JP2002091072A - Method for producing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing toner which enables easily controlling average particle size and enables efficiently producing the toner having a sharp particle size distribution. SOLUTION: This method for producing toner comprises at least a toner granulation process and a polymerization process, therein, the toner granulation process is a process where a polymerizable monomer composition and a dispersion stabilizer are included in a granulation vessel 1, are dispersed into a liquid dispersing medium which is substantially incompatible with the polymerizable monomer composition and are granulated, the granulation vessel is equipped with a stirring device having a high shearing force therein, and there is relation; 0.9>D2/D1>0.3 and 0.1<H/D1<0.6, wherein, D1 is the major axis of a rotating body formed when a stirring vane is rotated, D2 is the miner axis thereof and H is the height thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a toner used in a recording method such as an electrophotographic method, an electrostatic recording method, and a toner jet recording method.

[0002]

2. Description of the Related Art Electrophotography is disclosed in U.S. Pat.
A number of methods are known as described in the specification of JP-A-691, and generally, a photoconductor made of a photoconductive material is used to form an electric latent image on the photoconductor by various means. Then, the latent image is developed using a toner to form a visible image, and if necessary, the toner image is transferred to a transfer material such as paper, and then the toner image is fixed on the transfer material by heat or pressure. To obtain a copy or print. Various methods have been conventionally proposed as a method of developing using a toner or a method of fixing a toner image.

Conventionally, toners used for these purposes are:
Generally, a colorant comprising a dye or a pigment is melt-kneaded in a thermoplastic resin, and after uniformly dispersed, finely pulverized by a fine pulverizer, and the finely pulverized material is classified by a classifier to obtain a desired particle size. It has been manufactured to have.

Although this method can produce fairly good toners, it has certain limitations, namely, the range of choice of toner materials. For example, the toner coarse powder must be sufficiently brittle and capable of being pulverized with economically feasible manufacturing equipment. However, if the toner coarse powder is made brittle to satisfy these requirements, when the toner coarse powder is actually finely pulverized at a high speed, the particle size range of the formed particles tends to be widened, and in particular, it is relatively large. There is a problem that the fine particles are contained in the finely pulverized material in a proportion. Further, the toner obtained from such a highly brittle material is liable to be further pulverized or powdered in a developing device such as a copying machine. Further, in this method, it is difficult to completely and uniformly disperse solid fine particles such as a colorant in a resin, and depending on the degree of the dispersion,
Careful attention must be paid to the dispersing of the colorant, as this may cause an increase in fog at the time of image formation, a decrease in image density, and poor color mixing or transparency. Further, exposure of the coloring agent to the fracture surface of the pulverized particles may cause a change in development characteristics.

On the other hand, in order to overcome the problems of the toner caused by these pulverization methods, Japanese Patent Publication Nos. 36-10231, 43-10799 and 51-14895 are disclosed.
Various polymerization toners and a method for producing the same have been proposed, including the suspension polymerization toner disclosed in Japanese Patent Application Laid-Open Publication No. H11-163873. For example,
In the suspension polymerization method toner, a polymerizable monomer, a colorant and a polymerization initiator, and further, if necessary, a crosslinking agent, a charge control agent, and other additives are uniformly dissolved or dispersed to form a monomer composition. Thereafter, the monomer composition is a continuous phase containing a dispersion stabilizer,
For example, toner particles having a desired particle size are obtained by dispersing in an aqueous phase using a suitable stirrer and simultaneously performing a polymerization reaction.

In this method, since no pulverizing step is included, the toner does not need to be brittle, a soft material can be used as the resin, and the colorant is not exposed to the particle surface. There is an advantage that a toner having uniform triboelectricity can be obtained. In addition, since the particle size distribution of the obtained toner is relatively sharp, the classification step can be omitted, or even if the classification is performed, the toner can be obtained in high yield. Further, since a large amount of a low softening point substance can be included in the toner as a release agent, there is an advantage that the obtained toner has excellent offset resistance.

[0007]

However, due to the characteristics of the production method of the polymerization method toner, in order to obtain toner particles having a desired particle diameter and a sharp particle size distribution in the granulation step, this granulation step is extremely difficult. Is important. Conventionally, various agitation devices, emulsification devices, and the like have been used in this granulation process, but there is a problem that it is extremely difficult to obtain fine, uniform and sharp polymer particles having a particle size distribution. In addition, in this granulation step, the liquid may stay in the granulation container, and in such a case, the granulated droplets will coalesce to form polymer particles having a broad particle size distribution. Problem.

[0008] In order to improve the above list, droplets (particles) of the polymerizable monomer composition are granulated by a granulator as described in JP-A-8-305084. There are known ways to do this. In this granulation method, granulation is performed by the action of shearing force, collision force, pressure fluctuation, cavitation, and potential core generated by a stirring blade rotating at high speed and a screen surrounding the stirring blade. From this, in order to obtain a desired sharp toner particle size distribution, a sufficient flow in the granulation container, specifically, a large suction flow from the upper and lower portions of the screen is generated by rotating the stirring blade, and It is necessary to generate a large jet from the side.

