JP4363297B2 - Toner manufacturing method and manufacturing apparatus - Google Patents

Description

  The present invention relates to a toner production method for producing toner particles from a toner raw material in which a plurality of components are melt-mixed, and a toner production apparatus for carrying out the toner production method.

As a toner production method, generally, using a melt kneader or the like, first, a toner raw material composed of a plurality of components such as a binder resin, a colorant (pigment, dye), and a wax is dispersed uniformly. A method in which a mixture of melted and then cooled toner raw materials is pulverized into toner particles having a desired particle size by coarse pulverization and fine pulverization using mechanical pulverization means.
In this conventional toner manufacturing method, after the molten mixture is discharged out of the kneader, rolling cooling is started at a temperature lower than the melting point of the wax within a relatively short time (for example, 5 seconds to 10 seconds). Thus, a technique for preventing the wax in the molten mixture from re-aggregating in the cooling process and increasing the dispersion diameter has been proposed (see Patent Document 1).

JP 2001-142248 A

  According to the toner production method described in Patent Document 1, an effect of suppressing the aggregation of wax in the molten mixture to some extent can be expected, but a time difference of at least 5 seconds from the end of the melt mixing (kneader exit) to the start of cooling. In addition, there is a possibility that a sufficient re-aggregation preventing effect cannot always be obtained due to the fact that the cooling action does not easily reach the details of the molten mixture (inside the rolled product) by rolling cooling.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to effectively prevent re-aggregation of each component of the melt-mixed toner material, and toner in which each component of the toner material is uniformly dispersed It is an object of the present invention to provide a toner manufacturing method capable of manufacturing particles and a toner manufacturing apparatus suitable for the manufacturing method.

In order to achieve the above object, a first characteristic configuration of a toner production method according to the present invention includes a melt mixing step of melting and mixing a toner raw material comprising a plurality of components, and the toner raw material obtained in the melt mixing step. and fiberizing the cooling step of cooling and forming into fibers by extruding the molten mixture through a nozzle, and milling the fibrous reduction and cooled fibrous material in the fiberizing cooling step and a milling step of making toner particles a method of manufacturing a toner having, was melt-kneaded by a kneader said toner material comprises a multi-stage distribution channel of branching from static mixer and exit of the static mixer prior to the fiberizing cooling step It is in the point of melting and mixing by the channel structure .

That is cooled with after being melt-mixed so that each component of the toner material are uniformly dispersed composed of a plurality of components, the molten mixture of the toner material in the fiber of the cooling step is fiber 維状 of the melt-mixing step Therefore , re-aggregation of each component of the toner raw material is prevented, and a fibrous material maintaining a uniform dispersed state can be obtained. Then, the fibrous material is pulverized in the pulverization step, thereby producing toner particles having a desired particle size in which the respective components are uniformly dispersed.
Accordingly, there is provided a toner manufacturing method capable of effectively preventing reaggregation of each component of the melted and mixed toner material and manufacturing toner particles in which each component of the toner material is uniformly dispersed.

And, in the fiberizing cooling step, the molten mixture of the toner raw material after being formed is pushed out from the nozzle into fibers, it is cooled.
That is, in the fibers of the cooling process, the molten mixture of the toner raw material after being formed is pushed by the nozzle into fibers, continuous can be efficiently fibrous reduction in Rukoto it is cooled, pulverized In the process, since the long fibrous material is pulverized by cutting action or the like, the pulverization efficiency is increased.
Accordingly, a suitable toner manufacturing method is provided.

Furthermore, in the melt mixing step, after the toner raw material is melt-kneaded by a kneader, Prior to the fiber cooling step, the stationary mixer and the multistage branch branched from the outlet of the stationary mixer Melting and mixing is performed by a channel structure having a distribution channel.
In other words, a toner material composed of a plurality of components is first subjected to a strong force in a kneading machine And a stationary mixer located after the kneading machine and before the fiber cooling process, Mixing action in a channel structure having multistage distribution channels branched from the outlet of the static mixer And then sent to the fiber cooling process, so that the toner raw material obtained by the kneader is melted. A flow having a multistage distribution flow path for branching the mixture from the stationary mixer and the outlet of the stationary mixer The road structure can be sent to the fiber cooling process while maintaining a good melt-mixed state.
Therefore, a toner more suitable for producing toner particles in which each component of the toner raw material is uniformly dispersed A manufacturing method is provided.

