JP4671948B2 - Toner production method - Google Patents

Description

  The present invention relates to a method for producing toner used for electrophotography and the like, and a toner material kneading apparatus used therefor.

  In a method for producing toner used for electrophotography, a toner material mixture containing a binder resin, a colorant, and the like is continuously supplied between a pair of rotating rolls, and the toner is melted between the rolls while the toner is melted. While kneading the material mixture, there is one provided with a kneading step in which the resin kneaded material is wound around one roll and sent continuously in the roll length direction.

  Here, as a method of supplying the toner material mixture between the pair of rolls, there are a method using a screw type material supply machine and a method using a vibration type material supply machine.

  Patent Document 1 discloses a method using a screw type material feeder.

Patent Document 2 discloses both a method using a screw-type material supply machine and a method using a vibration-type material supply machine.
JP 2002-244347 A WO00 / 52533

  However, in the method of quantitatively supplying the toner material mixture using the screw-type material supply machine, the toner material mixture can be quantitatively supplied, but the toner material mixture is concentrated at a specific location on the roll. Since the toner is supplied, there is a problem that the binder resin is insufficiently melted and the toner material mixture is spilled or peeled off from the roll.

  In addition, the method of supplying the toner material mixture by diffusing the toner material widely in the trough using a vibrating material supply machine can supply a uniform toner material mixture between the rolls, but quantitatively supplies the toner material mixture. There is a problem that there is anxiety in terms of doing.

  An object of the present invention is to provide a toner manufacturing method and a toner material kneading apparatus used therefor, which can supply a quantitative and uniform toner material mixture between rolls.

The method for producing a toner according to the present invention that achieves the above object includes a binder resin disposed between a pair of rolls that are arranged substantially horizontally at predetermined intervals and each rotate inward from top to bottom. A kneading step of continuously supplying a toner material mixture containing a resin material, winding the resin kneaded material around one roll while continuously kneading the toner material mixture between the pair of rolls, and continuously collecting the resin kneaded material in a roll length direction With
The supply of the toner material mixture between the pair of rolls in the kneading step is performed using a trough that is inclined so that one end is positioned above the pair of rolls and extends obliquely upward toward the other end, A constant amount of the toner material mixture is continuously supplied to the other end of the trough per unit time, and the trough is vibrated to diffuse the toner material mixture in the width direction of the trough, thereby causing the trough to be inclined. This is done by moving it forward diagonally downward.

The toner material kneading apparatus according to the present invention includes a pair of rolls arranged substantially horizontally at a predetermined interval, and each of the pair of rolls rotates inward from top to bottom, When a toner material mixture containing a binder resin is continuously supplied between a pair of rolls, the resin kneaded material is wound around one roll while kneading the toner material mixture between the pair of rolls and roll length To send in the direction,
A trough provided with one end positioned above the pair of rolls and inclined so as to extend obliquely upward toward the other end;
A quantitative material supply means for continuously supplying a constant amount of toner material mixture per unit time to the other end of the trough;
Vibration applying means for applying vibration to the trough so that the toner material mixture supplied to the trough from the quantitative material supplying means diffuses in the width direction of the trough;
Is further provided.

  According to the present invention, the toner material mixture is continuously supplied quantitatively to the trough provided at an inclination, and the trough is imparted with vibrations, so that the toner material mixture retains its quantitative property while maintaining the quantitative property. In the state of being uniformly diffused in the width direction of the trough, it is conveyed along the inclination of the trough and supplied between the rolls. That is, a quantitative and uniform toner material mixture can be supplied between the rolls.

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

(Embodiment 1)
<Toner material kneading device>
1 and 2 show an open roll type toner material kneading apparatus A according to this embodiment.

  The toner material kneading apparatus A includes a front roll 11 and a back roll 12 that are arranged substantially horizontally at a predetermined interval.

  Each of the front roll 11 and the back roll 12 is generally made of metal. For example, the roll outer diameter of the roll body that is a cylindrical portion is 100 to 500 mm, and the roll length is 3 to 7 times the roll outer diameter. Is formed. Each of the front roll 11 and the back roll 12 may be one in which the roll surface is formed flat or may be one in which a number of helical tooth-like linear grooves are formed.

