JP2001166530A - Method for kneading toner, method for manufacturing toner and electrophotographic toner manufactured by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for kneading toners which can improve the dispersibility of coloring agents and charge control agents into a binder resin without dropping a mixture supplied to a continuous twin roll type kneading machine, a method for manufacturing the toners and the electrophotographic toners manufactured by using the same. SOLUTION: The toners are manufactured by previously heating a powder mixture containing at least the binder resin and the coloring resins, supplying the mixture to the continuous twin roll type kneading machine and melting and kneading the mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for kneading and kneading a toner used in electrophotography, electrostatic printing and the like, a method for producing a toner, and a toner produced using the same. The present invention relates to a kneading method, a toner manufacturing method, and an electrophotographic toner manufactured using the same.

[0002]

2. Description of the Related Art In electrophotography, a photoconductive substance is generally used to form an electric latent image on a photoreceptor by various methods, and then the latent image is developed using toner.
A method is known in which a toner image is transferred to a transfer material such as paper as necessary, and then fixed by various methods to form an image.

[0003] Toner is a powder that forms an image, but it is necessary for the toner particles to have many functions in order to form an image accurately. For example, chargeability, transportability, fixability, coloring power, storage stability, and the like. Therefore, the toner is produced as a mixture of various raw materials.

[0004] As a method for producing a dry toner, a pulverization method,
Although a polymerization method and an encapsulation method are mentioned, a pulverization method is the mainstream in general.

[0005] As a method for producing a toner by a general pulverization method, a raw material comprising additives such as a binder resin for fixing to a material to be transferred, various colorants for producing color, and a charge controlling agent is dry-processed. After mixing, the mixed powder is melt-kneaded with a compressive force and a shearing force while applying a temperature with a general-purpose kneading device such as a twin-screw extruder, a kneader, and a continuous two-roll kneader, After being cooled and solidified, coarse pulverization is performed as necessary to produce a kneaded coarse powder, and then finely pulverized to an appropriate particle size as a toner using a fine pulverizing device such as a jet mill.

Next, classification is performed by various classifiers as necessary, and the particle size is adjusted to a particle size distribution capable of exhibiting sufficient performance as a toner. Further, if necessary, a fluidity improver, a lubricant and the like are dry-mixed and used as a toner.

Here, as one of the factors relating to the performance of the toner, there is a charge amount distribution. The distribution of the charge amount depends on the amounts of the colorant and the charge control agent, but also largely depends on the degree of dispersion of the colorant and the charge control agent.

[0008] The dispersion state of the toner particles of various raw materials in the toner is determined in the toner production process by the pulverization method.
It is almost determined by the raw material mixing step and the kneading step. As a device used for mixing raw materials, a container rotating type mixer such as a V blender or a W cone or a high-speed stirring type mixing device such as a Henschel mixer is generally used, and a mixture adjusted by these devices is used. Is melt-kneaded with a kneader or a twin-screw extruder.

However, the kneaded product obtained by the above-described production method has a large charge amount distribution because the dispersion state of the colorant and the charge control agent in the binder resin is insufficient, which is different from the desired charge. There are many toners with opposite polarity charging,
Printed images using these toners cause problems such as fogging. Further, in the color toner, the dispersion of the colorant is insufficient, so that the transmittance of the OHP film deteriorates,
Causes blurring of the image.

Therefore, recently, in order to improve the dispersibility of the colorant and the charge controlling agent in the binder resin, a continuous two-roll kneader having a stronger shearing force than the above-described kneader or twin-screw extruder. (Also called a continuous two-roll mill)
Is used.

Here, FIG. 1 is a view showing the outline of this continuous two-roll kneader, FIG. 1 (a) is a side view of the entire apparatus, and FIG. FIG. 1C is a schematic cross-sectional view of the vicinity of a toner raw material supply unit.

In FIG. 1, reference numeral 10 denotes a continuous two-roll kneader. The continuous two-roll kneader 10 is provided with two rolls, 1 is a back roll, and 2 is a front roll. Is shown. Reference numeral 3 denotes a toner raw material supply unit, and reference numeral 4 denotes a kneaded material discharge unit. Reference numeral 5 denotes a spiral groove provided on each surface of the back roll 1 and the front roll 2. Reference numerals 6 and 7 denote heat medium supply / discharge units for the back roll 1 and the front roll 2, and reference numerals 8 and 9 denote roll drive motors.