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The Second characterizing feature, in addition to the first Ichitoku Cho構formed in the melt-mixing step, after the components excluding the predetermined component of the toner over the raw material was melt mixed in the kneader, the mixture pair to certain predetermined components of the toner material to a point to be melt mixed in the flow channel structure having a distribution channel of the static mixer or the multi-stage.
That is, a flow path having a static mixer or a multistage distribution flow path after melted and mixed with a kneader each component excluding a predetermined component from a toner raw material composed of a plurality of components and adding the predetermined component of the toner raw material Because it is melt-mixed in the structure , for example, for components whose characteristics change or deteriorate due to long-term melt-mixing, it is possible to shorten the melt-mixing time by post-mixing to suppress changes in characteristics and deterioration. For components that can be melt mixed with other components in a short time, unnecessary mixing energy consumption can be suppressed by post-mixing.
Therefore, a toner manufacturing method is provided in which the input configuration of each component in the melt mixing process can be appropriately set in accordance with the characteristics of each component of the toner raw material.

  Embodiments of a toner manufacturing method and a manufacturing apparatus according to the present invention will be described with reference to the drawings.

As shown in FIG. 1, the toner production method of the present invention comprises a melt mixing step of melting and mixing a toner material composed of a plurality of components such as a binder resin, a colorant, and a wax, and a toner material obtained in the melt mixing step. and a grinding step of producing toner particles by the molten mixture was pulverized and fiberizing step of cooling while fibrous reduction, fibrous reduction in fiberization cooling step and the cooled fibrous material. Then, in the above fiberizing cooling step, Rutotomoni forming form a melt mixture of toner material into fibers, cooled by blowing cold air to the fibrous material. In the above pulverization step, the pulverized product is actually classified using a pulverizer having a classification function to obtain toner particles having a desired particle size. Further, since the toner particles prepared by pulverizing the fibrous material as described above are formed in a columnar shape (such as a columnar shape), an external additive appropriately adding a fluidity improver or the like before or after the pulverization step. Processing, spheroidization, etc. are performed.

Next, the toner production apparatus of the present invention, as shown in FIG. 2, a melt mixing unit 10 for melt-mixing the toner materials composed of a plurality of components, fiberization unit for fibrous the molten mixture of the toner materials 20, and a cooling unit 30 for cooling the fibrous material that is fibrous reduction, and a crushing section 40 for crushing the fibrous material.
Then, when the correspondence with the manufacturing method of the toner 1, by the melt mixing unit 10, the melt mixing process is performed by the fiberizing unit 20 and the cooling unit 30, fiberization cooling step is performed, the grinding zone By 40, the grinding step is executed.

Specifically, it branched mixing apparatus (e.g., Hosokawa Micron Co. Cyclomix) 9, a single shaft Ekusutoru da 1 having a rotating screw 15 therein dated hopper 1A, static mixer 2, the outlet of the static mixer 2 and such flow path structure 3 having a multi-stage distribution channel 3A is provided with, between the inlet of the static mixer 2 and the outlet of the single shaft Ekusutoru da 1 are arranged a gear pump 4 driven by a motor 5 . Note that a plurality of extrusion nozzles 6 are provided side by side so as to correspond to the respective channel outlets in the final stage of the distribution channel 3A. Moreover, single shaft Ekusutoru Da 1, a gear pump 4, the static mixer 2, the flow path structure 3 is not shown, heating the toner material temperature higher than the melting point of the binder resin, for example, about 130 ° C. to 240 ° C. And a heater for reducing the viscosity.

In the above apparatus, the toner materials, once introduced from the hopper 1A to the single shaft Ekusutoru Da 1, is fed to the outlet side while being mixed becomes a molten state is heated by the heater. Melt mixture of toner material fed from the single shaft Ekusutoru Da 1, after being adjusted pressure and an extrusion rate of a gear pump 4, a flow path and a multi-stage distribution channel 3A in static mixer 2 during the flowing Mixing is promoted, and each component of the toner raw material is uniformly and finely dispersed. The fibrous material which is oriented by hot air blown from drawing air blowoff device (not shown) for with extruded into fibers downwardly from a plurality of nozzles 6 is cooled from the blower 7 is blown cold air. Incidentally, fiber維状product that has fallen down is collected in the receiving vessel 8, it is pulverized is put into pulverizer 40 for each predetermined amount.

  As the static mixer 2, a known static mixer can be used. Specifically, as shown in FIG. 2, a blade having a curved surface twisted so as to form a spiral flow path. A plurality of bodies 14 (three in the example shown in FIG. 2) are provided while adjacent to each other along the flow direction of the toner material while reversing the twist angle of the spiral.

