JP2000347449A - Manufacture of electrostatic charge image developing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner especially superior in chargeing stability. SOLUTION: The method for manufacturing the electrostatic charge image developing toner comprises at least both of a condensing process for forming condensed particles in a dispersion liquid obtained by dispersing at least primary resin particles and colorant particles and a heat granulating process for heat- melting the condensed particles to form the toner particles, and a charge controller is added after 1 hr from the beginning of the condensing process to the end of it or after the lapse of 1/10 of the total time length of the condensing process till the end of this process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an electrostatic image developing toner used in an electrophotographic copying machine and a printer. More specifically, the present invention relates to a method for producing a toner for developing an electrostatic image, which is particularly excellent in charge stability, excellent in fixing property, anti-offset property and anti-blocking property and excellent in OHP transparency of an obtained image.

[0002]

2. Description of the Related Art Toners for electrostatic charge development, which have been widely and generally used in electrophotography, include a styrene / acrylate copolymer, a colorant such as carbon black or a pigment, a charge control agent and / or a magnetic material. Has been produced by melt-kneading a mixture containing, and then pulverizing and classifying. However, the melt kneading /
The conventional toner obtained by the pulverization method has a limit in controlling the particle size of the toner, and it is difficult to produce a toner having an average particle size of substantially 10 μm or less, particularly 8 μm or less with a high yield, and will be used in electrophotography in the future. It was not enough to achieve the required high resolution.

In addition, low-temperature fixability is required for toners from the viewpoint of reducing energy consumption. To achieve this, a method has been proposed in which a wax having a low softening point is blended into the toner during kneading. However, in the kneading / pulverization method, the blending of about 4 to 5 parts with respect to 100 parts of the resin is the limit, and a toner having sufficient low-temperature fixing performance cannot be obtained. JP-A-63-186253 proposes a method for producing a toner by an emulsion polymerization / two-stage aggregation method in order to overcome the problems of particle size and particle size distribution control and achieve high resolution. However, even in this method, the amount of wax that can be introduced in the aggregation step is limited, and a sufficient improvement effect on low-temperature fixability has not been obtained. That is, based on the patent, the present inventors examined the amount of added wax, and as the amount of added wax was increased, the particle size distribution of the obtained toner became two peaks or 1 μm or less. There is a problem that fine powder remains, and a classification step is required after the aggregation step. The method disclosed in JP-A-6-329947 is a method capable of obtaining aggregated particles having a narrow particle size distribution by adding an organic solvent which is infinitely soluble in water at the same time as an aggregating agent in an aggregating step. However, there were problems such as poor reproducibility due to many control factors and a heavy burden on wastewater treatment. Further, a technique relating to control of the charging property of the obtained toner has not been disclosed yet.

[0004]

DISCLOSURE OF THE INVENTION The present invention overcomes the drawbacks of the conventionally used toner for developing electrostatic images, and in particular, has excellent charge stability and satisfies high resolution, low-temperature fixability and offset resistance. It is an object of the present invention to provide a method for manufacturing a new toner at low cost.

[0005]

Means for Solving the Problems As a result of intensive studies on the above-mentioned problems, the present inventors have found that the charge control during the aggregation step of forming aggregated particles in a dispersion liquid in which resin particles and colorant particles are dispersed. The present inventors have found that the above problems can be solved by adding an agent, and have reached the present invention. That is, the gist of the present invention is (1) an aggregation step of forming aggregated particles in a dispersion obtained by dispersing at least the resin primary particles and the colorant particles, and (2) melting the aggregated particles by heating. Heating granulation step of forming toner particles by attaching, in the method of manufacturing a toner for electrostatic image development including both steps,

