JP4670508B2 - Toner for developing electrostatic image, method for producing toner for developing electrostatic image, developer for developing electrostatic image, and image forming method - Google Patents

Description

  The present invention relates to an electrostatic image developing toner used for electrophotographic image formation and a method for producing the same, an electrostatic image developing developer containing the electrostatic image developing toner, and the electrostatic image developing developer. The present invention relates to an image forming method using an agent.

  An image forming method for visualizing image information through an electrostatic charge image by an electrophotographic method or the like is currently used in various fields. In addition, advances in digitization and advanced image processing technology have advanced, and there is a demand for technology to obtain higher image quality. Particularly, color machines have been widely used, and higher image quality including color development is required more. ing.

On the other hand, there is a strong demand for low energy with an emphasis on the environment. When considering low energy in copying machines and printers, low temperature fixing in which the fixing process is performed at a low temperature can be mentioned.
As a method for achieving low-temperature fixing with a toner, a method using a resin having a low glass transition point as a binder resin of the toner is generally performed. However, a toner using a binder resin having a low glass transition point can achieve low-temperature fixability, but significantly deteriorates the stability of the toner such as storage stability of toner, cohesion in a developing machine, and fixing property. In addition, the image-forming coating film fixed on paper or the like is soft and is easily damaged by rubbing.

  As a means for achieving low-temperature fixing, a method using a crystalline resin has been proposed (see, for example, Patent Document 1 or 2). Although these methods can lower the fixing temperature, there is a problem that the toner melted at the time of fixing penetrates too much into the paper and a uniform and high-density image cannot be obtained.

Furthermore, many techniques have been proposed in which a crystalline resin is not used alone as a binder resin, but is used in combination with an amorphous resin (see, for example, Patent Document 3). Moreover, the technique using the polymer which couple | bonded crystalline resin and amorphous resin chemically is disclosed (for example, refer patent documents 4-7). However, when the amorphous resin is more than the crystalline resin, the amorphous resin becomes a continuous phase and the crystalline resin becomes a dispersed phase, but in this case, the melting of the entire toner is caused by the softening temperature of the amorphous resin. Dominated and low temperature fixing is difficult. When low-temperature fixing is enabled by using a crystalline resin with higher plasticity than an amorphous resin, the stability of the toner is impaired in the same manner as when a resin having a low glass transition point is used as the binder resin of the toner. At the same time, the strength of the image-forming coating film is weak, and stains and defects occur with respect to rubbing.
On the contrary, when the amount of the crystalline resin is larger than that of the amorphous resin, the effect of using the amorphous resin together cannot be sufficiently obtained.

In addition, proposals have been made to achieve low-temperature fixing by using a low melting point wax (see, for example, Patent Document 8 or 9). These methods use wax as a mold release agent, and the wax melted at the time of fixing exudes to the surface of the image to make it peelable. However, in these methods, the melt viscosity of the wax is lowered and the offset is reduced. It tends to occur and is effective only at temperatures sufficiently higher than the melting point. Furthermore, the current situation is that the exudation of the wax depends on the compatibility between the binder resin and the wax and the melt viscosity of the binder resin, making it difficult to achieve low temperature fixing.
Japanese Patent Publication No. 4-24702 Japanese Patent Laid-Open No. 9-329917 Japanese Patent Laid-Open No. 2-79860 JP-A-1-163756 JP-A-4-81770 JP-A-4-155351 JP-A-5-44032 JP-A-4-107567 JP-A-8-114942

An object of the present invention is to solve the problems in the prior art.
That is, an object of the present invention is to provide an electrostatic image developing toner excellent in low temperature fixability and image strength of a fixed image under high temperature and high humidity, a method for producing the electrostatic image developing toner, and the electrostatic charge. An object of the present invention is to provide an electrostatic charge image developing developer containing an image developing toner and an image forming method using the electrostatic charge image developing developer.

As a result of intensive studies to overcome the problems in the prior art, the present inventor has found that the above problems can be achieved by the following means, and has completed the present invention.
That is, the electrostatic image developing toner of the present invention is
<1> An electrostatic charge image developing toner comprising a binder resin, a colorant and an ester compound, wherein the ester compound reacts with a dicarboxylic acid containing a sulfur atom and an aliphatic dialcohol containing no sulfur atom. The electrostatic dial image developing toner is characterized in that the aliphatic dialcohol has an even number of carbon atoms and the ester compound has a weight average molecular weight of 5,000 to 12,000.

<2> A toner for developing electrostatic images comprising a binder resin, a colorant and an ester compound, wherein the ester compound reacts a dialcohol containing a sulfur atom with an aliphatic dicarboxylic acid containing no sulfur atom. The electrostatic image developing toner is characterized in that the aliphatic dicarboxylic acid has an even number of carbon atoms and the ester compound has a weight average molecular weight of 5,000 to 12,000.

Further, the method for producing the toner for developing an electrostatic charge image of the present invention comprises:
<3> A dispersion step of dispersing binder resin particles, colorant particles and ester compound particles in an aqueous dispersion medium, an aggregation step of aggregating the dispersed particles with metal ions to form aggregated particles, and the aggregated particles A process for producing a toner for developing an electrostatic charge image, comprising: a heat-bonding process comprising: reacting a dicarboxylic acid containing a sulfur atom with an aliphatic dialcohol containing no sulfur atom as the ester compound particles; And a method of producing a toner for developing an electrostatic image, wherein the aliphatic dialcohol has an even number of carbon atoms and ester compound particles having a weight average molecular weight of 5000 to 12000.

<4> A dispersion step of dispersing binder resin particles, colorant particles and ester compound particles in an aqueous dispersion medium, an aggregation step of aggregating the dispersed particles with metal ions to form aggregated particles, and the aggregated particles A process for producing a toner for developing an electrostatic charge image, wherein the ester compound particles react with a dialcohol containing a sulfur atom and an aliphatic dicarboxylic acid containing no sulfur atom. In this method, the aliphatic dicarboxylic acid has an even number of carbon atoms, and ester compound particles having a weight average molecular weight of 5000 to 12000 are used.

Furthermore, the developer for developing an electrostatic charge image of the present invention is:
<5> An electrostatic charge image developing developer comprising the electrostatic charge image developing toner according to <1>.

  <6> An electrostatic charge image developing developer comprising the electrostatic charge image developing toner according to <2>.

The image forming method of the present invention includes
<7> A developing step of developing the electrostatic latent image formed on the latent image carrier with a developer for developing an electrostatic charge image containing toner to form a toner image, and transferring the toner image onto a transfer medium. An image forming method comprising: a transfer step of forming a transfer image; and a fixing step of fixing the transfer image, wherein the developer for developing an electrostatic image is for developing an electrostatic image according to <5>. An image forming method characterized by being a developer.

  <8> A developing step of developing the electrostatic latent image formed on the latent image carrier with a developer for developing an electrostatic image containing toner to form a toner image, and transferring the toner image onto a transfer medium. An image forming method comprising: a transfer step for forming a transfer image; and a fixing step for fixing the transfer image, wherein the developer for developing an electrostatic charge image is for developing an electrostatic charge image according to <6>. An image forming method characterized by being a developer.

  According to the present invention, an electrostatic charge image developing toner excellent in low temperature fixability and fixed image strength under high temperature and high humidity, a method for producing the electrostatic charge image developing toner, and the electrostatic charge image development It is possible to provide a developer for developing an electrostatic charge image containing a toner for use, and an image forming method using the developer for developing an electrostatic charge image.

The electrostatic image developing toner of the present invention is an electrostatic image developing toner containing a binder resin, a colorant and an ester compound, and the ester compound does not contain a dicarboxylic acid containing a sulfur atom and a sulfur atom. An ester compound obtained by reacting an aliphatic dialcohol having an even number of carbon atoms (hereinafter sometimes referred to as “first ester compound”), or a dialcohol containing a sulfur atom and carbon containing no sulfur atom. An ester compound obtained by reacting an aliphatic dicarboxylic acid having an even number is used (hereinafter sometimes referred to as “second ester compound”). The first and second ester compounds each have a weight average molecular weight of 5,000 to 12,000.

Each of the first and second ester compounds contains a sulfur atom in the molecule and has a thioether structure. By using an ester compound having a thioether structure, the electrostatic charge image developing toner of the present invention can achieve both low-temperature fixability and chargeability at a high level as compared with conventional crystalline polyester. In particular, the inclusion of a thioether structure reduces the environmental dependency on simple ester groups having the same plasticity. However, on the other hand, the crystal inhibition of sulfur atoms in the molecule is higher than that of carbon atoms, and the crystal density is small. It has been found that the crystalline compound having a thioether structure exhibits thermal reversibility when mixed with an amorphous resin, so that the image after fixing is small in plasticization and obtains high image strength. be able to. In addition, the first and second ester compounds in the present invention are monomers not containing a sulfur atom (in the first ester compound, an aliphatic dialcohol, and in the second ester compound, an aliphatic dicarboxylic acid). Since a monomer having an even number of carbon atoms is used, the crystal density is increased and a high image intensity can be obtained.
Hereinafter, in describing the present invention in detail, each component used in the electrostatic image developing toner will be described first.

