JP2003122051A - Method of manufacturing electrostatic charge image developing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel manufacturing method which is capable of easily and rapidly manufacturing a spherical or approximately spherical chemical toner and manufactures the chemical toner containing a polyester resin having a sharp grain size distribution as a binder resin without loss of emulsification in a high yield. SOLUTION: In the method of manufacturing the electrostatic charge image developing toner, the toner is manufactured by performing a emulsifying process of emulsifying a mixture containing at least a polyester resin and an organic solvent into an aqueous medium, thereby forming the particulates of the above mixture in this aqueous medium and a compounding process of compounding the particulates by adding a dispersion stabilizer to the particulates, then further successively adding electrolytes thereto.

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 for developing an electrostatic charge image, which is preferably used in electrophotographic copying machines, printers, fax machines and the like, and is also used in toner jet printers and the like. .

[0002]

2. Description of the Related Art In recent years, in electrophotographic copying machines, printers, fax machines, etc., toner has been used in order to further improve print image quality, machine cost reduction, size reduction, power saving and resource saving. The following needs are increasing. (1) Improvement of resolution and gradation of printed image by reducing toner particle size, thinning of toner layer, reduction of waste toner amount, reduction of toner consumption per page (2) Fixing temperature Reduction of power consumption by lowering temperature (3) Simplification of machine by oilless fixing (4) Improvement of hue, transparency and gloss in full color image (5) Harmful VOC (volatile organic compound) at the time of fixing toner ) Is reduced.

Even with powder toners obtained by the pulverization method that has been used for a long time, it is basically possible to reduce the particle size.
As the particle size becomes smaller, the ratio of the release agent such as a colorant or wax exposed on the surface of the toner particles increases, which makes it difficult to control the charge. The toner particles have an irregular shape, which deteriorates the powder fluidity. However, problems such as a rise in energy cost required for production occur, and it is practically difficult for the toner by the pulverization method to sufficiently satisfy the above needs.

From such a background, a toner (hereinafter referred to as a chemical toner) conventionally produced by a polymerization method or an emulsion dispersion method is used.
Has been actively developed. Various methods are known for the toner by the polymerization method. Among them, a monomer, a polymerization initiator, a colorant, a charge control agent, etc. are added to an aqueous medium with stirring in the presence of a dispersion stabilizer to obtain an oil. A suspension polymerization method is widely known in which droplets are formed and then heated to carry out a polymerization reaction to obtain toner particles. Alternatively, an association method has also been proposed in which fine particles are formed by emulsion polymerization or suspension polymerization, the fine particles are aggregated, and the aggregated fine particles are fused to obtain toner particles. However, in such a polymerization method or an association method using fine particles produced by the polymerization method, although there is no problem in reducing the particle diameter of the toner particles, the main component of the binder resin is limited to the radical-polymerizable vinyl polymer. Therefore, it is not possible to manufacture a toner using a polyester resin or an epoxy resin suitable for a color toner or the like. In the polymerization method,
There is also a problem that it is difficult to reduce VOC (volatile organic compound consisting of unreacted monomer etc.), and its improvement is desired.

On the other hand, the toner production method by the emulsion dispersion method is as follows.
JP-A-5-66600 and JP-A-8-212655
As disclosed in, for example, Japanese Patent Publication No. JP-A No. 2003-242, a method of obtaining a toner particle by mixing a mixture of a binder resin and a colorant with an aqueous medium and emulsifying the mixture. In addition to being able to easily cope with diameter and spheroidization, compared to the polymerization method, the range of selection of binder resin types is wide, it is easy to reduce residual monomers, and the concentration of colorants etc. can be changed from low to high. It has the advantage that it can be changed arbitrarily.

By the way, as the binder resin for the toner, which has a relatively low fixing temperature and is apt to be melted sharply at the time of fixing to make the image surface smooth, a polyester resin is preferable to a styrene-acrylic resin, and particularly for a color toner. Is preferably a polyester resin having excellent flexibility. However, as described above, the polymerization method cannot produce toner particles containing a polyester resin as a main component of the binder resin. Therefore, in recent years, attention has been paid to the production of a small particle diameter toner using a polyester resin as a binder resin by an emulsion dispersion method.

However, in each of the publications that produce toner by the above-mentioned emulsion dispersion method, the lowering of the fixing temperature of the toner and the widening of the offset temperature resistance region are not necessarily sufficiently realized, and In the method of producing a toner by the emulsion dispersion method, it is difficult to recover and reuse the solvent because a mixed solvent is used. In addition, the generation of fine particles is inevitable, and an emulsion loss (water-soluble resin) is also generated. However, there is a problem in that productivity is poor.

As a manufacturing method for solving such a problem, for example, in JP-A-10-020552, JP-A-11-007156 and the like (hereinafter referred to as A patent group), a polyester resin is used as a binder resin. It has been proposed a method for producing toner particles by emulsifying and dispersing after use, aggregating the obtained fine particles, and further heating and fusing to form an aggregate. According to such a production method, it is considered that it is possible to produce a classification-free toner having no generation of ultrafine particles and thus no emulsification loss and having a sharp particle size distribution. Since it needs to be stirred for a long time, there is a problem in productivity. In order to obtain irregularly shaped particles such as in the pulverization method, if spherical or substantially spherical particles are to be obtained, a long time treatment at high temperature is required, and there is also a problem in productivity.

Further, Japanese Patent Laid-Open No. 10-147649,
In JP-A-10-319639 (hereinafter referred to as B patent group), a binder resin is emulsified and dispersed, and then agglomerates of fine particles are formed by a manufacturing method different from that of the A patent group to manufacture toner particles. Proposing a method. That is, in the production method described in the A patent group, after the binder resin and the like are emulsified and dispersed in an aqueous medium, a step of aggregating the obtained particles is performed, and then the agglomerated particles are heated and fused. In contrast to the method of producing toner particles in a two-step production process, such as the step of carrying out, the method of producing the toner proposed in the above-mentioned B patent group is such that the fine particles are produced by emulsion dispersion and then the fine particles are produced. In this method, the toner particles are produced by simultaneously performing the step of aggregating and the step of fusing the aggregated fine particles together. Hereinafter, in the present invention, a method for producing a toner in which aggregation and fusion of fine particles produced by such emulsification and dispersion are performed in one step is referred to as a “coalescence” production method, and two methods of aggregation and fusion are described. A method of manufacturing a toner in which steps are sequentially performed is referred to as a method of manufacturing by "association" to distinguish the two. According to the manufacturing method by coalescence, spherical toner particles can be easily obtained in a short time. However, in the production method according to the B patent group, since the dispersion stabilizer and the electrolyte are not used and the coalescence is performed by the collision between the particles under a high shearing force, the coalescence tends to be non-uniform, and the aggregate Occurrence is unavoidable. Since emulsification and dispersion are performed under high shearing force, and particles are subsequently aggregated under the same conditions, crushing occurs competitively with coalescence, which increases the generation of fine particles and narrows the distribution of generated toner particles. There was a limit to that.

Further, in the polyester resins specifically shown in the A patent group and the B patent group, the fixing performance at a low temperature is improved, but the offset resistance at a high temperature is inferior. The desired oilless type heat roll fixing was insufficient.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. An object of the present invention is to bind a polyester resin having no emulsion loss, a high yield, and a sharp particle size distribution. It is an object of the present invention to provide a new manufacturing method for manufacturing a chemical toner as a resin. Another object of the present invention is to provide a new manufacturing method for manufacturing a spherical or substantially spherical chemical toner simply and in a short time. Another object of the present invention is to produce a new chemical toner suitable for a so-called oilless fixing method, which has a good fixing / offset temperature range without using an offset prevention liquid, as a toner used in a heat roll fixing method. To provide a method.

[0012]

DISCLOSURE OF THE INVENTION The inventors of the present invention have focused their attention on a method for producing a chemical toner by unity, and as a result of intensive studies, as a result, have found a method for producing a toner for developing an electrostatic charge image that can solve the above problems. Heading, completed the present invention. That is, the present invention, by emulsifying a mixture containing at least a polyester resin and an organic solvent in an aqueous medium, an emulsification step of forming fine particles of the mixture in the aqueous medium, and then adding a dispersion stabilizer. Further, the present invention provides a method for producing a toner for electrostatic charge image development, in which a toner is produced by performing a coalescence step of coalescing the fine particles by sequentially adding an electrolyte.

In the production method of the present invention, coalescence can be stably carried out by adding a dispersion stabilizer to a dispersion obtained by emulsifying a mixture containing a polyester resin and the like, and then adding an electrolyte. . Further, a chemical toner having a binder resin of polyester resin, which has no emulsion loss and has a sharp particle size distribution, can be easily obtained in a short time and at a high yield. Especially, the tip is 0.2 ~
The above effect becomes remarkable by stirring under a low shearing force using a manufacturing apparatus having a stirring blade that rotates at a peripheral speed of 10 m / s or 0.2 to 10 m / s.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
The manufacturing method of the present invention comprises the following steps. A first step: a step of emulsifying a resin solution containing at least a polyester resin and an organic solvent in an aqueous medium to form fine particles; a second step: a step of coalescing the fine particles to produce an aggregate of the fine particles; Step: a step of removing the organic solvent contained in the agglomerates, then separating and washing the agglomerates of the fine particles from an aqueous medium, and drying to produce a toner (the toner in the present invention is a third step (Refers to the dried aggregate of the agglomerate produced in 1.), and the above three steps.

In the first step, a polyester resin is put into an organic solvent, and the resin is dissolved and dispersed (when necessary, heated) to prepare a mixture containing the polyester resin and the organic solvent. In this case, as the toner raw material, one or more selected from various colorants, release agents or charge control agents, or other additives can be used together with the polyester resin. In the present invention, it is preferable to disperse the colorant together with the polyester resin in the organic solvent, and it is particularly preferable to similarly dissolve or disperse various additives such as a release agent and a charge control agent.

