JP2010282198A - Method for producing developer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively produce a developer by using a high-pressure homogenizer. <P>SOLUTION: The method for producing the developer includes steps of: preparing a toner material dispersion liquid comprising a granulated toner material containing a binder resin, and an aqueous medium; and subjecting the dispersion liquid to mechanical shearing by passing the dispersion liquid through a high-pressure homogenizer so as to further finely granulate the granulated toner material to form fine particles. In the method, a check valve having an impact imparting part is provided in a pressurizing unit of the high-pressure homogenizer, and thereby, mechanical shearing is carried out while preventing the check valve from clogging by adding an impact to the check valve from the impact imparting part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present embodiment relates to a method for producing a developer for developing an electrostatic charge image and a magnetic latent image in electrophotography, electrostatic printing, magnetic recording, and the like.

  In electrophotography, an electric latent image is formed on an image carrier, and then the latent image is developed with toner. After the toner image is transferred to a transfer material such as paper, it is fixed by means such as heating and pressing. To do. The toner to be used is not only a conventional single color black, but also forms an image using a plurality of colors of toner in order to form a full color image.

  The toner includes a two-component developer used by mixing with carrier particles and a one-component developer used as a magnetic toner or a nonmagnetic toner. These toners are usually produced by a kneading and pulverizing method. This kneading and pulverizing method is a method in which a release agent such as a binder resin, pigment and wax, a charge control agent and the like are melt-kneaded, and after cooling, coarsely pulverized and finely pulverized, and classified to produce desired toner particles. is there. Depending on the purpose, inorganic and / or organic fine particles are added to the surface of the toner particles produced by the kneading and pulverization method to obtain a toner.

  In the case of toner particles produced by a kneading and pulverizing method, the shape thereof is usually indeterminate and the surface composition thereof is not uniform. Although the shape and surface composition of the toner particles vary slightly depending on the pulverization properties of the materials used and the conditions of the pulverization process, it is difficult to intentionally control the shape.

  In particular, when a material with high pulverization properties is used, it is further pulverized or changed in shape due to various stresses in the developing machine. As a result, in the two-component developer, the pulverized toner is Adhering to the surface of the carrier accelerates the charging deterioration of the developer, and in the case of a one-component developer, the particle size distribution expands, the finely divided toner scatters, and the developability decreases with changes in the toner shape. However, there has been a problem that the image quality deteriorates.

  Further, when the toner contains a release agent such as wax, pulverization is likely to occur at the interface between the binder resin and the release agent, so that the release agent may be exposed on the surface of the toner. In particular, in the case of a toner composed of a highly elastic resin that is not easily pulverized and a brittle wax such as polyethylene, polyethylene is often exposed on the surface of the toner. Although such toner is advantageous for releasability at the time of fixing and cleaning of untransferred toner from the photoreceptor, the toner on the surface of the toner is subjected to mechanical force such as shearing force in the developing machine. And can be easily transferred to a developing roll, an image carrier, a carrier, and the like. For this reason, the developing roll, the image carrier, the carrier, and the like are easily contaminated by wax, and the reliability as a developer may be lowered.

  Under such circumstances, in recent years, an emulsion polymerization aggregation method has been proposed as a method for producing toner in which the shape and surface composition of toner particles are intentionally controlled.

  In the emulsion polymerization aggregation method, a resin dispersion is prepared by emulsion polymerization, while a colorant dispersion in which a colorant is dispersed in a solvent is prepared and mixed to form aggregated particles corresponding to the toner particle size. Thereafter, the toner particles are obtained by fusing to obtain toner particles. According to this emulsion polymerization aggregation method, the toner shape can be arbitrarily controlled from an indeterminate shape to a spherical shape by selecting the heating temperature condition.

  In the emulsion polymerization aggregation method, it can be obtained by aggregating and fusing at least a dispersion of resin fine particles and a dispersion of a colorant under predetermined conditions. However, the emulsion polymerization aggregation method has restrictions on the types of resins that can be synthesized and is suitable for the production of styrene-acrylic copolymers, but it is necessary to apply polyester resins that are known to have good fixability. I can't.

  On the other hand, there is a phase inversion emulsification method in which a pigment dispersion or the like is added to a solution dissolved in an organic solvent and water is added to the solution dissolved in an organic solvent as a method for producing a toner using a polyester resin, but the organic solvent is removed and recovered. There is a need. There has been proposed a method for producing fine particles by mechanical stirring in an aqueous medium without using an organic solvent. However, it is necessary to supply molten resin or the like to the stirring device, and handling is difficult. Further, the degree of freedom in shape control is low, and the toner shape cannot be arbitrarily controlled from an indeterminate shape to a spherical shape.

