dispersed in a sufficiently small and uniform particle size so that the release agent is uniformly included in the toner particles. On the other hand, when the peripheral speed exceeds 60 m / s, the release agent dispersion liquid is excessively heated, so that the release agent is dissolved, which is not preferable. Moreover, when excessive temperature rise is suppressed using the above-mentioned cooling means, since the load to a cooling means will increase, it is unpreferable.

  Further, in the present invention, when the peripheral speed of the stirring blade is A and the peripheral speed of the screen is B, the relative peripheral speed “A + B” is 40 m / s ≦ A + B ≦ 80 m / s. It is preferable from the viewpoint of balancing the above.

  In the present invention, in the release agent dispersion step, the release agent is preferably adjusted to a volume-based median diameter of 250 μm or less in a liquid containing a polymerizable monomer as pre-grinding. Within the above range, since the release agent can efficiently enter the minute gap between the inner wall of the portion provided at the discharge port of the stirring chamber and the blade tip, the pulverization efficiency can be further improved.

  Specific apparatuses used for the preliminary pulverization include those having a large shearing force among ordinary stirring blades such as turbine blades and edged turbine blades, Ultra Turrax (manufactured by IKA), T.W. K. Homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) K. Dispersers such as Philmix (made by Special Machine Industries), Claremix (made by M Technique) are used. A continuous disperser such as Ebara Milder (Ebara Seisakusho) or Cavitron (Eurotech) may also be used. These can be used in one pass, or can be used by passing a plurality of times through a circulation line.

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

  The toner of the present invention is a fine polymer particle obtained by emulsion polymerization of monomers in various polymerization methods such as dispersion polymerization, emulsion polymerization, suspension polymerization, etc., and a liquid to which an emulsion of necessary additives is added. After that, an organic solvent, a flocculant, etc. are added, and it can manufacture by the method of associating with the mold release agent in a mold release agent dispersion liquid. A method of preparing by mixing with a dispersion such as a colorant necessary for the constitution of the toner at the time of association, and a polymerizable monomer containing a release agent dispersion, a polymerizable monomer and a colorant And a method of emulsion polymerization of the body composition. Here, the association means that a plurality of resin particles and colorant particles are fused.

  Although it does not specifically limit as a manufacturing method of a suspension polymerization method, The following manufacturing methods can be raised.

  A release agent dispersion is obtained by crushing the release agent in the liquid using the stirring device having the above-described high-speed shearing force. Next, various constituent materials such as a colorant, a charge control agent, and a polymerization initiator are added to the polymerizable monomer, and the polymerizable monomer is mixed with a homogenizer, sand mill, sand grinder, ultrasonic disperser, etc. Various constituent materials are dissolved or dispersed in the body to obtain a colorant dispersion. This release agent dispersion and colorant dispersion are dissolved and mixed in the preparation step, and the resulting polymerizable monomer composition is used in an aqueous medium containing a dispersion stabilizer using a homomixer or a homogenizer. Disperse in oil droplets of a desired size as a toner (granulation step). Then, it transfers to the reaction apparatus which has a stirring mechanism, and advances a polymerization reaction by heating (polymerization process). After completion of the reaction, the dispersion stabilizer is removed, filtered, washed, and dried to produce the toner of the present invention.

  Further, as a method for producing the toner of the present invention, a method of adjusting the resin particles by fusing them in an aqueous medium can also be mentioned. This method is not particularly limited, and examples thereof include the following methods. That is, the resin particles or resin particles generated in the liquid, the colorant refined in the liquid, the release agent crushed in the liquid using the above-described stirring device having high-speed shearing force, and the like. A method of associating a plurality of fine particles composed of various material particles or resin, release agent, colorant, etc., in particular, after dispersing these in an aqueous medium using an emulsifier, a flocculant having a critical coagulation concentration or higher is added. In addition, the toner of the present invention can be formed by salting out and heating and fusing at a temperature equal to or higher than the glass transition temperature of the formed polymer itself, and filtering and drying the resulting toner particles. Here, an organic solvent that is infinitely soluble in water may be added simultaneously with the flocculant.

  In the present invention, a so-called seed polymerization method in which a monomer is further adsorbed to the obtained polymer particles and then polymerized using a polymerization initiator can be suitably used in the present invention.

