JPH07287420A - Production of toner - Google Patents

Abstract

PURPOSE:To provide a process for producing a toner capable of omitting a premixing stage as a process for producing the toner including a melt kneading stage using a twin-screw extruder and to provide a toner which is good in dispersion of coloring agent and release agent in a binder resin, is stable in electrostatic chargeability, is free from fogging and does not generate excessive cutting of molecular chains in a kneading stage. CONSTITUTION:The twin-screw extruder in the process for producing the toner having the stage for kneading at least the binder resin and the coloring agent by using the twin-screw extruder has at least two points of raw material supply ports 4, 6 in a barrel length direction. A compsn. which contains at least the binder resin (or the binder resin and the release agent) and has a static bulk density of 0.30 to 0.70g/ml is supplied from the first raw material supply port 4 disposed on the extreme upstream side of the twin-screw extruder. A compsn. which contains at least the coloring agent and has a static bulk density of 0.02 to 0.30g/ml is supplied from the raw material supply port 6 disposed on the down stream side of the first raw material supply port 4 of the twin-screw extruder. Both compsns. are then kneaded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic latent image developing toner used in electrophotography, electrostatic recording, electrostatic printing and the like, and more particularly to a method for producing the same.

[0002]

2. Description of the Related Art In electrophotography, an electrostatic latent image is usually formed on a latent electrostatic image bearing member made of a photoconductive photosensitive member by charging and exposure, and then the electrostatic latent image is formed into a binder resin (condensed). The toner image is developed with a toner formed by adding a coloring agent or the like to a fine particle form, and the obtained toner image is transferred and fixed on a support such as transfer paper to form a visible image. On the other hand, the photoconductor is subjected to charge removal after transfer, and then the toner remaining on the photoconductor without being transferred is cleaned and then used for forming the next image. The electrophotographic toner used for forming such a toner image is generally composed of a binder resin in which a colorant is dispersed and contained. As the colorant, carbon black is used for the toner used for forming a black image. Various chromatic dyes and pigments are used for the color toner used for forming a color image.

Conventionally, the manufacturing process of the electrophotographic toner excluding the polymerized toner synthesized in one shot by the polymerization reaction is a premixing process of premixing a colorant, a binder resin, a release agent and other additives.

A melt-kneading step of kneading the preliminary mixture obtained above.

A pulverization / classification step in which the melt-kneaded material obtained in the above-mentioned melt-kneading step is pulverized to a desired toner particle size and classified.

It consists of three steps. In order to maintain various properties and qualities required for the toner, it is particularly required in the toner manufacturing process to improve the dispersibility of the additive in the binder resin and optimize the molecular chain scission ratio of the binder resin. In order to improve the dispersibility of the additive in the binder resin, a method of changing the operating conditions of the mixer in the premixing step and the operating conditions of the kneader in the kneading step has been attempted. Particularly in color toners, since the wettability of the dye and pigment is poor, first, a pulverized product of a kneaded product of a part of the resin and a part or all of the dye and the remaining resin and the dye and pigment are mixed, and then kneaded again. Kneading by the masterbatch method is widely applied.

For example, in (1) JP-A-54-118250, a magnetic material is kneaded with a resin having a low melting point or a brittle resin, and then a resin having a higher melting point than the resin is kneaded at a temperature equal to or higher than the melting point of the high melting point resin. A method of manufacturing a magnetic toner has been proposed.
(2) In JP-A-2-66561, the weight average molecular weight Mw is 10
A master batch method of melt-kneading, pulverizing and classifying a processing raw material obtained by melt-kneading more than ten thousand binder resins and pigments and a pigment resin having a smaller Mw than the binder resin, and other toner components. A method of manufacturing the applied color toner has been proposed. (3) In Japanese Patent Laid-Open No. 3-149567, from the viewpoint of improving production efficiency, the two kneading steps, which are the drawbacks of the masterbatch method, are performed once and from the inlet side of the barrel (length L) of the kneader. A mixed material containing 10 to 50% by weight of the additive in the resin is supplied from a supply port provided within a position of 0.3 L,
A manufacturing method has been proposed in which a mixed raw material having an additive amount of 20% by weight or less in a resin is supplied from a supply port provided at a position of L to 0.9 L and simultaneously taken out from a discharge port. (4) JP-A-3-86
In No. 224 publication, in the kneading machine screw design, the kneading paddle is divided into a feed screw and a kneading part,
It is proposed to have two or more kneading paddles and design the length of the kneading paddle on the discharge side to be 20% or more and 50% or less with respect to the entire length of the paddle.

[0008]

[Problems to be Solved by the Invention]
In the technique described in (1), in order to satisfy the contradictory conditions of reliable exposure of the magnetic material on the toner surface and improvement of fixing property at the same time, two kneading steps are indispensable and the production efficiency is lowered. have. The technique described in (2) above is based on the premise that a masterbatch pigment is used, although it has the advantages of excellent color development and light resistance as a color toner, and that pigment release does not easily occur. And the resin for masterbatch becomes non-uniform, and when it is used as a toner, the charge distribution is widened and fogging occurs on the image.
Even when the masterbatch resin and the binder resin are of the same type, the number of times of kneading is different between the resins, and the molecular chain scission of the masterbatch resin progresses excessively, and a high temperature offset phenomenon is likely to occur during fixing. In the technique described in (3) above, although the number of times of toner kneading is once to improve the production efficiency, a difference occurs in the shearing force received during the kneading between the resin forming the masterbatch and the rest of the resin, so that stable fixing is achieved. It is difficult to secure performance. In the technique described in (4) above, the dye / pigment and the charge control agent are uniformly dispersed in the binder resin because they pass through the kneading zone twice, but since the kneading zone on the discharge side is long, the zone The kneaded material stays inside and receives excessive shearing force, and the temperature rises due to frictional heat, which makes temperature control difficult, and at the same time molecular chains of the binder resin, which is the main component, are broken, stabilizing production and fixing toner. It had a defect in terms of stabilizing the performance. The present inventors ensured good dispersibility of the toner internal additive and simplified the toner manufacturing process,
From the viewpoint of labor saving, if the uniformity of the internal additive in the binder resin can be ensured by devising the method of supplying each toner composition in the melt-kneading step of the toner manufacturing step, the pre-mixing step is omitted. Considering that it is possible, after paying attention to the particle size difference of the toner composition, that is, the static bulk density, which is an obstacle to achieving the uniformity of the toner internal additive, after melting the main raw material resin having a high static bulk density in advance. It was found that if a colorant having a low static bulk density was sequentially fed to the main raw material that was melted, it was possible to easily knead the colorant and the like into the binder resin, and as a result of diligent study, in the melt kneading step, kneading was performed. As a machine, a twin-screw extruder having a plurality of raw material supply ports along the length direction of the barrel is used, and a static bulk density containing at least a binder resin (or a binder resin and a release agent) is 0.30 to 0.70 g.
/ Ml of the composition is supplied from the first raw material supply port provided on the most upstream side of the twin-screw extruder, and the composition having at least a static bulk density of 0.02 to 0.30 g / ml of a colorant is supplied to the extruder. By supplying and kneading from at least one raw material supply port provided on the downstream side of the first raw material supply port of
The inventors have found that even if the above premixing step is omitted, the uniformity of dispersion of the colorant, the release agent, the binder resin, etc. in the toner is not impaired, and the present invention has been completed.