There is a manufacturing method proposed as a method for improving the above problems. In this production method, toner component materials are melt-kneaded or mixed, then heated to a molten state, and mechanically pulverized and agglomerated to create toner. This production method can provide a method for producing a developer that can reduce the particle size and control the shape without using an organic solvent, has little variation in surface composition, and has good fixability and image quality. It is.

  As this mechanical atomization method, a high-pressure wet atomizer such as a high-pressure homogenizer is excellent. The high-pressure homogenizer has a very strong shearing force, and can easily emulsify the toner component particles on the order of submicron and with a small amount of a surfactant.

  In addition, when toner particles are produced by uniformly agglomerating the fine particles, a small-diameter toner having a uniform composition can be produced. Therefore, in addition to the expectation of high image quality and low CPC, polyester having excellent fixing properties can be obtained. Since it can be used, energy saving can be expected.

  In this production method, the atomization of the polyester resin is achieved by heating to a temperature higher than the Tg of the resin, adjusting the pH to alkali, and providing shearing force while neutralizing the carboxyl group at the end of the polyester resin. From the viewpoint of preventing hydrolysis, a high-pressure homogenizer that can instantaneously provide a shearing force is preferably used as the atomizer.

However, when the kneaded material is atomized using a high-pressure homogenizer, the check valve, which is essential for applying high pressure to the pores that generate shear force, is likely to clog. There was a drawback that the processing became unstable.
In the check valve section, for example, particles with one or more coarse particles per gram that do not pass through a sieve with an opening of 300 μm are easily clogged by the check valve and cannot be stably atomized. It was. Occurrence of clogging is improved by pulverization so that coarse particles are completely eliminated by a pulverizer or the like, but a great amount of energy is consumed for pulverization, and productivity is deteriorated. In addition, particles finely pulverized to 20 μm or less have poor wettability and are difficult to disperse in water.

JP 60-225170 A JP-A-63-282749 JP-A-6-282099 JP-A-9-311502 JP 2007-323071 A

  An object of the present invention is to produce a developer at a low cost using a high-pressure homogenizer.

According to the embodiment, a step of preparing a toner material dispersion containing at least a binder resin containing a granulated toner material and an aqueous medium, and a pressurizing unit including a check valve provided with an impact applying unit The dispersion liquid is passed through a high-pressure homogenizer including a heating section, a nozzle section, and a cooling section, and the check valve is impacted from the impact applying section to prevent clogging of the check valve. The developer is subjected to mechanical shearing to finely granulate the granular toner material to form fine particles.

It is a flowchart showing the manufacturing method of the developer concerning an embodiment. It is the schematic showing an example of the non-return valve mounted in a high pressure type homogenizer. It is the schematic showing an example of the high voltage | pressure homogenizer structure which can be used for embodiment.

A method for producing a developer according to an embodiment includes a step of preparing a toner material dispersion containing a granulated toner material containing at least a binder resin and an aqueous medium, and a pressure unit, a heating unit, and a nozzle unit In addition, the dispersion is passed through a high-pressure homogenizer including a cooling unit, the dispersion is subjected to mechanical shearing, the granular toner material is further refined, and fine particles having a particle size smaller than the particle size of the granular toner material are obtained. A check valve including an impact applying portion is provided in the pressurizing portion including a forming step, and mechanical shearing is performed while preventing the check valve from being clogged by applying an impact to the check valve from the impact applying portion. I can do it.

  Hereinafter, embodiments will be described with reference to the drawings.

  FIG. 1 shows a flow representing a developer manufacturing method according to the embodiment.

  As shown in the figure, first, a granulated toner material containing at least a binder resin is prepared. Next, a toner material dispersion containing the granulated toner material and an aqueous medium is prepared (Act 1).

  Thereafter, the toner material dispersion is passed through a high-pressure homogenizer including a pressurizing unit, a heating unit, a nozzle unit, and a cooling unit having a check valve provided with an impact applying unit, and then subjected to mechanical shearing. Are finely granulated to form fine particles (Act 2). At this time, mechanical shearing is performed while applying an impact to the check valve from the impact applying portion to prevent the check valve from being clogged.

