JP3099776B2 - Method for producing electrostatic image developing toner, toner produced by the method, and image forming method using the toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic image used for developing an electrostatic latent image formed by an electrophotographic method or an electrostatic recording method with a developer, a method for producing the same, and The present invention relates to an electrostatic image developer using the toner and an image forming method.

[0002]

2. Description of the Related Art Methods for visualizing image information via an electrostatic image, such as electrophotography, are currently used in various fields. In electrophotography, an electrostatic image is formed on a photoconductor by a charging and exposing process, an electrostatic latent image is developed with a developer containing a toner, and the image is visualized through a transfer and fixing process. The developer used here includes a two-component developer consisting of a toner and a carrier, and a one-component developer using a magnetic toner or a non-magnetic toner alone. The method for producing the toner is usually a thermoplastic resin. A kneading and pulverizing method is used in which the mixture is melt-kneaded with a pigment, a charge controlling agent, a release agent, and the like, cooled, finely pulverized, and then classified. If necessary, inorganic or organic fine particles for improving the fluidity and cleaning properties may be added to the surface of the toner particles. In the ordinary kneading and pulverizing method, the toner shape and the surface structure of the toner are indefinite, and although they vary slightly depending on the pulverizability of the materials used and the conditions of the pulverizing process, it is difficult to intentionally control the toner shape and the surface structure. is there. Particularly, in the case of a material having high pulverizability, the generation of fine powder and the change in the shape of toner often occur due to mechanical force in a developing machine. Due to these effects, in the two-component developer, the deterioration of the charge of the developer is accelerated due to the fixation of the fine powder to the carrier surface, and in the one-component developer, the toner is scattered due to the expansion of the particle size distribution,
Deterioration of image quality is likely to occur due to a decrease in developability due to a change in toner shape.

In addition, when a toner such as a wax is internally added to form a toner, the exposure of the mold releasing agent to the surface is often affected by a combination with a thermoplastic resin. In particular, in the case of a combination of a resin which is imparted with elasticity by a high molecular weight component and is hardly pulverized and a brittle wax such as polyethylene, polyethylene is often exposed on the toner surface. Although these are advantageous for the releasability at the time of fixing and for cleaning the untransferred toner from the photoreceptor, contamination of the developing roll, the photoreceptor, and the carrier due to the ease of transfer of the surface polyethylene due to mechanical force. More likely to occur, leading to lower reliability. Also, due to the irregular shape of the toner, even if a flow aid is added, the flow does not become sufficient,
By the action of mechanical force during use, the fine particles on the toner surface move to the concave portion, whereby the fluidity decreases over time, or the fluidity aid is buried inside the toner,
Developability, transferability, and cleaning properties deteriorate. Further, when the toner collected by the cleaning is returned to the developing device and used again, the image quality is further likely to deteriorate. If the flow aid is further increased in order to prevent these, black spots on the photoreceptor and scattering of the aid particles occur.

In recent years, as a method for intentionally controlling the shape and surface structure of a toner, there have been proposed methods for producing a toner by an emulsion polymerization aggregation method as disclosed in JP-A-63-282755 and JP-A-6-250439. . These are generally prepared by preparing a resin dispersion by emulsion polymerization or the like, preparing a colorant dispersion in which a colorant is dispersed in a solvent, mixing these resin dispersion and the colorant dispersion, and corresponding to the toner particle size. This is a manufacturing method in which the aggregated particles are formed and then heated to fuse the aggregated particles into a toner. However, in these methods, the surface composition is intentionally controlled because the toner surface and the inside have the same composition. It is difficult to do.

As described above, in order to maintain stable performance of the toner even under various mechanical stresses in the electrophotographic process, it is necessary to suppress the exposure of the release agent to the surface or to increase the toner surface hardness. It is necessary to further improve the smoothness of the toner surface. The release agent does not necessarily need to be exposed on the surface in order to exhibit its performance at the time of fixing, but is preferably present near the toner surface.

By the way, in the above-mentioned method for producing a toner by the emulsion polymerization aggregation method, use of a surfactant is indispensable for maintaining the dispersibility of the resin particles and forming stable aggregated particles. A surfactant is also required when preparing a dispersion such as a release agent such as a polyester resin or wax which is not based on emulsion polymerization, and a colorant such as a pigment. Surfactants used in the preparation of these toners are removed to some extent in the toner washing step, but eventually remain in the toner, causing the adsorption and desorption of water, and the charge in summer and winter. The fluctuation of the amount is increased, causing a problem of the so-called environment dependency of the developer, which affects the stability of image quality. Further, since the residual surfactant tends to lower the electric resistance of the toner, it may adversely affect development / transfer characteristics, developer life, image quality maintenance, and reliability. Further, at the time of fixing, a layer having a weak adhesive force is formed at the interface between the molten toner and a transfer substrate such as paper, so that the fixing property is weakened. For this reason, attempts have been made to reduce the amount of surfactant used for dispersing each material. There is a problem that the stability of the particle diameter at one time is lowered, and it becomes difficult to produce a toner having a targeted particle diameter distribution.

