JP2769859B2 - Color toner manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for efficiently pulverizing and classifying solid particles having a binder resin to obtain a color toner having a predetermined particle size, and particularly relates to a method for producing a color toner having a predetermined particle size. The present invention relates to a method for producing a color toner in which granular transfer omission caused by the above coarse particles is improved.

[Prior Art] Generally, a toner obtained by a pulverization method uses a styrene-based resin, a styrene-acrylic resin, or a polyester-based resin as a binder resin, and is used as a raw material such as a coloring material or a magnetic material, an offset inhibitor, and a charge control agent. Is melted and kneaded, and then cooled, pulverized and classified.

Conventionally, as a method for producing the toner, a combination of a fine pulverizer and a classifier is known. As an example, a high-pressure air stream is ejected from a jet nozzle, and the raw material particles are entrained in the jet air stream, and the particles are mutually interlinked. A so-called jet mill that advances pulverization by collision or collision with a wall or other collision body is used, and one pulverizing means and one or two classifying means are combined and provided for pulverization. FIG. 1 is a flowchart showing one example of a conventional pulverizing method. In FIG. 1, the raw material is introduced into the first classification means together with the pulverized material, and is divided into the first coarse powder and the first classified powder. The first coarse powder is pulverized through the pulverizing means and is again introduced into the first classifying means. On the other hand, the first classified powder is introduced into the second classifying means in the next step, and is classified into the classified fine powder and the second classified powder. Here, the second classified powder is used as a product.

[Problems to be Solved by the Invention] However, in this system, in addition to the raw material powder, toners of various particle sizes in the course of pulverization are circulated between the pulverization unit and the classification unit in the first classification unit. Therefore, the particle size becomes very broad, and the classifying means and the crushing means are operated under a very large load. Therefore, the first classified powder containing a large amount of coarse powder that has not been sufficiently classified is likely to be generated. Since the second classifying means is a step mainly for removing fine powder in the first classifying powder, the coarse components which could not be classified by the first classifying means are necessarily included in the toner as a final product. Generally, a toner having a volume average diameter of about 7 to 20 μm is used, but the coarse powder in the present invention has a particle diameter of 30 μm or more.

As described above, the coarse powder is a coarse particle having a relatively large particle size and is bulky, so that the charge amount per particle is higher than that of the other toner particles. Therefore, in the developing step in electrophotography, the toner is more easily developed than other toner particles. However, in the transfer step, as shown in FIG. 2, the photosensitive member and the transfer support are sandwiched between each other, and at first glance, they exhibit spacer particle behavior, hinder the adhesion between the photosensitive member and the support, and generate a sufficient transfer electric field. I can't get it. As described above, since the coarse powder has a high charge amount, the transfer to the transfer support becomes insufficient even when a normal transfer electric field is obtained. For this reason, in the copy image obtained on the transfer support, a large number of images (hereinafter referred to as transfer omission) in which white transfer is lost in a granular form having a diameter of about 100 μm to 1 mm due to poor transfer of the coarse powder occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a toner capable of obtaining a toner having extremely reduced coarse powder. Also,
Another object of the present invention is to provide a method for producing a toner having a process in which no deposits are formed even after a long operation. Another object of the present invention is to provide a toner manufacturing method capable of obtaining a toner without granular transfer omission.

[Means and Actions for Solving the Problems] According to a new classification device by the present applicant, the first classified powder is divided into at least three multi-divided classification regions as shown in FIG. This is a device that is introduced and lowered in a curved line due to the Coanda effect, and classified into coarse powder, second classified powder, and fine powder. By introducing this apparatus, the coarse powder contained in the first classified powder can be removed no matter how much, and the transfer omission is remarkably improved.

However, even when this step is used, the transfer omission is remarkably improved in the initial stage of the introduction of the first classification powder, but as the processing amount of the first classification powder increases, in other words, as the operation time of the classification device becomes longer, The problem of an increase in coarse powder in the two-class powder remains. This is because the toner fusing material adheres to the dispersion louver and the classification louver which are the fine powder discharge port (and / or) discharge pipe and the air inlet shown in FIG. 3, and they are separated and separated during the operation. The amount of coarse particles mixed in the classified powder increases, and the particles easily jump into the second classified powder. Further, adhesion of the toner fused material occurs in the classification edge and the discharge pipe in FIG. It was found that this was due to the peeling and separation of the powder and the mixing into the second classified powder. Therefore, there is almost no coarse product in the second classified powder because there is no adhered product at the initial stage of the pulverized raw material introduction, but the adhered and desorbed material becomes coarse particles with the operation of the apparatus by the first and second classifying means. To increase the mixing ratio.