After one hour from the start of the aggregating step, a charge controlling agent is added until the end of the aggregating step, or after 1/10 of the time from the start to the end of the aggregating step, and before the end of the aggregating step. And (1) a dispersion obtained by dispersing at least resin primary particles and colorant particles, and further containing 100 parts by weight of a polymer solid content. 0.01 parts of electrolyte-10
An aggregation step of adding 0 parts to form a mixed dispersion to form secondary particles, and then heating to form aggregated particles; (2) heating and agglomerating the aggregated particles to form toner particles by heating and fusing; A method for producing a toner for developing an electrostatic image, comprising the steps of: adding a charge control agent before the completion of the aggregation step after the addition of the electrolyte; Exist.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The form of the primary resin particles used in the present invention may be basically any dispersion liquid dispersed in water. The dispersion dispersed in water is obtained by dispersing the resin as particles having a size of 3 μm or less at maximum using an emulsifier or the like as necessary. The average particle size of the resin primary particles is 1 μm
Or less, more preferably 0.8 μm or less, particularly 0.5 μm or less.
Those having a particle size of not more than μm are preferably used. The particle size distribution and the average particle size can be measured, for example, using a Microtrack UPA manufactured by Nikkiso Co., Ltd. If the primary resin particles have a particle size of 3 μm or more, it becomes difficult to produce a small particle size toner having a uniform particle size distribution in the aggregation step. When the average particle size is larger than 1 μm, the obtained toner is not suitable for toner use because the shape of the obtained toner is poor and additives such as a colorant and a charge control agent become uneven.

As the resin, polyester, styrene /
An acrylate copolymer, polyurethane, or the like is used. Among them, polyester and styrene / acrylate copolymers are preferred. In the case of polyester, the polymerized polyester may be used as a resin dispersion using an emulsifier or the like. In the case of a styrene / acrylate copolymer, emulsion polymerization is performed, and this dispersion can be used as it is in the next step. . At this time, the glass transition temperature of the polymer was 40.
~ 80 ° C is preferred. Glass transition temperature 80
If the temperature exceeds 100 ° C., the fixing temperature may become too high, or the OHP transparency may deteriorate. On the other hand, if the glass transition temperature of the polymer is lower than 40 ° C., the storage stability of the toner becomes too poor. May cause problems.

When a resin is used as a dispersion by using an emulsifier,
It can be obtained by emulsification in the presence of at least one emulsifier selected from known cationic surfactants, anionic surfactants, and nonionic surfactants. Two or more of these surfactants may be used in combination. Specific examples of the cationic surfactant include dodecyl ammonium chloride, dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide, and the like. Specific examples of the anionic surfactant include fatty acid soaps such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, and sodium lauryl sulfate. Further, as a specific example of a nonionic surfactant,
Dodecyl polyoxyethylene ether, hexadecyl polyoxyethylene ether, nonylphenyl polyoxyethylene ether, lauryl polyoxyethylene ether, sorbitan monooleate polyoxyethylene ether, monodecanoyl sucrose, and the like.

In the case of a styrene / acrylate copolymer, emulsion polymerization is carried out, and this dispersion can be used as it is in the next step. As the monomers to be used, styrenes such as styrene, methylstyrene, chlorostyrene, dichlorostyrene, p-tert-butylstyrene, pn-butylstyrene, pn-nonylstyrene, etc., methyl acrylate, ethyl acrylate, Propyl acrylate, n-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, hydroxyethyl methacrylate, (Meth) acrylic acid esters such as ethylhexyl methacrylate and the like. Among them, styrene, butyl acrylate and the like are particularly preferred.

Further, a monomer having an acidic polar group or a basic polar group may be copolymerized. Examples of the monomer having an acidic polar group include monomers having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, and cinnamic acid, and monomers having a sulfonic acid group such as sulfonated styrene. In addition, as the monomer having a basic polar group, a nitrogen-containing heterocyclic-containing monomer such as aminostyrene and a quaternary salt thereof, vinylpyridine and vinylpyrrolidone, and an amino group such as dimethylaminoethyl acrylate and diethylaminoethyl methacrylate (Meth) acrylic acid esters and (meth) acrylic acid esters having quaternary ammonium salts of these amino groups, furthermore, acrylamide, N
-Propylacrylamide, N, N-dimethylacrylamide, N, N-dipropylacrylamide, N, N-
Examples thereof include dibutyl acrylamide and acrylamide.

