JP6163928B2 - Method for producing polyester resin for toner - Google Patents

Description

  The present invention relates to a method for producing a polyester resin for toner.

  In the method of obtaining an image by the electrophotographic printing method and the electrostatic charge developing method, the electrostatic charge image formed on the photoreceptor is developed with toner charged in advance by friction and then fixed. In order to pass through these processes without any problem, the toner needs to maintain a stable charge amount first, and then needs to have good fixability to paper. In addition, the apparatus has a fixing unit which is a heating body, and the temperature in the apparatus rises, so that it is necessary that the toner does not block.

  Further, even during continuous printing, it is necessary that the apparatus is not soiled or fogged on the printing surface, that is, the toner has hot offset resistance.

  The binder resin for toner has a great influence on the toner performance as described above, and a polyester resin having a good balance of performance is used.

  Examples of the method for producing a toner using a polyester resin include a pulverization method and a chemical method. The pulverization method is a method of obtaining a toner by melt-kneading a polyester resin, a pigment (colorant), a release agent, and the like, pulverizing and classifying the obtained kneaded material. In recent years, in order to achieve high image quality, it is desired to reduce the particle size of toner, and a chemical method that can efficiently reduce the particle size has attracted attention.

  As a chemical method, for example, a binder resin, a colorant, a release agent, etc. are dissolved in a solvent to obtain an oil phase, the oil phase is suspended as oil droplets in an aqueous medium, and then the solvent is removed. To get toner. There is a method of obtaining a toner by aggregating resin fine particles obtained by emulsion polymerization, a colorant, a release agent, and the like in an aqueous medium and fusing them by heating.

  For example, Patent Document 1 describes a method of obtaining toner particles by a chemical method using a sulfonated polyester resin.

  Patent Document 2 describes a polyester having a sulfobenzenedicarboxylic acid unit and having excellent water dispersibility.

JP 2007-102224 A Japanese Patent Laid-Open No. 9-22136

  However, the polyester resin described in Patent Document 1 has insufficient water dispersibility and hot offset resistance. In addition, the polyester resin described in Patent Document 2 has insufficient hot offset resistance.

  An object of the present invention is to solve this problem and to provide a polyester resin for a toner excellent in water dispersibility, hot offset resistance and storage stability.

  The gist of the present invention is that at least one selected from trivalent or higher polyvalent carboxylic acids and trihydric or higher polyhydric alcohols, bis (2-hydroxyethyl) sodium salt of sulfoisophthalate, and a bisphenol A alkylene oxide adduct. The present invention resides in a method for producing a polyester resin for a toner, in which a monomer mixture is polycondensed using a titanium-based catalyst.

  By the production method of the present invention, a polyester resin for toner excellent in water dispersibility, hot offset resistance and storage stability can be produced.

  In the present invention, at least one selected from a trivalent or higher polyvalent carboxylic acid and a trivalent or higher polyhydric alcohol, a bis (2-hydroxyethyl) sodium salt of sulfoisophthalic acid, and a bisphenol A alkylene oxide adduct The monomer mixture is polycondensed using a titanium-based catalyst.

  In the present invention, it is necessary that the monomer mixture contains at least one selected from trivalent or higher polyvalent carboxylic acids and trivalent or higher polyhydric alcohols.

By containing a trivalent or higher polyvalent carboxylic acid or a trivalent or higher polyhydric alcohol,
A crosslinked structure is formed in the resin, and the hot offset resistance is improved.

  Examples of the trivalent or higher polyvalent carboxylic acid include trimellitic acid, pyromellitic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid. 1,2,5-hexanetricarboxylic acid, 1,2,7,8-octanetetracarboxylic acid or acid anhydrides or lower alkyl esters thereof.

  Examples of the trihydric or higher polyhydric alcohol include sorbitol, 1,2,3,6-hexatetralol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4. -Butanetriol, 1,2,5-pentanetriol, glycerol, 2-methyl-1,2,3-propanetriol, 2-methyl-1,2,4-butanetriol, trimethylolpropane, 1,3,5 -Trihydroxymethylbenzene etc. are mentioned.

  Among these, trimellitic acid or its acid anhydride, pentaerythritol, and trimethylolpropane are preferable. These trivalent or higher polyvalent carboxylic acids and trivalent or higher polyhydric alcohols may be used alone or in combination.