  Each of the front roll 11 and the back roll 12 is supported so that the shaft portions at both ends of the roll body can be rotated by bearings, and a drive motor is attached to the shaft portion at one end. The drive motor is connected to a control unit, and the rotation direction and the number of rotations of the front roll 11 or the back roll 12 can be freely set by operating the control unit. Further, each of the front roll 11 and the back roll 12 has both bearings movable in the front-rear direction, and the clearance between the front roll 11 and the back roll 12 can be freely set by positioning the bearings. It can be done. Furthermore, each of the front roll 11 and the back roll 12 is provided with a temperature setting mechanism by circulating a heat medium or a refrigerant. The temperature setting mechanism is connected to the control unit, and the temperature of the roll surface can be freely set by operating the control unit. The roll around which the toner material kneaded material is wound is used as the front roll 11, and the surface temperature of the front roll 11 is set higher than that of the back roll 12.

  Further, the toner material kneading apparatus A includes a toner material supply unit 20 provided at one end side of the front roll 11 and the back roll 12 and behind the back roll 12 side.

  The toner material supply unit 20 includes a material mixer (not shown), and a quantitative material supply device 210 and a vibration material supply device 220 that are provided vertically above and behind the front roll 11 and the back roll 12.

  The material mixer has a material mixing mechanism for mixing the toner material and a material conveying mechanism for conveying the mixed toner material mixture, but they are not particularly limited. Each of the material mixing mechanism and the material transport mechanism is connected to a control unit, and the operation of the control unit mixes the supplied toner material and transports the mixed toner material mixture to the quantitative material feeder 210. It is like that.

  The quantitative material feeder 210 includes a subtractive screw feeder having an upper material tank 211 and a feeder main body 212 provided therebelow. The quantitative material feeder 210 is not particularly limited to a subtractive screw feeder.

  The material tank 211 is connected to the material mixer via a pipe. The feeder main body 212 includes a casing 213 formed so as to protrude forward, a pair of screws 214 provided in parallel therewith, and a drive motor that rotationally drives them. An opening is formed in the casing 213 on the lower surface side of the front end portion, and a cylindrical cover member 215 formed so as to cover the opening and extend downward is attached.

  The quantitative material feeder 210 includes an opening / closing mechanism that opens and closes a communication structure between the material tank 211 and the feeder body 212 and a load cell that measures the weight of the toner material mixture discharged from the material tank 211 to the feeder body 212. Is provided. Each of the opening / closing mechanism, the load cell, and the drive motor of the screw 214 is connected to a control unit. By the operation of the control unit, the material tank 211 to the feeder main body 212 and the opening of the feeder main body 212 per unit time. The desired amount of the toner material mixture can be quantitatively supplied. Specifically, it is possible to achieve quantitativeness within an error range of ± 3% in the order of supplying 15 kg per minute.

  The vibratory material supply machine 220 has a trough 221 provided at one end positioned above the rolls of the front roll 11 and the back roll 12 and inclined to extend rearward and upward toward the other end and the other end. And a vibrator 226 attached to the side via a bracket 225. The trough 221 and the vibrator 226 are fixedly attached to the support base 227.

  The trough 221 is generally made of metal, and as shown in FIG. 3, a trough body 222 having a U-shaped cross-section that opens at one end and opens upward, and a lid that closes the opening above the trough body 221. For example, it is formed in a long and wide cylindrical shape having a horizontal cross-sectional shape of a cross section having a length of 200 to 1500 mm, a width of 50 to 300 mm, and a thickness of 20 to 150 mm.

  The trough main body 222 has a bottom surface portion, side surface portions that are continuous with the bottom surface portion, a rear surface portion, and a flange that extends outwardly continuously from the respective upper ends thereof. The U-shaped groove formed inside the trough body 222 has a flat bottom surface 222a formed by the top surface of the bottom surface portion. The width W of one end (opening end) of the bottom surface 222a is, for example, 50 to 300 mm, and preferably 0.075 to 0.5 times the roll length L of the front roll 11 and the back roll 12. Further, the bottom surface 222a may be formed with a constant width along the length direction, or may be formed so as to increase in width from one end to the other end, or from one end to the other end. And may be formed to be narrow. The lid member 223 is provided so as to abut against the flange of the trough body 222 and is bolted, and a cylindrical member 224 extending upward is attached to the other end of the lid member 223, and this cylindrical member 224 is coupled to a cover member 215 attached to the feeder body 212 of the quantitative material feeder 210.

