JP2008070703A - Method for manufacturing electrostatic charge image developing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing electrostatic charge image developing toner, by which durability of a filter is improved as well as toner leakage to a filtrate side is prevented so as not to save the cost of processing waste water in the production of a polymerization toner with high picture quality and a narrow distribution, charging characteristics with lapse of time are stabilized, and in particular, no significant decrease in charging property is induced even under high temperature/high humidity conditions but stable images can be obtained; and to provide the electrostatic charge image developing toner obtained by the method. <P>SOLUTION: The method for manufacturing the electrostatic charge image developing toner, including a step of solid-liquid separation through a synthetic resin filter, is characterized in that: an air flow rate of the filter and the toner particle diameter satisfy T/Dv<10 and T/(Dv/Dn)<SP>10</SP>>1, wherein T represents the air flow amount (cc/cm<SP>2</SP>min) and Dv represents a volume average particle diameter (μm) of the toner particles, Dv/Dn represents a ratio of the volume average particle diameter (Dv) to number average particle diameter (Dn). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing an electrostatic charge image developing toner.

  In the toner by the conventional pulverization method, the resin colorant dispersion in which the colorant is dispersed in the binder resin must be sufficiently brittle and can be pulverized by an economically possible manufacturing apparatus. There was a limit to the selection range.

When the resin colorant dispersion is made brittle to satisfy these requirements, the particle size range of the formed particles is widened when the dispersion is actually finely pulverized at a high speed. The toner obtained from is susceptible to further powdering in a developing device such as a copying machine.
In such a case, the colorant is exposed on the fracture surface of the toner particles, causing a change in development characteristics and causing image formation defects such as image density reduction and fogging.

  In recent years, methods for producing toner particles in a liquid medium, for example, a suspension polymerization method, an emulsion polymerization method, and an emulsion aggregation method have been proposed in order to overcome these problems of the pulverization method. Since these methods do not include a pulverization step, the toner does not need to be brittle, a soft material can be used as a resin, and the colorant is not exposed to the surface of the particles, and the toner is uniform. There is an advantage that a toner having frictional charging properties can be obtained.

  However, the toner directly generated in the liquid medium is susceptible to the influence of the medium on the toner surface. For example, when the dispersion medium is an aqueous medium, generally a polar resin or a charge control agent having a high polarity is localized near the toner surface. It becomes easy to exist. As a result, compared with pulverized toner, a very small amount of charge control agent can impart uniformly high chargeability to the toner. However, a highly polar material such as a charge control agent is a very small part, Some may dissolve in aqueous media. Therefore, great care must be taken in the step of filtering the toner particles from the liquid dispersion medium after completion of the toner particle generation reaction.

As a method for uniformly filtering the polymerized toner from the dispersion, a method of solid-liquid separation through a filter is generally used, and many apparatuses for carrying out these have been proposed (Patent Documents 1 to 3). 7).
However, the polymerized toner is liable to generate fine powder during granulation, and the dispersion containing such fine powder causes clogging of the filter. A clogged filter makes it difficult for washing water to flow, and not only the washing efficiency is lowered, but also a portion having a high moisture content is likely to be generated locally.When a cake in such a state is dried, the surface condition of the toner is not good. As a result, the toner charge amount distribution becomes broad, and fogging, toner scattering, image density reduction, and the like are likely to occur particularly in an environment where the toner is difficult to be charged, such as under high humidity.

  In addition, a filter clogged with fine powder does not recover its function even if it is washed with high-pressure water or the like, and needs to be replaced with a new one, which causes a problem of running costs. On the other hand, when using a filter that is difficult to clog (a filter with coarse eyes), it can be used repeatedly for a long time, but there is a problem that toner leaks to the filtrate side every time and wastewater treatment costs increase. is there.

In order to avoid such problems, it is conceivable to select and use an appropriate filter according to the properties of the treatment solution. However, there are numerous filter types depending on differences in material, weaving method, thickness, surface treatment, etc. Therefore, it is difficult to make a general decision because the mesh opening differs depending on the material and weaving method.
As an index for selecting a filter, an air flow rate (JIS L 1096 Frazier method) is generally used. However, Patent Document 2 states that an air flow rate of 10 to 1000 cc / cm ² · min can be applied, but the range is wide. Too substantial. In Patent Document 3, a filter is arbitrarily selected, but problems such as actual clogging and toner leakage are not taken into consideration. In Patent Documents 5 and 6, there is no particular description about the ventilation rate of the filter.

Moreover, in patent document 4, although the method of maintaining a degree of vacuum and improving filtration performance by prescribing | regulating the thickness of a filter is proposed, there is no description regarding clogging.
In Patent Document 1, it is proposed that clogging or toner particle passage hardly occur by using a filter having an air flow rate of ² to 40 cc / cm ² · min in solid-liquid separation by a filter press method. Since the influence of particle size and particle size distribution is not taken into consideration, it is not a condition that can be used repeatedly on the production line.
In Patent Document 7, the air flow rate is ² to 40 cc / cm ² by pressure filtration using a filter press.
A method for producing a toner having a volume average particle diameter Dv of 3 to 8 μm using a filter of min has been proposed, but as a result of investigation, an unfavorable range is selected in terms of clogging and toner particle passage. In some cases, even within the range, toners having different particle size distributions cannot be processed under the same conditions, and the filter is frequently replaced on the production line, resulting in a decrease in production efficiency.

Japanese Patent No. 3684075 JP 2003-012716 A JP 2003-164712 A JP 2003-223015 A JP 2004-279383 A JP 2004-302098 A JP 2006-106706 A

  The purpose of the present invention is to improve the durability of the filter in the production of high-quality narrow distribution polymerized toner, and to prevent the toner leakage to the filtrate side and avoid wastewater treatment costs. In particular, to provide a method for producing an electrostatic charge image developing toner capable of obtaining a stable image without significant reduction in chargeability even under high temperature / high humidity, and an electrostatic charge image developing toner obtained by the production method. is there.

  As a result of intensive studies, the present inventors have obtained characteristic values obtained from the relationship between the toner particle diameter and the air flow rate of the filter when the toner particles generated in the liquid medium are solid-liquid separated through a filter. The inventors have found that the durability of the filter and the toner leakage to the filtrate side are greatly affected, and the present invention has been completed.

That is, according to the present invention, the following (1) to (13) are provided.
(1) In a method for producing an electrostatic charge image developing toner comprising a step of solid-liquid separation through a synthetic resin filter from toner particles containing at least a binder resin and a colorant dispersed in a liquid medium. Airflow and toner particle size
T / Dv <10
and,
T / (Dv / Dn) ¹⁰ > 1
[T is the air flow rate (cc / cm ² · min),
Dv is the volume average particle diameter (μm) of the toner particles,
Dv / Dn represents the ratio of the volume average particle diameter (Dv) to the number average particle diameter (Dn)]
This is a method for producing a toner for developing an electrostatic image characterized by satisfying the above relationship.

(2) The binder resin is composed of a modified polyester resin capable of reacting with active hydrogen in an organic solvent, and a toner composition containing the binder resin is dissolved or dispersed, and the dissolved or dispersed material is dispersed into resin fine particles. A method for producing a toner which is dispersed in an aqueous medium and then reacted with a compound having an active hydrogen group, and the toner particles are solid-liquid separated from the obtained dispersion and dried. The method for producing a toner for developing an electrostatic charge image according to (1) above, wherein the relationship between the air flow rate of the filter and the toner particles is satisfied.