As the emulsifier, one or a combination of two or more of the above emulsifiers is selected. Further, in order to satisfy the low-temperature fixability and the offset resistance, it is preferable to add a wax or the like. The wax may be dispersed in advance to form an emulsion and added in the coagulation step, but it is particularly preferable to subject the wax to the seed polymerization of the resin during the emulsion polymerization. As the wax, any known wax can be used, and specific examples thereof include low-molecular-weight polyethylene, low-molecular-weight polypropylene, olefin-based waxes such as copolymerized polyethylene, paraffin wax, behenyl behenate, and montanic acid ester. Ester wax having long-chain aliphatic group such as stearyl stearate, vegetable wax such as hydrogenated castor oil, carnauba wax, ketone having long-chain alkyl group such as distearyl ketone, silicone having alkyl group, stearic acid Higher fatty acids such as
Examples thereof include long-chain fatty acid alcohols, polyhydric alcohols of long-chain fatty acids such as pentaerythritol, and partial esters thereof, higher fatty acid amides such as oleamide and stearamide.

Among these waxes, those having a melting point of 100 ° C. or less are more preferable in order to improve the fixing property, and the melting point of the wax is more preferably 40 to 90 ° C.
Is particularly preferable in the range of 50 to 80 ° C.
If the melting point exceeds 100 ° C., the effect of lowering the fixing temperature becomes poor. Further, in the present invention, when obtaining the primary resin particles, the pigment may be used as a seed simultaneously with the wax, or the colorant may be used by dissolving or dispersing it in the monomer or the wax. At the same time, it is preferable that the colorant particles are aggregated to form associated particles to form a toner. At this time, two or more types of resin primary particles may be used as necessary.

The colorant particles used here may be any of inorganic pigments, organic pigments, organic dyes, or a combination thereof. Specific examples of these include carbon black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow, rhodamine dyes, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane dyes, monoazo dyes, disazo dyes Any known dyes and pigments, such as dyes and condensed azo dyes, can be used alone or in combination. In the case of a full-color toner, it is preferable to use benzidine yellow, monoazo-based and condensed azo-based dyes and pigments for yellow, quinacridone and monoazo-based dyes and pigments for magenta, and phthalocyanine blue for cyan, respectively. The colorant is usually used in an amount of 3 to 20 parts by weight based on 100 parts by weight of the binder resin.

These colorants are also emulsified in water in the presence of an emulsifier and are used in the form of an emulsion. The average particle size is preferably 0.01 to 3 μm. In the present invention, the aggregated particles are formed in a dispersion liquid in which the resin primary particles and the colorant particles are dispersed. After one hour has elapsed since the step of forming the aggregated particles (aggregation step) is started, or The method is characterized in that the charge control agent is added after 1/10 of the time from the start to the end of the step of forming aggregated particles and before the end of the aggregation step. In the step of forming aggregated particles (aggregation step), the resin primary particles and at least the colorant particles are mixed, stirred at about room temperature for 0.5 to 2 hours, homogenized, and then slowly until around the Tg of the resin. Alternatively, it refers to a step of raising the temperature in a stepwise manner and keeping the particle size at a target level until the particle size becomes stable. The charge control agent is added at least during this step after the stage of homogenization near room temperature and the start of temperature rise and before the stage of maintaining the temperature near Tg.

When the charge control agent is added from the beginning of the aggregation step, the charge control agent is more distributed inside the toner particles and does not exhibit good chargeability. On the other hand, when a charge control agent is added in the next step of forming aggregated particles, that is, the step of heating and fusing the aggregated particles to form toner particles (heating granulation step), the charge control agent particles are added to the toner. It does not take up much and still does not show good chargeability. As for the method of addition, they may be added all at once, may be added gradually, or may be added in several stages. In this case, the charge control agent is also used as an emulsion having an average particle size of 0.01 to 3 μm in water. By adding the charge control agent after the resin primary particles and the colorant particles, the charge control agent is distributed on the more surface of the toner, and good chargeability is obtained.
Stable chargeability is obtained. In particular, the effect is remarkable in the non-magnetic one-component system.