In FIG. 1, the back roll 1 and the front roll 2 of the continuous two-roll kneader are each hollow inside, and a spiral pipe is provided inside the roll surface. (Not shown). This spiral pipe is used in the front roll 2 as shown in FIG.
As shown by the broken line in (b), the roll is divided into two parts at a ratio of 1: 1 from the vicinity of the center of the roll to the side of the toner raw material supply section 3 and the side of the kneaded material discharge section. A heat medium such as steam, hot water, oil, or a coolant such as cooling water flows from the heat medium supply / discharge portions 7 and 8 into the spiral pipe (in the present invention, the heat medium, the coolant and the like). And abbreviated as heating medium). Then, by supplying a heating medium to the spiral pipe, the surface temperature of each of the back roll 1 and the front roll 2 is arbitrarily controlled. As shown in FIGS. 1A and 1B, the back roll 1 and the front roll 2 each have a spiral groove 5 on the surface.
And has a cylindrical shape.

Next, a conventional melt kneading process using the continuous two-roll kneader shown in FIG. 1 will be described.

As shown by a broken line in FIG. 1B, the front roll 2 of the continuous two-roll type kneader 10 has a cooling structure in which a heat medium is separated near the center thereof. A heat medium at a temperature at which the binder resin is melted is supplied near the raw material supply unit 3 side, and a heat medium at a lower temperature is supplied at the kneaded material discharge unit 4 side. Is increased to increase the dispersibility of the colorant and the charge control agent in the binder resin.

On the other hand, the back roll 1 is
In the same manner as described above, a cooling structure in which the heat medium is separated near the center, or a structure in which the cooling structure is not separated, in each case, a heat medium at a temperature lower than the discharge side temperature of the front roll 2 is supplied, Back roll 1, Front roll 2
Is increased to increase the dispersibility of the colorant and the charge control agent in the binder resin.

The kneaded material using such a continuous two-roll kneader has a good dispersion state of the colorant and the charge controlling agent in the binder resin, and the kneaded material is used for pulverization and classification. The printing characteristics of the performed toner are good. FIG. 4 shows a process chart of a conventional toner manufacturing method using the continuous two-roll kneader described above.

[0018]

However, when a continuous two-roll kneader is used, when a mixed powder, which is a mixture of a binder resin, a colorant, and the like, is supplied to the kneader, the mixed powder is mixed. The amount that falls without wrapping around the roll is large,
The productivity was poor. This is because when the mixed powder is supplied to a continuous two-roll kneader, the binder resin in the mixed powder is melted by the heat of the front roll and adheres to the roller. When the amount increases, the binder resin on the upper layer deposited on the surface of the front roller can obtain sufficient heat until it melts.When the roller moves downward due to the rotation of the roller, the mixture that does not adhere to the roller Is to fall by its own weight.

On the other hand, in order to prevent this drop, a method of raising the temperature of the heating medium supplied to the front roll and sufficiently melting the binder resin of the mixture can be considered, but this method lowers the melt viscosity of the mixture, Along with this, the shearing force becomes smaller, and the dispersibility of the colorant and the charge control agent in the binder resin becomes worse.

As still another solution, a method is considered in which the temperature of the heating medium supplied to the back roll is increased and the binder resin of the mixture is heated from both the front roll and the back roll. There is a problem that the shearing force of the continuous two-roll kneader is reduced, and the dispersibility of the colorant and the charge control agent in the binder resin is reduced.

The present invention solves the above-mentioned conventional problems, and does not cause the mixture supplied to the continuous two-roll kneader to fall, and also allows the colorant and the charge control agent to be contained in the binder resin. An object of the present invention is to provide a toner kneading method and a toner manufacturing method capable of improving dispersibility, and an object of the present invention to provide an electrophotographic toner manufactured by using the toner manufacturing method.

[0022]

According to the present invention, a mixed powder containing at least a binder resin and a colorant is heated in advance and supplied to a continuous two-roll kneader. Then, it was configured to melt and knead.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is characterized in that a mixture containing at least a binder resin and a colorant is preliminarily heated and supplied to a continuous two-roll kneader to melt the mixture. This is a toner kneading method characterized by kneading.The supplied mixture can be melt-kneaded without dropping the supplied mixture, so that the loss of toner raw material is eliminated and the shear force is increased to increase the kneading. The dispersibility of the coloring agent and the like in the resin for adhesion can be improved. The kneaded material has a good dispersion state of the colorant and the like in the binder resin.

