JP2012078371A - Method for producing toner particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of toner particles by which toner particles having a sharp grain size distribution that facilitates easy preparation of a toner satisfying demands for high developability, high transfer property and low-temperature fixability, can be produced even in a system with a tendency of producing coarse particles.SOLUTION: The production method of toner particles includes: a step of preparing an aqueous medium (A) containing inorganic fine particles hardly soluble with water; a granulation step of adding a polymerizable monomer composition containing a polymerizable monomer and a colorant to the aqueous medium (A) and granulating the polymerizable monomer composition to form particles of the polymerizable monomer composition; and a polymerization step of polymerizing the polymerizable monomer included in the particles of the polymerizable monomer composition to produce toner particles. The aqueous medium (A) is prepared in a preparation chamber in which stirring means is installed. The method specifies a content volume of the preparation chamber, a discharge amount of the aqueous medium (A) discharged from the stirring blade in unit time, concentration of the inorganic particles hardly soluble with water in the aqueous medium (A), an average of the zeta potential of the inorganic fine particles hardly soluble with water in the aqueous medium (A) at a temperature during granulation and the standard deviation with respect to the above average, and a pH of the aqueous medium in the granulation step.

Description

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

  In recent years, in image formation using toner, image formation with higher definition and higher resolution is required as compared with the conventional case. As a result, toners are required to have a smaller particle size and a uniform particle size distribution. Suspension polymerization method, emulsion polymerization aggregation method, and dissolution suspension method are easy to obtain a toner having a small particle size and a uniform particle size distribution. Toners using a polymerization method such as these are attracting attention.

  In recent years, laser printers and copying machines using an electrophotographic method have been rapidly increased in speed, and toners having higher developability, higher transferability, and lower temperature fixability are required.

  The conditions required for the toner in order to achieve the above-mentioned objects simultaneously include the following. That is, in order to achieve the above-mentioned object at the same time, the toner is required to have a spherical shape and a uniform surface composition, and the toner outer layer is designed to maintain heat resistance and durability, and the toner inner layer has low temperature fixability. A toner having a so-called core-shell structure designed to have is preferably used. As a method for producing toner particles that easily obtain a toner satisfying these characteristics, a method for producing toner particles using a suspension polymerization method among the polymerization methods has attracted attention.

  The suspension polymerization method is a method of obtaining toner particles by suspending and granulating a polymerizable monomer composition containing a polymerizable monomer and a colorant in an aqueous medium and then polymerizing the suspension.

  The suspension polymerization method is an excellent method for producing toner particles capable of obtaining a toner satisfying the above-mentioned characteristics. However, depending on the combination of production conditions and materials, the particle size distribution in the suspension / granulation step may be increased. There were problems such as broadening and generation of coarse particles.

  In order to solve the above problems, proposals have been made to solve the problems by improving the poorly water-soluble inorganic fine particles used during suspension / granulation and adjusting the pH during suspension / granulation.

In Patent Document 1 causes a velocity gradient 50,000Sec ^-1 to 100,000Sec ^-1 by high speed shear agitation an aqueous medium in the adjustment process of the hardly water-soluble inorganic fine particles, under high shear of the condition the hardly water-soluble inorganic fine particles to prepare, granulated under high shear by velocity gradient 40,000Sec ^-1 to 100,000Sec ^-1 in pH6.5 or 12.0 of the aqueous medium containing the hardly water-soluble inorganic fine particles A method for producing toner particles that performs the process is disclosed.

In Patent Document 2, in the dispersion medium preparation step, the rate of adding the calcium ion-containing aqueous solution to the phosphate ion-containing aqueous solution is such that the molar amount of calcium ions with respect to the number of moles of phosphate ions in the phosphate ion-containing aqueous solution. A method for producing toner particles is disclosed, characterized in that the ratio of the numbers is 0.005 to 0.5 sec ⁻¹ .

  In Patent Document 3, the pH of an aqueous medium containing calcium phosphate obtained by mixing a phosphate aqueous solution and a calcium salt aqueous solution is adjusted to 4.0 to 6.0, and the granulation step is performed in the aqueous medium. A method for producing toner particles is disclosed.

Japanese Patent Laid-Open No. 10-312086 JP 11-119465 A JP 2000-081727 A

  The effect of stabilizing the hardly water-soluble inorganic fine particles is more preferable as the particle diameter of the hardly water-soluble inorganic fine particles is finer, and the conventional water-soluble inorganic fine particle slurry having a fine particle diameter can be obtained by the conventional example. However, the conventional example has a problem that it is difficult to uniformize the composition and crystal structure of the slightly water-soluble inorganic fine particles. Therefore, when there are many poorly water-soluble inorganic fine particles having a small positive chargeability, the poorly water-soluble inorganic fine particles cannot sufficiently adhere to the surface of the toner particles, and the dispersion stability of the toner particles becomes insufficient. There was a case. As a result, there is a problem that the coalescence of the droplets easily proceeds in the polymerization step, and the toner particles become coarse. As described above, depending on the conventional example, a desired particle size that makes it easy to obtain a toner satisfying high developability, high transferability, and low-temperature fixability, particularly in a system in which coalescence of droplets easily proceeds and coarse particles are easily generated. Obtaining a distribution of toner particles has been difficult.

  The object of the present invention is to produce toner particles that are easy to obtain a toner satisfying high developability, high transferability, and low-temperature fixability even in a system that easily generates coarse particles, and that have few coarse particles, have a spherical shape and a sharp particle size distribution. Another object is to provide a method for producing toner particles.

  As a result of intensive investigations to solve the problems of the prior art, the present inventors have found that the problems can be solved by the following configuration, and have reached the present invention.

That is, the present invention provides a step of preparing an aqueous medium (A) containing at least the hardly water-soluble inorganic fine particles, a polymerizable monomer composition containing at least a polymerizable monomer and a colorant, and the aqueous medium (A). ) In addition to a granulating step of granulating the polymerizable monomer composition in the aqueous medium (A) to form particles of the polymerizable monomer composition, the polymerizable monomer composition A method for producing toner particles comprising at least a polymerization step of polymerizing the polymerizable monomer contained in the particles of a product to produce toner particles,
The aqueous medium (A) is prepared in a preparation container provided with stirring means,
The volume of the preparation container in the preparation step of the aqueous medium (A) is V (m ³ ), and the discharge amount of the aqueous medium (A) discharged from the stirring blade per unit time is Q (m ³ / s). When
0.10 sec ⁻¹ ≦ Q / V ≦ 2.00 sec ⁻¹
And
When the water-insoluble inorganic fine particle concentration in the aqueous medium (A) is Dw,
0.50 mass% ≦ Dw ≦ 1.50 mass%
And
When the average value of the zeta potential value of the poorly water-soluble inorganic fine particles in the aqueous medium (A) at the granulation temperature is ζt, and the standard deviation with respect to the average value of the zeta potential at the granulation temperature is σt,
−5.0 mV ≦ ζt ≦ 20.0 mV
5.0mV ≦ σt ≦ 25.0mV
And
When the pH of the aqueous medium in the granulation step is pHw,
4.5 ≦ pHw ≦ 6.5
It is characterized by being.

  According to the present invention, it is possible to easily produce toner satisfying high developability, high transferability, and low-temperature fixability even in a system that easily generates coarse particles, and to produce toner particles having a sharp particle size distribution with few coarse particles. A method for producing possible toner particles is provided.

FIG. 4 is a cross-sectional explanatory view of a process cartridge according to the present invention. It is a schematic block diagram of an example of the apparatus which implements the image forming method of this invention.

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

  The method for producing toner particles of the present invention comprises a step of preparing an aqueous medium (A) containing at least water-insoluble inorganic fine particles, and a polymerizable monomer composition containing at least a polymerizable monomer and a colorant. In addition to the aqueous medium (A), a granulating step of granulating the polymerizable monomer composition in the aqueous medium (A) to form particles of the polymerizable monomer composition; And a polymerization step of polymerizing the polymerizable monomer contained in the particles of the polymerizable monomer composition to produce toner particles.

  First, the poorly water-soluble inorganic fine particles used in the present invention have a chargeable distribution over a region from positive chargeability to negative chargeability in an aqueous medium. Among these, the poorly water-soluble inorganic fine particles having positive chargeability are adsorbed by electrostatic interaction on the surface of the polymerizable monomer composition particles existing as droplets uniformly dispersed in the aqueous medium, It is thought that coalescence of droplets is physically and electrostatically suppressed.

  As described above, in general, when the concentration of the hardly water-soluble inorganic fine particles is high, the central particle size of the droplet is reduced, and when the concentration of the hardly water-soluble inorganic fine particles is low, the central particle size of the droplet is large. Diameter. Therefore, it is possible to control the central particle diameter of the droplet by controlling the concentration of the hardly water-soluble inorganic fine particles.

  However, in a system in which the negative chargeability of the polymerizable monomer composition particle surface is small, the poorly water-soluble inorganic fine particles cannot be adsorbed with sufficient adhesion to the polymerizable monomer composition particle surface was there. Specific examples thereof include a case where no polar resin is added during the production of toner particles, a case where the acid value is small even when a polar resin is added, and a case where the addition amount of the charge control agent is small. In such a case, the stability of the droplets is reduced, and the coalescence of the droplets is likely to proceed during the polymerization process, resulting in the generation of toner particles with a large proportion of coarse particles or non-spherical particles. There was a problem of ending up.