There are also problems that the washing process for removing the surfactant on or in the toner surface becomes more complicated, and that the cost of water treatment for detoxifying the wastewater becomes high. At that time, to consume a large amount of water,
In recent years, it has been difficult to realize low environmental impact products that have attracted much attention.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the conventional toner and to provide a toner for developing an electrostatic image having the following characteristics and a method for producing the same. The objects of the present invention are: Reduce the amount of surfactant remaining in the toner, based on the remaining surfactant in the toner, the charging fluctuation due to the environment, that is, environment dependence, development and transfer characteristics, developer life,
Provided is a method for producing a toner for developing an electrostatic image, which has less adverse effects on image quality maintenance and fixing properties. 2. Provided is a toner for developing an electrostatic image, which has excellent charging, developing, transferring, fixing and cleaning performances. 3. Provided is a toner for developing an electrostatic charge image having excellent stability of the above performance and high image quality and high reliability. 4. Provided is a two-component developer which does not easily cause carrier contamination and has a long life. 5. Provided is a highly reliable one-component developer which is less likely to cause contamination of a developing roll, a charging roll, and a charging blade. 6. A developer with low toner consumption is provided by high transfer efficiency. 7. High reliability is provided in a system for reusing toner collected from a cleaner-a toner recycling system. 8. High image quality is provided in a system without a cleaning mechanism-a cleanerless system. 9. Provided is a developer that simplifies a toner washing process, facilitates wastewater treatment, and realizes a low environmental load.

[0009]

The above objects are achieved by the following. That is, the production of the toner for developing an electrostatic charge image having the above-mentioned features 1 to 9 is a step of aggregating particles in a particle dispersion obtained by dispersing particles including at least resin particles, and heating the aggregated particles. At least comprising the step of fusing, in the method for producing an electrostatic image developer toner, wherein the particle dispersion contains a decomposable surfactant,
The method is characterized in that the surfactant is decomposed after the heat fusion. Further, the method for producing a toner for developing an electrostatic image of the present invention is characterized in that, in the above-mentioned production method, after the step of aggregating the particles, and before the step of fusing, a step of additionally mixing a particle dispersion. It can be included at least once. The particle dispersion obtained by dispersing the particles containing at least the resin particles, and the particle dispersion to be additionally mixed may contain a colorant and a release agent, but also a dispersion containing these colorants and a release agent, Degradable surfactants may be included. In the present invention, in a method for producing a toner for developing an electrostatic image, by using a decomposable surfactant, the toner for developing an electrostatic image which achieves high image quality is provided, and the production process thereof is also environmentally friendly. It is possible to reduce the load at least once after the step of agglomerating the particles and before the step of fusing, at least once by additionally mixing the particle dispersion. As a result, it has become possible to manufacture a toner for developing an electrostatic charge image having excellent performances such as charging, development, transfer, fixing, and cleaning performances.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A process for aggregating particles in a particle dispersion obtained by dispersing particles including resin particles, as in the method for producing a toner for developing an electrostatic image of the present invention; A method for producing an electrostatic image developer toner including at least a step of heating and fusing, for example, a resin dispersion prepared by emulsion polymerization using an ionic surfactant and an ionic interface having an opposite polarity The pigment dispersed in the activator is mixed to form hetero-aggregation to form aggregated particles having a diameter substantially equal to the toner diameter, and thereafter, the aggregates are united by heating to a temperature equal to or higher than the glass transition point of the resin. There is known a toner manufacturing method of washing, drying and drying. In this manufacturing method, it has been proposed to control the shape of the toner from an irregular shape to a spherical shape by selecting a heating temperature condition. In the production method as described above, a step of preparing a resin particle dispersion by emulsion polymerization, seed polymerization, etc., a step of preparing a pigment particle dispersion, a step of preparing a release agent particle dispersion, and forming aggregated particles Although it has been proposed that various surfactants are used in the stage and in the stage of stabilizing the aggregated particles, in practice, a branched or linear alkylbenzenesulfonic acid-based surfactant is used. Often. In particular, when a resin dispersion is prepared by emulsion polymerization, these alkylbenzenesulfonic acid-based anionic surfactants are almost always used. The reason is that it is inexpensive and has excellent dispersion stability of resin particles and agglomerated particles because of exhibiting a stable surface activity effect at high temperature heating during polymerization and fusion. Further, in emulsion polymerization, a nonionic surfactant may be used in combination in order to prevent aggregation at room temperature, but an alkylbenzenesulfonic acid-based anionic surfactant having high high-temperature stability is essential in most cases.

Although these high-temperature-stable alkylbenzenesulfonic acid-based anionic surfactants are useful for preparing toner particles in water, they tend to remain on the surface or inside after the preparation of toner particles and cannot be sufficiently removed even in the washing step. Furthermore, since it has a benzene ring in the hydrophobic group, it is extremely stable chemically and it is difficult to chemically decompose it without affecting the toner particles. Although it is possible to perform microbial decomposition using activated sludge or the like, the decomposition rate is extremely low and is not practical, and furthermore, wastewater treatment is not always easy.