(Ester compound)
As described above, the ester compound used in the present invention is characterized by containing a thioether structure, and the first ester compound is an aliphatic having a dicarboxylic acid containing a sulfur atom and an even number of carbon atoms not containing a sulfur atom. The dialcohol and the second ester compound are oligomers or resins obtained by polycondensation reaction between a dialcohol containing a sulfur atom and an aliphatic dicarboxylic acid containing no sulfur atom and having an even number of carbon atoms . From the viewpoint of obtaining higher image strength, it is more preferable that the number of carbon atoms of the monomer containing a sulfur atom is an even number in both the first and second ester compounds. Moreover, with a 1st ester compound and a 2nd ester compound, a 1st ester compound is used more preferably from a viewpoint of the cost of a monomer (raw material) and the ease of a synthesis | combination.

  The first ester compound is not particularly limited as long as it is a dicarboxylic acid containing a sulfur atom. For example, thiodicarboxylic acids such as 3,3′-thiodipropionic acid and thiodibutyric acid can be used. , 3,3′-dithiodipropionic acid, and the like. Among these, thiodicarboxylic acid is more preferable and particularly preferable from the viewpoint that the melting point can be set to an appropriate temperature.

  Examples of dialcohols having an even number of carbon atoms that do not contain sulfur atoms include ethylene glycol, butanediol, hexanediol, octanediol, decanediol, and dodecanediol. Preferred are hexanediol, octanediol, decanediol, dodecanediol and the like, that is, saturated aliphatic dialcohols having an even number of carbon atoms in the molecule having 6 to 12 methylene groups. Since these dialcohols have an even number of alkyl chains, the crystal density of the dialcohols increases, so that the strength of the coating film can be increased.

  Next, the second ester compound is not particularly limited as long as it is a dialcohol containing a sulfur atom. For example, 2,2′-thiodiethanol, 3,3′-thiodipropanol can be used. And the like, dithiodialcohols such as 2,2′-dithiodiethanol, 3,3′-dithiodipropanol, and the like. Of these, thiodialcohol is more preferable, and 3,3′-thiodipropanol is particularly preferable from the viewpoint that the melting point can be set to an appropriate temperature.

  Examples of the dicarboxylic acid having an even number of carbon atoms not containing a sulfur atom include, for example, saturated aliphatic dicarboxylic acids such as oxalic acid, succinic acid, adipic acid, suberic acid, sebacic acid, decanedioic acid, and dodecanedioic acid, Examples thereof include unsaturated aliphatic dicarboxylic acids such as fumaric acid and maleic acid, and hydroxydicarboxylic acids such as malic acid. Preferred are adipic acid, suberic acid, sebacic acid, decanedioic acid, dodecanedioic acid and the like, that is, saturated aliphatic dicarboxylic acid having an even number of carbon atoms in the molecule having 6 to 12 methylene groups. Since these dicarboxylic acids have an even number of alkyl chains, the crystal density of the dicarboxylic acids increases, so that the strength of the coating film can be increased.

= Weight average molecular weight =
Next, the molecular weight of the first and second ester compounds obtained from the monomers (hereinafter, both may be simply referred to as “ester compounds”) will be described. In the present invention, it is an essential requirement that the weight average molecular weight of the ester compound is 5000 to 12000, and more preferably 8000 to 10,000. When the weight average molecular weight is less than 5000 or more than 12000, the plasticity of the ester compound to the binder resin deteriorates in heat melting in the fixing step, solidification by cooling, fixing to paper, etc. The recrystallization in the image film is not good, and the image strength, particularly the strength against rubbing cannot be obtained.

In the present invention, the weight average molecular weight of the resin is determined by measuring a THF (tetrahydrofuran) soluble material using HLC-8020 manufactured by Tosoh Corporation, and using a molecular weight calibration curve created by a monodisperse polystyrene standard sample. The molecular weight is calculated.
Specifically, TSK gei, SuperHM-H (6.0 mmID × 15 cm × 2) is used as a column, THF is used as a solution, and measurement conditions are a sample concentration of 0.5% and a flow rate of 0.6 ml / min. Sample injection volume 10 μl, measurement temperature 40 ° C., calibration curve is A-500, F-1, F-10, F-80, F-380, A-2500, F-4, F-40, F-128, Made from 10 samples of F-700. The data collection interval in sample analysis was 300 ms.

= Melting point =
Moreover, it is preferable that melting | fusing point of the said crystalline compound (ester compound) is 55 to 100 degreeC. When the melting point is within this range, the plasticizing effect on the binder resin is large, and the low-temperature fixability is favorable.
The melting point of the ester compound can be measured as follows. A differential thermal scanning calorimeter DSC-7 manufactured by Perkinelmer is used, the melting point of indium and zinc is used for temperature correction of the detection part of the apparatus, and the heat of fusion of indium is used for correction of heat quantity. For the sample, an aluminum pan was used, an empty pan was set as a control, the temperature was increased from room temperature to 150 ° C. at a temperature increase rate of 10 ° C./min, and the temperature was decreased from 150 ° C. to −30 ° C. at a rate of 10 ° C./min. Further, the temperature was increased from −30 ° C. to 150 ° C. at a rate of 10 ° C./min, and the maximum endothermic peak temperature at the second temperature increase was taken as the melting point.

= Content =
The first and second ester compounds in the present invention are preferably used in a ratio of 5 to 30% by mass with respect to the binder resin. If it is this range, the plasticizing effect with respect to binder resin is suitable. More preferably, it is 8-20 mass%.

(Binder resin)
= Ethylenically unsaturated polymer =
In the present invention, polymers that can be used as the binder resin or binder resin particles are not particularly limited, but homopolymers or copolymers of ethylenically unsaturated monomers including vinyl monomers are preferably used. it can. Examples of monomers constituting these homopolymers or copolymers include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic (Meth) acrylic acid esters such as n-butyl acid, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; acrylonitrile, Ethylenically unsaturated nitriles such as methacrylonitrile; Ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; Vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; Vinyl methyl ketone, vinyl ethyl ketone and vinyl Vinyl ketones such as Puropeniruketon, ethylene, propylene, and the like olefins such as butadiene, beta-carboxyethyl acrylate and the like. A homopolymer composed of these monomers, a copolymer obtained by copolymerizing two or more of these, and a mixture thereof can be used.

  In addition, epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, etc., non-vinyl condensation resins, or mixtures of these with addition polymer resins obtained from the ethylenically unsaturated monomers And a graft polymer obtained by polymerizing an ethylenically unsaturated monomer in the presence of these.

  As a polymerization initiator used for the polymerization of the binder resin, an appropriate polymerization initiator can be appropriately selected and used. For example, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobissobutyronitrile Azo or diazo polymerization initiators such as benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxy carbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide and other peroxide polymerization initiators, dodecanethiol and other thiols And ammonium peroxodisulfate

  When polymerizing the ethylenically unsaturated monomer as described above, a binder resin particle dispersion can be prepared by carrying out emulsion polymerization using an ionic surfactant or the like. In the case of other resins, if the resin is oily and dissolves in a solvent having a relatively low solubility in water, the resin is dissolved in those solvents, together with an ionic surfactant or polymer electrolyte in water. A binder resin particle dispersion can be prepared by dispersing as fine particles with a disperser such as a homogenizer and then evaporating the solvent by heating or decompressing.

= Volume average particle size =
The particle size of the binder resin particles in the dispersion is preferably 120 to 300 nm, and more preferably 160 to 280 nm. It is preferable that the particle size is in the above range since the particle size distribution of the obtained toner is narrow, free particles are not generated, and the performance and reliability of the toner are improved.
The particle size of the binder resin particles in these dispersions can be measured with a laser diffraction particle size distribution analyzer LA-700 (manufactured by Horiba, Ltd.).

= Polyester resin =
On the other hand, in the toner of the present invention, it is more preferable to use a polyester resin as the binder resin from the viewpoint of low-temperature fixing. The polyester resin is advantageous in that the binder resin particle dispersion can be easily prepared by adjusting the acid value of the resin and emulsifying and dispersing the resin using an ionic surfactant. The polyester resin used for emulsification dispersion is synthesized from a polyvalent carboxylic acid and a polyhydric alcohol.

  Examples of polyvalent carboxylic acids include terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalenedicarboxylic acid and other aromatic carboxylic acids, maleic anhydride, fumaric acid, succinic acid, alkenyl anhydride Examples thereof include aliphatic carboxylic acids such as succinic acid and adipic acid, and alicyclic carboxylic acids such as cyclohexanedicarboxylic acid. One or more of these polyvalent carboxylic acids can be used. Among these polyvalent carboxylic acids, it is preferable to use aromatic carboxylic acids, and from the viewpoint of securing good fixability as a cross-linked structure or branched structure, trivalent or higher carboxylic acids (trimellitic acid) together with dicarboxylic acids And acid anhydrides thereof) are preferably used in combination.

  Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin and other aliphatic diols, cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, etc. Aromatic diols such as alicyclic diols, ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, and the like, and one or more of these polyhydric alcohols can be used. Among these polyhydric alcohols, aromatic diols and alicyclic diols are preferable, and aromatic diols are more preferable. In addition, from the viewpoint of securing good fixability as a crosslinked structure or a branched structure, it is preferable to use a trihydric or higher polyhydric alcohol (glycerin, trimethylolpropane, pentaerythritol) together with the diol.

  In addition, monocarboxylic acid and / or monoalcohol is further added to the polyester resin obtained by polycondensation of polycarboxylic acid and polyhydric alcohol to esterify the hydroxyl group and / or carboxyl group at the polymerization terminal. The acid value of the polyester resin may be adjusted. Examples of the monocarboxylic acid include acetic acid, acetic anhydride, benzoic acid, trichloroacetic acid, trifluoroacetic acid, propionic anhydride and the like, and examples of the monoalcohol include methanol, ethanol, propanol, octanol, 2-ethylhexanol, and trifluoroethanol. , Trichloroethanol, hexafluoroisopropanol, phenol and the like.

  The polyester resin can be produced by subjecting the polyhydric alcohol and polyhydric carboxylic acid to a condensation reaction according to a conventional method. For example, the above polyhydric alcohol and polyvalent carboxylic acid, if necessary, a catalyst is added, blended in a reaction vessel equipped with a thermometer, a stirrer, a flow-down condenser, and in the presence of an inert gas (such as nitrogen gas) Heat at 150 to 250 ° C. to continuously remove by-product low-molecular compounds out of the reaction system, stop the reaction when a predetermined acid value is reached, cool, and obtain the desired reactant Can be manufactured.

  Examples of the catalyst used for the synthesis of this polyester resin include esterification catalysts such as organic metals such as dibutyltin dilaurate and dibutyltin oxide, and metal alkoxides such as tetrabutyl titanate. The addition amount of such a catalyst is preferably 0.01 to 1% by mass with respect to the total amount of raw materials.

= Magnetic toner =
When the toner of the present invention is used as a magnetic toner, magnetic powder may be contained in the binder resin. As such magnetic powder, a substance magnetized in a magnetic field is used. Specifically, ferromagnetic powders such as iron, cobalt and nickel, or compounds such as ferrite and magnetite can be used. In particular, when the toner is obtained in the aqueous layer in the present invention, the water layer migration property of the magnetic material is important, and it is preferable to perform surface modification, for example, hydrophobization treatment.

= Glass transition point =
The glass transition point of the binder resin used in the present invention is preferably 52 to 68 ° C, and more preferably 55 to 64 ° C. A glass transition temperature within the above range is preferable because it is suitable for low-temperature fixing.
In the present invention, the glass transition point of the resin can be measured as follows. A differential thermal scanning calorimeter DSC-7 manufactured by Perkinelmer is used, the melting point of indium and zinc is used for temperature correction of the detection part of the apparatus, and the heat of fusion of indium is used for correction of heat quantity. The measurement method is based on ASTM D3418-82. The sample is an aluminum pan, an empty pan is set as a control, and the temperature is raised from room temperature to 150 ° C. at a heating rate of 10 ° C./min. The temperature is lowered to 10 ° C./min at a rate of 10 ° C./min, and further raised from −30 ° C. to 150 ° C. at a rate of 10 ° C./min.

= Weight average molecular weight =
The weight average molecular weight of the binder resin used in the present invention is preferably 5000 to 50000, and more preferably 8000 to 35000.
In addition, the weight average molecular weight of binder resin can be measured by the method similar to the measuring method in the above-mentioned ester compound.

= Content =
The content of the binder resin in the toner is preferably 40 to 95% by mass, and more preferably 50 to 70% by mass. Further, from the viewpoint of obtaining better low-temperature fixability, the proportion of the polyester resin in the binder resin is preferably 55 to 65% by mass.

(Coloring agent)
As the colorant used in the present invention, known ones can be used. Examples of the black pigment include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, and magnetite.
Examples of yellow pigments include yellow lead, zinc yellow, yellow iron oxide, cadmium yellow, chrome yellow, Hansa yellow, Hansa yellow 10G, benzidine yellow G, benzidine yellow GR, selenium yellow, quinoline yellow, and permanent yellow. NCG etc. are mentioned.

Examples of the orange pigment include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, benzidine orange G, indanthrene brilliant orange RK, indanthrene brilliant orange GK and the like.
Red pigments include Bengala, cadmium red, red lead, mercury sulfide, watch young red, permanent red 4R, risor red, brilliantamine 3B, brilliantamine 6B, dapon oil red, pyrazolone red, rhodamine B rake, lake red C , Rose bengal, oxin red, alizarin lake and the like.

Blue pigments include bitumen, cobalt blue, alkali blue rake, Victoria blue rake, fast sky blue, induslen blue BC, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxare. Rate and so on.
Examples of purple pigments include manganese purple, fast violet B, and methyl violet lake.

Examples of the green pigment include chromium oxide, chromium green, pigment green, malachite green lake, final yellow green G, and the like.
Examples of white pigments include zinc white, titanium oxide, antimony white, and zinc sulfide.
Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white.

  Furthermore, examples of the dye include various dyes such as basic, acidic, dispersion, and direct dyes, such as nigrosine, methylene blue, rose bengal, quinoline yellow, and ultramarine blue.

  The colorant used in the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP permeability, and dispersibility in the toner. The addition amount of the colorant is in the range of 1 to 20% by mass with respect to 100% by mass of the binder resin of the toner. When a magnetic material is used as the black colorant, it is added in the range of 30 to 100% by mass, unlike other colorants.

  Further, these colorants can be used alone or mixed and further in a solid solution state. These colorants are dispersed by a known method. For example, a media type dispersing machine such as a rotary shear type homogenizer, a ball mill, a sand mill, or an attritor, a high-pressure opposed collision type dispersing machine, or the like is preferably used.

These colorant particles are preferably dispersed in an aqueous dispersion medium using a polar surfactant and using the homogenizer or the like.
The volume average particle diameter of the colorant particles is preferably 120 to 360 nm, and more preferably 160 to 260 nm. It is preferable that the volume average particle diameter is in the above range since the color development property, color reproducibility, OHP permeability, etc. of the toner can be improved.
The volume average particle diameter of the colorant particles can be measured by the same method as that for the binder resin described above.

(Release agent)
It is preferable to include a release agent in the toner of the present invention in order to improve releasability during fixing. Examples of the release agent that can be used in the present invention include low molecular weight polyolefin waxes such as polyethylene, polypropylene, and polybutene, and plants such as carnauba wax, rice wax, candelilla wax, wood wax, jojoba oil, and the like. And waxes, animal waxes such as beeswax, montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax and the like, petroleum wax, and modified products thereof.
Paraffin wax, microcrystalline wax, and polyolefin wax are preferable, and paraffin wax and polyethylene wax are particularly preferable. A release agent having a small polarization, such as paraffin wax and polyethylene wax, is preferable because it has a low affinity with the binder resin and crystalline compound of the toner and the release agent can be easily oozed out during fixing.
The melting point of the release agent used in the toner of the present invention is preferably 60 to 120 ° C., and more preferably 85 to 105 ° C.

  Further, the volume average particle diameter of the release agent particles in the dispersion is preferably 120 to 360 nm, and more preferably 160 to 300 nm. A volume average particle size within the above range is preferable because uneven distribution of the composition among the toner particles can be suppressed, and the performance and reliability of the toner are improved. The volume average particle diameter of the release agent particles can be measured by the same method as that for the binder resin described above.

(Charge control agent)
In the present invention, a charge control agent can be blended in order to further improve and stabilize the chargeability of the toner. As the charge control agent, quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments can be used. In order to control the ionic strength that affects the properties and to reduce contamination of wastewater, materials that are difficult to dissolve in water are more preferable.

(Inorganic fine particles and organic fine particles)
In the present invention, inorganic fine particles can be added in a wet manner in order to stabilize the chargeability of the toner. Examples of inorganic fine particles include silica, alumina, titania, calcium carbonate, magnesium carbonate, and tricalcium phosphate, all of which are usually used as external additives on the toner surface, such as ionic surfactants and polymer acids. It can be used by dispersing in a polymer base.
Also, for the purpose of imparting fluidity and improving cleaning properties, the toner is dried and then fine particles such as silica, alumina, titania, calcium carbonate, vinyl resin, polyester, silicone, etc. Organic fine particles such as these can be added to the toner surface by applying a shearing force in a dry state and used as a flow aid or cleaning aid.

