JP4663506B2 - Method for producing toner particles - Google Patents

Description

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

  Conventionally, in electrophotography, an electric latent image is formed on a photoreceptor by various means, and then the latent image is developed with toner, and the toner image is transferred to a transfer material such as paper as necessary. Thereafter, the toner image is fixed by heating, pressure, heating pressure or solvent vapor.

  In general, toner is roughly classified into pulverized toner and chemical toner. In the pulverized toner, a colorant is melt-mixed in a thermoplastic resin and uniformly dispersed, and then the melt-kneaded product is cooled and solidified. The kneaded product is pulverized by a pulverizer, and the pulverized product is classified by a classifier. Toner particles having a desired particle diameter are obtained. In this classification step, toner particles having a fine powder size and toner particles having a coarse powder size are generated in addition to a predetermined toner particle size. For this reason, various ideas have been made for the reuse of toner particles having a predetermined outer diameter generated in the manufacturing method. For example, the generated coarse particle size toner particles are pulverized and pulverized by returning to the pulverization step. Further, since the generated fine particle size toner particles have a problem in terms of environment and production cost when discarded, a predetermined amount is recycled by, for example, returning to the kneading process described above (for example, see Patent Document 1). A pulverized toner is manufactured by adding a predetermined additive to the pulverized toner particles thus obtained.

On the other hand, chemical toners have been proposed for production of various other toners such as a solution suspension method and a suspension polymerization method. For example, in the suspension polymerization method, a colorant is dispersed in a polymerizable monomer to obtain a polymerizable monomer mixture, and then a polymerization initiator and, if necessary, a crosslinking agent, a charge control agent, and other additives are uniformly added. after the dissolved or dispersed allowed polymerizable monomer composition, the polymerizable monomer composition is dispersed using a suitable stirrer in an aqueous medium containing a dispersion stabilizer, simultaneously polymerizable monomer Then, toner particles having a desired particle diameter are obtained, and a predetermined additive is added to produce a toner (see, for example, Patent Document 2).

  In this method, stirring in the aqueous medium described above is the most important operation for efficiently obtaining a desired particle size. In other words, if the agitation is in an ideal state, the obtained toner particles have a sharp particle size distribution, so that the classification step for uniforming the particle size can be omitted or toner particles can be obtained in a high yield even if classification is performed. Can do. However, it is very difficult to obtain this ideal agitation. For example, to generate micron-order toner particles from the polymerizable monomer composition described above, a shearing force generated by the rotation of the stirring blade is used. In general, in order to obtain a sharp particle size distribution of the toner particles obtained, it is effective to increase the stirring rotational speed and apply a high shear force.

  However, when the rotational speed is increased, bubbles due to cavitation start to be generated around the stirring blade. Since bubbles due to the cavitation deteriorate the stirring efficiency, the sharpening of the toner particles may be stopped at a certain rotation speed or higher, or the particle size distribution may be deteriorated. In addition, this cavitation may cause harm called a cavitation erosion to the stirring blade and may significantly deteriorate the durability of the stirring blade. Further, when the speed of the stirring blade is increased, the free surface of the gas-liquid interface is disturbed, and bubbles are involved from the gas phase. This bubble also deteriorates the stirring efficiency. As a result, as with cavitation, the toner particle sharpening is adversely affected.

  As described above, the speeding up of the stirring rotation speed has no effect or has an adverse effect at a certain rotation speed or higher, and there is a limit to sharpening the particle size distribution.

  On the other hand, in recent years, with the diversification of needs by users, high-definition images such as photographic image quality are required for electrophotographic images. One effective means for obtaining a high-definition image in an electrophotographic image is sharpening of toner particles as a developer. However, as described above, since there is a limit to sharpening the particle size distribution by stirring, recently, it is necessary to perform classification under conditions that are more severe than those in the past in a classification process for making the particle diameters of toner particles uniform. In other words, the classification yield is worse than before, and the amount of non-predetermined toner generated is increasing. Further, in some cases, the polymerized toner is designed to have a core-shell structure having at least two layers in which a releasable component at the time of fixing is included due to its manufacturing characteristics. For this reason, there is a problem that the toner particles outside the predetermined particle size distribution divided by the classification process cannot be simply reused like the pulverized toner. In order to solve this problem, kneading is carried out for the purpose of reducing the insoluble resin component contained in the non-predetermined toner particles with respect to the THF solvent to obtain a non-predetermined toner adjustment powder, A device has been devised such as introduction into a monomer or a polymerizable monomer composition (see, for example, Patent Document 3). Although this method is an excellent recycling method, the process is complicated and multi-staged, resulting in an increase in toner production cost.

Japanese Patent Laid-Open No. 5-34976 Japanese Patent Laid-Open No. 51-14895 JP2004-219785

  An object of the present invention is to provide a method for producing toner particles that solves the above-described problems. That is, an object of the present invention is to provide a method for producing toner particles by a chemical method, in which the particle size distribution is sharp and a high-precision image can be obtained.

  As a result of intensive studies, the present inventors have sharpened the particle size distribution by a granulation method that suppresses the generation of bubbles by entrainment of bubbles and cavitation in the granulation step of generating toner particles of micron order from the colorant composition. And the present invention was completed by finding that a high-definition image can be obtained.

That is, the present invention, the granulation process to produce particles of colorant composition in the granulation tank at least a colorant composition containing a colorant and a polymerizable monomer in an aqueous medium, the granulated tank at least a polymerization step of a polymerizable monomer to polymerize to produce the toner particles in the particles of the coloring composition in the polymerization tank in communication with, the resulting post-processing lines cormorants subsequent process of toner particles In a method for producing toner particles containing:
The colorant composition is granulated in an aqueous medium using an apparatus comprising a granulation tank and a stirrer to produce the particles of the colorant composition;
The stirring device includes a stirring blade that rotates at high speed, a stirring shaft, and a stirring chamber, and the peripheral speed of the stirring blade is 17 to 40 m / s.
When the internal volume of the granulation tank is A and the volume of the gas layer inside the granulation tank is B, the gas layer ratio B / A is expressed by the following formula (1)
0.05 ≧ B / A (1)
Satisfied,
A liquid ring tank communicating with the upper direction of the granulation tank is provided, shower water or an aqueous medium in the liquid ring tank is introduced into the granulation tank, and a gas phase part of the liquid ring tank is pressurized, Pressurizing the communicating granulation tank;
The method for producing toner particles, wherein the granulation step in the granulation tank is performed under pressure, and the release direction of the pressurization is a direction of the polymerization tank positioned below the granulation tank. It is.