According to a second aspect of the present invention, there is provided the toner kneading method according to the first aspect, wherein the preheating temperature is equal to or higher than the glass transition point of the binder resin. Since the binder resin of the mixture can easily adhere to the roll, the supplied mixture can be more reliably melt-kneaded without dropping the mixture. Further, the loss of toner raw material is eliminated, and the dispersibility of the colorant and the like in the binder resin can be improved by increasing the shearing force. Therefore, the kneaded material disperses the colorant and the like in the binder resin. The condition is good.

According to a third aspect of the present invention, a mixture containing at least a binder resin and a colorant is melt-kneaded in advance, and the molten state is supplied to a continuous two-roll kneader to melt and knead the mixture. The mixture is melt-kneaded in advance, and is supplied in a molten state.Therefore, there is no drop as a mixture, and the mixture can be melt-kneaded. The dispersibility of the colorant and the like in the binder resin can be improved by increasing the shearing force, and the kneaded product has a good dispersion state of the colorant and the like in the binder resin.

According to a fourth aspect of the present invention, there is provided a toner kneading method according to the third aspect, wherein the mixture is previously melt-kneaded by a close-type kneader.
Since it is melt-kneaded in a sealed state in advance and supplied in a melted state, the melt-kneaded material does not fall and can be melt-kneaded.
The dispersibility of the colorant and the like in the binder resin can be improved by increasing the shearing force. The kneaded product has a good dispersion state of the colorant and the like in the binder resin.

According to a fifth aspect of the present invention, a mixture containing at least a binder resin and a colorant is melt-kneaded by the toner kneading method according to any one of the first to fourth aspects, and the melt-kneaded kneaded material is pulverized. This is a method for producing a toner characterized by classifying.The loss of toner raw materials is eliminated, and the dispersibility of a colorant and the like in a binder resin can be improved by increasing the shearing force. The dispersion state of the colorant and the like in the binder resin is good. Further, the yield in the toner manufacturing process can be improved, and a high-quality toner having a stable charge amount can be manufactured.

According to a sixth aspect of the present invention, there is provided an electrophotographic toner produced by using the toner producing method according to the fifth aspect, wherein a colorant or the like is well dispersed in a binder resin. In addition, the amount of charge is stable, problems such as fogging in printed images can be eliminated, and in the case of a color toner, deterioration in transmittance of an OHP film and smearing of an image can be prevented.

Hereinafter, embodiments of the present invention will be described.

(Embodiment 1) FIG. 1 is a view showing an outline of a continuous two-roll kneader, FIG. 1 (a) is a side view of the entire apparatus, and FIG. FIG. 1 (c) is a schematic cross-sectional view of the vicinity of the toner raw material supply section when the roll portion is viewed from above. The configuration of the continuous two-roll kneader according to the present embodiment will be described using a conventional technique. The description is omitted because it is the same as the continuous two-roll type kneader described above.

Next, a toner kneading method and a toner manufacturing method according to the present embodiment using the continuous two-roll kneader will be described.

Raw materials containing at least a binder resin and a colorant are mixed in a container rotary mixer such as a V blender or a high-speed stirring mixer such as a Henschel mixer, and the resulting mixture is mixed. The powder is quantitatively and continuously supplied to the toner raw material supply section 3 of the two-roll kneader 10 shown in FIG. 1 using a screw feeder or the like.

In the case of continuous supply, the mixed powder is heated and supplied. The heating is performed by hot air blowing or the like using a conventionally known heating device such as an electric oven, a panel heater, or a dryer. The heating of the mixed powder may be performed during the supply, or may be performed simultaneously with the supply of the mixed powder to the roll. Also,
It is preferable to attach the heating device such as the electric oven, panel heater, or dryer to an automatic supply device such as a screw feeder because heating and automatic supply can be efficiently performed.

Next, the mixture supplied to the toner material supply section 3 of the front roll 2 is heated by a heating medium supplied to a spiral pipe (not shown) inside the roll surface in the hollow portion of the roll. When heated, the binder resin melts and adheres to the surface of the front roll 2. At this time, since the mixed powder is heated in advance, it is melted at the moment when it adheres to the roll, so that the front roll 2
Adhere to

Here, the temperature of the heating medium supplied to each roll is set as follows. In the front roll 2, on the side of the toner raw material supply unit 3, the temperature is higher than the glass transition point of the binder resin and lower than the softening point, and on the side of the kneaded material discharge unit 4, the temperature is lower than the glass transition point of the binder resin. Is set. The temperature of the heat medium supplied to the back roll 1 is equal to or lower than the temperature of the heat medium on the side of the kneaded material discharge unit 4 of the front roll 2, preferably, the kneaded material discharge unit 4 of the front roll 2.
The temperature is set lower than the side temperature.