  As the polymerizable monomer suitably used in the present invention, a vinyl polymerizable monomer capable of radical polymerization is used. As the vinyl polymerizable monomer, a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used.

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

  Examples of the polyfunctional polymerizable monomer include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and tripropylene. Glycol diacrylate, polypropylene glycol diacrylate, 2,2'-bis (4- (acryloxydiethoxy) phenyl) propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, tri Ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethyleneglycol Rudimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2′-bis (4- (methacryloxydiethoxy) phenyl) propane 2,2′-bis (4- (methacryloxypolyethoxy) phenyl) propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, divinyl ether and the like.

  In the present invention, the above-mentioned monofunctional polymerizable monomers are used alone or in combination of two or more, or the above-mentioned monofunctional polymerizable monomers and polyfunctional polymerizable monomers are combined, Or a polyfunctional polymerizable monomer is used individually or in combination of 2 or more types. Among the above-mentioned monomers, it is preferable to use styrene or a styrene derivative alone or in combination, or in combination with other monomers from the viewpoints of development characteristics and durability of the toner.

  In the present invention, in the case of a polymerization method using an aqueous medium such as suspension polymerization, the inclusion of a release agent can be promoted by adding a polar resin to the polymerizable monomer composition. it can.

  When a polar resin is present in the polymerizable monomer composition suspended in the aqueous medium, the polar resin moves to the vicinity of the interface between the aqueous medium and the polymerizable monomer composition due to the difference in affinity for water. Therefore, the polar resin is unevenly distributed on the surface of the toner particles. As a result, the toner particles have a core-shell structure, and the inclusion property of the release agent is improved even when a large amount of the release agent is contained.

  In addition, if a resin with a high melting temperature is selected as the polar resin used for the shell, even if the binder resin is designed to be melted at a lower temperature for the purpose of fixing at low temperature, it may cause problems such as blocking during storage. Can be suppressed.

  As such a polar resin, since the fluidity of the polar resin itself can be expected when the shell is formed unevenly distributed on the surface of the toner particles, a saturated or unsaturated polyester resin is particularly preferable.

  As said polyester-type resin, what carried out the condensation polymerization of the acid component monomer and alcohol component monomer which are mentioned below can be used. Acid monomers include terephthalic acid, isophthalic acid, phthalic acid, fumaric acid, maleic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, camphor An acid, cyclohexane dicarboxylic acid, trimellitic acid, etc. are mentioned.

  Examples of the alcohol component monomer include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-bis (hydroxy Examples include alkylene glycols such as methyl) cyclohexane and polyalkylene glycols, bisphenol A, hydrogenated bisphenol, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, glycerin, trimethylolpropane, pentaerythritol, and the like.

  As the release agent used in the present invention, a wax in a solid state at room temperature may be used in terms of toner blocking resistance, durability of a large number of sheets, low-temperature fixability, and offset resistance.

  Examples of the wax include polymethylene wax such as paraffin wax, polyolefin wax, microcrystalline wax and Fischer-Tropsch wax, amide wax, higher fatty acid, long chain alcohol, ester wax and derivatives thereof such as graft compounds and block compounds. These are preferably removed from the low molecular weight component and have a sharp maximum endothermic peak in the endothermic curve obtained by a differential scanning calorimeter.

  Among these, the wax preferably used has a melting point represented by a maximum endothermic peak obtained by a differential scanning calorimeter of 80 ° C. or higher. In the case of a wax having a melting point of less than 80 ° C., the wax once finely dispersed causes thermal aggregation depending on the polymerization temperature during the polymerization process, and the particle size of the release agent particles dispersed in the toner particles may increase. This is not preferable. The melting point is a measurement temperature range of 30 to 200 ° C., a temperature increase rate of 10 ° C./min, and a DSC curve in a temperature range of 30 to 200 ° C. is obtained by a second temperature increase process in a normal temperature and humidity environment. The temperature of the endothermic main peak of the obtained DSC curve can be measured using, for example, MDSC-2920 (manufactured by TA Instruments) which is a differential scanning calorimeter (DSC).

  Moreover, it is preferable that the mold release agent used for this invention is a thing with a penetration of 10 or less at 25 degreeC when measured according to the test method prescribed | regulated to JISK2235 (1991). In the case of a mold release agent having a penetration of greater than 10 at 25 ° C., the brittleness is insufficient, so that in the coarse dispersion step, sufficient dispersion can be achieved with a simple dispersion device such as the above-described stirring device having high shearing force. This is not preferable because it cannot be performed, and it is necessary to use a large-scale apparatus such as a high-pressure disperser or a complicated operation such as an operation of heating and melting and then cooling.