  According to the present invention, it is possible to provide a production method for efficiently producing toner particles capable of realizing a high-definition image such as a photographic image quality. Furthermore, it is possible to provide a production method for efficiently producing toner particles having a sharp particle size distribution.

  FIG. 1 is a preferred example of the system used in the present invention, but is not limited thereto. The present invention is used in various chemical toner production methods including a solution suspension method and a suspension polymerization method, and is preferably used in a suspension polymerization method.

  FIG. 1 is a preferred example showing a method for producing toner particles when the present invention is applied to a suspension polymerization method.

  In FIG. 1, 1 is a dissolution tank, 2 is a dissolution agitation device, 3 is a granulation tank, 4 is a granulation agitation device, 5 is a liquid seal tank, 6 is a liquid seal tank agitation device, 7 is a polymerization tank, and 8 is a polymerization tank. Stirring device, 9 is a pressure gauge, 10 is a pressure adjustment valve, 11 is a dissolution discharge valve, 12 is a liquid seal discharge valve, 13 is a granulation discharge valve, 14 is a granulation tank sealing valve, 15 is a dissolution tank hot water shower line, 16 is a polymerization tank discharge valve, 17 is a liquid-sealed tank hot water shower line, and 18 is a liquid-sealed tank break valve.

  FIG. 2 is a schematic view of a preferred granulator used in the granulation step of the present invention. In FIG. 2, 21 is a stirring blade, 22 is a stirring chamber, and 23 is a stirring shaft.

  Hereinafter, a preferred embodiment of the production method of the present invention will be described with reference to FIGS. 1 and 2.

  First, a colorant composition containing at least a colorant is prepared in the dissolution tank 1. In the case of suspension polymerization, the medium constituting the colorant composition is preferably a polymerizable monomer. At this time, the temperature may be controlled using a jacket of a dissolution tank. Next, in the granulation tank 3, a liquid dispersion medium is produced. At this time, in order to adjust the liquid dispersion medium to an optimum temperature, the temperature may be adjusted using a jacket of a granulation tank, or the pH may be adjusted using an appropriate acid or alkali. . Further, the liquid dispersion medium is preferably produced while stirring using the granulation stirring device 4.

After preparation of the liquid dispersion medium, the colorant composition prepared from the dissolution tank 1 is charged into the granulation tank 3. After the colorant composition is charged, the shower water charged in the granulation tank 3 via the dissolution tank shower line 15 and the liquid seal tank shower line 17 is then supplied from the dissolution tank 1 and the liquid seal tank 5. The At this time, the shower water may be prepared in advance or may be shower water at room temperature. Moreover, it is preferable that the amount of shower water is charged so that the relationship between the granulation tank internal volume A and the granulation tank gas phase B after the shower water is charged satisfies the following formula (1).
0.05 ≧ B / A (1)

Furthermore, it is preferable that the gas layer ratio B / A is charged so as to satisfy the following formula (2).
0.01 ≧ B / A (2)

  By adjusting the gas phase part within this range, gas entrainment hardly occurs during granulation, and the shearing force generated by the granulation stirrer 4 can be efficiently applied to the colorant composition and the liquid dispersion medium.

  Furthermore, when adding shower water, it is preferable to stop the granulation stirrer 4 or to adjust the rotation speed so that no bubbles are entrained in order to suppress entrainment of bubbles from the free surface in the granulation tank. Thereafter, the granulation tank valve 14 and the liquid seal tank break valve are closed, and then the pressure adjustment valve is opened, and the air layer in the liquid seal tank 5 is pressurized with an inert gas or compressed air to a predetermined pressure. After a while, the liquid sealing tank 5 and the granulation tank 3 become the same pressure. When the same pressure is reached, granulation is started by adjusting the rotation speed of the granulation agitator 4 that has been stopped or adjusting the rotation speed to a predetermined rotation speed during granulation. Thus, by making the inside of the granulation tank 3 into a pressurized state, a rapid pressure fluctuation around the stirring blade 21 rotating at high speed can be suppressed. As a result, generation of bubbles due to cavitation can be prevented and the particle size distribution can be sharpened, and damage to the stirring blade due to cavitation erosion can be suppressed and the life of the apparatus can be extended.

  After granulation for a predetermined granulation time, the pressure granulation break valve 13 is gradually opened, the pressure of the pressure gauge 9 is brought close to normal pressure, and the liquid-sealed tank break valve 18 is opened to perform processing in the granulation tank. The product is sent to the polymerization tank 7. In this way, if the pressure release direction after pressurization is a post-process (polymerization process), it is possible to prevent the processed product in the granulation tank from going out of the system, which is preferable from the viewpoint of safety and work environment. . The processed product sent to the polymerization tank 7 is polymerized for a certain period of time while being stirred by the polymerization stirring device 8, and sent from the polymerization tank discharge valve 16 to the next step.

As described above, for sharpening the particle size distribution,
It is important that 1) the ratio of the air layer portion in the granulation tank 3 is 5% or less, and 2) the inside of the granulation tank 3 is in a pressurized state.

  In order to make the inside of the granulation tank 3 pressurized, the gas layer inside the liquid-sealed tank 5 communicating with the upper part of the granulation tank 3 is pressurized to a predetermined pressure by a method that should be called indirectly. It is preferable to maintain. This is because, compared with the case where the inside of the granulation tank 3 is directly pressurized, when the liquid-sealed tank 5 is indirectly pressurized, the air-layer portion of the liquid-air tank is caused by the temperature change and the processed material inside the granulation tank 3. This is because the pressurized state can be stably maintained because it acts as a cushion against pressure fluctuations due to gas generated by the gas.

Moreover, it is preferable that the absolute pressure C used for said pressurization is the range of the following Formula (3).
200 kPa ≦ C ≦ 900 kPa (3)

More preferably, the absolute pressure A to be pressurized is preferably in the range of the following formula (4).
290 kPa ≦ C ≦ 500 kPa (4)

  If the absolute pressure C is less than 200 kPa, the effect of suppressing cavitation does not work and the particle size distribution is not sharpened, which is not preferable.

  On the other hand, if the absolute pressure C is greater than 900 kPa, the tank thickness of the liquid sealing tank 5 and the granulation tank 3 increases, so that it is difficult to control the temperature inside the tank with a jacket or the like, and the manufacturing cost of the tank itself is reduced. Since it increases, it is not preferable.

Moreover, it is preferable that the circumferential speed of the stirring blade 21 is 17-40 m / s. More preferably, it is preferable that it is 25-35 m / s .