An object of the present invention is to provide a toner manufacturing method including a melt-kneading step using a twin-screw extruder,
(EN) To provide a method for producing a toner capable of omitting a premixing step, and to supply a toner produced by using the method.

Further, an object of the present invention is to provide a toner in which a colorant and a release agent are well dispersed in a binder resin, a color toner has good color developability, a chargeability is stable, and a fog is not generated. It is in.

A further object of the present invention is to provide a toner having excellent offset performance because excessive molecular chain cutting does not occur in the kneading step.

[0012]

The constitution of the present invention for achieving the above-mentioned object of the present invention is the following (1) or (2).

(1) In a method for producing a color toner, which comprises a step of kneading a composition comprising at least a binder resin and a colorant using a twin-screw extruder, the twin-screw extruder is arranged in a barrel length direction. A composition having at least two or more raw material supply ports and having at least a binder resin and having a static bulk density of 0.30 to 0.70 g / ml provided on the most upstream side of the twin-screw extruder. 1 through the raw material supply port, the static bulk density of at least the colorant
A color having a kneading step of supplying 0.02 to 0.30 g / ml of a composition from a raw material supply port provided on the downstream side of the first raw material supply port of the twin-screw extruder and kneading. Toner manufacturing method.

(2) In a method for producing a toner, which comprises a step of kneading a composition comprising at least a binder resin, carbon black and a release agent by using a twin-screw extruder, the twin-screw extruder is arranged in a barrel length direction. Has at least two or more raw material supply ports, and a composition having a static bulk density of 0.30 to 0.70 g / ml, which is composed of at least a binder resin and a release agent, is provided on the most upstream side of the extruder. The static bulk density of at least carbon black is 0.
A toner having a kneading step of supplying and kneading a composition of 02 to 0.30 g / ml from a raw material supply port provided on the downstream side of the first raw material supply port of the twin-screw extruder. Manufacturing method.

[0015]

In the toner manufacturing method of the present invention, a colorant or the like having a low static bulk density is kneaded into a melt containing a binder resin as a main component, which has been melted in advance, so that the colorant and other binder resins can be highly treated. Since the dispersibility can be ensured, it is not necessary to apply a masterbatch method for previously dispersing the colorant in the resin or to provide a preliminary mixing step, and the manufacturing cost can be significantly reduced. In addition, the toner obtained by the toner production method of the present invention has the disadvantage that the toner obtained by the masterbatch method has a non-uniform charge due to the use of different resins, and the offset performance due to the progress of molecular chain breakage by kneading twice. Can be eliminated.

The present invention will be described in detail below.

The toner manufacturing method of the present invention comprises a color toner containing a binder resin, a colorant and, if necessary, other additives, or a binder resin, carbon black, a releasing agent and, if necessary, other additives. When manufacturing a toner containing an additive, a twin screw extruder having at least two or more raw material supply ports along the barrel length direction is used as a kneader, and the components to be kneaded are classified according to static bulk density. It is characterized in that it is supplied to the extruder from at least two locations and kneaded.

The static bulk density in the present invention will be described.

The static bulk density is measured by using a metal mesh of 48 mesh and adding a binder resin, a colorant, a release agent, etc., which are agitated in an amount of 20 g each for 1 minute, and vibrated to measure a volume of 20 ml. To receive. After leaving it for 30 seconds, weigh it to the volume of 20 ml. The static bulk density is defined as a value obtained by dividing the weight by the volume (= 20 ml) and rounding off to the third decimal place. Bulk density is Kawakita type static bulk density measuring instrument (manufactured by Seishin Enterprise Co., Ltd.) IH
It was measured using a -2000 model.

The toner and the method for producing the toner of the present invention are a toner produced by using a specific kneading machine and a method for producing the toner. A schematic configuration of an example of a toner manufacturing apparatus having a specific toner kneader is shown in FIGS. 1, 2 and 3.

In FIG. 1, 1 is a static bulk density of a binder resin or the like.
0.30 to 0.70 g / ml toner composition, 2 is a toner composition having a static bulk density of 0.02 to 0.30 g / ml such as a colorant, 3 is a feeder,
4 is a first raw material supply port, 5 is a side feeder, 6 is a second raw material supply port, 7 is a kneader motor, 8 is a reducer, 9 is a degassing vent, 10 is a discharge port, 11 is kneading In the zone, the twin-screw extruder is mainly composed of 4, 6, 7, 8, 10 and 11. 13 is a rolling roller for cooling, 14 is a cooling belt, 15 is a crusher, 16 is a classifier,
It is characterized by not having a premixing step.