(Toner production method)
The toner of the present invention is not limited to the production method and can be produced by any method, but is preferably produced by the following method. That is, a dispersion step in which binder resin particles, colorant particles and ester compound particles are dispersed in an aqueous dispersion medium, an aggregation step in which the dispersed particles are aggregated with metal ions to form aggregated particles, and the aggregated particles are thermally fused. And a method for producing a toner for developing an electrostatic image using the first or second ester compound described above as the ester compound particles.

  In the dispersion step, the binder resin particles, the colorant particles, and the ester compound particles are each dispersed in an aqueous dispersion medium. More specifically, the binder resin particle dispersion, the colorant particle dispersion, and the ester compound dispersion are dispersed. It is preferable to prepare liquids and mix them.

  In the toner production method of the present invention, it is preferable to further add a release agent, and the release agent particles are preferably added in the dispersion step. That is, binder resin particles, colorant particles, ester compound particles and release agent particles are dispersed in an aqueous dispersion medium (dispersion step), and a mixed solution of these dispersions is aggregated with metal ions (aggregation step). Further, it is preferable to produce the aggregated particles by heat-sealing (heat-sealing step).

  Further, the addition of other additives as described above may be dispersed in any of the binder resin particle dispersion, the colorant particle dispersion, the ester compound dispersion, or the release agent particle dispersion, You may add and mix, after preparing the dispersion liquid which disperse | distributes another additive.

  In addition, a binder resin fine particle dispersion and an ester dispersion containing an ionic surfactant are mixed with a colorant particle dispersion, and heterogeneous by an ionic surfactant having a polarity opposite to that of the ionic surfactant. Aggregated particles having a toner diameter can be formed by causing aggregation, and then heated to a temperature equal to or higher than the glass transition point of the binder resin to thermally fuse the aggregated particles, and then washed and dried to obtain a toner. it can.

  It is also preferable to obtain toner by the following method. In the initial stage of mixing the binder resin fine particle dispersion, the colorant particle dispersion, and the ester compound dispersion, the balance of the amount of the ionic dispersant of each polarity is shifted in advance, and an inorganic metal salt such as polyaluminum chloride. Then, the polymer is ionically neutralized, and then the first-stage base aggregated particles are formed and stabilized at a temperature not higher than the glass transition point of the binder resin. As a second step, a resin fine particle dispersion treated with an ionic dispersant of a polarity and quantity that compensates for the ionic balance deviation is added, and if necessary, the binder resin fine particles and additional resin in the aggregated particles After heating slightly below the glass transition point of the resin contained in the fine particles and stabilizing it at a higher temperature, the particles added in the second stage of agglomeration by heating above the glass transition point are used as the base aggregate particles It may be heat-sealed while adhering to the surface. Further, this stepwise operation of aggregation may be repeated a plurality of times. This two-stage method is effective in improving the inclusion properties of the ester compound, the release agent and the colorant.

  The two-stage method will be described in detail. Between the agglomeration step and the heat fusion step, a fine particle dispersion in which fine particles are dispersed is added and mixed in the agglomerated particle dispersion to adhere the fine particles to the aggregated particles. And a step (attachment step) of forming attached particles.

  In the adhesion step, the fine particle dispersion is added to and mixed with the aggregated particle dispersion prepared in the aggregation step, and the fine particles are adhered to the aggregated particles to form the adhered particles. Since this corresponds to newly added particles, it is sometimes referred to as “additional fine particles” in this specification. As the additional fine particles, in addition to the binder resin fine particles, ester compound particles, release agent particles, colorant particles and the like may be used singly or in combination. The method of additionally mixing the fine particle dispersion is not particularly limited, and may be performed gradually, for example, or may be performed stepwise by dividing into a plurality of times. In this way, by adding and mixing fine particles (additional fine particles), the generation of fine particles can be suppressed, and the particle size distribution of the resulting electrostatic image developing toner can be sharpened, contributing to higher image quality. To do.

  Also, by providing an adhesion step, a pseudo shell structure can be formed, and the toner surface exposure of internal additives such as colorants and low melting point compounds can be reduced, resulting in improved chargeability and life. Can do. Furthermore, at the time of fusing in the heat fusing process, the particle size distribution can be maintained and fluctuations thereof can be suppressed, and a surfactant or a stabilizer such as a base or an acid can be used to enhance the stability at the time of fusing. This is advantageous in that the addition can be made unnecessary and the amount of addition can be suppressed to the minimum, and the cost can be reduced and the quality can be improved. Further, if this method is used, the toner shape can be easily controlled by adjusting the temperature, the number of stirrings, the pH, and the like in the heat sealing step.

  In the aggregating step of the agglomerated particles and / or the adhering step of the additional fine particles, the type and amount of the ionic surfactant for adjusting the polarity of the dispersion liquid are selected to control the degree of aggregation and / or adhesion. Can do. For example, by dispersing the binder resin fine particles and ester compound particles in a solution containing an anionic surfactant, respectively, dispersing a colorant in a solution containing a cationic surfactant, and mixing them, The binder resin fine particles and the colorant particles can be aggregated.

  Also, the balance of the polarity and blending amount of the ionic surfactant contained in the dispersion to be mixed is shifted in advance, and the polarity and amount of the ionic surfactant is added to compensate for the balance shift. It is also possible to carry out agglomeration and / or adhesion.

  In the agglomeration step, the binder resin fine particle dispersion, the colorant particle dispersion, the ester compound dispersion and the low-melting-point compound particle dispersion, and if necessary, the release agent particle dispersion are mixed to form agglomerated particles. And a dispersion obtained by mixing a binder resin fine particle, a colorant, an ester compound, a low melting point compound and, if necessary, a release agent particle dispersion, have a polarity different from that of the dispersion A method of forming agglomerated particles by adding a surfactant can be employed.

  The thermal fusion process is preferably performed in the range of T + 10 to T + 30 ° C. when the glass transition point of the binder resin is T ° C.

  In the present invention, a desired toner can be obtained through any washing step, solid-liquid separation step, and drying step after the end of heat fusion, but the washing step is sufficient to develop and maintain charging properties. It is preferable to perform substitution cleaning with ion-exchanged water. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, and the like are preferably used from the viewpoint of productivity. Further, the drying process is not particularly limited, but freeze drying, flash jet drying, fluidized drying, vibration fluidized drying and the like are preferably used from the viewpoint of productivity.

  The dispersion medium used in the dispersion step is an aqueous dispersion medium. For example, it contains water such as distilled water and ion-exchanged water as a main component, and contains a small amount (30% by volume or less) of a water-miscible solvent such as alcohol. Good. The water-miscible dispersion medium may be included alone or in combination of two or more.

  As the metal ion (aggregating agent) used in the aggregation step, an inorganic metal salt having a divalent or higher charge can be used. The metal element constituting the inorganic metal salt is a group 2A, 3A, 4A, 5A, 6A, 7A, 8, 1B, 2B, 3B in the periodic table (LUPAC's 1989 inorganic chemical nomenclature) The revised group number has a charge of two or more valences belonging to Group 2 to Group 8 and Group 11 to Group 13).

  Specifically, metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and inorganic metal polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide And so on. Of these, aluminum salts and polymers thereof are preferred. In general, in order to obtain a sharper particle size distribution, the inorganic metal salt polymer is more suitable when the inorganic metal salt has a valence of 3 or more than the bivalence and the same valence. ing.

  The amount of the flocculant added is not particularly limited as long as it does not impair the effects of the present invention, but specifically, it is in the range of 0.01 to 10% by mass with respect to the dispersion, preferably The range is from 0.05 to 5% by mass, and more preferably from 0.1 to 2% by mass. When the addition amount is less than 0.01% by mass, the dispersion liquid such as the binder resin particle dispersion, the colorant particle dispersion, and the ester compound particle dispersion becomes unstable, resulting in aggregation, Since the stability between the particles differs during aggregation, the release of specific particles may occur. Moreover, when it exceeds 10 mass%, there exists a concern that the particle size distribution of an aggregated particle may become wide, and control of a particle diameter will become difficult.

  In the toner production method of the present invention, the emulsion polymerization of the binder resin fine particles, the dispersion of the colorant, the additive dispersion of the binder resin fine particles, the dispersion of the ester compound or the release agent, the aggregation thereof, or the stabilization thereof, etc. Examples of surfactants used for the purpose include anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap, and cationic interfaces such as amine salt type and quaternary ammonium salt type. Activators can be used. It is also effective to use a nonionic surfactant such as polyethylene glycol, alkylphenol ethylene oxide adduct, and polyhydric alcohol. As these dispersing means, general means such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, a dyno mill and the like can be used.