Thus, melt mixing unit 10 is constituted by a single shaft Ekusutoru Da 1, static mixers 2 and the flow path structure 3. Further, the fiberizing unit 20 is configured by the nozzle 6 that extrudes the molten mixture of the toner raw material to form a fiber and the drawing air blowing device, and the cooling unit 30 is configured by the blower 7 that blows cold air. . Further, the pulverizer 40 corresponds to the pulverization unit 40. That is, the melt-mixing unit 10 (specifically, rotating screw 15) movable mixing member with single shaft Ekusutoru da 1 as kneader for kneading the toner materials by the kneading machine (single shaft Ekusutoru da 1 and a subsequent stage) and a static mixer for 2 located in front of the fiberizing unit 20.

  The pulverizer 40 is composed of an ACM pulverizer manufactured by Hosokawa Micron Corporation, for example. Specifically, as shown in FIG. 3, the inside of a main body 43 provided with a gas inlet 41 on the lower side and a gas and powder outlet 42 on the upper side is connected to the outer grinding chamber A and the inner side by a cylindrical member 44. The pulverizing chamber A contains a rotating body 45A provided with a pulverizing member 45 and communicates with the gas inlet 41 on the lower side, and the classifying chamber B classifies coarse powder and fine powder. It communicates with the discharge port 42 via a classification mechanism 46 that allows only fine powder to pass through. The raw material (the fibrous material of the toner raw material) is fed into the pulverizing chamber A through a charging port 43A provided on the lateral side of the main body 43. The discharge port 42 is sucked and exhausted to the outside through a dust collector with a bag filter (not shown). The rotating body 45A is rotatable about the vertical axis, and the vertical hammer type pulverizing member 45 is separated from the liner 47 mounted on the inner wall of the pulverizing chamber A on the outer periphery of the rotating body 45A. Several are installed in. In the crushing chamber A, the raw material is crushed by receiving a mechanical impact force from the crushing member 45.

  The classifying mechanism 46 has a structure in which a plurality of classifying blades 49 are erected on the outer peripheral portion of a rotating body 48 that is rotatable around a vertical axis, and an air flow from the classifying chamber B acting on the pulverized material toward the discharge port 42. The fine powder and the coarse powder are separated by the difference between the conveying force and the centrifugal force applied by the rotating body 48. That is, among the pulverized material flowing into the classification chamber B from the pulverization chamber A, the fine powder having a greater conveying force due to the airflow passes through the classification blade 49 and is discharged from the discharge port 42, and the centrifugal force has a larger effect. The coarse powder to be returned returns to the crushing chamber A from below the cylindrical member 44 without passing through the classification blade 49.

  FIG. 4 shows that the wax particles 11 are well dispersed in the toner particles 12 and the dispersion diameter of the wax particles 11 is small (A), and the wax particles 11 are re-agglomerated to deteriorate the dispersibility. An example of a state (B) in which the dispersion diameter is increased is schematically shown. The toner particles 12 having a low dispersibility of the wax particles 11 are liable to break at the wax particle portion, and thus have a disadvantage that the durability as a developer is inferior.

  FIG. 5 is an example of data indicating that the light transmittance characteristics of the toner particles differ depending on whether the dispersibility of the pigment in the toner particles is good or not. When the dispersibility is good, the transmittance is high, whereas when the dispersibility is poor, the transmittance is low. In particular, in the case of color toners, toner of each color is formed in a layered state on the transfer material. Therefore, when the toner transmittance is low, the color of the lower layer does not appear upward, and a color image is obtained. There arises a disadvantage that a good color reproduction range cannot be obtained.

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In the above embodiment, the fiberizing cooling step and the cooling section 30, as a means for cooling the fibrous material of the toner material, is constituted by a blower 7 for blowing cold air, the extrusion speed is very fast when extruding from the nozzle 6 Since there is some (for example, 40 m / sec), it is also possible to cool by maintaining the temperature condition of the extruded surroundings at a normal temperature or a low temperature condition without providing a blower as described above.

In the above embodiment, in the pulverization step and the pulverization unit 40, the fibrous material is once collected in the container 8 and then charged into the pulverizer 40. However , the fibrous material is continuously pulverized. It is also possible to configure so that it is charged to 40.

In the above embodiment, the melt mixing unit 10 is configured to melt and mix the components of the toner raw material together from the beginning. However, after melt mixing the components of the toner raw material excluding the predetermined components, the mixture is added to the mixture. On the other hand, a predetermined component of the toner raw material may be melted and mixed. Here, as components to be mixed later, waxes other than the binder resin, colorants such as pigments and dyes, charge control agents, and grinding aids such as silica can be appropriately selected.
Position of mixing post the predetermined component in the melt mixing unit 10, kneader range from the exit point to the entrance point of the static mixer Sa 2 (single shaft Ekusutoru Da 1), the internal flow path of the static mixer support 2, range from the exit point of the static mixer support 2 to the inlet portion of the flow path structure 3, in internal channel 3A of the flow path structure 3 can be set at an arbitrary position. 6, after the melt mixing the components of toner material excluding the wax single shaft Ekusutoru da 1 shows an example of mixing the wax from the inlet portion of the static mixer Sa 2. In FIG. 6, 16 is a melting apparatus for wax, and 17 is a gear pump for wax.