  After mechanical shearing, the fine particles can be aggregated to form aggregated particles (Act 3).

  Thereafter, for example, the toner particles are obtained by washing (Act 5) using a filter press and drying (Act 6).

  In addition, between the formation of aggregated particles (Act3) and cooling (Act4), the fine particles created in a separate step are added, and the aggregated particles are heteroaggregated as mother particles to encapsulate the aggregated particles. It can be performed.

  In the developer manufacturing method according to the embodiment, mechanical shearing is performed using a high-pressure homogenizer.

  A high-pressure homogenizer is a device that atomizes particles by shearing force caused by contraction flow generated by applying high pressure to pores (hereinafter referred to as nozzles) with a high-pressure pump such as a plunger pump and passing slurry. When the particles contain a thermoplastic resin, the particles can be atomized without solvent by heating to a temperature equal to or higher than the Tg of the resin to bring the resin into a molten state. The high-pressure homogenizer has a high shearing force, so that it can instantaneously provide a shearing force in addition to a high atomization ability as compared with a general rotor-stator type stirrer. For this reason, it is suitable for atomization of resin which may be hydrolyzed such as polyester resin. However, in the high-pressure homogenizer, when the particle size of the atomized particles is large, clogging is likely to occur in a check valve that is essential for applying high pressure to the nozzle.

  FIG. 2 is a schematic view showing an example of a check valve mounted on the high-pressure homogenizer.

  FIG. 2A shows a state where the check valve is open, and FIG. 2B shows a state where the check valve is closed.

  As shown, the check valve 20 is installed in a conduit and has a seal 21 having a spring 23, a ball 22 and an opening for receiving the ball 22 therein.

  The ball 22 is made of a metal such as stainless steel, and the seal 21 is generally made of a resin material, and a material that can prevent the ball from being worn by the force of the high-pressure pump is used.

  In general, at least two check valves are mounted on the material inflow side and the outflow side for each high-pressure pump.

On the other hand, in the closed state, the ball 22 is in close contact with the seal 21 to block the opening, and the fluid cannot flow into the conduit.

  2 (a), the check valve on the inflow side is opened by the liquid feed pump, and then, as shown in FIG. 2 (b), the reverse check of the inflow side is performed by the high pressure pump. The material is supplied to the atomization section by closing the check valve and simultaneously opening the check valve on the outflow side.

  A check valve is installed to prevent backflow of material in this series of flows, but when it contains coarse particles of 100 μm or more, when the spring is compressed by the force of the liquid feed pump and high pressure pump, As a result, the material sticks and clogging occurs. Further, when the ball is struck against the seal by the force of the high-pressure pump, clogging also occurs when the material adheres to the ball and the seal.

  Although depending on the shape of the check valve used, etc., this clogging is noticeable when particles having a particle diameter of 100 μm or more are generally included. When the toner composition kneaded product is atomized, the melt kneaded product can be pulverized or emulsified in a dry or wet manner so as not to contain particles of 100 μm or more. Specifically, when there are coarse particles that do not pass through a sieve having a mesh size of 300 μm, clogging often occurs and stable treatment cannot be performed in many cases.

  In contrast, in the developer manufacturing method according to the embodiment, the check valve is provided with an impact applying portion, and mechanical shearing is performed while applying an impact from the impact applying portion to prevent the check valve from being clogged. Prevents clogging.

  In FIG. 3, the schematic showing an example of the high voltage | pressure homogenizer structure which can be used for embodiment is shown.

  As shown in the figure, the high-pressure homogenizer 10 is provided in a check valve 12, 13 and a check valve 12 provided on the upstream side and the downstream side of the hopper tank 1, the liquid feed pump 2, the high-pressure pump 3, and the high-pressure pump 3, respectively. The impact applying unit 14 provided, the impact applying unit 15 provided in the check valve 13, the heating unit 4, the atomization unit 5, the decompression unit 6, the cooling unit 7, and the decompression unit 8 are arranged in order, Including piping to be connected.

  The hopper tank 1 is a tank into which the dispersion liquid is charged. When the apparatus is in operation, it is necessary to always fill the liquid so as not to send air into the apparatus. In the case where the treatment liquid has a large particle size and a sedimentation property, a stirrer can be further provided.