In general, the average circularity is well known as an index for evaluating the sphericity of toner particles. However, as described above, when evaluating the degree of deterioration of sphericity due to coalescence of droplets during the polymerization process, the value of “aspect ratio” of toner particles is more preferably used. The aspect ratio is an index for evaluating the acicular degree of the particles, and when the coalesced particles increase during the polymerization process and the proportion of the acicular particles increases, the aspect ratio value is significantly reduced. Have The value of the aspect ratio can be measured by, for example, a flow type particle image analyzer “FPIA-3000” (manufactured by Sysmex Corporation). The measurement principle of the flow-type particle image analyzer “FPIA-3000” (manufactured by Sysmex Corporation) is to capture flowing particles as a still image and perform image analysis. The sample added to the sample chamber is fed into the flat sheath flow cell by a sample suction syringe. The sample fed into the flat sheath flow is sandwiched between sheath liquids to form a flat flow. The sample passing through the flat sheath flow cell is irradiated with strobe light at 1/60 second intervals, and the flowing particles can be photographed as a still image. Further, since the flow is flat, the image is taken in a focused state. The particle image is captured by a CCD camera, and the captured image is subjected to image processing at an image processing resolution of 512 × 512 (0.37 × 0.37 μm per pixel), and the contour of each particle image is extracted, The maximum length D _max and the maximum length vertical length D _v-max are measured. The maximum length D _max of the particle image is a value measured as the maximum length at two points on the contour of the particle image, and the maximum vertical length D _v-max is two parallel to the maximum length D _max. It is a value measured as the shortest length connecting two straight lines vertically when the particle image contour is sandwiched between the straight lines.

Next, the aspect ratio R is obtained using the maximum length _Dmax and the maximum length vertical length _Dv-max . The aspect ratio is defined as a value obtained by dividing the maximum vertical length D _v-max by the maximum length D _max and is calculated by the following equation.
Aspect ratio R = D _v-max / D _max

  The aspect ratio R approaches 1 when there is little coalescence between particles and the particle image is more circular, and the more the coalescence between particles is, the higher the acicularity of the particle image, the smaller the aspect ratio R becomes. . When the aspect ratio R of the toner particles is small, the true sphericity of the toner particles is lowered, which may adversely affect developability and transferability. Further, the dispersibility of the colorant and the charge control agent in the toner particles may be deteriorated, and the image density may be reduced or the triboelectric charge amount may be reduced.

  In the system where the negative chargeability of the surface of the polymerizable monomer composition particles is small as described above, there is a problem that the coalescence of the liquid enemies proceeds during the polymerization process and the aspect ratio value decreases. One of the causes is that the standard deviation of the average value of the zeta potential distribution of the slightly water-soluble inorganic fine particles is relatively large.

  The zeta potential is defined as the potential of a “sliding surface” at which liquid flow starts to occur in an electric double layer called an ion fixed layer and an ion diffusion layer formed around microparticles in a solution. Depending on the surface characteristics of the microparticles, the absolute value of the zeta potential is positive (positive chargeability) or negative (negative chargeability). Moreover, it shows that the electric charge of the microparticle surface in the said solution is so large that this absolute value is large.

  In an aqueous medium, the surface of the slightly water-soluble inorganic fine particles is generally positively charged, and the magnitude of this positively charged property is the adsorption to the surface of the polymerizable monomer composition having a negatively charged property. It is known to correlate with force. Therefore, the granulation stability of the polymerizable monomer composition can be suitably controlled by defining the standard deviation with respect to the zeta potential value of the poorly water-soluble inorganic fine particles and the average value of the zeta potential.

  Further, as a factor affecting the particle size distribution, the pH of the aqueous medium in the granulation step can be further mentioned. In particular, when producing a negatively chargeable toner, a negatively chargeable polar substance is localized on the surface of the droplet in the granulation process, and the periphery of the droplet is covered with positively chargeable slightly water-soluble inorganic fine particles. It is known to stabilize. At this time, if the aqueous medium is basic, the positive chargeability of the poorly water-soluble inorganic fine particles is lowered, so that the stability of the droplet is impaired. Therefore, it is considered that the particle size distribution of the generated toner particles is deteriorated.

  In the present invention, the positive chargeability of the poorly water-soluble inorganic fine particles is kept high by adjusting the zeta potential value of the poorly water-soluble inorganic fine particles and the standard deviation of the average value of the zeta potential within an appropriate range. It is possible to stabilize the droplet even with a small amount of the slightly water-soluble inorganic fine particles. Further, by adjusting the pH in the granulation step within an appropriate range, it is possible for the polymerizable monomer composition droplets to be stably present in the aqueous medium. As described above, not only the particle diameter but also the slightly water-soluble inorganic fine particles having a uniform composition and crystal structure can be favorably adsorbed to the droplets, and as a result, toner particles having a sharp particle size distribution can be obtained.

  In the present invention, the aqueous medium containing the hardly water-soluble inorganic fine particles is prepared in a preparation container provided with a stirring means. Examples of the stirring blade or stirring means used in the present invention include the following. General agitation blades such as paddle blades, inclined paddle blades, three retracted blades, propeller blades, disk turbine blades, helical ribbon blades, anchor blades, full zone (made by Shinko Pantech), twin star (made by Shinko Pantech) ), Max Blend (manufactured by Sumitomo Heavy Industries), Supermix (manufactured by Satake Chemical Machinery Co., Ltd.), Hi-F mixer (manufactured by Soken Chemical Co., Ltd.). A stirrer having a high shearing force is also preferably used. As a stirrer having a high shearing force, Ultra Tarrax (manufactured by IKA), T.I. K. Homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) K. Commercially available products such as Philmix (manufactured by Special Machine Engineering Co., Ltd.) and Claremix (manufactured by M Technique Co., Ltd.) can be used. Among these, the one that disperses by a shearing force generated by a screen provided with a rotor that rotates at high speed and a plurality of slits surrounding the rotor, such as CLEARMIX, can be used more suitably.

In the present invention, the preparation container content volume V (m ³ ) in the preparation step of the aqueous medium (A) containing the hardly water-soluble inorganic fine particles, the discharge amount of the aqueous medium (A) discharged per unit time from the stirring blade The ratio Q / V to Q (m ³ / s) is 0.10 sec ⁻¹ or more and 2.00 sec ⁻¹ or less. More preferably, it is 0.30 or more and 1.50 or less.

  The Q / V represents the number of times (the number of circulations) that the contents of the preparation container are discharged per unit time by the stirring blade, and normally, the larger this value is, the more shear is applied. .

Here, the discharge amount Q (m ³ / s) is obtained by the following equation.
Q = Nq × n × d ³
Nq: discharge coefficient n: number of rotations of the stirring blade per unit time (r / sec)
d: Blade diameter of stirring blade (m)

Here, the discharge coefficient Nq is a unique value that is different for each stirring blade, and is a value determined by the shape of the stirring blade, the rotor shape, the screen diameter, and the like. When Q / V is 0.10 sec ^-1 or more and 2.00 sec ^-1 or less, the balance between the amount of the hardly water-soluble inorganic fine particles discharged from the stirring blade and the shearing force by the stirring blade is optimal. Thus, the composition and crystal structure of the slightly water-soluble inorganic fine particles are made uniform. Further, the particle size of the hardly water-soluble inorganic fine particles is an optimum size for adhering to the surface of the polymerizable monomer composition particles. As a result, the ratio D4 / D1 of the weight average particle diameter (D4) and the weight average particle diameter (D4) to the number average particle diameter (D1), which is an index of the particle size distribution of the toner particles, the toner particle aspect ratio. Is the optimal value. Further, since no cavitation occurs due to the rotation of the stirring blade, toner particles in which the colorant is uniformly dispersed can be obtained without adversely affecting the granulation property of the polymerizable monomer composition particles. As a result, a toner having a sufficiently high coloring power can be obtained.

  When the Q / V is less than 0.10, the discharge amount per unit time by the stirring blade becomes too small, and it becomes difficult to produce poorly water-soluble inorganic fine particles having a uniform composition and particle size. As a result, the adhesion state of the poorly water-soluble inorganic fine particles to the surface of the polymerizable monomer composition particles becomes insufficient, and the coalescence of the droplets easily proceeds. Therefore, the weight average particle diameter (D4) of the obtained toner particles ) Becomes too large. For this reason, problems such as fogging and toner scattering are caused, and more heat is required for fixing, resulting in a problem with low-temperature fixability. When the Q / V exceeds 2.00, the particle diameter of the poorly water-soluble inorganic fine particles to be generated becomes too small, and thus the surface of the polymerizable monomer composition particle is blocked by the poorly water-soluble inorganic fine particles. It becomes insufficient. As a result, the coalescence of droplets is likely to proceed as described above, and the weight average particle diameter (D4) of the obtained toner particles becomes too large. Further, cavitation due to the stirring blade may occur, and the granulation property becomes unstable. As a result, a broad particle size distribution is obtained in which the ratio D4 / D1 between the weight average particle diameter (D4) and the number average particle diameter (D1) of the obtained toner particles is large. As a result, the yield as a toner is reduced, and problems such as fogging and development streaks occur. Further, since segregation of a material such as a colorant tends to occur in the polymerizable monomer composition particles, the coloring power of the toner particles decreases.

  Adjusting the Q / V to the above range is achieved by adjusting the type of the stirring blade, the rotation speed of the stirring blade, and the volume of the adjusting container when the aqueous medium is manufactured.

  Moreover, the hardly water-soluble inorganic fine particle concentration Dw (mass%) of the aqueous medium is 0.50 or more and 1.50 or less. More preferably, it is 0.50 or more and 1.00 or less.

  When the Dw is 0.50 or more and 1.50 or less, the weight average particle diameter (D4) of the obtained toner particles is in an optimal range, and thus fogging, toner scattering, deterioration of transfer uniformity, and the like occur. Therefore, a toner excellent in developability, transferability and fixability that can be fixed at low temperature can be obtained. Moreover, when it is 0.50 or more and 1.00 or less, the said effect improves more.

  When the Dw is less than 0.50, the weight average particle diameter (D4) of the obtained toner particles becomes too large, causing problems such as fogging and toner scattering. Further, since a larger amount of heat is required at the time of fixing, the low temperature fixing property is adversely affected. When the Dw exceeds 1.50, the toner particles obtained have a weight average particle size (D4) that is too small, which makes it difficult to control the chargeability and causes problems such as deterioration in transfer uniformity. Further, the particle ratio (number%) of toner particles of 4 μm or less is increased, and segregation of a colorant, wax, charge control agent, etc. occurs in the particles of 4 μm or less, which causes adverse effects on low-temperature fixability and storage stability.

  Adjusting Dw to the above range can be achieved, for example, by adjusting the amount of each raw material added when producing the poorly water-soluble inorganic fine particles.