  The acid value of the toner of the present invention is important not only for improving and stabilizing the inclusion of the ester compound particles, colorant particles and the like in the toner, but also for the charging property, and the range of 5 to 50 mg-KOH. preferable. When the acid value is in the above range, the encapsulating property and stability of the ester compound particles, the colorant particles and the like are improved and appropriate charging can be obtained. Moreover, since the component which gives an acid value is a suitable quantity and it does not produce bridge | crosslinking, favorable fixability is obtained.

  In the toner of the present invention, the volume average particle diameter D50v of the toner particles is preferably in the range of 3.0 to 6.0 μm. Furthermore, the volume average particle size distribution index GSDv (D84v / D16v) is preferably 1.30 or less, and the ratio (GSDv / GSDp) between the volume average particle size distribution index GSDv and the number average particle size distribution index GSDp is 0. .95 or more is preferable. In any case, it is possible to provide a toner for developing an electrostatic charge image that can form an image with excellent image quality. Further preferable ranges are D50v of 4.0 to 5.8 μm, GSDv of 1.0 to 1.28, and GSDv / GSDp of 0.95 to 1.2. When the volume average particle diameter D50v of the toner of the present invention is in the above range, the amount of toner necessary for obtaining the desired color can be reduced, fixing with low energy is possible, and this is advantageous for low-temperature fixability. It is preferable. Similarly, it is preferable because there is little transfer residue from the photoreceptor, which is advantageous for transferability. When the volume average particle size distribution index GSDv is within the above range, high resolving power is obtained. It is preferable that the ratio (GSDv / GSDp) of the volume average particle size distribution index and the number average particle size distribution index is in the above range because good chargeability can be obtained and image defects such as toner scattering and fogging do not occur.

  For the volume average particle size, volume average particle size distribution index, and number average particle size distribution index of the toner, for example, a measuring instrument such as Coulter Counter TA-II (manufactured by Nikka Kisha Co., Ltd.) or Multisizer II (manufactured by Nikka Kisha Co., Ltd.) is used. In the present invention, measurement was performed using a Coulter counter TA-II.

In the present invention, Isoton II (manufactured by Beckman Coulter, Inc.) is used as the electrolytic solution, and the measurement sample (toner) is 0.5% in 2 ml of a 5% aqueous solution of sodium alkylbenzenesulfonate as a dispersant. Add 50 mg of this solution into 100 to 150 ml of the electrolyte.The electrolyte in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the aperture diameter is measured by the Coulter counter TA-II type. The volume average distribution and the number average distribution are determined by measuring the particle size distribution of 2.0 to 64.0 μm using a 100 μm aperture, and the number of particles to be measured is 50,000. The weight average particle size is obtained from the distribution.
In the particle size distribution, a cumulative distribution is drawn from the smaller diameter side to the divided particle size range (channel), and the particle size that becomes 16% cumulative is defined as the volume average particle size D16v and the number average particle size D16p. In addition, the particle size which is 84% cumulative is defined as the volume average particle size D84v and the number average particle size D84p. Using these, the volume average particle size distribution index GSDv is obtained from D84v / D16v, / D16p.

The toner of the present invention can be used in any form from an irregular shape to a spherical shape. However, when the shape factor SF1 of the toner of the present invention is in the range of 110 to 140, the developability and transferability are excellent. Further, it is preferable because a toner for developing an electrostatic image can be provided. A more preferable range of the shape factor SF1 is 125 to 138. The shape factor SF1 is an average value of the shape factors, and is calculated by the following method. An optical microscope image of the toner dispersed on the slide glass is taken into a Luzex image analysis device through a video camera, and SF1 is obtained from the perimeter and projection area of 50 or more toners by the following formula, and an average value is obtained. is there.
SF1 = ML ² × 100π / 4A

  In the formula, ML represents the perimeter of the toner particles, and A represents the projected area of the particles.

The charge amount of the toner for developing an electrostatic image of the present invention is an absolute value, preferably in the range of 20 to 80 μC / g, and more preferably in the range of 25 to 35 μC / g. When the charge amount is within this range, background stains (fogging) are unlikely to occur, and a good image density can be obtained.
The ratio of the charge amount in the summer (high temperature and high humidity) of the electrostatic image developing toner to the charge amount in the winter (low temperature and low humidity) is preferably in the range of 0.5 to 1.5, and preferably in the range of 0.7 to 1.3. Is more preferable. Within this range, the charging property is less dependent on the environment and the charging stability is good, which is preferable.

  The glass transition point (Tg) of the toner of the present invention is preferably 50 to 65 ° C. More preferably, it is 52-60 degreeC. When the Tg is in the range of 50 to 65 ° C., the toner can be preferably used because it has good image durability such as toner storage stability and document offset.

  The toner of the present invention can be used in a method called a two-component developer comprising a toner and a carrier, in addition to being used in a usage method generally called a one-component developer having a charge imparting structure in a developing device. . The carrier is preferably a carrier coated with a resin using ferrite, iron powder or the like as a core agent. The core material (carrier core material) used is not particularly limited, and examples thereof include magnetic metals such as iron, steel, nickel and cobalt, magnetic oxides such as ferrite and magnetite, and glass beads. In the case of using the magnetic carrier, it is desirable to be a magnetic carrier. The average particle diameter of the carrier core material is preferably 3 to 10 times the toner volume average particle diameter.

  Examples of the coating resin include amino resins including acrylic resins, styrene resins, urea, urethane, melamine, guanamine, aniline, amide resins, and urethane resins. These copolymer resins may also be used. Two or more of the above resins may be used in combination as the coating resin for the carrier. For the purpose of controlling charging, binder resin fine particles, inorganic fine particles and the like may be dispersed in the coating resin.

  Examples of the method for forming the resin coating layer on the surface of the carrier core material include an immersion method in which a powder of the carrier core material is immersed in the solution for forming the coating layer, and a solution for forming the coating layer on the surface of the carrier core material. Spraying method for spraying, fluidized bed method for spraying the solution for forming the coating layer in a state where the carrier core material is floated by flowing air, and a kneader for mixing the carrier core material and the coating layer forming solution in a kneader coater to remove the solvent. Examples of the coater method include a powder coat method in which a coating resin is finely divided and mixed at a temperature equal to or higher than the melting point of the coating resin in a carrier core material and a kneader coater and cooled to form a coating. Among them, the kneader coater method and the powder coat method are particularly preferably used. .

  The amount of the resin coating formed by the above method is used by coating the carrier core material in an amount of 0.5 to 10% by mass. The mixing ratio (mass ratio) of the toner and the carrier is in the range of toner: carrier = 1: 100 to 30: 100, and more preferably in the range of 3: 100 to 20: 100.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these. In the examples, “parts” and “%” represent “parts by mass” and “%” unless otherwise specified.

  The toners of Examples and Comparative Examples were produced by the following method. That is, prepare the following binder resin particle dispersion, colorant particle dispersion, ester compound dispersion and release agent particle dispersion, respectively, and add a polymer of an inorganic metal salt while mixing and stirring a predetermined amount thereof. Then, it was ionically neutralized to form an aggregate of the above particles. After adjusting the pH of the system from a weakly acidic to a weakly alkaline range with an inorganic hydroxide, it was heated to a temperature equal to or higher than the glass transition point of the resin fine particles and heat-sealed. Thereafter, a desired toner was obtained through sufficient washing, solid-liquid separation, and drying processes. Specific examples of the method for preparing each material and the method for producing aggregated particles are shown below.

(Preparation of binder resin particle dispersion 1)
Ethylene glycol (Wako Pure Chemical Industries, Ltd.) 50 parts Neopentyl glycol (Wako Pure Chemical Industries, Ltd.) 65 parts Terephthalic acid (Wako Pure Chemical Industries, Ltd.) 96 parts

The monomer was charged into a flask, and the temperature was raised to 190 ° C. over 1 hour. After confirming that the inside of the reaction system was uniformly stirred, 1.2 parts of dibutyltin oxide was added. Further, while distilling off the water produced, the temperature was raised from the same temperature to 240 ° C. over 6 hours, and the dehydration condensation reaction was continued for an additional 4 hours at 240 ° C. to obtain a polyester resin having an acid value of 10.0 mgKOH / g. Obtained.
Subsequently, this was transferred in a molten state to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) at a rate of 100 g / min. A 0.37% diluted aqueous ammonia solution obtained by diluting reagent ammonia water with ion-exchanged water is put into a separately prepared aqueous medium tank, and the polyester is heated at 120 ° C. with a heat exchanger at a rate of 0.1 liter per minute. Simultaneously with the resin melt, it was transferred to the above-described Cavitron, and the Cavitron was operated under the conditions that the rotation speed of the rotor was 60 Hz and the pressure was 5 kg / cm ² to obtain a binder resin fine particle dispersion 1 having a solid content of 30%.
The weight average molecular weight, glass transition point, and volume average particle size were measured by the methods described respectively. The weight average molecular weight was 20000, the glass transition point was 60 ° C., and the volume average particle size was 160 nm.