The charge control agent is added in an amount of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, per 100 parts of the resin.
Parts, more preferably 0.1 to 2 parts by weight. In the present invention, as a coagulation step of forming coagulated particles in a dispersion liquid in which primary resin particles and colorant particles are dispersed, a polymer in which the resin primary particles and colorant particles are dispersed is further added to the dispersion. 0.01 part of electrolyte per 100 parts of solid content-100
After the addition, the secondary particles are formed into a mixed dispersion by adding a charge controlling agent, and the mixture is heated to form aggregated particles. By adding the electrolyte, it is possible to produce a toner having a smaller particle size and a sharp particle size distribution. In this case, the charge control agent is added after completion of the addition of the electrolyte and before heating and maintaining the temperature around Tg.

The electrolyte used in the present invention is an organic
Either a salt or an inorganic salt may be used.
Alternatively, a bivalent or higher polyvalent metal salt is preferably used. This
Specific examples of such salts include NaCl, KCl, LiC
1, Na_TwoSO_Four, K_TwoSO_Four, Li_TwoSO_Four, MgC
l_Two, CaCl_Two, MgSO_Four, CaSO_Four, ZnSO
_Four, Al_Two(SO_Four)_Three, Fe_Two(SO_Four)_Three, Etc.
I can do it. When adding the electrolyte,
Preferably, the temperature is kept below 40 ° C., more preferably
Is a temperature range of 30 ° C. or lower, more preferably 20 ° C. or lower.
It is preferable to add the electrolyte while maintaining the temperature range. Temperature 40
Rapid aggregation occurs when electrolytes are added above ℃
Particle size control becomes difficult, and the obtained particles
May be problematic at low degrees.

The average particle size of the mixed dispersion obtained after adding the electrolyte is usually preferably 3 μm or less, more preferably 2 μm or less, and further preferably 1 μm or less. When the average particle diameter exceeds 3 μm, the shape of the aggregated particles aggregated in the next step becomes a tuft of grapes, and the strength of the obtained toner deteriorates, which is a problem. By adding the charge control agent after the addition of the electrolyte, the charge control agent is distributed on the surface of the particles aggregated by the electrolyte, so that good chargeability and stable chargeability can be obtained. Any known charge control agent can be used alone or in combination. Considering the color toner adaptability (the charge control agent itself is colorless or light color and there is no color hindrance to the toner), a quaternary ammonium salt compound is used as the positive charge, and chromium of salicylic acid or alkyl salicylic acid is used as the negative charge. , Zinc, metal salts and metal complexes with aluminum, metal salts of benzylic acid, metal complexes, amide compounds,
Phenol compounds, naphthol compounds, phenolamide compounds and the like are preferred. The amount used may be determined depending on the desired charge amount of the toner.
The amount is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, more preferably 0.1 to 2 parts by weight, per 100 parts by weight.

The aggregated particles obtained as described above are heated and fused to form toner particles. The heating temperature in this step is usually in the range of (Tg + 20 ° C.) to (Tg + 80 ° C.). Usually, the fusion between the particles proceeds further during the heating granulation step, and the shape of the toner particles can be rounded, and the shape can be controlled as necessary. The time for the heating granulation step is usually 1 hour to 24 hours, preferably 2 hours to 10 hours.

In producing the toner of the present invention,
After the particle size of the aggregated particles has substantially grown to the final particle size of the toner, the same or a different type of binder resin emulsion is further added, and the particles are attached to the surface to improve the toner properties near the surface. It is also possible to modify. Further, the toner of the present invention can be used together with additives such as a fluidizing agent, if necessary. As such a fluidizing agent, specifically, hydrophobic silica, titanium oxide,
Fine powders such as aluminum oxide can be used. Usually, 0.01 to 100 parts by weight of the binder resin is used.
5 parts by weight, preferably 0.1 to 3 parts by weight is used.