Usually, a binder resin for toner having a glass transition point of about 40 to 70 ° C. is mainly used. This is because the fixability of the toner to the transfer support is taken into account, and the toner is designed to be fixed to the transfer support with a small amount of heat when passing through the fixing device. Since a resin having such a glass transition point is classified as a soft resin having a low softening point, when a powder composed thereof passes through a classification device which is a first and a second classification means, a fine powder outlet is provided. Small amounts of frictional heat and impact heat generated in the (and / or) discharge pipe, air inlet, classification edge, and discharge pipe can easily cause fusing or adhering material in this area. At the time of continuous operation, they repeatedly adhere and separate, and become coarse particles mixed into the second classified powder. Also, these classifiers are not originally designed to classify such soft resins. Many are titanium oxides, which are inorganic substances,
Examples thereof include carbon ferrite, ceramics, alumina, clay, talc, calcium carbonate, and the like. The purpose is to classify a hard substance having no adhesive property such as an organic pigment as an organic substance. For this reason, when the soft resin is used, the formation of deposits in the classifier must be considered as a semi-inevitable obstacle. Accordingly, the present inventors have conducted intensive studies and have completed a method for producing a color toner free from defects.

The present invention is a first classification means in which a composition containing at least a binder or a dye or a pigment as a colorant is melt-kneaded, the kneaded material is cooled and solidified, and the solidified material is pulverized to produce a pulverized raw material. An inclined guide plate having a central portion higher at the upper part of the classifying chamber is provided, a supply groove is formed around the lower edge of the guide plate, and an inclined classifying plate having a central portion higher at the lower part of the classifying chamber. Is provided, a coarse powder discharge port for discharging coarse powder around the lower edge of the classifying plate is formed, and a fine powder discharge port for discharging fine powder is provided at the center of the classifying plate, It is introduced into a first classifier provided with a plurality of louvers for generating a swirling flow for classifying the coarsely pulverized raw material into fine powder and coarse powder around the lower edge of the classifying chamber, and After classification, the mixture is classified into fine powder and coarse powder, and the classified coarse powder is introduced into a pulverizing means and pulverized. The collected fine powder is separated into at least three by a classification edge, which is a separating means, which circulates to the mechanical means and collects the classified fine powder through a fine powder discharge pipe communicating with the fine powder discharge port. In the color toner production method of producing a color toner by introducing into a multi-division classification area and lowering it in a curved line by the Coanda effect to perform the second classification, the fine powder discharge port, the fine powder discharge pipe, the louver, The present invention relates to a method for producing a color toner, characterized in that a classification edge and at least a part of a discharge pipe connected to the classification edge are treated with a fluororesin.

The fluororesin used in the present invention is a resin containing at least fluorine in the main chain or side chain of the resin or in one segment. Examples of the monomer include tetrafluoroethylene, trifluorochloroethylene, vinyl fluoride, and fluorine. It is possible to use those obtained by polymerizing vinylidene fluoride, dichlorodifluoroethylene, hexafluoropropylene or the like alone or using two or more kinds.

In addition, it is also possible to use a copolymer composed of at least one fluorinated alkyl acrylate or fluorinated alkyl methacrylate and at least one of acrylate, methacrylate, acrylic acid, methacrylic acid, and styrene.

Incidentally, as the fluorinated alkyl acrylate or fluorinated alkyl methacrylate in the present invention,
Specifically, the following can be used.

That is, acrylic acid or methacrylic acid 1,1-dihydroperfluoroethyl, 1,1-dihydroperfluoropropyl, 1,1-dihydroperfluorohexyl, 1,1-dihydroperfluorooctyl, 1,1-dihydro Perfluorodecyl, 1,1-dihydroperfluorolauryl, 1,1,2,2-tetrahydroperfluorobutyl, 1,1,2,2-tetrahydroperfluorohexyl, 1,1,2,2-tetrahydroperfluoro Octyl, 1,1,2,2-tetrahydroperfluorodecyl,
1,1,2,2-tetrahydroperfluorolauryl, 1,1,2,2-
Tetrahydroperfluorostearyl, 2,2,3,3-tetrafluoropropyl, 2,2,3,3,4,4-hexafluorobutyl,
1,1, ω-trihydroperfluorohexyl, 1,1, ω-trihydroperfluorooctyl, 1,1,3,3,3-hexafluoro-2-propyl, 3-perfluorononyl-2-acetylpropyl , 3-perfluorolauryl-2-acetylpropyl, N-perfluorohexylsulfonyl-N-methylaminoethyl, N-perfluorohexylsulfonyl-N
-Butylaminoethyl, N-perfluorooctylsulfonyl-N-methylaminoethyl, N-perfluorooctylsulfonyl-N-methylaminoethyl, N-perfluorooctylsulfonyl-N-butylaminoethyl, N-
Perfluorodecylsulfonyl-N-methylaminoethyl, N-perfluorodecylsulfonyl-N-ethylaminoethyl, N-perfluorodecylsulfonyl-N-butylaminoethyl, N-perfluorolaurylsulfonyl-
N-methylaminoethyl, and the like.