  One end of the trough 221 is above the front roll 11 side between the front roll 11 and the back roll 12, specifically, φ = 15 to 60 from the closest position of the front roll 11 to the back roll 12. It is preferable that the distance from the front roll 11 is positioned in the range of 5 to 200 mm in the range of °.

  The vibrator 226 is configured to apply vibration in the width direction to the trough 221 via the bracket 225. The vibrator 226 is connected to a control unit, and the amplitude and frequency of vibration applied to the trough 221 can be freely set by operating the control unit.

  Further, the toner material kneading apparatus A is provided with a resin kneaded material recovery unit including a cutter and a resin kneaded material transporter provided at the other end of the front roll 11 so as to be in contact with the front roll 11.

  In addition, the toner material kneading apparatus A may be provided with a belt conveyance unit for returning the falling material onto the roll by the conveyance belt on one end side in the roll length direction of the front roll 11 and the back roll 12. Good.

<Toner production method>
Next, a toner manufacturing method using the toner material kneading apparatus A will be described.

-Setting process-
Setting of the toner material kneading apparatus A is performed.

  Specifically, the interval between the front roll 11 and the back roll 12 is set. This interval is preferably set to 0.1 to 10 mm, and more preferably set to 0.1 to 3 mm. In addition, the space | interval of the front roll 11 and the back roll 12 does not necessarily need to be constant in the roll length direction.

  Each rotation direction and rotation speed are set so that both the front roll 11 and the back roll 12 rotate inward from top to bottom at a predetermined rotation speed. The former rotational speed is preferably set to 60 to 100 rpm, and more preferably set to 60 to 80 rpm. The latter rotational speed is preferably set to 20 to 60 rpm, and more preferably set to 40 to 50 rpm. In order to wind the resin kneaded material R around the former, the number of rotations of the front roll 11 / the number of rotations of the back roll 12 = 10/9 to 10/1 is set higher than the former.

  The temperature of each roll surface of the front roll 11 and the back roll 12 is set to a predetermined temperature. The former temperature is preferably set to 100 to 180 ° C., more preferably 100 to 150 ° C., depending on the configuration of the toner material. The latter temperature is preferably set to 20 to 95 ° C, more preferably 30 to 85 ° C. In order to wind the resin kneaded product R around the former, the former temperature is set higher than the latter.

  For the material kneader of the toner material supply unit 20, the kneading conditions of the material kneading mechanism and the conveying conditions of the material conveying mechanism are set to predetermined ones.

With respect to the quantitative material supply unit of the toner material supply unit 20, the material tank 211 to the feeder body 212 and the feeder body 212 from the opening of the feeder body 212 depending on the setting conditions of the interlocking condition of the load cell and the opening / closing mechanism and the rotation speed of the screw 214. The supply amount of the toner material mixture per unit time is set. The supply amount F (kg / h) of the toner material mixture is preferably set so as to be proportional to the nth power of the roll diameter D (m) of the front roll 11 as shown by the following equation (1).
F = k · D ⁿ (1) and (1), k = 1500 and n = 2 to 3.

  For the vibration material supply unit of the toner material supply unit 20, the amplitude and frequency of the vibrator 226 of the vibration material supply unit are set so that the toner material mixture is diffused in the width direction on the trough 221. Specifically, for example, it is preferable to set the amplitude to 1 to 5 mm and the frequency to 10 to 80 Hz. More preferably, the amplitude is set to 1 to 3 mm and the frequency is set to 50 to 60 Hz.

-Kneading process-
(1) Each part of the toner material kneading apparatus A is operated, and the measured toner materials such as a binder resin, a colorant and a release agent are put into a material mixer. In the material mixer, the toner materials are mixed by the material mixing mechanism, and the mixed powder aggregated toner material mixture is conveyed to the quantitative material feeder 210 by the material conveying mechanism.

  Here, examples of the binder resin include polyester resin, styrene-acrylic resin, epoxy resin, polycarbonate resin, polyurethane resin, and the like. And 1 type (s) or 2 or more types are used as binder resin.

  As the crystalline polyester, for example, an alcohol component containing 80 mol% or more of an aliphatic diol having 2 to 6 carbon atoms (preferably 4 to 6 carbon atoms) and 2 to 8 carbon atoms (preferably 4 to 6 carbon atoms are more preferable. (4) includes a resin obtained by polycondensation with a carboxylic acid component containing 80 mol% or more of the aliphatic dicarboxylic acid compound of 4). “Crystallinity” in the present application means that the ratio (softening point / peak temperature) between the softening point and the maximum peak temperature of heat of fusion is 0.9 or more and less than 1.1.