(3) The method for producing a toner for developing an electrostatic charge image according to (1) or (2) above, wherein the thickness of the synthetic resin filter for solid-liquid separation is 0.5 to 1.5 mm.
(4) The method for producing a toner for developing an electrostatic charge image according to any one of (1) to (3), wherein a material of the synthetic resin filter for solid-liquid separation is polypropylene.
(5) The method for producing a toner for developing an electrostatic charge image according to any one of (1) to (4), wherein the device used in the solid-liquid separation step is a filter press (pressure filtration method). is there.
(6) The electrostatic charge image developing toner production method according to any one of (1) to (4), wherein the device used in the solid-liquid separation step is a centrifugal filter (centrifugal filtration method). is there.
(7) The electrostatic charge image developing toner production method according to any one of (1) to (4), wherein the device used in the solid-liquid separation step is a vacuum belt filter (vacuum filtration method). is there.

(8) The toner for developing an electrostatic charge image according to any one of (1) to (7), wherein the toner particles have a volume average particle diameter Dv of 3 to 8 μm.
(9) The electrostatic image developing toner according to any one of (1) to (8), wherein Dv / Dn is 1.40 or less.

(10) The method for producing a toner for electrostatic charge development according to (5), wherein the solid-liquid separation is performed by the filter press, followed by pressing and washing from the filter side.
(11) The method for producing a toner for electrostatic charge development according to (10) above, wherein the moisture content of the cake after solid-liquid separation is 35 to 45% by weight.
(12) The method for producing a toner for electrostatic charge development according to (11), wherein a charge control agent is added after the cake is dispersed in water.
(13) The method for producing a toner for developing an electrostatic charge according to (12) above, wherein the dispersion is subjected to solid-liquid separation with a centrifugal filter, and the moisture content of the cake after dehydration is 20 to 35% by weight.

Details of the present invention will be described below.
In the present invention, in a method for producing a toner for developing an electrostatic charge image comprising a step of solid-liquid separation through a synthetic resin filter from toner particles containing at least a binder resin and a colorant dispersed in a liquid medium, The air flow rate of the filter and the toner particle size
T / Dv <10
and,
T / (Dv / Dn) ¹⁰ > 1
[T is the air flow rate (cc / cm ² · min),
Dv is the volume average particle diameter (μm) of the toner particles,
Dv / Dn represents the ratio of the volume average particle diameter (Dv) to the number average particle diameter (Dn)]
It is characterized by satisfying the relationship.

In the present invention, as a toner containing at least a binder resin and a colorant dispersed in the liquid medium, a toner component containing the resin is dissolved or dispersed in an organic medium, and the dissolved or dispersed substance is dispersed in an aqueous medium. Emulsified / dispersed, and at least a monomer and a colorant are added in an aqueous medium, and this is emulsified / dispersed and polymerized (polymerized toner dispersion). Further, there may be mentioned those in which fine particles of other toner components are added and aggregated together (another type of polymerized toner dispersion).

When toner particles are solid-liquid separated from the liquid medium through a synthetic resin filter, the relationship between the filter air flow rate and the toner particle size is
T / Dv <10 and T / (Dv / Dn) ¹⁰ > 1
By using a filter that satisfies this condition, there is almost no toner leakage to the filtrate side, and clogging is unlikely to occur even when used repeatedly for a long time. T / Dv <10 is defined from the particle size that can be supplemented, and T / (Dv / Dn) ¹⁰ > 1 is defined from the particle size distribution and ease of clogging (lifetime).
A more preferred range is
3 <T / Dv <9 and 20> T / (Dv / Dn) ¹⁰ > 2
It is. If it is this range, even after repeated use, there will be little fall of the air flow rate by clogging. Further, the amount of toner leaking to the filtrate side can be further reduced.

The thickness of the synthetic resin filter is preferably 0.5 to 1.5 mm.
If the thickness exceeds 1.5 mm, the flexibility of the filter is impaired, and if it is folded or bent when assembled to the apparatus or carried, it is likely to cause a problem that a hole opens and toner leaks therefrom.
On the other hand, if the thickness is less than 0.5 mm, there is a drawback that it is deteriorated and broken by repeated use.

The material of the synthetic resin filter is preferably polypropylene. Compared to natural fibers such as nylon, acrylic and vinylon, and natural fibers such as cotton and wool, it has acid resistance and alkali resistance, and is also resistant to organic solvents and chemicals. And there is little deterioration of the fibers constituting the filter cloth.
Furthermore, since the breaking strength is large and the specific gravity is small, when compared with a filter cloth having the same filtration area, the weight can be reduced, so that the burden on the operator during carrying and assembly is reduced.

  Filter press (pressure filtration system), centrifugal filter (centrifugal filtration system), and vacuum belt filter (vacuum filtration system) are suitable as the equipment for solid-liquid separation through a synthetic resin filter. By doing so, the filter cloth is not clogged even if it is used repeatedly for a long time, and the stop time of the production line due to the replacement work of the filter cloth can be greatly shortened.

  The volume average particle diameter Dv of the toner particles dispersed in the liquid medium is preferably 3 to 8 μm. If the volume average particle diameter is within this range, the processing speed of solid-liquid separation does not become extremely slow, and the production efficiency is high. When Dv is less than 3 μm, not only the processing speed of solid-liquid separation is extremely slow, but also the powder obtained after crushing the solid-liquid separation is soared as dust, which reduces workability. When Dv exceeds 8 μm, the treatment speed becomes extremely fast, the cake cracks immediately, and the treatment of flowing washing water through the cake cannot be performed.

  Further, when the ratio Dv / Dn of the volume average particle diameter (Dv) to the number average particle diameter (Dn) of the toner particles is 1.40 or less, the solid-liquid separation processing speed can be maintained appropriately, and then the pressure is increased. It is possible to squeeze and add air to blow off excess moisture, so that the amount of heat energy consumed in subsequent drying can be suppressed, and the processing efficiency is high.

After performing solid-liquid separation with a filter press (pressure filtration method), it is preferable to continuously perform dewatering by pressing and then wash with a method of supplying water from the filter side.
Since the dewatered state of the cake separated by filtration is uniform in the thickness direction, cracking of the cake is difficult to occur, and when wash water is poured from the filter side to this cake, the wash water is evenly distributed in the cake, Unevenness is less likely to occur and cleaning efficiency is good. Further, it is preferable in that the surface state of the toner before filtering can be maintained even after filtering.

  The pressing pressure of the filter press is preferably 0.1 to 1.0 MPa. When the pressing pressure is less than 0.1 MPa, not only the filtration efficiency is lowered, but also the cake in the filtration chamber is not applied with a uniform pressure, and the uniform filtration becomes difficult. On the other hand, when the pressure exceeds 1.0 MPa, the toner particles are deformed and the cleaning property is impaired, which is not preferable.

It is preferable that the moisture content of the cake after the solid-liquid separation is 35 to 45% by weight because the cake is quickly dispersed when the cake is dispersed in the aqueous medium.
When the water content exceeds 45% by weight, adsorption of impurities in the atmosphere and moisture absorption are likely to occur, resulting in deterioration of toner surface properties.
Further, as a method of reducing the moisture content, there is a method of aerating the cake.
If the water content is reduced to less than 35% by aeration, toner particles coalesce due to pressure, aggregates increase, and a dispersion obtained by dispersing the cake in an aqueous medium is obtained. There is a disadvantage of non-uniform dispersion.

  A charge control agent may be added after the cake is dispersed in water. In particular, when a highly polar material is used as the charge control agent, after dispersing in acidic water, filtering off by pressure filtration, dispersing the resulting cake in pure water, and then adding, the toner has good charging characteristics. .

  Known charge control agents can be used, for example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified). Quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives.