FIG. 2 shows an example of a type in which two sets of feeders to the first raw material supply port 4 in FIG. 1 are provided, and the other parts have the same configuration as in FIG. Figure 3
In the type shown in FIG. 1, a side feeder and a raw material supply port are increased by one set, and 12 is a third raw material supply port. However, the number of raw material supply ports installed on the discharge port side of the first raw material supply port is at least one.

The kneading zone 11 is preferably disposed on the discharge port side of each raw material supply port, and the first, second and third knees corresponding to the first, second and third raw material supply ports are provided. It is preferable that the second and third kneading zones have a shorter length than the first kneading zone from the viewpoint that the length of the kneading zone is the same or that the breaking of the binder resin molecular chain is suppressed. The temperatures of the first, second and third kneading zones are preferably set within a temperature range of softening point + 20 ° C. to softening point −40 ° C. with respect to the softening point of the binder resin as the main component, It is not always necessary to set the same temperature. When kneading at a temperature exceeding the softening point + 20 ° C, the melt viscosity of the binder resin is lowered too much, the shearing force at the time of kneading is lowered, and the dispersion state of the colorant is deteriorated. On the other hand, softening point −40
When kneading at a temperature lower than ° C, the melting temperature of the binder resin is high, the shearing force at the time of kneading is high, the molecular chain breakage of the binder resin occurs, and the fixing performance of the toner deteriorates.

The feed rate of the raw materials fed from the feeder 3 and the side feeder 5 is not particularly limited, but the weight ratio of each component in the toner discharged from the discharge port is the same at the beginning and at the end of the discharged material. It is desirable to supply.

The toner manufacturing method of the present invention will be described with reference to FIG. The toner composition containing the binder resin as a main component, which is fed from the first raw material supply port 4, is melt-kneaded in the first kneading zone, and advances to the ejection port 10 side in a molten state. On the other hand, a colorant or the like is added to the molten binder resin component from the second raw material supply port 6, further melted and kneaded in the second kneading zone, and simultaneously discharged from the discharge port 10. After cooling, the powder is further pulverized and classified to make the volume average particle diameter of the toner 5 to 5.
Adjust to about 20 μm. From the viewpoint of ensuring toner flowability, inorganic fine particles such as silica and titanium oxide are added to finally obtain color toner particles.

In the toner manufacturing method of the present invention, when a plurality of toner compositions are simultaneously supplied from the same raw material supply port, the toner composition does not easily bite into the feed screw portion, resulting in poor dispersion in the toner. From the viewpoint of improving the dispersibility, it is possible to adopt a method in which two or more sets of feeders are provided as in the toner manufacturing apparatus shown in FIG. 2 and the toner compositions are separately supplied. When the difference in static bulk density is 0.20 g / ml or more, even if separate feeders are used, the effect of improving dispersibility is not obtained, the toner cannot be used as a toner, and the same raw material is supplied from the viewpoint of ensuring dispersibility. The difference in static bulk density between possible toner compositions is 0.20 g
</ Ml.

For example, the binder resin, the colorant, and the release agent are first
When it is supplied from the raw material supply port at the same time, the colorant takes in a large amount of air, so the static bulk density is small, the shearing force is not evenly applied during kneading, and the colorant and release agent are dispersed in the obtained toner. Defects occur. In addition, when components that do not contain a binder resin such as a colorant and a release agent are supplied to the first raw material supply port and the binder resin is supplied to the second raw material supply port, the binder that is not sufficiently melted Good dispersibility cannot be achieved because a colorant or the like is added to the resin.

The binder resin used in the present invention is not particularly limited, and examples thereof include polyester resin, styrene-methacrylic resin, styrene-butadiene resin, styrene-acrylonitrile resin, styrene-acrylic and polyester blend resin, styrene-acrylic and polyester. Graft resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl chloride, polyamide, polyvinyl butyral, rosin, modified rosin, phenol resin, xylene resin and the like can be mentioned, but they have a non-phase separation structure from the viewpoint of fixing performance and color mixing performance. A non-crystalline binder resin is preferable. Although the static bulk density of the binder resin changes depending on the synthesis method, the solution weight method,
The resin synthesized by the bulk polymerization method or the like is pulverized in advance, the number average particle diameter is adjusted to about 0.1 to 2 mm, and the mixture is subjected to the kneading step. When the suspension polymerization method, the emulsion polymerization method or the like is used, the number average particle diameter is about 0.1 to 1 mm. The static bulk density of the resin having such a number average particle diameter is about 0.50 to 0.70 g / ml.

The colorant contained in the color toner according to the first and second aspects of the invention is not particularly limited, and various conventionally known materials can be used. For example, pigments required for color toners include C.I. I. Pigment Blue 15: 3, C.I. I.
Pigment Blue 15, C.I. I. Pigment Blue 15:
6, C.I. I. Pigment Blue 68, C.I. I. Pigment Red 48-3, C.I. I. Pigment Red 122, C.I.
I. Pigment Red 212, C.I. I. Pigment Red 5
7-1, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 81, C.I. I. Pigment Yellow 154 and the like can be preferably used. As the dye, nigrosine dye, monoazo dye, anthraquinone dye,
Xanthene dyes and the like, and mixtures thereof can be used. The number average primary particle size of these colorants is 5 to 200 nm.
The static bulk density is about 0.10 to 0.20 g / ml.

In the toner base particles (toner particles containing no external additive; hereinafter referred to as "colored particles") of the color toner of the inventions according to claims 1 and 2, in addition to the binder resin and the colorant, a charge control agent is used. , A release agent and the like can be contained.

As the releasing agent, a low molecular weight polyethylene having a number average molecular weight (the number average molecular weight indicates a polystyrene molecular weight conversion value in high temperature GPC) of 1500 to 5000, a low molecular weight polypropylene, a low molecular weight polyethylene-polypropylene copolymer, etc. Polyolefin wax, or high-melting paraffin wax such as microwax or Fischer-Tropsch wax, or ester wax such as fatty acid lower alcohol ester, fatty acid higher alcohol ester, fatty acid polyhydric alcohol ester, or amide wax, alone or in combination. Can be used. The static bulk density of these release agents is about 0.30 to 0.55 g / ml.