  In this invention, it is preferable to contain 1-25 mol part of polyvalent carboxylic acid more than trivalence or polyhydric alcohol more than trivalence with respect to 100 mol part of polyhydric carboxylic acid components. If it is less than 1 mole part, the cross-linked structure is small in the resin and the durability is low. On the other hand, when it exceeds 25 parts by mole, the viscosity tends to increase during the polymerization (gelation), and the polymerization stability tends to decrease.

  In the present invention, it is necessary that the monomer mixture contains bis (2-hydroxyethyl) sodium salt of sulfoisophthalic acid. In the present invention, water dispersibility is improved by bis (2-hydroxyethyl) sodium salt of sulfoisophthalic acid.

  Examples of sodium bis (2-hydroxyethyl) sulfoisophthalate include 2-sulfoisophthalic acid sodium bis (2-hydroxyethyl) ester, 4-sulfoisophthalic acid sodium bis (2-hydroxyethyl) ester, and 5-sulfoisophthalic acid. Examples thereof include sodium bis (2-hydroxyethyl) ester and sodium 6-sulfoisophthalate bis (2-hydroxyethyl) ester. From the viewpoint of availability of raw materials and polymerization stability, sodium 5-sulfoisophthalate bis (2-hydroxyethyl) ester is preferred.

  The bis (2-hydroxyethyl) sodium salt of sulfoisophthalic acid is preferably contained in an amount of 3 to 12 mol parts per 100 mol parts of the polyvalent carboxylic acid component. If the sodium salt of sulfoisophthalate bis (2-hydroxyethyl) is less than 3 parts by mole, water dispersibility tends to be insufficient because there are few sulfonic acid sodium salt sites that can be ionized in water. Hot offset tends to be insufficient.

  Furthermore, in this invention, preservability improves by including the bisphenol A alkylene oxide adduct in the said monomer mixture. Examples of the bisphenol A alkylene oxide adduct include polyoxyethylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.0) -2,2-bis ( 4-hydroxyphenyl) propane, polyoxypropylene- (2.3) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.2) -polyoxyethylene- (2.0) -2 , 2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.2) -2,2-bis (4-hydroxy) Phenyl) propane, polyoxypropylene- (2.4) -2,2-bis (4-hydroxyphenyl) propane, polyoxyp Pyrene (3.3) -2,2-bis (4-hydroxyphenyl) bisphenol A alkylene oxide adducts such as propane. In particular, polyoxypropylene- (2.3) -2,2-bis (4-hydroxyphenyl) propane is preferable from the viewpoint of reducing the viscosity of the slurry at room temperature.

  The bisphenol A alkylene oxide adduct is preferably contained in an amount of 5 to 90 mol parts per 100 mol parts of the polyvalent carboxylic acid component. When the amount is less than 5 parts by mole, the storage stability tends to decrease, and when it exceeds 90 parts by mole, the polymerization stability tends to decrease.

  In the present invention, examples of the components contained in the monomer mixture include the following in addition to the components described above.

  Examples of the polyvalent carboxylic acid component include terephthalic acid, isophthalic acid or lower alkyl esters thereof, phthalic acid, sebacic acid, isodecyl succinic acid, dodecenyl succinic acid, maleic acid, fumaric acid, adipic acid, or monomethyl, monoethyl thereof, Ingredients from dimethyl, diethyl esters or their anhydrides. Examples of lower alkyl esters of terephthalic acid and isophthalic acid include dimethyl terephthalate, dimethyl isophthalate, diethyl terephthalate, diethyl isophthalate, dibutyl terephthalate, and dibutyl isophthalate. In this respect, terephthalic acid and isophthalic acid are preferable. An aliphatic dicarboxylic acid component can also be used as appropriate.

  Polyhydric alcohol components include ethylene glycol, neopentyl glycol, propylene glycol, butanediol, polyethylene glycol, 1,2-propanediol, 1,4-butanediol, diethylene glycol, triethylene glycol, 1,4-cyclohexane. A dimethanol etc. can be mentioned, These can be used individually or in combination of 2 or more types. In particular, ethylene glycol, 1,2-propanediol, and 1,4-cyclohexanedimethanol are preferable, and ethylene glycol and 1,2-propanediol are particularly preferable from the viewpoint of easily designing polymerization reactivity and Tg of the resin to 40 ° C. or higher. preferable.