However, in this granulation method, the shape of the stirring blade rotating at a high speed has a shape that particularly hinders the suction flow from the lower part of the screen.

More specifically, a shape having a relationship of D2 / D1 <0.3 (long diameter of the stirring blade: D1, short diameter D2) and H / D1> 0.6 (height of the stirring blade: H) is used. In this configuration, the lower part of the tip of the stirring blade works effectively due to the rotation of the stirring blade.
However, when the lower part of the stirring blade operates, a jet flow is formed downward from the vicinity of the lower end of the stirring blade, and the flow in the granulation container is easily formed from the lower part of the screen due to the movement of the jet flow.

If a flow spouting from the lower part of the screen is formed, the suction force to the screen, especially the suction flow from the lower part of the screen is hindered, and the shearing force and the collision force due to the jet flow from the side face are weakened. There was a strong tendency for the liquid to stay in the granulation container. In such a case, the granulated droplets coalesce, resulting in a problem that the polymer particles have a broad particle size distribution, and a problem that a desired particle size distribution of the toner cannot be obtained. I was

In particular, when the granulation is carried out in a batch process in which the long diameter D1 of the stirring blade and the inside diameter D of the granulation container have a relationship of 0.05 <D1 / D <0.35, the pump is operated. The granulation operation requires a large flow in the granulation vessel, and the jet flow from the screen side requires a larger flow compared to continuous processing in which the monomer composition and the dispersant are supplied via granulation. Therefore, when a stirring blade having a shape of D2 / D1 / D <0.3 and a shape of H / D1> 0.6 is used, the liquid tends to stay in the granulation container, and this is a problem. In such a case, the granulated droplets are united, resulting in a problem that polymer particles having a broad particle size distribution are generated, and a problem that a desired toner particle size distribution cannot be obtained occurs. I was

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for producing a toner which can easily control the average particle diameter and efficiently produce a toner having a sharp particle size distribution in the production of a toner by a polymerization method. . Another object of the present invention is to provide a method for producing a toner having excellent fixability.

[0014]

The above object is achieved by the present invention described below. That is, the present invention provides a method for producing a toner including at least a toner particle granulating step and a polymerization step, wherein the toner particle granulating step contains a polymerizable monomer composition and a dispersion stabilizer in a granulation container. And the step of granulating by dispersing in a liquid dispersion medium that is substantially incompatible with the polymerizable monomer composition,
In the granulation container, a stirring device having a high shearing force is provided, the stirring device includes a stirring blade that rotates at high speed and a stirring chamber, and a rotating body formed when the stirring blade rotates. When the major axis is D1, the minor axis is D2, and the height is H, 0.9> D2 / D1> 0.3 and 0.1 <H / D1
<0.6, which is a method for producing a toner. Here, the stirring device further includes a stirring blade that rotates at high speed and a stirring chamber, and the liquid fluid to the stirring chamber is configured to be sucked from above and below the stirring chamber and to be ejected from the side surface. Is desirable.

As a result of intensive studies, the present inventors have found that a polymerizable monomer composition is granulated in a granulation container to obtain droplet particles having a sharp particle size distribution. What,
The present inventors have found that it is very important to smoothly suck a liquid substance present in the container and to increase the jet flow from the stirring chamber. The method for producing the toner of the present invention having the above configuration is based on such knowledge.

[0016]

Next, the present invention will be described in more detail with reference to preferred embodiments.

FIGS. 1, 2 and 3 show schematic sectional views of a preferred granulating apparatus used in the present invention. In FIG.
1 is a granulation container, 2 is a stirrer, 3 is a stirrer shaft for driving the stirrer, 7 is a jacket, and 8 is a liquid surface of a liquid material. FIG. 2 is an enlarged sectional view of the stirring device in FIG. 1, wherein 4 is a stirring blade, 5 is a screen,
Reference numeral 6 denotes a stirring chamber. FIG. 3 is a sectional view of the stirring blade 4.
As shown in FIG. 3, when the length of the rotating body formed when the stirring blade rotates is D1, the short diameter is D2, and the height is H, the stirring blade 4 is 0.9> D2 / D1> 0. 0.3 and 0.1 <H / D1
It is designed to have a relationship of <0.6.

In such a granulating and stirring apparatus, the dispersion comprising the polymerizable monomer composition and the liquid dispersion medium forms a smooth suction flow from the upper portion of the stirring device 2 and the lower portion of the stirring device 2. After entering the stirring chamber 6 and being stirred by the strong shearing force, collision and turbulence generated between the stirring blade 4 and the screen 5 rotating at high speed, the monomer composition particles on the order of microns are formed. From the granulation vessel. In the stirring device having the above configuration, the shape of the stirring blade, the mesh diameter of the screen and the gap between the stirring blade and the screen can be changed, and the viscosity of the monomer composition and the finally desired monomer composition can be changed. Any suitable form can be used depending on the particle diameter and the like.