As the binder resin for toner of the present invention, the following can be used, for example, polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene -Butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylate copolymer (styrene-methyl acrylate copolymer, styrene- Ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylic ester copolymer (styrene-methyl methacrylate) Copolymer, styrene-ethyl methacrylate copolymer, styrene Butyl methacrylate copolymer,
Styrene-phenyl methacrylate copolymer), styrene-α-methyl methyl acrylate copolymer, styrene-
Styrene-based resins such as acrylonitrile-acrylate copolymers (homopolymers or copolymers containing styrene or styrene substituents), vinyl chloride resins, styrene-vinyl acetate copolymers, rosin-modified maleic acid resins, phenolic resins , Epoxy resin, polyester resin, low molecular weight polyethylene, low molecular weight polypropylene, ionomer resin, polyurethane resin, silicone resin, ketone resin,
Examples include an ethylene-ethyl acrylate copolymer, a xylene resin, and a polyvinyl butyral resin. Particularly preferred resins in the practice of the present invention include styrene-acrylate resins and polyester resins.

In particular, (Wherein R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2
~ 10. A) a carboxylic acid component composed of a divalent or higher carboxylic acid or an acid anhydride thereof or a lower alkyl ester thereof, such as fumaric acid, maleic acid, maleic anhydride, phthalic acid A polyester resin obtained by at least co-condensation polymerization of an acid, terephthalic acid, trimellitic acid, pyromellitic acid and the like is particularly preferable because it has sharp melting characteristics.

The glass transition point of the binder resin is preferably 40 to 70 ° C.
The temperature is more preferably from 45 to 67 ° C and more preferably from 48 to 65 ° C. When the toner has a glass transition point of 40 ° C. or lower, the toner has a problem in storage stability and easily blocks. If the temperature is higher than 70 ° C., the fixability of the toner on the transfer support is deteriorated, and the toner is separated by simple rubbing by hand or the like.

As the coloring agent used, as the dye, for example, C.
I. Direct Red 1, CI Direct Red 4, CI
Acid Red 1, CI Basic Red 1, CI Modern Blue 30, CI Direct Blue 1, CI Direct Blue 2, CI Acid Blue 9, CI Acid Blue 15, CI Basic Blue 3, CI Basic Blue 5, CI Modern Blue 7, Etc.

As the pigment, naphthol yellow S, Hansa yellow G, permanent yellow NCG, permanent orange GTR, pyrazolone orange, benzidine orange G,
Permanent Red 4R, Watching Red Calcium Salt, Brilliant Carmine 3B, Fast Violet B, Methyl Violet Lake, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue BC
Etc.

Preferably, disazo yellow, insoluble azo and copper phthalocyanine are suitable as pigments, and basic dyes and oil-soluble dyes are suitable as dyes.

Particularly preferably, CI Pigment Yellow 17, CI Pigment Yellow 15, CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 12, CI
Pigment Red 5, CI Pigment Red 3, CI Pigment Red 2, CI Pigment Red 6, CI Pigment Red 7, CI Pigment Blue 15, CI Pigment Blue 16, or a copper phthalocyanine pigment having the structural formula (1) shown below. It is.

Dyes include CI Solvent Red 49, CI Solvent Red 52, CI Solvent Red 109, CI Basic Red 12, CI Basic Red 1, and CI Basic Red 3b.

In the present invention, when a raw material for a color toner is used as a raw material, it is essential that the toner has the following characteristics.