  Moreover, the average value ζt of the zeta potential value of the aqueous medium containing the hardly water-soluble inorganic fine particles at the granulation temperature is −5.0 mV or more and 20.0 mV or less. More preferably, it is 0.0 mV or more and 18.0 mV or less.

  When the ζt is −5.0 mV or more and 20.0 mV or less, the proportion of the hardly water-soluble inorganic fine particles having an appropriate positive charge is increased and exists as droplets uniformly dispersed in the aqueous medium. It is thought that it can adsorb | suck with the moderate adhesive force on the surface of the polymerizable monomer composition particle | grains which are. As a result, the stability of the droplets is improved, and the weight average particle diameter (D4) of the obtained toner particles is in the optimum range, thereby suppressing the occurrence of fogging, toner scattering, and deterioration of transfer uniformity. A toner excellent in developability, transferability and fixability that can be fixed is obtained. Moreover, the said effect improves more when it is 0.0 mV or more and 18.0 mV or less.

  When the ζt is less than −5.0 mV, the electrostatic interaction acting between the water-insoluble inorganic fine particles and the surface of the droplets of the polymerizable monomer composition particles becomes too small. Adhesiveness of the conductive inorganic fine particles becomes insufficient, and the weight average particle diameter (D4) of the toner particles becomes too large. If the ζt exceeds 20.0 mV, the adhesion between the poorly water-soluble inorganic fine particles and the droplet surface of the polymerizable monomer composition particles becomes too large, so Increased stability. As a result, the toner particle has a particle size (number%) of 4 μm or less and a broad particle size distribution with many fine particles. Further, since segregation of a colorant, wax, charge control agent, etc. occurs in toner particles of 4 μm or less, it causes a bad effect on low-temperature fixability and storage stability.

  In order to adjust ζt within the above range, it can be achieved, for example, by adjusting the amount and rate of addition of each raw material during the production of sparingly water-soluble inorganic fine particles.

  The standard deviation σt with respect to the average value of the zeta potential of the aqueous medium containing the hardly water-soluble inorganic fine particles at the granulation temperature is 5.0 mV or more and 25.0 mV or less. More preferably, it is 5.0 mV or more and 20.0 mV or less.

  When the σt is 5.0 mV or more and 25.0 mV or less, the dispersion of the positive charging property of the hardly water-soluble inorganic fine particles becomes an appropriate level, and the hardly water-soluble inorganic fine particles have a uniform adhesive force and a polymerizable single particle. It is thought that it can adsorb | suck to the surface of a monomer composition particle | grain. As a result, segregation of the material in the polymerizable monomer composition particles is suppressed, and toner particles with uniform material dispersibility are generated. Thereby, the coloring power of the toner particles obtained is improved.

  When the σt is less than 5.0 mV, the adhesive force between the poorly water-soluble inorganic fine particles and the droplet surface of the polymerizable monomer composition particles becomes too large, so Increased stability. As a result, the toner particle has a particle size (number%) of 4 μm or less and a broad particle size distribution with many fine particles. Further, since segregation of a colorant, wax, charge control agent, etc. occurs in toner particles of 4 μm or less, it causes a bad effect on low-temperature fixability. When the σt exceeds 25.0 mV, the dispersion of positive chargeability of the poorly water-soluble inorganic fine particles becomes too large, so that the adsorptive power to the surface of the polymerizable monomer composition particles is reduced. As a result, the stability of the droplets is lowered, and the weight average particle diameter (D4) of the obtained toner particles may be increased. In addition, the aspect ratio value of the toner particles is lowered, causing problems such as fogging, toner scattering, and deterioration of transfer uniformity.

  In order to adjust σt within the above range, for example, by adjusting the amount of each raw material added during the production of the hardly water-soluble inorganic fine particles, the addition rate, and the composition ratio when each raw material is added during the production of the hardly water-soluble inorganic fine particles. Achievable. It can also be achieved by adding an ionic substance in order to promote the formation reaction of the hardly water-soluble inorganic fine particles, or adjusting the temperature and the manufacturing time during the production of the hardly water-soluble inorganic fine particles.

  Moreover, pHw which is pH of the aqueous medium in a granulation process is 4.5 or more and 6.5 or less. More preferably, it is 4.8 or more and 5.5 or less.

  When the pHw is 4.5 or more and 6.5 or less, the positively chargeable property of the poorly water-soluble inorganic fine particles is improved, so that the weight average particle diameter (D4) and the number average particle diameter of the obtained toner particles are obtained. The ratio D4 / D1 of (D1) and the particle ratio (number%) of toner particles of 4 μm or less are optimum values. As a result, a good particle size distribution with few small and coarse particles can be obtained, so fog, development streaks, deterioration of transfer uniformity, etc. are suppressed, and low temperature fixing is possible, and developability, transferability and fixability are excellent. Toner is obtained. Moreover, when it is 4.8 or more and 5.5 or less, the said effect improves further.

  When the pHw is less than 4.5, the weight average particle diameter (D4) of the obtained toner particles becomes too large due to the solubilization of the poorly water-soluble inorganic fine particles. Further, the aspect ratio value of the toner particles is lowered, and a broad particle size distribution with many coarse particles is obtained. For this reason, problems such as fogging, development streaks, and toner scattering occur, and more heat is required for fixing, which causes problems in low-temperature fixability. When the pHw exceeds 6.5, the positive chargeability of the poorly water-soluble inorganic fine particles decreases, and the ratio D4 / D1 of the weight average particle diameter (D4) to the number average particle diameter (D1) of the toner particles and the toner The particle ratio (number%) of 4 μm or less of particles increases. Further, since segregation of a colorant, wax, charge control agent, etc. occurs in toner particles of 4 μm or less, it causes a bad effect on low-temperature fixability. As a result, the yield as a toner is reduced, and problems such as fogging and development streaks occur.

  Adjusting the pHw to the above range can be achieved, for example, by adjusting the amount of acid and base to be added.

  The sedimentation half-life of the aqueous medium containing the hardly water-soluble inorganic fine particles used in the present invention is preferably 200 or more and 1400 minutes or less. More preferably, it is 400 minutes or more and 1000 minutes or less.

  The sedimentation half-life refers to the volume of sediment when the prepared water-soluble inorganic fine particles are adjusted to a certain concentration and a uniformly suspended aqueous medium is placed in a 100 ml sedimentation tube and allowed to stand at 25 ° C. Time to reach 50 ml. That is, the sedimentation half-life is an index indicating the dispersion stability of the hardly water-soluble inorganic fine particles.

  When the settling half-life is 200 minutes or more and 1400 minutes or less, aggregation of the hardly water-soluble inorganic fine particles can be prevented while the hardly water-soluble inorganic fine particles maintain an appropriate particle size. As a result, the poorly water-soluble inorganic fine particles have optimum dispersion stability, and can be instantaneously adsorbed on the droplet surface of the polymerizable monomer composition particles in the granulation step. Therefore, the ratio D4 / D1 of the weight average particle diameter (D4) and the number average particle diameter (D1) of the toner particles can be further improved, and the dispersibility of each material in the toner particles can be made more uniform. It becomes.

  Adjusting the sedimentation half-life to the above range can be achieved by adjusting the primary particle size of the slightly water-soluble inorganic fine particles by adjusting the stirring speed at the time of manufacturing the aqueous medium or adjusting the temperature at the time of manufacturing the aqueous medium. It is possible by adjusting.

  Examples of the poorly water-soluble inorganic fine particles used in the present invention include calcium phosphate salts, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, Examples include calcium sulfate, barium sulfate, bentonite, silicon oxide, and aluminum oxide. Among them, it is particularly preferable to use calcium phosphate salts. Specific examples of calcium phosphate salts include hydroxyapatite, fluoroapatite, calcium deficient apatite, carbonate apatite, tricalcium phosphate, calcium hydrogen phosphate, calcium dihydrogen phosphate, calcium diphosphate, tetracalcium phosphate, octacalcium phosphate And mixtures thereof are preferably used. In view of the positive chargeability and acid solubility of these calcium phosphates, it is more preferable that the calcium phosphates used in the present invention contain hydroxyapatite. By containing hydroxyapatite, the positive chargeability of the hardly water-soluble inorganic fine particles is further improved, and the adsorptivity between the hardly water-soluble inorganic fine particles and the polymerizable monomer composition can be further increased. For this reason, it is possible to further suppress the coalescence of the droplets. Therefore, it is possible to obtain toner particles with a sharper particle size distribution, and a toner having excellent developability and fixability can be obtained. Further, these poorly water-soluble inorganic fine particles may be used as they are, but considering the control of the particle diameter of the poorly water-soluble inorganic fine particles, it is preferable to generate the hardly water-soluble inorganic fine particles in the dispersion medium. For example, in the case of hydroxyapatite, it may be obtained by mixing a sodium phosphate aqueous solution and a calcium chloride solution with high stirring.

  The toner of the present invention preferably further contains a polar resin (shell binder resin) that forms a shell for the purpose of forming a core-shell structure. With such a design, heat resistance is improved. In addition, improvement in developability, transferability and fixability can be achieved, and better characteristics than conventional toner can be obtained.

  Examples of the polar resin used in the present invention include polymers of nitrogen-containing monomers such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate, or copolymers of nitrogen-containing monomers and styrene-unsaturated carboxylic acid esters; Nitrile monomers such as acrylonitrile; halogen-containing monomers such as vinyl chloride; unsaturated carboxylic acids such as acrylic acid and methacrylic acid; unsaturated dibasic acids; unsaturated dibasic acid anhydrides; Or a styrene monomer such as a styrene monomer, a styrene-acrylic acid ester copolymer, or a styrene-methacrylic acid ester copolymer; a polyester; an epoxy resin.