A charge control agent may be used as another component. For example, colorless such as quaternary ammonium salt compound,
Alternatively, a light-colored charge control agent can be used.

The amount of the colorant, the release agent, the charge control agent, etc., added to the colored particles is not particularly limited, but is 1% by weight to each.
A range of 50% by weight is preferred.

Any external additive may be used as long as it can improve the fluidity of the toner. Silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, and oxides. Inorganic fine particles such as chromium, cerium oxide, antimony trioxide and zirconium oxide can be used.
These may be hydrophobized.

[0035]

EXAMPLES The present invention will be further described below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In addition, "part" represents a weight part.

Example 1 Binder resin: Styrene acrylic resin (softening point 115 ° C., static bulk density 0.58 g / ml) 100 parts Coloring agent: C.I. I. Pigment Blue 15: 3 (number average particle size 60 nm, static bulk density 0.17 g / ml) 3 parts Release agent: low molecular weight polypropylene (static bulk density 0.50 g / ml) 6 parts Using the toner manufacturing apparatus shown in FIG. Binder resin 100
Parts and 6 parts of mold release agent are separately supplied from the first raw material supply port 4 at a rate of 6.3 kg / h by separate feeders 3, the screw rotation speed is 200 rpm, and the first (upstream) kneading barrel temperature. Is set to 130 ° C and kneaded.
From the raw material supply port 6 of the above, at a rate of 0.2 kg / h,
The second (downstream side) kneading barrel temperature was set to 130 ° C., melted and kneaded, and then cooled, pulverized and classified to obtain colored particles having a volume average particle diameter of 9 μm. Further, 0.4 part of hydrophobic silica was added to the colored particles to obtain Toner A of the present invention. The dispersion state of the internal additive in the resin of this toner A was almost uniform.

In Example 1 and the following Examples and Comparative Examples, the static bulk density was measured using a Kawakita type static bulk density measuring instrument (manufactured by Seishin Enterprise Co., Ltd.) Model IH-2000. The dispersed state of the internal additive in the toner particles was taken out from the discharge port of the twin screw extruder, taken out from the sample that had been cooled and rolled, sliced with a microtome and observed with a polarizing microscope. The number average particle diameters of the binder resin and the colorant were visually measured with a scanning electron microscope. As for the softening point of the binder resin, a flow tester CFT-500 (manufactured by Shimadzu Corporation) was used, and a sample of 1 cm ³ was heated at a temperature rising rate of 6 ° C./minute while the pressure was 20 kg / cm ³ from the plunger. A load is applied so that a nozzle with a diameter of 1 mm is pushed out, whereby a curve (softening flow curve) between the plunger drop amount and temperature of the flow tester is drawn, and when the height of the S-shaped curve is h, h The temperature corresponds to / 2.

This toner A is used as a copying machine U-B manufactured by Konica Corporation.
Offset performance evaluation of ix1017 (equipped with fluororesin-coated heat roller, no roller cleaning mechanism, modified fixing roller setting temperature variable type) heat roller linear velocity of 130 mm / sec and linear pressure of 0.80 kg / cm The offset phenomenon did not occur up to 200 ° C.

Further, the toner A was subjected to real image evaluation using a full-color electrophotographic copying machine U-Bix9028 manufactured by Konica Corporation. As a result, the change in the charge amount with time was small, there was no fog, and at the same time the color development was excellent. Was there.

Example 2 Binder resin: Styrene acrylic resin (softening point 125 ° C., static bulk density 0.53 g / ml) 100 parts Coloring agent: C.I. I. Pigment Red 31 (number average particle size 200 nm, static bulk density 0.17 g / ml) 6 parts Using the toner manufacturing apparatus shown in FIG.
Through the feeder through the first raw material supply port 4 to 6.0 kg
/ H at a fixed rate, the screw rotation speed is 180 rpm,
The first kneading barrel temperature was set to 150 ° C and the mixture was melt-kneaded, and 6 parts of the colorant was supplied from the second raw material supply port at 0.4 kg /
A fixed amount was supplied at a rate of h, the second kneading barrel temperature was set to 130 ° C., the mixture was melt-kneaded, then cooled, pulverized and classified to obtain colored particles having a volume average particle diameter of 7 μm. Further, 0.9 part of hydrophobic silica was added to the colored particles to obtain Toner B of the present invention. The dispersion state of the colorant in the binder resin of this toner B was almost uniform.

This toner B is used as a copying machine U-B manufactured by Konica Corporation.
Offset performance was evaluated by setting the linear speed of the heat roller of ix1017 (equipped with a fluororesin coated heat roller, silicone oil coating device, modified fixing roller setting temperature type) to 130 mm / sec and the linear pressure to 0.80 kg / cm. As a result, the offset phenomenon did not occur up to 210 ° C.

Further, this toner B was subjected to real image evaluation using a full-color electrophotographic copying machine U-Bix9028 manufactured by Konica Corporation. As a result, the change in charge amount over time was small, there was no fog, and at the same time the color development was excellent. Was there.

Example 3 Binder resin: polyester resin (softening point 128 ° C., static bulk density 0.63 g / ml) 100 parts Coloring agent: C.I. I. Pigment Yellow 17 (number average particle size 100 nm, static bulk density 0.18 g / ml) 7 parts Release agent: paraffin wax (static bulk density 0.32 g / ml) 3 parts Using the toner manufacturing apparatus shown in FIG. Resin 100
Parts and 3 parts of mold release agent are separately supplied through separate feeders from the first raw material supply port 4 at a total speed of 6.0 kg / h, the screw rotation speed is 150 rpm, and the first kneading barrel temperature is 130 ° C. After melt-kneading, the colorant 7 parts was supplied from the second raw material supply port 6 at a rate of 0.3 kg / h, and the second kneading barrel temperature was set to 110 ° C. After cooling, crushing and classification, colored particles having a volume average particle size of 8 μm were obtained. Further, 0.6 part of hydrophobic silica was added to the colored particles to obtain Toner C of the present invention. The dispersion state of the internal additive in the binder resin of this toner C was almost uniform.