In particular, when granulation is performed by batch processing such that the major axis D1 of the stirring blade and the internal diameter D of the granulation container have a relationship of 0.05 <D1 / D <0.35,
The polymerizable monomer composition in the granulation container is made uniform compared to the case where the polymerizable monomer composition and the liquid dispersion medium are supplied to the upper portion of the screen via a pump to perform granulation by continuous processing. However, since a strong shearing force and an impact force generated between the stirring blade 4 and the screen 5 are required, a dispersion comprising a polymerizable monomer composition and a liquid dispersion medium is required. Forms a smooth suction flow from the upper portion of the stirring device 2 and the lower portion of the stirring device 2, enters the stirring chamber 6, and removes strong shearing force and impact force generated between the stirring blade 4 and the screen 5 rotating at high speed. It is very important that it be squirted as it occurs.

In the granulation step, usually, in order to perform granulation at a certain temperature, the granulation container is formed into a jacket structure, and hot water or steam, and if necessary, cold water or the like is flowed through the jacket, and the inside of the container is cooled. Preferably, temperature control is performed.

In such a granulating and stirring device, the flow of the fluid is sucked into the stirring device from the upper and lower portions of the stirring device and jets to the side. In this case, the polymerizable monomer composition is fed into the stirring chamber very efficiently, and monomer composition particles having a sharp particle size distribution can be obtained.

However, 0.9> D2 / D1> 0.3 and 0.1 <H / D1
If the stirring blade shape does not satisfy <0.6, the high-speed rotation of the stirring blade causes the flow of fluid from the upper portion to the lower portion of the stirrer to become a mainstream, thereby obstructing the suction flow from the lower portion of the stirrer and ejecting the fluid from the side surface. When the flow is reduced or the stirring area of the stirring blade is reduced, the amount of protrusion from the side of the stirring device is extremely reduced, so that necessary shearing force and impact force cannot be obtained.

In such a case, there is a problem that the granulated droplets are united, and the particle size distribution of the obtained particles is wide.

On the other hand, according to the present invention, the major axis of the rotating body formed when the stirring blade rotates is D1, and the minor axis is D1.
2. When the height is H, 0.9> D2 / D1> 0.3 and 0.1 <H / D1
<0.6 / D1 / D1> 0.4 and 0.2 <H / D1
<0.5, and the stirring device includes the stirring blade that rotates at a high speed and a stirring chamber, and the liquid fluid to the stirring chamber is smoothly supplied from above and below the stirring chamber. This problem is solved because it is constituted so as to be sucked out and ejected from the side surface, thereby producing a polymerized toner.

Further, when granulation is usually performed, the polymerizable monomer composition is charged into a granulation container charged with a liquid dispersion medium incompatible with the monomer composition and dispersed. Perform granulation. At this time, it is important that the polymerizable monomer composition is sufficiently mixed into the dispersion medium, but as in the present invention, the major axis of the rotating body formed when the stirring blade rotates is D1, and the minor axis is Is D2 and the height is H, 0.9> D2 / D1> 0.3 and 0.1 <H / D1
A stirring blade having a relationship of <0.6 is used, and more preferably, 0.7> D2 / D1> 0.4 and 0.2 <H / D1.
Since it has the stirring blade having a relationship of <0.5, it can be supplied very smoothly.

The control of the particle size of the obtained particles is as follows:
Usually, it is carried out based on the amount of the dispersion stabilizer used and the rotation speed of the stirring blade. As a result of intensive studies, the maximum peripheral speed of the stirring blade
It is preferable to control the tip of the blade at 15 to 45 m / sec from the viewpoint of sharpening the particle size distribution of the obtained particles. At a peripheral speed of less than 15 m / sec, it is difficult to reduce the droplet particle size. At a peripheral speed of more than 45 m / sec, a large number of extremely fine particles unsuitable for use as a toner are generated, and Becomes wider. Further, it is more preferable to control the peripheral speed of the tip of the blade to 17 to 40 m / sec.

The value of D1 / D, which is the ratio of the major diameter D1 of the stirring blade to the inner diameter D of the granulation vessel, is a very important factor in achieving uniform stirring in the vessel. That is, D1 /
If D is small, sufficient stirring cannot be obtained, and if D1 / D is too large, the collision force between the flow of the fluid ejected from the side of the stirring device and the inner wall of the container becomes large, causing turbulent flow or ejection. It is not preferable because it hinders the jetting amount. Then, as a result of the study by the present inventors, D1 / D
Is preferably in the range of 0.05 to 0.35, and more preferably 0.1
It has been found that a range of 0 to 0.30 is more preferable.

Furthermore, in the case of producing a toner having a core / shell structure and a shell portion formed by polymerization, and having both fixing property and blocking resistance, a low softening point substance is contained in each toner particle. Must be present at the same ratio, but in this regard, control of the particle size distribution during granulation is also important. In the production method of the present invention, such a problem can be solved because the particle size distribution of the droplet particles of the polymerizable monomer composition at the time of granulation can be sharpened.

As the main component of the core portion, a substance having a low softening point is preferable, and a compound having a main maximum peak value of 40 to 90 ° C. measured according to ASTM D3418-8 is preferable. If the maximum peak is less than 40 ° C., the self-cohesive force of the low softening point substance becomes weak, and as a result, the high-temperature offset resistance during the transfer of the toner image becomes weak, which is not preferable. on the other hand,
If the maximum peak exceeds 90 ° C., the fixing temperature of the toner is undesirably high. Further, if the temperature of the maximum peak value is high, a substance having a low softening point is mainly deposited during granulation, which is not preferable because the suspension system is hindered.