  In the present invention, the amount of the charge control agent used is determined by the type of the binder resin and, if necessary, the toner production method including the dispersion method, and is not uniquely limited. It is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, reducing the effect of the charge control agent, increasing the electrostatic attractive force with the developing roller, reducing the fluidity of the developer, and reducing the image density. Invite.

  As a method of dispersing the cake obtained by the filter press in an aqueous medium and solid-liquid separating the toner particles from the obtained dispersion, centrifugal filtration is used, and the moisture content of the cake is 20 to 35% by weight. The operation efficiency of the next drying treatment is improved, and as a result, the quality of the toner can be remarkably improved, which is preferable.

  As a device for centrifugal filtration, specifically, a basket type centrifugal filter (Matsumoto Machinery Co., Ltd., Tanabe Wiltech, Mitsubishi Chemical), a siphon pillar type centrefuge (Mitsubishi Chemical), or a vertical decanter (Niigata Washington) It is suitable to process using.

In centrifugal filtration, the moisture content of the cake separated by filtration can be reduced in a short time, so that adsorption of impurities in the atmosphere can be suppressed, and the control shape can be maintained without impairing the charging property of the toner.
The centrifugal effect of centrifugal filtration is preferably 500 to 1500G.
If the centrifugal effect is less than 500G, the filtration efficiency is reduced. On the other hand, when it exceeds 1500G, the cake layer is cured, and it becomes difficult to peel the cake from the filter.
The cake separated by centrifugal filtration is dried by a dryer such as a fluidized bed dryer, a flash dryer, a circulating dryer, or a vacuum dryer to obtain toner particles.

The processing of the toner particles after drying, the particle size, shape, material, etc. of the toner particles will be described below.
Henschel mixer, super mixer, high speed mixer, Q-type mixer, etc. can be used to produce toner by mixing toner particles after drying and external additives. it can.

As an external additive for assisting fluidity, developability and chargeability, inorganic fine particles can be preferably used. The primary particle diameter of the inorganic fine particles is preferably 5 nm to 1000 nm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The proportion of the inorganic fine particles used is preferably 0.01 to 5% by weight of the toner, and particularly preferably 0.01 to 2.0% by weight.

  Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Other polymer fine particles such as polystyrene, methacrylic acid ester, acrylic acid ester copolymer obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, polycondensation system such as silicone, benzoguanamine, nylon, thermosetting resin, etc. Examples include polymer particles.

  As a method for producing toner particles in a liquid medium, a toner composition containing a toner binder composed of a modified polyester resin capable of reacting with active hydrogen is dissolved or dispersed in an organic solvent, and the dissolved or dispersed material is dispersed into resin fine particles. It is preferable to disperse in a water-based medium containing, and then react with a compound having an active hydrogen group which is a crosslinking agent and / or an elongation agent.

  The average circularity of the toner particles and the amount of fine powder of less than 2 μm are very important factors for the cleaning property, and in order to achieve compatibility with the fixability, the amount of fine powder is appropriately controlled, and further 0.60 μm or more. It is important to control the circularity of particles having a particle size range of less than 00 μm. As a result of intensive studies, the average circularity is 0.940 or more and less than 0.990, and particles having a particle size range of 0.60 μm or more and less than 2.00 μm are 10% or more and less than 50% on a number basis, If the average circularity in the particle size range is 0.930 or less, the cleaning property is good and no cold offset occurs.

  The volume average particle diameter Dv of the toner particles is preferably 3 to 8 μm. Further, by satisfying the range of the above particle size distribution and circularity, transfer quality due to coarse particles does not occur and image quality is good.

Measurement of the number% of particles whose circularity and equivalent circle diameter are in a particle size range of 0.60 μm or more and less than 2.00 μm on the basis of the number is measured using a flow type particle image analyzer FPIA-1000 manufactured by SYSMEX. can do. An outline of the apparatus and measurement is described in JP-A-8-136439.
The measurement was adjusted to a 1% NaCl aqueous solution using primary sodium chloride and then passed through a 0.45 μm filter to 50 to 100 ml of a surfactant, preferably 0.1 to 5 ml of an alkylbenzene sulfonate as a dispersant. In addition, add 1-10 mg of sample. This is subjected to dispersion treatment for 1 minute with an ultrasonic disperser, and measurement is performed using a dispersion liquid in which the particle concentration is adjusted to 5000 to 15000 particles / μl. For the measurement of the number of particles, a two-dimensional image area captured by a CCD camera and a diameter of a circle having the same area are calculated as an equivalent circle diameter. From the accuracy of the CCD pixel, a circle equivalent diameter of 0.6 μm or more is effective and particle measurement data is obtained.

  The volume average particle diameter Dv and the number average particle diameter Dn are measured by using an interface (manufactured by Nikka) and a PC9801 personal computer (manufactured by NEC) that output the number distribution and volume distribution to the Coulter Counter TAII manufactured by Coulter Electronics, USA. Connect and use. The electrolyte is adjusted to 1% NaCl aqueous solution using first grade sodium chloride. As a measuring method, 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 50 to 100 ml of the electrolytic solution, and 1 to 10 mg of a sample is added. This is subjected to a dispersion process for 1 minute with an ultrasonic disperser. In another beaker, 100 to 200 ml of an electrolytic aqueous solution is added, and the sample dispersion is added to a predetermined concentration, and the Coulter Counter TAII type uses an aperture of 100 μm as an aperture and 2 to 40 μm based on the number. The particle size distribution of 30000 particles is measured, the volume distribution and number distribution of 2 to 40 μm particles are calculated, and the volume average particle size (Dv: the median value of each channel is the representative value of the channel) is obtained.

  In the toner manufacturing method of the present invention, parts other than the filtration treatment will be described. For example, it is specifically performed as follows.

(Resin fine particles)
The resin fine particles used in the present invention preferably have a glass transition point (Tg) of 50 to 90 ° C. When the glass transition point (Tg) is less than 50 ° C., the toner storage stability is deteriorated and stored. Blocking occurs at times and in the developing machine. When the glass transition point (Tg) is higher than 90 ° C., the resin fine particles inhibit the adhesiveness with the fixing paper, and the minimum fixing temperature is increased. A more preferred range is 50 to 70 ° C. The weight average molecular weight is desirably 100,000 or less. Preferably it is 50,000 or less. The lower limit is usually 4000. When the weight average molecular weight exceeds 100,000, the resin fine particles inhibit the adhesiveness with the fixing paper, and the minimum fixing temperature increases.

  The resin fine particles may be any resin as long as it can form an aqueous dispersion, and may be a thermoplastic resin or a thermosetting resin. For example, vinyl resin, polyurethane resin, epoxy resin, polyester resin, polyamide resin, polyimide Examples thereof include resins, silicon-based resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonate resins. As the resin fine particles, two or more of the above resins may be used in combination. Among these, those made of a vinyl resin, a polyurethane resin, an epoxy resin, a polyester resin, or a combination resin thereof are preferable because an aqueous dispersion of fine spherical resin particles is easily obtained. Vinyl resins are polymers obtained by homopolymerization or copolymerization of vinyl monomers, such as styrene- (meth) acrylic acid ester copolymers, styrene-butadiene copolymers, (meth) acrylic acid-acrylic acid ester copolymers. Examples thereof include a polymer, a styrene-acrylonitrile copolymer, a styrene-maleic anhydride copolymer, and a styrene- (meth) acrylic acid copolymer. In the resin fine particles, the average particle size is preferably 5 to 200 nm, more preferably 20 to 300 nm.