This toner C is used as a copying machine U-B manufactured by Konica Corporation.
Offset performance evaluation of ix1017 (equipped with fluororesin-coated heat roller, no roller cleaning mechanism, modified fixing roller setting temperature variable type) heat roller linear velocity of 130 mm / sec and linear pressure of 0.80 kg / cm The offset phenomenon did not occur up to 220 ° C.

Further, the toner C was evaluated for actual copying using a full-color electrophotographic copying machine U-Bix9028 manufactured by Konica Corporation. As a result, the change in the charge amount with time was small and the coloring property was excellent.

Example 4 Binder resin: polyester resin (softening point 112 ° C., static bulk density 0.63 g / ml) 100 parts Colorant A: C.I. I. Pigment Red 122 (number average particle size 100 nm, static bulk density 0.17 g / ml) 3 parts Colorant B: anthraquinone dye (number average particle size 70 nm, static bulk density 0.12 g / ml) 3 parts Using the toner manufacturing apparatus shown in FIG. The above-mentioned binder resin 100
Parts from the first raw material supply port 4, colorant A3 parts from the second raw material supply port 6, and colorant B3 parts from the third raw material supply port 12 to 5.5 kg / h, 0.3 kg / h, 0.3, respectively. A fixed amount was supplied at a rate of kg / h, the screw rotation speed was set to 220 rpm, the total kneading barrel temperature was set to 130 ° C., and the mixture was kneaded, then cooled, pulverized and classified to obtain colored particles having a volume average particle diameter of 9 μm. . 0.4 parts of hydrophobic silica and 0.3 part of titanium oxide were added to the obtained colored particles to obtain toner D of the present invention. The dispersibility of the internal additive in the binder resin of this toner D was substantially uniform.

This toner D is used as a copying machine U-B manufactured by Konica Corporation.
Offset performance was evaluated by setting the linear speed of the heat roller of ix1017 (equipped with a fluororesin coated heat roller, silicone oil coating device, modified fixing roller setting temperature type) to 130 mm / sec and the linear pressure to 0.80 kg / cm. As a result, the offset phenomenon did not occur up to 200 ° C.

Further, this toner D was evaluated for actual copying using a full-color electrophotographic copying machine U-Bix9028 manufactured by Konica Corporation. As a result, the change in the amount of charge with time was small and the coloring property was excellent.

Comparative Example 1 Binder resin: Styrene acrylic resin (softening point 120 ° C., static bulk density 0.55 g / ml) 100 parts Coloring agent: C.I. I. Pigment Blue 68 (Number average particle size 80 nm, static bulk density 0.12 g / ml)
10 parts Release agent: low molecular weight polypropylene (static bulk density 0.52 g / ml) 5 parts Using the toner production apparatus shown in FIG.
Parts, 10 parts of colorant, and 5 parts of release agent are batch-fed at a rate of 6.2 kg / h from the first raw material supply port 4 through the same feeder at a screw rotation speed of 200 rpm, first and second.
The kneading barrel temperature was set to 115 ° C., the mixture was melt-kneaded, then cooled, pulverized and classified to obtain colored particles having a volume average particle diameter of 7 μm. Furthermore, the colored particles are coated with hydrophobic silica 0.5.
Parts were added to obtain comparative toner E. The colorant in the binder resin of this toner E was agglomerated and the dispersion state was non-uniform.

This toner E is used as a copying machine U-B manufactured by Konica Corporation.
Offset performance evaluation of ix1017 (equipped with fluororesin-coated heat roller, no roller cleaning mechanism, modified fixing roller setting temperature variable type) heat roller linear velocity of 130 mm / sec and linear pressure of 0.80 kg / cm The offset phenomenon occurred at 180 ° C.

Further, this toner E was subjected to actual copying evaluation using a full-color electrophotographic copying machine U-Bix9028 manufactured by Konica Co., Ltd., and as a result, the electrification amount was decreased with the passage of time, and the fixing roller cleaning member was also heavily soiled. As a result, the long-term durability was lacking, and the color developing property of the color toner was not uniform.

Comparative Example 2 Binder resin: polyester resin (softening point 128 ° C., static bulk density 0.62 g / ml) 100 parts Coloring agent: C.I. I. Pigment Red 48-3 (number average particle size 20 nm, static bulk density 0.11 g / ml) 5 parts Release agent: paraffin wax (static bulk density 0.31 g / ml) 4 parts Using the toner production apparatus shown in FIG. Binder resin 100
Part and 4 parts release agent through the same feeder at once 6.8k
A fixed amount is supplied from the first raw material supply port 4 at a speed of g / h,
The screw rotation speed is set to 200 rpm, the first kneading barrel temperature is set to 120 ° C., and the mixture is melt-kneaded.
/ H at a constant rate through the second raw material supply port 6, the second kneading barrel temperature was set to 120 ° C, melted and kneaded, and then cooled, pulverized and classified to give colored particles having a volume average particle diameter of 9 µm. Got Furthermore, hydrophobic silica 0.6 is added to the colored particles.
Parts were added to obtain comparative toner F. The release agent of this toner F was segregated and aggregated in the toner.

This toner F is used as a copying machine U-B manufactured by Konica Corporation.
Offset performance evaluation of ix1017 (equipped with fluororesin-coated heat roller, no roller cleaning mechanism, modified fixing roller setting temperature variable type) heat roller linear velocity of 130 mm / sec and linear pressure of 0.80 kg / cm The offset phenomenon occurred at 170 ° C.

Further, this toner F was evaluated for actual copying using a full-color electrophotographic copying machine U-Bix9028 manufactured by Konica Corporation. As a result, the photoconductor was contaminated due to the release of the release agent from the toner surface. The image quality was deteriorated, the toner charge amount was drastically reduced, and fog was generated, so that it could not be used for a long time.