  The impact applying unit 14 and the impact applying unit 15 are connected to the impact applying control unit 101, and the impact applying control unit 101 is connected to the control unit 102. The impact application control unit 101 can control on / off of the impact application unit 14 and the impact application unit 15, impact energy, and the like in accordance with information from the control unit 102. For example, the impact applying control unit 101 can perform on / off control of the impact applying unit 14 so as to apply 1 to 10 impacts per opening and closing of the check valve. The number of impacts can be changed as appropriate according to the occurrence of clogging. For example, the impact energy can be set to 0.1 N · m to 20 N · m. The impact energy can also be changed as appropriate according to the occurrence of clogging.

  By applying an impact to the check valve by the impact applying unit 14, the toner material particles clogged in the check valve can be shaken off. Thereby, clogging of the check valve can be easily eliminated. Even if the toner material particles to be charged are coarsely granulated, for example, even if toner material particles containing 1 to 10 coarse particles that do not pass through a sieve having a mesh opening of 300 μm are used in 1 g, the high-pressure homogenizer is used as a check valve. It is possible to operate stably without clogging. Thus, by stabilizing the operation of the high-pressure homogenizer, toner material fine particles having a desired particle diameter can be obtained efficiently and stably.

  In addition, if it is possible to use toner material particles that contain 1 to 10 coarse particles that do not pass through a 300 μm mesh sieve, it is necessary to make the toner material particles finer before introduction into the high-pressure homogenizer. Therefore, the cost for granulating the toner material particles can be suppressed. For this reason, the entire developer production becomes low cost.

  The liquid feed pump 2 is installed to continuously send the dispersion liquid to the high-pressure pump 3. It is also effective for avoiding clogging at the check valves 12 and 13 provided on the upstream side and the downstream side of the high-pressure pump 3 respectively. As the liquid feed pump 2, for example, a diaphragm pump, a tubing pump, a gear pump, or the like can be used.

  The high-pressure pump 3 is a plunger type pump and has check valves at a processing liquid inlet and a processing liquid outlet (not shown). The number of plungers is 1 to 10 depending on the production scale. In order to reduce the pulsating flow as much as possible, two or more are desirable.

  The heating unit 4 is provided with a high-pressure pipe 9 formed in a spiral shape in order to increase the heat exchange area in a heating apparatus such as an oil bath. The heating unit 4 has no problem on the upstream side or the downstream side of the high-pressure pump 3 with respect to the flow direction of the dispersion liquid, but it needs to be at least upstream of the atomization unit 5. When the heating unit 4 is installed on the upstream side of the high-pressure pump 3, a heating device may be provided to the hopper 1, but since the residence time at a high temperature is long, hydrolysis of the binder resin is likely to occur.

  The atomizing portion 5 includes a nozzle having a minute diameter for applying a strong shear. There are various nozzle diameters and shapes, but the nozzle diameter is desirably 0.05 mm to 0.5 mm, and the shape is desirably a pass-through nozzle or a collision nozzle. In addition, this nozzle may be composed of multiple stages, and in the case of multiple stages, a plurality of different nozzle diameters may be arranged. The method of arranging a plurality may be parallel or serial. The nozzle material is diamond or the like that can withstand high pressure.

  The cooling unit 7 is provided with a pipe 11 that is formed in a spiral shape in order to increase the heat exchange area in a bath in which cold water flows continuously.

  If necessary, decompression units 6 and 8 can be provided before and after the cooling unit 7. As a configuration of the decompression unit, one or more cells having a flow path larger than the nozzle diameter of the atomization unit 5 and smaller than the diameter of the connection pipe or one or more two-way valves are arranged.

  The treatment by this high pressure type wet atomizer is performed as follows.

  First, the processing liquid is put into a hopper and atomization processing is performed.

  The treatment liquid is heated to the glass transition temperature Tg or higher of the binder resin. The reason for heating is to melt the binder resin.

  This heating temperature varies depending on the melting characteristics of the binder resin. Resins that are easily melted are satisfactory even at low temperatures, but resins that are difficult to melt require high temperatures. Further, in the case of the method of heating by passing through the heat exchanger continuously, the flow rate of the dispersion and the length of the heat exchange pipe are also affected. When the flow rate is fast or when the piping is short, a high temperature is required. Conversely, when the flow rate is slow or when the piping is long, the dispersion is sufficiently heated, so that the treatment can be performed at a low temperature. When the flow rate is 300 to 400 cc / min, the heat exchange pipe is 3/8 inch and 12 m high pressure pipe, the binder resin Tg is 60 ° C., and the toner softening point Tm is 130 ° C., the heating temperature is 100 ° C. to 200 ° C. Good. The heating temperature is preferably in the range of glass transition temperature Tg to Tg + 150 ° C. When the heating temperature is too high, the binder resin tends to be hydrolyzed. When the heating temperature is about Tg to Tg + 150 ° C., there is no problem that the fixing property is deteriorated.