  If it is less than 17 m / s, the particle size distribution is broadened due to insufficient shearing force, which is not preferable.

  If it exceeds 40 m / s, the agitation motor is enlarged, and the manufacturing cost and running cost of the equipment increase, which is not preferable. Further, it is necessary to apply high pressure to suppress the generation of bubbles.

  Moreover, it is preferable that the liquid seal tank 5 communicates with the upper part of the granulation tank 3. Since the liquid seal tank 5 communicates with the upper part of the granulation tank 3, the gas layer inside the granulation tank 3 can be easily replaced with shower water or an aqueous medium. It can be in a non-existent state.

  Further, for example, it is preferable to provide a liquid seal tank break valve 18 in the upper part of the liquid seal tank and open the valve after pressurization release to provide pressure release or a gas flow path. If the valve is opened before the pressure is released, there is a risk that the processed material in the granulation tank is ejected from the valve, which is not preferable from the viewpoint of safety and work environment. Further, when the liquid sealing tank break valve 18 is opened after releasing the pressure to some extent, the speed of releasing the pressure increases, and after releasing the pressure completely, the processing in the granulation tank is performed in the subsequent process. This is preferable because it works as a gas flow path when sending an object.

  The agitation shaft of the granulation agitation device 4 is provided at the lower part of the agitation blade, and an angle θ (FIG. 1) formed by a straight axis formed by the agitation shaft and the central axis of the agitation blade and the vertical direction. Is preferably 45 ° or less. As an example in which θ is greater than 45 °, for example, when a stirring blade is provided at the tip of the stirring shaft extending from the top to the bottom of the granulation tank 3, the above-described stirring device having a high shearing force is used. Then, heat generation from the stirring device and the stirring shaft occurs due to high-speed stirring. This exothermic heat may affect the processed product (for example, polymerizable monomer composition) in the granulation tank 3 to cause a problem in desired dispersion. This problem of dispersion is not preferable because it causes a broadening of the particle size distribution of the obtained toner particles.

  Moreover, the said heat_generation | fever may superpose | polymerize the polymerizable monomer composition adhering to a stirring apparatus or a stirring shaft, and may produce a strong deposit | attachment. When this deposit grows, it may be mixed into the product or make the movable part of the stirring device immovable. The effect of this deposit can be avoided by periodically removing the deposit, but this periodic maintenance must be performed with the production line stopped, which increases the production cost. Therefore, it is not preferable.

  Examples of the granulation agitation measures 4 include, for example, Ultra Tarrax (manufactured by IKA), Polytron (manufactured by Kinematica), TK Auto Homomixer (manufactured by Special Machine Industries), National Cooking Mixer (manufactured by Matsushita Electric Industrial Co., Ltd.), A batch stirrer such as Clairemix (made by MTechnics) or fillmix (made by Tokushu Kika Kogyo Co., Ltd.) is preferably used, and particularly preferred is a bottom type Claremix (made by Mtechnics).

  Further, as the dissolution agitator 2, the liquid-sealed tank agitator 6, and the polymerization agitator 8, an apparatus capable of uniformly agitating the entire inside of the container is preferable. For example, paddle wing, three-bladed wing, anchor wing, more preferably full zone wing (manufactured by Shinko Pantech Co., Ltd.), max blend wing (manufactured by Sumitomo Heavy Industries, Ltd.), Sun Meller wing (manufactured by Mitsubishi Heavy Industries, Ltd.), Hi-F Examples include a mixer blade (manufactured by Soken Chemical Co., Ltd.), a bend leaf blade (manufactured by Hachiko Sangyo Co., Ltd.), and a resolver blade (manufactured by Mtechnic Co., Ltd.). 1 and 2 show a full zone wing.

  The method for producing toner particles of the present invention can also be preferably used for a method for producing magnetic toner particles. A magnetic material used in the production of magnetic toner particles will be described below.

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

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

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

  For example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyl Methyldiethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltri Methoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, n-butyltrimethoxysilane, iso Trimethoxysilane, trimethyl methoxysilane, hydroxypropyl trimethoxysilane, n- hexadecyl trimethoxy silane, can be mentioned n- octadecyl trimethoxysilane.

  Among these, in order to further improve the dispersibility of the magnetic substance, it is preferable to use a silane coupling agent having a double bond, such as phenyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyl. Trimethoxysilane is more preferred. This is thought to be due to the better compatibility between the magnetic substance and the polymerizable monomer, particularly when the suspension polymerization is performed with a coupling agent having a double bond. The dispersibility of the magnetic material is good.

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

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

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

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

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

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

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

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

  The magnetic material used in the toner of the present invention preferably uses 10 to 200 parts by mass with respect to 100 parts by mass of the binder resin. More preferably, 20 to 180 parts by mass are used. If it is less than 10 parts by mass, the coloring power of the toner is poor, and it is difficult to suppress fogging. On the other hand, when the amount exceeds 200 parts by mass, not only the retention force of the obtained toner due to the magnetic force on the toner carrier increases, but the developability decreases, and it is difficult not only to uniformly disperse the magnetic material to individual toner particles. , The fixing property is lowered.

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

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

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

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

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

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

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

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

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

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

  These colorants can be used singly or in combination of two or more, or can be used in the form of a solid solution. The colorant of the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. 1-20 mass parts is used for the addition amount of a coloring agent with respect to 100 mass parts of resin.

  The toner particles produced in the present invention may contain a release agent. As the release agent usable for the toner particles in the present invention, petroleum wax such as paraffin wax, microcrystalline wax, petrolactam and derivatives thereof, montan wax and derivatives thereof, hydrocarbon wax and derivatives thereof by Fischer-Tropsch method, Polyolefin waxes typified by polyethylene and derivatives thereof, natural waxes and derivatives thereof such as carnauba wax and candelilla wax, and the derivatives include oxides, block copolymers with vinyl monomers, and graft modified products. Furthermore, fatty acids such as higher aliphatic alcohols, stearic acid and palmitic acid, or compounds thereof, acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, plant waxes, animal waxes and the like can also be used.

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

  A charge control agent may be blended in the toner particles used in the present invention. A well-known thing can be utilized as a charge control agent. Further, when toner particles are produced using a direct polymerization method, a charge control agent having a low polymerization inhibitory property and substantially free from a solubilized product in an aqueous dispersion medium is particularly preferable. Specific compounds include, as negative charge control agents, metal compounds of aromatic carboxylic acids such as salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid, metal salts or metal complexes of azo dyes or azo pigments, sulfones Examples thereof include a polymer compound having an acid or carboxylic acid group in the side chain, a boron compound, a urea compound, a silicon compound, and a calixarene. Examples of the positive charge control agent include quaternary ammonium salts, polymer compounds having the quaternary ammonium salt in the side chain, guanidine compounds, nigrosine compounds, and imidazole compounds.