  Examples of the colorant include dyes and pigments used as a colorant for toner. Examples thereof include carbon black, phthalocyanine blue, permanent brown FG, priestly first scarlet, pigment green B, rhodamine-B base, and solvent red 49. Solvent Red 146, Solvent Blue 35, Quinacridone, Carmine 6B, Disazo Yellow and the like. And as a coloring agent, 1 type (s) or 2 or more types are used among these. The blending amount of the colorant is preferably 1 to 15 parts by mass and more preferably 2 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

  Examples of release agents include natural waxes such as carnauba wax and rice wax, synthetic waxes such as polypropylene wax, polyethylene wax, and Fischer Tropu, coal-based waxes such as montan wax, alcohol-based waxes, ester-based waxes, and the like. It is done. And as a wax, 1 type (s) or 2 or more types are used among these. The blending amount of the wax is preferably 1 to 15 parts by mass and more preferably 2 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

  Other toner materials include charge control agents, fluidity improvers, conductivity modifiers, extender pigments, reinforcing fillers such as fibrous substances, antioxidants, anti-aging agents, cleaning improvers, etc. May be contained as appropriate. In addition, the toner material includes classified powder to which silica or the like generated in a later step is attached, and the toner material may be composed only of classified powder.

  (2) In the quantitative material supply unit 210, the toner material mixture from the material mixer is supplied to the material tank 211 via a pipe. In the quantitative material feeder 210, a constant amount of the toner material mixture per unit time is continuously supplied from the material tank 211 to the feeder body 212 by the interlocking of the load cell and the opening / closing mechanism. It is fed and dropped from the opening of the feeder main body 212 and continuously supplied to the vibration type material feeder 220 through the cover member 215. At this time, the quantitativeness is maintained both in the supply of the toner material mixture from the material tank 211 to the feeder body 212 and in the transport of the toner material mixture in the feeder body 212.

  (3) The toner material mixture from the quantitative material feeder 210 is continuously supplied to the other end portion of the trough 221 through the cylindrical member 224 to the vibration material feeder 220. In the vibratory material feeder 220, the toner material mixture supplied quantitatively continuously diffuses in the width direction on the bottom surface 222a of the trough body 222 to which vibration is applied by the vibrator 226 and feeds the material by the inclination of the bottom surface 222a. Then, it falls from the open end of the trough 221 and is continuously supplied between the rolls of the front roll 11 and the back roll 12 while maintaining quantitativeness.

  By continuously supplying the toner material mixture quantitatively to the trough 221 provided in this manner and applying vibration to the trough 221, the toner material mixture retains its quantitativeness, In a state of being uniformly diffused in the width direction of the trough 221, it is conveyed along the inclination of the trough 221 and supplied between the rolls of the front roll 11 and the back roll 12. That is, a quantitative and uniform toner material mixture can be supplied between the front roll 11 and the back roll 12.

  At this time, from the viewpoint of appropriately diffusing the toner material mixture in the width direction of the trough 221, suppressing the material feed due to vibration, and feeding the material by tilt while maintaining quantitativeness, the tilt angle of the trough 221 is θ = 10 to 50 ° is preferable, and θ = 20 to 40 ° is more preferable.

  Further, in order to efficiently apply the heat amount from the front roll 11 and the back roll 12 to the toner material mixture, the trough body 222 (bottom face 222a) is preferably formed to have a constant width along the length direction. .

  (4) The toner material mixture from the quantitative material feeder 210 is continuously and quantitatively supplied to the front roll 11 and the back roll 12 between the rolls uniformly in the width direction. In the front roll 11 and the back roll 12, the resin component of the toner material mixture melts and is kneaded with other toner materials to form a viscoelastic resin kneaded product R, which is wound around the front roll 11 and is from one end side. It is sent continuously toward the other end side.

  At this time, in order to supply the toner material mixture by diffusing widely while maintaining the quantitative property of the toner material mixture, the supply width of the toner material mixture between the rolls of the front roll 11 and the back roll 12 (at one end of the bottom surface 222a of the trough 222). The width W) is preferably 0.075 to 0.5 times the roll length L.