  To the toner particles produced according to the present invention, a second release agent having a melting point lower than 80 ° C. can be used in combination in order to increase the plasticity of the toner particles and improve the fixability in the low temperature region. The melting point of the second release agent is also represented by the melting point represented by the maximum endothermic peak obtained by the differential scanning calorimeter.

  As the second release agent, a linear alkyl alcohol having 15 to 100 carbon atoms, a linear fatty acid, a linear acid amide, a linear ester, or a montan derivative wax is preferably used. It is more preferable that impurities such as liquid fatty acid have been previously removed from these waxes.

  In order to improve the translucency of the image fixed on the OHP, a linear ester wax is particularly preferably used as the second release agent.

  The linear ester wax is preferably contained in an amount of 1 to 40 parts by mass, more preferably 4 to 30 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  As the colorant used in the present invention, a black colorant that is toned in black using carbon black, a magnetic material, and the following yellow / magenta / cyan colorant is used.

  As the yellow colorant, compounds typified 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, 109, 110, 111, 128, 129, 147, 168, etc. are preferably used.

  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, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254 are particularly preferred.

  As the cyan colorant, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 and the like can be used particularly preferably.

  These colorants can be used alone or in combination and further in the form of a solid solution. The colorant of the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. The colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the resin.

  When a magnetic material is used as the black colorant, 40 to 150 parts by mass are added to 100 parts by weight of the resin, unlike other colorants.

  As the charge control agent used in the present invention, known ones can be used. However, a charge control agent that is colorless, has a high toner charging speed, and can stably maintain a constant charge amount is preferable. Further, when the direct polymerization method is used in the present invention, a charge control agent having no polymerization inhibition and no solubilized product in an aqueous system is particularly preferable. Specific examples of the negative compounds include salicylic acid, naphthoic acid, dicarboxylic acid metal compounds, sulfonic acid, polymer compounds having carboxylic acid in the side chain, boron compounds, urea compounds, silicon compounds, calixarene, and the like. As a positive system, a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, an imidazole compound, and the like are preferably used. The charge control agent is preferably 0.5 to 10 parts by mass with respect to 100 parts by weight of the resin. However, in the present invention, it is not essential to add a charge control agent. When a two-component development method is used, frictional charging with a carrier is used, and even when a non-magnetic one-component blade coating development method is used, the blade It is not always necessary to include a charge control agent in the toner by actively utilizing frictional charging with the member or the sleeve member.

  In order to polymerize the polymerizable monomer, a polymerization initiator can be used. Examples of the polymerization initiator that can be used in the present invention include azo polymerization initiators. As the azo polymerization initiator, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile) ), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobismethylbutyronitrile, and the like.

  An organic peroxide initiator can also be used. Organic peroxide initiators include benzoyl peroxide, lauroyl peroxide, di-α-cumyl peroxide, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, bis (4-t-butyl) (Cyclohexyl) peroxydicarbonate, 1,1-bis (t-butylperoxy) cyclododecane, t-butylperoxymaleic acid, bis (t-butylperoxy) isophthalate, methyl ethyl ketone peroxide, tert-butylperoxy Examples include 2-ethylhexanoate, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, and the like.

  A redox initiator in which an oxidizing substance and a reducing substance are combined can also be used. Examples of the oxidizing substance include inorganic peroxides such as hydrogen peroxide and persulfates (sodium salts, potassium salts, ammonium salts, etc.), and oxidizing metal salts such as tetravalent cerium salts. Reducing substances include reducing metal salts (divalent iron salts, monovalent copper salts, trivalent chromium salts, etc.), ammonia, lower amines (amines having about 1 to 6 carbon atoms such as methylamine and ethylamine). Amino compounds such as hydroxylamine, sodium thiosulfate, sodium hydrosulfite, sodium hydrogen sulfite, sodium sulfite, sodium formaldehyde sulfoxylate and other reducing sulfur compounds, lower alcohols (about 1 to 6 carbon atoms), ascorbic acid or Examples thereof include salts and lower aldehydes (about 1 to 6 carbon atoms).