In the present invention, for measuring the temperature of the maximum peak value of the low-melting substance, for example, DS manufactured by Perkin Elemer Co., Ltd.
C-7 is used. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the heat quantity correction uses the heat of fusion of indium. An aluminum pan was used as a sample, an empty pan was set as a control, and the measurement was performed at a heating rate of 10 ° C./min.

Specific examples of the low-melting substance include paraffin wax, polyolefin wax, Fischer-Tropsch wax, amide wax, higher fatty acid, ester wax, derivatives thereof, and graft / block compounds thereof. it can. Also,
The low softening point substance is preferably added to the toner in an amount of 5 to 30% by mass. If the amount is less than 5% by mass, sufficient toner fixability cannot be obtained, and if the amount exceeds 30% by mass, coalescence of toner particles is likely to occur during granulation even in production by a polymerization method, and the particle size distribution is wide. The toner was easily formed and was not suitable for the present invention.

As a specific method for encapsulating the low softening point substance, the polarity of the material in the aqueous medium is set to be smaller for the low softening point substance than for the main monomer, and a small amount of a large polar resin or By adding a monomer, a toner having a so-called core / shell structure in which a material having a low softening point is coated with an outer shell resin can be obtained. The particle size distribution and the particle size of the toner can be controlled by changing the type or amount of the hardly water-soluble inorganic salt or dispersant that acts as a protective colloid, or by using mechanical device conditions such as the peripheral speed of the rotor and the number of passes. The toner of the present invention having a predetermined particle size distribution can be obtained by controlling the stirring conditions such as the shape of the stirring blade, the shape of the container, and the solid content concentration in the aqueous solution.

As a specific method for measuring the tomographic plane of the toner in the present invention, the toner is obtained by sufficiently dispersing the toner in an epoxy resin curable at room temperature and then curing it in an atmosphere at a temperature of 40 ° C. for 2 days. Cured product, ruthenium tetroxide,
After dyeing with osmium tetroxide, if necessary, a flaky sample was cut out using a microtome with diamond teeth, and the tomographic morphology of the toner was observed using a transmission electron microscope (TEM). . In the present invention, it is preferable to use a ruthenium tetroxide dyeing method in order to give a contrast between materials by utilizing a slight difference in crystallinity between the low softening point substance used and the resin constituting the outer shell. .

The polymerizable monomers used in the present invention include styrene monomers such as styrene, o (m-, p-)-methylstyrene and m (p-)-ethylstyrene; Methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, (meth) acrylic acid (Meth) acrylate monomers such as behenyl, 2-ethylhexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate; butadiene, isoprene, cyclohexene, (meth) acrylonitrile And ene monomers such as acrylamide are preferably used.

These may be used alone or generally in the published Polymer Handbook, 2nd edition III-P139-192.
Monomers are appropriately mixed and used so that the theoretical glass transition temperature (Tg) described in (John Wiley & Sons) indicates 40 to 80 ° C. When the theoretical glass transition temperature is lower than 40 ° C., problems occur in terms of the storage stability of the toner and the durability stability of the developer. On the other hand, when the theoretical glass transition temperature exceeds 80 ° C., the fixing point is increased. In the case of (1), the color mixture of each color toner is insufficient and the color reproducibility is poor, and the transparency of the OHP image is remarkably reduced.

The molecular weight of the outer shell resin of the toner having a core / shell structure is measured by GPC (gel permeation chromatography). As a specific GPC measurement method, the toner is extracted in advance using a Soxhlet extractor with a toluene solvent for 20 hours, and then toluene is distilled off using a rotary evaporator. Further, the substance having a low softening point is dissolved. A sample obtained by adding an organic solvent incapable of dissolving the shell resin, for example, chloroform, and sufficiently washing the solution, and then filtering the solution dissolved in THF (tetrahydrofuran) through a solvent-resistant membrane filter having a pore diameter of 0.3 μm. Using Waters 150C,
The column configuration is A-801, 802, 803, manufactured by Showa Denko
804, 805, 806, and 807 are linked, and the molecular weight distribution can be measured using a standard polystyrene resin calibration curve. The number average molecular weight (Mn) of the obtained resin component is 5,000.
１，1,000,000, weight average molecular weight (Mw)
And the number average molecular weight (Mn) ratio (Mw / Mn) is 2 to 1
An outer shell resin having a value of 00 is preferred for the present invention.

In the present invention, when a toner having a core / shell structure is produced, a polar resin may be further added in addition to the outer shell resin in order to incorporate a low softening point substance into the outer shell resin. Particularly preferred. As the polar resin used in the present invention, a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a saturated polyester resin,
Epoxy resins are preferably used. It is particularly preferable that the polar resin does not contain an unsaturated group capable of reacting with a shell resin or a monomer in the molecule. If a polar resin having an unsaturated group is included, a crosslinking reaction occurs with the monomer forming the outer shell resin layer. It is not preferable because it is disadvantageous.