Comparative Example 3 Binder resin: Styrene acrylic resin (softening point 135 ° C., static bulk density 0.59 g / ml) 100 parts Coloring agent: C.I. I. Pigment Blue 15: 3 (number average particle diameter 60 nm, static bulk density 0.19 g / ml) 10 parts Release agent: low molecular weight polypropylene (static bulk density 0.52 g / ml) 2 parts Using the toner manufacturing apparatus shown in FIG. 2 parts of the mold release agent and 10 parts of the colorant are supplied at a constant rate of 0.7 kg / h from the first raw material supply port 4 through separate feeders, the screw rotation speed is 180 rpm, and the first kneading barrel temperature is 15
Melt kneading is performed by setting the temperature to 0 ° C, 100 parts of the binder resin is quantitatively supplied from the second raw material supply port 6 at a rate of 6.6 kg / h, and the second kneading barrel temperature is set to 105 ° C and kneading is performed. After that, it was cooled, pulverized, and classified to obtain colored particles having a volume average particle diameter of 8 μm. Further, 0.7 part of hydrophobic silica was added to the colored particles to obtain comparative toner G. The dispersibility of the colorant and the release agent in the binder resin of this toner G was non-uniform, and it did not have the chromaticity particularly required as a color toner.

This toner G is used as a copying machine U-B manufactured by Konica Corporation.
Offset performance evaluation of ix1017 (equipped with fluororesin-coated heat roller, no roller cleaning mechanism, modified fixing roller setting temperature variable type) heat roller linear velocity of 130 mm / sec and linear pressure of 0.80 kg / cm The offset phenomenon occurred at 160 ° C.

Further, this toner G was not evaluated for actual copying using a full-color electrophotographic copying machine U-Bix9028 manufactured by Konica Corporation, because it did not have the chromaticity required as a color toner.
The image density was low from the beginning and it was not practical.

Comparative Example 4 Binder resin: Styrene acrylic resin (softening point 125 ° C., static bulk density 0.53 g / ml) 100 parts Coloring agent: C.I. I. Pigment Yellow 12 (number average particle size 70 nm, static bulk density 0.17 g / ml) 6 parts Using the toner manufacturing apparatus shown in FIG.
Parts and 6 parts of colorant are supplied at a rate of 7.0 kg / h from the first raw material supply port 4 through separate feeders, the screw rotation speed is 180 rpm, and the first and second kneading barrel temperatures are 140 ° C. After setting and melting and kneading, cooling, pulverization and classification were carried out to obtain colored particles having a volume average particle diameter of 7 μm. Further, 0.9 part of hydrophobic silica was added to the colored particles to obtain comparative toner H. Segregation and aggregation of the colorant in the binder resin of this toner H were observed, and the dispersion state was not uniform.

This toner H is used as a copying machine U-B manufactured by Konica Corporation.
Offset performance was evaluated by setting the linear speed of the heat roller of ix1017 (equipped with a fluororesin coated heat roller, silicone oil coating device, modified fixing roller setting temperature type) to 130 mm / sec and the linear pressure to 0.80 kg / cm. As a result, the offset phenomenon did not occur up to 210 ° C.

Further, this toner H was subjected to actual copying evaluation using a full-color electrophotographic copying machine U-Bix9028 manufactured by Konica Corp., and as a result, the charge amount with time decreased and at the same time, the color developability as a color toner was inferior. Met.

Comparative Example 5 C.I. I. Pigment red
30% by weight of 48-3 pigment was added and mixed, and the mixture was repeatedly kneaded with a two-roll mill to obtain a masterbatch pigment A.

Binder resin: polyester resin (softening point 128 ° C. static bulk density 0.62 g / ml) 100 parts Coloring agent: masterbatch pigment A (resin softening point 110 ° C. static bulk density 0.48 g / ml) 10 parts FIG. Using the toner manufacturing apparatus shown in FIG.
Parts and 10 parts of colorant are fed through separate feeders from the first raw material supply port 4 at a constant rate of 7.0 kg / h, the screw rotation speed is 180 rpm, and the first and second kneading barrel temperatures are 140 ° C. After melting and kneading, the mixture was cooled, pulverized and classified to obtain colored particles having a volume average particle diameter of 7 μm.
Further, 0.9 part of hydrophobic silica was added to the colored particles to obtain a comparative toner I. The dispersion state of the colorant in the binder resin of Toner I was almost uniform.

This toner I is used as a copying machine U-B manufactured by Konica Corporation.
Offset performance was evaluated by setting the linear speed of the heat roller of ix1017 (equipped with a fluororesin coated heat roller, silicone oil coating device, modified fixing roller setting temperature type) to 130 mm / sec and the linear pressure to 0.80 kg / cm. As a result, the offset phenomenon occurred at 170 ° C.

Further, this toner I was evaluated for actual copying using a full-color electrophotographic copying machine U-Bix9028 manufactured by Konica Corporation. As a result, the fixing roller cleaning device was heavily soiled and was not practical.

Example 5 Binder resin: Styrene acrylic resin (softening point 128 ° C., static bulk density 0.55 g / ml) 100 parts Coloring agent: furnace black (number average primary particle size 25 nm, static bulk density 0.19 g / ml) 8 parts Release agent: low molecular weight polypropylene (static bulk density 0.48 g / ml) 6 parts Using the toner manufacturing apparatus shown in FIG.
Parts and 6 parts of release agent are separately fed through the feeder at a rate of 6.3 kg / h from the first raw material supply port 4, the screw rotation speed is 200 rpm, and the first kneading barrel temperature is 12
The mixture was kneaded at 0 ° C., 8 parts of carbon black was quantitatively supplied from the second raw material supply port 6 at a rate of 0.5 kg / h, and the second kneading barrel temperature was set at 120 ° C. to melt and knead. After that, it is cooled, crushed, classified and the volume average particle size is 10 μm
To obtain colored particles of. Furthermore, hydrophobic silica 0.
Toner J of the present invention was obtained by adding 8 parts. This toner J
The dispersion state of the carbon black and the release agent in the binder resin was almost uniform.