  The polymerization initiator is selected with reference to a 10-hour half-life temperature, and is used alone or in combination. Although the addition amount of the said polymerization initiator changes with the target degree of polymerization, generally 0.5-20 mass parts is added with respect to 100 mass parts of polymerizable monomers.

  In order to control the degree of polymerization, a known chain transfer agent, polymerization inhibitor or the like can be further added and used.

  In the present invention, for example, when a polymerizable monomer is polymerized, various crosslinking agents can be used. Examples of the crosslinking agent include divinylbenzene, 4,4′-divinylbiphenyl, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, glycidyl (meth) acrylate, and trimethylolpropane tri (meth) acrylate. Examples include functional compounds.

  In the polymerized toner according to the present invention, particularly when using suspension polymerization using a dispersant, the dispersant used is an inorganic compound such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate. , Magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina and the like. As organic compounds, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, polyacrylic acid and its salts, starch and the like can be dispersed in an aqueous phase. These stabilizers are preferably used in an amount of 0.2 to 20 parts by weight with respect to 100 parts by weight of the polymerizable monomer.

  Among these stabilizers, when an inorganic compound is used, a commercially available one may be used as it is, but in order to obtain fine particles, the inorganic compound may be produced in a dispersion medium. For example, in the case of tricalcium phosphate, a sodium phosphate aqueous solution and a calcium chloride aqueous solution may be mixed under high stirring.

  Moreover, you may use 0.001-0.1 mass part surfactant for fine dispersion | distribution of these stabilizers. This is to promote the desired action of the above dispersion stabilizer, and specific examples thereof include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, lauric acid. Examples thereof include sodium, potassium stearate, calcium oleate and the like.

  In the production method of the present invention, an external additive can be used for the purpose of imparting various properties to the toner. The external additive preferably has a particle size of 1/10 or less of the average particle size of the toner particles from the viewpoint of durability when added to the toner. Examples of the external additive include aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, tin oxide, zinc oxide and other metal oxides, nitrides such as silicon nitride, carbides such as silicon carbide, Inorganic metal salts such as calcium sulfate, barium sulfate and calcium carbonate, fatty acid metal salts such as zinc stearate and calcium stearate, carbon black, silica and the like are used.

  These external additives are used in an amount of 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, based on 100 parts by weight of toner particles. The external additives may be used alone or in combination of two or more, but it is more preferable to use a hydrophobized one.

  The toner produced according to the present invention can be used for both a one-component developer and a two-component developer. The toner produced in the present invention is used for image formation by an appropriate method according to the type. For example, in the case of a magnetic toner containing a magnetic material in a toner particle as a one-component developer, the magnetic toner is conveyed using a magnet built in the developing sleeve when an image is formed using the magnetic toner. A method of charging is used. When non-magnetic toner containing no magnetic material is used, during image formation using this non-magnetic toner, for example, a blade and a fur brush are used to forcibly frictionally charge the developing sleeve, and the toner is placed on the sleeve. The method of conveying by attaching is used.

  On the other hand, when the toner obtained by the production method of the present invention is used as a commonly used two-component developer, it is used as a developer using a carrier together with the toner. The carrier used in the present invention is not particularly limited, but particles containing single or composite ferrite mainly composed of iron, copper, zinc, nickel, cobalt, manganese and chromium elements are used.

  From the point that saturation magnetization and electric resistance can be controlled over a wide range, the shape of the carrier is also important. For example, the shape of the carrier is selected from spherical, flat, irregular, etc., and the fine structure of the surface state of the carrier, for example, It is preferable to control the surface roughness.

  As the carrier, generally, a resin-coated carrier obtained by baking and granulating the above metal compound to produce carrier core particles and coating the resin thereon is used. In order to reduce the load on the substrate, suspension polymerization of the low-density dispersion carrier obtained by kneading the magnetic material and resin, followed by pulverization and classification, and also the kneaded product of the metal compound and the monomer directly in an aqueous medium Polymerized carriers obtained by dispersing in a spherical shape can also be used as the carrier. The carrier core particles can be used for the carrier.

  The average particle size of these carriers is 10 to 100 μm, more preferably 20 to 50 μm.

  When the two-component developer is prepared, the mixing ratio of the carrier and the toner produced in the present invention is 2% by mass to 15% by mass, preferably 4% by mass to 13% by mass as the toner concentration in the developer. Usually good results are obtained. When the toner concentration is less than 2% by mass, the image density is low and practical use is difficult. When the toner concentration exceeds 15% by mass, fogging and scattering in the apparatus increase, and image deterioration and developer consumption may occur.