Further, the toner of the present invention contains an inorganic additive such as magnetite, ferrite, cerium oxide, strontium titanate, and conductive titania; a resistance modifier such as styrene resin and acrylic resin; Used as an additive. The amount of these additives used may be appropriately selected depending on the desired performance, and usually about 0.05 to 10 parts by weight per 100 parts by weight of the binder resin is suitable. The toner for developing an electrostatic image of the present invention may be used in any form of a two-component developer or a non-magnetic one-component developer. In particular, the non-magnetic one-component system shows good chargeability and charge stability, and its effect is remarkable. When used as a two-component developer, the carrier may be a magnetic substance such as iron powder, magnetite powder, or ferrite powder, or a carrier whose surface is coated with a resin, or a known carrier such as a magnetic carrier. As the coating resin for the resin-coated carrier, generally known styrene resins, acrylic resins, styrene-acryl copolymer resins, silicone resins, modified silicone resins, fluororesins, and mixtures thereof can be used.

[0023]

The present invention will be specifically described below with reference to examples. In the following examples, “parts” means “parts by weight”. The average particle size and molecular weight of the polymer particles were measured by the following methods. Average particle size: It was measured by Microtrac UPA manufactured by Nikkiso Co., Ltd. or Coulter Counter Multisizer II manufactured by Coulter Co., Ltd.

Charge amount: 10 g of the obtained toner is non-magnetic 1
The components are charged into a developing tank (Phase 550 developing tank manufactured by Kyushu Matsushita Co., Ltd .: rubber roller, urethane blade), and after a certain number of rotations of the roller, the toner on the roller is sucked, and the unit is calculated from the charge amount and the weight of the sucked toner. The charge amount per volume was determined. The initial charge amount and the charge amount after rotating for 10 minutes were measured to evaluate the charge stability. 1
When the charge amount after 0 minute was 60% or more of the initial value,
% Or more was evaluated as Δ, and less than that was evaluated as ×.

Fixing test: A recording paper carrying an unfixed toner image is prepared, and the surface temperature of the heating roller is raised from 100 ° C. to 2 °.
The temperature was changed to 00 ° C., the sheet was conveyed to the fixing nip portion, and the fixing state when discharged was observed. A temperature region where the toner on the recording paper after fixing is sufficiently adhered to the recording paper without causing toner offset on the heating roller at the time of fixing is defined as a fixing temperature region. When the lower limit temperature of the fixing temperature at which this offset does not occur is TL and the upper limit temperature is TU, TU-TL is defined as the fixing temperature width. The heating roller of the fixing machine has a release layer of P
FA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) with a nip width of 4
It was evaluated in mm.

Example 1 <Formation of Resin Primary Particles> The following amounts of emulsifier and demineralized water were charged into a glass reactor equipped with a stirrer, a heating / cooling device, a concentrating device, and a device for charging raw materials and auxiliaries. The temperature was raised to 90 ° C. under a nitrogen stream.

[0027]

[Table 1] 0.5 parts of sodium dodecylbenzenesulfonate 372 parts of deionized water

Thereafter, the following monomers, an aqueous emulsifier solution and an initiator were added, and emulsion polymerization was carried out for 6.5 hours.

[0029]

[Table 2] 79 parts of styrene 21 parts of butyl acrylate 3 parts of acrylic acid 0.5 parts of trichlorobromomethane 26 parts of aqueous emulsifier 26 parts of 8% aqueous hydrogen peroxide 11 parts of 8% ascorbic acid aqueous solution 11 parts

After the completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer dispersion (hereinafter abbreviated as polymer dispersion A). The average particle diameter of the obtained polymer dispersion was 185 nm, the weight average molecular weight was 64,000, and the Tg was 65 ° C. <Aggregation step>

[0031]

[Table 3] 100 parts of polymer dispersion A (as solid content) 6.7 parts of aqueous dispersion of red dye cumin 2B (as solid content) 5 parts of aqueous polypropylene dispersion (as solid content)

The above mixture was heated to 60 ° C. at a rate of 1 ° C./minute while stirring and dispersing, and kept there for 2 hours. Then negative charge control agent phenolamide compound (20% dispersion)
0.1 part (as solid content) was added dropwise. Thereafter, the temperature was raised to 70 ° C., and the temperature was further maintained for 2 hours to complete the aggregation reaction. <Heat granulation step> After the completion of the agglutination reaction, the temperature was raised to 95 ° C and held for 5 hours in order to further increase the bonding strength of the associated particles.
Thereafter, the obtained slurry of associated particles was cooled, filtered through a Kiriyama funnel, washed with water, and freeze-dried to obtain a toner.