  (5) At the other end of the front roll 11, the resin kneaded material R that is continuously fed is continuously cut out and collected in a narrow band shape in the circumferential direction by a cutter, and the band-shaped resin kneaded material R is the resin kneaded material. It is conveyed to a cooler by a conveyance machine.

-Production process-
The strip-shaped resin kneaded product R collected as described above is crushed and classified, and then subjected to surface treatment with silica or the like, and after passing through a sieve, the case is filled into a toner cartridge such as a copying machine. It is said.

(Embodiment 2)
<Toner material kneading device>
FIG. 4 shows a toner material kneading apparatus A according to the second embodiment. In addition, the part of the same name as Embodiment 1 is shown with the same code | symbol as Embodiment 1. FIG.

  The toner material kneading apparatus A includes a first toner material supply unit 20 corresponding to the toner material supply unit 20 in the first embodiment and a second toner material supply unit 20 ′ provided on the side thereof.

  The first and second toner material supply units 20, 20 'have the same configuration.

  Other configurations are the same as those of the first embodiment.

<Toner production method>
In the toner manufacturing method using the toner material kneading apparatus A, the toner material supplied from the second toner material supply unit 20 ′ is formed by the toner material mixture supplied from the first toner material supply unit 20. The resin kneaded material R is formed in a form in which the mixture is added.

  Therefore, in the toner manufacturing method using the toner material kneading apparatus A, the same toner material mixture can be supplied from the first and second toner material supply units 20 and 20 '. At this time, the supply amount of the toner material mixture from each of the first and second toner material supply units 20 and 20 'per unit time may be the same or different.

  Further, in the toner manufacturing method using the toner material kneading apparatus A, different toner materials can be supplied from the first and second toner material supply units 20 and 20 '.

  For example, only a part of the toner material including the binder resin can be supplied from the first toner material supply unit 20, and the remaining toner material can be supplied from the second toner material supply unit 20 '. The first toner material supply unit 20 can supply a toner material mixture made only of a novel toner material containing a binder resin, and the second toner material supply unit 20 'can supply only classified powder. In this way, the classified powder can be directly added to the resin kneaded product R and regenerated without being mixed with a new toner material containing a binder resin or the like.

Example 1
Using the toner material kneading apparatus A having the same configuration as that of the first embodiment, the toner material of the basic composition was charged into a material mixer to prepare a resin kneaded product R. Each of the front roll 11 and the back roll 12 had a roll diameter of 320 mm and a roll length of 1800 mm. The width of the bottom surface 222a of the trough body 222, that is, the supply width of the toner material mixture between the rolls of the front roll 11 and the back roll 12, was 200 mm, which was 0.111 times the roll length. The inclination angle of the trough was 30 °. Further, the quantitative material feeder 210 was set so that the supply amount of the toner material mixture was 80 kg / h.

  At this time, the toner material mixture is supplied between the rolls of the front roll 11 and the back roll 12 uniformly and continuously in the width direction. As a result, the resin kneaded material R is not peeled off from the front roll 11 and spilled. The amount was only about 1%.

(Example 2)
Using a toner material kneading apparatus A having the same configuration as that of the second embodiment, a toner kneaded material R was prepared by charging a toner material having a basic composition into a material mixer. Each of the front roll 11 and the back roll 12 had a roll diameter of 320 mm and a roll length of 1800 mm. The width of the bottom surface 222a of the trough body 222, that is, the supply width of the toner material mixture between the rolls of the front roll 11 and the back roll 12, was 150 mm, which was 0.083 times the roll length. The inclination angle of any trough 221 of the first and second toner material supply units 20, 20 ′ was 30 °. Further, the quantitative material supply unit 210 of the first toner material supply unit 20 is set so that the supply amount of the toner material mixture is 60 kg / h, and the supply amount of the toner material mixture containing only classified powder is 20 kg / h. Thus, the quantitative material supply unit 210 of the second toner material supply unit 20 ′ was set.

  At this time, the toner material mixture is supplied between the rolls of the front roll 11 and the back roll 12 uniformly and continuously in the width direction. As a result, the resin kneaded material R is not peeled off from the front roll 11 and spilled. The amount was only about 1%. There was almost no spillage of fine powder from the second toner material supply unit 20 '.

(Comparative Example 1)
FIG. 5 shows the toner material kneading apparatus A used in Comparative Example 1. In addition, the part of the same name as Embodiment 1 is shown with the same code | symbol as Embodiment 1. FIG.