First, in the present invention, 1. 1. Evaluation method of dispersibility of release agent dispersion 2. Toner granulating evaluation method 3. Toner image density evaluation method The fixability evaluation method will be described below.

1. Method for evaluating dispersibility of release agent dispersion The evaluation of dispersibility of a release agent dispersion is based on a volume-based particle size distribution using a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by Horiba, Ltd.). This was done by determining the proportion of particles having a particle size of 3 μm or less.
When the ratio of particles of 3 μm or less exceeds 80%, good dispersibility is exhibited. When the ratio is 60% or more and less than 80%, there are some problems in image characteristics and fixability, but there is no problem in practical use. Dispersibility that is unfavorable on the product is very severe on the image.

[Dispersibility (ratio of particles of 3 μm or less)]
Over 80% ... A: Good 60% or more, less than 80% ... B: Slightly inferior (no problem in practical use)
Less than 60% ... C: Evil

2. Method for evaluating the granulation property of the toner As for the granulation property in the granulation step, a part of the slurry after polymerization is sampled, further washed and dried, and the number variation coefficient measured by Coulter Multisizer (manufactured by Coulter Co.) is used. Examined. When the number variation coefficient is less than 35%, good granulation properties are exhibited. When the coefficient of variation is 35% or more and less than 40%, there is a slight problem with the image, but there is no problem in practical use. The effect is quite severe and the product exhibits undesirable granulation properties.
The Coulter Multisizer is connected to an interface (manufactured by Nikka) and a PC9801 personal computer (manufactured by NEC) that outputs a number average distribution and volume average distribution, and a 1% NaCl aqueous solution is prepared using first grade sodium chloride as the electrolyte. To do.
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 process for about 1 to 3 minutes with an ultrasonic disperser, and the particle size distribution of particles of 2 to 40 μm on the basis of the number is used with the Coulter Multisizer using a 100 μm aperture as the aperture. Measure and then determine various values.
The coefficient of variation in the number distribution is calculated from the following equation.
Coefficient of variation (%) = [S / D1] × 100
(In the formula, S represents the standard deviation in the number distribution of toner particles, and D1 represents the number average particle diameter (μm) of toner particles.)

[Number variation coefficient]
Less than 35% ··· A: Good 35% or more and less than 40% ··· B: Slightly inferior (no product problems)
40% or more ・ ・ ・ ・ C: Poor

3. Evaluation Method of Toner Image Density To 100 parts by mass of the toner obtained after drying, 1.7 parts by mass of hydrophobic silica having a specific surface area of 200 m ² / g by the BET method was externally added to obtain a toner. Using this developer, image formation was performed in a 30 ° C./80% RH environment using a modified CREATIVE PROCESSOR 2150 (manufactured by Canon).
The obtained image was subjected to reflection density measurement using an SPI filter of Macbeth RD918 type (the same is true for the subsequent image density measurement methods). The results are shown in Table 1. As an evaluation standard, when the Macbeth density value is 1.2 or more, a good image density is shown. When the Macbeth density value is 1.0 or more and less than 1.2, there is a slight problem in the image, but there is no practical problem. If it is less than 1, the influence on the image is considerably severe, and an image density unfavorable on the product is exhibited.

[Macbeth concentration value]
1.2 or more ··· A: Good 1.0 or more and less than 1.2 ··· B: Slightly inferior (no problem in product)
<1.0 ・ ・ ・ ・ C ： Poor

4). Fixability Evaluation Method Toner is produced by the same method as the image density evaluation method, and an unfixed image with a toner loading amount of 0.55 mg / cm ² on paper is prepared using a modified CREATIVE PROCESSOR 2150 (Canon). Using the same thermal roller fixing device, fixing was performed under the conditions of a paper feed speed of 100 mm / s and a roller load of 392 N. The evaluation was performed by visually observing the state of the offset when the unfixed image was fixed by swinging the roller temperature in the range of 140 ° C. to 220 ° C. every 9 ° C. for 9 points. For evaluation, plain paper of 64 g / m ² was used.