(Preparation of binder resin particle dispersion 2)
(Oil layer)
Styrene (manufactured by Wako Pure Chemical Industries, Ltd.) 30 parts n-butyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.) 10 parts β-carboxyethyl acrylate (manufactured by Rhodia Nikka Co., Ltd.) 1.3 parts dodecanethiol (Wa 0.4 parts (Aqueous layer 1)
Ion-exchanged water 17 parts Anionic surfactant (Dowfax, manufactured by Dow Chemical) 0.4 part (Aqueous layer 2)
Deionized water 40 parts Anionic surfactant (Dowfax, manufactured by Dow Chemical) 0.05 part Ammonium peroxodisulfate (Wako Pure Chemical Industries, Ltd.) 0.4 part

The above oil layer component and water layer 1 component were placed in a flask and mixed with stirring to obtain a monomer emulsion dispersion. The components of the aqueous layer 2 were charged into the reaction vessel, the inside of the vessel was sufficiently replaced with nitrogen, and the reaction system was heated to 75 ° C. with an oil bath while stirring. The above monomer emulsified dispersion was gradually dropped into the reaction vessel over 3 hours to carry out emulsion polymerization. After completion of the dropping, the polymerization was further continued at 75 ° C., and the polymerization was terminated after 3 hours to obtain a binder resin particle dispersion 2 having a solid content of 42%.
The obtained binder resin particles had a volume average particle size of 200 nm, a glass transition point of 56 ° C., and a weight average molecular weight of 30000.

(Preparation of colorant particle dispersion)
Cyan pigment (Pigment Blue 15: 3, manufactured by Dainichi Seika Kogyo Co., Ltd.) 10 parts Anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 2 parts Ion-exchanged water 80 parts

  The above components were mixed and dispersed for 1 hour with a high-pressure impact disperser Ultimateizer (HJP30006, manufactured by Sugino Machine Co., Ltd.) to obtain a colorant particle dispersion having a volume average particle size of 180 nm and a solid content of 20%.

(Preparation of ester compound 1)
3,3′-thiodipropionic acid (manufactured by Wako Pure Chemical Industries, Ltd.) 105 parts 1,8-octanediol (manufactured by Wako Pure Chemical Industries, Ltd.) 73 parts

The above monomer was charged into a flask, and the temperature was raised to 160 ° C. over 1 hour. After confirming that the reaction system was uniformly stirred, 0.02 part of dibutyltin oxide was added. Further, while distilling off the water produced, the temperature was raised from the same temperature to 200 ° C. over 6 hours, and the dehydration condensation reaction was continued at 200 ° C. for another 4 hours to complete the reaction. After cooling the reaction solution, the solid obtained by solid-liquid separation was dried under vacuum at 40 ° C. to obtain ester compound 1.
When the melting point and the weight average molecular weight of the obtained ester compound 1 were measured by the method described, the melting point was 58 ° C. and the weight average molecular weight was 10,000.

(Preparation of ester compound 2)
3,3′-thiodipropionic acid (manufactured by Wako Pure Chemical Industries, Ltd.) 105 parts 1,10-decanediol (manufactured by Wako Pure Chemical Industries, Ltd.) 87 parts

The above monomer was charged into a flask, and the temperature was raised to 160 ° C. over 1 hour. After confirming that the reaction system was uniformly stirred, 0.02 part of dibutyltin oxide was added. Further, while distilling off the water produced, the temperature was raised from the same temperature to 200 ° C. over 6 hours, and the dehydration condensation reaction was continued at 200 ° C. for another 4 hours to complete the reaction. After cooling the reaction solution, the solid obtained by solid-liquid separation was dried under vacuum at 40 ° C. to obtain ester compound 2.
When the melting point and the weight average molecular weight of the resulting ester compound 2 were measured by the method described, the melting point was 60 ° C. and the weight average molecular weight was 10,000.

(Preparation of ester compound 3)
3,3′-thiodipropanol (Wako Pure Chemical Industries, Ltd.) 75 parts Octanedioic acid (Wako Pure Chemical Industries, Ltd.) 87 parts

The above monomer was charged into a flask, and the temperature was raised to 160 ° C. over 1 hour. After confirming that the reaction system was uniformly stirred, 0.02 part of dibutyltin oxide was added. Further, while distilling off the water produced, the temperature was raised from the same temperature to 200 ° C. over 6 hours, and the dehydration condensation reaction was continued at 200 ° C. for another 4 hours to complete the reaction. After cooling the reaction solution, the solid obtained by solid-liquid separation was dried under vacuum at 40 ° C. to obtain ester compound 3.
When the melting point and weight average molecular weight of the obtained ester compound 3 were measured by the method described, the melting point was 65 ° C. and the weight average molecular weight was 11,000.

(Preparation of ester compound 4)
3,3'-thiodipropanol (manufactured by Wako Pure Chemical Industries, Ltd.) 75 parts dodecanedioic acid (manufactured by Wako Pure Chemical Industries, Ltd.) 115 parts

The above monomer was charged into a flask, and the temperature was raised to 160 ° C. over 1 hour. After confirming that the reaction system was uniformly stirred, 0.02 part of dibutyltin oxide was added. Further, while distilling off the water produced, the temperature was raised from the same temperature to 200 ° C. over 6 hours, and the dehydration condensation reaction was continued at 200 ° C. for another 4 hours to complete the reaction. After cooling the reaction solution, the solid obtained by solid-liquid separation was dried under vacuum at 40 ° C. to obtain ester compound 4.
When the melting point and the weight average molecular weight of the obtained ester compound 4 were measured by the method described, the melting point was 68 ° C. and the weight average molecular weight was 10,000.

(Preparation of ester compound 5)
3,3′-dithiodipropionic acid (manufactured by Wako Pure Chemical Industries, Ltd.) 121 parts 1,10-decanediol (manufactured by Wako Pure Chemical Industries, Ltd.) 87 parts

The above monomer was charged into a flask, and the temperature was raised to 160 ° C. over 1 hour. After confirming that the reaction system was uniformly stirred, 0.03 part of dibutyltin oxide was added. Further, while distilling off the water produced, the temperature was raised from the same temperature to 200 ° C. over 6 hours, and the dehydration condensation reaction was continued at 200 ° C. for another 4 hours to complete the reaction. After cooling the reaction solution, the solid obtained by solid-liquid separation was dried under vacuum at 40 ° C. to obtain ester compound 5.
When the melting point and the weight average molecular weight of the obtained ester compound 5 were measured by the method described, the melting point was 58 ° C. and the weight average molecular weight was 10,000.

(Preparation of ester compound 6)
3,3′-dithiodipropanol (manufactured by Wako Pure Chemical Industries, Ltd.) 91 parts dodecanedioic acid (manufactured by Wako Pure Chemical Industries, Ltd.) 115 parts

The above monomer was charged into a flask, and the temperature was raised to 160 ° C. over 1 hour. After confirming that the reaction system was uniformly stirred, 0.02 part of dibutyltin oxide was added. Further, while distilling off the water produced, the temperature was raised from the same temperature to 200 ° C. over 6 hours, and the dehydration condensation reaction was continued at 200 ° C. for another 4 hours to complete the reaction. After cooling the reaction liquid, the solid obtained by solid-liquid separation was dried under vacuum at 40 ° C. to obtain ester compound 6.
When the melting point and weight average molecular weight of the obtained ester compound 6 were measured by the method described, the melting point was 60 ° C. and the weight average molecular weight was 9000.

(Preparation of ester compound 7)
3,3′-thiodipropionic acid (manufactured by Wako Pure Chemical Industries, Ltd.) 105 parts 1,9-nonanediol (manufactured by Wako Pure Chemical Industries, Ltd.) 80 parts

The above monomer was charged into a flask, and the temperature was raised to 160 ° C. over 1 hour. After confirming that the reaction system was uniformly stirred, 0.02 part of dibutyltin oxide was added. Further, while distilling off the water produced, the temperature was raised from the same temperature to 200 ° C. over 6 hours, and the dehydration condensation reaction was continued at 200 ° C. for another 4 hours to complete the reaction. After cooling the reaction solution, the solid obtained by solid-liquid separation was dried under vacuum at 40 ° C. to obtain ester compound 7.
When the melting point and the weight average molecular weight of the obtained ester compound 7 were measured by the method described, the melting point was 68 ° C. and the weight average molecular weight was 10,000.

(Preparation of ester compound 8)
3,3'-thiodipropanol (Wako Pure Chemical Industries, Ltd.) 75 parts Undecanedioic acid (Tokyo Chemical Industry Co., Ltd.) 108 parts

The above monomer was charged into a flask, and the temperature was raised to 160 ° C. over 1 hour. After confirming that the reaction system was uniformly stirred, 0.02 part of dibutyltin oxide was added. Further, while distilling off the water produced, the temperature was raised from the same temperature to 200 ° C. over 6 hours, and the dehydration condensation reaction was continued at 200 ° C. for another 4 hours to complete the reaction. After cooling the reaction solution, the solid obtained by solid-liquid separation was dried under vacuum at 40 ° C. to obtain ester compound 8.
When the melting point and the weight average molecular weight of the obtained ester compound 8 were measured by the method described, the melting point was 70 ° C. and the weight average molecular weight was 11,000.