As a specific example of the heating medium, a front roll 2
The steam is used on the side of the toner raw material supply unit 3 and the cooling water is used on the side of the kneaded material discharge unit 4. Cooling water may be used for the back roll 1.

The method of setting the temperature of the heat medium includes a method of presetting the temperature of the heat medium itself before supply to the roll, such as a case of using steam or cooling water, and a method of setting the heat medium at a constant temperature. Is supplied to the roll, and the heating medium is heated in the roll and / or
Alternatively, any method such as a method of cooling and setting the temperature or a method of combining them may be used.

Next, the front roll 2 is not dropped.
As shown in FIG. 1 (c), the mixture adhered to is melt-kneaded by the front roll 2 and the back roll 1 rotating inside each other.

That is, the mixture which has been heated in advance and is supplied to the toner raw material supply section 3 of the front roll 2 is heated by the electric heating effect of the heat medium supplied to the front roll 2, whereby the binder resin is melted and melted. It adheres to the surface of the roll 2 and is caught by the rotation of the front roll 2 and the back roll 1.

The screw effect of the spiral groove 5 provided on the surface of the back roll 1 and the front roll 2 shown in FIGS. 1 (a) and 1 (b), It is transferred from left to right in FIG.

When the molten deposit is transferred and reaches near the center of the front roll 2, the temperature of the kneaded material discharge section 4 of the front roll 2 is set lower than that of the toner material supply section 3. The adhering matter is partially cooled, and while being kneaded by receiving a sudden compression force and a shearing force of the rotation of the roller in the gap between the rolls 1 and 2, is further transferred as a kneaded material to the kneaded material discharge unit 4. . In this way, the kneaded material is transferred while being continuously compressed and sheared between the rolls 1 and 2, whereby the colorant and the like are uniformly dispersed in the binder resin.

Here, the operating conditions of the continuous two-roll kneader will be described. The number of rotations of the roll is preferably 50 rpm or more in order to have a strong shearing force, and is preferably 150 rpm or less in order not to generate excessive heat and cut the molecular chain of the binder resin. Further, in order to continuously discharge the kneaded material, the kneaded material needs to be attached to the front roll 2 in the vicinity of the kneaded material discharge unit 4. It must be equal to or greater than the number.

The kneaded product thus obtained is cooled, coarsely pulverized by a cutter mill or the like, then finely pulverized by a jet mill pulverizer, and then coarsely and finely pulverized by a classifier such as an air-flow classifier. Is appropriately removed to obtain a desired particle size, and further through an external addition step of externally adding an additive as needed, to obtain a completed toner.

FIG. 2 is a process diagram of the toner manufacturing method according to the first embodiment, and schematically illustrates the flow of each process of the toner manufacturing method using the two-roll kneader described above. It is.

(Embodiment 2) Further, in the present invention, a mixed powder as a feed material is melt-kneaded in a closed kneader in advance, and a continuous two-roll kneader in a state where the melt-kneaded material is melted. Was also found to be an effective means of preventing the mixture from falling.

In the second embodiment, the configuration, operation, operating conditions, and the like of the continuous twin-roll kneader shown in FIG. 1 are basically the same as those described in the first embodiment. Therefore, detailed description is omitted here.

Also in the second embodiment, the first embodiment
Similarly to the above, raw materials containing at least a binder resin and a colorant are mixed by a container rotary mixer such as a V blender or a high-speed stirring mixer such as a Henschel mixer.

Next, the mixed powder, which is the obtained mixture, is melted and kneaded by a closed-type kneader, and the molten kneaded material is fed to the toner material supply section 3 of the continuous two-roll kneader 10 in a molten state. Supplied.

The closed-type kneader refers to a device capable of kneading in a closed state such that a kneaded material does not leak outside, such as a single-screw or twin-screw extruder or a pressure kneader. The mixture does not fall because it is in a closed state.

The kneaded material discharged from such a closed-type kneader is supplied to the toner material supply section 3 of the front roll 2 of the continuous two-roll type kneader 10 in a molten state. There is no drop of the mixed powder.
By increasing the shearing force, the dispersibility of the colorant and the like in the binder resin can be improved, and the kneaded material has a good dispersion state of the colorant and the like in the binder resin.