(Binder resin)
A conventional general material can be used as the binder resin. Conventionally, binder resins used for toner production include, for example, polyester resins, styrene resins, acrylic resins, epoxy resins, and the like. In ordinary toners, among these, copolymers of styrene and acrylate esters are used. The most commonly used resin. Polyester resins are excellent in low-temperature fixability and storage stability due to the low softening temperature of the binder resin and high glass transition point. Further, since the affinity between the ester bond of the polyester resin and the paper is good, the toner has excellent offset resistance.

  The polyester resin used as the main component of the binder resin of the toner for developing an electrostatic charge image of the present invention is synthesized by a condensation reaction of an acid component and an alcohol component, or a ring-opening reaction of a cyclic ester, or a halogen compound and Synthesized with alcohol component and carbon monoxide. In the method for producing a toner for developing an electrostatic charge image of the present invention, the above-mentioned excellent physical properties are obtained by polymerizing a combination of the above-mentioned monomers serving as a polyester resin synthetic material in the above-mentioned resin fine particle solution. The toner for developing an electrostatic charge image of the present invention can be easily obtained. Hereinafter, various monomers used as a synthetic material for the polyester resin will be described.

  First, as the alcohol component and the acid component, those having a valence of 2 or more are preferably used. For example, as the divalent alcohol, ethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentylene glycol, 1,4-butenediol, 1 Diols such as 1,5-pentanediol and 1,6-hexanediol; bisphenol A, hydrogenated bisphenol A, α, α′-bis (4-hydroxyphenyl) -1,4-diisopropylbenzene, polyoxyethylenated bisphenol A, and bisphenol A alkylene oxide adducts such as polyoxypropylenated bisphenol A.

  Examples of the divalent acid include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malon Examples include acids and other divalent organic acids. Examples of the trivalent acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, and 2,5,7-naphthalenetricarboxylic acid. 1,2,5-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-carboxymethylpropane, tetra (carboxymethyl) methane, 1,2,7 , 8-octanetetracarboxylic acid. Acid anhydrides and acid halides of these organic acids are also preferred acid components for synthesis.

  In the present invention, it is preferable to use a polyester resin having at least an aromatic ring in one of the acid component and alcohol component listed above. In the present invention, the total amount of the acid component and the alcohol component, which are the synthetic components of the polyester resin, is 1 to 30 parts by weight, preferably 1.5 parts by weight based on 1 part by weight of the resin fine particles described above. It is preferable to use it in the range of 10 parts by weight to 10 parts by weight.

  Moreover, the usage ratio of the acid component and the alcohol component is in the range of 0.9 to 1.5 molar equivalents, preferably 1.0 to 1.3 molar equivalents of alcohol groups with respect to 1 molar equivalent of carboxyl groups. preferable. In addition, as a carboxyl group here, the halide which is a compound corresponded to the acid component quoted above is also included. As other additives, an amine component may be used. Specific examples include triethylamine, trimethylamine, N, N-dimethylaniline and the like. Moreover, you may react using another condensing agent, for example, dicyclohexylcarbodiimide etc.

(Modified polyester capable of reacting with compounds having active hydrogen groups)
A reactive modified polyester resin (RMPE) that can react with a compound having an active hydrogen group (hereinafter, the polyester resin is also simply referred to as polyester) has, for example, a functional group that reacts with active hydrogen such as an isocyanate group. Polyester prepolymers and the like are included. The polyester prepolymer preferably used in the present invention is a polyester prepolymer (A) having an isocyanate group. This polyester prepolymer (A) having an isocyanate group is a polycondensate of a polyol (PO) as an alcohol component and a polycarboxylic acid (PC) as an acid component, and reacts with a polyisocyanate (PIC) to a polyester having an active hydrogen group. Manufactured by making. Examples of the active hydrogen group possessed by the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like. Among these, alcoholic hydroxyl groups are preferred.

Examples of the polyol include diol (DIO) and trivalent or higher polyol (TO), and DIO alone or a mixture of DIO and a small amount of TO is preferable. Particularly preferred as the diol are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use.
Examples of the trihydric or higher polyol include 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (trisphenol PA, Phenol novolak, cresol novolak, etc.); alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polycarboxylic acid (PC) include dicarboxylic acid (DIC) and trivalent or higher polycarboxylic acid (TC), and DIC alone or a mixture of DIC and a small amount of TC is preferable. Particularly preferred as dicarboxylic acids are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher valent polycarboxylic acid include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polycarboxylic acid, you may make it react with a polyol using the acid anhydride or lower alkyl ester (methyl ester, ethyl ester, isopropyl ester, etc.) of the above-mentioned thing.

  The ratio of the polyol and the polycarboxylic acid is usually 2/1 to 1/1, preferably 1.5 / 1 to 1/1 / as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. 1, more preferably 1.3 / 1 to 1.02 / 1.

  As polyisocyanate (PIC), aliphatic polyisocyanate (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanate (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.); aromatic Diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; the polyisocyanates such as phenol derivatives, oximes, caprolactams, etc. And a combination of two or more of these.

  The ratio of the polyisocyanate is usually 5/1 to 1/1, preferably 4/1 to 1 as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. .2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. If the molar ratio of [NCO] is less than 1, the urea content in the modified polyester will be low, and the hot offset resistance will deteriorate. The content of the polyisocyanate (PIC) component in the prepolymer (A) having an isocyanate group at the terminal is usually 0.5 to 40% by weight, preferably 1 to 30% by weight, more preferably 2 to 20% by weight. It is. If it is less than 0.5% by weight, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40% by weight, the low-temperature fixability deteriorates.

  From the polyester prepolymer (A) having an isocyanate group, a urea-modified polyester resin (UMPE) can be obtained by reacting this with an amine (B). This exhibits an excellent effect as a toner binder resin.

  If necessary, the molecular weight of a modified polyester such as urea-modified polyester can be adjusted using an elongation terminator. Examples of the elongation terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

  The ratio of amines (B) is the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). The ratio is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated. In the present invention, the polyester modified with a urea bond may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

  The urea-modified polyester used in the present invention is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the modified polyester such as urea-modified polyester is usually 10,000 or more, preferably 20,000 to 10,000,000, and more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of a modified polyester such as urea-modified polyester is not particularly limited when an unmodified polyester described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. In the case of a modified polyester alone such as urea-modified polyester, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color apparatus are deteriorated.

(Unmodified polyester)
In the present invention, not only a modified polyester (MPE) such as a polyester modified with a urea bond, but also a polyester (PE) that is not modified can be included as a toner binder resin component. . The combined use of PE improves low-temperature fixability and gloss when used in a full-color device, and is preferable to single use. Examples of PE include a polycondensate of a polyol component and a polycarboxylic acid component, which are the same as the polyester component of MPE, and preferred ones are also the same as MPE. In addition, PE may be modified with a chemical bond other than an unmodified polyester, and may be modified with a urethane bond, for example. It is preferable that MPE and PE are at least partially compatible in terms of low-temperature fixability and hot offset resistance. Therefore, a similar composition is preferable for the polyester component of MPE and PE. When PE is contained, the weight ratio of MPE to PE is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, and particularly preferably 7/93. ~ 20/80. If the weight ratio of MPE is less than 5%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

The peak molecular weight of PE is usually 1000-30000, preferably 1500-10000, more preferably 2000-8000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of PE is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of PE is usually 1-30, preferably 5-20. By having an acid value, it tends to be negatively charged.

  In the present invention, the glass transition point (Tg) of the binder resin (toner binder) in the toner is usually 50 to 70 ° C., preferably 55 to 65 ° C. If the temperature is less than 50 ° C., the heat-resistant storage stability of the toner deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Due to the coexistence of a modified polyester such as a urea-modified polyester resin, the dry toner of the present invention tends to have good heat storage stability even when the glass transition point is low, as compared with known polyester toners.