However, as a result of examining various ionic surfactants, it was found that sulfate-based surfactants can be decomposed by selecting washing conditions. Sulfate ester surfactants are roughly classified into higher alcohol sulfate ester type and higher alkyl ether sulfate ester type, and three types of sulfated oil / sulfated fatty acid ester / sulfated fatty acid type. In the case of lauryl sulfate sodium salt, which is hydrolyzable and is typical of the higher alcohol sulfate ester type, heating under acidic conditions such as sulfuric acid or alkaline conditions such as caustic soda alkali makes it relatively easy to recover. Decomposes into higher alcohols and sulfates. As the sulfate-based surfactant used in the present invention, in addition to the above-mentioned lauryl sulfate sodium salt, cetyl sulfate sodium salt,
Examples include stearyl sulfate sodium salt, oleyl sulfate sodium salt, Macko alcohol sulfate sodium salt, Ziegler alcohol sulfate sodium salt, oxo alcohol sulfate sodium salt, lauryl ether sulfate sodium salt, and the like. Even in the case of a sulfonic acid-based anionic surfactant, α-olefin sulfonate can be similarly decomposed. In addition, the present inventors have found that even an alkylbenzenesulfonic acid-based activator, which is usually extremely chemically stable, contains an azo group between a hydrophobic group and a hydrophilic group as shown in the following chemical structural formula. It was also found that it can be easily decomposed by light irradiation.

[0013]

Embedded image Here, R is a linear or branched alkyl group having 1 to 30 carbon atoms, and X means Na, K, Li, or NH ₄ .

The azo group-containing surfactants as described above include, for example, PMSE FALL MEETING, 73,
1995, P153, Polymer vol. 45, no.
3, 1996, P155.

When the above-mentioned sulfate ester surfactant or the azo group-containing surfactant represented by the above chemical formula is used in the particle dispersion and decomposed in the post-treatment of the coalescing step, the surfactant becomes hydrophobic. Decomposes into a water-soluble part and a water-soluble part, so that it can no longer function as a surfactant, and does not affect water absorption etc. even if decomposition products remain in the toner . In addition, the water-soluble portion is easily dissolved in water, so that the cleaning treatment is facilitated, and the detoxification of the wastewater from the cleaning step is extremely easy. When preparing a particle dispersion using these decomposable surfactants, it is necessary to pay attention to the polymerization temperature conditions, particle dispersion conditions, and decomposition conditions of the activator, but the aggregation is almost the same as in the past. The particles can be formed and coalesced to form toner particles. If necessary, a conventional alkylbenzenesulfonic acid-based surfactant or a nonionic surfactant can be used in combination, but in that case, it is better to reduce the amount of use.

In the present invention, the step of aggregating particles in a particle dispersion formed by dispersing particles containing at least resin particles formed by the method as described above comprises the step of: dispersing the dispersion at least at the glass transition temperature of the resin or lower. This is carried out by stirring at a temperature of several minutes to several hours.

Prior to the step of aggregating the particles, a resin particle dispersion in which resin particles are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and a release agent particle are dispersed in advance. Since the release agent particle dispersion liquid and the like are collectively mixed and uniformly dispersed, and then the aggregation step can be performed, the resin particles, the colorant particles, the release agent particles, etc. are uniformly mixed. A certain agglomerated particle will be fused and united,
In this case, the toner composition becomes uniform from the surface to the inside.
In particular, when a release agent is contained, the release agent is still present on the surface after coalescing and coalescence, causing the occurrence of filming and the burying of an external additive for imparting fluidity inside the toner. Is more likely to occur.

In the present invention, as a result of intensive studies on the conditions of the aggregation step, the initial balance of the amount of the ionic surfactant of each polarity is shifted in advance in the aggregation step.
After forming the first stage aggregated particles below the glass transition temperature of the resin and stabilizing, add a particle dispersion treated with a surfactant with a polarity and amount to compensate for the imbalance as the second stage. After mixing and further stabilizing at a higher temperature by heating slightly below the glass transition point of the resin contained in the base aggregated particles or additional particles as needed, aggregated particles are formed by heating above the glass transition point. The particles added in the second step can be coalesced while being attached to the surface of the mother aggregated particles. In addition, since these aggregation stepwise operations can be repeatedly performed a plurality of times, the composition and physical properties can be changed stepwise from the surface to the inside of the toner particles, and the control of the toner structure becomes extremely easy.