In the present invention, an outermost shell resin layer may be further provided on the surface of the toner. The glass transition temperature of the outermost resin layer is designed to be equal to or higher than the glass transition temperature of the outer resin layer in order to further improve blocking resistance, and that the outermost resin layer is crosslinked so as not to impair fixability. Is preferred. It is preferable that the outermost resin layer contains a polar resin and a charge control agent in order to improve the chargeability.

The method for providing the outermost shell layer is not particularly limited, but includes, for example, the following method.

In the latter half or after the end of the polymerization reaction, if necessary, a monomer in which a polar resin, a charge controlling agent, a cross-linking agent, etc. is dissolved or dispersed is added to the reaction system, and the monomer is adsorbed on polymer particles.
A method in which polymerization is performed by adding a polymerization initiator.

If necessary, a polar resin, a charge control agent,
A method in which emulsion polymerized particles or soap-free polymerized particles comprising a monomer containing a crosslinking agent or the like are added to the reaction system, aggregated on the surface of the polymerized particles, and, if necessary, fixed by heat or the like.

If necessary, a polar resin, a charge control agent,
A method in which emulsion polymerized particles or soap-free polymerized particles comprising a monomer containing a crosslinking agent or the like are mechanically fixed to the surface of toner particles in a dry manner.

The colorant used in the present invention is a black colorant which is prepared by using carbon black, a magnetic substance, and the following yellow / magenta / cyan colorants as black colorants.

Examples of the yellow colorant include condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
A compound represented by an azo metal complex, a methine compound or an allylamide compound is used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 6
2, 74, 83, 93, 94, 95, 109, 110,
111, 128, 129, 147, 168 and the like are preferably used.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specifically, C.I.
I. Pigment Red 2, 3, 5, 6, 7, 23, 4
8: 2, 48: 3, 48: 4, 57: 1, 81: 1, 1
44, 146, 166, 169, 177, 184, 18
5, 202, 206, 220, 221 and 254 are preferably used.

As the cyan coloring agent used in the present invention, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds and the like can be used. Specifically, C.I. I. Pigment Blue 1,
7, 15, 15: 1, 15: 2, 15: 3, 15: 4,
60, 62, 66, etc. are preferably used.

These colorants can be used alone or as a mixture, or in the form of a solid solution.

In the case of a color toner, the colorant used in the present invention is selected from the viewpoints of hue angle, saturation, lightness, weather resistance, OHP transparency, and dispersibility in the toner. The colorant is used in an amount of 1 to 20 parts by mass per 100 parts by mass of the resin. When a magnetic material is used as a black colorant, unlike other colorants, 4 parts per 100 parts by mass of the resin are used.
It is used by adding 0 to 150 parts by mass.

The charge control agents used in the present invention include:
Although a known toner can be used, in the case of a color toner, a charge control agent that is colorless, has a high toner charging speed, and can stably maintain a constant charge amount is particularly preferable. Further, a charge control agent having no polymerization inhibitory property and no solubilized substance in an aqueous system is particularly preferable.

Specific compounds include metal compounds of salicylic acid, naphthoic acid, dicarboxylic acid, sulfonic acid, high molecular compounds having carboxylic acid in the side chain, boron compounds, urea compounds, silicon compounds, curryx Arenes and the like can be used, and a quaternary ammonium salt, a high molecular compound having the quaternary ammonium salt in a side chain, a guanidine compound, an imidazole compound and the like are preferably used as the positive system.

The charge control agent is preferably used in an amount of 0.5 to 10 parts by mass per 100 parts by mass of the resin. However, in the present invention, the addition of a charge control agent is not essential, and in the case where a two-component developing method is used, even if a non-magnetic one-component blade coating developing method is used, utilizing frictional charging with a carrier. By positively utilizing frictional charging with the blade member and the sleeve member, it is not necessary to necessarily include a charge control agent in the toner.

Examples of the polymerization initiator used in the present invention include 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile,
1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-
Azo-based polymerization initiators such as dimethylvaleronitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-
A peroxide-based polymerization initiator such as dichlorobenzoyl peroxide, lauroyl peroxide, and t-butylperoxy-2-ethylhexanoate is used.

The amount of the polymerization initiator varies depending on the desired degree of polymerization.
２０20% by mass is used. The type of initiator is
Depending on the polymerization method, it may be used alone or in combination with reference to the 10-hour half-life temperature. Further, in order to control the degree of polymerization, a known crosslinking agent, chain transfer agent, polymerization inhibitor and the like can be further added and used.

When suspension polymerization is used as the toner production method of the present invention, as a dispersant to be used, for example, inorganic oxides such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, Examples thereof include calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina, magnetic material, and ferrite.
As the organic compound, for example, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch and the like are used by being dispersed or dissolved in an aqueous phase. It is preferable to use 0.2 to 10.0 parts by mass of these dispersants based on 100 parts by mass of the polymerizable monomer.

As these dispersants, commercially available ones may be used as they are, but in order to obtain fine and uniform dispersed particles, the inorganic compound may be formed under high-speed stirring in a dispersion medium. it can. For example, in the case of tricalcium phosphate, a dispersant suitable for a suspension polymerization method can be obtained by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring. Further, 0.001 to 0.1 parts by mass of a surfactant may be used in combination for making these dispersants finer.