As a means for dissolving or dispersing the polyester resin and, if necessary, various additives such as a colorant, a release agent and a charge control agent in an organic solvent, the following method is preferably used.

A polyester resin used by using a mixture containing various additives such as the above polyester resin, a colorant, a release agent, and a charge control agent by using a pressure kneader, a heating twin roll, a twin-screw extrusion kneader, or the like. Is heated to a temperature not lower than the softening point and not higher than the thermal decomposition temperature and kneaded. At this time, the colorant and the like may be melt-kneaded as a master batch. Then, the obtained kneading chips are prepared by dissolving or dispersing them in an organic solvent with a stirrer such as Despar. Alternatively, the polyester resin is mixed with various additives such as a colorant, a release agent, a charge control agent and the like, and the mixture is wet-kneaded by a ball mill or the like. In this case, the colorant and the release agent may be separately preliminarily dispersed and then mixed.

As a more specific means, a resin solution prepared by previously dissolving a polyester resin in an organic solvent in a mixing / dispersing machine using a medium such as a ball mill, a bead mill, a sand mill or a continuous bead mill, and a colorant are used. A resin solution in which a coloring agent, a release agent, etc. are finely dispersed in an organic solvent by mixing a polyester resin for dilution and an additional organic solvent by adding a release agent There is a method of manufacturing. At this time, a low-viscosity polyester resin and a colorant, or a release kneader is preliminarily kneaded with a pressure kneader, rather than directly adding a colorant or a release agent to a mixing / dispersing machine such as a ball mill without treatment. It is preferable to use a masterbatch obtained by kneading and dispersing with a heated two-roll. According to the manufacturing method as described above, the polymer component (gel component) of the polyester resin is not cut, and thus it is preferable to the method of dispersing by melt-kneading.

Examples of the organic solvent for dissolving or dispersing the polyester resin and a coloring agent, a releasing agent and the like which are added as required include, for example, pentane, hexane, heptane, benzene, toluene, xylene, cyclohexane,
Hydrocarbons such as petroleum ether; halogenated hydrocarbons such as methylene chloride, chloroform, dichloroethane, dichloroethylene, trichloroethane, trichloroethylene, carbon tetrachloride; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone; ethyl acetate, butyl acetate Esters and the like are used. These solvents may be used as a mixture of two or more kinds, but from the viewpoint of solvent recovery, it is preferable to use the same kind of solvent alone. Further, the organic solvent is preferably one that dissolves the binder resin, has relatively low toxicity, and has a low boiling point that is easy to remove the solvent in the subsequent step, and such a solvent is most preferably methyl ethyl ketone.

Next, as a method of emulsifying the mixture containing the polyester resin and the organic solvent in the aqueous medium, the above-mentioned method comprising the polyester resin, the coloring agent and the like added as necessary, and the organic solvent was prepared. The mixture is preferably emulsified by mixing with an aqueous medium in the presence of a basic neutralizing agent. In this step, a method in which an aqueous medium (water or a liquid medium containing water as a main component) is gradually added to a mixture of a polyester resin, a colorant and the like and an organic solvent is preferable. In that case, by gradually adding water to the organic continuous phase of the mixture, a discontinuous phase of Water in Oil is generated,
By additionally adding water, the phase is inverted to the discontinuous phase of Oil in Water to form a suspension / emulsion in which the mixture is suspended as particles (droplets) in the aqueous medium (hereinafter , This method is called phase inversion emulsification).

In the phase inversion emulsification, water is added so that the ratio of water to the total amount of the organic solvent and the added water is 30 to 70%. More preferably 35 to 65%,
It is particularly preferably 40 to 60%. The aqueous medium used is preferably water, more preferably deionized water.

The polyester resin used in the present invention is preferably an acidic group-containing polyester resin, and a polyester resin which becomes self-dispersible by neutralizing the acidic group (hereinafter referred to as self-dispersible resin). ) Is preferable. The acid value of the self-water-dispersible polyester resin used in the present invention is preferably 1-20. The resin having self-water dispersibility becomes an anion type by neutralizing an acidic group with a basic neutralizing agent. as a result,
The hydrophilicity of the resin is increased, and the resin can be stably dispersed in an aqueous medium without using a dispersion stabilizer or a surfactant.
Examples of the acidic group include an acidic group such as a carboxyl group, a sulfonic acid group, and a phosphoric acid group. Among them, the carboxyl group is preferable from the viewpoint of toner charging characteristics. The basic substance for neutralization is not particularly limited, and for example, an inorganic base such as sodium hydroxide, potassium hydroxide or ammonia, or an organic base such as diethylamine, triethylamine or isopropylamine can be used. Of these, inorganic bases such as ammonia, sodium hydroxide and potassium hydroxide are preferable. In order to disperse the polyester resin in the aqueous medium, there is a method of adding a suspension stabilizer or a dispersion stabilizer such as a surfactant. However, a suspension stabilizer or a surfactant is added to emulsify the polyester resin. The method requires high shear forces. As a result, coarse particles are generated and the particle size distribution becomes broad, which is not preferable. Therefore, in the present invention, it is preferable to use a self-water-dispersible resin and neutralize the acidic group of the resin with a basic compound.

As a method for neutralizing the acidic group (carboxyl group) of the polyester resin with a base, for example, (1) after preparing a mixture containing a polyester resin having an acidic group, a colorant, a wax and an organic solvent, A method of neutralizing with a base, or (2) a method of previously mixing a basic neutralizing agent in an aqueous medium and neutralizing the acidic groups of the polyester resin contained in the mixture during phase inversion emulsification, Can be mentioned.

Examples of the phase inversion emulsification method include (A) a method of adding the mixture to an aqueous medium to emulsify it, and (B) a method of adding an aqueous medium to the mixture. In the present invention, it is preferable to adopt a method in which the above (1) and (B) are combined, because the particle size distribution becomes sharp.

In phase inversion emulsification, a homomixer (Tokuki Kika Kogyo Co., Ltd.), a slasher (Mitsui Mining Co., Ltd.), Cavitron (Eurotech Co., Ltd.),
Used with high-share emulsifying dispersers such as Microfluidizer (Mizuho Kogyo Co., Ltd.), Menton Gorin Homogenizer (Gorin Co., Ltd.), Nanomizer (Nanomizer Co., Ltd.), Static Mixer (Noritake Co.), etc. it can.

However, rather than using the above-mentioned disperser having a high market share, for example, Japanese Patent Laid-Open No. 9-114135.
It is preferable to use a stirrer, an anchor blade, a turbine blade, a Fowler blade, a full zone blade, a Maxblend blade, a half-moon blade, etc. as disclosed in (1). Above all, a large blade having excellent uniform mixing property such as a Maxblend blade or a full zone blade is more preferable. The peripheral speed of the stirring blade in the emulsification step (phase inversion emulsification step) for forming the fine particles of the mixture in the aqueous medium is preferably 0.2 to 10 m / s, and a low peripheral speed of 0.2 to less than 8 m / s. The method of adding water while stirring with a shear is more preferable. It is particularly preferably 0.2 to 6 m / s. If the peripheral speed of the stirring blade is higher than 10 m / s, the dispersion diameter during phase inversion emulsification becomes large, which is not preferable. On the other hand, when the peripheral speed is slower than 0.2 m / s, stirring becomes non-uniform, phase inversion does not occur uniformly, and coarse particles tend to be generated, which is not preferable. The temperature during phase inversion emulsification is not particularly limited, but the higher the temperature, the more coarse particles are generated, which is not preferable. On the other hand, if the temperature is too low, the viscosity of the mixture containing the polyester resin and the organic solvent is increased, and coarse particles are also generated, which is not preferable. The temperature range during phase inversion emulsification is preferably 10 to 40 ° C. More preferably, it is in the range of 20 to 30 ° C.

As described above, using the self-water-dispersible resin,
By performing phase inversion emulsification under a low market share, it is possible to suppress the generation of fine powder and coarse particles, and as a result, it becomes easy to produce an aggregate of fine particles having a uniform particle size distribution in the next coalescence step. . Furthermore, when a polyester resin having no self-water dispersibility is used, or when phase inversion emulsification is performed under a high share, the generation of coarse particles and the low molecular weight component of the resin generate fine powder, and toner particles Has a wide particle size distribution, and further, particles containing a low molecular weight component are removed by sieving performed in a subsequent step, which causes a problem that the low temperature fixing property of the toner is deteriorated. Such inconvenience does not occur by using a water-dispersible resin or performing phase inversion emulsification under a low market share.

The 50% volume average particle size of the fine particles produced in the first step is in the range of more than 1 μm and 6 μm or less, more preferably more than 1 μm and 4 μm. When the thickness is 1 μm or less, when a colorant or a release agent is used, the polyester resin is not sufficiently encapsulated, which adversely affects the charging property and the developing property, which is not preferable. Further, if the particle size is large, the particle size of the toner obtained is limited, so it is necessary to make the particle size smaller than the particle size of the target toner.
If it is larger than m, coarse particles are likely to be generated, which is not preferable. The particle size distribution of the fine particles produced in the first step has a volume particle size ratio of 10 μm or more of 2% or less, more preferably 1% or less, and a volume particle size ratio of 5 μm or more of 10% or less. It is preferably 6% or less.

In the second step, the fine particles obtained in the first step are united to form an aggregate of the fine particles,
Toner particles of desired particle size are formed. In the second step,
A desired aggregate can be obtained by appropriately controlling the amount of solvent, the temperature, the kind or addition amount of the dispersion stabilizer and the electrolyte, the stirring conditions, and the like.

The fine particles are produced by emulsion polymerization and then
A method for producing an aggregate by raising the temperature and fusing after aggregating the fine particles is well known. The production method of the present invention is different from an aggregate produced through a two-step process of aggregation and fusion as described above, and is a production method for obtaining an aggregate in a single step including a fusion step simultaneously with aggregation. (Production method by coalescence), and has a feature that spherical or substantially spherical particles can be obtained in a short time without heating.