  The acid value (mgKOH / g) of the polar resin used in the present invention is preferably 5.0 or more and 30.0 or less. When the acid value of the polar resin is 5.0 or more and 30.0 or less, each droplet in the granulation step is combined with highly water-soluble inorganic fine particles having high positive charge and a small standard deviation with respect to the average value of zeta potential. The polar resin content in between is equalized. In addition, polar resin is unevenly distributed on the droplet surface. From the above, the droplet is further stabilized. Therefore, the ratio D4 / D1 of the weight average particle diameter (D4) and the number average particle diameter (D1) of the toner particles to be obtained and the particle ratio (number%) of 4 μm or less of the toner particles are more optimal values. Good particle size distribution with few coarse particles is obtained. Therefore, it is possible to obtain a toner having further excellent developability in which generation of fog and development streaks is suppressed. Furthermore, since the polar resin is unevenly distributed on the toner surface, a core-shell structure is formed, so that the storage stability is excellent, the charging stability, the rising of the charge and the durability are good, and the winding resistance at high temperature is good. In addition, a toner excellent in heat resistance, developability and fixability can be obtained.

  Setting the acid value of the polar resin within the above range can be achieved by adjusting the amount of the acid component in the polar resin.

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

  Examples of the monofunctional polymerizable monomer include the following. Styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, p- Styrenic polymerizable monomers such as n-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-phenyl styrene Body; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n- Octyl Acryle Acrylic monomers such as methyl methacrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate; methyl methacrylate , Ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n -Nonyl methacrylate, diethyl phosphate ethyl methacrylate, dibutyl phosphate Methacrylic polymerizable monomers such as ethyl acetate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl formate; vinyl methyl ether, vinyl ethyl ether, Vinyl ethers such as vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

  The following are mentioned as a polyfunctional polymerizable monomer. Diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 2,2 '-Bis (4- (acryloxy-diethoxy) phenyl) propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol Dimethacrylate, 1,3-bu Lenglycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2′-bis (4- (methacryloxy-diethoxy) phenyl) propane, 2,2′-bis ( 4-methacryloxy-polyethoxy) phenyl) propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, divinyl ether.

  In the present invention, the above-described monofunctional polymerizable monomers are used alone or in combination of two or more, or the above-mentioned monofunctional polymerizable monomers and polyfunctional polymerizable monomers are used in combination. .

  The polyfunctional polymerizable monomer can also act as a crosslinking agent. The crosslinking agent can be used at a ratio of 0.001 to 15 parts by mass with respect to 100 parts by mass of the monofunctional polymerizable monomer. Examples of the polyfunctional polymerizable monomer include divinyl compounds such as divinylaniline, divinyl sulfide, and divinyl sulfone, and compounds having three or more vinyl groups, in addition to those described above.

  As the black colorant used in the present invention, carbon black, a magnetic material, and a toned color of each color using the following yellow / magenta / cyan colorant are used. In particular, since dyes and carbon black have many polymerization-inhibiting properties, care must be taken when using them.

  Examples of the yellow colorant used in the present invention include compounds represented by monoazo compounds, disazo compounds, condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specifically, the following C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 128, 129, 138, 147, 150, 151, 154, 155, 168, 180, 185, 214, C.I. I. Solvent Yellow 93, 162 etc. can be illustrated.

  The magenta colorant used in the present invention includes monoazo compounds, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylenes. Compounds. Specifically, the following C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, 238, 254, 269, C.I. I. Pigment Violet 19 etc. can be illustrated.

  Examples of the cyan colorant used in the present invention include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66, and the like.

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

  Furthermore, the toner of the present invention may be a magnetic toner containing a magnetic material as a colorant. In this case, the magnetic material can also serve as a colorant. Magnetic materials include the following iron oxides such as magnetite, hematite and ferrite; metals such as iron, cobalt and nickel, or aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium and bismuth of these metals. And alloys of metals such as cadmium, calcium, manganese, selenium, titanium, tungsten and vanadium, and mixtures thereof.

  The magnetic material is preferably a surface-modified magnetic material, more preferably a material subjected to a hydrophobic treatment with a surface modifying agent that is a substance that does not inhibit polymerization. Examples of such surface modifiers include silane coupling agents and titanium coupling agents.

  These magnetic materials have a number average particle diameter of 2 μm or less, preferably 0.1 to 0.5 μm. The amount to be contained in the toner particles is 20 to 200 parts by mass, particularly preferably 40 to 150 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  As the polymerization initiator, an oil-soluble initiator and / or a water-soluble initiator is used. Preferably, the half-life at the reaction temperature during the polymerization reaction is 0.5 to 30 hours. When the polymerization reaction is carried out at an addition amount of 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer, a polymer having a maximum between 10,000 and 40,000 is usually obtained. A toner having strength and melting characteristics can be obtained.

  The following are mentioned as an example of a polymerization initiator. 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, t-butylperoxy 2-ethylhexanoate, t-butylper Oxypivalate, t-butylperoxyisobutyrate, t-butylperoxyneodecanoate, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide Such peroxide polymerization initiators. Particularly preferred is a polymerization initiator that produces an ether compound upon decomposition during the polymerization reaction.

  In the present invention, a known chain transfer agent or polymerization inhibitor may be used to control the degree of polymerization of the polymerizable monomer.

  The polymerizable monomer composition used in the present invention preferably further contains a polymer or copolymer having a sulfonic acid group, a sulfonic acid group, or a sulfonic acid ester group.

  When the polymerizable monomer composition contains a polymer or copolymer having a sulfonic acid group, a sulfonic acid group or a sulfonic acid ester group, the standard deviation with respect to the average value of the zeta potential is small, and the positive chargeability is difficult. By combining with water-soluble inorganic fine particles, the content of the polymer or copolymer having a sulfonic acid group or the like between the droplets is equalized in the granulation step. Further, the polymer or copolymer having the sulfonic acid group or the like is unevenly distributed on the surface of the polymerizable monomer composition, whereby the droplets are further stabilized. Therefore, the ratio D4 / D1 of the weight average particle diameter (D4) and the number average particle diameter (D1) of the toner particles to be obtained and the particle ratio (number%) of 4 μm or less of the toner particles are more optimal values. Good particle size distribution with few coarse particles is obtained. Therefore, it is possible to obtain a toner having further excellent developability in which generation of fog and development streaks is suppressed. Furthermore, when the polymer or copolymer having a sulfonic acid group or the like is unevenly distributed on the toner surface, a toner having excellent charge stability and rising of charge and further excellent developability can be obtained.

  And it is preferable that the polymer which has the said sulfonic acid group etc. contains 0.01 thru | or 5.0 mass part with respect to 100 mass parts of polymerizable monomers. More preferably, it is 0.1 to 3.0 parts by mass. When the polymer having a sulfonic acid group or the like is 0.01 to 5.00 parts by mass, the effect is further improved.

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

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

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

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

  In addition to the polymer having a sulfonic acid group or the like in the side chain, the toner of the present invention may further contain another charge control agent in order to stabilize charging characteristics. As the charge control agent, known ones can be used, and in particular, a charge control agent that has a high charging speed and can stably maintain a constant triboelectric charge amount is preferable. Further, when the toner is produced by a direct polymerization method, a charge control agent having a low polymerization inhibition property and substantially free from a solubilized product in an aqueous dispersion medium is particularly preferable.

  Specific examples of the negative charge control agent compound include salicylic acid, alkyl salicylic acid, dialkyl salicylic acid, metal compounds of aromatic carboxylic acids such as naphthoic acid and dicarboxylic acid, metal salts or metal complexes of azo dyes or azo pigments, boron compounds, Examples thereof include silicon compounds and calixarene.

  The amount of use of these charge control agents is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and the 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 binder resin or polymerizable monomer. Further, when added externally, 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 toner of the present invention, 0.001 to 0.1 parts by mass of a surfactant may be used for fine dispersion of the poorly water-soluble inorganic fine particles. This is for accelerating the desired action of the poorly water-soluble inorganic fine particles, and specific examples thereof include the following. Sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate.

  The toner of the present invention may contain inorganic fine powder in addition to toner particles containing at least a binder resin and a colorant, and the inorganic fine powder is preferably externally added.

  The addition amount of the inorganic fine powder is preferably 0.01 to 5.0 parts by mass, more preferably 0.1 to 4.0 parts by mass with respect to 100 parts by mass of the toner particles. If the addition amount is within the above range, a sufficient fluidity improving effect can be obtained while suppressing a decrease in fixing property. The inorganic fine powder preferably has a number average primary particle size of 4 to 80 nm, and more preferably 4 to 60 nm.

  Examples of the inorganic fine powder include metal oxides such as titanium oxide powder, aluminum oxide powder, and zinc oxide powder; silica fine powder such as wet process silica and dry process silica. In the present invention, as described above, it is particularly preferable to contain fine titanium oxide powder. The metal oxide or silica fine powder may be surface-treated with a treatment agent such as a silane coupling agent, a titanium coupling agent, or silicone oil. Furthermore, aluminum dope silica, strontium titanate, and hydrotalcite are mentioned. In addition, as an external additive, vinylidene fluoride fine powder, fluorine-based resin powder such as polytetrafluoroethylene fine powder; fatty acid metal salts such as zinc stearate, calcium stearate, lead stearate, etc. can be added. .

  The physical property value measuring method of the present invention will be described below.

<Measurement of zeta potential of aqueous medium containing hardly water-soluble inorganic fine particles>
In the present invention, the zeta potential value (ζt) and the standard deviation (σt) of the average value of the zeta potential of the aqueous medium containing the hardly water-soluble inorganic fine particles are measured by Zetasizer Nano ZS (manufactured by MALVERN), measurement condition setting, and Calculation was performed using the attached dedicated software “Dispersion Technology software 4.20” (manufactured by MALVERN) for analyzing measurement data. The specific measurement method is as follows.
<1> Immediately after the production of the aqueous medium containing the hardly water-soluble inorganic fine particles was completed, the temperature was raised to a temperature (usually 50 ° C. to 70 ° C.) for granulating the polymerizable monomer composition. Thereafter, a part of the aqueous medium was immediately extracted from the preparation container and transferred to a syringe having a volume of 10 ml. Next, the tip of the syringe is inserted into one sample port of a capillary cell for measuring zeta potential (DTS1060-Clear disposable zeta cell) which has been washed twice with ion exchange water, and the aqueous medium is slowly poured so as not to generate bubbles. It is. After confirming that the liquid was injected into the capillary part without any gap, the two sample ports were capped.
<2> The cell was inserted into the cell holder of the measuring device, and the lid of the detection unit was closed. Measurement was performed under the following measurement conditions.
F (ka) selection Model: Smoluchowski
Dispersant: Water
Temperature: Granulation temperature (usually 50 ° C to 70 ° C)
Result Calculation: General Purpose
<3> After the measurement, on the displayed measurement result report screen, the value of “Zeta Potential” was the average value of the zeta potential, and the value of “Zeta Deviation” was the standard deviation with respect to the average value of the zeta potential.