The softening point of the toner is measured by the temperature rising method of a flow tester CFT-500 manufactured by Shimadzu Corporation, and the point on the curve corresponding to 2 mm of the plunger lowering amount is defined as the softening point from the flowchart.

  Next, the heated dispersion is sheared while applying a pressure of 10 MPa or more. At this time, it is the nozzle that gives the shear. The molten toner component is atomized by passing through the nozzle while applying a high pressure of 10 MPa or more. The pressure at this time is preferably 10 MPa to 300 MPa.

  Finally, cool to below Tg. By this cooling, the melted fine particles are solidified. Since the processing liquid is rapidly cooled, aggregation and coalescence due to cooling are less likely to occur.

  If necessary, a back pressure may be applied before or after the cooling unit, or a reduced pressure may be applied. Back pressure or reduced pressure means that atmospheric pressure is not released immediately after passing through the nozzle, but is returned to near atmospheric pressure in one stage (back pressure) or multiple stages (reduced pressure). The pressure after passing through the back pressure part or the decompression part is 0.1 MPa to 10 MPa, preferably 0.1 to 5 MPa. It is further preferable that the decompression unit has a plurality of cells or valves having different diameters. By reducing the pressure in multiple stages, fine particles with few coarse particles and a sharp particle size distribution can be obtained.

  For example, an alkaline cleaning liquid can be used for cleaning the high-pressure type wet atomizer. Dirt in the piping can be easily removed, and contamination with the next processing liquid can be minimized.

  As described above, fine particles of 2 μm or less can be obtained.

  These atomizers are provided with a heat exchanger capable of heating up to about 200 ° C. upstream of the atomization section. Further, a heat exchange device capable of cooling to Tg or less of the resin is provided in the downstream part of the atomization part. Thereby, particles of micron to submicron order can be obtained.

  When particles of 3 to 8 μm are obtained by atomization, they may be washed and dried as they are to form toner, but after obtaining particles of 3 μm or less, particles of 3 to 8 μm are obtained by agglomerating those particles. It is desirable. By performing the aggregation process, toner particles having a sharp particle size distribution and uniformly enclosing the toner component can be obtained.

  In the method for producing a developer according to the embodiment, in the method of obtaining toner by agglomerating the particles of the toner composition with at least a high-pressure homogenizer and then aggregating the particles, the following configuration is further adopted, and the opening is 300 μm. Particles with less than 10 coarse particles per gram that do not pass through a mesh screen can be stably atomized with a high-pressure homogenizer without clogging with a check valve.

  At least one impact applying portion is provided in the high pressure homogenizer check valve portion.

  For example, the number of times of impact application is 1 to 10 times per opening and closing of the reverse valve.

  For example, the applied impact energy is 0.1 N · m or more and 20 N · m or less.

  For example, the impact applying unit is a hammering device.

  The purpose of the impact applying unit is to apply a strong impact to the target object by a hammering device such as a vibrator or knocker, and to prevent the adhesion, clogging, etc. of powder generated in tanks, ducts, hopper chutes, etc. In addition, it has been used to remove residues and assist filling in powder production facilities including toner.

  The impact imparting portion in the embodiment imparts an impact to the high-pressure homogenizer check valve portion, whereby coarse particles that are clogged by the check valve can smoothly pass through the check valve.

  The number of impacts applied during atomization by the high-pressure homogenizer is preferably 1 to 10 times per opening / closing of the check valve, more preferably 3 to 6 times, although it depends on the conditions of atomization treatment. . If it is less than once per opening / closing of the check valve, coarse particles clogged inside the check valve cannot be passed. If it is more than 10 times, there is a high possibility that the high-pressure homogenizer pipe and the check valve will be damaged in continuous processing.

  Further, the impact applied by the impact applying portion is preferably 0.1 N · m or more and 20 N · m or less, more preferably 0.5 N · m or more and 10 N · m or less as the collision energy. If it is less than 0.1 N · m, a sufficient effect cannot be obtained even if the number of impacts is increased. In addition, due to the strong energy at 20 N · m or more, in addition to the high-pressure homogenizer pipe and the check valve in continuous processing, there is a high possibility that the nozzle will also be vibrated and damaged.