In the above-mentioned B patent group, a method is proposed in which the binder resin is emulsified and dispersed under high shear, and then the toner particles are produced by coalescence. In this production method, the particle size of the agglomerates is controlled by a balance between coalescence due to collision between particles under high shear and the speed at which the coalesced agglomerates are dissociated / dispersed by high shear force. . Further, the method of adding the dispersion stabilizer and the electrolyte, the timing is not disclosed, therefore, it is impossible to sufficiently suppress the generation of fine particles and the generation of coarse particles in the coalescence step, and to sharpen the particle size distribution, There is also a limit in improving the yield.

In the second step of the present invention, the dispersion liquid of the fine particles obtained in the first step is diluted with water to adjust the amount of solvent. Thereafter, a dispersion stabilizer is added, and an aqueous solution of the electrolyte is added dropwise in the presence of the dispersion stabilizer to promote coalescence, thereby obtaining an aggregate having a predetermined particle size.

The fine particles formed from the self-water-dispersible resin obtained by the first step are stably dispersed in the aqueous medium by the action of the electric double layer by the carboxylate. In the second step of the present invention, the particles are destabilized by adding an electrolyte that destroys or reduces the electric double layer to the aqueous medium in which the fine particles are dispersed. Examples of the electrolyte that can be used in the present invention include acidic substances such as hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, and oxalic acid. Also, organic and inorganic water-soluble salts such as sodium sulfate, ammonium sulfate, potassium sulfate, magnesium sulfate, sodium phosphate, sodium dihydrogen phosphate, sodium chloride, potassium chloride, ammonium chloride, calcium chloride, sodium acetate, etc. It can be effectively used as an electrolyte. These electrolytes added for coalescence may be used alone or in combination of two or more kinds of substances.
Of these, monovalent cation sulfates such as sodium sulfate and ammonium sulfate are preferable for promoting uniform coalescence. In the production method of the present invention, the fine particles obtained in the first step are swollen by the solvent, and the electric double layer of the particles is in a contracted and unstable state due to the addition of the electrolyte, which results in a low shear (low shear). Coalescence easily progresses even if the particles collide with each other due to stirring.

By the way, only by adding an electrolyte or the like, the dispersion stability of the fine particles in the system becomes unstable, so that coalescence becomes non-uniform and coarse particles and agglomerates are generated. In order to prevent the agglomerates of fine particles generated by the electrolyte or the acidic substance from repeating the re-unification and forming the agglomerates having a target particle size or more, before adding the electrolyte or the like, hydroxyapatite is used. It is necessary to add an inorganic dispersion stabilizer such as the above or an ionic or nonionic surfactant as a dispersion stabilizer. The dispersion stabilizer used must have the property of maintaining the dispersion stability even in the presence of an electrolyte added later. Examples of the dispersion stabilizer having such properties include polyoxyethylene nonylphenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester. , Polyoxyethylene sorbitan fatty acid ester and the like, or various pluronic type nonionic emulsifiers, alkylsulfate ester type anionic emulsifiers, and quaternary ammonium salt type cationic dispersion stabilizers. Among these, an anionic or nonionic dispersion stabilizer is preferable because it has an effect on the dispersion stability of the system even if it is added in a small amount. The cloud point of the nonionic surfactant is preferably 40 ° C. or higher. The surfactants described above may be used alone or in combination of two or more. In the production method of the present invention, by adding the electrolyte in the presence of the dispersion stabilizer (emulsifier), it becomes possible to prevent non-uniform coalescence, as a result, a sharp particle size distribution is obtained,
Along with this, an improvement in yield is achieved.

Further, in order to promote uniform coalescence, the stirring conditions at the time of coalescence are important. For example, Japanese Patent Laid-Open No. 9-1141
No. 35, an agitator, an anchor blade, a turbine blade, a Fowler blade, a full zone blade, a Maxblend blade, a cone cape blade, a helical blade, a double helical blade, a half-moon blade, etc. are used. Above all,
Large-sized blades such as Maxblend blades and full-zone blades that are excellent in uniform mixing are preferable. In the production method of the present invention, the fine particles swollen by the solvent coalesce and aggregate by collision due to stirring. Therefore, the high shearing device consisting of a stator and a rotor such as a homomixer, or locally high shearing such as a turbine blade, will cause non-uniform coalescence with a weak stirring blade that has a weak ability to uniformly stir the whole, resulting in coarseness. It easily leads to the generation of particles. Therefore, as the stirring conditions,
The peripheral speed is preferably 0.2 to 10 m / s, and 0.
More preferably, it is less than 2 to 8 m / s. Particularly preferably 0.
It is 2-6 m / s. If the peripheral speed is faster than 10 m / s,
Uneven coalescence occurs and coarse particles are likely to occur, which is not preferable. On the other hand, if it is slower than 0.2 m / s, the stirring share becomes insufficient, so that non-uniform coalescence also occurs and coarse particles tend to be generated, which is not preferable.

In the production method of the present invention, unlike the inventions described in the above-mentioned B patent group, coalescence proceeds only by collision of fine particles with each other, and the coalesced aggregates are dissociated and dispersed again. Absent. Therefore, the generation of ultrafine particles is small and the particle size distribution is sharp, so that the yield can be improved.

In the second step of the present invention, it is preferable to further dilute the dispersion liquid of the fine particles obtained by the phase inversion emulsification in the first step with water, if necessary. Then, the dispersion stabilizer and the electrolyte are sequentially added to perform coalescence. Alternatively,
It is preferable to adopt a procedure in which the amount of the solvent in the dispersion is adjusted by adding a dispersion stabilizer and / or an aqueous solution of an electrolyte to obtain particles having a predetermined particle size. The amount of the solvent contained in the system after adding the electrolyte is preferably in the range of 5 to 25% by weight. Further, the range of 5 to 20% by weight is more preferable, and the range of 5 to 18% by weight is particularly preferable.
When the amount of the solvent is less than 5% by weight, the electrolytic mass required for coalescence is large, which is not preferable. Also, the amount of solvent is 25% by weight
If it is more than the above range, the generation of aggregates due to non-uniform coalescence increases, and the addition amount of the dispersion stabilizer increases, which is not preferable.

In the present invention, the shape of the toner particles after coalescence can be controlled by adjusting the amount of solvent. When the amount of the solvent is in the range of 13 to 25% by weight, the degree of swelling of the fine particles by the solvent is large, and thus the spherical to substantially spherical particles can be easily obtained by coalescence. On the other hand, the amount of solvent is 5
When the amount is in the range of 13% by weight, the degree of swelling of the fine particles by the solvent is small, so that irregular-shaped to substantially spherical toner particles can be easily obtained.

The amount of the dispersion stabilizer used is preferably, for example, within the range of 0.5 to 3.0% by weight based on the solid content of the fine particles. The range of 0.5 to 2.5% by weight is more preferable, and the range of 1.0 to 2.5% by weight is particularly preferable.
If the amount is less than 0.5% by weight, the desired effect of preventing the generation of coarse particles cannot be obtained. On the other hand, if the amount is more than 3.0% by weight, coalescence does not proceed sufficiently even if the amount of electrolyte is increased, and particles having a predetermined particle size cannot be obtained.
It is not preferable because the fine particles remain and the yield is reduced.

The amount of electrolyte used is preferably in the range of 0.5 to 15% by weight based on the solid content of the fine particles. It is more preferably in the range of 1 to 12% by weight, and particularly preferably in the range of 1 to 10% by weight. When the amount of the electrolyte is less than 0.5% by weight, coalescence does not proceed sufficiently, which is not preferable. Also,
When the amount of the electrolyte is more than 15% by weight, coalescence becomes non-uniform, aggregates are generated, coarse particles are generated, and the yield is reduced, which is not preferable.

Further, the temperature at the combined time is preferably in the range of 10 to 50 ° C. It is more preferably in the range of 20 to 40 ° C, and particularly preferably 20 to 35 ° C. If the temperature is lower than 10 ° C., it becomes difficult for the coalescence to proceed, which is not preferable. Further, if the temperature is higher than 50 ° C., the rate of coalescence is increased, and aggregates and coarse particles are easily generated, which is not preferable. In the manufacturing method of the present invention, for example, 20 to 20
It is possible to form an aggregate by coalescence under conditions of low temperature such as 40 ° C. Therefore, unlike the association method, it is not necessary to raise the temperature to 80 to 90 ° C. in order to fuse the particles after they are aggregated.

In the first step and the second step of the present invention, various embodiments can be adopted within the range not impairing the gist of the present invention. Among them, preferred embodiments include the following (1) to (4). (1) polyester resin and colorant, if necessary, release agent,
Method of producing fine particles by the above-mentioned first step using a resin solution containing a charge control agent and performing the second step (coalescence step) (2) polyester resin and colorant, and if necessary release agent A method for producing fine particles by the above-mentioned first step using a resin solution consisting of, mixing the dispersion liquid of the charge control agent, and performing the second step (coalescing step) (3) Of the colorant dispersion, and optionally one or more of each of the release agent and charge control agent dispersions prepared separately, and after mixing them, the second step (Union process)
Method (4) using a resin solution consisting of a polyester resin and a release agent, fine particles are produced by the above-mentioned first step, and a dispersion liquid of a colorant and, if necessary, a dispersion liquid of a charge control agent are mixed. To perform the second step (unification step)

Various dispersion liquids such as the colorant dispersion liquid, the charge control agent dispersion liquid and the release agent dispersion liquid used here can be obtained as follows. For example, each substance is a nonionic surfactant represented by polyoxyethylene alkylphenyl ether or the like, an anionic surfactant represented by alkylbenzene sulfonate, alkyl sulfate ester salt or the like, or a quaternary ammonium salt. It can be prepared by a mechanical pulverization method using a medium by adding a cationic surfactant typified by 1) to water. Alternatively, a self-water-dispersible polyester resin may be used in place of the surfactant to prepare a dispersion liquid by the same dispersion means in the presence of a basic neutralizing agent. The colorant, release agent, and charge control agent used here may be melt-kneaded with the polyester resin in advance. In this case, the adsorption of the resin reduces the degree to which various materials are exposed on the surface of the particles, and provides preferable characteristics in charging characteristics and developing characteristics.

