JP2018162395A - Polyester resin for toner and method for producing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a polyester resin which can obtain a toner excellent in storage property, is excellent in crushability and emulsion stability, and little contains a residual monomer, for both of toner production methods of a crushing method and a chemical method.SOLUTION: A method for producing a polyester resin includes a step of polymerizing a slurry solution containing a polyhydric alcohol component containing a bisphenol A alkylene oxide additive and a polyvalent carboxylic acid at 240°C or higher, where the slurry solution contains tri- or higher acid and/or alcohol, a ratio of an acid value (mgKOH/g) and a hydroxyl value (KOH/g) of the polyester resin satisfies acid value/hydroxyl value≥1.0. In the method for producing the polyester resin, preferably, the bisphenol A alkylene oxide additive is a bisphenol A ethylene oxide additive, and an average addition number is 2.2 to 4.0.SELECTED DRAWING: None

Description

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

In a method for obtaining an image by an electrophotographic printing method or an electrostatic charge developing method, fixing is performed after developing an electrostatic charge image formed on a photoreceptor with a toner charged in advance by friction.
Since an apparatus used for obtaining an image by these methods usually has a fixing portion which is a heating body, the temperature in the apparatus rises. For this reason, the toner is required not to block, that is, storability. In addition, the toner is also required to be free from contamination and fogging of the apparatus even during continuous printing, that is, durability.

The binder resin for toner has a great influence on the toner characteristics, and polystyrene resin, styrene-acrylic resin, polyester resin, epoxy resin, polyamide resin and the like are used. Among them, a polyester resin having a good performance balance has attracted particular attention.
For example, Patent Documents 1 and 2 disclose a polyester resin for toner containing a unit derived from a polyvalent carboxylic acid such as terephthalic acid and a unit derived from a polyhydric alcohol such as a bisphenol derivative at a specific ratio. .

By the way, examples of the toner production method include a pulverization method and a chemical method.
In the pulverization method, a binder resin and other toner compound (for example, pigment (colorant), release agent, etc.) are melt-kneaded, and the obtained kneaded material is finely pulverized with a pulverizer and classified to classify the toner. This method is widely used industrially.

In recent years, it has been desired to reduce the particle size of toner in order to achieve high image quality of formed images. However, in the pulverization method, energy and time required for pulverization tend to increase. Therefore, a chemical method that can efficiently reduce the particle size has attracted attention.
The chemical method is, for example, dissolving a binder resin or the like in an organic solvent, dispersing the obtained resin solution in an aqueous medium and emulsifying the binder resin, then removing the organic solvent, condensing the obtained emulsified particles, In this method, the condensed particles are separated, washed and dried.

JP 1997-73189 A JP 2007-264623 A

However, Patent Documents 1 and 2 do not describe manufacturing a toner by a chemical method using a polyester resin. In addition, when a toner is produced by a chemical method using an organic solvent, if a binder resin having a large amount of residual monomer is used, the stability of the emulsion deteriorates, the thermal characteristics of the obtained toner particles, and other toner compounds The blending state of the toner may become non-uniform, which may cause problems such as affecting the toner characteristics.
Therefore, when the toner is produced by a chemical method, it is important that the binder resin has a small amount of residual monomer.

Further, since the binder resin is emulsified in the chemical method, the binder resin is required to have excellent emulsifying properties.
Furthermore, if the resin cannot be pulverized, the productivity of the solvent dissolution time in the emulsification step is impaired, so a binder resin having excellent grindability is required.

  The present invention provides a toner having excellent storability, excellent pulverization property and emulsion stability, and a method for producing a polyester resin with little residual monomer for both the pulverization method and the chemical method. With the goal.

The present invention has the following aspects.
[1] A method for producing a polyester resin comprising a step of polymerizing a slurry solution containing a polyhydric alcohol component containing a bisphenol A alkylene oxide adduct and a polyvalent carboxylic acid component at 240 ° C. or higher, wherein the slurry solution is Polyester which contains a trivalent or higher acid and / or alcohol, and the ratio of the acid value (mgKOH / g) to the hydroxyl value (KOH / g) of the polyester resin satisfies the acid value / hydroxyl value ≧ 1.0. Manufacturing method of resin.
[2] The method for producing a polyester resin according to [2], wherein the bisphenol A alkylene oxide adduct is a bisphenol A ethylene oxide adduct.
[3] The method for producing a polyester resin according to [1] or [2], wherein an average addition mole number of the alkylene oxide adduct is 2.2 to 4.0.
[4] The production method according to any one of [1] to [3], wherein a trivalent or higher valent acid and / or alcohol is mixed with a bisphenol A ethylene oxide adduct and then polymerized at 240 ° C. or higher.
[5] The production method according to any one of [1] to [4], wherein polymerization is performed by adding isosorbide.
[6] A method for producing a toner, comprising a step of kneading a mixture containing the resin obtained by the above production method

  According to the method for producing a polyester resin of the present invention, a toner having excellent storage stability can be obtained, and a polyester resin for a toner having excellent pulverizability and emulsion stability and little residual monomer can be produced.

<Method for producing polyester resin>
The method for producing a polyester resin of the present invention is a method for producing a polyester resin comprising a step of polymerizing a slurry solution containing a polyhydric alcohol component containing a bisphenol A alkylene oxide adduct and a polyvalent carboxylic acid component at 240 ° C. or higher. The slurry solution contains a trivalent or higher acid and / or alcohol, and the ratio of the acid value (mgKOH / g) to the hydroxyl value (KOH / g) of the polyester resin is acid value / hydroxyl value ≧ 1. 0.0 is satisfied.
Hereinafter, the detail of the manufacturing method of the polyester resin of this invention is demonstrated.

  In the present invention, the “slurry solution” is a suspension in which a solid is dispersed in a liquid. Specifically, the slurry solution in this specification is a liquid material at 20 ° C. to 90 ° C., and is a solution obtained by dispersing a solid material using a stirring device or the like. For example, a polyester resin is prepared by using a slurry solution in which a solid material such as terephthalic acid or trimellitic anhydride is uniformly stirred and mixed with a solution obtained by mixing ethylene glycol or a liquid bisphenol derivative at 20 ° C. to 90 ° C. By performing the polymerization, it is possible to produce a polyester resin having a uniform softening temperature in the system and high quality stability.

<Polyhydric alcohol>
In the method for producing a polyester resin of the present invention, at least a bisphenol A alkylene oxide adduct (bisphenol A derivative) is used as a polyhydric alcohol component.
Examples of the bisphenol derivative include an alkylene oxide adduct of bisphenol A. Specifically, polyoxyethylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene- (2 .2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene- (2.3) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene- (2.6)- 2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene- (3.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene- (4.0) -2,2- Bis (4-hydroxyphenyl) propane, polyoxyethylene- (5.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxy Propylene- (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-hydroxyphenyl) propane, polyoxypropylene- (2.4) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3)- 2,2-bis (4-hydroxyphenyl) propane and the like can be mentioned.
Of these, polyoxyethylene- (2.2) -2,2-bis (4-hydroxyphenyl) propane is preferred for the purpose of imparting appropriate fixing strength and chargeability, and for the reduction of residual monomers, especially ethylene. Those having an addition mole number of (2.2) to (4.0) are preferred from the viewpoint that the storage stability of the toner can be maintained and emulsion stability can be imparted.
One of these may be used alone, or two or more of these may be used in combination so that the number of moles of ethylene added falls within (2.2) to (4.0).

As the polyhydric alcohol, it is preferable to use isosorbide or a bisphenol derivative in combination with the cyclohexane compound. By using isosorbide in combination, the pulverization property of the polyester resin and the storage stability of the toner tend to be improved. In particular, the improvement of the pulverization property can improve the productivity during toner production regardless of the pulverization method or the chemical method.
Examples of isosorbide include D-isosorbide and L-isosorbide.
These may be used individually by 1 type and may use 2 or more types together.