Specifically, commercially available nonionic, anionic and cationic surfactants can be used.
Sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate,
Potassium stearate, calcium oleate and the like are preferably used.

A specific method for producing a toner according to the present invention is as follows: a releasing agent, a coloring agent, a charge control agent, a polymerization initiator and other additives comprising a low-softening substance are added to a monomer; The monomer composition uniformly dissolved or dispersed by a disperser or the like is dispersed in a granulation container containing a dispersion stabilizer containing a stirrer as shown in FIGS.

Granulation is stopped when the droplets of the monomer composition have the desired toner particle size. Thereafter, by the action of the dispersion stabilizer, stirring may be performed to such an extent that the particle state is maintained and the particles are prevented from settling. The polymerization is performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C.

The temperature may be raised in the latter half of the polymerization reaction. Further, in order to remove unreacted polymerizable monomers and by-products, the aqueous medium is partially distilled off in the latter half of the reaction or after completion of the reaction. May be. After completion of the reaction, the generated toner particles are collected by washing and filtration, and dried. In the suspension polymerization method, it is usually preferable to use 300 to 3,000 parts by mass of water as a dispersion medium with respect to 100 parts by mass of the monomer system.

The external additive used for the purpose of imparting various toner characteristics preferably has a particle size of 1/10 or less of the weight average particle size of the toner particles from the viewpoint of durability when added to the toner. . The particle size of the additive means an average particle size obtained by observing the surface of the toner particles with an electron microscope. As the external additive, for example, the following are used.

Metal oxides (aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, tin oxide, zinc oxide, etc.), nitrides (silicon nitride, etc.), carbides (silicon carbide, etc.), metals Salts (calcium sulfate, barium sulfate, calcium carbonate, etc.), fatty acid metal salts (zinc stearate, calcium stearate, etc.), carbon black, silica, etc. These external additives are used in an amount of 0.01 to 100 parts by mass of the toner particles.
10 parts by mass are used, preferably 0.05 to 5 parts by mass. These external additives may be used alone or in combination of two or more. Each of which has been subjected to a hydrophobic treatment is more preferable.

The average particle size and the particle size distribution of the toner can be measured by various methods such as Coulter Counter TA-II or Coulter Multisizer (manufactured by Coulter Co., Ltd.).
Interface (made by Nikkaki) for outputting number distribution and volume distribution using type II (manufactured by Coulter) and PC9
801 personal computer (manufactured by NEC) is connected, and the electrolyte solution is 1% NaC using primary grade sodium chloride.
Prepare an aqueous solution. For example, ISOTON R-II
(Manufactured by Coulter Scientific Japan) can be used.

The measuring method is as follows.
0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersing agent to 150 ml, and 2 to 20 mg of a measurement sample is further added. The electrolyte solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes using an ultrasonic disperser, and a 100 μm aperture was used as the aperture by the Coulter Counter TA-II.
The volume distribution and the number distribution were calculated by measuring the volume and the number of the toner particles having a size of μm or more. Then, the volume-based weight average particle diameter (D ₄ : the median value of each channel is a representative value of the channel) obtained from the volume distribution according to the present invention, the weight variation coefficient (S ₄ ), and the number obtained from the number distribution The standard length average particle size (D ₁ ) and number variation coefficient (S ₁ ) were determined.

The image density is a value obtained by measuring (5 mm square, 5 mm circle, solid black) with a Macbeth densitometer (manufactured by Macbeth).

[0065]

The present invention will be described in more detail with reference to specific examples and comparative examples.

<Example 1> 450 parts of a 0.1 mol / liter-Na ₃ PO ₄ aqueous solution was added to 710 parts by mass of ion-exchanged water.
After charging the mass part and heating to 60 ° C., the maximum peripheral speed of the stirring blade is 28.3 m / sec using the apparatus shown in FIGS.
The mixture was stirred at c. The specifications of the device shown in FIGS. 1 and 3 are: D2 / D1 = 0.32, H / D1 = 0.56, D1 / D
= 0.25.

To this was added 1.0 mol / l-CaCl
₍₂₎ 68 parts by mass of an aqueous solution is added, and a minute poorly water-soluble dispersant C is added.
An aqueous dispersion medium containing a ₃ (PO ₄ ) ₂ was obtained.・ (Monomer) styrene 170 parts by mass ・ (monomer) n-butyl acrylate 30 parts by mass ・ (colorant) C.I. I. Pigment Red 122 10 parts by mass ・ (Charge control agent) salicylic acid metal compound 3 parts by mass ・ (Polar resin) saturated polyester 20 parts by mass [Acid value 10 mgKOH / g, peak molecular weight: 7,500] ・ (Release agent) ester wax [Melting point: 70 ° C] 25 parts by mass The above formulation was heated to 60 ° C, and was uniformly dissolved or dispersed using a dissolution tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved therein as a polymerization initiator to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into the aqueous dispersion medium, and the polymerizable monomer composition was granulated at 60 ° C. in an N ₂ atmosphere. The stirring blade has a maximum peripheral speed of 28.
Stirring was continued at 3 m / sec.