For example, in the case of a color toner using a multi-color toner, in the first step, a matrix aggregated particle is formed of resin particles and pigment particles, and then a resin particle dispersion is added to form only the resin layer on the toner surface. By forming the pigment, the influence of the pigment particles on the charging behavior can be minimized, so that a difference in the charging characteristics depending on the type of the pigment can be suppressed. Further, if the glass transition point of the particles added in the second stage is set to be higher, the toner is coated with the resin in a capsule shape, and both the heat storage property and the fixing property can be achieved.
When a dispersion of inorganic fine particles is used in the second step, toner particles having a structure in which capsules are covered with inorganic particles after coalescence can be produced. Alternatively, the second step is to add a release agent particle dispersion such as wax, and the third step is to form a shell on the outermost surface using a resin or inorganic particle dispersion having high hardness to suppress the exposure of the wax. At the time of fixing, the wax can effectively act as a release agent. Of course, in the first step, after preparing particles of the dispersion containing the resin particles and the release agent particles in the dispersion liquid to form base aggregated particles containing the release agent, in the second step, a high hardness shell is formed on the outermost surface. After formation and exposure of the wax may be suppressed, further, in the first stage, after mixing the resin particle dispersion, the pigment particle dispersion and the release agent particle dispersion to aggregate the particles to form mother aggregated particles, The resin particle dispersion may be additionally mixed to attach additional resin particles to the surface of the mother aggregated particles.

Further, by forming an aggregated structure on the surface in a stepwise manner, it is possible to maintain the particle size distribution during fusion and coalescence by heating at a high temperature after aggregation, and to suppress the fluctuation of the average particle size from the aggregated particle size. In addition, the addition of a surfactant or a stabilizer such as a base or an acid for improving the stability of these fusions can be eliminated or the amount can be suppressed to a minimum. The particle size of the dispersed particles is desirably 1 μm or less in both the particle dispersion used in the first stage and the dispersion used in the additional mixing step. The distribution of the diameter becomes wide, the generation of free particles occurs,
It is likely to cause a decrease in performance and reliability.

The amount of the particle dispersion to be additionally mixed depends on the volume fraction of the particles contained, and it is desirable that the amount of the additional particles is within 50% of the aggregated particles in the volume finally produced. If it is more than this, the composition distribution and the particle size distribution become remarkable due to the formation of newly aggregated particles instead of aggregation to the base particles, and desired performance cannot be obtained. Further, by adding the particles stepwise or gradually and continuously, it is possible to suppress the generation of new fine aggregated particles and sharpen the particle size distribution. Further, the generation of free particles can be suppressed by increasing the temperature within the range of the glass transition temperature of the parent aggregated particles or the additional particles at each stage of addition.

In the present invention, in the step of heating and coalescing the aggregated particles, the dispersion is heated to a temperature at which the aggregated particles coalesce and coalesce (above the glass transition temperature of the resin) to fuse the aggregated particles. Let it go.

As an index of the particle size distribution, D1 of the cumulative distribution
6. Volume GSD or number G using D84 as follows:
SD can be used simply. Volume GSD = (volume D84 / volume D16) 0.5 power Number GSD = (number D84 / number D16) 0.5 power

Examples of the monomers constituting the polymer to be the thermoplastic binder resin used in the present invention include styrenes such as styrene, parachlorostyrene and α-methylstyrene, methyl acrylate and ethyl acrylate. Esters having a vinyl group such as n-propyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, acrylonitrile , Vinyl nitriles such as methacrylonitrile, vinyl methyl ether, vinyl ethers such as vinyl isobutyl ether, vinyl methyl ketone, vinyl ethyl ketone, vinyl ketones such as vinyl isopropenyl ketone, ethylene, propylene,
Polymers such as monomers such as polyolefins such as butadiene or copolymers obtained by combining two or more of these or mixtures thereof, and further epoxy resins, polyester resins, polyurethane resins, polyamide resins,
Cellulose resins, non-vinyl condensed resins such as polyether resins, or a mixture of these and the vinyl resin or a graft polymer obtained when polymerizing a vinyl monomer in the presence of these, and the like. it can. In the case of a vinyl monomer, a resin particle dispersion can be prepared by performing emulsion polymerization or seed polymerization using an ionic surfactant or the like, and in the case of other resins, it is oily and has a solubility in water. If the resin is soluble in a relatively low solvent, dissolve the resin in those solvents and disperse the fine particles in water with a disperser such as a homogenizer together with an ionic surfactant or polymer electrolyte, and then heat or reduce the pressure. By evaporating the solvent, a resin dispersion can be prepared.

Examples of the dissociable vinyl monomers include acrylic acid, methacrylic acid, maleic acid, cinnamic acid, fumaric acid, vinylsulfonic acid, ethyleneimine, vinylpyridine, vinylamine, etc. Although any of the monomers as base materials can be used, monomers as polymer acid materials are preferable from the viewpoint of easiness of polymerization reaction, and particularly, acrylic acid, methacrylic acid, maleic acid, Dissociable vinyl monomers having a carboxyl group such as cinnamic acid and fumaric acid are preferred for controlling the degree of polymerization and controlling the glass transition point.