(Coloring agent)
As the colorant used in the present invention, known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow oxidation Iron, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Faisa Red, Parachlor Rutonitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carnmin BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, thioindigo red B, thioindigo maroon, oil red, quinacridone red, pyrazo Red, polyazo red, chrome vermillion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue rake, peacock blue rake, Victoria blue rake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indance Ren Blue (RS, BC), Indigo, Ultramarine Blue, Bituminous Blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian, Emerald Green , Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green , Phthalocyanine green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used.
The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

The colorant used in the present invention can also be used as a master batch combined with a resin. As the binder resin to be kneaded together with the production of the masterbatch or the masterbatch, in addition to the modified and unmodified polyester resins mentioned above, styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene, and polymers of substituted products thereof; Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α- Chloromethyl methacrylate copolymer, Tylene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-malein Styrene copolymers such as acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, poly Acrylic resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. The

(Release agent)
The toner of the present invention may contain a binder resin (toner binder) and a wax as a release agent together with a colorant. Known waxes can be used, for example, polyolefin wax (polyethylene wax, Polypropylene wax, etc.); long chain hydrocarbons (paraffin wax, sazol wax, etc.); carbonyl group-containing waxes. Of these, carbonyl group-containing waxes are preferred. Examples of the carbonyl group-containing wax include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18. -Octadecanediol distearate, etc.); polyalkanol esters (tristearyl trimellitic acid, distearyl maleate, etc.); polyalkanoic acid amides (ethylene diamine dibehenyl amide, etc.); polyalkylamides (trimellitic acid tristearyl amide, etc.) And dialkyl ketones (such as distearyl ketone).
Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred.

The melting point of the wax of the present invention is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C. A wax having a melting point of less than 40 ° C. has an adverse effect on heat resistant storage stability, and a wax having a melting point of more than 160 ° C. tends to cause a cold offset when fixing at a low temperature. Further, the melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps have poor effects for improving hot offset resistance and low-temperature fixability.
The content of the wax in the toner is usually 0 to 40% by weight, preferably 3 to 30% by weight.

(Method for producing toner binder resin)
The toner binder resin can be produced, for example, by the following method. Polyester having a hydroxyl group by heating the polyol and polycarboxylic acid to 150-280 ° C. in the presence of a known esterification catalyst such as tetrabutoxy titanate, dibutyltin oxide, etc., and distilling off the water generated while reducing the pressure as necessary. Get. Next, this is reacted with polyisocyanate at 40 to 140 ° C. to obtain a prepolymer (A) having an isocyanate group. Further, this (A) is reacted with amines (B) at 0 to 140 ° C. to obtain a polyester modified with a urea bond. When the polyisocyanate is reacted and when (A) and (B) are reacted, a solvent can be used if necessary. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to polyisocyanates (PIC) such as tetrahydrofuran (such as tetrahydrofuran). When using a polyester (PE) not modified with a urea bond, this PE is produced in the same manner as in the case of a polyester having a hydroxyl group, and this is dissolved in a solution after completion of the reaction of the urea-modified polyester. Mix.

(Toner production method in aqueous medium)
The dry toner of the present invention can be produced by the following method, but is not limited thereto.
First, as the aqueous medium, water alone may be used, but a solvent miscible with water may be used in combination. Examples of the miscible solvent include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), and the like.

  The toner particles can be formed by reacting a dispersion composed of a prepolymer (A) having an isocyanate group with an amine (B) in an aqueous medium. As a method for stably forming a dispersion composed of urea-modified polyester or prepolymer (A) in an aqueous medium, the composition of a toner raw material composed of urea-modified polyester or prepolymer (A) is added to the aqueous medium. And a method of dispersing by shearing force. The colorant, colorant masterbatch, release agent, charge control agent, unmodified polyester resin, etc. which are the prepolymer (A) and other toner components (hereinafter referred to as toner raw materials) are dispersed in an aqueous medium. It may be mixed at the time of formation, but it is more preferable to mix the toner raw materials in advance and then add and disperse the mixture in the aqueous medium. In the present invention, other toner raw materials such as a colorant, a release agent, and a charge control agent do not necessarily have to be mixed when forming particles in an aqueous medium. It may be added later. For example, after forming particles containing no colorant, the colorant can be added by a known dyeing method.

  The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. In order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing type is preferable. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C. Higher temperatures are preferred in that the dispersion of the urea-modified polyester or prepolymer (A) has a low viscosity and is easy to disperse. The amount of the aqueous medium used is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight, based on 100 parts by weight of the toner composition (composition) containing urea-modified polyester and prepolymer (A). If the amount is less than 50 parts by weight, the dispersed state of the toner composition is poor and toner particles having a predetermined particle size cannot be obtained. If it exceeds 20000 parts by weight, it is not economical. Moreover, a dispersing agent can also be used as needed. It is preferable to use a dispersant because the particle size distribution becomes sharp and the dispersion is stable.

  As a dispersant for emulsifying and dispersing the oily phase in which the toner composition is dispersed in a liquid containing water, an anionic surfactant such as alkylbenzene sulfonate, α-olefin sulfonate, and phosphate ester, Amine salt types such as alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazolines, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride Nonionic surfactants such as quaternary ammonium salt type cationic surfactants, fatty acid amide derivatives, polyhydric alcohol derivatives such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N- Al Le -N, amphoteric surfactants such as N- dimethyl ammonium betaine and the like.

Further, by using a surfactant having a fluoroalkyl group, the effect can be increased in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [omega-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [omega-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-hydroxyethyl Perfluorooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. As the product names, Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101, DS-102, (manufactured by Taikin Kogyo Co., Ltd.), Megafac F-l10, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), EX Top EF-102, 103, 104, 105, 112, 123A, 123B, 30 A, 501,201,204, (manufactured by Tochem Products Co., Ltd.), Ftergent F-100, F150 (manufactured by Neos Co., Ltd.).

  Cationic surfactants include aliphatic primary, secondary or tertiary amine acids having a fluoroalkyl group, aliphatic quaternary ammonium salts such as perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts, benzaza Luconium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass), Florard FC-135 (Sumitomo 3M), Unidyne DS-202 (Daikin Industries) , Megafac F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products Co., Ltd.), Footgent F-300 (Neos Co., Ltd.), and the like.

  In addition, calcium phosphate, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite, and the like can also be used as inorganic compound dispersants that are hardly soluble in water.

Further, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-chloroacrylate 2-hydroxypropyl, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or esters of compounds containing vinyl alcohol and a carboxyl group, For example, vinyl acetate, vinyl propionate, vinyl butyrate, etc., acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethyleneimine Homopolymers or copolymers such as those having a nitrogen atom, or a heterocyclic ring thereof, polyoxyethylene, polyoxypropylene, Reoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonylphenyl Polyoxyethylenes such as esters, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  In addition, when an acid such as calcium phosphate salt or an alkali-soluble one is used as the dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as washing with water after dissolving the calcium phosphate salt with an acid such as hydrochloric acid. To do. It can also be removed by operations such as enzymatic degradation. When a dispersant is used, the dispersant can remain on the surface of the toner particles. However, after the elongation and / or cross-linking reaction with the compound having an active hydrogen group, it is better to remove the toner by washing. From the aspect, it is preferable.

  Further, in order to lower the viscosity of the liquid containing the toner composition, a solvent in which the urea-modified polyester or the prepolymer (A) is soluble can be used. The use of a solvent is preferable in that the particle size distribution becomes sharp. The solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal. Examples of the solvent include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, Methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable. The usage-amount of the solvent with respect to 100 weight part of prepolymers (A) is 0-300 weight part normally, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part. When a solvent is used, it is removed by heating under normal pressure or reduced pressure after elongation and / or crosslinking reaction.