In order to have appropriate gloss and color mixing to enhance the quality of color copied images, and to maintain offset resistance to the fixing roll, the apparent viscosities at 90 ° C and 100 ° C must be
It must be in the range of 10 ⁴ to 10 ⁶ poise, 5 × 10 ^{3 to} 5 × 10 ⁵ poise. It is important that the viscosities at 90 ° C. and 100 ° C. are in the above-mentioned range, and it is not possible to satisfy both the color mixing property and the anti-offset property even above or below the range.

Also, it is necessary to use an MI value in the range of 2.5 to 12.0.

The measurement of the apparent viscosity measurement in the present invention is performed using a flow tester CFT-500 type (manufactured by Shimadzu Corporation). Sample is 6
Weigh about 1.0-1.5g of 0mesh pass product. This is pressed for 1 minute at a load of 100 kg / cm ² using a molding machine.

Perform a flow tester measurement at a temperature of about 20 to 30 ° C and a humidity of 30 to 70% RH to obtain a temperature-apparent viscosity curve. From the obtained smooth curve, the apparent viscosities at 90 ° C. and 100 ° C. are determined and are defined as the apparent viscosities for the temperature of the sample.

RATE TEMP 6.0 D / M (° C for 1 minute) SET TEMP 70.0 DEG (° C) MAX TEMP 200.0 DEG INTERVAL 3.0 DEG PREHEAT 300.0 SEC (seconds) LOAD 20.0 KGF (kg) DIE (DIA) 1.0 MM (mm) DIE (LENG) 1.0 MM PLUNGER 1.0 CM ² (cm ² ) The measurement of the MI measurement is performed using a melt indexer L203 type (manufactured by Takara Kogyo). The sample weighs about 5 g of toner. Put this in an extruder, set the temperature to 125 ° C, and 325g
, And preheat for 5 minutes, and then measure the extrusion amount for 2 minutes. This is converted to the amount of extrusion for 10 minutes.
MI value.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples.

Example As a toner formulation, the following formulating amounts of a coloring agent and a charge control agent were used based on 100 parts by weight of a polyester resin obtained by condensing propoxylated bisphenol and fumaric acid.

The production method is as follows: the above formulation amounts are sufficiently preliminarily mixed with a Henschel mixer, melt-kneaded at least twice with a three-roll mill, cooled, roughly ground to about 1-2 mm using a hammer mill, and then ground. And Then the seventh
Grinding and classification were performed according to the flowchart based on the figure.

As a pulverizing means, an I-type jet pulverizer (manufactured by Nippon Pneumatic) is used. As a first classifying means, a polytetrafluoroethylene treatment as shown in FIGS. A stainless steel classifying louver, which is a surface of a steel discharge pipe and an air inlet, is divided into two parts, and the second classifying means is a polytetrafluoroethylene treatment as shown in FIG. Classification was performed using a three-division classifier applied to the surface of the steel discharge pipe to obtain a cyan toner.

Here, the principle of the two-segment classifier will be briefly described with reference to FIGS. 3, 4, and 5. In the drawings, reference numeral 1 denotes a main casing, and 2 denotes a lower casing connected to a lower portion of the casing 1. In addition, a hopper 3 is provided at a lower portion thereof, and a classification chamber 4 is formed inside the main body casing 1. A guide tube 10 stands upright on the upper part of the main body casing 1, and a supply tube 9 is connected to an upper outer peripheral surface of the guide tube 10. An inclined guide plate 15 whose center becomes higher is attached to a lower portion in the guide tube 10, and an annular supply groove 11 is formed around the outer periphery of the lower edge of the guide plate 15.

Here, the diameter of the guide plate 15 is increased,
That is, the supply groove 11 is adjacent to the inner wall of the main casing 1 and is the outermost peripheral portion of the classifying chamber 4.

At the bottom of the classifying chamber 4, an inclined classifying plate 5 whose central portion is high is provided, and an annular coarse powder discharge groove 6 is formed around the outer periphery of the lower edge of the classifying plate 5. A fine powder discharge port 7 is formed in the portion.

An air inlet 8 is provided around the outer periphery of the lower peripheral wall of the classifying chamber 4, and the air inlet 8 is constituted by a gap of a plurality of blade-shaped classifying louvers 14 as shown in FIG. ing. The flow of the air introduced from the air inlet 8 is adjusted by the classification louver 14 so that the powder material descends while swirling into the classification chamber 4 in the swirling direction. Is accelerating.