This toner J is a copy machine U-B manufactured by Konica Corporation.
The offset performance of ix1017 (equipped with a fluorine resin coated heat roller and modified fixing roller setting temperature variable type) heat roller linear velocity was set to 130 mm / sec and linear pressure was set to 0.80 kg / cm. It did not occur up to ℃.

Further, this toner J is used as a copying machine U manufactured by Konica Corporation.
As a result of performing an actual copy evaluation using -Bix3135, the change in the charge amount with time was small, and fog did not occur up to 30,000 copies.

Example 6 Binder resin: polyester resin (softening point 142 ° C., static bulk density 0.63 g / ml) 100 parts Coloring agent: furnace black (number average primary particle diameter 16 nm, static bulk density 0.15 g / ml) 10 Part Release agent: Paraffin wax (Static bulk density 0.32 g / ml) 3 parts Using the toner manufacturing apparatus shown in FIG.
Parts and 3 parts of mold release agent are separately supplied through separate feeders from the first raw material supply port 4 at a total speed of 6.0 kg / h, the screw rotation speed is 150 rpm, and the first kneading barrel temperature is 150 ° C. And kneading, 10 parts of the colorant is supplied from the second raw material supply port 6 at a rate of 0.5 kg / h, the second kneading barrel temperature is set to 120 ° C., and the mixture is kneaded.
It was cooled, pulverized, and pulverized to obtain colored particles having a volume average particle diameter of 8 μm. Further, 0.5 part of hydrophobic silica and 0.4 part of titanium oxide were added to the colored particles to obtain toner K of the present invention. The dispersion state of the carbon black and the release agent in the binder resin of this toner K was substantially uniform.

This toner K is used as a copying machine U-B manufactured by Konica Corporation.
The offset performance of ix1017 (equipped with a fluorine resin coated heat roller and modified fixing roller setting temperature variable type) heat roller linear velocity was set to 130 mm / sec and linear pressure was set to 0.80 kg / cm. It did not occur up to ℃.

Further, this toner K is used as a copying machine U manufactured by Konica Corporation.
As a result of performing an actual copy evaluation using -Bix3135, the change in the charge amount with time was small, and fog did not occur up to 30,000 copies.

Example 7 Binder resin: Styrene acrylic-polyester graft resin (softening point 122 ° C. static bulk density 0.63 g / ml) 100 parts Coloring agent: furnace black (number average primary particle size 23 nm, static bulk density 0.13 g) / Ml) 8 parts Release agent: low molecular weight polypropylene (static bulk density 0.48 g / ml) 3 parts Using the toner manufacturing apparatus shown in FIG.
Parts from the first raw material supply port 4, 8 parts of the colorant from the second raw material supply port 6, and 3 parts of the release agent to the third raw material supply port 12.
From 5.6kg / h, 0.7kg / h, 0.3kg / h at a constant rate, screw rotation speed is 220rpm, total kneading barrel temperature is set to 135 ° C, and after kneading, cooling,
The particles were pulverized and classified to obtain colored particles having a volume average particle diameter of 9 μm. Add 0.9 parts of hydrophobic silica to the obtained colored particles,
The toner L of the present invention was obtained. The dispersibility of the carbon black and the release agent in the binder resin of this toner L was substantially uniform.

This toner L is used as a copying machine U-B manufactured by Konica Corporation.
The offset performance of ix1017 (equipped with a fluorine resin coated heat roller and modified fixing roller set temperature variable type) heat roller linear velocity was set to 130 mm / sec and linear pressure was set to 0.80 kg / cm, and the offset phenomenon was 210. It did not occur up to ℃.

Further, this toner L is used as a copying machine U manufactured by Konica Corporation.
As a result of performing an actual copy evaluation using -Bix3135, the change in the charge amount with time was small, and fog did not occur up to 30,000 copies.

Comparative Example 6 Binder resin: Styrene acrylic resin (softening point 130 ° C., static bulk density 0.52 g / ml) 100 parts Coloring agent: furnace black (number average primary particle diameter 35 nm, static bulk density 0.17 g / ml) 10 parts Release agent: low molecular weight polypropylene (static bulk density 0.52 g / ml) 5 parts Using the toner manufacturing apparatus shown in FIG.
Parts, 10 parts of colorant, and 5 parts of release agent are batch-fed at a rate of 5.8 kg / h from the first raw material supply port 4 through the same feeder at a screw rotation speed of 200 rpm, first and second.
The kneading barrel temperature was set to 105 ° C., and the mixture was melt-kneaded, then cooled, pulverized, and pulverized to obtain colored particles having a volume average particle diameter of 9 μm. In addition, the colored particles have a hydrophobic silica content of 0.8.
Parts were added to obtain a comparative toner M. In this toner M, aggregates of carbon black were observed and the dispersion state was non-uniform.

This toner M is used as a copying machine U-B manufactured by Konica Corporation.
The offset performance of ix1017 (equipped with a fluorine resin coated heat roller and modified fixing roller setting temperature variable type) heat roller linear velocity was set to 130 mm / sec and linear pressure was set to 0.80 kg / cm. Occurred at ° C.

Further, this toner M is used as a copying machine U manufactured by Konica Corporation.
As a result of performing an actual copy evaluation using -Bix3135, the amount of charge was drastically reduced, and fogging on the image was serious after 1000 copies, and it was not practical.

Comparative Example 7 Binder resin: polyester resin (softening point 128 ° C., static bulk density 0.62 g / ml) 100 parts Coloring agent: channel black (number average primary particle size 22 nm, static bulk density 0.11 g / ml) 12 Part Release agent: Paraffin wax (Static bulk density 0.31 g / ml) 4 parts Using the toner manufacturing apparatus shown in FIG.
Part and 4 parts release agent through the same feeder at once 6.8k
A fixed amount is supplied from the first raw material supply port 4 at a speed of g / h,
The screw rotation speed is set to 200 rpm, the first kneading barrel temperature is set to 120 ° C., and the mixture is melt-kneaded.
The raw material is supplied from the raw material supply port 6 of 0.7 kg / h at the second
The kneading barrel temperature was set to 120 ° C., and the mixture was kneaded, cooled, pulverized, and classified to obtain colored particles having a volume average particle diameter of 8 μm. Further, 0.7 part of hydrophobic silica was added to the colored particles to obtain a toner N for comparison. The release agent of this toner N partially aggregated and the dispersion state was non-uniform.