  When the crosslinking agent which is a compound having an active hydrogen group and / or amines (B) as an extender are reacted with a modified polyester capable of reacting with active hydrogen, the extension and / or cross-linking reaction time is determined depending on the prepolymer (A ) Is selected depending on the reactivity depending on the combination of the isocyanate group structure and amines (B), and is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

(Shape control process)
In order to obtain a desired shape, for example, an emulsified dispersion (oil phase) is mixed with a high-viscosity aqueous solution (aqueous phase) to which a thickener, an activator, or the like is added. By using a device that applies a shearing force such as a milder, the emulsified particles can be deformed by utilizing the difference in viscosity between the oil phase and the water phase. The conditions at this time include, for example, a method for adjusting the shearing force of the apparatus, for example, a method for adjusting the treatment time and the number of treatments, or a viscosity difference between the oil phase and the water phase, for example, a water-insoluble organic solvent in the oil phase. The desired shape can be controlled by optimizing the concentration, temperature, thickener in the aqueous phase, activator, temperature, etc.

(Solvent removal)
In order to remove the organic solvent from the obtained emulsified dispersion, a method in which the temperature of the entire system is gradually raised to completely evaporate and remove the organic solvent in the droplets can be employed. Alternatively, the emulsified dispersion can be sprayed into a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and the aqueous dispersant can be removed by evaporation together. . As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, in particular, various air currents heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used is generally used. Sufficient quality can be obtained with a short treatment such as spray dryer, belt dryer or rotary kiln.

(Image forming method, two-component carrier)
In the present invention, an image is formed by a one-component development method using the toner or by a two-component development method in which the toner is mixed with a carrier and frictionally charged. When used in combination with a magnetic carrier, the carrier to toner content ratio in the developer is preferably 1 to 10 parts by weight of toner with respect to 100 parts by weight of carrier. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used. These carrier particles may be coated, and examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene-acrylic copolymer resins, Halogenated olefin resin such as vinyl chloride, polyester resin such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexa Fluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride Fluoro such as terpolymers of emission and non-fluoride monomers including, and silicone resins. Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance.

  INDUSTRIAL APPLICABILITY The present invention can provide a method for producing a toner for developing an electrostatic charge image that is excellent in stability of charging characteristics, has little change over time particularly in a high temperature / high humidity environment, and does not cause image quality defects.

Hereinafter, the present invention will be described in more detail with reference to examples. The embodiment of the present invention is not limited to this. Parts and% are based on weight.
[Example 1]
[Production of developer]
First, the toner, carrier, and two-component developer composed of these used in this embodiment will be described.
The toner used in the examples was prepared by the method described below.

~ Synthesis of organic fine particle emulsion ~
In a reaction vessel equipped with a stirrer and a thermometer, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 83 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate and 1 part of ammonium persulfate were added and stirred at 400 rpm for 15 minutes, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours, and an aqueous vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). A dispersion [fine particle dispersion 1] was obtained. [Fine particle dispersion 1] LA
The volume average particle diameter measured at −920 was 105 nm. A portion of [Fine Particle Dispersion 1] was dried to isolate the resin component. The resin content had a Tg of 59 ° C. and a weight average molecular weight of 150,000.

-Adjustment of aqueous phase-
990 parts of water, 83 parts of [fine particle dispersion 1], 37 parts of a 48.5% aqueous solution of dodecyl diphenyl ether disulfonate (Eleminol MON-7): manufactured by Sanyo Chemical Industries, Ltd. and 90 parts of ethyl acetate were mixed and stirred. A liquid was obtained. This is designated as [Aqueous Phase 1].

~ Synthesis of low molecular weight polyester ~
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts terephthalic acid, 46 parts adipic acid and dibutyl Add 2 parts of tin oxide, react at 230 ° C for 8 hours at normal pressure, and further react for 5 hours at 10-15 mmHg reduced pressure, then add 44 parts of trimellitic anhydride to the reaction vessel at 180 ° C at normal pressure. The mixture was reacted for 2 hours to obtain [Low molecular weight polyester 1]. [Low molecular polyester 1] had a number average molecular weight of 2500, a weight average molecular weight of 6700, Tg of 43 ° C., and an acid value of 25.

~ Synthesis of intermediate polyester and prepolymer ~
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 And 2 parts of dibutyltin oxide were added, reacted at 230 ° C. for 8 hours at normal pressure, and further reacted for 5 hours at a reduced pressure of 10 to 15 mmHg to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, Tg of 55 ° C., an acid value of 0.5, and a hydroxyl value of 51.
Next, 410 parts of [Intermediate Polyester 1], 89 parts of isophorone diisocyanate and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Polymer 1] was obtained. [Prepolymer 1] had a free isocyanate weight% of 1.53%.

~ Synthesis of ketimine ~
In a reaction vessel equipped with a stir bar and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound 1].
The amine value of [ketimine compound 1] was 418.

~ Master batch synthesis ~
35 parts of water, 40 parts of phthalocyanine pigment (Toyo Ink, FG7351) and 60 parts of a polyester resin (manufactured by Sanyo Chemical Industries, RS801) are mixed with a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.), and the mixture is used at 150 ° C. using two rolls. After kneading for 30 minutes, it was rolled and cooled, and pulverized with a pulverizer to obtain [Masterbatch 1].

~ Creation of oil phase ~
In a container equipped with a stirrer and a thermometer, 378 parts of [Low molecular weight polyester 1], 110 parts of Carnauba WAX, 22 parts of CCA (salicylic acid metal complex E-84: Orient Chemical Industry), 947 parts of ethyl acetate were charged with stirring. The temperature was raised to 0 ° C., kept at 80 ° C. for 5 hours, and then cooled to 30 ° C. over 1 hour. Next, 500 parts of [Masterbatch 1] and 500 parts of ethyl acetate were charged in a container and mixed for 1 hour to obtain [Raw material solution 1]. [Raw material solution 1] 1324 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads are 80% by volume. The pigment and WAX were dispersed under the conditions of filling and 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of [low molecular weight polyester 1] was added, followed by one pass with a bead mill under the above conditions to obtain [Pigment / WAX Dispersion 1]. The solid content concentration of [Pigment / WAX Dispersion 1] (130 ° C., 30 minutes) was 50%.

~ Emulsification ~
[Pigment / WAX Dispersion 1] 648 parts, [Prepolymer 1] 154 parts, [Ketimine Compound 1] 6.6 parts in a container, and TK homomixer (made by Tokushu Kika) at 5,000 rpm for 1 minute After mixing, 1200 parts of [Aqueous phase 1] was added to the container, and mixed with a TK homomixer at 13,000 rpm for 20 minutes to obtain [Emulsion slurry 1].

~ Shape control ~
[Emulsified slurry 1] is mixed in an aqueous solution in which ion-exchanged water, activator, and thickener are put in a container at an appropriate ratio and stirred, and mixed at 2,000 rpm for 1 hour with a TK homomixer (manufactured by Tokushu Kika). [Shape control slurry 1] was obtained.

~ Solvent removal ~
[Shape control slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging was carried out at 45 ° C. for 4 hours to obtain [Dispersion slurry 1].

~Washing~
[Dispersion Slurry 1] 100 parts were filtered out with a filter press assembled with a filter cloth having a filter air flow rate of 50 cc / cm ² · min, a material of polypropylene, and a thickness of 0.7 mm. It dehydrated and [filter cake 1] was obtained.