  In addition, these can be used individually or in combination of 2 or more types, respectively.

  Furthermore, a monovalent carboxylic acid or a monovalent alcohol can also be used for the purpose of adjusting the number of terminal functional groups and improving the dispersibility of other toner materials within a range not impairing the object of the present invention. Examples of monovalent carboxylic acids include aromatic carboxylic acids having 30 or less carbon atoms such as benzoic acid and p-methylbenzoic acid, aliphatic carboxylic acids having 30 or less carbon atoms such as stearic acid and behenic acid, and cinnamic acid. And unsaturated carboxylic acids having one or more unsaturated double bonds in the molecule, such as oleic acid, linoleic acid, and linolenic acid.

  Examples of monohydric alcohols include aromatic alcohols having 30 or less carbon atoms such as benzyl alcohol, and aliphatic alcohols having 30 or less carbon atoms such as oleyl alcohol, lauryl alcohol, cetyl alcohol, stearyl alcohol, and behenyl alcohol. .

  Moreover, in this invention, you may add a mold release agent component with said component in the range which does not impair the effect of this invention as needed to the said monomer mixture. By adding a release agent component and polymerizing, the toner fixing property and wax dispersibility tend to be improved. Furthermore, a stabilizer may be added to the monomer mixture for the purpose of obtaining polymerization stability of the polyester resin. Examples of the stabilizer include hydroquinone, methyl hydroquinone, hindered phenol compounds and the like.

  In the present invention, the monomer mixture is polycondensed using a titanium-based catalyst. Titanium-based catalyst has high reaction activity, especially esterification reaction time is shorter than non-catalytic system and other catalyst systems, improves resin productivity, and can reduce the amount of resin oligomer, so the particle size after water dispersion becomes uniform, Water dispersibility is improved. Non-titanium catalysts such as tin and antimony are generally heterogeneous catalysts that are dispersed in the raw material. When water dispersion treatment is performed, particles are likely to aggregate using this as a core, resulting in poor water dispersibility. To do.

  Examples of the titanium-based catalyst include at least one titanium compound comprising a titanium alkoxide compound having an alkoxy group, titanium carboxylate, titanyl carboxylate, titanyl carboxylate, and titanium chelate compound.

  Examples of the titanium alkoxide compound having an alkoxy group include tetramethoxy titanium, tetraethoxy titanium, tetrapropoxy titanium, tetrabutoxy titanium, tetrapentoxy titanium, tetraoctoxy titanium and the like.

  Titanium carboxylate compounds include titanium formate, titanium acetate, titanium propionate, titanium octoate, titanium oxalate, titanium succinate, titanium maleate, titanium adipate, titanium sebacate, titanium hexanetricarboxylate, titanium isooctanetricarboxylate , Titanium octane tetracarboxylate, titanium decane tetracarboxylate, titanium benzoate, titanium phthalate, titanium terephthalate, titanium isophthalate, titanium 1,3-naphthalenedicarboxylate, titanium 4,4-biphenyldicarboxylate, 2,5 -Titanium dicarboxylate, anthracene dicarboxylate, trimellitic acid titanium, 2,4,6-naphthalene tricarboxylic acid titanium, pyromellitic acid titanium, 2,3,4,6-naphthalene tetracarboxylic acid titanium, etc. It is.

  Examples of the titanyl carboxylate compound include titanyl benzoate, titanyl phthalate, titanyl terephthalate, titanyl isophthalate, titanyl 1,3-naphthalenedicarboxylate, titanyl 4,4-biphenyldicarboxylate, titanyl 2,5-toluenedicarboxylate, Anthracene dicarboxylic acid titanyl, trimellitic acid titanyl, 2,4,6-naphthalene tricarboxylic acid titanyl, pyromellitic acid titanyl, 2,3,4,6-naphthalene tetracarboxylic acid titanyl, etc. are mentioned.

  The titanyl carboxylate compound is not particularly limited, and examples thereof include alkali metal (lithium, sodium, potassium, etc.) or alkaline earth metal (magnesium, calcium, barium, etc.) salts for the above-mentioned titanyl carboxylate. .

  When a titanium chelate compound is used, the ligand is preferably selected from acetylacetone, ethyl acetoacetate, octylene glycol, triethanolamine, lactic acid, and ammonium lactate.