<Evaluation of Toner> The volume average particle diameter of the obtained toner measured by a Coulter counter was 7.2 μm. When the chargeability of the toner thus obtained was evaluated, the initial charge amount was −17.8 μC / g, and the charge stability was ○. The fixing temperature is TL162 ° C., T
TU-TL was 38 ° C or more at U200 ° C or more.

Comparative Example 1 A toner was obtained in the same manner as in Example 1 except that 0.65 part (as solid content) of a negative charge control agent phenolamide compound (20% dispersion) was initially mixed in the aggregation step. Was. The volume average particle size of the obtained toner measured by a Coulter counter was 6.8 μm. When the chargeability of the toner thus obtained was evaluated, the initial charge amount was +
It was 1.8 μC / g and was not negatively charged.

Comparative Example 2 Negative Charge Control Agent Phenolamide Compound (20% dispersion)
After completion of the aggregation step, 0.65 part (as solid content)
A toner was obtained in the same manner as in Example 1 except that the toner was added when the temperature was raised. After completion of the reaction, the obtained slurry of the associated particles was cooled and filtered through a Kiriyama funnel, and a yellowish-white filtrate was found in the filtrate. When the chargeability of the toner thus obtained was evaluated, the initial charge amount was +1.4.
μC / g, and was not negatively charged.

Comparative Example 3 A toner was obtained in the same manner as in Example 1 except that the negative charge control agent phenolamide compound was not added. When the chargeability of the toner thus obtained was evaluated, the initial charge amount was +0.4 μC / g, and the toner was not negatively charged.
As shown in these Comparative Examples 1 to 3, the toner of Comparative Example 1 was added to the toner of Example 1 from the beginning, Comparative Example 2 was added after the aggregation step, and Comparative Example 3 was not added. Were initially positively charged. On the other hand, as in Example 1, when the negative charge control agent was added after one hour from the aggregation step, the charge was negative and the stability was good.

Example 2 Toner particles were obtained in the same manner as in Example 1 except that toner particles were formed using the following mixture.

[0038]

Table 4 100 parts of polymer dispersion A (as solids) 6.7 parts (as solids) of aqueous dispersion of blue dye phthalocyanine blue

When the chargeability of the toner thus obtained was evaluated, the initial charge amount was −26.2 μC / g.
The charge stability was ○. Reference Example Behensan behenyl was emulsified by applying high-pressure shear in the presence of sodium dodecylbenzenesulfonate and nonylphenyl ether to obtain an ester wax emulsion (referred to as wax emulsion A). The solid content of the obtained emulsion was 30.0%, and the average particle size measured by UPA was 840 nm.

Example 3 <Formation of Resin Particles> The following amounts of wax emulsion A and demineralized water were charged into a glass reactor equipped with a stirrer, a heating / cooling device, a concentrating device, and a device for charging raw materials and auxiliaries. A polymer dispersion B was obtained in the same manner as in Example 1 except that the temperature was raised to 90 ° C. under a nitrogen stream.

[0041]

[Table 5] 35 parts of wax emulsion A 0.45 parts of sodium dodecylbenzenesulfonate 400 parts of deionized water

The weight average molecular weight of the obtained polymer dispersion B was 93,000. <Aggregation step>

[0043]

TABLE 6 Polymer dispersion B 110 parts (as solid content) Blue pigment phthalocyanine blue aqueous dispersion 6.7 parts (as solid content)

While dispersing and stirring the above mixture with a disperser, an aqueous NaCl solution was added thereto at 20 ° C. over 110 minutes (20 parts as a solid content). Thereafter, stirring was continued for 30 minutes, and then the negative charge control agent phenolamide compound (2
2 parts (as a solid content) were added dropwise. Then, after stirring for 15 minutes, the temperature was raised to 65 ° C. with further stirring and maintained for 2 hours to complete the aggregation step. <Heat granulation step> After the aggregation step, the temperature was raised to 95 ° C and held for 5 hours in order to further increase the bonding strength of the associated particles.
Thereafter, the obtained slurry of associated particles was cooled, filtered through a Kiriyama funnel, washed with water, and freeze-dried to obtain a toner.