In order to maintain good triboelectrification performance, it is effective to prevent the colorant or the like from being exposed on the surface of the toner particles, that is, to have a toner structure in which the colorant or the like is included in the toner particles. Is. The deterioration of the chargeability due to the reduction in the particle size of the toner is also caused by the fact that a part of the contained colorant and other additives (usually wax) is exposed on the surface of the toner particles. That is, even if the content (% by weight) of the colorant and the like is the same, the surface area of the toner particles increases due to the reduction in particle size, and the ratio of the colorant and wax exposed on the surface of the toner particles increases. As a result, the composition of the surface of the toner particles changes greatly, the frictional charging performance of the toner particles changes greatly, and it becomes difficult to obtain proper charging properties.

The toner particles produced according to the present invention preferably contain a colorant, wax, etc. in the binder resin. With such an encapsulated structure, a good printed image can be obtained. . The method (1) or (2) described above is preferable in order to positively include the colorant and the release agent. The fact that the colorant, wax, etc. are not exposed on the surface of the toner particles can be easily determined by, for example, observing the cross section of the particles with a TEM (transmission electron microscope). More specifically, when a cross section obtained by embedding toner particles in a resin and cut with a microtome is dyed with ruthenium oxide or the like if necessary and observed with a TEM, a coloring agent, wax, etc. are encapsulated in the particles and are substantially uniform. It can be confirmed that they are dispersed in. Further, the method (2) is preferable in order to localize the charge control agent on the surface of the toner particles and to exert the function thereof.

The shape of the aggregate of fine particles obtained in the second step can be changed from an amorphous shape to a spherical shape depending on the degree of coalescence. For example, the average circularity is 0.9
It is possible to change from 4 to 0.99. In addition,
This average circularity can also be obtained by taking a SEM (scanning electron microscope) photograph of toner particles obtained by drying agglomerates of fine particles, and measuring and calculating the photograph. Flow particle image analyzer F
In the present invention, the value measured by this device is used as the average circularity because it can be easily obtained by using PIP-1000.

The toner particles have an average circularity of 0.9.
It is possible to improve the powder fluidity and the transfer efficiency by setting the number of the particles to a substantially spherical shape or a spherical shape of 7 or more, and it is preferable to use the above range when used as a toner.

The dispersion liquid of the agglomerates of fine particles obtained in the second step is subsequently subjected to solvent removal to remove the organic solvent from the slurry (third step). Then, dust such as resin pieces and coarse particles are removed by passing through a wet vibrating sieve, and solid-liquid separation can be performed by a known conventional means such as a centrifuge, a filter press or a belt filter. Then, the toner particles can be obtained by drying the particles. Toner particles produced using an emulsifier or dispersion stabilizer are preferably washed more thoroughly.

As a drying method, any known and commonly used method can be adopted. For example, a method of drying under normal pressure or reduced pressure at a temperature at which toner particles are not thermally fused or aggregated, a method of freeze-drying, And so on. Further, a method of simultaneously separating and drying the toner particles from the aqueous medium using a spray dryer or the like can be mentioned. In particular, a method of stirring and drying the powder under reduced pressure while heating the toner particles at a temperature at which they are not heat-fused or agglomerated, or a flash jet dryer (Seishin Enterprise Co., Ltd.) that instantaneously dries using a heated drying air stream. Method) is more efficient and preferable.

The particle size distribution of the toner obtained by the manufacturing method of the present invention is measured by Multisizer TAII type manufactured by Coulter Co., and 50% volume particle size / 50% number particle size is 1.
It is preferably 25 or less, more preferably 1.20.
It is the following. When it is 1.25 or less, a good image is easily obtained, which is preferable. The GSD is preferably 1.30 or less, more preferably 1.25 or less. In addition, GSD is measured by Coulter Multisizer TAII type,
It is a value obtained by the square root of (16% volume particle diameter / 84% volume particle diameter). The smaller the GSD value, the sharper the particle size distribution and a better image can be obtained.

The toner obtained by the production method of the present invention includes:
The volume average particle size is preferably in the range of 1 to 13 μm from the viewpoint of the obtained image quality and the like, and 3 to 10 is preferable.
About μm is more preferable because it is easy to obtain matching with the existing machine. For color toner,
The volume average particle diameter is preferably about 3 to 8 μm. When the volume average particle diameter is small, not only the resolution and gradation are improved, but also the thickness of the toner layer for forming a printed image is reduced, and the toner consumption per page is reduced, which is preferable.

The polyester resin used in the present invention is synthesized by dehydration condensation of polybasic acid and polyhydric alcohol.

Examples of the polybasic acid include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid and naphthalenedicarboxylic acid; maleic anhydride, fumaric acid, succinic acid, Aliphatic carboxylic acids such as alkenyl succinic anhydride and adipic acid; and alicyclic carboxylic acids such as cyclohexanedicarboxylic acid. These polybasic acids can be used alone or in combination of two or more. Among these polybasic acids, it is preferable to use aromatic carboxylic acids.

Examples of the polyhydric alcohol include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin, trimethylolpropane and pentaerythritol; cyclohexanediol. A cycloaliphatic diols such as cyclohexanedimethanol and hydrogenated bisphenol A; ethylene diol adducts of bisphenol A, and aromatic diols such as propylene oxide adduct of bisphenol A. These polyhydric alcohols can be used alone or in combination of two or more. Among these polyhydric alcohols, aromatic diols and alicyclic diols are preferable, and aromatic diols are more preferable.

In addition, a monocarboxylic acid and / or a monoalcohol is further added to a polyester resin obtained by polycondensation of a polyvalent carboxylic acid and a polyhydric alcohol,
The acid value of the polyester resin can be adjusted by esterifying the hydroxyl group and / or the carboxyl group at the polymerization end. Examples of the monocarboxylic acid used for such purpose include acetic acid, acetic anhydride, benzoic acid, trichloroacetic acid, trifluoroacetic acid, propionic anhydride and the like. Further, as the monoalcohol, for example, methanol, ethanol, propanol, octanol,
2-ethylhexanol, trifluoroethanol, trichloroethanol, hexafluoroisopropanol, phenol and the like can be mentioned.

The polyester resin can be produced by subjecting the polyhydric alcohol and the polycarboxylic acid to a condensation reaction according to a conventional method. For example, the polyhydric alcohol and the polycarboxylic acid are blended in a reaction vessel equipped with a thermometer, a stirrer, and a downflow condenser, and heated at 150 to 250 ° C. in the presence of an inert gas such as nitrogen, By-produced low molecular weight compounds are continuously removed from the reaction system, the reaction is stopped when the physical properties reach a predetermined value, and by cooling,
The desired reaction product can be obtained.

Such a polyester resin can be synthesized by adding a catalyst. Examples of the esterification catalyst used include organic metals such as dibutyltin dilaurate and dibutyltin oxide, and metal alkoxides such as tetrabutyl titanate. When the carboxylic acid component used is a lower alkyl ester, a transesterification catalyst can be used. Examples of the transesterification catalyst include metal acetates such as zinc acetate, lead acetate and magnesium acetate; metal oxides such as zinc oxide and antimony oxide; metal alkoxides such as tetrabutyl titanate. The amount of catalyst added is preferably in the range of 0.01 to 1% by weight based on the total amount of raw materials.

In such a polycondensation reaction, in order to produce a branched or crosslinked polyester resin, a polybasic acid having 3 or more carboxyl groups in one molecule or an anhydride thereof, and / or A polyhydric alcohol having 3 or more hydroxyl groups in one molecule may be used as an essential synthetic raw material.

As the toner used in the heat roll fixing method, in order to have a good fixing / offset temperature range without the use of an anti-offset liquid, the polyester resin is a constant load extruded capillary rheometer (hereinafter referred to as a flow tester). It is preferable that the following range is obtained by measurement according to the above). That is, the outflow start temperature Tfb by the flow tester is in the range of 80 ° C to 120 ° C, the T1 / 2 temperature is in the range of 120 ° C to 160 ° C, and the outflow end temperature Tend is 13.
It is in the range of 0 ° C to 210 ° C. By using the polyester resin having such a flow tester value, the toner for developing an electrostatic image of the present invention has good oilless fixing property. The glass transition temperature (Tg) is preferably 40 to 75 ° C.

Outflow start temperature Tfb by a flow tester,
In the present invention, the T1 / 2 temperature and the outflow end temperature Tend are obtained by using a Shimadzu flow tester (CFT-500). This flow tester includes a cylinder 2 having a nozzle 1 having a nozzle diameter D of 1.0 mmΦ and a nozzle length (depth) L of 1.0 mm as shown in FIG.
Was filled with resin 3 (weight 1.5 g), a load of 10 kg per unit area (cm ² ) was applied from the side opposite to the nozzle 1, and heating was performed at that rate at a temperature rising rate of 6 ° C. per minute. ,
It is obtained by measuring the stroke S of the load surface 4 (sink value of the load surface 4). That is, the relationship between the increased temperature and the stroke S is obtained as shown in FIG. 1 (b), and when the flow of the resin 3 from the nozzle 1 starts and the stroke S rapidly increases and the curve rises. Let Tfb be the temperature, and Tend be the temperature at which the resin 3 has flowed out of the nozzle 1 and the curve has rebounded. The temperature at S1 / 2, which is an intermediate value between the stroke Sfb at Tfb and the stroke Send at Tend, is defined as T1 / 2 temperature.