  Although there is no restriction | limiting in particular as an impact provision part, A hammering apparatus is desirable. The hammering device includes a striking unit that imparts an impact, and a driving force imparting unit that imparts a driving force that causes the striking unit to collide with an object. For the hitting means, for example, a metal cylindrical member such as a piston rod can be used. Moreover, it is preferable that the impact imparting surface that imparts an impact to the accommodation facility and the transport facility of the striking means is covered with an elastic body such as rubber, elastomer, or synthetic resin. As a result, noise at the time of impact application can be reduced, and damage to equipment can also be prevented. As the driving force applying means, for example, a device that applies stress to the striking means using electromagnetic force, air, or the like can be used.

A known hammering device can be used, such as an electromagnetic maghammer (trade name, manufactured by Nippon Magnetics Co., Ltd.), an air knocker, an electric knocker (both trade names, manufactured by Seishin Corporation), etc. Can be mentioned.

  There is no particular limitation on the high-pressure homogenizer used in the embodiment, NANO3000 (beautiful grains), Nanomizer (Yoshida Kikai Kogyo), Starburst (Sugino Machine), Microfluidizer (Mizuho Industry), Homogenizer (Sanwa Machine), etc. It can be applied to products that are generally marketed or combinations thereof, but when atomizing a thermoplastic resin such as polyester, at least one heat exchanger for heating is installed in front of the nozzle. What is done is desirable. Further, when the heating temperature is set to 100 ° C. or higher, it is necessary to install at least one cooling heat exchanger on the downstream side of the nozzle portion. Furthermore, in view of the uniformity of the residence time of the slurry, it is desirable that at least two or more high-pressure pumps be installed so that a high pressure can be maintained at all times and there is little pulsation.

Binder resin It is desirable to use a polyester resin excellent in fixability as the binder resin.

  Further, the following colorant, release agent, and charge control agent can be mixed in the toner material of the developer according to the embodiment.

Colorant Examples of the colorant used in the present invention include carbon black, organic or inorganic pigments and dyes. For example, carbon black includes acetylene black, furnace black, thermal black, channel black, ketjen black, and the like. Examples of yellow pigments include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 65, 73, 74, 81, 83, 93, 95, 97, 98, 109, 117, 120, 137, 138, 139, 147, 151, 154, 167, 173, 180, 181, 183, 185, C.I. I. Bat yellow 1, 3, 20, etc. are mentioned. These may be used alone or in combination. Examples of magenta pigments include C.I. 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, 49, 50, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 146, 150, 163, 184, 185, 202, 206, 207, 209, 238, C.I. I. Pigment violet 19, C.I. I. Bat red 1, 2, 10, 13, 15, 23, 29, 35, etc. are mentioned. These may be used alone or in combination. Examples of cyan pigments include C.I. I. Pigment blue 2, 3, 15, 16, 17, C.I. I. Bat Blue 6, C.I. I. Acid Blue 45 and the like. These may be used alone or in combination.

Release agent (wax)
Examples of the wax include aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, polyolefin copolymer, polyolefin wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax, and aliphatic hydrocarbon waxes such as oxidized polyethylene wax. Oxide of wax or block copolymer thereof, candelilla wax, carnauba wax, wood wax, jojoba wax, plant wax such as rice wax, beeswax, animal wax such as lanolin, whale wax, ozokerite, ceresin Mineral waxes such as petrolatum, montanic ester waxes, waxes based on fatty acid esters such as castor wax, and fatty acid esters such as deoxidized carnauba wax. The other is exemplified such as those de-oxidation all. Further, saturated linear fatty acids such as palmitic acid, stearic acid, montanic acid, or long-chain alkyl carboxylic acids having a long-chain alkyl group, unsaturated fatty acids such as brassic acid, eleostearic acid, parinaric acid, stearyl alcohol , Saturated alcohols such as eicosyl alcohol, behenyl alcohol, carnauvir alcohol, seryl alcohol, melyl alcohol, or long chain alkyl alcohols having a long chain alkyl group, polyhydric alcohols such as sorbitol, linoleic acid amide, oleic acid Amide, fatty acid amide such as lauric acid amide, methylene bis stearic acid amide, ethylene biscapric acid amide, ethylene bis lauric acid amide, saturated fatty acid bis amide such as hexamethylene bis stearic acid amide, Unsaturated fatty acid amides such as lenbis oleic acid amide, hexamethylene bis oleic acid amide, N, N′-dioleyl adipic acid amide, N, N′-dioleyl sebacic acid amide, m-xylene bis stearic acid amide, Aromatic bisamides such as N, N'-distearylisophthalic acid amide, fatty acid metal salts such as calcium stearate, calcium laurate, zinc stearate and magnesium stearate (generally referred to as metal soap), aliphatic Hydroxyl obtained by hydrogenating waxes grafted to hydrocarbon waxes using vinyl monomers such as styrene and acrylic acid, partially esterified products of fatty acids and polyhydric alcohols such as behenic acid monoglycerides, and vegetable oils and fats. Methyl Este Having a Group Compounds.