[Fixing temperature range where no offset occurs]
<140-220 ° C./all 9 points>: 5 points or more: A good
: 3 to 4 points ··· B slightly inferior
(No problem in practical use)
: 2 points or less ・ ・ ・ ・ C Evil

  Next, production examples of the release agent dispersion are described below.

[Production Example of Release Agent Dispersion 1]
The release agent was dispersed using the dispersing apparatus shown in FIGS.
-Styrene 26 parts by mass-Fischer-Tropsch wax 4 parts by mass (average molecular weight: 708, melting point: 110.2 ° C, penetration: 1)
The above components were put into the dispersion container described in FIGS. 1 and 2, and the release agent was crushed under the following conditions to obtain a release agent dispersion 1.
Rotor circumferential speed: 30m / s
Screen peripheral speed: 30m / s
Dispersion time: 40 min

At this time, the temperature rise of the release agent dispersion was suppressed by flowing cooling water through the jacket. The temperature of the release agent dispersion after the completion of dispersion was 32 ° C.
The evaluation results of the dispersibility of the release agent dispersion 1 are shown in Table 1.

[Production Example of Release Agent Dispersion 2]
As preliminary pulverization, the following components are charged into a temperature-controllable container, and the temperature of the liquid is always kept at 50 ° C. or lower using Ultra Turrax T-50 (manufactured by IKA) and stirred for 40 minutes at 10,000 rpm and separated. A crude mold dispersion was obtained.
-Styrene 26 parts by mass-Fischer-Tropsch wax 4 parts by mass (average molecular weight: 708, melting point: 110.2 ° C, penetration: 1)

The volume average median diameter of the release agent in the obtained release agent crude dispersion was 20.8 μm.
Next, the obtained release agent crude dispersion is put into a dispersion container of the dispersion apparatus of the embodiment shown in FIGS. 1 and 2, and the release agent is crushed under the following conditions. Got.
Rotor circumferential speed: 30m / s
Screen peripheral speed: 30m / s
Dispersion time: 40 min

At this time, the temperature rise of the release agent dispersion was suppressed by flowing cooling water through the jacket. The temperature of the release agent dispersion after the completion of dispersion was 33 ° C.
The evaluation results of the dispersibility of the release agent dispersion 2 are shown in Table 1.

[Production Example of Release Agent Dispersion 3]
A release agent dispersion 3 was produced with the same apparatus, conditions and components as in the production example of the release agent dispersion 1 except that the peripheral speed of the rotor was 15 m / s and the peripheral speed of the screen was 15 m / s. . The temperature of the release agent dispersion after the completion of dispersion was 25 ° C.
The evaluation results of the dispersibility of the release agent dispersion 3 are shown in Table 1.

[Production Example of Release Agent Dispersion 4]
A release agent dispersion 4 was produced with the same apparatus, conditions and components as in the production example of the release agent dispersion 1 except that the peripheral speed of the rotor was 20 m / s and the peripheral speed of the screen was 20 m / s. . The temperature of the release agent dispersion after the completion of dispersion was 28 ° C.
The evaluation results of the dispersibility of the release agent dispersion 4 are shown in Table 1.

[Production Example of Release Agent Dispersion Liquid 5]
A release agent dispersion 5 was produced with the same apparatus, conditions and components as in the production example of the release agent dispersion 1 except that the peripheral speed of the rotor was 60 m / s and the peripheral speed of the screen was 60 m / s. . The temperature of the release agent dispersion after the completion of dispersion was 58 ° C.
The evaluation results of the dispersibility of the release agent dispersion 5 are shown in Table 1.

[Production Example of Release Agent Dispersion 6]
A release agent dispersion 6 was produced with the same apparatus, conditions and components as in the production example of the release agent dispersion 1 except that the peripheral speed of the rotor was 40 m / s and the peripheral speed of the screen was 40 m / s. . The temperature of the release agent dispersion after the completion of dispersion was 43 ° C.
The evaluation results of the dispersibility of the release agent dispersion 6 are shown in Table 1.

[Production Example of Release Agent Dispersion 7]
Except for putting the following components into the dispersion container described in FIGS. 1 and 2, crushing was performed under the same apparatus and conditions as in the production example of the release agent dispersion 1 to produce a release agent dispersion 7.
-Styrene 26 parts by mass-Paraffin wax 4 parts by mass (average molecular weight: 592, melting point: 75 ° C, penetration: 6)
The temperature of the release agent dispersion after the completion of dispersion was 30 ° C.
The evaluation results of the dispersibility of the release agent dispersion liquid 7 are shown in Table 1.