As the polyhydric alcohol, a divalent alcohol other than isosorbide and a bisphenol derivative (hereinafter also referred to as “other divalent alcohol”) or a trihydric or higher alcohol may be used in combination.
Examples of other dihydric alcohols include ethylene glycol, neopentyl glycol, propylene glycol, butanediol, polyethylene glycol, 1,2-propanediol, 1,4-butanediol, diethylene glycol, triethylene glycol, 1,4- Examples include cyclohexanedimethanol, cyclopentanediol, cyclohexanediol, hydrogenated bisphenol A, spiroglycol, dioxane glycol, dulcide, and hexide.
Among these, ethylene glycol, 1,2-propanediol, and 1,4-cyclohexanedimethanol are preferable from the viewpoint of easily designing the polymerization reactivity and the glass transition temperature (Tg) of the polyester resin to 40 ° C. or higher. 1,2-propanediol is particularly preferred.
These may be used individually by 1 type and may use 2 or more types together.

Examples of the trivalent or higher alcohol include glycerin, 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-trihydroxy Examples include methylbenzene.
Among these, glycerin, pentaerythritol, and trimethylolpropane are preferable.
These may be used individually by 1 type and may use 2 or more types together.
<Polyvalent carboxylic acid>
Examples of the polyvalent carboxylic acid include divalent carboxylic acids and trivalent or higher carboxylic acids.
Examples of the divalent carboxylic acid include aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, aliphatic dicarboxylic acids such as phthalic acid, sebacic acid, isodecyl succinic acid, maleic acid, fumaric acid, and adipic acid, and lower Examples thereof include alkyl esters and acid anhydrides. Examples of the lower alkyl ester of these dicarboxylic acids include monomethyl ester, monoethyl ester, dimethyl ester, diethyl ester and the like.
These may be used individually by 1 type and may use 2 or more types together. Moreover, you may use together with the below-mentioned trivalent or more carboxylic acid.

Examples of the trivalent or higher 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, and acid anhydrides thereof.
These may be used individually by 1 type and may use 2 or more types together. Moreover, you may use together with bivalent carboxylic acid.
<Trivalent or higher acid and / or alcohol>
In the method for producing a polyester resin of the present invention, a tri- or higher valent acid and / or alcohol is used. By using a trivalent or higher acid and / or alcohol, a polyester resin having high resin strength can be produced with high productivity.
Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,3,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, Examples include 2,4-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,2,7,8-octanetetracarboxylic acid, their acid anhydrides, and lower alkyl esters.
Among these, trivalent or higher carboxylic acids are preferably trimellitic acid and trimellitic anhydride in that they have a high boiling point and are unlikely to cause causative substances of volatile components generated from the toner.
These may be used individually by 1 type and may use 2 or more types together.
Examples of the trihydric or higher alcohol include glycerin, 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-trihydroxy Examples include methylbenzene.
Among these, glycerin and trimethylolpropane are preferable as the trivalent or higher alcohol.

<Ratio of acid value (mgKOH / g) and hydroxyl value (KOH / g) of polyester resin>
In the present invention, the ratio of the acid value (mgKOH / g) and the hydroxyl value (KOH / g) of the polyester resin satisfies the acid value / hydroxyl value ≧ 1.0. If it is the said range, there exists an effect which dispersion | distribution of coloring agents, such as a pigment and dye, becomes favorable.
In order to make the acid value / hydroxyl value within the above range, for example, the ratio of the acid to the alcohol in the feed composition is made higher than that of the alcohol, or an alcohol having only a primary hydroxyl group having high reactivity is used. Can be mentioned.
<Other ingredients>
In the production of the polyester resin, in order to adjust the number of terminal functional groups and improve the dispersibility of other materials, a monovalent monovalent monomer is added in addition to the polyvalent carboxylic acid and the polyhydric alcohol as long as the object of the present invention is not impaired. Carboxylic acid or monohydric alcohol may be used in combination.
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; cinnamic acid and olein Examples thereof include unsaturated carboxylic acids having one or more unsaturated double bonds in the molecule such as acid, linoleic acid and linolenic acid.
Examples of monovalent alcohols include aromatic alcohols having 30 or less carbon atoms such as benzyl alcohol; aliphatic alcohols having 30 or less carbon atoms such as oleyl alcohol, lauryl alcohol, cetyl alcohol, stearyl alcohol, and behenyl alcohol.
Each of these monovalent carboxylic acids and monovalent alcohols may be used alone or in combination of two or more.

<Catalyst>
Titanium catalysts have high reaction activity, and the esterification reaction time is shorter than when no catalyst is used or when other catalysts are used, improving the resin productivity and reducing the amount of resin oligomers. Easy to homogenize. Catalysts other than titanium catalysts, such as tin catalysts and antimony catalysts, are generally heterogeneous catalysts that are dispersed in the raw material. When water dispersion treatment is performed, particles are likely to aggregate, making them suitable for chemical toners. It tends to be difficult to obtain a stable particle size. In addition, tin catalysts and antimony catalysts are concerned as environmental pollutants and tend to be limited in use. Therefore, if the amount used is reduced to reduce the impact on the environmental load and aggregation, the reactivity during polymerization is low. Thus, the productivity is lowered due to the extension of the polymerization time.

The titanium catalyst may be liquid at room temperature (20 ° C.) or may be solid (powder), but the emulsifiability of the polyester resin is improved, especially the storage stability of the emulsion. From the viewpoint of properties, a liquid titanium catalyst is preferable.
An organic titanium compound is mentioned as a liquid titanium catalyst, An inorganic titanium compound is mentioned as a solid titanium catalyst.

Examples of the organic titanium compound include a titanium alkoxide compound having an alkoxy group, a carboxylic acid titanium compound, a carboxylic acid titanyl compound, a carboxylic acid titanyl salt compound, and a titanium chelate compound.
Examples of the titanium alkoxide compound having an alkoxy group include tetramethoxy titanium, tetraethoxy titanium, tetrapropoxy titanium, tetra-n-butoxy titanium, tetrapentoxy titanium, tetraoctoxy titanium, and the like.
Examples of titanium carboxylate compounds include titanium formate, titanium acetate, titanium propionate, titanium octoate, titanium oxalate, titanium succinate, titanium maleate, titanium adipate, titanium sebacate, titanium hexanetricarboxylate, and isooctanetricarboxylic acid. Titanium, octanetetracarboxylic acid titanium, decanetetracarboxylic acid titanium, benzoic acid titanium, phthalic acid titanium, terephthalic acid titanium, isophthalic acid titanium, 1,3-naphthalenedicarboxylic acid titanium, 4,4-biphenyldicarboxylic acid titanium, 2, 5-toluene dicarboxylic acid titanium, anthracene dicarboxylic acid titanium, trimellitic acid titanium, 2,4,6-naphthalene tricarboxylic acid titanium, pyromellitic acid titanium, 2,3,4,6-naphthalene tetracarboxylic acid titanium And the like.
Examples of the titanyl carboxylates include titanyl benzoate, titanyl phthalate, titanyl terephthalate, titanyl isophthalate, titanyl 1,3-naphthalenedicarboxylate, titanyl 4,4-biphenyldicarboxylate, and titanyl 2,5-toluene dicarboxylate. , 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, and the like.
The titanyl carboxylate compound is not particularly limited, and examples thereof include alkali metal (lithium, sodium, potassium, etc.) salts or alkaline earth metal (magnesium, calcium, barium, etc.) salts for the above-mentioned titanyl carboxylate compounds. .
Among these, tetrabutoxy titanium and tetrapropoxy titanium are preferable from the viewpoint of reactivity and the particle size of the aqueous dispersion. When a titanium chelate compound is used, the ligand is preferably selected from acetylacetone, ethyl acetoacetate, octylene glycol, triethanolamine, lactic acid, and ammonium lactate.
These may be used individually by 1 type and may use 2 or more types together.