The kneaded product thus obtained is cooled, coarsely pulverized by a cutter mill or the like, then finely pulverized by a jet mill pulverizer, and coarse and fine powders are classified by a classifier such as an air flow classifier. Is appropriately removed to obtain a desired particle size, and further through an external addition step of externally adding an additive as needed, to obtain a completed toner.

FIG. 3 is a process chart of the toner manufacturing method according to the second embodiment. The flow of each process of the toner manufacturing method using the close type kneader and the two-roll type kneader described above is shown. It is a simplified illustration.

Next, the toner material used in the toner kneading method and the toner manufacturing method of the present invention will be described. The toner of the present invention comprises at least a binder resin and a colorant, and may further contain a charge control agent, various additives, and the like.

First, the following resins can be used as the binder resin.

Polyester resin, epoxy resin, polyol resin, styrene-acrylic resin, polyvinyl chloride, phenolic resin, phenol resin modified with natural resin,
Maleic acid resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, acrylic phthalate resin,
Polyvinyl acetate, silicone resin, polyurethane, polyamide resin, polyvinyl butyral, terpene resin, coumarone indene resin, polycarbonate, fluorine resin, aliphatic or aliphatic hydrocarbon resin, aromatic petroleum resin, modified rosin, paraffin, natural Waxes, synthetic waxes and the like can be mentioned, and these resins can be used alone or in combination of two or more.

Further examples include styrenes such as styrene, chlorostyrene, α-methylstyrene and vinylstyrene, monoolefins such as ethylene, propylene, butylene and isobutylene, vinyl acetate, vinyl propionate, vinyl benzoate and butyric acid. Vinyl esters such as vinyl, acrylic acid such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Alkyl ethers and methacrylic acid alkyl esters, vinyl methyl ether, vinyl ethyl ether, vinyl ethers such as vinyl butyl ether,
Examples include homopolymers or copolymers of vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropenyl ketone.

Typical examples thereof include polystyrene and poly-
Homopolymers of styrene such as p-chlorostyrene and polyvinyltoluene and substituted products thereof, styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-alkyl acrylate Ester copolymer, styrene-alkyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer Copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-acrylonitrile-indene copolymer, styrene-based copolymer such as styrene-maleic anhydride copolymer, polyethylene, ethylene-vinyl acetate copolymer Polymer, ethylene bi Ethylene copolymer of alcohol copolymer, and polypropylene.

These homopolymers or copolymers can be used alone or in combination of two or more.

Among the above binder resins, polyester resins have sharp melting suitability and have good fixability. Further, it is possible to improve the coloring property and the durability of the toner, which is particularly preferable.

The weight average molecular weight of the polyester resin is preferably 10,000 or more and 20,000 or less. That is, if it is less than 10,000, there is a problem that a so-called offset phenomenon occurs in which the toner is transferred to the fixing roller in the toner fixing step.
If it is larger than this, there is a problem that the meltability is deteriorated and a fixing failure occurs, which is not preferable.

Further, as the colorant used in the present invention, any organic or inorganic pigment or dye is used.

Pigments such as disazo pigments, insoluble azo pigments, azo lake pigments, copper phthalocyanine pigments and the like can be used.
Dyes such as anthraquinone dyes, xanthene dyes, methine dye basic dyes and oil-soluble dyes can be used.
These pigments and dyes can be used alone or in combination of two or more.