[Production Example of Release Agent Dispersion 8]
As preliminary pulverization, the same components as in the production example of the release agent dispersion 2 are charged into a temperature-adjustable container, and the temperature of the liquid is always 50 ° C. or lower using an Ultra Turrax T-50 (manufactured by IKA). Stirring was carried out at 10,000 rpm for 40 minutes to obtain a release agent crude dispersion. This operation was repeated 4 times to obtain a release agent crude dispersion of the following components in total amount.
・ Styrene 104 parts by mass ・ Fischer-Tropsch wax 16 parts by mass

The volume average median diameter of the release agent in the obtained release agent crude dispersion was 30.2 μm.
Next, the obtained release agent coarsely pulverized liquid was put into a holding tank of the apparatus shown in FIG. 3 and the release agent was crushed under the following conditions to obtain a release agent dispersion 8.
Rotor circumferential speed: 30m / s
Screen peripheral speed: 30m / s
Back pressure: 0.2Mpa
Flow rate: 0.5 L / min
Dispersion time: 80 min

At this time, the temperature rise of the release agent dispersion was suppressed by flowing cooling water through the jacket of the dispersion vessel and using the heat exchanger of FIG. The temperature of the release agent dispersion after completion of dispersion was 30 ° C.
The evaluation results of the dispersibility of the release agent dispersion 8 are shown in Table 1.

[Production Example of Release Agent Dispersion 9]
As preliminary pulverization, the following components are charged into a temperature-controllable container, and the temperature of the liquid is always kept at 50 ° C. or lower using Ultra Turrax T-50 (manufactured by IKA) and stirred for 40 minutes at 10,000 rpm and separated. A crude mold dispersion was obtained.
-Styrene 26 parts by mass-Fischer-Tropsch wax 4 parts by mass (average molecular weight: 708, melting point: 110.2 ° C, penetration: 1)

The volume average median diameter of the release agent in the obtained release agent crude dispersion was 30.1 μm.
Subsequently, the obtained release agent crude dispersion was dispersed at a pressure of 500 kg / cm ² using a high-pressure emulsifier (APV GAULIN HOMOGENIZER 15MR type) to obtain a release agent dispersion 9. The temperature of the release agent dispersion after the completion of dispersion was 55 ° C.
The evaluation results of the dispersibility of the release agent dispersion 9 are shown in Table 1.

  Next, a method for adjusting the colorant dispersion will be described below.

[Coloring agent dispersion process]
Carbon black 15 parts by mass E-88 (manufactured by Orient Chemical Industry Co., Ltd.) 3 parts by mass Styrene 50 parts by mass was dispersed for 3 hours using an attritor (manufactured by Mitsui Miike Chemical Industries) to obtain a colorant dispersion.

  Hereinafter, the present invention will be specifically described based on examples.

Example 1
After adding 140 parts by mass of 0.1 mol / liter-Na ₃ PO ₄ aqueous solution to 225 parts by mass of ion-exchanged water and heating to 60 ° C., it was made 3500 revolutions / minute using CLEARMIX (M Technique Co., Ltd.). And stirred. To this was added 25 parts by mass of a 1.0 mol / liter-CaCl ₂ aqueous solution to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .

Then, as a dispersoid system,
-N-butyl acrylate 24 parts by mass-Saturated polyester resin 7 parts by mass (polycondensate of bisphenol A and terephthalic acid, acid value 10, glass transition point 65 ° C)
Release agent dispersion 1 30 parts by mass Stearyl stearate 12 parts by mass Colorant dispersion 68 parts by weight The above formulation was heated to 60 ° C and dissolved and mixed for 30 minutes. In this, 7 parts by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was put into the aqueous dispersion medium and granulated for 15 minutes while maintaining the rotation speed. Then, the stirrer was changed from the high-speed stirrer to the propeller stirring blade, the internal temperature was raised to 80 ° C., and the polymerization was continued for 10 hours at 50 rpm. After completion of the polymerization, the slurry was cooled, diluted hydrochloric acid was added, and Ca ₃ (PO ₄ ) ₂ was dissolved, followed by filtration, washing with water, crushing and drying to obtain toner particles. To 100 parts by mass of the obtained toner, 1.7 parts by mass of hydrophobic silica having a specific surface area by a BET method of 200 m ² / g was externally added to obtain a toner. The obtained toner was evaluated according to the evaluation method for the dispersibility of the release agent dispersion, toner granulation property, image density, and fixability described above. The results are shown in Table 1.