<PH of aqueous medium>
The pH of the aqueous medium containing the hardly water-soluble inorganic fine particles is measured by a pH meter using a glass electrode as follows according to the measurement method specified in 7 of JIS Z8802-1984.
First, the pH meter is adjusted by the method specified in 7 of JIS Z8802-1984 after washing the electrode.

  Next, take an aqueous medium containing hardly water-soluble inorganic fine particles of 10 to 25 mL so that the measured value does not change, so that the liquid temperature of the aqueous suspension does not change more than ± 0.1 ° C., The measurement is performed with a pH meter having the glass electrode specified in 7 of JIS Z8802-1984 described above. Depending on the reproducibility of the pH meter used, the values measured three times are averaged until they agree within a range of ± 0.02, ± 0.05, or ± 0.1, respectively. And the pH of the aqueous medium.

<Measurement of sedimentation half-life of aqueous medium containing sparingly water-soluble inorganic fine particles>
The sedimentation half-life of the aqueous medium containing the hardly water-soluble inorganic fine particles was measured as follows. First, the concentration in the aqueous medium of the slightly water-soluble inorganic fine particles was adjusted to 0.5% by weight, and the aqueous medium was suspended uniformly. Then, it put into a 100 ml sedimentation tube and left still at 25 degreeC. The time until the sediment volume reached 50 ml was measured, and this time was defined as the sedimentation half-life.

<X-ray diffraction pattern of slightly water-soluble inorganic fine particles>
The X-ray diffraction pattern of the generated slightly water-soluble inorganic fine particles was measured using a sample horizontal strong X-ray diffractometer RINT TTRII (manufactured by Rigaku Corporation) under the following conditions.
X-ray tube: Cu
Tube voltage: 50KV
Tube current: 300mA
Scan mode: continuous scan speed: 4 deg. / Min
Sampling interval: 0.020 deg.
Start angle (2θ): 3 deg.
Stop angle (2θ): 60 deg.
Divergence slit: Open divergence length limit slit: 10.00mm
Scattering slit: Open light receiving slit: Using open curved monochromator

  Assignment of the obtained X-ray diffraction peak was performed using analysis software “Jade 6” manufactured by Rigaku Corporation.

<Method of measuring weight average particle diameter of toner particles>
The weight average particle diameter (D4) and the number average particle diameter (D1) of the toner particles are determined by a fine particle size distribution measuring apparatus “Coulter Counter Multisizer 3” (registered trademark, Beckman) using a pore electric resistance method equipped with an aperture tube of 100 μm.・ The number of effective measurement channels is 25, using the special software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter) for setting measurement conditions and analyzing measurement data. Measurement was performed with 1000 channels, 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, the dedicated software was set 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 placed in a glass-made 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. 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 placed in a 100 ml flat bottom beaker made of glass, and “Contaminone N” (nonionic surfactant, anionic surfactant, organic builder consisting of organic builder) is used as a dispersant. 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 disperser “Ultrasonic Dissipation System Tetora150” (manufactured by Nikkiki Bios) with 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> About 10 mg of toner particles are added to the electrolytic aqueous solution little by little in a state where the electrolytic aqueous solution in the beaker of <4> is irradiated with ultrasonic waves, 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> The electrolyte solution of <5> in which toner particles are dispersed with a pipette is dropped into the round bottom beaker of <1> installed in a sample stand so that the measured concentration is about 5%. To do. Measurement is performed until the number of measured particles reaches 50,000.
<7> The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) and the number average particle diameter (D1) are calculated. The “average diameter” on the analysis / volume statistics (arithmetic average) screen when the graph / volume% is set with the dedicated software is the weight average particle diameter (D4).

<Method for measuring toner particle aspect ratio>
The aspect ratio of the toner particles is measured by the flow type particle image analyzer “FPIA-3000” (manufactured by Sysmex Corporation) under the measurement and analysis conditions during the calibration operation.

  A specific measurement method is as follows. First, about 20 ml of ion-exchanged water from which impure solids are removed in advance 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 0.2 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. In that case, it cools suitably so that the temperature of a dispersion liquid may become 10 to 40 degreeC. As the ultrasonic disperser, a desktop type ultrasonic cleaner disperser (for example, “VS-150” (manufactured by VervoCrea)) having an oscillation frequency of 50 kHz and an electric output of 150 W is used. Ion exchange water is added, and about 2 ml of the above-mentioned Contaminone N is added to this water tank.

  For the measurement, the above-mentioned flow type particle image analyzer equipped with “UPlanApro” (magnification 10 times, numerical aperture 0.40) as an objective lens is used, and the particle sheath “PSE-900A” (manufactured by Sysmex Corporation) It was used. The dispersion prepared in accordance with the above procedure is introduced into the flow type particle image analyzer, and 3000 toner particles are measured in the HPF measurement mode and in the total count mode. Then, the binarization threshold at the time of particle analysis is set to 85%, the analysis particle diameter is limited to the equivalent circle diameter of 1.985 μm or more and less than 39.69 μm, and the aspect ratio of the toner particles is obtained.

  In the measurement, automatic focus adjustment is performed using standard latex particles (eg, “RESEARCH AND TEST PARTICLES Latex Microsphere Suspensions 5200A” manufactured by Duke Scientific) diluted with ion-exchanged water before starting the measurement. Thereafter, it is preferable to perform focus adjustment every two hours from the start of measurement.

  In the examples of the present application, a flow-type particle image analyzer that has been issued a calibration certificate issued by Sysmex Corporation, which has been calibrated by Sysmex Corporation, was used. Measurement was performed under the measurement and analysis conditions when the calibration certificate was received, except that the analysis particle diameter was limited to a circle equivalent diameter of 1.985 μm or more and less than 39.69 μm.

<Acid value of polar resin>
The acid value of the polar resin was measured by the following method.

The acid value is the number of mg of potassium hydroxide necessary for neutralizing the acid contained in 1 g of the sample. The acid value of the polar resin is measured according to JIS K 0070-1992. Specifically, it is measured according to the following procedure.
(1) Preparation of Reagent 1.0 g of phenolphthalein is dissolved in 90 ml of ethyl alcohol (95 vol%), and ion exchanged water is added to make 100 ml to obtain a phenolphthalein solution.
7 g of special grade potassium hydroxide is dissolved in 5 ml of water, and ethyl alcohol (95 vol%) is added to make 1 l. In order not to touch carbon dioxide, etc., put in an alkali-resistant container and let stand for 3 days, then filter to obtain a potassium hydroxide solution. The obtained potassium hydroxide solution is stored in an alkali-resistant container. The factor of the potassium hydroxide solution was as follows: 25 ml of 0.1 mol / l hydrochloric acid was placed in an Erlenmeyer flask, a few drops of the phenolphthalein solution were added, titrated with the potassium hydroxide solution, and the hydroxide required for neutralization. Determined from the amount of potassium solution. As the 0.1 mol / l hydrochloric acid, one prepared according to JIS K 8001-1998 is used.
(2) Operation (A) Main test 2.0 g of a pulverized polar resin sample is precisely weighed into a 200 ml Erlenmeyer flask, and 100 ml of a mixed solution of toluene / ethanol (2: 1) is added and dissolved over 5 hours. Subsequently, several drops of the phenolphthalein solution is added as an indicator, and titration is performed using the potassium hydroxide solution. The end point of titration is when the light red color of the indicator lasts for about 30 seconds.
(B) Blank test Titration is performed in the same manner as described above, except that no sample is used (that is, only a mixed solution of toluene / ethanol (2: 1) is used).
(3) The acid value is calculated by substituting the obtained result into the following formula.
A = [(C−B) × f × 5.61] / S

  Here, A: acid value (mgKOH / g), B: addition amount (ml) of a potassium hydroxide solution in a blank test, C: addition amount (ml) of a potassium hydroxide solution in this test, f: potassium hydroxide Solution factor, S: sample (g).

  Next, an example of an image forming method using the toner of the present invention will be described with reference to FIGS. However, the present invention is not limited to this.

<Process cartridge>
FIG. 1 is a schematic cross-sectional view of a process cartridge 7 (hereinafter also referred to as “cartridge”) that can be suitably used in an image forming apparatus to which an image forming method of the present invention is applied.

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

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

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

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

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

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

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

<Image forming apparatus>
FIG. 2 is a schematic sectional view showing an example of an image forming apparatus to which the image forming method of the present invention is applied. The image forming apparatus 100 has four image forming stations Pa, Pb, Pc, and Pd arranged in parallel in the vertical direction. The process cartridges 7 (7a, 7b, 7c, 7d) are detachably attached to the image forming stations Pa, Pb, Pc, Pd by attachment means (not shown). The magenta, cyan, yellow, and black cartridges 7a, 7b, 7c, and 7d have the same configuration.

  In this schematic diagram, the image forming stations Pa, Pb, Pc, and Pd are arranged side by side with a slight inclination in the vertical direction, but they may be arranged in the vertical direction without being inclined. Further, the process cartridge 7 may be the same as that illustrated in FIG. 1 or may be different.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  In FIG. 2, a method using a heating roller for the fixing unit 20 is illustrated, but other fixing methods can also be suitably used for the image forming method of the present invention. As an example, there is an apparatus for fixing a toner image by heating a heat-resistant polymer film using a heating element.

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

(Manufacture of aqueous medium 1)
5.0 parts of sodium phosphate was added to water to prepare 10,000 g of a 25.0% aqueous sodium phosphate solution. On the other hand, 3.2 parts of calcium chloride was added to water to prepare 10,000 g of a 16.1 wt% calcium chloride aqueous solution.