Examples of the inorganic titanium compound include titanium, titanium oxide, titanium nitride, strontium titanate, lead titanate, barium titanate, potassium titanate, and titanium dioxide.
These may be used individually by 1 type and may use 2 or more types together.

<Production conditions for polyester resin>
The polyester resin of the present invention can be obtained by polymerizing a monomer mixture containing the above-described polycarboxylic acid and polyhydric alcohol and, if necessary, other components by a known polyester polymerization method.

The content of each component in the monomer mixture is as follows.
The content of the trivalent or higher carboxylic acid is preferably 0.1 to 23 mol%, more preferably 1 to 20 mol%, and still more preferably 1 to 15 mol% in 100 mol% of the polyvalent carboxylic acid. When the content of a trivalent or higher carboxylic acid is 0.1 mol% or higher, the resin strength of the polyester resin is further increased. In particular, when the content of the trivalent or higher carboxylic acid is 1 mol% or more, the productivity of the polyester resin is further improved. On the other hand, when the content of the trivalent or higher carboxylic acid is 23 mol% or less, the solvent solubility of the polyester resin and the storage stability of the toner are further improved. In addition, it is easy to obtain a polyester resin that is difficult to color while maintaining good productivity.

  The content of isosorbide is preferably 10% by weight or less, more preferably 7% by weight or less, still more preferably 5% by weight or less, and particularly preferably 3% by weight or less based on the total weight of the charged monomers. When the content of isosorbide is 10% by mass or less, it is easy to obtain a polyester resin having good storage stability, excellent pulverization properties, and hardly coloring. In addition, the polymerization stability of the polyester resin can be maintained well. When the content of isosorbide is 0.1 mol part or more, the resin strength of the polyester resin and the storage stability of the toner are further increased.

  The content of the bisphenol derivative is preferably more than 10 parts by mole and less than 95 parts by mole, more preferably 15 to 90 parts by mole, and particularly preferably 15 to 80 parts by mole with respect to 100 parts by weight of the polycarboxylic acid. If the content of the bisphenol derivative exceeds 10 mol parts, the solvent solubility of the polyester resin is further improved, and the emulsifiability of the polyester resin and the storage stability of the toner can be maintained well. In addition, it is easy to obtain a polyester resin excellent in transparency, hardly affects the color of the colorant used in the toner, and is suitable as a binder resin for color toners and clear toners. On the other hand, when the content of the bisphenol derivative is less than 95 mole parts, a polyester resin that is difficult to be colored is easily obtained. In addition, the storage stability of the toner is further improved.

The content of the other divalent alcohol is preferably 10 to 150 mol parts, more preferably 15 to 120 mol parts, still more preferably 20 to 100 mol parts, and more preferably 30 to 80 mol parts per 100 mol parts of the polyvalent carboxylic acid. A mole part is particularly preferred, and a 50 to 80 mole part is most preferred.
The content of the trivalent or higher alcohol is preferably 1 to 40 mol parts, more preferably 1 to 35 mol parts, and further preferably 1 to 30 mol parts with respect to 100 mol parts of the polyvalent carboxylic acid. In particular, when the content of trivalent or higher alcohol is 1 mol% or higher, the productivity of the polyester resin is further improved. On the other hand, when the content of the trihydric or higher alcohol is 30 mol% or less, the solvent solubility of the polyester resin and the storage stability of the toner are further improved. In addition, it is easy to obtain a polyester resin that is difficult to color while maintaining good productivity.

  In the method for producing a polyester resin of the present invention, the polymerization temperature is 240 ° C. or higher. The polymerization temperature is preferably 280 ° C. or lower. Moreover, 245-275 degreeC is more preferable. If the polymerization temperature is 240 ° C. or higher, productivity is good, and residual monomers such as terephthalic acid tend to be low. If it is 280 ° C. or lower, the polyester resin is decomposed and volatile components that cause odor It tends to be able to suppress by-products.

  The pH of the slurry during the polymerization charge is preferably 4 to 8 from the viewpoint of preventing the decomposition reaction during the polymerization. When the pH of the slurry is less than 4, oil is generated during the esterification reaction, which is likely to occur with the dehydration of the secondary and tertiary glycols, and it may be difficult to obtain a desired polyester resin. On the other hand, when the pH of the slurry exceeds 8, the hydrolysis reaction of the obtained polyester resin tends to proceed in a preferable polymerization temperature region, and as a result, it tends to be difficult to obtain a desired polyester resin.

  The viscosity of the alcohol at the time of polymerization is preferably 10 mPa · s or more and 200 mPa · s or less at 90 ° C., more preferably 20 mPa · s or more and 150 mPa · s or less, and 30 mPa · s or more and 100 mPa · s or less. It is particularly preferred. When the viscosity of the alcohol at 90 ° C. is 10 mPa · s or more, the dispersion of the carboxylic acid material having a valence of 2 or more is improved, and the localization of the acid component during the reaction is reduced. The amount of residual monomer of terephthalic acid, which is a lower monomer, can be reduced. On the other hand, if the viscosity of the alcohol at 90 ° C. is 200 mPa · s or more, it takes time to disperse the divalent and trivalent or higher carboxylic acids, which is not preferable.

  The polymerization end point is determined by, for example, the softening temperature. For example, the polymerization may be terminated after the condensation reaction is performed until the torque of the stirring blade reaches a value indicating a desired softening temperature. Here, “end polymerization” 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. Say. Alternatively, a few grams of the polymer may be sampled, cooled to room temperature, measured for softening temperature, and polymerized to a desired viscosity, and then terminated.

In the polymerization, if necessary, as long as the effects of the present invention are not impaired, a release agent component may be added to the monomer mixture for polymerization. By adding a release agent component to the monomer mixture and polymerizing, the toner fixability and wax dispersibility tend to be improved.
Further, for the purpose of obtaining the polymerization stability of the polyester resin, a stabilizer may be added to the monomer mixture for polymerization. Examples of the stabilizer include hydroquinone, methyl hydroquinone, hindered phenol compounds, and the like.

  The polyester resin thus obtained comprises a bisphenol A alkylene oxide adduct containing at least a polyol component containing a bisphenol A alkylene oxide adduct, a polycarboxylic acid component, and a trivalent or higher acid or / and alcohol. It is A ethylene oxide adduct, Comprising: The average addition mole number of ethylene oxide adduct is 2.2-4.0. The polyester resin preferably includes a structural unit derived from the bisphenol derivative, and may further include a structural unit derived from a divalent carboxylic acid, another divalent alcohol, or isosorbide.

The Tg of the polyester resin is preferably 40 ° C. or higher and lower than 75 ° C., more preferably 45 ° C. or higher from the viewpoint of storage stability, and more preferably 73 ° C. or lower from the viewpoint of low-temperature fixability. Especially preferably, it is 48-70 degreeC.
The Tg of the polyester resin is determined by measurement with a differential differential calorimeter. Specifically, after heating at 100 ° C. for 10 minutes and performing a melt quench, the baseline on the low temperature side of the chart when measured at a heating rate of 5 ° C./min, and the tangent line of the endothermic curve in the vicinity of Tg The temperature of the intersection is obtained and this is defined as Tg.

T4 of the polyester resin is preferably 80 to 160 ° C, more preferably 80 to 155 ° C, and further preferably 80 to 150 ° C. If the T4 of the polyester resin is 80 ° C. or higher, the resin strength as the binder resin can be maintained better, and if it is 160 ° C. or lower, the low temperature fluidity is excellent and the toner can be fixed at a low temperature.
T4 of the polyester resin is measured with a 1 mmφ × 10 mm nozzle under the condition of a constant temperature increase under a load of 294 N (30 Kgf) and a temperature increase rate of 3 ° C./min. When 4 mm in 1.0 g of sample flows out Temperature.