~ Dry ~
[Filtration cake 1] was dried at 45 ° C. for 48 hours in a circulating drier, and sieved with a mesh having a mesh size of 75 μm to obtain final [toner base particles 1].

~ Adding external additives ~
Next, 0.7 part of hydrophobic titanium oxide having an average particle size of 0.3 μm was mixed with 100 parts of [toner base particle 1] with a Henschel mixer at a peripheral speed of a stirring blade of 20 m / s. ] Has been created.

(Examples 2 to 10, Comparative Examples 1 to 5)
In the toners of Examples 2 to 8 and Comparative Examples 1 to 5, the TK homomixer rotation speed in the emulsification process was changed, the toner particle size was changed in various ways, the toner was prepared, shape control and solvent removal were performed [dispersed slurry 2 ~ 7].
Using [Dispersion Slurries 1 to 7], toners were prepared by variously changing the filtration method in the washing step. Drying and external mixing conditions were the same as in Example 1.

[Example 2]
[Dispersion Slurry 2] 100 parts were filtered out with a filter press assembled with a filter cloth having a filter aeration rate of 10 cc / cm ² · min, a material of polypropylene and a thickness of 0.9 mm, and a pressing pressure of 0.4 MPa. It dehydrated and [filter cake 2] was obtained.

[Example 3]
[Dispersion slurry 3] 100 parts were filtered out with a filter press assembled with a filter cloth having a filter air flow rate of 10 cc / cm ² · min, a material of polypropylene and a thickness of 0.9 mm, and a pressing pressure of 0.4 MPa. It dehydrated and [filter cake 3] was obtained.

[Example 4]
[Dispersion slurry 4] 100 parts were filtered out with a filter press assembled with a filter cloth having a filter air flow rate of 30 cc / cm ² · min, a material of polypropylene, and a thickness of 0.7 mm. It dehydrated and [filter cake 4] was obtained.

[Example 5]
[Dispersion Slurry 1] 100 parts were filtered out with a filter press assembled with a filter cloth having a filter air flow rate of 50 cc / cm ² · min, a material of cotton, and a thickness of 1.2 mm. It dehydrated and [filter cake 5] was obtained.

[Example 6]
[Dispersion Slurry 1] 100 parts were filtered off with a filter press assembled with a filter cloth having a filter air permeability of 10 cc / cm ² · min, a wool material and a thickness of 2.0 mm, and the pressing pressure was 0.4 MPa. It dehydrated and [filter cake 6] was obtained.

[Example 7]
[Dispersion Slurry 1] 100 parts were filtered out with a vacuum belt filter assembled with a filter cloth having a filter air permeability of 50 cc / cm ² · min, a material of polypropylene and a thickness of 0.7 mm, and [Filter cake 7] Got.

[Example 8]
[Dispersion Slurry 1] 100 parts are filtered with a centrifugal effect of 1000G using a siphon pillar type centrifuge with a filter cloth with a filter air flow rate of 50 cc / cm ² · min, a material of polypropylene and a thickness of 0.7 mm. [Filtered cake 8] was obtained.

[Example 9]
[Dispersion Slurry 1] 100 parts were filtered out with a filter press assembled with a filter cloth having a filter air flow rate of 50 cc / cm ² · min, a material of polypropylene, and a thickness of 0.7 mm. It dehydrated and [filter cake 9] was obtained.
[Filter cake 9] Add 100 parts of ion-exchanged water to 100 parts, uniformly disperse with a TK homomixer (30 minutes at 6,000 rpm), add 0.001 part of a water-soluble charge control agent, Charge control agent-dispersed slurry 1] was obtained.
100 parts of [Charge Control Agent Dispersed Slurry 1] were filtered with a siphon pillar type centrefuge with a centrifugal effect of 1000 G to obtain [Filter Cake 10].

[Example 10]
[Dispersion Slurry 1] 100 parts were filtered out with a filter press assembled with a filter cloth having a filter air flow rate of 50 cc / cm ² · min, a material of polypropylene, and a thickness of 0.7 mm. It dehydrated and washed with 100 parts of ion-exchanged water from the filter side to obtain [Filter cake 11].
[Filter cake 11] Add 100 parts of ion-exchanged water to 100 parts, uniformly disperse with a TK homomixer (30 minutes at 6,000 rpm), add 0.001 part of a water-soluble charge control agent, Charge control agent-dispersed slurry 2] was obtained.
100 parts of [Charge Control Agent Dispersion Slurry 2] were filtered with a siphon pillar type centrefuge with a centrifugal effect of 1000G to obtain [Filter Cake 12].

[Example 11]
[Dispersion Slurry 5] 100 parts were filtered out with a filter press assembled with a filter cloth having a filter aeration rate of 60 cc / cm ² · min, a material of polypropylene and a thickness of 1.3 mm, and a pressing pressure of 0.4 MPa. It dehydrated and [filter cake 13] was obtained.

[Example 12]
[Dispersion Slurry 6] 100 parts were filtered off with a filter press assembled with a filter cloth having a filter air flow rate of 7 cc / cm ² · min, a material of polypropylene and a thickness of 1.0 mm, and a pressing pressure of 0.4 MPa. Dehydration gave [filter cake 14].

[Comparative Example 1]
[Dispersion Slurry 1] 100 parts of a filter having an air flow rate of 100 cc / cm ² · min,
The material was separated by a filter press with a filter cloth having a material of polypropylene and a thickness of 0.5 mm, and dehydrated at a pressing pressure of 0.4 MPa to obtain [Filter Cake 15].

[Comparative Example 2]
[Dispersion Slurry 1] 100 parts were filtered out with a filter press assembled with a filter cloth having a filter air flow rate of ² cc / cm ² · min, a material of polypropylene, and a thickness of 1.1 mm. It dehydrated and [filter cake 16] was obtained.

[Comparative Example 3]
[Dispersion Slurry 7] 100 parts were filtered out with a filter press assembled with a filter cloth having a filter air flow rate of 80 cc / cm ² · min, a material of cotton, and a thickness of 1.5 mm, and the pressing pressure was 0.4 MPa. It dehydrated and [filter cake 17] was obtained.

[Comparative Example 4]
[Dispersion Slurry 8] 100 parts were filtered off with a filter press assembled with a filter cloth having a filter air permeability of 10 cc / cm ² · min, a material of polypropylene and a thickness of 0.9 mm, and a pressing pressure of 0.4 MPa. It dehydrated and [filter cake 18] was obtained.

[Comparative Example 5]
[Dispersion Slurry 9] 100 parts were filtered out with a filter press assembled with a filter cloth having a filter air permeability of 10 cc / cm ² · min, a material of polypropylene, and a thickness of 0.9 mm. It dehydrated and [filter cake 19] was obtained.

  On the other hand, the carrier used in this example and the comparative example is obtained by dissolving and dispersing 200 parts of a silicone resin solution (manufactured by Shin-Etsu Chemical Co., Ltd.) and 3 parts of carbon black (manufactured by Cabot) in 2500 parts of ferrite core material. The coated liquid was applied by a fluidized bed spray method to coat the surface of the core material, and then baked in an electric furnace at 300 ° C. for 2 hours to obtain a silicon resin coated carrier. As for the carrier particle size, it is preferable to use a carrier having a relatively sharp particle size distribution and an average particle size of 30 to 60 μm, and this was also used in this example.

[Image forming apparatus]
The form of the image forming apparatus used in Examples and Comparative Examples will be described.
A charging roller for charging a uniform charge on the photosensitive drum in proximity to or in contact with the periphery of the photosensitive drum as an image carrier, and exposure for forming an electrostatic latent image on the photosensitive drum. An exposure device as a means, a developing device that visualizes an electrostatic latent image into a toner image, a transfer belt that transfers the toner image onto a transfer paper, a cleaning device that removes residual toner on the photosensitive drum, and a photosensitive member A neutralizing lamp that neutralizes the residual charge on the drum, a photosensor for controlling the charging roller applied voltage and the developing toner density are arranged. In addition, the toner of the embodiment or the comparative example is supplied to the developing device from the toner supply device through the toner supply port. The image forming operation is performed as follows. The photosensitive drum rotates counterclockwise. The photosensitive drum is neutralized by neutralizing light, and the surface potential is averaged to a reference potential of 0 to -150V. Next, it is charged by the charging roller,
The surface potential is around -1000V. Next, the surface potential of the portion (image portion) that is exposed by the exposure apparatus and irradiated with light is 0 to −200V. The toner on the sleeve adheres to the image portion by the developing device. The photosensitive drum on which the toner image is formed rotates and moves, and the transfer paper is fed from the paper supply unit at a timing such that the front end of the image coincides with the front end of the image on the transfer belt. The image is transferred to transfer paper. Thereafter, the transfer sheet is sent to the fixing unit, and the toner is fused to the transfer sheet by heat and pressure and discharged as a copy. Residual toner remaining on the photosensitive drum is scraped off by a cleaning blade in the cleaning device, and thereafter, the residual charge is neutralized by the neutralizing light to be in an initial state without toner, and again to the next image forming process. Move.

The operation conditions of Examples 1 to 12 and Comparative Examples 1 to 5 are shown in [Table 1] below, and the toners prepared in Examples 1 to 12 and Comparative Examples 1 to 5 are evaluated as follows. Is shown in the following [Table 2].
[Measurement of air flow]
The air permeability before and after use of the filter cloth used in each example and comparative example was measured based on the fragile method defined in JIS L 1096. Six measurement points were selected at random and measured.

[Measurement of toner leakage]
In each Example and Comparative Example, the filtrate after filtration was collected and dried, and the amount of toner leaked to the filtrate side was measured from the weight change before and after drying.
[Evaluation item]
In the image forming apparatus, the following items were evaluated using the toners and developers of Examples and Comparative Examples.
1) Charging characteristics The charging characteristics are as follows: the toner and the carrier are frictionally charged in an environment of temperature / humidity = 23 ° C./55% RH to obtain a developer, and [Charge 1] is measured. = 30 ° C./90% RH in a test room for 2 days, [Charge amount 2] was measured, and the variation rate of Q / M from [Charge amount 1] to [Charge amount 2] was examined.
Q / M variation rate (%) = ([charge amount 1] − [charge amount 2]) / [charge amount 1] × 100
A Q / M fluctuation rate of 0 to less than 15% was evaluated as ◯, a value of 15 to less than 30% was evaluated as Δ, and 30% or more was evaluated as ×.

2) Cleaning performance Cleaning performance is as follows. In a test room where temperature / humidity = 10 ° C./15%, 10000 sheets are passed through a Ricoh image forming apparatus, and then a blank image is stopped while passing through the sheet. The transfer residual toner on the photosensitive member that has passed through the process is transferred to white paper with a scotch tape (manufactured by Sumitomo 3M Co., Ltd.), measured with a Macbeth reflection densitometer RD514, and cleaned with a difference of less than 0.010 from the blank. Quantitative evaluation was made by ◯ indicating that the property was good, 0.010 to 0.02 and not being good cleaning property but Δ being acceptable, and × being exceeding 0.02 and poor cleaning property.

3) Image quality Image quality was comprehensively determined as deterioration in image quality (specifically, transfer failure, background image generation) of the image after passing paper. The transfer failure was judged by passing 5000 sheets through a Ricoh image forming apparatus and then passing a black solid image and visually ranking the transfer failure level of the image. As for the background stain image, 5000 sheets are passed through the Ricoh image forming apparatus, and then the blank image is stopped during development, and the developer on the developed photosensitive member is transferred to tape and untransferred. The difference between the image density of the tape and the image density was measured with a spectrodensitometer (manufactured by X-Rite), and quantitative evaluation was made. . These two were evaluated as good when the image quality was good, ◯ when the image quality was not good but acceptable, and x when the image quality was poor.

(Explanation of results)
In Examples 1 to 12, the filters used according to the Dv and Dv / Dn of the toner have a small rate of decrease in air permeability after repeated use 100 times and a small amount of toner leakage to the filtrate side. Further, the quality of the obtained toner was good.
In Comparative Examples 1 and 3, since T / Dv> 10, the amount of toner leakage to the filtrate side is large, and a burden is imposed on the waste water treatment, resulting in poor yield.
In Comparative Examples 2, 4, and 5, since T / (Dv / Dn) ¹⁰ <1, the filter was completely clogged, and almost no filtration was possible from the middle.
The quality of the toners obtained in Comparative Examples 1 to 4 was not satisfactory. In Comparative Example 5, since the moisture content of the cake was too high, there were many aggregates after drying, and the toner could not be evaluated.

Claims (13)

In a method for producing a toner for developing an electrostatic image comprising a step of solid-liquid separation through a synthetic resin filter from toner particles containing at least a binder resin and a colorant dispersed in a liquid medium, The toner particle size is
T / Dv <10
and,
T / (Dv / Dn) ¹⁰ > 1
[T is the air flow rate (cc / cm ² · min),
Dv is the volume average particle diameter (μm) of the toner particles,
Dv / Dn represents the ratio of the volume average particle diameter (Dv) to the number average particle diameter (Dn)]
A method for producing a toner for developing an electrostatic image, characterized by satisfying the relationship:   The binder resin is composed of a modified polyester resin capable of reacting with active hydrogen in an organic solvent, a toner composition containing the binder resin is dissolved or dispersed, and the dissolved or dispersed solution is an aqueous medium containing resin fine particles. A method for producing a toner which is dispersed in the mixture and then reacted with a compound having an active hydrogen group, and the toner particles are solid-liquid separated from the resulting dispersion and dried. 2. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the relationship between the air flow rate and the toner particle size is satisfied.   The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the synthetic resin filter used in the solid-liquid separation step has a thickness of 0.5 to 1.5 mm.   The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein a material of the synthetic resin filter used in the solid-liquid separation step is polypropylene.   The method for producing a toner for developing an electrostatic charge image according to any one of claims 1 to 4, wherein the device used in the solid-liquid separation step is a filter press (pressure filtration method).   The method for producing a toner for developing an electrostatic charge image according to any one of claims 1 to 4, wherein the device used in the solid-liquid separation step is a centrifugal filter (centrifugal filtration method).   The method for producing a toner for developing an electrostatic charge image according to any one of claims 1 to 4, wherein the device used in the solid-liquid separation step is a vacuum belt filter (vacuum filtration method).   The toner for developing an electrostatic charge image according to claim 1, wherein the toner particles have a volume average particle diameter Dv of 3 to 8 μm.   9. The electrostatic charge image developing toner according to claim 1, wherein the Dv / Dn is 1.40 or less.   6. The method for producing a toner for electrostatic charge development according to claim 5, wherein after the solid-liquid separation with the filter press, the mixture is compressed and washed from the filter side.   The method for producing a toner for electrostatic charge development according to claim 10, wherein the moisture content of the cake after the solid-liquid separation is 35 to 45% by weight.   The method for producing a toner for electrostatic charge development according to claim 11, wherein a charge control agent is added after the cake is dispersed in water.   The method for producing a toner for electrostatic charge development according to claim 6, wherein the dispersion is subjected to solid-liquid separation with a centrifugal filter, and the moisture content of the cake after dehydration is 20 to 35% by weight.