Next, 200 parts of water was added to a preparation container having an internal volume of 200 liters, heated to 60 ° C., and then a high-speed rotary shearing stirrer CLEARMIX CLM-30S (M Technique Co., Ltd., [used rotor The maximum diameter of 120 mm, clearance 0.5 mm] was used and stirred at a rotational speed of 3,000 r / min. When a ratio Q / V between the content volume V (m ³ ) in the preparation container and the discharge amount Q (m ³ / s) of the aqueous medium discharged per unit time from the stirring blade of the stirrer was calculated 0.86 (times / sec).

  Next, while the high-speed stirring was continued, the inside of the container was purged with nitrogen, and the sodium phosphate aqueous solution and the calcium chloride aqueous solution were simultaneously added dropwise thereto at a dropping rate of 160 ml / min. During this time, the Ca / P molar ratio was maintained at approximately 1.67.

  After 60 minutes, the dropping was completed, and then 2.0 parts of 10% hydrochloric acid was added while continuing stirring to adjust the pH of the aqueous medium to 5.0. Thereafter, stirring was further continued under the same conditions for 30 minutes to obtain an aqueous medium 1.

  The resulting aqueous medium 1 had a sedimentation half-life of 416 minutes. Further, when the zeta potential of the aqueous medium 1 at 60 ° C. was measured, they were ζt = 8.1 mV and σt = 12.0 mV. Further, 10.0 parts of an aqueous medium prepared under the same conditions was filtered using a membrane filter (C080A047A, pore size 0.8 μm, manufactured by Advantech), and the filtrate was washed with 100.0 parts of ion-exchanged water. A white solid was obtained. The obtained solid was dried at 40 ° C. for 24 hours using a vacuum dryer. When the X-ray diffraction measurement of the solid after drying was performed, it was confirmed from the peak position and intensity of the obtained XRD pattern that the generated solid was calcium phosphate salts containing hydroxyapatite. Moreover, when the calcium phosphate salt concentration in the aqueous medium 1 was determined from the mass after drying the solid, the concentration was 1.09%.

(Manufacture of aqueous medium 2)
In the production example of the aqueous medium 1, the rotational speed of the high-speed rotary shear stirrer CLEARMIX CLM-30S (M Technique Co., Ltd., [maximum rotor diameter 120 mm, clearance 0.5 mm]) was changed to 500 r / min. An aqueous medium 2 was produced in the same manner except that. A ratio Q / V between the volume V (m ³ ) of the preparation container and the discharge amount Q (m ³ / s) of the aqueous medium (A) discharged from the stirring blade per unit time was calculated as follows. 14 (times / sec).

(Manufacture of aqueous medium 3)
In the production example of the aqueous medium 1, the rotational speed of the high-speed rotary shear stirrer CLEARMIX CLM-30S (manufactured by M Technique Co., Ltd. [maximum rotor diameter 120 mm, clearance 0.5 mm]) is set to 6,700 r / min. A water-based medium 3 was produced in the same manner except that it was changed to. A ratio Q / V of the volume V (m ³ ) of the preparation container and the discharge amount Q (m ³ / s) of the aqueous medium (A) discharged from the stirring blade per unit time was calculated. 91 (times / sec).

(Manufacture of aqueous medium 4)
In the production example of the aqueous medium 1, the aqueous medium 4 was produced in the same manner except that the amount of sodium phosphate added was changed to 2.7 parts and the amount of calcium chloride added was changed to 1.8 parts. When the calcium phosphate salt concentration in the aqueous medium 4 was determined, the concentration was 0.61% by mass.

(Manufacture of aqueous medium 5)
In the production example of the aqueous medium 1, the aqueous medium 5 was produced in the same manner except that the amount of sodium phosphate added was changed to 6.4 parts and the amount of calcium chloride added was changed to 4.1 parts. When the calcium phosphate salt concentration in the aqueous medium 5 was determined, the concentration was 1.40% by mass.

(Manufacture of aqueous medium 6)
In the production example of the aqueous medium 1, the aqueous medium 6 was produced in the same manner except that the amount of sodium phosphate added was changed to 6.0 parts. When the zeta potential of the aqueous medium 6 at 60 ° C. was measured, they were ζt = −3.2 mV and σt = 12.8 mV.

(Manufacture of aqueous medium 7)
An aqueous medium 7 was produced in the same manner as in the production example of the aqueous medium 1 except that the amount of calcium chloride added was changed to 3.8 parts. When the zeta potential of the aqueous medium 7 at 60 ° C. was measured, they were ζt = 18.4 mV and σt = 13.6 mV.

(Manufacture of aqueous medium 8)
In the production example of the aqueous medium 1, the aqueous medium 8 was produced in the same manner except that the dropping rate of the aqueous sodium phosphate solution and the aqueous calcium chloride solution was changed to 50 ml / min and the dropping time was changed to 200 minutes. When the zeta potential of the aqueous medium 8 at 60 ° C. was measured, ζt = 10.3 mV and σt = 5.8 mV.

(Manufacture of aqueous medium 9)
In the production example of the aqueous medium 1, the aqueous medium 9 was produced in the same manner except that the dropping rate of the aqueous sodium phosphate solution and the aqueous calcium chloride solution was changed to 830 ml / min and the dropping time was changed to 12 minutes. When the zeta potential of the aqueous medium 9 at 60 ° C. was measured, ζt = 6.2 mV and σt = 23.7 mV.

(Manufacture of aqueous medium 10)
An aqueous medium 10 was produced in the same manner as in the production example of the aqueous medium 1 except that the amount of 10% hydrochloric acid added was changed to 2.6 parts. The pH of the aqueous medium 10 was 4.5.

(Manufacture of aqueous medium 11)
An aqueous medium 11 was produced in the same manner as in the production example of the aqueous medium 1 except that the amount of 10% hydrochloric acid added was changed to 1.5 parts. The pH of the aqueous medium 11 was 6.4.

(Manufacture of aqueous medium 12)
In the production example of the aqueous medium 1, the aqueous medium 12 was produced by the same method except that the water temperature in the container before dropping the sodium phosphate aqueous solution and the calcium chloride aqueous solution was changed to 67 ° C. The resulting aqueous medium 12 had a sedimentation half-life of 151 minutes. Further, when the zeta potential of the aqueous medium 12 at 60 ° C. was measured, they were ζt = 9.2 mV and σt = 8.2 mV.

(Manufacture of aqueous medium 13)
In the production example of the aqueous medium 1, the aqueous medium 13 was produced by the same method except that the water temperature in the container before dropping the sodium phosphate aqueous solution and the calcium chloride aqueous solution was changed to 51 ° C. The resulting aqueous medium 13 had a sedimentation half-life of 1484 minutes. Further, when the zeta potential of the aqueous medium 13 at 60 ° C. was measured, they were ζt = 6.7 mV and σt = 15.1 mV.

(Manufacture of aqueous medium 14)
In the production example of the aqueous medium 1, an aqueous medium 14 was produced in the same manner except that 4.4 parts of magnesium chloride was used instead of calcium chloride. The resulting aqueous medium 14 had a sedimentation half-life of 343 minutes. Further, when the zeta potential of the aqueous medium 14 at 60 ° C. was measured, they were ζt = 3.9 mV and σt = 21.0 mV. Further, 10.0 parts of an aqueous medium prepared under the same conditions was filtered using a membrane filter (C080A047A, pore size 0.8 μm, manufactured by Advantech), and the filtrate was washed with 100.0 parts of ion-exchanged water. A white solid was obtained. The obtained solid was dried at 40 ° C. for 24 hours using a vacuum dryer. When X-ray diffraction measurement of the solid after drying was performed, it was confirmed from the peak position and intensity of the obtained XRD pattern that the main component of the generated solid was magnesium phosphate. Moreover, when the magnesium phosphate salt density | concentration in the aqueous medium 14 was calculated | required from the mass after drying of solid, the density | concentration was 1.01 mass%.

(Manufacture of aqueous medium 15)
After adding 200 parts of water to a container with an internal volume of 200 liters and heating to 60 ° C., high-speed rotary shear stirrer CLEARMIX CLM-30S (M Technique Co., Ltd., [maximum rotor diameter 120 mm used) , Clearance 0.5 mm]) and agitation at a rotational speed of 3,000 r / min. To this, 0.1 part of sodium chloride and 5.0 parts of sodium phosphate were added, and stirring was continued for 30 minutes. Thereafter, 3.2 parts of calcium chloride was added, and stirring was further continued for 30 minutes. Thereafter, 2.0 parts of 10% hydrochloric acid was added to adjust the pH of the aqueous medium to 5.2. Thereafter, stirring was continued for 30 minutes under the same conditions to obtain an aqueous medium 15. When the zeta potential of the aqueous medium 15 at 60 ° C. was measured, they were ζt = 9.2 mV and σt = 14.2 mV.

(Manufacture of aqueous medium 16)
In the production example of the aqueous medium 1, the rotation speed of the high-speed rotary shear stirrer CLEARMIX CLM-30S (M Technique Co., Ltd., [maximum rotor diameter 120 mm, clearance 0.5 mm]) was changed to 300 r / min. An aqueous medium 16 was produced in the same manner except that. A ratio Q / V between the volume V (m ³ ) of the preparation container and the discharge amount Q (m ³ / s) of the aqueous medium (A) discharged from the stirring blade per unit time was calculated as follows. 09 (times / sec).

(Manufacture of aqueous medium 17)
In the production example of the aqueous medium 1, the rotational speed of the high-speed rotary shear stirrer CLEARMIX CLM-30S (manufactured by M Technique Co., Ltd., [maximum diameter of rotor used: 120 mm, clearance: 0.5 mm]) is 7,500 r / min. A water-based medium 17 was produced in the same manner except that it was changed to. A ratio Q / V between the volume V (m ³ ) of the preparation container and the discharge amount Q (m ³ / s) of the aqueous medium (A) discharged from the stirring blade per unit time was calculated. 14 (times / sec).