In the measurement by the temperature rising method using this apparatus, the test is conducted while raising the temperature at a constant rate with the lapse of the test time, so that the sample changes from the solid region to the transition region, the rubber-like elastic region to the fluid region. The process up to the point can be continuously measured. With this device, the shear rate and viscosity at each temperature in the flow region can be easily measured.

The outflow start temperature Tfb is an index of the sharp melting property and low temperature fixing property of the polyester resin,
If the temperature is too high, the low temperature fixability is deteriorated and cold offset is likely to occur. Further, if the temperature is too low, the storage stability is lowered and hot offset is likely to occur. Therefore, the outflow starting temperature Tfb of the toner for developing an electrostatic image of the present invention is more preferably 90 ° C to 115 ° C, and particularly preferably 90 ° C to 110 ° C.

Further, the melting temperature T of the toner by the 1/2 method
1/2 and the outflow end temperature Tend are indicators of hot offset resistance, and if both are too high, the solution viscosity increases and the particle size distribution during particle formation deteriorates. Further, if both are too low in temperature, offsetting tends to occur and the practicality is lowered. Therefore, 1/2
The melting temperature T1 / 2 by the method is required to be 120 ° C to 160 ° C, more preferably 130 to 160 ° C, and the outflow end temperature Tend is preferably 130 ° C to 210 ° C, and 130 ° C to 180 ° C. Is more preferable. Tf
By setting b, T1 / 2, and Tend within the above ranges, fixing can be performed in a wide temperature range.

Further, the above-mentioned polyester resin contains a crosslinked polyester resin, and the tetrahydrofuran insoluble content of the binder resin is in the range of 0.1 to 20% by weight, and more preferably 0.2 to 10% by weight. Range, more preferably in the range of 0.2 to 6% by weight. Thus, by using a binder resin as a polyester resin having a tetrahydrofuran insoluble content of 0.1 to 20% by weight, good hot offset resistance can be obtained. This can be ensured and is preferable. 0.
If it is less than 1% by weight, the hot offset resistance improving effect is insufficient, which is not preferable. If it is more than 20% by weight, the solution viscosity becomes too high, the fixing start temperature becomes high, and the balance of the fixability is lost, which is not preferable. Also,
Since the sharp melt property is impaired, the transparency, color reproducibility and gloss in a color image are deteriorated, which is not preferable.

Regarding the above tetrahydrofuran-insoluble matter of the binder resin, 1 g of the resin was precisely weighed, added to 40 ml of tetrahydrofuran and completely dissolved, and a funnel (diameter: Kiriyama filter paper (No. 3)) was placed. 2 g of radiolite (# 700 manufactured by Showa Kagaku Co., Ltd.) is evenly laid on 40 mm) and filtered, the cake is placed on an aluminum petri dish, and then dried at 140 ° C. for 1 hour, and the dry weight is measured. Then, the value obtained by dividing the residual resin amount in the dry weight by the initial resin sample amount is calculated as a percentage, and this value is taken as the insoluble matter.

It is more preferable that the binder resin contains a highly viscous crosslinked polyester resin and a low viscous branched or straight chain polyester resin. That is, in the polyester resin of the present invention, the binder resin may be composed of one type of polyester resin,
Generally, a cross-linked polyester resin having a high molecular weight and a high viscosity (cross-linked polyester resin) and a branched or linear polyester resin having a low molecular weight and a low viscosity are used as a blend to produce a resin. Above all, it is practical and preferable for obtaining a good fixing start temperature and hot offset resistance. When blended and used, the flow tester value of the blended resin should be within the above numerical range. In the present invention, the crosslinked polyester resin refers to a resin having a component insoluble in tetrahydrofuran, and the branched or linear polyester resin refers to a resin which has no gel content in the above gel content measurement and is soluble in tetrahydrofuran.

In the present invention, a plurality of polyester resins having different melt viscosities can be used as the binder resin.
For example, when a mixture of a low-viscosity branched or linear polyester resin and a high-viscosity crosslinked polyester resin is used, the branched or linear polyester resin (A) and the crosslinked or branched polyester resin under the following conditions are used. More preferably, it is a mixture with the mold polyester resin (B). At this time, the melt viscosity and blending amount of the resin (A) and the resin (B) are appropriately adjusted so that the flow tester value of the blended resin falls within the above numerical range.

That is, the T1 / 2 measured by a flow tester as the polyester resin (A) is 80 ° C. or higher, 1
It is less than 20 ° C and has a glass transition temperature Tg of 40 ° C to 70 ° C.
T1 by flow tester as branched or linear polyester resin at ℃ or as polyester resin (B)
/ 2 temperature is 120 ° C or more and 210 ° C or less, glass transition temperature Tg is 50-75 ° C, crosslinked or branched polyester resin, and the weight of these polyester resin (A) and polyester resin (B). The ratio is
(A) / (B) = 20/80 to 80/20, and the T1 / 2 temperatures are T1 / 2 (A) and T1 /, respectively.
2 (B), 20 ° C. <T1 / 2 (B) −T1
Those having a relationship of / 2 (A) <100 ° C. are preferably used.

Considering each temperature characteristic by the flow tester, the melting temperature T1 / 2 of the resin (A) by the 1/2 method is
(A) is an index for imparting sharp melt property and low temperature fixability, and T1 / 2 (A) is 80 to 115 ° C.
Is more preferable, and the range of 90 to 110 ° C. is particularly preferable.

Resin (A) defined by these performances
Has a low softening temperature, and in the fixing process using a heat roll, it melts sufficiently even when the applied heat energy decreases due to a lower temperature of the heat roll or a faster process speed, and provides cold offset resistance and low-temperature fixability. Demonstrate excellent performance.

Melting temperature T1 of resin (B) by 1/2 method
If both / 2 (B) and the outflow end temperature Tend (B) are too low, hot offset is likely to occur,
On the other hand, if it is too high, the particle size distribution at the time of particle formation is deteriorated and the productivity is lowered.
It is more preferably 210 ° C, and 130 ° C to 200 ° C.
It is particularly preferable that the temperature is ° C.

Resin (B) defined by these performances
Has a strong rubber elasticity and a high melt viscosity, so that the internal cohesive force of the melted toner layer is maintained even during heating and melting in the fixing process, hot offset does not easily occur, and the toughness of the toner after fixation is high. Exhibits excellent abrasion resistance.

By blending the resin (A) and the resin (B) in a well-balanced manner, it is possible to provide a toner which sufficiently satisfies anti-offset performance and low-temperature fixing performance in a wide temperature range.

Weight ratio of resin (A) and resin (B) (A)
If / (B) is too small, it affects the fixability,
Further, when it is too large, the offset resistance is affected, so that it is preferably 20/80 to 80/20, and more preferably 30/70 to 70/30.

Further, 1/2 of the resin (A) and the resin (B)
Melting temperature by the method is T1 / 2 (A), T1 / 2, respectively
In the case of (B), in order to achieve both low-temperature fixability and offset resistance, and to facilitate uniform mixing without causing a problem due to a difference in viscosity between resins, T1 / 2
The range of (B) -T1 / 2 (A) exceeds 20 ° C, 90 ° C
The temperature is more preferably below, particularly preferably over 20 to 80 ° C.

Glass transition temperature (Tg) in the present invention
Is a differential scanning calorimeter (D
SC-50) is a value obtained by measurement with a second run method at a temperature rising rate of 10 ° C. per minute.

When the Tg of the polyester resin (A) is less than 40 ° C. or the Tg of the polyester resin (B) is less than 50 ° C., the obtained toner is blocked in storage or in the developing machine (toner particles are aggregated). Phenomenon that becomes a lump)
Is likely to occur, which is not preferable. On the other hand, if the Tg of the polyester resin (A) exceeds 70 ° C. or the Tg of the polyester resin (B) exceeds 75 ° C., the fixing temperature of the toner becomes high, which is not preferable. As described above, by using the polyester resin (A) and the polyester resin (B) having the above relationship as the polyester resin serving as the binder resin, the obtained toner has a better fixing property, which is preferable. .

Further, as the binder resin made of polyester resin, the weight average molecular weight is 30,000 or more, preferably 37, by the molecular weight measurement by gel permeation chromatography (GPC) method of the tetrahydrofuran (THF) soluble component. 000 or more, weight average molecular weight (Mw)
/ Number average molecular weight (Mn) is 12 or more, preferably 15 or more, and the area ratio of the components having a molecular weight of 600,000 or more is 0.
3% or more, preferably 0.5% or more, the area ratio of the components having a molecular weight of 10,000 or less is 20 to 80%, preferably 30 to 7
It is preferable that the condition of 0% is satisfied in order to obtain good fixing property. When a plurality of resins are blended, the GPC measurement result of the final resin mixture should fall within the above numerical range.

In the polyester resin used in the production method of the present invention, the high molecular weight component having a molecular weight of 600,000 or more has a function of ensuring hot offset resistance. On the other hand, a low molecular weight component having a molecular weight of 10,000 or less is effective for lowering the melt viscosity of the resin, exhibiting sharp melt properties and lowering the fixing start temperature, and may contain a resin component having a molecular weight of 10,000 or less. preferable. In order to obtain good thermal properties such as low temperature fixing, hot offset resistance and transparency in the oilless fixing method, the binder resin preferably has such a broad molecular weight distribution.

Here, the molecular weight of the THF-soluble component of the binder resin was determined by filtering the THF-soluble substance with a 0.2 μm filter, then using Tosoh GPC HLC-8120 and Tosoh column “TSKgel Super HM-M”. (15 cm)
Using three THF solvents (flow rate 0.6 ml / min,
The temperature is measured at 40 ° C.), and the molecular weight is calculated by using the molecular weight calibration curve prepared from the monodisperse polystyrene standard sample.