Further, an air inlet is provided around the upper peripheral wall of the classifying chamber 4.
12 are provided. The means for forming the air inlet 12 is not limited. However, as an example, a means formed by a gap between a plurality of blade-shaped dispersion louvers 13 is illustrated here. FIG. 4 shows a cross-sectional view taken along the line II of FIG. 3. As shown in FIG. 4, the flow of air introduced from the air inlet falls while turning around the inside and outside of the guide cylinder 10. The dispersion louvers 13 adjust so that the powder material swirling into the classification chamber 4 from the annular supply groove 11 is ejected in the swirling direction.

The cross-sectional area of the air inlets 8 and 12, that is, the space between the classification louvers 14 and the space between the dispersion louvers 13, and the height of each louver are appropriately set.

An annular supply groove 11 which is concentrated by centrifugal force on the inner wall of the guide cylinder
The powder material swirling into the classifying chamber 4 is dispersed by the air flowing from the air inlet 12 in the upper part of the classifying chamber, and the swirling force is accelerated to be swirled and dropped to the lower part of the classifying chamber. In this method, the swirling speed is further accelerated by the air flowing from the air inlet 8 to classify the powder into coarse powder and fine powder efficiently, and the first classified powder is obtained through the fine powder discharge port.

The principle of the three-division classifier will be briefly described with reference to FIG. 6. The side wall has a shape indicated by 22, 23, 24, the lower wall has a shape indicated by 25, and the side wall 23 and the lower wall 25 is provided with knife edge type classification edges 17 and 18, respectively, and the classification zones 17 and 18 divide the classification zone into three. A Coanda block provided with a first classifying powder supply nozzle 16 which opens to the classifying chamber below the side wall 22 and which is bent downward with respect to the extension direction of the tangent at the bottom of the nozzle to draw an oblong arc.
26 will be provided. The classifying chamber upper wall 27 is provided with a knife-edge type inlet edge 19 in the lower direction of the classifying chamber, and further, at the upper part of the classifying chamber, there are provided air inlet pipes 14 and 15 opening to the classifying chamber. Also,
The intake pipes 14 and 15 are provided with first and second gas introduction adjusting means 20 and 21 such as dampers, and static pressure gauges 28 and 29, respectively. Classification Edge 17,
The positions of the inlet 18 and the inlet edge 19 differ depending on the kind of the raw material to be classified and the desired particle size. Further, discharge pipes 11, 12, and 13 that open into the room are provided on the bottom of the classifying chamber in correspondence with the respective dividing areas. The discharge pipes 11, 12, 13 may be provided with opening and closing means such as valve means, respectively.

The first classification powder supply nozzle 16 is composed of a right-angled cylinder and a pyramidal cylinder, and the ratio of the inner diameter of the right-angled cylinder to the inner diameter of the narrowest part of the pyramidal cylinder is 20: 1 to 1: 1, preferably Setting from 10: 1 to 2: 1 gives a good introduction speed.

The classification operation in the multi-division classification region configured as described above is performed, for example, as follows. That is, the discharge pipe 1
Depressurizing the classification area through at least one of 1,12,13,
The first classifying powder is supplied by a gas flow flowing through the first classifying powder supply nozzle 16 opening into the classification area by the reduced pressure.
Feed to the classification area via 16.

The supplied first classified powder is formed by the Coanda effect,
Due to the action of the Coanda block 26 and the action of the gas flowing in at that time, it moves in a curved line 30 and, depending on the size of each particle, large particles (coarse powder) are placed outside the air flow, that is, the classification edge 18. Outside, the middle particles (second class powder) are fractionated between classification edges 18 and 17, small particles (fine powder) are divided into fractions inside classification edge 17, large particles are for discharge From the pipe 11, intermediate particles are discharged from the discharge pipe 12, and small particles are discharged from the discharge pipe 13.

In this way, about 1000 kg of cyan toner is 30 kg / h
Treated with / H. Using a cyan toner having an average particle size of 8 μm obtained by the final classification process, a copy test was performed using a color electrophotographic apparatus having an OPC photosensitive drum as shown in FIG.

The obtained image was a good one that faithfully reproduced the original. Further, a 20,000-sheet printing durability test was carried out, but no granular transfer omission was observed, and it was preferable that the initial transfer was not changed.

50 g of this cyan toner was weighed, sieved with a 500 mesh sieve, and the amount of particles having a size of 30 μ or more remaining on the sieve was measured.

The apparent viscosities of the cyan toner at 90 ° C. and 100 ° C. were 1.2 × 10 ⁵ poise and 2.3 × 10 ⁴ poise, respectively, and the MI value was 4.5.