(Manufacture of aqueous medium 18)
In the production example of the aqueous medium 1, an aqueous medium 18 was produced by the same method except that the amount of sodium phosphate added was changed to 1.8 parts and the amount of calcium chloride added was changed to 1.1 parts. When the calcium phosphate salt concentration in the aqueous medium 18 was determined, the concentration was 0.41% by mass.

(Manufacture of aqueous medium 19)
In the production example of the aqueous medium 1, an aqueous medium 19 was produced by the same method except that the amount of sodium phosphate added was changed to 7.3 parts and the amount of calcium chloride added was changed to 4.7 parts. When the calcium phosphate salt concentration in the aqueous medium 19 was determined, the concentration was 1.58% by mass.

(Manufacture of aqueous medium 20)
In the production example of the aqueous medium 1, the aqueous medium 20 was produced by the same method except that the amount of sodium phosphate added was changed to 7.0 parts. When the zeta potential of the aqueous medium 20 at 60 ° C. was measured, they were ζt = −8.2 mV and σt = 13.4 mV.

(Manufacture of aqueous medium 21)
In the production example of the aqueous medium 1, an aqueous medium 21 was produced by the same method except that the amount of calcium chloride added was changed to 4.5 parts. When the zeta potential of the aqueous medium 21 at 60 ° C. was measured, they were ζt = 24.2 mV and σt = 10.9 mV.

(Manufacture of aqueous medium 22)
In the production example of the aqueous medium 1, the aqueous medium 22 was produced in the same manner except that the dropping rate of the aqueous sodium phosphate solution and the aqueous calcium chloride solution was changed to 25 ml / min and the dropping time was changed to 400 minutes. When the zeta potential of the aqueous medium 22 at 60 ° C. was measured, they were ζt = 13.1 mV and σt = 4.0 mV.

(Manufacture of aqueous medium 23)
In the production example of the aqueous medium 1, the aqueous medium 23 was prepared in the same manner except that the dropping rate of the sodium phosphate aqueous solution and the calcium chloride aqueous solution was changed to 1,250 ml / min and the dropping time was changed to 8 minutes. did. When the zeta potential of the aqueous medium 23 at 60 ° C. was measured, they were ζt = 4.8 mV and σt = 27.7 mV.

(Manufacture of aqueous medium 24)
An aqueous medium 24 was produced in the same manner as in the production example of the aqueous medium 1 except that the amount of 10% hydrochloric acid added was changed to 3.5 parts. The pH of the aqueous medium 24 was 4.1.

(Manufacture of aqueous medium 25)
An aqueous medium 25 was produced in the same manner as in the production example of the aqueous medium 1 except that the amount of 10% hydrochloric acid added was changed to 1.0 part. The pH of the aqueous medium 25 was 6.8.

[Toner Production Example 1]
After adding 200 parts of aqueous medium 1 to a container with an internal volume of 200 liters and heating to 60 ° C., high speed rotary shear stirrer CLEARMIX CLM-30S (M Technique Co., Ltd. The major axis was 150 mm and the clearance was 0.5 mm]).

Further, the following materials were uniformly dissolved and mixed at 100 r / min with a propeller stirrer to prepare a resin-containing monomer.
Styrene ... 45 parts n-butyl acrylate ... 25 parts polar resin 1: styrene-methyl methacrylate-methacrylic acid copolymer (copolymerization ratio = 95.5: 2.0: 2.5, Mw = 12000, Tg = 89 ° C., acid value = 12.0 mgKOH / g, Mw / Mn = 2.1) 15.0 parts

Further, the following formulation was dispersed with an attritor to obtain a fine colorant-containing monomer.
・ Styrene ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 30 parts ・ C. I. Pigment Blue 15: 3 ························································· 6.0 parts ..0.3 parts

  Next, after the fine particle colorant-containing monomer and the resin-containing monomer are mixed to obtain an adjustment liquid, the adjustment liquid is heated to 60 ° C., and wax (Fischer-Tropsch wax: melting point) 10 parts of 78.0 ° C. was added.

  Thereafter, 8.0 parts of a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition. The polymerizable monomer composition was put into the aqueous medium, and stirred at a rotational speed of 3,000 r / min for 30 minutes for granulation.

  Thereafter, the mixture was transferred to a propeller type stirring device and reacted at 70 ° C. for 5 hours while stirring at 100 r / min, then heated to 80 ° C. and further reacted for 5 hours to produce toner particles. After completion of the polymerization reaction, the residual monomer was removed under heating and reduced pressure, and after cooling, diluted hydrochloric acid was added to dissolve the hardly water-soluble inorganic fine particles. Further, washing with water was repeated several times, followed by drying at 40 ° C. for 72 hours using a dryer to obtain toner particles 1.

  The obtained toner particles 1 are classified. To 100 parts of the classified toner particles, 1.5 parts of silica fine particles having an average primary particle size of 40 nm are added as an external additive, and a Henschel mixer (Mitsui Miike Chemical Industries ( The toner 1 was obtained by mixing.

  Table 1 shows the physical properties of the toner.

[Toner Production Example 2]
Toner 2 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 2. Table 1 shows the physical properties of the toner.

[Toner Production Example 3]
Toner 3 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 3. Table 1 shows the physical properties of the toner.

[Toner Production Example 4]
A toner 4 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 4. Table 1 shows the physical properties of the toner.

[Toner Production Example 5]
Comparative toner 5 was obtained in the same manner as in Toner Production Example 1 except that aqueous medium 1 was changed to aqueous medium 5. Table 1 shows the physical properties of the toner.

[Toner Production Example 6]
Toner 6 was obtained in the same manner as in Toner Production Example 1 except that aqueous medium 1 was changed to aqueous medium 6. Table 1 shows the physical properties of the toner.

[Toner Production Example 7]
Toner 7 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 7. Table 1 shows the physical properties of the toner.

[Toner Production Example 8]
A toner 8 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 8. Table 1 shows the physical properties of the toner.

[Toner Production Example 9]
A toner 9 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 9. Table 1 shows the physical properties of the toner.

[Toner Production Example 10]
Toner 10 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 10. Table 1 shows the physical properties of the toner.

[Toner Production Example 11]
Toner 11 was obtained in the same manner as in Toner Production Example 1 except that aqueous medium 1 was changed to aqueous medium 11. Table 1 shows the physical properties of the toner.

[Toner Production Example 12]
A toner 12 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 12. Table 1 shows the physical properties of the toner.

[Toner Production Example 13]
A toner 13 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 13. Table 1 shows the physical properties of the toner.

[Toner Production Example 14]
A toner 14 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 14. Table 1 shows the physical properties of the toner.

[Toner Production Example 15]
In Toner Production Example 1, polar resin 1 was changed to polar resin 2 (styrene-methyl methacrylate-methacrylic acid copolymer (copolymerization ratio = 95.0: 4.2: 0.8, Mw = 12000, TgB = 91. Toner 15 was obtained in the same manner except that the acid value was changed to 5 ° C., acid value = 4.3 mgKOH / g, Mw / Mn = 2.1)). Table 1 shows the physical properties of the toner.

[Toner Production Example 16]
In Toner Production Example 1, polar resin 1 is treated with polar resin 3 (styrene-methacrylic acid copolymer (copolymerization ratio = 95.0: 5.0, Mw = 12000, TgB = 92.3 ° C., acid value = 32. Toner 16 was obtained in the same manner except that 1 mg KOH / g, Mw / Mn = 2.4)). Table 1 shows the physical properties of the toner.

[Toner Production Example 17]
In the toner particle 1 production example, the toner 17 was prepared in the same manner except that the addition part of styrene was changed to 50.0 parts and the addition part of n-butyl acrylate was changed to 20.0 parts, and the polar resin 1 was not used. Got. Table 1 shows the physical properties of the toner.

[Toner Production Example 18]
A toner 18 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 15. Table 1 shows the physical properties of the toner.

[Toner Comparative Production Example 1]
Comparative toner 1 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 16. Table 1 shows the physical properties of the toner.

[Toner Comparative Production Example 2]
Comparative toner 2 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 17. Table 1 shows the physical properties of the toner.

[Toner Comparative Production Example 3]
Comparative toner 3 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 18. Table 1 shows the physical properties of the toner.

[Toner Comparative Production Example 4]
Comparative toner 4 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 19. Table 1 shows the physical properties of the toner.

[Toner Comparative Production Example 5]
Comparative toner 5 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 20. Table 1 shows the physical properties of the toner.

[Toner Comparative Production Example 6]
Comparative toner 6 was obtained in the same manner as in Toner Production Example 1 except that aqueous medium 1 was changed to aqueous medium 21. Table 1 shows the physical properties of the toner.

[Toner Comparative Production Example 7]
Comparative toner 7 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 22. Table 1 shows the physical properties of the toner.

[Toner Comparative Production Example 8]
Comparative toner 8 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 23. Table 1 shows the physical properties of the toner.

[Toner Comparative Production Example 9]
Comparative toner 9 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 24. Table 1 shows the physical properties of the toner.

[Toner Comparative Production Example 10]
Comparative toner 10 was obtained in the same manner as in Toner Production Example 1 except that the aqueous medium 1 was changed to the aqueous medium 25. Table 1 shows the physical properties of the toner.

[Example 1]
Toner 1 is a non-magnetic one-component developer, and a commercially available laser printer LBP-5400 (manufactured by Canon) is used as an image forming apparatus, and the color of A4 is 23 ° C. and 50% relative humidity. Image evaluation was performed using laser copier paper (Canon, 80 g / m ² ). The remodeling points of the evaluation machine are as follows.

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

  The cartridge used for evaluation was a cyan cartridge. That is, the product toner was extracted from a commercially available cyan cartridge, the inside was cleaned by air blow, and 150 g of the toner according to the present invention was filled for evaluation. In addition, the product toner was extracted from each of the magenta, yellow, and black stations, and evaluation was performed by inserting magenta, yellow, and black cartridges in which the toner remaining amount detection mechanism was disabled.