(Examples 2 to 8)
In the dispersoid system formulation of Example 1, all operations were carried out in the same manner as in Example 1 except that the dispersion was changed as shown in Table 1 to obtain a toner. Table 1 shows the evaluation results of the dispersibility of the release agent dispersion, toner granulation properties, image density, and fixability.

Example 9
A toner was obtained in the same manner as in Example 1 except that 12 parts by mass of stearyl stearate was not used. Table 1 shows the evaluation results of the dispersibility of the release agent dispersion, toner granulation properties, image density, and fixability.

Comparative example

(Comparative Example 1)
In the dispersoid system formulation of Example 1, all operations were carried out in the same manner as in Example 1 except that the dispersion was changed as shown in Table 1 to obtain a toner. Table 1 shows the evaluation results of the dispersibility of the release agent dispersion, toner granulation properties, image density, and fixability.

(Comparative Example 2)
A toner was prepared in the same manner as in Example 1 except that 26 parts by mass of styrene was used instead of the release agent dispersion when preparing the polymerizable monomer composition without preparing a release agent dispersion. Went. Table 1 shows the evaluation results of the dispersibility of the release agent dispersion, toner granulation properties, image density, and fixability.

It is sectional drawing which shows the stirring apparatus provided with the screen which rotates at high speed in the reverse direction to the stirring blade which rotates at high speed. It is an enlarged view of the stirring part of FIG. It is a figure which shows the dispersion | distribution system which incorporated the stirring apparatus in the circulation path.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stirring blade 2 Screen 3 Stirring chamber 4 Dispersion container 5 Discharge port 6 Jacket 7 Holding tank 8 Stirring blade 9 Circulation pump 10 Dispersion container inlet 11 Suction port 12 Discharge port 13 Heat exchanger 14 Flow meter 15 Pressure control valve 16 Lower motor 17 Upper motor 18 Lid 19 Support cylinder 20 Upper rotating shaft 21 Mechanical seal 22 Upper housing 23 Partition plate 24 Lower rotating shaft 25 Pressure gauge 26 Thermometer

Claims (7)

A toner production method including a release agent dispersion step, a granulation step and a polymerization step ,
The release agent dispersion step, a release agent is mixed in a polymerizable monomer, a step of crushing the release agent with a stirring device to prepare a release agent dispersion liquid having a high-speed shearing force,
The stirring device is provided with a stirring chamber formed by a high speed rotating screen around the stirring blades and the stirring拌羽roots high speed in the stirring拌羽root and backward,
The stirrer is provided in a container, and the release agent dispersion liquid is ejected from the discharge port provided in the screen into the container, and the introduction and discharge of the release agent dispersion liquid into the container are repeated. And a method for producing the toner , wherein the release agent dispersion is circulated . The method for producing a toner according to claim 1, wherein in the release agent dispersion step, the temperature of the release agent dispersion is maintained at 60 ° C. or less. When the peripheral speed of the stirring blade is A and the peripheral speed of the screen is B,
15 m / s ≦ A ≦ 60 m / s, 15 m / s ≦ B ≦ 60 m / s
3. The toner production method according to claim 1, wherein the toner production method is within the range. When the peripheral speed of the stirring blade is A and the peripheral speed of the screen is B, the relative peripheral speed "A + B"
40 m / s ≦ A + B ≦ 80 m / s
The toner production method according to claim 3 , wherein the toner production method is within the range of the above. In the release agent dispersion step, in any one of claims 1 to 4, characterized in that allowed to ground in volume median diameter of the release agent in a liquid containing a polymerizable monomer as a pre-ground to 250μm or less A method for producing the toner according to the description. The melting point of the release agent 80 ° C. or higher, method for producing a toner according to any one of claims 1 to 5, characterized in that the penetration at 25 ° C. is 10 or less. A preparation step of adjusting the polymerizable monomer composition by adding at least a colorant and a polymerization initiator to the release agent dispersion obtained by the release agent dispersion step, wherein the melting point is 80 ℃ method for producing a toner according to any one of claims 1 to 6, characterized by adding a smaller second release agent.

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