The acid value of the polyester resin is preferably 1 to 90 mgKOH / g, more preferably 1 to 85 mgKOH / g, and still more preferably 1 to 80 mgKOH / g. If the acid value of the polyester resin is 1 mgKOH / g or more, the chargeability is good, and if it is 90 mgKOH / g or less, moisture absorption can be suppressed.
The acid value of the polyester resin is a value obtained by dissolving the polyester resin in benzyl alcohol and titrating with 0.02 N KOH benzyl alcohol solution using phenolphthalein as an indicator.

  In the present invention, the ratio between the acid value (mgKOH / g) and the hydroxyl value (mgKOH / g) of the polyester resin satisfies the acid value / hydroxyl value ≧ 1.0. When the acid value / hydroxyl value ≧ 1.0, the dispersion of a colorant such as a pigment or dye is excellent.

500-1 million are preferable, as for the mass average molecular weight (Mw) of a polyester resin, 1000-800000 are more preferable, 5000-500000 are more preferable. If the Mw of the polyester resin is 500 or more, the durability of the toner is more excellent, and if it is 1000000 or less, the low-temperature fixability of the toner is excellent.
The peak top molecular weight (Mp) of the polyester resin is preferably 1000 to 300000, more preferably 1000 to 30000, and still more preferably 1000 to 20000.
Mw and Mp of the polyester resin can be measured using gel permeation chromatography (GPC). For example, it can be determined as a molecular weight in terms of polystyrene using a solvent such as tetrahydrofuran as an eluent.

<Effect>
According to the method for producing a polyester resin of the present embodiment, it is possible to obtain a polyester resin that is excellent in grindability and emulsion stability and has a small amount of residual monomer. In addition, materials for both the pulverization method and the chemical method that are excellent in storage stability can be provided.

<Toner production method>
<Dissolution process>
The dissolution step is a step of dissolving a polyester resin in an organic solvent to obtain a resin solution.
The polyester resin is preferably coarsely pulverized to about several mm before being dissolved in the organic solvent. By coarsely pulverizing the polyester resin, the polyester resin is easily dissolved in an organic solvent.
Further, the coarsely pulverized polyester resin may be finely pulverized to about several hundred μm (specifically, the average particle diameter is less than 1 mm). By finely pulverizing the polyester resin, the polyester resin is more easily emulsified in the emulsification step described below.

(Organic solvent)
The organic solvent is not particularly limited as long as it can dissolve the polyester resin, and examples thereof include aromatic organic solvents, ketone organic solvents, ester organic solvents, alcohol organic solvents, glycol ether organic solvents, and the like.
Examples of the aromatic organic solvent include toluene, xylene, orthoxylene, metaxylene, paraxylene, benzene, ethylbenzene and the like.
Examples of the ketone organic solvent include methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, and acetone.
Examples of the ester organic solvent include ethyl acetate, n-butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate and the like.
Examples of the alcohol organic solvent include methanol, ethanol, isobutanol, isopropyl alcohol, 2-ethyl-1-hexanol, benzyl alcohol, and the like.
Examples of the glycol ether organic solvent include methyl carbitol, ethyl carbitol, butyl carbitol, methyl triglycol and the like.

  110-700 mass parts is preferable with respect to 100 mass parts of polyester resins, and, as for the usage-amount of an organic solvent, 120-600 mass parts is more preferable, and 150-500 mass parts is more preferable. If the usage-amount of an organic solvent is 110 mass parts or more, it will become easy to control the volume average particle diameter of the resin particle obtained by the below-mentioned emulsification process. In particular, when the amount of the organic solvent used is 150 parts by mass or more, the volume average particle diameter of the resin particles tends to be 1.0 μm or less. Also, the storage stability of the resin particles is improved. On the other hand, when the amount of the organic solvent used is 700 parts by mass or less, the solvent removal time when the organic solvent is distilled off in the emulsification step is shortened, and the productivity is improved. In particular, when the amount of the organic solvent used is 500 parts by mass or less, the organic solvent can be distilled off in a shorter time, and the productivity is further improved.

<Emulsification process>
The emulsification step is a step of adding resin to the resin solution obtained in the dissolution step to emulsify the polyester resin to obtain a resin particle dispersion.
The resin particle dispersion is obtained by applying a shearing force to a mixture of the resin solution and water. At this time, a shearing force may be applied while heating. Further, the organic solvent may be distilled off while heating.
For the application of the shearing force, for example, a rotary shearing homogenizer, a homomixer, a ball mill having media, a sand mill, a dyno mill, or the like may be used.
When applying a shearing force while heating, it is preferably performed at Tg or higher of the polyester resin, more preferably at 2 ° C or higher than Tg of the polyester resin, and more preferably 5 ° C or higher. If a shearing force is applied while heating at a Tg or higher of the polyester resin, the viscosity of the mixture of the resin solution and water is sufficiently lowered, and the polyester resin can be easily emulsified.

The volume average particle diameter of the resin particles is preferably 0.01 μm or more and less than 2 μm, and more preferably 0.01 to 1 μm. When the volume average particle size of the resin particles is less than 0.01 μm, the amount of the flocculant used tends to increase in the aggregation step described later. On the other hand, if the volume average particle size of the resin particles is 2 μm or more, the number of particles until the desired toner particle size is reached is small, and uniform material mixing becomes difficult.
The volume average particle diameter of the resin particles is measured with a laser diffraction particle size distribution measuring apparatus.

  5-50 mass% is preferable, as for content (solid content) of the resin particle contained in a resin particle dispersion, 10-40 mass% is more preferable, and 15-35 mass% is further more preferable. When the content of the resin particles is 5% by mass or more, the aggregated particles are easily formed in the aggregation process, and the toner productivity is improved. On the other hand, if the content of the resin particles is 50% by mass or less, the resin particle dispersion is difficult to increase in viscosity and the operability is hardly reduced.

  In the emulsification step, a basic compound or a surfactant may be added to the mixture of the resin solution and water for the purpose of stabilizing the dispersed state of the resin particles.

(Basic compound)
As a basic compound, any of an inorganic basic compound and an organic basic compound may be sufficient.
Examples of the inorganic basic compound include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide; weak acid salts such as alkali metal carbonates and acetates or partially neutralized salts; ammonia and the like. .
Examples of the organic basic compound include alkylamines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine and triethylamine; alkanolamines such as diethanolamine; fatty acid salts such as sodium succinate and sodium stearate.
These may be used individually by 1 type and may use 2 or more types together.

  As for the usage-amount of a basic compound, 0.01-20 mass parts is preferable with respect to 100 mass parts of polyester resins.

(Surfactant)
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. A nonionic surfactant such as polyoxyethylene alkyl ether;
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 may be used individually by 1 type and may use 2 or more types together.

  As for the usage-amount of surfactant, 0.01-20 mass parts is preferable with respect to 100 mass parts of polyester resins.

<Aggregation process>
The aggregation step is a step of aggregating the resin particles in the resin particle dispersion obtained in the emulsification step to obtain an aggregated particle dispersion.
In the aggregation step, for example, an aggregating agent is added to the resin particle dispersion, and the pH of the resin particle dispersion is adjusted to about 2 to 5 under acidic conditions, and a dispersion stabilizer is added as necessary. Then, it heats from Tg of a resin particle to about 80 degreeC, the resin particle in a resin particle dispersion is aggregated, and an aggregated particle is formed. In addition, the resin particle dispersion is stirred with a rotary shear type homogenizer, and a flocculant is added at room temperature of about 25 ° C., and the pH of the resin particle dispersion is adjusted to about 2 to 5 below the acidic condition. Accordingly, after adding a dispersion stabilizer, the above heat treatment may be performed to form aggregated particles.