The pigments include phthalocyanine blue, indanthrene blue, peacock blue, fast sky blue, induslen blue, aniline blue, calcoil blue, ultramarine blue, permanent red, watching red calcium salt, brilliant carmine , Lake Red, Rose Bengal, Naphthol Yellow, Hansa Yellow, Rhodamine Yellow, Hansa Yellow, Permanent Yellow, Benzidine Yellow, Naphthol Yellow, Chrome Yellow, Quinoline Yellow, Carbon Black, Aniline Black, Acetylene Black, Lamp Black, Alizarin Lake, Bengala , Rhodamine lake, permanent orange, pyrazolone orange, benzine orange, malachite green oki Rate, quinacridone, fast violet, methyl violet lake, as a blue dye or pigment of copper phthalocyanine and derivatives thereof,
C. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 16, red or red pigments include C.I. I. Pigment Red 5, C.I. I. Pigment Red 3, C.I. I. Pigment Red 2, C.I. I. Pigment Red 6, C.I. I. Pigment Red 7, C.I. I. Pigment Red 57, C.I.
I. Pigment Red 122, C.I. I. Pigment Red 9, C.I. I. Pigment Red 48, C.I. I. Pigment Red 48: 3, C.I. I. Pigment Red 53:
1, C.I. I. Pigment Red 112, C.I. I. Pigment Red 149, C.I. I. Pigment Red 170,
C. I. Pigment Red 168, C.I. I. Pigment Red 188, C.I. I. Pigment Red 194, C.I.
I. Pigment Red 175, C.I. I. Pigment Red 208, C.I. I. Pigment Red 187, C.I. I.
Pigment Red 57: 1, C.I. I. Pigment Red 81, C.I. I. Pigment Red 122, C.I.
I. Pigment Red 49: 1, benzimidazolone monoazo pigments such as C.I. I. Pigment Yellow 151, C.I. I. Pigment Yellow 154, C.I.
I. Pigment Yellow 156, C.I. I. Pigment Yellow 120, C.I. I. Pigment Yellow 17
5. As an acetoacetic acid arylamide-based disazo yellow pigment, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 83, isoindolinone pigments such as C.I. I. Pigment Yellow 110, C.I. I. Pigment Yellow 109, C.I. I. Pigment Yellow 137, C.I. I. Pigment Yellow 173, acetoacetic arylamide monoazo yellow pigment,
C. I. Pigment Yellow 1, C.I. I. Pigment Yellow 3, C.I. I. Pigment Yellow 74,
C. I. Pigment Yellow 97, C.I. I. Pigment Yellow 98 can be used.

As the dye, C.I. I. Direct Blue 1, C.I. I. Direct Blue 2, C.I. I. Acid Blue 9, C.I. I. Acid Blue 15, C.I. I.
Basic Blue 3, C.I. I. Basic Blue 5,
C. I. Modant Blue 7, C.I. I. Direct Red 1, C.I. I. Direct Red 4, C.I. I. Acid Red 1, C.I. I. Basic Red 1, C.I. I. Basic Red 12, C.I. I. Modern Red 30,
C. I. Solvent Red 49, C.I. I. Solvent Red 52, C.I. I. Solvent Red 109, C.I. I.
Solvent Red 58, C.I. I. Solvent Red 8,
C. I. Solvent Yellow 19, C.I. I. Solvent Yellow 77, C.I. I. Solvent Yellow 7
9, C.I. I. Disperse Yellow 164 can be used.

Next, as the charge control agent, the following charge control agents can be used.

Examples of the charge control agent as the negatively chargeable toner include a chromium-zinc-aluminum-boron complex or a salt compound of salicylic acid or a derivative thereof, and a chromium-zinc-aluminum-boron complex or a salt compound of benzylic acid or a derivative thereof. , Tetraphenylborate, chromium azo complex dye, iron azo complex dye, cobalt azo complex dye, chromium zinc of naphtholic acid or its derivative
Surface active agents such as aluminum-boron complex or salt compound, long-chain alkyl carboxylate, and long-chain alkyl sulfonate.

The charge control agent as a positively chargeable toner is cetyltrimethylammonium bromide, quaternary ammonium salt, N, N-dialkylaminoalkyl (meth) acrylates, N, N-dialkylaminoalkyl (meth) acrylate. Radical polymerizable copolymers obtained by copolymerizing monomers having a nitrogen-containing functional group of acrylamides, nigrosine dyes and derivatives thereof, triphenylmethane derivatives, quaternary phosphonium salts, quaternary pyridinium salts, guanidine salts, derivatives such as amidine salts And the like.

Further, the toner of the present invention may contain various additives as necessary.

As additives, fluidity improvers, release agents,
Lubricant, fixing aid, cleaning improver, conductive material,
Examples of the filler include reinforcing fillers such as extenders and fibrous substances, antioxidants, antioxidants, and anti-offset agents. The additives are added to satisfy various characteristics required for the toner or to improve the characteristics.

The additives include oxides,
Multiple oxides, inorganic oxides, metal oxides, metals, silicon compounds, carbon, carbon compounds, fullerenes, boron compounds, carbides, nitrides, ceramics, and the like, and examples of the inorganic oxides include silica, titania, alumina, Zirconia,
Examples include zinc oxide, magnesium oxide, cerium oxide, strontium titanate, iron oxide, copper oxide, and tin oxide.

Further, various waxes may be added, such as fluororesin fine particles, silicone resin fine particles, higher fatty acids such as stearic acid, and metal salts thereof such as zinc stearate and aluminum stearate.