  The amount of the titanium-based catalyst is preferably 50 ppm or more with respect to the polyvalent carboxylic acid from the viewpoint of polycondensation reactivity. Moreover, 1500 ppm or less is preferable from the point which prevents coloring of the polyester resin obtained.

  The polycondensation of the monomer mixture can be performed under known conditions.

  The polycondensation temperature is preferably in the range of 180 ° C to 280 ° C. When the polymerization temperature is 180 ° C. or higher, the productivity tends to be good, and when it is 280 ° C. or lower, the decomposition of the resin and the by-product of volatile components that cause odor tend to be suppressed. The lower limit of the polymerization temperature is more preferably 200 ° C. or higher, and the upper limit is more preferably 270 ° C. or lower.

  The end point of the polycondensation may be carried out until the stirring torque reaches a value indicating a desired softening temperature. Ending the polycondensation means that the stirring of the reaction apparatus is stopped, the inside of the apparatus is brought to normal pressure, the inside of the apparatus is pressurized with nitrogen, the reaction product is taken out from the lower part of the apparatus, and cooled to 100 ° C. or lower. .

  The glass transition temperature (Tg) of the polyester resin for toner obtained by the production method of the present invention is preferably 40 ° C. or higher and lower than 75 ° C. 45 ° C. or higher is preferable from the viewpoint of the storage stability of the toner, and 73 ° C. or lower is preferable from the viewpoint of low-temperature fixability. Especially preferably, it is 48-65 degreeC.

  The softening temperature of the polyester resin of the present invention is preferably 90 to 160 ° C. If the softening temperature is less than 90 ° C., the durability as a resin for toner is insufficient, and if it exceeds 160 ° C., the low-temperature fluidity is insufficient.

  Furthermore, the acid value of the polyester resin of the present invention is preferably 1 to 50 mgKOH / g. If the acid value is 1 mgKOH / g or more, the chargeability is good, and if it is 50 mgKOH / g or less, moisture absorption can be suppressed. Preferably it is 1-40 mgKOH / g, Most preferably, it is 1-30 mgKOH / g.

  The number average molecular weight measured by gel permeation chromatography (GPC) of the polyester resin of the present invention is preferably 1,000 to 30, more preferably 1,000 to 30,000, from the viewpoints of durability and fixability. More preferably, it is 1,000 to 10,000.

  The polyester resin of the present invention may exhibit crystallinity. The crystallinity of the resin is defined as having a melting point peak in a measurement based on JIS K7121 using a differential scanning calorimeter (DSC) with a single resin. The melting peak temperature is, for example, preferably from 50 ° C. to 100 ° C., and more preferably from 60 ° C. to 90 ° C.

  The toner containing the polyester resin for toner of the present invention can be produced by a known pulverization method or chemical method. For example, a polyester resin and a compound of chemical method are dispersed in an aqueous medium, and after forming aggregated particles in the aqueous medium, the solvent is removed, washed and dried to obtain toner particles. It can be produced by externally adding inorganic particles.

  In the step of preparing the resin particle dispersion in which the polyester resin particles are dispersed, the aqueous medium and the present resin are charged so as to have a desired solid content, and heated to Tg of the resin or more to prepare the resin particle dispersion. Examples of the aqueous medium include water such as distilled water and ion exchange water. As an additive to be added to the aqueous dispersion, an inorganic salt or an alcohol having about 6 to 16 carbon atoms may be added as long as the performance of the toner is not impaired.

  In order to adjust the particle size in the resin particle dispersion, for example, a general dispersion method such as a rotary shear homogenizer, a ball mill having media, a sand mill, or a dyno mill can be used.

  Examples of the volume average particle size of the polyester resin particles dispersed in the resin particle dispersion include a range of 0.01 μm or more and less than 2 μm. If it is less than 0.01 μm, the amount of the aggregating agent tends to increase in the step of forming aggregated particles, and if it is 2 μm or more, the number of particles until the desired toner particle size is small, and uniform material mixing becomes difficult. In addition, the volume average particle diameter of the polyester resin particles can be measured with a laser diffraction particle size distribution measuring apparatus (LA-920, manufactured by Horiba, Ltd.).

  As content (solid content) of the polyester resin particle contained in the said resin particle dispersion liquid, 5 to 50 mass% is preferable, and 10 to 40 mass% is more preferable. If it exceeds 50% by mass, the dispersion tends to thicken, and the operability is remarkably reduced. If it is less than 5% by mass, it is difficult to form particles in the aggregation step.