(Preparation of ester compound 9)
3,3′-thiodipropionic acid (manufactured by Wako Pure Chemical Industries, Ltd.) 105 parts 1,8-octanediol (manufactured by Wako Pure Chemical Industries, Ltd.) 73 parts

The above monomer was charged into a flask, and the temperature was raised to 160 ° C. over 1 hour. After confirming that the reaction system was uniformly stirred, 0.02 part of dibutyltin oxide was added. Further, while distilling off the water produced, the temperature was raised from the same temperature to 200 ° C. over 6 hours, and the dehydration condensation reaction was continued at 200 ° C. for another 2 hours to complete the reaction. After cooling the reaction solution, the solid obtained by solid-liquid separation was dried under vacuum at 40 ° C. to obtain ester compound 9.
When the melting point and the weight average molecular weight of the obtained ester compound 3 were measured by the method described, the melting point was 56 ° C. and the weight average molecular weight was 3000.

(Preparation of ester compound 10)
3,3′-thiodipropionic acid (manufactured by Wako Pure Chemical Industries, Ltd.) 105 parts 1,8-octanediol (manufactured by Wako Pure Chemical Industries, Ltd.) 73 parts

The above monomer was charged into a flask, and the temperature was raised to 160 ° C. over 1 hour. After confirming that the reaction system was uniformly stirred, 0.02 part of dibutyltin oxide was added. Further, the temperature was raised from the same temperature to 200 ° C. over 6 hours while distilling off the generated water, and the dehydration condensation reaction was continued at 200 ° C. for another 8 hours to complete the reaction. After cooling the reaction solution, the solid obtained by solid-liquid separation was dried under vacuum at 40 ° C. to obtain ester compound 10.
When the melting point and the weight average molecular weight of the obtained ester compound 10 were measured by the method described, the melting point was 59 ° C. and the weight average molecular weight was 35,000.

(Preparation of ester compound 11)
Dodecanedioic acid (manufactured by Wako Pure Chemical Industries, Ltd.) 115 parts 1,12-dodecanediol (manufactured by Ube Industries, Ltd.) 101 parts

The above monomer was charged into a flask, and the temperature was raised to 160 ° C. over 1 hour. After confirming that the reaction system was uniformly stirred, 0.02 part of dibutyltin oxide was added. Further, while distilling off the water produced, the temperature was increased from the same temperature to 220 ° C. over 3 hours, and the dehydration condensation reaction was continued at 220 ° C. for another 6 hours to complete the reaction. After cooling the reaction solution, the solid obtained by solid-liquid separation was dried under vacuum at 40 ° C. to obtain ester compound 11.
When the melting point and the weight average molecular weight of the obtained ester compound 3 were measured by the method described, the melting point was 82 ° C. and the weight average molecular weight was 2000.

(Preparation of ester compound 12)
Octanedioic acid (manufactured by Wako Pure Chemical Industries, Ltd.) 87 parts 1,10-decandiol (manufactured by Wako Pure Chemical Industries, Ltd.) 87 parts

The above monomer was charged into a flask, and the temperature was raised to 160 ° C. over 1 hour. After confirming that the reaction system was uniformly stirred, 0.02 part of dibutyltin oxide was added. Further, while distilling off the water produced, the temperature was increased from the same temperature to 190 ° C. over 3 hours, and the dehydration condensation reaction was continued at 190 ° C. for further 4 hours to complete the reaction. After cooling the reaction solution, the solid obtained by solid-liquid separation was dried under vacuum at 40 ° C. to obtain ester compound 12.
When the melting point and the weight average molecular weight of the obtained ester compound 12 were measured by the method described, the melting point was 68 ° C. and the weight average molecular weight was 2000.

(Preparation of ester compound dispersion 1)
Ester compound 1 50 parts Anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 2 parts Ion-exchanged water 200 parts

  The above components were heated to 120 ° C. and sufficiently dispersed with IKE Co., Ltd. Ultra Turrax T50, and then dispersed with a pressure discharge type homogenizer, and collected when the volume average particle size reached 180 nm. Thus, a binder resin particle dispersion 1 having a solid content of 20% was obtained.

(Preparation of ester compound dispersions 2 to 12)
Instead of ester compound 1, ester compounds 2-12 were used, and ester compound dispersions 2-12 were obtained in the same manner. The volume average particle diameter of each dispersion was 180 nm, and the solid content was 20%.

(Preparation of release agent particle dispersion)
Paraffin wax (HNP-9 manufactured by Nippon Seiki Co., Ltd.) 50 parts Anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 2 parts Ion-exchanged water 200 parts

  The above components are heated to 120 ° C. and sufficiently dispersed with IKE Ultra Turrax T50, and then dispersed with a pressure discharge type homogenizer, and a release agent particle dispersion having a volume average particle size of 200 nm and a solid content of 20%. Got.

[Example 1]
(Manufacture of toner 1)
Binder resin particle dispersion 1 150 parts Colorant particle dispersion 20 parts Ester compound dispersion 1 45 parts Release agent particle dispersion 25 parts Polyaluminum chloride 0.4 parts Ion exchange water 100 parts

  The above components were thoroughly mixed and dispersed in a round stainless steel flask using IKE Ultra Turrax T50, and then heated to 48 ° C. while stirring the flask in a heating oil bath. After maintaining at 48 ° C. for 60 minutes, 70 parts of the same binder resin particle dispersion 1 as above was slowly added (added).

  Then, after adjusting the pH in the system to 8.0 using an aqueous solution of sodium hydroxide having a concentration of 0.5 mol / L (pH adjustment), the stainless steel flask was sealed, and the stirring shaft seal was magnetically sealed and stirred. Was continued and heated to 94 ° C. and held for 3 hours. After completion of the reaction, the temperature lowering rate was cooled at 2 ° C./min, filtered, sufficiently washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed with 3 L of ion exchange water at 30 ° C., and stirred and washed at 300 rpm for 15 minutes. This washing operation was further repeated 6 times, and when the pH of the filtrate became 7.54 and the electric conductivity was 6.5 μS / cm, No. was obtained by Nutsche suction filtration. Solid-liquid separation was performed using 5A filter paper. Next, vacuum drying was continued for 12 hours to obtain a toner.

The volume average particle diameter D50v of Toner 1 was measured by Coulter Counter TA-II by the method described, and found to be 5.5 μm, and the volume average particle size distribution index GSDv was 1.22. Further, this toner was subjected to surface hydrophobization treatment with hexamethyldisilazane, silica (SiO ₂ ) fine particles having an average primary particle size of 40 nm, and an average primary particle size of 20 nm, which is a reaction product of metatitanic acid and isobutyltrimethoxysilane. The metatitanic acid compound fine particles were added so that the coverage of the colored particles on the surface was 40%, and mixed with a Henschel mixer to prepare an electrostatic charge image developing toner 1.

≪Evaluation≫
-Image strength (rubbing test)-
The image strength of the manufactured toner was confirmed by the following rubbing test.
In the test, DocuCenterColor400 (Fuji Xerox Co., Ltd.) was used, and the toner load was adjusted to 1.2 g / m ^2, and a solid surface of 5 × 5 cm was drawn on Fuji Xerox Co. J paper. I did it. Next, fixing was performed at an Nip width of 6.5 mm and a fixing speed of 90 mm / sec using an external fixing device without an oil supply device. The fixing temperature was controlled by the surface temperature of the fixing roll, and 100 ° C. was set as the set temperature.
Next, the obtained image was installed in a surface property measuring instrument tribogear 14DR manufactured by Shinto Kagaku Co., Ltd., and a 30 mm flat indenter was used as a measurement jig. The rubbing test was performed 10 times with a vertical load of 2000 g. Cotton Kanakin No. 3 where no transfer was observed, △ if there was a slight color transfer, × if there was a clear color transfer, and if there was a defect in the image due to severe color transfer. XX.
In addition, the above test was performed in an environment of 30 ° C. and 88% RH from the image printing to the rubbing test.

-Fixability (bending test)-
The fixability of the manufactured toner was confirmed by an image defect at a fixing temperature of 90 ° C.
The test was carried out using DocuCenterColor400 (Fuji Xerox Co., Ltd.) to adjust the toner applied amount to 0.6 g / m ² , and then using an external fixing device without an oil supply device, the Nip width was 6.5 mm. Fixing was performed at a fixing speed of 90 mm / sec. The fixing temperature was controlled by the surface temperature of the fixing roll, and 90 ° C. was set as the set temperature.
After fixing the fixed image as a solid of 25 mm x 25 mm, it is bent using a weight with a constant load, and the part where there is no image defect is ○, the part slightly missing on the streak is △, and the bent part is largely missing What to do was marked with x.

-Fixability (offset)-
In the bending test, image transfer (offset) due to fixing was also confirmed at the same time. A case where there was no offset was indicated as ◯, a case where a slight offset occurred, and a case where offset occurred.

[Example 2]
A toner 2 was obtained in exactly the same manner as in Example 1 except that the ester compound dispersion 1 was changed to 10 parts. The volume average particle diameter D50v of the toner 2 is measured to be 5.5 μm and the volume average particle size distribution index GSDv is 1.21.
The obtained toner was subjected to the same evaluation test as in Example 1.

Example 3
A toner 3 was obtained in exactly the same manner as in Example 1 except that the ester compound dispersion 1 was changed to 80 parts. The volume average particle diameter D50v of the toner 3 was measured and found to be 5.4 μm and the volume average particle size distribution index GSDv was 1.22.
The obtained toner was subjected to the same evaluation test as in Example 1.

Example 4
In Example 1, instead of using the ester compound dispersion 1, a toner 4 was obtained in exactly the same manner except that the same part of the ester compound dispersion 2 was used. The volume average particle diameter D50v of the toner 4 was measured and found to be 5.6 μm and the volume average particle size distribution index GSDv was 1.21.
The obtained toner was subjected to the same evaluation test as in Example 1.

Example 5
In Example 1, instead of using the ester compound dispersion 1, a toner 5 was obtained in exactly the same manner except that the same part of the ester compound dispersion 3 was used. The volume average particle diameter D50v of the toner 5 was measured and found to be 5.4 μm and the volume average particle size distribution index GSDv was 1.22.
The obtained toner was subjected to the same evaluation test as in Example 1.

Example 6
In Example 1, instead of using the ester compound dispersion 1, a toner 6 was obtained in exactly the same manner except that the same part of the ester compound dispersion 4 was used. The volume average particle diameter D50v of the toner 6 is measured to be 5.5 μm and the volume average particle size distribution index GSDv is 1.22.
The obtained toner was subjected to the same evaluation test as in Example 1.

Example 7
In Example 1, instead of using the ester compound dispersion 1, a toner 7 was obtained in exactly the same manner except that the same part of the ester compound dispersion 5 was used. The volume average particle diameter D50v of the toner 7 is measured to be 5.5 μm and the volume average particle size distribution index GSDv is 1.22.
The obtained toner was subjected to the same evaluation test as in Example 1.

Example 8
In Example 1, instead of using the ester compound dispersion 1, a toner 8 was obtained in exactly the same manner except that the same part of the ester compound dispersion 6 was used. The volume average particle diameter D50v of the toner 8 is measured and found to be 5.4 μm and the volume average particle size distribution index GSDv is 1.22.
The obtained toner was subjected to the same evaluation test as in Example 1.

Example 9
In Example 1, instead of using the binder resin particle dispersion 1, 110 parts of the binder resin particle dispersion 2 was used, and the binder resin particle dispersion added after being held at 48 ° C. for 60 minutes (additional) The toner 9 was obtained in exactly the same manner except that the pH was adjusted to 6.0 when the pH was adjusted to 50 parts at 50 parts and heated to 94 ° C. and held for 3 hours. The volume average particle diameter D50v of the toner 9 was measured and found to be 5.6 μm and the volume average particle size distribution index GSDv was 1.22.
The obtained toner was subjected to the same evaluation test as in Example 1.

[Comparative Example 1]
In Example 1, instead of using the ester compound dispersion 1, a toner 10 was obtained in exactly the same manner except that the same part of the ester compound dispersion 7 was used. The volume average particle diameter D50v of the toner 10 is measured to be 5.5 μm and the volume average particle size distribution index GSDv is 1.21.
The obtained toner was subjected to the same evaluation test as in Example 1.

[Comparative Example 2]
In Example 1, instead of using the ester compound dispersion 1, a toner 11 was obtained in exactly the same manner except that the same part of the ester compound dispersion 8 was used. The volume average particle diameter D50v of the toner 11 is measured to be 5.5 μm and the volume average particle size distribution index GSDv is 1.22.
The obtained toner was subjected to the same evaluation test as in Example 1.

[Comparative Example 3]
In Example 1, instead of using the ester compound dispersion 1, a toner 12 was obtained in exactly the same manner except that the same part of the ester compound dispersion 9 was used. The volume average particle diameter D50v of the toner 12 was measured and found to be 5.2 μm and the volume average particle size distribution index GSDv was 1.22.
The obtained toner was subjected to the same evaluation test as in Example 1.

[Comparative Example 4]
In Example 1, instead of using the ester compound dispersion 1, a toner 13 was obtained in exactly the same manner except that the same part of the ester compound dispersion 10 was used. The volume average particle diameter D50v of the toner 13 was measured and found to be 5.4 μm and the volume average particle size distribution index GSDv was 1.22.
The obtained toner was subjected to the same evaluation test as in Example 1.

[Comparative Example 5]
In Example 1, instead of using the ester compound dispersion 1, a toner 14 was obtained in exactly the same manner except that the same part of the ester compound dispersion 11 was used. The volume average particle diameter D50v of the toner 14 was measured and found to be 5.6 μm and the volume average particle size distribution index GSDv was 1.22.
The obtained toner was subjected to the same evaluation test as in Example 1.

[Comparative Example 6]
In Example 1, instead of using the ester compound dispersion 1, a toner 15 was obtained in exactly the same manner except that the same part of the ester compound dispersion 12 was used. The volume average particle diameter D50v of the toner 14 was measured and found to be 5.4 μm and the volume average particle size distribution index GSDv was 1.22.
The obtained toner was subjected to the same evaluation test as in Example 1.

  The ester compounds used in the toners obtained in the above examples and comparative examples are summarized in Table 1 below, and the evaluation results are shown in Table 2 below.

Claims (8)

A toner for developing electrostatic images comprising a binder resin, a colorant and an ester compound, wherein the ester compound is obtained by reacting a dicarboxylic acid containing a sulfur atom with an aliphatic dialcohol containing no sulfur atom. The toner for developing an electrostatic charge image, wherein the aliphatic dialcohol has an even number of carbon atoms and the ester compound has a weight average molecular weight of 5,000 to 12,000. A toner for developing electrostatic images comprising a binder resin, a colorant and an ester compound, wherein the ester compound is obtained by reacting a dialcohol containing a sulfur atom with an aliphatic dicarboxylic acid containing no sulfur atom. An electrostatic charge image developing toner, wherein the aliphatic dicarboxylic acid has an even number of carbon atoms, and the ester compound has a weight average molecular weight of 5,000 to 12,000. A dispersion step of dispersing binder resin particles, colorant particles and ester compound particles in an aqueous dispersion medium, an aggregation step of aggregating the dispersed particles with metal ions to form aggregated particles, and heat-sealing the aggregated particles A process for producing a toner for developing an electrostatic charge image, comprising:
As the ester compound particles, a dicarboxylic acid containing a sulfur atom is reacted with an aliphatic dialcohol not containing a sulfur atom, the aliphatic dialcohol has an even number of carbon atoms, and the weight average molecular weight is 5,000 to 12,000. A method for producing a toner for developing an electrostatic charge image, wherein the ester compound particles are: A dispersion step of dispersing binder resin particles, colorant particles and ester compound particles in an aqueous dispersion medium, an aggregation step of aggregating the dispersed particles with metal ions to form aggregated particles, and heat-sealing the aggregated particles A process for producing a toner for developing an electrostatic charge image, comprising:
The ester compound particles are prepared by reacting a dialcohol containing a sulfur atom with an aliphatic dicarboxylic acid not containing a sulfur atom , wherein the aliphatic dicarboxylic acid has an even number of carbon atoms and has a weight average molecular weight of 5000 to 12000. A method for producing a toner for developing an electrostatic charge image, wherein the ester compound particles are:   An electrostatic charge image developing developer comprising the electrostatic charge image developing toner according to claim 1.   An electrostatic charge image developing developer comprising the electrostatic charge image developing toner according to claim 2. A developing step of developing the electrostatic latent image formed on the latent image carrier with a developer for developing an electrostatic image containing toner to form a toner image, and transferring the toner image onto a transfer medium to transfer the image An image forming method comprising: a transfer step of forming a fixing step; and a fixing step of fixing the transferred image,
An image forming method, wherein the developer for developing an electrostatic image is the developer for developing an electrostatic image according to claim 5. A developing step of developing the electrostatic latent image formed on the latent image carrier with a developer for developing an electrostatic image containing toner to form a toner image, and transferring the toner image onto a transfer medium to transfer the image An image forming method comprising: a transfer step of forming a fixing step; and a fixing step of fixing the transferred image,
The image forming method according to claim 6, wherein the developer for developing an electrostatic image is the developer for developing an electrostatic image according to claim 6.