Examples of the fluidity improver include inorganic oxides such as silica, alumina, titania, and zirconia. The surface of these inorganic oxides is a silane compound having a nitrogen element-containing substituent such as aminosilane, or amino-modified. It is preferable that the hydrophobic treatment is performed with a silicone oil having a substituent containing a nitrogen element such as silicone oil. For example, hydrophobic silica can be used. This fluidity improver is preferably externally added to the surface of the toner.

As the release agent, low molecular weight polypropylene,
Low molecular polyethylene, or waxes such as micro stalin wax, carnauba wax, sasol wax, paraffin wax and the like.

Further, wax such as polyolefin, polyethylene and polypropylene also functions as an anti-offset agent.

Examples of the lubricant include Teflon, zinc stearate, polyvinylidene fluoride and the like. Low molecular weight polyethylene, low molecular weight polypropylene and the like can be added as a fixing aid.

These additives can be used alone or in combination of two or more, if necessary, and are added internally or externally according to the purpose.

[0077]

Next, the present invention will be described in detail with reference to examples of the present invention and comparative examples. The present invention is not limited at all by the following Examples and Comparative Examples.

The formulation of the toner used in this example is shown below. Binder resin 100 parts by weight of polyester resin (glass transition point: 58 ° C.) I. Pigment Red 57: 1 5 parts by weight Charge control agent Zinc salicylate derivative 5 parts by weight (Example 1) 5 kg of raw material weighed at the above-mentioned ratio was mixed with a Henschel mixer at 2800 rpm for a blade speed of 20 minutes. To obtain a mixed powder.

This mixed powder was put into a screw feeder having a panel heater in the hopper, and heated to 65 ° C. The heated mixed powder was converted into a continuous type 2 shown in FIG.
A fixed amount was supplied to the roll-type kneader at a rate of 15 kg / hour to obtain a kneaded material. The operating conditions of the continuous two-roll kneader are as follows. Roll rotation speed Front roll rotation speed: 60 rpm Back roll rotation speed: 50 rpm Heat medium temperature inside the roll Front roll: toner material supply side; 100 ° C., kneaded material discharge side; 40 ° C. Back roll: 30 ° C. After cooling, the product was coarsely pulverized by a bantam mill having a screen of φ2 mm, finely pulverized by an I-type jet mill, and further fine and coarse powders were removed by an elbow jet classifier to obtain a toner having a weight average particle diameter of 9.5 μm. And

The average particle size was measured using a Coulter Counter TA-
The measurement was performed using a type II (manufactured by Coulter).

Further, 1 part by weight of hydrophobic silica was added to 100 parts by weight of the toner particles and mixed and adhered using a Henschel mixer to obtain a magenta toner of Example 1.

(Example 2) Using the same formulation as in Example 1,
A mixed powder was obtained using a Henschel mixer under the same processing conditions as in Example 1. The mixed powder was charged into a twin-screw extruder at a speed of 15 kg / hour and kneaded at 100 ° C. The temperature of the kneaded material coming out of the twin screw extruder is 90 ° C
Met. This kneaded material was directly supplied to a continuous two-roll kneader in a molten state and kneaded. The operating conditions of the continuous two-roll kneader were the same as in Example 1.

Further, the kneaded product was subjected to the same steps as in Example 1 to obtain a magenta toner of Example 2.

(Comparative Example 1) In Example 1, except that the heating of the mixed powder was not carried out, the composition and conditions were the same as in Example 1, and the same steps as in Example 1 were carried out. Thus, a magenta toner of Comparative Example 1 was obtained.

Comparative Example 2 The procedure of Example 1 was repeated except that the mixed powder was not heated, and the temperature of the heating medium in the roll of the continuous two-roll kneader was changed as follows. The magenta toner of Comparative Example 2 was obtained through the same prescription and conditions as in Example 1, and through the same steps as in Example 1. Heating medium temperature in the roll Front roll: 130 ° C. on the side of the toner raw material supply unit; discharge side of the kneaded material: 50 ° C. Back roll: 40 ° C. (Comparative Example 3) A magenta toner of Comparative Example 3 was obtained through the same prescription and conditions as in Example 2, except that the kneading was performed only with a twin screw extruder.

Here, in Examples 1 and 2 and Comparative Examples 1 and 2, the amount of mixture falling when the mixture was supplied to a continuous two-roll kneader was measured. The test results are shown in (Table 1).