  In this toner material kneading apparatus A, the vibration material supply machine 220 is removed from the toner material kneading apparatus A used in the first embodiment, and the toner material is directly between the front roll 11 and the back roll 12 from the quantitative material supply machine 210. A mixture is supplied. The supply width of the toner material mixture between the front roll 11 and the back roll 12 was 30 mm, which was 0.017 times the roll length.

  Using this toner material kneading apparatus A, an attempt was made to produce a resin kneaded material in the same manner as in the examples.

  At this time, since the toner material mixture was supplied in a concentrated manner at the supply position, peeling from the front roll 11 occurred, and therefore the operation of the toner material kneading apparatus A was stopped.

(Comparative Example 2)
FIG. 6 shows the toner material kneading apparatus A used in Comparative Example 2. In addition, the part of the same name as Embodiment 1 is shown with the same code | symbol as Embodiment 1. FIG.

  In this toner material kneading apparatus A, the quantitative material feeder 210 is removed from the toner material kneading apparatus A of Example 1, the material mixer is directly connected to the vibrating material feeder 220, and the trough 221 is provided horizontally. is there.

  Using this toner material kneading apparatus A, a resin kneaded product R was produced in the same manner as in the example. The vibratory material feeder 220 was set so that the supply amount of the toner material mixture was approximately 100 kg / h.

  At this time, the toner material mixture was supplied uniformly between the front roll 11 and the back roll 12 in the width direction, but the supply of the toner material mixture became intermittent.

  INDUSTRIAL APPLICABILITY The present invention is useful for a method for producing toner used for electrophotography and the like and a toner material kneading apparatus used therefor.

3 is a front view of the toner material kneading apparatus according to Embodiment 1. FIG. 3 is a right side view of the toner material kneading apparatus according to Embodiment 1. FIG. It is a perspective view of a trough. 6 is a front view of a toner material kneading apparatus according to Embodiment 2. FIG. 6 is a front view of a toner material kneading apparatus of Comparative Example 1. FIG. 6 is a front view of a toner material kneading apparatus of Comparative Example 2. FIG.

Explanation of symbols

A Toner material kneading device 11 Front roll 12 Back roll 210 Quantitative material feeder 220 Vibrating material feeder 221 Trough 222a Bottom

Claims (6)

A toner material mixture containing a binder resin is continuously supplied between a pair of rolls that are arranged substantially horizontally at a predetermined interval, each rotating inward from top to bottom, and the pair of rolls A method for producing a toner comprising a kneading step in which the resin kneaded material is wound around one roll and continuously collected while being kneaded with the toner material mixture.
The supply of the toner material mixture between the pair of rolls in the kneading step is performed using a trough that is inclined so that one end is positioned above the pair of rolls and extends obliquely upward toward the other end, A constant amount of the toner material mixture is continuously supplied to the other end of the trough per unit time, and the trough is vibrated at an amplitude of 1 to 5 mm and a frequency of 10 to 80 Hz, thereby causing the toner material mixture to move in the width direction of the trough. is diffused, it had lines by forwarding obliquely downward along the inclination of the trough,
The trough has a flat surface with an inclination angle of 10 to 50 °, which is provided from the other end to one end, and feeds the toner material mixture continuously supplied from the other end to the opening at one end. The opening width is 50-300 mm,
The roll diameter D of the one roll is 0.1 to 0.5 m, and the supply amount of the toner material mixture from the trough to the pair of rolls in the kneading step is 1500 · D ³ to 1500 · D ² kg / h. A method for producing toner.   The toner manufacturing method according to claim 1, wherein the trough is formed with a constant width along the length direction.   The toner manufacturing method according to claim 1, wherein the continuous supply of the toner material mixture to the trough is performed by a subtractive quantitative material supply machine.   The method for producing toner according to claim 1, wherein a supply width of the toner material mixture between the pair of rolls in the kneading step is set to 0.075 to 0.5 times the roll length of the pair of rolls.   The toner manufacturing method according to claim 1, wherein the toner material mixture is supplied to a plurality of locations between the pair of rolls in the kneading step. 6. The method for producing toner according to claim 5 , wherein only the classified powder is supplied as the toner material mixture in at least one of the supply of the toner material mixture between the pair of rolls at the plurality of locations.

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