<Evaluation of Toner Particles> The volume average particle diameter of the obtained toner measured by a Coulter counter was 7.0 μm. When the charge amount of the toner thus obtained was evaluated, the initial charge amount was −26.3 μC / g, and the charge stability was ○. Also, when the fixability was evaluated,
TL138, TU200 ° C or higher, TU-TL was 62 ° C or higher.

Example 4 <Formation of Resin Particles> A polymer dispersion A was obtained in the same manner as in Example 1. <Agglomeration step and heating granulation step>

[0047]

TABLE 7 100 parts of polymer dispersion A (as solids) 10 parts of wax emulsion A (as solids) 6.7 parts of aqueous dispersion of blue dye phthalocyanine blue (as solids)

The above mixture is dispersed and stirred by a disperser.
Al at 20 ° C while_Two(SO_Four) _ThreeFor 1 hour
(0.6 parts as solids). Then 15
For a minute, and then the negative charge control agent phenolamide
2 parts (as solid content) of the compound (20% dispersion) are added dropwise.
Was. Then, after stirring for 15 minutes, the temperature was raised to 65 ° C with further stirring.
Raise the temperature and hold for 0.5 hour.
To raise the temperature, the temperature was raised to 95 ° C. and maintained for 5 hours. afterwards
The resulting slurry of associated particles is cooled and filtered through a Kiriyama funnel.
The mixture was washed with water, and freeze-dried to obtain a toner.

<Evaluation of Toner> The volume average particle diameter of the obtained toner measured by a Coulter counter was 5.3 μm. When the chargeability of the toner thus obtained was evaluated, the initial charge amount was −47.5 μC / g, and the charge stability was Δ. When the fixing property was evaluated, TL1
60 ° C, TU 200 ° C or higher, TU-TL was 40 ° C or higher.

Comparative Example 4 Negative Charge Control Agent Phenolamide Compound (20% dispersion)
Example except that 5 parts (as solid content) were added from the beginning
In the same manner as in 4, a toner was obtained. The volume average particle diameter of the obtained toner measured by a Coulter counter was 6.0 μm. When the chargeability of the toner thus obtained was evaluated, the initial charge amount was +17.6 μC / g, and the toner was not negatively charged.

Comparative Example 5 Negative Charge Control Agent Phenolamide Compound (20% Dispersion)
A toner was obtained in the same manner as in Example 4 except that no was added. The volume average particle diameter of the obtained toner measured by a Coulter counter was 7.1 μm. When the chargeability of the toner thus obtained was evaluated, the initial charge amount was +
0.5 μC / g, and was not negatively charged. As shown in Comparative Examples 4 and 5, in contrast to Example 4, in Comparative Example 4, the negative charge control agent was added from the beginning, and in Comparative Example 5, the initial charge of the toner was positive if not added. Was. On the other hand, when the negative charge control agent was added after the electrolyte was added as in Example 4, the charge was negative and the stability was good.

Example 5 A toner was prepared in the same manner as in Example 3 except that the negative charge control agent phenolamide compound (20% dispersion) was changed to 0.65 parts (as solid content) when toner particles were formed. I got The volume average particle size of the obtained toner measured by a Coulter counter was 7.6 μm. When the chargeability of the toner thus obtained was evaluated, the initial charge amount was
The charge stability was ／19.4 μC / g.
Further, when the fixing property was evaluated, TL150 ° C., TU2
The TU-TL was 50 ° C or higher at 00 ° C or higher.

Example 6 <Formation of Resin Particles> A polymer dispersion A was obtained in the same manner as in Example 1. <Agglomeration step and heating granulation step>

[0054]

Table 8 100 parts of polymer dispersion A (as solid content) 6.7 parts (as solid content) of aqueous dispersion of blue dye phthalocyanine blue

The above mixture is dispersed and stirred by a disperser.
Al at 20 ° C while_Two(SO_Four) _ThreeFor 1 hour
(0.6 parts as solids). Then 15
For a minute, and then the negative charge control agent phenolamide
2 parts (as solid content) of the compound (20% dispersion) are added dropwise.
Was. Then, after stirring for 15 minutes, the temperature was raised to 65 ° C with further stirring.
Raise the temperature and hold for 0.5 hour.
To raise the temperature, the temperature was raised to 95 ° C. and maintained for 5 hours. afterwards
The resulting slurry of associated particles is cooled and filtered through a Kiriyama funnel.
The mixture was washed with water, and freeze-dried to obtain a toner.