  In addition, the apparatus for melt mixing used in the melt mixing process or the melt mixing unit 10 is not limited to the apparatus used in the above embodiment, and various apparatuses can be used.

  Next, an example of a toner manufacturing method according to the present invention will be described by taking four color toners (black, cyan, magenta, yellow) as an example.

(Black toner)
100 parts by weight of a polyester resin (Tg: 64 ° C., outflow start temperature (measured by a flow tester manufactured by Shimadzu Corporation, hereinafter the same): 119 ° C.), 10 parts by weight of carbon black, 3 parts by weight of zinc salicylate, and 5 parts by weight of carnauba wax the parts, after pre-mixed in the mixing device 9, and melted by supplying a single shaft Ekusutoru da 1, after pressure regulation by the gear pump 4 (about 4.2MPa a gear pump below), still in the melt temperature 0.99 ° C. The extrusion was supplied to the mold mixer 2. Then, after being melt-mixed in the static mixer 2, it was stretched to a wire diameter of 5.0 μm with hot air while being extruded from a nozzle 6 having a pore diameter of 300 μm, and then cooled to obtain fine particle precursor fibers. The fiber generation rate at this time was calculated to be about 40 m / sec from the extrusion amount and the fiber diameter.

  Further, the fine particle precursor fiber was pulverized and classified by the classifier built-in type pulverizer (ACM pulverizer). As a result, the volume average diameter was 6.4 μm, the number average diameter was 5.3 μm, and the volume standard was 12 μm or more. Toner particles having a particle size distribution of 1.4%, a particle size of 16 μm or more of 0%, and a fine particle size of less than 5 μm on the number basis was 11.2%.

  Next, 100 parts by weight of the toner particles, 0.02 parts by weight of zinc stearate (average particle diameter 0.3 μm), 0.75 parts by weight of silica (particle diameter 12 nm calculated from the specific surface area), and silica (from the specific surface area). A black developer was obtained by stirring and mixing 0.75 parts by weight of a calculated particle diameter of 30 nm using a compression shear mixer (for example, Mechanofusion manufactured by Hosokawa Micron Corporation, the same applies hereinafter).

(Cyan toner)
100 parts by weight of a polyester resin (Tg: 64 ° C., outflow start temperature: 119 ° C.), 5 parts by weight of copper phthalocyanine pigment, 3 parts by weight of lecithin, and 5 parts by weight of carnauba wax are mixed under the same conditions as in Example 1. Through a process such as melting, extrusion from a nozzle, etc., a fine particle precursor fiber having a wire diameter of 5.0 μm was obtained. Further, this fine particle precursor fiber was pulverized by the above-mentioned classifier built-in type pulverizer in the same manner as in Example 1 to obtain particles having a volume average diameter of 6.5 μm, a number average diameter of 5.6 μm, and 12 μm or more on a volume basis. Toner particles having a particle size distribution with a ratio of 1.5%, a ratio of particles of 16 μm or more of 0%, and a ratio of fine powder particles of less than 5 μm based on the number of 10.2% were obtained. Next, zinc stearate and silica were mixed with the toner particles under the same conditions as in Example 1, and the mixture was stirred and mixed by the compression shear mixer to obtain a cyan developer.

(Magenta toner)
100 parts by weight of a polyester resin (Tg: 64 ° C., outflow start temperature: 119 ° C.), 5 parts by weight of a quinacridone pigment, 3 parts by weight of lecithin, and 5 parts by weight of carnauba wax are mixed under the same conditions as in Example 1. Through steps such as melting and extrusion from a nozzle, fine particle precursor fibers having a wire diameter of 5.0 μm were obtained. Further, this fine particle precursor fiber was pulverized by the above-mentioned classifier built-in type pulverizer in the same manner as in Example 1 to obtain particles having a volume average diameter of 6.5 μm, a number average diameter of 5.5 μm, and 12 μm or more on a volume basis. Toner particles having a particle size distribution of 1.4%, a ratio of particles of 16 μm or more of 0%, and a ratio of fine powder particles of less than 5 μm based on the number of 10.4% were obtained. Next, zinc stearate and silica were mixed with the toner particles under the same conditions as in Example 1 and stirred and mixed with the compression shear mixer to obtain a magenta developer.