Examples of the release agent used in the present invention include low molecular weight polyolefins such as polyethylene, polypropylene and polybutene, silicones having a softening point by heating, oleamide, erucamide, ricinoleamide, and stearin. Fatty acid amides such as acid amide, ester wax, carnauba wax,
Minerals such as vegetable waxes such as rice wax, candelilla wax, wood wax, jojoba oil, etc., animal waxes such as beeswax, montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, etc. ,
Petroleum waxes and their modifications can be used. The release agent particle dispersion is obtained by dispersing the release agent as described above using a polymer electrolyte such as a polymer acid or a polymer base or an ionic surfactant, and heating the mixture to a temperature equal to or higher than the melting point of the release agent. It can be obtained by dispersing using a high-pressure type homogenizer or a discharge type disperser capable of applying a strong shear as described below, and then cooling to solidify the release agent fine particles. In addition to the release agent,
You may add a coloring agent, a charge control agent particle, an internal additive particle, etc. As the disperser used for dispersion, a homogenizer or a disperser classified into a high-pressure type is used, and examples thereof include a Gaulin homogenizer, a microfluidizer, an optimizer, a pressure, and a homogenizer (Nippon Seiki). These emulsifiers may be combined with a plurality of emulsifiers and dispersers as pre-treatment or post-treatment. In the present invention, by using such a high-pressure type homogenizer, the volume average particle diameter is 1.
Release agent particles smaller than μm can be obtained.

Examples of the coloring agent used in the present invention include carbon black, chrome yellow, Hansa yellow, benzidine yellow, slen yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, Brilliant Carmine 3B, Brilliant Carmine 6B, Dupont Oil Red, Pyrazolone Red, Risor Red, Rhodamine B Lake, Lake Red C, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Phthalocyanine Green, Malachite Various pigments such as green oxalate, acridine, xanthene, azo, benzoquinone, azine , Anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, thioindico, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, thiazine, thiazole, xanthene, etc. One or more colorants such as various dyes can be used in combination.

The internal additives used in the present invention include ferrite, magnetite, reduced iron, cobalt,
Magnetic materials such as metals and alloys such as nickel and manganese, or compounds containing these metals, quaternary ammonium salt compounds, nigrosine compounds, dyes comprising complexes of aluminum, iron and chromium, and triphenylmethane pigments are usually used. Various charge control agents used can be used,
Materials that are hardly soluble in water are preferred from the viewpoints of controlling ionic strength that affects coagulation and stability at the time of aggregation and reducing wastewater contamination.

Examples of the inorganic fine particles to be added by a wet method include silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, etc. which are all usually used as external additives on the toner surface, such as ionic surfactants and high It can be used by dispersing it in a molecular acid or polymer base.

After drying in the same manner as a normal toner, inorganic particles such as silica, alumina, titania, and calcium carbonate, and fine resin particles such as a vinyl resin, polyester, and silicone are added to the surface in a dry state by shearing. hand,
It can also be used as a flow aid or a cleaning aid.

Examples of the surfactant used in combination with the decomposable surfactant in the present invention include anionic surfactants such as sulfonates, phosphates and soaps, amine salts and quaternary ammonium salts. It is also effective to use a nonionic surfactant such as a cationic surfactant such as a type, a polyethylene glycol-based, an alkylphenol-ethylene oxide adduct-based, or a polyhydric alcohol-based as a means for dispersion. General examples such as a rotary shearing homogenizer, a ball mill having a media, a sand mill, and a dyno mill can be used.

When a composite comprising a resin and a pigment is used as the pigment particles, the resin and the pigment are dissolved and dispersed in a solvent, and then dispersed in water with an appropriate dispersant as described above. It can be prepared and prepared by a method of removing the solvent under reduced pressure, or by mechanically shearing or electrically adsorbing and immobilizing the latex surface prepared by emulsion polymerization or seed polymerization. These methods are effective in suppressing the release of the pigment as additional particles and improving the pigment dependency of chargeability.

[0033]

【Example】

Example 1 Preparation of Resin Dispersion 1 Styrene 340 g n-butyl acrylate 60 g acrylic acid 12 g dodecanethiol 10 g 4 carbon bromide 4 g A mixture of the above and dissolved components was mixed with 6 g of the nonionic surfactant Nonipol 400 (manufactured by Sanyo Chemical). Emar O anionic surfactant (Sodium lauryl sulfate manufactured by Kao)
4.7 g of ion-exchanged water dissolved in 500 g of ion-exchanged water was dispersed and emulsified in a flask, and while slowly mixing for 10 minutes, 50 g of ion-exchanged water in which 4 g of ammonium persulfate was dissolved was added to replace nitrogen. Thereafter, the flask was heated with stirring in an oil bath until the content reached 70C, and emulsion polymerization was continued for 6 hours. Thereby, the center particle diameter is 160 nm, the glass transition point is 60 ° C., and the Mw is 210.
00 was obtained.

Preparation of Pigment Dispersion 1 Carbon black 50 g of Mogal L (Cabot) 6 g of Emar O 200 g of ion-exchanged water 200 g or more were mixed and dissolved, and dispersed with an ultrasonic disperser for 20 minutes to obtain a carbon black dispersion having a center particle diameter of 180 nm. Obtained.