The acid value of the polyester resin (resin 1 g
The number of mg of KOH required to neutralize the above is easy to obtain the above-mentioned molecular weight distribution, it is easy to secure the granulation property of fine particles by emulsion dispersion, and the environmental stability (temperature 1 to 2 from the fact that it is easy to maintain good stability of chargeability when humidity changes)
A range of 0 mg KOH / g is preferred. The acid value of the polyester resin is a raw material other than the addition of a monocarboxylic acid and / or a monoalcohol to the polyester resin obtained by polycondensation of a polyvalent carboxylic acid and a polyhydric alcohol as described above. It can be adjusted by controlling the terminal carboxyl group of the polyester by adjusting the compounding ratio and reaction rate of the polybasic acid and the polyhydric alcohol. Alternatively, by using trimellitic anhydride as the polybasic acid component, it is possible to form a polyester having a carboxyl group in the main chain.

In the production method of the present invention, a release agent can be used. In that case, the release agent is selected from the group of hydrocarbon waxes such as polypropylene wax, polyethylene wax and Fischer-Tropsch wax, synthetic ester waxes, natural ester waxes such as carnauba wax and rice wax. Release agent is used. Of these, natural ester waxes such as carnauba wax and rice wax, and synthetic ester waxes obtained from polyhydric alcohol and long-chain monocarboxylic acid are preferably used. As synthetic ester wax,
For example, WEP-5 (manufactured by NOF CORPORATION) is preferably used.
If the content of the release agent is less than 1% by weight, the releasability tends to be insufficient, and if it exceeds 40% by weight, the wax is likely to be exposed on the surface of the toner particles, and the charging property and the storage stability are deteriorated. Since it becomes easy, it is preferably in the range of 1 to 40% by weight.

In the manufacturing method of the present invention, a charge control agent can be used. The positively chargeable charge control agent is not particularly limited, and a known nigrosine dye for toner,
Quaternary ammonium compounds, onium compounds, triphenylmethane compounds and the like can be used. Also, an amino group,
A compound containing a basic group such as an imino group and an N-heterocycle, for example, a styrene acrylic resin containing a tertiary amino group is also effective as a positively chargeable charge control agent, and is used alone as a positively chargeable charge control agent of the present invention. Or in combination with the positively chargeable charge control agent. Depending on the application, a small amount of a negative charge control agent such as an azo dye metal complex or a salicylic acid derivative metal complex salt may be used in combination with these positively chargeable charge control agents. As the negatively chargeable charge control agent, trimethylethane dye, metal complex salt of salicylic acid, metal complex salt of benzyl acid, copper phthalocyanine, perylene, quinacridone, azo pigment, metal complex salt azo dye, heavy metal such as azochrome complex, etc. Examples thereof include acid dyes, calixarene type phenolic condensates, cyclic polysaccharides, resins containing a carboxyl group and / or a sulfonyl group, and the like.

The content of the charge control agent is preferably 0.01 to 10% by weight. It is particularly preferably 0.1 to 6% by weight.

The colorant used in the production method of the present invention is not particularly limited, and known and commonly used colorants are used, but pigments are particularly preferably used. As a black pigment,
Examples thereof include carbon black, cyanine black, aniline black, ferrite, magnetite and the like. Further, it is also possible to use a mixture of the following chromatic color pigments so as to give a black color.

Examples of yellow pigments include yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, ocher, titanium yellow, naphthol yellow S, Hansa yellow 10G, Hansa yellow 5G, Hansa yellow G, Hansa yellow GR, Hansa yellow. A, Hansa Yellow RN, Hansa Yellow R, Pigment Yellow L, Benzidine Yellow, Benzidine Yellow G, Benzidine Yellow GR,
Permanent Yellow NCG, Balkan First Yellow 5G, Balkan First Yellow R, Quinoline Yellow Rake, Anthragen Yellow 6GL, Permanent Yellow FGL, Permanent Yellow H10G,
Permanent yellow HR, anthrapyrimidine yellow, other isoindolinone yellow, chromophthal yellow, novopalm yellow H2G, condensed azo yellow, nickel azo yellow, copper azomethine yellow and the like can be mentioned.

Examples of red pigments include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, induslen brilliant orange RK, induslen brilliant orange GK, benzidine orange G, permanent red 4R, permanent red BL. , Permanent Red F
5RK, Resole Red, Pyrazolone Red, Watching Red, Lake Red C, Lake Red D, Brilliant Carmine 6B, Brilliant Carmine 3B, Rhodamine Lake B, Alizarin Lake, Permanent Carmine FBB, Verinone Orange, Isoindolinone Orange, Anse Anthron Orange. , Pyranthrone orange, quinacridone red, quinacridone magenta, quinacridone scarlet, perylene red and the like.

As the blue pigment, for example, cobalt blue, cerulean blue, alkali blue lake, peacock blue lake, fanatone blue 6G, Victoria blue lake, metal-free phthalocyanine blue, copper phthalocyanine blue, fast sky blue, indanthrene blue RS , Induslen Blue BC, Indico and the like.

The amount of these coloring agents used is 100
The range of 1 to 50 parts by weight per part by weight is preferred, and 2-1
A range of 5 parts by weight is especially preferred.

The dried toner particles can be used as a developer as they are, but external additives such as inorganic oxide fine particles and organic polymer fine particles, which are commonly known as external additives for toner, are added to the surface of the toner particles. Is preferred. Inorganic fine particles such as hydrophobic silica and titanium oxide, or organic fine particles are externally added to toner particles to improve physical properties such as fluidity and chargeability when used as a dry developer by electrostatic printing. effective. As the type of the external additive, hydrophobic silica treated with various silicone oils is preferably used. Examples thereof include hydrophobic silica treated with dimethyl silicone oil, alkyl-modified silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, fluorine-modified silicone oil, olefin-modified silicone oil and the like.
The external addition method is processed using a known and commonly used model.

By mixing the above toner particles with a carrier, an electrostatic image developer can be obtained. The electrostatic image developer comprises a toner produced by the production method of the present invention and a magnetic carrier, preferably a magnetic carrier whose surface is coated with a resin.

As the core agent (magnetic carrier) of the carrier used in the electrostatic image developer, iron powder, magnetite, ferrite and the like used in the ordinary two-component developing method can be used, but among them, the true specific gravity is low and the resistance is high. Therefore, ferrite or magnetite, which has excellent fluidity because it is excellent in environmental stability and easy to be spherical, is preferably used. The shape of the core agent may be spherical, amorphous or the like, and may be used without any particular problem. The average particle diameter is generally 10 to 200 μm, but 30 to 110 μm is preferable for printing a high resolution image.

Examples of coating resins for coating these core agents include polyethylene, polypropylene, polystyrene, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinylcarbazole, polyvinyl ether polyvinyl ketone, vinyl chloride. / Vinyl acetate copolymer, styrene / acrylic copolymer, straight silicone resin consisting of organosiloxane bond or its modified product, fluororesin, (meth) acrylic resin, polyester, polyurethane, polycarbonate, phenol resin, amino resin, melamine resin , Benzoguanamine resin, urea resin, amide resin, epoxy resin and the like can be used.

Among these, particularly silicone resin and (meth) acrylic resin are excellent in charging stability and coating strength and can be used more suitably. Further, the charging property of the developer composed of toner particles and carriers can be adjusted by adjusting the coating amount of a coating agent such as silicon, adding a charge control agent, and adding a conductive substance typified by carbon. That is, the resin-coated carrier used in the present invention is a resin-coated magnetic carrier that uses ferrite or magnetite as a core agent and is coated with one or more resins selected from silicon resin and (meth) acrylic resin. It is preferable to adjust the charging characteristics by adding a charge control agent, carbon or the like in the coating.

The method of coating the resin on the surface of the carrier core material is not particularly limited, but it may be a dipping method of immersing it in a solution of the coating resin, a spray method of spraying the coating resin solution on the surface of the carrier core material, or a carrier. And the like, and a kneader coater method of removing the solvent by mixing the carrier core material and the coating resin solution in a kneader coater.

The solvent used in the coating resin solution is not particularly limited as long as it dissolves the coating resin, but for example, toluene, xylene, acetone, methyl ethyl ketone, tetrahydrofuran, dioxane and the like can be used. The thickness of the coating layer on the carrier surface is usually 0.1.
Is about 3.0 μm.

The resin-coated carrier is preferably heat-treated if necessary. Particularly when coated with a resin containing a cross-linking component, the coating is reinforced by a thermal cross-linking reaction, resulting in a carrier with more excellent durability, which is preferable.

When the heat treatment is performed, the charge amount when mixed with the toner can be controlled depending on the temperature condition. In general, the higher the heating temperature, the higher the charge amount. Usually, the heat treatment is performed at a temperature of 100 ° C. to 300 ° C. for 10 minutes to 5 hours.

After the heat treatment, the carriers may adhere to each other, so stress may be applied to loosen the carrier particles.

The weight ratio of the hydrophobic silica treated with silicone oil and the resin-coated magnetic carrier is not particularly limited, but is usually 1 to 5 parts by weight of toner particles per 100 parts by weight of the carrier. If the amount is less than 1 part by weight, triboelectrification becomes advantageous, so the charge amount increases and the number of differently charged particles decreases, but the transfer amount decreases.
Not preferable. On the other hand, if it is more than 5% by weight, triboelectrification becomes insufficient, and a tendency such as a decrease in rising of charging and an increase in differently charged particles are observed, which is not preferable.