<Evaluation of Toner Particles> The volume average particle diameter of the obtained toner measured by a Coulter counter was 5.2 μm. When the chargeability of the toner thus obtained was evaluated, the initial charge amount was −26.6 μC / g, and the charge stability was ○. When the fixing property was evaluated, TL1
60 ° C, TU 200 ° C or higher, TU-TL was 40 ° C or higher.

[0057]

According to the method of the present invention, one hour after the start of the aggregation step, or one-tenth of the time from the start to the end of the aggregation step has elapsed, and before the end of the aggregation step. By adding a charge control agent, it is possible to obtain a toner that is particularly excellent in charge stability and satisfies high resolution, low-temperature fixability, and offset resistance. That is, Embodiment 1
When the charge control agent was added one hour or more after the start of the aggregation step, good chargeability and charge stability were exhibited. In Comparative Example 1, the negative charge control agent was added from the beginning. In Comparative Example 2, when the toner was added after completion of the aggregation step, and in Comparative Example 3, the toner was not added, the initial charge of the toner was positive. Furthermore, in the present invention, when the electrolyte is added in the aggregation step, by adding the charge control agent after the addition of the electrolyte and before the end of the aggregation step, particularly, the charge stability is excellent, high resolution, low-temperature fixing property, and anti-offset property. A toner satisfying the properties can be obtained. That is, in Example 4, when the charge control agent was added after the addition of the electrolyte, good chargeability and charge stability were exhibited. In Comparative Example 4, the negative charge control agent was added from the beginning. When no toner was added, the initial charge of the toner was positively charged.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Xu Yuki 1000 Kamoshidacho, Aoba-ku, Aoba-ku, Yokohama-shi, Kanagawa Prefecture Inside the Mitsubishi Chemical Research Laboratory (72) Inventor ▲ Huo ▼ Masami Mori Kamoshida, Aoba-ku, Yokohama-shi, Kanagawa 1000-cho, Mitsubishi Chemical Corporation Yokohama Research Laboratory F-term (reference) 2H005 AB03 AB06 CA14 DA01 EA07

Claims (6)

[Claims] (1) an aggregation step of forming aggregated particles in a dispersion obtained by dispersing at least resin primary particles and colorant particles; and (2) heating and fusing the aggregated particles to form a toner. In the method for producing a toner for developing an electrostatic image, which includes both a heat granulation step and a heat granulation step for forming particles, after one hour from the start of the aggregation step, until the end of the aggregation step, or from the start of the aggregation step 1 / of the time to the end
10. A method for producing a toner for developing an electrostatic image, comprising adding a charge control agent after the elapse of 10 and before the end of the aggregation step. (1) In a dispersion obtained by dispersing at least resin primary particles and colorant particles, 0.01 to 100 parts of an electrolyte is further added and mixed with 100 parts of a polymer solid content. Agglomeration step of forming aggregated particles by heating after forming secondary particles as a dispersion liquid; (2) heating granulation step of heating and fusing the aggregated particles to form toner particles;
A method for producing a toner for developing an electrostatic charge image, comprising the steps of: adding an electrolyte and adding a charge control agent by the end of the aggregation step. 3. The method for producing a toner for developing an electrostatic image according to claim 1, wherein the charge control agent added during the aggregation step is a dispersion liquid dispersed in water. 4. The toner for developing an electrostatic image according to claim 1, wherein the amount of the charge control agent added during the aggregation step is from 0.1 to 5 parts by weight based on the resin particles. Manufacturing method. 5. The method according to claim 1, wherein the primary resin particles are particles obtained by a seed polymerization method using wax fine particles as seeds. 6. A toner for developing an electrostatic image, produced by the method according to claim 1. Description: