JP5376959B2 - Method for producing toner particles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a toner particle for removing an organic volatile component in a short period of time in order to reduce damage to a toner and satisfactorily reducing the organic volatile component, in the method of manufacturing the toner particle using a polymerization method. <P>SOLUTION: The method of manufacturing the toner particle is characterized in that, in a volatile component removing process, a toner particle dispersion liquid is drawn out of a vaporization vessel 3 having an external circulation path 9 and, thereafter, returned to the vessel through the external circulation path 9 to circulate the toner particle dispersion liquid wherein a saturated water vapor of 100&deg;C or higher is charged into the circulation path and directly brought into contact with the toner particle dispersion liquid to heat the toner particle dispersion liquid. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a method for producing toner particles contained in toner for developing an electrostatic latent image in an image forming method such as an electrophotographic method, an electrostatic recording method, and a toner jet method.

  The electrophotographic method generally uses a photoconductor made of a photoconductive material, forms an electrostatic latent image on the photoconductor by various means, and then develops the latent image with toner. After forming the toner image and transferring the toner image to a transfer material such as plain paper via an intermediate transfer body or not as necessary, the toner image is formed on the transfer material by heat, pressure, heat and pressure, etc. The toner image is fixed to obtain a copy or printed matter.

  The toner production method is roughly classified into a pulverization method and a polymerization method. For example, in a toner manufacturing method using a pulverization method, at least a binder resin and a colorant are used. If necessary, a charge control agent and a release agent for adjusting the triboelectric charging characteristics of toner particles are added and mixed. Then, after melt-kneading and cooling and solidifying, the kneaded product is refined by a pulverizing means and classified into a desired particle size distribution as necessary to produce toner particles.

  As a polymerization method, there is a method of directly generating toner particles using a suspension polymerization method (see Patent Document 1). In addition, a monomer composition containing a polymerizable monomer, a polymerization initiator, a surfactant, and, if necessary, a crosslinking agent, a chain transfer agent, and other additives, is used in an aqueous medium using a suitable stirrer. The emulsion resin particles having a desired particle size are obtained at the same time, and on the other hand, the colorant is uniformly dispersed in an aqueous medium containing a surfactant and is associated with the emulsion resin particles ( There is an emulsion polymerization method in which toner particles are obtained by aggregation and fusion). The toner particles obtained by these polymerization methods are classified as necessary to be adjusted to a desired particle size distribution.

  The toner particles obtained by these polymerization methods can contain a large amount of a low softening point substance such as wax as a release agent in the toner particles as compared with the pulverization method. There is an advantage of excellent offset resistance.

  On the other hand, in the polymerization step, it is difficult to completely react the polymerizable monomer, and there is a problem that the unreacted polymerizable monomer remains in the toner particles. In particular, in the case of toner particles produced by a suspension polymerization method, a component that may suppress a polymerization reaction, such as a pigment, a charge control agent, and / or a magnetic substance, is contained in the polymerizable monomer composition. Therefore, unreacted polymerizable monomer tends to remain. In particular, when a magnetic material subjected to coupling treatment is used, this tendency tends to be remarkable.

  Moreover, when using a polymerization initiator when manufacturing binder resin, the by-product originating in a polymerization initiator will generate | occur | produce. In some cases, the total amount of by-products may exceed the amount of unreacted polymerizable monomer.

  When a large amount of organic volatile components such as polymerizable monomers and by-products are present in the toner particles, the fluidity of the toner may be lowered to deteriorate the working environment and generate an unpleasant odor. In addition, if a toner having toner particles containing a large amount of organic volatile components is used, when an organic semiconductor is used as the photosensitive member, toner fusion to the photosensitive member is likely to occur, resulting in memory ghosting and image blurring. In some cases, the photosensitive member deteriorates.

  Particularly in recent years, with the miniaturization and personalization of copying machines or printers, restrictions on the apparatus have increased, and the load on the above-mentioned problems has increased. In addition, interest in the environment is increasing, and it is required to reduce the volatile components derived from toner particles generated in the heat and pressure fixing device.

  As a method for reducing the volatile components in the toner particles, the binder resin is not dissolved, but organic volatile components such as polymerizable monomers and / or reaction byproducts are washed with a highly volatile organic solvent. Method; Method of washing with acid or alkali; Method of blending a solvent component or foaming agent that does not dissolve the binder resin into the binder resin and making the resulting toner particles porous to increase the volatilization area of the volatile components inside Is mentioned. However, it is difficult to elute the constituent components of the toner particles, to maintain the solvent component, and to select the solvent. In order to reduce volatile components, it has been proposed to introduce saturated water vapor into the aqueous medium after the polymerization reaction of the toner particles or the binder resin in the aqueous medium (see Patent Document 2). If this method is used, a volatile component can be removed efficiently.

  However, when saturated water vapor is introduced into the aqueous medium, depending on the processed product, foaming may occur violently, limiting the amount of saturated water vapor. As a result, the volatile component removal efficiency was significantly reduced.

  Several methods for removing volatile components while suppressing foaming have been proposed.

  For example, a part of the aqueous dispersion of toner particles in the evaporator is extracted and heated with an external heat exchanger, while the heated aqueous dispersion is decompressed to reduce the liquid phase in the evaporator and the evaporator. It has been proposed to distill off volatile organic compounds while suppressing foaming by ejecting from the top (see Patent Document 3).

  However, when an external heat exchanger is used, there is a possibility that problems such as blockage of the circulation line due to a narrow path will occur. In addition, in order to meet the environmental regulations of copiers and printers that will be further accelerated in the future, increase the functionality, and increase the functionality of VOC (organic volatile components), the thermal history given to the toner will be reduced and the organic volatile components will be sufficient. Need to be removed. The above method is not sufficient to meet this requirement. Furthermore, it is necessary to increase the removal efficiency of volatile components.

  Further, a method for removing organic volatile components while suppressing foaming by placing the evaporator in a reduced pressure state and injecting air or an inert gas from the lower part of the toner dispersion in the presence of an antifoaming agent has been proposed ( (See Patent Document 4). However, when an antifoaming agent is used, it is difficult to completely remove the antifoaming agent from the toner particles, which has a problem that it adversely affects the toner performance.

JP 59-61842 A Japanese Patent No. 3950743 JP 2002-108014 A JP 2007-232775 A

  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 production method in which the organic volatile components can be sufficiently reduced while removing the organic volatile components in a short time in order to reduce damage to the toner in the production method of the toner by the polymerization method. It is.

  Another object of the present invention is to provide a method for producing a toner having better image characteristics more efficiently and stably than before.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a toner that can remove organic volatile components more efficiently than the conventional one and has superior image characteristics can be obtained by the following method. The manufacturing method which can be provided was discovered.

That is, the present invention has the following features:
In the method for producing toner particles, the method comprises heating a toner particle dispersion containing toner particles produced in an aqueous medium and removing at least organic volatile components present in the toner particle dispersion .
The devolatilization step, using a devolatilization device having an external circulation path and evaporation container, the toner particle dispersion liquid to return to the evaporation vessel via the evaporation vessel do we said external fan 循 is ring, this time, the 100 ° C. or more saturated steam was charged into the external circulation path is the step of heating the toner particle dispersion liquid by contacting said toner particle dispersion liquid and the saturated steam directly This is a method for producing toner particles.

  According to the present invention, in the volatile component removal step, an evaporation container having an external circulation path is used, and saturated water vapor of 100 ° C. or higher is directly introduced into the circulation path, thereby promoting foaming more than before. A large amount of saturated water vapor can be brought into contact with the toner particle dispersion.

  As a result, the organic volatile component removal efficiency can be increased more than ever.

  Further, by introducing saturated steam directly into the circulation path, it is not necessary to go through a narrow path such as an external heat exchanger. As a result, stable operation can be performed without blocking the inside of the piping.

  A volatile component removal apparatus in the volatile component removal step preferably used in the present invention is shown in FIGS. 3 and 4 show a system according to the present invention. FIG. 5 shows a conventional volatile component removal apparatus using a heat exchanger in the external circulation path. FIG. 6 shows a schematic diagram of a rotating disk. However, the volatile component removal apparatus used in the present invention is not limited to these.

  Hereinafter, preferred embodiments of the method for producing toner particles of the present invention will be described with reference to the drawings.

  In FIG. 3, the polymerizable monomer composition prepared in the dissolving container 1 for performing the dissolving step is dispersed in the aqueous medium in the granulating vessel 10 for performing the granulating step. Dispersion and granulation are carried out for a certain period of time by a strong shearing force, impact and turbulence generated between a high-speed rotating stirring blade incorporated in a stirring device 11 installed in the granulating vessel 10 and the screen. To form micron-order polymerizable monomer composition particles. The particles of the formed polymerizable monomer composition are sent to the polymerization container 12 through the liquid inlet 7 together with the aqueous medium. The particles of the polymerizable monomer composition and the aqueous medium in the polymerization vessel 12 are stirred by the temperature control by the jacket 4 and the stirring blade 5 driven by the stirring drive device 2 and maintained at a desired temperature for a certain time. As a result, the polymerizable monomer in the particles of the polymerizable monomer composition is polymerized to form toner particles. After the polymerization is completed, a dispersion containing toner particles (hereinafter, toner particle dispersion) is sent to the evaporation container 3.

  In the subsequent volatile component removal step, as shown in FIG. 1, the toner particle dispersion is stirred using a stirring blade 6 installed at the lower part of the evaporation container 3. Then, the toner particle dispersion is extracted from below the evaporation container 3 and is ejected from the upper part of the evaporation container 3 toward the gas phase portion while being fed using the circulation pump 8. By this ejection, it is possible to suppress foaming.

  At this time, the heating of the toner particle dispersion is achieved by directly introducing saturated water vapor into the external circulation path 9. In this way, direct heating, which is directly charged, can be efficiently performed by bringing saturated water vapor directly into contact with the toner particle dispersion compared to indirect heating such as a heat exchanger. Moreover, it is possible to generate a violent turbulent flow in the circulation pipe, and it is possible to reduce adhesion and fusion in the pipe.

  Next, the heated toner particle dispersion is finely dispersed by being flushed in the gas phase portion, and evaporation is promoted by increasing the volatile surface in contact with the gas phase portion.

  At this time, heating from the jacket 4 may be performed, but it is preferable not to perform heating in order to suppress deposits on the wall surface of the evaporation container 3.

  The temperature of the fluid in a state where the toner particle dispersion and the water vapor are mixed after the saturated water vapor is introduced in the external circulation path 9 is measured by the liquid + vapor thermometer 13.

  Further, as shown in FIG. 1, it is also possible to introduce saturated steam into the toner particle dispersion from the container lower saturated steam charging line 14. By introducing saturated water vapor into both the external circulation path 9 and the toner particle dispersion in the evaporation container 3, the removal efficiency of volatile components can be further increased.

  However, if a large amount of saturated water vapor is added to the toner particle dispersion, foaming is promoted depending on the treatment liquid. Therefore, it is preferable that the introduction of the saturated water vapor into the toner particle dispersion is appropriately selected depending on the treatment liquid. .

  Even in the case of charging, it is preferable that the amount is smaller than the amount of saturated water vapor flowing into the external circulation path 9. Further, according to the present invention, as shown in FIG. 2, a rotatable rotating disk 16 connected to a motor is provided in the vapor phase portion of the evaporation container 3, and toner particles are directed from the upper part of the evaporation container 3 toward the rotating disk 16. The dispersion liquid may be ejected. The toner particle dispersion ejected on the rotating disk 16 is scattered toward the inner wall surface of the evaporation container 3 by the rotation of the rotating disk 16 and flows down while forming a thin film on the inner wall surface of the evaporation container 3.

  By scattering from the turntable 16 toward the wall surface, the volatile surface increases and evaporation can be further promoted. Further, the toner particle dispersion liquid scattered with the rotating disk 16 forms a thin film and obtains a shower effect on the liquid surface. Since this shower effect also works to break bubbles on the liquid surface, it is possible to physically suppress the bubbles so that the bubble layer does not grow above the turntable 16.

  Also in the volatile component removal apparatus shown in FIG. 2, saturated water vapor may be allowed to flow into the toner particle dispersion according to the foamability of the treatment liquid.

  Although common to FIGS. 1 and 2, the evaporated components including water vapor and organic volatile component vapor pass through the exhaust line 17, are condensed by the condenser 18, and are collected in the fraction tank 19. Components that could not be condensed are discharged out of the system.

  In the present invention, as shown in FIG. 4, after completing the polymerization in the polymerization vessel 12, the processing liquid is externally circulated using the same tank, and saturated steam is introduced into the external circulation path 9. The processing liquid may be ejected from the upper part of the container to perform the evaporation operation.

  Moreover, as the stirring blade used in the evaporation container 3, an apparatus that can uniformly stir the entire container is preferable. For example, paddle wing, three-bladed wing, anchor wing, more preferably full zone wing (manufactured by Shinko Pantech Co., Ltd.), max blend wing (manufactured by Sumitomo Heavy Industries, Ltd.), sun meller wing (manufactured by Mitsubishi Heavy Industries, Ltd.), Hi-F Examples include a mixer blade (manufactured by Soken Chemical Co., Ltd.), a bend leaf blade (manufactured by Hachiko Sangyo Co., Ltd.), and a resolver blade (manufactured by Mtechnic Co., Ltd.).

  When a stirring motor is provided on the evaporation container 3 and a stirring blade connected via a shaft is provided at the lower part of the evaporation container, the toner particles in the toner particle dispersion ejected from the upper part of the container are fused to the shaft. And the maintainability is deteriorated. Furthermore, there is a concern that the fused material that has grown grows in the processing liquid and induces production troubles such as clogging in the subsequent production process.

  In order to prevent this, it is preferable that a stirring motor 15 is provided under the evaporation container 3 and a stirring blade 6 connected to the stirring motor 15 is provided below the evaporation container. The stirring blade 6 shown in FIGS. 1 and 2 is an example.

  In the present invention, the temperature of the saturated water vapor introduced into the external circulation path is preferably 100 ° C. or higher. When the temperature of the saturated water vapor is lower than 100 ° C., the temperature of the aqueous medium in the evaporation vessel 3 does not reach the boiling point at normal pressure, and the vapor of the organic volatile component including the vapor of the polymerizable monomer is used as the evaporation vessel 3 system. It is not preferable because the speed of removal to the outside decreases.

  In the present invention, the surface of the toner particles is coated with a particulate / slightly soluble inorganic dispersant or surfactant. If the toner particles are uniformly dispersed in the aqueous medium, high-temperature and high-pressure saturated water vapor of 100 ° C. or higher is introduced into the circulation path, so that the toner particle dispersion can be obtained even when the temperature of the toner particle dispersion becomes 100 ° C. There is no negative impact on quality. Organic volatile components can be efficiently removed from the toner particles without causing aggregation of the toner particles. Further, even if the toner particle dispersion is exposed to 100 ° C. or more by the introduction of saturated water vapor in the external circulation path 9, from the viewpoint that the residence time in the external circulation path 9 is very short, the toner quality can be improved. There are few adverse effects.

  It is also possible to provide a plurality of saturated steam inlets into the external circulation path 9. By dividing the inlet of saturated water vapor, the toner particle dispersion can be heated more uniformly.

  Further, in the present invention, the temperature of the saturated water vapor introduced into the external circulation path 9 is preferably 105 ° C. to 180 ° C., and the vapor pressure P1 (kPa) is preferably 122 ≦ P1 ≦ 1015. .

  If it is less than 122 kPa, the heating efficiency is low and it takes time to distill off the organic volatile components, which is not preferable. On the other hand, if it exceeds 1015 kPa, saturated steam cannot be obtained with a normal steam generator, which is a factor of high cost.

  When the saturated water vapor is lower than 105 ° C., not only the heating efficiency is low, but also the temperature drop due to heat dissipation occurs when the toner particle dispersion is ejected to the gas phase portion via the external circulation path 9. As a result, condensation occurs and the amount of liquid in the evaporation container 3 increases, which is not preferable.

  When the saturated water vapor is higher than 180 ° C., the pressure is increased and the toner particle dispersion is vigorously mixed. At that time, the chance of contact between the toner particles and the saturated water vapor increases, which may cause thermal damage to the toner particles.

  The temperature of the saturated water vapor and the vapor pressure P1 are measured by the vapor thermometer 1 and the vapor pressure gauge 1 shown in FIGS.

In the present invention, when the pressure of the toner particle dispersion in the external circulation path 9 is P2 (kPa), it is preferable that P1> P2. Within this range, saturated water vapor flows smoothly into the external circulation path 9. In the case of P1 ≦ P2, not only does the saturated steam flow smoothly into the external circulation path 9,
Since the toner particle dispersion in the circulation path flows back into the saturated water vapor line, it is not preferable.

  Further, the larger the pressure difference between P1 and P2, the more uniformly the toner particle dispersion and the saturated water vapor are mixed, and the heating efficiency is improved. The pressure difference between P1 and P2 is preferably maintained at 30 kPa or more. The pressure P2 of the toner particle dispersion liquid in the external circulation path is measured by the liquid pressure gauge 21.

  Further, a static mixer (manufactured by Noritake Co., Ltd.) can be introduced into the piping upstream of the saturated steam inlet in order to mix the saturated steam and the toner particle dispersion in the circulation path homogeneously. Thereby, it is possible to further increase the heating efficiency of the toner particle dispersion.

  In the present invention, when returning the toner particle dispersion into the evaporation container 3 via the external circulation path 9, it is preferable to eject the toner particle dispersion into the gas phase portion in the evaporation container.

  Since the liquid pressure in the circulation path into which the saturated water vapor has been introduced becomes higher than the pressure in the vapor phase in the evaporation container, the liquid is ejected from the circulation line in the state dispersed in the gas phase by flushing at the outlet in the evaporation container. As a result, the area where the toner particle dispersion comes into contact with the gas phase portion is increased, and evaporation is promoted.

  If the toner particle dispersion is returned to the liquid via the external circulation path 3, when the saturated water vapor passes through without condensing from the liquid phase to the gas phase, foaming is promoted, and the saturated water vapor flows in. This is not preferable because the amount is limited.

  The method for jetting into the gas phase portion is not particularly limited, but in addition to the method using the rotating disk 16 described above, evaporation is performed using a nozzle having a plurality of holes of about 0.5 to 30 mm. An example of the ejection method is ejection toward the toner particle dispersion in the container. This method can improve the evaporation performance and suppress bubbles. However, depending on the treatment liquid, the nozzle may be clogged due to mixing of coarse particles, and therefore the use of the nozzle is appropriately selected depending on the treatment liquid.

  In the present invention, as described above, it is also possible to introduce saturated water vapor into the toner particle dispersion from the container lower part saturated water vapor introduction line 14 below the evaporation container 3. When saturated water vapor is added to the toner particle dispersion, the temperature of the saturated water vapor is preferably 105 ° C. to 180 ° C., and the vapor pressure P3 (kPa) of the saturated water vapor is preferably 122 ≦ P3 ≦ 1015.

  When P3 is less than 122 kPa, there is a high possibility that saturated water vapor is condensed in the toner particle dispersion liquid, and the liquid level rises, which is not preferable. On the other hand, if it exceeds 1015 kPa, saturated steam cannot be obtained with a normal steam generator, which is a factor of high cost.

  Moreover, when saturated water vapor is smaller than 105 degreeC, since heating efficiency will become low, it is unpreferable.

  When the saturated water vapor is higher than 180 ° C., the pressure is increased and the toner particle dispersion is vigorously mixed. At that time, the chance of contact between the toner particles and the saturated water vapor increases, which may cause thermal damage to the toner particles.

  The temperature and vapor pressure P3 of saturated water vapor are measured by the vapor thermometer 2 and the vapor pressure gauge 2 shown in FIGS.

  In the present invention, the temperature of the toner particle dispersion in the evaporation container is preferably 95 to 105 ° C. The above temperature indicates the temperature when the temperature rise is completed and the liquid temperature is stabilized.

  When the liquid temperature in the evaporation container 3 is lower than 95 ° C., the evaporation efficiency is remarkably lowered, which is not preferable. On the other hand, when the liquid temperature is higher than 105 ° C., thermal damage to the toner particles increases, which is not preferable. The liquid temperature in the evaporation container 3 is measured by an evaporation container liquid temperature meter 20 shown in FIGS.

  Examples of the stirrer 11 installed in the granulating container 10 in the present invention include, for example, Ultra Thalax (manufactured by IKA), Polytron (manufactured by Kinematica), TK auto homomixer (manufactured by Tokushu Kika Kogyo), Batch mixers such as cooking mixers (Matsushita Electric Industrial Co., Ltd.); Ebara Milder (Ebara Seisakusho Co., Ltd.), TK Pipeline Homomixer, TK Homomic Line Flow (Made by Special Machinery Corporation), Colloid Mill (Japan) Seiki Co., Ltd.), Thrasher, Trigonal Wet and Fine Crusher (Mitsui Miike Chemical Co., Ltd.), Cavitron (Eurotech Co., Ltd.), Fine Flow Mill (Pacific Kiko Co., Ltd.); ), Batch or continuous dual-use stirrers such as Fillmix (manufactured by Koki Kogyo Co., Ltd.); Microfluidizer (Mizuho Kogyo Co., Ltd.), Nano manufacturer, Nanomizer (Nanomizer, Inc.), APV Gaulin (Gaulin) such as high-pressure emulsifier of; such as an ultrasonic homogenizer (manufactured by Branson) ultrasonic emulsifier and the like.

  The particle size of the toner particles obtained is usually controlled by the amount of the dispersion stabilizer used and the number of rotations of the stirring blade. The peripheral speed of the stirring blade is preferably controlled at a peripheral speed of 15 to 40 m / sec at the tip of the stirring blade from the viewpoint of sharpening the particle size distribution of the obtained particles. If the peripheral speed is less than 15 m / sec, it is difficult to reduce the droplet particle size in a short time. If the peripheral speed is 40 m / sec or more, it is very fine and inappropriate for use as toner particles. Many particles are generated and the particle size distribution tends to be wide. More preferably, the tip peripheral speed of the stirring blade is controlled to a peripheral speed of 20 to 35 m / sec.

  According to the method for producing toner particles of the present invention, toner particles having a total amount of organic volatile components at 150 ° C. of 300 ppm or less, preferably 200 ppm or less, more preferably 100 ppm or less can be efficiently produced. A toner obtained by externally adding an external additive to toner particles having an organic volatile component content of 150 ppm or less at 150 ° C. has a total organic volatile component content of 300 ppm or less at 150 ° C. A toner obtained by externally adding an external additive to toner particles having a total amount of organic volatile components at 200 ° C. of 200 ppm or less has a total amount of organic volatile components at 120 ° C. of 200 ppm or less and a total amount of organic volatile components at 150 ° C. of 100 ppm or less. The toner obtained by externally adding an external additive to the toner particles has a total amount of organic volatile components at 150 ° C. of 100 ppm or less.

  Furthermore, according to the method for producing toner particles of the present invention, the binder resin is a styrene polymer, a polymer of a styrene derivative, a styrene-acrylate copolymer, a styrene-methacrylate ester, a styrene-acrylate ester- When a vinyl resin selected from the group consisting of a methacrylic acid ester copolymer and a mixture thereof is contained as a main component, toner particles in which the residual amount of vinyl monomer is 75 ppm or less, preferably 50 ppm or less are efficiently obtained. Can be manufactured. From these toner particles, it is possible to provide a toner in which the residual amount of vinyl monomer is 75 ppm or less, more preferably 50 ppm or less.

  Furthermore, according to the present invention, it is preferable that the average circularity of the toner particles after the volatile component removing step is in the range of 0.955 to 0.995.

  The circularity in the present invention indicates an average circularity of a group of particles having a circle-equivalent diameter of 0.60 μm or more in a number-based particle diameter measured by a toner flow type particle image analyzer.

  When the average circularity is less than 0.955, the edge portion of the toner surface increases, the charge is localized in one particle, and the charge amount distribution tends to be broad. Therefore, it is not preferable because the latent image is not developed faithfully. When the average circularity is greater than 0.995, there is a concern about poor cleaning, which is not preferable.

  When the liquid temperature of the toner particle dispersion in the external circulation path 9 and the evaporation container 3 is excessively increased, the toner particle surface becomes too smooth and the average circularity may exceed 0.995. Alternatively, toner particles in the aqueous medium may aggregate and the average circularity may be less than 0.955. Therefore, it is necessary to adjust the temperature and pressure of the saturated water vapor introduced into the external circulation path 9 and the evaporation container 3 so that the temperature of the toner particle dispersion does not excessively increase.

  Further, assuming that the average circularity of the toner particles before the volatile component removing step is A and the average circularity of the toner particles after the volatile component removing step is B, −0.025 ≦ A−B ≦ 0.025. It is preferable to control the operating conditions of the volatile component removal step. When the aggregation of toner particles in the aqueous medium is remarkably −0.025> A-B, or when the surface is remarkably smooth and A−B> 0.025, both are thermally applied to the toner. Undesirably large damage will adversely affect quality.

  The method for producing toner particles of the present invention can also be preferably used for a method for producing magnetic toner particles. For example, a magnetic material used in the production of magnetic toner particles in the case of wet granulation by suspension polymerization will be described below.

  The surface of the magnetic material used in the magnetic toner is preferably hydrophobized. When hydrophobizing the magnetic material, it is very preferable to use a method in which the surface treatment is carried out while hydrolyzing the coupling agent while dispersing the magnetic material particles so as to have a primary particle size in an aqueous medium. In this hydrophobization method, the magnetic particles are less likely to coalesce than in the gas phase, and the magnetic repulsion action between the magnetic particles due to the hydrophobization treatment works, so the magnetic material is almost in the state of primary particles. Surface treatment with.

  The method of treating the surface of the magnetic material while hydrolyzing the coupling agent in an aqueous medium does not require the use of a coupling agent that generates gas, such as chlorosilanes and silazanes. In addition, since the magnetic particles can be easily united in the gas phase so far, it is possible to use a highly viscous coupling agent that has been difficult to perform well, so the effect of hydrophobization is tremendous. It is.

Examples of the coupling agent that can be used in the surface treatment of the magnetic material according to the present invention include a silane coupling agent and a titanium coupling agent. More preferably used is a silane coupling agent, which has the following general formula R _m SiY _n
[In the formula, R represents an alkoxy group, m represents an integer of 1 to 3, Y represents a hydrocarbon group such as an alkyl group, a vinyl group, a glycidoxy group, or a methacryl group, and n represents an integer of 1 to 3. Show]
It is shown by.

  For example, the following are mentioned. Vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyl Diethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxy Silane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, n-butyltrimethoxysilane, isobutyl Trimethoxysilane, trimethyl methoxysilane, hydroxypropyl trimethoxysilane, n- hexadecyl trimethoxysilane, n- octadecyl trimethoxysilane.

  Among these, in order to further improve the dispersibility of the magnetic substance, it is preferable to use a silane coupling agent having a double bond. More preferred are phenyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-glycidoxypropyltrimethoxysilane. This is considered to be because, particularly when suspension polymerization is performed, the compatibility between the magnetic substance and the polymerizable monomer is improved by treatment with a coupling agent having a double bond. The dispersibility of the magnetic substance in the toner particles is good.

However, it is difficult to give the magnetic material sufficient hydrophobicity by using only the coupling agent having these double bonds, and due to the influence of the magnetic material having insufficient hydrophobicity being exposed on the toner surface, The particle size distribution of the toner is also wide. The reason for this is not clear, but is thought to be due to inferior hydrophobicity of the coupling agent itself, reactivity with active groups on the surface of the magnetic material, and poor coverage with the surface of the magnetic material. For this reason, in order to obtain sufficient hydrophobicity, it is more preferable to use together an alkyltrialkoxysilane coupling agent represented by the following formula.
_{C p H 2p + 1 -Si- (} OC q H 2q + 1) 3
[Wherein, p represents an integer of 2 to 20, and q represents an integer of 1 to 3]

  In the above formula, when p is smaller than 2, the hydrophobizing treatment is easy, but it is difficult to sufficiently impart hydrophobicity, and it becomes difficult to suppress the exposure of the magnetic particles from the toner particles. On the other hand, when p is larger than 20, the hydrophobicity is sufficient, but the coalescence between the magnetic particles increases, making it difficult to sufficiently disperse the magnetic particles, and the particle size distribution becomes broad. On the other hand, when q is larger than 3, the reactivity of the silane coupling agent is lowered and the hydrophobicity is not sufficiently performed.

  More preferably, an alkyltrialkoxysilane coupling agent in which p is an integer of 3 to 15 and q is 1 or 2 in the above formula is used.

  The treatment amount is 0.05 to 20 parts by mass, preferably 0.1 to 10 parts by mass of the silane coupling agent with respect to 100 parts by mass of the magnetic substance, and the surface area of the magnetic substance and the reaction of the coupling agent It is preferable to adjust the amount of the treatment agent according to the property.

  Moreover, the aqueous medium used at the time of the hydrophobic treatment is a medium containing water as a main component. Specific examples of the aqueous medium include water itself, water added with a small amount of a surfactant, water added with a pH adjusting agent, and water added with an organic solvent. As the surfactant, a nonionic surfactant such as polyvinyl alcohol is preferable. The surfactant is preferably added in an amount of 0.1 to 5% by mass with respect to water. Examples of the pH adjuster include inorganic acids such as hydrochloric acid, and examples of the organic solvent include alcohols.

  In the case where a plurality of types of silane coupling agents are used, a plurality of types of coupling agents are added simultaneously or with a time difference, and the magnetic material is processed.

  In the magnetic material thus obtained, no particle aggregation is observed, and the surface of each particle is uniformly hydrophobized, so that the dispersibility of the magnetic material in the polymerizable monomer is good.

The magnetic material used in the toner of the present invention may contain elements such as phosphorus, cobalt, nickel, copper, magnesium, manganese, aluminum, and silicon. Further, the magnetic substance is mainly composed of iron oxide such as triiron tetroxide and γ-iron oxide, and these are used alone or in combination of two or more. These magnetic materials preferably have a BET specific surface area by nitrogen adsorption method of 2 to 30 m ² / g, more preferably 3 to 28 m ² / g, and a Mohs hardness of 5 to 7.

  For example, in the case of a wet granulation method using a suspension polymerization method, it is preferable to use 10 to 200 parts by mass of the magnetic substance with respect to 100 parts by mass of the polymerizable monomer or the binder resin. More preferably, 20 to 180 parts by mass are used. If it is less than 10 parts by mass, the coloring power of the toner is poor, and it is difficult to suppress fogging. On the other hand, when the amount exceeds 200 parts by mass, not only the retention force of the obtained toner due to the magnetic force on the toner carrier increases, but the developability decreases, and it is difficult not only to uniformly disperse the magnetic material to individual toner particles. , The fixing property is lowered.

  The content of the magnetic substance in the toner is measured with a thermal analyzer, TGA7, manufactured by PerkinElmer. In the measurement method, the toner is heated from normal temperature to 900 ° C. at a temperature increase rate of 25 ° C./min in a nitrogen atmosphere, and the weight loss from 100 ° C. to 750 ° C. is defined as the binder resin amount, and the residual mass is approximately calculated. The amount of magnetic material.

  For example, in the case of magnetite, the magnetic material used in the magnetic toner according to the present invention is manufactured by the following method. An aqueous solution containing ferrous hydroxide is prepared by adding an alkali such as sodium hydroxide in an amount equivalent to or higher than the iron component to the ferrous salt aqueous solution. Air was blown in while maintaining the pH of the prepared aqueous solution at 7 or more (preferably pH 8 to 14), and iron oxide was oxidized while heating the aqueous solution to 70 ° C. First, a seed crystal is formed.

  Next, an aqueous solution containing about 1 equivalent of ferrous sulfate is added to the slurry-like liquid containing seed crystals based on the amount of alkali added previously. While maintaining the pH of the solution at 6 to 14, the reaction of ferrous hydroxide proceeds while blowing air to grow magnetic iron oxide particles with the seed crystal as the core. As the oxidation reaction proceeds, the pH of the liquid shifts to the acidic side, but the pH of the liquid is preferably not less than 6. Adjust the pH of the solution at the end of the oxidation reaction, stir well so that the magnetic iron oxide becomes primary particles, add the coupling agent, stir well, stir, filter, dry, and lightly crush after stirring By doing so, hydrophobic treated magnetic iron oxide particles can be obtained. Alternatively, after the oxidation reaction is completed, the iron oxide particles obtained by washing and filtering are redispersed in another aqueous medium without drying, and then the pH of the redispersion is adjusted and the silane is stirred well. A coupling agent may be added to perform the coupling treatment. In any case, it is important to perform the surface treatment after the oxidation reaction without passing through the drying step.

  As the ferrous salt, iron sulfate generally produced as a by-product in the production of sulfuric acid titanium, iron sulfate produced as a by-product with the surface cleaning of the steel sheet can be used, and iron chloride or the like can be used.

  In the method of producing magnetic iron oxide by the aqueous solution method, when iron sulfate is used, in general, the aqueous solution having an iron concentration of 0.5 to 2 mol / l is used from the viewpoint of preventing viscosity increase during the reaction and the solubility of iron sulfate. It is done. Generally, the lower the iron sulfate concentration, the finer the particle size of the product. Further, in the reaction, the more the amount of air is and the lower the reaction temperature is, the easier it is to atomize.

  By using the magnetic toner made of the hydrophobic magnetic particles produced as described above, stable toner charging property can be obtained, transfer efficiency is high, and high image quality and high stability are possible.

  The magnetic material obtained as described above can be suitably used as a colorant contained in the toner particles. However, the magnetic material other than the magnetic material that can be suitably used for the toner produced in the present invention. Examples of the agent include carbon black and the following yellow / magenta / cyan colorants.

  As a colorant suitable for the yellow color, a pigment or a dye can be used. Specific examples of yellow pigments include the following. C. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 17, 23, 62, 65, 73, 74, 81, 83, 93, 94, 95, 97, 98, 109, 110, 111, 117, 120, 127, 128, 129, 137, 138, 139, 147, 151, 154, 155, 167, 168, 173, 174, 176, 180, 181, 183, 191 and C.I. I. Bat yellow 1, 3, 20 The following are mentioned as a yellow dye. C. I. Solvent yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162. These may be used alone or in combination of two or more.

  As a colorant suitable for magenta, a pigment or a dye can be used. Specific examples of the magenta pigment include the following. C. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 48; 2, 48; 3, 48; 4, 49, 50, 51, 52, 53, 54, 55, 57, 57; 1, 58, 60, 63, 64, 68, 81, 81; 1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 144, 146, 150, 163, 166, 169, 177, 184, 185, 202, 206, 207, 209, 220, 221, 238, 254; I. Pigment violet 19; C.I. I. Vat Red 1, 2, 10, 13, 15, 23, 29, 35. Examples of the magenta dye include the following. C. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 52, 58, 63, 81, 82, 83, 84, 100, 109, 111, 121, 122; I. Disper thread 9, C.I. I. Solvent Violet 8, 13, 14, 21, 27; C.I. I. Oil-soluble dyes such as Disperse Violet 1; I. B. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40; I. Basic dyes such as basic violet 1,3,7,10,14,15,21,25,26,27,28. These may be used alone or in combination of two or more.

  As a colorant suitable for cyan, a pigment or a dye can be used. Specifically, the following are mentioned as a cyan pigment. C. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 16, 17, 60, 62, 66; I. Bat Blue 6, C.I. I. Acid Blue 45. Examples of the cyan dye include the following. C. I. Solvent Blue 25, 36, 60, 70, 93, 95. These may be used alone or in combination of two or more.

  The colorants can be used alone or in admixture of two or more, and further can be used 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. For example, in the case of the wet granulation method by the suspension polymerization method, the colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer or resin.

  The toner particles produced in the present invention may contain a release agent. Examples of the release agent include the following. Petroleum wax such as paraffin wax, microcrystalline wax, petrolatum and derivatives thereof; montan wax and derivatives thereof; hydrocarbon wax and derivatives thereof according to the Fischer-Tropsch method; polyolefin wax and derivatives thereof such as polyethylene wax and polypropylene wax; carnauba wax; Natural waxes such as candelilla wax and derivatives thereof. Derivatives include oxides, block copolymers with vinyl monomers, and graft modified products. Further, higher fatty alcohols, fatty acids such as stearic acid and palmitic acid, or compounds thereof, acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, plant waxes, and animal waxes.

  Specific examples of the wax that can be used as a release agent include Biscol (registered trademark) 330-P, 550-P, 660-P, TS-200 (Sanyo Chemical Industries); High wax 400P, 200P, 100P, 410P, 420P, 320P, 220P, 210P, 110P (Mitsui Chemicals); Sazol H1, H2, C80, C105, C77 (Schumann Sazol); HNP-1, HNP-3, HNP-9, HNP-10, HNP- 11, HNP-12 (Nippon Seiki Co., Ltd.); Unilin (registered trademark) 350, 425, 550, 700, Unicid (registered trademark), Unicid (registered trademark) 350, 425, 550, 700 (Toyo Petrolite Co., Ltd.) Wax, beeswax, rice wax, candelilla wax, carnauba wax (Serarica N Co., Ltd.) Available at the DA).

  A charge control agent may be blended in the toner particles. A well-known thing can be utilized as a charge control agent. Further, for example, in the case of a wet granulation method using a suspension polymerization method, when producing toner particles, a charge control agent having a low polymerization inhibitory property and substantially free from a solubilized product in an aqueous dispersion medium is particularly preferable. Examples of the negative charge control agent include the following. Metallic compounds of aromatic carboxylic acids such as salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid; metal salts or metal complexes of azo dyes or azo pigments; polymer type having sulfonic acid or carboxylic acid group in the side chain Compound: Boron compound, urea compound, silicon compound, calixarene. Examples of the positive charge control agent include the following. A quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, a nigrosine compound, and an imidazole compound.

  As a method of adding a charge control agent to the toner, there are a method of adding it inside the toner particles and a method of adding it externally to the toner particles. The amount of these charge control agents to be used is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and a dispersion method, and is not uniquely limited. In the case of internal addition, it is preferably used in the range of 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the polymerizable monomer or binder resin. In the case of external addition, the amount is preferably 0.005 to 1.0 part by mass, more preferably 0.01 to 0.3 part by mass with respect to 100 parts by mass of the toner particles.

  In the present invention, in the case of wet granulation by emulsion polymerization or suspension polymerization, examples of the polymerizable monomer include the following.

  Styrene; Styrenic monomers such as o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-ethylstyrene; methyl acrylate, ethyl acrylate, n-butyl acrylate, acrylic acid Acrylic esters such as isobutyl, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; methyl methacrylate, methacrylic acid Ethyl, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethyl methacrylate Aminoethyl, such as methacrylic acid esters of diethylaminoethyl methacrylate; acrylonitrile, methacrylonitrile, acrylamide.

  In the toner production method of the present invention, in the case of the wet granulation method by the suspension polymerization method, the polymerization may be performed by adding a resin to the polymerizable monomer. Hydrophilic functional groups such as amino groups, carboxylic acid groups, hydroxyl groups, sulfonic acid groups, glycidyl groups, and nitrile groups that cannot be used because polymerizable monomers dissolve in water and cause emulsion polymerization due to water solubility. As a copolymer such as a random copolymer of these and a vinyl compound such as styrene or ethylene, a block copolymer, or a graft copolymer Alternatively, it is preferably added as a polycondensate such as polyester or polyamide, or as a polyaddition polymer such as polyether or polyimine.

  In the present invention, an alcohol component and an acid component constituting the polyester resin used by adding to the polymerizable monomer are exemplified below. The following are mentioned as an alcohol component. Ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol 2-ethyl-1,3-hexanediol, cyclohexanedimethanol, butenediol, octenediol, cyclohexenedimethanol, hydrogenated bisphenol A, a bisphenol derivative represented by the formula (I) or the formula (I) Hydrogenated compounds;

［式中、Ｒはエチレン基またはプロピレン基を示し、ｘ及びｙはそれぞれ１以上の整数であり、かつｘ＋ｙの平均値は２乃至１０である。］

[Wherein, R represents an ethylene group or a propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 10. ]

  Or a hydrogenated product of a diol represented by the following formula (II) or a compound represented by the formula (II).

  Examples of the divalent carboxylic acid include the following. Benzene dicarboxylic acid or its anhydride such as phthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride; alkyl dicarboxylic acid or its anhydride such as succinic acid, adipic acid, sebacic acid, azelaic acid, or further 6 to 18 carbon atoms A succinic acid substituted with an alkyl or alkenyl group or an anhydride thereof; an unsaturated dicarboxylic acid such as fumaric acid, maleic acid, citraconic acid, itaconic acid, or an anhydride thereof.

  Furthermore, the following are mentioned as an alcohol component. Polyhydric alcohols such as oxyalkylene ethers of glycerin, pentaerythritol, sorbit, sorbitan, and novolac phenolic resins. Examples of the acid component include the following. Multivalent carboxylic acids such as trimellitic acid, pyromellitic acid, 1,2,3,4-butanetetracarboxylic acid, benzophenonetetracarboxylic acid and its anhydride.

  It is preferable that 45 to 55 mol% of the polyester resin is an alcohol component and 55 to 45 mol% is an acid component in all components. In the present invention, as long as the physical properties of the obtained toner particles are not adversely affected, it is also preferable to use two or more polyester resins together or to modify the physical properties by modifying with silicone or a fluoroalkyl group-containing compound. To be done. Moreover, when using the high molecular polymer containing such a polar functional group, the weight average molecular weight is preferably 5,000 or more.

  Moreover, you may add resin other than the above in a monomer composition. The following are mentioned as resin. Polystyrene; homopolymer of styrene-substituted product such as polyvinyltoluene; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-acrylic acid Ethyl copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate Copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer Coalescence, styrene-butadi Copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene copolymer such as styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, Polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin. These can be used alone or in combination.

  The addition amount of these resins is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. If the amount is less than 1 part by mass, the effect of addition is small, while if it exceeds 20 parts by mass, it becomes difficult to design various physical properties of the polymerized toner.

  Further, a polymer having a molecular weight different from the molecular weight range of the toner obtained by polymerizing the polymerizable monomer may be dissolved in the polymerizable monomer for polymerization.

  In the method for producing a toner of the present invention, when a polymerization initiator is used for initiating a polymerization reaction of a polymerizable monomer, a monomer having a half-life of 0.5 to 30 hours during the polymerization reaction is used. It is preferable to carry out the polymerization reaction at an addition amount of 0.5 to 20 parts by mass with respect to 100 parts by mass of the monomer. As a result, a polymer having a maximum between 10,000 and 100,000 can be obtained, and the toner can be provided with desirable strength and appropriate melting characteristics. Examples of the polymerization initiator include the following. 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis Azo or diazo polymerization initiators such as -4-methoxy-2,4-dimethylvaleronitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2, Peroxide polymerization initiators such as 4-dichlorobenzoyl peroxide, lauroyl peroxide, t-butylperoxy 2-ethylhexanoate, and t-butylperoxypivalate.

  When the toner of the present invention is produced, a crosslinking agent may be added, and a preferable addition amount is 0.001 to 15 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  Examples of the crosslinking agent mainly include compounds having two or more polymerizable double bonds. For example, the following are mentioned. Aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylate esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate and 1,3-butanediol dimethacrylate; divinylaniline, divinyl ether and divinyl Divinyl compounds such as sulfide and divinyl sulfone; and compounds having three or more vinyl groups. These are used alone or as a mixture of two or more.

  An example of a method for producing the toner of the present invention is a method in which resin particles are prepared by fusing in an aqueous medium. The method is not particularly limited, and examples thereof include methods disclosed in JP-A-5-265252, JP-A-6-329947, and JP-A-9-15904. That is, a method of associating a plurality of fine particles composed of resin particles and colorants or the like, or a resin, a colorant and the like, particularly after dispersing them in an aqueous medium using an emulsifier, By adding a flocculant of a coagulation concentration or higher and salting out, at the same time, heat fusion at a temperature higher than the glass transition temperature of the formed polymer itself, and heating and drying the particles in a fluid state in a water-containing state, the present invention. The toner can be formed. 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.

  In the present invention, for example, a specific toner production method when a wet granulation method by a suspension polymerization method is selected will be described.

  First, components necessary as a toner, such as pigments, mold release agents, plasticizers, charge control agents, cross-linking agents, and other additives in the polymerizable monomer (for example, to reduce the viscosity of the polymer produced by the polymerization reaction) An organic solvent, a high molecular weight polymer, and a dispersing agent) are appropriately added and uniformly dissolved or dispersed to obtain a colorant-containing polymerizable monomer composition. At this time, you may perform temperature control operation as needed. This polymerizable monomer composition is suspended and granulated in an aqueous medium containing a dispersion stabilizer.

  At this time, the polymerizable monomer composition is granulated, or after granulation, the polymerization initiator is added to polymerize the composition (polymerization step). The specific timing of addition of the polymerization initiator may be added simultaneously with the addition of other additives in the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. Moreover, a polymerization initiator dissolved in an additional polymerizable monomer or solvent during the polymerization reaction can be added immediately after granulation and before starting the polymerization reaction.

  After granulation, stirring may be performed to such an extent that the particle state is maintained and particle floating and sedimentation are prevented by using a normal stirrer while adjusting the temperature.

  When producing toner particles, known surfactants and organic / inorganic dispersants can be used as dispersion stabilizers. Among these, inorganic dispersants are preferred because they are less likely to produce harmful ultrafine powders, and because dispersion stability is obtained due to their steric hindrance, stability is not easily lost even when the reaction temperature is changed. The following are mentioned as an inorganic dispersing agent. Polyvalent metal phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate; carbonates such as calcium carbonate and magnesium carbonate; inorganic salts such as calcium metasuccinate, calcium sulfate and barium sulfate; calcium hydroxide and hydroxide Inorganic hydroxides such as magnesium and aluminum hydroxide; inorganic oxides such as silica, bentonite and alumina.

  These inorganic dispersants are preferably used alone in an amount of 0.2 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. 0.001 to 0.1 parts by mass of a surfactant may be used in combination.

  Examples of the surfactant include the following. Sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate.

  When these inorganic dispersants are used, they may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be generated and used in an aqueous medium. For example, in the case of calcium phosphate, a sodium phosphate aqueous solution and a calcium chloride aqueous solution can be mixed with high-speed stirring to produce water-insoluble calcium phosphate, which enables more uniform and fine dispersion. At the same time, a water-soluble sodium chloride salt is produced as a by-product. However, if a water-soluble salt is present in the aqueous medium, dissolution of the polymerizable monomer in water is suppressed, and an ultrafine toner based on emulsion polymerization is produced. Since it becomes difficult to generate | occur | produce, it is more convenient. The inorganic dispersant can be dissolved with an acid or an alkali after the completion of the polymerization and removed almost completely by the next step such as filtration and washing.

  In the polymerization step, the polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. When the polymerization is carried out in this temperature range, the release agent or wax to be sealed inside is precipitated by phase separation, and the encapsulation becomes more complete. Further, in order to consume the remaining polymerizable monomer, the reaction temperature can be increased to 90 to 150 ° C. at the end of the polymerization reaction. After completion of the polymerization reaction, it is filtered and washed, and then preferably dried by an air flow drying device.

  In general, toner particles obtained by removing coarse powder and fine powder out of a desired particle size range in the classification process are obtained. The classification step can be carried out by a known method used in conventional toner production, and is not particularly limited. A toner can be obtained by mixing the toner particles obtained through the classification step with an external additive such as an inorganic fine powder and adhering them to the surface of the toner particles. In the present invention, it is one of preferred modes to directly obtain the toner by omitting the classification process from the manufacturing process, or to cut the coarse powder and fine powder with high precision by performing a more accurate classification process.

  In the present invention, it is also preferable that inorganic fine particles having a number average primary particle diameter of 4 to 80 nm are added to the toner as a fluidizing agent among the external additives.

As the inorganic fine particles used in the present invention, silica, alumina and titanium oxide can be used. For example, as the silicic acid fine powder, a so-called dry method produced by vapor phase oxidation of silicon halide or dry silica called fumed silica, and wet silica produced from water glass can be used. Dry silica is preferred because it has less silanol groups on the surface and in the silica fine powder, and less production residue of Na ₂ O and SO ³⁻ . In the case of dry silica, it is also possible to obtain a composite fine powder of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the production process. . You may use them.

  The amount of inorganic fine particles having an average primary particle size of 4 to 80 nm is preferably 0.1 to 3.0% by mass with respect to the toner particles. If the addition amount is less than 0.1% by mass, the effect is not sufficient, and if it exceeds 3.0% by mass, the fixability may be lowered. In addition, content of inorganic fine powder can be quantified using the analytical curve created from the standard sample using the fluorescent X ray analysis.

  The inorganic fine particles are preferably hydrophobized in view of characteristics in a high temperature and high humidity environment. As treatment agents for hydrophobic treatment, treatment agents such as silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organic silicon compounds, and organic titanium compounds may be used alone or in combination. May be used.

  As a method for treating inorganic fine particles, there is a method of forming a hydrophobic thin film on the surface with silicone oil as a second-stage reaction after performing a silylation reaction as a first-stage reaction to eliminate silanol groups by chemical bonding. It is done.

The silicone oil may have a viscosity of 10 to 200,000 mm ² / s at 25 ° C., and more preferably from 3,000 to 80,000mm ² / s. If it is less than 10 mm ² / s, the inorganic fine particles are not stable, and the image quality tends to deteriorate due to heat and mechanical stress. If it exceeds 200,000 mm ² / s, uniform processing tends to be difficult.

  As the silicone oil used, dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, and fluorine-modified silicone oil are particularly preferable.

  As a method for treating silicone oil, inorganic fine particles treated with a silane compound and silicone oil may be directly mixed using a mixer such as a Henschel mixer, or a method of spraying silicone oil onto inorganic fine particles is used. May be. Alternatively, after dissolving or dispersing silicone oil in a suitable solvent, inorganic fine particles may be added and mixed to remove the solvent. A method using a sprayer is more preferable in that the formation of inorganic fine particle aggregates is relatively small.

  The treatment amount of the silicone oil is 1 to 40 parts by mass, preferably 3 to 35 parts by mass with respect to 100 parts by mass of the inorganic fine particles.

Silica used in the present invention, in order to impart good fluidity to the toner, the specific surface area measured by the BET method by nitrogen adsorption of preferably those in the range of 20 to 350m ² / g, 25 to 300 meters ² / g is more preferable.

  In accordance with the BET method, the specific surface area is obtained by adsorbing nitrogen gas to the sample surface using a specific surface area measuring device Autosorb 1 (manufactured by Yuasa Ionics) and calculating the specific surface area using the BET multipoint method.

Further, for the purpose of improving the cleaning property, the toner of the present invention is a toner particle having, as an external additive, fine particles close to an inorganic or organic sphere whose primary particle size exceeds 30 nm (more preferably, the primary particle size is 50 nm or more). It is one of the preferable forms to add externally. As the inorganic or organic fine particles, those having a specific surface area of less than 50 m ² / g (more preferably a specific surface area of less than 30 m ² / g) can be preferably used. Examples of such fine particles include spherical silica particles, spherical polymethylsilsesquioxane particles, and spherical resin particles.

  Other external additives may be further externally added to the toner particles within a range that does not substantially adversely affect the toner. For example, the following are mentioned. Lubricant powders such as polyfluorinated ethylene powder, zinc stearate powder, and polyvinylidene fluoride powder; abrasives such as cerium oxide powder, silicon carbide powder, and strontium titanate powder; fluidity imparting agents such as titanium oxide powder and aluminum oxide powder; Anti-caking agent. In addition, a small amount of organic fine particles or inorganic fine particles having reverse polarity can be used as a developing property improver. These external additives can also be used after the surface is hydrophobized.

  The toner produced in the present invention can be used as a one-component developer. For example, in the case of a polymerized toner containing a magnetic substance in toner particles as a one-component developer, there is a method of conveying and charging the polymerized toner using a magnet built in the developing sleeve. However, the developer is not necessarily limited to the one-component developer as described above, and may be used as a two-component developer.

  When used as a two-component developer, a magnetic carrier is used together with the toner. As the magnetic carrier, an element selected from iron, copper, zinc, nickel, cobalt, manganese and chromium is used alone or in a composite ferrite state. The magnetic carrier has a spherical shape, a flat shape, or an indeterminate shape. Furthermore, it is preferable to control the fine structure (for example, surface unevenness) of the surface state of the magnetic carrier particles. Generally, after the inorganic oxide is fired and granulated to previously generate magnetic carrier core particles, a method of coating the carrier core particles with a resin is used. For the purpose of reducing the load of the magnetic carrier on the toner, a method of obtaining a low density dispersion carrier by kneading and classifying an inorganic oxide and a resin, or a kneaded product of an inorganic oxide and a monomer directly in an aqueous medium It is also possible to use a method in which suspension polymerization is performed to obtain a true spherical magnetic carrier.

  Among these, a coated carrier obtained by coating the surface of the carrier core particle with a resin is particularly preferable. As a method of coating the surface of the carrier core particles with the resin, the resin is dissolved or suspended in a solvent and applied to the carrier core by coating, or the resin powder and the carrier core particles are mixed and attached. Can be applied.

  The substance adhering to the surface of the carrier particles varies depending on the toner material, but includes the following. Polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, styrene resin, acrylic resin, polyamide, polyvinyl butyral, aminoacrylate resin. These may be used alone or in plural.

The magnetic properties of the carrier are as follows. The magnetization intensity (σ ₁₀₀₀ ) at a magnetic field strength of 79.6 kA / m after magnetic saturation is preferably 3.77 to 37.7 μWb / cm ³ . In order to achieve higher image quality, it is more preferably 12.6 to 31.4 Wb / cm ³ . When the magnetization intensity is greater than 37.7 μWb / cm ^3, it becomes difficult to obtain a high-quality toner image. On the other hand, when it is less than 3.77 Wb / cm ³ , the magnetic binding force is also reduced, so that carrier adhesion is likely to occur.

  When a two-component developer is prepared by mixing the toner used in the present invention and a magnetic carrier, the mixing ratio is such that the toner concentration in the developer is 2 to 15% by mass, preferably 4 to 13% by mass. Usually good results are obtained.

  Each measurement method and evaluation method used in the present invention will be described below.

<Method of measuring weight average particle diameter (D4), number average particle diameter (D1), number variation coefficient>
The weight average particle diameter (D4) and number average particle diameter (D1) of the toner are measured by a fine particle size distribution measuring apparatus “Coulter Counter Multisizer 3” (registered trademark, Beckman 2) Effective measurement channel number 25,000 using “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) and attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” for measurement condition setting and measurement data analysis Measurement was performed on the channel, and the measurement data was analyzed and calculated.

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

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

  In the “Standard Measurement Method (SOM) Change Screen” of the dedicated software, set the total count in the control mode to 50000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter, Inc.) Set the value obtained using The threshold and noise level are automatically set by pressing the threshold / noise level measurement button. Also, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the aperture tube flash after measurement is checked.

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

The specific measurement method is as follows.
(1) About 200 ml of the electrolytic aqueous solution is put in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rotations / second. Then, dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the analysis software.
(2) About 30 ml of the electrolytic aqueous solution is put in a glass 100 ml flat bottom beaker, and "Contaminone N" (nonionic surfactant, anionic surfactant, organic builder pH 7 precision measurement is used as a dispersant therein. About 0.3 ml of a diluted solution obtained by diluting a 10% by weight aqueous solution of a neutral detergent for washing a vessel (made by Wako Pure Chemical Industries, Ltd.) 3 times with ion exchange water is added.
(3) Two oscillators with an oscillation frequency of 50 kHz are incorporated in a state where the phase is shifted by 180 degrees, and placed in a water tank of an ultrasonic dispersion device “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikki Bios Co., Ltd.) having an electrical output of 120 W. A fixed amount of ion-exchanged water is added, and about 2 ml of the above-mentioned Contaminone N is added to this water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.
(5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
(6) To the round bottom beaker of (1) installed in the sample stand, the electrolyte solution of (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to about 5%. . The measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) and the number average particle diameter (D1) are calculated. When the graph / volume% is set with the dedicated software, the “average diameter” on the analysis / volume statistics (arithmetic average) screen is the weight average particle size (D4), and the graph / number% is set with the dedicated software. The “average diameter” on the analysis / number statistic (arithmetic average) screen is the number average particle diameter (D1).

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 a standard deviation in the number distribution of toner particles, and D1 represents a number average particle diameter (μm) of toner particles. ]

<Measuring method of average circularity>
The average circularity of the toner is measured using a flow type particle image measuring device “FPIA-2100” (manufactured by Sysmex Corporation). Details are as follows.

First, the circularity is calculated from the following equation.
Circularity = (perimeter of a circle having the same area as the particle projection area) / (perimeter of the particle projection image)

  Here, the “particle projected area” is the area of the binarized particle image, and the “peripheral length of the particle projected image” is 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 degree of circularity is an index indicating the degree of unevenness of particles, and is 1.00 when the particles are perfectly spherical. The more complicated the surface shape, the smaller the degree of circularity.

  The average circularity C, which means the average value of the circularity frequency distribution, is calculated from the following formula (1), where ci is the circularity 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 (2) where the average circularity C, the circularity ci of each particle, and the number of measured particles are m.

  A specific measurement method is as follows. First, about 10 ml of ion-exchanged water from which impure solids and the like are previously removed is put in a glass container. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.1 ml of a diluted solution obtained by diluting the solution with ion exchange water about 3 times by mass. Further, about 0.02 g of a measurement sample is added, and dispersion treatment is performed for 2 minutes using an ultrasonic disperser to obtain a dispersion for measurement. As an ultrasonic disperser, two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser with an electric output of 120 W “Ultrasonic Dispense System Tetora 150 type” (manufactured by Nikkei Bios) Is used. A predetermined amount of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of the contamination N is added to the water tank. In that case, it cools suitably so that the temperature of this dispersion may not be 40 degreeC or more. Further, in order to suppress variation in circularity, the installation environment of the apparatus is controlled to 23 ° C. ± 0.5 ° C. so that the in-machine temperature of the flow type particle image analyzer FPIA-2100 is 26 to 27 ° C. In addition, automatic focus adjustment is performed using standard latex particles of 2 μm at regular intervals, preferably every 2 hours (for example, “RESEARCH AND TEST PARTICLES Latex Microsphere Suspensions 5200A” manufactured by Duke Scientific) is diluted with ion-exchanged water. Do.

The flow type particle image measuring apparatus was used for measuring the circularity of the toner particles, and the particle sheath “PSE-900A” (manufactured by Sysmex Corporation) was used as the sheath liquid. The dispersion prepared according to the above procedure is introduced into the flow type particle image analyzer, and the concentration of the dispersion is readjusted and measured so that the toner particle concentration at the time of measurement is about 5000 particles / μl. After the measurement, the average circularity of the toner in the range of the circle equivalent diameter of 2.00 μm or more and less than 40.02 is obtained using this data. The equivalent circle diameter is a value calculated as follows.
Equivalent circle diameter = (particle projected area / π) 1/2 × 2

  “FPIA-2100”, which is a measuring apparatus used in the present invention, has a thinner sheath flow (7 μm → 4 μm) than “FPIA-1000” which has been used for observing the shape of a conventional toner. ) And the magnification of the processed particle image. In addition, the processing resolution of the captured image is improved (256 × 256 → 512 × 512), and the accuracy of toner shape measurement is improved.

<Measurement method of total amount of organic volatile components>
Determination of the amount of organic volatile components in terms of toluene of the toner by organic volatile component analysis at a heating temperature of 150 ° C. by the headspace method can be measured as follows.

  In a headspace vial (volume: 22 ml), 300 mg of toner is precisely weighed and sealed with a crimper and a special septum coated with fluororesin using a crimper. This vial is set in a headspace sampler, and gas chromatogram (GC) analysis is performed under the following conditions. And the total area value of the peak of the obtained GC chart is calculated by data processing. At this time, an empty vial in which no toner is sealed is simultaneously measured as a blank, and a measurement value in the blank measurement is subtracted from the toner measurement data.

  On the other hand, several vials (for example, 0.1 μl, 0.5 μl, 1.0 μl) prepared by precisely weighing toluene are prepared in the vial, and each measurement is performed under the following analysis conditions before the toner sample is measured. After that, a calibration curve is prepared from the amount of toluene charged and the toluene area value.

  The amount of organic volatile component in terms of toluene can be obtained by converting the area value of the organic volatile component of the toner into the mass of toluene based on this calibration curve, and further converting it into an amount based on the toner mass.

(Measurement equipment and measurement conditions)
Headspace sampler: HEWLETT PACKARD 7694
Oven temperature: 150 ° C
Sample heating time: 60 minutes Sample loop (Ni): 1 ml
Loop temperature: 170 ° C
Transfer line temperature: 190 ° C
Pressurization time: 0.50 minutes LOOP FILL TIME: 0.01 minutes LOOP EQ TIME: 0.06 minutes INJECT TIME: 1.00 minutes GC cycle time: 80 minutes Carrier gas: He
GC: HEWLETT PACKARD 6890GC (detector: FID)
Column: HP-1 (inner diameter 0.25 μm × 30 m)
Oven: (1) 35 ° C .: Hold for 20 minutes, (2) Hold 20 ° C./min to 300 ° C. for 20 minutes Hold INJ: 300 ° C., splitless, constant pressure (20 psi) mode DET: 320 ° C.

<Method for measuring moisture content>
The moisture content in the present invention is determined by collecting 5 g of toner particles in an aluminum dish, precisely weighing it (A [g]), leaving it in a dryer set at 105 ° C. for 1 hour, ]) And a value calculated by the following formula.
Moisture content [%] = ((A−B) / A) × 100

<Measurement of residual styrene monomer in toner>
The amount of residual styrene monomer in the toner is measured by gas chromatography (GC) as follows.

  About 500 mg of toner is precisely weighed and placed in a sample bottle. About 10 g of acetone precisely weighed is added to the lid and mixed well, and then mixed well. A tabletop ultrasonic cleaner having an oscillation frequency of 42 kHz and an electric output of 125 W (for example, “B2510J-MTH”, manufactured by Branson) ) For 30 minutes. Thereafter, filtration is performed using a solvent-resistant membrane filter “Maesori Disc” (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm, and 2 μl of the filtrate is analyzed by gas chromatography. And the residual amount of a residual styrene monomer is computed with the analytical curve created beforehand using styrene.

The measurement apparatus and measurement conditions are as follows.
GC: HP 6890GC
Column: HP INNOWax (200 μm × 0.40 μm × 25 m)
Carrier gas: He (constant pressure mode: 20 psi)
Oven: (1) Hold at 50 ° C. for 10 minutes, (2) Temperature rise to 200 ° C. at 10 ° C./min, (3) Hold at 200 ° C. for 5 minutes Inlet: 200 ° C., pulsed splitless mode (20 → 40 psi, until 0.5 min)
Split ratio: 5.0: 1.0
Detector: 250 ° C. (FID)

<Image evaluation>
With respect to 100.0 parts by mass of the toner particles obtained after drying, 0.8 parts by mass of hydrophobic silica having a specific surface area of 200 m ² / g by BET method and an oxidation having a specific surface area of 100 m ² / g by BET method Toner was obtained by externally adding 0.1 part by weight of titanium.

  Using LBP-2710 (manufactured by Canon), the manufactured cartridge is filled with the manufactured toner, and an image with a printing ratio of 20% in a high-temperature and high-humidity environment (30 ° C., 80% RH) is 500 sheets in a continuous mode. The toner durability was evaluated by the method described below. The evaluation results are shown in Table 1.

(Cleanability)
The streaks on the image generated by the toner slipping through were visually evaluated.
A: Not generated at all B: Slightly generated C: Slightly generated but practically no problem D: Generated and practically problematic

(Image fog)
The fog density (%) is calculated from the difference between the whiteness of the white background portion of the printout image and the whiteness of the transfer paper measured by “REFLECTMETER MODEL TC-6DS” (manufactured by Tokyo Denshoku Co., Ltd.). Image fog was evaluated. An amberlite filter was used as the filter. If the image fog is less than 2.0%, the image is good.
A: Less than 1.0% B: 1.0% or more and less than 2.0% C: 2.0% or more and less than 3.0% D: 3.0% or more

<Evaluation of foamability of liquid level>
The liquid level of the polymer particle dispersion in the evaporation container was visually observed and evaluated according to the following criteria.
A: A state in which foaming is always suppressed.
B: The foamed layer grows when the toner particle dispersion is boiled, but then the foamed layer gradually lowers and only a few foamed layers are formed.
C: A state in which the foamed layer does not drop after reaching the evaporation container exhaust line after the foamed layer grows when the toner particle dispersion boils.
D: After the toner particle dispersion boils, the growth of the foam layer further accelerates, and the foam tip reaches the exhaust line above the evaporation container.

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

[Manufacture of styrene resin]
A reactor equipped with a dropping funnel, a Liebig condenser and a stirrer was charged with 600.0 parts by mass of xylene and heated to 135 ° C. A mixture of 100.0 parts by mass of styrene monomer, 0.1 part by mass of n-butyl acrylate and 13.0 parts by mass of di-tert-butyl peroxide was charged into a dropping funnel, and dropped into xylene at 135 ° C. over 2 hours. did. Further, solution polymerization was completed under reflux of xylene (137 ° C. to 145 ° C.) to remove xylene, and a styrene resin was obtained. The obtained styrene-based resin had a weight average molecular weight (Mw) of 3,200, Mw / Mn of 1.19, and a glass transition point (Tg) of 55 ° C.

<Example 1>
850 parts by mass of a 0.1 mol / liter Na ₃ PO ₄ aqueous solution is added to 710 parts by mass of ion-exchanged water in the granulation vessel 10 shown in FIG. While stirring at a speed of 25 m / s, the temperature was maintained at 60 ° C. To this, 68 parts by mass of a 1.0 mol / liter-CaCl ₂ aqueous solution was gradually added to prepare an aqueous dispersion medium containing a fine hardly water-soluble dispersion stabilizer Ca ₃ (PO ₄ ) ₂ .

on the other hand,
Styrene monomer 124.0 parts by mass n-butyl acrylate 36.0 parts by mass Copper phthalocyanine pigment 13.0 parts by mass The above styrene resin 40.0 parts by mass Polyester resin 10.0 parts by mass (terephthalic acid-propylene oxide modified bisphenol A (2 mol adduct) -ethylene oxide modified bisphenol A (2 mol adduct) (molar ratio 51:30:20); acid value 9; glass transition point 60 ° C. Mw = 10000, Mw / Mn = 3.20)
E-88 (manufactured by Orient Chemical Co., Ltd.) 0.8 part by mass HNP-9 (manufactured by Nippon Seiki Co., Ltd.) The above formulation consisting of 15.0 parts by mass was heated to 60 ° C., and uniformly dissolved and dispersed. To this, 20.0 parts by mass of 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate (toluene solution 50%) as a polymerization initiator was added, and a polymerizable monomer composition was added. Was prepared.

The polymerizable monomer composition is charged into the aqueous dispersion medium and stirred at 60 ° C. and N ₂ atmosphere for 15 minutes at a peripheral speed of 25 m / s with Claremix to produce a polymerizable monomer mixture. Grained.

  Thereafter, the stirring was stopped, and the contents of the granulation container were introduced into the polymerization container 12 equipped with a full zone stirring blade 5 (manufactured by Shinko Pantech Co., Ltd.) as shown in FIG.

  In the polymerization container, the internal temperature was raised to 70 ° C. and reacted for 6 hours with slow stirring to obtain a toner particle dispersion. Thereafter, the stirring was stopped, and the toner particle dispersion was introduced into the evaporation container through the liquid inlet.

  The apparatus of the aspect shown in FIG. 1 was used for the volatile component removal apparatus. The capacity of the evaporation container was 100 L, and the amount of the charged toner particle dispersion was 40 L. The toner particle dispersion in the evaporation container is withdrawn from the lower part of the evaporation container while being stirred by a stirring blade, and is sent while passing through the external circulation path using a circulation pump. Next, the toner particle dispersion was heated with saturated steam introduced into the external circulation path, and then ejected from the upper part of the evaporation tank toward the gas phase part to remove volatile components.

Detailed conditions of the volatile component removal process using the volatile component removal apparatus shown in FIG. 1 are shown below.
・ Saturated steam temperature / external circulation path Steam thermometer 1: 120 ° C
・ Saturated steam pressure P1 / External circulation path Steam pressure gauge 1: 205 kPa
・ External circulation path temperature Liquid + Steam thermometer: 110 ℃
・ Saturated steam input / external circulation route: 20 kg / hr
・ Circulating flow rate: 10 L / min
-Toner particle dispersion liquid pressure in external circulation path Liquid pressure gauge: 70 kPa
・ Evaporation container temperature Thermometer in evaporation container: 99 ℃
・ Toner particle dispersion jetting method: jetting from the piping toward the liquid level ・ Saturated water vapor from the bottom of the evaporation container: No

  In the volatile component removal step, the toner particle dispersion reached the boiling point 20 minutes after the start of the introduction of the saturated water vapor, and a fraction began to come out from the exhaust line via the condenser. The supply of saturated water vapor introduced into the external circulation path is stopped 3 hours after the start of distillate, and the toner particle dispersion in the container / circulation path is cooled by flowing cooling water into the jacket while circulating. .

  Thereafter, hydrochloric acid was added to the toner particle dispersion to dissolve calcium phosphate, washed with water, and filtered to obtain wet toner particles.

  The obtained wet toner particles were dried under the following conditions using an airflow dryer (manufactured by Seishin Enterprise Co., Ltd .: flash jet dryer: pipe diameter 0.1016 m) to obtain toner particles.

(Drying conditions)
Blowing temperature: 80 ° C
Air flow: 8m ³ / min
Wet toner particle supply amount: 30 kg / hr

  Evaluation of foamability of liquid surface in evaporation container in volatile component removal step, measurement result of weight average particle diameter (D4) of toner particles after drying, number variation coefficient, residual styrene monomer, total amount of organic volatile components, average circularity Table 3 shows the results of image evaluation.

<Example 2>
・ Saturated steam temperature / external circulation path Steam thermometer 1: 105 ° C
・ Saturated steam pressure P1 / External circulation path Steam pressure gauge 1: 123 kPa
・ External circulation path temperature Liquid + Steam thermometer: 101 ℃
・ Evaporation container temperature Thermometer in evaporation container: 97 ℃
Except that, toner particles were prepared in the same manner as in Example 1.

  In addition, evaluation of foamability of the liquid surface in the evaporation container in the volatile component removal step, weight average particle diameter (D4) of toner particles after drying, number variation coefficient, residual styrene monomer, total amount of organic volatile components, average circularity Table 3 shows the measurement results and the image evaluation results.

<Example 3>
・ Saturated steam temperature / external circulation path Steam thermometer 1: 180 ° C
・ Saturated steam pressure P1 / External circulation path Steam pressure gauge 1: 1015 kPa
・ External circulation path temperature Liquid + Steam thermometer: 160 ℃
・ Evaporation container temperature Liquid container thermometer: 102 ℃
Except that, toner particles were prepared in the same manner as in Example 1.

  In addition, evaluation of foamability of the liquid surface in the evaporation container in the volatile component removal step, weight average particle diameter (D4) of toner particles after drying, number variation coefficient, residual styrene monomer, total amount of organic volatile components, average circularity Table 3 shows the measurement results and the image evaluation results.

<Example 4>
・ Saturated steam temperature / external circulation path Steam thermometer 1: 105 ° C
・ Saturated steam pressure P1 / External circulation path Steam pressure gauge 1: 123 kPa
・ External circulation path temperature Liquid + Steam thermometer: 101 ℃
・ Circulation flow rate: 25 L / min
-Toner particle dispersion liquid pressure in external circulation path Liquid pressure gauge: 123 kPa
・ Evaporation container temperature Thermometer in evaporation container: 96 ℃
Except that, toner particles were prepared in the same manner as in Example 1.

  Since there is no pressure difference between the pressure of the toner particle dispersion in the external circulation path and the saturated water vapor introduced into the external circulation path, the saturated water vapor often does not flow smoothly.

  Also, evaluation of foamability of the liquid surface in the evaporation container in the volatile component removal step, weight average particle size (D4) of toner particles after drying, number variation coefficient, residual styrene monomer, total amount of organic volatile components, average circularity Table 3 shows the measurement results and the image evaluation results.

<Example 5>
The method of using the volatile component removal apparatus shown in FIG. 2 and ejecting toward the gas phase portion via the external circulation path is a method of ejecting the toner particle dispersion liquid onto the rotating disk rotating from the pipe. Except for the above, toner particles were prepared in the same manner as in Example 1.

  In addition, evaluation of foamability of the liquid surface in the evaporation container in the volatile component removal step, weight average particle diameter (D4) of toner particles after drying, number variation coefficient, residual styrene monomer, total amount of organic volatile components, average circularity Table 3 shows the measurement results and the image evaluation results.

<Example 6>
Except for using the volatile component removal apparatus shown in FIG. 1 and performing showering with a nozzle having a plurality of 3 mm hole diameters attached to the tip of a pipe for ejecting the toner particle dispersion liquid to the gas phase part, facing the liquid surface. Toner particles were prepared in the same manner as in Example 1.

  In the volatile component removal step, the nozzles were clogged as the processing progressed, and the jetting state was slightly uneven. When the nozzle was removed and observed after the operation was completed, a plurality of fusion products were observed.

  Also, evaluation of foamability of the liquid surface in the evaporation container in the volatile component removal step, weight average particle size (D4) of toner particles after drying, number variation coefficient, residual styrene monomer, total amount of organic volatile components, average circularity Table 3 shows the measurement results and the image evaluation results.

<Example 7>
Saturated steam is introduced from the bottom of the evaporation container,
・ Saturated water vapor temperature / lower evaporation vessel Steam thermometer 2: 120 ° C
・ Saturated water vapor pressure P1 / Evaporation vessel lower part Steam pressure gauge 2: 205kPa
・ Saturated steam input / evaporation container lower part: 4 kg / hr
・ Evaporation container temperature Liquid container thermometer: 100 ℃
Except that, toner particles were prepared in the same manner as in Example 1.

  In addition, evaluation of foamability of the liquid surface in the evaporation container in the volatile component removal step, weight average particle diameter (D4) of toner particles after drying, number variation coefficient, residual styrene monomer, total amount of organic volatile components, average circularity Table 3 shows the measurement results and the image evaluation results.

<Example 8>
Saturated steam is introduced from the bottom of the evaporation container,
・ Saturated water vapor temperature / lower evaporation vessel Steam thermometer 2: 120 ° C
・ Saturated water vapor pressure P1 / Evaporation vessel lower part Steam pressure gauge 2: 205kPa
・ Saturated steam input / evaporation container lower part: 8 kg / hr
・ Evaporation container temperature Liquid container thermometer: 101 ℃
Except that, toner particles were prepared in the same manner as in Example 1.

  In addition, evaluation of foamability of the liquid surface in the evaporation container in the volatile component removal step, weight average particle diameter (D4) of toner particles after drying, number variation coefficient, residual styrene monomer, total amount of organic volatile components, average circularity Table 3 shows the measurement results and the image evaluation results.

<Example 9>
Saturated steam is introduced from the bottom of the evaporation container,
・ Saturated water vapor temperature / lower evaporation vessel Steam thermometer 2: 180 ° C
・ Saturated water vapor pressure P1 / Lower evaporation vessel Steam pressure gauge 2: 1015 kPa
・ Saturated steam input / evaporation container lower part: 4 kg / hr
・ Evaporation container temperature Liquid container thermometer: 101 ℃
Except that, toner particles were prepared in the same manner as in Example 1.

  In addition, evaluation of foamability of the liquid surface in the evaporation container in the volatile component removal step, weight average particle diameter (D4) of toner particles after drying, number variation coefficient, residual styrene monomer, total amount of organic volatile components, average circularity Table 4 shows the measurement results and the image evaluation results.

<Example 10>
Saturated steam is introduced from the bottom of the evaporation container,
・ Saturated water vapor temperature / lower evaporation vessel Steam thermometer 2: 105 ° C
・ Saturated water vapor pressure P1 / lower part of vaporization vessel Vapor pressure gauge 2: 123 kPa
・ Saturated steam input / evaporation container lower part: 4 kg / hr
・ Evaporation container temperature Liquid container thermometer: 100 ℃
Except that, toner particles were prepared in the same manner as in Example 1.

  In addition, evaluation of foamability of the liquid surface in the evaporation container in the volatile component removal step, weight average particle diameter (D4) of toner particles after drying, number variation coefficient, residual styrene monomer, total amount of organic volatile components, average circularity Table 4 shows the measurement results and the image evaluation results.

<Example 11>
The toner is prepared in the same manner as in Example 1 except that a static mixer (manufactured by Noritake Co., Ltd.) is installed in the pipe from when saturated steam is introduced in the external circulation path until it is ejected to the gas phase. Particles were made.

  In addition, evaluation of foamability of the liquid surface in the evaporation container in the volatile component removal step, weight average particle diameter (D4) of toner particles after drying, number variation coefficient, residual styrene monomer, total amount of organic volatile components, average circularity Table 4 shows the measurement results and the image evaluation results.

<Example 12>
Using the system shown in FIG. 4, the internal temperature is raised to 70 ° C. in a polymerization vessel and reacted for 6 hours with slow stirring to obtain a toner particle dispersion. Thereafter, using the polymerization vessel as it is, toner particles were produced in the same manner as in Example 1 except that saturated water vapor was introduced into the external circulation and external circulation path to remove volatile components.

  In addition, evaluation of foamability of the liquid surface in the evaporation container in the volatile component removal step, weight average particle diameter (D4) of toner particles after drying, number variation coefficient, residual styrene monomer, total amount of organic volatile components, average circularity Table 4 shows the measurement results and the image evaluation results.

<Reference example>
The toner particles were removed in the same manner as in Example 1 except that the volatile component removing apparatus shown in FIG. 1 was used, saturated water vapor was introduced only from the bottom of the evaporation container without using an external circulation path, and the operation was performed under the following conditions. Produced.
・ Saturated water vapor temperature / lower evaporation vessel Steam thermometer 2: 120 ° C
・ Saturated water vapor pressure P1 / Evaporation vessel lower part Steam pressure gauge 2: 205kPa
・ Saturated steam input / evaporation container lower part: 4 kg / hr
・ Evaporation container temperature Thermometer in evaporation container: 98 ℃

  In addition, evaluation of foamability of the liquid surface in the evaporation container in the volatile component removal step, weight average particle diameter (D4) of toner particles after drying, number variation coefficient, residual styrene monomer, total amount of organic volatile components, average circularity Table 4 shows the measurement results and the image evaluation results.

<Comparative Example 1>
The volatile component removing apparatus shown in FIG. 5 (the difference from the volatile component removing apparatus shown in FIG. 1 is that the saturated water vapor is not directly fed into the external circulation path, but the toner particle dispersion is heated using a heat exchanger. The toner particles were prepared in the same manner as in Example 1 except that the operation was performed under the following conditions.
・ External circulation path temperature Liquid + Steam thermometer: 110 ℃
・ Circulating flow rate: 10 L / min
-Toner particle dispersion liquid pressure in external circulation path Liquid pressure gauge: 118 kPa
・ Evaporation container temperature Thermometer in evaporation container: 99 ℃
・ Toner particle dispersion jetting method: jetting from the piping toward the liquid level ・ Saturated water vapor from the bottom of the evaporation container: No

  In addition, when the heat exchanger was confirmed after completion | finish of a driving | operation, it seemed to be obstruction | occlusion with the fusion | melting material.

  Also, evaluation of foamability of the liquid surface in the evaporation container in the volatile component removal step, weight average particle size (D4) of toner particles after drying, number variation coefficient, residual styrene monomer, total amount of organic volatile components, average circularity Table 4 shows the measurement results and the image evaluation results.

<Comparative example 2>
Add 1 part of non-silicone antifoaming agent (San Nopco, product name SN deformer 180),
・ Saturated steam input / evaporation container lower part: 8 kg / hr
・ Evaporation container temperature Thermometer in evaporation container: 99 ℃
Except that, toner particles were produced in the same manner as in Reference Example 1.

  In addition, evaluation of foamability of the liquid surface in the evaporation container in the volatile component removal step, weight average particle diameter (D4) of toner particles after drying, number variation coefficient, residual styrene monomer, total amount of organic volatile components, average circularity Table 4 shows the measurement results and the image evaluation results.

<Comparative Example 3>
・ Saturated steam input / evaporation container lower part: 20 kg / hr
・ Evaporation container temperature Liquid container thermometer: 100 ℃
Except for the above, toner particles were prepared in the same manner as in the reference example.

  However, in the volatile component removal step, rapid foaming occurred when the boiling point was reached, and then the foamed layer further grew and reached the exhaust line of the evaporation vessel, so the operation was stopped.

An example of the volatile component removal apparatus applicable to this invention is shown. Another example of the volatile component removal apparatus applicable to the present invention is shown. An example of the manufacturing system containing the volatile component removal apparatus which can be applied to this invention is shown. The other example of the manufacturing system containing the volatile component removal apparatus which can be applied to this invention is shown. 1 shows a conventional volatile component removal apparatus using a heat exchanger in an external circulation path applicable to the present invention. An example of a rotating disk that disperses a toner particle dispersion applicable to the present invention toward a wall surface is shown.

1. 1. Dissolution container Stirring drive (polymerization vessel)
3. Evaporation vessel 4. Jacket 5. Stirring blade (polymerization vessel)
6). Stirring blade (evaporation vessel)
7). Liquid inlet (polymerization vessel)
8). Circulation pump9. External circulation path 10. 10. Granulation container Stirrer (granulation container)
12 Polymerization container 13. Liquid + steam thermometer14. 15. Saturated steam charging line at the bottom of the container Stirring motor (evaporation container)
16. Turntable 17. Exhaust line 18. Condenser 19. Fraction tank 20. Evaporation container liquid thermometer 21. Liquid pressure gauge 22. Saturated steam flow meter

Claims (13)

In the method for producing toner particles, the method comprises heating a toner particle dispersion containing toner particles produced in an aqueous medium and removing at least organic volatile components present in the toner particle dispersion .
The devolatilization step, using a devolatilization device having an external circulation path and evaporation container, the toner particle dispersion liquid to return to the evaporation vessel via the evaporation vessel do we said external fan 循 is ring, this time, the 100 ° C. or more saturated steam was charged into the external circulation path is the step of heating the toner particle dispersion liquid by contacting said toner particle dispersion liquid and the saturated steam directly And a method for producing toner particles.   The method for producing toner particles according to claim 1, wherein the temperature of the saturated water vapor introduced into the external circulation path is 105 to 180 ° C. The vapor pressure of saturated water vapor to be introduced into the external circulation path P1 is (kPa),
122 (kPa) ≦ P1 ≦ 1015 (kPa)
The method for producing toner particles according to claim 1, wherein the toner particles are produced as follows. When the pressure of the toner particle dispersion in the external circulation path is P2 (kPa),
P1> P2
The method for producing toner particles according to claim 1, wherein the relationship is satisfied.   5. The toner particle dispersion liquid is jetted to a gas phase portion in the evaporation container when the toner particle dispersion liquid is returned into the evaporation container through an external circulation path. A method for producing the toner particles according to claim 1.   The method for producing toner particles according to any one of claims 1 to 5, wherein saturated water vapor of 100 ° C or higher is further introduced into the toner particle dispersion in the evaporation container.   The method for producing toner particles according to claim 6, wherein the temperature of the saturated water vapor introduced into the toner particle dispersion in the evaporation container is 105 to 180 ° C. The vapor pressure P3 (kPa) of saturated water vapor introduced into the toner particle dispersion in the evaporation container is 122 (kPa) ≦ P3 ≦ 1015 (kPa).
The method for producing toner particles according to claim 6 or 7, wherein:   9. The method for producing toner particles according to claim 1, wherein the temperature of the toner particle dispersion in the evaporation container is 95 to 105.degree.   The method for producing toner particles according to claim 1, wherein the evaporation container does not have indirect heating means.   11. The method for producing toner particles according to claim 1, wherein the toner particles in the aqueous medium are coated with a particulate inorganic dispersant.   After the volatile component removal step, the total amount of organic volatile components contained in the toner particles based on the mass of the toner particles in terms of toluene by organic volatile component analysis at a heating temperature of 150 ° C. by the headspace method is 300 ppm or less. The method for producing toner particles according to claim 1, wherein the toner particles are produced.   The method for producing toner particles according to claim 1, wherein the toner particles have an average circularity of 0.955 to 0.995 after the volatile component removal step.

Images