The flow direction of the fluid at this time was confirmed with a high-speed video camera (Kodak Ecta Promotion Analyzer HS4540). As shown in FIG. 1, the fluid was sucked from above and below the stirring chamber and ejected from the side. It was confirmed that it was.

Immediately after the polymerizable monomer composition was charged into the granulation container, the inside of the granulation container was confirmed with the above high-speed video camera, and the polymerizable monomer composition was smoothly mixed into the aqueous medium. I was able to confirm that it was going.

Ten minutes after the addition of the polymerizable monomer composition, the stirring device was stopped, and the mixture was transferred to a polymerization tank equipped with paddle stirring blades. In the polymerization tank, the reaction was performed for 10 hours while stirring with a paddle stirring blade at 60 ° C. in an N ₂ atmosphere. After the polymerization reaction,
The remaining monomer was distilled off under reduced pressure, and after cooling, hydrochloric acid was added to dissolve the calcium phosphate, followed by filtration, washing and drying to obtain colored suspended particles.

When the particle size distribution of the colored suspension particles was measured with a Coulter Multisizer, the weight average particle size was 6.5 μm.
m and the number variation coefficient was 25%.

Here, the number variation coefficient is represented by the number variation coefficient = [S / D ₁ ] × 100, where S represents a standard deviation in the number distribution of toner particles, and D ₁ represents the average number of toner particles. Diameter (μ
m). That is, the smaller the value of the variation coefficient, the sharper the particle size distribution of the toner particles, and the larger the value, the broader the particle size distribution.

When the tomographic plane of the toner was observed, a core / shell structure was confirmed.

With respect to 100 parts by mass of the obtained particles, BE
1.5 parts by mass of hydrophobic silica having a specific surface area of 200 m ² / g by the T method was externally added to obtain a suspension-polymerized toner 1. 95 parts by mass of an acrylic-coated ferrite carrier was mixed with 5 parts by mass of this toner to prepare a developer. Using this developer, Canon full color copier CLC5
Evaluation of 5,000 continuous prints on a remodeling machine No. 00 showed no fog, stable image density, and good images.

<Example 2> 450 parts of a 0.1 mol / liter-Na ₃ PO ₄ aqueous solution was added to 710 parts by mass of ion-exchanged water.
After charging the mass part and heating to 60 ° C., the maximum peripheral speed of the stirring blade is 28.3 m / sec using the apparatus shown in FIGS.
The mixture was stirred at c. The specifications of the device shown in FIGS. 1 and 3 are: D2 / D1 = 0.57, H / D1 = 0.43, D1 / D
= 0.25.

Thereafter, colored suspension particles were obtained in the same manner as in Example 1.

When the particle size distribution of the obtained colored suspended particles was measured with a Coulter Multisizer, the weight average particle size was 6.
At 3 μm, the number variation coefficient was 24%.

When the tomographic plane of the toner was observed, a core / shell structure was confirmed.

The obtained particles were evaluated for image formation in the same manner as in Example 1. As a result, there was no fog, the image density was stable, and a good image was obtained.

<Example 3> 450 parts of a 0.1 mol / liter-Na ₃ PO ₄ aqueous solution was added to 710 parts by mass of ion-exchanged water.
After charging the mass part and heating to 60 ° C., the maximum peripheral speed of the stirring blade is 28.3 m / sec using the apparatus shown in FIGS.
The mixture was stirred at c. The specifications of the device shown in FIGS. 1 and 3 are: D2 / D1 = 0.8, H / D1 = 0.27, D1 / D =
0.25.

Thereafter, colored suspended particles were obtained in the same manner as in Example 1.

When the particle size distribution of the obtained colored suspended particles was measured with a Coulter Multisizer, the weight average particle size was 6.
At 8 μm, the number variation coefficient was 30%.

When the tomographic plane of the toner was observed, a core / shell structure was confirmed.

When the obtained particles were evaluated for image formation in the same manner as in Example 1, no fog was found, the image density was stable, and a good image was obtained.

<Example 4> 450 parts of a 0.1 mol / liter-Na ₃ PO ₄ aqueous solution was added to 710 parts by mass of ion-exchanged water.
After charging the mass part and heating to 60 ° C., the maximum peripheral speed of the stirring blade is 28.3 m / sec using the apparatus shown in FIGS.
The mixture was stirred at c. The specifications of the device shown in FIGS. 1 and 3 are: D2 / D1 = 0.57, H / D1 = 0.43, D1 / D
= 0.16.

Thereafter, colored suspension particles were obtained in the same manner as in Example 1.

When the particle size distribution of the obtained colored suspended particles was measured with a Coulter Multisizer, the weight average diameter was 6.
At 3 μm, the number variation coefficient was 23%.

When the tomographic plane of the toner was observed, a core / shell structure was confirmed.

The image formation evaluation of the obtained particles was performed in the same manner as in Example 1. As a result, no fog was found, the image density was stable, and a good image was obtained.