  As a method of adding a charge control agent to the toner, there are a method of adding it inside the toner particles and a method of adding it externally to the toner particles. The amount of these charge control agents used 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. When added internally, 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. 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.

  Examples of the polymerizable monomer contained in the toner produced in the present invention include the following.

  Examples of the polymerizable monomer include styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-ethylstyrene, methyl acrylate, ethyl acrylate, Acrylic esters such as n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, etc. , Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, Methacrylic acid dimethyl aminoethyl methacrylate esters such as diethylaminoethyl methacrylate and other acrylonitrile-methacrylonitrile-monomer acrylamide.

  In the method for producing the toner of the present invention, the polymerization may be performed by adding a resin to the polymerizable monomer. For example, it contains hydrophilic functional groups such as amino groups, carboxylic acid groups, hydroxyl groups, sulfonic acid groups, glycidyl groups, and nitrile groups that cannot be used because monomers are water-soluble and dissolve in aqueous suspension to cause emulsion polymerization. When it is desired to introduce the monomer component into the toner, a random copolymer of these and a vinyl compound such as styrene or ethylene, a block copolymer, a copolymer such as a graft copolymer, or a polyester It can be used in the form of a polycondensate such as polyamide or in the form of a polyaddition polymer such as polyether or polyimine.

  In the present invention, an alcohol component and an acid component constituting the polyester resin used by adding to the polymerizable monomer are exemplified below. As alcohol components, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexane Diol, neopentyl glycol, 2-ethyl-1,3-hexanediol, cyclohexanedimethanol, butenediol, octenediol, cyclohexenedimethanol, hydrogenated bisphenol A, a bisphenol derivative represented by formula (I) or the formula (I Hydrogenated product of the compound represented by

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

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

  Alternatively, a diol represented by the following formula (II) or a hydrogenated product of the compound represented by the formula (II) can be mentioned.

  Divalent carboxylic acids include benzene dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride or anhydrides thereof; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid, or anhydrides thereof; Furthermore, succinic acid substituted with an alkyl or alkenyl group having 6 to 18 carbon atoms or an anhydride thereof; unsaturated dicarboxylic acid such as fumaric acid, maleic acid, citraconic acid or itaconic acid, or an anhydride thereof.

  Furthermore, polyhydric alcohols such as glycerin, pentaerythritol, sorbit, sorbitan, and oxyalkylene ethers of novolac type phenol resins can be cited as the alcohol component, and trimellitic acid, pyromellitic acid, 1,2,3,4- Examples thereof include polyvalent carboxylic acids such as butanetetracarboxylic acid, benzophenonetetracarboxylic acid and anhydrides thereof.

  It is preferable that 45-55 mol% of the said polyester resin is an alcohol component, and 55-45 mol% is an acid component in all the components. In the present invention, two or more kinds of polyester resins may be used in combination as long as the physical properties of the obtained toner particles are not adversely affected, or modified with, for example, silicone or a fluoroalkyl group-containing compound to adjust the physical properties. Is also preferably performed. Moreover, when using the high molecular polymer containing such a polar functional group, the average molecular weight is preferably 5,000 or more.

  In addition, resins other than those mentioned above may be added to the monomer system. Examples of the resin used include styrene such as polystyrene and polyvinyltoluene, and homopolymers of substitution products thereof; styrene-propylene copolymer, styrene -Vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer Styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer Polymer, styrene-vinyl methyl ether copolymer, steel -Vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer, etc. Styrene copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic resin, rosin, modified rosin, terpene resin, Phenolic resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins and the like can be used alone or in combination.

  As addition amount of these resin, 1-20 mass parts is preferable with respect to 100 mass parts of monomers. If the amount is less than 1 part by mass, the effect of addition is small, while if it exceeds 20 parts by mass, it becomes difficult to design various physical properties of the polymerized toner.

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

  In the method for producing a toner of the present invention, a polymerization initiator used for initiating a polymerization reaction of a polymerizable monomer is a polymerization initiator having a half-life of 0.5 to 30 hours during the polymerization reaction. 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 polymer, a polymer having a maximum between 10,000 and 100,000 is obtained, and the desired strength and suitable melting characteristics for the toner are obtained. Can be given. Examples of polymerization initiators include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile) Azo or diazo polymerization initiators such as 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, Examples thereof include peroxide-based polymerization initiators such as cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, t-butylperoxy 2-ethylhexanoate, and t-butylperoxypivalate.

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

  Here, as the crosslinking agent, a compound having two or more polymerizable double bonds is mainly used, for example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene, etc .; for example, ethylene glycol diacrylate, ethylene glycol diester Carboxylic acid ester having two double bonds such as methacrylate, 1,3-butanediol dimethacrylate, etc .; Divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone, etc .; and having three or more vinyl groups Are used alone or as a mixture of two or more.

  A specific toner production method of the present invention is a colorant-containing polymerizable monomer composition obtained in the above-described dissolution step, that is, a pigment, a release agent, a plasticizer, and a charge control agent in the polymerizable monomer. , Components necessary for the toner such as a crosslinking agent and other additives, for example, an organic solvent, a high molecular weight polymer, a dispersing agent, etc., which are added to reduce the viscosity of the polymer produced by the polymerization reaction, are appropriately added and dissolved uniformly. Alternatively, the dispersed monomer system is suspended and granulated in an aqueous medium containing a dispersion stabilizer under pressure while maintaining a state where the gas layer part is not substantially present.

  Thus, after granulating a colorant containing polymerizable monomer composition, or after granulating, a polymerization initiator is added and the said composition is superposed | polymerized (polymerization process). The polymerization initiator may be added at the same time when other additives are added to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. Moreover, a polymerization initiator dissolved in an additional polymerizable monomer or solvent during the polymerization reaction can be added immediately after granulation and before starting the polymerization reaction.

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

  When the toner of the present invention is produced, a known surfactant or organic / inorganic dispersant can be used as a dispersion stabilizer. Among them, inorganic dispersants are unlikely to produce harmful ultrafine powders, and because of their steric hindrance, dispersion stability is obtained, so even if the reaction temperature is changed, stability is not easily lost, and cleaning is easy and does not adversely affect the toner. It can be preferably used. Examples of such inorganic dispersants include polyvalent metal phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate; carbonates such as calcium carbonate and magnesium carbonate; calcium metasuccinate, calcium sulfate and barium sulfate. Inorganic salts; inorganic hydroxides such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide; inorganic oxides such as silica, bentonite, and alumina.