Further, the toner manufactured by the manufacturing method of the present invention can be used for a general non-magnetic one-component developing system printing device, a two-component developing system printing device, a magnetic one-component developing system printing device, and the like. . In addition, on a flexible printed circuit board around which an electrode having a function of adjusting the toner passing amount of powder toner frictionally charged by using a non-magnetic one-component developing device having a developer carrying roll and a layer regulating member is provided. It is also suitable for use in a so-called toner-jet type printer in which an image is formed by directly spraying the paper on the back electrode through the hole. The toner produced by the production method of the present invention forms an electrostatic charge image on a latent image carrier, and the obtained electrostatic charge image is developed using a developer carried on a developer carrier, Printing can be performed by an image forming method in which the toner image formed on the load image carrier is transferred onto a transfer material such as paper or film, and the toner image on the transfer material is thermally fixed by a heat roll.

It is preferable that the heat roll used here does not use an offset preventing liquid. Further, it is preferable that the release layer of the heat roll contains a tetrafluoroethylene perfluoroalkyl vinyl ether copolymer. If an offset prevention liquid is used, in addition to maintenance problems, silicone oil, etc. will migrate to the printing paper and OHP sheet, which will cause problems such as writing after printing and oil stickiness. ,
It is preferable not to use an offset prevention liquid. Also,
When the release layer of the heat roll contains the tetrafluoroethylene perfluoroalkyl vinyl ether copolymer, fatigue deterioration of the fixing roll is prevented, and the life of the fixing device itself can be extended. Further, since the releasability is high, the offset does not occur without using the offset prevention liquid, and the good fixing can be achieved.

[0103]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. In addition,
In the examples and comparative examples, unless otherwise indicated, parts are parts by weight and water is deionized water.

(Example of polyester resin synthesis) Trimellitic anhydride (TMA) as polyvalent carboxylic acid, terephthalic acid (TPA) and isophthalic acid (IP as divalent carboxylic acid)
A), polyoxypropylene (2.4) -2,2-bis (4-hydroxyphenyl) as an aromatic diol
Propane (BPA-PO), polyoxyethylene (2.
4) -2,2-bis (4-hydroxyphenyl) propane (BPA-EO) and ethylene glycol (EG) as an aliphatic diol were used in each molar composition ratio shown in Table 1,
Tetrabutyl titanate as a polymerization catalyst was charged into a separable fresco at 0.3% by weight with respect to the total amount of monomers, and a thermometer, a stirring rod, a condenser and a nitrogen inlet tube were attached to the upper part of the flask in an electric heating mantle heater under normal pressure nitrogen. After reacting at 220 ° C. for 15 hours under an air stream, the pressure was sequentially reduced and the reaction was continued at 10 mmHg. The reaction is ASTM
-The reaction was terminated by following the softening point according to E28-517 and stopping the vacuum when the softening point reached a predetermined temperature. Table 1 shows the composition and physical property values (characteristic values) of the synthesized resin.
Shown in.

[0105]

[Table 1] >600,000; area ratio of components having a molecular weight of 600,000 or more <10,000; area ratio of components having a molecular weight of 10,000 or less TMA; trimellitic anhydride TPA; terephthalic acid IPA; isophthalic acid BPA-PO; polyoxypropylene (2. 4) -2,
2-bis (4-hydroxyphenyl) propane BPA-EO; polyoxyethylene (2.4) -2,2
-Bis (4-hydroxyphenyl) propane EG; ethylene glycol BA: benzoic acid TMP; trimethylolpropane FT value; flow tester value

In Table 1, "T1 / 2 temperature" means the flow tester (CFT-500) manufactured by Shimadzu Corporation as described above.
Is a value measured at a nozzle diameter of 1.0 mmΦ × 1.0 mm, a load per unit area (cm ² ) of 10 kg, and a heating rate of 6 ° C. per minute. The glass transition temperature “Tg” (° C.) is a differential scanning calorimeter (D) manufactured by Shimadzu Corporation.
SC-50) and 10 ° C / min by the second run method.
It is the value measured at the rate of temperature rise.

(Preparation Example of Release Agent Dispersion) Carnauba Wax “Carnauba Wax No. 1” (Imported by Kato Yoko) 50
Parts and 50 parts of polyester resin (R1 in Table 1) were kneaded with a pressure kneader, and then the kneaded product and methyl ethyl ketone 185
Parts were placed in a ball mill, stirred for 6 hours and then taken out to adjust the solid content to 20% by weight to obtain a fine dispersion liquid (W1) of a release agent. Polyester resin R in the same way
2 was used to obtain a dispersion liquid (W2) of the release agent.

(Preparation of Coloring Agent Master Chip and Preparation Example of Coloring Agent Dispersion) Coloring agent master chips P1 to P5 were prepared by kneading carbon black and color pigments with a resin at a weight ratio of 50/50 in the composition shown in Table 2. Was produced. The carbon black and the resin were kneaded using a pressure kneader. Further, the color pigment and the resin were kneaded with a two-roll mill. The kneaded materials P2 to P4 thus obtained were charged into a ball mill together with methyl ethyl ketone so that the solid content would be 40% by weight.
After stirring for 6 hours, it was taken out and the solid content was 20% by weight.
To prepare a colorant dispersion liquid of P2 to P4.

[0109]

[Table 2] The colorants shown in Table 2 are as follows. Carbon: "ELFTEX-8" (manufactured by Cabot Corporation) Cyan pigment: Fastgen Blue TGR (manufactured by Dainippon Ink and Chemicals, Inc.) Yellow pigment: Shimla First Yellow 8GR
(Manufactured by Dainippon Ink and Chemicals, Inc.) Magenta pigment: Fastgen Super Magenta R
(Manufactured by Dainippon Ink and Chemicals, Inc.)

(Preparation of Wet Kneading Mill Base) The above releasing agent dispersion, colorant dispersion, diluting resin (additional resin) and methyl ethyl ketone were mixed with a despar to obtain a solid content of 55.
% To prepare mill bases (MB1 to MB5). Table 3 shows the composition of the produced mill base.

[0111]

[Table 3] >600,000; area ratio of components having a molecular weight of 600,000 or more <10,000; area ratio of components having a molecular weight of 10,000 or less

The characteristics of the blend resin used in Table 3 are shown in Table 4
It was shown to. The resin blending was carried out by blending resin particles having passed through 200 mesh at the above weight ratio and measuring the respective physical properties.

[0113]

[Table 4]

(Example 1) 545.5 parts of Millbase MB1 was placed in a cylindrical 2 L separable flask having a Maxblend blade as a stirring blade, and 23.8 of 1N ammonia water was used.
Parts, and sufficiently stirred at 350 rpm by a three-one motor, 133 parts of deionized water was added, and further stirred to adjust the temperature to 30 ° C. Then, 133 parts of deionized water was added dropwise under the same conditions to prepare a fine particle dispersion by phase inversion emulsification. The peripheral speed of the stirring blade at this time is 1.
It was 19 m / s. Next, 333 parts of deionized water was added to adjust the amount of solvent.

Next, Epan 4 which is a nonionic emulsifier
After diluting 4.1 parts of 50 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) in water and adjusting the temperature to 30 ° C. and the rotation speed to 250 rpm, 410 parts of an aqueous solution of 3% ammonium sulfate is added dropwise. Then, the amount of solvent in the dispersion liquid was set to 15.5% by weight.
Then, stirring was continued for 5 minutes under the same conditions to complete the coalescence operation. The peripheral speed of the stirring blade at this time was 0.85 m / s.
The obtained slurry was subjected to solid-liquid separation and washing with a centrifuge, and then dried with a vacuum dryer to obtain toner particles. The characteristics of the obtained toner particles are shown in Tables 5 and 6.

(Example 2) Toner particles were produced in the same manner as in Example 1 except that the coalescence operation for 5 minutes in Example 1 was changed to 70 minutes. The characteristics of the obtained toner particles are shown in Tables 5 and 6.

(Example 3) The stirring device after diluting the nonionic emulsifier in water and adding it was "TK Robotics".
Changed to (Homo Mixer manufactured by Tokushu Kika Kogyo) and set the rotation speed to 8
Toner particles were produced in the same manner as in Example 1 except that the speed was adjusted to 000 rpm and the coalescence operation was carried out for 20 minutes. The peripheral speed of the stirring blade at this time was 12.56 m / s. The characteristics of the obtained toner particles are shown in Tables 5 and 6.

Example 4 Toner particles were produced in the same manner as in Example 2 except that MB1 was changed to MB2. The characteristics of the obtained toner particles are shown in Tables 5 and 6.

(Example 5) Toner particles were produced in the same manner as in Example 2 except that MB1 was changed to MB3. The characteristics of the obtained toner particles are shown in Tables 5 and 6.

Example 6 Toner particles were produced in the same manner as in Example 2 except that MB1 was changed to MB4. The characteristics of the obtained toner particles are shown in Tables 5 and 6.

Example 7 Toner particles were produced in the same manner as in Example 2 except that MB1 was changed to MB5. The characteristics of the obtained toner particles are shown in Tables 5 and 6.

(Example 8) Toner particles were produced in the same manner as in Example 2 except that MB1 was changed to MB6. The characteristics of the obtained toner particles are shown in Tables 5 and 6.

(Comparative Example 1) 545.5 parts of Millbase MB1 was placed in a cylindrical 2 L separable flask having a Maxblend blade as a stirring blade, and 13.8 aqueous ammonia 23.8.
Parts, and sufficiently stirred at 350 rpm by a three-one motor, 133 parts of deionized water was added, and further stirred to adjust the temperature to 30 ° C. Then, 133 parts of deionized water was added dropwise under the same conditions to prepare a fine particle dispersion by phase inversion emulsification. The peripheral speed of the stirring blade at this time is 1.
It was 19 m / s. Next, 500 parts of deionized water was added to adjust the amount of solvent.

Next, without adding an emulsifier (dispersion stabilizer), the temperature was adjusted to 30 ° C. and the rotation speed was adjusted to 250 rpm, and 410 parts of a 3% ammonium sulfate aqueous solution was added dropwise to adjust the amount of the solvent to 15.5. When the weight% was set, the entire fine particles were aggregated during the dropping, and the particles could not be taken out.