Charge Control Agent As the charge control agent for controlling the triboelectric charge amount, for example, a metal-containing azo compound is used, and the metal element is preferably an iron, cobalt, chromium complex, complex salt, or a mixture thereof. In addition, a metal-containing salicylic acid derivative compound can be used, and the metal element is preferably a complex, complex salt of zirconium, zinc, chromium, boron, or a mixture thereof.

  Further, in the developer manufacturing method according to the embodiment, the following surfactant and pH adjuster can be mixed in the toner material dispersion.

Surfactant Examples of the surfactant that can be used in the present invention include anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap, amine salt type, quaternary ammonium salt, and the like. Nonionic surfactants such as cationic surfactants such as molds, polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. These surfactants may be used alone or in combination of two or more.

pH adjuster
Although it does not restrict | limit especially as a pH adjuster which can be used for this invention, For example, when using polyester resin as binder resin, bases, such as an amine compound, can be used besides sodium hydroxide, potassium hydroxide, etc. . Examples of amine compounds include dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, propylamine, isopropylamine, dipropylamine, butylamine, isobutylamine, sec-butylamine, monoethanolamine, diethanolamine, triethanolamine, triisopropanolamine. , Isopropanolamine, dimethylethanolamine, diethylethanolamine, N-butyldiethanolamine, N, N-dimethyl-1,3-diaminopropane, N, N-diethyl-1,3-diaminopropane and the like. From the viewpoint of improving the self-dispersibility of the polyester resin and the performance, the pH adjuster is particularly preferably an organic amine compound.

  Hereinafter, the embodiment will be described more specifically with reference to examples.

Preparation of granulated toner material 90 parts by weight of polyester resin (glass transition temperature 58 ° C., acid value 6, weight average molecular weight Mw 13,658) as binder resin, 5 parts by weight of cyan pigment as colorant, 4 parts by weight of rice wax And 1 part by weight of a zirconia metal complex as a charge control agent were mixed, and then melt-kneaded in a biaxial kneader set at 120 ° C. to obtain a kneaded product. The obtained kneaded material was coarsely pulverized with a hammer mill manufactured by Nara Machinery Co., Ltd. until passed through a 1.2 mm mesh to obtain coarse particles. Subsequently, a 200 μm mesh was placed in a bantam mill manufactured by Hosokawa Micron Corporation and further pulverized to obtain medium crushed particles having an average volume particle size of 58 μm. The obtained crushed particles are designated as crushed particles A. When 1 g of the crushed particles A was sieved with an opening of 300 μm mesh, 12 coarse particles remained on the mesh.

  The crushed particles A were again treated with a bantam mill to obtain crushed particles having an average particle size of 55 μm. The obtained crushed particles are referred to as crushed particles B. When 1 g of the crushed particles B was sieved with an opening of 300 μm mesh, 9 coarse particles remained on the mesh.

  The crushed particles B were again treated with a bantam mill to obtain crushed particles having an average particle diameter of 50 μm. The obtained crushed particles are designated as crushed particles C. When 1 g of the crushed particles C were sieved with an opening of 300 μm mesh, 5 coarse particles remained on the mesh.

Example 1
A mixed liquid was prepared using 30 parts by weight of the crushed particles B, 0.3 parts by weight of sodium dodecylbenzenesulfonate as an anionic surfactant, and 69.7 parts by weight of ion-exchanged water using an agitator, and the bubbles in the mixed liquid were vacuumed. After removal by stirring, 0.63 parts by weight of dimethylaminoethanol was added to adjust the pH to 11. This mixed solution was set to a heating system of 180 ° C, charged into NANO3000 with an air knocker SEK-3 (manufactured by Seishin Enterprise Co., Ltd.) installed in the reverse valve, and continuously at a processing pressure of 150 MPa using a 0.13 µm through-type nozzle. As a result of the treatment, the atomization treatment did not stop even after continuous treatment for 5 hours.