<Example 5> 450 parts of a 0.1 mol / liter-Na ₃ PO ₄ aqueous solution was added to 710 parts by mass of ion-exchanged water.
After the mass part was charged and heated to 60 ° C., the mixture was stirred at the maximum peripheral speed of the stirring blade of 37 m / sec using the apparatus shown in FIGS. The specifications of the device shown in FIGS. 1 and 3 are: D2 / D1 = 0.57, H / D1 = 0.43, D1 / D
= 0.16.

Thereafter, the same formulation as in Example 1 was heated to 60 ° C. and uniformly dissolved or dispersed using a dissolving tank (with a stirrer). 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved therein as a polymerization initiator to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into the aqueous dispersion medium, and the polymerizable monomer composition was granulated at 60 ° C. in an N ₂ atmosphere. The stirring blade has a maximum peripheral speed of 37m
The stirring was continued at / sec to obtain colored suspended particles in the same manner as in Example 1.

When the particle size distribution of the obtained colored suspended particles was measured with a Coulter Multisizer, the weight average diameter was 6.
At 3 μm, the number variation coefficient was 22%.

When the tomographic plane of the toner was observed, a core / shell structure was confirmed.

When the obtained particles were evaluated for image formation in the same manner as in Example 1, no fog was found, the image density was stable, and a good image was obtained.

<Comparative Example 1> 450 parts of a 0.1 mol / liter-Na ₃ PO ₄ aqueous solution was added to 710 parts by mass of ion-exchanged water.
After charging the mass part and heating to 60 ° C., the maximum peripheral speed of the stirring blade is 28.3 m / sec using the apparatus shown in FIGS.
The mixture was stirred at c. The specifications of the device shown in FIGS. 1 and 3 are: D2 / D1 = 0.28, H / D1 = 0.67, D1 / D
= 0.25.

The flow direction of the fluid at this time was visually confirmed with a high-speed video camera (manufactured by Kodak Company, Ecta Promotion Analyzer HS4540), and no suction was seen from the lower part of the stirring chamber, and the jet flow from the screen was not observed. Has also been confirmed to have decreased.

Thereafter, colored suspended particles were obtained in the same manner as in Example 1.

When the particle size distribution of the obtained colored suspended particles was measured with a Coulter Multisizer, the weight average particle diameter was 7.
At 0 μm, the number variation coefficient was 35%, and the particle size distribution was broad.

The image formation evaluation of the obtained particles was carried out in the same manner as in Example 1. As a result, fog was generated after 1,000 sheets of durability, and the image quality was rough.

[0102]

[Table 1]

[0103]

As described above, according to the production method of the present invention, the particle size distribution at the time of granulation of the polymerizable monomer composition can be sharpened, and finally a classification step is required. In addition, even if classified, a toner having a high particle size distribution and a high yield can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of a granulating apparatus used in a production method of the present invention.

FIG. 2 is a sectional view of the stirring device in FIG.

FIG. 3 is a sectional view of a stirring blade.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Granulation container 2 Stirrer 3 Stirring shaft 4 Stirring blade 5 Screen 6 Stirring chamber 7 Jacket 8 Liquid level

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yoshihiro Nakagawa 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H005 AA11 AA12 AB06 AB07 CA14 EA03 EA10

Claims (10)

[Claims] 1. A method for producing a toner comprising at least a toner particle granulation step and a polymerization step, wherein the toner particle granulation step contains a polymerizable monomer composition and a dispersion stabilizer in a granulation container. And granulating by dispersing in a liquid dispersion medium that is substantially incompatible with the polymerizable monomer composition, wherein agitation having a high shear force is provided in the granulation container. The stirring device is provided with a stirring blade that rotates at high speed and a stirring chamber, and the major axis of the rotating body formed when the stirring blade rotates is D1, the minor axis is D2, and the height is H. 0.9> D2 / D1> 0.3 and 0.1 <H / D1
<0.6. A method for producing a toner, having the following relationship: 0.6. 2. When the major axis of the rotating body is D1, the minor axis is D2, and the height is H, 0.7> D2 / D1> 0.4 and 0.2 <H / D1.
2. The method according to claim 1, wherein the toner has a relationship of <0.5. 3. The method for producing a toner according to claim 1, wherein the liquid fluid to the stirring chamber is sucked from above and below the stirring chamber and ejected from a side surface. 4. The method according to claim 1, wherein a length D1 of the stirring blade and an inner diameter D of the granulation vessel have a relationship of 0.05 <D1 / D <0.35. Production method of toner. 5. The method according to claim 1, wherein the long diameter D1 of the stirring blade and the inside diameter D of the granulation container have a relation of 0.1 <D1 / D <0.3. Production method of toner. 6. The method according to claim 1, wherein the granulating step is a batch process. 7. The maximum peripheral speed of the high-speed rotating stirring blade is 1
The method for producing a toner according to claim 1, wherein the pressure is 5 to 45 m / sec. 8. The maximum peripheral speed of the high-speed rotating stirring blade is 1
The method for producing a toner according to any one of claims 1 to 6, wherein the pressure is 7 to 40 m / sec. 9. The method for producing a toner according to claim 1, wherein the toner has a core / shell structure. 10. The main component of the core part has a melting point of 40-9.
The method for producing a toner according to claim 9, wherein the toner is a substance having a low softening point of 0 ° C. 11.