Preparation of Aggregated / Agglomerated Particles Resin Dispersion 1 520 g Pigment Dispersion 1 60 g Sanisol B50 5 g In a round stainless steel flask, after mixing and dispersing using an Ultra Turrax T50, the flask was heated in an oil bath for heating. Heat to 58 ° C. with stirring. After holding at 58 ° C. for 60 minutes, when observed with an optical microscope, about 6
It was confirmed that μm aggregated particles were generated. Thereafter, 10 g of Emal O was added thereto, and then the stainless steel flask was sealed, heated to 110 ° C. while continuing to stir using a magnetic seal, and held for 3 hours. After cooling, the mixture was filtered, washed sufficiently with ion-exchanged water, and the particle size was measured using a Coulter counter to be 6.2 μm. The volume GSD, which is an index of the volume particle size distribution, was 1.22.

After washing half of the toner with ion-exchanged water, it was dried with a vacuum dryer. This toner is referred to as Sample A. The other half was stirred for 30 minutes while heating at 50 ° C. in 0.2 N sulfuric acid, washed with water, and dried with a vacuum drier. This toner is referred to as Sample B.
To a ferrite carrier coated with 1% polymethyl methacrylate (manufactured by Soken Chemical Co., Ltd.) and having an average particle diameter of 50 μm, samples A and B were weighed in a glass bottle so that the toner concentration was 5% by weight, and the summer environment (30 ° C., relative (85% humidity) and mixed on a ball mill table for 5 minutes. Sample A
Shows a charge amount of 12 μC / g and sample B shows a charge amount of 27 μC / g, but sample B showed a higher charge amount. Cabot silica TS7 for samples A and B
After adding and mixing 0.8% by weight of No. 20, the mixture was mixed with the above carrier, and a continuous running test was performed using a cleaner-less developing machine of 5,000 sheets in winter and 5,000 sheets in summer. In Sample A, the background portion was slightly stained in a summer environment, and in Sample B, a stable image was maintained for 10,000 sheets.

Example 2 Preparation of Resin Dispersion 2 280 g of styrene, 120 g of n-butyl acrylate, and 12 g of acrylic acid were mixed and dissolved, and 6 g of nonionic surfactant Nonipol 400 and 6 g of anionic surfactant Emal O were ionized. In a flask dissolved in 550 g of exchanged water, the mixture was dispersed and emulsified in a flask, and while slowly mixing for 10 minutes, 50 g of ion-exchanged water in which 2 g of ammonium persulfate was dissolved was added, followed by nitrogen replacement. Thereafter, the contents were heated to 70 ° C. in an oil bath while stirring the flask, and emulsion polymerization was continued for 5 hours. Thus, an anionic resin dispersion having a center diameter of 105 nm, a glass transition point of 52 ° C., and Mw of 600,000 was obtained.

Preparation of Release Agent Dispersion 1 Paraffin wax HNP0190 (melting point: 85C Nippon Seiro) 50 g Cationic surfactant Sanisole B50 (Kao) 7.5 g Deionized water 200 g After dispersion using Ultra Turrax T50, dispersion treatment was performed with a pressure discharge type homogenizer to obtain a wax dispersion having a center diameter of 250 nm.

Preparation of Aggregated Particles Resin Dispersion 1 120 g Resin Dispersion 2 80 g Pigment Dispersion 1 30 g Release Agent Dispersion 1 40 g Sanisol B50 1.5 g Using an Ultra Turrax T50 in a round stainless steel flask After mixing and dispersing, the flask was heated to 48 ° C. while being stirred in a heating oil bath. After holding at 48 ° C. for 30 minutes, observation with an optical microscope confirmed that aggregated particles of about 5.2 μm had been formed. Here, 60 g of the resin dispersion liquid 1 was slowly added, and the temperature of the oil bath for heating was further increased and maintained at 50 ° C. for 1 hour. Observation with an optical microscope confirmed that aggregated particles of about 5.8 μm had been formed. Thereafter, 3 g of Emal O was added thereto, heated to 95 ° C., and kept for 5 hours. After cooling, the mixture was filtered, washed sufficiently with ion-exchanged water, and the particle size was measured using a Coulter counter.
μm. Volume GSD which is an index of volume particle size distribution
Was 1.23.