Comparative Example 2 Toner particles were obtained in the same manner as in Example 3 except that the nonionic emulsifier used in Example 3 and the aqueous ammonium sulfate solution were not used. The characteristics of the obtained toner particles are shown in Tables 5 and 6.

(Comparative Example 3) 545.5 parts of Millbase MB1 was placed in a cylindrical 2 L separable flask having a Maxblend blade as a stirring blade, and 23.8 of 1N ammonia water was used.
Parts, and thoroughly stirred at 350 rpm by a three-one motor, 133 parts of deionized water was added, and further stirred, and the temperature was adjusted to 30 ° C. Then, 133 parts of deionized water was added dropwise under the same conditions to prepare a fine particle dispersion by phase inversion emulsification. The peripheral speed of the stirring blade at this time is 1.
It was 19 m / s. Next, after adding 200 parts of deionized water, the organic solvent was removed under reduced pressure until the solid content became 40%. At this time, the amount of solvent was 1% or less. The dispersion is then diluted to a solids content of 15
Adjusted to%.

To a similar stirrer and flask were charged 1000 parts of the above dispersion liquid, the temperature was 30 ° C., and the rotation speed was 250.
After adjusting to rpm, the nonionic emulsifier NL-2
50 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was diluted with 0.75 part of water and added, and then a 10% ammonium sulfate aqueous solution was added to 150 parts.
Added in parts.

At this point, when the aggregated fine particles were sampled and observed under a microscope, it was observed that spherical or substantially spherical fine particles contacted and aggregated on the surface. It was not observed that the fine particles were fused and integrated. Further, it was observed that when the sampled aggregated particles were washed with water, the individual fine particles were scattered and the aggregates were loosened. Therefore, it is understood that the agglomerates of the fine particles at this point are the agglomerates of the fine particles and not the agglomerates obtained by the coalescence in the production method of the present invention.

Thereafter, the temperature is raised at 10 ° C./min,
After stirring at 80 for 2 hours, 1.5 parts of NL-250 (Daiichi Kogyo Seiyaku Co., Ltd.) was diluted with water and added, and the temperature was adjusted to 9
The temperature was raised to 0 ° C. and stirring was continued for 7 hours to complete the aggregation / fusion operation. The peripheral speed of the stirring blade at this time was 0.85 m / s. The obtained slurry was subjected to solid-liquid separation and washing with a centrifuge, and then dried with a vacuum dryer to obtain toner particles. As described above, the toner particles of this comparative example are toner particles produced by performing a long-term treatment at a high temperature.
The characteristics of the obtained toner particles are shown in Tables 5 and 6.

[0130]

[Table 5]

[0131]

[Table 6]

The particle size and particle size distribution in Table 6 were measured by using a 100 micron aperture tube of Coulter Multisizer II manufactured by Coulter Beckman. Dv50 is 5
It is 0% volume average diameter, and Dv50 / Dn50 is the ratio of 50% average diameter of volume and number. GSD is the square root of the value obtained by dividing the 84% volume average diameter by the 16% volume average diameter. The circularity distribution was measured using a flow type particle image analyzer FPIP-1000 manufactured by Toa Medical Electronics Co., Ltd. In addition, the yield is 53% after removing the solvent of the obtained dispersion liquid of toner particles.
The value obtained by the following formula through a 0 mesh sieve is 90
-100% for ○, 80-90% for △, 60
% Or less was defined as x.

Yield (%) = {(solid content of mill base charged)-(solid content of residue on sieve)} × 100 /
(Amount of solids in the mill base loaded)

[0134]

[Table 7]

Using a Henschel mixer, 0.5 part of hydrophobic silica (H-2018 manufactured by Clariant Co., Ltd.) and 100 parts of titanium oxide (manufactured by Teika Co., Ltd.) were added to 100 parts of the toner particles of each Example and each Comparative Example. JMT-150AO) (0.5 parts) was externally added to obtain an electrostatic image developing toner (hereinafter referred to as powder toner). The thermal properties and image properties of the obtained powder toner were evaluated by the following evaluation methods, and the measurement results are shown in Table 7.

With respect to the fixing temperature range, the fixing temperature was determined by the following fixing property test and shown by the range between the upper limit value and the lower limit value.

(Fixability Test) An unfixed test pattern was developed by a commercially available copying machine using a non-magnetic two-component developing system using each powder toner using the toner particles produced in each of the examples and each comparative example. did. The printing paper was passed through a RICOH IMAGIO DA-250 heat roll (using an upper heat roll whose surface was coated with a tetrafluoroethylene perfluoroalkyl vinyl ether copolymer) at a speed of 90 mm / sec for fixing, Cellotape (registered trademark) is attached to the image after fixing, and ID (image density) after peeling
Was 90% or more of the original ID, and the surface temperature of the heat roll when no offset was observed was defined as the "fixing temperature". From the results shown in Table 7, it was confirmed that, in the examples of the present invention, both the fixing start temperature and the hot offset resistance temperature were good under the oilless fixing conditions in which no oil was applied.

(Image Output Test) For each powder toner, image formation was performed using a commercially available non-magnetic two-component developing system copying machine and non-magnetic one-component printer. The fogging, gradation and resolution of the obtained image were evaluated, and a good one was indicated by ◯, a slightly inferior one was indicated by Δ, and an inferior one was indicated by x.

(Evaluation Method of OHP Sharpness (Color Transparency)) An unfixed image is formed on the OHP sheet by the color toner using the toner particles of Examples 4 to 6, and the prepared fixing tester is used. The unfixed image was fixed.
Fixing was performed by passing through a heat roll (oilless type: coated with tetrafluoroethylene perfluoroalkyl vinyl ether copolymer) of RICOH IMAGIO DA-250 at a heat roll temperature of 160 ° C. and a speed of 90 mm / sec. The OHP sheet printed in black was placed on the OHP sheet prepared by the above procedure, projected on a screen with an overhead projector, and the sharpness of characters was visually evaluated. The evaluation results are shown by "O" when the characters are clearly visible, "Δ" when the characters are blurred, and "X" when the characters cannot be identified.

(Evaluation of heat-resistant storage stability) When each powder toner was subjected to a heat blocking resistance test at 50 ° C. for 3 days, no aggregation was observed in all the toners.

In each of the examples, it can be seen that spherical particles can be produced with good productivity in a short time. Further, it can be seen that the distribution of each particle is very sharp. Table 7
From the results, it can be seen that all of them exhibit good fixability under oilless conditions. In Example 3, generation of fine particles and coarse particles was observed more frequently and the distribution was slightly broader than in the other Examples. This is because the homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), which is a high-speed disperser with a combination of a stator and a rotor, was used to perform coalescence with high shear. This is due to the generation of coarse particles. In Comparative Example 1, since no emulsifier was used, the coalescence could not be controlled and the intended toner particles could not be obtained. Further, in Comparative Example 2, coalescence was performed with high shearing force without using an emulsifier and an electrolyte, but many fine particles and coarse particles were generated, and thus particles having a sharp particle size distribution were obtained as in Examples. You know you can't get it. Further, Comparative Example 3 is a method for producing particles consisting of two steps of agglomeration and a fusion process, but it takes a high temperature and a great amount of time to fuse and spheroidize, and productivity is higher than that of the Examples of the present invention. It turns out that it is much inferior in comparison.

[0142]

As described above, according to the production method of the present invention, since the electrolyte particles are added in the presence of the dispersion stabilizer to obtain the toner particles by coalescence, there is no emulsion loss and the yield is high. Moreover, it is possible to obtain toner particles using a polyester resin having a sharp particle size distribution as a binder resin. Further, since the toner particles are obtained by coalescence, it is possible to provide a manufacturing method excellent in productivity, which can be manufactured in a short time without heating spherical or substantially spherical particles.

[Brief description of drawings]

FIG. 1 is a diagram for explaining how to obtain a flow tester value, in which (a) is a side sectional view showing an outline of a measuring device,
(B) is a graph for explaining a method of obtaining each flow tester value from the measured value.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H005 AA01 AA06 AB03 CA08 CA14                       CA23 EA03 EA06                 4G035 AB38 AB40

Claims (11)

[Claims] 1. An emulsification step of forming fine particles of the mixture in the aqueous medium by emulsifying a mixture containing at least a polyester resin and an organic solvent in the aqueous medium, and then adding a dispersion stabilizer, Further, a method for producing a toner for developing an electrostatic charge image, which comprises producing a toner by performing a coalescence step of coalescing the fine particles by sequentially adding an electrolyte. 2. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the emulsification step is performed by a production apparatus having a stirring blade whose tip rotates at a peripheral speed of 0.2 to 10 m / s. 3. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the coalescence step is performed by a production apparatus having a stirring blade whose tip rotates at a peripheral speed of 0.2 to 10 m / s. 4. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the dispersion stabilizer is an anionic and / or a nonionic surfactant. 5. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the electrolyte is a sulfate compound containing a monovalent cation. 6. The T1 / 2 temperature of the polyester resin by a constant load extrusion type thin tube rheometer is 120-1.
The method for producing an electrostatic charge image developing toner according to claim 1, wherein the temperature is in the range of 60 ° C., and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 12 or more. 7. The toner for developing an electrostatic charge image according to claim 1, wherein the polyester resin contains a plurality of polyester resins having different T1 / 2 temperatures measured by a constant load extrusion type capillary rheometer. Manufacturing method. 8. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the polyester resin is an acid group-containing polyester resin. 9. The method for producing an electrostatic charge image developing toner according to claim 1, wherein the emulsifying step is performed in the presence of a basic compound. 10. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the mixture contains a release agent. 11. The toner for developing an electrostatic charge image according to claim 10, wherein the release agent comprises at least one release agent selected from natural ester wax, synthetic ester wax and Fischer-Tropsch wax. Manufacturing method.