  Similarly to the resin particle dispersion, for example, a colorant dispersion and a release agent dispersion are also prepared. The aqueous medium used when preparing the colorant dispersion and the release agent dispersion is mainly composed of water. From the viewpoint of environmental conservation, the water content is preferably 80% by weight or more in the aqueous medium. . Examples of components other than water include organic solvents miscible with water, such as methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran.

Further, when adjusting the colorant dispersion or the release agent dispersion, a neutralization treatment or a surfactant may be added as necessary to stabilize the dispersion state of the particles.
The basic compound used in the neutralization treatment may be either an inorganic basic compound or an organic basic compound. Examples of the inorganic basic compound include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, weak acid salts such as carbonates and acetates thereof, partially neutralized salts, and ammonia. . Examples of the organic basic compound include alkylamines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine and triethylamine, alkanolamines such as diethanolamine, and fatty acid salts such as sodium succinate and sodium stearate. These basic compounds may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the surfactant include anionic surfactants such as sodium dodecylbenzenesulfonate and sodium octadecyl sulfate; cationic surfactants such as laurylamine acetate and lauryltrimethylammonium chloride; amphoteric surfactants such as lauryldimethylamine oxide; Nonionic surfactants, such as polyoxyethylene alkyl ether, are mentioned. Among these, anionic surfactants and nonionic surfactants are preferable from the viewpoint of emulsion stability and the like, and anionic surfactants are more preferable. These surfactants may be used individually by 1 type, and may be used in combination of 2 or more type.

  In the step of forming aggregated particles, the colorant particle dispersion and the release agent dispersion are mixed together with the resin particle dispersion. In a mixed dispersion, polyester resin particles, colorant particles, and release agent particles are heteroaggregated to form aggregated particles containing resin / colorant / release agent having a diameter close to the diameter of the target toner particles. Form. For example, the flocculant is added to the mixed dispersion, the pH of the mixed dispersion is adjusted to about 2 or more and 5 or less of the acidic condition, and the dispersion stabilizer is added as necessary, from the glass transition temperature of the resin particles. The mixture is heated to about 80 ° C., and the particles dispersed in the mixed dispersion are aggregated to form aggregated particles. In addition, the mixed dispersion is stirred with a rotary shearing homogenizer and a flocculant is added at room temperature of about 25 ° C., and the pH of the mixed dispersion is adjusted to about 2 to 5 under acidic conditions, and dispersed as necessary. After adding the stabilizer, the heat treatment may be performed to form aggregated particles.

  As an example of the flocculant, those showing a salting-out effect are preferable, and surfactants or inorganic metal salts having a polarity opposite to that of the surfactant used as the dispersant added to the mixed dispersion liquid, divalent or higher metal complexes, and the like Is mentioned. Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate. A water-soluble chelating agent may be used. Examples of chelating agents include tartaric acid, citric acid, and ethylenediaminetetraacetic acid (EDTA). Examples of the addition amount of the chelating agent include a range of 0.01 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the resin particles, and 0.1 parts by mass or more and less than 3.0 parts by mass. There may be.

  The amount of the flocculant used is preferably 20 parts by weight or less, preferably 0.01 to 15 parts by weight with respect to 100 parts by weight of the resin / colorant / release agent, from the viewpoint of aggregation ability and toner storage stability. More preferred is 0.01 to 10 parts by weight. The flocculant is preferably added while being dissolved in an aqueous medium while stirring, and it is preferable to sufficiently stir at the time of adding the flocculant and after the addition is completed.

  Next, the aggregated particle dispersion in which the aggregated particles are dispersed is heated from the glass transition temperature of the polyester resin to about 80 ° C. to fuse and coalesce the aggregated particles to form toner particles. The toner particles formed in the solution are dried through a known washing step, solid-liquid separation step, and drying step to obtain toner particles.

  In the washing step, it is preferable to sufficiently perform substitution washing with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration and the like are preferable from the viewpoint of productivity. Furthermore, freeze drying, flash jet drying, fluidized drying, vibration fluidized drying, etc. are used for a drying process from a point of productivity.

  Finally, an additive is added to the dried toner particles obtained and mixed. Mixing is performed by, for example, a blender or a Henshur mixer. Further, if necessary, the toner having a desired particle size distribution is obtained by removing coarse particles of the toner using a vibration classifier or the like.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. Moreover, evaluation was performed by the following method.