After half of the toner was washed with ion-exchanged water, it was dried with a vacuum dryer. This toner is referred to as Sample C. The other half was stirred in 0.2 N sulfuric acid at 50 ° C. for 30 minutes while heating, washed with water, and dried with a vacuum drier. This toner is designated as Sample D. A ferrite carrier coated with 1% polymethyl methacrylate (manufactured by Soken Chemical Co., Ltd.) having an average particle size of 50 μm was weighed in a glass bottle so that the concentration of the toner was 5% by weight, and mixed on a ball mill table for 5 minutes. The environmental conditions at the time of mixing were set to a summer environment (30 ° C., relative humidity 85%), and after the toner and carrier were mixed, the charge amount was measured using a blow-off charge amount measuring device manufactured by Toshiba. Sample C is 14μ
C / g and Sample D were 31 μC / g, each showing a sufficient charge amount, but Sample D showed a higher charge amount. Thereafter, when these were observed with an electron microscope, the surface state of the wax-like substance was slight on the surface of the toner, and no release was observed. When a fixing test was carried out by rubbing a waste with a fastness tester using a modified Fuji Xerox V500 machine, sufficient fixability was exhibited at a heat roll temperature of 130 ° C., and the offset was 22%.
No generation was observed up to 0 ° C. Sample C and sample D were mixed with the above-mentioned carrier, and a 5,000-sheet continuous running test was performed on a V500 modified machine in a winter environment (30 ° C., 85% relative humidity) and 5,000 sheets in a summer environment (10 ° C., 15% relative humidity). Sample C showed a slightly higher image density up to 10,000 sheets, but Sample D showed more stable image quality than Sample C and consumed less toner. Also,
In cleaning sample D, toner sample E was prepared by replacing 0.2N sulfuric acid with 0.2N aqueous sodium hydroxide solution.
It was created. Apply this toner in a summer environment (30 ° C, 85% R
When the charge amount was measured in H), the charge amount was 28 μc / g, indicating a much higher charge amount than Sample C.

Example 3 Preparation of Resin Dispersion 3 Styrene 340 g n-butyl acrylate 60 g acrylic acid 16 g dodecanethiol 10 g 4 carbon bromide 4 g A mixture obtained by mixing and dissolving the above components was mixed with a nonionic surfactant Nonipol 400 (manufactured by Sanyo Chemical). 6 g of the following chemical structural formula-(Sodium dodecylbenzenesulfonate containing a diazo group)
6.5 g was dissolved in 500 g of ion-exchanged water, dispersed and emulsified in a flask in a flask, and slowly mixed for 10 minutes.
Then, 0 g was charged and the atmosphere was replaced with nitrogen. Thereafter, the contents were heated to 70 ° C. in an oil bath while stirring the flask, and emulsion polymerization was continued for 6 hours. Care was taken not to irradiate the system with unnecessary light in the above operation.
Thereby, the center diameter is 175 nm, and the glass transition point is 58.5.
C, an anionic resin dispersion having Mw of 19500 was obtained.

Preparation of Pigment Dispersion 2 Copper phthalocyanine pigment (manufactured by BASF) 100 g Anionic surfactant Emal O (sodium lauryl sulfate manufactured by Kao) 10 g Ion-exchanged water 200 g A mixture of at least 200 g of a rotor and a stator was homogenized (IKA Ultra). (Turrax) for 10 minutes and further with an ultrasonic disperser for 20 minutes to prepare a cyan pigment dispersion having a center diameter of 160 nm.

Preparation of Release Agent Dispersion 2 100 g of Mitsui Wax 100P (melting point: 115 ° C., manufactured by Mitsui Petrochemical Co.) 200 g of ion-exchanged water 4 g of anionic surfactant Emal O 4 g or more were heated to 120 ° C. under pressure, After the dispersion, the mixture was subjected to a dispersion treatment using a pressure discharge type homogenizer to obtain a wax dispersion having a center diameter of 220 nm.

Preparation of Agglomerated / Fused Particles Resin Dispersion 3 120 g Resin Dispersion 2 80 g Pigment Dispersion 2 30 g Release Agent Dispersion 2 20 g Sanisol B50 1.8 g The above were placed in a round stainless steel flask in an Ultra Turrax T50. Then, the mixture was dispersed and dispersed, and heated to 48 ° C. while stirring the flask in an oil bath for heating. 48 ° C
, And observed with an optical microscope, it was confirmed that aggregated particles having a size of about 5.5 μm had been formed. Here, 60 g of the resin dispersion 3 was gradually added, and the temperature of the oil bath for heating was further increased and maintained at 50 ° C. for 1 hour. Observation with an optical microscope confirmed that aggregated particles of about 6.0 μm had been formed. Then, after adding 5 g of the substance of the above chemical structural formula, the mixture was heated to 95 ° C. and kept for 5 hours. After cooling, the mixture was filtered, washed sufficiently with ion-exchanged water, and the particle size was measured using a Coulter counter to be 6.2 μm. The volume GSD, which is an index of the volume particle size distribution, was 1.21.

After washing 1/3 of the toner with ion-exchanged water, it was dried with a vacuum dryer. This toner is designated as Sample F. Remaining 1/3 amount in 0.2N sulfuric acid at 50 ℃
The mixture was stirred for 30 minutes while heating, and further washed with water, and then dried with a vacuum drier. This toner is referred to as Sample G. Care was taken not to irradiate the system with unnecessary light in the above operation. Further, the remaining 1/3 amount was dispersed in ion-exchanged water, irradiated with ultraviolet rays by a xenon high-pressure lamp for 10 minutes, stirred for 30 minutes while heating to 50 ° C. in 0.2 N sulfuric acid, and further washed with water. Thereafter, it was dried with a vacuum dryer. This toner is designated as Sample H.