  These inorganic dispersants are desirably used alone in an amount of 0.2 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer, but 0.001 to 0.1 parts by mass of a surfactant is added. You may use together.

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

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

  In the polymerization step, the polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. When the polymerization is carried out in this temperature range, the release agent or wax to be sealed inside is precipitated by phase separation, and the encapsulation becomes more complete. Further, in order to consume the remaining polymerizable monomer, the reaction temperature can be raised to 90 to 150 ° C. at the end of the polymerization reaction.

  After completion of the polymerization reaction, the obtained polymer particles are filtered, washed and dried by a known method. In general, toner particles obtained by removing coarse powder and fine powder out of a desired particle size range in the classification process are obtained. The classification step can be carried out by a known method used in conventional toner production, and is not particularly limited. A toner can be obtained by mixing an external additive such as an inorganic fine powder with the toner particles obtained through the classification step and adhering them to the surface of the toner particles. In the present invention, it is one of desirable forms to omit the classification process from the manufacturing process and directly obtain the toner, or to further perform the classification process to cut coarse powder and fine powder with high accuracy.

  In the present invention, it is also a preferred embodiment that an inorganic fine powder having a number average primary particle size of 4 to 80 nm is added to the toner as a fluidizing agent among the external additives.

Silica, alumina, titanium oxide, etc. can be used as the inorganic fine particles used in the present invention. For example, as the silicic acid fine powder, both a so-called dry method produced by vapor phase oxidation of silicon halide or dry silica called fumed silica, and so-called wet silica produced from water glass or the like can be used. is there. Preferred are less silanol groups on the inner surface and the fine silica powder and is towards the Na ₂ O, less dry silica of manufacture residues of SO ^3- and the like. In dry silica, it is also possible to obtain composite fine powders of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the production process, They are also included.

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

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

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

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

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

  As a method for treating silicone oil, for example, silica treated with a silane compound and silicone oil may be directly mixed using a mixer such as a Henschel mixer, or a method of spraying silicone oil on silica may be used. Also good. Alternatively, after dissolving or dispersing silicone oil in an appropriate solvent, a method may be used in which fine silica powder is added and mixed to remove the solvent. A method using a sprayer is more preferable in that the formation of inorganic fine particle aggregates is relatively small.

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

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

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

In addition, the toner of the present invention is a toner having, as an external additive, inorganic or organic spherical fine particles having a primary particle size of more than 30 nm, more preferably 50 nm or more, for the purpose of improving cleaning properties. It is one of the preferable forms to be added to the particles. As the inorganic or organic fine particles, those having a specific surface area of less than 50 m ² / g (more preferably a specific surface area of less than 30 m ² / g) can be preferably used. As such fine particles, for example, spherical silica particles, spherical polymethylsilsesquioxane particles, spherical resin particles and the like are preferably used.

  In the toner used in the present invention, other external additives can be further added to the toner particles within a range that does not substantially adversely affect the toner. For example, lubricant powder such as polyfluorinated ethylene powder, zinc stearate powder, polyvinylidene fluoride powder; abrasive such as cerium oxide powder, silicon carbide powder, strontium titanate powder; imparting fluidity such as titanium oxide powder, aluminum oxide powder Agents; anti-caking agents and the like. In addition, a small amount of organic fine particles or inorganic fine particles having a reverse polarity can be used as a developability improver. These external additives can also be used after the surface is hydrophobized.

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

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

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

  The substance adhering to the carrier particle surface varies depending on the toner material. For example, polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, styrene resin, acrylic resin, polyamide, polyvinyl butyral And aminoacrylate resins. These may be used alone or in plural.

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

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

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

(1) Measurement of toner particle size distribution and calculation of number variation coefficient The toner particle size distribution can be measured by various methods. In the present invention, it is preferable to use a Coulter counter.

  Using Coulter Counter Multisizer Type I or Type II or Type IIe (manufactured by Coulter, Inc.) as a measuring device, connect an interface (manufactured by Nikkiki) that outputs number average distribution and volume average distribution and a general personal computer. A 1% NaCl aqueous solution is prepared as an electrolyte using special grade or first grade sodium chloride.

  As a measuring method, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolyte in which the sample is suspended is subjected to a dispersion process for about 1 to 3 minutes with an ultrasonic disperser, and by using the Coulter Counter Multisizer II, a 100 μm aperture is used as an aperture, and particles having a size of 2 to 40 μm on the basis of the number are used. The particle size distribution is measured, and various values are obtained therefrom.

The coefficient of variation in the number distribution is calculated from the following equation.
Coefficient of variation (%) = [S / D1] × 100 (5)
[In the formula, S represents a standard deviation in the number distribution of toner particles, and D1 represents a number average diameter (μm) of toner particles. ]

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but these do not limit the present invention in any way.

<Example 1>
An aqueous dispersion medium and a colorant composition were prepared using the dissolution tank 1 and the granulation tank 3 shown in FIG.

  Further, the total amount of the dispersion medium and the toner component shown below is calculated in advance so as to be 90% of the internal volume of the granulation tank.

(Preparation of aqueous dispersion medium)
In a granulation tank 3 equipped with a high-speed stirrer bottom type clear mix 4 (θ = 30 °), the following components are mixed and heated to 60 ° C. Stir at a speed of 35 m / s.
・ Ion-exchanged water 950 parts by mass ・ 0.1 mol / liter-Na ₃ PO ₄ aqueous solution 450 parts by mass

Next, the inside of the granulation tank was purged with nitrogen, and 68 parts by mass of a 1.0 mol / liter CaCl ₂ aqueous solution was added and reacted to obtain an aqueous dispersion medium containing fine particles of calcium phosphate.

Next, after adding a coloring agent dispersion in which 10 parts by mass of a coloring agent (CI Pigment Red 150) to 110 parts by mass of styrene is finely dispersed in advance into a dissolution tank having a full zone blade, the following components are added. Added.

-35 parts by weight of n-butyl acrylate-2 parts by weight of E-88 (manufactured by Orient Chemical Co., Ltd.)-Terephthalic acid-propylene oxide modified bisphenol A (acid value 10 mg KOH / g, molecular weight 7500)
10 parts by mass, 0.3 parts by mass of divinylbenzene, ester wax (maximum value of endothermic peak in DSC 72 ° C.) After adding 25 parts by mass, the temperature of the full zone blade is increased to 60 ° C. over 30 minutes, and the peripheral speed of the full zone blade is 5 m / s Then, stirring of the stirring blade was started. The operation was continued after the temperature of the treated product reached 60 ° C., and after 60 minutes, a colorant composition was obtained.