<Glass transition temperature (Tg)>
Using a differential differential calorimeter (DSC-60, manufactured by Shimadzu Corporation), measurement was performed from the intersection of the base line of the chart and the tangent line of the endothermic curve at a heating rate of 5 ° C./min. A sample to be measured was weighed 10 mg ± 0.5 mg, placed in an aluminum pan, melted at 100 ° C. above the glass transition temperature for 10 minutes, and then rapidly cooled using dry ice.

<Softening temperature (T4)>
Using a flow tester (CFT-500D manufactured by Shimadzu Corporation), 1 mmφ × 10 mm nozzle, load 294 N, and heating rate 3 ° C./min. The temperature when flowing out of the nozzle was measured.

<Acid value (AV)>
0.2 g of the sample was precisely weighed in a branch Erlenmeyer flask (A (g)), 10 ml of benzyl alcohol was added, and the resin was dissolved by heating with a heater at 230 ° C. for 15 minutes in a nitrogen atmosphere. After cooling to room temperature, 10 ml of benzyl alcohol, 20 ml of chloroform and a few drops of a phenolphthalein solution were added, and titrated with a 0.02 N KOH solution (titrate = B (ml), titer of KOH solution = p). A blank measurement was performed in the same manner (titer amount = C (ml)), and calculation was performed according to the following formula.
Acid value (mgKOH / g) = (BC) × 0.02 × 56.11 × p ÷ A
<Polymerization stability>
The polymerization stability was determined based on the following criteria for the presence or absence of a phase immiscible with water when water distilled during the esterification reaction (ES reaction) was measured with a graduated cylinder.
○ (Good): A phase immiscible with water is not visually confirmed.
Δ (usable): The phase immiscible with water is 0.5 ml or more and less than 3 ml by visual measurement (graduated cylinder)
X (Inferior): The phase immiscible with water is 3 ml or more by visual measurement (measuring cylinder).

<Water dispersibility>
The water dispersibility was judged from the volume median particle diameter of the resin dispersion obtained by the following operation and the number of peaks. First, 2 g of resin is precisely weighed in a standard bottle with a lid, and 8 g of distilled water is added. A standard bottle containing resin and distilled water is shaken by inverting the standard bottle every hour under a constant temperature condition of 80 ° C. When shaking and mixing, if coarse particles are no longer visible on the bottom of the bottle, use an ultrasonic device (UT-206H, manufactured by Sharp Corporation) to disperse at 50 ° C, 100% output for 10 minutes. I do.

The particle size and particle size distribution of the obtained water-dispersed polyester resin are measured using a laser diffraction type particle size measuring device (trade name: “LA-920” manufactured by Horiba, Ltd.). In accordance with the operation manual of the apparatus, distilled water is added into the cell using a measurement flow cell, the relative refractive index is selected and set to 1.20, the particle size standard is the volume standard, the optical axis is adjusted, and the optical axis is adjusted. Perform fine adjustment and blank measurement. Next, the polyester aqueous dispersion is added to a concentration in the range of 70 to 90% transmittance, and ultrasonic treatment is performed for 1 minute at an intensity of 5 to measure the particle size distribution of the resin particles. The volume median particle diameter is a particle diameter (median diameter) corresponding to a cumulative 50% based on the volume distribution.
○ (Good): The volume-median particle size is less than 1 μm, and only one particle size distribution peak is confirmed in the range of 0.02 to 2000 μm.
X (Inferior): The volume-median particle size is 1 μm or more, or two or more peaks are observed in the particle size distribution range of 0.02 to 2000 μm.