Comparative Example In FIG. 8, FIG. 9, FIG. 10, and FIG. 11, a toner was manufactured and image evaluation was performed in the same manner as in the example except that the fluororesin treatment was not performed.

Approximately 800 kg was processed at a speed of 30 kg / H, and 50 g of cyan toner was sampled every 2 hours, sieved with a 500-mesh sieve, and the amount of particles having a particle size of 30 μ or more was measured. No residue was found, but after 12 hours, a considerable amount of coarse powder was found on the sieve, leaving about 0.3 g.
At 20 hours, the amount of coarse powder was clearly higher than at 12 hours, and the residual amount on the sieve was extremely large at 0.78 g. When a copy test was carried out using the cyan toner 20 hours later in the same manner as in the example, a large number of white particles of about 100 μm to 500 μm which were transferred off appeared, which was unsightly and unfit for practical use.

[Effects of the Invention] According to the present invention, a color toner in which coarse powder is significantly reduced can be obtained. Images can be obtained.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an example of a conventional pulverization method, and FIG. 2 is a view showing a state between a photoconductor and a transfer support when coarse toner is mixed in a transfer step and when it is not mixed. FIG. 3 is a cross-sectional view of a two-divided classifier, FIG. 4 is a cross-sectional view of FIG.
FIG. 3 is a cross-sectional view taken along the line II-II of FIG. 3, FIG. 6 is a cross-sectional view of a three-piece classifier, FIG. 7 is a flowchart showing an outline of the present invention, and FIG. 2 with
FIG. 9 is an explanatory view of a split classifier, FIG. 9 shows a sectional view taken along the line II of FIG. 8, FIG. 10 shows a sectional view taken along the line II-II of FIG.
FIG. 11 is an explanatory view of a three-division classifier subjected to a fluororesin treatment, and FIG. 12 is a view showing an example of a color electrophotographic apparatus having an OPC photosensitive drum.

────────────────────────────────────────────────── ─── front page continued (51) Int.Cl. ⁶ identifications FI G03G 9/09 G03G 9/08 361 (56 ) reference JP Akira 64-84259 (JP, a) JP Akira 63-197962 ( JP, A) JP-A-55-17945 (JP, A) JP-A-61-153179 (JP, A) JP-A-61-213858 (JP, A) JP-A-61-61627 (JP, A) JP-A-63-58356 (JP, A) JP-A-63-301960 (JP, A) JP-A-61-213858 (JP, A) JP-A-62-179045 (JP, U) JP-A-57-20298 (JP, A) , Y2) (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 9/08

Claims (3)

(57) [Claims] 1. A composition containing at least a binder resin and a dye or a pigment as a colorant is melt-kneaded, the kneaded product is cooled and solidified, and the solidified product is pulverized to produce a pulverized raw material. An inclined guide plate whose central part is raised is provided at the upper part of a certain classifying chamber, a supply groove is formed around the lower edge of the guide plate, and an inclined classifier whose central part is raised is formed at the lower part of the classifying chamber. A plate is provided, and a coarse powder discharge port for discharging coarse powder is formed around an outer periphery of a lower edge of the classifying plate, and a fine powder discharge port for discharging fine powder is provided at a central portion of the classifying plate. And introducing the raw material into a first classifier provided with a plurality of louvers for generating a swirling flow for classifying the coarsely crushed raw material into fine powder and coarse powder around the lower edge of the classification chamber. And classified into a fine powder and a coarse powder. The classified coarse powder is introduced into a pulverizing means and pulverized. Circulating to the classifier means, and collecting the classified fine powder through a fine powder discharge pipe communicating with the fine powder discharge port. The collected fine powder is fractionated into at least three by a classification edge which is a fractionating means. In the color toner production method of producing a color toner by introducing into a multi-divided classification area and descending in a curved line by the Coanda effect to perform the second classification, the fine powder discharge port, the fine powder discharge pipe, the louver, A method for producing a color toner, characterized in that at least a part of the classification edge and a discharge pipe connected to the classification edge are treated with a fluororesin. 2. The method according to claim 1, wherein the glass transition point of the binder resin is in the range of 40 to 70 ° C. 3. The color toner has an apparent viscosity at 90 ° C. and 100 ° C. of 10 ⁴ to 10 ⁶ poise and 5 × 10 ^{3 to} 5 × 10 ⁵ poise, respectively, and an MI value of 2.5 to 12.0. A certain claim (1)
The method for producing a color toner according to the above.