JP2007333977A - Electrophotographic toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow efficient manufacture of a toner having a sharp particle size distribution and high circularity, and to provide such an electrophotographic toner obtained by a wet process, containing a polyester binder resin, and good in hydrolysis resistance and image quality. <P>SOLUTION: The toner is obtained through a step (I) of emulsifying raw material components including a polyester-containing binder resin in an aqueous medium and a step (II) of aggregating/uniting the resultant emulsified particles, wherein the polyester is obtained by condensation polymerization of an alcohol component and a carboxylic acid component in the presence of at least one titanium compound selected from the group consisting of titanium compounds represented by the formula: Ti(Z)<SB>4</SB>or Ti(X)<SB>n</SB>(Y)<SB>m</SB>, wherein Z, X and Y each denote an 8-28C alkoxy, alkenyloxy or acyloxy group, provided that four symbols Z may be the same or different. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrophotographic toner used in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and the like, and a method for producing the same.

In the field of toner for electrophotography, development of a small particle size toner excellent in fixability is desired from the pursuit of high image quality. There are two types of toner manufacturing methods: melt-kneading and pulverization methods and wet-type manufacturing methods such as emulsion aggregation methods. When toners using binder resins mainly composed of polyester are manufactured by melt-kneading and pulverization methods, it is difficult to control the pulverization. It is not practical.
On the other hand, the toner obtained by the wet manufacturing method includes, for example, toner particles composed of a resin and a colorant, and the toner particles disperse resin particles obtained by polyaddition reaction or polycondensation reaction in an aqueous medium. A toner for developing an electrostatic charge image obtained through a step of preparing a dispersion, a step of salting out / fusing the resin particles in the dispersion in an aqueous medium (see Patent Document 1), and a binder Electrons obtained by melt-kneading a toner material containing a resin and a colorant, dissolving / dispersing the binder resin in an organic solvent that can be melted or swelled, emulsifying and dispersing it in an aqueous medium, and then aggregating it. A photographic toner (see Patent Document 2) is disclosed.
Furthermore, from the viewpoint of image characteristics, a toner obtained by a wet manufacturing method containing polyester obtained by condensation polymerization in the presence of a titanium catalyst has been disclosed (see Patent Document 3 and Patent Document 4).

However, in the wet manufacturing method, since mechanical share is not added in the manufacturing process, it is generally more difficult to uniformly disperse the internal additive, and the image characteristics tend to be deteriorated. In particular, when a toner containing polyester as a binder resin is produced by a wet process, the ester bond of the polyester is hydrolyzed in the solution, and the resulting toner has a reduced glass transition point and deteriorates its storage stability and fixability. There are things to do.
In addition, when using a polyester produced in the presence of a titanium catalyst, the reaction time in the particle formation process tends to be longer during toner production, which is more susceptible to hydrolysis, and the reaction time is longer. The toner is susceptible to thermal history, and the resulting toner may have poor image performance.

JP 2004-271686 A JP 2002-296839 A JP 2005-62818 A JP 2006-91318 A

  The present invention is a toner containing a polyester-containing binder resin obtained by a wet manufacturing method, having a sharp particle size distribution, capable of being produced in a short aggregation and coalescence time, and having hydrolysis resistance and toner image performance. It is an object of the present invention to provide a good electrophotographic toner and a method for producing the same.

The present invention
(1) A step (I) of emulsifying a raw material component containing a binder resin containing polyester with an aqueous medium, and a step (II) of aggregating and coalescing the emulsified particles of the binder resin obtained in the above step A toner obtained by a process comprising the formula (1)
Ti (Z) ₄ (1)
(Wherein, Z represents an alkoxy group, an alkenyloxy group or an acyloxy group each having a total carbon number of 8 to 28, and the four Zs may be the same or different.)
And a titanium compound represented by the formula (2)
Ti (X) _n (Y) _m (2)
(Wherein X is an amino group having 1 to 28 carbon atoms, Y is an alkoxy group, alkenyloxy group or acyloxy group having a total carbon number of 1 to 28, and n and m are each 1 to 3 Represents an integer, and the sum of n and m is 4.) In the presence of at least one titanium compound selected from the group consisting of titanium compounds represented by the following formula, an alcohol component and a carboxylic acid component are subjected to polycondensation. An electrophotographic toner containing polyester obtained by

(2) Step (I) of emulsifying a raw material component containing a binder resin containing polyester in an aqueous medium, and step (II) of aggregating and coalescing the emulsified particles of the binder resin obtained in the step A method for producing a toner having the following formula: (1)
An electrophotography obtained by polycondensation of an alcohol component and a carboxylic acid component in the presence of at least one titanium compound selected from the group consisting of a titanium compound represented by formula (2) and a titanium compound represented by the above formula (2) And (3) an electrophotographic toner obtained by a method comprising a step of forming a raw material containing a binder resin into an aqueous medium, and (a) the above formula ( In the presence of at least one titanium compound selected from the group consisting of the titanium compound represented by 1) and the titanium compound represented by the above formula (2), and (ro) an amide compound and / or an amine compound, A process for producing a polyester for an electrophotographic toner, comprising a step of polycondensation of a silver component and a carboxylic acid component,
I will provide a.

  According to the present invention, a toner containing a polyester-containing binder resin obtained by a wet method has a sharp particle size distribution, can be produced in a short aggregation and coalescence time, and has hydrolysis resistance and a toner image. An electrophotographic toner having good performance can be provided.

The electrophotographic toner of the present invention includes a step (I) [emulsification step (I)] of emulsifying a raw material component containing a polyester-containing binder resin in an aqueous medium, and the binder resin obtained in the step. The toner is obtained by a method having the step (II) [aggregation / unification step (II)] of aggregating and coalescing the emulsified particles.
The electrophotographic toner of the present invention (hereinafter sometimes simply referred to as “toner”) will be described below.

[Binder resin containing polyester]
The binder resin contained in the toner of the present invention obtained through the emulsification step (I) and the aggregation / unification step (II) contains a polyester from the viewpoint of colorant dispersibility, fixability and durability. Is done. The content of the polyester is preferably 60% by weight or more, more preferably 70% by weight or more, and still more preferably 80% by weight or more from the viewpoints of fixability and durability in the binder resin. Examples of binder resins other than polyester include known resins used in toners, such as styrene-acrylic resins, epoxy resins, polycarbonates, and polyurethanes.

In the present invention, as the polyester, the formula (1)
Ti (Z) ₄ (1)
(In the formula, Z represents an alkoxy group, an alkenyloxy group or an acyloxy group having a total carbon number of 8 to 28, and the four Zs may be the same or different.)
And a titanium compound represented by the formula (2)
Ti (X) _n (Y) _m (2)
(Wherein X is an amino group having 1 to 28 carbon atoms, Y is an alkoxy group, alkenyloxy group or acyloxy group having a total carbon number of 1 to 28, and n and m are each 1 to 3 An integer and the sum of n and m is 4.) obtained by polycondensing an alcohol component and a carboxylic acid component in the presence of at least one titanium compound selected from the group consisting of titanium compounds represented by Is used.
In formula (1), each of the alkoxy group, alkenyloxy group or acyloxy group represented by Z and having a total carbon number of 8 to 28 may be either linear or branched. Alternatively, a group having an alicyclic group may be used, and among these, an alkoxy group is preferable from the viewpoint of catalytic activity. Moreover, the total carbon number of the group represented by Z is preferably 8 to 24, more preferably 8 to 20 from the viewpoint of catalytic activity and the stability of the reaction of the polycondensation reaction.
The group represented by Z may have a substituent such as a hydroxyl group or halogen,
From the viewpoint of catalytic activity, an unsubstituted one or one having a hydroxyl group as a substituent is preferred, and an unsubstituted one is more preferred.
The four Zs may be the same or different, but are preferably the same groups from the viewpoints of reaction activity and hydrolysis resistance of the resulting polyester.

Specific examples of the titanium compound represented by the formula (1) include tetrastearyl titanate [Ti (C ₁₈ H ₃₇ O) ₄ ], tetramyristyl titanate [Ti (C ₁₄ H ₂₉ O) ₄ ], tetraoctyl titanate. [Ti (C ₈ H ₁₇ O) ₄ ], dioctyl dihydroxyoctyl titanate [Ti (C ₈ H ₁₇ O) ₂ (OHC ₈ H ₁₆ O) ₂ ], dimyristyl dioctyl titanate [Ti (C ₁₄ H ₂₉ O) ₂ (C ₈ H ₁₇ O) ₂ ] and the like. Among these, tetrastearyl titanate, tetramyristyl titanate, tetraoctyl titanate or dioctyl dihydroxyoctyl titanate are preferred in view of the catalytic activity and the stability of the condensation polymerization reaction. Is preferred. These can be obtained, for example, by reacting titanium halides with the corresponding alcohols, but they can also be obtained as commercial products such as Nisso Corporation.
In the present invention, the titanium compound represented by the above formula (1) may be used alone or in combination of two or more.
In the present invention, the titanium compound represented by the formula (1) is based on 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component from the viewpoints of reaction activity, hydrolysis resistance of the resulting toner, image characteristics, and the like. , Preferably in a proportion of 0.01 to 2 parts by weight, more preferably in a proportion of 0.1 to 1 part by weight.

  In the formula (2), the total number of carbon atoms of the amino group represented by X is preferably 2 to 10, more preferably 4 to 8, more preferably 6 from the viewpoint of catalytic activity and the stability of the condensation polymerization reaction. preferable. The amino group in the present invention is a group having a nitrogen atom that can be directly bonded to a titanium atom, and a quaternary cation group is also included in the amino group, preferably a quaternary cation group. Such an amino group can be generated, for example, by reacting titanium halide with an amine compound. Examples of such amine compounds include alkanolamine compounds such as monoalkanolamine compounds, dialkanolamine compounds, trialkanolamine compounds, and trialkyls. Examples include alkylamine compounds such as amines, among which alkanolamines are preferred, and trialkanolamines are more preferred.

In the formula (2), the alkoxy group having 1 to 28 carbon atoms, the alkenyloxy group or the acyloxy group represented by Y may be linear or branched, or an alicyclic group. It may be a group. Further, the group represented by Y may have a substituent such as a hydroxyl group or halogen, but is preferably unsubstituted or substituted with a hydroxyl group as a substituent, and more preferably an unsubstituted group.
The total number of carbon atoms of the group represented by Y is preferably 1 to 6, more preferably 2 to 5, from the viewpoint of catalytic activity and the stability of the condensation polymerization reaction. Furthermore, from the viewpoint of the effect of the present invention, the group represented by X preferably has a larger total carbon number than the group represented by Y, and the difference in the total carbon number is preferably 1 to 6, more preferably Is 2-4.
When there are a plurality of Xs, the plurality of Xs may be the same or different, and when there are a plurality of Ys, the plurality of Ys may be the same or different.

Specific examples of the titanium compound represented by the formula (2) include titanium diisopropylate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₃ H ₇ O) ₂ ], titanium diisopropylate. Bisdiethanolaminate [Ti (C ₄ H ₁₀ O ₂ N) ₂ (C ₃ H ₇ O) ₂ ], Titanium dipentylate bistriethanolaminate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₅ H ₁₁ O) ₂ ], titanium diethylate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₂ H ₅ O) ₂ ], titanium dihydroxyoctylate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (OHC ₈ H ₁₆ O) ₂ ], titanium distearate bistriethanolamate [Ti (C ₆ H ₁₄ O ₃ N) ₂ (C ₁₈ H ₃₇ O) ₂ ], titanium triisopropylate tri Ethanolamineate [Ti ( C ₆ H ₁₄ O ₃ N) ₁ (C ₃ H ₇ O) ₃ ], titanium monopropylate tris (triethanolaminate) [Ti (C ₆ H ₁₄ O ₃ N) ₃ (C ₃ H ₇ O) ₁ Among these, titanium diisopropylate bistriethanolamate, titanium diisopropylate bisdiethanolamate, and titanium dipentylate bistriethanolamin can be used from the viewpoint of catalytic activity and stability of the polycondensation reaction. Nate is preferable, and these are also available as, for example, commercial products of Matsumoto Trading Co., Ltd.

In this invention, the titanium compound represented by this Formula (2) may be used individually by 1 type, and may be used in combination of 2 or more type.
The titanium compound represented by the formula (2) is 0.01 to 2 with respect to 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component from the viewpoints of reaction activity, hydrolysis resistance of the obtained toner and image characteristics. It can be made to exist in the ratio of a weight part, and it is preferable to make it exist in the ratio of 0.1-1 weight part.
In the present invention, when the titanium compound represented by the above formula (1) and the titanium compound represented by the formula (2) are used in combination, the total amount is the same as when each of the above titanium compounds is used alone. Can be used.

In the present invention, it is possible to obtain a polyester by polycondensation of an alcohol component and a carboxylic acid component in the presence of an amide compound and / or an amine compound together with the titanium compound. From the viewpoint of the stability of the reaction.
Examples of the amide compound include fatty acid amides and aromatic amides. Among these, fatty acid amides are preferable from the viewpoint of affinity with the catalyst.
The fatty acid amide is preferably an alkylene bis fatty acid amide from the viewpoint of compatibility with the polyester. From the same viewpoint, the number of carbon atoms of the alkylene group of the alkylene bis fatty acid amide is preferably 2-8, more preferably 2-6. Moreover, 6-30 are preferable and, as for carbon number of the fatty acid group in fatty acid amide, 8-24 are more preferable.
Suitable fatty acid amides in the present invention include stearic acid amide, oleic acid amide, methacrylic acid amide, nicotinic acid amide, n-butyric acid amide, isobutyric acid amide, propionamide, ethylenebisstearic acid amide, hexamethylenebislauric acid amide. , Ethylene bislauric acid amide, hexamethylene bis stearic acid amide, N, N-ethylene bis octadamide and the like, and stearic acid amide is more preferable from the viewpoint of high thermal stability.

The melting point of the amide compound is preferably 70 to 200 ° C., more preferably 90 to 180 ° C., from the viewpoint of the fluidity of the toner.
The molecular weight of the amide compound is preferably from 100 to 5000, more preferably from 150 to 1000, and even more preferably from 200 to 600, from the viewpoint of affinity with the catalyst. When the amide compound is a polymer such as polyamide, the molecular weight is a number average molecular weight measured by gel permeation chromatography.
This amide compound may be used alone or in combination of two or more, and the abundance thereof is determined from the alcohol component from the viewpoint of hydrolysis resistance of the resulting polyester. 0.005 to 2 parts by weight is preferable and 0.1 to 1 part by weight is more preferable with respect to 100 parts by weight of the total amount of the carboxylic acid component.

Examples of the amine compound include an alkylamine compound and an alcoholamine compound. Among these, an alkylamine compound is preferable from the viewpoint of hydrolysis resistance and affinity with a catalyst.
Examples of alkylamine compounds include ethylamine, diethylamine, triethylamine, 2-ethylhexylamine, di-2-ethylhexylamine, di-n-octylamine, 3- (dibutylamino) propylamine, tetramethylethylenediamine, and tri-n-octylamine. , T-butylamine, isopropylamine, 3,3′-iminobis (propylamine), 3- (2-ethylhexyloxy) propylamine, 3-ethoxypropylamine, diisobutylamine, 3- (diethylamino) propylamine, propylamine, 3- (methylamino) propylamine, 3- (dimethylamino) propylamine, N-methyl-3,3′-iminobis (propylamine), 3-methoxypropylamine, ethylenediamine, diethylenetriamine, triethyl Tetramine, tetraethylenepentamine, pentaethylenehexamine, N, N-diethylethylenediamine, N, N, N ′, N′-tetraethylethylenediamine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, N, N′-diisopropylethylenediamine, N-phenylethylenediamine, N-propylethylenediamine, N-methylethylenediamine, ethylenediaminetetraacetic acid, ethylenediaminediacetate, ethylenediaminetetraacetic acid dicalcium, ethylenediaminetetraacetic acid disodium dihydrogen dihydrate, Examples include amines such as ethylenediaminetetraacetic acid tripotassium dihydrate, tetraacetylethylenediamine, and amine derivatives. Among these, alkylamines having 2 to 8 carbon atoms from the viewpoint of affinity with metal catalysts. Compound is preferably an alkyl diamine compound having two carbon atoms, such as ethylenediaminetetraacetic acid is more preferable.

As the alcohol amine compound, an alcohol amine compound having 2 to 8 carbon atoms is preferable from the viewpoint of affinity with a metal catalyst, and ethanolamine, diethanolamine, triethanolamine, propanolamine, butanolamine and the like are more preferably used. Are more preferred. As ethanolamines, ethanolamine, diethanolamine and triethanolamine are preferable, and triethanolamine is more preferable from the viewpoint of stability of the compound.
This amine compound may be used individually by 1 type, and may be used in combination of 2 or more type. In addition, from the viewpoint of hydrolysis resistance of the resulting polyester, the abundance thereof is preferably 0.005 to 2 parts by weight, preferably 0.1 to 1 part by weight with respect to 100 parts by weight of the total amount of alcohol component and carboxylic acid component. Part is more preferred. In addition, what has titanium is not included in the said amine compound in this invention.
In the present invention, the amide compound and / or amine compound may be used together with the titanium compound represented by the formula (1), but from the viewpoint of compatibility with the polyester, an amine compound is used. preferable. When an amide compound and an amine compound are used in combination, the total abundance is the same as the amount when each is used alone.

In the present invention, when the titanium compound and the amide compound and / or amine compound are used in combination, and in the presence of these, a polyester is obtained by condensation polymerization of an alcohol component and a carboxylic acid component, the reaction activity and From the viewpoint of hydrolysis resistance and image characteristics of the toner obtained, the titanium compound represented by the formula (1) and / or the formula (2) is represented with respect to 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component. The abundance of the titanium compound is preferably 0.01 to 2 parts by weight, and more preferably 0.1 to 1 part by weight. On the other hand, the abundance of the amide compound and / or amine compound is preferably 0.005 to 2 parts by weight, and more preferably 0.1 to 1 part by weight.
The weight ratio of the amide compound and / or amine compound to the titanium compound [(amide compound and / or amine compound) / titanium compound] is determined from the viewpoint of charge stability of the toner obtained, that is, image characteristics and reaction activity. 0.1-20 are preferable, 0.5-10 are more preferable, and 0.5-5 are still more preferable.

In the present invention, a dihydric or higher polyhydric alcohol is used as the alcohol component used as a raw material for the polyester. Examples of the dihydric alcohol include alkylenes of bisphenol A such as polyoxypropylene-2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene-2,2-bis (4-hydroxyphenyl) propane (carbon number of 2 4) Oxide adduct (average added mole number 1.5 to 6), ethylene glycol, propylene glycol, neopentyl glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, etc. It is done.
Examples of the trihydric or higher polyhydric alcohol include sorbitol, pentaerythritol, glycerol, trimethylolpropane and the like.
Since the polyester having a bisphenol A skeleton is preferable from the viewpoint of chargeability and durability, among the polyhydric alcohols, an alcohol having a bisphenol A skeleton such as an alkylene oxide adduct of bisphenol A is preferable. The content of the alcohol having a bisphenol A skeleton is preferably 10 to 100 mol%, more preferably 50 to 100 mol%, and particularly preferably 100 mol% in the alcohol component.

On the other hand, a divalent or higher polyvalent carboxylic acid compound is used as the carboxylic acid component. Examples of divalent carboxylic acid compounds include aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, and isophthalic acid, and aliphatic dicarboxylic acids such as sebacic acid, fumaric acid, maleic acid, adipic acid, azelaic acid, dodecenyl succinic acid, and dodecyl succinic acid. Examples include acids, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, anhydrides of these acids, and alkyl (C1 to C3) esters.
Examples of the trivalent or higher polyvalent carboxylic acid compounds include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, and aromatic carboxylic acids such as pyromellitic acid, and these Derivatives such as acid anhydrides and alkyl (C 1 -C 3) esters are listed.
In addition, from the viewpoint of charging properties, carboxylic acid components include aromatic carboxylic acids such as terephthalic acid, trimellitic acid, isophthalic acid, and anhydrides thereof, fumaric acid, adipic acid, succinic acid, and derivatives thereof, anhydrous It is preferable to use a polyester obtained by using an aliphatic carboxylic acid such as a product together.

In the polyester, the alcohol component and the carboxylic acid component described above are heated in the presence of the titanium compound, preferably the amide compound and / or the amine compound, for example, at a temperature of about 180 to 250 ° C. in an inert gas atmosphere. Thus, it can be produced by condensation polymerization under reduced pressure as required.
In addition, when manufacturing polyester, conventionally well-known organic tin compounds, inorganic tin compounds, etc., such as a dibutyltin oxide and a dioctylic acid tin, can be used together suitably with the said titanium compound.
In the present invention, polyester includes not only polyester but also polyester modified to such an extent that its properties are not substantially impaired. Examples of the modified polyester include grafting and blocking with phenol, urethane, epoxy and the like by the methods described in JP-A-11-133668, JP-A-10-239903, and JP-A-8-20636. Polyester.

In the present invention, from the viewpoint of storage stability of the toner, the softening point of the polyester is preferably 80 to 165 ° C, more preferably 85 to 150 ° C, and the glass transition point is preferably 50 to 85 ° C, more preferably 50. ~ 70 ° C. The acid value is preferably 6 to 35 mgKOH / g, more preferably 10 to 35 mgKOH / g, and still more preferably 15 to 35 mgKOH / g, from the viewpoint of manufacturability during emulsification. The desired softening point and acid value can be obtained by adjusting the raw material monomer composition of reaction conditions such as the temperature of condensation polymerization and reaction time. In the case where the binder resin contains a plurality of polyesters or other binder resins, the softening point, glass transition point and acid value of the binder resin are the softening point, glass as a mixture of the binder resins. It means transition point and acid value.
Further, from the viewpoint of the durability of the toner, the polyester average molecular weight is preferably 1,000 to 10,000 in terms of number average molecular weight, and more preferably 2,000 to 8,000. The weight average molecular weight is preferably 10,000 to 600,000, more preferably 10,000 to 300,000.

The toner of the present invention is obtained in steps (I) [emulsification step (I)] of emulsifying a raw material component containing a polyester-containing binder resin obtained as described above in an aqueous medium. Further, the toner is obtained by a method having a step (II) of aggregating and coalescing the emulsified particles of the binder resin [aggregation and coalescence step (II)].
Hereinafter, the emulsification step (I) and the aggregation / unification step (II) will be described.

[Emulsification step (I)]
In the emulsification step, first, a dispersion of raw material components containing a binder resin containing polyester is prepared. For the preparation of this dispersion, an aqueous medium is used, and specifically, a basic aqueous medium can be used.
The basic aqueous medium refers to an aqueous medium containing a 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 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.
The content of the basic compound in the basic aqueous medium depends on the type of the basic compound used, but is usually 1 to 30% by weight, preferably 3 to 20% from the viewpoint of suppressing hydrolysis of the binder resin. %, More preferably 5 to 10% by weight.

  The aqueous medium contains water as a main component, and from the viewpoint of environmental conservation, the water content is preferably 80% by weight or more, more preferably 90% by weight or more, and even more preferably 100% by weight in the aqueous medium. . In the present invention, the binder resin can be dispersed by using only water without substantially using an organic solvent. Examples of components other than water include organic solvents that dissolve in water, such as methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. Among these, alcohol-based organic solvents such as methanol, ethanol, isopropanol, butanol and the like, which are organic solvents that do not dissolve the resin, are preferable from the viewpoint of preventing mixing into the toner.

  In the preparation of the dispersion, the amount of the aqueous medium used is preferably 5 to 100 parts by weight with respect to 100 parts by weight of the binder resin from the viewpoint that a uniform resin emulsion can be effectively prepared. -90 weight part is more preferable, and 20-80 weight part is further more preferable.

  In the present invention, a surfactant can be added during the dispersion treatment. The addition amount is preferably 20 parts by weight or less, more preferably less than 100 parts by weight with respect to 100 parts by weight of the resin for the purpose of suppressing foaming during the dispersion treatment and improving the emulsion stability of the finally obtained resin emulsion. Is 15 parts by weight or less, more preferably 0.5 to 10 parts by weight. Examples of the surfactant include anionic surfactants such as sodium dodecylbenzenesulfonate, sodium octadecyl sulfate, sodium oleate, sodium laurate, and potassium stearate; laurylamine acetate, stearylamine acetate, lauryltrimethylammonium chloride, and the like. Cationic surfactants; amphoteric surfactants such as lauryl dimethylamine oxide; nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, sorbitan monostearate, and polyoxyethylene alkylamine. 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 preparation of the dispersion, a colorant is added to the binder resin, and additives such as a release agent and a charge control agent are added as necessary, and the mixture can be dispersed.
The colorant is not particularly limited, and any known colorant can be used and can be appropriately selected. Specifically, carbon black, inorganic composite oxide, chrome yellow, hansa yellow, benzidine yellow, sren yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliantamine 3B, Brilliantamine 6B, Dupont Oil Red, Pyrazolone Red, Resol Red, Rhodamine B Lake, Lake Red C, Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Phthalocyanine Green, Malachite Green Oxalate, etc. Various pigments, acridine, xanthene, azo, benzoquinone, azine, anthraquinone, indico, thioi Zico system, phthalocyanine, aniline black, can be used alone or in combination of two or more kinds of various dyes of thiazole, and the like.
The use ratio of the binder resin and the colorant is preferably 70:30 to 97: 3, and more preferably 80:20 to 97: 3, in terms of weight ratio, from the viewpoints of toner chargeability, durability, print density, and the like. .

Specific examples of the release agent include low molecular weight polyolefins such as polyethylene, polypropylene and polybutene; silicones having a softening point by heating; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide and stearic acid amide Plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; minerals such as montan wax, ozokerite, ceresin wax, microcrystalline wax, Fischer-Tropsch wax・ Petroleum-based wax.
The content of the release agent is 100% by weight with respect to 100 parts by weight of the binder resin or, when a colorant is used, in consideration of the addition effect and the adverse effect on the chargeability, and the total amount of binder resin and colorant is 100. The amount is usually about 1 to 20 parts by weight, preferably 2 to 15 parts by weight with respect to parts by weight.

Examples of charge control agents include benzoic acid metal salts, salicylic acid metal salts, alkyl salicylic acid metal salts, catechol metal salts, metal-containing bisazo dyes, tetraphenylborate derivatives, quaternary ammonium salts, alkylpyridinium salts, and the like. Can be mentioned. These may be used individually by 1 type and may be used in combination of 2 or more type.
The content of the charge control agent is usually 10 parts by weight or less, preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the total amount of the binder resin and the colorant.

In the preparation of the dispersion, from the viewpoint of uniformly dispersing the resin particles or a mixture of resin particles and various additives such as a colorant used as necessary, at a temperature below the softening point of the resin particles. It is preferable to perform a dispersion process. By performing a dispersion treatment at a temperature lower than the softening point of the resin particles, preferably 50 ° C. lower than the softening point (hereinafter referred to as “softening point−50 ° C.”), the fusion between the resin particles is suppressed, A uniform resin dispersion can be prepared. Further, the lower limit temperature of the dispersion treatment is preferably higher than 0 ° C., more preferably 10 ° C. or higher, from the viewpoint of fluidity of the medium and production energy of the resin emulsion. When using a mixed resin, the softening point of the mixed resin mixed and melted at the mixing ratio is defined as the softening point of the binder resin. Moreover, when using a masterbatch, it is set as the softening point of mixed resin including the resin used for it.
Specifically, in an aqueous medium containing a surfactant or the like, for example, a binder resin particle containing polyester is stirred with a colorant or the like at a temperature below the softening point of the resin particle, for example, at a temperature of about 10 to 50 ° C. A uniform resin dispersion can be prepared by a method such as dispersion treatment.

Next, the resin dispersion dispersed as described above is substantially neutralized by stirring for a certain time at a temperature not lower than the glass transition point and not higher than the softening point of the resin. From the viewpoint of uniformly neutralizing the resin, the stirring time is preferably 30 minutes or longer, more preferably 1 hour or longer.
By performing the neutralization at a temperature within the above range, the neutralization is sufficiently performed, the formation of large emulsified particles is suppressed in the subsequent emulsification treatment, and no special apparatus is required for heating. In this respect, the neutralization temperature is preferably a glass transition point of the resin + 10 ° C or higher, and is preferably a softening point of -5 ° C or lower.

Next, it is preferable to add an aqueous liquid to the dispersion neutralized as described above at a temperature not lower than the glass transition point and not higher than the softening point of the resin to emulsify the resin in an aqueous medium.
In this emulsification step, from the viewpoint of preparing a fine resin emulsion, the resin dispersion neutralized as described above is maintained at a temperature above the glass transition point and below the softening point of the resin and stirred. However, it is preferable to add an aqueous liquid thereto and emulsify in an aqueous medium.
In addition, by performing the emulsification at a temperature within the above range, the emulsification is performed smoothly and no special apparatus is required for heating. From this, the temperature at the time of emulsification is preferably a temperature of glass transition point + 10 ° C. or higher, and a temperature of softening point −5 ° C. or lower is preferable.

In this emulsification step, the resin content in the dispersion is preferably about 50 to 90% by weight, more preferably 50 to 80% by weight, from the viewpoint of easy phase inversion immediately before the start of emulsification. Here, “immediately before the start of emulsification” refers to a point in time when the viscosity of the system becomes the highest in all the steps. Therefore, by attaching a torque meter or the like to the stirrer, the point in time can be easily known.
The emulsification start time can be arbitrarily adjusted depending on the acid value and the degree of neutralization of the resin used. For example, when the acid value of the resin is increased or the degree of neutralization is increased, the hydrophilicity of the resin is increased, and emulsification can be started by contacting with a small amount of an aqueous medium.

Examples of the aqueous liquid used for emulsification include the same ones as described in the description of the aqueous medium. The addition rate of the aqueous liquid is preferably 0.5 to 50 g / min, more preferably 0.5 to 30 g / min, and further preferably 1 to 20 g per 100 g of resin from the viewpoint that emulsification can be effectively carried out. / Min. In general, the addition rate may be maintained until the O / W type emulsion is substantially formed, and the addition rate of the aqueous liquid after the formation of the O / W type emulsion is not particularly limited.
The solid content concentration of the resin emulsion thus obtained is preferably 7 to 50% by weight from the viewpoint of the stability of the emulsion and the handleability of the resin emulsion in the subsequent aggregation step. -45 wt% is more preferable, and 10-40 wt% is more preferable.
The volume median particle size (D ₅₀ ) of the resin emulsified particles is preferably 0.02 to 2 μm, more preferably 0.05 to 1 μm, and still more preferably 0 in order to perform uniform aggregation in the aggregation process. 0.05 to 0.6 μm. In the present specification, the volume-median particle size (D ₅₀ ) means a particle size at which the cumulative volume frequency calculated by the volume fraction is 50% when calculated from the smaller particle size. The measuring method is as described later.

[Aggregation / Joint Process (II)]
Next, the emulsified particles in the resin emulsion thus obtained are agglomerated in the presence of a colorant and further coalesced (hereinafter referred to as agglomeration / coalescence step), whereby the electrophotographic image of the present invention. Toner is obtained. When the colorant is used, the colorant may be contained in the resin emulsion, or a dispersion of the colorant may be mixed with the resin emulsion to aggregate and coalesce. In addition, this step is preferably performed in the presence of a surfactant for the purpose of controlling the aggregation speed and the toner shape. When a surfactant is added in the step (I), it may not be added further, but may be added as necessary.
In the coagulation step, the pH value in the system is preferably 2 to 10, more preferably 2 to 9, from the viewpoint of achieving both the dispersion stability of the mixed solution and the cohesiveness of fine particles such as the binder resin and the colorant. 3 to 8 are more preferable.
From the same viewpoint, the temperature in the system in the aggregation process is preferably a softening point of the binder resin of −50 ° C. or higher (meaning a temperature of 50 ° C. lower than the softening point, the same applies hereinafter), and a softening point of −10 ° C. or lower. A point of −30 ° C. or higher and a softening point of −10 ° C. or lower are more preferable.

When the primary particles are aggregated, not only the primary particles obtained in the emulsification step (I) are aggregated (homo-aggregation), but the resin fine particles obtained separately in the same manner as in the emulsification step (I) A dispersion liquid or the like may be mixed with a dispersion liquid of primary particles to aggregate the primary particles and other resin fine particles (heteroaggregation).
In the aggregation step, it is preferable to add an aggregating agent in order to effectively perform aggregation. As the aggregating agent, a quaternary salt cationic surfactant, an organic aggregating agent such as polyethyleneimine, an inorganic aggregating agent such as an inorganic metal salt, an ammonium salt or a divalent or higher metal complex is used. Examples of inorganic metal salts include metal salts such as sodium sulfate, sodium chloride, calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, aluminum sulfate, polyaluminum chloride, polyaluminum hydroxide, Examples thereof include inorganic metal salt polymers such as calcium sulfide. Examples of ammonium salts include ammonium halide, ammonium sulfate, ammonium acetate, ammonium benzoate, and ammonium salicylate. Examples of quaternary ammonium salts include tetraalkylammonium halides.

The amount of the flocculant used is preferably 30 parts by weight or less, more preferably 0.01 to 20 parts by weight, and more preferably 0.1 to 100 parts by weight with respect to 100 parts by weight of the binder resin, from the viewpoint of the aggregation ability and the environmental resistance characteristics of the toner. More preferred is 10 parts by weight.
The flocculant is preferably added after being dissolved in an aqueous liquid, and it is preferable to sufficiently stir at the time of adding the flocculant and after the addition. The obtained aggregated particles are subjected to a step of coalescing the aggregated particles.
In the present invention, since a polyester obtained by condensation polymerization in the presence of a specific titanium compound is used, aggregation proceeds in a short time, and a toner having a higher degree of circularity than a conventional toner can be obtained efficiently. . This effect can be remarkably obtained when the polyester is subjected to a polycondensation reaction in the presence of an amide compound and / or an amine compound. This is presumably because the amide compound and / or amine compound in the polyester serves as a flocculant.
From the viewpoint of image characteristics, the circularity of the toner is preferably 0.960 to 0.999, and more preferably 0.965 to 0.999.

In the coalescence process, the temperature in the system is preferably equal to or higher than the temperature in the system in the aggregation process, but the target toner particle size, particle size distribution, shape control, and particle fusing property In view of the above, the softening point of the binder resin is preferably −50 ° C. or higher and the softening point + 10 ° C. or lower, more preferably softening point −40 ° C. or higher and softening point + 10 ° C. or lower, softening point −30 ° C. or higher, softening point + 10 ° C. The following is more preferable. The stirring speed is preferably a speed at which the aggregated particles do not settle.
The coalescence step can be performed simultaneously with the aggregation step, for example, by continuously raising the temperature or by raising the temperature to a temperature at which aggregation and coalescence can be performed and then continuing stirring at that temperature.
Since the electrophotographic toner of the present invention can shorten the reaction time required for the aggregation and coalescence, it is less susceptible to hydrolysis and thermal history, and has excellent hydrolysis resistance and toner image characteristics.

Toner mother particles can be obtained by subjecting the obtained coalesced particles to a solid-liquid separation process such as filtration, a washing process, and a drying process as appropriate.
In the washing step, an acid is preferably used to remove metal ions on the surface of the toner base particles in order to ensure sufficient charging characteristics and reliability as a toner, and washing is preferably performed a plurality of times.
In the drying step, any method such as a vibration type fluidized drying method, a spray drying method, a freeze drying method, a flash jet method, or the like can be employed. The water content after drying of the toner base particles is preferably adjusted to 1.5% by weight or less, more preferably 1.0% by weight or less, from the viewpoint of chargeability.

[Electrophotographic toner]
The electrophotographic toner of the present invention contains coalesced particles obtained as described above, and the content of the coalesced particles in the toner is 95 to 95 from the viewpoint of toner chargeability and fixability. It is preferably 100% by weight, and more preferably 96.5 to 99% by weight.
Further, from the viewpoints of high image quality and productivity, the volume median particle size (D ₅₀ ) of the toner particles is preferably 1 to 10 μm, more preferably 2 to 8 μm, and further preferably 3 to 7 μm. From the same viewpoint, the particle size distribution is preferably 25% or less, more preferably 20% or less, and still more preferably 18% or less in terms of CV value (standard deviation of particle size distribution / volume median particle size (D ₅₀ ) × 100). . Here, the particle size distribution can be specifically measured by a method described later using a laser diffraction type particle size measuring instrument or the like.
The softening point of the toner is preferably 60 to 140 ° C., more preferably 70 to 130 ° C., and still more preferably 80 to 130 ° C. from the viewpoint of low-temperature fixability.

In the toner of the present invention, an auxiliary agent such as a fluidizing agent can be added to the surface of the toner base particles as an external additive. External additives include known fine particles such as silica fine particles, titanium fine particles, alumina fine particles, cerium oxide fine particles, carbon black and other inorganic fine particles, and polymer fine particles such as polycarbonate, polymethyl methacrylate and silicone resin. Can be used.
The amount of the external additive is preferably 1 to 5 parts by weight and more preferably 1.5 to 3.5 parts by weight with respect to 100 parts by weight of the toner particles before the treatment with the external additive. However, when hydrophobic silica is used as an external additive, it is preferable to use 0.5 to 3 parts by weight of hydrophobic silica with respect to 100 parts by weight of toner particles before treatment with the external additive.

The toner of the present invention contains a binder resin including a polyester obtained by condensation polymerization in the presence of a specific titanium compound, and the polyester has excellent hydrolysis resistance, thereby suppressing a decrease in glass transition point. The image characteristics are excellent. Although the detailed reason is not clear, since the polyester used in the present invention can shorten the formation time of toner particles, one of the reasons is that it is difficult to undergo hydrolysis and the proportion of heat history due to reaction heat is reduced. It is thought to be the cause. Further, when a polyester polycondensation reaction is performed in the presence of an amide compound and / or an amine compound, the aggregation time can be shortened, and a toner having high circularity can be efficiently formed. This is presumably because the amide compound and / or amine compound in the polyester serves as a flocculant.
The toner for electrophotography obtained by the present invention can be used as a one-component developer or as a two-component developer by mixing with a carrier.

[Method for producing toner for electrophotography]
The present invention is also used in the manufacture of an electrophotographic toner obtained by a method including a step of forming a raw material containing a binder resin into an aqueous medium, and (a) Formula (1)
Ti (Z) ₄ (1)
(Wherein, Z represents an alkoxy group, an alkenyloxy group or an acyloxy group each having a total carbon number of 8 to 28, and the four Zs may be the same or different.)
And a titanium compound represented by the formula (2)
Ti (X) _n (Y) _m (2)
(Wherein X is an amino group having 1 to 28 carbon atoms, Y is an alkoxy group, alkenyloxy group or acyloxy group having a total carbon number of 1 to 28, and n and m are each 1 to 3 An integer, and the sum of n and m is 4.) In the presence of at least one titanium compound selected from the group consisting of titanium compounds represented by: (b) an amide compound and / or an amine compound, A process for producing a polyester for an electrophotographic toner, comprising a step of polycondensation of a carboxylic acid component and a carboxylic acid component, and a step of emulsifying a raw material component containing a binder resin containing polyester in an aqueous medium ( I) and a method for producing a toner comprising the step (II) of aggregating the emulsified particles of the binder resin obtained in the step, wherein the polyester is a titanium compound represented by the formula (1) And (2)
Ti (X) _n (Y) _m (2)
(Wherein X is an amino group having 1 to 28 carbon atoms, Y is an alkoxy group, alkenyloxy group or acyloxy group having a total carbon number of 1 to 28, and n and m are each 1 to 3 An integer and the sum of n and m is 4.) In the presence of at least one titanium compound selected from the group consisting of titanium compounds represented by the following formula: Provided is a method for producing the obtained electrophotographic toner.

In the polyester production method and toner production method of the present invention, the polyester is at least one titanium compound selected from the group consisting of a titanium compound represented by the formula (1) and a titanium compound represented by the formula (2). The method for obtaining the condensation polymerization of the alcohol component and the carboxylic acid component in the presence of is as described in the above description of the binder resin or toner containing the polyester of the present invention.
Further, Step (I) and Step (II) are as described in the description of the toner of the present invention.

Each property value was measured and evaluated by the following method.
[Acid value of resin]
Measured according to JIS K0070. However, the measurement solvent was a mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

[Softening point and glass transition point of resin]
(1) Softening point Using a flow tester (Shimadzu Corporation, “CFT-500D”), a 1 g sample was heated at a heating rate of 6 ° C./min, a load of 1.96 MPa was applied by a plunger, a diameter of 1 mm, Extrude from a 1 mm long nozzle. Plot the flow tester drop by the flow tester against the temperature, and let the softening point be the temperature at which half the sample flowed out.
(2) Glass transition point The temperature was raised to 200 ° C. using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., DSC210), and the sample was cooled from that temperature to 0 ° C. at a temperature lowering rate of 10 ° C./min. Measured in ° C / min. When a peak is observed at a temperature 20 ° C. or more lower than the softening point, the peak temperature is measured. When a peak is not observed at a temperature 20 ° C. or higher lower than the softening point, a step is observed. The temperature at the intersection of the tangent line indicating the maximum slope of the curve and the extension line of the base line on the high temperature side of the step is read as the glass transition point. The glass transition point is a physical property peculiar to the amorphous part of the resin, and is generally observed in amorphous polyester, but is observed when amorphous part exists even in crystalline polyester. There is.

[Weight average molecular weight of resin]
The molecular weight distribution is measured by gel permeation chromatography and the weight average molecular weight Mw is calculated by the following method.
(1) Preparation of sample solution Binder resin or toner is dissolved in chloroform so that the concentration is 0.5 g / 100 ml. Subsequently, this solution is filtered using a fluororesin filter having a pore size of 2 μm [manufactured by Sumitomo Electric Industries, Ltd., “FP-200”] to remove insoluble components to obtain a sample solution.
(2) Molecular weight distribution measurement Using the following apparatus, chloroform is flowed at a flow rate of 1 ml per minute, and the column is stabilized in a constant temperature bath at 40 ° C. 100 μl of the sample solution is injected therein and measurement is performed. The molecular weight of the sample is calculated based on a calibration curve prepared in advance. In this calibration curve, several types of monodisperse polystyrene (2.63 × 10 ³ , 2.06 × 10 ⁷ , 1.02 × 10 ⁵ , manufactured by Tosoh Corporation), 2.10 × manufactured by GL Sciences Inc. 10 ³ , 7.00 × 10 ³ , 5.04 × 10 ⁴ ) are used as standard samples.
Measuring device: CO-8010 (manufactured by Tosoh Corporation)
Analysis column: GMHLX + G3000HXL (manufactured by Tosoh Corporation)

[Particle size of resin emulsified particles]
(1) Measuring device: Laser diffraction type particle size measuring machine (LA-920, manufactured by HORIBA, Ltd.)
(2) Measurement conditions: Distilled water is added to the measurement cell, and the volume-median particle size (D ₅₀ ) is measured at a temperature at which the absorbance is in an appropriate range.
[Particle size and particle size distribution of toner and colored resin fine particle powder]
Measuring machine: Coulter Multisizer II (Beckman Coulter, Inc.)
Aperture diameter: 50 μm
Analysis software: Coulter Multisizer AccuComp version 1.19 (Beckman Coulter, Inc.)
Electrolyte: Isoton II (Beckman Coulter, Inc.)
Dispersion: Emulgen 109P (manufactured by Kao Corporation, polyoxyethylene lauryl ether, HLB: 13.6) is dissolved in the electrolytic solution to a concentration of 5% by weight to obtain a dispersion.
Dispersion condition: 10 mg of a measurement sample is added to 5 mL of the dispersion, and dispersed for 1 minute with an ultrasonic disperser. Then, 25 mL of electrolyte is added, and further dispersed for 1 minute with an ultrasonic disperser. A dispersion is prepared.
Measurement conditions: By adding the sample dispersion to 100 mL of the electrolytic solution, the particle size of 30,000 particles is adjusted to a concentration that can be measured in 20 seconds, and then 30,000 particles are measured and the particle size distribution is determined. Measure and determine the volume median particle size (D ₅₀ ) from this. The particle size distribution of the toner is indicated by a CV value (standard deviation of particle size distribution / volume median particle size (D ₅₀ ) × 100).

[Toner circularity]
(1) Preparation of dispersion: The same procedure as the preparation of the dispersion in the column of [Toner particle size] is performed.
(2) Measuring apparatus: FPIA-3000 (manufactured by Simex)
(3) Measurement conditions: A particle sheath was used as the measurement sheath liquid, and the average circularity was determined by repeating the measurement five times in the HPF measurement mode.

Production Examples 1 and 2 (Production of Resins A and B)
A polyester raw material monomer excluding trimellitic anhydride shown in Table 1, an esterification catalyst, and a co-catalyst were added to a 5-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a flow-down condenser, and a nitrogen introduction tube. The mixture was then reacted in a mantle heater in a nitrogen atmosphere at 230 ° C. and normal pressure (101.3 kPa) for 7 hours, and further reacted at 8.0 kPa for 1 hour. Thereafter, the mixture was cooled to 210 ° C. and trimellitic anhydride shown in Table 1 was added and reacted at normal pressure for 1 hour, and then reacted at 8.0 kPa until a desired softening point was obtained. Each B was obtained. Table 1 shows the properties of each resin.

Comparative Production Example 1 (Production of Resin C)
A polyester resin C was obtained in the same manner as in Production Example 1 except that the titanium compound catalyst was replaced with dibutyltin oxide. The properties are shown in Table 1.

Production Examples 3 and 4 (Production of Resins D and E)
The raw material monomer of polyester excluding fumaric acid shown in Table 1, the esterification catalyst, and the cocatalyst were placed in a 5-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a flow-down condenser, and a nitrogen inlet tube. The reaction was carried out in a mantle heater under a nitrogen atmosphere at 230 ° C. and normal pressure (101.3 kPa) for 5 hours, and further at 8.0 kPa for 1 hour. Thereafter, it is cooled to 185 ° C., fumaric acid and hydroquinone shown in Table 1 are added, heated to 210 ° C. over 4 hours, reacted at 210 ° C. for 1 hour, and then desired softening point at 13.3 kPa. To obtain polyester resins D and E, respectively. Table 1 shows the properties of each resin.

Comparative Production Example 2 (Production of Resin F)
A polyester resin F was obtained in the same manner as in Production Example 3 except that the titanium compound catalyst was replaced with dibutyltin oxide. The properties are shown in Table 1.

［注］
１）ＢＰＡ−ＰＯ：ビスフェノールＡのプロピレンオキサイド付加物（２．２モル）
２）ＢＰＡ−ＰＥ：ビスフェノールＡのエチレンオキサイド付加物（２．２モル）

[note]
1) BPA-PO: propylene oxide adduct of bisphenol A (2.2 mol)
2) BPA-PE: Ethylene oxide adduct of bisphenol A (2.2 mol)

Production Example 5 (Production of resin emulsion 1)
In a 5 liter stainless steel kettle, resin D 390 g, resin A 210 g, copper phthalocyanine pigment (ECB-301: manufactured by Dainichi Seika Kogyo Co., Ltd.), and nonionic surfactant [“Emulgen 430 (manufactured by Kao Corporation)”, 6 g of polyoxyethylene oleyl ether (HLB: 16.2)], 40 g of anionic surfactant [“Neopelex G-15 (manufactured by Kao)”, sodium dodecylbenzenesulfonate] and hydroxylation as a neutralizing agent 252 g of an aqueous potassium solution (concentration: 5% by weight) was added and dispersed at 95 ° C. with stirring at 250 r / min with a chi-type stirrer. The contents were stirred for 2 hours after reaching 95 ° C., and then 1118 g of deionized water was added dropwise at a rate of 6 g / min with stirring at 200 r / min with a chi-type stirrer to form a 200 mesh (mesh opening: 105 μm) wire mesh. Through the process, a finely divided resin emulsion 1 was obtained. The volume median particle size D ₅₀ of the resin particles in the obtained resin emulsion was 0.194 μm, the solid content concentration was 31.6% by weight, and no resin component remained on the wire mesh.

-
Production Example 6 (Production of resin emulsion 2)
A resin emulsion 2 that was atomized was obtained in the same manner as the resin emulsion 1 except that the resin D390g and the resin A210g were changed to the resin E390g and the resin B210g. The volume median particle size D ₅₀ of the resin particles in the obtained resin emulsion was 0.214 μm, the solid content concentration was 32.4% by weight, and no resin component remained on the wire mesh.

Comparative Production Example 3 (Production of resin emulsion 3)
Resin emulsion 3 was atomized by the same method as resin emulsion 1, except that resin D390g and resin A210g were changed to resin F390g and resin C210g. The volume median particle size D ₅₀ of the resin particles in the obtained resin emulsion was 0.211 μm, the solid content concentration was 33.9% by weight, and no resin component remained on the wire mesh.

Example 1
400 g of resin emulsion 1 was mixed in a 2 liter container at room temperature. Next, under stirring at 100 r / min with a Kai-type stirrer, 6.30 g of ammonium sulfate (molecular weight: 132.14) as a flocculant was dissolved in 104 g of deionized water and dissolved in an aqueous solution (pH: 6.1, 0). .25 mmol / L) was added dropwise at room temperature over 15 minutes. Thereafter, the mixed dispersion was heated at 1 ° C./5 min to form aggregated particles. When the temperature reached 85 ° C., the mixture was fixed at 85 ° C. and stirred for 1.5 hours, and then heating was stopped. In 1.5 hours, it was confirmed that the toner shape changed from aggregated particles to coalesced particles, and the shape changed to irregularly shaped particles, potato shapes, and spherical shapes. The average circularity was 0.987.
After cooling to room temperature, colored resin fine particle powder was obtained through a suction filtration step, a washing step and a drying step. The volume median particle size (D ₅₀ ) of the colored resin fine particle powder was 5.2 μm.
1.0 part by weight of hydrophobic silica (manufactured by Wacker Chemie, “TS530”, primary number average particle size: 8 nm) is externally added using a Henschel mixer to 100 parts by weight of the colored resin fine particle powder, and cyan. Toner was used. With the obtained cyan toner, a good image was obtained with a commercially available full-color printer. The obtained toner had a glass transition point of 57 ° C. The measurement of the glass transition point of the toner was performed according to the measurement method of the glass transition point of the resin (the same applies hereinafter).

Example 2
A colored resin fine particle powder was obtained in the same manner as in Example 1 except that 400 g of the resin emulsion 2 was used. The volume median particle size (D ₅₀ ) of the colored fine resin particle powder was 5.1 μm, and the average circularity was 0.982.
1.0 part by weight of hydrophobic silica (manufactured by Wacker Chemie, “TS530”, primary number average particle size: 8 nm) is externally added using a Henschel mixer to 100 parts by weight of the colored resin fine particle powder, and cyan. Toner was used. With the obtained cyan toner, a good image was obtained with a commercially available full-color printer. The obtained toner had a glass transition point of 57 ° C.

Comparative Example 1
Using 400 g of resin emulsion 3, colored resin fine particle powder was obtained in the same manner as in Example 1. The volume median particle size (D ₅₀ ) of the colored resin fine particle powder was 4.1 μm, and the average circularity was 0.938.
1.0 part by weight of hydrophobic silica (manufactured by Wacker Chemie, “TS530”, primary number average particle size: 8 nm) is externally added using a Henschel mixer to 100 parts by weight of the colored resin fine particle powder, and cyan. Toner was used. With the obtained cyan toner, an image with many transfer defects was obtained with a commercially available full color printer, and it was thus confirmed that the reaction time was not sufficiently united within 1.5 hours. The obtained toner had a glass transition point of 54 ° C.

The toners prepared in Examples 1 and 2 and Comparative Example 1 were evaluated for hydrolysis resistance as follows.
[Hydrolysis resistance]
The molecular weight of the resin in the toner was measured, and the hydrolyzability by alkali at the time of preparing the resin emulsion was confirmed. The resin used and the prepared toner weight average molecular weight Mw and Mw / Mn were measured by the GPC method, and the change rate of the weight average molecular weight Mw was used as a hydrolysis change rate and calculated from the following formula. Since the toner contains 90% by weight or more of the binder resin, the weight average molecular weight Mw of the toner can be substantially regarded as the weight average molecular weight Mw of the binder resin. The results are shown in Table 2. Here, when the rate of hydrolysis change is 90% or more, almost no hydrolysis is observed, and when it is 80% or more and less than 90%, although slight hydrolysis is observed, there is no practical problem. On the other hand, if the rate of hydrolysis change is less than 50%, the hydrolysis is significant and has a practical problem.
Hydrolysis change rate (%) = (weight average molecular weight Mw of resin in toner / weight average molecular weight Mw of resin used) × 100

  As mentioned above, it was confirmed that the polyester polycondensed in the presence of a specific titanium compound is excellent in hydrolysis resistance. On the other hand, in the comparative example, the molecular weight of the resin was changed by hydrolysis, and the image performance of the toner was inferior.

  The electrophotographic toner of the present invention can be produced in a short aggregation and coalescence time by using a polyester obtained by polycondensation in the presence of a specific titanium compound as a binder resin. In addition, since the hydrolysis resistance and toner image performance are good, it can be suitably used for a one-component developer or a two-component developer mixed with a carrier for electrophotography.

Claims (10)

By a method having a step (I) of emulsifying a raw material component containing a binder resin containing polyester in an aqueous medium, and a step (II) of aggregating and coalescing the emulsified particles of the binder resin obtained in the above step Toner obtained, the formula (1)
Ti (Z) ₄ (1)
(Wherein, Z represents an alkoxy group, an alkenyloxy group or an acyloxy group each having a total carbon number of 8 to 28, and the four Zs may be the same or different.)
And a titanium compound represented by the formula (2)
Ti (X) _n (Y) _m (2)
(Wherein X is an amino group having 1 to 28 carbon atoms, Y is an alkoxy group, alkenyloxy group or acyloxy group having a total carbon number of 1 to 28, and n and m are each 1 to 3 Represents an integer, and the sum of n and m is 4.) In the presence of at least one titanium compound selected from the group consisting of titanium compounds represented by the following formula, an alcohol component and a carboxylic acid component are subjected to polycondensation. An electrophotographic toner containing the polyester obtained in this way.   2. The electrophotographic toner according to claim 1, wherein the polyester is obtained by condensation polymerization of an alcohol component and a carboxylic acid component in the presence of an amide compound and / or an amine compound.   The electrophotographic toner according to claim 1, wherein the titanium compound is present in an amount of 0.01 to 2 parts by weight based on 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component.   The electrophotographic toner according to claim 2 or 3, wherein the amount of the amide compound and / or the amine compound is 0.005 to 2 parts by weight with respect to 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component.   5. The electron according to claim 2, wherein a weight ratio of the amide compound and / or the amine compound and the titanium compound [(amide compound and / or amine compound) / titanium compound] is 0.1-20. Toner for photography. A toner having a step (I) of emulsifying a raw material component containing a binder resin containing polyester in an aqueous medium, and a step (II) of aggregating and coalescing the emulsified particles of the binder resin obtained in the step Wherein the polyester of the step (I) is represented by the formula (1)
Ti (Z) ₄ (1)
(In the formula, Z represents an alkoxy group, an alkenyloxy group or an acyloxy group having a total carbon number of 8 to 28, and the four Zs may be the same or different.)
And a titanium compound represented by the formula (2)
Ti (X) _n (Y) _m (2)
(Wherein X is an amino group having 1 to 28 carbon atoms, Y is an alkoxy group, alkenyloxy group or acyloxy group having a total carbon number of 1 to 28, and n and m are each 1 to 3 Represents an integer, and the sum of n and m is 4.) obtained by polycondensing an alcohol component and a carboxylic acid component in the presence of at least one titanium compound selected from the group consisting of titanium compounds represented by A method for producing an electrophotographic toner.   The method for producing an electrophotographic toner according to claim 6, wherein the polyester is obtained by condensation polymerization of an alcohol component and a carboxylic acid component in the presence of an amide compound and / or an amine compound.   The method for producing an electrophotographic toner according to claim 6 or 7, wherein the titanium compound is present in an amount of 0.01 to 2 parts by weight with respect to 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component.   The method for producing an electrophotographic toner according to claim 7 or 8, wherein the amount of the amide compound and / or the amine compound is 0.005 to 2 parts by weight with respect to 100 parts by weight of the total amount of the alcohol component and the carboxylic acid component. . Used in the manufacture of an electrophotographic toner obtained by a method comprising a step of forming a raw material containing a binder resin in an aqueous medium, and (A) Formula (1)
Ti (Z) ₄ (1)
(Wherein, Z represents an alkoxy group, an alkenyloxy group or an acyloxy group each having a total carbon number of 8 to 28, and the four Zs may be the same or different.)
And a titanium compound represented by the formula (2)
Ti (X) _n (Y) _m (2)
(Wherein X is an amino group having 1 to 28 carbon atoms, Y is an alkoxy group, alkenyloxy group or acyloxy group having a total carbon number of 1 to 28, and n and m are each 1 to 3 An integer, and the sum of n and m is 4.) In the presence of at least one titanium compound selected from the group consisting of titanium compounds represented by: (b) an amide compound and / or an amine compound, A method for producing a polyester for an electrophotographic toner, comprising a step of polycondensation of a silver component and a carboxylic acid component.