<Preservability>
The storability was evaluated by determining the adsorption moisture content of the resin. 10.00 g of the resin was precisely weighed and pulverized with a trioblender pulverizer (manufactured by Trio Science), and 5 g of resin particles of 250 μm to 500 μm were precisely weighed in an aluminum dish. This was installed in a constant temperature and humidity device (J50 manufactured by Satake Rika Refrigerating Co., Ltd.) under conditions of 35% and 85% relative humidity. From the weight change before and after the treatment for 120 hours under the above conditions, the amount of adsorbed water was determined, and the storage stability was evaluated as the adsorbed water content relative to the resin weight (5 g) before the treatment.
The storage stability was evaluated as follows from the obtained moisture content.
◎ (Very good): Adsorption moisture ratio of less than 1% ○ (Good): Adsorption moisture ratio of 1% to less than 2% △ (available): Adsorption moisture ratio of 2% to less than 3% x (Inferior): Adsorption moisture content of 3% or more <Hot offset resistance>
Hot offset resistance was evaluated using a rotary rheometer (AR2000ex manufactured by TA Instruments).
Measurement conditions / Geometry: 25mmφ parallel plate / GAP: 1mm
・ Frequency: 1 Hz
・ Distortion: 1%
Measurement temperature range: 80 to 240 ° C. (temperature increase rate of 3 ° C./min)
The evaluation criteria were as follows using the storage elastic modulus (G ′) at 180 ° C.
◎ (very good): G 'of 300 Pa or more
○ (Good): G 'of 100 Pa or more and less than 300 Pa
X (Inferior): G 'of less than 50 mPa
(Example 1)
500 ppm of tetra-n-butoxytitanium having a charge composition shown in Table 1 with respect to the polyvalent carboxylic acid, polyhydric alcohol, and polyvalent carboxylic acid was charged into a reaction vessel equipped with a distillation column.

  Next, the temperature was raised and heated so that the temperature in the reaction system became 265 ° C., this temperature was maintained, and the esterification reaction was carried out until no water was distilled from the reaction system. Subsequently, the temperature in the reaction system was set to 235 ° C., the pressure in the reaction vessel was reduced, and a condensation reaction was carried out while distilling the polyalcohol from the reaction system.

  The polycondensation was carried out until the torque of the stirring blade reached a value indicating a desired softening temperature. Next, stirring of the reaction apparatus was stopped, the inside of the apparatus was brought to normal pressure, the inside of the apparatus was pressurized with nitrogen, the reaction product was taken out from the lower part of the apparatus, and cooled to 100 ° C. or less to obtain a polyester resin. Next, the obtained resin was coarsely pulverized using a pulverizer equipped with a 3 mm mesh at the discharge port, further pulverized with a trio-brender pulverizer (manufactured by Trio Science Co., Ltd.), and averaged with a classifier (sieving). A resin powder having a diameter of 250 to 500 μm was obtained. Using this resin powder, water dispersibility, hot offset resistance, and storage stability were evaluated. The evaluation results are shown in Table 1.

(Examples 2 and 3 and Comparative Examples 1 to 4)
A polyester resin was obtained in the same manner as in Example 1 using the carboxylic acid component, polyhydric alcohol component, and catalyst having the preparation composition shown in Table 1. The results evaluated in the same manner as in Example 1 are shown in Table 1.

  In Comparative Example 1, since bis (2-hydroxyethyl) sodium salt of sulfoisophthalate was not used, water dispersibility was insufficient.

  In Comparative Example 2, since the bisphenol A alkylene oxide adduct was not used, the storage stability was insufficient.

  In Comparative Example 3, since a trivalent or higher monomer component was not used, the hot offset resistance was insufficient.

  In Comparative Example 4, water dispersibility was insufficient because polymerization was not performed using a titanium-based catalyst.

Claims (5)

At least one selected from trivalent or higher polyvalent carboxylic acids and trivalent or higher polyhydric alcohols, sodium bis (2-hydroxyethyl) sulfoisophthalate, and
A method for producing a polyester resin for toner, wherein a monomer mixture containing a bisphenol A alkylene oxide adduct is polycondensed using a titanium-based catalyst.   The monomer mixture contains at least one selected from trivalent or higher polyvalent carboxylic acids and trivalent or higher polyhydric alcohols in an amount of 1 to 25 mol parts per 100 mol parts of the polyvalent carboxylic acid component. A process for producing a polyester resin for toner according to claim 1.   The method for producing a polyester resin for toner according to claim 1, wherein the sodium bis (2-hydroxyethyl) sulfoisophthalate is sodium bis (2-hydroxyethyl) sulfoisophthalate.   4. The toner according to claim 1, wherein the titanium-based catalyst is at least one selected from a titanium alkoxide compound, a titanium carboxylate, a titanyl carboxylate, a titanyl carboxylate, and a titanium chelate compound. Of manufacturing polyester resin for use in a process To produce a polyester resin for a toner manufacturing method as claimed in any one of claims 4, to produce a toner containing a polyester resin for a toner obtained, the production method of the toner.