(Yellow toner)
100 parts by weight of a polyester resin (Tg: 64 ° C., outflow start temperature: 119 ° C.), 5 parts by weight of a disazo pigment, 3 parts by weight of lecithin, and 5 parts by weight of carnauba wax are mixed under the same conditions as in Example 1. Through steps such as melting and extrusion from a nozzle, fine particle precursor fibers having a wire diameter of 5.0 μm were obtained. Further, this fine particle precursor fiber was pulverized by the above-mentioned classifier built-in type pulverizer in the same manner as in Example 1 to obtain particles having a volume average diameter of 6.6 μm, a number average diameter of 5.7 μm, and 12 μm or more on a volume basis. Toner particles having a particle size distribution of 1.6%, a ratio of particles of 16 μm or more being 0%, and a ratio of fine powder particles of less than 5 μm based on the number of 9.4% were obtained. Next, zinc stearate and silica were mixed with the toner particles under the same conditions as in Example 1 and stirred and mixed with the compression shear mixer to obtain a yellow developer.

  Next, the dispersion state of the raw materials in the developer particles of each color obtained as described above was observed. For example, for cyan developer particles, after metal coating, embedding in epoxy resin and cutting, the cut surface is dyed with ruthenium tetroxide, and an ultra-foil slice is prepared to produce a cross-section of the developer particles. A test sample was obtained. When this super foil section was observed with a TEM, the cyan pigment was uniformly dispersed and no large cyan pigment particles were observed. Moreover, it was confirmed that the carnauba wax was finely dispersed in about 0.3 μm grains. Similarly, good dispersion of pigments and waxes could be confirmed for the developer particles of other colors.

Finally, the four color developer particles obtained as described above were subjected to image evaluation using an image device (printer LP-7000C manufactured by Seiko Epson Corporation). As a result, the obtained image had a high and stable image density, a good density control (gradation), a high resolution, and a sharp image. Moreover, there were no background stains or dust at the time of transfer. In addition, although this was not able to be observed with TEM, this confirms that the dispersion of the charge control agent (zinc salicylate, lecithin) was good.
In addition, with respect to changes in the charge amount when a durability test (for example, 10,000 sheet image output conditions) is performed, each of the four color developers is ± 7.% relative to the initial charge amount (usually 20 to 30 μC / g). It is within the range of about 5 μC / g, and good results are obtained with respect to charging stability.

  The toner production method and production apparatus according to the present invention can be widely applied to the production of developing toners, for example, for color and high image quality, which require a large amount of toner components.

Process diagram of toner production method according to the present invention 1 is an overall configuration diagram showing a toner manufacturing apparatus according to the present invention. Sectional view showing the structure of the crusher Cross-sectional schematic diagram showing the dispersion state of components in toner particles The graph which shows an example of the toner characteristic by the difference in the dispersion state of a toner component FIG. 3 is an overall configuration diagram illustrating a toner manufacturing apparatus according to another embodiment of the present invention.

1 single shaft Ekusutoru da 2 static mixer Sa 3 flow path structure 3A passage 4 gear pump 5 motor 6 nozzle 7 blower 8 containers 9 mixer 10 melt mixing unit 11 wax particles 12 Toner particles 14 sail body 15 kneading member 16 melter 17 gear pump 20 fiberizing unit 30 cooling unit 40 crushing section (crusher)
41 Gas introduction port 42 Discharge port 43 Main body 44 Cylindrical member 45 Grinding member 45A Rotating body 46 Classification mechanism 47 Liner 48 Rotating body 49 Classification blade

Claims (2)

A melt mixing step of melt-mixing a toner material composed of a plurality of components;
And fiberizing the cooling step of cooling and forming into fibers shape extruding molten mixture of the toner material obtained by the melt-mixing step from the nozzle,
A method for manufacturing a toner and a pulverization step of producing toner particles by pulverizing fibrous reduction and cooled fibrous material in the fiberizing cooling step,
After the melt mixing step, the toner raw material is melt kneaded by a kneader, and before the fiber cooling step, a flow channel structure having a stationary mixer and a multistage distribution channel branched from the outlet of the stationary mixer And a toner production method characterized by melting and mixing. In the melt mixing step, each component excluding a predetermined component of the toner raw material is mixed with the mixture. After being melt-mixed by a kneader, the predetermined component of the toner raw material is added to the static mixture in the melt The mixture is melt-mixed by a mixer or a channel structure having the multistage distribution channel. The toner production method according to claim 1.