(Granulation process and polymerization process)
After changing the peripheral speed of the high-speed agitator bottom type CLEARMIX 4 to 15 m / s, the full zone in the dissolution tank is stopped, the dissolution discharge valve 11 and the granulation tank valve 14 are opened, and the calcium phosphate in the granulation tank 3 is opened. The obtained colorant composition was put into an aqueous dispersion medium containing fine particles of salt. After the charging, a predetermined amount of shower water was charged from the dissolution tank shower line 15. After adding shower water, the granulation tank valve 14 was closed.

Next, the liquid seal discharge valve 12 and the liquid seal tank pressure release valve 18 are opened, and 6 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) prepared in the liquid seal tank 5 in advance. Was added a polymerization initiator solution in which 20 parts by mass of styrene was dissolved. After discharging the initiator solution, the liquid seal tank shower line 17 was opened, and hot water at 60 ° C. was supplied to the granulation tank 3. Shower water from the liquid seal tank shower lines, granulation tank vapor layer portion ratio at this point, with respect to the granulation tank volume is preset to such conditions of 1%.

Thereafter, after closing the liquid seal tank pressure release valve 18, the pressure adjustment valve 10 was opened and nitrogen was supplied into the liquid seal tank to pressurize the liquid seal tank 5 to an absolute pressure of 290 kPa.

  After pressurizing the inside of the liquid-sealed tank 5, the peripheral speed of the granulating and stirring device 4 (the high-speed stirring device bottom type CLEARMIX) was changed to 35 m / s, and granulation was performed for 30 minutes. The absolute pressure inside the liquid ring tank 5 immediately before the end of the granulation time was 300 kPa. It is thought that the pressure increased due to the generated gas accompanying the decomposition of the polymerization initiator charged in advance.

  After completion of the granulation time, the pressure granulation pressure release valve 13 was gradually opened to start the transfer of the processed material into the polymerization tank 7 equipped with a full zone stirring blade while releasing the pressure in the granulation tank. When the pressure in the granulation tank reached normal pressure, the liquid seal tank pressure release valve 18 was opened and the entire amount of the processed product was transferred into the polymerization tank 7. By this transfer method, it was possible to transfer safely and without impairing the working atmosphere. After the transfer, polymerization was carried out at an internal temperature of 60 ° C. while stirring the full zone blade in the polymerization tank 7 at 5 m / s. After 6 hours, the polymerization temperature was raised to 80 ° C., and stirring was continued for 3 hours to complete the polymerization. After completion of the polymerization, a small amount of the slurry was sampled, the particle size distribution was measured, the number variation coefficient was calculated, and evaluated according to the following evaluation criteria. This number variation coefficient indicates that the smaller the value, the sharper the particle size distribution.

[Evaluation criteria for number variation coefficient]
A: Less than 22.0% B: 22.0% or more and less than 24.0% C: 24.0% or more and less than 26.0% D: 26.0% or more

  The obtained volume-based weight average particle diameter D4 and the number variation coefficient evaluation results are shown in Table 1.

  After completion of the polymerization reaction, the residual monomer was distilled off under reduced pressure. After cooling, diluted hydrochloric acid was added to dissolve the dispersant, and solid-liquid separation, water washing, filtration, drying, and classification were performed to obtain polymerized toner particles.

100 parts by mass of the obtained magenta toner particles and 1.5 parts by mass of hydrophobic titanium oxide fine powder having a specific surface area of 100 m ² / g by BET method were mixed to obtain a magenta toner having negative triboelectric charging properties.

(Evaluation)
A two-component developer is prepared by mixing 95 parts by mass of an acrylic-coated ferrite carrier with 5 parts by mass of this magenta toner, and using a commercially available digital full-color copying machine (CLC500, manufactured by Canon Inc.) I went out. After the completion of image output, the image density was measured. The image density formed a solid image portion, and this solid image was measured with a Macbeth reflection densitometer (manufactured by Macbeth Co.) and evaluated according to the following evaluation criteria. After printing out 5000 images with a printing rate of 2% in an environment of normal temperature and humidity (23 ° C./50%), a solid image was output. The results are shown in Table 1.

[Evaluation criteria for image density]
A: 1.4 or more B: Less than 1.4 1.2 or more C: Less than 1.2 1.0 or more D: Less than 1.0

  Further, these operations were repeated 40 times and continuous operation was carried out. However, no deposits were observed on the granulation stirrer 4 in the granulation tank 3, and stable toner particles could be produced throughout.

<Example 2>
Except that the absolute pressure during granulation in Example 1 was changed to 500 kPa, the same operations as in Example 1 were performed to obtain toner particles and a two-component developer, and image evaluation was performed. The absolute pressure inside the liquid ring tank 5 immediately before the end of the granulation time was 505 kPa. The results are shown in Table 1.

<Example 3>
High-speed agitator during granulation of Example 1 Except for changing the peripheral speed of the CLEARMIX 4 to 25 m / s, the same operation as in Example 1 was performed to obtain toner particles and a two-component developer, and image evaluation Went. The results are shown in Table 1.

<Example 4>
High-speed stirrer at the time of granulation of Example 1 The toner particles and the two-component developer were obtained by performing the same operation as in Example 1 except that the peripheral speed of the CLEARMIX 4 was changed to 40 m / s, and image evaluation Went. The results are shown in Table 1.

<Example 5>
High-speed stirrer at the time of granulation in Example 1 The toner particles and the two-component developer were obtained by performing the same operation as in Example 1 except that the peripheral speed of the CLEARMIX 4 was changed to 17 m / s, and image evaluation Went. The results are shown in Table 1.

<Example 6>
Example 1 except that the granulation tank 3 gas layer portion ratio is 5% with respect to the inner volume of the granulation tank 3 from the lower part of the granulation tank valve 15 toward the inside of the granulation tank 3. The toner particles and the two-component developer were obtained by performing the same operation as in Example 1, and image evaluation was performed. The results are shown in Table 1.

<Example 7>
Except that the absolute pressure during granulation in Example 1 was changed to 200 kPa, the same operation as in Example 1 was performed to obtain toner particles and a two-component developer, and image evaluation was performed. The absolute pressure inside the liquid ring tank 5 immediately before the end of the granulation time was 220 kPa. The results are shown in Table 1.

<Example 8>
Except that the absolute pressure during granulation in Example 1 was changed to 850 kPa, the same operation as in Example 1 was performed to obtain toner particles and a two-component developer, and image evaluation was performed. The absolute pressure inside the liquid ring tank 5 immediately before the end of the granulation time was 853 kPa. The results are shown in Table 1.

<Example 9>
Except for extending the granulation time to 40 minutes, the same operation as in Example 1 was performed to obtain toner particles and a two-component developer, and image evaluation was performed. The absolute pressure inside the liquid seal tank 5 immediately before the end of the granulation time was 310 kPa. The results are shown in Table 1.

<Example 10>
Except for reducing the granulation time to 15 minutes, the same operations as in Example 1 were performed to obtain toner particles and a two-component developer, and image evaluation was performed. The absolute pressure inside the liquid ring tank 5 immediately before the end of the granulation time was 290 kPa. The results are shown in Table 1.

<Example 11>
A toner was obtained and evaluated in the same manner as in Example 1 except that θ = 45 °. The results are shown in Table 1.

<Example 12>
A surface-treated magnetic material was prepared by the following method.

  In ferrous sulfate aqueous solution, l. 0 to 1.1 equivalent of caustic soda solution, 0.95 mass% sodium hexametaphosphate in terms of phosphorus element with respect to iron element, 0.95 mass% sodium silicate in terms of silicon element with respect to iron element, An aqueous solution containing ferrous iron was prepared.

  While maintaining the pH of the aqueous solution at around 13, air was blown and an oxidation reaction was performed at 80 to 90 ° C. to obtain a slurry solution of magnetic particles. After washing and filtering, this hydrous slurry liquid was once taken out. At this time, a small amount of water-containing sample was collected and the water content was measured. Next, this water-containing sample was re-dispersed in another aqueous medium without drying, and then the pH of the dispersion was adjusted to about 6, and the n-hexyltrimethoxysilane coupling agent was added to the magnetic particles while stirring sufficiently. 1.9 parts by mass with respect to 100 parts by mass, 1.1 parts by mass of γ-methacryloxypropyltrimethoxysilane coupling agent (the amount of magnetic particles was calculated as a value obtained by subtracting the water content from the water-containing sample), A coupling treatment was performed. The produced hydrophobic magnetic particles are washed, filtered and dried, and the obtained hydrophobic magnetic particles are sufficiently pulverized to have a number average particle diameter of 0.13 μm and a number average variation coefficient of 8 surface treated magnetic body Got.

  Using the dissolution tank 1 and the granulation tank 3 shown in FIG. 1, an aqueous dispersion medium and the surface-treated magnetic substance-containing colorant composition were prepared.

  Further, the total amount of the dispersion medium and the toner component shown below is calculated in advance so as to be 90% of the internal volume of the granulation tank.

(Preparation of aqueous dispersion medium)
In the granulation tank 3 equipped with the high-speed stirrer bottom type Claremix 4, the following components are mixed, heated to 60 ° C., and then stirred at a peripheral speed of 35 m / s of the high-speed stirrer bottom type Claremix 4 did.
Ion-exchanged water 720 parts by weight 0.1 mol / liter -Na ₃ PO ₄ aqueous solution 450 parts by mass Next, the granulation tank with nitrogen replacement, CaCl ₂ aqueous solution 68 parts by mass of this 1.0 mol / liter An aqueous dispersion medium containing fine particles of calcium phosphate was obtained. Next, after adding the surface-treated magnetic material-containing colorant dispersion in which 85 parts by mass of the surface-treated magnetic material is finely dispersed in 78 parts by mass of styrene into a dissolution tank having a full zone blade as a stirring blade, the following components are added. did.
-N-butyl acrylate 22 parts by mass-terephthalic acid-propylene oxide modified bisphenol A (acid value 10 mg KOH / g, molecular weight 7500) 1 part by mass-divinylbenzene 0.20 parts by mass-ester wax (maximum endothermic peak in DSC 72 7 parts by mass / negative charge control agent (monoazo dye-based Fe compound) After adding 1 part by mass, stirring of the stirring blade was started at 5 m / s while the temperature was raised to 60 ° C. over 30 minutes. The operation was continued after the temperature of the treated product reached 60 ° C., and after 60 minutes, a colorant composition was obtained.

(Granulation process and polymerization process)
After changing the peripheral speed of the high-speed agitator bottom type CLEARMIX 4 to 15 m / s, the full zone in the dissolution tank is stopped, the dissolution discharge valve 11 and the granulation tank valve 14 are opened, and the calcium phosphate in the granulation tank 3 is opened. The obtained surface-treated magnetic substance-containing colorant composition was put into an aqueous dispersion medium containing salt fine particles. After the charging, a predetermined amount of shower water was charged from the dissolution tank shower line 15. After adding shower water, the granulation tank valve 14 was closed.

Next, the liquid seal discharge valve 12 and the liquid seal tank pressure release valve 18 were opened, and 3 parts by mass of t-butyl peroxypivalate was charged as a polymerization initiator. After discharging the initiator, the liquid sealed tank shower line 17 was opened, and hot water of 60 ° C. was supplied to the granulation tank 3. The shower water from the liquid-sealed tank shower line is set in advance so that the granulation tank gas layer ratio at this time is 1% with respect to the granulation tank internal volume. afterwards,
After closing the liquid ring tank pressure release valve 18, the pressure adjustment valve 10 was opened and nitrogen was supplied into the liquid ring tank to pressurize the liquid ring tank 5 to an absolute pressure of 290 kPa.

  After pressurizing the inside of the liquid-sealed tank 5, the peripheral speed of the granulating and stirring device 4 (the high-speed stirring device bottom type CLEARMIX) was changed to 35 m / s, and granulation was performed for 30 minutes. The absolute pressure inside the liquid ring tank 5 immediately before the end of the granulation time was 295 kPa. It is thought that the pressure increased due to the generated gas accompanying the decomposition of the polymerization initiator charged in advance.

  After completion of the granulation time, the pressure granulation pressure release valve 13 was gradually opened to start the transfer of the processed material into the polymerization tank 7 equipped with a full zone stirring blade while releasing the pressure in the granulation tank. When the pressure in the granulation tank reached normal pressure, the liquid seal tank pressure release valve 18 was opened and the entire amount of the processed product was transferred into the polymerization tank 7. By this transfer method, it was possible to transfer safely and without impairing the working atmosphere. After the transfer, the polymerization temperature was immediately raised to 70 ° C. while stirring the full zone blade in the polymerization tank 7 at a peripheral speed of 5 m / s, and after the temperature increase, stirring was continued for 6 hours to complete the polymerization. After completion of the polymerization, a small amount of the slurry was sampled, the particle size distribution was measured, the number variation coefficient was calculated, and evaluated according to the evaluation criteria shown in Example 1.