[0087]

[Table 1]

In Examples 1 and 2 and Comparative Example 2, the continuous
There is no drop amount of the kneaded material supplied to the roll-type kneader,
Alternatively, the amount was extremely small, and good results were obtained. In particular, in Example 2, no drop occurred, which was extremely good. Compared with these, in Comparative Example 1, about 30% of the mixture fell with respect to the supply amount, and the productivity was extremely poor.

Next, the toners of Examples 1 and 2 and Comparative Examples 1 to 3 were charged into a non-magnetic one-component developing device, and a continuous printing life test of 10,000 sheets was performed.

The test results are also shown in (Table 1).

Here, the evaluation method and evaluation criteria in the evaluation items of (Table 1) will be described.

The image density stability is for confirming the change over time in the printed image density.
The image density of the sheet is measured with a Macbeth densitometer (manufactured by Macbeth). Then, evaluation was made based on the difference in the concentration change.

Fogging is a phenomenon of toner flying to a non-image portion, and the degree of contamination of the non-image portion was visually determined.

The solid followability was evaluated by visually checking whether or not the image was blurred in the printing direction when a full solid image was printed.

The OHP transparency was evaluated by printing a halftone image having a printing rate of 50% on an OHP sheet and projecting the image projected by an overhead projector.

The evaluations in all the evaluation items were as follows: ○, Δ,
The evaluation was based on a three-point scale of ×, and the evaluation criteria were: ：: good,
Δ: acceptable, ×: defective.

From the results of the life test, the toners obtained in Examples 1 and 2 and Comparative Example 1 have stable image densities, good fogging reduction, good solid image followability, and good OHP transparency. Met. Further, the stability of the toner charge amount on the developing roller (toner transport roller) of the non-magnetic one-component developing device is good. However, the toners obtained in Comparative Examples 2 and 3 were insufficient in any of the print evaluation items.

From the results of the mixture falling amount test and the toner life test, it was found that the toners according to Examples 1 and 2 were high in productivity without dropping the mixture, and were high quality toner.

[0099]

As described above, when a continuous two-roll type kneader is used, in a conventional toner kneading method, if the roll surface temperature is increased to suppress the drop amount of the supply mixture,
Poor dispersibility of the colorant and the like to the binder resin, good image characteristics can not be obtained, on the contrary, in order to obtain good image characteristics,
In order to improve the dispersibility of the colorant and the like, there was a disadvantage that the amount of the supplied mixture dropped and the productivity became poor, but in the present invention, the continuous two-roll kneader was used. The dispersibility of the colorant, charge control agent, etc. in the binder resin can be improved without dropping the supplied mixture, so that the yield is improved without loss of raw materials, and the productivity is reduced at low cost. It is possible to provide a toner kneading method and a toner manufacturing method capable of improving the quality of a toner. Further, a high-quality electrophotographic toner manufactured by using the toner manufacturing method can be provided.

[Brief description of the drawings]

FIG. 1A is a side view of the entire apparatus. FIG. 1B is a view of a roll portion as viewed from above. FIG.

FIG. 2 is a process chart of a toner manufacturing method according to the first embodiment.

FIG. 3 is a process chart of a toner manufacturing method according to a second embodiment.

FIG. 4 is a process diagram of a conventional toner manufacturing method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Back roll 2 Front roll 3 Toner material supply part 4 Kneaded material discharge part 5 Spiral groove 6 Heat medium supply and discharge part 7 Heat medium supply and discharge part 8 Roll drive motor 9 Roll drive motor 10 Continuous two-roll kneader

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideaki Iwanaga 1006 Kadoma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. Terms (reference) 2H005 AA21 AB04 EA03

Claims (6)

[Claims] 1. A toner kneading method comprising: preliminarily heating a mixture containing at least a binder resin and a colorant, supplying the mixture to a continuous two-roll kneader, and melt-kneading the mixture. 2. The method according to claim 1, wherein the preheating temperature is equal to or higher than a glass transition point of the binder resin.
The toner kneading method described in the above. 3. A toner kneading method characterized in that a mixture containing at least a binder resin and a colorant is melt-kneaded in advance, and supplied in a molten state to a continuous two-roll kneader to be melt-kneaded. . 4. The mixture is mixed by a closed kneader.
4. The method according to claim 3, wherein the toner is kneaded in advance. 5. A mixture containing at least a binder resin and a colorant is melt-kneaded by the toner kneading method according to any one of claims 1 to 4, and the melt-kneaded mixture is pulverized and classified. Toner manufacturing method. 6. An electrophotographic toner manufactured by using the toner manufacturing method according to claim 5.