This toner N is used as a copying machine U-B manufactured by Konica Corporation.
ix1017 (equipped with fluororesin coated heat roller, modified fixing roller setting temperature variable type) heat roller linear velocity was set to 130 mm / sec and linear pressure was set to 0.80 kg / cm. Occurred at ° C.

Further, this toner N is used as a copying machine U manufactured by Konica Corporation.
As a result of performing an actual copy evaluation using -Bix3135, the charge amount distribution showed a tendency to widen with time, and fogging on the image was severe after 5000 copies and it was not practical.

Comparative Example 8 Binder resin: Styrene acrylic resin (softening point 135 ° C. static bulk density 0.59 g / ml) 100 parts Coloring agent: furnace black (number average primary particle diameter 28 nm, static bulk density 0.19 g / ml) 10 parts Release agent: low molecular weight polypropylene (static bulk density 0.52 g / ml) 2 parts Using the toner manufacturing apparatus shown in FIG. 2, 2 parts of the above release agent and 10 parts of colorant are passed through separate feeders to obtain the first A constant amount of 0.7 kg / h is supplied from the raw material supply port 4, the screw speed is 180 rpm, and the first kneading barrel temperature is 15
Melt kneading is performed by setting the temperature to 0 ° C, 100 parts of the binder resin is quantitatively supplied from the second raw material supply port 6 at a rate of 6.6 kg / h, and the second kneading barrel temperature is set to 105 ° C and kneading is performed. After that, it was cooled, pulverized, and classified to obtain colored particles having a volume average particle diameter of 8 μm. Further, 0.5 part of titanium oxide was added to the colored particles to obtain a toner P for comparison. The dispersibility of the carbon black and the release agent of this toner P was non-uniform, and the obtained toner was grayish white.

This toner P is used as a copying machine U-B manufactured by Konica Corporation.
ix1017 (equipped with fluororesin coated heat roller, modified fixing roller setting temperature variable type) heat roller linear velocity was set to 130 mm / sec and linear pressure was set to 0.80 kg / cm. Occurred at ° C.

[0082]

According to the present invention, in a method for producing a toner including a melt-kneading step using a twin-screw extruder, a toner such as a colorant or a release agent can be prepared in a resin even if the premixing step is omitted. Since good dispersibility can be ensured and the preliminary mixing step can be omitted, the manufacturing process can be simplified, the manufacturing efficiency can be increased, and the manufacturing cost of the toner can be reduced. Further, since the toner produced by the production method of the present invention is excellent in the dispersibility of the internal additive, not only the uniformity of the charge amount of the toner is ensured, but also the color development as a color toner is excellent, and the binder resin A toner having excellent offset performance can be provided by reducing excessive breakage of molecular chains.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a twin-screw extruder used in a method for producing a toner of the present invention.

FIG. 2 is a schematic configuration diagram showing another example of the twin-screw extruder used in the toner manufacturing method of the present invention.

FIG. 3 is a schematic configuration diagram showing still another example of the twin-screw extruder used in the toner manufacturing method of the present invention.

[Explanation of symbols]

 4 First raw material supply port 6 Second raw material supply port 11 Kneading zone 12 Third raw material supply port

Claims (4)

[Claims] 1. A color toner obtained by kneading a composition comprising at least a binder resin and a colorant using at least a twin-screw extruder, wherein the twin-screw extruder has at least two locations in the barrel length direction. A first raw material having the above raw material supply ports and provided with a composition containing at least a binder resin and having a static bulk density of 0.30 to 0.70 g / ml on the most upstream side of the twin screw extruder. It is supplied from the supply port and has a static bulk density of at least 0.02 consisting of colorant.
0.30 g / ml of composition was added to the first of the twin screw extruder.
A color toner that is supplied and kneaded from a raw material supply port provided on the downstream side of the raw material supply port. 2. A method for producing a color toner comprising a step of kneading a composition comprising at least a binder resin and a colorant using a twin-screw extruder, wherein the twin-screw extruder is at least in the barrel length direction. A composition having two or more raw material supply ports and having at least a binder resin and having a static bulk density of 0.30 to 0.70 g / ml provided on the most upstream side of the twin-screw extruder. It is supplied from the raw material supply port of, and the static bulk density of at least the colorant is 0.
A color comprising a kneading step of feeding and kneading a composition of 02 to 0.30 g / ml from a raw material supply port provided on the downstream side of the first raw material supply port of the twin screw extruder. Toner manufacturing method. 3. A toner obtained by kneading a composition comprising at least a binder resin, carbon black and a releasing agent using at least a twin screw extruder, wherein the twin screw extruder is at least in the barrel length direction. A composition having two or more raw material supply ports and having a static bulk density of 0.30 to 0.70 g / ml composed of at least a binder resin and a release agent is provided on the most upstream side of the twin screw extruder. A composition having a static bulk density of 0.02 to 0.30 g / ml, which is supplied from the first raw material supply port and is made of at least carbon black, is provided downstream of the first raw material supply port of the twin-screw extruder. The toner is characterized in that it is supplied from the raw material supply port and kneaded. 4. A method for producing a toner, comprising the step of kneading a composition comprising at least a binder resin, carbon black and a release agent using a twin-screw extruder, wherein the twin-screw extruder is in the barrel length direction. A composition having at least two or more raw material supply ports and having a static bulk density of 0.30 to 0.70 g / ml composed of at least a binder resin and a release agent is provided on the most upstream side of the extruder. It is supplied from the raw material supply port 1 and has a static bulk density of at least carbon black of 0.
A toner having a kneading step of supplying and kneading a composition of 02 to 0.30 g / ml from a raw material supply port provided on the downstream side of the first raw material supply port of the twin-screw extruder. Manufacturing method.