  As a result of measuring the volume average particle size of the obtained fine particles with SALD7000 (manufactured by Shimadzu Corporation), it was 0.30 μm. The atomized dispersion was adjusted to a solid content concentration of 10%, hydrochloric acid was added dropwise to adjust the pH to 5, and then the temperature was raised to 85 ° C. at a rate of 0.5 ° C./min. As a result of the time retention, a toner particle dispersion having a sharp particle size distribution with a volume average particle size of 5.0 μm and a standard deviation of 1.86 μm was obtained.

  The solid content of the obtained toner particle dispersion was repeatedly filtered and washed with ion-exchanged water until the filtrate had a conductivity of less than 50 μS / cm. Thereafter, the toner was dried with a vacuum dryer until the water content became 1.0% by weight or less to obtain toner particles. Further, after drying, 2 parts by weight of hydrophobic silica and 0.5 parts by weight of titanium oxide were adhered to the toner particle surface as additives with respect to 100 parts by weight of the toner particles to obtain a desired toner.

  Further, when the toner was mixed with carrier particles and imaged by a two-component copying machine, a good image was obtained.

Example 2
A continuous treatment was carried out in the same manner as in Example 1 except that the middle ground particles B were changed to the middle ground particles C. As a result, the atomization treatment did not stop even after the treatment for 5 hours.

  After a toner was obtained in the same manner as in Example 1, the toner was further mixed with carrier particles and imaged with a two-component copying machine, and a good image was obtained.

Comparative Example 1
When continuous treatment was carried out in the same manner as in Example 1 except that the intermediately pulverized particles B were changed to intermediately pulverized particles A, clogging occurred at 12 minutes after the check valve, and the atomization process was stopped.

Comparative Example 2
When continuous processing was performed in the same manner as in Example 1 except that no air knocker was mounted on the check valve, clogging occurred at the check valve 15 minutes after the start of continuous processing, and the atomization processing stopped. Oops.

Comparative Example 3
When continuous processing was performed in the same manner as in Example 2 except that no air knocker was mounted on the check valve portion, clogging occurred at the check valve 25 minutes after the start of continuous processing, and the atomization processing stopped. Oops.

  According to the embodiment, when atomizing using a high-pressure homogenizer, it is possible to stably atomize particles having less than 10 coarse particles per gram that do not pass through a sieve having an opening of 300 μm mesh. It has been found that it is not necessary to finely pulverize the particles before they are put into the high-pressure homogenizer, which makes it possible to produce toner particles with low energy and low cost.

    DESCRIPTION OF SYMBOLS 3 ... High pressure pump, 5 ... Atomization part, 10 ... High pressure homogenizer, 12, 13 ... Check valve, 14, 15 ... Impact application part

Claims (9)

A step of preparing a toner material dispersion containing a granulated toner material containing at least a binder resin and an aqueous medium, and a pressure unit, a heating unit, and a nozzle unit including a check valve provided with an impact applying unit The dispersion is passed through a high-pressure homogenizer including a cooling unit, and the dispersion is subjected to mechanical shearing while preventing the check valve from being clogged by applying an impact to the check valve from the impact applying unit. A method for producing a developer, comprising the step of finely forming the granular toner material to form fine particles having a size smaller than the size of the granular toner material.   2. The method according to claim 1, wherein the granulated toner material contains 0 or 1 to 10 coarse particles which do not pass through a sieve having a mesh size of 300 [mu] m in 1 g.   The method according to claim 1, wherein the impact applying unit includes an impact applying control unit that controls an operation of the impact applying unit, and a control unit connected to the impact applying control unit.   The method according to claim 3, wherein the impact applying unit is controlled by the impact applying control unit so as to apply 1 to 10 impacts per opening and closing of the check valve.   5. The method according to claim 3, wherein the impact applying unit is controlled by the impact applying control unit such that an impact energy is 0.1 N · m to 20 N · m.   The method according to claim 3, wherein the impact applying unit is a hammering device.   The method according to any one of claims 1 to 6, wherein the granulated toner material is obtained by a step of melt-kneading and coarsely pulverizing the toner material containing the binder resin.   The method according to any one of claims 1 to 7, further comprising the step of aggregating the fine particles to form aggregated particles.   9. The method according to claim 1, wherein the granulated toner material further contains a colorant.

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