Polymethyl methacrylate (manufactured by Soken Chemical)
Was weighed in a glass bottle so that the toner concentration was 5% by weight with respect to a ferrite carrier having an average particle size of 50 μm coated with 1% of the above, and mixed on a ball mill for 5 minutes. The environmental conditions at the time of mixing were set to a summer environment (30 ° C., relative humidity 85%), and after the toner and carrier were mixed, the charge amount was measured using a blow-off charge amount measuring device manufactured by Toshiba. Sample F is
10 μC / g, sample G was 20 μC / g, sample H was 38 μC / g, and G and H each showed a sufficient charge amount. However, F was slightly lower, and sample H was a high charge amount in a summer environment. showed that. Observation of the surface state with an electron microscope revealed that in each sample, the exposure of the waxy substance to the toner surface was slight, and no release was observed. Using a remodeled Fuji Xerox V500 machine and performing a fixing evaluation by rubbing with a waste using a robustness tester, 1
Sufficient fixability was exhibited at a heat roll temperature of 30 ° C., and no offset was observed up to 220 ° C. Samples F to H were mixed with the above carrier, and developed in a toner recycling type developing machine in a winter environment (10 ° C., relative humidity 1
5%) 5000 sheets, summer environment (28 ° C, relative humidity 85)
%) A continuous running test of 5,000 sheets was performed. Sample F showed a high image density and increased toner consumption up to 10,000 sheets. However, there was no particular problem. Samples G and H had clearer cyan colors. Showed a stable image quality. Especially sample H
Showed almost no change in image quality in winter and summer environments, and almost no change in image quality due to the number of running vehicles.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shuji Sato 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Yasuo Kadokura 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Hisao Morojiri 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Takeshi Shoko 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. 1600 Fuji Xerox Co., Ltd. (56) References JP-A-63-282752 (JP, A) JP-A-6-250439 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) ) G03G 9/08 365-9/10

Claims (18)

(57) [Claims] 1. A process for aggregating particles in a particle dispersion obtained by dispersing particles containing at least resin particles, and a process for heating and aggregating the aggregated particles to produce a toner for an electrostatic image developer. A method for producing a toner for developing an electrostatic image, wherein the particle dispersion contains a decomposable surfactant, and the surfactant is decomposed after heat fusion. 2. The method according to claim 1, further comprising, after the step of aggregating the particles and before the step of fusing, at least one step of additionally mixing the particle dispersion. A method for producing an electrostatic image developing toner. 3. A dispersion having a polarity and an amount such that a particle dispersion obtained by dispersing particles containing at least resin particles compensates the ion balance of a surfactant contained in the aggregation step. 3. The method for producing a toner for developing electrostatic images according to claim 2, wherein the toner comprises an agent. 4. The method for producing a toner for developing an electrostatic image according to claim 2, wherein the dispersion liquid to be additionally mixed contains a decomposable surfactant. 5. The method for producing a toner for developing an electrostatic image according to claim 1, wherein the average particle diameter of the resin particles is 1 μm or less. 6. The method for producing a toner for developing an electrostatic image according to claim 1, wherein the particle dispersion obtained by dispersing particles containing at least resin particles contains a colorant. 7. The method for producing a toner for developing an electrostatic image according to claim 2, wherein the particle dispersion additionally mixed contains colorant particles. 8. The method for producing a toner for developing an electrostatic image according to claim 1, wherein the particle dispersion obtained by dispersing particles containing at least resin particles contains release agent particles. 9. The method for producing a toner for developing an electrostatic image according to claim 2, wherein the particle dispersion to be additionally mixed contains release agent particles. 10. The method for producing a toner for developing an electrostatic image according to claim 1, wherein the decomposable surfactant includes an ionic surfactant. 11. The method for producing a toner for developing an electrostatic image according to claim 10, wherein the ionic surfactant includes a sulfate-based surfactant. 12. The method according to claim 1, wherein the decomposable surfactant contains an azo surfactant. 13. The method for producing a toner for developing an electrostatic image according to claim 11, wherein the sulfate ester surfactant is decomposed by hydrolysis. 14. The method for producing a toner for developing an electrostatic image according to claim 12, wherein the azo surfactant is decomposed by photolysis. 15. An electrostatic image developer comprising an electrophotographic carrier and an electrostatic image developing toner, wherein the electrostatic image developing toner is obtained by the production method according to any one of claims 1 to 14. And an electrostatic image developer. 16. The electrostatic image developer according to claim 15, wherein the electrophotographic carrier has a resin coating layer. 17. A step of forming an electrostatic latent image on an electrostatic latent image carrier, a step of forming a toner image by developing the electrostatic latent image with a developer layer on a developer carrier, and transferring the toner image 16. An image forming method comprising a step of transferring onto a body and a cleaning step of removing residual toner on a latent image carrier, wherein the developer layer contains the electrostatic image developer according to claim 15. Image forming method. 18. The image forming method according to claim 17, further comprising a step of transferring the electrostatic image developing toner collected in the cleaning step to a developer layer.