As the aggregating agent, those showing a salting-out effect are preferable, and examples thereof include inorganic metal salts and divalent or higher-valent metal complexes. Moreover, when a surfactant is contained in the resin particle dispersion, a surfactant having a polarity opposite to that of the surfactant may be used as an aggregating agent.
Examples of inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate.

The use amount of the aggregating agent is preferably 0.01 to 20 parts by mass, more preferably 0.01 to 15 parts by mass with respect to 100 parts by mass of the polyester resin, from the viewpoint of aggregation ability and toner storage stability. 01-10 mass parts is further more preferable.
The flocculant dissolved in an aqueous medium is preferably added to the resin particle dispersion, and sufficient stirring is preferably performed at the time of addition of the flocculant and after completion of the addition.

Further, a water-soluble chelating agent may be used instead of the flocculant.
Examples of the chelating agent include tartaric acid, citric acid, ethylenediaminetetraacetic acid (EDTA), and the like.
0.01-5.0 mass parts is preferable with respect to 100 mass parts of polyester resins, and, as for the usage-amount of a chelating agent, 0.1 mass part or more and less than 3.0 mass parts are more preferable.

In addition, when a component other than the polyester resin, such as a colorant, a charge control agent, a release agent, a flow modifier, and a magnetic substance, is blended in the toner, these blends are also emulsified separately to form a dispersion. It may be prepared, mixed with the resin particle dispersion, and aggregated.
Compound dispersions such as a colorant dispersion, a charge control agent dispersion, a release agent dispersion, a flow modifier dispersion, and a magnetic dispersion are prepared in the same manner as the resin particle dispersion.

  When agglomerating in a state where the resin particle dispersion and the blend dispersion are mixed, the polyester resin and the blend are hetero-aggregated to form aggregated particles including the polyester resin and the blend. In this case, the use amount of the flocculant is preferably 0.01 to 20 parts by mass, more preferably 0.01 to 15 parts by mass, with respect to 100 parts by mass in total of the polyester resin and the blend, and 0.01 to 10 parts by mass is more preferable.

When obtaining toner particles having a core-shell structure, for example, the resin particles in the resin particle dispersion may be aggregated, and then the formulation dispersion may be added to aggregate the formulation. By doing so, toner particles composed of a core portion formed of a polyester resin and a shell portion formed of a compound can be obtained. Alternatively, the resin particles may be aggregated by adding the resin particle dispersion after aggregating the compound in the compound dispersion. By doing so, toner particles composed of a core portion formed of the blend and a shell portion formed of the polyester resin are obtained.
When a plurality of formulation dispersions are used, the formulations in all the formulation dispersions may be aggregated simultaneously, or after the formulation in any formulation dispersion is agglomerated, another formulation dispersion is added. Further, it may be added and aggregated.
It is preferable to use a flocculant for agglomeration of the blend in the blend dispersion.

Examples of the colorant include carbon black, nigrosine, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow, rhodamine dyes, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane dye, monoazo, and disazo. And condensed azo dyes or pigments. These dyes and pigments may be used alone or in combination of two or more.
When the toner is used as a color toner, examples of yellow colorants include benzidine yellow, monoazo dyes, and condensed azo dyes, and examples of magenta colorants include quinacridone, rhodamine dyes, and monoazo dyes. Examples of cyan colorants include phthalocyanine blue.
The content of the colorant is not particularly limited, but is preferably 2 to 10% by mass with respect to the total mass of the toner from the viewpoint of excellent toner color tone, image density, and thermal characteristics.

Charge control agents include quaternary ammonium salts and positively chargeable charge control agents such as basic or electron donating organic substances; metal chelates, metal-containing dyes, acidic or electron withdrawing organic substances, etc. Examples include a negatively chargeable charge control agent.
When the toner is used as a color toner, a charge control agent that is colorless or light in color and has less color disturbance to the toner is suitable. Examples of such a charge control agent include salicylic acid or alkylsalicylic acid chromium, zinc, Examples thereof include metal salts with aluminum and the like, metal complexes, amide compounds, phenol compounds, naphthol compounds and the like. Furthermore, a vinyl polymer having a styrene, acrylic acid, methacrylic acid or sulfonic acid group may be used as the charge control agent.
The content of the charge control agent is preferably 0.5 to 5% by mass with respect to the total mass of the toner. If the content of the charge control agent is 0.5% by mass or more, the charge amount of the toner tends to be a sufficient level, and if it is 5% by mass or less, a decrease in the charge amount due to aggregation of the charge control agent is suppressed. It tends to be.

As the mold release agent, carnauba wax, rice wax, beeswax, polypropylene wax, polyethylene wax, synthetic ester wax, paraffin wax, taking into account the toner releasability, storage stability, fixability, color developability, etc. Fatty acid amides, silicone waxes and the like can be appropriately selected and used. These may be used individually by 1 type and may use 2 or more types together.
The melting point of the release agent may be appropriately determined in consideration of the toner performance.
The content of the release agent is not particularly limited, but is preferably 0.3 to 15% by mass with respect to the total mass of the toner because it affects the toner performance. The lower limit of the content of the release agent is more preferably 1% by mass or more, and particularly preferably 2% by mass or more. Further, the upper limit value of the content of the release agent is more preferably 13% by mass or less, and particularly preferably 12% by mass or less.

Additives such as flow modifiers include flow improvers such as fine powdered silica, alumina, titania; inorganic fine powders such as magnetite, ferrite, cerium oxide, strontium titanate, conductive titania; styrene resin, acrylic Resistance control agents such as resins; lubricants and the like are used, and these are used as an internal additive or an external additive.
The content of these additives is preferably 0.05 to 10% by mass with respect to the total mass of the toner. If the content of these additives is 0.05% by mass or more, the effect of improving the performance of the toner tends to be sufficiently obtained, and if it is 10% by mass or less, the image stability of the toner tends to be good. is there.

When the toner obtained by the present invention is used as a magnetic one-component developer, the toner preferably contains a magnetic material.
Examples of magnetic materials include ferromagnetic alloys containing ferrite, magnetite, iron, cobalt, nickel, etc .; alloys that do not contain compounds or ferromagnetic elements, but become ferromagnetic when appropriately heat-treated (for example, manganese) -So-called Heusler alloy, chromium dioxide, etc. containing manganese and copper such as copper-aluminum and manganese-copper-tin.
The content of the magnetic substance is not particularly limited, but it is preferably 3 to 70% by mass with respect to the total mass of the toner because it greatly affects the pulverizability of the toner. If the content of the magnetic material is 3% by mass or more, the charge amount of the toner tends to be a sufficient level, and if it is 70% by mass or less, the fixability and grindability of the toner tend to be good. The upper limit of the content of the magnetic material is more preferably 60% by mass or less, and particularly preferably 50% by mass or less.

<Fusion / unification process>
The fusing / merging step is a step of fusing and fusing the agglomerated particles in the agglomerated particle dispersion obtained in the aggregating step to obtain a particulate toner (hereinafter also referred to as “toner particles”).
In the coalescence / union process, for example, the aggregated particle dispersion is heated to about 80 ° C. from the Tg of the polyester resin to fuse and coalesce the aggregated particles to form toner particles.
Before heating the aggregated particle dispersion, the aggregated particle dispersion is cooled, the pH of the aggregated particle dispersion is adjusted to 3 to 10, or an aggregation stopper is added to the aggregated particle dispersion. It is preferable to stop the aggregation.

The volume average particle diameter of the toner particles is preferably 3 to 15 μm, and more preferably 5 to 10 μm. When the volume average particle diameter of the toner particles is 3 μm or more, the productivity tends to be good, and the problem of pneumoconiosis tends not to occur. On the other hand, if the volume average particle diameter of the toner particles is 15 μm or less, a high-quality image tends to be stably formed.
The volume average particle diameter of the toner particles is measured with a laser diffraction particle size distribution measuring apparatus.

<Post-processing process>
In the toner manufacturing method of the present embodiment, after the fusion / unification process, a post-treatment process such as a washing process, a solid-liquid separation process, and a drying process may be performed. Toner particles are obtained.

In the washing step, it is preferable to perform substitution washing with ion-exchanged water sufficiently from the viewpoint of chargeability.
In the solid-liquid separation step, it is preferable to carry out a filtration method such as suction filtration or pressure filtration from the viewpoint of productivity.
In the drying step, it is preferable to carry out a drying method such as freeze drying, flash jet drying, fluidized drying, and vibration fluidized drying from the viewpoint of productivity.

  An external additive such as a flow modifier may be added to the toner thus obtained. When toner is used as a two-component developer, a carrier such as iron powder, magnetite powder or ferrite powder is added to the toner.

  Next, the pulverized toner using the polyester resin of the present invention will be described.

  Colorants include carbon black, nigrosine, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow, rhodamine dyes, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane dye, monoazo, disazo, Examples thereof include condensed azo dyes or pigments. These dyes and pigments can be used alone or in admixture of two or more. In the case of a full-color toner, yellow includes benzidine yellow, monoazo dyes, condensed azo dyes, magenta, quinacridone, rhodamine dyes, monoazo dyes, cyan, phthalocyanine blue, and the like. The content of the colorant is not particularly limited, but is preferably 2 to 10% by mass in the toner from the viewpoint of the toner color tone, image density, and thermal characteristics.

  Examples of the charge control agent include a quaternary ammonium salt as a positive charge control agent and a basic or electron donating organic substance, and as a negative charge control agent, a metal chelate, a metal-containing dye, an acid or electron withdrawing property. Organic materials and the like. In the case of color toners, it is important that the charge control agent is colorless or light color and does not cause any color tone problems on the toner. Examples include metal salts, metal complexes, amides of salicylic acid or alkylsalicylic acid with chromium, zinc, aluminum, etc. A compound, a phenol compound, a naphthol compound, etc. are mentioned. Furthermore, a vinyl polymer having a styrene, acrylic acid, methacrylic acid or sulfonic acid group may be used as the charge control agent.

  The content of the charge control agent is preferably 0.5 to 5% by mass in the toner. When the content of the charge control agent is 0.5% by mass or more, the charge amount of the toner tends to be a sufficient level, and when the content is 5% by mass or less, a decrease in the charge amount due to aggregation of the charge control agent is suppressed. It tends to be.

  As the mold release agent, carnauba wax, rice wax, beeswax, polypropylene wax, polyethylene wax, synthetic ester wax, paraffin wax, taking into account the toner releasability, storage stability, fixability, color developability, etc. Fatty acid amides, silicone waxes and the like can be appropriately selected and used. These can be used alone or in combination of two or more. The melting point of the release agent can be appropriately selected and used in consideration of the toner performance. The content of the release agent is not particularly limited, but is preferably 0.3 to 15% by mass in the toner because it affects the toner performance. The lower limit of the content of the release agent is more preferably 1% by mass or more, and particularly preferably 2% by mass or more. Further, the upper limit value of the content of the release agent is more preferably 13% by mass or less, and particularly preferably 12% by mass or less.

Additives such as flow modifiers include fine powder silica, alumina, titania and other fluidity improvers, magnetite, ferrite, cerium oxide, strontium titanate, conductive titania and other inorganic powders, styrene resins, acrylics Examples thereof include resistance adjusting agents such as resins and lubricants, and these are used as an internal additive or an external additive.
The content of these additives is preferably 0.05 to 10% by mass in the toner. When the content of these additives is 0.05% by mass or more, a toner performance-modifying effect tends to be sufficiently obtained, and when it is 10% by mass or less, the image stability of the toner tends to be good. is there.

  Further, a resin other than the present invention may be used as long as the effects of the present invention are not impaired. For example, a polyester resin, a styrene resin, a styrene-acrylic resin, a cyclic olefin resin, a methacrylic acid in a range other than the above physical property values. Resin, epoxy resin and the like, and can be used alone or in admixture of two or more.

The toner of the present invention can be used as any one of a magnetic one-component developer, a non-magnetic one-component developer, and a two-component developer.
When used as a magnetic one-component developer, it contains a magnetic substance, and as a magnetic substance, in addition to a ferromagnetic alloy containing ferrite, magnetite, iron, cobalt, nickel, etc., it does not contain a compound or a ferromagnetic element. Examples thereof include alloys that exhibit ferromagnetism by appropriate heat treatment, such as so-called Heusler alloys containing manganese and copper, such as manganese-copper-aluminum and manganese-copper-tin, and chromium dioxide.
The content of the magnetic substance is not particularly limited, but is preferably 3 to 70% by mass in the toner because it greatly affects the pulverizability of the toner. When the content of the magnetic material is 3% by mass or more, the charge amount of the toner tends to be at a sufficient level, and when it is 70% by mass or less, the fixability and grindability of the toner tend to be good. The lower limit of the content of the magnetic substance is more preferably 3% by mass or more, and particularly preferably 3% by mass or more. Further, the upper limit of the content of the magnetic material is more preferably 60% by mass or less, and particularly preferably 50% by mass or less.
When used as a two-component developer, it is used in combination with a carrier. As the carrier, magnetic substances such as iron powder, magnetite powder and ferrite powder, those whose surfaces are coated with a resin coating, magnetic carriers and the like can be used. As the coating resin for the resin coating carrier, it is possible to use styrene resin, acrylic resin, styrene acrylic copolymer resin, silicone resin, modified silicone resin, fluorine resin, a mixture of these resins, etc. it can.
The toner containing the polyester resin for toner of the present invention can be produced by a known method.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

"Measurement and evaluation methods"
<Measurement of glass transition temperature (Tg)>
The Tg of the polyester resin was measured 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 using a differential differential calorimeter (“DSC-60” manufactured by Shimadzu Corporation). . The measurement sample was 10 mg ± 0.5 mg weighed in an aluminum pan, melted at 100 ° C. above the glass transition temperature for 10 minutes, and then rapidly cooled using dry ice.

<Measurement of softening temperature (T4)>
T4 of the polyester resin is a resin sample using a flow tester (manufactured by Shimadzu Corporation, “CFT-500D”) with a 1 mmφ × 10 mm nozzle, a load of 294 N, and a uniform heating rate of 3 ° C./min. The temperature at which 4 mm in 1.0 g flowed out was measured, and this was defined as the softening temperature.

<Measurement of acid value (AV)>
The AV of the polyester resin was measured as follows.
About 0.2 g of the polyester resin was precisely weighed in a branched Erlenmeyer flask (A (g)), 10 mL of benzyl alcohol was added, and the mixture was heated with a heater at 230 ° C. for 15 minutes under a nitrogen atmosphere to dissolve the polyester resin. After allowing to cool to room temperature, 10 mL of benzyl alcohol, 20 mL of chloroform and several drops of phenolphthalein solution were added, and titrated with a 0.02N KOH solution (titrate = B (mL), titer of KOH solution = p). . A blank measurement was performed in the same manner (titrated amount = C (mL)), and calculation was performed according to the following formula.
Acid value (mgKOH / g) = {(BC) × 0.02 × 56.11 × p} / A

<Measurement of hydroxyl value>
The hydroxyl value of the polyester resin was measured as follows.
Solution 1: About 5 g of polyester resin was precisely weighed in a branched Erlenmeyer flask (A (g)), and 50 mL of THF was added to dissolve the polyester resin. Solution 2: 30 mL of a dimethylaminopyridine THF solution prepared by dissolving 5 g of N, N-dimethylaminopyridine in 500 mL of THF is added to “Solution 1”. An acetic anhydride-THF solution in which 200 mL of THF is added to 22 mL of acetic anhydride is prepared, 10 mL of this solution is added to “Solution 2”, and the mixture for 20 minutes is referred to as “Solution 3”. 3 mL of ion exchange water is added to “Solution 3” and mixed for 20 minutes to obtain “Solution 4”. A solution obtained by adding 50 mL of THF to “solution 4” is referred to as “solution 5”. A solution obtained by adding 25 mL of a 0.5 N KOH methanol solution and a phenolphthalein indicator to “solution 5” is referred to as “solution 6”. “Solution 6” is titrated with a 0.5 N KOH methanol solution, and the amount of addition at the point where the solution is colored in a slightly purple color is measured (B (mL)). The titer (C (mL)) required at the time of blank measurement was also confirmed at the same time, and calculated according to the following formula using the titer p of 0.5N-KOH methanol solution.
Hydroxyl value (mgKOH / g) = [acid value (described in 0082)] + {(CB) × 0.5 × 56.11 × p} / A

<Measurement of mass average molecular weight (Mw) and peak molecular weight (Mp)>
The Mw and Mp of the polyester resin were determined by standard polystyrene conversion from the retention time corresponding to the peak value of the obtained elution curve by the GPC method. The peak value of the elution curve is a point where the elution curve shows a maximum, and when there are two or more maximum values, the elution curve gives the maximum value. The measurement conditions are shown below.
・ Equipment: “HLC8020” manufactured by Toyo Soda Industry Co., Ltd.
Column: manufactured by Toyo Soda Industry Co., Ltd., “TSKgelGMHXL”, (column size: 7.8 mm (ID) × 30.0 cm (L)) connected in series. Oven temperature: 40 ° C.
・ Eluent: THF
Sample concentration: 4 mg / 10 mL
Filtration conditions: Filter sample solution with 0.45 μm Teflon membrane filter Flow rate: 1 mL / min Injection volume: 0.1 mL
・ Detector: RI
Standard polystyrene sample for preparing calibration curve: TSK standard, A-500 (molecular weight 5.0 × 10 ² ), A-2500 (molecular weight 2.74 × 10 ³ ), F-2 (molecular weight 1) manufactured by Toyo Soda Kogyo Co., Ltd. .96 × 10 ⁴ ), F-20 (molecular weight 1.9 × 10 ⁵ ), F-40 (molecular weight 3.55 × 10 ⁵ ), F-80 (molecular weight 7.06 × 10 ⁵ ), F-128 ( Molecular weight 1.09 × 10 ⁶ ), F-288 (molecular weight 2.89 × 10 ⁶ ), F-700 (molecular weight 6.77 × 10 ⁶ ), F-2000 (molecular weight 2.0 × 10 ⁷ ).

<Evaluation of polymerization stability>
Weigh accurately 1 g of polyester resin. Dissolve 30 ml of resin and chloroform (for liquid chromatography) in a 100 ml separatory funnel. After adding 25 ml each of 6.8% phosphoric acid water and 3.3% aqueous ammonia, treating with a shaker for 30 minutes (speed 4), and allowing to stand overnight, the supernatant liquid is shown in a liquid black graph under the following conditions. The amount of terephthalic acid monomer was measured and evaluated according to the following criteria.
Liquid chromatograph measurement conditions LC-20A manufactured by Shimadzu Corporation
Column: Shim-pack WAX-1 4.6mmID × 15cm
Carrier liquid: 0.3M-NH4H2PO4 + 10% CH3CN / H2O
Flow rate: 1.0ml / mi
Column temperature: 40 ° C
Detector (UV): Wavelength 210nm
Sample volume: 20 μL (auto injector)
○ (Good): Residual monomer amount of terephthalic acid is less than 10,000 ppm x (Inferior): Residual monomer amount of terephthalic acid is 10,000 ppm or more

<Evaluation of emulsion stability>
20 g of the polyester resin was dissolved in 80 g of methyl ethyl ketone. After adding 5 mass% ammonia aqueous solution to the methyl ethyl ketone solution in which the polyester resin was dissolved until the acid value was neutralized 100%, distilled water was further added. The amount of distilled water added was 80 g in total with the amount of aqueous ammonia solution added. Subsequently, it stirred for 5 minutes at the rotation speed of 8000 rpm using the stirrer (the product made by IKA, "Ultramix"). Then, it moved to the round bottom flask and installed in the 70 degreeC water bath, and stirred and pressure-reduced and distilled methyl ethyl ketone. After the mass of the distillate exceeded 80 g, decompression was stopped and an emulsion was obtained.
The particle size of the obtained emulsion was measured using a laser diffraction / scattering particle size distribution measuring apparatus (“LA-960” manufactured by Horiba, Ltd.), and the median particle size of the emulsion was 0.1 to 0. It was confirmed to be 3 μm.
2 g of the obtained emulsion was weighed in an aluminum dish shape, processed at a dryer adjusted to 80 kPaabs or less at 80 ° C. for 2 hours, and the solid content (A) of the emulsion was measured. The solid content (B) of the emulsion after standing at 20 ° C. for 7 days was measured by the same method as described above. The difference between the solid content (B) and the solid content (A): Δ was used to evaluate the emulsion stability using the following indicators. In addition, the difference in the solid content was rounded off and the amount of change after the decimal point was handled as an integer.
◎ (Best): Δ is less than 2 wt% ○ (Good): Δ is 2 wt% or more and less than 5 wt% Δ (Usable): Δ is 5 wt% or more and less than 7 wt% × (Inferior): Δ is 7 wt% or more

<Evaluation of preservability>
The storage stability of the toner was evaluated as follows.
First, 10 g of the coarsely pulverized polyester resin was dissolved in 40 g of methyl ethyl ketone to obtain a resin solution. After mixing 50 g of the obtained resin solution and 50 g of a 5 mass% aqueous ammonia solution, the mixture was heated and mixed at 80 ° C., and the pressure was reduced to 3 kPa abs or less to distill off methyl ethyl ketone to obtain a resin particle dispersion.
Separately, anhydrous aluminum sulfate as a flocculant was dissolved in distilled water to a concentration of 0.3% by mass to prepare a flocculant solution.
While stirring the obtained resin particle dispersion using a homogenizer (“ULTRA-TURRAX T25 digital” manufactured by IKA) at a rotation speed of 5000 rpm, the flocculant solution was added dropwise, and 90% of the resin particles in the resin particle dispersion were obtained. % Or more was agglomerated. Thereafter, the aggregated particles were dried by freeze drying.
Aggregated particles 3g ± 0.5g after drying were weighed in an aluminum pan and stored for 72 hours in a thermo-hygrostat (manufactured by Satake Chemical Machinery Co., Ltd.) adjusted to a temperature of 50 ° C. and a humidity of 50%.
For the aggregated particles on the aluminum pan after storage in a thermostatic chamber, the ratio of the aggregated particles (aggregated particle passage rate) that passed through a sieve having an opening of 250 μm (60 mesh) was determined from the following formula.
Aggregated particle passage rate (%) = (aggregated resin passed through a sieve having an opening of 250 μm (g) / aggregated particles before passing through a sieve having an opening of 250 μm) (g) × 100
The preservability of the polyester resin was evaluated based on the following evaluation criteria from the previously obtained aggregate particle passage rate. Since the storage stability of the toner is easily influenced by the polyester resin contained in about 80% of the constituent components of the toner, the storage stability of the polyester resin is regarded as the storage stability of the toner.
○ (Good): Aggregated particle passage rate is 80% or more.
Δ (usable): Aggregated particle passage rate is 70% or more and less than 80%.
X (Inferior): Aggregated particle passage rate is less than 70%.