  The obtained volume-based weight average particle diameter D4 and the number variation coefficient evaluation results are shown in Table 1.

  After completion of the polymerization reaction, the residual monomer was distilled off under reduced pressure. After cooling, diluted hydrochloric acid was added to dissolve the dispersant, and solid-liquid separation, water washing, filtration, drying, and classification were performed to obtain magnetic toner particles.

The obtained magnetic toner particles 100 parts by mass and a silica fine powder (BET specific surface area 180 m ² / g) having a number average primary particle size of 12 nm were treated with hexamethyldisilazane and then treated with silicone oil, and the treated BET 1.0 part by mass of hydrophobic silica fine powder (number average primary particle size 12 nm) having a value of 120 m ² / g was mixed with a Henschel mixer (Mitsui Mining Co., Ltd.) to obtain a magnetic toner.

  Using this magnetic toner, evaluation was performed using Canon LBP-1760 as an image forming apparatus. Evaluation criteria were evaluated according to the criteria shown in Example 1. The evaluation results are shown in Table 1.

  Further, these operations were repeated 40 times and continuous operation was carried out. However, no deposits were observed on the granulation stirrer 4 in the granulation tank 3, and stable toner particles could be produced throughout.

<Reference Example 1>
The granulation time was completed in the same manner as in Example 1. Thereafter, it was attempted to gradually open the liquid sealing tank pressure release valve 18 to release the pressure in the granulation tank, but the processed material in the granulation tank 3 was released from the open end of the liquid sealing tank pressure release valve 18. Overflowed. The overflowing capacity reached 20% of the 3 volumes of the granulation tank. After the pressure in the granulation tank 3 reached normal pressure, the pressurized granulation pressure release valve 13 was opened, and the transfer of the processed material into the polymerization tank 7 equipped with a full zone stirring blade was started. This transfer method is not a safe transfer because it not only impairs the working atmosphere but also a risk of being exposed to overflowing processed materials. After the transfer, polymerization was performed at an internal temperature of 60 ° C. while stirring the full zone blade in the polymerization tank 7 at a peripheral speed of 5 m / s. Thereafter, a toner was obtained and evaluated in the same manner as in Example 1. The results are shown in Table 1.

<Reference Example 2>
Toner particles were obtained in the same manner as in Example 1 except that the granulating and agitating device 4 used the top type CLEARMIX shown in FIG. In this granulation agitation device, the agitation drive device is provided above the granulation tank 3, and the granulation agitation device 4 is provided near the bottom of the granulation tank 3 and above the pressure granulation pressure release valve 13. The stirring shaft 23 penetrates the liquid level in the granulation tank 3 to connect the stirring driving device and the granulation stirring device 4, and the stirring chamber 22 is directed toward the tip of the stirring shaft 23 in a direction in which the sectional area gradually decreases. The configuration is the same as that of the granulation agitation apparatus 4 shown in FIG. The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 1.

  Although these operations were repeated for continuous operation, the particle size distribution was adversely affected from around 30 times, and the particle size distribution was clearly broadened at the 40th time. This is presumed to be an adverse effect on the particle size distribution due to the thermal influence on the polymerizable monomer due to the heat generation of the stirring shaft 23 and the contamination of the deposits on the stirring shaft 23.

<Comparative Example 1>
Granulation was performed from the lower part of the granulation tank valve 14 toward the inside of the granulation tank 3 under the condition that the ratio of the gas layer portion of the granulation tank 3 to 7% of the volume of the granulation tank. Further, the liquid sealing tank was not pressurized during granulation. Except for the above, the same operations as in Example 1 were performed to obtain toner particles and a two-component developer, and image evaluation was performed. The results are shown in Table 1.

It is a figure which shows an example of the flow which shows the whole flow of the manufacturing method of this invention. It is typical sectional drawing which shows an example of the granulation apparatus which can be used suitably for the manufacturing method of this invention. It is an example figure which shows the structure of a top type granulation stirring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dissolution tank 2 Dissolution stirrer 3 Granulation tank 4 Granulation stirrer 5 Liquid seal tank 6 Liquid seal tank agitator 7 Polymerization tank 8 Polymerization stirrer 9 Pressure gauge 10 Pressure adjustment valve 11 Dissolution discharge valve 12 Liquid seal discharge valve 13 Pressure granulation pressure release valve 14 Granulation tank valve 15 Dissolution tank shower line 16 Polymerization tank discharge valve 17 Liquid seal tank shower line 18 Liquid seal tank pressure release valve 21 Stir blade 22 Stir chamber 23 Stir shaft

Claims (4)

Granulation step of generating particles of at least a colorant and a polymerizable monomer containing a colorant composition colorant composition in the aqueous medium in the granulation tank, the polymerization in communication with said granulation tank polymerization process, the production method of the toner particles comprising at least a rear cormorants line post-processing of the obtained toner particles step of polymerizing the polymerizable monomer in the particles of the coloring composition in the tank to generate the toner particles In
The colorant composition is granulated in an aqueous medium using an apparatus comprising a granulation tank and a stirrer to produce the particles of the colorant composition;
The stirring device includes a stirring blade that rotates at high speed, a stirring shaft, and a stirring chamber, and the peripheral speed of the stirring blade is 17 to 40 m / s.
When the internal volume of the granulation tank is A and the volume of the gas layer inside the granulation tank is B, the gas layer ratio B / A is expressed by the following formula (1)
0.05 ≧ B / A (1)
Satisfied,
A liquid ring tank communicating with the upper direction of the granulation tank is provided, shower water or an aqueous medium in the liquid ring tank is introduced into the granulation tank, and a gas phase part of the liquid ring tank is pressurized, Pressurizing the communicating granulation tank;
The method for producing toner particles, wherein the granulation step in the granulation tank is performed under pressure, and the release direction of the pressurization is a direction of the polymerization tank positioned below the granulation tank. . The method for producing toner particles according to claim 1, wherein the pressure is such that the absolute pressure C satisfies the following formula (2).
200 kPa ≦ C ≦ 900 kPa (2) After pressing open the opening direction, the production method of the toner particles according to claim 1 or 2, characterized by providing a flow path for pressurized open or gas in the other direction. The stirring shaft is provided at a lower portion of the stirring blade, and an angle θ formed by a straight axis formed by the stirring shaft and a central axis of the stirring blade and a vertical direction is 45 ° or less. method for producing toner particles according to any one of claims 1 to 3.

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