  Under the above conditions, in a high temperature and high humidity (30 ° C., 80% RH) environment, an image with a printing ratio of 0.5% is intermittently printed up to 10,000 sheets (that is, developed for 10 seconds every time one sheet is printed out). The printer was paused, and a printout was made in a mode in which the preliminary operation of the developing device at the time of restarting promotes toner deterioration. At that time, image evaluation was performed on the items described below after the initial stage and after the endurance of 10,000 sheets.

(1) Low-temperature fixability A solid image with a toner loading of 0.60 mg / cm ² is formed, the fixing temperature is modulated every 120 ° C. to 5 ° C., and the resulting fixed image is symbolized. The temperature at which the peeling of the image was arithmetically averaged by the reduction rate (%) of the reflection density and became 10% or less was determined as the fixing start temperature.
A: Less than 140 ° C. (good)
B: 140 ° C. or higher and lower than 145 ° C. (no practical problem)
C: 145 ° C or higher and lower than 150 ° C (practical limit)
D: 150 ° C. or higher (problematic problems)

(2) High-temperature offset resistance The toner is applied at the center of the front end of the recording material to form a solid image of 5 cm × 5 cm area at an amount of 0.60 mg / cm ² , and the rear end of the recording material in the paper passing direction when passing through the fixing device Measure the temperature of the surface of the fixing heating part when a hot offset phenomenon occurs (a phenomenon in which a part of the fixed image adheres to the surface of the fixing member and then fixes on the recording material in the next round), The temperature was determined as the hot offset phenomenon occurrence temperature, and was evaluated based on the following evaluation criteria.
A: 190 ° C or higher (good)
B: 185 ° C or higher and lower than 190 ° C (no problem in practical use)
C: 180 degreeC or more and less than 185 degreeC (practical limit)
D: Less than 180 ° C. (problem in practical use)

(3) Image density Using an A4 Canon color laser copier paper (81.4 g / m ² ), in the image output test, a solid image was output after printing 10,000 sheets, and the density was evaluated. did. The image density was measured by using a “Macbeth reflection densitometer RD918” (manufactured by Macbeth Co.) according to the attached instruction manual to measure the relative density with respect to an image of a white background portion having a document density of 0.00.
A: 1.40 or more (good)
B: 1.35 or more and less than 1.40 (no problem in practical use)
C: 1.00 or more and less than 1.35 (practical limit)
D: Less than 1.00 (practical problem)

(4) Charging uniformity The particle size distribution of the toner in the CRG after initial and after 10,000 sheets is measured according to the above-mentioned method of measuring the weight average particle size (D4), and each of the obtained weight average particle sizes (D4 ) Based on the following formula, the particle size change rate was calculated and evaluated based on the following criteria. The more uniform the charge distribution of each toner, the more uniformly the toner of each particle diameter is consumed due to durability, so the change rate of the weight average particle diameter (D4) becomes smaller.

Initial weight average particle diameter (D4) / weight average particle diameter after 10,000 sheets (D4) × 100
= Particle size change rate (%)
A: 95 ≦ particle size change rate (%) ≦ 100 (good)
B: 85 ≦ particle size change rate (%) <95 (no problem in practical use)
C: 75 ≦ particle size change rate (%) <85 (practical limit)
D: Particle size change rate (%) <75 (practical problem)

(5) Fog For the measurement of fog, the reflectance of the non-image part of the standard paper and the printout image was measured using a reflection densitometer manufactured by Tokyo Denshoku Co., Ltd. and REFECTECTOMER MODEL TC-6DS. A green filter was used as a filter used in the measurement. The fog was calculated from the measurement results by the following formula and evaluated according to the following criteria.
Fog (reflectance:%) = reflectance on standard paper (%) − reflectance of sample non-image area (%)
A: Fog (reflectance) is less than 0.5% (good)
B: Fog (reflectance) of 0.5% or more and less than 1.0% (no problem in practical use)
C: fog (reflectance) of 1.0% or more and less than 2.0% (practical limit)
D: fog (reflectance) is 2.0 or more (practical problem)

(6) Circumferential streaks After printing 10,000 sheets, the developer container was disassembled and the surface and edges of the toner carrier were visually observed. The criteria are shown below.
A: There is no streak in the circumferential direction due to the foreign matter sandwiched between the toner regulating member and the toner carrying member due to toner destruction or fusion at the surface or edge of the toner carrying member (good)
B: Some foreign matter is caught between the toner carrier and the toner end seal (no problem in practical use)
C: One to four circumferential streaks can be seen at the end (practical limit)
D: 5 or more streaks in the circumferential direction can be seen in the whole area (practical problem)

(7) Transfer uniformity Halftone images after printing 100 sheets and 10,000 sheets were evaluated by transferring them to Canon color laser copier paper (81.4 g / m ² ) and Fox River Bond (90 g / m ² ). . The criteria are shown below.
A: Canon color laser copier paper and Fox even at 10,000 sheets
Both River Bonds show good transfer uniformity (good)
B: When the number of samples is 10,000, Fox River Bond shows some inferior transfer uniformity (no problem in practical use)
C: Slightly inferior transfer uniformity is recognized by Fox River Bond at the time of 100 sheets and 10,000 sheets (practical limit)
D: Inferior transfer uniformity is observed in Fox River Bond when 100 sheets and 10,000 sheets are sampled (practical problem)

(8) Contamination in main body / cartridge due to scattering of toner In order to evaluate the balance between chargeability and fluidity of toner, the contamination of toner around the cartridge after printing 10,000 sheets was observed.
A: No contamination by toner around the cartridge and the cartridge in the main body is observed (good)
B: Contamination due to a small amount of toner is observed on the cartridge (no problem in practical use)
C: Contamination due to the toner around the cartridge and the cartridge in the main body is observed.
Does not affect cartridge installation / removal (practical limit)
D: The area around the cartridge and the cartridge in the main unit is very dirty with toner, and there is an adverse effect on the attachment and detachment of images and cartridges (problems in practice)

(9) Toner degradation Toner degradation was evaluated by calculating the rate of change in solid image density at the initial stage and after 10,000 sheets. That is, the concentration change rate was calculated from each obtained concentration based on the following formula, and evaluation was performed based on the following criteria.
Solid image density after 10,000 sheets / initial solid image density × 100 = density change rate (%)
A: 95 ≦ concentration change rate (%) ≦ 100 (good)
B: 85 ≦ concentration change rate (%) <95 (no problem in practical use)
C: 75 ≦ concentration change rate (%) <85 (practical limit)
D: Concentration change rate (%) <75 (practical problem)

  When the toner 1 was evaluated under the above conditions, the toner 1 had good low-temperature fixability and high-temperature offset resistance. In addition, sufficient image density was exhibited, charging uniformity was good, and circumferential streaks and fog levels were also good. The transferability level was also good. Detailed results are shown in Table 2.

[Examples 2 to 18]
Toner 2 to toner 18 were evaluated under the same conditions as in Example 1. Detailed results are shown in Table 2.

[Comparative Examples 1 to 10]
Comparative toners 1 to 10 were evaluated under the same conditions as in Example 1. Detailed results are shown in Table 2.

  Pa, Pb, Pc, Pd Image forming station, 1 (1a to 1d) Photosensitive drum (image carrier), 2 (2a to 2d) Charging means, 3 (3a to 3d) Scanner unit, 4 (4a to 4d) Developing means, 4A developing unit, 5 electrostatic transfer device, 6 (6a to 6d) cleaning means, 7 (7a to 7d) process cartridge, 11 electrostatic transfer belt, 12 (12a to 12d) transfer roller, 13 belt drive roller 14a, 14b, driven roller, 15 tension roller, 16 feeding unit, 17 cassette, 18 feeding roller, 19 registration roller, 20 fixing unit, 21a heating roller, 21b pressure roller, 22 suction roller, 23 delivery roller, 24 paper discharge unit, 31 cleaning frame (cartridge frame), 5 Toner storage chamber, 40 Development roller (toner carrier), 41 Toner container (developer storage), 42 Toner transport mechanism, 43 Toner supply roller, 44 Toner regulating member (blade), 45 (45a, 45b, 45e) ) Development frame (cartridge frame), 47, 48 coupling hole, 50 cleaner unit, 60 cleaning blade, 100 image forming apparatus main body, S recording medium (recording material sheet)

Claims (4)

Adding a polymerizable monomer composition containing at least a polymerizable monomer and a colorant to the aqueous medium (A), the step of preparing an aqueous medium (A) containing at least the hardly water-soluble inorganic fine particles, A granulation step of granulating the polymerizable monomer composition in an aqueous medium (A) to form particles of the polymerizable monomer composition, included in the particles of the polymerizable monomer composition A method of producing toner particles comprising at least a polymerization step of polymerizing the polymerizable monomer to produce toner particles,
The aqueous medium (A) is prepared in a preparation container provided with stirring means,
The volume of the preparation container in the preparation step of the aqueous medium (A) is V (m ³ ), and the discharge amount of the aqueous medium (A) discharged from the stirring blade per unit time is Q (m ³ / s). When
0.10 sec ⁻¹ ≦ Q / V ≦ 2.00 sec ⁻¹
And
When the water-insoluble inorganic fine particle concentration in the aqueous medium (A) is Dw,
0.50 mass% ≦ Dw ≦ 1.50 mass%
And
When the average value of the zeta potential value of the poorly water-soluble inorganic fine particles in the aqueous medium (A) at the granulation temperature is ζt, and the standard deviation with respect to the average value of the zeta potential at the granulation temperature is σt,
−5.0 mV ≦ ζt ≦ 20.0 mV
5.0mV ≦ σt ≦ 25.0mV
And
When the pH of the aqueous medium in the granulation step is pHw,
4.5 ≦ pHw ≦ 6.5
A method for producing toner particles, wherein:   2. The method for producing toner particles according to claim 1, wherein the sedimentation half-life of the hardly water-soluble inorganic fine particles in the aqueous medium (A) is from 200 minutes to 1400 minutes.   The method for producing toner particles according to claim 1, wherein the hardly water-soluble inorganic fine particles contain hydroxyapatite.   The polymerizable monomer composition further contains a polar resin, and the acid value of the polar resin is 5.0 (mgKOH / g) or more and 30.0 (mgKOH / g) or less. The method for producing toner particles according to any one of 1 to 3.

Images