<Example 1>
<Manufacture of polyester resin>
Into the polyhydric alcohol having the charging composition shown in Table 1, 1000 ppm of tetra-n-butoxytitanium with respect to the polyvalent carboxylic acid is put into a stainless steel reaction vessel heated to 70 ° C., and stirred at 200 rpm for 5 minutes. After that, 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 270 ° C., this temperature was maintained, and the esterification reaction was carried out until no water was distilled from the reaction system. Next, the temperature in the reaction system was 245 ° C., the pressure in the reaction vessel was reduced, and a condensation reaction was carried out while distilling polyalcohol from the reaction system.
After the inside of the apparatus is brought to atmospheric pressure with nitrogen during the condensation reaction, about 3 g of resin is sampled from the reaction vessel, the resin is cooled to room temperature, the softening temperature is measured, and sampling is performed until the softening temperature shown in Table 1 is reached. The polymerization was repeated repeatedly.
After confirming that the desired softening temperature has been reached, 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, A polyester resin was obtained. The obtained polyester resin was coarsely pulverized using a pulverizer equipped with a 3 mm mesh at the discharge port.
The obtained polyester resin was measured for glass transition temperature, softening temperature, acid value, hydroxyl value, number average molecular weight, mass average molecular weight and peak molecular weight, and evaluated for polymerization stability, emulsion stability, storage stability and grindability. These results are shown in Table 1.

<Manufacture of toner>
100 g of the coarsely pulverized polyester resin was dissolved in 400 g of methyl ethyl ketone to obtain a resin solution.
After mixing 500 g of the obtained resin solution and 400 g of a 5 mass% aqueous ammonia solution, the mixture was heated and mixed at 80 ° C., and the pressure was reduced to 3 kPa abs or less to distill off methyl ethyl ketone. A 2 μm resin particle dispersion was obtained.
10 g of a colorant (manufactured by BASF, “PigmentRed122”), 40 g of distilled water, and 1 g of an anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., “Neogen R”) are homogenizers (manufactured by IKA, “ULTRA-TURRAX” T25 digital ") and mixed with stirring. Furthermore, using an ultrasonic device (manufactured by Sharp Corporation, “UT-206H”), a dispersion treatment was performed for 10 minutes at 50 ° C. and 100% output to obtain a colorant dispersion.
As a release agent, 20 g of carnauba wax (manufactured by Toyo Petrolide Co., Ltd.), 80 g of distilled water, and 0.2 g of an anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., “Neogen R”) are heated and mixed at 90 ° C. The mixture was stirred and mixed using a homogenizer ("ULTRA-TURRAX T25 digital" manufactured by IKA). Furthermore, it was dispersed using a high-pressure homogenizer (manufactured by MST Co., “LAB2000”) to obtain a release agent dispersion.
An anhydrous aluminum sulfate as a flocculant was dissolved in distilled water so as to have a concentration of 0.3% by mass to prepare a flocculant solution.

  98 g of these resin particle dispersions, 6 g of the colorant dispersion, 6 g of the release agent dispersion, and 60 g of distilled water were mixed. While stirring the obtained dispersion mixture at 5000 rpm using a homogenizer (“ULTRA-TURRAX T25 digital” manufactured by IKA), the homogenizer treatment was continued for 10 minutes. The mixing apparatus was changed to a stirrer using a three-one motor BL600, and the temperature of the mixture was stirred and maintained at 40 ° C. for 30 minutes, and a 0.4 mass% NaOH aqueous solution was dropped. Subsequently, the temperature was raised to 80 ° C., stirred for 1 hour, and then cooled. Thereafter, filtration was performed, and the obtained filtrate was dried by freeze drying to obtain a particulate toner.

<Examples 2-9, Comparative Examples 1-3>
In Examples 2 to 9 and Comparative Example 3, polyester resins and toners were produced in the same manner as in Example 1 according to the preparation compositions shown in Table 1, and various measurements and evaluations were performed. In Comparative Example 1, the temperature in the reaction system was heated to 230 ° C., this temperature was maintained, and the esterification reaction was performed until no water was distilled from the reaction system. Comparative Example 2 was charged into a stainless steel reaction vessel in which 1000 ppm of tetra-n-butoxytitanium with respect to the polyvalent carboxylic acid was heated to 70 ° C. into the polyhydric alcohol having the charge composition shown in Table 1. After stirring at 200 rpm for a minute, terephthalic acid was charged into a reaction vessel equipped with a distillation tower.
Next, the temperature was raised and heated so that the temperature in the reaction system became 270 ° C., this temperature was maintained, and the esterification reaction was carried out until no water was distilled from the reaction system. Next, the temperature in the reaction system was set to 245 ° C., trimellitic anhydride was added, the mixture was stirred and mixed at 200 rpm for 20 minutes, the inside of the reaction vessel was depressurized, and the condensation reaction was carried out while distilling the polyalcohol from the reaction system. .
After the inside of the apparatus is brought to atmospheric pressure with nitrogen during the condensation reaction, about 3 g of resin is sampled from the reaction vessel, the resin is cooled to room temperature, the softening temperature is measured, and sampling is performed until the softening temperature shown in Table 1 is reached. The polymerization was repeated repeatedly.

  As is clear from the results in Table 1, in each example, a polyester resin excellent in polymerization stability and emulsion stability could be produced. Further, from the polyester resin obtained in each example, a toner having excellent storage stability could be produced.

On the other hand, as is clear from the results in Table 1, in the case of Comparative Example 1 in which the polyester resin was produced at a reaction temperature of 230 ° C., the polymerization stability and emulsion stability of the polyester resin were low.
In the case of Comparative Example 2 in which a polyester resin was prepared by adding trimellitic anhydride, which is a trivalent or higher carboxylic acid, after the esterification reaction without preparing a slurry solution containing a trivalent or higher acid or / and alcohol. The emulsion stability of the polyester resin and the storage stability of the toner were inferior.
In the case of Comparative Example 3 in which the bisphenol A alkylene oxide adduct is a bisphenol A ethylene oxide adduct and the average addition mole number of the ethylene oxide adduct is 5.0 mol, the emulsion stability of the polyester resin is stabilized. And the storage stability of the toner were remarkably inferior.
When the ratio of the acid value (mgKOH / g) to the hydroxyl value (KOH / g) of the resin was Comparative Example 4 where the acid value / hydroxyl value <1.0, the emulsion stability of the polyester resin was inferior.

  According to the method for producing a polyester resin of the present invention, a toner having excellent storage stability can be obtained, and the method for producing a polyester resin having excellent pulverizability and emulsion stability and low residual monomer can be obtained by a pulverization method or a chemical method. It can be provided for both toner manufacturing methods.

Claims (6)

A method for producing a polyester resin having a step of polymerizing a slurry solution containing a polyhydric alcohol component containing a bisphenol A alkylene oxide adduct and a polyvalent carboxylic acid component at 240 ° C. or higher,
The slurry solution contains a trivalent or higher acid and / or alcohol,
A method for producing a polyester resin, wherein a ratio of an acid value (mgKOH / g) to a hydroxyl value (KOH / g) of the polyester resin satisfies an acid value / hydroxyl value ≧ 1.0. The method for producing a polyester resin according to claim 1, wherein the bisphenol A alkylene oxide adduct is a bisphenol A ethylene oxide adduct. The manufacturing method of the polyester resin of Claim 1 or 2 whose average addition mole number of the said alkylene oxide adduct is 2.2-4.0.   The manufacturing method as described in any one of Claims 1-3 which superposes | polymerizes at 240 degreeC or more, after mixing the said trivalent or more acid and / or alcohol with a bisphenol A ethylene oxide adduct.   The manufacturing method as described in any one of Claims 1-4 which superposes | polymerizes by further adding isosorbide.   A method for producing a toner, comprising a step of kneading a mixture containing the resin obtained by the production method according to claim 1.